xref: /linux/net/tipc/node.c (revision d6a5c562214f26e442c8ec3ff1e28e16675d1bcf)
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, 2012-2016, Ericsson AB
5  * Copyright (c) 2005-2006, 2010-2014, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "core.h"
38 #include "link.h"
39 #include "node.h"
40 #include "name_distr.h"
41 #include "socket.h"
42 #include "bcast.h"
43 #include "monitor.h"
44 #include "discover.h"
45 #include "netlink.h"
46 #include "trace.h"
47 #include "crypto.h"
48 
49 #define INVALID_NODE_SIG	0x10000
50 #define NODE_CLEANUP_AFTER	300000
51 
52 /* Flags used to take different actions according to flag type
53  * TIPC_NOTIFY_NODE_DOWN: notify node is down
54  * TIPC_NOTIFY_NODE_UP: notify node is up
55  * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
56  */
57 enum {
58 	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
59 	TIPC_NOTIFY_NODE_UP		= (1 << 4),
60 	TIPC_NOTIFY_LINK_UP		= (1 << 6),
61 	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
62 };
63 
64 struct tipc_link_entry {
65 	struct tipc_link *link;
66 	spinlock_t lock; /* per link */
67 	u32 mtu;
68 	struct sk_buff_head inputq;
69 	struct tipc_media_addr maddr;
70 };
71 
72 struct tipc_bclink_entry {
73 	struct tipc_link *link;
74 	struct sk_buff_head inputq1;
75 	struct sk_buff_head arrvq;
76 	struct sk_buff_head inputq2;
77 	struct sk_buff_head namedq;
78 	u16 named_rcv_nxt;
79 	bool named_open;
80 };
81 
82 /**
83  * struct tipc_node - TIPC node structure
84  * @addr: network address of node
85  * @kref: reference counter to node object
86  * @lock: rwlock governing access to structure
87  * @net: the applicable net namespace
88  * @hash: links to adjacent nodes in unsorted hash chain
89  * @inputq: pointer to input queue containing messages for msg event
90  * @namedq: pointer to name table input queue with name table messages
91  * @active_links: bearer ids of active links, used as index into links[] array
92  * @links: array containing references to all links to node
93  * @bc_entry: broadcast link entry
94  * @action_flags: bit mask of different types of node actions
95  * @state: connectivity state vs peer node
96  * @preliminary: a preliminary node or not
97  * @failover_sent: failover sent or not
98  * @sync_point: sequence number where synch/failover is finished
99  * @list: links to adjacent nodes in sorted list of cluster's nodes
100  * @working_links: number of working links to node (both active and standby)
101  * @link_cnt: number of links to node
102  * @capabilities: bitmap, indicating peer node's functional capabilities
103  * @signature: node instance identifier
104  * @link_id: local and remote bearer ids of changing link, if any
105  * @peer_id: 128-bit ID of peer
106  * @peer_id_string: ID string of peer
107  * @publ_list: list of publications
108  * @conn_sks: list of connections (FIXME)
109  * @timer: node's keepalive timer
110  * @keepalive_intv: keepalive interval in milliseconds
111  * @rcu: rcu struct for tipc_node
112  * @delete_at: indicates the time for deleting a down node
113  * @peer_net: peer's net namespace
114  * @peer_hash_mix: hash for this peer (FIXME)
115  * @crypto_rx: RX crypto handler
116  */
117 struct tipc_node {
118 	u32 addr;
119 	struct kref kref;
120 	rwlock_t lock;
121 	struct net *net;
122 	struct hlist_node hash;
123 	int active_links[2];
124 	struct tipc_link_entry links[MAX_BEARERS];
125 	struct tipc_bclink_entry bc_entry;
126 	int action_flags;
127 	struct list_head list;
128 	int state;
129 	bool preliminary;
130 	bool failover_sent;
131 	u16 sync_point;
132 	int link_cnt;
133 	u16 working_links;
134 	u16 capabilities;
135 	u32 signature;
136 	u32 link_id;
137 	u8 peer_id[16];
138 	char peer_id_string[NODE_ID_STR_LEN];
139 	struct list_head publ_list;
140 	struct list_head conn_sks;
141 	unsigned long keepalive_intv;
142 	struct timer_list timer;
143 	struct rcu_head rcu;
144 	unsigned long delete_at;
145 	struct net *peer_net;
146 	u32 peer_hash_mix;
147 #ifdef CONFIG_TIPC_CRYPTO
148 	struct tipc_crypto *crypto_rx;
149 #endif
150 };
151 
152 /* Node FSM states and events:
153  */
154 enum {
155 	SELF_DOWN_PEER_DOWN    = 0xdd,
156 	SELF_UP_PEER_UP        = 0xaa,
157 	SELF_DOWN_PEER_LEAVING = 0xd1,
158 	SELF_UP_PEER_COMING    = 0xac,
159 	SELF_COMING_PEER_UP    = 0xca,
160 	SELF_LEAVING_PEER_DOWN = 0x1d,
161 	NODE_FAILINGOVER       = 0xf0,
162 	NODE_SYNCHING          = 0xcc
163 };
164 
165 enum {
166 	SELF_ESTABL_CONTACT_EVT = 0xece,
167 	SELF_LOST_CONTACT_EVT   = 0x1ce,
168 	PEER_ESTABL_CONTACT_EVT = 0x9ece,
169 	PEER_LOST_CONTACT_EVT   = 0x91ce,
170 	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
171 	NODE_FAILOVER_END_EVT   = 0xfee,
172 	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
173 	NODE_SYNCH_END_EVT      = 0xcee
174 };
175 
176 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
177 				  struct sk_buff_head *xmitq,
178 				  struct tipc_media_addr **maddr);
179 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
180 				bool delete);
181 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
182 static void tipc_node_delete(struct tipc_node *node);
183 static void tipc_node_timeout(struct timer_list *t);
184 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
185 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
186 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
187 static bool node_is_up(struct tipc_node *n);
188 static void tipc_node_delete_from_list(struct tipc_node *node);
189 
190 struct tipc_sock_conn {
191 	u32 port;
192 	u32 peer_port;
193 	u32 peer_node;
194 	struct list_head list;
195 };
196 
197 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
198 {
199 	int bearer_id = n->active_links[sel & 1];
200 
201 	if (unlikely(bearer_id == INVALID_BEARER_ID))
202 		return NULL;
203 
204 	return n->links[bearer_id].link;
205 }
206 
207 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel, bool connected)
208 {
209 	struct tipc_node *n;
210 	int bearer_id;
211 	unsigned int mtu = MAX_MSG_SIZE;
212 
213 	n = tipc_node_find(net, addr);
214 	if (unlikely(!n))
215 		return mtu;
216 
217 	/* Allow MAX_MSG_SIZE when building connection oriented message
218 	 * if they are in the same core network
219 	 */
220 	if (n->peer_net && connected) {
221 		tipc_node_put(n);
222 		return mtu;
223 	}
224 
225 	bearer_id = n->active_links[sel & 1];
226 	if (likely(bearer_id != INVALID_BEARER_ID))
227 		mtu = n->links[bearer_id].mtu;
228 	tipc_node_put(n);
229 	return mtu;
230 }
231 
232 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
233 {
234 	u8 *own_id = tipc_own_id(net);
235 	struct tipc_node *n;
236 
237 	if (!own_id)
238 		return true;
239 
240 	if (addr == tipc_own_addr(net)) {
241 		memcpy(id, own_id, TIPC_NODEID_LEN);
242 		return true;
243 	}
244 	n = tipc_node_find(net, addr);
245 	if (!n)
246 		return false;
247 
248 	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
249 	tipc_node_put(n);
250 	return true;
251 }
252 
253 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
254 {
255 	struct tipc_node *n;
256 	u16 caps;
257 
258 	n = tipc_node_find(net, addr);
259 	if (unlikely(!n))
260 		return TIPC_NODE_CAPABILITIES;
261 	caps = n->capabilities;
262 	tipc_node_put(n);
263 	return caps;
264 }
265 
266 u32 tipc_node_get_addr(struct tipc_node *node)
267 {
268 	return (node) ? node->addr : 0;
269 }
270 
271 char *tipc_node_get_id_str(struct tipc_node *node)
272 {
273 	return node->peer_id_string;
274 }
275 
276 #ifdef CONFIG_TIPC_CRYPTO
277 /**
278  * tipc_node_crypto_rx - Retrieve crypto RX handle from node
279  * @__n: target tipc_node
280  * Note: node ref counter must be held first!
281  */
282 struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n)
283 {
284 	return (__n) ? __n->crypto_rx : NULL;
285 }
286 
287 struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos)
288 {
289 	return container_of(pos, struct tipc_node, list)->crypto_rx;
290 }
291 
292 struct tipc_crypto *tipc_node_crypto_rx_by_addr(struct net *net, u32 addr)
293 {
294 	struct tipc_node *n;
295 
296 	n = tipc_node_find(net, addr);
297 	return (n) ? n->crypto_rx : NULL;
298 }
299 #endif
300 
301 static void tipc_node_free(struct rcu_head *rp)
302 {
303 	struct tipc_node *n = container_of(rp, struct tipc_node, rcu);
304 
305 #ifdef CONFIG_TIPC_CRYPTO
306 	tipc_crypto_stop(&n->crypto_rx);
307 #endif
308 	kfree(n);
309 }
310 
311 static void tipc_node_kref_release(struct kref *kref)
312 {
313 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
314 
315 	kfree(n->bc_entry.link);
316 	call_rcu(&n->rcu, tipc_node_free);
317 }
318 
319 void tipc_node_put(struct tipc_node *node)
320 {
321 	kref_put(&node->kref, tipc_node_kref_release);
322 }
323 
324 void tipc_node_get(struct tipc_node *node)
325 {
326 	kref_get(&node->kref);
327 }
328 
329 /*
330  * tipc_node_find - locate specified node object, if it exists
331  */
332 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
333 {
334 	struct tipc_net *tn = tipc_net(net);
335 	struct tipc_node *node;
336 	unsigned int thash = tipc_hashfn(addr);
337 
338 	rcu_read_lock();
339 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
340 		if (node->addr != addr || node->preliminary)
341 			continue;
342 		if (!kref_get_unless_zero(&node->kref))
343 			node = NULL;
344 		break;
345 	}
346 	rcu_read_unlock();
347 	return node;
348 }
349 
350 /* tipc_node_find_by_id - locate specified node object by its 128-bit id
351  * Note: this function is called only when a discovery request failed
352  * to find the node by its 32-bit id, and is not time critical
353  */
354 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
355 {
356 	struct tipc_net *tn = tipc_net(net);
357 	struct tipc_node *n;
358 	bool found = false;
359 
360 	rcu_read_lock();
361 	list_for_each_entry_rcu(n, &tn->node_list, list) {
362 		read_lock_bh(&n->lock);
363 		if (!memcmp(id, n->peer_id, 16) &&
364 		    kref_get_unless_zero(&n->kref))
365 			found = true;
366 		read_unlock_bh(&n->lock);
367 		if (found)
368 			break;
369 	}
370 	rcu_read_unlock();
371 	return found ? n : NULL;
372 }
373 
374 static void tipc_node_read_lock(struct tipc_node *n)
375 	__acquires(n->lock)
376 {
377 	read_lock_bh(&n->lock);
378 }
379 
380 static void tipc_node_read_unlock(struct tipc_node *n)
381 	__releases(n->lock)
382 {
383 	read_unlock_bh(&n->lock);
384 }
385 
386 static void tipc_node_write_lock(struct tipc_node *n)
387 	__acquires(n->lock)
388 {
389 	write_lock_bh(&n->lock);
390 }
391 
392 static void tipc_node_write_unlock_fast(struct tipc_node *n)
393 	__releases(n->lock)
394 {
395 	write_unlock_bh(&n->lock);
396 }
397 
398 static void tipc_node_write_unlock(struct tipc_node *n)
399 	__releases(n->lock)
400 {
401 	struct tipc_socket_addr sk;
402 	struct net *net = n->net;
403 	u32 flags = n->action_flags;
404 	struct list_head *publ_list;
405 	struct tipc_uaddr ua;
406 	u32 bearer_id, node;
407 
408 	if (likely(!flags)) {
409 		write_unlock_bh(&n->lock);
410 		return;
411 	}
412 
413 	tipc_uaddr(&ua, TIPC_SERVICE_RANGE, TIPC_NODE_SCOPE,
414 		   TIPC_LINK_STATE, n->addr, n->addr);
415 	sk.ref = n->link_id;
416 	sk.node = tipc_own_addr(net);
417 	node = n->addr;
418 	bearer_id = n->link_id & 0xffff;
419 	publ_list = &n->publ_list;
420 
421 	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
422 			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
423 
424 	write_unlock_bh(&n->lock);
425 
426 	if (flags & TIPC_NOTIFY_NODE_DOWN)
427 		tipc_publ_notify(net, publ_list, node, n->capabilities);
428 
429 	if (flags & TIPC_NOTIFY_NODE_UP)
430 		tipc_named_node_up(net, node, n->capabilities);
431 
432 	if (flags & TIPC_NOTIFY_LINK_UP) {
433 		tipc_mon_peer_up(net, node, bearer_id);
434 		tipc_nametbl_publish(net, &ua, &sk, sk.ref);
435 	}
436 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
437 		tipc_mon_peer_down(net, node, bearer_id);
438 		tipc_nametbl_withdraw(net, &ua, &sk, sk.ref);
439 	}
440 }
441 
442 static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
443 {
444 	int net_id = tipc_netid(n->net);
445 	struct tipc_net *tn_peer;
446 	struct net *tmp;
447 	u32 hash_chk;
448 
449 	if (n->peer_net)
450 		return;
451 
452 	for_each_net_rcu(tmp) {
453 		tn_peer = tipc_net(tmp);
454 		if (!tn_peer)
455 			continue;
456 		/* Integrity checking whether node exists in namespace or not */
457 		if (tn_peer->net_id != net_id)
458 			continue;
459 		if (memcmp(n->peer_id, tn_peer->node_id, NODE_ID_LEN))
460 			continue;
461 		hash_chk = tipc_net_hash_mixes(tmp, tn_peer->random);
462 		if (hash_mixes ^ hash_chk)
463 			continue;
464 		n->peer_net = tmp;
465 		n->peer_hash_mix = hash_mixes;
466 		break;
467 	}
468 }
469 
470 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
471 				   u16 capabilities, u32 hash_mixes,
472 				   bool preliminary)
473 {
474 	struct tipc_net *tn = net_generic(net, tipc_net_id);
475 	struct tipc_link *l, *snd_l = tipc_bc_sndlink(net);
476 	struct tipc_node *n, *temp_node;
477 	unsigned long intv;
478 	int bearer_id;
479 	int i;
480 
481 	spin_lock_bh(&tn->node_list_lock);
482 	n = tipc_node_find(net, addr) ?:
483 		tipc_node_find_by_id(net, peer_id);
484 	if (n) {
485 		if (!n->preliminary)
486 			goto update;
487 		if (preliminary)
488 			goto exit;
489 		/* A preliminary node becomes "real" now, refresh its data */
490 		tipc_node_write_lock(n);
491 		if (!tipc_link_bc_create(net, tipc_own_addr(net), addr, peer_id, U16_MAX,
492 					 tipc_link_min_win(snd_l), tipc_link_max_win(snd_l),
493 					 n->capabilities, &n->bc_entry.inputq1,
494 					 &n->bc_entry.namedq, snd_l, &n->bc_entry.link)) {
495 			pr_warn("Broadcast rcv link refresh failed, no memory\n");
496 			tipc_node_write_unlock_fast(n);
497 			tipc_node_put(n);
498 			n = NULL;
499 			goto exit;
500 		}
501 		n->preliminary = false;
502 		n->addr = addr;
503 		hlist_del_rcu(&n->hash);
504 		hlist_add_head_rcu(&n->hash,
505 				   &tn->node_htable[tipc_hashfn(addr)]);
506 		list_del_rcu(&n->list);
507 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
508 			if (n->addr < temp_node->addr)
509 				break;
510 		}
511 		list_add_tail_rcu(&n->list, &temp_node->list);
512 		tipc_node_write_unlock_fast(n);
513 
514 update:
515 		if (n->peer_hash_mix ^ hash_mixes)
516 			tipc_node_assign_peer_net(n, hash_mixes);
517 		if (n->capabilities == capabilities)
518 			goto exit;
519 		/* Same node may come back with new capabilities */
520 		tipc_node_write_lock(n);
521 		n->capabilities = capabilities;
522 		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
523 			l = n->links[bearer_id].link;
524 			if (l)
525 				tipc_link_update_caps(l, capabilities);
526 		}
527 		tipc_node_write_unlock_fast(n);
528 
529 		/* Calculate cluster capabilities */
530 		tn->capabilities = TIPC_NODE_CAPABILITIES;
531 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
532 			tn->capabilities &= temp_node->capabilities;
533 		}
534 
535 		tipc_bcast_toggle_rcast(net,
536 					(tn->capabilities & TIPC_BCAST_RCAST));
537 
538 		goto exit;
539 	}
540 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
541 	if (!n) {
542 		pr_warn("Node creation failed, no memory\n");
543 		goto exit;
544 	}
545 	tipc_nodeid2string(n->peer_id_string, peer_id);
546 #ifdef CONFIG_TIPC_CRYPTO
547 	if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
548 		pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
549 		kfree(n);
550 		n = NULL;
551 		goto exit;
552 	}
553 #endif
554 	n->addr = addr;
555 	n->preliminary = preliminary;
556 	memcpy(&n->peer_id, peer_id, 16);
557 	n->net = net;
558 	n->peer_net = NULL;
559 	n->peer_hash_mix = 0;
560 	/* Assign kernel local namespace if exists */
561 	tipc_node_assign_peer_net(n, hash_mixes);
562 	n->capabilities = capabilities;
563 	kref_init(&n->kref);
564 	rwlock_init(&n->lock);
565 	INIT_HLIST_NODE(&n->hash);
566 	INIT_LIST_HEAD(&n->list);
567 	INIT_LIST_HEAD(&n->publ_list);
568 	INIT_LIST_HEAD(&n->conn_sks);
569 	skb_queue_head_init(&n->bc_entry.namedq);
570 	skb_queue_head_init(&n->bc_entry.inputq1);
571 	__skb_queue_head_init(&n->bc_entry.arrvq);
572 	skb_queue_head_init(&n->bc_entry.inputq2);
573 	for (i = 0; i < MAX_BEARERS; i++)
574 		spin_lock_init(&n->links[i].lock);
575 	n->state = SELF_DOWN_PEER_LEAVING;
576 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
577 	n->signature = INVALID_NODE_SIG;
578 	n->active_links[0] = INVALID_BEARER_ID;
579 	n->active_links[1] = INVALID_BEARER_ID;
580 	if (!preliminary &&
581 	    !tipc_link_bc_create(net, tipc_own_addr(net), addr, peer_id, U16_MAX,
582 				 tipc_link_min_win(snd_l), tipc_link_max_win(snd_l),
583 				 n->capabilities, &n->bc_entry.inputq1,
584 				 &n->bc_entry.namedq, snd_l, &n->bc_entry.link)) {
585 		pr_warn("Broadcast rcv link creation failed, no memory\n");
586 		kfree(n);
587 		n = NULL;
588 		goto exit;
589 	}
590 	tipc_node_get(n);
591 	timer_setup(&n->timer, tipc_node_timeout, 0);
592 	/* Start a slow timer anyway, crypto needs it */
593 	n->keepalive_intv = 10000;
594 	intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
595 	if (!mod_timer(&n->timer, intv))
596 		tipc_node_get(n);
597 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
598 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
599 		if (n->addr < temp_node->addr)
600 			break;
601 	}
602 	list_add_tail_rcu(&n->list, &temp_node->list);
603 	/* Calculate cluster capabilities */
604 	tn->capabilities = TIPC_NODE_CAPABILITIES;
605 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
606 		tn->capabilities &= temp_node->capabilities;
607 	}
608 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
609 	trace_tipc_node_create(n, true, " ");
610 exit:
611 	spin_unlock_bh(&tn->node_list_lock);
612 	return n;
613 }
614 
615 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
616 {
617 	unsigned long tol = tipc_link_tolerance(l);
618 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
619 
620 	/* Link with lowest tolerance determines timer interval */
621 	if (intv < n->keepalive_intv)
622 		n->keepalive_intv = intv;
623 
624 	/* Ensure link's abort limit corresponds to current tolerance */
625 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
626 }
627 
628 static void tipc_node_delete_from_list(struct tipc_node *node)
629 {
630 #ifdef CONFIG_TIPC_CRYPTO
631 	tipc_crypto_key_flush(node->crypto_rx);
632 #endif
633 	list_del_rcu(&node->list);
634 	hlist_del_rcu(&node->hash);
635 	tipc_node_put(node);
636 }
637 
638 static void tipc_node_delete(struct tipc_node *node)
639 {
640 	trace_tipc_node_delete(node, true, " ");
641 	tipc_node_delete_from_list(node);
642 
643 	del_timer_sync(&node->timer);
644 	tipc_node_put(node);
645 }
646 
647 void tipc_node_stop(struct net *net)
648 {
649 	struct tipc_net *tn = tipc_net(net);
650 	struct tipc_node *node, *t_node;
651 
652 	spin_lock_bh(&tn->node_list_lock);
653 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
654 		tipc_node_delete(node);
655 	spin_unlock_bh(&tn->node_list_lock);
656 }
657 
658 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
659 {
660 	struct tipc_node *n;
661 
662 	if (in_own_node(net, addr))
663 		return;
664 
665 	n = tipc_node_find(net, addr);
666 	if (!n) {
667 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
668 		return;
669 	}
670 	tipc_node_write_lock(n);
671 	list_add_tail(subscr, &n->publ_list);
672 	tipc_node_write_unlock_fast(n);
673 	tipc_node_put(n);
674 }
675 
676 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
677 {
678 	struct tipc_node *n;
679 
680 	if (in_own_node(net, addr))
681 		return;
682 
683 	n = tipc_node_find(net, addr);
684 	if (!n) {
685 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
686 		return;
687 	}
688 	tipc_node_write_lock(n);
689 	list_del_init(subscr);
690 	tipc_node_write_unlock_fast(n);
691 	tipc_node_put(n);
692 }
693 
694 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
695 {
696 	struct tipc_node *node;
697 	struct tipc_sock_conn *conn;
698 	int err = 0;
699 
700 	if (in_own_node(net, dnode))
701 		return 0;
702 
703 	node = tipc_node_find(net, dnode);
704 	if (!node) {
705 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
706 		return -EHOSTUNREACH;
707 	}
708 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
709 	if (!conn) {
710 		err = -EHOSTUNREACH;
711 		goto exit;
712 	}
713 	conn->peer_node = dnode;
714 	conn->port = port;
715 	conn->peer_port = peer_port;
716 
717 	tipc_node_write_lock(node);
718 	list_add_tail(&conn->list, &node->conn_sks);
719 	tipc_node_write_unlock(node);
720 exit:
721 	tipc_node_put(node);
722 	return err;
723 }
724 
725 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
726 {
727 	struct tipc_node *node;
728 	struct tipc_sock_conn *conn, *safe;
729 
730 	if (in_own_node(net, dnode))
731 		return;
732 
733 	node = tipc_node_find(net, dnode);
734 	if (!node)
735 		return;
736 
737 	tipc_node_write_lock(node);
738 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
739 		if (port != conn->port)
740 			continue;
741 		list_del(&conn->list);
742 		kfree(conn);
743 	}
744 	tipc_node_write_unlock(node);
745 	tipc_node_put(node);
746 }
747 
748 static void  tipc_node_clear_links(struct tipc_node *node)
749 {
750 	int i;
751 
752 	for (i = 0; i < MAX_BEARERS; i++) {
753 		struct tipc_link_entry *le = &node->links[i];
754 
755 		if (le->link) {
756 			kfree(le->link);
757 			le->link = NULL;
758 			node->link_cnt--;
759 		}
760 	}
761 }
762 
763 /* tipc_node_cleanup - delete nodes that does not
764  * have active links for NODE_CLEANUP_AFTER time
765  */
766 static bool tipc_node_cleanup(struct tipc_node *peer)
767 {
768 	struct tipc_node *temp_node;
769 	struct tipc_net *tn = tipc_net(peer->net);
770 	bool deleted = false;
771 
772 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
773 	if (!spin_trylock_bh(&tn->node_list_lock))
774 		return false;
775 
776 	tipc_node_write_lock(peer);
777 
778 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
779 		tipc_node_clear_links(peer);
780 		tipc_node_delete_from_list(peer);
781 		deleted = true;
782 	}
783 	tipc_node_write_unlock(peer);
784 
785 	if (!deleted) {
786 		spin_unlock_bh(&tn->node_list_lock);
787 		return deleted;
788 	}
789 
790 	/* Calculate cluster capabilities */
791 	tn->capabilities = TIPC_NODE_CAPABILITIES;
792 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
793 		tn->capabilities &= temp_node->capabilities;
794 	}
795 	tipc_bcast_toggle_rcast(peer->net,
796 				(tn->capabilities & TIPC_BCAST_RCAST));
797 	spin_unlock_bh(&tn->node_list_lock);
798 	return deleted;
799 }
800 
801 /* tipc_node_timeout - handle expiration of node timer
802  */
803 static void tipc_node_timeout(struct timer_list *t)
804 {
805 	struct tipc_node *n = from_timer(n, t, timer);
806 	struct tipc_link_entry *le;
807 	struct sk_buff_head xmitq;
808 	int remains = n->link_cnt;
809 	int bearer_id;
810 	int rc = 0;
811 
812 	trace_tipc_node_timeout(n, false, " ");
813 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
814 		/*Removing the reference of Timer*/
815 		tipc_node_put(n);
816 		return;
817 	}
818 
819 #ifdef CONFIG_TIPC_CRYPTO
820 	/* Take any crypto key related actions first */
821 	tipc_crypto_timeout(n->crypto_rx);
822 #endif
823 	__skb_queue_head_init(&xmitq);
824 
825 	/* Initial node interval to value larger (10 seconds), then it will be
826 	 * recalculated with link lowest tolerance
827 	 */
828 	tipc_node_read_lock(n);
829 	n->keepalive_intv = 10000;
830 	tipc_node_read_unlock(n);
831 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
832 		tipc_node_read_lock(n);
833 		le = &n->links[bearer_id];
834 		if (le->link) {
835 			spin_lock_bh(&le->lock);
836 			/* Link tolerance may change asynchronously: */
837 			tipc_node_calculate_timer(n, le->link);
838 			rc = tipc_link_timeout(le->link, &xmitq);
839 			spin_unlock_bh(&le->lock);
840 			remains--;
841 		}
842 		tipc_node_read_unlock(n);
843 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr, n);
844 		if (rc & TIPC_LINK_DOWN_EVT)
845 			tipc_node_link_down(n, bearer_id, false);
846 	}
847 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
848 }
849 
850 /**
851  * __tipc_node_link_up - handle addition of link
852  * @n: target tipc_node
853  * @bearer_id: id of the bearer
854  * @xmitq: queue for messages to be xmited on
855  * Node lock must be held by caller
856  * Link becomes active (alone or shared) or standby, depending on its priority.
857  */
858 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
859 				struct sk_buff_head *xmitq)
860 {
861 	int *slot0 = &n->active_links[0];
862 	int *slot1 = &n->active_links[1];
863 	struct tipc_link *ol = node_active_link(n, 0);
864 	struct tipc_link *nl = n->links[bearer_id].link;
865 
866 	if (!nl || tipc_link_is_up(nl))
867 		return;
868 
869 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
870 	if (!tipc_link_is_up(nl))
871 		return;
872 
873 	n->working_links++;
874 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
875 	n->link_id = tipc_link_id(nl);
876 
877 	/* Leave room for tunnel header when returning 'mtu' to users: */
878 	n->links[bearer_id].mtu = tipc_link_mss(nl);
879 
880 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
881 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
882 
883 	pr_debug("Established link <%s> on network plane %c\n",
884 		 tipc_link_name(nl), tipc_link_plane(nl));
885 	trace_tipc_node_link_up(n, true, " ");
886 
887 	/* Ensure that a STATE message goes first */
888 	tipc_link_build_state_msg(nl, xmitq);
889 
890 	/* First link? => give it both slots */
891 	if (!ol) {
892 		*slot0 = bearer_id;
893 		*slot1 = bearer_id;
894 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
895 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
896 		tipc_link_set_active(nl, true);
897 		tipc_bcast_add_peer(n->net, nl, xmitq);
898 		return;
899 	}
900 
901 	/* Second link => redistribute slots */
902 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
903 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
904 		*slot0 = bearer_id;
905 		*slot1 = bearer_id;
906 		tipc_link_set_active(nl, true);
907 		tipc_link_set_active(ol, false);
908 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
909 		tipc_link_set_active(nl, true);
910 		*slot1 = bearer_id;
911 	} else {
912 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
913 	}
914 
915 	/* Prepare synchronization with first link */
916 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
917 }
918 
919 /**
920  * tipc_node_link_up - handle addition of link
921  * @n: target tipc_node
922  * @bearer_id: id of the bearer
923  * @xmitq: queue for messages to be xmited on
924  *
925  * Link becomes active (alone or shared) or standby, depending on its priority.
926  */
927 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
928 			      struct sk_buff_head *xmitq)
929 {
930 	struct tipc_media_addr *maddr;
931 
932 	tipc_node_write_lock(n);
933 	__tipc_node_link_up(n, bearer_id, xmitq);
934 	maddr = &n->links[bearer_id].maddr;
935 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr, n);
936 	tipc_node_write_unlock(n);
937 }
938 
939 /**
940  * tipc_node_link_failover() - start failover in case "half-failover"
941  *
942  * This function is only called in a very special situation where link
943  * failover can be already started on peer node but not on this node.
944  * This can happen when e.g.::
945  *
946  *	1. Both links <1A-2A>, <1B-2B> down
947  *	2. Link endpoint 2A up, but 1A still down (e.g. due to network
948  *	disturbance, wrong session, etc.)
949  *	3. Link <1B-2B> up
950  *	4. Link endpoint 2A down (e.g. due to link tolerance timeout)
951  *	5. Node 2 starts failover onto link <1B-2B>
952  *
953  *	==> Node 1 does never start link/node failover!
954  *
955  * @n: tipc node structure
956  * @l: link peer endpoint failingover (- can be NULL)
957  * @tnl: tunnel link
958  * @xmitq: queue for messages to be xmited on tnl link later
959  */
960 static void tipc_node_link_failover(struct tipc_node *n, struct tipc_link *l,
961 				    struct tipc_link *tnl,
962 				    struct sk_buff_head *xmitq)
963 {
964 	/* Avoid to be "self-failover" that can never end */
965 	if (!tipc_link_is_up(tnl))
966 		return;
967 
968 	/* Don't rush, failure link may be in the process of resetting */
969 	if (l && !tipc_link_is_reset(l))
970 		return;
971 
972 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
973 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
974 
975 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
976 	tipc_link_failover_prepare(l, tnl, xmitq);
977 
978 	if (l)
979 		tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
980 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
981 }
982 
983 /**
984  * __tipc_node_link_down - handle loss of link
985  * @n: target tipc_node
986  * @bearer_id: id of the bearer
987  * @xmitq: queue for messages to be xmited on
988  * @maddr: output media address of the bearer
989  */
990 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
991 				  struct sk_buff_head *xmitq,
992 				  struct tipc_media_addr **maddr)
993 {
994 	struct tipc_link_entry *le = &n->links[*bearer_id];
995 	int *slot0 = &n->active_links[0];
996 	int *slot1 = &n->active_links[1];
997 	int i, highest = 0, prio;
998 	struct tipc_link *l, *_l, *tnl;
999 
1000 	l = n->links[*bearer_id].link;
1001 	if (!l || tipc_link_is_reset(l))
1002 		return;
1003 
1004 	n->working_links--;
1005 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
1006 	n->link_id = tipc_link_id(l);
1007 
1008 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
1009 
1010 	pr_debug("Lost link <%s> on network plane %c\n",
1011 		 tipc_link_name(l), tipc_link_plane(l));
1012 
1013 	/* Select new active link if any available */
1014 	*slot0 = INVALID_BEARER_ID;
1015 	*slot1 = INVALID_BEARER_ID;
1016 	for (i = 0; i < MAX_BEARERS; i++) {
1017 		_l = n->links[i].link;
1018 		if (!_l || !tipc_link_is_up(_l))
1019 			continue;
1020 		if (_l == l)
1021 			continue;
1022 		prio = tipc_link_prio(_l);
1023 		if (prio < highest)
1024 			continue;
1025 		if (prio > highest) {
1026 			highest = prio;
1027 			*slot0 = i;
1028 			*slot1 = i;
1029 			continue;
1030 		}
1031 		*slot1 = i;
1032 	}
1033 
1034 	if (!node_is_up(n)) {
1035 		if (tipc_link_peer_is_down(l))
1036 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1037 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
1038 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
1039 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1040 		tipc_link_reset(l);
1041 		tipc_link_build_reset_msg(l, xmitq);
1042 		*maddr = &n->links[*bearer_id].maddr;
1043 		node_lost_contact(n, &le->inputq);
1044 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
1045 		return;
1046 	}
1047 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
1048 
1049 	/* There is still a working link => initiate failover */
1050 	*bearer_id = n->active_links[0];
1051 	tnl = n->links[*bearer_id].link;
1052 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1053 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1054 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
1055 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
1056 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
1057 	tipc_link_reset(l);
1058 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
1059 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1060 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
1061 	*maddr = &n->links[*bearer_id].maddr;
1062 }
1063 
1064 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
1065 {
1066 	struct tipc_link_entry *le = &n->links[bearer_id];
1067 	struct tipc_media_addr *maddr = NULL;
1068 	struct tipc_link *l = le->link;
1069 	int old_bearer_id = bearer_id;
1070 	struct sk_buff_head xmitq;
1071 
1072 	if (!l)
1073 		return;
1074 
1075 	__skb_queue_head_init(&xmitq);
1076 
1077 	tipc_node_write_lock(n);
1078 	if (!tipc_link_is_establishing(l)) {
1079 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
1080 	} else {
1081 		/* Defuse pending tipc_node_link_up() */
1082 		tipc_link_reset(l);
1083 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1084 	}
1085 	if (delete) {
1086 		kfree(l);
1087 		le->link = NULL;
1088 		n->link_cnt--;
1089 	}
1090 	trace_tipc_node_link_down(n, true, "node link down or deleted!");
1091 	tipc_node_write_unlock(n);
1092 	if (delete)
1093 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
1094 	if (!skb_queue_empty(&xmitq))
1095 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr, n);
1096 	tipc_sk_rcv(n->net, &le->inputq);
1097 }
1098 
1099 static bool node_is_up(struct tipc_node *n)
1100 {
1101 	return n->active_links[0] != INVALID_BEARER_ID;
1102 }
1103 
1104 bool tipc_node_is_up(struct net *net, u32 addr)
1105 {
1106 	struct tipc_node *n;
1107 	bool retval = false;
1108 
1109 	if (in_own_node(net, addr))
1110 		return true;
1111 
1112 	n = tipc_node_find(net, addr);
1113 	if (!n)
1114 		return false;
1115 	retval = node_is_up(n);
1116 	tipc_node_put(n);
1117 	return retval;
1118 }
1119 
1120 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
1121 {
1122 	struct tipc_node *n;
1123 
1124 	addr ^= tipc_net(net)->random;
1125 	while ((n = tipc_node_find(net, addr))) {
1126 		tipc_node_put(n);
1127 		addr++;
1128 	}
1129 	return addr;
1130 }
1131 
1132 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
1133  * Returns suggested address if any, otherwise 0
1134  */
1135 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
1136 {
1137 	struct tipc_net *tn = tipc_net(net);
1138 	struct tipc_node *n;
1139 	bool preliminary;
1140 	u32 sugg_addr;
1141 
1142 	/* Suggest new address if some other peer is using this one */
1143 	n = tipc_node_find(net, addr);
1144 	if (n) {
1145 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
1146 			addr = 0;
1147 		tipc_node_put(n);
1148 		if (!addr)
1149 			return 0;
1150 		return tipc_node_suggest_addr(net, addr);
1151 	}
1152 
1153 	/* Suggest previously used address if peer is known */
1154 	n = tipc_node_find_by_id(net, id);
1155 	if (n) {
1156 		sugg_addr = n->addr;
1157 		preliminary = n->preliminary;
1158 		tipc_node_put(n);
1159 		if (!preliminary)
1160 			return sugg_addr;
1161 	}
1162 
1163 	/* Even this node may be in conflict */
1164 	if (tn->trial_addr == addr)
1165 		return tipc_node_suggest_addr(net, addr);
1166 
1167 	return 0;
1168 }
1169 
1170 void tipc_node_check_dest(struct net *net, u32 addr,
1171 			  u8 *peer_id, struct tipc_bearer *b,
1172 			  u16 capabilities, u32 signature, u32 hash_mixes,
1173 			  struct tipc_media_addr *maddr,
1174 			  bool *respond, bool *dupl_addr)
1175 {
1176 	struct tipc_node *n;
1177 	struct tipc_link *l;
1178 	struct tipc_link_entry *le;
1179 	bool addr_match = false;
1180 	bool sign_match = false;
1181 	bool link_up = false;
1182 	bool accept_addr = false;
1183 	bool reset = true;
1184 	char *if_name;
1185 	unsigned long intv;
1186 	u16 session;
1187 
1188 	*dupl_addr = false;
1189 	*respond = false;
1190 
1191 	n = tipc_node_create(net, addr, peer_id, capabilities, hash_mixes,
1192 			     false);
1193 	if (!n)
1194 		return;
1195 
1196 	tipc_node_write_lock(n);
1197 
1198 	le = &n->links[b->identity];
1199 
1200 	/* Prepare to validate requesting node's signature and media address */
1201 	l = le->link;
1202 	link_up = l && tipc_link_is_up(l);
1203 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1204 	sign_match = (signature == n->signature);
1205 
1206 	/* These three flags give us eight permutations: */
1207 
1208 	if (sign_match && addr_match && link_up) {
1209 		/* All is fine. Do nothing. */
1210 		reset = false;
1211 		/* Peer node is not a container/local namespace */
1212 		if (!n->peer_hash_mix)
1213 			n->peer_hash_mix = hash_mixes;
1214 	} else if (sign_match && addr_match && !link_up) {
1215 		/* Respond. The link will come up in due time */
1216 		*respond = true;
1217 	} else if (sign_match && !addr_match && link_up) {
1218 		/* Peer has changed i/f address without rebooting.
1219 		 * If so, the link will reset soon, and the next
1220 		 * discovery will be accepted. So we can ignore it.
1221 		 * It may also be a cloned or malicious peer having
1222 		 * chosen the same node address and signature as an
1223 		 * existing one.
1224 		 * Ignore requests until the link goes down, if ever.
1225 		 */
1226 		*dupl_addr = true;
1227 	} else if (sign_match && !addr_match && !link_up) {
1228 		/* Peer link has changed i/f address without rebooting.
1229 		 * It may also be a cloned or malicious peer; we can't
1230 		 * distinguish between the two.
1231 		 * The signature is correct, so we must accept.
1232 		 */
1233 		accept_addr = true;
1234 		*respond = true;
1235 	} else if (!sign_match && addr_match && link_up) {
1236 		/* Peer node rebooted. Two possibilities:
1237 		 *  - Delayed re-discovery; this link endpoint has already
1238 		 *    reset and re-established contact with the peer, before
1239 		 *    receiving a discovery message from that node.
1240 		 *    (The peer happened to receive one from this node first).
1241 		 *  - The peer came back so fast that our side has not
1242 		 *    discovered it yet. Probing from this side will soon
1243 		 *    reset the link, since there can be no working link
1244 		 *    endpoint at the peer end, and the link will re-establish.
1245 		 *  Accept the signature, since it comes from a known peer.
1246 		 */
1247 		n->signature = signature;
1248 	} else if (!sign_match && addr_match && !link_up) {
1249 		/*  The peer node has rebooted.
1250 		 *  Accept signature, since it is a known peer.
1251 		 */
1252 		n->signature = signature;
1253 		*respond = true;
1254 	} else if (!sign_match && !addr_match && link_up) {
1255 		/* Peer rebooted with new address, or a new/duplicate peer.
1256 		 * Ignore until the link goes down, if ever.
1257 		 */
1258 		*dupl_addr = true;
1259 	} else if (!sign_match && !addr_match && !link_up) {
1260 		/* Peer rebooted with new address, or it is a new peer.
1261 		 * Accept signature and address.
1262 		 */
1263 		n->signature = signature;
1264 		accept_addr = true;
1265 		*respond = true;
1266 	}
1267 
1268 	if (!accept_addr)
1269 		goto exit;
1270 
1271 	/* Now create new link if not already existing */
1272 	if (!l) {
1273 		if (n->link_cnt == 2)
1274 			goto exit;
1275 
1276 		if_name = strchr(b->name, ':') + 1;
1277 		get_random_bytes(&session, sizeof(u16));
1278 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1279 				      b->net_plane, b->mtu, b->priority,
1280 				      b->min_win, b->max_win, session,
1281 				      tipc_own_addr(net), addr, peer_id,
1282 				      n->capabilities,
1283 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1284 				      &le->inputq,
1285 				      &n->bc_entry.namedq, &l)) {
1286 			*respond = false;
1287 			goto exit;
1288 		}
1289 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1290 		tipc_link_reset(l);
1291 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1292 		if (n->state == NODE_FAILINGOVER)
1293 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1294 		le->link = l;
1295 		n->link_cnt++;
1296 		tipc_node_calculate_timer(n, l);
1297 		if (n->link_cnt == 1) {
1298 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1299 			if (!mod_timer(&n->timer, intv))
1300 				tipc_node_get(n);
1301 		}
1302 	}
1303 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1304 exit:
1305 	tipc_node_write_unlock(n);
1306 	if (reset && l && !tipc_link_is_reset(l))
1307 		tipc_node_link_down(n, b->identity, false);
1308 	tipc_node_put(n);
1309 }
1310 
1311 void tipc_node_delete_links(struct net *net, int bearer_id)
1312 {
1313 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1314 	struct tipc_node *n;
1315 
1316 	rcu_read_lock();
1317 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1318 		tipc_node_link_down(n, bearer_id, true);
1319 	}
1320 	rcu_read_unlock();
1321 }
1322 
1323 static void tipc_node_reset_links(struct tipc_node *n)
1324 {
1325 	int i;
1326 
1327 	pr_warn("Resetting all links to %x\n", n->addr);
1328 
1329 	trace_tipc_node_reset_links(n, true, " ");
1330 	for (i = 0; i < MAX_BEARERS; i++) {
1331 		tipc_node_link_down(n, i, false);
1332 	}
1333 }
1334 
1335 /* tipc_node_fsm_evt - node finite state machine
1336  * Determines when contact is allowed with peer node
1337  */
1338 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1339 {
1340 	int state = n->state;
1341 
1342 	switch (state) {
1343 	case SELF_DOWN_PEER_DOWN:
1344 		switch (evt) {
1345 		case SELF_ESTABL_CONTACT_EVT:
1346 			state = SELF_UP_PEER_COMING;
1347 			break;
1348 		case PEER_ESTABL_CONTACT_EVT:
1349 			state = SELF_COMING_PEER_UP;
1350 			break;
1351 		case SELF_LOST_CONTACT_EVT:
1352 		case PEER_LOST_CONTACT_EVT:
1353 			break;
1354 		case NODE_SYNCH_END_EVT:
1355 		case NODE_SYNCH_BEGIN_EVT:
1356 		case NODE_FAILOVER_BEGIN_EVT:
1357 		case NODE_FAILOVER_END_EVT:
1358 		default:
1359 			goto illegal_evt;
1360 		}
1361 		break;
1362 	case SELF_UP_PEER_UP:
1363 		switch (evt) {
1364 		case SELF_LOST_CONTACT_EVT:
1365 			state = SELF_DOWN_PEER_LEAVING;
1366 			break;
1367 		case PEER_LOST_CONTACT_EVT:
1368 			state = SELF_LEAVING_PEER_DOWN;
1369 			break;
1370 		case NODE_SYNCH_BEGIN_EVT:
1371 			state = NODE_SYNCHING;
1372 			break;
1373 		case NODE_FAILOVER_BEGIN_EVT:
1374 			state = NODE_FAILINGOVER;
1375 			break;
1376 		case SELF_ESTABL_CONTACT_EVT:
1377 		case PEER_ESTABL_CONTACT_EVT:
1378 		case NODE_SYNCH_END_EVT:
1379 		case NODE_FAILOVER_END_EVT:
1380 			break;
1381 		default:
1382 			goto illegal_evt;
1383 		}
1384 		break;
1385 	case SELF_DOWN_PEER_LEAVING:
1386 		switch (evt) {
1387 		case PEER_LOST_CONTACT_EVT:
1388 			state = SELF_DOWN_PEER_DOWN;
1389 			break;
1390 		case SELF_ESTABL_CONTACT_EVT:
1391 		case PEER_ESTABL_CONTACT_EVT:
1392 		case SELF_LOST_CONTACT_EVT:
1393 			break;
1394 		case NODE_SYNCH_END_EVT:
1395 		case NODE_SYNCH_BEGIN_EVT:
1396 		case NODE_FAILOVER_BEGIN_EVT:
1397 		case NODE_FAILOVER_END_EVT:
1398 		default:
1399 			goto illegal_evt;
1400 		}
1401 		break;
1402 	case SELF_UP_PEER_COMING:
1403 		switch (evt) {
1404 		case PEER_ESTABL_CONTACT_EVT:
1405 			state = SELF_UP_PEER_UP;
1406 			break;
1407 		case SELF_LOST_CONTACT_EVT:
1408 			state = SELF_DOWN_PEER_DOWN;
1409 			break;
1410 		case SELF_ESTABL_CONTACT_EVT:
1411 		case PEER_LOST_CONTACT_EVT:
1412 		case NODE_SYNCH_END_EVT:
1413 		case NODE_FAILOVER_BEGIN_EVT:
1414 			break;
1415 		case NODE_SYNCH_BEGIN_EVT:
1416 		case NODE_FAILOVER_END_EVT:
1417 		default:
1418 			goto illegal_evt;
1419 		}
1420 		break;
1421 	case SELF_COMING_PEER_UP:
1422 		switch (evt) {
1423 		case SELF_ESTABL_CONTACT_EVT:
1424 			state = SELF_UP_PEER_UP;
1425 			break;
1426 		case PEER_LOST_CONTACT_EVT:
1427 			state = SELF_DOWN_PEER_DOWN;
1428 			break;
1429 		case SELF_LOST_CONTACT_EVT:
1430 		case PEER_ESTABL_CONTACT_EVT:
1431 			break;
1432 		case NODE_SYNCH_END_EVT:
1433 		case NODE_SYNCH_BEGIN_EVT:
1434 		case NODE_FAILOVER_BEGIN_EVT:
1435 		case NODE_FAILOVER_END_EVT:
1436 		default:
1437 			goto illegal_evt;
1438 		}
1439 		break;
1440 	case SELF_LEAVING_PEER_DOWN:
1441 		switch (evt) {
1442 		case SELF_LOST_CONTACT_EVT:
1443 			state = SELF_DOWN_PEER_DOWN;
1444 			break;
1445 		case SELF_ESTABL_CONTACT_EVT:
1446 		case PEER_ESTABL_CONTACT_EVT:
1447 		case PEER_LOST_CONTACT_EVT:
1448 			break;
1449 		case NODE_SYNCH_END_EVT:
1450 		case NODE_SYNCH_BEGIN_EVT:
1451 		case NODE_FAILOVER_BEGIN_EVT:
1452 		case NODE_FAILOVER_END_EVT:
1453 		default:
1454 			goto illegal_evt;
1455 		}
1456 		break;
1457 	case NODE_FAILINGOVER:
1458 		switch (evt) {
1459 		case SELF_LOST_CONTACT_EVT:
1460 			state = SELF_DOWN_PEER_LEAVING;
1461 			break;
1462 		case PEER_LOST_CONTACT_EVT:
1463 			state = SELF_LEAVING_PEER_DOWN;
1464 			break;
1465 		case NODE_FAILOVER_END_EVT:
1466 			state = SELF_UP_PEER_UP;
1467 			break;
1468 		case NODE_FAILOVER_BEGIN_EVT:
1469 		case SELF_ESTABL_CONTACT_EVT:
1470 		case PEER_ESTABL_CONTACT_EVT:
1471 			break;
1472 		case NODE_SYNCH_BEGIN_EVT:
1473 		case NODE_SYNCH_END_EVT:
1474 		default:
1475 			goto illegal_evt;
1476 		}
1477 		break;
1478 	case NODE_SYNCHING:
1479 		switch (evt) {
1480 		case SELF_LOST_CONTACT_EVT:
1481 			state = SELF_DOWN_PEER_LEAVING;
1482 			break;
1483 		case PEER_LOST_CONTACT_EVT:
1484 			state = SELF_LEAVING_PEER_DOWN;
1485 			break;
1486 		case NODE_SYNCH_END_EVT:
1487 			state = SELF_UP_PEER_UP;
1488 			break;
1489 		case NODE_FAILOVER_BEGIN_EVT:
1490 			state = NODE_FAILINGOVER;
1491 			break;
1492 		case NODE_SYNCH_BEGIN_EVT:
1493 		case SELF_ESTABL_CONTACT_EVT:
1494 		case PEER_ESTABL_CONTACT_EVT:
1495 			break;
1496 		case NODE_FAILOVER_END_EVT:
1497 		default:
1498 			goto illegal_evt;
1499 		}
1500 		break;
1501 	default:
1502 		pr_err("Unknown node fsm state %x\n", state);
1503 		break;
1504 	}
1505 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1506 	n->state = state;
1507 	return;
1508 
1509 illegal_evt:
1510 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1511 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1512 }
1513 
1514 static void node_lost_contact(struct tipc_node *n,
1515 			      struct sk_buff_head *inputq)
1516 {
1517 	struct tipc_sock_conn *conn, *safe;
1518 	struct tipc_link *l;
1519 	struct list_head *conns = &n->conn_sks;
1520 	struct sk_buff *skb;
1521 	uint i;
1522 
1523 	pr_debug("Lost contact with %x\n", n->addr);
1524 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1525 	trace_tipc_node_lost_contact(n, true, " ");
1526 
1527 	/* Clean up broadcast state */
1528 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1529 	skb_queue_purge(&n->bc_entry.namedq);
1530 
1531 	/* Abort any ongoing link failover */
1532 	for (i = 0; i < MAX_BEARERS; i++) {
1533 		l = n->links[i].link;
1534 		if (l)
1535 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1536 	}
1537 
1538 	/* Notify publications from this node */
1539 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1540 	n->peer_net = NULL;
1541 	n->peer_hash_mix = 0;
1542 	/* Notify sockets connected to node */
1543 	list_for_each_entry_safe(conn, safe, conns, list) {
1544 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1545 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1546 				      conn->peer_node, conn->port,
1547 				      conn->peer_port, TIPC_ERR_NO_NODE);
1548 		if (likely(skb))
1549 			skb_queue_tail(inputq, skb);
1550 		list_del(&conn->list);
1551 		kfree(conn);
1552 	}
1553 }
1554 
1555 /**
1556  * tipc_node_get_linkname - get the name of a link
1557  *
1558  * @net: the applicable net namespace
1559  * @bearer_id: id of the bearer
1560  * @addr: peer node address
1561  * @linkname: link name output buffer
1562  * @len: size of @linkname output buffer
1563  *
1564  * Return: 0 on success
1565  */
1566 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1567 			   char *linkname, size_t len)
1568 {
1569 	struct tipc_link *link;
1570 	int err = -EINVAL;
1571 	struct tipc_node *node = tipc_node_find(net, addr);
1572 
1573 	if (!node)
1574 		return err;
1575 
1576 	if (bearer_id >= MAX_BEARERS)
1577 		goto exit;
1578 
1579 	tipc_node_read_lock(node);
1580 	link = node->links[bearer_id].link;
1581 	if (link) {
1582 		strncpy(linkname, tipc_link_name(link), len);
1583 		err = 0;
1584 	}
1585 	tipc_node_read_unlock(node);
1586 exit:
1587 	tipc_node_put(node);
1588 	return err;
1589 }
1590 
1591 /* Caller should hold node lock for the passed node */
1592 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1593 {
1594 	void *hdr;
1595 	struct nlattr *attrs;
1596 
1597 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1598 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1599 	if (!hdr)
1600 		return -EMSGSIZE;
1601 
1602 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1603 	if (!attrs)
1604 		goto msg_full;
1605 
1606 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1607 		goto attr_msg_full;
1608 	if (node_is_up(node))
1609 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1610 			goto attr_msg_full;
1611 
1612 	nla_nest_end(msg->skb, attrs);
1613 	genlmsg_end(msg->skb, hdr);
1614 
1615 	return 0;
1616 
1617 attr_msg_full:
1618 	nla_nest_cancel(msg->skb, attrs);
1619 msg_full:
1620 	genlmsg_cancel(msg->skb, hdr);
1621 
1622 	return -EMSGSIZE;
1623 }
1624 
1625 static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)
1626 {
1627 	struct tipc_msg *hdr = buf_msg(skb_peek(list));
1628 	struct sk_buff_head inputq;
1629 
1630 	switch (msg_user(hdr)) {
1631 	case TIPC_LOW_IMPORTANCE:
1632 	case TIPC_MEDIUM_IMPORTANCE:
1633 	case TIPC_HIGH_IMPORTANCE:
1634 	case TIPC_CRITICAL_IMPORTANCE:
1635 		if (msg_connected(hdr) || msg_named(hdr) ||
1636 		    msg_direct(hdr)) {
1637 			tipc_loopback_trace(peer_net, list);
1638 			spin_lock_init(&list->lock);
1639 			tipc_sk_rcv(peer_net, list);
1640 			return;
1641 		}
1642 		if (msg_mcast(hdr)) {
1643 			tipc_loopback_trace(peer_net, list);
1644 			skb_queue_head_init(&inputq);
1645 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1646 			__skb_queue_purge(list);
1647 			skb_queue_purge(&inputq);
1648 			return;
1649 		}
1650 		return;
1651 	case MSG_FRAGMENTER:
1652 		if (tipc_msg_assemble(list)) {
1653 			tipc_loopback_trace(peer_net, list);
1654 			skb_queue_head_init(&inputq);
1655 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1656 			__skb_queue_purge(list);
1657 			skb_queue_purge(&inputq);
1658 		}
1659 		return;
1660 	case GROUP_PROTOCOL:
1661 	case CONN_MANAGER:
1662 		tipc_loopback_trace(peer_net, list);
1663 		spin_lock_init(&list->lock);
1664 		tipc_sk_rcv(peer_net, list);
1665 		return;
1666 	case LINK_PROTOCOL:
1667 	case NAME_DISTRIBUTOR:
1668 	case TUNNEL_PROTOCOL:
1669 	case BCAST_PROTOCOL:
1670 		return;
1671 	default:
1672 		return;
1673 	}
1674 }
1675 
1676 /**
1677  * tipc_node_xmit() - general link level function for message sending
1678  * @net: the applicable net namespace
1679  * @list: chain of buffers containing message
1680  * @dnode: address of destination node
1681  * @selector: a number used for deterministic link selection
1682  * Consumes the buffer chain.
1683  * Return: 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1684  */
1685 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1686 		   u32 dnode, int selector)
1687 {
1688 	struct tipc_link_entry *le = NULL;
1689 	struct tipc_node *n;
1690 	struct sk_buff_head xmitq;
1691 	bool node_up = false;
1692 	int bearer_id;
1693 	int rc;
1694 
1695 	if (in_own_node(net, dnode)) {
1696 		tipc_loopback_trace(net, list);
1697 		spin_lock_init(&list->lock);
1698 		tipc_sk_rcv(net, list);
1699 		return 0;
1700 	}
1701 
1702 	n = tipc_node_find(net, dnode);
1703 	if (unlikely(!n)) {
1704 		__skb_queue_purge(list);
1705 		return -EHOSTUNREACH;
1706 	}
1707 
1708 	tipc_node_read_lock(n);
1709 	node_up = node_is_up(n);
1710 	if (node_up && n->peer_net && check_net(n->peer_net)) {
1711 		/* xmit inner linux container */
1712 		tipc_lxc_xmit(n->peer_net, list);
1713 		if (likely(skb_queue_empty(list))) {
1714 			tipc_node_read_unlock(n);
1715 			tipc_node_put(n);
1716 			return 0;
1717 		}
1718 	}
1719 
1720 	bearer_id = n->active_links[selector & 1];
1721 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1722 		tipc_node_read_unlock(n);
1723 		tipc_node_put(n);
1724 		__skb_queue_purge(list);
1725 		return -EHOSTUNREACH;
1726 	}
1727 
1728 	__skb_queue_head_init(&xmitq);
1729 	le = &n->links[bearer_id];
1730 	spin_lock_bh(&le->lock);
1731 	rc = tipc_link_xmit(le->link, list, &xmitq);
1732 	spin_unlock_bh(&le->lock);
1733 	tipc_node_read_unlock(n);
1734 
1735 	if (unlikely(rc == -ENOBUFS))
1736 		tipc_node_link_down(n, bearer_id, false);
1737 	else
1738 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1739 
1740 	tipc_node_put(n);
1741 
1742 	return rc;
1743 }
1744 
1745 /* tipc_node_xmit_skb(): send single buffer to destination
1746  * Buffers sent via this function are generally TIPC_SYSTEM_IMPORTANCE
1747  * messages, which will not be rejected
1748  * The only exception is datagram messages rerouted after secondary
1749  * lookup, which are rare and safe to dispose of anyway.
1750  */
1751 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1752 		       u32 selector)
1753 {
1754 	struct sk_buff_head head;
1755 
1756 	__skb_queue_head_init(&head);
1757 	__skb_queue_tail(&head, skb);
1758 	tipc_node_xmit(net, &head, dnode, selector);
1759 	return 0;
1760 }
1761 
1762 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1763  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1764  */
1765 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1766 {
1767 	struct sk_buff *skb;
1768 	u32 selector, dnode;
1769 
1770 	while ((skb = __skb_dequeue(xmitq))) {
1771 		selector = msg_origport(buf_msg(skb));
1772 		dnode = msg_destnode(buf_msg(skb));
1773 		tipc_node_xmit_skb(net, skb, dnode, selector);
1774 	}
1775 	return 0;
1776 }
1777 
1778 void tipc_node_broadcast(struct net *net, struct sk_buff *skb, int rc_dests)
1779 {
1780 	struct sk_buff_head xmitq;
1781 	struct sk_buff *txskb;
1782 	struct tipc_node *n;
1783 	u16 dummy;
1784 	u32 dst;
1785 
1786 	/* Use broadcast if all nodes support it */
1787 	if (!rc_dests && tipc_bcast_get_mode(net) != BCLINK_MODE_RCAST) {
1788 		__skb_queue_head_init(&xmitq);
1789 		__skb_queue_tail(&xmitq, skb);
1790 		tipc_bcast_xmit(net, &xmitq, &dummy);
1791 		return;
1792 	}
1793 
1794 	/* Otherwise use legacy replicast method */
1795 	rcu_read_lock();
1796 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1797 		dst = n->addr;
1798 		if (in_own_node(net, dst))
1799 			continue;
1800 		if (!node_is_up(n))
1801 			continue;
1802 		txskb = pskb_copy(skb, GFP_ATOMIC);
1803 		if (!txskb)
1804 			break;
1805 		msg_set_destnode(buf_msg(txskb), dst);
1806 		tipc_node_xmit_skb(net, txskb, dst, 0);
1807 	}
1808 	rcu_read_unlock();
1809 	kfree_skb(skb);
1810 }
1811 
1812 static void tipc_node_mcast_rcv(struct tipc_node *n)
1813 {
1814 	struct tipc_bclink_entry *be = &n->bc_entry;
1815 
1816 	/* 'arrvq' is under inputq2's lock protection */
1817 	spin_lock_bh(&be->inputq2.lock);
1818 	spin_lock_bh(&be->inputq1.lock);
1819 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1820 	spin_unlock_bh(&be->inputq1.lock);
1821 	spin_unlock_bh(&be->inputq2.lock);
1822 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1823 }
1824 
1825 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1826 				  int bearer_id, struct sk_buff_head *xmitq)
1827 {
1828 	struct tipc_link *ucl;
1829 	int rc;
1830 
1831 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr, xmitq);
1832 
1833 	if (rc & TIPC_LINK_DOWN_EVT) {
1834 		tipc_node_reset_links(n);
1835 		return;
1836 	}
1837 
1838 	if (!(rc & TIPC_LINK_SND_STATE))
1839 		return;
1840 
1841 	/* If probe message, a STATE response will be sent anyway */
1842 	if (msg_probe(hdr))
1843 		return;
1844 
1845 	/* Produce a STATE message carrying broadcast NACK */
1846 	tipc_node_read_lock(n);
1847 	ucl = n->links[bearer_id].link;
1848 	if (ucl)
1849 		tipc_link_build_state_msg(ucl, xmitq);
1850 	tipc_node_read_unlock(n);
1851 }
1852 
1853 /**
1854  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1855  * @net: the applicable net namespace
1856  * @skb: TIPC packet
1857  * @bearer_id: id of bearer message arrived on
1858  *
1859  * Invoked with no locks held.
1860  */
1861 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1862 {
1863 	int rc;
1864 	struct sk_buff_head xmitq;
1865 	struct tipc_bclink_entry *be;
1866 	struct tipc_link_entry *le;
1867 	struct tipc_msg *hdr = buf_msg(skb);
1868 	int usr = msg_user(hdr);
1869 	u32 dnode = msg_destnode(hdr);
1870 	struct tipc_node *n;
1871 
1872 	__skb_queue_head_init(&xmitq);
1873 
1874 	/* If NACK for other node, let rcv link for that node peek into it */
1875 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1876 		n = tipc_node_find(net, dnode);
1877 	else
1878 		n = tipc_node_find(net, msg_prevnode(hdr));
1879 	if (!n) {
1880 		kfree_skb(skb);
1881 		return;
1882 	}
1883 	be = &n->bc_entry;
1884 	le = &n->links[bearer_id];
1885 
1886 	rc = tipc_bcast_rcv(net, be->link, skb);
1887 
1888 	/* Broadcast ACKs are sent on a unicast link */
1889 	if (rc & TIPC_LINK_SND_STATE) {
1890 		tipc_node_read_lock(n);
1891 		tipc_link_build_state_msg(le->link, &xmitq);
1892 		tipc_node_read_unlock(n);
1893 	}
1894 
1895 	if (!skb_queue_empty(&xmitq))
1896 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1897 
1898 	if (!skb_queue_empty(&be->inputq1))
1899 		tipc_node_mcast_rcv(n);
1900 
1901 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1902 	if (!skb_queue_empty(&n->bc_entry.namedq))
1903 		tipc_named_rcv(net, &n->bc_entry.namedq,
1904 			       &n->bc_entry.named_rcv_nxt,
1905 			       &n->bc_entry.named_open);
1906 
1907 	/* If reassembly or retransmission failure => reset all links to peer */
1908 	if (rc & TIPC_LINK_DOWN_EVT)
1909 		tipc_node_reset_links(n);
1910 
1911 	tipc_node_put(n);
1912 }
1913 
1914 /**
1915  * tipc_node_check_state - check and if necessary update node state
1916  * @n: target tipc_node
1917  * @skb: TIPC packet
1918  * @bearer_id: identity of bearer delivering the packet
1919  * @xmitq: queue for messages to be xmited on
1920  * Return: true if state and msg are ok, otherwise false
1921  */
1922 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1923 				  int bearer_id, struct sk_buff_head *xmitq)
1924 {
1925 	struct tipc_msg *hdr = buf_msg(skb);
1926 	int usr = msg_user(hdr);
1927 	int mtyp = msg_type(hdr);
1928 	u16 oseqno = msg_seqno(hdr);
1929 	u16 exp_pkts = msg_msgcnt(hdr);
1930 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1931 	int state = n->state;
1932 	struct tipc_link *l, *tnl, *pl = NULL;
1933 	struct tipc_media_addr *maddr;
1934 	int pb_id;
1935 
1936 	if (trace_tipc_node_check_state_enabled()) {
1937 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1938 		trace_tipc_node_check_state(n, true, " ");
1939 	}
1940 	l = n->links[bearer_id].link;
1941 	if (!l)
1942 		return false;
1943 	rcv_nxt = tipc_link_rcv_nxt(l);
1944 
1945 
1946 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1947 		return true;
1948 
1949 	/* Find parallel link, if any */
1950 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1951 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1952 			pl = n->links[pb_id].link;
1953 			break;
1954 		}
1955 	}
1956 
1957 	if (!tipc_link_validate_msg(l, hdr)) {
1958 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1959 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1960 		return false;
1961 	}
1962 
1963 	/* Check and update node accesibility if applicable */
1964 	if (state == SELF_UP_PEER_COMING) {
1965 		if (!tipc_link_is_up(l))
1966 			return true;
1967 		if (!msg_peer_link_is_up(hdr))
1968 			return true;
1969 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1970 	}
1971 
1972 	if (state == SELF_DOWN_PEER_LEAVING) {
1973 		if (msg_peer_node_is_up(hdr))
1974 			return false;
1975 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1976 		return true;
1977 	}
1978 
1979 	if (state == SELF_LEAVING_PEER_DOWN)
1980 		return false;
1981 
1982 	/* Ignore duplicate packets */
1983 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1984 		return true;
1985 
1986 	/* Initiate or update failover mode if applicable */
1987 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1988 		syncpt = oseqno + exp_pkts - 1;
1989 		if (pl && !tipc_link_is_reset(pl)) {
1990 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1991 			trace_tipc_node_link_down(n, true,
1992 						  "node link down <- failover!");
1993 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1994 							tipc_link_inputq(l));
1995 		}
1996 
1997 		/* If parallel link was already down, and this happened before
1998 		 * the tunnel link came up, node failover was never started.
1999 		 * Ensure that a FAILOVER_MSG is sent to get peer out of
2000 		 * NODE_FAILINGOVER state, also this node must accept
2001 		 * TUNNEL_MSGs from peer.
2002 		 */
2003 		if (n->state != NODE_FAILINGOVER)
2004 			tipc_node_link_failover(n, pl, l, xmitq);
2005 
2006 		/* If pkts arrive out of order, use lowest calculated syncpt */
2007 		if (less(syncpt, n->sync_point))
2008 			n->sync_point = syncpt;
2009 	}
2010 
2011 	/* Open parallel link when tunnel link reaches synch point */
2012 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
2013 		if (!more(rcv_nxt, n->sync_point))
2014 			return true;
2015 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
2016 		if (pl)
2017 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
2018 		return true;
2019 	}
2020 
2021 	/* No syncing needed if only one link */
2022 	if (!pl || !tipc_link_is_up(pl))
2023 		return true;
2024 
2025 	/* Initiate synch mode if applicable */
2026 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
2027 		if (n->capabilities & TIPC_TUNNEL_ENHANCED)
2028 			syncpt = msg_syncpt(hdr);
2029 		else
2030 			syncpt = msg_seqno(msg_inner_hdr(hdr)) + exp_pkts - 1;
2031 		if (!tipc_link_is_up(l))
2032 			__tipc_node_link_up(n, bearer_id, xmitq);
2033 		if (n->state == SELF_UP_PEER_UP) {
2034 			n->sync_point = syncpt;
2035 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
2036 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
2037 		}
2038 	}
2039 
2040 	/* Open tunnel link when parallel link reaches synch point */
2041 	if (n->state == NODE_SYNCHING) {
2042 		if (tipc_link_is_synching(l)) {
2043 			tnl = l;
2044 		} else {
2045 			tnl = pl;
2046 			pl = l;
2047 		}
2048 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
2049 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
2050 		if (more(dlv_nxt, n->sync_point)) {
2051 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
2052 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
2053 			return true;
2054 		}
2055 		if (l == pl)
2056 			return true;
2057 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
2058 			return true;
2059 		if (usr == LINK_PROTOCOL)
2060 			return true;
2061 		return false;
2062 	}
2063 	return true;
2064 }
2065 
2066 /**
2067  * tipc_rcv - process TIPC packets/messages arriving from off-node
2068  * @net: the applicable net namespace
2069  * @skb: TIPC packet
2070  * @b: pointer to bearer message arrived on
2071  *
2072  * Invoked with no locks held. Bearer pointer must point to a valid bearer
2073  * structure (i.e. cannot be NULL), but bearer can be inactive.
2074  */
2075 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
2076 {
2077 	struct sk_buff_head xmitq;
2078 	struct tipc_link_entry *le;
2079 	struct tipc_msg *hdr;
2080 	struct tipc_node *n;
2081 	int bearer_id = b->identity;
2082 	u32 self = tipc_own_addr(net);
2083 	int usr, rc = 0;
2084 	u16 bc_ack;
2085 #ifdef CONFIG_TIPC_CRYPTO
2086 	struct tipc_ehdr *ehdr;
2087 
2088 	/* Check if message must be decrypted first */
2089 	if (TIPC_SKB_CB(skb)->decrypted || !tipc_ehdr_validate(skb))
2090 		goto rcv;
2091 
2092 	ehdr = (struct tipc_ehdr *)skb->data;
2093 	if (likely(ehdr->user != LINK_CONFIG)) {
2094 		n = tipc_node_find(net, ntohl(ehdr->addr));
2095 		if (unlikely(!n))
2096 			goto discard;
2097 	} else {
2098 		n = tipc_node_find_by_id(net, ehdr->id);
2099 	}
2100 	tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
2101 	if (!skb)
2102 		return;
2103 
2104 rcv:
2105 #endif
2106 	/* Ensure message is well-formed before touching the header */
2107 	if (unlikely(!tipc_msg_validate(&skb)))
2108 		goto discard;
2109 	__skb_queue_head_init(&xmitq);
2110 	hdr = buf_msg(skb);
2111 	usr = msg_user(hdr);
2112 	bc_ack = msg_bcast_ack(hdr);
2113 
2114 	/* Handle arrival of discovery or broadcast packet */
2115 	if (unlikely(msg_non_seq(hdr))) {
2116 		if (unlikely(usr == LINK_CONFIG))
2117 			return tipc_disc_rcv(net, skb, b);
2118 		else
2119 			return tipc_node_bc_rcv(net, skb, bearer_id);
2120 	}
2121 
2122 	/* Discard unicast link messages destined for another node */
2123 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
2124 		goto discard;
2125 
2126 	/* Locate neighboring node that sent packet */
2127 	n = tipc_node_find(net, msg_prevnode(hdr));
2128 	if (unlikely(!n))
2129 		goto discard;
2130 	le = &n->links[bearer_id];
2131 
2132 	/* Ensure broadcast reception is in synch with peer's send state */
2133 	if (unlikely(usr == LINK_PROTOCOL)) {
2134 		if (unlikely(skb_linearize(skb))) {
2135 			tipc_node_put(n);
2136 			goto discard;
2137 		}
2138 		hdr = buf_msg(skb);
2139 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
2140 	} else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack)) {
2141 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
2142 	}
2143 
2144 	/* Receive packet directly if conditions permit */
2145 	tipc_node_read_lock(n);
2146 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
2147 		spin_lock_bh(&le->lock);
2148 		if (le->link) {
2149 			rc = tipc_link_rcv(le->link, skb, &xmitq);
2150 			skb = NULL;
2151 		}
2152 		spin_unlock_bh(&le->lock);
2153 	}
2154 	tipc_node_read_unlock(n);
2155 
2156 	/* Check/update node state before receiving */
2157 	if (unlikely(skb)) {
2158 		if (unlikely(skb_linearize(skb)))
2159 			goto out_node_put;
2160 		tipc_node_write_lock(n);
2161 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
2162 			if (le->link) {
2163 				rc = tipc_link_rcv(le->link, skb, &xmitq);
2164 				skb = NULL;
2165 			}
2166 		}
2167 		tipc_node_write_unlock(n);
2168 	}
2169 
2170 	if (unlikely(rc & TIPC_LINK_UP_EVT))
2171 		tipc_node_link_up(n, bearer_id, &xmitq);
2172 
2173 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
2174 		tipc_node_link_down(n, bearer_id, false);
2175 
2176 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
2177 		tipc_named_rcv(net, &n->bc_entry.namedq,
2178 			       &n->bc_entry.named_rcv_nxt,
2179 			       &n->bc_entry.named_open);
2180 
2181 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
2182 		tipc_node_mcast_rcv(n);
2183 
2184 	if (!skb_queue_empty(&le->inputq))
2185 		tipc_sk_rcv(net, &le->inputq);
2186 
2187 	if (!skb_queue_empty(&xmitq))
2188 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
2189 
2190 out_node_put:
2191 	tipc_node_put(n);
2192 discard:
2193 	kfree_skb(skb);
2194 }
2195 
2196 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
2197 			      int prop)
2198 {
2199 	struct tipc_net *tn = tipc_net(net);
2200 	int bearer_id = b->identity;
2201 	struct sk_buff_head xmitq;
2202 	struct tipc_link_entry *e;
2203 	struct tipc_node *n;
2204 
2205 	__skb_queue_head_init(&xmitq);
2206 
2207 	rcu_read_lock();
2208 
2209 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2210 		tipc_node_write_lock(n);
2211 		e = &n->links[bearer_id];
2212 		if (e->link) {
2213 			if (prop == TIPC_NLA_PROP_TOL)
2214 				tipc_link_set_tolerance(e->link, b->tolerance,
2215 							&xmitq);
2216 			else if (prop == TIPC_NLA_PROP_MTU)
2217 				tipc_link_set_mtu(e->link, b->mtu);
2218 
2219 			/* Update MTU for node link entry */
2220 			e->mtu = tipc_link_mss(e->link);
2221 		}
2222 
2223 		tipc_node_write_unlock(n);
2224 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
2225 	}
2226 
2227 	rcu_read_unlock();
2228 }
2229 
2230 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
2231 {
2232 	struct net *net = sock_net(skb->sk);
2233 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2234 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
2235 	struct tipc_node *peer, *temp_node;
2236 	u8 node_id[NODE_ID_LEN];
2237 	u64 *w0 = (u64 *)&node_id[0];
2238 	u64 *w1 = (u64 *)&node_id[8];
2239 	u32 addr;
2240 	int err;
2241 
2242 	/* We identify the peer by its net */
2243 	if (!info->attrs[TIPC_NLA_NET])
2244 		return -EINVAL;
2245 
2246 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
2247 					  info->attrs[TIPC_NLA_NET],
2248 					  tipc_nl_net_policy, info->extack);
2249 	if (err)
2250 		return err;
2251 
2252 	/* attrs[TIPC_NLA_NET_NODEID] and attrs[TIPC_NLA_NET_ADDR] are
2253 	 * mutually exclusive cases
2254 	 */
2255 	if (attrs[TIPC_NLA_NET_ADDR]) {
2256 		addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
2257 		if (!addr)
2258 			return -EINVAL;
2259 	}
2260 
2261 	if (attrs[TIPC_NLA_NET_NODEID]) {
2262 		if (!attrs[TIPC_NLA_NET_NODEID_W1])
2263 			return -EINVAL;
2264 		*w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
2265 		*w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
2266 		addr = hash128to32(node_id);
2267 	}
2268 
2269 	if (in_own_node(net, addr))
2270 		return -ENOTSUPP;
2271 
2272 	spin_lock_bh(&tn->node_list_lock);
2273 	peer = tipc_node_find(net, addr);
2274 	if (!peer) {
2275 		spin_unlock_bh(&tn->node_list_lock);
2276 		return -ENXIO;
2277 	}
2278 
2279 	tipc_node_write_lock(peer);
2280 	if (peer->state != SELF_DOWN_PEER_DOWN &&
2281 	    peer->state != SELF_DOWN_PEER_LEAVING) {
2282 		tipc_node_write_unlock(peer);
2283 		err = -EBUSY;
2284 		goto err_out;
2285 	}
2286 
2287 	tipc_node_clear_links(peer);
2288 	tipc_node_write_unlock(peer);
2289 	tipc_node_delete(peer);
2290 
2291 	/* Calculate cluster capabilities */
2292 	tn->capabilities = TIPC_NODE_CAPABILITIES;
2293 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
2294 		tn->capabilities &= temp_node->capabilities;
2295 	}
2296 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
2297 	err = 0;
2298 err_out:
2299 	tipc_node_put(peer);
2300 	spin_unlock_bh(&tn->node_list_lock);
2301 
2302 	return err;
2303 }
2304 
2305 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
2306 {
2307 	int err;
2308 	struct net *net = sock_net(skb->sk);
2309 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2310 	int done = cb->args[0];
2311 	int last_addr = cb->args[1];
2312 	struct tipc_node *node;
2313 	struct tipc_nl_msg msg;
2314 
2315 	if (done)
2316 		return 0;
2317 
2318 	msg.skb = skb;
2319 	msg.portid = NETLINK_CB(cb->skb).portid;
2320 	msg.seq = cb->nlh->nlmsg_seq;
2321 
2322 	rcu_read_lock();
2323 	if (last_addr) {
2324 		node = tipc_node_find(net, last_addr);
2325 		if (!node) {
2326 			rcu_read_unlock();
2327 			/* We never set seq or call nl_dump_check_consistent()
2328 			 * this means that setting prev_seq here will cause the
2329 			 * consistence check to fail in the netlink callback
2330 			 * handler. Resulting in the NLMSG_DONE message having
2331 			 * the NLM_F_DUMP_INTR flag set if the node state
2332 			 * changed while we released the lock.
2333 			 */
2334 			cb->prev_seq = 1;
2335 			return -EPIPE;
2336 		}
2337 		tipc_node_put(node);
2338 	}
2339 
2340 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2341 		if (node->preliminary)
2342 			continue;
2343 		if (last_addr) {
2344 			if (node->addr == last_addr)
2345 				last_addr = 0;
2346 			else
2347 				continue;
2348 		}
2349 
2350 		tipc_node_read_lock(node);
2351 		err = __tipc_nl_add_node(&msg, node);
2352 		if (err) {
2353 			last_addr = node->addr;
2354 			tipc_node_read_unlock(node);
2355 			goto out;
2356 		}
2357 
2358 		tipc_node_read_unlock(node);
2359 	}
2360 	done = 1;
2361 out:
2362 	cb->args[0] = done;
2363 	cb->args[1] = last_addr;
2364 	rcu_read_unlock();
2365 
2366 	return skb->len;
2367 }
2368 
2369 /* tipc_node_find_by_name - locate owner node of link by link's name
2370  * @net: the applicable net namespace
2371  * @name: pointer to link name string
2372  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2373  *
2374  * Returns pointer to node owning the link, or 0 if no matching link is found.
2375  */
2376 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2377 						const char *link_name,
2378 						unsigned int *bearer_id)
2379 {
2380 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2381 	struct tipc_link *l;
2382 	struct tipc_node *n;
2383 	struct tipc_node *found_node = NULL;
2384 	int i;
2385 
2386 	*bearer_id = 0;
2387 	rcu_read_lock();
2388 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2389 		tipc_node_read_lock(n);
2390 		for (i = 0; i < MAX_BEARERS; i++) {
2391 			l = n->links[i].link;
2392 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2393 				*bearer_id = i;
2394 				found_node = n;
2395 				break;
2396 			}
2397 		}
2398 		tipc_node_read_unlock(n);
2399 		if (found_node)
2400 			break;
2401 	}
2402 	rcu_read_unlock();
2403 
2404 	return found_node;
2405 }
2406 
2407 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2408 {
2409 	int err;
2410 	int res = 0;
2411 	int bearer_id;
2412 	char *name;
2413 	struct tipc_link *link;
2414 	struct tipc_node *node;
2415 	struct sk_buff_head xmitq;
2416 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2417 	struct net *net = sock_net(skb->sk);
2418 
2419 	__skb_queue_head_init(&xmitq);
2420 
2421 	if (!info->attrs[TIPC_NLA_LINK])
2422 		return -EINVAL;
2423 
2424 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2425 					  info->attrs[TIPC_NLA_LINK],
2426 					  tipc_nl_link_policy, info->extack);
2427 	if (err)
2428 		return err;
2429 
2430 	if (!attrs[TIPC_NLA_LINK_NAME])
2431 		return -EINVAL;
2432 
2433 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2434 
2435 	if (strcmp(name, tipc_bclink_name) == 0)
2436 		return tipc_nl_bc_link_set(net, attrs);
2437 
2438 	node = tipc_node_find_by_name(net, name, &bearer_id);
2439 	if (!node)
2440 		return -EINVAL;
2441 
2442 	tipc_node_read_lock(node);
2443 
2444 	link = node->links[bearer_id].link;
2445 	if (!link) {
2446 		res = -EINVAL;
2447 		goto out;
2448 	}
2449 
2450 	if (attrs[TIPC_NLA_LINK_PROP]) {
2451 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2452 
2453 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
2454 		if (err) {
2455 			res = err;
2456 			goto out;
2457 		}
2458 
2459 		if (props[TIPC_NLA_PROP_TOL]) {
2460 			u32 tol;
2461 
2462 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2463 			tipc_link_set_tolerance(link, tol, &xmitq);
2464 		}
2465 		if (props[TIPC_NLA_PROP_PRIO]) {
2466 			u32 prio;
2467 
2468 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2469 			tipc_link_set_prio(link, prio, &xmitq);
2470 		}
2471 		if (props[TIPC_NLA_PROP_WIN]) {
2472 			u32 max_win;
2473 
2474 			max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2475 			tipc_link_set_queue_limits(link,
2476 						   tipc_link_min_win(link),
2477 						   max_win);
2478 		}
2479 	}
2480 
2481 out:
2482 	tipc_node_read_unlock(node);
2483 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
2484 			 NULL);
2485 	return res;
2486 }
2487 
2488 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2489 {
2490 	struct net *net = genl_info_net(info);
2491 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2492 	struct tipc_nl_msg msg;
2493 	char *name;
2494 	int err;
2495 
2496 	msg.portid = info->snd_portid;
2497 	msg.seq = info->snd_seq;
2498 
2499 	if (!info->attrs[TIPC_NLA_LINK])
2500 		return -EINVAL;
2501 
2502 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2503 					  info->attrs[TIPC_NLA_LINK],
2504 					  tipc_nl_link_policy, info->extack);
2505 	if (err)
2506 		return err;
2507 
2508 	if (!attrs[TIPC_NLA_LINK_NAME])
2509 		return -EINVAL;
2510 
2511 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2512 
2513 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2514 	if (!msg.skb)
2515 		return -ENOMEM;
2516 
2517 	if (strcmp(name, tipc_bclink_name) == 0) {
2518 		err = tipc_nl_add_bc_link(net, &msg, tipc_net(net)->bcl);
2519 		if (err)
2520 			goto err_free;
2521 	} else {
2522 		int bearer_id;
2523 		struct tipc_node *node;
2524 		struct tipc_link *link;
2525 
2526 		node = tipc_node_find_by_name(net, name, &bearer_id);
2527 		if (!node) {
2528 			err = -EINVAL;
2529 			goto err_free;
2530 		}
2531 
2532 		tipc_node_read_lock(node);
2533 		link = node->links[bearer_id].link;
2534 		if (!link) {
2535 			tipc_node_read_unlock(node);
2536 			err = -EINVAL;
2537 			goto err_free;
2538 		}
2539 
2540 		err = __tipc_nl_add_link(net, &msg, link, 0);
2541 		tipc_node_read_unlock(node);
2542 		if (err)
2543 			goto err_free;
2544 	}
2545 
2546 	return genlmsg_reply(msg.skb, info);
2547 
2548 err_free:
2549 	nlmsg_free(msg.skb);
2550 	return err;
2551 }
2552 
2553 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2554 {
2555 	int err;
2556 	char *link_name;
2557 	unsigned int bearer_id;
2558 	struct tipc_link *link;
2559 	struct tipc_node *node;
2560 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2561 	struct net *net = sock_net(skb->sk);
2562 	struct tipc_net *tn = tipc_net(net);
2563 	struct tipc_link_entry *le;
2564 
2565 	if (!info->attrs[TIPC_NLA_LINK])
2566 		return -EINVAL;
2567 
2568 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2569 					  info->attrs[TIPC_NLA_LINK],
2570 					  tipc_nl_link_policy, info->extack);
2571 	if (err)
2572 		return err;
2573 
2574 	if (!attrs[TIPC_NLA_LINK_NAME])
2575 		return -EINVAL;
2576 
2577 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2578 
2579 	err = -EINVAL;
2580 	if (!strcmp(link_name, tipc_bclink_name)) {
2581 		err = tipc_bclink_reset_stats(net, tipc_bc_sndlink(net));
2582 		if (err)
2583 			return err;
2584 		return 0;
2585 	} else if (strstr(link_name, tipc_bclink_name)) {
2586 		rcu_read_lock();
2587 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2588 			tipc_node_read_lock(node);
2589 			link = node->bc_entry.link;
2590 			if (link && !strcmp(link_name, tipc_link_name(link))) {
2591 				err = tipc_bclink_reset_stats(net, link);
2592 				tipc_node_read_unlock(node);
2593 				break;
2594 			}
2595 			tipc_node_read_unlock(node);
2596 		}
2597 		rcu_read_unlock();
2598 		return err;
2599 	}
2600 
2601 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2602 	if (!node)
2603 		return -EINVAL;
2604 
2605 	le = &node->links[bearer_id];
2606 	tipc_node_read_lock(node);
2607 	spin_lock_bh(&le->lock);
2608 	link = node->links[bearer_id].link;
2609 	if (!link) {
2610 		spin_unlock_bh(&le->lock);
2611 		tipc_node_read_unlock(node);
2612 		return -EINVAL;
2613 	}
2614 	tipc_link_reset_stats(link);
2615 	spin_unlock_bh(&le->lock);
2616 	tipc_node_read_unlock(node);
2617 	return 0;
2618 }
2619 
2620 /* Caller should hold node lock  */
2621 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2622 				    struct tipc_node *node, u32 *prev_link,
2623 				    bool bc_link)
2624 {
2625 	u32 i;
2626 	int err;
2627 
2628 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2629 		*prev_link = i;
2630 
2631 		if (!node->links[i].link)
2632 			continue;
2633 
2634 		err = __tipc_nl_add_link(net, msg,
2635 					 node->links[i].link, NLM_F_MULTI);
2636 		if (err)
2637 			return err;
2638 	}
2639 
2640 	if (bc_link) {
2641 		*prev_link = i;
2642 		err = tipc_nl_add_bc_link(net, msg, node->bc_entry.link);
2643 		if (err)
2644 			return err;
2645 	}
2646 
2647 	*prev_link = 0;
2648 
2649 	return 0;
2650 }
2651 
2652 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2653 {
2654 	struct net *net = sock_net(skb->sk);
2655 	struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2656 	struct nlattr *link[TIPC_NLA_LINK_MAX + 1];
2657 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2658 	struct tipc_node *node;
2659 	struct tipc_nl_msg msg;
2660 	u32 prev_node = cb->args[0];
2661 	u32 prev_link = cb->args[1];
2662 	int done = cb->args[2];
2663 	bool bc_link = cb->args[3];
2664 	int err;
2665 
2666 	if (done)
2667 		return 0;
2668 
2669 	if (!prev_node) {
2670 		/* Check if broadcast-receiver links dumping is needed */
2671 		if (attrs && attrs[TIPC_NLA_LINK]) {
2672 			err = nla_parse_nested_deprecated(link,
2673 							  TIPC_NLA_LINK_MAX,
2674 							  attrs[TIPC_NLA_LINK],
2675 							  tipc_nl_link_policy,
2676 							  NULL);
2677 			if (unlikely(err))
2678 				return err;
2679 			if (unlikely(!link[TIPC_NLA_LINK_BROADCAST]))
2680 				return -EINVAL;
2681 			bc_link = true;
2682 		}
2683 	}
2684 
2685 	msg.skb = skb;
2686 	msg.portid = NETLINK_CB(cb->skb).portid;
2687 	msg.seq = cb->nlh->nlmsg_seq;
2688 
2689 	rcu_read_lock();
2690 	if (prev_node) {
2691 		node = tipc_node_find(net, prev_node);
2692 		if (!node) {
2693 			/* We never set seq or call nl_dump_check_consistent()
2694 			 * this means that setting prev_seq here will cause the
2695 			 * consistence check to fail in the netlink callback
2696 			 * handler. Resulting in the last NLMSG_DONE message
2697 			 * having the NLM_F_DUMP_INTR flag set.
2698 			 */
2699 			cb->prev_seq = 1;
2700 			goto out;
2701 		}
2702 		tipc_node_put(node);
2703 
2704 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2705 						 list) {
2706 			tipc_node_read_lock(node);
2707 			err = __tipc_nl_add_node_links(net, &msg, node,
2708 						       &prev_link, bc_link);
2709 			tipc_node_read_unlock(node);
2710 			if (err)
2711 				goto out;
2712 
2713 			prev_node = node->addr;
2714 		}
2715 	} else {
2716 		err = tipc_nl_add_bc_link(net, &msg, tn->bcl);
2717 		if (err)
2718 			goto out;
2719 
2720 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2721 			tipc_node_read_lock(node);
2722 			err = __tipc_nl_add_node_links(net, &msg, node,
2723 						       &prev_link, bc_link);
2724 			tipc_node_read_unlock(node);
2725 			if (err)
2726 				goto out;
2727 
2728 			prev_node = node->addr;
2729 		}
2730 	}
2731 	done = 1;
2732 out:
2733 	rcu_read_unlock();
2734 
2735 	cb->args[0] = prev_node;
2736 	cb->args[1] = prev_link;
2737 	cb->args[2] = done;
2738 	cb->args[3] = bc_link;
2739 
2740 	return skb->len;
2741 }
2742 
2743 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2744 {
2745 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2746 	struct net *net = sock_net(skb->sk);
2747 	int err;
2748 
2749 	if (!info->attrs[TIPC_NLA_MON])
2750 		return -EINVAL;
2751 
2752 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2753 					  info->attrs[TIPC_NLA_MON],
2754 					  tipc_nl_monitor_policy,
2755 					  info->extack);
2756 	if (err)
2757 		return err;
2758 
2759 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2760 		u32 val;
2761 
2762 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2763 		err = tipc_nl_monitor_set_threshold(net, val);
2764 		if (err)
2765 			return err;
2766 	}
2767 
2768 	return 0;
2769 }
2770 
2771 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2772 {
2773 	struct nlattr *attrs;
2774 	void *hdr;
2775 	u32 val;
2776 
2777 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2778 			  0, TIPC_NL_MON_GET);
2779 	if (!hdr)
2780 		return -EMSGSIZE;
2781 
2782 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2783 	if (!attrs)
2784 		goto msg_full;
2785 
2786 	val = tipc_nl_monitor_get_threshold(net);
2787 
2788 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2789 		goto attr_msg_full;
2790 
2791 	nla_nest_end(msg->skb, attrs);
2792 	genlmsg_end(msg->skb, hdr);
2793 
2794 	return 0;
2795 
2796 attr_msg_full:
2797 	nla_nest_cancel(msg->skb, attrs);
2798 msg_full:
2799 	genlmsg_cancel(msg->skb, hdr);
2800 
2801 	return -EMSGSIZE;
2802 }
2803 
2804 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2805 {
2806 	struct net *net = sock_net(skb->sk);
2807 	struct tipc_nl_msg msg;
2808 	int err;
2809 
2810 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2811 	if (!msg.skb)
2812 		return -ENOMEM;
2813 	msg.portid = info->snd_portid;
2814 	msg.seq = info->snd_seq;
2815 
2816 	err = __tipc_nl_add_monitor_prop(net, &msg);
2817 	if (err) {
2818 		nlmsg_free(msg.skb);
2819 		return err;
2820 	}
2821 
2822 	return genlmsg_reply(msg.skb, info);
2823 }
2824 
2825 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2826 {
2827 	struct net *net = sock_net(skb->sk);
2828 	u32 prev_bearer = cb->args[0];
2829 	struct tipc_nl_msg msg;
2830 	int bearer_id;
2831 	int err;
2832 
2833 	if (prev_bearer == MAX_BEARERS)
2834 		return 0;
2835 
2836 	msg.skb = skb;
2837 	msg.portid = NETLINK_CB(cb->skb).portid;
2838 	msg.seq = cb->nlh->nlmsg_seq;
2839 
2840 	rtnl_lock();
2841 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2842 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2843 		if (err)
2844 			break;
2845 	}
2846 	rtnl_unlock();
2847 	cb->args[0] = bearer_id;
2848 
2849 	return skb->len;
2850 }
2851 
2852 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2853 				   struct netlink_callback *cb)
2854 {
2855 	struct net *net = sock_net(skb->sk);
2856 	u32 prev_node = cb->args[1];
2857 	u32 bearer_id = cb->args[2];
2858 	int done = cb->args[0];
2859 	struct tipc_nl_msg msg;
2860 	int err;
2861 
2862 	if (!prev_node) {
2863 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2864 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2865 
2866 		if (!attrs[TIPC_NLA_MON])
2867 			return -EINVAL;
2868 
2869 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2870 						  attrs[TIPC_NLA_MON],
2871 						  tipc_nl_monitor_policy,
2872 						  NULL);
2873 		if (err)
2874 			return err;
2875 
2876 		if (!mon[TIPC_NLA_MON_REF])
2877 			return -EINVAL;
2878 
2879 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2880 
2881 		if (bearer_id >= MAX_BEARERS)
2882 			return -EINVAL;
2883 	}
2884 
2885 	if (done)
2886 		return 0;
2887 
2888 	msg.skb = skb;
2889 	msg.portid = NETLINK_CB(cb->skb).portid;
2890 	msg.seq = cb->nlh->nlmsg_seq;
2891 
2892 	rtnl_lock();
2893 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2894 	if (!err)
2895 		done = 1;
2896 
2897 	rtnl_unlock();
2898 	cb->args[0] = done;
2899 	cb->args[1] = prev_node;
2900 	cb->args[2] = bearer_id;
2901 
2902 	return skb->len;
2903 }
2904 
2905 #ifdef CONFIG_TIPC_CRYPTO
2906 static int tipc_nl_retrieve_key(struct nlattr **attrs,
2907 				struct tipc_aead_key **pkey)
2908 {
2909 	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
2910 	struct tipc_aead_key *key;
2911 
2912 	if (!attr)
2913 		return -ENODATA;
2914 
2915 	if (nla_len(attr) < sizeof(*key))
2916 		return -EINVAL;
2917 	key = (struct tipc_aead_key *)nla_data(attr);
2918 	if (key->keylen > TIPC_AEAD_KEYLEN_MAX ||
2919 	    nla_len(attr) < tipc_aead_key_size(key))
2920 		return -EINVAL;
2921 
2922 	*pkey = key;
2923 	return 0;
2924 }
2925 
2926 static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
2927 {
2928 	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
2929 
2930 	if (!attr)
2931 		return -ENODATA;
2932 
2933 	if (nla_len(attr) < TIPC_NODEID_LEN)
2934 		return -EINVAL;
2935 
2936 	*node_id = (u8 *)nla_data(attr);
2937 	return 0;
2938 }
2939 
2940 static int tipc_nl_retrieve_rekeying(struct nlattr **attrs, u32 *intv)
2941 {
2942 	struct nlattr *attr = attrs[TIPC_NLA_NODE_REKEYING];
2943 
2944 	if (!attr)
2945 		return -ENODATA;
2946 
2947 	*intv = nla_get_u32(attr);
2948 	return 0;
2949 }
2950 
2951 static int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2952 {
2953 	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
2954 	struct net *net = sock_net(skb->sk);
2955 	struct tipc_crypto *tx = tipc_net(net)->crypto_tx, *c = tx;
2956 	struct tipc_node *n = NULL;
2957 	struct tipc_aead_key *ukey;
2958 	bool rekeying = true, master_key = false;
2959 	u8 *id, *own_id, mode;
2960 	u32 intv = 0;
2961 	int rc = 0;
2962 
2963 	if (!info->attrs[TIPC_NLA_NODE])
2964 		return -EINVAL;
2965 
2966 	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
2967 			      info->attrs[TIPC_NLA_NODE],
2968 			      tipc_nl_node_policy, info->extack);
2969 	if (rc)
2970 		return rc;
2971 
2972 	own_id = tipc_own_id(net);
2973 	if (!own_id) {
2974 		GENL_SET_ERR_MSG(info, "not found own node identity (set id?)");
2975 		return -EPERM;
2976 	}
2977 
2978 	rc = tipc_nl_retrieve_rekeying(attrs, &intv);
2979 	if (rc == -ENODATA)
2980 		rekeying = false;
2981 
2982 	rc = tipc_nl_retrieve_key(attrs, &ukey);
2983 	if (rc == -ENODATA && rekeying)
2984 		goto rekeying;
2985 	else if (rc)
2986 		return rc;
2987 
2988 	rc = tipc_aead_key_validate(ukey, info);
2989 	if (rc)
2990 		return rc;
2991 
2992 	rc = tipc_nl_retrieve_nodeid(attrs, &id);
2993 	switch (rc) {
2994 	case -ENODATA:
2995 		mode = CLUSTER_KEY;
2996 		master_key = !!(attrs[TIPC_NLA_NODE_KEY_MASTER]);
2997 		break;
2998 	case 0:
2999 		mode = PER_NODE_KEY;
3000 		if (memcmp(id, own_id, NODE_ID_LEN)) {
3001 			n = tipc_node_find_by_id(net, id) ?:
3002 				tipc_node_create(net, 0, id, 0xffffu, 0, true);
3003 			if (unlikely(!n))
3004 				return -ENOMEM;
3005 			c = n->crypto_rx;
3006 		}
3007 		break;
3008 	default:
3009 		return rc;
3010 	}
3011 
3012 	/* Initiate the TX/RX key */
3013 	rc = tipc_crypto_key_init(c, ukey, mode, master_key);
3014 	if (n)
3015 		tipc_node_put(n);
3016 
3017 	if (unlikely(rc < 0)) {
3018 		GENL_SET_ERR_MSG(info, "unable to initiate or attach new key");
3019 		return rc;
3020 	} else if (c == tx) {
3021 		/* Distribute TX key but not master one */
3022 		if (!master_key && tipc_crypto_key_distr(tx, rc, NULL))
3023 			GENL_SET_ERR_MSG(info, "failed to replicate new key");
3024 rekeying:
3025 		/* Schedule TX rekeying if needed */
3026 		tipc_crypto_rekeying_sched(tx, rekeying, intv);
3027 	}
3028 
3029 	return 0;
3030 }
3031 
3032 int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
3033 {
3034 	int err;
3035 
3036 	rtnl_lock();
3037 	err = __tipc_nl_node_set_key(skb, info);
3038 	rtnl_unlock();
3039 
3040 	return err;
3041 }
3042 
3043 static int __tipc_nl_node_flush_key(struct sk_buff *skb,
3044 				    struct genl_info *info)
3045 {
3046 	struct net *net = sock_net(skb->sk);
3047 	struct tipc_net *tn = tipc_net(net);
3048 	struct tipc_node *n;
3049 
3050 	tipc_crypto_key_flush(tn->crypto_tx);
3051 	rcu_read_lock();
3052 	list_for_each_entry_rcu(n, &tn->node_list, list)
3053 		tipc_crypto_key_flush(n->crypto_rx);
3054 	rcu_read_unlock();
3055 
3056 	return 0;
3057 }
3058 
3059 int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
3060 {
3061 	int err;
3062 
3063 	rtnl_lock();
3064 	err = __tipc_nl_node_flush_key(skb, info);
3065 	rtnl_unlock();
3066 
3067 	return err;
3068 }
3069 #endif
3070 
3071 /**
3072  * tipc_node_dump - dump TIPC node data
3073  * @n: tipc node to be dumped
3074  * @more: dump more?
3075  *        - false: dump only tipc node data
3076  *        - true: dump node link data as well
3077  * @buf: returned buffer of dump data in format
3078  */
3079 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
3080 {
3081 	int i = 0;
3082 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
3083 
3084 	if (!n) {
3085 		i += scnprintf(buf, sz, "node data: (null)\n");
3086 		return i;
3087 	}
3088 
3089 	i += scnprintf(buf, sz, "node data: %x", n->addr);
3090 	i += scnprintf(buf + i, sz - i, " %x", n->state);
3091 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
3092 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
3093 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
3094 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
3095 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
3096 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
3097 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
3098 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
3099 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
3100 
3101 	if (!more)
3102 		return i;
3103 
3104 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
3105 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
3106 	i += scnprintf(buf + i, sz - i, " media: ");
3107 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
3108 	i += scnprintf(buf + i, sz - i, "\n");
3109 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
3110 	i += scnprintf(buf + i, sz - i, " inputq: ");
3111 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
3112 
3113 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
3114 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
3115 	i += scnprintf(buf + i, sz - i, " media: ");
3116 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
3117 	i += scnprintf(buf + i, sz - i, "\n");
3118 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
3119 	i += scnprintf(buf + i, sz - i, " inputq: ");
3120 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
3121 
3122 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
3123 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
3124 
3125 	return i;
3126 }
3127 
3128 void tipc_node_pre_cleanup_net(struct net *exit_net)
3129 {
3130 	struct tipc_node *n;
3131 	struct tipc_net *tn;
3132 	struct net *tmp;
3133 
3134 	rcu_read_lock();
3135 	for_each_net_rcu(tmp) {
3136 		if (tmp == exit_net)
3137 			continue;
3138 		tn = tipc_net(tmp);
3139 		if (!tn)
3140 			continue;
3141 		spin_lock_bh(&tn->node_list_lock);
3142 		list_for_each_entry_rcu(n, &tn->node_list, list) {
3143 			if (!n->peer_net)
3144 				continue;
3145 			if (n->peer_net != exit_net)
3146 				continue;
3147 			tipc_node_write_lock(n);
3148 			n->peer_net = NULL;
3149 			n->peer_hash_mix = 0;
3150 			tipc_node_write_unlock_fast(n);
3151 			break;
3152 		}
3153 		spin_unlock_bh(&tn->node_list_lock);
3154 	}
3155 	rcu_read_unlock();
3156 }
3157