Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

11 files changed, 2482 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..19406a87b
--- /dev/null
+++ b/net/802/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux 802.x protocol layers.
+#
+
+# Check the p8022 selections against net/core/Makefile.
+obj-$(CONFIG_LLC)	+= p8022.o psnap.o
+obj-$(CONFIG_NET_FC)	+=                 fc.o
+obj-$(CONFIG_FDDI)	+=                 fddi.o
+obj-$(CONFIG_HIPPI)	+=                 hippi.o
+obj-$(CONFIG_IPX)	+= p8022.o psnap.o p8023.o
+obj-$(CONFIG_ATALK)	+= p8022.o psnap.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..7533ce26b
--- /dev/null
+++ b/net/802/fddi.c
@@ -0,0 +1,178 @@
+// 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(fddi->hdr.llc_8022_1.dsap==0xe0)
+	{
+		skb_pull(skb, FDDI_K_8022_HLEN-3);
+		type = htons(ETH_P_802_2);
+	}
+	else
+	{
+		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_LICENSE("GPL");
diff --git a/net/802/garp.c b/net/802/garp.c
new file mode 100644
index 000000000..f6012f8e5
--- /dev/null
+++ b/net/802/garp.c
@@ -0,0 +1,649 @@
+// 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 <asm/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_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 = (u64)msecs_to_jiffies(garp_join_time) * prandom_u32() >> 32;
+	mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void garp_join_timer(struct timer_list *t)
+{
+	struct garp_applicant *app = from_timer(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;
+	skb_pull(skb, ga->len);
+	dlen = sizeof(*ga) - ga->len;
+
+	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;
+
+	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));
+
+	while (skb->len > 0) {
+		if (garp_pdu_parse_attr(app, skb, gm->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(sizeof(*port), GFP_KERNEL);
+	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(sizeof(*app), GFP_KERNEL);
+	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. */
+	del_timer_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/hippi.c b/net/802/hippi.c
new file mode 100644
index 000000000..f80b33a8f
--- /dev/null
+++ b/net/802/hippi.c
@@ -0,0 +1,193 @@
+// 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.
+ *
+ *		HIPPI-type device handling.
+ *
+ * Version:	@(#)hippi.c	1.0.0	05/29/97
+ *
+ * Authors:	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>
+ *		Jes Sorensen, <Jes.Sorensen@cern.ch>
+ */
+
+#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/hippidevice.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <net/arp.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+
+/*
+ * Create the HIPPI 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 hippi_header(struct sk_buff *skb, struct net_device *dev,
+			unsigned short type,
+			const void *daddr, const void *saddr, unsigned int len)
+{
+	struct hippi_hdr *hip = skb_push(skb, HIPPI_HLEN);
+	struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
+
+	if (!len){
+		len = skb->len - HIPPI_HLEN;
+		printk("hippi_header(): length not supplied\n");
+	}
+
+	/*
+	 * Due to the stupidity of the little endian byte-order we
+	 * have to set the fp field this way.
+	 */
+	hip->fp.fixed		= htonl(0x04800018);
+	hip->fp.d2_size		= htonl(len + 8);
+	hip->le.fc		= 0;
+	hip->le.double_wide	= 0;	/* only HIPPI 800 for the time being */
+	hip->le.message_type	= 0;	/* Data PDU */
+
+	hip->le.dest_addr_type	= 2;	/* 12 bit SC address */
+	hip->le.src_addr_type	= 2;	/* 12 bit SC address */
+
+	memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
+	memset(&hip->le.reserved, 0, 16);
+
+	hip->snap.dsap		= HIPPI_EXTENDED_SAP;
+	hip->snap.ssap		= HIPPI_EXTENDED_SAP;
+	hip->snap.ctrl		= HIPPI_UI_CMD;
+	hip->snap.oui[0]	= 0x00;
+	hip->snap.oui[1]	= 0x00;
+	hip->snap.oui[2]	= 0x00;
+	hip->snap.ethertype	= htons(type);
+
+	if (daddr)
+	{
+		memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
+		memcpy(&hcb->ifield, daddr + 2, 4);
+		return HIPPI_HLEN;
+	}
+	hcb->ifield = 0;
+	return -((int)HIPPI_HLEN);
+}
+
+
+/*
+ *	Determine the packet's protocol ID.
+ */
+
+__be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
+{
+	struct hippi_hdr *hip;
+
+	/*
+	 * This is actually wrong ... question is if we really should
+	 * set the raw address here.
+	 */
+	skb->dev = dev;
+	skb_reset_mac_header(skb);
+	hip = (struct hippi_hdr *)skb_mac_header(skb);
+	skb_pull(skb, HIPPI_HLEN);
+
+	/*
+	 * No fancy promisc stuff here now.
+	 */
+
+	return hip->snap.ethertype;
+}
+
+EXPORT_SYMBOL(hippi_type_trans);
+
+/*
+ * For HIPPI we will actually use the lower 4 bytes of the hardware
+ * address as the I-FIELD rather than the actual hardware address.
+ */
+int hippi_mac_addr(struct net_device *dev, void *p)
+{
+	struct sockaddr *addr = p;
+	if (netif_running(dev))
+		return -EBUSY;
+	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
+	return 0;
+}
+EXPORT_SYMBOL(hippi_mac_addr);
+
+int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
+{
+	/* Never send broadcast/multicast ARP messages */
+	NEIGH_VAR_INIT(p, MCAST_PROBES, 0);
+
+	/* In IPv6 unicast probes are valid even on NBMA,
+	* because they are encapsulated in normal IPv6 protocol.
+	* Should be a generic flag.
+	*/
+	if (p->tbl->family != AF_INET6)
+		NEIGH_VAR_INIT(p, UCAST_PROBES, 0);
+	return 0;
+}
+EXPORT_SYMBOL(hippi_neigh_setup_dev);
+
+static const struct header_ops hippi_header_ops = {
+	.create		= hippi_header,
+};
+
+
+static void hippi_setup(struct net_device *dev)
+{
+	dev->header_ops			= &hippi_header_ops;
+
+	/*
+	 * We don't support HIPPI `ARP' for the time being, and probably
+	 * never will unless someone else implements it. However we
+	 * still need a fake ARPHRD to make ifconfig and friends play ball.
+	 */
+	dev->type		= ARPHRD_HIPPI;
+	dev->hard_header_len 	= HIPPI_HLEN;
+	dev->mtu		= 65280;
+	dev->min_mtu		= 68;
+	dev->max_mtu		= 65280;
+	dev->addr_len		= HIPPI_ALEN;
+	dev->tx_queue_len	= 25 /* 5 */;
+	memset(dev->broadcast, 0xFF, HIPPI_ALEN);
+
+
+	/*
+	 * HIPPI doesn't support broadcast+multicast and we only use
+	 * static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
+	 */
+	dev->flags = 0;
+}
+
+/**
+ * alloc_hippi_dev - Register HIPPI device
+ * @sizeof_priv: Size of additional driver-private structure to be allocated
+ *	for this HIPPI device
+ *
+ * Fill in the fields of the device structure with HIPPI-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_hippi_dev(int sizeof_priv)
+{
+	return alloc_netdev(sizeof_priv, "hip%d", NET_NAME_UNKNOWN,
+			    hippi_setup);
+}
+
+EXPORT_SYMBOL(alloc_hippi_dev);
diff --git a/net/802/mrp.c b/net/802/mrp.c
new file mode 100644
index 000000000..c10a432a5
--- /dev/null
+++ b/net/802/mrp.c
@@ -0,0 +1,943 @@
+// 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 <asm/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_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 = (u64)msecs_to_jiffies(mrp_join_time) * prandom_u32() >> 32;
+	mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void mrp_join_timer(struct timer_list *t)
+{
+	struct mrp_applicant *app = from_timer(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 = from_timer(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);
+
+	/* 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);
+	}
+	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(sizeof(*port), GFP_KERNEL);
+	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(sizeof(*app), GFP_KERNEL);
+	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.
+	 */
+	del_timer_sync(&app->join_timer);
+	del_timer_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/p8022.c b/net/802/p8022.c
new file mode 100644
index 000000000..a65856270
--- /dev/null
+++ b/net/802/p8022.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	NET3:	Support for 802.2 demultiplexing off Ethernet
+ *
+ *		Demultiplex 802.2 encoded protocols. We match the entry by the
+ *		SSAP/DSAP pair and then deliver to the registered datalink that
+ *		matches. The control byte is ignored and handling of such items
+ *		is up to the routine passed the frame.
+ *
+ *		Unlike the 802.3 datalink we have a list of 802.2 entries as
+ *		there are multiple protocols to demux. The list is currently
+ *		short (3 or 4 entries at most). The current demux assumes this.
+ */
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/datalink.h>
+#include <linux/mm.h>
+#include <linux/in.h>
+#include <linux/init.h>
+#include <net/llc.h>
+#include <net/p8022.h>
+
+static int p8022_request(struct datalink_proto *dl, struct sk_buff *skb,
+			 unsigned char *dest)
+{
+	llc_build_and_send_ui_pkt(dl->sap, skb, dest, dl->sap->laddr.lsap);
+	return 0;
+}
+
+struct datalink_proto *register_8022_client(unsigned char type,
+					    int (*func)(struct sk_buff *skb,
+							struct net_device *dev,
+							struct packet_type *pt,
+							struct net_device *orig_dev))
+{
+	struct datalink_proto *proto;
+
+	proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
+	if (proto) {
+		proto->type[0]		= type;
+		proto->header_length	= 3;
+		proto->request		= p8022_request;
+		proto->sap = llc_sap_open(type, func);
+		if (!proto->sap) {
+			kfree(proto);
+			proto = NULL;
+		}
+	}
+	return proto;
+}
+
+void unregister_8022_client(struct datalink_proto *proto)
+{
+	llc_sap_put(proto->sap);
+	kfree(proto);
+}
+
+EXPORT_SYMBOL(register_8022_client);
+EXPORT_SYMBOL(unregister_8022_client);
+
+MODULE_LICENSE("GPL");
diff --git a/net/802/p8023.c b/net/802/p8023.c
new file mode 100644
index 000000000..19cd56990
--- /dev/null
+++ b/net/802/p8023.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	NET3:	802.3 data link hooks used for IPX 802.3
+ *
+ *	802.3 isn't really a protocol data link layer. Some old IPX stuff
+ *	uses it however. Note that there is only one 802.3 protocol layer
+ *	in the system. We don't currently support different protocols
+ *	running raw 802.3 on different devices. Thankfully nobody else
+ *	has done anything like the old IPX.
+ */
+
+#include <linux/in.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+
+#include <net/datalink.h>
+#include <net/p8022.h>
+
+/*
+ *	Place an 802.3 header on a packet. The driver will do the mac
+ *	addresses, we just need to give it the buffer length.
+ */
+static int p8023_request(struct datalink_proto *dl,
+			 struct sk_buff *skb, unsigned char *dest_node)
+{
+	struct net_device *dev = skb->dev;
+
+	dev_hard_header(skb, dev, ETH_P_802_3, dest_node, NULL, skb->len);
+	return dev_queue_xmit(skb);
+}
+
+/*
+ *	Create an 802.3 client. Note there can be only one 802.3 client
+ */
+struct datalink_proto *make_8023_client(void)
+{
+	struct datalink_proto *proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
+
+	if (proto) {
+		proto->header_length = 0;
+		proto->request	     = p8023_request;
+	}
+	return proto;
+}
+
+/*
+ *	Destroy the 802.3 client.
+ */
+void destroy_8023_client(struct datalink_proto *dl)
+{
+	kfree(dl);
+}
+
+EXPORT_SYMBOL(destroy_8023_client);
+EXPORT_SYMBOL(make_8023_client);
+
+MODULE_LICENSE("GPL");
diff --git a/net/802/psnap.c b/net/802/psnap.c
new file mode 100644
index 000000000..4492e8d7a
--- /dev/null
+++ b/net/802/psnap.c
@@ -0,0 +1,163 @@
+// 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_transport_header(skb));
+	if (proto) {
+		/* Pass the frame on. */
+		skb->transport_header += 5;
+		skb_pull_rcsum(skb, 5);
+		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, 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(sizeof(*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_LICENSE("GPL");
diff --git a/net/802/stp.c b/net/802/stp.c
new file mode 100644
index 000000000..d550d9f88
--- /dev/null
+++ b/net/802/stp.c
@@ -0,0 +1,101 @@
+// 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_LICENSE("GPL");