Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

8 files changed, 2184 insertions, 0 deletions

diff --git a/net/802/Kconfig b/net/802/Kconfig
new file mode 100644
index 000000000..aaa83e888
--- /dev/null
+++ b/net/802/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config STP
+	tristate
+	select LLC
+
+config GARP
+	tristate
+	select STP
+
+config MRP
+	tristate
diff --git a/net/802/Makefile b/net/802/Makefile
new file mode 100644
index 000000000..54784f3ca
--- /dev/null
+++ b/net/802/Makefile
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux 802.x protocol layers.
+#
+
+obj-$(CONFIG_LLC)	+= psnap.o
+obj-$(CONFIG_NET_FC)	+=                 fc.o
+obj-$(CONFIG_FDDI)	+=                 fddi.o
+obj-$(CONFIG_STP)	+= stp.o
+obj-$(CONFIG_GARP)	+= garp.o
+obj-$(CONFIG_MRP)	+= mrp.o
diff --git a/net/802/fc.c b/net/802/fc.c
new file mode 100644
index 000000000..afd3d288a
--- /dev/null
+++ b/net/802/fc.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * NET3:	Fibre Channel device handling subroutines
+ *
+ *		Vineet Abraham <vma@iol.unh.edu>
+ *		v 1.0 03/22/99
+ */
+
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/fcdevice.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/net.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <net/arp.h>
+
+/*
+ *	Put the headers on a Fibre Channel packet.
+ */
+
+static int fc_header(struct sk_buff *skb, struct net_device *dev,
+		     unsigned short type,
+		     const void *daddr, const void *saddr, unsigned int len)
+{
+	struct fch_hdr *fch;
+	int hdr_len;
+
+	/*
+	 * Add the 802.2 SNAP header if IP as the IPv4 code calls
+	 * dev->hard_header directly.
+	 */
+	if (type == ETH_P_IP || type == ETH_P_ARP)
+	{
+		struct fcllc *fcllc;
+
+		hdr_len = sizeof(struct fch_hdr) + sizeof(struct fcllc);
+		fch = skb_push(skb, hdr_len);
+		fcllc = (struct fcllc *)(fch+1);
+		fcllc->dsap = fcllc->ssap = EXTENDED_SAP;
+		fcllc->llc = UI_CMD;
+		fcllc->protid[0] = fcllc->protid[1] = fcllc->protid[2] = 0x00;
+		fcllc->ethertype = htons(type);
+	}
+	else
+	{
+		hdr_len = sizeof(struct fch_hdr);
+		fch = skb_push(skb, hdr_len);
+	}
+
+	if(saddr)
+		memcpy(fch->saddr,saddr,dev->addr_len);
+	else
+		memcpy(fch->saddr,dev->dev_addr,dev->addr_len);
+
+	if(daddr)
+	{
+		memcpy(fch->daddr,daddr,dev->addr_len);
+		return hdr_len;
+	}
+	return -hdr_len;
+}
+
+static const struct header_ops fc_header_ops = {
+	.create	 = fc_header,
+};
+
+static void fc_setup(struct net_device *dev)
+{
+	dev->header_ops		= &fc_header_ops;
+	dev->type		= ARPHRD_IEEE802;
+	dev->hard_header_len	= FC_HLEN;
+	dev->mtu		= 2024;
+	dev->addr_len		= FC_ALEN;
+	dev->tx_queue_len	= 100; /* Long queues on fc */
+	dev->flags		= IFF_BROADCAST;
+
+	memset(dev->broadcast, 0xFF, FC_ALEN);
+}
+
+/**
+ * alloc_fcdev - Register fibre channel device
+ * @sizeof_priv: Size of additional driver-private structure to be allocated
+ *	for this fibre channel device
+ *
+ * Fill in the fields of the device structure with fibre channel-generic values.
+ *
+ * Constructs a new net device, complete with a private data area of
+ * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
+ * this private data area.
+ */
+struct net_device *alloc_fcdev(int sizeof_priv)
+{
+	return alloc_netdev(sizeof_priv, "fc%d", NET_NAME_UNKNOWN, fc_setup);
+}
+EXPORT_SYMBOL(alloc_fcdev);
diff --git a/net/802/fddi.c b/net/802/fddi.c
new file mode 100644
index 000000000..e26f4549e
--- /dev/null
+++ b/net/802/fddi.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		FDDI-type device handling.
+ *
+ * Version:	@(#)fddi.c	1.0.0	08/12/96
+ *
+ * Authors:	Lawrence V. Stefani, <stefani@lkg.dec.com>
+ *
+ *		fddi.c is based on previous eth.c and tr.c work by
+ *			Ross Biro
+ *			Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *			Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *			Florian La Roche, <rzsfl@rz.uni-sb.de>
+ *			Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *
+ *	Changes
+ *		Alan Cox		:	New arp/rebuild header
+ *		Maciej W. Rozycki	:	IPv6 support
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/fddidevice.h>
+#include <linux/if_ether.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <net/arp.h>
+#include <net/sock.h>
+
+/*
+ * Create the FDDI MAC header for an arbitrary protocol layer
+ *
+ * saddr=NULL	means use device source address
+ * daddr=NULL	means leave destination address (eg unresolved arp)
+ */
+
+static int fddi_header(struct sk_buff *skb, struct net_device *dev,
+		       unsigned short type,
+		       const void *daddr, const void *saddr, unsigned int len)
+{
+	int hl = FDDI_K_SNAP_HLEN;
+	struct fddihdr *fddi;
+
+	if(type != ETH_P_IP && type != ETH_P_IPV6 && type != ETH_P_ARP)
+		hl=FDDI_K_8022_HLEN-3;
+	fddi = skb_push(skb, hl);
+	fddi->fc			 = FDDI_FC_K_ASYNC_LLC_DEF;
+	if(type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP)
+	{
+		fddi->hdr.llc_snap.dsap		 = FDDI_EXTENDED_SAP;
+		fddi->hdr.llc_snap.ssap		 = FDDI_EXTENDED_SAP;
+		fddi->hdr.llc_snap.ctrl		 = FDDI_UI_CMD;
+		fddi->hdr.llc_snap.oui[0]	 = 0x00;
+		fddi->hdr.llc_snap.oui[1]	 = 0x00;
+		fddi->hdr.llc_snap.oui[2]	 = 0x00;
+		fddi->hdr.llc_snap.ethertype	 = htons(type);
+	}
+
+	/* Set the source and destination hardware addresses */
+
+	if (saddr != NULL)
+		memcpy(fddi->saddr, saddr, dev->addr_len);
+	else
+		memcpy(fddi->saddr, dev->dev_addr, dev->addr_len);
+
+	if (daddr != NULL)
+	{
+		memcpy(fddi->daddr, daddr, dev->addr_len);
+		return hl;
+	}
+
+	return -hl;
+}
+
+/*
+ * Determine the packet's protocol ID and fill in skb fields.
+ * This routine is called before an incoming packet is passed
+ * up.  It's used to fill in specific skb fields and to set
+ * the proper pointer to the start of packet data (skb->data).
+ */
+
+__be16 fddi_type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+	struct fddihdr *fddi = (struct fddihdr *)skb->data;
+	__be16 type;
+
+	/*
+	 * Set mac.raw field to point to FC byte, set data field to point
+	 * to start of packet data.  Assume 802.2 SNAP frames for now.
+	 */
+
+	skb->dev = dev;
+	skb_reset_mac_header(skb);	/* point to frame control (FC) */
+
+	if (skb->len < FDDI_K_8022_HLEN)
+		return htons(0);
+
+	if(fddi->hdr.llc_8022_1.dsap==0xe0)
+	{
+		skb_pull(skb, FDDI_K_8022_HLEN-3);
+		type = htons(ETH_P_802_2);
+	}
+	else
+	{
+		if (skb->len < FDDI_K_SNAP_HLEN)
+			return htons(0);
+		skb_pull(skb, FDDI_K_SNAP_HLEN);		/* adjust for 21 byte header */
+		type=fddi->hdr.llc_snap.ethertype;
+	}
+
+	/* Set packet type based on destination address and flag settings */
+
+	if (*fddi->daddr & 0x01)
+	{
+		if (memcmp(fddi->daddr, dev->broadcast, FDDI_K_ALEN) == 0)
+			skb->pkt_type = PACKET_BROADCAST;
+		else
+			skb->pkt_type = PACKET_MULTICAST;
+	}
+
+	else if (dev->flags & IFF_PROMISC)
+	{
+		if (memcmp(fddi->daddr, dev->dev_addr, FDDI_K_ALEN))
+			skb->pkt_type = PACKET_OTHERHOST;
+	}
+
+	/* Assume 802.2 SNAP frames, for now */
+
+	return type;
+}
+
+EXPORT_SYMBOL(fddi_type_trans);
+
+static const struct header_ops fddi_header_ops = {
+	.create		= fddi_header,
+};
+
+
+static void fddi_setup(struct net_device *dev)
+{
+	dev->header_ops		= &fddi_header_ops;
+	dev->type		= ARPHRD_FDDI;
+	dev->hard_header_len	= FDDI_K_SNAP_HLEN+3;	/* Assume 802.2 SNAP hdr len + 3 pad bytes */
+	dev->mtu		= FDDI_K_SNAP_DLEN;	/* Assume max payload of 802.2 SNAP frame */
+	dev->min_mtu		= FDDI_K_SNAP_HLEN;
+	dev->max_mtu		= FDDI_K_SNAP_DLEN;
+	dev->addr_len		= FDDI_K_ALEN;
+	dev->tx_queue_len	= 100;			/* Long queues on FDDI */
+	dev->flags		= IFF_BROADCAST | IFF_MULTICAST;
+
+	memset(dev->broadcast, 0xFF, FDDI_K_ALEN);
+}
+
+/**
+ * alloc_fddidev - Register FDDI device
+ * @sizeof_priv: Size of additional driver-private structure to be allocated
+ *	for this FDDI device
+ *
+ * Fill in the fields of the device structure with FDDI-generic values.
+ *
+ * Constructs a new net device, complete with a private data area of
+ * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
+ * this private data area.
+ */
+struct net_device *alloc_fddidev(int sizeof_priv)
+{
+	return alloc_netdev(sizeof_priv, "fddi%d", NET_NAME_UNKNOWN,
+			    fddi_setup);
+}
+EXPORT_SYMBOL(alloc_fddidev);
+
+MODULE_DESCRIPTION("Core routines for FDDI network devices");
+MODULE_LICENSE("GPL");
diff --git a/net/802/garp.c b/net/802/garp.c
new file mode 100644
index 000000000..56b934ec1
--- /dev/null
+++ b/net/802/garp.c
@@ -0,0 +1,653 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	IEEE 802.1D Generic Attribute Registration Protocol (GARP)
+ *
+ *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/llc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <net/llc.h>
+#include <net/llc_pdu.h>
+#include <net/garp.h>
+#include <linux/unaligned.h>
+
+static unsigned int garp_join_time __read_mostly = 200;
+module_param(garp_join_time, uint, 0644);
+MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)");
+MODULE_DESCRIPTION("IEEE 802.1D Generic Attribute Registration Protocol (GARP)");
+MODULE_LICENSE("GPL");
+
+static const struct garp_state_trans {
+	u8	state;
+	u8	action;
+} garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
+	[GARP_APPLICANT_VA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_AA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_AA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_QA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_QA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_LA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_VO,
+						    .action = GARP_ACTION_S_LEAVE_EMPTY },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_VP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_AA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_VO },
+	},
+	[GARP_APPLICANT_AP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_QA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_AO },
+	},
+	[GARP_APPLICANT_QP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_QO },
+	},
+	[GARP_APPLICANT_VO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_AO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_AP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_QO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+};
+
+static int garp_attr_cmp(const struct garp_attr *attr,
+			 const void *data, u8 len, u8 type)
+{
+	if (attr->type != type)
+		return attr->type - type;
+	if (attr->dlen != len)
+		return attr->dlen - len;
+	return memcmp(attr->data, data, len);
+}
+
+static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
+					  const void *data, u8 len, u8 type)
+{
+	struct rb_node *parent = app->gid.rb_node;
+	struct garp_attr *attr;
+	int d;
+
+	while (parent) {
+		attr = rb_entry(parent, struct garp_attr, node);
+		d = garp_attr_cmp(attr, data, len, type);
+		if (d > 0)
+			parent = parent->rb_left;
+		else if (d < 0)
+			parent = parent->rb_right;
+		else
+			return attr;
+	}
+	return NULL;
+}
+
+static struct garp_attr *garp_attr_create(struct garp_applicant *app,
+					  const void *data, u8 len, u8 type)
+{
+	struct rb_node *parent = NULL, **p = &app->gid.rb_node;
+	struct garp_attr *attr;
+	int d;
+
+	while (*p) {
+		parent = *p;
+		attr = rb_entry(parent, struct garp_attr, node);
+		d = garp_attr_cmp(attr, data, len, type);
+		if (d > 0)
+			p = &parent->rb_left;
+		else if (d < 0)
+			p = &parent->rb_right;
+		else {
+			/* The attribute already exists; re-use it. */
+			return attr;
+		}
+	}
+	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	if (!attr)
+		return attr;
+	attr->state = GARP_APPLICANT_VO;
+	attr->type  = type;
+	attr->dlen  = len;
+	memcpy(attr->data, data, len);
+
+	rb_link_node(&attr->node, parent, p);
+	rb_insert_color(&attr->node, &app->gid);
+	return attr;
+}
+
+static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
+{
+	rb_erase(&attr->node, &app->gid);
+	kfree(attr);
+}
+
+static void garp_attr_destroy_all(struct garp_applicant *app)
+{
+	struct rb_node *node, *next;
+	struct garp_attr *attr;
+
+	for (node = rb_first(&app->gid);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct garp_attr, node);
+		garp_attr_destroy(app, attr);
+	}
+}
+
+static int garp_pdu_init(struct garp_applicant *app)
+{
+	struct sk_buff *skb;
+	struct garp_pdu_hdr *gp;
+
+#define LLC_RESERVE	sizeof(struct llc_pdu_un)
+	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
+			GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	skb->dev = app->dev;
+	skb->protocol = htons(ETH_P_802_2);
+	skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
+
+	gp = __skb_put(skb, sizeof(*gp));
+	put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
+
+	app->pdu = skb;
+	return 0;
+}
+
+static int garp_pdu_append_end_mark(struct garp_applicant *app)
+{
+	if (skb_tailroom(app->pdu) < sizeof(u8))
+		return -1;
+	__skb_put_u8(app->pdu, GARP_END_MARK);
+	return 0;
+}
+
+static void garp_pdu_queue(struct garp_applicant *app)
+{
+	if (!app->pdu)
+		return;
+
+	garp_pdu_append_end_mark(app);
+	garp_pdu_append_end_mark(app);
+
+	llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
+			    LLC_SAP_BSPAN, LLC_PDU_CMD);
+	llc_pdu_init_as_ui_cmd(app->pdu);
+	llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
+			 app->app->proto.group_address);
+
+	skb_queue_tail(&app->queue, app->pdu);
+	app->pdu = NULL;
+}
+
+static void garp_queue_xmit(struct garp_applicant *app)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&app->queue)))
+		dev_queue_xmit(skb);
+}
+
+static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
+{
+	struct garp_msg_hdr *gm;
+
+	if (skb_tailroom(app->pdu) < sizeof(*gm))
+		return -1;
+	gm = __skb_put(app->pdu, sizeof(*gm));
+	gm->attrtype = attrtype;
+	garp_cb(app->pdu)->cur_type = attrtype;
+	return 0;
+}
+
+static int garp_pdu_append_attr(struct garp_applicant *app,
+				const struct garp_attr *attr,
+				enum garp_attr_event event)
+{
+	struct garp_attr_hdr *ga;
+	unsigned int len;
+	int err;
+again:
+	if (!app->pdu) {
+		err = garp_pdu_init(app);
+		if (err < 0)
+			return err;
+	}
+
+	if (garp_cb(app->pdu)->cur_type != attr->type) {
+		if (garp_cb(app->pdu)->cur_type &&
+		    garp_pdu_append_end_mark(app) < 0)
+			goto queue;
+		if (garp_pdu_append_msg(app, attr->type) < 0)
+			goto queue;
+	}
+
+	len = sizeof(*ga) + attr->dlen;
+	if (skb_tailroom(app->pdu) < len)
+		goto queue;
+	ga = __skb_put(app->pdu, len);
+	ga->len   = len;
+	ga->event = event;
+	memcpy(ga->data, attr->data, attr->dlen);
+	return 0;
+
+queue:
+	garp_pdu_queue(app);
+	goto again;
+}
+
+static void garp_attr_event(struct garp_applicant *app,
+			    struct garp_attr *attr, enum garp_event event)
+{
+	enum garp_applicant_state state;
+
+	state = garp_applicant_state_table[attr->state][event].state;
+	if (state == GARP_APPLICANT_INVALID)
+		return;
+
+	switch (garp_applicant_state_table[attr->state][event].action) {
+	case GARP_ACTION_NONE:
+		break;
+	case GARP_ACTION_S_JOIN_IN:
+		/* When appending the attribute fails, don't update state in
+		 * order to retry on next TRANSMIT_PDU event. */
+		if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
+			return;
+		break;
+	case GARP_ACTION_S_LEAVE_EMPTY:
+		garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
+		/* As a pure applicant, sending a leave message implies that
+		 * the attribute was unregistered and can be destroyed. */
+		garp_attr_destroy(app, attr);
+		return;
+	default:
+		WARN_ON(1);
+	}
+
+	attr->state = state;
+}
+
+int garp_request_join(const struct net_device *dev,
+		      const struct garp_application *appl,
+		      const void *data, u8 len, u8 type)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+	struct garp_attr *attr;
+
+	spin_lock_bh(&app->lock);
+	attr = garp_attr_create(app, data, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return -ENOMEM;
+	}
+	garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
+	spin_unlock_bh(&app->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(garp_request_join);
+
+void garp_request_leave(const struct net_device *dev,
+			const struct garp_application *appl,
+			const void *data, u8 len, u8 type)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+	struct garp_attr *attr;
+
+	spin_lock_bh(&app->lock);
+	attr = garp_attr_lookup(app, data, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return;
+	}
+	garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
+	spin_unlock_bh(&app->lock);
+}
+EXPORT_SYMBOL_GPL(garp_request_leave);
+
+static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
+{
+	struct rb_node *node, *next;
+	struct garp_attr *attr;
+
+	for (node = rb_first(&app->gid);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct garp_attr, node);
+		garp_attr_event(app, attr, event);
+	}
+}
+
+static void garp_join_timer_arm(struct garp_applicant *app)
+{
+	unsigned long delay;
+
+	delay = get_random_u32_below(msecs_to_jiffies(garp_join_time));
+	mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void garp_join_timer(struct timer_list *t)
+{
+	struct garp_applicant *app = timer_container_of(app, t, join_timer);
+
+	spin_lock(&app->lock);
+	garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+	garp_pdu_queue(app);
+	spin_unlock(&app->lock);
+
+	garp_queue_xmit(app);
+	garp_join_timer_arm(app);
+}
+
+static int garp_pdu_parse_end_mark(struct sk_buff *skb)
+{
+	if (!pskb_may_pull(skb, sizeof(u8)))
+		return -1;
+	if (*skb->data == GARP_END_MARK) {
+		skb_pull(skb, sizeof(u8));
+		return -1;
+	}
+	return 0;
+}
+
+static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
+			       u8 attrtype)
+{
+	const struct garp_attr_hdr *ga;
+	struct garp_attr *attr;
+	enum garp_event event;
+	unsigned int dlen;
+
+	if (!pskb_may_pull(skb, sizeof(*ga)))
+		return -1;
+	ga = (struct garp_attr_hdr *)skb->data;
+	if (ga->len < sizeof(*ga))
+		return -1;
+
+	if (!pskb_may_pull(skb, ga->len))
+		return -1;
+	ga = (struct garp_attr_hdr *)skb->data;
+	skb_pull(skb, ga->len);
+	dlen = ga->len - sizeof(*ga);
+
+	if (attrtype > app->app->maxattr)
+		return 0;
+
+	switch (ga->event) {
+	case GARP_LEAVE_ALL:
+		if (dlen != 0)
+			return -1;
+		garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
+		return 0;
+	case GARP_JOIN_EMPTY:
+		event = GARP_EVENT_R_JOIN_EMPTY;
+		break;
+	case GARP_JOIN_IN:
+		event = GARP_EVENT_R_JOIN_IN;
+		break;
+	case GARP_LEAVE_EMPTY:
+		event = GARP_EVENT_R_LEAVE_EMPTY;
+		break;
+	case GARP_EMPTY:
+		event = GARP_EVENT_R_EMPTY;
+		break;
+	default:
+		return 0;
+	}
+
+	if (dlen == 0)
+		return -1;
+	attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
+	if (attr == NULL)
+		return 0;
+	garp_attr_event(app, attr, event);
+	return 0;
+}
+
+static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
+{
+	const struct garp_msg_hdr *gm;
+	u8 attrtype;
+
+	if (!pskb_may_pull(skb, sizeof(*gm)))
+		return -1;
+	gm = (struct garp_msg_hdr *)skb->data;
+	if (gm->attrtype == 0)
+		return -1;
+	skb_pull(skb, sizeof(*gm));
+	attrtype = gm->attrtype;
+
+	while (skb->len > 0) {
+		if (garp_pdu_parse_attr(app, skb, attrtype) < 0)
+			return -1;
+		if (garp_pdu_parse_end_mark(skb) < 0)
+			break;
+	}
+	return 0;
+}
+
+static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
+			 struct net_device *dev)
+{
+	struct garp_application *appl = proto->data;
+	struct garp_port *port;
+	struct garp_applicant *app;
+	const struct garp_pdu_hdr *gp;
+
+	port = rcu_dereference(dev->garp_port);
+	if (!port)
+		goto err;
+	app = rcu_dereference(port->applicants[appl->type]);
+	if (!app)
+		goto err;
+
+	if (!pskb_may_pull(skb, sizeof(*gp)))
+		goto err;
+	gp = (struct garp_pdu_hdr *)skb->data;
+	if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
+		goto err;
+	skb_pull(skb, sizeof(*gp));
+
+	spin_lock(&app->lock);
+	while (skb->len > 0) {
+		if (garp_pdu_parse_msg(app, skb) < 0)
+			break;
+		if (garp_pdu_parse_end_mark(skb) < 0)
+			break;
+	}
+	spin_unlock(&app->lock);
+err:
+	kfree_skb(skb);
+}
+
+static int garp_init_port(struct net_device *dev)
+{
+	struct garp_port *port;
+
+	port = kzalloc_obj(*port);
+	if (!port)
+		return -ENOMEM;
+	rcu_assign_pointer(dev->garp_port, port);
+	return 0;
+}
+
+static void garp_release_port(struct net_device *dev)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	unsigned int i;
+
+	for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
+		if (rtnl_dereference(port->applicants[i]))
+			return;
+	}
+	RCU_INIT_POINTER(dev->garp_port, NULL);
+	kfree_rcu(port, rcu);
+}
+
+int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
+{
+	struct garp_applicant *app;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (!rtnl_dereference(dev->garp_port)) {
+		err = garp_init_port(dev);
+		if (err < 0)
+			goto err1;
+	}
+
+	err = -ENOMEM;
+	app = kzalloc_obj(*app);
+	if (!app)
+		goto err2;
+
+	err = dev_mc_add(dev, appl->proto.group_address);
+	if (err < 0)
+		goto err3;
+
+	app->dev = dev;
+	app->app = appl;
+	app->gid = RB_ROOT;
+	spin_lock_init(&app->lock);
+	skb_queue_head_init(&app->queue);
+	rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
+	timer_setup(&app->join_timer, garp_join_timer, 0);
+	garp_join_timer_arm(app);
+	return 0;
+
+err3:
+	kfree(app);
+err2:
+	garp_release_port(dev);
+err1:
+	return err;
+}
+EXPORT_SYMBOL_GPL(garp_init_applicant);
+
+void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+
+	ASSERT_RTNL();
+
+	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
+
+	/* Delete timer and generate a final TRANSMIT_PDU event to flush out
+	 * all pending messages before the applicant is gone. */
+	timer_shutdown_sync(&app->join_timer);
+
+	spin_lock_bh(&app->lock);
+	garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+	garp_attr_destroy_all(app);
+	garp_pdu_queue(app);
+	spin_unlock_bh(&app->lock);
+
+	garp_queue_xmit(app);
+
+	dev_mc_del(dev, appl->proto.group_address);
+	kfree_rcu(app, rcu);
+	garp_release_port(dev);
+}
+EXPORT_SYMBOL_GPL(garp_uninit_applicant);
+
+int garp_register_application(struct garp_application *appl)
+{
+	appl->proto.rcv = garp_pdu_rcv;
+	appl->proto.data = appl;
+	return stp_proto_register(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_register_application);
+
+void garp_unregister_application(struct garp_application *appl)
+{
+	stp_proto_unregister(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_unregister_application);
diff --git a/net/802/mrp.c b/net/802/mrp.c
new file mode 100644
index 000000000..160a3b145
--- /dev/null
+++ b/net/802/mrp.c
@@ -0,0 +1,953 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	IEEE 802.1Q Multiple Registration Protocol (MRP)
+ *
+ *	Copyright (c) 2012 Massachusetts Institute of Technology
+ *
+ *	Adapted from code in net/802/garp.c
+ *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <net/mrp.h>
+#include <linux/unaligned.h>
+
+static unsigned int mrp_join_time __read_mostly = 200;
+module_param(mrp_join_time, uint, 0644);
+MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
+
+static unsigned int mrp_periodic_time __read_mostly = 1000;
+module_param(mrp_periodic_time, uint, 0644);
+MODULE_PARM_DESC(mrp_periodic_time, "Periodic time in ms (default 1s)");
+
+MODULE_DESCRIPTION("IEEE 802.1Q Multiple Registration Protocol (MRP)");
+MODULE_LICENSE("GPL");
+
+static const u8
+mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
+	[MRP_APPLICANT_VO] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VO,
+	},
+	[MRP_APPLICANT_VP] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_VO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VP,
+	},
+	[MRP_APPLICANT_VN] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_VN,
+	},
+	[MRP_APPLICANT_AN] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_AN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AN,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VN,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AN,
+	},
+	[MRP_APPLICANT_AA] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
+	},
+	[MRP_APPLICANT_QA] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QA,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AA,
+	},
+	[MRP_APPLICANT_LA] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AA,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_LA,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_LA,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_LA,
+	},
+	[MRP_APPLICANT_AO] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AO,
+	},
+	[MRP_APPLICANT_QO] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QO,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QO,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QO,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QO,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AO,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VO,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_QO,
+	},
+	[MRP_APPLICANT_AP] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_AO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QA,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
+	},
+	[MRP_APPLICANT_QP] = {
+		[MRP_EVENT_NEW]		= MRP_APPLICANT_VN,
+		[MRP_EVENT_JOIN]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_LV]		= MRP_APPLICANT_QO,
+		[MRP_EVENT_TX]		= MRP_APPLICANT_QP,
+		[MRP_EVENT_R_NEW]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_R_JOIN_IN]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_R_IN]	= MRP_APPLICANT_QP,
+		[MRP_EVENT_R_JOIN_MT]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_MT]	= MRP_APPLICANT_AP,
+		[MRP_EVENT_R_LV]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_R_LA]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_REDECLARE]	= MRP_APPLICANT_VP,
+		[MRP_EVENT_PERIODIC]	= MRP_APPLICANT_AP,
+	},
+};
+
+static const u8
+mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
+	[MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+	[MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
+	[MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
+	[MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
+	[MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
+	[MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
+	[MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
+	[MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+	[MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+	[MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
+	[MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
+};
+
+static void mrp_attrvalue_inc(void *value, u8 len)
+{
+	u8 *v = (u8 *)value;
+
+	/* Add 1 to the last byte. If it becomes zero,
+	 * go to the previous byte and repeat.
+	 */
+	while (len > 0 && !++v[--len])
+		;
+}
+
+static int mrp_attr_cmp(const struct mrp_attr *attr,
+			 const void *value, u8 len, u8 type)
+{
+	if (attr->type != type)
+		return attr->type - type;
+	if (attr->len != len)
+		return attr->len - len;
+	return memcmp(attr->value, value, len);
+}
+
+static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
+					const void *value, u8 len, u8 type)
+{
+	struct rb_node *parent = app->mad.rb_node;
+	struct mrp_attr *attr;
+	int d;
+
+	while (parent) {
+		attr = rb_entry(parent, struct mrp_attr, node);
+		d = mrp_attr_cmp(attr, value, len, type);
+		if (d > 0)
+			parent = parent->rb_left;
+		else if (d < 0)
+			parent = parent->rb_right;
+		else
+			return attr;
+	}
+	return NULL;
+}
+
+static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
+					const void *value, u8 len, u8 type)
+{
+	struct rb_node *parent = NULL, **p = &app->mad.rb_node;
+	struct mrp_attr *attr;
+	int d;
+
+	while (*p) {
+		parent = *p;
+		attr = rb_entry(parent, struct mrp_attr, node);
+		d = mrp_attr_cmp(attr, value, len, type);
+		if (d > 0)
+			p = &parent->rb_left;
+		else if (d < 0)
+			p = &parent->rb_right;
+		else {
+			/* The attribute already exists; re-use it. */
+			return attr;
+		}
+	}
+	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	if (!attr)
+		return attr;
+	attr->state = MRP_APPLICANT_VO;
+	attr->type  = type;
+	attr->len   = len;
+	memcpy(attr->value, value, len);
+
+	rb_link_node(&attr->node, parent, p);
+	rb_insert_color(&attr->node, &app->mad);
+	return attr;
+}
+
+static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
+{
+	rb_erase(&attr->node, &app->mad);
+	kfree(attr);
+}
+
+static void mrp_attr_destroy_all(struct mrp_applicant *app)
+{
+	struct rb_node *node, *next;
+	struct mrp_attr *attr;
+
+	for (node = rb_first(&app->mad);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct mrp_attr, node);
+		mrp_attr_destroy(app, attr);
+	}
+}
+
+static int mrp_pdu_init(struct mrp_applicant *app)
+{
+	struct sk_buff *skb;
+	struct mrp_pdu_hdr *ph;
+
+	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
+			GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	skb->dev = app->dev;
+	skb->protocol = app->app->pkttype.type;
+	skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	ph = __skb_put(skb, sizeof(*ph));
+	ph->version = app->app->version;
+
+	app->pdu = skb;
+	return 0;
+}
+
+static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
+{
+	__be16 *endmark;
+
+	if (skb_tailroom(app->pdu) < sizeof(*endmark))
+		return -1;
+	endmark = __skb_put(app->pdu, sizeof(*endmark));
+	put_unaligned(MRP_END_MARK, endmark);
+	return 0;
+}
+
+static void mrp_pdu_queue(struct mrp_applicant *app)
+{
+	if (!app->pdu)
+		return;
+
+	if (mrp_cb(app->pdu)->mh)
+		mrp_pdu_append_end_mark(app);
+	mrp_pdu_append_end_mark(app);
+
+	dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
+			app->app->group_address, app->dev->dev_addr,
+			app->pdu->len);
+
+	skb_queue_tail(&app->queue, app->pdu);
+	app->pdu = NULL;
+}
+
+static void mrp_queue_xmit(struct mrp_applicant *app)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&app->queue)))
+		dev_queue_xmit(skb);
+}
+
+static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
+				  u8 attrtype, u8 attrlen)
+{
+	struct mrp_msg_hdr *mh;
+
+	if (mrp_cb(app->pdu)->mh) {
+		if (mrp_pdu_append_end_mark(app) < 0)
+			return -1;
+		mrp_cb(app->pdu)->mh = NULL;
+		mrp_cb(app->pdu)->vah = NULL;
+	}
+
+	if (skb_tailroom(app->pdu) < sizeof(*mh))
+		return -1;
+	mh = __skb_put(app->pdu, sizeof(*mh));
+	mh->attrtype = attrtype;
+	mh->attrlen = attrlen;
+	mrp_cb(app->pdu)->mh = mh;
+	return 0;
+}
+
+static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
+				      const void *firstattrvalue, u8 attrlen)
+{
+	struct mrp_vecattr_hdr *vah;
+
+	if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
+		return -1;
+	vah = __skb_put(app->pdu, sizeof(*vah) + attrlen);
+	put_unaligned(0, &vah->lenflags);
+	memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
+	mrp_cb(app->pdu)->vah = vah;
+	memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
+	return 0;
+}
+
+static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
+					const struct mrp_attr *attr,
+					enum mrp_vecattr_event vaevent)
+{
+	u16 len, pos;
+	u8 *vaevents;
+	int err;
+again:
+	if (!app->pdu) {
+		err = mrp_pdu_init(app);
+		if (err < 0)
+			return err;
+	}
+
+	/* If there is no Message header in the PDU, or the Message header is
+	 * for a different attribute type, add an EndMark (if necessary) and a
+	 * new Message header to the PDU.
+	 */
+	if (!mrp_cb(app->pdu)->mh ||
+	    mrp_cb(app->pdu)->mh->attrtype != attr->type ||
+	    mrp_cb(app->pdu)->mh->attrlen != attr->len) {
+		if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
+			goto queue;
+	}
+
+	/* If there is no VectorAttribute header for this Message in the PDU,
+	 * or this attribute's value does not sequentially follow the previous
+	 * attribute's value, add a new VectorAttribute header to the PDU.
+	 */
+	if (!mrp_cb(app->pdu)->vah ||
+	    memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
+		if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
+			goto queue;
+	}
+
+	len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
+	pos = len % 3;
+
+	/* Events are packed into Vectors in the PDU, three to a byte. Add a
+	 * byte to the end of the Vector if necessary.
+	 */
+	if (!pos) {
+		if (skb_tailroom(app->pdu) < sizeof(u8))
+			goto queue;
+		vaevents = __skb_put(app->pdu, sizeof(u8));
+	} else {
+		vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
+	}
+
+	switch (pos) {
+	case 0:
+		*vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
+				       __MRP_VECATTR_EVENT_MAX);
+		break;
+	case 1:
+		*vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
+		break;
+	case 2:
+		*vaevents += vaevent;
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	/* Increment the length of the VectorAttribute in the PDU, as well as
+	 * the value of the next attribute that would continue its Vector.
+	 */
+	put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
+	mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
+
+	return 0;
+
+queue:
+	mrp_pdu_queue(app);
+	goto again;
+}
+
+static void mrp_attr_event(struct mrp_applicant *app,
+			   struct mrp_attr *attr, enum mrp_event event)
+{
+	enum mrp_applicant_state state;
+
+	state = mrp_applicant_state_table[attr->state][event];
+	if (state == MRP_APPLICANT_INVALID) {
+		WARN_ON(1);
+		return;
+	}
+
+	if (event == MRP_EVENT_TX) {
+		/* When appending the attribute fails, don't update its state
+		 * in order to retry at the next TX event.
+		 */
+
+		switch (mrp_tx_action_table[attr->state]) {
+		case MRP_TX_ACTION_NONE:
+		case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
+		case MRP_TX_ACTION_S_IN_OPTIONAL:
+			break;
+		case MRP_TX_ACTION_S_NEW:
+			if (mrp_pdu_append_vecattr_event(
+				    app, attr, MRP_VECATTR_EVENT_NEW) < 0)
+				return;
+			break;
+		case MRP_TX_ACTION_S_JOIN_IN:
+			if (mrp_pdu_append_vecattr_event(
+				    app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
+				return;
+			break;
+		case MRP_TX_ACTION_S_LV:
+			if (mrp_pdu_append_vecattr_event(
+				    app, attr, MRP_VECATTR_EVENT_LV) < 0)
+				return;
+			/* As a pure applicant, sending a leave message
+			 * implies that the attribute was unregistered and
+			 * can be destroyed.
+			 */
+			mrp_attr_destroy(app, attr);
+			return;
+		default:
+			WARN_ON(1);
+		}
+	}
+
+	attr->state = state;
+}
+
+int mrp_request_join(const struct net_device *dev,
+		     const struct mrp_application *appl,
+		     const void *value, u8 len, u8 type)
+{
+	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+	struct mrp_applicant *app = rtnl_dereference(
+		port->applicants[appl->type]);
+	struct mrp_attr *attr;
+
+	if (sizeof(struct mrp_skb_cb) + len >
+	    sizeof_field(struct sk_buff, cb))
+		return -ENOMEM;
+
+	spin_lock_bh(&app->lock);
+	attr = mrp_attr_create(app, value, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return -ENOMEM;
+	}
+	mrp_attr_event(app, attr, MRP_EVENT_JOIN);
+	spin_unlock_bh(&app->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mrp_request_join);
+
+void mrp_request_leave(const struct net_device *dev,
+		       const struct mrp_application *appl,
+		       const void *value, u8 len, u8 type)
+{
+	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+	struct mrp_applicant *app = rtnl_dereference(
+		port->applicants[appl->type]);
+	struct mrp_attr *attr;
+
+	if (sizeof(struct mrp_skb_cb) + len >
+	    sizeof_field(struct sk_buff, cb))
+		return;
+
+	spin_lock_bh(&app->lock);
+	attr = mrp_attr_lookup(app, value, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return;
+	}
+	mrp_attr_event(app, attr, MRP_EVENT_LV);
+	spin_unlock_bh(&app->lock);
+}
+EXPORT_SYMBOL_GPL(mrp_request_leave);
+
+static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
+{
+	struct rb_node *node, *next;
+	struct mrp_attr *attr;
+
+	for (node = rb_first(&app->mad);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct mrp_attr, node);
+		mrp_attr_event(app, attr, event);
+	}
+}
+
+static void mrp_join_timer_arm(struct mrp_applicant *app)
+{
+	unsigned long delay;
+
+	delay = get_random_u32_below(msecs_to_jiffies(mrp_join_time));
+	mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void mrp_join_timer(struct timer_list *t)
+{
+	struct mrp_applicant *app = timer_container_of(app, t, join_timer);
+
+	spin_lock(&app->lock);
+	mrp_mad_event(app, MRP_EVENT_TX);
+	mrp_pdu_queue(app);
+	spin_unlock(&app->lock);
+
+	mrp_queue_xmit(app);
+	spin_lock(&app->lock);
+	if (likely(app->active))
+		mrp_join_timer_arm(app);
+	spin_unlock(&app->lock);
+}
+
+static void mrp_periodic_timer_arm(struct mrp_applicant *app)
+{
+	mod_timer(&app->periodic_timer,
+		  jiffies + msecs_to_jiffies(mrp_periodic_time));
+}
+
+static void mrp_periodic_timer(struct timer_list *t)
+{
+	struct mrp_applicant *app = timer_container_of(app, t, periodic_timer);
+
+	spin_lock(&app->lock);
+	if (likely(app->active)) {
+		mrp_mad_event(app, MRP_EVENT_PERIODIC);
+		mrp_pdu_queue(app);
+		mrp_periodic_timer_arm(app);
+	}
+	spin_unlock(&app->lock);
+}
+
+static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
+{
+	__be16 endmark;
+
+	if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
+		return -1;
+	if (endmark == MRP_END_MARK) {
+		*offset += sizeof(endmark);
+		return -1;
+	}
+	return 0;
+}
+
+static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
+					struct sk_buff *skb,
+					enum mrp_vecattr_event vaevent)
+{
+	struct mrp_attr *attr;
+	enum mrp_event event;
+
+	attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
+			       mrp_cb(skb)->mh->attrlen,
+			       mrp_cb(skb)->mh->attrtype);
+	if (attr == NULL)
+		return;
+
+	switch (vaevent) {
+	case MRP_VECATTR_EVENT_NEW:
+		event = MRP_EVENT_R_NEW;
+		break;
+	case MRP_VECATTR_EVENT_JOIN_IN:
+		event = MRP_EVENT_R_JOIN_IN;
+		break;
+	case MRP_VECATTR_EVENT_IN:
+		event = MRP_EVENT_R_IN;
+		break;
+	case MRP_VECATTR_EVENT_JOIN_MT:
+		event = MRP_EVENT_R_JOIN_MT;
+		break;
+	case MRP_VECATTR_EVENT_MT:
+		event = MRP_EVENT_R_MT;
+		break;
+	case MRP_VECATTR_EVENT_LV:
+		event = MRP_EVENT_R_LV;
+		break;
+	default:
+		return;
+	}
+
+	mrp_attr_event(app, attr, event);
+}
+
+static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
+				 struct sk_buff *skb, int *offset)
+{
+	struct mrp_vecattr_hdr _vah;
+	u16 valen;
+	u8 vaevents, vaevent;
+
+	mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
+					      &_vah);
+	if (!mrp_cb(skb)->vah)
+		return -1;
+	*offset += sizeof(_vah);
+
+	if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
+	    MRP_VECATTR_HDR_FLAG_LA)
+		mrp_mad_event(app, MRP_EVENT_R_LA);
+	valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
+			    MRP_VECATTR_HDR_LEN_MASK);
+
+	/* If valen is 0, only a LeaveAllEvent is present; FirstValue and
+	 * Vector fields are absent per IEEE 802.1ak.
+	 */
+	if (valen == 0)
+		return 0;
+
+	/* The VectorAttribute structure in a PDU carries event information
+	 * about one or more attributes having consecutive values. Only the
+	 * value for the first attribute is contained in the structure. So
+	 * we make a copy of that value, and then increment it each time we
+	 * advance to the next event in its Vector.
+	 */
+	if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
+	    sizeof_field(struct sk_buff, cb))
+		return -1;
+	if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
+			  mrp_cb(skb)->mh->attrlen) < 0)
+		return -1;
+	*offset += mrp_cb(skb)->mh->attrlen;
+
+	/* In a VectorAttribute, the Vector contains events which are packed
+	 * three to a byte. We process one byte of the Vector at a time.
+	 */
+	while (valen > 0) {
+		if (skb_copy_bits(skb, *offset, &vaevents,
+				  sizeof(vaevents)) < 0)
+			return -1;
+		*offset += sizeof(vaevents);
+
+		/* Extract and process the first event. */
+		vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
+				      __MRP_VECATTR_EVENT_MAX);
+		if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
+			/* The byte is malformed; stop processing. */
+			return -1;
+		}
+		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+
+		/* If present, extract and process the second event. */
+		if (!--valen)
+			break;
+		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
+				  mrp_cb(skb)->mh->attrlen);
+		vaevents %= (__MRP_VECATTR_EVENT_MAX *
+			     __MRP_VECATTR_EVENT_MAX);
+		vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
+		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+
+		/* If present, extract and process the third event. */
+		if (!--valen)
+			break;
+		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
+				  mrp_cb(skb)->mh->attrlen);
+		vaevents %= __MRP_VECATTR_EVENT_MAX;
+		vaevent = vaevents;
+		mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+		valen--;
+		mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
+				  mrp_cb(skb)->mh->attrlen);
+	}
+	return 0;
+}
+
+static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
+			     int *offset)
+{
+	struct mrp_msg_hdr _mh;
+
+	mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
+	if (!mrp_cb(skb)->mh)
+		return -1;
+	*offset += sizeof(_mh);
+
+	if (mrp_cb(skb)->mh->attrtype == 0 ||
+	    mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
+	    mrp_cb(skb)->mh->attrlen == 0)
+		return -1;
+
+	while (skb->len > *offset) {
+		if (mrp_pdu_parse_end_mark(skb, offset) < 0)
+			break;
+		if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
+			return -1;
+	}
+	return 0;
+}
+
+static int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
+		   struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct mrp_application *appl = container_of(pt, struct mrp_application,
+						    pkttype);
+	struct mrp_port *port;
+	struct mrp_applicant *app;
+	struct mrp_pdu_hdr _ph;
+	const struct mrp_pdu_hdr *ph;
+	int offset = skb_network_offset(skb);
+
+	/* If the interface is in promiscuous mode, drop the packet if
+	 * it was unicast to another host.
+	 */
+	if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
+		goto out;
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (unlikely(!skb))
+		goto out;
+	port = rcu_dereference(dev->mrp_port);
+	if (unlikely(!port))
+		goto out;
+	app = rcu_dereference(port->applicants[appl->type]);
+	if (unlikely(!app))
+		goto out;
+
+	ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
+	if (!ph)
+		goto out;
+	offset += sizeof(_ph);
+
+	if (ph->version != app->app->version)
+		goto out;
+
+	spin_lock(&app->lock);
+	while (skb->len > offset) {
+		if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
+			break;
+		if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
+			break;
+	}
+	spin_unlock(&app->lock);
+out:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int mrp_init_port(struct net_device *dev)
+{
+	struct mrp_port *port;
+
+	port = kzalloc_obj(*port);
+	if (!port)
+		return -ENOMEM;
+	rcu_assign_pointer(dev->mrp_port, port);
+	return 0;
+}
+
+static void mrp_release_port(struct net_device *dev)
+{
+	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+	unsigned int i;
+
+	for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
+		if (rtnl_dereference(port->applicants[i]))
+			return;
+	}
+	RCU_INIT_POINTER(dev->mrp_port, NULL);
+	kfree_rcu(port, rcu);
+}
+
+int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
+{
+	struct mrp_applicant *app;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (!rtnl_dereference(dev->mrp_port)) {
+		err = mrp_init_port(dev);
+		if (err < 0)
+			goto err1;
+	}
+
+	err = -ENOMEM;
+	app = kzalloc_obj(*app);
+	if (!app)
+		goto err2;
+
+	err = dev_mc_add(dev, appl->group_address);
+	if (err < 0)
+		goto err3;
+
+	app->dev = dev;
+	app->app = appl;
+	app->mad = RB_ROOT;
+	app->active = true;
+	spin_lock_init(&app->lock);
+	skb_queue_head_init(&app->queue);
+	rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
+	timer_setup(&app->join_timer, mrp_join_timer, 0);
+	mrp_join_timer_arm(app);
+	timer_setup(&app->periodic_timer, mrp_periodic_timer, 0);
+	mrp_periodic_timer_arm(app);
+	return 0;
+
+err3:
+	kfree(app);
+err2:
+	mrp_release_port(dev);
+err1:
+	return err;
+}
+EXPORT_SYMBOL_GPL(mrp_init_applicant);
+
+void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
+{
+	struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+	struct mrp_applicant *app = rtnl_dereference(
+		port->applicants[appl->type]);
+
+	ASSERT_RTNL();
+
+	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
+
+	spin_lock_bh(&app->lock);
+	app->active = false;
+	spin_unlock_bh(&app->lock);
+	/* Delete timer and generate a final TX event to flush out
+	 * all pending messages before the applicant is gone.
+	 */
+	timer_shutdown_sync(&app->join_timer);
+	timer_shutdown_sync(&app->periodic_timer);
+
+	spin_lock_bh(&app->lock);
+	mrp_mad_event(app, MRP_EVENT_TX);
+	mrp_attr_destroy_all(app);
+	mrp_pdu_queue(app);
+	spin_unlock_bh(&app->lock);
+
+	mrp_queue_xmit(app);
+
+	dev_mc_del(dev, appl->group_address);
+	kfree_rcu(app, rcu);
+	mrp_release_port(dev);
+}
+EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
+
+int mrp_register_application(struct mrp_application *appl)
+{
+	appl->pkttype.func = mrp_rcv;
+	dev_add_pack(&appl->pkttype);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mrp_register_application);
+
+void mrp_unregister_application(struct mrp_application *appl)
+{
+	dev_remove_pack(&appl->pkttype);
+}
+EXPORT_SYMBOL_GPL(mrp_unregister_application);
diff --git a/net/802/psnap.c b/net/802/psnap.c
new file mode 100644
index 000000000..8ae835e1c
--- /dev/null
+++ b/net/802/psnap.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	SNAP data link layer. Derived from 802.2
+ *
+ *		Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ *		from the 802.2 layer by Greg Page.
+ *		Merged in additions from Greg Page's psnap.c.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/datalink.h>
+#include <net/llc.h>
+#include <net/psnap.h>
+#include <linux/mm.h>
+#include <linux/in.h>
+#include <linux/init.h>
+#include <linux/rculist.h>
+
+static LIST_HEAD(snap_list);
+static DEFINE_SPINLOCK(snap_lock);
+static struct llc_sap *snap_sap;
+
+/*
+ *	Find a snap client by matching the 5 bytes.
+ */
+static struct datalink_proto *find_snap_client(const unsigned char *desc)
+{
+	struct datalink_proto *proto = NULL, *p;
+
+	list_for_each_entry_rcu(p, &snap_list, node, lockdep_is_held(&snap_lock)) {
+		if (!memcmp(p->type, desc, 5)) {
+			proto = p;
+			break;
+		}
+	}
+	return proto;
+}
+
+/*
+ *	A SNAP packet has arrived
+ */
+static int snap_rcv(struct sk_buff *skb, struct net_device *dev,
+		    struct packet_type *pt, struct net_device *orig_dev)
+{
+	int rc = 1;
+	struct datalink_proto *proto;
+	static struct packet_type snap_packet_type = {
+		.type = cpu_to_be16(ETH_P_SNAP),
+	};
+
+	if (unlikely(!pskb_may_pull(skb, 5)))
+		goto drop;
+
+	rcu_read_lock();
+	proto = find_snap_client(skb->data);
+	if (proto) {
+		/* Pass the frame on. */
+		skb_pull_rcsum(skb, 5);
+		skb_reset_transport_header(skb);
+		rc = proto->rcvfunc(skb, dev, &snap_packet_type, orig_dev);
+	}
+	rcu_read_unlock();
+
+	if (unlikely(!proto))
+		goto drop;
+
+out:
+	return rc;
+
+drop:
+	kfree_skb(skb);
+	goto out;
+}
+
+/*
+ *	Put a SNAP header on a frame and pass to 802.2
+ */
+static int snap_request(struct datalink_proto *dl,
+			struct sk_buff *skb, const u8 *dest)
+{
+	memcpy(skb_push(skb, 5), dl->type, 5);
+	llc_build_and_send_ui_pkt(snap_sap, skb, dest, snap_sap->laddr.lsap);
+	return 0;
+}
+
+/*
+ *	Set up the SNAP layer
+ */
+EXPORT_SYMBOL(register_snap_client);
+EXPORT_SYMBOL(unregister_snap_client);
+
+static const char snap_err_msg[] __initconst =
+	KERN_CRIT "SNAP - unable to register with 802.2\n";
+
+static int __init snap_init(void)
+{
+	snap_sap = llc_sap_open(0xAA, snap_rcv);
+	if (!snap_sap) {
+		printk(snap_err_msg);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+module_init(snap_init);
+
+static void __exit snap_exit(void)
+{
+	llc_sap_put(snap_sap);
+}
+
+module_exit(snap_exit);
+
+
+/*
+ *	Register SNAP clients. We don't yet use this for IP.
+ */
+struct datalink_proto *register_snap_client(const unsigned char *desc,
+					    int (*rcvfunc)(struct sk_buff *,
+							   struct net_device *,
+							   struct packet_type *,
+							   struct net_device *))
+{
+	struct datalink_proto *proto = NULL;
+
+	spin_lock_bh(&snap_lock);
+
+	if (find_snap_client(desc))
+		goto out;
+
+	proto = kmalloc_obj(*proto, GFP_ATOMIC);
+	if (proto) {
+		memcpy(proto->type, desc, 5);
+		proto->rcvfunc		= rcvfunc;
+		proto->header_length	= 5 + 3; /* snap + 802.2 */
+		proto->request		= snap_request;
+		list_add_rcu(&proto->node, &snap_list);
+	}
+out:
+	spin_unlock_bh(&snap_lock);
+
+	return proto;
+}
+
+/*
+ *	Unregister SNAP clients. Protocols no longer want to play with us ...
+ */
+void unregister_snap_client(struct datalink_proto *proto)
+{
+	spin_lock_bh(&snap_lock);
+	list_del_rcu(&proto->node);
+	spin_unlock_bh(&snap_lock);
+
+	synchronize_net();
+
+	kfree(proto);
+}
+
+MODULE_DESCRIPTION("SNAP data link layer. Derived from 802.2");
+MODULE_LICENSE("GPL");
diff --git a/net/802/stp.c b/net/802/stp.c
new file mode 100644
index 000000000..03c9f75e9
--- /dev/null
+++ b/net/802/stp.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	STP SAP demux
+ *
+ *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/mutex.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/llc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <net/llc.h>
+#include <net/llc_pdu.h>
+#include <net/stp.h>
+
+/* 01:80:c2:00:00:20 - 01:80:c2:00:00:2F */
+#define GARP_ADDR_MIN	0x20
+#define GARP_ADDR_MAX	0x2F
+#define GARP_ADDR_RANGE	(GARP_ADDR_MAX - GARP_ADDR_MIN)
+
+static const struct stp_proto __rcu *garp_protos[GARP_ADDR_RANGE + 1] __read_mostly;
+static const struct stp_proto __rcu *stp_proto __read_mostly;
+
+static struct llc_sap *sap __read_mostly;
+static unsigned int sap_registered;
+static DEFINE_MUTEX(stp_proto_mutex);
+
+/* Called under rcu_read_lock from LLC */
+static int stp_pdu_rcv(struct sk_buff *skb, struct net_device *dev,
+		       struct packet_type *pt, struct net_device *orig_dev)
+{
+	const struct ethhdr *eh = eth_hdr(skb);
+	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+	const struct stp_proto *proto;
+
+	if (pdu->ssap != LLC_SAP_BSPAN ||
+	    pdu->dsap != LLC_SAP_BSPAN ||
+	    pdu->ctrl_1 != LLC_PDU_TYPE_U)
+		goto err;
+
+	if (eh->h_dest[5] >= GARP_ADDR_MIN && eh->h_dest[5] <= GARP_ADDR_MAX) {
+		proto = rcu_dereference(garp_protos[eh->h_dest[5] -
+						    GARP_ADDR_MIN]);
+		if (proto &&
+		    !ether_addr_equal(eh->h_dest, proto->group_address))
+			goto err;
+	} else
+		proto = rcu_dereference(stp_proto);
+
+	if (!proto)
+		goto err;
+
+	proto->rcv(proto, skb, dev);
+	return 0;
+
+err:
+	kfree_skb(skb);
+	return 0;
+}
+
+int stp_proto_register(const struct stp_proto *proto)
+{
+	int err = 0;
+
+	mutex_lock(&stp_proto_mutex);
+	if (sap_registered++ == 0) {
+		sap = llc_sap_open(LLC_SAP_BSPAN, stp_pdu_rcv);
+		if (!sap) {
+			err = -ENOMEM;
+			goto out;
+		}
+	}
+	if (is_zero_ether_addr(proto->group_address))
+		rcu_assign_pointer(stp_proto, proto);
+	else
+		rcu_assign_pointer(garp_protos[proto->group_address[5] -
+					       GARP_ADDR_MIN], proto);
+out:
+	mutex_unlock(&stp_proto_mutex);
+	return err;
+}
+EXPORT_SYMBOL_GPL(stp_proto_register);
+
+void stp_proto_unregister(const struct stp_proto *proto)
+{
+	mutex_lock(&stp_proto_mutex);
+	if (is_zero_ether_addr(proto->group_address))
+		RCU_INIT_POINTER(stp_proto, NULL);
+	else
+		RCU_INIT_POINTER(garp_protos[proto->group_address[5] -
+					       GARP_ADDR_MIN], NULL);
+	synchronize_rcu();
+
+	if (--sap_registered == 0)
+		llc_sap_put(sap);
+	mutex_unlock(&stp_proto_mutex);
+}
+EXPORT_SYMBOL_GPL(stp_proto_unregister);
+
+MODULE_DESCRIPTION("SAP demux for IEEE 802.1D Spanning Tree Protocol (STP)");
+MODULE_LICENSE("GPL");