Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1372 insertions, 0 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
new file mode 100644
index 000000000..cdcd27318
--- /dev/null
+++ b/net/tipc/bearer.c
@@ -0,0 +1,1372 @@
+/*
+ * net/tipc/bearer.c: TIPC bearer code
+ *
+ * Copyright (c) 1996-2006, 2013-2016, Ericsson AB
+ * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <net/sock.h>
+#include "core.h"
+#include "bearer.h"
+#include "link.h"
+#include "discover.h"
+#include "monitor.h"
+#include "bcast.h"
+#include "netlink.h"
+#include "udp_media.h"
+#include "trace.h"
+#include "crypto.h"
+
+#define MAX_ADDR_STR 60
+
+static struct tipc_media * const media_info_array[] = {
+	&eth_media_info,
+#ifdef CONFIG_TIPC_MEDIA_IB
+	&ib_media_info,
+#endif
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	&udp_media_info,
+#endif
+	NULL
+};
+
+static struct tipc_bearer *bearer_get(struct net *net, int bearer_id)
+{
+	struct tipc_net *tn = tipc_net(net);
+
+	return rcu_dereference(tn->bearer_list[bearer_id]);
+}
+
+static void bearer_disable(struct net *net, struct tipc_bearer *b);
+static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
+			   struct packet_type *pt, struct net_device *orig_dev);
+
+/**
+ * tipc_media_find - locates specified media object by name
+ * @name: name to locate
+ */
+struct tipc_media *tipc_media_find(const char *name)
+{
+	u32 i;
+
+	for (i = 0; media_info_array[i] != NULL; i++) {
+		if (!strcmp(media_info_array[i]->name, name))
+			break;
+	}
+	return media_info_array[i];
+}
+
+/**
+ * media_find_id - locates specified media object by type identifier
+ * @type: type identifier to locate
+ */
+static struct tipc_media *media_find_id(u8 type)
+{
+	u32 i;
+
+	for (i = 0; media_info_array[i] != NULL; i++) {
+		if (media_info_array[i]->type_id == type)
+			break;
+	}
+	return media_info_array[i];
+}
+
+/**
+ * tipc_media_addr_printf - record media address in print buffer
+ * @buf: output buffer
+ * @len: output buffer size remaining
+ * @a: input media address
+ */
+int tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
+{
+	char addr_str[MAX_ADDR_STR];
+	struct tipc_media *m;
+	int ret;
+
+	m = media_find_id(a->media_id);
+
+	if (m && !m->addr2str(a, addr_str, sizeof(addr_str)))
+		ret = scnprintf(buf, len, "%s(%s)", m->name, addr_str);
+	else {
+		u32 i;
+
+		ret = scnprintf(buf, len, "UNKNOWN(%u)", a->media_id);
+		for (i = 0; i < sizeof(a->value); i++)
+			ret += scnprintf(buf + ret, len - ret,
+					    "-%x", a->value[i]);
+	}
+	return ret;
+}
+
+/**
+ * bearer_name_validate - validate & (optionally) deconstruct bearer name
+ * @name: ptr to bearer name string
+ * @name_parts: ptr to area for bearer name components (or NULL if not needed)
+ *
+ * Return: 1 if bearer name is valid, otherwise 0.
+ */
+static int bearer_name_validate(const char *name,
+				struct tipc_bearer_names *name_parts)
+{
+	char name_copy[TIPC_MAX_BEARER_NAME];
+	char *media_name;
+	char *if_name;
+	u32 media_len;
+	u32 if_len;
+
+	/* copy bearer name & ensure length is OK */
+	if (strscpy(name_copy, name, TIPC_MAX_BEARER_NAME) < 0)
+		return 0;
+
+	/* ensure all component parts of bearer name are present */
+	media_name = name_copy;
+	if_name = strchr(media_name, ':');
+	if (if_name == NULL)
+		return 0;
+	*(if_name++) = 0;
+	media_len = if_name - media_name;
+	if_len = strlen(if_name) + 1;
+
+	/* validate component parts of bearer name */
+	if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
+	    (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
+		return 0;
+
+	/* return bearer name components, if necessary */
+	if (name_parts) {
+		strcpy(name_parts->media_name, media_name);
+		strcpy(name_parts->if_name, if_name);
+	}
+	return 1;
+}
+
+/**
+ * tipc_bearer_find - locates bearer object with matching bearer name
+ * @net: the applicable net namespace
+ * @name: bearer name to locate
+ */
+struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bearer *b;
+	u32 i;
+
+	for (i = 0; i < MAX_BEARERS; i++) {
+		b = rtnl_dereference(tn->bearer_list[i]);
+		if (b && (!strcmp(b->name, name)))
+			return b;
+	}
+	return NULL;
+}
+
+/*     tipc_bearer_get_name - get the bearer name from its id.
+ *     @net: network namespace
+ *     @name: a pointer to the buffer where the name will be stored.
+ *     @bearer_id: the id to get the name from.
+ */
+int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_bearer *b;
+
+	if (bearer_id >= MAX_BEARERS)
+		return -EINVAL;
+
+	b = rtnl_dereference(tn->bearer_list[bearer_id]);
+	if (!b)
+		return -EINVAL;
+
+	strcpy(name, b->name);
+	return 0;
+}
+
+void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference(tn->bearer_list[bearer_id]);
+	if (b)
+		tipc_disc_add_dest(b->disc);
+	rcu_read_unlock();
+}
+
+void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference(tn->bearer_list[bearer_id]);
+	if (b)
+		tipc_disc_remove_dest(b->disc);
+	rcu_read_unlock();
+}
+
+/**
+ * tipc_enable_bearer - enable bearer with the given name
+ * @net: the applicable net namespace
+ * @name: bearer name to enable
+ * @disc_domain: bearer domain
+ * @prio: bearer priority
+ * @attr: nlattr array
+ * @extack: netlink extended ack
+ */
+static int tipc_enable_bearer(struct net *net, const char *name,
+			      u32 disc_domain, u32 prio,
+			      struct nlattr *attr[],
+			      struct netlink_ext_ack *extack)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_bearer_names b_names;
+	int with_this_prio = 1;
+	struct tipc_bearer *b;
+	struct tipc_media *m;
+	struct sk_buff *skb;
+	int bearer_id = 0;
+	int res = -EINVAL;
+	char *errstr = "";
+	u32 i;
+
+	if (!bearer_name_validate(name, &b_names)) {
+		NL_SET_ERR_MSG(extack, "Illegal name");
+		return res;
+	}
+
+	if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
+		errstr = "illegal priority";
+		NL_SET_ERR_MSG(extack, "Illegal priority");
+		goto rejected;
+	}
+
+	m = tipc_media_find(b_names.media_name);
+	if (!m) {
+		errstr = "media not registered";
+		NL_SET_ERR_MSG(extack, "Media not registered");
+		goto rejected;
+	}
+
+	if (prio == TIPC_MEDIA_LINK_PRI)
+		prio = m->priority;
+
+	/* Check new bearer vs existing ones and find free bearer id if any */
+	bearer_id = MAX_BEARERS;
+	i = MAX_BEARERS;
+	while (i-- != 0) {
+		b = rtnl_dereference(tn->bearer_list[i]);
+		if (!b) {
+			bearer_id = i;
+			continue;
+		}
+		if (!strcmp(name, b->name)) {
+			errstr = "already enabled";
+			NL_SET_ERR_MSG(extack, "Already enabled");
+			goto rejected;
+		}
+
+		if (b->priority == prio &&
+		    (++with_this_prio > 2)) {
+			pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
+				name, prio);
+
+			if (prio == TIPC_MIN_LINK_PRI) {
+				errstr = "cannot adjust to lower";
+				NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
+				goto rejected;
+			}
+
+			pr_warn("Bearer <%s>: trying with adjusted priority\n",
+				name);
+			prio--;
+			bearer_id = MAX_BEARERS;
+			i = MAX_BEARERS;
+			with_this_prio = 1;
+		}
+	}
+
+	if (bearer_id >= MAX_BEARERS) {
+		errstr = "max 3 bearers permitted";
+		NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
+		goto rejected;
+	}
+
+	b = kzalloc(sizeof(*b), GFP_ATOMIC);
+	if (!b)
+		return -ENOMEM;
+
+	strcpy(b->name, name);
+	b->media = m;
+	res = m->enable_media(net, b, attr);
+	if (res) {
+		kfree(b);
+		errstr = "failed to enable media";
+		NL_SET_ERR_MSG(extack, "Failed to enable media");
+		goto rejected;
+	}
+
+	b->identity = bearer_id;
+	b->tolerance = m->tolerance;
+	b->min_win = m->min_win;
+	b->max_win = m->max_win;
+	b->domain = disc_domain;
+	b->net_plane = bearer_id + 'A';
+	b->priority = prio;
+	refcount_set(&b->refcnt, 1);
+
+	res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
+	if (res) {
+		bearer_disable(net, b);
+		errstr = "failed to create discoverer";
+		NL_SET_ERR_MSG(extack, "Failed to create discoverer");
+		goto rejected;
+	}
+
+	/* Create monitoring data before accepting activate messages */
+	if (tipc_mon_create(net, bearer_id)) {
+		bearer_disable(net, b);
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	test_and_set_bit_lock(0, &b->up);
+	rcu_assign_pointer(tn->bearer_list[bearer_id], b);
+	if (skb)
+		tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);
+
+	pr_info("Enabled bearer <%s>, priority %u\n", name, prio);
+
+	return res;
+rejected:
+	pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
+	return res;
+}
+
+/**
+ * tipc_reset_bearer - Reset all links established over this bearer
+ * @net: the applicable net namespace
+ * @b: the target bearer
+ */
+static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
+{
+	pr_info("Resetting bearer <%s>\n", b->name);
+	tipc_node_delete_links(net, b->identity);
+	tipc_disc_reset(net, b);
+	return 0;
+}
+
+bool tipc_bearer_hold(struct tipc_bearer *b)
+{
+	return (b && refcount_inc_not_zero(&b->refcnt));
+}
+
+void tipc_bearer_put(struct tipc_bearer *b)
+{
+	if (b && refcount_dec_and_test(&b->refcnt))
+		kfree_rcu(b, rcu);
+}
+
+/**
+ * bearer_disable - disable this bearer
+ * @net: the applicable net namespace
+ * @b: the bearer to disable
+ *
+ * Note: This routine assumes caller holds RTNL lock.
+ */
+static void bearer_disable(struct net *net, struct tipc_bearer *b)
+{
+	struct tipc_net *tn = tipc_net(net);
+	int bearer_id = b->identity;
+
+	pr_info("Disabling bearer <%s>\n", b->name);
+	clear_bit_unlock(0, &b->up);
+	tipc_node_delete_links(net, bearer_id);
+	b->media->disable_media(b);
+	RCU_INIT_POINTER(b->media_ptr, NULL);
+	if (b->disc)
+		tipc_disc_delete(b->disc);
+	RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
+	tipc_bearer_put(b);
+	tipc_mon_delete(net, bearer_id);
+}
+
+int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
+			 struct nlattr *attr[])
+{
+	char *dev_name = strchr((const char *)b->name, ':') + 1;
+	int hwaddr_len = b->media->hwaddr_len;
+	u8 node_id[NODE_ID_LEN] = {0,};
+	struct net_device *dev;
+
+	/* Find device with specified name */
+	dev = dev_get_by_name(net, dev_name);
+	if (!dev)
+		return -ENODEV;
+	if (tipc_mtu_bad(dev, 0)) {
+		dev_put(dev);
+		return -EINVAL;
+	}
+	if (dev == net->loopback_dev) {
+		dev_put(dev);
+		pr_info("Enabling <%s> not permitted\n", b->name);
+		return -EINVAL;
+	}
+
+	/* Autoconfigure own node identity if needed */
+	if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
+		memcpy(node_id, dev->dev_addr, hwaddr_len);
+		tipc_net_init(net, node_id, 0);
+	}
+	if (!tipc_own_id(net)) {
+		dev_put(dev);
+		pr_warn("Failed to obtain node identity\n");
+		return -EINVAL;
+	}
+
+	/* Associate TIPC bearer with L2 bearer */
+	rcu_assign_pointer(b->media_ptr, dev);
+	b->pt.dev = dev;
+	b->pt.type = htons(ETH_P_TIPC);
+	b->pt.func = tipc_l2_rcv_msg;
+	dev_add_pack(&b->pt);
+	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
+	memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
+	b->bcast_addr.media_id = b->media->type_id;
+	b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
+	b->mtu = dev->mtu;
+	b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
+	rcu_assign_pointer(dev->tipc_ptr, b);
+	return 0;
+}
+
+/* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
+ * @b: the target bearer
+ *
+ * Mark L2 bearer as inactive so that incoming buffers are thrown away
+ */
+void tipc_disable_l2_media(struct tipc_bearer *b)
+{
+	struct net_device *dev;
+
+	dev = (struct net_device *)rtnl_dereference(b->media_ptr);
+	dev_remove_pack(&b->pt);
+	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
+	synchronize_net();
+	dev_put(dev);
+}
+
+/**
+ * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
+ * @net: the associated network namespace
+ * @skb: the packet to be sent
+ * @b: the bearer through which the packet is to be sent
+ * @dest: peer destination address
+ */
+int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
+		     struct tipc_bearer *b, struct tipc_media_addr *dest)
+{
+	struct net_device *dev;
+	int delta;
+
+	dev = (struct net_device *)rcu_dereference(b->media_ptr);
+	if (!dev)
+		return 0;
+
+	delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
+	if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
+		kfree_skb(skb);
+		return 0;
+	}
+	skb_reset_network_header(skb);
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_TIPC);
+	dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
+			dev->dev_addr, skb->len);
+	dev_queue_xmit(skb);
+	return 0;
+}
+
+bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
+{
+	bool supp = false;
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = bearer_get(net, bearer_id);
+	if (b)
+		supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
+	rcu_read_unlock();
+	return supp;
+}
+
+int tipc_bearer_mtu(struct net *net, u32 bearer_id)
+{
+	int mtu = 0;
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference(tipc_net(net)->bearer_list[bearer_id]);
+	if (b)
+		mtu = b->mtu;
+	rcu_read_unlock();
+	return mtu;
+}
+
+int tipc_bearer_min_mtu(struct net *net, u32 bearer_id)
+{
+	int mtu = TIPC_MIN_BEARER_MTU;
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = bearer_get(net, bearer_id);
+	if (b)
+		mtu += b->encap_hlen;
+	rcu_read_unlock();
+	return mtu;
+}
+
+/* tipc_bearer_xmit_skb - sends buffer to destination over bearer
+ */
+void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
+			  struct sk_buff *skb,
+			  struct tipc_media_addr *dest)
+{
+	struct tipc_msg *hdr = buf_msg(skb);
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = bearer_get(net, bearer_id);
+	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
+#ifdef CONFIG_TIPC_CRYPTO
+		tipc_crypto_xmit(net, &skb, b, dest, NULL);
+		if (skb)
+#endif
+			b->media->send_msg(net, skb, b, dest);
+	} else {
+		kfree_skb(skb);
+	}
+	rcu_read_unlock();
+}
+
+/* tipc_bearer_xmit() -send buffer to destination over bearer
+ */
+void tipc_bearer_xmit(struct net *net, u32 bearer_id,
+		      struct sk_buff_head *xmitq,
+		      struct tipc_media_addr *dst,
+		      struct tipc_node *__dnode)
+{
+	struct tipc_bearer *b;
+	struct sk_buff *skb, *tmp;
+
+	if (skb_queue_empty(xmitq))
+		return;
+
+	rcu_read_lock();
+	b = bearer_get(net, bearer_id);
+	if (unlikely(!b))
+		__skb_queue_purge(xmitq);
+	skb_queue_walk_safe(xmitq, skb, tmp) {
+		__skb_dequeue(xmitq);
+		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
+#ifdef CONFIG_TIPC_CRYPTO
+			tipc_crypto_xmit(net, &skb, b, dst, __dnode);
+			if (skb)
+#endif
+				b->media->send_msg(net, skb, b, dst);
+		} else {
+			kfree_skb(skb);
+		}
+	}
+	rcu_read_unlock();
+}
+
+/* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
+ */
+void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
+			 struct sk_buff_head *xmitq)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_media_addr *dst;
+	int net_id = tn->net_id;
+	struct tipc_bearer *b;
+	struct sk_buff *skb, *tmp;
+	struct tipc_msg *hdr;
+
+	rcu_read_lock();
+	b = bearer_get(net, bearer_id);
+	if (unlikely(!b || !test_bit(0, &b->up)))
+		__skb_queue_purge(xmitq);
+	skb_queue_walk_safe(xmitq, skb, tmp) {
+		hdr = buf_msg(skb);
+		msg_set_non_seq(hdr, 1);
+		msg_set_mc_netid(hdr, net_id);
+		__skb_dequeue(xmitq);
+		dst = &b->bcast_addr;
+#ifdef CONFIG_TIPC_CRYPTO
+		tipc_crypto_xmit(net, &skb, b, dst, NULL);
+		if (skb)
+#endif
+			b->media->send_msg(net, skb, b, dst);
+	}
+	rcu_read_unlock();
+}
+
+/**
+ * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
+ * @skb: the received message
+ * @dev: the net device that the packet was received on
+ * @pt: the packet_type structure which was used to register this handler
+ * @orig_dev: the original receive net device in case the device is a bond
+ *
+ * Accept only packets explicitly sent to this node, or broadcast packets;
+ * ignores packets sent using interface multicast, and traffic sent to other
+ * nodes (which can happen if interface is running in promiscuous mode).
+ */
+static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
+			   struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct tipc_bearer *b;
+
+	rcu_read_lock();
+	b = rcu_dereference(dev->tipc_ptr) ?:
+		rcu_dereference(orig_dev->tipc_ptr);
+	if (likely(b && test_bit(0, &b->up) &&
+		   (skb->pkt_type <= PACKET_MULTICAST))) {
+		skb_mark_not_on_list(skb);
+		TIPC_SKB_CB(skb)->flags = 0;
+		tipc_rcv(dev_net(b->pt.dev), skb, b);
+		rcu_read_unlock();
+		return NET_RX_SUCCESS;
+	}
+	rcu_read_unlock();
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+/**
+ * tipc_l2_device_event - handle device events from network device
+ * @nb: the context of the notification
+ * @evt: the type of event
+ * @ptr: the net device that the event was on
+ *
+ * This function is called by the Ethernet driver in case of link
+ * change event.
+ */
+static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
+				void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct net *net = dev_net(dev);
+	struct tipc_bearer *b;
+
+	b = rtnl_dereference(dev->tipc_ptr);
+	if (!b)
+		return NOTIFY_DONE;
+
+	trace_tipc_l2_device_event(dev, b, evt);
+	switch (evt) {
+	case NETDEV_CHANGE:
+		if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
+			test_and_set_bit_lock(0, &b->up);
+			break;
+		}
+		fallthrough;
+	case NETDEV_GOING_DOWN:
+		clear_bit_unlock(0, &b->up);
+		tipc_reset_bearer(net, b);
+		break;
+	case NETDEV_UP:
+		test_and_set_bit_lock(0, &b->up);
+		break;
+	case NETDEV_CHANGEMTU:
+		if (tipc_mtu_bad(dev, 0)) {
+			bearer_disable(net, b);
+			break;
+		}
+		b->mtu = dev->mtu;
+		tipc_reset_bearer(net, b);
+		break;
+	case NETDEV_CHANGEADDR:
+		b->media->raw2addr(b, &b->addr,
+				   (const char *)dev->dev_addr);
+		tipc_reset_bearer(net, b);
+		break;
+	case NETDEV_UNREGISTER:
+	case NETDEV_CHANGENAME:
+		bearer_disable(net, b);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block notifier = {
+	.notifier_call  = tipc_l2_device_event,
+	.priority	= 0,
+};
+
+int tipc_bearer_setup(void)
+{
+	return register_netdevice_notifier(&notifier);
+}
+
+void tipc_bearer_cleanup(void)
+{
+	unregister_netdevice_notifier(&notifier);
+}
+
+void tipc_bearer_stop(struct net *net)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_bearer *b;
+	u32 i;
+
+	for (i = 0; i < MAX_BEARERS; i++) {
+		b = rtnl_dereference(tn->bearer_list[i]);
+		if (b) {
+			bearer_disable(net, b);
+			tn->bearer_list[i] = NULL;
+		}
+	}
+}
+
+void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
+{
+	struct net_device *dev = net->loopback_dev;
+	struct sk_buff *skb, *_skb;
+	int exp;
+
+	skb_queue_walk(pkts, _skb) {
+		skb = pskb_copy(_skb, GFP_ATOMIC);
+		if (!skb)
+			continue;
+
+		exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
+		if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
+			kfree_skb(skb);
+			continue;
+		}
+
+		skb_reset_network_header(skb);
+		dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
+				dev->dev_addr, skb->len);
+		skb->dev = dev;
+		skb->pkt_type = PACKET_HOST;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		skb->protocol = eth_type_trans(skb, dev);
+		netif_rx(skb);
+	}
+}
+
+static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
+				 struct packet_type *pt, struct net_device *od)
+{
+	consume_skb(skb);
+	return NET_RX_SUCCESS;
+}
+
+int tipc_attach_loopback(struct net *net)
+{
+	struct net_device *dev = net->loopback_dev;
+	struct tipc_net *tn = tipc_net(net);
+
+	if (!dev)
+		return -ENODEV;
+
+	netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
+	tn->loopback_pt.dev = dev;
+	tn->loopback_pt.type = htons(ETH_P_TIPC);
+	tn->loopback_pt.func = tipc_loopback_rcv_pkt;
+	dev_add_pack(&tn->loopback_pt);
+	return 0;
+}
+
+void tipc_detach_loopback(struct net *net)
+{
+	struct tipc_net *tn = tipc_net(net);
+
+	dev_remove_pack(&tn->loopback_pt);
+	netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
+}
+
+/* Caller should hold rtnl_lock to protect the bearer */
+static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
+				struct tipc_bearer *bearer, int nlflags)
+{
+	void *hdr;
+	struct nlattr *attrs;
+	struct nlattr *prop;
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+			  nlflags, TIPC_NL_BEARER_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
+	if (!attrs)
+		goto msg_full;
+
+	if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
+		goto attr_msg_full;
+
+	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
+	if (!prop)
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
+		goto prop_msg_full;
+	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
+		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
+			goto prop_msg_full;
+
+	nla_nest_end(msg->skb, prop);
+
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
+		if (tipc_udp_nl_add_bearer_data(msg, bearer))
+			goto attr_msg_full;
+	}
+#endif
+
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+prop_msg_full:
+	nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	int i = cb->args[0];
+	struct tipc_bearer *bearer;
+	struct tipc_nl_msg msg;
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+
+	if (i == MAX_BEARERS)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rtnl_lock();
+	for (i = 0; i < MAX_BEARERS; i++) {
+		bearer = rtnl_dereference(tn->bearer_list[i]);
+		if (!bearer)
+			continue;
+
+		err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
+		if (err)
+			break;
+	}
+	rtnl_unlock();
+
+	cb->args[0] = i;
+	return skb->len;
+}
+
+int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct sk_buff *rep;
+	struct tipc_bearer *bearer;
+	struct tipc_nl_msg msg;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = genl_info_net(info);
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
+					  info->attrs[TIPC_NLA_BEARER],
+					  tipc_nl_bearer_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!rep)
+		return -ENOMEM;
+
+	msg.skb = rep;
+	msg.portid = info->snd_portid;
+	msg.seq = info->snd_seq;
+
+	rtnl_lock();
+	bearer = tipc_bearer_find(net, name);
+	if (!bearer) {
+		err = -EINVAL;
+		NL_SET_ERR_MSG(info->extack, "Bearer not found");
+		goto err_out;
+	}
+
+	err = __tipc_nl_add_bearer(&msg, bearer, 0);
+	if (err)
+		goto err_out;
+	rtnl_unlock();
+
+	return genlmsg_reply(rep, info);
+err_out:
+	rtnl_unlock();
+	nlmsg_free(rep);
+
+	return err;
+}
+
+int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct tipc_bearer *bearer;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
+					  info->attrs[TIPC_NLA_BEARER],
+					  tipc_nl_bearer_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+
+	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	bearer = tipc_bearer_find(net, name);
+	if (!bearer) {
+		NL_SET_ERR_MSG(info->extack, "Bearer not found");
+		return -EINVAL;
+	}
+
+	bearer_disable(net, bearer);
+
+	return 0;
+}
+
+int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_bearer_disable(skb, info);
+	rtnl_unlock();
+
+	return err;
+}
+
+int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *bearer;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	u32 domain = 0;
+	u32 prio;
+
+	prio = TIPC_MEDIA_LINK_PRI;
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
+					  info->attrs[TIPC_NLA_BEARER],
+					  tipc_nl_bearer_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+
+	bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	if (attrs[TIPC_NLA_BEARER_DOMAIN])
+		domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);
+
+	if (attrs[TIPC_NLA_BEARER_PROP]) {
+		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
+					      props);
+		if (err)
+			return err;
+
+		if (props[TIPC_NLA_PROP_PRIO])
+			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+	}
+
+	return tipc_enable_bearer(net, bearer, domain, prio, attrs,
+				  info->extack);
+}
+
+int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_bearer_enable(skb, info);
+	rtnl_unlock();
+
+	return err;
+}
+
+int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct tipc_bearer *b;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
+					  info->attrs[TIPC_NLA_BEARER],
+					  tipc_nl_bearer_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	rtnl_lock();
+	b = tipc_bearer_find(net, name);
+	if (!b) {
+		rtnl_unlock();
+		NL_SET_ERR_MSG(info->extack, "Bearer not found");
+		return -EINVAL;
+	}
+
+#ifdef CONFIG_TIPC_MEDIA_UDP
+	if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
+		err = tipc_udp_nl_bearer_add(b,
+					     attrs[TIPC_NLA_BEARER_UDP_OPTS]);
+		if (err) {
+			rtnl_unlock();
+			return err;
+		}
+	}
+#endif
+	rtnl_unlock();
+
+	return 0;
+}
+
+int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
+{
+	struct tipc_bearer *b;
+	struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	char *name;
+	int err;
+
+	if (!info->attrs[TIPC_NLA_BEARER])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
+					  info->attrs[TIPC_NLA_BEARER],
+					  tipc_nl_bearer_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_BEARER_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);
+
+	b = tipc_bearer_find(net, name);
+	if (!b) {
+		NL_SET_ERR_MSG(info->extack, "Bearer not found");
+		return -EINVAL;
+	}
+
+	if (attrs[TIPC_NLA_BEARER_PROP]) {
+		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
+					      props);
+		if (err)
+			return err;
+
+		if (props[TIPC_NLA_PROP_TOL]) {
+			b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+			tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
+		}
+		if (props[TIPC_NLA_PROP_PRIO])
+			b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+		if (props[TIPC_NLA_PROP_WIN])
+			b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+		if (props[TIPC_NLA_PROP_MTU]) {
+			if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
+				NL_SET_ERR_MSG(info->extack,
+					       "MTU property is unsupported");
+				return -EINVAL;
+			}
+#ifdef CONFIG_TIPC_MEDIA_UDP
+			if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) <
+			    b->encap_hlen + TIPC_MIN_BEARER_MTU) {
+				NL_SET_ERR_MSG(info->extack,
+					       "MTU value is out-of-range");
+				return -EINVAL;
+			}
+			b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
+			tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
+#endif
+		}
+	}
+
+	return 0;
+}
+
+int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_bearer_set(skb, info);
+	rtnl_unlock();
+
+	return err;
+}
+
+static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
+			       struct tipc_media *media, int nlflags)
+{
+	void *hdr;
+	struct nlattr *attrs;
+	struct nlattr *prop;
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+			  nlflags, TIPC_NL_MEDIA_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
+	if (!attrs)
+		goto msg_full;
+
+	if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
+		goto attr_msg_full;
+
+	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
+	if (!prop)
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
+		goto prop_msg_full;
+	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
+		goto prop_msg_full;
+	if (media->type_id == TIPC_MEDIA_TYPE_UDP)
+		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
+			goto prop_msg_full;
+
+	nla_nest_end(msg->skb, prop);
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+prop_msg_full:
+	nla_nest_cancel(msg->skb, prop);
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	int i = cb->args[0];
+	struct tipc_nl_msg msg;
+
+	if (i == MAX_MEDIA)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rtnl_lock();
+	for (; media_info_array[i] != NULL; i++) {
+		err = __tipc_nl_add_media(&msg, media_info_array[i],
+					  NLM_F_MULTI);
+		if (err)
+			break;
+	}
+	rtnl_unlock();
+
+	cb->args[0] = i;
+	return skb->len;
+}
+
+int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct tipc_nl_msg msg;
+	struct tipc_media *media;
+	struct sk_buff *rep;
+	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
+
+	if (!info->attrs[TIPC_NLA_MEDIA])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
+					  info->attrs[TIPC_NLA_MEDIA],
+					  tipc_nl_media_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_MEDIA_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
+
+	rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!rep)
+		return -ENOMEM;
+
+	msg.skb = rep;
+	msg.portid = info->snd_portid;
+	msg.seq = info->snd_seq;
+
+	rtnl_lock();
+	media = tipc_media_find(name);
+	if (!media) {
+		NL_SET_ERR_MSG(info->extack, "Media not found");
+		err = -EINVAL;
+		goto err_out;
+	}
+
+	err = __tipc_nl_add_media(&msg, media, 0);
+	if (err)
+		goto err_out;
+	rtnl_unlock();
+
+	return genlmsg_reply(rep, info);
+err_out:
+	rtnl_unlock();
+	nlmsg_free(rep);
+
+	return err;
+}
+
+int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *name;
+	struct tipc_media *m;
+	struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];
+
+	if (!info->attrs[TIPC_NLA_MEDIA])
+		return -EINVAL;
+
+	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
+					  info->attrs[TIPC_NLA_MEDIA],
+					  tipc_nl_media_policy, info->extack);
+
+	if (!attrs[TIPC_NLA_MEDIA_NAME])
+		return -EINVAL;
+	name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);
+
+	m = tipc_media_find(name);
+	if (!m) {
+		NL_SET_ERR_MSG(info->extack, "Media not found");
+		return -EINVAL;
+	}
+	if (attrs[TIPC_NLA_MEDIA_PROP]) {
+		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
+					      props);
+		if (err)
+			return err;
+
+		if (props[TIPC_NLA_PROP_TOL])
+			m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+		if (props[TIPC_NLA_PROP_PRIO])
+			m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+		if (props[TIPC_NLA_PROP_WIN])
+			m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+		if (props[TIPC_NLA_PROP_MTU]) {
+			if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
+				NL_SET_ERR_MSG(info->extack,
+					       "MTU property is unsupported");
+				return -EINVAL;
+			}
+#ifdef CONFIG_TIPC_MEDIA_UDP
+			if (tipc_udp_mtu_bad(nla_get_u32
+					     (props[TIPC_NLA_PROP_MTU]))) {
+				NL_SET_ERR_MSG(info->extack,
+					       "MTU value is out-of-range");
+				return -EINVAL;
+			}
+			m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
+#endif
+		}
+	}
+
+	return 0;
+}
+
+int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+
+	rtnl_lock();
+	err = __tipc_nl_media_set(skb, info);
+	rtnl_unlock();
+
+	return err;
+}