xref: /linux/net/tipc/node.c (revision 10a708c24a31ae1be1ea23d1c38da2691d1fd65c)
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 
48 #define INVALID_NODE_SIG	0x10000
49 #define NODE_CLEANUP_AFTER	300000
50 
51 /* Flags used to take different actions according to flag type
52  * TIPC_NOTIFY_NODE_DOWN: notify node is down
53  * TIPC_NOTIFY_NODE_UP: notify node is up
54  * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
55  */
56 enum {
57 	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
58 	TIPC_NOTIFY_NODE_UP		= (1 << 4),
59 	TIPC_NOTIFY_LINK_UP		= (1 << 6),
60 	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
61 };
62 
63 struct tipc_link_entry {
64 	struct tipc_link *link;
65 	spinlock_t lock; /* per link */
66 	u32 mtu;
67 	struct sk_buff_head inputq;
68 	struct tipc_media_addr maddr;
69 };
70 
71 struct tipc_bclink_entry {
72 	struct tipc_link *link;
73 	struct sk_buff_head inputq1;
74 	struct sk_buff_head arrvq;
75 	struct sk_buff_head inputq2;
76 	struct sk_buff_head namedq;
77 };
78 
79 /**
80  * struct tipc_node - TIPC node structure
81  * @addr: network address of node
82  * @ref: reference counter to node object
83  * @lock: rwlock governing access to structure
84  * @net: the applicable net namespace
85  * @hash: links to adjacent nodes in unsorted hash chain
86  * @inputq: pointer to input queue containing messages for msg event
87  * @namedq: pointer to name table input queue with name table messages
88  * @active_links: bearer ids of active links, used as index into links[] array
89  * @links: array containing references to all links to node
90  * @action_flags: bit mask of different types of node actions
91  * @state: connectivity state vs peer node
92  * @sync_point: sequence number where synch/failover is finished
93  * @list: links to adjacent nodes in sorted list of cluster's nodes
94  * @working_links: number of working links to node (both active and standby)
95  * @link_cnt: number of links to node
96  * @capabilities: bitmap, indicating peer node's functional capabilities
97  * @signature: node instance identifier
98  * @link_id: local and remote bearer ids of changing link, if any
99  * @publ_list: list of publications
100  * @rcu: rcu struct for tipc_node
101  * @delete_at: indicates the time for deleting a down node
102  */
103 struct tipc_node {
104 	u32 addr;
105 	struct kref kref;
106 	rwlock_t lock;
107 	struct net *net;
108 	struct hlist_node hash;
109 	int active_links[2];
110 	struct tipc_link_entry links[MAX_BEARERS];
111 	struct tipc_bclink_entry bc_entry;
112 	int action_flags;
113 	struct list_head list;
114 	int state;
115 	bool failover_sent;
116 	u16 sync_point;
117 	int link_cnt;
118 	u16 working_links;
119 	u16 capabilities;
120 	u32 signature;
121 	u32 link_id;
122 	u8 peer_id[16];
123 	struct list_head publ_list;
124 	struct list_head conn_sks;
125 	unsigned long keepalive_intv;
126 	struct timer_list timer;
127 	struct rcu_head rcu;
128 	unsigned long delete_at;
129 };
130 
131 /* Node FSM states and events:
132  */
133 enum {
134 	SELF_DOWN_PEER_DOWN    = 0xdd,
135 	SELF_UP_PEER_UP        = 0xaa,
136 	SELF_DOWN_PEER_LEAVING = 0xd1,
137 	SELF_UP_PEER_COMING    = 0xac,
138 	SELF_COMING_PEER_UP    = 0xca,
139 	SELF_LEAVING_PEER_DOWN = 0x1d,
140 	NODE_FAILINGOVER       = 0xf0,
141 	NODE_SYNCHING          = 0xcc
142 };
143 
144 enum {
145 	SELF_ESTABL_CONTACT_EVT = 0xece,
146 	SELF_LOST_CONTACT_EVT   = 0x1ce,
147 	PEER_ESTABL_CONTACT_EVT = 0x9ece,
148 	PEER_LOST_CONTACT_EVT   = 0x91ce,
149 	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
150 	NODE_FAILOVER_END_EVT   = 0xfee,
151 	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
152 	NODE_SYNCH_END_EVT      = 0xcee
153 };
154 
155 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
156 				  struct sk_buff_head *xmitq,
157 				  struct tipc_media_addr **maddr);
158 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
159 				bool delete);
160 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
161 static void tipc_node_delete(struct tipc_node *node);
162 static void tipc_node_timeout(struct timer_list *t);
163 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
164 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
165 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
166 static void tipc_node_put(struct tipc_node *node);
167 static bool node_is_up(struct tipc_node *n);
168 static void tipc_node_delete_from_list(struct tipc_node *node);
169 
170 struct tipc_sock_conn {
171 	u32 port;
172 	u32 peer_port;
173 	u32 peer_node;
174 	struct list_head list;
175 };
176 
177 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
178 {
179 	int bearer_id = n->active_links[sel & 1];
180 
181 	if (unlikely(bearer_id == INVALID_BEARER_ID))
182 		return NULL;
183 
184 	return n->links[bearer_id].link;
185 }
186 
187 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
188 {
189 	struct tipc_node *n;
190 	int bearer_id;
191 	unsigned int mtu = MAX_MSG_SIZE;
192 
193 	n = tipc_node_find(net, addr);
194 	if (unlikely(!n))
195 		return mtu;
196 
197 	bearer_id = n->active_links[sel & 1];
198 	if (likely(bearer_id != INVALID_BEARER_ID))
199 		mtu = n->links[bearer_id].mtu;
200 	tipc_node_put(n);
201 	return mtu;
202 }
203 
204 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
205 {
206 	u8 *own_id = tipc_own_id(net);
207 	struct tipc_node *n;
208 
209 	if (!own_id)
210 		return true;
211 
212 	if (addr == tipc_own_addr(net)) {
213 		memcpy(id, own_id, TIPC_NODEID_LEN);
214 		return true;
215 	}
216 	n = tipc_node_find(net, addr);
217 	if (!n)
218 		return false;
219 
220 	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
221 	tipc_node_put(n);
222 	return true;
223 }
224 
225 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
226 {
227 	struct tipc_node *n;
228 	u16 caps;
229 
230 	n = tipc_node_find(net, addr);
231 	if (unlikely(!n))
232 		return TIPC_NODE_CAPABILITIES;
233 	caps = n->capabilities;
234 	tipc_node_put(n);
235 	return caps;
236 }
237 
238 static void tipc_node_kref_release(struct kref *kref)
239 {
240 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
241 
242 	kfree(n->bc_entry.link);
243 	kfree_rcu(n, rcu);
244 }
245 
246 static void tipc_node_put(struct tipc_node *node)
247 {
248 	kref_put(&node->kref, tipc_node_kref_release);
249 }
250 
251 static void tipc_node_get(struct tipc_node *node)
252 {
253 	kref_get(&node->kref);
254 }
255 
256 /*
257  * tipc_node_find - locate specified node object, if it exists
258  */
259 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
260 {
261 	struct tipc_net *tn = tipc_net(net);
262 	struct tipc_node *node;
263 	unsigned int thash = tipc_hashfn(addr);
264 
265 	rcu_read_lock();
266 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
267 		if (node->addr != addr)
268 			continue;
269 		if (!kref_get_unless_zero(&node->kref))
270 			node = NULL;
271 		break;
272 	}
273 	rcu_read_unlock();
274 	return node;
275 }
276 
277 /* tipc_node_find_by_id - locate specified node object by its 128-bit id
278  * Note: this function is called only when a discovery request failed
279  * to find the node by its 32-bit id, and is not time critical
280  */
281 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
282 {
283 	struct tipc_net *tn = tipc_net(net);
284 	struct tipc_node *n;
285 	bool found = false;
286 
287 	rcu_read_lock();
288 	list_for_each_entry_rcu(n, &tn->node_list, list) {
289 		read_lock_bh(&n->lock);
290 		if (!memcmp(id, n->peer_id, 16) &&
291 		    kref_get_unless_zero(&n->kref))
292 			found = true;
293 		read_unlock_bh(&n->lock);
294 		if (found)
295 			break;
296 	}
297 	rcu_read_unlock();
298 	return found ? n : NULL;
299 }
300 
301 static void tipc_node_read_lock(struct tipc_node *n)
302 {
303 	read_lock_bh(&n->lock);
304 }
305 
306 static void tipc_node_read_unlock(struct tipc_node *n)
307 {
308 	read_unlock_bh(&n->lock);
309 }
310 
311 static void tipc_node_write_lock(struct tipc_node *n)
312 {
313 	write_lock_bh(&n->lock);
314 }
315 
316 static void tipc_node_write_unlock_fast(struct tipc_node *n)
317 {
318 	write_unlock_bh(&n->lock);
319 }
320 
321 static void tipc_node_write_unlock(struct tipc_node *n)
322 {
323 	struct net *net = n->net;
324 	u32 addr = 0;
325 	u32 flags = n->action_flags;
326 	u32 link_id = 0;
327 	u32 bearer_id;
328 	struct list_head *publ_list;
329 
330 	if (likely(!flags)) {
331 		write_unlock_bh(&n->lock);
332 		return;
333 	}
334 
335 	addr = n->addr;
336 	link_id = n->link_id;
337 	bearer_id = link_id & 0xffff;
338 	publ_list = &n->publ_list;
339 
340 	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
341 			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
342 
343 	write_unlock_bh(&n->lock);
344 
345 	if (flags & TIPC_NOTIFY_NODE_DOWN)
346 		tipc_publ_notify(net, publ_list, addr);
347 
348 	if (flags & TIPC_NOTIFY_NODE_UP)
349 		tipc_named_node_up(net, addr);
350 
351 	if (flags & TIPC_NOTIFY_LINK_UP) {
352 		tipc_mon_peer_up(net, addr, bearer_id);
353 		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
354 				     TIPC_NODE_SCOPE, link_id, link_id);
355 	}
356 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
357 		tipc_mon_peer_down(net, addr, bearer_id);
358 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
359 				      addr, link_id);
360 	}
361 }
362 
363 static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
364 					  u8 *peer_id, u16 capabilities)
365 {
366 	struct tipc_net *tn = net_generic(net, tipc_net_id);
367 	struct tipc_node *n, *temp_node;
368 	struct tipc_link *l;
369 	int bearer_id;
370 	int i;
371 
372 	spin_lock_bh(&tn->node_list_lock);
373 	n = tipc_node_find(net, addr);
374 	if (n) {
375 		if (n->capabilities == capabilities)
376 			goto exit;
377 		/* Same node may come back with new capabilities */
378 		tipc_node_write_lock(n);
379 		n->capabilities = capabilities;
380 		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
381 			l = n->links[bearer_id].link;
382 			if (l)
383 				tipc_link_update_caps(l, capabilities);
384 		}
385 		tipc_node_write_unlock_fast(n);
386 
387 		/* Calculate cluster capabilities */
388 		tn->capabilities = TIPC_NODE_CAPABILITIES;
389 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
390 			tn->capabilities &= temp_node->capabilities;
391 		}
392 		goto exit;
393 	}
394 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
395 	if (!n) {
396 		pr_warn("Node creation failed, no memory\n");
397 		goto exit;
398 	}
399 	n->addr = addr;
400 	memcpy(&n->peer_id, peer_id, 16);
401 	n->net = net;
402 	n->capabilities = capabilities;
403 	kref_init(&n->kref);
404 	rwlock_init(&n->lock);
405 	INIT_HLIST_NODE(&n->hash);
406 	INIT_LIST_HEAD(&n->list);
407 	INIT_LIST_HEAD(&n->publ_list);
408 	INIT_LIST_HEAD(&n->conn_sks);
409 	skb_queue_head_init(&n->bc_entry.namedq);
410 	skb_queue_head_init(&n->bc_entry.inputq1);
411 	__skb_queue_head_init(&n->bc_entry.arrvq);
412 	skb_queue_head_init(&n->bc_entry.inputq2);
413 	for (i = 0; i < MAX_BEARERS; i++)
414 		spin_lock_init(&n->links[i].lock);
415 	n->state = SELF_DOWN_PEER_LEAVING;
416 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
417 	n->signature = INVALID_NODE_SIG;
418 	n->active_links[0] = INVALID_BEARER_ID;
419 	n->active_links[1] = INVALID_BEARER_ID;
420 	if (!tipc_link_bc_create(net, tipc_own_addr(net),
421 				 addr, U16_MAX,
422 				 tipc_link_window(tipc_bc_sndlink(net)),
423 				 n->capabilities,
424 				 &n->bc_entry.inputq1,
425 				 &n->bc_entry.namedq,
426 				 tipc_bc_sndlink(net),
427 				 &n->bc_entry.link)) {
428 		pr_warn("Broadcast rcv link creation failed, no memory\n");
429 		kfree(n);
430 		n = NULL;
431 		goto exit;
432 	}
433 	tipc_node_get(n);
434 	timer_setup(&n->timer, tipc_node_timeout, 0);
435 	n->keepalive_intv = U32_MAX;
436 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
437 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
438 		if (n->addr < temp_node->addr)
439 			break;
440 	}
441 	list_add_tail_rcu(&n->list, &temp_node->list);
442 	/* Calculate cluster capabilities */
443 	tn->capabilities = TIPC_NODE_CAPABILITIES;
444 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
445 		tn->capabilities &= temp_node->capabilities;
446 	}
447 	trace_tipc_node_create(n, true, " ");
448 exit:
449 	spin_unlock_bh(&tn->node_list_lock);
450 	return n;
451 }
452 
453 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
454 {
455 	unsigned long tol = tipc_link_tolerance(l);
456 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
457 
458 	/* Link with lowest tolerance determines timer interval */
459 	if (intv < n->keepalive_intv)
460 		n->keepalive_intv = intv;
461 
462 	/* Ensure link's abort limit corresponds to current tolerance */
463 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
464 }
465 
466 static void tipc_node_delete_from_list(struct tipc_node *node)
467 {
468 	list_del_rcu(&node->list);
469 	hlist_del_rcu(&node->hash);
470 	tipc_node_put(node);
471 }
472 
473 static void tipc_node_delete(struct tipc_node *node)
474 {
475 	trace_tipc_node_delete(node, true, " ");
476 	tipc_node_delete_from_list(node);
477 
478 	del_timer_sync(&node->timer);
479 	tipc_node_put(node);
480 }
481 
482 void tipc_node_stop(struct net *net)
483 {
484 	struct tipc_net *tn = tipc_net(net);
485 	struct tipc_node *node, *t_node;
486 
487 	spin_lock_bh(&tn->node_list_lock);
488 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
489 		tipc_node_delete(node);
490 	spin_unlock_bh(&tn->node_list_lock);
491 }
492 
493 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
494 {
495 	struct tipc_node *n;
496 
497 	if (in_own_node(net, addr))
498 		return;
499 
500 	n = tipc_node_find(net, addr);
501 	if (!n) {
502 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
503 		return;
504 	}
505 	tipc_node_write_lock(n);
506 	list_add_tail(subscr, &n->publ_list);
507 	tipc_node_write_unlock_fast(n);
508 	tipc_node_put(n);
509 }
510 
511 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
512 {
513 	struct tipc_node *n;
514 
515 	if (in_own_node(net, addr))
516 		return;
517 
518 	n = tipc_node_find(net, addr);
519 	if (!n) {
520 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
521 		return;
522 	}
523 	tipc_node_write_lock(n);
524 	list_del_init(subscr);
525 	tipc_node_write_unlock_fast(n);
526 	tipc_node_put(n);
527 }
528 
529 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
530 {
531 	struct tipc_node *node;
532 	struct tipc_sock_conn *conn;
533 	int err = 0;
534 
535 	if (in_own_node(net, dnode))
536 		return 0;
537 
538 	node = tipc_node_find(net, dnode);
539 	if (!node) {
540 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
541 		return -EHOSTUNREACH;
542 	}
543 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
544 	if (!conn) {
545 		err = -EHOSTUNREACH;
546 		goto exit;
547 	}
548 	conn->peer_node = dnode;
549 	conn->port = port;
550 	conn->peer_port = peer_port;
551 
552 	tipc_node_write_lock(node);
553 	list_add_tail(&conn->list, &node->conn_sks);
554 	tipc_node_write_unlock(node);
555 exit:
556 	tipc_node_put(node);
557 	return err;
558 }
559 
560 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
561 {
562 	struct tipc_node *node;
563 	struct tipc_sock_conn *conn, *safe;
564 
565 	if (in_own_node(net, dnode))
566 		return;
567 
568 	node = tipc_node_find(net, dnode);
569 	if (!node)
570 		return;
571 
572 	tipc_node_write_lock(node);
573 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
574 		if (port != conn->port)
575 			continue;
576 		list_del(&conn->list);
577 		kfree(conn);
578 	}
579 	tipc_node_write_unlock(node);
580 	tipc_node_put(node);
581 }
582 
583 static void  tipc_node_clear_links(struct tipc_node *node)
584 {
585 	int i;
586 
587 	for (i = 0; i < MAX_BEARERS; i++) {
588 		struct tipc_link_entry *le = &node->links[i];
589 
590 		if (le->link) {
591 			kfree(le->link);
592 			le->link = NULL;
593 			node->link_cnt--;
594 		}
595 	}
596 }
597 
598 /* tipc_node_cleanup - delete nodes that does not
599  * have active links for NODE_CLEANUP_AFTER time
600  */
601 static bool tipc_node_cleanup(struct tipc_node *peer)
602 {
603 	struct tipc_node *temp_node;
604 	struct tipc_net *tn = tipc_net(peer->net);
605 	bool deleted = false;
606 
607 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
608 	if (!spin_trylock_bh(&tn->node_list_lock))
609 		return false;
610 
611 	tipc_node_write_lock(peer);
612 
613 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
614 		tipc_node_clear_links(peer);
615 		tipc_node_delete_from_list(peer);
616 		deleted = true;
617 	}
618 	tipc_node_write_unlock(peer);
619 
620 	/* Calculate cluster capabilities */
621 	tn->capabilities = TIPC_NODE_CAPABILITIES;
622 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
623 		tn->capabilities &= temp_node->capabilities;
624 	}
625 
626 	spin_unlock_bh(&tn->node_list_lock);
627 	return deleted;
628 }
629 
630 /* tipc_node_timeout - handle expiration of node timer
631  */
632 static void tipc_node_timeout(struct timer_list *t)
633 {
634 	struct tipc_node *n = from_timer(n, t, timer);
635 	struct tipc_link_entry *le;
636 	struct sk_buff_head xmitq;
637 	int remains = n->link_cnt;
638 	int bearer_id;
639 	int rc = 0;
640 
641 	trace_tipc_node_timeout(n, false, " ");
642 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
643 		/*Removing the reference of Timer*/
644 		tipc_node_put(n);
645 		return;
646 	}
647 
648 	__skb_queue_head_init(&xmitq);
649 
650 	/* Initial node interval to value larger (10 seconds), then it will be
651 	 * recalculated with link lowest tolerance
652 	 */
653 	tipc_node_read_lock(n);
654 	n->keepalive_intv = 10000;
655 	tipc_node_read_unlock(n);
656 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
657 		tipc_node_read_lock(n);
658 		le = &n->links[bearer_id];
659 		if (le->link) {
660 			spin_lock_bh(&le->lock);
661 			/* Link tolerance may change asynchronously: */
662 			tipc_node_calculate_timer(n, le->link);
663 			rc = tipc_link_timeout(le->link, &xmitq);
664 			spin_unlock_bh(&le->lock);
665 			remains--;
666 		}
667 		tipc_node_read_unlock(n);
668 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
669 		if (rc & TIPC_LINK_DOWN_EVT)
670 			tipc_node_link_down(n, bearer_id, false);
671 	}
672 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
673 }
674 
675 /**
676  * __tipc_node_link_up - handle addition of link
677  * Node lock must be held by caller
678  * Link becomes active (alone or shared) or standby, depending on its priority.
679  */
680 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
681 				struct sk_buff_head *xmitq)
682 {
683 	int *slot0 = &n->active_links[0];
684 	int *slot1 = &n->active_links[1];
685 	struct tipc_link *ol = node_active_link(n, 0);
686 	struct tipc_link *nl = n->links[bearer_id].link;
687 
688 	if (!nl || tipc_link_is_up(nl))
689 		return;
690 
691 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
692 	if (!tipc_link_is_up(nl))
693 		return;
694 
695 	n->working_links++;
696 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
697 	n->link_id = tipc_link_id(nl);
698 
699 	/* Leave room for tunnel header when returning 'mtu' to users: */
700 	n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
701 
702 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
703 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
704 
705 	pr_debug("Established link <%s> on network plane %c\n",
706 		 tipc_link_name(nl), tipc_link_plane(nl));
707 	trace_tipc_node_link_up(n, true, " ");
708 
709 	/* Ensure that a STATE message goes first */
710 	tipc_link_build_state_msg(nl, xmitq);
711 
712 	/* First link? => give it both slots */
713 	if (!ol) {
714 		*slot0 = bearer_id;
715 		*slot1 = bearer_id;
716 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
717 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
718 		tipc_link_set_active(nl, true);
719 		tipc_bcast_add_peer(n->net, nl, xmitq);
720 		return;
721 	}
722 
723 	/* Second link => redistribute slots */
724 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
725 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
726 		*slot0 = bearer_id;
727 		*slot1 = bearer_id;
728 		tipc_link_set_active(nl, true);
729 		tipc_link_set_active(ol, false);
730 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
731 		tipc_link_set_active(nl, true);
732 		*slot1 = bearer_id;
733 	} else {
734 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
735 	}
736 
737 	/* Prepare synchronization with first link */
738 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
739 }
740 
741 /**
742  * tipc_node_link_up - handle addition of link
743  *
744  * Link becomes active (alone or shared) or standby, depending on its priority.
745  */
746 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
747 			      struct sk_buff_head *xmitq)
748 {
749 	struct tipc_media_addr *maddr;
750 
751 	tipc_node_write_lock(n);
752 	__tipc_node_link_up(n, bearer_id, xmitq);
753 	maddr = &n->links[bearer_id].maddr;
754 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
755 	tipc_node_write_unlock(n);
756 }
757 
758 /**
759  * tipc_node_link_failover() - start failover in case "half-failover"
760  *
761  * This function is only called in a very special situation where link
762  * failover can be already started on peer node but not on this node.
763  * This can happen when e.g.
764  *	1. Both links <1A-2A>, <1B-2B> down
765  *	2. Link endpoint 2A up, but 1A still down (e.g. due to network
766  *	   disturbance, wrong session, etc.)
767  *	3. Link <1B-2B> up
768  *	4. Link endpoint 2A down (e.g. due to link tolerance timeout)
769  *	5. Node 2 starts failover onto link <1B-2B>
770  *
771  *	==> Node 1 does never start link/node failover!
772  *
773  * @n: tipc node structure
774  * @l: link peer endpoint failingover (- can be NULL)
775  * @tnl: tunnel link
776  * @xmitq: queue for messages to be xmited on tnl link later
777  */
778 static void tipc_node_link_failover(struct tipc_node *n, struct tipc_link *l,
779 				    struct tipc_link *tnl,
780 				    struct sk_buff_head *xmitq)
781 {
782 	/* Avoid to be "self-failover" that can never end */
783 	if (!tipc_link_is_up(tnl))
784 		return;
785 
786 	/* Don't rush, failure link may be in the process of resetting */
787 	if (l && !tipc_link_is_reset(l))
788 		return;
789 
790 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
791 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
792 
793 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
794 	tipc_link_failover_prepare(l, tnl, xmitq);
795 
796 	if (l)
797 		tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
798 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
799 }
800 
801 /**
802  * __tipc_node_link_down - handle loss of link
803  */
804 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
805 				  struct sk_buff_head *xmitq,
806 				  struct tipc_media_addr **maddr)
807 {
808 	struct tipc_link_entry *le = &n->links[*bearer_id];
809 	int *slot0 = &n->active_links[0];
810 	int *slot1 = &n->active_links[1];
811 	int i, highest = 0, prio;
812 	struct tipc_link *l, *_l, *tnl;
813 
814 	l = n->links[*bearer_id].link;
815 	if (!l || tipc_link_is_reset(l))
816 		return;
817 
818 	n->working_links--;
819 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
820 	n->link_id = tipc_link_id(l);
821 
822 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
823 
824 	pr_debug("Lost link <%s> on network plane %c\n",
825 		 tipc_link_name(l), tipc_link_plane(l));
826 
827 	/* Select new active link if any available */
828 	*slot0 = INVALID_BEARER_ID;
829 	*slot1 = INVALID_BEARER_ID;
830 	for (i = 0; i < MAX_BEARERS; i++) {
831 		_l = n->links[i].link;
832 		if (!_l || !tipc_link_is_up(_l))
833 			continue;
834 		if (_l == l)
835 			continue;
836 		prio = tipc_link_prio(_l);
837 		if (prio < highest)
838 			continue;
839 		if (prio > highest) {
840 			highest = prio;
841 			*slot0 = i;
842 			*slot1 = i;
843 			continue;
844 		}
845 		*slot1 = i;
846 	}
847 
848 	if (!node_is_up(n)) {
849 		if (tipc_link_peer_is_down(l))
850 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
851 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
852 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
853 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
854 		tipc_link_reset(l);
855 		tipc_link_build_reset_msg(l, xmitq);
856 		*maddr = &n->links[*bearer_id].maddr;
857 		node_lost_contact(n, &le->inputq);
858 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
859 		return;
860 	}
861 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
862 
863 	/* There is still a working link => initiate failover */
864 	*bearer_id = n->active_links[0];
865 	tnl = n->links[*bearer_id].link;
866 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
867 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
868 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
869 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
870 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
871 	tipc_link_reset(l);
872 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
873 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
874 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
875 	*maddr = &n->links[*bearer_id].maddr;
876 }
877 
878 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
879 {
880 	struct tipc_link_entry *le = &n->links[bearer_id];
881 	struct tipc_media_addr *maddr = NULL;
882 	struct tipc_link *l = le->link;
883 	int old_bearer_id = bearer_id;
884 	struct sk_buff_head xmitq;
885 
886 	if (!l)
887 		return;
888 
889 	__skb_queue_head_init(&xmitq);
890 
891 	tipc_node_write_lock(n);
892 	if (!tipc_link_is_establishing(l)) {
893 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
894 	} else {
895 		/* Defuse pending tipc_node_link_up() */
896 		tipc_link_reset(l);
897 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
898 	}
899 	if (delete) {
900 		kfree(l);
901 		le->link = NULL;
902 		n->link_cnt--;
903 	}
904 	trace_tipc_node_link_down(n, true, "node link down or deleted!");
905 	tipc_node_write_unlock(n);
906 	if (delete)
907 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
908 	if (!skb_queue_empty(&xmitq))
909 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
910 	tipc_sk_rcv(n->net, &le->inputq);
911 }
912 
913 static bool node_is_up(struct tipc_node *n)
914 {
915 	return n->active_links[0] != INVALID_BEARER_ID;
916 }
917 
918 bool tipc_node_is_up(struct net *net, u32 addr)
919 {
920 	struct tipc_node *n;
921 	bool retval = false;
922 
923 	if (in_own_node(net, addr))
924 		return true;
925 
926 	n = tipc_node_find(net, addr);
927 	if (!n)
928 		return false;
929 	retval = node_is_up(n);
930 	tipc_node_put(n);
931 	return retval;
932 }
933 
934 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
935 {
936 	struct tipc_node *n;
937 
938 	addr ^= tipc_net(net)->random;
939 	while ((n = tipc_node_find(net, addr))) {
940 		tipc_node_put(n);
941 		addr++;
942 	}
943 	return addr;
944 }
945 
946 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
947  * Returns suggested address if any, otherwise 0
948  */
949 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
950 {
951 	struct tipc_net *tn = tipc_net(net);
952 	struct tipc_node *n;
953 
954 	/* Suggest new address if some other peer is using this one */
955 	n = tipc_node_find(net, addr);
956 	if (n) {
957 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
958 			addr = 0;
959 		tipc_node_put(n);
960 		if (!addr)
961 			return 0;
962 		return tipc_node_suggest_addr(net, addr);
963 	}
964 
965 	/* Suggest previously used address if peer is known */
966 	n = tipc_node_find_by_id(net, id);
967 	if (n) {
968 		addr = n->addr;
969 		tipc_node_put(n);
970 		return addr;
971 	}
972 
973 	/* Even this node may be in conflict */
974 	if (tn->trial_addr == addr)
975 		return tipc_node_suggest_addr(net, addr);
976 
977 	return 0;
978 }
979 
980 void tipc_node_check_dest(struct net *net, u32 addr,
981 			  u8 *peer_id, struct tipc_bearer *b,
982 			  u16 capabilities, u32 signature,
983 			  struct tipc_media_addr *maddr,
984 			  bool *respond, bool *dupl_addr)
985 {
986 	struct tipc_node *n;
987 	struct tipc_link *l;
988 	struct tipc_link_entry *le;
989 	bool addr_match = false;
990 	bool sign_match = false;
991 	bool link_up = false;
992 	bool accept_addr = false;
993 	bool reset = true;
994 	char *if_name;
995 	unsigned long intv;
996 	u16 session;
997 
998 	*dupl_addr = false;
999 	*respond = false;
1000 
1001 	n = tipc_node_create(net, addr, peer_id, capabilities);
1002 	if (!n)
1003 		return;
1004 
1005 	tipc_node_write_lock(n);
1006 
1007 	le = &n->links[b->identity];
1008 
1009 	/* Prepare to validate requesting node's signature and media address */
1010 	l = le->link;
1011 	link_up = l && tipc_link_is_up(l);
1012 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1013 	sign_match = (signature == n->signature);
1014 
1015 	/* These three flags give us eight permutations: */
1016 
1017 	if (sign_match && addr_match && link_up) {
1018 		/* All is fine. Do nothing. */
1019 		reset = false;
1020 	} else if (sign_match && addr_match && !link_up) {
1021 		/* Respond. The link will come up in due time */
1022 		*respond = true;
1023 	} else if (sign_match && !addr_match && link_up) {
1024 		/* Peer has changed i/f address without rebooting.
1025 		 * If so, the link will reset soon, and the next
1026 		 * discovery will be accepted. So we can ignore it.
1027 		 * It may also be an cloned or malicious peer having
1028 		 * chosen the same node address and signature as an
1029 		 * existing one.
1030 		 * Ignore requests until the link goes down, if ever.
1031 		 */
1032 		*dupl_addr = true;
1033 	} else if (sign_match && !addr_match && !link_up) {
1034 		/* Peer link has changed i/f address without rebooting.
1035 		 * It may also be a cloned or malicious peer; we can't
1036 		 * distinguish between the two.
1037 		 * The signature is correct, so we must accept.
1038 		 */
1039 		accept_addr = true;
1040 		*respond = true;
1041 	} else if (!sign_match && addr_match && link_up) {
1042 		/* Peer node rebooted. Two possibilities:
1043 		 *  - Delayed re-discovery; this link endpoint has already
1044 		 *    reset and re-established contact with the peer, before
1045 		 *    receiving a discovery message from that node.
1046 		 *    (The peer happened to receive one from this node first).
1047 		 *  - The peer came back so fast that our side has not
1048 		 *    discovered it yet. Probing from this side will soon
1049 		 *    reset the link, since there can be no working link
1050 		 *    endpoint at the peer end, and the link will re-establish.
1051 		 *  Accept the signature, since it comes from a known peer.
1052 		 */
1053 		n->signature = signature;
1054 	} else if (!sign_match && addr_match && !link_up) {
1055 		/*  The peer node has rebooted.
1056 		 *  Accept signature, since it is a known peer.
1057 		 */
1058 		n->signature = signature;
1059 		*respond = true;
1060 	} else if (!sign_match && !addr_match && link_up) {
1061 		/* Peer rebooted with new address, or a new/duplicate peer.
1062 		 * Ignore until the link goes down, if ever.
1063 		 */
1064 		*dupl_addr = true;
1065 	} else if (!sign_match && !addr_match && !link_up) {
1066 		/* Peer rebooted with new address, or it is a new peer.
1067 		 * Accept signature and address.
1068 		 */
1069 		n->signature = signature;
1070 		accept_addr = true;
1071 		*respond = true;
1072 	}
1073 
1074 	if (!accept_addr)
1075 		goto exit;
1076 
1077 	/* Now create new link if not already existing */
1078 	if (!l) {
1079 		if (n->link_cnt == 2)
1080 			goto exit;
1081 
1082 		if_name = strchr(b->name, ':') + 1;
1083 		get_random_bytes(&session, sizeof(u16));
1084 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1085 				      b->net_plane, b->mtu, b->priority,
1086 				      b->window, session,
1087 				      tipc_own_addr(net), addr, peer_id,
1088 				      n->capabilities,
1089 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1090 				      &le->inputq,
1091 				      &n->bc_entry.namedq, &l)) {
1092 			*respond = false;
1093 			goto exit;
1094 		}
1095 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1096 		tipc_link_reset(l);
1097 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1098 		if (n->state == NODE_FAILINGOVER)
1099 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1100 		le->link = l;
1101 		n->link_cnt++;
1102 		tipc_node_calculate_timer(n, l);
1103 		if (n->link_cnt == 1) {
1104 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1105 			if (!mod_timer(&n->timer, intv))
1106 				tipc_node_get(n);
1107 		}
1108 	}
1109 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1110 exit:
1111 	tipc_node_write_unlock(n);
1112 	if (reset && l && !tipc_link_is_reset(l))
1113 		tipc_node_link_down(n, b->identity, false);
1114 	tipc_node_put(n);
1115 }
1116 
1117 void tipc_node_delete_links(struct net *net, int bearer_id)
1118 {
1119 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1120 	struct tipc_node *n;
1121 
1122 	rcu_read_lock();
1123 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1124 		tipc_node_link_down(n, bearer_id, true);
1125 	}
1126 	rcu_read_unlock();
1127 }
1128 
1129 static void tipc_node_reset_links(struct tipc_node *n)
1130 {
1131 	int i;
1132 
1133 	pr_warn("Resetting all links to %x\n", n->addr);
1134 
1135 	trace_tipc_node_reset_links(n, true, " ");
1136 	for (i = 0; i < MAX_BEARERS; i++) {
1137 		tipc_node_link_down(n, i, false);
1138 	}
1139 }
1140 
1141 /* tipc_node_fsm_evt - node finite state machine
1142  * Determines when contact is allowed with peer node
1143  */
1144 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1145 {
1146 	int state = n->state;
1147 
1148 	switch (state) {
1149 	case SELF_DOWN_PEER_DOWN:
1150 		switch (evt) {
1151 		case SELF_ESTABL_CONTACT_EVT:
1152 			state = SELF_UP_PEER_COMING;
1153 			break;
1154 		case PEER_ESTABL_CONTACT_EVT:
1155 			state = SELF_COMING_PEER_UP;
1156 			break;
1157 		case SELF_LOST_CONTACT_EVT:
1158 		case PEER_LOST_CONTACT_EVT:
1159 			break;
1160 		case NODE_SYNCH_END_EVT:
1161 		case NODE_SYNCH_BEGIN_EVT:
1162 		case NODE_FAILOVER_BEGIN_EVT:
1163 		case NODE_FAILOVER_END_EVT:
1164 		default:
1165 			goto illegal_evt;
1166 		}
1167 		break;
1168 	case SELF_UP_PEER_UP:
1169 		switch (evt) {
1170 		case SELF_LOST_CONTACT_EVT:
1171 			state = SELF_DOWN_PEER_LEAVING;
1172 			break;
1173 		case PEER_LOST_CONTACT_EVT:
1174 			state = SELF_LEAVING_PEER_DOWN;
1175 			break;
1176 		case NODE_SYNCH_BEGIN_EVT:
1177 			state = NODE_SYNCHING;
1178 			break;
1179 		case NODE_FAILOVER_BEGIN_EVT:
1180 			state = NODE_FAILINGOVER;
1181 			break;
1182 		case SELF_ESTABL_CONTACT_EVT:
1183 		case PEER_ESTABL_CONTACT_EVT:
1184 		case NODE_SYNCH_END_EVT:
1185 		case NODE_FAILOVER_END_EVT:
1186 			break;
1187 		default:
1188 			goto illegal_evt;
1189 		}
1190 		break;
1191 	case SELF_DOWN_PEER_LEAVING:
1192 		switch (evt) {
1193 		case PEER_LOST_CONTACT_EVT:
1194 			state = SELF_DOWN_PEER_DOWN;
1195 			break;
1196 		case SELF_ESTABL_CONTACT_EVT:
1197 		case PEER_ESTABL_CONTACT_EVT:
1198 		case SELF_LOST_CONTACT_EVT:
1199 			break;
1200 		case NODE_SYNCH_END_EVT:
1201 		case NODE_SYNCH_BEGIN_EVT:
1202 		case NODE_FAILOVER_BEGIN_EVT:
1203 		case NODE_FAILOVER_END_EVT:
1204 		default:
1205 			goto illegal_evt;
1206 		}
1207 		break;
1208 	case SELF_UP_PEER_COMING:
1209 		switch (evt) {
1210 		case PEER_ESTABL_CONTACT_EVT:
1211 			state = SELF_UP_PEER_UP;
1212 			break;
1213 		case SELF_LOST_CONTACT_EVT:
1214 			state = SELF_DOWN_PEER_DOWN;
1215 			break;
1216 		case SELF_ESTABL_CONTACT_EVT:
1217 		case PEER_LOST_CONTACT_EVT:
1218 		case NODE_SYNCH_END_EVT:
1219 		case NODE_FAILOVER_BEGIN_EVT:
1220 			break;
1221 		case NODE_SYNCH_BEGIN_EVT:
1222 		case NODE_FAILOVER_END_EVT:
1223 		default:
1224 			goto illegal_evt;
1225 		}
1226 		break;
1227 	case SELF_COMING_PEER_UP:
1228 		switch (evt) {
1229 		case SELF_ESTABL_CONTACT_EVT:
1230 			state = SELF_UP_PEER_UP;
1231 			break;
1232 		case PEER_LOST_CONTACT_EVT:
1233 			state = SELF_DOWN_PEER_DOWN;
1234 			break;
1235 		case SELF_LOST_CONTACT_EVT:
1236 		case PEER_ESTABL_CONTACT_EVT:
1237 			break;
1238 		case NODE_SYNCH_END_EVT:
1239 		case NODE_SYNCH_BEGIN_EVT:
1240 		case NODE_FAILOVER_BEGIN_EVT:
1241 		case NODE_FAILOVER_END_EVT:
1242 		default:
1243 			goto illegal_evt;
1244 		}
1245 		break;
1246 	case SELF_LEAVING_PEER_DOWN:
1247 		switch (evt) {
1248 		case SELF_LOST_CONTACT_EVT:
1249 			state = SELF_DOWN_PEER_DOWN;
1250 			break;
1251 		case SELF_ESTABL_CONTACT_EVT:
1252 		case PEER_ESTABL_CONTACT_EVT:
1253 		case PEER_LOST_CONTACT_EVT:
1254 			break;
1255 		case NODE_SYNCH_END_EVT:
1256 		case NODE_SYNCH_BEGIN_EVT:
1257 		case NODE_FAILOVER_BEGIN_EVT:
1258 		case NODE_FAILOVER_END_EVT:
1259 		default:
1260 			goto illegal_evt;
1261 		}
1262 		break;
1263 	case NODE_FAILINGOVER:
1264 		switch (evt) {
1265 		case SELF_LOST_CONTACT_EVT:
1266 			state = SELF_DOWN_PEER_LEAVING;
1267 			break;
1268 		case PEER_LOST_CONTACT_EVT:
1269 			state = SELF_LEAVING_PEER_DOWN;
1270 			break;
1271 		case NODE_FAILOVER_END_EVT:
1272 			state = SELF_UP_PEER_UP;
1273 			break;
1274 		case NODE_FAILOVER_BEGIN_EVT:
1275 		case SELF_ESTABL_CONTACT_EVT:
1276 		case PEER_ESTABL_CONTACT_EVT:
1277 			break;
1278 		case NODE_SYNCH_BEGIN_EVT:
1279 		case NODE_SYNCH_END_EVT:
1280 		default:
1281 			goto illegal_evt;
1282 		}
1283 		break;
1284 	case NODE_SYNCHING:
1285 		switch (evt) {
1286 		case SELF_LOST_CONTACT_EVT:
1287 			state = SELF_DOWN_PEER_LEAVING;
1288 			break;
1289 		case PEER_LOST_CONTACT_EVT:
1290 			state = SELF_LEAVING_PEER_DOWN;
1291 			break;
1292 		case NODE_SYNCH_END_EVT:
1293 			state = SELF_UP_PEER_UP;
1294 			break;
1295 		case NODE_FAILOVER_BEGIN_EVT:
1296 			state = NODE_FAILINGOVER;
1297 			break;
1298 		case NODE_SYNCH_BEGIN_EVT:
1299 		case SELF_ESTABL_CONTACT_EVT:
1300 		case PEER_ESTABL_CONTACT_EVT:
1301 			break;
1302 		case NODE_FAILOVER_END_EVT:
1303 		default:
1304 			goto illegal_evt;
1305 		}
1306 		break;
1307 	default:
1308 		pr_err("Unknown node fsm state %x\n", state);
1309 		break;
1310 	}
1311 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1312 	n->state = state;
1313 	return;
1314 
1315 illegal_evt:
1316 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1317 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1318 }
1319 
1320 static void node_lost_contact(struct tipc_node *n,
1321 			      struct sk_buff_head *inputq)
1322 {
1323 	struct tipc_sock_conn *conn, *safe;
1324 	struct tipc_link *l;
1325 	struct list_head *conns = &n->conn_sks;
1326 	struct sk_buff *skb;
1327 	uint i;
1328 
1329 	pr_debug("Lost contact with %x\n", n->addr);
1330 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1331 	trace_tipc_node_lost_contact(n, true, " ");
1332 
1333 	/* Clean up broadcast state */
1334 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1335 
1336 	/* Abort any ongoing link failover */
1337 	for (i = 0; i < MAX_BEARERS; i++) {
1338 		l = n->links[i].link;
1339 		if (l)
1340 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1341 	}
1342 
1343 	/* Notify publications from this node */
1344 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1345 
1346 	/* Notify sockets connected to node */
1347 	list_for_each_entry_safe(conn, safe, conns, list) {
1348 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1349 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1350 				      conn->peer_node, conn->port,
1351 				      conn->peer_port, TIPC_ERR_NO_NODE);
1352 		if (likely(skb))
1353 			skb_queue_tail(inputq, skb);
1354 		list_del(&conn->list);
1355 		kfree(conn);
1356 	}
1357 }
1358 
1359 /**
1360  * tipc_node_get_linkname - get the name of a link
1361  *
1362  * @bearer_id: id of the bearer
1363  * @node: peer node address
1364  * @linkname: link name output buffer
1365  *
1366  * Returns 0 on success
1367  */
1368 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1369 			   char *linkname, size_t len)
1370 {
1371 	struct tipc_link *link;
1372 	int err = -EINVAL;
1373 	struct tipc_node *node = tipc_node_find(net, addr);
1374 
1375 	if (!node)
1376 		return err;
1377 
1378 	if (bearer_id >= MAX_BEARERS)
1379 		goto exit;
1380 
1381 	tipc_node_read_lock(node);
1382 	link = node->links[bearer_id].link;
1383 	if (link) {
1384 		strncpy(linkname, tipc_link_name(link), len);
1385 		err = 0;
1386 	}
1387 	tipc_node_read_unlock(node);
1388 exit:
1389 	tipc_node_put(node);
1390 	return err;
1391 }
1392 
1393 /* Caller should hold node lock for the passed node */
1394 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1395 {
1396 	void *hdr;
1397 	struct nlattr *attrs;
1398 
1399 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1400 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1401 	if (!hdr)
1402 		return -EMSGSIZE;
1403 
1404 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1405 	if (!attrs)
1406 		goto msg_full;
1407 
1408 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1409 		goto attr_msg_full;
1410 	if (node_is_up(node))
1411 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1412 			goto attr_msg_full;
1413 
1414 	nla_nest_end(msg->skb, attrs);
1415 	genlmsg_end(msg->skb, hdr);
1416 
1417 	return 0;
1418 
1419 attr_msg_full:
1420 	nla_nest_cancel(msg->skb, attrs);
1421 msg_full:
1422 	genlmsg_cancel(msg->skb, hdr);
1423 
1424 	return -EMSGSIZE;
1425 }
1426 
1427 /**
1428  * tipc_node_xmit() is the general link level function for message sending
1429  * @net: the applicable net namespace
1430  * @list: chain of buffers containing message
1431  * @dnode: address of destination node
1432  * @selector: a number used for deterministic link selection
1433  * Consumes the buffer chain.
1434  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1435  */
1436 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1437 		   u32 dnode, int selector)
1438 {
1439 	struct tipc_link_entry *le = NULL;
1440 	struct tipc_node *n;
1441 	struct sk_buff_head xmitq;
1442 	int bearer_id;
1443 	int rc;
1444 
1445 	if (in_own_node(net, dnode)) {
1446 		tipc_loopback_trace(net, list);
1447 		tipc_sk_rcv(net, list);
1448 		return 0;
1449 	}
1450 
1451 	n = tipc_node_find(net, dnode);
1452 	if (unlikely(!n)) {
1453 		skb_queue_purge(list);
1454 		return -EHOSTUNREACH;
1455 	}
1456 
1457 	tipc_node_read_lock(n);
1458 	bearer_id = n->active_links[selector & 1];
1459 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1460 		tipc_node_read_unlock(n);
1461 		tipc_node_put(n);
1462 		skb_queue_purge(list);
1463 		return -EHOSTUNREACH;
1464 	}
1465 
1466 	__skb_queue_head_init(&xmitq);
1467 	le = &n->links[bearer_id];
1468 	spin_lock_bh(&le->lock);
1469 	rc = tipc_link_xmit(le->link, list, &xmitq);
1470 	spin_unlock_bh(&le->lock);
1471 	tipc_node_read_unlock(n);
1472 
1473 	if (unlikely(rc == -ENOBUFS))
1474 		tipc_node_link_down(n, bearer_id, false);
1475 	else
1476 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1477 
1478 	tipc_node_put(n);
1479 
1480 	return rc;
1481 }
1482 
1483 /* tipc_node_xmit_skb(): send single buffer to destination
1484  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1485  * messages, which will not be rejected
1486  * The only exception is datagram messages rerouted after secondary
1487  * lookup, which are rare and safe to dispose of anyway.
1488  */
1489 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1490 		       u32 selector)
1491 {
1492 	struct sk_buff_head head;
1493 
1494 	skb_queue_head_init(&head);
1495 	__skb_queue_tail(&head, skb);
1496 	tipc_node_xmit(net, &head, dnode, selector);
1497 	return 0;
1498 }
1499 
1500 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1501  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1502  */
1503 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1504 {
1505 	struct sk_buff *skb;
1506 	u32 selector, dnode;
1507 
1508 	while ((skb = __skb_dequeue(xmitq))) {
1509 		selector = msg_origport(buf_msg(skb));
1510 		dnode = msg_destnode(buf_msg(skb));
1511 		tipc_node_xmit_skb(net, skb, dnode, selector);
1512 	}
1513 	return 0;
1514 }
1515 
1516 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1517 {
1518 	struct sk_buff *txskb;
1519 	struct tipc_node *n;
1520 	u32 dst;
1521 
1522 	rcu_read_lock();
1523 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1524 		dst = n->addr;
1525 		if (in_own_node(net, dst))
1526 			continue;
1527 		if (!node_is_up(n))
1528 			continue;
1529 		txskb = pskb_copy(skb, GFP_ATOMIC);
1530 		if (!txskb)
1531 			break;
1532 		msg_set_destnode(buf_msg(txskb), dst);
1533 		tipc_node_xmit_skb(net, txskb, dst, 0);
1534 	}
1535 	rcu_read_unlock();
1536 
1537 	kfree_skb(skb);
1538 }
1539 
1540 static void tipc_node_mcast_rcv(struct tipc_node *n)
1541 {
1542 	struct tipc_bclink_entry *be = &n->bc_entry;
1543 
1544 	/* 'arrvq' is under inputq2's lock protection */
1545 	spin_lock_bh(&be->inputq2.lock);
1546 	spin_lock_bh(&be->inputq1.lock);
1547 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1548 	spin_unlock_bh(&be->inputq1.lock);
1549 	spin_unlock_bh(&be->inputq2.lock);
1550 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1551 }
1552 
1553 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1554 				  int bearer_id, struct sk_buff_head *xmitq)
1555 {
1556 	struct tipc_link *ucl;
1557 	int rc;
1558 
1559 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1560 
1561 	if (rc & TIPC_LINK_DOWN_EVT) {
1562 		tipc_node_reset_links(n);
1563 		return;
1564 	}
1565 
1566 	if (!(rc & TIPC_LINK_SND_STATE))
1567 		return;
1568 
1569 	/* If probe message, a STATE response will be sent anyway */
1570 	if (msg_probe(hdr))
1571 		return;
1572 
1573 	/* Produce a STATE message carrying broadcast NACK */
1574 	tipc_node_read_lock(n);
1575 	ucl = n->links[bearer_id].link;
1576 	if (ucl)
1577 		tipc_link_build_state_msg(ucl, xmitq);
1578 	tipc_node_read_unlock(n);
1579 }
1580 
1581 /**
1582  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1583  * @net: the applicable net namespace
1584  * @skb: TIPC packet
1585  * @bearer_id: id of bearer message arrived on
1586  *
1587  * Invoked with no locks held.
1588  */
1589 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1590 {
1591 	int rc;
1592 	struct sk_buff_head xmitq;
1593 	struct tipc_bclink_entry *be;
1594 	struct tipc_link_entry *le;
1595 	struct tipc_msg *hdr = buf_msg(skb);
1596 	int usr = msg_user(hdr);
1597 	u32 dnode = msg_destnode(hdr);
1598 	struct tipc_node *n;
1599 
1600 	__skb_queue_head_init(&xmitq);
1601 
1602 	/* If NACK for other node, let rcv link for that node peek into it */
1603 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1604 		n = tipc_node_find(net, dnode);
1605 	else
1606 		n = tipc_node_find(net, msg_prevnode(hdr));
1607 	if (!n) {
1608 		kfree_skb(skb);
1609 		return;
1610 	}
1611 	be = &n->bc_entry;
1612 	le = &n->links[bearer_id];
1613 
1614 	rc = tipc_bcast_rcv(net, be->link, skb);
1615 
1616 	/* Broadcast ACKs are sent on a unicast link */
1617 	if (rc & TIPC_LINK_SND_STATE) {
1618 		tipc_node_read_lock(n);
1619 		tipc_link_build_state_msg(le->link, &xmitq);
1620 		tipc_node_read_unlock(n);
1621 	}
1622 
1623 	if (!skb_queue_empty(&xmitq))
1624 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1625 
1626 	if (!skb_queue_empty(&be->inputq1))
1627 		tipc_node_mcast_rcv(n);
1628 
1629 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1630 	if (!skb_queue_empty(&n->bc_entry.namedq))
1631 		tipc_named_rcv(net, &n->bc_entry.namedq);
1632 
1633 	/* If reassembly or retransmission failure => reset all links to peer */
1634 	if (rc & TIPC_LINK_DOWN_EVT)
1635 		tipc_node_reset_links(n);
1636 
1637 	tipc_node_put(n);
1638 }
1639 
1640 /**
1641  * tipc_node_check_state - check and if necessary update node state
1642  * @skb: TIPC packet
1643  * @bearer_id: identity of bearer delivering the packet
1644  * Returns true if state and msg are ok, otherwise false
1645  */
1646 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1647 				  int bearer_id, struct sk_buff_head *xmitq)
1648 {
1649 	struct tipc_msg *hdr = buf_msg(skb);
1650 	int usr = msg_user(hdr);
1651 	int mtyp = msg_type(hdr);
1652 	u16 oseqno = msg_seqno(hdr);
1653 	u16 exp_pkts = msg_msgcnt(hdr);
1654 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1655 	int state = n->state;
1656 	struct tipc_link *l, *tnl, *pl = NULL;
1657 	struct tipc_media_addr *maddr;
1658 	int pb_id;
1659 
1660 	if (trace_tipc_node_check_state_enabled()) {
1661 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1662 		trace_tipc_node_check_state(n, true, " ");
1663 	}
1664 	l = n->links[bearer_id].link;
1665 	if (!l)
1666 		return false;
1667 	rcv_nxt = tipc_link_rcv_nxt(l);
1668 
1669 
1670 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1671 		return true;
1672 
1673 	/* Find parallel link, if any */
1674 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1675 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1676 			pl = n->links[pb_id].link;
1677 			break;
1678 		}
1679 	}
1680 
1681 	if (!tipc_link_validate_msg(l, hdr)) {
1682 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1683 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1684 		return false;
1685 	}
1686 
1687 	/* Check and update node accesibility if applicable */
1688 	if (state == SELF_UP_PEER_COMING) {
1689 		if (!tipc_link_is_up(l))
1690 			return true;
1691 		if (!msg_peer_link_is_up(hdr))
1692 			return true;
1693 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1694 	}
1695 
1696 	if (state == SELF_DOWN_PEER_LEAVING) {
1697 		if (msg_peer_node_is_up(hdr))
1698 			return false;
1699 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1700 		return true;
1701 	}
1702 
1703 	if (state == SELF_LEAVING_PEER_DOWN)
1704 		return false;
1705 
1706 	/* Ignore duplicate packets */
1707 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1708 		return true;
1709 
1710 	/* Initiate or update failover mode if applicable */
1711 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1712 		syncpt = oseqno + exp_pkts - 1;
1713 		if (pl && !tipc_link_is_reset(pl)) {
1714 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1715 			trace_tipc_node_link_down(n, true,
1716 						  "node link down <- failover!");
1717 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1718 							tipc_link_inputq(l));
1719 		}
1720 
1721 		/* If parallel link was already down, and this happened before
1722 		 * the tunnel link came up, node failover was never started.
1723 		 * Ensure that a FAILOVER_MSG is sent to get peer out of
1724 		 * NODE_FAILINGOVER state, also this node must accept
1725 		 * TUNNEL_MSGs from peer.
1726 		 */
1727 		if (n->state != NODE_FAILINGOVER)
1728 			tipc_node_link_failover(n, pl, l, xmitq);
1729 
1730 		/* If pkts arrive out of order, use lowest calculated syncpt */
1731 		if (less(syncpt, n->sync_point))
1732 			n->sync_point = syncpt;
1733 	}
1734 
1735 	/* Open parallel link when tunnel link reaches synch point */
1736 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1737 		if (!more(rcv_nxt, n->sync_point))
1738 			return true;
1739 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1740 		if (pl)
1741 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1742 		return true;
1743 	}
1744 
1745 	/* No synching needed if only one link */
1746 	if (!pl || !tipc_link_is_up(pl))
1747 		return true;
1748 
1749 	/* Initiate synch mode if applicable */
1750 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1751 		if (n->capabilities & TIPC_TUNNEL_ENHANCED)
1752 			syncpt = msg_syncpt(hdr);
1753 		else
1754 			syncpt = msg_seqno(msg_inner_hdr(hdr)) + exp_pkts - 1;
1755 		if (!tipc_link_is_up(l))
1756 			__tipc_node_link_up(n, bearer_id, xmitq);
1757 		if (n->state == SELF_UP_PEER_UP) {
1758 			n->sync_point = syncpt;
1759 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1760 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1761 		}
1762 	}
1763 
1764 	/* Open tunnel link when parallel link reaches synch point */
1765 	if (n->state == NODE_SYNCHING) {
1766 		if (tipc_link_is_synching(l)) {
1767 			tnl = l;
1768 		} else {
1769 			tnl = pl;
1770 			pl = l;
1771 		}
1772 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
1773 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1774 		if (more(dlv_nxt, n->sync_point)) {
1775 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1776 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1777 			return true;
1778 		}
1779 		if (l == pl)
1780 			return true;
1781 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1782 			return true;
1783 		if (usr == LINK_PROTOCOL)
1784 			return true;
1785 		return false;
1786 	}
1787 	return true;
1788 }
1789 
1790 /**
1791  * tipc_rcv - process TIPC packets/messages arriving from off-node
1792  * @net: the applicable net namespace
1793  * @skb: TIPC packet
1794  * @bearer: pointer to bearer message arrived on
1795  *
1796  * Invoked with no locks held. Bearer pointer must point to a valid bearer
1797  * structure (i.e. cannot be NULL), but bearer can be inactive.
1798  */
1799 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1800 {
1801 	struct sk_buff_head xmitq;
1802 	struct tipc_node *n;
1803 	struct tipc_msg *hdr;
1804 	int bearer_id = b->identity;
1805 	struct tipc_link_entry *le;
1806 	u32 self = tipc_own_addr(net);
1807 	int usr, rc = 0;
1808 	u16 bc_ack;
1809 
1810 	__skb_queue_head_init(&xmitq);
1811 
1812 	/* Ensure message is well-formed before touching the header */
1813 	TIPC_SKB_CB(skb)->validated = false;
1814 	if (unlikely(!tipc_msg_validate(&skb)))
1815 		goto discard;
1816 	hdr = buf_msg(skb);
1817 	usr = msg_user(hdr);
1818 	bc_ack = msg_bcast_ack(hdr);
1819 
1820 	/* Handle arrival of discovery or broadcast packet */
1821 	if (unlikely(msg_non_seq(hdr))) {
1822 		if (unlikely(usr == LINK_CONFIG))
1823 			return tipc_disc_rcv(net, skb, b);
1824 		else
1825 			return tipc_node_bc_rcv(net, skb, bearer_id);
1826 	}
1827 
1828 	/* Discard unicast link messages destined for another node */
1829 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
1830 		goto discard;
1831 
1832 	/* Locate neighboring node that sent packet */
1833 	n = tipc_node_find(net, msg_prevnode(hdr));
1834 	if (unlikely(!n))
1835 		goto discard;
1836 	le = &n->links[bearer_id];
1837 
1838 	/* Ensure broadcast reception is in synch with peer's send state */
1839 	if (unlikely(usr == LINK_PROTOCOL))
1840 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
1841 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
1842 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
1843 
1844 	/* Receive packet directly if conditions permit */
1845 	tipc_node_read_lock(n);
1846 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
1847 		spin_lock_bh(&le->lock);
1848 		if (le->link) {
1849 			rc = tipc_link_rcv(le->link, skb, &xmitq);
1850 			skb = NULL;
1851 		}
1852 		spin_unlock_bh(&le->lock);
1853 	}
1854 	tipc_node_read_unlock(n);
1855 
1856 	/* Check/update node state before receiving */
1857 	if (unlikely(skb)) {
1858 		if (unlikely(skb_linearize(skb)))
1859 			goto discard;
1860 		tipc_node_write_lock(n);
1861 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
1862 			if (le->link) {
1863 				rc = tipc_link_rcv(le->link, skb, &xmitq);
1864 				skb = NULL;
1865 			}
1866 		}
1867 		tipc_node_write_unlock(n);
1868 	}
1869 
1870 	if (unlikely(rc & TIPC_LINK_UP_EVT))
1871 		tipc_node_link_up(n, bearer_id, &xmitq);
1872 
1873 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1874 		tipc_node_link_down(n, bearer_id, false);
1875 
1876 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1877 		tipc_named_rcv(net, &n->bc_entry.namedq);
1878 
1879 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
1880 		tipc_node_mcast_rcv(n);
1881 
1882 	if (!skb_queue_empty(&le->inputq))
1883 		tipc_sk_rcv(net, &le->inputq);
1884 
1885 	if (!skb_queue_empty(&xmitq))
1886 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1887 
1888 	tipc_node_put(n);
1889 discard:
1890 	kfree_skb(skb);
1891 }
1892 
1893 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
1894 			      int prop)
1895 {
1896 	struct tipc_net *tn = tipc_net(net);
1897 	int bearer_id = b->identity;
1898 	struct sk_buff_head xmitq;
1899 	struct tipc_link_entry *e;
1900 	struct tipc_node *n;
1901 
1902 	__skb_queue_head_init(&xmitq);
1903 
1904 	rcu_read_lock();
1905 
1906 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1907 		tipc_node_write_lock(n);
1908 		e = &n->links[bearer_id];
1909 		if (e->link) {
1910 			if (prop == TIPC_NLA_PROP_TOL)
1911 				tipc_link_set_tolerance(e->link, b->tolerance,
1912 							&xmitq);
1913 			else if (prop == TIPC_NLA_PROP_MTU)
1914 				tipc_link_set_mtu(e->link, b->mtu);
1915 		}
1916 		tipc_node_write_unlock(n);
1917 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
1918 	}
1919 
1920 	rcu_read_unlock();
1921 }
1922 
1923 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
1924 {
1925 	struct net *net = sock_net(skb->sk);
1926 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1927 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
1928 	struct tipc_node *peer;
1929 	u32 addr;
1930 	int err;
1931 
1932 	/* We identify the peer by its net */
1933 	if (!info->attrs[TIPC_NLA_NET])
1934 		return -EINVAL;
1935 
1936 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
1937 					  info->attrs[TIPC_NLA_NET],
1938 					  tipc_nl_net_policy, info->extack);
1939 	if (err)
1940 		return err;
1941 
1942 	if (!attrs[TIPC_NLA_NET_ADDR])
1943 		return -EINVAL;
1944 
1945 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
1946 
1947 	if (in_own_node(net, addr))
1948 		return -ENOTSUPP;
1949 
1950 	spin_lock_bh(&tn->node_list_lock);
1951 	peer = tipc_node_find(net, addr);
1952 	if (!peer) {
1953 		spin_unlock_bh(&tn->node_list_lock);
1954 		return -ENXIO;
1955 	}
1956 
1957 	tipc_node_write_lock(peer);
1958 	if (peer->state != SELF_DOWN_PEER_DOWN &&
1959 	    peer->state != SELF_DOWN_PEER_LEAVING) {
1960 		tipc_node_write_unlock(peer);
1961 		err = -EBUSY;
1962 		goto err_out;
1963 	}
1964 
1965 	tipc_node_clear_links(peer);
1966 	tipc_node_write_unlock(peer);
1967 	tipc_node_delete(peer);
1968 
1969 	err = 0;
1970 err_out:
1971 	tipc_node_put(peer);
1972 	spin_unlock_bh(&tn->node_list_lock);
1973 
1974 	return err;
1975 }
1976 
1977 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1978 {
1979 	int err;
1980 	struct net *net = sock_net(skb->sk);
1981 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1982 	int done = cb->args[0];
1983 	int last_addr = cb->args[1];
1984 	struct tipc_node *node;
1985 	struct tipc_nl_msg msg;
1986 
1987 	if (done)
1988 		return 0;
1989 
1990 	msg.skb = skb;
1991 	msg.portid = NETLINK_CB(cb->skb).portid;
1992 	msg.seq = cb->nlh->nlmsg_seq;
1993 
1994 	rcu_read_lock();
1995 	if (last_addr) {
1996 		node = tipc_node_find(net, last_addr);
1997 		if (!node) {
1998 			rcu_read_unlock();
1999 			/* We never set seq or call nl_dump_check_consistent()
2000 			 * this means that setting prev_seq here will cause the
2001 			 * consistence check to fail in the netlink callback
2002 			 * handler. Resulting in the NLMSG_DONE message having
2003 			 * the NLM_F_DUMP_INTR flag set if the node state
2004 			 * changed while we released the lock.
2005 			 */
2006 			cb->prev_seq = 1;
2007 			return -EPIPE;
2008 		}
2009 		tipc_node_put(node);
2010 	}
2011 
2012 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2013 		if (last_addr) {
2014 			if (node->addr == last_addr)
2015 				last_addr = 0;
2016 			else
2017 				continue;
2018 		}
2019 
2020 		tipc_node_read_lock(node);
2021 		err = __tipc_nl_add_node(&msg, node);
2022 		if (err) {
2023 			last_addr = node->addr;
2024 			tipc_node_read_unlock(node);
2025 			goto out;
2026 		}
2027 
2028 		tipc_node_read_unlock(node);
2029 	}
2030 	done = 1;
2031 out:
2032 	cb->args[0] = done;
2033 	cb->args[1] = last_addr;
2034 	rcu_read_unlock();
2035 
2036 	return skb->len;
2037 }
2038 
2039 /* tipc_node_find_by_name - locate owner node of link by link's name
2040  * @net: the applicable net namespace
2041  * @name: pointer to link name string
2042  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2043  *
2044  * Returns pointer to node owning the link, or 0 if no matching link is found.
2045  */
2046 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2047 						const char *link_name,
2048 						unsigned int *bearer_id)
2049 {
2050 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2051 	struct tipc_link *l;
2052 	struct tipc_node *n;
2053 	struct tipc_node *found_node = NULL;
2054 	int i;
2055 
2056 	*bearer_id = 0;
2057 	rcu_read_lock();
2058 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2059 		tipc_node_read_lock(n);
2060 		for (i = 0; i < MAX_BEARERS; i++) {
2061 			l = n->links[i].link;
2062 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2063 				*bearer_id = i;
2064 				found_node = n;
2065 				break;
2066 			}
2067 		}
2068 		tipc_node_read_unlock(n);
2069 		if (found_node)
2070 			break;
2071 	}
2072 	rcu_read_unlock();
2073 
2074 	return found_node;
2075 }
2076 
2077 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2078 {
2079 	int err;
2080 	int res = 0;
2081 	int bearer_id;
2082 	char *name;
2083 	struct tipc_link *link;
2084 	struct tipc_node *node;
2085 	struct sk_buff_head xmitq;
2086 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2087 	struct net *net = sock_net(skb->sk);
2088 
2089 	__skb_queue_head_init(&xmitq);
2090 
2091 	if (!info->attrs[TIPC_NLA_LINK])
2092 		return -EINVAL;
2093 
2094 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2095 					  info->attrs[TIPC_NLA_LINK],
2096 					  tipc_nl_link_policy, info->extack);
2097 	if (err)
2098 		return err;
2099 
2100 	if (!attrs[TIPC_NLA_LINK_NAME])
2101 		return -EINVAL;
2102 
2103 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2104 
2105 	if (strcmp(name, tipc_bclink_name) == 0)
2106 		return tipc_nl_bc_link_set(net, attrs);
2107 
2108 	node = tipc_node_find_by_name(net, name, &bearer_id);
2109 	if (!node)
2110 		return -EINVAL;
2111 
2112 	tipc_node_read_lock(node);
2113 
2114 	link = node->links[bearer_id].link;
2115 	if (!link) {
2116 		res = -EINVAL;
2117 		goto out;
2118 	}
2119 
2120 	if (attrs[TIPC_NLA_LINK_PROP]) {
2121 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2122 
2123 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2124 					      props);
2125 		if (err) {
2126 			res = err;
2127 			goto out;
2128 		}
2129 
2130 		if (props[TIPC_NLA_PROP_TOL]) {
2131 			u32 tol;
2132 
2133 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2134 			tipc_link_set_tolerance(link, tol, &xmitq);
2135 		}
2136 		if (props[TIPC_NLA_PROP_PRIO]) {
2137 			u32 prio;
2138 
2139 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2140 			tipc_link_set_prio(link, prio, &xmitq);
2141 		}
2142 		if (props[TIPC_NLA_PROP_WIN]) {
2143 			u32 win;
2144 
2145 			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2146 			tipc_link_set_queue_limits(link, win);
2147 		}
2148 	}
2149 
2150 out:
2151 	tipc_node_read_unlock(node);
2152 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
2153 	return res;
2154 }
2155 
2156 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2157 {
2158 	struct net *net = genl_info_net(info);
2159 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2160 	struct tipc_nl_msg msg;
2161 	char *name;
2162 	int err;
2163 
2164 	msg.portid = info->snd_portid;
2165 	msg.seq = info->snd_seq;
2166 
2167 	if (!info->attrs[TIPC_NLA_LINK])
2168 		return -EINVAL;
2169 
2170 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2171 					  info->attrs[TIPC_NLA_LINK],
2172 					  tipc_nl_link_policy, info->extack);
2173 	if (err)
2174 		return err;
2175 
2176 	if (!attrs[TIPC_NLA_LINK_NAME])
2177 		return -EINVAL;
2178 
2179 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2180 
2181 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2182 	if (!msg.skb)
2183 		return -ENOMEM;
2184 
2185 	if (strcmp(name, tipc_bclink_name) == 0) {
2186 		err = tipc_nl_add_bc_link(net, &msg);
2187 		if (err)
2188 			goto err_free;
2189 	} else {
2190 		int bearer_id;
2191 		struct tipc_node *node;
2192 		struct tipc_link *link;
2193 
2194 		node = tipc_node_find_by_name(net, name, &bearer_id);
2195 		if (!node) {
2196 			err = -EINVAL;
2197 			goto err_free;
2198 		}
2199 
2200 		tipc_node_read_lock(node);
2201 		link = node->links[bearer_id].link;
2202 		if (!link) {
2203 			tipc_node_read_unlock(node);
2204 			err = -EINVAL;
2205 			goto err_free;
2206 		}
2207 
2208 		err = __tipc_nl_add_link(net, &msg, link, 0);
2209 		tipc_node_read_unlock(node);
2210 		if (err)
2211 			goto err_free;
2212 	}
2213 
2214 	return genlmsg_reply(msg.skb, info);
2215 
2216 err_free:
2217 	nlmsg_free(msg.skb);
2218 	return err;
2219 }
2220 
2221 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2222 {
2223 	int err;
2224 	char *link_name;
2225 	unsigned int bearer_id;
2226 	struct tipc_link *link;
2227 	struct tipc_node *node;
2228 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2229 	struct net *net = sock_net(skb->sk);
2230 	struct tipc_link_entry *le;
2231 
2232 	if (!info->attrs[TIPC_NLA_LINK])
2233 		return -EINVAL;
2234 
2235 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2236 					  info->attrs[TIPC_NLA_LINK],
2237 					  tipc_nl_link_policy, info->extack);
2238 	if (err)
2239 		return err;
2240 
2241 	if (!attrs[TIPC_NLA_LINK_NAME])
2242 		return -EINVAL;
2243 
2244 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2245 
2246 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2247 		err = tipc_bclink_reset_stats(net);
2248 		if (err)
2249 			return err;
2250 		return 0;
2251 	}
2252 
2253 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2254 	if (!node)
2255 		return -EINVAL;
2256 
2257 	le = &node->links[bearer_id];
2258 	tipc_node_read_lock(node);
2259 	spin_lock_bh(&le->lock);
2260 	link = node->links[bearer_id].link;
2261 	if (!link) {
2262 		spin_unlock_bh(&le->lock);
2263 		tipc_node_read_unlock(node);
2264 		return -EINVAL;
2265 	}
2266 	tipc_link_reset_stats(link);
2267 	spin_unlock_bh(&le->lock);
2268 	tipc_node_read_unlock(node);
2269 	return 0;
2270 }
2271 
2272 /* Caller should hold node lock  */
2273 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2274 				    struct tipc_node *node, u32 *prev_link)
2275 {
2276 	u32 i;
2277 	int err;
2278 
2279 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2280 		*prev_link = i;
2281 
2282 		if (!node->links[i].link)
2283 			continue;
2284 
2285 		err = __tipc_nl_add_link(net, msg,
2286 					 node->links[i].link, NLM_F_MULTI);
2287 		if (err)
2288 			return err;
2289 	}
2290 	*prev_link = 0;
2291 
2292 	return 0;
2293 }
2294 
2295 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2296 {
2297 	struct net *net = sock_net(skb->sk);
2298 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2299 	struct tipc_node *node;
2300 	struct tipc_nl_msg msg;
2301 	u32 prev_node = cb->args[0];
2302 	u32 prev_link = cb->args[1];
2303 	int done = cb->args[2];
2304 	int err;
2305 
2306 	if (done)
2307 		return 0;
2308 
2309 	msg.skb = skb;
2310 	msg.portid = NETLINK_CB(cb->skb).portid;
2311 	msg.seq = cb->nlh->nlmsg_seq;
2312 
2313 	rcu_read_lock();
2314 	if (prev_node) {
2315 		node = tipc_node_find(net, prev_node);
2316 		if (!node) {
2317 			/* We never set seq or call nl_dump_check_consistent()
2318 			 * this means that setting prev_seq here will cause the
2319 			 * consistence check to fail in the netlink callback
2320 			 * handler. Resulting in the last NLMSG_DONE message
2321 			 * having the NLM_F_DUMP_INTR flag set.
2322 			 */
2323 			cb->prev_seq = 1;
2324 			goto out;
2325 		}
2326 		tipc_node_put(node);
2327 
2328 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2329 						 list) {
2330 			tipc_node_read_lock(node);
2331 			err = __tipc_nl_add_node_links(net, &msg, node,
2332 						       &prev_link);
2333 			tipc_node_read_unlock(node);
2334 			if (err)
2335 				goto out;
2336 
2337 			prev_node = node->addr;
2338 		}
2339 	} else {
2340 		err = tipc_nl_add_bc_link(net, &msg);
2341 		if (err)
2342 			goto out;
2343 
2344 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2345 			tipc_node_read_lock(node);
2346 			err = __tipc_nl_add_node_links(net, &msg, node,
2347 						       &prev_link);
2348 			tipc_node_read_unlock(node);
2349 			if (err)
2350 				goto out;
2351 
2352 			prev_node = node->addr;
2353 		}
2354 	}
2355 	done = 1;
2356 out:
2357 	rcu_read_unlock();
2358 
2359 	cb->args[0] = prev_node;
2360 	cb->args[1] = prev_link;
2361 	cb->args[2] = done;
2362 
2363 	return skb->len;
2364 }
2365 
2366 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2367 {
2368 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2369 	struct net *net = sock_net(skb->sk);
2370 	int err;
2371 
2372 	if (!info->attrs[TIPC_NLA_MON])
2373 		return -EINVAL;
2374 
2375 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2376 					  info->attrs[TIPC_NLA_MON],
2377 					  tipc_nl_monitor_policy,
2378 					  info->extack);
2379 	if (err)
2380 		return err;
2381 
2382 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2383 		u32 val;
2384 
2385 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2386 		err = tipc_nl_monitor_set_threshold(net, val);
2387 		if (err)
2388 			return err;
2389 	}
2390 
2391 	return 0;
2392 }
2393 
2394 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2395 {
2396 	struct nlattr *attrs;
2397 	void *hdr;
2398 	u32 val;
2399 
2400 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2401 			  0, TIPC_NL_MON_GET);
2402 	if (!hdr)
2403 		return -EMSGSIZE;
2404 
2405 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2406 	if (!attrs)
2407 		goto msg_full;
2408 
2409 	val = tipc_nl_monitor_get_threshold(net);
2410 
2411 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2412 		goto attr_msg_full;
2413 
2414 	nla_nest_end(msg->skb, attrs);
2415 	genlmsg_end(msg->skb, hdr);
2416 
2417 	return 0;
2418 
2419 attr_msg_full:
2420 	nla_nest_cancel(msg->skb, attrs);
2421 msg_full:
2422 	genlmsg_cancel(msg->skb, hdr);
2423 
2424 	return -EMSGSIZE;
2425 }
2426 
2427 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2428 {
2429 	struct net *net = sock_net(skb->sk);
2430 	struct tipc_nl_msg msg;
2431 	int err;
2432 
2433 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2434 	if (!msg.skb)
2435 		return -ENOMEM;
2436 	msg.portid = info->snd_portid;
2437 	msg.seq = info->snd_seq;
2438 
2439 	err = __tipc_nl_add_monitor_prop(net, &msg);
2440 	if (err) {
2441 		nlmsg_free(msg.skb);
2442 		return err;
2443 	}
2444 
2445 	return genlmsg_reply(msg.skb, info);
2446 }
2447 
2448 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2449 {
2450 	struct net *net = sock_net(skb->sk);
2451 	u32 prev_bearer = cb->args[0];
2452 	struct tipc_nl_msg msg;
2453 	int bearer_id;
2454 	int err;
2455 
2456 	if (prev_bearer == MAX_BEARERS)
2457 		return 0;
2458 
2459 	msg.skb = skb;
2460 	msg.portid = NETLINK_CB(cb->skb).portid;
2461 	msg.seq = cb->nlh->nlmsg_seq;
2462 
2463 	rtnl_lock();
2464 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2465 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2466 		if (err)
2467 			break;
2468 	}
2469 	rtnl_unlock();
2470 	cb->args[0] = bearer_id;
2471 
2472 	return skb->len;
2473 }
2474 
2475 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2476 				   struct netlink_callback *cb)
2477 {
2478 	struct net *net = sock_net(skb->sk);
2479 	u32 prev_node = cb->args[1];
2480 	u32 bearer_id = cb->args[2];
2481 	int done = cb->args[0];
2482 	struct tipc_nl_msg msg;
2483 	int err;
2484 
2485 	if (!prev_node) {
2486 		struct nlattr **attrs;
2487 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2488 
2489 		err = tipc_nlmsg_parse(cb->nlh, &attrs);
2490 		if (err)
2491 			return err;
2492 
2493 		if (!attrs[TIPC_NLA_MON])
2494 			return -EINVAL;
2495 
2496 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2497 						  attrs[TIPC_NLA_MON],
2498 						  tipc_nl_monitor_policy,
2499 						  NULL);
2500 		if (err)
2501 			return err;
2502 
2503 		if (!mon[TIPC_NLA_MON_REF])
2504 			return -EINVAL;
2505 
2506 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2507 
2508 		if (bearer_id >= MAX_BEARERS)
2509 			return -EINVAL;
2510 	}
2511 
2512 	if (done)
2513 		return 0;
2514 
2515 	msg.skb = skb;
2516 	msg.portid = NETLINK_CB(cb->skb).portid;
2517 	msg.seq = cb->nlh->nlmsg_seq;
2518 
2519 	rtnl_lock();
2520 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2521 	if (!err)
2522 		done = 1;
2523 
2524 	rtnl_unlock();
2525 	cb->args[0] = done;
2526 	cb->args[1] = prev_node;
2527 	cb->args[2] = bearer_id;
2528 
2529 	return skb->len;
2530 }
2531 
2532 u32 tipc_node_get_addr(struct tipc_node *node)
2533 {
2534 	return (node) ? node->addr : 0;
2535 }
2536 
2537 /**
2538  * tipc_node_dump - dump TIPC node data
2539  * @n: tipc node to be dumped
2540  * @more: dump more?
2541  *        - false: dump only tipc node data
2542  *        - true: dump node link data as well
2543  * @buf: returned buffer of dump data in format
2544  */
2545 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2546 {
2547 	int i = 0;
2548 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2549 
2550 	if (!n) {
2551 		i += scnprintf(buf, sz, "node data: (null)\n");
2552 		return i;
2553 	}
2554 
2555 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2556 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2557 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2558 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2559 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
2560 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
2561 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
2562 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
2563 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
2564 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
2565 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
2566 
2567 	if (!more)
2568 		return i;
2569 
2570 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
2571 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
2572 	i += scnprintf(buf + i, sz - i, " media: ");
2573 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
2574 	i += scnprintf(buf + i, sz - i, "\n");
2575 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
2576 	i += scnprintf(buf + i, sz - i, " inputq: ");
2577 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
2578 
2579 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
2580 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
2581 	i += scnprintf(buf + i, sz - i, " media: ");
2582 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
2583 	i += scnprintf(buf + i, sz - i, "\n");
2584 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
2585 	i += scnprintf(buf + i, sz - i, " inputq: ");
2586 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
2587 
2588 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
2589 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
2590 
2591 	return i;
2592 }
2593