xref: /openbmc/linux/net/tipc/node.c (revision d23015c1)
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 };
79 
80 /**
81  * struct tipc_node - TIPC node structure
82  * @addr: network address of node
83  * @ref: reference counter to node object
84  * @lock: rwlock governing access to structure
85  * @net: the applicable net namespace
86  * @hash: links to adjacent nodes in unsorted hash chain
87  * @inputq: pointer to input queue containing messages for msg event
88  * @namedq: pointer to name table input queue with name table messages
89  * @active_links: bearer ids of active links, used as index into links[] array
90  * @links: array containing references to all links to node
91  * @action_flags: bit mask of different types of node actions
92  * @state: connectivity state vs peer node
93  * @preliminary: a preliminary node or not
94  * @sync_point: sequence number where synch/failover is finished
95  * @list: links to adjacent nodes in sorted list of cluster's nodes
96  * @working_links: number of working links to node (both active and standby)
97  * @link_cnt: number of links to node
98  * @capabilities: bitmap, indicating peer node's functional capabilities
99  * @signature: node instance identifier
100  * @link_id: local and remote bearer ids of changing link, if any
101  * @publ_list: list of publications
102  * @rcu: rcu struct for tipc_node
103  * @delete_at: indicates the time for deleting a down node
104  * @crypto_rx: RX crypto handler
105  */
106 struct tipc_node {
107 	u32 addr;
108 	struct kref kref;
109 	rwlock_t lock;
110 	struct net *net;
111 	struct hlist_node hash;
112 	int active_links[2];
113 	struct tipc_link_entry links[MAX_BEARERS];
114 	struct tipc_bclink_entry bc_entry;
115 	int action_flags;
116 	struct list_head list;
117 	int state;
118 	bool preliminary;
119 	bool failover_sent;
120 	u16 sync_point;
121 	int link_cnt;
122 	u16 working_links;
123 	u16 capabilities;
124 	u32 signature;
125 	u32 link_id;
126 	u8 peer_id[16];
127 	char peer_id_string[NODE_ID_STR_LEN];
128 	struct list_head publ_list;
129 	struct list_head conn_sks;
130 	unsigned long keepalive_intv;
131 	struct timer_list timer;
132 	struct rcu_head rcu;
133 	unsigned long delete_at;
134 	struct net *peer_net;
135 	u32 peer_hash_mix;
136 #ifdef CONFIG_TIPC_CRYPTO
137 	struct tipc_crypto *crypto_rx;
138 #endif
139 };
140 
141 /* Node FSM states and events:
142  */
143 enum {
144 	SELF_DOWN_PEER_DOWN    = 0xdd,
145 	SELF_UP_PEER_UP        = 0xaa,
146 	SELF_DOWN_PEER_LEAVING = 0xd1,
147 	SELF_UP_PEER_COMING    = 0xac,
148 	SELF_COMING_PEER_UP    = 0xca,
149 	SELF_LEAVING_PEER_DOWN = 0x1d,
150 	NODE_FAILINGOVER       = 0xf0,
151 	NODE_SYNCHING          = 0xcc
152 };
153 
154 enum {
155 	SELF_ESTABL_CONTACT_EVT = 0xece,
156 	SELF_LOST_CONTACT_EVT   = 0x1ce,
157 	PEER_ESTABL_CONTACT_EVT = 0x9ece,
158 	PEER_LOST_CONTACT_EVT   = 0x91ce,
159 	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
160 	NODE_FAILOVER_END_EVT   = 0xfee,
161 	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
162 	NODE_SYNCH_END_EVT      = 0xcee
163 };
164 
165 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
166 				  struct sk_buff_head *xmitq,
167 				  struct tipc_media_addr **maddr);
168 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
169 				bool delete);
170 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
171 static void tipc_node_delete(struct tipc_node *node);
172 static void tipc_node_timeout(struct timer_list *t);
173 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
174 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
175 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
176 static bool node_is_up(struct tipc_node *n);
177 static void tipc_node_delete_from_list(struct tipc_node *node);
178 
179 struct tipc_sock_conn {
180 	u32 port;
181 	u32 peer_port;
182 	u32 peer_node;
183 	struct list_head list;
184 };
185 
186 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
187 {
188 	int bearer_id = n->active_links[sel & 1];
189 
190 	if (unlikely(bearer_id == INVALID_BEARER_ID))
191 		return NULL;
192 
193 	return n->links[bearer_id].link;
194 }
195 
196 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel, bool connected)
197 {
198 	struct tipc_node *n;
199 	int bearer_id;
200 	unsigned int mtu = MAX_MSG_SIZE;
201 
202 	n = tipc_node_find(net, addr);
203 	if (unlikely(!n))
204 		return mtu;
205 
206 	/* Allow MAX_MSG_SIZE when building connection oriented message
207 	 * if they are in the same core network
208 	 */
209 	if (n->peer_net && connected) {
210 		tipc_node_put(n);
211 		return mtu;
212 	}
213 
214 	bearer_id = n->active_links[sel & 1];
215 	if (likely(bearer_id != INVALID_BEARER_ID))
216 		mtu = n->links[bearer_id].mtu;
217 	tipc_node_put(n);
218 	return mtu;
219 }
220 
221 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
222 {
223 	u8 *own_id = tipc_own_id(net);
224 	struct tipc_node *n;
225 
226 	if (!own_id)
227 		return true;
228 
229 	if (addr == tipc_own_addr(net)) {
230 		memcpy(id, own_id, TIPC_NODEID_LEN);
231 		return true;
232 	}
233 	n = tipc_node_find(net, addr);
234 	if (!n)
235 		return false;
236 
237 	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
238 	tipc_node_put(n);
239 	return true;
240 }
241 
242 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
243 {
244 	struct tipc_node *n;
245 	u16 caps;
246 
247 	n = tipc_node_find(net, addr);
248 	if (unlikely(!n))
249 		return TIPC_NODE_CAPABILITIES;
250 	caps = n->capabilities;
251 	tipc_node_put(n);
252 	return caps;
253 }
254 
255 u32 tipc_node_get_addr(struct tipc_node *node)
256 {
257 	return (node) ? node->addr : 0;
258 }
259 
260 char *tipc_node_get_id_str(struct tipc_node *node)
261 {
262 	return node->peer_id_string;
263 }
264 
265 #ifdef CONFIG_TIPC_CRYPTO
266 /**
267  * tipc_node_crypto_rx - Retrieve crypto RX handle from node
268  * Note: node ref counter must be held first!
269  */
270 struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n)
271 {
272 	return (__n) ? __n->crypto_rx : NULL;
273 }
274 
275 struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos)
276 {
277 	return container_of(pos, struct tipc_node, list)->crypto_rx;
278 }
279 #endif
280 
281 void tipc_node_free(struct rcu_head *rp)
282 {
283 	struct tipc_node *n = container_of(rp, struct tipc_node, rcu);
284 
285 #ifdef CONFIG_TIPC_CRYPTO
286 	tipc_crypto_stop(&n->crypto_rx);
287 #endif
288 	kfree(n);
289 }
290 
291 static void tipc_node_kref_release(struct kref *kref)
292 {
293 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
294 
295 	kfree(n->bc_entry.link);
296 	call_rcu(&n->rcu, tipc_node_free);
297 }
298 
299 void tipc_node_put(struct tipc_node *node)
300 {
301 	kref_put(&node->kref, tipc_node_kref_release);
302 }
303 
304 static void tipc_node_get(struct tipc_node *node)
305 {
306 	kref_get(&node->kref);
307 }
308 
309 /*
310  * tipc_node_find - locate specified node object, if it exists
311  */
312 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
313 {
314 	struct tipc_net *tn = tipc_net(net);
315 	struct tipc_node *node;
316 	unsigned int thash = tipc_hashfn(addr);
317 
318 	rcu_read_lock();
319 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
320 		if (node->addr != addr || node->preliminary)
321 			continue;
322 		if (!kref_get_unless_zero(&node->kref))
323 			node = NULL;
324 		break;
325 	}
326 	rcu_read_unlock();
327 	return node;
328 }
329 
330 /* tipc_node_find_by_id - locate specified node object by its 128-bit id
331  * Note: this function is called only when a discovery request failed
332  * to find the node by its 32-bit id, and is not time critical
333  */
334 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
335 {
336 	struct tipc_net *tn = tipc_net(net);
337 	struct tipc_node *n;
338 	bool found = false;
339 
340 	rcu_read_lock();
341 	list_for_each_entry_rcu(n, &tn->node_list, list) {
342 		read_lock_bh(&n->lock);
343 		if (!memcmp(id, n->peer_id, 16) &&
344 		    kref_get_unless_zero(&n->kref))
345 			found = true;
346 		read_unlock_bh(&n->lock);
347 		if (found)
348 			break;
349 	}
350 	rcu_read_unlock();
351 	return found ? n : NULL;
352 }
353 
354 static void tipc_node_read_lock(struct tipc_node *n)
355 {
356 	read_lock_bh(&n->lock);
357 }
358 
359 static void tipc_node_read_unlock(struct tipc_node *n)
360 {
361 	read_unlock_bh(&n->lock);
362 }
363 
364 static void tipc_node_write_lock(struct tipc_node *n)
365 {
366 	write_lock_bh(&n->lock);
367 }
368 
369 static void tipc_node_write_unlock_fast(struct tipc_node *n)
370 {
371 	write_unlock_bh(&n->lock);
372 }
373 
374 static void tipc_node_write_unlock(struct tipc_node *n)
375 {
376 	struct net *net = n->net;
377 	u32 addr = 0;
378 	u32 flags = n->action_flags;
379 	u32 link_id = 0;
380 	u32 bearer_id;
381 	struct list_head *publ_list;
382 
383 	if (likely(!flags)) {
384 		write_unlock_bh(&n->lock);
385 		return;
386 	}
387 
388 	addr = n->addr;
389 	link_id = n->link_id;
390 	bearer_id = link_id & 0xffff;
391 	publ_list = &n->publ_list;
392 
393 	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
394 			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
395 
396 	write_unlock_bh(&n->lock);
397 
398 	if (flags & TIPC_NOTIFY_NODE_DOWN)
399 		tipc_publ_notify(net, publ_list, addr);
400 
401 	if (flags & TIPC_NOTIFY_NODE_UP)
402 		tipc_named_node_up(net, addr);
403 
404 	if (flags & TIPC_NOTIFY_LINK_UP) {
405 		tipc_mon_peer_up(net, addr, bearer_id);
406 		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
407 				     TIPC_NODE_SCOPE, link_id, link_id);
408 	}
409 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
410 		tipc_mon_peer_down(net, addr, bearer_id);
411 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
412 				      addr, link_id);
413 	}
414 }
415 
416 static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
417 {
418 	int net_id = tipc_netid(n->net);
419 	struct tipc_net *tn_peer;
420 	struct net *tmp;
421 	u32 hash_chk;
422 
423 	if (n->peer_net)
424 		return;
425 
426 	for_each_net_rcu(tmp) {
427 		tn_peer = tipc_net(tmp);
428 		if (!tn_peer)
429 			continue;
430 		/* Integrity checking whether node exists in namespace or not */
431 		if (tn_peer->net_id != net_id)
432 			continue;
433 		if (memcmp(n->peer_id, tn_peer->node_id, NODE_ID_LEN))
434 			continue;
435 		hash_chk = tipc_net_hash_mixes(tmp, tn_peer->random);
436 		if (hash_mixes ^ hash_chk)
437 			continue;
438 		n->peer_net = tmp;
439 		n->peer_hash_mix = hash_mixes;
440 		break;
441 	}
442 }
443 
444 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
445 				   u16 capabilities, u32 hash_mixes,
446 				   bool preliminary)
447 {
448 	struct tipc_net *tn = net_generic(net, tipc_net_id);
449 	struct tipc_node *n, *temp_node;
450 	struct tipc_link *l;
451 	unsigned long intv;
452 	int bearer_id;
453 	int i;
454 
455 	spin_lock_bh(&tn->node_list_lock);
456 	n = tipc_node_find(net, addr) ?:
457 		tipc_node_find_by_id(net, peer_id);
458 	if (n) {
459 		if (!n->preliminary)
460 			goto update;
461 		if (preliminary)
462 			goto exit;
463 		/* A preliminary node becomes "real" now, refresh its data */
464 		tipc_node_write_lock(n);
465 		n->preliminary = false;
466 		n->addr = addr;
467 		hlist_del_rcu(&n->hash);
468 		hlist_add_head_rcu(&n->hash,
469 				   &tn->node_htable[tipc_hashfn(addr)]);
470 		list_del_rcu(&n->list);
471 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
472 			if (n->addr < temp_node->addr)
473 				break;
474 		}
475 		list_add_tail_rcu(&n->list, &temp_node->list);
476 		tipc_node_write_unlock_fast(n);
477 
478 update:
479 		if (n->peer_hash_mix ^ hash_mixes)
480 			tipc_node_assign_peer_net(n, hash_mixes);
481 		if (n->capabilities == capabilities)
482 			goto exit;
483 		/* Same node may come back with new capabilities */
484 		tipc_node_write_lock(n);
485 		n->capabilities = capabilities;
486 		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
487 			l = n->links[bearer_id].link;
488 			if (l)
489 				tipc_link_update_caps(l, capabilities);
490 		}
491 		tipc_node_write_unlock_fast(n);
492 
493 		/* Calculate cluster capabilities */
494 		tn->capabilities = TIPC_NODE_CAPABILITIES;
495 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
496 			tn->capabilities &= temp_node->capabilities;
497 		}
498 
499 		tipc_bcast_toggle_rcast(net,
500 					(tn->capabilities & TIPC_BCAST_RCAST));
501 
502 		goto exit;
503 	}
504 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
505 	if (!n) {
506 		pr_warn("Node creation failed, no memory\n");
507 		goto exit;
508 	}
509 	tipc_nodeid2string(n->peer_id_string, peer_id);
510 #ifdef CONFIG_TIPC_CRYPTO
511 	if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
512 		pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
513 		kfree(n);
514 		n = NULL;
515 		goto exit;
516 	}
517 #endif
518 	n->addr = addr;
519 	n->preliminary = preliminary;
520 	memcpy(&n->peer_id, peer_id, 16);
521 	n->net = net;
522 	n->peer_net = NULL;
523 	n->peer_hash_mix = 0;
524 	/* Assign kernel local namespace if exists */
525 	tipc_node_assign_peer_net(n, hash_mixes);
526 	n->capabilities = capabilities;
527 	kref_init(&n->kref);
528 	rwlock_init(&n->lock);
529 	INIT_HLIST_NODE(&n->hash);
530 	INIT_LIST_HEAD(&n->list);
531 	INIT_LIST_HEAD(&n->publ_list);
532 	INIT_LIST_HEAD(&n->conn_sks);
533 	skb_queue_head_init(&n->bc_entry.namedq);
534 	skb_queue_head_init(&n->bc_entry.inputq1);
535 	__skb_queue_head_init(&n->bc_entry.arrvq);
536 	skb_queue_head_init(&n->bc_entry.inputq2);
537 	for (i = 0; i < MAX_BEARERS; i++)
538 		spin_lock_init(&n->links[i].lock);
539 	n->state = SELF_DOWN_PEER_LEAVING;
540 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
541 	n->signature = INVALID_NODE_SIG;
542 	n->active_links[0] = INVALID_BEARER_ID;
543 	n->active_links[1] = INVALID_BEARER_ID;
544 	n->bc_entry.link = NULL;
545 	tipc_node_get(n);
546 	timer_setup(&n->timer, tipc_node_timeout, 0);
547 	/* Start a slow timer anyway, crypto needs it */
548 	n->keepalive_intv = 10000;
549 	intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
550 	if (!mod_timer(&n->timer, intv))
551 		tipc_node_get(n);
552 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
553 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
554 		if (n->addr < temp_node->addr)
555 			break;
556 	}
557 	list_add_tail_rcu(&n->list, &temp_node->list);
558 	/* Calculate cluster capabilities */
559 	tn->capabilities = TIPC_NODE_CAPABILITIES;
560 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
561 		tn->capabilities &= temp_node->capabilities;
562 	}
563 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
564 	trace_tipc_node_create(n, true, " ");
565 exit:
566 	spin_unlock_bh(&tn->node_list_lock);
567 	return n;
568 }
569 
570 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
571 {
572 	unsigned long tol = tipc_link_tolerance(l);
573 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
574 
575 	/* Link with lowest tolerance determines timer interval */
576 	if (intv < n->keepalive_intv)
577 		n->keepalive_intv = intv;
578 
579 	/* Ensure link's abort limit corresponds to current tolerance */
580 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
581 }
582 
583 static void tipc_node_delete_from_list(struct tipc_node *node)
584 {
585 	list_del_rcu(&node->list);
586 	hlist_del_rcu(&node->hash);
587 	tipc_node_put(node);
588 }
589 
590 static void tipc_node_delete(struct tipc_node *node)
591 {
592 	trace_tipc_node_delete(node, true, " ");
593 	tipc_node_delete_from_list(node);
594 
595 	del_timer_sync(&node->timer);
596 	tipc_node_put(node);
597 }
598 
599 void tipc_node_stop(struct net *net)
600 {
601 	struct tipc_net *tn = tipc_net(net);
602 	struct tipc_node *node, *t_node;
603 
604 	spin_lock_bh(&tn->node_list_lock);
605 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
606 		tipc_node_delete(node);
607 	spin_unlock_bh(&tn->node_list_lock);
608 }
609 
610 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
611 {
612 	struct tipc_node *n;
613 
614 	if (in_own_node(net, addr))
615 		return;
616 
617 	n = tipc_node_find(net, addr);
618 	if (!n) {
619 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
620 		return;
621 	}
622 	tipc_node_write_lock(n);
623 	list_add_tail(subscr, &n->publ_list);
624 	tipc_node_write_unlock_fast(n);
625 	tipc_node_put(n);
626 }
627 
628 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
629 {
630 	struct tipc_node *n;
631 
632 	if (in_own_node(net, addr))
633 		return;
634 
635 	n = tipc_node_find(net, addr);
636 	if (!n) {
637 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
638 		return;
639 	}
640 	tipc_node_write_lock(n);
641 	list_del_init(subscr);
642 	tipc_node_write_unlock_fast(n);
643 	tipc_node_put(n);
644 }
645 
646 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
647 {
648 	struct tipc_node *node;
649 	struct tipc_sock_conn *conn;
650 	int err = 0;
651 
652 	if (in_own_node(net, dnode))
653 		return 0;
654 
655 	node = tipc_node_find(net, dnode);
656 	if (!node) {
657 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
658 		return -EHOSTUNREACH;
659 	}
660 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
661 	if (!conn) {
662 		err = -EHOSTUNREACH;
663 		goto exit;
664 	}
665 	conn->peer_node = dnode;
666 	conn->port = port;
667 	conn->peer_port = peer_port;
668 
669 	tipc_node_write_lock(node);
670 	list_add_tail(&conn->list, &node->conn_sks);
671 	tipc_node_write_unlock(node);
672 exit:
673 	tipc_node_put(node);
674 	return err;
675 }
676 
677 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
678 {
679 	struct tipc_node *node;
680 	struct tipc_sock_conn *conn, *safe;
681 
682 	if (in_own_node(net, dnode))
683 		return;
684 
685 	node = tipc_node_find(net, dnode);
686 	if (!node)
687 		return;
688 
689 	tipc_node_write_lock(node);
690 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
691 		if (port != conn->port)
692 			continue;
693 		list_del(&conn->list);
694 		kfree(conn);
695 	}
696 	tipc_node_write_unlock(node);
697 	tipc_node_put(node);
698 }
699 
700 static void  tipc_node_clear_links(struct tipc_node *node)
701 {
702 	int i;
703 
704 	for (i = 0; i < MAX_BEARERS; i++) {
705 		struct tipc_link_entry *le = &node->links[i];
706 
707 		if (le->link) {
708 			kfree(le->link);
709 			le->link = NULL;
710 			node->link_cnt--;
711 		}
712 	}
713 }
714 
715 /* tipc_node_cleanup - delete nodes that does not
716  * have active links for NODE_CLEANUP_AFTER time
717  */
718 static bool tipc_node_cleanup(struct tipc_node *peer)
719 {
720 	struct tipc_node *temp_node;
721 	struct tipc_net *tn = tipc_net(peer->net);
722 	bool deleted = false;
723 
724 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
725 	if (!spin_trylock_bh(&tn->node_list_lock))
726 		return false;
727 
728 	tipc_node_write_lock(peer);
729 
730 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
731 		tipc_node_clear_links(peer);
732 		tipc_node_delete_from_list(peer);
733 		deleted = true;
734 	}
735 	tipc_node_write_unlock(peer);
736 
737 	if (!deleted) {
738 		spin_unlock_bh(&tn->node_list_lock);
739 		return deleted;
740 	}
741 
742 	/* Calculate cluster capabilities */
743 	tn->capabilities = TIPC_NODE_CAPABILITIES;
744 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
745 		tn->capabilities &= temp_node->capabilities;
746 	}
747 	tipc_bcast_toggle_rcast(peer->net,
748 				(tn->capabilities & TIPC_BCAST_RCAST));
749 	spin_unlock_bh(&tn->node_list_lock);
750 	return deleted;
751 }
752 
753 /* tipc_node_timeout - handle expiration of node timer
754  */
755 static void tipc_node_timeout(struct timer_list *t)
756 {
757 	struct tipc_node *n = from_timer(n, t, timer);
758 	struct tipc_link_entry *le;
759 	struct sk_buff_head xmitq;
760 	int remains = n->link_cnt;
761 	int bearer_id;
762 	int rc = 0;
763 
764 	trace_tipc_node_timeout(n, false, " ");
765 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
766 		/*Removing the reference of Timer*/
767 		tipc_node_put(n);
768 		return;
769 	}
770 
771 #ifdef CONFIG_TIPC_CRYPTO
772 	/* Take any crypto key related actions first */
773 	tipc_crypto_timeout(n->crypto_rx);
774 #endif
775 	__skb_queue_head_init(&xmitq);
776 
777 	/* Initial node interval to value larger (10 seconds), then it will be
778 	 * recalculated with link lowest tolerance
779 	 */
780 	tipc_node_read_lock(n);
781 	n->keepalive_intv = 10000;
782 	tipc_node_read_unlock(n);
783 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
784 		tipc_node_read_lock(n);
785 		le = &n->links[bearer_id];
786 		if (le->link) {
787 			spin_lock_bh(&le->lock);
788 			/* Link tolerance may change asynchronously: */
789 			tipc_node_calculate_timer(n, le->link);
790 			rc = tipc_link_timeout(le->link, &xmitq);
791 			spin_unlock_bh(&le->lock);
792 			remains--;
793 		}
794 		tipc_node_read_unlock(n);
795 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr, n);
796 		if (rc & TIPC_LINK_DOWN_EVT)
797 			tipc_node_link_down(n, bearer_id, false);
798 	}
799 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
800 }
801 
802 /**
803  * __tipc_node_link_up - handle addition of link
804  * Node lock must be held by caller
805  * Link becomes active (alone or shared) or standby, depending on its priority.
806  */
807 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
808 				struct sk_buff_head *xmitq)
809 {
810 	int *slot0 = &n->active_links[0];
811 	int *slot1 = &n->active_links[1];
812 	struct tipc_link *ol = node_active_link(n, 0);
813 	struct tipc_link *nl = n->links[bearer_id].link;
814 
815 	if (!nl || tipc_link_is_up(nl))
816 		return;
817 
818 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
819 	if (!tipc_link_is_up(nl))
820 		return;
821 
822 	n->working_links++;
823 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
824 	n->link_id = tipc_link_id(nl);
825 
826 	/* Leave room for tunnel header when returning 'mtu' to users: */
827 	n->links[bearer_id].mtu = tipc_link_mss(nl);
828 
829 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
830 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
831 
832 	pr_debug("Established link <%s> on network plane %c\n",
833 		 tipc_link_name(nl), tipc_link_plane(nl));
834 	trace_tipc_node_link_up(n, true, " ");
835 
836 	/* Ensure that a STATE message goes first */
837 	tipc_link_build_state_msg(nl, xmitq);
838 
839 	/* First link? => give it both slots */
840 	if (!ol) {
841 		*slot0 = bearer_id;
842 		*slot1 = bearer_id;
843 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
844 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
845 		tipc_link_set_active(nl, true);
846 		tipc_bcast_add_peer(n->net, nl, xmitq);
847 		return;
848 	}
849 
850 	/* Second link => redistribute slots */
851 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
852 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
853 		*slot0 = bearer_id;
854 		*slot1 = bearer_id;
855 		tipc_link_set_active(nl, true);
856 		tipc_link_set_active(ol, false);
857 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
858 		tipc_link_set_active(nl, true);
859 		*slot1 = bearer_id;
860 	} else {
861 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
862 	}
863 
864 	/* Prepare synchronization with first link */
865 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
866 }
867 
868 /**
869  * tipc_node_link_up - handle addition of link
870  *
871  * Link becomes active (alone or shared) or standby, depending on its priority.
872  */
873 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
874 			      struct sk_buff_head *xmitq)
875 {
876 	struct tipc_media_addr *maddr;
877 
878 	tipc_node_write_lock(n);
879 	__tipc_node_link_up(n, bearer_id, xmitq);
880 	maddr = &n->links[bearer_id].maddr;
881 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr, n);
882 	tipc_node_write_unlock(n);
883 }
884 
885 /**
886  * tipc_node_link_failover() - start failover in case "half-failover"
887  *
888  * This function is only called in a very special situation where link
889  * failover can be already started on peer node but not on this node.
890  * This can happen when e.g.
891  *	1. Both links <1A-2A>, <1B-2B> down
892  *	2. Link endpoint 2A up, but 1A still down (e.g. due to network
893  *	   disturbance, wrong session, etc.)
894  *	3. Link <1B-2B> up
895  *	4. Link endpoint 2A down (e.g. due to link tolerance timeout)
896  *	5. Node 2 starts failover onto link <1B-2B>
897  *
898  *	==> Node 1 does never start link/node failover!
899  *
900  * @n: tipc node structure
901  * @l: link peer endpoint failingover (- can be NULL)
902  * @tnl: tunnel link
903  * @xmitq: queue for messages to be xmited on tnl link later
904  */
905 static void tipc_node_link_failover(struct tipc_node *n, struct tipc_link *l,
906 				    struct tipc_link *tnl,
907 				    struct sk_buff_head *xmitq)
908 {
909 	/* Avoid to be "self-failover" that can never end */
910 	if (!tipc_link_is_up(tnl))
911 		return;
912 
913 	/* Don't rush, failure link may be in the process of resetting */
914 	if (l && !tipc_link_is_reset(l))
915 		return;
916 
917 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
918 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
919 
920 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
921 	tipc_link_failover_prepare(l, tnl, xmitq);
922 
923 	if (l)
924 		tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
925 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
926 }
927 
928 /**
929  * __tipc_node_link_down - handle loss of link
930  */
931 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
932 				  struct sk_buff_head *xmitq,
933 				  struct tipc_media_addr **maddr)
934 {
935 	struct tipc_link_entry *le = &n->links[*bearer_id];
936 	int *slot0 = &n->active_links[0];
937 	int *slot1 = &n->active_links[1];
938 	int i, highest = 0, prio;
939 	struct tipc_link *l, *_l, *tnl;
940 
941 	l = n->links[*bearer_id].link;
942 	if (!l || tipc_link_is_reset(l))
943 		return;
944 
945 	n->working_links--;
946 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
947 	n->link_id = tipc_link_id(l);
948 
949 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
950 
951 	pr_debug("Lost link <%s> on network plane %c\n",
952 		 tipc_link_name(l), tipc_link_plane(l));
953 
954 	/* Select new active link if any available */
955 	*slot0 = INVALID_BEARER_ID;
956 	*slot1 = INVALID_BEARER_ID;
957 	for (i = 0; i < MAX_BEARERS; i++) {
958 		_l = n->links[i].link;
959 		if (!_l || !tipc_link_is_up(_l))
960 			continue;
961 		if (_l == l)
962 			continue;
963 		prio = tipc_link_prio(_l);
964 		if (prio < highest)
965 			continue;
966 		if (prio > highest) {
967 			highest = prio;
968 			*slot0 = i;
969 			*slot1 = i;
970 			continue;
971 		}
972 		*slot1 = i;
973 	}
974 
975 	if (!node_is_up(n)) {
976 		if (tipc_link_peer_is_down(l))
977 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
978 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
979 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
980 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
981 		tipc_link_reset(l);
982 		tipc_link_build_reset_msg(l, xmitq);
983 		*maddr = &n->links[*bearer_id].maddr;
984 		node_lost_contact(n, &le->inputq);
985 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
986 		return;
987 	}
988 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
989 
990 	/* There is still a working link => initiate failover */
991 	*bearer_id = n->active_links[0];
992 	tnl = n->links[*bearer_id].link;
993 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
994 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
995 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
996 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
997 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
998 	tipc_link_reset(l);
999 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
1000 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1001 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
1002 	*maddr = &n->links[*bearer_id].maddr;
1003 }
1004 
1005 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
1006 {
1007 	struct tipc_link_entry *le = &n->links[bearer_id];
1008 	struct tipc_media_addr *maddr = NULL;
1009 	struct tipc_link *l = le->link;
1010 	int old_bearer_id = bearer_id;
1011 	struct sk_buff_head xmitq;
1012 
1013 	if (!l)
1014 		return;
1015 
1016 	__skb_queue_head_init(&xmitq);
1017 
1018 	tipc_node_write_lock(n);
1019 	if (!tipc_link_is_establishing(l)) {
1020 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
1021 	} else {
1022 		/* Defuse pending tipc_node_link_up() */
1023 		tipc_link_reset(l);
1024 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1025 	}
1026 	if (delete) {
1027 		kfree(l);
1028 		le->link = NULL;
1029 		n->link_cnt--;
1030 	}
1031 	trace_tipc_node_link_down(n, true, "node link down or deleted!");
1032 	tipc_node_write_unlock(n);
1033 	if (delete)
1034 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
1035 	if (!skb_queue_empty(&xmitq))
1036 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr, n);
1037 	tipc_sk_rcv(n->net, &le->inputq);
1038 }
1039 
1040 static bool node_is_up(struct tipc_node *n)
1041 {
1042 	return n->active_links[0] != INVALID_BEARER_ID;
1043 }
1044 
1045 bool tipc_node_is_up(struct net *net, u32 addr)
1046 {
1047 	struct tipc_node *n;
1048 	bool retval = false;
1049 
1050 	if (in_own_node(net, addr))
1051 		return true;
1052 
1053 	n = tipc_node_find(net, addr);
1054 	if (!n)
1055 		return false;
1056 	retval = node_is_up(n);
1057 	tipc_node_put(n);
1058 	return retval;
1059 }
1060 
1061 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
1062 {
1063 	struct tipc_node *n;
1064 
1065 	addr ^= tipc_net(net)->random;
1066 	while ((n = tipc_node_find(net, addr))) {
1067 		tipc_node_put(n);
1068 		addr++;
1069 	}
1070 	return addr;
1071 }
1072 
1073 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
1074  * Returns suggested address if any, otherwise 0
1075  */
1076 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
1077 {
1078 	struct tipc_net *tn = tipc_net(net);
1079 	struct tipc_node *n;
1080 	bool preliminary;
1081 	u32 sugg_addr;
1082 
1083 	/* Suggest new address if some other peer is using this one */
1084 	n = tipc_node_find(net, addr);
1085 	if (n) {
1086 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
1087 			addr = 0;
1088 		tipc_node_put(n);
1089 		if (!addr)
1090 			return 0;
1091 		return tipc_node_suggest_addr(net, addr);
1092 	}
1093 
1094 	/* Suggest previously used address if peer is known */
1095 	n = tipc_node_find_by_id(net, id);
1096 	if (n) {
1097 		sugg_addr = n->addr;
1098 		preliminary = n->preliminary;
1099 		tipc_node_put(n);
1100 		if (!preliminary)
1101 			return sugg_addr;
1102 	}
1103 
1104 	/* Even this node may be in conflict */
1105 	if (tn->trial_addr == addr)
1106 		return tipc_node_suggest_addr(net, addr);
1107 
1108 	return 0;
1109 }
1110 
1111 void tipc_node_check_dest(struct net *net, u32 addr,
1112 			  u8 *peer_id, struct tipc_bearer *b,
1113 			  u16 capabilities, u32 signature, u32 hash_mixes,
1114 			  struct tipc_media_addr *maddr,
1115 			  bool *respond, bool *dupl_addr)
1116 {
1117 	struct tipc_node *n;
1118 	struct tipc_link *l, *snd_l;
1119 	struct tipc_link_entry *le;
1120 	bool addr_match = false;
1121 	bool sign_match = false;
1122 	bool link_up = false;
1123 	bool accept_addr = false;
1124 	bool reset = true;
1125 	char *if_name;
1126 	unsigned long intv;
1127 	u16 session;
1128 
1129 	*dupl_addr = false;
1130 	*respond = false;
1131 
1132 	n = tipc_node_create(net, addr, peer_id, capabilities, hash_mixes,
1133 			     false);
1134 	if (!n)
1135 		return;
1136 
1137 	tipc_node_write_lock(n);
1138 	if (unlikely(!n->bc_entry.link)) {
1139 		snd_l = tipc_bc_sndlink(net);
1140 		if (!tipc_link_bc_create(net, tipc_own_addr(net),
1141 					 addr, U16_MAX,
1142 					 tipc_link_window(snd_l),
1143 					 n->capabilities,
1144 					 &n->bc_entry.inputq1,
1145 					 &n->bc_entry.namedq, snd_l,
1146 					 &n->bc_entry.link)) {
1147 			pr_warn("Broadcast rcv link creation failed, no mem\n");
1148 			tipc_node_write_unlock_fast(n);
1149 			tipc_node_put(n);
1150 			return;
1151 		}
1152 	}
1153 
1154 	le = &n->links[b->identity];
1155 
1156 	/* Prepare to validate requesting node's signature and media address */
1157 	l = le->link;
1158 	link_up = l && tipc_link_is_up(l);
1159 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1160 	sign_match = (signature == n->signature);
1161 
1162 	/* These three flags give us eight permutations: */
1163 
1164 	if (sign_match && addr_match && link_up) {
1165 		/* All is fine. Do nothing. */
1166 		reset = false;
1167 		/* Peer node is not a container/local namespace */
1168 		if (!n->peer_hash_mix)
1169 			n->peer_hash_mix = hash_mixes;
1170 	} else if (sign_match && addr_match && !link_up) {
1171 		/* Respond. The link will come up in due time */
1172 		*respond = true;
1173 	} else if (sign_match && !addr_match && link_up) {
1174 		/* Peer has changed i/f address without rebooting.
1175 		 * If so, the link will reset soon, and the next
1176 		 * discovery will be accepted. So we can ignore it.
1177 		 * It may also be an cloned or malicious peer having
1178 		 * chosen the same node address and signature as an
1179 		 * existing one.
1180 		 * Ignore requests until the link goes down, if ever.
1181 		 */
1182 		*dupl_addr = true;
1183 	} else if (sign_match && !addr_match && !link_up) {
1184 		/* Peer link has changed i/f address without rebooting.
1185 		 * It may also be a cloned or malicious peer; we can't
1186 		 * distinguish between the two.
1187 		 * The signature is correct, so we must accept.
1188 		 */
1189 		accept_addr = true;
1190 		*respond = true;
1191 	} else if (!sign_match && addr_match && link_up) {
1192 		/* Peer node rebooted. Two possibilities:
1193 		 *  - Delayed re-discovery; this link endpoint has already
1194 		 *    reset and re-established contact with the peer, before
1195 		 *    receiving a discovery message from that node.
1196 		 *    (The peer happened to receive one from this node first).
1197 		 *  - The peer came back so fast that our side has not
1198 		 *    discovered it yet. Probing from this side will soon
1199 		 *    reset the link, since there can be no working link
1200 		 *    endpoint at the peer end, and the link will re-establish.
1201 		 *  Accept the signature, since it comes from a known peer.
1202 		 */
1203 		n->signature = signature;
1204 	} else if (!sign_match && addr_match && !link_up) {
1205 		/*  The peer node has rebooted.
1206 		 *  Accept signature, since it is a known peer.
1207 		 */
1208 		n->signature = signature;
1209 		*respond = true;
1210 	} else if (!sign_match && !addr_match && link_up) {
1211 		/* Peer rebooted with new address, or a new/duplicate peer.
1212 		 * Ignore until the link goes down, if ever.
1213 		 */
1214 		*dupl_addr = true;
1215 	} else if (!sign_match && !addr_match && !link_up) {
1216 		/* Peer rebooted with new address, or it is a new peer.
1217 		 * Accept signature and address.
1218 		 */
1219 		n->signature = signature;
1220 		accept_addr = true;
1221 		*respond = true;
1222 	}
1223 
1224 	if (!accept_addr)
1225 		goto exit;
1226 
1227 	/* Now create new link if not already existing */
1228 	if (!l) {
1229 		if (n->link_cnt == 2)
1230 			goto exit;
1231 
1232 		if_name = strchr(b->name, ':') + 1;
1233 		get_random_bytes(&session, sizeof(u16));
1234 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1235 				      b->net_plane, b->mtu, b->priority,
1236 				      b->window, session,
1237 				      tipc_own_addr(net), addr, peer_id,
1238 				      n->capabilities,
1239 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1240 				      &le->inputq,
1241 				      &n->bc_entry.namedq, &l)) {
1242 			*respond = false;
1243 			goto exit;
1244 		}
1245 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1246 		tipc_link_reset(l);
1247 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1248 		if (n->state == NODE_FAILINGOVER)
1249 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1250 		le->link = l;
1251 		n->link_cnt++;
1252 		tipc_node_calculate_timer(n, l);
1253 		if (n->link_cnt == 1) {
1254 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1255 			if (!mod_timer(&n->timer, intv))
1256 				tipc_node_get(n);
1257 		}
1258 	}
1259 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1260 exit:
1261 	tipc_node_write_unlock(n);
1262 	if (reset && l && !tipc_link_is_reset(l))
1263 		tipc_node_link_down(n, b->identity, false);
1264 	tipc_node_put(n);
1265 }
1266 
1267 void tipc_node_delete_links(struct net *net, int bearer_id)
1268 {
1269 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1270 	struct tipc_node *n;
1271 
1272 	rcu_read_lock();
1273 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1274 		tipc_node_link_down(n, bearer_id, true);
1275 	}
1276 	rcu_read_unlock();
1277 }
1278 
1279 static void tipc_node_reset_links(struct tipc_node *n)
1280 {
1281 	int i;
1282 
1283 	pr_warn("Resetting all links to %x\n", n->addr);
1284 
1285 	trace_tipc_node_reset_links(n, true, " ");
1286 	for (i = 0; i < MAX_BEARERS; i++) {
1287 		tipc_node_link_down(n, i, false);
1288 	}
1289 }
1290 
1291 /* tipc_node_fsm_evt - node finite state machine
1292  * Determines when contact is allowed with peer node
1293  */
1294 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1295 {
1296 	int state = n->state;
1297 
1298 	switch (state) {
1299 	case SELF_DOWN_PEER_DOWN:
1300 		switch (evt) {
1301 		case SELF_ESTABL_CONTACT_EVT:
1302 			state = SELF_UP_PEER_COMING;
1303 			break;
1304 		case PEER_ESTABL_CONTACT_EVT:
1305 			state = SELF_COMING_PEER_UP;
1306 			break;
1307 		case SELF_LOST_CONTACT_EVT:
1308 		case PEER_LOST_CONTACT_EVT:
1309 			break;
1310 		case NODE_SYNCH_END_EVT:
1311 		case NODE_SYNCH_BEGIN_EVT:
1312 		case NODE_FAILOVER_BEGIN_EVT:
1313 		case NODE_FAILOVER_END_EVT:
1314 		default:
1315 			goto illegal_evt;
1316 		}
1317 		break;
1318 	case SELF_UP_PEER_UP:
1319 		switch (evt) {
1320 		case SELF_LOST_CONTACT_EVT:
1321 			state = SELF_DOWN_PEER_LEAVING;
1322 			break;
1323 		case PEER_LOST_CONTACT_EVT:
1324 			state = SELF_LEAVING_PEER_DOWN;
1325 			break;
1326 		case NODE_SYNCH_BEGIN_EVT:
1327 			state = NODE_SYNCHING;
1328 			break;
1329 		case NODE_FAILOVER_BEGIN_EVT:
1330 			state = NODE_FAILINGOVER;
1331 			break;
1332 		case SELF_ESTABL_CONTACT_EVT:
1333 		case PEER_ESTABL_CONTACT_EVT:
1334 		case NODE_SYNCH_END_EVT:
1335 		case NODE_FAILOVER_END_EVT:
1336 			break;
1337 		default:
1338 			goto illegal_evt;
1339 		}
1340 		break;
1341 	case SELF_DOWN_PEER_LEAVING:
1342 		switch (evt) {
1343 		case PEER_LOST_CONTACT_EVT:
1344 			state = SELF_DOWN_PEER_DOWN;
1345 			break;
1346 		case SELF_ESTABL_CONTACT_EVT:
1347 		case PEER_ESTABL_CONTACT_EVT:
1348 		case SELF_LOST_CONTACT_EVT:
1349 			break;
1350 		case NODE_SYNCH_END_EVT:
1351 		case NODE_SYNCH_BEGIN_EVT:
1352 		case NODE_FAILOVER_BEGIN_EVT:
1353 		case NODE_FAILOVER_END_EVT:
1354 		default:
1355 			goto illegal_evt;
1356 		}
1357 		break;
1358 	case SELF_UP_PEER_COMING:
1359 		switch (evt) {
1360 		case PEER_ESTABL_CONTACT_EVT:
1361 			state = SELF_UP_PEER_UP;
1362 			break;
1363 		case SELF_LOST_CONTACT_EVT:
1364 			state = SELF_DOWN_PEER_DOWN;
1365 			break;
1366 		case SELF_ESTABL_CONTACT_EVT:
1367 		case PEER_LOST_CONTACT_EVT:
1368 		case NODE_SYNCH_END_EVT:
1369 		case NODE_FAILOVER_BEGIN_EVT:
1370 			break;
1371 		case NODE_SYNCH_BEGIN_EVT:
1372 		case NODE_FAILOVER_END_EVT:
1373 		default:
1374 			goto illegal_evt;
1375 		}
1376 		break;
1377 	case SELF_COMING_PEER_UP:
1378 		switch (evt) {
1379 		case SELF_ESTABL_CONTACT_EVT:
1380 			state = SELF_UP_PEER_UP;
1381 			break;
1382 		case PEER_LOST_CONTACT_EVT:
1383 			state = SELF_DOWN_PEER_DOWN;
1384 			break;
1385 		case SELF_LOST_CONTACT_EVT:
1386 		case PEER_ESTABL_CONTACT_EVT:
1387 			break;
1388 		case NODE_SYNCH_END_EVT:
1389 		case NODE_SYNCH_BEGIN_EVT:
1390 		case NODE_FAILOVER_BEGIN_EVT:
1391 		case NODE_FAILOVER_END_EVT:
1392 		default:
1393 			goto illegal_evt;
1394 		}
1395 		break;
1396 	case SELF_LEAVING_PEER_DOWN:
1397 		switch (evt) {
1398 		case SELF_LOST_CONTACT_EVT:
1399 			state = SELF_DOWN_PEER_DOWN;
1400 			break;
1401 		case SELF_ESTABL_CONTACT_EVT:
1402 		case PEER_ESTABL_CONTACT_EVT:
1403 		case PEER_LOST_CONTACT_EVT:
1404 			break;
1405 		case NODE_SYNCH_END_EVT:
1406 		case NODE_SYNCH_BEGIN_EVT:
1407 		case NODE_FAILOVER_BEGIN_EVT:
1408 		case NODE_FAILOVER_END_EVT:
1409 		default:
1410 			goto illegal_evt;
1411 		}
1412 		break;
1413 	case NODE_FAILINGOVER:
1414 		switch (evt) {
1415 		case SELF_LOST_CONTACT_EVT:
1416 			state = SELF_DOWN_PEER_LEAVING;
1417 			break;
1418 		case PEER_LOST_CONTACT_EVT:
1419 			state = SELF_LEAVING_PEER_DOWN;
1420 			break;
1421 		case NODE_FAILOVER_END_EVT:
1422 			state = SELF_UP_PEER_UP;
1423 			break;
1424 		case NODE_FAILOVER_BEGIN_EVT:
1425 		case SELF_ESTABL_CONTACT_EVT:
1426 		case PEER_ESTABL_CONTACT_EVT:
1427 			break;
1428 		case NODE_SYNCH_BEGIN_EVT:
1429 		case NODE_SYNCH_END_EVT:
1430 		default:
1431 			goto illegal_evt;
1432 		}
1433 		break;
1434 	case NODE_SYNCHING:
1435 		switch (evt) {
1436 		case SELF_LOST_CONTACT_EVT:
1437 			state = SELF_DOWN_PEER_LEAVING;
1438 			break;
1439 		case PEER_LOST_CONTACT_EVT:
1440 			state = SELF_LEAVING_PEER_DOWN;
1441 			break;
1442 		case NODE_SYNCH_END_EVT:
1443 			state = SELF_UP_PEER_UP;
1444 			break;
1445 		case NODE_FAILOVER_BEGIN_EVT:
1446 			state = NODE_FAILINGOVER;
1447 			break;
1448 		case NODE_SYNCH_BEGIN_EVT:
1449 		case SELF_ESTABL_CONTACT_EVT:
1450 		case PEER_ESTABL_CONTACT_EVT:
1451 			break;
1452 		case NODE_FAILOVER_END_EVT:
1453 		default:
1454 			goto illegal_evt;
1455 		}
1456 		break;
1457 	default:
1458 		pr_err("Unknown node fsm state %x\n", state);
1459 		break;
1460 	}
1461 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1462 	n->state = state;
1463 	return;
1464 
1465 illegal_evt:
1466 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1467 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1468 }
1469 
1470 static void node_lost_contact(struct tipc_node *n,
1471 			      struct sk_buff_head *inputq)
1472 {
1473 	struct tipc_sock_conn *conn, *safe;
1474 	struct tipc_link *l;
1475 	struct list_head *conns = &n->conn_sks;
1476 	struct sk_buff *skb;
1477 	uint i;
1478 
1479 	pr_debug("Lost contact with %x\n", n->addr);
1480 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1481 	trace_tipc_node_lost_contact(n, true, " ");
1482 
1483 	/* Clean up broadcast state */
1484 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1485 
1486 	/* Abort any ongoing link failover */
1487 	for (i = 0; i < MAX_BEARERS; i++) {
1488 		l = n->links[i].link;
1489 		if (l)
1490 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1491 	}
1492 
1493 	/* Notify publications from this node */
1494 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1495 	n->peer_net = NULL;
1496 	n->peer_hash_mix = 0;
1497 	/* Notify sockets connected to node */
1498 	list_for_each_entry_safe(conn, safe, conns, list) {
1499 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1500 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1501 				      conn->peer_node, conn->port,
1502 				      conn->peer_port, TIPC_ERR_NO_NODE);
1503 		if (likely(skb))
1504 			skb_queue_tail(inputq, skb);
1505 		list_del(&conn->list);
1506 		kfree(conn);
1507 	}
1508 }
1509 
1510 /**
1511  * tipc_node_get_linkname - get the name of a link
1512  *
1513  * @bearer_id: id of the bearer
1514  * @node: peer node address
1515  * @linkname: link name output buffer
1516  *
1517  * Returns 0 on success
1518  */
1519 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1520 			   char *linkname, size_t len)
1521 {
1522 	struct tipc_link *link;
1523 	int err = -EINVAL;
1524 	struct tipc_node *node = tipc_node_find(net, addr);
1525 
1526 	if (!node)
1527 		return err;
1528 
1529 	if (bearer_id >= MAX_BEARERS)
1530 		goto exit;
1531 
1532 	tipc_node_read_lock(node);
1533 	link = node->links[bearer_id].link;
1534 	if (link) {
1535 		strncpy(linkname, tipc_link_name(link), len);
1536 		err = 0;
1537 	}
1538 	tipc_node_read_unlock(node);
1539 exit:
1540 	tipc_node_put(node);
1541 	return err;
1542 }
1543 
1544 /* Caller should hold node lock for the passed node */
1545 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1546 {
1547 	void *hdr;
1548 	struct nlattr *attrs;
1549 
1550 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1551 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1552 	if (!hdr)
1553 		return -EMSGSIZE;
1554 
1555 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1556 	if (!attrs)
1557 		goto msg_full;
1558 
1559 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1560 		goto attr_msg_full;
1561 	if (node_is_up(node))
1562 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1563 			goto attr_msg_full;
1564 
1565 	nla_nest_end(msg->skb, attrs);
1566 	genlmsg_end(msg->skb, hdr);
1567 
1568 	return 0;
1569 
1570 attr_msg_full:
1571 	nla_nest_cancel(msg->skb, attrs);
1572 msg_full:
1573 	genlmsg_cancel(msg->skb, hdr);
1574 
1575 	return -EMSGSIZE;
1576 }
1577 
1578 static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)
1579 {
1580 	struct tipc_msg *hdr = buf_msg(skb_peek(list));
1581 	struct sk_buff_head inputq;
1582 
1583 	switch (msg_user(hdr)) {
1584 	case TIPC_LOW_IMPORTANCE:
1585 	case TIPC_MEDIUM_IMPORTANCE:
1586 	case TIPC_HIGH_IMPORTANCE:
1587 	case TIPC_CRITICAL_IMPORTANCE:
1588 		if (msg_connected(hdr) || msg_named(hdr)) {
1589 			tipc_loopback_trace(peer_net, list);
1590 			spin_lock_init(&list->lock);
1591 			tipc_sk_rcv(peer_net, list);
1592 			return;
1593 		}
1594 		if (msg_mcast(hdr)) {
1595 			tipc_loopback_trace(peer_net, list);
1596 			skb_queue_head_init(&inputq);
1597 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1598 			__skb_queue_purge(list);
1599 			skb_queue_purge(&inputq);
1600 			return;
1601 		}
1602 		return;
1603 	case MSG_FRAGMENTER:
1604 		if (tipc_msg_assemble(list)) {
1605 			tipc_loopback_trace(peer_net, list);
1606 			skb_queue_head_init(&inputq);
1607 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1608 			__skb_queue_purge(list);
1609 			skb_queue_purge(&inputq);
1610 		}
1611 		return;
1612 	case GROUP_PROTOCOL:
1613 	case CONN_MANAGER:
1614 		tipc_loopback_trace(peer_net, list);
1615 		spin_lock_init(&list->lock);
1616 		tipc_sk_rcv(peer_net, list);
1617 		return;
1618 	case LINK_PROTOCOL:
1619 	case NAME_DISTRIBUTOR:
1620 	case TUNNEL_PROTOCOL:
1621 	case BCAST_PROTOCOL:
1622 		return;
1623 	default:
1624 		return;
1625 	};
1626 }
1627 
1628 /**
1629  * tipc_node_xmit() is the general link level function for message sending
1630  * @net: the applicable net namespace
1631  * @list: chain of buffers containing message
1632  * @dnode: address of destination node
1633  * @selector: a number used for deterministic link selection
1634  * Consumes the buffer chain.
1635  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1636  */
1637 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1638 		   u32 dnode, int selector)
1639 {
1640 	struct tipc_link_entry *le = NULL;
1641 	struct tipc_node *n;
1642 	struct sk_buff_head xmitq;
1643 	bool node_up = false;
1644 	int bearer_id;
1645 	int rc;
1646 
1647 	if (in_own_node(net, dnode)) {
1648 		tipc_loopback_trace(net, list);
1649 		spin_lock_init(&list->lock);
1650 		tipc_sk_rcv(net, list);
1651 		return 0;
1652 	}
1653 
1654 	n = tipc_node_find(net, dnode);
1655 	if (unlikely(!n)) {
1656 		__skb_queue_purge(list);
1657 		return -EHOSTUNREACH;
1658 	}
1659 
1660 	tipc_node_read_lock(n);
1661 	node_up = node_is_up(n);
1662 	if (node_up && n->peer_net && check_net(n->peer_net)) {
1663 		/* xmit inner linux container */
1664 		tipc_lxc_xmit(n->peer_net, list);
1665 		if (likely(skb_queue_empty(list))) {
1666 			tipc_node_read_unlock(n);
1667 			tipc_node_put(n);
1668 			return 0;
1669 		}
1670 	}
1671 
1672 	bearer_id = n->active_links[selector & 1];
1673 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1674 		tipc_node_read_unlock(n);
1675 		tipc_node_put(n);
1676 		__skb_queue_purge(list);
1677 		return -EHOSTUNREACH;
1678 	}
1679 
1680 	__skb_queue_head_init(&xmitq);
1681 	le = &n->links[bearer_id];
1682 	spin_lock_bh(&le->lock);
1683 	rc = tipc_link_xmit(le->link, list, &xmitq);
1684 	spin_unlock_bh(&le->lock);
1685 	tipc_node_read_unlock(n);
1686 
1687 	if (unlikely(rc == -ENOBUFS))
1688 		tipc_node_link_down(n, bearer_id, false);
1689 	else
1690 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1691 
1692 	tipc_node_put(n);
1693 
1694 	return rc;
1695 }
1696 
1697 /* tipc_node_xmit_skb(): send single buffer to destination
1698  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1699  * messages, which will not be rejected
1700  * The only exception is datagram messages rerouted after secondary
1701  * lookup, which are rare and safe to dispose of anyway.
1702  */
1703 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1704 		       u32 selector)
1705 {
1706 	struct sk_buff_head head;
1707 
1708 	__skb_queue_head_init(&head);
1709 	__skb_queue_tail(&head, skb);
1710 	tipc_node_xmit(net, &head, dnode, selector);
1711 	return 0;
1712 }
1713 
1714 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1715  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1716  */
1717 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1718 {
1719 	struct sk_buff *skb;
1720 	u32 selector, dnode;
1721 
1722 	while ((skb = __skb_dequeue(xmitq))) {
1723 		selector = msg_origport(buf_msg(skb));
1724 		dnode = msg_destnode(buf_msg(skb));
1725 		tipc_node_xmit_skb(net, skb, dnode, selector);
1726 	}
1727 	return 0;
1728 }
1729 
1730 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1731 {
1732 	struct sk_buff *txskb;
1733 	struct tipc_node *n;
1734 	u32 dst;
1735 
1736 	rcu_read_lock();
1737 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1738 		dst = n->addr;
1739 		if (in_own_node(net, dst))
1740 			continue;
1741 		if (!node_is_up(n))
1742 			continue;
1743 		txskb = pskb_copy(skb, GFP_ATOMIC);
1744 		if (!txskb)
1745 			break;
1746 		msg_set_destnode(buf_msg(txskb), dst);
1747 		tipc_node_xmit_skb(net, txskb, dst, 0);
1748 	}
1749 	rcu_read_unlock();
1750 
1751 	kfree_skb(skb);
1752 }
1753 
1754 static void tipc_node_mcast_rcv(struct tipc_node *n)
1755 {
1756 	struct tipc_bclink_entry *be = &n->bc_entry;
1757 
1758 	/* 'arrvq' is under inputq2's lock protection */
1759 	spin_lock_bh(&be->inputq2.lock);
1760 	spin_lock_bh(&be->inputq1.lock);
1761 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1762 	spin_unlock_bh(&be->inputq1.lock);
1763 	spin_unlock_bh(&be->inputq2.lock);
1764 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1765 }
1766 
1767 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1768 				  int bearer_id, struct sk_buff_head *xmitq)
1769 {
1770 	struct tipc_link *ucl;
1771 	int rc;
1772 
1773 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1774 
1775 	if (rc & TIPC_LINK_DOWN_EVT) {
1776 		tipc_node_reset_links(n);
1777 		return;
1778 	}
1779 
1780 	if (!(rc & TIPC_LINK_SND_STATE))
1781 		return;
1782 
1783 	/* If probe message, a STATE response will be sent anyway */
1784 	if (msg_probe(hdr))
1785 		return;
1786 
1787 	/* Produce a STATE message carrying broadcast NACK */
1788 	tipc_node_read_lock(n);
1789 	ucl = n->links[bearer_id].link;
1790 	if (ucl)
1791 		tipc_link_build_state_msg(ucl, xmitq);
1792 	tipc_node_read_unlock(n);
1793 }
1794 
1795 /**
1796  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1797  * @net: the applicable net namespace
1798  * @skb: TIPC packet
1799  * @bearer_id: id of bearer message arrived on
1800  *
1801  * Invoked with no locks held.
1802  */
1803 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1804 {
1805 	int rc;
1806 	struct sk_buff_head xmitq;
1807 	struct tipc_bclink_entry *be;
1808 	struct tipc_link_entry *le;
1809 	struct tipc_msg *hdr = buf_msg(skb);
1810 	int usr = msg_user(hdr);
1811 	u32 dnode = msg_destnode(hdr);
1812 	struct tipc_node *n;
1813 
1814 	__skb_queue_head_init(&xmitq);
1815 
1816 	/* If NACK for other node, let rcv link for that node peek into it */
1817 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1818 		n = tipc_node_find(net, dnode);
1819 	else
1820 		n = tipc_node_find(net, msg_prevnode(hdr));
1821 	if (!n) {
1822 		kfree_skb(skb);
1823 		return;
1824 	}
1825 	be = &n->bc_entry;
1826 	le = &n->links[bearer_id];
1827 
1828 	rc = tipc_bcast_rcv(net, be->link, skb);
1829 
1830 	/* Broadcast ACKs are sent on a unicast link */
1831 	if (rc & TIPC_LINK_SND_STATE) {
1832 		tipc_node_read_lock(n);
1833 		tipc_link_build_state_msg(le->link, &xmitq);
1834 		tipc_node_read_unlock(n);
1835 	}
1836 
1837 	if (!skb_queue_empty(&xmitq))
1838 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1839 
1840 	if (!skb_queue_empty(&be->inputq1))
1841 		tipc_node_mcast_rcv(n);
1842 
1843 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1844 	if (!skb_queue_empty(&n->bc_entry.namedq))
1845 		tipc_named_rcv(net, &n->bc_entry.namedq);
1846 
1847 	/* If reassembly or retransmission failure => reset all links to peer */
1848 	if (rc & TIPC_LINK_DOWN_EVT)
1849 		tipc_node_reset_links(n);
1850 
1851 	tipc_node_put(n);
1852 }
1853 
1854 /**
1855  * tipc_node_check_state - check and if necessary update node state
1856  * @skb: TIPC packet
1857  * @bearer_id: identity of bearer delivering the packet
1858  * Returns true if state and msg are ok, otherwise false
1859  */
1860 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1861 				  int bearer_id, struct sk_buff_head *xmitq)
1862 {
1863 	struct tipc_msg *hdr = buf_msg(skb);
1864 	int usr = msg_user(hdr);
1865 	int mtyp = msg_type(hdr);
1866 	u16 oseqno = msg_seqno(hdr);
1867 	u16 exp_pkts = msg_msgcnt(hdr);
1868 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1869 	int state = n->state;
1870 	struct tipc_link *l, *tnl, *pl = NULL;
1871 	struct tipc_media_addr *maddr;
1872 	int pb_id;
1873 
1874 	if (trace_tipc_node_check_state_enabled()) {
1875 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1876 		trace_tipc_node_check_state(n, true, " ");
1877 	}
1878 	l = n->links[bearer_id].link;
1879 	if (!l)
1880 		return false;
1881 	rcv_nxt = tipc_link_rcv_nxt(l);
1882 
1883 
1884 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1885 		return true;
1886 
1887 	/* Find parallel link, if any */
1888 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1889 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1890 			pl = n->links[pb_id].link;
1891 			break;
1892 		}
1893 	}
1894 
1895 	if (!tipc_link_validate_msg(l, hdr)) {
1896 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1897 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1898 		return false;
1899 	}
1900 
1901 	/* Check and update node accesibility if applicable */
1902 	if (state == SELF_UP_PEER_COMING) {
1903 		if (!tipc_link_is_up(l))
1904 			return true;
1905 		if (!msg_peer_link_is_up(hdr))
1906 			return true;
1907 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1908 	}
1909 
1910 	if (state == SELF_DOWN_PEER_LEAVING) {
1911 		if (msg_peer_node_is_up(hdr))
1912 			return false;
1913 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1914 		return true;
1915 	}
1916 
1917 	if (state == SELF_LEAVING_PEER_DOWN)
1918 		return false;
1919 
1920 	/* Ignore duplicate packets */
1921 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1922 		return true;
1923 
1924 	/* Initiate or update failover mode if applicable */
1925 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1926 		syncpt = oseqno + exp_pkts - 1;
1927 		if (pl && !tipc_link_is_reset(pl)) {
1928 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1929 			trace_tipc_node_link_down(n, true,
1930 						  "node link down <- failover!");
1931 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1932 							tipc_link_inputq(l));
1933 		}
1934 
1935 		/* If parallel link was already down, and this happened before
1936 		 * the tunnel link came up, node failover was never started.
1937 		 * Ensure that a FAILOVER_MSG is sent to get peer out of
1938 		 * NODE_FAILINGOVER state, also this node must accept
1939 		 * TUNNEL_MSGs from peer.
1940 		 */
1941 		if (n->state != NODE_FAILINGOVER)
1942 			tipc_node_link_failover(n, pl, l, xmitq);
1943 
1944 		/* If pkts arrive out of order, use lowest calculated syncpt */
1945 		if (less(syncpt, n->sync_point))
1946 			n->sync_point = syncpt;
1947 	}
1948 
1949 	/* Open parallel link when tunnel link reaches synch point */
1950 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1951 		if (!more(rcv_nxt, n->sync_point))
1952 			return true;
1953 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1954 		if (pl)
1955 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1956 		return true;
1957 	}
1958 
1959 	/* No synching needed if only one link */
1960 	if (!pl || !tipc_link_is_up(pl))
1961 		return true;
1962 
1963 	/* Initiate synch mode if applicable */
1964 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1965 		if (n->capabilities & TIPC_TUNNEL_ENHANCED)
1966 			syncpt = msg_syncpt(hdr);
1967 		else
1968 			syncpt = msg_seqno(msg_inner_hdr(hdr)) + exp_pkts - 1;
1969 		if (!tipc_link_is_up(l))
1970 			__tipc_node_link_up(n, bearer_id, xmitq);
1971 		if (n->state == SELF_UP_PEER_UP) {
1972 			n->sync_point = syncpt;
1973 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1974 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1975 		}
1976 	}
1977 
1978 	/* Open tunnel link when parallel link reaches synch point */
1979 	if (n->state == NODE_SYNCHING) {
1980 		if (tipc_link_is_synching(l)) {
1981 			tnl = l;
1982 		} else {
1983 			tnl = pl;
1984 			pl = l;
1985 		}
1986 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
1987 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1988 		if (more(dlv_nxt, n->sync_point)) {
1989 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1990 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1991 			return true;
1992 		}
1993 		if (l == pl)
1994 			return true;
1995 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1996 			return true;
1997 		if (usr == LINK_PROTOCOL)
1998 			return true;
1999 		return false;
2000 	}
2001 	return true;
2002 }
2003 
2004 /**
2005  * tipc_rcv - process TIPC packets/messages arriving from off-node
2006  * @net: the applicable net namespace
2007  * @skb: TIPC packet
2008  * @bearer: pointer to bearer message arrived on
2009  *
2010  * Invoked with no locks held. Bearer pointer must point to a valid bearer
2011  * structure (i.e. cannot be NULL), but bearer can be inactive.
2012  */
2013 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
2014 {
2015 	struct sk_buff_head xmitq;
2016 	struct tipc_link_entry *le;
2017 	struct tipc_msg *hdr;
2018 	struct tipc_node *n;
2019 	int bearer_id = b->identity;
2020 	u32 self = tipc_own_addr(net);
2021 	int usr, rc = 0;
2022 	u16 bc_ack;
2023 #ifdef CONFIG_TIPC_CRYPTO
2024 	struct tipc_ehdr *ehdr;
2025 
2026 	/* Check if message must be decrypted first */
2027 	if (TIPC_SKB_CB(skb)->decrypted || !tipc_ehdr_validate(skb))
2028 		goto rcv;
2029 
2030 	ehdr = (struct tipc_ehdr *)skb->data;
2031 	if (likely(ehdr->user != LINK_CONFIG)) {
2032 		n = tipc_node_find(net, ntohl(ehdr->addr));
2033 		if (unlikely(!n))
2034 			goto discard;
2035 	} else {
2036 		n = tipc_node_find_by_id(net, ehdr->id);
2037 	}
2038 	tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
2039 	if (!skb)
2040 		return;
2041 
2042 rcv:
2043 #endif
2044 	/* Ensure message is well-formed before touching the header */
2045 	if (unlikely(!tipc_msg_validate(&skb)))
2046 		goto discard;
2047 	__skb_queue_head_init(&xmitq);
2048 	hdr = buf_msg(skb);
2049 	usr = msg_user(hdr);
2050 	bc_ack = msg_bcast_ack(hdr);
2051 
2052 	/* Handle arrival of discovery or broadcast packet */
2053 	if (unlikely(msg_non_seq(hdr))) {
2054 		if (unlikely(usr == LINK_CONFIG))
2055 			return tipc_disc_rcv(net, skb, b);
2056 		else
2057 			return tipc_node_bc_rcv(net, skb, bearer_id);
2058 	}
2059 
2060 	/* Discard unicast link messages destined for another node */
2061 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
2062 		goto discard;
2063 
2064 	/* Locate neighboring node that sent packet */
2065 	n = tipc_node_find(net, msg_prevnode(hdr));
2066 	if (unlikely(!n))
2067 		goto discard;
2068 	le = &n->links[bearer_id];
2069 
2070 	/* Ensure broadcast reception is in synch with peer's send state */
2071 	if (unlikely(usr == LINK_PROTOCOL))
2072 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
2073 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
2074 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
2075 
2076 	/* Receive packet directly if conditions permit */
2077 	tipc_node_read_lock(n);
2078 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
2079 		spin_lock_bh(&le->lock);
2080 		if (le->link) {
2081 			rc = tipc_link_rcv(le->link, skb, &xmitq);
2082 			skb = NULL;
2083 		}
2084 		spin_unlock_bh(&le->lock);
2085 	}
2086 	tipc_node_read_unlock(n);
2087 
2088 	/* Check/update node state before receiving */
2089 	if (unlikely(skb)) {
2090 		if (unlikely(skb_linearize(skb)))
2091 			goto discard;
2092 		tipc_node_write_lock(n);
2093 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
2094 			if (le->link) {
2095 				rc = tipc_link_rcv(le->link, skb, &xmitq);
2096 				skb = NULL;
2097 			}
2098 		}
2099 		tipc_node_write_unlock(n);
2100 	}
2101 
2102 	if (unlikely(rc & TIPC_LINK_UP_EVT))
2103 		tipc_node_link_up(n, bearer_id, &xmitq);
2104 
2105 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
2106 		tipc_node_link_down(n, bearer_id, false);
2107 
2108 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
2109 		tipc_named_rcv(net, &n->bc_entry.namedq);
2110 
2111 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
2112 		tipc_node_mcast_rcv(n);
2113 
2114 	if (!skb_queue_empty(&le->inputq))
2115 		tipc_sk_rcv(net, &le->inputq);
2116 
2117 	if (!skb_queue_empty(&xmitq))
2118 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
2119 
2120 	tipc_node_put(n);
2121 discard:
2122 	kfree_skb(skb);
2123 }
2124 
2125 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
2126 			      int prop)
2127 {
2128 	struct tipc_net *tn = tipc_net(net);
2129 	int bearer_id = b->identity;
2130 	struct sk_buff_head xmitq;
2131 	struct tipc_link_entry *e;
2132 	struct tipc_node *n;
2133 
2134 	__skb_queue_head_init(&xmitq);
2135 
2136 	rcu_read_lock();
2137 
2138 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2139 		tipc_node_write_lock(n);
2140 		e = &n->links[bearer_id];
2141 		if (e->link) {
2142 			if (prop == TIPC_NLA_PROP_TOL)
2143 				tipc_link_set_tolerance(e->link, b->tolerance,
2144 							&xmitq);
2145 			else if (prop == TIPC_NLA_PROP_MTU)
2146 				tipc_link_set_mtu(e->link, b->mtu);
2147 		}
2148 		tipc_node_write_unlock(n);
2149 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
2150 	}
2151 
2152 	rcu_read_unlock();
2153 }
2154 
2155 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
2156 {
2157 	struct net *net = sock_net(skb->sk);
2158 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2159 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
2160 	struct tipc_node *peer, *temp_node;
2161 	u32 addr;
2162 	int err;
2163 
2164 	/* We identify the peer by its net */
2165 	if (!info->attrs[TIPC_NLA_NET])
2166 		return -EINVAL;
2167 
2168 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
2169 					  info->attrs[TIPC_NLA_NET],
2170 					  tipc_nl_net_policy, info->extack);
2171 	if (err)
2172 		return err;
2173 
2174 	if (!attrs[TIPC_NLA_NET_ADDR])
2175 		return -EINVAL;
2176 
2177 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
2178 
2179 	if (in_own_node(net, addr))
2180 		return -ENOTSUPP;
2181 
2182 	spin_lock_bh(&tn->node_list_lock);
2183 	peer = tipc_node_find(net, addr);
2184 	if (!peer) {
2185 		spin_unlock_bh(&tn->node_list_lock);
2186 		return -ENXIO;
2187 	}
2188 
2189 	tipc_node_write_lock(peer);
2190 	if (peer->state != SELF_DOWN_PEER_DOWN &&
2191 	    peer->state != SELF_DOWN_PEER_LEAVING) {
2192 		tipc_node_write_unlock(peer);
2193 		err = -EBUSY;
2194 		goto err_out;
2195 	}
2196 
2197 	tipc_node_clear_links(peer);
2198 	tipc_node_write_unlock(peer);
2199 	tipc_node_delete(peer);
2200 
2201 	/* Calculate cluster capabilities */
2202 	tn->capabilities = TIPC_NODE_CAPABILITIES;
2203 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
2204 		tn->capabilities &= temp_node->capabilities;
2205 	}
2206 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
2207 	err = 0;
2208 err_out:
2209 	tipc_node_put(peer);
2210 	spin_unlock_bh(&tn->node_list_lock);
2211 
2212 	return err;
2213 }
2214 
2215 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
2216 {
2217 	int err;
2218 	struct net *net = sock_net(skb->sk);
2219 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2220 	int done = cb->args[0];
2221 	int last_addr = cb->args[1];
2222 	struct tipc_node *node;
2223 	struct tipc_nl_msg msg;
2224 
2225 	if (done)
2226 		return 0;
2227 
2228 	msg.skb = skb;
2229 	msg.portid = NETLINK_CB(cb->skb).portid;
2230 	msg.seq = cb->nlh->nlmsg_seq;
2231 
2232 	rcu_read_lock();
2233 	if (last_addr) {
2234 		node = tipc_node_find(net, last_addr);
2235 		if (!node) {
2236 			rcu_read_unlock();
2237 			/* We never set seq or call nl_dump_check_consistent()
2238 			 * this means that setting prev_seq here will cause the
2239 			 * consistence check to fail in the netlink callback
2240 			 * handler. Resulting in the NLMSG_DONE message having
2241 			 * the NLM_F_DUMP_INTR flag set if the node state
2242 			 * changed while we released the lock.
2243 			 */
2244 			cb->prev_seq = 1;
2245 			return -EPIPE;
2246 		}
2247 		tipc_node_put(node);
2248 	}
2249 
2250 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2251 		if (node->preliminary)
2252 			continue;
2253 		if (last_addr) {
2254 			if (node->addr == last_addr)
2255 				last_addr = 0;
2256 			else
2257 				continue;
2258 		}
2259 
2260 		tipc_node_read_lock(node);
2261 		err = __tipc_nl_add_node(&msg, node);
2262 		if (err) {
2263 			last_addr = node->addr;
2264 			tipc_node_read_unlock(node);
2265 			goto out;
2266 		}
2267 
2268 		tipc_node_read_unlock(node);
2269 	}
2270 	done = 1;
2271 out:
2272 	cb->args[0] = done;
2273 	cb->args[1] = last_addr;
2274 	rcu_read_unlock();
2275 
2276 	return skb->len;
2277 }
2278 
2279 /* tipc_node_find_by_name - locate owner node of link by link's name
2280  * @net: the applicable net namespace
2281  * @name: pointer to link name string
2282  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2283  *
2284  * Returns pointer to node owning the link, or 0 if no matching link is found.
2285  */
2286 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2287 						const char *link_name,
2288 						unsigned int *bearer_id)
2289 {
2290 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2291 	struct tipc_link *l;
2292 	struct tipc_node *n;
2293 	struct tipc_node *found_node = NULL;
2294 	int i;
2295 
2296 	*bearer_id = 0;
2297 	rcu_read_lock();
2298 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2299 		tipc_node_read_lock(n);
2300 		for (i = 0; i < MAX_BEARERS; i++) {
2301 			l = n->links[i].link;
2302 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2303 				*bearer_id = i;
2304 				found_node = n;
2305 				break;
2306 			}
2307 		}
2308 		tipc_node_read_unlock(n);
2309 		if (found_node)
2310 			break;
2311 	}
2312 	rcu_read_unlock();
2313 
2314 	return found_node;
2315 }
2316 
2317 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2318 {
2319 	int err;
2320 	int res = 0;
2321 	int bearer_id;
2322 	char *name;
2323 	struct tipc_link *link;
2324 	struct tipc_node *node;
2325 	struct sk_buff_head xmitq;
2326 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2327 	struct net *net = sock_net(skb->sk);
2328 
2329 	__skb_queue_head_init(&xmitq);
2330 
2331 	if (!info->attrs[TIPC_NLA_LINK])
2332 		return -EINVAL;
2333 
2334 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2335 					  info->attrs[TIPC_NLA_LINK],
2336 					  tipc_nl_link_policy, info->extack);
2337 	if (err)
2338 		return err;
2339 
2340 	if (!attrs[TIPC_NLA_LINK_NAME])
2341 		return -EINVAL;
2342 
2343 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2344 
2345 	if (strcmp(name, tipc_bclink_name) == 0)
2346 		return tipc_nl_bc_link_set(net, attrs);
2347 
2348 	node = tipc_node_find_by_name(net, name, &bearer_id);
2349 	if (!node)
2350 		return -EINVAL;
2351 
2352 	tipc_node_read_lock(node);
2353 
2354 	link = node->links[bearer_id].link;
2355 	if (!link) {
2356 		res = -EINVAL;
2357 		goto out;
2358 	}
2359 
2360 	if (attrs[TIPC_NLA_LINK_PROP]) {
2361 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2362 
2363 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2364 					      props);
2365 		if (err) {
2366 			res = err;
2367 			goto out;
2368 		}
2369 
2370 		if (props[TIPC_NLA_PROP_TOL]) {
2371 			u32 tol;
2372 
2373 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2374 			tipc_link_set_tolerance(link, tol, &xmitq);
2375 		}
2376 		if (props[TIPC_NLA_PROP_PRIO]) {
2377 			u32 prio;
2378 
2379 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2380 			tipc_link_set_prio(link, prio, &xmitq);
2381 		}
2382 		if (props[TIPC_NLA_PROP_WIN]) {
2383 			u32 win;
2384 
2385 			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2386 			tipc_link_set_queue_limits(link, win);
2387 		}
2388 	}
2389 
2390 out:
2391 	tipc_node_read_unlock(node);
2392 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
2393 			 NULL);
2394 	return res;
2395 }
2396 
2397 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2398 {
2399 	struct net *net = genl_info_net(info);
2400 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2401 	struct tipc_nl_msg msg;
2402 	char *name;
2403 	int err;
2404 
2405 	msg.portid = info->snd_portid;
2406 	msg.seq = info->snd_seq;
2407 
2408 	if (!info->attrs[TIPC_NLA_LINK])
2409 		return -EINVAL;
2410 
2411 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2412 					  info->attrs[TIPC_NLA_LINK],
2413 					  tipc_nl_link_policy, info->extack);
2414 	if (err)
2415 		return err;
2416 
2417 	if (!attrs[TIPC_NLA_LINK_NAME])
2418 		return -EINVAL;
2419 
2420 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2421 
2422 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2423 	if (!msg.skb)
2424 		return -ENOMEM;
2425 
2426 	if (strcmp(name, tipc_bclink_name) == 0) {
2427 		err = tipc_nl_add_bc_link(net, &msg);
2428 		if (err)
2429 			goto err_free;
2430 	} else {
2431 		int bearer_id;
2432 		struct tipc_node *node;
2433 		struct tipc_link *link;
2434 
2435 		node = tipc_node_find_by_name(net, name, &bearer_id);
2436 		if (!node) {
2437 			err = -EINVAL;
2438 			goto err_free;
2439 		}
2440 
2441 		tipc_node_read_lock(node);
2442 		link = node->links[bearer_id].link;
2443 		if (!link) {
2444 			tipc_node_read_unlock(node);
2445 			err = -EINVAL;
2446 			goto err_free;
2447 		}
2448 
2449 		err = __tipc_nl_add_link(net, &msg, link, 0);
2450 		tipc_node_read_unlock(node);
2451 		if (err)
2452 			goto err_free;
2453 	}
2454 
2455 	return genlmsg_reply(msg.skb, info);
2456 
2457 err_free:
2458 	nlmsg_free(msg.skb);
2459 	return err;
2460 }
2461 
2462 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2463 {
2464 	int err;
2465 	char *link_name;
2466 	unsigned int bearer_id;
2467 	struct tipc_link *link;
2468 	struct tipc_node *node;
2469 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2470 	struct net *net = sock_net(skb->sk);
2471 	struct tipc_link_entry *le;
2472 
2473 	if (!info->attrs[TIPC_NLA_LINK])
2474 		return -EINVAL;
2475 
2476 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2477 					  info->attrs[TIPC_NLA_LINK],
2478 					  tipc_nl_link_policy, info->extack);
2479 	if (err)
2480 		return err;
2481 
2482 	if (!attrs[TIPC_NLA_LINK_NAME])
2483 		return -EINVAL;
2484 
2485 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2486 
2487 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2488 		err = tipc_bclink_reset_stats(net);
2489 		if (err)
2490 			return err;
2491 		return 0;
2492 	}
2493 
2494 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2495 	if (!node)
2496 		return -EINVAL;
2497 
2498 	le = &node->links[bearer_id];
2499 	tipc_node_read_lock(node);
2500 	spin_lock_bh(&le->lock);
2501 	link = node->links[bearer_id].link;
2502 	if (!link) {
2503 		spin_unlock_bh(&le->lock);
2504 		tipc_node_read_unlock(node);
2505 		return -EINVAL;
2506 	}
2507 	tipc_link_reset_stats(link);
2508 	spin_unlock_bh(&le->lock);
2509 	tipc_node_read_unlock(node);
2510 	return 0;
2511 }
2512 
2513 /* Caller should hold node lock  */
2514 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2515 				    struct tipc_node *node, u32 *prev_link)
2516 {
2517 	u32 i;
2518 	int err;
2519 
2520 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2521 		*prev_link = i;
2522 
2523 		if (!node->links[i].link)
2524 			continue;
2525 
2526 		err = __tipc_nl_add_link(net, msg,
2527 					 node->links[i].link, NLM_F_MULTI);
2528 		if (err)
2529 			return err;
2530 	}
2531 	*prev_link = 0;
2532 
2533 	return 0;
2534 }
2535 
2536 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2537 {
2538 	struct net *net = sock_net(skb->sk);
2539 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2540 	struct tipc_node *node;
2541 	struct tipc_nl_msg msg;
2542 	u32 prev_node = cb->args[0];
2543 	u32 prev_link = cb->args[1];
2544 	int done = cb->args[2];
2545 	int err;
2546 
2547 	if (done)
2548 		return 0;
2549 
2550 	msg.skb = skb;
2551 	msg.portid = NETLINK_CB(cb->skb).portid;
2552 	msg.seq = cb->nlh->nlmsg_seq;
2553 
2554 	rcu_read_lock();
2555 	if (prev_node) {
2556 		node = tipc_node_find(net, prev_node);
2557 		if (!node) {
2558 			/* We never set seq or call nl_dump_check_consistent()
2559 			 * this means that setting prev_seq here will cause the
2560 			 * consistence check to fail in the netlink callback
2561 			 * handler. Resulting in the last NLMSG_DONE message
2562 			 * having the NLM_F_DUMP_INTR flag set.
2563 			 */
2564 			cb->prev_seq = 1;
2565 			goto out;
2566 		}
2567 		tipc_node_put(node);
2568 
2569 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2570 						 list) {
2571 			tipc_node_read_lock(node);
2572 			err = __tipc_nl_add_node_links(net, &msg, node,
2573 						       &prev_link);
2574 			tipc_node_read_unlock(node);
2575 			if (err)
2576 				goto out;
2577 
2578 			prev_node = node->addr;
2579 		}
2580 	} else {
2581 		err = tipc_nl_add_bc_link(net, &msg);
2582 		if (err)
2583 			goto out;
2584 
2585 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2586 			tipc_node_read_lock(node);
2587 			err = __tipc_nl_add_node_links(net, &msg, node,
2588 						       &prev_link);
2589 			tipc_node_read_unlock(node);
2590 			if (err)
2591 				goto out;
2592 
2593 			prev_node = node->addr;
2594 		}
2595 	}
2596 	done = 1;
2597 out:
2598 	rcu_read_unlock();
2599 
2600 	cb->args[0] = prev_node;
2601 	cb->args[1] = prev_link;
2602 	cb->args[2] = done;
2603 
2604 	return skb->len;
2605 }
2606 
2607 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2608 {
2609 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2610 	struct net *net = sock_net(skb->sk);
2611 	int err;
2612 
2613 	if (!info->attrs[TIPC_NLA_MON])
2614 		return -EINVAL;
2615 
2616 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2617 					  info->attrs[TIPC_NLA_MON],
2618 					  tipc_nl_monitor_policy,
2619 					  info->extack);
2620 	if (err)
2621 		return err;
2622 
2623 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2624 		u32 val;
2625 
2626 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2627 		err = tipc_nl_monitor_set_threshold(net, val);
2628 		if (err)
2629 			return err;
2630 	}
2631 
2632 	return 0;
2633 }
2634 
2635 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2636 {
2637 	struct nlattr *attrs;
2638 	void *hdr;
2639 	u32 val;
2640 
2641 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2642 			  0, TIPC_NL_MON_GET);
2643 	if (!hdr)
2644 		return -EMSGSIZE;
2645 
2646 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2647 	if (!attrs)
2648 		goto msg_full;
2649 
2650 	val = tipc_nl_monitor_get_threshold(net);
2651 
2652 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2653 		goto attr_msg_full;
2654 
2655 	nla_nest_end(msg->skb, attrs);
2656 	genlmsg_end(msg->skb, hdr);
2657 
2658 	return 0;
2659 
2660 attr_msg_full:
2661 	nla_nest_cancel(msg->skb, attrs);
2662 msg_full:
2663 	genlmsg_cancel(msg->skb, hdr);
2664 
2665 	return -EMSGSIZE;
2666 }
2667 
2668 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2669 {
2670 	struct net *net = sock_net(skb->sk);
2671 	struct tipc_nl_msg msg;
2672 	int err;
2673 
2674 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2675 	if (!msg.skb)
2676 		return -ENOMEM;
2677 	msg.portid = info->snd_portid;
2678 	msg.seq = info->snd_seq;
2679 
2680 	err = __tipc_nl_add_monitor_prop(net, &msg);
2681 	if (err) {
2682 		nlmsg_free(msg.skb);
2683 		return err;
2684 	}
2685 
2686 	return genlmsg_reply(msg.skb, info);
2687 }
2688 
2689 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2690 {
2691 	struct net *net = sock_net(skb->sk);
2692 	u32 prev_bearer = cb->args[0];
2693 	struct tipc_nl_msg msg;
2694 	int bearer_id;
2695 	int err;
2696 
2697 	if (prev_bearer == MAX_BEARERS)
2698 		return 0;
2699 
2700 	msg.skb = skb;
2701 	msg.portid = NETLINK_CB(cb->skb).portid;
2702 	msg.seq = cb->nlh->nlmsg_seq;
2703 
2704 	rtnl_lock();
2705 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2706 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2707 		if (err)
2708 			break;
2709 	}
2710 	rtnl_unlock();
2711 	cb->args[0] = bearer_id;
2712 
2713 	return skb->len;
2714 }
2715 
2716 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2717 				   struct netlink_callback *cb)
2718 {
2719 	struct net *net = sock_net(skb->sk);
2720 	u32 prev_node = cb->args[1];
2721 	u32 bearer_id = cb->args[2];
2722 	int done = cb->args[0];
2723 	struct tipc_nl_msg msg;
2724 	int err;
2725 
2726 	if (!prev_node) {
2727 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2728 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2729 
2730 		if (!attrs[TIPC_NLA_MON])
2731 			return -EINVAL;
2732 
2733 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2734 						  attrs[TIPC_NLA_MON],
2735 						  tipc_nl_monitor_policy,
2736 						  NULL);
2737 		if (err)
2738 			return err;
2739 
2740 		if (!mon[TIPC_NLA_MON_REF])
2741 			return -EINVAL;
2742 
2743 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2744 
2745 		if (bearer_id >= MAX_BEARERS)
2746 			return -EINVAL;
2747 	}
2748 
2749 	if (done)
2750 		return 0;
2751 
2752 	msg.skb = skb;
2753 	msg.portid = NETLINK_CB(cb->skb).portid;
2754 	msg.seq = cb->nlh->nlmsg_seq;
2755 
2756 	rtnl_lock();
2757 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2758 	if (!err)
2759 		done = 1;
2760 
2761 	rtnl_unlock();
2762 	cb->args[0] = done;
2763 	cb->args[1] = prev_node;
2764 	cb->args[2] = bearer_id;
2765 
2766 	return skb->len;
2767 }
2768 
2769 #ifdef CONFIG_TIPC_CRYPTO
2770 static int tipc_nl_retrieve_key(struct nlattr **attrs,
2771 				struct tipc_aead_key **key)
2772 {
2773 	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
2774 
2775 	if (!attr)
2776 		return -ENODATA;
2777 
2778 	*key = (struct tipc_aead_key *)nla_data(attr);
2779 	if (nla_len(attr) < tipc_aead_key_size(*key))
2780 		return -EINVAL;
2781 
2782 	return 0;
2783 }
2784 
2785 static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
2786 {
2787 	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
2788 
2789 	if (!attr)
2790 		return -ENODATA;
2791 
2792 	if (nla_len(attr) < TIPC_NODEID_LEN)
2793 		return -EINVAL;
2794 
2795 	*node_id = (u8 *)nla_data(attr);
2796 	return 0;
2797 }
2798 
2799 int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2800 {
2801 	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
2802 	struct net *net = sock_net(skb->sk);
2803 	struct tipc_net *tn = tipc_net(net);
2804 	struct tipc_node *n = NULL;
2805 	struct tipc_aead_key *ukey;
2806 	struct tipc_crypto *c;
2807 	u8 *id, *own_id;
2808 	int rc = 0;
2809 
2810 	if (!info->attrs[TIPC_NLA_NODE])
2811 		return -EINVAL;
2812 
2813 	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
2814 			      info->attrs[TIPC_NLA_NODE],
2815 			      tipc_nl_node_policy, info->extack);
2816 	if (rc)
2817 		goto exit;
2818 
2819 	own_id = tipc_own_id(net);
2820 	if (!own_id) {
2821 		rc = -EPERM;
2822 		goto exit;
2823 	}
2824 
2825 	rc = tipc_nl_retrieve_key(attrs, &ukey);
2826 	if (rc)
2827 		goto exit;
2828 
2829 	rc = tipc_aead_key_validate(ukey);
2830 	if (rc)
2831 		goto exit;
2832 
2833 	rc = tipc_nl_retrieve_nodeid(attrs, &id);
2834 	switch (rc) {
2835 	case -ENODATA:
2836 		/* Cluster key mode */
2837 		rc = tipc_crypto_key_init(tn->crypto_tx, ukey, CLUSTER_KEY);
2838 		break;
2839 	case 0:
2840 		/* Per-node key mode */
2841 		if (!memcmp(id, own_id, NODE_ID_LEN)) {
2842 			c = tn->crypto_tx;
2843 		} else {
2844 			n = tipc_node_find_by_id(net, id) ?:
2845 				tipc_node_create(net, 0, id, 0xffffu, 0, true);
2846 			if (unlikely(!n)) {
2847 				rc = -ENOMEM;
2848 				break;
2849 			}
2850 			c = n->crypto_rx;
2851 		}
2852 
2853 		rc = tipc_crypto_key_init(c, ukey, PER_NODE_KEY);
2854 		if (n)
2855 			tipc_node_put(n);
2856 		break;
2857 	default:
2858 		break;
2859 	}
2860 
2861 exit:
2862 	return (rc < 0) ? rc : 0;
2863 }
2864 
2865 int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2866 {
2867 	int err;
2868 
2869 	rtnl_lock();
2870 	err = __tipc_nl_node_set_key(skb, info);
2871 	rtnl_unlock();
2872 
2873 	return err;
2874 }
2875 
2876 int __tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
2877 {
2878 	struct net *net = sock_net(skb->sk);
2879 	struct tipc_net *tn = tipc_net(net);
2880 	struct tipc_node *n;
2881 
2882 	tipc_crypto_key_flush(tn->crypto_tx);
2883 	rcu_read_lock();
2884 	list_for_each_entry_rcu(n, &tn->node_list, list)
2885 		tipc_crypto_key_flush(n->crypto_rx);
2886 	rcu_read_unlock();
2887 
2888 	pr_info("All keys are flushed!\n");
2889 	return 0;
2890 }
2891 
2892 int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
2893 {
2894 	int err;
2895 
2896 	rtnl_lock();
2897 	err = __tipc_nl_node_flush_key(skb, info);
2898 	rtnl_unlock();
2899 
2900 	return err;
2901 }
2902 #endif
2903 
2904 /**
2905  * tipc_node_dump - dump TIPC node data
2906  * @n: tipc node to be dumped
2907  * @more: dump more?
2908  *        - false: dump only tipc node data
2909  *        - true: dump node link data as well
2910  * @buf: returned buffer of dump data in format
2911  */
2912 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2913 {
2914 	int i = 0;
2915 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2916 
2917 	if (!n) {
2918 		i += scnprintf(buf, sz, "node data: (null)\n");
2919 		return i;
2920 	}
2921 
2922 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2923 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2924 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2925 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2926 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
2927 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
2928 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
2929 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
2930 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
2931 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
2932 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
2933 
2934 	if (!more)
2935 		return i;
2936 
2937 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
2938 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
2939 	i += scnprintf(buf + i, sz - i, " media: ");
2940 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
2941 	i += scnprintf(buf + i, sz - i, "\n");
2942 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
2943 	i += scnprintf(buf + i, sz - i, " inputq: ");
2944 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
2945 
2946 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
2947 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
2948 	i += scnprintf(buf + i, sz - i, " media: ");
2949 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
2950 	i += scnprintf(buf + i, sz - i, "\n");
2951 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
2952 	i += scnprintf(buf + i, sz - i, " inputq: ");
2953 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
2954 
2955 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
2956 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
2957 
2958 	return i;
2959 }
2960 
2961 void tipc_node_pre_cleanup_net(struct net *exit_net)
2962 {
2963 	struct tipc_node *n;
2964 	struct tipc_net *tn;
2965 	struct net *tmp;
2966 
2967 	rcu_read_lock();
2968 	for_each_net_rcu(tmp) {
2969 		if (tmp == exit_net)
2970 			continue;
2971 		tn = tipc_net(tmp);
2972 		if (!tn)
2973 			continue;
2974 		spin_lock_bh(&tn->node_list_lock);
2975 		list_for_each_entry_rcu(n, &tn->node_list, list) {
2976 			if (!n->peer_net)
2977 				continue;
2978 			if (n->peer_net != exit_net)
2979 				continue;
2980 			tipc_node_write_lock(n);
2981 			n->peer_net = NULL;
2982 			n->peer_hash_mix = 0;
2983 			tipc_node_write_unlock_fast(n);
2984 			break;
2985 		}
2986 		spin_unlock_bh(&tn->node_list_lock);
2987 	}
2988 	rcu_read_unlock();
2989 }
2990