xref: /openbmc/linux/net/tipc/node.c (revision fed8b7e366e7c8f81e957ef91aa8f0a38e038c66)
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 
47 #define INVALID_NODE_SIG	0x10000
48 #define NODE_CLEANUP_AFTER	300000
49 
50 /* Flags used to take different actions according to flag type
51  * TIPC_NOTIFY_NODE_DOWN: notify node is down
52  * TIPC_NOTIFY_NODE_UP: notify node is up
53  * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
54  */
55 enum {
56 	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
57 	TIPC_NOTIFY_NODE_UP		= (1 << 4),
58 	TIPC_NOTIFY_LINK_UP		= (1 << 6),
59 	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
60 };
61 
62 struct tipc_link_entry {
63 	struct tipc_link *link;
64 	spinlock_t lock; /* per link */
65 	u32 mtu;
66 	struct sk_buff_head inputq;
67 	struct tipc_media_addr maddr;
68 };
69 
70 struct tipc_bclink_entry {
71 	struct tipc_link *link;
72 	struct sk_buff_head inputq1;
73 	struct sk_buff_head arrvq;
74 	struct sk_buff_head inputq2;
75 	struct sk_buff_head namedq;
76 };
77 
78 /**
79  * struct tipc_node - TIPC node structure
80  * @addr: network address of node
81  * @ref: reference counter to node object
82  * @lock: rwlock governing access to structure
83  * @net: the applicable net namespace
84  * @hash: links to adjacent nodes in unsorted hash chain
85  * @inputq: pointer to input queue containing messages for msg event
86  * @namedq: pointer to name table input queue with name table messages
87  * @active_links: bearer ids of active links, used as index into links[] array
88  * @links: array containing references to all links to node
89  * @action_flags: bit mask of different types of node actions
90  * @state: connectivity state vs peer node
91  * @sync_point: sequence number where synch/failover is finished
92  * @list: links to adjacent nodes in sorted list of cluster's nodes
93  * @working_links: number of working links to node (both active and standby)
94  * @link_cnt: number of links to node
95  * @capabilities: bitmap, indicating peer node's functional capabilities
96  * @signature: node instance identifier
97  * @link_id: local and remote bearer ids of changing link, if any
98  * @publ_list: list of publications
99  * @rcu: rcu struct for tipc_node
100  * @delete_at: indicates the time for deleting a down node
101  */
102 struct tipc_node {
103 	u32 addr;
104 	struct kref kref;
105 	rwlock_t lock;
106 	struct net *net;
107 	struct hlist_node hash;
108 	int active_links[2];
109 	struct tipc_link_entry links[MAX_BEARERS];
110 	struct tipc_bclink_entry bc_entry;
111 	int action_flags;
112 	struct list_head list;
113 	int state;
114 	bool failover_sent;
115 	u16 sync_point;
116 	int link_cnt;
117 	u16 working_links;
118 	u16 capabilities;
119 	u32 signature;
120 	u32 link_id;
121 	u8 peer_id[16];
122 	struct list_head publ_list;
123 	struct list_head conn_sks;
124 	unsigned long keepalive_intv;
125 	struct timer_list timer;
126 	struct rcu_head rcu;
127 	unsigned long delete_at;
128 };
129 
130 /* Node FSM states and events:
131  */
132 enum {
133 	SELF_DOWN_PEER_DOWN    = 0xdd,
134 	SELF_UP_PEER_UP        = 0xaa,
135 	SELF_DOWN_PEER_LEAVING = 0xd1,
136 	SELF_UP_PEER_COMING    = 0xac,
137 	SELF_COMING_PEER_UP    = 0xca,
138 	SELF_LEAVING_PEER_DOWN = 0x1d,
139 	NODE_FAILINGOVER       = 0xf0,
140 	NODE_SYNCHING          = 0xcc
141 };
142 
143 enum {
144 	SELF_ESTABL_CONTACT_EVT = 0xece,
145 	SELF_LOST_CONTACT_EVT   = 0x1ce,
146 	PEER_ESTABL_CONTACT_EVT = 0x9ece,
147 	PEER_LOST_CONTACT_EVT   = 0x91ce,
148 	NODE_FAILOVER_BEGIN_EVT = 0xfbe,
149 	NODE_FAILOVER_END_EVT   = 0xfee,
150 	NODE_SYNCH_BEGIN_EVT    = 0xcbe,
151 	NODE_SYNCH_END_EVT      = 0xcee
152 };
153 
154 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
155 				  struct sk_buff_head *xmitq,
156 				  struct tipc_media_addr **maddr);
157 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
158 				bool delete);
159 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
160 static void tipc_node_delete(struct tipc_node *node);
161 static void tipc_node_timeout(struct timer_list *t);
162 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
163 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
164 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id);
165 static void tipc_node_put(struct tipc_node *node);
166 static bool node_is_up(struct tipc_node *n);
167 static void tipc_node_delete_from_list(struct tipc_node *node);
168 
169 struct tipc_sock_conn {
170 	u32 port;
171 	u32 peer_port;
172 	u32 peer_node;
173 	struct list_head list;
174 };
175 
176 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
177 {
178 	int bearer_id = n->active_links[sel & 1];
179 
180 	if (unlikely(bearer_id == INVALID_BEARER_ID))
181 		return NULL;
182 
183 	return n->links[bearer_id].link;
184 }
185 
186 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
187 {
188 	struct tipc_node *n;
189 	int bearer_id;
190 	unsigned int mtu = MAX_MSG_SIZE;
191 
192 	n = tipc_node_find(net, addr);
193 	if (unlikely(!n))
194 		return mtu;
195 
196 	bearer_id = n->active_links[sel & 1];
197 	if (likely(bearer_id != INVALID_BEARER_ID))
198 		mtu = n->links[bearer_id].mtu;
199 	tipc_node_put(n);
200 	return mtu;
201 }
202 
203 bool tipc_node_get_id(struct net *net, u32 addr, u8 *id)
204 {
205 	u8 *own_id = tipc_own_id(net);
206 	struct tipc_node *n;
207 
208 	if (!own_id)
209 		return true;
210 
211 	if (addr == tipc_own_addr(net)) {
212 		memcpy(id, own_id, TIPC_NODEID_LEN);
213 		return true;
214 	}
215 	n = tipc_node_find(net, addr);
216 	if (!n)
217 		return false;
218 
219 	memcpy(id, &n->peer_id, TIPC_NODEID_LEN);
220 	tipc_node_put(n);
221 	return true;
222 }
223 
224 u16 tipc_node_get_capabilities(struct net *net, u32 addr)
225 {
226 	struct tipc_node *n;
227 	u16 caps;
228 
229 	n = tipc_node_find(net, addr);
230 	if (unlikely(!n))
231 		return TIPC_NODE_CAPABILITIES;
232 	caps = n->capabilities;
233 	tipc_node_put(n);
234 	return caps;
235 }
236 
237 static void tipc_node_kref_release(struct kref *kref)
238 {
239 	struct tipc_node *n = container_of(kref, struct tipc_node, kref);
240 
241 	kfree(n->bc_entry.link);
242 	kfree_rcu(n, rcu);
243 }
244 
245 static void tipc_node_put(struct tipc_node *node)
246 {
247 	kref_put(&node->kref, tipc_node_kref_release);
248 }
249 
250 static void tipc_node_get(struct tipc_node *node)
251 {
252 	kref_get(&node->kref);
253 }
254 
255 /*
256  * tipc_node_find - locate specified node object, if it exists
257  */
258 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
259 {
260 	struct tipc_net *tn = tipc_net(net);
261 	struct tipc_node *node;
262 	unsigned int thash = tipc_hashfn(addr);
263 
264 	rcu_read_lock();
265 	hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
266 		if (node->addr != addr)
267 			continue;
268 		if (!kref_get_unless_zero(&node->kref))
269 			node = NULL;
270 		break;
271 	}
272 	rcu_read_unlock();
273 	return node;
274 }
275 
276 /* tipc_node_find_by_id - locate specified node object by its 128-bit id
277  * Note: this function is called only when a discovery request failed
278  * to find the node by its 32-bit id, and is not time critical
279  */
280 static struct tipc_node *tipc_node_find_by_id(struct net *net, u8 *id)
281 {
282 	struct tipc_net *tn = tipc_net(net);
283 	struct tipc_node *n;
284 	bool found = false;
285 
286 	rcu_read_lock();
287 	list_for_each_entry_rcu(n, &tn->node_list, list) {
288 		read_lock_bh(&n->lock);
289 		if (!memcmp(id, n->peer_id, 16) &&
290 		    kref_get_unless_zero(&n->kref))
291 			found = true;
292 		read_unlock_bh(&n->lock);
293 		if (found)
294 			break;
295 	}
296 	rcu_read_unlock();
297 	return found ? n : NULL;
298 }
299 
300 static void tipc_node_read_lock(struct tipc_node *n)
301 {
302 	read_lock_bh(&n->lock);
303 }
304 
305 static void tipc_node_read_unlock(struct tipc_node *n)
306 {
307 	read_unlock_bh(&n->lock);
308 }
309 
310 static void tipc_node_write_lock(struct tipc_node *n)
311 {
312 	write_lock_bh(&n->lock);
313 }
314 
315 static void tipc_node_write_unlock_fast(struct tipc_node *n)
316 {
317 	write_unlock_bh(&n->lock);
318 }
319 
320 static void tipc_node_write_unlock(struct tipc_node *n)
321 {
322 	struct net *net = n->net;
323 	u32 addr = 0;
324 	u32 flags = n->action_flags;
325 	u32 link_id = 0;
326 	u32 bearer_id;
327 	struct list_head *publ_list;
328 
329 	if (likely(!flags)) {
330 		write_unlock_bh(&n->lock);
331 		return;
332 	}
333 
334 	addr = n->addr;
335 	link_id = n->link_id;
336 	bearer_id = link_id & 0xffff;
337 	publ_list = &n->publ_list;
338 
339 	n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
340 			     TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
341 
342 	write_unlock_bh(&n->lock);
343 
344 	if (flags & TIPC_NOTIFY_NODE_DOWN)
345 		tipc_publ_notify(net, publ_list, addr);
346 
347 	if (flags & TIPC_NOTIFY_NODE_UP)
348 		tipc_named_node_up(net, addr);
349 
350 	if (flags & TIPC_NOTIFY_LINK_UP) {
351 		tipc_mon_peer_up(net, addr, bearer_id);
352 		tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
353 				     TIPC_NODE_SCOPE, link_id, link_id);
354 	}
355 	if (flags & TIPC_NOTIFY_LINK_DOWN) {
356 		tipc_mon_peer_down(net, addr, bearer_id);
357 		tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
358 				      addr, link_id);
359 	}
360 }
361 
362 static struct tipc_node *tipc_node_create(struct net *net, u32 addr,
363 					  u8 *peer_id, u16 capabilities)
364 {
365 	struct tipc_net *tn = net_generic(net, tipc_net_id);
366 	struct tipc_node *n, *temp_node;
367 	struct tipc_link *l;
368 	int bearer_id;
369 	int i;
370 
371 	spin_lock_bh(&tn->node_list_lock);
372 	n = tipc_node_find(net, addr);
373 	if (n) {
374 		if (n->capabilities == capabilities)
375 			goto exit;
376 		/* Same node may come back with new capabilities */
377 		write_lock_bh(&n->lock);
378 		n->capabilities = capabilities;
379 		for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
380 			l = n->links[bearer_id].link;
381 			if (l)
382 				tipc_link_update_caps(l, capabilities);
383 		}
384 		write_unlock_bh(&n->lock);
385 		goto exit;
386 	}
387 	n = kzalloc(sizeof(*n), GFP_ATOMIC);
388 	if (!n) {
389 		pr_warn("Node creation failed, no memory\n");
390 		goto exit;
391 	}
392 	n->addr = addr;
393 	memcpy(&n->peer_id, peer_id, 16);
394 	n->net = net;
395 	n->capabilities = capabilities;
396 	kref_init(&n->kref);
397 	rwlock_init(&n->lock);
398 	INIT_HLIST_NODE(&n->hash);
399 	INIT_LIST_HEAD(&n->list);
400 	INIT_LIST_HEAD(&n->publ_list);
401 	INIT_LIST_HEAD(&n->conn_sks);
402 	skb_queue_head_init(&n->bc_entry.namedq);
403 	skb_queue_head_init(&n->bc_entry.inputq1);
404 	__skb_queue_head_init(&n->bc_entry.arrvq);
405 	skb_queue_head_init(&n->bc_entry.inputq2);
406 	for (i = 0; i < MAX_BEARERS; i++)
407 		spin_lock_init(&n->links[i].lock);
408 	n->state = SELF_DOWN_PEER_LEAVING;
409 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
410 	n->signature = INVALID_NODE_SIG;
411 	n->active_links[0] = INVALID_BEARER_ID;
412 	n->active_links[1] = INVALID_BEARER_ID;
413 	if (!tipc_link_bc_create(net, tipc_own_addr(net),
414 				 addr, U16_MAX,
415 				 tipc_link_window(tipc_bc_sndlink(net)),
416 				 n->capabilities,
417 				 &n->bc_entry.inputq1,
418 				 &n->bc_entry.namedq,
419 				 tipc_bc_sndlink(net),
420 				 &n->bc_entry.link)) {
421 		pr_warn("Broadcast rcv link creation failed, no memory\n");
422 		kfree(n);
423 		n = NULL;
424 		goto exit;
425 	}
426 	tipc_node_get(n);
427 	timer_setup(&n->timer, tipc_node_timeout, 0);
428 	n->keepalive_intv = U32_MAX;
429 	hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
430 	list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
431 		if (n->addr < temp_node->addr)
432 			break;
433 	}
434 	list_add_tail_rcu(&n->list, &temp_node->list);
435 exit:
436 	spin_unlock_bh(&tn->node_list_lock);
437 	return n;
438 }
439 
440 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
441 {
442 	unsigned long tol = tipc_link_tolerance(l);
443 	unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
444 
445 	/* Link with lowest tolerance determines timer interval */
446 	if (intv < n->keepalive_intv)
447 		n->keepalive_intv = intv;
448 
449 	/* Ensure link's abort limit corresponds to current tolerance */
450 	tipc_link_set_abort_limit(l, tol / n->keepalive_intv);
451 }
452 
453 static void tipc_node_delete_from_list(struct tipc_node *node)
454 {
455 	list_del_rcu(&node->list);
456 	hlist_del_rcu(&node->hash);
457 	tipc_node_put(node);
458 }
459 
460 static void tipc_node_delete(struct tipc_node *node)
461 {
462 	tipc_node_delete_from_list(node);
463 
464 	del_timer_sync(&node->timer);
465 	tipc_node_put(node);
466 }
467 
468 void tipc_node_stop(struct net *net)
469 {
470 	struct tipc_net *tn = tipc_net(net);
471 	struct tipc_node *node, *t_node;
472 
473 	spin_lock_bh(&tn->node_list_lock);
474 	list_for_each_entry_safe(node, t_node, &tn->node_list, list)
475 		tipc_node_delete(node);
476 	spin_unlock_bh(&tn->node_list_lock);
477 }
478 
479 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
480 {
481 	struct tipc_node *n;
482 
483 	if (in_own_node(net, addr))
484 		return;
485 
486 	n = tipc_node_find(net, addr);
487 	if (!n) {
488 		pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
489 		return;
490 	}
491 	tipc_node_write_lock(n);
492 	list_add_tail(subscr, &n->publ_list);
493 	tipc_node_write_unlock_fast(n);
494 	tipc_node_put(n);
495 }
496 
497 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
498 {
499 	struct tipc_node *n;
500 
501 	if (in_own_node(net, addr))
502 		return;
503 
504 	n = tipc_node_find(net, addr);
505 	if (!n) {
506 		pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
507 		return;
508 	}
509 	tipc_node_write_lock(n);
510 	list_del_init(subscr);
511 	tipc_node_write_unlock_fast(n);
512 	tipc_node_put(n);
513 }
514 
515 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
516 {
517 	struct tipc_node *node;
518 	struct tipc_sock_conn *conn;
519 	int err = 0;
520 
521 	if (in_own_node(net, dnode))
522 		return 0;
523 
524 	node = tipc_node_find(net, dnode);
525 	if (!node) {
526 		pr_warn("Connecting sock to node 0x%x failed\n", dnode);
527 		return -EHOSTUNREACH;
528 	}
529 	conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
530 	if (!conn) {
531 		err = -EHOSTUNREACH;
532 		goto exit;
533 	}
534 	conn->peer_node = dnode;
535 	conn->port = port;
536 	conn->peer_port = peer_port;
537 
538 	tipc_node_write_lock(node);
539 	list_add_tail(&conn->list, &node->conn_sks);
540 	tipc_node_write_unlock(node);
541 exit:
542 	tipc_node_put(node);
543 	return err;
544 }
545 
546 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
547 {
548 	struct tipc_node *node;
549 	struct tipc_sock_conn *conn, *safe;
550 
551 	if (in_own_node(net, dnode))
552 		return;
553 
554 	node = tipc_node_find(net, dnode);
555 	if (!node)
556 		return;
557 
558 	tipc_node_write_lock(node);
559 	list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
560 		if (port != conn->port)
561 			continue;
562 		list_del(&conn->list);
563 		kfree(conn);
564 	}
565 	tipc_node_write_unlock(node);
566 	tipc_node_put(node);
567 }
568 
569 static void  tipc_node_clear_links(struct tipc_node *node)
570 {
571 	int i;
572 
573 	for (i = 0; i < MAX_BEARERS; i++) {
574 		struct tipc_link_entry *le = &node->links[i];
575 
576 		if (le->link) {
577 			kfree(le->link);
578 			le->link = NULL;
579 			node->link_cnt--;
580 		}
581 	}
582 }
583 
584 /* tipc_node_cleanup - delete nodes that does not
585  * have active links for NODE_CLEANUP_AFTER time
586  */
587 static bool tipc_node_cleanup(struct tipc_node *peer)
588 {
589 	struct tipc_net *tn = tipc_net(peer->net);
590 	bool deleted = false;
591 
592 	/* If lock held by tipc_node_stop() the node will be deleted anyway */
593 	if (!spin_trylock_bh(&tn->node_list_lock))
594 		return false;
595 
596 	tipc_node_write_lock(peer);
597 
598 	if (!node_is_up(peer) && time_after(jiffies, peer->delete_at)) {
599 		tipc_node_clear_links(peer);
600 		tipc_node_delete_from_list(peer);
601 		deleted = true;
602 	}
603 	tipc_node_write_unlock(peer);
604 	spin_unlock_bh(&tn->node_list_lock);
605 	return deleted;
606 }
607 
608 /* tipc_node_timeout - handle expiration of node timer
609  */
610 static void tipc_node_timeout(struct timer_list *t)
611 {
612 	struct tipc_node *n = from_timer(n, t, timer);
613 	struct tipc_link_entry *le;
614 	struct sk_buff_head xmitq;
615 	int remains = n->link_cnt;
616 	int bearer_id;
617 	int rc = 0;
618 
619 	if (!node_is_up(n) && tipc_node_cleanup(n)) {
620 		/*Removing the reference of Timer*/
621 		tipc_node_put(n);
622 		return;
623 	}
624 
625 	__skb_queue_head_init(&xmitq);
626 
627 	for (bearer_id = 0; remains && (bearer_id < MAX_BEARERS); bearer_id++) {
628 		tipc_node_read_lock(n);
629 		le = &n->links[bearer_id];
630 		if (le->link) {
631 			spin_lock_bh(&le->lock);
632 			/* Link tolerance may change asynchronously: */
633 			tipc_node_calculate_timer(n, le->link);
634 			rc = tipc_link_timeout(le->link, &xmitq);
635 			spin_unlock_bh(&le->lock);
636 			remains--;
637 		}
638 		tipc_node_read_unlock(n);
639 		tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
640 		if (rc & TIPC_LINK_DOWN_EVT)
641 			tipc_node_link_down(n, bearer_id, false);
642 	}
643 	mod_timer(&n->timer, jiffies + msecs_to_jiffies(n->keepalive_intv));
644 }
645 
646 /**
647  * __tipc_node_link_up - handle addition of link
648  * Node lock must be held by caller
649  * Link becomes active (alone or shared) or standby, depending on its priority.
650  */
651 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
652 				struct sk_buff_head *xmitq)
653 {
654 	int *slot0 = &n->active_links[0];
655 	int *slot1 = &n->active_links[1];
656 	struct tipc_link *ol = node_active_link(n, 0);
657 	struct tipc_link *nl = n->links[bearer_id].link;
658 
659 	if (!nl || tipc_link_is_up(nl))
660 		return;
661 
662 	tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
663 	if (!tipc_link_is_up(nl))
664 		return;
665 
666 	n->working_links++;
667 	n->action_flags |= TIPC_NOTIFY_LINK_UP;
668 	n->link_id = tipc_link_id(nl);
669 
670 	/* Leave room for tunnel header when returning 'mtu' to users: */
671 	n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
672 
673 	tipc_bearer_add_dest(n->net, bearer_id, n->addr);
674 	tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
675 
676 	pr_debug("Established link <%s> on network plane %c\n",
677 		 tipc_link_name(nl), tipc_link_plane(nl));
678 
679 	/* Ensure that a STATE message goes first */
680 	tipc_link_build_state_msg(nl, xmitq);
681 
682 	/* First link? => give it both slots */
683 	if (!ol) {
684 		*slot0 = bearer_id;
685 		*slot1 = bearer_id;
686 		tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
687 		n->failover_sent = false;
688 		n->action_flags |= TIPC_NOTIFY_NODE_UP;
689 		tipc_link_set_active(nl, true);
690 		tipc_bcast_add_peer(n->net, nl, xmitq);
691 		return;
692 	}
693 
694 	/* Second link => redistribute slots */
695 	if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
696 		pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
697 		*slot0 = bearer_id;
698 		*slot1 = bearer_id;
699 		tipc_link_set_active(nl, true);
700 		tipc_link_set_active(ol, false);
701 	} else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
702 		tipc_link_set_active(nl, true);
703 		*slot1 = bearer_id;
704 	} else {
705 		pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
706 	}
707 
708 	/* Prepare synchronization with first link */
709 	tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
710 }
711 
712 /**
713  * tipc_node_link_up - handle addition of link
714  *
715  * Link becomes active (alone or shared) or standby, depending on its priority.
716  */
717 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
718 			      struct sk_buff_head *xmitq)
719 {
720 	struct tipc_media_addr *maddr;
721 
722 	tipc_node_write_lock(n);
723 	__tipc_node_link_up(n, bearer_id, xmitq);
724 	maddr = &n->links[bearer_id].maddr;
725 	tipc_bearer_xmit(n->net, bearer_id, xmitq, maddr);
726 	tipc_node_write_unlock(n);
727 }
728 
729 /**
730  * __tipc_node_link_down - handle loss of link
731  */
732 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
733 				  struct sk_buff_head *xmitq,
734 				  struct tipc_media_addr **maddr)
735 {
736 	struct tipc_link_entry *le = &n->links[*bearer_id];
737 	int *slot0 = &n->active_links[0];
738 	int *slot1 = &n->active_links[1];
739 	int i, highest = 0, prio;
740 	struct tipc_link *l, *_l, *tnl;
741 
742 	l = n->links[*bearer_id].link;
743 	if (!l || tipc_link_is_reset(l))
744 		return;
745 
746 	n->working_links--;
747 	n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
748 	n->link_id = tipc_link_id(l);
749 
750 	tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
751 
752 	pr_debug("Lost link <%s> on network plane %c\n",
753 		 tipc_link_name(l), tipc_link_plane(l));
754 
755 	/* Select new active link if any available */
756 	*slot0 = INVALID_BEARER_ID;
757 	*slot1 = INVALID_BEARER_ID;
758 	for (i = 0; i < MAX_BEARERS; i++) {
759 		_l = n->links[i].link;
760 		if (!_l || !tipc_link_is_up(_l))
761 			continue;
762 		if (_l == l)
763 			continue;
764 		prio = tipc_link_prio(_l);
765 		if (prio < highest)
766 			continue;
767 		if (prio > highest) {
768 			highest = prio;
769 			*slot0 = i;
770 			*slot1 = i;
771 			continue;
772 		}
773 		*slot1 = i;
774 	}
775 
776 	if (!node_is_up(n)) {
777 		if (tipc_link_peer_is_down(l))
778 			tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
779 		tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
780 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
781 		tipc_link_reset(l);
782 		tipc_link_build_reset_msg(l, xmitq);
783 		*maddr = &n->links[*bearer_id].maddr;
784 		node_lost_contact(n, &le->inputq);
785 		tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
786 		return;
787 	}
788 	tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
789 
790 	/* There is still a working link => initiate failover */
791 	*bearer_id = n->active_links[0];
792 	tnl = n->links[*bearer_id].link;
793 	tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
794 	tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
795 	n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
796 	tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
797 	tipc_link_reset(l);
798 	tipc_link_fsm_evt(l, LINK_RESET_EVT);
799 	tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
800 	tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
801 	*maddr = &n->links[*bearer_id].maddr;
802 }
803 
804 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
805 {
806 	struct tipc_link_entry *le = &n->links[bearer_id];
807 	struct tipc_link *l = le->link;
808 	struct tipc_media_addr *maddr;
809 	struct sk_buff_head xmitq;
810 	int old_bearer_id = bearer_id;
811 
812 	if (!l)
813 		return;
814 
815 	__skb_queue_head_init(&xmitq);
816 
817 	tipc_node_write_lock(n);
818 	if (!tipc_link_is_establishing(l)) {
819 		__tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
820 		if (delete) {
821 			kfree(l);
822 			le->link = NULL;
823 			n->link_cnt--;
824 		}
825 	} else {
826 		/* Defuse pending tipc_node_link_up() */
827 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
828 	}
829 	tipc_node_write_unlock(n);
830 	if (delete)
831 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
832 	tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
833 	tipc_sk_rcv(n->net, &le->inputq);
834 }
835 
836 static bool node_is_up(struct tipc_node *n)
837 {
838 	return n->active_links[0] != INVALID_BEARER_ID;
839 }
840 
841 bool tipc_node_is_up(struct net *net, u32 addr)
842 {
843 	struct tipc_node *n;
844 	bool retval = false;
845 
846 	if (in_own_node(net, addr))
847 		return true;
848 
849 	n = tipc_node_find(net, addr);
850 	if (!n)
851 		return false;
852 	retval = node_is_up(n);
853 	tipc_node_put(n);
854 	return retval;
855 }
856 
857 static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
858 {
859 	struct tipc_node *n;
860 
861 	addr ^= tipc_net(net)->random;
862 	while ((n = tipc_node_find(net, addr))) {
863 		tipc_node_put(n);
864 		addr++;
865 	}
866 	return addr;
867 }
868 
869 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
870  * Returns suggested address if any, otherwise 0
871  */
872 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
873 {
874 	struct tipc_net *tn = tipc_net(net);
875 	struct tipc_node *n;
876 
877 	/* Suggest new address if some other peer is using this one */
878 	n = tipc_node_find(net, addr);
879 	if (n) {
880 		if (!memcmp(n->peer_id, id, NODE_ID_LEN))
881 			addr = 0;
882 		tipc_node_put(n);
883 		if (!addr)
884 			return 0;
885 		return tipc_node_suggest_addr(net, addr);
886 	}
887 
888 	/* Suggest previously used address if peer is known */
889 	n = tipc_node_find_by_id(net, id);
890 	if (n) {
891 		addr = n->addr;
892 		tipc_node_put(n);
893 		return addr;
894 	}
895 
896 	/* Even this node may be in conflict */
897 	if (tn->trial_addr == addr)
898 		return tipc_node_suggest_addr(net, addr);
899 
900 	return 0;
901 }
902 
903 void tipc_node_check_dest(struct net *net, u32 addr,
904 			  u8 *peer_id, struct tipc_bearer *b,
905 			  u16 capabilities, u32 signature,
906 			  struct tipc_media_addr *maddr,
907 			  bool *respond, bool *dupl_addr)
908 {
909 	struct tipc_node *n;
910 	struct tipc_link *l;
911 	struct tipc_link_entry *le;
912 	bool addr_match = false;
913 	bool sign_match = false;
914 	bool link_up = false;
915 	bool accept_addr = false;
916 	bool reset = true;
917 	char *if_name;
918 	unsigned long intv;
919 	u16 session;
920 
921 	*dupl_addr = false;
922 	*respond = false;
923 
924 	n = tipc_node_create(net, addr, peer_id, capabilities);
925 	if (!n)
926 		return;
927 
928 	tipc_node_write_lock(n);
929 
930 	le = &n->links[b->identity];
931 
932 	/* Prepare to validate requesting node's signature and media address */
933 	l = le->link;
934 	link_up = l && tipc_link_is_up(l);
935 	addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
936 	sign_match = (signature == n->signature);
937 
938 	/* These three flags give us eight permutations: */
939 
940 	if (sign_match && addr_match && link_up) {
941 		/* All is fine. Do nothing. */
942 		reset = false;
943 	} else if (sign_match && addr_match && !link_up) {
944 		/* Respond. The link will come up in due time */
945 		*respond = true;
946 	} else if (sign_match && !addr_match && link_up) {
947 		/* Peer has changed i/f address without rebooting.
948 		 * If so, the link will reset soon, and the next
949 		 * discovery will be accepted. So we can ignore it.
950 		 * It may also be an cloned or malicious peer having
951 		 * chosen the same node address and signature as an
952 		 * existing one.
953 		 * Ignore requests until the link goes down, if ever.
954 		 */
955 		*dupl_addr = true;
956 	} else if (sign_match && !addr_match && !link_up) {
957 		/* Peer link has changed i/f address without rebooting.
958 		 * It may also be a cloned or malicious peer; we can't
959 		 * distinguish between the two.
960 		 * The signature is correct, so we must accept.
961 		 */
962 		accept_addr = true;
963 		*respond = true;
964 	} else if (!sign_match && addr_match && link_up) {
965 		/* Peer node rebooted. Two possibilities:
966 		 *  - Delayed re-discovery; this link endpoint has already
967 		 *    reset and re-established contact with the peer, before
968 		 *    receiving a discovery message from that node.
969 		 *    (The peer happened to receive one from this node first).
970 		 *  - The peer came back so fast that our side has not
971 		 *    discovered it yet. Probing from this side will soon
972 		 *    reset the link, since there can be no working link
973 		 *    endpoint at the peer end, and the link will re-establish.
974 		 *  Accept the signature, since it comes from a known peer.
975 		 */
976 		n->signature = signature;
977 	} else if (!sign_match && addr_match && !link_up) {
978 		/*  The peer node has rebooted.
979 		 *  Accept signature, since it is a known peer.
980 		 */
981 		n->signature = signature;
982 		*respond = true;
983 	} else if (!sign_match && !addr_match && link_up) {
984 		/* Peer rebooted with new address, or a new/duplicate peer.
985 		 * Ignore until the link goes down, if ever.
986 		 */
987 		*dupl_addr = true;
988 	} else if (!sign_match && !addr_match && !link_up) {
989 		/* Peer rebooted with new address, or it is a new peer.
990 		 * Accept signature and address.
991 		 */
992 		n->signature = signature;
993 		accept_addr = true;
994 		*respond = true;
995 	}
996 
997 	if (!accept_addr)
998 		goto exit;
999 
1000 	/* Now create new link if not already existing */
1001 	if (!l) {
1002 		if (n->link_cnt == 2)
1003 			goto exit;
1004 
1005 		if_name = strchr(b->name, ':') + 1;
1006 		get_random_bytes(&session, sizeof(u16));
1007 		if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
1008 				      b->net_plane, b->mtu, b->priority,
1009 				      b->window, session,
1010 				      tipc_own_addr(net), addr, peer_id,
1011 				      n->capabilities,
1012 				      tipc_bc_sndlink(n->net), n->bc_entry.link,
1013 				      &le->inputq,
1014 				      &n->bc_entry.namedq, &l)) {
1015 			*respond = false;
1016 			goto exit;
1017 		}
1018 		tipc_link_reset(l);
1019 		tipc_link_fsm_evt(l, LINK_RESET_EVT);
1020 		if (n->state == NODE_FAILINGOVER)
1021 			tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
1022 		le->link = l;
1023 		n->link_cnt++;
1024 		tipc_node_calculate_timer(n, l);
1025 		if (n->link_cnt == 1) {
1026 			intv = jiffies + msecs_to_jiffies(n->keepalive_intv);
1027 			if (!mod_timer(&n->timer, intv))
1028 				tipc_node_get(n);
1029 		}
1030 	}
1031 	memcpy(&le->maddr, maddr, sizeof(*maddr));
1032 exit:
1033 	tipc_node_write_unlock(n);
1034 	if (reset && l && !tipc_link_is_reset(l))
1035 		tipc_node_link_down(n, b->identity, false);
1036 	tipc_node_put(n);
1037 }
1038 
1039 void tipc_node_delete_links(struct net *net, int bearer_id)
1040 {
1041 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1042 	struct tipc_node *n;
1043 
1044 	rcu_read_lock();
1045 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1046 		tipc_node_link_down(n, bearer_id, true);
1047 	}
1048 	rcu_read_unlock();
1049 }
1050 
1051 static void tipc_node_reset_links(struct tipc_node *n)
1052 {
1053 	int i;
1054 
1055 	pr_warn("Resetting all links to %x\n", n->addr);
1056 
1057 	for (i = 0; i < MAX_BEARERS; i++) {
1058 		tipc_node_link_down(n, i, false);
1059 	}
1060 }
1061 
1062 /* tipc_node_fsm_evt - node finite state machine
1063  * Determines when contact is allowed with peer node
1064  */
1065 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
1066 {
1067 	int state = n->state;
1068 
1069 	switch (state) {
1070 	case SELF_DOWN_PEER_DOWN:
1071 		switch (evt) {
1072 		case SELF_ESTABL_CONTACT_EVT:
1073 			state = SELF_UP_PEER_COMING;
1074 			break;
1075 		case PEER_ESTABL_CONTACT_EVT:
1076 			state = SELF_COMING_PEER_UP;
1077 			break;
1078 		case SELF_LOST_CONTACT_EVT:
1079 		case PEER_LOST_CONTACT_EVT:
1080 			break;
1081 		case NODE_SYNCH_END_EVT:
1082 		case NODE_SYNCH_BEGIN_EVT:
1083 		case NODE_FAILOVER_BEGIN_EVT:
1084 		case NODE_FAILOVER_END_EVT:
1085 		default:
1086 			goto illegal_evt;
1087 		}
1088 		break;
1089 	case SELF_UP_PEER_UP:
1090 		switch (evt) {
1091 		case SELF_LOST_CONTACT_EVT:
1092 			state = SELF_DOWN_PEER_LEAVING;
1093 			break;
1094 		case PEER_LOST_CONTACT_EVT:
1095 			state = SELF_LEAVING_PEER_DOWN;
1096 			break;
1097 		case NODE_SYNCH_BEGIN_EVT:
1098 			state = NODE_SYNCHING;
1099 			break;
1100 		case NODE_FAILOVER_BEGIN_EVT:
1101 			state = NODE_FAILINGOVER;
1102 			break;
1103 		case SELF_ESTABL_CONTACT_EVT:
1104 		case PEER_ESTABL_CONTACT_EVT:
1105 		case NODE_SYNCH_END_EVT:
1106 		case NODE_FAILOVER_END_EVT:
1107 			break;
1108 		default:
1109 			goto illegal_evt;
1110 		}
1111 		break;
1112 	case SELF_DOWN_PEER_LEAVING:
1113 		switch (evt) {
1114 		case PEER_LOST_CONTACT_EVT:
1115 			state = SELF_DOWN_PEER_DOWN;
1116 			break;
1117 		case SELF_ESTABL_CONTACT_EVT:
1118 		case PEER_ESTABL_CONTACT_EVT:
1119 		case SELF_LOST_CONTACT_EVT:
1120 			break;
1121 		case NODE_SYNCH_END_EVT:
1122 		case NODE_SYNCH_BEGIN_EVT:
1123 		case NODE_FAILOVER_BEGIN_EVT:
1124 		case NODE_FAILOVER_END_EVT:
1125 		default:
1126 			goto illegal_evt;
1127 		}
1128 		break;
1129 	case SELF_UP_PEER_COMING:
1130 		switch (evt) {
1131 		case PEER_ESTABL_CONTACT_EVT:
1132 			state = SELF_UP_PEER_UP;
1133 			break;
1134 		case SELF_LOST_CONTACT_EVT:
1135 			state = SELF_DOWN_PEER_DOWN;
1136 			break;
1137 		case SELF_ESTABL_CONTACT_EVT:
1138 		case PEER_LOST_CONTACT_EVT:
1139 		case NODE_SYNCH_END_EVT:
1140 		case NODE_FAILOVER_BEGIN_EVT:
1141 			break;
1142 		case NODE_SYNCH_BEGIN_EVT:
1143 		case NODE_FAILOVER_END_EVT:
1144 		default:
1145 			goto illegal_evt;
1146 		}
1147 		break;
1148 	case SELF_COMING_PEER_UP:
1149 		switch (evt) {
1150 		case SELF_ESTABL_CONTACT_EVT:
1151 			state = SELF_UP_PEER_UP;
1152 			break;
1153 		case PEER_LOST_CONTACT_EVT:
1154 			state = SELF_DOWN_PEER_DOWN;
1155 			break;
1156 		case SELF_LOST_CONTACT_EVT:
1157 		case PEER_ESTABL_CONTACT_EVT:
1158 			break;
1159 		case NODE_SYNCH_END_EVT:
1160 		case NODE_SYNCH_BEGIN_EVT:
1161 		case NODE_FAILOVER_BEGIN_EVT:
1162 		case NODE_FAILOVER_END_EVT:
1163 		default:
1164 			goto illegal_evt;
1165 		}
1166 		break;
1167 	case SELF_LEAVING_PEER_DOWN:
1168 		switch (evt) {
1169 		case SELF_LOST_CONTACT_EVT:
1170 			state = SELF_DOWN_PEER_DOWN;
1171 			break;
1172 		case SELF_ESTABL_CONTACT_EVT:
1173 		case PEER_ESTABL_CONTACT_EVT:
1174 		case PEER_LOST_CONTACT_EVT:
1175 			break;
1176 		case NODE_SYNCH_END_EVT:
1177 		case NODE_SYNCH_BEGIN_EVT:
1178 		case NODE_FAILOVER_BEGIN_EVT:
1179 		case NODE_FAILOVER_END_EVT:
1180 		default:
1181 			goto illegal_evt;
1182 		}
1183 		break;
1184 	case NODE_FAILINGOVER:
1185 		switch (evt) {
1186 		case SELF_LOST_CONTACT_EVT:
1187 			state = SELF_DOWN_PEER_LEAVING;
1188 			break;
1189 		case PEER_LOST_CONTACT_EVT:
1190 			state = SELF_LEAVING_PEER_DOWN;
1191 			break;
1192 		case NODE_FAILOVER_END_EVT:
1193 			state = SELF_UP_PEER_UP;
1194 			break;
1195 		case NODE_FAILOVER_BEGIN_EVT:
1196 		case SELF_ESTABL_CONTACT_EVT:
1197 		case PEER_ESTABL_CONTACT_EVT:
1198 			break;
1199 		case NODE_SYNCH_BEGIN_EVT:
1200 		case NODE_SYNCH_END_EVT:
1201 		default:
1202 			goto illegal_evt;
1203 		}
1204 		break;
1205 	case NODE_SYNCHING:
1206 		switch (evt) {
1207 		case SELF_LOST_CONTACT_EVT:
1208 			state = SELF_DOWN_PEER_LEAVING;
1209 			break;
1210 		case PEER_LOST_CONTACT_EVT:
1211 			state = SELF_LEAVING_PEER_DOWN;
1212 			break;
1213 		case NODE_SYNCH_END_EVT:
1214 			state = SELF_UP_PEER_UP;
1215 			break;
1216 		case NODE_FAILOVER_BEGIN_EVT:
1217 			state = NODE_FAILINGOVER;
1218 			break;
1219 		case NODE_SYNCH_BEGIN_EVT:
1220 		case SELF_ESTABL_CONTACT_EVT:
1221 		case PEER_ESTABL_CONTACT_EVT:
1222 			break;
1223 		case NODE_FAILOVER_END_EVT:
1224 		default:
1225 			goto illegal_evt;
1226 		}
1227 		break;
1228 	default:
1229 		pr_err("Unknown node fsm state %x\n", state);
1230 		break;
1231 	}
1232 	n->state = state;
1233 	return;
1234 
1235 illegal_evt:
1236 	pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1237 }
1238 
1239 static void node_lost_contact(struct tipc_node *n,
1240 			      struct sk_buff_head *inputq)
1241 {
1242 	struct tipc_sock_conn *conn, *safe;
1243 	struct tipc_link *l;
1244 	struct list_head *conns = &n->conn_sks;
1245 	struct sk_buff *skb;
1246 	uint i;
1247 
1248 	pr_debug("Lost contact with %x\n", n->addr);
1249 	n->delete_at = jiffies + msecs_to_jiffies(NODE_CLEANUP_AFTER);
1250 
1251 	/* Clean up broadcast state */
1252 	tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1253 
1254 	/* Abort any ongoing link failover */
1255 	for (i = 0; i < MAX_BEARERS; i++) {
1256 		l = n->links[i].link;
1257 		if (l)
1258 			tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1259 	}
1260 
1261 	/* Notify publications from this node */
1262 	n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1263 
1264 	/* Notify sockets connected to node */
1265 	list_for_each_entry_safe(conn, safe, conns, list) {
1266 		skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1267 				      SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1268 				      conn->peer_node, conn->port,
1269 				      conn->peer_port, TIPC_ERR_NO_NODE);
1270 		if (likely(skb))
1271 			skb_queue_tail(inputq, skb);
1272 		list_del(&conn->list);
1273 		kfree(conn);
1274 	}
1275 }
1276 
1277 /**
1278  * tipc_node_get_linkname - get the name of a link
1279  *
1280  * @bearer_id: id of the bearer
1281  * @node: peer node address
1282  * @linkname: link name output buffer
1283  *
1284  * Returns 0 on success
1285  */
1286 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1287 			   char *linkname, size_t len)
1288 {
1289 	struct tipc_link *link;
1290 	int err = -EINVAL;
1291 	struct tipc_node *node = tipc_node_find(net, addr);
1292 
1293 	if (!node)
1294 		return err;
1295 
1296 	if (bearer_id >= MAX_BEARERS)
1297 		goto exit;
1298 
1299 	tipc_node_read_lock(node);
1300 	link = node->links[bearer_id].link;
1301 	if (link) {
1302 		strncpy(linkname, tipc_link_name(link), len);
1303 		err = 0;
1304 	}
1305 	tipc_node_read_unlock(node);
1306 exit:
1307 	tipc_node_put(node);
1308 	return err;
1309 }
1310 
1311 /* Caller should hold node lock for the passed node */
1312 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1313 {
1314 	void *hdr;
1315 	struct nlattr *attrs;
1316 
1317 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1318 			  NLM_F_MULTI, TIPC_NL_NODE_GET);
1319 	if (!hdr)
1320 		return -EMSGSIZE;
1321 
1322 	attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
1323 	if (!attrs)
1324 		goto msg_full;
1325 
1326 	if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1327 		goto attr_msg_full;
1328 	if (node_is_up(node))
1329 		if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1330 			goto attr_msg_full;
1331 
1332 	nla_nest_end(msg->skb, attrs);
1333 	genlmsg_end(msg->skb, hdr);
1334 
1335 	return 0;
1336 
1337 attr_msg_full:
1338 	nla_nest_cancel(msg->skb, attrs);
1339 msg_full:
1340 	genlmsg_cancel(msg->skb, hdr);
1341 
1342 	return -EMSGSIZE;
1343 }
1344 
1345 /**
1346  * tipc_node_xmit() is the general link level function for message sending
1347  * @net: the applicable net namespace
1348  * @list: chain of buffers containing message
1349  * @dnode: address of destination node
1350  * @selector: a number used for deterministic link selection
1351  * Consumes the buffer chain.
1352  * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1353  */
1354 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1355 		   u32 dnode, int selector)
1356 {
1357 	struct tipc_link_entry *le = NULL;
1358 	struct tipc_node *n;
1359 	struct sk_buff_head xmitq;
1360 	int bearer_id;
1361 	int rc;
1362 
1363 	if (in_own_node(net, dnode)) {
1364 		tipc_sk_rcv(net, list);
1365 		return 0;
1366 	}
1367 
1368 	n = tipc_node_find(net, dnode);
1369 	if (unlikely(!n)) {
1370 		skb_queue_purge(list);
1371 		return -EHOSTUNREACH;
1372 	}
1373 
1374 	tipc_node_read_lock(n);
1375 	bearer_id = n->active_links[selector & 1];
1376 	if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1377 		tipc_node_read_unlock(n);
1378 		tipc_node_put(n);
1379 		skb_queue_purge(list);
1380 		return -EHOSTUNREACH;
1381 	}
1382 
1383 	__skb_queue_head_init(&xmitq);
1384 	le = &n->links[bearer_id];
1385 	spin_lock_bh(&le->lock);
1386 	rc = tipc_link_xmit(le->link, list, &xmitq);
1387 	spin_unlock_bh(&le->lock);
1388 	tipc_node_read_unlock(n);
1389 
1390 	if (unlikely(rc == -ENOBUFS))
1391 		tipc_node_link_down(n, bearer_id, false);
1392 	else
1393 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1394 
1395 	tipc_node_put(n);
1396 
1397 	return rc;
1398 }
1399 
1400 /* tipc_node_xmit_skb(): send single buffer to destination
1401  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1402  * messages, which will not be rejected
1403  * The only exception is datagram messages rerouted after secondary
1404  * lookup, which are rare and safe to dispose of anyway.
1405  */
1406 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1407 		       u32 selector)
1408 {
1409 	struct sk_buff_head head;
1410 
1411 	skb_queue_head_init(&head);
1412 	__skb_queue_tail(&head, skb);
1413 	tipc_node_xmit(net, &head, dnode, selector);
1414 	return 0;
1415 }
1416 
1417 /* tipc_node_distr_xmit(): send single buffer msgs to individual destinations
1418  * Note: this is only for SYSTEM_IMPORTANCE messages, which cannot be rejected
1419  */
1420 int tipc_node_distr_xmit(struct net *net, struct sk_buff_head *xmitq)
1421 {
1422 	struct sk_buff *skb;
1423 	u32 selector, dnode;
1424 
1425 	while ((skb = __skb_dequeue(xmitq))) {
1426 		selector = msg_origport(buf_msg(skb));
1427 		dnode = msg_destnode(buf_msg(skb));
1428 		tipc_node_xmit_skb(net, skb, dnode, selector);
1429 	}
1430 	return 0;
1431 }
1432 
1433 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1434 {
1435 	struct sk_buff *txskb;
1436 	struct tipc_node *n;
1437 	u32 dst;
1438 
1439 	rcu_read_lock();
1440 	list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1441 		dst = n->addr;
1442 		if (in_own_node(net, dst))
1443 			continue;
1444 		if (!node_is_up(n))
1445 			continue;
1446 		txskb = pskb_copy(skb, GFP_ATOMIC);
1447 		if (!txskb)
1448 			break;
1449 		msg_set_destnode(buf_msg(txskb), dst);
1450 		tipc_node_xmit_skb(net, txskb, dst, 0);
1451 	}
1452 	rcu_read_unlock();
1453 
1454 	kfree_skb(skb);
1455 }
1456 
1457 static void tipc_node_mcast_rcv(struct tipc_node *n)
1458 {
1459 	struct tipc_bclink_entry *be = &n->bc_entry;
1460 
1461 	/* 'arrvq' is under inputq2's lock protection */
1462 	spin_lock_bh(&be->inputq2.lock);
1463 	spin_lock_bh(&be->inputq1.lock);
1464 	skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1465 	spin_unlock_bh(&be->inputq1.lock);
1466 	spin_unlock_bh(&be->inputq2.lock);
1467 	tipc_sk_mcast_rcv(n->net, &be->arrvq, &be->inputq2);
1468 }
1469 
1470 static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr,
1471 				  int bearer_id, struct sk_buff_head *xmitq)
1472 {
1473 	struct tipc_link *ucl;
1474 	int rc;
1475 
1476 	rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr);
1477 
1478 	if (rc & TIPC_LINK_DOWN_EVT) {
1479 		tipc_node_reset_links(n);
1480 		return;
1481 	}
1482 
1483 	if (!(rc & TIPC_LINK_SND_STATE))
1484 		return;
1485 
1486 	/* If probe message, a STATE response will be sent anyway */
1487 	if (msg_probe(hdr))
1488 		return;
1489 
1490 	/* Produce a STATE message carrying broadcast NACK */
1491 	tipc_node_read_lock(n);
1492 	ucl = n->links[bearer_id].link;
1493 	if (ucl)
1494 		tipc_link_build_state_msg(ucl, xmitq);
1495 	tipc_node_read_unlock(n);
1496 }
1497 
1498 /**
1499  * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1500  * @net: the applicable net namespace
1501  * @skb: TIPC packet
1502  * @bearer_id: id of bearer message arrived on
1503  *
1504  * Invoked with no locks held.
1505  */
1506 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1507 {
1508 	int rc;
1509 	struct sk_buff_head xmitq;
1510 	struct tipc_bclink_entry *be;
1511 	struct tipc_link_entry *le;
1512 	struct tipc_msg *hdr = buf_msg(skb);
1513 	int usr = msg_user(hdr);
1514 	u32 dnode = msg_destnode(hdr);
1515 	struct tipc_node *n;
1516 
1517 	__skb_queue_head_init(&xmitq);
1518 
1519 	/* If NACK for other node, let rcv link for that node peek into it */
1520 	if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1521 		n = tipc_node_find(net, dnode);
1522 	else
1523 		n = tipc_node_find(net, msg_prevnode(hdr));
1524 	if (!n) {
1525 		kfree_skb(skb);
1526 		return;
1527 	}
1528 	be = &n->bc_entry;
1529 	le = &n->links[bearer_id];
1530 
1531 	rc = tipc_bcast_rcv(net, be->link, skb);
1532 
1533 	/* Broadcast ACKs are sent on a unicast link */
1534 	if (rc & TIPC_LINK_SND_STATE) {
1535 		tipc_node_read_lock(n);
1536 		tipc_link_build_state_msg(le->link, &xmitq);
1537 		tipc_node_read_unlock(n);
1538 	}
1539 
1540 	if (!skb_queue_empty(&xmitq))
1541 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1542 
1543 	if (!skb_queue_empty(&be->inputq1))
1544 		tipc_node_mcast_rcv(n);
1545 
1546 	/* If reassembly or retransmission failure => reset all links to peer */
1547 	if (rc & TIPC_LINK_DOWN_EVT)
1548 		tipc_node_reset_links(n);
1549 
1550 	tipc_node_put(n);
1551 }
1552 
1553 /**
1554  * tipc_node_check_state - check and if necessary update node state
1555  * @skb: TIPC packet
1556  * @bearer_id: identity of bearer delivering the packet
1557  * Returns true if state and msg are ok, otherwise false
1558  */
1559 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1560 				  int bearer_id, struct sk_buff_head *xmitq)
1561 {
1562 	struct tipc_msg *hdr = buf_msg(skb);
1563 	int usr = msg_user(hdr);
1564 	int mtyp = msg_type(hdr);
1565 	u16 oseqno = msg_seqno(hdr);
1566 	u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1567 	u16 exp_pkts = msg_msgcnt(hdr);
1568 	u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1569 	int state = n->state;
1570 	struct tipc_link *l, *tnl, *pl = NULL;
1571 	struct tipc_media_addr *maddr;
1572 	int pb_id;
1573 
1574 	l = n->links[bearer_id].link;
1575 	if (!l)
1576 		return false;
1577 	rcv_nxt = tipc_link_rcv_nxt(l);
1578 
1579 
1580 	if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1581 		return true;
1582 
1583 	/* Find parallel link, if any */
1584 	for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1585 		if ((pb_id != bearer_id) && n->links[pb_id].link) {
1586 			pl = n->links[pb_id].link;
1587 			break;
1588 		}
1589 	}
1590 
1591 	if (!tipc_link_validate_msg(l, hdr))
1592 		return false;
1593 
1594 	/* Check and update node accesibility if applicable */
1595 	if (state == SELF_UP_PEER_COMING) {
1596 		if (!tipc_link_is_up(l))
1597 			return true;
1598 		if (!msg_peer_link_is_up(hdr))
1599 			return true;
1600 		tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1601 	}
1602 
1603 	if (state == SELF_DOWN_PEER_LEAVING) {
1604 		if (msg_peer_node_is_up(hdr))
1605 			return false;
1606 		tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1607 		return true;
1608 	}
1609 
1610 	if (state == SELF_LEAVING_PEER_DOWN)
1611 		return false;
1612 
1613 	/* Ignore duplicate packets */
1614 	if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1615 		return true;
1616 
1617 	/* Initiate or update failover mode if applicable */
1618 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1619 		syncpt = oseqno + exp_pkts - 1;
1620 		if (pl && tipc_link_is_up(pl)) {
1621 			__tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1622 			tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1623 							tipc_link_inputq(l));
1624 		}
1625 		/* If parallel link was already down, and this happened before
1626 		 * the tunnel link came up, FAILOVER was never sent. Ensure that
1627 		 * FAILOVER is sent to get peer out of NODE_FAILINGOVER state.
1628 		 */
1629 		if (n->state != NODE_FAILINGOVER && !n->failover_sent) {
1630 			tipc_link_create_dummy_tnl_msg(l, xmitq);
1631 			n->failover_sent = true;
1632 		}
1633 		/* If pkts arrive out of order, use lowest calculated syncpt */
1634 		if (less(syncpt, n->sync_point))
1635 			n->sync_point = syncpt;
1636 	}
1637 
1638 	/* Open parallel link when tunnel link reaches synch point */
1639 	if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1640 		if (!more(rcv_nxt, n->sync_point))
1641 			return true;
1642 		tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1643 		if (pl)
1644 			tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1645 		return true;
1646 	}
1647 
1648 	/* No synching needed if only one link */
1649 	if (!pl || !tipc_link_is_up(pl))
1650 		return true;
1651 
1652 	/* Initiate synch mode if applicable */
1653 	if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1654 		syncpt = iseqno + exp_pkts - 1;
1655 		if (!tipc_link_is_up(l))
1656 			__tipc_node_link_up(n, bearer_id, xmitq);
1657 		if (n->state == SELF_UP_PEER_UP) {
1658 			n->sync_point = syncpt;
1659 			tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1660 			tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1661 		}
1662 	}
1663 
1664 	/* Open tunnel link when parallel link reaches synch point */
1665 	if (n->state == NODE_SYNCHING) {
1666 		if (tipc_link_is_synching(l)) {
1667 			tnl = l;
1668 		} else {
1669 			tnl = pl;
1670 			pl = l;
1671 		}
1672 		inputq_len = skb_queue_len(tipc_link_inputq(pl));
1673 		dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1674 		if (more(dlv_nxt, n->sync_point)) {
1675 			tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1676 			tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1677 			return true;
1678 		}
1679 		if (l == pl)
1680 			return true;
1681 		if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1682 			return true;
1683 		if (usr == LINK_PROTOCOL)
1684 			return true;
1685 		return false;
1686 	}
1687 	return true;
1688 }
1689 
1690 /**
1691  * tipc_rcv - process TIPC packets/messages arriving from off-node
1692  * @net: the applicable net namespace
1693  * @skb: TIPC packet
1694  * @bearer: pointer to bearer message arrived on
1695  *
1696  * Invoked with no locks held. Bearer pointer must point to a valid bearer
1697  * structure (i.e. cannot be NULL), but bearer can be inactive.
1698  */
1699 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1700 {
1701 	struct sk_buff_head xmitq;
1702 	struct tipc_node *n;
1703 	struct tipc_msg *hdr;
1704 	int bearer_id = b->identity;
1705 	struct tipc_link_entry *le;
1706 	u32 self = tipc_own_addr(net);
1707 	int usr, rc = 0;
1708 	u16 bc_ack;
1709 
1710 	__skb_queue_head_init(&xmitq);
1711 
1712 	/* Ensure message is well-formed before touching the header */
1713 	if (unlikely(!tipc_msg_validate(&skb)))
1714 		goto discard;
1715 	hdr = buf_msg(skb);
1716 	usr = msg_user(hdr);
1717 	bc_ack = msg_bcast_ack(hdr);
1718 
1719 	/* Handle arrival of discovery or broadcast packet */
1720 	if (unlikely(msg_non_seq(hdr))) {
1721 		if (unlikely(usr == LINK_CONFIG))
1722 			return tipc_disc_rcv(net, skb, b);
1723 		else
1724 			return tipc_node_bc_rcv(net, skb, bearer_id);
1725 	}
1726 
1727 	/* Discard unicast link messages destined for another node */
1728 	if (unlikely(!msg_short(hdr) && (msg_destnode(hdr) != self)))
1729 		goto discard;
1730 
1731 	/* Locate neighboring node that sent packet */
1732 	n = tipc_node_find(net, msg_prevnode(hdr));
1733 	if (unlikely(!n))
1734 		goto discard;
1735 	le = &n->links[bearer_id];
1736 
1737 	/* Ensure broadcast reception is in synch with peer's send state */
1738 	if (unlikely(usr == LINK_PROTOCOL))
1739 		tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq);
1740 	else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
1741 		tipc_bcast_ack_rcv(net, n->bc_entry.link, hdr);
1742 
1743 	/* Receive packet directly if conditions permit */
1744 	tipc_node_read_lock(n);
1745 	if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
1746 		spin_lock_bh(&le->lock);
1747 		if (le->link) {
1748 			rc = tipc_link_rcv(le->link, skb, &xmitq);
1749 			skb = NULL;
1750 		}
1751 		spin_unlock_bh(&le->lock);
1752 	}
1753 	tipc_node_read_unlock(n);
1754 
1755 	/* Check/update node state before receiving */
1756 	if (unlikely(skb)) {
1757 		if (unlikely(skb_linearize(skb)))
1758 			goto discard;
1759 		tipc_node_write_lock(n);
1760 		if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
1761 			if (le->link) {
1762 				rc = tipc_link_rcv(le->link, skb, &xmitq);
1763 				skb = NULL;
1764 			}
1765 		}
1766 		tipc_node_write_unlock(n);
1767 	}
1768 
1769 	if (unlikely(rc & TIPC_LINK_UP_EVT))
1770 		tipc_node_link_up(n, bearer_id, &xmitq);
1771 
1772 	if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1773 		tipc_node_link_down(n, bearer_id, false);
1774 
1775 	if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1776 		tipc_named_rcv(net, &n->bc_entry.namedq);
1777 
1778 	if (unlikely(!skb_queue_empty(&n->bc_entry.inputq1)))
1779 		tipc_node_mcast_rcv(n);
1780 
1781 	if (!skb_queue_empty(&le->inputq))
1782 		tipc_sk_rcv(net, &le->inputq);
1783 
1784 	if (!skb_queue_empty(&xmitq))
1785 		tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1786 
1787 	tipc_node_put(n);
1788 discard:
1789 	kfree_skb(skb);
1790 }
1791 
1792 void tipc_node_apply_property(struct net *net, struct tipc_bearer *b,
1793 			      int prop)
1794 {
1795 	struct tipc_net *tn = tipc_net(net);
1796 	int bearer_id = b->identity;
1797 	struct sk_buff_head xmitq;
1798 	struct tipc_link_entry *e;
1799 	struct tipc_node *n;
1800 
1801 	__skb_queue_head_init(&xmitq);
1802 
1803 	rcu_read_lock();
1804 
1805 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1806 		tipc_node_write_lock(n);
1807 		e = &n->links[bearer_id];
1808 		if (e->link) {
1809 			if (prop == TIPC_NLA_PROP_TOL)
1810 				tipc_link_set_tolerance(e->link, b->tolerance,
1811 							&xmitq);
1812 			else if (prop == TIPC_NLA_PROP_MTU)
1813 				tipc_link_set_mtu(e->link, b->mtu);
1814 		}
1815 		tipc_node_write_unlock(n);
1816 		tipc_bearer_xmit(net, bearer_id, &xmitq, &e->maddr);
1817 	}
1818 
1819 	rcu_read_unlock();
1820 }
1821 
1822 int tipc_nl_peer_rm(struct sk_buff *skb, struct genl_info *info)
1823 {
1824 	struct net *net = sock_net(skb->sk);
1825 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1826 	struct nlattr *attrs[TIPC_NLA_NET_MAX + 1];
1827 	struct tipc_node *peer;
1828 	u32 addr;
1829 	int err;
1830 
1831 	/* We identify the peer by its net */
1832 	if (!info->attrs[TIPC_NLA_NET])
1833 		return -EINVAL;
1834 
1835 	err = nla_parse_nested(attrs, TIPC_NLA_NET_MAX,
1836 			       info->attrs[TIPC_NLA_NET], tipc_nl_net_policy,
1837 			       info->extack);
1838 	if (err)
1839 		return err;
1840 
1841 	if (!attrs[TIPC_NLA_NET_ADDR])
1842 		return -EINVAL;
1843 
1844 	addr = nla_get_u32(attrs[TIPC_NLA_NET_ADDR]);
1845 
1846 	if (in_own_node(net, addr))
1847 		return -ENOTSUPP;
1848 
1849 	spin_lock_bh(&tn->node_list_lock);
1850 	peer = tipc_node_find(net, addr);
1851 	if (!peer) {
1852 		spin_unlock_bh(&tn->node_list_lock);
1853 		return -ENXIO;
1854 	}
1855 
1856 	tipc_node_write_lock(peer);
1857 	if (peer->state != SELF_DOWN_PEER_DOWN &&
1858 	    peer->state != SELF_DOWN_PEER_LEAVING) {
1859 		tipc_node_write_unlock(peer);
1860 		err = -EBUSY;
1861 		goto err_out;
1862 	}
1863 
1864 	tipc_node_clear_links(peer);
1865 	tipc_node_write_unlock(peer);
1866 	tipc_node_delete(peer);
1867 
1868 	err = 0;
1869 err_out:
1870 	tipc_node_put(peer);
1871 	spin_unlock_bh(&tn->node_list_lock);
1872 
1873 	return err;
1874 }
1875 
1876 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1877 {
1878 	int err;
1879 	struct net *net = sock_net(skb->sk);
1880 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1881 	int done = cb->args[0];
1882 	int last_addr = cb->args[1];
1883 	struct tipc_node *node;
1884 	struct tipc_nl_msg msg;
1885 
1886 	if (done)
1887 		return 0;
1888 
1889 	msg.skb = skb;
1890 	msg.portid = NETLINK_CB(cb->skb).portid;
1891 	msg.seq = cb->nlh->nlmsg_seq;
1892 
1893 	rcu_read_lock();
1894 	if (last_addr) {
1895 		node = tipc_node_find(net, last_addr);
1896 		if (!node) {
1897 			rcu_read_unlock();
1898 			/* We never set seq or call nl_dump_check_consistent()
1899 			 * this means that setting prev_seq here will cause the
1900 			 * consistence check to fail in the netlink callback
1901 			 * handler. Resulting in the NLMSG_DONE message having
1902 			 * the NLM_F_DUMP_INTR flag set if the node state
1903 			 * changed while we released the lock.
1904 			 */
1905 			cb->prev_seq = 1;
1906 			return -EPIPE;
1907 		}
1908 		tipc_node_put(node);
1909 	}
1910 
1911 	list_for_each_entry_rcu(node, &tn->node_list, list) {
1912 		if (last_addr) {
1913 			if (node->addr == last_addr)
1914 				last_addr = 0;
1915 			else
1916 				continue;
1917 		}
1918 
1919 		tipc_node_read_lock(node);
1920 		err = __tipc_nl_add_node(&msg, node);
1921 		if (err) {
1922 			last_addr = node->addr;
1923 			tipc_node_read_unlock(node);
1924 			goto out;
1925 		}
1926 
1927 		tipc_node_read_unlock(node);
1928 	}
1929 	done = 1;
1930 out:
1931 	cb->args[0] = done;
1932 	cb->args[1] = last_addr;
1933 	rcu_read_unlock();
1934 
1935 	return skb->len;
1936 }
1937 
1938 /* tipc_node_find_by_name - locate owner node of link by link's name
1939  * @net: the applicable net namespace
1940  * @name: pointer to link name string
1941  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1942  *
1943  * Returns pointer to node owning the link, or 0 if no matching link is found.
1944  */
1945 static struct tipc_node *tipc_node_find_by_name(struct net *net,
1946 						const char *link_name,
1947 						unsigned int *bearer_id)
1948 {
1949 	struct tipc_net *tn = net_generic(net, tipc_net_id);
1950 	struct tipc_link *l;
1951 	struct tipc_node *n;
1952 	struct tipc_node *found_node = NULL;
1953 	int i;
1954 
1955 	*bearer_id = 0;
1956 	rcu_read_lock();
1957 	list_for_each_entry_rcu(n, &tn->node_list, list) {
1958 		tipc_node_read_lock(n);
1959 		for (i = 0; i < MAX_BEARERS; i++) {
1960 			l = n->links[i].link;
1961 			if (l && !strcmp(tipc_link_name(l), link_name)) {
1962 				*bearer_id = i;
1963 				found_node = n;
1964 				break;
1965 			}
1966 		}
1967 		tipc_node_read_unlock(n);
1968 		if (found_node)
1969 			break;
1970 	}
1971 	rcu_read_unlock();
1972 
1973 	return found_node;
1974 }
1975 
1976 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
1977 {
1978 	int err;
1979 	int res = 0;
1980 	int bearer_id;
1981 	char *name;
1982 	struct tipc_link *link;
1983 	struct tipc_node *node;
1984 	struct sk_buff_head xmitq;
1985 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1986 	struct net *net = sock_net(skb->sk);
1987 
1988 	__skb_queue_head_init(&xmitq);
1989 
1990 	if (!info->attrs[TIPC_NLA_LINK])
1991 		return -EINVAL;
1992 
1993 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1994 			       info->attrs[TIPC_NLA_LINK],
1995 			       tipc_nl_link_policy, info->extack);
1996 	if (err)
1997 		return err;
1998 
1999 	if (!attrs[TIPC_NLA_LINK_NAME])
2000 		return -EINVAL;
2001 
2002 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2003 
2004 	if (strcmp(name, tipc_bclink_name) == 0)
2005 		return tipc_nl_bc_link_set(net, attrs);
2006 
2007 	node = tipc_node_find_by_name(net, name, &bearer_id);
2008 	if (!node)
2009 		return -EINVAL;
2010 
2011 	tipc_node_read_lock(node);
2012 
2013 	link = node->links[bearer_id].link;
2014 	if (!link) {
2015 		res = -EINVAL;
2016 		goto out;
2017 	}
2018 
2019 	if (attrs[TIPC_NLA_LINK_PROP]) {
2020 		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2021 
2022 		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2023 					      props);
2024 		if (err) {
2025 			res = err;
2026 			goto out;
2027 		}
2028 
2029 		if (props[TIPC_NLA_PROP_TOL]) {
2030 			u32 tol;
2031 
2032 			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2033 			tipc_link_set_tolerance(link, tol, &xmitq);
2034 		}
2035 		if (props[TIPC_NLA_PROP_PRIO]) {
2036 			u32 prio;
2037 
2038 			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2039 			tipc_link_set_prio(link, prio, &xmitq);
2040 		}
2041 		if (props[TIPC_NLA_PROP_WIN]) {
2042 			u32 win;
2043 
2044 			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2045 			tipc_link_set_queue_limits(link, win);
2046 		}
2047 	}
2048 
2049 out:
2050 	tipc_node_read_unlock(node);
2051 	tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
2052 	return res;
2053 }
2054 
2055 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
2056 {
2057 	struct net *net = genl_info_net(info);
2058 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2059 	struct tipc_nl_msg msg;
2060 	char *name;
2061 	int err;
2062 
2063 	msg.portid = info->snd_portid;
2064 	msg.seq = info->snd_seq;
2065 
2066 	if (!info->attrs[TIPC_NLA_LINK])
2067 		return -EINVAL;
2068 
2069 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2070 			       info->attrs[TIPC_NLA_LINK],
2071 			       tipc_nl_link_policy, info->extack);
2072 	if (err)
2073 		return err;
2074 
2075 	if (!attrs[TIPC_NLA_LINK_NAME])
2076 		return -EINVAL;
2077 
2078 	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2079 
2080 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2081 	if (!msg.skb)
2082 		return -ENOMEM;
2083 
2084 	if (strcmp(name, tipc_bclink_name) == 0) {
2085 		err = tipc_nl_add_bc_link(net, &msg);
2086 		if (err)
2087 			goto err_free;
2088 	} else {
2089 		int bearer_id;
2090 		struct tipc_node *node;
2091 		struct tipc_link *link;
2092 
2093 		node = tipc_node_find_by_name(net, name, &bearer_id);
2094 		if (!node) {
2095 			err = -EINVAL;
2096 			goto err_free;
2097 		}
2098 
2099 		tipc_node_read_lock(node);
2100 		link = node->links[bearer_id].link;
2101 		if (!link) {
2102 			tipc_node_read_unlock(node);
2103 			err = -EINVAL;
2104 			goto err_free;
2105 		}
2106 
2107 		err = __tipc_nl_add_link(net, &msg, link, 0);
2108 		tipc_node_read_unlock(node);
2109 		if (err)
2110 			goto err_free;
2111 	}
2112 
2113 	return genlmsg_reply(msg.skb, info);
2114 
2115 err_free:
2116 	nlmsg_free(msg.skb);
2117 	return err;
2118 }
2119 
2120 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
2121 {
2122 	int err;
2123 	char *link_name;
2124 	unsigned int bearer_id;
2125 	struct tipc_link *link;
2126 	struct tipc_node *node;
2127 	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2128 	struct net *net = sock_net(skb->sk);
2129 	struct tipc_link_entry *le;
2130 
2131 	if (!info->attrs[TIPC_NLA_LINK])
2132 		return -EINVAL;
2133 
2134 	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2135 			       info->attrs[TIPC_NLA_LINK],
2136 			       tipc_nl_link_policy, info->extack);
2137 	if (err)
2138 		return err;
2139 
2140 	if (!attrs[TIPC_NLA_LINK_NAME])
2141 		return -EINVAL;
2142 
2143 	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2144 
2145 	if (strcmp(link_name, tipc_bclink_name) == 0) {
2146 		err = tipc_bclink_reset_stats(net);
2147 		if (err)
2148 			return err;
2149 		return 0;
2150 	}
2151 
2152 	node = tipc_node_find_by_name(net, link_name, &bearer_id);
2153 	if (!node)
2154 		return -EINVAL;
2155 
2156 	le = &node->links[bearer_id];
2157 	tipc_node_read_lock(node);
2158 	spin_lock_bh(&le->lock);
2159 	link = node->links[bearer_id].link;
2160 	if (!link) {
2161 		spin_unlock_bh(&le->lock);
2162 		tipc_node_read_unlock(node);
2163 		return -EINVAL;
2164 	}
2165 	tipc_link_reset_stats(link);
2166 	spin_unlock_bh(&le->lock);
2167 	tipc_node_read_unlock(node);
2168 	return 0;
2169 }
2170 
2171 /* Caller should hold node lock  */
2172 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2173 				    struct tipc_node *node, u32 *prev_link)
2174 {
2175 	u32 i;
2176 	int err;
2177 
2178 	for (i = *prev_link; i < MAX_BEARERS; i++) {
2179 		*prev_link = i;
2180 
2181 		if (!node->links[i].link)
2182 			continue;
2183 
2184 		err = __tipc_nl_add_link(net, msg,
2185 					 node->links[i].link, NLM_F_MULTI);
2186 		if (err)
2187 			return err;
2188 	}
2189 	*prev_link = 0;
2190 
2191 	return 0;
2192 }
2193 
2194 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
2195 {
2196 	struct net *net = sock_net(skb->sk);
2197 	struct tipc_net *tn = net_generic(net, tipc_net_id);
2198 	struct tipc_node *node;
2199 	struct tipc_nl_msg msg;
2200 	u32 prev_node = cb->args[0];
2201 	u32 prev_link = cb->args[1];
2202 	int done = cb->args[2];
2203 	int err;
2204 
2205 	if (done)
2206 		return 0;
2207 
2208 	msg.skb = skb;
2209 	msg.portid = NETLINK_CB(cb->skb).portid;
2210 	msg.seq = cb->nlh->nlmsg_seq;
2211 
2212 	rcu_read_lock();
2213 	if (prev_node) {
2214 		node = tipc_node_find(net, prev_node);
2215 		if (!node) {
2216 			/* We never set seq or call nl_dump_check_consistent()
2217 			 * this means that setting prev_seq here will cause the
2218 			 * consistence check to fail in the netlink callback
2219 			 * handler. Resulting in the last NLMSG_DONE message
2220 			 * having the NLM_F_DUMP_INTR flag set.
2221 			 */
2222 			cb->prev_seq = 1;
2223 			goto out;
2224 		}
2225 		tipc_node_put(node);
2226 
2227 		list_for_each_entry_continue_rcu(node, &tn->node_list,
2228 						 list) {
2229 			tipc_node_read_lock(node);
2230 			err = __tipc_nl_add_node_links(net, &msg, node,
2231 						       &prev_link);
2232 			tipc_node_read_unlock(node);
2233 			if (err)
2234 				goto out;
2235 
2236 			prev_node = node->addr;
2237 		}
2238 	} else {
2239 		err = tipc_nl_add_bc_link(net, &msg);
2240 		if (err)
2241 			goto out;
2242 
2243 		list_for_each_entry_rcu(node, &tn->node_list, list) {
2244 			tipc_node_read_lock(node);
2245 			err = __tipc_nl_add_node_links(net, &msg, node,
2246 						       &prev_link);
2247 			tipc_node_read_unlock(node);
2248 			if (err)
2249 				goto out;
2250 
2251 			prev_node = node->addr;
2252 		}
2253 	}
2254 	done = 1;
2255 out:
2256 	rcu_read_unlock();
2257 
2258 	cb->args[0] = prev_node;
2259 	cb->args[1] = prev_link;
2260 	cb->args[2] = done;
2261 
2262 	return skb->len;
2263 }
2264 
2265 int tipc_nl_node_set_monitor(struct sk_buff *skb, struct genl_info *info)
2266 {
2267 	struct nlattr *attrs[TIPC_NLA_MON_MAX + 1];
2268 	struct net *net = sock_net(skb->sk);
2269 	int err;
2270 
2271 	if (!info->attrs[TIPC_NLA_MON])
2272 		return -EINVAL;
2273 
2274 	err = nla_parse_nested(attrs, TIPC_NLA_MON_MAX,
2275 			       info->attrs[TIPC_NLA_MON],
2276 			       tipc_nl_monitor_policy, info->extack);
2277 	if (err)
2278 		return err;
2279 
2280 	if (attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]) {
2281 		u32 val;
2282 
2283 		val = nla_get_u32(attrs[TIPC_NLA_MON_ACTIVATION_THRESHOLD]);
2284 		err = tipc_nl_monitor_set_threshold(net, val);
2285 		if (err)
2286 			return err;
2287 	}
2288 
2289 	return 0;
2290 }
2291 
2292 static int __tipc_nl_add_monitor_prop(struct net *net, struct tipc_nl_msg *msg)
2293 {
2294 	struct nlattr *attrs;
2295 	void *hdr;
2296 	u32 val;
2297 
2298 	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2299 			  0, TIPC_NL_MON_GET);
2300 	if (!hdr)
2301 		return -EMSGSIZE;
2302 
2303 	attrs = nla_nest_start(msg->skb, TIPC_NLA_MON);
2304 	if (!attrs)
2305 		goto msg_full;
2306 
2307 	val = tipc_nl_monitor_get_threshold(net);
2308 
2309 	if (nla_put_u32(msg->skb, TIPC_NLA_MON_ACTIVATION_THRESHOLD, val))
2310 		goto attr_msg_full;
2311 
2312 	nla_nest_end(msg->skb, attrs);
2313 	genlmsg_end(msg->skb, hdr);
2314 
2315 	return 0;
2316 
2317 attr_msg_full:
2318 	nla_nest_cancel(msg->skb, attrs);
2319 msg_full:
2320 	genlmsg_cancel(msg->skb, hdr);
2321 
2322 	return -EMSGSIZE;
2323 }
2324 
2325 int tipc_nl_node_get_monitor(struct sk_buff *skb, struct genl_info *info)
2326 {
2327 	struct net *net = sock_net(skb->sk);
2328 	struct tipc_nl_msg msg;
2329 	int err;
2330 
2331 	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2332 	if (!msg.skb)
2333 		return -ENOMEM;
2334 	msg.portid = info->snd_portid;
2335 	msg.seq = info->snd_seq;
2336 
2337 	err = __tipc_nl_add_monitor_prop(net, &msg);
2338 	if (err) {
2339 		nlmsg_free(msg.skb);
2340 		return err;
2341 	}
2342 
2343 	return genlmsg_reply(msg.skb, info);
2344 }
2345 
2346 int tipc_nl_node_dump_monitor(struct sk_buff *skb, struct netlink_callback *cb)
2347 {
2348 	struct net *net = sock_net(skb->sk);
2349 	u32 prev_bearer = cb->args[0];
2350 	struct tipc_nl_msg msg;
2351 	int bearer_id;
2352 	int err;
2353 
2354 	if (prev_bearer == MAX_BEARERS)
2355 		return 0;
2356 
2357 	msg.skb = skb;
2358 	msg.portid = NETLINK_CB(cb->skb).portid;
2359 	msg.seq = cb->nlh->nlmsg_seq;
2360 
2361 	rtnl_lock();
2362 	for (bearer_id = prev_bearer; bearer_id < MAX_BEARERS; bearer_id++) {
2363 		err = __tipc_nl_add_monitor(net, &msg, bearer_id);
2364 		if (err)
2365 			break;
2366 	}
2367 	rtnl_unlock();
2368 	cb->args[0] = bearer_id;
2369 
2370 	return skb->len;
2371 }
2372 
2373 int tipc_nl_node_dump_monitor_peer(struct sk_buff *skb,
2374 				   struct netlink_callback *cb)
2375 {
2376 	struct net *net = sock_net(skb->sk);
2377 	u32 prev_node = cb->args[1];
2378 	u32 bearer_id = cb->args[2];
2379 	int done = cb->args[0];
2380 	struct tipc_nl_msg msg;
2381 	int err;
2382 
2383 	if (!prev_node) {
2384 		struct nlattr **attrs;
2385 		struct nlattr *mon[TIPC_NLA_MON_MAX + 1];
2386 
2387 		err = tipc_nlmsg_parse(cb->nlh, &attrs);
2388 		if (err)
2389 			return err;
2390 
2391 		if (!attrs[TIPC_NLA_MON])
2392 			return -EINVAL;
2393 
2394 		err = nla_parse_nested(mon, TIPC_NLA_MON_MAX,
2395 				       attrs[TIPC_NLA_MON],
2396 				       tipc_nl_monitor_policy, NULL);
2397 		if (err)
2398 			return err;
2399 
2400 		if (!mon[TIPC_NLA_MON_REF])
2401 			return -EINVAL;
2402 
2403 		bearer_id = nla_get_u32(mon[TIPC_NLA_MON_REF]);
2404 
2405 		if (bearer_id >= MAX_BEARERS)
2406 			return -EINVAL;
2407 	}
2408 
2409 	if (done)
2410 		return 0;
2411 
2412 	msg.skb = skb;
2413 	msg.portid = NETLINK_CB(cb->skb).portid;
2414 	msg.seq = cb->nlh->nlmsg_seq;
2415 
2416 	rtnl_lock();
2417 	err = tipc_nl_add_monitor_peer(net, &msg, bearer_id, &prev_node);
2418 	if (!err)
2419 		done = 1;
2420 
2421 	rtnl_unlock();
2422 	cb->args[0] = done;
2423 	cb->args[1] = prev_node;
2424 	cb->args[2] = bearer_id;
2425 
2426 	return skb->len;
2427 }
2428