ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

17 files changed, 13510 insertions, 0 deletions

diff --git a/net/can/Kconfig b/net/can/Kconfig
new file mode 100644
index 000000000..abbb4be7a
--- /dev/null
+++ b/net/can/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Controller Area Network (CAN) network layer core configuration
+#
+
+menuconfig CAN
+	tristate "CAN bus subsystem support"
+	select SKB_EXTENSIONS
+	help
+	  Controller Area Network (CAN) is a slow (up to 1Mbit/s) serial
+	  communications protocol. Development of the CAN bus started in
+	  1983 at Robert Bosch GmbH, and the protocol was officially
+	  released in 1986. The CAN bus was originally mainly for automotive,
+	  but is now widely used in marine (NMEA2000), industrial, and medical
+	  applications. More information on the CAN network protocol family
+	  PF_CAN is contained in <Documentation/networking/can.rst>.
+
+	  If you want CAN support you should say Y here and also to the
+	  specific driver for your controller(s) under the Network device
+	  support section.
+
+if CAN
+
+config CAN_RAW
+	tristate "Raw CAN Protocol (raw access with CAN-ID filtering)"
+	default y
+	help
+	  The raw CAN protocol option offers access to the CAN bus via
+	  the BSD socket API. You probably want to use the raw socket in
+	  most cases where no higher level protocol is being used. The raw
+	  socket has several filter options e.g. ID masking / error frames.
+	  To receive/send raw CAN messages, use AF_CAN with protocol CAN_RAW.
+
+config CAN_BCM
+	tristate "Broadcast Manager CAN Protocol (with content filtering)"
+	default y
+	help
+	  The Broadcast Manager offers content filtering, timeout monitoring,
+	  sending of RTR frames, and cyclic CAN messages without permanent user
+	  interaction. The BCM can be 'programmed' via the BSD socket API and
+	  informs you on demand e.g. only on content updates / timeouts.
+	  You probably want to use the bcm socket in most cases where cyclic
+	  CAN messages are used on the bus (e.g. in automotive environments).
+	  To use the Broadcast Manager, use AF_CAN with protocol CAN_BCM.
+
+config CAN_GW
+	tristate "CAN Gateway/Router (with netlink configuration)"
+	default y
+	help
+	  The CAN Gateway/Router is used to route (and modify) CAN frames.
+	  It is based on the PF_CAN core infrastructure for msg filtering and
+	  msg sending and can optionally modify routed CAN frames on the fly.
+	  CAN frames can be routed between CAN network interfaces (one hop).
+	  They can be modified with AND/OR/XOR/SET operations as configured
+	  by the netlink configuration interface known e.g. from iptables.
+
+source "net/can/j1939/Kconfig"
+
+config CAN_ISOTP
+	tristate "ISO 15765-2 CAN transport protocol"
+	help
+	  CAN Transport Protocols offer support for segmented Point-to-Point
+	  communication between CAN nodes via two defined CAN Identifiers.
+	  This protocol driver implements segmented data transfers for CAN CC
+	  (aka Classical CAN, CAN 2.0B) and CAN FD frame types which were
+	  introduced with ISO 15765-2:2016.
+	  As CAN frames can only transport a small amount of data bytes
+	  (max. 8 bytes for CAN CC and max. 64 bytes for CAN FD) this
+	  segmentation is needed to transport longer Protocol Data Units (PDU)
+	  as needed e.g. for vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN
+	  traffic.
+
+endif
diff --git a/net/can/Makefile b/net/can/Makefile
new file mode 100644
index 000000000..58f2c31c1
--- /dev/null
+++ b/net/can/Makefile
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+#  Makefile for the Linux Controller Area Network core.
+#
+
+obj-$(CONFIG_CAN)	+= can.o
+can-y			:= af_can.o
+can-$(CONFIG_PROC_FS)	+= proc.o
+
+obj-$(CONFIG_CAN_RAW)	+= can-raw.o
+can-raw-y		:= raw.o
+
+obj-$(CONFIG_CAN_BCM)	+= can-bcm.o
+can-bcm-y		:= bcm.o
+
+obj-$(CONFIG_CAN_GW)	+= can-gw.o
+can-gw-y		:= gw.o
+
+obj-$(CONFIG_CAN_J1939)	+= j1939/
+
+obj-$(CONFIG_CAN_ISOTP)	+= can-isotp.o
+can-isotp-y		:= isotp.o
diff --git a/net/can/af_can.c b/net/can/af_can.c
new file mode 100644
index 000000000..7bc86b176
--- /dev/null
+++ b/net/can/af_can.c
@@ -0,0 +1,932 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* af_can.c - Protocol family CAN core module
+ *            (used by different CAN protocol modules)
+ *
+ * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/uaccess.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/can-ml.h>
+#include <linux/ratelimit.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "af_can.h"
+
+MODULE_DESCRIPTION("Controller Area Network PF_CAN core");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>, "
+	      "Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+
+MODULE_ALIAS_NETPROTO(PF_CAN);
+
+static int stats_timer __read_mostly = 1;
+module_param(stats_timer, int, 0444);
+MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
+
+static struct kmem_cache *rcv_cache __read_mostly;
+
+/* table of registered CAN protocols */
+static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly;
+static DEFINE_MUTEX(proto_tab_lock);
+
+static atomic_t skbcounter = ATOMIC_INIT(0);
+
+/* af_can socket functions */
+
+void can_sock_destruct(struct sock *sk)
+{
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_queue_purge(&sk->sk_error_queue);
+}
+EXPORT_SYMBOL(can_sock_destruct);
+
+static const struct can_proto *can_get_proto(int protocol)
+{
+	const struct can_proto *cp;
+
+	rcu_read_lock();
+	cp = rcu_dereference(proto_tab[protocol]);
+	if (cp && !try_module_get(cp->prot->owner))
+		cp = NULL;
+	rcu_read_unlock();
+
+	return cp;
+}
+
+static inline void can_put_proto(const struct can_proto *cp)
+{
+	module_put(cp->prot->owner);
+}
+
+static int can_create(struct net *net, struct socket *sock, int protocol,
+		      int kern)
+{
+	struct sock *sk;
+	const struct can_proto *cp;
+	int err = 0;
+
+	sock->state = SS_UNCONNECTED;
+
+	if (protocol < 0 || protocol >= CAN_NPROTO)
+		return -EINVAL;
+
+	cp = can_get_proto(protocol);
+
+#ifdef CONFIG_MODULES
+	if (!cp) {
+		/* try to load protocol module if kernel is modular */
+
+		err = request_module("can-proto-%d", protocol);
+
+		/* In case of error we only print a message but don't
+		 * return the error code immediately.  Below we will
+		 * return -EPROTONOSUPPORT
+		 */
+		if (err)
+			pr_err_ratelimited("can: request_module (can-proto-%d) failed.\n",
+					   protocol);
+
+		cp = can_get_proto(protocol);
+	}
+#endif
+
+	/* check for available protocol and correct usage */
+
+	if (!cp)
+		return -EPROTONOSUPPORT;
+
+	if (cp->type != sock->type) {
+		err = -EPROTOTYPE;
+		goto errout;
+	}
+
+	sock->ops = cp->ops;
+
+	sk = sk_alloc(net, PF_CAN, GFP_KERNEL, cp->prot, kern);
+	if (!sk) {
+		err = -ENOMEM;
+		goto errout;
+	}
+
+	sock_init_data(sock, sk);
+	sk->sk_destruct = can_sock_destruct;
+
+	if (sk->sk_prot->init)
+		err = sk->sk_prot->init(sk);
+
+	if (err) {
+		/* release sk on errors */
+		sock_orphan(sk);
+		sock_put(sk);
+		sock->sk = NULL;
+	} else {
+		sock_prot_inuse_add(net, sk->sk_prot, 1);
+	}
+
+ errout:
+	can_put_proto(cp);
+	return err;
+}
+
+/* af_can tx path */
+
+/**
+ * can_send - transmit a CAN frame (optional with local loopback)
+ * @skb: pointer to socket buffer with CAN frame in data section
+ * @loop: loopback for listeners on local CAN sockets (recommended default!)
+ *
+ * Due to the loopback this routine must not be called from hardirq context.
+ *
+ * Return:
+ *  0 on success
+ *  -ENETDOWN when the selected interface is down
+ *  -ENOBUFS on full driver queue (see net_xmit_errno())
+ *  -ENOMEM when local loopback failed at calling skb_clone()
+ *  -EPERM when trying to send on a non-CAN interface
+ *  -EMSGSIZE CAN frame size is bigger than CAN interface MTU
+ *  -EINVAL when the skb->data does not contain a valid CAN frame
+ */
+int can_send(struct sk_buff *skb, int loop)
+{
+	struct sk_buff *newskb = NULL;
+	struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
+	int err = -EINVAL;
+
+	if (can_is_canxl_skb(skb)) {
+		skb->protocol = htons(ETH_P_CANXL);
+	} else if (can_is_can_skb(skb)) {
+		skb->protocol = htons(ETH_P_CAN);
+	} else if (can_is_canfd_skb(skb)) {
+		struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+		skb->protocol = htons(ETH_P_CANFD);
+
+		/* set CAN FD flag for CAN FD frames by default */
+		cfd->flags |= CANFD_FDF;
+	} else {
+		goto inval_skb;
+	}
+
+	/* Make sure the CAN frame can pass the selected CAN netdevice. */
+	if (unlikely(skb->len > READ_ONCE(skb->dev->mtu))) {
+		err = -EMSGSIZE;
+		goto inval_skb;
+	}
+
+	if (unlikely(skb->dev->type != ARPHRD_CAN)) {
+		err = -EPERM;
+		goto inval_skb;
+	}
+
+	if (unlikely(!(skb->dev->flags & IFF_UP))) {
+		err = -ENETDOWN;
+		goto inval_skb;
+	}
+
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	if (loop) {
+		/* local loopback of sent CAN frames */
+
+		/* indication for the CAN driver: do loopback */
+		skb->pkt_type = PACKET_LOOPBACK;
+
+		/* The reference to the originating sock may be required
+		 * by the receiving socket to check whether the frame is
+		 * its own. Example: can_raw sockopt CAN_RAW_RECV_OWN_MSGS
+		 * Therefore we have to ensure that skb->sk remains the
+		 * reference to the originating sock by restoring skb->sk
+		 * after each skb_clone() or skb_orphan() usage.
+		 */
+
+		if (!(skb->dev->flags & IFF_ECHO)) {
+			/* If the interface is not capable to do loopback
+			 * itself, we do it here.
+			 */
+			newskb = skb_clone(skb, GFP_ATOMIC);
+			if (!newskb) {
+				kfree_skb(skb);
+				return -ENOMEM;
+			}
+
+			can_skb_set_owner(newskb, skb->sk);
+			newskb->ip_summed = CHECKSUM_UNNECESSARY;
+			newskb->pkt_type = PACKET_BROADCAST;
+		}
+	} else {
+		/* indication for the CAN driver: no loopback required */
+		skb->pkt_type = PACKET_HOST;
+	}
+
+	/* send to netdevice */
+	err = dev_queue_xmit(skb);
+	if (err > 0)
+		err = net_xmit_errno(err);
+
+	if (err) {
+		kfree_skb(newskb);
+		return err;
+	}
+
+	if (newskb)
+		netif_rx(newskb);
+
+	/* update statistics */
+	atomic_long_inc(&pkg_stats->tx_frames);
+	atomic_long_inc(&pkg_stats->tx_frames_delta);
+
+	return 0;
+
+inval_skb:
+	kfree_skb(skb);
+	return err;
+}
+EXPORT_SYMBOL(can_send);
+
+/* af_can rx path */
+
+static struct can_dev_rcv_lists *can_dev_rcv_lists_find(struct net *net,
+							struct net_device *dev)
+{
+	if (dev) {
+		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+		return &can_ml->dev_rcv_lists;
+	} else {
+		return net->can.rx_alldev_list;
+	}
+}
+
+/**
+ * effhash - hash function for 29 bit CAN identifier reduction
+ * @can_id: 29 bit CAN identifier
+ *
+ * Description:
+ *  To reduce the linear traversal in one linked list of _single_ EFF CAN
+ *  frame subscriptions the 29 bit identifier is mapped to 10 bits.
+ *  (see CAN_EFF_RCV_HASH_BITS definition)
+ *
+ * Return:
+ *  Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
+ */
+static unsigned int effhash(canid_t can_id)
+{
+	unsigned int hash;
+
+	hash = can_id;
+	hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
+	hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);
+
+	return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
+}
+
+/**
+ * can_rcv_list_find - determine optimal filterlist inside device filter struct
+ * @can_id: pointer to CAN identifier of a given can_filter
+ * @mask: pointer to CAN mask of a given can_filter
+ * @dev_rcv_lists: pointer to the device filter struct
+ *
+ * Description:
+ *  Returns the optimal filterlist to reduce the filter handling in the
+ *  receive path. This function is called by service functions that need
+ *  to register or unregister a can_filter in the filter lists.
+ *
+ *  A filter matches in general, when
+ *
+ *          <received_can_id> & mask == can_id & mask
+ *
+ *  so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe
+ *  relevant bits for the filter.
+ *
+ *  The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
+ *  filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
+ *  frames there is a special filterlist and a special rx path filter handling.
+ *
+ * Return:
+ *  Pointer to optimal filterlist for the given can_id/mask pair.
+ *  Consistency checked mask.
+ *  Reduced can_id to have a preprocessed filter compare value.
+ */
+static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
+					    struct can_dev_rcv_lists *dev_rcv_lists)
+{
+	canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
+
+	/* filter for error message frames in extra filterlist */
+	if (*mask & CAN_ERR_FLAG) {
+		/* clear CAN_ERR_FLAG in filter entry */
+		*mask &= CAN_ERR_MASK;
+		return &dev_rcv_lists->rx[RX_ERR];
+	}
+
+	/* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */
+
+#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+	/* ensure valid values in can_mask for 'SFF only' frame filtering */
+	if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG))
+		*mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS);
+
+	/* reduce condition testing at receive time */
+	*can_id &= *mask;
+
+	/* inverse can_id/can_mask filter */
+	if (inv)
+		return &dev_rcv_lists->rx[RX_INV];
+
+	/* mask == 0 => no condition testing at receive time */
+	if (!(*mask))
+		return &dev_rcv_lists->rx[RX_ALL];
+
+	/* extra filterlists for the subscription of a single non-RTR can_id */
+	if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) &&
+	    !(*can_id & CAN_RTR_FLAG)) {
+		if (*can_id & CAN_EFF_FLAG) {
+			if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS))
+				return &dev_rcv_lists->rx_eff[effhash(*can_id)];
+		} else {
+			if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS))
+				return &dev_rcv_lists->rx_sff[*can_id];
+		}
+	}
+
+	/* default: filter via can_id/can_mask */
+	return &dev_rcv_lists->rx[RX_FIL];
+}
+
+/**
+ * can_rx_register - subscribe CAN frames from a specific interface
+ * @net: the applicable net namespace
+ * @dev: pointer to netdevice (NULL => subscribe from 'all' CAN devices list)
+ * @can_id: CAN identifier (see description)
+ * @mask: CAN mask (see description)
+ * @func: callback function on filter match
+ * @data: returned parameter for callback function
+ * @ident: string for calling module identification
+ * @sk: socket pointer (might be NULL)
+ *
+ * Description:
+ *  Invokes the callback function with the received sk_buff and the given
+ *  parameter 'data' on a matching receive filter. A filter matches, when
+ *
+ *          <received_can_id> & mask == can_id & mask
+ *
+ *  The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
+ *  filter for error message frames (CAN_ERR_FLAG bit set in mask).
+ *
+ *  The provided pointer to the sk_buff is guaranteed to be valid as long as
+ *  the callback function is running. The callback function must *not* free
+ *  the given sk_buff while processing it's task. When the given sk_buff is
+ *  needed after the end of the callback function it must be cloned inside
+ *  the callback function with skb_clone().
+ *
+ * Return:
+ *  0 on success
+ *  -ENOMEM on missing cache mem to create subscription entry
+ *  -ENODEV unknown device
+ */
+int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
+		    canid_t mask, void (*func)(struct sk_buff *, void *),
+		    void *data, char *ident, struct sock *sk)
+{
+	struct receiver *rcv;
+	struct hlist_head *rcv_list;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+
+	/* insert new receiver  (dev,canid,mask) -> (func,data) */
+
+	if (dev && (dev->type != ARPHRD_CAN || !can_get_ml_priv(dev)))
+		return -ENODEV;
+
+	if (dev && !net_eq(net, dev_net(dev)))
+		return -ENODEV;
+
+	rcv = kmem_cache_alloc(rcv_cache, GFP_KERNEL);
+	if (!rcv)
+		return -ENOMEM;
+
+	spin_lock_bh(&net->can.rcvlists_lock);
+
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
+
+	rcv->can_id = can_id;
+	rcv->mask = mask;
+	atomic_long_set(&rcv->matches, 0);
+	rcv->func = func;
+	rcv->data = data;
+	rcv->ident = ident;
+	rcv->sk = sk;
+
+	hlist_add_head_rcu(&rcv->list, rcv_list);
+	dev_rcv_lists->entries++;
+
+	rcv_lists_stats->rcv_entries++;
+	rcv_lists_stats->rcv_entries_max = max(rcv_lists_stats->rcv_entries_max,
+					       rcv_lists_stats->rcv_entries);
+	spin_unlock_bh(&net->can.rcvlists_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(can_rx_register);
+
+/* can_rx_delete_receiver - rcu callback for single receiver entry removal */
+static void can_rx_delete_receiver(struct rcu_head *rp)
+{
+	struct receiver *rcv = container_of(rp, struct receiver, rcu);
+	struct sock *sk = rcv->sk;
+
+	kmem_cache_free(rcv_cache, rcv);
+	if (sk)
+		sock_put(sk);
+}
+
+/**
+ * can_rx_unregister - unsubscribe CAN frames from a specific interface
+ * @net: the applicable net namespace
+ * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
+ * @can_id: CAN identifier
+ * @mask: CAN mask
+ * @func: callback function on filter match
+ * @data: returned parameter for callback function
+ *
+ * Description:
+ *  Removes subscription entry depending on given (subscription) values.
+ */
+void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
+		       canid_t mask, void (*func)(struct sk_buff *, void *),
+		       void *data)
+{
+	struct receiver *rcv = NULL;
+	struct hlist_head *rcv_list;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+
+	if (dev && dev->type != ARPHRD_CAN)
+		return;
+
+	if (dev && !net_eq(net, dev_net(dev)))
+		return;
+
+	spin_lock_bh(&net->can.rcvlists_lock);
+
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	rcv_list = can_rcv_list_find(&can_id, &mask, dev_rcv_lists);
+
+	/* Search the receiver list for the item to delete.  This should
+	 * exist, since no receiver may be unregistered that hasn't
+	 * been registered before.
+	 */
+	hlist_for_each_entry_rcu(rcv, rcv_list, list) {
+		if (rcv->can_id == can_id && rcv->mask == mask &&
+		    rcv->func == func && rcv->data == data)
+			break;
+	}
+
+	/* Check for bugs in CAN protocol implementations using af_can.c:
+	 * 'rcv' will be NULL if no matching list item was found for removal.
+	 * As this case may potentially happen when closing a socket while
+	 * the notifier for removing the CAN netdev is running we just print
+	 * a warning here.
+	 */
+	if (!rcv) {
+		pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X\n",
+			DNAME(dev), can_id, mask);
+		goto out;
+	}
+
+	hlist_del_rcu(&rcv->list);
+	dev_rcv_lists->entries--;
+
+	if (rcv_lists_stats->rcv_entries > 0)
+		rcv_lists_stats->rcv_entries--;
+
+ out:
+	spin_unlock_bh(&net->can.rcvlists_lock);
+
+	/* schedule the receiver item for deletion */
+	if (rcv) {
+		if (rcv->sk)
+			sock_hold(rcv->sk);
+		call_rcu(&rcv->rcu, can_rx_delete_receiver);
+	}
+}
+EXPORT_SYMBOL(can_rx_unregister);
+
+static inline void deliver(struct sk_buff *skb, struct receiver *rcv)
+{
+	rcv->func(skb, rcv->data);
+	atomic_long_inc(&rcv->matches);
+}
+
+static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb)
+{
+	struct receiver *rcv;
+	int matches = 0;
+	struct can_frame *cf = (struct can_frame *)skb->data;
+	canid_t can_id = cf->can_id;
+
+	if (dev_rcv_lists->entries == 0)
+		return 0;
+
+	if (can_id & CAN_ERR_FLAG) {
+		/* check for error message frame entries only */
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) {
+			if (can_id & rcv->mask) {
+				deliver(skb, rcv);
+				matches++;
+			}
+		}
+		return matches;
+	}
+
+	/* check for unfiltered entries */
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) {
+		deliver(skb, rcv);
+		matches++;
+	}
+
+	/* check for can_id/mask entries */
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) {
+		if ((can_id & rcv->mask) == rcv->can_id) {
+			deliver(skb, rcv);
+			matches++;
+		}
+	}
+
+	/* check for inverted can_id/mask entries */
+	hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) {
+		if ((can_id & rcv->mask) != rcv->can_id) {
+			deliver(skb, rcv);
+			matches++;
+		}
+	}
+
+	/* check filterlists for single non-RTR can_ids */
+	if (can_id & CAN_RTR_FLAG)
+		return matches;
+
+	if (can_id & CAN_EFF_FLAG) {
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {
+			if (rcv->can_id == can_id) {
+				deliver(skb, rcv);
+				matches++;
+			}
+		}
+	} else {
+		can_id &= CAN_SFF_MASK;
+		hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) {
+			deliver(skb, rcv);
+			matches++;
+		}
+	}
+
+	return matches;
+}
+
+void can_set_skb_uid(struct sk_buff *skb)
+{
+	/* create non-zero unique skb identifier together with *skb */
+	while (!(skb->hash))
+		skb->hash = atomic_inc_return(&skbcounter);
+
+	skb->sw_hash = 1;
+}
+EXPORT_SYMBOL(can_set_skb_uid);
+
+static void can_receive(struct sk_buff *skb, struct net_device *dev)
+{
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct net *net = dev_net(dev);
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	int matches;
+
+	/* update statistics */
+	atomic_long_inc(&pkg_stats->rx_frames);
+	atomic_long_inc(&pkg_stats->rx_frames_delta);
+
+	can_set_skb_uid(skb);
+
+	rcu_read_lock();
+
+	/* deliver the packet to sockets listening on all devices */
+	matches = can_rcv_filter(net->can.rx_alldev_list, skb);
+
+	/* find receive list for this device */
+	dev_rcv_lists = can_dev_rcv_lists_find(net, dev);
+	matches += can_rcv_filter(dev_rcv_lists, skb);
+
+	rcu_read_unlock();
+
+	/* consume the skbuff allocated by the netdevice driver */
+	consume_skb(skb);
+
+	if (matches > 0) {
+		atomic_long_inc(&pkg_stats->matches);
+		atomic_long_inc(&pkg_stats->matches_delta);
+	}
+}
+
+static int can_rcv(struct sk_buff *skb, struct net_device *dev,
+		   struct packet_type *pt, struct net_device *orig_dev)
+{
+	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+		     !can_skb_ext_find(skb) || !can_is_can_skb(skb))) {
+		pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
+			     dev->type, skb->len);
+
+		kfree_skb_reason(skb, SKB_DROP_REASON_CAN_RX_INVALID_FRAME);
+		return NET_RX_DROP;
+	}
+
+	can_receive(skb, dev);
+	return NET_RX_SUCCESS;
+}
+
+static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
+		     struct packet_type *pt, struct net_device *orig_dev)
+{
+	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+		     !can_skb_ext_find(skb) || !can_is_canfd_skb(skb))) {
+		pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
+			     dev->type, skb->len);
+
+		kfree_skb_reason(skb, SKB_DROP_REASON_CANFD_RX_INVALID_FRAME);
+		return NET_RX_DROP;
+	}
+
+	can_receive(skb, dev);
+	return NET_RX_SUCCESS;
+}
+
+static int canxl_rcv(struct sk_buff *skb, struct net_device *dev,
+		     struct packet_type *pt, struct net_device *orig_dev)
+{
+	if (unlikely(dev->type != ARPHRD_CAN || !can_get_ml_priv(dev) ||
+		     !can_skb_ext_find(skb) || !can_is_canxl_skb(skb))) {
+		pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n",
+			     dev->type, skb->len);
+
+		kfree_skb_reason(skb, SKB_DROP_REASON_CANXL_RX_INVALID_FRAME);
+		return NET_RX_DROP;
+	}
+
+	can_receive(skb, dev);
+	return NET_RX_SUCCESS;
+}
+
+/* af_can protocol functions */
+
+/**
+ * can_proto_register - register CAN transport protocol
+ * @cp: pointer to CAN protocol structure
+ *
+ * Return:
+ *  0 on success
+ *  -EINVAL invalid (out of range) protocol number
+ *  -EBUSY  protocol already in use
+ *  -ENOBUF if proto_register() fails
+ */
+int can_proto_register(const struct can_proto *cp)
+{
+	int proto = cp->protocol;
+	int err = 0;
+
+	if (proto < 0 || proto >= CAN_NPROTO) {
+		pr_err("can: protocol number %d out of range\n", proto);
+		return -EINVAL;
+	}
+
+	err = proto_register(cp->prot, 0);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&proto_tab_lock);
+
+	if (rcu_access_pointer(proto_tab[proto])) {
+		pr_err("can: protocol %d already registered\n", proto);
+		err = -EBUSY;
+	} else {
+		RCU_INIT_POINTER(proto_tab[proto], cp);
+	}
+
+	mutex_unlock(&proto_tab_lock);
+
+	if (err < 0)
+		proto_unregister(cp->prot);
+
+	return err;
+}
+EXPORT_SYMBOL(can_proto_register);
+
+/**
+ * can_proto_unregister - unregister CAN transport protocol
+ * @cp: pointer to CAN protocol structure
+ */
+void can_proto_unregister(const struct can_proto *cp)
+{
+	int proto = cp->protocol;
+
+	mutex_lock(&proto_tab_lock);
+	BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
+	RCU_INIT_POINTER(proto_tab[proto], NULL);
+	mutex_unlock(&proto_tab_lock);
+
+	synchronize_rcu();
+
+	proto_unregister(cp->prot);
+}
+EXPORT_SYMBOL(can_proto_unregister);
+
+static int can_pernet_init(struct net *net)
+{
+	spin_lock_init(&net->can.rcvlists_lock);
+	net->can.rx_alldev_list = kzalloc_obj(*net->can.rx_alldev_list);
+	if (!net->can.rx_alldev_list)
+		goto out;
+	net->can.pkg_stats = kzalloc_obj(*net->can.pkg_stats);
+	if (!net->can.pkg_stats)
+		goto out_free_rx_alldev_list;
+	net->can.rcv_lists_stats = kzalloc_obj(*net->can.rcv_lists_stats);
+	if (!net->can.rcv_lists_stats)
+		goto out_free_pkg_stats;
+
+	if (IS_ENABLED(CONFIG_PROC_FS)) {
+		/* the statistics are updated every second (timer triggered) */
+		if (stats_timer) {
+			timer_setup(&net->can.stattimer, can_stat_update,
+				    0);
+			mod_timer(&net->can.stattimer,
+				  round_jiffies(jiffies + HZ));
+		}
+		net->can.pkg_stats->jiffies_init = jiffies;
+		can_init_proc(net);
+	}
+
+	return 0;
+
+ out_free_pkg_stats:
+	kfree(net->can.pkg_stats);
+ out_free_rx_alldev_list:
+	kfree(net->can.rx_alldev_list);
+ out:
+	return -ENOMEM;
+}
+
+static void can_pernet_exit(struct net *net)
+{
+	if (IS_ENABLED(CONFIG_PROC_FS)) {
+		can_remove_proc(net);
+		if (stats_timer)
+			timer_delete_sync(&net->can.stattimer);
+	}
+
+	kfree(net->can.rx_alldev_list);
+	kfree(net->can.pkg_stats);
+	kfree(net->can.rcv_lists_stats);
+}
+
+/* af_can module init/exit functions */
+
+static struct packet_type can_packet __read_mostly = {
+	.type = cpu_to_be16(ETH_P_CAN),
+	.func = can_rcv,
+};
+
+static struct packet_type canfd_packet __read_mostly = {
+	.type = cpu_to_be16(ETH_P_CANFD),
+	.func = canfd_rcv,
+};
+
+static struct packet_type canxl_packet __read_mostly = {
+	.type = cpu_to_be16(ETH_P_CANXL),
+	.func = canxl_rcv,
+};
+
+static const struct net_proto_family can_family_ops = {
+	.family = PF_CAN,
+	.create = can_create,
+	.owner  = THIS_MODULE,
+};
+
+static struct pernet_operations can_pernet_ops __read_mostly = {
+	.init = can_pernet_init,
+	.exit = can_pernet_exit,
+};
+
+static __init int can_init(void)
+{
+	int err;
+
+	/* check for correct padding to be able to use the structs similarly */
+	BUILD_BUG_ON(offsetof(struct can_frame, len) !=
+		     offsetof(struct canfd_frame, len) ||
+		     offsetof(struct can_frame, len) !=
+		     offsetof(struct canxl_frame, flags) ||
+		     offsetof(struct can_frame, data) !=
+		     offsetof(struct canfd_frame, data));
+
+	pr_info("can: controller area network core\n");
+
+	rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
+				      0, 0, NULL);
+	if (!rcv_cache)
+		return -ENOMEM;
+
+	err = register_pernet_subsys(&can_pernet_ops);
+	if (err)
+		goto out_pernet;
+
+	/* protocol register */
+	err = sock_register(&can_family_ops);
+	if (err)
+		goto out_sock;
+
+	dev_add_pack(&can_packet);
+	dev_add_pack(&canfd_packet);
+	dev_add_pack(&canxl_packet);
+
+	return 0;
+
+out_sock:
+	unregister_pernet_subsys(&can_pernet_ops);
+out_pernet:
+	kmem_cache_destroy(rcv_cache);
+
+	return err;
+}
+
+static __exit void can_exit(void)
+{
+	/* protocol unregister */
+	dev_remove_pack(&canxl_packet);
+	dev_remove_pack(&canfd_packet);
+	dev_remove_pack(&can_packet);
+	sock_unregister(PF_CAN);
+
+	unregister_pernet_subsys(&can_pernet_ops);
+
+	rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
+	kmem_cache_destroy(rcv_cache);
+}
+
+module_init(can_init);
+module_exit(can_exit);
diff --git a/net/can/af_can.h b/net/can/af_can.h
new file mode 100644
index 000000000..87887014f
--- /dev/null
+++ b/net/can/af_can.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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.
+ *
+ */
+
+#ifndef AF_CAN_H
+#define AF_CAN_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/can.h>
+
+/* af_can rx dispatcher structures */
+
+struct receiver {
+	struct hlist_node list;
+	canid_t can_id;
+	canid_t mask;
+	atomic_long_t matches;
+	void (*func)(struct sk_buff *skb, void *data);
+	void *data;
+	char *ident;
+	struct sock *sk;
+	struct rcu_head rcu;
+};
+
+/* statistic structures */
+
+/* can be reset e.g. by can_init_stats() */
+struct can_pkg_stats {
+	unsigned long jiffies_init;
+
+	atomic_long_t rx_frames;
+	atomic_long_t tx_frames;
+	atomic_long_t matches;
+
+	unsigned long total_rx_rate;
+	unsigned long total_tx_rate;
+	unsigned long total_rx_match_ratio;
+
+	unsigned long current_rx_rate;
+	unsigned long current_tx_rate;
+	unsigned long current_rx_match_ratio;
+
+	unsigned long max_rx_rate;
+	unsigned long max_tx_rate;
+	unsigned long max_rx_match_ratio;
+
+	atomic_long_t rx_frames_delta;
+	atomic_long_t tx_frames_delta;
+	atomic_long_t matches_delta;
+};
+
+/* persistent statistics */
+struct can_rcv_lists_stats {
+	unsigned long stats_reset;
+	unsigned long user_reset;
+	unsigned long rcv_entries;
+	unsigned long rcv_entries_max;
+};
+
+/* function prototypes for the CAN networklayer procfs (proc.c) */
+void can_init_proc(struct net *net);
+void can_remove_proc(struct net *net);
+void can_stat_update(struct timer_list *t);
+
+#endif /* AF_CAN_H */
diff --git a/net/can/bcm.c b/net/can/bcm.c
new file mode 100644
index 000000000..3d637a1e0
--- /dev/null
+++ b/net/can/bcm.c
@@ -0,0 +1,2215 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * bcm.c - Broadcast Manager to filter/send (cyclic) CAN content
+ *
+ * Copyright (c) 2002-2017 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/hrtimer.h>
+#include <linux/list.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/bcm.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <net/can.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+/*
+ * To send multiple CAN frame content within TX_SETUP or to filter
+ * CAN messages with multiplex index within RX_SETUP, the number of
+ * different filters is limited to 256 due to the one byte index value.
+ */
+#define MAX_NFRAMES 256
+
+/* limit timers to 400 days for sending/timeouts */
+#define BCM_TIMER_SEC_MAX (400 * 24 * 60 * 60)
+
+/* use of last_frames[index].flags */
+#define RX_LOCAL   0x10 /* frame was created on the local host */
+#define RX_OWN     0x20 /* frame was sent via the socket it was received on */
+#define RX_RECV    0x40 /* received data for this element */
+#define RX_THR     0x80 /* element not been sent due to throttle feature */
+#define BCM_CAN_FLAGS_MASK 0x0F /* to clean private flags after usage */
+
+/* get best masking value for can_rx_register() for a given single can_id */
+#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \
+		     (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
+		     (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
+
+MODULE_DESCRIPTION("PF_CAN broadcast manager protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+MODULE_ALIAS("can-proto-2");
+
+#define BCM_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
+
+static struct workqueue_struct *bcm_wq;
+
+/*
+ * easy access to the first 64 bit of can(fd)_frame payload. cp->data is
+ * 64 bit aligned so the offset has to be multiples of 8 which is ensured
+ * by the only callers in bcm_rx_cmp_to_index() bcm_rx_handler().
+ */
+static inline u64 get_u64(const struct canfd_frame *cp, int offset)
+{
+	return *(u64 *)(cp->data + offset);
+}
+
+struct bcm_op {
+	struct list_head list;
+	struct rcu_head rcu;
+	struct work_struct work;
+	int ifindex;
+	canid_t can_id;
+	u32 flags;
+	atomic_long_t frames_abs, frames_filtered;
+	struct bcm_timeval ival1, ival2;
+	struct hrtimer timer, thrtimer;
+	ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg;
+	int rx_ifindex;
+	int if_detected; /* first received ifindex in ANYDEV rx_op mode */
+	int cfsiz;
+	u32 count;
+	u32 nframes;
+	u32 currframe;
+	/* void pointers to arrays of struct can[fd]_frame */
+	void *frames;
+	void *last_frames;
+	struct canfd_frame sframe;
+	struct canfd_frame last_sframe;
+	struct sock *sk;
+	struct net_device *rx_reg_dev;
+	netdevice_tracker rx_reg_dev_tracker;
+	spinlock_t bcm_tx_lock; /* protect tx data and timer updates */
+	spinlock_t bcm_rx_update_lock; /* protect filter/timer data updates */
+};
+
+struct bcm_sock {
+	struct sock sk;
+	int bound;
+	int ifindex;
+	struct list_head notifier;
+	struct list_head rx_ops;
+	struct list_head tx_ops;
+	unsigned long dropped_usr_msgs;
+	struct proc_dir_entry *bcm_proc_read;
+	char procname [32]; /* inode number in decimal with \0 */
+};
+
+static LIST_HEAD(bcm_notifier_list);
+static DEFINE_SPINLOCK(bcm_notifier_lock);
+static struct bcm_sock *bcm_busy_notifier;
+
+/* Return pointer to store the extra msg flags for bcm_recvmsg().
+ * We use the space of one unsigned int beyond the 'struct sockaddr_can'
+ * in skb->cb.
+ */
+static inline unsigned int *bcm_flags(struct sk_buff *skb)
+{
+	/* return pointer after struct sockaddr_can */
+	return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
+}
+
+static inline struct bcm_sock *bcm_sk(const struct sock *sk)
+{
+	return (struct bcm_sock *)sk;
+}
+
+static inline ktime_t bcm_timeval_to_ktime(struct bcm_timeval tv)
+{
+	return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
+}
+
+/* check limitations for timeval provided by user */
+static bool bcm_is_invalid_tv(struct bcm_msg_head *msg_head)
+{
+	if ((msg_head->ival1.tv_sec < 0) ||
+	    (msg_head->ival1.tv_sec > BCM_TIMER_SEC_MAX) ||
+	    (msg_head->ival1.tv_usec < 0) ||
+	    (msg_head->ival1.tv_usec >= USEC_PER_SEC) ||
+	    (msg_head->ival2.tv_sec < 0) ||
+	    (msg_head->ival2.tv_sec > BCM_TIMER_SEC_MAX) ||
+	    (msg_head->ival2.tv_usec < 0) ||
+	    (msg_head->ival2.tv_usec >= USEC_PER_SEC))
+		return true;
+
+	return false;
+}
+
+#define CFSIZ(flags) ((flags & CAN_FD_FRAME) ? CANFD_MTU : CAN_MTU)
+#define OPSIZ sizeof(struct bcm_op)
+#define MHSIZ sizeof(struct bcm_msg_head)
+
+/*
+ * procfs functions
+ */
+#if IS_ENABLED(CONFIG_PROC_FS)
+static char *bcm_proc_getifname(struct net *net, char *result, int ifindex)
+{
+	struct net_device *dev;
+
+	if (!ifindex)
+		return "any";
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, ifindex);
+	if (dev)
+		strcpy(result, dev->name);
+	else
+		strcpy(result, "???");
+	rcu_read_unlock();
+
+	return result;
+}
+
+static int bcm_proc_show(struct seq_file *m, void *v)
+{
+	char ifname[IFNAMSIZ];
+	struct net *net = m->private;
+	struct sock *sk = (struct sock *)pde_data(m->file->f_inode);
+	struct bcm_sock *bo = bcm_sk(sk);
+	struct bcm_op *op;
+
+	seq_printf(m, ">>> socket %pK", sk->sk_socket);
+	seq_printf(m, " / sk %pK", sk);
+	seq_printf(m, " / bo %pK", bo);
+	seq_printf(m, " / dropped %lu", bo->dropped_usr_msgs);
+	seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
+	seq_printf(m, " <<<\n");
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(op, &bo->rx_ops, list) {
+
+		long reduction, frames_filtered, frames_abs;
+
+		frames_filtered = atomic_long_read(&op->frames_filtered);
+		frames_abs = atomic_long_read(&op->frames_abs);
+
+		/* print only active entries & prevent division by zero */
+		if (!frames_abs)
+			continue;
+
+		seq_printf(m, "rx_op: %03X %-5s ", op->can_id,
+			   bcm_proc_getifname(net, ifname, op->ifindex));
+
+		if (op->flags & CAN_FD_FRAME)
+			seq_printf(m, "(%u)", op->nframes);
+		else
+			seq_printf(m, "[%u]", op->nframes);
+
+		seq_printf(m, "%c ", (op->flags & RX_CHECK_DLC) ? 'd' : ' ');
+
+		if (op->kt_ival1)
+			seq_printf(m, "timeo=%lld ",
+				   (long long)ktime_to_us(op->kt_ival1));
+
+		if (op->kt_ival2)
+			seq_printf(m, "thr=%lld ",
+				   (long long)ktime_to_us(op->kt_ival2));
+
+		seq_printf(m, "# recv %ld (%ld) => reduction: ",
+			   frames_filtered, frames_abs);
+
+		reduction = 100 - (frames_filtered * 100) / frames_abs;
+
+		seq_printf(m, "%s%ld%%\n",
+			   (reduction == 100) ? "near " : "", reduction);
+	}
+
+	list_for_each_entry_rcu(op, &bo->tx_ops, list) {
+
+		seq_printf(m, "tx_op: %03X %s ", op->can_id,
+			   bcm_proc_getifname(net, ifname, op->ifindex));
+
+		if (op->flags & CAN_FD_FRAME)
+			seq_printf(m, "(%u) ", op->nframes);
+		else
+			seq_printf(m, "[%u] ", op->nframes);
+
+		if (op->kt_ival1)
+			seq_printf(m, "t1=%lld ",
+				   (long long)ktime_to_us(op->kt_ival1));
+
+		if (op->kt_ival2)
+			seq_printf(m, "t2=%lld ",
+				   (long long)ktime_to_us(op->kt_ival2));
+
+		seq_printf(m, "# sent %ld\n",
+			   atomic_long_read(&op->frames_abs));
+	}
+	seq_putc(m, '\n');
+
+	rcu_read_unlock();
+
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */
+
+static void bcm_update_rx_stats(struct bcm_op *op)
+{
+	/* prevent overflow of the reduction% calculation in bcm_proc_show() */
+	if (atomic_long_inc_return(&op->frames_abs) > LONG_MAX / 100) {
+		atomic_long_set(&op->frames_filtered, 0);
+		atomic_long_set(&op->frames_abs, 0);
+	}
+}
+
+static void bcm_update_tx_stats(struct bcm_op *op)
+{
+	/* tx_op has no reduction% calculation - use the full range and
+	 * just keep the displayed counter non-negative on overflow
+	 */
+	if (atomic_long_inc_return(&op->frames_abs) == LONG_MAX)
+		atomic_long_set(&op->frames_abs, 0);
+}
+
+/*
+ * bcm_can_tx - send the (next) CAN frame to the appropriate CAN interface
+ *              of the given bcm tx op
+ */
+static void bcm_can_tx(struct bcm_op *op, struct canfd_frame *cf)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct net_device *dev;
+	struct canfd_frame cframe;
+	bool cyclic = !cf;
+	unsigned int idx = 0;
+	int err;
+
+	/* no target device? => exit */
+	if (!op->ifindex)
+		return;
+
+	if (cyclic) {
+		/* read currframe under lock protection */
+		spin_lock_bh(&op->bcm_tx_lock);
+		idx = op->currframe;
+		memcpy(&cframe, op->frames + op->cfsiz * idx, op->cfsiz);
+		cf = &cframe;
+		spin_unlock_bh(&op->bcm_tx_lock);
+	}
+
+	dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
+	if (!dev) {
+		/* RFC: should this bcm_op remove itself here? */
+		return;
+	}
+
+	skb = alloc_skb(op->cfsiz, gfp_any());
+	if (!skb)
+		goto out;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		goto out;
+	}
+
+	csx->can_iif = dev->ifindex;
+
+	skb_put_data(skb, cf, op->cfsiz);
+
+	/* send with loopback */
+	skb->dev = dev;
+	can_skb_set_owner(skb, op->sk);
+	err = can_send(skb, 1);
+
+	/* update currframe and count under lock protection */
+	spin_lock_bh(&op->bcm_tx_lock);
+
+	if (!err)
+		bcm_update_tx_stats(op);
+
+	/* only advance the cyclic sequence if nothing reset currframe while
+	 * we were sending - a concurrent TX_RESET_MULTI_IDX means this
+	 * frame's bookkeeping belongs to a sequence that no longer exists
+	 */
+	if (!cyclic || op->currframe == idx) {
+		op->currframe++;
+
+		/* reached last frame? */
+		if (op->currframe >= op->nframes)
+			op->currframe = 0;
+
+		if (op->count > 0)
+			op->count--;
+	}
+
+	spin_unlock_bh(&op->bcm_tx_lock);
+out:
+	dev_put(dev);
+}
+
+/*
+ * bcm_send_to_user - send a BCM message to the userspace
+ *                    (consisting of bcm_msg_head + x CAN frames)
+ */
+static void bcm_send_to_user(struct bcm_op *op, struct bcm_msg_head *head,
+			     struct canfd_frame *frames, int has_timestamp)
+{
+	struct sk_buff *skb;
+	struct canfd_frame *firstframe;
+	struct sockaddr_can *addr;
+	struct sock *sk = op->sk;
+	unsigned int datalen = head->nframes * op->cfsiz;
+	unsigned int *pflags;
+	enum skb_drop_reason reason;
+
+	skb = alloc_skb(sizeof(*head) + datalen, gfp_any());
+	if (!skb)
+		return;
+
+	skb_put_data(skb, head, sizeof(*head));
+
+	/* ensure space for sockaddr_can and msg flags */
+	sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
+			       sizeof(unsigned int));
+
+	/* initialize msg flags */
+	pflags = bcm_flags(skb);
+	*pflags = 0;
+
+	if (head->nframes) {
+		/* CAN frames starting here */
+		firstframe = (struct canfd_frame *)skb_tail_pointer(skb);
+
+		skb_put_data(skb, frames, datalen);
+
+		/*
+		 * the BCM uses the flags-element of the canfd_frame
+		 * structure for internal purposes. This is only
+		 * relevant for updates that are generated by the
+		 * BCM, where nframes is 1
+		 */
+		if (head->nframes == 1) {
+			if (firstframe->flags & RX_LOCAL)
+				*pflags |= MSG_DONTROUTE;
+			if (firstframe->flags & RX_OWN)
+				*pflags |= MSG_CONFIRM;
+
+			firstframe->flags &= BCM_CAN_FLAGS_MASK;
+		}
+	}
+
+	if (has_timestamp) {
+		/* restore rx timestamp */
+		skb->tstamp = op->rx_stamp;
+	}
+
+	/*
+	 *  Put the datagram to the queue so that bcm_recvmsg() can
+	 *  get it from there.  We need to pass the interface index to
+	 *  bcm_recvmsg().  We pass a whole struct sockaddr_can in skb->cb
+	 *  containing the interface index.
+	 */
+
+	addr = (struct sockaddr_can *)skb->cb;
+	memset(addr, 0, sizeof(*addr));
+	addr->can_family  = AF_CAN;
+	addr->can_ifindex = op->rx_ifindex;
+
+	reason = sock_queue_rcv_skb_reason(sk, skb);
+	if (reason) {
+		struct bcm_sock *bo = bcm_sk(sk);
+
+		sk_skb_reason_drop(sk, skb, reason);
+		/* don't care about overflows in this statistic */
+		bo->dropped_usr_msgs++;
+	}
+}
+
+static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt)
+{
+	ktime_t ival;
+
+	spin_lock_bh(&op->bcm_tx_lock);
+
+	if (op->kt_ival1 && op->count)
+		ival = op->kt_ival1;
+	else if (op->kt_ival2) {
+		ival = op->kt_ival2;
+	} else {
+		spin_unlock_bh(&op->bcm_tx_lock);
+		return false;
+	}
+
+	spin_unlock_bh(&op->bcm_tx_lock);
+
+	hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival));
+	return true;
+}
+
+static void bcm_tx_start_timer(struct bcm_op *op)
+{
+	if (bcm_tx_set_expiry(op, &op->timer))
+		hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT);
+}
+
+/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */
+static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
+{
+	struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
+	struct bcm_msg_head msg_head;
+	bool tx_ival1, tx_ival2;
+
+	/* snapshot kt_ival1/kt_ival2/count under lock to avoid torn
+	 * ktime_t reads racing with concurrent bcm_tx_setup() updates
+	 */
+	spin_lock_bh(&op->bcm_tx_lock);
+	tx_ival1 = op->kt_ival1 && (op->count > 0);
+	tx_ival2 = !!op->kt_ival2;
+	spin_unlock_bh(&op->bcm_tx_lock);
+
+	if (tx_ival1) {
+		u32 flags, count;
+		struct bcm_timeval ival1, ival2;
+
+		bcm_can_tx(op, NULL);
+
+		/* snapshot variables under lock to avoid torn reads racing
+		 * with concurrent bcm_tx_setup() updates
+		 */
+		spin_lock_bh(&op->bcm_tx_lock);
+		flags = op->flags;
+		count = op->count;
+		ival1 = op->ival1;
+		ival2 = op->ival2;
+		spin_unlock_bh(&op->bcm_tx_lock);
+
+		if (!count && (flags & TX_COUNTEVT)) {
+			/* create notification to user */
+			memset(&msg_head, 0, sizeof(msg_head));
+			msg_head.opcode  = TX_EXPIRED;
+			msg_head.flags   = flags;
+			msg_head.count   = count;
+			msg_head.ival1   = ival1;
+			msg_head.ival2   = ival2;
+			msg_head.can_id  = op->can_id;
+			msg_head.nframes = 0;
+
+			bcm_send_to_user(op, &msg_head, NULL, 0);
+		}
+
+	} else if (tx_ival2) {
+		bcm_can_tx(op, NULL);
+	}
+
+	return bcm_tx_set_expiry(op, &op->timer) ?
+		HRTIMER_RESTART : HRTIMER_NORESTART;
+}
+
+/*
+ * bcm_rx_changed - create a RX_CHANGED notification due to changed content
+ */
+static void bcm_rx_changed(struct bcm_op *op, struct canfd_frame *data)
+{
+	struct bcm_msg_head head;
+
+	/* update statistics (frames_filtered <= frames_abs) */
+	if (atomic_long_read(&op->frames_abs))
+		atomic_long_inc(&op->frames_filtered);
+
+	/* this element is not throttled anymore */
+	data->flags &= ~RX_THR;
+
+	memset(&head, 0, sizeof(head));
+	head.opcode  = RX_CHANGED;
+	head.flags   = op->flags;
+	head.count   = op->count;
+	head.ival1   = op->ival1;
+	head.ival2   = op->ival2;
+	head.can_id  = op->can_id;
+	head.nframes = 1;
+
+	bcm_send_to_user(op, &head, data, 1);
+}
+
+/*
+ * bcm_rx_update_and_send - process a detected relevant receive content change
+ *                          1. update the last received data
+ *                          2. send a notification to the user (if possible)
+ */
+static void bcm_rx_update_and_send(struct bcm_op *op,
+				   struct canfd_frame *lastdata,
+				   const struct canfd_frame *rxdata,
+				   unsigned char traffic_flags)
+{
+	memcpy(lastdata, rxdata, op->cfsiz);
+
+	/* mark as used and throttled by default */
+	lastdata->flags |= (RX_RECV|RX_THR);
+
+	/* add own/local/remote traffic flags */
+	lastdata->flags |= traffic_flags;
+
+	/* throttling mode inactive ? */
+	if (!op->kt_ival2) {
+		/* send RX_CHANGED to the user immediately */
+		bcm_rx_changed(op, lastdata);
+		return;
+	}
+
+	/* with active throttling timer we are just done here */
+	if (hrtimer_active(&op->thrtimer))
+		return;
+
+	/* first reception with enabled throttling mode */
+	if (!op->kt_lastmsg)
+		goto rx_changed_settime;
+
+	/* got a second frame inside a potential throttle period? */
+	if (ktime_us_delta(ktime_get(), op->kt_lastmsg) <
+	    ktime_to_us(op->kt_ival2)) {
+		/* do not send the saved data - only start throttle timer */
+		hrtimer_start(&op->thrtimer,
+			      ktime_add(op->kt_lastmsg, op->kt_ival2),
+			      HRTIMER_MODE_ABS_SOFT);
+		return;
+	}
+
+	/* the gap was that big, that throttling was not needed here */
+rx_changed_settime:
+	bcm_rx_changed(op, lastdata);
+	op->kt_lastmsg = ktime_get();
+}
+
+/*
+ * bcm_rx_cmp_to_index - (bit)compares the currently received data to formerly
+ *                       received data stored in op->last_frames[]
+ */
+static void bcm_rx_cmp_to_index(struct bcm_op *op, unsigned int index,
+				const struct canfd_frame *rxdata,
+				unsigned char traffic_flags)
+{
+	struct canfd_frame *cf = op->frames + op->cfsiz * index;
+	struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
+	int i;
+
+	/*
+	 * no one uses the MSBs of flags for comparison,
+	 * so we use it here to detect the first time of reception
+	 */
+
+	if (!(lcf->flags & RX_RECV)) {
+		/* received data for the first time => send update to user */
+		bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
+		return;
+	}
+
+	/* do a real check in CAN frame data section */
+	for (i = 0; i < rxdata->len; i += 8) {
+		if ((get_u64(cf, i) & get_u64(rxdata, i)) !=
+		    (get_u64(cf, i) & get_u64(lcf, i))) {
+			bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
+			return;
+		}
+	}
+
+	if (op->flags & RX_CHECK_DLC) {
+		/* do a real check in CAN frame length */
+		if (rxdata->len != lcf->len) {
+			bcm_rx_update_and_send(op, lcf, rxdata, traffic_flags);
+			return;
+		}
+	}
+}
+
+/*
+ * bcm_rx_starttimer - enable timeout monitoring for CAN frame reception
+ */
+static void bcm_rx_starttimer(struct bcm_op *op)
+{
+	if (op->flags & RX_NO_AUTOTIMER)
+		return;
+
+	if (op->kt_ival1)
+		hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT);
+}
+
+/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */
+static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer)
+{
+	struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer);
+	struct bcm_msg_head msg_head;
+
+	spin_lock_bh(&op->bcm_rx_update_lock);
+
+	/* if user wants to be informed, when cyclic CAN-Messages come back */
+	if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) {
+		/* clear received CAN frames to indicate 'nothing received' */
+		memset(op->last_frames, 0, op->nframes * op->cfsiz);
+	}
+
+	/* create notification to user */
+	memset(&msg_head, 0, sizeof(msg_head));
+	msg_head.opcode  = RX_TIMEOUT;
+	msg_head.flags   = op->flags;
+	msg_head.count   = op->count;
+	msg_head.ival1   = op->ival1;
+	msg_head.ival2   = op->ival2;
+	msg_head.can_id  = op->can_id;
+	msg_head.nframes = 0;
+
+	spin_unlock_bh(&op->bcm_rx_update_lock);
+
+	bcm_send_to_user(op, &msg_head, NULL, 0);
+
+	return HRTIMER_NORESTART;
+}
+
+/*
+ * bcm_rx_do_flush - helper for bcm_rx_thr_flush
+ */
+static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index)
+{
+	struct canfd_frame *lcf = op->last_frames + op->cfsiz * index;
+
+	if ((op->last_frames) && (lcf->flags & RX_THR)) {
+		bcm_rx_changed(op, lcf);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * bcm_rx_thr_flush - Check for throttled data and send it to the userspace
+ */
+static int bcm_rx_thr_flush(struct bcm_op *op)
+{
+	int updated = 0;
+
+	if (op->nframes > 1) {
+		unsigned int i;
+
+		/* for MUX filter we start at index 1 */
+		for (i = 1; i < op->nframes; i++)
+			updated += bcm_rx_do_flush(op, i);
+
+	} else {
+		/* for RX_FILTER_ID and simple filter */
+		updated += bcm_rx_do_flush(op, 0);
+	}
+
+	return updated;
+}
+
+/*
+ * bcm_rx_thr_handler - the time for blocked content updates is over now:
+ *                      Check for throttled data and send it to the userspace
+ */
+static enum hrtimer_restart bcm_rx_thr_handler(struct hrtimer *hrtimer)
+{
+	struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer);
+	enum hrtimer_restart ret;
+
+	spin_lock_bh(&op->bcm_rx_update_lock);
+
+	/* kt_ival2 may have been concurrently cleared by bcm_rx_setup()
+	 * before it cancels this timer - never forward with a zero
+	 * interval in that case.
+	 */
+	if (bcm_rx_thr_flush(op) && op->kt_ival2) {
+		hrtimer_forward_now(hrtimer, op->kt_ival2);
+		ret = HRTIMER_RESTART;
+	} else {
+		/* rearm throttle handling */
+		op->kt_lastmsg = 0;
+		ret = HRTIMER_NORESTART;
+	}
+
+	spin_unlock_bh(&op->bcm_rx_update_lock);
+
+	return ret;
+}
+
+/*
+ * bcm_rx_handler - handle a CAN frame reception
+ */
+static void bcm_rx_handler(struct sk_buff *skb, void *data)
+{
+	struct bcm_op *op = (struct bcm_op *)data;
+	const struct canfd_frame *rxframe = (struct canfd_frame *)skb->data;
+	struct canfd_frame rtrframe;
+	unsigned int i;
+	unsigned char traffic_flags;
+	bool rtr_frame;
+
+	if (op->can_id != rxframe->can_id)
+		return;
+
+	/* make sure to handle the correct frame type (CAN / CAN FD) */
+	if (op->flags & CAN_FD_FRAME) {
+		if (!can_is_canfd_skb(skb))
+			return;
+	} else {
+		if (!can_is_can_skb(skb))
+			return;
+	}
+
+	/* An ANYDEV op with an active RX timeout and/or throttle timer
+	 * tracks a single source interface: claim the first interface that
+	 * delivers a matching frame and reject frames from any other one,
+	 * before hrtimer_cancel() below can touch op->timer - this avoids
+	 * racing bcm_rx_timeout_handler() across concurrent interfaces.
+	 * RX_RTR_FRAME ops are excluded, as kt_ival1/kt_ival2 may briefly
+	 * hold a stale value from an earlier non-RTR configuration.
+	 */
+	if (!op->ifindex) {
+		spin_lock_bh(&op->bcm_rx_update_lock);
+
+		if (!(op->flags & RX_RTR_FRAME) &&
+		    (op->kt_ival1 || op->kt_ival2)) {
+			/* don't claim to vanishing interface */
+			if (!op->if_detected &&
+			    READ_ONCE(skb->dev->reg_state) == NETREG_REGISTERED)
+				op->if_detected = skb->dev->ifindex;
+
+			if (op->if_detected != skb->dev->ifindex) {
+				spin_unlock_bh(&op->bcm_rx_update_lock);
+				return;
+			}
+		}
+
+		spin_unlock_bh(&op->bcm_rx_update_lock);
+	}
+
+	/* disable timeout */
+	hrtimer_cancel(&op->timer);
+
+	/* op->flags/op->frames may be updated concurrently by bcm_rx_setup() */
+	spin_lock_bh(&op->bcm_rx_update_lock);
+
+	rtr_frame = op->flags & RX_RTR_FRAME;
+	if (rtr_frame) {
+		bcm_update_rx_stats(op);
+		/* snapshot RTR content under lock */
+		memcpy(&rtrframe, op->frames, op->cfsiz);
+		spin_unlock_bh(&op->bcm_rx_update_lock);
+
+		/* send reply for RTR-request (placed in op->frames[0]) */
+		bcm_can_tx(op, &rtrframe);
+		return;
+	}
+
+	/* update statistics in the same critical section as bcm_rx_changed()
+	 * below: frames_filtered must never be checked/incremented against a
+	 * frames_abs snapshot from a concurrent bcm_rx_handler() call on
+	 * another CPU for the same (wildcard) op, or frames_filtered can end
+	 * up larger than frames_abs.
+	 */
+	bcm_update_rx_stats(op);
+
+	/* compute flags to distinguish between own/local/remote CAN traffic */
+	traffic_flags = 0;
+	if (skb->sk) {
+		traffic_flags |= RX_LOCAL;
+		if (skb->sk == op->sk)
+			traffic_flags |= RX_OWN;
+	}
+
+	/* save rx timestamp and originator for recvfrom() under lock: an
+	 * ANYDEV op without an active timer can still run concurrently on
+	 * different CPUs, so content and meta data must be bundled here.
+	 */
+	op->rx_stamp = skb->tstamp;
+	op->rx_ifindex = skb->dev->ifindex;
+
+	if (op->flags & RX_FILTER_ID) {
+		/* the easiest case */
+		bcm_rx_update_and_send(op, op->last_frames, rxframe,
+				       traffic_flags);
+		goto rx_starttimer;
+	}
+
+	if (op->nframes == 1) {
+		/* simple compare with index 0 */
+		bcm_rx_cmp_to_index(op, 0, rxframe, traffic_flags);
+		goto rx_starttimer;
+	}
+
+	if (op->nframes > 1) {
+		/*
+		 * multiplex compare
+		 *
+		 * find the first multiplex mask that fits.
+		 * Remark: The MUX-mask is stored in index 0 - but only the
+		 * first 64 bits of the frame data[] are relevant (CAN FD)
+		 */
+
+		for (i = 1; i < op->nframes; i++) {
+			if ((get_u64(op->frames, 0) & get_u64(rxframe, 0)) ==
+			    (get_u64(op->frames, 0) &
+			     get_u64(op->frames + op->cfsiz * i, 0))) {
+				bcm_rx_cmp_to_index(op, i, rxframe,
+						    traffic_flags);
+				break;
+			}
+		}
+	}
+
+rx_starttimer:
+	bcm_rx_starttimer(op);
+
+	spin_unlock_bh(&op->bcm_rx_update_lock);
+}
+
+/*
+ * helpers for bcm_op handling: find & delete bcm [rx|tx] op elements
+ */
+static struct bcm_op *bcm_find_op(struct list_head *ops,
+				  struct bcm_msg_head *mh, int ifindex)
+{
+	struct bcm_op *op;
+
+	list_for_each_entry(op, ops, list) {
+		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME))
+			return op;
+	}
+
+	return NULL;
+}
+
+static void bcm_free_op_work(struct work_struct *work)
+{
+	struct bcm_op *op = container_of(work, struct bcm_op, work);
+
+	hrtimer_cancel(&op->timer);
+	hrtimer_cancel(&op->thrtimer);
+
+	if ((op->frames) && (op->frames != &op->sframe))
+		kfree(op->frames);
+
+	if ((op->last_frames) && (op->last_frames != &op->last_sframe))
+		kfree(op->last_frames);
+
+	/* the last possible access to op->timer/op->thrtimer has now
+	 * happened above via hrtimer_cancel() - op->sk is no longer
+	 * needed by any pending timer callback, so drop our reference
+	 */
+	sock_put(op->sk);
+
+	kfree(op);
+}
+
+static void bcm_free_op_rcu(struct rcu_head *rcu_head)
+{
+	struct bcm_op *op = container_of(rcu_head, struct bcm_op, rcu);
+
+	INIT_WORK(&op->work, bcm_free_op_work);
+	queue_work(bcm_wq, &op->work);
+}
+
+static void bcm_remove_op(struct bcm_op *op)
+{
+	hrtimer_cancel(&op->timer);
+	hrtimer_cancel(&op->thrtimer);
+
+	call_rcu(&op->rcu, bcm_free_op_rcu);
+}
+
+static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
+{
+	if (op->rx_reg_dev == dev) {
+		can_rx_unregister(dev_net(dev), dev, op->can_id,
+				  REGMASK(op->can_id), bcm_rx_handler, op);
+
+		/* mark as removed subscription */
+		op->rx_reg_dev = NULL;
+		netdev_put(dev, &op->rx_reg_dev_tracker);
+	} else
+		printk(KERN_ERR "can-bcm: bcm_rx_unreg: registered device "
+		       "mismatch %p %p\n", op->rx_reg_dev, dev);
+}
+
+/*
+ * bcm_delete_rx_op - find and remove a rx op (returns number of removed ops)
+ */
+static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
+			    int ifindex)
+{
+	struct bcm_op *op, *n;
+
+	list_for_each_entry_safe(op, n, ops, list) {
+		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
+
+			/* disable automatic timer on frame reception */
+			op->flags |= RX_NO_AUTOTIMER;
+
+			/*
+			 * Don't care if we're bound or not (due to netdev
+			 * problems) can_rx_unregister() is always a save
+			 * thing to do here.
+			 */
+			if (op->ifindex) {
+				/*
+				 * Only remove subscriptions that had not
+				 * been removed due to NETDEV_UNREGISTER
+				 * in bcm_notifier()
+				 *
+				 * op->rx_reg_dev is a tracked reference taken
+				 * when the subscription was registered, so it
+				 * stays valid here even if a concurrent
+				 * NETDEV_UNREGISTER already unlisted the dev.
+				 */
+				if (op->rx_reg_dev)
+					bcm_rx_unreg(op->rx_reg_dev, op);
+			} else
+				can_rx_unregister(sock_net(op->sk), NULL,
+						  op->can_id,
+						  REGMASK(op->can_id),
+						  bcm_rx_handler, op);
+
+			list_del_rcu(&op->list);
+			bcm_remove_op(op);
+			return 1; /* done */
+		}
+	}
+
+	return 0; /* not found */
+}
+
+/*
+ * bcm_delete_tx_op - find and remove a tx op (returns number of removed ops)
+ */
+static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
+			    int ifindex)
+{
+	struct bcm_op *op, *n;
+
+	list_for_each_entry_safe(op, n, ops, list) {
+		if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
+		    (op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
+			list_del_rcu(&op->list);
+			bcm_remove_op(op);
+			return 1; /* done */
+		}
+	}
+
+	return 0; /* not found */
+}
+
+/*
+ * bcm_read_op - read out a bcm_op and send it to the user (for bcm_sendmsg)
+ */
+static int bcm_read_op(struct list_head *ops, struct bcm_msg_head *msg_head,
+		       int ifindex)
+{
+	struct bcm_op *op = bcm_find_op(ops, msg_head, ifindex);
+
+	if (!op)
+		return -EINVAL;
+
+	/* put current values into msg_head */
+	msg_head->flags   = op->flags;
+	msg_head->count   = op->count;
+	msg_head->ival1   = op->ival1;
+	msg_head->ival2   = op->ival2;
+	msg_head->nframes = op->nframes;
+
+	bcm_send_to_user(op, msg_head, op->frames, 0);
+
+	return MHSIZ;
+}
+
+/*
+ * bcm_tx_setup - create or update a bcm tx op (for bcm_sendmsg)
+ */
+static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
+			int ifindex, struct sock *sk)
+{
+	struct bcm_sock *bo = bcm_sk(sk);
+	struct bcm_op *op;
+	struct canfd_frame *cf;
+	bool add_op_to_list = false;
+	unsigned int i;
+	int err;
+
+	/* we need a real device to send frames */
+	if (!ifindex)
+		return -ENODEV;
+
+	/* check nframes boundaries - we need at least one CAN frame */
+	if (msg_head->nframes < 1 || msg_head->nframes > MAX_NFRAMES)
+		return -EINVAL;
+
+	/* check timeval limitations */
+	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+		return -EINVAL;
+
+	/* check the given can_id */
+	op = bcm_find_op(&bo->tx_ops, msg_head, ifindex);
+	if (op) {
+		void *new_frames;
+
+		/* update existing BCM operation */
+
+		/*
+		 * Do we need more space for the CAN frames than currently
+		 * allocated? -> This is a _really_ unusual use-case and
+		 * therefore (complexity / locking) it is not supported.
+		 */
+		if (msg_head->nframes > op->nframes)
+			return -E2BIG;
+
+		/* get new CAN frames content into a staging buffer before
+		 * locking: validate and normalize the frames there so that
+		 * bcm_can_tx() / bcm_tx_timeout_handler() never observe a
+		 * partially updated or unvalidated frame in op->frames
+		 */
+		new_frames = kmalloc(msg_head->nframes * op->cfsiz, GFP_KERNEL);
+		if (!new_frames)
+			return -ENOMEM;
+
+		for (i = 0; i < msg_head->nframes; i++) {
+
+			cf = new_frames + op->cfsiz * i;
+			err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
+			if (err < 0) {
+				kfree(new_frames);
+				return err;
+			}
+
+			if (op->flags & CAN_FD_FRAME) {
+				if (cf->len > 64)
+					err = -EINVAL;
+			} else {
+				if (cf->len > 8)
+					err = -EINVAL;
+			}
+
+			if (err < 0) {
+				kfree(new_frames);
+				return err;
+			}
+
+			if (msg_head->flags & TX_CP_CAN_ID) {
+				/* copy can_id into frame */
+				cf->can_id = msg_head->can_id;
+			}
+		}
+
+		spin_lock_bh(&op->bcm_tx_lock);
+
+		/* update CAN frames content */
+		memcpy(op->frames, new_frames, msg_head->nframes * op->cfsiz);
+
+		op->flags = msg_head->flags;
+
+		if (op->nframes != msg_head->nframes ||
+		    op->flags & TX_RESET_MULTI_IDX) {
+			/* potentially update changed nframes */
+			op->nframes = msg_head->nframes;
+			/* restart multiple frame transmission */
+			op->currframe = 0;
+		}
+
+		if (op->flags & SETTIMER)
+			op->count = msg_head->count;
+
+		spin_unlock_bh(&op->bcm_tx_lock);
+
+		kfree(new_frames);
+
+	} else {
+		/* insert new BCM operation for the given can_id */
+
+		op = kzalloc(OPSIZ, GFP_KERNEL);
+		if (!op)
+			return -ENOMEM;
+
+		spin_lock_init(&op->bcm_tx_lock);
+		op->can_id = msg_head->can_id;
+		op->cfsiz = CFSIZ(msg_head->flags);
+		op->flags = msg_head->flags;
+		op->nframes = msg_head->nframes;
+
+		if (op->flags & SETTIMER)
+			op->count = msg_head->count;
+
+		/* create array for CAN frames and copy the data */
+		if (msg_head->nframes > 1) {
+			op->frames = kmalloc_array(msg_head->nframes,
+						   op->cfsiz,
+						   GFP_KERNEL);
+			if (!op->frames) {
+				kfree(op);
+				return -ENOMEM;
+			}
+		} else
+			op->frames = &op->sframe;
+
+		for (i = 0; i < msg_head->nframes; i++) {
+
+			cf = op->frames + op->cfsiz * i;
+			err = memcpy_from_msg((u8 *)cf, msg, op->cfsiz);
+			if (err < 0)
+				goto free_op;
+
+			if (op->flags & CAN_FD_FRAME) {
+				if (cf->len > 64)
+					err = -EINVAL;
+			} else {
+				if (cf->len > 8)
+					err = -EINVAL;
+			}
+
+			if (err < 0)
+				goto free_op;
+
+			if (msg_head->flags & TX_CP_CAN_ID) {
+				/* copy can_id into frame */
+				cf->can_id = msg_head->can_id;
+			}
+		}
+
+		/* tx_ops never compare with previous received messages */
+		op->last_frames = NULL;
+
+		/* bcm_can_tx / bcm_tx_timeout_handler needs this */
+		op->sk = sk;
+		sock_hold(sk);
+		op->ifindex = ifindex;
+
+		/* initialize uninitialized (kzalloc) structure */
+		hrtimer_setup(&op->timer, bcm_tx_timeout_handler, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL_SOFT);
+
+		/* currently unused in tx_ops */
+		hrtimer_setup(&op->thrtimer, hrtimer_dummy_timeout, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL_SOFT);
+
+		add_op_to_list = true;
+
+	} /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
+
+	if (op->flags & SETTIMER) {
+		/* set timer values */
+		spin_lock_bh(&op->bcm_tx_lock);
+		op->ival1 = msg_head->ival1;
+		op->ival2 = msg_head->ival2;
+		op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
+		op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
+		spin_unlock_bh(&op->bcm_tx_lock);
+
+		/* disable an active timer due to zero values? */
+		if (!op->kt_ival1 && !op->kt_ival2)
+			hrtimer_cancel(&op->timer);
+	}
+
+	if (op->flags & STARTTIMER) {
+		hrtimer_cancel(&op->timer);
+		/* spec: send CAN frame when starting timer */
+		op->flags |= TX_ANNOUNCE;
+	}
+
+	/* add this bcm_op to the list of the tx_ops? */
+	if (add_op_to_list)
+		list_add_rcu(&op->list, &bo->tx_ops);
+
+	if (op->flags & TX_ANNOUNCE)
+		bcm_can_tx(op, NULL);
+
+	if (op->flags & STARTTIMER)
+		bcm_tx_start_timer(op);
+
+	return msg_head->nframes * op->cfsiz + MHSIZ;
+
+free_op:
+	if (op->frames != &op->sframe)
+		kfree(op->frames);
+	kfree(op);
+	return err;
+}
+
+static int bcm_rx_setup_rtr_check(struct bcm_msg_head *msg_head,
+				  struct bcm_op *op, void *new_frames)
+{
+	struct canfd_frame *frame0 = new_frames;
+
+	if (!(msg_head->flags & RX_RTR_FRAME))
+		return 0;
+
+	/* this frame is sent out as-is by bcm_can_tx() whenever a matching
+	 * remote request is received, so validate its length the same way
+	 * bcm_tx_setup() validates TX_SETUP frames before installing it
+	 */
+	if (msg_head->flags & CAN_FD_FRAME) {
+		if (frame0->len > 64)
+			return -EINVAL;
+	} else {
+		if (frame0->len > 8)
+			return -EINVAL;
+	}
+
+	/* funny feature in RX(!)_SETUP only for RTR-mode:
+	 * copy can_id into frame BUT without RTR-flag to
+	 * prevent a full-load-loopback-test ... ;-]
+	 * normalize this on the staged buffer, before it is
+	 * ever installed into op->frames.
+	 */
+	if ((msg_head->flags & TX_CP_CAN_ID) ||
+	    frame0->can_id == op->can_id)
+		frame0->can_id = op->can_id & ~CAN_RTR_FLAG;
+
+	return 0;
+}
+
+/*
+ * bcm_rx_setup - create or update a bcm rx op (for bcm_sendmsg)
+ */
+static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
+			int ifindex, struct sock *sk)
+{
+	struct bcm_sock *bo = bcm_sk(sk);
+	struct bcm_op *op;
+	int do_rx_register;
+	int new_op = 0;
+	int err = 0;
+
+	if ((msg_head->flags & RX_FILTER_ID) || (!(msg_head->nframes))) {
+		/* be robust against wrong usage ... */
+		msg_head->flags |= RX_FILTER_ID;
+		/* ignore trailing garbage */
+		msg_head->nframes = 0;
+	}
+
+	/* the first element contains the mux-mask => MAX_NFRAMES + 1  */
+	if (msg_head->nframes > MAX_NFRAMES + 1)
+		return -EINVAL;
+
+	if ((msg_head->flags & RX_RTR_FRAME) &&
+	    ((msg_head->nframes != 1) ||
+	     (!(msg_head->can_id & CAN_RTR_FLAG))))
+		return -EINVAL;
+
+	/* check timeval limitations */
+	if ((msg_head->flags & SETTIMER) && bcm_is_invalid_tv(msg_head))
+		return -EINVAL;
+
+	/* check the given can_id */
+	op = bcm_find_op(&bo->rx_ops, msg_head, ifindex);
+	if (op) {
+		void *new_frames = NULL;
+
+		/* update existing BCM operation */
+
+		/*
+		 * Do we need more space for the CAN frames than currently
+		 * allocated? -> This is a _really_ unusual use-case and
+		 * therefore (complexity / locking) it is not supported.
+		 */
+		if (msg_head->nframes > op->nframes)
+			return -E2BIG;
+
+		if (msg_head->nframes) {
+			/* get new CAN frames content before locking */
+			new_frames = kmalloc(msg_head->nframes * op->cfsiz,
+					     GFP_KERNEL);
+			if (!new_frames)
+				return -ENOMEM;
+
+			err = memcpy_from_msg(new_frames, msg,
+					      msg_head->nframes * op->cfsiz);
+			if (err < 0) {
+				kfree(new_frames);
+				return err;
+			}
+
+			err = bcm_rx_setup_rtr_check(msg_head, op, new_frames);
+			if (err < 0) {
+				kfree(new_frames);
+				return err;
+			}
+		}
+
+		spin_lock_bh(&op->bcm_rx_update_lock);
+		op->nframes = msg_head->nframes;
+		op->flags = msg_head->flags;
+
+		if (msg_head->nframes) {
+			/* update CAN frames content */
+			memcpy(op->frames, new_frames,
+			       msg_head->nframes * op->cfsiz);
+
+			/* clear last_frames to indicate 'nothing received' */
+			memset(op->last_frames, 0,
+			       msg_head->nframes * op->cfsiz);
+		}
+
+		if (msg_head->flags & SETTIMER) {
+			op->ival1 = msg_head->ival1;
+			op->ival2 = msg_head->ival2;
+			op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
+			op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
+			op->kt_lastmsg = 0;
+			op->if_detected = 0; /* reclaim ifindex in ANYDEV mode */
+		}
+		spin_unlock_bh(&op->bcm_rx_update_lock);
+
+		/* free temporary frames / kfree(NULL) is safe */
+		kfree(new_frames);
+
+		/* Don't register a new CAN filter for the rx_op update unless
+		 * a concurrent NETDEV_UNREGISTER notifier already tore down
+		 * the previous registration. In this case the receiver needs
+		 * to be re-registered here so that this update doesn't
+		 * silently stop delivering frames for the given ifindex.
+		 * Ops with ifindex = 0 (all CAN interfaces) never carry a
+		 * tracked rx_reg_dev and stay registered as-is.
+		 */
+		do_rx_register = (ifindex && !op->rx_reg_dev) ? 1 : 0;
+
+	} else {
+		/* insert new BCM operation for the given can_id */
+		op = kzalloc(OPSIZ, GFP_KERNEL);
+		if (!op)
+			return -ENOMEM;
+
+		spin_lock_init(&op->bcm_tx_lock);
+		spin_lock_init(&op->bcm_rx_update_lock);
+		op->can_id = msg_head->can_id;
+		op->nframes = msg_head->nframes;
+		op->cfsiz = CFSIZ(msg_head->flags);
+		op->flags = msg_head->flags;
+
+		if (msg_head->nframes > 1) {
+			/* create array for CAN frames and copy the data */
+			op->frames = kmalloc_array(msg_head->nframes,
+						   op->cfsiz,
+						   GFP_KERNEL);
+			if (!op->frames) {
+				kfree(op);
+				return -ENOMEM;
+			}
+
+			/* create and init array for received CAN frames */
+			op->last_frames = kcalloc(msg_head->nframes,
+						  op->cfsiz,
+						  GFP_KERNEL);
+			if (!op->last_frames) {
+				kfree(op->frames);
+				kfree(op);
+				return -ENOMEM;
+			}
+
+		} else {
+			op->frames = &op->sframe;
+			op->last_frames = &op->last_sframe;
+		}
+
+		if (msg_head->nframes) {
+			err = memcpy_from_msg(op->frames, msg,
+					      msg_head->nframes * op->cfsiz);
+			if (err < 0)
+				goto free_op;
+
+			err = bcm_rx_setup_rtr_check(msg_head, op, op->frames);
+			if (err < 0)
+				goto free_op;
+		}
+
+		/* bcm_can_tx / bcm_tx_timeout_handler needs this */
+		op->sk = sk;
+		sock_hold(sk);
+		op->ifindex = ifindex;
+
+		/* ifindex for timeout events w/o previous frame reception */
+		op->rx_ifindex = ifindex;
+
+		/* initialize uninitialized (kzalloc) structure */
+		hrtimer_setup(&op->timer, bcm_rx_timeout_handler, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL_SOFT);
+		hrtimer_setup(&op->thrtimer, bcm_rx_thr_handler, CLOCK_MONOTONIC,
+			      HRTIMER_MODE_REL_SOFT);
+
+		/* call can_rx_register() */
+		do_rx_register = 1;
+		new_op = 1;
+
+	} /* if ((op = bcm_find_op(&bo->rx_ops, msg_head->can_id, ifindex))) */
+
+	/* check flags */
+
+	if (op->flags & RX_RTR_FRAME) {
+		/* no timers in RTR-mode */
+		hrtimer_cancel(&op->thrtimer);
+		hrtimer_cancel(&op->timer);
+	} else {
+		if (op->flags & SETTIMER) {
+
+			/* set timers (locked) for newly created op */
+			if (new_op) {
+				spin_lock_bh(&op->bcm_rx_update_lock);
+				op->ival1 = msg_head->ival1;
+				op->ival2 = msg_head->ival2;
+				op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
+				op->kt_ival2 = bcm_timeval_to_ktime(msg_head->ival2);
+				op->kt_lastmsg = 0;
+				spin_unlock_bh(&op->bcm_rx_update_lock);
+			}
+
+			/* disable an active timer due to zero value? */
+			if (!op->kt_ival1)
+				hrtimer_cancel(&op->timer);
+
+			/*
+			 * In any case cancel the throttle timer, flush
+			 * potentially blocked msgs and reset throttle handling
+			 */
+			hrtimer_cancel(&op->thrtimer);
+
+			spin_lock_bh(&op->bcm_rx_update_lock);
+			bcm_rx_thr_flush(op);
+			spin_unlock_bh(&op->bcm_rx_update_lock);
+		}
+
+		if ((op->flags & STARTTIMER) && op->kt_ival1)
+			hrtimer_start(&op->timer, op->kt_ival1,
+				      HRTIMER_MODE_REL_SOFT);
+	}
+
+	/* now we can register for can_ids, if we added a new bcm_op
+	 * or need to re-register after a NETDEV_UNREGISTER tore down
+	 * the previous registration of an existing op
+	 */
+	if (do_rx_register) {
+		if (ifindex) {
+			struct net_device *dev;
+
+			dev = dev_get_by_index(sock_net(sk), ifindex);
+			if (dev) {
+				err = can_rx_register(sock_net(sk), dev,
+						      op->can_id,
+						      REGMASK(op->can_id),
+						      bcm_rx_handler, op,
+						      "bcm", sk);
+
+				/* keep a tracked reference so that a later
+				 * unregister can safely reach the device even
+				 * if a concurrent NETDEV_UNREGISTER has
+				 * already unlisted it by ifindex
+				 */
+				if (!err) {
+					op->rx_reg_dev = dev;
+					netdev_hold(dev,
+						    &op->rx_reg_dev_tracker,
+						    GFP_KERNEL);
+				}
+				dev_put(dev);
+			} else {
+				/* the requested device is gone - do not
+				 * silently succeed without registering
+				 */
+				err = -ENODEV;
+			}
+
+		} else {
+			err = can_rx_register(sock_net(sk), NULL, op->can_id,
+					      REGMASK(op->can_id),
+					      bcm_rx_handler, op, "bcm", sk);
+		}
+
+		if (err) {
+			/* newly created bcm rx op is broken -> remove it */
+			if (new_op) {
+				bcm_remove_op(op);
+				return err;
+			}
+
+			/* an existing op just stays unregistered.
+			 * Cancel op->timer and (defensively) op->thrtimer.
+			 * Other settings can't be reached until the next
+			 * successful RX_SETUP.
+			 */
+			hrtimer_cancel(&op->timer);
+			hrtimer_cancel(&op->thrtimer);
+			return err;
+		}
+
+		/* add a new bcm_op to the list of the rx_ops */
+		if (new_op)
+			list_add_rcu(&op->list, &bo->rx_ops);
+	}
+
+	return msg_head->nframes * op->cfsiz + MHSIZ;
+
+free_op:
+	if (op->frames != &op->sframe)
+		kfree(op->frames);
+	if (op->last_frames != &op->last_sframe)
+		kfree(op->last_frames);
+	kfree(op);
+	return err;
+}
+
+/*
+ * bcm_tx_send - send a single CAN frame to the CAN interface (for bcm_sendmsg)
+ */
+static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
+		       int cfsiz)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct net_device *dev;
+	int err;
+
+	/* we need a real device to send frames */
+	if (!ifindex)
+		return -ENODEV;
+
+	skb = alloc_skb(cfsiz, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	err = memcpy_from_msg(skb_put(skb, cfsiz), msg, cfsiz);
+	if (err < 0) {
+		kfree_skb(skb);
+		return err;
+	}
+
+	dev = dev_get_by_index(sock_net(sk), ifindex);
+	if (!dev) {
+		kfree_skb(skb);
+		return -ENODEV;
+	}
+
+	csx->can_iif = dev->ifindex;
+	skb->dev = dev;
+	can_skb_set_owner(skb, sk);
+	err = can_send(skb, 1); /* send with loopback */
+	dev_put(dev);
+
+	if (err)
+		return err;
+
+	return cfsiz + MHSIZ;
+}
+
+/*
+ * bcm_sendmsg - process BCM commands (opcodes) from the userspace
+ */
+static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct bcm_sock *bo = bcm_sk(sk);
+	int ifindex;
+	struct bcm_msg_head msg_head;
+	int cfsiz;
+	int ret; /* read bytes or error codes as return value */
+
+	/* Lockless fast-path check for bound socket */
+	if (!READ_ONCE(bo->bound))
+		return -ENOTCONN;
+
+	/* check for valid message length from userspace */
+	if (size < MHSIZ)
+		return -EINVAL;
+
+	/* read message head information */
+	ret = memcpy_from_msg((u8 *)&msg_head, msg, MHSIZ);
+	if (ret < 0)
+		return ret;
+
+	cfsiz = CFSIZ(msg_head.flags);
+	if ((size - MHSIZ) % cfsiz)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	/* Re-validate under the socket lock: a concurrent bcm_notify()
+	 * may have unbound this socket (device removal) after the
+	 * lockless fast-path check above. bo->ifindex is only ever
+	 * mutated under lock_sock(), so reading it here - instead of
+	 * before taking the lock - guarantees it can't be observed
+	 * torn against bo->bound.
+	 */
+	if (!bo->bound) {
+		ret = -ENOTCONN;
+		goto out_release;
+	}
+
+	/* default ifindex for this bcm_op */
+	ifindex = bo->ifindex;
+
+	/* check for alternative ifindex for this bcm_op */
+
+	if (!ifindex && msg->msg_name) {
+		/* no bound device as default => check msg_name */
+		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
+
+		if (msg->msg_namelen < BCM_MIN_NAMELEN) {
+			ret = -EINVAL;
+			goto out_release;
+		}
+
+		if (addr->can_family != AF_CAN) {
+			ret = -EINVAL;
+			goto out_release;
+		}
+
+		/* ifindex from sendto() */
+		ifindex = addr->can_ifindex;
+
+		if (ifindex) {
+			struct net_device *dev;
+
+			dev = dev_get_by_index(sock_net(sk), ifindex);
+			if (!dev) {
+				ret = -ENODEV;
+				goto out_release;
+			}
+
+			if (dev->type != ARPHRD_CAN) {
+				dev_put(dev);
+				ret = -ENODEV;
+				goto out_release;
+			}
+
+			dev_put(dev);
+		}
+	}
+
+	switch (msg_head.opcode) {
+
+	case TX_SETUP:
+		ret = bcm_tx_setup(&msg_head, msg, ifindex, sk);
+		break;
+
+	case RX_SETUP:
+		ret = bcm_rx_setup(&msg_head, msg, ifindex, sk);
+		break;
+
+	case TX_DELETE:
+		if (bcm_delete_tx_op(&bo->tx_ops, &msg_head, ifindex))
+			ret = MHSIZ;
+		else
+			ret = -EINVAL;
+		break;
+
+	case RX_DELETE:
+		if (bcm_delete_rx_op(&bo->rx_ops, &msg_head, ifindex))
+			ret = MHSIZ;
+		else
+			ret = -EINVAL;
+		break;
+
+	case TX_READ:
+		/* reuse msg_head for the reply to TX_READ */
+		msg_head.opcode  = TX_STATUS;
+		ret = bcm_read_op(&bo->tx_ops, &msg_head, ifindex);
+		break;
+
+	case RX_READ:
+		/* reuse msg_head for the reply to RX_READ */
+		msg_head.opcode  = RX_STATUS;
+		ret = bcm_read_op(&bo->rx_ops, &msg_head, ifindex);
+		break;
+
+	case TX_SEND:
+		/* we need exactly one CAN frame behind the msg head */
+		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
+			ret = -EINVAL;
+		else
+			ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+out_release:
+	release_sock(sk);
+
+	return ret;
+}
+
+/*
+ * notification handler for netdevice status changes
+ */
+static void bcm_notify(struct bcm_sock *bo, unsigned long msg,
+		       struct net_device *dev)
+{
+	struct sock *sk = &bo->sk;
+	struct bcm_op *op;
+	int notify_enodev = 0;
+
+	if (!net_eq(dev_net(dev), sock_net(sk)))
+		return;
+
+	switch (msg) {
+
+	case NETDEV_UNREGISTER:
+		lock_sock(sk);
+
+		/* rx_ops: remove device specific receive entries */
+		list_for_each_entry(op, &bo->rx_ops, list) {
+			if (op->rx_reg_dev == dev)
+				bcm_rx_unreg(dev, op);
+
+			/* release an ANYDEV op's claim (see bcm_rx_handler())
+			 * on this now confirmed-gone interface.
+			 */
+			if (!op->ifindex) {
+				spin_lock_bh(&op->bcm_rx_update_lock);
+				if (op->if_detected == dev->ifindex)
+					op->if_detected = 0;
+				spin_unlock_bh(&op->bcm_rx_update_lock);
+			}
+		}
+
+		/* tx_ops: stop device specific cyclic transmissions on the
+		 * vanishing ifindex. Cancelling the timer is enough to stop
+		 * cyclic bcm_can_tx() calls as there is no re-arming.
+		 */
+		list_for_each_entry(op, &bo->tx_ops, list)
+			if (op->ifindex == dev->ifindex)
+				hrtimer_cancel(&op->timer);
+
+		/* remove device reference, if this is our bound device */
+		if (bo->bound && bo->ifindex == dev->ifindex) {
+#if IS_ENABLED(CONFIG_PROC_FS)
+			if (sock_net(sk)->can.bcmproc_dir && bo->bcm_proc_read) {
+				remove_proc_entry(bo->procname, sock_net(sk)->can.bcmproc_dir);
+				bo->bcm_proc_read = NULL;
+			}
+#endif
+			/* Paired with the lockless fast-path check in
+			 * bcm_sendmsg(); bo->ifindex itself is only ever
+			 * accessed under lock_sock() so it needs no
+			 * annotation.
+			 */
+			WRITE_ONCE(bo->bound, 0);
+			bo->ifindex = 0;
+			notify_enodev = 1;
+		}
+
+		release_sock(sk);
+
+		if (notify_enodev) {
+			sk->sk_err = ENODEV;
+			if (!sock_flag(sk, SOCK_DEAD))
+				sk_error_report(sk);
+		}
+		break;
+
+	case NETDEV_DOWN:
+		if (bo->bound && bo->ifindex == dev->ifindex) {
+			sk->sk_err = ENETDOWN;
+			if (!sock_flag(sk, SOCK_DEAD))
+				sk_error_report(sk);
+		}
+	}
+}
+
+static int bcm_notifier(struct notifier_block *nb, unsigned long msg,
+			void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+	if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+		return NOTIFY_DONE;
+	if (unlikely(bcm_busy_notifier)) /* Check for reentrant bug. */
+		return NOTIFY_DONE;
+
+	spin_lock(&bcm_notifier_lock);
+	list_for_each_entry(bcm_busy_notifier, &bcm_notifier_list, notifier) {
+		spin_unlock(&bcm_notifier_lock);
+		bcm_notify(bcm_busy_notifier, msg, dev);
+		spin_lock(&bcm_notifier_lock);
+	}
+	bcm_busy_notifier = NULL;
+	spin_unlock(&bcm_notifier_lock);
+	return NOTIFY_DONE;
+}
+
+/*
+ * initial settings for all BCM sockets to be set at socket creation time
+ */
+static int bcm_init(struct sock *sk)
+{
+	struct bcm_sock *bo = bcm_sk(sk);
+
+	bo->bound            = 0;
+	bo->ifindex          = 0;
+	bo->dropped_usr_msgs = 0;
+	bo->bcm_proc_read    = NULL;
+
+	INIT_LIST_HEAD(&bo->tx_ops);
+	INIT_LIST_HEAD(&bo->rx_ops);
+
+	/* set notifier */
+	spin_lock(&bcm_notifier_lock);
+	list_add_tail(&bo->notifier, &bcm_notifier_list);
+	spin_unlock(&bcm_notifier_lock);
+
+	return 0;
+}
+
+/*
+ * standard socket functions
+ */
+static int bcm_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct net *net;
+	struct bcm_sock *bo;
+	struct bcm_op *op, *next;
+
+	if (!sk)
+		return 0;
+
+	net = sock_net(sk);
+	bo = bcm_sk(sk);
+
+	/* remove bcm_ops, timer, rx_unregister(), etc. */
+
+	spin_lock(&bcm_notifier_lock);
+	while (bcm_busy_notifier == bo) {
+		spin_unlock(&bcm_notifier_lock);
+		schedule_timeout_uninterruptible(1);
+		spin_lock(&bcm_notifier_lock);
+	}
+	list_del(&bo->notifier);
+	spin_unlock(&bcm_notifier_lock);
+
+	lock_sock(sk);
+
+#if IS_ENABLED(CONFIG_PROC_FS)
+	/* remove procfs entry */
+	if (net->can.bcmproc_dir && bo->bcm_proc_read)
+		remove_proc_entry(bo->procname, net->can.bcmproc_dir);
+#endif /* CONFIG_PROC_FS */
+
+	list_for_each_entry_safe(op, next, &bo->tx_ops, list) {
+		list_del_rcu(&op->list);
+		bcm_remove_op(op);
+	}
+
+	list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
+		/*
+		 * Don't care if we're bound or not (due to netdev problems)
+		 * can_rx_unregister() is always a save thing to do here.
+		 */
+		if (op->ifindex) {
+			/*
+			 * Only remove subscriptions that had not
+			 * been removed due to NETDEV_UNREGISTER
+			 * in bcm_notifier()
+			 *
+			 * op->rx_reg_dev is a tracked reference taken
+			 * when the subscription was registered, so it
+			 * stays valid here even if a concurrent
+			 * NETDEV_UNREGISTER already unlisted the device.
+			 */
+			if (op->rx_reg_dev)
+				bcm_rx_unreg(op->rx_reg_dev, op);
+		} else
+			can_rx_unregister(net, NULL, op->can_id,
+					  REGMASK(op->can_id),
+					  bcm_rx_handler, op);
+
+	}
+
+	synchronize_rcu();
+
+	list_for_each_entry_safe(op, next, &bo->rx_ops, list) {
+		list_del_rcu(&op->list);
+		bcm_remove_op(op);
+	}
+
+	/* remove device reference */
+	if (bo->bound) {
+		WRITE_ONCE(bo->bound, 0);
+		bo->ifindex = 0;
+	}
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	sock_prot_inuse_add(net, sk->sk_prot, -1);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int bcm_connect(struct socket *sock, struct sockaddr_unsized *uaddr, int len,
+		       int flags)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct bcm_sock *bo = bcm_sk(sk);
+	struct net *net = sock_net(sk);
+	int ret = 0;
+
+	if (len < BCM_MIN_NAMELEN)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	if (bo->bound) {
+		ret = -EISCONN;
+		goto fail;
+	}
+
+	/* bind a device to this socket */
+	if (addr->can_ifindex) {
+		struct net_device *dev;
+
+		dev = dev_get_by_index(net, addr->can_ifindex);
+		if (!dev) {
+			ret = -ENODEV;
+			goto fail;
+		}
+		if (dev->type != ARPHRD_CAN) {
+			dev_put(dev);
+			ret = -ENODEV;
+			goto fail;
+		}
+
+		bo->ifindex = dev->ifindex;
+		dev_put(dev);
+
+	} else {
+		/* no interface reference for ifindex = 0 ('any' CAN device) */
+		bo->ifindex = 0;
+	}
+
+#if IS_ENABLED(CONFIG_PROC_FS)
+	if (net->can.bcmproc_dir) {
+		/* unique socket address as filename */
+		sprintf(bo->procname, "%llu", sock_i_ino(sk));
+		bo->bcm_proc_read = proc_create_net_single(bo->procname, 0644,
+						     net->can.bcmproc_dir,
+						     bcm_proc_show, sk);
+		if (!bo->bcm_proc_read) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+	}
+#endif /* CONFIG_PROC_FS */
+
+	/* bo->ifindex above is fully assigned before this point; pairs
+	 * with the lockless fast-path check in bcm_sendmsg()
+	 */
+	WRITE_ONCE(bo->bound, 1);
+
+fail:
+	release_sock(sk);
+
+	return ret;
+}
+
+static int bcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		       int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	int error = 0;
+	int err;
+
+	skb = skb_recv_datagram(sk, flags, &error);
+	if (!skb)
+		return error;
+
+	if (skb->len < size)
+		size = skb->len;
+
+	err = memcpy_to_msg(msg, skb->data, size);
+	if (err < 0) {
+		skb_free_datagram(sk, skb);
+		return err;
+	}
+
+	sock_recv_cmsgs(msg, sk, skb);
+
+	if (msg->msg_name) {
+		__sockaddr_check_size(BCM_MIN_NAMELEN);
+		msg->msg_namelen = BCM_MIN_NAMELEN;
+		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+	}
+
+	/* assign the flags that have been recorded in bcm_send_to_user() */
+	msg->msg_flags |= *(bcm_flags(skb));
+
+	skb_free_datagram(sk, skb);
+
+	return size;
+}
+
+static int bcm_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+				unsigned long arg)
+{
+	/* no ioctls for socket layer -> hand it down to NIC layer */
+	return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops bcm_ops = {
+	.family        = PF_CAN,
+	.release       = bcm_release,
+	.bind          = sock_no_bind,
+	.connect       = bcm_connect,
+	.socketpair    = sock_no_socketpair,
+	.accept        = sock_no_accept,
+	.getname       = sock_no_getname,
+	.poll          = datagram_poll,
+	.ioctl         = bcm_sock_no_ioctlcmd,
+	.gettstamp     = sock_gettstamp,
+	.listen        = sock_no_listen,
+	.shutdown      = sock_no_shutdown,
+	.sendmsg       = bcm_sendmsg,
+	.recvmsg       = bcm_recvmsg,
+	.mmap          = sock_no_mmap,
+};
+
+static struct proto bcm_proto __read_mostly = {
+	.name       = "CAN_BCM",
+	.owner      = THIS_MODULE,
+	.obj_size   = sizeof(struct bcm_sock),
+	.init       = bcm_init,
+};
+
+static const struct can_proto bcm_can_proto = {
+	.type       = SOCK_DGRAM,
+	.protocol   = CAN_BCM,
+	.ops        = &bcm_ops,
+	.prot       = &bcm_proto,
+};
+
+static int canbcm_pernet_init(struct net *net)
+{
+#if IS_ENABLED(CONFIG_PROC_FS)
+	/* create /proc/net/can-bcm directory */
+	net->can.bcmproc_dir = proc_net_mkdir(net, "can-bcm", net->proc_net);
+#endif /* CONFIG_PROC_FS */
+
+	return 0;
+}
+
+static void canbcm_pernet_exit(struct net *net)
+{
+#if IS_ENABLED(CONFIG_PROC_FS)
+	/* remove /proc/net/can-bcm directory */
+	if (net->can.bcmproc_dir)
+		remove_proc_entry("can-bcm", net->proc_net);
+#endif /* CONFIG_PROC_FS */
+}
+
+static struct pernet_operations canbcm_pernet_ops __read_mostly = {
+	.init = canbcm_pernet_init,
+	.exit = canbcm_pernet_exit,
+};
+
+static struct notifier_block canbcm_notifier = {
+	.notifier_call = bcm_notifier
+};
+
+static int __init bcm_module_init(void)
+{
+	int err;
+
+	bcm_wq = alloc_workqueue("can-bcm-wq", WQ_UNBOUND, 0);
+	if (!bcm_wq)
+		return -ENOMEM;
+
+	pr_info("can: broadcast manager protocol\n");
+
+	err = register_pernet_subsys(&canbcm_pernet_ops);
+	if (err)
+		goto register_pernet_failed;
+
+	err = register_netdevice_notifier(&canbcm_notifier);
+	if (err)
+		goto register_notifier_failed;
+
+	err = can_proto_register(&bcm_can_proto);
+	if (err < 0) {
+		printk(KERN_ERR "can: registration of bcm protocol failed\n");
+		goto register_proto_failed;
+	}
+
+	return 0;
+
+register_proto_failed:
+	unregister_netdevice_notifier(&canbcm_notifier);
+register_notifier_failed:
+	unregister_pernet_subsys(&canbcm_pernet_ops);
+register_pernet_failed:
+	destroy_workqueue(bcm_wq);
+	return err;
+}
+
+static void __exit bcm_module_exit(void)
+{
+	can_proto_unregister(&bcm_can_proto);
+	unregister_netdevice_notifier(&canbcm_notifier);
+	unregister_pernet_subsys(&canbcm_pernet_ops);
+	rcu_barrier();
+	destroy_workqueue(bcm_wq);
+}
+
+module_init(bcm_module_init);
+module_exit(bcm_module_exit);
diff --git a/net/can/gw.c b/net/can/gw.c
new file mode 100644
index 000000000..0ec99f68a
--- /dev/null
+++ b/net/can/gw.c
@@ -0,0 +1,1368 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* gw.c - CAN frame Gateway/Router/Bridge with netlink interface
+ *
+ * Copyright (c) 2019 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/gw.h>
+#include <net/can.h>
+#include <net/rtnetlink.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#define CAN_GW_NAME "can-gw"
+
+MODULE_DESCRIPTION("PF_CAN netlink gateway");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
+MODULE_ALIAS(CAN_GW_NAME);
+
+#define CGW_MIN_HOPS 1
+#define CGW_MAX_HOPS 6
+#define CGW_DEFAULT_HOPS 1
+
+static unsigned char max_hops __read_mostly = CGW_DEFAULT_HOPS;
+module_param(max_hops, byte, 0444);
+MODULE_PARM_DESC(max_hops,
+		 "maximum " CAN_GW_NAME " routing hops for CAN frames "
+		 "(valid values: " __stringify(CGW_MIN_HOPS) "-"
+		 __stringify(CGW_MAX_HOPS) " hops, "
+		 "default: " __stringify(CGW_DEFAULT_HOPS) ")");
+
+static struct notifier_block notifier;
+static struct kmem_cache *cgw_cache __read_mostly;
+
+/* structure that contains the (on-the-fly) CAN frame modifications */
+struct cf_mod {
+	struct {
+		struct canfd_frame and;
+		struct canfd_frame or;
+		struct canfd_frame xor;
+		struct canfd_frame set;
+	} modframe;
+	struct {
+		u8 and;
+		u8 or;
+		u8 xor;
+		u8 set;
+	} modtype;
+	void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf,
+					  struct cf_mod *mod);
+
+	/* CAN frame checksum calculation after CAN frame modifications */
+	struct {
+		struct cgw_csum_xor xor;
+		struct cgw_csum_crc8 crc8;
+	} csum;
+	struct {
+		void (*xor)(struct canfd_frame *cf,
+			    struct cgw_csum_xor *xor);
+		void (*crc8)(struct canfd_frame *cf,
+			     struct cgw_csum_crc8 *crc8);
+	} csumfunc;
+	u32 uid;
+};
+
+/* So far we just support CAN -> CAN routing and frame modifications.
+ *
+ * The internal can_can_gw structure contains data and attributes for
+ * a CAN -> CAN gateway job.
+ */
+struct can_can_gw {
+	struct can_filter filter;
+	int src_idx;
+	int dst_idx;
+};
+
+/* list entry for CAN gateways jobs */
+struct cgw_job {
+	struct hlist_node list;
+	struct rcu_head rcu;
+	u32 handled_frames;
+	u32 dropped_frames;
+	u32 deleted_frames;
+	struct cf_mod __rcu *cf_mod;
+	union {
+		/* CAN frame data source */
+		struct net_device *dev;
+	} src;
+	union {
+		/* CAN frame data destination */
+		struct net_device *dev;
+	} dst;
+	union {
+		struct can_can_gw ccgw;
+		/* tbc */
+	};
+	u8 gwtype;
+	u8 limit_hops;
+	u16 flags;
+};
+
+/* modification functions that are invoked in the hot path in can_can_gw_rcv */
+
+#define MODFUNC(func, op) static void func(struct canfd_frame *cf, \
+					   struct cf_mod *mod) { op ; }
+
+MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id)
+MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len)
+MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags)
+MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data)
+MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id)
+MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len)
+MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags)
+MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data)
+MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id)
+MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len)
+MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags)
+MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data)
+MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id)
+MODFUNC(mod_set_len, cf->len = mod->modframe.set.len)
+MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags)
+MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data)
+
+static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	int i;
+
+	for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+		*(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i);
+}
+
+static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	int i;
+
+	for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+		*(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i);
+}
+
+static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	int i;
+
+	for (i = 0; i < CANFD_MAX_DLEN; i += 8)
+		*(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i);
+}
+
+static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN);
+}
+
+/* retrieve valid CC DLC value and store it into 'len' */
+static void mod_retrieve_ccdlc(struct canfd_frame *cf)
+{
+	struct can_frame *ccf = (struct can_frame *)cf;
+
+	/* len8_dlc is only valid if len == CAN_MAX_DLEN */
+	if (ccf->len != CAN_MAX_DLEN)
+		return;
+
+	/* do we have a valid len8_dlc value from 9 .. 15 ? */
+	if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC)
+		ccf->len = ccf->len8_dlc;
+}
+
+/* convert valid CC DLC value in 'len' into struct can_frame elements */
+static void mod_store_ccdlc(struct canfd_frame *cf)
+{
+	struct can_frame *ccf = (struct can_frame *)cf;
+
+	/* clear potential leftovers */
+	ccf->len8_dlc = 0;
+
+	/* plain data length 0 .. 8 - that was easy */
+	if (ccf->len <= CAN_MAX_DLEN)
+		return;
+
+	/* potentially broken values are caught in can_can_gw_rcv() */
+	if (ccf->len > CAN_MAX_RAW_DLC)
+		return;
+
+	/* we have a valid dlc value from 9 .. 15 in ccf->len */
+	ccf->len8_dlc = ccf->len;
+	ccf->len = CAN_MAX_DLEN;
+}
+
+static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	mod_retrieve_ccdlc(cf);
+	mod_and_len(cf, mod);
+	mod_store_ccdlc(cf);
+}
+
+static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	mod_retrieve_ccdlc(cf);
+	mod_or_len(cf, mod);
+	mod_store_ccdlc(cf);
+}
+
+static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	mod_retrieve_ccdlc(cf);
+	mod_xor_len(cf, mod);
+	mod_store_ccdlc(cf);
+}
+
+static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod)
+{
+	mod_set_len(cf, mod);
+	mod_store_ccdlc(cf);
+}
+
+static void canframecpy(struct canfd_frame *dst, struct can_frame *src)
+{
+	/* Copy the struct members separately to ensure that no uninitialized
+	 * data are copied in the 3 bytes hole of the struct. This is needed
+	 * to make easy compares of the data in the struct cf_mod.
+	 */
+
+	dst->can_id = src->can_id;
+	dst->len = src->len;
+	*(u64 *)dst->data = *(u64 *)src->data;
+}
+
+static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src)
+{
+	/* Copy the struct members separately to ensure that no uninitialized
+	 * data are copied in the 2 bytes hole of the struct. This is needed
+	 * to make easy compares of the data in the struct cf_mod.
+	 */
+
+	dst->can_id = src->can_id;
+	dst->flags = src->flags;
+	dst->len = src->len;
+	memcpy(dst->data, src->data, CANFD_MAX_DLEN);
+}
+
+static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r)
+{
+	s8 dlen = CAN_MAX_DLEN;
+
+	if (r->flags & CGW_FLAGS_CAN_FD)
+		dlen = CANFD_MAX_DLEN;
+
+	/* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0]
+	 * relative to received dlc -1 .. -8 :
+	 * e.g. for received dlc = 8
+	 * -1 => index = 7 (data[7])
+	 * -3 => index = 5 (data[5])
+	 * -8 => index = 0 (data[0])
+	 */
+
+	if (fr >= -dlen && fr < dlen &&
+	    to >= -dlen && to < dlen &&
+	    re >= -dlen && re < dlen)
+		return 0;
+	else
+		return -EINVAL;
+}
+
+static inline int calc_idx(int idx, int rx_len)
+{
+	if (idx < 0)
+		return rx_len + idx;
+	else
+		return idx;
+}
+
+static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+	int from = calc_idx(xor->from_idx, cf->len);
+	int to = calc_idx(xor->to_idx, cf->len);
+	int res = calc_idx(xor->result_idx, cf->len);
+	u8 val = xor->init_xor_val;
+	int i;
+
+	if (from < 0 || to < 0 || res < 0)
+		return;
+
+	if (from <= to) {
+		for (i = from; i <= to; i++)
+			val ^= cf->data[i];
+	} else {
+		for (i = from; i >= to; i--)
+			val ^= cf->data[i];
+	}
+
+	cf->data[res] = val;
+}
+
+static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+	u8 val = xor->init_xor_val;
+	int i;
+
+	for (i = xor->from_idx; i <= xor->to_idx; i++)
+		val ^= cf->data[i];
+
+	cf->data[xor->result_idx] = val;
+}
+
+static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor)
+{
+	u8 val = xor->init_xor_val;
+	int i;
+
+	for (i = xor->from_idx; i >= xor->to_idx; i--)
+		val ^= cf->data[i];
+
+	cf->data[xor->result_idx] = val;
+}
+
+static void cgw_csum_crc8_rel(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
+{
+	int from = calc_idx(crc8->from_idx, cf->len);
+	int to = calc_idx(crc8->to_idx, cf->len);
+	int res = calc_idx(crc8->result_idx, cf->len);
+	u8 crc = crc8->init_crc_val;
+	int i;
+
+	if (from < 0 || to < 0 || res < 0)
+		return;
+
+	if (from <= to) {
+		for (i = from; i <= to; i++)
+			crc = crc8->crctab[crc ^ cf->data[i]];
+	} else {
+		for (i = from; i >= to; i--)
+			crc = crc8->crctab[crc ^ cf->data[i]];
+	}
+
+	switch (crc8->profile) {
+	case CGW_CRC8PRF_1U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+		break;
+
+	case  CGW_CRC8PRF_16U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+		break;
+
+	case CGW_CRC8PRF_SFFID_XOR:
+		crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+				   (cf->can_id >> 8 & 0xFF)];
+		break;
+	}
+
+	cf->data[res] = crc ^ crc8->final_xor_val;
+}
+
+static void cgw_csum_crc8_pos(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
+{
+	u8 crc = crc8->init_crc_val;
+	int i;
+
+	for (i = crc8->from_idx; i <= crc8->to_idx; i++)
+		crc = crc8->crctab[crc ^ cf->data[i]];
+
+	switch (crc8->profile) {
+	case CGW_CRC8PRF_1U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+		break;
+
+	case  CGW_CRC8PRF_16U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+		break;
+
+	case CGW_CRC8PRF_SFFID_XOR:
+		crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+				   (cf->can_id >> 8 & 0xFF)];
+		break;
+	}
+
+	cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
+}
+
+static void cgw_csum_crc8_neg(struct canfd_frame *cf,
+			      struct cgw_csum_crc8 *crc8)
+{
+	u8 crc = crc8->init_crc_val;
+	int i;
+
+	for (i = crc8->from_idx; i >= crc8->to_idx; i--)
+		crc = crc8->crctab[crc ^ cf->data[i]];
+
+	switch (crc8->profile) {
+	case CGW_CRC8PRF_1U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[0]];
+		break;
+
+	case  CGW_CRC8PRF_16U8:
+		crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]];
+		break;
+
+	case CGW_CRC8PRF_SFFID_XOR:
+		crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^
+				   (cf->can_id >> 8 & 0xFF)];
+		break;
+	}
+
+	cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val;
+}
+
+/* the receive & process & send function */
+static void can_can_gw_rcv(struct sk_buff *skb, void *data)
+{
+	struct cgw_job *gwj = (struct cgw_job *)data;
+	struct canfd_frame *cf;
+	struct sk_buff *nskb;
+	struct can_skb_ext *csx, *ncsx;
+	struct cf_mod *mod;
+	int modidx = 0;
+
+	/* process strictly Classic CAN or CAN FD frames */
+	if (gwj->flags & CGW_FLAGS_CAN_FD) {
+		if (!can_is_canfd_skb(skb))
+			return;
+	} else {
+		if (!can_is_can_skb(skb))
+			return;
+	}
+
+	csx = can_skb_ext_find(skb);
+	if (!csx)
+		return;
+
+	/* Do not handle CAN frames routed more than 'max_hops' times.
+	 * In general we should never catch this delimiter which is intended
+	 * to cover a misconfiguration protection (e.g. circular CAN routes).
+	 */
+	if (csx->can_gw_hops >= max_hops) {
+		/* indicate deleted frames due to misconfiguration */
+		gwj->deleted_frames++;
+		return;
+	}
+
+	if (!(gwj->dst.dev->flags & IFF_UP)) {
+		gwj->dropped_frames++;
+		return;
+	}
+
+	/* is sending the skb back to the incoming interface not allowed? */
+	if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
+	    csx->can_iif == gwj->dst.dev->ifindex)
+		return;
+
+	/* clone the given skb, which has not been done in can_rcv()
+	 *
+	 * When there is at least one modification function activated,
+	 * we need to copy the skb as we want to modify skb->data.
+	 */
+	mod = rcu_dereference(gwj->cf_mod);
+	if (mod->modfunc[0])
+		nskb = skb_copy(skb, GFP_ATOMIC);
+	else
+		nskb = skb_clone(skb, GFP_ATOMIC);
+
+	if (!nskb) {
+		gwj->dropped_frames++;
+		return;
+	}
+
+	/* the cloned/copied nskb points to the skb extension of the original
+	 * skb with an increased refcount. skb_ext_add() creates a copy to
+	 * separate the skb extension data to modify the can_gw_hops.
+	 */
+	ncsx = skb_ext_add(nskb, SKB_EXT_CAN);
+	if (!ncsx) {
+		kfree_skb(nskb);
+		gwj->dropped_frames++;
+		return;
+	}
+
+	/* put the incremented hop counter in the cloned skb */
+	ncsx->can_gw_hops = csx->can_gw_hops + 1;
+
+	/* first processing of this CAN frame -> adjust to private hop limit */
+	if (gwj->limit_hops && ncsx->can_gw_hops == 1)
+		ncsx->can_gw_hops = max_hops - gwj->limit_hops + 1;
+
+	nskb->dev = gwj->dst.dev;
+
+	/* pointer to modifiable CAN frame */
+	cf = (struct canfd_frame *)nskb->data;
+
+	/* perform preprocessed modification functions if there are any */
+	while (modidx < MAX_MODFUNCTIONS && mod->modfunc[modidx])
+		(*mod->modfunc[modidx++])(cf, mod);
+
+	/* Has the CAN frame been modified? */
+	if (modidx) {
+		/* get available space for the processed CAN frame type */
+		int max_len = nskb->len - offsetof(struct canfd_frame, data);
+
+		/* dlc may have changed, make sure it fits to the CAN frame */
+		if (cf->len > max_len) {
+			/* delete frame due to misconfiguration */
+			gwj->deleted_frames++;
+			kfree_skb(nskb);
+			return;
+		}
+
+		/* check for checksum updates */
+		if (mod->csumfunc.crc8)
+			(*mod->csumfunc.crc8)(cf, &mod->csum.crc8);
+
+		if (mod->csumfunc.xor)
+			(*mod->csumfunc.xor)(cf, &mod->csum.xor);
+	}
+
+	/* clear the skb timestamp if not configured the other way */
+	if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP))
+		nskb->tstamp = 0;
+
+	/* send to netdevice */
+	if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO))
+		gwj->dropped_frames++;
+	else
+		gwj->handled_frames++;
+}
+
+static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
+{
+	return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
+			       gwj->ccgw.filter.can_mask, can_can_gw_rcv,
+			       gwj, "gw", NULL);
+}
+
+static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
+{
+	can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
+			  gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
+}
+
+static void cgw_job_free_rcu(struct rcu_head *rcu_head)
+{
+	struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu);
+
+	/* cgw_job::cf_mod is always accessed from the same cgw_job object within
+	 * the same RCU read section. Once cgw_job is scheduled for removal,
+	 * cf_mod can also be removed without mandating an additional grace period.
+	 */
+	kfree(rcu_access_pointer(gwj->cf_mod));
+	kmem_cache_free(cgw_cache, gwj);
+}
+
+/* Return cgw_job::cf_mod with RTNL protected section */
+static struct cf_mod *cgw_job_cf_mod(struct cgw_job *gwj)
+{
+	return rcu_dereference_protected(gwj->cf_mod, rtnl_is_locked());
+}
+
+static int cgw_notifier(struct notifier_block *nb,
+			unsigned long msg, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct net *net = dev_net(dev);
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+
+	if (msg == NETDEV_UNREGISTER) {
+		struct cgw_job *gwj = NULL;
+		struct hlist_node *nx;
+
+		ASSERT_RTNL();
+
+		hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+			if (gwj->src.dev == dev || gwj->dst.dev == dev) {
+				hlist_del(&gwj->list);
+				cgw_unregister_filter(net, gwj);
+				call_rcu(&gwj->rcu, cgw_job_free_rcu);
+			}
+		}
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
+		       u32 pid, u32 seq, int flags)
+{
+	struct rtcanmsg *rtcan;
+	struct nlmsghdr *nlh;
+	struct cf_mod *mod;
+
+	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	rtcan = nlmsg_data(nlh);
+	rtcan->can_family = AF_CAN;
+	rtcan->gwtype = gwj->gwtype;
+	rtcan->flags = gwj->flags;
+
+	/* add statistics if available */
+
+	if (gwj->handled_frames) {
+		if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0)
+			goto cancel;
+	}
+
+	if (gwj->dropped_frames) {
+		if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0)
+			goto cancel;
+	}
+
+	if (gwj->deleted_frames) {
+		if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
+			goto cancel;
+	}
+
+	/* check non default settings of attributes */
+
+	if (gwj->limit_hops) {
+		if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0)
+			goto cancel;
+	}
+
+	mod = cgw_job_cf_mod(gwj);
+	if (gwj->flags & CGW_FLAGS_CAN_FD) {
+		struct cgw_fdframe_mod mb;
+
+		if (mod->modtype.and) {
+			memcpy(&mb.cf, &mod->modframe.and, sizeof(mb.cf));
+			mb.modtype = mod->modtype.and;
+			if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.or) {
+			memcpy(&mb.cf, &mod->modframe.or, sizeof(mb.cf));
+			mb.modtype = mod->modtype.or;
+			if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.xor) {
+			memcpy(&mb.cf, &mod->modframe.xor, sizeof(mb.cf));
+			mb.modtype = mod->modtype.xor;
+			if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.set) {
+			memcpy(&mb.cf, &mod->modframe.set, sizeof(mb.cf));
+			mb.modtype = mod->modtype.set;
+			if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+	} else {
+		struct cgw_frame_mod mb;
+
+		if (mod->modtype.and) {
+			memcpy(&mb.cf, &mod->modframe.and, sizeof(mb.cf));
+			mb.modtype = mod->modtype.and;
+			if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.or) {
+			memcpy(&mb.cf, &mod->modframe.or, sizeof(mb.cf));
+			mb.modtype = mod->modtype.or;
+			if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.xor) {
+			memcpy(&mb.cf, &mod->modframe.xor, sizeof(mb.cf));
+			mb.modtype = mod->modtype.xor;
+			if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+
+		if (mod->modtype.set) {
+			memcpy(&mb.cf, &mod->modframe.set, sizeof(mb.cf));
+			mb.modtype = mod->modtype.set;
+			if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0)
+				goto cancel;
+		}
+	}
+
+	if (mod->uid) {
+		if (nla_put_u32(skb, CGW_MOD_UID, mod->uid) < 0)
+			goto cancel;
+	}
+
+	if (mod->csumfunc.crc8) {
+		if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
+			    &mod->csum.crc8) < 0)
+			goto cancel;
+	}
+
+	if (mod->csumfunc.xor) {
+		if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN,
+			    &mod->csum.xor) < 0)
+			goto cancel;
+	}
+
+	if (gwj->gwtype == CGW_TYPE_CAN_CAN) {
+		if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) {
+			if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter),
+				    &gwj->ccgw.filter) < 0)
+				goto cancel;
+		}
+
+		if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0)
+			goto cancel;
+
+		if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0)
+			goto cancel;
+	}
+
+	nlmsg_end(skb, nlh);
+	return 0;
+
+cancel:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+/* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */
+static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct cgw_job *gwj = NULL;
+	int idx = 0;
+	int s_idx = cb->args[0];
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) {
+		if (idx < s_idx)
+			goto cont;
+
+		if (cgw_put_job(skb, gwj, RTM_NEWROUTE,
+				NETLINK_CB(cb->skb).portid,
+				cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0)
+			break;
+cont:
+		idx++;
+	}
+	rcu_read_unlock();
+
+	cb->args[0] = idx;
+
+	return skb->len;
+}
+
+static const struct nla_policy cgw_policy[CGW_MAX + 1] = {
+	[CGW_MOD_AND]	= { .len = sizeof(struct cgw_frame_mod) },
+	[CGW_MOD_OR]	= { .len = sizeof(struct cgw_frame_mod) },
+	[CGW_MOD_XOR]	= { .len = sizeof(struct cgw_frame_mod) },
+	[CGW_MOD_SET]	= { .len = sizeof(struct cgw_frame_mod) },
+	[CGW_CS_XOR]	= { .len = sizeof(struct cgw_csum_xor) },
+	[CGW_CS_CRC8]	= { .len = sizeof(struct cgw_csum_crc8) },
+	[CGW_SRC_IF]	= { .type = NLA_U32 },
+	[CGW_DST_IF]	= { .type = NLA_U32 },
+	[CGW_FILTER]	= { .len = sizeof(struct can_filter) },
+	[CGW_LIM_HOPS]	= { .type = NLA_U8 },
+	[CGW_MOD_UID]	= { .type = NLA_U32 },
+	[CGW_FDMOD_AND]	= { .len = sizeof(struct cgw_fdframe_mod) },
+	[CGW_FDMOD_OR]	= { .len = sizeof(struct cgw_fdframe_mod) },
+	[CGW_FDMOD_XOR]	= { .len = sizeof(struct cgw_fdframe_mod) },
+	[CGW_FDMOD_SET]	= { .len = sizeof(struct cgw_fdframe_mod) },
+};
+
+/* check for common and gwtype specific attributes */
+static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
+			  u8 gwtype, void *gwtypeattr, u8 *limhops)
+{
+	struct nlattr *tb[CGW_MAX + 1];
+	struct rtcanmsg *r = nlmsg_data(nlh);
+	int modidx = 0;
+	int err = 0;
+
+	/* initialize modification & checksum data space */
+	memset(mod, 0, sizeof(*mod));
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb,
+				     CGW_MAX, cgw_policy, NULL);
+	if (err < 0)
+		return err;
+
+	if (tb[CGW_LIM_HOPS]) {
+		*limhops = nla_get_u8(tb[CGW_LIM_HOPS]);
+
+		if (*limhops < 1 || *limhops > max_hops)
+			return -EINVAL;
+	}
+
+	/* check for AND/OR/XOR/SET modifications */
+	if (r->flags & CGW_FLAGS_CAN_FD) {
+		struct cgw_fdframe_mod mb;
+
+		if (tb[CGW_FDMOD_AND]) {
+			nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN);
+
+			canfdframecpy(&mod->modframe.and, &mb.cf);
+			mod->modtype.and = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_and_id;
+
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_and_len;
+
+			if (mb.modtype & CGW_MOD_FLAGS)
+				mod->modfunc[modidx++] = mod_and_flags;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_and_fddata;
+		}
+
+		if (tb[CGW_FDMOD_OR]) {
+			nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN);
+
+			canfdframecpy(&mod->modframe.or, &mb.cf);
+			mod->modtype.or = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_or_id;
+
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_or_len;
+
+			if (mb.modtype & CGW_MOD_FLAGS)
+				mod->modfunc[modidx++] = mod_or_flags;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_or_fddata;
+		}
+
+		if (tb[CGW_FDMOD_XOR]) {
+			nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN);
+
+			canfdframecpy(&mod->modframe.xor, &mb.cf);
+			mod->modtype.xor = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_xor_id;
+
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_xor_len;
+
+			if (mb.modtype & CGW_MOD_FLAGS)
+				mod->modfunc[modidx++] = mod_xor_flags;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_xor_fddata;
+		}
+
+		if (tb[CGW_FDMOD_SET]) {
+			nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN);
+
+			canfdframecpy(&mod->modframe.set, &mb.cf);
+			mod->modtype.set = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_set_id;
+
+			if (mb.modtype & CGW_MOD_LEN)
+				mod->modfunc[modidx++] = mod_set_len;
+
+			if (mb.modtype & CGW_MOD_FLAGS)
+				mod->modfunc[modidx++] = mod_set_flags;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_set_fddata;
+		}
+	} else {
+		struct cgw_frame_mod mb;
+
+		if (tb[CGW_MOD_AND]) {
+			nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN);
+
+			canframecpy(&mod->modframe.and, &mb.cf);
+			mod->modtype.and = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_and_id;
+
+			if (mb.modtype & CGW_MOD_DLC)
+				mod->modfunc[modidx++] = mod_and_ccdlc;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_and_data;
+		}
+
+		if (tb[CGW_MOD_OR]) {
+			nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN);
+
+			canframecpy(&mod->modframe.or, &mb.cf);
+			mod->modtype.or = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_or_id;
+
+			if (mb.modtype & CGW_MOD_DLC)
+				mod->modfunc[modidx++] = mod_or_ccdlc;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_or_data;
+		}
+
+		if (tb[CGW_MOD_XOR]) {
+			nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN);
+
+			canframecpy(&mod->modframe.xor, &mb.cf);
+			mod->modtype.xor = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_xor_id;
+
+			if (mb.modtype & CGW_MOD_DLC)
+				mod->modfunc[modidx++] = mod_xor_ccdlc;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_xor_data;
+		}
+
+		if (tb[CGW_MOD_SET]) {
+			nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN);
+
+			canframecpy(&mod->modframe.set, &mb.cf);
+			mod->modtype.set = mb.modtype;
+
+			if (mb.modtype & CGW_MOD_ID)
+				mod->modfunc[modidx++] = mod_set_id;
+
+			if (mb.modtype & CGW_MOD_DLC)
+				mod->modfunc[modidx++] = mod_set_ccdlc;
+
+			if (mb.modtype & CGW_MOD_DATA)
+				mod->modfunc[modidx++] = mod_set_data;
+		}
+	}
+
+	/* check for checksum operations after CAN frame modifications */
+	if (modidx) {
+		if (tb[CGW_CS_CRC8]) {
+			struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]);
+
+			err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
+						 c->result_idx, r);
+			if (err)
+				return err;
+
+			nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8],
+				   CGW_CS_CRC8_LEN);
+
+			/* select dedicated processing function to reduce
+			 * runtime operations in receive hot path.
+			 */
+			if (c->from_idx < 0 || c->to_idx < 0 ||
+			    c->result_idx < 0)
+				mod->csumfunc.crc8 = cgw_csum_crc8_rel;
+			else if (c->from_idx <= c->to_idx)
+				mod->csumfunc.crc8 = cgw_csum_crc8_pos;
+			else
+				mod->csumfunc.crc8 = cgw_csum_crc8_neg;
+		}
+
+		if (tb[CGW_CS_XOR]) {
+			struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]);
+
+			err = cgw_chk_csum_parms(c->from_idx, c->to_idx,
+						 c->result_idx, r);
+			if (err)
+				return err;
+
+			nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR],
+				   CGW_CS_XOR_LEN);
+
+			/* select dedicated processing function to reduce
+			 * runtime operations in receive hot path.
+			 */
+			if (c->from_idx < 0 || c->to_idx < 0 ||
+			    c->result_idx < 0)
+				mod->csumfunc.xor = cgw_csum_xor_rel;
+			else if (c->from_idx <= c->to_idx)
+				mod->csumfunc.xor = cgw_csum_xor_pos;
+			else
+				mod->csumfunc.xor = cgw_csum_xor_neg;
+		}
+
+		if (tb[CGW_MOD_UID])
+			nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
+	}
+
+	if (gwtype == CGW_TYPE_CAN_CAN) {
+		/* check CGW_TYPE_CAN_CAN specific attributes */
+		struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr;
+
+		memset(ccgw, 0, sizeof(*ccgw));
+
+		/* check for can_filter in attributes */
+		if (tb[CGW_FILTER])
+			nla_memcpy(&ccgw->filter, tb[CGW_FILTER],
+				   sizeof(struct can_filter));
+
+		err = -ENODEV;
+
+		/* specifying two interfaces is mandatory */
+		if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF])
+			return err;
+
+		ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]);
+		ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]);
+
+		/* both indices set to 0 for flushing all routing entries */
+		if (!ccgw->src_idx && !ccgw->dst_idx)
+			return 0;
+
+		/* only one index set to 0 is an error */
+		if (!ccgw->src_idx || !ccgw->dst_idx)
+			return err;
+	}
+
+	/* add the checks for other gwtypes here */
+
+	return 0;
+}
+
+static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct rtcanmsg *r;
+	struct cgw_job *gwj;
+	struct cf_mod *mod;
+	struct can_can_gw ccgw;
+	u8 limhops = 0;
+	int err = 0;
+
+	if (!netlink_capable(skb, CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (nlmsg_len(nlh) < sizeof(*r))
+		return -EINVAL;
+
+	r = nlmsg_data(nlh);
+	if (r->can_family != AF_CAN)
+		return -EPFNOSUPPORT;
+
+	/* so far we only support CAN -> CAN routings */
+	if (r->gwtype != CGW_TYPE_CAN_CAN)
+		return -EINVAL;
+
+	mod = kmalloc_obj(*mod);
+	if (!mod)
+		return -ENOMEM;
+
+	err = cgw_parse_attr(nlh, mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
+	if (err < 0)
+		goto out_free_cf;
+
+	if (mod->uid) {
+		ASSERT_RTNL();
+
+		/* check for updating an existing job with identical uid */
+		hlist_for_each_entry(gwj, &net->can.cgw_list, list) {
+			struct cf_mod *old_cf;
+
+			old_cf = cgw_job_cf_mod(gwj);
+			if (old_cf->uid != mod->uid)
+				continue;
+
+			/* interfaces & filters must be identical */
+			if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) {
+				err = -EINVAL;
+				goto out_free_cf;
+			}
+
+			rcu_assign_pointer(gwj->cf_mod, mod);
+			kfree_rcu_mightsleep(old_cf);
+			return 0;
+		}
+	}
+
+	/* ifindex == 0 is not allowed for job creation */
+	if (!ccgw.src_idx || !ccgw.dst_idx) {
+		err = -ENODEV;
+		goto out_free_cf;
+	}
+
+	gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
+	if (!gwj) {
+		err = -ENOMEM;
+		goto out_free_cf;
+	}
+
+	gwj->handled_frames = 0;
+	gwj->dropped_frames = 0;
+	gwj->deleted_frames = 0;
+	gwj->flags = r->flags;
+	gwj->gwtype = r->gwtype;
+	gwj->limit_hops = limhops;
+
+	/* insert already parsed information */
+	RCU_INIT_POINTER(gwj->cf_mod, mod);
+	memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
+
+	err = -ENODEV;
+
+	gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx);
+
+	if (!gwj->src.dev)
+		goto out;
+
+	if (gwj->src.dev->type != ARPHRD_CAN)
+		goto out;
+
+	gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx);
+
+	if (!gwj->dst.dev)
+		goto out;
+
+	if (gwj->dst.dev->type != ARPHRD_CAN)
+		goto out;
+
+	/* is sending the skb back to the incoming interface intended? */
+	if (gwj->src.dev == gwj->dst.dev &&
+	    !(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	ASSERT_RTNL();
+
+	err = cgw_register_filter(net, gwj);
+	if (!err)
+		hlist_add_head_rcu(&gwj->list, &net->can.cgw_list);
+out:
+	if (err) {
+		kmem_cache_free(cgw_cache, gwj);
+out_free_cf:
+		kfree(mod);
+	}
+	return err;
+}
+
+static void cgw_remove_all_jobs(struct net *net)
+{
+	struct cgw_job *gwj = NULL;
+	struct hlist_node *nx;
+
+	ASSERT_RTNL();
+
+	hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+		hlist_del(&gwj->list);
+		cgw_unregister_filter(net, gwj);
+		call_rcu(&gwj->rcu, cgw_job_free_rcu);
+	}
+}
+
+static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct cgw_job *gwj = NULL;
+	struct hlist_node *nx;
+	struct rtcanmsg *r;
+	struct cf_mod mod;
+	struct can_can_gw ccgw;
+	u8 limhops = 0;
+	int err = 0;
+
+	if (!netlink_capable(skb, CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (nlmsg_len(nlh) < sizeof(*r))
+		return -EINVAL;
+
+	r = nlmsg_data(nlh);
+	if (r->can_family != AF_CAN)
+		return -EPFNOSUPPORT;
+
+	/* so far we only support CAN -> CAN routings */
+	if (r->gwtype != CGW_TYPE_CAN_CAN)
+		return -EINVAL;
+
+	err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
+	if (err < 0)
+		return err;
+
+	/* two interface indices both set to 0 => remove all entries */
+	if (!ccgw.src_idx && !ccgw.dst_idx) {
+		cgw_remove_all_jobs(net);
+		return 0;
+	}
+
+	err = -EINVAL;
+
+	ASSERT_RTNL();
+
+	/* remove only the first matching entry */
+	hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) {
+		struct cf_mod *cf_mod;
+
+		if (gwj->flags != r->flags)
+			continue;
+
+		if (gwj->limit_hops != limhops)
+			continue;
+
+		cf_mod = cgw_job_cf_mod(gwj);
+		/* we have a match when uid is enabled and identical */
+		if (cf_mod->uid || mod.uid) {
+			if (cf_mod->uid != mod.uid)
+				continue;
+		} else {
+			/* no uid => check for identical modifications */
+			if (memcmp(cf_mod, &mod, sizeof(mod)))
+				continue;
+		}
+
+		/* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
+		if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
+			continue;
+
+		hlist_del(&gwj->list);
+		cgw_unregister_filter(net, gwj);
+		call_rcu(&gwj->rcu, cgw_job_free_rcu);
+		err = 0;
+		break;
+	}
+
+	return err;
+}
+
+static int __net_init cangw_pernet_init(struct net *net)
+{
+	INIT_HLIST_HEAD(&net->can.cgw_list);
+	return 0;
+}
+
+static void __net_exit cangw_pernet_exit_batch(struct list_head *net_list)
+{
+	struct net *net;
+
+	rtnl_lock();
+	list_for_each_entry(net, net_list, exit_list)
+		cgw_remove_all_jobs(net);
+	rtnl_unlock();
+}
+
+static struct pernet_operations cangw_pernet_ops = {
+	.init = cangw_pernet_init,
+	.exit_batch = cangw_pernet_exit_batch,
+};
+
+static const struct rtnl_msg_handler cgw_rtnl_msg_handlers[] __initconst_or_module = {
+	{.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_NEWROUTE,
+	 .doit = cgw_create_job},
+	{.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_DELROUTE,
+	 .doit = cgw_remove_job},
+	{.owner = THIS_MODULE, .protocol = PF_CAN, .msgtype = RTM_GETROUTE,
+	 .dumpit = cgw_dump_jobs},
+};
+
+static __init int cgw_module_init(void)
+{
+	int ret;
+
+	/* sanitize given module parameter */
+	max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
+
+	pr_info("can: netlink gateway - max_hops=%d\n",	max_hops);
+
+	ret = register_pernet_subsys(&cangw_pernet_ops);
+	if (ret)
+		return ret;
+
+	ret = -ENOMEM;
+	cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
+				      0, 0, NULL);
+	if (!cgw_cache)
+		goto out_cache_create;
+
+	/* set notifier */
+	notifier.notifier_call = cgw_notifier;
+	ret = register_netdevice_notifier(&notifier);
+	if (ret)
+		goto out_register_notifier;
+
+	ret = rtnl_register_many(cgw_rtnl_msg_handlers);
+	if (ret)
+		goto out_rtnl_register;
+
+	return 0;
+
+out_rtnl_register:
+	unregister_netdevice_notifier(&notifier);
+out_register_notifier:
+	kmem_cache_destroy(cgw_cache);
+out_cache_create:
+	unregister_pernet_subsys(&cangw_pernet_ops);
+
+	return ret;
+}
+
+static __exit void cgw_module_exit(void)
+{
+	rtnl_unregister_all(PF_CAN);
+
+	unregister_netdevice_notifier(&notifier);
+
+	unregister_pernet_subsys(&cangw_pernet_ops);
+	rcu_barrier(); /* Wait for completion of call_rcu()'s */
+
+	kmem_cache_destroy(cgw_cache);
+}
+
+module_init(cgw_module_init);
+module_exit(cgw_module_exit);
diff --git a/net/can/isotp.c b/net/can/isotp.c
new file mode 100644
index 000000000..155530aed
--- /dev/null
+++ b/net/can/isotp.c
@@ -0,0 +1,2074 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
+ *
+ * This implementation does not provide ISO-TP specific return values to the
+ * userspace.
+ *
+ * - RX path timeout of data reception leads to -ETIMEDOUT
+ * - RX path SN mismatch leads to -EILSEQ
+ * - RX path data reception with wrong padding leads to -EBADMSG
+ * - TX path flowcontrol reception timeout leads to -ECOMM
+ * - TX path flowcontrol reception overflow leads to -EMSGSIZE
+ * - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
+ * - when a transfer (tx) is on the run the next write() blocks until it's done
+ * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
+ * - as we have static buffers the check whether the PDU fits into the buffer
+ *   is done at FF reception time (no support for sending 'wait frames')
+ *
+ * Copyright (c) 2020 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/hrtimer.h>
+#include <linux/wait.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/isotp.h>
+#include <linux/slab.h>
+#include <net/can.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+MODULE_DESCRIPTION("PF_CAN ISO 15765-2 transport protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
+MODULE_ALIAS("can-proto-6");
+
+#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
+
+#define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \
+			 (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
+			 (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
+
+/* Since ISO 15765-2:2016 the CAN isotp protocol supports more than 4095
+ * byte per ISO PDU as the FF_DL can take full 32 bit values (4 Gbyte).
+ * We would need some good concept to handle this between user space and
+ * kernel space. For now set the static buffer to something about 8 kbyte
+ * to be able to test this new functionality.
+ */
+#define DEFAULT_MAX_PDU_SIZE 8300
+
+/* maximum PDU size before ISO 15765-2:2016 extension was 4095 */
+#define MAX_12BIT_PDU_SIZE 4095
+
+/* limit the isotp pdu size from the optional module parameter to 1MByte */
+#define MAX_PDU_SIZE (1025 * 1024U)
+
+static unsigned int max_pdu_size __read_mostly = DEFAULT_MAX_PDU_SIZE;
+module_param(max_pdu_size, uint, 0444);
+MODULE_PARM_DESC(max_pdu_size, "maximum isotp pdu size (default "
+		 __stringify(DEFAULT_MAX_PDU_SIZE) ")");
+
+/* N_PCI type values in bits 7-4 of N_PCI bytes */
+#define N_PCI_SF 0x00	/* single frame */
+#define N_PCI_FF 0x10	/* first frame */
+#define N_PCI_CF 0x20	/* consecutive frame */
+#define N_PCI_FC 0x30	/* flow control */
+
+#define N_PCI_SZ 1	/* size of the PCI byte #1 */
+#define SF_PCI_SZ4 1	/* size of SingleFrame PCI including 4 bit SF_DL */
+#define SF_PCI_SZ8 2	/* size of SingleFrame PCI including 8 bit SF_DL */
+#define FF_PCI_SZ12 2	/* size of FirstFrame PCI including 12 bit FF_DL */
+#define FF_PCI_SZ32 6	/* size of FirstFrame PCI including 32 bit FF_DL */
+#define FC_CONTENT_SZ 3	/* flow control content size in byte (FS/BS/STmin) */
+
+#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
+#define ISOTP_ALL_BC_FLAGS (CAN_ISOTP_SF_BROADCAST | CAN_ISOTP_CF_BROADCAST)
+
+/* Flow Status given in FC frame */
+#define ISOTP_FC_CTS 0		/* clear to send */
+#define ISOTP_FC_WT 1		/* wait */
+#define ISOTP_FC_OVFLW 2	/* overflow */
+
+#define ISOTP_FC_TIMEOUT 1	/* 1 sec */
+#define ISOTP_ECHO_TIMEOUT 2	/* 2 secs */
+
+/* so->tx_result[so->tx_gen % ISOTP_TX_RESULT_SLOTS] holds the packed value
+ * (err << ISOTP_TX_RESULT_GEN_BITS | gen) for each tx generation slot, so it
+ * can be handled with a single READ_ONCE()/WRITE_ONCE() access.
+ */
+#define ISOTP_TX_RESULT_SLOTS 4
+#define ISOTP_TX_RESULT_GEN_BITS 24
+#define ISOTP_TX_RESULT_GEN_MASK ((1U << ISOTP_TX_RESULT_GEN_BITS) - 1)
+#define ISOTP_TX_RESULT_ERR_MASK 0xFF
+
+enum {
+	ISOTP_IDLE = 0,
+	ISOTP_WAIT_FIRST_FC,
+	ISOTP_WAIT_FC,
+	ISOTP_WAIT_DATA,
+	ISOTP_SENDING,
+	ISOTP_SHUTDOWN,
+};
+
+struct tpcon {
+	u8 *buf;
+	unsigned int buflen;
+	unsigned int len;
+	unsigned int idx;
+	u32 state;
+	u8 bs;
+	u8 sn;
+	u8 ll_dl;
+	u8 sbuf[DEFAULT_MAX_PDU_SIZE];
+};
+
+struct isotp_sock {
+	struct sock sk;
+	int bound;
+	int ifindex;
+	struct net_device *dev;
+	netdevice_tracker dev_tracker;
+	canid_t txid;
+	canid_t rxid;
+	ktime_t tx_gap;
+	ktime_t lastrxcf_tstamp;
+	struct hrtimer rxtimer, txtimer, txfrtimer, echotimer;
+	struct can_isotp_options opt;
+	struct can_isotp_fc_options rxfc, txfc;
+	struct can_isotp_ll_options ll;
+	u32 frame_txtime;
+	u32 force_tx_stmin;
+	u32 force_rx_stmin;
+	u32 cfecho; /* consecutive frame echo tag */
+	u32 tx_gen; /* transfer generation, increased per new tx transfer */
+	u32 tx_result[ISOTP_TX_RESULT_SLOTS]; /* per-generation result slots */
+	struct tpcon rx, tx;
+	struct list_head notifier;
+	wait_queue_head_t wait;
+	spinlock_t rx_lock; /* protect single thread state machine */
+};
+
+static LIST_HEAD(isotp_notifier_list);
+static DEFINE_SPINLOCK(isotp_notifier_lock);
+static struct isotp_sock *isotp_busy_notifier;
+
+/* increase (24 bit) tx generation value */
+static u32 isotp_inc_tx_gen(u32 gen)
+{
+	return (gen + 1) & ISOTP_TX_RESULT_GEN_MASK;
+}
+
+/* store 8 bit error and 24 bit tx generation values in packed u32 element */
+static u32 isotp_pack_tx_result(u32 gen, int err)
+{
+	return gen | ((u32)err << ISOTP_TX_RESULT_GEN_BITS);
+}
+
+/* get the 24 bit tx generation value from the tx result */
+static u32 isotp_get_tx_gen(u32 gen_err)
+{
+	return gen_err & ISOTP_TX_RESULT_GEN_MASK;
+}
+
+/* get the 8 bit error value from the tx result */
+static u32 isotp_get_tx_err(u32 gen_err)
+{
+	return (gen_err >> ISOTP_TX_RESULT_GEN_BITS) & ISOTP_TX_RESULT_ERR_MASK;
+}
+
+/* store transfer result in per-generation%4 so->tx_result[] slot */
+static void isotp_set_tx_result(struct isotp_sock *so, u32 gen, int err)
+{
+	WRITE_ONCE(so->tx_result[gen % ISOTP_TX_RESULT_SLOTS],
+		   isotp_pack_tx_result(gen, err));
+}
+
+/* fetch the result recorded for 'gen', as a (negative) errno (0 for success) */
+static int isotp_get_tx_result(struct isotp_sock *so, u32 gen)
+{
+	u32 result = READ_ONCE(so->tx_result[gen % ISOTP_TX_RESULT_SLOTS]);
+
+	if (isotp_get_tx_gen(result) != gen) {
+		pr_notice_once("can-isotp: tx_result[] slot reused before read\n");
+
+		/* report failure rather than risk a false success */
+		return -ECOMM;
+	}
+
+	return -(isotp_get_tx_err(result));
+}
+
+/* true if done, shut down or superseded ('gen' is no longer the active
+ * transfer). Reads tx.state first (acquire) so tx_gen/tx_result reads
+ * below see at least what that state write published (common sequence).
+ */
+static bool isotp_tx_gen_done(struct isotp_sock *so, u32 gen)
+{
+	/* read tx.state first for the common sequence */
+	u32 state = smp_load_acquire(&so->tx.state);
+
+	return state == ISOTP_IDLE || state == ISOTP_SHUTDOWN ||
+	       READ_ONCE(so->tx_gen) != gen;
+}
+
+static inline struct isotp_sock *isotp_sk(const struct sock *sk)
+{
+	return (struct isotp_sock *)sk;
+}
+
+static u32 isotp_bc_flags(struct isotp_sock *so)
+{
+	return so->opt.flags & ISOTP_ALL_BC_FLAGS;
+}
+
+static bool isotp_register_rxid(struct isotp_sock *so)
+{
+	/* no broadcast modes => register rx_id for FC frame reception */
+	return (isotp_bc_flags(so) == 0);
+}
+
+static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     rxtimer);
+	struct sock *sk = &so->sk;
+
+	if (READ_ONCE(so->rx.state) == ISOTP_WAIT_DATA) {
+		/* we did not get new data frames in time */
+
+		/* report 'connection timed out' */
+		sk->sk_err = ETIMEDOUT;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+
+		/* reset rx state */
+		WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+	}
+
+	return HRTIMER_NORESTART;
+}
+
+static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
+{
+	struct net_device *dev;
+	struct sk_buff *nskb;
+	struct can_skb_ext *csx;
+	struct canfd_frame *ncf;
+	struct isotp_sock *so = isotp_sk(sk);
+	int can_send_ret;
+
+	nskb = alloc_skb(so->ll.mtu, gfp_any());
+	if (!nskb)
+		return 1;
+
+	csx = can_skb_ext_add(nskb);
+	if (!csx) {
+		kfree_skb(nskb);
+		return 1;
+	}
+
+	dev = dev_get_by_index(sock_net(sk), so->ifindex);
+	if (!dev) {
+		kfree_skb(nskb);
+		return 1;
+	}
+
+	csx->can_iif = dev->ifindex;
+	nskb->dev = dev;
+	can_skb_set_owner(nskb, sk);
+	ncf = (struct canfd_frame *)nskb->data;
+	skb_put_zero(nskb, so->ll.mtu);
+
+	/* create & send flow control reply */
+	ncf->can_id = so->txid;
+
+	if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+		memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
+		ncf->len = CAN_MAX_DLEN;
+	} else {
+		ncf->len = ae + FC_CONTENT_SZ;
+	}
+
+	ncf->data[ae] = N_PCI_FC | flowstatus;
+	ncf->data[ae + 1] = so->rxfc.bs;
+	ncf->data[ae + 2] = so->rxfc.stmin;
+
+	if (ae)
+		ncf->data[0] = so->opt.ext_address;
+
+	ncf->flags = so->ll.tx_flags;
+
+	can_send_ret = can_send(nskb, 1);
+	if (can_send_ret)
+		pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
+			       __func__, ERR_PTR(can_send_ret));
+
+	dev_put(dev);
+
+	/* reset blocksize counter */
+	so->rx.bs = 0;
+
+	/* reset last CF frame rx timestamp for rx stmin enforcement */
+	so->lastrxcf_tstamp = ktime_set(0, 0);
+
+	/* start rx timeout watchdog */
+	hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
+		      HRTIMER_MODE_REL_SOFT);
+	return 0;
+}
+
+static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
+	enum skb_drop_reason reason;
+
+	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
+
+	memset(addr, 0, sizeof(*addr));
+	addr->can_family = AF_CAN;
+	addr->can_ifindex = skb->dev->ifindex;
+
+	reason = sock_queue_rcv_skb_reason(sk, skb);
+	if (reason)
+		sk_skb_reason_drop(sk, skb, reason);
+}
+
+static u8 padlen(u8 datalen)
+{
+	static const u8 plen[] = {
+		8, 8, 8, 8, 8, 8, 8, 8, 8,	/* 0 - 8 */
+		12, 12, 12, 12,			/* 9 - 12 */
+		16, 16, 16, 16,			/* 13 - 16 */
+		20, 20, 20, 20,			/* 17 - 20 */
+		24, 24, 24, 24,			/* 21 - 24 */
+		32, 32, 32, 32, 32, 32, 32, 32,	/* 25 - 32 */
+		48, 48, 48, 48, 48, 48, 48, 48,	/* 33 - 40 */
+		48, 48, 48, 48, 48, 48, 48, 48	/* 41 - 48 */
+	};
+
+	if (datalen > 48)
+		return 64;
+
+	return plen[datalen];
+}
+
+/* check for length optimization and return 1/true when the check fails */
+static int check_optimized(struct canfd_frame *cf, int start_index)
+{
+	/* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
+	 * padding would start at this point. E.g. if the padding would
+	 * start at cf.data[7] cf->len has to be 7 to be optimal.
+	 * Note: The data[] index starts with zero.
+	 */
+	if (cf->len <= CAN_MAX_DLEN)
+		return (cf->len != start_index);
+
+	/* This relation is also valid in the non-linear DLC range, where
+	 * we need to take care of the minimal next possible CAN_DL.
+	 * The correct check would be (padlen(cf->len) != padlen(start_index)).
+	 * But as cf->len can only take discrete values from 12, .., 64 at this
+	 * point the padlen(cf->len) is always equal to cf->len.
+	 */
+	return (cf->len != padlen(start_index));
+}
+
+/* check padding and return 1/true when the check fails */
+static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
+		     int start_index, u8 content)
+{
+	int i;
+
+	/* no RX_PADDING value => check length of optimized frame length */
+	if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
+		if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
+			return check_optimized(cf, start_index);
+
+		/* no valid test against empty value => ignore frame */
+		return 1;
+	}
+
+	/* check datalength of correctly padded CAN frame */
+	if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
+	    cf->len != padlen(cf->len))
+		return 1;
+
+	/* check padding content */
+	if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
+		for (i = start_index; i < cf->len; i++)
+			if (cf->data[i] != content)
+				return 1;
+	}
+	return 0;
+}
+
+static void isotp_send_cframe(struct isotp_sock *so);
+
+static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
+{
+	struct sock *sk = &so->sk;
+	int tx_err = EBADMSG; /* default for unknown FC status */
+
+	if (READ_ONCE(so->tx.state) != ISOTP_WAIT_FC &&
+	    READ_ONCE(so->tx.state) != ISOTP_WAIT_FIRST_FC)
+		return 0;
+
+	hrtimer_cancel(&so->txtimer);
+
+	/* isotp_tx_timeout() may have given up on this job while
+	 * hrtimer_cancel() above waited for it to finish => recheck
+	 */
+	if (READ_ONCE(so->tx.state) != ISOTP_WAIT_FC &&
+	    READ_ONCE(so->tx.state) != ISOTP_WAIT_FIRST_FC)
+		return 1;
+
+	if ((cf->len < ae + FC_CONTENT_SZ) ||
+	    ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+	     check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
+		/* malformed PDU - report 'not a data message' */
+		sk->sk_err = EBADMSG;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+
+		isotp_set_tx_result(so, so->tx_gen, EBADMSG);
+		/* set to IDLE after publishing tx_result */
+		smp_store_release(&so->tx.state, ISOTP_IDLE);
+		wake_up_interruptible(&so->wait);
+		return 1;
+	}
+
+	/* get static/dynamic communication params from first/every FC frame */
+	if (READ_ONCE(so->tx.state) == ISOTP_WAIT_FIRST_FC ||
+	    so->opt.flags & CAN_ISOTP_DYN_FC_PARMS) {
+		so->txfc.bs = cf->data[ae + 1];
+		so->txfc.stmin = cf->data[ae + 2];
+
+		/* fix wrong STmin values according spec */
+		if (so->txfc.stmin > 0x7F &&
+		    (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
+			so->txfc.stmin = 0x7F;
+
+		so->tx_gap = ktime_set(0, 0);
+		/* add transmission time for CAN frame N_As */
+		so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
+		/* add waiting time for consecutive frames N_Cs */
+		if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  so->force_tx_stmin);
+		else if (so->txfc.stmin < 0x80)
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  so->txfc.stmin * 1000000);
+		else
+			so->tx_gap = ktime_add_ns(so->tx_gap,
+						  (so->txfc.stmin - 0xF0)
+						  * 100000);
+		WRITE_ONCE(so->tx.state, ISOTP_WAIT_FC);
+	}
+
+	switch (cf->data[ae] & 0x0F) {
+	case ISOTP_FC_CTS:
+		so->tx.bs = 0;
+		WRITE_ONCE(so->tx.state, ISOTP_SENDING);
+		/* send CF frame and enable echo timeout handling */
+		hrtimer_start(&so->echotimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		isotp_send_cframe(so);
+		break;
+
+	case ISOTP_FC_WT:
+		/* start timer to wait for next FC frame */
+		hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		break;
+
+	case ISOTP_FC_OVFLW:
+		/* overflow on receiver side - report 'message too long' */
+		tx_err = EMSGSIZE;
+		fallthrough;
+
+	default:
+		/* reserved/unknown flow status (tx_err defaults to EBADMSG) */
+
+		sk->sk_err = tx_err;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+
+		isotp_set_tx_result(so, so->tx_gen, tx_err);
+		/* set to IDLE after publishing tx_result */
+		smp_store_release(&so->tx.state, ISOTP_IDLE);
+		wake_up_interruptible(&so->wait);
+	}
+	return 0;
+}
+
+static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
+			struct sk_buff *skb, int len)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *nskb;
+
+	hrtimer_cancel(&so->rxtimer);
+	WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+
+	if (!len || len > cf->len - pcilen)
+		return 1;
+
+	if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+	    check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
+		/* malformed PDU - report 'not a data message' */
+		sk->sk_err = EBADMSG;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+		return 1;
+	}
+
+	nskb = alloc_skb(len, gfp_any());
+	if (!nskb)
+		return 1;
+
+	memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
+
+	nskb->tstamp = skb->tstamp;
+	nskb->dev = skb->dev;
+	isotp_rcv_skb(nskb, sk);
+	return 0;
+}
+
+static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	int i;
+	int off;
+	int ff_pci_sz;
+
+	hrtimer_cancel(&so->rxtimer);
+	WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+
+	/* get the used sender LL_DL from the (first) CAN frame data length */
+	so->rx.ll_dl = padlen(cf->len);
+
+	/* the first frame has to use the entire frame up to LL_DL length */
+	if (cf->len != so->rx.ll_dl)
+		return 1;
+
+	/* get the FF_DL */
+	so->rx.len = (cf->data[ae] & 0x0F) << 8;
+	so->rx.len += cf->data[ae + 1];
+
+	/* Check for FF_DL escape sequence supporting 32 bit PDU length */
+	if (so->rx.len) {
+		ff_pci_sz = FF_PCI_SZ12;
+	} else {
+		/* FF_DL = 0 => get real length from next 4 bytes */
+		so->rx.len = cf->data[ae + 2] << 24;
+		so->rx.len += cf->data[ae + 3] << 16;
+		so->rx.len += cf->data[ae + 4] << 8;
+		so->rx.len += cf->data[ae + 5];
+		ff_pci_sz = FF_PCI_SZ32;
+	}
+
+	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+	off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
+
+	if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
+		return 1;
+
+	/* PDU size > default => try max_pdu_size */
+	if (so->rx.len > so->rx.buflen && so->rx.buflen < max_pdu_size) {
+		u8 *newbuf = kmalloc(max_pdu_size, GFP_ATOMIC);
+
+		if (newbuf) {
+			so->rx.buf = newbuf;
+			so->rx.buflen = max_pdu_size;
+		}
+	}
+
+	if (so->rx.len > so->rx.buflen) {
+		/* send FC frame with overflow status */
+		isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
+		return 1;
+	}
+
+	/* copy the first received data bytes */
+	so->rx.idx = 0;
+	for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
+		so->rx.buf[so->rx.idx++] = cf->data[i];
+
+	/* initial setup for this pdu reception */
+	so->rx.sn = 1;
+	WRITE_ONCE(so->rx.state, ISOTP_WAIT_DATA);
+
+	/* no creation of flow control frames */
+	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+		return 0;
+
+	/* send our first FC frame */
+	isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+	return 0;
+}
+
+static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
+			struct sk_buff *skb)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *nskb;
+	int i;
+
+	if (READ_ONCE(so->rx.state) != ISOTP_WAIT_DATA)
+		return 0;
+
+	/* drop if timestamp gap is less than force_rx_stmin nano secs */
+	if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
+		if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
+		    so->force_rx_stmin)
+			return 0;
+
+		so->lastrxcf_tstamp = skb->tstamp;
+	}
+
+	hrtimer_cancel(&so->rxtimer);
+
+	/* isotp_rx_timer_handler() may have raced us for so->rx.state
+	 * while hrtimer_cancel() above waited for it to finish => recheck
+	 */
+	if (READ_ONCE(so->rx.state) != ISOTP_WAIT_DATA)
+		return 1;
+
+	/* CFs are never longer than the FF */
+	if (cf->len > so->rx.ll_dl)
+		return 1;
+
+	/* CFs have usually the LL_DL length */
+	if (cf->len < so->rx.ll_dl) {
+		/* this is only allowed for the last CF */
+		if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
+			return 1;
+	}
+
+	if ((cf->data[ae] & 0x0F) != so->rx.sn) {
+		/* wrong sn detected - report 'illegal byte sequence' */
+		sk->sk_err = EILSEQ;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+
+		/* reset rx state */
+		WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+		return 1;
+	}
+	so->rx.sn++;
+	so->rx.sn %= 16;
+
+	for (i = ae + N_PCI_SZ; i < cf->len; i++) {
+		so->rx.buf[so->rx.idx++] = cf->data[i];
+		if (so->rx.idx >= so->rx.len)
+			break;
+	}
+
+	if (so->rx.idx >= so->rx.len) {
+		/* we are done */
+		WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+
+		if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+		    check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
+			/* malformed PDU - report 'not a data message' */
+			sk->sk_err = EBADMSG;
+			if (!sock_flag(sk, SOCK_DEAD))
+				sk_error_report(sk);
+			return 1;
+		}
+
+		nskb = alloc_skb(so->rx.len, gfp_any());
+		if (!nskb)
+			return 1;
+
+		memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
+		       so->rx.len);
+
+		nskb->tstamp = skb->tstamp;
+		nskb->dev = skb->dev;
+		isotp_rcv_skb(nskb, sk);
+		return 0;
+	}
+
+	/* perform blocksize handling, if enabled */
+	if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
+		/* start rx timeout watchdog */
+		hrtimer_start(&so->rxtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		return 0;
+	}
+
+	/* no creation of flow control frames */
+	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+		return 0;
+
+	/* we reached the specified blocksize so->rxfc.bs */
+	isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+	return 0;
+}
+
+static void isotp_rcv(struct sk_buff *skb, void *data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct canfd_frame *cf;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+	u8 n_pci_type, sf_dl;
+
+	/* Strictly receive only frames with the configured MTU size
+	 * => clear separation of CAN2.0 / CAN FD transport channels
+	 */
+	if (skb->len != so->ll.mtu)
+		return;
+
+	cf = (struct canfd_frame *)skb->data;
+
+	/* if enabled: check reception of my configured extended address */
+	if (ae && cf->data[0] != so->opt.rx_ext_address)
+		return;
+
+	n_pci_type = cf->data[ae] & 0xF0;
+
+	/* Make sure the state changes and data structures stay consistent at
+	 * CAN frame reception time. This locking is not needed in real world
+	 * use cases but the inconsistency can be triggered with syzkaller.
+	 */
+	spin_lock(&so->rx_lock);
+
+	if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
+		/* check rx/tx path half duplex expectations */
+		if ((READ_ONCE(so->tx.state) != ISOTP_IDLE &&
+		     n_pci_type != N_PCI_FC) ||
+		    (READ_ONCE(so->rx.state) != ISOTP_IDLE &&
+		     n_pci_type == N_PCI_FC))
+			goto out_unlock;
+	}
+
+	switch (n_pci_type) {
+	case N_PCI_FC:
+		/* tx path: flow control frame containing the FC parameters */
+		isotp_rcv_fc(so, cf, ae);
+		break;
+
+	case N_PCI_SF:
+		/* rx path: single frame
+		 *
+		 * As we do not have a rx.ll_dl configuration, we can only test
+		 * if the CAN frames payload length matches the LL_DL == 8
+		 * requirements - no matter if it's CAN 2.0 or CAN FD
+		 */
+
+		/* get the SF_DL from the N_PCI byte */
+		sf_dl = cf->data[ae] & 0x0F;
+
+		if (cf->len <= CAN_MAX_DLEN) {
+			isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
+		} else {
+			if (can_is_canfd_skb(skb)) {
+				/* We have a CAN FD frame and CAN_DL is greater than 8:
+				 * Only frames with the SF_DL == 0 ESC value are valid.
+				 *
+				 * If so take care of the increased SF PCI size
+				 * (SF_PCI_SZ8) to point to the message content behind
+				 * the extended SF PCI info and get the real SF_DL
+				 * length value from the formerly first data byte.
+				 */
+				if (sf_dl == 0)
+					isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
+						     cf->data[SF_PCI_SZ4 + ae]);
+			}
+		}
+		break;
+
+	case N_PCI_FF:
+		/* rx path: first frame */
+		isotp_rcv_ff(sk, cf, ae);
+		break;
+
+	case N_PCI_CF:
+		/* rx path: consecutive frame */
+		isotp_rcv_cf(sk, cf, ae, skb);
+		break;
+	}
+
+out_unlock:
+	spin_unlock(&so->rx_lock);
+}
+
+static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
+				 int ae, int off)
+{
+	int pcilen = N_PCI_SZ + ae + off;
+	int space = so->tx.ll_dl - pcilen;
+	int num = min_t(int, so->tx.len - so->tx.idx, space);
+	int i;
+
+	cf->can_id = so->txid;
+	cf->len = num + pcilen;
+
+	if (num < space) {
+		if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+			/* user requested padding */
+			cf->len = padlen(cf->len);
+			memset(cf->data, so->opt.txpad_content, cf->len);
+		} else if (cf->len > CAN_MAX_DLEN) {
+			/* mandatory padding for CAN FD frames */
+			cf->len = padlen(cf->len);
+			memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
+			       cf->len);
+		}
+	}
+
+	for (i = 0; i < num; i++)
+		cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
+
+	if (ae)
+		cf->data[0] = so->opt.ext_address;
+}
+
+static void isotp_send_cframe(struct isotp_sock *so)
+{
+	struct sock *sk = &so->sk;
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct net_device *dev;
+	struct canfd_frame *cf;
+	int can_send_ret;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+	u32 old_cfecho;
+
+	dev = dev_get_by_index(sock_net(sk), so->ifindex);
+	if (!dev)
+		return;
+
+	skb = alloc_skb(so->ll.mtu, GFP_ATOMIC);
+	if (!skb) {
+		dev_put(dev);
+		return;
+	}
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		netdev_put(dev, NULL);
+		return;
+	}
+
+	csx->can_iif = dev->ifindex;
+
+	/* set uid in tx skb to identify CF echo frames */
+	can_set_skb_uid(skb);
+
+	cf = (struct canfd_frame *)skb->data;
+	skb_put_zero(skb, so->ll.mtu);
+
+	/* create consecutive frame */
+	isotp_fill_dataframe(cf, so, ae, 0);
+
+	/* place consecutive frame N_PCI in appropriate index */
+	cf->data[ae] = N_PCI_CF | so->tx.sn++;
+	so->tx.sn %= 16;
+	so->tx.bs++;
+
+	cf->flags = so->ll.tx_flags;
+
+	skb->dev = dev;
+	can_skb_set_owner(skb, sk);
+
+	/* zero'ed by init/isotp_rcv_echo(); reached lock-free via
+	 * isotp_txfr_timer_handler() too, so use READ_ONCE()/WRITE_ONCE()
+	 */
+	old_cfecho = READ_ONCE(so->cfecho);
+	if (old_cfecho)
+		pr_notice_once("can-isotp: cfecho is %08X != 0\n", old_cfecho);
+
+	/* set consecutive frame echo tag */
+	WRITE_ONCE(so->cfecho, skb->hash);
+
+	/* send frame with local echo enabled */
+	can_send_ret = can_send(skb, 1);
+	if (can_send_ret) {
+		pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
+			       __func__, ERR_PTR(can_send_ret));
+		if (can_send_ret == -ENOBUFS)
+			pr_notice_once("can-isotp: tx queue is full\n");
+	}
+	dev_put(dev);
+}
+
+static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
+				int ae)
+{
+	int i;
+	int ff_pci_sz;
+
+	cf->can_id = so->txid;
+	cf->len = so->tx.ll_dl;
+	if (ae)
+		cf->data[0] = so->opt.ext_address;
+
+	/* create N_PCI bytes with 12/32 bit FF_DL data length */
+	if (so->tx.len > MAX_12BIT_PDU_SIZE) {
+		/* use 32 bit FF_DL notation */
+		cf->data[ae] = N_PCI_FF;
+		cf->data[ae + 1] = 0;
+		cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
+		cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
+		cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
+		cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
+		ff_pci_sz = FF_PCI_SZ32;
+	} else {
+		/* use 12 bit FF_DL notation */
+		cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
+		cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
+		ff_pci_sz = FF_PCI_SZ12;
+	}
+
+	/* add first data bytes depending on ae */
+	for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
+		cf->data[i] = so->tx.buf[so->tx.idx++];
+
+	so->tx.sn = 1;
+}
+
+static void isotp_rcv_echo(struct sk_buff *skb, void *data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct isotp_sock *so = isotp_sk(sk);
+
+	/* only handle my own local echo CF/SF skb's (no FF!) */
+	if (skb->sk != sk)
+		return;
+
+	/* unlike isotp_rcv_fc()/isotp_rcv_cf(), not already under so->rx_lock
+	 * (no isotp_rcv() caller here), so take it ourselves
+	 */
+	spin_lock(&so->rx_lock);
+
+	/* so->cfecho may since belong to a new transfer; recheck under lock */
+	if (READ_ONCE(so->cfecho) != skb->hash)
+		goto out_unlock;
+
+	/* cancel local echo timeout */
+	hrtimer_cancel(&so->echotimer);
+
+	/* local echo skb with consecutive frame has been consumed */
+	WRITE_ONCE(so->cfecho, 0);
+
+	/* claiming a transfer also takes so->rx_lock, so a plain recheck
+	 * is enough: so->tx.state can't have flipped to ISOTP_SENDING for
+	 * a new claim while we're still in here
+	 */
+	if (READ_ONCE(so->tx.state) != ISOTP_SENDING)
+		goto out_unlock;
+
+	if (so->tx.idx >= so->tx.len) {
+		/* we are done */
+
+		isotp_set_tx_result(so, so->tx_gen, 0);
+		/* set to IDLE after publishing tx_result */
+		smp_store_release(&so->tx.state, ISOTP_IDLE);
+		wake_up_interruptible(&so->wait);
+		goto out_unlock;
+	}
+
+	if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
+		/* stop and wait for FC with timeout */
+		WRITE_ONCE(so->tx.state, ISOTP_WAIT_FC);
+		hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		goto out_unlock;
+	}
+
+	/* no gap between data frames needed => use burst mode */
+	if (!so->tx_gap) {
+		/* enable echo timeout handling */
+		hrtimer_start(&so->echotimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		isotp_send_cframe(so);
+		goto out_unlock;
+	}
+
+	/* start timer to send next consecutive frame with correct delay */
+	hrtimer_start(&so->txfrtimer, so->tx_gap, HRTIMER_MODE_REL_SOFT);
+
+out_unlock:
+	spin_unlock(&so->rx_lock);
+}
+
+/* isotp_tx_timeout: we did not get any flow control or echo frame in time
+ *
+ * Shared by so->txtimer's and so->echotimer's callbacks. Both timers get
+ * cancelled under so->rx_lock elsewhere, so this must stay lock-free.
+ *
+ * tx.state is acquired before tx_gen. Common sequence in isotp_tx_gen_done().
+ * cmpxchg() only orders itself, not the two preceding loads.
+ */
+static enum hrtimer_restart isotp_tx_timeout(struct isotp_sock *so)
+{
+	struct sock *sk = &so->sk;
+	/* read tx.state first for the common sequence */
+	u32 old_state = smp_load_acquire(&so->tx.state);
+	u32 gen = READ_ONCE(so->tx_gen);
+
+	/* don't handle timeouts in IDLE or SHUTDOWN state */
+	if (old_state == ISOTP_IDLE || old_state == ISOTP_SHUTDOWN)
+		return HRTIMER_NORESTART;
+
+	/* only claim the timeout if the state is still unchanged */
+	if (cmpxchg(&so->tx.state, old_state, ISOTP_IDLE) != old_state)
+		return HRTIMER_NORESTART;
+
+	/* detected timeout: report 'communication error on send' */
+
+	/* a stale read of this slot by a waiter still falls back to ECOMM */
+	isotp_set_tx_result(so, gen, ECOMM);
+
+	sk->sk_err = ECOMM;
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk_error_report(sk);
+
+	wake_up_interruptible(&so->wait);
+
+	return HRTIMER_NORESTART;
+}
+
+/* so->txtimer: fires when a Flow Control frame does not arrive in time */
+static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     txtimer);
+
+	return isotp_tx_timeout(so);
+}
+
+/* so->echotimer: fires when a sent CF/SF's local echo does not arrive */
+static enum hrtimer_restart isotp_echo_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     echotimer);
+
+	return isotp_tx_timeout(so);
+}
+
+static enum hrtimer_restart isotp_txfr_timer_handler(struct hrtimer *hrtimer)
+{
+	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+					     txfrtimer);
+
+	/* start echo timeout handling and cover below protocol error */
+	hrtimer_start(&so->echotimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
+		      HRTIMER_MODE_REL_SOFT);
+
+	/* cfecho should be consumed by isotp_rcv_echo() here */
+	if (READ_ONCE(so->tx.state) == ISOTP_SENDING && !READ_ONCE(so->cfecho))
+		isotp_send_cframe(so);
+
+	return HRTIMER_NORESTART;
+}
+
+static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct net_device *dev;
+	struct canfd_frame *cf;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+	int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
+	s64 hrtimer_sec = ISOTP_ECHO_TIMEOUT;
+	struct hrtimer *tx_hrt = &so->echotimer;
+	u32 new_state = ISOTP_SENDING;
+	u32 my_gen;
+	u32 old_cfecho;
+	int off;
+	int err;
+
+	if (!so->bound || READ_ONCE(so->tx.state) == ISOTP_SHUTDOWN)
+		return -EADDRNOTAVAIL;
+
+	/* claim the socket under so->rx_lock: this serializes the claim
+	 * with the RX path and with sendmsg()'s own error paths below, so
+	 * none of them can ever see a transfer mid-claim
+	 */
+	for (;;) {
+		spin_lock_bh(&so->rx_lock);
+		if (READ_ONCE(so->tx.state) == ISOTP_IDLE)
+			break;
+		spin_unlock_bh(&so->rx_lock);
+
+		/* we do not support multiple buffers - for now */
+		if (msg->msg_flags & MSG_DONTWAIT)
+			return -EAGAIN;
+
+		if (READ_ONCE(so->tx.state) == ISOTP_SHUTDOWN)
+			return -EADDRNOTAVAIL;
+
+		/* wait for complete transmission of current pdu */
+		err = wait_event_interruptible(so->wait,
+					       READ_ONCE(so->tx.state) == ISOTP_IDLE ||
+					       READ_ONCE(so->tx.state) == ISOTP_SHUTDOWN);
+		if (err)
+			return err;
+	}
+
+	/* txfrtimer's callback re-arms echotimer lock-free: drain it first */
+	hrtimer_cancel(&so->txfrtimer);
+	hrtimer_cancel(&so->txtimer);
+	hrtimer_cancel(&so->echotimer);
+
+	/* new transfer: increment so->tx_gen and set tx.state after barrier */
+	my_gen = isotp_inc_tx_gen(READ_ONCE(so->tx_gen));
+	isotp_set_tx_result(so, my_gen, ECOMM); /* prevent stale slot matching */
+	WRITE_ONCE(so->tx_gen, my_gen);
+	smp_wmb(); /* see smp_load_acquire() in isotp_tx_[timeout|gen_done] */
+	WRITE_ONCE(so->tx.state, ISOTP_SENDING);
+	WRITE_ONCE(so->cfecho, 0);
+	spin_unlock_bh(&so->rx_lock);
+
+	/* so->bound is only checked once above - a wakeup may have
+	 * unbound/rebound the socket meanwhile => recheck
+	 */
+	if (!so->bound) {
+		err = -EADDRNOTAVAIL;
+		goto err_out_drop;
+	}
+
+	/* PDU size > default => try max_pdu_size */
+	if (size > so->tx.buflen && so->tx.buflen < max_pdu_size) {
+		u8 *newbuf = kmalloc(max_pdu_size, GFP_KERNEL);
+
+		if (newbuf) {
+			so->tx.buf = newbuf;
+			so->tx.buflen = max_pdu_size;
+		}
+	}
+
+	if (!size || size > so->tx.buflen) {
+		err = -EINVAL;
+		goto err_out_drop;
+	}
+
+	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+	off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
+
+	/* does the given data fit into a single frame for SF_BROADCAST? */
+	if ((isotp_bc_flags(so) == CAN_ISOTP_SF_BROADCAST) &&
+	    (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
+		err = -EINVAL;
+		goto err_out_drop;
+	}
+
+	err = memcpy_from_msg(so->tx.buf, msg, size);
+	if (err < 0)
+		goto err_out_drop;
+
+	dev = dev_get_by_index(sock_net(sk), so->ifindex);
+	if (!dev) {
+		err = -ENXIO;
+		goto err_out_drop;
+	}
+
+	skb = sock_alloc_send_skb(sk, so->ll.mtu, msg->msg_flags & MSG_DONTWAIT,
+				  &err);
+	if (!skb) {
+		dev_put(dev);
+		goto err_out_drop;
+	}
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		netdev_put(dev, NULL);
+		err = -ENOMEM;
+		goto err_out_drop;
+	}
+
+	csx->can_iif = dev->ifindex;
+
+	/* set uid in tx skb to identify CF echo frames */
+	can_set_skb_uid(skb);
+
+	so->tx.len = size;
+	so->tx.idx = 0;
+
+	cf = (struct canfd_frame *)skb->data;
+	skb_put_zero(skb, so->ll.mtu);
+
+	/* cfecho should have been zero'ed by init / former isotp_rcv_echo() */
+	old_cfecho = READ_ONCE(so->cfecho);
+	if (old_cfecho)
+		pr_notice_once("can-isotp: uninit cfecho %08X\n", old_cfecho);
+
+	/* check for single frame transmission depending on TX_DL */
+	if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
+		/* The message size generally fits into a SingleFrame - good.
+		 *
+		 * SF_DL ESC offset optimization:
+		 *
+		 * When TX_DL is greater 8 but the message would still fit
+		 * into a 8 byte CAN frame, we can omit the offset.
+		 * This prevents a protocol caused length extension from
+		 * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
+		 */
+		if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
+			off = 0;
+
+		isotp_fill_dataframe(cf, so, ae, off);
+
+		/* place single frame N_PCI w/o length in appropriate index */
+		cf->data[ae] = N_PCI_SF;
+
+		/* place SF_DL size value depending on the SF_DL ESC offset */
+		if (off)
+			cf->data[SF_PCI_SZ4 + ae] = size;
+		else
+			cf->data[ae] |= size;
+
+		/* set CF echo tag for isotp_rcv_echo() (SF-mode) */
+		WRITE_ONCE(so->cfecho, skb->hash);
+	} else {
+		/* send first frame */
+
+		isotp_create_fframe(cf, so, ae);
+
+		if (isotp_bc_flags(so) == CAN_ISOTP_CF_BROADCAST) {
+			/* set timer for FC-less operation (STmin = 0) */
+			if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
+				so->tx_gap = ktime_set(0, so->force_tx_stmin);
+			else
+				so->tx_gap = ktime_set(0, so->frame_txtime);
+
+			/* disable wait for FCs due to activated block size */
+			so->txfc.bs = 0;
+
+			/* set CF echo tag for isotp_rcv_echo() (CF-mode) */
+			WRITE_ONCE(so->cfecho, skb->hash);
+		} else {
+			/* standard flow control check */
+			new_state = ISOTP_WAIT_FIRST_FC;
+
+			/* start timeout for FC */
+			hrtimer_sec = ISOTP_FC_TIMEOUT;
+			tx_hrt = &so->txtimer;
+
+			/* no CF echo tag for isotp_rcv_echo() (FF-mode) */
+			WRITE_ONCE(so->cfecho, 0);
+		}
+	}
+
+	spin_lock_bh(&so->rx_lock);
+	if (READ_ONCE(so->tx.state) == ISOTP_SHUTDOWN) {
+		/* isotp_release() has since taken over and already drained
+		 * our timers - don't send into a socket that's going away
+		 */
+		spin_unlock_bh(&so->rx_lock);
+		kfree_skb(skb);
+		dev_put(dev);
+		wake_up_interruptible(&so->wait);
+		return -EADDRNOTAVAIL;
+	}
+	/* WAIT_FIRST_FC for standard FF, else stays ISOTP_SENDING */
+	WRITE_ONCE(so->tx.state, new_state);
+	hrtimer_start(tx_hrt, ktime_set(hrtimer_sec, 0),
+		      HRTIMER_MODE_REL_SOFT);
+	spin_unlock_bh(&so->rx_lock);
+
+	/* send the first or only CAN frame */
+	cf->flags = so->ll.tx_flags;
+
+	skb->dev = dev;
+	skb->sk = sk;
+	err = can_send(skb, 1);
+	dev_put(dev);
+	if (err) {
+		pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
+			       __func__, ERR_PTR(err));
+
+		spin_lock_bh(&so->rx_lock);
+
+		/* new transfer already claimed by a concurrent completion,
+		 * timeout or sendmsg() while we were stuck in can_send()?
+		 */
+		if (READ_ONCE(so->tx_gen) != my_gen) {
+			/* don't touch timers and state of the new transfer */
+			spin_unlock_bh(&so->rx_lock);
+			return err;
+		}
+
+		/* no transmission -> no timeout monitoring */
+		hrtimer_cancel(tx_hrt);
+		goto err_out_drop_locked;
+	}
+
+	if (wait_tx_done) {
+		/* wake up for:
+		 * - concurrent sendmsg() claiming a new transfer
+		 * - complete transmission of current PDU
+		 * - shutdown state change in isotp_release()
+		 * isotp_tx_gen_done() uses common tx.state/tx_gen read sequence
+		 */
+		err = wait_event_interruptible(so->wait,
+					       isotp_tx_gen_done(so, my_gen));
+		if (err)
+			goto err_event_drop;
+
+		/* still our claim, but isotp_release() force-shut it down */
+		if (smp_load_acquire(&so->tx.state) == ISOTP_SHUTDOWN &&
+		    READ_ONCE(so->tx_gen) == my_gen) {
+			err = -EADDRNOTAVAIL;
+			goto err_event_drop;
+		}
+
+		/* own completion, or tx_gen moved on - either way this is
+		 * what isotp_get_tx_result() recorded for my_gen
+		 */
+		err = isotp_get_tx_result(so, my_gen);
+
+		/* drain to avoid stale error for a later poll()/SO_ERROR */
+		sock_error(sk);
+
+		return err ? err : size;
+	}
+
+	return size;
+
+err_out_drop:
+	/* claimed but nothing sent yet - no timer to cancel */
+	spin_lock_bh(&so->rx_lock);
+	goto err_out_drop_locked;
+err_event_drop:
+	/* interrupted or shut down while waiting on our own transfer */
+	spin_lock_bh(&so->rx_lock);
+
+	/* new transfer already started by concurrent sendmsg()? */
+	if (READ_ONCE(so->tx_gen) != my_gen) {
+		/* don't touch timers and states of the new transfer */
+		spin_unlock_bh(&so->rx_lock);
+		return err;
+	}
+
+	hrtimer_cancel(&so->txfrtimer);
+	hrtimer_cancel(&so->txtimer);
+	hrtimer_cancel(&so->echotimer);
+err_out_drop_locked:
+	/* release the claim; so->rx_lock still held from above */
+	WRITE_ONCE(so->cfecho, 0);
+
+	/* only claim to IDLE if isotp_release() has not taken over */
+	if (READ_ONCE(so->tx.state) != ISOTP_SHUTDOWN)
+		WRITE_ONCE(so->tx.state, ISOTP_IDLE);
+	spin_unlock_bh(&so->rx_lock);
+	wake_up_interruptible(&so->wait);
+
+	return err;
+}
+
+static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+			 int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	struct isotp_sock *so = isotp_sk(sk);
+	int ret = 0;
+
+	if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	if (!so->bound)
+		return -EADDRNOTAVAIL;
+
+	skb = skb_recv_datagram(sk, flags, &ret);
+	if (!skb)
+		return ret;
+
+	if (size < skb->len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		size = skb->len;
+
+	ret = memcpy_to_msg(msg, skb->data, size);
+	if (ret < 0)
+		goto out_err;
+
+	sock_recv_cmsgs(msg, sk, skb);
+
+	if (msg->msg_name) {
+		__sockaddr_check_size(ISOTP_MIN_NAMELEN);
+		msg->msg_namelen = ISOTP_MIN_NAMELEN;
+		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+	}
+
+	/* set length of return value */
+	ret = (flags & MSG_TRUNC) ? skb->len : size;
+
+out_err:
+	skb_free_datagram(sk, skb);
+
+	return ret;
+}
+
+static int isotp_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so;
+	struct net *net;
+
+	if (!sk)
+		return 0;
+
+	so = isotp_sk(sk);
+	net = sock_net(sk);
+
+	/* best-effort: wait for a running pdu to finish, but don't block on
+	 * it forever - give up after the first signal
+	 */
+	while (READ_ONCE(so->tx.state) != ISOTP_IDLE &&
+	       wait_event_interruptible(so->wait,
+					READ_ONCE(so->tx.state) == ISOTP_IDLE) == 0)
+		;
+
+	/* claim the socket under so->rx_lock like sendmsg() does, so its
+	 * claim can't race the forced ISOTP_SHUTDOWN below; force it
+	 * unconditionally, even when a signal cut the wait above short
+	 */
+	spin_lock_bh(&so->rx_lock);
+	WRITE_ONCE(so->tx.state, ISOTP_SHUTDOWN);
+	spin_unlock_bh(&so->rx_lock);
+	WRITE_ONCE(so->rx.state, ISOTP_IDLE);
+
+	/* forced SHUTDOWN may have skipped IDLE (gave up on a signal) */
+	wake_up_interruptible(&so->wait);
+
+	spin_lock(&isotp_notifier_lock);
+	while (isotp_busy_notifier == so) {
+		spin_unlock(&isotp_notifier_lock);
+		schedule_timeout_uninterruptible(1);
+		spin_lock(&isotp_notifier_lock);
+	}
+	list_del(&so->notifier);
+	spin_unlock(&isotp_notifier_lock);
+
+	rtnl_lock();
+	lock_sock(sk);
+
+	/* remove current filters & unregister
+	 * tracked reference so->dev is taken at bind() time with rtnl_lock
+	 */
+	if (so->bound && so->dev) {
+		if (isotp_register_rxid(so))
+			can_rx_unregister(net, so->dev, so->rxid,
+					  SINGLE_MASK(so->rxid),
+					  isotp_rcv, sk);
+
+		can_rx_unregister(net, so->dev, so->txid,
+				  SINGLE_MASK(so->txid),
+				  isotp_rcv_echo, sk);
+		netdev_put(so->dev, &so->dev_tracker);
+	}
+
+	so->ifindex = 0;
+	so->bound = 0;
+	so->dev = NULL;
+
+	rtnl_unlock();
+
+	/* Always wait for a grace period before touching the timers below.
+	 * A concurrent NETDEV_UNREGISTER may have already unregistered our
+	 * filters and cleared so->bound in isotp_notify() without waiting
+	 * for in-flight isotp_rcv() callers to finish, so this call must not
+	 * be skipped just because so->bound is already 0 here.
+	 */
+	synchronize_rcu();
+
+	hrtimer_cancel(&so->txfrtimer);
+	hrtimer_cancel(&so->txtimer);
+	hrtimer_cancel(&so->echotimer);
+	hrtimer_cancel(&so->rxtimer);
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	sock_prot_inuse_add(net, sk->sk_prot, -1);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int isotp_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct net *net = sock_net(sk);
+	int ifindex;
+	struct net_device *dev;
+	canid_t tx_id = addr->can_addr.tp.tx_id;
+	canid_t rx_id = addr->can_addr.tp.rx_id;
+	int err = 0;
+	int notify_enetdown = 0;
+
+	if (len < ISOTP_MIN_NAMELEN)
+		return -EINVAL;
+
+	if (addr->can_family != AF_CAN)
+		return -EINVAL;
+
+	/* sanitize tx CAN identifier */
+	if (tx_id & CAN_EFF_FLAG)
+		tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+	else
+		tx_id &= CAN_SFF_MASK;
+
+	/* give feedback on wrong CAN-ID value */
+	if (tx_id != addr->can_addr.tp.tx_id)
+		return -EINVAL;
+
+	/* sanitize rx CAN identifier (if needed) */
+	if (isotp_register_rxid(so)) {
+		if (rx_id & CAN_EFF_FLAG)
+			rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+		else
+			rx_id &= CAN_SFF_MASK;
+
+		/* give feedback on wrong CAN-ID value */
+		if (rx_id != addr->can_addr.tp.rx_id)
+			return -EINVAL;
+	}
+
+	if (!addr->can_ifindex)
+		return -ENODEV;
+
+	rtnl_lock();
+	lock_sock(sk);
+
+	if (so->bound) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* A transmission or reception that outlived a previous binding
+	 * (unbound by NETDEV_UNREGISTER) may still be draining; the FC/echo
+	 * and RX watchdog timers bound how long this takes. Checked together
+	 * with so->bound in the same lock_sock() section above, so there is
+	 * no window in which a concurrent isotp_notify() could be missed.
+	 */
+	if (READ_ONCE(so->tx.state) != ISOTP_IDLE ||
+	    READ_ONCE(so->rx.state) != ISOTP_IDLE) {
+		err = -EAGAIN;
+		goto out;
+	}
+
+	/* ensure different CAN IDs when the rx_id is to be registered */
+	if (isotp_register_rxid(so) && rx_id == tx_id) {
+		err = -EADDRNOTAVAIL;
+		goto out;
+	}
+
+	dev = dev_get_by_index(net, addr->can_ifindex);
+	if (!dev) {
+		err = -ENODEV;
+		goto out;
+	}
+	if (dev->type != ARPHRD_CAN) {
+		err = -ENODEV;
+		goto out_put_dev;
+	}
+	if (READ_ONCE(dev->mtu) < so->ll.mtu) {
+		err = -EINVAL;
+		goto out_put_dev;
+	}
+	if (!(dev->flags & IFF_UP))
+		notify_enetdown = 1;
+
+	ifindex = dev->ifindex;
+
+	if (isotp_register_rxid(so))
+		can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
+				isotp_rcv, sk, "isotp", sk);
+
+	/* no consecutive frame echo skb in flight */
+	WRITE_ONCE(so->cfecho, 0);
+
+	/* register for echo skb's */
+	can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
+			isotp_rcv_echo, sk, "isotpe", sk);
+
+	/* switch to new settings */
+	so->ifindex = ifindex;
+	so->rxid = rx_id;
+	so->txid = tx_id;
+	so->bound = 1;
+
+	/* bind() ok -> hold a reference for so->dev so that isotp_release()
+	 * can safely reach the device later, even if a concurrent
+	 * NETDEV_UNREGISTER has already unlisted it by ifindex.
+	 */
+	so->dev = dev;
+	netdev_hold(so->dev, &so->dev_tracker, GFP_KERNEL);
+
+out_put_dev:
+	/* remove potential reference from dev_get_by_index() */
+	dev_put(dev);
+out:
+	release_sock(sk);
+	rtnl_unlock();
+
+	if (notify_enetdown) {
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+	}
+
+	return err;
+}
+
+static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+
+	if (peer)
+		return -EOPNOTSUPP;
+
+	memset(addr, 0, ISOTP_MIN_NAMELEN);
+	addr->can_family = AF_CAN;
+	addr->can_ifindex = so->ifindex;
+	addr->can_addr.tp.rx_id = so->rxid;
+	addr->can_addr.tp.tx_id = so->txid;
+
+	return ISOTP_MIN_NAMELEN;
+}
+
+static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
+			    sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	int ret = 0;
+
+	if (so->bound)
+		return -EISCONN;
+
+	switch (optname) {
+	case CAN_ISOTP_OPTS:
+		if (optlen != sizeof(struct can_isotp_options))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&so->opt, optval, optlen))
+			return -EFAULT;
+
+		/* no separate rx_ext_address is given => use ext_address */
+		if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
+			so->opt.rx_ext_address = so->opt.ext_address;
+
+		/* these broadcast flags are not allowed together */
+		if (isotp_bc_flags(so) == ISOTP_ALL_BC_FLAGS) {
+			/* CAN_ISOTP_SF_BROADCAST is prioritized */
+			so->opt.flags &= ~CAN_ISOTP_CF_BROADCAST;
+
+			/* give user feedback on wrong config attempt */
+			ret = -EINVAL;
+		}
+
+		/* check for frame_txtime changes (0 => no changes) */
+		if (so->opt.frame_txtime) {
+			if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
+				so->frame_txtime = 0;
+			else
+				so->frame_txtime = so->opt.frame_txtime;
+		}
+		break;
+
+	case CAN_ISOTP_RECV_FC:
+		if (optlen != sizeof(struct can_isotp_fc_options))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&so->rxfc, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_TX_STMIN:
+		if (optlen != sizeof(u32))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_RX_STMIN:
+		if (optlen != sizeof(u32))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
+			return -EFAULT;
+		break;
+
+	case CAN_ISOTP_LL_OPTS:
+		if (optlen == sizeof(struct can_isotp_ll_options)) {
+			struct can_isotp_ll_options ll;
+
+			if (copy_from_sockptr(&ll, optval, optlen))
+				return -EFAULT;
+
+			/* check for correct ISO 11898-1 DLC data length */
+			if (ll.tx_dl != padlen(ll.tx_dl))
+				return -EINVAL;
+
+			if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
+				return -EINVAL;
+
+			if (ll.mtu == CAN_MTU &&
+			    (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
+				return -EINVAL;
+
+			memcpy(&so->ll, &ll, sizeof(ll));
+
+			/* set ll_dl for tx path to similar place as for rx */
+			so->tx.ll_dl = ll.tx_dl;
+		} else {
+			return -EINVAL;
+		}
+		break;
+
+	default:
+		ret = -ENOPROTOOPT;
+	}
+
+	return ret;
+}
+
+static int isotp_setsockopt(struct socket *sock, int level, int optname,
+			    sockptr_t optval, unsigned int optlen)
+
+{
+	struct sock *sk = sock->sk;
+	int ret;
+
+	if (level != SOL_CAN_ISOTP)
+		return -EINVAL;
+
+	lock_sock(sk);
+	ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
+	release_sock(sk);
+	return ret;
+}
+
+static int isotp_getsockopt(struct socket *sock, int level, int optname,
+			    char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+	int len;
+	void *val;
+
+	if (level != SOL_CAN_ISOTP)
+		return -EINVAL;
+	if (get_user(len, optlen))
+		return -EFAULT;
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case CAN_ISOTP_OPTS:
+		len = min_t(int, len, sizeof(struct can_isotp_options));
+		val = &so->opt;
+		break;
+
+	case CAN_ISOTP_RECV_FC:
+		len = min_t(int, len, sizeof(struct can_isotp_fc_options));
+		val = &so->rxfc;
+		break;
+
+	case CAN_ISOTP_TX_STMIN:
+		len = min_t(int, len, sizeof(u32));
+		val = &so->force_tx_stmin;
+		break;
+
+	case CAN_ISOTP_RX_STMIN:
+		len = min_t(int, len, sizeof(u32));
+		val = &so->force_rx_stmin;
+		break;
+
+	case CAN_ISOTP_LL_OPTS:
+		len = min_t(int, len, sizeof(struct can_isotp_ll_options));
+		val = &so->ll;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (copy_to_user(optval, val, len))
+		return -EFAULT;
+	return 0;
+}
+
+static void isotp_notify(struct isotp_sock *so, unsigned long msg,
+			 struct net_device *dev)
+{
+	struct sock *sk = &so->sk;
+
+	if (!net_eq(dev_net(dev), sock_net(sk)))
+		return;
+
+	if (so->dev != dev)
+		return;
+
+	switch (msg) {
+	case NETDEV_UNREGISTER:
+		lock_sock(sk);
+		/* remove current filters & unregister */
+		if (so->bound) {
+			if (isotp_register_rxid(so))
+				can_rx_unregister(dev_net(dev), dev, so->rxid,
+						  SINGLE_MASK(so->rxid),
+						  isotp_rcv, sk);
+
+			can_rx_unregister(dev_net(dev), dev, so->txid,
+					  SINGLE_MASK(so->txid),
+					  isotp_rcv_echo, sk);
+			netdev_put(so->dev, &so->dev_tracker);
+		}
+
+		so->ifindex = 0;
+		so->bound  = 0;
+		so->dev = NULL;
+		release_sock(sk);
+
+		sk->sk_err = ENODEV;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+		break;
+
+	case NETDEV_DOWN:
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+		break;
+	}
+}
+
+static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
+			  void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+	if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+		return NOTIFY_DONE;
+	if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
+		return NOTIFY_DONE;
+
+	spin_lock(&isotp_notifier_lock);
+	list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
+		spin_unlock(&isotp_notifier_lock);
+		isotp_notify(isotp_busy_notifier, msg, dev);
+		spin_lock(&isotp_notifier_lock);
+	}
+	isotp_busy_notifier = NULL;
+	spin_unlock(&isotp_notifier_lock);
+	return NOTIFY_DONE;
+}
+
+static void isotp_sock_destruct(struct sock *sk)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+
+	/* do the standard CAN sock destruct work */
+	can_sock_destruct(sk);
+
+	/* free potential extended PDU buffers */
+	if (so->rx.buf != so->rx.sbuf)
+		kfree(so->rx.buf);
+
+	if (so->tx.buf != so->tx.sbuf)
+		kfree(so->tx.buf);
+}
+
+static int isotp_init(struct sock *sk)
+{
+	struct isotp_sock *so = isotp_sk(sk);
+
+	so->ifindex = 0;
+	so->bound = 0;
+	so->dev = NULL;
+
+	so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
+	so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+	so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+	so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
+	so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
+	so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
+	so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
+	so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
+	so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
+	so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
+	so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
+	so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
+	so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
+
+	/* set ll_dl for tx path to similar place as for rx */
+	so->tx.ll_dl = so->ll.tx_dl;
+
+	so->rx.state = ISOTP_IDLE;
+	so->tx.state = ISOTP_IDLE;
+
+	so->rx.buf = so->rx.sbuf;
+	so->tx.buf = so->tx.sbuf;
+	so->rx.buflen = ARRAY_SIZE(so->rx.sbuf);
+	so->tx.buflen = ARRAY_SIZE(so->tx.sbuf);
+
+	hrtimer_setup(&so->rxtimer, isotp_rx_timer_handler,
+		      CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	hrtimer_setup(&so->txtimer, isotp_tx_timer_handler,
+		      CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	hrtimer_setup(&so->echotimer, isotp_echo_timer_handler,
+		      CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	hrtimer_setup(&so->txfrtimer, isotp_txfr_timer_handler,
+		      CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+
+	init_waitqueue_head(&so->wait);
+	spin_lock_init(&so->rx_lock);
+
+	spin_lock(&isotp_notifier_lock);
+	list_add_tail(&so->notifier, &isotp_notifier_list);
+	spin_unlock(&isotp_notifier_lock);
+
+	/* re-assign default can_sock_destruct() reference */
+	sk->sk_destruct = isotp_sock_destruct;
+
+	return 0;
+}
+
+static __poll_t isotp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct isotp_sock *so = isotp_sk(sk);
+
+	__poll_t mask = datagram_poll(file, sock, wait);
+	poll_wait(file, &so->wait, wait);
+
+	/* Check for false positives due to TX state */
+	if ((mask & EPOLLWRNORM) && (READ_ONCE(so->tx.state) != ISOTP_IDLE))
+		mask &= ~(EPOLLOUT | EPOLLWRNORM);
+
+	return mask;
+}
+
+static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+				  unsigned long arg)
+{
+	/* no ioctls for socket layer -> hand it down to NIC layer */
+	return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops isotp_ops = {
+	.family = PF_CAN,
+	.release = isotp_release,
+	.bind = isotp_bind,
+	.connect = sock_no_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = isotp_getname,
+	.poll = isotp_poll,
+	.ioctl = isotp_sock_no_ioctlcmd,
+	.gettstamp = sock_gettstamp,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = isotp_setsockopt,
+	.getsockopt = isotp_getsockopt,
+	.sendmsg = isotp_sendmsg,
+	.recvmsg = isotp_recvmsg,
+	.mmap = sock_no_mmap,
+};
+
+static struct proto isotp_proto __read_mostly = {
+	.name = "CAN_ISOTP",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct isotp_sock),
+	.init = isotp_init,
+};
+
+static const struct can_proto isotp_can_proto = {
+	.type = SOCK_DGRAM,
+	.protocol = CAN_ISOTP,
+	.ops = &isotp_ops,
+	.prot = &isotp_proto,
+};
+
+static struct notifier_block canisotp_notifier = {
+	.notifier_call = isotp_notifier
+};
+
+static __init int isotp_module_init(void)
+{
+	int err;
+
+	max_pdu_size = max_t(unsigned int, max_pdu_size, MAX_12BIT_PDU_SIZE);
+	max_pdu_size = min_t(unsigned int, max_pdu_size, MAX_PDU_SIZE);
+
+	pr_info("can: isotp protocol (max_pdu_size %d)\n", max_pdu_size);
+
+	err = register_netdevice_notifier(&canisotp_notifier);
+	if (err)
+		return err;
+
+	err = can_proto_register(&isotp_can_proto);
+	if (err < 0) {
+		pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
+		unregister_netdevice_notifier(&canisotp_notifier);
+		return err;
+	}
+
+	return 0;
+}
+
+static __exit void isotp_module_exit(void)
+{
+	can_proto_unregister(&isotp_can_proto);
+	unregister_netdevice_notifier(&canisotp_notifier);
+}
+
+module_init(isotp_module_init);
+module_exit(isotp_module_exit);
diff --git a/net/can/j1939/Kconfig b/net/can/j1939/Kconfig
new file mode 100644
index 000000000..2998298b7
--- /dev/null
+++ b/net/can/j1939/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# SAE J1939 network layer core configuration
+#
+
+config CAN_J1939
+	tristate "SAE J1939"
+	depends on CAN
+	help
+	  SAE J1939
+	  Say Y to have in-kernel support for j1939 socket type. This
+	  allows communication according to SAE j1939.
+	  The relevant parts in kernel are
+	  SAE j1939-21 (datalink & transport protocol)
+	  & SAE j1939-81 (network management).
diff --git a/net/can/j1939/Makefile b/net/can/j1939/Makefile
new file mode 100644
index 000000000..19181bdae
--- /dev/null
+++ b/net/can/j1939/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_CAN_J1939) += can-j1939.o
+
+can-j1939-objs := \
+	address-claim.o \
+	bus.o \
+	main.o \
+	socket.o \
+	transport.o
diff --git a/net/can/j1939/address-claim.c b/net/can/j1939/address-claim.c
new file mode 100644
index 000000000..ca4ad6cdd
--- /dev/null
+++ b/net/can/j1939/address-claim.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <pieter.beyens@eia.be>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+/* J1939 Address Claiming.
+ * Address Claiming in the kernel
+ * - keeps track of the AC states of ECU's,
+ * - resolves NAME<=>SA taking into account the AC states of ECU's.
+ *
+ * All Address Claim msgs (including host-originated msg) are processed
+ * at the receive path (a sent msg is always received again via CAN echo).
+ * As such, the processing of AC msgs is done in the order on which msgs
+ * are sent on the bus.
+ *
+ * This module doesn't send msgs itself (e.g. replies on Address Claims),
+ * this is the responsibility of a user space application or daemon.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+#include "j1939-priv.h"
+
+static inline name_t j1939_skb_to_name(const struct sk_buff *skb)
+{
+	return le64_to_cpup((__le64 *)skb->data);
+}
+
+static inline bool j1939_ac_msg_is_request(struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int req_pgn;
+
+	if (skb->len < 3 || skcb->addr.pgn != J1939_PGN_REQUEST)
+		return false;
+
+	req_pgn = skb->data[0] | (skb->data[1] << 8) | (skb->data[2] << 16);
+
+	return req_pgn == J1939_PGN_ADDRESS_CLAIMED;
+}
+
+static int j1939_ac_verify_outgoing(struct j1939_priv *priv,
+				    struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+
+	if (skb->len != 8) {
+		netdev_notice(priv->ndev, "tx address claim with dlc %i\n",
+			      skb->len);
+		return -EPROTO;
+	}
+
+	if (skcb->addr.src_name != j1939_skb_to_name(skb)) {
+		netdev_notice(priv->ndev, "tx address claim with different name\n");
+		return -EPROTO;
+	}
+
+	if (skcb->addr.sa == J1939_NO_ADDR) {
+		netdev_notice(priv->ndev, "tx address claim with broadcast sa\n");
+		return -EPROTO;
+	}
+
+	/* ac must always be a broadcast */
+	if (skcb->addr.dst_name || skcb->addr.da != J1939_NO_ADDR) {
+		netdev_notice(priv->ndev, "tx address claim with dest, not broadcast\n");
+		return -EPROTO;
+	}
+	return 0;
+}
+
+int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int ret;
+	u8 addr;
+
+	/* network mgmt: address claiming msgs */
+	if (skcb->addr.pgn == J1939_PGN_ADDRESS_CLAIMED) {
+		struct j1939_ecu *ecu;
+
+		ret = j1939_ac_verify_outgoing(priv, skb);
+		/* return both when failure & when successful */
+		if (ret < 0)
+			return ret;
+		ecu = j1939_ecu_get_by_name(priv, skcb->addr.src_name);
+		if (!ecu)
+			return -ENODEV;
+
+		if (ecu->addr != skcb->addr.sa)
+			/* hold further traffic for ecu, remove from parent */
+			j1939_ecu_unmap(ecu);
+		j1939_ecu_put(ecu);
+	} else if (skcb->addr.src_name) {
+		/* assign source address */
+		addr = j1939_name_to_addr(priv, skcb->addr.src_name);
+		if (!j1939_address_is_unicast(addr) &&
+		    !j1939_ac_msg_is_request(skb)) {
+			netdev_notice(priv->ndev, "tx drop: invalid sa for name 0x%016llx\n",
+				      skcb->addr.src_name);
+			return -EADDRNOTAVAIL;
+		}
+		skcb->addr.sa = addr;
+	}
+
+	/* assign destination address */
+	if (skcb->addr.dst_name) {
+		addr = j1939_name_to_addr(priv, skcb->addr.dst_name);
+		if (!j1939_address_is_unicast(addr)) {
+			netdev_notice(priv->ndev, "tx drop: invalid da for name 0x%016llx\n",
+				      skcb->addr.dst_name);
+			return -EADDRNOTAVAIL;
+		}
+		skcb->addr.da = addr;
+	}
+	return 0;
+}
+
+static void j1939_ac_process(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_ecu *ecu, *prev;
+	name_t name;
+
+	if (skb->len != 8) {
+		netdev_notice(priv->ndev, "rx address claim with wrong dlc %i\n",
+			      skb->len);
+		return;
+	}
+
+	name = j1939_skb_to_name(skb);
+	skcb->addr.src_name = name;
+	if (!name) {
+		netdev_notice(priv->ndev, "rx address claim without name\n");
+		return;
+	}
+
+	if (!j1939_address_is_valid(skcb->addr.sa)) {
+		netdev_notice(priv->ndev, "rx address claim with broadcast sa\n");
+		return;
+	}
+
+	write_lock_bh(&priv->lock);
+
+	/* Few words on the ECU ref counting:
+	 *
+	 * First we get an ECU handle, either with
+	 * j1939_ecu_get_by_name_locked() (increments the ref counter)
+	 * or j1939_ecu_create_locked() (initializes an ECU object
+	 * with a ref counter of 1).
+	 *
+	 * j1939_ecu_unmap_locked() will decrement the ref counter,
+	 * but only if the ECU was mapped before. So "ecu" still
+	 * belongs to us.
+	 *
+	 * j1939_ecu_timer_start() will increment the ref counter
+	 * before it starts the timer, so we can put the ecu when
+	 * leaving this function.
+	 */
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+
+	if (ecu && ecu->addr == skcb->addr.sa) {
+		/* The ISO 11783-5 standard, in "4.5.2 - Address claim
+		 * requirements", states:
+		 *   d) No CF shall begin, or resume, transmission on the
+		 *      network until 250 ms after it has successfully claimed
+		 *      an address except when responding to a request for
+		 *      address-claimed.
+		 *
+		 * But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
+		 * prioritization" show that the CF begins the transmission
+		 * after 250 ms from the first AC (address-claimed) message
+		 * even if it sends another AC message during that time window
+		 * to resolve the address contention with another CF.
+		 *
+		 * As stated in "4.4.2.3 - Address-claimed message":
+		 *   In order to successfully claim an address, the CF sending
+		 *   an address claimed message shall not receive a contending
+		 *   claim from another CF for at least 250 ms.
+		 *
+		 * As stated in "4.4.3.2 - NAME management (NM) message":
+		 *   1) A commanding CF can
+		 *      d) request that a CF with a specified NAME transmit
+		 *         the address-claimed message with its current NAME.
+		 *   2) A target CF shall
+		 *      d) send an address-claimed message in response to a
+		 *         request for a matching NAME
+		 *
+		 * Taking the above arguments into account, the 250 ms wait is
+		 * requested only during network initialization.
+		 *
+		 * Do not restart the timer on AC message if both the NAME and
+		 * the address match and so if the address has already been
+		 * claimed (timer has expired) or the AC message has been sent
+		 * to resolve the contention with another CF (timer is still
+		 * running).
+		 */
+		goto out_ecu_put;
+	}
+
+	if (!ecu && j1939_address_is_unicast(skcb->addr.sa))
+		ecu = j1939_ecu_create_locked(priv, name);
+
+	if (IS_ERR_OR_NULL(ecu))
+		goto out_unlock_bh;
+
+	/* cancel pending (previous) address claim */
+	j1939_ecu_timer_cancel(ecu);
+
+	if (j1939_address_is_idle(skcb->addr.sa)) {
+		j1939_ecu_unmap_locked(ecu);
+		goto out_ecu_put;
+	}
+
+	/* save new addr */
+	if (ecu->addr != skcb->addr.sa)
+		j1939_ecu_unmap_locked(ecu);
+	ecu->addr = skcb->addr.sa;
+
+	prev = j1939_ecu_get_by_addr_locked(priv, skcb->addr.sa);
+	if (prev) {
+		if (ecu->name > prev->name) {
+			j1939_ecu_unmap_locked(ecu);
+			j1939_ecu_put(prev);
+			goto out_ecu_put;
+		} else {
+			/* kick prev if less or equal */
+			j1939_ecu_unmap_locked(prev);
+			j1939_ecu_put(prev);
+		}
+	}
+
+	j1939_ecu_timer_start(ecu);
+ out_ecu_put:
+	j1939_ecu_put(ecu);
+ out_unlock_bh:
+	write_unlock_bh(&priv->lock);
+}
+
+void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_ecu *ecu;
+
+	/* network mgmt */
+	if (skcb->addr.pgn == J1939_PGN_ADDRESS_CLAIMED) {
+		j1939_ac_process(priv, skb);
+	} else if (j1939_address_is_unicast(skcb->addr.sa)) {
+		/* assign source name */
+		ecu = j1939_ecu_get_by_addr(priv, skcb->addr.sa);
+		if (ecu) {
+			skcb->addr.src_name = ecu->name;
+			j1939_ecu_put(ecu);
+		}
+	}
+
+	/* assign destination name */
+	ecu = j1939_ecu_get_by_addr(priv, skcb->addr.da);
+	if (ecu) {
+		skcb->addr.dst_name = ecu->name;
+		j1939_ecu_put(ecu);
+	}
+}
diff --git a/net/can/j1939/bus.c b/net/can/j1939/bus.c
new file mode 100644
index 000000000..cdc3c0a71
--- /dev/null
+++ b/net/can/j1939/bus.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+/* bus for j1939 remote devices
+ * Since rtnetlink, no real bus is used.
+ */
+
+#include <net/sock.h>
+
+#include "j1939-priv.h"
+
+static void __j1939_ecu_release(struct kref *kref)
+{
+	struct j1939_ecu *ecu = container_of(kref, struct j1939_ecu, kref);
+	struct j1939_priv *priv = ecu->priv;
+
+	list_del(&ecu->list);
+	netdev_put(priv->ndev, &ecu->priv_dev_tracker);
+	kfree(ecu);
+	j1939_priv_put(priv);
+}
+
+void j1939_ecu_put(struct j1939_ecu *ecu)
+{
+	kref_put(&ecu->kref, __j1939_ecu_release);
+}
+
+static void j1939_ecu_get(struct j1939_ecu *ecu)
+{
+	kref_get(&ecu->kref);
+}
+
+static bool j1939_ecu_is_mapped_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+
+	lockdep_assert_held(&priv->lock);
+
+	return j1939_ecu_find_by_addr_locked(priv, ecu->addr) == ecu;
+}
+
+/* ECU device interface */
+/* map ECU to a bus address space */
+static void j1939_ecu_map_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+	struct j1939_addr_ent *ent;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(ecu->addr))
+		return;
+
+	ent = &priv->ents[ecu->addr];
+
+	if (ent->ecu) {
+		netdev_warn(priv->ndev, "Trying to map already mapped ECU, addr: 0x%02x, name: 0x%016llx. Skip it.\n",
+			    ecu->addr, ecu->name);
+		return;
+	}
+
+	j1939_ecu_get(ecu);
+	ent->ecu = ecu;
+	ent->nusers += ecu->nusers;
+}
+
+/* unmap ECU from a bus address space */
+void j1939_ecu_unmap_locked(struct j1939_ecu *ecu)
+{
+	struct j1939_priv *priv = ecu->priv;
+	struct j1939_addr_ent *ent;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(ecu->addr))
+		return;
+
+	if (!j1939_ecu_is_mapped_locked(ecu))
+		return;
+
+	ent = &priv->ents[ecu->addr];
+	ent->ecu = NULL;
+	ent->nusers -= ecu->nusers;
+	j1939_ecu_put(ecu);
+}
+
+void j1939_ecu_unmap(struct j1939_ecu *ecu)
+{
+	write_lock_bh(&ecu->priv->lock);
+	j1939_ecu_unmap_locked(ecu);
+	write_unlock_bh(&ecu->priv->lock);
+}
+
+void j1939_ecu_unmap_all(struct j1939_priv *priv)
+{
+	int i;
+
+	write_lock_bh(&priv->lock);
+	for (i = 0; i < ARRAY_SIZE(priv->ents); i++)
+		if (priv->ents[i].ecu)
+			j1939_ecu_unmap_locked(priv->ents[i].ecu);
+	write_unlock_bh(&priv->lock);
+}
+
+void j1939_ecu_timer_start(struct j1939_ecu *ecu)
+{
+	/* The ECU is held here and released in the
+	 * j1939_ecu_timer_handler() or j1939_ecu_timer_cancel().
+	 */
+	j1939_ecu_get(ecu);
+
+	/* Schedule timer in 250 msec to commit address change. */
+	hrtimer_start(&ecu->ac_timer, ms_to_ktime(250),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+void j1939_ecu_timer_cancel(struct j1939_ecu *ecu)
+{
+	if (hrtimer_cancel(&ecu->ac_timer))
+		j1939_ecu_put(ecu);
+}
+
+static enum hrtimer_restart j1939_ecu_timer_handler(struct hrtimer *hrtimer)
+{
+	struct j1939_ecu *ecu =
+		container_of(hrtimer, struct j1939_ecu, ac_timer);
+	struct j1939_priv *priv = ecu->priv;
+
+	write_lock_bh(&priv->lock);
+	/* TODO: can we test if ecu->addr is unicast before starting
+	 * the timer?
+	 */
+	j1939_ecu_map_locked(ecu);
+
+	/* The corresponding j1939_ecu_get() is in
+	 * j1939_ecu_timer_start().
+	 */
+	j1939_ecu_put(ecu);
+	write_unlock_bh(&priv->lock);
+
+	return HRTIMER_NORESTART;
+}
+
+struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	ecu = kzalloc_obj(*ecu, gfp_any());
+	if (!ecu)
+		return ERR_PTR(-ENOMEM);
+	kref_init(&ecu->kref);
+	netdev_hold(priv->ndev, &ecu->priv_dev_tracker, gfp_any());
+	ecu->addr = J1939_IDLE_ADDR;
+	ecu->name = name;
+
+	hrtimer_setup(&ecu->ac_timer, j1939_ecu_timer_handler, CLOCK_MONOTONIC,
+		      HRTIMER_MODE_REL_SOFT);
+	INIT_LIST_HEAD(&ecu->list);
+
+	j1939_priv_get(priv);
+	ecu->priv = priv;
+	list_add_tail(&ecu->list, &priv->ecus);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
+						u8 addr)
+{
+	lockdep_assert_held(&priv->lock);
+
+	return priv->ents[addr].ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv, u8 addr)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!j1939_address_is_unicast(addr))
+		return NULL;
+
+	ecu = j1939_ecu_find_by_addr_locked(priv, addr);
+	if (ecu)
+		j1939_ecu_get(ecu);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr)
+{
+	struct j1939_ecu *ecu;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_get_by_addr_locked(priv, addr);
+	read_unlock_bh(&priv->lock);
+
+	return ecu;
+}
+
+/* get pointer to ecu without increasing ref counter */
+static struct j1939_ecu *j1939_ecu_find_by_name_locked(struct j1939_priv *priv,
+						       name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	list_for_each_entry(ecu, &priv->ecus, list) {
+		if (ecu->name == name)
+			return ecu;
+	}
+
+	return NULL;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
+					       name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	lockdep_assert_held(&priv->lock);
+
+	if (!name)
+		return NULL;
+
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (ecu)
+		j1939_ecu_get(ecu);
+
+	return ecu;
+}
+
+struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+	read_unlock_bh(&priv->lock);
+
+	return ecu;
+}
+
+u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name)
+{
+	struct j1939_ecu *ecu;
+	int addr = J1939_IDLE_ADDR;
+
+	if (!name)
+		return J1939_NO_ADDR;
+
+	read_lock_bh(&priv->lock);
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (ecu && j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's SA is registered */
+		addr = ecu->addr;
+
+	read_unlock_bh(&priv->lock);
+
+	return addr;
+}
+
+/* TX addr/name accounting
+ * Transport protocol needs to know if a SA is local or not
+ * These functions originate from userspace manipulating sockets,
+ * so locking is straigforward
+ */
+
+int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa)
+{
+	struct j1939_ecu *ecu;
+	int err = 0;
+
+	write_lock_bh(&priv->lock);
+
+	if (j1939_address_is_unicast(sa))
+		priv->ents[sa].nusers++;
+
+	if (!name)
+		goto done;
+
+	ecu = j1939_ecu_get_by_name_locked(priv, name);
+	if (!ecu)
+		ecu = j1939_ecu_create_locked(priv, name);
+	err = PTR_ERR_OR_ZERO(ecu);
+	if (err) {
+		if (j1939_address_is_unicast(sa))
+			priv->ents[sa].nusers--;
+		goto done;
+	}
+
+	ecu->nusers++;
+	/* TODO: do we care if ecu->addr != sa? */
+	if (j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's sa is active already */
+		priv->ents[ecu->addr].nusers++;
+
+ done:
+	write_unlock_bh(&priv->lock);
+
+	return err;
+}
+
+void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa)
+{
+	struct j1939_ecu *ecu;
+
+	write_lock_bh(&priv->lock);
+
+	if (j1939_address_is_unicast(sa))
+		priv->ents[sa].nusers--;
+
+	if (!name)
+		goto done;
+
+	ecu = j1939_ecu_find_by_name_locked(priv, name);
+	if (WARN_ON_ONCE(!ecu))
+		goto done;
+
+	ecu->nusers--;
+	/* TODO: do we care if ecu->addr != sa? */
+	if (j1939_ecu_is_mapped_locked(ecu))
+		/* ecu's sa is active already */
+		priv->ents[ecu->addr].nusers--;
+	j1939_ecu_put(ecu);
+
+ done:
+	write_unlock_bh(&priv->lock);
+}
diff --git a/net/can/j1939/j1939-priv.h b/net/can/j1939/j1939-priv.h
new file mode 100644
index 000000000..cf26352d1
--- /dev/null
+++ b/net/can/j1939/j1939-priv.h
@@ -0,0 +1,348 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+#ifndef _J1939_PRIV_H_
+#define _J1939_PRIV_H_
+
+#include <linux/can/j1939.h>
+#include <net/sock.h>
+
+/* Timeout to receive the abort signal over loop back. In case CAN
+ * bus is open, the timeout should be triggered.
+ */
+#define J1939_XTP_ABORT_TIMEOUT_MS 500
+#define J1939_SIMPLE_ECHO_TIMEOUT_MS (10 * 1000)
+
+struct j1939_session;
+enum j1939_sk_errqueue_type {
+	J1939_ERRQUEUE_TX_ACK,
+	J1939_ERRQUEUE_TX_SCHED,
+	J1939_ERRQUEUE_TX_ABORT,
+	J1939_ERRQUEUE_RX_RTS,
+	J1939_ERRQUEUE_RX_DPO,
+	J1939_ERRQUEUE_RX_ABORT,
+};
+
+/* j1939 devices */
+struct j1939_ecu {
+	struct list_head list;
+	name_t name;
+	u8 addr;
+
+	/* indicates that this ecu successfully claimed @sa as its address */
+	struct hrtimer ac_timer;
+	struct kref kref;
+	struct j1939_priv *priv;
+	netdevice_tracker priv_dev_tracker;
+
+	/* count users, to help transport protocol decide for interaction */
+	int nusers;
+};
+
+struct j1939_priv {
+	struct list_head ecus;
+	/* local list entry in priv
+	 * These allow irq (& softirq) context lookups on j1939 devices
+	 * This approach (separate lists) is done as the other 2 alternatives
+	 * are not easier or even wrong
+	 * 1) using the pure kobject methods involves mutexes, which are not
+	 *    allowed in irq context.
+	 * 2) duplicating data structures would require a lot of synchronization
+	 *    code
+	 * usage:
+	 */
+
+	/* segments need a lock to protect the above list */
+	rwlock_t lock;
+
+	struct net_device *ndev;
+	netdevice_tracker dev_tracker;
+
+	/* list of 256 ecu ptrs, that cache the claimed addresses.
+	 * also protected by the above lock
+	 */
+	struct j1939_addr_ent {
+		struct j1939_ecu *ecu;
+		/* count users, to help transport protocol */
+		int nusers;
+	} ents[256];
+
+	struct kref kref;
+
+	/* List of active sessions to prevent start of conflicting
+	 * one.
+	 *
+	 * Do not start two sessions of same type, addresses and
+	 * direction.
+	 */
+	struct list_head active_session_list;
+
+	/* protects active_session_list */
+	spinlock_t active_session_list_lock;
+
+	unsigned int tp_max_packet_size;
+
+	/* lock for j1939_socks list */
+	rwlock_t j1939_socks_lock;
+	struct list_head j1939_socks;
+
+	struct kref rx_kref;
+	u32 rx_tskey;
+};
+
+void j1939_ecu_put(struct j1939_ecu *ecu);
+
+/* keep the cache of what is local */
+int j1939_local_ecu_get(struct j1939_priv *priv, name_t name, u8 sa);
+void j1939_local_ecu_put(struct j1939_priv *priv, name_t name, u8 sa);
+
+static inline bool j1939_address_is_unicast(u8 addr)
+{
+	return addr <= J1939_MAX_UNICAST_ADDR;
+}
+
+static inline bool j1939_address_is_idle(u8 addr)
+{
+	return addr == J1939_IDLE_ADDR;
+}
+
+static inline bool j1939_address_is_valid(u8 addr)
+{
+	return addr != J1939_NO_ADDR;
+}
+
+static inline bool j1939_pgn_is_pdu1(pgn_t pgn)
+{
+	/* ignore dp & res bits for this */
+	return (pgn & 0xff00) < 0xf000;
+}
+
+/* utility to correctly unmap an ECU */
+void j1939_ecu_unmap_locked(struct j1939_ecu *ecu);
+void j1939_ecu_unmap(struct j1939_ecu *ecu);
+
+u8 j1939_name_to_addr(struct j1939_priv *priv, name_t name);
+struct j1939_ecu *j1939_ecu_find_by_addr_locked(struct j1939_priv *priv,
+						u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_addr(struct j1939_priv *priv, u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_addr_locked(struct j1939_priv *priv,
+					       u8 addr);
+struct j1939_ecu *j1939_ecu_get_by_name(struct j1939_priv *priv, name_t name);
+struct j1939_ecu *j1939_ecu_get_by_name_locked(struct j1939_priv *priv,
+					       name_t name);
+
+enum j1939_transfer_type {
+	J1939_TP,
+	J1939_ETP,
+	J1939_SIMPLE,
+};
+
+struct j1939_addr {
+	name_t src_name;
+	name_t dst_name;
+	pgn_t pgn;
+
+	u8 sa;
+	u8 da;
+
+	u8 type;
+};
+
+/* control buffer of the sk_buff */
+struct j1939_sk_buff_cb {
+	/* Offset in bytes within one ETP session */
+	u32 offset;
+
+	/* for tx, MSG_SYN will be used to sync on sockets */
+	u32 msg_flags;
+	u32 tskey;
+
+	struct j1939_addr addr;
+
+	/* Flags for quick lookups during skb processing.
+	 * These are set in the receive path only.
+	 */
+#define J1939_ECU_LOCAL_SRC BIT(0)
+#define J1939_ECU_LOCAL_DST BIT(1)
+	u8 flags;
+
+	priority_t priority;
+};
+
+static inline
+struct j1939_sk_buff_cb *j1939_skb_to_cb(const struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(struct j1939_sk_buff_cb) > sizeof(skb->cb));
+
+	return (struct j1939_sk_buff_cb *)skb->cb;
+}
+
+int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb);
+bool j1939_sk_recv_match(struct j1939_priv *priv,
+			 struct j1939_sk_buff_cb *skcb);
+void j1939_sk_send_loop_abort(struct sock *sk, int err);
+void j1939_sk_errqueue(struct j1939_session *session,
+		       enum j1939_sk_errqueue_type type);
+void j1939_sk_queue_activate_next(struct j1939_session *session);
+
+/* stack entries */
+struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
+				    struct sk_buff *skb, size_t size);
+int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb);
+int j1939_ac_fixup(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_ac_recv(struct j1939_priv *priv, struct sk_buff *skb);
+void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb);
+
+/* network management */
+struct j1939_ecu *j1939_ecu_create_locked(struct j1939_priv *priv, name_t name);
+
+void j1939_ecu_timer_start(struct j1939_ecu *ecu);
+void j1939_ecu_timer_cancel(struct j1939_ecu *ecu);
+void j1939_ecu_unmap_all(struct j1939_priv *priv);
+
+struct j1939_priv *j1939_netdev_start(struct net_device *ndev);
+void j1939_netdev_stop(struct j1939_priv *priv);
+
+void j1939_priv_put(struct j1939_priv *priv);
+void j1939_priv_get(struct j1939_priv *priv);
+
+/* notify/alert all j1939 sockets bound to ifindex */
+void j1939_sk_netdev_event_netdown(struct j1939_priv *priv);
+void j1939_sk_netdev_event_unregister(struct j1939_priv *priv);
+int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk);
+void j1939_tp_init(struct j1939_priv *priv);
+
+/* decrement pending skb for a j1939 socket */
+void j1939_sock_pending_del(struct sock *sk);
+
+enum j1939_session_state {
+	J1939_SESSION_NEW,
+	J1939_SESSION_ACTIVE,
+	/* waiting for abort signal on the bus */
+	J1939_SESSION_WAITING_ABORT,
+	J1939_SESSION_ACTIVE_MAX,
+	J1939_SESSION_DONE,
+};
+
+struct j1939_session {
+	struct j1939_priv *priv;
+	netdevice_tracker priv_dev_tracker;
+	struct list_head active_session_list_entry;
+	struct list_head sk_session_queue_entry;
+	struct kref kref;
+	struct sock *sk;
+
+	/* ifindex, src, dst, pgn define the session block
+	 * the are _never_ modified after insertion in the list
+	 * this decreases locking problems a _lot_
+	 */
+	struct j1939_sk_buff_cb skcb;
+	struct sk_buff_head skb_queue;
+
+	/* all tx related stuff (last_txcmd, pkt.tx)
+	 * is protected (modified only) with the txtimer hrtimer
+	 * 'total' & 'block' are never changed,
+	 * last_cmd, last & block are protected by ->lock
+	 * this means that the tx may run after cts is received that should
+	 * have stopped tx, but this time discrepancy is never avoided anyhow
+	 */
+	u8 last_cmd, last_txcmd;
+	bool transmission;
+	bool extd;
+	/* Total message size, number of bytes */
+	unsigned int total_message_size;
+	/* Total number of bytes queue from socket to the session */
+	unsigned int total_queued_size;
+	unsigned int tx_retry;
+
+	int err;
+	u32 tskey;
+	enum j1939_session_state state;
+
+	/* Packets counters for a (extended) transfer session. The packet is
+	 * maximal of 7 bytes.
+	 */
+	struct {
+		/* total - total number of packets for this session */
+		unsigned int total;
+		/* last - last packet of a transfer block after which
+		 * responder should send ETP.CM_CTS and originator
+		 * ETP.CM_DPO
+		 */
+		unsigned int last;
+		/* tx - number of packets send by originator node.
+		 * this counter can be set back if responder node
+		 * didn't received all packets send by originator.
+		 */
+		unsigned int tx;
+		unsigned int tx_acked;
+		/* rx - number of packets received */
+		unsigned int rx;
+		/* block - amount of packets expected in one block */
+		unsigned int block;
+		/* dpo - ETP.CM_DPO, Data Packet Offset */
+		unsigned int dpo;
+	} pkt;
+	struct hrtimer txtimer, rxtimer;
+};
+
+struct j1939_sock {
+	struct sock sk; /* must be first to skip with memset */
+	struct j1939_priv *priv;
+	struct list_head list;
+
+#define J1939_SOCK_BOUND BIT(0)
+#define J1939_SOCK_CONNECTED BIT(1)
+#define J1939_SOCK_PROMISC BIT(2)
+#define J1939_SOCK_ERRQUEUE BIT(3)
+	int state;
+
+	int ifindex;
+	struct j1939_addr addr;
+	spinlock_t filters_lock;
+	struct j1939_filter *filters;
+	int nfilters;
+	pgn_t pgn_rx_filter;
+
+	/* j1939 may emit equal PGN (!= equal CAN-id's) out of order
+	 * when transport protocol comes in.
+	 * To allow emitting in order, keep a 'pending' nr. of packets
+	 */
+	atomic_t skb_pending;
+	wait_queue_head_t waitq;
+
+	/* lock for the sk_session_queue list */
+	spinlock_t sk_session_queue_lock;
+	struct list_head sk_session_queue;
+};
+
+static inline struct j1939_sock *j1939_sk(const struct sock *sk)
+{
+	return container_of(sk, struct j1939_sock, sk);
+}
+
+void j1939_session_get(struct j1939_session *session);
+void j1939_session_put(struct j1939_session *session);
+void j1939_session_skb_queue(struct j1939_session *session,
+			     struct sk_buff *skb);
+int j1939_session_activate(struct j1939_session *session);
+void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec);
+void j1939_session_timers_cancel(struct j1939_session *session);
+
+#define J1939_MIN_TP_PACKET_SIZE 9
+#define J1939_MAX_TP_PACKET_SIZE (7 * 0xff)
+#define J1939_MAX_ETP_PACKET_SIZE (7 * 0x00ffffff)
+
+#define J1939_REGULAR 0
+#define J1939_EXTENDED 1
+
+/* CAN protocol */
+extern const struct can_proto j1939_can_proto;
+
+#endif /* _J1939_PRIV_H_ */
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
new file mode 100644
index 000000000..5e5e6c228
--- /dev/null
+++ b/net/can/j1939/main.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <pieter.beyens@eia.be>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <robin@protonic.nl>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+/* Core of can-j1939 that links j1939 to CAN. */
+
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/if_arp.h>
+#include <linux/module.h>
+
+#include "j1939-priv.h"
+
+MODULE_DESCRIPTION("PF_CAN SAE J1939");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("EIA Electronics (Kurt Van Dijck & Pieter Beyens)");
+MODULE_ALIAS("can-proto-" __stringify(CAN_J1939));
+
+/* LOWLEVEL CAN interface */
+
+/* CAN_HDR: #bytes before can_frame data part */
+#define J1939_CAN_HDR (offsetof(struct can_frame, data))
+
+/* lowest layer */
+static void j1939_can_recv(struct sk_buff *iskb, void *data)
+{
+	struct j1939_priv *priv = data;
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb, *iskcb;
+	struct can_frame *cf;
+
+	/* make sure we only get Classical CAN frames */
+	if (!can_is_can_skb(iskb))
+		return;
+
+	/* create a copy of the skb
+	 * j1939 only delivers the real data bytes,
+	 * the header goes into sockaddr.
+	 * j1939 may not touch the incoming skb in such way
+	 */
+	skb = skb_clone(iskb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	j1939_priv_get(priv);
+	can_skb_set_owner(skb, iskb->sk);
+
+	/* get a pointer to the header of the skb
+	 * the skb payload (pointer) is moved, so that the next skb_data
+	 * returns the actual payload
+	 */
+	cf = (void *)skb->data;
+	skb_pull(skb, J1939_CAN_HDR);
+
+	/* fix length, set to dlc, with 8 maximum */
+	skb_trim(skb, min_t(uint8_t, cf->len, 8));
+
+	/* set addr */
+	skcb = j1939_skb_to_cb(skb);
+	memset(skcb, 0, sizeof(*skcb));
+
+	iskcb = j1939_skb_to_cb(iskb);
+	skcb->tskey = iskcb->tskey;
+	skcb->priority = (cf->can_id >> 26) & 0x7;
+	skcb->addr.sa = cf->can_id;
+	skcb->addr.pgn = (cf->can_id >> 8) & J1939_PGN_MAX;
+	/* set default message type */
+	skcb->addr.type = J1939_TP;
+
+	if (!j1939_address_is_valid(skcb->addr.sa)) {
+		netdev_err_once(priv->ndev, "%s: sa is broadcast address, ignoring!\n",
+				__func__);
+		goto done;
+	}
+
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn)) {
+		/* Type 1: with destination address */
+		skcb->addr.da = skcb->addr.pgn;
+		/* normalize pgn: strip dst address */
+		skcb->addr.pgn &= 0x3ff00;
+	} else {
+		/* set broadcast address */
+		skcb->addr.da = J1939_NO_ADDR;
+	}
+
+	/* update localflags */
+	read_lock_bh(&priv->lock);
+	if (j1939_address_is_unicast(skcb->addr.sa) &&
+	    priv->ents[skcb->addr.sa].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_SRC;
+	if (j1939_address_is_unicast(skcb->addr.da) &&
+	    priv->ents[skcb->addr.da].nusers)
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+	read_unlock_bh(&priv->lock);
+
+	/* deliver into the j1939 stack ... */
+	j1939_ac_recv(priv, skb);
+
+	if (j1939_tp_recv(priv, skb))
+		/* this means the transport layer processed the message */
+		goto done;
+
+	j1939_simple_recv(priv, skb);
+	j1939_sk_recv(priv, skb);
+ done:
+	j1939_priv_put(priv);
+	kfree_skb(skb);
+}
+
+/* NETDEV MANAGEMENT */
+
+/* values for can_rx_(un)register */
+#define J1939_CAN_ID CAN_EFF_FLAG
+#define J1939_CAN_MASK (CAN_EFF_FLAG | CAN_RTR_FLAG)
+
+static DEFINE_MUTEX(j1939_netdev_lock);
+
+static struct j1939_priv *j1939_priv_create(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	priv = kzalloc_obj(*priv);
+	if (!priv)
+		return NULL;
+
+	rwlock_init(&priv->lock);
+	INIT_LIST_HEAD(&priv->ecus);
+	priv->ndev = ndev;
+	kref_init(&priv->kref);
+	kref_init(&priv->rx_kref);
+	netdev_hold(ndev, &priv->dev_tracker, GFP_KERNEL);
+
+	netdev_dbg(priv->ndev, "%s : 0x%p\n", __func__, priv);
+
+	return priv;
+}
+
+static inline void j1939_priv_set(struct net_device *ndev,
+				  struct j1939_priv *priv)
+{
+	struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+
+	can_ml->j1939_priv = priv;
+}
+
+static void __j1939_priv_release(struct kref *kref)
+{
+	struct j1939_priv *priv = container_of(kref, struct j1939_priv, kref);
+	struct net_device *ndev = priv->ndev;
+
+	netdev_dbg(priv->ndev, "%s: 0x%p\n", __func__, priv);
+
+	WARN_ON_ONCE(!list_empty(&priv->active_session_list));
+	WARN_ON_ONCE(!list_empty(&priv->ecus));
+	WARN_ON_ONCE(!list_empty(&priv->j1939_socks));
+
+	netdev_put(ndev, &priv->dev_tracker);
+	kfree(priv);
+}
+
+void j1939_priv_put(struct j1939_priv *priv)
+{
+	kref_put(&priv->kref, __j1939_priv_release);
+}
+
+void j1939_priv_get(struct j1939_priv *priv)
+{
+	kref_get(&priv->kref);
+}
+
+static int j1939_can_rx_register(struct j1939_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+	int ret;
+
+	j1939_priv_get(priv);
+	ret = can_rx_register(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+			      j1939_can_recv, priv, "j1939", NULL);
+	if (ret < 0) {
+		j1939_priv_put(priv);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void j1939_can_rx_unregister(struct j1939_priv *priv)
+{
+	struct net_device *ndev = priv->ndev;
+
+	can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
+			  j1939_can_recv, priv);
+
+	/* The last reference of priv is dropped by the RCU deferred
+	 * j1939_sk_sock_destruct() of the last socket, so we can
+	 * safely drop this reference here.
+	 */
+	j1939_priv_put(priv);
+}
+
+static void __j1939_rx_release(struct kref *kref)
+	__releases(&j1939_netdev_lock)
+{
+	struct j1939_priv *priv = container_of(kref, struct j1939_priv,
+					       rx_kref);
+
+	j1939_can_rx_unregister(priv);
+	j1939_ecu_unmap_all(priv);
+	j1939_priv_set(priv->ndev, NULL);
+	mutex_unlock(&j1939_netdev_lock);
+}
+
+/* get pointer to priv without increasing ref counter */
+static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev)
+{
+	struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+
+	return can_ml->j1939_priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	lockdep_assert_held(&j1939_netdev_lock);
+
+	priv = j1939_ndev_to_priv(ndev);
+	if (priv)
+		j1939_priv_get(priv);
+
+	return priv;
+}
+
+static struct j1939_priv *j1939_priv_get_by_ndev(struct net_device *ndev)
+{
+	struct j1939_priv *priv;
+
+	mutex_lock(&j1939_netdev_lock);
+	priv = j1939_priv_get_by_ndev_locked(ndev);
+	mutex_unlock(&j1939_netdev_lock);
+
+	return priv;
+}
+
+struct j1939_priv *j1939_netdev_start(struct net_device *ndev)
+{
+	struct j1939_priv *priv, *priv_new;
+	int ret;
+
+	mutex_lock(&j1939_netdev_lock);
+	priv = j1939_priv_get_by_ndev_locked(ndev);
+	if (priv) {
+		kref_get(&priv->rx_kref);
+		mutex_unlock(&j1939_netdev_lock);
+		return priv;
+	}
+	mutex_unlock(&j1939_netdev_lock);
+
+	priv = j1939_priv_create(ndev);
+	if (!priv)
+		return ERR_PTR(-ENOMEM);
+
+	j1939_tp_init(priv);
+	rwlock_init(&priv->j1939_socks_lock);
+	INIT_LIST_HEAD(&priv->j1939_socks);
+
+	mutex_lock(&j1939_netdev_lock);
+	priv_new = j1939_priv_get_by_ndev_locked(ndev);
+	if (priv_new) {
+		/* Someone was faster than us, use their priv and roll
+		 * back our's.
+		 */
+		kref_get(&priv_new->rx_kref);
+		mutex_unlock(&j1939_netdev_lock);
+		netdev_put(ndev, &priv->dev_tracker);
+		kfree(priv);
+		return priv_new;
+	}
+	j1939_priv_set(ndev, priv);
+
+	ret = j1939_can_rx_register(priv);
+	if (ret < 0)
+		goto out_priv_put;
+
+	mutex_unlock(&j1939_netdev_lock);
+	return priv;
+
+ out_priv_put:
+	j1939_priv_set(ndev, NULL);
+	mutex_unlock(&j1939_netdev_lock);
+
+	netdev_put(ndev, &priv->dev_tracker);
+	kfree(priv);
+
+	return ERR_PTR(ret);
+}
+
+void j1939_netdev_stop(struct j1939_priv *priv)
+{
+	kref_put_mutex(&priv->rx_kref, __j1939_rx_release, &j1939_netdev_lock);
+	j1939_priv_put(priv);
+}
+
+int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	int ret, dlc;
+	canid_t canid;
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct can_frame *cf;
+
+	/* apply sanity checks */
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+		skcb->addr.pgn &= J1939_PGN_PDU1_MAX;
+	else
+		skcb->addr.pgn &= J1939_PGN_MAX;
+
+	if (skcb->priority > 7)
+		skcb->priority = 6;
+
+	ret = j1939_ac_fixup(priv, skb);
+	if (unlikely(ret))
+		goto failed;
+	dlc = skb->len;
+
+	/* re-claim the CAN_HDR from the SKB */
+	cf = skb_push(skb, J1939_CAN_HDR);
+
+	/* initialize header structure */
+	memset(cf, 0, J1939_CAN_HDR);
+
+	/* make it a full can frame again */
+	skb_put_zero(skb, 8 - dlc);
+
+	canid = CAN_EFF_FLAG |
+		(skcb->priority << 26) |
+		(skcb->addr.pgn << 8) |
+		skcb->addr.sa;
+	if (j1939_pgn_is_pdu1(skcb->addr.pgn))
+		canid |= skcb->addr.da << 8;
+
+	cf->can_id = canid;
+	cf->len = dlc;
+
+	return can_send(skb, 1);
+
+ failed:
+	kfree_skb(skb);
+	return ret;
+}
+
+static int j1939_netdev_notify(struct notifier_block *nb,
+			       unsigned long msg, void *data)
+{
+	struct net_device *ndev = netdev_notifier_info_to_dev(data);
+	struct can_ml_priv *can_ml = can_get_ml_priv(ndev);
+	struct j1939_priv *priv;
+
+	if (!can_ml)
+		goto notify_done;
+
+	priv = j1939_priv_get_by_ndev(ndev);
+	if (!priv)
+		goto notify_done;
+
+	switch (msg) {
+	case NETDEV_DOWN:
+		j1939_cancel_active_session(priv, NULL);
+		j1939_sk_netdev_event_netdown(priv);
+		j1939_ecu_unmap_all(priv);
+		break;
+	case NETDEV_UNREGISTER:
+		j1939_cancel_active_session(priv, NULL);
+		j1939_sk_netdev_event_netdown(priv);
+		j1939_sk_netdev_event_unregister(priv);
+		break;
+	}
+
+	j1939_priv_put(priv);
+
+notify_done:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block j1939_netdev_notifier = {
+	.notifier_call = j1939_netdev_notify,
+};
+
+/* MODULE interface */
+static __init int j1939_module_init(void)
+{
+	int ret;
+
+	pr_info("can: SAE J1939\n");
+
+	ret = register_netdevice_notifier(&j1939_netdev_notifier);
+	if (ret)
+		goto fail_notifier;
+
+	ret = can_proto_register(&j1939_can_proto);
+	if (ret < 0) {
+		pr_err("can: registration of j1939 protocol failed\n");
+		goto fail_sk;
+	}
+
+	return 0;
+
+ fail_sk:
+	unregister_netdevice_notifier(&j1939_netdev_notifier);
+ fail_notifier:
+	return ret;
+}
+
+static __exit void j1939_module_exit(void)
+{
+	can_proto_unregister(&j1939_can_proto);
+
+	unregister_netdevice_notifier(&j1939_netdev_notifier);
+}
+
+module_init(j1939_module_init);
+module_exit(j1939_module_exit);
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
new file mode 100644
index 000000000..50a598ef5
--- /dev/null
+++ b/net/can/j1939/socket.c
@@ -0,0 +1,1406 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Pieter Beyens <pieter.beyens@eia.be>
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <robin@protonic.nl>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/errqueue.h>
+#include <linux/if_arp.h>
+#include <net/can.h>
+
+#include "j1939-priv.h"
+
+#define J1939_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.j1939)
+
+/* conversion function between struct sock::sk_priority from linux and
+ * j1939 priority field
+ */
+static inline priority_t j1939_prio(u32 sk_priority)
+{
+	sk_priority = min(sk_priority, 7U);
+
+	return 7 - sk_priority;
+}
+
+static inline u32 j1939_to_sk_priority(priority_t prio)
+{
+	return 7 - prio;
+}
+
+/* function to see if pgn is to be evaluated */
+static inline bool j1939_pgn_is_valid(pgn_t pgn)
+{
+	return pgn <= J1939_PGN_MAX;
+}
+
+/* test function to avoid non-zero DA placeholder for pdu1 pgn's */
+static inline bool j1939_pgn_is_clean_pdu(pgn_t pgn)
+{
+	if (j1939_pgn_is_pdu1(pgn))
+		return !(pgn & 0xff);
+	else
+		return true;
+}
+
+static inline void j1939_sock_pending_add(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	atomic_inc(&jsk->skb_pending);
+}
+
+static int j1939_sock_pending_get(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	return atomic_read(&jsk->skb_pending);
+}
+
+void j1939_sock_pending_del(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	/* atomic_dec_return returns the new value */
+	if (!atomic_dec_return(&jsk->skb_pending))
+		wake_up(&jsk->waitq);	/* no pending SKB's */
+}
+
+static void j1939_jsk_add(struct j1939_priv *priv, struct j1939_sock *jsk)
+{
+	jsk->state |= J1939_SOCK_BOUND;
+	j1939_priv_get(priv);
+
+	write_lock_bh(&priv->j1939_socks_lock);
+	list_add_tail(&jsk->list, &priv->j1939_socks);
+	write_unlock_bh(&priv->j1939_socks_lock);
+}
+
+static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
+{
+	write_lock_bh(&priv->j1939_socks_lock);
+	list_del_init(&jsk->list);
+	write_unlock_bh(&priv->j1939_socks_lock);
+
+	j1939_priv_put(priv);
+	jsk->state &= ~J1939_SOCK_BOUND;
+}
+
+static bool j1939_sk_queue_session(struct j1939_session *session)
+{
+	struct j1939_sock *jsk = j1939_sk(session->sk);
+	bool empty;
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	empty = list_empty(&jsk->sk_session_queue);
+	j1939_session_get(session);
+	list_add_tail(&session->sk_session_queue_entry, &jsk->sk_session_queue);
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+	j1939_sock_pending_add(&jsk->sk);
+
+	return empty;
+}
+
+static struct
+j1939_session *j1939_sk_get_incomplete_session(struct j1939_sock *jsk)
+{
+	struct j1939_session *session = NULL;
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	if (!list_empty(&jsk->sk_session_queue)) {
+		session = list_last_entry(&jsk->sk_session_queue,
+					  struct j1939_session,
+					  sk_session_queue_entry);
+		if (session->total_queued_size == session->total_message_size)
+			session = NULL;
+		else
+			j1939_session_get(session);
+	}
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+
+	return session;
+}
+
+static void j1939_sk_queue_drop_all(struct j1939_priv *priv,
+				    struct j1939_sock *jsk, int err)
+{
+	struct j1939_session *session, *tmp;
+
+	netdev_dbg(priv->ndev, "%s: err: %i\n", __func__, err);
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	list_for_each_entry_safe(session, tmp, &jsk->sk_session_queue,
+				 sk_session_queue_entry) {
+		list_del_init(&session->sk_session_queue_entry);
+		session->err = err;
+		j1939_session_put(session);
+	}
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+}
+
+static void j1939_sk_queue_activate_next_locked(struct j1939_session *session)
+{
+	struct j1939_sock *jsk;
+	struct j1939_session *first;
+	int err;
+
+	/* RX-Session don't have a socket (yet) */
+	if (!session->sk)
+		return;
+
+	jsk = j1939_sk(session->sk);
+	lockdep_assert_held(&jsk->sk_session_queue_lock);
+
+	err = session->err;
+
+	first = list_first_entry_or_null(&jsk->sk_session_queue,
+					 struct j1939_session,
+					 sk_session_queue_entry);
+
+	/* Some else has already activated the next session */
+	if (first != session)
+		return;
+
+activate_next:
+	list_del_init(&first->sk_session_queue_entry);
+	j1939_session_put(first);
+	first = list_first_entry_or_null(&jsk->sk_session_queue,
+					 struct j1939_session,
+					 sk_session_queue_entry);
+	if (!first)
+		return;
+
+	if (j1939_session_activate(first)) {
+		netdev_warn_once(first->priv->ndev,
+				 "%s: 0x%p: Identical session is already activated.\n",
+				 __func__, first);
+		first->err = -EBUSY;
+		goto activate_next;
+	} else {
+		/* Give receiver some time (arbitrary chosen) to recover */
+		int time_ms = 0;
+
+		if (err)
+			time_ms = 10 + get_random_u32_below(16);
+
+		j1939_tp_schedule_txtimer(first, time_ms);
+	}
+}
+
+void j1939_sk_queue_activate_next(struct j1939_session *session)
+{
+	struct j1939_sock *jsk;
+
+	if (!session->sk)
+		return;
+
+	jsk = j1939_sk(session->sk);
+
+	spin_lock_bh(&jsk->sk_session_queue_lock);
+	j1939_sk_queue_activate_next_locked(session);
+	spin_unlock_bh(&jsk->sk_session_queue_lock);
+}
+
+static bool j1939_sk_match_dst(struct j1939_sock *jsk,
+			       const struct j1939_sk_buff_cb *skcb)
+{
+	if ((jsk->state & J1939_SOCK_PROMISC))
+		return true;
+
+	/* Destination address filter */
+	if (jsk->addr.src_name && skcb->addr.dst_name) {
+		if (jsk->addr.src_name != skcb->addr.dst_name)
+			return false;
+	} else {
+		/* receive (all sockets) if
+		 * - all packages that match our bind() address
+		 * - all broadcast on a socket if SO_BROADCAST
+		 *   is set
+		 */
+		if (j1939_address_is_unicast(skcb->addr.da)) {
+			if (jsk->addr.sa != skcb->addr.da)
+				return false;
+		} else if (!sock_flag(&jsk->sk, SOCK_BROADCAST)) {
+			/* receiving broadcast without SO_BROADCAST
+			 * flag is not allowed
+			 */
+			return false;
+		}
+	}
+
+	/* Source address filter */
+	if (jsk->state & J1939_SOCK_CONNECTED) {
+		/* receive (all sockets) if
+		 * - all packages that match our connect() name or address
+		 */
+		if (jsk->addr.dst_name && skcb->addr.src_name) {
+			if (jsk->addr.dst_name != skcb->addr.src_name)
+				return false;
+		} else {
+			if (jsk->addr.da != skcb->addr.sa)
+				return false;
+		}
+	}
+
+	/* PGN filter */
+	if (j1939_pgn_is_valid(jsk->pgn_rx_filter) &&
+	    jsk->pgn_rx_filter != skcb->addr.pgn)
+		return false;
+
+	return true;
+}
+
+/* matches skb control buffer (addr) with a j1939 filter */
+static bool j1939_sk_match_filter(struct j1939_sock *jsk,
+				  const struct j1939_sk_buff_cb *skcb)
+{
+	const struct j1939_filter *f;
+	int nfilter;
+
+	spin_lock_bh(&jsk->filters_lock);
+
+	f = jsk->filters;
+	nfilter = jsk->nfilters;
+
+	if (!nfilter)
+		/* receive all when no filters are assigned */
+		goto filter_match_found;
+
+	for (; nfilter; ++f, --nfilter) {
+		if ((skcb->addr.pgn & f->pgn_mask) != f->pgn)
+			continue;
+		if ((skcb->addr.sa & f->addr_mask) != f->addr)
+			continue;
+		if ((skcb->addr.src_name & f->name_mask) != f->name)
+			continue;
+		goto filter_match_found;
+	}
+
+	spin_unlock_bh(&jsk->filters_lock);
+	return false;
+
+filter_match_found:
+	spin_unlock_bh(&jsk->filters_lock);
+	return true;
+}
+
+static bool j1939_sk_recv_match_one(struct j1939_sock *jsk,
+				    const struct j1939_sk_buff_cb *skcb)
+{
+	if (!(jsk->state & J1939_SOCK_BOUND))
+		return false;
+
+	if (!j1939_sk_match_dst(jsk, skcb))
+		return false;
+
+	if (!j1939_sk_match_filter(jsk, skcb))
+		return false;
+
+	return true;
+}
+
+static void j1939_sk_recv_one(struct j1939_sock *jsk, struct sk_buff *oskb)
+{
+	const struct j1939_sk_buff_cb *oskcb = j1939_skb_to_cb(oskb);
+	struct j1939_sk_buff_cb *skcb;
+	enum skb_drop_reason reason;
+	struct sk_buff *skb;
+
+	if (oskb->sk == &jsk->sk)
+		return;
+
+	if (!j1939_sk_recv_match_one(jsk, oskcb))
+		return;
+
+	skb = skb_clone(oskb, GFP_ATOMIC);
+	if (!skb) {
+		pr_warn("skb clone failed\n");
+		return;
+	}
+	can_skb_set_owner(skb, oskb->sk);
+
+	skcb = j1939_skb_to_cb(skb);
+	skcb->msg_flags &= ~(MSG_DONTROUTE);
+	if (skb->sk)
+		skcb->msg_flags |= MSG_DONTROUTE;
+
+	reason = sock_queue_rcv_skb_reason(&jsk->sk, skb);
+	if (reason)
+		sk_skb_reason_drop(&jsk->sk, skb, reason);
+}
+
+bool j1939_sk_recv_match(struct j1939_priv *priv, struct j1939_sk_buff_cb *skcb)
+{
+	struct j1939_sock *jsk;
+	bool match = false;
+
+	read_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		match = j1939_sk_recv_match_one(jsk, skcb);
+		if (match)
+			break;
+	}
+	read_unlock_bh(&priv->j1939_socks_lock);
+
+	return match;
+}
+
+void j1939_sk_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sock *jsk;
+
+	read_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		j1939_sk_recv_one(jsk, skb);
+	}
+	read_unlock_bh(&priv->j1939_socks_lock);
+}
+
+static void j1939_sk_sock_destruct(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	/* This function will be called by the generic networking code, when
+	 * the socket is ultimately closed (sk->sk_destruct).
+	 *
+	 * The race between
+	 * - processing a received CAN frame
+	 *   (can_receive -> j1939_can_recv)
+	 *   and accessing j1939_priv
+	 * ... and ...
+	 * - closing a socket
+	 *   (j1939_can_rx_unregister -> can_rx_unregister)
+	 *   and calling the final j1939_priv_put()
+	 *
+	 * is avoided by calling the final j1939_priv_put() from this
+	 * RCU deferred cleanup call.
+	 */
+	if (jsk->priv) {
+		j1939_priv_put(jsk->priv);
+		jsk->priv = NULL;
+	}
+
+	/* call generic CAN sock destruct */
+	can_sock_destruct(sk);
+}
+
+static int j1939_sk_init(struct sock *sk)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	/* Ensure that "sk" is first member in "struct j1939_sock", so that we
+	 * can skip it during memset().
+	 */
+	BUILD_BUG_ON(offsetof(struct j1939_sock, sk) != 0);
+	memset((void *)jsk + sizeof(jsk->sk), 0x0,
+	       sizeof(*jsk) - sizeof(jsk->sk));
+
+	INIT_LIST_HEAD(&jsk->list);
+	init_waitqueue_head(&jsk->waitq);
+	jsk->sk.sk_priority = j1939_to_sk_priority(6);
+	jsk->sk.sk_reuse = 1; /* per default */
+	jsk->addr.sa = J1939_NO_ADDR;
+	jsk->addr.da = J1939_NO_ADDR;
+	jsk->addr.pgn = J1939_NO_PGN;
+	jsk->pgn_rx_filter = J1939_NO_PGN;
+	atomic_set(&jsk->skb_pending, 0);
+	spin_lock_init(&jsk->sk_session_queue_lock);
+	INIT_LIST_HEAD(&jsk->sk_session_queue);
+	spin_lock_init(&jsk->filters_lock);
+
+	/* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */
+	sock_set_flag(sk, SOCK_RCU_FREE);
+	sk->sk_destruct = j1939_sk_sock_destruct;
+	sk->sk_protocol = CAN_J1939;
+
+	return 0;
+}
+
+static int j1939_sk_sanity_check(struct sockaddr_can *addr, int len)
+{
+	if (!addr)
+		return -EDESTADDRREQ;
+	if (len < J1939_MIN_NAMELEN)
+		return -EINVAL;
+	if (addr->can_family != AF_CAN)
+		return -EINVAL;
+	if (!addr->can_ifindex)
+		return -ENODEV;
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
+	    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int j1939_sk_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct j1939_sock *jsk = j1939_sk(sock->sk);
+	struct j1939_priv *priv;
+	struct sock *sk;
+	struct net *net;
+	int ret = 0;
+
+	ret = j1939_sk_sanity_check(addr, len);
+	if (ret)
+		return ret;
+
+	lock_sock(sock->sk);
+
+	priv = jsk->priv;
+	sk = sock->sk;
+	net = sock_net(sk);
+
+	/* Already bound to an interface? */
+	if (jsk->state & J1939_SOCK_BOUND) {
+		/* A re-bind() to a different interface is not
+		 * supported.
+		 */
+		if (jsk->ifindex != addr->can_ifindex) {
+			ret = -EINVAL;
+			goto out_release_sock;
+		}
+
+		/* drop old references */
+		j1939_jsk_del(priv, jsk);
+		j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
+	} else {
+		struct can_ml_priv *can_ml;
+		struct net_device *ndev;
+
+		ndev = dev_get_by_index(net, addr->can_ifindex);
+		if (!ndev) {
+			ret = -ENODEV;
+			goto out_release_sock;
+		}
+
+		if (ndev->reg_state != NETREG_REGISTERED) {
+			dev_put(ndev);
+			ret = -ENODEV;
+			goto out_release_sock;
+		}
+
+		can_ml = can_get_ml_priv(ndev);
+		if (!can_ml) {
+			dev_put(ndev);
+			ret = -ENODEV;
+			goto out_release_sock;
+		}
+
+		if (!(ndev->flags & IFF_UP)) {
+			dev_put(ndev);
+			ret = -ENETDOWN;
+			goto out_release_sock;
+		}
+
+		priv = j1939_netdev_start(ndev);
+		dev_put(ndev);
+		if (IS_ERR(priv)) {
+			ret = PTR_ERR(priv);
+			goto out_release_sock;
+		}
+
+		jsk->ifindex = addr->can_ifindex;
+
+		/* the corresponding j1939_priv_put() is called via
+		 * sk->sk_destruct, which points to j1939_sk_sock_destruct()
+		 */
+		j1939_priv_get(priv);
+		jsk->priv = priv;
+	}
+
+	/* set default transmit pgn */
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+		jsk->pgn_rx_filter = addr->can_addr.j1939.pgn;
+	jsk->addr.src_name = addr->can_addr.j1939.name;
+	jsk->addr.sa = addr->can_addr.j1939.addr;
+
+	/* get new references */
+	ret = j1939_local_ecu_get(priv, jsk->addr.src_name, jsk->addr.sa);
+	if (ret) {
+		j1939_netdev_stop(priv);
+		jsk->priv = NULL;
+		synchronize_rcu();
+		j1939_priv_put(priv);
+		goto out_release_sock;
+	}
+
+	j1939_jsk_add(priv, jsk);
+
+ out_release_sock: /* fall through */
+	release_sock(sock->sk);
+
+	return ret;
+}
+
+static int j1939_sk_connect(struct socket *sock, struct sockaddr_unsized *uaddr,
+			    int len, int flags)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct j1939_sock *jsk = j1939_sk(sock->sk);
+	int ret = 0;
+
+	ret = j1939_sk_sanity_check(addr, len);
+	if (ret)
+		return ret;
+
+	lock_sock(sock->sk);
+
+	/* bind() before connect() is mandatory */
+	if (!(jsk->state & J1939_SOCK_BOUND)) {
+		ret = -EINVAL;
+		goto out_release_sock;
+	}
+
+	/* A connect() to a different interface is not supported. */
+	if (jsk->ifindex != addr->can_ifindex) {
+		ret = -EINVAL;
+		goto out_release_sock;
+	}
+
+	if (!addr->can_addr.j1939.name &&
+	    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
+	    !sock_flag(&jsk->sk, SOCK_BROADCAST)) {
+		/* broadcast, but SO_BROADCAST not set */
+		ret = -EACCES;
+		goto out_release_sock;
+	}
+
+	jsk->addr.dst_name = addr->can_addr.j1939.name;
+	jsk->addr.da = addr->can_addr.j1939.addr;
+
+	if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+		jsk->addr.pgn = addr->can_addr.j1939.pgn;
+
+	jsk->state |= J1939_SOCK_CONNECTED;
+
+ out_release_sock: /* fall through */
+	release_sock(sock->sk);
+
+	return ret;
+}
+
+static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr,
+				       const struct j1939_sock *jsk, int peer)
+{
+	/* There are two holes (2 bytes and 3 bytes) to clear to avoid
+	 * leaking kernel information to user space.
+	 */
+	memset(addr, 0, J1939_MIN_NAMELEN);
+
+	addr->can_family = AF_CAN;
+	addr->can_ifindex = jsk->ifindex;
+	addr->can_addr.j1939.pgn = jsk->addr.pgn;
+	if (peer) {
+		addr->can_addr.j1939.name = jsk->addr.dst_name;
+		addr->can_addr.j1939.addr = jsk->addr.da;
+	} else {
+		addr->can_addr.j1939.name = jsk->addr.src_name;
+		addr->can_addr.j1939.addr = jsk->addr.sa;
+	}
+}
+
+static int j1939_sk_getname(struct socket *sock, struct sockaddr *uaddr,
+			    int peer)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int ret = 0;
+
+	lock_sock(sk);
+
+	if (peer && !(jsk->state & J1939_SOCK_CONNECTED)) {
+		ret = -EADDRNOTAVAIL;
+		goto failure;
+	}
+
+	j1939_sk_sock2sockaddr_can(addr, jsk, peer);
+	ret = J1939_MIN_NAMELEN;
+
+ failure:
+	release_sock(sk);
+
+	return ret;
+}
+
+static int j1939_sk_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk;
+
+	if (!sk)
+		return 0;
+
+	lock_sock(sk);
+	jsk = j1939_sk(sk);
+
+	if (jsk->state & J1939_SOCK_BOUND) {
+		struct j1939_priv *priv = jsk->priv;
+
+		if (wait_event_interruptible(jsk->waitq,
+					     !j1939_sock_pending_get(&jsk->sk))) {
+			j1939_cancel_active_session(priv, sk);
+			j1939_sk_queue_drop_all(priv, jsk, ESHUTDOWN);
+		}
+
+		j1939_jsk_del(priv, jsk);
+
+		j1939_local_ecu_put(priv, jsk->addr.src_name,
+				    jsk->addr.sa);
+
+		j1939_netdev_stop(priv);
+	}
+
+	kfree(jsk->filters);
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int j1939_sk_setsockopt_flag(struct j1939_sock *jsk, sockptr_t optval,
+				    unsigned int optlen, int flag)
+{
+	int tmp;
+
+	if (optlen != sizeof(tmp))
+		return -EINVAL;
+	if (copy_from_sockptr(&tmp, optval, optlen))
+		return -EFAULT;
+	lock_sock(&jsk->sk);
+	if (tmp)
+		jsk->state |= flag;
+	else
+		jsk->state &= ~flag;
+	release_sock(&jsk->sk);
+	return tmp;
+}
+
+static int j1939_sk_setsockopt(struct socket *sock, int level, int optname,
+			       sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int tmp, count = 0, ret = 0;
+	struct j1939_filter *filters = NULL, *ofilters;
+
+	if (level != SOL_CAN_J1939)
+		return -EINVAL;
+
+	switch (optname) {
+	case SO_J1939_FILTER:
+		if (!sockptr_is_null(optval) && optlen != 0) {
+			struct j1939_filter *f;
+			int c;
+
+			if (optlen % sizeof(*filters) != 0)
+				return -EINVAL;
+
+			if (optlen > J1939_FILTER_MAX *
+			    sizeof(struct j1939_filter))
+				return -EINVAL;
+
+			count = optlen / sizeof(*filters);
+			filters = memdup_sockptr(optval, optlen);
+			if (IS_ERR(filters))
+				return PTR_ERR(filters);
+
+			for (f = filters, c = count; c; f++, c--) {
+				f->name &= f->name_mask;
+				f->pgn &= f->pgn_mask;
+				f->addr &= f->addr_mask;
+			}
+		}
+
+		lock_sock(&jsk->sk);
+		spin_lock_bh(&jsk->filters_lock);
+		ofilters = jsk->filters;
+		jsk->filters = filters;
+		jsk->nfilters = count;
+		spin_unlock_bh(&jsk->filters_lock);
+		release_sock(&jsk->sk);
+		kfree(ofilters);
+		return 0;
+	case SO_J1939_PROMISC:
+		return j1939_sk_setsockopt_flag(jsk, optval, optlen,
+						J1939_SOCK_PROMISC);
+	case SO_J1939_ERRQUEUE:
+		ret = j1939_sk_setsockopt_flag(jsk, optval, optlen,
+					       J1939_SOCK_ERRQUEUE);
+		if (ret < 0)
+			return ret;
+
+		if (!(jsk->state & J1939_SOCK_ERRQUEUE))
+			skb_queue_purge(&sk->sk_error_queue);
+		return ret;
+	case SO_J1939_SEND_PRIO:
+		if (optlen != sizeof(tmp))
+			return -EINVAL;
+		if (copy_from_sockptr(&tmp, optval, optlen))
+			return -EFAULT;
+		if (tmp < 0 || tmp > 7)
+			return -EDOM;
+		if (tmp < 2 && !capable(CAP_NET_ADMIN))
+			return -EPERM;
+		lock_sock(&jsk->sk);
+		jsk->sk.sk_priority = j1939_to_sk_priority(tmp);
+		release_sock(&jsk->sk);
+		return 0;
+	default:
+		return -ENOPROTOOPT;
+	}
+}
+
+static int j1939_sk_getsockopt(struct socket *sock, int level, int optname,
+			       char __user *optval, int __user *optlen)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	int ret, ulen;
+	/* set defaults for using 'int' properties */
+	int tmp = 0;
+	int len = sizeof(tmp);
+	void *val = &tmp;
+
+	if (level != SOL_CAN_J1939)
+		return -EINVAL;
+	if (get_user(ulen, optlen))
+		return -EFAULT;
+	if (ulen < 0)
+		return -EINVAL;
+
+	lock_sock(&jsk->sk);
+	switch (optname) {
+	case SO_J1939_PROMISC:
+		tmp = (jsk->state & J1939_SOCK_PROMISC) ? 1 : 0;
+		break;
+	case SO_J1939_ERRQUEUE:
+		tmp = (jsk->state & J1939_SOCK_ERRQUEUE) ? 1 : 0;
+		break;
+	case SO_J1939_SEND_PRIO:
+		tmp = j1939_prio(jsk->sk.sk_priority);
+		break;
+	default:
+		ret = -ENOPROTOOPT;
+		goto no_copy;
+	}
+
+	/* copy to user, based on 'len' & 'val'
+	 * but most sockopt's are 'int' properties, and have 'len' & 'val'
+	 * left unchanged, but instead modified 'tmp'
+	 */
+	if (len > ulen)
+		ret = -EFAULT;
+	else if (put_user(len, optlen))
+		ret = -EFAULT;
+	else if (copy_to_user(optval, val, len))
+		ret = -EFAULT;
+	else
+		ret = 0;
+ no_copy:
+	release_sock(&jsk->sk);
+	return ret;
+}
+
+static int j1939_sk_recvmsg(struct socket *sock, struct msghdr *msg,
+			    size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	struct j1939_sk_buff_cb *skcb;
+	int ret = 0;
+
+	if (flags & ~(MSG_DONTWAIT | MSG_ERRQUEUE | MSG_CMSG_COMPAT))
+		return -EINVAL;
+
+	if (flags & MSG_ERRQUEUE)
+		return sock_recv_errqueue(sock->sk, msg, size, SOL_CAN_J1939,
+					  SCM_J1939_ERRQUEUE);
+
+	skb = skb_recv_datagram(sk, flags, &ret);
+	if (!skb)
+		return ret;
+
+	if (size < skb->len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		size = skb->len;
+
+	ret = memcpy_to_msg(msg, skb->data, size);
+	if (ret < 0) {
+		skb_free_datagram(sk, skb);
+		return ret;
+	}
+
+	skcb = j1939_skb_to_cb(skb);
+	if (j1939_address_is_valid(skcb->addr.da))
+		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_ADDR,
+			 sizeof(skcb->addr.da), &skcb->addr.da);
+
+	if (skcb->addr.dst_name)
+		put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_DEST_NAME,
+			 sizeof(skcb->addr.dst_name), &skcb->addr.dst_name);
+
+	put_cmsg(msg, SOL_CAN_J1939, SCM_J1939_PRIO,
+		 sizeof(skcb->priority), &skcb->priority);
+
+	if (msg->msg_name) {
+		struct sockaddr_can *paddr = msg->msg_name;
+
+		msg->msg_namelen = J1939_MIN_NAMELEN;
+		memset(msg->msg_name, 0, msg->msg_namelen);
+		paddr->can_family = AF_CAN;
+		paddr->can_ifindex = skb->skb_iif;
+		paddr->can_addr.j1939.name = skcb->addr.src_name;
+		paddr->can_addr.j1939.addr = skcb->addr.sa;
+		paddr->can_addr.j1939.pgn = skcb->addr.pgn;
+	}
+
+	sock_recv_cmsgs(msg, sk, skb);
+	msg->msg_flags |= skcb->msg_flags;
+	skb_free_datagram(sk, skb);
+
+	return size;
+}
+
+static struct sk_buff *j1939_sk_alloc_skb(struct net_device *ndev,
+					  struct sock *sk,
+					  struct msghdr *msg, size_t size,
+					  int *errcode)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_sk_buff_cb *skcb;
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	int ret;
+
+	skb = sock_alloc_send_skb(sk,
+				  size +
+				  sizeof(struct can_frame) -
+				  sizeof(((struct can_frame *)NULL)->data),
+				  msg->msg_flags & MSG_DONTWAIT, &ret);
+	if (!skb)
+		goto failure;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		ret = -ENOMEM;
+		goto failure;
+	}
+
+	csx->can_iif = ndev->ifindex;
+	skb_reserve(skb, offsetof(struct can_frame, data));
+
+	ret = memcpy_from_msg(skb_put(skb, size), msg, size);
+	if (ret < 0)
+		goto free_skb;
+
+	skb->dev = ndev;
+
+	skcb = j1939_skb_to_cb(skb);
+	memset(skcb, 0, sizeof(*skcb));
+	skcb->addr = jsk->addr;
+	skcb->priority = j1939_prio(READ_ONCE(sk->sk_priority));
+
+	if (msg->msg_name) {
+		struct sockaddr_can *addr = msg->msg_name;
+
+		if (addr->can_addr.j1939.name ||
+		    addr->can_addr.j1939.addr != J1939_NO_ADDR) {
+			skcb->addr.dst_name = addr->can_addr.j1939.name;
+			skcb->addr.da = addr->can_addr.j1939.addr;
+		}
+		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn))
+			skcb->addr.pgn = addr->can_addr.j1939.pgn;
+	}
+
+	*errcode = ret;
+	return skb;
+
+free_skb:
+	kfree_skb(skb);
+failure:
+	*errcode = ret;
+	return NULL;
+}
+
+static size_t j1939_sk_opt_stats_get_size(enum j1939_sk_errqueue_type type)
+{
+	switch (type) {
+	case J1939_ERRQUEUE_RX_RTS:
+		return
+			nla_total_size(sizeof(u32)) + /* J1939_NLA_TOTAL_SIZE */
+			nla_total_size(sizeof(u32)) + /* J1939_NLA_PGN */
+			nla_total_size(sizeof(u64)) + /* J1939_NLA_SRC_NAME */
+			nla_total_size(sizeof(u64)) + /* J1939_NLA_DEST_NAME */
+			nla_total_size(sizeof(u8)) +  /* J1939_NLA_SRC_ADDR */
+			nla_total_size(sizeof(u8)) +  /* J1939_NLA_DEST_ADDR */
+			0;
+	default:
+		return
+			nla_total_size(sizeof(u32)) + /* J1939_NLA_BYTES_ACKED */
+			0;
+	}
+}
+
+static struct sk_buff *
+j1939_sk_get_timestamping_opt_stats(struct j1939_session *session,
+				    enum j1939_sk_errqueue_type type)
+{
+	struct sk_buff *stats;
+	u32 size;
+
+	stats = alloc_skb(j1939_sk_opt_stats_get_size(type), GFP_ATOMIC);
+	if (!stats)
+		return NULL;
+
+	if (session->skcb.addr.type == J1939_SIMPLE)
+		size = session->total_message_size;
+	else
+		size = min(session->pkt.tx_acked * 7,
+			   session->total_message_size);
+
+	switch (type) {
+	case J1939_ERRQUEUE_RX_RTS:
+		nla_put_u32(stats, J1939_NLA_TOTAL_SIZE,
+			    session->total_message_size);
+		nla_put_u32(stats, J1939_NLA_PGN,
+			    session->skcb.addr.pgn);
+		nla_put_u64_64bit(stats, J1939_NLA_SRC_NAME,
+				  session->skcb.addr.src_name, J1939_NLA_PAD);
+		nla_put_u64_64bit(stats, J1939_NLA_DEST_NAME,
+				  session->skcb.addr.dst_name, J1939_NLA_PAD);
+		nla_put_u8(stats, J1939_NLA_SRC_ADDR,
+			   session->skcb.addr.sa);
+		nla_put_u8(stats, J1939_NLA_DEST_ADDR,
+			   session->skcb.addr.da);
+		break;
+	default:
+		nla_put_u32(stats, J1939_NLA_BYTES_ACKED, size);
+	}
+
+	return stats;
+}
+
+static void __j1939_sk_errqueue(struct j1939_session *session, struct sock *sk,
+				enum j1939_sk_errqueue_type type)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sock *jsk;
+	struct sock_exterr_skb *serr;
+	struct sk_buff *skb;
+	char *state = "UNK";
+	u32 tsflags;
+	int err;
+
+	jsk = j1939_sk(sk);
+
+	if (!(jsk->state & J1939_SOCK_ERRQUEUE))
+		return;
+
+	tsflags = READ_ONCE(sk->sk_tsflags);
+	switch (type) {
+	case J1939_ERRQUEUE_TX_ACK:
+		if (!(tsflags & SOF_TIMESTAMPING_TX_ACK))
+			return;
+		break;
+	case J1939_ERRQUEUE_TX_SCHED:
+		if (!(tsflags & SOF_TIMESTAMPING_TX_SCHED))
+			return;
+		break;
+	case J1939_ERRQUEUE_TX_ABORT:
+		break;
+	case J1939_ERRQUEUE_RX_RTS:
+		fallthrough;
+	case J1939_ERRQUEUE_RX_DPO:
+		fallthrough;
+	case J1939_ERRQUEUE_RX_ABORT:
+		if (!(tsflags & SOF_TIMESTAMPING_RX_SOFTWARE))
+			return;
+		break;
+	default:
+		netdev_err(priv->ndev, "Unknown errqueue type %i\n", type);
+	}
+
+	skb = j1939_sk_get_timestamping_opt_stats(session, type);
+	if (!skb)
+		return;
+
+	skb->tstamp = ktime_get_real();
+
+	BUILD_BUG_ON(sizeof(struct sock_exterr_skb) > sizeof(skb->cb));
+
+	serr = SKB_EXT_ERR(skb);
+	memset(serr, 0, sizeof(*serr));
+	switch (type) {
+	case J1939_ERRQUEUE_TX_ACK:
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
+		serr->ee.ee_info = SCM_TSTAMP_ACK;
+		state = "TX ACK";
+		break;
+	case J1939_ERRQUEUE_TX_SCHED:
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
+		serr->ee.ee_info = SCM_TSTAMP_SCHED;
+		state = "TX SCH";
+		break;
+	case J1939_ERRQUEUE_TX_ABORT:
+		serr->ee.ee_errno = session->err;
+		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+		serr->ee.ee_info = J1939_EE_INFO_TX_ABORT;
+		state = "TX ABT";
+		break;
+	case J1939_ERRQUEUE_RX_RTS:
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+		serr->ee.ee_info = J1939_EE_INFO_RX_RTS;
+		state = "RX RTS";
+		break;
+	case J1939_ERRQUEUE_RX_DPO:
+		serr->ee.ee_errno = ENOMSG;
+		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+		serr->ee.ee_info = J1939_EE_INFO_RX_DPO;
+		state = "RX DPO";
+		break;
+	case J1939_ERRQUEUE_RX_ABORT:
+		serr->ee.ee_errno = session->err;
+		serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+		serr->ee.ee_info = J1939_EE_INFO_RX_ABORT;
+		state = "RX ABT";
+		break;
+	}
+
+	serr->opt_stats = true;
+	if (tsflags & SOF_TIMESTAMPING_OPT_ID)
+		serr->ee.ee_data = session->tskey;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p tskey: %i, state: %s\n",
+		   __func__, session, session->tskey, state);
+	err = sock_queue_err_skb(sk, skb);
+
+	if (err)
+		kfree_skb(skb);
+};
+
+void j1939_sk_errqueue(struct j1939_session *session,
+		       enum j1939_sk_errqueue_type type)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sock *jsk;
+
+	if (session->sk) {
+		/* send TX notifications to the socket of origin  */
+		__j1939_sk_errqueue(session, session->sk, type);
+		return;
+	}
+
+	/* spread RX notifications to all sockets subscribed to this session */
+	read_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		if (j1939_sk_recv_match_one(jsk, &session->skcb))
+			__j1939_sk_errqueue(session, &jsk->sk, type);
+	}
+	read_unlock_bh(&priv->j1939_socks_lock);
+};
+
+void j1939_sk_send_loop_abort(struct sock *sk, int err)
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+
+	if (jsk->state & J1939_SOCK_ERRQUEUE)
+		return;
+
+	sk->sk_err = err;
+
+	sk_error_report(sk);
+}
+
+static int j1939_sk_send_loop(struct j1939_priv *priv,  struct sock *sk,
+			      struct msghdr *msg, size_t size)
+
+{
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_session *session = j1939_sk_get_incomplete_session(jsk);
+	struct sk_buff *skb;
+	size_t segment_size, todo_size;
+	int ret = 0;
+
+	if (session &&
+	    session->total_message_size != session->total_queued_size + size) {
+		j1939_session_put(session);
+		return -EIO;
+	}
+
+	todo_size = size;
+
+	do {
+		struct j1939_sk_buff_cb *skcb;
+
+		segment_size = min_t(size_t, J1939_MAX_TP_PACKET_SIZE,
+				     todo_size);
+
+		/* Allocate skb for one segment */
+		skb = j1939_sk_alloc_skb(priv->ndev, sk, msg, segment_size,
+					 &ret);
+		if (ret)
+			break;
+
+		skcb = j1939_skb_to_cb(skb);
+
+		if (!session) {
+			/* at this point the size should be full size
+			 * of the session
+			 */
+			skcb->offset = 0;
+			session = j1939_tp_send(priv, skb, size);
+			if (IS_ERR(session)) {
+				ret = PTR_ERR(session);
+				goto kfree_skb;
+			}
+			if (j1939_sk_queue_session(session)) {
+				/* try to activate session if we a
+				 * fist in the queue
+				 */
+				if (!j1939_session_activate(session)) {
+					j1939_tp_schedule_txtimer(session, 0);
+				} else {
+					ret = -EBUSY;
+					session->err = ret;
+					j1939_sk_queue_drop_all(priv, jsk,
+								EBUSY);
+					break;
+				}
+			}
+		} else {
+			skcb->offset = session->total_queued_size;
+			j1939_session_skb_queue(session, skb);
+		}
+
+		todo_size -= segment_size;
+		session->total_queued_size += segment_size;
+	} while (todo_size);
+
+	switch (ret) {
+	case 0: /* OK */
+		if (todo_size)
+			netdev_warn(priv->ndev,
+				    "no error found and not completely queued?! %zu\n",
+				    todo_size);
+		ret = size;
+		break;
+	case -ERESTARTSYS:
+		ret = -EINTR;
+		fallthrough;
+	case -EAGAIN: /* OK */
+		if (todo_size != size)
+			ret = size - todo_size;
+		break;
+	default: /* ERROR */
+		break;
+	}
+
+	if (session)
+		j1939_session_put(session);
+
+	return ret;
+
+ kfree_skb:
+	kfree_skb(skb);
+	return ret;
+}
+
+static int j1939_sk_sendmsg(struct socket *sock, struct msghdr *msg,
+			    size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct j1939_sock *jsk = j1939_sk(sk);
+	struct j1939_priv *priv;
+	int ifindex;
+	int ret;
+
+	lock_sock(sock->sk);
+	/* various socket state tests */
+	if (!(jsk->state & J1939_SOCK_BOUND)) {
+		ret = -EBADFD;
+		goto sendmsg_done;
+	}
+
+	priv = jsk->priv;
+	ifindex = jsk->ifindex;
+
+	if (!jsk->addr.src_name && jsk->addr.sa == J1939_NO_ADDR) {
+		/* no source address assigned yet */
+		ret = -EBADFD;
+		goto sendmsg_done;
+	}
+
+	/* deal with provided destination address info */
+	if (msg->msg_name) {
+		struct sockaddr_can *addr = msg->msg_name;
+
+		if (msg->msg_namelen < J1939_MIN_NAMELEN) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
+
+		if (addr->can_family != AF_CAN) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
+
+		if (addr->can_ifindex && addr->can_ifindex != ifindex) {
+			ret = -EBADFD;
+			goto sendmsg_done;
+		}
+
+		if (j1939_pgn_is_valid(addr->can_addr.j1939.pgn) &&
+		    !j1939_pgn_is_clean_pdu(addr->can_addr.j1939.pgn)) {
+			ret = -EINVAL;
+			goto sendmsg_done;
+		}
+
+		if (!addr->can_addr.j1939.name &&
+		    addr->can_addr.j1939.addr == J1939_NO_ADDR &&
+		    !sock_flag(sk, SOCK_BROADCAST)) {
+			/* broadcast, but SO_BROADCAST not set */
+			ret = -EACCES;
+			goto sendmsg_done;
+		}
+	} else {
+		if (!jsk->addr.dst_name && jsk->addr.da == J1939_NO_ADDR &&
+		    !sock_flag(sk, SOCK_BROADCAST)) {
+			/* broadcast, but SO_BROADCAST not set */
+			ret = -EACCES;
+			goto sendmsg_done;
+		}
+	}
+
+	ret = j1939_sk_send_loop(priv, sk, msg, size);
+
+sendmsg_done:
+	release_sock(sock->sk);
+
+	return ret;
+}
+
+void j1939_sk_netdev_event_netdown(struct j1939_priv *priv)
+{
+	struct j1939_sock *jsk;
+	int error_code = ENETDOWN;
+
+	read_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		jsk->sk.sk_err = error_code;
+		if (!sock_flag(&jsk->sk, SOCK_DEAD))
+			sk_error_report(&jsk->sk);
+
+		j1939_sk_queue_drop_all(priv, jsk, error_code);
+	}
+	read_unlock_bh(&priv->j1939_socks_lock);
+}
+
+void j1939_sk_netdev_event_unregister(struct j1939_priv *priv)
+{
+	struct sock *sk;
+	struct j1939_sock *jsk;
+	bool wait_rcu = false;
+
+rescan: /* The caller is holding a ref on this "priv" via j1939_priv_get_by_ndev(). */
+	read_lock_bh(&priv->j1939_socks_lock);
+	list_for_each_entry(jsk, &priv->j1939_socks, list) {
+		/* Skip if j1939_jsk_add() is not called on this socket. */
+		if (!(jsk->state & J1939_SOCK_BOUND))
+			continue;
+		sk = &jsk->sk;
+		sock_hold(sk);
+		read_unlock_bh(&priv->j1939_socks_lock);
+		/* Check if j1939_jsk_del() is not yet called on this socket after holding
+		 * socket's lock, for both j1939_sk_bind() and j1939_sk_release() call
+		 * j1939_jsk_del() with socket's lock held.
+		 */
+		lock_sock(sk);
+		if (jsk->state & J1939_SOCK_BOUND) {
+			/* Neither j1939_sk_bind() nor j1939_sk_release() called j1939_jsk_del().
+			 * Make this socket no longer bound, by pretending as if j1939_sk_bind()
+			 * dropped old references but did not get new references.
+			 */
+			j1939_jsk_del(priv, jsk);
+			j1939_local_ecu_put(priv, jsk->addr.src_name, jsk->addr.sa);
+			j1939_netdev_stop(priv);
+			/* Call j1939_priv_put() now and prevent j1939_sk_sock_destruct() from
+			 * calling the corresponding j1939_priv_put().
+			 *
+			 * j1939_sk_sock_destruct() is supposed to call j1939_priv_put() after
+			 * an RCU grace period. But since the caller is holding a ref on this
+			 * "priv", we can defer synchronize_rcu() until immediately before
+			 * the caller calls j1939_priv_put().
+			 */
+			j1939_priv_put(priv);
+			jsk->priv = NULL;
+			wait_rcu = true;
+		}
+		release_sock(sk);
+		sock_put(sk);
+		goto rescan;
+	}
+	read_unlock_bh(&priv->j1939_socks_lock);
+	if (wait_rcu)
+		synchronize_rcu();
+}
+
+static int j1939_sk_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+				unsigned long arg)
+{
+	/* no ioctls for socket layer -> hand it down to NIC layer */
+	return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops j1939_ops = {
+	.family = PF_CAN,
+	.release = j1939_sk_release,
+	.bind = j1939_sk_bind,
+	.connect = j1939_sk_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = j1939_sk_getname,
+	.poll = datagram_poll,
+	.ioctl = j1939_sk_no_ioctlcmd,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = j1939_sk_setsockopt,
+	.getsockopt = j1939_sk_getsockopt,
+	.sendmsg = j1939_sk_sendmsg,
+	.recvmsg = j1939_sk_recvmsg,
+	.mmap = sock_no_mmap,
+};
+
+static struct proto j1939_proto __read_mostly = {
+	.name = "CAN_J1939",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct j1939_sock),
+	.init = j1939_sk_init,
+};
+
+const struct can_proto j1939_can_proto = {
+	.type = SOCK_DGRAM,
+	.protocol = CAN_J1939,
+	.ops = &j1939_ops,
+	.prot = &j1939_proto,
+};
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
new file mode 100644
index 000000000..8fcfd13e5
--- /dev/null
+++ b/net/can/j1939/transport.c
@@ -0,0 +1,2263 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2010-2011 EIA Electronics,
+//                         Kurt Van Dijck <kurt.van.dijck@eia.be>
+// Copyright (c) 2018 Protonic,
+//                         Robin van der Gracht <robin@protonic.nl>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Marc Kleine-Budde <kernel@pengutronix.de>
+// Copyright (c) 2017-2019 Pengutronix,
+//                         Oleksij Rempel <kernel@pengutronix.de>
+
+#include <linux/can/skb.h>
+#include <net/can.h>
+
+#include "j1939-priv.h"
+
+#define J1939_XTP_TX_RETRY_LIMIT 100
+
+#define J1939_ETP_PGN_CTL 0xc800
+#define J1939_ETP_PGN_DAT 0xc700
+#define J1939_TP_PGN_CTL 0xec00
+#define J1939_TP_PGN_DAT 0xeb00
+
+#define J1939_TP_CMD_RTS 0x10
+#define J1939_TP_CMD_CTS 0x11
+#define J1939_TP_CMD_EOMA 0x13
+#define J1939_TP_CMD_BAM 0x20
+#define J1939_TP_CMD_ABORT 0xff
+
+#define J1939_ETP_CMD_RTS 0x14
+#define J1939_ETP_CMD_CTS 0x15
+#define J1939_ETP_CMD_DPO 0x16
+#define J1939_ETP_CMD_EOMA 0x17
+#define J1939_ETP_CMD_ABORT 0xff
+
+enum j1939_xtp_abort {
+	J1939_XTP_NO_ABORT = 0,
+	J1939_XTP_ABORT_BUSY = 1,
+	/* Already in one or more connection managed sessions and
+	 * cannot support another.
+	 *
+	 * EALREADY:
+	 * Operation already in progress
+	 */
+
+	J1939_XTP_ABORT_RESOURCE = 2,
+	/* System resources were needed for another task so this
+	 * connection managed session was terminated.
+	 *
+	 * EMSGSIZE:
+	 * The socket type requires that message be sent atomically,
+	 * and the size of the message to be sent made this
+	 * impossible.
+	 */
+
+	J1939_XTP_ABORT_TIMEOUT = 3,
+	/* A timeout occurred and this is the connection abort to
+	 * close the session.
+	 *
+	 * EHOSTUNREACH:
+	 * The destination host cannot be reached (probably because
+	 * the host is down or a remote router cannot reach it).
+	 */
+
+	J1939_XTP_ABORT_GENERIC = 4,
+	/* CTS messages received when data transfer is in progress
+	 *
+	 * EBADMSG:
+	 * Not a data message
+	 */
+
+	J1939_XTP_ABORT_FAULT = 5,
+	/* Maximal retransmit request limit reached
+	 *
+	 * ENOTRECOVERABLE:
+	 * State not recoverable
+	 */
+
+	J1939_XTP_ABORT_UNEXPECTED_DATA = 6,
+	/* Unexpected data transfer packet
+	 *
+	 * ENOTCONN:
+	 * Transport endpoint is not connected
+	 */
+
+	J1939_XTP_ABORT_BAD_SEQ = 7,
+	/* Bad sequence number (and software is not able to recover)
+	 *
+	 * EILSEQ:
+	 * Illegal byte sequence
+	 */
+
+	J1939_XTP_ABORT_DUP_SEQ = 8,
+	/* Duplicate sequence number (and software is not able to
+	 * recover)
+	 */
+
+	J1939_XTP_ABORT_EDPO_UNEXPECTED = 9,
+	/* Unexpected EDPO packet (ETP) or Message size > 1785 bytes
+	 * (TP)
+	 */
+
+	J1939_XTP_ABORT_BAD_EDPO_PGN = 10,
+	/* Unexpected EDPO PGN (PGN in EDPO is bad) */
+
+	J1939_XTP_ABORT_EDPO_OUTOF_CTS = 11,
+	/* EDPO number of packets is greater than CTS */
+
+	J1939_XTP_ABORT_BAD_EDPO_OFFSET = 12,
+	/* Bad EDPO offset */
+
+	J1939_XTP_ABORT_OTHER_DEPRECATED = 13,
+	/* Deprecated. Use 250 instead (Any other reason)  */
+
+	J1939_XTP_ABORT_ECTS_UNXPECTED_PGN = 14,
+	/* Unexpected ECTS PGN (PGN in ECTS is bad) */
+
+	J1939_XTP_ABORT_ECTS_TOO_BIG = 15,
+	/* ECTS requested packets exceeds message size */
+
+	J1939_XTP_ABORT_OTHER = 250,
+	/* Any other reason (if a Connection Abort reason is
+	 * identified that is not listed in the table use code 250)
+	 */
+};
+
+static unsigned int j1939_tp_block = 255;
+static unsigned int j1939_tp_packet_delay;
+static unsigned int j1939_tp_padding = 1;
+
+/* helpers */
+static const char *j1939_xtp_abort_to_str(enum j1939_xtp_abort abort)
+{
+	switch (abort) {
+	case J1939_XTP_ABORT_BUSY:
+		return "Already in one or more connection managed sessions and cannot support another.";
+	case J1939_XTP_ABORT_RESOURCE:
+		return "System resources were needed for another task so this connection managed session was terminated.";
+	case J1939_XTP_ABORT_TIMEOUT:
+		return "A timeout occurred and this is the connection abort to close the session.";
+	case J1939_XTP_ABORT_GENERIC:
+		return "CTS messages received when data transfer is in progress";
+	case J1939_XTP_ABORT_FAULT:
+		return "Maximal retransmit request limit reached";
+	case J1939_XTP_ABORT_UNEXPECTED_DATA:
+		return "Unexpected data transfer packet";
+	case J1939_XTP_ABORT_BAD_SEQ:
+		return "Bad sequence number (and software is not able to recover)";
+	case J1939_XTP_ABORT_DUP_SEQ:
+		return "Duplicate sequence number (and software is not able to recover)";
+	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
+		return "Unexpected EDPO packet (ETP) or Message size > 1785 bytes (TP)";
+	case J1939_XTP_ABORT_BAD_EDPO_PGN:
+		return "Unexpected EDPO PGN (PGN in EDPO is bad)";
+	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
+		return "EDPO number of packets is greater than CTS";
+	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
+		return "Bad EDPO offset";
+	case J1939_XTP_ABORT_OTHER_DEPRECATED:
+		return "Deprecated. Use 250 instead (Any other reason)";
+	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
+		return "Unexpected ECTS PGN (PGN in ECTS is bad)";
+	case J1939_XTP_ABORT_ECTS_TOO_BIG:
+		return "ECTS requested packets exceeds message size";
+	case J1939_XTP_ABORT_OTHER:
+		return "Any other reason (if a Connection Abort reason is identified that is not listed in the table use code 250)";
+	default:
+		return "<unknown>";
+	}
+}
+
+static int j1939_xtp_abort_to_errno(struct j1939_priv *priv,
+				    enum j1939_xtp_abort abort)
+{
+	int err;
+
+	switch (abort) {
+	case J1939_XTP_NO_ABORT:
+		WARN_ON_ONCE(abort == J1939_XTP_NO_ABORT);
+		err = 0;
+		break;
+	case J1939_XTP_ABORT_BUSY:
+		err = EALREADY;
+		break;
+	case J1939_XTP_ABORT_RESOURCE:
+		err = EMSGSIZE;
+		break;
+	case J1939_XTP_ABORT_TIMEOUT:
+		err = EHOSTUNREACH;
+		break;
+	case J1939_XTP_ABORT_GENERIC:
+		err = EBADMSG;
+		break;
+	case J1939_XTP_ABORT_FAULT:
+		err = ENOTRECOVERABLE;
+		break;
+	case J1939_XTP_ABORT_UNEXPECTED_DATA:
+		err = ENOTCONN;
+		break;
+	case J1939_XTP_ABORT_BAD_SEQ:
+		err = EILSEQ;
+		break;
+	case J1939_XTP_ABORT_DUP_SEQ:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_EDPO_UNEXPECTED:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_BAD_EDPO_PGN:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_OTHER_DEPRECATED:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_ECTS_TOO_BIG:
+		err = EPROTO;
+		break;
+	case J1939_XTP_ABORT_OTHER:
+		err = EPROTO;
+		break;
+	default:
+		netdev_warn(priv->ndev, "Unknown abort code %i", abort);
+		err = EPROTO;
+	}
+
+	return err;
+}
+
+static inline void j1939_session_list_lock(struct j1939_priv *priv)
+{
+	spin_lock_bh(&priv->active_session_list_lock);
+}
+
+static inline void j1939_session_list_unlock(struct j1939_priv *priv)
+{
+	spin_unlock_bh(&priv->active_session_list_lock);
+}
+
+void j1939_session_get(struct j1939_session *session)
+{
+	kref_get(&session->kref);
+}
+
+/* session completion functions */
+static void __j1939_session_drop(struct j1939_session *session)
+{
+	if (!session->transmission)
+		return;
+
+	j1939_sock_pending_del(session->sk);
+	sock_put(session->sk);
+}
+
+static void j1939_session_destroy(struct j1939_session *session)
+{
+	struct sk_buff *skb;
+
+	if (session->transmission) {
+		if (session->err)
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT);
+		else
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ACK);
+	} else if (session->err) {
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
+	}
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
+	WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
+
+	while ((skb = skb_dequeue(&session->skb_queue)) != NULL) {
+		/* drop ref taken in j1939_session_skb_queue() */
+		skb_unref(skb);
+		kfree_skb(skb);
+	}
+	__j1939_session_drop(session);
+	netdev_put(session->priv->ndev, &session->priv_dev_tracker);
+	j1939_priv_put(session->priv);
+	kfree(session);
+}
+
+static void __j1939_session_release(struct kref *kref)
+{
+	struct j1939_session *session = container_of(kref, struct j1939_session,
+						     kref);
+
+	j1939_session_destroy(session);
+}
+
+void j1939_session_put(struct j1939_session *session)
+{
+	kref_put(&session->kref, __j1939_session_release);
+}
+
+static void j1939_session_txtimer_cancel(struct j1939_session *session)
+{
+	if (hrtimer_cancel(&session->txtimer))
+		j1939_session_put(session);
+}
+
+static void j1939_session_rxtimer_cancel(struct j1939_session *session)
+{
+	if (hrtimer_cancel(&session->rxtimer))
+		j1939_session_put(session);
+}
+
+void j1939_session_timers_cancel(struct j1939_session *session)
+{
+	j1939_session_txtimer_cancel(session);
+	j1939_session_rxtimer_cancel(session);
+}
+
+static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
+{
+	return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
+}
+
+static void j1939_session_skb_drop_old(struct j1939_session *session)
+{
+	struct sk_buff *do_skb;
+	struct j1939_sk_buff_cb *do_skcb;
+	unsigned int offset_start;
+	unsigned long flags;
+
+	if (skb_queue_len(&session->skb_queue) < 2)
+		return;
+
+	offset_start = session->pkt.tx_acked * 7;
+
+	spin_lock_irqsave(&session->skb_queue.lock, flags);
+	do_skb = skb_peek(&session->skb_queue);
+	do_skcb = j1939_skb_to_cb(do_skb);
+
+	if ((do_skcb->offset + do_skb->len) < offset_start) {
+		__skb_unlink(do_skb, &session->skb_queue);
+		/* drop ref taken in j1939_session_skb_queue() */
+		skb_unref(do_skb);
+		spin_unlock_irqrestore(&session->skb_queue.lock, flags);
+
+		kfree_skb(do_skb);
+	} else {
+		spin_unlock_irqrestore(&session->skb_queue.lock, flags);
+	}
+}
+
+static bool j1939_address_is_local(struct j1939_priv *priv, u8 addr)
+{
+	bool local = false;
+
+	read_lock_bh(&priv->lock);
+	if (j1939_address_is_unicast(addr) && priv->ents[addr].nusers)
+		local = true;
+	read_unlock_bh(&priv->lock);
+
+	return local;
+}
+
+void j1939_session_skb_queue(struct j1939_session *session,
+			     struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_priv *priv = session->priv;
+
+	j1939_ac_fixup(priv, skb);
+
+	if (j1939_address_is_local(priv, skcb->addr.da))
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+
+	skcb->flags |= J1939_ECU_LOCAL_SRC;
+
+	skb_get(skb);
+	skb_queue_tail(&session->skb_queue, skb);
+}
+
+static struct
+sk_buff *j1939_session_skb_get_by_offset(struct j1939_session *session,
+					 unsigned int offset_start)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *do_skcb;
+	struct sk_buff *skb = NULL;
+	struct sk_buff *do_skb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&session->skb_queue.lock, flags);
+	skb_queue_walk(&session->skb_queue, do_skb) {
+		do_skcb = j1939_skb_to_cb(do_skb);
+
+		if ((offset_start >= do_skcb->offset &&
+		     offset_start < (do_skcb->offset + do_skb->len)) ||
+		     (offset_start == 0 && do_skcb->offset == 0 && do_skb->len == 0)) {
+			skb = do_skb;
+		}
+	}
+
+	if (skb)
+		skb_get(skb);
+
+	spin_unlock_irqrestore(&session->skb_queue.lock, flags);
+
+	if (!skb)
+		netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
+			   __func__, session, offset_start,
+			   skb_queue_len(&session->skb_queue));
+
+	return skb;
+}
+
+static struct sk_buff *j1939_session_skb_get(struct j1939_session *session)
+{
+	unsigned int offset_start;
+
+	offset_start = session->pkt.dpo * 7;
+	return j1939_session_skb_get_by_offset(session, offset_start);
+}
+
+/* see if we are receiver
+ * returns 0 for broadcasts, although we will receive them
+ */
+static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & J1939_ECU_LOCAL_DST;
+}
+
+/* see if we are sender */
+static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & J1939_ECU_LOCAL_SRC;
+}
+
+/* see if we are involved as either receiver or transmitter */
+static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
+{
+	if (swap)
+		return j1939_tp_im_receiver(skcb);
+	else
+		return j1939_tp_im_transmitter(skcb);
+}
+
+static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
+{
+	return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
+}
+
+/* extract pgn from flow-ctl message */
+static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
+{
+	pgn_t pgn;
+
+	pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
+	if (j1939_pgn_is_pdu1(pgn))
+		pgn &= 0xffff00;
+	return pgn;
+}
+
+static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
+{
+	return (dat[2] << 8) + (dat[1] << 0);
+}
+
+static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
+{
+	return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
+}
+
+static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
+{
+	return (dat[4] << 24) | (dat[3] << 16) |
+		(dat[2] << 8) | (dat[1] << 0);
+}
+
+/* find existing session:
+ * reverse: swap cb's src & dst
+ * there is no problem with matching broadcasts, since
+ * broadcasts (no dst, no da) would never call this
+ * with reverse == true
+ */
+static bool j1939_session_match(struct j1939_addr *se_addr,
+				struct j1939_addr *sk_addr, bool reverse)
+{
+	if (se_addr->type != sk_addr->type)
+		return false;
+
+	if (reverse) {
+		if (se_addr->src_name) {
+			if (se_addr->src_name != sk_addr->dst_name)
+				return false;
+		} else if (se_addr->sa != sk_addr->da) {
+			return false;
+		}
+
+		if (se_addr->dst_name) {
+			if (se_addr->dst_name != sk_addr->src_name)
+				return false;
+		} else if (se_addr->da != sk_addr->sa) {
+			return false;
+		}
+	} else {
+		if (se_addr->src_name) {
+			if (se_addr->src_name != sk_addr->src_name)
+				return false;
+		} else if (se_addr->sa != sk_addr->sa) {
+			return false;
+		}
+
+		if (se_addr->dst_name) {
+			if (se_addr->dst_name != sk_addr->dst_name)
+				return false;
+		} else if (se_addr->da != sk_addr->da) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static struct
+j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
+						struct list_head *root,
+						struct j1939_addr *addr,
+						bool reverse, bool transmitter)
+{
+	struct j1939_session *session;
+
+	lockdep_assert_held(&priv->active_session_list_lock);
+
+	list_for_each_entry(session, root, active_session_list_entry) {
+		j1939_session_get(session);
+		if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
+		    session->transmission == transmitter)
+			return session;
+		j1939_session_put(session);
+	}
+
+	return NULL;
+}
+
+static struct
+j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
+					struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	lockdep_assert_held(&priv->active_session_list_lock);
+
+	list_for_each_entry(session, &priv->active_session_list,
+			    active_session_list_entry) {
+		j1939_session_get(session);
+		if (session->skcb.addr.type == J1939_SIMPLE &&
+		    session->tskey == skcb->tskey && session->sk == skb->sk)
+			return session;
+		j1939_session_put(session);
+	}
+
+	return NULL;
+}
+
+static struct
+j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
+					 struct j1939_addr *addr,
+					 bool reverse, bool transmitter)
+{
+	struct j1939_session *session;
+
+	j1939_session_list_lock(priv);
+	session = j1939_session_get_by_addr_locked(priv,
+						   &priv->active_session_list,
+						   addr, reverse, transmitter);
+	j1939_session_list_unlock(priv);
+
+	return session;
+}
+
+static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
+{
+	u8 tmp = 0;
+
+	swap(skcb->addr.dst_name, skcb->addr.src_name);
+	swap(skcb->addr.da, skcb->addr.sa);
+
+	/* swap SRC and DST flags, leave other untouched */
+	if (skcb->flags & J1939_ECU_LOCAL_SRC)
+		tmp |= J1939_ECU_LOCAL_DST;
+	if (skcb->flags & J1939_ECU_LOCAL_DST)
+		tmp |= J1939_ECU_LOCAL_SRC;
+	skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
+	skcb->flags |= tmp;
+}
+
+static struct
+sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
+			     const struct j1939_sk_buff_cb *re_skcb,
+			     bool ctl,
+			     bool swap_src_dst)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct j1939_sk_buff_cb *skcb;
+
+	skb = alloc_skb(sizeof(struct can_frame), GFP_ATOMIC);
+	if (unlikely(!skb))
+		return ERR_PTR(-ENOMEM);
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	skb->dev = priv->ndev;
+	csx->can_iif = priv->ndev->ifindex;
+	/* reserve CAN header */
+	skb_reserve(skb, offsetof(struct can_frame, data));
+
+	/* skb->cb must be large enough to hold a j1939_sk_buff_cb structure */
+	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*re_skcb));
+
+	memcpy(skb->cb, re_skcb, sizeof(*re_skcb));
+	skcb = j1939_skb_to_cb(skb);
+	if (swap_src_dst)
+		j1939_skbcb_swap(skcb);
+
+	if (ctl) {
+		if (skcb->addr.type == J1939_ETP)
+			skcb->addr.pgn = J1939_ETP_PGN_CTL;
+		else
+			skcb->addr.pgn = J1939_TP_PGN_CTL;
+	} else {
+		if (skcb->addr.type == J1939_ETP)
+			skcb->addr.pgn = J1939_ETP_PGN_DAT;
+		else
+			skcb->addr.pgn = J1939_TP_PGN_DAT;
+	}
+
+	return skb;
+}
+
+/* TP transmit packet functions */
+static int j1939_tp_tx_dat(struct j1939_session *session,
+			   const u8 *dat, int len)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sk_buff *skb;
+
+	skb = j1939_tp_tx_dat_new(priv, &session->skcb,
+				  false, false);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	skb_put_data(skb, dat, len);
+	if (j1939_tp_padding && len < 8)
+		memset(skb_put(skb, 8 - len), 0xff, 8 - len);
+
+	return j1939_send_one(priv, skb);
+}
+
+static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
+			       const struct j1939_sk_buff_cb *re_skcb,
+			       bool swap_src_dst, pgn_t pgn, const u8 *dat)
+{
+	struct sk_buff *skb;
+	u8 *skdat;
+
+	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
+		return 0;
+
+	skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
+	if (IS_ERR(skb))
+		return PTR_ERR(skb);
+
+	skdat = skb_put(skb, 8);
+	memcpy(skdat, dat, 5);
+	skdat[5] = (pgn >> 0);
+	skdat[6] = (pgn >> 8);
+	skdat[7] = (pgn >> 16);
+
+	return j1939_send_one(priv, skb);
+}
+
+static inline int j1939_tp_tx_ctl(struct j1939_session *session,
+				  bool swap_src_dst, const u8 *dat)
+{
+	struct j1939_priv *priv = session->priv;
+
+	return j1939_xtp_do_tx_ctl(priv, &session->skcb,
+				   swap_src_dst,
+				   session->skcb.addr.pgn, dat);
+}
+
+static int j1939_xtp_tx_abort(struct j1939_priv *priv,
+			      const struct j1939_sk_buff_cb *re_skcb,
+			      bool swap_src_dst,
+			      enum j1939_xtp_abort err,
+			      pgn_t pgn)
+{
+	u8 dat[5];
+
+	if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
+		return 0;
+
+	memset(dat, 0xff, sizeof(dat));
+	dat[0] = J1939_TP_CMD_ABORT;
+	dat[1] = err;
+	return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
+}
+
+void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
+{
+	j1939_session_get(session);
+	hrtimer_start(&session->txtimer, ms_to_ktime(msec),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
+					  int msec)
+{
+	j1939_session_rxtimer_cancel(session);
+	j1939_session_get(session);
+	hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
+		      HRTIMER_MODE_REL_SOFT);
+}
+
+static int j1939_session_tx_rts(struct j1939_session *session)
+{
+	u8 dat[8];
+	int ret;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	dat[1] = (session->total_message_size >> 0);
+	dat[2] = (session->total_message_size >> 8);
+	dat[3] = session->pkt.total;
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		dat[0] = J1939_ETP_CMD_RTS;
+		dat[1] = (session->total_message_size >> 0);
+		dat[2] = (session->total_message_size >> 8);
+		dat[3] = (session->total_message_size >> 16);
+		dat[4] = (session->total_message_size >> 24);
+	} else if (j1939_cb_is_broadcast(&session->skcb)) {
+		dat[0] = J1939_TP_CMD_BAM;
+		/* fake cts for broadcast */
+		session->pkt.tx = 0;
+	} else {
+		dat[0] = J1939_TP_CMD_RTS;
+		dat[4] = dat[3];
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, false, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+	if (dat[0] == J1939_TP_CMD_BAM) {
+		j1939_tp_schedule_txtimer(session, 50);
+		j1939_tp_set_rxtimeout(session, 250);
+	} else {
+		j1939_tp_set_rxtimeout(session, 1250);
+	}
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_dpo(struct j1939_session *session)
+{
+	unsigned int pkt;
+	u8 dat[8];
+	int ret;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	dat[0] = J1939_ETP_CMD_DPO;
+	session->pkt.dpo = session->pkt.tx_acked;
+	pkt = session->pkt.dpo;
+	dat[1] = session->pkt.last - session->pkt.tx_acked;
+	dat[2] = (pkt >> 0);
+	dat[3] = (pkt >> 8);
+	dat[4] = (pkt >> 16);
+
+	ret = j1939_tp_tx_ctl(session, false, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 1250);
+	session->pkt.tx = session->pkt.tx_acked;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_dat(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *se_skcb;
+	int offset, pkt_done, pkt_end;
+	unsigned int len, pdelay;
+	struct sk_buff *se_skb;
+	const u8 *tpdat;
+	int ret = 0;
+	u8 dat[8];
+
+	se_skb = j1939_session_skb_get_by_offset(session, session->pkt.tx * 7);
+	if (!se_skb)
+		return -ENOBUFS;
+
+	se_skcb = j1939_skb_to_cb(se_skb);
+	tpdat = se_skb->data;
+	ret = 0;
+	pkt_done = 0;
+	if (session->skcb.addr.type != J1939_ETP &&
+	    j1939_cb_is_broadcast(&session->skcb))
+		pkt_end = session->pkt.total;
+	else
+		pkt_end = session->pkt.last;
+
+	while (session->pkt.tx < pkt_end) {
+		dat[0] = session->pkt.tx - session->pkt.dpo + 1;
+		offset = (session->pkt.tx * 7) - se_skcb->offset;
+		len =  se_skb->len - offset;
+		if (len > 7)
+			len = 7;
+
+		if (offset + len > se_skb->len) {
+			netdev_err_once(priv->ndev,
+					"%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
+					__func__, session, se_skcb->offset,
+					se_skb->len , session->pkt.tx);
+			ret = -EOVERFLOW;
+			goto out_free;
+		}
+
+		if (!len) {
+			ret = -ENOBUFS;
+			break;
+		}
+
+		memcpy(&dat[1], &tpdat[offset], len);
+		ret = j1939_tp_tx_dat(session, dat, len + 1);
+		if (ret < 0) {
+			/* ENOBUFS == CAN interface TX queue is full */
+			if (ret != -ENOBUFS)
+				netdev_alert(priv->ndev,
+					     "%s: 0x%p: queue data error: %i\n",
+					     __func__, session, ret);
+			break;
+		}
+
+		session->last_txcmd = 0xff;
+		pkt_done++;
+		session->pkt.tx++;
+		pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
+			j1939_tp_packet_delay;
+
+		if (session->pkt.tx < session->pkt.total && pdelay) {
+			j1939_tp_schedule_txtimer(session, pdelay);
+			break;
+		}
+	}
+
+	if (pkt_done)
+		j1939_tp_set_rxtimeout(session, 250);
+
+ out_free:
+	if (ret)
+		kfree_skb(se_skb);
+	else
+		consume_skb(se_skb);
+
+	return ret;
+}
+
+static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (!j1939_tp_im_transmitter(&session->skcb)) {
+		netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
+			     __func__, session);
+		return -EINVAL;
+	}
+
+	switch (session->last_cmd) {
+	case 0:
+		ret = j1939_session_tx_rts(session);
+		break;
+
+	case J1939_ETP_CMD_CTS:
+		if (session->last_txcmd != J1939_ETP_CMD_DPO) {
+			ret = j1939_session_tx_dpo(session);
+			if (ret)
+				return ret;
+		}
+
+		fallthrough;
+	case J1939_TP_CMD_CTS:
+	case 0xff: /* did some data */
+	case J1939_ETP_CMD_DPO:
+	case J1939_TP_CMD_BAM:
+		ret = j1939_session_tx_dat(session);
+
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
+			     __func__, session, session->last_cmd);
+	}
+
+	return ret;
+}
+
+static int j1939_session_tx_cts(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	unsigned int pkt, len;
+	int ret;
+	u8 dat[8];
+
+	if (!j1939_sk_recv_match(priv, &session->skcb))
+		return -ENOENT;
+
+	len = session->pkt.total - session->pkt.rx;
+	len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
+	memset(dat, 0xff, sizeof(dat));
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		pkt = session->pkt.rx + 1;
+		dat[0] = J1939_ETP_CMD_CTS;
+		dat[1] = len;
+		dat[2] = (pkt >> 0);
+		dat[3] = (pkt >> 8);
+		dat[4] = (pkt >> 16);
+	} else {
+		dat[0] = J1939_TP_CMD_CTS;
+		dat[1] = len;
+		dat[2] = session->pkt.rx + 1;
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, true, dat);
+	if (ret < 0)
+		return ret;
+
+	if (len)
+		/* only mark cts done when len is set */
+		session->last_txcmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_session_tx_eoma(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	u8 dat[8];
+	int ret;
+
+	if (!j1939_sk_recv_match(priv, &session->skcb))
+		return -ENOENT;
+
+	memset(dat, 0xff, sizeof(dat));
+
+	if (session->skcb.addr.type == J1939_ETP) {
+		dat[0] = J1939_ETP_CMD_EOMA;
+		dat[1] = session->total_message_size >> 0;
+		dat[2] = session->total_message_size >> 8;
+		dat[3] = session->total_message_size >> 16;
+		dat[4] = session->total_message_size >> 24;
+	} else {
+		dat[0] = J1939_TP_CMD_EOMA;
+		dat[1] = session->total_message_size;
+		dat[2] = session->total_message_size >> 8;
+		dat[3] = session->pkt.total;
+	}
+
+	if (dat[0] == session->last_txcmd)
+		/* done already */
+		return 0;
+
+	ret = j1939_tp_tx_ctl(session, true, dat);
+	if (ret < 0)
+		return ret;
+
+	session->last_txcmd = dat[0];
+
+	/* wait for the EOMA packet to come in */
+	j1939_tp_set_rxtimeout(session, 1250);
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static int j1939_xtp_txnext_receiver(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (!j1939_tp_im_receiver(&session->skcb)) {
+		netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
+			     __func__, session);
+		return -EINVAL;
+	}
+
+	switch (session->last_cmd) {
+	case J1939_TP_CMD_RTS:
+	case J1939_ETP_CMD_RTS:
+		ret = j1939_session_tx_cts(session);
+		break;
+
+	case J1939_ETP_CMD_CTS:
+	case J1939_TP_CMD_CTS:
+	case 0xff: /* did some data */
+	case J1939_ETP_CMD_DPO:
+		if ((session->skcb.addr.type == J1939_TP &&
+		     j1939_cb_is_broadcast(&session->skcb)))
+			break;
+
+		if (session->pkt.rx >= session->pkt.total) {
+			ret = j1939_session_tx_eoma(session);
+		} else if (session->pkt.rx >= session->pkt.last) {
+			session->last_txcmd = 0;
+			ret = j1939_session_tx_cts(session);
+		}
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
+			     __func__, session, session->last_cmd);
+	}
+
+	return ret;
+}
+
+static int j1939_simple_txnext(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct sk_buff *se_skb = j1939_session_skb_get(session);
+	struct sk_buff *skb;
+	int ret;
+
+	if (!se_skb)
+		return 0;
+
+	skb = skb_clone(se_skb, GFP_ATOMIC);
+	if (!skb) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	/* the cloned skb points to the skb extension of the original se_skb
+	 * with an increased refcount. skb_ext_add() creates a copy to
+	 * separate the skb extension data which is needed to modify the
+	 * can_framelen in can_put_echo_skb().
+	 */
+	if (!skb_ext_add(skb, SKB_EXT_CAN)) {
+		kfree_skb(skb);
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	can_skb_set_owner(skb, se_skb->sk);
+
+	j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
+
+	ret = j1939_send_one(priv, skb);
+	if (ret)
+		goto out_free;
+
+	j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_SCHED);
+	j1939_sk_queue_activate_next(session);
+
+ out_free:
+	if (ret)
+		kfree_skb(se_skb);
+	else
+		consume_skb(se_skb);
+
+	return ret;
+}
+
+static bool j1939_session_deactivate_locked(struct j1939_session *session)
+{
+	bool active = false;
+
+	lockdep_assert_held(&session->priv->active_session_list_lock);
+
+	if (session->state >= J1939_SESSION_ACTIVE &&
+	    session->state < J1939_SESSION_ACTIVE_MAX) {
+		active = true;
+
+		list_del_init(&session->active_session_list_entry);
+		session->state = J1939_SESSION_DONE;
+		j1939_session_put(session);
+	}
+
+	return active;
+}
+
+static bool j1939_session_deactivate(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	bool active;
+
+	j1939_session_list_lock(priv);
+	active = j1939_session_deactivate_locked(session);
+	j1939_session_list_unlock(priv);
+
+	return active;
+}
+
+static void
+j1939_session_deactivate_activate_next(struct j1939_session *session)
+{
+	if (j1939_session_deactivate(session))
+		j1939_sk_queue_activate_next(session);
+}
+
+static void __j1939_session_cancel(struct j1939_session *session,
+				   enum j1939_xtp_abort err)
+{
+	struct j1939_priv *priv = session->priv;
+
+	WARN_ON_ONCE(!err);
+	lockdep_assert_held(&session->priv->active_session_list_lock);
+
+	session->err = j1939_xtp_abort_to_errno(priv, err);
+	session->state = J1939_SESSION_WAITING_ABORT;
+	/* do not send aborts on incoming broadcasts */
+	if (!j1939_cb_is_broadcast(&session->skcb)) {
+		j1939_xtp_tx_abort(priv, &session->skcb,
+				   !session->transmission,
+				   err, session->skcb.addr.pgn);
+	}
+
+	if (session->sk)
+		j1939_sk_send_loop_abort(session->sk, session->err);
+}
+
+static void j1939_session_cancel(struct j1939_session *session,
+				 enum j1939_xtp_abort err)
+{
+	j1939_session_list_lock(session->priv);
+
+	if (session->state >= J1939_SESSION_ACTIVE &&
+	    session->state < J1939_SESSION_WAITING_ABORT) {
+		j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
+		__j1939_session_cancel(session, err);
+	}
+
+	j1939_session_list_unlock(session->priv);
+
+	if (!session->sk)
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
+}
+
+static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
+{
+	struct j1939_session *session =
+		container_of(hrtimer, struct j1939_session, txtimer);
+	struct j1939_priv *priv = session->priv;
+	int ret = 0;
+
+	if (session->skcb.addr.type == J1939_SIMPLE) {
+		ret = j1939_simple_txnext(session);
+	} else {
+		if (session->transmission)
+			ret = j1939_xtp_txnext_transmiter(session);
+		else
+			ret = j1939_xtp_txnext_receiver(session);
+	}
+
+	switch (ret) {
+	case -ENOBUFS:
+		/* Retry limit is currently arbitrary chosen */
+		if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
+			session->tx_retry++;
+			j1939_tp_schedule_txtimer(session,
+						  10 + get_random_u32_below(16));
+		} else {
+			netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
+				     __func__, session);
+			session->err = -ENETUNREACH;
+			j1939_session_rxtimer_cancel(session);
+			j1939_session_deactivate_activate_next(session);
+		}
+		break;
+	case -ENETDOWN:
+		/* In this case we should get a netdev_event(), all active
+		 * sessions will be cleared by j1939_cancel_active_session().
+		 * So handle this as an error, but let
+		 * j1939_cancel_active_session() do the cleanup including
+		 * propagation of the error to user space.
+		 */
+		break;
+	case -EOVERFLOW:
+		j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
+		break;
+	case 0:
+		session->tx_retry = 0;
+		break;
+	default:
+		netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
+			     __func__, session, ret);
+		if (session->skcb.addr.type != J1939_SIMPLE) {
+			j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
+		} else {
+			session->err = ret;
+			j1939_session_rxtimer_cancel(session);
+			j1939_session_deactivate_activate_next(session);
+		}
+	}
+
+	j1939_session_put(session);
+
+	return HRTIMER_NORESTART;
+}
+
+static void j1939_session_completed(struct j1939_session *session)
+{
+	struct sk_buff *se_skb;
+
+	if (!session->transmission) {
+		se_skb = j1939_session_skb_get(session);
+		/* distribute among j1939 receivers */
+		j1939_sk_recv(session->priv, se_skb);
+		consume_skb(se_skb);
+	}
+
+	j1939_session_deactivate_activate_next(session);
+}
+
+static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
+{
+	struct j1939_session *session = container_of(hrtimer,
+						     struct j1939_session,
+						     rxtimer);
+	struct j1939_priv *priv = session->priv;
+
+	if (session->state == J1939_SESSION_WAITING_ABORT) {
+		netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
+			     __func__, session);
+
+		j1939_session_deactivate_activate_next(session);
+
+	} else if (session->skcb.addr.type == J1939_SIMPLE) {
+		netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
+			     __func__, session);
+
+		/* The message is probably stuck in the CAN controller and can
+		 * be send as soon as CAN bus is in working state again.
+		 */
+		session->err = -ETIME;
+		j1939_session_deactivate(session);
+	} else {
+		j1939_session_list_lock(session->priv);
+		if (session->state >= J1939_SESSION_ACTIVE &&
+		    session->state < J1939_SESSION_ACTIVE_MAX) {
+			netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
+				     __func__, session);
+			j1939_session_get(session);
+			hrtimer_start(&session->rxtimer,
+				      ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
+				      HRTIMER_MODE_REL_SOFT);
+			__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
+		}
+		j1939_session_list_unlock(session->priv);
+
+		if (!session->sk)
+			j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
+	}
+
+	j1939_session_put(session);
+
+	return HRTIMER_NORESTART;
+}
+
+static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
+				     const struct sk_buff *skb)
+{
+	const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
+	struct j1939_priv *priv = session->priv;
+	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
+	u8 cmd = skb->data[0];
+
+	if (session->skcb.addr.pgn == pgn)
+		return false;
+
+	switch (cmd) {
+	case J1939_TP_CMD_BAM:
+		abort = J1939_XTP_NO_ABORT;
+		break;
+
+	case J1939_ETP_CMD_RTS:
+		fallthrough;
+	case J1939_TP_CMD_RTS:
+		abort = J1939_XTP_ABORT_BUSY;
+		break;
+
+	case J1939_ETP_CMD_CTS:
+		fallthrough;
+	case J1939_TP_CMD_CTS:
+		abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
+		break;
+
+	case J1939_ETP_CMD_DPO:
+		abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
+		break;
+
+	case J1939_ETP_CMD_EOMA:
+		fallthrough;
+	case J1939_TP_CMD_EOMA:
+		abort = J1939_XTP_ABORT_OTHER;
+		break;
+
+	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
+		abort = J1939_XTP_NO_ABORT;
+		break;
+
+	default:
+		WARN_ON_ONCE(1);
+		break;
+	}
+
+	netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
+		    __func__, session, cmd, pgn, session->skcb.addr.pgn);
+	if (abort != J1939_XTP_NO_ABORT)
+		j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
+
+	return true;
+}
+
+static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
+				   bool reverse, bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	u8 abort = skb->data[1];
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
+					    transmitter);
+	if (!session)
+		return;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		goto abort_put;
+
+	netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
+		    session, j1939_xtp_ctl_to_pgn(skb->data), abort,
+		    j1939_xtp_abort_to_str(abort));
+
+	j1939_session_timers_cancel(session);
+	session->err = j1939_xtp_abort_to_errno(priv, abort);
+	if (session->sk)
+		j1939_sk_send_loop_abort(session->sk, session->err);
+	else
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
+	j1939_session_deactivate_activate_next(session);
+
+abort_put:
+	j1939_session_put(session);
+}
+
+/* abort packets may come in 2 directions */
+static void
+j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
+		   bool transmitter)
+{
+	j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
+	j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
+}
+
+static void
+j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	const u8 *dat;
+	int len;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	dat = skb->data;
+
+	if (skcb->addr.type == J1939_ETP)
+		len = j1939_etp_ctl_to_size(dat);
+	else
+		len = j1939_tp_ctl_to_size(dat);
+
+	if (session->total_message_size != len) {
+		netdev_warn_once(session->priv->ndev,
+				 "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
+				 __func__, session, session->total_message_size,
+				 len);
+	}
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	session->pkt.tx_acked = session->pkt.total;
+	j1939_session_timers_cancel(session);
+	/* transmitted without problems */
+	j1939_session_completed(session);
+}
+
+static void
+j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
+		  bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
+					    transmitter);
+	if (!session)
+		return;
+
+	j1939_xtp_rx_eoma_one(session, skb);
+	j1939_session_put(session);
+}
+
+static void
+j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
+{
+	enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
+	unsigned int pkt;
+	const u8 *dat;
+
+	dat = skb->data;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	if (session->last_cmd == dat[0]) {
+		err = J1939_XTP_ABORT_DUP_SEQ;
+		goto out_session_cancel;
+	}
+
+	if (session->skcb.addr.type == J1939_ETP)
+		pkt = j1939_etp_ctl_to_packet(dat);
+	else
+		pkt = dat[2];
+
+	if (!pkt)
+		goto out_session_cancel;
+	else if (dat[1] > session->pkt.block /* 0xff for etp */)
+		goto out_session_cancel;
+
+	/* set packet counters only when not CTS(0) */
+	session->pkt.tx_acked = pkt - 1;
+	j1939_session_skb_drop_old(session);
+	session->pkt.last = session->pkt.tx_acked + dat[1];
+	if (session->pkt.last > session->pkt.total)
+		/* safety measure */
+		session->pkt.last = session->pkt.total;
+	/* TODO: do not set tx here, do it in txtimer */
+	session->pkt.tx = session->pkt.tx_acked;
+
+	session->last_cmd = dat[0];
+	if (dat[1]) {
+		j1939_tp_set_rxtimeout(session, 1250);
+		if (session->transmission) {
+			if (session->pkt.tx_acked)
+				j1939_sk_errqueue(session,
+						  J1939_ERRQUEUE_TX_SCHED);
+			j1939_session_txtimer_cancel(session);
+			j1939_tp_schedule_txtimer(session, 0);
+		}
+	} else {
+		/* CTS(0) */
+		j1939_tp_set_rxtimeout(session, 550);
+	}
+	return;
+
+ out_session_cancel:
+	j1939_session_timers_cancel(session);
+	j1939_session_cancel(session, err);
+}
+
+static void
+j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, true,
+					    transmitter);
+	if (!session)
+		return;
+	j1939_xtp_rx_cts_one(session, skb);
+	j1939_session_put(session);
+}
+
+static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
+					       struct sk_buff *skb, size_t size)
+{
+	struct j1939_session *session;
+	struct j1939_sk_buff_cb *skcb;
+
+	session = kzalloc_obj(*session, gfp_any());
+	if (!session)
+		return NULL;
+
+	INIT_LIST_HEAD(&session->active_session_list_entry);
+	INIT_LIST_HEAD(&session->sk_session_queue_entry);
+	kref_init(&session->kref);
+	netdev_hold(priv->ndev, &session->priv_dev_tracker, gfp_any());
+
+	j1939_priv_get(priv);
+	session->priv = priv;
+	session->total_message_size = size;
+	session->state = J1939_SESSION_NEW;
+
+	skb_queue_head_init(&session->skb_queue);
+	skb_queue_tail(&session->skb_queue, skb_get(skb));
+
+	skcb = j1939_skb_to_cb(skb);
+	memcpy(&session->skcb, skcb, sizeof(session->skcb));
+
+	hrtimer_setup(&session->txtimer, j1939_tp_txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+	hrtimer_setup(&session->rxtimer, j1939_tp_rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+
+	netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
+		   __func__, session, skcb->addr.sa, skcb->addr.da);
+
+	return session;
+}
+
+static struct
+j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
+				       int size,
+				       const struct j1939_sk_buff_cb *rel_skcb)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct j1939_sk_buff_cb *skcb;
+	struct j1939_session *session;
+
+	skb = alloc_skb(size, GFP_ATOMIC);
+	if (unlikely(!skb))
+		return NULL;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb->dev = priv->ndev;
+	csx->can_iif = priv->ndev->ifindex;
+	skcb = j1939_skb_to_cb(skb);
+	memcpy(skcb, rel_skcb, sizeof(*skcb));
+
+	session = j1939_session_new(priv, skb, size);
+	if (!session) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* alloc data area */
+	skb_put_zero(skb, size);
+	/* skb is recounted in j1939_session_new() */
+	return session;
+}
+
+int j1939_session_activate(struct j1939_session *session)
+{
+	struct j1939_priv *priv = session->priv;
+	struct j1939_session *active = NULL;
+	int ret = 0;
+
+	j1939_session_list_lock(priv);
+	if (session->skcb.addr.type != J1939_SIMPLE)
+		active = j1939_session_get_by_addr_locked(priv,
+							  &priv->active_session_list,
+							  &session->skcb.addr, false,
+							  session->transmission);
+	if (active) {
+		j1939_session_put(active);
+		ret = -EAGAIN;
+	} else if (priv->ndev->reg_state != NETREG_REGISTERED) {
+		ret = -ENODEV;
+	} else {
+		WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
+		list_add_tail(&session->active_session_list_entry,
+			      &priv->active_session_list);
+		j1939_session_get(session);
+		session->state = J1939_SESSION_ACTIVE;
+
+		netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
+			   __func__, session);
+	}
+	j1939_session_list_unlock(priv);
+
+	return ret;
+}
+
+static struct
+j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
+					    struct sk_buff *skb)
+{
+	enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
+	struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	const u8 *dat;
+	int len, ret;
+	pgn_t pgn;
+
+	netdev_dbg(priv->ndev, "%s\n", __func__);
+
+	dat = skb->data;
+	pgn = j1939_xtp_ctl_to_pgn(dat);
+	skcb.addr.pgn = pgn;
+
+	if (!j1939_sk_recv_match(priv, &skcb))
+		return NULL;
+
+	if (skcb.addr.type == J1939_ETP) {
+		len = j1939_etp_ctl_to_size(dat);
+		if (len > J1939_MAX_ETP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+		else if (len > priv->tp_max_packet_size)
+			abort = J1939_XTP_ABORT_RESOURCE;
+		else if (len <= J1939_MAX_TP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+	} else {
+		len = j1939_tp_ctl_to_size(dat);
+		if (len > J1939_MAX_TP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+		else if (len > priv->tp_max_packet_size)
+			abort = J1939_XTP_ABORT_RESOURCE;
+		else if (len < J1939_MIN_TP_PACKET_SIZE)
+			abort = J1939_XTP_ABORT_FAULT;
+	}
+
+	if (abort != J1939_XTP_NO_ABORT) {
+		j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
+		return NULL;
+	}
+
+	session = j1939_session_fresh_new(priv, len, &skcb);
+	if (!session) {
+		j1939_xtp_tx_abort(priv, &skcb, true,
+				   J1939_XTP_ABORT_RESOURCE, pgn);
+		return NULL;
+	}
+
+	/* initialize the control buffer: plain copy */
+	session->pkt.total = (len + 6) / 7;
+	session->pkt.block = 0xff;
+	if (skcb.addr.type != J1939_ETP) {
+		if (dat[3] != session->pkt.total)
+			netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
+				     __func__, session, session->pkt.total,
+				     dat[3]);
+		session->pkt.total = dat[3];
+		session->pkt.block = min(dat[3], dat[4]);
+	}
+
+	session->pkt.rx = 0;
+	session->pkt.tx = 0;
+
+	session->tskey = priv->rx_tskey++;
+	j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_RTS);
+
+	ret = j1939_session_activate(session);
+	if (ret) {
+		/* Entering this scope indicates an issue with the J1939 bus.
+		 * Possible scenarios include:
+		 * - A time lapse occurred, and a new session was initiated
+		 *   due to another packet being sent correctly. This could
+		 *   have been caused by too long interrupt, debugger, or being
+		 *   out-scheduled by another task.
+		 * - The bus is receiving numerous erroneous packets, either
+		 *   from a malfunctioning device or during a test scenario.
+		 */
+		netdev_alert(priv->ndev, "%s: 0x%p: concurrent session with same addr (%02x %02x) is already active.\n",
+			     __func__, session, skcb.addr.sa, skcb.addr.da);
+		j1939_session_put(session);
+		return NULL;
+	}
+
+	return session;
+}
+
+static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
+					   struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_priv *priv = session->priv;
+
+	if (!session->transmission) {
+		if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+			return -EBUSY;
+
+		/* RTS on active session */
+		j1939_session_timers_cancel(session);
+		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
+	}
+
+	if (session->last_cmd != 0) {
+		/* we received a second rts on the same connection */
+		netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
+			     __func__, session, skcb->addr.sa, skcb->addr.da,
+			     session->last_cmd);
+
+		j1939_session_timers_cancel(session);
+		j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
+		if (session->transmission) {
+			j1939_session_deactivate_activate_next(session);
+		} else if (session->state == J1939_SESSION_WAITING_ABORT) {
+			/* Force deactivation for the receiver.
+			 * If we rely on the timer starting in j1939_session_cancel,
+			 * a second RTS call here will cancel that timer and fail
+			 * to restart it because the state is already WAITING_ABORT.
+			 */
+			j1939_session_deactivate_activate_next(session);
+		}
+
+		return -EBUSY;
+	}
+
+	if (session->skcb.addr.sa != skcb->addr.sa ||
+	    session->skcb.addr.da != skcb->addr.da)
+		netdev_warn(priv->ndev, "%s: 0x%p: session->skcb.addr.sa=0x%02x skcb->addr.sa=0x%02x session->skcb.addr.da=0x%02x skcb->addr.da=0x%02x\n",
+			    __func__, session,
+			    session->skcb.addr.sa, skcb->addr.sa,
+			    session->skcb.addr.da, skcb->addr.da);
+	/* make sure 'sa' & 'da' are correct !
+	 * They may be 'not filled in yet' for sending
+	 * skb's, since they did not pass the Address Claim ever.
+	 */
+	session->skcb.addr.sa = skcb->addr.sa;
+	session->skcb.addr.da = skcb->addr.da;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	return 0;
+}
+
+static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
+			     bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	u8 cmd = skb->data[0];
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+					    transmitter);
+
+	if (!session) {
+		if (transmitter) {
+			/* If we're the transmitter and this function is called,
+			 * we received our own RTS. A session has already been
+			 * created.
+			 *
+			 * For some reasons however it might have been destroyed
+			 * already. So don't create a new one here (using
+			 * "j1939_xtp_rx_rts_session_new()") as this will be a
+			 * receiver session.
+			 *
+			 * The reasons the session is already destroyed might
+			 * be:
+			 * - user space closed socket was and the session was
+			 *   aborted
+			 * - session was aborted due to external abort message
+			 */
+			return;
+		}
+		session = j1939_xtp_rx_rts_session_new(priv, skb);
+		if (!session) {
+			if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
+				netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
+					    __func__);
+			return;
+		}
+	} else {
+		if (j1939_xtp_rx_rts_session_active(session, skb)) {
+			j1939_session_put(session);
+			return;
+		}
+	}
+	session->last_cmd = cmd;
+
+	if (cmd == J1939_TP_CMD_BAM) {
+		if (!session->transmission)
+			j1939_tp_set_rxtimeout(session, 750);
+	} else {
+		if (!session->transmission) {
+			j1939_session_txtimer_cancel(session);
+			j1939_tp_schedule_txtimer(session, 0);
+		}
+		j1939_tp_set_rxtimeout(session, 1250);
+	}
+
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
+				 struct sk_buff *skb)
+{
+	const u8 *dat = skb->data;
+
+	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
+		return;
+
+	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
+
+	/* transmitted without problems */
+	session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
+	session->last_cmd = dat[0];
+	j1939_tp_set_rxtimeout(session, 750);
+
+	if (!session->transmission)
+		j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_DPO);
+}
+
+static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
+			     bool transmitter)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+
+	session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+					    transmitter);
+	if (!session) {
+		netdev_info(priv->ndev,
+			    "%s: no connection found\n", __func__);
+		return;
+	}
+
+	j1939_xtp_rx_dpo_one(session, skb);
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dat_one(struct j1939_session *session,
+				 struct sk_buff *skb)
+{
+	enum j1939_xtp_abort abort = J1939_XTP_ABORT_FAULT;
+	struct j1939_priv *priv = session->priv;
+	struct j1939_sk_buff_cb *skcb, *se_skcb;
+	struct sk_buff *se_skb = NULL;
+	const u8 *dat;
+	u8 *tpdat;
+	int offset;
+	int nbytes;
+	bool final = false;
+	bool remain = false;
+	bool do_cts_eoma = false;
+	int packet;
+
+	skcb = j1939_skb_to_cb(skb);
+	dat = skb->data;
+	if (skb->len != 8) {
+		/* makes no sense */
+		abort = J1939_XTP_ABORT_UNEXPECTED_DATA;
+		goto out_session_cancel;
+	}
+
+	switch (session->last_cmd) {
+	case 0xff:
+		break;
+	case J1939_ETP_CMD_DPO:
+		if (skcb->addr.type == J1939_ETP)
+			break;
+		fallthrough;
+	case J1939_TP_CMD_BAM:
+		fallthrough;
+	case J1939_TP_CMD_CTS:
+		if (skcb->addr.type != J1939_ETP)
+			break;
+		fallthrough;
+	default:
+		netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
+			    session, session->last_cmd);
+		goto out_session_cancel;
+	}
+
+	packet = (dat[0] - 1 + session->pkt.dpo);
+	if (packet > session->pkt.total ||
+	    (session->pkt.rx + 1) > session->pkt.total) {
+		netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
+			    __func__, session);
+		goto out_session_cancel;
+	}
+
+	se_skb = j1939_session_skb_get_by_offset(session, packet * 7);
+	if (!se_skb) {
+		netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
+			    session);
+		goto out_session_cancel;
+	}
+
+	se_skcb = j1939_skb_to_cb(se_skb);
+	offset = packet * 7 - se_skcb->offset;
+	nbytes = se_skb->len - offset;
+	if (nbytes > 7)
+		nbytes = 7;
+	if (nbytes <= 0 || (nbytes + 1) > skb->len) {
+		netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
+			    __func__, session, nbytes, skb->len);
+		goto out_session_cancel;
+	}
+
+	tpdat = se_skb->data;
+	if (!session->transmission) {
+		memcpy(&tpdat[offset], &dat[1], nbytes);
+	} else {
+		int err;
+
+		err = memcmp(&tpdat[offset], &dat[1], nbytes);
+		if (err)
+			netdev_err_once(priv->ndev,
+					"%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
+					__func__, session,
+					nbytes, &dat[1],
+					nbytes, &tpdat[offset]);
+	}
+
+	if (packet == session->pkt.rx)
+		session->pkt.rx++;
+
+	if (se_skcb->addr.type != J1939_ETP &&
+	    j1939_cb_is_broadcast(&session->skcb)) {
+		if (session->pkt.rx >= session->pkt.total)
+			final = true;
+		else
+			remain = true;
+	} else {
+		/* never final, an EOMA must follow */
+		if (session->pkt.rx >= session->pkt.last)
+			do_cts_eoma = true;
+	}
+
+	if (final) {
+		j1939_session_timers_cancel(session);
+		j1939_session_completed(session);
+	} else if (remain) {
+		if (!session->transmission)
+			j1939_tp_set_rxtimeout(session, 750);
+	} else if (do_cts_eoma) {
+		j1939_tp_set_rxtimeout(session, 1250);
+		if (!session->transmission)
+			j1939_tp_schedule_txtimer(session, 0);
+	} else {
+		j1939_tp_set_rxtimeout(session, 750);
+	}
+	session->last_cmd = 0xff;
+	consume_skb(se_skb);
+	j1939_session_put(session);
+
+	return;
+
+ out_session_cancel:
+	kfree_skb(se_skb);
+	j1939_session_timers_cancel(session);
+	j1939_session_cancel(session, abort);
+	j1939_session_put(session);
+}
+
+static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb;
+	struct j1939_session *session;
+
+	skcb = j1939_skb_to_cb(skb);
+
+	if (j1939_tp_im_transmitter(skcb)) {
+		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+						    true);
+		if (!session)
+			netdev_info(priv->ndev, "%s: no tx connection found\n",
+				    __func__);
+		else
+			j1939_xtp_rx_dat_one(session, skb);
+	}
+
+	if (j1939_tp_im_receiver(skcb)) {
+		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+						    false);
+		if (!session)
+			netdev_info(priv->ndev, "%s: no rx connection found\n",
+				    __func__);
+		else
+			j1939_xtp_rx_dat_one(session, skb);
+	}
+
+	if (j1939_cb_is_broadcast(skcb)) {
+		session = j1939_session_get_by_addr(priv, &skcb->addr, false,
+						    false);
+		if (session)
+			j1939_xtp_rx_dat_one(session, skb);
+	}
+}
+
+/* j1939 main intf */
+struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
+				    struct sk_buff *skb, size_t size)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	struct j1939_session *session;
+	int ret;
+
+	if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
+	    skcb->addr.pgn == J1939_TP_PGN_CTL ||
+	    skcb->addr.pgn == J1939_ETP_PGN_DAT ||
+	    skcb->addr.pgn == J1939_ETP_PGN_CTL)
+		/* avoid conflict */
+		return ERR_PTR(-EDOM);
+
+	if (size > priv->tp_max_packet_size)
+		return ERR_PTR(-EMSGSIZE);
+
+	if (size <= 8)
+		skcb->addr.type = J1939_SIMPLE;
+	else if (size > J1939_MAX_TP_PACKET_SIZE)
+		skcb->addr.type = J1939_ETP;
+	else
+		skcb->addr.type = J1939_TP;
+
+	if (skcb->addr.type == J1939_ETP &&
+	    j1939_cb_is_broadcast(skcb))
+		return ERR_PTR(-EDESTADDRREQ);
+
+	/* fill in addresses from names */
+	ret = j1939_ac_fixup(priv, skb);
+	if (unlikely(ret))
+		return ERR_PTR(ret);
+
+	/* fix DST flags, it may be used there soon */
+	if (j1939_address_is_local(priv, skcb->addr.da))
+		skcb->flags |= J1939_ECU_LOCAL_DST;
+
+	/* src is always local, I'm sending ... */
+	skcb->flags |= J1939_ECU_LOCAL_SRC;
+
+	/* prepare new session */
+	session = j1939_session_new(priv, skb, size);
+	if (!session)
+		return ERR_PTR(-ENOMEM);
+
+	/* skb is recounted in j1939_session_new() */
+	sock_hold(skb->sk);
+	session->sk = skb->sk;
+	session->transmission = true;
+	session->pkt.total = (size + 6) / 7;
+	session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
+		min(j1939_tp_block ?: 255, session->pkt.total);
+
+	if (j1939_cb_is_broadcast(&session->skcb))
+		/* set the end-packet for broadcast */
+		session->pkt.last = session->pkt.total;
+
+	skcb->tskey = atomic_inc_return(&session->sk->sk_tskey) - 1;
+	session->tskey = skcb->tskey;
+
+	return session;
+}
+
+static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	int extd = J1939_TP;
+	u8 cmd = skb->data[0];
+
+	switch (cmd) {
+	case J1939_ETP_CMD_RTS:
+		extd = J1939_ETP;
+		fallthrough;
+	case J1939_TP_CMD_BAM:
+		if (cmd == J1939_TP_CMD_BAM && !j1939_cb_is_broadcast(skcb)) {
+			netdev_err_once(priv->ndev, "%s: BAM to unicast (%02x), ignoring!\n",
+					__func__, skcb->addr.sa);
+			return;
+		}
+		fallthrough;
+	case J1939_TP_CMD_RTS:
+		if (skcb->addr.type != extd)
+			return;
+
+		if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
+			netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
+				     __func__, skcb->addr.sa);
+			return;
+		}
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_rts(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
+			j1939_xtp_rx_rts(priv, skb, false);
+
+		break;
+
+	case J1939_ETP_CMD_CTS:
+		extd = J1939_ETP;
+		fallthrough;
+	case J1939_TP_CMD_CTS:
+		if (skcb->addr.type != extd)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_cts(priv, skb, false);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_cts(priv, skb, true);
+
+		break;
+
+	case J1939_ETP_CMD_DPO:
+		if (skcb->addr.type != J1939_ETP)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_dpo(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_dpo(priv, skb, false);
+
+		break;
+
+	case J1939_ETP_CMD_EOMA:
+		extd = J1939_ETP;
+		fallthrough;
+	case J1939_TP_CMD_EOMA:
+		if (skcb->addr.type != extd)
+			return;
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_eoma(priv, skb, false);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_eoma(priv, skb, true);
+
+		break;
+
+	case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
+		if (j1939_cb_is_broadcast(skcb)) {
+			netdev_err_once(priv->ndev, "%s: abort to broadcast (%02x), ignoring!\n",
+					__func__, skcb->addr.sa);
+			return;
+		}
+
+		if (j1939_tp_im_transmitter(skcb))
+			j1939_xtp_rx_abort(priv, skb, true);
+
+		if (j1939_tp_im_receiver(skcb))
+			j1939_xtp_rx_abort(priv, skb, false);
+
+		break;
+	default:
+		return;
+	}
+}
+
+int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+
+	if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
+		return 0;
+
+	switch (skcb->addr.pgn) {
+	case J1939_ETP_PGN_DAT:
+		skcb->addr.type = J1939_ETP;
+		fallthrough;
+	case J1939_TP_PGN_DAT:
+		j1939_xtp_rx_dat(priv, skb);
+		break;
+
+	case J1939_ETP_PGN_CTL:
+		skcb->addr.type = J1939_ETP;
+		fallthrough;
+	case J1939_TP_PGN_CTL:
+		if (skb->len < 8)
+			return 0; /* Don't care. Nothing to extract here */
+
+		j1939_tp_cmd_recv(priv, skb);
+		break;
+	default:
+		return 0; /* no problem */
+	}
+	return 1; /* "I processed the message" */
+}
+
+void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
+{
+	struct j1939_session *session;
+
+	if (!skb->sk)
+		return;
+
+	if (skb->sk->sk_family != AF_CAN ||
+	    skb->sk->sk_protocol != CAN_J1939)
+		return;
+
+	j1939_session_list_lock(priv);
+	session = j1939_session_get_simple(priv, skb);
+	j1939_session_list_unlock(priv);
+	if (!session) {
+		netdev_warn(priv->ndev,
+			    "%s: Received already invalidated message\n",
+			    __func__);
+		return;
+	}
+
+	j1939_session_timers_cancel(session);
+	j1939_session_deactivate(session);
+	j1939_session_put(session);
+}
+
+int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
+{
+	struct j1939_session *session, *saved;
+
+	netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
+	j1939_session_list_lock(priv);
+	list_for_each_entry_safe(session, saved,
+				 &priv->active_session_list,
+				 active_session_list_entry) {
+		if (!sk || sk == session->sk) {
+			if (hrtimer_try_to_cancel(&session->txtimer) == 1)
+				j1939_session_put(session);
+			if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
+				j1939_session_put(session);
+
+			session->err = ESHUTDOWN;
+			j1939_session_deactivate_locked(session);
+		}
+	}
+	j1939_session_list_unlock(priv);
+	return NOTIFY_DONE;
+}
+
+void j1939_tp_init(struct j1939_priv *priv)
+{
+	spin_lock_init(&priv->active_session_list_lock);
+	INIT_LIST_HEAD(&priv->active_session_list);
+	priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
+}
diff --git a/net/can/proc.c b/net/can/proc.c
new file mode 100644
index 000000000..de4d05ae3
--- /dev/null
+++ b/net/can/proc.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * proc.c - procfs support for Protocol family CAN core module
+ *
+ * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/if_arp.h>
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+
+#include "af_can.h"
+
+/*
+ * proc filenames for the PF_CAN core
+ */
+
+#define CAN_PROC_STATS       "stats"
+#define CAN_PROC_RESET_STATS "reset_stats"
+#define CAN_PROC_RCVLIST_ALL "rcvlist_all"
+#define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
+#define CAN_PROC_RCVLIST_INV "rcvlist_inv"
+#define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
+#define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
+#define CAN_PROC_RCVLIST_ERR "rcvlist_err"
+
+static int user_reset;
+
+static const char rx_list_name[][8] = {
+	[RX_ERR] = "rx_err",
+	[RX_ALL] = "rx_all",
+	[RX_FIL] = "rx_fil",
+	[RX_INV] = "rx_inv",
+};
+
+/*
+ * af_can statistics stuff
+ */
+
+static void can_init_stats(struct net *net)
+{
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+	/*
+	 * This memset function is called from a timer context (when
+	 * can_stattimer is active which is the default) OR in a process
+	 * context (reading the proc_fs when can_stattimer is disabled).
+	 */
+	memset(pkg_stats, 0, sizeof(struct can_pkg_stats));
+	pkg_stats->jiffies_init = jiffies;
+
+	rcv_lists_stats->stats_reset++;
+
+	if (user_reset) {
+		user_reset = 0;
+		rcv_lists_stats->user_reset++;
+	}
+}
+
+static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
+			       unsigned long count)
+{
+	if (oldjif == newjif)
+		return 0;
+
+	/* see can_stat_update() - this should NEVER happen! */
+	if (count > (ULONG_MAX / HZ)) {
+		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
+		       count);
+		return 99999999;
+	}
+
+	return (count * HZ) / (newjif - oldjif);
+}
+
+void can_stat_update(struct timer_list *t)
+{
+	struct net *net = timer_container_of(net, t, can.stattimer);
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	unsigned long j = jiffies; /* snapshot */
+
+	long rx_frames = atomic_long_read(&pkg_stats->rx_frames);
+	long tx_frames = atomic_long_read(&pkg_stats->tx_frames);
+	long matches = atomic_long_read(&pkg_stats->matches);
+	long rx_frames_delta = atomic_long_read(&pkg_stats->rx_frames_delta);
+	long tx_frames_delta = atomic_long_read(&pkg_stats->tx_frames_delta);
+	long matches_delta = atomic_long_read(&pkg_stats->matches_delta);
+
+	/* restart counting in timer context on user request */
+	if (user_reset)
+		can_init_stats(net);
+
+	/* restart counting on jiffies overflow */
+	if (j < pkg_stats->jiffies_init)
+		can_init_stats(net);
+
+	/* prevent overflow in calc_rate() */
+	if (rx_frames > (LONG_MAX / HZ))
+		can_init_stats(net);
+
+	/* prevent overflow in calc_rate() */
+	if (tx_frames > (LONG_MAX / HZ))
+		can_init_stats(net);
+
+	/* matches overflow - very improbable */
+	if (matches > (LONG_MAX / 100))
+		can_init_stats(net);
+
+	/* calc total values */
+	if (rx_frames)
+		pkg_stats->total_rx_match_ratio = (matches * 100) / rx_frames;
+
+	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
+					    tx_frames);
+	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
+					    rx_frames);
+
+	/* calc current values */
+	if (rx_frames_delta)
+		pkg_stats->current_rx_match_ratio =
+			(matches_delta * 100) /	rx_frames_delta;
+
+	pkg_stats->current_tx_rate = calc_rate(0, HZ, tx_frames_delta);
+	pkg_stats->current_rx_rate = calc_rate(0, HZ, rx_frames_delta);
+
+	/* check / update maximum values */
+	if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
+		pkg_stats->max_tx_rate = pkg_stats->current_tx_rate;
+
+	if (pkg_stats->max_rx_rate < pkg_stats->current_rx_rate)
+		pkg_stats->max_rx_rate = pkg_stats->current_rx_rate;
+
+	if (pkg_stats->max_rx_match_ratio < pkg_stats->current_rx_match_ratio)
+		pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
+
+	/* clear values for 'current rate' calculation */
+	atomic_long_set(&pkg_stats->tx_frames_delta, 0);
+	atomic_long_set(&pkg_stats->rx_frames_delta, 0);
+	atomic_long_set(&pkg_stats->matches_delta, 0);
+
+	/* restart timer (one second) */
+	mod_timer(&net->can.stattimer, round_jiffies(jiffies + HZ));
+}
+
+/*
+ * proc read functions
+ */
+
+static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
+			      struct net_device *dev)
+{
+	struct receiver *r;
+
+	hlist_for_each_entry_rcu(r, rx_list, list) {
+		char *fmt = (r->can_id & CAN_EFF_FLAG)?
+			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
+			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
+
+		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
+			   r->func, r->data, atomic_long_read(&r->matches),
+			   r->ident);
+	}
+}
+
+static void can_print_recv_banner(struct seq_file *m)
+{
+	/*
+	 *                  can1.  00000000  00000000  00000000
+	 *                 .......          0  tp20
+	 */
+	if (IS_ENABLED(CONFIG_64BIT))
+		seq_puts(m, "  device   can_id   can_mask      function          userdata       matches  ident\n");
+	else
+		seq_puts(m, "  device   can_id   can_mask  function  userdata   matches  ident\n");
+}
+
+static int can_stats_proc_show(struct seq_file *m, void *v)
+{
+	struct net *net = m->private;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+
+	seq_putc(m, '\n');
+	seq_printf(m, " %8ld transmitted frames (TXF)\n",
+		   atomic_long_read(&pkg_stats->tx_frames));
+	seq_printf(m, " %8ld received frames (RXF)\n",
+		   atomic_long_read(&pkg_stats->rx_frames));
+	seq_printf(m, " %8ld matched frames (RXMF)\n",
+		   atomic_long_read(&pkg_stats->matches));
+
+	seq_putc(m, '\n');
+
+	if (net->can.stattimer.function == can_stat_update) {
+		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
+				pkg_stats->total_rx_match_ratio);
+
+		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
+				pkg_stats->total_tx_rate);
+		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
+				pkg_stats->total_rx_rate);
+
+		seq_putc(m, '\n');
+
+		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
+				pkg_stats->current_rx_match_ratio);
+
+		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
+				pkg_stats->current_tx_rate);
+		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
+				pkg_stats->current_rx_rate);
+
+		seq_putc(m, '\n');
+
+		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
+				pkg_stats->max_rx_match_ratio);
+
+		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
+				pkg_stats->max_tx_rate);
+		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
+				pkg_stats->max_rx_rate);
+
+		seq_putc(m, '\n');
+	}
+
+	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
+			rcv_lists_stats->rcv_entries);
+	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
+			rcv_lists_stats->rcv_entries_max);
+
+	if (rcv_lists_stats->stats_reset)
+		seq_printf(m, "\n %8ld statistic resets (STR)\n",
+				rcv_lists_stats->stats_reset);
+
+	if (rcv_lists_stats->user_reset)
+		seq_printf(m, " %8ld user statistic resets (USTR)\n",
+				rcv_lists_stats->user_reset);
+
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static int can_reset_stats_proc_show(struct seq_file *m, void *v)
+{
+	struct net *net = m->private;
+	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
+	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
+
+	user_reset = 1;
+
+	if (net->can.stattimer.function == can_stat_update) {
+		seq_printf(m, "Scheduled statistic reset #%ld.\n",
+				rcv_lists_stats->stats_reset + 1);
+	} else {
+		if (pkg_stats->jiffies_init != jiffies)
+			can_init_stats(net);
+
+		seq_printf(m, "Performed statistic reset #%ld.\n",
+				rcv_lists_stats->stats_reset);
+	}
+	return 0;
+}
+
+static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
+					     struct net_device *dev,
+					     struct can_dev_rcv_lists *dev_rcv_lists)
+{
+	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
+		can_print_recv_banner(m);
+		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
+	} else
+		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
+
+}
+
+static int can_rcvlist_proc_show(struct seq_file *m, void *v)
+{
+	/* double cast to prevent GCC warning */
+	int idx = (int)(long)pde_data(m->file->f_inode);
+	struct net_device *dev;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct net *net = m->private;
+
+	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
+
+	rcu_read_lock();
+
+	/* receive list for 'all' CAN devices (dev == NULL) */
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
+
+	/* receive list for registered CAN devices */
+	for_each_netdev_rcu(net, dev) {
+		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+		if (can_ml)
+			can_rcvlist_proc_show_one(m, idx, dev,
+						  &can_ml->dev_rcv_lists);
+	}
+
+	rcu_read_unlock();
+
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static inline void can_rcvlist_proc_show_array(struct seq_file *m,
+					       struct net_device *dev,
+					       struct hlist_head *rcv_array,
+					       unsigned int rcv_array_sz)
+{
+	unsigned int i;
+	int all_empty = 1;
+
+	/* check whether at least one list is non-empty */
+	for (i = 0; i < rcv_array_sz; i++)
+		if (!hlist_empty(&rcv_array[i])) {
+			all_empty = 0;
+			break;
+		}
+
+	if (!all_empty) {
+		can_print_recv_banner(m);
+		for (i = 0; i < rcv_array_sz; i++) {
+			if (!hlist_empty(&rcv_array[i]))
+				can_print_rcvlist(m, &rcv_array[i], dev);
+		}
+	} else
+		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
+}
+
+static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
+{
+	struct net_device *dev;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct net *net = m->private;
+
+	/* RX_SFF */
+	seq_puts(m, "\nreceive list 'rx_sff':\n");
+
+	rcu_read_lock();
+
+	/* sff receive list for 'all' CAN devices (dev == NULL) */
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
+				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
+
+	/* sff receive list for registered CAN devices */
+	for_each_netdev_rcu(net, dev) {
+		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+		if (can_ml) {
+			dev_rcv_lists = &can_ml->dev_rcv_lists;
+			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
+						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
+		}
+	}
+
+	rcu_read_unlock();
+
+	seq_putc(m, '\n');
+	return 0;
+}
+
+static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
+{
+	struct net_device *dev;
+	struct can_dev_rcv_lists *dev_rcv_lists;
+	struct net *net = m->private;
+
+	/* RX_EFF */
+	seq_puts(m, "\nreceive list 'rx_eff':\n");
+
+	rcu_read_lock();
+
+	/* eff receive list for 'all' CAN devices (dev == NULL) */
+	dev_rcv_lists = net->can.rx_alldev_list;
+	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
+				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
+
+	/* eff receive list for registered CAN devices */
+	for_each_netdev_rcu(net, dev) {
+		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+		if (can_ml) {
+			dev_rcv_lists = &can_ml->dev_rcv_lists;
+			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
+						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
+		}
+	}
+
+	rcu_read_unlock();
+
+	seq_putc(m, '\n');
+	return 0;
+}
+
+/*
+ * can_init_proc - create main CAN proc directory and procfs entries
+ */
+void can_init_proc(struct net *net)
+{
+	/* create /proc/net/can directory */
+	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
+
+	if (!net->can.proc_dir) {
+		printk(KERN_INFO "can: failed to create /proc/net/can . "
+			   "CONFIG_PROC_FS missing?\n");
+		return;
+	}
+
+	/* own procfs entries from the AF_CAN core */
+	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
+			net->can.proc_dir, can_stats_proc_show, NULL);
+	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
+			0644, net->can.proc_dir, can_reset_stats_proc_show,
+			NULL);
+	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
+			0644, net->can.proc_dir, can_rcvlist_proc_show,
+			(void *)RX_ERR);
+	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
+			0644, net->can.proc_dir, can_rcvlist_proc_show,
+			(void *)RX_ALL);
+	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
+			0644, net->can.proc_dir, can_rcvlist_proc_show,
+			(void *)RX_FIL);
+	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
+			0644, net->can.proc_dir, can_rcvlist_proc_show,
+			(void *)RX_INV);
+	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
+			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
+	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
+			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
+}
+
+/*
+ * can_remove_proc - remove procfs entries and main CAN proc directory
+ */
+void can_remove_proc(struct net *net)
+{
+	if (!net->can.proc_dir)
+		return;
+
+	if (net->can.pde_stats)
+		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
+
+	if (net->can.pde_reset_stats)
+		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_err)
+		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_all)
+		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_fil)
+		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_inv)
+		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_eff)
+		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
+
+	if (net->can.pde_rcvlist_sff)
+		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
+
+	remove_proc_entry("can", net->proc_net);
+}
diff --git a/net/can/raw.c b/net/can/raw.c
new file mode 100644
index 000000000..82d9c0499
--- /dev/null
+++ b/net/can/raw.c
@@ -0,0 +1,1136 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/* raw.c - Raw sockets for protocol family CAN
+ *
+ * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
+ * 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 Volkswagen nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
+ * OWNER 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 <linux/module.h>
+#include <linux/init.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/can-ml.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/raw.h>
+#include <net/can.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+MODULE_DESCRIPTION("PF_CAN raw protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Urs Thuermann <urs.thuermann@volkswagen.de>");
+MODULE_ALIAS("can-proto-1");
+
+#define RAW_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_ifindex)
+
+#define MASK_ALL 0
+
+/* A raw socket has a list of can_filters attached to it, each receiving
+ * the CAN frames matching that filter.  If the filter list is empty,
+ * no CAN frames will be received by the socket.  The default after
+ * opening the socket, is to have one filter which receives all frames.
+ * The filter list is allocated dynamically with the exception of the
+ * list containing only one item.  This common case is optimized by
+ * storing the single filter in dfilter, to avoid using dynamic memory.
+ */
+
+struct uniqframe {
+	const struct sk_buff *skb;
+	u32 hash;
+	unsigned int join_rx_count;
+};
+
+struct raw_sock {
+	struct sock sk;
+	struct net_device *dev;
+	netdevice_tracker dev_tracker;
+	struct list_head notifier;
+	int ifindex;
+	unsigned int bound:1;
+	unsigned int loopback:1;
+	unsigned int recv_own_msgs:1;
+	unsigned int fd_frames:1;
+	unsigned int xl_frames:1;
+	unsigned int join_filters:1;
+	struct can_raw_vcid_options raw_vcid_opts;
+	canid_t tx_vcid_shifted;
+	canid_t rx_vcid_shifted;
+	canid_t rx_vcid_mask_shifted;
+	can_err_mask_t err_mask;
+	int count;                 /* number of active filters */
+	struct can_filter dfilter; /* default/single filter */
+	struct can_filter *filter; /* pointer to filter(s) */
+	struct uniqframe __percpu *uniq;
+};
+
+static LIST_HEAD(raw_notifier_list);
+static DEFINE_SPINLOCK(raw_notifier_lock);
+static struct raw_sock *raw_busy_notifier;
+
+/* Return pointer to store the extra msg flags for raw_recvmsg().
+ * We use the space of one unsigned int beyond the 'struct sockaddr_can'
+ * in skb->cb.
+ */
+static inline unsigned int *raw_flags(struct sk_buff *skb)
+{
+	sock_skb_cb_check_size(sizeof(struct sockaddr_can) +
+			       sizeof(unsigned int));
+
+	/* return pointer after struct sockaddr_can */
+	return (unsigned int *)(&((struct sockaddr_can *)skb->cb)[1]);
+}
+
+static inline struct raw_sock *raw_sk(const struct sock *sk)
+{
+	return (struct raw_sock *)sk;
+}
+
+static void raw_rcv(struct sk_buff *oskb, void *data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct raw_sock *ro = raw_sk(sk);
+	enum skb_drop_reason reason;
+	struct sockaddr_can *addr;
+	struct sk_buff *skb;
+	unsigned int *pflags;
+
+	/* check the received tx sock reference */
+	if (!ro->recv_own_msgs && oskb->sk == sk)
+		return;
+
+	/* make sure to not pass oversized frames to the socket */
+	if (!ro->fd_frames && can_is_canfd_skb(oskb))
+		return;
+
+	if (can_is_canxl_skb(oskb)) {
+		struct canxl_frame *cxl = (struct canxl_frame *)oskb->data;
+
+		/* make sure to not pass oversized frames to the socket */
+		if (!ro->xl_frames)
+			return;
+
+		/* filter CAN XL VCID content */
+		if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_RX_FILTER) {
+			/* apply VCID filter if user enabled the filter */
+			if ((cxl->prio & ro->rx_vcid_mask_shifted) !=
+			    (ro->rx_vcid_shifted & ro->rx_vcid_mask_shifted))
+				return;
+		} else {
+			/* no filter => do not forward VCID tagged frames */
+			if (cxl->prio & CANXL_VCID_MASK)
+				return;
+		}
+	}
+
+	/* eliminate multiple filter matches for the same skb */
+	if (this_cpu_ptr(ro->uniq)->skb == oskb &&
+	    this_cpu_ptr(ro->uniq)->hash == oskb->hash) {
+		if (!ro->join_filters)
+			return;
+
+		this_cpu_inc(ro->uniq->join_rx_count);
+		/* drop frame until all enabled filters matched */
+		if (this_cpu_ptr(ro->uniq)->join_rx_count < ro->count)
+			return;
+	} else {
+		this_cpu_ptr(ro->uniq)->skb = oskb;
+		this_cpu_ptr(ro->uniq)->hash = oskb->hash;
+		this_cpu_ptr(ro->uniq)->join_rx_count = 1;
+		/* drop first frame to check all enabled filters? */
+		if (ro->join_filters && ro->count > 1)
+			return;
+	}
+
+	/* clone the given skb to be able to enqueue it into the rcv queue */
+	skb = skb_clone(oskb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	/* Put the datagram to the queue so that raw_recvmsg() can get
+	 * it from there. We need to pass the interface index to
+	 * raw_recvmsg(). We pass a whole struct sockaddr_can in
+	 * skb->cb containing the interface index.
+	 */
+
+	sock_skb_cb_check_size(sizeof(struct sockaddr_can));
+	addr = (struct sockaddr_can *)skb->cb;
+	memset(addr, 0, sizeof(*addr));
+	addr->can_family = AF_CAN;
+	addr->can_ifindex = skb->dev->ifindex;
+
+	/* add CAN specific message flags for raw_recvmsg() */
+	pflags = raw_flags(skb);
+	*pflags = 0;
+	if (oskb->sk)
+		*pflags |= MSG_DONTROUTE;
+	if (oskb->sk == sk)
+		*pflags |= MSG_CONFIRM;
+
+	reason = sock_queue_rcv_skb_reason(sk, skb);
+	if (reason)
+		sk_skb_reason_drop(sk, skb, reason);
+}
+
+static int raw_enable_filters(struct net *net, struct net_device *dev,
+			      struct sock *sk, struct can_filter *filter,
+			      int count)
+{
+	int err = 0;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		err = can_rx_register(net, dev, filter[i].can_id,
+				      filter[i].can_mask,
+				      raw_rcv, sk, "raw", sk);
+		if (err) {
+			/* clean up successfully registered filters */
+			while (--i >= 0)
+				can_rx_unregister(net, dev, filter[i].can_id,
+						  filter[i].can_mask,
+						  raw_rcv, sk);
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int raw_enable_errfilter(struct net *net, struct net_device *dev,
+				struct sock *sk, can_err_mask_t err_mask)
+{
+	int err = 0;
+
+	if (err_mask)
+		err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
+				      raw_rcv, sk, "raw", sk);
+
+	return err;
+}
+
+static void raw_disable_filters(struct net *net, struct net_device *dev,
+				struct sock *sk, struct can_filter *filter,
+				int count)
+{
+	int i;
+
+	for (i = 0; i < count; i++)
+		can_rx_unregister(net, dev, filter[i].can_id,
+				  filter[i].can_mask, raw_rcv, sk);
+}
+
+static inline void raw_disable_errfilter(struct net *net,
+					 struct net_device *dev,
+					 struct sock *sk,
+					 can_err_mask_t err_mask)
+
+{
+	if (err_mask)
+		can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
+				  raw_rcv, sk);
+}
+
+static inline void raw_disable_allfilters(struct net *net,
+					  struct net_device *dev,
+					  struct sock *sk)
+{
+	struct raw_sock *ro = raw_sk(sk);
+
+	raw_disable_filters(net, dev, sk, ro->filter, ro->count);
+	raw_disable_errfilter(net, dev, sk, ro->err_mask);
+}
+
+static int raw_enable_allfilters(struct net *net, struct net_device *dev,
+				 struct sock *sk)
+{
+	struct raw_sock *ro = raw_sk(sk);
+	int err;
+
+	err = raw_enable_filters(net, dev, sk, ro->filter, ro->count);
+	if (!err) {
+		err = raw_enable_errfilter(net, dev, sk, ro->err_mask);
+		if (err)
+			raw_disable_filters(net, dev, sk, ro->filter,
+					    ro->count);
+	}
+
+	return err;
+}
+
+static void raw_notify(struct raw_sock *ro, unsigned long msg,
+		       struct net_device *dev)
+{
+	struct sock *sk = &ro->sk;
+
+	if (!net_eq(dev_net(dev), sock_net(sk)))
+		return;
+
+	if (ro->dev != dev)
+		return;
+
+	switch (msg) {
+	case NETDEV_UNREGISTER:
+		lock_sock(sk);
+		/* remove current filters & unregister */
+		if (ro->bound) {
+			raw_disable_allfilters(dev_net(dev), dev, sk);
+			netdev_put(dev, &ro->dev_tracker);
+		}
+
+		if (ro->count > 1)
+			kfree(ro->filter);
+
+		ro->ifindex = 0;
+		ro->bound = 0;
+		ro->dev = NULL;
+		ro->count = 0;
+		release_sock(sk);
+
+		sk->sk_err = ENODEV;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+		break;
+
+	case NETDEV_DOWN:
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+		break;
+	}
+}
+
+static int raw_notifier(struct notifier_block *nb, unsigned long msg,
+			void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (dev->type != ARPHRD_CAN)
+		return NOTIFY_DONE;
+	if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
+		return NOTIFY_DONE;
+	if (unlikely(raw_busy_notifier)) /* Check for reentrant bug. */
+		return NOTIFY_DONE;
+
+	spin_lock(&raw_notifier_lock);
+	list_for_each_entry(raw_busy_notifier, &raw_notifier_list, notifier) {
+		spin_unlock(&raw_notifier_lock);
+		raw_notify(raw_busy_notifier, msg, dev);
+		spin_lock(&raw_notifier_lock);
+	}
+	raw_busy_notifier = NULL;
+	spin_unlock(&raw_notifier_lock);
+	return NOTIFY_DONE;
+}
+
+static void raw_sock_destruct(struct sock *sk)
+{
+	struct raw_sock *ro = raw_sk(sk);
+
+	free_percpu(ro->uniq);
+	can_sock_destruct(sk);
+}
+
+static int raw_init(struct sock *sk)
+{
+	struct raw_sock *ro = raw_sk(sk);
+
+	ro->bound            = 0;
+	ro->ifindex          = 0;
+	ro->dev              = NULL;
+
+	/* set default filter to single entry dfilter */
+	ro->dfilter.can_id   = 0;
+	ro->dfilter.can_mask = MASK_ALL;
+	ro->filter           = &ro->dfilter;
+	ro->count            = 1;
+
+	/* set default loopback behaviour */
+	ro->loopback         = 1;
+	ro->recv_own_msgs    = 0;
+	ro->fd_frames        = 0;
+	ro->xl_frames        = 0;
+	ro->join_filters     = 0;
+
+	/* alloc_percpu provides zero'ed memory */
+	ro->uniq = alloc_percpu(struct uniqframe);
+	if (unlikely(!ro->uniq))
+		return -ENOMEM;
+
+	sk->sk_destruct = raw_sock_destruct;
+
+	/* set notifier */
+	spin_lock(&raw_notifier_lock);
+	list_add_tail(&ro->notifier, &raw_notifier_list);
+	spin_unlock(&raw_notifier_lock);
+
+	return 0;
+}
+
+static int raw_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro;
+	struct net *net;
+
+	if (!sk)
+		return 0;
+
+	ro = raw_sk(sk);
+	net = sock_net(sk);
+
+	spin_lock(&raw_notifier_lock);
+	while (raw_busy_notifier == ro) {
+		spin_unlock(&raw_notifier_lock);
+		schedule_timeout_uninterruptible(1);
+		spin_lock(&raw_notifier_lock);
+	}
+	list_del(&ro->notifier);
+	spin_unlock(&raw_notifier_lock);
+
+	rtnl_lock();
+	lock_sock(sk);
+
+	/* remove current filters & unregister */
+	if (ro->bound) {
+		if (ro->dev) {
+			raw_disable_allfilters(dev_net(ro->dev), ro->dev, sk);
+			netdev_put(ro->dev, &ro->dev_tracker);
+		} else {
+			raw_disable_allfilters(net, NULL, sk);
+		}
+	}
+
+	if (ro->count > 1)
+		kfree(ro->filter);
+
+	ro->ifindex = 0;
+	ro->bound = 0;
+	ro->dev = NULL;
+	ro->count = 0;
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	release_sock(sk);
+	rtnl_unlock();
+
+	sock_prot_inuse_add(net, sk->sk_prot, -1);
+	sock_put(sk);
+
+	return 0;
+}
+
+static int raw_bind(struct socket *sock, struct sockaddr_unsized *uaddr, int len)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
+	struct net_device *dev = NULL;
+	int ifindex;
+	int err = 0;
+	int notify_enetdown = 0;
+
+	if (len < RAW_MIN_NAMELEN)
+		return -EINVAL;
+	if (addr->can_family != AF_CAN)
+		return -EINVAL;
+
+	rtnl_lock();
+	lock_sock(sk);
+
+	if (ro->bound && addr->can_ifindex == ro->ifindex)
+		goto out;
+
+	if (addr->can_ifindex) {
+		dev = dev_get_by_index(sock_net(sk), addr->can_ifindex);
+		if (!dev) {
+			err = -ENODEV;
+			goto out;
+		}
+		if (dev->type != ARPHRD_CAN) {
+			err = -ENODEV;
+			goto out_put_dev;
+		}
+
+		if (!(dev->flags & IFF_UP))
+			notify_enetdown = 1;
+
+		ifindex = dev->ifindex;
+
+		/* filters set by default/setsockopt */
+		err = raw_enable_allfilters(sock_net(sk), dev, sk);
+		if (err)
+			goto out_put_dev;
+
+	} else {
+		ifindex = 0;
+
+		/* filters set by default/setsockopt */
+		err = raw_enable_allfilters(sock_net(sk), NULL, sk);
+	}
+
+	if (!err) {
+		if (ro->bound) {
+			/* unregister old filters */
+			if (ro->dev) {
+				raw_disable_allfilters(dev_net(ro->dev),
+						       ro->dev, sk);
+				/* drop reference to old ro->dev */
+				netdev_put(ro->dev, &ro->dev_tracker);
+			} else {
+				raw_disable_allfilters(sock_net(sk), NULL, sk);
+			}
+		}
+		ro->ifindex = ifindex;
+		ro->bound = 1;
+		/* bind() ok -> hold a reference for new ro->dev */
+		ro->dev = dev;
+		if (ro->dev)
+			netdev_hold(ro->dev, &ro->dev_tracker, GFP_KERNEL);
+	}
+
+out_put_dev:
+	/* remove potential reference from dev_get_by_index() */
+	dev_put(dev);
+out:
+	release_sock(sk);
+	rtnl_unlock();
+
+	if (notify_enetdown) {
+		sk->sk_err = ENETDOWN;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk_error_report(sk);
+	}
+
+	return err;
+}
+
+static int raw_getname(struct socket *sock, struct sockaddr *uaddr,
+		       int peer)
+{
+	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
+
+	if (peer)
+		return -EOPNOTSUPP;
+
+	memset(addr, 0, RAW_MIN_NAMELEN);
+	addr->can_family  = AF_CAN;
+	addr->can_ifindex = ro->ifindex;
+
+	return RAW_MIN_NAMELEN;
+}
+
+static int raw_setsockopt_locked(struct socket *sock, int optname,
+				 sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
+	struct can_filter *filter = NULL;  /* dyn. alloc'ed filters */
+	struct can_filter sfilter;         /* single filter */
+	struct net_device *dev = NULL;
+	can_err_mask_t err_mask = 0;
+	int count = 0;
+	int flag;
+	int err = 0;
+
+	switch (optname) {
+	case CAN_RAW_FILTER:
+		if (optlen % sizeof(struct can_filter) != 0)
+			return -EINVAL;
+
+		if (optlen > CAN_RAW_FILTER_MAX * sizeof(struct can_filter))
+			return -EINVAL;
+
+		count = optlen / sizeof(struct can_filter);
+
+		if (count > 1) {
+			/* filter does not fit into dfilter => alloc space */
+			filter = memdup_sockptr(optval, optlen);
+			if (IS_ERR(filter))
+				return PTR_ERR(filter);
+		} else if (count == 1) {
+			if (copy_from_sockptr(&sfilter, optval, sizeof(sfilter)))
+				return -EFAULT;
+		}
+
+		dev = ro->dev;
+		if (ro->bound && dev && dev->reg_state != NETREG_REGISTERED) {
+			if (count > 1)
+				kfree(filter);
+			return -ENODEV;
+		}
+
+		if (ro->bound) {
+			/* (try to) register the new filters */
+			if (count == 1)
+				err = raw_enable_filters(sock_net(sk), dev, sk,
+							 &sfilter, 1);
+			else
+				err = raw_enable_filters(sock_net(sk), dev, sk,
+							 filter, count);
+			if (err) {
+				if (count > 1)
+					kfree(filter);
+				return err;
+			}
+
+			/* remove old filter registrations */
+			raw_disable_filters(sock_net(sk), dev, sk, ro->filter,
+					    ro->count);
+		}
+
+		/* remove old filter space */
+		if (ro->count > 1)
+			kfree(ro->filter);
+
+		/* link new filters to the socket */
+		if (count == 1) {
+			/* copy filter data for single filter */
+			ro->dfilter = sfilter;
+			filter = &ro->dfilter;
+		}
+		ro->filter = filter;
+		ro->count  = count;
+		break;
+
+	case CAN_RAW_ERR_FILTER:
+		if (optlen != sizeof(err_mask))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&err_mask, optval, optlen))
+			return -EFAULT;
+
+		err_mask &= CAN_ERR_MASK;
+
+		dev = ro->dev;
+		if (ro->bound && dev && dev->reg_state != NETREG_REGISTERED)
+			return -ENODEV;
+
+		/* remove current error mask */
+		if (ro->bound) {
+			/* (try to) register the new err_mask */
+			err = raw_enable_errfilter(sock_net(sk), dev, sk,
+						   err_mask);
+
+			if (err)
+				return err;
+
+			/* remove old err_mask registration */
+			raw_disable_errfilter(sock_net(sk), dev, sk,
+					      ro->err_mask);
+		}
+
+		/* link new err_mask to the socket */
+		ro->err_mask = err_mask;
+		break;
+
+	case CAN_RAW_LOOPBACK:
+		if (optlen != sizeof(flag))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&flag, optval, optlen))
+			return -EFAULT;
+
+		ro->loopback = !!flag;
+		break;
+
+	case CAN_RAW_RECV_OWN_MSGS:
+		if (optlen != sizeof(flag))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&flag, optval, optlen))
+			return -EFAULT;
+
+		ro->recv_own_msgs = !!flag;
+		break;
+
+	case CAN_RAW_FD_FRAMES:
+		if (optlen != sizeof(flag))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&flag, optval, optlen))
+			return -EFAULT;
+
+		/* Enabling CAN XL includes CAN FD */
+		if (ro->xl_frames && !flag)
+			return -EINVAL;
+
+		ro->fd_frames = !!flag;
+		break;
+
+	case CAN_RAW_XL_FRAMES:
+		if (optlen != sizeof(flag))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&flag, optval, optlen))
+			return -EFAULT;
+
+		ro->xl_frames = !!flag;
+
+		/* Enabling CAN XL includes CAN FD */
+		if (ro->xl_frames)
+			ro->fd_frames = ro->xl_frames;
+		break;
+
+	case CAN_RAW_XL_VCID_OPTS:
+		if (optlen != sizeof(ro->raw_vcid_opts))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&ro->raw_vcid_opts, optval, optlen))
+			return -EFAULT;
+
+		/* prepare 32 bit values for handling in hot path */
+		ro->tx_vcid_shifted = ro->raw_vcid_opts.tx_vcid << CANXL_VCID_OFFSET;
+		ro->rx_vcid_shifted = ro->raw_vcid_opts.rx_vcid << CANXL_VCID_OFFSET;
+		ro->rx_vcid_mask_shifted = ro->raw_vcid_opts.rx_vcid_mask << CANXL_VCID_OFFSET;
+		break;
+
+	case CAN_RAW_JOIN_FILTERS:
+		if (optlen != sizeof(flag))
+			return -EINVAL;
+
+		if (copy_from_sockptr(&flag, optval, optlen))
+			return -EFAULT;
+
+		ro->join_filters = !!flag;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+	return err;
+}
+
+static int raw_setsockopt(struct socket *sock, int level, int optname,
+			  sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	int err;
+
+	if (level != SOL_CAN_RAW)
+		return -EINVAL;
+
+	rtnl_lock();
+	lock_sock(sk);
+
+	err = raw_setsockopt_locked(sock, optname, optval, optlen);
+
+	release_sock(sk);
+	rtnl_unlock();
+
+	return err;
+}
+
+static int raw_getsockopt(struct socket *sock, int level, int optname,
+			  sockopt_t *opt)
+{
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
+	int flag;
+	int len;
+	void *val;
+
+	if (level != SOL_CAN_RAW)
+		return -EINVAL;
+	len = opt->optlen;
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case CAN_RAW_FILTER: {
+		int err = 0;
+
+		lock_sock(sk);
+		if (ro->count > 0) {
+			int fsize = ro->count * sizeof(struct can_filter);
+
+			/* user space buffer to small for filter list? */
+			if (len < fsize) {
+				/* return -ERANGE and needed space in optlen */
+				err = -ERANGE;
+				opt->optlen = fsize;
+			} else {
+				if (len > fsize)
+					len = fsize;
+				if (copy_to_iter(ro->filter, len,
+						 &opt->iter_out) != len)
+					err = -EFAULT;
+			}
+		} else {
+			len = 0;
+		}
+		release_sock(sk);
+
+		if (!err)
+			opt->optlen = len;
+		return err;
+	}
+	case CAN_RAW_ERR_FILTER:
+		if (len > sizeof(can_err_mask_t))
+			len = sizeof(can_err_mask_t);
+		val = &ro->err_mask;
+		break;
+
+	case CAN_RAW_LOOPBACK:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		flag = ro->loopback;
+		val = &flag;
+		break;
+
+	case CAN_RAW_RECV_OWN_MSGS:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		flag = ro->recv_own_msgs;
+		val = &flag;
+		break;
+
+	case CAN_RAW_FD_FRAMES:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		flag = ro->fd_frames;
+		val = &flag;
+		break;
+
+	case CAN_RAW_XL_FRAMES:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		flag = ro->xl_frames;
+		val = &flag;
+		break;
+
+	case CAN_RAW_XL_VCID_OPTS: {
+		int err = 0;
+
+		/* user space buffer to small for VCID opts? */
+		if (len < sizeof(ro->raw_vcid_opts)) {
+			/* return -ERANGE and needed space in optlen */
+			err = -ERANGE;
+			opt->optlen = sizeof(ro->raw_vcid_opts);
+		} else {
+			if (len > sizeof(ro->raw_vcid_opts))
+				len = sizeof(ro->raw_vcid_opts);
+			if (copy_to_iter(&ro->raw_vcid_opts, len,
+					 &opt->iter_out) != len)
+				err = -EFAULT;
+		}
+		if (!err)
+			opt->optlen = len;
+		return err;
+	}
+	case CAN_RAW_JOIN_FILTERS:
+		if (len > sizeof(int))
+			len = sizeof(int);
+		flag = ro->join_filters;
+		val = &flag;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	opt->optlen = len;
+	if (copy_to_iter(val, len, &opt->iter_out) != len)
+		return -EFAULT;
+	return 0;
+}
+
+static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb)
+{
+	struct canxl_frame *cxl = (struct canxl_frame *)skb->data;
+
+	/* sanitize non CAN XL bits */
+	cxl->prio &= (CANXL_PRIO_MASK | CANXL_VCID_MASK);
+
+	/* clear VCID in CAN XL frame if pass through is disabled */
+	if (!(ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_PASS))
+		cxl->prio &= CANXL_PRIO_MASK;
+
+	/* set VCID in CAN XL frame if enabled */
+	if (ro->raw_vcid_opts.flags & CAN_RAW_XL_VCID_TX_SET) {
+		cxl->prio &= CANXL_PRIO_MASK;
+		cxl->prio |= ro->tx_vcid_shifted;
+	}
+}
+
+static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	/* Classical CAN */
+	if (can_is_can_skb(skb) && can_cap_enabled(dev, CAN_CAP_CC))
+		return CAN_MTU;
+
+	/* CAN FD */
+	if (ro->fd_frames && can_is_canfd_skb(skb) &&
+	    can_cap_enabled(dev, CAN_CAP_FD))
+		return CANFD_MTU;
+
+	/* CAN XL */
+	if (ro->xl_frames && can_is_canxl_skb(skb) &&
+	    can_cap_enabled(dev, CAN_CAP_XL))
+		return CANXL_MTU;
+
+	return 0;
+}
+
+static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct raw_sock *ro = raw_sk(sk);
+	struct sockcm_cookie sockc;
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+	struct net_device *dev;
+	unsigned int txmtu;
+	int ifindex;
+	int err = -EINVAL;
+
+	/* check for valid CAN frame sizes */
+	if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU)
+		return -EINVAL;
+
+	if (msg->msg_name) {
+		DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
+
+		if (msg->msg_namelen < RAW_MIN_NAMELEN)
+			return -EINVAL;
+
+		if (addr->can_family != AF_CAN)
+			return -EINVAL;
+
+		ifindex = addr->can_ifindex;
+	} else {
+		ifindex = ro->ifindex;
+	}
+
+	dev = dev_get_by_index(sock_net(sk), ifindex);
+	if (!dev)
+		return -ENXIO;
+
+	/* no sending on a CAN device in read-only mode */
+	if (can_cap_enabled(dev, CAN_CAP_RO)) {
+		err = -EACCES;
+		goto put_dev;
+	}
+
+	skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
+				  &err);
+	if (!skb)
+		goto put_dev;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		err = -ENOMEM;
+		goto put_dev;
+	}
+
+	csx->can_iif = dev->ifindex;
+
+	/* fill the skb before testing for valid CAN frames */
+	err = memcpy_from_msg(skb_put(skb, size), msg, size);
+	if (err < 0)
+		goto free_skb;
+
+	err = -EINVAL;
+
+	/* check for valid CAN (CC/FD/XL) frame content */
+	txmtu = raw_check_txframe(ro, skb, dev);
+	if (!txmtu)
+		goto free_skb;
+
+	/* only CANXL: clear/forward/set VCID value */
+	if (txmtu == CANXL_MTU)
+		raw_put_canxl_vcid(ro, skb);
+
+	sockcm_init(&sockc, sk);
+	if (msg->msg_controllen) {
+		err = sock_cmsg_send(sk, msg, &sockc);
+		if (unlikely(err))
+			goto free_skb;
+	}
+
+	skb->dev = dev;
+	skb->priority = sockc.priority;
+	skb->mark = sockc.mark;
+	skb->tstamp = sockc.transmit_time;
+
+	skb_setup_tx_timestamp(skb, &sockc);
+
+	err = can_send(skb, ro->loopback);
+
+	dev_put(dev);
+
+	if (err)
+		goto send_failed;
+
+	return size;
+
+free_skb:
+	kfree_skb(skb);
+put_dev:
+	dev_put(dev);
+send_failed:
+	return err;
+}
+
+static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		       int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sk_buff *skb;
+	int err = 0;
+
+	if (flags & MSG_ERRQUEUE)
+		return sock_recv_errqueue(sk, msg, size,
+					  SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
+
+	skb = skb_recv_datagram(sk, flags, &err);
+	if (!skb)
+		return err;
+
+	if (size < skb->len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		size = skb->len;
+
+	err = memcpy_to_msg(msg, skb->data, size);
+	if (err < 0) {
+		skb_free_datagram(sk, skb);
+		return err;
+	}
+
+	sock_recv_cmsgs(msg, sk, skb);
+
+	if (msg->msg_name) {
+		__sockaddr_check_size(RAW_MIN_NAMELEN);
+		msg->msg_namelen = RAW_MIN_NAMELEN;
+		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+	}
+
+	/* assign the flags that have been recorded in raw_rcv() */
+	msg->msg_flags |= *(raw_flags(skb));
+
+	skb_free_datagram(sk, skb);
+
+	return size;
+}
+
+static int raw_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+				unsigned long arg)
+{
+	/* no ioctls for socket layer -> hand it down to NIC layer */
+	return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops raw_ops = {
+	.family        = PF_CAN,
+	.release       = raw_release,
+	.bind          = raw_bind,
+	.connect       = sock_no_connect,
+	.socketpair    = sock_no_socketpair,
+	.accept        = sock_no_accept,
+	.getname       = raw_getname,
+	.poll          = datagram_poll,
+	.ioctl         = raw_sock_no_ioctlcmd,
+	.gettstamp     = sock_gettstamp,
+	.listen        = sock_no_listen,
+	.shutdown      = sock_no_shutdown,
+	.setsockopt    = raw_setsockopt,
+	.getsockopt_iter = raw_getsockopt,
+	.sendmsg       = raw_sendmsg,
+	.recvmsg       = raw_recvmsg,
+	.mmap          = sock_no_mmap,
+};
+
+static struct proto raw_proto __read_mostly = {
+	.name       = "CAN_RAW",
+	.owner      = THIS_MODULE,
+	.obj_size   = sizeof(struct raw_sock),
+	.init       = raw_init,
+};
+
+static const struct can_proto raw_can_proto = {
+	.type       = SOCK_RAW,
+	.protocol   = CAN_RAW,
+	.ops        = &raw_ops,
+	.prot       = &raw_proto,
+};
+
+static struct notifier_block canraw_notifier = {
+	.notifier_call = raw_notifier
+};
+
+static __init int raw_module_init(void)
+{
+	int err;
+
+	pr_info("can: raw protocol\n");
+
+	err = register_netdevice_notifier(&canraw_notifier);
+	if (err)
+		return err;
+
+	err = can_proto_register(&raw_can_proto);
+	if (err < 0) {
+		pr_err("can: registration of raw protocol failed\n");
+		goto register_proto_failed;
+	}
+
+	return 0;
+
+register_proto_failed:
+	unregister_netdevice_notifier(&canraw_notifier);
+	return err;
+}
+
+static __exit void raw_module_exit(void)
+{
+	can_proto_unregister(&raw_can_proto);
+	unregister_netdevice_notifier(&canraw_notifier);
+}
+
+module_init(raw_module_init);
+module_exit(raw_module_exit);