v4.19.13 snapshot.
diff --git a/net/tipc/node.c b/net/tipc/node.c
new file mode 100644
index 0000000..4880197
--- /dev/null
+++ b/net/tipc/node.c
@@ -0,0 +1,2427 @@
+/*
+ * net/tipc/node.c: TIPC node management routines
+ *
+ * Copyright (c) 2000-2006, 2012-2016, Ericsson AB
+ * Copyright (c) 2005-2006, 2010-2014, 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 "core.h"
+#include "link.h"
+#include "node.h"
+#include "name_distr.h"
+#include "socket.h"
+#include "bcast.h"
+#include "monitor.h"
+#include "discover.h"
+#include "netlink.h"
+
+#define INVALID_NODE_SIG	0x10000
+#define NODE_CLEANUP_AFTER	300000
+
+/* Flags used to take different actions according to flag type
+ * TIPC_NOTIFY_NODE_DOWN: notify node is down
+ * TIPC_NOTIFY_NODE_UP: notify node is up
+ * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
+ */
+enum {
+	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
+	TIPC_NOTIFY_NODE_UP		= (1 << 4),
+	TIPC_NOTIFY_LINK_UP		= (1 << 6),
+	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
+};
+
+struct tipc_link_entry {
+	struct tipc_link *link;
+	spinlock_t lock; /* per link */
+	u32 mtu;
+	struct sk_buff_head inputq;
+	struct tipc_media_addr maddr;
+};
+
+struct tipc_bclink_entry {
+	struct tipc_link *link;
+	struct sk_buff_head inputq1;
+	struct sk_buff_head arrvq;
+	struct sk_buff_head inputq2;
+	struct sk_buff_head namedq;
+};
+
+/**
+ * struct tipc_node - TIPC node structure
+ * @addr: network address of node
+ * @ref: reference counter to node object
+ * @lock: rwlock governing access to structure
+ * @net: the applicable net namespace
+ * @hash: links to adjacent nodes in unsorted hash chain
+ * @inputq: pointer to input queue containing messages for msg event
+ * @namedq: pointer to name table input queue with name table messages
+ * @active_links: bearer ids of active links, used as index into links[] array
+ * @links: array containing references to all links to node
+ * @action_flags: bit mask of different types of node actions
+ * @state: connectivity state vs peer node
+ * @sync_point: sequence number where synch/failover is finished
+ * @list: links to adjacent nodes in sorted list of cluster's nodes
+ * @working_links: number of working links to node (both active and standby)
+ * @link_cnt: number of links to node
+ * @capabilities: bitmap, indicating peer node's functional capabilities
+ * @signature: node instance identifier
+ * @link_id: local and remote bearer ids of changing link, if any
+ * @publ_list: list of publications
+ * @rcu: rcu struct for tipc_node
+ * @delete_at: indicates the time for deleting a down node
+ */
+struct tipc_node {
+	u32 addr;
+	struct kref kref;
+	rwlock_t lock;
+	struct net *net;
+	struct hlist_node hash;
+	int active_links[2];
+	struct tipc_link_entry links[MAX_BEARERS];
+	struct tipc_bclink_entry bc_entry;
+	int action_flags;
+	struct list_head list;
+	int state;
+	bool failover_sent;
+	u16 sync_point;
+	int link_cnt;
+	u16 working_links;
+	u16 capabilities;
+	u32 signature;
+	u32 link_id;
+	u8 peer_id[16];
+	struct list_head publ_list;
+	struct list_head conn_sks;
+	unsigned long keepalive_intv;
+	struct timer_list timer;
+	struct rcu_head rcu;
+	unsigned long delete_at;
+};
+
+/* Node FSM states and events:
+ */
+enum {
+	SELF_DOWN_PEER_DOWN    = 0xdd,
+	SELF_UP_PEER_UP        = 0xaa,
+	SELF_DOWN_PEER_LEAVING = 0xd1,
+	SELF_UP_PEER_COMING    = 0xac,
+	SELF_COMING_PEER_UP    = 0xca,
+	SELF_LEAVING_PEER_DOWN = 0x1d,
+	NODE_FAILINGOVER       = 0xf0,
+	NODE_SYNCHING          = 0xcc
+};
+
+enum {
+	SELF_ESTABL_CONTACT_EVT = 0xece,
+	SELF_LOST_CONTACT_EVT   = 0x1ce,
+	PEER_ESTABL_CONTACT_EVT = 0x9ece,
+	PEER_LOST_CONTACT_EVT   = 0x91ce,
+	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
+	NODE_FAILOVER_END_EVT   = 0xfee,
+	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
+	NODE_SYNCH_END_EVT      = 0xcee
+};
+
+static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
+				  struct sk_buff_head *xmitq,
+				  struct tipc_media_addr **maddr);
+static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
+				bool delete);
+static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
+static void tipc_node_delete(struct tipc_node *node);
+static void tipc_node_timeout(struct timer_list *t);
+static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
+static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
+static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
+static void tipc_node_put(struct tipc_node *node);
+static bool node_is_up(struct tipc_node *n);
+static void tipc_node_delete_from_list(struct tipc_node *node);
+
+struct tipc_sock_conn {
+	u32 port;
+	u32 peer_port;
+	u32 peer_node;
+	struct list_head list;
+};
+
+static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
+{
+	int bearer_id = n->active_links[sel & 1];
+
+	if (unlikely(bearer_id == INVALID_BEARER_ID))
+		return NULL;
+
+	return n->links[bearer_id].link;
+}
+
+int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
+{
+	struct tipc_node *n;
+	int bearer_id;
+	unsigned int mtu = MAX_MSG_SIZE;
+
+	n = tipc_node_find(net, addr);
+	if (unlikely(!n))
+		return mtu;
+
+	bearer_id = n->active_links[sel & 1];
+	if (likely(bearer_id != INVALID_BEARER_ID))
+		mtu = n->links[bearer_id].mtu;
+	tipc_node_put(n);
+	return mtu;
+}
+
+bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
+{
+	u8 *own_id = tipc_own_id(net);
+	struct tipc_node *n;
+
+	if (!own_id)
+		return true;
+
+	if (addr == tipc_own_addr(net)) {
+		memcpy(id, own_id, TIPC_NODEID_LEN);
+		return true;
+	}
+	n = tipc_node_find(net, addr);
+	if (!n)
+		return false;
+
+	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
+	tipc_node_put(n);
+	return true;
+}
+
+u16 tipc_node_get_capabilities(struct net *net, u32 addr)
+{
+	struct tipc_node *n;
+	u16 caps;
+
+	n = tipc_node_find(net, addr);
+	if (unlikely(!n))
+		return TIPC_NODE_CAPABILITIES;
+	caps = n->capabilities;
+	tipc_node_put(n);
+	return caps;
+}
+
+static void tipc_node_kref_release(struct kref *kref)
+{
+	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
+
+	kfree(n->bc_entry.link);
+	kfree_rcu(n, rcu);
+}
+
+static void tipc_node_put(struct tipc_node *node)
+{
+	kref_put(&node->kref, tipc_node_kref_release);
+}
+
+static void tipc_node_get(struct tipc_node *node)
+{
+	kref_get(&node->kref);
+}
+
+/*
+ * tipc_node_find - locate specified node object, if it exists
+ */
+static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *node;
+	unsigned int thash = tipc_hashfn(addr);
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
+		if (node->addr != addr)
+			continue;
+		if (!kref_get_unless_zero(&node->kref))
+			node = NULL;
+		break;
+	}
+	rcu_read_unlock();
+	return node;
+}
+
+/* tipc_node_find_by_id - locate specified node object by its 128-bit id
+ * Note: this function is called only when a discovery request failed
+ * to find the node by its 32-bit id, and is not time critical
+ */
+static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *n;
+	bool found = false;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, &tn->node_list, list) {
+		read_lock_bh(&n->lock);
+		if (!memcmp(id, n->peer_id, 16) &&
+		    kref_get_unless_zero(&n->kref))
+			found = true;
+		read_unlock_bh(&n->lock);
+		if (found)
+			break;
+	}
+	rcu_read_unlock();
+	return found ? n : NULL;
+}
+
+static void tipc_node_read_lock(struct tipc_node *n)
+{
+	read_lock_bh(&n->lock);
+}
+
+static void tipc_node_read_unlock(struct tipc_node *n)
+{
+	read_unlock_bh(&n->lock);
+}
+
+static void tipc_node_write_lock(struct tipc_node *n)
+{
+	write_lock_bh(&n->lock);
+}
+
+static void tipc_node_write_unlock_fast(struct tipc_node *n)
+{
+	write_unlock_bh(&n->lock);
+}
+
+static void tipc_node_write_unlock(struct tipc_node *n)
+{
+	struct net *net = n->net;
+	u32 addr = 0;
+	u32 flags = n->action_flags;
+	u32 link_id = 0;
+	u32 bearer_id;
+	struct list_head *publ_list;
+
+	if (likely(!flags)) {
+		write_unlock_bh(&n->lock);
+		return;
+	}
+
+	addr = n->addr;
+	link_id = n->link_id;
+	bearer_id = link_id & 0xffff;
+	publ_list = &n->publ_list;
+
+	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
+			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
+
+	write_unlock_bh(&n->lock);
+
+	if (flags & TIPC_NOTIFY_NODE_DOWN)
+		tipc_publ_notify(net, publ_list, addr);
+
+	if (flags & TIPC_NOTIFY_NODE_UP)
+		tipc_named_node_up(net, addr);
+
+	if (flags & TIPC_NOTIFY_LINK_UP) {
+		tipc_mon_peer_up(net, addr, bearer_id);
+		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
+				     TIPC_NODE_SCOPE, link_id, link_id);
+	}
+	if (flags & TIPC_NOTIFY_LINK_DOWN) {
+		tipc_mon_peer_down(net, addr, bearer_id);
+		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
+				      addr, link_id);
+	}
+}
+
+static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
+					  u8 *peer_id, u16 capabilities)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_node *n, *temp_node;
+	struct tipc_link *l;
+	int bearer_id;
+	int i;
+
+	spin_lock_bh(&tn->node_list_lock);
+	n = tipc_node_find(net, addr);
+	if (n) {
+		if (n->capabilities == capabilities)
+			goto exit;
+		/* Same node may come back with new capabilities */
+		write_lock_bh(&n->lock);
+		n->capabilities = capabilities;
+		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
+			l = n->links[bearer_id].link;
+			if (l)
+				tipc_link_update_caps(l, capabilities);
+		}
+		write_unlock_bh(&n->lock);
+		goto exit;
+	}
+	n = kzalloc(sizeof(*n), GFP_ATOMIC);
+	if (!n) {
+		pr_warn("Node creation failed, no memory\n");
+		goto exit;
+	}
+	n->addr = addr;
+	memcpy(&n->peer_id, peer_id, 16);
+	n->net = net;
+	n->capabilities = capabilities;
+	kref_init(&n->kref);
+	rwlock_init(&n->lock);
+	INIT_HLIST_NODE(&n->hash);
+	INIT_LIST_HEAD(&n->list);
+	INIT_LIST_HEAD(&n->publ_list);
+	INIT_LIST_HEAD(&n->conn_sks);
+	skb_queue_head_init(&n->bc_entry.namedq);
+	skb_queue_head_init(&n->bc_entry.inputq1);
+	__skb_queue_head_init(&n->bc_entry.arrvq);
+	skb_queue_head_init(&n->bc_entry.inputq2);
+	for (i = 0; i < MAX_BEARERS; i++)
+		spin_lock_init(&n->links[i].lock);
+	n->state = SELF_DOWN_PEER_LEAVING;
+	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
+	n->signature = INVALID_NODE_SIG;
+	n->active_links[0] = INVALID_BEARER_ID;
+	n->active_links[1] = INVALID_BEARER_ID;
+	if (!tipc_link_bc_create(net, tipc_own_addr(net),
+				 addr, U16_MAX,
+				 tipc_link_window(tipc_bc_sndlink(net)),
+				 n->capabilities,
+				 &n->bc_entry.inputq1,
+				 &n->bc_entry.namedq,
+				 tipc_bc_sndlink(net),
+				 &n->bc_entry.link)) {
+		pr_warn("Broadcast rcv link creation failed, no memory\n");
+		kfree(n);
+		n = NULL;
+		goto exit;
+	}
+	tipc_node_get(n);
+	timer_setup(&n->timer, tipc_node_timeout, 0);
+	n->keepalive_intv = U32_MAX;
+	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
+	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
+		if (n->addr < temp_node->addr)
+			break;
+	}
+	list_add_tail_rcu(&n->list, &temp_node->list);
+exit:
+	spin_unlock_bh(&tn->node_list_lock);
+	return n;
+}
+
+static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
+{
+	unsigned long tol = tipc_link_tolerance(l);
+	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
+
+	/* Link with lowest tolerance determines timer interval */
+	if (intv < n->keepalive_intv)
+		n->keepalive_intv = intv;
+
+	/* Ensure link's abort limit corresponds to current tolerance */
+	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
+}
+
+static void tipc_node_delete_from_list(struct tipc_node *node)
+{
+	list_del_rcu(&node->list);
+	hlist_del_rcu(&node->hash);
+	tipc_node_put(node);
+}
+
+static void tipc_node_delete(struct tipc_node *node)
+{
+	tipc_node_delete_from_list(node);
+
+	del_timer_sync(&node->timer);
+	tipc_node_put(node);
+}
+
+void tipc_node_stop(struct net *net)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *node, *t_node;
+
+	spin_lock_bh(&tn->node_list_lock);
+	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
+		tipc_node_delete(node);
+	spin_unlock_bh(&tn->node_list_lock);
+}
+
+void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
+{
+	struct tipc_node *n;
+
+	if (in_own_node(net, addr))
+		return;
+
+	n = tipc_node_find(net, addr);
+	if (!n) {
+		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
+		return;
+	}
+	tipc_node_write_lock(n);
+	list_add_tail(subscr, &n->publ_list);
+	tipc_node_write_unlock_fast(n);
+	tipc_node_put(n);
+}
+
+void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
+{
+	struct tipc_node *n;
+
+	if (in_own_node(net, addr))
+		return;
+
+	n = tipc_node_find(net, addr);
+	if (!n) {
+		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
+		return;
+	}
+	tipc_node_write_lock(n);
+	list_del_init(subscr);
+	tipc_node_write_unlock_fast(n);
+	tipc_node_put(n);
+}
+
+int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
+{
+	struct tipc_node *node;
+	struct tipc_sock_conn *conn;
+	int err = 0;
+
+	if (in_own_node(net, dnode))
+		return 0;
+
+	node = tipc_node_find(net, dnode);
+	if (!node) {
+		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
+		return -EHOSTUNREACH;
+	}
+	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
+	if (!conn) {
+		err = -EHOSTUNREACH;
+		goto exit;
+	}
+	conn->peer_node = dnode;
+	conn->port = port;
+	conn->peer_port = peer_port;
+
+	tipc_node_write_lock(node);
+	list_add_tail(&conn->list, &node->conn_sks);
+	tipc_node_write_unlock(node);
+exit:
+	tipc_node_put(node);
+	return err;
+}
+
+void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
+{
+	struct tipc_node *node;
+	struct tipc_sock_conn *conn, *safe;
+
+	if (in_own_node(net, dnode))
+		return;
+
+	node = tipc_node_find(net, dnode);
+	if (!node)
+		return;
+
+	tipc_node_write_lock(node);
+	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
+		if (port != conn->port)
+			continue;
+		list_del(&conn->list);
+		kfree(conn);
+	}
+	tipc_node_write_unlock(node);
+	tipc_node_put(node);
+}
+
+static void  tipc_node_clear_links(struct tipc_node *node)
+{
+	int i;
+
+	for (i = 0; i < MAX_BEARERS; i++) {
+		struct tipc_link_entry *le = &node->links[i];
+
+		if (le->link) {
+			kfree(le->link);
+			le->link = NULL;
+			node->link_cnt--;
+		}
+	}
+}
+
+/* tipc_node_cleanup - delete nodes that does not
+ * have active links for NODE_CLEANUP_AFTER time
+ */
+static bool tipc_node_cleanup(struct tipc_node *peer)
+{
+	struct tipc_net *tn = tipc_net(peer->net);
+	bool deleted = false;
+
+	/* If lock held by tipc_node_stop() the node will be deleted anyway */
+	if (!spin_trylock_bh(&tn->node_list_lock))
+		return false;
+
+	tipc_node_write_lock(peer);
+
+	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
+		tipc_node_clear_links(peer);
+		tipc_node_delete_from_list(peer);
+		deleted = true;
+	}
+	tipc_node_write_unlock(peer);
+	spin_unlock_bh(&tn->node_list_lock);
+	return deleted;
+}
+
+/* tipc_node_timeout - handle expiration of node timer
+ */
+static void tipc_node_timeout(struct timer_list *t)
+{
+	struct tipc_node *n = from_timer(n, t, timer);
+	struct tipc_link_entry *le;
+	struct sk_buff_head xmitq;
+	int remains = n->link_cnt;
+	int bearer_id;
+	int rc = 0;
+
+	if (!node_is_up(n) && tipc_node_cleanup(n)) {
+		/*Removing the reference of Timer*/
+		tipc_node_put(n);
+		return;
+	}
+
+	__skb_queue_head_init(&xmitq);
+
+	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
+		tipc_node_read_lock(n);
+		le = &n->links[bearer_id];
+		if (le->link) {
+			spin_lock_bh(&le->lock);
+			/* Link tolerance may change asynchronously: */
+			tipc_node_calculate_timer(n, le->link);
+			rc = tipc_link_timeout(le->link, &xmitq);
+			spin_unlock_bh(&le->lock);
+			remains--;
+		}
+		tipc_node_read_unlock(n);
+		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
+		if (rc & TIPC_LINK_DOWN_EVT)
+			tipc_node_link_down(n, bearer_id, false);
+	}
+	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
+}
+
+/**
+ * __tipc_node_link_up - handle addition of link
+ * Node lock must be held by caller
+ * Link becomes active (alone or shared) or standby, depending on its priority.
+ */
+static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
+				struct sk_buff_head *xmitq)
+{
+	int *slot0 = &n->active_links[0];
+	int *slot1 = &n->active_links[1];
+	struct tipc_link *ol = node_active_link(n, 0);
+	struct tipc_link *nl = n->links[bearer_id].link;
+
+	if (!nl || tipc_link_is_up(nl))
+		return;
+
+	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
+	if (!tipc_link_is_up(nl))
+		return;
+
+	n->working_links++;
+	n->action_flags |= TIPC_NOTIFY_LINK_UP;
+	n->link_id = tipc_link_id(nl);
+
+	/* Leave room for tunnel header when returning 'mtu' to users: */
+	n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
+
+	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
+	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
+
+	pr_debug("Established link <%s> on network plane %c\n",
+		 tipc_link_name(nl), tipc_link_plane(nl));
+
+	/* Ensure that a STATE message goes first */
+	tipc_link_build_state_msg(nl, xmitq);
+
+	/* First link? => give it both slots */
+	if (!ol) {
+		*slot0 = bearer_id;
+		*slot1 = bearer_id;
+		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
+		n->failover_sent = false;
+		n->action_flags |= TIPC_NOTIFY_NODE_UP;
+		tipc_link_set_active(nl, true);
+		tipc_bcast_add_peer(n->net, nl, xmitq);
+		return;
+	}
+
+	/* Second link => redistribute slots */
+	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
+		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
+		*slot0 = bearer_id;
+		*slot1 = bearer_id;
+		tipc_link_set_active(nl, true);
+		tipc_link_set_active(ol, false);
+	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
+		tipc_link_set_active(nl, true);
+		*slot1 = bearer_id;
+	} else {
+		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
+	}
+
+	/* Prepare synchronization with first link */
+	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
+}
+
+/**
+ * tipc_node_link_up - handle addition of link
+ *
+ * Link becomes active (alone or shared) or standby, depending on its priority.
+ */
+static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
+			      struct sk_buff_head *xmitq)
+{
+	struct tipc_media_addr *maddr;
+
+	tipc_node_write_lock(n);
+	__tipc_node_link_up(n, bearer_id, xmitq);
+	maddr = &n->links[bearer_id].maddr;
+	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
+	tipc_node_write_unlock(n);
+}
+
+/**
+ * __tipc_node_link_down - handle loss of link
+ */
+static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
+				  struct sk_buff_head *xmitq,
+				  struct tipc_media_addr **maddr)
+{
+	struct tipc_link_entry *le = &n->links[*bearer_id];
+	int *slot0 = &n->active_links[0];
+	int *slot1 = &n->active_links[1];
+	int i, highest = 0, prio;
+	struct tipc_link *l, *_l, *tnl;
+
+	l = n->links[*bearer_id].link;
+	if (!l || tipc_link_is_reset(l))
+		return;
+
+	n->working_links--;
+	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
+	n->link_id = tipc_link_id(l);
+
+	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
+
+	pr_debug("Lost link <%s> on network plane %c\n",
+		 tipc_link_name(l), tipc_link_plane(l));
+
+	/* Select new active link if any available */
+	*slot0 = INVALID_BEARER_ID;
+	*slot1 = INVALID_BEARER_ID;
+	for (i = 0; i < MAX_BEARERS; i++) {
+		_l = n->links[i].link;
+		if (!_l || !tipc_link_is_up(_l))
+			continue;
+		if (_l == l)
+			continue;
+		prio = tipc_link_prio(_l);
+		if (prio < highest)
+			continue;
+		if (prio > highest) {
+			highest = prio;
+			*slot0 = i;
+			*slot1 = i;
+			continue;
+		}
+		*slot1 = i;
+	}
+
+	if (!node_is_up(n)) {
+		if (tipc_link_peer_is_down(l))
+			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
+		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
+		tipc_link_fsm_evt(l, LINK_RESET_EVT);
+		tipc_link_reset(l);
+		tipc_link_build_reset_msg(l, xmitq);
+		*maddr = &n->links[*bearer_id].maddr;
+		node_lost_contact(n, &le->inputq);
+		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
+		return;
+	}
+	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
+
+	/* There is still a working link => initiate failover */
+	*bearer_id = n->active_links[0];
+	tnl = n->links[*bearer_id].link;
+	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
+	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
+	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
+	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
+	tipc_link_reset(l);
+	tipc_link_fsm_evt(l, LINK_RESET_EVT);
+	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
+	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
+	*maddr = &n->links[*bearer_id].maddr;
+}
+
+static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
+{
+	struct tipc_link_entry *le = &n->links[bearer_id];
+	struct tipc_link *l = le->link;
+	struct tipc_media_addr *maddr;
+	struct sk_buff_head xmitq;
+	int old_bearer_id = bearer_id;
+
+	if (!l)
+		return;
+
+	__skb_queue_head_init(&xmitq);
+
+	tipc_node_write_lock(n);
+	if (!tipc_link_is_establishing(l)) {
+		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
+		if (delete) {
+			kfree(l);
+			le->link = NULL;
+			n->link_cnt--;
+		}
+	} else {
+		/* Defuse pending tipc_node_link_up() */
+		tipc_link_fsm_evt(l, LINK_RESET_EVT);
+	}
+	tipc_node_write_unlock(n);
+	if (delete)
+		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
+	tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
+	tipc_sk_rcv(n->net, &le->inputq);
+}
+
+static bool node_is_up(struct tipc_node *n)
+{
+	return n->active_links[0] != INVALID_BEARER_ID;
+}
+
+bool tipc_node_is_up(struct net *net, u32 addr)
+{
+	struct tipc_node *n;
+	bool retval = false;
+
+	if (in_own_node(net, addr))
+		return true;
+
+	n = tipc_node_find(net, addr);
+	if (!n)
+		return false;
+	retval = node_is_up(n);
+	tipc_node_put(n);
+	return retval;
+}
+
+static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
+{
+	struct tipc_node *n;
+
+	addr ^= tipc_net(net)->random;
+	while ((n = tipc_node_find(net, addr))) {
+		tipc_node_put(n);
+		addr++;
+	}
+	return addr;
+}
+
+/* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
+ * Returns suggested address if any, otherwise 0
+ */
+u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
+{
+	struct tipc_net *tn = tipc_net(net);
+	struct tipc_node *n;
+
+	/* Suggest new address if some other peer is using this one */
+	n = tipc_node_find(net, addr);
+	if (n) {
+		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
+			addr = 0;
+		tipc_node_put(n);
+		if (!addr)
+			return 0;
+		return tipc_node_suggest_addr(net, addr);
+	}
+
+	/* Suggest previously used address if peer is known */
+	n = tipc_node_find_by_id(net, id);
+	if (n) {
+		addr = n->addr;
+		tipc_node_put(n);
+		return addr;
+	}
+
+	/* Even this node may be in conflict */
+	if (tn->trial_addr == addr)
+		return tipc_node_suggest_addr(net, addr);
+
+	return 0;
+}
+
+void tipc_node_check_dest(struct net *net, u32 addr,
+			  u8 *peer_id, struct tipc_bearer *b,
+			  u16 capabilities, u32 signature,
+			  struct tipc_media_addr *maddr,
+			  bool *respond, bool *dupl_addr)
+{
+	struct tipc_node *n;
+	struct tipc_link *l;
+	struct tipc_link_entry *le;
+	bool addr_match = false;
+	bool sign_match = false;
+	bool link_up = false;
+	bool accept_addr = false;
+	bool reset = true;
+	char *if_name;
+	unsigned long intv;
+	u16 session;
+
+	*dupl_addr = false;
+	*respond = false;
+
+	n = tipc_node_create(net, addr, peer_id, capabilities);
+	if (!n)
+		return;
+
+	tipc_node_write_lock(n);
+
+	le = &n->links[b->identity];
+
+	/* Prepare to validate requesting node's signature and media address */
+	l = le->link;
+	link_up = l && tipc_link_is_up(l);
+	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
+	sign_match = (signature == n->signature);
+
+	/* These three flags give us eight permutations: */
+
+	if (sign_match && addr_match && link_up) {
+		/* All is fine. Do nothing. */
+		reset = false;
+	} else if (sign_match && addr_match && !link_up) {
+		/* Respond. The link will come up in due time */
+		*respond = true;
+	} else if (sign_match && !addr_match && link_up) {
+		/* Peer has changed i/f address without rebooting.
+		 * If so, the link will reset soon, and the next
+		 * discovery will be accepted. So we can ignore it.
+		 * It may also be an cloned or malicious peer having
+		 * chosen the same node address and signature as an
+		 * existing one.
+		 * Ignore requests until the link goes down, if ever.
+		 */
+		*dupl_addr = true;
+	} else if (sign_match && !addr_match && !link_up) {
+		/* Peer link has changed i/f address without rebooting.
+		 * It may also be a cloned or malicious peer; we can't
+		 * distinguish between the two.
+		 * The signature is correct, so we must accept.
+		 */
+		accept_addr = true;
+		*respond = true;
+	} else if (!sign_match && addr_match && link_up) {
+		/* Peer node rebooted. Two possibilities:
+		 *  - Delayed re-discovery; this link endpoint has already
+		 *    reset and re-established contact with the peer, before
+		 *    receiving a discovery message from that node.
+		 *    (The peer happened to receive one from this node first).
+		 *  - The peer came back so fast that our side has not
+		 *    discovered it yet. Probing from this side will soon
+		 *    reset the link, since there can be no working link
+		 *    endpoint at the peer end, and the link will re-establish.
+		 *  Accept the signature, since it comes from a known peer.
+		 */
+		n->signature = signature;
+	} else if (!sign_match && addr_match && !link_up) {
+		/*  The peer node has rebooted.
+		 *  Accept signature, since it is a known peer.
+		 */
+		n->signature = signature;
+		*respond = true;
+	} else if (!sign_match && !addr_match && link_up) {
+		/* Peer rebooted with new address, or a new/duplicate peer.
+		 * Ignore until the link goes down, if ever.
+		 */
+		*dupl_addr = true;
+	} else if (!sign_match && !addr_match && !link_up) {
+		/* Peer rebooted with new address, or it is a new peer.
+		 * Accept signature and address.
+		 */
+		n->signature = signature;
+		accept_addr = true;
+		*respond = true;
+	}
+
+	if (!accept_addr)
+		goto exit;
+
+	/* Now create new link if not already existing */
+	if (!l) {
+		if (n->link_cnt == 2)
+			goto exit;
+
+		if_name = strchr(b->name, ':') + 1;
+		get_random_bytes(&session, sizeof(u16));
+		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
+				      b->net_plane, b->mtu, b->priority,
+				      b->window, session,
+				      tipc_own_addr(net), addr, peer_id,
+				      n->capabilities,
+				      tipc_bc_sndlink(n->net), n->bc_entry.link,
+				      &le->inputq,
+				      &n->bc_entry.namedq, &l)) {
+			*respond = false;
+			goto exit;
+		}
+		tipc_link_reset(l);
+		tipc_link_fsm_evt(l, LINK_RESET_EVT);
+		if (n->state == NODE_FAILINGOVER)
+			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
+		le->link = l;
+		n->link_cnt++;
+		tipc_node_calculate_timer(n, l);
+		if (n->link_cnt == 1) {
+			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
+			if (!mod_timer(&n->timer, intv))
+				tipc_node_get(n);
+		}
+	}
+	memcpy(&le->maddr, maddr, sizeof(*maddr));
+exit:
+	tipc_node_write_unlock(n);
+	if (reset && l && !tipc_link_is_reset(l))
+		tipc_node_link_down(n, b->identity, false);
+	tipc_node_put(n);
+}
+
+void tipc_node_delete_links(struct net *net, int bearer_id)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_node *n;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, &tn->node_list, list) {
+		tipc_node_link_down(n, bearer_id, true);
+	}
+	rcu_read_unlock();
+}
+
+static void tipc_node_reset_links(struct tipc_node *n)
+{
+	int i;
+
+	pr_warn("Resetting all links to %x\n", n->addr);
+
+	for (i = 0; i < MAX_BEARERS; i++) {
+		tipc_node_link_down(n, i, false);
+	}
+}
+
+/* tipc_node_fsm_evt - node finite state machine
+ * Determines when contact is allowed with peer node
+ */
+static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
+{
+	int state = n->state;
+
+	switch (state) {
+	case SELF_DOWN_PEER_DOWN:
+		switch (evt) {
+		case SELF_ESTABL_CONTACT_EVT:
+			state = SELF_UP_PEER_COMING;
+			break;
+		case PEER_ESTABL_CONTACT_EVT:
+			state = SELF_COMING_PEER_UP;
+			break;
+		case SELF_LOST_CONTACT_EVT:
+		case PEER_LOST_CONTACT_EVT:
+			break;
+		case NODE_SYNCH_END_EVT:
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_FAILOVER_BEGIN_EVT:
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case SELF_UP_PEER_UP:
+		switch (evt) {
+		case SELF_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_LEAVING;
+			break;
+		case PEER_LOST_CONTACT_EVT:
+			state = SELF_LEAVING_PEER_DOWN;
+			break;
+		case NODE_SYNCH_BEGIN_EVT:
+			state = NODE_SYNCHING;
+			break;
+		case NODE_FAILOVER_BEGIN_EVT:
+			state = NODE_FAILINGOVER;
+			break;
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+		case NODE_SYNCH_END_EVT:
+		case NODE_FAILOVER_END_EVT:
+			break;
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case SELF_DOWN_PEER_LEAVING:
+		switch (evt) {
+		case PEER_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_DOWN;
+			break;
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+		case SELF_LOST_CONTACT_EVT:
+			break;
+		case NODE_SYNCH_END_EVT:
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_FAILOVER_BEGIN_EVT:
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case SELF_UP_PEER_COMING:
+		switch (evt) {
+		case PEER_ESTABL_CONTACT_EVT:
+			state = SELF_UP_PEER_UP;
+			break;
+		case SELF_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_DOWN;
+			break;
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_LOST_CONTACT_EVT:
+		case NODE_SYNCH_END_EVT:
+		case NODE_FAILOVER_BEGIN_EVT:
+			break;
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case SELF_COMING_PEER_UP:
+		switch (evt) {
+		case SELF_ESTABL_CONTACT_EVT:
+			state = SELF_UP_PEER_UP;
+			break;
+		case PEER_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_DOWN;
+			break;
+		case SELF_LOST_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+			break;
+		case NODE_SYNCH_END_EVT:
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_FAILOVER_BEGIN_EVT:
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case SELF_LEAVING_PEER_DOWN:
+		switch (evt) {
+		case SELF_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_DOWN;
+			break;
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+		case PEER_LOST_CONTACT_EVT:
+			break;
+		case NODE_SYNCH_END_EVT:
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_FAILOVER_BEGIN_EVT:
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case NODE_FAILINGOVER:
+		switch (evt) {
+		case SELF_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_LEAVING;
+			break;
+		case PEER_LOST_CONTACT_EVT:
+			state = SELF_LEAVING_PEER_DOWN;
+			break;
+		case NODE_FAILOVER_END_EVT:
+			state = SELF_UP_PEER_UP;
+			break;
+		case NODE_FAILOVER_BEGIN_EVT:
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+			break;
+		case NODE_SYNCH_BEGIN_EVT:
+		case NODE_SYNCH_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	case NODE_SYNCHING:
+		switch (evt) {
+		case SELF_LOST_CONTACT_EVT:
+			state = SELF_DOWN_PEER_LEAVING;
+			break;
+		case PEER_LOST_CONTACT_EVT:
+			state = SELF_LEAVING_PEER_DOWN;
+			break;
+		case NODE_SYNCH_END_EVT:
+			state = SELF_UP_PEER_UP;
+			break;
+		case NODE_FAILOVER_BEGIN_EVT:
+			state = NODE_FAILINGOVER;
+			break;
+		case NODE_SYNCH_BEGIN_EVT:
+		case SELF_ESTABL_CONTACT_EVT:
+		case PEER_ESTABL_CONTACT_EVT:
+			break;
+		case NODE_FAILOVER_END_EVT:
+		default:
+			goto illegal_evt;
+		}
+		break;
+	default:
+		pr_err("Unknown node fsm state %x\n", state);
+		break;
+	}
+	n->state = state;
+	return;
+
+illegal_evt:
+	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
+}
+
+static void node_lost_contact(struct tipc_node *n,
+			      struct sk_buff_head *inputq)
+{
+	struct tipc_sock_conn *conn, *safe;
+	struct tipc_link *l;
+	struct list_head *conns = &n->conn_sks;
+	struct sk_buff *skb;
+	uint i;
+
+	pr_debug("Lost contact with %x\n", n->addr);
+	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
+
+	/* Clean up broadcast state */
+	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
+
+	/* Abort any ongoing link failover */
+	for (i = 0; i < MAX_BEARERS; i++) {
+		l = n->links[i].link;
+		if (l)
+			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
+	}
+
+	/* Notify publications from this node */
+	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
+
+	/* Notify sockets connected to node */
+	list_for_each_entry_safe(conn, safe, conns, list) {
+		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
+				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
+				      conn->peer_node, conn->port,
+				      conn->peer_port, TIPC_ERR_NO_NODE);
+		if (likely(skb))
+			skb_queue_tail(inputq, skb);
+		list_del(&conn->list);
+		kfree(conn);
+	}
+}
+
+/**
+ * tipc_node_get_linkname - get the name of a link
+ *
+ * @bearer_id: id of the bearer
+ * @node: peer node address
+ * @linkname: link name output buffer
+ *
+ * Returns 0 on success
+ */
+int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
+			   char *linkname, size_t len)
+{
+	struct tipc_link *link;
+	int err = -EINVAL;
+	struct tipc_node *node = tipc_node_find(net, addr);
+
+	if (!node)
+		return err;
+
+	if (bearer_id >= MAX_BEARERS)
+		goto exit;
+
+	tipc_node_read_lock(node);
+	link = node->links[bearer_id].link;
+	if (link) {
+		strncpy(linkname, tipc_link_name(link), len);
+		err = 0;
+	}
+	tipc_node_read_unlock(node);
+exit:
+	tipc_node_put(node);
+	return err;
+}
+
+/* Caller should hold node lock for the passed node */
+static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
+{
+	void *hdr;
+	struct nlattr *attrs;
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+			  NLM_F_MULTI, TIPC_NL_NODE_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
+	if (!attrs)
+		goto msg_full;
+
+	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
+		goto attr_msg_full;
+	if (node_is_up(node))
+		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
+			goto attr_msg_full;
+
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+/**
+ * tipc_node_xmit() is the general link level function for message sending
+ * @net: the applicable net namespace
+ * @list: chain of buffers containing message
+ * @dnode: address of destination node
+ * @selector: a number used for deterministic link selection
+ * Consumes the buffer chain.
+ * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
+ */
+int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
+		   u32 dnode, int selector)
+{
+	struct tipc_link_entry *le = NULL;
+	struct tipc_node *n;
+	struct sk_buff_head xmitq;
+	int bearer_id;
+	int rc;
+
+	if (in_own_node(net, dnode)) {
+		tipc_sk_rcv(net, list);
+		return 0;
+	}
+
+	n = tipc_node_find(net, dnode);
+	if (unlikely(!n)) {
+		skb_queue_purge(list);
+		return -EHOSTUNREACH;
+	}
+
+	tipc_node_read_lock(n);
+	bearer_id = n->active_links[selector & 1];
+	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
+		tipc_node_read_unlock(n);
+		tipc_node_put(n);
+		skb_queue_purge(list);
+		return -EHOSTUNREACH;
+	}
+
+	__skb_queue_head_init(&xmitq);
+	le = &n->links[bearer_id];
+	spin_lock_bh(&le->lock);
+	rc = tipc_link_xmit(le->link, list, &xmitq);
+	spin_unlock_bh(&le->lock);
+	tipc_node_read_unlock(n);
+
+	if (unlikely(rc == -ENOBUFS))
+		tipc_node_link_down(n, bearer_id, false);
+	else
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+
+	tipc_node_put(n);
+
+	return rc;
+}
+
+/* tipc_node_xmit_skb(): send single buffer to destination
+ * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
+ * messages, which will not be rejected
+ * The only exception is datagram messages rerouted after secondary
+ * lookup, which are rare and safe to dispose of anyway.
+ */
+int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
+		       u32 selector)
+{
+	struct sk_buff_head head;
+
+	skb_queue_head_init(&head);
+	__skb_queue_tail(&head, skb);
+	tipc_node_xmit(net, &head, dnode, selector);
+	return 0;
+}
+
+/* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
+ * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
+ */
+int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
+{
+	struct sk_buff *skb;
+	u32 selector, dnode;
+
+	while ((skb = __skb_dequeue(xmitq))) {
+		selector = msg_origport(buf_msg(skb));
+		dnode = msg_destnode(buf_msg(skb));
+		tipc_node_xmit_skb(net, skb, dnode, selector);
+	}
+	return 0;
+}
+
+void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
+{
+	struct sk_buff *txskb;
+	struct tipc_node *n;
+	u32 dst;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
+		dst = n->addr;
+		if (in_own_node(net, dst))
+			continue;
+		if (!node_is_up(n))
+			continue;
+		txskb = pskb_copy(skb, GFP_ATOMIC);
+		if (!txskb)
+			break;
+		msg_set_destnode(buf_msg(txskb), dst);
+		tipc_node_xmit_skb(net, txskb, dst, 0);
+	}
+	rcu_read_unlock();
+
+	kfree_skb(skb);
+}
+
+static void tipc_node_mcast_rcv(struct tipc_node *n)
+{
+	struct tipc_bclink_entry *be = &n->bc_entry;
+
+	/* 'arrvq' is under inputq2's lock protection */
+	spin_lock_bh(&be->inputq2.lock);
+	spin_lock_bh(&be->inputq1.lock);
+	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
+	spin_unlock_bh(&be->inputq1.lock);
+	spin_unlock_bh(&be->inputq2.lock);
+	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
+}
+
+static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
+				  int bearer_id, struct sk_buff_head *xmitq)
+{
+	struct tipc_link *ucl;
+	int rc;
+
+	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
+
+	if (rc & TIPC_LINK_DOWN_EVT) {
+		tipc_node_reset_links(n);
+		return;
+	}
+
+	if (!(rc & TIPC_LINK_SND_STATE))
+		return;
+
+	/* If probe message, a STATE response will be sent anyway */
+	if (msg_probe(hdr))
+		return;
+
+	/* Produce a STATE message carrying broadcast NACK */
+	tipc_node_read_lock(n);
+	ucl = n->links[bearer_id].link;
+	if (ucl)
+		tipc_link_build_state_msg(ucl, xmitq);
+	tipc_node_read_unlock(n);
+}
+
+/**
+ * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
+ * @net: the applicable net namespace
+ * @skb: TIPC packet
+ * @bearer_id: id of bearer message arrived on
+ *
+ * Invoked with no locks held.
+ */
+static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
+{
+	int rc;
+	struct sk_buff_head xmitq;
+	struct tipc_bclink_entry *be;
+	struct tipc_link_entry *le;
+	struct tipc_msg *hdr = buf_msg(skb);
+	int usr = msg_user(hdr);
+	u32 dnode = msg_destnode(hdr);
+	struct tipc_node *n;
+
+	__skb_queue_head_init(&xmitq);
+
+	/* If NACK for other node, let rcv link for that node peek into it */
+	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
+		n = tipc_node_find(net, dnode);
+	else
+		n = tipc_node_find(net, msg_prevnode(hdr));
+	if (!n) {
+		kfree_skb(skb);
+		return;
+	}
+	be = &n->bc_entry;
+	le = &n->links[bearer_id];
+
+	rc = tipc_bcast_rcv(net, be->link, skb);
+
+	/* Broadcast ACKs are sent on a unicast link */
+	if (rc & TIPC_LINK_SND_STATE) {
+		tipc_node_read_lock(n);
+		tipc_link_build_state_msg(le->link, &xmitq);
+		tipc_node_read_unlock(n);
+	}
+
+	if (!skb_queue_empty(&xmitq))
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+
+	if (!skb_queue_empty(&be->inputq1))
+		tipc_node_mcast_rcv(n);
+
+	/* If reassembly or retransmission failure => reset all links to peer */
+	if (rc & TIPC_LINK_DOWN_EVT)
+		tipc_node_reset_links(n);
+
+	tipc_node_put(n);
+}
+
+/**
+ * tipc_node_check_state - check and if necessary update node state
+ * @skb: TIPC packet
+ * @bearer_id: identity of bearer delivering the packet
+ * Returns true if state and msg are ok, otherwise false
+ */
+static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
+				  int bearer_id, struct sk_buff_head *xmitq)
+{
+	struct tipc_msg *hdr = buf_msg(skb);
+	int usr = msg_user(hdr);
+	int mtyp = msg_type(hdr);
+	u16 oseqno = msg_seqno(hdr);
+	u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
+	u16 exp_pkts = msg_msgcnt(hdr);
+	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
+	int state = n->state;
+	struct tipc_link *l, *tnl, *pl = NULL;
+	struct tipc_media_addr *maddr;
+	int pb_id;
+
+	l = n->links[bearer_id].link;
+	if (!l)
+		return false;
+	rcv_nxt = tipc_link_rcv_nxt(l);
+
+
+	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
+		return true;
+
+	/* Find parallel link, if any */
+	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
+		if ((pb_id != bearer_id) && n->links[pb_id].link) {
+			pl = n->links[pb_id].link;
+			break;
+		}
+	}
+
+	if (!tipc_link_validate_msg(l, hdr))
+		return false;
+
+	/* Check and update node accesibility if applicable */
+	if (state == SELF_UP_PEER_COMING) {
+		if (!tipc_link_is_up(l))
+			return true;
+		if (!msg_peer_link_is_up(hdr))
+			return true;
+		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
+	}
+
+	if (state == SELF_DOWN_PEER_LEAVING) {
+		if (msg_peer_node_is_up(hdr))
+			return false;
+		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
+		return true;
+	}
+
+	if (state == SELF_LEAVING_PEER_DOWN)
+		return false;
+
+	/* Ignore duplicate packets */
+	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
+		return true;
+
+	/* Initiate or update failover mode if applicable */
+	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
+		syncpt = oseqno + exp_pkts - 1;
+		if (pl && tipc_link_is_up(pl)) {
+			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
+			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
+							tipc_link_inputq(l));
+		}
+		/* If parallel link was already down, and this happened before
+		 * the tunnel link came up, FAILOVER was never sent. Ensure that
+		 * FAILOVER is sent to get peer out of NODE_FAILINGOVER state.
+		 */
+		if (n->state != NODE_FAILINGOVER && !n->failover_sent) {
+			tipc_link_create_dummy_tnl_msg(l, xmitq);
+			n->failover_sent = true;
+		}
+		/* If pkts arrive out of order, use lowest calculated syncpt */
+		if (less(syncpt, n->sync_point))
+			n->sync_point = syncpt;
+	}
+
+	/* Open parallel link when tunnel link reaches synch point */
+	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
+		if (!more(rcv_nxt, n->sync_point))
+			return true;
+		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
+		if (pl)
+			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
+		return true;
+	}
+
+	/* No synching needed if only one link */
+	if (!pl || !tipc_link_is_up(pl))
+		return true;
+
+	/* Initiate synch mode if applicable */
+	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
+		syncpt = iseqno + exp_pkts - 1;
+		if (!tipc_link_is_up(l))
+			__tipc_node_link_up(n, bearer_id, xmitq);
+		if (n->state == SELF_UP_PEER_UP) {
+			n->sync_point = syncpt;
+			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
+			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
+		}
+	}
+
+	/* Open tunnel link when parallel link reaches synch point */
+	if (n->state == NODE_SYNCHING) {
+		if (tipc_link_is_synching(l)) {
+			tnl = l;
+		} else {
+			tnl = pl;
+			pl = l;
+		}
+		inputq_len = skb_queue_len(tipc_link_inputq(pl));
+		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
+		if (more(dlv_nxt, n->sync_point)) {
+			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
+			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
+			return true;
+		}
+		if (l == pl)
+			return true;
+		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
+			return true;
+		if (usr == LINK_PROTOCOL)
+			return true;
+		return false;
+	}
+	return true;
+}
+
+/**
+ * tipc_rcv - process TIPC packets/messages arriving from off-node
+ * @net: the applicable net namespace
+ * @skb: TIPC packet
+ * @bearer: pointer to bearer message arrived on
+ *
+ * Invoked with no locks held. Bearer pointer must point to a valid bearer
+ * structure (i.e. cannot be NULL), but bearer can be inactive.
+ */
+void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
+{
+	struct sk_buff_head xmitq;
+	struct tipc_node *n;
+	struct tipc_msg *hdr;
+	int bearer_id = b->identity;
+	struct tipc_link_entry *le;
+	u32 self = tipc_own_addr(net);
+	int usr, rc = 0;
+	u16 bc_ack;
+
+	__skb_queue_head_init(&xmitq);
+
+	/* Ensure message is well-formed before touching the header */
+	if (unlikely(!tipc_msg_validate(&skb)))
+		goto discard;
+	hdr = buf_msg(skb);
+	usr = msg_user(hdr);
+	bc_ack = msg_bcast_ack(hdr);
+
+	/* Handle arrival of discovery or broadcast packet */
+	if (unlikely(msg_non_seq(hdr))) {
+		if (unlikely(usr == LINK_CONFIG))
+			return tipc_disc_rcv(net, skb, b);
+		else
+			return tipc_node_bc_rcv(net, skb, bearer_id);
+	}
+
+	/* Discard unicast link messages destined for another node */
+	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
+		goto discard;
+
+	/* Locate neighboring node that sent packet */
+	n = tipc_node_find(net, msg_prevnode(hdr));
+	if (unlikely(!n))
+		goto discard;
+	le = &n->links[bearer_id];
+
+	/* Ensure broadcast reception is in synch with peer's send state */
+	if (unlikely(usr == LINK_PROTOCOL))
+		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
+	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
+		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
+
+	/* Receive packet directly if conditions permit */
+	tipc_node_read_lock(n);
+	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
+		spin_lock_bh(&le->lock);
+		if (le->link) {
+			rc = tipc_link_rcv(le->link, skb, &xmitq);
+			skb = NULL;
+		}
+		spin_unlock_bh(&le->lock);
+	}
+	tipc_node_read_unlock(n);
+
+	/* Check/update node state before receiving */
+	if (unlikely(skb)) {
+		if (unlikely(skb_linearize(skb)))
+			goto discard;
+		tipc_node_write_lock(n);
+		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
+			if (le->link) {
+				rc = tipc_link_rcv(le->link, skb, &xmitq);
+				skb = NULL;
+			}
+		}
+		tipc_node_write_unlock(n);
+	}
+
+	if (unlikely(rc & TIPC_LINK_UP_EVT))
+		tipc_node_link_up(n, bearer_id, &xmitq);
+
+	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
+		tipc_node_link_down(n, bearer_id, false);
+
+	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
+		tipc_named_rcv(net, &n->bc_entry.namedq);
+
+	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
+		tipc_node_mcast_rcv(n);
+
+	if (!skb_queue_empty(&le->inputq))
+		tipc_sk_rcv(net, &le->inputq);
+
+	if (!skb_queue_empty(&xmitq))
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
+
+	tipc_node_put(n);
+discard:
+	kfree_skb(skb);
+}
+
+void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
+			      int prop)
+{
+	struct tipc_net *tn = tipc_net(net);
+	int bearer_id = b->identity;
+	struct sk_buff_head xmitq;
+	struct tipc_link_entry *e;
+	struct tipc_node *n;
+
+	__skb_queue_head_init(&xmitq);
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(n, &tn->node_list, list) {
+		tipc_node_write_lock(n);
+		e = &n->links[bearer_id];
+		if (e->link) {
+			if (prop == TIPC_NLA_PROP_TOL)
+				tipc_link_set_tolerance(e->link, b->tolerance,
+							&xmitq);
+			else if (prop == TIPC_NLA_PROP_MTU)
+				tipc_link_set_mtu(e->link, b->mtu);
+		}
+		tipc_node_write_unlock(n);
+		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
+	}
+
+	rcu_read_unlock();
+}
+
+int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
+	struct tipc_node *peer;
+	u32 addr;
+	int err;
+
+	/* We identify the peer by its net */
+	if (!info->attrs[TIPC_NLA_NET])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
+			       info->attrs[TIPC_NLA_NET], tipc_nl_net_policy,
+			       info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_NET_ADDR])
+		return -EINVAL;
+
+	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
+
+	if (in_own_node(net, addr))
+		return -ENOTSUPP;
+
+	spin_lock_bh(&tn->node_list_lock);
+	peer = tipc_node_find(net, addr);
+	if (!peer) {
+		spin_unlock_bh(&tn->node_list_lock);
+		return -ENXIO;
+	}
+
+	tipc_node_write_lock(peer);
+	if (peer->state != SELF_DOWN_PEER_DOWN &&
+	    peer->state != SELF_DOWN_PEER_LEAVING) {
+		tipc_node_write_unlock(peer);
+		err = -EBUSY;
+		goto err_out;
+	}
+
+	tipc_node_clear_links(peer);
+	tipc_node_write_unlock(peer);
+	tipc_node_delete(peer);
+
+	err = 0;
+err_out:
+	tipc_node_put(peer);
+	spin_unlock_bh(&tn->node_list_lock);
+
+	return err;
+}
+
+int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	int done = cb->args[0];
+	int last_addr = cb->args[1];
+	struct tipc_node *node;
+	struct tipc_nl_msg msg;
+
+	if (done)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rcu_read_lock();
+	if (last_addr) {
+		node = tipc_node_find(net, last_addr);
+		if (!node) {
+			rcu_read_unlock();
+			/* We never set seq or call nl_dump_check_consistent()
+			 * this means that setting prev_seq here will cause the
+			 * consistence check to fail in the netlink callback
+			 * handler. Resulting in the NLMSG_DONE message having
+			 * the NLM_F_DUMP_INTR flag set if the node state
+			 * changed while we released the lock.
+			 */
+			cb->prev_seq = 1;
+			return -EPIPE;
+		}
+		tipc_node_put(node);
+	}
+
+	list_for_each_entry_rcu(node, &tn->node_list, list) {
+		if (last_addr) {
+			if (node->addr == last_addr)
+				last_addr = 0;
+			else
+				continue;
+		}
+
+		tipc_node_read_lock(node);
+		err = __tipc_nl_add_node(&msg, node);
+		if (err) {
+			last_addr = node->addr;
+			tipc_node_read_unlock(node);
+			goto out;
+		}
+
+		tipc_node_read_unlock(node);
+	}
+	done = 1;
+out:
+	cb->args[0] = done;
+	cb->args[1] = last_addr;
+	rcu_read_unlock();
+
+	return skb->len;
+}
+
+/* tipc_node_find_by_name - locate owner node of link by link's name
+ * @net: the applicable net namespace
+ * @name: pointer to link name string
+ * @bearer_id: pointer to index in 'node->links' array where the link was found.
+ *
+ * Returns pointer to node owning the link, or 0 if no matching link is found.
+ */
+static struct tipc_node *tipc_node_find_by_name(struct net *net,
+						const char *link_name,
+						unsigned int *bearer_id)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *l;
+	struct tipc_node *n;
+	struct tipc_node *found_node = NULL;
+	int i;
+
+	*bearer_id = 0;
+	rcu_read_lock();
+	list_for_each_entry_rcu(n, &tn->node_list, list) {
+		tipc_node_read_lock(n);
+		for (i = 0; i < MAX_BEARERS; i++) {
+			l = n->links[i].link;
+			if (l && !strcmp(tipc_link_name(l), link_name)) {
+				*bearer_id = i;
+				found_node = n;
+				break;
+			}
+		}
+		tipc_node_read_unlock(n);
+		if (found_node)
+			break;
+	}
+	rcu_read_unlock();
+
+	return found_node;
+}
+
+int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	int res = 0;
+	int bearer_id;
+	char *name;
+	struct tipc_link *link;
+	struct tipc_node *node;
+	struct sk_buff_head xmitq;
+	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+
+	__skb_queue_head_init(&xmitq);
+
+	if (!info->attrs[TIPC_NLA_LINK])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
+			       info->attrs[TIPC_NLA_LINK],
+			       tipc_nl_link_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+
+	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+
+	if (strcmp(name, tipc_bclink_name) == 0)
+		return tipc_nl_bc_link_set(net, attrs);
+
+	node = tipc_node_find_by_name(net, name, &bearer_id);
+	if (!node)
+		return -EINVAL;
+
+	tipc_node_read_lock(node);
+
+	link = node->links[bearer_id].link;
+	if (!link) {
+		res = -EINVAL;
+		goto out;
+	}
+
+	if (attrs[TIPC_NLA_LINK_PROP]) {
+		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
+					      props);
+		if (err) {
+			res = err;
+			goto out;
+		}
+
+		if (props[TIPC_NLA_PROP_TOL]) {
+			u32 tol;
+
+			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+			tipc_link_set_tolerance(link, tol, &xmitq);
+		}
+		if (props[TIPC_NLA_PROP_PRIO]) {
+			u32 prio;
+
+			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+			tipc_link_set_prio(link, prio, &xmitq);
+		}
+		if (props[TIPC_NLA_PROP_WIN]) {
+			u32 win;
+
+			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+			tipc_link_set_queue_limits(link, win);
+		}
+	}
+
+out:
+	tipc_node_read_unlock(node);
+	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
+	return res;
+}
+
+int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
+	struct tipc_nl_msg msg;
+	char *name;
+	int err;
+
+	msg.portid = info->snd_portid;
+	msg.seq = info->snd_seq;
+
+	if (!info->attrs[TIPC_NLA_LINK])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
+			       info->attrs[TIPC_NLA_LINK],
+			       tipc_nl_link_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+
+	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+
+	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg.skb)
+		return -ENOMEM;
+
+	if (strcmp(name, tipc_bclink_name) == 0) {
+		err = tipc_nl_add_bc_link(net, &msg);
+		if (err)
+			goto err_free;
+	} else {
+		int bearer_id;
+		struct tipc_node *node;
+		struct tipc_link *link;
+
+		node = tipc_node_find_by_name(net, name, &bearer_id);
+		if (!node) {
+			err = -EINVAL;
+			goto err_free;
+		}
+
+		tipc_node_read_lock(node);
+		link = node->links[bearer_id].link;
+		if (!link) {
+			tipc_node_read_unlock(node);
+			err = -EINVAL;
+			goto err_free;
+		}
+
+		err = __tipc_nl_add_link(net, &msg, link, 0);
+		tipc_node_read_unlock(node);
+		if (err)
+			goto err_free;
+	}
+
+	return genlmsg_reply(msg.skb, info);
+
+err_free:
+	nlmsg_free(msg.skb);
+	return err;
+}
+
+int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *link_name;
+	unsigned int bearer_id;
+	struct tipc_link *link;
+	struct tipc_node *node;
+	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	struct tipc_link_entry *le;
+
+	if (!info->attrs[TIPC_NLA_LINK])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
+			       info->attrs[TIPC_NLA_LINK],
+			       tipc_nl_link_policy, info->extack);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+
+	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+
+	if (strcmp(link_name, tipc_bclink_name) == 0) {
+		err = tipc_bclink_reset_stats(net);
+		if (err)
+			return err;
+		return 0;
+	}
+
+	node = tipc_node_find_by_name(net, link_name, &bearer_id);
+	if (!node)
+		return -EINVAL;
+
+	le = &node->links[bearer_id];
+	tipc_node_read_lock(node);
+	spin_lock_bh(&le->lock);
+	link = node->links[bearer_id].link;
+	if (!link) {
+		spin_unlock_bh(&le->lock);
+		tipc_node_read_unlock(node);
+		return -EINVAL;
+	}
+	tipc_link_reset_stats(link);
+	spin_unlock_bh(&le->lock);
+	tipc_node_read_unlock(node);
+	return 0;
+}
+
+/* Caller should hold node lock  */
+static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
+				    struct tipc_node *node, u32 *prev_link)
+{
+	u32 i;
+	int err;
+
+	for (i = *prev_link; i < MAX_BEARERS; i++) {
+		*prev_link = i;
+
+		if (!node->links[i].link)
+			continue;
+
+		err = __tipc_nl_add_link(net, msg,
+					 node->links[i].link, NLM_F_MULTI);
+		if (err)
+			return err;
+	}
+	*prev_link = 0;
+
+	return 0;
+}
+
+int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_node *node;
+	struct tipc_nl_msg msg;
+	u32 prev_node = cb->args[0];
+	u32 prev_link = cb->args[1];
+	int done = cb->args[2];
+	int err;
+
+	if (done)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rcu_read_lock();
+	if (prev_node) {
+		node = tipc_node_find(net, prev_node);
+		if (!node) {
+			/* We never set seq or call nl_dump_check_consistent()
+			 * this means that setting prev_seq here will cause the
+			 * consistence check to fail in the netlink callback
+			 * handler. Resulting in the last NLMSG_DONE message
+			 * having the NLM_F_DUMP_INTR flag set.
+			 */
+			cb->prev_seq = 1;
+			goto out;
+		}
+		tipc_node_put(node);
+
+		list_for_each_entry_continue_rcu(node, &tn->node_list,
+						 list) {
+			tipc_node_read_lock(node);
+			err = __tipc_nl_add_node_links(net, &msg, node,
+						       &prev_link);
+			tipc_node_read_unlock(node);
+			if (err)
+				goto out;
+
+			prev_node = node->addr;
+		}
+	} else {
+		err = tipc_nl_add_bc_link(net, &msg);
+		if (err)
+			goto out;
+
+		list_for_each_entry_rcu(node, &tn->node_list, list) {
+			tipc_node_read_lock(node);
+			err = __tipc_nl_add_node_links(net, &msg, node,
+						       &prev_link);
+			tipc_node_read_unlock(node);
+			if (err)
+				goto out;
+
+			prev_node = node->addr;
+		}
+	}
+	done = 1;
+out:
+	rcu_read_unlock();
+
+	cb->args[0] = prev_node;
+	cb->args[1] = prev_link;
+	cb->args[2] = done;
+
+	return skb->len;
+}
+
+int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	int err;
+
+	if (!info->attrs[TIPC_NLA_MON])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_MON_MAX,
+			       info->attrs[TIPC_NLA_MON],
+			       tipc_nl_monitor_policy, info->extack);
+	if (err)
+		return err;
+
+	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
+		u32 val;
+
+		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
+		err = tipc_nl_monitor_set_threshold(net, val);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
+{
+	struct nlattr *attrs;
+	void *hdr;
+	u32 val;
+
+	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
+			  0, TIPC_NL_MON_GET);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	attrs = nla_nest_start(msg->skb, TIPC_NLA_MON);
+	if (!attrs)
+		goto msg_full;
+
+	val = tipc_nl_monitor_get_threshold(net);
+
+	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
+		goto attr_msg_full;
+
+	nla_nest_end(msg->skb, attrs);
+	genlmsg_end(msg->skb, hdr);
+
+	return 0;
+
+attr_msg_full:
+	nla_nest_cancel(msg->skb, attrs);
+msg_full:
+	genlmsg_cancel(msg->skb, hdr);
+
+	return -EMSGSIZE;
+}
+
+int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_nl_msg msg;
+	int err;
+
+	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg.skb)
+		return -ENOMEM;
+	msg.portid = info->snd_portid;
+	msg.seq = info->snd_seq;
+
+	err = __tipc_nl_add_monitor_prop(net, &msg);
+	if (err) {
+		nlmsg_free(msg.skb);
+		return err;
+	}
+
+	return genlmsg_reply(msg.skb, info);
+}
+
+int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	u32 prev_bearer = cb->args[0];
+	struct tipc_nl_msg msg;
+	int bearer_id;
+	int err;
+
+	if (prev_bearer == MAX_BEARERS)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rtnl_lock();
+	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
+		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
+		if (err)
+			break;
+	}
+	rtnl_unlock();
+	cb->args[0] = bearer_id;
+
+	return skb->len;
+}
+
+int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
+				   struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	u32 prev_node = cb->args[1];
+	u32 bearer_id = cb->args[2];
+	int done = cb->args[0];
+	struct tipc_nl_msg msg;
+	int err;
+
+	if (!prev_node) {
+		struct nlattr **attrs;
+		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
+
+		err = tipc_nlmsg_parse(cb->nlh, &attrs);
+		if (err)
+			return err;
+
+		if (!attrs[TIPC_NLA_MON])
+			return -EINVAL;
+
+		err = nla_parse_nested(mon, TIPC_NLA_MON_MAX,
+				       attrs[TIPC_NLA_MON],
+				       tipc_nl_monitor_policy, NULL);
+		if (err)
+			return err;
+
+		if (!mon[TIPC_NLA_MON_REF])
+			return -EINVAL;
+
+		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
+
+		if (bearer_id >= MAX_BEARERS)
+			return -EINVAL;
+	}
+
+	if (done)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rtnl_lock();
+	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
+	if (!err)
+		done = 1;
+
+	rtnl_unlock();
+	cb->args[0] = done;
+	cb->args[1] = prev_node;
+	cb->args[2] = bearer_id;
+
+	return skb->len;
+}