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/net/tipc/node.c

http://github.com/mirrors/linux
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   1/*
   2 * net/tipc/node.c: TIPC node management routines
   3 *
   4 * Copyright (c) 2000-2006, 2012-2016, Ericsson AB
   5 * Copyright (c) 2005-2006, 2010-2014, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include "core.h"
  38#include "link.h"
  39#include "node.h"
  40#include "name_distr.h"
  41#include "socket.h"
  42#include "bcast.h"
  43#include "monitor.h"
  44#include "discover.h"
  45#include "netlink.h"
  46#include "trace.h"
  47#include "crypto.h"
  48
  49#define INVALID_NODE_SIG	0x10000
  50#define NODE_CLEANUP_AFTER	300000
  51
  52/* Flags used to take different actions according to flag type
  53 * TIPC_NOTIFY_NODE_DOWN: notify node is down
  54 * TIPC_NOTIFY_NODE_UP: notify node is up
  55 * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
  56 */
  57enum {
  58	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
  59	TIPC_NOTIFY_NODE_UP		= (1 << 4),
  60	TIPC_NOTIFY_LINK_UP		= (1 << 6),
  61	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
  62};
  63
  64struct tipc_link_entry {
  65	struct tipc_link *link;
  66	spinlock_t lock; /* per link */
  67	u32 mtu;
  68	struct sk_buff_head inputq;
  69	struct tipc_media_addr maddr;
  70};
  71
  72struct tipc_bclink_entry {
  73	struct tipc_link *link;
  74	struct sk_buff_head inputq1;
  75	struct sk_buff_head arrvq;
  76	struct sk_buff_head inputq2;
  77	struct sk_buff_head namedq;
  78};
  79
  80/**
  81 * struct tipc_node - TIPC node structure
  82 * @addr: network address of node
  83 * @ref: reference counter to node object
  84 * @lock: rwlock governing access to structure
  85 * @net: the applicable net namespace
  86 * @hash: links to adjacent nodes in unsorted hash chain
  87 * @inputq: pointer to input queue containing messages for msg event
  88 * @namedq: pointer to name table input queue with name table messages
  89 * @active_links: bearer ids of active links, used as index into links[] array
  90 * @links: array containing references to all links to node
  91 * @action_flags: bit mask of different types of node actions
  92 * @state: connectivity state vs peer node
  93 * @preliminary: a preliminary node or not
  94 * @sync_point: sequence number where synch/failover is finished
  95 * @list: links to adjacent nodes in sorted list of cluster's nodes
  96 * @working_links: number of working links to node (both active and standby)
  97 * @link_cnt: number of links to node
  98 * @capabilities: bitmap, indicating peer node's functional capabilities
  99 * @signature: node instance identifier
 100 * @link_id: local and remote bearer ids of changing link, if any
 101 * @publ_list: list of publications
 102 * @rcu: rcu struct for tipc_node
 103 * @delete_at: indicates the time for deleting a down node
 104 * @crypto_rx: RX crypto handler
 105 */
 106struct tipc_node {
 107	u32 addr;
 108	struct kref kref;
 109	rwlock_t lock;
 110	struct net *net;
 111	struct hlist_node hash;
 112	int active_links[2];
 113	struct tipc_link_entry links[MAX_BEARERS];
 114	struct tipc_bclink_entry bc_entry;
 115	int action_flags;
 116	struct list_head list;
 117	int state;
 118	bool preliminary;
 119	bool failover_sent;
 120	u16 sync_point;
 121	int link_cnt;
 122	u16 working_links;
 123	u16 capabilities;
 124	u32 signature;
 125	u32 link_id;
 126	u8 peer_id[16];
 127	char peer_id_string[NODE_ID_STR_LEN];
 128	struct list_head publ_list;
 129	struct list_head conn_sks;
 130	unsigned long keepalive_intv;
 131	struct timer_list timer;
 132	struct rcu_head rcu;
 133	unsigned long delete_at;
 134	struct net *peer_net;
 135	u32 peer_hash_mix;
 136#ifdef CONFIG_TIPC_CRYPTO
 137	struct tipc_crypto *crypto_rx;
 138#endif
 139};
 140
 141/* Node FSM states and events:
 142 */
 143enum {
 144	SELF_DOWN_PEER_DOWN    = 0xdd,
 145	SELF_UP_PEER_UP        = 0xaa,
 146	SELF_DOWN_PEER_LEAVING = 0xd1,
 147	SELF_UP_PEER_COMING    = 0xac,
 148	SELF_COMING_PEER_UP    = 0xca,
 149	SELF_LEAVING_PEER_DOWN = 0x1d,
 150	NODE_FAILINGOVER       = 0xf0,
 151	NODE_SYNCHING          = 0xcc
 152};
 153
 154enum {
 155	SELF_ESTABL_CONTACT_EVT = 0xece,
 156	SELF_LOST_CONTACT_EVT   = 0x1ce,
 157	PEER_ESTABL_CONTACT_EVT = 0x9ece,
 158	PEER_LOST_CONTACT_EVT   = 0x91ce,
 159	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
 160	NODE_FAILOVER_END_EVT   = 0xfee,
 161	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
 162	NODE_SYNCH_END_EVT      = 0xcee
 163};
 164
 165static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 166				  struct sk_buff_head *xmitq,
 167				  struct tipc_media_addr **maddr);
 168static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
 169				bool delete);
 170static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
 171static void tipc_node_delete(struct tipc_node *node);
 172static void tipc_node_timeout(struct timer_list *t);
 173static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
 174static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
 175static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
 176static bool node_is_up(struct tipc_node *n);
 177static void tipc_node_delete_from_list(struct tipc_node *node);
 178
 179struct tipc_sock_conn {
 180	u32 port;
 181	u32 peer_port;
 182	u32 peer_node;
 183	struct list_head list;
 184};
 185
 186static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
 187{
 188	int bearer_id = n->active_links[sel & 1];
 189
 190	if (unlikely(bearer_id == INVALID_BEARER_ID))
 191		return NULL;
 192
 193	return n->links[bearer_id].link;
 194}
 195
 196int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel, bool connected)
 197{
 198	struct tipc_node *n;
 199	int bearer_id;
 200	unsigned int mtu = MAX_MSG_SIZE;
 201
 202	n = tipc_node_find(net, addr);
 203	if (unlikely(!n))
 204		return mtu;
 205
 206	/* Allow MAX_MSG_SIZE when building connection oriented message
 207	 * if they are in the same core network
 208	 */
 209	if (n->peer_net && connected) {
 210		tipc_node_put(n);
 211		return mtu;
 212	}
 213
 214	bearer_id = n->active_links[sel & 1];
 215	if (likely(bearer_id != INVALID_BEARER_ID))
 216		mtu = n->links[bearer_id].mtu;
 217	tipc_node_put(n);
 218	return mtu;
 219}
 220
 221bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
 222{
 223	u8 *own_id = tipc_own_id(net);
 224	struct tipc_node *n;
 225
 226	if (!own_id)
 227		return true;
 228
 229	if (addr == tipc_own_addr(net)) {
 230		memcpy(id, own_id, TIPC_NODEID_LEN);
 231		return true;
 232	}
 233	n = tipc_node_find(net, addr);
 234	if (!n)
 235		return false;
 236
 237	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
 238	tipc_node_put(n);
 239	return true;
 240}
 241
 242u16 tipc_node_get_capabilities(struct net *net, u32 addr)
 243{
 244	struct tipc_node *n;
 245	u16 caps;
 246
 247	n = tipc_node_find(net, addr);
 248	if (unlikely(!n))
 249		return TIPC_NODE_CAPABILITIES;
 250	caps = n->capabilities;
 251	tipc_node_put(n);
 252	return caps;
 253}
 254
 255u32 tipc_node_get_addr(struct tipc_node *node)
 256{
 257	return (node) ? node->addr : 0;
 258}
 259
 260char *tipc_node_get_id_str(struct tipc_node *node)
 261{
 262	return node->peer_id_string;
 263}
 264
 265#ifdef CONFIG_TIPC_CRYPTO
 266/**
 267 * tipc_node_crypto_rx - Retrieve crypto RX handle from node
 268 * Note: node ref counter must be held first!
 269 */
 270struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n)
 271{
 272	return (__n) ? __n->crypto_rx : NULL;
 273}
 274
 275struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos)
 276{
 277	return container_of(pos, struct tipc_node, list)->crypto_rx;
 278}
 279#endif
 280
 281static void tipc_node_free(struct rcu_head *rp)
 282{
 283	struct tipc_node *n = container_of(rp, struct tipc_node, rcu);
 284
 285#ifdef CONFIG_TIPC_CRYPTO
 286	tipc_crypto_stop(&n->crypto_rx);
 287#endif
 288	kfree(n);
 289}
 290
 291static void tipc_node_kref_release(struct kref *kref)
 292{
 293	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
 294
 295	kfree(n->bc_entry.link);
 296	call_rcu(&n->rcu, tipc_node_free);
 297}
 298
 299void tipc_node_put(struct tipc_node *node)
 300{
 301	kref_put(&node->kref, tipc_node_kref_release);
 302}
 303
 304static void tipc_node_get(struct tipc_node *node)
 305{
 306	kref_get(&node->kref);
 307}
 308
 309/*
 310 * tipc_node_find - locate specified node object, if it exists
 311 */
 312static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
 313{
 314	struct tipc_net *tn = tipc_net(net);
 315	struct tipc_node *node;
 316	unsigned int thash = tipc_hashfn(addr);
 317
 318	rcu_read_lock();
 319	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
 320		if (node->addr != addr || node->preliminary)
 321			continue;
 322		if (!kref_get_unless_zero(&node->kref))
 323			node = NULL;
 324		break;
 325	}
 326	rcu_read_unlock();
 327	return node;
 328}
 329
 330/* tipc_node_find_by_id - locate specified node object by its 128-bit id
 331 * Note: this function is called only when a discovery request failed
 332 * to find the node by its 32-bit id, and is not time critical
 333 */
 334static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
 335{
 336	struct tipc_net *tn = tipc_net(net);
 337	struct tipc_node *n;
 338	bool found = false;
 339
 340	rcu_read_lock();
 341	list_for_each_entry_rcu(n, &tn->node_list, list) {
 342		read_lock_bh(&n->lock);
 343		if (!memcmp(id, n->peer_id, 16) &&
 344		    kref_get_unless_zero(&n->kref))
 345			found = true;
 346		read_unlock_bh(&n->lock);
 347		if (found)
 348			break;
 349	}
 350	rcu_read_unlock();
 351	return found ? n : NULL;
 352}
 353
 354static void tipc_node_read_lock(struct tipc_node *n)
 355{
 356	read_lock_bh(&n->lock);
 357}
 358
 359static void tipc_node_read_unlock(struct tipc_node *n)
 360{
 361	read_unlock_bh(&n->lock);
 362}
 363
 364static void tipc_node_write_lock(struct tipc_node *n)
 365{
 366	write_lock_bh(&n->lock);
 367}
 368
 369static void tipc_node_write_unlock_fast(struct tipc_node *n)
 370{
 371	write_unlock_bh(&n->lock);
 372}
 373
 374static void tipc_node_write_unlock(struct tipc_node *n)
 375{
 376	struct net *net = n->net;
 377	u32 addr = 0;
 378	u32 flags = n->action_flags;
 379	u32 link_id = 0;
 380	u32 bearer_id;
 381	struct list_head *publ_list;
 382
 383	if (likely(!flags)) {
 384		write_unlock_bh(&n->lock);
 385		return;
 386	}
 387
 388	addr = n->addr;
 389	link_id = n->link_id;
 390	bearer_id = link_id & 0xffff;
 391	publ_list = &n->publ_list;
 392
 393	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
 394			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
 395
 396	write_unlock_bh(&n->lock);
 397
 398	if (flags & TIPC_NOTIFY_NODE_DOWN)
 399		tipc_publ_notify(net, publ_list, addr);
 400
 401	if (flags & TIPC_NOTIFY_NODE_UP)
 402		tipc_named_node_up(net, addr);
 403
 404	if (flags & TIPC_NOTIFY_LINK_UP) {
 405		tipc_mon_peer_up(net, addr, bearer_id);
 406		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
 407				     TIPC_NODE_SCOPE, link_id, link_id);
 408	}
 409	if (flags & TIPC_NOTIFY_LINK_DOWN) {
 410		tipc_mon_peer_down(net, addr, bearer_id);
 411		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
 412				      addr, link_id);
 413	}
 414}
 415
 416static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
 417{
 418	int net_id = tipc_netid(n->net);
 419	struct tipc_net *tn_peer;
 420	struct net *tmp;
 421	u32 hash_chk;
 422
 423	if (n->peer_net)
 424		return;
 425
 426	for_each_net_rcu(tmp) {
 427		tn_peer = tipc_net(tmp);
 428		if (!tn_peer)
 429			continue;
 430		/* Integrity checking whether node exists in namespace or not */
 431		if (tn_peer->net_id != net_id)
 432			continue;
 433		if (memcmp(n->peer_id, tn_peer->node_id, NODE_ID_LEN))
 434			continue;
 435		hash_chk = tipc_net_hash_mixes(tmp, tn_peer->random);
 436		if (hash_mixes ^ hash_chk)
 437			continue;
 438		n->peer_net = tmp;
 439		n->peer_hash_mix = hash_mixes;
 440		break;
 441	}
 442}
 443
 444struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
 445				   u16 capabilities, u32 hash_mixes,
 446				   bool preliminary)
 447{
 448	struct tipc_net *tn = net_generic(net, tipc_net_id);
 449	struct tipc_node *n, *temp_node;
 450	struct tipc_link *l;
 451	unsigned long intv;
 452	int bearer_id;
 453	int i;
 454
 455	spin_lock_bh(&tn->node_list_lock);
 456	n = tipc_node_find(net, addr) ?:
 457		tipc_node_find_by_id(net, peer_id);
 458	if (n) {
 459		if (!n->preliminary)
 460			goto update;
 461		if (preliminary)
 462			goto exit;
 463		/* A preliminary node becomes "real" now, refresh its data */
 464		tipc_node_write_lock(n);
 465		n->preliminary = false;
 466		n->addr = addr;
 467		hlist_del_rcu(&n->hash);
 468		hlist_add_head_rcu(&n->hash,
 469				   &tn->node_htable[tipc_hashfn(addr)]);
 470		list_del_rcu(&n->list);
 471		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 472			if (n->addr < temp_node->addr)
 473				break;
 474		}
 475		list_add_tail_rcu(&n->list, &temp_node->list);
 476		tipc_node_write_unlock_fast(n);
 477
 478update:
 479		if (n->peer_hash_mix ^ hash_mixes)
 480			tipc_node_assign_peer_net(n, hash_mixes);
 481		if (n->capabilities == capabilities)
 482			goto exit;
 483		/* Same node may come back with new capabilities */
 484		tipc_node_write_lock(n);
 485		n->capabilities = capabilities;
 486		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
 487			l = n->links[bearer_id].link;
 488			if (l)
 489				tipc_link_update_caps(l, capabilities);
 490		}
 491		tipc_node_write_unlock_fast(n);
 492
 493		/* Calculate cluster capabilities */
 494		tn->capabilities = TIPC_NODE_CAPABILITIES;
 495		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 496			tn->capabilities &= temp_node->capabilities;
 497		}
 498
 499		tipc_bcast_toggle_rcast(net,
 500					(tn->capabilities & TIPC_BCAST_RCAST));
 501
 502		goto exit;
 503	}
 504	n = kzalloc(sizeof(*n), GFP_ATOMIC);
 505	if (!n) {
 506		pr_warn("Node creation failed, no memory\n");
 507		goto exit;
 508	}
 509	tipc_nodeid2string(n->peer_id_string, peer_id);
 510#ifdef CONFIG_TIPC_CRYPTO
 511	if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
 512		pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
 513		kfree(n);
 514		n = NULL;
 515		goto exit;
 516	}
 517#endif
 518	n->addr = addr;
 519	n->preliminary = preliminary;
 520	memcpy(&n->peer_id, peer_id, 16);
 521	n->net = net;
 522	n->peer_net = NULL;
 523	n->peer_hash_mix = 0;
 524	/* Assign kernel local namespace if exists */
 525	tipc_node_assign_peer_net(n, hash_mixes);
 526	n->capabilities = capabilities;
 527	kref_init(&n->kref);
 528	rwlock_init(&n->lock);
 529	INIT_HLIST_NODE(&n->hash);
 530	INIT_LIST_HEAD(&n->list);
 531	INIT_LIST_HEAD(&n->publ_list);
 532	INIT_LIST_HEAD(&n->conn_sks);
 533	skb_queue_head_init(&n->bc_entry.namedq);
 534	skb_queue_head_init(&n->bc_entry.inputq1);
 535	__skb_queue_head_init(&n->bc_entry.arrvq);
 536	skb_queue_head_init(&n->bc_entry.inputq2);
 537	for (i = 0; i < MAX_BEARERS; i++)
 538		spin_lock_init(&n->links[i].lock);
 539	n->state = SELF_DOWN_PEER_LEAVING;
 540	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
 541	n->signature = INVALID_NODE_SIG;
 542	n->active_links[0] = INVALID_BEARER_ID;
 543	n->active_links[1] = INVALID_BEARER_ID;
 544	n->bc_entry.link = NULL;
 545	tipc_node_get(n);
 546	timer_setup(&n->timer, tipc_node_timeout, 0);
 547	/* Start a slow timer anyway, crypto needs it */
 548	n->keepalive_intv = 10000;
 549	intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
 550	if (!mod_timer(&n->timer, intv))
 551		tipc_node_get(n);
 552	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
 553	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 554		if (n->addr < temp_node->addr)
 555			break;
 556	}
 557	list_add_tail_rcu(&n->list, &temp_node->list);
 558	/* Calculate cluster capabilities */
 559	tn->capabilities = TIPC_NODE_CAPABILITIES;
 560	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 561		tn->capabilities &= temp_node->capabilities;
 562	}
 563	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
 564	trace_tipc_node_create(n, true, " ");
 565exit:
 566	spin_unlock_bh(&tn->node_list_lock);
 567	return n;
 568}
 569
 570static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
 571{
 572	unsigned long tol = tipc_link_tolerance(l);
 573	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
 574
 575	/* Link with lowest tolerance determines timer interval */
 576	if (intv < n->keepalive_intv)
 577		n->keepalive_intv = intv;
 578
 579	/* Ensure link's abort limit corresponds to current tolerance */
 580	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
 581}
 582
 583static void tipc_node_delete_from_list(struct tipc_node *node)
 584{
 585	list_del_rcu(&node->list);
 586	hlist_del_rcu(&node->hash);
 587	tipc_node_put(node);
 588}
 589
 590static void tipc_node_delete(struct tipc_node *node)
 591{
 592	trace_tipc_node_delete(node, true, " ");
 593	tipc_node_delete_from_list(node);
 594
 595	del_timer_sync(&node->timer);
 596	tipc_node_put(node);
 597}
 598
 599void tipc_node_stop(struct net *net)
 600{
 601	struct tipc_net *tn = tipc_net(net);
 602	struct tipc_node *node, *t_node;
 603
 604	spin_lock_bh(&tn->node_list_lock);
 605	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
 606		tipc_node_delete(node);
 607	spin_unlock_bh(&tn->node_list_lock);
 608}
 609
 610void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
 611{
 612	struct tipc_node *n;
 613
 614	if (in_own_node(net, addr))
 615		return;
 616
 617	n = tipc_node_find(net, addr);
 618	if (!n) {
 619		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
 620		return;
 621	}
 622	tipc_node_write_lock(n);
 623	list_add_tail(subscr, &n->publ_list);
 624	tipc_node_write_unlock_fast(n);
 625	tipc_node_put(n);
 626}
 627
 628void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
 629{
 630	struct tipc_node *n;
 631
 632	if (in_own_node(net, addr))
 633		return;
 634
 635	n = tipc_node_find(net, addr);
 636	if (!n) {
 637		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
 638		return;
 639	}
 640	tipc_node_write_lock(n);
 641	list_del_init(subscr);
 642	tipc_node_write_unlock_fast(n);
 643	tipc_node_put(n);
 644}
 645
 646int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
 647{
 648	struct tipc_node *node;
 649	struct tipc_sock_conn *conn;
 650	int err = 0;
 651
 652	if (in_own_node(net, dnode))
 653		return 0;
 654
 655	node = tipc_node_find(net, dnode);
 656	if (!node) {
 657		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
 658		return -EHOSTUNREACH;
 659	}
 660	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
 661	if (!conn) {
 662		err = -EHOSTUNREACH;
 663		goto exit;
 664	}
 665	conn->peer_node = dnode;
 666	conn->port = port;
 667	conn->peer_port = peer_port;
 668
 669	tipc_node_write_lock(node);
 670	list_add_tail(&conn->list, &node->conn_sks);
 671	tipc_node_write_unlock(node);
 672exit:
 673	tipc_node_put(node);
 674	return err;
 675}
 676
 677void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
 678{
 679	struct tipc_node *node;
 680	struct tipc_sock_conn *conn, *safe;
 681
 682	if (in_own_node(net, dnode))
 683		return;
 684
 685	node = tipc_node_find(net, dnode);
 686	if (!node)
 687		return;
 688
 689	tipc_node_write_lock(node);
 690	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
 691		if (port != conn->port)
 692			continue;
 693		list_del(&conn->list);
 694		kfree(conn);
 695	}
 696	tipc_node_write_unlock(node);
 697	tipc_node_put(node);
 698}
 699
 700static void  tipc_node_clear_links(struct tipc_node *node)
 701{
 702	int i;
 703
 704	for (i = 0; i < MAX_BEARERS; i++) {
 705		struct tipc_link_entry *le = &node->links[i];
 706
 707		if (le->link) {
 708			kfree(le->link);
 709			le->link = NULL;
 710			node->link_cnt--;
 711		}
 712	}
 713}
 714
 715/* tipc_node_cleanup - delete nodes that does not
 716 * have active links for NODE_CLEANUP_AFTER time
 717 */
 718static bool tipc_node_cleanup(struct tipc_node *peer)
 719{
 720	struct tipc_node *temp_node;
 721	struct tipc_net *tn = tipc_net(peer->net);
 722	bool deleted = false;
 723
 724	/* If lock held by tipc_node_stop() the node will be deleted anyway */
 725	if (!spin_trylock_bh(&tn->node_list_lock))
 726		return false;
 727
 728	tipc_node_write_lock(peer);
 729
 730	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
 731		tipc_node_clear_links(peer);
 732		tipc_node_delete_from_list(peer);
 733		deleted = true;
 734	}
 735	tipc_node_write_unlock(peer);
 736
 737	if (!deleted) {
 738		spin_unlock_bh(&tn->node_list_lock);
 739		return deleted;
 740	}
 741
 742	/* Calculate cluster capabilities */
 743	tn->capabilities = TIPC_NODE_CAPABILITIES;
 744	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
 745		tn->capabilities &= temp_node->capabilities;
 746	}
 747	tipc_bcast_toggle_rcast(peer->net,
 748				(tn->capabilities & TIPC_BCAST_RCAST));
 749	spin_unlock_bh(&tn->node_list_lock);
 750	return deleted;
 751}
 752
 753/* tipc_node_timeout - handle expiration of node timer
 754 */
 755static void tipc_node_timeout(struct timer_list *t)
 756{
 757	struct tipc_node *n = from_timer(n, t, timer);
 758	struct tipc_link_entry *le;
 759	struct sk_buff_head xmitq;
 760	int remains = n->link_cnt;
 761	int bearer_id;
 762	int rc = 0;
 763
 764	trace_tipc_node_timeout(n, false, " ");
 765	if (!node_is_up(n) && tipc_node_cleanup(n)) {
 766		/*Removing the reference of Timer*/
 767		tipc_node_put(n);
 768		return;
 769	}
 770
 771#ifdef CONFIG_TIPC_CRYPTO
 772	/* Take any crypto key related actions first */
 773	tipc_crypto_timeout(n->crypto_rx);
 774#endif
 775	__skb_queue_head_init(&xmitq);
 776
 777	/* Initial node interval to value larger (10 seconds), then it will be
 778	 * recalculated with link lowest tolerance
 779	 */
 780	tipc_node_read_lock(n);
 781	n->keepalive_intv = 10000;
 782	tipc_node_read_unlock(n);
 783	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
 784		tipc_node_read_lock(n);
 785		le = &n->links[bearer_id];
 786		if (le->link) {
 787			spin_lock_bh(&le->lock);
 788			/* Link tolerance may change asynchronously: */
 789			tipc_node_calculate_timer(n, le->link);
 790			rc = tipc_link_timeout(le->link, &xmitq);
 791			spin_unlock_bh(&le->lock);
 792			remains--;
 793		}
 794		tipc_node_read_unlock(n);
 795		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr, n);
 796		if (rc & TIPC_LINK_DOWN_EVT)
 797			tipc_node_link_down(n, bearer_id, false);
 798	}
 799	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
 800}
 801
 802/**
 803 * __tipc_node_link_up - handle addition of link
 804 * Node lock must be held by caller
 805 * Link becomes active (alone or shared) or standby, depending on its priority.
 806 */
 807static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
 808				struct sk_buff_head *xmitq)
 809{
 810	int *slot0 = &n->active_links[0];
 811	int *slot1 = &n->active_links[1];
 812	struct tipc_link *ol = node_active_link(n, 0);
 813	struct tipc_link *nl = n->links[bearer_id].link;
 814
 815	if (!nl || tipc_link_is_up(nl))
 816		return;
 817
 818	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
 819	if (!tipc_link_is_up(nl))
 820		return;
 821
 822	n->working_links++;
 823	n->action_flags |= TIPC_NOTIFY_LINK_UP;
 824	n->link_id = tipc_link_id(nl);
 825
 826	/* Leave room for tunnel header when returning 'mtu' to users: */
 827	n->links[bearer_id].mtu = tipc_link_mss(nl);
 828
 829	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
 830	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
 831
 832	pr_debug("Established link <%s> on network plane %c\n",
 833		 tipc_link_name(nl), tipc_link_plane(nl));
 834	trace_tipc_node_link_up(n, true, " ");
 835
 836	/* Ensure that a STATE message goes first */
 837	tipc_link_build_state_msg(nl, xmitq);
 838
 839	/* First link? => give it both slots */
 840	if (!ol) {
 841		*slot0 = bearer_id;
 842		*slot1 = bearer_id;
 843		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
 844		n->action_flags |= TIPC_NOTIFY_NODE_UP;
 845		tipc_link_set_active(nl, true);
 846		tipc_bcast_add_peer(n->net, nl, xmitq);
 847		return;
 848	}
 849
 850	/* Second link => redistribute slots */
 851	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
 852		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
 853		*slot0 = bearer_id;
 854		*slot1 = bearer_id;
 855		tipc_link_set_active(nl, true);
 856		tipc_link_set_active(ol, false);
 857	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
 858		tipc_link_set_active(nl, true);
 859		*slot1 = bearer_id;
 860	} else {
 861		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
 862	}
 863
 864	/* Prepare synchronization with first link */
 865	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
 866}
 867
 868/**
 869 * tipc_node_link_up - handle addition of link
 870 *
 871 * Link becomes active (alone or shared) or standby, depending on its priority.
 872 */
 873static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
 874			      struct sk_buff_head *xmitq)
 875{
 876	struct tipc_media_addr *maddr;
 877
 878	tipc_node_write_lock(n);
 879	__tipc_node_link_up(n, bearer_id, xmitq);
 880	maddr = &n->links[bearer_id].maddr;
 881	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr, n);
 882	tipc_node_write_unlock(n);
 883}
 884
 885/**
 886 * tipc_node_link_failover() - start failover in case "half-failover"
 887 *
 888 * This function is only called in a very special situation where link
 889 * failover can be already started on peer node but not on this node.
 890 * This can happen when e.g.
 891 *	1. Both links <1A-2A>, <1B-2B> down
 892 *	2. Link endpoint 2A up, but 1A still down (e.g. due to network
 893 *	   disturbance, wrong session, etc.)
 894 *	3. Link <1B-2B> up
 895 *	4. Link endpoint 2A down (e.g. due to link tolerance timeout)
 896 *	5. Node 2 starts failover onto link <1B-2B>
 897 *
 898 *	==> Node 1 does never start link/node failover!
 899 *
 900 * @n: tipc node structure
 901 * @l: link peer endpoint failingover (- can be NULL)
 902 * @tnl: tunnel link
 903 * @xmitq: queue for messages to be xmited on tnl link later
 904 */
 905static void tipc_node_link_failover(struct tipc_node *n, struct tipc_link *l,
 906				    struct tipc_link *tnl,
 907				    struct sk_buff_head *xmitq)
 908{
 909	/* Avoid to be "self-failover" that can never end */
 910	if (!tipc_link_is_up(tnl))
 911		return;
 912
 913	/* Don't rush, failure link may be in the process of resetting */
 914	if (l && !tipc_link_is_reset(l))
 915		return;
 916
 917	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
 918	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
 919
 920	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
 921	tipc_link_failover_prepare(l, tnl, xmitq);
 922
 923	if (l)
 924		tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
 925	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
 926}
 927
 928/**
 929 * __tipc_node_link_down - handle loss of link
 930 */
 931static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 932				  struct sk_buff_head *xmitq,
 933				  struct tipc_media_addr **maddr)
 934{
 935	struct tipc_link_entry *le = &n->links[*bearer_id];
 936	int *slot0 = &n->active_links[0];
 937	int *slot1 = &n->active_links[1];
 938	int i, highest = 0, prio;
 939	struct tipc_link *l, *_l, *tnl;
 940
 941	l = n->links[*bearer_id].link;
 942	if (!l || tipc_link_is_reset(l))
 943		return;
 944
 945	n->working_links--;
 946	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
 947	n->link_id = tipc_link_id(l);
 948
 949	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
 950
 951	pr_debug("Lost link <%s> on network plane %c\n",
 952		 tipc_link_name(l), tipc_link_plane(l));
 953
 954	/* Select new active link if any available */
 955	*slot0 = INVALID_BEARER_ID;
 956	*slot1 = INVALID_BEARER_ID;
 957	for (i = 0; i < MAX_BEARERS; i++) {
 958		_l = n->links[i].link;
 959		if (!_l || !tipc_link_is_up(_l))
 960			continue;
 961		if (_l == l)
 962			continue;
 963		prio = tipc_link_prio(_l);
 964		if (prio < highest)
 965			continue;
 966		if (prio > highest) {
 967			highest = prio;
 968			*slot0 = i;
 969			*slot1 = i;
 970			continue;
 971		}
 972		*slot1 = i;
 973	}
 974
 975	if (!node_is_up(n)) {
 976		if (tipc_link_peer_is_down(l))
 977			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
 978		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
 979		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
 980		tipc_link_fsm_evt(l, LINK_RESET_EVT);
 981		tipc_link_reset(l);
 982		tipc_link_build_reset_msg(l, xmitq);
 983		*maddr = &n->links[*bearer_id].maddr;
 984		node_lost_contact(n, &le->inputq);
 985		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
 986		return;
 987	}
 988	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
 989
 990	/* There is still a working link => initiate failover */
 991	*bearer_id = n->active_links[0];
 992	tnl = n->links[*bearer_id].link;
 993	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
 994	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
 995	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
 996	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
 997	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
 998	tipc_link_reset(l);
 999	tipc_link_fsm_evt(l, LINK_RESET_EVT);
1000	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1001	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
1002	*maddr = &n->links[*bearer_id].maddr;
1003}
1004
1005static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
1006{
1007	struct tipc_link_entry *le = &n->links[bearer_id];
1008	struct tipc_media_addr *maddr = NULL;
1009	struct tipc_link *l = le->link;
1010	int old_bearer_id = bearer_id;
1011	struct sk_buff_head xmitq;
1012
1013	if (!l)
1014		return;
1015
1016	__skb_queue_head_init(&xmitq);
1017
1018	tipc_node_write_lock(n);
1019	if (!tipc_link_is_establishing(l)) {
1020		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
1021	} else {
1022		/* Defuse pending tipc_node_link_up() */
1023		tipc_link_reset(l);
1024		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1025	}
1026	if (delete) {
1027		kfree(l);
1028		le->link = NULL;
1029		n->link_cnt--;
1030	}
1031	trace_tipc_node_link_down(n, true, "node link down or deleted!");
1032	tipc_node_write_unlock(n);
1033	if (delete)
1034		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
1035	if (!skb_queue_empty(&xmitq))
1036		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr, n);
1037	tipc_sk_rcv(n->net, &le->inputq);
1038}
1039
1040static bool node_is_up(struct tipc_node *n)
1041{
1042	return n->active_links[0] != INVALID_BEARER_ID;
1043}
1044
1045bool tipc_node_is_up(struct net *net, u32 addr)
1046{
1047	struct tipc_node *n;
1048	bool retval = false;
1049
1050	if (in_own_node(net, addr))
1051		return true;
1052
1053	n = tipc_node_find(net, addr);
1054	if (!n)
1055		return false;
1056	retval = node_is_up(n);
1057	tipc_node_put(n);
1058	return retval;
1059}
1060
1061static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
1062{
1063	struct tipc_node *n;
1064
1065	addr ^= tipc_net(net)->random;
1066	while ((n = tipc_node_find(net, addr))) {
1067		tipc_node_put(n);
1068		addr++;
1069	}
1070	return addr;
1071}
1072
1073/* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
1074 * Returns suggested address if any, otherwise 0
1075 */
1076u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
1077{
1078	struct tipc_net *tn = tipc_net(net);
1079	struct tipc_node *n;
1080	bool preliminary;
1081	u32 sugg_addr;
1082
1083	/* Suggest new address if some other peer is using this one */
1084	n = tipc_node_find(net, addr);
1085	if (n) {
1086		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
1087			addr = 0;
1088		tipc_node_put(n);
1089		if (!addr)
1090			return 0;
1091		return tipc_node_suggest_addr(net, addr);
1092	}
1093
1094	/* Suggest previously used address if peer is known */
1095	n = tipc_node_find_by_id(net, id);
1096	if (n) {
1097		sugg_addr = n->addr;
1098		preliminary = n->preliminary;
1099		tipc_node_put(n);
1100		if (!preliminary)
1101			return sugg_addr;
1102	}
1103
1104	/* Even this node may be in conflict */
1105	if (tn->trial_addr == addr)
1106		return tipc_node_suggest_addr(net, addr);
1107
1108	return 0;
1109}
1110
1111void tipc_node_check_dest(struct net *net, u32 addr,
1112			  u8 *peer_id, struct tipc_bearer *b,
1113			  u16 capabilities, u32 signature, u32 hash_mixes,
1114			  struct tipc_media_addr *maddr,
1115			  bool *respond, bool *dupl_addr)
1116{
1117	struct tipc_node *n;
1118	struct tipc_link *l, *snd_l;
1119	struct tipc_link_entry *le;
1120	bool addr_match = false;
1121	bool sign_match = false;
1122	bool link_up = false;
1123	bool accept_addr = false;
1124	bool reset = true;
1125	char *if_name;
1126	unsigned long intv;
1127	u16 session;
1128
1129	*dupl_addr = false;
1130	*respond = false;
1131
1132	n = tipc_node_create(net, addr, peer_id, capabilities, hash_mixes,
1133			     false);
1134	if (!n)
1135		return;
1136
1137	tipc_node_write_lock(n);
1138	if (unlikely(!n->bc_entry.link)) {
1139		snd_l = tipc_bc_sndlink(net);
1140		if (!tipc_link_bc_create(net, tipc_own_addr(net),
1141					 addr, U16_MAX,
1142					 tipc_link_min_win(snd_l),
1143					 tipc_link_max_win(snd_l),
1144					 n->capabilities,
1145					 &n->bc_entry.inputq1,
1146					 &n->bc_entry.namedq, snd_l,
1147					 &n->bc_entry.link)) {
1148			pr_warn("Broadcast rcv link creation failed, no mem\n");
1149			tipc_node_write_unlock_fast(n);
1150			tipc_node_put(n);
1151			return;
1152		}
1153	}
1154
1155	le = &n->links[b->identity];
1156
1157	/* Prepare to validate requesting node's signature and media address */
1158	l = le->link;
1159	link_up = l && tipc_link_is_up(l);
1160	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1161	sign_match = (signature == n->signature);
1162
1163	/* These three flags give us eight permutations: */
1164
1165	if (sign_match && addr_match && link_up) {
1166		/* All is fine. Do nothing. */
1167		reset = false;
1168		/* Peer node is not a container/local namespace */
1169		if (!n->peer_hash_mix)
1170			n->peer_hash_mix = hash_mixes;
1171	} else if (sign_match && addr_match && !link_up) {
1172		/* Respond. The link will come up in due time */
1173		*respond = true;
1174	} else if (sign_match && !addr_match && link_up) {
1175		/* Peer has changed i/f address without rebooting.
1176		 * If so, the link will reset soon, and the next
1177		 * discovery will be accepted. So we can ignore it.
1178		 * It may also be an cloned or malicious peer having
1179		 * chosen the same node address and signature as an
1180		 * existing one.
1181		 * Ignore requests until the link goes down, if ever.
1182		 */
1183		*dupl_addr = true;
1184	} else if (sign_match && !addr_match && !link_up) {
1185		/* Peer link has changed i/f address without rebooting.
1186		 * It may also be a cloned or malicious peer; we can't
1187		 * distinguish between the two.
1188		 * The signature is correct, so we must accept.
1189		 */
1190		accept_addr = true;
1191		*respond = true;
1192	} else if (!sign_match && addr_match && link_up) {
1193		/* Peer node rebooted. Two possibilities:
1194		 *  - Delayed re-discovery; this link endpoint has already
1195		 *    reset and re-established contact with the peer, before
1196		 *    receiving a discovery message from that node.
1197		 *    (The peer happened to receive one from this node first).
1198		 *  - The peer came back so fast that our side has not
1199		 *    discovered it yet. Probing from this side will soon
1200		 *    reset the link, since there can be no working link
1201		 *    endpoint at the peer end, and the link will re-establish.
1202		 *  Accept the signature, since it comes from a known peer.
1203		 */
1204		n->signature = signature;
1205	} else if (!sign_match && addr_match && !link_up) {
1206		/*  The peer node has rebooted.
1207		 *  Accept signature, since it is a known peer.
1208		 */
1209		n->signature = signature;
1210		*respond = true;
1211	} else if (!sign_match && !addr_match && link_up) {
1212		/* Peer rebooted with new address, or a new/duplicate peer.
1213		 * Ignore until the link goes down, if ever.
1214		 */
1215		*dupl_addr = true;
1216	} else if (!sign_match && !addr_match && !link_up) {
1217		/* Peer rebooted with new address, or it is a new peer.
1218		 * Accept signature and address.
1219		 */
1220		n->signature = signature;
1221		accept_addr = true;
1222		*respond = true;
1223	}
1224
1225	if (!accept_addr)
1226		goto exit;
1227
1228	/* Now create new link if not already existing */
1229	if (!l) {
1230		if (n->link_cnt == 2)
1231			goto exit;
1232
1233		if_name = strchr(b->name, ':') + 1;
1234		get_random_bytes(&session, sizeof(u16));
1235		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1236				      b->net_plane, b->mtu, b->priority,
1237				      b->min_win, b->max_win, session,
1238				      tipc_own_addr(net), addr, peer_id,
1239				      n->capabilities,
1240				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1241				      &le->inputq,
1242				      &n->bc_entry.namedq, &l)) {
1243			*respond = false;
1244			goto exit;
1245		}
1246		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1247		tipc_link_reset(l);
1248		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1249		if (n->state == NODE_FAILINGOVER)
1250			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1251		le->link = l;
1252		n->link_cnt++;
1253		tipc_node_calculate_timer(n, l);
1254		if (n->link_cnt == 1) {
1255			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1256			if (!mod_timer(&n->timer, intv))
1257				tipc_node_get(n);
1258		}
1259	}
1260	memcpy(&le->maddr, maddr, sizeof(*maddr));
1261exit:
1262	tipc_node_write_unlock(n);
1263	if (reset && l && !tipc_link_is_reset(l))
1264		tipc_node_link_down(n, b->identity, false);
1265	tipc_node_put(n);
1266}
1267
1268void tipc_node_delete_links(struct net *net, int bearer_id)
1269{
1270	struct tipc_net *tn = net_generic(net, tipc_net_id);
1271	struct tipc_node *n;
1272
1273	rcu_read_lock();
1274	list_for_each_entry_rcu(n, &tn->node_list, list) {
1275		tipc_node_link_down(n, bearer_id, true);
1276	}
1277	rcu_read_unlock();
1278}
1279
1280static void tipc_node_reset_links(struct tipc_node *n)
1281{
1282	int i;
1283
1284	pr_warn("Resetting all links to %x\n", n->addr);
1285
1286	trace_tipc_node_reset_links(n, true, " ");
1287	for (i = 0; i < MAX_BEARERS; i++) {
1288		tipc_node_link_down(n, i, false);
1289	}
1290}
1291
1292/* tipc_node_fsm_evt - node finite state machine
1293 * Determines when contact is allowed with peer node
1294 */
1295static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1296{
1297	int state = n->state;
1298
1299	switch (state) {
1300	case SELF_DOWN_PEER_DOWN:
1301		switch (evt) {
1302		case SELF_ESTABL_CONTACT_EVT:
1303			state = SELF_UP_PEER_COMING;
1304			break;
1305		case PEER_ESTABL_CONTACT_EVT:
1306			state = SELF_COMING_PEER_UP;
1307			break;
1308		case SELF_LOST_CONTACT_EVT:
1309		case PEER_LOST_CONTACT_EVT:
1310			break;
1311		case NODE_SYNCH_END_EVT:
1312		case NODE_SYNCH_BEGIN_EVT:
1313		case NODE_FAILOVER_BEGIN_EVT:
1314		case NODE_FAILOVER_END_EVT:
1315		default:
1316			goto illegal_evt;
1317		}
1318		break;
1319	case SELF_UP_PEER_UP:
1320		switch (evt) {
1321		case SELF_LOST_CONTACT_EVT:
1322			state = SELF_DOWN_PEER_LEAVING;
1323			break;
1324		case PEER_LOST_CONTACT_EVT:
1325			state = SELF_LEAVING_PEER_DOWN;
1326			break;
1327		case NODE_SYNCH_BEGIN_EVT:
1328			state = NODE_SYNCHING;
1329			break;
1330		case NODE_FAILOVER_BEGIN_EVT:
1331			state = NODE_FAILINGOVER;
1332			break;
1333		case SELF_ESTABL_CONTACT_EVT:
1334		case PEER_ESTABL_CONTACT_EVT:
1335		case NODE_SYNCH_END_EVT:
1336		case NODE_FAILOVER_END_EVT:
1337			break;
1338		default:
1339			goto illegal_evt;
1340		}
1341		break;
1342	case SELF_DOWN_PEER_LEAVING:
1343		switch (evt) {
1344		case PEER_LOST_CONTACT_EVT:
1345			state = SELF_DOWN_PEER_DOWN;
1346			break;
1347		case SELF_ESTABL_CONTACT_EVT:
1348		case PEER_ESTABL_CONTACT_EVT:
1349		case SELF_LOST_CONTACT_EVT:
1350			break;
1351		case NODE_SYNCH_END_EVT:
1352		case NODE_SYNCH_BEGIN_EVT:
1353		case NODE_FAILOVER_BEGIN_EVT:
1354		case NODE_FAILOVER_END_EVT:
1355		default:
1356			goto illegal_evt;
1357		}
1358		break;
1359	case SELF_UP_PEER_COMING:
1360		switch (evt) {
1361		case PEER_ESTABL_CONTACT_EVT:
1362			state = SELF_UP_PEER_UP;
1363			break;
1364		case SELF_LOST_CONTACT_EVT:
1365			state = SELF_DOWN_PEER_DOWN;
1366			break;
1367		case SELF_ESTABL_CONTACT_EVT:
1368		case PEER_LOST_CONTACT_EVT:
1369		case NODE_SYNCH_END_EVT:
1370		case NODE_FAILOVER_BEGIN_EVT:
1371			break;
1372		case NODE_SYNCH_BEGIN_EVT:
1373		case NODE_FAILOVER_END_EVT:
1374		default:
1375			goto illegal_evt;
1376		}
1377		break;
1378	case SELF_COMING_PEER_UP:
1379		switch (evt) {
1380		case SELF_ESTABL_CONTACT_EVT:
1381			state = SELF_UP_PEER_UP;
1382			break;
1383		case PEER_LOST_CONTACT_EVT:
1384			state = SELF_DOWN_PEER_DOWN;
1385			break;
1386		case SELF_LOST_CONTACT_EVT:
1387		case PEER_ESTABL_CONTACT_EVT:
1388			break;
1389		case NODE_SYNCH_END_EVT:
1390		case NODE_SYNCH_BEGIN_EVT:
1391		case NODE_FAILOVER_BEGIN_EVT:
1392		case NODE_FAILOVER_END_EVT:
1393		default:
1394			goto illegal_evt;
1395		}
1396		break;
1397	case SELF_LEAVING_PEER_DOWN:
1398		switch (evt) {
1399		case SELF_LOST_CONTACT_EVT:
1400			state = SELF_DOWN_PEER_DOWN;
1401			break;
1402		case SELF_ESTABL_CONTACT_EVT:
1403		case PEER_ESTABL_CONTACT_EVT:
1404		case PEER_LOST_CONTACT_EVT:
1405			break;
1406		case NODE_SYNCH_END_EVT:
1407		case NODE_SYNCH_BEGIN_EVT:
1408		case NODE_FAILOVER_BEGIN_EVT:
1409		case NODE_FAILOVER_END_EVT:
1410		default:
1411			goto illegal_evt;
1412		}
1413		break;
1414	case NODE_FAILINGOVER:
1415		switch (evt) {
1416		case SELF_LOST_CONTACT_EVT:
1417			state = SELF_DOWN_PEER_LEAVING;
1418			break;
1419		case PEER_LOST_CONTACT_EVT:
1420			state = SELF_LEAVING_PEER_DOWN;
1421			break;
1422		case NODE_FAILOVER_END_EVT:
1423			state = SELF_UP_PEER_UP;
1424			break;
1425		case NODE_FAILOVER_BEGIN_EVT:
1426		case SELF_ESTABL_CONTACT_EVT:
1427		case PEER_ESTABL_CONTACT_EVT:
1428			break;
1429		case NODE_SYNCH_BEGIN_EVT:
1430		case NODE_SYNCH_END_EVT:
1431		default:
1432			goto illegal_evt;
1433		}
1434		break;
1435	case NODE_SYNCHING:
1436		switch (evt) {
1437		case SELF_LOST_CONTACT_EVT:
1438			state = SELF_DOWN_PEER_LEAVING;
1439			break;
1440		case PEER_LOST_CONTACT_EVT:
1441			state = SELF_LEAVING_PEER_DOWN;
1442			break;
1443		case NODE_SYNCH_END_EVT:
1444			state = SELF_UP_PEER_UP;
1445			break;
1446		case NODE_FAILOVER_BEGIN_EVT:
1447			state = NODE_FAILINGOVER;
1448			break;
1449		case NODE_SYNCH_BEGIN_EVT:
1450		case SELF_ESTABL_CONTACT_EVT:
1451		case PEER_ESTABL_CONTACT_EVT:
1452			break;
1453		case NODE_FAILOVER_END_EVT:
1454		default:
1455			goto illegal_evt;
1456		}
1457		break;
1458	default:
1459		pr_err("Unknown node fsm state %x\n", state);
1460		break;
1461	}
1462	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1463	n->state = state;
1464	return;
1465
1466illegal_evt:
1467	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1468	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1469}
1470
1471static void node_lost_contact(struct tipc_node *n,
1472			      struct sk_buff_head *inputq)
1473{
1474	struct tipc_sock_conn *conn, *safe;
1475	struct tipc_link *l;
1476	struct list_head *conns = &n->conn_sks;
1477	struct sk_buff *skb;
1478	uint i;
1479
1480	pr_debug("Lost contact with %x\n", n->addr);
1481	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1482	trace_tipc_node_lost_contact(n, true, " ");
1483
1484	/* Clean up broadcast state */
1485	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1486
1487	/* Abort any ongoing link failover */
1488	for (i = 0; i < MAX_BEARERS; i++) {
1489		l = n->links[i].link;
1490		if (l)
1491			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1492	}
1493
1494	/* Notify publications from this node */
1495	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1496	n->peer_net = NULL;
1497	n->peer_hash_mix = 0;
1498	/* Notify sockets connected to node */
1499	list_for_each_entry_safe(conn, safe, conns, list) {
1500		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1501				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1502				      conn->peer_node, conn->port,
1503				      conn->peer_port, TIPC_ERR_NO_NODE);
1504		if (likely(skb))
1505			skb_queue_tail(inputq, skb);
1506		list_del(&conn->list);
1507		kfree(conn);
1508	}
1509}
1510
1511/**
1512 * tipc_node_get_linkname - get the name of a link
1513 *
1514 * @bearer_id: id of the bearer
1515 * @node: peer node address
1516 * @linkname: link name output buffer
1517 *
1518 * Returns 0 on success
1519 */
1520int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1521			   char *linkname, size_t len)
1522{
1523	struct tipc_link *link;
1524	int err = -EINVAL;
1525	struct tipc_node *node = tipc_node_find(net, addr);
1526
1527	if (!node)
1528		return err;
1529
1530	if (bearer_id >= MAX_BEARERS)
1531		goto exit;
1532
1533	tipc_node_read_lock(node);
1534	link = node->links[bearer_id].link;
1535	if (link) {
1536		strncpy(linkname, tipc_link_name(link), len);
1537		err = 0;
1538	}
1539	tipc_node_read_unlock(node);
1540exit:
1541	tipc_node_put(node);
1542	return err;
1543}
1544
1545/* Caller should hold node lock for the passed node */
1546static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1547{
1548	void *hdr;
1549	struct nlattr *attrs;
1550
1551	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1552			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1553	if (!hdr)
1554		return -EMSGSIZE;
1555
1556	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1557	if (!attrs)
1558		goto msg_full;
1559
1560	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1561		goto attr_msg_full;
1562	if (node_is_up(node))
1563		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1564			goto attr_msg_full;
1565
1566	nla_nest_end(msg->skb, attrs);
1567	genlmsg_end(msg->skb, hdr);
1568
1569	return 0;
1570
1571attr_msg_full:
1572	nla_nest_cancel(msg->skb, attrs);
1573msg_full:
1574	genlmsg_cancel(msg->skb, hdr);
1575
1576	return -EMSGSIZE;
1577}
1578
1579static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)
1580{
1581	struct tipc_msg *hdr = buf_msg(skb_peek(list));
1582	struct sk_buff_head inputq;
1583
1584	switch (msg_user(hdr)) {
1585	case TIPC_LOW_IMPORTANCE:
1586	case TIPC_MEDIUM_IMPORTANCE:
1587	case TIPC_HIGH_IMPORTANCE:
1588	case TIPC_CRITICAL_IMPORTANCE:
1589		if (msg_connected(hdr) || msg_named(hdr) ||
1590		    msg_direct(hdr)) {
1591			tipc_loopback_trace(peer_net, list);
1592			spin_lock_init(&list->lock);
1593			tipc_sk_rcv(peer_net, list);
1594			return;
1595		}
1596		if (msg_mcast(hdr)) {
1597			tipc_loopback_trace(peer_net, list);
1598			skb_queue_head_init(&inputq);
1599			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1600			__skb_queue_purge(list);
1601			skb_queue_purge(&inputq);
1602			return;
1603		}
1604		return;
1605	case MSG_FRAGMENTER:
1606		if (tipc_msg_assemble(list)) {
1607			tipc_loopback_trace(peer_net, list);
1608			skb_queue_head_init(&inputq);
1609			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1610			__skb_queue_purge(list);
1611			skb_queue_purge(&inputq);
1612		}
1613		return;
1614	case GROUP_PROTOCOL:
1615	case CONN_MANAGER:
1616		tipc_loopback_trace(peer_net, list);
1617		spin_lock_init(&list->lock);
1618		tipc_sk_rcv(peer_net, list);
1619		return;
1620	case LINK_PROTOCOL:
1621	case NAME_DISTRIBUTOR:
1622	case TUNNEL_PROTOCOL:
1623	case BCAST_PROTOCOL:
1624		return;
1625	default:
1626		return;
1627	};
1628}
1629
1630/**
1631 * tipc_node_xmit() is the general link level function for message sending
1632 * @net: the applicable net namespace
1633 * @list: chain of buffers containing message
1634 * @dnode: address of destination node
1635 * @selector: a number used for deterministic link selection
1636 * Consumes the buffer chain.
1637 * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1638 */
1639int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1640		   u32 dnode, int selector)
1641{
1642	struct tipc_link_entry *le = NULL;
1643	struct tipc_node *n;
1644	struct sk_buff_head xmitq;
1645	bool node_up = false;
1646	int bearer_id;
1647	int rc;
1648
1649	if (in_own_node(net, dnode)) {
1650		tipc_loopback_trace(net, list);
1651		spin_lock_init(&list->lock);
1652		tipc_sk_rcv(net, list);
1653		return 0;
1654	}
1655
1656	n = tipc_node_find(net, dnode);
1657	if (unlikely(!n)) {
1658		__skb_queue_purge(list);
1659		return -EHOSTUNREACH;
1660	}
1661
1662	tipc_node_read_lock(n);
1663	node_up = node_is_up(n);
1664	if (node_up && n->peer_net && check_net(n->peer_net)) {
1665		/* xmit inner linux container */
1666		tipc_lxc_xmit(n->peer_net, list);
1667		if (likely(skb_queue_empty(list))) {
1668			tipc_node_read_unlock(n);
1669			tipc_node_put(n);
1670			return 0;
1671		}
1672	}
1673
1674	bearer_id = n->active_links[selector & 1];
1675	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1676		tipc_node_read_unlock(n);
1677		tipc_node_put(n);
1678		__skb_queue_purge(list);
1679		return -EHOSTUNREACH;
1680	}
1681
1682	__skb_queue_head_init(&xmitq);
1683	le = &n->links[bearer_id];
1684	spin_lock_bh(&le->lock);
1685	rc = tipc_link_xmit(le->link, list, &xmitq);
1686	spin_unlock_bh(&le->lock);
1687	tipc_node_read_unlock(n);
1688
1689	if (unlikely(rc == -ENOBUFS))
1690		tipc_node_link_down(n, bearer_id, false);
1691	else
1692		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1693
1694	tipc_node_put(n);
1695
1696	return rc;
1697}
1698
1699/* tipc_node_xmit_skb(): send single buffer to destination
1700 * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1701 * messages, which will not be rejected
1702 * The only exception is datagram messages rerouted after secondary
1703 * lookup, which are rare and safe to dispose of anyway.
1704 */
1705int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1706		       u32 selector)
1707{
1708	struct sk_buff_head head;
1709
1710	__skb_queue_head_init(&head);
1711	__skb_queue_tail(&head, skb);
1712	tipc_node_xmit(net, &head, dnode, selector);
1713	return 0;
1714}
1715
1716/* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1717 * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1718 */
1719int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1720{
1721	struct sk_buff *skb;
1722	u32 selector, dnode;
1723
1724	while ((skb = __skb_dequeue(xmitq))) {
1725		selector = msg_origport(buf_msg(skb));
1726		dnode = msg_destnode(buf_msg(skb));
1727		tipc_node_xmit_skb(net, skb, dnode, selector);
1728	}
1729	return 0;
1730}
1731
1732void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1733{
1734	struct sk_buff *txskb;
1735	struct tipc_node *n;
1736	u32 dst;
1737
1738	rcu_read_lock();
1739	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1740		dst = n->addr;
1741		if (in_own_node(net, dst))
1742			continue;
1743		if (!node_is_up(n))
1744			continue;
1745		txskb = pskb_copy(skb, GFP_ATOMIC);
1746		if (!txskb)
1747			break;
1748		msg_set_destnode(buf_msg(txskb), dst);
1749		tipc_node_xmit_skb(net, txskb, dst, 0);
1750	}
1751	rcu_read_unlock();
1752
1753	kfree_skb(skb);
1754}
1755
1756static void tipc_node_mcast_rcv(struct tipc_node *n)
1757{
1758	struct tipc_bclink_entry *be = &n->bc_entry;
1759
1760	/* 'arrvq' is under inputq2's lock protection */
1761	spin_lock_bh(&be->inputq2.lock);
1762	spin_lock_bh(&be->inputq1.lock);
1763	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1764	spin_unlock_bh(&be->inputq1.lock);
1765	spin_unlock_bh(&be->inputq2.lock);
1766	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1767}
1768
1769static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1770				  int bearer_id, struct sk_buff_head *xmitq)
1771{
1772	struct tipc_link *ucl;
1773	int rc;
1774
1775	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1776
1777	if (rc & TIPC_LINK_DOWN_EVT) {
1778		tipc_node_reset_links(n);
1779		return;
1780	}
1781
1782	if (!(rc & TIPC_LINK_SND_STATE))
1783		return;
1784
1785	/* If probe message, a STATE response will be sent anyway */
1786	if (msg_probe(hdr))
1787		return;
1788
1789	/* Produce a STATE message carrying broadcast NACK */
1790	tipc_node_read_lock(n);
1791	ucl = n->links[bearer_id].link;
1792	if (ucl)
1793		tipc_link_build_state_msg(ucl, xmitq);
1794	tipc_node_read_unlock(n);
1795}
1796
1797/**
1798 * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1799 * @net: the applicable net namespace
1800 * @skb: TIPC packet
1801 * @bearer_id: id of bearer message arrived on
1802 *
1803 * Invoked with no locks held.
1804 */
1805static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1806{
1807	int rc;
1808	struct sk_buff_head xmitq;
1809	struct tipc_bclink_entry *be;
1810	struct tipc_link_entry *le;
1811	struct tipc_msg *hdr = buf_msg(skb);
1812	int usr = msg_user(hdr);
1813	u32 dnode = msg_destnode(hdr);
1814	struct tipc_node *n;
1815
1816	__skb_queue_head_init(&xmitq);
1817
1818	/* If NACK for other node, let rcv link for that node peek into it */
1819	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1820		n = tipc_node_find(net, dnode);
1821	else
1822		n = tipc_node_find(net, msg_prevnode(hdr));
1823	if (!n) {
1824		kfree_skb(skb);
1825		return;
1826	}
1827	be = &n->bc_entry;
1828	le = &n->links[bearer_id];
1829
1830	rc = tipc_bcast_rcv(net, be->link, skb);
1831
1832	/* Broadcast ACKs are sent on a unicast link */
1833	if (rc & TIPC_LINK_SND_STATE) {
1834		tipc_node_read_lock(n);
1835		tipc_link_build_state_msg(le->link, &xmitq);
1836		tipc_node_read_unlock(n);
1837	}
1838
1839	if (!skb_queue_empty(&xmitq))
1840		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1841
1842	if (!skb_queue_empty(&be->inputq1))
1843		tipc_node_mcast_rcv(n);
1844
1845	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1846	if (!skb_queue_empty(&n->bc_entry.namedq))
1847		tipc_named_rcv(net, &n->bc_entry.namedq);
1848
1849	/* If reassembly or retransmission failure => reset all links to peer */
1850	if (rc & TIPC_LINK_DOWN_EVT)
1851		tipc_node_reset_links(n);
1852
1853	tipc_node_put(n);
1854}
1855
1856/**
1857 * tipc_node_check_state - check and if necessary update node state
1858 * @skb: TIPC packet
1859 * @bearer_id: identity of bearer delivering the packet
1860 * Returns true if state and msg are ok, otherwise false
1861 */
1862static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1863				  int bearer_id, struct sk_buff_head *xmitq)
1864{
1865	struct tipc_msg *hdr = buf_msg(skb);
1866	int usr = msg_user(hdr);
1867	int mtyp = msg_type(hdr);
1868	u16 oseqno = msg_seqno(hdr);
1869	u16 exp_pkts = msg_msgcnt(hdr);
1870	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1871	int state = n->state;
1872	struct tipc_link *l, *tnl, *pl = NULL;
1873	struct tipc_media_addr *maddr;
1874	int pb_id;
1875
1876	if (trace_tipc_node_check_state_enabled()) {
1877		trace_tipc_skb_dump(skb, false, "skb for node state check");
1878		trace_tipc_node_check_state(n, true, " ");
1879	}
1880	l = n->links[bearer_id].link;
1881	if (!l)
1882		return false;
1883	rcv_nxt = tipc_link_rcv_nxt(l);
1884
1885
1886	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1887		return true;
1888
1889	/* Find parallel link, if any */
1890	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1891		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1892			pl = n->links[pb_id].link;
1893			break;
1894		}
1895	}
1896
1897	if (!tipc_link_validate_msg(l, hdr)

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