xref: /openbmc/linux/net/tipc/node.c (revision d8eabc37)
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 		write_lock_bh(&n->lock);
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 		write_unlock_bh(&n->lock);
386 		goto exit;
387 	}
388 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
389 	if (!n) {
390 		pr_warn("Node creation failed, no memory\n");
391 		goto exit;
392 	}
393 	n->addr = addr;
394 	memcpy(&n->peer_id, peer_id, 16);
395 	n->net = net;
396 	n->capabilities = capabilities;
397 	kref_init(&n->kref);
398 	rwlock_init(&n->lock);
399 	INIT_HLIST_NODE(&n->hash);
400 	INIT_LIST_HEAD(&n->list);
401 	INIT_LIST_HEAD(&n->publ_list);
402 	INIT_LIST_HEAD(&n->conn_sks);
403 	skb_queue_head_init(&n->bc_entry.namedq);
404 	skb_queue_head_init(&n->bc_entry.inputq1);
405 	__skb_queue_head_init(&n->bc_entry.arrvq);
406 	skb_queue_head_init(&n->bc_entry.inputq2);
407 	for (i = 0; i < MAX_BEARERS; i++)
408 		spin_lock_init(&n->links[i].lock);
409 	n->state = SELF_DOWN_PEER_LEAVING;
410 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
411 	n->signature = INVALID_NODE_SIG;
412 	n->active_links[0] = INVALID_BEARER_ID;
413 	n->active_links[1] = INVALID_BEARER_ID;
414 	if (!tipc_link_bc_create(net, tipc_own_addr(net),
415 				 addr, U16_MAX,
416 				 tipc_link_window(tipc_bc_sndlink(net)),
417 				 n->capabilities,
418 				 &n->bc_entry.inputq1,
419 				 &n->bc_entry.namedq,
420 				 tipc_bc_sndlink(net),
421 				 &n->bc_entry.link)) {
422 		pr_warn("Broadcast rcv link creation failed, no memory\n");
423 		kfree(n);
424 		n = NULL;
425 		goto exit;
426 	}
427 	tipc_node_get(n);
428 	timer_setup(&n->timer, tipc_node_timeout, 0);
429 	n->keepalive_intv = U32_MAX;
430 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
431 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
432 		if (n->addr < temp_node->addr)
433 			break;
434 	}
435 	list_add_tail_rcu(&n->list, &temp_node->list);
436 	trace_tipc_node_create(n, true, " ");
437 exit:
438 	spin_unlock_bh(&tn->node_list_lock);
439 	return n;
440 }
441 
442 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
443 {
444 	unsigned long tol = tipc_link_tolerance(l);
445 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
446 
447 	/* Link with lowest tolerance determines timer interval */
448 	if (intv < n->keepalive_intv)
449 		n->keepalive_intv = intv;
450 
451 	/* Ensure link's abort limit corresponds to current tolerance */
452 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
453 }
454 
455 static void tipc_node_delete_from_list(struct tipc_node *node)
456 {
457 	list_del_rcu(&node->list);
458 	hlist_del_rcu(&node->hash);
459 	tipc_node_put(node);
460 }
461 
462 static void tipc_node_delete(struct tipc_node *node)
463 {
464 	trace_tipc_node_delete(node, true, " ");
465 	tipc_node_delete_from_list(node);
466 
467 	del_timer_sync(&node->timer);
468 	tipc_node_put(node);
469 }
470 
471 void tipc_node_stop(struct net *net)
472 {
473 	struct tipc_net *tn = tipc_net(net);
474 	struct tipc_node *node, *t_node;
475 
476 	spin_lock_bh(&tn->node_list_lock);
477 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
478 		tipc_node_delete(node);
479 	spin_unlock_bh(&tn->node_list_lock);
480 }
481 
482 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
483 {
484 	struct tipc_node *n;
485 
486 	if (in_own_node(net, addr))
487 		return;
488 
489 	n = tipc_node_find(net, addr);
490 	if (!n) {
491 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
492 		return;
493 	}
494 	tipc_node_write_lock(n);
495 	list_add_tail(subscr, &n->publ_list);
496 	tipc_node_write_unlock_fast(n);
497 	tipc_node_put(n);
498 }
499 
500 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
501 {
502 	struct tipc_node *n;
503 
504 	if (in_own_node(net, addr))
505 		return;
506 
507 	n = tipc_node_find(net, addr);
508 	if (!n) {
509 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
510 		return;
511 	}
512 	tipc_node_write_lock(n);
513 	list_del_init(subscr);
514 	tipc_node_write_unlock_fast(n);
515 	tipc_node_put(n);
516 }
517 
518 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
519 {
520 	struct tipc_node *node;
521 	struct tipc_sock_conn *conn;
522 	int err = 0;
523 
524 	if (in_own_node(net, dnode))
525 		return 0;
526 
527 	node = tipc_node_find(net, dnode);
528 	if (!node) {
529 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
530 		return -EHOSTUNREACH;
531 	}
532 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
533 	if (!conn) {
534 		err = -EHOSTUNREACH;
535 		goto exit;
536 	}
537 	conn->peer_node = dnode;
538 	conn->port = port;
539 	conn->peer_port = peer_port;
540 
541 	tipc_node_write_lock(node);
542 	list_add_tail(&conn->list, &node->conn_sks);
543 	tipc_node_write_unlock(node);
544 exit:
545 	tipc_node_put(node);
546 	return err;
547 }
548 
549 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
550 {
551 	struct tipc_node *node;
552 	struct tipc_sock_conn *conn, *safe;
553 
554 	if (in_own_node(net, dnode))
555 		return;
556 
557 	node = tipc_node_find(net, dnode);
558 	if (!node)
559 		return;
560 
561 	tipc_node_write_lock(node);
562 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
563 		if (port != conn->port)
564 			continue;
565 		list_del(&conn->list);
566 		kfree(conn);
567 	}
568 	tipc_node_write_unlock(node);
569 	tipc_node_put(node);
570 }
571 
572 static void  tipc_node_clear_links(struct tipc_node *node)
573 {
574 	int i;
575 
576 	for (i = 0; i < MAX_BEARERS; i++) {
577 		struct tipc_link_entry *le = &node->links[i];
578 
579 		if (le->link) {
580 			kfree(le->link);
581 			le->link = NULL;
582 			node->link_cnt--;
583 		}
584 	}
585 }
586 
587 /* tipc_node_cleanup - delete nodes that does not
588  * have active links for NODE_CLEANUP_AFTER time
589  */
590 static bool tipc_node_cleanup(struct tipc_node *peer)
591 {
592 	struct tipc_net *tn = tipc_net(peer->net);
593 	bool deleted = false;
594 
595 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
596 	if (!spin_trylock_bh(&tn->node_list_lock))
597 		return false;
598 
599 	tipc_node_write_lock(peer);
600 
601 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
602 		tipc_node_clear_links(peer);
603 		tipc_node_delete_from_list(peer);
604 		deleted = true;
605 	}
606 	tipc_node_write_unlock(peer);
607 	spin_unlock_bh(&tn->node_list_lock);
608 	return deleted;
609 }
610 
611 /* tipc_node_timeout - handle expiration of node timer
612  */
613 static void tipc_node_timeout(struct timer_list *t)
614 {
615 	struct tipc_node *n = from_timer(n, t, timer);
616 	struct tipc_link_entry *le;
617 	struct sk_buff_head xmitq;
618 	int remains = n->link_cnt;
619 	int bearer_id;
620 	int rc = 0;
621 
622 	trace_tipc_node_timeout(n, false, " ");
623 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
624 		/*Removing the reference of Timer*/
625 		tipc_node_put(n);
626 		return;
627 	}
628 
629 	__skb_queue_head_init(&xmitq);
630 
631 	/* Initial node interval to value larger (10 seconds), then it will be
632 	 * recalculated with link lowest tolerance
633 	 */
634 	tipc_node_read_lock(n);
635 	n->keepalive_intv = 10000;
636 	tipc_node_read_unlock(n);
637 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
638 		tipc_node_read_lock(n);
639 		le = &n->links[bearer_id];
640 		if (le->link) {
641 			spin_lock_bh(&le->lock);
642 			/* Link tolerance may change asynchronously: */
643 			tipc_node_calculate_timer(n, le->link);
644 			rc = tipc_link_timeout(le->link, &xmitq);
645 			spin_unlock_bh(&le->lock);
646 			remains--;
647 		}
648 		tipc_node_read_unlock(n);
649 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
650 		if (rc & TIPC_LINK_DOWN_EVT)
651 			tipc_node_link_down(n, bearer_id, false);
652 	}
653 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
654 }
655 
656 /**
657  * __tipc_node_link_up - handle addition of link
658  * Node lock must be held by caller
659  * Link becomes active (alone or shared) or standby, depending on its priority.
660  */
661 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
662 				struct sk_buff_head *xmitq)
663 {
664 	int *slot0 = &n->active_links[0];
665 	int *slot1 = &n->active_links[1];
666 	struct tipc_link *ol = node_active_link(n, 0);
667 	struct tipc_link *nl = n->links[bearer_id].link;
668 
669 	if (!nl || tipc_link_is_up(nl))
670 		return;
671 
672 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
673 	if (!tipc_link_is_up(nl))
674 		return;
675 
676 	n->working_links++;
677 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
678 	n->link_id = tipc_link_id(nl);
679 
680 	/* Leave room for tunnel header when returning 'mtu' to users: */
681 	n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
682 
683 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
684 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
685 
686 	pr_debug("Established link <%s> on network plane %c\n",
687 		 tipc_link_name(nl), tipc_link_plane(nl));
688 	trace_tipc_node_link_up(n, true, " ");
689 
690 	/* Ensure that a STATE message goes first */
691 	tipc_link_build_state_msg(nl, xmitq);
692 
693 	/* First link? => give it both slots */
694 	if (!ol) {
695 		*slot0 = bearer_id;
696 		*slot1 = bearer_id;
697 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
698 		n->failover_sent = false;
699 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
700 		tipc_link_set_active(nl, true);
701 		tipc_bcast_add_peer(n->net, nl, xmitq);
702 		return;
703 	}
704 
705 	/* Second link => redistribute slots */
706 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
707 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
708 		*slot0 = bearer_id;
709 		*slot1 = bearer_id;
710 		tipc_link_set_active(nl, true);
711 		tipc_link_set_active(ol, false);
712 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
713 		tipc_link_set_active(nl, true);
714 		*slot1 = bearer_id;
715 	} else {
716 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
717 	}
718 
719 	/* Prepare synchronization with first link */
720 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
721 }
722 
723 /**
724  * tipc_node_link_up - handle addition of link
725  *
726  * Link becomes active (alone or shared) or standby, depending on its priority.
727  */
728 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
729 			      struct sk_buff_head *xmitq)
730 {
731 	struct tipc_media_addr *maddr;
732 
733 	tipc_node_write_lock(n);
734 	__tipc_node_link_up(n, bearer_id, xmitq);
735 	maddr = &n->links[bearer_id].maddr;
736 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
737 	tipc_node_write_unlock(n);
738 }
739 
740 /**
741  * __tipc_node_link_down - handle loss of link
742  */
743 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
744 				  struct sk_buff_head *xmitq,
745 				  struct tipc_media_addr **maddr)
746 {
747 	struct tipc_link_entry *le = &n->links[*bearer_id];
748 	int *slot0 = &n->active_links[0];
749 	int *slot1 = &n->active_links[1];
750 	int i, highest = 0, prio;
751 	struct tipc_link *l, *_l, *tnl;
752 
753 	l = n->links[*bearer_id].link;
754 	if (!l || tipc_link_is_reset(l))
755 		return;
756 
757 	n->working_links--;
758 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
759 	n->link_id = tipc_link_id(l);
760 
761 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
762 
763 	pr_debug("Lost link <%s> on network plane %c\n",
764 		 tipc_link_name(l), tipc_link_plane(l));
765 
766 	/* Select new active link if any available */
767 	*slot0 = INVALID_BEARER_ID;
768 	*slot1 = INVALID_BEARER_ID;
769 	for (i = 0; i < MAX_BEARERS; i++) {
770 		_l = n->links[i].link;
771 		if (!_l || !tipc_link_is_up(_l))
772 			continue;
773 		if (_l == l)
774 			continue;
775 		prio = tipc_link_prio(_l);
776 		if (prio < highest)
777 			continue;
778 		if (prio > highest) {
779 			highest = prio;
780 			*slot0 = i;
781 			*slot1 = i;
782 			continue;
783 		}
784 		*slot1 = i;
785 	}
786 
787 	if (!node_is_up(n)) {
788 		if (tipc_link_peer_is_down(l))
789 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
790 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
791 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
792 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
793 		tipc_link_reset(l);
794 		tipc_link_build_reset_msg(l, xmitq);
795 		*maddr = &n->links[*bearer_id].maddr;
796 		node_lost_contact(n, &le->inputq);
797 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
798 		return;
799 	}
800 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
801 
802 	/* There is still a working link => initiate failover */
803 	*bearer_id = n->active_links[0];
804 	tnl = n->links[*bearer_id].link;
805 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
806 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
807 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
808 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
809 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
810 	tipc_link_reset(l);
811 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
812 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
813 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
814 	*maddr = &n->links[*bearer_id].maddr;
815 }
816 
817 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
818 {
819 	struct tipc_link_entry *le = &n->links[bearer_id];
820 	struct tipc_link *l = le->link;
821 	struct tipc_media_addr *maddr;
822 	struct sk_buff_head xmitq;
823 	int old_bearer_id = bearer_id;
824 
825 	if (!l)
826 		return;
827 
828 	__skb_queue_head_init(&xmitq);
829 
830 	tipc_node_write_lock(n);
831 	if (!tipc_link_is_establishing(l)) {
832 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
833 	} else {
834 		/* Defuse pending tipc_node_link_up() */
835 		tipc_link_reset(l);
836 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
837 	}
838 	if (delete) {
839 		kfree(l);
840 		le->link = NULL;
841 		n->link_cnt--;
842 	}
843 	trace_tipc_node_link_down(n, true, "node link down or deleted!");
844 	tipc_node_write_unlock(n);
845 	if (delete)
846 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
847 	tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
848 	tipc_sk_rcv(n->net, &le->inputq);
849 }
850 
851 static bool node_is_up(struct tipc_node *n)
852 {
853 	return n->active_links[0] != INVALID_BEARER_ID;
854 }
855 
856 bool tipc_node_is_up(struct net *net, u32 addr)
857 {
858 	struct tipc_node *n;
859 	bool retval = false;
860 
861 	if (in_own_node(net, addr))
862 		return true;
863 
864 	n = tipc_node_find(net, addr);
865 	if (!n)
866 		return false;
867 	retval = node_is_up(n);
868 	tipc_node_put(n);
869 	return retval;
870 }
871 
872 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
873 {
874 	struct tipc_node *n;
875 
876 	addr ^= tipc_net(net)->random;
877 	while ((n = tipc_node_find(net, addr))) {
878 		tipc_node_put(n);
879 		addr++;
880 	}
881 	return addr;
882 }
883 
884 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
885  * Returns suggested address if any, otherwise 0
886  */
887 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
888 {
889 	struct tipc_net *tn = tipc_net(net);
890 	struct tipc_node *n;
891 
892 	/* Suggest new address if some other peer is using this one */
893 	n = tipc_node_find(net, addr);
894 	if (n) {
895 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
896 			addr = 0;
897 		tipc_node_put(n);
898 		if (!addr)
899 			return 0;
900 		return tipc_node_suggest_addr(net, addr);
901 	}
902 
903 	/* Suggest previously used address if peer is known */
904 	n = tipc_node_find_by_id(net, id);
905 	if (n) {
906 		addr = n->addr;
907 		tipc_node_put(n);
908 		return addr;
909 	}
910 
911 	/* Even this node may be in conflict */
912 	if (tn->trial_addr == addr)
913 		return tipc_node_suggest_addr(net, addr);
914 
915 	return 0;
916 }
917 
918 void tipc_node_check_dest(struct net *net, u32 addr,
919 			  u8 *peer_id, struct tipc_bearer *b,
920 			  u16 capabilities, u32 signature,
921 			  struct tipc_media_addr *maddr,
922 			  bool *respond, bool *dupl_addr)
923 {
924 	struct tipc_node *n;
925 	struct tipc_link *l;
926 	struct tipc_link_entry *le;
927 	bool addr_match = false;
928 	bool sign_match = false;
929 	bool link_up = false;
930 	bool accept_addr = false;
931 	bool reset = true;
932 	char *if_name;
933 	unsigned long intv;
934 	u16 session;
935 
936 	*dupl_addr = false;
937 	*respond = false;
938 
939 	n = tipc_node_create(net, addr, peer_id, capabilities);
940 	if (!n)
941 		return;
942 
943 	tipc_node_write_lock(n);
944 
945 	le = &n->links[b->identity];
946 
947 	/* Prepare to validate requesting node's signature and media address */
948 	l = le->link;
949 	link_up = l && tipc_link_is_up(l);
950 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
951 	sign_match = (signature == n->signature);
952 
953 	/* These three flags give us eight permutations: */
954 
955 	if (sign_match && addr_match && link_up) {
956 		/* All is fine. Do nothing. */
957 		reset = false;
958 	} else if (sign_match && addr_match && !link_up) {
959 		/* Respond. The link will come up in due time */
960 		*respond = true;
961 	} else if (sign_match && !addr_match && link_up) {
962 		/* Peer has changed i/f address without rebooting.
963 		 * If so, the link will reset soon, and the next
964 		 * discovery will be accepted. So we can ignore it.
965 		 * It may also be an cloned or malicious peer having
966 		 * chosen the same node address and signature as an
967 		 * existing one.
968 		 * Ignore requests until the link goes down, if ever.
969 		 */
970 		*dupl_addr = true;
971 	} else if (sign_match && !addr_match && !link_up) {
972 		/* Peer link has changed i/f address without rebooting.
973 		 * It may also be a cloned or malicious peer; we can't
974 		 * distinguish between the two.
975 		 * The signature is correct, so we must accept.
976 		 */
977 		accept_addr = true;
978 		*respond = true;
979 	} else if (!sign_match && addr_match && link_up) {
980 		/* Peer node rebooted. Two possibilities:
981 		 *  - Delayed re-discovery; this link endpoint has already
982 		 *    reset and re-established contact with the peer, before
983 		 *    receiving a discovery message from that node.
984 		 *    (The peer happened to receive one from this node first).
985 		 *  - The peer came back so fast that our side has not
986 		 *    discovered it yet. Probing from this side will soon
987 		 *    reset the link, since there can be no working link
988 		 *    endpoint at the peer end, and the link will re-establish.
989 		 *  Accept the signature, since it comes from a known peer.
990 		 */
991 		n->signature = signature;
992 	} else if (!sign_match && addr_match && !link_up) {
993 		/*  The peer node has rebooted.
994 		 *  Accept signature, since it is a known peer.
995 		 */
996 		n->signature = signature;
997 		*respond = true;
998 	} else if (!sign_match && !addr_match && link_up) {
999 		/* Peer rebooted with new address, or a new/duplicate peer.
1000 		 * Ignore until the link goes down, if ever.
1001 		 */
1002 		*dupl_addr = true;
1003 	} else if (!sign_match && !addr_match && !link_up) {
1004 		/* Peer rebooted with new address, or it is a new peer.
1005 		 * Accept signature and address.
1006 		 */
1007 		n->signature = signature;
1008 		accept_addr = true;
1009 		*respond = true;
1010 	}
1011 
1012 	if (!accept_addr)
1013 		goto exit;
1014 
1015 	/* Now create new link if not already existing */
1016 	if (!l) {
1017 		if (n->link_cnt == 2)
1018 			goto exit;
1019 
1020 		if_name = strchr(b->name, ':') + 1;
1021 		get_random_bytes(&session, sizeof(u16));
1022 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1023 				      b->net_plane, b->mtu, b->priority,
1024 				      b->window, session,
1025 				      tipc_own_addr(net), addr, peer_id,
1026 				      n->capabilities,
1027 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1028 				      &le->inputq,
1029 				      &n->bc_entry.namedq, &l)) {
1030 			*respond = false;
1031 			goto exit;
1032 		}
1033 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1034 		tipc_link_reset(l);
1035 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1036 		if (n->state == NODE_FAILINGOVER)
1037 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1038 		le->link = l;
1039 		n->link_cnt++;
1040 		tipc_node_calculate_timer(n, l);
1041 		if (n->link_cnt == 1) {
1042 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1043 			if (!mod_timer(&n->timer, intv))
1044 				tipc_node_get(n);
1045 		}
1046 	}
1047 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1048 exit:
1049 	tipc_node_write_unlock(n);
1050 	if (reset && l && !tipc_link_is_reset(l))
1051 		tipc_node_link_down(n, b->identity, false);
1052 	tipc_node_put(n);
1053 }
1054 
1055 void tipc_node_delete_links(struct net *net, int bearer_id)
1056 {
1057 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1058 	struct tipc_node *n;
1059 
1060 	rcu_read_lock();
1061 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1062 		tipc_node_link_down(n, bearer_id, true);
1063 	}
1064 	rcu_read_unlock();
1065 }
1066 
1067 static void tipc_node_reset_links(struct tipc_node *n)
1068 {
1069 	int i;
1070 
1071 	pr_warn("Resetting all links to %x\n", n->addr);
1072 
1073 	trace_tipc_node_reset_links(n, true, " ");
1074 	for (i = 0; i < MAX_BEARERS; i++) {
1075 		tipc_node_link_down(n, i, false);
1076 	}
1077 }
1078 
1079 /* tipc_node_fsm_evt - node finite state machine
1080  * Determines when contact is allowed with peer node
1081  */
1082 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1083 {
1084 	int state = n->state;
1085 
1086 	switch (state) {
1087 	case SELF_DOWN_PEER_DOWN:
1088 		switch (evt) {
1089 		case SELF_ESTABL_CONTACT_EVT:
1090 			state = SELF_UP_PEER_COMING;
1091 			break;
1092 		case PEER_ESTABL_CONTACT_EVT:
1093 			state = SELF_COMING_PEER_UP;
1094 			break;
1095 		case SELF_LOST_CONTACT_EVT:
1096 		case PEER_LOST_CONTACT_EVT:
1097 			break;
1098 		case NODE_SYNCH_END_EVT:
1099 		case NODE_SYNCH_BEGIN_EVT:
1100 		case NODE_FAILOVER_BEGIN_EVT:
1101 		case NODE_FAILOVER_END_EVT:
1102 		default:
1103 			goto illegal_evt;
1104 		}
1105 		break;
1106 	case SELF_UP_PEER_UP:
1107 		switch (evt) {
1108 		case SELF_LOST_CONTACT_EVT:
1109 			state = SELF_DOWN_PEER_LEAVING;
1110 			break;
1111 		case PEER_LOST_CONTACT_EVT:
1112 			state = SELF_LEAVING_PEER_DOWN;
1113 			break;
1114 		case NODE_SYNCH_BEGIN_EVT:
1115 			state = NODE_SYNCHING;
1116 			break;
1117 		case NODE_FAILOVER_BEGIN_EVT:
1118 			state = NODE_FAILINGOVER;
1119 			break;
1120 		case SELF_ESTABL_CONTACT_EVT:
1121 		case PEER_ESTABL_CONTACT_EVT:
1122 		case NODE_SYNCH_END_EVT:
1123 		case NODE_FAILOVER_END_EVT:
1124 			break;
1125 		default:
1126 			goto illegal_evt;
1127 		}
1128 		break;
1129 	case SELF_DOWN_PEER_LEAVING:
1130 		switch (evt) {
1131 		case PEER_LOST_CONTACT_EVT:
1132 			state = SELF_DOWN_PEER_DOWN;
1133 			break;
1134 		case SELF_ESTABL_CONTACT_EVT:
1135 		case PEER_ESTABL_CONTACT_EVT:
1136 		case SELF_LOST_CONTACT_EVT:
1137 			break;
1138 		case NODE_SYNCH_END_EVT:
1139 		case NODE_SYNCH_BEGIN_EVT:
1140 		case NODE_FAILOVER_BEGIN_EVT:
1141 		case NODE_FAILOVER_END_EVT:
1142 		default:
1143 			goto illegal_evt;
1144 		}
1145 		break;
1146 	case SELF_UP_PEER_COMING:
1147 		switch (evt) {
1148 		case PEER_ESTABL_CONTACT_EVT:
1149 			state = SELF_UP_PEER_UP;
1150 			break;
1151 		case SELF_LOST_CONTACT_EVT:
1152 			state = SELF_DOWN_PEER_DOWN;
1153 			break;
1154 		case SELF_ESTABL_CONTACT_EVT:
1155 		case PEER_LOST_CONTACT_EVT:
1156 		case NODE_SYNCH_END_EVT:
1157 		case NODE_FAILOVER_BEGIN_EVT:
1158 			break;
1159 		case NODE_SYNCH_BEGIN_EVT:
1160 		case NODE_FAILOVER_END_EVT:
1161 		default:
1162 			goto illegal_evt;
1163 		}
1164 		break;
1165 	case SELF_COMING_PEER_UP:
1166 		switch (evt) {
1167 		case SELF_ESTABL_CONTACT_EVT:
1168 			state = SELF_UP_PEER_UP;
1169 			break;
1170 		case PEER_LOST_CONTACT_EVT:
1171 			state = SELF_DOWN_PEER_DOWN;
1172 			break;
1173 		case SELF_LOST_CONTACT_EVT:
1174 		case PEER_ESTABL_CONTACT_EVT:
1175 			break;
1176 		case NODE_SYNCH_END_EVT:
1177 		case NODE_SYNCH_BEGIN_EVT:
1178 		case NODE_FAILOVER_BEGIN_EVT:
1179 		case NODE_FAILOVER_END_EVT:
1180 		default:
1181 			goto illegal_evt;
1182 		}
1183 		break;
1184 	case SELF_LEAVING_PEER_DOWN:
1185 		switch (evt) {
1186 		case SELF_LOST_CONTACT_EVT:
1187 			state = SELF_DOWN_PEER_DOWN;
1188 			break;
1189 		case SELF_ESTABL_CONTACT_EVT:
1190 		case PEER_ESTABL_CONTACT_EVT:
1191 		case PEER_LOST_CONTACT_EVT:
1192 			break;
1193 		case NODE_SYNCH_END_EVT:
1194 		case NODE_SYNCH_BEGIN_EVT:
1195 		case NODE_FAILOVER_BEGIN_EVT:
1196 		case NODE_FAILOVER_END_EVT:
1197 		default:
1198 			goto illegal_evt;
1199 		}
1200 		break;
1201 	case NODE_FAILINGOVER:
1202 		switch (evt) {
1203 		case SELF_LOST_CONTACT_EVT:
1204 			state = SELF_DOWN_PEER_LEAVING;
1205 			break;
1206 		case PEER_LOST_CONTACT_EVT:
1207 			state = SELF_LEAVING_PEER_DOWN;
1208 			break;
1209 		case NODE_FAILOVER_END_EVT:
1210 			state = SELF_UP_PEER_UP;
1211 			break;
1212 		case NODE_FAILOVER_BEGIN_EVT:
1213 		case SELF_ESTABL_CONTACT_EVT:
1214 		case PEER_ESTABL_CONTACT_EVT:
1215 			break;
1216 		case NODE_SYNCH_BEGIN_EVT:
1217 		case NODE_SYNCH_END_EVT:
1218 		default:
1219 			goto illegal_evt;
1220 		}
1221 		break;
1222 	case NODE_SYNCHING:
1223 		switch (evt) {
1224 		case SELF_LOST_CONTACT_EVT:
1225 			state = SELF_DOWN_PEER_LEAVING;
1226 			break;
1227 		case PEER_LOST_CONTACT_EVT:
1228 			state = SELF_LEAVING_PEER_DOWN;
1229 			break;
1230 		case NODE_SYNCH_END_EVT:
1231 			state = SELF_UP_PEER_UP;
1232 			break;
1233 		case NODE_FAILOVER_BEGIN_EVT:
1234 			state = NODE_FAILINGOVER;
1235 			break;
1236 		case NODE_SYNCH_BEGIN_EVT:
1237 		case SELF_ESTABL_CONTACT_EVT:
1238 		case PEER_ESTABL_CONTACT_EVT:
1239 			break;
1240 		case NODE_FAILOVER_END_EVT:
1241 		default:
1242 			goto illegal_evt;
1243 		}
1244 		break;
1245 	default:
1246 		pr_err("Unknown node fsm state %x\n", state);
1247 		break;
1248 	}
1249 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1250 	n->state = state;
1251 	return;
1252 
1253 illegal_evt:
1254 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1255 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1256 }
1257 
1258 static void node_lost_contact(struct tipc_node *n,
1259 			      struct sk_buff_head *inputq)
1260 {
1261 	struct tipc_sock_conn *conn, *safe;
1262 	struct tipc_link *l;
1263 	struct list_head *conns = &n->conn_sks;
1264 	struct sk_buff *skb;
1265 	uint i;
1266 
1267 	pr_debug("Lost contact with %x\n", n->addr);
1268 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1269 	trace_tipc_node_lost_contact(n, true, " ");
1270 
1271 	/* Clean up broadcast state */
1272 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1273 
1274 	/* Abort any ongoing link failover */
1275 	for (i = 0; i < MAX_BEARERS; i++) {
1276 		l = n->links[i].link;
1277 		if (l)
1278 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1279 	}
1280 
1281 	/* Notify publications from this node */
1282 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1283 
1284 	/* Notify sockets connected to node */
1285 	list_for_each_entry_safe(conn, safe, conns, list) {
1286 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1287 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1288 				      conn->peer_node, conn->port,
1289 				      conn->peer_port, TIPC_ERR_NO_NODE);
1290 		if (likely(skb))
1291 			skb_queue_tail(inputq, skb);
1292 		list_del(&conn->list);
1293 		kfree(conn);
1294 	}
1295 }
1296 
1297 /**
1298  * tipc_node_get_linkname - get the name of a link
1299  *
1300  * @bearer_id: id of the bearer
1301  * @node: peer node address
1302  * @linkname: link name output buffer
1303  *
1304  * Returns 0 on success
1305  */
1306 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1307 			   char *linkname, size_t len)
1308 {
1309 	struct tipc_link *link;
1310 	int err = -EINVAL;
1311 	struct tipc_node *node = tipc_node_find(net, addr);
1312 
1313 	if (!node)
1314 		return err;
1315 
1316 	if (bearer_id >= MAX_BEARERS)
1317 		goto exit;
1318 
1319 	tipc_node_read_lock(node);
1320 	link = node->links[bearer_id].link;
1321 	if (link) {
1322 		strncpy(linkname, tipc_link_name(link), len);
1323 		err = 0;
1324 	}
1325 	tipc_node_read_unlock(node);
1326 exit:
1327 	tipc_node_put(node);
1328 	return err;
1329 }
1330 
1331 /* Caller should hold node lock for the passed node */
1332 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1333 {
1334 	void *hdr;
1335 	struct nlattr *attrs;
1336 
1337 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1338 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1339 	if (!hdr)
1340 		return -EMSGSIZE;
1341 
1342 	attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
1343 	if (!attrs)
1344 		goto msg_full;
1345 
1346 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1347 		goto attr_msg_full;
1348 	if (node_is_up(node))
1349 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1350 			goto attr_msg_full;
1351 
1352 	nla_nest_end(msg->skb, attrs);
1353 	genlmsg_end(msg->skb, hdr);
1354 
1355 	return 0;
1356 
1357 attr_msg_full:
1358 	nla_nest_cancel(msg->skb, attrs);
1359 msg_full:
1360 	genlmsg_cancel(msg->skb, hdr);
1361 
1362 	return -EMSGSIZE;
1363 }
1364 
1365 /**
1366  * tipc_node_xmit() is the general link level function for message sending
1367  * @net: the applicable net namespace
1368  * @list: chain of buffers containing message
1369  * @dnode: address of destination node
1370  * @selector: a number used for deterministic link selection
1371  * Consumes the buffer chain.
1372  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1373  */
1374 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1375 		   u32 dnode, int selector)
1376 {
1377 	struct tipc_link_entry *le = NULL;
1378 	struct tipc_node *n;
1379 	struct sk_buff_head xmitq;
1380 	int bearer_id;
1381 	int rc;
1382 
1383 	if (in_own_node(net, dnode)) {
1384 		tipc_sk_rcv(net, list);
1385 		return 0;
1386 	}
1387 
1388 	n = tipc_node_find(net, dnode);
1389 	if (unlikely(!n)) {
1390 		skb_queue_purge(list);
1391 		return -EHOSTUNREACH;
1392 	}
1393 
1394 	tipc_node_read_lock(n);
1395 	bearer_id = n->active_links[selector & 1];
1396 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1397 		tipc_node_read_unlock(n);
1398 		tipc_node_put(n);
1399 		skb_queue_purge(list);
1400 		return -EHOSTUNREACH;
1401 	}
1402 
1403 	__skb_queue_head_init(&xmitq);
1404 	le = &n->links[bearer_id];
1405 	spin_lock_bh(&le->lock);
1406 	rc = tipc_link_xmit(le->link, list, &xmitq);
1407 	spin_unlock_bh(&le->lock);
1408 	tipc_node_read_unlock(n);
1409 
1410 	if (unlikely(rc == -ENOBUFS))
1411 		tipc_node_link_down(n, bearer_id, false);
1412 	else
1413 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1414 
1415 	tipc_node_put(n);
1416 
1417 	return rc;
1418 }
1419 
1420 /* tipc_node_xmit_skb(): send single buffer to destination
1421  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1422  * messages, which will not be rejected
1423  * The only exception is datagram messages rerouted after secondary
1424  * lookup, which are rare and safe to dispose of anyway.
1425  */
1426 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1427 		       u32 selector)
1428 {
1429 	struct sk_buff_head head;
1430 
1431 	skb_queue_head_init(&head);
1432 	__skb_queue_tail(&head, skb);
1433 	tipc_node_xmit(net, &head, dnode, selector);
1434 	return 0;
1435 }
1436 
1437 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1438  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1439  */
1440 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1441 {
1442 	struct sk_buff *skb;
1443 	u32 selector, dnode;
1444 
1445 	while ((skb = __skb_dequeue(xmitq))) {
1446 		selector = msg_origport(buf_msg(skb));
1447 		dnode = msg_destnode(buf_msg(skb));
1448 		tipc_node_xmit_skb(net, skb, dnode, selector);
1449 	}
1450 	return 0;
1451 }
1452 
1453 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1454 {
1455 	struct sk_buff *txskb;
1456 	struct tipc_node *n;
1457 	u32 dst;
1458 
1459 	rcu_read_lock();
1460 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1461 		dst = n->addr;
1462 		if (in_own_node(net, dst))
1463 			continue;
1464 		if (!node_is_up(n))
1465 			continue;
1466 		txskb = pskb_copy(skb, GFP_ATOMIC);
1467 		if (!txskb)
1468 			break;
1469 		msg_set_destnode(buf_msg(txskb), dst);
1470 		tipc_node_xmit_skb(net, txskb, dst, 0);
1471 	}
1472 	rcu_read_unlock();
1473 
1474 	kfree_skb(skb);
1475 }
1476 
1477 static void tipc_node_mcast_rcv(struct tipc_node *n)
1478 {
1479 	struct tipc_bclink_entry *be = &n->bc_entry;
1480 
1481 	/* 'arrvq' is under inputq2's lock protection */
1482 	spin_lock_bh(&be->inputq2.lock);
1483 	spin_lock_bh(&be->inputq1.lock);
1484 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1485 	spin_unlock_bh(&be->inputq1.lock);
1486 	spin_unlock_bh(&be->inputq2.lock);
1487 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1488 }
1489 
1490 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1491 				  int bearer_id, struct sk_buff_head *xmitq)
1492 {
1493 	struct tipc_link *ucl;
1494 	int rc;
1495 
1496 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1497 
1498 	if (rc & TIPC_LINK_DOWN_EVT) {
1499 		tipc_node_reset_links(n);
1500 		return;
1501 	}
1502 
1503 	if (!(rc & TIPC_LINK_SND_STATE))
1504 		return;
1505 
1506 	/* If probe message, a STATE response will be sent anyway */
1507 	if (msg_probe(hdr))
1508 		return;
1509 
1510 	/* Produce a STATE message carrying broadcast NACK */
1511 	tipc_node_read_lock(n);
1512 	ucl = n->links[bearer_id].link;
1513 	if (ucl)
1514 		tipc_link_build_state_msg(ucl, xmitq);
1515 	tipc_node_read_unlock(n);
1516 }
1517 
1518 /**
1519  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1520  * @net: the applicable net namespace
1521  * @skb: TIPC packet
1522  * @bearer_id: id of bearer message arrived on
1523  *
1524  * Invoked with no locks held.
1525  */
1526 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1527 {
1528 	int rc;
1529 	struct sk_buff_head xmitq;
1530 	struct tipc_bclink_entry *be;
1531 	struct tipc_link_entry *le;
1532 	struct tipc_msg *hdr = buf_msg(skb);
1533 	int usr = msg_user(hdr);
1534 	u32 dnode = msg_destnode(hdr);
1535 	struct tipc_node *n;
1536 
1537 	__skb_queue_head_init(&xmitq);
1538 
1539 	/* If NACK for other node, let rcv link for that node peek into it */
1540 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1541 		n = tipc_node_find(net, dnode);
1542 	else
1543 		n = tipc_node_find(net, msg_prevnode(hdr));
1544 	if (!n) {
1545 		kfree_skb(skb);
1546 		return;
1547 	}
1548 	be = &n->bc_entry;
1549 	le = &n->links[bearer_id];
1550 
1551 	rc = tipc_bcast_rcv(net, be->link, skb);
1552 
1553 	/* Broadcast ACKs are sent on a unicast link */
1554 	if (rc & TIPC_LINK_SND_STATE) {
1555 		tipc_node_read_lock(n);
1556 		tipc_link_build_state_msg(le->link, &xmitq);
1557 		tipc_node_read_unlock(n);
1558 	}
1559 
1560 	if (!skb_queue_empty(&xmitq))
1561 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1562 
1563 	if (!skb_queue_empty(&be->inputq1))
1564 		tipc_node_mcast_rcv(n);
1565 
1566 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1567 	if (!skb_queue_empty(&n->bc_entry.namedq))
1568 		tipc_named_rcv(net, &n->bc_entry.namedq);
1569 
1570 	/* If reassembly or retransmission failure => reset all links to peer */
1571 	if (rc & TIPC_LINK_DOWN_EVT)
1572 		tipc_node_reset_links(n);
1573 
1574 	tipc_node_put(n);
1575 }
1576 
1577 /**
1578  * tipc_node_check_state - check and if necessary update node state
1579  * @skb: TIPC packet
1580  * @bearer_id: identity of bearer delivering the packet
1581  * Returns true if state and msg are ok, otherwise false
1582  */
1583 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1584 				  int bearer_id, struct sk_buff_head *xmitq)
1585 {
1586 	struct tipc_msg *hdr = buf_msg(skb);
1587 	int usr = msg_user(hdr);
1588 	int mtyp = msg_type(hdr);
1589 	u16 oseqno = msg_seqno(hdr);
1590 	u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1591 	u16 exp_pkts = msg_msgcnt(hdr);
1592 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1593 	int state = n->state;
1594 	struct tipc_link *l, *tnl, *pl = NULL;
1595 	struct tipc_media_addr *maddr;
1596 	int pb_id;
1597 
1598 	if (trace_tipc_node_check_state_enabled()) {
1599 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1600 		trace_tipc_node_check_state(n, true, " ");
1601 	}
1602 	l = n->links[bearer_id].link;
1603 	if (!l)
1604 		return false;
1605 	rcv_nxt = tipc_link_rcv_nxt(l);
1606 
1607 
1608 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1609 		return true;
1610 
1611 	/* Find parallel link, if any */
1612 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1613 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1614 			pl = n->links[pb_id].link;
1615 			break;
1616 		}
1617 	}
1618 
1619 	if (!tipc_link_validate_msg(l, hdr)) {
1620 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1621 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1622 		return false;
1623 	}
1624 
1625 	/* Check and update node accesibility if applicable */
1626 	if (state == SELF_UP_PEER_COMING) {
1627 		if (!tipc_link_is_up(l))
1628 			return true;
1629 		if (!msg_peer_link_is_up(hdr))
1630 			return true;
1631 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1632 	}
1633 
1634 	if (state == SELF_DOWN_PEER_LEAVING) {
1635 		if (msg_peer_node_is_up(hdr))
1636 			return false;
1637 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1638 		return true;
1639 	}
1640 
1641 	if (state == SELF_LEAVING_PEER_DOWN)
1642 		return false;
1643 
1644 	/* Ignore duplicate packets */
1645 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1646 		return true;
1647 
1648 	/* Initiate or update failover mode if applicable */
1649 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1650 		syncpt = oseqno + exp_pkts - 1;
1651 		if (pl && tipc_link_is_up(pl)) {
1652 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1653 			trace_tipc_node_link_down(n, true,
1654 						  "node link down <- failover!");
1655 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1656 							tipc_link_inputq(l));
1657 		}
1658 		/* If parallel link was already down, and this happened before
1659 		 * the tunnel link came up, FAILOVER was never sent. Ensure that
1660 		 * FAILOVER is sent to get peer out of NODE_FAILINGOVER state.
1661 		 */
1662 		if (n->state != NODE_FAILINGOVER && !n->failover_sent) {
1663 			tipc_link_create_dummy_tnl_msg(l, xmitq);
1664 			n->failover_sent = true;
1665 		}
1666 		/* If pkts arrive out of order, use lowest calculated syncpt */
1667 		if (less(syncpt, n->sync_point))
1668 			n->sync_point = syncpt;
1669 	}
1670 
1671 	/* Open parallel link when tunnel link reaches synch point */
1672 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1673 		if (!more(rcv_nxt, n->sync_point))
1674 			return true;
1675 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1676 		if (pl)
1677 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1678 		return true;
1679 	}
1680 
1681 	/* No synching needed if only one link */
1682 	if (!pl || !tipc_link_is_up(pl))
1683 		return true;
1684 
1685 	/* Initiate synch mode if applicable */
1686 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1687 		syncpt = iseqno + exp_pkts - 1;
1688 		if (!tipc_link_is_up(l))
1689 			__tipc_node_link_up(n, bearer_id, xmitq);
1690 		if (n->state == SELF_UP_PEER_UP) {
1691 			n->sync_point = syncpt;
1692 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1693 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1694 		}
1695 	}
1696 
1697 	/* Open tunnel link when parallel link reaches synch point */
1698 	if (n->state == NODE_SYNCHING) {
1699 		if (tipc_link_is_synching(l)) {
1700 			tnl = l;
1701 		} else {
1702 			tnl = pl;
1703 			pl = l;
1704 		}
1705 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
1706 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1707 		if (more(dlv_nxt, n->sync_point)) {
1708 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1709 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1710 			return true;
1711 		}
1712 		if (l == pl)
1713 			return true;
1714 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1715 			return true;
1716 		if (usr == LINK_PROTOCOL)
1717 			return true;
1718 		return false;
1719 	}
1720 	return true;
1721 }
1722 
1723 /**
1724  * tipc_rcv - process TIPC packets/messages arriving from off-node
1725  * @net: the applicable net namespace
1726  * @skb: TIPC packet
1727  * @bearer: pointer to bearer message arrived on
1728  *
1729  * Invoked with no locks held. Bearer pointer must point to a valid bearer
1730  * structure (i.e. cannot be NULL), but bearer can be inactive.
1731  */
1732 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1733 {
1734 	struct sk_buff_head xmitq;
1735 	struct tipc_node *n;
1736 	struct tipc_msg *hdr;
1737 	int bearer_id = b->identity;
1738 	struct tipc_link_entry *le;
1739 	u32 self = tipc_own_addr(net);
1740 	int usr, rc = 0;
1741 	u16 bc_ack;
1742 
1743 	__skb_queue_head_init(&xmitq);
1744 
1745 	/* Ensure message is well-formed before touching the header */
1746 	if (unlikely(!tipc_msg_validate(&skb)))
1747 		goto discard;
1748 	hdr = buf_msg(skb);
1749 	usr = msg_user(hdr);
1750 	bc_ack = msg_bcast_ack(hdr);
1751 
1752 	/* Handle arrival of discovery or broadcast packet */
1753 	if (unlikely(msg_non_seq(hdr))) {
1754 		if (unlikely(usr == LINK_CONFIG))
1755 			return tipc_disc_rcv(net, skb, b);
1756 		else
1757 			return tipc_node_bc_rcv(net, skb, bearer_id);
1758 	}
1759 
1760 	/* Discard unicast link messages destined for another node */
1761 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
1762 		goto discard;
1763 
1764 	/* Locate neighboring node that sent packet */
1765 	n = tipc_node_find(net, msg_prevnode(hdr));
1766 	if (unlikely(!n))
1767 		goto discard;
1768 	le = &n->links[bearer_id];
1769 
1770 	/* Ensure broadcast reception is in synch with peer's send state */
1771 	if (unlikely(usr == LINK_PROTOCOL))
1772 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
1773 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
1774 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
1775 
1776 	/* Receive packet directly if conditions permit */
1777 	tipc_node_read_lock(n);
1778 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
1779 		spin_lock_bh(&le->lock);
1780 		if (le->link) {
1781 			rc = tipc_link_rcv(le->link, skb, &xmitq);
1782 			skb = NULL;
1783 		}
1784 		spin_unlock_bh(&le->lock);
1785 	}
1786 	tipc_node_read_unlock(n);
1787 
1788 	/* Check/update node state before receiving */
1789 	if (unlikely(skb)) {
1790 		if (unlikely(skb_linearize(skb)))
1791 			goto discard;
1792 		tipc_node_write_lock(n);
1793 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
1794 			if (le->link) {
1795 				rc = tipc_link_rcv(le->link, skb, &xmitq);
1796 				skb = NULL;
1797 			}
1798 		}
1799 		tipc_node_write_unlock(n);
1800 	}
1801 
1802 	if (unlikely(rc & TIPC_LINK_UP_EVT))
1803 		tipc_node_link_up(n, bearer_id, &xmitq);
1804 
1805 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1806 		tipc_node_link_down(n, bearer_id, false);
1807 
1808 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1809 		tipc_named_rcv(net, &n->bc_entry.namedq);
1810 
1811 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
1812 		tipc_node_mcast_rcv(n);
1813 
1814 	if (!skb_queue_empty(&le->inputq))
1815 		tipc_sk_rcv(net, &le->inputq);
1816 
1817 	if (!skb_queue_empty(&xmitq))
1818 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1819 
1820 	tipc_node_put(n);
1821 discard:
1822 	kfree_skb(skb);
1823 }
1824 
1825 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
1826 			      int prop)
1827 {
1828 	struct tipc_net *tn = tipc_net(net);
1829 	int bearer_id = b->identity;
1830 	struct sk_buff_head xmitq;
1831 	struct tipc_link_entry *e;
1832 	struct tipc_node *n;
1833 
1834 	__skb_queue_head_init(&xmitq);
1835 
1836 	rcu_read_lock();
1837 
1838 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1839 		tipc_node_write_lock(n);
1840 		e = &n->links[bearer_id];
1841 		if (e->link) {
1842 			if (prop == TIPC_NLA_PROP_TOL)
1843 				tipc_link_set_tolerance(e->link, b->tolerance,
1844 							&xmitq);
1845 			else if (prop == TIPC_NLA_PROP_MTU)
1846 				tipc_link_set_mtu(e->link, b->mtu);
1847 		}
1848 		tipc_node_write_unlock(n);
1849 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
1850 	}
1851 
1852 	rcu_read_unlock();
1853 }
1854 
1855 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
1856 {
1857 	struct net *net = sock_net(skb->sk);
1858 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1859 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
1860 	struct tipc_node *peer;
1861 	u32 addr;
1862 	int err;
1863 
1864 	/* We identify the peer by its net */
1865 	if (!info->attrs[TIPC_NLA_NET])
1866 		return -EINVAL;
1867 
1868 	err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
1869 			       info->attrs[TIPC_NLA_NET], tipc_nl_net_policy,
1870 			       info->extack);
1871 	if (err)
1872 		return err;
1873 
1874 	if (!attrs[TIPC_NLA_NET_ADDR])
1875 		return -EINVAL;
1876 
1877 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
1878 
1879 	if (in_own_node(net, addr))
1880 		return -ENOTSUPP;
1881 
1882 	spin_lock_bh(&tn->node_list_lock);
1883 	peer = tipc_node_find(net, addr);
1884 	if (!peer) {
1885 		spin_unlock_bh(&tn->node_list_lock);
1886 		return -ENXIO;
1887 	}
1888 
1889 	tipc_node_write_lock(peer);
1890 	if (peer->state != SELF_DOWN_PEER_DOWN &&
1891 	    peer->state != SELF_DOWN_PEER_LEAVING) {
1892 		tipc_node_write_unlock(peer);
1893 		err = -EBUSY;
1894 		goto err_out;
1895 	}
1896 
1897 	tipc_node_clear_links(peer);
1898 	tipc_node_write_unlock(peer);
1899 	tipc_node_delete(peer);
1900 
1901 	err = 0;
1902 err_out:
1903 	tipc_node_put(peer);
1904 	spin_unlock_bh(&tn->node_list_lock);
1905 
1906 	return err;
1907 }
1908 
1909 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1910 {
1911 	int err;
1912 	struct net *net = sock_net(skb->sk);
1913 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1914 	int done = cb->args[0];
1915 	int last_addr = cb->args[1];
1916 	struct tipc_node *node;
1917 	struct tipc_nl_msg msg;
1918 
1919 	if (done)
1920 		return 0;
1921 
1922 	msg.skb = skb;
1923 	msg.portid = NETLINK_CB(cb->skb).portid;
1924 	msg.seq = cb->nlh->nlmsg_seq;
1925 
1926 	rcu_read_lock();
1927 	if (last_addr) {
1928 		node = tipc_node_find(net, last_addr);
1929 		if (!node) {
1930 			rcu_read_unlock();
1931 			/* We never set seq or call nl_dump_check_consistent()
1932 			 * this means that setting prev_seq here will cause the
1933 			 * consistence check to fail in the netlink callback
1934 			 * handler. Resulting in the NLMSG_DONE message having
1935 			 * the NLM_F_DUMP_INTR flag set if the node state
1936 			 * changed while we released the lock.
1937 			 */
1938 			cb->prev_seq = 1;
1939 			return -EPIPE;
1940 		}
1941 		tipc_node_put(node);
1942 	}
1943 
1944 	list_for_each_entry_rcu(node, &tn->node_list, list) {
1945 		if (last_addr) {
1946 			if (node->addr == last_addr)
1947 				last_addr = 0;
1948 			else
1949 				continue;
1950 		}
1951 
1952 		tipc_node_read_lock(node);
1953 		err = __tipc_nl_add_node(&msg, node);
1954 		if (err) {
1955 			last_addr = node->addr;
1956 			tipc_node_read_unlock(node);
1957 			goto out;
1958 		}
1959 
1960 		tipc_node_read_unlock(node);
1961 	}
1962 	done = 1;
1963 out:
1964 	cb->args[0] = done;
1965 	cb->args[1] = last_addr;
1966 	rcu_read_unlock();
1967 
1968 	return skb->len;
1969 }
1970 
1971 /* tipc_node_find_by_name - locate owner node of link by link's name
1972  * @net: the applicable net namespace
1973  * @name: pointer to link name string
1974  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1975  *
1976  * Returns pointer to node owning the link, or 0 if no matching link is found.
1977  */
1978 static struct tipc_node *tipc_node_find_by_name(struct net *net,
1979 						const char *link_name,
1980 						unsigned int *bearer_id)
1981 {
1982 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1983 	struct tipc_link *l;
1984 	struct tipc_node *n;
1985 	struct tipc_node *found_node = NULL;
1986 	int i;
1987 
1988 	*bearer_id = 0;
1989 	rcu_read_lock();
1990 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1991 		tipc_node_read_lock(n);
1992 		for (i = 0; i < MAX_BEARERS; i++) {
1993 			l = n->links[i].link;
1994 			if (l && !strcmp(tipc_link_name(l), link_name)) {
1995 				*bearer_id = i;
1996 				found_node = n;
1997 				break;
1998 			}
1999 		}
2000 		tipc_node_read_unlock(n);
2001 		if (found_node)
2002 			break;
2003 	}
2004 	rcu_read_unlock();
2005 
2006 	return found_node;
2007 }
2008 
2009 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2010 {
2011 	int err;
2012 	int res = 0;
2013 	int bearer_id;
2014 	char *name;
2015 	struct tipc_link *link;
2016 	struct tipc_node *node;
2017 	struct sk_buff_head xmitq;
2018 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2019 	struct net *net = sock_net(skb->sk);
2020 
2021 	__skb_queue_head_init(&xmitq);
2022 
2023 	if (!info->attrs[TIPC_NLA_LINK])
2024 		return -EINVAL;
2025 
2026 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2027 			       info->attrs[TIPC_NLA_LINK],
2028 			       tipc_nl_link_policy, info->extack);
2029 	if (err)
2030 		return err;
2031 
2032 	if (!attrs[TIPC_NLA_LINK_NAME])
2033 		return -EINVAL;
2034 
2035 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2036 
2037 	if (strcmp(name, tipc_bclink_name) == 0)
2038 		return tipc_nl_bc_link_set(net, attrs);
2039 
2040 	node = tipc_node_find_by_name(net, name, &bearer_id);
2041 	if (!node)
2042 		return -EINVAL;
2043 
2044 	tipc_node_read_lock(node);
2045 
2046 	link = node->links[bearer_id].link;
2047 	if (!link) {
2048 		res = -EINVAL;
2049 		goto out;
2050 	}
2051 
2052 	if (attrs[TIPC_NLA_LINK_PROP]) {
2053 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2054 
2055 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2056 					      props);
2057 		if (err) {
2058 			res = err;
2059 			goto out;
2060 		}
2061 
2062 		if (props[TIPC_NLA_PROP_TOL]) {
2063 			u32 tol;
2064 
2065 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2066 			tipc_link_set_tolerance(link, tol, &xmitq);
2067 		}
2068 		if (props[TIPC_NLA_PROP_PRIO]) {
2069 			u32 prio;
2070 
2071 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2072 			tipc_link_set_prio(link, prio, &xmitq);
2073 		}
2074 		if (props[TIPC_NLA_PROP_WIN]) {
2075 			u32 win;
2076 
2077 			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2078 			tipc_link_set_queue_limits(link, win);
2079 		}
2080 	}
2081 
2082 out:
2083 	tipc_node_read_unlock(node);
2084 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
2085 	return res;
2086 }
2087 
2088 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2089 {
2090 	struct net *net = genl_info_net(info);
2091 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2092 	struct tipc_nl_msg msg;
2093 	char *name;
2094 	int err;
2095 
2096 	msg.portid = info->snd_portid;
2097 	msg.seq = info->snd_seq;
2098 
2099 	if (!info->attrs[TIPC_NLA_LINK])
2100 		return -EINVAL;
2101 
2102 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2103 			       info->attrs[TIPC_NLA_LINK],
2104 			       tipc_nl_link_policy, info->extack);
2105 	if (err)
2106 		return err;
2107 
2108 	if (!attrs[TIPC_NLA_LINK_NAME])
2109 		return -EINVAL;
2110 
2111 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2112 
2113 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2114 	if (!msg.skb)
2115 		return -ENOMEM;
2116 
2117 	if (strcmp(name, tipc_bclink_name) == 0) {
2118 		err = tipc_nl_add_bc_link(net, &msg);
2119 		if (err)
2120 			goto err_free;
2121 	} else {
2122 		int bearer_id;
2123 		struct tipc_node *node;
2124 		struct tipc_link *link;
2125 
2126 		node = tipc_node_find_by_name(net, name, &bearer_id);
2127 		if (!node) {
2128 			err = -EINVAL;
2129 			goto err_free;
2130 		}
2131 
2132 		tipc_node_read_lock(node);
2133 		link = node->links[bearer_id].link;
2134 		if (!link) {
2135 			tipc_node_read_unlock(node);
2136 			err = -EINVAL;
2137 			goto err_free;
2138 		}
2139 
2140 		err = __tipc_nl_add_link(net, &msg, link, 0);
2141 		tipc_node_read_unlock(node);
2142 		if (err)
2143 			goto err_free;
2144 	}
2145 
2146 	return genlmsg_reply(msg.skb, info);
2147 
2148 err_free:
2149 	nlmsg_free(msg.skb);
2150 	return err;
2151 }
2152 
2153 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2154 {
2155 	int err;
2156 	char *link_name;
2157 	unsigned int bearer_id;
2158 	struct tipc_link *link;
2159 	struct tipc_node *node;
2160 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2161 	struct net *net = sock_net(skb->sk);
2162 	struct tipc_link_entry *le;
2163 
2164 	if (!info->attrs[TIPC_NLA_LINK])
2165 		return -EINVAL;
2166 
2167 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2168 			       info->attrs[TIPC_NLA_LINK],
2169 			       tipc_nl_link_policy, info->extack);
2170 	if (err)
2171 		return err;
2172 
2173 	if (!attrs[TIPC_NLA_LINK_NAME])
2174 		return -EINVAL;
2175 
2176 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2177 
2178 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2179 		err = tipc_bclink_reset_stats(net);
2180 		if (err)
2181 			return err;
2182 		return 0;
2183 	}
2184 
2185 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2186 	if (!node)
2187 		return -EINVAL;
2188 
2189 	le = &node->links[bearer_id];
2190 	tipc_node_read_lock(node);
2191 	spin_lock_bh(&le->lock);
2192 	link = node->links[bearer_id].link;
2193 	if (!link) {
2194 		spin_unlock_bh(&le->lock);
2195 		tipc_node_read_unlock(node);
2196 		return -EINVAL;
2197 	}
2198 	tipc_link_reset_stats(link);
2199 	spin_unlock_bh(&le->lock);
2200 	tipc_node_read_unlock(node);
2201 	return 0;
2202 }
2203 
2204 /* Caller should hold node lock  */
2205 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2206 				    struct tipc_node *node, u32 *prev_link)
2207 {
2208 	u32 i;
2209 	int err;
2210 
2211 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2212 		*prev_link = i;
2213 
2214 		if (!node->links[i].link)
2215 			continue;
2216 
2217 		err = __tipc_nl_add_link(net, msg,
2218 					 node->links[i].link, NLM_F_MULTI);
2219 		if (err)
2220 			return err;
2221 	}
2222 	*prev_link = 0;
2223 
2224 	return 0;
2225 }
2226 
2227 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2228 {
2229 	struct net *net = sock_net(skb->sk);
2230 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2231 	struct tipc_node *node;
2232 	struct tipc_nl_msg msg;
2233 	u32 prev_node = cb->args[0];
2234 	u32 prev_link = cb->args[1];
2235 	int done = cb->args[2];
2236 	int err;
2237 
2238 	if (done)
2239 		return 0;
2240 
2241 	msg.skb = skb;
2242 	msg.portid = NETLINK_CB(cb->skb).portid;
2243 	msg.seq = cb->nlh->nlmsg_seq;
2244 
2245 	rcu_read_lock();
2246 	if (prev_node) {
2247 		node = tipc_node_find(net, prev_node);
2248 		if (!node) {
2249 			/* We never set seq or call nl_dump_check_consistent()
2250 			 * this means that setting prev_seq here will cause the
2251 			 * consistence check to fail in the netlink callback
2252 			 * handler. Resulting in the last NLMSG_DONE message
2253 			 * having the NLM_F_DUMP_INTR flag set.
2254 			 */
2255 			cb->prev_seq = 1;
2256 			goto out;
2257 		}
2258 		tipc_node_put(node);
2259 
2260 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2261 						 list) {
2262 			tipc_node_read_lock(node);
2263 			err = __tipc_nl_add_node_links(net, &msg, node,
2264 						       &prev_link);
2265 			tipc_node_read_unlock(node);
2266 			if (err)
2267 				goto out;
2268 
2269 			prev_node = node->addr;
2270 		}
2271 	} else {
2272 		err = tipc_nl_add_bc_link(net, &msg);
2273 		if (err)
2274 			goto out;
2275 
2276 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2277 			tipc_node_read_lock(node);
2278 			err = __tipc_nl_add_node_links(net, &msg, node,
2279 						       &prev_link);
2280 			tipc_node_read_unlock(node);
2281 			if (err)
2282 				goto out;
2283 
2284 			prev_node = node->addr;
2285 		}
2286 	}
2287 	done = 1;
2288 out:
2289 	rcu_read_unlock();
2290 
2291 	cb->args[0] = prev_node;
2292 	cb->args[1] = prev_link;
2293 	cb->args[2] = done;
2294 
2295 	return skb->len;
2296 }
2297 
2298 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2299 {
2300 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2301 	struct net *net = sock_net(skb->sk);
2302 	int err;
2303 
2304 	if (!info->attrs[TIPC_NLA_MON])
2305 		return -EINVAL;
2306 
2307 	err = nla_parse_nested(attrs, TIPC_NLA_MON_MAX,
2308 			       info->attrs[TIPC_NLA_MON],
2309 			       tipc_nl_monitor_policy, info->extack);
2310 	if (err)
2311 		return err;
2312 
2313 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2314 		u32 val;
2315 
2316 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2317 		err = tipc_nl_monitor_set_threshold(net, val);
2318 		if (err)
2319 			return err;
2320 	}
2321 
2322 	return 0;
2323 }
2324 
2325 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2326 {
2327 	struct nlattr *attrs;
2328 	void *hdr;
2329 	u32 val;
2330 
2331 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2332 			  0, TIPC_NL_MON_GET);
2333 	if (!hdr)
2334 		return -EMSGSIZE;
2335 
2336 	attrs = nla_nest_start(msg->skb, TIPC_NLA_MON);
2337 	if (!attrs)
2338 		goto msg_full;
2339 
2340 	val = tipc_nl_monitor_get_threshold(net);
2341 
2342 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2343 		goto attr_msg_full;
2344 
2345 	nla_nest_end(msg->skb, attrs);
2346 	genlmsg_end(msg->skb, hdr);
2347 
2348 	return 0;
2349 
2350 attr_msg_full:
2351 	nla_nest_cancel(msg->skb, attrs);
2352 msg_full:
2353 	genlmsg_cancel(msg->skb, hdr);
2354 
2355 	return -EMSGSIZE;
2356 }
2357 
2358 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2359 {
2360 	struct net *net = sock_net(skb->sk);
2361 	struct tipc_nl_msg msg;
2362 	int err;
2363 
2364 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2365 	if (!msg.skb)
2366 		return -ENOMEM;
2367 	msg.portid = info->snd_portid;
2368 	msg.seq = info->snd_seq;
2369 
2370 	err = __tipc_nl_add_monitor_prop(net, &msg);
2371 	if (err) {
2372 		nlmsg_free(msg.skb);
2373 		return err;
2374 	}
2375 
2376 	return genlmsg_reply(msg.skb, info);
2377 }
2378 
2379 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2380 {
2381 	struct net *net = sock_net(skb->sk);
2382 	u32 prev_bearer = cb->args[0];
2383 	struct tipc_nl_msg msg;
2384 	int bearer_id;
2385 	int err;
2386 
2387 	if (prev_bearer == MAX_BEARERS)
2388 		return 0;
2389 
2390 	msg.skb = skb;
2391 	msg.portid = NETLINK_CB(cb->skb).portid;
2392 	msg.seq = cb->nlh->nlmsg_seq;
2393 
2394 	rtnl_lock();
2395 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2396 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2397 		if (err)
2398 			break;
2399 	}
2400 	rtnl_unlock();
2401 	cb->args[0] = bearer_id;
2402 
2403 	return skb->len;
2404 }
2405 
2406 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2407 				   struct netlink_callback *cb)
2408 {
2409 	struct net *net = sock_net(skb->sk);
2410 	u32 prev_node = cb->args[1];
2411 	u32 bearer_id = cb->args[2];
2412 	int done = cb->args[0];
2413 	struct tipc_nl_msg msg;
2414 	int err;
2415 
2416 	if (!prev_node) {
2417 		struct nlattr **attrs;
2418 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2419 
2420 		err = tipc_nlmsg_parse(cb->nlh, &attrs);
2421 		if (err)
2422 			return err;
2423 
2424 		if (!attrs[TIPC_NLA_MON])
2425 			return -EINVAL;
2426 
2427 		err = nla_parse_nested(mon, TIPC_NLA_MON_MAX,
2428 				       attrs[TIPC_NLA_MON],
2429 				       tipc_nl_monitor_policy, NULL);
2430 		if (err)
2431 			return err;
2432 
2433 		if (!mon[TIPC_NLA_MON_REF])
2434 			return -EINVAL;
2435 
2436 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2437 
2438 		if (bearer_id >= MAX_BEARERS)
2439 			return -EINVAL;
2440 	}
2441 
2442 	if (done)
2443 		return 0;
2444 
2445 	msg.skb = skb;
2446 	msg.portid = NETLINK_CB(cb->skb).portid;
2447 	msg.seq = cb->nlh->nlmsg_seq;
2448 
2449 	rtnl_lock();
2450 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2451 	if (!err)
2452 		done = 1;
2453 
2454 	rtnl_unlock();
2455 	cb->args[0] = done;
2456 	cb->args[1] = prev_node;
2457 	cb->args[2] = bearer_id;
2458 
2459 	return skb->len;
2460 }
2461 
2462 u32 tipc_node_get_addr(struct tipc_node *node)
2463 {
2464 	return (node) ? node->addr : 0;
2465 }
2466 
2467 /**
2468  * tipc_node_dump - dump TIPC node data
2469  * @n: tipc node to be dumped
2470  * @more: dump more?
2471  *        - false: dump only tipc node data
2472  *        - true: dump node link data as well
2473  * @buf: returned buffer of dump data in format
2474  */
2475 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2476 {
2477 	int i = 0;
2478 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2479 
2480 	if (!n) {
2481 		i += scnprintf(buf, sz, "node data: (null)\n");
2482 		return i;
2483 	}
2484 
2485 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2486 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2487 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2488 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2489 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
2490 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
2491 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
2492 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
2493 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
2494 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
2495 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
2496 
2497 	if (!more)
2498 		return i;
2499 
2500 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
2501 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
2502 	i += scnprintf(buf + i, sz - i, " media: ");
2503 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
2504 	i += scnprintf(buf + i, sz - i, "\n");
2505 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
2506 	i += scnprintf(buf + i, sz - i, " inputq: ");
2507 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
2508 
2509 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
2510 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
2511 	i += scnprintf(buf + i, sz - i, " media: ");
2512 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
2513 	i += scnprintf(buf + i, sz - i, "\n");
2514 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
2515 	i += scnprintf(buf + i, sz - i, " inputq: ");
2516 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
2517 
2518 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
2519 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
2520 
2521 	return i;
2522 }
2523