xref: /openbmc/linux/net/tipc/node.c (revision ce746d43)
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  * @ref: 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  * @action_flags: bit mask of different types of node actions
94  * @state: connectivity state vs peer node
95  * @preliminary: a preliminary node or not
96  * @sync_point: sequence number where synch/failover is finished
97  * @list: links to adjacent nodes in sorted list of cluster's nodes
98  * @working_links: number of working links to node (both active and standby)
99  * @link_cnt: number of links to node
100  * @capabilities: bitmap, indicating peer node's functional capabilities
101  * @signature: node instance identifier
102  * @link_id: local and remote bearer ids of changing link, if any
103  * @publ_list: list of publications
104  * @rcu: rcu struct for tipc_node
105  * @delete_at: indicates the time for deleting a down node
106  * @crypto_rx: RX crypto handler
107  */
108 struct tipc_node {
109 	u32 addr;
110 	struct kref kref;
111 	rwlock_t lock;
112 	struct net *net;
113 	struct hlist_node hash;
114 	int active_links[2];
115 	struct tipc_link_entry links[MAX_BEARERS];
116 	struct tipc_bclink_entry bc_entry;
117 	int action_flags;
118 	struct list_head list;
119 	int state;
120 	bool preliminary;
121 	bool failover_sent;
122 	u16 sync_point;
123 	int link_cnt;
124 	u16 working_links;
125 	u16 capabilities;
126 	u32 signature;
127 	u32 link_id;
128 	u8 peer_id[16];
129 	char peer_id_string[NODE_ID_STR_LEN];
130 	struct list_head publ_list;
131 	struct list_head conn_sks;
132 	unsigned long keepalive_intv;
133 	struct timer_list timer;
134 	struct rcu_head rcu;
135 	unsigned long delete_at;
136 	struct net *peer_net;
137 	u32 peer_hash_mix;
138 #ifdef CONFIG_TIPC_CRYPTO
139 	struct tipc_crypto *crypto_rx;
140 #endif
141 };
142 
143 /* Node FSM states and events:
144  */
145 enum {
146 	SELF_DOWN_PEER_DOWN    = 0xdd,
147 	SELF_UP_PEER_UP        = 0xaa,
148 	SELF_DOWN_PEER_LEAVING = 0xd1,
149 	SELF_UP_PEER_COMING    = 0xac,
150 	SELF_COMING_PEER_UP    = 0xca,
151 	SELF_LEAVING_PEER_DOWN = 0x1d,
152 	NODE_FAILINGOVER       = 0xf0,
153 	NODE_SYNCHING          = 0xcc
154 };
155 
156 enum {
157 	SELF_ESTABL_CONTACT_EVT = 0xece,
158 	SELF_LOST_CONTACT_EVT   = 0x1ce,
159 	PEER_ESTABL_CONTACT_EVT = 0x9ece,
160 	PEER_LOST_CONTACT_EVT   = 0x91ce,
161 	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
162 	NODE_FAILOVER_END_EVT   = 0xfee,
163 	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
164 	NODE_SYNCH_END_EVT      = 0xcee
165 };
166 
167 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
168 				  struct sk_buff_head *xmitq,
169 				  struct tipc_media_addr **maddr);
170 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
171 				bool delete);
172 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
173 static void tipc_node_delete(struct tipc_node *node);
174 static void tipc_node_timeout(struct timer_list *t);
175 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
176 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
177 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
178 static bool node_is_up(struct tipc_node *n);
179 static void tipc_node_delete_from_list(struct tipc_node *node);
180 
181 struct tipc_sock_conn {
182 	u32 port;
183 	u32 peer_port;
184 	u32 peer_node;
185 	struct list_head list;
186 };
187 
188 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
189 {
190 	int bearer_id = n->active_links[sel & 1];
191 
192 	if (unlikely(bearer_id == INVALID_BEARER_ID))
193 		return NULL;
194 
195 	return n->links[bearer_id].link;
196 }
197 
198 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel, bool connected)
199 {
200 	struct tipc_node *n;
201 	int bearer_id;
202 	unsigned int mtu = MAX_MSG_SIZE;
203 
204 	n = tipc_node_find(net, addr);
205 	if (unlikely(!n))
206 		return mtu;
207 
208 	/* Allow MAX_MSG_SIZE when building connection oriented message
209 	 * if they are in the same core network
210 	 */
211 	if (n->peer_net && connected) {
212 		tipc_node_put(n);
213 		return mtu;
214 	}
215 
216 	bearer_id = n->active_links[sel & 1];
217 	if (likely(bearer_id != INVALID_BEARER_ID))
218 		mtu = n->links[bearer_id].mtu;
219 	tipc_node_put(n);
220 	return mtu;
221 }
222 
223 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
224 {
225 	u8 *own_id = tipc_own_id(net);
226 	struct tipc_node *n;
227 
228 	if (!own_id)
229 		return true;
230 
231 	if (addr == tipc_own_addr(net)) {
232 		memcpy(id, own_id, TIPC_NODEID_LEN);
233 		return true;
234 	}
235 	n = tipc_node_find(net, addr);
236 	if (!n)
237 		return false;
238 
239 	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
240 	tipc_node_put(n);
241 	return true;
242 }
243 
244 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
245 {
246 	struct tipc_node *n;
247 	u16 caps;
248 
249 	n = tipc_node_find(net, addr);
250 	if (unlikely(!n))
251 		return TIPC_NODE_CAPABILITIES;
252 	caps = n->capabilities;
253 	tipc_node_put(n);
254 	return caps;
255 }
256 
257 u32 tipc_node_get_addr(struct tipc_node *node)
258 {
259 	return (node) ? node->addr : 0;
260 }
261 
262 char *tipc_node_get_id_str(struct tipc_node *node)
263 {
264 	return node->peer_id_string;
265 }
266 
267 #ifdef CONFIG_TIPC_CRYPTO
268 /**
269  * tipc_node_crypto_rx - Retrieve crypto RX handle from node
270  * Note: node ref counter must be held first!
271  */
272 struct tipc_crypto *tipc_node_crypto_rx(struct tipc_node *__n)
273 {
274 	return (__n) ? __n->crypto_rx : NULL;
275 }
276 
277 struct tipc_crypto *tipc_node_crypto_rx_by_list(struct list_head *pos)
278 {
279 	return container_of(pos, struct tipc_node, list)->crypto_rx;
280 }
281 #endif
282 
283 static void tipc_node_free(struct rcu_head *rp)
284 {
285 	struct tipc_node *n = container_of(rp, struct tipc_node, rcu);
286 
287 #ifdef CONFIG_TIPC_CRYPTO
288 	tipc_crypto_stop(&n->crypto_rx);
289 #endif
290 	kfree(n);
291 }
292 
293 static void tipc_node_kref_release(struct kref *kref)
294 {
295 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
296 
297 	kfree(n->bc_entry.link);
298 	call_rcu(&n->rcu, tipc_node_free);
299 }
300 
301 void tipc_node_put(struct tipc_node *node)
302 {
303 	kref_put(&node->kref, tipc_node_kref_release);
304 }
305 
306 static void tipc_node_get(struct tipc_node *node)
307 {
308 	kref_get(&node->kref);
309 }
310 
311 /*
312  * tipc_node_find - locate specified node object, if it exists
313  */
314 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
315 {
316 	struct tipc_net *tn = tipc_net(net);
317 	struct tipc_node *node;
318 	unsigned int thash = tipc_hashfn(addr);
319 
320 	rcu_read_lock();
321 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
322 		if (node->addr != addr || node->preliminary)
323 			continue;
324 		if (!kref_get_unless_zero(&node->kref))
325 			node = NULL;
326 		break;
327 	}
328 	rcu_read_unlock();
329 	return node;
330 }
331 
332 /* tipc_node_find_by_id - locate specified node object by its 128-bit id
333  * Note: this function is called only when a discovery request failed
334  * to find the node by its 32-bit id, and is not time critical
335  */
336 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
337 {
338 	struct tipc_net *tn = tipc_net(net);
339 	struct tipc_node *n;
340 	bool found = false;
341 
342 	rcu_read_lock();
343 	list_for_each_entry_rcu(n, &tn->node_list, list) {
344 		read_lock_bh(&n->lock);
345 		if (!memcmp(id, n->peer_id, 16) &&
346 		    kref_get_unless_zero(&n->kref))
347 			found = true;
348 		read_unlock_bh(&n->lock);
349 		if (found)
350 			break;
351 	}
352 	rcu_read_unlock();
353 	return found ? n : NULL;
354 }
355 
356 static void tipc_node_read_lock(struct tipc_node *n)
357 {
358 	read_lock_bh(&n->lock);
359 }
360 
361 static void tipc_node_read_unlock(struct tipc_node *n)
362 {
363 	read_unlock_bh(&n->lock);
364 }
365 
366 static void tipc_node_write_lock(struct tipc_node *n)
367 {
368 	write_lock_bh(&n->lock);
369 }
370 
371 static void tipc_node_write_unlock_fast(struct tipc_node *n)
372 {
373 	write_unlock_bh(&n->lock);
374 }
375 
376 static void tipc_node_write_unlock(struct tipc_node *n)
377 {
378 	struct net *net = n->net;
379 	u32 addr = 0;
380 	u32 flags = n->action_flags;
381 	u32 link_id = 0;
382 	u32 bearer_id;
383 	struct list_head *publ_list;
384 
385 	if (likely(!flags)) {
386 		write_unlock_bh(&n->lock);
387 		return;
388 	}
389 
390 	addr = n->addr;
391 	link_id = n->link_id;
392 	bearer_id = link_id & 0xffff;
393 	publ_list = &n->publ_list;
394 
395 	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
396 			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
397 
398 	write_unlock_bh(&n->lock);
399 
400 	if (flags & TIPC_NOTIFY_NODE_DOWN)
401 		tipc_publ_notify(net, publ_list, addr, n->capabilities);
402 
403 	if (flags & TIPC_NOTIFY_NODE_UP)
404 		tipc_named_node_up(net, addr, n->capabilities);
405 
406 	if (flags & TIPC_NOTIFY_LINK_UP) {
407 		tipc_mon_peer_up(net, addr, bearer_id);
408 		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
409 				     TIPC_NODE_SCOPE, link_id, link_id);
410 	}
411 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
412 		tipc_mon_peer_down(net, addr, bearer_id);
413 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
414 				      addr, link_id);
415 	}
416 }
417 
418 static void tipc_node_assign_peer_net(struct tipc_node *n, u32 hash_mixes)
419 {
420 	int net_id = tipc_netid(n->net);
421 	struct tipc_net *tn_peer;
422 	struct net *tmp;
423 	u32 hash_chk;
424 
425 	if (n->peer_net)
426 		return;
427 
428 	for_each_net_rcu(tmp) {
429 		tn_peer = tipc_net(tmp);
430 		if (!tn_peer)
431 			continue;
432 		/* Integrity checking whether node exists in namespace or not */
433 		if (tn_peer->net_id != net_id)
434 			continue;
435 		if (memcmp(n->peer_id, tn_peer->node_id, NODE_ID_LEN))
436 			continue;
437 		hash_chk = tipc_net_hash_mixes(tmp, tn_peer->random);
438 		if (hash_mixes ^ hash_chk)
439 			continue;
440 		n->peer_net = tmp;
441 		n->peer_hash_mix = hash_mixes;
442 		break;
443 	}
444 }
445 
446 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u8 *peer_id,
447 				   u16 capabilities, u32 hash_mixes,
448 				   bool preliminary)
449 {
450 	struct tipc_net *tn = net_generic(net, tipc_net_id);
451 	struct tipc_node *n, *temp_node;
452 	struct tipc_link *l;
453 	unsigned long intv;
454 	int bearer_id;
455 	int i;
456 
457 	spin_lock_bh(&tn->node_list_lock);
458 	n = tipc_node_find(net, addr) ?:
459 		tipc_node_find_by_id(net, peer_id);
460 	if (n) {
461 		if (!n->preliminary)
462 			goto update;
463 		if (preliminary)
464 			goto exit;
465 		/* A preliminary node becomes "real" now, refresh its data */
466 		tipc_node_write_lock(n);
467 		n->preliminary = false;
468 		n->addr = addr;
469 		hlist_del_rcu(&n->hash);
470 		hlist_add_head_rcu(&n->hash,
471 				   &tn->node_htable[tipc_hashfn(addr)]);
472 		list_del_rcu(&n->list);
473 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
474 			if (n->addr < temp_node->addr)
475 				break;
476 		}
477 		list_add_tail_rcu(&n->list, &temp_node->list);
478 		tipc_node_write_unlock_fast(n);
479 
480 update:
481 		if (n->peer_hash_mix ^ hash_mixes)
482 			tipc_node_assign_peer_net(n, hash_mixes);
483 		if (n->capabilities == capabilities)
484 			goto exit;
485 		/* Same node may come back with new capabilities */
486 		tipc_node_write_lock(n);
487 		n->capabilities = capabilities;
488 		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
489 			l = n->links[bearer_id].link;
490 			if (l)
491 				tipc_link_update_caps(l, capabilities);
492 		}
493 		tipc_node_write_unlock_fast(n);
494 
495 		/* Calculate cluster capabilities */
496 		tn->capabilities = TIPC_NODE_CAPABILITIES;
497 		list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
498 			tn->capabilities &= temp_node->capabilities;
499 		}
500 
501 		tipc_bcast_toggle_rcast(net,
502 					(tn->capabilities & TIPC_BCAST_RCAST));
503 
504 		goto exit;
505 	}
506 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
507 	if (!n) {
508 		pr_warn("Node creation failed, no memory\n");
509 		goto exit;
510 	}
511 	tipc_nodeid2string(n->peer_id_string, peer_id);
512 #ifdef CONFIG_TIPC_CRYPTO
513 	if (unlikely(tipc_crypto_start(&n->crypto_rx, net, n))) {
514 		pr_warn("Failed to start crypto RX(%s)!\n", n->peer_id_string);
515 		kfree(n);
516 		n = NULL;
517 		goto exit;
518 	}
519 #endif
520 	n->addr = addr;
521 	n->preliminary = preliminary;
522 	memcpy(&n->peer_id, peer_id, 16);
523 	n->net = net;
524 	n->peer_net = NULL;
525 	n->peer_hash_mix = 0;
526 	/* Assign kernel local namespace if exists */
527 	tipc_node_assign_peer_net(n, hash_mixes);
528 	n->capabilities = capabilities;
529 	kref_init(&n->kref);
530 	rwlock_init(&n->lock);
531 	INIT_HLIST_NODE(&n->hash);
532 	INIT_LIST_HEAD(&n->list);
533 	INIT_LIST_HEAD(&n->publ_list);
534 	INIT_LIST_HEAD(&n->conn_sks);
535 	skb_queue_head_init(&n->bc_entry.namedq);
536 	skb_queue_head_init(&n->bc_entry.inputq1);
537 	__skb_queue_head_init(&n->bc_entry.arrvq);
538 	skb_queue_head_init(&n->bc_entry.inputq2);
539 	for (i = 0; i < MAX_BEARERS; i++)
540 		spin_lock_init(&n->links[i].lock);
541 	n->state = SELF_DOWN_PEER_LEAVING;
542 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
543 	n->signature = INVALID_NODE_SIG;
544 	n->active_links[0] = INVALID_BEARER_ID;
545 	n->active_links[1] = INVALID_BEARER_ID;
546 	n->bc_entry.link = NULL;
547 	tipc_node_get(n);
548 	timer_setup(&n->timer, tipc_node_timeout, 0);
549 	/* Start a slow timer anyway, crypto needs it */
550 	n->keepalive_intv = 10000;
551 	intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
552 	if (!mod_timer(&n->timer, intv))
553 		tipc_node_get(n);
554 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
555 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
556 		if (n->addr < temp_node->addr)
557 			break;
558 	}
559 	list_add_tail_rcu(&n->list, &temp_node->list);
560 	/* Calculate cluster capabilities */
561 	tn->capabilities = TIPC_NODE_CAPABILITIES;
562 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
563 		tn->capabilities &= temp_node->capabilities;
564 	}
565 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
566 	trace_tipc_node_create(n, true, " ");
567 exit:
568 	spin_unlock_bh(&tn->node_list_lock);
569 	return n;
570 }
571 
572 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
573 {
574 	unsigned long tol = tipc_link_tolerance(l);
575 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
576 
577 	/* Link with lowest tolerance determines timer interval */
578 	if (intv < n->keepalive_intv)
579 		n->keepalive_intv = intv;
580 
581 	/* Ensure link's abort limit corresponds to current tolerance */
582 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
583 }
584 
585 static void tipc_node_delete_from_list(struct tipc_node *node)
586 {
587 	list_del_rcu(&node->list);
588 	hlist_del_rcu(&node->hash);
589 	tipc_node_put(node);
590 }
591 
592 static void tipc_node_delete(struct tipc_node *node)
593 {
594 	trace_tipc_node_delete(node, true, " ");
595 	tipc_node_delete_from_list(node);
596 
597 	del_timer_sync(&node->timer);
598 	tipc_node_put(node);
599 }
600 
601 void tipc_node_stop(struct net *net)
602 {
603 	struct tipc_net *tn = tipc_net(net);
604 	struct tipc_node *node, *t_node;
605 
606 	spin_lock_bh(&tn->node_list_lock);
607 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
608 		tipc_node_delete(node);
609 	spin_unlock_bh(&tn->node_list_lock);
610 }
611 
612 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
613 {
614 	struct tipc_node *n;
615 
616 	if (in_own_node(net, addr))
617 		return;
618 
619 	n = tipc_node_find(net, addr);
620 	if (!n) {
621 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
622 		return;
623 	}
624 	tipc_node_write_lock(n);
625 	list_add_tail(subscr, &n->publ_list);
626 	tipc_node_write_unlock_fast(n);
627 	tipc_node_put(n);
628 }
629 
630 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
631 {
632 	struct tipc_node *n;
633 
634 	if (in_own_node(net, addr))
635 		return;
636 
637 	n = tipc_node_find(net, addr);
638 	if (!n) {
639 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
640 		return;
641 	}
642 	tipc_node_write_lock(n);
643 	list_del_init(subscr);
644 	tipc_node_write_unlock_fast(n);
645 	tipc_node_put(n);
646 }
647 
648 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
649 {
650 	struct tipc_node *node;
651 	struct tipc_sock_conn *conn;
652 	int err = 0;
653 
654 	if (in_own_node(net, dnode))
655 		return 0;
656 
657 	node = tipc_node_find(net, dnode);
658 	if (!node) {
659 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
660 		return -EHOSTUNREACH;
661 	}
662 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
663 	if (!conn) {
664 		err = -EHOSTUNREACH;
665 		goto exit;
666 	}
667 	conn->peer_node = dnode;
668 	conn->port = port;
669 	conn->peer_port = peer_port;
670 
671 	tipc_node_write_lock(node);
672 	list_add_tail(&conn->list, &node->conn_sks);
673 	tipc_node_write_unlock(node);
674 exit:
675 	tipc_node_put(node);
676 	return err;
677 }
678 
679 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
680 {
681 	struct tipc_node *node;
682 	struct tipc_sock_conn *conn, *safe;
683 
684 	if (in_own_node(net, dnode))
685 		return;
686 
687 	node = tipc_node_find(net, dnode);
688 	if (!node)
689 		return;
690 
691 	tipc_node_write_lock(node);
692 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
693 		if (port != conn->port)
694 			continue;
695 		list_del(&conn->list);
696 		kfree(conn);
697 	}
698 	tipc_node_write_unlock(node);
699 	tipc_node_put(node);
700 }
701 
702 static void  tipc_node_clear_links(struct tipc_node *node)
703 {
704 	int i;
705 
706 	for (i = 0; i < MAX_BEARERS; i++) {
707 		struct tipc_link_entry *le = &node->links[i];
708 
709 		if (le->link) {
710 			kfree(le->link);
711 			le->link = NULL;
712 			node->link_cnt--;
713 		}
714 	}
715 }
716 
717 /* tipc_node_cleanup - delete nodes that does not
718  * have active links for NODE_CLEANUP_AFTER time
719  */
720 static bool tipc_node_cleanup(struct tipc_node *peer)
721 {
722 	struct tipc_node *temp_node;
723 	struct tipc_net *tn = tipc_net(peer->net);
724 	bool deleted = false;
725 
726 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
727 	if (!spin_trylock_bh(&tn->node_list_lock))
728 		return false;
729 
730 	tipc_node_write_lock(peer);
731 
732 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
733 		tipc_node_clear_links(peer);
734 		tipc_node_delete_from_list(peer);
735 		deleted = true;
736 	}
737 	tipc_node_write_unlock(peer);
738 
739 	if (!deleted) {
740 		spin_unlock_bh(&tn->node_list_lock);
741 		return deleted;
742 	}
743 
744 	/* Calculate cluster capabilities */
745 	tn->capabilities = TIPC_NODE_CAPABILITIES;
746 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
747 		tn->capabilities &= temp_node->capabilities;
748 	}
749 	tipc_bcast_toggle_rcast(peer->net,
750 				(tn->capabilities & TIPC_BCAST_RCAST));
751 	spin_unlock_bh(&tn->node_list_lock);
752 	return deleted;
753 }
754 
755 /* tipc_node_timeout - handle expiration of node timer
756  */
757 static void tipc_node_timeout(struct timer_list *t)
758 {
759 	struct tipc_node *n = from_timer(n, t, timer);
760 	struct tipc_link_entry *le;
761 	struct sk_buff_head xmitq;
762 	int remains = n->link_cnt;
763 	int bearer_id;
764 	int rc = 0;
765 
766 	trace_tipc_node_timeout(n, false, " ");
767 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
768 		/*Removing the reference of Timer*/
769 		tipc_node_put(n);
770 		return;
771 	}
772 
773 #ifdef CONFIG_TIPC_CRYPTO
774 	/* Take any crypto key related actions first */
775 	tipc_crypto_timeout(n->crypto_rx);
776 #endif
777 	__skb_queue_head_init(&xmitq);
778 
779 	/* Initial node interval to value larger (10 seconds), then it will be
780 	 * recalculated with link lowest tolerance
781 	 */
782 	tipc_node_read_lock(n);
783 	n->keepalive_intv = 10000;
784 	tipc_node_read_unlock(n);
785 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
786 		tipc_node_read_lock(n);
787 		le = &n->links[bearer_id];
788 		if (le->link) {
789 			spin_lock_bh(&le->lock);
790 			/* Link tolerance may change asynchronously: */
791 			tipc_node_calculate_timer(n, le->link);
792 			rc = tipc_link_timeout(le->link, &xmitq);
793 			spin_unlock_bh(&le->lock);
794 			remains--;
795 		}
796 		tipc_node_read_unlock(n);
797 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr, n);
798 		if (rc & TIPC_LINK_DOWN_EVT)
799 			tipc_node_link_down(n, bearer_id, false);
800 	}
801 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
802 }
803 
804 /**
805  * __tipc_node_link_up - handle addition of link
806  * Node lock must be held by caller
807  * Link becomes active (alone or shared) or standby, depending on its priority.
808  */
809 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
810 				struct sk_buff_head *xmitq)
811 {
812 	int *slot0 = &n->active_links[0];
813 	int *slot1 = &n->active_links[1];
814 	struct tipc_link *ol = node_active_link(n, 0);
815 	struct tipc_link *nl = n->links[bearer_id].link;
816 
817 	if (!nl || tipc_link_is_up(nl))
818 		return;
819 
820 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
821 	if (!tipc_link_is_up(nl))
822 		return;
823 
824 	n->working_links++;
825 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
826 	n->link_id = tipc_link_id(nl);
827 
828 	/* Leave room for tunnel header when returning 'mtu' to users: */
829 	n->links[bearer_id].mtu = tipc_link_mss(nl);
830 
831 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
832 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
833 
834 	pr_debug("Established link <%s> on network plane %c\n",
835 		 tipc_link_name(nl), tipc_link_plane(nl));
836 	trace_tipc_node_link_up(n, true, " ");
837 
838 	/* Ensure that a STATE message goes first */
839 	tipc_link_build_state_msg(nl, xmitq);
840 
841 	/* First link? => give it both slots */
842 	if (!ol) {
843 		*slot0 = bearer_id;
844 		*slot1 = bearer_id;
845 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
846 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
847 		tipc_link_set_active(nl, true);
848 		tipc_bcast_add_peer(n->net, nl, xmitq);
849 		return;
850 	}
851 
852 	/* Second link => redistribute slots */
853 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
854 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
855 		*slot0 = bearer_id;
856 		*slot1 = bearer_id;
857 		tipc_link_set_active(nl, true);
858 		tipc_link_set_active(ol, false);
859 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
860 		tipc_link_set_active(nl, true);
861 		*slot1 = bearer_id;
862 	} else {
863 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
864 	}
865 
866 	/* Prepare synchronization with first link */
867 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
868 }
869 
870 /**
871  * tipc_node_link_up - handle addition of link
872  *
873  * Link becomes active (alone or shared) or standby, depending on its priority.
874  */
875 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
876 			      struct sk_buff_head *xmitq)
877 {
878 	struct tipc_media_addr *maddr;
879 
880 	tipc_node_write_lock(n);
881 	__tipc_node_link_up(n, bearer_id, xmitq);
882 	maddr = &n->links[bearer_id].maddr;
883 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr, n);
884 	tipc_node_write_unlock(n);
885 }
886 
887 /**
888  * tipc_node_link_failover() - start failover in case "half-failover"
889  *
890  * This function is only called in a very special situation where link
891  * failover can be already started on peer node but not on this node.
892  * This can happen when e.g.
893  *	1. Both links <1A-2A>, <1B-2B> down
894  *	2. Link endpoint 2A up, but 1A still down (e.g. due to network
895  *	   disturbance, wrong session, etc.)
896  *	3. Link <1B-2B> up
897  *	4. Link endpoint 2A down (e.g. due to link tolerance timeout)
898  *	5. Node 2 starts failover onto link <1B-2B>
899  *
900  *	==> Node 1 does never start link/node failover!
901  *
902  * @n: tipc node structure
903  * @l: link peer endpoint failingover (- can be NULL)
904  * @tnl: tunnel link
905  * @xmitq: queue for messages to be xmited on tnl link later
906  */
907 static void tipc_node_link_failover(struct tipc_node *n, struct tipc_link *l,
908 				    struct tipc_link *tnl,
909 				    struct sk_buff_head *xmitq)
910 {
911 	/* Avoid to be "self-failover" that can never end */
912 	if (!tipc_link_is_up(tnl))
913 		return;
914 
915 	/* Don't rush, failure link may be in the process of resetting */
916 	if (l && !tipc_link_is_reset(l))
917 		return;
918 
919 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
920 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
921 
922 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
923 	tipc_link_failover_prepare(l, tnl, xmitq);
924 
925 	if (l)
926 		tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
927 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
928 }
929 
930 /**
931  * __tipc_node_link_down - handle loss of link
932  */
933 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
934 				  struct sk_buff_head *xmitq,
935 				  struct tipc_media_addr **maddr)
936 {
937 	struct tipc_link_entry *le = &n->links[*bearer_id];
938 	int *slot0 = &n->active_links[0];
939 	int *slot1 = &n->active_links[1];
940 	int i, highest = 0, prio;
941 	struct tipc_link *l, *_l, *tnl;
942 
943 	l = n->links[*bearer_id].link;
944 	if (!l || tipc_link_is_reset(l))
945 		return;
946 
947 	n->working_links--;
948 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
949 	n->link_id = tipc_link_id(l);
950 
951 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
952 
953 	pr_debug("Lost link <%s> on network plane %c\n",
954 		 tipc_link_name(l), tipc_link_plane(l));
955 
956 	/* Select new active link if any available */
957 	*slot0 = INVALID_BEARER_ID;
958 	*slot1 = INVALID_BEARER_ID;
959 	for (i = 0; i < MAX_BEARERS; i++) {
960 		_l = n->links[i].link;
961 		if (!_l || !tipc_link_is_up(_l))
962 			continue;
963 		if (_l == l)
964 			continue;
965 		prio = tipc_link_prio(_l);
966 		if (prio < highest)
967 			continue;
968 		if (prio > highest) {
969 			highest = prio;
970 			*slot0 = i;
971 			*slot1 = i;
972 			continue;
973 		}
974 		*slot1 = i;
975 	}
976 
977 	if (!node_is_up(n)) {
978 		if (tipc_link_peer_is_down(l))
979 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
980 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
981 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down!");
982 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
983 		tipc_link_reset(l);
984 		tipc_link_build_reset_msg(l, xmitq);
985 		*maddr = &n->links[*bearer_id].maddr;
986 		node_lost_contact(n, &le->inputq);
987 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
988 		return;
989 	}
990 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
991 
992 	/* There is still a working link => initiate failover */
993 	*bearer_id = n->active_links[0];
994 	tnl = n->links[*bearer_id].link;
995 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
996 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
997 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
998 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
999 	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link down -> failover!");
1000 	tipc_link_reset(l);
1001 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
1002 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1003 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
1004 	*maddr = &n->links[*bearer_id].maddr;
1005 }
1006 
1007 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
1008 {
1009 	struct tipc_link_entry *le = &n->links[bearer_id];
1010 	struct tipc_media_addr *maddr = NULL;
1011 	struct tipc_link *l = le->link;
1012 	int old_bearer_id = bearer_id;
1013 	struct sk_buff_head xmitq;
1014 
1015 	if (!l)
1016 		return;
1017 
1018 	__skb_queue_head_init(&xmitq);
1019 
1020 	tipc_node_write_lock(n);
1021 	if (!tipc_link_is_establishing(l)) {
1022 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
1023 	} else {
1024 		/* Defuse pending tipc_node_link_up() */
1025 		tipc_link_reset(l);
1026 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1027 	}
1028 	if (delete) {
1029 		kfree(l);
1030 		le->link = NULL;
1031 		n->link_cnt--;
1032 	}
1033 	trace_tipc_node_link_down(n, true, "node link down or deleted!");
1034 	tipc_node_write_unlock(n);
1035 	if (delete)
1036 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
1037 	if (!skb_queue_empty(&xmitq))
1038 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr, n);
1039 	tipc_sk_rcv(n->net, &le->inputq);
1040 }
1041 
1042 static bool node_is_up(struct tipc_node *n)
1043 {
1044 	return n->active_links[0] != INVALID_BEARER_ID;
1045 }
1046 
1047 bool tipc_node_is_up(struct net *net, u32 addr)
1048 {
1049 	struct tipc_node *n;
1050 	bool retval = false;
1051 
1052 	if (in_own_node(net, addr))
1053 		return true;
1054 
1055 	n = tipc_node_find(net, addr);
1056 	if (!n)
1057 		return false;
1058 	retval = node_is_up(n);
1059 	tipc_node_put(n);
1060 	return retval;
1061 }
1062 
1063 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
1064 {
1065 	struct tipc_node *n;
1066 
1067 	addr ^= tipc_net(net)->random;
1068 	while ((n = tipc_node_find(net, addr))) {
1069 		tipc_node_put(n);
1070 		addr++;
1071 	}
1072 	return addr;
1073 }
1074 
1075 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
1076  * Returns suggested address if any, otherwise 0
1077  */
1078 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
1079 {
1080 	struct tipc_net *tn = tipc_net(net);
1081 	struct tipc_node *n;
1082 	bool preliminary;
1083 	u32 sugg_addr;
1084 
1085 	/* Suggest new address if some other peer is using this one */
1086 	n = tipc_node_find(net, addr);
1087 	if (n) {
1088 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
1089 			addr = 0;
1090 		tipc_node_put(n);
1091 		if (!addr)
1092 			return 0;
1093 		return tipc_node_suggest_addr(net, addr);
1094 	}
1095 
1096 	/* Suggest previously used address if peer is known */
1097 	n = tipc_node_find_by_id(net, id);
1098 	if (n) {
1099 		sugg_addr = n->addr;
1100 		preliminary = n->preliminary;
1101 		tipc_node_put(n);
1102 		if (!preliminary)
1103 			return sugg_addr;
1104 	}
1105 
1106 	/* Even this node may be in conflict */
1107 	if (tn->trial_addr == addr)
1108 		return tipc_node_suggest_addr(net, addr);
1109 
1110 	return 0;
1111 }
1112 
1113 void tipc_node_check_dest(struct net *net, u32 addr,
1114 			  u8 *peer_id, struct tipc_bearer *b,
1115 			  u16 capabilities, u32 signature, u32 hash_mixes,
1116 			  struct tipc_media_addr *maddr,
1117 			  bool *respond, bool *dupl_addr)
1118 {
1119 	struct tipc_node *n;
1120 	struct tipc_link *l, *snd_l;
1121 	struct tipc_link_entry *le;
1122 	bool addr_match = false;
1123 	bool sign_match = false;
1124 	bool link_up = false;
1125 	bool accept_addr = false;
1126 	bool reset = true;
1127 	char *if_name;
1128 	unsigned long intv;
1129 	u16 session;
1130 
1131 	*dupl_addr = false;
1132 	*respond = false;
1133 
1134 	n = tipc_node_create(net, addr, peer_id, capabilities, hash_mixes,
1135 			     false);
1136 	if (!n)
1137 		return;
1138 
1139 	tipc_node_write_lock(n);
1140 	if (unlikely(!n->bc_entry.link)) {
1141 		snd_l = tipc_bc_sndlink(net);
1142 		if (!tipc_link_bc_create(net, tipc_own_addr(net),
1143 					 addr, peer_id, U16_MAX,
1144 					 tipc_link_min_win(snd_l),
1145 					 tipc_link_max_win(snd_l),
1146 					 n->capabilities,
1147 					 &n->bc_entry.inputq1,
1148 					 &n->bc_entry.namedq, snd_l,
1149 					 &n->bc_entry.link)) {
1150 			pr_warn("Broadcast rcv link creation failed, no mem\n");
1151 			tipc_node_write_unlock_fast(n);
1152 			tipc_node_put(n);
1153 			return;
1154 		}
1155 	}
1156 
1157 	le = &n->links[b->identity];
1158 
1159 	/* Prepare to validate requesting node's signature and media address */
1160 	l = le->link;
1161 	link_up = l && tipc_link_is_up(l);
1162 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1163 	sign_match = (signature == n->signature);
1164 
1165 	/* These three flags give us eight permutations: */
1166 
1167 	if (sign_match && addr_match && link_up) {
1168 		/* All is fine. Do nothing. */
1169 		reset = false;
1170 		/* Peer node is not a container/local namespace */
1171 		if (!n->peer_hash_mix)
1172 			n->peer_hash_mix = hash_mixes;
1173 	} else if (sign_match && addr_match && !link_up) {
1174 		/* Respond. The link will come up in due time */
1175 		*respond = true;
1176 	} else if (sign_match && !addr_match && link_up) {
1177 		/* Peer has changed i/f address without rebooting.
1178 		 * If so, the link will reset soon, and the next
1179 		 * discovery will be accepted. So we can ignore it.
1180 		 * It may also be an cloned or malicious peer having
1181 		 * chosen the same node address and signature as an
1182 		 * existing one.
1183 		 * Ignore requests until the link goes down, if ever.
1184 		 */
1185 		*dupl_addr = true;
1186 	} else if (sign_match && !addr_match && !link_up) {
1187 		/* Peer link has changed i/f address without rebooting.
1188 		 * It may also be a cloned or malicious peer; we can't
1189 		 * distinguish between the two.
1190 		 * The signature is correct, so we must accept.
1191 		 */
1192 		accept_addr = true;
1193 		*respond = true;
1194 	} else if (!sign_match && addr_match && link_up) {
1195 		/* Peer node rebooted. Two possibilities:
1196 		 *  - Delayed re-discovery; this link endpoint has already
1197 		 *    reset and re-established contact with the peer, before
1198 		 *    receiving a discovery message from that node.
1199 		 *    (The peer happened to receive one from this node first).
1200 		 *  - The peer came back so fast that our side has not
1201 		 *    discovered it yet. Probing from this side will soon
1202 		 *    reset the link, since there can be no working link
1203 		 *    endpoint at the peer end, and the link will re-establish.
1204 		 *  Accept the signature, since it comes from a known peer.
1205 		 */
1206 		n->signature = signature;
1207 	} else if (!sign_match && addr_match && !link_up) {
1208 		/*  The peer node has rebooted.
1209 		 *  Accept signature, since it is a known peer.
1210 		 */
1211 		n->signature = signature;
1212 		*respond = true;
1213 	} else if (!sign_match && !addr_match && link_up) {
1214 		/* Peer rebooted with new address, or a new/duplicate peer.
1215 		 * Ignore until the link goes down, if ever.
1216 		 */
1217 		*dupl_addr = true;
1218 	} else if (!sign_match && !addr_match && !link_up) {
1219 		/* Peer rebooted with new address, or it is a new peer.
1220 		 * Accept signature and address.
1221 		 */
1222 		n->signature = signature;
1223 		accept_addr = true;
1224 		*respond = true;
1225 	}
1226 
1227 	if (!accept_addr)
1228 		goto exit;
1229 
1230 	/* Now create new link if not already existing */
1231 	if (!l) {
1232 		if (n->link_cnt == 2)
1233 			goto exit;
1234 
1235 		if_name = strchr(b->name, ':') + 1;
1236 		get_random_bytes(&session, sizeof(u16));
1237 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1238 				      b->net_plane, b->mtu, b->priority,
1239 				      b->min_win, b->max_win, session,
1240 				      tipc_own_addr(net), addr, peer_id,
1241 				      n->capabilities,
1242 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1243 				      &le->inputq,
1244 				      &n->bc_entry.namedq, &l)) {
1245 			*respond = false;
1246 			goto exit;
1247 		}
1248 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1249 		tipc_link_reset(l);
1250 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1251 		if (n->state == NODE_FAILINGOVER)
1252 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1253 		le->link = l;
1254 		n->link_cnt++;
1255 		tipc_node_calculate_timer(n, l);
1256 		if (n->link_cnt == 1) {
1257 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1258 			if (!mod_timer(&n->timer, intv))
1259 				tipc_node_get(n);
1260 		}
1261 	}
1262 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1263 exit:
1264 	tipc_node_write_unlock(n);
1265 	if (reset && l && !tipc_link_is_reset(l))
1266 		tipc_node_link_down(n, b->identity, false);
1267 	tipc_node_put(n);
1268 }
1269 
1270 void tipc_node_delete_links(struct net *net, int bearer_id)
1271 {
1272 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1273 	struct tipc_node *n;
1274 
1275 	rcu_read_lock();
1276 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1277 		tipc_node_link_down(n, bearer_id, true);
1278 	}
1279 	rcu_read_unlock();
1280 }
1281 
1282 static void tipc_node_reset_links(struct tipc_node *n)
1283 {
1284 	int i;
1285 
1286 	pr_warn("Resetting all links to %x\n", n->addr);
1287 
1288 	trace_tipc_node_reset_links(n, true, " ");
1289 	for (i = 0; i < MAX_BEARERS; i++) {
1290 		tipc_node_link_down(n, i, false);
1291 	}
1292 }
1293 
1294 /* tipc_node_fsm_evt - node finite state machine
1295  * Determines when contact is allowed with peer node
1296  */
1297 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1298 {
1299 	int state = n->state;
1300 
1301 	switch (state) {
1302 	case SELF_DOWN_PEER_DOWN:
1303 		switch (evt) {
1304 		case SELF_ESTABL_CONTACT_EVT:
1305 			state = SELF_UP_PEER_COMING;
1306 			break;
1307 		case PEER_ESTABL_CONTACT_EVT:
1308 			state = SELF_COMING_PEER_UP;
1309 			break;
1310 		case SELF_LOST_CONTACT_EVT:
1311 		case PEER_LOST_CONTACT_EVT:
1312 			break;
1313 		case NODE_SYNCH_END_EVT:
1314 		case NODE_SYNCH_BEGIN_EVT:
1315 		case NODE_FAILOVER_BEGIN_EVT:
1316 		case NODE_FAILOVER_END_EVT:
1317 		default:
1318 			goto illegal_evt;
1319 		}
1320 		break;
1321 	case SELF_UP_PEER_UP:
1322 		switch (evt) {
1323 		case SELF_LOST_CONTACT_EVT:
1324 			state = SELF_DOWN_PEER_LEAVING;
1325 			break;
1326 		case PEER_LOST_CONTACT_EVT:
1327 			state = SELF_LEAVING_PEER_DOWN;
1328 			break;
1329 		case NODE_SYNCH_BEGIN_EVT:
1330 			state = NODE_SYNCHING;
1331 			break;
1332 		case NODE_FAILOVER_BEGIN_EVT:
1333 			state = NODE_FAILINGOVER;
1334 			break;
1335 		case SELF_ESTABL_CONTACT_EVT:
1336 		case PEER_ESTABL_CONTACT_EVT:
1337 		case NODE_SYNCH_END_EVT:
1338 		case NODE_FAILOVER_END_EVT:
1339 			break;
1340 		default:
1341 			goto illegal_evt;
1342 		}
1343 		break;
1344 	case SELF_DOWN_PEER_LEAVING:
1345 		switch (evt) {
1346 		case PEER_LOST_CONTACT_EVT:
1347 			state = SELF_DOWN_PEER_DOWN;
1348 			break;
1349 		case SELF_ESTABL_CONTACT_EVT:
1350 		case PEER_ESTABL_CONTACT_EVT:
1351 		case SELF_LOST_CONTACT_EVT:
1352 			break;
1353 		case NODE_SYNCH_END_EVT:
1354 		case NODE_SYNCH_BEGIN_EVT:
1355 		case NODE_FAILOVER_BEGIN_EVT:
1356 		case NODE_FAILOVER_END_EVT:
1357 		default:
1358 			goto illegal_evt;
1359 		}
1360 		break;
1361 	case SELF_UP_PEER_COMING:
1362 		switch (evt) {
1363 		case PEER_ESTABL_CONTACT_EVT:
1364 			state = SELF_UP_PEER_UP;
1365 			break;
1366 		case SELF_LOST_CONTACT_EVT:
1367 			state = SELF_DOWN_PEER_DOWN;
1368 			break;
1369 		case SELF_ESTABL_CONTACT_EVT:
1370 		case PEER_LOST_CONTACT_EVT:
1371 		case NODE_SYNCH_END_EVT:
1372 		case NODE_FAILOVER_BEGIN_EVT:
1373 			break;
1374 		case NODE_SYNCH_BEGIN_EVT:
1375 		case NODE_FAILOVER_END_EVT:
1376 		default:
1377 			goto illegal_evt;
1378 		}
1379 		break;
1380 	case SELF_COMING_PEER_UP:
1381 		switch (evt) {
1382 		case SELF_ESTABL_CONTACT_EVT:
1383 			state = SELF_UP_PEER_UP;
1384 			break;
1385 		case PEER_LOST_CONTACT_EVT:
1386 			state = SELF_DOWN_PEER_DOWN;
1387 			break;
1388 		case SELF_LOST_CONTACT_EVT:
1389 		case PEER_ESTABL_CONTACT_EVT:
1390 			break;
1391 		case NODE_SYNCH_END_EVT:
1392 		case NODE_SYNCH_BEGIN_EVT:
1393 		case NODE_FAILOVER_BEGIN_EVT:
1394 		case NODE_FAILOVER_END_EVT:
1395 		default:
1396 			goto illegal_evt;
1397 		}
1398 		break;
1399 	case SELF_LEAVING_PEER_DOWN:
1400 		switch (evt) {
1401 		case SELF_LOST_CONTACT_EVT:
1402 			state = SELF_DOWN_PEER_DOWN;
1403 			break;
1404 		case SELF_ESTABL_CONTACT_EVT:
1405 		case PEER_ESTABL_CONTACT_EVT:
1406 		case PEER_LOST_CONTACT_EVT:
1407 			break;
1408 		case NODE_SYNCH_END_EVT:
1409 		case NODE_SYNCH_BEGIN_EVT:
1410 		case NODE_FAILOVER_BEGIN_EVT:
1411 		case NODE_FAILOVER_END_EVT:
1412 		default:
1413 			goto illegal_evt;
1414 		}
1415 		break;
1416 	case NODE_FAILINGOVER:
1417 		switch (evt) {
1418 		case SELF_LOST_CONTACT_EVT:
1419 			state = SELF_DOWN_PEER_LEAVING;
1420 			break;
1421 		case PEER_LOST_CONTACT_EVT:
1422 			state = SELF_LEAVING_PEER_DOWN;
1423 			break;
1424 		case NODE_FAILOVER_END_EVT:
1425 			state = SELF_UP_PEER_UP;
1426 			break;
1427 		case NODE_FAILOVER_BEGIN_EVT:
1428 		case SELF_ESTABL_CONTACT_EVT:
1429 		case PEER_ESTABL_CONTACT_EVT:
1430 			break;
1431 		case NODE_SYNCH_BEGIN_EVT:
1432 		case NODE_SYNCH_END_EVT:
1433 		default:
1434 			goto illegal_evt;
1435 		}
1436 		break;
1437 	case NODE_SYNCHING:
1438 		switch (evt) {
1439 		case SELF_LOST_CONTACT_EVT:
1440 			state = SELF_DOWN_PEER_LEAVING;
1441 			break;
1442 		case PEER_LOST_CONTACT_EVT:
1443 			state = SELF_LEAVING_PEER_DOWN;
1444 			break;
1445 		case NODE_SYNCH_END_EVT:
1446 			state = SELF_UP_PEER_UP;
1447 			break;
1448 		case NODE_FAILOVER_BEGIN_EVT:
1449 			state = NODE_FAILINGOVER;
1450 			break;
1451 		case NODE_SYNCH_BEGIN_EVT:
1452 		case SELF_ESTABL_CONTACT_EVT:
1453 		case PEER_ESTABL_CONTACT_EVT:
1454 			break;
1455 		case NODE_FAILOVER_END_EVT:
1456 		default:
1457 			goto illegal_evt;
1458 		}
1459 		break;
1460 	default:
1461 		pr_err("Unknown node fsm state %x\n", state);
1462 		break;
1463 	}
1464 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1465 	n->state = state;
1466 	return;
1467 
1468 illegal_evt:
1469 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1470 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1471 }
1472 
1473 static void node_lost_contact(struct tipc_node *n,
1474 			      struct sk_buff_head *inputq)
1475 {
1476 	struct tipc_sock_conn *conn, *safe;
1477 	struct tipc_link *l;
1478 	struct list_head *conns = &n->conn_sks;
1479 	struct sk_buff *skb;
1480 	uint i;
1481 
1482 	pr_debug("Lost contact with %x\n", n->addr);
1483 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1484 	trace_tipc_node_lost_contact(n, true, " ");
1485 
1486 	/* Clean up broadcast state */
1487 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1488 	__skb_queue_purge(&n->bc_entry.namedq);
1489 
1490 	/* Abort any ongoing link failover */
1491 	for (i = 0; i < MAX_BEARERS; i++) {
1492 		l = n->links[i].link;
1493 		if (l)
1494 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1495 	}
1496 
1497 	/* Notify publications from this node */
1498 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1499 	n->peer_net = NULL;
1500 	n->peer_hash_mix = 0;
1501 	/* Notify sockets connected to node */
1502 	list_for_each_entry_safe(conn, safe, conns, list) {
1503 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1504 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1505 				      conn->peer_node, conn->port,
1506 				      conn->peer_port, TIPC_ERR_NO_NODE);
1507 		if (likely(skb))
1508 			skb_queue_tail(inputq, skb);
1509 		list_del(&conn->list);
1510 		kfree(conn);
1511 	}
1512 }
1513 
1514 /**
1515  * tipc_node_get_linkname - get the name of a link
1516  *
1517  * @bearer_id: id of the bearer
1518  * @addr: peer node address
1519  * @linkname: link name output buffer
1520  *
1521  * Returns 0 on success
1522  */
1523 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1524 			   char *linkname, size_t len)
1525 {
1526 	struct tipc_link *link;
1527 	int err = -EINVAL;
1528 	struct tipc_node *node = tipc_node_find(net, addr);
1529 
1530 	if (!node)
1531 		return err;
1532 
1533 	if (bearer_id >= MAX_BEARERS)
1534 		goto exit;
1535 
1536 	tipc_node_read_lock(node);
1537 	link = node->links[bearer_id].link;
1538 	if (link) {
1539 		strncpy(linkname, tipc_link_name(link), len);
1540 		err = 0;
1541 	}
1542 	tipc_node_read_unlock(node);
1543 exit:
1544 	tipc_node_put(node);
1545 	return err;
1546 }
1547 
1548 /* Caller should hold node lock for the passed node */
1549 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1550 {
1551 	void *hdr;
1552 	struct nlattr *attrs;
1553 
1554 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1555 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1556 	if (!hdr)
1557 		return -EMSGSIZE;
1558 
1559 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1560 	if (!attrs)
1561 		goto msg_full;
1562 
1563 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1564 		goto attr_msg_full;
1565 	if (node_is_up(node))
1566 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1567 			goto attr_msg_full;
1568 
1569 	nla_nest_end(msg->skb, attrs);
1570 	genlmsg_end(msg->skb, hdr);
1571 
1572 	return 0;
1573 
1574 attr_msg_full:
1575 	nla_nest_cancel(msg->skb, attrs);
1576 msg_full:
1577 	genlmsg_cancel(msg->skb, hdr);
1578 
1579 	return -EMSGSIZE;
1580 }
1581 
1582 static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)
1583 {
1584 	struct tipc_msg *hdr = buf_msg(skb_peek(list));
1585 	struct sk_buff_head inputq;
1586 
1587 	switch (msg_user(hdr)) {
1588 	case TIPC_LOW_IMPORTANCE:
1589 	case TIPC_MEDIUM_IMPORTANCE:
1590 	case TIPC_HIGH_IMPORTANCE:
1591 	case TIPC_CRITICAL_IMPORTANCE:
1592 		if (msg_connected(hdr) || msg_named(hdr) ||
1593 		    msg_direct(hdr)) {
1594 			tipc_loopback_trace(peer_net, list);
1595 			spin_lock_init(&list->lock);
1596 			tipc_sk_rcv(peer_net, list);
1597 			return;
1598 		}
1599 		if (msg_mcast(hdr)) {
1600 			tipc_loopback_trace(peer_net, list);
1601 			skb_queue_head_init(&inputq);
1602 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1603 			__skb_queue_purge(list);
1604 			skb_queue_purge(&inputq);
1605 			return;
1606 		}
1607 		return;
1608 	case MSG_FRAGMENTER:
1609 		if (tipc_msg_assemble(list)) {
1610 			tipc_loopback_trace(peer_net, list);
1611 			skb_queue_head_init(&inputq);
1612 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1613 			__skb_queue_purge(list);
1614 			skb_queue_purge(&inputq);
1615 		}
1616 		return;
1617 	case GROUP_PROTOCOL:
1618 	case CONN_MANAGER:
1619 		tipc_loopback_trace(peer_net, list);
1620 		spin_lock_init(&list->lock);
1621 		tipc_sk_rcv(peer_net, list);
1622 		return;
1623 	case LINK_PROTOCOL:
1624 	case NAME_DISTRIBUTOR:
1625 	case TUNNEL_PROTOCOL:
1626 	case BCAST_PROTOCOL:
1627 		return;
1628 	default:
1629 		return;
1630 	};
1631 }
1632 
1633 /**
1634  * tipc_node_xmit() is the general link level function for message sending
1635  * @net: the applicable net namespace
1636  * @list: chain of buffers containing message
1637  * @dnode: address of destination node
1638  * @selector: a number used for deterministic link selection
1639  * Consumes the buffer chain.
1640  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1641  */
1642 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1643 		   u32 dnode, int selector)
1644 {
1645 	struct tipc_link_entry *le = NULL;
1646 	struct tipc_node *n;
1647 	struct sk_buff_head xmitq;
1648 	bool node_up = false;
1649 	int bearer_id;
1650 	int rc;
1651 
1652 	if (in_own_node(net, dnode)) {
1653 		tipc_loopback_trace(net, list);
1654 		spin_lock_init(&list->lock);
1655 		tipc_sk_rcv(net, list);
1656 		return 0;
1657 	}
1658 
1659 	n = tipc_node_find(net, dnode);
1660 	if (unlikely(!n)) {
1661 		__skb_queue_purge(list);
1662 		return -EHOSTUNREACH;
1663 	}
1664 
1665 	tipc_node_read_lock(n);
1666 	node_up = node_is_up(n);
1667 	if (node_up && n->peer_net && check_net(n->peer_net)) {
1668 		/* xmit inner linux container */
1669 		tipc_lxc_xmit(n->peer_net, list);
1670 		if (likely(skb_queue_empty(list))) {
1671 			tipc_node_read_unlock(n);
1672 			tipc_node_put(n);
1673 			return 0;
1674 		}
1675 	}
1676 
1677 	bearer_id = n->active_links[selector & 1];
1678 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1679 		tipc_node_read_unlock(n);
1680 		tipc_node_put(n);
1681 		__skb_queue_purge(list);
1682 		return -EHOSTUNREACH;
1683 	}
1684 
1685 	__skb_queue_head_init(&xmitq);
1686 	le = &n->links[bearer_id];
1687 	spin_lock_bh(&le->lock);
1688 	rc = tipc_link_xmit(le->link, list, &xmitq);
1689 	spin_unlock_bh(&le->lock);
1690 	tipc_node_read_unlock(n);
1691 
1692 	if (unlikely(rc == -ENOBUFS))
1693 		tipc_node_link_down(n, bearer_id, false);
1694 	else
1695 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1696 
1697 	tipc_node_put(n);
1698 
1699 	return rc;
1700 }
1701 
1702 /* tipc_node_xmit_skb(): send single buffer to destination
1703  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1704  * messages, which will not be rejected
1705  * The only exception is datagram messages rerouted after secondary
1706  * lookup, which are rare and safe to dispose of anyway.
1707  */
1708 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1709 		       u32 selector)
1710 {
1711 	struct sk_buff_head head;
1712 
1713 	__skb_queue_head_init(&head);
1714 	__skb_queue_tail(&head, skb);
1715 	tipc_node_xmit(net, &head, dnode, selector);
1716 	return 0;
1717 }
1718 
1719 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1720  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1721  */
1722 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1723 {
1724 	struct sk_buff *skb;
1725 	u32 selector, dnode;
1726 
1727 	while ((skb = __skb_dequeue(xmitq))) {
1728 		selector = msg_origport(buf_msg(skb));
1729 		dnode = msg_destnode(buf_msg(skb));
1730 		tipc_node_xmit_skb(net, skb, dnode, selector);
1731 	}
1732 	return 0;
1733 }
1734 
1735 void tipc_node_broadcast(struct net *net, struct sk_buff *skb, int rc_dests)
1736 {
1737 	struct sk_buff_head xmitq;
1738 	struct sk_buff *txskb;
1739 	struct tipc_node *n;
1740 	u16 dummy;
1741 	u32 dst;
1742 
1743 	/* Use broadcast if all nodes support it */
1744 	if (!rc_dests && tipc_bcast_get_mode(net) != BCLINK_MODE_RCAST) {
1745 		__skb_queue_head_init(&xmitq);
1746 		__skb_queue_tail(&xmitq, skb);
1747 		tipc_bcast_xmit(net, &xmitq, &dummy);
1748 		return;
1749 	}
1750 
1751 	/* Otherwise use legacy replicast method */
1752 	rcu_read_lock();
1753 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1754 		dst = n->addr;
1755 		if (in_own_node(net, dst))
1756 			continue;
1757 		if (!node_is_up(n))
1758 			continue;
1759 		txskb = pskb_copy(skb, GFP_ATOMIC);
1760 		if (!txskb)
1761 			break;
1762 		msg_set_destnode(buf_msg(txskb), dst);
1763 		tipc_node_xmit_skb(net, txskb, dst, 0);
1764 	}
1765 	rcu_read_unlock();
1766 	kfree_skb(skb);
1767 }
1768 
1769 static void tipc_node_mcast_rcv(struct tipc_node *n)
1770 {
1771 	struct tipc_bclink_entry *be = &n->bc_entry;
1772 
1773 	/* 'arrvq' is under inputq2's lock protection */
1774 	spin_lock_bh(&be->inputq2.lock);
1775 	spin_lock_bh(&be->inputq1.lock);
1776 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1777 	spin_unlock_bh(&be->inputq1.lock);
1778 	spin_unlock_bh(&be->inputq2.lock);
1779 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1780 }
1781 
1782 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1783 				  int bearer_id, struct sk_buff_head *xmitq)
1784 {
1785 	struct tipc_link *ucl;
1786 	int rc;
1787 
1788 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr, xmitq);
1789 
1790 	if (rc & TIPC_LINK_DOWN_EVT) {
1791 		tipc_node_reset_links(n);
1792 		return;
1793 	}
1794 
1795 	if (!(rc & TIPC_LINK_SND_STATE))
1796 		return;
1797 
1798 	/* If probe message, a STATE response will be sent anyway */
1799 	if (msg_probe(hdr))
1800 		return;
1801 
1802 	/* Produce a STATE message carrying broadcast NACK */
1803 	tipc_node_read_lock(n);
1804 	ucl = n->links[bearer_id].link;
1805 	if (ucl)
1806 		tipc_link_build_state_msg(ucl, xmitq);
1807 	tipc_node_read_unlock(n);
1808 }
1809 
1810 /**
1811  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1812  * @net: the applicable net namespace
1813  * @skb: TIPC packet
1814  * @bearer_id: id of bearer message arrived on
1815  *
1816  * Invoked with no locks held.
1817  */
1818 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1819 {
1820 	int rc;
1821 	struct sk_buff_head xmitq;
1822 	struct tipc_bclink_entry *be;
1823 	struct tipc_link_entry *le;
1824 	struct tipc_msg *hdr = buf_msg(skb);
1825 	int usr = msg_user(hdr);
1826 	u32 dnode = msg_destnode(hdr);
1827 	struct tipc_node *n;
1828 
1829 	__skb_queue_head_init(&xmitq);
1830 
1831 	/* If NACK for other node, let rcv link for that node peek into it */
1832 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1833 		n = tipc_node_find(net, dnode);
1834 	else
1835 		n = tipc_node_find(net, msg_prevnode(hdr));
1836 	if (!n) {
1837 		kfree_skb(skb);
1838 		return;
1839 	}
1840 	be = &n->bc_entry;
1841 	le = &n->links[bearer_id];
1842 
1843 	rc = tipc_bcast_rcv(net, be->link, skb);
1844 
1845 	/* Broadcast ACKs are sent on a unicast link */
1846 	if (rc & TIPC_LINK_SND_STATE) {
1847 		tipc_node_read_lock(n);
1848 		tipc_link_build_state_msg(le->link, &xmitq);
1849 		tipc_node_read_unlock(n);
1850 	}
1851 
1852 	if (!skb_queue_empty(&xmitq))
1853 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1854 
1855 	if (!skb_queue_empty(&be->inputq1))
1856 		tipc_node_mcast_rcv(n);
1857 
1858 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1859 	if (!skb_queue_empty(&n->bc_entry.namedq))
1860 		tipc_named_rcv(net, &n->bc_entry.namedq,
1861 			       &n->bc_entry.named_rcv_nxt,
1862 			       &n->bc_entry.named_open);
1863 
1864 	/* If reassembly or retransmission failure => reset all links to peer */
1865 	if (rc & TIPC_LINK_DOWN_EVT)
1866 		tipc_node_reset_links(n);
1867 
1868 	tipc_node_put(n);
1869 }
1870 
1871 /**
1872  * tipc_node_check_state - check and if necessary update node state
1873  * @skb: TIPC packet
1874  * @bearer_id: identity of bearer delivering the packet
1875  * Returns true if state and msg are ok, otherwise false
1876  */
1877 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1878 				  int bearer_id, struct sk_buff_head *xmitq)
1879 {
1880 	struct tipc_msg *hdr = buf_msg(skb);
1881 	int usr = msg_user(hdr);
1882 	int mtyp = msg_type(hdr);
1883 	u16 oseqno = msg_seqno(hdr);
1884 	u16 exp_pkts = msg_msgcnt(hdr);
1885 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1886 	int state = n->state;
1887 	struct tipc_link *l, *tnl, *pl = NULL;
1888 	struct tipc_media_addr *maddr;
1889 	int pb_id;
1890 
1891 	if (trace_tipc_node_check_state_enabled()) {
1892 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1893 		trace_tipc_node_check_state(n, true, " ");
1894 	}
1895 	l = n->links[bearer_id].link;
1896 	if (!l)
1897 		return false;
1898 	rcv_nxt = tipc_link_rcv_nxt(l);
1899 
1900 
1901 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1902 		return true;
1903 
1904 	/* Find parallel link, if any */
1905 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1906 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1907 			pl = n->links[pb_id].link;
1908 			break;
1909 		}
1910 	}
1911 
1912 	if (!tipc_link_validate_msg(l, hdr)) {
1913 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1914 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1915 		return false;
1916 	}
1917 
1918 	/* Check and update node accesibility if applicable */
1919 	if (state == SELF_UP_PEER_COMING) {
1920 		if (!tipc_link_is_up(l))
1921 			return true;
1922 		if (!msg_peer_link_is_up(hdr))
1923 			return true;
1924 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1925 	}
1926 
1927 	if (state == SELF_DOWN_PEER_LEAVING) {
1928 		if (msg_peer_node_is_up(hdr))
1929 			return false;
1930 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1931 		return true;
1932 	}
1933 
1934 	if (state == SELF_LEAVING_PEER_DOWN)
1935 		return false;
1936 
1937 	/* Ignore duplicate packets */
1938 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1939 		return true;
1940 
1941 	/* Initiate or update failover mode if applicable */
1942 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1943 		syncpt = oseqno + exp_pkts - 1;
1944 		if (pl && !tipc_link_is_reset(pl)) {
1945 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1946 			trace_tipc_node_link_down(n, true,
1947 						  "node link down <- failover!");
1948 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1949 							tipc_link_inputq(l));
1950 		}
1951 
1952 		/* If parallel link was already down, and this happened before
1953 		 * the tunnel link came up, node failover was never started.
1954 		 * Ensure that a FAILOVER_MSG is sent to get peer out of
1955 		 * NODE_FAILINGOVER state, also this node must accept
1956 		 * TUNNEL_MSGs from peer.
1957 		 */
1958 		if (n->state != NODE_FAILINGOVER)
1959 			tipc_node_link_failover(n, pl, l, xmitq);
1960 
1961 		/* If pkts arrive out of order, use lowest calculated syncpt */
1962 		if (less(syncpt, n->sync_point))
1963 			n->sync_point = syncpt;
1964 	}
1965 
1966 	/* Open parallel link when tunnel link reaches synch point */
1967 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1968 		if (!more(rcv_nxt, n->sync_point))
1969 			return true;
1970 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1971 		if (pl)
1972 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1973 		return true;
1974 	}
1975 
1976 	/* No synching needed if only one link */
1977 	if (!pl || !tipc_link_is_up(pl))
1978 		return true;
1979 
1980 	/* Initiate synch mode if applicable */
1981 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1982 		if (n->capabilities & TIPC_TUNNEL_ENHANCED)
1983 			syncpt = msg_syncpt(hdr);
1984 		else
1985 			syncpt = msg_seqno(msg_inner_hdr(hdr)) + exp_pkts - 1;
1986 		if (!tipc_link_is_up(l))
1987 			__tipc_node_link_up(n, bearer_id, xmitq);
1988 		if (n->state == SELF_UP_PEER_UP) {
1989 			n->sync_point = syncpt;
1990 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1991 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1992 		}
1993 	}
1994 
1995 	/* Open tunnel link when parallel link reaches synch point */
1996 	if (n->state == NODE_SYNCHING) {
1997 		if (tipc_link_is_synching(l)) {
1998 			tnl = l;
1999 		} else {
2000 			tnl = pl;
2001 			pl = l;
2002 		}
2003 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
2004 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
2005 		if (more(dlv_nxt, n->sync_point)) {
2006 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
2007 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
2008 			return true;
2009 		}
2010 		if (l == pl)
2011 			return true;
2012 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
2013 			return true;
2014 		if (usr == LINK_PROTOCOL)
2015 			return true;
2016 		return false;
2017 	}
2018 	return true;
2019 }
2020 
2021 /**
2022  * tipc_rcv - process TIPC packets/messages arriving from off-node
2023  * @net: the applicable net namespace
2024  * @skb: TIPC packet
2025  * @b: pointer to bearer message arrived on
2026  *
2027  * Invoked with no locks held. Bearer pointer must point to a valid bearer
2028  * structure (i.e. cannot be NULL), but bearer can be inactive.
2029  */
2030 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
2031 {
2032 	struct sk_buff_head xmitq;
2033 	struct tipc_link_entry *le;
2034 	struct tipc_msg *hdr;
2035 	struct tipc_node *n;
2036 	int bearer_id = b->identity;
2037 	u32 self = tipc_own_addr(net);
2038 	int usr, rc = 0;
2039 	u16 bc_ack;
2040 #ifdef CONFIG_TIPC_CRYPTO
2041 	struct tipc_ehdr *ehdr;
2042 
2043 	/* Check if message must be decrypted first */
2044 	if (TIPC_SKB_CB(skb)->decrypted || !tipc_ehdr_validate(skb))
2045 		goto rcv;
2046 
2047 	ehdr = (struct tipc_ehdr *)skb->data;
2048 	if (likely(ehdr->user != LINK_CONFIG)) {
2049 		n = tipc_node_find(net, ntohl(ehdr->addr));
2050 		if (unlikely(!n))
2051 			goto discard;
2052 	} else {
2053 		n = tipc_node_find_by_id(net, ehdr->id);
2054 	}
2055 	tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
2056 	if (!skb)
2057 		return;
2058 
2059 rcv:
2060 #endif
2061 	/* Ensure message is well-formed before touching the header */
2062 	if (unlikely(!tipc_msg_validate(&skb)))
2063 		goto discard;
2064 	__skb_queue_head_init(&xmitq);
2065 	hdr = buf_msg(skb);
2066 	usr = msg_user(hdr);
2067 	bc_ack = msg_bcast_ack(hdr);
2068 
2069 	/* Handle arrival of discovery or broadcast packet */
2070 	if (unlikely(msg_non_seq(hdr))) {
2071 		if (unlikely(usr == LINK_CONFIG))
2072 			return tipc_disc_rcv(net, skb, b);
2073 		else
2074 			return tipc_node_bc_rcv(net, skb, bearer_id);
2075 	}
2076 
2077 	/* Discard unicast link messages destined for another node */
2078 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
2079 		goto discard;
2080 
2081 	/* Locate neighboring node that sent packet */
2082 	n = tipc_node_find(net, msg_prevnode(hdr));
2083 	if (unlikely(!n))
2084 		goto discard;
2085 	le = &n->links[bearer_id];
2086 
2087 	/* Ensure broadcast reception is in synch with peer's send state */
2088 	if (unlikely(usr == LINK_PROTOCOL)) {
2089 		if (unlikely(skb_linearize(skb))) {
2090 			tipc_node_put(n);
2091 			goto discard;
2092 		}
2093 		hdr = buf_msg(skb);
2094 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
2095 	} else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack)) {
2096 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
2097 	}
2098 
2099 	/* Receive packet directly if conditions permit */
2100 	tipc_node_read_lock(n);
2101 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
2102 		spin_lock_bh(&le->lock);
2103 		if (le->link) {
2104 			rc = tipc_link_rcv(le->link, skb, &xmitq);
2105 			skb = NULL;
2106 		}
2107 		spin_unlock_bh(&le->lock);
2108 	}
2109 	tipc_node_read_unlock(n);
2110 
2111 	/* Check/update node state before receiving */
2112 	if (unlikely(skb)) {
2113 		if (unlikely(skb_linearize(skb)))
2114 			goto out_node_put;
2115 		tipc_node_write_lock(n);
2116 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
2117 			if (le->link) {
2118 				rc = tipc_link_rcv(le->link, skb, &xmitq);
2119 				skb = NULL;
2120 			}
2121 		}
2122 		tipc_node_write_unlock(n);
2123 	}
2124 
2125 	if (unlikely(rc & TIPC_LINK_UP_EVT))
2126 		tipc_node_link_up(n, bearer_id, &xmitq);
2127 
2128 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
2129 		tipc_node_link_down(n, bearer_id, false);
2130 
2131 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
2132 		tipc_named_rcv(net, &n->bc_entry.namedq,
2133 			       &n->bc_entry.named_rcv_nxt,
2134 			       &n->bc_entry.named_open);
2135 
2136 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
2137 		tipc_node_mcast_rcv(n);
2138 
2139 	if (!skb_queue_empty(&le->inputq))
2140 		tipc_sk_rcv(net, &le->inputq);
2141 
2142 	if (!skb_queue_empty(&xmitq))
2143 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
2144 
2145 out_node_put:
2146 	tipc_node_put(n);
2147 discard:
2148 	kfree_skb(skb);
2149 }
2150 
2151 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
2152 			      int prop)
2153 {
2154 	struct tipc_net *tn = tipc_net(net);
2155 	int bearer_id = b->identity;
2156 	struct sk_buff_head xmitq;
2157 	struct tipc_link_entry *e;
2158 	struct tipc_node *n;
2159 
2160 	__skb_queue_head_init(&xmitq);
2161 
2162 	rcu_read_lock();
2163 
2164 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2165 		tipc_node_write_lock(n);
2166 		e = &n->links[bearer_id];
2167 		if (e->link) {
2168 			if (prop == TIPC_NLA_PROP_TOL)
2169 				tipc_link_set_tolerance(e->link, b->tolerance,
2170 							&xmitq);
2171 			else if (prop == TIPC_NLA_PROP_MTU)
2172 				tipc_link_set_mtu(e->link, b->mtu);
2173 		}
2174 		tipc_node_write_unlock(n);
2175 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
2176 	}
2177 
2178 	rcu_read_unlock();
2179 }
2180 
2181 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
2182 {
2183 	struct net *net = sock_net(skb->sk);
2184 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2185 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
2186 	struct tipc_node *peer, *temp_node;
2187 	u32 addr;
2188 	int err;
2189 
2190 	/* We identify the peer by its net */
2191 	if (!info->attrs[TIPC_NLA_NET])
2192 		return -EINVAL;
2193 
2194 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
2195 					  info->attrs[TIPC_NLA_NET],
2196 					  tipc_nl_net_policy, info->extack);
2197 	if (err)
2198 		return err;
2199 
2200 	if (!attrs[TIPC_NLA_NET_ADDR])
2201 		return -EINVAL;
2202 
2203 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
2204 
2205 	if (in_own_node(net, addr))
2206 		return -ENOTSUPP;
2207 
2208 	spin_lock_bh(&tn->node_list_lock);
2209 	peer = tipc_node_find(net, addr);
2210 	if (!peer) {
2211 		spin_unlock_bh(&tn->node_list_lock);
2212 		return -ENXIO;
2213 	}
2214 
2215 	tipc_node_write_lock(peer);
2216 	if (peer->state != SELF_DOWN_PEER_DOWN &&
2217 	    peer->state != SELF_DOWN_PEER_LEAVING) {
2218 		tipc_node_write_unlock(peer);
2219 		err = -EBUSY;
2220 		goto err_out;
2221 	}
2222 
2223 	tipc_node_clear_links(peer);
2224 	tipc_node_write_unlock(peer);
2225 	tipc_node_delete(peer);
2226 
2227 	/* Calculate cluster capabilities */
2228 	tn->capabilities = TIPC_NODE_CAPABILITIES;
2229 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
2230 		tn->capabilities &= temp_node->capabilities;
2231 	}
2232 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
2233 	err = 0;
2234 err_out:
2235 	tipc_node_put(peer);
2236 	spin_unlock_bh(&tn->node_list_lock);
2237 
2238 	return err;
2239 }
2240 
2241 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
2242 {
2243 	int err;
2244 	struct net *net = sock_net(skb->sk);
2245 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2246 	int done = cb->args[0];
2247 	int last_addr = cb->args[1];
2248 	struct tipc_node *node;
2249 	struct tipc_nl_msg msg;
2250 
2251 	if (done)
2252 		return 0;
2253 
2254 	msg.skb = skb;
2255 	msg.portid = NETLINK_CB(cb->skb).portid;
2256 	msg.seq = cb->nlh->nlmsg_seq;
2257 
2258 	rcu_read_lock();
2259 	if (last_addr) {
2260 		node = tipc_node_find(net, last_addr);
2261 		if (!node) {
2262 			rcu_read_unlock();
2263 			/* We never set seq or call nl_dump_check_consistent()
2264 			 * this means that setting prev_seq here will cause the
2265 			 * consistence check to fail in the netlink callback
2266 			 * handler. Resulting in the NLMSG_DONE message having
2267 			 * the NLM_F_DUMP_INTR flag set if the node state
2268 			 * changed while we released the lock.
2269 			 */
2270 			cb->prev_seq = 1;
2271 			return -EPIPE;
2272 		}
2273 		tipc_node_put(node);
2274 	}
2275 
2276 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2277 		if (node->preliminary)
2278 			continue;
2279 		if (last_addr) {
2280 			if (node->addr == last_addr)
2281 				last_addr = 0;
2282 			else
2283 				continue;
2284 		}
2285 
2286 		tipc_node_read_lock(node);
2287 		err = __tipc_nl_add_node(&msg, node);
2288 		if (err) {
2289 			last_addr = node->addr;
2290 			tipc_node_read_unlock(node);
2291 			goto out;
2292 		}
2293 
2294 		tipc_node_read_unlock(node);
2295 	}
2296 	done = 1;
2297 out:
2298 	cb->args[0] = done;
2299 	cb->args[1] = last_addr;
2300 	rcu_read_unlock();
2301 
2302 	return skb->len;
2303 }
2304 
2305 /* tipc_node_find_by_name - locate owner node of link by link's name
2306  * @net: the applicable net namespace
2307  * @name: pointer to link name string
2308  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2309  *
2310  * Returns pointer to node owning the link, or 0 if no matching link is found.
2311  */
2312 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2313 						const char *link_name,
2314 						unsigned int *bearer_id)
2315 {
2316 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2317 	struct tipc_link *l;
2318 	struct tipc_node *n;
2319 	struct tipc_node *found_node = NULL;
2320 	int i;
2321 
2322 	*bearer_id = 0;
2323 	rcu_read_lock();
2324 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2325 		tipc_node_read_lock(n);
2326 		for (i = 0; i < MAX_BEARERS; i++) {
2327 			l = n->links[i].link;
2328 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2329 				*bearer_id = i;
2330 				found_node = n;
2331 				break;
2332 			}
2333 		}
2334 		tipc_node_read_unlock(n);
2335 		if (found_node)
2336 			break;
2337 	}
2338 	rcu_read_unlock();
2339 
2340 	return found_node;
2341 }
2342 
2343 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2344 {
2345 	int err;
2346 	int res = 0;
2347 	int bearer_id;
2348 	char *name;
2349 	struct tipc_link *link;
2350 	struct tipc_node *node;
2351 	struct sk_buff_head xmitq;
2352 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2353 	struct net *net = sock_net(skb->sk);
2354 
2355 	__skb_queue_head_init(&xmitq);
2356 
2357 	if (!info->attrs[TIPC_NLA_LINK])
2358 		return -EINVAL;
2359 
2360 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2361 					  info->attrs[TIPC_NLA_LINK],
2362 					  tipc_nl_link_policy, info->extack);
2363 	if (err)
2364 		return err;
2365 
2366 	if (!attrs[TIPC_NLA_LINK_NAME])
2367 		return -EINVAL;
2368 
2369 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2370 
2371 	if (strcmp(name, tipc_bclink_name) == 0)
2372 		return tipc_nl_bc_link_set(net, attrs);
2373 
2374 	node = tipc_node_find_by_name(net, name, &bearer_id);
2375 	if (!node)
2376 		return -EINVAL;
2377 
2378 	tipc_node_read_lock(node);
2379 
2380 	link = node->links[bearer_id].link;
2381 	if (!link) {
2382 		res = -EINVAL;
2383 		goto out;
2384 	}
2385 
2386 	if (attrs[TIPC_NLA_LINK_PROP]) {
2387 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2388 
2389 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
2390 		if (err) {
2391 			res = err;
2392 			goto out;
2393 		}
2394 
2395 		if (props[TIPC_NLA_PROP_TOL]) {
2396 			u32 tol;
2397 
2398 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2399 			tipc_link_set_tolerance(link, tol, &xmitq);
2400 		}
2401 		if (props[TIPC_NLA_PROP_PRIO]) {
2402 			u32 prio;
2403 
2404 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2405 			tipc_link_set_prio(link, prio, &xmitq);
2406 		}
2407 		if (props[TIPC_NLA_PROP_WIN]) {
2408 			u32 max_win;
2409 
2410 			max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2411 			tipc_link_set_queue_limits(link,
2412 						   tipc_link_min_win(link),
2413 						   max_win);
2414 		}
2415 	}
2416 
2417 out:
2418 	tipc_node_read_unlock(node);
2419 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
2420 			 NULL);
2421 	return res;
2422 }
2423 
2424 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2425 {
2426 	struct net *net = genl_info_net(info);
2427 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2428 	struct tipc_nl_msg msg;
2429 	char *name;
2430 	int err;
2431 
2432 	msg.portid = info->snd_portid;
2433 	msg.seq = info->snd_seq;
2434 
2435 	if (!info->attrs[TIPC_NLA_LINK])
2436 		return -EINVAL;
2437 
2438 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2439 					  info->attrs[TIPC_NLA_LINK],
2440 					  tipc_nl_link_policy, info->extack);
2441 	if (err)
2442 		return err;
2443 
2444 	if (!attrs[TIPC_NLA_LINK_NAME])
2445 		return -EINVAL;
2446 
2447 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2448 
2449 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2450 	if (!msg.skb)
2451 		return -ENOMEM;
2452 
2453 	if (strcmp(name, tipc_bclink_name) == 0) {
2454 		err = tipc_nl_add_bc_link(net, &msg, tipc_net(net)->bcl);
2455 		if (err)
2456 			goto err_free;
2457 	} else {
2458 		int bearer_id;
2459 		struct tipc_node *node;
2460 		struct tipc_link *link;
2461 
2462 		node = tipc_node_find_by_name(net, name, &bearer_id);
2463 		if (!node) {
2464 			err = -EINVAL;
2465 			goto err_free;
2466 		}
2467 
2468 		tipc_node_read_lock(node);
2469 		link = node->links[bearer_id].link;
2470 		if (!link) {
2471 			tipc_node_read_unlock(node);
2472 			err = -EINVAL;
2473 			goto err_free;
2474 		}
2475 
2476 		err = __tipc_nl_add_link(net, &msg, link, 0);
2477 		tipc_node_read_unlock(node);
2478 		if (err)
2479 			goto err_free;
2480 	}
2481 
2482 	return genlmsg_reply(msg.skb, info);
2483 
2484 err_free:
2485 	nlmsg_free(msg.skb);
2486 	return err;
2487 }
2488 
2489 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2490 {
2491 	int err;
2492 	char *link_name;
2493 	unsigned int bearer_id;
2494 	struct tipc_link *link;
2495 	struct tipc_node *node;
2496 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2497 	struct net *net = sock_net(skb->sk);
2498 	struct tipc_net *tn = tipc_net(net);
2499 	struct tipc_link_entry *le;
2500 
2501 	if (!info->attrs[TIPC_NLA_LINK])
2502 		return -EINVAL;
2503 
2504 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2505 					  info->attrs[TIPC_NLA_LINK],
2506 					  tipc_nl_link_policy, info->extack);
2507 	if (err)
2508 		return err;
2509 
2510 	if (!attrs[TIPC_NLA_LINK_NAME])
2511 		return -EINVAL;
2512 
2513 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2514 
2515 	err = -EINVAL;
2516 	if (!strcmp(link_name, tipc_bclink_name)) {
2517 		err = tipc_bclink_reset_stats(net, tipc_bc_sndlink(net));
2518 		if (err)
2519 			return err;
2520 		return 0;
2521 	} else if (strstr(link_name, tipc_bclink_name)) {
2522 		rcu_read_lock();
2523 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2524 			tipc_node_read_lock(node);
2525 			link = node->bc_entry.link;
2526 			if (link && !strcmp(link_name, tipc_link_name(link))) {
2527 				err = tipc_bclink_reset_stats(net, link);
2528 				tipc_node_read_unlock(node);
2529 				break;
2530 			}
2531 			tipc_node_read_unlock(node);
2532 		}
2533 		rcu_read_unlock();
2534 		return err;
2535 	}
2536 
2537 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2538 	if (!node)
2539 		return -EINVAL;
2540 
2541 	le = &node->links[bearer_id];
2542 	tipc_node_read_lock(node);
2543 	spin_lock_bh(&le->lock);
2544 	link = node->links[bearer_id].link;
2545 	if (!link) {
2546 		spin_unlock_bh(&le->lock);
2547 		tipc_node_read_unlock(node);
2548 		return -EINVAL;
2549 	}
2550 	tipc_link_reset_stats(link);
2551 	spin_unlock_bh(&le->lock);
2552 	tipc_node_read_unlock(node);
2553 	return 0;
2554 }
2555 
2556 /* Caller should hold node lock  */
2557 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2558 				    struct tipc_node *node, u32 *prev_link,
2559 				    bool bc_link)
2560 {
2561 	u32 i;
2562 	int err;
2563 
2564 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2565 		*prev_link = i;
2566 
2567 		if (!node->links[i].link)
2568 			continue;
2569 
2570 		err = __tipc_nl_add_link(net, msg,
2571 					 node->links[i].link, NLM_F_MULTI);
2572 		if (err)
2573 			return err;
2574 	}
2575 
2576 	if (bc_link) {
2577 		*prev_link = i;
2578 		err = tipc_nl_add_bc_link(net, msg, node->bc_entry.link);
2579 		if (err)
2580 			return err;
2581 	}
2582 
2583 	*prev_link = 0;
2584 
2585 	return 0;
2586 }
2587 
2588 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2589 {
2590 	struct net *net = sock_net(skb->sk);
2591 	struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2592 	struct nlattr *link[TIPC_NLA_LINK_MAX + 1];
2593 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2594 	struct tipc_node *node;
2595 	struct tipc_nl_msg msg;
2596 	u32 prev_node = cb->args[0];
2597 	u32 prev_link = cb->args[1];
2598 	int done = cb->args[2];
2599 	bool bc_link = cb->args[3];
2600 	int err;
2601 
2602 	if (done)
2603 		return 0;
2604 
2605 	if (!prev_node) {
2606 		/* Check if broadcast-receiver links dumping is needed */
2607 		if (attrs && attrs[TIPC_NLA_LINK]) {
2608 			err = nla_parse_nested_deprecated(link,
2609 							  TIPC_NLA_LINK_MAX,
2610 							  attrs[TIPC_NLA_LINK],
2611 							  tipc_nl_link_policy,
2612 							  NULL);
2613 			if (unlikely(err))
2614 				return err;
2615 			if (unlikely(!link[TIPC_NLA_LINK_BROADCAST]))
2616 				return -EINVAL;
2617 			bc_link = true;
2618 		}
2619 	}
2620 
2621 	msg.skb = skb;
2622 	msg.portid = NETLINK_CB(cb->skb).portid;
2623 	msg.seq = cb->nlh->nlmsg_seq;
2624 
2625 	rcu_read_lock();
2626 	if (prev_node) {
2627 		node = tipc_node_find(net, prev_node);
2628 		if (!node) {
2629 			/* We never set seq or call nl_dump_check_consistent()
2630 			 * this means that setting prev_seq here will cause the
2631 			 * consistence check to fail in the netlink callback
2632 			 * handler. Resulting in the last NLMSG_DONE message
2633 			 * having the NLM_F_DUMP_INTR flag set.
2634 			 */
2635 			cb->prev_seq = 1;
2636 			goto out;
2637 		}
2638 		tipc_node_put(node);
2639 
2640 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2641 						 list) {
2642 			tipc_node_read_lock(node);
2643 			err = __tipc_nl_add_node_links(net, &msg, node,
2644 						       &prev_link, bc_link);
2645 			tipc_node_read_unlock(node);
2646 			if (err)
2647 				goto out;
2648 
2649 			prev_node = node->addr;
2650 		}
2651 	} else {
2652 		err = tipc_nl_add_bc_link(net, &msg, tn->bcl);
2653 		if (err)
2654 			goto out;
2655 
2656 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2657 			tipc_node_read_lock(node);
2658 			err = __tipc_nl_add_node_links(net, &msg, node,
2659 						       &prev_link, bc_link);
2660 			tipc_node_read_unlock(node);
2661 			if (err)
2662 				goto out;
2663 
2664 			prev_node = node->addr;
2665 		}
2666 	}
2667 	done = 1;
2668 out:
2669 	rcu_read_unlock();
2670 
2671 	cb->args[0] = prev_node;
2672 	cb->args[1] = prev_link;
2673 	cb->args[2] = done;
2674 	cb->args[3] = bc_link;
2675 
2676 	return skb->len;
2677 }
2678 
2679 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2680 {
2681 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2682 	struct net *net = sock_net(skb->sk);
2683 	int err;
2684 
2685 	if (!info->attrs[TIPC_NLA_MON])
2686 		return -EINVAL;
2687 
2688 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2689 					  info->attrs[TIPC_NLA_MON],
2690 					  tipc_nl_monitor_policy,
2691 					  info->extack);
2692 	if (err)
2693 		return err;
2694 
2695 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2696 		u32 val;
2697 
2698 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2699 		err = tipc_nl_monitor_set_threshold(net, val);
2700 		if (err)
2701 			return err;
2702 	}
2703 
2704 	return 0;
2705 }
2706 
2707 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2708 {
2709 	struct nlattr *attrs;
2710 	void *hdr;
2711 	u32 val;
2712 
2713 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2714 			  0, TIPC_NL_MON_GET);
2715 	if (!hdr)
2716 		return -EMSGSIZE;
2717 
2718 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2719 	if (!attrs)
2720 		goto msg_full;
2721 
2722 	val = tipc_nl_monitor_get_threshold(net);
2723 
2724 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2725 		goto attr_msg_full;
2726 
2727 	nla_nest_end(msg->skb, attrs);
2728 	genlmsg_end(msg->skb, hdr);
2729 
2730 	return 0;
2731 
2732 attr_msg_full:
2733 	nla_nest_cancel(msg->skb, attrs);
2734 msg_full:
2735 	genlmsg_cancel(msg->skb, hdr);
2736 
2737 	return -EMSGSIZE;
2738 }
2739 
2740 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2741 {
2742 	struct net *net = sock_net(skb->sk);
2743 	struct tipc_nl_msg msg;
2744 	int err;
2745 
2746 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2747 	if (!msg.skb)
2748 		return -ENOMEM;
2749 	msg.portid = info->snd_portid;
2750 	msg.seq = info->snd_seq;
2751 
2752 	err = __tipc_nl_add_monitor_prop(net, &msg);
2753 	if (err) {
2754 		nlmsg_free(msg.skb);
2755 		return err;
2756 	}
2757 
2758 	return genlmsg_reply(msg.skb, info);
2759 }
2760 
2761 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2762 {
2763 	struct net *net = sock_net(skb->sk);
2764 	u32 prev_bearer = cb->args[0];
2765 	struct tipc_nl_msg msg;
2766 	int bearer_id;
2767 	int err;
2768 
2769 	if (prev_bearer == MAX_BEARERS)
2770 		return 0;
2771 
2772 	msg.skb = skb;
2773 	msg.portid = NETLINK_CB(cb->skb).portid;
2774 	msg.seq = cb->nlh->nlmsg_seq;
2775 
2776 	rtnl_lock();
2777 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2778 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2779 		if (err)
2780 			break;
2781 	}
2782 	rtnl_unlock();
2783 	cb->args[0] = bearer_id;
2784 
2785 	return skb->len;
2786 }
2787 
2788 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2789 				   struct netlink_callback *cb)
2790 {
2791 	struct net *net = sock_net(skb->sk);
2792 	u32 prev_node = cb->args[1];
2793 	u32 bearer_id = cb->args[2];
2794 	int done = cb->args[0];
2795 	struct tipc_nl_msg msg;
2796 	int err;
2797 
2798 	if (!prev_node) {
2799 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2800 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2801 
2802 		if (!attrs[TIPC_NLA_MON])
2803 			return -EINVAL;
2804 
2805 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2806 						  attrs[TIPC_NLA_MON],
2807 						  tipc_nl_monitor_policy,
2808 						  NULL);
2809 		if (err)
2810 			return err;
2811 
2812 		if (!mon[TIPC_NLA_MON_REF])
2813 			return -EINVAL;
2814 
2815 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2816 
2817 		if (bearer_id >= MAX_BEARERS)
2818 			return -EINVAL;
2819 	}
2820 
2821 	if (done)
2822 		return 0;
2823 
2824 	msg.skb = skb;
2825 	msg.portid = NETLINK_CB(cb->skb).portid;
2826 	msg.seq = cb->nlh->nlmsg_seq;
2827 
2828 	rtnl_lock();
2829 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2830 	if (!err)
2831 		done = 1;
2832 
2833 	rtnl_unlock();
2834 	cb->args[0] = done;
2835 	cb->args[1] = prev_node;
2836 	cb->args[2] = bearer_id;
2837 
2838 	return skb->len;
2839 }
2840 
2841 #ifdef CONFIG_TIPC_CRYPTO
2842 static int tipc_nl_retrieve_key(struct nlattr **attrs,
2843 				struct tipc_aead_key **key)
2844 {
2845 	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
2846 
2847 	if (!attr)
2848 		return -ENODATA;
2849 
2850 	*key = (struct tipc_aead_key *)nla_data(attr);
2851 	if (nla_len(attr) < tipc_aead_key_size(*key))
2852 		return -EINVAL;
2853 
2854 	return 0;
2855 }
2856 
2857 static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
2858 {
2859 	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
2860 
2861 	if (!attr)
2862 		return -ENODATA;
2863 
2864 	if (nla_len(attr) < TIPC_NODEID_LEN)
2865 		return -EINVAL;
2866 
2867 	*node_id = (u8 *)nla_data(attr);
2868 	return 0;
2869 }
2870 
2871 static int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2872 {
2873 	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
2874 	struct net *net = sock_net(skb->sk);
2875 	struct tipc_net *tn = tipc_net(net);
2876 	struct tipc_node *n = NULL;
2877 	struct tipc_aead_key *ukey;
2878 	struct tipc_crypto *c;
2879 	u8 *id, *own_id;
2880 	int rc = 0;
2881 
2882 	if (!info->attrs[TIPC_NLA_NODE])
2883 		return -EINVAL;
2884 
2885 	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
2886 			      info->attrs[TIPC_NLA_NODE],
2887 			      tipc_nl_node_policy, info->extack);
2888 	if (rc)
2889 		goto exit;
2890 
2891 	own_id = tipc_own_id(net);
2892 	if (!own_id) {
2893 		rc = -EPERM;
2894 		goto exit;
2895 	}
2896 
2897 	rc = tipc_nl_retrieve_key(attrs, &ukey);
2898 	if (rc)
2899 		goto exit;
2900 
2901 	rc = tipc_aead_key_validate(ukey);
2902 	if (rc)
2903 		goto exit;
2904 
2905 	rc = tipc_nl_retrieve_nodeid(attrs, &id);
2906 	switch (rc) {
2907 	case -ENODATA:
2908 		/* Cluster key mode */
2909 		rc = tipc_crypto_key_init(tn->crypto_tx, ukey, CLUSTER_KEY);
2910 		break;
2911 	case 0:
2912 		/* Per-node key mode */
2913 		if (!memcmp(id, own_id, NODE_ID_LEN)) {
2914 			c = tn->crypto_tx;
2915 		} else {
2916 			n = tipc_node_find_by_id(net, id) ?:
2917 				tipc_node_create(net, 0, id, 0xffffu, 0, true);
2918 			if (unlikely(!n)) {
2919 				rc = -ENOMEM;
2920 				break;
2921 			}
2922 			c = n->crypto_rx;
2923 		}
2924 
2925 		rc = tipc_crypto_key_init(c, ukey, PER_NODE_KEY);
2926 		if (n)
2927 			tipc_node_put(n);
2928 		break;
2929 	default:
2930 		break;
2931 	}
2932 
2933 exit:
2934 	return (rc < 0) ? rc : 0;
2935 }
2936 
2937 int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2938 {
2939 	int err;
2940 
2941 	rtnl_lock();
2942 	err = __tipc_nl_node_set_key(skb, info);
2943 	rtnl_unlock();
2944 
2945 	return err;
2946 }
2947 
2948 static int __tipc_nl_node_flush_key(struct sk_buff *skb,
2949 				    struct genl_info *info)
2950 {
2951 	struct net *net = sock_net(skb->sk);
2952 	struct tipc_net *tn = tipc_net(net);
2953 	struct tipc_node *n;
2954 
2955 	tipc_crypto_key_flush(tn->crypto_tx);
2956 	rcu_read_lock();
2957 	list_for_each_entry_rcu(n, &tn->node_list, list)
2958 		tipc_crypto_key_flush(n->crypto_rx);
2959 	rcu_read_unlock();
2960 
2961 	pr_info("All keys are flushed!\n");
2962 	return 0;
2963 }
2964 
2965 int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
2966 {
2967 	int err;
2968 
2969 	rtnl_lock();
2970 	err = __tipc_nl_node_flush_key(skb, info);
2971 	rtnl_unlock();
2972 
2973 	return err;
2974 }
2975 #endif
2976 
2977 /**
2978  * tipc_node_dump - dump TIPC node data
2979  * @n: tipc node to be dumped
2980  * @more: dump more?
2981  *        - false: dump only tipc node data
2982  *        - true: dump node link data as well
2983  * @buf: returned buffer of dump data in format
2984  */
2985 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2986 {
2987 	int i = 0;
2988 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2989 
2990 	if (!n) {
2991 		i += scnprintf(buf, sz, "node data: (null)\n");
2992 		return i;
2993 	}
2994 
2995 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2996 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2997 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2998 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2999 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
3000 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
3001 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
3002 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
3003 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
3004 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
3005 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
3006 
3007 	if (!more)
3008 		return i;
3009 
3010 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
3011 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
3012 	i += scnprintf(buf + i, sz - i, " media: ");
3013 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
3014 	i += scnprintf(buf + i, sz - i, "\n");
3015 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
3016 	i += scnprintf(buf + i, sz - i, " inputq: ");
3017 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
3018 
3019 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
3020 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
3021 	i += scnprintf(buf + i, sz - i, " media: ");
3022 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
3023 	i += scnprintf(buf + i, sz - i, "\n");
3024 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
3025 	i += scnprintf(buf + i, sz - i, " inputq: ");
3026 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
3027 
3028 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
3029 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
3030 
3031 	return i;
3032 }
3033 
3034 void tipc_node_pre_cleanup_net(struct net *exit_net)
3035 {
3036 	struct tipc_node *n;
3037 	struct tipc_net *tn;
3038 	struct net *tmp;
3039 
3040 	rcu_read_lock();
3041 	for_each_net_rcu(tmp) {
3042 		if (tmp == exit_net)
3043 			continue;
3044 		tn = tipc_net(tmp);
3045 		if (!tn)
3046 			continue;
3047 		spin_lock_bh(&tn->node_list_lock);
3048 		list_for_each_entry_rcu(n, &tn->node_list, list) {
3049 			if (!n->peer_net)
3050 				continue;
3051 			if (n->peer_net != exit_net)
3052 				continue;
3053 			tipc_node_write_lock(n);
3054 			n->peer_net = NULL;
3055 			n->peer_hash_mix = 0;
3056 			tipc_node_write_unlock_fast(n);
3057 			break;
3058 		}
3059 		spin_unlock_bh(&tn->node_list_lock);
3060 	}
3061 	rcu_read_unlock();
3062 }
3063