xref: /linux/net/tipc/node.c (revision c5d3cdad688ed75fb311a3a671eb30ba7106d7d3)
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 	if (!skb)
2042 		return;
2043 
2044 rcv:
2045 #endif
2046 	/* Ensure message is well-formed before touching the header */
2047 	if (unlikely(!tipc_msg_validate(&skb)))
2048 		goto discard;
2049 	__skb_queue_head_init(&xmitq);
2050 	hdr = buf_msg(skb);
2051 	usr = msg_user(hdr);
2052 	bc_ack = msg_bcast_ack(hdr);
2053 
2054 	/* Handle arrival of discovery or broadcast packet */
2055 	if (unlikely(msg_non_seq(hdr))) {
2056 		if (unlikely(usr == LINK_CONFIG))
2057 			return tipc_disc_rcv(net, skb, b);
2058 		else
2059 			return tipc_node_bc_rcv(net, skb, bearer_id);
2060 	}
2061 
2062 	/* Discard unicast link messages destined for another node */
2063 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
2064 		goto discard;
2065 
2066 	/* Locate neighboring node that sent packet */
2067 	n = tipc_node_find(net, msg_prevnode(hdr));
2068 	if (unlikely(!n))
2069 		goto discard;
2070 	le = &n->links[bearer_id];
2071 
2072 	/* Ensure broadcast reception is in synch with peer's send state */
2073 	if (unlikely(usr == LINK_PROTOCOL))
2074 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
2075 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
2076 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
2077 
2078 	/* Receive packet directly if conditions permit */
2079 	tipc_node_read_lock(n);
2080 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
2081 		spin_lock_bh(&le->lock);
2082 		if (le->link) {
2083 			rc = tipc_link_rcv(le->link, skb, &xmitq);
2084 			skb = NULL;
2085 		}
2086 		spin_unlock_bh(&le->lock);
2087 	}
2088 	tipc_node_read_unlock(n);
2089 
2090 	/* Check/update node state before receiving */
2091 	if (unlikely(skb)) {
2092 		if (unlikely(skb_linearize(skb)))
2093 			goto discard;
2094 		tipc_node_write_lock(n);
2095 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
2096 			if (le->link) {
2097 				rc = tipc_link_rcv(le->link, skb, &xmitq);
2098 				skb = NULL;
2099 			}
2100 		}
2101 		tipc_node_write_unlock(n);
2102 	}
2103 
2104 	if (unlikely(rc & TIPC_LINK_UP_EVT))
2105 		tipc_node_link_up(n, bearer_id, &xmitq);
2106 
2107 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
2108 		tipc_node_link_down(n, bearer_id, false);
2109 
2110 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
2111 		tipc_named_rcv(net, &n->bc_entry.namedq);
2112 
2113 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
2114 		tipc_node_mcast_rcv(n);
2115 
2116 	if (!skb_queue_empty(&le->inputq))
2117 		tipc_sk_rcv(net, &le->inputq);
2118 
2119 	if (!skb_queue_empty(&xmitq))
2120 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr, n);
2121 
2122 	tipc_node_put(n);
2123 discard:
2124 	kfree_skb(skb);
2125 }
2126 
2127 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
2128 			      int prop)
2129 {
2130 	struct tipc_net *tn = tipc_net(net);
2131 	int bearer_id = b->identity;
2132 	struct sk_buff_head xmitq;
2133 	struct tipc_link_entry *e;
2134 	struct tipc_node *n;
2135 
2136 	__skb_queue_head_init(&xmitq);
2137 
2138 	rcu_read_lock();
2139 
2140 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2141 		tipc_node_write_lock(n);
2142 		e = &n->links[bearer_id];
2143 		if (e->link) {
2144 			if (prop == TIPC_NLA_PROP_TOL)
2145 				tipc_link_set_tolerance(e->link, b->tolerance,
2146 							&xmitq);
2147 			else if (prop == TIPC_NLA_PROP_MTU)
2148 				tipc_link_set_mtu(e->link, b->mtu);
2149 		}
2150 		tipc_node_write_unlock(n);
2151 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr, NULL);
2152 	}
2153 
2154 	rcu_read_unlock();
2155 }
2156 
2157 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
2158 {
2159 	struct net *net = sock_net(skb->sk);
2160 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2161 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
2162 	struct tipc_node *peer, *temp_node;
2163 	u32 addr;
2164 	int err;
2165 
2166 	/* We identify the peer by its net */
2167 	if (!info->attrs[TIPC_NLA_NET])
2168 		return -EINVAL;
2169 
2170 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_NET_MAX,
2171 					  info->attrs[TIPC_NLA_NET],
2172 					  tipc_nl_net_policy, info->extack);
2173 	if (err)
2174 		return err;
2175 
2176 	if (!attrs[TIPC_NLA_NET_ADDR])
2177 		return -EINVAL;
2178 
2179 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
2180 
2181 	if (in_own_node(net, addr))
2182 		return -ENOTSUPP;
2183 
2184 	spin_lock_bh(&tn->node_list_lock);
2185 	peer = tipc_node_find(net, addr);
2186 	if (!peer) {
2187 		spin_unlock_bh(&tn->node_list_lock);
2188 		return -ENXIO;
2189 	}
2190 
2191 	tipc_node_write_lock(peer);
2192 	if (peer->state != SELF_DOWN_PEER_DOWN &&
2193 	    peer->state != SELF_DOWN_PEER_LEAVING) {
2194 		tipc_node_write_unlock(peer);
2195 		err = -EBUSY;
2196 		goto err_out;
2197 	}
2198 
2199 	tipc_node_clear_links(peer);
2200 	tipc_node_write_unlock(peer);
2201 	tipc_node_delete(peer);
2202 
2203 	/* Calculate cluster capabilities */
2204 	tn->capabilities = TIPC_NODE_CAPABILITIES;
2205 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
2206 		tn->capabilities &= temp_node->capabilities;
2207 	}
2208 	tipc_bcast_toggle_rcast(net, (tn->capabilities & TIPC_BCAST_RCAST));
2209 	err = 0;
2210 err_out:
2211 	tipc_node_put(peer);
2212 	spin_unlock_bh(&tn->node_list_lock);
2213 
2214 	return err;
2215 }
2216 
2217 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
2218 {
2219 	int err;
2220 	struct net *net = sock_net(skb->sk);
2221 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2222 	int done = cb->args[0];
2223 	int last_addr = cb->args[1];
2224 	struct tipc_node *node;
2225 	struct tipc_nl_msg msg;
2226 
2227 	if (done)
2228 		return 0;
2229 
2230 	msg.skb = skb;
2231 	msg.portid = NETLINK_CB(cb->skb).portid;
2232 	msg.seq = cb->nlh->nlmsg_seq;
2233 
2234 	rcu_read_lock();
2235 	if (last_addr) {
2236 		node = tipc_node_find(net, last_addr);
2237 		if (!node) {
2238 			rcu_read_unlock();
2239 			/* We never set seq or call nl_dump_check_consistent()
2240 			 * this means that setting prev_seq here will cause the
2241 			 * consistence check to fail in the netlink callback
2242 			 * handler. Resulting in the NLMSG_DONE message having
2243 			 * the NLM_F_DUMP_INTR flag set if the node state
2244 			 * changed while we released the lock.
2245 			 */
2246 			cb->prev_seq = 1;
2247 			return -EPIPE;
2248 		}
2249 		tipc_node_put(node);
2250 	}
2251 
2252 	list_for_each_entry_rcu(node, &tn->node_list, list) {
2253 		if (node->preliminary)
2254 			continue;
2255 		if (last_addr) {
2256 			if (node->addr == last_addr)
2257 				last_addr = 0;
2258 			else
2259 				continue;
2260 		}
2261 
2262 		tipc_node_read_lock(node);
2263 		err = __tipc_nl_add_node(&msg, node);
2264 		if (err) {
2265 			last_addr = node->addr;
2266 			tipc_node_read_unlock(node);
2267 			goto out;
2268 		}
2269 
2270 		tipc_node_read_unlock(node);
2271 	}
2272 	done = 1;
2273 out:
2274 	cb->args[0] = done;
2275 	cb->args[1] = last_addr;
2276 	rcu_read_unlock();
2277 
2278 	return skb->len;
2279 }
2280 
2281 /* tipc_node_find_by_name - locate owner node of link by link's name
2282  * @net: the applicable net namespace
2283  * @name: pointer to link name string
2284  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2285  *
2286  * Returns pointer to node owning the link, or 0 if no matching link is found.
2287  */
2288 static struct tipc_node *tipc_node_find_by_name(struct net *net,
2289 						const char *link_name,
2290 						unsigned int *bearer_id)
2291 {
2292 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2293 	struct tipc_link *l;
2294 	struct tipc_node *n;
2295 	struct tipc_node *found_node = NULL;
2296 	int i;
2297 
2298 	*bearer_id = 0;
2299 	rcu_read_lock();
2300 	list_for_each_entry_rcu(n, &tn->node_list, list) {
2301 		tipc_node_read_lock(n);
2302 		for (i = 0; i < MAX_BEARERS; i++) {
2303 			l = n->links[i].link;
2304 			if (l && !strcmp(tipc_link_name(l), link_name)) {
2305 				*bearer_id = i;
2306 				found_node = n;
2307 				break;
2308 			}
2309 		}
2310 		tipc_node_read_unlock(n);
2311 		if (found_node)
2312 			break;
2313 	}
2314 	rcu_read_unlock();
2315 
2316 	return found_node;
2317 }
2318 
2319 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
2320 {
2321 	int err;
2322 	int res = 0;
2323 	int bearer_id;
2324 	char *name;
2325 	struct tipc_link *link;
2326 	struct tipc_node *node;
2327 	struct sk_buff_head xmitq;
2328 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2329 	struct net *net = sock_net(skb->sk);
2330 
2331 	__skb_queue_head_init(&xmitq);
2332 
2333 	if (!info->attrs[TIPC_NLA_LINK])
2334 		return -EINVAL;
2335 
2336 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2337 					  info->attrs[TIPC_NLA_LINK],
2338 					  tipc_nl_link_policy, info->extack);
2339 	if (err)
2340 		return err;
2341 
2342 	if (!attrs[TIPC_NLA_LINK_NAME])
2343 		return -EINVAL;
2344 
2345 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2346 
2347 	if (strcmp(name, tipc_bclink_name) == 0)
2348 		return tipc_nl_bc_link_set(net, attrs);
2349 
2350 	node = tipc_node_find_by_name(net, name, &bearer_id);
2351 	if (!node)
2352 		return -EINVAL;
2353 
2354 	tipc_node_read_lock(node);
2355 
2356 	link = node->links[bearer_id].link;
2357 	if (!link) {
2358 		res = -EINVAL;
2359 		goto out;
2360 	}
2361 
2362 	if (attrs[TIPC_NLA_LINK_PROP]) {
2363 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2364 
2365 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
2366 		if (err) {
2367 			res = err;
2368 			goto out;
2369 		}
2370 
2371 		if (props[TIPC_NLA_PROP_TOL]) {
2372 			u32 tol;
2373 
2374 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2375 			tipc_link_set_tolerance(link, tol, &xmitq);
2376 		}
2377 		if (props[TIPC_NLA_PROP_PRIO]) {
2378 			u32 prio;
2379 
2380 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2381 			tipc_link_set_prio(link, prio, &xmitq);
2382 		}
2383 		if (props[TIPC_NLA_PROP_WIN]) {
2384 			u32 max_win;
2385 
2386 			max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2387 			tipc_link_set_queue_limits(link,
2388 						   tipc_link_min_win(link),
2389 						   max_win);
2390 		}
2391 	}
2392 
2393 out:
2394 	tipc_node_read_unlock(node);
2395 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr,
2396 			 NULL);
2397 	return res;
2398 }
2399 
2400 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2401 {
2402 	struct net *net = genl_info_net(info);
2403 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2404 	struct tipc_nl_msg msg;
2405 	char *name;
2406 	int err;
2407 
2408 	msg.portid = info->snd_portid;
2409 	msg.seq = info->snd_seq;
2410 
2411 	if (!info->attrs[TIPC_NLA_LINK])
2412 		return -EINVAL;
2413 
2414 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2415 					  info->attrs[TIPC_NLA_LINK],
2416 					  tipc_nl_link_policy, info->extack);
2417 	if (err)
2418 		return err;
2419 
2420 	if (!attrs[TIPC_NLA_LINK_NAME])
2421 		return -EINVAL;
2422 
2423 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2424 
2425 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2426 	if (!msg.skb)
2427 		return -ENOMEM;
2428 
2429 	if (strcmp(name, tipc_bclink_name) == 0) {
2430 		err = tipc_nl_add_bc_link(net, &msg);
2431 		if (err)
2432 			goto err_free;
2433 	} else {
2434 		int bearer_id;
2435 		struct tipc_node *node;
2436 		struct tipc_link *link;
2437 
2438 		node = tipc_node_find_by_name(net, name, &bearer_id);
2439 		if (!node) {
2440 			err = -EINVAL;
2441 			goto err_free;
2442 		}
2443 
2444 		tipc_node_read_lock(node);
2445 		link = node->links[bearer_id].link;
2446 		if (!link) {
2447 			tipc_node_read_unlock(node);
2448 			err = -EINVAL;
2449 			goto err_free;
2450 		}
2451 
2452 		err = __tipc_nl_add_link(net, &msg, link, 0);
2453 		tipc_node_read_unlock(node);
2454 		if (err)
2455 			goto err_free;
2456 	}
2457 
2458 	return genlmsg_reply(msg.skb, info);
2459 
2460 err_free:
2461 	nlmsg_free(msg.skb);
2462 	return err;
2463 }
2464 
2465 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2466 {
2467 	int err;
2468 	char *link_name;
2469 	unsigned int bearer_id;
2470 	struct tipc_link *link;
2471 	struct tipc_node *node;
2472 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2473 	struct net *net = sock_net(skb->sk);
2474 	struct tipc_link_entry *le;
2475 
2476 	if (!info->attrs[TIPC_NLA_LINK])
2477 		return -EINVAL;
2478 
2479 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_LINK_MAX,
2480 					  info->attrs[TIPC_NLA_LINK],
2481 					  tipc_nl_link_policy, info->extack);
2482 	if (err)
2483 		return err;
2484 
2485 	if (!attrs[TIPC_NLA_LINK_NAME])
2486 		return -EINVAL;
2487 
2488 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2489 
2490 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2491 		err = tipc_bclink_reset_stats(net);
2492 		if (err)
2493 			return err;
2494 		return 0;
2495 	}
2496 
2497 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2498 	if (!node)
2499 		return -EINVAL;
2500 
2501 	le = &node->links[bearer_id];
2502 	tipc_node_read_lock(node);
2503 	spin_lock_bh(&le->lock);
2504 	link = node->links[bearer_id].link;
2505 	if (!link) {
2506 		spin_unlock_bh(&le->lock);
2507 		tipc_node_read_unlock(node);
2508 		return -EINVAL;
2509 	}
2510 	tipc_link_reset_stats(link);
2511 	spin_unlock_bh(&le->lock);
2512 	tipc_node_read_unlock(node);
2513 	return 0;
2514 }
2515 
2516 /* Caller should hold node lock  */
2517 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2518 				    struct tipc_node *node, u32 *prev_link)
2519 {
2520 	u32 i;
2521 	int err;
2522 
2523 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2524 		*prev_link = i;
2525 
2526 		if (!node->links[i].link)
2527 			continue;
2528 
2529 		err = __tipc_nl_add_link(net, msg,
2530 					 node->links[i].link, NLM_F_MULTI);
2531 		if (err)
2532 			return err;
2533 	}
2534 	*prev_link = 0;
2535 
2536 	return 0;
2537 }
2538 
2539 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2540 {
2541 	struct net *net = sock_net(skb->sk);
2542 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2543 	struct tipc_node *node;
2544 	struct tipc_nl_msg msg;
2545 	u32 prev_node = cb->args[0];
2546 	u32 prev_link = cb->args[1];
2547 	int done = cb->args[2];
2548 	int err;
2549 
2550 	if (done)
2551 		return 0;
2552 
2553 	msg.skb = skb;
2554 	msg.portid = NETLINK_CB(cb->skb).portid;
2555 	msg.seq = cb->nlh->nlmsg_seq;
2556 
2557 	rcu_read_lock();
2558 	if (prev_node) {
2559 		node = tipc_node_find(net, prev_node);
2560 		if (!node) {
2561 			/* We never set seq or call nl_dump_check_consistent()
2562 			 * this means that setting prev_seq here will cause the
2563 			 * consistence check to fail in the netlink callback
2564 			 * handler. Resulting in the last NLMSG_DONE message
2565 			 * having the NLM_F_DUMP_INTR flag set.
2566 			 */
2567 			cb->prev_seq = 1;
2568 			goto out;
2569 		}
2570 		tipc_node_put(node);
2571 
2572 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2573 						 list) {
2574 			tipc_node_read_lock(node);
2575 			err = __tipc_nl_add_node_links(net, &msg, node,
2576 						       &prev_link);
2577 			tipc_node_read_unlock(node);
2578 			if (err)
2579 				goto out;
2580 
2581 			prev_node = node->addr;
2582 		}
2583 	} else {
2584 		err = tipc_nl_add_bc_link(net, &msg);
2585 		if (err)
2586 			goto out;
2587 
2588 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2589 			tipc_node_read_lock(node);
2590 			err = __tipc_nl_add_node_links(net, &msg, node,
2591 						       &prev_link);
2592 			tipc_node_read_unlock(node);
2593 			if (err)
2594 				goto out;
2595 
2596 			prev_node = node->addr;
2597 		}
2598 	}
2599 	done = 1;
2600 out:
2601 	rcu_read_unlock();
2602 
2603 	cb->args[0] = prev_node;
2604 	cb->args[1] = prev_link;
2605 	cb->args[2] = done;
2606 
2607 	return skb->len;
2608 }
2609 
2610 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2611 {
2612 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2613 	struct net *net = sock_net(skb->sk);
2614 	int err;
2615 
2616 	if (!info->attrs[TIPC_NLA_MON])
2617 		return -EINVAL;
2618 
2619 	err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MON_MAX,
2620 					  info->attrs[TIPC_NLA_MON],
2621 					  tipc_nl_monitor_policy,
2622 					  info->extack);
2623 	if (err)
2624 		return err;
2625 
2626 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2627 		u32 val;
2628 
2629 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2630 		err = tipc_nl_monitor_set_threshold(net, val);
2631 		if (err)
2632 			return err;
2633 	}
2634 
2635 	return 0;
2636 }
2637 
2638 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2639 {
2640 	struct nlattr *attrs;
2641 	void *hdr;
2642 	u32 val;
2643 
2644 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2645 			  0, TIPC_NL_MON_GET);
2646 	if (!hdr)
2647 		return -EMSGSIZE;
2648 
2649 	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
2650 	if (!attrs)
2651 		goto msg_full;
2652 
2653 	val = tipc_nl_monitor_get_threshold(net);
2654 
2655 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2656 		goto attr_msg_full;
2657 
2658 	nla_nest_end(msg->skb, attrs);
2659 	genlmsg_end(msg->skb, hdr);
2660 
2661 	return 0;
2662 
2663 attr_msg_full:
2664 	nla_nest_cancel(msg->skb, attrs);
2665 msg_full:
2666 	genlmsg_cancel(msg->skb, hdr);
2667 
2668 	return -EMSGSIZE;
2669 }
2670 
2671 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2672 {
2673 	struct net *net = sock_net(skb->sk);
2674 	struct tipc_nl_msg msg;
2675 	int err;
2676 
2677 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2678 	if (!msg.skb)
2679 		return -ENOMEM;
2680 	msg.portid = info->snd_portid;
2681 	msg.seq = info->snd_seq;
2682 
2683 	err = __tipc_nl_add_monitor_prop(net, &msg);
2684 	if (err) {
2685 		nlmsg_free(msg.skb);
2686 		return err;
2687 	}
2688 
2689 	return genlmsg_reply(msg.skb, info);
2690 }
2691 
2692 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2693 {
2694 	struct net *net = sock_net(skb->sk);
2695 	u32 prev_bearer = cb->args[0];
2696 	struct tipc_nl_msg msg;
2697 	int bearer_id;
2698 	int err;
2699 
2700 	if (prev_bearer == MAX_BEARERS)
2701 		return 0;
2702 
2703 	msg.skb = skb;
2704 	msg.portid = NETLINK_CB(cb->skb).portid;
2705 	msg.seq = cb->nlh->nlmsg_seq;
2706 
2707 	rtnl_lock();
2708 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2709 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2710 		if (err)
2711 			break;
2712 	}
2713 	rtnl_unlock();
2714 	cb->args[0] = bearer_id;
2715 
2716 	return skb->len;
2717 }
2718 
2719 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2720 				   struct netlink_callback *cb)
2721 {
2722 	struct net *net = sock_net(skb->sk);
2723 	u32 prev_node = cb->args[1];
2724 	u32 bearer_id = cb->args[2];
2725 	int done = cb->args[0];
2726 	struct tipc_nl_msg msg;
2727 	int err;
2728 
2729 	if (!prev_node) {
2730 		struct nlattr **attrs = genl_dumpit_info(cb)->attrs;
2731 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2732 
2733 		if (!attrs[TIPC_NLA_MON])
2734 			return -EINVAL;
2735 
2736 		err = nla_parse_nested_deprecated(mon, TIPC_NLA_MON_MAX,
2737 						  attrs[TIPC_NLA_MON],
2738 						  tipc_nl_monitor_policy,
2739 						  NULL);
2740 		if (err)
2741 			return err;
2742 
2743 		if (!mon[TIPC_NLA_MON_REF])
2744 			return -EINVAL;
2745 
2746 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2747 
2748 		if (bearer_id >= MAX_BEARERS)
2749 			return -EINVAL;
2750 	}
2751 
2752 	if (done)
2753 		return 0;
2754 
2755 	msg.skb = skb;
2756 	msg.portid = NETLINK_CB(cb->skb).portid;
2757 	msg.seq = cb->nlh->nlmsg_seq;
2758 
2759 	rtnl_lock();
2760 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2761 	if (!err)
2762 		done = 1;
2763 
2764 	rtnl_unlock();
2765 	cb->args[0] = done;
2766 	cb->args[1] = prev_node;
2767 	cb->args[2] = bearer_id;
2768 
2769 	return skb->len;
2770 }
2771 
2772 #ifdef CONFIG_TIPC_CRYPTO
2773 static int tipc_nl_retrieve_key(struct nlattr **attrs,
2774 				struct tipc_aead_key **key)
2775 {
2776 	struct nlattr *attr = attrs[TIPC_NLA_NODE_KEY];
2777 
2778 	if (!attr)
2779 		return -ENODATA;
2780 
2781 	*key = (struct tipc_aead_key *)nla_data(attr);
2782 	if (nla_len(attr) < tipc_aead_key_size(*key))
2783 		return -EINVAL;
2784 
2785 	return 0;
2786 }
2787 
2788 static int tipc_nl_retrieve_nodeid(struct nlattr **attrs, u8 **node_id)
2789 {
2790 	struct nlattr *attr = attrs[TIPC_NLA_NODE_ID];
2791 
2792 	if (!attr)
2793 		return -ENODATA;
2794 
2795 	if (nla_len(attr) < TIPC_NODEID_LEN)
2796 		return -EINVAL;
2797 
2798 	*node_id = (u8 *)nla_data(attr);
2799 	return 0;
2800 }
2801 
2802 static int __tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2803 {
2804 	struct nlattr *attrs[TIPC_NLA_NODE_MAX + 1];
2805 	struct net *net = sock_net(skb->sk);
2806 	struct tipc_net *tn = tipc_net(net);
2807 	struct tipc_node *n = NULL;
2808 	struct tipc_aead_key *ukey;
2809 	struct tipc_crypto *c;
2810 	u8 *id, *own_id;
2811 	int rc = 0;
2812 
2813 	if (!info->attrs[TIPC_NLA_NODE])
2814 		return -EINVAL;
2815 
2816 	rc = nla_parse_nested(attrs, TIPC_NLA_NODE_MAX,
2817 			      info->attrs[TIPC_NLA_NODE],
2818 			      tipc_nl_node_policy, info->extack);
2819 	if (rc)
2820 		goto exit;
2821 
2822 	own_id = tipc_own_id(net);
2823 	if (!own_id) {
2824 		rc = -EPERM;
2825 		goto exit;
2826 	}
2827 
2828 	rc = tipc_nl_retrieve_key(attrs, &ukey);
2829 	if (rc)
2830 		goto exit;
2831 
2832 	rc = tipc_aead_key_validate(ukey);
2833 	if (rc)
2834 		goto exit;
2835 
2836 	rc = tipc_nl_retrieve_nodeid(attrs, &id);
2837 	switch (rc) {
2838 	case -ENODATA:
2839 		/* Cluster key mode */
2840 		rc = tipc_crypto_key_init(tn->crypto_tx, ukey, CLUSTER_KEY);
2841 		break;
2842 	case 0:
2843 		/* Per-node key mode */
2844 		if (!memcmp(id, own_id, NODE_ID_LEN)) {
2845 			c = tn->crypto_tx;
2846 		} else {
2847 			n = tipc_node_find_by_id(net, id) ?:
2848 				tipc_node_create(net, 0, id, 0xffffu, 0, true);
2849 			if (unlikely(!n)) {
2850 				rc = -ENOMEM;
2851 				break;
2852 			}
2853 			c = n->crypto_rx;
2854 		}
2855 
2856 		rc = tipc_crypto_key_init(c, ukey, PER_NODE_KEY);
2857 		if (n)
2858 			tipc_node_put(n);
2859 		break;
2860 	default:
2861 		break;
2862 	}
2863 
2864 exit:
2865 	return (rc < 0) ? rc : 0;
2866 }
2867 
2868 int tipc_nl_node_set_key(struct sk_buff *skb, struct genl_info *info)
2869 {
2870 	int err;
2871 
2872 	rtnl_lock();
2873 	err = __tipc_nl_node_set_key(skb, info);
2874 	rtnl_unlock();
2875 
2876 	return err;
2877 }
2878 
2879 static int __tipc_nl_node_flush_key(struct sk_buff *skb,
2880 				    struct genl_info *info)
2881 {
2882 	struct net *net = sock_net(skb->sk);
2883 	struct tipc_net *tn = tipc_net(net);
2884 	struct tipc_node *n;
2885 
2886 	tipc_crypto_key_flush(tn->crypto_tx);
2887 	rcu_read_lock();
2888 	list_for_each_entry_rcu(n, &tn->node_list, list)
2889 		tipc_crypto_key_flush(n->crypto_rx);
2890 	rcu_read_unlock();
2891 
2892 	pr_info("All keys are flushed!\n");
2893 	return 0;
2894 }
2895 
2896 int tipc_nl_node_flush_key(struct sk_buff *skb, struct genl_info *info)
2897 {
2898 	int err;
2899 
2900 	rtnl_lock();
2901 	err = __tipc_nl_node_flush_key(skb, info);
2902 	rtnl_unlock();
2903 
2904 	return err;
2905 }
2906 #endif
2907 
2908 /**
2909  * tipc_node_dump - dump TIPC node data
2910  * @n: tipc node to be dumped
2911  * @more: dump more?
2912  *        - false: dump only tipc node data
2913  *        - true: dump node link data as well
2914  * @buf: returned buffer of dump data in format
2915  */
2916 int tipc_node_dump(struct tipc_node *n, bool more, char *buf)
2917 {
2918 	int i = 0;
2919 	size_t sz = (more) ? NODE_LMAX : NODE_LMIN;
2920 
2921 	if (!n) {
2922 		i += scnprintf(buf, sz, "node data: (null)\n");
2923 		return i;
2924 	}
2925 
2926 	i += scnprintf(buf, sz, "node data: %x", n->addr);
2927 	i += scnprintf(buf + i, sz - i, " %x", n->state);
2928 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[0]);
2929 	i += scnprintf(buf + i, sz - i, " %d", n->active_links[1]);
2930 	i += scnprintf(buf + i, sz - i, " %x", n->action_flags);
2931 	i += scnprintf(buf + i, sz - i, " %u", n->failover_sent);
2932 	i += scnprintf(buf + i, sz - i, " %u", n->sync_point);
2933 	i += scnprintf(buf + i, sz - i, " %d", n->link_cnt);
2934 	i += scnprintf(buf + i, sz - i, " %u", n->working_links);
2935 	i += scnprintf(buf + i, sz - i, " %x", n->capabilities);
2936 	i += scnprintf(buf + i, sz - i, " %lu\n", n->keepalive_intv);
2937 
2938 	if (!more)
2939 		return i;
2940 
2941 	i += scnprintf(buf + i, sz - i, "link_entry[0]:\n");
2942 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[0].mtu);
2943 	i += scnprintf(buf + i, sz - i, " media: ");
2944 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[0].maddr);
2945 	i += scnprintf(buf + i, sz - i, "\n");
2946 	i += tipc_link_dump(n->links[0].link, TIPC_DUMP_NONE, buf + i);
2947 	i += scnprintf(buf + i, sz - i, " inputq: ");
2948 	i += tipc_list_dump(&n->links[0].inputq, false, buf + i);
2949 
2950 	i += scnprintf(buf + i, sz - i, "link_entry[1]:\n");
2951 	i += scnprintf(buf + i, sz - i, " mtu: %u\n", n->links[1].mtu);
2952 	i += scnprintf(buf + i, sz - i, " media: ");
2953 	i += tipc_media_addr_printf(buf + i, sz - i, &n->links[1].maddr);
2954 	i += scnprintf(buf + i, sz - i, "\n");
2955 	i += tipc_link_dump(n->links[1].link, TIPC_DUMP_NONE, buf + i);
2956 	i += scnprintf(buf + i, sz - i, " inputq: ");
2957 	i += tipc_list_dump(&n->links[1].inputq, false, buf + i);
2958 
2959 	i += scnprintf(buf + i, sz - i, "bclink:\n ");
2960 	i += tipc_link_dump(n->bc_entry.link, TIPC_DUMP_NONE, buf + i);
2961 
2962 	return i;
2963 }
2964 
2965 void tipc_node_pre_cleanup_net(struct net *exit_net)
2966 {
2967 	struct tipc_node *n;
2968 	struct tipc_net *tn;
2969 	struct net *tmp;
2970 
2971 	rcu_read_lock();
2972 	for_each_net_rcu(tmp) {
2973 		if (tmp == exit_net)
2974 			continue;
2975 		tn = tipc_net(tmp);
2976 		if (!tn)
2977 			continue;
2978 		spin_lock_bh(&tn->node_list_lock);
2979 		list_for_each_entry_rcu(n, &tn->node_list, list) {
2980 			if (!n->peer_net)
2981 				continue;
2982 			if (n->peer_net != exit_net)
2983 				continue;
2984 			tipc_node_write_lock(n);
2985 			n->peer_net = NULL;
2986 			n->peer_hash_mix = 0;
2987 			tipc_node_write_unlock_fast(n);
2988 			break;
2989 		}
2990 		spin_unlock_bh(&tn->node_list_lock);
2991 	}
2992 	rcu_read_unlock();
2993 }
2994