Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted

Pull io_uring fixes from Jens Axboe:

 - Fix a task_work add use-after-free with SQPOLL.

   The sqpoll thread could pop and complete the last request while
   io_req_normal_work_add() was still looking at them after the mpscq
   push.

   Use the same approach as DEFER_TASKRUN to protect from that, holding
   an RCU read lock across the add, and have exit wait for an RCU grace
   period for SQPOLL rings as well.

 - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the
   big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED
   rings

 - Mark the source filter table as COW when cloning bpf filters, so
   registering another filter on the source doesn't modify the shared
   table in place

 - Initialize the task context before running the BPF loop

 - Requeue zcrx multishot receives stopped by a local resource

 - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit)

* tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring: fix task_work add use-after-free with SQPOLL
  io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full
  io_uring/zcrx: requeue multishot receives stopped by a local resource
  io_uring: initialize task context before running the BPF loop
  io_uring: zero big_cqe for aux CQEs on CQE32 rings
  io_uring: fix free entry check for 32b CQEs on CQE32 rings
  io_uring: only post the dummy skip CQE on CQE_MIXED rings
  io_uring/bpf_filter: mark source as COW when cloning filters

46 files changed, 21269 insertions, 0 deletions

diff --git a/net/rxrpc/.kunitconfig b/net/rxrpc/.kunitconfig
new file mode 100644
index 000000000..44e4a909f
--- /dev/null
+++ b/net/rxrpc/.kunitconfig
@@ -0,0 +1,6 @@
+CONFIG_KUNIT=y
+CONFIG_NET=y
+CONFIG_INET=y
+CONFIG_AF_RXRPC=y
+CONFIG_RXKAD=y
+CONFIG_AF_RXRPC_KUNIT_TEST=y
diff --git a/net/rxrpc/Kconfig b/net/rxrpc/Kconfig
new file mode 100644
index 000000000..2cebb666d
--- /dev/null
+++ b/net/rxrpc/Kconfig
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RxRPC session sockets
+#
+
+config AF_RXRPC
+	tristate "RxRPC session sockets"
+	depends on INET
+	select CRYPTO
+	select CRYPTO_LIB_DES if RXKAD
+	select KEYS
+	select NET_UDP_TUNNEL
+	help
+	  Say Y or M here to include support for RxRPC session sockets (just
+	  the transport part, not the presentation part: (un)marshalling is
+	  left to the application).
+
+	  These are used for AFS kernel filesystem and userspace utilities.
+
+	  This module at the moment only supports client operations and is
+	  currently incomplete.
+
+	  See Documentation/networking/rxrpc.rst.
+
+if AF_RXRPC
+
+config AF_RXRPC_IPV6
+	bool "IPv6 support for RxRPC"
+	depends on IPV6
+	help
+	  Say Y here to allow AF_RXRPC to use IPV6 UDP as well as IPV4 UDP as
+	  its network transport.
+
+config AF_RXRPC_INJECT_LOSS
+	bool "Inject packet loss into RxRPC packet stream"
+	help
+	  Say Y here to inject packet loss by discarding some received and some
+	  transmitted packets.
+
+config AF_RXRPC_INJECT_RX_DELAY
+	bool "Inject delay into packet reception"
+	depends on SYSCTL
+	help
+	  Say Y here to inject a delay into packet reception, allowing an
+	  extended RTT time to be modelled.  The delay can be configured using
+	  /proc/sys/net/rxrpc/rxrpc_inject_rx_delay, setting a number of
+	  milliseconds up to 0.5s (note that the granularity is actually in
+	  jiffies).
+
+config AF_RXRPC_DEBUG
+	bool "RxRPC dynamic debugging"
+	help
+	  Say Y here to make runtime controllable debugging messages appear.
+
+	  See Documentation/networking/rxrpc.rst.
+
+
+config RXKAD
+	bool "RxRPC Kerberos security"
+	help
+	  Provide kerberos 4 and AFS kaserver security handling for AF_RXRPC
+	  through the use of the key retention service.
+
+	  See Documentation/networking/rxrpc.rst.
+
+config RXGK
+	bool "RxRPC GSSAPI security"
+	select CRYPTO_KRB5
+	select CRYPTO_MANAGER
+	select CRYPTO_KRB5ENC
+	select CRYPTO_AUTHENC
+	select CRYPTO_SKCIPHER
+	select CRYPTO_HASH_INFO
+	select CRYPTO_HMAC
+	select CRYPTO_CMAC
+	select CRYPTO_SHA1
+	select CRYPTO_SHA256
+	select CRYPTO_SHA512
+	select CRYPTO_CBC
+	select CRYPTO_CTS
+	select CRYPTO_AES
+	select CRYPTO_CAMELLIA
+	help
+	  Provide the GSSAPI-based RxGK security class for AFS.  Keys are added
+	  with add_key().
+
+	  See Documentation/networking/rxrpc.rst.
+
+config RXPERF
+	tristate "RxRPC test service"
+	help
+	  Provide an rxperf service tester.  This listens on UDP port 7009 for
+	  incoming calls from the rxperf program (an example of which can be
+	  found in OpenAFS).
+
+config AF_RXRPC_KUNIT_TEST
+	tristate "RxRPC crypto KUnit test" if !KUNIT_ALL_TESTS
+	depends on KUNIT && RXKAD
+	default KUNIT_ALL_TESTS
+	help
+	  Enable the KUnit test suite for RxRPC's crypto routines.
+
+endif
diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile
new file mode 100644
index 000000000..f994f9f30
--- /dev/null
+++ b/net/rxrpc/Makefile
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Linux kernel RxRPC
+#
+
+obj-$(CONFIG_AF_RXRPC) += rxrpc.o
+
+rxrpc-y := \
+	af_rxrpc.o \
+	call_accept.o \
+	call_event.o \
+	call_object.o \
+	call_state.o \
+	conn_client.o \
+	conn_event.o \
+	conn_object.o \
+	conn_service.o \
+	input.o \
+	input_rack.o \
+	insecure.o \
+	io_thread.o \
+	key.o \
+	local_event.o \
+	local_object.o \
+	misc.o \
+	net_ns.o \
+	oob.o \
+	output.o \
+	peer_event.o \
+	peer_object.o \
+	recvmsg.o \
+	rtt.o \
+	security.o \
+	sendmsg.o \
+	server_key.o \
+	skbuff.o \
+	txbuf.o \
+	utils.o
+
+rxrpc-$(CONFIG_PROC_FS) += proc.o
+rxrpc-$(CONFIG_RXKAD) += rxkad.o fcrypt.o
+rxrpc-$(CONFIG_SYSCTL) += sysctl.o
+rxrpc-$(CONFIG_RXGK) += \
+	rxgk.o \
+	rxgk_app.o \
+	rxgk_kdf.o
+
+obj-$(CONFIG_RXPERF) += rxperf.o
+obj-$(CONFIG_KUNIT) += tests/
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
new file mode 100644
index 000000000..9ab0f22c8
--- /dev/null
+++ b/net/rxrpc/af_rxrpc.c
@@ -0,0 +1,1146 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC implementation
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/random.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/key-type.h>
+#include <linux/uio.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#define CREATE_TRACE_POINTS
+#include "ar-internal.h"
+
+MODULE_DESCRIPTION("RxRPC network protocol");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_RXRPC);
+
+unsigned int rxrpc_debug; // = RXRPC_DEBUG_KPROTO;
+module_param_named(debug, rxrpc_debug, uint, 0644);
+MODULE_PARM_DESC(debug, "RxRPC debugging mask");
+
+static struct proto rxrpc_proto;
+static const struct proto_ops rxrpc_rpc_ops;
+
+/* current debugging ID */
+atomic_t rxrpc_debug_id;
+EXPORT_SYMBOL(rxrpc_debug_id);
+
+/* count of skbs currently in use */
+atomic_t rxrpc_n_rx_skbs;
+
+struct workqueue_struct *rxrpc_workqueue;
+
+static void rxrpc_sock_destructor(struct sock *);
+
+/*
+ * see if an RxRPC socket is currently writable
+ */
+static inline int rxrpc_writable(struct sock *sk)
+{
+	return refcount_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
+}
+
+/*
+ * wait for write bufferage to become available
+ */
+static void rxrpc_write_space(struct sock *sk)
+{
+	_enter("%p", sk);
+	rcu_read_lock();
+	if (rxrpc_writable(sk)) {
+		struct socket_wq *wq = rcu_dereference(sk->sk_wq);
+
+		if (skwq_has_sleeper(wq))
+			wake_up_interruptible(&wq->wait);
+		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
+	}
+	rcu_read_unlock();
+}
+
+/*
+ * validate an RxRPC address
+ */
+static int rxrpc_validate_address(struct rxrpc_sock *rx,
+				  struct sockaddr_rxrpc *srx,
+				  int len)
+{
+	unsigned int tail;
+
+	if (len < sizeof(struct sockaddr_rxrpc))
+		return -EINVAL;
+
+	if (srx->srx_family != AF_RXRPC)
+		return -EAFNOSUPPORT;
+
+	if (srx->transport_type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	len -= offsetof(struct sockaddr_rxrpc, transport);
+	if (srx->transport_len < sizeof(sa_family_t) ||
+	    srx->transport_len > len)
+		return -EINVAL;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		if (rx->family != AF_INET &&
+		    rx->family != AF_INET6)
+			return -EAFNOSUPPORT;
+		if (srx->transport_len < sizeof(struct sockaddr_in))
+			return -EINVAL;
+		tail = offsetof(struct sockaddr_rxrpc, transport.sin.__pad);
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		if (rx->family != AF_INET6)
+			return -EAFNOSUPPORT;
+		if (srx->transport_len < sizeof(struct sockaddr_in6))
+			return -EINVAL;
+		tail = offsetof(struct sockaddr_rxrpc, transport) +
+			sizeof(struct sockaddr_in6);
+		break;
+#endif
+
+	default:
+		return -EAFNOSUPPORT;
+	}
+
+	if (tail < len)
+		memset((void *)srx + tail, 0, len - tail);
+	_debug("INET: %pISp", &srx->transport);
+	return 0;
+}
+
+/*
+ * bind a local address to an RxRPC socket
+ */
+static int rxrpc_bind(struct socket *sock, struct sockaddr_unsized *saddr, int len)
+{
+	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)saddr;
+	struct rxrpc_local *local;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	u16 service_id;
+	int ret;
+
+	_enter("%p,%p,%d", rx, saddr, len);
+
+	ret = rxrpc_validate_address(rx, srx, len);
+	if (ret < 0)
+		goto error;
+	service_id = srx->srx_service;
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		rx->srx = *srx;
+		local = rxrpc_lookup_local(sock_net(&rx->sk), &rx->srx);
+		if (IS_ERR(local)) {
+			ret = PTR_ERR(local);
+			goto error_unlock;
+		}
+
+		if (service_id) {
+			write_lock(&local->services_lock);
+			if (local->service)
+				goto service_in_use;
+			rx->local = local;
+			local->service = rx;
+			write_unlock(&local->services_lock);
+
+			rx->sk.sk_state = RXRPC_SERVER_BOUND;
+		} else {
+			rx->local = local;
+			rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+		}
+		break;
+
+	case RXRPC_SERVER_BOUND:
+		ret = -EINVAL;
+		if (service_id == 0)
+			goto error_unlock;
+		ret = -EADDRINUSE;
+		if (service_id == rx->srx.srx_service)
+			goto error_unlock;
+		ret = -EINVAL;
+		srx->srx_service = rx->srx.srx_service;
+		if (memcmp(srx, &rx->srx, sizeof(*srx)) != 0)
+			goto error_unlock;
+		rx->second_service = service_id;
+		rx->sk.sk_state = RXRPC_SERVER_BOUND2;
+		break;
+
+	default:
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+	release_sock(&rx->sk);
+	_leave(" = 0");
+	return 0;
+
+service_in_use:
+	write_unlock(&local->services_lock);
+	rxrpc_unuse_local(local, rxrpc_local_unuse_bind);
+	rxrpc_put_local(local, rxrpc_local_put_bind);
+	ret = -EADDRINUSE;
+error_unlock:
+	release_sock(&rx->sk);
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * set the number of pending calls permitted on a listening socket
+ */
+static int rxrpc_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	unsigned int max, old;
+	int ret;
+
+	_enter("%p,%d", rx, backlog);
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		ret = -EADDRNOTAVAIL;
+		break;
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_BOUND2:
+		ASSERT(rx->local != NULL);
+		max = READ_ONCE(rxrpc_max_backlog);
+		ret = -EINVAL;
+		if (backlog == INT_MAX)
+			backlog = max;
+		else if (backlog < 0 || backlog > max)
+			break;
+		old = sk->sk_max_ack_backlog;
+		sk->sk_max_ack_backlog = backlog;
+		ret = rxrpc_service_prealloc(rx, GFP_KERNEL);
+		if (ret == 0)
+			rx->sk.sk_state = RXRPC_SERVER_LISTENING;
+		else
+			sk->sk_max_ack_backlog = old;
+		break;
+	case RXRPC_SERVER_LISTENING:
+		if (backlog == 0) {
+			rx->sk.sk_state = RXRPC_SERVER_LISTEN_DISABLED;
+			sk->sk_max_ack_backlog = 0;
+			rxrpc_discard_prealloc(rx);
+			ret = 0;
+			break;
+		}
+		fallthrough;
+	default:
+		ret = -EBUSY;
+		break;
+	}
+
+	release_sock(&rx->sk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_lookup_peer - Obtain remote transport endpoint for an address
+ * @sock: The socket through which it will be accessed
+ * @srx: The network address
+ * @gfp: Allocation flags
+ *
+ * Lookup or create a remote transport endpoint record for the specified
+ * address.
+ *
+ * Return: The peer record found with a reference or a negative error code if
+ * the address is invalid or unsupported.
+ */
+struct rxrpc_peer *rxrpc_kernel_lookup_peer(struct socket *sock,
+					    struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+	struct rxrpc_peer *peer;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	ret = rxrpc_validate_address(rx, srx, sizeof(*srx));
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	peer = rxrpc_lookup_peer(rx->local, srx, gfp);
+	return peer ?: ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL(rxrpc_kernel_lookup_peer);
+
+/**
+ * rxrpc_kernel_get_peer - Get a reference on a peer
+ * @peer: The peer to get a reference on (may be NULL).
+ *
+ * Get a reference for a remote peer record (if not NULL).
+ *
+ * Return: The @peer argument.
+ */
+struct rxrpc_peer *rxrpc_kernel_get_peer(struct rxrpc_peer *peer)
+{
+	return peer ? rxrpc_get_peer(peer, rxrpc_peer_get_application) : NULL;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer);
+
+/**
+ * rxrpc_kernel_put_peer - Allow a kernel app to drop a peer reference
+ * @peer: The peer to drop a ref on
+ *
+ * Drop a reference on a peer record.
+ */
+void rxrpc_kernel_put_peer(struct rxrpc_peer *peer)
+{
+	rxrpc_put_peer(peer, rxrpc_peer_put_application);
+}
+EXPORT_SYMBOL(rxrpc_kernel_put_peer);
+
+/**
+ * rxrpc_kernel_begin_call - Allow a kernel service to begin a call
+ * @sock: The socket on which to make the call
+ * @peer: The peer to contact
+ * @key: The security context to use (defaults to socket setting)
+ * @user_call_ID: The ID to use
+ * @tx_total_len: Total length of data to transmit during the call (or -1)
+ * @hard_timeout: The maximum lifespan of the call in sec
+ * @gfp: The allocation constraints
+ * @notify_rx: Where to send notifications instead of socket queue
+ * @service_id: The ID of the service to contact
+ * @upgrade: Request service upgrade for call
+ * @interruptibility: The call is interruptible, or can be canceled.
+ * @debug_id: The debug ID for tracing to be assigned to the call
+ *
+ * Allow a kernel service to begin a call on the nominated socket.  This just
+ * sets up all the internal tracking structures and allocates connection and
+ * call IDs as appropriate.
+ *
+ * The default socket destination address and security may be overridden by
+ * supplying @srx and @key.
+ *
+ * Return: The new call or an error code.
+ */
+struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
+					   struct rxrpc_peer *peer,
+					   struct key *key,
+					   unsigned long user_call_ID,
+					   s64 tx_total_len,
+					   u32 hard_timeout,
+					   gfp_t gfp,
+					   rxrpc_notify_rx_t notify_rx,
+					   u16 service_id,
+					   bool upgrade,
+					   enum rxrpc_interruptibility interruptibility,
+					   unsigned int debug_id)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_call_params p;
+	struct rxrpc_call *call;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+
+	_enter(",,%x,%lx", key_serial(key), user_call_ID);
+
+	if (WARN_ON_ONCE(peer->local != rx->local))
+		return ERR_PTR(-EIO);
+
+	lock_sock(&rx->sk);
+
+	if (!key)
+		key = rx->key;
+	if (key && !key->payload.data[0])
+		key = NULL; /* a no-security key */
+
+	memset(&p, 0, sizeof(p));
+	p.user_call_ID		= user_call_ID;
+	p.tx_total_len		= tx_total_len;
+	p.interruptibility	= interruptibility;
+	p.kernel		= true;
+	p.timeouts.hard		= hard_timeout;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.peer			= peer;
+	cp.key			= key;
+	cp.security_level	= rx->min_sec_level;
+	cp.exclusive		= false;
+	cp.upgrade		= upgrade;
+	cp.service_id		= service_id;
+	call = rxrpc_new_client_call(rx, &cp, &p, gfp, debug_id);
+	/* The socket has been unlocked. */
+	if (!IS_ERR(call)) {
+		call->notify_rx = notify_rx;
+		mutex_unlock(&call->user_mutex);
+	}
+
+	_leave(" = %p", call);
+	return call;
+}
+EXPORT_SYMBOL(rxrpc_kernel_begin_call);
+
+/*
+ * Dummy function used to stop the notifier talking to recvmsg().
+ */
+static void rxrpc_dummy_notify_rx(struct sock *sk, struct rxrpc_call *rxcall,
+				  unsigned long call_user_ID)
+{
+}
+
+/**
+ * rxrpc_kernel_shutdown_call - Allow a kernel service to shut down a call it was using
+ * @sock: The socket the call is on
+ * @call: The call to end
+ *
+ * Allow a kernel service to shut down a call it was using.  The call must be
+ * complete before this is called (the call should be aborted if necessary).
+ */
+void rxrpc_kernel_shutdown_call(struct socket *sock, struct rxrpc_call *call)
+{
+	_enter("%d{%d}", call->debug_id, refcount_read(&call->ref));
+
+	mutex_lock(&call->user_mutex);
+	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_release_call(rxrpc_sk(sock->sk), call);
+
+		/* Make sure we're not going to call back into a kernel service */
+		if (call->notify_rx) {
+			spin_lock_irq(&call->notify_lock);
+			call->notify_rx = rxrpc_dummy_notify_rx;
+			spin_unlock_irq(&call->notify_lock);
+		}
+	}
+	mutex_unlock(&call->user_mutex);
+}
+EXPORT_SYMBOL(rxrpc_kernel_shutdown_call);
+
+/**
+ * rxrpc_kernel_put_call - Release a reference to a call
+ * @sock: The socket the call is on
+ * @call: The call to put
+ *
+ * Drop the application's ref on an rxrpc call.
+ */
+void rxrpc_kernel_put_call(struct socket *sock, struct rxrpc_call *call)
+{
+	rxrpc_put_call(call, rxrpc_call_put_kernel);
+}
+EXPORT_SYMBOL(rxrpc_kernel_put_call);
+
+/**
+ * rxrpc_kernel_check_life - Check to see whether a call is still alive
+ * @sock: The socket the call is on
+ * @call: The call to check
+ *
+ * Allow a kernel service to find out whether a call is still alive - whether
+ * it has completed successfully and all received data has been consumed.
+ *
+ * Return: %true if the call is still ongoing and %false if it has completed.
+ */
+bool rxrpc_kernel_check_life(const struct socket *sock,
+			     const struct rxrpc_call *call)
+{
+	if (!rxrpc_call_is_complete(call))
+		return true;
+	if (call->completion != RXRPC_CALL_SUCCEEDED)
+		return false;
+	return !skb_queue_empty(&call->recvmsg_queue);
+}
+EXPORT_SYMBOL(rxrpc_kernel_check_life);
+
+/**
+ * rxrpc_kernel_set_notifications - Set table of callback operations
+ * @sock: The socket to install table upon
+ * @app_ops: Callback operation table to set
+ *
+ * Allow a kernel service to set a table of event notifications on a socket.
+ */
+void rxrpc_kernel_set_notifications(struct socket *sock,
+				    const struct rxrpc_kernel_ops *app_ops)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+
+	rx->app_ops = app_ops;
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_notifications);
+
+/*
+ * connect an RxRPC socket
+ * - this just targets it at a specific destination; no actual connection
+ *   negotiation takes place
+ */
+static int rxrpc_connect(struct socket *sock, struct sockaddr_unsized *addr,
+			 int addr_len, int flags)
+{
+	struct sockaddr_rxrpc *srx = (struct sockaddr_rxrpc *)addr;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter("%p,%p,%d,%d", rx, addr, addr_len, flags);
+
+	ret = rxrpc_validate_address(rx, srx, addr_len);
+	if (ret < 0) {
+		_leave(" = %d [bad addr]", ret);
+		return ret;
+	}
+
+	lock_sock(&rx->sk);
+
+	ret = -EISCONN;
+	if (test_bit(RXRPC_SOCK_CONNECTED, &rx->flags))
+		goto error;
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+		rx->sk.sk_state = RXRPC_CLIENT_UNBOUND;
+		break;
+	case RXRPC_CLIENT_UNBOUND:
+	case RXRPC_CLIENT_BOUND:
+		break;
+	default:
+		ret = -EBUSY;
+		goto error;
+	}
+
+	rx->connect_srx = *srx;
+	set_bit(RXRPC_SOCK_CONNECTED, &rx->flags);
+	ret = 0;
+
+error:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/*
+ * send a message through an RxRPC socket
+ * - in a client this does a number of things:
+ *   - finds/sets up a connection for the security specified (if any)
+ *   - initiates a call (ID in control data)
+ *   - ends the request phase of a call (if MSG_MORE is not set)
+ *   - sends a call data packet
+ *   - may send an abort (abort code in control data)
+ */
+static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	int ret;
+
+	_enter(",{%d},,%zu", rx->sk.sk_state, len);
+
+	if (m->msg_flags & MSG_OOB)
+		return -EOPNOTSUPP;
+
+	if (m->msg_name) {
+		ret = rxrpc_validate_address(rx, m->msg_name, m->msg_namelen);
+		if (ret < 0) {
+			_leave(" = %d [bad addr]", ret);
+			return ret;
+		}
+	}
+
+	lock_sock(&rx->sk);
+
+	switch (rx->sk.sk_state) {
+	case RXRPC_UNBOUND:
+	case RXRPC_CLIENT_UNBOUND:
+		rx->srx.srx_family = AF_RXRPC;
+		rx->srx.srx_service = 0;
+		rx->srx.transport_type = SOCK_DGRAM;
+		rx->srx.transport.family = rx->family;
+		switch (rx->family) {
+		case AF_INET:
+			rx->srx.transport_len = sizeof(struct sockaddr_in);
+			break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+		case AF_INET6:
+			rx->srx.transport_len = sizeof(struct sockaddr_in6);
+			break;
+#endif
+		default:
+			ret = -EAFNOSUPPORT;
+			goto error_unlock;
+		}
+		local = rxrpc_lookup_local(sock_net(sock->sk), &rx->srx);
+		if (IS_ERR(local)) {
+			ret = PTR_ERR(local);
+			goto error_unlock;
+		}
+
+		rx->local = local;
+		rx->sk.sk_state = RXRPC_CLIENT_BOUND;
+		fallthrough;
+
+	case RXRPC_CLIENT_BOUND:
+		if (!m->msg_name &&
+		    test_bit(RXRPC_SOCK_CONNECTED, &rx->flags)) {
+			m->msg_name = &rx->connect_srx;
+			m->msg_namelen = sizeof(rx->connect_srx);
+		}
+		fallthrough;
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_LISTENING:
+		if (m->msg_flags & MSG_OOB)
+			ret = rxrpc_sendmsg_oob(rx, m, len);
+		else
+			ret = rxrpc_do_sendmsg(rx, m, len);
+		/* The socket has been unlocked */
+		goto out;
+	default:
+		ret = -EINVAL;
+		goto error_unlock;
+	}
+
+error_unlock:
+	release_sock(&rx->sk);
+out:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+int rxrpc_sock_set_min_security_level(struct sock *sk, unsigned int val)
+{
+	if (sk->sk_state != RXRPC_UNBOUND)
+		return -EISCONN;
+	if (val > RXRPC_SECURITY_MAX)
+		return -EINVAL;
+	lock_sock(sk);
+	rxrpc_sk(sk)->min_sec_level = val;
+	release_sock(sk);
+	return 0;
+}
+EXPORT_SYMBOL(rxrpc_sock_set_min_security_level);
+
+/*
+ * set RxRPC socket options
+ */
+static int rxrpc_setsockopt(struct socket *sock, int level, int optname,
+			    sockptr_t optval, unsigned int optlen)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	unsigned int min_sec_level, val;
+	u16 service_upgrade[2];
+	int ret;
+
+	_enter(",%d,%d,,%d", level, optname, optlen);
+
+	lock_sock(&rx->sk);
+	ret = -EOPNOTSUPP;
+
+	if (level == SOL_RXRPC) {
+		switch (optname) {
+		case RXRPC_EXCLUSIVE_CONNECTION:
+			ret = -EINVAL;
+			if (optlen != 0)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			rx->exclusive = true;
+			goto success;
+
+		case RXRPC_SECURITY_KEY:
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = rxrpc_request_key(rx, optval, optlen);
+			goto error;
+
+		case RXRPC_SECURITY_KEYRING:
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = rxrpc_server_keyring(rx, optval, optlen);
+			goto error;
+
+		case RXRPC_MIN_SECURITY_LEVEL:
+			ret = -EINVAL;
+			if (optlen != sizeof(unsigned int))
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = copy_safe_from_sockptr(&min_sec_level,
+						     sizeof(min_sec_level),
+						     optval, optlen);
+			if (ret)
+				goto error;
+			ret = -EINVAL;
+			if (min_sec_level > RXRPC_SECURITY_MAX)
+				goto error;
+			rx->min_sec_level = min_sec_level;
+			goto success;
+
+		case RXRPC_UPGRADEABLE_SERVICE:
+			ret = -EINVAL;
+			if (optlen != sizeof(service_upgrade) ||
+			    rx->service_upgrade.from != 0)
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_SERVER_BOUND2)
+				goto error;
+			ret = -EFAULT;
+			if (copy_from_sockptr(service_upgrade, optval,
+					   sizeof(service_upgrade)) != 0)
+				goto error;
+			ret = -EINVAL;
+			if ((service_upgrade[0] != rx->srx.srx_service ||
+			     service_upgrade[1] != rx->second_service) &&
+			    (service_upgrade[0] != rx->second_service ||
+			     service_upgrade[1] != rx->srx.srx_service))
+				goto error;
+			rx->service_upgrade.from = service_upgrade[0];
+			rx->service_upgrade.to = service_upgrade[1];
+			goto success;
+
+		case RXRPC_MANAGE_RESPONSE:
+			ret = -EINVAL;
+			if (optlen != sizeof(unsigned int))
+				goto error;
+			ret = -EISCONN;
+			if (rx->sk.sk_state != RXRPC_UNBOUND)
+				goto error;
+			ret = copy_safe_from_sockptr(&val, sizeof(val),
+						     optval, optlen);
+			if (ret)
+				goto error;
+			ret = -EINVAL;
+			if (val > 1)
+				goto error;
+			if (val)
+				set_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags);
+			else
+				clear_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags);
+			goto success;
+
+		default:
+			break;
+		}
+	}
+
+success:
+	ret = 0;
+error:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/*
+ * Get socket options.
+ */
+static int rxrpc_getsockopt(struct socket *sock, int level, int optname,
+			    sockopt_t *opt)
+{
+	int optlen, val;
+
+	if (level != SOL_RXRPC)
+		return -EOPNOTSUPP;
+
+	optlen = opt->optlen;
+
+	switch (optname) {
+	case RXRPC_SUPPORTED_CMSG:
+		if (optlen < sizeof(int))
+			return -ETOOSMALL;
+		val = RXRPC__SUPPORTED - 1;
+		if (copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		    sizeof(val))
+			return -EFAULT;
+		opt->optlen = sizeof(val);
+		return 0;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/*
+ * permit an RxRPC socket to be polled
+ */
+static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
+			       poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	__poll_t mask;
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	/* the socket is readable if there are any messages waiting on the Rx
+	 * queue */
+	if (!list_empty(&rx->recvmsg_q))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	/* the socket is writable if there is space to add new data to the
+	 * socket; there is no guarantee that any particular call in progress
+	 * on the socket may have space in the Tx ACK window */
+	if (rxrpc_writable(sk))
+		mask |= EPOLLOUT | EPOLLWRNORM;
+
+	return mask;
+}
+
+/*
+ * create an RxRPC socket
+ */
+static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
+			int kern)
+{
+	struct rxrpc_net *rxnet;
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+
+	_enter("%p,%d", sock, protocol);
+
+	/* we support transport protocol UDP/UDP6 only */
+	if (protocol != PF_INET &&
+	    IS_ENABLED(CONFIG_AF_RXRPC_IPV6) && protocol != PF_INET6)
+		return -EPROTONOSUPPORT;
+
+	if (sock->type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	sock->ops = &rxrpc_rpc_ops;
+	sock->state = SS_UNCONNECTED;
+
+	sk = sk_alloc(net, PF_RXRPC, GFP_KERNEL, &rxrpc_proto, kern);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock, sk);
+	sock_set_flag(sk, SOCK_RCU_FREE);
+	sk->sk_state		= RXRPC_UNBOUND;
+	sk->sk_write_space	= rxrpc_write_space;
+	sk->sk_max_ack_backlog	= 0;
+	sk->sk_destruct		= rxrpc_sock_destructor;
+
+	rx = rxrpc_sk(sk);
+	rx->family = protocol;
+	rx->calls = RB_ROOT;
+
+	spin_lock_init(&rx->incoming_lock);
+	skb_queue_head_init(&rx->recvmsg_oobq);
+	rx->pending_oobq = RB_ROOT;
+	INIT_LIST_HEAD(&rx->sock_calls);
+	INIT_LIST_HEAD(&rx->to_be_accepted);
+	INIT_LIST_HEAD(&rx->recvmsg_q);
+	spin_lock_init(&rx->recvmsg_lock);
+	rwlock_init(&rx->call_lock);
+	memset(&rx->srx, 0, sizeof(rx->srx));
+
+	rxnet = rxrpc_net(sock_net(&rx->sk));
+	timer_reduce(&rxnet->peer_keepalive_timer, jiffies + 1);
+
+	_leave(" = 0 [%p]", rx);
+	return 0;
+}
+
+/*
+ * Kill all the calls on a socket and shut it down.
+ */
+static int rxrpc_shutdown(struct socket *sock, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	int ret = 0;
+
+	_enter("%p,%d", sk, flags);
+
+	if (flags != SHUT_RDWR)
+		return -EOPNOTSUPP;
+	if (sk->sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	lock_sock(sk);
+
+	if (sk->sk_state < RXRPC_CLOSE) {
+		spin_lock_irq(&rx->recvmsg_lock);
+		sk->sk_state = RXRPC_CLOSE;
+		sk->sk_shutdown = SHUTDOWN_MASK;
+		spin_unlock_irq(&rx->recvmsg_lock);
+	} else {
+		ret = -ESHUTDOWN;
+	}
+
+	rxrpc_discard_prealloc(rx);
+
+	release_sock(sk);
+	return ret;
+}
+
+/*
+ * Purge the out-of-band queue.
+ */
+static void rxrpc_purge_oob_queue(struct sock *sk)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&rx->recvmsg_oobq)))
+		rxrpc_kernel_free_oob(skb);
+	while (!RB_EMPTY_ROOT(&rx->pending_oobq)) {
+		skb = rb_entry(rx->pending_oobq.rb_node, struct sk_buff, rbnode);
+		rb_erase(&skb->rbnode, &rx->pending_oobq);
+		rxrpc_kernel_free_oob(skb);
+	}
+}
+
+/*
+ * RxRPC socket destructor
+ */
+static void rxrpc_sock_destructor(struct sock *sk)
+{
+	_enter("%p", sk);
+
+	rxrpc_purge_oob_queue(sk);
+	rxrpc_purge_queue(&sk->sk_receive_queue);
+
+	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
+	WARN_ON(!sk_unhashed(sk));
+	WARN_ON(sk->sk_socket);
+
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		printk("Attempt to release alive rxrpc socket: %p\n", sk);
+		return;
+	}
+}
+
+/*
+ * release an RxRPC socket
+ */
+static int rxrpc_release_sock(struct sock *sk)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+
+	_enter("%p{%d,%d}", sk, sk->sk_state, refcount_read(&sk->sk_refcnt));
+
+	/* declare the socket closed for business */
+	sock_orphan(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	/* We want to kill off all connections from a service socket
+	 * as fast as possible because we can't share these; client
+	 * sockets, on the other hand, can share an endpoint.
+	 */
+	switch (sk->sk_state) {
+	case RXRPC_SERVER_BOUND:
+	case RXRPC_SERVER_BOUND2:
+	case RXRPC_SERVER_LISTENING:
+	case RXRPC_SERVER_LISTEN_DISABLED:
+		rx->local->service_closed = true;
+		break;
+	}
+
+	spin_lock_irq(&rx->recvmsg_lock);
+	sk->sk_state = RXRPC_CLOSE;
+	spin_unlock_irq(&rx->recvmsg_lock);
+
+	if (rx->local && rx->local->service == rx) {
+		write_lock(&rx->local->services_lock);
+		rx->local->service = NULL;
+		write_unlock(&rx->local->services_lock);
+	}
+
+	/* try to flush out this socket */
+	rxrpc_discard_prealloc(rx);
+	rxrpc_release_calls_on_socket(rx);
+	flush_workqueue(rxrpc_workqueue);
+	rxrpc_purge_oob_queue(sk);
+	rxrpc_purge_queue(&sk->sk_receive_queue);
+
+	rxrpc_unuse_local(rx->local, rxrpc_local_unuse_release_sock);
+	rxrpc_put_local(rx->local, rxrpc_local_put_release_sock);
+	rx->local = NULL;
+	key_put(rx->key);
+	rx->key = NULL;
+	key_put(rx->securities);
+	rx->securities = NULL;
+	sock_put(sk);
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * release an RxRPC BSD socket on close() or equivalent
+ */
+static int rxrpc_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	_enter("%p{%p}", sock, sk);
+
+	if (!sk)
+		return 0;
+
+	sock->sk = NULL;
+
+	return rxrpc_release_sock(sk);
+}
+
+/*
+ * RxRPC network protocol
+ */
+static const struct proto_ops rxrpc_rpc_ops = {
+	.family		= PF_RXRPC,
+	.owner		= THIS_MODULE,
+	.release	= rxrpc_release,
+	.bind		= rxrpc_bind,
+	.connect	= rxrpc_connect,
+	.socketpair	= sock_no_socketpair,
+	.accept		= sock_no_accept,
+	.getname	= sock_no_getname,
+	.poll		= rxrpc_poll,
+	.ioctl		= sock_no_ioctl,
+	.listen		= rxrpc_listen,
+	.shutdown	= rxrpc_shutdown,
+	.setsockopt	= rxrpc_setsockopt,
+	.getsockopt_iter = rxrpc_getsockopt,
+	.sendmsg	= rxrpc_sendmsg,
+	.recvmsg	= rxrpc_recvmsg,
+	.mmap		= sock_no_mmap,
+};
+
+static struct proto rxrpc_proto = {
+	.name		= "RXRPC",
+	.owner		= THIS_MODULE,
+	.obj_size	= sizeof(struct rxrpc_sock),
+	.max_header	= sizeof(struct rxrpc_wire_header),
+};
+
+static const struct net_proto_family rxrpc_family_ops = {
+	.family	= PF_RXRPC,
+	.create = rxrpc_create,
+	.owner	= THIS_MODULE,
+};
+
+/*
+ * initialise and register the RxRPC protocol
+ */
+static int __init af_rxrpc_init(void)
+{
+	int ret = -1;
+
+	BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof_field(struct sk_buff, cb));
+
+	ret = -ENOMEM;
+	rxrpc_gen_version_string();
+	rxrpc_call_jar = kmem_cache_create(
+		"rxrpc_call_jar", sizeof(struct rxrpc_call), 0,
+		SLAB_HWCACHE_ALIGN, NULL);
+	if (!rxrpc_call_jar) {
+		pr_notice("Failed to allocate call jar\n");
+		goto error_call_jar;
+	}
+
+	rxrpc_workqueue = alloc_ordered_workqueue("krxrpcd", WQ_HIGHPRI | WQ_MEM_RECLAIM);
+	if (!rxrpc_workqueue) {
+		pr_notice("Failed to allocate work queue\n");
+		goto error_work_queue;
+	}
+
+	ret = rxrpc_init_security();
+	if (ret < 0) {
+		pr_crit("Cannot initialise security\n");
+		goto error_security;
+	}
+
+	ret = register_pernet_device(&rxrpc_net_ops);
+	if (ret)
+		goto error_pernet;
+
+	ret = proto_register(&rxrpc_proto, 1);
+	if (ret < 0) {
+		pr_crit("Cannot register protocol\n");
+		goto error_proto;
+	}
+
+	ret = sock_register(&rxrpc_family_ops);
+	if (ret < 0) {
+		pr_crit("Cannot register socket family\n");
+		goto error_sock;
+	}
+
+	ret = register_key_type(&key_type_rxrpc);
+	if (ret < 0) {
+		pr_crit("Cannot register client key type\n");
+		goto error_key_type;
+	}
+
+	ret = register_key_type(&key_type_rxrpc_s);
+	if (ret < 0) {
+		pr_crit("Cannot register server key type\n");
+		goto error_key_type_s;
+	}
+
+	ret = rxrpc_sysctl_init();
+	if (ret < 0) {
+		pr_crit("Cannot register sysctls\n");
+		goto error_sysctls;
+	}
+
+	return 0;
+
+error_sysctls:
+	unregister_key_type(&key_type_rxrpc_s);
+error_key_type_s:
+	unregister_key_type(&key_type_rxrpc);
+error_key_type:
+	sock_unregister(PF_RXRPC);
+error_sock:
+	proto_unregister(&rxrpc_proto);
+error_proto:
+	unregister_pernet_device(&rxrpc_net_ops);
+error_pernet:
+	rxrpc_exit_security();
+error_security:
+	destroy_workqueue(rxrpc_workqueue);
+error_work_queue:
+	kmem_cache_destroy(rxrpc_call_jar);
+error_call_jar:
+	return ret;
+}
+
+/*
+ * unregister the RxRPC protocol
+ */
+static void __exit af_rxrpc_exit(void)
+{
+	_enter("");
+	rxrpc_sysctl_exit();
+	unregister_key_type(&key_type_rxrpc_s);
+	unregister_key_type(&key_type_rxrpc);
+	sock_unregister(PF_RXRPC);
+	proto_unregister(&rxrpc_proto);
+	unregister_pernet_device(&rxrpc_net_ops);
+	ASSERTCMP(atomic_read(&rxrpc_n_rx_skbs), ==, 0);
+
+	/* Make sure the local and peer records pinned by any dying connections
+	 * are released.
+	 */
+	rcu_barrier();
+
+	destroy_workqueue(rxrpc_workqueue);
+	rxrpc_exit_security();
+	kmem_cache_destroy(rxrpc_call_jar);
+	_leave("");
+}
+
+module_init(af_rxrpc_init);
+module_exit(af_rxrpc_exit);
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
new file mode 100644
index 000000000..865f05fe3
--- /dev/null
+++ b/net/rxrpc/ar-internal.h
@@ -0,0 +1,1728 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* AF_RXRPC internal definitions
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/atomic.h>
+#include <linux/seqlock.h>
+#include <linux/win_minmax.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "protocol.h"
+
+#define FCRYPT_ROUNDS 16
+
+struct fcrypt_key {
+	__be32 sched[FCRYPT_ROUNDS];
+};
+
+#define FCRYPT_BSIZE 8
+struct rxrpc_crypt {
+	union {
+		u8	x[FCRYPT_BSIZE];
+		__be32	n[2];
+	};
+} __attribute__((aligned(8)));
+
+void fcrypt_preparekey(struct fcrypt_key *key, const u8 raw_key[FCRYPT_BSIZE]);
+void fcrypt_pcbc_encrypt(const struct fcrypt_key *key,
+			 const u8 iv[FCRYPT_BSIZE], const void *src, void *dst,
+			 size_t nblocks);
+void fcrypt_pcbc_decrypt(const struct fcrypt_key *key,
+			 const u8 iv[FCRYPT_BSIZE], const void *src, void *dst,
+			 size_t nblocks);
+#if IS_ENABLED(CONFIG_KUNIT)
+struct des_ctx;
+void des_pcbc_decrypt_inplace(const struct des_ctx *key, __le64 iv, u8 *data,
+			      size_t len);
+#endif
+
+#define rxrpc_queue_work(WS)	queue_work(rxrpc_workqueue, (WS))
+#define rxrpc_queue_delayed_work(WS,D)	\
+	queue_delayed_work(rxrpc_workqueue, (WS), (D))
+
+struct key_preparsed_payload;
+struct rxrpc_connection;
+struct rxrpc_txbuf;
+struct rxrpc_txqueue;
+struct rxgk_context;
+
+/*
+ * Mark applied to socket buffers in skb->mark.  skb->priority is used
+ * to pass supplementary information.
+ */
+enum rxrpc_skb_mark {
+	RXRPC_SKB_MARK_PACKET,		/* Received packet */
+	RXRPC_SKB_MARK_ERROR,		/* Error notification */
+	RXRPC_SKB_MARK_CHALLENGE,	/* Challenge notification */
+	RXRPC_SKB_MARK_SERVICE_CONN_SECURED, /* Service connection response has been verified */
+	RXRPC_SKB_MARK_REJECT_BUSY,	/* Reject with BUSY */
+	RXRPC_SKB_MARK_REJECT_ABORT,	/* Reject with ABORT (code in skb->priority) */
+	RXRPC_SKB_MARK_REJECT_CONN_ABORT, /* Reject with connection ABORT (code in skb->priority) */
+};
+
+/*
+ * sk_state for RxRPC sockets
+ */
+enum {
+	RXRPC_UNBOUND = 0,
+	RXRPC_CLIENT_UNBOUND,		/* Unbound socket used as client */
+	RXRPC_CLIENT_BOUND,		/* client local address bound */
+	RXRPC_SERVER_BOUND,		/* server local address bound */
+	RXRPC_SERVER_BOUND2,		/* second server local address bound */
+	RXRPC_SERVER_LISTENING,		/* server listening for connections */
+	RXRPC_SERVER_LISTEN_DISABLED,	/* server listening disabled */
+	RXRPC_CLOSE,			/* socket is being closed */
+};
+
+/*
+ * Per-network namespace data.
+ */
+struct rxrpc_net {
+	struct proc_dir_entry	*proc_net;	/* Subdir in /proc/net */
+	u32			epoch;		/* Local epoch for detecting local-end reset */
+	struct list_head	calls;		/* List of calls active in this namespace */
+	spinlock_t		call_lock;	/* Lock for ->calls */
+	atomic_t		nr_calls;	/* Count of allocated calls */
+
+	atomic_t		nr_conns;
+	struct list_head	bundle_proc_list; /* List of bundles for proc */
+	struct list_head	conn_proc_list;	/* List of conns in this namespace for proc */
+	struct list_head	service_conns;	/* Service conns in this namespace */
+	rwlock_t		conn_lock;	/* Lock for ->conn_proc_list, ->service_conns */
+	struct work_struct	service_conn_reaper;
+	struct timer_list	service_conn_reap_timer;
+
+	bool			live;
+
+	atomic_t		nr_client_conns;
+
+	struct hlist_head	local_endpoints;
+	struct mutex		local_mutex;	/* Lock for ->local_endpoints */
+
+	DECLARE_HASHTABLE	(peer_hash, 10);
+	spinlock_t		peer_hash_lock;	/* Lock for ->peer_hash */
+
+#define RXRPC_KEEPALIVE_TIME 20 /* NAT keepalive time in seconds */
+	u8			peer_keepalive_cursor;
+	time64_t		peer_keepalive_base;
+	struct list_head	peer_keepalive[32];
+	struct list_head	peer_keepalive_new;
+	struct timer_list	peer_keepalive_timer;
+	struct work_struct	peer_keepalive_work;
+
+	atomic_t		stat_tx_data;
+	atomic_t		stat_tx_data_retrans;
+	atomic_t		stat_tx_data_send;
+	atomic_t		stat_tx_data_send_frag;
+	atomic_t		stat_tx_data_send_fail;
+	atomic_t		stat_tx_data_send_msgsize;
+	atomic_t		stat_tx_data_underflow;
+	atomic_t		stat_tx_data_cwnd_reset;
+	atomic_t		stat_rx_data;
+	atomic_t		stat_rx_data_reqack;
+	atomic_t		stat_rx_data_jumbo;
+
+	atomic_t		stat_tx_ack_fill;
+	atomic_t		stat_tx_ack_send;
+	atomic_t		stat_tx_ack_skip;
+	atomic_t		stat_tx_acks[256];
+	atomic_t		stat_rx_acks[256];
+	atomic_t		stat_tx_jumbo[10];
+	atomic_t		stat_rx_jumbo[10];
+
+	atomic_t		stat_why_req_ack[9];
+
+	atomic_t		stat_io_loop;
+};
+
+/*
+ * Service backlog preallocation.
+ *
+ * This contains circular buffers of preallocated peers, connections and calls
+ * for incoming service calls and their head and tail pointers.  This allows
+ * calls to be set up in the data_ready handler, thereby avoiding the need to
+ * shuffle packets around so much.
+ */
+struct rxrpc_backlog {
+	unsigned short		peer_backlog_head;
+	unsigned short		peer_backlog_tail;
+	unsigned short		conn_backlog_head;
+	unsigned short		conn_backlog_tail;
+	unsigned short		call_backlog_head;
+	unsigned short		call_backlog_tail;
+#define RXRPC_BACKLOG_MAX	32
+	struct rxrpc_peer	*peer_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_connection	*conn_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_call	*call_backlog[RXRPC_BACKLOG_MAX];
+};
+
+/*
+ * RxRPC socket definition
+ */
+struct rxrpc_sock {
+	/* WARNING: sk has to be the first member */
+	struct sock		sk;
+	const struct rxrpc_kernel_ops *app_ops;	/* Table of kernel app notification funcs */
+	struct rxrpc_local	*local;		/* local endpoint */
+	struct rxrpc_backlog	*backlog;	/* Preallocation for services */
+	struct sk_buff_head	recvmsg_oobq;	/* OOB messages for recvmsg to pick up */
+	struct rb_root		pending_oobq;	/* OOB messages awaiting userspace to respond to */
+	u64			oob_id_counter;	/* OOB message ID counter */
+	spinlock_t		incoming_lock;	/* Incoming call vs service shutdown lock */
+	struct list_head	sock_calls;	/* List of calls owned by this socket */
+	struct list_head	to_be_accepted;	/* calls awaiting acceptance */
+	struct list_head	recvmsg_q;	/* Calls awaiting recvmsg's attention  */
+	spinlock_t		recvmsg_lock;	/* Lock for recvmsg_q */
+	struct key		*key;		/* security for this socket */
+	struct key		*securities;	/* list of server security descriptors */
+	struct rb_root		calls;		/* User ID -> call mapping */
+	unsigned long		flags;
+#define RXRPC_SOCK_CONNECTED		0	/* connect_srx is set */
+#define RXRPC_SOCK_MANAGE_RESPONSE	1	/* User wants to manage RESPONSE packets */
+	rwlock_t		call_lock;	/* lock for calls */
+	u32			min_sec_level;	/* minimum security level */
+#define RXRPC_SECURITY_MAX	RXRPC_SECURITY_ENCRYPT
+	bool			exclusive;	/* Exclusive connection for a client socket */
+	u16			second_service;	/* Additional service bound to the endpoint */
+	struct {
+		/* Service upgrade information */
+		u16		from;		/* Service ID to upgrade (if not 0) */
+		u16		to;		/* service ID to upgrade to */
+	} service_upgrade;
+	sa_family_t		family;		/* Protocol family created with */
+	struct sockaddr_rxrpc	srx;		/* Primary Service/local addresses */
+	struct sockaddr_rxrpc	connect_srx;	/* Default client address from connect() */
+};
+
+#define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)
+
+/*
+ * CPU-byteorder normalised Rx packet header.
+ */
+struct rxrpc_host_header {
+	u32		epoch;		/* client boot timestamp */
+	u32		cid;		/* connection and channel ID */
+	u32		callNumber;	/* call ID (0 for connection-level packets) */
+	u32		seq;		/* sequence number of pkt in call stream */
+	u32		serial;		/* serial number of pkt sent to network */
+	u8		type;		/* packet type */
+	u8		flags;		/* packet flags */
+	u8		userStatus;	/* app-layer defined status */
+	u8		securityIndex;	/* security protocol ID */
+	union {
+		u16	_rsvd;		/* reserved */
+		u16	cksum;		/* kerberos security checksum */
+	};
+	u16		serviceId;	/* service ID */
+} __packed;
+
+/*
+ * RxRPC socket buffer private variables
+ * - max 48 bytes (struct sk_buff::cb)
+ */
+struct rxrpc_skb_priv {
+	union {
+		struct rxrpc_connection *poke_conn;	/* Conn referred to (poke packet) */
+		struct {
+			u16		offset;		/* Offset of data */
+			u16		len;		/* Length of data */
+		};
+		struct {
+			rxrpc_seq_t	first_ack;	/* First packet in acks table */
+			rxrpc_seq_t	prev_ack;	/* Highest seq seen */
+			rxrpc_serial_t	acked_serial;	/* Packet in response to (or 0) */
+			u16		nr_acks;	/* Number of acks+nacks */
+			u8		reason;		/* Reason for ack */
+		} ack;
+		struct {
+			struct rxrpc_connection *conn;	/* Connection referred to */
+			union {
+				u32 rxkad_nonce;
+			};
+		} chall;
+		struct {
+			rxrpc_serial_t	challenge_serial;
+			u32		kvno;
+			u32		version;
+			u16		len;
+			u16		ticket_len;
+		} resp;
+	};
+	struct rxrpc_host_header hdr;	/* RxRPC packet header from this packet */
+};
+
+#define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)
+
+/*
+ * RxRPC security module interface
+ */
+struct rxrpc_security {
+	const char		*name;		/* name of this service */
+	u8			security_index;	/* security type provided */
+	u32			no_key_abort;	/* Abort code indicating no key */
+
+	/* Initialise a security service */
+	int (*init)(void);
+
+	/* Clean up a security service */
+	void (*exit)(void);
+
+	/* Parse the information from a server key */
+	int (*preparse_server_key)(struct key_preparsed_payload *);
+
+	/* Clean up the preparse buffer after parsing a server key */
+	void (*free_preparse_server_key)(struct key_preparsed_payload *);
+
+	/* Destroy the payload of a server key */
+	void (*destroy_server_key)(struct key *);
+
+	/* Describe a server key */
+	void (*describe_server_key)(const struct key *, struct seq_file *);
+
+	/* initialise a connection's security */
+	int (*init_connection_security)(struct rxrpc_connection *,
+					struct rxrpc_key_token *);
+
+	/* Work out how much data we can store in a packet, given an estimate
+	 * of the amount of data remaining and allocate a data buffer.
+	 */
+	struct rxrpc_txbuf *(*alloc_txbuf)(struct rxrpc_call *call, size_t remaining, gfp_t gfp);
+
+	/* impose security on a packet */
+	int (*secure_packet)(struct rxrpc_call *, struct rxrpc_txbuf *);
+
+	/* verify the security on a received packet */
+	int (*verify_packet)(struct rxrpc_call *, struct sk_buff *);
+
+	/* Free crypto request on a call */
+	void (*free_call_crypto)(struct rxrpc_call *);
+
+	/* issue a challenge */
+	int (*issue_challenge)(struct rxrpc_connection *);
+
+	/* Validate a challenge packet */
+	bool (*validate_challenge)(struct rxrpc_connection *conn,
+				   struct sk_buff *skb);
+
+	/* Fill out the cmsg for recvmsg() to pass on a challenge to userspace.
+	 * The security class gets to add additional information.
+	 */
+	int (*challenge_to_recvmsg)(struct rxrpc_connection *conn,
+				    struct sk_buff *challenge,
+				    struct msghdr *msg);
+
+	/* Parse sendmsg() control message and respond to challenge. */
+	int (*sendmsg_respond_to_challenge)(struct sk_buff *challenge,
+					    struct msghdr *msg);
+
+	/* respond to a challenge */
+	int (*respond_to_challenge)(struct rxrpc_connection *conn,
+				    struct sk_buff *challenge);
+
+	/* verify a response */
+	int (*verify_response)(struct rxrpc_connection *conn,
+			       struct sk_buff *response_skb,
+			       void *response, unsigned int len);
+
+	/* clear connection security */
+	void (*clear)(struct rxrpc_connection *);
+
+	/* Default ticket -> key decoder */
+	int (*default_decode_ticket)(struct rxrpc_connection *conn, struct sk_buff *skb,
+				     void *ticket, unsigned int ticket_len,
+				     struct key **_key);
+};
+
+/*
+ * RxRPC local transport endpoint description
+ * - owned by a single AF_RXRPC socket
+ * - pointed to by transport socket struct sk_user_data
+ */
+struct rxrpc_local {
+	struct rcu_head		rcu;
+	atomic_t		active_users;	/* Number of users of the local endpoint */
+	refcount_t		ref;		/* Number of references to the structure */
+	struct net		*net;		/* The network namespace */
+	struct rxrpc_net	*rxnet;		/* Our bits in the network namespace */
+	struct hlist_node	link;
+	struct socket		*socket;	/* my UDP socket */
+	struct task_struct	*io_thread;
+	struct completion	io_thread_ready; /* Indication that the I/O thread started */
+	struct page_frag_cache	tx_alloc;	/* Tx control packet allocation (I/O thread only) */
+	struct rxrpc_sock	*service;	/* Service(s) listening on this endpoint */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	struct sk_buff_head	rx_delay_queue;	/* Delay injection queue */
+#endif
+	struct sk_buff_head	rx_queue;	/* Received packets */
+	struct list_head	conn_attend_q;	/* Conns requiring immediate attention */
+	struct list_head	call_attend_q;	/* Calls requiring immediate attention */
+
+	struct rb_root		client_bundles;	/* Client connection bundles by socket params */
+	spinlock_t		client_bundles_lock; /* Lock for client_bundles */
+	bool			kill_all_client_conns;
+	struct list_head	idle_client_conns;
+	struct timer_list	client_conn_reap_timer;
+	unsigned long		client_conn_flags;
+#define RXRPC_CLIENT_CONN_REAP_TIMER	0	/* The client conn reap timer expired */
+
+	spinlock_t		lock;		/* access lock */
+	rwlock_t		services_lock;	/* lock for services list */
+	int			debug_id;	/* debug ID for printks */
+	bool			dead;
+	bool			service_closed;	/* Service socket closed */
+	struct idr		conn_ids;	/* List of connection IDs */
+	struct list_head	new_client_calls; /* Newly created client calls need connection */
+	spinlock_t		client_call_lock; /* Lock for ->new_client_calls */
+	struct sockaddr_rxrpc	srx;		/* local address */
+	union {
+		/* Provide a kvec table sufficiently large to manage either a
+		 * DATA packet with a maximum set of jumbo subpackets or a PING
+		 * ACK padded out to 64K with zeropages for PMTUD.
+		 */
+		struct kvec		kvec[1 + RXRPC_MAX_NR_JUMBO > 3 + 16 ?
+					     1 + RXRPC_MAX_NR_JUMBO : 3 + 16];
+		struct bio_vec		bvec[3 + 16];
+	};
+};
+
+/*
+ * RxRPC remote transport endpoint definition
+ * - matched by local endpoint, remote port, address and protocol type
+ */
+struct rxrpc_peer {
+	struct rcu_head		rcu;		/* This must be first */
+	refcount_t		ref;
+	unsigned long		hash_key;
+	struct hlist_node	hash_link;
+	struct rxrpc_local	*local;
+	struct hlist_head	error_targets;	/* targets for net error distribution */
+	struct rb_root		service_conns;	/* Service connections */
+	struct list_head	keepalive_link;	/* Link in net->peer_keepalive[] */
+	unsigned long		app_data;	/* Application data (e.g. afs_server) */
+	unsigned int		last_tx_at;	/* Last time packet sent here (time64_t LSW) */
+	seqlock_t		service_conn_lock;
+	spinlock_t		lock;		/* access lock */
+	int			debug_id;	/* debug ID for printks */
+	struct sockaddr_rxrpc	srx;		/* remote address */
+
+	/* Path MTU discovery [RFC8899] */
+	unsigned int		pmtud_trial;	/* Current MTU probe size */
+	unsigned int		pmtud_good;	/* Largest working MTU probe we've tried */
+	unsigned int		pmtud_bad;	/* Smallest non-working MTU probe we've tried */
+	bool			pmtud_lost;	/* T if MTU probe was lost */
+	bool			pmtud_probing;	/* T if we have an active probe outstanding */
+	bool			pmtud_pending;	/* T if a call to this peer should send a probe */
+	u8			pmtud_jumbo;	/* Max jumbo packets for the MTU */
+	bool			ackr_adv_pmtud;	/* T if the peer advertises path-MTU */
+	unsigned int		ackr_max_data;	/* Maximum data advertised by peer */
+	unsigned int		if_mtu;		/* Local interface MTU (- hdrsize) for this peer */
+	unsigned int		max_data;	/* Maximum packet data capacity for this peer */
+	unsigned short		hdrsize;	/* header size (IP + UDP + RxRPC) */
+	unsigned short		tx_seg_max;	/* Maximum number of transmissable segments */
+
+	/* Calculated RTT cache */
+	unsigned int		recent_srtt_us;
+	unsigned int		recent_rto_us;
+
+	u8			cong_ssthresh;	/* Congestion slow-start threshold */
+};
+
+/*
+ * Keys for matching a connection.
+ */
+struct rxrpc_conn_proto {
+	union {
+		struct {
+			u32	epoch;		/* epoch of this connection */
+			u32	cid;		/* connection ID */
+		};
+		u64		index_key;
+	};
+};
+
+struct rxrpc_conn_parameters {
+	struct rxrpc_local	*local;		/* Representation of local endpoint */
+	struct rxrpc_peer	*peer;		/* Representation of remote endpoint */
+	struct key		*key;		/* Security details */
+	bool			exclusive;	/* T if conn is exclusive */
+	bool			upgrade;	/* T if service ID can be upgraded */
+	u16			service_id;	/* Service ID for this connection */
+	u32			security_level;	/* Security level selected */
+};
+
+/*
+ * Call completion condition (state == RXRPC_CALL_COMPLETE).
+ */
+enum rxrpc_call_completion {
+	RXRPC_CALL_SUCCEEDED,		/* - Normal termination */
+	RXRPC_CALL_REMOTELY_ABORTED,	/* - call aborted by peer */
+	RXRPC_CALL_LOCALLY_ABORTED,	/* - call aborted locally on error or close */
+	RXRPC_CALL_LOCAL_ERROR,		/* - call failed due to local error */
+	RXRPC_CALL_NETWORK_ERROR,	/* - call terminated by network error */
+	NR__RXRPC_CALL_COMPLETIONS
+};
+
+/*
+ * Bits in the connection flags.
+ */
+enum rxrpc_conn_flag {
+	RXRPC_CONN_IN_SERVICE_CONNS,	/* Conn is in peer->service_conns */
+	RXRPC_CONN_DONT_REUSE,		/* Don't reuse this connection */
+	RXRPC_CONN_PROBING_FOR_UPGRADE,	/* Probing for service upgrade */
+	RXRPC_CONN_FINAL_ACK_0,		/* Need final ACK for channel 0 */
+	RXRPC_CONN_FINAL_ACK_1,		/* Need final ACK for channel 1 */
+	RXRPC_CONN_FINAL_ACK_2,		/* Need final ACK for channel 2 */
+	RXRPC_CONN_FINAL_ACK_3,		/* Need final ACK for channel 3 */
+};
+
+#define RXRPC_CONN_FINAL_ACK_MASK ((1UL << RXRPC_CONN_FINAL_ACK_0) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_1) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_2) |	\
+				   (1UL << RXRPC_CONN_FINAL_ACK_3))
+
+/*
+ * Events that can be raised upon a connection.
+ */
+enum rxrpc_conn_event {
+	RXRPC_CONN_EV_CHALLENGE,	/* Send challenge packet */
+	RXRPC_CONN_EV_ABORT_CALLS,	/* Abort attached calls */
+};
+
+/*
+ * The connection protocol state.
+ */
+enum rxrpc_conn_proto_state {
+	RXRPC_CONN_UNUSED,		/* Connection not yet attempted */
+	RXRPC_CONN_CLIENT_UNSECURED,	/* Client connection needs security init */
+	RXRPC_CONN_CLIENT,		/* Client connection */
+	RXRPC_CONN_SERVICE_PREALLOC,	/* Service connection preallocation */
+	RXRPC_CONN_SERVICE_UNSECURED,	/* Service unsecured connection */
+	RXRPC_CONN_SERVICE_CHALLENGING,	/* Service challenging for security */
+	RXRPC_CONN_SERVICE,		/* Service secured connection */
+	RXRPC_CONN_ABORTED,		/* Conn aborted */
+	RXRPC_CONN__NR_STATES
+};
+
+/*
+ * RxRPC client connection bundle.
+ */
+struct rxrpc_bundle {
+	struct rxrpc_local	*local;		/* Representation of local endpoint */
+	struct rxrpc_peer	*peer;		/* Remote endpoint */
+	struct key		*key;		/* Security details */
+	struct list_head	proc_link;	/* Link in net->bundle_proc_list */
+	const struct rxrpc_security *security;	/* applied security module */
+	refcount_t		ref;
+	atomic_t		active;		/* Number of active users */
+	unsigned int		debug_id;
+	u32			security_level;	/* Security level selected */
+	u16			service_id;	/* Service ID for this connection */
+	bool			try_upgrade;	/* True if the bundle is attempting upgrade */
+	bool			exclusive;	/* T if conn is exclusive */
+	bool			upgrade;	/* T if service ID can be upgraded */
+	unsigned short		alloc_error;	/* Error from last conn allocation */
+	struct rb_node		local_node;	/* Node in local->client_conns */
+	struct list_head	waiting_calls;	/* Calls waiting for channels */
+	unsigned long		avail_chans;	/* Mask of available channels */
+	unsigned int		conn_ids[4];	/* Connection IDs. */
+	struct rxrpc_connection	*conns[4];	/* The connections in the bundle (max 4) */
+};
+
+/*
+ * RxRPC connection definition
+ * - matched by { local, peer, epoch, conn_id, direction }
+ * - each connection can only handle four simultaneous calls
+ */
+struct rxrpc_connection {
+	struct rxrpc_conn_proto	proto;
+	struct rxrpc_local	*local;		/* Representation of local endpoint */
+	struct rxrpc_peer	*peer;		/* Remote endpoint */
+	struct rxrpc_net	*rxnet;		/* Network namespace to which call belongs */
+	struct key		*key;		/* Security details */
+	struct list_head	attend_link;	/* Link in local->conn_attend_q */
+
+	refcount_t		ref;
+	atomic_t		active;		/* Active count for service conns */
+	struct rcu_head		rcu;
+	struct list_head	cache_link;
+
+	unsigned char		act_chans;	/* Mask of active channels */
+	struct rxrpc_channel {
+		unsigned long		final_ack_at;	/* Time at which to issue final ACK */
+		struct rxrpc_call	*call;		/* Active call */
+		unsigned int		call_debug_id;	/* call->debug_id */
+		u32			call_id;	/* ID of current call */
+		u32			call_counter;	/* Call ID counter */
+		u32			last_call;	/* ID of last call */
+		u8			last_type;	/* Type of last packet */
+		union {
+			u32		last_seq;
+			u32		last_abort;
+		};
+	} channels[RXRPC_MAXCALLS];
+
+	struct timer_list	timer;		/* Conn event timer */
+	struct work_struct	processor;	/* connection event processor */
+	struct work_struct	destructor;	/* In-process-context destroyer */
+	struct rxrpc_bundle	*bundle;	/* Client connection bundle */
+	struct rb_node		service_node;	/* Node in peer->service_conns */
+	struct list_head	proc_link;	/* link in procfs list */
+	struct list_head	link;		/* link in master connection list */
+	struct sk_buff_head	rx_queue;	/* received conn-level packets */
+	struct page_frag_cache	tx_data_alloc;	/* Tx DATA packet allocation */
+	struct mutex		tx_data_alloc_lock;
+
+	struct mutex		security_lock;	/* Lock for security management */
+	const struct rxrpc_security *security;	/* applied security module */
+	union {
+		struct {
+			struct fcrypt_key *cipher; /* encryption key */
+			struct rxrpc_crypt csum_iv;	/* packet checksum base */
+			u32	nonce;		/* response re-use preventer */
+		} rxkad;
+		struct {
+			struct rxgk_context *keys[4]; /* (Re-)keying buffer */
+			u64	start_time;	/* The start time for TK derivation */
+			u8	nonce[20];	/* Response re-use preventer */
+			u32	enctype;	/* Kerberos 5 encoding type */
+			u32	key_number;	/* Current key number */
+		} rxgk;
+	};
+	rwlock_t		security_use_lock; /* Security use/modification lock */
+	struct sk_buff		*tx_response;	/* Response packet to be transmitted */
+
+	unsigned long		flags;
+	unsigned long		events;
+	unsigned long		idle_timestamp;	/* Time at which last became idle */
+	spinlock_t		state_lock;	/* state-change lock */
+	enum rxrpc_conn_proto_state state;	/* current state of connection */
+	enum rxrpc_call_completion completion;	/* Completion condition */
+	s32			abort_code;	/* Abort code of connection abort */
+	int			debug_id;	/* debug ID for printks */
+	rxrpc_serial_t		tx_serial;	/* Outgoing packet serial number counter */
+	unsigned int		hi_serial;	/* highest serial number received */
+	rxrpc_serial_t		pmtud_probe;	/* Serial of MTU probe (or 0) */
+	unsigned int		pmtud_call;	/* ID of call used for probe */
+	u32			service_id;	/* Service ID, possibly upgraded */
+	u32			security_level;	/* Security level selected */
+	u8			security_ix;	/* security type */
+	u8			out_clientflag;	/* RXRPC_CLIENT_INITIATED if we are client */
+	u8			bundle_shift;	/* Index into bundle->avail_chans */
+	bool			exclusive;	/* T if conn is exclusive */
+	bool			upgrade;	/* T if service ID can be upgraded */
+	u16			orig_service_id; /* Originally requested service ID */
+	short			error;		/* Local error code */
+};
+
+static inline bool rxrpc_to_server(const struct rxrpc_skb_priv *sp)
+{
+	return sp->hdr.flags & RXRPC_CLIENT_INITIATED;
+}
+
+static inline bool rxrpc_to_client(const struct rxrpc_skb_priv *sp)
+{
+	return !rxrpc_to_server(sp);
+}
+
+/*
+ * Flags in call->flags.
+ */
+enum rxrpc_call_flag {
+	RXRPC_CALL_RELEASED,		/* call has been released - no more message to userspace */
+	RXRPC_CALL_HAS_USERID,		/* has a user ID attached */
+	RXRPC_CALL_IS_SERVICE,		/* Call is service call */
+	RXRPC_CALL_EXPOSED,		/* The call was exposed to the world */
+	RXRPC_CALL_RX_LAST,		/* Received the last packet (at rxtx_top) */
+	RXRPC_CALL_TX_LAST,		/* Last packet in Tx buffer (at rxtx_top) */
+	RXRPC_CALL_TX_ALL_ACKED,	/* Last packet has been hard-acked */
+	RXRPC_CALL_TX_NO_MORE,		/* No more data to transmit (MSG_MORE deasserted) */
+	RXRPC_CALL_SEND_PING,		/* A ping will need to be sent */
+	RXRPC_CALL_RETRANS_TIMEOUT,	/* Retransmission due to timeout occurred */
+	RXRPC_CALL_BEGAN_RX_TIMER,	/* We began the expect_rx_by timer */
+	RXRPC_CALL_RX_HEARD,		/* The peer responded at least once to this call */
+	RXRPC_CALL_DISCONNECTED,	/* The call has been disconnected */
+	RXRPC_CALL_KERNEL,		/* The call was made by the kernel */
+	RXRPC_CALL_UPGRADE,		/* Service upgrade was requested for the call */
+	RXRPC_CALL_EXCLUSIVE,		/* The call uses a once-only connection */
+	RXRPC_CALL_RX_IS_IDLE,		/* recvmsg() is idle - send an ACK */
+	RXRPC_CALL_RECVMSG_READ_ALL,	/* recvmsg() read all of the received data */
+	RXRPC_CALL_CONN_CHALLENGING,	/* The connection is being challenged */
+};
+
+/*
+ * Events that can be raised on a call.
+ */
+enum rxrpc_call_event {
+	RXRPC_CALL_EV_ACK_LOST,		/* ACK may be lost, send ping */
+	RXRPC_CALL_EV_INITIAL_PING,	/* Send initial ping for a new service call */
+};
+
+/*
+ * The states that a call can be in.
+ */
+enum rxrpc_call_state {
+	RXRPC_CALL_UNINITIALISED,
+	RXRPC_CALL_CLIENT_AWAIT_CONN,	/* - client waiting for connection to become available */
+	RXRPC_CALL_CLIENT_PRE_SEND,	/* - client is connected, but hasn't sent anything yet */
+	RXRPC_CALL_CLIENT_SEND_REQUEST,	/* - client sending request phase */
+	RXRPC_CALL_CLIENT_AWAIT_ACK,	/* - client awaiting ACKs of request */
+	RXRPC_CALL_CLIENT_AWAIT_REPLY,	/* - client awaiting reply */
+	RXRPC_CALL_CLIENT_RECV_REPLY,	/* - client receiving reply phase */
+	RXRPC_CALL_SERVER_PREALLOC,	/* - service preallocation */
+	RXRPC_CALL_SERVER_RECV_REQUEST,	/* - server receiving request */
+	RXRPC_CALL_SERVER_ACK_REQUEST,	/* - server pending ACK of request */
+	RXRPC_CALL_SERVER_SEND_REPLY,	/* - server sending reply */
+	RXRPC_CALL_SERVER_AWAIT_ACK,	/* - server awaiting final ACK */
+	RXRPC_CALL_COMPLETE,		/* - call complete */
+	NR__RXRPC_CALL_STATES
+};
+
+/*
+ * Call Tx congestion management modes.
+ */
+enum rxrpc_ca_state {
+	RXRPC_CA_SLOW_START,
+	RXRPC_CA_CONGEST_AVOIDANCE,
+	RXRPC_CA_PACKET_LOSS,
+	RXRPC_CA_FAST_RETRANSMIT,
+	NR__RXRPC_CA_STATES
+} __mode(byte);
+
+/*
+ * Current purpose of call RACK timer.  According to the RACK-TLP protocol
+ * [RFC8985], the transmission timer (call->rack_timo_at) may only be used for
+ * one of these at once.
+ */
+enum rxrpc_rack_timer_mode {
+	RXRPC_CALL_RACKTIMER_OFF,		/* Timer not running */
+	RXRPC_CALL_RACKTIMER_RACK_REORDER,	/* RACK reordering timer */
+	RXRPC_CALL_RACKTIMER_TLP_PTO,		/* TLP timeout */
+	RXRPC_CALL_RACKTIMER_RTO,		/* Retransmission timeout */
+} __mode(byte);
+
+/*
+ * RxRPC call definition
+ * - matched by { connection, call_id }
+ */
+struct rxrpc_call {
+	struct rcu_head		rcu;
+	struct rxrpc_connection	*conn;		/* connection carrying call */
+	struct rxrpc_bundle	*bundle;	/* Connection bundle to use */
+	struct rxrpc_peer	*peer;		/* Peer record for remote address */
+	struct rxrpc_local	*local;		/* Representation of local endpoint */
+	struct rxrpc_sock __rcu	*socket;	/* socket responsible */
+	struct rxrpc_net	*rxnet;		/* Network namespace to which call belongs */
+	struct key		*key;		/* Security details */
+	const struct rxrpc_security *security;	/* applied security module */
+	struct mutex		user_mutex;	/* User access mutex */
+	struct sockaddr_rxrpc	dest_srx;	/* Destination address */
+	ktime_t			delay_ack_at;	/* When DELAY ACK needs to happen */
+	ktime_t			rack_timo_at;	/* When ACK is figured as lost */
+	ktime_t			ping_at;	/* When next to send a ping */
+	ktime_t			keepalive_at;	/* When next to send a keepalive ping */
+	ktime_t			expect_rx_by;	/* When we expect to get a packet by */
+	ktime_t			expect_req_by;	/* When we expect to get a request DATA packet by */
+	ktime_t			expect_term_by;	/* When we expect call termination by */
+	u32			next_rx_timo;	/* Timeout for next Rx packet (ms) */
+	u32			next_req_timo;	/* Timeout for next Rx request packet (ms) */
+	u32			hard_timo;	/* Maximum lifetime or 0 (s) */
+	struct timer_list	timer;		/* Combined event timer */
+	struct work_struct	destroyer;	/* In-process-context destroyer */
+	rxrpc_notify_rx_t	notify_rx;	/* kernel service Rx notification function */
+	struct list_head	link;		/* link in master call list */
+	struct list_head	wait_link;	/* Link in local->new_client_calls */
+	struct hlist_node	error_link;	/* link in error distribution list */
+	struct list_head	accept_link;	/* Link in rx->acceptq */
+	struct list_head	recvmsg_link;	/* Link in rx->recvmsg_q */
+	struct list_head	sock_link;	/* Link in rx->sock_calls */
+	struct rb_node		sock_node;	/* Node in rx->calls */
+	struct list_head	attend_link;	/* Link in local->call_attend_q */
+	struct rxrpc_txbuf	*tx_pending;	/* Tx buffer being filled */
+	wait_queue_head_t	waitq;		/* Wait queue for channel or Tx */
+	s64			tx_total_len;	/* Total length left to be transmitted (or -1) */
+	unsigned long		user_call_ID;	/* user-defined call ID */
+	unsigned long		flags;
+	unsigned long		events;
+	spinlock_t		notify_lock;	/* Kernel notification lock */
+	unsigned int		send_abort_why; /* Why the abort [enum rxrpc_abort_reason] */
+	s32			send_abort;	/* Abort code to be sent */
+	short			send_abort_err;	/* Error to be associated with the abort */
+	rxrpc_seq_t		send_abort_seq;	/* DATA packet that incurred the abort (or 0) */
+	s32			abort_code;	/* Local/remote abort code */
+	int			error;		/* Local error incurred */
+	enum rxrpc_call_state	_state;		/* Current state of call (needs barrier) */
+	enum rxrpc_call_completion completion;	/* Call completion condition */
+	refcount_t		ref;
+	u8			security_ix;	/* Security type */
+	enum rxrpc_interruptibility interruptibility; /* At what point call may be interrupted */
+	u32			call_id;	/* call ID on connection  */
+	u32			cid;		/* connection ID plus channel index */
+	u32			security_level;	/* Security level selected */
+	u32			security_enctype; /* Security-specific encoding type (or 0) */
+	int			debug_id;	/* debug ID for printks */
+	unsigned short		rx_pkt_offset;	/* Current recvmsg packet offset */
+	unsigned short		rx_pkt_len;	/* Current recvmsg packet len */
+
+	/* Sendmsg data tracking. */
+	rxrpc_seq_t		send_top;	/* Highest Tx slot filled by sendmsg. */
+	struct rxrpc_txqueue	*send_queue;	/* Queue that sendmsg is writing into */
+
+	/* Transmitted data tracking. */
+	struct rxrpc_txqueue	*tx_queue;	/* Start of transmission buffers */
+	struct rxrpc_txqueue	*tx_qtail;	/* End of transmission buffers */
+	rxrpc_seq_t		tx_qbase;	/* First slot in tx_queue */
+	rxrpc_seq_t		tx_bottom;	/* First packet in buffer */
+	rxrpc_seq_t		tx_transmitted;	/* Highest packet transmitted */
+	rxrpc_seq_t		tx_top;		/* Highest Tx slot allocated. */
+	rxrpc_serial_t		tx_last_serial;	/* Serial of last DATA transmitted */
+	u16			tx_backoff;	/* Delay to insert due to Tx failure (ms) */
+	u16			tx_nr_sent;	/* Number of packets sent, but unacked */
+	u16			tx_nr_lost;	/* Number of packets marked lost */
+	u16			tx_nr_resent;	/* Number of packets resent, but unacked */
+	u16			tx_winsize;	/* Maximum size of Tx window */
+#define RXRPC_TX_MAX_WINDOW	128
+	u8			tx_jumbo_max;	/* Maximum subpkts peer will accept */
+	ktime_t			tx_last_sent;	/* Last time a transmission occurred */
+
+	/* Received data tracking */
+	struct sk_buff_head	recvmsg_queue;	/* Queue of packets ready for recvmsg() */
+	struct sk_buff_head	rx_queue;	/* Queue of packets for this call to receive */
+	struct sk_buff_head	rx_oos_queue;	/* Queue of out of sequence packets */
+	void			*rx_dec_buffer;	/* Decryption buffer */
+	unsigned short		rx_dec_bsize;	/* rx_dec_buffer size */
+	unsigned short		rx_dec_offset;	/* Decrypted packet data offset */
+	unsigned short		rx_dec_len;	/* Decrypted packet data len */
+	rxrpc_seq_t		rx_dec_seq;	/* Packet in decryption buffer */
+
+	rxrpc_seq_t		rx_highest_seq;	/* Higest sequence number received */
+	rxrpc_seq_t		rx_consumed;	/* Highest packet consumed */
+	rxrpc_serial_t		rx_serial;	/* Highest serial received for this call */
+	u8			rx_winsize;	/* Size of Rx window */
+
+	/* TCP-style slow-start congestion control [RFC5681].  Since the SMSS
+	 * is fixed, we keep these numbers in terms of segments (ie. DATA
+	 * packets) rather than bytes.
+	 */
+#define RXRPC_TX_SMSS		RXRPC_JUMBO_DATALEN
+#define RXRPC_MIN_CWND		4
+	enum rxrpc_ca_state	cong_ca_state;	/* Congestion control state */
+	u8			cong_extra;	/* Extra to send for congestion management */
+	u16			cong_cwnd;	/* Congestion window size */
+	u16			cong_ssthresh;	/* Slow-start threshold */
+	u16			cong_dup_acks;	/* Count of ACKs showing missing packets */
+	u16			cong_cumul_acks; /* Cumulative ACK count */
+	ktime_t			cong_tstamp;	/* Last time cwnd was changed */
+
+	/* RACK-TLP [RFC8985] state. */
+	ktime_t			rack_xmit_ts;	/* Latest transmission timestamp */
+	ktime_t			rack_rtt;	/* RTT of most recently ACK'd segment */
+	ktime_t			rack_rtt_ts;	/* Timestamp of rack_rtt */
+	ktime_t			rack_reo_wnd;	/* Reordering window */
+	unsigned int		rack_reo_wnd_mult; /* Multiplier applied to rack_reo_wnd */
+	int			rack_reo_wnd_persist; /* Num loss recoveries before reset reo_wnd */
+	rxrpc_seq_t		rack_fack;	/* Highest sequence so far ACK'd */
+	rxrpc_seq_t		rack_end_seq;	/* Highest sequence seen */
+	rxrpc_seq_t		rack_dsack_round; /* DSACK opt recv'd in latest roundtrip */
+	bool			rack_dsack_round_none; /* T if dsack_round is "None" */
+	bool			rack_reordering_seen; /* T if detected reordering event */
+	enum rxrpc_rack_timer_mode rack_timer_mode; /* Current mode of RACK timer */
+	bool			tlp_is_retrans;	/* T if unacked TLP retransmission */
+	rxrpc_serial_t		tlp_serial;	/* Serial of TLP probe (or 0 if none in progress) */
+	rxrpc_seq_t		tlp_seq;	/* Sequence of TLP probe */
+	unsigned int		tlp_rtt_taken;	/* Last time RTT taken */
+	ktime_t			tlp_max_ack_delay; /* Sender budget for max delayed ACK interval */
+
+	/* Receive-phase ACK management (ACKs we send). */
+	u8			ackr_reason;	/* reason to ACK */
+	u16			ackr_sack_base;	/* Starting slot in SACK table ring */
+	rxrpc_seq_t		ackr_window;	/* Base of SACK window */
+	rxrpc_seq_t		ackr_wtop;	/* Base of SACK window */
+	unsigned int		ackr_nr_unacked; /* Number of unacked packets */
+	atomic_t		ackr_nr_consumed; /* Number of packets needing hard ACK */
+	struct {
+#define RXRPC_SACK_SIZE 256
+		 /* SACK table for soft-acked packets */
+		u8		ackr_sack_table[RXRPC_SACK_SIZE];
+	} __aligned(8);
+
+	/* RTT management */
+	rxrpc_serial_t		rtt_serial[4];	/* Serial number of DATA or PING sent */
+	ktime_t			rtt_sent_at[4];	/* Time packet sent */
+	unsigned long		rtt_avail;	/* Mask of available slots in bits 0-3,
+						 * Mask of pending samples in 8-11 */
+#define RXRPC_CALL_RTT_AVAIL_MASK	0xf
+#define RXRPC_CALL_RTT_PEND_SHIFT	8
+
+	/* Transmission-phase ACK management (ACKs we've received). */
+	ktime_t			acks_latest_ts;	/* Timestamp of latest ACK received */
+	rxrpc_seq_t		acks_hard_ack;	/* Highest sequence hard acked */
+	rxrpc_seq_t		acks_prev_seq;	/* Highest previousPacket received */
+	rxrpc_seq_t		acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */
+	rxrpc_serial_t		acks_highest_serial; /* Highest serial number ACK'd */
+	unsigned short		acks_nr_sacks;	/* Number of soft acks recorded */
+	unsigned short		acks_nr_snacks;	/* Number of soft nacks recorded */
+
+	/* Calculated RTT cache */
+	ktime_t			rtt_last_req;	/* Time of last RTT request */
+	unsigned int		rtt_count;	/* Number of samples we've got */
+	unsigned int		rtt_taken;	/* Number of samples taken (wrapping) */
+	struct minmax		min_rtt;	/* Estimated minimum RTT */
+	u32			srtt_us;	/* smoothed round trip time << 3 in usecs */
+	u32			mdev_us;	/* medium deviation			*/
+	u32			mdev_max_us;	/* maximal mdev for the last rtt period	*/
+	u32			rttvar_us;	/* smoothed mdev_max			*/
+	u32			rto_us;		/* Retransmission timeout in usec */
+	u8			backoff;	/* Backoff timeout (as shift) */
+};
+
+/*
+ * Summary of a new ACK and the changes it made to the Tx buffer packet states.
+ */
+struct rxrpc_ack_summary {
+	rxrpc_serial_t	ack_serial;		/* Serial number of ACK */
+	rxrpc_serial_t	acked_serial;		/* Serial number ACK'd */
+	u16		in_flight;		/* Number of unreceived transmissions */
+	u16		nr_new_hacks;		/* Number of rotated new ACKs */
+	u16		nr_new_sacks;		/* Number of new soft ACKs in packet */
+	u16		nr_new_snacks;		/* Number of new soft nacks in packet */
+	u8		ack_reason;
+	bool		new_low_snack:1;	/* T if new low soft NACK found */
+	bool		retrans_timeo:1;	/* T if reTx due to timeout happened */
+	bool		need_retransmit:1;	/* T if we need transmission */
+	bool		rtt_sample_avail:1;	/* T if RTT sample available */
+	bool		in_fast_or_rto_recovery:1;
+	bool		exiting_fast_or_rto_recovery:1;
+	bool		tlp_probe_acked:1;	/* T if the TLP probe seq was acked */
+	u8 /*enum rxrpc_congest_change*/ change;
+};
+
+/*
+ * sendmsg() cmsg-specified parameters.
+ */
+enum rxrpc_command {
+	RXRPC_CMD_SEND_DATA,		/* send data message */
+	RXRPC_CMD_SEND_ABORT,		/* request abort generation */
+	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */
+	RXRPC_CMD_CHARGE_ACCEPT,	/* [server] charge accept preallocation */
+};
+
+struct rxrpc_call_params {
+	s64			tx_total_len;	/* Total Tx data length (if send data) */
+	unsigned long		user_call_ID;	/* User's call ID */
+	struct {
+		u32		hard;		/* Maximum lifetime (sec) */
+		u32		idle;		/* Max time since last data packet (msec) */
+		u32		normal;		/* Max time since last call packet (msec) */
+	} timeouts;
+	u8			nr_timeouts;	/* Number of timeouts specified */
+	bool			kernel;		/* T if kernel is making the call */
+	enum rxrpc_interruptibility interruptibility; /* How is interruptible is the call? */
+};
+
+struct rxrpc_send_params {
+	struct rxrpc_call_params call;
+	u32			abort_code;	/* Abort code to Tx (if abort) */
+	enum rxrpc_command	command : 8;	/* The command to implement */
+	bool			exclusive;	/* Shared or exclusive call */
+	bool			upgrade;	/* If the connection is upgradeable */
+};
+
+/*
+ * Buffer of data to be output as a packet.
+ */
+struct rxrpc_txbuf {
+	refcount_t		ref;
+	rxrpc_seq_t		seq;		/* Sequence number of this packet */
+	rxrpc_serial_t		serial;		/* Last serial number transmitted with */
+	unsigned int		call_debug_id;
+	unsigned int		debug_id;
+	unsigned short		len;		/* Amount of data in buffer */
+	unsigned short		space;		/* Remaining data space */
+	unsigned short		offset;		/* Offset of fill point */
+	unsigned short		crypto_header;	/* Size of crypto header */
+	unsigned short		sec_header;	/* Size of security header */
+	unsigned short		pkt_len;	/* Size of packet content */
+	unsigned short		alloc_size;	/* Amount of bufferage allocated */
+	unsigned int		flags;
+#define RXRPC_TXBUF_WIRE_FLAGS	0xff		/* The wire protocol flags */
+#define RXRPC_TXBUF_RESENT	0x100		/* Set if has been resent */
+	__be16			cksum;		/* Checksum to go in header */
+	bool			jumboable;	/* Can be non-terminal jumbo subpacket */
+	void			*data;		/* Data with preceding jumbo header */
+};
+
+static inline bool rxrpc_sending_to_server(const struct rxrpc_txbuf *txb)
+{
+	return txb->flags & RXRPC_CLIENT_INITIATED;
+}
+
+static inline bool rxrpc_sending_to_client(const struct rxrpc_txbuf *txb)
+{
+	return !rxrpc_sending_to_server(txb);
+}
+
+/*
+ * Transmit queue element, including RACK [RFC8985] per-segment metadata.  The
+ * transmission timestamp is in usec from the base.
+ */
+struct rxrpc_txqueue {
+	/* Start with the members we want to prefetch. */
+	struct rxrpc_txqueue	*next;
+	ktime_t			xmit_ts_base;
+	rxrpc_seq_t		qbase;
+	u8			nr_reported_acks; /* Number of segments explicitly acked/nacked */
+	unsigned long		segment_acked;	/* Bit-per-buf: Set if ACK'd */
+	unsigned long		segment_lost;	/* Bit-per-buf: Set if declared lost */
+	unsigned long		segment_retransmitted; /* Bit-per-buf: Set if retransmitted */
+	unsigned long		rtt_samples;	/* Bit-per-buf: Set if available for RTT */
+	unsigned long		ever_retransmitted; /* Bit-per-buf: Set if ever retransmitted */
+
+	/* The arrays we want to pack into as few cache lines as possible. */
+	struct {
+#define RXRPC_NR_TXQUEUE BITS_PER_LONG
+#define RXRPC_TXQ_MASK (RXRPC_NR_TXQUEUE - 1)
+		struct rxrpc_txbuf *bufs[RXRPC_NR_TXQUEUE];
+		unsigned int	segment_serial[RXRPC_NR_TXQUEUE];
+		unsigned int	segment_xmit_ts[RXRPC_NR_TXQUEUE];
+	} ____cacheline_aligned;
+};
+
+/*
+ * Data transmission request.
+ */
+struct rxrpc_send_data_req {
+	ktime_t			now;		/* Current time */
+	struct rxrpc_txqueue	*tq;		/* Tx queue segment holding first DATA */
+	rxrpc_seq_t		seq;		/* Sequence of first data */
+	int			n;		/* Number of DATA packets to glue into jumbo */
+	bool			retrans;	/* T if this is a retransmission */
+	bool			did_send;	/* T if did actually send */
+	bool			tlp_probe;	/* T if this is a TLP probe */
+	int /* enum rxrpc_txdata_trace */ trace;
+};
+
+#include <trace/events/rxrpc.h>
+
+/*
+ * Allocate the next serial number on a connection.  0 must be skipped.
+ */
+static inline rxrpc_serial_t rxrpc_get_next_serial(struct rxrpc_connection *conn)
+{
+	rxrpc_serial_t serial;
+
+	serial = conn->tx_serial;
+	if (serial == 0)
+		serial = 1;
+	conn->tx_serial = serial + 1;
+	return serial;
+}
+
+/*
+ * Allocate the next serial n numbers on a connection.  0 must be skipped.
+ */
+static inline rxrpc_serial_t rxrpc_get_next_serials(struct rxrpc_connection *conn,
+						    unsigned int n)
+{
+	rxrpc_serial_t serial;
+
+	serial = conn->tx_serial;
+	if (serial + n <= n)
+		serial = 1;
+	conn->tx_serial = serial + n;
+	return serial;
+}
+
+/*
+ * af_rxrpc.c
+ */
+extern atomic_t rxrpc_n_rx_skbs;
+extern struct workqueue_struct *rxrpc_workqueue;
+
+/*
+ * call_accept.c
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *, gfp_t);
+void rxrpc_discard_prealloc(struct rxrpc_sock *);
+bool rxrpc_new_incoming_call(struct rxrpc_local *local,
+			     struct rxrpc_peer *peer,
+			     struct rxrpc_connection *conn,
+			     struct sockaddr_rxrpc *peer_srx,
+			     struct sk_buff *skb);
+int rxrpc_user_charge_accept(struct rxrpc_sock *, unsigned long);
+
+/*
+ * call_event.c
+ */
+void rxrpc_propose_ping(struct rxrpc_call *call, u32 serial,
+			enum rxrpc_propose_ack_trace why);
+void rxrpc_propose_delay_ACK(struct rxrpc_call *, rxrpc_serial_t,
+			     enum rxrpc_propose_ack_trace);
+void rxrpc_resend_tlp(struct rxrpc_call *call);
+void rxrpc_transmit_some_data(struct rxrpc_call *call, unsigned int limit,
+			      enum rxrpc_txdata_trace trace);
+bool rxrpc_input_call_event(struct rxrpc_call *call);
+
+/*
+ * call_object.c
+ */
+extern const char *const rxrpc_call_states[];
+extern const char *const rxrpc_call_completions[];
+extern struct kmem_cache *rxrpc_call_jar;
+
+void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what);
+struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long);
+struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *, gfp_t, unsigned int);
+struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *,
+					 struct rxrpc_conn_parameters *,
+					 struct rxrpc_call_params *, gfp_t,
+					 unsigned int)
+	__releases(&rx->sk.sk_lock)
+	__acquires(&call->user_mutex);
+void rxrpc_start_call_timer(struct rxrpc_call *call);
+void rxrpc_incoming_call(struct rxrpc_sock *, struct rxrpc_call *,
+			 struct sk_buff *);
+void rxrpc_release_call(struct rxrpc_sock *, struct rxrpc_call *);
+void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
+void rxrpc_see_call(struct rxrpc_call *, enum rxrpc_call_trace);
+struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *, enum rxrpc_call_trace);
+void rxrpc_get_call(struct rxrpc_call *, enum rxrpc_call_trace);
+void rxrpc_put_call(struct rxrpc_call *, enum rxrpc_call_trace);
+void rxrpc_cleanup_call(struct rxrpc_call *);
+void rxrpc_destroy_all_calls(struct rxrpc_net *);
+
+static inline bool rxrpc_is_service_call(const struct rxrpc_call *call)
+{
+	return test_bit(RXRPC_CALL_IS_SERVICE, &call->flags);
+}
+
+static inline bool rxrpc_is_client_call(const struct rxrpc_call *call)
+{
+	return !rxrpc_is_service_call(call);
+}
+
+/*
+ * call_state.c
+ */
+bool rxrpc_set_call_completion(struct rxrpc_call *call,
+			       enum rxrpc_call_completion compl,
+			       u32 abort_code,
+			       int error);
+bool rxrpc_call_completed(struct rxrpc_call *call);
+bool rxrpc_abort_call(struct rxrpc_call *call, rxrpc_seq_t seq,
+		      u32 abort_code, int error, enum rxrpc_abort_reason why);
+void rxrpc_prefail_call(struct rxrpc_call *call, enum rxrpc_call_completion compl,
+			int error);
+
+static inline void rxrpc_set_call_state(struct rxrpc_call *call,
+					enum rxrpc_call_state state)
+{
+	/* Order write of completion info before write of ->state. */
+	smp_store_release(&call->_state, state);
+	wake_up(&call->waitq);
+}
+
+static inline enum rxrpc_call_state __rxrpc_call_state(const struct rxrpc_call *call)
+{
+	return call->_state; /* Only inside I/O thread */
+}
+
+static inline bool __rxrpc_call_is_complete(const struct rxrpc_call *call)
+{
+	return __rxrpc_call_state(call) == RXRPC_CALL_COMPLETE;
+}
+
+static inline enum rxrpc_call_state rxrpc_call_state(const struct rxrpc_call *call)
+{
+	/* Order read ->state before read of completion info. */
+	return smp_load_acquire(&call->_state);
+}
+
+static inline bool rxrpc_call_is_complete(const struct rxrpc_call *call)
+{
+	return rxrpc_call_state(call) == RXRPC_CALL_COMPLETE;
+}
+
+static inline bool rxrpc_call_has_failed(const struct rxrpc_call *call)
+{
+	return rxrpc_call_is_complete(call) && call->completion != RXRPC_CALL_SUCCEEDED;
+}
+
+/*
+ * conn_client.c
+ */
+extern unsigned int rxrpc_reap_client_connections;
+extern unsigned long rxrpc_conn_idle_client_expiry;
+extern unsigned long rxrpc_conn_idle_client_fast_expiry;
+
+void rxrpc_purge_client_connections(struct rxrpc_local *local);
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *, enum rxrpc_bundle_trace);
+void rxrpc_put_bundle(struct rxrpc_bundle *, enum rxrpc_bundle_trace);
+int rxrpc_look_up_bundle(struct rxrpc_call *call, gfp_t gfp);
+void rxrpc_connect_client_calls(struct rxrpc_local *local);
+void rxrpc_expose_client_call(struct rxrpc_call *);
+void rxrpc_disconnect_client_call(struct rxrpc_bundle *, struct rxrpc_call *);
+void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle);
+void rxrpc_discard_expired_client_conns(struct rxrpc_local *local);
+void rxrpc_clean_up_local_conns(struct rxrpc_local *);
+
+/*
+ * conn_event.c
+ */
+void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn, struct sk_buff *skb,
+				unsigned int channel);
+int rxrpc_abort_conn(struct rxrpc_connection *conn, struct sk_buff *skb,
+		     s32 abort_code, int err, enum rxrpc_abort_reason why);
+void rxrpc_process_connection(struct work_struct *);
+void rxrpc_process_delayed_final_acks(struct rxrpc_connection *, bool);
+bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb);
+void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb);
+
+static inline bool rxrpc_is_conn_aborted(const struct rxrpc_connection *conn)
+{
+	/* Order reading the abort info after the state check. */
+	return smp_load_acquire(&conn->state) == RXRPC_CONN_ABORTED;
+}
+
+/*
+ * conn_object.c
+ */
+extern unsigned int rxrpc_connection_expiry;
+extern unsigned int rxrpc_closed_conn_expiry;
+
+void rxrpc_poke_conn(struct rxrpc_connection *conn, enum rxrpc_conn_trace why);
+struct rxrpc_connection *rxrpc_alloc_connection(struct rxrpc_net *, gfp_t);
+struct rxrpc_connection *rxrpc_find_client_connection_rcu(struct rxrpc_local *,
+							  struct sockaddr_rxrpc *,
+							  struct sk_buff *);
+void __rxrpc_disconnect_call(struct rxrpc_connection *, struct rxrpc_call *);
+void rxrpc_disconnect_call(struct rxrpc_call *);
+void rxrpc_kill_client_conn(struct rxrpc_connection *);
+void rxrpc_queue_conn(struct rxrpc_connection *, enum rxrpc_conn_trace);
+void rxrpc_see_connection(struct rxrpc_connection *, enum rxrpc_conn_trace);
+struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *,
+					      enum rxrpc_conn_trace);
+struct rxrpc_connection *rxrpc_get_connection_maybe(struct rxrpc_connection *,
+						    enum rxrpc_conn_trace);
+void rxrpc_put_connection(struct rxrpc_connection *, enum rxrpc_conn_trace);
+void rxrpc_service_connection_reaper(struct work_struct *);
+void rxrpc_destroy_all_connections(struct rxrpc_net *);
+
+static inline bool rxrpc_conn_is_client(const struct rxrpc_connection *conn)
+{
+	return conn->out_clientflag;
+}
+
+static inline bool rxrpc_conn_is_service(const struct rxrpc_connection *conn)
+{
+	return !rxrpc_conn_is_client(conn);
+}
+
+static inline void rxrpc_reduce_conn_timer(struct rxrpc_connection *conn,
+					   unsigned long expire_at)
+{
+	timer_reduce(&conn->timer, expire_at);
+}
+
+/*
+ * conn_service.c
+ */
+struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
+						     struct sk_buff *);
+struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *, gfp_t);
+void rxrpc_new_incoming_connection(struct rxrpc_sock *, struct rxrpc_connection *,
+				   const struct rxrpc_security *, struct sk_buff *);
+void rxrpc_unpublish_service_conn(struct rxrpc_connection *);
+
+/*
+ * input.c
+ */
+void rxrpc_congestion_degrade(struct rxrpc_call *);
+void rxrpc_input_call_packet(struct rxrpc_call *, struct sk_buff *);
+void rxrpc_implicit_end_call(struct rxrpc_call *, struct sk_buff *);
+
+/*
+ * input_rack.c
+ */
+void rxrpc_input_rack_one(struct rxrpc_call *call,
+			  struct rxrpc_ack_summary *summary,
+			  struct rxrpc_txqueue *tq,
+			  unsigned int ix);
+void rxrpc_input_rack(struct rxrpc_call *call,
+		      struct rxrpc_ack_summary *summary,
+		      struct rxrpc_txqueue *tq,
+		      unsigned long new_acks);
+void rxrpc_rack_detect_loss_and_arm_timer(struct rxrpc_call *call,
+					  struct rxrpc_ack_summary *summary);
+ktime_t rxrpc_tlp_calc_pto(struct rxrpc_call *call, ktime_t now);
+void rxrpc_tlp_send_probe(struct rxrpc_call *call);
+void rxrpc_tlp_process_ack(struct rxrpc_call *call, struct rxrpc_ack_summary *summary);
+void rxrpc_rack_timer_expired(struct rxrpc_call *call, ktime_t overran_by);
+
+/* Initialise TLP state [RFC8958 7.1]. */
+static inline void rxrpc_tlp_init(struct rxrpc_call *call)
+{
+	call->tlp_serial = 0;
+	call->tlp_seq = call->acks_hard_ack;
+	call->tlp_is_retrans = false;
+}
+
+/*
+ * io_thread.c
+ */
+int rxrpc_encap_rcv(struct sock *, struct sk_buff *);
+void rxrpc_error_report(struct sock *);
+bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			s32 abort_code, int err);
+bool rxrpc_direct_conn_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			     s32 abort_code, int err);
+int rxrpc_io_thread(void *data);
+void rxrpc_post_response(struct rxrpc_connection *conn, struct sk_buff *skb);
+static inline void rxrpc_wake_up_io_thread(struct rxrpc_local *local)
+{
+	struct task_struct *io_thread = READ_ONCE(local->io_thread);
+
+	if (!io_thread)
+		return;
+	wake_up_process(io_thread);
+}
+
+static inline bool rxrpc_protocol_error(struct sk_buff *skb, enum rxrpc_abort_reason why)
+{
+	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EPROTO);
+}
+
+/*
+ * insecure.c
+ */
+extern const struct rxrpc_security rxrpc_no_security;
+
+/*
+ * key.c
+ */
+extern struct key_type key_type_rxrpc;
+
+int rxrpc_request_key(struct rxrpc_sock *, sockptr_t , int);
+int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *, time64_t,
+			      u32);
+
+/*
+ * local_event.c
+ */
+void rxrpc_gen_version_string(void);
+void rxrpc_send_version_request(struct rxrpc_local *local,
+				struct rxrpc_host_header *hdr,
+				struct sk_buff *skb);
+
+/*
+ * local_object.c
+ */
+void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set);
+struct rxrpc_local *rxrpc_lookup_local(struct net *, const struct sockaddr_rxrpc *);
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *, enum rxrpc_local_trace);
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *, enum rxrpc_local_trace);
+void rxrpc_put_local(struct rxrpc_local *, enum rxrpc_local_trace);
+struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *, enum rxrpc_local_trace);
+void rxrpc_unuse_local(struct rxrpc_local *, enum rxrpc_local_trace);
+void rxrpc_destroy_local(struct rxrpc_local *local);
+void rxrpc_destroy_all_locals(struct rxrpc_net *);
+
+static inline bool __rxrpc_use_local(struct rxrpc_local *local,
+				     enum rxrpc_local_trace why)
+{
+	int r, u;
+
+	r = refcount_read(&local->ref);
+	u = atomic_fetch_add_unless(&local->active_users, 1, 0);
+	trace_rxrpc_local(local->debug_id, why, r, u);
+	return u != 0;
+}
+
+static inline void rxrpc_see_local(struct rxrpc_local *local,
+				   enum rxrpc_local_trace why)
+{
+	int r, u;
+
+	r = refcount_read(&local->ref);
+	u = atomic_read(&local->active_users);
+	trace_rxrpc_local(local->debug_id, why, r, u);
+}
+
+/*
+ * misc.c
+ */
+extern unsigned int rxrpc_max_backlog __read_mostly;
+extern unsigned long rxrpc_soft_ack_delay;
+extern unsigned long rxrpc_idle_ack_delay;
+extern unsigned int rxrpc_rx_window_size;
+extern unsigned int rxrpc_rx_mtu;
+extern unsigned int rxrpc_rx_jumbo_max;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+extern unsigned long rxrpc_inject_rx_delay;
+#endif
+
+/*
+ * net_ns.c
+ */
+extern unsigned int rxrpc_net_id;
+extern struct pernet_operations rxrpc_net_ops;
+
+static inline struct rxrpc_net *rxrpc_net(struct net *net)
+{
+	return net_generic(net, rxrpc_net_id);
+}
+
+/*
+ * oob.c
+ */
+bool rxrpc_notify_socket_oob(struct rxrpc_call *call, struct sk_buff *skb);
+void rxrpc_add_pending_oob(struct rxrpc_sock *rx, struct sk_buff *skb);
+int rxrpc_sendmsg_oob(struct rxrpc_sock *rx, struct msghdr *msg, size_t len);
+
+/*
+ * output.c
+ */
+ssize_t do_udp_sendmsg(struct socket *socket, struct msghdr *msg, size_t len);
+void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason,
+		    rxrpc_serial_t serial, enum rxrpc_propose_ack_trace why);
+void rxrpc_send_probe_for_pmtud(struct rxrpc_call *call);
+int rxrpc_send_abort_packet(struct rxrpc_call *);
+void rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_send_data_req *req);
+void rxrpc_send_conn_abort(struct rxrpc_connection *conn);
+void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb);
+void rxrpc_send_keepalive(struct rxrpc_peer *);
+void rxrpc_send_response(struct rxrpc_connection *conn, struct sk_buff *skb);
+
+/*
+ * peer_event.c
+ */
+void rxrpc_input_error(struct rxrpc_local *, struct sk_buff *);
+void rxrpc_peer_keepalive_worker(struct work_struct *);
+void rxrpc_input_probe_for_pmtud(struct rxrpc_connection *conn, rxrpc_serial_t acked_serial,
+				 bool sendmsg_fail);
+
+/* Update the last transmission time on a peer for keepalive purposes. */
+static inline void rxrpc_peer_mark_tx(struct rxrpc_peer *peer)
+{
+	/* To avoid tearing on 32-bit systems, we only keep the LSW. */
+	WRITE_ONCE(peer->last_tx_at, ktime_get_seconds());
+}
+
+/*
+ * peer_object.c
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *,
+					 const struct sockaddr_rxrpc *);
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
+				     struct sockaddr_rxrpc *srx, gfp_t gfp);
+void rxrpc_assess_MTU_size(struct rxrpc_local *local, struct rxrpc_peer *peer);
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t,
+				    enum rxrpc_peer_trace);
+void rxrpc_new_incoming_peer(struct rxrpc_local *local, struct rxrpc_peer *peer);
+void rxrpc_destroy_all_peers(struct rxrpc_net *);
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *, enum rxrpc_peer_trace);
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *, enum rxrpc_peer_trace);
+void rxrpc_put_peer(struct rxrpc_peer *, enum rxrpc_peer_trace);
+
+/*
+ * proc.c
+ */
+extern const struct seq_operations rxrpc_call_seq_ops;
+extern const struct seq_operations rxrpc_connection_seq_ops;
+extern const struct seq_operations rxrpc_bundle_seq_ops;
+extern const struct seq_operations rxrpc_peer_seq_ops;
+extern const struct seq_operations rxrpc_local_seq_ops;
+
+/*
+ * recvmsg.c
+ */
+void rxrpc_notify_socket(struct rxrpc_call *);
+int rxrpc_recvmsg(struct socket *, struct msghdr *, size_t, int);
+
+/*
+ * Abort a call due to a protocol error.
+ */
+static inline int rxrpc_abort_eproto(struct rxrpc_call *call,
+				     struct sk_buff *skb,
+				     s32 abort_code,
+				     enum rxrpc_abort_reason why)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	rxrpc_abort_call(call, sp->hdr.seq, abort_code, -EPROTO, why);
+	return -EPROTO;
+}
+
+/*
+ * rtt.c
+ */
+void rxrpc_call_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
+			int rtt_slot,
+			rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial,
+			ktime_t send_time, ktime_t resp_time);
+ktime_t rxrpc_get_rto_backoff(struct rxrpc_call *call, bool retrans);
+void rxrpc_call_init_rtt(struct rxrpc_call *call);
+
+/*
+ * rxgk.c
+ */
+extern const struct rxrpc_security rxgk_yfs;
+
+/*
+ * rxkad.c
+ */
+#ifdef CONFIG_RXKAD
+extern const struct rxrpc_security rxkad;
+#endif
+
+/*
+ * security.c
+ */
+int __init rxrpc_init_security(void);
+const struct rxrpc_security *rxrpc_security_lookup(u8);
+void rxrpc_exit_security(void);
+int rxrpc_init_client_call_security(struct rxrpc_call *);
+int rxrpc_init_client_conn_security(struct rxrpc_connection *);
+const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *,
+							 struct sk_buff *);
+struct key *rxrpc_look_up_server_security(struct rxrpc_connection *,
+					  struct sk_buff *, u32, u32);
+
+/*
+ * sendmsg.c
+ */
+bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
+			 enum rxrpc_abort_reason why);
+int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);
+
+/*
+ * server_key.c
+ */
+extern struct key_type key_type_rxrpc_s;
+
+int rxrpc_server_keyring(struct rxrpc_sock *, sockptr_t, int);
+
+/*
+ * skbuff.c
+ */
+void rxrpc_kernel_data_consumed(struct rxrpc_call *, struct sk_buff *);
+void rxrpc_new_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_see_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_get_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_free_skb(struct sk_buff *, enum rxrpc_skb_trace);
+void rxrpc_purge_queue(struct sk_buff_head *);
+
+/*
+ * stats.c
+ */
+int rxrpc_stats_show(struct seq_file *seq, void *v);
+int rxrpc_stats_clear(struct file *file, char *buf, size_t size);
+
+#define rxrpc_inc_stat(rxnet, s) atomic_inc(&(rxnet)->s)
+#define rxrpc_dec_stat(rxnet, s) atomic_dec(&(rxnet)->s)
+
+/*
+ * sysctl.c
+ */
+#ifdef CONFIG_SYSCTL
+extern int __init rxrpc_sysctl_init(void);
+extern void rxrpc_sysctl_exit(void);
+#else
+static inline int __init rxrpc_sysctl_init(void) { return 0; }
+static inline void rxrpc_sysctl_exit(void) {}
+#endif
+
+/*
+ * txbuf.c
+ */
+extern atomic_t rxrpc_nr_txbuf;
+struct rxrpc_txbuf *rxrpc_alloc_data_txbuf(struct rxrpc_call *call, size_t data_size,
+					   size_t data_align, gfp_t gfp);
+void rxrpc_see_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what);
+void rxrpc_put_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what);
+
+/*
+ * utils.c
+ */
+int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *, struct sk_buff *);
+
+static inline bool before(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) < 0;
+}
+static inline bool before_eq(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) <= 0;
+}
+static inline bool after(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) > 0;
+}
+static inline bool after_eq(u32 seq1, u32 seq2)
+{
+        return (s32)(seq1 - seq2) >= 0;
+}
+
+static inline u32 earliest(u32 seq1, u32 seq2)
+{
+	return before(seq1, seq2) ? seq1 : seq2;
+}
+
+static inline u32 latest(u32 seq1, u32 seq2)
+{
+	return after(seq1, seq2) ? seq1 : seq2;
+}
+
+static inline bool rxrpc_seq_in_txq(const struct rxrpc_txqueue *tq, rxrpc_seq_t seq)
+{
+	return (seq & (RXRPC_NR_TXQUEUE - 1)) == tq->qbase;
+}
+
+static inline void rxrpc_queue_rx_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	rxrpc_get_skb(skb, rxrpc_skb_get_call_rx);
+	__skb_queue_tail(&call->rx_queue, skb);
+	rxrpc_poke_call(call, rxrpc_call_poke_rx_packet);
+}
+
+/*
+ * Calculate how much space there is for transmitting more DATA packets.
+ */
+static inline unsigned int rxrpc_tx_window_space(const struct rxrpc_call *call)
+{
+	int winsize = umin(call->tx_winsize, call->cong_cwnd + call->cong_extra);
+	int transmitted = call->tx_top - call->tx_bottom;
+
+	return max(winsize - transmitted, 0);
+}
+
+static inline unsigned int rxrpc_left_out(const struct rxrpc_call *call)
+{
+	return call->acks_nr_sacks + call->tx_nr_lost;
+}
+
+/*
+ * Calculate the number of transmitted DATA packets assumed to be in flight
+ * [approx RFC6675].
+ */
+static inline unsigned int rxrpc_tx_in_flight(const struct rxrpc_call *call)
+{
+	return call->tx_nr_sent - rxrpc_left_out(call) + call->tx_nr_resent;
+}
+
+/*
+ * debug tracing
+ */
+extern unsigned int rxrpc_debug;
+
+#define dbgprintk(FMT,...) \
+	printk("[%-6.6s] "FMT"\n", current->comm ,##__VA_ARGS__)
+
+#define kenter(FMT,...)	dbgprintk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
+#define kleave(FMT,...)	dbgprintk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
+#define kdebug(FMT,...)	dbgprintk("    "FMT ,##__VA_ARGS__)
+
+
+#if defined(__KDEBUG)
+#define _enter(FMT,...)	kenter(FMT,##__VA_ARGS__)
+#define _leave(FMT,...)	kleave(FMT,##__VA_ARGS__)
+#define _debug(FMT,...)	kdebug(FMT,##__VA_ARGS__)
+
+#elif defined(CONFIG_AF_RXRPC_DEBUG)
+#define RXRPC_DEBUG_KENTER	0x01
+#define RXRPC_DEBUG_KLEAVE	0x02
+#define RXRPC_DEBUG_KDEBUG	0x04
+
+#define _enter(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KENTER))	\
+		kenter(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _leave(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KLEAVE))	\
+		kleave(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#define _debug(FMT,...)					\
+do {							\
+	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KDEBUG))	\
+		kdebug(FMT,##__VA_ARGS__);		\
+} while (0)
+
+#else
+#define _enter(FMT,...)	no_printk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
+#define _leave(FMT,...)	no_printk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
+#define _debug(FMT,...)	no_printk("    "FMT ,##__VA_ARGS__)
+#endif
+
+/*
+ * debug assertion checking
+ */
+#if 1 // defined(__KDEBUGALL)
+
+#define ASSERT(X)						\
+do {								\
+	if (unlikely(!(X))) {					\
+		pr_err("Assertion failed\n");			\
+		BUG();						\
+	}							\
+} while (0)
+
+#define ASSERTCMP(X, OP, Y)						\
+do {									\
+	__typeof__(X) _x = (X);						\
+	__typeof__(Y) _y = (__typeof__(X))(Y);				\
+	if (unlikely(!(_x OP _y))) {					\
+		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false\n", \
+		       (unsigned long)_x, (unsigned long)_x, #OP,	\
+		       (unsigned long)_y, (unsigned long)_y);		\
+		BUG();							\
+	}								\
+} while (0)
+
+#define ASSERTIF(C, X)						\
+do {								\
+	if (unlikely((C) && !(X))) {				\
+		pr_err("Assertion failed\n");			\
+		BUG();						\
+	}							\
+} while (0)
+
+#define ASSERTIFCMP(C, X, OP, Y)					\
+do {									\
+	__typeof__(X) _x = (X);						\
+	__typeof__(Y) _y = (__typeof__(X))(Y);				\
+	if (unlikely((C) && !(_x OP _y))) {				\
+		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false\n", \
+		       (unsigned long)_x, (unsigned long)_x, #OP,	\
+		       (unsigned long)_y, (unsigned long)_y);		\
+		BUG();							\
+	}								\
+} while (0)
+
+#else
+
+#define ASSERT(X)				\
+do {						\
+} while (0)
+
+#define ASSERTCMP(X, OP, Y)			\
+do {						\
+} while (0)
+
+#define ASSERTIF(C, X)				\
+do {						\
+} while (0)
+
+#define ASSERTIFCMP(C, X, OP, Y)		\
+do {						\
+} while (0)
+
+#endif /* __KDEBUGALL */
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
new file mode 100644
index 000000000..47824120f
--- /dev/null
+++ b/net/rxrpc/call_accept.c
@@ -0,0 +1,496 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* incoming call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <linux/gfp.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+static void rxrpc_dummy_notify(struct sock *sk, struct rxrpc_call *call,
+			       unsigned long user_call_ID)
+{
+}
+
+/*
+ * Preallocate a single service call, connection and peer and, if possible,
+ * give them a user ID and attach the user's side of the ID to them.
+ */
+static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
+				      struct rxrpc_backlog *b,
+				      rxrpc_notify_rx_t notify_rx,
+				      unsigned long user_call_ID, gfp_t gfp,
+				      unsigned int debug_id)
+{
+	struct rxrpc_call *call, *xcall;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	struct rb_node *parent, **pp;
+	int max, tmp;
+	unsigned int size = RXRPC_BACKLOG_MAX;
+	unsigned int head, tail, call_head, call_tail;
+
+	max = rx->sk.sk_max_ack_backlog;
+	tmp = rx->sk.sk_ack_backlog;
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [full %u]", max);
+		return -ENOBUFS;
+	}
+	max -= tmp;
+
+	/* We don't need more conns and peers than we have calls, but on the
+	 * other hand, we shouldn't ever use more peers than conns or conns
+	 * than calls.
+	 */
+	call_head = b->call_backlog_head;
+	call_tail = READ_ONCE(b->call_backlog_tail);
+	tmp = CIRC_CNT(call_head, call_tail, size);
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [enough %u]", tmp);
+		return -ENOBUFS;
+	}
+	max = tmp + 1;
+
+	head = b->peer_backlog_head;
+	tail = READ_ONCE(b->peer_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_peer *peer;
+
+		peer = rxrpc_alloc_peer(rx->local, gfp, rxrpc_peer_new_prealloc);
+		if (!peer)
+			return -ENOMEM;
+		b->peer_backlog[head] = peer;
+		smp_store_release(&b->peer_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	head = b->conn_backlog_head;
+	tail = READ_ONCE(b->conn_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_connection *conn;
+
+		conn = rxrpc_prealloc_service_connection(rxnet, gfp);
+		if (!conn)
+			return -ENOMEM;
+		b->conn_backlog[head] = conn;
+		smp_store_release(&b->conn_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	/* Now it gets complicated, because calls get registered with the
+	 * socket here, with a user ID preassigned by the user.
+	 */
+	call = rxrpc_alloc_call(rx, gfp, debug_id);
+	if (!call)
+		return -ENOMEM;
+	call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
+	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_PREALLOC);
+	__set_bit(RXRPC_CALL_EV_INITIAL_PING, &call->events);
+
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
+			 user_call_ID, rxrpc_call_new_prealloc_service);
+
+	write_lock(&rx->call_lock);
+
+	/* Check the user ID isn't already in use */
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+		if (user_call_ID < xcall->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (user_call_ID > xcall->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto id_in_use;
+	}
+
+	call->user_call_ID = user_call_ID;
+	call->notify_rx = notify_rx;
+	if (rx->app_ops &&
+	    rx->app_ops->user_attach_call) {
+		rxrpc_get_call(call, rxrpc_call_get_kernel_service);
+		rx->app_ops->user_attach_call(call, user_call_ID);
+	}
+
+	rxrpc_get_call(call, rxrpc_call_get_userid);
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+
+	list_add(&call->sock_link, &rx->sock_calls);
+
+	write_unlock(&rx->call_lock);
+
+	rxnet = call->rxnet;
+	spin_lock(&rxnet->call_lock);
+	list_add_tail_rcu(&call->link, &rxnet->calls);
+	spin_unlock(&rxnet->call_lock);
+
+	b->call_backlog[call_head] = call;
+	smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
+	_leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
+	return 0;
+
+id_in_use:
+	write_unlock(&rx->call_lock);
+	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EBADSLT);
+	rxrpc_cleanup_call(call);
+	_leave(" = -EBADSLT");
+	return -EBADSLT;
+}
+
+/*
+ * Allocate the preallocation buffers for incoming service calls.  These must
+ * be charged manually.
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (!b) {
+		b = kzalloc_obj(struct rxrpc_backlog, gfp);
+		if (!b)
+			return -ENOMEM;
+		rx->backlog = b;
+	}
+
+	return 0;
+}
+
+/*
+ * Discard the preallocation on a service.
+ */
+void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+	unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
+
+	if (!b)
+		return;
+	rx->backlog = NULL;
+
+	/* Make sure that there aren't any incoming calls in progress before we
+	 * clear the preallocation buffers.
+	 */
+	spin_lock_irq(&rx->incoming_lock);
+	spin_unlock_irq(&rx->incoming_lock);
+
+	head = b->peer_backlog_head;
+	tail = b->peer_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_peer *peer = b->peer_backlog[tail];
+		rxrpc_put_local(peer->local, rxrpc_local_put_prealloc_peer);
+		kfree(peer);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->conn_backlog_head;
+	tail = b->conn_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_connection *conn = b->conn_backlog[tail];
+		write_lock(&rxnet->conn_lock);
+		list_del(&conn->link);
+		list_del(&conn->proc_link);
+		write_unlock(&rxnet->conn_lock);
+		kfree(conn);
+		if (atomic_dec_and_test(&rxnet->nr_conns))
+			wake_up_var(&rxnet->nr_conns);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->call_backlog_head;
+	tail = b->call_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_call *call = b->call_backlog[tail];
+		rxrpc_see_call(call, rxrpc_call_see_discard);
+		rcu_assign_pointer(call->socket, rx);
+		if (rx->app_ops &&
+		    rx->app_ops->discard_new_call) {
+			_debug("discard %lx", call->user_call_ID);
+			rx->app_ops->discard_new_call(call, call->user_call_ID);
+			if (call->notify_rx)
+				call->notify_rx = rxrpc_dummy_notify;
+			rxrpc_put_call(call, rxrpc_call_put_kernel);
+		}
+		rxrpc_call_completed(call);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put_discard_prealloc);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	kfree(b);
+}
+
+/*
+ * Allocate a new incoming call from the prealloc pool, along with a connection
+ * and a peer as necessary.
+ */
+static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
+						    struct rxrpc_local *local,
+						    struct rxrpc_peer *peer,
+						    struct rxrpc_connection *conn,
+						    const struct rxrpc_security *sec,
+						    struct sockaddr_rxrpc *peer_srx,
+						    struct sk_buff *skb)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	struct rxrpc_call *call;
+	unsigned short call_head, conn_head, peer_head;
+	unsigned short call_tail, conn_tail, peer_tail;
+	unsigned short call_count, conn_count;
+
+	if (!b)
+		return NULL;
+
+	/* #calls >= #conns >= #peers must hold true. */
+	call_head = smp_load_acquire(&b->call_backlog_head);
+	call_tail = b->call_backlog_tail;
+	call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
+	conn_head = smp_load_acquire(&b->conn_backlog_head);
+	conn_tail = b->conn_backlog_tail;
+	conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
+	ASSERTCMP(conn_count, >=, call_count);
+	peer_head = smp_load_acquire(&b->peer_backlog_head);
+	peer_tail = b->peer_backlog_tail;
+	ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
+		  conn_count);
+
+	if (call_count == 0)
+		return NULL;
+
+	if (!conn) {
+		if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_service_conn))
+			peer = NULL;
+		if (!peer) {
+			peer = b->peer_backlog[peer_tail];
+			peer->srx = *peer_srx;
+			b->peer_backlog[peer_tail] = NULL;
+			smp_store_release(&b->peer_backlog_tail,
+					  (peer_tail + 1) &
+					  (RXRPC_BACKLOG_MAX - 1));
+
+			rxrpc_new_incoming_peer(local, peer);
+		}
+
+		/* Now allocate and set up the connection */
+		conn = b->conn_backlog[conn_tail];
+		b->conn_backlog[conn_tail] = NULL;
+		smp_store_release(&b->conn_backlog_tail,
+				  (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+		conn->local = rxrpc_get_local(local, rxrpc_local_get_prealloc_conn);
+		conn->peer = peer;
+		rxrpc_see_connection(conn, rxrpc_conn_see_new_service_conn);
+		rxrpc_new_incoming_connection(rx, conn, sec, skb);
+	} else {
+		rxrpc_get_connection(conn, rxrpc_conn_get_service_conn);
+		atomic_inc(&conn->active);
+	}
+
+	/* And now we can allocate and set up a new call */
+	call = b->call_backlog[call_tail];
+	b->call_backlog[call_tail] = NULL;
+	smp_store_release(&b->call_backlog_tail,
+			  (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
+
+	rxrpc_see_call(call, rxrpc_call_see_accept);
+	call->local = rxrpc_get_local(conn->local, rxrpc_local_get_call);
+	call->conn = conn;
+	call->security = conn->security;
+	call->security_ix = conn->security_ix;
+	call->peer = rxrpc_get_peer(conn->peer, rxrpc_peer_get_accept);
+	call->dest_srx = peer->srx;
+	call->cong_ssthresh = call->peer->cong_ssthresh;
+	call->tx_last_sent = ktime_get_real();
+	return call;
+}
+
+/*
+ * Set up a new incoming call.  Called from the I/O thread.
+ *
+ * If this is for a kernel service, when we allocate the call, it will have
+ * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
+ * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
+ * services only have the ref from the backlog buffer.
+ *
+ * If we want to report an error, we mark the skb with the packet type and
+ * abort code and return false.
+ */
+bool rxrpc_new_incoming_call(struct rxrpc_local *local,
+			     struct rxrpc_peer *peer,
+			     struct rxrpc_connection *conn,
+			     struct sockaddr_rxrpc *peer_srx,
+			     struct sk_buff *skb)
+{
+	const struct rxrpc_security *sec = NULL;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_call *call = NULL;
+	struct rxrpc_sock *rx;
+
+	_enter("");
+
+	/* Don't set up a call for anything other than a DATA packet. */
+	if (sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
+		return rxrpc_protocol_error(skb, rxrpc_eproto_no_service_call);
+
+	read_lock_irq(&local->services_lock);
+
+	/* Weed out packets to services we're not offering.  Packets that would
+	 * begin a call are explicitly rejected and the rest are just
+	 * discarded.
+	 */
+	rx = local->service;
+	if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
+		    sp->hdr.serviceId != rx->second_service)
+	    ) {
+		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+		    sp->hdr.seq == 1)
+			goto unsupported_service;
+		goto discard;
+	}
+
+	if (!conn) {
+		sec = rxrpc_get_incoming_security(rx, skb);
+		if (!sec)
+			goto unsupported_security;
+	}
+
+	spin_lock(&rx->incoming_lock);
+	if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
+	    rx->sk.sk_state == RXRPC_CLOSE) {
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_shut_down,
+					RX_INVALID_OPERATION, -ESHUTDOWN);
+		goto no_call;
+	}
+
+	call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, peer_srx,
+					 skb);
+	if (!call) {
+		skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
+		goto no_call;
+	}
+
+	trace_rxrpc_receive(call, rxrpc_receive_incoming,
+			    sp->hdr.serial, sp->hdr.seq);
+
+	/* Make the call live. */
+	rxrpc_incoming_call(rx, call, skb);
+	conn = call->conn;
+
+	if (rx->app_ops &&
+	    rx->app_ops->notify_new_call)
+		rx->app_ops->notify_new_call(&rx->sk, call, call->user_call_ID);
+
+	spin_lock(&conn->state_lock);
+	if (conn->state == RXRPC_CONN_SERVICE_UNSECURED) {
+		conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
+		set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
+		rxrpc_queue_conn(call->conn, rxrpc_conn_queue_challenge);
+	}
+	spin_unlock(&conn->state_lock);
+
+	spin_unlock(&rx->incoming_lock);
+	read_unlock_irq(&local->services_lock);
+	rxrpc_assess_MTU_size(local, call->peer);
+
+	if (hlist_unhashed(&call->error_link)) {
+		spin_lock_irq(&call->peer->lock);
+		hlist_add_head(&call->error_link, &call->peer->error_targets);
+		spin_unlock_irq(&call->peer->lock);
+	}
+
+	_leave(" = %p{%d}", call, call->debug_id);
+	rxrpc_queue_rx_call_packet(call, skb);
+	rxrpc_put_call(call, rxrpc_call_put_input);
+	return true;
+
+unsupported_service:
+	read_unlock_irq(&local->services_lock);
+	return rxrpc_direct_conn_abort(skb, rxrpc_abort_service_not_offered,
+				       RX_INVALID_OPERATION, -EOPNOTSUPP);
+unsupported_security:
+	read_unlock_irq(&local->services_lock);
+	return rxrpc_direct_conn_abort(skb, rxrpc_abort_service_not_offered,
+				       RX_INVALID_OPERATION, -EKEYREJECTED);
+no_call:
+	spin_unlock(&rx->incoming_lock);
+	read_unlock_irq(&local->services_lock);
+	_leave(" = f [%u]", skb->mark);
+	return false;
+discard:
+	read_unlock_irq(&local->services_lock);
+	return true;
+}
+
+/*
+ * Charge up socket with preallocated calls, attaching user call IDs.
+ */
+int rxrpc_user_charge_accept(struct rxrpc_sock *rx, unsigned long user_call_ID)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (rx->sk.sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, NULL, user_call_ID, GFP_KERNEL,
+					  atomic_inc_return(&rxrpc_debug_id));
+}
+
+/*
+ * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
+ * @sock: The socket on which to preallocate
+ * @notify_rx: Event notification function for the call
+ * @user_call_ID: The tag to attach to the preallocated call
+ * @gfp: The allocation conditions.
+ * @debug_id: The tracing debug ID.
+ *
+ * Charge up the socket with preallocated calls, each with a user ID.  The
+ * ->user_attach_call() callback function should be provided to effect the
+ * attachment from the user's side.  The user is given a ref to hold on the
+ * call.
+ *
+ * Note that the call may be come connected before this function returns.
+ */
+int rxrpc_kernel_charge_accept(struct socket *sock, rxrpc_notify_rx_t notify_rx,
+			       unsigned long user_call_ID, gfp_t gfp,
+			       unsigned int debug_id)
+{
+	struct rxrpc_backlog *b;
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+	int ret;
+
+	sk = sock->sk;
+	rx = rxrpc_sk(sk);
+
+	lock_sock(sk);
+	if (sk->sk_state != RXRPC_SERVER_LISTENING || !rx->backlog) {
+		ret = -ESHUTDOWN;
+		goto out;
+	}
+
+	b = rx->backlog;
+	ret = rxrpc_service_prealloc_one(rx, b, notify_rx, user_call_ID,
+					 gfp, debug_id);
+
+out:
+	release_sock(sk);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_charge_accept);
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
new file mode 100644
index 000000000..21be9c86d
--- /dev/null
+++ b/net/rxrpc/call_event.c
@@ -0,0 +1,500 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Propose a PING ACK be sent.
+ */
+void rxrpc_propose_ping(struct rxrpc_call *call, u32 serial,
+			enum rxrpc_propose_ack_trace why)
+{
+	ktime_t delay = ms_to_ktime(READ_ONCE(rxrpc_idle_ack_delay));
+	ktime_t now = ktime_get_real();
+	ktime_t ping_at = ktime_add(now, delay);
+
+	trace_rxrpc_propose_ack(call, why, RXRPC_ACK_PING, serial);
+	if (ktime_before(ping_at, call->ping_at)) {
+		call->ping_at = ping_at;
+		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_ping);
+	}
+}
+
+/*
+ * Propose a DELAY ACK be sent in the future.
+ */
+void rxrpc_propose_delay_ACK(struct rxrpc_call *call, rxrpc_serial_t serial,
+			     enum rxrpc_propose_ack_trace why)
+{
+	ktime_t now = ktime_get_real(), delay;
+
+	trace_rxrpc_propose_ack(call, why, RXRPC_ACK_DELAY, serial);
+
+	if (call->srtt_us)
+		delay = (call->srtt_us >> 3) * NSEC_PER_USEC;
+	else
+		delay = ms_to_ktime(READ_ONCE(rxrpc_soft_ack_delay));
+	ktime_add_ms(delay, call->tx_backoff);
+
+	call->delay_ack_at = ktime_add(now, delay);
+	trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_delayed_ack);
+}
+
+/*
+ * Retransmit one or more packets.
+ */
+static bool rxrpc_retransmit_data(struct rxrpc_call *call,
+				  struct rxrpc_send_data_req *req)
+{
+	struct rxrpc_txqueue *tq = req->tq;
+	unsigned int ix = req->seq & RXRPC_TXQ_MASK;
+	struct rxrpc_txbuf *txb = tq->bufs[ix];
+
+	_enter("%x,%x,%x,%x", tq->qbase, req->seq, ix, txb->debug_id);
+
+	req->retrans = true;
+	trace_rxrpc_retransmit(call, req, txb);
+
+	txb->flags |= RXRPC_TXBUF_RESENT;
+	rxrpc_send_data_packet(call, req);
+	rxrpc_inc_stat(call->rxnet, stat_tx_data_retrans);
+
+	req->tq		= NULL;
+	req->n		= 0;
+	req->did_send	= true;
+	req->now	= ktime_get_real();
+	return true;
+}
+
+/*
+ * Perform retransmission of NAK'd and unack'd packets.
+ */
+static void rxrpc_resend(struct rxrpc_call *call)
+{
+	struct rxrpc_send_data_req req = {
+		.now	= ktime_get_real(),
+		.trace	= rxrpc_txdata_retransmit,
+	};
+	struct rxrpc_txqueue *tq;
+
+	_enter("{%d,%d}", call->tx_bottom, call->tx_top);
+
+	trace_rxrpc_resend(call, call->acks_highest_serial);
+
+	/* Scan the transmission queue, looking for lost packets. */
+	for (tq = call->tx_queue; tq; tq = tq->next) {
+		unsigned long lost = tq->segment_lost;
+
+		if (after(tq->qbase, call->tx_transmitted))
+			break;
+
+		_debug("retr %16lx %u c=%08x [%x]",
+		       tq->segment_acked, tq->nr_reported_acks, call->debug_id, tq->qbase);
+		_debug("lost %16lx", lost);
+
+		trace_rxrpc_resend_lost(call, tq, lost);
+		while (lost) {
+			unsigned int ix = __ffs(lost);
+			struct rxrpc_txbuf *txb = tq->bufs[ix];
+
+			__clear_bit(ix, &lost);
+			rxrpc_see_txbuf(txb, rxrpc_txbuf_see_lost);
+
+			req.tq  = tq;
+			req.seq = tq->qbase + ix;
+			req.n   = 1;
+			rxrpc_retransmit_data(call, &req);
+		}
+	}
+
+	rxrpc_get_rto_backoff(call, req.did_send);
+	_leave("");
+}
+
+/*
+ * Resend the highest-seq DATA packet so far transmitted for RACK-TLP [RFC8985 7.3].
+ */
+void rxrpc_resend_tlp(struct rxrpc_call *call)
+{
+	struct rxrpc_send_data_req req = {
+		.now		= ktime_get_real(),
+		.seq		= call->tx_transmitted,
+		.n		= 1,
+		.tlp_probe	= true,
+		.trace		= rxrpc_txdata_tlp_retransmit,
+	};
+
+	/* There's a chance it'll be on the tail segment of the queue. */
+	req.tq = READ_ONCE(call->tx_qtail);
+	if (req.tq &&
+	    before(call->tx_transmitted, req.tq->qbase + RXRPC_NR_TXQUEUE)) {
+		rxrpc_retransmit_data(call, &req);
+		return;
+	}
+
+	for (req.tq = call->tx_queue; req.tq; req.tq = req.tq->next) {
+		if (after_eq(call->tx_transmitted, req.tq->qbase) &&
+		    before(call->tx_transmitted, req.tq->qbase + RXRPC_NR_TXQUEUE)) {
+			rxrpc_retransmit_data(call, &req);
+			return;
+		}
+	}
+}
+
+/*
+ * Start transmitting the reply to a service.  This cancels the need to ACK the
+ * request if we haven't yet done so.
+ */
+static void rxrpc_begin_service_reply(struct rxrpc_call *call)
+{
+	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_SEND_REPLY);
+	if (call->ackr_reason == RXRPC_ACK_DELAY)
+		call->ackr_reason = 0;
+	call->delay_ack_at = KTIME_MAX;
+	trace_rxrpc_timer_can(call, rxrpc_timer_trace_delayed_ack);
+}
+
+/*
+ * Close the transmission phase.  After this point there is no more data to be
+ * transmitted in the call.
+ */
+static void rxrpc_close_tx_phase(struct rxrpc_call *call)
+{
+	_debug("________awaiting reply/ACK__________");
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+		rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_ACK);
+		break;
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_AWAIT_ACK);
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * Transmit some as-yet untransmitted data, to a maximum of the supplied limit.
+ */
+static void rxrpc_transmit_fresh_data(struct rxrpc_call *call, unsigned int limit,
+				      enum rxrpc_txdata_trace trace)
+{
+	int space = rxrpc_tx_window_space(call);
+
+	if (!test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		if (call->send_top == call->tx_top)
+			return;
+		rxrpc_expose_client_call(call);
+	}
+
+	while (space > 0) {
+		struct rxrpc_send_data_req req = {
+			.now	= ktime_get_real(),
+			.seq	= call->tx_transmitted + 1,
+			.n	= 0,
+			.trace	= trace,
+		};
+		struct rxrpc_txqueue *tq;
+		struct rxrpc_txbuf *txb;
+		rxrpc_seq_t send_top, seq;
+		int limit = min(space, max(call->peer->pmtud_jumbo, 1));
+
+		/* Order send_top before the contents of the new txbufs and
+		 * txqueue pointers
+		 */
+		send_top = smp_load_acquire(&call->send_top);
+		if (call->tx_top == send_top)
+			break;
+
+		trace_rxrpc_transmit(call, send_top, space);
+
+		tq = call->tx_qtail;
+		seq = call->tx_top;
+		trace_rxrpc_tq(call, tq, seq, rxrpc_tq_decant);
+
+		do {
+			int ix;
+
+			seq++;
+			ix = seq & RXRPC_TXQ_MASK;
+			if (!ix) {
+				tq = tq->next;
+				trace_rxrpc_tq(call, tq, seq, rxrpc_tq_decant_advance);
+			}
+			if (!req.tq)
+				req.tq = tq;
+			txb = tq->bufs[ix];
+			req.n++;
+			if (!txb->jumboable)
+				break;
+		} while (req.n < limit && before(seq, send_top));
+
+		if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_PRE_SEND)
+			rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_SEND_REQUEST);
+		if (txb->flags & RXRPC_LAST_PACKET) {
+			rxrpc_close_tx_phase(call);
+			tq = NULL;
+		}
+		call->tx_qtail = tq;
+		call->tx_top = seq;
+
+		space -= req.n;
+		rxrpc_send_data_packet(call, &req);
+	}
+}
+
+void rxrpc_transmit_some_data(struct rxrpc_call *call, unsigned int limit,
+			      enum rxrpc_txdata_trace trace)
+{
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_SERVER_ACK_REQUEST:
+		if (call->tx_bottom == READ_ONCE(call->send_top))
+			return;
+		rxrpc_begin_service_reply(call);
+		fallthrough;
+
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+	case RXRPC_CALL_CLIENT_PRE_SEND:
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+		if (!rxrpc_tx_window_space(call))
+			return;
+		if (call->tx_bottom == READ_ONCE(call->send_top)) {
+			rxrpc_inc_stat(call->rxnet, stat_tx_data_underflow);
+			return;
+		}
+		rxrpc_transmit_fresh_data(call, limit, trace);
+		break;
+	default:
+		return;
+	}
+}
+
+/*
+ * Ping the other end to fill our RTT cache and to retrieve the rwind
+ * and MTU parameters.
+ */
+static void rxrpc_send_initial_ping(struct rxrpc_call *call)
+{
+	if (call->rtt_count < 3 ||
+	    ktime_before(ktime_add_ms(call->rtt_last_req, 1000),
+			 ktime_get_real()))
+		rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+			       rxrpc_propose_ack_ping_for_params);
+}
+
+/*
+ * Handle retransmission and deferred ACK/abort generation.
+ */
+bool rxrpc_input_call_event(struct rxrpc_call *call)
+{
+	struct sk_buff *skb;
+	ktime_t now, t;
+	bool did_receive = false, saw_ack = false;
+	s32 abort_code;
+
+	rxrpc_see_call(call, rxrpc_call_see_input);
+
+	//printk("\n--------------------\n");
+	_enter("{%d,%s,%lx}",
+	       call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)],
+	       call->events);
+
+	/* Handle abort request locklessly, vs rxrpc_propose_abort(). */
+	abort_code = smp_load_acquire(&call->send_abort);
+	if (abort_code) {
+		rxrpc_abort_call(call, 0, call->send_abort, call->send_abort_err,
+				 call->send_abort_why);
+		goto out;
+	}
+
+	do {
+		skb = __skb_dequeue(&call->rx_queue);
+		if (skb) {
+			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+			if (__rxrpc_call_is_complete(call) ||
+			    skb->mark == RXRPC_SKB_MARK_ERROR) {
+				rxrpc_free_skb(skb, rxrpc_skb_put_call_rx);
+				goto out;
+			}
+
+			saw_ack |= sp->hdr.type == RXRPC_PACKET_TYPE_ACK;
+
+			rxrpc_input_call_packet(call, skb);
+			rxrpc_free_skb(skb, rxrpc_skb_put_call_rx);
+			did_receive = true;
+		}
+
+		t = ktime_sub(call->rack_timo_at, ktime_get_real());
+		if (t <= 0) {
+			trace_rxrpc_timer_exp(call, t,
+					      rxrpc_timer_trace_rack_off + call->rack_timer_mode);
+			call->rack_timo_at = KTIME_MAX;
+			rxrpc_rack_timer_expired(call, t);
+		}
+
+	} while (!skb_queue_empty(&call->rx_queue));
+
+	/* If we see our async-event poke, check for timeout trippage. */
+	now = ktime_get_real();
+	t = ktime_sub(call->expect_rx_by, now);
+	if (t <= 0) {
+		trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_expect_rx);
+		goto expired;
+	}
+
+	t = ktime_sub(call->expect_req_by, now);
+	if (t <= 0) {
+		call->expect_req_by = KTIME_MAX;
+		if (__rxrpc_call_state(call) == RXRPC_CALL_SERVER_RECV_REQUEST) {
+			trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_idle);
+			goto expired;
+		}
+	}
+
+	t = ktime_sub(READ_ONCE(call->expect_term_by), now);
+	if (t <= 0) {
+		trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_hard);
+		goto expired;
+	}
+
+	t = ktime_sub(call->delay_ack_at, now);
+	if (t <= 0) {
+		trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_delayed_ack);
+		call->delay_ack_at = KTIME_MAX;
+		rxrpc_send_ACK(call, RXRPC_ACK_DELAY, 0,
+			       rxrpc_propose_ack_delayed_ack);
+	}
+
+	t = ktime_sub(call->ping_at, now);
+	if (t <= 0) {
+		trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_ping);
+		call->ping_at = KTIME_MAX;
+		rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+			       rxrpc_propose_ack_ping_for_keepalive);
+	}
+
+	now = ktime_get_real();
+	t = ktime_sub(call->keepalive_at, now);
+	if (t <= 0) {
+		trace_rxrpc_timer_exp(call, t, rxrpc_timer_trace_keepalive);
+		call->keepalive_at = KTIME_MAX;
+		rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+			       rxrpc_propose_ack_ping_for_keepalive);
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_EV_INITIAL_PING, &call->events))
+		rxrpc_send_initial_ping(call);
+
+	rxrpc_transmit_some_data(call, UINT_MAX, rxrpc_txdata_new_data);
+
+	if (saw_ack)
+		rxrpc_congestion_degrade(call);
+
+	if (did_receive &&
+	    (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_SEND_REQUEST ||
+	     __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SEND_REPLY)) {
+		t = ktime_sub(call->rack_timo_at, ktime_get_real());
+		trace_rxrpc_rack(call, t);
+	}
+
+	/* Process events */
+	if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events))
+		rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+			       rxrpc_propose_ack_ping_for_lost_ack);
+
+	if (call->tx_nr_lost > 0 &&
+	    __rxrpc_call_state(call) != RXRPC_CALL_CLIENT_RECV_REPLY &&
+	    !test_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags))
+		rxrpc_resend(call);
+
+	if (test_and_clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags))
+		rxrpc_send_ACK(call, RXRPC_ACK_IDLE, 0,
+			       rxrpc_propose_ack_rx_idle);
+
+	if (call->ackr_nr_unacked > 2) {
+		if (call->rtt_count < 3)
+			rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+				       rxrpc_propose_ack_ping_for_rtt);
+		else if (ktime_before(ktime_add_ms(call->rtt_last_req, 1000),
+				      ktime_get_real()))
+			rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+				       rxrpc_propose_ack_ping_for_old_rtt);
+		else
+			rxrpc_send_ACK(call, RXRPC_ACK_IDLE, 0,
+				       rxrpc_propose_ack_input_data);
+	}
+
+	/* Make sure the timer is restarted */
+	if (!__rxrpc_call_is_complete(call)) {
+		ktime_t next = READ_ONCE(call->expect_term_by), delay;
+
+#define set(T) { ktime_t _t = (T); if (ktime_before(_t, next)) next = _t; }
+
+		set(call->expect_req_by);
+		set(call->expect_rx_by);
+		set(call->delay_ack_at);
+		set(call->rack_timo_at);
+		set(call->keepalive_at);
+		set(call->ping_at);
+
+		now = ktime_get_real();
+		delay = ktime_sub(next, now);
+		if (delay <= 0) {
+			rxrpc_poke_call(call, rxrpc_call_poke_timer_now);
+		} else {
+			unsigned long nowj = jiffies, delayj, nextj;
+
+			delayj = umax(nsecs_to_jiffies(delay), 1);
+			nextj = nowj + delayj;
+			if (time_before(nextj, call->timer.expires) ||
+			    !timer_pending(&call->timer)) {
+				trace_rxrpc_timer_restart(call, delay, delayj);
+				timer_reduce(&call->timer, nextj);
+			}
+		}
+	}
+
+out:
+	if (__rxrpc_call_is_complete(call)) {
+		timer_delete_sync(&call->timer);
+		if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+			rxrpc_disconnect_call(call);
+		if (call->security)
+			call->security->free_call_crypto(call);
+	} else {
+		if (did_receive &&
+		    call->peer->ackr_adv_pmtud &&
+		    call->peer->pmtud_pending)
+			rxrpc_send_probe_for_pmtud(call);
+	}
+	_leave("");
+	return true;
+
+expired:
+	if (test_bit(RXRPC_CALL_RX_HEARD, &call->flags) &&
+	    (int)call->conn->hi_serial - (int)call->rx_serial > 0) {
+		trace_rxrpc_call_reset(call);
+		rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ECONNRESET,
+				 rxrpc_abort_call_reset);
+	} else {
+		rxrpc_abort_call(call, 0, RX_CALL_TIMEOUT, -ETIME,
+				 rxrpc_abort_call_timeout);
+	}
+	goto out;
+}
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
new file mode 100644
index 000000000..817ed9acb
--- /dev/null
+++ b/net/rxrpc/call_object.c
@@ -0,0 +1,777 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC individual remote procedure call handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/spinlock_types.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
+	[RXRPC_CALL_UNINITIALISED]		= "Uninit  ",
+	[RXRPC_CALL_CLIENT_AWAIT_CONN]		= "ClWtConn",
+	[RXRPC_CALL_CLIENT_PRE_SEND]		= "ClPreSnd",
+	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
+	[RXRPC_CALL_CLIENT_AWAIT_ACK]		= "ClAwtAck",
+	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
+	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
+	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
+	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
+	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
+	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
+	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
+	[RXRPC_CALL_COMPLETE]			= "Complete",
+};
+
+const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
+	[RXRPC_CALL_SUCCEEDED]			= "Complete",
+	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
+	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
+	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
+	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
+};
+
+struct kmem_cache *rxrpc_call_jar;
+
+static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
+static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
+
+void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
+{
+	struct rxrpc_local *local = call->local;
+	bool busy;
+
+	if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) {
+		spin_lock_irq(&local->lock);
+		busy = !list_empty(&call->attend_link);
+		trace_rxrpc_poke_call(call, busy, what);
+		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
+			busy = true;
+		if (!busy) {
+			list_add_tail(&call->attend_link, &local->call_attend_q);
+		}
+		spin_unlock_irq(&local->lock);
+		if (!busy)
+			rxrpc_wake_up_io_thread(local);
+	}
+}
+
+static void rxrpc_call_timer_expired(struct timer_list *t)
+{
+	struct rxrpc_call *call = timer_container_of(call, t, timer);
+
+	_enter("%d", call->debug_id);
+
+	if (!__rxrpc_call_is_complete(call)) {
+		trace_rxrpc_timer_expired(call);
+		rxrpc_poke_call(call, rxrpc_call_poke_timer);
+	}
+}
+
+static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
+
+static void rxrpc_destroy_call(struct work_struct *);
+
+/*
+ * find an extant server call
+ * - called in process context with IRQs enabled
+ */
+struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
+					      unsigned long user_call_ID)
+{
+	struct rxrpc_call *call;
+	struct rb_node *p;
+
+	_enter("%p,%lx", rx, user_call_ID);
+
+	read_lock(&rx->call_lock);
+
+	p = rx->calls.rb_node;
+	while (p) {
+		call = rb_entry(p, struct rxrpc_call, sock_node);
+
+		if (user_call_ID < call->user_call_ID)
+			p = p->rb_left;
+		else if (user_call_ID > call->user_call_ID)
+			p = p->rb_right;
+		else
+			goto found_extant_call;
+	}
+
+	read_unlock(&rx->call_lock);
+	_leave(" = NULL");
+	return NULL;
+
+found_extant_call:
+	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
+	read_unlock(&rx->call_lock);
+	_leave(" = %p [%d]", call, refcount_read(&call->ref));
+	return call;
+}
+
+/*
+ * allocate a new call
+ */
+struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
+				    unsigned int debug_id)
+{
+	struct rxrpc_call *call;
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
+
+	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
+	if (!call)
+		return NULL;
+
+	mutex_init(&call->user_mutex);
+
+	/* Prevent lockdep reporting a deadlock false positive between the afs
+	 * filesystem and sys_sendmsg() via the mmap sem.
+	 */
+	if (rx->sk.sk_kern_sock)
+		lockdep_set_class(&call->user_mutex,
+				  &rxrpc_call_user_mutex_lock_class_key);
+
+	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
+	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
+	INIT_LIST_HEAD(&call->link);
+	INIT_LIST_HEAD(&call->wait_link);
+	INIT_LIST_HEAD(&call->accept_link);
+	INIT_LIST_HEAD(&call->recvmsg_link);
+	INIT_LIST_HEAD(&call->sock_link);
+	INIT_LIST_HEAD(&call->attend_link);
+	skb_queue_head_init(&call->recvmsg_queue);
+	skb_queue_head_init(&call->rx_queue);
+	skb_queue_head_init(&call->rx_oos_queue);
+	init_waitqueue_head(&call->waitq);
+	spin_lock_init(&call->notify_lock);
+	refcount_set(&call->ref, 1);
+	call->debug_id		= debug_id;
+	call->rx_pkt_offset	= USHRT_MAX;
+	call->tx_total_len	= -1;
+	call->tx_jumbo_max	= 1;
+	call->next_rx_timo	= 20 * HZ;
+	call->next_req_timo	= 1 * HZ;
+	call->ackr_window	= 1;
+	call->ackr_wtop		= 1;
+	call->delay_ack_at	= KTIME_MAX;
+	call->rack_timo_at	= KTIME_MAX;
+	call->ping_at		= KTIME_MAX;
+	call->keepalive_at	= KTIME_MAX;
+	call->expect_rx_by	= KTIME_MAX;
+	call->expect_req_by	= KTIME_MAX;
+	call->expect_term_by	= KTIME_MAX;
+
+	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
+
+	call->rx_winsize = rxrpc_rx_window_size;
+	call->tx_winsize = 16;
+
+	call->cong_cwnd = RXRPC_MIN_CWND;
+	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
+
+	rxrpc_call_init_rtt(call);
+
+	call->rxnet = rxnet;
+	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
+	atomic_inc(&rxnet->nr_calls);
+	return call;
+}
+
+/*
+ * Allocate a new client call.
+ */
+static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
+						  struct rxrpc_conn_parameters *cp,
+						  struct rxrpc_call_params *p,
+						  gfp_t gfp,
+						  unsigned int debug_id)
+{
+	struct rxrpc_call *call;
+	ktime_t now;
+	int ret;
+
+	_enter("");
+
+	call = rxrpc_alloc_call(rx, gfp, debug_id);
+	if (!call)
+		return ERR_PTR(-ENOMEM);
+	now = ktime_get_real();
+	call->acks_latest_ts	= now;
+	call->cong_tstamp	= now;
+	call->dest_srx		= cp->peer->srx;
+	call->dest_srx.srx_service = cp->service_id;
+	call->interruptibility	= p->interruptibility;
+	call->tx_total_len	= p->tx_total_len;
+	call->key		= key_get(cp->key);
+	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
+	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
+	call->security_level	= cp->security_level;
+	if (p->kernel)
+		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
+	if (cp->upgrade)
+		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
+	if (cp->exclusive)
+		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
+
+	if (p->timeouts.normal)
+		call->next_rx_timo = umin(p->timeouts.normal, 1);
+	if (p->timeouts.idle)
+		call->next_req_timo = umin(p->timeouts.idle, 1);
+	if (p->timeouts.hard)
+		call->hard_timo = p->timeouts.hard;
+
+	ret = rxrpc_init_client_call_security(call);
+	if (ret < 0) {
+		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
+		rxrpc_put_call(call, rxrpc_call_put_discard_error);
+		return ERR_PTR(ret);
+	}
+
+	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
+
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
+			 p->user_call_ID, rxrpc_call_new_client);
+
+	_leave(" = %p", call);
+	return call;
+}
+
+/*
+ * Initiate the call ack/resend/expiry timer.
+ */
+void rxrpc_start_call_timer(struct rxrpc_call *call)
+{
+	if (call->hard_timo) {
+		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
+
+		call->expect_term_by = ktime_add(ktime_get_real(), delay);
+		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
+	}
+	call->timer.expires = jiffies;
+}
+
+/*
+ * Wait for a call slot to become available.
+ */
+static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (p->kernel)
+		limiter = &rxrpc_kernel_call_limiter;
+	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
+		down(limiter);
+		return limiter;
+	}
+	return down_interruptible(limiter) < 0 ? NULL : limiter;
+}
+
+/*
+ * Release a call slot.
+ */
+static void rxrpc_put_call_slot(struct rxrpc_call *call)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
+		limiter = &rxrpc_kernel_call_limiter;
+	up(limiter);
+}
+
+/*
+ * Start the process of connecting a call.  We obtain a peer and a connection
+ * bundle, but the actual association of a call with a connection is offloaded
+ * to the I/O thread to simplify locking.
+ */
+static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
+{
+	struct rxrpc_local *local = call->local;
+	int ret = -ENOMEM;
+
+	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
+
+	ret = rxrpc_look_up_bundle(call, gfp);
+	if (ret < 0)
+		goto error;
+
+	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
+	rxrpc_get_call(call, rxrpc_call_get_io_thread);
+	spin_lock_irq(&local->client_call_lock);
+	list_add_tail(&call->wait_link, &local->new_client_calls);
+	spin_unlock_irq(&local->client_call_lock);
+	rxrpc_wake_up_io_thread(local);
+	return 0;
+
+error:
+	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+	return ret;
+}
+
+/*
+ * Set up a call for the given parameters.
+ * - Called with the socket lock held, which it must release.
+ * - If it returns a call, the call's lock will need releasing by the caller.
+ */
+struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
+					 struct rxrpc_conn_parameters *cp,
+					 struct rxrpc_call_params *p,
+					 gfp_t gfp,
+					 unsigned int debug_id)
+	__releases(&rx->sk.sk_lock)
+	__acquires(&call->user_mutex)
+{
+	struct rxrpc_call *call, *xcall;
+	struct rxrpc_net *rxnet;
+	struct semaphore *limiter;
+	struct rb_node *parent, **pp;
+	int ret;
+
+	_enter("%p,%lx", rx, p->user_call_ID);
+
+	if (WARN_ON_ONCE(!cp->peer)) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-EIO);
+	}
+
+	limiter = rxrpc_get_call_slot(p, gfp);
+	if (!limiter) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-ERESTARTSYS);
+	}
+
+	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
+	if (IS_ERR(call)) {
+		release_sock(&rx->sk);
+		up(limiter);
+		_leave(" = %ld", PTR_ERR(call));
+		return call;
+	}
+
+	/* We need to protect a partially set up call against the user as we
+	 * will be acting outside the socket lock.
+	 */
+	mutex_lock(&call->user_mutex);
+
+	/* Publish the call, even though it is incompletely set up as yet */
+	write_lock(&rx->call_lock);
+
+	pp = &rx->calls.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+
+		if (p->user_call_ID < xcall->user_call_ID)
+			pp = &(*pp)->rb_left;
+		else if (p->user_call_ID > xcall->user_call_ID)
+			pp = &(*pp)->rb_right;
+		else
+			goto error_dup_user_ID;
+	}
+
+	rcu_assign_pointer(call->socket, rx);
+	call->user_call_ID = p->user_call_ID;
+	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+	rxrpc_get_call(call, rxrpc_call_get_userid);
+	rb_link_node(&call->sock_node, parent, pp);
+	rb_insert_color(&call->sock_node, &rx->calls);
+	list_add(&call->sock_link, &rx->sock_calls);
+
+	write_unlock(&rx->call_lock);
+
+	rxnet = call->rxnet;
+	spin_lock(&rxnet->call_lock);
+	list_add_tail_rcu(&call->link, &rxnet->calls);
+	spin_unlock(&rxnet->call_lock);
+
+	/* From this point on, the call is protected by its own lock. */
+	release_sock(&rx->sk);
+
+	/* Set up or get a connection record and set the protocol parameters,
+	 * including channel number and call ID.
+	 */
+	ret = rxrpc_connect_call(call, gfp);
+	if (ret < 0)
+		goto error_attached_to_socket;
+
+	_leave(" = %p [new]", call);
+	return call;
+
+	/* We unexpectedly found the user ID in the list after taking
+	 * the call_lock.  This shouldn't happen unless the user races
+	 * with itself and tries to add the same user ID twice at the
+	 * same time in different threads.
+	 */
+error_dup_user_ID:
+	write_unlock(&rx->call_lock);
+	release_sock(&rx->sk);
+	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
+			 rxrpc_call_see_userid_exists);
+	mutex_unlock(&call->user_mutex);
+	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
+	_leave(" = -EEXIST");
+	return ERR_PTR(-EEXIST);
+
+	/* We got an error, but the call is attached to the socket and is in
+	 * need of release.  However, we might now race with recvmsg() when it
+	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
+	 * leave the error to recvmsg() to deal with.
+	 */
+error_attached_to_socket:
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
+			 rxrpc_call_see_connect_failed);
+	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
+	_leave(" = c=%08x [err]", call->debug_id);
+	return call;
+}
+
+/*
+ * Set up an incoming call.  call->conn points to the connection.
+ * This is called with interrupts disabled and isn't allowed to fail.
+ */
+void rxrpc_incoming_call(struct rxrpc_sock *rx,
+			 struct rxrpc_call *call,
+			 struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	u32 chan;
+
+	_enter(",%d", call->conn->debug_id);
+
+	rcu_assign_pointer(call->socket, rx);
+	call->call_id		= sp->hdr.callNumber;
+	call->dest_srx.srx_service = sp->hdr.serviceId;
+	call->cid		= sp->hdr.cid;
+	call->cong_tstamp	= skb->tstamp;
+
+	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
+	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
+
+	spin_lock(&conn->state_lock);
+
+	switch (conn->state) {
+	case RXRPC_CONN_SERVICE_UNSECURED:
+	case RXRPC_CONN_SERVICE_CHALLENGING:
+		__set_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags);
+		break;
+	case RXRPC_CONN_SERVICE:
+		break;
+
+	case RXRPC_CONN_ABORTED:
+		rxrpc_set_call_completion(call, conn->completion,
+					  conn->abort_code, conn->error);
+		break;
+	default:
+		BUG();
+	}
+
+	rxrpc_get_call(call, rxrpc_call_get_io_thread);
+
+	/* Set the channel for this call.  We don't get channel_lock as we're
+	 * only defending against the data_ready handler (which we're called
+	 * from) and the RESPONSE packet parser (which is only really
+	 * interested in call_counter and can cope with a disagreement with the
+	 * call pointer).
+	 */
+	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
+	conn->channels[chan].call_counter = call->call_id;
+	conn->channels[chan].call_id = call->call_id;
+	conn->channels[chan].call = call;
+	spin_unlock(&conn->state_lock);
+
+	spin_lock(&conn->peer->lock);
+	hlist_add_head(&call->error_link, &conn->peer->error_targets);
+	spin_unlock(&conn->peer->lock);
+
+	rxrpc_start_call_timer(call);
+	_leave("");
+}
+
+/*
+ * Note the re-emergence of a call.
+ */
+void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
+{
+	if (call) {
+		int r = refcount_read(&call->ref);
+
+		trace_rxrpc_call(call->debug_id, r, 0, why);
+	}
+}
+
+struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
+				      enum rxrpc_call_trace why)
+{
+	int r;
+
+	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
+		return NULL;
+	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
+	return call;
+}
+
+/*
+ * Note the addition of a ref on a call.
+ */
+void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
+{
+	int r;
+
+	__refcount_inc(&call->ref, &r);
+	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
+}
+
+/*
+ * Clean up the transmission buffers.
+ */
+static void rxrpc_cleanup_tx_buffers(struct rxrpc_call *call)
+{
+	struct rxrpc_txqueue *tq, *next;
+
+	for (tq = call->tx_queue; tq; tq = next) {
+		next = tq->next;
+		for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
+			if (tq->bufs[i])
+				rxrpc_put_txbuf(tq->bufs[i], rxrpc_txbuf_put_cleaned);
+		trace_rxrpc_tq(call, tq, 0, rxrpc_tq_cleaned);
+		kfree(tq);
+	}
+}
+
+/*
+ * Clean up the receive buffers.
+ */
+static void rxrpc_cleanup_rx_buffers(struct rxrpc_call *call)
+{
+	rxrpc_purge_queue(&call->recvmsg_queue);
+	rxrpc_purge_queue(&call->rx_queue);
+	rxrpc_purge_queue(&call->rx_oos_queue);
+	kfree(call->rx_dec_buffer);
+}
+
+/*
+ * Detach a call from its owning socket.
+ */
+void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn = call->conn;
+	bool putu = false;
+
+	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
+
+	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
+			 call->flags, rxrpc_call_see_release);
+
+	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
+		BUG();
+
+	rxrpc_put_call_slot(call);
+
+	/* Note that at this point, the call may still be on or may have been
+	 * added back on to the socket receive queue.  recvmsg() must discard
+	 * released calls.  The CALL_RELEASED flag should prevent further
+	 * notifications.
+	 */
+	spin_lock_irq(&rx->recvmsg_lock);
+	spin_unlock_irq(&rx->recvmsg_lock);
+
+	write_lock(&rx->call_lock);
+
+	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+		rb_erase(&call->sock_node, &rx->calls);
+		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
+		putu = true;
+	}
+
+	list_del(&call->sock_link);
+	write_unlock(&rx->call_lock);
+
+	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
+
+	if (putu)
+		rxrpc_put_call(call, rxrpc_call_put_userid);
+
+	_leave("");
+}
+
+/*
+ * release all the calls associated with a socket
+ */
+void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
+{
+	struct rxrpc_call *call;
+
+	_enter("%p", rx);
+
+	while (!list_empty(&rx->to_be_accepted)) {
+		call = list_entry(rx->to_be_accepted.next,
+				  struct rxrpc_call, accept_link);
+		list_del(&call->accept_link);
+		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
+				    rxrpc_abort_call_sock_release_tba);
+		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
+	}
+
+	while (!list_empty(&rx->sock_calls)) {
+		call = list_entry(rx->sock_calls.next,
+				  struct rxrpc_call, sock_link);
+		rxrpc_get_call(call, rxrpc_call_get_release_sock);
+		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
+				    rxrpc_abort_call_sock_release);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put_release_sock);
+	}
+
+	while ((call = list_first_entry_or_null(&rx->recvmsg_q,
+						struct rxrpc_call, recvmsg_link))) {
+		list_del_init(&call->recvmsg_link);
+		rxrpc_put_call(call, rxrpc_call_put_release_recvmsg_q);
+	}
+
+	_leave("");
+}
+
+/*
+ * release a call
+ */
+void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
+{
+	struct rxrpc_net *rxnet = call->rxnet;
+	unsigned int debug_id = call->debug_id;
+	bool dead;
+	int r;
+
+	ASSERT(call != NULL);
+
+	dead = __refcount_dec_and_test(&call->ref, &r);
+	trace_rxrpc_call(debug_id, r - 1, 0, why);
+	if (dead) {
+		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
+
+		spin_lock(&rxnet->call_lock);
+		list_del_rcu(&call->link);
+		spin_unlock(&rxnet->call_lock);
+
+		rxrpc_cleanup_call(call);
+	}
+}
+
+/*
+ * Free up the call under RCU.
+ */
+static void rxrpc_rcu_free_call(struct rcu_head *rcu)
+{
+	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
+	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
+
+	kmem_cache_free(rxrpc_call_jar, call);
+	if (atomic_dec_and_test(&rxnet->nr_calls))
+		wake_up_var(&rxnet->nr_calls);
+}
+
+/*
+ * Final call destruction - but must be done in process context.
+ */
+static void rxrpc_destroy_call(struct work_struct *work)
+{
+	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
+
+	timer_delete_sync(&call->timer);
+
+	rxrpc_cleanup_tx_buffers(call);
+	rxrpc_cleanup_rx_buffers(call);
+	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
+	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
+	rxrpc_deactivate_bundle(call->bundle);
+	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
+	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
+	rxrpc_put_local(call->local, rxrpc_local_put_call);
+	key_put(call->key);
+	call_rcu(&call->rcu, rxrpc_rcu_free_call);
+}
+
+/*
+ * clean up a call
+ */
+void rxrpc_cleanup_call(struct rxrpc_call *call)
+{
+	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
+
+	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
+	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
+
+	timer_delete(&call->timer);
+
+	if (rcu_read_lock_held())
+		/* Can't use the rxrpc workqueue as we need to cancel/flush
+		 * something that may be running/waiting there.
+		 */
+		schedule_work(&call->destroyer);
+	else
+		rxrpc_destroy_call(&call->destroyer);
+}
+
+/*
+ * Make sure that all calls are gone from a network namespace.  To reach this
+ * point, any open UDP sockets in that namespace must have been closed, so any
+ * outstanding calls cannot be doing I/O.
+ */
+void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_call *call;
+
+	_enter("");
+
+	if (!list_empty(&rxnet->calls)) {
+		int shown = 0;
+
+		spin_lock(&rxnet->call_lock);
+
+		list_for_each_entry(call, &rxnet->calls, link) {
+			rxrpc_see_call(call, rxrpc_call_see_still_live);
+
+			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
+			       call, refcount_read(&call->ref),
+			       rxrpc_call_states[__rxrpc_call_state(call)],
+			       call->flags, call->events);
+
+			if (++shown >= 10)
+				break;
+		}
+
+		spin_unlock(&rxnet->call_lock);
+	}
+
+	atomic_dec(&rxnet->nr_calls);
+	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
+}
+
+/**
+ * rxrpc_kernel_query_call_security - Query call's security parameters
+ * @call: The call to query
+ * @_service_id: Where to return the service ID
+ * @_enctype: Where to return the "encoding type"
+ *
+ * This queries the security parameters of a call, setting *@_service_id and
+ * *@_enctype and returning the security class.
+ *
+ * Return: The security class protocol number.
+ */
+u8 rxrpc_kernel_query_call_security(struct rxrpc_call *call,
+				    u16 *_service_id, u32 *_enctype)
+{
+	*_service_id = call->dest_srx.srx_service;
+	*_enctype = call->security_enctype;
+	return call->security_ix;
+}
+EXPORT_SYMBOL(rxrpc_kernel_query_call_security);
diff --git a/net/rxrpc/call_state.c b/net/rxrpc/call_state.c
new file mode 100644
index 000000000..6afb54373
--- /dev/null
+++ b/net/rxrpc/call_state.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Call state changing functions.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include "ar-internal.h"
+
+/*
+ * Transition a call to the complete state.
+ */
+bool rxrpc_set_call_completion(struct rxrpc_call *call,
+				 enum rxrpc_call_completion compl,
+				 u32 abort_code,
+				 int error)
+{
+	if (__rxrpc_call_state(call) == RXRPC_CALL_COMPLETE)
+		return false;
+
+	call->abort_code = abort_code;
+	call->error = error;
+	call->completion = compl;
+	/* Allow reader of completion state to operate locklessly */
+	rxrpc_set_call_state(call, RXRPC_CALL_COMPLETE);
+	trace_rxrpc_call_complete(call);
+	wake_up(&call->waitq);
+	rxrpc_notify_socket(call);
+	return true;
+}
+
+/*
+ * Record that a call successfully completed.
+ */
+bool rxrpc_call_completed(struct rxrpc_call *call)
+{
+	return rxrpc_set_call_completion(call, RXRPC_CALL_SUCCEEDED, 0, 0);
+}
+
+/*
+ * Record that a call is locally aborted.
+ */
+bool rxrpc_abort_call(struct rxrpc_call *call, rxrpc_seq_t seq,
+		      u32 abort_code, int error, enum rxrpc_abort_reason why)
+{
+	trace_rxrpc_abort(call->debug_id, why, call->cid, call->call_id, seq,
+			  abort_code, error);
+	if (!rxrpc_set_call_completion(call, RXRPC_CALL_LOCALLY_ABORTED,
+				       abort_code, error))
+		return false;
+	if (test_bit(RXRPC_CALL_EXPOSED, &call->flags))
+		rxrpc_send_abort_packet(call);
+	return true;
+}
+
+/*
+ * Record that a call errored out before even getting off the ground, thereby
+ * setting the state to allow it to be destroyed.
+ */
+void rxrpc_prefail_call(struct rxrpc_call *call, enum rxrpc_call_completion compl,
+			int error)
+{
+	call->abort_code	= RX_CALL_DEAD;
+	call->error		= error;
+	call->completion	= compl;
+	call->_state		= RXRPC_CALL_COMPLETE;
+	trace_rxrpc_call_complete(call);
+	WARN_ON_ONCE(__test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags));
+}
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
new file mode 100644
index 000000000..48519f0de
--- /dev/null
+++ b/net/rxrpc/conn_client.c
@@ -0,0 +1,833 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Client connection-specific management code.
+ *
+ * Copyright (C) 2016, 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * Client connections need to be cached for a little while after they've made a
+ * call so as to handle retransmitted DATA packets in case the server didn't
+ * receive the final ACK or terminating ABORT we sent it.
+ *
+ * There are flags of relevance to the cache:
+ *
+ *  (2) DONT_REUSE - The connection should be discarded as soon as possible and
+ *      should not be reused.  This is set when an exclusive connection is used
+ *      or a call ID counter overflows.
+ *
+ * The caching state may only be changed if the cache lock is held.
+ *
+ * There are two idle client connection expiry durations.  If the total number
+ * of connections is below the reap threshold, we use the normal duration; if
+ * it's above, we use the fast duration.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/timer.h>
+#include <linux/sched/signal.h>
+
+#include "ar-internal.h"
+
+__read_mostly unsigned int rxrpc_reap_client_connections = 900;
+__read_mostly unsigned long rxrpc_conn_idle_client_expiry = 2 * 60 * HZ;
+__read_mostly unsigned long rxrpc_conn_idle_client_fast_expiry = 2 * HZ;
+
+static void rxrpc_activate_bundle(struct rxrpc_bundle *bundle)
+{
+	atomic_inc(&bundle->active);
+}
+
+/*
+ * Release a connection ID for a client connection.
+ */
+static void rxrpc_put_client_connection_id(struct rxrpc_local *local,
+					   struct rxrpc_connection *conn)
+{
+	idr_remove(&local->conn_ids, conn->proto.cid >> RXRPC_CIDSHIFT);
+}
+
+/*
+ * Destroy the client connection ID tree.
+ */
+static void rxrpc_destroy_client_conn_ids(struct rxrpc_local *local)
+{
+	struct rxrpc_connection *conn;
+	int id;
+
+	if (!idr_is_empty(&local->conn_ids)) {
+		idr_for_each_entry(&local->conn_ids, conn, id) {
+			pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
+			       conn, refcount_read(&conn->ref));
+		}
+		BUG();
+	}
+
+	idr_destroy(&local->conn_ids);
+}
+
+/*
+ * Allocate a connection bundle.
+ */
+static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_call *call,
+					       gfp_t gfp)
+{
+	static atomic_t rxrpc_bundle_id;
+	struct rxrpc_bundle *bundle;
+
+	bundle = kzalloc_obj(*bundle, gfp);
+	if (bundle) {
+		bundle->local		= call->local;
+		bundle->peer		= rxrpc_get_peer(call->peer, rxrpc_peer_get_bundle);
+		bundle->key		= key_get(call->key);
+		bundle->security	= call->security;
+		bundle->exclusive	= test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
+		bundle->upgrade		= test_bit(RXRPC_CALL_UPGRADE, &call->flags);
+		bundle->service_id	= call->dest_srx.srx_service;
+		bundle->security_level	= call->security_level;
+		bundle->debug_id	= atomic_inc_return(&rxrpc_bundle_id);
+		refcount_set(&bundle->ref, 1);
+		atomic_set(&bundle->active, 1);
+		INIT_LIST_HEAD(&bundle->waiting_calls);
+		trace_rxrpc_bundle(bundle->debug_id, 1, rxrpc_bundle_new);
+
+		write_lock(&bundle->local->rxnet->conn_lock);
+		list_add_tail(&bundle->proc_link, &bundle->local->rxnet->bundle_proc_list);
+		write_unlock(&bundle->local->rxnet->conn_lock);
+	}
+	return bundle;
+}
+
+struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle,
+				      enum rxrpc_bundle_trace why)
+{
+	int r;
+
+	__refcount_inc(&bundle->ref, &r);
+	trace_rxrpc_bundle(bundle->debug_id, r + 1, why);
+	return bundle;
+}
+
+static void rxrpc_free_bundle(struct rxrpc_bundle *bundle)
+{
+	trace_rxrpc_bundle(bundle->debug_id, refcount_read(&bundle->ref),
+			   rxrpc_bundle_free);
+	write_lock(&bundle->local->rxnet->conn_lock);
+	list_del(&bundle->proc_link);
+	write_unlock(&bundle->local->rxnet->conn_lock);
+	rxrpc_put_peer(bundle->peer, rxrpc_peer_put_bundle);
+	key_put(bundle->key);
+	kfree(bundle);
+}
+
+void rxrpc_put_bundle(struct rxrpc_bundle *bundle, enum rxrpc_bundle_trace why)
+{
+	unsigned int id;
+	bool dead;
+	int r;
+
+	if (bundle) {
+		id = bundle->debug_id;
+		dead = __refcount_dec_and_test(&bundle->ref, &r);
+		trace_rxrpc_bundle(id, r - 1, why);
+		if (dead)
+			rxrpc_free_bundle(bundle);
+	}
+}
+
+/*
+ * Get rid of outstanding client connection preallocations when a local
+ * endpoint is destroyed.
+ */
+void rxrpc_purge_client_connections(struct rxrpc_local *local)
+{
+	rxrpc_destroy_client_conn_ids(local);
+}
+
+/*
+ * Allocate a client connection.
+ */
+static struct rxrpc_connection *
+rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_local *local = bundle->local;
+	struct rxrpc_net *rxnet = local->rxnet;
+	int id;
+
+	_enter("");
+
+	conn = rxrpc_alloc_connection(rxnet, GFP_ATOMIC | __GFP_NOWARN);
+	if (!conn)
+		return ERR_PTR(-ENOMEM);
+
+	id = idr_alloc_cyclic(&local->conn_ids, conn, 1, 0x40000000,
+			      GFP_ATOMIC | __GFP_NOWARN);
+	if (id < 0) {
+		kfree(conn);
+		return ERR_PTR(id);
+	}
+
+	refcount_set(&conn->ref, 1);
+	conn->proto.cid		= id << RXRPC_CIDSHIFT;
+	conn->proto.epoch	= local->rxnet->epoch;
+	conn->out_clientflag	= RXRPC_CLIENT_INITIATED;
+	conn->bundle		= rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_conn);
+	conn->local		= rxrpc_get_local(bundle->local, rxrpc_local_get_client_conn);
+	conn->peer		= rxrpc_get_peer(bundle->peer, rxrpc_peer_get_client_conn);
+	conn->key		= key_get(bundle->key);
+	conn->security		= bundle->security;
+	conn->exclusive		= bundle->exclusive;
+	conn->upgrade		= bundle->upgrade;
+	conn->orig_service_id	= bundle->service_id;
+	conn->security_level	= bundle->security_level;
+	conn->state		= RXRPC_CONN_CLIENT_UNSECURED;
+	conn->service_id	= conn->orig_service_id;
+
+	if (conn->security == &rxrpc_no_security)
+		conn->state	= RXRPC_CONN_CLIENT;
+
+	atomic_inc(&rxnet->nr_conns);
+	write_lock(&rxnet->conn_lock);
+	list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+	write_unlock(&rxnet->conn_lock);
+
+	rxrpc_see_connection(conn, rxrpc_conn_new_client);
+
+	atomic_inc(&rxnet->nr_client_conns);
+	trace_rxrpc_client(conn, -1, rxrpc_client_alloc);
+	return conn;
+}
+
+/*
+ * Determine if a connection may be reused.
+ */
+static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_net *rxnet;
+	int id_cursor, id, distance, limit;
+
+	if (!conn)
+		goto dont_reuse;
+
+	rxnet = conn->rxnet;
+	if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
+		goto dont_reuse;
+
+	if ((conn->state != RXRPC_CONN_CLIENT_UNSECURED &&
+	     conn->state != RXRPC_CONN_CLIENT) ||
+	    conn->proto.epoch != rxnet->epoch)
+		goto mark_dont_reuse;
+
+	/* The IDR tree gets very expensive on memory if the connection IDs are
+	 * widely scattered throughout the number space, so we shall want to
+	 * kill off connections that, say, have an ID more than about four
+	 * times the maximum number of client conns away from the current
+	 * allocation point to try and keep the IDs concentrated.
+	 */
+	id_cursor = idr_get_cursor(&conn->local->conn_ids);
+	id = conn->proto.cid >> RXRPC_CIDSHIFT;
+	distance = id - id_cursor;
+	if (distance < 0)
+		distance = -distance;
+	limit = umax(atomic_read(&rxnet->nr_conns) * 4, 1024);
+	if (distance > limit)
+		goto mark_dont_reuse;
+
+	return true;
+
+mark_dont_reuse:
+	set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+dont_reuse:
+	return false;
+}
+
+/*
+ * Look up the conn bundle that matches the connection parameters, adding it if
+ * it doesn't yet exist.
+ */
+int rxrpc_look_up_bundle(struct rxrpc_call *call, gfp_t gfp)
+{
+	struct rxrpc_bundle *bundle, *candidate;
+	struct rxrpc_local *local = call->local;
+	struct rb_node *p, **pp, *parent;
+	long diff;
+	bool upgrade = test_bit(RXRPC_CALL_UPGRADE, &call->flags);
+
+	_enter("{%px,%x,%u,%u}",
+	       call->peer, key_serial(call->key), call->security_level,
+	       upgrade);
+
+	if (test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags)) {
+		call->bundle = rxrpc_alloc_bundle(call, gfp);
+		return call->bundle ? 0 : -ENOMEM;
+	}
+
+	/* First, see if the bundle is already there. */
+	_debug("search 1");
+	spin_lock(&local->client_bundles_lock);
+	p = local->client_bundles.rb_node;
+	while (p) {
+		bundle = rb_entry(p, struct rxrpc_bundle, local_node);
+
+#define cmp(X, Y) ((long)(X) - (long)(Y))
+		diff = (cmp(bundle->peer, call->peer) ?:
+			cmp(bundle->key, call->key) ?:
+			cmp(bundle->security_level, call->security_level) ?:
+			cmp(bundle->upgrade, upgrade));
+#undef cmp
+		if (diff < 0)
+			p = p->rb_left;
+		else if (diff > 0)
+			p = p->rb_right;
+		else
+			goto found_bundle;
+	}
+	spin_unlock(&local->client_bundles_lock);
+	_debug("not found");
+
+	/* It wasn't.  We need to add one. */
+	candidate = rxrpc_alloc_bundle(call, gfp);
+	if (!candidate)
+		return -ENOMEM;
+
+	_debug("search 2");
+	spin_lock(&local->client_bundles_lock);
+	pp = &local->client_bundles.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		bundle = rb_entry(parent, struct rxrpc_bundle, local_node);
+
+#define cmp(X, Y) ((long)(X) - (long)(Y))
+		diff = (cmp(bundle->peer, call->peer) ?:
+			cmp(bundle->key, call->key) ?:
+			cmp(bundle->security_level, call->security_level) ?:
+			cmp(bundle->upgrade, upgrade));
+#undef cmp
+		if (diff < 0)
+			pp = &(*pp)->rb_left;
+		else if (diff > 0)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_bundle_free;
+	}
+
+	_debug("new bundle");
+	rb_link_node(&candidate->local_node, parent, pp);
+	rb_insert_color(&candidate->local_node, &local->client_bundles);
+	call->bundle = rxrpc_get_bundle(candidate, rxrpc_bundle_get_client_call);
+	spin_unlock(&local->client_bundles_lock);
+	_leave(" = B=%u [new]", call->bundle->debug_id);
+	return 0;
+
+found_bundle_free:
+	rxrpc_free_bundle(candidate);
+found_bundle:
+	call->bundle = rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_call);
+	rxrpc_activate_bundle(bundle);
+	spin_unlock(&local->client_bundles_lock);
+	_leave(" = B=%u [found]", call->bundle->debug_id);
+	return 0;
+}
+
+/*
+ * Allocate a new connection and add it into a bundle.
+ */
+static bool rxrpc_add_conn_to_bundle(struct rxrpc_bundle *bundle,
+				     unsigned int slot)
+{
+	struct rxrpc_connection *conn, *old;
+	unsigned int shift = slot * RXRPC_MAXCALLS;
+	unsigned int i;
+
+	old = bundle->conns[slot];
+	if (old) {
+		bundle->conns[slot] = NULL;
+		bundle->conn_ids[slot] = 0;
+		trace_rxrpc_client(old, -1, rxrpc_client_replace);
+		rxrpc_put_connection(old, rxrpc_conn_put_noreuse);
+	}
+
+	conn = rxrpc_alloc_client_connection(bundle);
+	if (IS_ERR(conn)) {
+		bundle->alloc_error = PTR_ERR(conn);
+		return false;
+	}
+
+	rxrpc_activate_bundle(bundle);
+	conn->bundle_shift = shift;
+	bundle->conns[slot] = conn;
+	bundle->conn_ids[slot] = conn->debug_id;
+	for (i = 0; i < RXRPC_MAXCALLS; i++)
+		set_bit(shift + i, &bundle->avail_chans);
+	return true;
+}
+
+/*
+ * Add a connection to a bundle if there are no usable connections or we have
+ * connections waiting for extra capacity.
+ */
+static bool rxrpc_bundle_has_space(struct rxrpc_bundle *bundle)
+{
+	int slot = -1, i, usable;
+
+	_enter("");
+
+	bundle->alloc_error = 0;
+
+	/* See if there are any usable connections. */
+	usable = 0;
+	for (i = 0; i < ARRAY_SIZE(bundle->conns); i++) {
+		if (rxrpc_may_reuse_conn(bundle->conns[i]))
+			usable++;
+		else if (slot == -1)
+			slot = i;
+	}
+
+	if (!usable && bundle->upgrade)
+		bundle->try_upgrade = true;
+
+	if (!usable)
+		goto alloc_conn;
+
+	if (!bundle->avail_chans &&
+	    !bundle->try_upgrade &&
+	    usable < ARRAY_SIZE(bundle->conns))
+		goto alloc_conn;
+
+	_leave("");
+	return usable;
+
+alloc_conn:
+	return slot >= 0 ? rxrpc_add_conn_to_bundle(bundle, slot) : false;
+}
+
+/*
+ * Assign a channel to the call at the front of the queue and wake the call up.
+ * We don't increment the callNumber counter until this number has been exposed
+ * to the world.
+ */
+static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
+				       unsigned int channel)
+{
+	struct rxrpc_channel *chan = &conn->channels[channel];
+	struct rxrpc_bundle *bundle = conn->bundle;
+	struct rxrpc_call *call = list_entry(bundle->waiting_calls.next,
+					     struct rxrpc_call, wait_link);
+	u32 call_id = chan->call_counter + 1;
+
+	_enter("C=%x,%u", conn->debug_id, channel);
+
+	list_del_init(&call->wait_link);
+
+	trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate);
+
+	/* Cancel the final ACK on the previous call if it hasn't been sent yet
+	 * as the DATA packet will implicitly ACK it.
+	 */
+	clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+	clear_bit(conn->bundle_shift + channel, &bundle->avail_chans);
+
+	rxrpc_see_call(call, rxrpc_call_see_activate_client);
+	call->conn	= rxrpc_get_connection(conn, rxrpc_conn_get_activate_call);
+	call->cid	= conn->proto.cid | channel;
+	call->call_id	= call_id;
+	call->dest_srx.srx_service = conn->service_id;
+	call->cong_ssthresh = call->peer->cong_ssthresh;
+	if (call->cong_cwnd >= call->cong_ssthresh)
+		call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE;
+	else
+		call->cong_ca_state = RXRPC_CA_SLOW_START;
+
+	chan->call_id		= call_id;
+	chan->call_debug_id	= call->debug_id;
+	chan->call		= call;
+
+	rxrpc_see_call(call, rxrpc_call_see_connected);
+	trace_rxrpc_connect_call(call);
+	call->tx_last_sent = ktime_get_real();
+	rxrpc_start_call_timer(call);
+	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_PRE_SEND);
+	wake_up(&call->waitq);
+}
+
+/*
+ * Remove a connection from the idle list if it's on it.
+ */
+static void rxrpc_unidle_conn(struct rxrpc_connection *conn)
+{
+	if (!list_empty(&conn->cache_link)) {
+		list_del_init(&conn->cache_link);
+		rxrpc_put_connection(conn, rxrpc_conn_put_unidle);
+	}
+}
+
+/*
+ * Assign channels and callNumbers to waiting calls.
+ */
+static void rxrpc_activate_channels(struct rxrpc_bundle *bundle)
+{
+	struct rxrpc_connection *conn;
+	unsigned long avail, mask;
+	unsigned int channel, slot;
+
+	trace_rxrpc_client(NULL, -1, rxrpc_client_activate_chans);
+
+	if (bundle->try_upgrade)
+		mask = 1;
+	else
+		mask = ULONG_MAX;
+
+	while (!list_empty(&bundle->waiting_calls)) {
+		avail = bundle->avail_chans & mask;
+		if (!avail)
+			break;
+		channel = __ffs(avail);
+		clear_bit(channel, &bundle->avail_chans);
+
+		slot = channel / RXRPC_MAXCALLS;
+		conn = bundle->conns[slot];
+		if (!conn)
+			break;
+
+		if (bundle->try_upgrade)
+			set_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags);
+		rxrpc_unidle_conn(conn);
+
+		channel &= (RXRPC_MAXCALLS - 1);
+		conn->act_chans	|= 1 << channel;
+		rxrpc_activate_one_channel(conn, channel);
+	}
+}
+
+/*
+ * Connect waiting channels (called from the I/O thread).
+ */
+void rxrpc_connect_client_calls(struct rxrpc_local *local)
+{
+	struct rxrpc_call *call;
+	LIST_HEAD(new_client_calls);
+
+	spin_lock_irq(&local->client_call_lock);
+	list_splice_tail_init(&local->new_client_calls, &new_client_calls);
+	spin_unlock_irq(&local->client_call_lock);
+
+	while ((call = list_first_entry_or_null(&new_client_calls,
+						struct rxrpc_call, wait_link))) {
+		struct rxrpc_bundle *bundle = call->bundle;
+
+		list_move_tail(&call->wait_link, &bundle->waiting_calls);
+		rxrpc_see_call(call, rxrpc_call_see_waiting_call);
+
+		if (rxrpc_bundle_has_space(bundle))
+			rxrpc_activate_channels(bundle);
+	}
+}
+
+/*
+ * Note that a call, and thus a connection, is about to be exposed to the
+ * world.
+ */
+void rxrpc_expose_client_call(struct rxrpc_call *call)
+{
+	unsigned int channel = call->cid & RXRPC_CHANNELMASK;
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_channel *chan = &conn->channels[channel];
+
+	if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		/* Mark the call ID as being used.  If the callNumber counter
+		 * exceeds ~2 billion, we kill the connection after its
+		 * outstanding calls have finished so that the counter doesn't
+		 * wrap.
+		 */
+		chan->call_counter++;
+		if (chan->call_counter >= INT_MAX)
+			set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+		trace_rxrpc_client(conn, channel, rxrpc_client_exposed);
+
+		spin_lock_irq(&call->peer->lock);
+		hlist_add_head(&call->error_link, &call->peer->error_targets);
+		spin_unlock_irq(&call->peer->lock);
+	}
+}
+
+/*
+ * Set the reap timer.
+ */
+static void rxrpc_set_client_reap_timer(struct rxrpc_local *local)
+{
+	if (!local->kill_all_client_conns) {
+		unsigned long now = jiffies;
+		unsigned long reap_at = now + rxrpc_conn_idle_client_expiry;
+
+		if (local->rxnet->live)
+			timer_reduce(&local->client_conn_reap_timer, reap_at);
+	}
+}
+
+/*
+ * Disconnect a client call.
+ */
+void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_channel *chan = NULL;
+	struct rxrpc_local *local = bundle->local;
+	unsigned int channel;
+	bool may_reuse;
+	u32 cid;
+
+	_enter("c=%x", call->debug_id);
+
+	/* Calls that have never actually been assigned a channel can simply be
+	 * discarded.
+	 */
+	conn = call->conn;
+	if (!conn) {
+		_debug("call is waiting");
+		ASSERTCMP(call->call_id, ==, 0);
+		ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags));
+		/* May still be on ->new_client_calls. */
+		spin_lock_irq(&local->client_call_lock);
+		list_del_init(&call->wait_link);
+		spin_unlock_irq(&local->client_call_lock);
+		return;
+	}
+
+	cid = call->cid;
+	channel = cid & RXRPC_CHANNELMASK;
+	chan = &conn->channels[channel];
+	trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
+
+	if (WARN_ON(chan->call != call))
+		return;
+
+	may_reuse = rxrpc_may_reuse_conn(conn);
+
+	/* If a client call was exposed to the world, we save the result for
+	 * retransmission.
+	 *
+	 * We use a barrier here so that the call number and abort code can be
+	 * read without needing to take a lock.
+	 *
+	 * TODO: Make the incoming packet handler check this and handle
+	 * terminal retransmission without requiring access to the call.
+	 */
+	if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		_debug("exposed %u,%u", call->call_id, call->abort_code);
+		__rxrpc_disconnect_call(conn, call);
+
+		if (test_and_clear_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) {
+			trace_rxrpc_client(conn, channel, rxrpc_client_to_active);
+			bundle->try_upgrade = false;
+			if (may_reuse)
+				rxrpc_activate_channels(bundle);
+		}
+	}
+
+	/* See if we can pass the channel directly to another call. */
+	if (may_reuse && !list_empty(&bundle->waiting_calls)) {
+		trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass);
+		rxrpc_activate_one_channel(conn, channel);
+		return;
+	}
+
+	/* Schedule the final ACK to be transmitted in a short while so that it
+	 * can be skipped if we find a follow-on call.  The first DATA packet
+	 * of the follow on call will implicitly ACK this call.
+	 */
+	if (call->completion == RXRPC_CALL_SUCCEEDED &&
+	    test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		unsigned long final_ack_at = jiffies + 2;
+
+		chan->final_ack_at = final_ack_at;
+		smp_wmb(); /* vs rxrpc_process_delayed_final_acks() */
+		set_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags);
+		rxrpc_reduce_conn_timer(conn, final_ack_at);
+	}
+
+	/* Deactivate the channel. */
+	chan->call = NULL;
+	set_bit(conn->bundle_shift + channel, &conn->bundle->avail_chans);
+	conn->act_chans	&= ~(1 << channel);
+
+	/* If no channels remain active, then put the connection on the idle
+	 * list for a short while.  Give it a ref to stop it going away if it
+	 * becomes unbundled.
+	 */
+	if (!conn->act_chans) {
+		trace_rxrpc_client(conn, channel, rxrpc_client_to_idle);
+		conn->idle_timestamp = jiffies;
+
+		rxrpc_get_connection(conn, rxrpc_conn_get_idle);
+		list_move_tail(&conn->cache_link, &local->idle_client_conns);
+
+		rxrpc_set_client_reap_timer(local);
+	}
+}
+
+/*
+ * Remove a connection from a bundle.
+ */
+static void rxrpc_unbundle_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_bundle *bundle = conn->bundle;
+	unsigned int bindex;
+	int i;
+
+	_enter("C=%x", conn->debug_id);
+
+	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+		rxrpc_process_delayed_final_acks(conn, true);
+
+	bindex = conn->bundle_shift / RXRPC_MAXCALLS;
+	if (bundle->conns[bindex] == conn) {
+		_debug("clear slot %u", bindex);
+		bundle->conns[bindex] = NULL;
+		bundle->conn_ids[bindex] = 0;
+		for (i = 0; i < RXRPC_MAXCALLS; i++)
+			clear_bit(conn->bundle_shift + i, &bundle->avail_chans);
+		rxrpc_put_client_connection_id(bundle->local, conn);
+		rxrpc_deactivate_bundle(bundle);
+		rxrpc_put_connection(conn, rxrpc_conn_put_unbundle);
+	}
+}
+
+/*
+ * Drop the active count on a bundle.
+ */
+void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle)
+{
+	struct rxrpc_local *local;
+	bool need_put = false;
+
+	if (!bundle)
+		return;
+
+	local = bundle->local;
+	if (atomic_dec_and_lock(&bundle->active, &local->client_bundles_lock)) {
+		if (!bundle->exclusive) {
+			_debug("erase bundle");
+			rb_erase(&bundle->local_node, &local->client_bundles);
+			need_put = true;
+		}
+
+		spin_unlock(&local->client_bundles_lock);
+		if (need_put)
+			rxrpc_put_bundle(bundle, rxrpc_bundle_put_discard);
+	}
+}
+
+/*
+ * Clean up a dead client connection.
+ */
+void rxrpc_kill_client_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_local *local = conn->local;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	_enter("C=%x", conn->debug_id);
+
+	trace_rxrpc_client(conn, -1, rxrpc_client_cleanup);
+	atomic_dec(&rxnet->nr_client_conns);
+
+	rxrpc_put_client_connection_id(local, conn);
+}
+
+/*
+ * Discard expired client connections from the idle list.  Each conn in the
+ * idle list has been exposed and holds an extra ref because of that.
+ *
+ * This may be called from conn setup or from a work item so cannot be
+ * considered non-reentrant.
+ */
+void rxrpc_discard_expired_client_conns(struct rxrpc_local *local)
+{
+	struct rxrpc_connection *conn;
+	unsigned long expiry, conn_expires_at, now;
+	unsigned int nr_conns;
+
+	_enter("");
+
+	/* We keep an estimate of what the number of conns ought to be after
+	 * we've discarded some so that we don't overdo the discarding.
+	 */
+	nr_conns = atomic_read(&local->rxnet->nr_client_conns);
+
+next:
+	conn = list_first_entry_or_null(&local->idle_client_conns,
+					struct rxrpc_connection, cache_link);
+	if (!conn)
+		return;
+
+	if (!local->kill_all_client_conns) {
+		/* If the number of connections is over the reap limit, we
+		 * expedite discard by reducing the expiry timeout.  We must,
+		 * however, have at least a short grace period to be able to do
+		 * final-ACK or ABORT retransmission.
+		 */
+		expiry = rxrpc_conn_idle_client_expiry;
+		if (nr_conns > rxrpc_reap_client_connections)
+			expiry = rxrpc_conn_idle_client_fast_expiry;
+		if (conn->local->service_closed)
+			expiry = rxrpc_closed_conn_expiry * HZ;
+
+		conn_expires_at = conn->idle_timestamp + expiry;
+
+		now = jiffies;
+		if (time_after(conn_expires_at, now))
+			goto not_yet_expired;
+	}
+
+	atomic_dec(&conn->active);
+	trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+	list_del_init(&conn->cache_link);
+
+	rxrpc_unbundle_conn(conn);
+	/* Drop the ->cache_link ref */
+	rxrpc_put_connection(conn, rxrpc_conn_put_discard_idle);
+
+	nr_conns--;
+	goto next;
+
+not_yet_expired:
+	/* The connection at the front of the queue hasn't yet expired, so
+	 * schedule the work item for that point if we discarded something.
+	 *
+	 * We don't worry if the work item is already scheduled - it can look
+	 * after rescheduling itself at a later time.  We could cancel it, but
+	 * then things get messier.
+	 */
+	_debug("not yet");
+	if (!local->kill_all_client_conns)
+		timer_reduce(&local->client_conn_reap_timer, conn_expires_at);
+
+	_leave("");
+}
+
+/*
+ * Clean up the client connections on a local endpoint.
+ */
+void rxrpc_clean_up_local_conns(struct rxrpc_local *local)
+{
+	struct rxrpc_connection *conn;
+
+	_enter("");
+
+	local->kill_all_client_conns = true;
+
+	timer_delete_sync(&local->client_conn_reap_timer);
+
+	while ((conn = list_first_entry_or_null(&local->idle_client_conns,
+						struct rxrpc_connection, cache_link))) {
+		list_del_init(&conn->cache_link);
+		atomic_dec(&conn->active);
+		trace_rxrpc_client(conn, -1, rxrpc_client_discard);
+		rxrpc_unbundle_conn(conn);
+		rxrpc_put_connection(conn, rxrpc_conn_put_local_dead);
+	}
+
+	_leave(" [culled]");
+}
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
new file mode 100644
index 000000000..611c790bc
--- /dev/null
+++ b/net/rxrpc/conn_event.c
@@ -0,0 +1,600 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* connection-level event handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+/*
+ * Set the completion state on an aborted connection.
+ */
+static bool rxrpc_set_conn_aborted(struct rxrpc_connection *conn,
+				   s32 abort_code, int err,
+				   enum rxrpc_call_completion compl)
+{
+	bool aborted = false;
+
+	if (conn->state != RXRPC_CONN_ABORTED) {
+		spin_lock_irq(&conn->state_lock);
+		if (conn->state != RXRPC_CONN_ABORTED) {
+			conn->abort_code = abort_code;
+			conn->error	 = err;
+			conn->completion = compl;
+			/* Order the abort info before the state change. */
+			smp_store_release(&conn->state, RXRPC_CONN_ABORTED);
+			set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+			set_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events);
+			aborted = true;
+		}
+		spin_unlock_irq(&conn->state_lock);
+	}
+
+	return aborted;
+}
+
+/*
+ * Mark a socket buffer to indicate that the connection it's on should be aborted.
+ */
+int rxrpc_abort_conn(struct rxrpc_connection *conn, struct sk_buff *skb,
+		     s32 abort_code, int err, enum rxrpc_abort_reason why)
+{
+
+	u32 cid = conn->proto.cid, call = 0, seq = 0;
+
+	if (skb) {
+		struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+		cid  = sp->hdr.cid;
+		call = sp->hdr.callNumber;
+		seq  = sp->hdr.seq;
+	}
+
+	if (rxrpc_set_conn_aborted(conn, abort_code, err,
+				   RXRPC_CALL_LOCALLY_ABORTED)) {
+		trace_rxrpc_abort(0, why, cid, call, seq, abort_code, err);
+		rxrpc_poke_conn(conn, rxrpc_conn_get_poke_abort);
+	}
+	return -EPROTO;
+}
+
+/*
+ * Mark a connection as being remotely aborted.
+ */
+static void rxrpc_input_conn_abort(struct rxrpc_connection *conn,
+				   struct sk_buff *skb)
+{
+	trace_rxrpc_rx_conn_abort(conn, skb);
+	rxrpc_set_conn_aborted(conn, skb->priority, -ECONNABORTED,
+			       RXRPC_CALL_REMOTELY_ABORTED);
+}
+
+/*
+ * Retransmit terminal ACK or ABORT of the previous call.
+ */
+void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
+				struct sk_buff *skb,
+				unsigned int channel)
+{
+	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
+	struct rxrpc_channel *chan;
+	struct msghdr msg;
+	struct kvec iov[3];
+	struct {
+		struct rxrpc_wire_header whdr;
+		union {
+			__be32 abort_code;
+			struct rxrpc_ackpacket ack;
+		};
+	} __attribute__((packed)) pkt;
+	struct rxrpc_acktrailer trailer;
+	size_t len;
+	int ret, ioc;
+	u32 serial, max_mtu, if_mtu, call_id, padding;
+
+	_enter("%d", conn->debug_id);
+
+	if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
+		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+				  &pkt.ack, sizeof(pkt.ack)) < 0)
+			return;
+		if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
+			return;
+	}
+
+	chan = &conn->channels[channel];
+
+	/* If the last call got moved on whilst we were waiting to run, just
+	 * ignore this packet.
+	 */
+	call_id = chan->last_call;
+	if (skb && call_id != sp->hdr.callNumber)
+		return;
+
+	msg.msg_name	= &conn->peer->srx.transport;
+	msg.msg_namelen	= conn->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	iov[0].iov_base	= &pkt;
+	iov[0].iov_len	= sizeof(pkt.whdr);
+	iov[1].iov_base	= &padding;
+	iov[1].iov_len	= 3;
+	iov[2].iov_base	= &trailer;
+	iov[2].iov_len	= sizeof(trailer);
+
+	serial = rxrpc_get_next_serial(conn);
+
+	pkt.whdr.epoch		= htonl(conn->proto.epoch);
+	pkt.whdr.cid		= htonl(conn->proto.cid | channel);
+	pkt.whdr.callNumber	= htonl(call_id);
+	pkt.whdr.serial		= htonl(serial);
+	pkt.whdr.seq		= 0;
+	pkt.whdr.type		= chan->last_type;
+	pkt.whdr.flags		= conn->out_clientflag;
+	pkt.whdr.userStatus	= 0;
+	pkt.whdr.securityIndex	= conn->security_ix;
+	pkt.whdr._rsvd		= 0;
+	pkt.whdr.serviceId	= htons(conn->service_id);
+
+	len = sizeof(pkt.whdr);
+	switch (chan->last_type) {
+	case RXRPC_PACKET_TYPE_ABORT:
+		pkt.abort_code	= htonl(chan->last_abort);
+		iov[0].iov_len += sizeof(pkt.abort_code);
+		len += sizeof(pkt.abort_code);
+		ioc = 1;
+		break;
+
+	case RXRPC_PACKET_TYPE_ACK:
+		if_mtu = conn->peer->if_mtu - conn->peer->hdrsize;
+		if (conn->peer->ackr_adv_pmtud) {
+			max_mtu = umax(conn->peer->max_data, rxrpc_rx_mtu);
+		} else {
+			if_mtu = umin(1444, if_mtu);
+			max_mtu = if_mtu;
+		}
+		pkt.ack.bufferSpace	= 0;
+		pkt.ack.maxSkew		= htons(skb ? skb->priority : 0);
+		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
+		pkt.ack.previousPacket	= htonl(chan->last_seq);
+		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
+		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
+		pkt.ack.nAcks		= 0;
+		trailer.maxMTU		= htonl(max_mtu);
+		trailer.ifMTU		= htonl(if_mtu);
+		trailer.rwind		= htonl(rxrpc_rx_window_size);
+		trailer.jumbo_max	= 0;
+		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
+		padding			= 0;
+		iov[0].iov_len += sizeof(pkt.ack);
+		len += sizeof(pkt.ack) + 3 + sizeof(trailer);
+		ioc = 3;
+
+		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
+				   ntohl(pkt.ack.firstPacket),
+				   ntohl(pkt.ack.serial),
+				   pkt.ack.reason, 0, rxrpc_rx_window_size,
+				   rxrpc_propose_ack_retransmit);
+		break;
+
+	default:
+		return;
+	}
+
+	ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
+	rxrpc_peer_mark_tx(conn->peer);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
+				    rxrpc_tx_point_call_final_resend);
+	else
+		trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
+				      rxrpc_tx_point_call_final_resend);
+
+	_leave("");
+}
+
+/*
+ * pass a connection-level abort onto all calls on that connection
+ */
+static void rxrpc_abort_calls(struct rxrpc_connection *conn)
+{
+	struct rxrpc_call *call;
+	int i;
+
+	_enter("{%d},%x", conn->debug_id, conn->abort_code);
+
+	for (i = 0; i < RXRPC_MAXCALLS; i++) {
+		call = conn->channels[i].call;
+		if (call) {
+			rxrpc_see_call(call, rxrpc_call_see_conn_abort);
+			rxrpc_set_call_completion(call,
+						  conn->completion,
+						  conn->abort_code,
+						  conn->error);
+			rxrpc_poke_call(call, rxrpc_call_poke_conn_abort);
+		}
+	}
+
+	_leave("");
+}
+
+/*
+ * mark a call as being on a now-secured channel
+ * - must be called with BH's disabled.
+ */
+static void rxrpc_call_is_secure(struct rxrpc_call *call)
+{
+	if (call && __test_and_clear_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags))
+		rxrpc_notify_socket(call);
+}
+
+static int rxrpc_verify_response(struct rxrpc_connection *conn,
+				 struct sk_buff *skb)
+{
+	unsigned int len = skb->len - sizeof(struct rxrpc_wire_header);
+	void *buffer;
+	int ret;
+
+	buffer = kmalloc(len, GFP_NOFS);
+	if (!buffer)
+		return -ENOMEM;
+
+	ret = skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), buffer, len);
+	if (ret < 0)
+		goto out;
+
+	ret = conn->security->verify_response(conn, skb, buffer, len);
+
+out:
+	kfree(buffer);
+	return ret;
+}
+
+/*
+ * connection-level Rx packet processor
+ */
+static int rxrpc_process_event(struct rxrpc_connection *conn,
+			       struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	bool secured = false;
+	int ret;
+
+	if (conn->state == RXRPC_CONN_ABORTED)
+		return -ECONNABORTED;
+
+	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		ret = conn->security->respond_to_challenge(conn, skb);
+		sp->chall.conn = NULL;
+		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
+		return ret;
+
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		spin_lock_irq(&conn->state_lock);
+		if (conn->state != RXRPC_CONN_SERVICE_CHALLENGING) {
+			spin_unlock_irq(&conn->state_lock);
+			return 0;
+		}
+		spin_unlock_irq(&conn->state_lock);
+
+		ret = rxrpc_verify_response(conn, skb);
+		if (ret < 0)
+			return ret;
+
+		ret = conn->security->init_connection_security(
+			conn, conn->key->payload.data[0]);
+		if (ret < 0)
+			return ret;
+
+		spin_lock_irq(&conn->state_lock);
+		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
+			conn->state = RXRPC_CONN_SERVICE;
+			secured = true;
+		}
+		spin_unlock_irq(&conn->state_lock);
+
+		if (secured) {
+			/* Offload call state flipping to the I/O thread.  As
+			 * we've already received the packet, put it on the
+			 * front of the queue.
+			 */
+			sp->poke_conn = rxrpc_get_connection(
+				conn, rxrpc_conn_get_poke_secured);
+			skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
+			rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
+			skb_queue_head(&conn->local->rx_queue, skb);
+			rxrpc_wake_up_io_thread(conn->local);
+		}
+		return 0;
+
+	default:
+		WARN_ON_ONCE(1);
+		return -EPROTO;
+	}
+}
+
+/*
+ * set up security and issue a challenge
+ */
+static void rxrpc_secure_connection(struct rxrpc_connection *conn)
+{
+	if (conn->security->issue_challenge(conn) < 0)
+		rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
+				 rxrpc_abort_nomem);
+}
+
+/*
+ * Process delayed final ACKs that we haven't subsumed into a subsequent call.
+ */
+void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
+{
+	unsigned long j = jiffies, next_j;
+	unsigned int channel;
+	bool set;
+
+again:
+	next_j = j + LONG_MAX;
+	set = false;
+	for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
+		struct rxrpc_channel *chan = &conn->channels[channel];
+		unsigned long ack_at;
+
+		if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
+			continue;
+
+		ack_at = chan->final_ack_at;
+		if (time_before(j, ack_at) && !force) {
+			if (time_before(ack_at, next_j)) {
+				next_j = ack_at;
+				set = true;
+			}
+			continue;
+		}
+
+		if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
+				       &conn->flags))
+			rxrpc_conn_retransmit_call(conn, NULL, channel);
+	}
+
+	j = jiffies;
+	if (time_before_eq(next_j, j))
+		goto again;
+	if (set)
+		rxrpc_reduce_conn_timer(conn, next_j);
+}
+
+/*
+ * connection-level event processor
+ */
+static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
+{
+	struct sk_buff *skb;
+
+	if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
+		rxrpc_secure_connection(conn);
+
+	/* go through the conn-level event packets, releasing the ref on this
+	 * connection that each one has when we've finished with it */
+	while ((skb = skb_dequeue(&conn->rx_queue))) {
+		rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
+		rxrpc_process_event(conn, skb);
+		rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
+	}
+}
+
+void rxrpc_process_connection(struct work_struct *work)
+{
+	struct rxrpc_connection *conn =
+		container_of(work, struct rxrpc_connection, processor);
+
+	rxrpc_see_connection(conn, rxrpc_conn_see_work);
+
+	if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
+		rxrpc_do_process_connection(conn);
+		rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
+	}
+}
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses, some aborts and call terminal packet
+ *   retransmission.
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+				      struct sk_buff *skb)
+{
+	_enter("%p,%p", conn, skb);
+
+	rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
+	skb_queue_tail(&conn->rx_queue, skb);
+	rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
+}
+
+/*
+ * Post a CHALLENGE packet to the socket of one of a connection's calls so that
+ * it can get application data to include in the packet, possibly querying
+ * userspace.
+ */
+static bool rxrpc_post_challenge(struct rxrpc_connection *conn,
+				 struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_call *call = NULL;
+	struct rxrpc_sock *rx;
+	bool respond = false, queued = false;
+
+	sp->chall.conn =
+		rxrpc_get_connection(conn, rxrpc_conn_get_challenge_input);
+
+	if (!conn->security->challenge_to_recvmsg) {
+		rxrpc_post_packet_to_conn(conn, skb);
+		return true;
+	}
+
+	rcu_read_lock();
+
+	for (int i = 0; i < ARRAY_SIZE(conn->channels); i++) {
+		if (conn->channels[i].call) {
+			call = conn->channels[i].call;
+			rx = rcu_dereference(call->socket);
+			if (!rx) {
+				call = NULL;
+				continue;
+			}
+
+			respond = true;
+			if (test_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags))
+				break;
+			call = NULL;
+		}
+	}
+
+	if (!respond) {
+		rcu_read_unlock();
+		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
+		sp->chall.conn = NULL;
+		return false;
+	}
+
+	if (call)
+		queued = rxrpc_notify_socket_oob(call, skb);
+	rcu_read_unlock();
+	if (call && !queued) {
+		rxrpc_put_connection(conn, rxrpc_conn_put_challenge_input);
+		sp->chall.conn = NULL;
+		return false;
+	}
+
+	if (!call)
+		rxrpc_post_packet_to_conn(conn, skb);
+	return true;
+}
+
+/*
+ * Input a connection-level packet.
+ */
+bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_BUSY:
+		/* Just ignore BUSY packets for now. */
+		return true;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		if (rxrpc_is_conn_aborted(conn))
+			return true;
+		rxrpc_input_conn_abort(conn, skb);
+		rxrpc_abort_calls(conn);
+		return true;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		rxrpc_see_skb(skb, rxrpc_skb_see_oob_challenge);
+		if (rxrpc_is_conn_aborted(conn)) {
+			if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
+				rxrpc_send_conn_abort(conn);
+			return true;
+		}
+		if (!conn->security->validate_challenge(conn, skb))
+			return false;
+		return rxrpc_post_challenge(conn, skb);
+
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		if (rxrpc_is_conn_aborted(conn)) {
+			if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
+				rxrpc_send_conn_abort(conn);
+			return true;
+		}
+		rxrpc_post_packet_to_conn(conn, skb);
+		return true;
+
+	default:
+		WARN_ON_ONCE(1);
+		return true;
+	}
+}
+
+/*
+ * Input a connection event.
+ */
+void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
+{
+	unsigned int loop;
+
+	if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
+		rxrpc_abort_calls(conn);
+
+	if (conn->tx_response) {
+		struct sk_buff *skb;
+
+		spin_lock_irq(&conn->local->lock);
+		skb = conn->tx_response;
+		conn->tx_response = NULL;
+		spin_unlock_irq(&conn->local->lock);
+
+		if (conn->state != RXRPC_CONN_ABORTED)
+			rxrpc_send_response(conn, skb);
+		rxrpc_free_skb(skb, rxrpc_skb_put_response);
+	}
+
+	if (skb) {
+		switch (skb->mark) {
+		case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
+			if (conn->state != RXRPC_CONN_SERVICE)
+				break;
+
+			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
+				rxrpc_call_is_secure(conn->channels[loop].call);
+			break;
+		}
+	}
+
+	/* Process delayed ACKs whose time has come. */
+	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
+		rxrpc_process_delayed_final_acks(conn, false);
+}
+
+/*
+ * Post a RESPONSE message to the I/O thread for transmission.
+ */
+void rxrpc_post_response(struct rxrpc_connection *conn, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_local *local = conn->local;
+	struct sk_buff *old;
+
+	_enter("%x", sp->resp.challenge_serial);
+
+	spin_lock_irq(&local->lock);
+	old = conn->tx_response;
+	if (old) {
+		struct rxrpc_skb_priv *osp = rxrpc_skb(old);
+
+		/* Always go with the response to the most recent challenge. */
+		if (after(sp->resp.challenge_serial, osp->resp.challenge_serial))
+			conn->tx_response = skb;
+		else
+			old = skb;
+	} else {
+		conn->tx_response = skb;
+	}
+	spin_unlock_irq(&local->lock);
+	rxrpc_poke_conn(conn, rxrpc_conn_get_poke_response);
+	rxrpc_free_skb(old, rxrpc_skb_put_old_response);
+}
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
new file mode 100644
index 000000000..0ece717db
--- /dev/null
+++ b/net/rxrpc/conn_object.c
@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC virtual connection handler, common bits.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include "ar-internal.h"
+
+/*
+ * Time till a connection expires after last use (in seconds).
+ */
+unsigned int __read_mostly rxrpc_connection_expiry = 10 * 60;
+unsigned int __read_mostly rxrpc_closed_conn_expiry = 10;
+
+static void rxrpc_clean_up_connection(struct work_struct *work);
+static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
+					 unsigned long reap_at);
+
+void rxrpc_poke_conn(struct rxrpc_connection *conn, enum rxrpc_conn_trace why)
+{
+	struct rxrpc_local *local = conn->local;
+	bool busy;
+
+	if (WARN_ON_ONCE(!local))
+		return;
+
+	spin_lock_irq(&local->lock);
+	busy = !list_empty(&conn->attend_link);
+	if (!busy) {
+		rxrpc_get_connection(conn, why);
+		list_add_tail(&conn->attend_link, &local->conn_attend_q);
+	}
+	spin_unlock_irq(&local->lock);
+	rxrpc_wake_up_io_thread(local);
+}
+
+static void rxrpc_connection_timer(struct timer_list *timer)
+{
+	struct rxrpc_connection *conn =
+		container_of(timer, struct rxrpc_connection, timer);
+
+	rxrpc_poke_conn(conn, rxrpc_conn_get_poke_timer);
+}
+
+/*
+ * allocate a new connection
+ */
+struct rxrpc_connection *rxrpc_alloc_connection(struct rxrpc_net *rxnet,
+						gfp_t gfp)
+{
+	struct rxrpc_connection *conn;
+
+	_enter("");
+
+	conn = kzalloc_obj(struct rxrpc_connection, gfp);
+	if (conn) {
+		INIT_LIST_HEAD(&conn->cache_link);
+		timer_setup(&conn->timer, &rxrpc_connection_timer, 0);
+		INIT_WORK(&conn->processor, rxrpc_process_connection);
+		INIT_WORK(&conn->destructor, rxrpc_clean_up_connection);
+		INIT_LIST_HEAD(&conn->proc_link);
+		INIT_LIST_HEAD(&conn->link);
+		INIT_LIST_HEAD(&conn->attend_link);
+		mutex_init(&conn->security_lock);
+		mutex_init(&conn->tx_data_alloc_lock);
+		skb_queue_head_init(&conn->rx_queue);
+		conn->rxnet = rxnet;
+		conn->security = &rxrpc_no_security;
+		rwlock_init(&conn->security_use_lock);
+		spin_lock_init(&conn->state_lock);
+		conn->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		conn->idle_timestamp = jiffies;
+	}
+
+	_leave(" = %p{%d}", conn, conn ? conn->debug_id : 0);
+	return conn;
+}
+
+/*
+ * Look up a connection in the cache by protocol parameters.
+ *
+ * If successful, a pointer to the connection is returned, but no ref is taken.
+ * NULL is returned if there is no match.
+ *
+ * When searching for a service call, if we find a peer but no connection, we
+ * return that through *_peer in case we need to create a new service call.
+ *
+ * The caller must be holding the RCU read lock.
+ */
+struct rxrpc_connection *rxrpc_find_client_connection_rcu(struct rxrpc_local *local,
+							  struct sockaddr_rxrpc *srx,
+							  struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_peer *peer;
+
+	_enter(",%x", sp->hdr.cid & RXRPC_CIDMASK);
+
+	/* Look up client connections by connection ID alone as their
+	 * IDs are unique for this machine.
+	 */
+	conn = idr_find(&local->conn_ids, sp->hdr.cid >> RXRPC_CIDSHIFT);
+	if (!conn || refcount_read(&conn->ref) == 0) {
+		_debug("no conn");
+		goto not_found;
+	}
+
+	if (conn->proto.epoch != sp->hdr.epoch ||
+	    conn->local != local)
+		goto not_found;
+
+	peer = conn->peer;
+	switch (srx->transport.family) {
+	case AF_INET:
+		if (peer->srx.transport.sin.sin_port !=
+		    srx->transport.sin.sin_port)
+			goto not_found;
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		if (peer->srx.transport.sin6.sin6_port !=
+		    srx->transport.sin6.sin6_port)
+			goto not_found;
+		break;
+#endif
+	default:
+		BUG();
+	}
+
+	_leave(" = %p", conn);
+	return conn;
+
+not_found:
+	_leave(" = NULL");
+	return NULL;
+}
+
+/*
+ * Disconnect a call and clear any channel it occupies when that call
+ * terminates.  The caller must hold the channel_lock and must release the
+ * call's ref on the connection.
+ */
+void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
+			     struct rxrpc_call *call)
+{
+	struct rxrpc_channel *chan =
+		&conn->channels[call->cid & RXRPC_CHANNELMASK];
+
+	_enter("%d,%x", conn->debug_id, call->cid);
+
+	if (chan->call == call) {
+		/* Save the result of the call so that we can repeat it if necessary
+		 * through the channel, whilst disposing of the actual call record.
+		 */
+		trace_rxrpc_disconnect_call(call);
+		switch (call->completion) {
+		case RXRPC_CALL_SUCCEEDED:
+			chan->last_seq = call->rx_highest_seq;
+			chan->last_type = RXRPC_PACKET_TYPE_ACK;
+			break;
+		case RXRPC_CALL_LOCALLY_ABORTED:
+			chan->last_abort = call->abort_code;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		default:
+			chan->last_abort = RX_CALL_DEAD;
+			chan->last_type = RXRPC_PACKET_TYPE_ABORT;
+			break;
+		}
+
+		chan->last_call = chan->call_id;
+		chan->call_id = chan->call_counter;
+		chan->call = NULL;
+	}
+
+	_leave("");
+}
+
+/*
+ * Disconnect a call and clear any channel it occupies when that call
+ * terminates.
+ */
+void rxrpc_disconnect_call(struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn = call->conn;
+
+	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+	rxrpc_see_call(call, rxrpc_call_see_disconnected);
+
+	call->peer->cong_ssthresh = call->cong_ssthresh;
+
+	if (!hlist_unhashed(&call->error_link)) {
+		spin_lock_irq(&call->peer->lock);
+		hlist_del_init(&call->error_link);
+		spin_unlock_irq(&call->peer->lock);
+	}
+
+	if (rxrpc_is_client_call(call)) {
+		rxrpc_disconnect_client_call(call->bundle, call);
+	} else {
+		__rxrpc_disconnect_call(conn, call);
+		conn->idle_timestamp = jiffies;
+		if (atomic_dec_and_test(&conn->active))
+			rxrpc_set_service_reap_timer(conn->rxnet,
+						     jiffies + rxrpc_connection_expiry * HZ);
+	}
+
+	rxrpc_put_call(call, rxrpc_call_put_io_thread);
+}
+
+/*
+ * Queue a connection's work processor, getting a ref to pass to the work
+ * queue.
+ */
+void rxrpc_queue_conn(struct rxrpc_connection *conn, enum rxrpc_conn_trace why)
+{
+	if (atomic_read(&conn->active) >= 0 &&
+	    rxrpc_queue_work(&conn->processor))
+		rxrpc_see_connection(conn, why);
+}
+
+/*
+ * Note the re-emergence of a connection.
+ */
+void rxrpc_see_connection(struct rxrpc_connection *conn,
+			  enum rxrpc_conn_trace why)
+{
+	if (conn) {
+		int r = refcount_read(&conn->ref);
+
+		trace_rxrpc_conn(conn->debug_id, r, why);
+	}
+}
+
+/*
+ * Get a ref on a connection.
+ */
+struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *conn,
+					      enum rxrpc_conn_trace why)
+{
+	int r;
+
+	__refcount_inc(&conn->ref, &r);
+	trace_rxrpc_conn(conn->debug_id, r + 1, why);
+	return conn;
+}
+
+/*
+ * Try to get a ref on a connection.
+ */
+struct rxrpc_connection *
+rxrpc_get_connection_maybe(struct rxrpc_connection *conn,
+			   enum rxrpc_conn_trace why)
+{
+	int r;
+
+	if (conn) {
+		if (__refcount_inc_not_zero(&conn->ref, &r))
+			trace_rxrpc_conn(conn->debug_id, r + 1, why);
+		else
+			conn = NULL;
+	}
+	return conn;
+}
+
+/*
+ * Set the service connection reap timer.
+ */
+static void rxrpc_set_service_reap_timer(struct rxrpc_net *rxnet,
+					 unsigned long reap_at)
+{
+	if (rxnet->live)
+		timer_reduce(&rxnet->service_conn_reap_timer, reap_at);
+}
+
+/*
+ * destroy a virtual connection
+ */
+static void rxrpc_rcu_free_connection(struct rcu_head *rcu)
+{
+	struct rxrpc_connection *conn =
+		container_of(rcu, struct rxrpc_connection, rcu);
+	struct rxrpc_net *rxnet = conn->rxnet;
+
+	_enter("{%d,u=%d}", conn->debug_id, refcount_read(&conn->ref));
+
+	trace_rxrpc_conn(conn->debug_id, refcount_read(&conn->ref),
+			 rxrpc_conn_free);
+	kfree(conn);
+
+	if (atomic_dec_and_test(&rxnet->nr_conns))
+		wake_up_var(&rxnet->nr_conns);
+}
+
+/*
+ * Clean up a dead connection.
+ */
+static void rxrpc_clean_up_connection(struct work_struct *work)
+{
+	struct rxrpc_connection *conn =
+		container_of(work, struct rxrpc_connection, destructor);
+	struct rxrpc_net *rxnet = conn->rxnet;
+
+	ASSERT(!conn->channels[0].call &&
+	       !conn->channels[1].call &&
+	       !conn->channels[2].call &&
+	       !conn->channels[3].call);
+	ASSERT(list_empty(&conn->cache_link));
+
+	timer_delete_sync(&conn->timer);
+	cancel_work_sync(&conn->processor); /* Processing may restart the timer */
+	timer_delete_sync(&conn->timer);
+
+	write_lock(&rxnet->conn_lock);
+	list_del_init(&conn->proc_link);
+	write_unlock(&rxnet->conn_lock);
+
+	if (conn->pmtud_probe) {
+		trace_rxrpc_pmtud_lost(conn, 0);
+		conn->peer->pmtud_probing = false;
+		conn->peer->pmtud_pending = true;
+	}
+
+	rxrpc_purge_queue(&conn->rx_queue);
+	rxrpc_free_skb(conn->tx_response, rxrpc_skb_put_response);
+
+	rxrpc_kill_client_conn(conn);
+
+	conn->security->clear(conn);
+	key_put(conn->key);
+	rxrpc_put_bundle(conn->bundle, rxrpc_bundle_put_conn);
+	rxrpc_put_peer(conn->peer, rxrpc_peer_put_conn);
+	rxrpc_put_local(conn->local, rxrpc_local_put_kill_conn);
+
+	/* Drain the Rx queue.  Note that even though we've unpublished, an
+	 * incoming packet could still be being added to our Rx queue, so we
+	 * will need to drain it again in the RCU cleanup handler.
+	 */
+	rxrpc_purge_queue(&conn->rx_queue);
+
+	page_frag_cache_drain(&conn->tx_data_alloc);
+	call_rcu(&conn->rcu, rxrpc_rcu_free_connection);
+}
+
+/*
+ * Drop a ref on a connection.
+ */
+void rxrpc_put_connection(struct rxrpc_connection *conn,
+			  enum rxrpc_conn_trace why)
+{
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (!conn)
+		return;
+
+	debug_id = conn->debug_id;
+	dead = __refcount_dec_and_test(&conn->ref, &r);
+	trace_rxrpc_conn(debug_id, r - 1, why);
+	if (dead) {
+		timer_delete(&conn->timer);
+		cancel_work(&conn->processor);
+
+		if (in_softirq() || work_busy(&conn->processor) ||
+		    timer_pending(&conn->timer))
+			/* Can't use the rxrpc workqueue as we need to cancel/flush
+			 * something that may be running/waiting there.
+			 */
+			schedule_work(&conn->destructor);
+		else
+			rxrpc_clean_up_connection(&conn->destructor);
+	}
+}
+
+/*
+ * reap dead service connections
+ */
+void rxrpc_service_connection_reaper(struct work_struct *work)
+{
+	struct rxrpc_connection *conn, *_p;
+	struct rxrpc_net *rxnet =
+		container_of(work, struct rxrpc_net, service_conn_reaper);
+	unsigned long expire_at, earliest, idle_timestamp, now;
+	int active;
+
+	LIST_HEAD(graveyard);
+
+	_enter("");
+
+	now = jiffies;
+	earliest = now + MAX_JIFFY_OFFSET;
+
+	write_lock(&rxnet->conn_lock);
+	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
+		ASSERTCMP(atomic_read(&conn->active), >=, 0);
+		if (likely(atomic_read(&conn->active) > 0))
+			continue;
+		if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
+			continue;
+
+		if (rxnet->live && !conn->local->dead) {
+			idle_timestamp = READ_ONCE(conn->idle_timestamp);
+			expire_at = idle_timestamp + rxrpc_connection_expiry * HZ;
+			if (conn->local->service_closed)
+				expire_at = idle_timestamp + rxrpc_closed_conn_expiry * HZ;
+
+			_debug("reap CONN %d { a=%d,t=%ld }",
+			       conn->debug_id, atomic_read(&conn->active),
+			       (long)expire_at - (long)now);
+
+			if (time_before(now, expire_at)) {
+				if (time_before(expire_at, earliest))
+					earliest = expire_at;
+				continue;
+			}
+		}
+
+		/* The activity count sits at 0 whilst the conn is unused on
+		 * the list; we reduce that to -1 to make the conn unavailable.
+		 */
+		active = 0;
+		if (!atomic_try_cmpxchg(&conn->active, &active, -1))
+			continue;
+		rxrpc_see_connection(conn, rxrpc_conn_see_reap_service);
+
+		if (rxrpc_conn_is_client(conn))
+			BUG();
+		else
+			rxrpc_unpublish_service_conn(conn);
+
+		list_move_tail(&conn->link, &graveyard);
+	}
+	write_unlock(&rxnet->conn_lock);
+
+	if (earliest != now + MAX_JIFFY_OFFSET) {
+		_debug("reschedule reaper %ld", (long)earliest - (long)now);
+		ASSERT(time_after(earliest, now));
+		rxrpc_set_service_reap_timer(rxnet, earliest);
+	}
+
+	while (!list_empty(&graveyard)) {
+		conn = list_entry(graveyard.next, struct rxrpc_connection,
+				  link);
+		list_del_init(&conn->link);
+
+		ASSERTCMP(atomic_read(&conn->active), ==, -1);
+		rxrpc_put_connection(conn, rxrpc_conn_put_service_reaped);
+	}
+
+	_leave("");
+}
+
+/*
+ * preemptively destroy all the service connection records rather than
+ * waiting for them to time out
+ */
+void rxrpc_destroy_all_connections(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_connection *conn, *_p;
+	bool leak = false;
+
+	_enter("");
+
+	atomic_dec(&rxnet->nr_conns);
+
+	timer_delete_sync(&rxnet->service_conn_reap_timer);
+	rxrpc_queue_work(&rxnet->service_conn_reaper);
+	flush_workqueue(rxrpc_workqueue);
+
+	write_lock(&rxnet->conn_lock);
+	list_for_each_entry_safe(conn, _p, &rxnet->service_conns, link) {
+		pr_err("AF_RXRPC: Leaked conn %p {%d}\n",
+		       conn, refcount_read(&conn->ref));
+		leak = true;
+	}
+	write_unlock(&rxnet->conn_lock);
+	BUG_ON(leak);
+
+	ASSERT(list_empty(&rxnet->conn_proc_list));
+
+	/* We need to wait for the connections to be destroyed by RCU as they
+	 * pin things that we still need to get rid of.
+	 */
+	wait_var_event(&rxnet->nr_conns, !atomic_read(&rxnet->nr_conns));
+	_leave("");
+}
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
new file mode 100644
index 000000000..39c908a3c
--- /dev/null
+++ b/net/rxrpc/conn_service.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Service connection management
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/slab.h>
+#include "ar-internal.h"
+
+/*
+ * Find a service connection under RCU conditions.
+ *
+ * We could use a hash table, but that is subject to bucket stuffing by an
+ * attacker as the client gets to pick the epoch and cid values and would know
+ * the hash function.  So, instead, we use a hash table for the peer and from
+ * that an rbtree to find the service connection.  Under ordinary circumstances
+ * it might be slower than a large hash table, but it is at least limited in
+ * depth.
+ */
+struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer,
+						     struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn = NULL;
+	struct rxrpc_conn_proto k;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rb_node *p;
+	unsigned int seq = 1;
+
+	k.epoch	= sp->hdr.epoch;
+	k.cid	= sp->hdr.cid & RXRPC_CIDMASK;
+
+	do {
+		/* Unfortunately, rbtree walking doesn't give reliable results
+		 * under just the RCU read lock, so we have to check for
+		 * changes.
+		 */
+		seq++; /* 2 on the 1st/lockless path, otherwise odd */
+		read_seqbegin_or_lock(&peer->service_conn_lock, &seq);
+
+		p = rcu_dereference_raw(peer->service_conns.rb_node);
+		while (p) {
+			conn = rb_entry(p, struct rxrpc_connection, service_node);
+
+			if (conn->proto.index_key < k.index_key)
+				p = rcu_dereference_raw(p->rb_left);
+			else if (conn->proto.index_key > k.index_key)
+				p = rcu_dereference_raw(p->rb_right);
+			else
+				break;
+			conn = NULL;
+		}
+	} while (need_seqretry(&peer->service_conn_lock, seq));
+
+	done_seqretry(&peer->service_conn_lock, seq);
+	_leave(" = %d", conn ? conn->debug_id : -1);
+	return conn;
+}
+
+/*
+ * Insert a service connection into a peer's tree, thereby making it a target
+ * for incoming packets.
+ */
+static void rxrpc_publish_service_conn(struct rxrpc_peer *peer,
+				       struct rxrpc_connection *conn)
+{
+	struct rxrpc_connection *cursor = NULL;
+	struct rxrpc_conn_proto k = conn->proto;
+	struct rb_node **pp, *parent;
+
+	write_seqlock(&peer->service_conn_lock);
+
+	pp = &peer->service_conns.rb_node;
+	parent = NULL;
+	while (*pp) {
+		parent = *pp;
+		cursor = rb_entry(parent,
+				  struct rxrpc_connection, service_node);
+
+		if (cursor->proto.index_key < k.index_key)
+			pp = &(*pp)->rb_left;
+		else if (cursor->proto.index_key > k.index_key)
+			pp = &(*pp)->rb_right;
+		else
+			goto found_extant_conn;
+	}
+
+	rb_link_node_rcu(&conn->service_node, parent, pp);
+	rb_insert_color(&conn->service_node, &peer->service_conns);
+conn_published:
+	set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags);
+	write_sequnlock(&peer->service_conn_lock);
+	_leave(" = %d [new]", conn->debug_id);
+	return;
+
+found_extant_conn:
+	if (refcount_read(&cursor->ref) == 0)
+		goto replace_old_connection;
+	write_sequnlock(&peer->service_conn_lock);
+	/* We should not be able to get here.  rxrpc_incoming_connection() is
+	 * called in a non-reentrant context, so there can't be a race to
+	 * insert a new connection.
+	 */
+	BUG();
+
+replace_old_connection:
+	/* The old connection is from an outdated epoch. */
+	_debug("replace conn");
+	rb_replace_node_rcu(&cursor->service_node,
+			    &conn->service_node,
+			    &peer->service_conns);
+	clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &cursor->flags);
+	goto conn_published;
+}
+
+/*
+ * Preallocate a service connection.  The connection is placed on the proc and
+ * reap lists so that we don't have to get the lock from BH context.
+ */
+struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *rxnet,
+							   gfp_t gfp)
+{
+	struct rxrpc_connection *conn = rxrpc_alloc_connection(rxnet, gfp);
+
+	if (conn) {
+		/* We maintain an extra ref on the connection whilst it is on
+		 * the rxrpc_connections list.
+		 */
+		conn->state = RXRPC_CONN_SERVICE_PREALLOC;
+		refcount_set(&conn->ref, 2);
+
+		atomic_inc(&rxnet->nr_conns);
+		write_lock(&rxnet->conn_lock);
+		list_add_tail(&conn->link, &rxnet->service_conns);
+		list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+		write_unlock(&rxnet->conn_lock);
+
+		rxrpc_see_connection(conn, rxrpc_conn_new_service);
+	}
+
+	return conn;
+}
+
+/*
+ * Set up an incoming connection.  This is called in BH context with the RCU
+ * read lock held.
+ */
+void rxrpc_new_incoming_connection(struct rxrpc_sock *rx,
+				   struct rxrpc_connection *conn,
+				   const struct rxrpc_security *sec,
+				   struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	_enter("");
+
+	conn->proto.epoch	= sp->hdr.epoch;
+	conn->proto.cid		= sp->hdr.cid & RXRPC_CIDMASK;
+	conn->orig_service_id	= sp->hdr.serviceId;
+	conn->service_id	= sp->hdr.serviceId;
+	conn->security_ix	= sp->hdr.securityIndex;
+	conn->out_clientflag	= 0;
+	conn->security		= sec;
+	if (conn->security_ix)
+		conn->state	= RXRPC_CONN_SERVICE_UNSECURED;
+	else
+		conn->state	= RXRPC_CONN_SERVICE;
+
+	/* See if we should upgrade the service.  This can only happen on the
+	 * first packet on a new connection.  Once done, it applies to all
+	 * subsequent calls on that connection.
+	 */
+	if (sp->hdr.userStatus == RXRPC_USERSTATUS_SERVICE_UPGRADE &&
+	    conn->service_id == rx->service_upgrade.from)
+		conn->service_id = rx->service_upgrade.to;
+
+	atomic_set(&conn->active, 1);
+
+	/* Make the connection a target for incoming packets. */
+	rxrpc_publish_service_conn(conn->peer, conn);
+}
+
+/*
+ * Remove the service connection from the peer's tree, thereby removing it as a
+ * target for incoming packets.
+ */
+void rxrpc_unpublish_service_conn(struct rxrpc_connection *conn)
+{
+	struct rxrpc_peer *peer = conn->peer;
+
+	write_seqlock(&peer->service_conn_lock);
+	if (test_and_clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags))
+		rb_erase(&conn->service_node, &peer->service_conns);
+	write_sequnlock(&peer->service_conn_lock);
+}
diff --git a/net/rxrpc/fcrypt.c b/net/rxrpc/fcrypt.c
new file mode 100644
index 000000000..a919e7598
--- /dev/null
+++ b/net/rxrpc/fcrypt.c
@@ -0,0 +1,352 @@
+/* FCrypt encryption algorithm
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Based on code:
+ *
+ * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <asm/byteorder.h>
+#include <kunit/visibility.h>
+#include <linux/export.h>
+#include <linux/unaligned.h>
+#include "ar-internal.h"
+
+/*
+ * Sboxes for Feistel network derived from
+ * /afs/transarc.com/public/afsps/afs.rel31b.export-src/rxkad/sboxes.h
+ */
+#undef Z
+#define Z(x) cpu_to_be32(x << 3)
+static const __be32 sbox0[256] = {
+	Z(0xea), Z(0x7f), Z(0xb2), Z(0x64), Z(0x9d), Z(0xb0), Z(0xd9), Z(0x11),
+	Z(0xcd), Z(0x86), Z(0x86), Z(0x91), Z(0x0a), Z(0xb2), Z(0x93), Z(0x06),
+	Z(0x0e), Z(0x06), Z(0xd2), Z(0x65), Z(0x73), Z(0xc5), Z(0x28), Z(0x60),
+	Z(0xf2), Z(0x20), Z(0xb5), Z(0x38), Z(0x7e), Z(0xda), Z(0x9f), Z(0xe3),
+	Z(0xd2), Z(0xcf), Z(0xc4), Z(0x3c), Z(0x61), Z(0xff), Z(0x4a), Z(0x4a),
+	Z(0x35), Z(0xac), Z(0xaa), Z(0x5f), Z(0x2b), Z(0xbb), Z(0xbc), Z(0x53),
+	Z(0x4e), Z(0x9d), Z(0x78), Z(0xa3), Z(0xdc), Z(0x09), Z(0x32), Z(0x10),
+	Z(0xc6), Z(0x6f), Z(0x66), Z(0xd6), Z(0xab), Z(0xa9), Z(0xaf), Z(0xfd),
+	Z(0x3b), Z(0x95), Z(0xe8), Z(0x34), Z(0x9a), Z(0x81), Z(0x72), Z(0x80),
+	Z(0x9c), Z(0xf3), Z(0xec), Z(0xda), Z(0x9f), Z(0x26), Z(0x76), Z(0x15),
+	Z(0x3e), Z(0x55), Z(0x4d), Z(0xde), Z(0x84), Z(0xee), Z(0xad), Z(0xc7),
+	Z(0xf1), Z(0x6b), Z(0x3d), Z(0xd3), Z(0x04), Z(0x49), Z(0xaa), Z(0x24),
+	Z(0x0b), Z(0x8a), Z(0x83), Z(0xba), Z(0xfa), Z(0x85), Z(0xa0), Z(0xa8),
+	Z(0xb1), Z(0xd4), Z(0x01), Z(0xd8), Z(0x70), Z(0x64), Z(0xf0), Z(0x51),
+	Z(0xd2), Z(0xc3), Z(0xa7), Z(0x75), Z(0x8c), Z(0xa5), Z(0x64), Z(0xef),
+	Z(0x10), Z(0x4e), Z(0xb7), Z(0xc6), Z(0x61), Z(0x03), Z(0xeb), Z(0x44),
+	Z(0x3d), Z(0xe5), Z(0xb3), Z(0x5b), Z(0xae), Z(0xd5), Z(0xad), Z(0x1d),
+	Z(0xfa), Z(0x5a), Z(0x1e), Z(0x33), Z(0xab), Z(0x93), Z(0xa2), Z(0xb7),
+	Z(0xe7), Z(0xa8), Z(0x45), Z(0xa4), Z(0xcd), Z(0x29), Z(0x63), Z(0x44),
+	Z(0xb6), Z(0x69), Z(0x7e), Z(0x2e), Z(0x62), Z(0x03), Z(0xc8), Z(0xe0),
+	Z(0x17), Z(0xbb), Z(0xc7), Z(0xf3), Z(0x3f), Z(0x36), Z(0xba), Z(0x71),
+	Z(0x8e), Z(0x97), Z(0x65), Z(0x60), Z(0x69), Z(0xb6), Z(0xf6), Z(0xe6),
+	Z(0x6e), Z(0xe0), Z(0x81), Z(0x59), Z(0xe8), Z(0xaf), Z(0xdd), Z(0x95),
+	Z(0x22), Z(0x99), Z(0xfd), Z(0x63), Z(0x19), Z(0x74), Z(0x61), Z(0xb1),
+	Z(0xb6), Z(0x5b), Z(0xae), Z(0x54), Z(0xb3), Z(0x70), Z(0xff), Z(0xc6),
+	Z(0x3b), Z(0x3e), Z(0xc1), Z(0xd7), Z(0xe1), Z(0x0e), Z(0x76), Z(0xe5),
+	Z(0x36), Z(0x4f), Z(0x59), Z(0xc7), Z(0x08), Z(0x6e), Z(0x82), Z(0xa6),
+	Z(0x93), Z(0xc4), Z(0xaa), Z(0x26), Z(0x49), Z(0xe0), Z(0x21), Z(0x64),
+	Z(0x07), Z(0x9f), Z(0x64), Z(0x81), Z(0x9c), Z(0xbf), Z(0xf9), Z(0xd1),
+	Z(0x43), Z(0xf8), Z(0xb6), Z(0xb9), Z(0xf1), Z(0x24), Z(0x75), Z(0x03),
+	Z(0xe4), Z(0xb0), Z(0x99), Z(0x46), Z(0x3d), Z(0xf5), Z(0xd1), Z(0x39),
+	Z(0x72), Z(0x12), Z(0xf6), Z(0xba), Z(0x0c), Z(0x0d), Z(0x42), Z(0x2e)
+};
+
+#undef Z
+#define Z(x) cpu_to_be32(((x & 0x1f) << 27) | (x >> 5))
+static const __be32 sbox1[256] = {
+	Z(0x77), Z(0x14), Z(0xa6), Z(0xfe), Z(0xb2), Z(0x5e), Z(0x8c), Z(0x3e),
+	Z(0x67), Z(0x6c), Z(0xa1), Z(0x0d), Z(0xc2), Z(0xa2), Z(0xc1), Z(0x85),
+	Z(0x6c), Z(0x7b), Z(0x67), Z(0xc6), Z(0x23), Z(0xe3), Z(0xf2), Z(0x89),
+	Z(0x50), Z(0x9c), Z(0x03), Z(0xb7), Z(0x73), Z(0xe6), Z(0xe1), Z(0x39),
+	Z(0x31), Z(0x2c), Z(0x27), Z(0x9f), Z(0xa5), Z(0x69), Z(0x44), Z(0xd6),
+	Z(0x23), Z(0x83), Z(0x98), Z(0x7d), Z(0x3c), Z(0xb4), Z(0x2d), Z(0x99),
+	Z(0x1c), Z(0x1f), Z(0x8c), Z(0x20), Z(0x03), Z(0x7c), Z(0x5f), Z(0xad),
+	Z(0xf4), Z(0xfa), Z(0x95), Z(0xca), Z(0x76), Z(0x44), Z(0xcd), Z(0xb6),
+	Z(0xb8), Z(0xa1), Z(0xa1), Z(0xbe), Z(0x9e), Z(0x54), Z(0x8f), Z(0x0b),
+	Z(0x16), Z(0x74), Z(0x31), Z(0x8a), Z(0x23), Z(0x17), Z(0x04), Z(0xfa),
+	Z(0x79), Z(0x84), Z(0xb1), Z(0xf5), Z(0x13), Z(0xab), Z(0xb5), Z(0x2e),
+	Z(0xaa), Z(0x0c), Z(0x60), Z(0x6b), Z(0x5b), Z(0xc4), Z(0x4b), Z(0xbc),
+	Z(0xe2), Z(0xaf), Z(0x45), Z(0x73), Z(0xfa), Z(0xc9), Z(0x49), Z(0xcd),
+	Z(0x00), Z(0x92), Z(0x7d), Z(0x97), Z(0x7a), Z(0x18), Z(0x60), Z(0x3d),
+	Z(0xcf), Z(0x5b), Z(0xde), Z(0xc6), Z(0xe2), Z(0xe6), Z(0xbb), Z(0x8b),
+	Z(0x06), Z(0xda), Z(0x08), Z(0x15), Z(0x1b), Z(0x88), Z(0x6a), Z(0x17),
+	Z(0x89), Z(0xd0), Z(0xa9), Z(0xc1), Z(0xc9), Z(0x70), Z(0x6b), Z(0xe5),
+	Z(0x43), Z(0xf4), Z(0x68), Z(0xc8), Z(0xd3), Z(0x84), Z(0x28), Z(0x0a),
+	Z(0x52), Z(0x66), Z(0xa3), Z(0xca), Z(0xf2), Z(0xe3), Z(0x7f), Z(0x7a),
+	Z(0x31), Z(0xf7), Z(0x88), Z(0x94), Z(0x5e), Z(0x9c), Z(0x63), Z(0xd5),
+	Z(0x24), Z(0x66), Z(0xfc), Z(0xb3), Z(0x57), Z(0x25), Z(0xbe), Z(0x89),
+	Z(0x44), Z(0xc4), Z(0xe0), Z(0x8f), Z(0x23), Z(0x3c), Z(0x12), Z(0x52),
+	Z(0xf5), Z(0x1e), Z(0xf4), Z(0xcb), Z(0x18), Z(0x33), Z(0x1f), Z(0xf8),
+	Z(0x69), Z(0x10), Z(0x9d), Z(0xd3), Z(0xf7), Z(0x28), Z(0xf8), Z(0x30),
+	Z(0x05), Z(0x5e), Z(0x32), Z(0xc0), Z(0xd5), Z(0x19), Z(0xbd), Z(0x45),
+	Z(0x8b), Z(0x5b), Z(0xfd), Z(0xbc), Z(0xe2), Z(0x5c), Z(0xa9), Z(0x96),
+	Z(0xef), Z(0x70), Z(0xcf), Z(0xc2), Z(0x2a), Z(0xb3), Z(0x61), Z(0xad),
+	Z(0x80), Z(0x48), Z(0x81), Z(0xb7), Z(0x1d), Z(0x43), Z(0xd9), Z(0xd7),
+	Z(0x45), Z(0xf0), Z(0xd8), Z(0x8a), Z(0x59), Z(0x7c), Z(0x57), Z(0xc1),
+	Z(0x79), Z(0xc7), Z(0x34), Z(0xd6), Z(0x43), Z(0xdf), Z(0xe4), Z(0x78),
+	Z(0x16), Z(0x06), Z(0xda), Z(0x92), Z(0x76), Z(0x51), Z(0xe1), Z(0xd4),
+	Z(0x70), Z(0x03), Z(0xe0), Z(0x2f), Z(0x96), Z(0x91), Z(0x82), Z(0x80)
+};
+
+#undef Z
+#define Z(x) cpu_to_be32(x << 11)
+static const __be32 sbox2[256] = {
+	Z(0xf0), Z(0x37), Z(0x24), Z(0x53), Z(0x2a), Z(0x03), Z(0x83), Z(0x86),
+	Z(0xd1), Z(0xec), Z(0x50), Z(0xf0), Z(0x42), Z(0x78), Z(0x2f), Z(0x6d),
+	Z(0xbf), Z(0x80), Z(0x87), Z(0x27), Z(0x95), Z(0xe2), Z(0xc5), Z(0x5d),
+	Z(0xf9), Z(0x6f), Z(0xdb), Z(0xb4), Z(0x65), Z(0x6e), Z(0xe7), Z(0x24),
+	Z(0xc8), Z(0x1a), Z(0xbb), Z(0x49), Z(0xb5), Z(0x0a), Z(0x7d), Z(0xb9),
+	Z(0xe8), Z(0xdc), Z(0xb7), Z(0xd9), Z(0x45), Z(0x20), Z(0x1b), Z(0xce),
+	Z(0x59), Z(0x9d), Z(0x6b), Z(0xbd), Z(0x0e), Z(0x8f), Z(0xa3), Z(0xa9),
+	Z(0xbc), Z(0x74), Z(0xa6), Z(0xf6), Z(0x7f), Z(0x5f), Z(0xb1), Z(0x68),
+	Z(0x84), Z(0xbc), Z(0xa9), Z(0xfd), Z(0x55), Z(0x50), Z(0xe9), Z(0xb6),
+	Z(0x13), Z(0x5e), Z(0x07), Z(0xb8), Z(0x95), Z(0x02), Z(0xc0), Z(0xd0),
+	Z(0x6a), Z(0x1a), Z(0x85), Z(0xbd), Z(0xb6), Z(0xfd), Z(0xfe), Z(0x17),
+	Z(0x3f), Z(0x09), Z(0xa3), Z(0x8d), Z(0xfb), Z(0xed), Z(0xda), Z(0x1d),
+	Z(0x6d), Z(0x1c), Z(0x6c), Z(0x01), Z(0x5a), Z(0xe5), Z(0x71), Z(0x3e),
+	Z(0x8b), Z(0x6b), Z(0xbe), Z(0x29), Z(0xeb), Z(0x12), Z(0x19), Z(0x34),
+	Z(0xcd), Z(0xb3), Z(0xbd), Z(0x35), Z(0xea), Z(0x4b), Z(0xd5), Z(0xae),
+	Z(0x2a), Z(0x79), Z(0x5a), Z(0xa5), Z(0x32), Z(0x12), Z(0x7b), Z(0xdc),
+	Z(0x2c), Z(0xd0), Z(0x22), Z(0x4b), Z(0xb1), Z(0x85), Z(0x59), Z(0x80),
+	Z(0xc0), Z(0x30), Z(0x9f), Z(0x73), Z(0xd3), Z(0x14), Z(0x48), Z(0x40),
+	Z(0x07), Z(0x2d), Z(0x8f), Z(0x80), Z(0x0f), Z(0xce), Z(0x0b), Z(0x5e),
+	Z(0xb7), Z(0x5e), Z(0xac), Z(0x24), Z(0x94), Z(0x4a), Z(0x18), Z(0x15),
+	Z(0x05), Z(0xe8), Z(0x02), Z(0x77), Z(0xa9), Z(0xc7), Z(0x40), Z(0x45),
+	Z(0x89), Z(0xd1), Z(0xea), Z(0xde), Z(0x0c), Z(0x79), Z(0x2a), Z(0x99),
+	Z(0x6c), Z(0x3e), Z(0x95), Z(0xdd), Z(0x8c), Z(0x7d), Z(0xad), Z(0x6f),
+	Z(0xdc), Z(0xff), Z(0xfd), Z(0x62), Z(0x47), Z(0xb3), Z(0x21), Z(0x8a),
+	Z(0xec), Z(0x8e), Z(0x19), Z(0x18), Z(0xb4), Z(0x6e), Z(0x3d), Z(0xfd),
+	Z(0x74), Z(0x54), Z(0x1e), Z(0x04), Z(0x85), Z(0xd8), Z(0xbc), Z(0x1f),
+	Z(0x56), Z(0xe7), Z(0x3a), Z(0x56), Z(0x67), Z(0xd6), Z(0xc8), Z(0xa5),
+	Z(0xf3), Z(0x8e), Z(0xde), Z(0xae), Z(0x37), Z(0x49), Z(0xb7), Z(0xfa),
+	Z(0xc8), Z(0xf4), Z(0x1f), Z(0xe0), Z(0x2a), Z(0x9b), Z(0x15), Z(0xd1),
+	Z(0x34), Z(0x0e), Z(0xb5), Z(0xe0), Z(0x44), Z(0x78), Z(0x84), Z(0x59),
+	Z(0x56), Z(0x68), Z(0x77), Z(0xa5), Z(0x14), Z(0x06), Z(0xf5), Z(0x2f),
+	Z(0x8c), Z(0x8a), Z(0x73), Z(0x80), Z(0x76), Z(0xb4), Z(0x10), Z(0x86)
+};
+
+#undef Z
+#define Z(x) cpu_to_be32(x << 19)
+static const __be32 sbox3[256] = {
+	Z(0xa9), Z(0x2a), Z(0x48), Z(0x51), Z(0x84), Z(0x7e), Z(0x49), Z(0xe2),
+	Z(0xb5), Z(0xb7), Z(0x42), Z(0x33), Z(0x7d), Z(0x5d), Z(0xa6), Z(0x12),
+	Z(0x44), Z(0x48), Z(0x6d), Z(0x28), Z(0xaa), Z(0x20), Z(0x6d), Z(0x57),
+	Z(0xd6), Z(0x6b), Z(0x5d), Z(0x72), Z(0xf0), Z(0x92), Z(0x5a), Z(0x1b),
+	Z(0x53), Z(0x80), Z(0x24), Z(0x70), Z(0x9a), Z(0xcc), Z(0xa7), Z(0x66),
+	Z(0xa1), Z(0x01), Z(0xa5), Z(0x41), Z(0x97), Z(0x41), Z(0x31), Z(0x82),
+	Z(0xf1), Z(0x14), Z(0xcf), Z(0x53), Z(0x0d), Z(0xa0), Z(0x10), Z(0xcc),
+	Z(0x2a), Z(0x7d), Z(0xd2), Z(0xbf), Z(0x4b), Z(0x1a), Z(0xdb), Z(0x16),
+	Z(0x47), Z(0xf6), Z(0x51), Z(0x36), Z(0xed), Z(0xf3), Z(0xb9), Z(0x1a),
+	Z(0xa7), Z(0xdf), Z(0x29), Z(0x43), Z(0x01), Z(0x54), Z(0x70), Z(0xa4),
+	Z(0xbf), Z(0xd4), Z(0x0b), Z(0x53), Z(0x44), Z(0x60), Z(0x9e), Z(0x23),
+	Z(0xa1), Z(0x18), Z(0x68), Z(0x4f), Z(0xf0), Z(0x2f), Z(0x82), Z(0xc2),
+	Z(0x2a), Z(0x41), Z(0xb2), Z(0x42), Z(0x0c), Z(0xed), Z(0x0c), Z(0x1d),
+	Z(0x13), Z(0x3a), Z(0x3c), Z(0x6e), Z(0x35), Z(0xdc), Z(0x60), Z(0x65),
+	Z(0x85), Z(0xe9), Z(0x64), Z(0x02), Z(0x9a), Z(0x3f), Z(0x9f), Z(0x87),
+	Z(0x96), Z(0xdf), Z(0xbe), Z(0xf2), Z(0xcb), Z(0xe5), Z(0x6c), Z(0xd4),
+	Z(0x5a), Z(0x83), Z(0xbf), Z(0x92), Z(0x1b), Z(0x94), Z(0x00), Z(0x42),
+	Z(0xcf), Z(0x4b), Z(0x00), Z(0x75), Z(0xba), Z(0x8f), Z(0x76), Z(0x5f),
+	Z(0x5d), Z(0x3a), Z(0x4d), Z(0x09), Z(0x12), Z(0x08), Z(0x38), Z(0x95),
+	Z(0x17), Z(0xe4), Z(0x01), Z(0x1d), Z(0x4c), Z(0xa9), Z(0xcc), Z(0x85),
+	Z(0x82), Z(0x4c), Z(0x9d), Z(0x2f), Z(0x3b), Z(0x66), Z(0xa1), Z(0x34),
+	Z(0x10), Z(0xcd), Z(0x59), Z(0x89), Z(0xa5), Z(0x31), Z(0xcf), Z(0x05),
+	Z(0xc8), Z(0x84), Z(0xfa), Z(0xc7), Z(0xba), Z(0x4e), Z(0x8b), Z(0x1a),
+	Z(0x19), Z(0xf1), Z(0xa1), Z(0x3b), Z(0x18), Z(0x12), Z(0x17), Z(0xb0),
+	Z(0x98), Z(0x8d), Z(0x0b), Z(0x23), Z(0xc3), Z(0x3a), Z(0x2d), Z(0x20),
+	Z(0xdf), Z(0x13), Z(0xa0), Z(0xa8), Z(0x4c), Z(0x0d), Z(0x6c), Z(0x2f),
+	Z(0x47), Z(0x13), Z(0x13), Z(0x52), Z(0x1f), Z(0x2d), Z(0xf5), Z(0x79),
+	Z(0x3d), Z(0xa2), Z(0x54), Z(0xbd), Z(0x69), Z(0xc8), Z(0x6b), Z(0xf3),
+	Z(0x05), Z(0x28), Z(0xf1), Z(0x16), Z(0x46), Z(0x40), Z(0xb0), Z(0x11),
+	Z(0xd3), Z(0xb7), Z(0x95), Z(0x49), Z(0xcf), Z(0xc3), Z(0x1d), Z(0x8f),
+	Z(0xd8), Z(0xe1), Z(0x73), Z(0xdb), Z(0xad), Z(0xc8), Z(0xc9), Z(0xa9),
+	Z(0xa1), Z(0xc2), Z(0xc5), Z(0xe3), Z(0xba), Z(0xfc), Z(0x0e), Z(0x25)
+};
+
+union fcrypt_block {
+	__be64 a;
+	struct {
+		__be32 l, r;
+	};
+};
+
+#define F_ENCRYPT(R, L, sched)                                       \
+	do {                                                         \
+		union lc4 {                                          \
+			__be32 l;                                    \
+			u8 c[4];                                     \
+		} u;                                                 \
+		u.l = sched ^ R;                                     \
+		L ^= sbox0[u.c[0]] ^ sbox1[u.c[1]] ^ sbox2[u.c[2]] ^ \
+		     sbox3[u.c[3]];                                  \
+	} while (0)
+
+/* Encrypt one block using FCrypt. */
+static __be64 fcrypt_encrypt(const struct fcrypt_key *key, __be64 ptext)
+{
+	union fcrypt_block X = { .a = ptext };
+
+	/* This is a 16 round Feistel network with permutation F_ENCRYPT. */
+	F_ENCRYPT(X.r, X.l, key->sched[0x0]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x1]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x2]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x3]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x4]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x5]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x6]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x7]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x8]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x9]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xa]);
+	F_ENCRYPT(X.l, X.r, key->sched[0xb]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xc]);
+	F_ENCRYPT(X.l, X.r, key->sched[0xd]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xe]);
+	F_ENCRYPT(X.l, X.r, key->sched[0xf]);
+	return X.a;
+}
+
+/* Decrypt one block using FCrypt. */
+static __be64 fcrypt_decrypt(const struct fcrypt_key *key, __be64 ctext)
+{
+	union fcrypt_block X = { .a = ctext };
+
+	/* This is a 16 round Feistel network with permutation F_ENCRYPT. */
+	F_ENCRYPT(X.l, X.r, key->sched[0xf]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xe]);
+	F_ENCRYPT(X.l, X.r, key->sched[0xd]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xc]);
+	F_ENCRYPT(X.l, X.r, key->sched[0xb]);
+	F_ENCRYPT(X.r, X.l, key->sched[0xa]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x9]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x8]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x7]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x6]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x5]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x4]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x3]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x2]);
+	F_ENCRYPT(X.l, X.r, key->sched[0x1]);
+	F_ENCRYPT(X.r, X.l, key->sched[0x0]);
+	return X.a;
+}
+
+/**
+ * fcrypt_preparekey - Prepare a key for FCrypt encryption and decryption
+ * @key: (out) The prepared key
+ * @raw_key: The raw key as an 8-byte array
+ *
+ * This computes the FCrypt key schedule.
+ */
+void fcrypt_preparekey(struct fcrypt_key *key, const u8 raw_key[FCRYPT_BSIZE])
+{
+	u64 k = 0;
+
+	/* Load the 56 non-parity bits of the key.  Discard the parity bits. */
+	for (int i = 0; i < 8; i++)
+		k = (k << 7) | (raw_key[i] >> 1);
+
+	/* Generate the key schedule word for each round. */
+	for (int i = 0; i < FCRYPT_ROUNDS; i++) {
+		key->sched[i] = cpu_to_be32(k);
+		/* Rotate the low 56 bits of 'k' right by 11 bits. */
+		k = (k >> 11) | ((k & ((1 << 11) - 1)) << (56 - 11));
+	}
+}
+EXPORT_SYMBOL_IF_KUNIT(fcrypt_preparekey);
+
+/**
+ * fcrypt_pcbc_encrypt - Encrypt data using FCrypt cipher in PCBC mode
+ * @key: The key
+ * @iv: The 8-byte initialization vector
+ * @src: The source data
+ * @dst: The destination data.  Both in-place and out-of-place are supported.
+ * @nblocks: The number of 8-byte blocks to encrypt
+ *
+ * WARNING: This cipher is insecure.  Not only is the 56-bit key easily
+ * brute-forced, the cipher itself is cryptographically weak and doesn't even
+ * provide the intended 56-bit security level.  It effectively just acts as an
+ * obfuscation algorithm.  It is supported only for backwards compatibility.
+ */
+void fcrypt_pcbc_encrypt(const struct fcrypt_key *key,
+			 const u8 iv[FCRYPT_BSIZE], const void *src, void *dst,
+			 size_t nblocks)
+{
+	__be64 prev = get_unaligned((const __be64 *)iv);
+	const __be64 *src_blocks = src;
+	__be64 *dst_blocks = dst;
+
+	while (nblocks--) {
+		__be64 ptext, ctext;
+
+		ptext = get_unaligned(src_blocks++);
+		ctext = fcrypt_encrypt(key, prev ^ ptext);
+		put_unaligned(ctext, dst_blocks++);
+		prev = ptext ^ ctext;
+	}
+}
+EXPORT_SYMBOL_IF_KUNIT(fcrypt_pcbc_encrypt);
+
+/**
+ * fcrypt_pcbc_decrypt - Decrypt data using FCrypt cipher in PCBC mode
+ * @key: The key
+ * @iv: The 8-byte initialization vector
+ * @src: The source data
+ * @dst: The destination data.  Both in-place and out-of-place are supported.
+ * @nblocks: The number of 8-byte blocks to decrypt
+ */
+void fcrypt_pcbc_decrypt(const struct fcrypt_key *key,
+			 const u8 iv[FCRYPT_BSIZE], const void *src, void *dst,
+			 size_t nblocks)
+{
+	__be64 prev = get_unaligned((const __be64 *)iv);
+	const __be64 *src_blocks = src;
+	__be64 *dst_blocks = dst;
+
+	while (nblocks--) {
+		__be64 ptext, ctext;
+
+		ctext = get_unaligned(src_blocks++);
+		ptext = prev ^ fcrypt_decrypt(key, ctext);
+		put_unaligned(ptext, dst_blocks++);
+		prev = ptext ^ ctext;
+	}
+}
+EXPORT_SYMBOL_IF_KUNIT(fcrypt_pcbc_decrypt);
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
new file mode 100644
index 000000000..73cafe6bf
--- /dev/null
+++ b/net/rxrpc/input.c
@@ -0,0 +1,1332 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Processing of received RxRPC packets
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ar-internal.h"
+
+/* Override priority when generating ACKs for received DATA */
+static const u8 rxrpc_ack_priority[RXRPC_ACK__INVALID] = {
+	[RXRPC_ACK_IDLE]		= 1,
+	[RXRPC_ACK_DELAY]		= 2,
+	[RXRPC_ACK_REQUESTED]		= 3,
+	[RXRPC_ACK_DUPLICATE]		= 4,
+	[RXRPC_ACK_EXCEEDS_WINDOW]	= 5,
+	[RXRPC_ACK_NOSPACE]		= 6,
+	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 7,
+};
+
+static void rxrpc_proto_abort(struct rxrpc_call *call, rxrpc_seq_t seq,
+			      enum rxrpc_abort_reason why)
+{
+	rxrpc_abort_call(call, seq, RX_PROTOCOL_ERROR, -EBADMSG, why);
+}
+
+/*
+ * Do TCP-style congestion management [RFC5681].
+ */
+static void rxrpc_congestion_management(struct rxrpc_call *call,
+					struct rxrpc_ack_summary *summary)
+{
+	summary->change = rxrpc_cong_no_change;
+	summary->in_flight = rxrpc_tx_in_flight(call);
+
+	if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
+		summary->retrans_timeo = true;
+		call->cong_ssthresh = umax(summary->in_flight / 2, 2);
+		call->cong_cwnd = 1;
+		if (call->cong_cwnd >= call->cong_ssthresh &&
+		    call->cong_ca_state == RXRPC_CA_SLOW_START) {
+			call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE;
+			call->cong_tstamp = call->acks_latest_ts;
+			call->cong_cumul_acks = 0;
+		}
+	}
+
+	call->cong_cumul_acks += summary->nr_new_sacks;
+	call->cong_cumul_acks += summary->nr_new_hacks;
+	if (call->cong_cumul_acks > 255)
+		call->cong_cumul_acks = 255;
+
+	switch (call->cong_ca_state) {
+	case RXRPC_CA_SLOW_START:
+		if (call->acks_nr_snacks > 0)
+			goto packet_loss_detected;
+		if (call->cong_cumul_acks > 0)
+			call->cong_cwnd += 1;
+		if (call->cong_cwnd >= call->cong_ssthresh) {
+			call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE;
+			call->cong_tstamp = call->acks_latest_ts;
+		}
+		goto out;
+
+	case RXRPC_CA_CONGEST_AVOIDANCE:
+		if (call->acks_nr_snacks > 0)
+			goto packet_loss_detected;
+
+		/* We analyse the number of packets that get ACK'd per RTT
+		 * period and increase the window if we managed to fill it.
+		 */
+		if (call->rtt_count == 0)
+			goto out;
+		if (ktime_before(call->acks_latest_ts,
+				 ktime_add_us(call->cong_tstamp,
+					      call->srtt_us >> 3)))
+			goto out_no_clear_ca;
+		summary->change = rxrpc_cong_rtt_window_end;
+		call->cong_tstamp = call->acks_latest_ts;
+		if (call->cong_cumul_acks >= call->cong_cwnd)
+			call->cong_cwnd++;
+		goto out;
+
+	case RXRPC_CA_PACKET_LOSS:
+		if (call->acks_nr_snacks == 0)
+			goto resume_normality;
+
+		if (summary->new_low_snack) {
+			summary->change = rxrpc_cong_new_low_nack;
+			call->cong_dup_acks = 1;
+			if (call->cong_extra > 1)
+				call->cong_extra = 1;
+			goto send_extra_data;
+		}
+
+		call->cong_dup_acks++;
+		if (call->cong_dup_acks < 3)
+			goto send_extra_data;
+
+		summary->change = rxrpc_cong_begin_retransmission;
+		call->cong_ca_state = RXRPC_CA_FAST_RETRANSMIT;
+		call->cong_ssthresh = umax(summary->in_flight / 2, 2);
+		call->cong_cwnd = call->cong_ssthresh + 3;
+		call->cong_extra = 0;
+		call->cong_dup_acks = 0;
+		summary->need_retransmit = true;
+		summary->in_fast_or_rto_recovery = true;
+		goto out;
+
+	case RXRPC_CA_FAST_RETRANSMIT:
+		rxrpc_tlp_init(call);
+		summary->in_fast_or_rto_recovery = true;
+		if (!summary->new_low_snack) {
+			if (summary->nr_new_sacks == 0)
+				call->cong_cwnd += 1;
+			call->cong_dup_acks++;
+			if (call->cong_dup_acks == 2) {
+				summary->change = rxrpc_cong_retransmit_again;
+				call->cong_dup_acks = 0;
+				summary->need_retransmit = true;
+			}
+		} else {
+			summary->change = rxrpc_cong_progress;
+			call->cong_cwnd = call->cong_ssthresh;
+			if (call->acks_nr_snacks == 0) {
+				summary->exiting_fast_or_rto_recovery = true;
+				goto resume_normality;
+			}
+		}
+		goto out;
+
+	default:
+		BUG();
+		goto out;
+	}
+
+resume_normality:
+	summary->change = rxrpc_cong_cleared_nacks;
+	call->cong_dup_acks = 0;
+	call->cong_extra = 0;
+	call->cong_tstamp = call->acks_latest_ts;
+	if (call->cong_cwnd < call->cong_ssthresh)
+		call->cong_ca_state = RXRPC_CA_SLOW_START;
+	else
+		call->cong_ca_state = RXRPC_CA_CONGEST_AVOIDANCE;
+out:
+	call->cong_cumul_acks = 0;
+out_no_clear_ca:
+	if (call->cong_cwnd >= RXRPC_TX_MAX_WINDOW)
+		call->cong_cwnd = RXRPC_TX_MAX_WINDOW;
+	trace_rxrpc_congest(call, summary);
+	return;
+
+packet_loss_detected:
+	summary->change = rxrpc_cong_saw_nack;
+	call->cong_ca_state = RXRPC_CA_PACKET_LOSS;
+	call->cong_dup_acks = 0;
+	goto send_extra_data;
+
+send_extra_data:
+	/* Send some previously unsent DATA if we have some to advance the ACK
+	 * state.
+	 */
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ||
+	    call->acks_nr_sacks != call->tx_top - call->tx_bottom) {
+		call->cong_extra++;
+		wake_up(&call->waitq);
+	}
+	goto out_no_clear_ca;
+}
+
+/*
+ * Degrade the congestion window if we haven't transmitted a packet for >1RTT.
+ */
+void rxrpc_congestion_degrade(struct rxrpc_call *call)
+{
+	ktime_t rtt, now, time_since;
+
+	if (call->cong_ca_state != RXRPC_CA_SLOW_START &&
+	    call->cong_ca_state != RXRPC_CA_CONGEST_AVOIDANCE)
+		return;
+	if (__rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_ACK ||
+	    __rxrpc_call_state(call) == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+		return;
+
+	rtt = ns_to_ktime(call->srtt_us * (NSEC_PER_USEC / 8));
+	now = ktime_get_real();
+	time_since = ktime_sub(now, call->tx_last_sent);
+	if (ktime_before(time_since, rtt))
+		return;
+
+	trace_rxrpc_reset_cwnd(call, time_since, rtt);
+	rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset);
+	call->tx_last_sent = now;
+	call->cong_ca_state = RXRPC_CA_SLOW_START;
+	call->cong_ssthresh = umax(call->cong_ssthresh, call->cong_cwnd * 3 / 4);
+	call->cong_cwnd = umax(call->cong_cwnd / 2, RXRPC_MIN_CWND);
+}
+
+/*
+ * Add an RTT sample derived from an ACK'd DATA packet.
+ */
+static void rxrpc_add_data_rtt_sample(struct rxrpc_call *call,
+				      struct rxrpc_ack_summary *summary,
+				      struct rxrpc_txqueue *tq,
+				      int ix)
+{
+	ktime_t xmit_ts = ktime_add_us(tq->xmit_ts_base, tq->segment_xmit_ts[ix]);
+
+	rxrpc_call_add_rtt(call, rxrpc_rtt_rx_data_ack, -1,
+			   summary->acked_serial, summary->ack_serial,
+			   xmit_ts, call->acks_latest_ts);
+	__clear_bit(ix, &tq->rtt_samples); /* Prevent repeat RTT sample */
+}
+
+/*
+ * Apply a hard ACK by advancing the Tx window.
+ */
+static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
+				   struct rxrpc_ack_summary *summary)
+{
+	struct rxrpc_txqueue *tq = call->tx_queue;
+	rxrpc_seq_t seq = call->tx_bottom + 1;
+	bool rot_last = false, trace = false;
+
+	_enter("%x,%x", call->tx_bottom, to);
+
+	trace_rxrpc_tx_rotate(call, seq, to);
+	trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate);
+
+	if (call->acks_lowest_nak == call->tx_bottom) {
+		call->acks_lowest_nak = to;
+	} else if (after(to, call->acks_lowest_nak)) {
+		summary->new_low_snack = true;
+		call->acks_lowest_nak = to;
+	}
+
+	if (after(seq, to))
+		return false;
+
+	/* We may have a left over fully-consumed buffer at the front that we
+	 * couldn't drop before (rotate_and_keep below).
+	 */
+	if (seq == call->tx_qbase + RXRPC_NR_TXQUEUE) {
+		call->tx_qbase += RXRPC_NR_TXQUEUE;
+		call->tx_queue = tq->next;
+		trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free);
+		kfree(tq);
+		tq = call->tx_queue;
+	}
+
+	while (before_eq(seq, to)) {
+		unsigned int ix = seq - call->tx_qbase;
+
+		_debug("tq=%x seq=%x i=%d f=%x", tq->qbase, seq, ix, tq->bufs[ix]->flags);
+		if (tq->bufs[ix]->flags & RXRPC_LAST_PACKET) {
+			set_bit(RXRPC_CALL_TX_LAST, &call->flags);
+			rot_last = true;
+		}
+
+		if (summary->acked_serial == tq->segment_serial[ix] &&
+		    test_bit(ix, &tq->rtt_samples))
+			rxrpc_add_data_rtt_sample(call, summary, tq, ix);
+
+		if (ix == tq->nr_reported_acks) {
+			/* Packet directly hard ACK'd. */
+			tq->nr_reported_acks++;
+			rxrpc_input_rack_one(call, summary, tq, ix);
+			if (seq == call->tlp_seq)
+				summary->tlp_probe_acked = true;
+			summary->nr_new_hacks++;
+			__set_bit(ix, &tq->segment_acked);
+			trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_hack);
+		} else if (test_bit(ix, &tq->segment_acked)) {
+			/* Soft ACK -> hard ACK. */
+			call->acks_nr_sacks--;
+			trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_sack);
+		} else {
+			/* Soft NAK -> hard ACK. */
+			call->acks_nr_snacks--;
+			rxrpc_input_rack_one(call, summary, tq, ix);
+			if (seq == call->tlp_seq)
+				summary->tlp_probe_acked = true;
+			summary->nr_new_hacks++;
+			__set_bit(ix, &tq->segment_acked);
+			trace_rxrpc_rotate(call, tq, summary, seq, rxrpc_rotate_trace_snak);
+		}
+
+		call->tx_nr_sent--;
+		if (__test_and_clear_bit(ix, &tq->segment_lost))
+			call->tx_nr_lost--;
+		if (__test_and_clear_bit(ix, &tq->segment_retransmitted))
+			call->tx_nr_resent--;
+		__clear_bit(ix, &tq->ever_retransmitted);
+
+		rxrpc_put_txbuf(tq->bufs[ix], rxrpc_txbuf_put_rotated);
+		tq->bufs[ix] = NULL;
+
+		WRITE_ONCE(call->tx_bottom, seq);
+		trace_rxrpc_txqueue(call, (rot_last ?
+					   rxrpc_txqueue_rotate_last :
+					   rxrpc_txqueue_rotate));
+
+		seq++;
+		trace = true;
+		if (!(seq & RXRPC_TXQ_MASK)) {
+			trace_rxrpc_rack_update(call, summary);
+			trace = false;
+			prefetch(tq->next);
+			if (tq != call->tx_qtail) {
+				call->tx_qbase += RXRPC_NR_TXQUEUE;
+				call->tx_queue = tq->next;
+				trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free);
+				kfree(tq);
+				tq = call->tx_queue;
+			} else {
+				trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_keep);
+				tq = NULL;
+				break;
+			}
+		}
+	}
+
+	if (trace)
+		trace_rxrpc_rack_update(call, summary);
+
+	if (rot_last) {
+		set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags);
+		if (tq) {
+			trace_rxrpc_tq(call, tq, seq, rxrpc_tq_rotate_and_free);
+			kfree(tq);
+			call->tx_queue = NULL;
+		}
+	}
+
+	_debug("%x,%x,%x,%d", to, call->tx_bottom, call->tx_top, rot_last);
+
+	wake_up(&call->waitq);
+	return rot_last;
+}
+
+/*
+ * End the transmission phase of a call.
+ *
+ * This occurs when we get an ACKALL packet, the first DATA packet of a reply,
+ * or a final ACK packet.
+ */
+static void rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
+			       enum rxrpc_abort_reason abort_why)
+{
+	ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
+
+	call->rack_timer_mode = RXRPC_CALL_RACKTIMER_OFF;
+	call->rack_timo_at = KTIME_MAX;
+	trace_rxrpc_rack_timer(call, 0, false);
+	trace_rxrpc_timer_can(call, rxrpc_timer_trace_rack_off + call->rack_timer_mode);
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_ACK:
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		if (reply_begun) {
+			rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_RECV_REPLY);
+			trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
+			break;
+		}
+
+		rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_REPLY);
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply);
+		break;
+
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		rxrpc_call_completed(call);
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
+		break;
+
+	default:
+		kdebug("end_tx %s", rxrpc_call_states[__rxrpc_call_state(call)]);
+		rxrpc_proto_abort(call, call->tx_top, abort_why);
+		break;
+	}
+}
+
+/*
+ * Begin the reply reception phase of a call.
+ */
+static bool rxrpc_receiving_reply(struct rxrpc_call *call)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	rxrpc_seq_t top = READ_ONCE(call->tx_top);
+
+	if (call->ackr_reason) {
+		call->delay_ack_at = KTIME_MAX;
+		trace_rxrpc_timer_can(call, rxrpc_timer_trace_delayed_ack);
+	}
+
+	/* Deal with an apparent reply coming in before we've got the request
+	 * queued or transmitted.
+	 */
+	if (!test_bit(RXRPC_CALL_EXPOSED, &call->flags)) {
+		rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
+		return false;
+	}
+
+	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
+		if (!rxrpc_rotate_tx_window(call, top, &summary)) {
+			rxrpc_proto_abort(call, top, rxrpc_eproto_early_reply);
+			return false;
+		}
+	}
+
+	rxrpc_end_tx_phase(call, true, rxrpc_eproto_unexpected_reply);
+	return true;
+}
+
+/*
+ * End the packet reception phase.
+ */
+static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
+{
+	rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq);
+
+	_enter("%d,%s", call->debug_id, rxrpc_call_states[__rxrpc_call_state(call)]);
+
+	trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_RECV_REPLY:
+		rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);
+		rxrpc_call_completed(call);
+		break;
+
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_ACK_REQUEST);
+		call->expect_req_by = KTIME_MAX;
+		rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_processing_op);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
+					  rxrpc_seq_t window, rxrpc_seq_t wtop)
+{
+	call->ackr_window = window;
+	call->ackr_wtop = wtop;
+}
+
+/*
+ * Push a DATA packet onto the Rx queue.
+ */
+static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb,
+				   rxrpc_seq_t window, rxrpc_seq_t wtop,
+				   enum rxrpc_receive_trace why)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
+
+	spin_lock_irq(&call->recvmsg_queue.lock);
+
+	__skb_queue_tail(&call->recvmsg_queue, skb);
+	rxrpc_input_update_ack_window(call, window, wtop);
+	trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq);
+	if (last)
+		/* Change the state inside the lock so that recvmsg syncs
+		 * correctly with it and using sendmsg() to send a reply
+		 * doesn't race.
+		 */
+		rxrpc_end_rx_phase(call, sp->hdr.serial);
+
+	spin_unlock_irq(&call->recvmsg_queue.lock);
+}
+
+/*
+ * Process a DATA packet.
+ */
+static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb,
+				 bool *_notify, rxrpc_serial_t *_ack_serial, int *_ack_reason)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct sk_buff *oos;
+	rxrpc_serial_t serial = sp->hdr.serial;
+	unsigned int sack = call->ackr_sack_base;
+	rxrpc_seq_t window = call->ackr_window;
+	rxrpc_seq_t wtop = call->ackr_wtop;
+	rxrpc_seq_t wlimit = window + call->rx_winsize - 1;
+	rxrpc_seq_t seq = sp->hdr.seq;
+	bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
+	int ack_reason = -1;
+
+	rxrpc_inc_stat(call->rxnet, stat_rx_data);
+	if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
+	if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
+		rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
+
+	if (last) {
+		if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    seq + 1 != wtop)
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_different_last);
+	} else {
+		if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
+		    after_eq(seq, wtop)) {
+			pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
+				call->debug_id, seq, window, wtop, wlimit);
+			return rxrpc_proto_abort(call, seq, rxrpc_eproto_data_after_last);
+		}
+	}
+
+	if (after(seq, call->rx_highest_seq))
+		call->rx_highest_seq = seq;
+
+	trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
+
+	if (before(seq, window)) {
+		ack_reason = RXRPC_ACK_DUPLICATE;
+		goto send_ack;
+	}
+	if (after(seq, wlimit)) {
+		ack_reason = RXRPC_ACK_EXCEEDS_WINDOW;
+		goto send_ack;
+	}
+
+	/* Queue the packet. */
+	if (seq == window) {
+		if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+			ack_reason = RXRPC_ACK_REQUESTED;
+		/* Send an immediate ACK if we fill in a hole */
+		else if (!skb_queue_empty(&call->rx_oos_queue))
+			ack_reason = RXRPC_ACK_DELAY;
+
+		window++;
+		if (after(window, wtop)) {
+			trace_rxrpc_sack(call, seq, sack, rxrpc_sack_none);
+			wtop = window;
+		} else {
+			trace_rxrpc_sack(call, seq, sack, rxrpc_sack_advance);
+			sack = (sack + 1) % RXRPC_SACK_SIZE;
+		}
+
+
+		rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg);
+
+		rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue);
+		*_notify = true;
+
+		while ((oos = skb_peek(&call->rx_oos_queue))) {
+			struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
+
+			if (after(osp->hdr.seq, window))
+				break;
+
+			__skb_unlink(oos, &call->rx_oos_queue);
+			last = osp->hdr.flags & RXRPC_LAST_PACKET;
+			seq = osp->hdr.seq;
+			call->ackr_sack_table[sack] = 0;
+			trace_rxrpc_sack(call, seq, sack, rxrpc_sack_fill);
+			sack = (sack + 1) % RXRPC_SACK_SIZE;
+
+			window++;
+			rxrpc_input_queue_data(call, oos, window, wtop,
+					       rxrpc_receive_queue_oos);
+		}
+
+		call->ackr_sack_base = sack;
+	} else {
+		unsigned int slot;
+
+		ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE;
+
+		slot = seq - window;
+		sack = (sack + slot) % RXRPC_SACK_SIZE;
+
+		if (call->ackr_sack_table[sack % RXRPC_SACK_SIZE]) {
+			ack_reason = RXRPC_ACK_DUPLICATE;
+			goto send_ack;
+		}
+
+		call->ackr_sack_table[sack % RXRPC_SACK_SIZE] |= 1;
+		trace_rxrpc_sack(call, seq, sack, rxrpc_sack_oos);
+
+		if (after(seq + 1, wtop)) {
+			wtop = seq + 1;
+			rxrpc_input_update_ack_window(call, window, wtop);
+		}
+
+		skb_queue_walk(&call->rx_oos_queue, oos) {
+			struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
+
+			if (after(osp->hdr.seq, seq)) {
+				rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
+				__skb_queue_before(&call->rx_oos_queue, oos, skb);
+				goto oos_queued;
+			}
+		}
+
+		rxrpc_get_skb(skb, rxrpc_skb_get_to_recvmsg_oos);
+		__skb_queue_tail(&call->rx_oos_queue, skb);
+	oos_queued:
+		trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos,
+				    sp->hdr.serial, sp->hdr.seq);
+	}
+
+send_ack:
+	if (ack_reason >= 0) {
+		if (rxrpc_ack_priority[ack_reason] > rxrpc_ack_priority[*_ack_reason]) {
+			*_ack_serial = serial;
+			*_ack_reason = ack_reason;
+		} else if (rxrpc_ack_priority[ack_reason] == rxrpc_ack_priority[*_ack_reason] &&
+			   ack_reason == RXRPC_ACK_REQUESTED) {
+			*_ack_serial = serial;
+			*_ack_reason = ack_reason;
+		}
+	}
+}
+
+/*
+ * Split a jumbo packet and file the bits separately.
+ */
+static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_jumbo_header jhdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
+	struct sk_buff *jskb;
+	rxrpc_serial_t ack_serial = 0;
+	unsigned int offset = sizeof(struct rxrpc_wire_header);
+	unsigned int len = skb->len - offset;
+	bool notify = false;
+	int ack_reason = 0, count = 1, stat_ix;
+
+	while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
+		if (len < RXRPC_JUMBO_SUBPKTLEN)
+			goto protocol_error;
+		if (sp->hdr.flags & RXRPC_LAST_PACKET)
+			goto protocol_error;
+		if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
+				  &jhdr, sizeof(jhdr)) < 0)
+			goto protocol_error;
+
+		jskb = skb_clone(skb, GFP_NOFS);
+		if (!jskb) {
+			kdebug("couldn't clone");
+			return false;
+		}
+		rxrpc_new_skb(jskb, rxrpc_skb_new_jumbo_subpacket);
+		jsp = rxrpc_skb(jskb);
+		jsp->offset = offset;
+		jsp->len = RXRPC_JUMBO_DATALEN;
+		rxrpc_input_data_one(call, jskb, &notify, &ack_serial, &ack_reason);
+		rxrpc_free_skb(jskb, rxrpc_skb_put_jumbo_subpacket);
+
+		sp->hdr.flags = jhdr.flags;
+		sp->hdr._rsvd = ntohs(jhdr._rsvd);
+		sp->hdr.seq++;
+		sp->hdr.serial++;
+		offset += RXRPC_JUMBO_SUBPKTLEN;
+		len -= RXRPC_JUMBO_SUBPKTLEN;
+		count++;
+	}
+
+	sp->offset = offset;
+	sp->len    = len;
+	rxrpc_input_data_one(call, skb, &notify, &ack_serial, &ack_reason);
+
+	stat_ix = umin(count, ARRAY_SIZE(call->rxnet->stat_rx_jumbo)) - 1;
+	atomic_inc(&call->rxnet->stat_rx_jumbo[stat_ix]);
+
+	if (ack_reason > 0) {
+		rxrpc_send_ACK(call, ack_reason, ack_serial,
+			       rxrpc_propose_ack_input_data);
+	} else {
+		call->ackr_nr_unacked++;
+		rxrpc_propose_delay_ACK(call, sp->hdr.serial,
+					rxrpc_propose_ack_input_data);
+	}
+	if (notify && !test_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags)) {
+		trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial);
+		rxrpc_notify_socket(call);
+	}
+	return true;
+
+protocol_error:
+	return false;
+}
+
+/*
+ * Process a DATA packet, adding the packet to the Rx ring.  The caller's
+ * packet ref must be passed on or discarded.
+ */
+static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	rxrpc_serial_t serial = sp->hdr.serial;
+	rxrpc_seq_t seq0 = sp->hdr.seq;
+
+	_enter("{%x,%x,%x},{%u,%x}",
+	       call->ackr_window, call->ackr_wtop, call->rx_highest_seq,
+	       skb->len, seq0);
+
+	if (__rxrpc_call_is_complete(call))
+		return;
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_ACK:
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		/* Received data implicitly ACKs all of the request
+		 * packets we sent when we're acting as a client.
+		 */
+		if (!rxrpc_receiving_reply(call))
+			goto out_notify;
+		break;
+
+	case RXRPC_CALL_SERVER_RECV_REQUEST: {
+		unsigned long timo = READ_ONCE(call->next_req_timo);
+
+		if (timo) {
+			ktime_t delay = ms_to_ktime(timo);
+
+			call->expect_req_by = ktime_add(ktime_get_real(), delay);
+			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_idle);
+		}
+		break;
+	}
+
+	default:
+		break;
+	}
+
+	if (!rxrpc_input_split_jumbo(call, skb)) {
+		rxrpc_proto_abort(call, sp->hdr.seq, rxrpc_badmsg_bad_jumbo);
+		goto out_notify;
+	}
+	return;
+
+out_notify:
+	trace_rxrpc_notify_socket(call->debug_id, serial);
+	rxrpc_notify_socket(call);
+	_leave(" [queued]");
+}
+
+/*
+ * See if there's a cached RTT probe to complete.
+ */
+static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
+				     ktime_t resp_time,
+				     rxrpc_serial_t acked_serial,
+				     rxrpc_serial_t ack_serial,
+				     enum rxrpc_rtt_rx_trace type)
+{
+	rxrpc_serial_t orig_serial;
+	unsigned long avail;
+	ktime_t sent_at;
+	bool matched = false;
+	int i;
+
+	avail = READ_ONCE(call->rtt_avail);
+	smp_rmb(); /* Read avail bits before accessing data. */
+
+	for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
+		if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
+			continue;
+
+		sent_at = call->rtt_sent_at[i];
+		orig_serial = call->rtt_serial[i];
+
+		if (orig_serial == acked_serial) {
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_mb(); /* Read data before setting avail bit */
+			set_bit(i, &call->rtt_avail);
+			rxrpc_call_add_rtt(call, type, i, acked_serial, ack_serial,
+					   sent_at, resp_time);
+			matched = true;
+		}
+
+		/* If a later serial is being acked, then mark this slot as
+		 * being available.
+		 */
+		if (after(acked_serial, orig_serial)) {
+			trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
+					   orig_serial, acked_serial, 0, 0, 0);
+			clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+			smp_wmb();
+			set_bit(i, &call->rtt_avail);
+		}
+	}
+
+	if (!matched)
+		trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0, 0);
+}
+
+/*
+ * Process the extra information that may be appended to an ACK packet
+ */
+static void rxrpc_input_ack_trailer(struct rxrpc_call *call, struct sk_buff *skb,
+				    struct rxrpc_acktrailer *trailer)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_peer *peer = call->peer;
+	unsigned int max_data, capacity;
+	bool wake = false;
+	u32 max_mtu	= ntohl(trailer->maxMTU);
+	//u32 if_mtu	= ntohl(trailer->ifMTU);
+	u32 rwind	= ntohl(trailer->rwind);
+	u32 jumbo_max	= ntohl(trailer->jumbo_max);
+
+	if (rwind > RXRPC_TX_MAX_WINDOW)
+		rwind = RXRPC_TX_MAX_WINDOW;
+	if (call->tx_winsize != rwind) {
+		if (rwind > call->tx_winsize)
+			wake = true;
+		trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
+		call->tx_winsize = rwind;
+	}
+
+	max_mtu = clamp(max_mtu, 500, 65535);
+	peer->ackr_max_data = max_mtu;
+
+	if (max_mtu < peer->max_data) {
+		trace_rxrpc_pmtud_reduce(peer, sp->hdr.serial, max_mtu,
+					 rxrpc_pmtud_reduce_ack);
+		peer->max_data = max_mtu;
+	}
+
+	max_data = umin(max_mtu, peer->max_data);
+	capacity = max_data;
+	capacity += sizeof(struct rxrpc_jumbo_header); /* First subpacket has main hdr, not jumbo */
+	capacity /= sizeof(struct rxrpc_jumbo_header) + RXRPC_JUMBO_DATALEN;
+
+	if (jumbo_max == 0) {
+		/* The peer says it supports pmtu discovery */
+		peer->ackr_adv_pmtud = true;
+	} else {
+		peer->ackr_adv_pmtud = false;
+		capacity = clamp(capacity, 1, jumbo_max);
+	}
+
+	call->tx_jumbo_max = capacity;
+
+	if (wake)
+		wake_up(&call->waitq);
+}
+
+#if defined(CONFIG_X86) && __GNUC__ && !defined(__clang__)
+/* Clang doesn't support the %z constraint modifier */
+#define shiftr_adv_rotr(shift_from, rotate_into) ({			\
+			asm(" shr%z1 %1\n"				\
+			    " inc %0\n"					\
+			    " rcr%z2 %2\n"				\
+			    : "+d"(shift_from), "+m"(*(shift_from)), "+rm"(rotate_into) \
+			    );						\
+		})
+#else
+#define shiftr_adv_rotr(shift_from, rotate_into) ({	\
+			typeof(rotate_into) __bit0 = *(shift_from) & 1;	\
+			*(shift_from) >>= 1;				\
+			shift_from++;					\
+			rotate_into >>= 1;				\
+			rotate_into |= __bit0 << (sizeof(rotate_into) * 8 - 1); \
+		})
+#endif
+
+/*
+ * Deal with RTT samples from soft ACKs.
+ */
+static void rxrpc_input_soft_rtt(struct rxrpc_call *call,
+				 struct rxrpc_ack_summary *summary,
+				 struct rxrpc_txqueue *tq)
+{
+	for (int ix = 0; ix < RXRPC_NR_TXQUEUE; ix++)
+		if (summary->acked_serial == tq->segment_serial[ix])
+			return rxrpc_add_data_rtt_sample(call, summary, tq, ix);
+}
+
+/*
+ * Process a batch of soft ACKs specific to a transmission queue segment.
+ */
+static void rxrpc_input_soft_ack_tq(struct rxrpc_call *call,
+				    struct rxrpc_ack_summary *summary,
+				    struct rxrpc_txqueue *tq,
+				    unsigned long extracted_acks,
+				    int nr_reported,
+				    rxrpc_seq_t seq,
+				    rxrpc_seq_t *lowest_nak)
+{
+	unsigned long old_reported = 0, flipped, new_acks = 0;
+	unsigned long a_to_n, n_to_a = 0;
+	int new, a, n;
+
+	if (tq->nr_reported_acks > 0)
+		old_reported = ~0UL >> (RXRPC_NR_TXQUEUE - tq->nr_reported_acks);
+
+	_enter("{%x,%lx,%d},%lx,%d,%x",
+	       tq->qbase, tq->segment_acked, tq->nr_reported_acks,
+	       extracted_acks, nr_reported, seq);
+
+	_debug("[%x]", tq->qbase);
+	_debug("tq    %16lx %u", tq->segment_acked, tq->nr_reported_acks);
+	_debug("sack  %16lx %u", extracted_acks, nr_reported);
+
+	/* See how many previously logged ACKs/NAKs have flipped. */
+	flipped = (tq->segment_acked ^ extracted_acks) & old_reported;
+	if (flipped) {
+		n_to_a = ~tq->segment_acked & flipped; /* Old NAK -> ACK */
+		a_to_n =  tq->segment_acked & flipped; /* Old ACK -> NAK */
+		a = hweight_long(n_to_a);
+		n = hweight_long(a_to_n);
+		_debug("flip  %16lx", flipped);
+		_debug("ntoa  %16lx %d", n_to_a, a);
+		_debug("aton  %16lx %d", a_to_n, n);
+		call->acks_nr_sacks	+= a - n;
+		call->acks_nr_snacks	+= n - a;
+		summary->nr_new_sacks	+= a;
+		summary->nr_new_snacks	+= n;
+	}
+
+	/* See how many new ACKs/NAKs have been acquired. */
+	new = nr_reported - tq->nr_reported_acks;
+	if (new > 0) {
+		new_acks = extracted_acks & ~old_reported;
+		if (new_acks) {
+			a = hweight_long(new_acks);
+			n = new - a;
+			_debug("new_a %16lx new=%d a=%d n=%d", new_acks, new, a, n);
+			call->acks_nr_sacks	+= a;
+			call->acks_nr_snacks	+= n;
+			summary->nr_new_sacks	+= a;
+			summary->nr_new_snacks	+= n;
+		} else {
+			call->acks_nr_snacks	+= new;
+			summary->nr_new_snacks	+= new;
+		}
+	}
+
+	tq->nr_reported_acks = nr_reported;
+	tq->segment_acked = extracted_acks;
+	trace_rxrpc_apply_acks(call, tq);
+
+	if (extracted_acks != ~0UL) {
+		rxrpc_seq_t lowest = seq + ffz(extracted_acks);
+
+		if (before(lowest, *lowest_nak))
+			*lowest_nak = lowest;
+	}
+
+	if (summary->acked_serial)
+		rxrpc_input_soft_rtt(call, summary, tq);
+
+	new_acks |= n_to_a;
+	if (new_acks)
+		rxrpc_input_rack(call, summary, tq, new_acks);
+
+	if (call->tlp_serial &&
+	    rxrpc_seq_in_txq(tq, call->tlp_seq) &&
+	    test_bit(call->tlp_seq - tq->qbase, &new_acks))
+		summary->tlp_probe_acked = true;
+}
+
+/*
+ * Process individual soft ACKs.
+ *
+ * Each ACK in the array corresponds to one packet and can be either an ACK or
+ * a NAK.  If we get find an explicitly NAK'd packet we resend immediately;
+ * packets that lie beyond the end of the ACK list are scheduled for resend by
+ * the timer on the basis that the peer might just not have processed them at
+ * the time the ACK was sent.
+ */
+static void rxrpc_input_soft_acks(struct rxrpc_call *call,
+				  struct rxrpc_ack_summary *summary,
+				  struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_txqueue *tq = call->tx_queue;
+	unsigned long extracted = ~0UL;
+	unsigned int nr = 0, nsack;
+	rxrpc_seq_t seq = call->acks_hard_ack + 1;
+	rxrpc_seq_t lowest_nak = seq + sp->ack.nr_acks;
+	u8 sack[256] __aligned(sizeof(unsigned long));
+	u8 *acks = sack;
+
+	_enter("%x,%x,%u", tq->qbase, seq, sp->ack.nr_acks);
+
+	while (after(seq, tq->qbase + RXRPC_NR_TXQUEUE - 1))
+		tq = tq->next;
+
+	/* Extract an individual SACK table.  A normal SACK table is up to 255
+	 * bytes with 1 ACK flag per byte, but an extended SACK table can be up
+	 * to 256 bytes with up to 8 ACK/NACK flags per byte.  The ACK flags go
+	 * across all bit 0's then all bit 1's, then all bit 2's, ...
+	 */
+	memset(sack, 0, sizeof(sack));
+	nsack = umin(sp->ack.nr_acks, 256);
+	if (skb_copy_bits(skb,
+			  sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket),
+			  sack, nsack) < 0)
+		return;
+
+	for (unsigned int i = 0; i < sp->ack.nr_acks; i++) {
+		/* Decant ACKs until we hit a txqueue boundary. */
+		if ((i & 255) == 0)
+			acks = sack;
+		shiftr_adv_rotr(acks, extracted);
+		seq++;
+		nr++;
+		if ((seq & RXRPC_TXQ_MASK) != 0)
+			continue;
+
+		_debug("bound %16lx %u", extracted, nr);
+
+		rxrpc_input_soft_ack_tq(call, summary, tq, extracted, RXRPC_NR_TXQUEUE,
+					seq - RXRPC_NR_TXQUEUE, &lowest_nak);
+		extracted = ~0UL;
+		nr = 0;
+		tq = tq->next;
+		prefetch(tq);
+	}
+
+	if (nr) {
+		unsigned int nr_reported = seq & RXRPC_TXQ_MASK;
+
+		extracted >>= RXRPC_NR_TXQUEUE - nr_reported;
+		_debug("tail  %16lx %u", extracted, nr_reported);
+		rxrpc_input_soft_ack_tq(call, summary, tq, extracted, nr_reported,
+					seq & ~RXRPC_TXQ_MASK, &lowest_nak);
+	}
+
+	/* We *can* have more nacks than we did - the peer is permitted to drop
+	 * packets it has soft-acked and re-request them.  Further, it is
+	 * possible for the nack distribution to change whilst the number of
+	 * nacks stays the same or goes down.
+	 */
+	if (lowest_nak != call->acks_lowest_nak) {
+		call->acks_lowest_nak = lowest_nak;
+		summary->new_low_snack = true;
+	}
+
+	_debug("summary A=%d+%d N=%d+%d",
+	       call->acks_nr_sacks,  summary->nr_new_sacks,
+	       call->acks_nr_snacks, summary->nr_new_snacks);
+}
+
+/*
+ * Return true if the ACK is valid - ie. it doesn't appear to have regressed
+ * with respect to the ack state conveyed by preceding ACKs.
+ */
+static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
+			       rxrpc_seq_t hard_ack, rxrpc_seq_t prev_pkt)
+{
+	rxrpc_seq_t base = READ_ONCE(call->acks_hard_ack);
+
+	if (after(hard_ack, base))
+		return true; /* The window advanced */
+
+	if (before(hard_ack, base))
+		return false; /* firstPacket regressed */
+
+	if (after_eq(prev_pkt, call->acks_prev_seq))
+		return true; /* previousPacket hasn't regressed. */
+
+	/* Some rx implementations put a serial number in previousPacket. */
+	if (after(prev_pkt, base + call->tx_winsize))
+		return false;
+	return true;
+}
+
+/*
+ * Process an ACK packet.
+ *
+ * ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
+ * in the ACK array.  Anything before that is hard-ACK'd and may be discarded.
+ *
+ * A hard-ACK means that a packet has been processed and may be discarded; a
+ * soft-ACK means that the packet may be discarded and retransmission
+ * requested.  A phase is complete when all packets are hard-ACK'd.
+ */
+static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+	struct rxrpc_acktrailer trailer;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
+	int nr_acks, offset, ioffset;
+
+	_enter("");
+
+	offset = sizeof(struct rxrpc_wire_header) + sizeof(struct rxrpc_ackpacket);
+
+	summary.ack_serial	= sp->hdr.serial;
+	first_soft_ack		= sp->ack.first_ack;
+	prev_pkt		= sp->ack.prev_ack;
+	nr_acks			= sp->ack.nr_acks;
+	hard_ack		= first_soft_ack - 1;
+	summary.acked_serial	= sp->ack.acked_serial;
+	summary.ack_reason	= (sp->ack.reason < RXRPC_ACK__INVALID ?
+				   sp->ack.reason : RXRPC_ACK__INVALID);
+
+	trace_rxrpc_rx_ack(call, sp);
+	rxrpc_inc_stat(call->rxnet, stat_rx_acks[summary.ack_reason]);
+	prefetch(call->tx_queue);
+
+	/* If we get an EXCEEDS_WINDOW ACK from the server, it probably
+	 * indicates that the client address changed due to NAT.  The server
+	 * lost the call because it switched to a different peer.
+	 */
+	if (unlikely(summary.ack_reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
+	    hard_ack == 0 &&
+	    prev_pkt == 0 &&
+	    rxrpc_is_client_call(call)) {
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  0, -ENETRESET);
+		goto send_response;
+	}
+
+	/* If we get an OUT_OF_SEQUENCE ACK from the server, that can also
+	 * indicate a change of address.  However, we can retransmit the call
+	 * if we still have it buffered to the beginning.
+	 */
+	if (unlikely(summary.ack_reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
+	    hard_ack == 0 &&
+	    prev_pkt == 0 &&
+	    call->tx_bottom == 0 &&
+	    rxrpc_is_client_call(call)) {
+		rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+					  0, -ENETRESET);
+		goto send_response;
+	}
+
+	/* Discard any out-of-order or duplicate ACKs (outside lock). */
+	if (!rxrpc_is_ack_valid(call, hard_ack, prev_pkt)) {
+		trace_rxrpc_rx_discard_ack(call, summary.ack_serial, hard_ack, prev_pkt);
+		goto send_response; /* Still respond if requested. */
+	}
+
+	trailer.maxMTU = 0;
+	ioffset = offset + nr_acks + 3;
+	if (skb->len >= ioffset + sizeof(trailer) &&
+	    skb_copy_bits(skb, ioffset, &trailer, sizeof(trailer)) < 0)
+		return rxrpc_proto_abort(call, 0, rxrpc_badmsg_short_ack_trailer);
+
+	call->acks_latest_ts = ktime_get_real();
+	call->acks_hard_ack = hard_ack;
+	call->acks_prev_seq = prev_pkt;
+
+	if (summary.acked_serial) {
+		switch (summary.ack_reason) {
+		case RXRPC_ACK_PING_RESPONSE:
+			rxrpc_complete_rtt_probe(call, call->acks_latest_ts,
+						 summary.acked_serial, summary.ack_serial,
+						 rxrpc_rtt_rx_ping_response);
+			break;
+		default:
+			if (after(summary.acked_serial, call->acks_highest_serial))
+				call->acks_highest_serial = summary.acked_serial;
+			summary.rtt_sample_avail = true;
+			break;
+		}
+	}
+
+	/* Parse rwind and mtu sizes if provided. */
+	if (trailer.maxMTU)
+		rxrpc_input_ack_trailer(call, skb, &trailer);
+
+	if (hard_ack + 1 == 0)
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_zero);
+
+	/* Ignore ACKs unless we are transmitting or are waiting for
+	 * acknowledgement of the packets we've just been transmitting.
+	 */
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_ACK:
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		break;
+	default:
+		goto send_response;
+	}
+
+	if (before(hard_ack, call->tx_bottom) ||
+	    after(hard_ack, call->tx_top))
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_outside_window);
+	if (nr_acks > call->tx_top - hard_ack)
+		return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_sack_overflow);
+
+	if (after(hard_ack, call->tx_bottom)) {
+		if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
+			rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ack);
+			goto send_response;
+		}
+	}
+
+	if (nr_acks > 0) {
+		if (offset > (int)skb->len - nr_acks)
+			return rxrpc_proto_abort(call, 0, rxrpc_eproto_ackr_short_sack);
+		rxrpc_input_soft_acks(call, &summary, skb);
+	}
+
+	if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
+	    call->acks_nr_sacks == call->tx_top - hard_ack &&
+	    rxrpc_is_client_call(call))
+		rxrpc_propose_ping(call, summary.ack_serial,
+				   rxrpc_propose_ack_ping_for_lost_reply);
+
+	/* Drive the congestion management algorithm first and then RACK-TLP as
+	 * the latter depends on the state/change in state in the former.
+	 */
+	rxrpc_congestion_management(call, &summary);
+	rxrpc_rack_detect_loss_and_arm_timer(call, &summary);
+	rxrpc_tlp_process_ack(call, &summary);
+	if (call->tlp_serial && after_eq(summary.acked_serial, call->tlp_serial))
+		call->tlp_serial = 0;
+
+send_response:
+	if (summary.ack_reason == RXRPC_ACK_PING)
+		rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, summary.ack_serial,
+			       rxrpc_propose_ack_respond_to_ping);
+	else if (sp->hdr.flags & RXRPC_REQUEST_ACK)
+		rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, summary.ack_serial,
+			       rxrpc_propose_ack_respond_to_ack);
+}
+
+/*
+ * Process an ACKALL packet.
+ */
+static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_ack_summary summary = { 0 };
+
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_CLIENT_AWAIT_ACK:
+	case RXRPC_CALL_SERVER_SEND_REPLY:
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		break;
+	default:
+		return;
+	}
+
+	if (rxrpc_rotate_tx_window(call, call->tx_transmitted, &summary))
+		rxrpc_end_tx_phase(call, false, rxrpc_eproto_unexpected_ackall);
+}
+
+/*
+ * Process an ABORT packet directed at a call.
+ */
+static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority);
+
+	rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
+				  skb->priority, -ECONNABORTED);
+}
+
+/*
+ * Process an incoming call packet.
+ */
+void rxrpc_input_call_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned long timo;
+
+	_enter("%p,%p", call, skb);
+
+	if (sp->hdr.serviceId != call->dest_srx.srx_service)
+		call->dest_srx.srx_service = sp->hdr.serviceId;
+	if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
+		call->rx_serial = sp->hdr.serial;
+	if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
+		set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
+
+	timo = READ_ONCE(call->next_rx_timo);
+	if (timo) {
+		ktime_t delay = ms_to_ktime(timo);
+
+		call->expect_rx_by = ktime_add(ktime_get_real(), delay);
+		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_expect_rx);
+	}
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_DATA:
+		return rxrpc_input_data(call, skb);
+
+	case RXRPC_PACKET_TYPE_ACK:
+		return rxrpc_input_ack(call, skb);
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		/* Just ignore BUSY packets from the server; the retry and
+		 * lifespan timers will take care of business.  BUSY packets
+		 * from the client don't make sense.
+		 */
+		return;
+
+	case RXRPC_PACKET_TYPE_ABORT:
+		return rxrpc_input_abort(call, skb);
+
+	case RXRPC_PACKET_TYPE_ACKALL:
+		return rxrpc_input_ackall(call, skb);
+
+	default:
+		break;
+	}
+}
+
+/*
+ * Handle a new service call on a channel implicitly completing the preceding
+ * call on that channel.  This does not apply to client conns.
+ *
+ * TODO: If callNumber > call_id + 1, renegotiate security.
+ */
+void rxrpc_implicit_end_call(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	switch (__rxrpc_call_state(call)) {
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		rxrpc_call_completed(call);
+		fallthrough;
+	case RXRPC_CALL_COMPLETE:
+		break;
+	default:
+		rxrpc_abort_call(call, 0, RX_CALL_DEAD, -ESHUTDOWN,
+				 rxrpc_eproto_improper_term);
+		trace_rxrpc_improper_term(call);
+		break;
+	}
+
+	rxrpc_input_call_event(call);
+}
diff --git a/net/rxrpc/input_rack.c b/net/rxrpc/input_rack.c
new file mode 100644
index 000000000..9eb109ffb
--- /dev/null
+++ b/net/rxrpc/input_rack.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RACK-TLP [RFC8958] Implementation
+ *
+ * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ar-internal.h"
+
+static bool rxrpc_rack_sent_after(ktime_t t1, rxrpc_seq_t seq1,
+				  ktime_t t2, rxrpc_seq_t seq2)
+{
+	if (ktime_after(t1, t2))
+		return true;
+	return t1 == t2 && after(seq1, seq2);
+}
+
+/*
+ * Mark a packet lost.
+ */
+static void rxrpc_rack_mark_lost(struct rxrpc_call *call,
+				 struct rxrpc_txqueue *tq, unsigned int ix)
+{
+	if (__test_and_set_bit(ix, &tq->segment_lost)) {
+		if (__test_and_clear_bit(ix, &tq->segment_retransmitted))
+			call->tx_nr_resent--;
+	} else {
+		call->tx_nr_lost++;
+	}
+	tq->segment_xmit_ts[ix] = UINT_MAX;
+}
+
+/*
+ * Get the transmission time of a packet in the Tx queue.
+ */
+static ktime_t rxrpc_get_xmit_ts(const struct rxrpc_txqueue *tq, unsigned int ix)
+{
+	if (tq->segment_xmit_ts[ix] == UINT_MAX)
+		return KTIME_MAX;
+	return ktime_add_us(tq->xmit_ts_base, tq->segment_xmit_ts[ix]);
+}
+
+/*
+ * Get a bitmask of nack bits for a queue segment and mask off any that aren't
+ * yet reported.
+ */
+static unsigned long rxrpc_tq_nacks(const struct rxrpc_txqueue *tq)
+{
+	unsigned long nacks = ~tq->segment_acked;
+
+	if (tq->nr_reported_acks < RXRPC_NR_TXQUEUE)
+		nacks &= (1UL << tq->nr_reported_acks) - 1;
+	return nacks;
+}
+
+/*
+ * Update the RACK state for the most recently sent packet that has been
+ * delivered [RFC8958 6.2 Step 2].
+ */
+static void rxrpc_rack_update(struct rxrpc_call *call,
+			      struct rxrpc_ack_summary *summary,
+			      struct rxrpc_txqueue *tq,
+			      unsigned int ix)
+{
+	rxrpc_seq_t seq = tq->qbase + ix;
+	ktime_t xmit_ts = rxrpc_get_xmit_ts(tq, ix);
+	ktime_t rtt = ktime_sub(call->acks_latest_ts, xmit_ts);
+
+	if (__test_and_clear_bit(ix, &tq->segment_lost))
+		call->tx_nr_lost--;
+
+	if (test_bit(ix, &tq->segment_retransmitted)) {
+		/* Use Rx.serial instead of TCP.ACK.ts_option.echo_reply. */
+		if (before(call->acks_highest_serial, tq->segment_serial[ix]))
+			return;
+		if (rtt < minmax_get(&call->min_rtt))
+			return;
+	}
+
+	/* The RACK algorithm requires the segment ACKs to be traversed in
+	 * order of segment transmission - but the only thing this seems to
+	 * matter for is that RACK.rtt is set to the rtt of the most recently
+	 * transmitted segment.  We should be able to achieve the same by only
+	 * setting RACK.rtt if the xmit time is greater.
+	 */
+	if (ktime_after(xmit_ts, call->rack_rtt_ts)) {
+		call->rack_rtt	  = rtt;
+		call->rack_rtt_ts = xmit_ts;
+	}
+
+	if (rxrpc_rack_sent_after(xmit_ts, seq, call->rack_xmit_ts, call->rack_end_seq)) {
+		call->rack_rtt = rtt;
+		call->rack_xmit_ts = xmit_ts;
+		call->rack_end_seq = seq;
+	}
+}
+
+/*
+ * Detect data segment reordering [RFC8958 6.2 Step 3].
+ */
+static void rxrpc_rack_detect_reordering(struct rxrpc_call *call,
+					 struct rxrpc_ack_summary *summary,
+					 struct rxrpc_txqueue *tq,
+					 unsigned int ix)
+{
+	rxrpc_seq_t seq = tq->qbase + ix;
+
+	/* Track the highest sequence number so far ACK'd.  This is not
+	 * necessarily the same as ack.firstPacket + ack.nAcks - 1 as the peer
+	 * could put a NACK in the last SACK slot.
+	 */
+	if (after(seq, call->rack_fack))
+		call->rack_fack = seq;
+	else if (before(seq, call->rack_fack) &&
+		 test_bit(ix, &tq->segment_retransmitted))
+		call->rack_reordering_seen = true;
+}
+
+void rxrpc_input_rack_one(struct rxrpc_call *call,
+			  struct rxrpc_ack_summary *summary,
+			  struct rxrpc_txqueue *tq,
+			  unsigned int ix)
+{
+	rxrpc_rack_update(call, summary, tq, ix);
+	rxrpc_rack_detect_reordering(call, summary, tq, ix);
+}
+
+void rxrpc_input_rack(struct rxrpc_call *call,
+		      struct rxrpc_ack_summary *summary,
+		      struct rxrpc_txqueue *tq,
+		      unsigned long new_acks)
+{
+	while (new_acks) {
+		unsigned int ix = __ffs(new_acks);
+
+		__clear_bit(ix, &new_acks);
+		rxrpc_input_rack_one(call, summary, tq, ix);
+	}
+
+	trace_rxrpc_rack_update(call, summary);
+}
+
+/*
+ * Update the reordering window [RFC8958 6.2 Step 4].  Returns the updated
+ * duration of the reordering window.
+ *
+ * Note that the Rx protocol doesn't have a 'DSACK option' per se, but ACKs can
+ * be given a 'DUPLICATE' reason with the serial number referring to the
+ * duplicated DATA packet.  Rx does not inform as to whether this was a
+ * reception of the same packet twice or of a retransmission of a packet we
+ * already received (though this could be determined by the transmitter based
+ * on the serial number).
+ */
+static ktime_t rxrpc_rack_update_reo_wnd(struct rxrpc_call *call,
+					 struct rxrpc_ack_summary *summary)
+{
+	rxrpc_seq_t snd_una = call->acks_lowest_nak; /* Lowest unack'd seq */
+	rxrpc_seq_t snd_nxt = call->tx_transmitted + 1; /* Next seq to be sent */
+	bool have_dsack_option = summary->ack_reason == RXRPC_ACK_DUPLICATE;
+	int dup_thresh = 3;
+
+	/* DSACK-based reordering window adaptation */
+	if (!call->rack_dsack_round_none &&
+	    after_eq(snd_una, call->rack_dsack_round))
+		call->rack_dsack_round_none = true;
+
+	/* Grow the reordering window per round that sees DSACK.  Reset the
+	 * window after 16 DSACK-free recoveries.
+	 */
+	if (call->rack_dsack_round_none && have_dsack_option) {
+		call->rack_dsack_round_none = false;
+		call->rack_dsack_round = snd_nxt;
+		call->rack_reo_wnd_mult++;
+		call->rack_reo_wnd_persist = 16;
+	} else if (summary->exiting_fast_or_rto_recovery) {
+		call->rack_reo_wnd_persist--;
+		if (call->rack_reo_wnd_persist <= 0)
+			call->rack_reo_wnd_mult = 1;
+	}
+
+	if (!call->rack_reordering_seen) {
+		if (summary->in_fast_or_rto_recovery)
+			return 0;
+		if (call->acks_nr_sacks >= dup_thresh)
+			return 0;
+	}
+
+	return us_to_ktime(umin(call->rack_reo_wnd_mult * minmax_get(&call->min_rtt) / 4,
+				call->srtt_us >> 3));
+}
+
+/*
+ * Detect losses [RFC8958 6.2 Step 5].
+ */
+static ktime_t rxrpc_rack_detect_loss(struct rxrpc_call *call,
+				      struct rxrpc_ack_summary *summary)
+{
+	struct rxrpc_txqueue *tq;
+	ktime_t timeout = 0, lost_after, now = ktime_get_real();
+
+	call->rack_reo_wnd = rxrpc_rack_update_reo_wnd(call, summary);
+	lost_after = ktime_add(call->rack_rtt, call->rack_reo_wnd);
+	trace_rxrpc_rack_scan_loss(call);
+
+	for (tq = call->tx_queue; tq; tq = tq->next) {
+		unsigned long nacks = rxrpc_tq_nacks(tq);
+
+		if (after(tq->qbase, call->tx_transmitted))
+			break;
+		trace_rxrpc_rack_scan_loss_tq(call, tq, nacks);
+
+		/* Skip ones marked lost but not yet retransmitted */
+		nacks &= ~tq->segment_lost | tq->segment_retransmitted;
+
+		while (nacks) {
+			unsigned int ix = __ffs(nacks);
+			rxrpc_seq_t seq = tq->qbase + ix;
+			ktime_t remaining;
+			ktime_t xmit_ts = rxrpc_get_xmit_ts(tq, ix);
+
+			__clear_bit(ix, &nacks);
+
+			if (rxrpc_rack_sent_after(call->rack_xmit_ts, call->rack_end_seq,
+						  xmit_ts, seq)) {
+				remaining = ktime_sub(ktime_add(xmit_ts, lost_after), now);
+				if (remaining <= 0) {
+					rxrpc_rack_mark_lost(call, tq, ix);
+					trace_rxrpc_rack_detect_loss(call, summary, seq);
+				} else {
+					timeout = max(remaining, timeout);
+				}
+			}
+		}
+	}
+
+	return timeout;
+}
+
+/*
+ * Detect losses and set a timer to retry the detection [RFC8958 6.2 Step 5].
+ */
+void rxrpc_rack_detect_loss_and_arm_timer(struct rxrpc_call *call,
+					  struct rxrpc_ack_summary *summary)
+{
+	ktime_t timeout = rxrpc_rack_detect_loss(call, summary);
+
+	if (timeout) {
+		call->rack_timer_mode = RXRPC_CALL_RACKTIMER_RACK_REORDER;
+		call->rack_timo_at = ktime_add(ktime_get_real(), timeout);
+		trace_rxrpc_rack_timer(call, timeout, false);
+		trace_rxrpc_timer_set(call, timeout, rxrpc_timer_trace_rack_reo);
+	}
+}
+
+/*
+ * Handle RACK-TLP RTO expiration [RFC8958 6.3].
+ */
+static void rxrpc_rack_mark_losses_on_rto(struct rxrpc_call *call)
+{
+	struct rxrpc_txqueue *tq;
+	rxrpc_seq_t snd_una = call->acks_lowest_nak; /* Lowest unack'd seq */
+	ktime_t lost_after = ktime_add(call->rack_rtt, call->rack_reo_wnd);
+	ktime_t deadline = ktime_sub(ktime_get_real(), lost_after);
+
+	for (tq = call->tx_queue; tq; tq = tq->next) {
+		unsigned long unacked = ~tq->segment_acked;
+
+		trace_rxrpc_rack_mark_loss_tq(call, tq);
+		while (unacked) {
+			unsigned int ix = __ffs(unacked);
+			rxrpc_seq_t seq = tq->qbase + ix;
+			ktime_t xmit_ts = rxrpc_get_xmit_ts(tq, ix);
+
+			if (after(seq, call->tx_transmitted))
+				return;
+			__clear_bit(ix, &unacked);
+
+			if (seq == snd_una ||
+			    ktime_before(xmit_ts, deadline))
+				rxrpc_rack_mark_lost(call, tq, ix);
+		}
+	}
+}
+
+/*
+ * Calculate the TLP loss probe timeout (PTO) [RFC8958 7.2].
+ */
+ktime_t rxrpc_tlp_calc_pto(struct rxrpc_call *call, ktime_t now)
+{
+	unsigned int flight_size = rxrpc_tx_in_flight(call);
+	ktime_t rto_at = ktime_add(call->tx_last_sent,
+				   rxrpc_get_rto_backoff(call, false));
+	ktime_t pto;
+
+	if (call->rtt_count > 0) {
+		/* Use 2*SRTT as the timeout. */
+		pto = ns_to_ktime(call->srtt_us * NSEC_PER_USEC / 4);
+		if (flight_size)
+			pto = ktime_add(pto, call->tlp_max_ack_delay);
+	} else {
+		pto = NSEC_PER_SEC;
+	}
+
+	if (ktime_after(ktime_add(now, pto), rto_at))
+		pto = ktime_sub(rto_at, now);
+	return pto;
+}
+
+/*
+ * Send a TLP loss probe on PTO expiration [RFC8958 7.3].
+ */
+void rxrpc_tlp_send_probe(struct rxrpc_call *call)
+{
+	unsigned int in_flight = rxrpc_tx_in_flight(call);
+
+	if (after_eq(call->acks_hard_ack, call->tx_transmitted))
+		return; /* Everything we transmitted has been acked. */
+
+	/* There must be no other loss probe still in flight and we need to
+	 * have taken a new RTT sample since last probe or the start of
+	 * connection.
+	 */
+	if (!call->tlp_serial &&
+	    call->tlp_rtt_taken != call->rtt_taken) {
+		call->tlp_is_retrans = false;
+		if (after(call->send_top, call->tx_transmitted) &&
+		    rxrpc_tx_window_space(call) > 0) {
+			/* Transmit the lowest-sequence unsent DATA */
+			call->tx_last_serial = 0;
+			rxrpc_transmit_some_data(call, 1, rxrpc_txdata_tlp_new_data);
+			call->tlp_serial = call->tx_last_serial;
+			call->tlp_seq = call->tx_transmitted;
+			trace_rxrpc_tlp_probe(call, rxrpc_tlp_probe_trace_transmit_new);
+			in_flight = rxrpc_tx_in_flight(call);
+		} else {
+			/* Retransmit the highest-sequence DATA sent */
+			call->tx_last_serial = 0;
+			rxrpc_resend_tlp(call);
+			call->tlp_is_retrans = true;
+			trace_rxrpc_tlp_probe(call, rxrpc_tlp_probe_trace_retransmit);
+		}
+	} else {
+		trace_rxrpc_tlp_probe(call, rxrpc_tlp_probe_trace_busy);
+	}
+
+	if (in_flight != 0) {
+		ktime_t rto = rxrpc_get_rto_backoff(call, false);
+
+		call->rack_timer_mode = RXRPC_CALL_RACKTIMER_RTO;
+		call->rack_timo_at = ktime_add(ktime_get_real(), rto);
+		trace_rxrpc_rack_timer(call, rto, false);
+		trace_rxrpc_timer_set(call, rto, rxrpc_timer_trace_rack_rto);
+	}
+}
+
+/*
+ * Detect losses using the ACK of a TLP loss probe [RFC8958 7.4].
+ */
+void rxrpc_tlp_process_ack(struct rxrpc_call *call, struct rxrpc_ack_summary *summary)
+{
+	if (!call->tlp_serial || after(call->tlp_seq, call->acks_hard_ack))
+		return;
+
+	if (!call->tlp_is_retrans) {
+		/* TLP of new data delivered */
+		trace_rxrpc_tlp_ack(call, summary, rxrpc_tlp_ack_trace_new_data);
+		call->tlp_serial = 0;
+	} else if (summary->ack_reason == RXRPC_ACK_DUPLICATE &&
+		   summary->acked_serial == call->tlp_serial) {
+		/* General Case: Detected packet losses using RACK [7.4.1] */
+		trace_rxrpc_tlp_ack(call, summary, rxrpc_tlp_ack_trace_dup_acked);
+		call->tlp_serial = 0;
+	} else if (after(call->acks_hard_ack, call->tlp_seq)) {
+		/* Repaired the single loss */
+		trace_rxrpc_tlp_ack(call, summary, rxrpc_tlp_ack_trace_hard_beyond);
+		call->tlp_serial = 0;
+		// TODO: Invoke congestion control to react to the loss
+		// event the probe has repaired
+	} else if (summary->tlp_probe_acked) {
+		trace_rxrpc_tlp_ack(call, summary, rxrpc_tlp_ack_trace_acked);
+		/* Special Case: Detected a single loss repaired by the loss
+		 * probe [7.4.2]
+		 */
+		call->tlp_serial = 0;
+	} else {
+		trace_rxrpc_tlp_ack(call, summary, rxrpc_tlp_ack_trace_incomplete);
+	}
+}
+
+/*
+ * Handle RACK timer expiration; returns true to request a resend.
+ */
+void rxrpc_rack_timer_expired(struct rxrpc_call *call, ktime_t overran_by)
+{
+	struct rxrpc_ack_summary summary = {};
+	enum rxrpc_rack_timer_mode mode = call->rack_timer_mode;
+
+	trace_rxrpc_rack_timer(call, overran_by, true);
+	call->rack_timer_mode = RXRPC_CALL_RACKTIMER_OFF;
+
+	switch (mode) {
+	case RXRPC_CALL_RACKTIMER_RACK_REORDER:
+		rxrpc_rack_detect_loss_and_arm_timer(call, &summary);
+		break;
+	case RXRPC_CALL_RACKTIMER_TLP_PTO:
+		rxrpc_tlp_send_probe(call);
+		break;
+	case RXRPC_CALL_RACKTIMER_RTO:
+		// Might need to poke the congestion algo in some way
+		rxrpc_rack_mark_losses_on_rto(call);
+		break;
+	//case RXRPC_CALL_RACKTIMER_ZEROWIN:
+	default:
+		pr_warn("Unexpected rack timer %u", mode);
+	}
+}
diff --git a/net/rxrpc/insecure.c b/net/rxrpc/insecure.c
new file mode 100644
index 000000000..0b39046bd
--- /dev/null
+++ b/net/rxrpc/insecure.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Null security operations.
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static int none_init_connection_security(struct rxrpc_connection *conn,
+					 struct rxrpc_key_token *token)
+{
+	return 0;
+}
+
+/*
+ * Allocate an appropriately sized buffer for the amount of data remaining.
+ */
+static struct rxrpc_txbuf *none_alloc_txbuf(struct rxrpc_call *call, size_t remain, gfp_t gfp)
+{
+	return rxrpc_alloc_data_txbuf(call, umin(remain, RXRPC_JUMBO_DATALEN), 1, gfp);
+}
+
+static int none_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
+{
+	txb->pkt_len = txb->len;
+	if (txb->len == RXRPC_JUMBO_DATALEN)
+		txb->jumboable = true;
+	return 0;
+}
+
+static int none_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	return 0;
+}
+
+static void none_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+static bool none_validate_challenge(struct rxrpc_connection *conn,
+				    struct sk_buff *skb)
+{
+	rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO,
+			 rxrpc_eproto_rxnull_challenge);
+	return true;
+}
+
+static int none_sendmsg_respond_to_challenge(struct sk_buff *challenge,
+					     struct msghdr *msg)
+{
+	return -EINVAL;
+}
+
+static int none_verify_response(struct rxrpc_connection *conn,
+				struct sk_buff *response_skb,
+				void *response, unsigned int len)
+{
+	return rxrpc_abort_conn(conn, response_skb, RX_PROTOCOL_ERROR, -EPROTO,
+				rxrpc_eproto_rxnull_response);
+}
+
+static void none_clear(struct rxrpc_connection *conn)
+{
+}
+
+static int none_init(void)
+{
+	return 0;
+}
+
+static void none_exit(void)
+{
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxrpc_no_security = {
+	.name				= "none",
+	.security_index			= RXRPC_SECURITY_NONE,
+	.init				= none_init,
+	.exit				= none_exit,
+	.init_connection_security	= none_init_connection_security,
+	.free_call_crypto		= none_free_call_crypto,
+	.alloc_txbuf			= none_alloc_txbuf,
+	.secure_packet			= none_secure_packet,
+	.verify_packet			= none_verify_packet,
+	.validate_challenge		= none_validate_challenge,
+	.sendmsg_respond_to_challenge	= none_sendmsg_respond_to_challenge,
+	.verify_response		= none_verify_response,
+	.clear				= none_clear,
+};
diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c
new file mode 100644
index 000000000..dc5184a2f
--- /dev/null
+++ b/net/rxrpc/io_thread.c
@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC packet reception
+ *
+ * Copyright (C) 2007, 2016, 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ar-internal.h"
+
+static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
+				      struct sockaddr_rxrpc *peer_srx,
+				      struct sk_buff *skb);
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ *
+ * [!] Note that as this is called from the encap_rcv hook, the socket is not
+ * held locked by the caller and nothing prevents sk_user_data on the UDP from
+ * being cleared in the middle of processing this function.
+ *
+ * Called with the RCU read lock held from the IP layer via UDP.
+ */
+int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
+{
+	struct sk_buff_head *rx_queue;
+	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
+	struct task_struct *io_thread;
+
+	if (unlikely(!local)) {
+		kfree_skb(skb);
+		return 0;
+	}
+	io_thread = READ_ONCE(local->io_thread);
+	if (!io_thread) {
+		kfree_skb(skb);
+		return 0;
+	}
+	if (skb->tstamp == 0)
+		skb->tstamp = ktime_get_real();
+
+	skb->mark = RXRPC_SKB_MARK_PACKET;
+	rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv);
+	rx_queue = &local->rx_queue;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	if (rxrpc_inject_rx_delay ||
+	    !skb_queue_empty(&local->rx_delay_queue)) {
+		skb->tstamp = ktime_add_ms(skb->tstamp, rxrpc_inject_rx_delay);
+		rx_queue = &local->rx_delay_queue;
+	}
+#endif
+
+	skb_queue_tail(rx_queue, skb);
+	wake_up_process(io_thread);
+	return 0;
+}
+
+/*
+ * Handle an error received on the local endpoint.
+ */
+void rxrpc_error_report(struct sock *sk)
+{
+	struct rxrpc_local *local;
+	struct sk_buff *skb;
+
+	rcu_read_lock();
+	local = rcu_dereference_sk_user_data(sk);
+	if (unlikely(!local)) {
+		rcu_read_unlock();
+		return;
+	}
+
+	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
+		skb->mark = RXRPC_SKB_MARK_ERROR;
+		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
+		skb_queue_tail(&local->rx_queue, skb);
+	}
+
+	rxrpc_wake_up_io_thread(local);
+	rcu_read_unlock();
+}
+
+/*
+ * Directly produce an abort from a packet.
+ */
+bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			s32 abort_code, int err)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+			  abort_code, err);
+	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
+	skb->priority = abort_code;
+	return false;
+}
+
+/*
+ * Directly produce a connection abort from a packet.
+ */
+bool rxrpc_direct_conn_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
+			     s32 abort_code, int err)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	trace_rxrpc_abort(0, why, sp->hdr.cid, 0, sp->hdr.seq, abort_code, err);
+	skb->mark = RXRPC_SKB_MARK_REJECT_CONN_ABORT;
+	skb->priority = abort_code;
+	return false;
+}
+
+static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
+{
+	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
+}
+
+#define just_discard true
+
+/*
+ * Process event packets targeted at a local endpoint.
+ */
+static bool rxrpc_input_version(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	char v;
+
+	_enter("");
+
+	rxrpc_see_skb(skb, rxrpc_skb_see_version);
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), &v, 1) >= 0) {
+		if (v == 0)
+			rxrpc_send_version_request(local, &sp->hdr, skb);
+	}
+
+	return true;
+}
+
+/*
+ * Extract the wire header from a packet and translate the byte order.
+ */
+static bool rxrpc_extract_header(struct rxrpc_skb_priv *sp,
+				 struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_ackpacket ack;
+
+	/* dig out the RxRPC connection details */
+	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
+		return rxrpc_bad_message(skb, rxrpc_badmsg_short_hdr);
+
+	memset(sp, 0, sizeof(*sp));
+	sp->hdr.epoch		= ntohl(whdr.epoch);
+	sp->hdr.cid		= ntohl(whdr.cid);
+	sp->hdr.callNumber	= ntohl(whdr.callNumber);
+	sp->hdr.seq		= ntohl(whdr.seq);
+	sp->hdr.serial		= ntohl(whdr.serial);
+	sp->hdr.flags		= whdr.flags;
+	sp->hdr.type		= whdr.type;
+	sp->hdr.userStatus	= whdr.userStatus;
+	sp->hdr.securityIndex	= whdr.securityIndex;
+	sp->hdr._rsvd		= ntohs(whdr._rsvd);
+	sp->hdr.serviceId	= ntohs(whdr.serviceId);
+
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
+		if (skb_copy_bits(skb, sizeof(whdr), &ack, sizeof(ack)) < 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_short_ack);
+		sp->ack.first_ack	= ntohl(ack.firstPacket);
+		sp->ack.prev_ack	= ntohl(ack.previousPacket);
+		sp->ack.acked_serial	= ntohl(ack.serial);
+		sp->ack.reason		= ack.reason;
+		sp->ack.nr_acks		= ack.nAcks;
+	}
+	return true;
+}
+
+/*
+ * Extract the abort code from an ABORT packet and stash it in skb->priority.
+ */
+static bool rxrpc_extract_abort(struct sk_buff *skb)
+{
+	__be32 wtmp;
+
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &wtmp, sizeof(wtmp)) < 0)
+		return false;
+	skb->priority = ntohl(wtmp);
+	return true;
+}
+
+/*
+ * Process packets received on the local endpoint
+ */
+static bool rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	struct rxrpc_connection *conn;
+	struct sockaddr_rxrpc peer_srx;
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_peer *peer = NULL;
+	bool ret = false;
+
+	skb_pull(skb, sizeof(struct udphdr));
+
+	sp = rxrpc_skb(skb);
+
+	/* dig out the RxRPC connection details */
+	if (!rxrpc_extract_header(sp, skb))
+		return just_discard;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+		static int lose;
+		if ((lose++ & 7) == 7) {
+			trace_rxrpc_rx_lose(sp);
+			return just_discard;
+		}
+	}
+
+	trace_rxrpc_rx_packet(sp);
+
+	switch (sp->hdr.type) {
+	case RXRPC_PACKET_TYPE_VERSION:
+		if (rxrpc_to_client(sp))
+			return just_discard;
+		return rxrpc_input_version(local, skb);
+
+	case RXRPC_PACKET_TYPE_BUSY:
+		if (rxrpc_to_server(sp))
+			return just_discard;
+		fallthrough;
+	case RXRPC_PACKET_TYPE_ACK:
+	case RXRPC_PACKET_TYPE_ACKALL:
+		if (sp->hdr.callNumber == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
+		break;
+	case RXRPC_PACKET_TYPE_ABORT:
+		if (!rxrpc_extract_abort(skb))
+			return just_discard; /* Just discard if malformed */
+		break;
+
+	case RXRPC_PACKET_TYPE_DATA:
+		if (sp->hdr.callNumber == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
+		if (sp->hdr.seq == 0)
+			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_seq);
+		break;
+
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+		if (rxrpc_to_server(sp))
+			return just_discard;
+		break;
+	case RXRPC_PACKET_TYPE_RESPONSE:
+		if (rxrpc_to_client(sp))
+			return just_discard;
+		break;
+
+		/* Packet types 9-11 should just be ignored. */
+	case RXRPC_PACKET_TYPE_PARAMS:
+	case RXRPC_PACKET_TYPE_10:
+	case RXRPC_PACKET_TYPE_11:
+		return just_discard;
+
+	default:
+		return rxrpc_bad_message(skb, rxrpc_badmsg_unsupported_packet);
+	}
+
+	if (sp->hdr.serviceId == 0)
+		return rxrpc_bad_message(skb, rxrpc_badmsg_zero_service);
+
+	if (WARN_ON_ONCE(rxrpc_extract_addr_from_skb(&peer_srx, skb) < 0))
+		return just_discard; /* Unsupported address type. */
+
+	if (peer_srx.transport.family != local->srx.transport.family &&
+	    (peer_srx.transport.family == AF_INET &&
+	     local->srx.transport.family != AF_INET6)) {
+		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
+				    peer_srx.transport.family,
+				    local->srx.transport.family);
+		return just_discard; /* Wrong address type. */
+	}
+
+	if (rxrpc_to_client(sp)) {
+		rcu_read_lock();
+		conn = rxrpc_find_client_connection_rcu(local, &peer_srx, skb);
+		conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
+		rcu_read_unlock();
+		if (!conn)
+			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_conn);
+
+		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
+		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
+		return ret;
+	}
+
+	/* We need to look up service connections by the full protocol
+	 * parameter set.  We look up the peer first as an intermediate step
+	 * and then the connection from the peer's tree.
+	 */
+	rcu_read_lock();
+
+	peer = rxrpc_lookup_peer_rcu(local, &peer_srx);
+	if (!peer) {
+		rcu_read_unlock();
+		return rxrpc_new_incoming_call(local, NULL, NULL, &peer_srx, skb);
+	}
+
+	conn = rxrpc_find_service_conn_rcu(peer, skb);
+	conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
+	if (conn) {
+		rcu_read_unlock();
+		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
+		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
+		return ret;
+	}
+
+	peer = rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input);
+	rcu_read_unlock();
+
+	ret = rxrpc_new_incoming_call(local, peer, NULL, &peer_srx, skb);
+	rxrpc_put_peer(peer, rxrpc_peer_put_input);
+	return ret;
+}
+
+/*
+ * Deal with a packet that's associated with an extant connection.
+ */
+static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
+				      struct sockaddr_rxrpc *peer_srx,
+				      struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_channel *chan;
+	struct rxrpc_call *call = NULL;
+	unsigned int channel;
+
+	if (sp->hdr.securityIndex != conn->security_ix)
+		return rxrpc_direct_abort(skb, rxrpc_eproto_wrong_security,
+					  RXKADINCONSISTENCY, -EBADMSG);
+
+	if (sp->hdr.serviceId != conn->service_id) {
+		int old_id;
+
+		if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
+			return rxrpc_protocol_error(skb, rxrpc_eproto_reupgrade);
+
+		old_id = cmpxchg(&conn->service_id, conn->orig_service_id,
+				 sp->hdr.serviceId);
+		if (old_id != conn->orig_service_id &&
+		    old_id != sp->hdr.serviceId)
+			return rxrpc_protocol_error(skb, rxrpc_eproto_bad_upgrade);
+	}
+
+	if (after(sp->hdr.serial, conn->hi_serial))
+		conn->hi_serial = sp->hdr.serial;
+
+	/* It's a connection-level packet if the call number is 0. */
+	if (sp->hdr.callNumber == 0)
+		return rxrpc_input_conn_packet(conn, skb);
+
+	/* Deal with path MTU discovery probing. */
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_ACK &&
+	    conn->pmtud_probe &&
+	    after_eq(sp->ack.acked_serial, conn->pmtud_probe))
+		rxrpc_input_probe_for_pmtud(conn, sp->ack.acked_serial, false);
+
+	/* Call-bound packets are routed by connection channel. */
+	channel = sp->hdr.cid & RXRPC_CHANNELMASK;
+	chan = &conn->channels[channel];
+
+	/* Ignore really old calls */
+	if (sp->hdr.callNumber < chan->last_call)
+		return just_discard;
+
+	if (sp->hdr.callNumber == chan->last_call) {
+		if (chan->call ||
+		    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+			return just_discard;
+
+		/* For the previous service call, if completed successfully, we
+		 * discard all further packets.
+		 */
+		if (rxrpc_conn_is_service(conn) &&
+		    chan->last_type == RXRPC_PACKET_TYPE_ACK)
+			return just_discard;
+
+		/* But otherwise we need to retransmit the final packet from
+		 * data cached in the connection record.
+		 */
+		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
+			trace_rxrpc_rx_data(chan->call_debug_id,
+					    sp->hdr.seq,
+					    sp->hdr.serial,
+					    sp->hdr.flags);
+		rxrpc_conn_retransmit_call(conn, skb, channel);
+		return just_discard;
+	}
+
+	call = rxrpc_try_get_call(chan->call, rxrpc_call_get_input);
+
+	if (sp->hdr.callNumber > chan->call_id) {
+		if (rxrpc_to_client(sp)) {
+			if (call)
+				rxrpc_put_call(call, rxrpc_call_put_input);
+			return rxrpc_protocol_error(skb,
+						    rxrpc_eproto_unexpected_implicit_end);
+		}
+
+		if (call) {
+			rxrpc_implicit_end_call(call, skb);
+			rxrpc_put_call(call, rxrpc_call_put_input);
+			call = NULL;
+		}
+	}
+
+	if (!call) {
+		if (rxrpc_to_client(sp))
+			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_call);
+		return rxrpc_new_incoming_call(conn->local, conn->peer, conn,
+					       peer_srx, skb);
+	}
+
+	rxrpc_queue_rx_call_packet(call, skb);
+	rxrpc_put_call(call, rxrpc_call_put_input);
+	return true;
+}
+
+/*
+ * I/O and event handling thread.
+ */
+int rxrpc_io_thread(void *data)
+{
+	struct rxrpc_connection *conn;
+	struct sk_buff_head rx_queue;
+	struct rxrpc_local *local = data;
+	struct rxrpc_call *call;
+	struct sk_buff *skb;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	ktime_t now;
+#endif
+	bool should_stop;
+	LIST_HEAD(conn_attend_q);
+	LIST_HEAD(call_attend_q);
+
+	complete(&local->io_thread_ready);
+
+	skb_queue_head_init(&rx_queue);
+
+	set_user_nice(current, MIN_NICE);
+
+	for (;;) {
+		rxrpc_inc_stat(local->rxnet, stat_io_loop);
+
+		/* Inject a delay into packets if requested. */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+		now = ktime_get_real();
+		while ((skb = skb_peek(&local->rx_delay_queue))) {
+			if (ktime_before(now, skb->tstamp))
+				break;
+			skb = skb_dequeue(&local->rx_delay_queue);
+			skb_queue_tail(&local->rx_queue, skb);
+		}
+#endif
+
+		if (!skb_queue_empty(&local->rx_queue)) {
+			spin_lock_irq(&local->rx_queue.lock);
+			skb_queue_splice_tail_init(&local->rx_queue, &rx_queue);
+			spin_unlock_irq(&local->rx_queue.lock);
+			trace_rxrpc_iothread_rx(local, skb_queue_len(&rx_queue));
+		}
+
+		/* Distribute packets and errors. */
+		while ((skb = __skb_dequeue(&rx_queue))) {
+			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+			switch (skb->mark) {
+			case RXRPC_SKB_MARK_PACKET:
+				skb->priority = 0;
+				if (!rxrpc_input_packet(local, skb))
+					rxrpc_reject_packet(local, skb);
+				trace_rxrpc_rx_done(skb->mark, skb->priority);
+				rxrpc_free_skb(skb, rxrpc_skb_put_input);
+				break;
+			case RXRPC_SKB_MARK_ERROR:
+				rxrpc_input_error(local, skb);
+				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
+				break;
+			case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
+				rxrpc_input_conn_event(sp->poke_conn, skb);
+				rxrpc_put_connection(sp->poke_conn, rxrpc_conn_put_poke);
+				rxrpc_free_skb(skb, rxrpc_skb_put_conn_secured);
+				break;
+			default:
+				WARN_ON_ONCE(1);
+				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);
+				break;
+			}
+		}
+
+		/* Deal with connections that want immediate attention. */
+		if (!list_empty_careful(&local->conn_attend_q)) {
+			spin_lock_irq(&local->lock);
+			list_splice_tail_init(&local->conn_attend_q, &conn_attend_q);
+			spin_unlock_irq(&local->lock);
+		}
+
+		while ((conn = list_first_entry_or_null(&conn_attend_q,
+							struct rxrpc_connection,
+							attend_link))) {
+			spin_lock_irq(&local->lock);
+			list_del_init(&conn->attend_link);
+			spin_unlock_irq(&local->lock);
+			rxrpc_input_conn_event(conn, NULL);
+			rxrpc_put_connection(conn, rxrpc_conn_put_poke);
+		}
+
+		if (test_and_clear_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
+				       &local->client_conn_flags))
+			rxrpc_discard_expired_client_conns(local);
+
+		/* Deal with calls that want immediate attention. */
+		spin_lock_irq(&local->lock);
+		list_splice_tail_init(&local->call_attend_q, &call_attend_q);
+		spin_unlock_irq(&local->lock);
+
+		while ((call = list_first_entry_or_null(&call_attend_q,
+							struct rxrpc_call,
+							attend_link))) {
+			spin_lock_irq(&local->lock);
+			list_del_init(&call->attend_link);
+			spin_unlock_irq(&local->lock);
+			trace_rxrpc_call_poked(call);
+			rxrpc_input_call_event(call);
+			rxrpc_put_call(call, rxrpc_call_put_poke);
+		}
+
+		if (!list_empty(&local->new_client_calls))
+			rxrpc_connect_client_calls(local);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		should_stop = kthread_should_stop();
+		if (!skb_queue_empty(&local->rx_queue) ||
+		    !list_empty(&local->call_attend_q) ||
+		    !list_empty(&local->conn_attend_q) ||
+		    !list_empty(&local->new_client_calls) ||
+		    test_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
+			     &local->client_conn_flags)) {
+			__set_current_state(TASK_RUNNING);
+			continue;
+		}
+
+		if (should_stop)
+			break;
+
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+		skb = skb_peek(&local->rx_delay_queue);
+		if (skb) {
+			unsigned long timeout;
+			ktime_t tstamp = skb->tstamp;
+			ktime_t now = ktime_get_real();
+			s64 delay_ns = ktime_to_ns(ktime_sub(tstamp, now));
+
+			if (delay_ns <= 0) {
+				__set_current_state(TASK_RUNNING);
+				continue;
+			}
+
+			timeout = nsecs_to_jiffies(delay_ns);
+			timeout = umax(timeout, 1);
+			schedule_timeout(timeout);
+			__set_current_state(TASK_RUNNING);
+			continue;
+		}
+#endif
+
+		schedule();
+	}
+
+	__set_current_state(TASK_RUNNING);
+	rxrpc_see_local(local, rxrpc_local_stop);
+	rxrpc_destroy_local(local);
+	WRITE_ONCE(local->io_thread, NULL);
+	rxrpc_see_local(local, rxrpc_local_stopped);
+	return 0;
+}
diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
new file mode 100644
index 000000000..cbd26da44
--- /dev/null
+++ b/net/rxrpc/key.c
@@ -0,0 +1,895 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *	"afs@example.com"
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/overflow.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_preparse(struct key_preparsed_payload *);
+static void rxrpc_free_preparse(struct key_preparsed_payload *);
+static void rxrpc_destroy(struct key *);
+static void rxrpc_describe(const struct key *, struct seq_file *);
+static long rxrpc_read(const struct key *, char *, size_t);
+
+/*
+ * rxrpc defined keys take an arbitrary string as the description and an
+ * arbitrary blob of data as the payload
+ */
+struct key_type key_type_rxrpc = {
+	.name		= "rxrpc",
+	.flags		= KEY_TYPE_NET_DOMAIN,
+	.preparse	= rxrpc_preparse,
+	.free_preparse	= rxrpc_free_preparse,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy,
+	.describe	= rxrpc_describe,
+	.read		= rxrpc_read,
+};
+EXPORT_SYMBOL(key_type_rxrpc);
+
+/*
+ * parse an RxKAD type XDR format token
+ * - the caller guarantees we have at least 4 words
+ */
+static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
+				    size_t datalen,
+				    const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	time64_t expiry;
+	size_t plen;
+	u32 tktlen;
+
+	_enter(",{%x,%x,%x,%x},%u",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	if (toklen <= 8 * 4)
+		return -EKEYREJECTED;
+	tktlen = ntohl(xdr[7]);
+	_debug("tktlen: %x", tktlen);
+	if (tktlen > AFSTOKEN_RK_TIX_MAX)
+		return -EKEYREJECTED;
+	if (toklen < 8 * 4 + tktlen)
+		return -EKEYREJECTED;
+
+	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
+	prep->quotalen += datalen + plen;
+
+	plen -= sizeof(*token);
+	token = kzalloc_obj(*token);
+	if (!token)
+		return -ENOMEM;
+
+	token->kad = kzalloc(plen, GFP_KERNEL);
+	if (!token->kad) {
+		kfree(token);
+		return -ENOMEM;
+	}
+
+	token->security_index	= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len	= tktlen;
+	token->kad->vice_id	= ntohl(xdr[0]);
+	token->kad->kvno	= ntohl(xdr[1]);
+	token->kad->start	= ntohl(xdr[4]);
+	token->kad->expiry	= ntohl(xdr[5]);
+	token->kad->primary_flag = ntohl(xdr[6]);
+	memcpy(&token->kad->session_key, &xdr[2], 8);
+	memcpy(&token->kad->ticket, &xdr[8], tktlen);
+
+	_debug("SCIX: %u", token->security_index);
+	_debug("TLEN: %u", token->kad->ticket_len);
+	_debug("EXPY: %x", token->kad->expiry);
+	_debug("KVNO: %u", token->kad->kvno);
+	_debug("PRIM: %u", token->kad->primary_flag);
+	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+	       token->kad->session_key[0], token->kad->session_key[1],
+	       token->kad->session_key[2], token->kad->session_key[3],
+	       token->kad->session_key[4], token->kad->session_key[5],
+	       token->kad->session_key[6], token->kad->session_key[7]);
+	if (token->kad->ticket_len >= 8)
+		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+		       token->kad->ticket[0], token->kad->ticket[1],
+		       token->kad->ticket[2], token->kad->ticket[3],
+		       token->kad->ticket[4], token->kad->ticket[5],
+		       token->kad->ticket[6], token->kad->ticket[7]);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+
+	_leave(" = 0");
+	return 0;
+}
+
+static u64 xdr_dec64(const __be32 *xdr)
+{
+	return (u64)ntohl(xdr[0]) << 32 | (u64)ntohl(xdr[1]);
+}
+
+static time64_t rxrpc_s64_to_time64(s64 time_in_100ns)
+{
+	bool neg = false;
+	u64 tmp = time_in_100ns;
+
+	if (time_in_100ns < 0) {
+		tmp = -time_in_100ns;
+		neg = true;
+	}
+	do_div(tmp, 10000000);
+	return neg ? -tmp : tmp;
+}
+
+/*
+ * Parse a YFS-RxGK type XDR format token
+ * - the caller guarantees we have at least 4 words
+ *
+ * struct token_rxgk {
+ *	opr_time begintime;
+ *	opr_time endtime;
+ *	afs_int64 level;
+ *	afs_int64 lifetime;
+ *	afs_int64 bytelife;
+ *	afs_int64 enctype;
+ *	opaque key<>;
+ *	opaque ticket<>;
+ * };
+ */
+static int rxrpc_preparse_xdr_yfs_rxgk(struct key_preparsed_payload *prep,
+				       size_t datalen,
+				       const __be32 *xdr, unsigned int toklen)
+{
+	struct rxrpc_key_token *token, **pptoken;
+	time64_t expiry;
+	size_t plen;
+	const __be32 *ticket, *key;
+	s64 tmp;
+	size_t raw_keylen, raw_tktlen, keylen, tktlen;
+
+	_enter(",{%x,%x,%x,%x},%x",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       toklen);
+
+	if (6 * 2 + 2 > toklen / 4)
+		goto reject;
+
+	key = xdr + (6 * 2 + 1);
+	raw_keylen = ntohl(key[-1]);
+	_debug("keylen: %zx", raw_keylen);
+	if (raw_keylen > AFSTOKEN_GK_KEY_MAX)
+		goto reject;
+	keylen = round_up(raw_keylen, 4);
+	if ((6 * 2 + 2) * 4 + keylen > toklen)
+		goto reject;
+
+	ticket = xdr + (6 * 2 + 1 + (keylen / 4) + 1);
+	raw_tktlen = ntohl(ticket[-1]);
+	_debug("tktlen: %zx", raw_tktlen);
+	if (raw_tktlen > AFSTOKEN_GK_TOKEN_MAX)
+		goto reject;
+	tktlen = round_up(raw_tktlen, 4);
+	if ((6 * 2 + 2) * 4 + keylen + tktlen != toklen) {
+		kleave(" = -EKEYREJECTED [%zx!=%x, %zx,%zx]",
+		       (6 * 2 + 2) * 4 + keylen + tktlen, toklen,
+		       keylen, tktlen);
+		goto reject;
+	}
+
+	plen = sizeof(*token) + sizeof(*token->rxgk) + tktlen + keylen;
+	prep->quotalen += datalen + plen;
+
+	plen -= sizeof(*token);
+	token = kzalloc_obj(*token);
+	if (!token)
+		goto nomem;
+
+	token->rxgk = kzalloc_flex(struct rxgk_key, _key, raw_keylen);
+	if (!token->rxgk)
+		goto nomem_token;
+
+	token->security_index	= RXRPC_SECURITY_YFS_RXGK;
+	token->rxgk->begintime	= xdr_dec64(xdr + 0 * 2);
+	token->rxgk->endtime	= xdr_dec64(xdr + 1 * 2);
+	token->rxgk->level	= tmp = xdr_dec64(xdr + 2 * 2);
+	if (tmp < -1LL || tmp > RXRPC_SECURITY_ENCRYPT)
+		goto reject_token;
+	token->rxgk->lifetime	= xdr_dec64(xdr + 3 * 2);
+	token->rxgk->bytelife	= xdr_dec64(xdr + 4 * 2);
+	token->rxgk->enctype	= tmp = xdr_dec64(xdr + 5 * 2);
+	if (tmp < 0 || tmp > UINT_MAX)
+		goto reject_token;
+	token->rxgk->key.len	= raw_keylen;
+	token->rxgk->key.data	= token->rxgk->_key;
+	token->rxgk->ticket.len = raw_tktlen;
+
+	if (token->rxgk->endtime != 0) {
+		expiry = rxrpc_s64_to_time64(token->rxgk->endtime);
+		if (expiry < 0)
+			goto expired;
+		if (expiry < prep->expiry)
+			prep->expiry = expiry;
+	}
+
+	memcpy(token->rxgk->key.data, key, token->rxgk->key.len);
+
+	/* Pad the ticket so that we can use it directly in XDR */
+	token->rxgk->ticket.data = kzalloc(tktlen, GFP_KERNEL);
+	if (!token->rxgk->ticket.data)
+		goto nomem_yrxgk;
+	memcpy(token->rxgk->ticket.data, ticket, token->rxgk->ticket.len);
+
+	_debug("SCIX: %u",	token->security_index);
+	_debug("EXPY: %llx",	token->rxgk->endtime);
+	_debug("LIFE: %llx",	token->rxgk->lifetime);
+	_debug("BYTE: %llx",	token->rxgk->bytelife);
+	_debug("ENC : %u",	token->rxgk->enctype);
+	_debug("LEVL: %u",	token->rxgk->level);
+	_debug("KLEN: %u",	token->rxgk->key.len);
+	_debug("TLEN: %u",	token->rxgk->ticket.len);
+	_debug("KEY0: %*phN",	token->rxgk->key.len, token->rxgk->key.data);
+	_debug("TICK: %*phN",
+	       min_t(u32, token->rxgk->ticket.len, 32), token->rxgk->ticket.data);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	for (pptoken = (struct rxrpc_key_token **)&prep->payload.data[0];
+	     *pptoken;
+	     pptoken = &(*pptoken)->next)
+		continue;
+	*pptoken = token;
+
+	_leave(" = 0");
+	return 0;
+
+nomem_yrxgk:
+	kfree(token->rxgk);
+nomem_token:
+	kfree(token);
+nomem:
+	return -ENOMEM;
+reject_token:
+	kfree(token->rxgk);
+	kfree(token);
+reject:
+	return -EKEYREJECTED;
+expired:
+	kfree(token->rxgk);
+	kfree(token);
+	return -EKEYEXPIRED;
+}
+
+/*
+ * attempt to parse the data as the XDR format
+ * - the caller guarantees we have more than 7 words
+ */
+static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
+{
+	const __be32 *xdr = prep->data, *token, *p;
+	const char *cp;
+	unsigned int len, paddedlen, loop, ntoken, toklen, sec_ix;
+	size_t datalen = prep->datalen;
+	int ret, ret2;
+
+	_enter(",{%x,%x,%x,%x},%zu",
+	       ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
+	       prep->datalen);
+
+	if (datalen > AFSTOKEN_LENGTH_MAX)
+		goto not_xdr;
+
+	/* XDR is an array of __be32's */
+	if (datalen & 3)
+		goto not_xdr;
+
+	/* the flags should be 0 (the setpag bit must be handled by
+	 * userspace) */
+	if (ntohl(*xdr++) != 0)
+		goto not_xdr;
+	datalen -= 4;
+
+	/* check the cell name */
+	len = ntohl(*xdr++);
+	if (len < 1 || len > AFSTOKEN_CELL_MAX)
+		goto not_xdr;
+	datalen -= 4;
+	paddedlen = (len + 3) & ~3;
+	if (paddedlen > datalen)
+		goto not_xdr;
+
+	cp = (const char *) xdr;
+	for (loop = 0; loop < len; loop++)
+		if (!isprint(cp[loop]))
+			goto not_xdr;
+	for (; loop < paddedlen; loop++)
+		if (cp[loop])
+			goto not_xdr;
+	_debug("cellname: [%u/%u] '%*.*s'",
+	       len, paddedlen, len, len, (const char *) xdr);
+	datalen -= paddedlen;
+	xdr += paddedlen >> 2;
+
+	/* get the token count */
+	if (datalen < 12)
+		goto not_xdr;
+	ntoken = ntohl(*xdr++);
+	datalen -= 4;
+	_debug("ntoken: %x", ntoken);
+	if (ntoken < 1 || ntoken > AFSTOKEN_MAX)
+		goto not_xdr;
+
+	/* check each token wrapper */
+	p = xdr;
+	loop = ntoken;
+	do {
+		if (datalen < 8)
+			goto not_xdr;
+		toklen = ntohl(*p++);
+		sec_ix = ntohl(*p);
+		datalen -= 4;
+		_debug("token: [%x/%zx] %x", toklen, datalen, sec_ix);
+		paddedlen = (toklen + 3) & ~3;
+		if (toklen < 20 || toklen > datalen || paddedlen > datalen)
+			goto not_xdr;
+		datalen -= paddedlen;
+		p += paddedlen >> 2;
+
+	} while (--loop > 0);
+
+	_debug("remainder: %zu", datalen);
+	if (datalen != 0)
+		goto not_xdr;
+
+	/* okay: we're going to assume it's valid XDR format
+	 * - we ignore the cellname, relying on the key to be correctly named
+	 */
+	ret = -EPROTONOSUPPORT;
+	do {
+		toklen = ntohl(*xdr++);
+		token = xdr;
+		xdr += (toklen + 3) / 4;
+
+		sec_ix = ntohl(*token++);
+		toklen -= 4;
+
+		_debug("TOKEN type=%x len=%x", sec_ix, toklen);
+
+		switch (sec_ix) {
+		case RXRPC_SECURITY_RXKAD:
+			ret2 = rxrpc_preparse_xdr_rxkad(prep, datalen, token, toklen);
+			break;
+		case RXRPC_SECURITY_YFS_RXGK:
+			ret2 = rxrpc_preparse_xdr_yfs_rxgk(prep, datalen, token, toklen);
+			break;
+		default:
+			ret2 = -EPROTONOSUPPORT;
+			break;
+		}
+
+		switch (ret2) {
+		case 0:
+			ret = 0;
+			break;
+		case -EPROTONOSUPPORT:
+			break;
+		case -ENOPKG:
+			if (ret != 0)
+				ret = -ENOPKG;
+			break;
+		default:
+			ret = ret2;
+			goto error;
+		}
+
+	} while (--ntoken > 0);
+
+error:
+	_leave(" = %d", ret);
+	return ret;
+
+not_xdr:
+	_leave(" = -EPROTO");
+	return -EPROTO;
+}
+
+/*
+ * Preparse an rxrpc defined key.
+ *
+ * Data should be of the form:
+ *	OFFSET	LEN	CONTENT
+ *	0	4	key interface version number
+ *	4	2	security index (type)
+ *	6	2	ticket length
+ *	8	4	key expiry time (time_t)
+ *	12	4	kvno
+ *	16	8	session key
+ *	24	[len]	ticket
+ *
+ * if no data is provided, then a no-security key is made
+ */
+static int rxrpc_preparse(struct key_preparsed_payload *prep)
+{
+	const struct rxrpc_key_data_v1 *v1;
+	struct rxrpc_key_token *token, **pp;
+	time64_t expiry;
+	size_t plen;
+	u32 kver;
+	int ret;
+
+	_enter("%zu", prep->datalen);
+
+	/* handle a no-security key */
+	if (!prep->data && prep->datalen == 0)
+		return 0;
+
+	/* determine if the XDR payload format is being used */
+	if (prep->datalen > 7 * 4) {
+		ret = rxrpc_preparse_xdr(prep);
+		if (ret != -EPROTO)
+			return ret;
+	}
+
+	/* get the key interface version number */
+	ret = -EINVAL;
+	if (prep->datalen <= 4 || !prep->data)
+		goto error;
+	memcpy(&kver, prep->data, sizeof(kver));
+	prep->data += sizeof(kver);
+	prep->datalen -= sizeof(kver);
+	prep->quotalen = 0;
+
+	_debug("KEY I/F VERSION: %u", kver);
+
+	ret = -EKEYREJECTED;
+	if (kver != 1)
+		goto error;
+
+	/* deal with a version 1 key */
+	ret = -EINVAL;
+	if (prep->datalen < sizeof(*v1))
+		goto error;
+
+	v1 = prep->data;
+	if (prep->datalen != sizeof(*v1) + v1->ticket_length)
+		goto error;
+
+	_debug("SCIX: %u", v1->security_index);
+	_debug("TLEN: %u", v1->ticket_length);
+	_debug("EXPY: %x", v1->expiry);
+	_debug("KVNO: %u", v1->kvno);
+	_debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
+	       v1->session_key[0], v1->session_key[1],
+	       v1->session_key[2], v1->session_key[3],
+	       v1->session_key[4], v1->session_key[5],
+	       v1->session_key[6], v1->session_key[7]);
+	if (v1->ticket_length >= 8)
+		_debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
+		       v1->ticket[0], v1->ticket[1],
+		       v1->ticket[2], v1->ticket[3],
+		       v1->ticket[4], v1->ticket[5],
+		       v1->ticket[6], v1->ticket[7]);
+
+	ret = -EPROTONOSUPPORT;
+	if (v1->security_index != RXRPC_SECURITY_RXKAD)
+		goto error;
+
+	ret = -EKEYREJECTED;
+	if (v1->ticket_length > AFSTOKEN_RK_TIX_MAX)
+		goto error;
+
+	plen = sizeof(*token->kad) + v1->ticket_length;
+	prep->quotalen += plen + sizeof(*token);
+
+	ret = -ENOMEM;
+	token = kzalloc_obj(*token);
+	if (!token)
+		goto error;
+	token->kad = kzalloc(plen, GFP_KERNEL);
+	if (!token->kad)
+		goto error_free;
+
+	token->security_index		= RXRPC_SECURITY_RXKAD;
+	token->kad->ticket_len		= v1->ticket_length;
+	token->kad->expiry		= v1->expiry;
+	token->kad->kvno		= v1->kvno;
+	memcpy(&token->kad->session_key, &v1->session_key, 8);
+	memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);
+
+	/* count the number of tokens attached */
+	prep->payload.data[1] = (void *)((unsigned long)prep->payload.data[1] + 1);
+
+	/* attach the data */
+	pp = (struct rxrpc_key_token **)&prep->payload.data[0];
+	while (*pp)
+		pp = &(*pp)->next;
+	*pp = token;
+	expiry = rxrpc_u32_to_time64(token->kad->expiry);
+	if (expiry < prep->expiry)
+		prep->expiry = expiry;
+	token = NULL;
+	ret = 0;
+
+error_free:
+	kfree(token);
+error:
+	return ret;
+}
+
+/*
+ * Free token list.
+ */
+static void rxrpc_free_token_list(struct rxrpc_key_token *token)
+{
+	struct rxrpc_key_token *next;
+
+	for (; token; token = next) {
+		next = token->next;
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			kfree(token->kad);
+			break;
+		case RXRPC_SECURITY_YFS_RXGK:
+			kfree(token->rxgk->ticket.data);
+			kfree(token->rxgk);
+			break;
+		default:
+			pr_err("Unknown token type %x on rxrpc key\n",
+			       token->security_index);
+			BUG();
+		}
+
+		kfree(token);
+	}
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
+{
+	rxrpc_free_token_list(prep->payload.data[0]);
+}
+
+/*
+ * dispose of the data dangling from the corpse of a rxrpc key
+ */
+static void rxrpc_destroy(struct key *key)
+{
+	rxrpc_free_token_list(key->payload.data[0]);
+}
+
+/*
+ * describe the rxrpc key
+ */
+static void rxrpc_describe(const struct key *key, struct seq_file *m)
+{
+	const struct rxrpc_key_token *token;
+	const char *sep = ": ";
+
+	seq_puts(m, key->description);
+
+	for (token = key->payload.data[0]; token; token = token->next) {
+		seq_puts(m, sep);
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			seq_puts(m, "ka");
+			break;
+		case RXRPC_SECURITY_YFS_RXGK:
+			seq_puts(m, "ygk");
+			break;
+		default: /* we have a ticket we can't encode */
+			seq_printf(m, "%u", token->security_index);
+			break;
+		}
+
+		sep = " ";
+	}
+}
+
+/*
+ * grab the security key for a socket
+ */
+int rxrpc_request_key(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1 || rx->key)
+		return -EINVAL;
+
+	description = memdup_sockptr_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key_net(&key_type_rxrpc, description, sock_net(&rx->sk), NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->key = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/*
+ * generate a server data key
+ */
+int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
+			      const void *session_key,
+			      time64_t expiry,
+			      u32 kvno)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	struct {
+		u32 kver;
+		struct rxrpc_key_data_v1 v1;
+	} data;
+
+	_enter("");
+
+	key = key_alloc(&key_type_rxrpc, "x",
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0,
+			KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key)) {
+		_leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+		return -ENOMEM;
+	}
+
+	_debug("key %d", key_serial(key));
+
+	data.kver = 1;
+	data.v1.security_index = RXRPC_SECURITY_RXKAD;
+	data.v1.ticket_length = 0;
+	data.v1.expiry = rxrpc_time64_to_u32(expiry);
+	data.v1.kvno = 0;
+
+	memcpy(&data.v1.session_key, session_key, sizeof(data.v1.session_key));
+
+	ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
+	if (ret < 0)
+		goto error;
+
+	conn->key = key;
+	_leave(" = 0 [%d]", key_serial(key));
+	return 0;
+
+error:
+	key_revoke(key);
+	key_put(key);
+	_leave(" = -ENOMEM [ins %d]", ret);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL(rxrpc_get_server_data_key);
+
+/**
+ * rxrpc_get_null_key - Generate a null RxRPC key
+ * @keyname: The name to give the key.
+ *
+ * Generate a null RxRPC key that can be used to indicate anonymous security is
+ * required for a particular domain.
+ *
+ * Return: The new key or a negative error code.
+ */
+struct key *rxrpc_get_null_key(const char *keyname)
+{
+	const struct cred *cred = current_cred();
+	struct key *key;
+	int ret;
+
+	key = key_alloc(&key_type_rxrpc, keyname,
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
+			KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key))
+		return key;
+
+	ret = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
+	if (ret < 0) {
+		key_revoke(key);
+		key_put(key);
+		return ERR_PTR(ret);
+	}
+
+	return key;
+}
+EXPORT_SYMBOL(rxrpc_get_null_key);
+
+/*
+ * read the contents of an rxrpc key
+ * - this returns the result in XDR form
+ */
+static long rxrpc_read(const struct key *key,
+		       char *buffer, size_t buflen)
+{
+	const struct rxrpc_key_token *token;
+	size_t size;
+	__be32 *xdr, *oldxdr;
+	u32 cnlen, toksize, ntoks, tok, zero;
+	u16 toksizes[AFSTOKEN_MAX];
+
+	_enter("");
+
+	/* we don't know what form we should return non-AFS keys in */
+	if (memcmp(key->description, "afs@", 4) != 0)
+		return -EOPNOTSUPP;
+	cnlen = strlen(key->description + 4);
+
+#define RND(X) (((X) + 3) & ~3)
+
+	/* AFS keys we return in XDR form, so we need to work out the size of
+	 * the XDR */
+	size = 2 * 4;	/* flags, cellname len */
+	size += RND(cnlen);	/* cellname */
+	size += 1 * 4;	/* token count */
+
+	ntoks = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = 4;	/* sec index */
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			toksize += 8 * 4;	/* viceid, kvno, key*2, begin,
+						 * end, primary, tktlen */
+			if (!token->no_leak_key)
+				toksize += RND(token->kad->ticket_len);
+			break;
+
+		case RXRPC_SECURITY_YFS_RXGK:
+			toksize += 6 * 8 + 2 * 4;
+			if (!token->no_leak_key)
+				toksize += RND(token->rxgk->key.len);
+			toksize += RND(token->rxgk->ticket.len);
+			break;
+
+		default: /* we have a ticket we can't encode */
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		_debug("token[%u]: toksize=%u", ntoks, toksize);
+		if (WARN_ON(toksize > AFSTOKEN_LENGTH_MAX))
+			return -EIO;
+
+		toksizes[ntoks++] = toksize;
+		size += toksize + 4; /* each token has a length word */
+	}
+
+#undef RND
+
+	if (!buffer || buflen < size)
+		return size;
+
+	xdr = (__be32 *)buffer;
+	zero = 0;
+#define ENCODE(x)				\
+	do {					\
+		*xdr++ = htonl(x);		\
+	} while(0)
+#define ENCODE_DATA(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		ENCODE(l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE_BYTES(l, s)						\
+	do {								\
+		u32 _l = (l);						\
+		memcpy(xdr, (s), _l);					\
+		if (_l & 3)						\
+			memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3));	\
+		xdr += (_l + 3) >> 2;					\
+	} while(0)
+#define ENCODE64(x)					\
+	do {						\
+		__be64 y = cpu_to_be64(x);		\
+		memcpy(xdr, &y, 8);			\
+		xdr += 8 >> 2;				\
+	} while(0)
+#define ENCODE_STR(s)				\
+	do {					\
+		const char *_s = (s);		\
+		ENCODE_DATA(strlen(_s), _s);	\
+	} while(0)
+
+	ENCODE(0);					/* flags */
+	ENCODE_DATA(cnlen, key->description + 4);	/* cellname */
+	ENCODE(ntoks);
+
+	tok = 0;
+	for (token = key->payload.data[0]; token; token = token->next) {
+		toksize = toksizes[tok++];
+		ENCODE(toksize);
+		oldxdr = xdr;
+		ENCODE(token->security_index);
+
+		switch (token->security_index) {
+		case RXRPC_SECURITY_RXKAD:
+			ENCODE(token->kad->vice_id);
+			ENCODE(token->kad->kvno);
+			ENCODE_BYTES(8, token->kad->session_key);
+			ENCODE(token->kad->start);
+			ENCODE(token->kad->expiry);
+			ENCODE(token->kad->primary_flag);
+			if (token->no_leak_key)
+				ENCODE(0);
+			else
+				ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
+			break;
+
+		case RXRPC_SECURITY_YFS_RXGK:
+			ENCODE64(token->rxgk->begintime);
+			ENCODE64(token->rxgk->endtime);
+			ENCODE64(token->rxgk->level);
+			ENCODE64(token->rxgk->lifetime);
+			ENCODE64(token->rxgk->bytelife);
+			ENCODE64(token->rxgk->enctype);
+			if (token->no_leak_key)
+				ENCODE(0);
+			else
+				ENCODE_DATA(token->rxgk->key.len, token->rxgk->key.data);
+			ENCODE_DATA(token->rxgk->ticket.len, token->rxgk->ticket.data);
+			break;
+
+		default:
+			pr_err("Unsupported key token type (%u)\n",
+			       token->security_index);
+			return -ENOPKG;
+		}
+
+		if (WARN_ON((unsigned long)xdr - (unsigned long)oldxdr !=
+			    toksize))
+			return -EIO;
+	}
+
+#undef ENCODE_STR
+#undef ENCODE_DATA
+#undef ENCODE64
+#undef ENCODE
+
+	if (WARN_ON(tok != ntoks))
+		return -EIO;
+	if (WARN_ON((unsigned long)xdr - (unsigned long)buffer != size))
+		return -EIO;
+	_leave(" = %zu", size);
+	return size;
+}
diff --git a/net/rxrpc/local_event.c b/net/rxrpc/local_event.c
new file mode 100644
index 000000000..993c69f97
--- /dev/null
+++ b/net/rxrpc/local_event.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC local endpoint management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <generated/utsrelease.h>
+#include "ar-internal.h"
+
+static char rxrpc_version_string[65]; // "linux-" UTS_RELEASE " AF_RXRPC";
+
+/*
+ * Generate the VERSION packet string.
+ */
+void rxrpc_gen_version_string(void)
+{
+	snprintf(rxrpc_version_string, sizeof(rxrpc_version_string),
+		 "linux-%.49s AF_RXRPC", UTS_RELEASE);
+}
+
+/*
+ * Reply to a version request
+ */
+void rxrpc_send_version_request(struct rxrpc_local *local,
+				struct rxrpc_host_header *hdr,
+				struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct sockaddr_rxrpc srx;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	int ret;
+
+	_enter("");
+
+	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
+		return;
+
+	msg.msg_name	= &srx.transport;
+	msg.msg_namelen	= srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(sp->hdr.epoch);
+	whdr.cid	= htonl(sp->hdr.cid);
+	whdr.callNumber	= htonl(sp->hdr.callNumber);
+	whdr.seq	= 0;
+	whdr.serial	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_VERSION;
+	whdr.flags	= RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED);
+	whdr.userStatus	= 0;
+	whdr.securityIndex = 0;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(sp->hdr.serviceId);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= (char *)rxrpc_version_string;
+	iov[1].iov_len	= sizeof(rxrpc_version_string);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	ret = kernel_sendmsg(local->socket, &msg, iov, 2, len);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(local->debug_id, 0, ret,
+				    rxrpc_tx_point_version_reply);
+	else
+		trace_rxrpc_tx_packet(local->debug_id, &whdr,
+				      rxrpc_tx_point_version_reply);
+
+	_leave("");
+}
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
new file mode 100644
index 000000000..169f9dfda
--- /dev/null
+++ b/net/rxrpc/local_object.c
@@ -0,0 +1,486 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Local endpoint object management
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/udp.h>
+#include <net/udp_tunnel.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static void rxrpc_local_rcu(struct rcu_head *);
+
+/*
+ * Handle an ICMP/ICMP6 error turning up at the tunnel.  Push it through the
+ * usual mechanism so that it gets parsed and presented through the UDP
+ * socket's error_report().
+ */
+static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err,
+				__be16 port, u32 info, u8 *payload)
+{
+	if (ip_hdr(skb)->version == IPVERSION)
+		return ip_icmp_error(sk, skb, err, port, info, payload);
+	if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6))
+		return ipv6_icmp_error(sk, skb, err, port, info, payload);
+}
+
+/*
+ * Set or clear the Don't Fragment flag on a socket.
+ */
+void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set)
+{
+	if (set)
+		ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
+	else
+		ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DONT);
+}
+
+/*
+ * Compare a local to an address.  Return -ve, 0 or +ve to indicate less than,
+ * same or greater than.
+ *
+ * We explicitly don't compare the RxRPC service ID as we want to reject
+ * conflicting uses by differing services.  Further, we don't want to share
+ * addresses with different options (IPv6), so we don't compare those bits
+ * either.
+ */
+static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
+				const struct sockaddr_rxrpc *srx)
+{
+	long diff;
+
+	diff = ((local->srx.transport_type - srx->transport_type) ?:
+		(local->srx.transport_len - srx->transport_len) ?:
+		(local->srx.transport.family - srx->transport.family));
+	if (diff != 0)
+		return diff;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		/* If the choice of UDP port is left up to the transport, then
+		 * the endpoint record doesn't match.
+		 */
+		return ((u16 __force)local->srx.transport.sin.sin_port -
+			(u16 __force)srx->transport.sin.sin_port) ?:
+			memcmp(&local->srx.transport.sin.sin_addr,
+			       &srx->transport.sin.sin_addr,
+			       sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		/* If the choice of UDP6 port is left up to the transport, then
+		 * the endpoint record doesn't match.
+		 */
+		return ((u16 __force)local->srx.transport.sin6.sin6_port -
+			(u16 __force)srx->transport.sin6.sin6_port) ?:
+			memcmp(&local->srx.transport.sin6.sin6_addr,
+			       &srx->transport.sin6.sin6_addr,
+			       sizeof(struct in6_addr));
+#endif
+	default:
+		BUG();
+	}
+}
+
+static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
+{
+	struct rxrpc_local *local =
+		container_of(timer, struct rxrpc_local, client_conn_reap_timer);
+
+	if (!local->kill_all_client_conns &&
+	    test_and_set_bit(RXRPC_CLIENT_CONN_REAP_TIMER, &local->client_conn_flags))
+		rxrpc_wake_up_io_thread(local);
+}
+
+/*
+ * Allocate a new local endpoint.
+ */
+static struct rxrpc_local *rxrpc_alloc_local(struct net *net,
+					     const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_local *local;
+	u32 tmp;
+
+	local = kzalloc_obj(struct rxrpc_local);
+	if (local) {
+		refcount_set(&local->ref, 1);
+		atomic_set(&local->active_users, 1);
+		local->net = net;
+		local->rxnet = rxrpc_net(net);
+		INIT_HLIST_NODE(&local->link);
+		init_completion(&local->io_thread_ready);
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+		skb_queue_head_init(&local->rx_delay_queue);
+#endif
+		skb_queue_head_init(&local->rx_queue);
+		INIT_LIST_HEAD(&local->conn_attend_q);
+		INIT_LIST_HEAD(&local->call_attend_q);
+
+		local->client_bundles = RB_ROOT;
+		spin_lock_init(&local->client_bundles_lock);
+		local->kill_all_client_conns = false;
+		INIT_LIST_HEAD(&local->idle_client_conns);
+		timer_setup(&local->client_conn_reap_timer,
+			    rxrpc_client_conn_reap_timeout, 0);
+
+		spin_lock_init(&local->lock);
+		rwlock_init(&local->services_lock);
+		local->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		memcpy(&local->srx, srx, sizeof(*srx));
+		local->srx.srx_service = 0;
+		idr_init(&local->conn_ids);
+		get_random_bytes(&tmp, sizeof(tmp));
+		tmp &= 0x3fffffff;
+		if (tmp == 0)
+			tmp = 1;
+		idr_set_cursor(&local->conn_ids, tmp);
+		INIT_LIST_HEAD(&local->new_client_calls);
+		spin_lock_init(&local->client_call_lock);
+
+		trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1);
+	}
+
+	_leave(" = %p", local);
+	return local;
+}
+
+/*
+ * create the local socket
+ * - must be called with rxrpc_local_mutex locked
+ */
+static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
+{
+	struct udp_tunnel_sock_cfg tuncfg = {NULL};
+	struct sockaddr_rxrpc *srx = &local->srx;
+	struct udp_port_cfg udp_conf = {0};
+	struct task_struct *io_thread;
+	struct sock *usk;
+	int ret;
+
+	_enter("%p{%d,%d}",
+	       local, srx->transport_type, srx->transport.family);
+
+	udp_conf.family = srx->transport.family;
+	udp_conf.use_udp_checksums = true;
+	if (udp_conf.family == AF_INET) {
+		udp_conf.local_ip = srx->transport.sin.sin_addr;
+		udp_conf.local_udp_port = srx->transport.sin.sin_port;
+#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
+	} else {
+		udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
+		udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
+		udp_conf.use_udp6_tx_checksums = true;
+		udp_conf.use_udp6_rx_checksums = true;
+#endif
+	}
+	ret = udp_sock_create(net, &udp_conf, &local->socket);
+	if (ret < 0) {
+		_leave(" = %d [socket]", ret);
+		return ret;
+	}
+
+	tuncfg.encap_type = UDP_ENCAP_RXRPC;
+	tuncfg.encap_rcv = rxrpc_encap_rcv;
+	tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
+	tuncfg.sk_user_data = local;
+	setup_udp_tunnel_sock(net, local->socket->sk, &tuncfg);
+
+	/* set the socket up */
+	usk = local->socket->sk;
+	usk->sk_error_report = rxrpc_error_report;
+
+	switch (srx->transport.family) {
+	case AF_INET6:
+		/* we want to receive ICMPv6 errors */
+		ip6_sock_set_recverr(usk);
+
+		/* Fall through and set IPv4 options too otherwise we don't get
+		 * errors from IPv4 packets sent through the IPv6 socket.
+		 */
+		fallthrough;
+	case AF_INET:
+		/* we want to receive ICMP errors */
+		ip_sock_set_recverr(usk);
+
+		/* we want to set the don't fragment bit */
+		rxrpc_local_dont_fragment(local, true);
+		break;
+
+	default:
+		BUG();
+	}
+
+	io_thread = kthread_run(rxrpc_io_thread, local,
+				"krxrpcio/%u", ntohs(udp_conf.local_udp_port));
+	if (IS_ERR(io_thread)) {
+		ret = PTR_ERR(io_thread);
+		goto error_sock;
+	}
+
+	wait_for_completion(&local->io_thread_ready);
+	WRITE_ONCE(local->io_thread, io_thread);
+	_leave(" = 0");
+	return 0;
+
+error_sock:
+	kernel_sock_shutdown(local->socket, SHUT_RDWR);
+	local->socket->sk->sk_user_data = NULL;
+	sock_release(local->socket);
+	local->socket = NULL;
+	return ret;
+}
+
+/*
+ * Look up or create a new local endpoint using the specified local address.
+ */
+struct rxrpc_local *rxrpc_lookup_local(struct net *net,
+				       const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+	struct hlist_node *cursor;
+	long diff;
+	int ret;
+
+	_enter("{%d,%d,%pISp}",
+	       srx->transport_type, srx->transport.family, &srx->transport);
+
+	mutex_lock(&rxnet->local_mutex);
+
+	hlist_for_each(cursor, &rxnet->local_endpoints) {
+		local = hlist_entry(cursor, struct rxrpc_local, link);
+
+		diff = rxrpc_local_cmp_key(local, srx);
+		if (diff != 0)
+			continue;
+
+		/* Services aren't allowed to share transport sockets, so
+		 * reject that here.  It is possible that the object is dying -
+		 * but it may also still have the local transport address that
+		 * we want bound.
+		 */
+		if (srx->srx_service) {
+			local = NULL;
+			goto addr_in_use;
+		}
+
+		/* Found a match.  We want to replace a dying object.
+		 * Attempting to bind the transport socket may still fail if
+		 * we're attempting to use a local address that the dying
+		 * object is still using.
+		 */
+		if (!rxrpc_use_local(local, rxrpc_local_use_lookup))
+			break;
+
+		goto found;
+	}
+
+	local = rxrpc_alloc_local(net, srx);
+	if (!local)
+		goto nomem;
+
+	ret = rxrpc_open_socket(local, net);
+	if (ret < 0)
+		goto sock_error;
+
+	if (cursor) {
+		hlist_replace_rcu(cursor, &local->link);
+		cursor->pprev = NULL;
+	} else {
+		hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
+	}
+
+found:
+	mutex_unlock(&rxnet->local_mutex);
+	_leave(" = %p", local);
+	return local;
+
+nomem:
+	ret = -ENOMEM;
+sock_error:
+	mutex_unlock(&rxnet->local_mutex);
+	if (local)
+		call_rcu(&local->rcu, rxrpc_local_rcu);
+	_leave(" = %d", ret);
+	return ERR_PTR(ret);
+
+addr_in_use:
+	mutex_unlock(&rxnet->local_mutex);
+	_leave(" = -EADDRINUSE");
+	return ERR_PTR(-EADDRINUSE);
+}
+
+/*
+ * Get a ref on a local endpoint.
+ */
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local,
+				    enum rxrpc_local_trace why)
+{
+	int r, u;
+
+	u = atomic_read(&local->active_users);
+	__refcount_inc(&local->ref, &r);
+	trace_rxrpc_local(local->debug_id, why, r + 1, u);
+	return local;
+}
+
+/*
+ * Get a ref on a local endpoint unless its usage has already reached 0.
+ */
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local,
+					  enum rxrpc_local_trace why)
+{
+	int r, u;
+
+	if (local && __refcount_inc_not_zero(&local->ref, &r)) {
+		u = atomic_read(&local->active_users);
+		trace_rxrpc_local(local->debug_id, why, r + 1, u);
+		return local;
+	}
+
+	return NULL;
+}
+
+/*
+ * Drop a ref on a local endpoint.
+ */
+void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
+{
+	unsigned int debug_id;
+	bool dead;
+	int r, u;
+
+	if (local) {
+		debug_id = local->debug_id;
+
+		u = atomic_read(&local->active_users);
+		dead = __refcount_dec_and_test(&local->ref, &r);
+		trace_rxrpc_local(debug_id, why, r, u);
+
+		if (dead)
+			call_rcu(&local->rcu, rxrpc_local_rcu);
+	}
+}
+
+/*
+ * Start using a local endpoint.
+ */
+struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local,
+				    enum rxrpc_local_trace why)
+{
+	local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use);
+	if (!local)
+		return NULL;
+
+	if (!__rxrpc_use_local(local, why)) {
+		rxrpc_put_local(local, rxrpc_local_put_for_use);
+		return NULL;
+	}
+
+	return local;
+}
+
+/*
+ * Cease using a local endpoint.  Once the number of active users reaches 0, we
+ * start the closure of the transport in the I/O thread..
+ */
+void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
+{
+	unsigned int debug_id;
+	int r, u;
+
+	if (local) {
+		debug_id = local->debug_id;
+		r = refcount_read(&local->ref);
+		u = atomic_dec_return(&local->active_users);
+		trace_rxrpc_local(debug_id, why, r, u);
+		if (u == 0)
+			kthread_stop(local->io_thread);
+	}
+}
+
+/*
+ * Destroy a local endpoint's socket and then hand the record to RCU to dispose
+ * of.
+ *
+ * Closing the socket cannot be done from bottom half context or RCU callback
+ * context because it might sleep.
+ */
+void rxrpc_destroy_local(struct rxrpc_local *local)
+{
+	struct socket *socket = local->socket;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	_enter("%d", local->debug_id);
+
+	local->dead = true;
+
+	mutex_lock(&rxnet->local_mutex);
+	hlist_del_init_rcu(&local->link);
+	mutex_unlock(&rxnet->local_mutex);
+
+	rxrpc_clean_up_local_conns(local);
+	rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
+	ASSERT(!local->service);
+
+	if (socket) {
+		local->socket = NULL;
+		kernel_sock_shutdown(socket, SHUT_RDWR);
+		socket->sk->sk_user_data = NULL;
+		sock_release(socket);
+	}
+
+	/* At this point, there should be no more packets coming in to the
+	 * local endpoint.
+	 */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	rxrpc_purge_queue(&local->rx_delay_queue);
+#endif
+	rxrpc_purge_queue(&local->rx_queue);
+	rxrpc_purge_client_connections(local);
+	page_frag_cache_drain(&local->tx_alloc);
+}
+
+/*
+ * Destroy a local endpoint after the RCU grace period expires.
+ */
+static void rxrpc_local_rcu(struct rcu_head *rcu)
+{
+	struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
+
+	rxrpc_see_local(local, rxrpc_local_free);
+	kfree(local);
+}
+
+/*
+ * Verify the local endpoint list is empty by this point.
+ */
+void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_local *local;
+
+	_enter("");
+
+	flush_workqueue(rxrpc_workqueue);
+
+	if (!hlist_empty(&rxnet->local_endpoints)) {
+		mutex_lock(&rxnet->local_mutex);
+		hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
+			pr_err("AF_RXRPC: Leaked local %p {%d}\n",
+			       local, refcount_read(&local->ref));
+		}
+		mutex_unlock(&rxnet->local_mutex);
+		BUG();
+	}
+}
diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c
new file mode 100644
index 000000000..8fcc8139d
--- /dev/null
+++ b/net/rxrpc/misc.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Miscellaneous bits
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * The maximum listening backlog queue size that may be set on a socket by
+ * listen().
+ */
+unsigned int rxrpc_max_backlog __read_mostly = 10;
+
+/*
+ * How long to wait before scheduling an ACK with subtype DELAY (in ms).
+ *
+ * We use this when we've received new data packets.  If those packets aren't
+ * all consumed within this time we will send a DELAY ACK if an ACK was not
+ * requested to let the sender know it doesn't need to resend.
+ */
+unsigned long rxrpc_soft_ack_delay = 1000;
+
+/*
+ * How long to wait before scheduling an ACK with subtype IDLE (in ms).
+ *
+ * We use this when we've consumed some previously soft-ACK'd packets when
+ * further packets aren't immediately received to decide when to send an IDLE
+ * ACK let the other end know that it can free up its Tx buffer space.
+ */
+unsigned long rxrpc_idle_ack_delay = 500;
+
+/*
+ * Receive window size in packets.  This indicates the maximum number of
+ * unconsumed received packets we're willing to retain in memory.  Once this
+ * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
+ * packets.
+ */
+unsigned int rxrpc_rx_window_size = 255;
+
+/*
+ * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
+ * made by gluing normal packets together that we're willing to handle.
+ */
+unsigned int rxrpc_rx_mtu = RXRPC_JUMBO(46);
+
+/*
+ * The maximum number of fragments in a received jumbo packet that we tell the
+ * sender that we're willing to handle.
+ */
+unsigned int rxrpc_rx_jumbo_max = 46;
+
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+/*
+ * The delay to inject into packet reception.
+ */
+unsigned long rxrpc_inject_rx_delay;
+#endif
diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
new file mode 100644
index 000000000..9a9834145
--- /dev/null
+++ b/net/rxrpc/net_ns.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* rxrpc network namespace handling.
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/proc_fs.h>
+#include "ar-internal.h"
+
+unsigned int rxrpc_net_id;
+
+static void rxrpc_service_conn_reap_timeout(struct timer_list *timer)
+{
+	struct rxrpc_net *rxnet =
+		container_of(timer, struct rxrpc_net, service_conn_reap_timer);
+
+	if (rxnet->live)
+		rxrpc_queue_work(&rxnet->service_conn_reaper);
+}
+
+static void rxrpc_peer_keepalive_timeout(struct timer_list *timer)
+{
+	struct rxrpc_net *rxnet =
+		container_of(timer, struct rxrpc_net, peer_keepalive_timer);
+
+	if (rxnet->live)
+		rxrpc_queue_work(&rxnet->peer_keepalive_work);
+}
+
+/*
+ * Initialise a per-network namespace record.
+ */
+static __net_init int rxrpc_init_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+	int ret, i;
+
+	rxnet->live = true;
+	get_random_bytes(&rxnet->epoch, sizeof(rxnet->epoch));
+	rxnet->epoch |= RXRPC_RANDOM_EPOCH;
+
+	INIT_LIST_HEAD(&rxnet->calls);
+	spin_lock_init(&rxnet->call_lock);
+	atomic_set(&rxnet->nr_calls, 1);
+
+	atomic_set(&rxnet->nr_conns, 1);
+	INIT_LIST_HEAD(&rxnet->bundle_proc_list);
+	INIT_LIST_HEAD(&rxnet->conn_proc_list);
+	INIT_LIST_HEAD(&rxnet->service_conns);
+	rwlock_init(&rxnet->conn_lock);
+	INIT_WORK(&rxnet->service_conn_reaper,
+		  rxrpc_service_connection_reaper);
+	timer_setup(&rxnet->service_conn_reap_timer,
+		    rxrpc_service_conn_reap_timeout, 0);
+
+	atomic_set(&rxnet->nr_client_conns, 0);
+
+	INIT_HLIST_HEAD(&rxnet->local_endpoints);
+	mutex_init(&rxnet->local_mutex);
+
+	hash_init(rxnet->peer_hash);
+	spin_lock_init(&rxnet->peer_hash_lock);
+	for (i = 0; i < ARRAY_SIZE(rxnet->peer_keepalive); i++)
+		INIT_LIST_HEAD(&rxnet->peer_keepalive[i]);
+	INIT_LIST_HEAD(&rxnet->peer_keepalive_new);
+	timer_setup(&rxnet->peer_keepalive_timer,
+		    rxrpc_peer_keepalive_timeout, 0);
+	INIT_WORK(&rxnet->peer_keepalive_work, rxrpc_peer_keepalive_worker);
+	rxnet->peer_keepalive_base = ktime_get_seconds();
+
+	ret = -ENOMEM;
+	rxnet->proc_net = proc_net_mkdir(net, "rxrpc", net->proc_net);
+	if (!rxnet->proc_net)
+		goto err_proc;
+
+	proc_create_net("calls", 0444, rxnet->proc_net, &rxrpc_call_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("conns", 0444, rxnet->proc_net,
+			&rxrpc_connection_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("bundles", 0444, rxnet->proc_net,
+			&rxrpc_bundle_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("peers", 0444, rxnet->proc_net,
+			&rxrpc_peer_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net("locals", 0444, rxnet->proc_net,
+			&rxrpc_local_seq_ops,
+			sizeof(struct seq_net_private));
+	proc_create_net_single_write("stats", S_IFREG | 0644, rxnet->proc_net,
+				     rxrpc_stats_show, rxrpc_stats_clear, NULL);
+	return 0;
+
+err_proc:
+	rxnet->live = false;
+	return ret;
+}
+
+/*
+ * Clean up a per-network namespace record.
+ */
+static __net_exit void rxrpc_exit_net(struct net *net)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(net);
+
+	rxnet->live = false;
+	timer_delete_sync(&rxnet->peer_keepalive_timer);
+	cancel_work_sync(&rxnet->peer_keepalive_work);
+	/* Remove the timer again as the worker may have restarted it. */
+	timer_delete_sync(&rxnet->peer_keepalive_timer);
+	rxrpc_destroy_all_calls(rxnet);
+	rxrpc_destroy_all_connections(rxnet);
+	rxrpc_destroy_all_peers(rxnet);
+	rxrpc_destroy_all_locals(rxnet);
+	proc_remove(rxnet->proc_net);
+}
+
+struct pernet_operations rxrpc_net_ops = {
+	.init	= rxrpc_init_net,
+	.exit	= rxrpc_exit_net,
+	.id	= &rxrpc_net_id,
+	.size	= sizeof(struct rxrpc_net),
+};
diff --git a/net/rxrpc/oob.c b/net/rxrpc/oob.c
new file mode 100644
index 000000000..c80ee2487
--- /dev/null
+++ b/net/rxrpc/oob.c
@@ -0,0 +1,387 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Out of band message handling (e.g. challenge-response)
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/sched/signal.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+enum rxrpc_oob_command {
+	RXRPC_OOB_CMD_UNSET,
+	RXRPC_OOB_CMD_RESPOND,
+} __mode(byte);
+
+struct rxrpc_oob_params {
+	u64			oob_id;		/* ID number of message if reply */
+	s32			abort_code;
+	enum rxrpc_oob_command	command;
+	bool			have_oob_id:1;
+};
+
+/*
+ * Post an out-of-band message for attention by the socket or kernel service
+ * associated with a reference call.
+ */
+bool rxrpc_notify_socket_oob(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+	bool queued = false;
+
+	rcu_read_lock();
+
+	rx = rcu_dereference(call->socket);
+	if (rx) {
+		sk = &rx->sk;
+		spin_lock_irq(&rx->recvmsg_lock);
+
+		if (sk->sk_state < RXRPC_CLOSE) {
+			skb->skb_mstamp_ns = rx->oob_id_counter++;
+			rxrpc_get_skb(skb, rxrpc_skb_get_post_oob);
+			skb_queue_tail(&rx->recvmsg_oobq, skb);
+			queued = true;
+
+			trace_rxrpc_notify_socket(call->debug_id, sp->hdr.serial);
+			if (rx->app_ops)
+				rx->app_ops->notify_oob(sk, skb);
+		}
+
+		spin_unlock_irq(&rx->recvmsg_lock);
+		if (queued && !rx->app_ops && !sock_flag(sk, SOCK_DEAD))
+			sk->sk_data_ready(sk);
+	}
+
+	rcu_read_unlock();
+	return queued;
+}
+
+/*
+ * Locate the OOB message to respond to by its ID.
+ */
+static struct sk_buff *rxrpc_find_pending_oob(struct rxrpc_sock *rx, u64 oob_id)
+{
+	struct rb_node *p;
+	struct sk_buff *skb;
+
+	p = rx->pending_oobq.rb_node;
+	while (p) {
+		skb = rb_entry(p, struct sk_buff, rbnode);
+
+		if (oob_id < skb->skb_mstamp_ns)
+			p = p->rb_left;
+		else if (oob_id > skb->skb_mstamp_ns)
+			p = p->rb_right;
+		else
+			return skb;
+	}
+
+	return NULL;
+}
+
+/*
+ * Add an OOB message into the pending-response set.  We always assign the next
+ * value from a 64-bit counter to the oob_id, so just assume we're always going
+ * to be on the right-hand edge of the tree and that the counter won't wrap.
+ * The tree is also given a ref to the message.
+ */
+void rxrpc_add_pending_oob(struct rxrpc_sock *rx, struct sk_buff *skb)
+{
+	struct rb_node **pp = &rx->pending_oobq.rb_node, *p = NULL;
+
+	while (*pp) {
+		p = *pp;
+		pp = &(*pp)->rb_right;
+	}
+
+	rb_link_node(&skb->rbnode, p, pp);
+	rb_insert_color(&skb->rbnode, &rx->pending_oobq);
+}
+
+/*
+ * Extract control messages from the sendmsg() control buffer.
+ */
+static int rxrpc_sendmsg_oob_cmsg(struct msghdr *msg, struct rxrpc_oob_params *p)
+{
+	struct cmsghdr *cmsg;
+	int len;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
+		_debug("CMSG %d, %d, %d",
+		       cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+		if (cmsg->cmsg_level != SOL_RXRPC)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case RXRPC_OOB_ID:
+			if (len != sizeof(p->oob_id) || p->have_oob_id)
+				return -EINVAL;
+			memcpy(&p->oob_id, CMSG_DATA(cmsg), sizeof(p->oob_id));
+			p->have_oob_id = true;
+			break;
+		case RXRPC_RESPOND:
+			if (p->command != RXRPC_OOB_CMD_UNSET)
+				return -EINVAL;
+			p->command = RXRPC_OOB_CMD_RESPOND;
+			break;
+		case RXRPC_ABORT:
+			if (len != sizeof(p->abort_code) || p->abort_code)
+				return -EINVAL;
+			memcpy(&p->abort_code, CMSG_DATA(cmsg), sizeof(p->abort_code));
+			if (p->abort_code == 0)
+				return -EINVAL;
+			break;
+		case RXRPC_RESP_RXGK_APPDATA:
+			if (p->command != RXRPC_OOB_CMD_RESPOND)
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	switch (p->command) {
+	case RXRPC_OOB_CMD_RESPOND:
+		if (!p->have_oob_id)
+			return -EBADSLT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Allow userspace to respond to an OOB using sendmsg().
+ */
+static int rxrpc_respond_to_oob(struct rxrpc_sock *rx,
+				struct rxrpc_oob_params *p,
+				struct msghdr *msg)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	int ret;
+
+	skb = rxrpc_find_pending_oob(rx, p->oob_id);
+	if (skb)
+		rb_erase(&skb->rbnode, &rx->pending_oobq);
+	release_sock(&rx->sk);
+	if (!skb)
+		return -EBADSLT;
+
+	sp = rxrpc_skb(skb);
+
+	switch (p->command) {
+	case RXRPC_OOB_CMD_RESPOND:
+		ret = -EPROTO;
+		if (skb->mark != RXRPC_OOB_CHALLENGE)
+			break;
+		conn = sp->chall.conn;
+		ret = -EOPNOTSUPP;
+		if (!conn->security->sendmsg_respond_to_challenge)
+			break;
+		if (p->abort_code) {
+			rxrpc_abort_conn(conn, NULL, p->abort_code, -ECONNABORTED,
+					 rxrpc_abort_response_sendmsg);
+			ret = 0;
+		} else {
+			ret = conn->security->sendmsg_respond_to_challenge(skb, msg);
+		}
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	switch (skb->mark) {
+	case RXRPC_OOB_CHALLENGE:
+		rxrpc_put_connection(sp->chall.conn, rxrpc_conn_put_oob);
+		break;
+	}
+	rxrpc_free_skb(skb, rxrpc_skb_put_oob);
+	return ret;
+}
+
+/*
+ * Send an out-of-band message or respond to a received out-of-band message.
+ * - caller gives us the socket lock
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_sendmsg_oob(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+{
+	struct rxrpc_oob_params p = {};
+	int ret;
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_oob_cmsg(msg, &p);
+	if (ret < 0)
+		goto error_release_sock;
+
+	if (p.have_oob_id)
+		return rxrpc_respond_to_oob(rx, &p, msg);
+
+	release_sock(&rx->sk);
+
+	switch (p.command) {
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	_leave(" = %d", ret);
+	return ret;
+
+error_release_sock:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_query_oob - Query the parameters of an out-of-band message
+ * @oob: The message to query
+ * @_peer: Where to return the peer record
+ * @_peer_appdata: The application data attached to a peer record
+ *
+ * Extract useful parameters from an out-of-band message.  The source peer
+ * parameters are returned through the argument list and the message type is
+ * returned.
+ *
+ * Return:
+ * * %RXRPC_OOB_CHALLENGE - Challenge wanting a response.
+ */
+enum rxrpc_oob_type rxrpc_kernel_query_oob(struct sk_buff *oob,
+					   struct rxrpc_peer **_peer,
+					   unsigned long *_peer_appdata)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(oob);
+	enum rxrpc_oob_type type = oob->mark;
+
+	switch (type) {
+	case RXRPC_OOB_CHALLENGE:
+		*_peer		= sp->chall.conn->peer;
+		*_peer_appdata	= sp->chall.conn->peer->app_data;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		*_peer		= NULL;
+		*_peer_appdata	= 0;
+		break;
+	}
+
+	return type;
+}
+EXPORT_SYMBOL(rxrpc_kernel_query_oob);
+
+/**
+ * rxrpc_kernel_dequeue_oob - Dequeue and return the front OOB message
+ * @sock: The socket to query
+ * @_type: Where to return the message type
+ *
+ * Dequeue the front OOB message, if there is one, and return it and
+ * its type.
+ *
+ * Return: The sk_buff representing the OOB message or %NULL if the queue was
+ * empty.
+ */
+struct sk_buff *rxrpc_kernel_dequeue_oob(struct socket *sock,
+					 enum rxrpc_oob_type *_type)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct sk_buff *oob;
+
+	oob = skb_dequeue(&rx->recvmsg_oobq);
+	if (oob)
+		*_type = oob->mark;
+	return oob;
+}
+EXPORT_SYMBOL(rxrpc_kernel_dequeue_oob);
+
+/**
+ * rxrpc_kernel_free_oob - Free an out-of-band message
+ * @oob: The OOB message to free
+ *
+ * Free an OOB message along with any resources it holds.
+ */
+void rxrpc_kernel_free_oob(struct sk_buff *oob)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(oob);
+
+	switch (oob->mark) {
+	case RXRPC_OOB_CHALLENGE:
+		rxrpc_put_connection(sp->chall.conn, rxrpc_conn_put_oob);
+		break;
+	}
+
+	rxrpc_free_skb(oob, rxrpc_skb_put_purge_oob);
+}
+EXPORT_SYMBOL(rxrpc_kernel_free_oob);
+
+/**
+ * rxrpc_kernel_query_challenge - Query the parameters of a challenge
+ * @challenge: The challenge to query
+ * @_peer: Where to return the peer record
+ * @_peer_appdata: The application data attached to a peer record
+ * @_service_id: Where to return the connection service ID
+ * @_security_index: Where to return the connection security index
+ *
+ * Extract useful parameters from a CHALLENGE message.
+ */
+void rxrpc_kernel_query_challenge(struct sk_buff *challenge,
+				  struct rxrpc_peer **_peer,
+				  unsigned long *_peer_appdata,
+				  u16 *_service_id, u8 *_security_index)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(challenge);
+
+	*_peer		= sp->chall.conn->peer;
+	*_peer_appdata	= sp->chall.conn->peer->app_data;
+	*_service_id	= sp->hdr.serviceId;
+	*_security_index = sp->hdr.securityIndex;
+}
+EXPORT_SYMBOL(rxrpc_kernel_query_challenge);
+
+/**
+ * rxrpc_kernel_reject_challenge - Allow a kernel service to reject a challenge
+ * @challenge: The challenge to be rejected
+ * @abort_code: The abort code to stick into the ABORT packet
+ * @error: Local error value
+ * @why: Indication as to why.
+ *
+ * Allow a kernel service to reject a challenge by aborting the connection if
+ * it's still in an abortable state.  The error is returned so this function
+ * can be used with a return statement.
+ *
+ * Return: The %error parameter.
+ */
+int rxrpc_kernel_reject_challenge(struct sk_buff *challenge, u32 abort_code,
+				  int error, enum rxrpc_abort_reason why)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(challenge);
+
+	_enter("{%x},%d,%d,%u", sp->hdr.serial, abort_code, error, why);
+
+	rxrpc_abort_conn(sp->chall.conn, NULL, abort_code, error, why);
+	return error;
+}
+EXPORT_SYMBOL(rxrpc_kernel_reject_challenge);
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
new file mode 100644
index 000000000..88cad087f
--- /dev/null
+++ b/net/rxrpc/output.c
@@ -0,0 +1,983 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC packet transmission
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/udp.h>
+#include "ar-internal.h"
+
+ssize_t do_udp_sendmsg(struct socket *socket, struct msghdr *msg, size_t len)
+{
+	struct sockaddr *sa = msg->msg_name;
+	struct sock *sk = socket->sk;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6)) {
+		if (sa->sa_family == AF_INET6) {
+			if (sk->sk_family != AF_INET6) {
+				pr_warn("AF_INET6 address on AF_INET socket\n");
+				return -ENOPROTOOPT;
+			}
+			return udpv6_sendmsg(sk, msg, len);
+		}
+	}
+	return udp_sendmsg(sk, msg, len);
+}
+
+struct rxrpc_abort_buffer {
+	struct rxrpc_wire_header whdr;
+	__be32 abort_code;
+};
+
+static const char rxrpc_keepalive_string[] = "";
+
+/*
+ * Increase Tx backoff on transmission failure and clear it on success.
+ */
+static void rxrpc_tx_backoff(struct rxrpc_call *call, int ret)
+{
+	if (ret < 0) {
+		if (call->tx_backoff < 1000)
+			call->tx_backoff += 100;
+	} else {
+		call->tx_backoff = 0;
+	}
+}
+
+/*
+ * Arrange for a keepalive ping a certain time after we last transmitted.  This
+ * lets the far side know we're still interested in this call and helps keep
+ * the route through any intervening firewall open.
+ *
+ * Receiving a response to the ping will prevent the ->expect_rx_by timer from
+ * expiring.
+ */
+static void rxrpc_set_keepalive(struct rxrpc_call *call, ktime_t now)
+{
+	ktime_t delay = ms_to_ktime(READ_ONCE(call->next_rx_timo) / 6);
+
+	call->keepalive_at = ktime_add(ktime_get_real(), delay);
+	trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_keepalive);
+}
+
+/*
+ * Allocate transmission buffers for an ACK and attach them to local->kv[].
+ */
+static int rxrpc_alloc_ack(struct rxrpc_call *call, size_t sack_size)
+{
+	struct rxrpc_wire_header *whdr;
+	struct rxrpc_acktrailer *trailer;
+	struct rxrpc_ackpacket *ack;
+	struct kvec *kv = call->local->kvec;
+	gfp_t gfp = rcu_read_lock_held() ? GFP_ATOMIC | __GFP_NOWARN : GFP_NOFS;
+	void *buf, *buf2 = NULL;
+	u8 *filler;
+
+	buf = page_frag_alloc(&call->local->tx_alloc,
+			      sizeof(*whdr) + sizeof(*ack) + 1 + 3 + sizeof(*trailer), gfp);
+	if (!buf)
+		return -ENOMEM;
+
+	if (sack_size) {
+		buf2 = page_frag_alloc(&call->local->tx_alloc, sack_size, gfp);
+		if (!buf2) {
+			page_frag_free(buf);
+			return -ENOMEM;
+		}
+	}
+
+	whdr	= buf;
+	ack	= buf + sizeof(*whdr);
+	filler	= buf + sizeof(*whdr) + sizeof(*ack) + 1;
+	trailer	= buf + sizeof(*whdr) + sizeof(*ack) + 1 + 3;
+
+	kv[0].iov_base	= whdr;
+	kv[0].iov_len	= sizeof(*whdr) + sizeof(*ack);
+	kv[1].iov_base	= buf2;
+	kv[1].iov_len	= sack_size;
+	kv[2].iov_base	= filler;
+	kv[2].iov_len	= 3 + sizeof(*trailer);
+	return 3; /* Number of kvec[] used. */
+}
+
+static void rxrpc_free_ack(struct rxrpc_call *call)
+{
+	page_frag_free(call->local->kvec[0].iov_base);
+	if (call->local->kvec[1].iov_base)
+		page_frag_free(call->local->kvec[1].iov_base);
+}
+
+/*
+ * Record the beginning of an RTT probe.
+ */
+static void rxrpc_begin_rtt_probe(struct rxrpc_call *call, rxrpc_serial_t serial,
+				  ktime_t now, enum rxrpc_rtt_tx_trace why)
+{
+	unsigned long avail = call->rtt_avail;
+	int rtt_slot = 9;
+
+	if (!(avail & RXRPC_CALL_RTT_AVAIL_MASK))
+		goto no_slot;
+
+	rtt_slot = __ffs(avail & RXRPC_CALL_RTT_AVAIL_MASK);
+	if (!test_and_clear_bit(rtt_slot, &call->rtt_avail))
+		goto no_slot;
+
+	call->rtt_serial[rtt_slot] = serial;
+	call->rtt_sent_at[rtt_slot] = now;
+	smp_wmb(); /* Write data before avail bit */
+	set_bit(rtt_slot + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
+
+	trace_rxrpc_rtt_tx(call, why, rtt_slot, serial);
+	return;
+
+no_slot:
+	trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_no_slot, rtt_slot, serial);
+}
+
+/*
+ * Fill out an ACK packet.
+ */
+static int rxrpc_fill_out_ack(struct rxrpc_call *call, int nr_kv, u8 ack_reason,
+			      rxrpc_serial_t serial_to_ack, rxrpc_serial_t *_ack_serial)
+{
+	struct kvec *kv = call->local->kvec;
+	struct rxrpc_wire_header *whdr = kv[0].iov_base;
+	struct rxrpc_acktrailer *trailer = kv[2].iov_base + 3;
+	struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);
+	unsigned int qsize, sack, wrap, to, max_mtu, if_mtu;
+	rxrpc_seq_t window, wtop;
+	ktime_t now = ktime_get_real();
+	int rsize;
+	u8 *filler = kv[2].iov_base;
+	u8 *sackp = kv[1].iov_base;
+
+	rxrpc_inc_stat(call->rxnet, stat_tx_ack_fill);
+
+	window = call->ackr_window;
+	wtop   = call->ackr_wtop;
+	sack   = call->ackr_sack_base % RXRPC_SACK_SIZE;
+
+	*_ack_serial = rxrpc_get_next_serial(call->conn);
+
+	whdr->epoch		= htonl(call->conn->proto.epoch);
+	whdr->cid		= htonl(call->cid);
+	whdr->callNumber	= htonl(call->call_id);
+	whdr->serial		= htonl(*_ack_serial);
+	whdr->seq		= 0;
+	whdr->type		= RXRPC_PACKET_TYPE_ACK;
+	whdr->flags		= call->conn->out_clientflag | RXRPC_SLOW_START_OK;
+	whdr->userStatus	= 0;
+	whdr->securityIndex	= call->security_ix;
+	whdr->_rsvd		= 0;
+	whdr->serviceId		= htons(call->dest_srx.srx_service);
+
+	ack->bufferSpace	= 0;
+	ack->maxSkew		= 0;
+	ack->firstPacket	= htonl(window);
+	ack->previousPacket	= htonl(call->rx_highest_seq);
+	ack->serial		= htonl(serial_to_ack);
+	ack->reason		= ack_reason;
+	ack->nAcks		= wtop - window;
+	filler[0]		= 0;
+	filler[1]		= 0;
+	filler[2]		= 0;
+
+	if (ack_reason == RXRPC_ACK_PING)
+		whdr->flags |= RXRPC_REQUEST_ACK;
+
+	if (after(wtop, window)) {
+		kv[1].iov_len = ack->nAcks;
+
+		wrap = RXRPC_SACK_SIZE - sack;
+		to = umin(ack->nAcks, RXRPC_SACK_SIZE);
+
+		if (sack + ack->nAcks <= RXRPC_SACK_SIZE) {
+			memcpy(sackp, call->ackr_sack_table + sack, ack->nAcks);
+		} else {
+			memcpy(sackp, call->ackr_sack_table + sack, wrap);
+			memcpy(sackp + wrap, call->ackr_sack_table, to - wrap);
+		}
+	} else if (before(wtop, window)) {
+		pr_warn("ack window backward %x %x", window, wtop);
+	} else if (ack->reason == RXRPC_ACK_DELAY) {
+		ack->reason = RXRPC_ACK_IDLE;
+	}
+
+	qsize = (window - 1) - call->rx_consumed;
+	rsize = max_t(int, call->rx_winsize - qsize, 0);
+
+	if_mtu = call->peer->if_mtu - call->peer->hdrsize;
+	if (call->peer->ackr_adv_pmtud) {
+		max_mtu = umax(call->peer->max_data, rxrpc_rx_mtu);
+	} else {
+		if_mtu = umin(if_mtu, 1444);
+		max_mtu = if_mtu;
+	}
+
+	trailer->maxMTU		= htonl(max_mtu);
+	trailer->ifMTU		= htonl(if_mtu);
+	trailer->rwind		= htonl(rsize);
+	trailer->jumbo_max	= 0; /* Advertise pmtu discovery */
+
+	if (ack_reason == RXRPC_ACK_PING)
+		rxrpc_begin_rtt_probe(call, *_ack_serial, now, rxrpc_rtt_tx_ping);
+	if (whdr->flags & RXRPC_REQUEST_ACK)
+		call->rtt_last_req = now;
+	rxrpc_set_keepalive(call, now);
+	return nr_kv;
+}
+
+/*
+ * Transmit an ACK packet.
+ */
+static void rxrpc_send_ack_packet(struct rxrpc_call *call, int nr_kv, size_t len,
+				  rxrpc_serial_t serial, enum rxrpc_propose_ack_trace why)
+{
+	struct kvec *kv = call->local->kvec;
+	struct rxrpc_wire_header *whdr = kv[0].iov_base;
+	struct rxrpc_acktrailer *trailer = kv[2].iov_base + 3;
+	struct rxrpc_connection *conn;
+	struct rxrpc_ackpacket *ack = (struct rxrpc_ackpacket *)(whdr + 1);
+	struct msghdr msg;
+	int ret;
+
+	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		return;
+
+	conn = call->conn;
+
+	msg.msg_name	= &call->peer->srx.transport;
+	msg.msg_namelen	= call->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= MSG_SPLICE_PAGES;
+
+	trace_rxrpc_tx_ack(call->debug_id, serial,
+			   ntohl(ack->firstPacket),
+			   ntohl(ack->serial), ack->reason, ack->nAcks,
+			   ntohl(trailer->rwind), why);
+
+	rxrpc_inc_stat(call->rxnet, stat_tx_ack_send);
+
+	iov_iter_kvec(&msg.msg_iter, WRITE, kv, nr_kv, len);
+	rxrpc_local_dont_fragment(conn->local, why == rxrpc_propose_ack_ping_for_mtu_probe);
+
+	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
+	rxrpc_peer_mark_tx(call->peer);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_ack);
+		if (why == rxrpc_propose_ack_ping_for_mtu_probe &&
+		    ret == -EMSGSIZE)
+			rxrpc_input_probe_for_pmtud(conn, serial, true);
+	} else {
+		trace_rxrpc_tx_packet(call->debug_id, whdr,
+				      rxrpc_tx_point_call_ack);
+		if (why == rxrpc_propose_ack_ping_for_mtu_probe) {
+			call->peer->pmtud_pending = false;
+			call->peer->pmtud_probing = true;
+			call->conn->pmtud_probe = serial;
+			call->conn->pmtud_call = call->debug_id;
+			trace_rxrpc_pmtud_tx(call);
+		}
+	}
+	rxrpc_tx_backoff(call, ret);
+}
+
+/*
+ * Queue an ACK for immediate transmission.
+ */
+void rxrpc_send_ACK(struct rxrpc_call *call, u8 ack_reason,
+		    rxrpc_serial_t serial_to_ack, enum rxrpc_propose_ack_trace why)
+{
+	struct kvec *kv = call->local->kvec;
+	rxrpc_serial_t ack_serial;
+	size_t len;
+	int nr_kv;
+
+	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		return;
+
+	rxrpc_inc_stat(call->rxnet, stat_tx_acks[ack_reason]);
+
+	nr_kv = rxrpc_alloc_ack(call, call->ackr_wtop - call->ackr_window);
+	if (nr_kv < 0) {
+		kleave(" = -ENOMEM");
+		return;
+	}
+
+	nr_kv = rxrpc_fill_out_ack(call, nr_kv, ack_reason, serial_to_ack, &ack_serial);
+	len  = kv[0].iov_len;
+	len += kv[1].iov_len;
+	len += kv[2].iov_len;
+
+	/* Extend a path MTU probe ACK. */
+	if (why == rxrpc_propose_ack_ping_for_mtu_probe) {
+		size_t probe_mtu = call->peer->pmtud_trial + sizeof(struct rxrpc_wire_header);
+
+		if (len > probe_mtu)
+			goto skip;
+		while (len < probe_mtu) {
+			size_t part = umin(probe_mtu - len, PAGE_SIZE);
+
+			kv[nr_kv].iov_base = page_address(ZERO_PAGE(0));
+			kv[nr_kv].iov_len = part;
+			len += part;
+			nr_kv++;
+		}
+	}
+
+	call->ackr_nr_unacked = 0;
+	atomic_set(&call->ackr_nr_consumed, 0);
+	clear_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
+
+	trace_rxrpc_send_ack(call, why, ack_reason, ack_serial);
+	rxrpc_send_ack_packet(call, nr_kv, len, ack_serial, why);
+skip:
+	rxrpc_free_ack(call);
+}
+
+/*
+ * Send an ACK probe for path MTU discovery.
+ */
+void rxrpc_send_probe_for_pmtud(struct rxrpc_call *call)
+{
+	rxrpc_send_ACK(call, RXRPC_ACK_PING, 0,
+		       rxrpc_propose_ack_ping_for_mtu_probe);
+}
+
+/*
+ * Send an ABORT call packet.
+ */
+int rxrpc_send_abort_packet(struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_abort_buffer pkt;
+	struct msghdr msg;
+	struct kvec iov[1];
+	rxrpc_serial_t serial;
+	int ret;
+
+	/* Don't bother sending aborts for a client call once the server has
+	 * hard-ACK'd all of its request data.  After that point, we're not
+	 * going to stop the operation proceeding, and whilst we might limit
+	 * the reply, it's not worth it if we can send a new call on the same
+	 * channel instead, thereby closing off this call.
+	 */
+	if (rxrpc_is_client_call(call) &&
+	    test_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags))
+		return 0;
+
+	if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
+		return -ECONNRESET;
+
+	conn = call->conn;
+
+	msg.msg_name	= &call->peer->srx.transport;
+	msg.msg_namelen	= call->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	pkt.whdr.epoch		= htonl(conn->proto.epoch);
+	pkt.whdr.cid		= htonl(call->cid);
+	pkt.whdr.callNumber	= htonl(call->call_id);
+	pkt.whdr.seq		= 0;
+	pkt.whdr.type		= RXRPC_PACKET_TYPE_ABORT;
+	pkt.whdr.flags		= conn->out_clientflag;
+	pkt.whdr.userStatus	= 0;
+	pkt.whdr.securityIndex	= call->security_ix;
+	pkt.whdr._rsvd		= 0;
+	pkt.whdr.serviceId	= htons(call->dest_srx.srx_service);
+	pkt.abort_code		= htonl(call->abort_code);
+
+	iov[0].iov_base	= &pkt;
+	iov[0].iov_len	= sizeof(pkt);
+
+	serial = rxrpc_get_next_serial(conn);
+	pkt.whdr.serial = htonl(serial);
+
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, sizeof(pkt));
+	ret = do_udp_sendmsg(conn->local->socket, &msg, sizeof(pkt));
+	rxrpc_peer_mark_tx(conn->peer);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(call->debug_id, serial, ret,
+				    rxrpc_tx_point_call_abort);
+	else
+		trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr,
+				      rxrpc_tx_point_call_abort);
+	rxrpc_tx_backoff(call, ret);
+	return ret;
+}
+
+/*
+ * Prepare a (sub)packet for transmission.
+ */
+static size_t rxrpc_prepare_data_subpacket(struct rxrpc_call *call,
+					   struct rxrpc_send_data_req *req,
+					   struct rxrpc_txbuf *txb,
+					   struct rxrpc_wire_header *whdr,
+					   rxrpc_serial_t serial, int subpkt)
+{
+	struct rxrpc_jumbo_header *jumbo = txb->data - sizeof(*jumbo);
+	enum rxrpc_req_ack_trace why;
+	struct rxrpc_connection *conn = call->conn;
+	struct kvec *kv = &call->local->kvec[1 + subpkt];
+	size_t len = txb->pkt_len;
+	bool last;
+	u8 flags;
+
+	_enter("%x,%zd", txb->seq, len);
+
+	txb->serial = serial;
+
+	if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
+	    txb->seq == 1)
+		whdr->userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
+
+	txb->flags &= ~RXRPC_REQUEST_ACK;
+	flags = txb->flags & RXRPC_TXBUF_WIRE_FLAGS;
+	last = txb->flags & RXRPC_LAST_PACKET;
+
+	if (subpkt < req->n - 1) {
+		len = RXRPC_JUMBO_DATALEN;
+		goto dont_set_request_ack;
+	}
+
+	/* If our RTT cache needs working on, request an ACK.  Also request
+	 * ACKs if a DATA packet appears to have been lost.
+	 *
+	 * However, we mustn't request an ACK on the last reply packet of a
+	 * service call, lest OpenAFS incorrectly send us an ACK with some
+	 * soft-ACKs in it and then never follow up with a proper hard ACK.
+	 */
+	if (last && rxrpc_sending_to_client(txb))
+		why = rxrpc_reqack_no_srv_last;
+	else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events))
+		why = rxrpc_reqack_ack_lost;
+	else if (txb->flags & RXRPC_TXBUF_RESENT)
+		why = rxrpc_reqack_retrans;
+	else if (call->cong_ca_state == RXRPC_CA_SLOW_START && call->cong_cwnd <= RXRPC_MIN_CWND)
+		why = rxrpc_reqack_slow_start;
+	else if (call->tx_winsize <= 2)
+		why = rxrpc_reqack_small_txwin;
+	else if (call->rtt_count < 3)
+		why = rxrpc_reqack_more_rtt;
+	else if (ktime_before(ktime_add_ms(call->rtt_last_req, 1000), ktime_get_real()))
+		why = rxrpc_reqack_old_rtt;
+	else if (!last && !after(READ_ONCE(call->send_top), txb->seq))
+		why = rxrpc_reqack_app_stall;
+	else if (call->tx_winsize <= (2 * req->n) || call->cong_cwnd <= (2 * req->n))
+		why = rxrpc_reqack_jumbo_win;
+	else
+		goto dont_set_request_ack;
+
+	rxrpc_inc_stat(call->rxnet, stat_why_req_ack[why]);
+	trace_rxrpc_req_ack(call->debug_id, txb->seq, why);
+	if (why != rxrpc_reqack_no_srv_last) {
+		flags |= RXRPC_REQUEST_ACK;
+		trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, -1, serial);
+		call->rtt_last_req = req->now;
+	}
+dont_set_request_ack:
+
+	/* There's a jumbo header prepended to the data if we need it. */
+	if (subpkt < req->n - 1)
+		flags |= RXRPC_JUMBO_PACKET;
+	else
+		flags &= ~RXRPC_JUMBO_PACKET;
+	if (subpkt == 0) {
+		whdr->flags	= flags;
+		whdr->cksum	= txb->cksum;
+		kv->iov_base	= txb->data;
+	} else {
+		jumbo->flags	= flags;
+		jumbo->pad	= 0;
+		jumbo->cksum	= txb->cksum;
+		kv->iov_base	= jumbo;
+		len += sizeof(*jumbo);
+	}
+
+	trace_rxrpc_tx_data(call, txb->seq, txb->serial, flags, req->trace);
+	kv->iov_len = len;
+	return len;
+}
+
+/*
+ * Prepare a transmission queue object for initial transmission.  Returns the
+ * number of microseconds since the transmission queue base timestamp.
+ */
+static unsigned int rxrpc_prepare_txqueue(struct rxrpc_txqueue *tq,
+					  struct rxrpc_send_data_req *req)
+{
+	if (!tq)
+		return 0;
+	if (tq->xmit_ts_base == KTIME_MIN) {
+		tq->xmit_ts_base = req->now;
+		return 0;
+	}
+	return ktime_to_us(ktime_sub(req->now, tq->xmit_ts_base));
+}
+
+/*
+ * Prepare a (jumbo) packet for transmission.
+ */
+static size_t rxrpc_prepare_data_packet(struct rxrpc_call *call,
+					struct rxrpc_send_data_req *req,
+					struct rxrpc_wire_header *whdr)
+{
+	struct rxrpc_txqueue *tq = req->tq;
+	rxrpc_serial_t serial;
+	unsigned int xmit_ts;
+	rxrpc_seq_t seq = req->seq;
+	size_t len = 0;
+	bool start_tlp = false;
+
+	trace_rxrpc_tq(call, tq, seq, rxrpc_tq_transmit);
+
+	/* Each transmission of a Tx packet needs a new serial number */
+	serial = rxrpc_get_next_serials(call->conn, req->n);
+
+	whdr->epoch		= htonl(call->conn->proto.epoch);
+	whdr->cid		= htonl(call->cid);
+	whdr->callNumber	= htonl(call->call_id);
+	whdr->seq		= htonl(seq);
+	whdr->serial		= htonl(serial);
+	whdr->type		= RXRPC_PACKET_TYPE_DATA;
+	whdr->flags		= 0;
+	whdr->userStatus	= 0;
+	whdr->securityIndex	= call->security_ix;
+	whdr->_rsvd		= 0;
+	whdr->serviceId		= htons(call->conn->service_id);
+
+	call->tx_last_serial = serial + req->n - 1;
+	call->tx_last_sent = req->now;
+	xmit_ts = rxrpc_prepare_txqueue(tq, req);
+	prefetch(tq->next);
+
+	for (int i = 0;;) {
+		int ix = seq & RXRPC_TXQ_MASK;
+		struct rxrpc_txbuf *txb = tq->bufs[seq & RXRPC_TXQ_MASK];
+
+		_debug("prep[%u] tq=%x q=%x", i, tq->qbase, seq);
+
+		/* Record (re-)transmission for RACK [RFC8985 6.1]. */
+		if (__test_and_clear_bit(ix, &tq->segment_lost))
+			call->tx_nr_lost--;
+		if (req->retrans) {
+			__set_bit(ix, &tq->ever_retransmitted);
+			__set_bit(ix, &tq->segment_retransmitted);
+			call->tx_nr_resent++;
+		} else {
+			call->tx_nr_sent++;
+			start_tlp = true;
+		}
+		tq->segment_xmit_ts[ix] = xmit_ts;
+		tq->segment_serial[ix] = serial;
+		if (i + 1 == req->n)
+			/* Only sample the last subpacket in a jumbo. */
+			__set_bit(ix, &tq->rtt_samples);
+		len += rxrpc_prepare_data_subpacket(call, req, txb, whdr, serial, i);
+		serial++;
+		seq++;
+		i++;
+		if (i >= req->n)
+			break;
+		if (!(seq & RXRPC_TXQ_MASK)) {
+			tq = tq->next;
+			trace_rxrpc_tq(call, tq, seq, rxrpc_tq_transmit_advance);
+			xmit_ts = rxrpc_prepare_txqueue(tq, req);
+		}
+	}
+
+	/* Set timeouts */
+	if (req->tlp_probe) {
+		/* Sending TLP loss probe [RFC8985 7.3]. */
+		call->tlp_serial = serial - 1;
+		call->tlp_seq = seq - 1;
+	} else if (start_tlp) {
+		/* Schedule TLP loss probe [RFC8985 7.2]. */
+		ktime_t pto;
+
+		if (!test_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags))
+			 /* The first packet may take longer to elicit a response. */
+			pto = NSEC_PER_SEC;
+		else
+			pto = rxrpc_tlp_calc_pto(call, req->now);
+
+		call->rack_timer_mode = RXRPC_CALL_RACKTIMER_TLP_PTO;
+		call->rack_timo_at = ktime_add(req->now, pto);
+		trace_rxrpc_rack_timer(call, pto, false);
+		trace_rxrpc_timer_set(call, pto, rxrpc_timer_trace_rack_tlp_pto);
+	}
+
+	if (!test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags)) {
+		ktime_t delay = ms_to_ktime(READ_ONCE(call->next_rx_timo));
+
+		call->expect_rx_by = ktime_add(req->now, delay);
+		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_expect_rx);
+	}
+
+	rxrpc_set_keepalive(call, req->now);
+	page_frag_free(whdr);
+	return len;
+}
+
+/*
+ * Send one or more packets through the transport endpoint
+ */
+void rxrpc_send_data_packet(struct rxrpc_call *call, struct rxrpc_send_data_req *req)
+{
+	struct rxrpc_wire_header *whdr;
+	struct rxrpc_connection *conn = call->conn;
+	enum rxrpc_tx_point frag;
+	struct rxrpc_txqueue *tq = req->tq;
+	struct rxrpc_txbuf *txb;
+	struct msghdr msg;
+	rxrpc_seq_t seq = req->seq;
+	size_t len = sizeof(*whdr);
+	bool new_call = test_bit(RXRPC_CALL_BEGAN_RX_TIMER, &call->flags);
+	int ret, stat_ix;
+
+	_enter("%x,%x-%x", tq->qbase, seq, seq + req->n - 1);
+
+	whdr = page_frag_alloc(&call->local->tx_alloc, sizeof(*whdr), GFP_NOFS);
+	if (!whdr)
+		return; /* Drop the packet if no memory. */
+
+	call->local->kvec[0].iov_base = whdr;
+	call->local->kvec[0].iov_len = sizeof(*whdr);
+
+	stat_ix = umin(req->n, ARRAY_SIZE(call->rxnet->stat_tx_jumbo)) - 1;
+	atomic_inc(&call->rxnet->stat_tx_jumbo[stat_ix]);
+
+	len += rxrpc_prepare_data_packet(call, req, whdr);
+	txb = tq->bufs[seq & RXRPC_TXQ_MASK];
+
+	iov_iter_kvec(&msg.msg_iter, WRITE, call->local->kvec, 1 + req->n, len);
+
+	msg.msg_name	= &call->peer->srx.transport;
+	msg.msg_namelen	= call->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= MSG_SPLICE_PAGES;
+
+	/* Send the packet with the don't fragment bit set unless we think it's
+	 * too big or if this is a retransmission.
+	 */
+	if (seq == call->tx_transmitted + 1 &&
+	    len >= sizeof(struct rxrpc_wire_header) + call->peer->max_data) {
+		rxrpc_local_dont_fragment(conn->local, false);
+		frag = rxrpc_tx_point_call_data_frag;
+	} else {
+		rxrpc_local_dont_fragment(conn->local, true);
+		frag = rxrpc_tx_point_call_data_nofrag;
+	}
+
+	/* Track what we've attempted to transmit at least once so that the
+	 * retransmission algorithm doesn't try to resend what we haven't sent
+	 * yet.
+	 */
+	if (seq == call->tx_transmitted + 1)
+		call->tx_transmitted = seq + req->n - 1;
+
+	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
+		static int lose;
+
+		if ((lose++ & 7) == 7) {
+			ret = 0;
+			trace_rxrpc_tx_data(call, txb->seq, txb->serial, txb->flags,
+					    rxrpc_txdata_inject_loss);
+			rxrpc_peer_mark_tx(conn->peer);
+			goto done;
+		}
+	}
+
+	/* send the packet by UDP
+	 * - returns -EMSGSIZE if UDP would have to fragment the packet
+	 *   to go out of the interface
+	 *   - in which case, we'll have processed the ICMP error
+	 *     message and update the peer record
+	 */
+	rxrpc_inc_stat(call->rxnet, stat_tx_data_send);
+	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
+	rxrpc_peer_mark_tx(conn->peer);
+
+	if (ret == -EMSGSIZE) {
+		rxrpc_inc_stat(call->rxnet, stat_tx_data_send_msgsize);
+		trace_rxrpc_tx_packet(call->debug_id, whdr, frag);
+		ret = 0;
+	} else if (ret < 0) {
+		rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail);
+		trace_rxrpc_tx_fail(call->debug_id, txb->serial, ret, frag);
+	} else {
+		trace_rxrpc_tx_packet(call->debug_id, whdr, frag);
+	}
+
+	rxrpc_tx_backoff(call, ret);
+
+	if (ret < 0) {
+		/* Cancel the call if the initial transmission fails or if we
+		 * hit due to network routing issues that aren't going away
+		 * anytime soon.  The layer above can arrange the
+		 * retransmission.
+		 */
+		if (new_call ||
+		    ret == -ENETUNREACH ||
+		    ret == -EHOSTUNREACH ||
+		    ret == -ECONNREFUSED)
+			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+						  RX_USER_ABORT, ret);
+	}
+
+done:
+	_leave(" = %d [%u]", ret, call->peer->max_data);
+}
+
+/*
+ * Transmit a connection-level abort.
+ */
+void rxrpc_send_conn_abort(struct rxrpc_connection *conn)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	__be32 word;
+	size_t len;
+	u32 serial;
+	int ret;
+
+	msg.msg_name	= &conn->peer->srx.transport;
+	msg.msg_namelen	= conn->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(conn->proto.cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_ABORT;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	word		= htonl(conn->abort_code);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= &word;
+	iov[1].iov_len	= sizeof(word);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = rxrpc_get_next_serial(conn);
+	whdr.serial = htonl(serial);
+
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
+	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_conn_abort);
+		_debug("sendmsg failed: %d", ret);
+		return;
+	}
+
+	trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
+
+	rxrpc_peer_mark_tx(conn->peer);
+}
+
+/*
+ * Reject a packet through the local endpoint.
+ */
+void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	struct rxrpc_wire_header whdr;
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t size;
+	__be32 code;
+	int ret, ioc;
+
+	if (sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
+		return; /* Never abort an abort. */
+
+	rxrpc_see_skb(skb, rxrpc_skb_see_reject);
+
+	iov[0].iov_base = &whdr;
+	iov[0].iov_len = sizeof(whdr);
+	iov[1].iov_base = &code;
+	iov[1].iov_len = sizeof(code);
+
+	msg.msg_name = &srx.transport;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags = 0;
+
+	whdr = (struct rxrpc_wire_header) {
+		.epoch		= htonl(sp->hdr.epoch),
+		.cid		= htonl(sp->hdr.cid),
+		.callNumber	= htonl(sp->hdr.callNumber),
+		.serviceId	= htons(sp->hdr.serviceId),
+		.flags		= ~sp->hdr.flags & RXRPC_CLIENT_INITIATED,
+	};
+
+	switch (skb->mark) {
+	case RXRPC_SKB_MARK_REJECT_BUSY:
+		whdr.type = RXRPC_PACKET_TYPE_BUSY;
+		size = sizeof(whdr);
+		ioc = 1;
+		break;
+	case RXRPC_SKB_MARK_REJECT_CONN_ABORT:
+		whdr.callNumber	= 0;
+		fallthrough;
+	case RXRPC_SKB_MARK_REJECT_ABORT:
+		whdr.type = RXRPC_PACKET_TYPE_ABORT;
+		code = htonl(skb->priority);
+		size = sizeof(whdr) + sizeof(code);
+		ioc = 2;
+		break;
+	default:
+		return;
+	}
+
+	if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
+		msg.msg_namelen = srx.transport_len;
+
+		iov_iter_kvec(&msg.msg_iter, WRITE, iov, ioc, size);
+		ret = do_udp_sendmsg(local->socket, &msg, size);
+		if (ret < 0)
+			trace_rxrpc_tx_fail(local->debug_id, 0, ret,
+					    rxrpc_tx_point_reject);
+		else
+			trace_rxrpc_tx_packet(local->debug_id, &whdr,
+					      rxrpc_tx_point_reject);
+	}
+}
+
+/*
+ * Send a VERSION reply to a peer as a keepalive.
+ */
+void rxrpc_send_keepalive(struct rxrpc_peer *peer)
+{
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	int ret;
+
+	_enter("");
+
+	msg.msg_name	= &peer->srx.transport;
+	msg.msg_namelen	= peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(peer->local->rxnet->epoch);
+	whdr.cid	= 0;
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.serial	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
+	whdr.flags	= RXRPC_LAST_PACKET;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = 0;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= 0;
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= (char *)rxrpc_keepalive_string;
+	iov[1].iov_len	= sizeof(rxrpc_keepalive_string);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 2, len);
+	ret = do_udp_sendmsg(peer->local->socket, &msg, len);
+	if (ret < 0)
+		trace_rxrpc_tx_fail(peer->debug_id, 0, ret,
+				    rxrpc_tx_point_version_keepalive);
+	else
+		trace_rxrpc_tx_packet(peer->debug_id, &whdr,
+				      rxrpc_tx_point_version_keepalive);
+
+	rxrpc_peer_mark_tx(peer);
+	_leave("");
+}
+
+/*
+ * Send a RESPONSE message.
+ */
+void rxrpc_send_response(struct rxrpc_connection *conn, struct sk_buff *response)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(response);
+	struct scatterlist sg[16];
+	struct bio_vec *bvec = conn->local->bvec;
+	struct msghdr msg;
+	size_t len = sp->resp.len;
+	__be32 wserial;
+	u32 serial = 0;
+	int ret, nr_sg;
+
+	_enter("C=%x,%x", conn->debug_id, sp->resp.challenge_serial);
+
+	sg_init_table(sg, ARRAY_SIZE(sg));
+	ret = skb_to_sgvec(response, sg, 0, len);
+	if (ret < 0)
+		goto fail;
+	nr_sg = ret;
+	ret = -EIO;
+	if (WARN_ON_ONCE(nr_sg > ARRAY_SIZE(conn->local->bvec)))
+		goto fail;
+
+	for (int i = 0; i < nr_sg; i++)
+		bvec_set_page(&bvec[i], sg_page(&sg[i]), sg[i].length, sg[i].offset);
+
+	iov_iter_bvec(&msg.msg_iter, WRITE, bvec, nr_sg, len);
+
+	msg.msg_name	= &conn->peer->srx.transport;
+	msg.msg_namelen	= conn->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= MSG_SPLICE_PAGES;
+
+	serial = rxrpc_get_next_serials(conn, 1);
+	wserial = htonl(serial);
+
+	trace_rxrpc_tx_response(conn, serial, sp);
+
+	ret = skb_store_bits(response, offsetof(struct rxrpc_wire_header, serial),
+			     &wserial, sizeof(wserial));
+	if (ret < 0)
+		goto fail;
+
+	rxrpc_local_dont_fragment(conn->local, false);
+
+	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
+	if (ret < 0)
+		goto fail;
+
+	rxrpc_peer_mark_tx(conn->peer);
+	return;
+
+fail:
+	trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+			    rxrpc_tx_point_response);
+	kleave(" = %d", ret);
+}
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
new file mode 100644
index 000000000..9d02448ac
--- /dev/null
+++ b/net/rxrpc/peer_event.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Peer event handling, typically ICMP messages.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+static void rxrpc_store_error(struct rxrpc_peer *, struct sk_buff *);
+static void rxrpc_distribute_error(struct rxrpc_peer *, struct sk_buff *,
+				   enum rxrpc_call_completion, int);
+
+/*
+ * Find the peer associated with a local error.
+ */
+static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local,
+						      const struct sk_buff *skb,
+						      struct sockaddr_rxrpc *srx)
+{
+	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+
+	_enter("");
+
+	memset(srx, 0, sizeof(*srx));
+	srx->transport_type = local->srx.transport_type;
+	srx->transport_len = local->srx.transport_len;
+	srx->transport.family = local->srx.transport.family;
+
+	/* Can we see an ICMP4 packet on an ICMP6 listening socket?  and vice
+	 * versa?
+	 */
+	switch (srx->transport.family) {
+	case AF_INET:
+		srx->transport_len = sizeof(srx->transport.sin);
+		srx->transport.family = AF_INET;
+		srx->transport.sin.sin_port = serr->port;
+		switch (serr->ee.ee_origin) {
+		case SO_EE_ORIGIN_ICMP:
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in_addr));
+			break;
+		case SO_EE_ORIGIN_ICMP6:
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset + 12,
+			       sizeof(struct in_addr));
+			break;
+		default:
+			memcpy(&srx->transport.sin.sin_addr, &ip_hdr(skb)->saddr,
+			       sizeof(struct in_addr));
+			break;
+		}
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		switch (serr->ee.ee_origin) {
+		case SO_EE_ORIGIN_ICMP6:
+			srx->transport.sin6.sin6_port = serr->port;
+			memcpy(&srx->transport.sin6.sin6_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in6_addr));
+			break;
+		case SO_EE_ORIGIN_ICMP:
+			srx->transport_len = sizeof(srx->transport.sin);
+			srx->transport.family = AF_INET;
+			srx->transport.sin.sin_port = serr->port;
+			memcpy(&srx->transport.sin.sin_addr,
+			       skb_network_header(skb) + serr->addr_offset,
+			       sizeof(struct in_addr));
+			break;
+		default:
+			memcpy(&srx->transport.sin6.sin6_addr,
+			       &ipv6_hdr(skb)->saddr,
+			       sizeof(struct in6_addr));
+			break;
+		}
+		break;
+#endif
+
+	default:
+		BUG();
+	}
+
+	return rxrpc_lookup_peer_rcu(local, srx);
+}
+
+/*
+ * Handle an MTU/fragmentation problem.
+ */
+static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
+{
+	unsigned int max_data;
+
+	/* wind down the local interface MTU */
+	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu)
+		peer->if_mtu = mtu;
+
+	if (mtu == 0) {
+		/* they didn't give us a size, estimate one */
+		mtu = peer->if_mtu;
+		if (mtu > 1500) {
+			mtu >>= 1;
+			if (mtu < 1500)
+				mtu = 1500;
+		} else {
+			mtu -= 100;
+			if (mtu < peer->hdrsize)
+				mtu = peer->hdrsize + 4;
+		}
+	}
+
+	max_data = max_t(int, mtu - peer->hdrsize, 500);
+	if (max_data < peer->max_data) {
+		if (peer->pmtud_good > max_data)
+			peer->pmtud_good = max_data;
+		if (peer->pmtud_bad > max_data + 1)
+			peer->pmtud_bad = max_data + 1;
+
+		trace_rxrpc_pmtud_reduce(peer, 0, max_data, rxrpc_pmtud_reduce_icmp);
+		peer->max_data = max_data;
+	}
+}
+
+/*
+ * Handle an error received on the local endpoint.
+ */
+void rxrpc_input_error(struct rxrpc_local *local, struct sk_buff *skb)
+{
+	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_peer *peer = NULL;
+
+	_enter("L=%x", local->debug_id);
+
+	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
+		_leave("UDP empty message");
+		return;
+	}
+
+	rcu_read_lock();
+	peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx);
+	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input_error))
+		peer = NULL;
+	rcu_read_unlock();
+	if (!peer)
+		return;
+
+	trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
+
+	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
+	     serr->ee.ee_type == ICMP_DEST_UNREACH &&
+	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
+		rxrpc_adjust_mtu(peer, serr->ee.ee_info);
+		goto out;
+	}
+
+	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 &&
+	     serr->ee.ee_type == ICMPV6_PKT_TOOBIG &&
+	     serr->ee.ee_code == 0)) {
+		rxrpc_adjust_mtu(peer, serr->ee.ee_info);
+		goto out;
+	}
+
+	rxrpc_store_error(peer, skb);
+out:
+	rxrpc_put_peer(peer, rxrpc_peer_put_input_error);
+}
+
+/*
+ * Map an error report to error codes on the peer record.
+ */
+static void rxrpc_store_error(struct rxrpc_peer *peer, struct sk_buff *skb)
+{
+	enum rxrpc_call_completion compl = RXRPC_CALL_NETWORK_ERROR;
+	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+	struct sock_extended_err *ee = &serr->ee;
+	int err = ee->ee_errno;
+
+	_enter("");
+
+	switch (ee->ee_origin) {
+	case SO_EE_ORIGIN_NONE:
+	case SO_EE_ORIGIN_LOCAL:
+		compl = RXRPC_CALL_LOCAL_ERROR;
+		break;
+
+	case SO_EE_ORIGIN_ICMP6:
+		if (err == EACCES)
+			err = EHOSTUNREACH;
+		fallthrough;
+	case SO_EE_ORIGIN_ICMP:
+	default:
+		break;
+	}
+
+	rxrpc_distribute_error(peer, skb, compl, err);
+}
+
+/*
+ * Distribute an error that occurred on a peer.
+ */
+static void rxrpc_distribute_error(struct rxrpc_peer *peer, struct sk_buff *skb,
+				   enum rxrpc_call_completion compl, int err)
+{
+	struct rxrpc_call *call;
+	HLIST_HEAD(error_targets);
+
+	spin_lock_irq(&peer->lock);
+	hlist_move_list(&peer->error_targets, &error_targets);
+
+	while (!hlist_empty(&error_targets)) {
+		call = hlist_entry(error_targets.first,
+				   struct rxrpc_call, error_link);
+		hlist_del_init(&call->error_link);
+		spin_unlock_irq(&peer->lock);
+
+		rxrpc_see_call(call, rxrpc_call_see_distribute_error);
+		rxrpc_set_call_completion(call, compl, 0, -err);
+		rxrpc_input_call_event(call);
+
+		spin_lock_irq(&peer->lock);
+	}
+
+	spin_unlock_irq(&peer->lock);
+}
+
+/*
+ * Reconstruct the last transmission time.  The difference calculated should be
+ * valid provided no more than ~68 years elapsed since the last transmission.
+ */
+static time64_t rxrpc_peer_get_tx_mark(const struct rxrpc_peer *peer, time64_t base)
+{
+	s32 last_tx_at = READ_ONCE(peer->last_tx_at);
+	s32 base_lsw = base;
+	s32 diff = last_tx_at - base_lsw;
+
+	diff = clamp(diff, -RXRPC_KEEPALIVE_TIME, RXRPC_KEEPALIVE_TIME);
+
+	return diff + base;
+}
+
+/*
+ * Perform keep-alive pings.
+ */
+static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet,
+					  struct list_head *collector,
+					  time64_t base,
+					  u8 cursor)
+{
+	struct rxrpc_peer *peer;
+	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+	time64_t keepalive_at;
+	bool use;
+	int slot;
+
+	spin_lock_bh(&rxnet->peer_hash_lock);
+
+	while (!list_empty(collector)) {
+		peer = list_entry(collector->next,
+				  struct rxrpc_peer, keepalive_link);
+
+		list_del_init(&peer->keepalive_link);
+		if (!rxrpc_get_peer_maybe(peer, rxrpc_peer_get_keepalive))
+			continue;
+
+		use = __rxrpc_use_local(peer->local, rxrpc_local_use_peer_keepalive);
+		spin_unlock_bh(&rxnet->peer_hash_lock);
+
+		if (use) {
+			keepalive_at = rxrpc_peer_get_tx_mark(peer, base) + RXRPC_KEEPALIVE_TIME;
+			slot = keepalive_at - base;
+			_debug("%02x peer %u t=%d {%pISp}",
+			       cursor, peer->debug_id, slot, &peer->srx.transport);
+
+			if (keepalive_at <= base ||
+			    keepalive_at > base + RXRPC_KEEPALIVE_TIME) {
+				rxrpc_send_keepalive(peer);
+				slot = RXRPC_KEEPALIVE_TIME;
+			}
+
+			/* A transmission to this peer occurred since last we
+			 * examined it so put it into the appropriate future
+			 * bucket.
+			 */
+			slot += cursor;
+			slot &= mask;
+			spin_lock_bh(&rxnet->peer_hash_lock);
+			list_add_tail(&peer->keepalive_link,
+				      &rxnet->peer_keepalive[slot & mask]);
+			spin_unlock_bh(&rxnet->peer_hash_lock);
+			rxrpc_unuse_local(peer->local, rxrpc_local_unuse_peer_keepalive);
+		}
+		rxrpc_put_peer(peer, rxrpc_peer_put_keepalive);
+		spin_lock_bh(&rxnet->peer_hash_lock);
+	}
+
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+}
+
+/*
+ * Perform keep-alive pings with VERSION packets to keep any NAT alive.
+ */
+void rxrpc_peer_keepalive_worker(struct work_struct *work)
+{
+	struct rxrpc_net *rxnet =
+		container_of(work, struct rxrpc_net, peer_keepalive_work);
+	const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+	time64_t base, now, delay;
+	u8 cursor, stop;
+	LIST_HEAD(collector);
+
+	now = ktime_get_seconds();
+	base = rxnet->peer_keepalive_base;
+	cursor = rxnet->peer_keepalive_cursor;
+	_enter("%lld,%u", base - now, cursor);
+
+	if (!rxnet->live)
+		return;
+
+	/* Remove to a temporary list all the peers that are currently lodged
+	 * in expired buckets plus all new peers.
+	 *
+	 * Everything in the bucket at the cursor is processed this
+	 * second; the bucket at cursor + 1 goes at now + 1s and so
+	 * on...
+	 */
+	spin_lock_bh(&rxnet->peer_hash_lock);
+	list_splice_init(&rxnet->peer_keepalive_new, &collector);
+
+	stop = cursor + ARRAY_SIZE(rxnet->peer_keepalive);
+	while (base <= now && (s8)(cursor - stop) < 0) {
+		list_splice_tail_init(&rxnet->peer_keepalive[cursor & mask],
+				      &collector);
+		base++;
+		cursor++;
+	}
+
+	base = now;
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+
+	rxnet->peer_keepalive_base = base;
+	rxnet->peer_keepalive_cursor = cursor;
+	rxrpc_peer_keepalive_dispatch(rxnet, &collector, base, cursor);
+	ASSERT(list_empty(&collector));
+
+	/* Schedule the timer for the next occupied timeslot. */
+	cursor = rxnet->peer_keepalive_cursor;
+	stop = cursor + RXRPC_KEEPALIVE_TIME - 1;
+	for (; (s8)(cursor - stop) < 0; cursor++) {
+		if (!list_empty(&rxnet->peer_keepalive[cursor & mask]))
+			break;
+		base++;
+	}
+
+	now = ktime_get_seconds();
+	delay = base - now;
+	if (delay < 1)
+		delay = 1;
+	delay *= HZ;
+	if (rxnet->live)
+		timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
+
+	_leave("");
+}
+
+/*
+ * Do path MTU probing.
+ */
+void rxrpc_input_probe_for_pmtud(struct rxrpc_connection *conn, rxrpc_serial_t acked_serial,
+				 bool sendmsg_fail)
+{
+	struct rxrpc_peer *peer = conn->peer;
+	unsigned int max_data = peer->max_data;
+	int good, trial, bad, jumbo;
+
+	good  = peer->pmtud_good;
+	trial = peer->pmtud_trial;
+	bad   = peer->pmtud_bad;
+	if (good >= bad - 1) {
+		conn->pmtud_probe = 0;
+		peer->pmtud_lost = false;
+		return;
+	}
+
+	if (!peer->pmtud_probing)
+		goto send_probe;
+
+	if (sendmsg_fail || after(acked_serial, conn->pmtud_probe)) {
+		/* Retry a lost probe. */
+		if (!peer->pmtud_lost) {
+			trace_rxrpc_pmtud_lost(conn, acked_serial);
+			conn->pmtud_probe = 0;
+			peer->pmtud_lost = true;
+			goto send_probe;
+		}
+
+		/* The probed size didn't seem to get through. */
+		bad = trial;
+		peer->pmtud_bad = bad;
+		if (bad <= max_data)
+			max_data = bad - 1;
+	} else {
+		/* It did get through. */
+		good = trial;
+		peer->pmtud_good = good;
+		if (good > max_data)
+			max_data = good;
+	}
+
+	max_data = umin(max_data, peer->ackr_max_data);
+	if (max_data != peer->max_data)
+		peer->max_data = max_data;
+
+	jumbo = max_data + sizeof(struct rxrpc_jumbo_header);
+	jumbo /= RXRPC_JUMBO_SUBPKTLEN;
+	peer->pmtud_jumbo = jumbo;
+
+	trace_rxrpc_pmtud_rx(conn, acked_serial);
+	conn->pmtud_probe = 0;
+	peer->pmtud_lost = false;
+
+	if (good < RXRPC_JUMBO(2) && bad > RXRPC_JUMBO(2))
+		trial = RXRPC_JUMBO(2);
+	else if (good < RXRPC_JUMBO(4) && bad > RXRPC_JUMBO(4))
+		trial = RXRPC_JUMBO(4);
+	else if (good < RXRPC_JUMBO(3) && bad > RXRPC_JUMBO(3))
+		trial = RXRPC_JUMBO(3);
+	else if (good < RXRPC_JUMBO(6) && bad > RXRPC_JUMBO(6))
+		trial = RXRPC_JUMBO(6);
+	else if (good < RXRPC_JUMBO(5) && bad > RXRPC_JUMBO(5))
+		trial = RXRPC_JUMBO(5);
+	else if (good < RXRPC_JUMBO(8) && bad > RXRPC_JUMBO(8))
+		trial = RXRPC_JUMBO(8);
+	else if (good < RXRPC_JUMBO(7) && bad > RXRPC_JUMBO(7))
+		trial = RXRPC_JUMBO(7);
+	else
+		trial = (good + bad) / 2;
+	peer->pmtud_trial = trial;
+
+	if (good >= bad)
+		return;
+
+send_probe:
+	peer->pmtud_pending = true;
+}
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
new file mode 100644
index 000000000..fa9a406e1
--- /dev/null
+++ b/net/rxrpc/peer_object.c
@@ -0,0 +1,560 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC remote transport endpoint record management
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+#include "ar-internal.h"
+
+static const struct sockaddr_rxrpc rxrpc_null_addr;
+
+/*
+ * Hash a peer key.
+ */
+static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	const u16 *p;
+	unsigned int i, size;
+	unsigned long hash_key;
+
+	_enter("");
+
+	hash_key = (unsigned long)local / __alignof__(*local);
+	hash_key += srx->transport_type;
+	hash_key += srx->transport_len;
+	hash_key += srx->transport.family;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin.sin_addr);
+		p = (u16 *)&srx->transport.sin.sin_addr;
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		hash_key += (u16 __force)srx->transport.sin.sin_port;
+		size = sizeof(srx->transport.sin6.sin6_addr);
+		p = (u16 *)&srx->transport.sin6.sin6_addr;
+		break;
+#endif
+	default:
+		WARN(1, "AF_RXRPC: Unsupported transport address family\n");
+		return 0;
+	}
+
+	/* Step through the peer address in 16-bit portions for speed */
+	for (i = 0; i < size; i += sizeof(*p), p++)
+		hash_key += *p;
+
+	_leave(" 0x%lx", hash_key);
+	return hash_key;
+}
+
+/*
+ * Compare a peer to a key.  Return -ve, 0 or +ve to indicate less than, same
+ * or greater than.
+ *
+ * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
+ * buckets and mid-bucket insertion, so we don't make full use of this
+ * information at this point.
+ */
+static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
+			       struct rxrpc_local *local,
+			       const struct sockaddr_rxrpc *srx,
+			       unsigned long hash_key)
+{
+	long diff;
+
+	diff = ((peer->hash_key - hash_key) ?:
+		((unsigned long)peer->local - (unsigned long)local) ?:
+		(peer->srx.transport_type - srx->transport_type) ?:
+		(peer->srx.transport_len - srx->transport_len) ?:
+		(peer->srx.transport.family - srx->transport.family));
+	if (diff != 0)
+		return diff;
+
+	switch (srx->transport.family) {
+	case AF_INET:
+		return ((u16 __force)peer->srx.transport.sin.sin_port -
+			(u16 __force)srx->transport.sin.sin_port) ?:
+			memcmp(&peer->srx.transport.sin.sin_addr,
+			       &srx->transport.sin.sin_addr,
+			       sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		return ((u16 __force)peer->srx.transport.sin6.sin6_port -
+			(u16 __force)srx->transport.sin6.sin6_port) ?:
+			memcmp(&peer->srx.transport.sin6.sin6_addr,
+			       &srx->transport.sin6.sin6_addr,
+			       sizeof(struct in6_addr));
+#endif
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
+	struct rxrpc_local *local,
+	const struct sockaddr_rxrpc *srx,
+	unsigned long hash_key)
+{
+	struct rxrpc_peer *peer;
+	struct rxrpc_net *rxnet = local->rxnet;
+
+	hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
+		if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
+		    refcount_read(&peer->ref) > 0)
+			return peer;
+	}
+
+	return NULL;
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
+					 const struct sockaddr_rxrpc *srx)
+{
+	struct rxrpc_peer *peer;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer)
+		_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	return peer;
+}
+
+/*
+ * assess the MTU size for the network interface through which this peer is
+ * reached
+ */
+void rxrpc_assess_MTU_size(struct rxrpc_local *local, struct rxrpc_peer *peer)
+{
+	struct net *net = local->net;
+	struct dst_entry *dst;
+	struct rtable *rt;
+	struct flowi fl;
+	struct flowi4 *fl4 = &fl.u.ip4;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	struct flowi6 *fl6 = &fl.u.ip6;
+#endif
+
+	peer->if_mtu = 1500;
+	if (peer->max_data < peer->if_mtu - peer->hdrsize) {
+		trace_rxrpc_pmtud_reduce(peer, 0, peer->if_mtu - peer->hdrsize,
+					 rxrpc_pmtud_reduce_route);
+		peer->max_data = peer->if_mtu - peer->hdrsize;
+	}
+
+	memset(&fl, 0, sizeof(fl));
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		rt = ip_route_output_ports(
+			net, fl4, NULL,
+			peer->srx.transport.sin.sin_addr.s_addr, 0,
+			htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
+		if (IS_ERR(rt)) {
+			_leave(" [route err %ld]", PTR_ERR(rt));
+			return;
+		}
+		dst = &rt->dst;
+		break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		fl6->flowi6_iif = LOOPBACK_IFINDEX;
+		fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
+		fl6->flowi6_proto = IPPROTO_UDP;
+		memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
+		       sizeof(struct in6_addr));
+		fl6->fl6_dport = htons(7001);
+		fl6->fl6_sport = htons(7000);
+		dst = ip6_route_output(net, NULL, fl6);
+		if (dst->error) {
+			_leave(" [route err %d]", dst->error);
+			return;
+		}
+		break;
+#endif
+
+	default:
+		BUG();
+	}
+
+	peer->if_mtu = dst_mtu(dst);
+	peer->hdrsize += dst->header_len + dst->trailer_len;
+	peer->tx_seg_max = dst->dev->gso_max_segs;
+	dst_release(dst);
+
+	peer->max_data		= umin(RXRPC_JUMBO(1), peer->if_mtu - peer->hdrsize);
+	peer->pmtud_good	= 500;
+	peer->pmtud_bad		= peer->if_mtu - peer->hdrsize + 1;
+	peer->pmtud_trial	= umin(peer->max_data, peer->pmtud_bad - 1);
+	peer->pmtud_pending	= true;
+
+	_leave(" [if_mtu %u]", peer->if_mtu);
+}
+
+/*
+ * Allocate a peer.
+ */
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp,
+				    enum rxrpc_peer_trace why)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = kzalloc_obj(struct rxrpc_peer, gfp);
+	if (peer) {
+		refcount_set(&peer->ref, 1);
+		peer->local = rxrpc_get_local(local, rxrpc_local_get_peer);
+		INIT_HLIST_HEAD(&peer->error_targets);
+		peer->service_conns = RB_ROOT;
+		seqlock_init(&peer->service_conn_lock);
+		spin_lock_init(&peer->lock);
+		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+		peer->recent_srtt_us = UINT_MAX;
+		peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
+		trace_rxrpc_peer(peer->debug_id, 1, why);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+/*
+ * Initialise peer record.
+ */
+static void rxrpc_init_peer(struct rxrpc_local *local, struct rxrpc_peer *peer,
+			    unsigned long hash_key)
+{
+	peer->hash_key = hash_key;
+
+
+	switch (peer->srx.transport.family) {
+	case AF_INET:
+		peer->hdrsize = sizeof(struct iphdr);
+		break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case AF_INET6:
+		peer->hdrsize = sizeof(struct ipv6hdr);
+		break;
+#endif
+	default:
+		BUG();
+	}
+
+	switch (peer->srx.transport_type) {
+	case SOCK_DGRAM:
+		peer->hdrsize += sizeof(struct udphdr);
+		break;
+	default:
+		BUG();
+	}
+
+	peer->hdrsize += sizeof(struct rxrpc_wire_header);
+	peer->max_data = peer->if_mtu - peer->hdrsize;
+}
+
+/*
+ * Set up a new peer.
+ */
+static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_local *local,
+					    struct sockaddr_rxrpc *srx,
+					    unsigned long hash_key,
+					    gfp_t gfp)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("");
+
+	peer = rxrpc_alloc_peer(local, gfp, rxrpc_peer_new_client);
+	if (peer) {
+		memcpy(&peer->srx, srx, sizeof(*srx));
+		rxrpc_init_peer(local, peer, hash_key);
+		rxrpc_assess_MTU_size(local, peer);
+	}
+
+	_leave(" = %p", peer);
+	return peer;
+}
+
+static void rxrpc_free_peer(struct rxrpc_peer *peer)
+{
+	trace_rxrpc_peer(peer->debug_id, 0, rxrpc_peer_free);
+	rxrpc_put_local(peer->local, rxrpc_local_put_peer);
+	kfree_rcu(peer, rcu);
+}
+
+/*
+ * Set up a new incoming peer.  There shouldn't be any other matching peers
+ * since we've already done a search in the list from the non-reentrant context
+ * (the data_ready handler) that is the only place we can add new peers.
+ * Called with interrupts disabled.
+ */
+void rxrpc_new_incoming_peer(struct rxrpc_local *local, struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key;
+
+	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
+	rxrpc_init_peer(local, peer, hash_key);
+
+	spin_lock(&rxnet->peer_hash_lock);
+	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
+	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
+	spin_unlock(&rxnet->peer_hash_lock);
+}
+
+/*
+ * obtain a remote transport endpoint for the specified address
+ */
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
+				     struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+	struct rxrpc_peer *peer, *candidate;
+	struct rxrpc_net *rxnet = local->rxnet;
+	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+	_enter("{%pISp}", &srx->transport);
+
+	/* search the peer list first */
+	rcu_read_lock();
+	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
+		peer = NULL;
+	rcu_read_unlock();
+
+	if (!peer) {
+		/* The peer is not yet present in hash - create a candidate
+		 * for a new record and then redo the search.
+		 */
+		candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
+		if (!candidate) {
+			_leave(" = NULL [nomem]");
+			return NULL;
+		}
+
+		spin_lock_bh(&rxnet->peer_hash_lock);
+
+		/* Need to check that we aren't racing with someone else */
+		peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+		if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
+			peer = NULL;
+		if (!peer) {
+			hash_add_rcu(rxnet->peer_hash,
+				     &candidate->hash_link, hash_key);
+			list_add_tail(&candidate->keepalive_link,
+				      &rxnet->peer_keepalive_new);
+		}
+
+		spin_unlock_bh(&rxnet->peer_hash_lock);
+
+		if (peer)
+			rxrpc_free_peer(candidate);
+		else
+			peer = candidate;
+	}
+
+	_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record.
+ */
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
+{
+	int r;
+
+	__refcount_inc(&peer->ref, &r);
+	trace_rxrpc_peer(peer->debug_id, r + 1, why);
+	return peer;
+}
+
+/*
+ * Get a ref on a peer record unless its usage has already reached 0.
+ */
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer,
+					enum rxrpc_peer_trace why)
+{
+	int r;
+
+	if (peer) {
+		if (__refcount_inc_not_zero(&peer->ref, &r))
+			trace_rxrpc_peer(peer->debug_id, r + 1, why);
+		else
+			peer = NULL;
+	}
+	return peer;
+}
+
+/*
+ * Discard a peer record.
+ */
+static void __rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	struct rxrpc_net *rxnet = peer->local->rxnet;
+
+	ASSERT(hlist_empty(&peer->error_targets));
+
+	spin_lock_bh(&rxnet->peer_hash_lock);
+	hash_del_rcu(&peer->hash_link);
+	list_del_init(&peer->keepalive_link);
+	spin_unlock_bh(&rxnet->peer_hash_lock);
+
+	rxrpc_free_peer(peer);
+}
+
+/*
+ * Drop a ref on a peer record.
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
+{
+	unsigned int debug_id;
+	bool dead;
+	int r;
+
+	if (peer) {
+		debug_id = peer->debug_id;
+		dead = __refcount_dec_and_test(&peer->ref, &r);
+		trace_rxrpc_peer(debug_id, r - 1, why);
+		if (dead)
+			__rxrpc_put_peer(peer);
+	}
+}
+
+/*
+ * Make sure all peer records have been discarded.
+ */
+void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
+{
+	struct rxrpc_peer *peer;
+	int i;
+
+	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
+		if (hlist_empty(&rxnet->peer_hash[i]))
+			continue;
+
+		hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
+			pr_err("Leaked peer %x {%u} %pISp\n",
+			       peer->debug_id,
+			       refcount_read(&peer->ref),
+			       &peer->srx.transport);
+		}
+	}
+}
+
+/**
+ * rxrpc_kernel_get_call_peer - Get the peer address of a call
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ *
+ * Get a record for the remote peer in a call.
+ *
+ * Return: The call's peer record.
+ */
+struct rxrpc_peer *rxrpc_kernel_get_call_peer(struct socket *sock, struct rxrpc_call *call)
+{
+	return rxrpc_get_peer(call->peer, rxrpc_peer_get_application);
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_call_peer);
+
+/**
+ * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
+ * @peer: The peer to query
+ *
+ * Get the call's peer smoothed RTT.
+ *
+ * Return: The RTT in uS or %UINT_MAX if we have no samples.
+ */
+unsigned int rxrpc_kernel_get_srtt(const struct rxrpc_peer *peer)
+{
+	return READ_ONCE(peer->recent_srtt_us);
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_srtt);
+
+/**
+ * rxrpc_kernel_remote_srx - Get the address of a peer
+ * @peer: The peer to query
+ *
+ * Get a pointer to the address from a peer record.  The caller is responsible
+ * for making sure that the address is not deallocated.  A fake address will be
+ * substituted if %peer in NULL.
+ *
+ * Return: The rxrpc address record or a fake record.
+ */
+const struct sockaddr_rxrpc *rxrpc_kernel_remote_srx(const struct rxrpc_peer *peer)
+{
+	return peer ? &peer->srx : &rxrpc_null_addr;
+}
+EXPORT_SYMBOL(rxrpc_kernel_remote_srx);
+
+/**
+ * rxrpc_kernel_remote_addr - Get the peer transport address of a call
+ * @peer: The peer to query
+ *
+ * Get a pointer to the transport address from a peer record.  The caller is
+ * responsible for making sure that the address is not deallocated.  A fake
+ * address will be substituted if %peer in NULL.
+ *
+ * Return: The transport address record or a fake record.
+ */
+const struct sockaddr *rxrpc_kernel_remote_addr(const struct rxrpc_peer *peer)
+{
+	return (const struct sockaddr *)
+		(peer ? &peer->srx.transport : &rxrpc_null_addr.transport);
+}
+EXPORT_SYMBOL(rxrpc_kernel_remote_addr);
+
+/**
+ * rxrpc_kernel_set_peer_data - Set app-specific data on a peer.
+ * @peer: The peer to alter
+ * @app_data: The data to set
+ *
+ * Set the app-specific data on a peer.  AF_RXRPC makes no effort to retain
+ * anything the data might refer to.
+ *
+ * Return: The previous app_data.
+ */
+unsigned long rxrpc_kernel_set_peer_data(struct rxrpc_peer *peer, unsigned long app_data)
+{
+	return xchg(&peer->app_data, app_data);
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_peer_data);
+
+/**
+ * rxrpc_kernel_get_peer_data - Get app-specific data from a peer.
+ * @peer: The peer to query
+ *
+ * Retrieve the app-specific data from a peer.
+ *
+ * Return: The peer's app data.
+ */
+unsigned long rxrpc_kernel_get_peer_data(const struct rxrpc_peer *peer)
+{
+	return peer->app_data;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer_data);
diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c
new file mode 100644
index 000000000..e9a27fa7b
--- /dev/null
+++ b/net/rxrpc/proc.c
@@ -0,0 +1,605 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* /proc/net/ support for AF_RXRPC
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+#define RXRPC_PROC_ADDRBUF_SIZE \
+	(sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + \
+	 sizeof(":12345"))
+
+static const char *const rxrpc_conn_states[RXRPC_CONN__NR_STATES] = {
+	[RXRPC_CONN_UNUSED]			= "Unused  ",
+	[RXRPC_CONN_CLIENT_UNSECURED]		= "ClUnsec ",
+	[RXRPC_CONN_CLIENT]			= "Client  ",
+	[RXRPC_CONN_SERVICE_PREALLOC]		= "SvPrealc",
+	[RXRPC_CONN_SERVICE_UNSECURED]		= "SvUnsec ",
+	[RXRPC_CONN_SERVICE_CHALLENGING]	= "SvChall ",
+	[RXRPC_CONN_SERVICE]			= "SvSecure",
+	[RXRPC_CONN_ABORTED]			= "Aborted ",
+};
+
+/*
+ * generate a list of extant and dead calls in /proc/net/rxrpc_calls
+ */
+static void *rxrpc_call_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	rcu_read_lock();
+	return seq_list_start_head_rcu(&rxnet->calls, *_pos);
+}
+
+static void *rxrpc_call_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	return seq_list_next_rcu(v, &rxnet->calls, pos);
+}
+
+static void rxrpc_call_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+static int rxrpc_call_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_call *call;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	enum rxrpc_call_state state;
+	rxrpc_seq_t tx_bottom;
+	char lbuff[RXRPC_PROC_ADDRBUF_SIZE], rbuff[RXRPC_PROC_ADDRBUF_SIZE];
+	long timeout = 0;
+
+	if (v == &rxnet->calls) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " SvID ConnID   CallID   End Use State    Abort   "
+			 " DebugId  TxSeq    TW RxSeq    RW RxSerial CW RxTimo\n");
+		return 0;
+	}
+
+	call = list_entry(v, struct rxrpc_call, link);
+
+	local = call->local;
+	if (local)
+		scnprintf(lbuff, sizeof(lbuff), "%pISpc", &local->srx.transport);
+	else
+		strcpy(lbuff, "no_local");
+
+	scnprintf(rbuff, sizeof(rbuff), "%pISpc", &call->dest_srx.transport);
+
+	state = rxrpc_call_state(call);
+	if (state != RXRPC_CALL_SERVER_PREALLOC)
+		timeout = ktime_ms_delta(READ_ONCE(call->expect_rx_by), ktime_get_real());
+
+	tx_bottom = READ_ONCE(call->tx_bottom);
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %4x %08x %08x %s %3u"
+		   " %-8.8s %08x %08x %08x %02x %08x %02x %08x %02x %06lx\n",
+		   lbuff,
+		   rbuff,
+		   call->dest_srx.srx_service,
+		   call->cid,
+		   call->call_id,
+		   rxrpc_is_service_call(call) ? "Svc" : "Clt",
+		   refcount_read(&call->ref),
+		   rxrpc_call_states[state],
+		   call->abort_code,
+		   call->debug_id,
+		   tx_bottom, READ_ONCE(call->tx_top) - tx_bottom,
+		   call->ackr_window, call->ackr_wtop - call->ackr_window,
+		   call->rx_serial,
+		   call->cong_cwnd,
+		   timeout);
+
+	return 0;
+}
+
+const struct seq_operations rxrpc_call_seq_ops = {
+	.start  = rxrpc_call_seq_start,
+	.next   = rxrpc_call_seq_next,
+	.stop   = rxrpc_call_seq_stop,
+	.show   = rxrpc_call_seq_show,
+};
+
+/*
+ * generate a list of extant virtual connections in /proc/net/rxrpc_conns
+ */
+static void *rxrpc_connection_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_lock(&rxnet->conn_lock);
+	return seq_list_start_head(&rxnet->conn_proc_list, *_pos);
+}
+
+static void *rxrpc_connection_seq_next(struct seq_file *seq, void *v,
+				       loff_t *pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	return seq_list_next(v, &rxnet->conn_proc_list, pos);
+}
+
+static void rxrpc_connection_seq_stop(struct seq_file *seq, void *v)
+	__releases(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_unlock(&rxnet->conn_lock);
+}
+
+static int rxrpc_connection_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	const char *state;
+	char lbuff[RXRPC_PROC_ADDRBUF_SIZE], rbuff[RXRPC_PROC_ADDRBUF_SIZE];
+
+	if (v == &rxnet->conn_proc_list) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " SvID ConnID   End Ref Act State    Key     "
+			 " Serial   ISerial  CallId0  CallId1  CallId2  CallId3\n"
+			 );
+		return 0;
+	}
+
+	conn = list_entry(v, struct rxrpc_connection, proc_link);
+	if (conn->state == RXRPC_CONN_SERVICE_PREALLOC) {
+		strcpy(lbuff, "no_local");
+		strcpy(rbuff, "no_connection");
+		goto print;
+	}
+
+	scnprintf(lbuff, sizeof(lbuff), "%pISpc", &conn->local->srx.transport);
+	scnprintf(rbuff, sizeof(rbuff), "%pISpc", &conn->peer->srx.transport);
+print:
+	state = rxrpc_is_conn_aborted(conn) ?
+		rxrpc_call_completions[conn->completion] :
+		rxrpc_conn_states[conn->state];
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %4x %08x %s %3u %3d"
+		   " %s %08x %08x %08x %08x %08x %08x %08x\n",
+		   lbuff,
+		   rbuff,
+		   conn->service_id,
+		   conn->proto.cid,
+		   rxrpc_conn_is_service(conn) ? "Svc" : "Clt",
+		   refcount_read(&conn->ref),
+		   atomic_read(&conn->active),
+		   state,
+		   key_serial(conn->key),
+		   conn->tx_serial,
+		   conn->hi_serial,
+		   conn->channels[0].call_id,
+		   conn->channels[1].call_id,
+		   conn->channels[2].call_id,
+		   conn->channels[3].call_id);
+
+	return 0;
+}
+
+const struct seq_operations rxrpc_connection_seq_ops = {
+	.start  = rxrpc_connection_seq_start,
+	.next   = rxrpc_connection_seq_next,
+	.stop   = rxrpc_connection_seq_stop,
+	.show   = rxrpc_connection_seq_show,
+};
+
+/*
+ * generate a list of extant virtual bundles in /proc/net/rxrpc/bundles
+ */
+static void *rxrpc_bundle_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_lock(&rxnet->conn_lock);
+	return seq_list_start_head(&rxnet->bundle_proc_list, *_pos);
+}
+
+static void *rxrpc_bundle_seq_next(struct seq_file *seq, void *v,
+				       loff_t *pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	return seq_list_next(v, &rxnet->bundle_proc_list, pos);
+}
+
+static void rxrpc_bundle_seq_stop(struct seq_file *seq, void *v)
+	__releases(rxnet->conn_lock)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	read_unlock(&rxnet->conn_lock);
+}
+
+static int rxrpc_bundle_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_bundle *bundle;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	char lbuff[RXRPC_PROC_ADDRBUF_SIZE], rbuff[RXRPC_PROC_ADDRBUF_SIZE];
+
+	if (v == &rxnet->bundle_proc_list) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Remote                                         "
+			 " SvID Ref Act Flg Key      |"
+			 " Bundle   Conn_0   Conn_1   Conn_2   Conn_3\n"
+			 );
+		return 0;
+	}
+
+	bundle = list_entry(v, struct rxrpc_bundle, proc_link);
+
+	scnprintf(lbuff, sizeof(lbuff), "%pISpc", &bundle->local->srx.transport);
+	scnprintf(rbuff, sizeof(rbuff), "%pISpc", &bundle->peer->srx.transport);
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %4x %3u %3d"
+		   " %c%c%c %08x | %08x %08x %08x %08x %08x\n",
+		   lbuff,
+		   rbuff,
+		   bundle->service_id,
+		   refcount_read(&bundle->ref),
+		   atomic_read(&bundle->active),
+		   bundle->try_upgrade ? 'U' : '-',
+		   bundle->exclusive ? 'e' : '-',
+		   bundle->upgrade ? 'u' : '-',
+		   key_serial(bundle->key),
+		   bundle->debug_id,
+		   bundle->conn_ids[0],
+		   bundle->conn_ids[1],
+		   bundle->conn_ids[2],
+		   bundle->conn_ids[3]);
+
+	return 0;
+}
+
+const struct seq_operations rxrpc_bundle_seq_ops = {
+	.start  = rxrpc_bundle_seq_start,
+	.next   = rxrpc_bundle_seq_next,
+	.stop   = rxrpc_bundle_seq_stop,
+	.show   = rxrpc_bundle_seq_show,
+};
+
+/*
+ * generate a list of extant virtual peers in /proc/net/rxrpc/peers
+ */
+static int rxrpc_peer_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_peer *peer;
+	time64_t now;
+	char lbuff[RXRPC_PROC_ADDRBUF_SIZE], rbuff[RXRPC_PROC_ADDRBUF_SIZE];
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+			 "Proto Local                                           Remote                                          Use SST   Maxd LastUse      RTT      RTO\n"
+			 );
+		return 0;
+	}
+
+	peer = list_entry(v, struct rxrpc_peer, hash_link);
+
+	scnprintf(lbuff, sizeof(lbuff), "%pISpc", &peer->local->srx.transport);
+
+	scnprintf(rbuff, sizeof(rbuff), "%pISpc", &peer->srx.transport);
+
+	now = ktime_get_seconds();
+	seq_printf(seq,
+		   "UDP   %-47.47s %-47.47s %3u %4u %5u %6ds %8d %8d\n",
+		   lbuff,
+		   rbuff,
+		   refcount_read(&peer->ref),
+		   peer->cong_ssthresh,
+		   peer->max_data,
+		   (s32)now - (s32)READ_ONCE(peer->last_tx_at),
+		   READ_ONCE(peer->recent_srtt_us),
+		   READ_ONCE(peer->recent_rto_us));
+
+	return 0;
+}
+
+static void *rxrpc_peer_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int bucket, n;
+	unsigned int shift = 32 - HASH_BITS(rxnet->peer_hash);
+	void *p;
+
+	rcu_read_lock();
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	n = *_pos & ((1U << shift) - 1);
+	bucket = *_pos >> shift;
+	for (;;) {
+		if (bucket >= HASH_SIZE(rxnet->peer_hash)) {
+			*_pos = UINT_MAX;
+			return NULL;
+		}
+		if (n == 0) {
+			if (bucket == 0)
+				return SEQ_START_TOKEN;
+			*_pos += 1;
+			n++;
+		}
+
+		p = seq_hlist_start_rcu(&rxnet->peer_hash[bucket], n - 1);
+		if (p)
+			return p;
+		bucket++;
+		n = 1;
+		*_pos = (bucket << shift) | n;
+	}
+}
+
+static void *rxrpc_peer_seq_next(struct seq_file *seq, void *v, loff_t *_pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int bucket, n;
+	unsigned int shift = 32 - HASH_BITS(rxnet->peer_hash);
+	void *p;
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	bucket = *_pos >> shift;
+
+	p = seq_hlist_next_rcu(v, &rxnet->peer_hash[bucket], _pos);
+	if (p)
+		return p;
+
+	for (;;) {
+		bucket++;
+		n = 1;
+		*_pos = (bucket << shift) | n;
+
+		if (bucket >= HASH_SIZE(rxnet->peer_hash)) {
+			*_pos = UINT_MAX;
+			return NULL;
+		}
+		if (n == 0) {
+			*_pos += 1;
+			n++;
+		}
+
+		p = seq_hlist_start_rcu(&rxnet->peer_hash[bucket], n - 1);
+		if (p)
+			return p;
+	}
+}
+
+static void rxrpc_peer_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+
+const struct seq_operations rxrpc_peer_seq_ops = {
+	.start  = rxrpc_peer_seq_start,
+	.next   = rxrpc_peer_seq_next,
+	.stop   = rxrpc_peer_seq_stop,
+	.show   = rxrpc_peer_seq_show,
+};
+
+/*
+ * Generate a list of extant virtual local endpoints in /proc/net/rxrpc/locals
+ */
+static int rxrpc_local_seq_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_local *local;
+	char lbuff[RXRPC_PROC_ADDRBUF_SIZE];
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+			 "Proto Local                                          "
+			 " Use Act RxQ\n");
+		return 0;
+	}
+
+	local = hlist_entry(v, struct rxrpc_local, link);
+
+	scnprintf(lbuff, sizeof(lbuff), "%pISpc", &local->srx.transport);
+
+	seq_printf(seq,
+		   "UDP   %-47.47s %3u %3u %3u\n",
+		   lbuff,
+		   refcount_read(&local->ref),
+		   atomic_read(&local->active_users),
+		   local->rx_queue.qlen);
+
+	return 0;
+}
+
+static void *rxrpc_local_seq_start(struct seq_file *seq, loff_t *_pos)
+	__acquires(rcu)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+	unsigned int n;
+
+	rcu_read_lock();
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	n = *_pos;
+	if (n == 0)
+		return SEQ_START_TOKEN;
+
+	return seq_hlist_start_rcu(&rxnet->local_endpoints, n - 1);
+}
+
+static void *rxrpc_local_seq_next(struct seq_file *seq, void *v, loff_t *_pos)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_net(seq));
+
+	if (*_pos >= UINT_MAX)
+		return NULL;
+
+	return seq_hlist_next_rcu(v, &rxnet->local_endpoints, _pos);
+}
+
+static void rxrpc_local_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+const struct seq_operations rxrpc_local_seq_ops = {
+	.start  = rxrpc_local_seq_start,
+	.next   = rxrpc_local_seq_next,
+	.stop   = rxrpc_local_seq_stop,
+	.show   = rxrpc_local_seq_show,
+};
+
+/*
+ * Display stats in /proc/net/rxrpc/stats
+ */
+int rxrpc_stats_show(struct seq_file *seq, void *v)
+{
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(seq));
+
+	seq_printf(seq,
+		   "Data     : send=%u sendf=%u fail=%u emsz=%u\n",
+		   atomic_read(&rxnet->stat_tx_data_send),
+		   atomic_read(&rxnet->stat_tx_data_send_frag),
+		   atomic_read(&rxnet->stat_tx_data_send_fail),
+		   atomic_read(&rxnet->stat_tx_data_send_msgsize));
+	seq_printf(seq,
+		   "Data-Tx  : nr=%u retrans=%u uf=%u cwr=%u\n",
+		   atomic_read(&rxnet->stat_tx_data),
+		   atomic_read(&rxnet->stat_tx_data_retrans),
+		   atomic_read(&rxnet->stat_tx_data_underflow),
+		   atomic_read(&rxnet->stat_tx_data_cwnd_reset));
+	seq_printf(seq,
+		   "Data-Rx  : nr=%u reqack=%u jumbo=%u\n",
+		   atomic_read(&rxnet->stat_rx_data),
+		   atomic_read(&rxnet->stat_rx_data_reqack),
+		   atomic_read(&rxnet->stat_rx_data_jumbo));
+	seq_printf(seq,
+		   "Ack      : fill=%u send=%u skip=%u\n",
+		   atomic_read(&rxnet->stat_tx_ack_fill),
+		   atomic_read(&rxnet->stat_tx_ack_send),
+		   atomic_read(&rxnet->stat_tx_ack_skip));
+	seq_printf(seq,
+		   "Ack-Tx   : req=%u dup=%u oos=%u exw=%u nos=%u png=%u prs=%u dly=%u idl=%u\n",
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_REQUESTED]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_DUPLICATE]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_OUT_OF_SEQUENCE]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_EXCEEDS_WINDOW]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_NOSPACE]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_PING]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_PING_RESPONSE]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_DELAY]),
+		   atomic_read(&rxnet->stat_tx_acks[RXRPC_ACK_IDLE]));
+	seq_printf(seq,
+		   "Ack-Rx   : req=%u dup=%u oos=%u exw=%u nos=%u png=%u prs=%u dly=%u idl=%u z=%u\n",
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_REQUESTED]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_DUPLICATE]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_OUT_OF_SEQUENCE]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_EXCEEDS_WINDOW]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_NOSPACE]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_PING]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_PING_RESPONSE]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_DELAY]),
+		   atomic_read(&rxnet->stat_rx_acks[RXRPC_ACK_IDLE]),
+		   atomic_read(&rxnet->stat_rx_acks[0]));
+	seq_printf(seq,
+		   "Why-Req-A: acklost=%u mrtt=%u ortt=%u stall=%u jwin=%u\n",
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_ack_lost]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_more_rtt]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_old_rtt]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_app_stall]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_jumbo_win]));
+	seq_printf(seq,
+		   "Why-Req-A: nolast=%u retx=%u slows=%u smtxw=%u\n",
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_no_srv_last]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_retrans]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_slow_start]),
+		   atomic_read(&rxnet->stat_why_req_ack[rxrpc_reqack_small_txwin]));
+	seq_printf(seq,
+		   "Jumbo-Tx : %u,%u,%u,%u,%u,%u,%u,%u,%u,%u\n",
+		   atomic_read(&rxnet->stat_tx_jumbo[0]),
+		   atomic_read(&rxnet->stat_tx_jumbo[1]),
+		   atomic_read(&rxnet->stat_tx_jumbo[2]),
+		   atomic_read(&rxnet->stat_tx_jumbo[3]),
+		   atomic_read(&rxnet->stat_tx_jumbo[4]),
+		   atomic_read(&rxnet->stat_tx_jumbo[5]),
+		   atomic_read(&rxnet->stat_tx_jumbo[6]),
+		   atomic_read(&rxnet->stat_tx_jumbo[7]),
+		   atomic_read(&rxnet->stat_tx_jumbo[8]),
+		   atomic_read(&rxnet->stat_tx_jumbo[9]));
+	seq_printf(seq,
+		   "Jumbo-Rx : %u,%u,%u,%u,%u,%u,%u,%u,%u,%u\n",
+		   atomic_read(&rxnet->stat_rx_jumbo[0]),
+		   atomic_read(&rxnet->stat_rx_jumbo[1]),
+		   atomic_read(&rxnet->stat_rx_jumbo[2]),
+		   atomic_read(&rxnet->stat_rx_jumbo[3]),
+		   atomic_read(&rxnet->stat_rx_jumbo[4]),
+		   atomic_read(&rxnet->stat_rx_jumbo[5]),
+		   atomic_read(&rxnet->stat_rx_jumbo[6]),
+		   atomic_read(&rxnet->stat_rx_jumbo[7]),
+		   atomic_read(&rxnet->stat_rx_jumbo[8]),
+		   atomic_read(&rxnet->stat_rx_jumbo[9]));
+	seq_printf(seq,
+		   "Buffers  : txb=%u rxb=%u\n",
+		   atomic_read(&rxrpc_nr_txbuf),
+		   atomic_read(&rxrpc_n_rx_skbs));
+	seq_printf(seq,
+		   "IO-thread: loops=%u\n",
+		   atomic_read(&rxnet->stat_io_loop));
+	return 0;
+}
+
+/*
+ * Clear stats if /proc/net/rxrpc/stats is written to.
+ */
+int rxrpc_stats_clear(struct file *file, char *buf, size_t size)
+{
+	struct seq_file *m = file->private_data;
+	struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(m));
+
+	if (size > 1 || (size == 1 && buf[0] != '\n'))
+		return -EINVAL;
+
+	atomic_set(&rxnet->stat_tx_data, 0);
+	atomic_set(&rxnet->stat_tx_data_retrans, 0);
+	atomic_set(&rxnet->stat_tx_data_underflow, 0);
+	atomic_set(&rxnet->stat_tx_data_cwnd_reset, 0);
+	atomic_set(&rxnet->stat_tx_data_send, 0);
+	atomic_set(&rxnet->stat_tx_data_send_frag, 0);
+	atomic_set(&rxnet->stat_tx_data_send_fail, 0);
+	atomic_set(&rxnet->stat_rx_data, 0);
+	atomic_set(&rxnet->stat_rx_data_reqack, 0);
+	atomic_set(&rxnet->stat_rx_data_jumbo, 0);
+
+	atomic_set(&rxnet->stat_tx_ack_fill, 0);
+	atomic_set(&rxnet->stat_tx_ack_send, 0);
+	atomic_set(&rxnet->stat_tx_ack_skip, 0);
+	memset(&rxnet->stat_tx_acks, 0, sizeof(rxnet->stat_tx_acks));
+	memset(&rxnet->stat_rx_acks, 0, sizeof(rxnet->stat_rx_acks));
+	memset(&rxnet->stat_tx_jumbo, 0, sizeof(rxnet->stat_tx_jumbo));
+	memset(&rxnet->stat_rx_jumbo, 0, sizeof(rxnet->stat_rx_jumbo));
+
+	memset(&rxnet->stat_why_req_ack, 0, sizeof(rxnet->stat_why_req_ack));
+
+	atomic_set(&rxnet->stat_io_loop, 0);
+	return size;
+}
diff --git a/net/rxrpc/protocol.h b/net/rxrpc/protocol.h
new file mode 100644
index 000000000..f8bfec12b
--- /dev/null
+++ b/net/rxrpc/protocol.h
@@ -0,0 +1,204 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* packet.h: Rx packet layout and definitions
+ *
+ * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _LINUX_RXRPC_PACKET_H
+#define _LINUX_RXRPC_PACKET_H
+
+typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
+typedef u32	rxrpc_serial_t;	/* Rx message serial number */
+typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
+typedef __be32	rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx packet header
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_wire_header {
+	__be32		epoch;		/* client boot timestamp */
+#define RXRPC_RANDOM_EPOCH	0x80000000	/* Random if set, date-based if not */
+
+	__be32		cid;		/* connection and channel ID */
+#define RXRPC_MAXCALLS		4			/* max active calls per conn */
+#define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
+#define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
+#define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
+#define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */
+
+	__be32		callNumber;	/* call ID (0 for connection-level packets) */
+	__be32		seq;		/* sequence number of pkt in call stream */
+	__be32		serial;		/* serial number of pkt sent to network */
+
+	uint8_t		type;		/* packet type */
+#define RXRPC_PACKET_TYPE_DATA		1	/* data */
+#define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
+#define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
+#define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
+#define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
+#define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
+#define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
+#define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
+#define RXRPC_PACKET_TYPE_PARAMS	9	/* Parameter negotiation (unspec'd, ignore) */
+#define RXRPC_PACKET_TYPE_10		10	/* Ignored */
+#define RXRPC_PACKET_TYPE_11		11	/* Ignored */
+#define RXRPC_PACKET_TYPE_VERSION	13	/* version string request */
+
+	uint8_t		flags;		/* packet flags */
+#define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
+#define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
+#define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
+#define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
+#define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
+#define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
+
+	uint8_t		userStatus;	/* app-layer defined status */
+#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01	/* AuriStor service upgrade request */
+
+	uint8_t		securityIndex;	/* security protocol ID */
+	union {
+		__be16	_rsvd;		/* reserved */
+		__be16	cksum;		/* kerberos security checksum */
+	};
+	__be16		serviceId;	/* service ID */
+
+} __packed;
+
+/*****************************************************************************/
+/*
+ * jumbo packet secondary header
+ * - can be mapped to read header by:
+ *   - new_serial = serial + 1
+ *   - new_seq = seq + 1
+ *   - new_flags = j_flags
+ *   - new__rsvd = j__rsvd
+ *   - duplicating all other fields
+ */
+struct rxrpc_jumbo_header {
+	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
+	uint8_t		pad;
+	union {
+		__be16	_rsvd;		/* reserved */
+		__be16	cksum;		/* kerberos security checksum */
+	};
+} __packed;
+
+#define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
+#define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
+
+/*
+ * The maximum number of subpackets that can possibly fit in a UDP packet is:
+ *
+ *	(max_UDP - wirehdr + jumbohdr) / (jumbohdr + 1412)
+ *	= ((65535 - 28 + 4) / 1416)
+ *	= 45 non-terminal packets and 1 terminal packet.
+ */
+#define RXRPC_MAX_NR_JUMBO	46
+
+/* Size of a jumbo packet with N subpackets, excluding UDP+IP */
+#define RXRPC_JUMBO(N) ((int)sizeof(struct rxrpc_wire_header) + \
+			RXRPC_JUMBO_DATALEN +				\
+			((N) - 1) * RXRPC_JUMBO_SUBPKTLEN)
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx ACK packet data payload
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_ackpacket {
+	__be16		bufferSpace;	/* number of packet buffers available */
+	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
+					 * received */
+	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
+	__be32		previousPacket;	/* sequence no of previous packet received */
+	__be32		serial;		/* serial no of packet that prompted this ACK */
+
+	uint8_t		reason;		/* reason for ACK */
+#define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
+#define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
+#define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
+#define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
+#define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
+#define RXRPC_ACK_PING			6	/* keep alive ACK */
+#define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
+#define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
+#define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
+#define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */
+
+	uint8_t		nAcks;		/* number of ACKs */
+#define RXRPC_MAXACKS	255
+
+	uint8_t		acks[];		/* list of ACK/NAKs */
+#define RXRPC_ACK_TYPE_NACK		0
+#define RXRPC_ACK_TYPE_ACK		1
+
+} __packed;
+
+/*
+ * ACK packets can have a further piece of information tagged on the end
+ */
+struct rxrpc_acktrailer {
+	__be32		maxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
+	__be32		ifMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
+	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
+	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
+};
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 challenge packet
+ */
+struct rxkad_challenge {
+	__be32		version;	/* version of this challenge type */
+	__be32		nonce;		/* encrypted random number */
+	__be32		min_level;	/* minimum security level */
+	__be32		__padding;	/* padding to 8-byte boundary */
+} __packed;
+
+/*****************************************************************************/
+/*
+ * Kerberos security type-2 response packet
+ */
+struct rxkad_response {
+	__be32		version;	/* version of this response type */
+	__be32		__pad;
+
+	/* encrypted bit of the response */
+	struct {
+		__be32		epoch;		/* current epoch */
+		__be32		cid;		/* parent connection ID */
+		__be32		checksum;	/* checksum */
+		__be32		securityIndex;	/* security type */
+		__be32		call_id[4];	/* encrypted call IDs */
+		__be32		inc_nonce;	/* challenge nonce + 1 */
+		__be32		level;		/* desired level */
+	} encrypted;
+
+	__be32		kvno;		/* Kerberos key version number */
+	__be32		ticket_len;	/* Kerberos ticket length  */
+} __packed;
+
+/*
+ * GSSAPI security type-4 and type-6 data header.
+ */
+struct rxgk_header {
+	__be32	epoch;
+	__be32	cid;
+	__be32	call_number;
+	__be32	seq;
+	__be32	sec_index;
+	__be32	data_len;
+} __packed;
+
+/*
+ * GSSAPI security type-4 and type-6 response packet header.
+ */
+struct rxgk_response {
+	__be64	start_time;
+	__be32	token_len;
+} __packed;
+
+#endif /* _LINUX_RXRPC_PACKET_H */
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
new file mode 100644
index 000000000..efcba4b2e
--- /dev/null
+++ b/net/rxrpc/recvmsg.c
@@ -0,0 +1,710 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC recvmsg() implementation
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Post a call for attention by the socket or kernel service.  Further
+ * notifications are suppressed by putting recvmsg_link on a dummy queue.
+ */
+void rxrpc_notify_socket(struct rxrpc_call *call)
+{
+	struct rxrpc_sock *rx;
+	struct sock *sk;
+
+	_enter("%d", call->debug_id);
+
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_notify_released);
+		return;
+	}
+
+	rcu_read_lock();
+
+	rx = rcu_dereference(call->socket);
+	sk = &rx->sk;
+	if (rx && sk->sk_state < RXRPC_CLOSE) {
+		if (call->notify_rx) {
+			spin_lock_irq(&call->notify_lock);
+			call->notify_rx(sk, call, call->user_call_ID);
+			spin_unlock_irq(&call->notify_lock);
+		} else {
+			spin_lock_irq(&rx->recvmsg_lock);
+			if (list_empty(&call->recvmsg_link)) {
+				rxrpc_get_call(call, rxrpc_call_get_notify_socket);
+				list_add_tail(&call->recvmsg_link, &rx->recvmsg_q);
+			}
+			spin_unlock_irq(&rx->recvmsg_lock);
+
+			if (!sock_flag(sk, SOCK_DEAD)) {
+				_debug("call %ps", sk->sk_data_ready);
+				sk->sk_data_ready(sk);
+			}
+		}
+	}
+
+	rcu_read_unlock();
+	_leave("");
+}
+
+/*
+ * Pass a call terminating message to userspace.
+ */
+static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg)
+{
+	u32 tmp = 0;
+	int ret;
+
+	switch (call->completion) {
+	case RXRPC_CALL_SUCCEEDED:
+		ret = 0;
+		if (rxrpc_is_service_call(call))
+			ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp);
+		break;
+	case RXRPC_CALL_REMOTELY_ABORTED:
+		tmp = call->abort_code;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
+		break;
+	case RXRPC_CALL_LOCALLY_ABORTED:
+		tmp = call->abort_code;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
+		break;
+	case RXRPC_CALL_NETWORK_ERROR:
+		tmp = -call->error;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp);
+		break;
+	case RXRPC_CALL_LOCAL_ERROR:
+		tmp = -call->error;
+		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp);
+		break;
+	default:
+		pr_err("Invalid terminal call state %u\n", call->completion);
+		BUG();
+		break;
+	}
+
+	trace_rxrpc_recvdata(call, rxrpc_recvmsg_terminal,
+			     call->ackr_window - 1,
+			     call->rx_pkt_offset, call->rx_pkt_len, ret);
+	return ret;
+}
+
+/*
+ * Discard a packet we've used up and advance the Rx window by one.
+ */
+static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	rxrpc_serial_t serial;
+	rxrpc_seq_t old_consumed = call->rx_consumed, tseq;
+	bool last;
+	int acked;
+
+	_enter("%d", call->debug_id);
+
+	skb = skb_dequeue(&call->recvmsg_queue);
+	rxrpc_see_skb(skb, rxrpc_skb_see_rotate);
+
+	sp = rxrpc_skb(skb);
+	tseq   = sp->hdr.seq;
+	serial = sp->hdr.serial;
+	last   = sp->hdr.flags & RXRPC_LAST_PACKET;
+
+	/* Barrier against rxrpc_input_data(). */
+	if (after(tseq, call->rx_consumed))
+		smp_store_release(&call->rx_consumed, tseq);
+
+	rxrpc_free_skb(skb, rxrpc_skb_put_rotate);
+
+	trace_rxrpc_receive(call, last ? rxrpc_receive_rotate_last : rxrpc_receive_rotate,
+			    serial, call->rx_consumed);
+
+	if (last)
+		set_bit(RXRPC_CALL_RECVMSG_READ_ALL, &call->flags);
+
+	/* Check to see if there's an ACK that needs sending. */
+	acked = atomic_add_return(call->rx_consumed - old_consumed,
+				  &call->ackr_nr_consumed);
+	if (acked > 8 &&
+	    !test_and_set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags))
+		rxrpc_poke_call(call, rxrpc_call_poke_idle);
+}
+
+/*
+ * Decrypt and verify a DATA packet.  The content of the packet is pulled out
+ * into a flat buffer rather than decrypting in place in the skbuff.  This also
+ * has the advantage of aligning the buffer correctly for the crypto routines.
+ *
+ * We keep track of the sequence number of the packet currently decrypted into
+ * the buffer in ->rx_dec_seq.  If MSG_PEEK is used and steps onto a new
+ * packet, subsequent recvmsg() calls will have to go back and re-decrypt the
+ * current packet.
+ */
+static int rxrpc_verify_data(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	int ret;
+
+	if (sp->len > call->rx_dec_bsize || !call->rx_dec_buffer) {
+		/* Make sure we can hold a 1412-byte jumbo subpacket and make
+		 * sure that the buffer size is aligned to a crypto blocksize.
+		 */
+		size_t size = clamp(round_up(sp->len, 32), 2048, 65535);
+		void *buffer = krealloc(call->rx_dec_buffer, size, GFP_NOFS);
+
+		if (!buffer)
+			return -ENOMEM;
+		call->rx_dec_buffer = buffer;
+		call->rx_dec_bsize = size;
+	}
+
+	ret = -EFAULT;
+	if (skb_copy_bits(skb, sp->offset, call->rx_dec_buffer, sp->len) < 0)
+		goto err;
+
+	call->rx_dec_offset = 0;
+	call->rx_dec_len = sp->len;
+	call->rx_dec_seq = sp->hdr.seq;
+	ret = call->security->verify_packet(call, skb);
+	if (ret < 0)
+		goto err;
+	return 0;
+
+err:
+	kfree(call->rx_dec_buffer);
+	call->rx_dec_buffer = NULL;
+	call->rx_dec_bsize = 0;
+	call->rx_dec_offset = 0;
+	call->rx_dec_len = 0;
+	return ret;
+}
+
+/*
+ * Transcribe a call's user ID to a control message.
+ */
+static int rxrpc_recvmsg_user_id(struct rxrpc_call *call, struct msghdr *msg,
+				 int flags)
+{
+	if (!test_bit(RXRPC_CALL_HAS_USERID, &call->flags))
+		return 0;
+
+	if (flags & MSG_CMSG_COMPAT) {
+		unsigned int id32 = call->user_call_ID;
+
+		return put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
+				sizeof(unsigned int), &id32);
+	} else {
+		unsigned long idl = call->user_call_ID;
+
+		return put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
+				sizeof(unsigned long), &idl);
+	}
+}
+
+/*
+ * Deal with a CHALLENGE packet.
+ */
+static int rxrpc_recvmsg_challenge(struct socket *sock, struct msghdr *msg,
+				   struct sk_buff *challenge, unsigned int flags)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(challenge);
+	struct rxrpc_connection *conn = sp->chall.conn;
+
+	return conn->security->challenge_to_recvmsg(conn, challenge, msg);
+}
+
+/*
+ * Process OOB packets.  Called with the socket locked.
+ */
+static int rxrpc_recvmsg_oob(struct socket *sock, struct msghdr *msg,
+			     unsigned int flags)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct sk_buff *skb;
+	bool need_response = false;
+	int ret;
+
+	skb = skb_peek(&rx->recvmsg_oobq);
+	if (!skb)
+		return -EAGAIN;
+	rxrpc_see_skb(skb, rxrpc_skb_see_recvmsg);
+
+	ret = put_cmsg(msg, SOL_RXRPC, RXRPC_OOB_ID, sizeof(u64),
+		       &skb->skb_mstamp_ns);
+	if (ret < 0)
+		return ret;
+
+	switch ((enum rxrpc_oob_type)skb->mark) {
+	case RXRPC_OOB_CHALLENGE:
+		need_response = true;
+		ret = rxrpc_recvmsg_challenge(sock, msg, skb, flags);
+		break;
+	default:
+		WARN_ONCE(1, "recvmsg() can't process unknown OOB type %u\n",
+			  skb->mark);
+		ret = -EIO;
+		break;
+	}
+
+	if (!(flags & MSG_PEEK)) {
+		skb_unlink(skb, &rx->recvmsg_oobq);
+		if (need_response)
+			rxrpc_add_pending_oob(rx, skb);
+		else
+			rxrpc_free_skb(skb, rxrpc_skb_put_oob);
+	}
+	return ret;
+}
+
+/*
+ * Deliver messages to a call.  This keeps processing packets until the buffer
+ * is filled and we find either more DATA (returns 0) or the end of the DATA
+ * (returns 1).  If more packets are required, it returns -EAGAIN and if the
+ * call has failed it returns -EIO.
+ */
+static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
+			      struct msghdr *msg, struct iov_iter *iter,
+			      size_t len, int flags, size_t *_offset)
+{
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct sk_buff *skb;
+	rxrpc_seq_t seq = 0;
+	size_t remain;
+	unsigned int rx_pkt_offset, rx_pkt_len;
+	int copy, ret = -EAGAIN, ret2;
+
+	rx_pkt_offset = call->rx_pkt_offset;
+	rx_pkt_len = call->rx_pkt_len;
+
+	if (rxrpc_call_has_failed(call)) {
+		seq = call->ackr_window - 1;
+		ret = -EIO;
+		goto done;
+	}
+
+	if (test_bit(RXRPC_CALL_RECVMSG_READ_ALL, &call->flags)) {
+		seq = call->ackr_window - 1;
+		ret = 1;
+		goto done;
+	}
+
+	/* No one else can be removing stuff from the queue, so we shouldn't
+	 * need the Rx lock to walk it.
+	 */
+	skb = skb_peek(&call->recvmsg_queue);
+	while (skb) {
+		rxrpc_see_skb(skb, rxrpc_skb_see_recvmsg);
+		sp = rxrpc_skb(skb);
+		seq = sp->hdr.seq;
+
+		if (!(flags & MSG_PEEK))
+			trace_rxrpc_receive(call, rxrpc_receive_front,
+					    sp->hdr.serial, seq);
+
+		if (msg)
+			sock_recv_timestamp(msg, sock->sk, skb);
+
+		if (call->rx_dec_seq != sp->hdr.seq ||
+		    !call->rx_dec_buffer) {
+			ret2 = rxrpc_verify_data(call, skb);
+			trace_rxrpc_recvdata(call, rxrpc_recvmsg_next, seq,
+					     call->rx_dec_offset,
+					     call->rx_dec_len, ret2);
+			if (ret2 < 0) {
+				ret = ret2;
+				goto out;
+			}
+		}
+
+		if (rx_pkt_offset == USHRT_MAX) {
+			rx_pkt_offset = call->rx_dec_offset;
+			rx_pkt_len = call->rx_dec_len;
+		} else {
+			trace_rxrpc_recvdata(call, rxrpc_recvmsg_cont, seq,
+					     rx_pkt_offset, rx_pkt_len, 0);
+		}
+
+		/* We have to handle short, empty and used-up DATA packets. */
+		remain = len - *_offset;
+		copy = rx_pkt_len;
+		if (copy > remain)
+			copy = remain;
+		if (copy > 0) {
+			ret2 = copy_to_iter(call->rx_dec_buffer + rx_pkt_offset,
+					    copy, iter);
+			if (ret2 != copy) {
+				ret = -EFAULT;
+				goto out;
+			}
+
+			/* handle piecemeal consumption of data packets */
+			rx_pkt_offset += copy;
+			rx_pkt_len -= copy;
+			*_offset += copy;
+		}
+
+		if (rx_pkt_len > 0) {
+			trace_rxrpc_recvdata(call, rxrpc_recvmsg_full, seq,
+					     rx_pkt_offset, rx_pkt_len, 0);
+			ASSERTCMP(*_offset, ==, len);
+			ret = 0;
+			break;
+		}
+
+		/* The whole packet has been transferred. */
+		if (sp->hdr.flags & RXRPC_LAST_PACKET)
+			ret = 1;
+		rx_pkt_offset = USHRT_MAX;
+		rx_pkt_len = 0;
+
+		skb = skb_peek_next(skb, &call->recvmsg_queue);
+
+		if (!(flags & MSG_PEEK))
+			rxrpc_rotate_rx_window(call);
+
+		if (!rx->app_ops &&
+		    !skb_queue_empty_lockless(&rx->recvmsg_oobq)) {
+			trace_rxrpc_recvdata(call, rxrpc_recvmsg_oobq, seq,
+					     rx_pkt_offset, rx_pkt_len, ret);
+			break;
+		}
+	}
+
+out:
+	if (!(flags & MSG_PEEK)) {
+		call->rx_pkt_offset = rx_pkt_offset;
+		call->rx_pkt_len = rx_pkt_len;
+	}
+
+done:
+	trace_rxrpc_recvdata(call, rxrpc_recvmsg_data_return, seq,
+			     rx_pkt_offset, rx_pkt_len, ret);
+	if (ret == -EAGAIN)
+		set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
+	return ret;
+}
+
+/*
+ * Receive a message from an RxRPC socket
+ * - we need to be careful about two or more threads calling recvmsg
+ *   simultaneously
+ */
+int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+		  int flags)
+{
+	struct rxrpc_call *call;
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct list_head *l;
+	unsigned int call_debug_id = 0;
+	size_t copied = 0;
+	long timeo;
+	int ret;
+
+	DEFINE_WAIT(wait);
+
+	trace_rxrpc_recvmsg(0, rxrpc_recvmsg_enter, 0);
+
+	if (flags & (MSG_OOB | MSG_TRUNC))
+		return -EOPNOTSUPP;
+
+	timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
+
+try_again:
+	lock_sock(&rx->sk);
+
+	/* Return immediately if a client socket has no outstanding calls */
+	if (RB_EMPTY_ROOT(&rx->calls) &&
+	    list_empty(&rx->recvmsg_q) &&
+	    skb_queue_empty_lockless(&rx->recvmsg_oobq) &&
+	    rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
+		release_sock(&rx->sk);
+		return -EAGAIN;
+	}
+
+	if (list_empty(&rx->recvmsg_q) &&
+	    skb_queue_empty_lockless(&rx->recvmsg_oobq)) {
+		ret = -EWOULDBLOCK;
+		if (timeo == 0) {
+			call = NULL;
+			goto error_no_call;
+		}
+
+		release_sock(&rx->sk);
+
+		/* Wait for something to happen */
+		prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
+					  TASK_INTERRUPTIBLE);
+		ret = sock_error(&rx->sk);
+		if (ret)
+			goto wait_error;
+
+		if (list_empty(&rx->recvmsg_q) &&
+		    skb_queue_empty_lockless(&rx->recvmsg_oobq)) {
+			if (signal_pending(current))
+				goto wait_interrupted;
+			trace_rxrpc_recvmsg(0, rxrpc_recvmsg_wait, 0);
+			timeo = schedule_timeout(timeo);
+		}
+		finish_wait(sk_sleep(&rx->sk), &wait);
+		goto try_again;
+	}
+
+	/* Deal with OOB messages before we consider getting normal data. */
+	if (!skb_queue_empty_lockless(&rx->recvmsg_oobq)) {
+		ret = rxrpc_recvmsg_oob(sock, msg, flags);
+		release_sock(&rx->sk);
+		if (ret == -EAGAIN)
+			goto try_again;
+		goto error_trace;
+	}
+
+	/* Find the next call and dequeue it if we're not just peeking.  If we
+	 * do dequeue it, that comes with a ref that we will need to release.
+	 * We also want to weed out calls that got requeued whilst we were
+	 * shovelling data out.
+	 */
+	spin_lock_irq(&rx->recvmsg_lock);
+	l = rx->recvmsg_q.next;
+	call = list_entry(l, struct rxrpc_call, recvmsg_link);
+
+	if (!rxrpc_call_is_complete(call) &&
+	    skb_queue_empty(&call->recvmsg_queue) &&
+	    skb_queue_empty(&rx->recvmsg_oobq)) {
+		list_del_init(&call->recvmsg_link);
+		spin_unlock_irq(&rx->recvmsg_lock);
+		release_sock(&rx->sk);
+		trace_rxrpc_recvmsg(call->debug_id, rxrpc_recvmsg_unqueue, 0);
+		rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+		goto try_again;
+	}
+
+	rxrpc_see_call(call, rxrpc_call_see_recvmsg);
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_already_released);
+		list_del_init(&call->recvmsg_link);
+		spin_unlock_irq(&rx->recvmsg_lock);
+		release_sock(&rx->sk);
+		trace_rxrpc_recvmsg(call->debug_id, rxrpc_recvmsg_unqueue, 0);
+		rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+		goto try_again;
+	}
+	if (!(flags & MSG_PEEK))
+		list_del_init(&call->recvmsg_link);
+	else
+		rxrpc_get_call(call, rxrpc_call_get_recvmsg);
+	spin_unlock_irq(&rx->recvmsg_lock);
+
+	call_debug_id = call->debug_id;
+	trace_rxrpc_recvmsg(call_debug_id, rxrpc_recvmsg_dequeue, 0);
+
+	/* We're going to drop the socket lock, so we need to lock the call
+	 * against interference by sendmsg.
+	 */
+	if (!mutex_trylock(&call->user_mutex)) {
+		ret = -EWOULDBLOCK;
+		if (flags & MSG_DONTWAIT)
+			goto error_requeue_call;
+		ret = -ERESTARTSYS;
+		if (mutex_lock_interruptible(&call->user_mutex) < 0)
+			goto error_requeue_call;
+	}
+
+	release_sock(&rx->sk);
+
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
+		rxrpc_see_call(call, rxrpc_call_see_already_released);
+		mutex_unlock(&call->user_mutex);
+		rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+		goto try_again;
+	}
+
+	ret = rxrpc_recvmsg_user_id(call, msg, flags);
+	if (ret < 0)
+		goto error_unlock_call;
+
+	if (msg->msg_name && call->peer) {
+		size_t len = sizeof(call->dest_srx);
+
+		memcpy(msg->msg_name, &call->dest_srx, len);
+		msg->msg_namelen = len;
+	}
+
+	ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len,
+				 flags, &copied);
+	if (ret == -EAGAIN)
+		ret = 0;
+	if (ret == -EIO)
+		goto call_failed;
+	if (ret < 0)
+		goto error_unlock_call;
+
+	if (rxrpc_call_is_complete(call) &&
+	    skb_queue_empty(&call->recvmsg_queue))
+		goto call_complete;
+	if (rxrpc_call_has_failed(call))
+		goto call_failed;
+
+	if (!(flags & MSG_PEEK) &&
+	    !skb_queue_empty(&call->recvmsg_queue))
+		rxrpc_notify_socket(call);
+	goto not_yet_complete;
+
+call_failed:
+	rxrpc_purge_queue(&call->recvmsg_queue);
+call_complete:
+	ret = rxrpc_recvmsg_term(call, msg);
+	if (ret < 0)
+		goto error_unlock_call;
+	if (!(flags & MSG_PEEK))
+		rxrpc_release_call(rx, call);
+	msg->msg_flags |= MSG_EOR;
+	ret = 1;
+
+not_yet_complete:
+	if (ret == 0)
+		msg->msg_flags |= MSG_MORE;
+	else
+		msg->msg_flags &= ~MSG_MORE;
+	ret = copied;
+
+error_unlock_call:
+	mutex_unlock(&call->user_mutex);
+	rxrpc_put_call(call, rxrpc_call_put_recvmsg);
+	trace_rxrpc_recvmsg(call_debug_id, rxrpc_recvmsg_return, ret);
+	return ret;
+
+error_requeue_call:
+	if (!(flags & MSG_PEEK)) {
+		spin_lock_irq(&rx->recvmsg_lock);
+		if (list_empty(&call->recvmsg_link)) {
+			list_add(&call->recvmsg_link, &rx->recvmsg_q);
+			rxrpc_see_call(call, rxrpc_call_see_recvmsg_requeue);
+			spin_unlock_irq(&rx->recvmsg_lock);
+		} else if (list_is_first(&call->recvmsg_link, &rx->recvmsg_q)) {
+			spin_unlock_irq(&rx->recvmsg_lock);
+			rxrpc_put_call(call, rxrpc_call_see_recvmsg_requeue_first);
+		} else {
+			list_move(&call->recvmsg_link, &rx->recvmsg_q);
+			spin_unlock_irq(&rx->recvmsg_lock);
+			rxrpc_put_call(call, rxrpc_call_see_recvmsg_requeue_move);
+		}
+		trace_rxrpc_recvmsg(call_debug_id, rxrpc_recvmsg_requeue, 0);
+	} else {
+		rxrpc_put_call(call, rxrpc_call_put_recvmsg_peek_nowait);
+	}
+error_no_call:
+	release_sock(&rx->sk);
+error_trace:
+	trace_rxrpc_recvmsg(call_debug_id, rxrpc_recvmsg_return, ret);
+	return ret;
+
+wait_interrupted:
+	ret = sock_intr_errno(timeo);
+wait_error:
+	finish_wait(sk_sleep(&rx->sk), &wait);
+	call = NULL;
+	goto error_trace;
+}
+
+/**
+ * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
+ * @sock: The socket that the call exists on
+ * @call: The call to send data through
+ * @iter: The buffer to receive into
+ * @_len: The amount of data we want to receive (decreased on return)
+ * @want_more: True if more data is expected to be read
+ * @_abort: Where the abort code is stored if -ECONNABORTED is returned
+ * @_service: Where to store the actual service ID (may be upgraded)
+ *
+ * Allow a kernel service to receive data and pick up information about the
+ * state of a call.  Note that *@_abort should also be initialised to %0.
+ *
+ * Note that we may return %-EAGAIN to drain empty packets at the end
+ * of the data, even if we've already copied over the requested data.
+ *
+ * Return: %0 if got what was asked for and there's more available, %1
+ * if we got what was asked for and we're at the end of the data and
+ * %-EAGAIN if we need more data.
+ */
+int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
+			   struct iov_iter *iter, size_t *_len,
+			   bool want_more, u32 *_abort, u16 *_service)
+{
+	size_t offset = 0;
+	int ret;
+
+	_enter("{%d},%zu,%d", call->debug_id, *_len, want_more);
+
+	mutex_lock(&call->user_mutex);
+
+	ret = rxrpc_recvmsg_data(sock, call, NULL, iter, *_len, 0, &offset);
+	*_len -= offset;
+	if (ret == -EIO)
+		goto call_failed;
+	if (ret < 0)
+		goto out;
+
+	/* We can only reach here with a partially full buffer if we have
+	 * reached the end of the data.  We must otherwise have a full buffer
+	 * or have been given -EAGAIN.
+	 */
+	if (ret == 1) {
+		if (iov_iter_count(iter) > 0)
+			goto short_data;
+		if (!want_more)
+			goto read_phase_complete;
+		ret = 0;
+		goto out;
+	}
+
+	if (!want_more)
+		goto excess_data;
+	goto out;
+
+read_phase_complete:
+	ret = 1;
+out:
+	if (_service)
+		*_service = call->dest_srx.srx_service;
+	mutex_unlock(&call->user_mutex);
+	_leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
+	return ret;
+
+short_data:
+	trace_rxrpc_abort(call->debug_id, rxrpc_recvmsg_short_data,
+			  call->cid, call->call_id, call->rx_consumed,
+			  0, -EBADMSG);
+	ret = -EBADMSG;
+	goto out;
+excess_data:
+	trace_rxrpc_abort(call->debug_id, rxrpc_recvmsg_excess_data,
+			  call->cid, call->call_id, call->rx_consumed,
+			  0, -EMSGSIZE);
+	ret = -EMSGSIZE;
+	goto out;
+call_failed:
+	*_abort = call->abort_code;
+	ret = call->error;
+	if (call->completion == RXRPC_CALL_SUCCEEDED) {
+		ret = 1;
+		if (iov_iter_count(iter) > 0)
+			ret = -ECONNRESET;
+	}
+	goto out;
+}
+EXPORT_SYMBOL(rxrpc_kernel_recv_data);
diff --git a/net/rxrpc/rtt.c b/net/rxrpc/rtt.c
new file mode 100644
index 000000000..7474f88d7
--- /dev/null
+++ b/net/rxrpc/rtt.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+/* RTT/RTO calculation.
+ *
+ * Adapted from TCP for AF_RXRPC by David Howells (dhowells@redhat.com)
+ *
+ * https://tools.ietf.org/html/rfc6298
+ * https://tools.ietf.org/html/rfc1122#section-4.2.3.1
+ * http://ccr.sigcomm.org/archive/1995/jan95/ccr-9501-partridge87.pdf
+ */
+
+#include <linux/net.h>
+#include "ar-internal.h"
+
+#define RXRPC_RTO_MAX	(120 * USEC_PER_SEC)
+#define RXRPC_TIMEOUT_INIT ((unsigned int)(1 * USEC_PER_SEC)) /* RFC6298 2.1 initial RTO value */
+#define rxrpc_jiffies32 ((u32)jiffies)		/* As rxrpc_jiffies32 */
+
+static u32 rxrpc_rto_min_us(struct rxrpc_call *call)
+{
+	return 200;
+}
+
+static u32 __rxrpc_set_rto(const struct rxrpc_call *call)
+{
+	return (call->srtt_us >> 3) + call->rttvar_us;
+}
+
+static u32 rxrpc_bound_rto(u32 rto)
+{
+	return clamp(200000, rto + 100000, RXRPC_RTO_MAX);
+}
+
+/*
+ * Called to compute a smoothed rtt estimate. The data fed to this
+ * routine either comes from timestamps, or from segments that were
+ * known _not_ to have been retransmitted [see Karn/Partridge
+ * Proceedings SIGCOMM 87]. The algorithm is from the SIGCOMM 88
+ * piece by Van Jacobson.
+ * NOTE: the next three routines used to be one big routine.
+ * To save cycles in the RFC 1323 implementation it was better to break
+ * it up into three procedures. -- erics
+ */
+static void rxrpc_rtt_estimator(struct rxrpc_call *call, long sample_rtt_us)
+{
+	long m = sample_rtt_us; /* RTT */
+	u32 srtt = call->srtt_us;
+
+	/*	The following amusing code comes from Jacobson's
+	 *	article in SIGCOMM '88.  Note that rtt and mdev
+	 *	are scaled versions of rtt and mean deviation.
+	 *	This is designed to be as fast as possible
+	 *	m stands for "measurement".
+	 *
+	 *	On a 1990 paper the rto value is changed to:
+	 *	RTO = rtt + 4 * mdev
+	 *
+	 * Funny. This algorithm seems to be very broken.
+	 * These formulae increase RTO, when it should be decreased, increase
+	 * too slowly, when it should be increased quickly, decrease too quickly
+	 * etc. I guess in BSD RTO takes ONE value, so that it is absolutely
+	 * does not matter how to _calculate_ it. Seems, it was trap
+	 * that VJ failed to avoid. 8)
+	 */
+	if (srtt != 0) {
+		m -= (srtt >> 3);	/* m is now error in rtt est */
+		srtt += m;		/* rtt = 7/8 rtt + 1/8 new */
+		if (m < 0) {
+			m = -m;		/* m is now abs(error) */
+			m -= (call->mdev_us >> 2);   /* similar update on mdev */
+			/* This is similar to one of Eifel findings.
+			 * Eifel blocks mdev updates when rtt decreases.
+			 * This solution is a bit different: we use finer gain
+			 * for mdev in this case (alpha*beta).
+			 * Like Eifel it also prevents growth of rto,
+			 * but also it limits too fast rto decreases,
+			 * happening in pure Eifel.
+			 */
+			if (m > 0)
+				m >>= 3;
+		} else {
+			m -= (call->mdev_us >> 2);   /* similar update on mdev */
+		}
+
+		call->mdev_us += m;		/* mdev = 3/4 mdev + 1/4 new */
+		if (call->mdev_us > call->mdev_max_us) {
+			call->mdev_max_us = call->mdev_us;
+			if (call->mdev_max_us > call->rttvar_us)
+				call->rttvar_us = call->mdev_max_us;
+		}
+	} else {
+		/* no previous measure. */
+		srtt = m << 3;		/* take the measured time to be rtt */
+		call->mdev_us = m << 1;	/* make sure rto = 3*rtt */
+		call->rttvar_us = umax(call->mdev_us, rxrpc_rto_min_us(call));
+		call->mdev_max_us = call->rttvar_us;
+	}
+
+	call->srtt_us = umax(srtt, 1);
+}
+
+/*
+ * Calculate rto without backoff.  This is the second half of Van Jacobson's
+ * routine referred to above.
+ */
+static void rxrpc_set_rto(struct rxrpc_call *call)
+{
+	u32 rto;
+
+	/* 1. If rtt variance happened to be less 50msec, it is hallucination.
+	 *    It cannot be less due to utterly erratic ACK generation made
+	 *    at least by solaris and freebsd. "Erratic ACKs" has _nothing_
+	 *    to do with delayed acks, because at cwnd>2 true delack timeout
+	 *    is invisible. Actually, Linux-2.4 also generates erratic
+	 *    ACKs in some circumstances.
+	 */
+	rto = __rxrpc_set_rto(call);
+
+	/* 2. Fixups made earlier cannot be right.
+	 *    If we do not estimate RTO correctly without them,
+	 *    all the algo is pure shit and should be replaced
+	 *    with correct one. It is exactly, which we pretend to do.
+	 */
+
+	/* NOTE: clamping at RXRPC_RTO_MIN is not required, current algo
+	 * guarantees that rto is higher.
+	 */
+	call->rto_us = rxrpc_bound_rto(rto);
+}
+
+static void rxrpc_update_rtt_min(struct rxrpc_call *call, ktime_t resp_time, long rtt_us)
+{
+	/* Window size 5mins in approx usec (ipv4.sysctl_tcp_min_rtt_wlen) */
+	u32 wlen_us = 5ULL * NSEC_PER_SEC / 1024;
+
+	minmax_running_min(&call->min_rtt, wlen_us, resp_time / 1024,
+			   (u32)rtt_us ? : jiffies_to_usecs(1));
+}
+
+static void rxrpc_ack_update_rtt(struct rxrpc_call *call, ktime_t resp_time, long rtt_us)
+{
+	if (rtt_us < 0)
+		return;
+
+	/* Update RACK min RTT [RFC8985 6.1 Step 1]. */
+	rxrpc_update_rtt_min(call, resp_time, rtt_us);
+
+	rxrpc_rtt_estimator(call, rtt_us);
+	rxrpc_set_rto(call);
+
+	/* Only reset backoff on valid RTT measurement [RFC6298]. */
+	call->backoff = 0;
+}
+
+/*
+ * Add RTT information to cache.  This is called in softirq mode and has
+ * exclusive access to the call RTT data.
+ */
+void rxrpc_call_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
+			int rtt_slot,
+			rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial,
+			ktime_t send_time, ktime_t resp_time)
+{
+	s64 rtt_us;
+
+	rtt_us = ktime_to_us(ktime_sub(resp_time, send_time));
+	if (rtt_us < 0)
+		return;
+
+	rxrpc_ack_update_rtt(call, resp_time, rtt_us);
+	if (call->rtt_count < 3)
+		call->rtt_count++;
+	call->rtt_taken++;
+
+	WRITE_ONCE(call->peer->recent_srtt_us, call->srtt_us / 8);
+	WRITE_ONCE(call->peer->recent_rto_us, call->rto_us);
+
+	trace_rxrpc_rtt_rx(call, why, rtt_slot, send_serial, resp_serial,
+			   rtt_us, call->srtt_us, call->rto_us);
+}
+
+/*
+ * Get the retransmission timeout to set in nanoseconds, backing it off each
+ * time we retransmit.
+ */
+ktime_t rxrpc_get_rto_backoff(struct rxrpc_call *call, bool retrans)
+{
+	u64 timo_us;
+	u32 backoff = READ_ONCE(call->backoff);
+
+	timo_us = call->rto_us;
+	timo_us <<= backoff;
+	if (retrans && timo_us * 2 <= RXRPC_RTO_MAX)
+		WRITE_ONCE(call->backoff, backoff + 1);
+
+	if (timo_us < 1)
+		timo_us = 1;
+
+	return ns_to_ktime(timo_us * NSEC_PER_USEC);
+}
+
+void rxrpc_call_init_rtt(struct rxrpc_call *call)
+{
+	call->rtt_last_req = KTIME_MIN;
+	call->rto_us	= RXRPC_TIMEOUT_INIT;
+	call->mdev_us	= RXRPC_TIMEOUT_INIT;
+	call->backoff	= 0;
+	//minmax_reset(&call->rtt_min, rxrpc_jiffies32, ~0U);
+}
diff --git a/net/rxrpc/rxgk.c b/net/rxrpc/rxgk.c
new file mode 100644
index 000000000..77a67ace1
--- /dev/null
+++ b/net/rxrpc/rxgk.c
@@ -0,0 +1,1355 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* GSSAPI-based RxRPC security
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/key-type.h>
+#include "ar-internal.h"
+#include "rxgk_common.h"
+
+/*
+ * Parse the information from a server key
+ */
+static int rxgk_preparse_server_key(struct key_preparsed_payload *prep)
+{
+	const struct krb5_enctype *krb5;
+	struct krb5_buffer *server_key = (void *)&prep->payload.data[2];
+	unsigned int service, sec_class, kvno, enctype;
+	int n = 0;
+
+	_enter("%zu", prep->datalen);
+
+	if (sscanf(prep->orig_description, "%u:%u:%u:%u%n",
+		   &service, &sec_class, &kvno, &enctype, &n) != 4)
+		return -EINVAL;
+
+	if (prep->orig_description[n])
+		return -EINVAL;
+
+	krb5 = crypto_krb5_find_enctype(enctype);
+	if (!krb5)
+		return -ENOPKG;
+
+	prep->payload.data[0] = (struct krb5_enctype *)krb5;
+
+	if (prep->datalen != krb5->key_len)
+		return -EKEYREJECTED;
+
+	server_key->len = prep->datalen;
+	server_key->data = kmemdup(prep->data, prep->datalen, GFP_KERNEL);
+	if (!server_key->data)
+		return -ENOMEM;
+
+	_leave(" = 0");
+	return 0;
+}
+
+static void rxgk_free_server_key(union key_payload *payload)
+{
+	struct krb5_buffer *server_key = (void *)&payload->data[2];
+
+	kfree_sensitive(server_key->data);
+}
+
+static void rxgk_free_preparse_server_key(struct key_preparsed_payload *prep)
+{
+	rxgk_free_server_key(&prep->payload);
+}
+
+static void rxgk_destroy_server_key(struct key *key)
+{
+	rxgk_free_server_key(&key->payload);
+}
+
+static void rxgk_describe_server_key(const struct key *key, struct seq_file *m)
+{
+	const struct krb5_enctype *krb5 = key->payload.data[0];
+
+	if (krb5)
+		seq_printf(m, ": %s", krb5->name);
+}
+
+/*
+ * Handle rekeying the connection when we see our limits overrun or when the
+ * far side decided to rekey.
+ *
+ * Returns a ref on the context if successful or -ESTALE if the key is out of
+ * date.
+ */
+static struct rxgk_context *rxgk_rekey(struct rxrpc_connection *conn,
+				       const u16 *specific_key_number)
+{
+	struct rxgk_context *gk, *dead = NULL;
+	unsigned int key_number, current_key, mask = ARRAY_SIZE(conn->rxgk.keys) - 1;
+	bool crank = false;
+
+	_enter("%d", specific_key_number ? *specific_key_number : -1);
+
+	mutex_lock(&conn->security_lock);
+
+	current_key = conn->rxgk.key_number;
+	if (!specific_key_number) {
+		key_number = current_key;
+	} else {
+		if (*specific_key_number == (u16)current_key)
+			key_number = current_key;
+		else if (*specific_key_number == (u16)(current_key - 1))
+			key_number = current_key - 1;
+		else if (*specific_key_number == (u16)(current_key + 1))
+			goto crank_window;
+		else
+			goto bad_key;
+	}
+
+	gk = conn->rxgk.keys[key_number & mask];
+	if (!gk)
+		goto generate_key;
+	if (!specific_key_number &&
+	    test_bit(RXGK_TK_NEEDS_REKEY, &gk->flags))
+		goto crank_window;
+
+grab:
+	refcount_inc(&gk->usage);
+	mutex_unlock(&conn->security_lock);
+	rxgk_put(dead);
+	return gk;
+
+crank_window:
+	trace_rxrpc_rxgk_rekey(conn, current_key,
+			       specific_key_number ? *specific_key_number : -1);
+	if (current_key == UINT_MAX)
+		goto bad_key;
+	if (current_key + 1 == UINT_MAX)
+		set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
+
+	key_number = current_key + 1;
+	if (WARN_ON(conn->rxgk.keys[key_number & mask]))
+		goto bad_key;
+	crank = true;
+
+generate_key:
+	gk = conn->rxgk.keys[current_key & mask];
+	gk = rxgk_generate_transport_key(conn, gk->key, key_number, GFP_NOFS);
+	if (IS_ERR(gk)) {
+		mutex_unlock(&conn->security_lock);
+		return gk;
+	}
+
+	write_lock(&conn->security_use_lock);
+	if (crank) {
+		current_key++;
+		conn->rxgk.key_number = current_key;
+		dead = conn->rxgk.keys[(current_key - 2) & mask];
+		conn->rxgk.keys[(current_key - 2) & mask] = NULL;
+	}
+	conn->rxgk.keys[current_key & mask] = gk;
+	write_unlock(&conn->security_use_lock);
+	goto grab;
+
+bad_key:
+	mutex_unlock(&conn->security_lock);
+	return ERR_PTR(-ESTALE);
+}
+
+/*
+ * Get the specified keying context.
+ *
+ * Returns a ref on the context if successful or -ESTALE if the key is out of
+ * date.
+ */
+static struct rxgk_context *rxgk_get_key(struct rxrpc_connection *conn,
+					 const u16 *specific_key_number)
+{
+	struct rxgk_context *gk;
+	unsigned int key_number, current_key, mask = ARRAY_SIZE(conn->rxgk.keys) - 1;
+
+	_enter("{%u},%d",
+	       conn->rxgk.key_number, specific_key_number ? *specific_key_number : -1);
+
+	read_lock(&conn->security_use_lock);
+
+	current_key = conn->rxgk.key_number;
+	if (!specific_key_number) {
+		key_number = current_key;
+	} else {
+		/* Only the bottom 16 bits of the key number are exposed in the
+		 * header, so we try and keep the upper 16 bits in step.  The
+		 * whole 32 bits are used to generate the TK.
+		 */
+		if (*specific_key_number == (u16)current_key)
+			key_number = current_key;
+		else if (*specific_key_number == (u16)(current_key - 1))
+			key_number = current_key - 1;
+		else if (*specific_key_number == (u16)(current_key + 1))
+			goto rekey;
+		else
+			goto bad_key;
+	}
+
+	gk = conn->rxgk.keys[key_number & mask];
+	if (!gk)
+		goto slow_path;
+	if (!specific_key_number &&
+	    key_number < UINT_MAX) {
+		if (time_after(jiffies, gk->expiry) ||
+		    gk->bytes_remaining < 0) {
+			set_bit(RXGK_TK_NEEDS_REKEY, &gk->flags);
+			goto slow_path;
+		}
+
+		if (test_bit(RXGK_TK_NEEDS_REKEY, &gk->flags))
+			goto slow_path;
+	}
+
+	refcount_inc(&gk->usage);
+	read_unlock(&conn->security_use_lock);
+	return gk;
+
+rekey:
+	_debug("rekey");
+	if (current_key == UINT_MAX)
+		goto bad_key;
+	gk = conn->rxgk.keys[current_key & mask];
+	if (gk)
+		set_bit(RXGK_TK_NEEDS_REKEY, &gk->flags);
+slow_path:
+	read_unlock(&conn->security_use_lock);
+	return rxgk_rekey(conn, specific_key_number);
+bad_key:
+	read_unlock(&conn->security_use_lock);
+	return ERR_PTR(-ESTALE);
+}
+
+/*
+ * initialise connection security
+ */
+static int rxgk_init_connection_security(struct rxrpc_connection *conn,
+					 struct rxrpc_key_token *token)
+{
+	struct rxgk_context *gk;
+	int ret;
+
+	_enter("{%d,%u},{%x}",
+	       conn->debug_id, conn->rxgk.key_number, key_serial(conn->key));
+
+	conn->security_ix = token->security_index;
+	conn->security_level = token->rxgk->level;
+
+	if (rxrpc_conn_is_client(conn)) {
+		conn->rxgk.start_time = ktime_get();
+		do_div(conn->rxgk.start_time, 100);
+	}
+
+	gk = rxgk_generate_transport_key(conn, token->rxgk, conn->rxgk.key_number,
+					 GFP_NOFS);
+	if (IS_ERR(gk))
+		return PTR_ERR(gk);
+	conn->rxgk.enctype = gk->krb5->etype;
+	conn->rxgk.keys[gk->key_number & 3] = gk;
+
+	switch (conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+	case RXRPC_SECURITY_AUTH:
+	case RXRPC_SECURITY_ENCRYPT:
+		break;
+	default:
+		ret = -EKEYREJECTED;
+		goto error;
+	}
+
+	ret = 0;
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Clean up the crypto on a call.
+ */
+static void rxgk_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+/*
+ * Work out how much data we can put in a packet.
+ */
+static struct rxrpc_txbuf *rxgk_alloc_txbuf(struct rxrpc_call *call, size_t remain, gfp_t gfp)
+{
+	enum krb5_crypto_mode mode;
+	struct rxgk_context *gk;
+	struct rxrpc_txbuf *txb;
+	size_t shdr, alloc, limit, part, offset, gap;
+
+	switch (call->conn->security_level) {
+	default:
+		alloc = umin(remain, RXRPC_JUMBO_DATALEN);
+		return rxrpc_alloc_data_txbuf(call, alloc, 1, gfp);
+	case RXRPC_SECURITY_AUTH:
+		shdr = 0;
+		mode = KRB5_CHECKSUM_MODE;
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		shdr = sizeof(struct rxgk_header);
+		mode = KRB5_ENCRYPT_MODE;
+		break;
+	}
+
+	gk = rxgk_get_key(call->conn, NULL);
+	if (IS_ERR(gk))
+		return NULL;
+
+	/* Work out the maximum amount of data that will fit. */
+	alloc = RXRPC_JUMBO_DATALEN;
+	limit = crypto_krb5_how_much_data(gk->krb5, mode, &alloc, &offset);
+
+	if (remain < limit - shdr) {
+		part = remain;
+		alloc = crypto_krb5_how_much_buffer(gk->krb5, mode,
+						    shdr + part, &offset);
+		gap = 0;
+	} else {
+		part = limit - shdr;
+		gap = RXRPC_JUMBO_DATALEN - alloc;
+		alloc = RXRPC_JUMBO_DATALEN;
+	}
+
+	rxgk_put(gk);
+
+	txb = rxrpc_alloc_data_txbuf(call, alloc, 16, gfp);
+	if (!txb)
+		return NULL;
+
+	txb->crypto_header	= offset;
+	txb->sec_header		= shdr;
+	txb->offset		+= offset + shdr;
+	txb->space		= part;
+
+	/* Clear excess space in the packet */
+	if (gap)
+		memset(txb->data + alloc - gap, 0, gap);
+	return txb;
+}
+
+/*
+ * Integrity mode (sign a packet - level 1 security)
+ */
+static int rxgk_secure_packet_integrity(const struct rxrpc_call *call,
+					struct rxgk_context *gk,
+					struct rxrpc_txbuf *txb)
+{
+	struct rxgk_header *hdr;
+	struct scatterlist sg[1];
+	struct krb5_buffer metadata;
+	int ret = -ENOMEM;
+
+	_enter("");
+
+	hdr = kzalloc_obj(*hdr, GFP_NOFS);
+	if (!hdr)
+		goto error_gk;
+
+	hdr->epoch	= htonl(call->conn->proto.epoch);
+	hdr->cid	= htonl(call->cid);
+	hdr->call_number = htonl(call->call_id);
+	hdr->seq	= htonl(txb->seq);
+	hdr->sec_index	= htonl(call->security_ix);
+	hdr->data_len	= htonl(txb->len);
+	metadata.len = sizeof(*hdr);
+	metadata.data = hdr;
+
+	sg_init_table(sg, 1);
+	sg_set_buf(&sg[0], txb->data, txb->alloc_size);
+
+	ret = crypto_krb5_get_mic(gk->krb5, gk->tx_Kc, &metadata,
+				  sg, 1, txb->alloc_size,
+				  txb->crypto_header, txb->sec_header + txb->len);
+	if (ret >= 0) {
+		txb->pkt_len = ret;
+		if (txb->alloc_size == RXRPC_JUMBO_DATALEN)
+			txb->jumboable = true;
+		gk->bytes_remaining -= ret;
+	}
+	kfree(hdr);
+error_gk:
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * wholly encrypt a packet (level 2 security)
+ */
+static int rxgk_secure_packet_encrypted(const struct rxrpc_call *call,
+					struct rxgk_context *gk,
+					struct rxrpc_txbuf *txb)
+{
+	struct rxgk_header *hdr;
+	struct scatterlist sg[1];
+	int ret;
+
+	_enter("%x", txb->len);
+
+	/* Insert the header into the buffer. */
+	hdr = txb->data + txb->crypto_header;
+	hdr->epoch	 = htonl(call->conn->proto.epoch);
+	hdr->cid	 = htonl(call->cid);
+	hdr->call_number = htonl(call->call_id);
+	hdr->seq	 = htonl(txb->seq);
+	hdr->sec_index	 = htonl(call->security_ix);
+	hdr->data_len	 = htonl(txb->len);
+
+	sg_init_table(sg, 1);
+	sg_set_buf(&sg[0], txb->data, txb->alloc_size);
+
+	ret = crypto_krb5_encrypt(gk->krb5, gk->tx_enc,
+				  sg, 1, txb->alloc_size,
+				  txb->crypto_header, txb->sec_header + txb->len,
+				  false);
+	if (ret >= 0) {
+		txb->pkt_len = ret;
+		if (txb->alloc_size == RXRPC_JUMBO_DATALEN)
+			txb->jumboable = true;
+		gk->bytes_remaining -= ret;
+	}
+
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * checksum an RxRPC packet header
+ */
+static int rxgk_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
+{
+	struct rxgk_context *gk;
+	int ret;
+
+	_enter("{%d{%x}},{#%u},%u,",
+	       call->debug_id, key_serial(call->conn->key), txb->seq, txb->len);
+
+	gk = rxgk_get_key(call->conn, NULL);
+	if (IS_ERR(gk))
+		return PTR_ERR(gk) == -ESTALE ? -EKEYREJECTED : PTR_ERR(gk);
+
+	ret = key_validate(call->conn->key);
+	if (ret < 0) {
+		rxgk_put(gk);
+		return ret;
+	}
+
+	call->security_enctype = gk->krb5->etype;
+	txb->cksum = htons(gk->key_number);
+
+	switch (call->conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		rxgk_put(gk);
+		txb->pkt_len = txb->len;
+		return 0;
+	case RXRPC_SECURITY_AUTH:
+		return rxgk_secure_packet_integrity(call, gk, txb);
+	case RXRPC_SECURITY_ENCRYPT:
+		return rxgk_secure_packet_encrypted(call, gk, txb);
+	default:
+		rxgk_put(gk);
+		return -EPERM;
+	}
+}
+
+/*
+ * Integrity mode (check the signature on a packet - level 1 security)
+ */
+static int rxgk_verify_packet_integrity(struct rxrpc_call *call,
+					struct rxgk_context *gk,
+					struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxgk_header *hdr;
+	struct krb5_buffer metadata;
+	unsigned int len = call->rx_dec_len;
+	size_t data_offset = 0, data_len = len;
+	void *data = call->rx_dec_buffer, *p = data;
+	u32 ac = 0;
+	int ret = -ENOMEM;
+
+	_enter("");
+
+	if (crypto_krb5_where_is_the_data(gk->krb5, KRB5_CHECKSUM_MODE,
+					  &data_offset, &data_len) < 0) {
+		ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT,
+					 rxgk_abort_1_short_header);
+		goto put_gk;
+	}
+
+	hdr = kzalloc_obj(*hdr, GFP_NOFS);
+	if (!hdr)
+		goto put_gk;
+
+	hdr->epoch	= htonl(call->conn->proto.epoch);
+	hdr->cid	= htonl(call->cid);
+	hdr->call_number = htonl(call->call_id);
+	hdr->seq	= htonl(sp->hdr.seq);
+	hdr->sec_index	= htonl(call->security_ix);
+	hdr->data_len	= htonl(data_len);
+
+	metadata.len = sizeof(*hdr);
+	metadata.data = hdr;
+	ret = rxgk_verify_mic(gk->krb5, gk->rx_Kc, &metadata, &p, &len, &ac);
+	kfree(hdr);
+	if (ret < 0) {
+		if (ret != -ENOMEM)
+			rxrpc_abort_eproto(call, skb, ac,
+					   rxgk_abort_1_verify_mic_eproto);
+	} else {
+		call->rx_dec_offset = p - data;
+		call->rx_dec_len = len;
+	}
+
+put_gk:
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Decrypt an encrypted packet (level 2 security).
+ */
+static int rxgk_verify_packet_encrypted(struct rxrpc_call *call,
+					struct rxgk_context *gk,
+					struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxgk_header *hdr;
+	unsigned int offset = 0, len = call->rx_dec_len;
+	void *data = call->rx_dec_buffer, *p = data;
+	int ret;
+	u32 ac = 0;
+
+	_enter("");
+
+	if (crypto_krb5_check_data_len(gk->krb5, KRB5_ENCRYPT_MODE,
+				       len, sizeof(*hdr)) < 0) {
+		ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT,
+					 rxgk_abort_2_short_header);
+		goto error;
+	}
+
+	ret = rxgk_decrypt(gk->krb5, gk->rx_enc, &p, &len, &ac);
+	if (ret < 0) {
+		if (ret != -ENOMEM)
+			rxrpc_abort_eproto(call, skb, ac, rxgk_abort_2_decrypt_eproto);
+		goto error;
+	}
+	offset = p - data;
+
+	if (len < sizeof(*hdr)) {
+		ret = rxrpc_abort_eproto(call, skb, RXGK_PACKETSHORT,
+					 rxgk_abort_2_short_header);
+		goto error;
+	}
+
+	/* Extract the header from the skb */
+	hdr = data + offset;
+	offset += sizeof(*hdr);
+	len -= sizeof(*hdr);
+
+	if (ntohl(hdr->epoch)		!= call->conn->proto.epoch ||
+	    ntohl(hdr->cid)		!= call->cid ||
+	    ntohl(hdr->call_number)	!= call->call_id ||
+	    ntohl(hdr->seq)		!= sp->hdr.seq ||
+	    ntohl(hdr->sec_index)	!= call->security_ix ||
+	    ntohl(hdr->data_len)	> len) {
+		ret = rxrpc_abort_eproto(call, skb, RXGK_SEALEDINCON,
+					 rxgk_abort_2_short_data);
+		goto error;
+	}
+
+	call->rx_dec_offset = offset;
+	call->rx_dec_len = ntohl(hdr->data_len);
+	ret = 0;
+error:
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Verify the security on a received packet or subpacket (if part of a
+ * jumbo packet).
+ */
+static int rxgk_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxgk_context *gk;
+	u16 key_number = sp->hdr.cksum;
+
+	_enter("{%d{%x}},{#%u}",
+	       call->debug_id, key_serial(call->conn->key), sp->hdr.seq);
+
+	gk = rxgk_get_key(call->conn, &key_number);
+	if (IS_ERR(gk)) {
+		switch (PTR_ERR(gk)) {
+		case -ESTALE:
+			return rxrpc_abort_eproto(call, skb, RXGK_BADKEYNO,
+						  rxgk_abort_bad_key_number);
+		default:
+			return PTR_ERR(gk);
+		}
+	}
+
+	call->security_enctype = gk->krb5->etype;
+	switch (call->conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		rxgk_put(gk);
+		return 0;
+	case RXRPC_SECURITY_AUTH:
+		return rxgk_verify_packet_integrity(call, gk, skb);
+	case RXRPC_SECURITY_ENCRYPT:
+		return rxgk_verify_packet_encrypted(call, gk, skb);
+	default:
+		rxgk_put(gk);
+		return -ENOANO;
+	}
+}
+
+/*
+ * Allocate memory to hold a challenge or a response packet.  We're not running
+ * in the io_thread, so we can't use ->tx_alloc.
+ */
+static struct page *rxgk_alloc_packet(size_t total_len)
+{
+	gfp_t gfp = GFP_NOFS;
+	int order;
+
+	order = get_order(total_len);
+	if (order > 0)
+		gfp |= __GFP_COMP;
+	return alloc_pages(gfp, order);
+}
+
+/*
+ * Issue a challenge.
+ */
+static int rxgk_issue_challenge(struct rxrpc_connection *conn)
+{
+	struct rxrpc_wire_header *whdr;
+	struct bio_vec bvec[1];
+	struct msghdr msg;
+	struct page *page;
+	size_t len = sizeof(*whdr) + sizeof(conn->rxgk.nonce);
+	u32 serial;
+	int ret;
+
+	_enter("{%d}", conn->debug_id);
+
+	get_random_bytes(&conn->rxgk.nonce, sizeof(conn->rxgk.nonce));
+
+	/* We can't use conn->tx_alloc without a lock */
+	page = rxgk_alloc_packet(sizeof(*whdr) + sizeof(conn->rxgk.nonce));
+	if (!page)
+		return -ENOMEM;
+
+	bvec_set_page(&bvec[0], page, len, 0);
+	iov_iter_bvec(&msg.msg_iter, WRITE, bvec, 1, len);
+
+	msg.msg_name	= &conn->peer->srx.transport;
+	msg.msg_namelen	= conn->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= MSG_SPLICE_PAGES;
+
+	whdr = page_address(page);
+	whdr->epoch	= htonl(conn->proto.epoch);
+	whdr->cid	= htonl(conn->proto.cid);
+	whdr->callNumber = 0;
+	whdr->seq	= 0;
+	whdr->type	= RXRPC_PACKET_TYPE_CHALLENGE;
+	whdr->flags	= conn->out_clientflag;
+	whdr->userStatus = 0;
+	whdr->securityIndex = conn->security_ix;
+	whdr->_rsvd	= 0;
+	whdr->serviceId	= htons(conn->service_id);
+
+	memcpy(whdr + 1, conn->rxgk.nonce, sizeof(conn->rxgk.nonce));
+
+	serial = rxrpc_get_next_serials(conn, 1);
+	whdr->serial = htonl(serial);
+
+	trace_rxrpc_tx_challenge(conn, serial, 0, *(u32 *)&conn->rxgk.nonce);
+
+	ret = do_udp_sendmsg(conn->local->socket, &msg, len);
+	if (ret > 0)
+		rxrpc_peer_mark_tx(conn->peer);
+
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_rxgk_challenge);
+		__free_page(page);
+		return -EAGAIN;
+	}
+
+	trace_rxrpc_tx_packet(conn->debug_id, whdr,
+			      rxrpc_tx_point_rxgk_challenge);
+	__free_page(page);
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Validate a challenge packet.
+ */
+static bool rxgk_validate_challenge(struct rxrpc_connection *conn,
+				    struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	u8 nonce[20];
+
+	if (!conn->key) {
+		rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO,
+				 rxgk_abort_chall_no_key);
+		return false;
+	}
+
+	if (key_validate(conn->key) < 0) {
+		rxrpc_abort_conn(conn, skb, RXGK_EXPIRED, -EPROTO,
+				 rxgk_abort_chall_key_expired);
+		return false;
+	}
+
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  nonce, sizeof(nonce)) < 0) {
+		rxrpc_abort_conn(conn, skb, RXGK_PACKETSHORT, -EPROTO,
+				 rxgk_abort_chall_short);
+		return false;
+	}
+
+	trace_rxrpc_rx_challenge(conn, sp->hdr.serial, 0, *(u32 *)nonce, 0);
+	return true;
+}
+
+/**
+ * rxgk_kernel_query_challenge - Query RxGK-specific challenge parameters
+ * @challenge: The challenge packet to query
+ *
+ * Return: The Kerberos 5 encoding type for the challenged connection.
+ */
+u32 rxgk_kernel_query_challenge(struct sk_buff *challenge)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(challenge);
+
+	return sp->chall.conn->rxgk.enctype;
+}
+EXPORT_SYMBOL(rxgk_kernel_query_challenge);
+
+/*
+ * Fill out the control message to pass to userspace to inform about the
+ * challenge.
+ */
+static int rxgk_challenge_to_recvmsg(struct rxrpc_connection *conn,
+				     struct sk_buff *challenge,
+				     struct msghdr *msg)
+{
+	struct rxgk_challenge chall;
+
+	chall.base.service_id		= conn->service_id;
+	chall.base.security_index	= conn->security_ix;
+	chall.enctype			= conn->rxgk.enctype;
+
+	return put_cmsg(msg, SOL_RXRPC, RXRPC_CHALLENGED, sizeof(chall), &chall);
+}
+
+/*
+ * Insert the requisite amount of XDR padding for the length given.
+ */
+static int rxgk_pad_out(struct sk_buff *response, size_t len, size_t offset)
+{
+	__be32 zero = 0;
+	size_t pad = xdr_round_up(len) - len;
+	int ret;
+
+	if (!pad)
+		return 0;
+
+	ret = skb_store_bits(response, offset, &zero, pad);
+	if (ret < 0)
+		return ret;
+	return pad;
+}
+
+/*
+ * Insert the header into the response.
+ */
+static noinline ssize_t rxgk_insert_response_header(struct rxrpc_connection *conn,
+						    struct rxgk_context *gk,
+						    struct sk_buff *response,
+						    size_t offset)
+{
+	struct rxrpc_skb_priv *rsp = rxrpc_skb(response);
+
+	struct {
+		struct rxrpc_wire_header whdr;
+		__be32 start_time_msw;
+		__be32 start_time_lsw;
+		__be32 ticket_len;
+	} h;
+	int ret;
+
+	rsp->resp.kvno		= gk->key_number;
+	rsp->resp.version	= gk->krb5->etype;
+
+	h.whdr.epoch		= htonl(conn->proto.epoch);
+	h.whdr.cid		= htonl(conn->proto.cid);
+	h.whdr.callNumber	= 0;
+	h.whdr.serial		= 0;
+	h.whdr.seq		= 0;
+	h.whdr.type		= RXRPC_PACKET_TYPE_RESPONSE;
+	h.whdr.flags		= conn->out_clientflag;
+	h.whdr.userStatus	= 0;
+	h.whdr.securityIndex	= conn->security_ix;
+	h.whdr.cksum		= htons(gk->key_number);
+	h.whdr.serviceId	= htons(conn->service_id);
+	h.start_time_msw	= htonl(upper_32_bits(conn->rxgk.start_time));
+	h.start_time_lsw	= htonl(lower_32_bits(conn->rxgk.start_time));
+	h.ticket_len		= htonl(gk->key->ticket.len);
+
+	ret = skb_store_bits(response, offset, &h, sizeof(h));
+	return ret < 0 ? ret : sizeof(h);
+}
+
+/*
+ * Construct the authenticator to go in the response packet
+ *
+ * struct RXGK_Authenticator {
+ *	opaque nonce[20];
+ *	opaque appdata<>;
+ *	RXGK_Level level;
+ *	unsigned int epoch;
+ *	unsigned int cid;
+ *	unsigned int call_numbers<>;
+ * };
+ */
+static ssize_t rxgk_construct_authenticator(struct rxrpc_connection *conn,
+					    struct sk_buff *challenge,
+					    const struct krb5_buffer *appdata,
+					    struct sk_buff *response,
+					    size_t offset)
+{
+	struct {
+		u8	nonce[20];
+		__be32	appdata_len;
+	} a;
+	struct {
+		__be32	level;
+		__be32	epoch;
+		__be32	cid;
+		__be32	call_numbers_count;
+		__be32	call_numbers[4];
+	} b;
+	int ret;
+
+	ret = skb_copy_bits(challenge, sizeof(struct rxrpc_wire_header),
+			    a.nonce, sizeof(a.nonce));
+	if (ret < 0)
+		return -EPROTO;
+
+	a.appdata_len = htonl(appdata->len);
+
+	ret = skb_store_bits(response, offset, &a, sizeof(a));
+	if (ret < 0)
+		return ret;
+	offset += sizeof(a);
+
+	if (appdata->len) {
+		ret = skb_store_bits(response, offset, appdata->data, appdata->len);
+		if (ret < 0)
+			return ret;
+		offset += appdata->len;
+
+		ret = rxgk_pad_out(response, appdata->len, offset);
+		if (ret < 0)
+			return ret;
+		offset += ret;
+	}
+
+	b.level			= htonl(conn->security_level);
+	b.epoch			= htonl(conn->proto.epoch);
+	b.cid			= htonl(conn->proto.cid);
+	b.call_numbers_count	= htonl(4);
+	b.call_numbers[0]	= htonl(conn->channels[0].call_counter);
+	b.call_numbers[1]	= htonl(conn->channels[1].call_counter);
+	b.call_numbers[2]	= htonl(conn->channels[2].call_counter);
+	b.call_numbers[3]	= htonl(conn->channels[3].call_counter);
+
+	ret = skb_store_bits(response, offset, &b, sizeof(b));
+	if (ret < 0)
+		return ret;
+	return sizeof(a) + xdr_round_up(appdata->len) + sizeof(b);
+}
+
+static ssize_t rxgk_encrypt_authenticator(struct rxrpc_connection *conn,
+					  struct rxgk_context *gk,
+					  struct sk_buff *response,
+					  size_t offset,
+					  size_t alloc_len,
+					  size_t auth_offset,
+					  size_t auth_len)
+{
+	struct scatterlist sg[16];
+	int nr_sg;
+
+	sg_init_table(sg, ARRAY_SIZE(sg));
+	nr_sg = skb_to_sgvec(response, sg, offset, alloc_len);
+	if (unlikely(nr_sg < 0))
+		return nr_sg;
+	return crypto_krb5_encrypt(gk->krb5, gk->resp_enc, sg, nr_sg, alloc_len,
+				   auth_offset, auth_len, false);
+}
+
+/*
+ * Construct the response.
+ *
+ * struct RXGK_Response {
+ *	rxgkTime start_time;
+ *	RXGK_Data token;
+ *	opaque authenticator<RXGK_MAXAUTHENTICATOR>
+ * };
+ */
+static int rxgk_construct_response(struct rxrpc_connection *conn,
+				   struct sk_buff *challenge,
+				   struct krb5_buffer *appdata)
+{
+	struct rxrpc_skb_priv *csp, *rsp;
+	struct rxgk_context *gk;
+	struct sk_buff *response;
+	size_t len, auth_len, authx_len, offset, auth_offset, authx_offset;
+	__be32 tmp;
+	int ret;
+
+	gk = rxgk_get_key(conn, NULL);
+	if (IS_ERR(gk))
+		return PTR_ERR(gk);
+
+	auth_len = 20 + (4 + appdata->len) + 12 + (1 + 4) * 4;
+	authx_len = crypto_krb5_how_much_buffer(gk->krb5, KRB5_ENCRYPT_MODE,
+						auth_len, &auth_offset);
+	len = sizeof(struct rxrpc_wire_header) +
+		8 + (4 + xdr_round_up(gk->key->ticket.len)) + (4 + authx_len);
+
+	response = alloc_skb_with_frags(0, len, 0, &ret, GFP_NOFS);
+	if (!response)
+		goto error;
+	rxrpc_new_skb(response, rxrpc_skb_new_response_rxgk);
+	response->len = len;
+	response->data_len = len;
+
+	ret = rxgk_insert_response_header(conn, gk, response, 0);
+	if (ret < 0)
+		goto error;
+	offset = ret;
+
+	ret = skb_store_bits(response, offset, gk->key->ticket.data, gk->key->ticket.len);
+	if (ret < 0)
+		goto error;
+	offset += gk->key->ticket.len;
+	ret = rxgk_pad_out(response, gk->key->ticket.len, offset);
+	if (ret < 0)
+		goto error;
+
+	authx_offset = offset + ret + 4; /* Leave a gap for the length. */
+
+	ret = rxgk_construct_authenticator(conn, challenge, appdata, response,
+					   authx_offset + auth_offset);
+	if (ret < 0)
+		goto error;
+	auth_len = ret;
+
+	ret = rxgk_encrypt_authenticator(conn, gk, response,
+					 authx_offset, authx_len,
+					 auth_offset, auth_len);
+	if (ret < 0)
+		goto error;
+	authx_len = ret;
+
+	tmp = htonl(authx_len);
+	ret = skb_store_bits(response, authx_offset - 4, &tmp, 4);
+	if (ret < 0)
+		goto error;
+
+	ret = rxgk_pad_out(response, authx_len, authx_offset + authx_len);
+	if (ret < 0)
+		goto error;
+	len = authx_offset + authx_len + ret;
+
+	if (len != response->len) {
+		response->len = len;
+		response->data_len = len;
+	}
+
+	csp = rxrpc_skb(challenge);
+	rsp = rxrpc_skb(response);
+	rsp->resp.len = len;
+	rsp->resp.challenge_serial = csp->hdr.serial;
+	rxrpc_post_response(conn, response);
+	response = NULL;
+	ret = 0;
+
+error:
+	rxrpc_free_skb(response, rxrpc_skb_put_response);
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Respond to a challenge packet.
+ */
+static int rxgk_respond_to_challenge(struct rxrpc_connection *conn,
+				     struct sk_buff *challenge,
+				     struct krb5_buffer *appdata)
+{
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
+
+	if (key_validate(conn->key) < 0)
+		return rxrpc_abort_conn(conn, NULL, RXGK_EXPIRED, -EPROTO,
+					rxgk_abort_chall_key_expired);
+
+	return rxgk_construct_response(conn, challenge, appdata);
+}
+
+static int rxgk_respond_to_challenge_no_appdata(struct rxrpc_connection *conn,
+						struct sk_buff *challenge)
+{
+	struct krb5_buffer appdata = {};
+
+	return rxgk_respond_to_challenge(conn, challenge, &appdata);
+}
+
+/**
+ * rxgk_kernel_respond_to_challenge - Respond to a challenge with appdata
+ * @challenge: The challenge to respond to
+ * @appdata: The application data to include in the RESPONSE authenticator
+ *
+ * Allow a kernel application to respond to a CHALLENGE with application data
+ * to be included in the RxGK RESPONSE Authenticator.
+ *
+ * Return: %0 if successful and a negative error code otherwise.
+ */
+int rxgk_kernel_respond_to_challenge(struct sk_buff *challenge,
+				     struct krb5_buffer *appdata)
+{
+	struct rxrpc_skb_priv *csp = rxrpc_skb(challenge);
+
+	return rxgk_respond_to_challenge(csp->chall.conn, challenge, appdata);
+}
+EXPORT_SYMBOL(rxgk_kernel_respond_to_challenge);
+
+/*
+ * Parse sendmsg() control message and respond to challenge.  We need to see if
+ * there's an appdata to fish out.
+ */
+static int rxgk_sendmsg_respond_to_challenge(struct sk_buff *challenge,
+					     struct msghdr *msg)
+{
+	struct krb5_buffer appdata = {};
+	struct cmsghdr *cmsg;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (cmsg->cmsg_level != SOL_RXRPC ||
+		    cmsg->cmsg_type != RXRPC_RESP_RXGK_APPDATA)
+			continue;
+		if (appdata.data)
+			return -EINVAL;
+		appdata.data = CMSG_DATA(cmsg);
+		appdata.len = cmsg->cmsg_len - sizeof(struct cmsghdr);
+	}
+
+	return rxgk_kernel_respond_to_challenge(challenge, &appdata);
+}
+
+/*
+ * Verify the authenticator.
+ *
+ * struct RXGK_Authenticator {
+ *	opaque nonce[20];
+ *	opaque appdata<>;
+ *	RXGK_Level level;
+ *	unsigned int epoch;
+ *	unsigned int cid;
+ *	unsigned int call_numbers<>;
+ * };
+ */
+static int rxgk_verify_authenticator(struct rxrpc_connection *conn,
+				     const struct krb5_enctype *krb5,
+				     struct sk_buff *skb,
+				     void *auth, unsigned int auth_len)
+{
+	__be32 *p = auth, *end = auth + auth_len;
+	u32 app_len, call_count, level, epoch, cid, i;
+
+	_enter("");
+
+	if ((end - p) * sizeof(__be32) < 24)
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_short_auth);
+	if (memcmp(p, conn->rxgk.nonce, 20) != 0)
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_bad_nonce);
+	p += 20 / sizeof(__be32);
+
+	app_len	= ntohl(*p++);
+	if (app_len > (end - p) * sizeof(__be32))
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_short_applen);
+
+	p += xdr_round_up(app_len) / sizeof(__be32);
+	if (end - p < 4)
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_short_auth);
+
+	level	= ntohl(*p++);
+	epoch	= ntohl(*p++);
+	cid	= ntohl(*p++);
+	call_count = ntohl(*p++);
+
+	if (level	!= conn->security_level ||
+	    epoch	!= conn->proto.epoch ||
+	    cid		!= conn->proto.cid ||
+	    call_count	> 4)
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_bad_param);
+
+	if (end - p < call_count)
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+					rxgk_abort_resp_short_call_list);
+
+	for (i = 0; i < call_count; i++) {
+		u32 call_id = ntohl(*p++);
+
+		if (call_id > INT_MAX)
+			return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+						rxgk_abort_resp_bad_callid);
+
+		if (call_id < conn->channels[i].call_counter)
+			return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+						rxgk_abort_resp_call_ctr);
+
+		if (call_id > conn->channels[i].call_counter) {
+			if (conn->channels[i].call)
+				return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EPROTO,
+							rxgk_abort_resp_call_state);
+
+			conn->channels[i].call_counter = call_id;
+		}
+	}
+
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Verify a response.
+ *
+ * struct RXGK_Response {
+ *	rxgkTime	start_time;
+ *	RXGK_Data	token;
+ *	opaque		authenticator<RXGK_MAXAUTHENTICATOR>
+ * };
+ */
+static int rxgk_verify_response(struct rxrpc_connection *conn,
+				struct sk_buff *skb,
+				void *buffer, unsigned int len)
+{
+	const struct krb5_enctype *krb5;
+	struct rxrpc_key_token *token;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxgk_response *rhdr;
+	struct rxgk_context *gk;
+	struct key *key = NULL;
+	unsigned int resp_token_len, auth_len;
+	void *resp_token, *auth;
+	__be32 xauth_len;
+	int ret, ec;
+
+	_enter("{%d}", conn->debug_id);
+
+	/* Parse the RXGK_Response object */
+	if (len < sizeof(*rhdr) + sizeof(__be32))
+		goto short_packet;
+	rhdr = buffer;
+	buffer	+= sizeof(*rhdr);
+	len	-= sizeof(*rhdr);
+
+	resp_token	= buffer;
+	resp_token_len	= ntohl(rhdr->token_len);
+	if (resp_token_len > len ||
+	    xdr_round_up(resp_token_len) + sizeof(__be32) > len)
+		goto short_packet;
+
+	trace_rxrpc_rx_response(conn, sp->hdr.serial, 0, sp->hdr.cksum, resp_token_len);
+
+	buffer	+= xdr_round_up(resp_token_len);
+	len	-= xdr_round_up(resp_token_len);
+
+	xauth_len = *(__be32 *)buffer;
+	buffer	+= sizeof(xauth_len);
+	len	-= sizeof(xauth_len);
+
+	auth		= buffer;
+	auth_len	= ntohl(xauth_len);
+	if (auth_len > len)
+		goto short_packet;
+	if (auth_len & 3)
+		goto inconsistent;
+	if (auth_len < 20 + 9 * 4)
+		goto auth_too_short;
+
+	/* We need to extract and decrypt the token and instantiate a session
+	 * key for it.  This bit, however, is application-specific.  If
+	 * possible, we use a default parser, but we might end up bumping this
+	 * to the app to deal with - which might mean a round trip to
+	 * userspace.
+	 */
+	ret = rxgk_extract_token(conn, skb, resp_token, resp_token_len, &key);
+	if (ret < 0)
+		goto out;
+
+	/* We now have a key instantiated from the decrypted ticket.  We can
+	 * pass this to the application so that they can parse the ticket
+	 * content and we can use the session key it contains to derive the
+	 * keys we need.
+	 *
+	 * Note that we have to switch enctype at this point as the enctype of
+	 * the ticket doesn't necessarily match that of the transport.
+	 */
+	token = key->payload.data[0];
+	conn->security_level = token->rxgk->level;
+	conn->rxgk.start_time = __be64_to_cpu(rhdr->start_time);
+
+	gk = rxgk_generate_transport_key(conn, token->rxgk, sp->hdr.cksum, GFP_NOFS);
+	if (IS_ERR(gk)) {
+		ret = PTR_ERR(gk);
+		goto cant_get_token;
+	}
+
+	krb5 = gk->krb5;
+
+	trace_rxrpc_rx_response(conn, sp->hdr.serial, krb5->etype, sp->hdr.cksum,
+				resp_token_len);
+
+	/* Decrypt, parse and verify the authenticator. */
+	ret = rxgk_decrypt(krb5, gk->resp_enc, &auth, &auth_len, &ec);
+	if (ret < 0) {
+		rxrpc_abort_conn(conn, skb, RXGK_SEALEDINCON, ret,
+				 rxgk_abort_resp_auth_dec);
+		goto out_gk;
+	}
+
+	ret = rxgk_verify_authenticator(conn, krb5, skb, auth, auth_len);
+	if (ret < 0)
+		goto out_gk;
+
+	conn->key = key;
+	key = NULL;
+	ret = 0;
+out_gk:
+	rxgk_put(gk);
+out:
+	key_put(key);
+	_leave(" = %d", ret);
+	return ret;
+
+inconsistent:
+	ret = rxrpc_abort_conn(conn, skb, RXGK_INCONSISTENCY, -EPROTO,
+			       rxgk_abort_resp_xdr_align);
+	goto out;
+auth_too_short:
+	ret = rxrpc_abort_conn(conn, skb, RXGK_PACKETSHORT, -EPROTO,
+			       rxgk_abort_resp_short_auth);
+	goto out;
+short_packet:
+	ret = rxrpc_abort_conn(conn, skb, RXGK_PACKETSHORT, -EPROTO,
+			       rxgk_abort_resp_short_packet);
+	goto out;
+
+cant_get_token:
+	switch (ret) {
+	case -ENOMEM:
+		goto temporary_error;
+	case -EINVAL:
+		ret = rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EKEYREJECTED,
+				       rxgk_abort_resp_internal_error);
+		goto out;
+	case -ENOPKG:
+		ret = rxrpc_abort_conn(conn, skb, KRB5_PROG_KEYTYPE_NOSUPP,
+				       -EKEYREJECTED, rxgk_abort_resp_nopkg);
+		goto out;
+	}
+
+temporary_error:
+	/* Ignore the response packet if we got a temporary error such as
+	 * ENOMEM.  We just want to send the challenge again.  Note that we
+	 * also come out this way if the ticket decryption fails.
+	 */
+	goto out;
+}
+
+/*
+ * clear the connection security
+ */
+static void rxgk_clear(struct rxrpc_connection *conn)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(conn->rxgk.keys); i++)
+		rxgk_put(conn->rxgk.keys[i]);
+}
+
+/*
+ * Initialise the RxGK security service.
+ */
+static int rxgk_init(void)
+{
+	return 0;
+}
+
+/*
+ * Clean up the RxGK security service.
+ */
+static void rxgk_exit(void)
+{
+}
+
+/*
+ * RxRPC YFS GSSAPI-based security
+ */
+const struct rxrpc_security rxgk_yfs = {
+	.name				= "yfs-rxgk",
+	.security_index			= RXRPC_SECURITY_YFS_RXGK,
+	.no_key_abort			= RXGK_NOTAUTH,
+	.init				= rxgk_init,
+	.exit				= rxgk_exit,
+	.preparse_server_key		= rxgk_preparse_server_key,
+	.free_preparse_server_key	= rxgk_free_preparse_server_key,
+	.destroy_server_key		= rxgk_destroy_server_key,
+	.describe_server_key		= rxgk_describe_server_key,
+	.init_connection_security	= rxgk_init_connection_security,
+	.alloc_txbuf			= rxgk_alloc_txbuf,
+	.secure_packet			= rxgk_secure_packet,
+	.verify_packet			= rxgk_verify_packet,
+	.free_call_crypto		= rxgk_free_call_crypto,
+	.issue_challenge		= rxgk_issue_challenge,
+	.validate_challenge		= rxgk_validate_challenge,
+	.challenge_to_recvmsg		= rxgk_challenge_to_recvmsg,
+	.sendmsg_respond_to_challenge	= rxgk_sendmsg_respond_to_challenge,
+	.respond_to_challenge		= rxgk_respond_to_challenge_no_appdata,
+	.verify_response		= rxgk_verify_response,
+	.clear				= rxgk_clear,
+	.default_decode_ticket		= rxgk_yfs_decode_ticket,
+};
diff --git a/net/rxrpc/rxgk_app.c b/net/rxrpc/rxgk_app.c
new file mode 100644
index 000000000..200a30064
--- /dev/null
+++ b/net/rxrpc/rxgk_app.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Application-specific bits for GSSAPI-based RxRPC security
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/key-type.h>
+#include "ar-internal.h"
+#include "rxgk_common.h"
+
+/*
+ * Decode a default-style YFS ticket in a response and turn it into an
+ * rxrpc-type key.
+ *
+ * struct rxgk_key {
+ *	afs_uint32	enctype;
+ *	opaque		key<>;
+ * };
+ *
+ * struct RXGK_AuthName {
+ *	afs_int32	kind;
+ *	opaque		data<AUTHDATAMAX>;
+ *	opaque		display<AUTHPRINTABLEMAX>;
+ * };
+ *
+ * struct RXGK_Token {
+ *	rxgk_key		K0;
+ *	RXGK_Level		level;
+ *	rxgkTime		starttime;
+ *	afs_int32		lifetime;
+ *	afs_int32		bytelife;
+ *	rxgkTime		expirationtime;
+ *	struct RXGK_AuthName	identities<>;
+ * };
+ */
+int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb,
+			   void *buffer, unsigned int ticket_len,
+			   struct key **_key)
+{
+	struct rxrpc_key_token *token;
+	const struct cred *cred = current_cred(); // TODO - use socket creds
+	struct key *key;
+	size_t pre_ticket_len, payload_len;
+	unsigned int klen, enctype;
+	void *payload, *ticket;
+	__be32 *t, *p, *q, *tmp;
+	int ret;
+
+	_enter("");
+
+	if (ticket_len < 10 * sizeof(__be32))
+		return rxrpc_abort_conn(conn, skb, RXGK_INCONSISTENCY, -EPROTO,
+					rxgk_abort_resp_short_yfs_tkt);
+
+	/* Get the session key length */
+	tmp = buffer;
+	enctype = ntohl(tmp[0]);
+	klen = ntohl(tmp[1]);
+
+	if (klen > ticket_len - 10 * sizeof(__be32))
+		return rxrpc_abort_conn(conn, skb, RXGK_INCONSISTENCY, -EPROTO,
+					rxgk_abort_resp_short_yfs_key);
+
+	pre_ticket_len = ((5 + 14) * sizeof(__be32) +
+			  xdr_round_up(klen) +
+			  sizeof(__be32));
+	payload_len = pre_ticket_len + xdr_round_up(ticket_len);
+
+	payload = kzalloc(payload_len, GFP_NOFS);
+	if (!payload)
+		return -ENOMEM;
+
+	/* We need to fill out the XDR form for a key payload that we can pass
+	 * to add_key().  Start by copying in the ticket so that we can parse
+	 * it.
+	 */
+	ticket = payload + pre_ticket_len;
+	memcpy(ticket, buffer, ticket_len);
+
+	/* Fill out the form header. */
+	p = payload;
+	p[0] = htonl(0); /* Flags */
+	p[1] = htonl(1); /* len(cellname) */
+	p[2] = htonl(0x20000000); /* Cellname " " */
+	p[3] = htonl(1); /* #tokens */
+	p[4] = htonl(15 * sizeof(__be32) + xdr_round_up(klen) +
+		     xdr_round_up(ticket_len)); /* Token len */
+
+	/* Now fill in the body.  Most of this we can just scrape directly from
+	 * the ticket.
+	 */
+	t = ticket + sizeof(__be32) * 2 + xdr_round_up(klen);
+	q = payload + 5 * sizeof(__be32);
+	q[0]  = htonl(RXRPC_SECURITY_YFS_RXGK);
+	q[1]  = t[1];		/* begintime - msw */
+	q[2]  = t[2];		/* - lsw */
+	q[3]  = t[5];		/* endtime - msw */
+	q[4]  = t[6];		/* - lsw */
+	q[5]  = 0;		/* level - msw */
+	q[6]  = t[0];		/* - lsw */
+	q[7]  = 0;		/* lifetime - msw */
+	q[8]  = t[3];		/* - lsw */
+	q[9]  = 0;		/* bytelife - msw */
+	q[10] = t[4];		/* - lsw */
+	q[11] = 0;		/* enctype - msw */
+	q[12] = htonl(enctype);	/* - lsw */
+	q[13] = htonl(klen);	/* Key length */
+
+	q += 14;
+
+	memcpy(q, ticket + sizeof(__be32) * 2, klen);
+	q += xdr_round_up(klen) / 4;
+	q[0] = htonl(ticket_len);
+	q++;
+	if (WARN_ON((unsigned long)q != (unsigned long)ticket)) {
+		ret = -EIO;
+		goto error;
+	}
+
+	/* Ticket appended above. */
+	q += xdr_round_up(ticket_len) / 4;
+	if (WARN_ON((unsigned long)q - (unsigned long)payload != payload_len)) {
+		ret = -EIO;
+		goto error;
+	}
+
+	/* Now turn that into a key. */
+	key = key_alloc(&key_type_rxrpc, "x",
+			GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, // TODO: Use socket owner
+			KEY_USR_VIEW,
+			KEY_ALLOC_NOT_IN_QUOTA, NULL);
+	if (IS_ERR(key)) {
+		_leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+		ret = PTR_ERR(key);
+		goto error;
+	}
+
+	_debug("key %d", key_serial(key));
+
+	ret = key_instantiate_and_link(key, payload, payload_len, NULL, NULL);
+	if (ret < 0)
+		goto error_key;
+
+	token = key->payload.data[0];
+	token->no_leak_key = true;
+	*_key = key;
+	key = NULL;
+	ret = 0;
+	goto error;
+
+error_key:
+	key_put(key);
+error:
+	kfree_sensitive(payload);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Extract the token and set up a session key from the details.
+ *
+ * struct RXGK_TokenContainer {
+ *	afs_int32	kvno;
+ *	afs_int32	enctype;
+ *	opaque		encrypted_token<>;
+ * };
+ *
+ * [tools.ietf.org/html/draft-wilkinson-afs3-rxgk-afs-08 sec 6.1]
+ */
+int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb,
+		       void *token, unsigned int token_len,
+		       struct key **_key)
+{
+	const struct krb5_enctype *krb5;
+	const struct krb5_buffer *server_secret;
+	struct crypto_aead *token_enc = NULL;
+	struct key *server_key;
+	unsigned int ticket_len;
+	void *ticket;
+	u32 kvno, enctype;
+	int ret, ec = 0;
+
+	struct {
+		__be32 kvno;
+		__be32 enctype;
+		__be32 token_len;
+	} *container;
+
+	if (token_len < sizeof(*container))
+		goto short_packet;
+
+	/* Decode the RXGK_TokenContainer object.  This tells us which server
+	 * key we should be using.  We can then fetch the key, get the secret
+	 * and set up the crypto to extract the token.
+	 */
+	container = token;
+	token += sizeof(*container);
+
+	kvno		= ntohl(container->kvno);
+	enctype		= ntohl(container->enctype);
+	ticket_len	= ntohl(container->token_len);
+
+	if (ticket_len > xdr_round_down(token_len - sizeof(*container)))
+		goto short_packet;
+
+	_debug("KVNO %u", kvno);
+	_debug("ENC  %u", enctype);
+	_debug("TLEN %u", ticket_len);
+
+	server_key = rxrpc_look_up_server_security(conn, skb, kvno, enctype);
+	if (IS_ERR(server_key))
+		goto cant_get_server_key;
+
+	down_read(&server_key->sem);
+	server_secret = (const void *)&server_key->payload.data[2];
+	ret = rxgk_set_up_token_cipher(server_secret, &token_enc, enctype, &krb5, GFP_NOFS);
+	up_read(&server_key->sem);
+	key_put(server_key);
+	if (ret < 0)
+		goto cant_get_token;
+
+	/* We can now decrypt and parse the token/ticket.  This allows us to
+	 * gain access to K0, from which we can derive the transport key and
+	 * thence decode the authenticator.
+	 */
+	ticket = token;
+	ret = rxgk_decrypt(krb5, token_enc, &ticket, &ticket_len, &ec);
+	crypto_free_aead(token_enc);
+	token_enc = NULL;
+	if (ret < 0) {
+		if (ret != -ENOMEM)
+			return rxrpc_abort_conn(conn, skb, ec, ret,
+						rxgk_abort_resp_tok_dec);
+		return ret;
+	}
+
+	ret = conn->security->default_decode_ticket(conn, skb, ticket,
+						    ticket_len, _key);
+	if (ret < 0)
+		goto cant_get_token;
+
+	_leave(" = 0");
+	return ret;
+
+cant_get_server_key:
+	ret = PTR_ERR(server_key);
+	switch (ret) {
+	case -ENOMEM:
+		goto temporary_error;
+	case -ENOKEY:
+	case -EKEYREJECTED:
+	case -EKEYEXPIRED:
+	case -EKEYREVOKED:
+	case -EPERM:
+		return rxrpc_abort_conn(conn, skb, RXGK_BADKEYNO, -EKEYREJECTED,
+					rxgk_abort_resp_tok_nokey);
+	default:
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EKEYREJECTED,
+					rxgk_abort_resp_tok_keyerr);
+	}
+
+cant_get_token:
+	switch (ret) {
+	case -ENOMEM:
+		goto temporary_error;
+	case -EINVAL:
+		return rxrpc_abort_conn(conn, skb, RXGK_NOTAUTH, -EKEYREJECTED,
+					rxgk_abort_resp_tok_internal_error);
+	case -ENOPKG:
+		return rxrpc_abort_conn(conn, skb, KRB5_PROG_KEYTYPE_NOSUPP,
+					-EKEYREJECTED, rxgk_abort_resp_tok_nopkg);
+	}
+
+temporary_error:
+	/* Ignore the response packet if we got a temporary error such as
+	 * ENOMEM.  We just want to send the challenge again.  Note that we
+	 * also come out this way if the ticket decryption fails.
+	 */
+	return ret;
+
+short_packet:
+	return rxrpc_abort_conn(conn, skb, RXGK_PACKETSHORT, -EPROTO,
+				rxgk_abort_resp_tok_short);
+}
diff --git a/net/rxrpc/rxgk_common.h b/net/rxrpc/rxgk_common.h
new file mode 100644
index 000000000..3deed5863
--- /dev/null
+++ b/net/rxrpc/rxgk_common.h
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Common bits for GSSAPI-based RxRPC security.
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <crypto/krb5.h>
+#include <crypto/skcipher.h>
+#include <crypto/hash.h>
+
+/*
+ * Per-key number context.  This is replaced when the connection is rekeyed.
+ */
+struct rxgk_context {
+	refcount_t		usage;
+	unsigned int		key_number;	/* Rekeying number (goes in the rx header) */
+	unsigned long		flags;
+#define RXGK_TK_NEEDS_REKEY	0		/* Set if this needs rekeying */
+	unsigned long		expiry;		/* Expiration time of this key */
+	long long		bytes_remaining; /* Remaining Tx lifetime of this key */
+	const struct krb5_enctype *krb5;	/* RxGK encryption type */
+	const struct rxgk_key	*key;
+
+	/* We need up to 7 keys derived from the transport key, but we don't
+	 * actually need the transport key.  Each key is derived by
+	 * DK(TK,constant).
+	 */
+	struct crypto_aead	*tx_enc;	/* Transmission key */
+	struct crypto_aead	*rx_enc;	/* Reception key */
+	struct crypto_shash	*tx_Kc;		/* Transmission checksum key */
+	struct crypto_shash	*rx_Kc;		/* Reception checksum key */
+	struct crypto_aead	*resp_enc;	/* Response packet enc key */
+};
+
+#define xdr_round_up(x) (round_up((x), sizeof(__be32)))
+#define xdr_round_down(x) (round_down((x), sizeof(__be32)))
+#define xdr_object_len(x) (4 + xdr_round_up(x))
+
+/*
+ * rxgk_app.c
+ */
+int rxgk_yfs_decode_ticket(struct rxrpc_connection *conn, struct sk_buff *skb,
+			   void *ticket, unsigned int ticket_len,
+			   struct key **_key);
+int rxgk_extract_token(struct rxrpc_connection *conn, struct sk_buff *skb,
+		       void *token, unsigned int token_len,
+		       struct key **_key);
+
+/*
+ * rxgk_kdf.c
+ */
+void rxgk_put(struct rxgk_context *gk);
+struct rxgk_context *rxgk_generate_transport_key(struct rxrpc_connection *conn,
+						 const struct rxgk_key *key,
+						 unsigned int key_number,
+						 gfp_t gfp);
+int rxgk_set_up_token_cipher(const struct krb5_buffer *server_key,
+			     struct crypto_aead **token_key,
+			     unsigned int enctype,
+			     const struct krb5_enctype **_krb5,
+			     gfp_t gfp);
+
+/*
+ * Apply decryption and checksumming functions a flat data buffer.  The data
+ * point and length are updated to reflect the actual content of the encrypted
+ * region.
+ */
+static inline int rxgk_decrypt(const struct krb5_enctype *krb5,
+			       struct crypto_aead *aead,
+			       void **_data, unsigned int *_len,
+			       int *_error_code)
+{
+	struct scatterlist sg[1];
+	size_t offset = 0, len = *_len;
+	int ret;
+
+	sg_init_one(sg, *_data, len);
+
+	ret = crypto_krb5_decrypt(krb5, aead, sg, 1, &offset, &len);
+	switch (ret) {
+	case 0:
+		if (offset & 3) {
+			*_error_code = RXGK_INCONSISTENCY;
+			ret = -EPROTO;
+			break;
+		}
+		*_data += offset;
+		*_len = len;
+		break;
+	case -EBADMSG: /* Checksum mismatch. */
+	case -EPROTO:
+		*_error_code = RXGK_SEALEDINCON;
+		break;
+	case -EMSGSIZE:
+		*_error_code = RXGK_PACKETSHORT;
+		break;
+	case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */
+	default:
+		*_error_code = RXGK_INCONSISTENCY;
+		break;
+	}
+
+	return ret;
+}
+
+/*
+ * Check the MIC on a flat buffer.  The data pointer and length are updated to
+ * reflect the actual content of the secure region.
+ */
+static inline
+int rxgk_verify_mic(const struct krb5_enctype *krb5,
+		    struct crypto_shash *shash,
+		    const struct krb5_buffer *metadata,
+		    void **_data, unsigned int *_len,
+		    u32 *_error_code)
+{
+	struct scatterlist sg[1];
+	size_t offset = 0, len = *_len;
+	int ret;
+
+	sg_init_one(sg, *_data, len);
+
+	ret = crypto_krb5_verify_mic(krb5, shash, metadata, sg, 1, &offset, &len);
+	switch (ret) {
+	case 0:
+		*_data += offset;
+		*_len = len;
+		break;
+	case -EBADMSG: /* Checksum mismatch */
+	case -EPROTO:
+		*_error_code = RXGK_SEALEDINCON;
+		break;
+	case -EMSGSIZE:
+		*_error_code = RXGK_PACKETSHORT;
+		break;
+	case -ENOPKG: /* Would prefer RXGK_BADETYPE, but not available for YFS. */
+	default:
+		*_error_code = RXGK_INCONSISTENCY;
+		break;
+	}
+
+	return ret;
+}
diff --git a/net/rxrpc/rxgk_kdf.c b/net/rxrpc/rxgk_kdf.c
new file mode 100644
index 000000000..677981d1a
--- /dev/null
+++ b/net/rxrpc/rxgk_kdf.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxGK transport key derivation.
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/key-type.h>
+#include <linux/slab.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+#include "rxgk_common.h"
+
+#define round16(x) (((x) + 15) & ~15)
+
+/*
+ * Constants used to derive the keys and hmacs actually used for doing stuff.
+ */
+#define RXGK_CLIENT_ENC_PACKET		1026U // 0x402
+#define RXGK_CLIENT_MIC_PACKET          1027U // 0x403
+#define RXGK_SERVER_ENC_PACKET          1028U // 0x404
+#define RXGK_SERVER_MIC_PACKET          1029U // 0x405
+#define RXGK_CLIENT_ENC_RESPONSE        1030U // 0x406
+#define RXGK_SERVER_ENC_TOKEN           1036U // 0x40c
+
+static void rxgk_free(struct rxgk_context *gk)
+{
+	if (gk->tx_Kc)
+		crypto_free_shash(gk->tx_Kc);
+	if (gk->rx_Kc)
+		crypto_free_shash(gk->rx_Kc);
+	if (gk->tx_enc)
+		crypto_free_aead(gk->tx_enc);
+	if (gk->rx_enc)
+		crypto_free_aead(gk->rx_enc);
+	if (gk->resp_enc)
+		crypto_free_aead(gk->resp_enc);
+	kfree(gk);
+}
+
+void rxgk_put(struct rxgk_context *gk)
+{
+	if (gk && refcount_dec_and_test(&gk->usage))
+		rxgk_free(gk);
+}
+
+/*
+ * Transport key derivation function.
+ *
+ *      TK = random-to-key(PRF+(K0, L,
+ *                         epoch || cid || start_time || key_number))
+ *      [tools.ietf.org/html/draft-wilkinson-afs3-rxgk-11 sec 8.3]
+ */
+static int rxgk_derive_transport_key(struct rxrpc_connection *conn,
+				     struct rxgk_context *gk,
+				     const struct rxgk_key *rxgk,
+				     struct krb5_buffer *TK,
+				     gfp_t gfp)
+{
+	const struct krb5_enctype *krb5 = gk->krb5;
+	struct krb5_buffer conn_info;
+	unsigned int L = krb5->key_bytes;
+	__be32 *info;
+	u8 *buffer;
+	int ret;
+
+	_enter("");
+
+	conn_info.len = sizeof(__be32) * 5;
+
+	buffer = kzalloc(round16(conn_info.len), gfp);
+	if (!buffer)
+		return -ENOMEM;
+
+	conn_info.data = buffer;
+
+	info = (__be32 *)conn_info.data;
+	info[0] = htonl(conn->proto.epoch);
+	info[1] = htonl(conn->proto.cid);
+	info[2] = htonl(conn->rxgk.start_time >> 32);
+	info[3] = htonl(conn->rxgk.start_time >>  0);
+	info[4] = htonl(gk->key_number);
+
+	ret = crypto_krb5_calc_PRFplus(krb5, &rxgk->key, L, &conn_info, TK, gfp);
+	kfree_sensitive(buffer);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Set up the ciphers for the usage keys.
+ */
+static int rxgk_set_up_ciphers(struct rxrpc_connection *conn,
+			       struct rxgk_context *gk,
+			       const struct rxgk_key *rxgk,
+			       gfp_t gfp)
+{
+	const struct krb5_enctype *krb5 = gk->krb5;
+	struct crypto_shash *shash;
+	struct crypto_aead *aead;
+	struct krb5_buffer TK;
+	bool service = rxrpc_conn_is_service(conn);
+	int ret;
+	u8 *buffer;
+
+	buffer = kzalloc(krb5->key_bytes, gfp);
+	if (!buffer)
+		return -ENOMEM;
+
+	TK.len = krb5->key_bytes;
+	TK.data = buffer;
+
+	ret = rxgk_derive_transport_key(conn, gk, rxgk, &TK, gfp);
+	if (ret < 0)
+		goto out;
+
+	aead = crypto_krb5_prepare_encryption(krb5, &TK, RXGK_CLIENT_ENC_RESPONSE, gfp);
+	if (IS_ERR(aead))
+		goto aead_error;
+	gk->resp_enc = aead;
+
+	if (crypto_aead_blocksize(gk->resp_enc) != krb5->block_len ||
+	    crypto_aead_authsize(gk->resp_enc) != krb5->cksum_len) {
+		pr_notice("algo inconsistent with krb5 table %u!=%u or %u!=%u\n",
+			  crypto_aead_blocksize(gk->resp_enc), krb5->block_len,
+			  crypto_aead_authsize(gk->resp_enc), krb5->cksum_len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (service) {
+		switch (conn->security_level) {
+		case RXRPC_SECURITY_AUTH:
+			shash = crypto_krb5_prepare_checksum(
+				krb5, &TK, RXGK_SERVER_MIC_PACKET, gfp);
+			if (IS_ERR(shash))
+				goto hash_error;
+			gk->tx_Kc = shash;
+			shash = crypto_krb5_prepare_checksum(
+				krb5, &TK, RXGK_CLIENT_MIC_PACKET, gfp);
+			if (IS_ERR(shash))
+				goto hash_error;
+			gk->rx_Kc = shash;
+			break;
+		case RXRPC_SECURITY_ENCRYPT:
+			aead = crypto_krb5_prepare_encryption(
+				krb5, &TK, RXGK_SERVER_ENC_PACKET, gfp);
+			if (IS_ERR(aead))
+				goto aead_error;
+			gk->tx_enc = aead;
+			aead = crypto_krb5_prepare_encryption(
+				krb5, &TK, RXGK_CLIENT_ENC_PACKET, gfp);
+			if (IS_ERR(aead))
+				goto aead_error;
+			gk->rx_enc = aead;
+			break;
+		}
+	} else {
+		switch (conn->security_level) {
+		case RXRPC_SECURITY_AUTH:
+			shash = crypto_krb5_prepare_checksum(
+				krb5, &TK, RXGK_CLIENT_MIC_PACKET, gfp);
+			if (IS_ERR(shash))
+				goto hash_error;
+			gk->tx_Kc = shash;
+			shash = crypto_krb5_prepare_checksum(
+				krb5, &TK, RXGK_SERVER_MIC_PACKET, gfp);
+			if (IS_ERR(shash))
+				goto hash_error;
+			gk->rx_Kc = shash;
+			break;
+		case RXRPC_SECURITY_ENCRYPT:
+			aead = crypto_krb5_prepare_encryption(
+				krb5, &TK, RXGK_CLIENT_ENC_PACKET, gfp);
+			if (IS_ERR(aead))
+				goto aead_error;
+			gk->tx_enc = aead;
+			aead = crypto_krb5_prepare_encryption(
+				krb5, &TK, RXGK_SERVER_ENC_PACKET, gfp);
+			if (IS_ERR(aead))
+				goto aead_error;
+			gk->rx_enc = aead;
+			break;
+		}
+	}
+
+	ret = 0;
+out:
+	kfree_sensitive(buffer);
+	return ret;
+aead_error:
+	ret = PTR_ERR(aead);
+	goto out;
+hash_error:
+	ret = PTR_ERR(shash);
+	goto out;
+}
+
+/*
+ * Derive a transport key for a connection and then derive a bunch of usage
+ * keys from it and set up ciphers using them.
+ */
+struct rxgk_context *rxgk_generate_transport_key(struct rxrpc_connection *conn,
+						 const struct rxgk_key *key,
+						 unsigned int key_number,
+						 gfp_t gfp)
+{
+	struct rxgk_context *gk;
+	unsigned long lifetime;
+	int ret = -ENOPKG;
+
+	_enter("");
+
+	gk = kzalloc_obj(*gk);
+	if (!gk)
+		return ERR_PTR(-ENOMEM);
+	refcount_set(&gk->usage, 1);
+	gk->key		= key;
+	gk->key_number	= key_number;
+
+	gk->krb5 = crypto_krb5_find_enctype(key->enctype);
+	if (!gk->krb5)
+		goto err_tk;
+
+	ret = rxgk_set_up_ciphers(conn, gk, key, gfp);
+	if (ret)
+		goto err_tk;
+
+	/* Set the remaining number of bytes encrypted with this key that may
+	 * be transmitted before rekeying.  Note that the spec has been
+	 * interpreted differently on this point...
+	 */
+	switch (key->bytelife) {
+	case 0:
+	case 63:
+		gk->bytes_remaining = LLONG_MAX;
+		break;
+	case 1 ... 62:
+		gk->bytes_remaining = 1LL << key->bytelife;
+		break;
+	default:
+		gk->bytes_remaining = key->bytelife;
+		break;
+	}
+
+	/* Set the time after which rekeying must occur */
+	if (key->lifetime) {
+		lifetime = min_t(u64, key->lifetime, INT_MAX / HZ);
+		lifetime *= HZ;
+	} else {
+		lifetime = MAX_JIFFY_OFFSET;
+	}
+	gk->expiry = jiffies + lifetime;
+	return gk;
+
+err_tk:
+	rxgk_put(gk);
+	_leave(" = %d", ret);
+	return ERR_PTR(ret);
+}
+
+/*
+ * Use the server secret key to set up the ciphers that will be used to extract
+ * the token from a response packet.
+ */
+int rxgk_set_up_token_cipher(const struct krb5_buffer *server_key,
+			     struct crypto_aead **token_aead,
+			     unsigned int enctype,
+			     const struct krb5_enctype **_krb5,
+			     gfp_t gfp)
+{
+	const struct krb5_enctype *krb5;
+	struct crypto_aead *aead;
+
+	krb5 = crypto_krb5_find_enctype(enctype);
+	if (!krb5)
+		return -ENOPKG;
+
+	aead = crypto_krb5_prepare_encryption(krb5, server_key, RXGK_SERVER_ENC_TOKEN, gfp);
+	if (IS_ERR(aead))
+		return PTR_ERR(aead);
+
+	*_krb5 = krb5;
+	*token_aead = aead;
+	return 0;
+}
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
new file mode 100644
index 000000000..ca9f0e82c
--- /dev/null
+++ b/net/rxrpc/rxkad.c
@@ -0,0 +1,1141 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Kerberos-based RxRPC security
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/des.h>
+#include <kunit/visibility.h>
+#include <linux/export.h>
+#include <linux/fips.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/key-type.h>
+#include <linux/unaligned.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+
+#define RXKAD_VERSION			2
+#define MAXKRB5TICKETLEN		1024
+#define RXKAD_TKT_TYPE_KERBEROS_V5	256
+#define ANAME_SZ			40	/* size of authentication name */
+#define INST_SZ				40	/* size of principal's instance */
+#define REALM_SZ			40	/* size of principal's auth domain */
+#define SNAME_SZ			40	/* size of service name */
+#define RXKAD_ALIGN			8
+
+static const u8 zero_iv[FCRYPT_BSIZE];
+
+struct rxkad_level1_hdr {
+	__be32	data_size;	/* true data size (excluding padding) */
+};
+
+struct rxkad_level2_hdr {
+	__be32	data_size;	/* true data size (excluding padding) */
+	__be32	checksum;	/* decrypted data checksum */
+};
+
+static void rxkad_prime_packet_security(struct rxrpc_connection *conn,
+					const struct fcrypt_key *cipher);
+
+/*
+ * Parse the information from a server key
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxkad_preparse_server_key(struct key_preparsed_payload *prep)
+{
+	struct des_ctx *des_key;
+	int err;
+
+	if (prep->datalen != 8)
+		return -EINVAL;
+
+	memcpy(&prep->payload.data[2], prep->data, 8);
+
+	des_key = kmalloc_obj(*des_key);
+	if (!des_key) {
+		_leave(" = -ENOMEM");
+		return -ENOMEM;
+	}
+
+	err = des_expand_key(des_key, prep->data, 8);
+	if (err) {
+		kfree_sensitive(des_key);
+		_leave(" = %d", err);
+		return err;
+	}
+
+	prep->payload.data[0] = des_key;
+	_leave(" = 0");
+	return 0;
+}
+
+static void rxkad_free_preparse_server_key(struct key_preparsed_payload *prep)
+{
+	kfree_sensitive(prep->payload.data[0]);
+}
+
+static void rxkad_destroy_server_key(struct key *key)
+{
+	kfree_sensitive(key->payload.data[0]);
+	key->payload.data[0] = NULL;
+}
+
+/*
+ * initialise connection security
+ */
+static int rxkad_init_connection_security(struct rxrpc_connection *conn,
+					  struct rxrpc_key_token *token)
+{
+	struct fcrypt_key *ci;
+	int ret;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(conn->key));
+
+	conn->security_ix = token->security_index;
+
+	ci = kmalloc_obj(*ci);
+	if (!ci) {
+		ret = -ENOMEM;
+		goto error;
+	}
+	fcrypt_preparekey(ci, token->kad->session_key);
+
+	switch (conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+	case RXRPC_SECURITY_AUTH:
+	case RXRPC_SECURITY_ENCRYPT:
+		break;
+	default:
+		ret = -EKEYREJECTED;
+		goto error_ci;
+	}
+
+	rxkad_prime_packet_security(conn, ci);
+
+	conn->rxkad.cipher = ci;
+	return 0;
+
+error_ci:
+	kfree_sensitive(ci);
+error:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Work out how much data we can put in a packet.
+ */
+static struct rxrpc_txbuf *rxkad_alloc_txbuf(struct rxrpc_call *call, size_t remain, gfp_t gfp)
+{
+	struct rxrpc_txbuf *txb;
+	size_t shdr, alloc, limit, part;
+
+	remain = umin(remain, 65535 - sizeof(struct rxrpc_wire_header));
+
+	switch (call->conn->security_level) {
+	default:
+		alloc = umin(remain, RXRPC_JUMBO_DATALEN);
+		return rxrpc_alloc_data_txbuf(call, alloc, 1, gfp);
+	case RXRPC_SECURITY_AUTH:
+		shdr = sizeof(struct rxkad_level1_hdr);
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		shdr = sizeof(struct rxkad_level2_hdr);
+		break;
+	}
+
+	limit = round_down(RXRPC_JUMBO_DATALEN, RXKAD_ALIGN) - shdr;
+	if (remain < limit) {
+		part = remain;
+		alloc = round_up(shdr + part, RXKAD_ALIGN);
+	} else {
+		part = limit;
+		alloc = RXRPC_JUMBO_DATALEN;
+	}
+
+	txb = rxrpc_alloc_data_txbuf(call, alloc, RXKAD_ALIGN, gfp);
+	if (!txb)
+		return NULL;
+
+	txb->crypto_header	= 0;
+	txb->sec_header		= shdr;
+	txb->offset		+= shdr;
+	txb->space		= part;
+	return txb;
+}
+
+/*
+ * prime the encryption state with the invariant parts of a connection's
+ * description
+ */
+static void rxkad_prime_packet_security(struct rxrpc_connection *conn,
+					const struct fcrypt_key *cipher)
+{
+	struct rxrpc_key_token *token;
+	__be32 tmpbuf[4];
+
+	_enter("");
+
+	if (!conn->key)
+		return;
+	token = conn->key->payload.data[0];
+
+	tmpbuf[0] = htonl(conn->proto.epoch);
+	tmpbuf[1] = htonl(conn->proto.cid);
+	tmpbuf[2] = 0;
+	tmpbuf[3] = htonl(conn->security_ix);
+
+	static_assert(sizeof(tmpbuf) % FCRYPT_BSIZE == 0);
+	fcrypt_pcbc_encrypt(cipher, /* iv= */ token->kad->session_key, tmpbuf,
+			    tmpbuf, sizeof(tmpbuf) / FCRYPT_BSIZE);
+	memcpy(&conn->rxkad.csum_iv, &tmpbuf[2], sizeof(conn->rxkad.csum_iv));
+	_leave("");
+}
+
+/*
+ * Clean up the crypto on a call.
+ */
+static void rxkad_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+/*
+ * partially encrypt a packet (level 1 security)
+ */
+static void rxkad_secure_packet_auth(const struct rxrpc_call *call,
+				     struct rxrpc_txbuf *txb)
+{
+	struct rxkad_level1_hdr *hdr = txb->data;
+	size_t pad;
+	u16 check;
+
+	_enter("");
+
+	check = txb->seq ^ call->call_id;
+	hdr->data_size = htonl((u32)check << 16 | txb->len);
+
+	txb->pkt_len = sizeof(struct rxkad_level1_hdr) + txb->len;
+	pad = txb->pkt_len;
+	pad = RXKAD_ALIGN - pad;
+	pad &= RXKAD_ALIGN - 1;
+	if (pad) {
+		memset(txb->data + txb->offset, 0, pad);
+		txb->pkt_len += pad;
+	}
+
+	/* start the encryption afresh */
+	fcrypt_pcbc_encrypt(call->conn->rxkad.cipher, zero_iv, hdr, hdr, 1);
+	_leave("");
+}
+
+/*
+ * wholly encrypt a packet (level 2 security)
+ */
+static void rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
+					struct rxrpc_txbuf *txb)
+{
+	const struct rxrpc_key_token *token;
+	struct rxkad_level2_hdr *rxkhdr = txb->data;
+	size_t content, pad;
+	u16 check;
+
+	_enter("");
+
+	check = txb->seq ^ call->call_id;
+
+	rxkhdr->data_size = htonl(txb->len | (u32)check << 16);
+	rxkhdr->checksum = 0;
+
+	content = sizeof(struct rxkad_level2_hdr) + txb->len;
+	static_assert(RXKAD_ALIGN == FCRYPT_BSIZE);
+	txb->pkt_len = round_up(content, RXKAD_ALIGN);
+	pad = txb->pkt_len - content;
+	if (pad)
+		memset(txb->data + txb->offset, 0, pad);
+	/* Now txb->pkt_len % FCRYPT_BSIZE == 0. */
+
+	/* encrypt from the session key */
+	token = call->conn->key->payload.data[0];
+	fcrypt_pcbc_encrypt(call->conn->rxkad.cipher, token->kad->session_key,
+			    rxkhdr, rxkhdr, txb->pkt_len / FCRYPT_BSIZE);
+	_leave("");
+}
+
+/*
+ * checksum an RxRPC packet header
+ */
+static int rxkad_secure_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb)
+{
+	union {
+		__be32 buf[2];
+	} crypto __aligned(8);
+	u32 x, y = 0;
+	int ret;
+
+	_enter("{%d{%x}},{#%u},%u,",
+	       call->debug_id, key_serial(call->conn->key),
+	       txb->seq, txb->len);
+
+	if (!call->conn->rxkad.cipher)
+		return 0;
+
+	ret = key_validate(call->conn->key);
+	if (ret < 0)
+		return ret;
+
+	/* calculate the security checksum */
+	x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
+	x |= txb->seq & 0x3fffffff;
+	crypto.buf[0] = htonl(call->call_id);
+	crypto.buf[1] = htonl(x);
+
+	/* continue encrypting from where we left off */
+	fcrypt_pcbc_encrypt(call->conn->rxkad.cipher,
+			    call->conn->rxkad.csum_iv.x, crypto.buf, crypto.buf,
+			    1);
+
+	y = ntohl(crypto.buf[1]);
+	y = (y >> 16) & 0xffff;
+	if (y == 0)
+		y = 1; /* zero checksums are not permitted */
+	txb->cksum = htons(y);
+
+	switch (call->conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		txb->pkt_len = txb->len;
+		ret = 0;
+		break;
+	case RXRPC_SECURITY_AUTH:
+		rxkad_secure_packet_auth(call, txb);
+		if (txb->alloc_size == RXRPC_JUMBO_DATALEN)
+			txb->jumboable = true;
+		ret = 0;
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		rxkad_secure_packet_encrypt(call, txb);
+		if (txb->alloc_size == RXRPC_JUMBO_DATALEN)
+			txb->jumboable = true;
+		ret = 0;
+		break;
+	default:
+		ret = -EPERM;
+		break;
+	}
+
+	/* Clear excess space in the packet */
+	if (txb->pkt_len < txb->alloc_size) {
+		size_t gap = txb->alloc_size - txb->pkt_len;
+		void *p = txb->data;
+
+		memset(p + txb->pkt_len, 0, gap);
+	}
+
+	_leave(" = %d [set %x]", ret, y);
+	return ret;
+}
+
+/*
+ * decrypt partial encryption on a packet (level 1 security)
+ */
+static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
+				 rxrpc_seq_t seq)
+{
+	struct rxkad_level1_hdr *sechdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	void *data = call->rx_dec_buffer;
+	u32 len = sp->len, data_size, buf;
+	u16 check;
+
+	_enter("");
+
+	if (len < 8)
+		return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON,
+					  rxkad_abort_1_short_header);
+
+	/* Decrypt the first 8-byte block of the packet, using the zero IV. */
+	fcrypt_pcbc_decrypt(call->conn->rxkad.cipher, zero_iv, data, data, 1);
+
+	/* Extract the decrypted packet length */
+	sechdr = data;
+	call->rx_dec_offset = sizeof(*sechdr);
+	len -= sizeof(*sechdr);
+
+	buf = ntohl(sechdr->data_size);
+	data_size = buf & 0xffff;
+
+	check = buf >> 16;
+	check ^= seq ^ call->call_id;
+	check &= 0xffff;
+	if (check != 0)
+		return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON,
+					  rxkad_abort_1_short_check);
+	if (data_size > len)
+		return rxrpc_abort_eproto(call, skb, RXKADDATALEN,
+					  rxkad_abort_1_short_data);
+	call->rx_dec_len = data_size;
+
+	_leave(" = 0 [dlen=%x]", data_size);
+	return 0;
+}
+
+/*
+ * wholly decrypt a packet (level 2 security)
+ */
+static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
+				 rxrpc_seq_t seq)
+{
+	const struct rxrpc_key_token *token;
+	struct rxkad_level2_hdr *sechdr;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	void *data = call->rx_dec_buffer;
+	u32 len = sp->len, data_size, buf;
+	u16 check;
+
+	_enter(",{%d}", len);
+
+	if (len < 8)
+		return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON,
+					  rxkad_abort_2_short_header);
+
+	/* Don't let the crypto algo see a misaligned length. */
+	len = round_down(len, 8);
+
+	/* decrypt from the session key */
+	token = call->conn->key->payload.data[0];
+	fcrypt_pcbc_decrypt(call->conn->rxkad.cipher, token->kad->session_key,
+			    data, data, len / FCRYPT_BSIZE);
+
+	/* Extract the decrypted packet length */
+	sechdr = data;
+	call->rx_dec_offset = sizeof(*sechdr);
+	len -= sizeof(*sechdr);
+
+	buf = ntohl(sechdr->data_size);
+	data_size = buf & 0xffff;
+
+	check = buf >> 16;
+	check ^= seq ^ call->call_id;
+	check &= 0xffff;
+	if (check != 0)
+		return rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON,
+					  rxkad_abort_2_short_check);
+
+	if (data_size > len)
+		return rxrpc_abort_eproto(call, skb, RXKADDATALEN,
+					  rxkad_abort_2_short_data);
+
+	call->rx_dec_len = data_size;
+	_leave(" = 0 [dlen=%x]", data_size);
+	return 0;
+}
+
+/*
+ * Verify the security on a received (sub)packet.  If the packet needs
+ * modifying (e.g. decrypting), it must be copied.
+ */
+static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	union {
+		__be32 buf[2];
+	} crypto __aligned(8);
+	rxrpc_seq_t seq = sp->hdr.seq;
+	int ret;
+	u16 cksum;
+	u32 x, y;
+
+	_enter("{%d{%x}},{#%u}",
+	       call->debug_id, key_serial(call->conn->key), seq);
+
+	if (!call->conn->rxkad.cipher)
+		return 0;
+
+	/* validate the security checksum */
+	x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
+	x |= seq & 0x3fffffff;
+	crypto.buf[0] = htonl(call->call_id);
+	crypto.buf[1] = htonl(x);
+
+	/* continue encrypting from where we left off */
+	fcrypt_pcbc_encrypt(call->conn->rxkad.cipher,
+			    call->conn->rxkad.csum_iv.x, crypto.buf, crypto.buf,
+			    1);
+
+	y = ntohl(crypto.buf[1]);
+	cksum = (y >> 16) & 0xffff;
+	if (cksum == 0)
+		cksum = 1; /* zero checksums are not permitted */
+
+	if (cksum != sp->hdr.cksum) {
+		ret = rxrpc_abort_eproto(call, skb, RXKADSEALEDINCON,
+					 rxkad_abort_bad_checksum);
+		goto out;
+	}
+
+	switch (call->conn->security_level) {
+	case RXRPC_SECURITY_PLAIN:
+		ret = 0;
+		break;
+	case RXRPC_SECURITY_AUTH:
+		ret = rxkad_verify_packet_1(call, skb, seq);
+		break;
+	case RXRPC_SECURITY_ENCRYPT:
+		ret = rxkad_verify_packet_2(call, skb, seq);
+		break;
+	default:
+		ret = -ENOANO;
+		break;
+	}
+out:
+	return ret;
+}
+
+/*
+ * issue a challenge
+ */
+static int rxkad_issue_challenge(struct rxrpc_connection *conn)
+{
+	struct rxkad_challenge challenge;
+	struct rxrpc_wire_header whdr;
+	struct msghdr msg;
+	struct kvec iov[2];
+	size_t len;
+	u32 serial;
+	int ret;
+
+	_enter("{%d}", conn->debug_id);
+
+	get_random_bytes(&conn->rxkad.nonce, sizeof(conn->rxkad.nonce));
+
+	challenge.version	= htonl(2);
+	challenge.nonce		= htonl(conn->rxkad.nonce);
+	challenge.min_level	= htonl(0);
+	challenge.__padding	= 0;
+
+	msg.msg_name	= &conn->peer->srx.transport;
+	msg.msg_namelen	= conn->peer->srx.transport_len;
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	whdr.epoch	= htonl(conn->proto.epoch);
+	whdr.cid	= htonl(conn->proto.cid);
+	whdr.callNumber	= 0;
+	whdr.seq	= 0;
+	whdr.type	= RXRPC_PACKET_TYPE_CHALLENGE;
+	whdr.flags	= conn->out_clientflag;
+	whdr.userStatus	= 0;
+	whdr.securityIndex = conn->security_ix;
+	whdr._rsvd	= 0;
+	whdr.serviceId	= htons(conn->service_id);
+
+	iov[0].iov_base	= &whdr;
+	iov[0].iov_len	= sizeof(whdr);
+	iov[1].iov_base	= &challenge;
+	iov[1].iov_len	= sizeof(challenge);
+
+	len = iov[0].iov_len + iov[1].iov_len;
+
+	serial = rxrpc_get_next_serial(conn);
+	whdr.serial = htonl(serial);
+
+	trace_rxrpc_tx_challenge(conn, serial, 0, conn->rxkad.nonce);
+
+	ret = kernel_sendmsg(conn->local->socket, &msg, iov, 2, len);
+	if (ret < 0) {
+		trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+				    rxrpc_tx_point_rxkad_challenge);
+		return -EAGAIN;
+	}
+
+	rxrpc_peer_mark_tx(conn->peer);
+	trace_rxrpc_tx_packet(conn->debug_id, &whdr,
+			      rxrpc_tx_point_rxkad_challenge);
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * calculate the response checksum
+ */
+static void rxkad_calc_response_checksum(struct rxkad_response *response)
+{
+	u32 csum = 1000003;
+	int loop;
+	u8 *p = (u8 *) response;
+
+	for (loop = sizeof(*response); loop > 0; loop--)
+		csum = csum * 0x10204081 + *p++;
+
+	response->encrypted.checksum = htonl(csum);
+}
+
+/*
+ * Validate a challenge packet.
+ */
+static bool rxkad_validate_challenge(struct rxrpc_connection *conn,
+				     struct sk_buff *skb)
+{
+	struct rxkad_challenge challenge;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	u32 version, min_level;
+	int ret;
+
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
+
+	if (!conn->key) {
+		rxrpc_abort_conn(conn, skb, RX_PROTOCOL_ERROR, -EPROTO,
+				 rxkad_abort_chall_no_key);
+		return false;
+	}
+
+	ret = key_validate(conn->key);
+	if (ret < 0) {
+		rxrpc_abort_conn(conn, skb, RXKADEXPIRED, ret,
+				 rxkad_abort_chall_key_expired);
+		return false;
+	}
+
+	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+			  &challenge, sizeof(challenge)) < 0) {
+		rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO,
+				 rxkad_abort_chall_short);
+		return false;
+	}
+
+	version = ntohl(challenge.version);
+	sp->chall.rxkad_nonce = ntohl(challenge.nonce);
+	min_level = ntohl(challenge.min_level);
+
+	trace_rxrpc_rx_challenge(conn, sp->hdr.serial, version,
+				 sp->chall.rxkad_nonce, min_level);
+
+	if (version != RXKAD_VERSION) {
+		rxrpc_abort_conn(conn, skb, RXKADINCONSISTENCY, -EPROTO,
+				 rxkad_abort_chall_version);
+		return false;
+	}
+
+	if (conn->security_level < min_level) {
+		rxrpc_abort_conn(conn, skb, RXKADLEVELFAIL, -EACCES,
+				 rxkad_abort_chall_level);
+		return false;
+	}
+	return true;
+}
+
+/*
+ * Insert the header into the response.
+ */
+static noinline
+int rxkad_insert_response_header(struct rxrpc_connection *conn,
+				 const struct rxrpc_key_token *token,
+				 struct sk_buff *challenge,
+				 struct sk_buff *response,
+				 size_t *offset)
+{
+	struct rxrpc_skb_priv *csp = rxrpc_skb(challenge);
+	struct {
+		struct rxrpc_wire_header whdr;
+		struct rxkad_response	resp;
+	} h;
+	int ret;
+
+	h.whdr.epoch			= htonl(conn->proto.epoch);
+	h.whdr.cid			= htonl(conn->proto.cid);
+	h.whdr.callNumber		= 0;
+	h.whdr.serial			= 0;
+	h.whdr.seq			= 0;
+	h.whdr.type			= RXRPC_PACKET_TYPE_RESPONSE;
+	h.whdr.flags			= conn->out_clientflag;
+	h.whdr.userStatus		= 0;
+	h.whdr.securityIndex		= conn->security_ix;
+	h.whdr.cksum			= 0;
+	h.whdr.serviceId		= htons(conn->service_id);
+	h.resp.version			= htonl(RXKAD_VERSION);
+	h.resp.__pad			= 0;
+	h.resp.encrypted.epoch		= htonl(conn->proto.epoch);
+	h.resp.encrypted.cid		= htonl(conn->proto.cid);
+	h.resp.encrypted.checksum	= 0;
+	h.resp.encrypted.securityIndex	= htonl(conn->security_ix);
+	h.resp.encrypted.call_id[0]	= htonl(conn->channels[0].call_counter);
+	h.resp.encrypted.call_id[1]	= htonl(conn->channels[1].call_counter);
+	h.resp.encrypted.call_id[2]	= htonl(conn->channels[2].call_counter);
+	h.resp.encrypted.call_id[3]	= htonl(conn->channels[3].call_counter);
+	h.resp.encrypted.inc_nonce	= htonl(csp->chall.rxkad_nonce + 1);
+	h.resp.encrypted.level		= htonl(conn->security_level);
+	h.resp.kvno			= htonl(token->kad->kvno);
+	h.resp.ticket_len		= htonl(token->kad->ticket_len);
+
+	rxkad_calc_response_checksum(&h.resp);
+
+	/* encrypt the response packet */
+	static_assert(sizeof(h.resp.encrypted) % FCRYPT_BSIZE == 0);
+	fcrypt_pcbc_encrypt(conn->rxkad.cipher, token->kad->session_key,
+			    &h.resp.encrypted, &h.resp.encrypted,
+			    sizeof(h.resp.encrypted) / FCRYPT_BSIZE);
+
+	ret = skb_store_bits(response, *offset, &h, sizeof(h));
+	*offset += sizeof(h);
+	return ret;
+}
+
+/*
+ * respond to a challenge packet
+ */
+static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
+				      struct sk_buff *challenge)
+{
+	const struct rxrpc_key_token *token;
+	struct rxrpc_skb_priv *csp, *rsp;
+	struct sk_buff *response;
+	size_t len, offset = 0;
+	int ret = -EPROTO;
+
+	_enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
+
+	ret = key_validate(conn->key);
+	if (ret < 0)
+		return rxrpc_abort_conn(conn, challenge, RXKADEXPIRED, ret,
+					rxkad_abort_chall_key_expired);
+
+	token = conn->key->payload.data[0];
+
+	/* build the response packet */
+	len = sizeof(struct rxrpc_wire_header) +
+		sizeof(struct rxkad_response) +
+		token->kad->ticket_len;
+
+	response = alloc_skb_with_frags(0, len, 0, &ret, GFP_NOFS);
+	if (!response)
+		goto error;
+	rxrpc_new_skb(response, rxrpc_skb_new_response_rxkad);
+	response->len = len;
+	response->data_len = len;
+
+	offset = 0;
+	ret = rxkad_insert_response_header(conn, token, challenge, response,
+					   &offset);
+	if (ret < 0)
+		goto error;
+
+	ret = skb_store_bits(response, offset, token->kad->ticket,
+			     token->kad->ticket_len);
+	if (ret < 0)
+		goto error;
+
+	csp = rxrpc_skb(challenge);
+	rsp = rxrpc_skb(response);
+	rsp->resp.len = len;
+	rsp->resp.challenge_serial = csp->hdr.serial;
+	rxrpc_post_response(conn, response);
+	response = NULL;
+	ret = 0;
+
+error:
+	rxrpc_free_skb(response, rxrpc_skb_put_response);
+	return ret;
+}
+
+/*
+ * RxKAD does automatic response only as there's nothing to manage that isn't
+ * already in the key.
+ */
+static int rxkad_sendmsg_respond_to_challenge(struct sk_buff *challenge,
+					      struct msghdr *msg)
+{
+	return -EINVAL;
+}
+
+/**
+ * rxkad_kernel_respond_to_challenge - Respond to a challenge with appdata
+ * @challenge: The challenge to respond to
+ *
+ * Allow a kernel application to respond to a CHALLENGE.
+ *
+ * Return: %0 if successful and a negative error code otherwise.
+ */
+int rxkad_kernel_respond_to_challenge(struct sk_buff *challenge)
+{
+	struct rxrpc_skb_priv *csp = rxrpc_skb(challenge);
+
+	return rxkad_respond_to_challenge(csp->chall.conn, challenge);
+}
+EXPORT_SYMBOL(rxkad_kernel_respond_to_challenge);
+
+/* Decrypt data in-place using DES-PCBC.  @len must be a multiple of 8. */
+VISIBLE_IF_KUNIT void des_pcbc_decrypt_inplace(const struct des_ctx *key,
+					       __le64 iv, u8 *data, size_t len)
+{
+	for (size_t i = 0; i < len; i += DES_BLOCK_SIZE) {
+		__le64 ctext, ptext;
+
+		ctext = get_unaligned((const __le64 *)&data[i]);
+		des_decrypt(key, (u8 *)&ptext, (const u8 *)&ctext);
+		ptext ^= iv;
+		put_unaligned(ptext, (__le64 *)&data[i]);
+		iv = ptext ^ ctext;
+	}
+}
+EXPORT_SYMBOL_IF_KUNIT(des_pcbc_decrypt_inplace);
+
+/*
+ * decrypt the kerberos IV ticket in the response
+ */
+static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
+				struct key *server_key,
+				struct sk_buff *skb,
+				void *ticket, size_t ticket_len,
+				struct rxrpc_crypt *_session_key,
+				time64_t *_expiry)
+{
+	struct rxrpc_crypt key;
+	struct in_addr addr;
+	unsigned int life;
+	time64_t issue, now;
+	bool little_endian;
+	u8 *p, *q, *name, *end;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(server_key));
+
+	*_expiry = 0;
+
+	ASSERT(server_key->payload.data[0] != NULL);
+
+	if (ticket_len % DES_BLOCK_SIZE != 0)
+		return rxrpc_abort_conn(conn, skb, RXKADBADTICKET, -EPROTO,
+					rxkad_abort_resp_tkt_short);
+	des_pcbc_decrypt_inplace(
+		server_key->payload.data[0],
+		get_unaligned((const __le64 *)&server_key->payload.data[2]),
+		ticket, ticket_len);
+	p = ticket;
+	end = p + ticket_len;
+
+#define Z(field, fieldl)						\
+	({								\
+		u8 *__str = p;						\
+		q = memchr(p, 0, end - p);				\
+		if (!q || q - p > field##_SZ)				\
+			return rxrpc_abort_conn(			\
+				conn, skb, RXKADBADTICKET, -EPROTO,	\
+				rxkad_abort_resp_tkt_##fieldl);		\
+		for (; p < q; p++)					\
+			if (!isprint(*p))				\
+				return rxrpc_abort_conn(		\
+					conn, skb, RXKADBADTICKET, -EPROTO, \
+					rxkad_abort_resp_tkt_##fieldl);	\
+		p++;							\
+		__str;							\
+	})
+
+	/* extract the ticket flags */
+	_debug("KIV FLAGS: %x", *p);
+	little_endian = *p & 1;
+	p++;
+
+	/* extract the authentication name */
+	name = Z(ANAME, aname);
+	_debug("KIV ANAME: %s", name);
+
+	/* extract the principal's instance */
+	name = Z(INST, inst);
+	_debug("KIV INST : %s", name);
+
+	/* extract the principal's authentication domain */
+	name = Z(REALM, realm);
+	_debug("KIV REALM: %s", name);
+
+	if (end - p < 4 + 8 + 4 + 2)
+		return rxrpc_abort_conn(conn, skb, RXKADBADTICKET, -EPROTO,
+					rxkad_abort_resp_tkt_short);
+
+	/* get the IPv4 address of the entity that requested the ticket */
+	memcpy(&addr, p, sizeof(addr));
+	p += 4;
+	_debug("KIV ADDR : %pI4", &addr);
+
+	/* get the session key from the ticket */
+	memcpy(&key, p, sizeof(key));
+	p += 8;
+	_debug("KIV KEY  : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
+	memcpy(_session_key, &key, sizeof(key));
+
+	/* get the ticket's lifetime */
+	life = *p++ * 5 * 60;
+	_debug("KIV LIFE : %u", life);
+
+	/* get the issue time of the ticket */
+	if (little_endian) {
+		__le32 stamp;
+		memcpy(&stamp, p, 4);
+		issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
+	} else {
+		__be32 stamp;
+		memcpy(&stamp, p, 4);
+		issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
+	}
+	p += 4;
+	now = ktime_get_real_seconds();
+	_debug("KIV ISSUE: %llx [%llx]", issue, now);
+
+	/* check the ticket is in date */
+	if (issue > now)
+		return rxrpc_abort_conn(conn, skb, RXKADNOAUTH, -EKEYREJECTED,
+					rxkad_abort_resp_tkt_future);
+	if (issue < now - life)
+		return rxrpc_abort_conn(conn, skb, RXKADEXPIRED, -EKEYEXPIRED,
+					rxkad_abort_resp_tkt_expired);
+
+	*_expiry = issue + life;
+
+	/* get the service name */
+	name = Z(SNAME, sname);
+	_debug("KIV SNAME: %s", name);
+
+	/* get the service instance name */
+	name = Z(INST, sinst);
+	_debug("KIV SINST: %s", name);
+	return 0;
+}
+
+/*
+ * decrypt the response packet
+ */
+static void rxkad_decrypt_response(struct rxrpc_connection *conn,
+				   struct rxkad_response *resp,
+				   const struct rxrpc_crypt *session_key)
+{
+	struct fcrypt_key cipher;
+
+	_enter(",,%08x%08x",
+	       ntohl(session_key->n[0]), ntohl(session_key->n[1]));
+
+	fcrypt_preparekey(&cipher, session_key->x);
+
+	static_assert(sizeof(resp->encrypted) % FCRYPT_BSIZE == 0);
+	fcrypt_pcbc_decrypt(&cipher, session_key->x, &resp->encrypted,
+			    &resp->encrypted,
+			    sizeof(resp->encrypted) / FCRYPT_BSIZE);
+	_leave("");
+}
+
+/*
+ * verify a response
+ */
+static int rxkad_verify_response(struct rxrpc_connection *conn,
+				 struct sk_buff *skb,
+				 void *buffer, unsigned int len)
+{
+	struct rxkad_response *response;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_crypt session_key;
+	struct key *server_key;
+	time64_t expiry;
+	void *ticket;
+	u32 version, kvno, ticket_len, level;
+	__be32 csum;
+	int ret, i;
+
+	_enter("{%d}", conn->debug_id);
+
+	server_key = rxrpc_look_up_server_security(conn, skb, 0, 0);
+	if (IS_ERR(server_key)) {
+		ret = PTR_ERR(server_key);
+		switch (ret) {
+		case -ENOKEY:
+			return rxrpc_abort_conn(conn, skb, RXKADUNKNOWNKEY, ret,
+						rxkad_abort_resp_nokey);
+		case -EKEYEXPIRED:
+			return rxrpc_abort_conn(conn, skb, RXKADEXPIRED, ret,
+						rxkad_abort_resp_key_expired);
+		default:
+			return rxrpc_abort_conn(conn, skb, RXKADNOAUTH, ret,
+						rxkad_abort_resp_key_rejected);
+		}
+	}
+
+	response = buffer;
+	if (len < sizeof(*response)) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO,
+				       rxkad_abort_resp_short);
+		goto error;
+	}
+
+	version = ntohl(response->version);
+	ticket_len = ntohl(response->ticket_len);
+	kvno = ntohl(response->kvno);
+
+	trace_rxrpc_rx_response(conn, sp->hdr.serial, version, kvno, ticket_len);
+
+	buffer	+= sizeof(*response);
+	len	-= sizeof(*response);
+
+	if (version != RXKAD_VERSION) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADINCONSISTENCY, -EPROTO,
+				       rxkad_abort_resp_version);
+		goto error;
+	}
+
+	if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADTICKETLEN, -EPROTO,
+				       rxkad_abort_resp_tkt_len);
+		goto error;
+	}
+
+	if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADUNKNOWNKEY, -EPROTO,
+				       rxkad_abort_resp_unknown_tkt);
+		goto error;
+	}
+
+	/* extract the kerberos ticket and decrypt and decode it */
+	ticket = buffer;
+	if (ticket_len > len) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADPACKETSHORT, -EPROTO,
+				       rxkad_abort_resp_short_tkt);
+		goto error;
+	}
+
+	ret = rxkad_decrypt_ticket(conn, server_key, skb, ticket, ticket_len,
+				   &session_key, &expiry);
+	if (ret < 0)
+		goto error;
+
+	/* use the session key from inside the ticket to decrypt the
+	 * response */
+	rxkad_decrypt_response(conn, response, &session_key);
+
+	if (ntohl(response->encrypted.epoch) != conn->proto.epoch ||
+	    ntohl(response->encrypted.cid) != conn->proto.cid ||
+	    ntohl(response->encrypted.securityIndex) != conn->security_ix) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO,
+				       rxkad_abort_resp_bad_param);
+		goto error;
+	}
+
+	csum = response->encrypted.checksum;
+	response->encrypted.checksum = 0;
+	rxkad_calc_response_checksum(response);
+	if (response->encrypted.checksum != csum) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO,
+				       rxkad_abort_resp_bad_checksum);
+		goto error;
+	}
+
+	for (i = 0; i < RXRPC_MAXCALLS; i++) {
+		u32 call_id = ntohl(response->encrypted.call_id[i]);
+		u32 counter = READ_ONCE(conn->channels[i].call_counter);
+
+		if (call_id > INT_MAX) {
+			ret = rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO,
+					       rxkad_abort_resp_bad_callid);
+			goto error;
+		}
+
+		if (call_id < counter) {
+			ret = rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO,
+					       rxkad_abort_resp_call_ctr);
+			goto error;
+		}
+
+		if (call_id > counter) {
+			if (conn->channels[i].call) {
+				ret = rxrpc_abort_conn(conn, skb, RXKADSEALEDINCON, -EPROTO,
+						 rxkad_abort_resp_call_state);
+				goto error;
+			}
+			conn->channels[i].call_counter = call_id;
+		}
+	}
+
+	if (ntohl(response->encrypted.inc_nonce) != conn->rxkad.nonce + 1) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADOUTOFSEQUENCE, -EPROTO,
+				       rxkad_abort_resp_ooseq);
+		goto error;
+	}
+
+	level = ntohl(response->encrypted.level);
+	if (level > RXRPC_SECURITY_ENCRYPT) {
+		ret = rxrpc_abort_conn(conn, skb, RXKADLEVELFAIL, -EPROTO,
+				       rxkad_abort_resp_level);
+		goto error;
+	}
+	conn->security_level = level;
+
+	/* create a key to hold the security data and expiration time - after
+	 * this the connection security can be handled in exactly the same way
+	 * as for a client connection */
+	ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
+
+error:
+	key_put(server_key);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * clear the connection security
+ */
+static void rxkad_clear(struct rxrpc_connection *conn)
+{
+	_enter("");
+
+	kfree_sensitive(conn->rxkad.cipher);
+	conn->rxkad.cipher = NULL;
+}
+
+/*
+ * Initialise the rxkad security service.
+ */
+static int rxkad_init(void)
+{
+	if (fips_enabled) {
+		pr_warn("rxkad support is disabled due to FIPS\n");
+		return -ENOENT;
+	}
+	return 0;
+}
+
+/*
+ * Clean up the rxkad security service.
+ */
+static void rxkad_exit(void)
+{
+}
+
+/*
+ * RxRPC Kerberos-based security
+ */
+const struct rxrpc_security rxkad = {
+	.name				= "rxkad",
+	.security_index			= RXRPC_SECURITY_RXKAD,
+	.no_key_abort			= RXKADUNKNOWNKEY,
+	.init				= rxkad_init,
+	.exit				= rxkad_exit,
+	.preparse_server_key		= rxkad_preparse_server_key,
+	.free_preparse_server_key	= rxkad_free_preparse_server_key,
+	.destroy_server_key		= rxkad_destroy_server_key,
+	.init_connection_security	= rxkad_init_connection_security,
+	.alloc_txbuf			= rxkad_alloc_txbuf,
+	.secure_packet			= rxkad_secure_packet,
+	.verify_packet			= rxkad_verify_packet,
+	.free_call_crypto		= rxkad_free_call_crypto,
+	.issue_challenge		= rxkad_issue_challenge,
+	.validate_challenge		= rxkad_validate_challenge,
+	.sendmsg_respond_to_challenge	= rxkad_sendmsg_respond_to_challenge,
+	.respond_to_challenge		= rxkad_respond_to_challenge,
+	.verify_response		= rxkad_verify_response,
+	.clear				= rxkad_clear,
+};
diff --git a/net/rxrpc/rxperf.c b/net/rxrpc/rxperf.c
new file mode 100644
index 000000000..b8df6d223
--- /dev/null
+++ b/net/rxrpc/rxperf.c
@@ -0,0 +1,703 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* In-kernel rxperf server for testing purposes.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "rxperf: " fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <crypto/krb5.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#define RXRPC_TRACE_ONLY_DEFINE_ENUMS
+#include <trace/events/rxrpc.h>
+
+MODULE_DESCRIPTION("rxperf test server (afs)");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+#define RXPERF_PORT		7009
+#define RX_PERF_SERVICE		147
+#define RX_PERF_VERSION		3
+#define RX_PERF_SEND		0
+#define RX_PERF_RECV		1
+#define RX_PERF_RPC		3
+#define RX_PERF_FILE		4
+#define RX_PERF_MAGIC_COOKIE	0x4711
+
+struct rxperf_proto_params {
+	__be32		version;
+	__be32		type;
+	__be32		rsize;
+	__be32		wsize;
+} __packed;
+
+static const u8 rxperf_magic_cookie[] = { 0x00, 0x00, 0x47, 0x11 };
+static const u8 secret[8] = { 0xa7, 0x83, 0x8a, 0xcb, 0xc7, 0x83, 0xec, 0x94 };
+
+enum rxperf_call_state {
+	RXPERF_CALL_SV_AWAIT_PARAMS,	/* Server: Awaiting parameter block */
+	RXPERF_CALL_SV_AWAIT_REQUEST,	/* Server: Awaiting request data */
+	RXPERF_CALL_SV_REPLYING,	/* Server: Replying */
+	RXPERF_CALL_SV_AWAIT_ACK,	/* Server: Awaiting final ACK */
+	RXPERF_CALL_COMPLETE,		/* Completed or failed */
+};
+
+struct rxperf_call {
+	struct rxrpc_call	*rxcall;
+	struct iov_iter		iter;
+	struct kvec		kvec[1];
+	struct work_struct	work;
+	const char		*type;
+	size_t			iov_len;
+	size_t			req_len;	/* Size of request blob */
+	size_t			reply_len;	/* Size of reply blob */
+	unsigned int		debug_id;
+	unsigned int		operation_id;
+	struct rxperf_proto_params params;
+	__be32			tmp[2];
+	s32			abort_code;
+	enum rxperf_call_state	state;
+	short			error;
+	unsigned short		unmarshal;
+	u16			service_id;
+	int (*deliver)(struct rxperf_call *call);
+	void (*processor)(struct work_struct *work);
+};
+
+static struct socket *rxperf_socket;
+static struct key *rxperf_sec_keyring;	/* Ring of security/crypto keys */
+static struct workqueue_struct *rxperf_workqueue;
+
+static void rxperf_deliver_to_call(struct work_struct *work);
+static int rxperf_deliver_param_block(struct rxperf_call *call);
+static int rxperf_deliver_request(struct rxperf_call *call);
+static int rxperf_process_call(struct rxperf_call *call);
+static void rxperf_charge_preallocation(struct work_struct *work);
+
+static DECLARE_WORK(rxperf_charge_preallocation_work,
+		    rxperf_charge_preallocation);
+
+static inline void rxperf_set_call_state(struct rxperf_call *call,
+					 enum rxperf_call_state to)
+{
+	call->state = to;
+}
+
+static inline void rxperf_set_call_complete(struct rxperf_call *call,
+					    int error, s32 remote_abort)
+{
+	if (call->state != RXPERF_CALL_COMPLETE) {
+		call->abort_code = remote_abort;
+		call->error = error;
+		call->state = RXPERF_CALL_COMPLETE;
+	}
+}
+
+static void rxperf_rx_discard_new_call(struct rxrpc_call *rxcall,
+				       unsigned long user_call_ID)
+{
+	kfree((struct rxperf_call *)user_call_ID);
+}
+
+static void rxperf_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
+			       unsigned long user_call_ID)
+{
+	queue_work(rxperf_workqueue, &rxperf_charge_preallocation_work);
+}
+
+static void rxperf_queue_call_work(struct rxperf_call *call)
+{
+	queue_work(rxperf_workqueue, &call->work);
+}
+
+static void rxperf_notify_rx(struct sock *sk, struct rxrpc_call *rxcall,
+			     unsigned long call_user_ID)
+{
+	struct rxperf_call *call = (struct rxperf_call *)call_user_ID;
+
+	if (call->state != RXPERF_CALL_COMPLETE)
+		rxperf_queue_call_work(call);
+}
+
+static void rxperf_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
+{
+	struct rxperf_call *call = (struct rxperf_call *)user_call_ID;
+
+	call->rxcall = rxcall;
+}
+
+static void rxperf_notify_end_reply_tx(struct sock *sock,
+				       struct rxrpc_call *rxcall,
+				       unsigned long call_user_ID)
+{
+	rxperf_set_call_state((struct rxperf_call *)call_user_ID,
+			      RXPERF_CALL_SV_AWAIT_ACK);
+}
+
+static const struct rxrpc_kernel_ops rxperf_rxrpc_callback_ops = {
+	.notify_new_call	= rxperf_rx_new_call,
+	.discard_new_call	= rxperf_rx_discard_new_call,
+	.user_attach_call	= rxperf_rx_attach,
+};
+
+/*
+ * Charge the incoming call preallocation.
+ */
+static void rxperf_charge_preallocation(struct work_struct *work)
+{
+	struct rxperf_call *call;
+
+	for (;;) {
+		call = kzalloc_obj(*call);
+		if (!call)
+			break;
+
+		call->type		= "unset";
+		call->debug_id		= atomic_inc_return(&rxrpc_debug_id);
+		call->deliver		= rxperf_deliver_param_block;
+		call->state		= RXPERF_CALL_SV_AWAIT_PARAMS;
+		call->service_id	= RX_PERF_SERVICE;
+		call->iov_len		= sizeof(call->params);
+		call->kvec[0].iov_len	= sizeof(call->params);
+		call->kvec[0].iov_base	= &call->params;
+		iov_iter_kvec(&call->iter, READ, call->kvec, 1, call->iov_len);
+		INIT_WORK(&call->work, rxperf_deliver_to_call);
+
+		if (rxrpc_kernel_charge_accept(rxperf_socket,
+					       rxperf_notify_rx,
+					       (unsigned long)call,
+					       GFP_KERNEL,
+					       call->debug_id) < 0)
+			break;
+		call = NULL;
+	}
+
+	kfree(call);
+}
+
+/*
+ * Open an rxrpc socket and bind it to be a server for callback notifications
+ * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
+ */
+static int rxperf_open_socket(void)
+{
+	struct sockaddr_rxrpc srx;
+	struct socket *socket;
+	int ret;
+
+	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6,
+			       &socket);
+	if (ret < 0)
+		goto error_1;
+
+	socket->sk->sk_allocation = GFP_NOFS;
+
+	/* bind the callback manager's address to make this a server socket */
+	memset(&srx, 0, sizeof(srx));
+	srx.srx_family			= AF_RXRPC;
+	srx.srx_service			= RX_PERF_SERVICE;
+	srx.transport_type		= SOCK_DGRAM;
+	srx.transport_len		= sizeof(srx.transport.sin6);
+	srx.transport.sin6.sin6_family	= AF_INET6;
+	srx.transport.sin6.sin6_port	= htons(RXPERF_PORT);
+
+	ret = rxrpc_sock_set_min_security_level(socket->sk,
+						RXRPC_SECURITY_ENCRYPT);
+	if (ret < 0)
+		goto error_2;
+
+	ret = rxrpc_sock_set_security_keyring(socket->sk, rxperf_sec_keyring);
+
+	ret = kernel_bind(socket, (struct sockaddr_unsized *)&srx, sizeof(srx));
+	if (ret < 0)
+		goto error_2;
+
+	rxrpc_kernel_set_notifications(socket, &rxperf_rxrpc_callback_ops);
+
+	ret = kernel_listen(socket, INT_MAX);
+	if (ret < 0)
+		goto error_2;
+
+	rxperf_socket = socket;
+	rxperf_charge_preallocation(&rxperf_charge_preallocation_work);
+	return 0;
+
+error_2:
+	sock_release(socket);
+error_1:
+	pr_err("Can't set up rxperf socket: %d\n", ret);
+	return ret;
+}
+
+/*
+ * close the rxrpc socket rxperf was using
+ */
+static void rxperf_close_socket(void)
+{
+	kernel_listen(rxperf_socket, 0);
+	kernel_sock_shutdown(rxperf_socket, SHUT_RDWR);
+	flush_workqueue(rxperf_workqueue);
+	sock_release(rxperf_socket);
+}
+
+/*
+ * Log remote abort codes that indicate that we have a protocol disagreement
+ * with the server.
+ */
+static void rxperf_log_error(struct rxperf_call *call, s32 remote_abort)
+{
+	static int max = 0;
+	const char *msg;
+	int m;
+
+	switch (remote_abort) {
+	case RX_EOF:		 msg = "unexpected EOF";	break;
+	case RXGEN_CC_MARSHAL:	 msg = "client marshalling";	break;
+	case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";	break;
+	case RXGEN_SS_MARSHAL:	 msg = "server marshalling";	break;
+	case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";	break;
+	case RXGEN_DECODE:	 msg = "opcode decode";		break;
+	case RXGEN_SS_XDRFREE:	 msg = "server XDR cleanup";	break;
+	case RXGEN_CC_XDRFREE:	 msg = "client XDR cleanup";	break;
+	case -32:		 msg = "insufficient data";	break;
+	default:
+		return;
+	}
+
+	m = max;
+	if (m < 3) {
+		max = m + 1;
+		pr_info("Peer reported %s failure on %s\n", msg, call->type);
+	}
+}
+
+/*
+ * deliver messages to a call
+ */
+static void rxperf_deliver_to_call(struct work_struct *work)
+{
+	struct rxperf_call *call = container_of(work, struct rxperf_call, work);
+	enum rxperf_call_state state;
+	u32 abort_code, remote_abort = 0;
+	int ret = 0;
+
+	if (call->state == RXPERF_CALL_COMPLETE)
+		return;
+
+	while (state = call->state,
+	       state == RXPERF_CALL_SV_AWAIT_PARAMS ||
+	       state == RXPERF_CALL_SV_AWAIT_REQUEST ||
+	       state == RXPERF_CALL_SV_AWAIT_ACK
+	       ) {
+		if (state == RXPERF_CALL_SV_AWAIT_ACK) {
+			if (!rxrpc_kernel_check_life(rxperf_socket, call->rxcall))
+				goto call_complete;
+			return;
+		}
+
+		ret = call->deliver(call);
+		if (ret == 0)
+			ret = rxperf_process_call(call);
+
+		switch (ret) {
+		case 0:
+			continue;
+		case -EINPROGRESS:
+		case -EAGAIN:
+			return;
+		case -ECONNABORTED:
+			rxperf_log_error(call, call->abort_code);
+			goto call_complete;
+		case -EOPNOTSUPP:
+			abort_code = RXGEN_OPCODE;
+			rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
+						abort_code, ret,
+						rxperf_abort_op_not_supported);
+			goto call_complete;
+		case -ENOTSUPP:
+			abort_code = RX_USER_ABORT;
+			rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
+						abort_code, ret,
+						rxperf_abort_op_not_supported);
+			goto call_complete;
+		case -EIO:
+			pr_err("Call %u in bad state %u\n",
+			       call->debug_id, call->state);
+			fallthrough;
+		case -ENODATA:
+		case -EBADMSG:
+		case -EMSGSIZE:
+		case -ENOMEM:
+		case -EFAULT:
+			rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
+						RXGEN_SS_UNMARSHAL, ret,
+						rxperf_abort_unmarshal_error);
+			goto call_complete;
+		default:
+			rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
+						RX_CALL_DEAD, ret,
+						rxperf_abort_general_error);
+			goto call_complete;
+		}
+	}
+
+call_complete:
+	rxperf_set_call_complete(call, ret, remote_abort);
+	/* The call may have been requeued */
+	rxrpc_kernel_shutdown_call(rxperf_socket, call->rxcall);
+	rxrpc_kernel_put_call(rxperf_socket, call->rxcall);
+	cancel_work(&call->work);
+	kfree(call);
+}
+
+/*
+ * Extract a piece of data from the received data socket buffers.
+ */
+static int rxperf_extract_data(struct rxperf_call *call, bool want_more)
+{
+	u32 remote_abort = 0;
+	int ret;
+
+	ret = rxrpc_kernel_recv_data(rxperf_socket, call->rxcall, &call->iter,
+				     &call->iov_len, want_more, &remote_abort,
+				     &call->service_id);
+	pr_debug("Extract i=%zu l=%zu m=%u ret=%d\n",
+		 iov_iter_count(&call->iter), call->iov_len, want_more, ret);
+	if (ret == 0 || ret == -EAGAIN)
+		return ret;
+
+	if (ret == 1) {
+		switch (call->state) {
+		case RXPERF_CALL_SV_AWAIT_REQUEST:
+			rxperf_set_call_state(call, RXPERF_CALL_SV_REPLYING);
+			break;
+		case RXPERF_CALL_COMPLETE:
+			pr_debug("premature completion %d", call->error);
+			return call->error;
+		default:
+			break;
+		}
+		return 0;
+	}
+
+	rxperf_set_call_complete(call, ret, remote_abort);
+	return ret;
+}
+
+/*
+ * Grab the operation ID from an incoming manager call.
+ */
+static int rxperf_deliver_param_block(struct rxperf_call *call)
+{
+	u32 version;
+	int ret;
+
+	/* Extract the parameter block */
+	ret = rxperf_extract_data(call, true);
+	if (ret < 0)
+		return ret;
+
+	version			= ntohl(call->params.version);
+	call->operation_id	= ntohl(call->params.type);
+	call->deliver		= rxperf_deliver_request;
+
+	if (version != RX_PERF_VERSION) {
+		pr_info("Version mismatch %x\n", version);
+		return -ENOTSUPP;
+	}
+
+	switch (call->operation_id) {
+	case RX_PERF_SEND:
+		call->type = "send";
+		call->reply_len = 0;
+		call->iov_len = 4;	/* Expect req size */
+		break;
+	case RX_PERF_RECV:
+		call->type = "recv";
+		call->req_len = 0;
+		call->iov_len = 4;	/* Expect reply size */
+		break;
+	case RX_PERF_RPC:
+		call->type = "rpc";
+		call->iov_len = 8;	/* Expect req size and reply size */
+		break;
+	case RX_PERF_FILE:
+		call->type = "file";
+		fallthrough;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	rxperf_set_call_state(call, RXPERF_CALL_SV_AWAIT_REQUEST);
+	return call->deliver(call);
+}
+
+/*
+ * Deliver the request data.
+ */
+static int rxperf_deliver_request(struct rxperf_call *call)
+{
+	int ret;
+
+	switch (call->unmarshal) {
+	case 0:
+		call->kvec[0].iov_len	= call->iov_len;
+		call->kvec[0].iov_base	= call->tmp;
+		iov_iter_kvec(&call->iter, READ, call->kvec, 1, call->iov_len);
+		call->unmarshal++;
+		fallthrough;
+	case 1:
+		ret = rxperf_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		switch (call->operation_id) {
+		case RX_PERF_SEND:
+			call->type = "send";
+			call->req_len	= ntohl(call->tmp[0]);
+			call->reply_len	= 0;
+			break;
+		case RX_PERF_RECV:
+			call->type = "recv";
+			call->req_len = 0;
+			call->reply_len	= ntohl(call->tmp[0]);
+			break;
+		case RX_PERF_RPC:
+			call->type = "rpc";
+			call->req_len	= ntohl(call->tmp[0]);
+			call->reply_len	= ntohl(call->tmp[1]);
+			break;
+		default:
+			pr_info("Can't parse extra params\n");
+			return -EIO;
+		}
+
+		pr_debug("CALL op=%s rq=%zx rp=%zx\n",
+			 call->type, call->req_len, call->reply_len);
+
+		call->iov_len = call->req_len;
+		iov_iter_discard(&call->iter, READ, call->req_len);
+		call->unmarshal++;
+		fallthrough;
+	case 2:
+		ret = rxperf_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		/* Deal with the terminal magic cookie. */
+		call->iov_len = 4;
+		call->kvec[0].iov_len	= call->iov_len;
+		call->kvec[0].iov_base	= call->tmp;
+		iov_iter_kvec(&call->iter, READ, call->kvec, 1, call->iov_len);
+		call->unmarshal++;
+		fallthrough;
+	case 3:
+		ret = rxperf_extract_data(call, false);
+		if (ret < 0)
+			return ret;
+		call->unmarshal++;
+		fallthrough;
+	default:
+		return 0;
+	}
+}
+
+/*
+ * Process a call for which we've received the request.
+ */
+static int rxperf_process_call(struct rxperf_call *call)
+{
+	struct msghdr msg = {};
+	struct bio_vec bv;
+	struct kvec iov[1];
+	ssize_t n;
+	size_t reply_len = call->reply_len, len;
+
+	rxrpc_kernel_set_tx_length(rxperf_socket, call->rxcall,
+				   reply_len + sizeof(rxperf_magic_cookie));
+
+	while (reply_len > 0) {
+		len = umin(reply_len, PAGE_SIZE);
+		bvec_set_page(&bv, ZERO_PAGE(0), len, 0);
+		iov_iter_bvec(&msg.msg_iter, WRITE, &bv, 1, len);
+		msg.msg_flags = MSG_MORE;
+		n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg,
+					   len, rxperf_notify_end_reply_tx);
+		if (n < 0)
+			return n;
+		if (n == 0)
+			return -EIO;
+		reply_len -= n;
+	}
+
+	len = sizeof(rxperf_magic_cookie);
+	iov[0].iov_base	= (void *)rxperf_magic_cookie;
+	iov[0].iov_len	= len;
+	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
+	msg.msg_flags = 0;
+	n = rxrpc_kernel_send_data(rxperf_socket, call->rxcall, &msg, len,
+				   rxperf_notify_end_reply_tx);
+	if (n >= 0)
+		return 0; /* Success */
+
+	if (n == -ENOMEM)
+		rxrpc_kernel_abort_call(rxperf_socket, call->rxcall,
+					RXGEN_SS_MARSHAL, -ENOMEM,
+					rxperf_abort_oom);
+	return n;
+}
+
+/*
+ * Add an rxkad key to the security keyring.
+ */
+static int rxperf_add_rxkad_key(struct key *keyring)
+{
+	key_ref_t kref;
+	int ret;
+
+	kref = key_create_or_update(make_key_ref(keyring, true),
+				    "rxrpc_s",
+				    __stringify(RX_PERF_SERVICE) ":2",
+				    secret,
+				    sizeof(secret),
+				    KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH
+				    | KEY_USR_VIEW,
+				    KEY_ALLOC_NOT_IN_QUOTA);
+
+	if (IS_ERR(kref)) {
+		pr_err("Can't allocate rxperf server key: %ld\n", PTR_ERR(kref));
+		return PTR_ERR(kref);
+	}
+
+	ret = key_link(keyring, key_ref_to_ptr(kref));
+	if (ret < 0)
+		pr_err("Can't link rxperf server key: %d\n", ret);
+	key_ref_put(kref);
+	return ret;
+}
+
+#ifdef CONFIG_RXGK
+/*
+ * Add a yfs-rxgk key to the security keyring.
+ */
+static int rxperf_add_yfs_rxgk_key(struct key *keyring, u32 enctype)
+{
+	const struct krb5_enctype *krb5 = crypto_krb5_find_enctype(enctype);
+	key_ref_t kref;
+	char name[64];
+	int ret;
+	u8 key[32];
+
+	if (!krb5 || krb5->key_len > sizeof(key))
+		return 0;
+
+	/* The key is just { 0, 1, 2, 3, 4, ... } */
+	for (int i = 0; i < krb5->key_len; i++)
+		key[i] = i;
+
+	sprintf(name, "%u:6:1:%u", RX_PERF_SERVICE, enctype);
+
+	kref = key_create_or_update(make_key_ref(keyring, true),
+				    "rxrpc_s", name,
+				    key, krb5->key_len,
+				    KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
+				    KEY_USR_VIEW,
+				    KEY_ALLOC_NOT_IN_QUOTA);
+
+	if (IS_ERR(kref)) {
+		pr_err("Can't allocate rxperf server key: %ld\n", PTR_ERR(kref));
+		return PTR_ERR(kref);
+	}
+
+	ret = key_link(keyring, key_ref_to_ptr(kref));
+	if (ret < 0)
+		pr_err("Can't link rxperf server key: %d\n", ret);
+	key_ref_put(kref);
+	return ret;
+}
+#endif
+
+/*
+ * Initialise the rxperf server.
+ */
+static int __init rxperf_init(void)
+{
+	struct key *keyring;
+	int ret = -ENOMEM;
+
+	pr_info("Server registering\n");
+
+	rxperf_workqueue = alloc_workqueue("rxperf", WQ_PERCPU, 0);
+	if (!rxperf_workqueue)
+		goto error_workqueue;
+
+	keyring = keyring_alloc("rxperf_server",
+				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, current_cred(),
+				KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
+				KEY_POS_WRITE |
+				KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH |
+				KEY_USR_WRITE |
+				KEY_OTH_VIEW | KEY_OTH_READ | KEY_OTH_SEARCH,
+				KEY_ALLOC_NOT_IN_QUOTA,
+				NULL, NULL);
+	if (IS_ERR(keyring)) {
+		pr_err("Can't allocate rxperf server keyring: %ld\n",
+		       PTR_ERR(keyring));
+		goto error_keyring;
+	}
+	rxperf_sec_keyring = keyring;
+	ret = rxperf_add_rxkad_key(keyring);
+	if (ret < 0)
+		goto error_key;
+#ifdef CONFIG_RXGK
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_AES128_CTS_HMAC_SHA1_96);
+	if (ret < 0)
+		goto error_key;
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_AES256_CTS_HMAC_SHA1_96);
+	if (ret < 0)
+		goto error_key;
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_AES128_CTS_HMAC_SHA256_128);
+	if (ret < 0)
+		goto error_key;
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_AES256_CTS_HMAC_SHA384_192);
+	if (ret < 0)
+		goto error_key;
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_CAMELLIA128_CTS_CMAC);
+	if (ret < 0)
+		goto error_key;
+	ret = rxperf_add_yfs_rxgk_key(keyring, KRB5_ENCTYPE_CAMELLIA256_CTS_CMAC);
+	if (ret < 0)
+		goto error_key;
+#endif
+
+	ret = rxperf_open_socket();
+	if (ret < 0)
+		goto error_socket;
+	return 0;
+
+error_socket:
+error_key:
+	key_put(rxperf_sec_keyring);
+error_keyring:
+	destroy_workqueue(rxperf_workqueue);
+	rcu_barrier();
+error_workqueue:
+	pr_err("Failed to register: %d\n", ret);
+	return ret;
+}
+late_initcall(rxperf_init); /* Must be called after net/ to create socket */
+
+static void __exit rxperf_exit(void)
+{
+	pr_info("Server unregistering.\n");
+
+	rxperf_close_socket();
+	key_put(rxperf_sec_keyring);
+	destroy_workqueue(rxperf_workqueue);
+	rcu_barrier();
+}
+module_exit(rxperf_exit);
+
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
new file mode 100644
index 000000000..2bfbf2b2b
--- /dev/null
+++ b/net/rxrpc/security.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC security handling
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/crypto.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include "ar-internal.h"
+
+static const struct rxrpc_security *rxrpc_security_types[] = {
+	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
+#ifdef CONFIG_RXKAD
+	[RXRPC_SECURITY_RXKAD]	= &rxkad,
+#endif
+#ifdef CONFIG_RXGK
+	[RXRPC_SECURITY_YFS_RXGK] = &rxgk_yfs,
+#endif
+};
+
+int __init rxrpc_init_security(void)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
+		if (rxrpc_security_types[i]) {
+			ret = rxrpc_security_types[i]->init();
+			if (ret < 0)
+				goto failed;
+		}
+	}
+
+	return 0;
+
+failed:
+	for (i--; i >= 0; i--)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+	return ret;
+}
+
+void rxrpc_exit_security(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
+		if (rxrpc_security_types[i])
+			rxrpc_security_types[i]->exit();
+}
+
+/*
+ * look up an rxrpc security module
+ */
+const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
+{
+	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
+		return NULL;
+	return rxrpc_security_types[security_index];
+}
+
+/*
+ * Initialise the security on a client call.
+ */
+int rxrpc_init_client_call_security(struct rxrpc_call *call)
+{
+	const struct rxrpc_security *sec = &rxrpc_no_security;
+	struct rxrpc_key_token *token;
+	struct key *key = call->key;
+	int ret;
+
+	if (!key)
+		goto found;
+
+	ret = key_validate(key);
+	if (ret < 0)
+		return ret;
+
+	for (token = key->payload.data[0]; token; token = token->next) {
+		sec = rxrpc_security_lookup(token->security_index);
+		if (sec)
+			goto found;
+	}
+	return -EKEYREJECTED;
+
+found:
+	call->security = sec;
+	call->security_ix = sec->security_index;
+	return 0;
+}
+
+/*
+ * initialise the security on a client connection
+ */
+int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
+{
+	struct rxrpc_key_token *token;
+	struct key *key = conn->key;
+	int ret = 0;
+
+	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
+
+	for (token = key->payload.data[0]; token; token = token->next) {
+		if (token->security_index == conn->security->security_index)
+			goto found;
+	}
+	return -EKEYREJECTED;
+
+found:
+	mutex_lock(&conn->security_lock);
+	if (conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
+		ret = conn->security->init_connection_security(conn, token);
+		if (ret == 0) {
+			spin_lock_irq(&conn->state_lock);
+			if (conn->state == RXRPC_CONN_CLIENT_UNSECURED)
+				conn->state = RXRPC_CONN_CLIENT;
+			spin_unlock_irq(&conn->state_lock);
+		}
+	}
+	mutex_unlock(&conn->security_lock);
+	return ret;
+}
+
+/*
+ * Set the ops a server connection.
+ */
+const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
+							 struct sk_buff *skb)
+{
+	const struct rxrpc_security *sec;
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+
+	_enter("");
+
+	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
+	if (!sec) {
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_unsupported_security,
+					RX_INVALID_OPERATION, -EKEYREJECTED);
+		return NULL;
+	}
+
+	if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
+	    !rx->securities) {
+		rxrpc_direct_conn_abort(skb, rxrpc_abort_no_service_key,
+					sec->no_key_abort, -EKEYREJECTED);
+		return NULL;
+	}
+
+	return sec;
+}
+
+/*
+ * Find the security key for a server connection.
+ */
+struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
+					  struct sk_buff *skb,
+					  u32 kvno, u32 enctype)
+{
+	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	struct rxrpc_sock *rx;
+	struct key *key = ERR_PTR(-EKEYREJECTED);
+	key_ref_t kref = NULL;
+	char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
+	int ret;
+
+	_enter("");
+
+	if (enctype)
+		sprintf(kdesc, "%u:%u:%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
+	else if (kvno)
+		sprintf(kdesc, "%u:%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
+	else
+		sprintf(kdesc, "%u:%u",
+			sp->hdr.serviceId, sp->hdr.securityIndex);
+
+	read_lock(&conn->local->services_lock);
+
+	rx = conn->local->service;
+	if (!rx)
+		goto out;
+
+	/* look through the service's keyring */
+	kref = keyring_search(make_key_ref(rx->securities, 1UL),
+			      &key_type_rxrpc_s, kdesc, true);
+	if (IS_ERR(kref)) {
+		key = ERR_CAST(kref);
+		goto out;
+	}
+
+	key = key_ref_to_ptr(kref);
+
+	ret = key_validate(key);
+	if (ret < 0) {
+		key_put(key);
+		key = ERR_PTR(ret);
+		goto out;
+	}
+
+out:
+	read_unlock(&conn->local->services_lock);
+	return key;
+}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644
index 000000000..ed2c9a510
--- /dev/null
+++ b/net/rxrpc/sendmsg.c
@@ -0,0 +1,877 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* AF_RXRPC sendmsg() implementation.
+ *
+ * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * Propose an abort to be made in the I/O thread.
+ */
+bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
+			 enum rxrpc_abort_reason why)
+{
+	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
+
+	if (!call->send_abort && !rxrpc_call_is_complete(call)) {
+		call->send_abort_why = why;
+		call->send_abort_err = error;
+		call->send_abort_seq = 0;
+		trace_rxrpc_abort_call(call, abort_code);
+		/* Request abort locklessly vs rxrpc_input_call_event(). */
+		smp_store_release(&call->send_abort, abort_code);
+		rxrpc_poke_call(call, rxrpc_call_poke_abort);
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Wait for a call to become connected.  Interruption here doesn't cause the
+ * call to be aborted.
+ */
+static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret = 0;
+
+	_enter("%d", call->debug_id);
+
+	if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
+		goto no_wait;
+
+	add_wait_queue_exclusive(&call->waitq, &myself);
+
+	for (;;) {
+		switch (call->interruptibility) {
+		case RXRPC_INTERRUPTIBLE:
+		case RXRPC_PREINTERRUPTIBLE:
+			set_current_state(TASK_INTERRUPTIBLE);
+			break;
+		case RXRPC_UNINTERRUPTIBLE:
+		default:
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			break;
+		}
+
+		if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
+			break;
+		if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
+		     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
+		    signal_pending(current)) {
+			ret = sock_intr_errno(*timeo);
+			break;
+		}
+		*timeo = schedule_timeout(*timeo);
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	__set_current_state(TASK_RUNNING);
+
+no_wait:
+	if (ret == 0 && rxrpc_call_is_complete(call))
+		ret = call->error;
+
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Return true if there's sufficient Tx queue space.
+ */
+static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
+{
+	rxrpc_seq_t tx_bottom = READ_ONCE(call->tx_bottom);
+
+	if (_tx_win)
+		*_tx_win = tx_bottom;
+	return call->send_top - tx_bottom < 256;
+}
+
+/*
+ * Wait for space to appear in the Tx queue or a signal to occur.
+ */
+static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
+					 struct rxrpc_call *call,
+					 long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (rxrpc_call_is_complete(call))
+			return call->error;
+
+		if (signal_pending(current))
+			return sock_intr_errno(*timeo);
+
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly, but with
+ * a timeout of 2*RTT if no progress was made and a signal occurred.
+ */
+static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call)
+{
+	rxrpc_seq_t tx_start, tx_win;
+	signed long rtt, timeout;
+
+	rtt = READ_ONCE(call->srtt_us) >> 3;
+	rtt = usecs_to_jiffies(rtt) * 2;
+	if (rtt < 2)
+		rtt = 2;
+
+	timeout = rtt;
+	tx_start = READ_ONCE(call->tx_bottom);
+
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+
+		if (rxrpc_check_tx_space(call, &tx_win))
+			return 0;
+
+		if (rxrpc_call_is_complete(call))
+			return call->error;
+
+		if (timeout == 0 &&
+		    tx_win == tx_start && signal_pending(current))
+			return -EINTR;
+
+		if (tx_win != tx_start) {
+			timeout = rtt;
+			tx_start = tx_win;
+		}
+
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
+		timeout = schedule_timeout(timeout);
+	}
+}
+
+/*
+ * Wait for space to appear in the Tx queue uninterruptibly.
+ */
+static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
+					    struct rxrpc_call *call,
+					    long *timeo)
+{
+	for (;;) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (rxrpc_check_tx_space(call, NULL))
+			return 0;
+
+		if (rxrpc_call_is_complete(call))
+			return call->error;
+
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
+		*timeo = schedule_timeout(*timeo);
+	}
+}
+
+/*
+ * wait for space to appear in the transmit/ACK window
+ * - caller holds the socket locked
+ */
+static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
+				    struct rxrpc_call *call,
+				    long *timeo,
+				    bool waitall)
+{
+	DECLARE_WAITQUEUE(myself, current);
+	int ret;
+
+	_enter(",{%u,%u,%u}",
+	       call->tx_bottom, call->tx_top, call->tx_winsize);
+
+	add_wait_queue(&call->waitq, &myself);
+
+	switch (call->interruptibility) {
+	case RXRPC_INTERRUPTIBLE:
+		if (waitall)
+			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
+		else
+			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
+		break;
+	case RXRPC_PREINTERRUPTIBLE:
+	case RXRPC_UNINTERRUPTIBLE:
+	default:
+		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
+		break;
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	set_current_state(TASK_RUNNING);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * Notify the owner of the call that the transmit phase is ended and the last
+ * packet has been queued.
+ */
+static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
+				rxrpc_notify_end_tx_t notify_end_tx)
+{
+	if (notify_end_tx)
+		notify_end_tx(&rx->sk, call, call->user_call_ID);
+}
+
+/*
+ * Queue a DATA packet for transmission, set the resend timeout and send
+ * the packet immediately.  Returns the error from rxrpc_send_data_packet()
+ * in case the caller wants to do something with it.
+ */
+static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
+			       struct rxrpc_txbuf *txb,
+			       rxrpc_notify_end_tx_t notify_end_tx)
+{
+	struct rxrpc_txqueue *sq = call->send_queue;
+	rxrpc_seq_t seq = txb->seq;
+	bool poke, last = txb->flags & RXRPC_LAST_PACKET;
+	int ix = seq & RXRPC_TXQ_MASK;
+	rxrpc_inc_stat(call->rxnet, stat_tx_data);
+
+	ASSERTCMP(txb->seq, ==, call->send_top + 1);
+
+	if (last)
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
+	else
+		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
+
+	if (WARN_ON_ONCE(sq->bufs[ix]))
+		trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue_dup);
+	else
+		trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue);
+
+	/* Add the packet to the call's output buffer */
+	poke = (READ_ONCE(call->tx_bottom) == call->send_top);
+	sq->bufs[ix] = txb;
+	/* Order send_top after the queue->next pointer and txb content. */
+	smp_store_release(&call->send_top, seq);
+	if (last) {
+		set_bit(RXRPC_CALL_TX_NO_MORE, &call->flags);
+		rxrpc_notify_end_tx(rx, call, notify_end_tx);
+		call->send_queue = NULL;
+	}
+
+	if (poke)
+		rxrpc_poke_call(call, rxrpc_call_poke_start);
+}
+
+/*
+ * Allocate a new txqueue unit and add it to the transmission queue.
+ */
+static int rxrpc_alloc_txqueue(struct sock *sk, struct rxrpc_call *call)
+{
+	struct rxrpc_txqueue *tq;
+
+	tq = kzalloc_obj(*tq, sk->sk_allocation);
+	if (!tq)
+		return -ENOMEM;
+
+	tq->xmit_ts_base = KTIME_MIN;
+	for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
+		tq->segment_xmit_ts[i] = UINT_MAX;
+
+	if (call->send_queue) {
+		tq->qbase = call->send_top + 1;
+		call->send_queue->next = tq;
+		call->send_queue = tq;
+	} else if (WARN_ON(call->tx_queue)) {
+		kfree(tq);
+		return -ENOMEM;
+	} else {
+		/* We start at seq 1, so pretend seq 0 is hard-acked. */
+		tq->nr_reported_acks = 1;
+		tq->segment_acked = 1UL;
+		tq->qbase = 0;
+		call->tx_qbase = 0;
+		call->send_queue = tq;
+		call->tx_qtail = tq;
+		call->tx_queue = tq;
+	}
+
+	trace_rxrpc_tq(call, tq, call->send_top, rxrpc_tq_alloc);
+	return 0;
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - The caller holds the call user access mutex, but not the socket lock.
+ */
+static int rxrpc_send_data(struct rxrpc_sock *rx,
+			   struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len,
+			   rxrpc_notify_end_tx_t notify_end_tx,
+			   bool *_dropped_lock)
+{
+	struct rxrpc_txbuf *txb;
+	struct sock *sk = &rx->sk;
+	enum rxrpc_call_state state;
+	long timeo;
+	bool more = msg->msg_flags & MSG_MORE;
+	int ret, copied = 0;
+
+	if (test_bit(RXRPC_CALL_TX_NO_MORE, &call->flags)) {
+		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
+				  call->cid, call->call_id, call->rx_consumed,
+				  0, -EPROTO);
+		return -EPROTO;
+	}
+
+	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+	ret = rxrpc_wait_to_be_connected(call, &timeo);
+	if (ret < 0)
+		return ret;
+
+	if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
+		ret = rxrpc_init_client_conn_security(call->conn);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* this should be in poll */
+	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
+
+reload:
+	txb = call->tx_pending;
+	call->tx_pending = NULL;
+	if (txb)
+		rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
+
+	ret = -EPIPE;
+	if (sk->sk_shutdown & SEND_SHUTDOWN)
+		goto maybe_error;
+	state = rxrpc_call_state(call);
+	ret = -ESHUTDOWN;
+	if (state >= RXRPC_CALL_COMPLETE)
+		goto maybe_error;
+	ret = -EPROTO;
+	if (state != RXRPC_CALL_CLIENT_PRE_SEND &&
+	    state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+	    state != RXRPC_CALL_SERVER_SEND_REPLY) {
+		/* Request phase complete for this client call */
+		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
+				  call->cid, call->call_id, call->rx_consumed,
+				  0, -EPROTO);
+		goto maybe_error;
+	}
+
+	ret = -EMSGSIZE;
+	if (call->tx_total_len != -1) {
+		if (len - copied > call->tx_total_len)
+			goto maybe_error;
+		if (!more && len - copied != call->tx_total_len)
+			goto maybe_error;
+	}
+
+	do {
+		if (!txb) {
+			size_t remain;
+
+			_debug("alloc");
+
+			if (!rxrpc_check_tx_space(call, NULL))
+				goto wait_for_space;
+
+			/* See if we need to begin/extend the Tx queue. */
+			if (!call->send_queue || !((call->send_top + 1) & RXRPC_TXQ_MASK)) {
+				ret = rxrpc_alloc_txqueue(sk, call);
+				if (ret < 0)
+					goto maybe_error;
+			}
+
+			/* Work out the maximum size of a packet.  Assume that
+			 * the security header is going to be in the padded
+			 * region (enc blocksize), but the trailer is not.
+			 */
+			remain = more ? INT_MAX : msg_data_left(msg);
+			txb = call->conn->security->alloc_txbuf(call, remain, sk->sk_allocation);
+			if (!txb) {
+				ret = -ENOMEM;
+				goto maybe_error;
+			}
+		}
+
+		_debug("append");
+
+		/* append next segment of data to the current buffer */
+		if (msg_data_left(msg) > 0) {
+			size_t copy = umin(txb->space, msg_data_left(msg));
+
+			_debug("add %zu", copy);
+			if (!copy_from_iter_full(txb->data + txb->offset,
+						 copy, &msg->msg_iter))
+				goto efault;
+			_debug("added");
+			txb->space -= copy;
+			txb->len += copy;
+			txb->offset += copy;
+			copied += copy;
+			if (call->tx_total_len != -1)
+				call->tx_total_len -= copy;
+		}
+
+		/* check for the far side aborting the call or a network error
+		 * occurring */
+		if (rxrpc_call_is_complete(call))
+			goto call_terminated;
+
+		/* add the packet to the send queue if it's now full */
+		if (!txb->space ||
+		    (msg_data_left(msg) == 0 && !more)) {
+			if (msg_data_left(msg) == 0 && !more)
+				txb->flags |= RXRPC_LAST_PACKET;
+
+			ret = call->security->secure_packet(call, txb);
+			if (ret < 0)
+				goto out;
+			rxrpc_queue_packet(rx, call, txb, notify_end_tx);
+			txb = NULL;
+		}
+	} while (msg_data_left(msg) > 0);
+
+success:
+	ret = copied;
+	if (rxrpc_call_is_complete(call) &&
+	    call->error < 0)
+		ret = call->error;
+out:
+	call->tx_pending = txb;
+	_leave(" = %d", ret);
+	return ret;
+
+call_terminated:
+	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
+	_leave(" = %d", call->error);
+	return call->error;
+
+maybe_error:
+	if (copied)
+		goto success;
+	goto out;
+
+efault:
+	ret = -EFAULT;
+	goto out;
+
+wait_for_space:
+	ret = -EAGAIN;
+	if (msg->msg_flags & MSG_DONTWAIT)
+		goto maybe_error;
+	mutex_unlock(&call->user_mutex);
+	*_dropped_lock = true;
+	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
+				       msg->msg_flags & MSG_WAITALL);
+	if (ret < 0)
+		goto maybe_error;
+	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
+		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
+			ret = sock_intr_errno(timeo);
+			goto maybe_error;
+		}
+	} else {
+		mutex_lock(&call->user_mutex);
+	}
+	*_dropped_lock = false;
+	goto reload;
+}
+
+/*
+ * extract control messages from the sendmsg() control buffer
+ */
+static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
+{
+	struct cmsghdr *cmsg;
+	bool got_user_ID = false;
+	int len;
+
+	if (msg->msg_controllen == 0)
+		return -EINVAL;
+
+	for_each_cmsghdr(cmsg, msg) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+
+		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
+		_debug("CMSG %d, %d, %d",
+		       cmsg->cmsg_level, cmsg->cmsg_type, len);
+
+		if (cmsg->cmsg_level != SOL_RXRPC)
+			continue;
+
+		switch (cmsg->cmsg_type) {
+		case RXRPC_USER_CALL_ID:
+			if (msg->msg_flags & MSG_CMSG_COMPAT) {
+				if (len != sizeof(u32))
+					return -EINVAL;
+				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
+			} else {
+				if (len != sizeof(unsigned long))
+					return -EINVAL;
+				p->call.user_call_ID = *(unsigned long *)
+					CMSG_DATA(cmsg);
+			}
+			got_user_ID = true;
+			break;
+
+		case RXRPC_ABORT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_SEND_ABORT;
+			if (len != sizeof(p->abort_code))
+				return -EINVAL;
+			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
+			if (p->abort_code == 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_CHARGE_ACCEPT:
+			if (p->command != RXRPC_CMD_SEND_DATA)
+				return -EINVAL;
+			p->command = RXRPC_CMD_CHARGE_ACCEPT;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_EXCLUSIVE_CALL:
+			p->exclusive = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_UPGRADE_SERVICE:
+			p->upgrade = true;
+			if (len != 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_TX_LENGTH:
+			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
+				return -EINVAL;
+			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
+			if (p->call.tx_total_len < 0)
+				return -EINVAL;
+			break;
+
+		case RXRPC_SET_CALL_TIMEOUT:
+			if (len & 3 || len < 4 || len > 12)
+				return -EINVAL;
+			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
+			p->call.nr_timeouts = len / 4;
+			if (p->call.timeouts.hard > INT_MAX / HZ)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
+				return -ERANGE;
+			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
+				return -ERANGE;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (!got_user_ID)
+		return -EINVAL;
+	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
+		return -EINVAL;
+	_leave(" = 0");
+	return 0;
+}
+
+/*
+ * Create a new client call for sendmsg().
+ * - Called with the socket lock held, which it must release.
+ * - If it returns a call, the call's lock will need releasing by the caller.
+ */
+static struct rxrpc_call *
+rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
+				  struct rxrpc_send_params *p)
+	__releases(&rx->sk.sk_lock)
+	__acquires(&call->user_mutex)
+{
+	struct rxrpc_conn_parameters cp;
+	struct rxrpc_peer *peer;
+	struct rxrpc_call *call;
+	struct key *key;
+
+	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
+
+	_enter("");
+
+	if (!msg->msg_name) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-EDESTADDRREQ);
+	}
+
+	peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
+	if (!peer) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	key = rx->key;
+	if (key && !rx->key->payload.data[0])
+		key = NULL;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.local		= rx->local;
+	cp.peer			= peer;
+	cp.key			= key;
+	cp.security_level	= rx->min_sec_level;
+	cp.exclusive		= rx->exclusive | p->exclusive;
+	cp.upgrade		= p->upgrade;
+	cp.service_id		= srx->srx_service;
+	call = rxrpc_new_client_call(rx, &cp, &p->call, GFP_KERNEL,
+				     atomic_inc_return(&rxrpc_debug_id));
+	/* The socket is now unlocked */
+
+	rxrpc_put_peer(peer, rxrpc_peer_put_application);
+	_leave(" = %p\n", call);
+	return call;
+}
+
+/*
+ * send a message forming part of a client call through an RxRPC socket
+ * - caller holds the socket locked
+ * - the socket may be either a client socket or a server socket
+ */
+int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
+{
+	struct rxrpc_call *call;
+	bool dropped_lock = false;
+	int ret;
+
+	struct rxrpc_send_params p = {
+		.call.tx_total_len	= -1,
+		.call.user_call_ID	= 0,
+		.call.nr_timeouts	= 0,
+		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
+		.abort_code		= 0,
+		.command		= RXRPC_CMD_SEND_DATA,
+		.exclusive		= false,
+		.upgrade		= false,
+	};
+
+	_enter("");
+
+	ret = rxrpc_sendmsg_cmsg(msg, &p);
+	if (ret < 0)
+		goto error_release_sock;
+
+	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
+		ret = -EINVAL;
+		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
+			goto error_release_sock;
+		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
+		goto error_release_sock;
+	}
+
+	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
+	if (!call) {
+		ret = -EBADSLT;
+		if (p.command != RXRPC_CMD_SEND_DATA)
+			goto error_release_sock;
+		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
+		/* The socket is now unlocked... */
+		if (IS_ERR(call))
+			return PTR_ERR(call);
+		/* ... and we have the call lock. */
+		p.call.nr_timeouts = 0;
+		ret = 0;
+		if (rxrpc_call_is_complete(call))
+			goto out_put_unlock;
+	} else {
+		switch (rxrpc_call_state(call)) {
+		case RXRPC_CALL_CLIENT_AWAIT_CONN:
+		case RXRPC_CALL_SERVER_RECV_REQUEST:
+			if (p.command == RXRPC_CMD_SEND_ABORT)
+				break;
+			fallthrough;
+		case RXRPC_CALL_UNINITIALISED:
+		case RXRPC_CALL_SERVER_PREALLOC:
+			rxrpc_put_call(call, rxrpc_call_put_sendmsg);
+			ret = -EBUSY;
+			goto error_release_sock;
+		default:
+			break;
+		}
+
+		ret = mutex_lock_interruptible(&call->user_mutex);
+		release_sock(&rx->sk);
+		if (ret < 0) {
+			ret = -ERESTARTSYS;
+			goto error_put;
+		}
+
+		if (p.call.tx_total_len != -1) {
+			ret = -EINVAL;
+			if (call->tx_total_len != -1 ||
+			    call->tx_pending ||
+			    call->tx_top != 0)
+				goto out_put_unlock;
+			call->tx_total_len = p.call.tx_total_len;
+		}
+	}
+
+	switch (p.call.nr_timeouts) {
+	case 3:
+		WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
+		fallthrough;
+	case 2:
+		WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
+		fallthrough;
+	case 1:
+		if (p.call.timeouts.hard > 0) {
+			ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);
+
+			WRITE_ONCE(call->expect_term_by,
+				   ktime_add(p.call.timeouts.hard,
+					     ktime_get_real()));
+			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
+			rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);
+
+		}
+		break;
+	}
+
+	if (rxrpc_call_is_complete(call)) {
+		/* it's too late for this call */
+		ret = -ESHUTDOWN;
+		goto out_put_unlock;
+	}
+
+	switch (p.command) {
+	case RXRPC_CMD_SEND_ABORT:
+		rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
+				    rxrpc_abort_call_sendmsg);
+		ret = 0;
+		break;
+	case RXRPC_CMD_SEND_DATA:
+		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+out_put_unlock:
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+error_put:
+	rxrpc_put_call(call, rxrpc_call_put_sendmsg);
+	_leave(" = %d", ret);
+	return ret;
+
+error_release_sock:
+	release_sock(&rx->sk);
+	return ret;
+}
+
+/**
+ * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
+ * @sock: The socket the call is on
+ * @call: The call to send data through
+ * @msg: The data to send
+ * @len: The amount of data to send
+ * @notify_end_tx: Notification that the last packet is queued.
+ *
+ * Allow a kernel service to send data on a call.  The call must be in an state
+ * appropriate to sending data.  No control data should be supplied in @msg,
+ * nor should an address be supplied.  MSG_MORE should be flagged if there's
+ * more data to come, otherwise this data will end the transmission phase.
+ *
+ * Return: %0 if successful and a negative error code otherwise.
+ */
+int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
+			   struct msghdr *msg, size_t len,
+			   rxrpc_notify_end_tx_t notify_end_tx)
+{
+	bool dropped_lock = false;
+	int ret;
+
+	_enter("{%d},", call->debug_id);
+
+	ASSERTCMP(msg->msg_name, ==, NULL);
+	ASSERTCMP(msg->msg_control, ==, NULL);
+
+	mutex_lock(&call->user_mutex);
+
+	ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
+			      notify_end_tx, &dropped_lock);
+	if (ret == -ESHUTDOWN)
+		ret = call->error;
+
+	if (!dropped_lock)
+		mutex_unlock(&call->user_mutex);
+	_leave(" = %d", ret);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_kernel_send_data);
+
+/**
+ * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
+ * @sock: The socket the call is on
+ * @call: The call to be aborted
+ * @abort_code: The abort code to stick into the ABORT packet
+ * @error: Local error value
+ * @why: Indication as to why.
+ *
+ * Allow a kernel service to abort a call if it's still in an abortable state.
+ *
+ * Return: %true if the call was aborted, %false if it was already complete.
+ */
+bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
+			     u32 abort_code, int error, enum rxrpc_abort_reason why)
+{
+	bool aborted;
+
+	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
+
+	mutex_lock(&call->user_mutex);
+	aborted = rxrpc_propose_abort(call, abort_code, error, why);
+	mutex_unlock(&call->user_mutex);
+	return aborted;
+}
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);
+
+/**
+ * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
+ * @sock: The socket the call is on
+ * @call: The call to be informed
+ * @tx_total_len: The amount of data to be transmitted for this call
+ *
+ * Allow a kernel service to set the total transmit length on a call.  This
+ * allows buffer-to-packet encrypt-and-copy to be performed.
+ *
+ * This function is primarily for use for setting the reply length since the
+ * request length can be set when beginning the call.
+ */
+void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
+				s64 tx_total_len)
+{
+	WARN_ON(call->tx_total_len != -1);
+	call->tx_total_len = tx_total_len;
+}
+EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
diff --git a/net/rxrpc/server_key.c b/net/rxrpc/server_key.c
new file mode 100644
index 000000000..3efe104b1
--- /dev/null
+++ b/net/rxrpc/server_key.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *	"afs@CAMBRIDGE.REDHAT.COM>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_vet_description_s(const char *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_destroy_s(struct key *);
+static void rxrpc_describe_s(const struct key *, struct seq_file *);
+
+/*
+ * rxrpc server keys take "<serviceId>:<securityIndex>[:<sec-specific>]" as the
+ * description and the key material as the payload.
+ */
+struct key_type key_type_rxrpc_s = {
+	.name		= "rxrpc_s",
+	.flags		= KEY_TYPE_NET_DOMAIN,
+	.vet_description = rxrpc_vet_description_s,
+	.preparse	= rxrpc_preparse_s,
+	.free_preparse	= rxrpc_free_preparse_s,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy_s,
+	.describe	= rxrpc_describe_s,
+};
+
+/*
+ * Vet the description for an RxRPC server key.
+ */
+static int rxrpc_vet_description_s(const char *desc)
+{
+	unsigned long service, sec_class;
+	char *p;
+
+	service = simple_strtoul(desc, &p, 10);
+	if (*p != ':' || service > 65535)
+		return -EINVAL;
+	sec_class = simple_strtoul(p + 1, &p, 10);
+	if ((*p && *p != ':') || sec_class < 1 || sec_class > 255)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * Preparse a server secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
+{
+	const struct rxrpc_security *sec;
+	unsigned int service, sec_class;
+	int n;
+
+	_enter("%zu", prep->datalen);
+
+	if (!prep->orig_description)
+		return -EINVAL;
+
+	if (sscanf(prep->orig_description, "%u:%u%n", &service, &sec_class, &n) != 2)
+		return -EINVAL;
+
+	sec = rxrpc_security_lookup(sec_class);
+	if (!sec)
+		return -ENOPKG;
+
+	prep->payload.data[1] = (struct rxrpc_security *)sec;
+
+	if (!sec->preparse_server_key)
+		return -EINVAL;
+
+	return sec->preparse_server_key(prep);
+}
+
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+	const struct rxrpc_security *sec = prep->payload.data[1];
+
+	if (sec && sec->free_preparse_server_key)
+		sec->free_preparse_server_key(prep);
+}
+
+static void rxrpc_destroy_s(struct key *key)
+{
+	const struct rxrpc_security *sec = key->payload.data[1];
+
+	if (sec && sec->destroy_server_key)
+		sec->destroy_server_key(key);
+}
+
+static void rxrpc_describe_s(const struct key *key, struct seq_file *m)
+{
+	const struct rxrpc_security *sec = key->payload.data[1];
+
+	seq_puts(m, key->description);
+	if (sec && sec->describe_server_key)
+		sec->describe_server_key(key, m);
+}
+
+/*
+ * grab the security keyring for a server socket
+ */
+int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (rx->securities)
+		return -EINVAL;
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+		return -EINVAL;
+
+	description = memdup_sockptr_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key(&key_type_keyring, description, NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->securities = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}
+
+/**
+ * rxrpc_sock_set_security_keyring - Set the security keyring for a kernel service
+ * @sk: The socket to set the keyring on
+ * @keyring: The keyring to set
+ *
+ * Set the server security keyring on an rxrpc socket.  This is used to provide
+ * the encryption keys for a kernel service.
+ *
+ * Return: %0 if successful and a negative error code otherwise.
+ */
+int rxrpc_sock_set_security_keyring(struct sock *sk, struct key *keyring)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	int ret = 0;
+
+	lock_sock(sk);
+	if (rx->securities)
+		ret = -EINVAL;
+	else if (rx->sk.sk_state != RXRPC_UNBOUND)
+		ret = -EISCONN;
+	else
+		rx->securities = key_get(keyring);
+	release_sock(sk);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_sock_set_security_keyring);
+
+/**
+ * rxrpc_sock_set_manage_response - Set the manage-response flag for a kernel service
+ * @sk: The socket to set the keyring on
+ * @set: True to set, false to clear the flag
+ *
+ * Set the flag on an rxrpc socket to say that the caller wants to manage the
+ * RESPONSE packet and the user-defined data it may contain.  Setting this
+ * means that recvmsg() will return messages with RXRPC_CHALLENGED in the
+ * control message buffer containing information about the challenge.
+ *
+ * The user should respond to the challenge by passing RXRPC_RESPOND or
+ * RXRPC_RESPOND_ABORT control messages with sendmsg() to the same call.
+ * Supplementary control messages, such as RXRPC_RESP_RXGK_APPDATA, may be
+ * included to indicate the parts the user wants to supply.
+ *
+ * The server will be passed the response data with a RXRPC_RESPONDED control
+ * message when it gets the first data from each call.
+ *
+ * Note that this is only honoured by security classes that need auxiliary data
+ * (e.g. RxGK).  Those that don't offer the facility (e.g. RxKAD) respond
+ * without consulting userspace.
+ *
+ * Return: The previous setting.
+ */
+int rxrpc_sock_set_manage_response(struct sock *sk, bool set)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sk);
+	int ret;
+
+	lock_sock(sk);
+	ret = !!test_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags);
+	if (set)
+		set_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags);
+	else
+		clear_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags);
+	release_sock(sk);
+	return ret;
+}
+EXPORT_SYMBOL(rxrpc_sock_set_manage_response);
diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c
new file mode 100644
index 000000000..e2169d1a1
--- /dev/null
+++ b/net/rxrpc/skbuff.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Socket buffer accounting
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+#define select_skb_count(skb) (&rxrpc_n_rx_skbs)
+
+/*
+ * Note the allocation or reception of a socket buffer.
+ */
+void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+}
+
+/*
+ * Note the re-emergence of a socket buffer from a queue or buffer.
+ */
+void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	if (skb) {
+		int n = atomic_read(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+	}
+}
+
+/*
+ * Note the addition of a ref on a socket buffer.
+ */
+void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	int n = atomic_inc_return(select_skb_count(skb));
+	trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+	skb_get(skb);
+}
+
+/*
+ * Note the destruction of a socket buffer.
+ */
+void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace why)
+{
+	if (skb) {
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n, why);
+		consume_skb(skb);
+	}
+}
+
+/*
+ * Clear a queue of socket buffers.
+ */
+void rxrpc_purge_queue(struct sk_buff_head *list)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue((list))) != NULL) {
+		int n = atomic_dec_return(select_skb_count(skb));
+		trace_rxrpc_skb(skb, refcount_read(&skb->users), n,
+				rxrpc_skb_put_purge);
+		consume_skb(skb);
+	}
+}
diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c
new file mode 100644
index 000000000..46a20cf4c
--- /dev/null
+++ b/net/rxrpc/sysctl.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* sysctls for configuring RxRPC operating parameters
+ *
+ * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/sysctl.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static struct ctl_table_header *rxrpc_sysctl_reg_table;
+static const unsigned int rxrpc_rx_mtu_min = 500;
+static const unsigned int rxrpc_jumbo_max = RXRPC_MAX_NR_JUMBO;
+static const unsigned int four = 4;
+static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1;
+static const unsigned int n_65535 = 65535;
+static const unsigned int n_max_acks = 255;
+static const unsigned long one_ms = 1;
+static const unsigned long max_ms = 1000;
+static const unsigned long one_jiffy = 1;
+static const unsigned long max_jiffies = MAX_JIFFY_OFFSET;
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+static const unsigned long max_500 = 500;
+#endif
+
+/*
+ * RxRPC operating parameters.
+ *
+ * See Documentation/networking/rxrpc.rst and the variable definitions for more
+ * information on the individual parameters.
+ */
+static struct ctl_table rxrpc_sysctl_table[] = {
+	/* Values measured in milliseconds */
+	{
+		.procname	= "soft_ack_delay",
+		.data		= &rxrpc_soft_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)&one_ms,
+		.extra2		= (void *)&max_ms,
+	},
+	{
+		.procname	= "idle_ack_delay",
+		.data		= &rxrpc_idle_ack_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)&one_ms,
+		.extra2		= (void *)&max_ms,
+	},
+	{
+		.procname	= "idle_conn_expiry",
+		.data		= &rxrpc_conn_idle_client_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+	{
+		.procname	= "idle_conn_fast_expiry",
+		.data		= &rxrpc_conn_idle_client_fast_expiry,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_ms_jiffies_minmax,
+		.extra1		= (void *)&one_jiffy,
+		.extra2		= (void *)&max_jiffies,
+	},
+
+	/* Values used in milliseconds */
+#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
+	{
+		.procname	= "inject_rx_delay",
+		.data		= &rxrpc_inject_rx_delay,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+		.extra1		= (void *)SYSCTL_LONG_ZERO,
+		.extra2		= (void *)&max_500,
+	},
+#endif
+
+	/* Non-time values */
+	{
+		.procname	= "reap_client_conns",
+		.data		= &rxrpc_reap_client_connections,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "max_backlog",
+		.data		= &rxrpc_max_backlog,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&four,
+		.extra2		= (void *)&max_backlog,
+	},
+	{
+		.procname	= "rx_window_size",
+		.data		= &rxrpc_rx_window_size,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&n_max_acks,
+	},
+	{
+		.procname	= "rx_mtu",
+		.data		= &rxrpc_rx_mtu,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)&rxrpc_rx_mtu_min,
+		.extra2		= (void *)&n_65535,
+	},
+	{
+		.procname	= "rx_jumbo_max",
+		.data		= &rxrpc_rx_jumbo_max,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)&rxrpc_jumbo_max,
+	},
+};
+
+int __init rxrpc_sysctl_init(void)
+{
+	rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc",
+						     rxrpc_sysctl_table);
+	if (!rxrpc_sysctl_reg_table)
+		return -ENOMEM;
+	return 0;
+}
+
+void rxrpc_sysctl_exit(void)
+{
+	if (rxrpc_sysctl_reg_table)
+		unregister_net_sysctl_table(rxrpc_sysctl_reg_table);
+}
diff --git a/net/rxrpc/tests/Makefile b/net/rxrpc/tests/Makefile
new file mode 100644
index 000000000..4f5100880
--- /dev/null
+++ b/net/rxrpc/tests/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_AF_RXRPC_KUNIT_TEST) += rxrpc_kunit.o
diff --git a/net/rxrpc/tests/rxrpc_kunit.c b/net/rxrpc/tests/rxrpc_kunit.c
new file mode 100644
index 000000000..95fd05a07
--- /dev/null
+++ b/net/rxrpc/tests/rxrpc_kunit.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Unit tests for RxRPC crypto functions
+ *
+ * Copyright 2026 Google LLC
+ */
+#include "../ar-internal.h"
+#include <crypto/des.h>
+#include <kunit/test.h>
+
+struct fcrypt_pcbc_testvec {
+	u8 key[FCRYPT_BSIZE];
+	u8 iv[FCRYPT_BSIZE];
+	const u8 *ptext; /* plaintext */
+	const u8 *ctext; /* ciphertext */
+	size_t nblocks; /* length of ptext and ctext in blocks */
+};
+
+/* FCrypt-PCBC test vectors */
+static const struct fcrypt_pcbc_testvec fcrypt_pcbc_testvecs[] = {
+	{
+		/* http://www.openafs.org/pipermail/openafs-devel/2000-December/005320.html */
+		.key = "\x00\x00\x00\x00\x00\x00\x00\x00",
+		.iv = "\x00\x00\x00\x00\x00\x00\x00\x00",
+		.ptext = "\x00\x00\x00\x00\x00\x00\x00\x00",
+		.ctext = "\x0E\x09\x00\xC7\x3E\xF7\xED\x41",
+		.nblocks = 1,
+	},
+	{
+		.key = "\x11\x44\x77\xAA\xDD\x00\x33\x66",
+		.iv = "\x00\x00\x00\x00\x00\x00\x00\x00",
+		.ptext = "\x12\x34\x56\x78\x9A\xBC\xDE\xF0",
+		.ctext = "\xD8\xED\x78\x74\x77\xEC\x06\x80",
+		.nblocks = 1,
+	},
+	{
+		/* From Arla */
+		.key = "\xf0\xe1\xd2\xc3\xb4\xa5\x96\x87",
+		.iv = "\xfe\xdc\xba\x98\x76\x54\x32\x10",
+		.ptext = "The quick brown fox jumps over the lazy dogs.\0\0",
+		.ctext = "\x00\xf0\x0e\x11\x75\xe6\x23\x82"
+			 "\xee\xac\x98\x62\x44\x51\xe4\x84"
+			 "\xc3\x59\xd8\xaa\x64\x60\xae\xf7"
+			 "\xd2\xd9\x13\x79\x72\xa3\x45\x03"
+			 "\x23\xb5\x62\xd7\x0c\xf5\x27\xd1"
+			 "\xf8\x91\x3c\xac\x44\x22\x92\xef",
+		.nblocks = 6,
+	},
+	{
+		.key = "\xfe\xdc\xba\x98\x76\x54\x32\x10",
+		.iv = "\xf0\xe1\xd2\xc3\xb4\xa5\x96\x87",
+		.ptext = "The quick brown fox jumps over the lazy dogs.\0\0",
+		.ctext = "\xca\x90\xf5\x9d\xcb\xd4\xd2\x3c"
+			 "\x01\x88\x7f\x3e\x31\x6e\x62\x9d"
+			 "\xd8\xe0\x57\xa3\x06\x3a\x42\x58"
+			 "\x2a\x28\xfe\x72\x52\x2f\xdd\xe0"
+			 "\x19\x89\x09\x1c\x2a\x8e\x8c\x94"
+			 "\xfc\xc7\x68\xe4\x88\xaa\xde\x0f",
+		.nblocks = 6,
+	}
+};
+
+static void test_fcrypt_pcbc(struct kunit *test)
+{
+	u8 data[48];
+
+	for (size_t i = 0; i < ARRAY_SIZE(fcrypt_pcbc_testvecs); i++) {
+		const struct fcrypt_pcbc_testvec *tv = &fcrypt_pcbc_testvecs[i];
+		const size_t nblocks = tv->nblocks;
+		const size_t len = nblocks * FCRYPT_BSIZE;
+		struct fcrypt_key key;
+
+		KUNIT_ASSERT_GE(test, sizeof(data), len);
+
+		fcrypt_preparekey(&key, tv->key);
+
+		/* out-of-place encryption */
+		fcrypt_pcbc_encrypt(&key, tv->iv, tv->ptext, data, nblocks);
+		KUNIT_ASSERT_MEMEQ(test, tv->ctext, data, len);
+
+		/* in-place encryption */
+		memcpy(data, tv->ptext, len);
+		fcrypt_pcbc_encrypt(&key, tv->iv, data, data, nblocks);
+		KUNIT_ASSERT_MEMEQ(test, tv->ctext, data, len);
+
+		/* out-of-place decryption */
+		fcrypt_pcbc_decrypt(&key, tv->iv, tv->ctext, data, nblocks);
+		KUNIT_ASSERT_MEMEQ(test, tv->ptext, data, len);
+
+		/* in-place decryption */
+		memcpy(data, tv->ctext, len);
+		fcrypt_pcbc_decrypt(&key, tv->iv, data, data, nblocks);
+		KUNIT_ASSERT_MEMEQ(test, tv->ptext, data, len);
+	}
+}
+
+static void test_des_pcbc(struct kunit *test)
+{
+	/* This was generated from the original pcbc(des) crypto API code. */
+	static const u8 expected_ptext[24] =
+		"\xc8\xe2\x3c\xdf\x80\x61\x8a\xad\xa5\x52\xb4\x20"
+		"\x74\x32\x1f\xe4\x2c\x15\x7d\x21\x57\xda\x3f\x31";
+	u8 key[8];
+	union {
+		__le64 w;
+		u8 b[8];
+	} iv;
+	u8 data[24];
+	struct des_ctx ctx;
+	int err;
+
+	for (int i = 0; i < 8; i++) {
+		key[i] = i;
+		iv.b[i] = 255 - i;
+	}
+	for (int i = 0; i < sizeof(data); i++)
+		data[i] = i;
+
+	err = des_expand_key(&ctx, key, sizeof(key));
+	KUNIT_ASSERT_EQ(test, 0, err);
+
+	des_pcbc_decrypt_inplace(&ctx, iv.w, data, sizeof(data));
+	KUNIT_ASSERT_MEMEQ(test, expected_ptext, data, sizeof(data));
+}
+
+static struct kunit_case rxrpc_test_cases[] = {
+	KUNIT_CASE(test_fcrypt_pcbc),
+	KUNIT_CASE(test_des_pcbc),
+	{},
+};
+
+static struct kunit_suite rxrpc_test_suite = {
+	.name = "rxrpc",
+	.test_cases = rxrpc_test_cases,
+};
+kunit_test_suite(rxrpc_test_suite);
+
+MODULE_DESCRIPTION("Unit tests for RxRPC crypto functions");
+MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");
+MODULE_LICENSE("GPL");
diff --git a/net/rxrpc/txbuf.c b/net/rxrpc/txbuf.c
new file mode 100644
index 000000000..55ef7a048
--- /dev/null
+++ b/net/rxrpc/txbuf.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC Tx data buffering.
+ *
+ * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include "ar-internal.h"
+
+static atomic_t rxrpc_txbuf_debug_ids;
+atomic_t rxrpc_nr_txbuf;
+
+/*
+ * Allocate and partially initialise a data transmission buffer.
+ */
+struct rxrpc_txbuf *rxrpc_alloc_data_txbuf(struct rxrpc_call *call, size_t data_size,
+					   size_t data_align, gfp_t gfp)
+{
+	struct rxrpc_txbuf *txb;
+	size_t total, doff, jsize = sizeof(struct rxrpc_jumbo_header);
+	void *buf;
+
+	txb = kzalloc_obj(*txb, gfp);
+	if (!txb)
+		return NULL;
+
+	/* We put a jumbo header in the buffer, but not a full wire header to
+	 * avoid delayed-corruption problems with zerocopy.
+	 */
+	doff = round_up(jsize, data_align);
+	total = doff + data_size;
+
+	data_align = umax(data_align, L1_CACHE_BYTES);
+	mutex_lock(&call->conn->tx_data_alloc_lock);
+	buf = page_frag_alloc_align(&call->conn->tx_data_alloc, total, gfp,
+				    data_align);
+	mutex_unlock(&call->conn->tx_data_alloc_lock);
+	if (!buf) {
+		kfree(txb);
+		return NULL;
+	}
+
+	refcount_set(&txb->ref, 1);
+	txb->call_debug_id	= call->debug_id;
+	txb->debug_id		= atomic_inc_return(&rxrpc_txbuf_debug_ids);
+	txb->alloc_size		= data_size;
+	txb->space		= data_size;
+	txb->offset		= 0;
+	txb->flags		= call->conn->out_clientflag;
+	txb->seq		= call->send_top + 1;
+	txb->data		= buf + doff;
+
+	trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 1,
+			  rxrpc_txbuf_alloc_data);
+
+	atomic_inc(&rxrpc_nr_txbuf);
+	return txb;
+}
+
+void rxrpc_see_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what)
+{
+	int r = refcount_read(&txb->ref);
+
+	trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, r, what);
+}
+
+static void rxrpc_free_txbuf(struct rxrpc_txbuf *txb)
+{
+	trace_rxrpc_txbuf(txb->debug_id, txb->call_debug_id, txb->seq, 0,
+			  rxrpc_txbuf_free);
+	if (txb->data)
+		page_frag_free(txb->data);
+	kfree(txb);
+	atomic_dec(&rxrpc_nr_txbuf);
+}
+
+void rxrpc_put_txbuf(struct rxrpc_txbuf *txb, enum rxrpc_txbuf_trace what)
+{
+	unsigned int debug_id, call_debug_id;
+	rxrpc_seq_t seq;
+	bool dead;
+	int r;
+
+	if (txb) {
+		debug_id = txb->debug_id;
+		call_debug_id = txb->call_debug_id;
+		seq = txb->seq;
+		dead = __refcount_dec_and_test(&txb->ref, &r);
+		trace_rxrpc_txbuf(debug_id, call_debug_id, seq, r - 1, what);
+		if (dead)
+			rxrpc_free_txbuf(txb);
+	}
+}
diff --git a/net/rxrpc/utils.c b/net/rxrpc/utils.c
new file mode 100644
index 000000000..2e4b9d86e
--- /dev/null
+++ b/net/rxrpc/utils.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Utility routines
+ *
+ * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include "ar-internal.h"
+
+/*
+ * Fill out a peer address from a socket buffer containing a packet.
+ */
+int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *srx, struct sk_buff *skb)
+{
+	memset(srx, 0, sizeof(*srx));
+
+	switch (ntohs(skb->protocol)) {
+	case ETH_P_IP:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin);
+		srx->transport.sin.sin_family = AF_INET;
+		srx->transport.sin.sin_port = udp_hdr(skb)->source;
+		srx->transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+		return 0;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+	case ETH_P_IPV6:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin6);
+		srx->transport.sin6.sin6_family = AF_INET6;
+		srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
+		srx->transport.sin6.sin6_addr = ipv6_hdr(skb)->saddr;
+		return 0;
+#endif
+
+	default:
+		pr_warn_ratelimited("AF_RXRPC: Unknown eth protocol %u\n",
+				    ntohs(skb->protocol));
+		return -EAFNOSUPPORT;
+	}
+}