xref: /openbmc/linux/net/tipc/node.c (revision b58c6630)
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 static 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_min_win(snd_l),
1143 					 tipc_link_max_win(snd_l),
1144 					 n->capabilities,
1145 					 &n->bc_entry.inputq1,
1146 					 &n->bc_entry.namedq, snd_l,
1147 					 &n->bc_entry.link)) {
1148 			pr_warn("Broadcast rcv link creation failed, no mem\n");
1149 			tipc_node_write_unlock_fast(n);
1150 			tipc_node_put(n);
1151 			return;
1152 		}
1153 	}
1154 
1155 	le = &n->links[b->identity];
1156 
1157 	/* Prepare to validate requesting node's signature and media address */
1158 	l = le->link;
1159 	link_up = l && tipc_link_is_up(l);
1160 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
1161 	sign_match = (signature == n->signature);
1162 
1163 	/* These three flags give us eight permutations: */
1164 
1165 	if (sign_match && addr_match && link_up) {
1166 		/* All is fine. Do nothing. */
1167 		reset = false;
1168 		/* Peer node is not a container/local namespace */
1169 		if (!n->peer_hash_mix)
1170 			n->peer_hash_mix = hash_mixes;
1171 	} else if (sign_match && addr_match && !link_up) {
1172 		/* Respond. The link will come up in due time */
1173 		*respond = true;
1174 	} else if (sign_match && !addr_match && link_up) {
1175 		/* Peer has changed i/f address without rebooting.
1176 		 * If so, the link will reset soon, and the next
1177 		 * discovery will be accepted. So we can ignore it.
1178 		 * It may also be an cloned or malicious peer having
1179 		 * chosen the same node address and signature as an
1180 		 * existing one.
1181 		 * Ignore requests until the link goes down, if ever.
1182 		 */
1183 		*dupl_addr = true;
1184 	} else if (sign_match && !addr_match && !link_up) {
1185 		/* Peer link has changed i/f address without rebooting.
1186 		 * It may also be a cloned or malicious peer; we can't
1187 		 * distinguish between the two.
1188 		 * The signature is correct, so we must accept.
1189 		 */
1190 		accept_addr = true;
1191 		*respond = true;
1192 	} else if (!sign_match && addr_match && link_up) {
1193 		/* Peer node rebooted. Two possibilities:
1194 		 *  - Delayed re-discovery; this link endpoint has already
1195 		 *    reset and re-established contact with the peer, before
1196 		 *    receiving a discovery message from that node.
1197 		 *    (The peer happened to receive one from this node first).
1198 		 *  - The peer came back so fast that our side has not
1199 		 *    discovered it yet. Probing from this side will soon
1200 		 *    reset the link, since there can be no working link
1201 		 *    endpoint at the peer end, and the link will re-establish.
1202 		 *  Accept the signature, since it comes from a known peer.
1203 		 */
1204 		n->signature = signature;
1205 	} else if (!sign_match && addr_match && !link_up) {
1206 		/*  The peer node has rebooted.
1207 		 *  Accept signature, since it is a known peer.
1208 		 */
1209 		n->signature = signature;
1210 		*respond = true;
1211 	} else if (!sign_match && !addr_match && link_up) {
1212 		/* Peer rebooted with new address, or a new/duplicate peer.
1213 		 * Ignore until the link goes down, if ever.
1214 		 */
1215 		*dupl_addr = true;
1216 	} else if (!sign_match && !addr_match && !link_up) {
1217 		/* Peer rebooted with new address, or it is a new peer.
1218 		 * Accept signature and address.
1219 		 */
1220 		n->signature = signature;
1221 		accept_addr = true;
1222 		*respond = true;
1223 	}
1224 
1225 	if (!accept_addr)
1226 		goto exit;
1227 
1228 	/* Now create new link if not already existing */
1229 	if (!l) {
1230 		if (n->link_cnt == 2)
1231 			goto exit;
1232 
1233 		if_name = strchr(b->name, ':') + 1;
1234 		get_random_bytes(&session, sizeof(u16));
1235 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1236 				      b->net_plane, b->mtu, b->priority,
1237 				      b->min_win, b->max_win, session,
1238 				      tipc_own_addr(net), addr, peer_id,
1239 				      n->capabilities,
1240 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1241 				      &le->inputq,
1242 				      &n->bc_entry.namedq, &l)) {
1243 			*respond = false;
1244 			goto exit;
1245 		}
1246 		trace_tipc_link_reset(l, TIPC_DUMP_ALL, "link created!");
1247 		tipc_link_reset(l);
1248 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1249 		if (n->state == NODE_FAILINGOVER)
1250 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1251 		le->link = l;
1252 		n->link_cnt++;
1253 		tipc_node_calculate_timer(n, l);
1254 		if (n->link_cnt == 1) {
1255 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1256 			if (!mod_timer(&n->timer, intv))
1257 				tipc_node_get(n);
1258 		}
1259 	}
1260 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1261 exit:
1262 	tipc_node_write_unlock(n);
1263 	if (reset && l && !tipc_link_is_reset(l))
1264 		tipc_node_link_down(n, b->identity, false);
1265 	tipc_node_put(n);
1266 }
1267 
1268 void tipc_node_delete_links(struct net *net, int bearer_id)
1269 {
1270 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1271 	struct tipc_node *n;
1272 
1273 	rcu_read_lock();
1274 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1275 		tipc_node_link_down(n, bearer_id, true);
1276 	}
1277 	rcu_read_unlock();
1278 }
1279 
1280 static void tipc_node_reset_links(struct tipc_node *n)
1281 {
1282 	int i;
1283 
1284 	pr_warn("Resetting all links to %x\n", n->addr);
1285 
1286 	trace_tipc_node_reset_links(n, true, " ");
1287 	for (i = 0; i < MAX_BEARERS; i++) {
1288 		tipc_node_link_down(n, i, false);
1289 	}
1290 }
1291 
1292 /* tipc_node_fsm_evt - node finite state machine
1293  * Determines when contact is allowed with peer node
1294  */
1295 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1296 {
1297 	int state = n->state;
1298 
1299 	switch (state) {
1300 	case SELF_DOWN_PEER_DOWN:
1301 		switch (evt) {
1302 		case SELF_ESTABL_CONTACT_EVT:
1303 			state = SELF_UP_PEER_COMING;
1304 			break;
1305 		case PEER_ESTABL_CONTACT_EVT:
1306 			state = SELF_COMING_PEER_UP;
1307 			break;
1308 		case SELF_LOST_CONTACT_EVT:
1309 		case PEER_LOST_CONTACT_EVT:
1310 			break;
1311 		case NODE_SYNCH_END_EVT:
1312 		case NODE_SYNCH_BEGIN_EVT:
1313 		case NODE_FAILOVER_BEGIN_EVT:
1314 		case NODE_FAILOVER_END_EVT:
1315 		default:
1316 			goto illegal_evt;
1317 		}
1318 		break;
1319 	case SELF_UP_PEER_UP:
1320 		switch (evt) {
1321 		case SELF_LOST_CONTACT_EVT:
1322 			state = SELF_DOWN_PEER_LEAVING;
1323 			break;
1324 		case PEER_LOST_CONTACT_EVT:
1325 			state = SELF_LEAVING_PEER_DOWN;
1326 			break;
1327 		case NODE_SYNCH_BEGIN_EVT:
1328 			state = NODE_SYNCHING;
1329 			break;
1330 		case NODE_FAILOVER_BEGIN_EVT:
1331 			state = NODE_FAILINGOVER;
1332 			break;
1333 		case SELF_ESTABL_CONTACT_EVT:
1334 		case PEER_ESTABL_CONTACT_EVT:
1335 		case NODE_SYNCH_END_EVT:
1336 		case NODE_FAILOVER_END_EVT:
1337 			break;
1338 		default:
1339 			goto illegal_evt;
1340 		}
1341 		break;
1342 	case SELF_DOWN_PEER_LEAVING:
1343 		switch (evt) {
1344 		case PEER_LOST_CONTACT_EVT:
1345 			state = SELF_DOWN_PEER_DOWN;
1346 			break;
1347 		case SELF_ESTABL_CONTACT_EVT:
1348 		case PEER_ESTABL_CONTACT_EVT:
1349 		case SELF_LOST_CONTACT_EVT:
1350 			break;
1351 		case NODE_SYNCH_END_EVT:
1352 		case NODE_SYNCH_BEGIN_EVT:
1353 		case NODE_FAILOVER_BEGIN_EVT:
1354 		case NODE_FAILOVER_END_EVT:
1355 		default:
1356 			goto illegal_evt;
1357 		}
1358 		break;
1359 	case SELF_UP_PEER_COMING:
1360 		switch (evt) {
1361 		case PEER_ESTABL_CONTACT_EVT:
1362 			state = SELF_UP_PEER_UP;
1363 			break;
1364 		case SELF_LOST_CONTACT_EVT:
1365 			state = SELF_DOWN_PEER_DOWN;
1366 			break;
1367 		case SELF_ESTABL_CONTACT_EVT:
1368 		case PEER_LOST_CONTACT_EVT:
1369 		case NODE_SYNCH_END_EVT:
1370 		case NODE_FAILOVER_BEGIN_EVT:
1371 			break;
1372 		case NODE_SYNCH_BEGIN_EVT:
1373 		case NODE_FAILOVER_END_EVT:
1374 		default:
1375 			goto illegal_evt;
1376 		}
1377 		break;
1378 	case SELF_COMING_PEER_UP:
1379 		switch (evt) {
1380 		case SELF_ESTABL_CONTACT_EVT:
1381 			state = SELF_UP_PEER_UP;
1382 			break;
1383 		case PEER_LOST_CONTACT_EVT:
1384 			state = SELF_DOWN_PEER_DOWN;
1385 			break;
1386 		case SELF_LOST_CONTACT_EVT:
1387 		case PEER_ESTABL_CONTACT_EVT:
1388 			break;
1389 		case NODE_SYNCH_END_EVT:
1390 		case NODE_SYNCH_BEGIN_EVT:
1391 		case NODE_FAILOVER_BEGIN_EVT:
1392 		case NODE_FAILOVER_END_EVT:
1393 		default:
1394 			goto illegal_evt;
1395 		}
1396 		break;
1397 	case SELF_LEAVING_PEER_DOWN:
1398 		switch (evt) {
1399 		case SELF_LOST_CONTACT_EVT:
1400 			state = SELF_DOWN_PEER_DOWN;
1401 			break;
1402 		case SELF_ESTABL_CONTACT_EVT:
1403 		case PEER_ESTABL_CONTACT_EVT:
1404 		case PEER_LOST_CONTACT_EVT:
1405 			break;
1406 		case NODE_SYNCH_END_EVT:
1407 		case NODE_SYNCH_BEGIN_EVT:
1408 		case NODE_FAILOVER_BEGIN_EVT:
1409 		case NODE_FAILOVER_END_EVT:
1410 		default:
1411 			goto illegal_evt;
1412 		}
1413 		break;
1414 	case NODE_FAILINGOVER:
1415 		switch (evt) {
1416 		case SELF_LOST_CONTACT_EVT:
1417 			state = SELF_DOWN_PEER_LEAVING;
1418 			break;
1419 		case PEER_LOST_CONTACT_EVT:
1420 			state = SELF_LEAVING_PEER_DOWN;
1421 			break;
1422 		case NODE_FAILOVER_END_EVT:
1423 			state = SELF_UP_PEER_UP;
1424 			break;
1425 		case NODE_FAILOVER_BEGIN_EVT:
1426 		case SELF_ESTABL_CONTACT_EVT:
1427 		case PEER_ESTABL_CONTACT_EVT:
1428 			break;
1429 		case NODE_SYNCH_BEGIN_EVT:
1430 		case NODE_SYNCH_END_EVT:
1431 		default:
1432 			goto illegal_evt;
1433 		}
1434 		break;
1435 	case NODE_SYNCHING:
1436 		switch (evt) {
1437 		case SELF_LOST_CONTACT_EVT:
1438 			state = SELF_DOWN_PEER_LEAVING;
1439 			break;
1440 		case PEER_LOST_CONTACT_EVT:
1441 			state = SELF_LEAVING_PEER_DOWN;
1442 			break;
1443 		case NODE_SYNCH_END_EVT:
1444 			state = SELF_UP_PEER_UP;
1445 			break;
1446 		case NODE_FAILOVER_BEGIN_EVT:
1447 			state = NODE_FAILINGOVER;
1448 			break;
1449 		case NODE_SYNCH_BEGIN_EVT:
1450 		case SELF_ESTABL_CONTACT_EVT:
1451 		case PEER_ESTABL_CONTACT_EVT:
1452 			break;
1453 		case NODE_FAILOVER_END_EVT:
1454 		default:
1455 			goto illegal_evt;
1456 		}
1457 		break;
1458 	default:
1459 		pr_err("Unknown node fsm state %x\n", state);
1460 		break;
1461 	}
1462 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1463 	n->state = state;
1464 	return;
1465 
1466 illegal_evt:
1467 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1468 	trace_tipc_node_fsm(n->peer_id, n->state, state, evt);
1469 }
1470 
1471 static void node_lost_contact(struct tipc_node *n,
1472 			      struct sk_buff_head *inputq)
1473 {
1474 	struct tipc_sock_conn *conn, *safe;
1475 	struct tipc_link *l;
1476 	struct list_head *conns = &n->conn_sks;
1477 	struct sk_buff *skb;
1478 	uint i;
1479 
1480 	pr_debug("Lost contact with %x\n", n->addr);
1481 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1482 	trace_tipc_node_lost_contact(n, true, " ");
1483 
1484 	/* Clean up broadcast state */
1485 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1486 
1487 	/* Abort any ongoing link failover */
1488 	for (i = 0; i < MAX_BEARERS; i++) {
1489 		l = n->links[i].link;
1490 		if (l)
1491 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1492 	}
1493 
1494 	/* Notify publications from this node */
1495 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1496 	n->peer_net = NULL;
1497 	n->peer_hash_mix = 0;
1498 	/* Notify sockets connected to node */
1499 	list_for_each_entry_safe(conn, safe, conns, list) {
1500 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1501 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1502 				      conn->peer_node, conn->port,
1503 				      conn->peer_port, TIPC_ERR_NO_NODE);
1504 		if (likely(skb))
1505 			skb_queue_tail(inputq, skb);
1506 		list_del(&conn->list);
1507 		kfree(conn);
1508 	}
1509 }
1510 
1511 /**
1512  * tipc_node_get_linkname - get the name of a link
1513  *
1514  * @bearer_id: id of the bearer
1515  * @node: peer node address
1516  * @linkname: link name output buffer
1517  *
1518  * Returns 0 on success
1519  */
1520 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1521 			   char *linkname, size_t len)
1522 {
1523 	struct tipc_link *link;
1524 	int err = -EINVAL;
1525 	struct tipc_node *node = tipc_node_find(net, addr);
1526 
1527 	if (!node)
1528 		return err;
1529 
1530 	if (bearer_id >= MAX_BEARERS)
1531 		goto exit;
1532 
1533 	tipc_node_read_lock(node);
1534 	link = node->links[bearer_id].link;
1535 	if (link) {
1536 		strncpy(linkname, tipc_link_name(link), len);
1537 		err = 0;
1538 	}
1539 	tipc_node_read_unlock(node);
1540 exit:
1541 	tipc_node_put(node);
1542 	return err;
1543 }
1544 
1545 /* Caller should hold node lock for the passed node */
1546 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1547 {
1548 	void *hdr;
1549 	struct nlattr *attrs;
1550 
1551 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1552 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1553 	if (!hdr)
1554 		return -EMSGSIZE;
1555 
1556 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_NODE);
1557 	if (!attrs)
1558 		goto msg_full;
1559 
1560 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1561 		goto attr_msg_full;
1562 	if (node_is_up(node))
1563 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1564 			goto attr_msg_full;
1565 
1566 	nla_nest_end(msg->skb, attrs);
1567 	genlmsg_end(msg->skb, hdr);
1568 
1569 	return 0;
1570 
1571 attr_msg_full:
1572 	nla_nest_cancel(msg->skb, attrs);
1573 msg_full:
1574 	genlmsg_cancel(msg->skb, hdr);
1575 
1576 	return -EMSGSIZE;
1577 }
1578 
1579 static void tipc_lxc_xmit(struct net *peer_net, struct sk_buff_head *list)
1580 {
1581 	struct tipc_msg *hdr = buf_msg(skb_peek(list));
1582 	struct sk_buff_head inputq;
1583 
1584 	switch (msg_user(hdr)) {
1585 	case TIPC_LOW_IMPORTANCE:
1586 	case TIPC_MEDIUM_IMPORTANCE:
1587 	case TIPC_HIGH_IMPORTANCE:
1588 	case TIPC_CRITICAL_IMPORTANCE:
1589 		if (msg_connected(hdr) || msg_named(hdr) ||
1590 		    msg_direct(hdr)) {
1591 			tipc_loopback_trace(peer_net, list);
1592 			spin_lock_init(&list->lock);
1593 			tipc_sk_rcv(peer_net, list);
1594 			return;
1595 		}
1596 		if (msg_mcast(hdr)) {
1597 			tipc_loopback_trace(peer_net, list);
1598 			skb_queue_head_init(&inputq);
1599 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1600 			__skb_queue_purge(list);
1601 			skb_queue_purge(&inputq);
1602 			return;
1603 		}
1604 		return;
1605 	case MSG_FRAGMENTER:
1606 		if (tipc_msg_assemble(list)) {
1607 			tipc_loopback_trace(peer_net, list);
1608 			skb_queue_head_init(&inputq);
1609 			tipc_sk_mcast_rcv(peer_net, list, &inputq);
1610 			__skb_queue_purge(list);
1611 			skb_queue_purge(&inputq);
1612 		}
1613 		return;
1614 	case GROUP_PROTOCOL:
1615 	case CONN_MANAGER:
1616 		tipc_loopback_trace(peer_net, list);
1617 		spin_lock_init(&list->lock);
1618 		tipc_sk_rcv(peer_net, list);
1619 		return;
1620 	case LINK_PROTOCOL:
1621 	case NAME_DISTRIBUTOR:
1622 	case TUNNEL_PROTOCOL:
1623 	case BCAST_PROTOCOL:
1624 		return;
1625 	default:
1626 		return;
1627 	};
1628 }
1629 
1630 /**
1631  * tipc_node_xmit() is the general link level function for message sending
1632  * @net: the applicable net namespace
1633  * @list: chain of buffers containing message
1634  * @dnode: address of destination node
1635  * @selector: a number used for deterministic link selection
1636  * Consumes the buffer chain.
1637  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1638  */
1639 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1640 		   u32 dnode, int selector)
1641 {
1642 	struct tipc_link_entry *le = NULL;
1643 	struct tipc_node *n;
1644 	struct sk_buff_head xmitq;
1645 	bool node_up = false;
1646 	int bearer_id;
1647 	int rc;
1648 
1649 	if (in_own_node(net, dnode)) {
1650 		tipc_loopback_trace(net, list);
1651 		spin_lock_init(&list->lock);
1652 		tipc_sk_rcv(net, list);
1653 		return 0;
1654 	}
1655 
1656 	n = tipc_node_find(net, dnode);
1657 	if (unlikely(!n)) {
1658 		__skb_queue_purge(list);
1659 		return -EHOSTUNREACH;
1660 	}
1661 
1662 	tipc_node_read_lock(n);
1663 	node_up = node_is_up(n);
1664 	if (node_up && n->peer_net && check_net(n->peer_net)) {
1665 		/* xmit inner linux container */
1666 		tipc_lxc_xmit(n->peer_net, list);
1667 		if (likely(skb_queue_empty(list))) {
1668 			tipc_node_read_unlock(n);
1669 			tipc_node_put(n);
1670 			return 0;
1671 		}
1672 	}
1673 
1674 	bearer_id = n->active_links[selector & 1];
1675 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1676 		tipc_node_read_unlock(n);
1677 		tipc_node_put(n);
1678 		__skb_queue_purge(list);
1679 		return -EHOSTUNREACH;
1680 	}
1681 
1682 	__skb_queue_head_init(&xmitq);
1683 	le = &n->links[bearer_id];
1684 	spin_lock_bh(&le->lock);
1685 	rc = tipc_link_xmit(le->link, list, &xmitq);
1686 	spin_unlock_bh(&le->lock);
1687 	tipc_node_read_unlock(n);
1688 
1689 	if (unlikely(rc == -ENOBUFS))
1690 		tipc_node_link_down(n, bearer_id, false);
1691 	else
1692 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1693 
1694 	tipc_node_put(n);
1695 
1696 	return rc;
1697 }
1698 
1699 /* tipc_node_xmit_skb(): send single buffer to destination
1700  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1701  * messages, which will not be rejected
1702  * The only exception is datagram messages rerouted after secondary
1703  * lookup, which are rare and safe to dispose of anyway.
1704  */
1705 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1706 		       u32 selector)
1707 {
1708 	struct sk_buff_head head;
1709 
1710 	__skb_queue_head_init(&head);
1711 	__skb_queue_tail(&head, skb);
1712 	tipc_node_xmit(net, &head, dnode, selector);
1713 	return 0;
1714 }
1715 
1716 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1717  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1718  */
1719 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1720 {
1721 	struct sk_buff *skb;
1722 	u32 selector, dnode;
1723 
1724 	while ((skb = __skb_dequeue(xmitq))) {
1725 		selector = msg_origport(buf_msg(skb));
1726 		dnode = msg_destnode(buf_msg(skb));
1727 		tipc_node_xmit_skb(net, skb, dnode, selector);
1728 	}
1729 	return 0;
1730 }
1731 
1732 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1733 {
1734 	struct sk_buff *txskb;
1735 	struct tipc_node *n;
1736 	u32 dst;
1737 
1738 	rcu_read_lock();
1739 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1740 		dst = n->addr;
1741 		if (in_own_node(net, dst))
1742 			continue;
1743 		if (!node_is_up(n))
1744 			continue;
1745 		txskb = pskb_copy(skb, GFP_ATOMIC);
1746 		if (!txskb)
1747 			break;
1748 		msg_set_destnode(buf_msg(txskb), dst);
1749 		tipc_node_xmit_skb(net, txskb, dst, 0);
1750 	}
1751 	rcu_read_unlock();
1752 
1753 	kfree_skb(skb);
1754 }
1755 
1756 static void tipc_node_mcast_rcv(struct tipc_node *n)
1757 {
1758 	struct tipc_bclink_entry *be = &n->bc_entry;
1759 
1760 	/* 'arrvq' is under inputq2's lock protection */
1761 	spin_lock_bh(&be->inputq2.lock);
1762 	spin_lock_bh(&be->inputq1.lock);
1763 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1764 	spin_unlock_bh(&be->inputq1.lock);
1765 	spin_unlock_bh(&be->inputq2.lock);
1766 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1767 }
1768 
1769 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1770 				  int bearer_id, struct sk_buff_head *xmitq)
1771 {
1772 	struct tipc_link *ucl;
1773 	int rc;
1774 
1775 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1776 
1777 	if (rc & TIPC_LINK_DOWN_EVT) {
1778 		tipc_node_reset_links(n);
1779 		return;
1780 	}
1781 
1782 	if (!(rc & TIPC_LINK_SND_STATE))
1783 		return;
1784 
1785 	/* If probe message, a STATE response will be sent anyway */
1786 	if (msg_probe(hdr))
1787 		return;
1788 
1789 	/* Produce a STATE message carrying broadcast NACK */
1790 	tipc_node_read_lock(n);
1791 	ucl = n->links[bearer_id].link;
1792 	if (ucl)
1793 		tipc_link_build_state_msg(ucl, xmitq);
1794 	tipc_node_read_unlock(n);
1795 }
1796 
1797 /**
1798  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1799  * @net: the applicable net namespace
1800  * @skb: TIPC packet
1801  * @bearer_id: id of bearer message arrived on
1802  *
1803  * Invoked with no locks held.
1804  */
1805 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1806 {
1807 	int rc;
1808 	struct sk_buff_head xmitq;
1809 	struct tipc_bclink_entry *be;
1810 	struct tipc_link_entry *le;
1811 	struct tipc_msg *hdr = buf_msg(skb);
1812 	int usr = msg_user(hdr);
1813 	u32 dnode = msg_destnode(hdr);
1814 	struct tipc_node *n;
1815 
1816 	__skb_queue_head_init(&xmitq);
1817 
1818 	/* If NACK for other node, let rcv link for that node peek into it */
1819 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1820 		n = tipc_node_find(net, dnode);
1821 	else
1822 		n = tipc_node_find(net, msg_prevnode(hdr));
1823 	if (!n) {
1824 		kfree_skb(skb);
1825 		return;
1826 	}
1827 	be = &n->bc_entry;
1828 	le = &n->links[bearer_id];
1829 
1830 	rc = tipc_bcast_rcv(net, be->link, skb);
1831 
1832 	/* Broadcast ACKs are sent on a unicast link */
1833 	if (rc & TIPC_LINK_SND_STATE) {
1834 		tipc_node_read_lock(n);
1835 		tipc_link_build_state_msg(le->link, &xmitq);
1836 		tipc_node_read_unlock(n);
1837 	}
1838 
1839 	if (!skb_queue_empty(&xmitq))
1840 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
1841 
1842 	if (!skb_queue_empty(&be->inputq1))
1843 		tipc_node_mcast_rcv(n);
1844 
1845 	/* Handle NAME_DISTRIBUTOR messages sent from 1.7 nodes */
1846 	if (!skb_queue_empty(&n->bc_entry.namedq))
1847 		tipc_named_rcv(net, &n->bc_entry.namedq);
1848 
1849 	/* If reassembly or retransmission failure => reset all links to peer */
1850 	if (rc & TIPC_LINK_DOWN_EVT)
1851 		tipc_node_reset_links(n);
1852 
1853 	tipc_node_put(n);
1854 }
1855 
1856 /**
1857  * tipc_node_check_state - check and if necessary update node state
1858  * @skb: TIPC packet
1859  * @bearer_id: identity of bearer delivering the packet
1860  * Returns true if state and msg are ok, otherwise false
1861  */
1862 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1863 				  int bearer_id, struct sk_buff_head *xmitq)
1864 {
1865 	struct tipc_msg *hdr = buf_msg(skb);
1866 	int usr = msg_user(hdr);
1867 	int mtyp = msg_type(hdr);
1868 	u16 oseqno = msg_seqno(hdr);
1869 	u16 exp_pkts = msg_msgcnt(hdr);
1870 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1871 	int state = n->state;
1872 	struct tipc_link *l, *tnl, *pl = NULL;
1873 	struct tipc_media_addr *maddr;
1874 	int pb_id;
1875 
1876 	if (trace_tipc_node_check_state_enabled()) {
1877 		trace_tipc_skb_dump(skb, false, "skb for node state check");
1878 		trace_tipc_node_check_state(n, true, " ");
1879 	}
1880 	l = n->links[bearer_id].link;
1881 	if (!l)
1882 		return false;
1883 	rcv_nxt = tipc_link_rcv_nxt(l);
1884 
1885 
1886 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1887 		return true;
1888 
1889 	/* Find parallel link, if any */
1890 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1891 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1892 			pl = n->links[pb_id].link;
1893 			break;
1894 		}
1895 	}
1896 
1897 	if (!tipc_link_validate_msg(l, hdr)) {
1898 		trace_tipc_skb_dump(skb, false, "PROTO invalid (2)!");
1899 		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (2)!");
1900 		return false;
1901 	}
1902 
1903 	/* Check and update node accesibility if applicable */
1904 	if (state == SELF_UP_PEER_COMING) {
1905 		if (!tipc_link_is_up(l))
1906 			return true;
1907 		if (!msg_peer_link_is_up(hdr))
1908 			return true;
1909 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1910 	}
1911 
1912 	if (state == SELF_DOWN_PEER_LEAVING) {
1913 		if (msg_peer_node_is_up(hdr))
1914 			return false;
1915 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1916 		return true;
1917 	}
1918 
1919 	if (state == SELF_LEAVING_PEER_DOWN)
1920 		return false;
1921 
1922 	/* Ignore duplicate packets */
1923 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1924 		return true;
1925 
1926 	/* Initiate or update failover mode if applicable */
1927 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1928 		syncpt = oseqno + exp_pkts - 1;
1929 		if (pl && !tipc_link_is_reset(pl)) {
1930 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1931 			trace_tipc_node_link_down(n, true,
1932 						  "node link down <- failover!");
1933 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1934 							tipc_link_inputq(l));
1935 		}
1936 
1937 		/* If parallel link was already down, and this happened before
1938 		 * the tunnel link came up, node failover was never started.
1939 		 * Ensure that a FAILOVER_MSG is sent to get peer out of
1940 		 * NODE_FAILINGOVER state, also this node must accept
1941 		 * TUNNEL_MSGs from peer.
1942 		 */
1943 		if (n->state != NODE_FAILINGOVER)
1944 			tipc_node_link_failover(n, pl, l, xmitq);
1945 
1946 		/* If pkts arrive out of order, use lowest calculated syncpt */
1947 		if (less(syncpt, n->sync_point))
1948 			n->sync_point = syncpt;
1949 	}
1950 
1951 	/* Open parallel link when tunnel link reaches synch point */
1952 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1953 		if (!more(rcv_nxt, n->sync_point))
1954 			return true;
1955 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1956 		if (pl)
1957 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1958 		return true;
1959 	}
1960 
1961 	/* No synching needed if only one link */
1962 	if (!pl || !tipc_link_is_up(pl))
1963 		return true;
1964 
1965 	/* Initiate synch mode if applicable */
1966 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1967 		if (n->capabilities & TIPC_TUNNEL_ENHANCED)
1968 			syncpt = msg_syncpt(hdr);
1969 		else
1970 			syncpt = msg_seqno(msg_inner_hdr(hdr)) + exp_pkts - 1;
1971 		if (!tipc_link_is_up(l))
1972 			__tipc_node_link_up(n, bearer_id, xmitq);
1973 		if (n->state == SELF_UP_PEER_UP) {
1974 			n->sync_point = syncpt;
1975 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1976 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1977 		}
1978 	}
1979 
1980 	/* Open tunnel link when parallel link reaches synch point */
1981 	if (n->state == NODE_SYNCHING) {
1982 		if (tipc_link_is_synching(l)) {
1983 			tnl = l;
1984 		} else {
1985 			tnl = pl;
1986 			pl = l;
1987 		}
1988 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
1989 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1990 		if (more(dlv_nxt, n->sync_point)) {
1991 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1992 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1993 			return true;
1994 		}
1995 		if (l == pl)
1996 			return true;
1997 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1998 			return true;
1999 		if (usr == LINK_PROTOCOL)
2000 			return true;
2001 		return false;
2002 	}
2003 	return true;
2004 }
2005 
2006 /**
2007  * tipc_rcv - process TIPC packets/messages arriving from off-node
2008  * @net: the applicable net namespace
2009  * @skb: TIPC packet
2010  * @bearer: pointer to bearer message arrived on
2011  *
2012  * Invoked with no locks held. Bearer pointer must point to a valid bearer
2013  * structure (i.e. cannot be NULL), but bearer can be inactive.
2014  */
2015 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
2016 {
2017 	struct sk_buff_head xmitq;
2018 	struct tipc_link_entry *le;
2019 	struct tipc_msg *hdr;
2020 	struct tipc_node *n;
2021 	int bearer_id = b->identity;
2022 	u32 self = tipc_own_addr(net);
2023 	int usr, rc = 0;
2024 	u16 bc_ack;
2025 #ifdef CONFIG_TIPC_CRYPTO
2026 	struct tipc_ehdr *ehdr;
2027 
2028 	/* Check if message must be decrypted first */
2029 	if (TIPC_SKB_CB(skb)->decrypted || !tipc_ehdr_validate(skb))
2030 		goto rcv;
2031 
2032 	ehdr = (struct tipc_ehdr *)skb->data;
2033 	if (likely(ehdr->user != LINK_CONFIG)) {
2034 		n = tipc_node_find(net, ntohl(ehdr->addr));
2035 		if (unlikely(!n))
2036 			goto discard;
2037 	} else {
2038 		n = tipc_node_find_by_id(net, ehdr->id);
2039 	}
2040 	tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
2041 	tipc_node_put(n);
2042 	if (!skb)
2043 		return;
2044 
2045 rcv:
2046 #endif
2047 	/* Ensure message is well-formed before touching the header */
2048 	if (unlikely(!tipc_msg_validate(&skb)))
2049 		goto discard;
2050 	__skb_queue_head_init(&xmitq);
2051 	hdr = buf_msg(skb);
2052 	usr = msg_user(hdr);
2053 	bc_ack = msg_bcast_ack(hdr);
2054 
2055 	/* Handle arrival of discovery or broadcast packet */
2056 	if (unlikely(msg_non_seq(hdr))) {
2057 		if (unlikely(usr == LINK_CONFIG))
2058 			return tipc_disc_rcv(net, skb, b);
2059 		else
2060 			return tipc_node_bc_rcv(net, skb, bearer_id);
2061 	}
2062 
2063 	/* Discard unicast link messages destined for another node */
2064 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
2065 		goto discard;
2066 
2067 	/* Locate neighboring node that sent packet */
2068 	n = tipc_node_find(net, msg_prevnode(hdr));
2069 	if (unlikely(!n))
2070 		goto discard;
2071 	le = &n->links[bearer_id];
2072 
2073 	/* Ensure broadcast reception is in synch with peer's send state */
2074 	if (unlikely(usr == LINK_PROTOCOL))
2075 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
2076 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
2077 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
2078 
2079 	/* Receive packet directly if conditions permit */
2080 	tipc_node_read_lock(n);
2081 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
2082 		spin_lock_bh(&le->lock);
2083 		if (le->link) {
2084 			rc = tipc_link_rcv(le->link, skb, &xmitq);
2085 			skb = NULL;
2086 		}
2087 		spin_unlock_bh(&le->lock);
2088 	}
2089 	tipc_node_read_unlock(n);
2090 
2091 	/* Check/update node state before receiving */
2092 	if (unlikely(skb)) {
2093 		if (unlikely(skb_linearize(skb)))
2094 			goto out_node_put;
2095 		tipc_node_write_lock(n);
2096 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
2097 			if (le->link) {
2098 				rc = tipc_link_rcv(le->link, skb, &xmitq);
2099 				skb = NULL;
2100 			}
2101 		}
2102 		tipc_node_write_unlock(n);
2103 	}
2104 
2105 	if (unlikely(rc & TIPC_LINK_UP_EVT))
2106 		tipc_node_link_up(n, bearer_id, &xmitq);
2107 
2108 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
2109 		tipc_node_link_down(n, bearer_id, false);
2110 
2111 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
2112 		tipc_named_rcv(net, &n->bc_entry.namedq);
2113 
2114 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
2115 		tipc_node_mcast_rcv(n);
2116 
2117 	if (!skb_queue_empty(&le->inputq))
2118 		tipc_sk_rcv(net, &le->inputq);
2119 
2120 	if (!skb_queue_empty(&xmitq))
2121 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
2122 
2123 out_node_put:
2124 	tipc_node_put(n);
2125 discard:
2126 	kfree_skb(skb);
2127 }
2128 
2129 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
2130 			      int prop)
2131 {
2132 	struct tipc_net *tn = tipc_net(net);
2133 	int bearer_id = b->identity;
2134 	struct sk_buff_head xmitq;
2135 	struct tipc_link_entry *e;
2136 	struct tipc_node *n;
2137 
2138 	__skb_queue_head_init(&xmitq);
2139 
2140 	rcu_read_lock();
2141 
2142 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2143 		tipc_node_write_lock(n);
2144 		e = &n->links[bearer_id];
2145 		if (e->link) {
2146 			if (prop == TIPC_NLA_PROP_TOL)
2147 				tipc_link_set_tolerance(e->link, b->tolerance,
2148 							&xmitq);
2149 			else if (prop == TIPC_NLA_PROP_MTU)
2150 				tipc_link_set_mtu(e->link, b->mtu);
2151 		}
2152 		tipc_node_write_unlock(n);
2153 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
2154 	}
2155 
2156 	rcu_read_unlock();
2157 }
2158 
2159 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
2160 {
2161 	struct net *net = sock_net(skb->sk);
2162 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2163 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
2164 	struct tipc_node *peer, *temp_node;
2165 	u32 addr;
2166 	int err;
2167 
2168 	/* We identify the peer by its net */
2169 	if (!info->attrs[TIPC_NLA_NET])
2170 		return -EINVAL;
2171 
2172 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
2173 					  info->attrs[TIPC_NLA_NET],
2174 					  tipc_nl_net_policy, info->extack);
2175 	if (err)
2176 		return err;
2177 
2178 	if (!attrs[TIPC_NLA_NET_ADDR])
2179 		return -EINVAL;
2180 
2181 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
2182 
2183 	if (in_own_node(net, addr))
2184 		return -ENOTSUPP;
2185 
2186 	spin_lock_bh(&tn->node_list_lock);
2187 	peer = tipc_node_find(net, addr);
2188 	if (!peer) {
2189 		spin_unlock_bh(&tn->node_list_lock);
2190 		return -ENXIO;
2191 	}
2192 
2193 	tipc_node_write_lock(peer);
2194 	if (peer->state != SELF_DOWN_PEER_DOWN &&
2195 	    peer->state != SELF_DOWN_PEER_LEAVING) {
2196 		tipc_node_write_unlock(peer);
2197 		err = -EBUSY;
2198 		goto err_out;
2199 	}
2200 
2201 	tipc_node_clear_links(peer);
2202 	tipc_node_write_unlock(peer);
2203 	tipc_node_delete(peer);
2204 
2205 	/* Calculate cluster capabilities */
2206 	tn->capabilities = TIPC_NODE_CAPABILITIES;
2207 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
2208 		tn->capabilities &= temp_node->capabilities;
2209 	}
2210 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
2211 	err = 0;
2212 err_out:
2213 	tipc_node_put(peer);
2214 	spin_unlock_bh(&tn->node_list_lock);
2215 
2216 	return err;
2217 }
2218 
2219 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
2220 {
2221 	int err;
2222 	struct net *net = sock_net(skb->sk);
2223 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2224 	int done = cb->args[0];
2225 	int last_addr = cb->args[1];
2226 	struct tipc_node *node;
2227 	struct tipc_nl_msg msg;
2228 
2229 	if (done)
2230 		return 0;
2231 
2232 	msg.skb = skb;
2233 	msg.portid = NETLINK_CB(cb->skb).portid;
2234 	msg.seq = cb->nlh->nlmsg_seq;
2235 
2236 	rcu_read_lock();
2237 	if (last_addr) {
2238 		node = tipc_node_find(net, last_addr);
2239 		if (!node) {
2240 			rcu_read_unlock();
2241 			/* We never set seq or call nl_dump_check_consistent()
2242 			 * this means that setting prev_seq here will cause the
2243 			 * consistence check to fail in the netlink callback
2244 			 * handler. Resulting in the NLMSG_DONE message having
2245 			 * the NLM_F_DUMP_INTR flag set if the node state
2246 			 * changed while we released the lock.
2247 			 */
2248 			cb->prev_seq = 1;
2249 			return -EPIPE;
2250 		}
2251 		tipc_node_put(node);
2252 	}
2253 
2254 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2255 		if (node->preliminary)
2256 			continue;
2257 		if (last_addr) {
2258 			if (node->addr == last_addr)
2259 				last_addr = 0;
2260 			else
2261 				continue;
2262 		}
2263 
2264 		tipc_node_read_lock(node);
2265 		err = __tipc_nl_add_node(&msg, node);
2266 		if (err) {
2267 			last_addr = node->addr;
2268 			tipc_node_read_unlock(node);
2269 			goto out;
2270 		}
2271 
2272 		tipc_node_read_unlock(node);
2273 	}
2274 	done = 1;
2275 out:
2276 	cb->args[0] = done;
2277 	cb->args[1] = last_addr;
2278 	rcu_read_unlock();
2279 
2280 	return skb->len;
2281 }
2282 
2283 /* tipc_node_find_by_name - locate owner node of link by link's name
2284  * @net: the applicable net namespace
2285  * @name: pointer to link name string
2286  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2287  *
2288  * Returns pointer to node owning the link, or 0 if no matching link is found.
2289  */
2290 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2291 						const char *link_name,
2292 						unsigned int *bearer_id)
2293 {
2294 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2295 	struct tipc_link *l;
2296 	struct tipc_node *n;
2297 	struct tipc_node *found_node = NULL;
2298 	int i;
2299 
2300 	*bearer_id = 0;
2301 	rcu_read_lock();
2302 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2303 		tipc_node_read_lock(n);
2304 		for (i = 0; i < MAX_BEARERS; i++) {
2305 			l = n->links[i].link;
2306 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2307 				*bearer_id = i;
2308 				found_node = n;
2309 				break;
2310 			}
2311 		}
2312 		tipc_node_read_unlock(n);
2313 		if (found_node)
2314 			break;
2315 	}
2316 	rcu_read_unlock();
2317 
2318 	return found_node;
2319 }
2320 
2321 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2322 {
2323 	int err;
2324 	int res = 0;
2325 	int bearer_id;
2326 	char *name;
2327 	struct tipc_link *link;
2328 	struct tipc_node *node;
2329 	struct sk_buff_head xmitq;
2330 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2331 	struct net *net = sock_net(skb->sk);
2332 
2333 	__skb_queue_head_init(&xmitq);
2334 
2335 	if (!info->attrs[TIPC_NLA_LINK])
2336 		return -EINVAL;
2337 
2338 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2339 					  info->attrs[TIPC_NLA_LINK],
2340 					  tipc_nl_link_policy, info->extack);
2341 	if (err)
2342 		return err;
2343 
2344 	if (!attrs[TIPC_NLA_LINK_NAME])
2345 		return -EINVAL;
2346 
2347 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2348 
2349 	if (strcmp(name, tipc_bclink_name) == 0)
2350 		return tipc_nl_bc_link_set(net, attrs);
2351 
2352 	node = tipc_node_find_by_name(net, name, &bearer_id);
2353 	if (!node)
2354 		return -EINVAL;
2355 
2356 	tipc_node_read_lock(node);
2357 
2358 	link = node->links[bearer_id].link;
2359 	if (!link) {
2360 		res = -EINVAL;
2361 		goto out;
2362 	}
2363 
2364 	if (attrs[TIPC_NLA_LINK_PROP]) {
2365 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2366 
2367 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
2368 		if (err) {
2369 			res = err;
2370 			goto out;
2371 		}
2372 
2373 		if (props[TIPC_NLA_PROP_TOL]) {
2374 			u32 tol;
2375 
2376 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2377 			tipc_link_set_tolerance(link, tol, &xmitq);
2378 		}
2379 		if (props[TIPC_NLA_PROP_PRIO]) {
2380 			u32 prio;
2381 
2382 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2383 			tipc_link_set_prio(link, prio, &xmitq);
2384 		}
2385 		if (props[TIPC_NLA_PROP_WIN]) {
2386 			u32 max_win;
2387 
2388 			max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2389 			tipc_link_set_queue_limits(link,
2390 						   tipc_link_min_win(link),
2391 						   max_win);
2392 		}
2393 	}
2394 
2395 out:
2396 	tipc_node_read_unlock(node);
2397 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
2398 			 NULL);
2399 	return res;
2400 }
2401 
2402 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2403 {
2404 	struct net *net = genl_info_net(info);
2405 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2406 	struct tipc_nl_msg msg;
2407 	char *name;
2408 	int err;
2409 
2410 	msg.portid = info->snd_portid;
2411 	msg.seq = info->snd_seq;
2412 
2413 	if (!info->attrs[TIPC_NLA_LINK])
2414 		return -EINVAL;
2415 
2416 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2417 					  info->attrs[TIPC_NLA_LINK],
2418 					  tipc_nl_link_policy, info->extack);
2419 	if (err)
2420 		return err;
2421 
2422 	if (!attrs[TIPC_NLA_LINK_NAME])
2423 		return -EINVAL;
2424 
2425 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2426 
2427 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2428 	if (!msg.skb)
2429 		return -ENOMEM;
2430 
2431 	if (strcmp(name, tipc_bclink_name) == 0) {
2432 		err = tipc_nl_add_bc_link(net, &msg);
2433 		if (err)
2434 			goto err_free;
2435 	} else {
2436 		int bearer_id;
2437 		struct tipc_node *node;
2438 		struct tipc_link *link;
2439 
2440 		node = tipc_node_find_by_name(net, name, &bearer_id);
2441 		if (!node) {
2442 			err = -EINVAL;
2443 			goto err_free;
2444 		}
2445 
2446 		tipc_node_read_lock(node);
2447 		link = node->links[bearer_id].link;
2448 		if (!link) {
2449 			tipc_node_read_unlock(node);
2450 			err = -EINVAL;
2451 			goto err_free;
2452 		}
2453 
2454 		err = __tipc_nl_add_link(net, &msg, link, 0);
2455 		tipc_node_read_unlock(node);
2456 		if (err)
2457 			goto err_free;
2458 	}
2459 
2460 	return genlmsg_reply(msg.skb, info);
2461 
2462 err_free:
2463 	nlmsg_free(msg.skb);
2464 	return err;
2465 }
2466 
2467 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2468 {
2469 	int err;
2470 	char *link_name;
2471 	unsigned int bearer_id;
2472 	struct tipc_link *link;
2473 	struct tipc_node *node;
2474 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2475 	struct net *net = sock_net(skb->sk);
2476 	struct tipc_link_entry *le;
2477 
2478 	if (!info->attrs[TIPC_NLA_LINK])
2479 		return -EINVAL;
2480 
2481 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2482 					  info->attrs[TIPC_NLA_LINK],
2483 					  tipc_nl_link_policy, info->extack);
2484 	if (err)
2485 		return err;
2486 
2487 	if (!attrs[TIPC_NLA_LINK_NAME])
2488 		return -EINVAL;
2489 
2490 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2491 
2492 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2493 		err = tipc_bclink_reset_stats(net);
2494 		if (err)
2495 			return err;
2496 		return 0;
2497 	}
2498 
2499 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2500 	if (!node)
2501 		return -EINVAL;
2502 
2503 	le = &node->links[bearer_id];
2504 	tipc_node_read_lock(node);
2505 	spin_lock_bh(&le->lock);
2506 	link = node->links[bearer_id].link;
2507 	if (!link) {
2508 		spin_unlock_bh(&le->lock);
2509 		tipc_node_read_unlock(node);
2510 		return -EINVAL;
2511 	}
2512 	tipc_link_reset_stats(link);
2513 	spin_unlock_bh(&le->lock);
2514 	tipc_node_read_unlock(node);
2515 	return 0;
2516 }
2517 
2518 /* Caller should hold node lock  */
2519 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2520 				    struct tipc_node *node, u32 *prev_link)
2521 {
2522 	u32 i;
2523 	int err;
2524 
2525 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2526 		*prev_link = i;
2527 
2528 		if (!node->links[i].link)
2529 			continue;
2530 
2531 		err = __tipc_nl_add_link(net, msg,
2532 					 node->links[i].link, NLM_F_MULTI);
2533 		if (err)
2534 			return err;
2535 	}
2536 	*prev_link = 0;
2537 
2538 	return 0;
2539 }
2540 
2541 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2542 {
2543 	struct net *net = sock_net(skb->sk);
2544 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2545 	struct tipc_node *node;
2546 	struct tipc_nl_msg msg;
2547 	u32 prev_node = cb->args[0];
2548 	u32 prev_link = cb->args[1];
2549 	int done = cb->args[2];
2550 	int err;
2551 
2552 	if (done)
2553 		return 0;
2554 
2555 	msg.skb = skb;
2556 	msg.portid = NETLINK_CB(cb->skb).portid;
2557 	msg.seq = cb->nlh->nlmsg_seq;
2558 
2559 	rcu_read_lock();
2560 	if (prev_node) {
2561 		node = tipc_node_find(net, prev_node);
2562 		if (!node) {
2563 			/* We never set seq or call nl_dump_check_consistent()
2564 			 * this means that setting prev_seq here will cause the
2565 			 * consistence check to fail in the netlink callback
2566 			 * handler. Resulting in the last NLMSG_DONE message
2567 			 * having the NLM_F_DUMP_INTR flag set.
2568 			 */
2569 			cb->prev_seq = 1;
2570 			goto out;
2571 		}
2572 		tipc_node_put(node);
2573 
2574 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2575 						 list) {
2576 			tipc_node_read_lock(node);
2577 			err = __tipc_nl_add_node_links(net, &msg, node,
2578 						       &prev_link);
2579 			tipc_node_read_unlock(node);
2580 			if (err)
2581 				goto out;
2582 
2583 			prev_node = node->addr;
2584 		}
2585 	} else {
2586 		err = tipc_nl_add_bc_link(net, &msg);
2587 		if (err)
2588 			goto out;
2589 
2590 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2591 			tipc_node_read_lock(node);
2592 			err = __tipc_nl_add_node_links(net, &msg, node,
2593 						       &prev_link);
2594 			tipc_node_read_unlock(node);
2595 			if (err)
2596 				goto out;
2597 
2598 			prev_node = node->addr;
2599 		}
2600 	}
2601 	done = 1;
2602 out:
2603 	rcu_read_unlock();
2604 
2605 	cb->args[0] = prev_node;
2606 	cb->args[1] = prev_link;
2607 	cb->args[2] = done;
2608 
2609 	return skb->len;
2610 }
2611 
2612 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2613 {
2614 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2615 	struct net *net = sock_net(skb->sk);
2616 	int err;
2617 
2618 	if (!info->attrs[TIPC_NLA_MON])
2619 		return -EINVAL;
2620 
2621 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2622 					  info->attrs[TIPC_NLA_MON],
2623 					  tipc_nl_monitor_policy,
2624 					  info->extack);
2625 	if (err)
2626 		return err;
2627 
2628 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2629 		u32 val;
2630 
2631 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2632 		err = tipc_nl_monitor_set_threshold(net, val);
2633 		if (err)
2634 			return err;
2635 	}
2636 
2637 	return 0;
2638 }
2639 
2640 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2641 {
2642 	struct nlattr *attrs;
2643 	void *hdr;
2644 	u32 val;
2645 
2646 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2647 			  0, TIPC_NL_MON_GET);
2648 	if (!hdr)
2649 		return -EMSGSIZE;
2650 
2651 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2652 	if (!attrs)
2653 		goto msg_full;
2654 
2655 	val = tipc_nl_monitor_get_threshold(net);
2656 
2657 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2658 		goto attr_msg_full;
2659 
2660 	nla_nest_end(msg->skb, attrs);
2661 	genlmsg_end(msg->skb, hdr);
2662 
2663 	return 0;
2664 
2665 attr_msg_full:
2666 	nla_nest_cancel(msg->skb, attrs);
2667 msg_full:
2668 	genlmsg_cancel(msg->skb, hdr);
2669 
2670 	return -EMSGSIZE;
2671 }
2672 
2673 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2674 {
2675 	struct net *net = sock_net(skb->sk);
2676 	struct tipc_nl_msg msg;
2677 	int err;
2678 
2679 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2680 	if (!msg.skb)
2681 		return -ENOMEM;
2682 	msg.portid = info->snd_portid;
2683 	msg.seq = info->snd_seq;
2684 
2685 	err = __tipc_nl_add_monitor_prop(net, &msg);
2686 	if (err) {
2687 		nlmsg_free(msg.skb);
2688 		return err;
2689 	}
2690 
2691 	return genlmsg_reply(msg.skb, info);
2692 }
2693 
2694 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2695 {
2696 	struct net *net = sock_net(skb->sk);
2697 	u32 prev_bearer = cb->args[0];
2698 	struct tipc_nl_msg msg;
2699 	int bearer_id;
2700 	int err;
2701 
2702 	if (prev_bearer == MAX_BEARERS)
2703 		return 0;
2704 
2705 	msg.skb = skb;
2706 	msg.portid = NETLINK_CB(cb->skb).portid;
2707 	msg.seq = cb->nlh->nlmsg_seq;
2708 
2709 	rtnl_lock();
2710 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2711 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2712 		if (err)
2713 			break;
2714 	}
2715 	rtnl_unlock();
2716 	cb->args[0] = bearer_id;
2717 
2718 	return skb->len;
2719 }
2720 
2721 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2722 				   struct netlink_callback *cb)
2723 {
2724 	struct net *net = sock_net(skb->sk);
2725 	u32 prev_node = cb->args[1];
2726 	u32 bearer_id = cb->args[2];
2727 	int done = cb->args[0];
2728 	struct tipc_nl_msg msg;
2729 	int err;
2730 
2731 	if (!prev_node) {
2732 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2733 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2734 
2735 		if (!attrs[TIPC_NLA_MON])
2736 			return -EINVAL;
2737 
2738 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2739 						  attrs[TIPC_NLA_MON],
2740 						  tipc_nl_monitor_policy,
2741 						  NULL);
2742 		if (err)
2743 			return err;
2744 
2745 		if (!mon[TIPC_NLA_MON_REF])
2746 			return -EINVAL;
2747 
2748 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2749 
2750 		if (bearer_id >= MAX_BEARERS)
2751 			return -EINVAL;
2752 	}
2753 
2754 	if (done)
2755 		return 0;
2756 
2757 	msg.skb = skb;
2758 	msg.portid = NETLINK_CB(cb->skb).portid;
2759 	msg.seq = cb->nlh->nlmsg_seq;
2760 
2761 	rtnl_lock();
2762 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2763 	if (!err)
2764 		done = 1;
2765 
2766 	rtnl_unlock();
2767 	cb->args[0] = done;
2768 	cb->args[1] = prev_node;
2769 	cb->args[2] = bearer_id;
2770 
2771 	return skb->len;
2772 }
2773 
2774 #ifdef CONFIG_TIPC_CRYPTO
2775 static int tipc_nl_retrieve_key(struct nlattr **attrs,
2776 				struct tipc_aead_key **key)
2777 {
2778 	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
2779 
2780 	if (!attr)
2781 		return -ENODATA;
2782 
2783 	*key = (struct tipc_aead_key *)nla_data(attr);
2784 	if (nla_len(attr) < tipc_aead_key_size(*key))
2785 		return -EINVAL;
2786 
2787 	return 0;
2788 }
2789 
2790 static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
2791 {
2792 	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
2793 
2794 	if (!attr)
2795 		return -ENODATA;
2796 
2797 	if (nla_len(attr) < TIPC_NODEID_LEN)
2798 		return -EINVAL;
2799 
2800 	*node_id = (u8 *)nla_data(attr);
2801 	return 0;
2802 }
2803 
2804 static int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2805 {
2806 	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
2807 	struct net *net = sock_net(skb->sk);
2808 	struct tipc_net *tn = tipc_net(net);
2809 	struct tipc_node *n = NULL;
2810 	struct tipc_aead_key *ukey;
2811 	struct tipc_crypto *c;
2812 	u8 *id, *own_id;
2813 	int rc = 0;
2814 
2815 	if (!info->attrs[TIPC_NLA_NODE])
2816 		return -EINVAL;
2817 
2818 	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
2819 			      info->attrs[TIPC_NLA_NODE],
2820 			      tipc_nl_node_policy, info->extack);
2821 	if (rc)
2822 		goto exit;
2823 
2824 	own_id = tipc_own_id(net);
2825 	if (!own_id) {
2826 		rc = -EPERM;
2827 		goto exit;
2828 	}
2829 
2830 	rc = tipc_nl_retrieve_key(attrs, &ukey);
2831 	if (rc)
2832 		goto exit;
2833 
2834 	rc = tipc_aead_key_validate(ukey);
2835 	if (rc)
2836 		goto exit;
2837 
2838 	rc = tipc_nl_retrieve_nodeid(attrs, &id);
2839 	switch (rc) {
2840 	case -ENODATA:
2841 		/* Cluster key mode */
2842 		rc = tipc_crypto_key_init(tn->crypto_tx, ukey, CLUSTER_KEY);
2843 		break;
2844 	case 0:
2845 		/* Per-node key mode */
2846 		if (!memcmp(id, own_id, NODE_ID_LEN)) {
2847 			c = tn->crypto_tx;
2848 		} else {
2849 			n = tipc_node_find_by_id(net, id) ?:
2850 				tipc_node_create(net, 0, id, 0xffffu, 0, true);
2851 			if (unlikely(!n)) {
2852 				rc = -ENOMEM;
2853 				break;
2854 			}
2855 			c = n->crypto_rx;
2856 		}
2857 
2858 		rc = tipc_crypto_key_init(c, ukey, PER_NODE_KEY);
2859 		if (n)
2860 			tipc_node_put(n);
2861 		break;
2862 	default:
2863 		break;
2864 	}
2865 
2866 exit:
2867 	return (rc < 0) ? rc : 0;
2868 }
2869 
2870 int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2871 {
2872 	int err;
2873 
2874 	rtnl_lock();
2875 	err = __tipc_nl_node_set_key(skb, info);
2876 	rtnl_unlock();
2877 
2878 	return err;
2879 }
2880 
2881 static int __tipc_nl_node_flush_key(struct sk_buff *skb,
2882 				    struct genl_info *info)
2883 {
2884 	struct net *net = sock_net(skb->sk);
2885 	struct tipc_net *tn = tipc_net(net);
2886 	struct tipc_node *n;
2887 
2888 	tipc_crypto_key_flush(tn->crypto_tx);
2889 	rcu_read_lock();
2890 	list_for_each_entry_rcu(n, &tn->node_list, list)
2891 		tipc_crypto_key_flush(n->crypto_rx);
2892 	rcu_read_unlock();
2893 
2894 	pr_info("All keys are flushed!\n");
2895 	return 0;
2896 }
2897 
2898 int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
2899 {
2900 	int err;
2901 
2902 	rtnl_lock();
2903 	err = __tipc_nl_node_flush_key(skb, info);
2904 	rtnl_unlock();
2905 
2906 	return err;
2907 }
2908 #endif
2909 
2910 /**
2911  * tipc_node_dump - dump TIPC node data
2912  * @n: tipc node to be dumped
2913  * @more: dump more?
2914  *        - false: dump only tipc node data
2915  *        - true: dump node link data as well
2916  * @buf: returned buffer of dump data in format
2917  */
2918 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2919 {
2920 	int i = 0;
2921 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2922 
2923 	if (!n) {
2924 		i += scnprintf(buf, sz, "node data: (null)\n");
2925 		return i;
2926 	}
2927 
2928 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2929 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2930 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2931 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2932 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
2933 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
2934 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
2935 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
2936 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
2937 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
2938 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
2939 
2940 	if (!more)
2941 		return i;
2942 
2943 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
2944 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
2945 	i += scnprintf(buf + i, sz - i, " media: ");
2946 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
2947 	i += scnprintf(buf + i, sz - i, "\n");
2948 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
2949 	i += scnprintf(buf + i, sz - i, " inputq: ");
2950 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
2951 
2952 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
2953 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
2954 	i += scnprintf(buf + i, sz - i, " media: ");
2955 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
2956 	i += scnprintf(buf + i, sz - i, "\n");
2957 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
2958 	i += scnprintf(buf + i, sz - i, " inputq: ");
2959 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
2960 
2961 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
2962 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
2963 
2964 	return i;
2965 }
2966 
2967 void tipc_node_pre_cleanup_net(struct net *exit_net)
2968 {
2969 	struct tipc_node *n;
2970 	struct tipc_net *tn;
2971 	struct net *tmp;
2972 
2973 	rcu_read_lock();
2974 	for_each_net_rcu(tmp) {
2975 		if (tmp == exit_net)
2976 			continue;
2977 		tn = tipc_net(tmp);
2978 		if (!tn)
2979 			continue;
2980 		spin_lock_bh(&tn->node_list_lock);
2981 		list_for_each_entry_rcu(n, &tn->node_list, list) {
2982 			if (!n->peer_net)
2983 				continue;
2984 			if (n->peer_net != exit_net)
2985 				continue;
2986 			tipc_node_write_lock(n);
2987 			n->peer_net = NULL;
2988 			n->peer_hash_mix = 0;
2989 			tipc_node_write_unlock_fast(n);
2990 			break;
2991 		}
2992 		spin_unlock_bh(&tn->node_list_lock);
2993 	}
2994 	rcu_read_unlock();
2995 }
2996