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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / net / tipc / node.c
blobace178fd385038523bc498222e9497245ccae4b0
1 /*
2 * net/tipc/node.c: TIPC node management routines
3 *
4 * Copyright (c) 2000-2006, 2012-2015, 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 "discover.h"
44 #include "netlink.h"
45
46 #define INVALID_NODE_SIG 0x10000
47
48 /* Flags used to take different actions according to flag type
49 * TIPC_NOTIFY_NODE_DOWN: notify node is down
50 * TIPC_NOTIFY_NODE_UP: notify node is up
51 * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
52 */
53 enum {
54 TIPC_NOTIFY_NODE_DOWN = (1 << 3),
55 TIPC_NOTIFY_NODE_UP = (1 << 4),
56 TIPC_NOTIFY_LINK_UP = (1 << 6),
57 TIPC_NOTIFY_LINK_DOWN = (1 << 7)
58 };
59
60 struct tipc_link_entry {
61 struct tipc_link *link;
62 spinlock_t lock; /* per link */
63 u32 mtu;
64 struct sk_buff_head inputq;
65 struct tipc_media_addr maddr;
66 };
67
68 struct tipc_bclink_entry {
69 struct tipc_link *link;
70 struct sk_buff_head inputq1;
71 struct sk_buff_head arrvq;
72 struct sk_buff_head inputq2;
73 struct sk_buff_head namedq;
74 };
75
76 /**
77 * struct tipc_node - TIPC node structure
78 * @addr: network address of node
79 * @ref: reference counter to node object
80 * @lock: rwlock governing access to structure
81 * @net: the applicable net namespace
82 * @hash: links to adjacent nodes in unsorted hash chain
83 * @inputq: pointer to input queue containing messages for msg event
84 * @namedq: pointer to name table input queue with name table messages
85 * @active_links: bearer ids of active links, used as index into links[] array
86 * @links: array containing references to all links to node
87 * @action_flags: bit mask of different types of node actions
88 * @state: connectivity state vs peer node
89 * @sync_point: sequence number where synch/failover is finished
90 * @list: links to adjacent nodes in sorted list of cluster's nodes
91 * @working_links: number of working links to node (both active and standby)
92 * @link_cnt: number of links to node
93 * @capabilities: bitmap, indicating peer node's functional capabilities
94 * @signature: node instance identifier
95 * @link_id: local and remote bearer ids of changing link, if any
96 * @publ_list: list of publications
97 * @rcu: rcu struct for tipc_node
98 */
99 struct tipc_node {
100 u32 addr;
101 struct kref kref;
102 rwlock_t lock;
103 struct net *net;
104 struct hlist_node hash;
105 int active_links[2];
106 struct tipc_link_entry links[MAX_BEARERS];
107 struct tipc_bclink_entry bc_entry;
108 int action_flags;
109 struct list_head list;
110 int state;
111 u16 sync_point;
112 int link_cnt;
113 u16 working_links;
114 u16 capabilities;
115 u32 signature;
116 u32 link_id;
117 struct list_head publ_list;
118 struct list_head conn_sks;
119 unsigned long keepalive_intv;
120 struct timer_list timer;
121 struct rcu_head rcu;
122 };
123
124 /* Node FSM states and events:
125 */
126 enum {
127 SELF_DOWN_PEER_DOWN = 0xdd,
128 SELF_UP_PEER_UP = 0xaa,
129 SELF_DOWN_PEER_LEAVING = 0xd1,
130 SELF_UP_PEER_COMING = 0xac,
131 SELF_COMING_PEER_UP = 0xca,
132 SELF_LEAVING_PEER_DOWN = 0x1d,
133 NODE_FAILINGOVER = 0xf0,
134 NODE_SYNCHING = 0xcc
135 };
136
137 enum {
138 SELF_ESTABL_CONTACT_EVT = 0xece,
139 SELF_LOST_CONTACT_EVT = 0x1ce,
140 PEER_ESTABL_CONTACT_EVT = 0x9ece,
141 PEER_LOST_CONTACT_EVT = 0x91ce,
142 NODE_FAILOVER_BEGIN_EVT = 0xfbe,
143 NODE_FAILOVER_END_EVT = 0xfee,
144 NODE_SYNCH_BEGIN_EVT = 0xcbe,
145 NODE_SYNCH_END_EVT = 0xcee
146 };
147
148 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
149 struct sk_buff_head *xmitq,
150 struct tipc_media_addr **maddr);
151 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
152 bool delete);
153 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
154 static void tipc_node_delete(struct tipc_node *node);
155 static void tipc_node_timeout(unsigned long data);
156 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
157 static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
158 static void tipc_node_put(struct tipc_node *node);
159 static bool tipc_node_is_up(struct tipc_node *n);
160
161 struct tipc_sock_conn {
162 u32 port;
163 u32 peer_port;
164 u32 peer_node;
165 struct list_head list;
166 };
167
168 static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
169 {
170 int bearer_id = n->active_links[sel & 1];
171
172 if (unlikely(bearer_id == INVALID_BEARER_ID))
173 return NULL;
174
175 return n->links[bearer_id].link;
176 }
177
178 int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
179 {
180 struct tipc_node *n;
181 int bearer_id;
182 unsigned int mtu = MAX_MSG_SIZE;
183
184 n = tipc_node_find(net, addr);
185 if (unlikely(!n))
186 return mtu;
187
188 bearer_id = n->active_links[sel & 1];
189 if (likely(bearer_id != INVALID_BEARER_ID))
190 mtu = n->links[bearer_id].mtu;
191 tipc_node_put(n);
192 return mtu;
193 }
194 /*
195 * A trivial power-of-two bitmask technique is used for speed, since this
196 * operation is done for every incoming TIPC packet. The number of hash table
197 * entries has been chosen so that no hash chain exceeds 8 nodes and will
198 * usually be much smaller (typically only a single node).
199 */
200 static unsigned int tipc_hashfn(u32 addr)
201 {
202 return addr & (NODE_HTABLE_SIZE - 1);
203 }
204
205 static void tipc_node_kref_release(struct kref *kref)
206 {
207 struct tipc_node *n = container_of(kref, struct tipc_node, kref);
208
209 kfree(n->bc_entry.link);
210 kfree_rcu(n, rcu);
211 }
212
213 static void tipc_node_put(struct tipc_node *node)
214 {
215 kref_put(&node->kref, tipc_node_kref_release);
216 }
217
218 static void tipc_node_get(struct tipc_node *node)
219 {
220 kref_get(&node->kref);
221 }
222
223 /*
224 * tipc_node_find - locate specified node object, if it exists
225 */
226 static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
227 {
228 struct tipc_net *tn = tipc_net(net);
229 struct tipc_node *node;
230 unsigned int thash = tipc_hashfn(addr);
231
232 if (unlikely(!in_own_cluster_exact(net, addr)))
233 return NULL;
234
235 rcu_read_lock();
236 hlist_for_each_entry_rcu(node, &tn->node_htable[thash], hash) {
237 if (node->addr != addr)
238 continue;
239 if (!kref_get_unless_zero(&node->kref))
240 node = NULL;
241 break;
242 }
243 rcu_read_unlock();
244 return node;
245 }
246
247 static void tipc_node_read_lock(struct tipc_node *n)
248 {
249 read_lock_bh(&n->lock);
250 }
251
252 static void tipc_node_read_unlock(struct tipc_node *n)
253 {
254 read_unlock_bh(&n->lock);
255 }
256
257 static void tipc_node_write_lock(struct tipc_node *n)
258 {
259 write_lock_bh(&n->lock);
260 }
261
262 static void tipc_node_write_unlock(struct tipc_node *n)
263 {
264 struct net *net = n->net;
265 u32 addr = 0;
266 u32 flags = n->action_flags;
267 u32 link_id = 0;
268 struct list_head *publ_list;
269
270 if (likely(!flags)) {
271 write_unlock_bh(&n->lock);
272 return;
273 }
274
275 addr = n->addr;
276 link_id = n->link_id;
277 publ_list = &n->publ_list;
278
279 n->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
280 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
281
282 write_unlock_bh(&n->lock);
283
284 if (flags & TIPC_NOTIFY_NODE_DOWN)
285 tipc_publ_notify(net, publ_list, addr);
286
287 if (flags & TIPC_NOTIFY_NODE_UP)
288 tipc_named_node_up(net, addr);
289
290 if (flags & TIPC_NOTIFY_LINK_UP)
291 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
292 TIPC_NODE_SCOPE, link_id, addr);
293
294 if (flags & TIPC_NOTIFY_LINK_DOWN)
295 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
296 link_id, addr);
297 }
298
299 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
300 {
301 struct tipc_net *tn = net_generic(net, tipc_net_id);
302 struct tipc_node *n, *temp_node;
303 int i;
304
305 spin_lock_bh(&tn->node_list_lock);
306 n = tipc_node_find(net, addr);
307 if (n)
308 goto exit;
309 n = kzalloc(sizeof(*n), GFP_ATOMIC);
310 if (!n) {
311 pr_warn("Node creation failed, no memory\n");
312 goto exit;
313 }
314 n->addr = addr;
315 n->net = net;
316 n->capabilities = capabilities;
317 kref_init(&n->kref);
318 rwlock_init(&n->lock);
319 INIT_HLIST_NODE(&n->hash);
320 INIT_LIST_HEAD(&n->list);
321 INIT_LIST_HEAD(&n->publ_list);
322 INIT_LIST_HEAD(&n->conn_sks);
323 skb_queue_head_init(&n->bc_entry.namedq);
324 skb_queue_head_init(&n->bc_entry.inputq1);
325 __skb_queue_head_init(&n->bc_entry.arrvq);
326 skb_queue_head_init(&n->bc_entry.inputq2);
327 for (i = 0; i < MAX_BEARERS; i++)
328 spin_lock_init(&n->links[i].lock);
329 n->state = SELF_DOWN_PEER_LEAVING;
330 n->signature = INVALID_NODE_SIG;
331 n->active_links[0] = INVALID_BEARER_ID;
332 n->active_links[1] = INVALID_BEARER_ID;
333 if (!tipc_link_bc_create(net, tipc_own_addr(net), n->addr,
334 U16_MAX,
335 tipc_link_window(tipc_bc_sndlink(net)),
336 n->capabilities,
337 &n->bc_entry.inputq1,
338 &n->bc_entry.namedq,
339 tipc_bc_sndlink(net),
340 &n->bc_entry.link)) {
341 pr_warn("Broadcast rcv link creation failed, no memory\n");
342 kfree(n);
343 n = NULL;
344 goto exit;
345 }
346 tipc_node_get(n);
347 setup_timer(&n->timer, tipc_node_timeout, (unsigned long)n);
348 n->keepalive_intv = U32_MAX;
349 hlist_add_head_rcu(&n->hash, &tn->node_htable[tipc_hashfn(addr)]);
350 list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
351 if (n->addr < temp_node->addr)
352 break;
353 }
354 list_add_tail_rcu(&n->list, &temp_node->list);
355 exit:
356 spin_unlock_bh(&tn->node_list_lock);
357 return n;
358 }
359
360 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
361 {
362 unsigned long tol = tipc_link_tolerance(l);
363 unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
364 unsigned long keepalive_intv = msecs_to_jiffies(intv);
365
366 /* Link with lowest tolerance determines timer interval */
367 if (keepalive_intv < n->keepalive_intv)
368 n->keepalive_intv = keepalive_intv;
369
370 /* Ensure link's abort limit corresponds to current interval */
371 tipc_link_set_abort_limit(l, tol / jiffies_to_msecs(n->keepalive_intv));
372 }
373
374 static void tipc_node_delete(struct tipc_node *node)
375 {
376 list_del_rcu(&node->list);
377 hlist_del_rcu(&node->hash);
378 tipc_node_put(node);
379
380 del_timer_sync(&node->timer);
381 tipc_node_put(node);
382 }
383
384 void tipc_node_stop(struct net *net)
385 {
386 struct tipc_net *tn = tipc_net(net);
387 struct tipc_node *node, *t_node;
388
389 spin_lock_bh(&tn->node_list_lock);
390 list_for_each_entry_safe(node, t_node, &tn->node_list, list)
391 tipc_node_delete(node);
392 spin_unlock_bh(&tn->node_list_lock);
393 }
394
395 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
396 {
397 struct tipc_node *n;
398
399 if (in_own_node(net, addr))
400 return;
401
402 n = tipc_node_find(net, addr);
403 if (!n) {
404 pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
405 return;
406 }
407 tipc_node_write_lock(n);
408 list_add_tail(subscr, &n->publ_list);
409 tipc_node_write_unlock(n);
410 tipc_node_put(n);
411 }
412
413 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
414 {
415 struct tipc_node *n;
416
417 if (in_own_node(net, addr))
418 return;
419
420 n = tipc_node_find(net, addr);
421 if (!n) {
422 pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
423 return;
424 }
425 tipc_node_write_lock(n);
426 list_del_init(subscr);
427 tipc_node_write_unlock(n);
428 tipc_node_put(n);
429 }
430
431 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
432 {
433 struct tipc_node *node;
434 struct tipc_sock_conn *conn;
435 int err = 0;
436
437 if (in_own_node(net, dnode))
438 return 0;
439
440 node = tipc_node_find(net, dnode);
441 if (!node) {
442 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
443 return -EHOSTUNREACH;
444 }
445 conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
446 if (!conn) {
447 err = -EHOSTUNREACH;
448 goto exit;
449 }
450 conn->peer_node = dnode;
451 conn->port = port;
452 conn->peer_port = peer_port;
453
454 tipc_node_write_lock(node);
455 list_add_tail(&conn->list, &node->conn_sks);
456 tipc_node_write_unlock(node);
457 exit:
458 tipc_node_put(node);
459 return err;
460 }
461
462 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
463 {
464 struct tipc_node *node;
465 struct tipc_sock_conn *conn, *safe;
466
467 if (in_own_node(net, dnode))
468 return;
469
470 node = tipc_node_find(net, dnode);
471 if (!node)
472 return;
473
474 tipc_node_write_lock(node);
475 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
476 if (port != conn->port)
477 continue;
478 list_del(&conn->list);
479 kfree(conn);
480 }
481 tipc_node_write_unlock(node);
482 tipc_node_put(node);
483 }
484
485 /* tipc_node_timeout - handle expiration of node timer
486 */
487 static void tipc_node_timeout(unsigned long data)
488 {
489 struct tipc_node *n = (struct tipc_node *)data;
490 struct tipc_link_entry *le;
491 struct sk_buff_head xmitq;
492 int bearer_id;
493 int rc = 0;
494
495 __skb_queue_head_init(&xmitq);
496
497 for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
498 tipc_node_read_lock(n);
499 le = &n->links[bearer_id];
500 spin_lock_bh(&le->lock);
501 if (le->link) {
502 /* Link tolerance may change asynchronously: */
503 tipc_node_calculate_timer(n, le->link);
504 rc = tipc_link_timeout(le->link, &xmitq);
505 }
506 spin_unlock_bh(&le->lock);
507 tipc_node_read_unlock(n);
508 tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
509 if (rc & TIPC_LINK_DOWN_EVT)
510 tipc_node_link_down(n, bearer_id, false);
511 }
512 mod_timer(&n->timer, jiffies + n->keepalive_intv);
513 }
514
515 /**
516 * __tipc_node_link_up - handle addition of link
517 * Node lock must be held by caller
518 * Link becomes active (alone or shared) or standby, depending on its priority.
519 */
520 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
521 struct sk_buff_head *xmitq)
522 {
523 int *slot0 = &n->active_links[0];
524 int *slot1 = &n->active_links[1];
525 struct tipc_link *ol = node_active_link(n, 0);
526 struct tipc_link *nl = n->links[bearer_id].link;
527
528 if (!nl)
529 return;
530
531 tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
532 if (!tipc_link_is_up(nl))
533 return;
534
535 n->working_links++;
536 n->action_flags |= TIPC_NOTIFY_LINK_UP;
537 n->link_id = tipc_link_id(nl);
538
539 /* Leave room for tunnel header when returning 'mtu' to users: */
540 n->links[bearer_id].mtu = tipc_link_mtu(nl) - INT_H_SIZE;
541
542 tipc_bearer_add_dest(n->net, bearer_id, n->addr);
543 tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
544
545 pr_debug("Established link <%s> on network plane %c\n",
546 tipc_link_name(nl), tipc_link_plane(nl));
547
548 /* First link? => give it both slots */
549 if (!ol) {
550 *slot0 = bearer_id;
551 *slot1 = bearer_id;
552 tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
553 n->action_flags |= TIPC_NOTIFY_NODE_UP;
554 tipc_bcast_add_peer(n->net, nl, xmitq);
555 return;
556 }
557
558 /* Second link => redistribute slots */
559 if (tipc_link_prio(nl) > tipc_link_prio(ol)) {
560 pr_debug("Old link <%s> becomes standby\n", tipc_link_name(ol));
561 *slot0 = bearer_id;
562 *slot1 = bearer_id;
563 tipc_link_set_active(nl, true);
564 tipc_link_set_active(ol, false);
565 } else if (tipc_link_prio(nl) == tipc_link_prio(ol)) {
566 tipc_link_set_active(nl, true);
567 *slot1 = bearer_id;
568 } else {
569 pr_debug("New link <%s> is standby\n", tipc_link_name(nl));
570 }
571
572 /* Prepare synchronization with first link */
573 tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
574 }
575
576 /**
577 * tipc_node_link_up - handle addition of link
578 *
579 * Link becomes active (alone or shared) or standby, depending on its priority.
580 */
581 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
582 struct sk_buff_head *xmitq)
583 {
584 tipc_node_write_lock(n);
585 __tipc_node_link_up(n, bearer_id, xmitq);
586 tipc_node_write_unlock(n);
587 }
588
589 /**
590 * __tipc_node_link_down - handle loss of link
591 */
592 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
593 struct sk_buff_head *xmitq,
594 struct tipc_media_addr **maddr)
595 {
596 struct tipc_link_entry *le = &n->links[*bearer_id];
597 int *slot0 = &n->active_links[0];
598 int *slot1 = &n->active_links[1];
599 int i, highest = 0, prio;
600 struct tipc_link *l, *_l, *tnl;
601
602 l = n->links[*bearer_id].link;
603 if (!l || tipc_link_is_reset(l))
604 return;
605
606 n->working_links--;
607 n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
608 n->link_id = tipc_link_id(l);
609
610 tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
611
612 pr_debug("Lost link <%s> on network plane %c\n",
613 tipc_link_name(l), tipc_link_plane(l));
614
615 /* Select new active link if any available */
616 *slot0 = INVALID_BEARER_ID;
617 *slot1 = INVALID_BEARER_ID;
618 for (i = 0; i < MAX_BEARERS; i++) {
619 _l = n->links[i].link;
620 if (!_l || !tipc_link_is_up(_l))
621 continue;
622 if (_l == l)
623 continue;
624 prio = tipc_link_prio(_l);
625 if (prio < highest)
626 continue;
627 if (prio > highest) {
628 highest = prio;
629 *slot0 = i;
630 *slot1 = i;
631 continue;
632 }
633 *slot1 = i;
634 }
635
636 if (!tipc_node_is_up(n)) {
637 if (tipc_link_peer_is_down(l))
638 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
639 tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
640 tipc_link_fsm_evt(l, LINK_RESET_EVT);
641 tipc_link_reset(l);
642 tipc_link_build_reset_msg(l, xmitq);
643 *maddr = &n->links[*bearer_id].maddr;
644 node_lost_contact(n, &le->inputq);
645 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
646 return;
647 }
648 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
649
650 /* There is still a working link => initiate failover */
651 *bearer_id = n->active_links[0];
652 tnl = n->links[*bearer_id].link;
653 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
654 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
655 n->sync_point = tipc_link_rcv_nxt(tnl) + (U16_MAX / 2 - 1);
656 tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
657 tipc_link_reset(l);
658 tipc_link_fsm_evt(l, LINK_RESET_EVT);
659 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
660 tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
661 *maddr = &n->links[*bearer_id].maddr;
662 }
663
664 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
665 {
666 struct tipc_link_entry *le = &n->links[bearer_id];
667 struct tipc_link *l = le->link;
668 struct tipc_media_addr *maddr;
669 struct sk_buff_head xmitq;
670
671 if (!l)
672 return;
673
674 __skb_queue_head_init(&xmitq);
675
676 tipc_node_write_lock(n);
677 if (!tipc_link_is_establishing(l)) {
678 __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
679 if (delete) {
680 kfree(l);
681 le->link = NULL;
682 n->link_cnt--;
683 }
684 } else {
685 /* Defuse pending tipc_node_link_up() */
686 tipc_link_fsm_evt(l, LINK_RESET_EVT);
687 }
688 tipc_node_write_unlock(n);
689 tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
690 tipc_sk_rcv(n->net, &le->inputq);
691 }
692
693 static bool tipc_node_is_up(struct tipc_node *n)
694 {
695 return n->active_links[0] != INVALID_BEARER_ID;
696 }
697
698 void tipc_node_check_dest(struct net *net, u32 onode,
699 struct tipc_bearer *b,
700 u16 capabilities, u32 signature,
701 struct tipc_media_addr *maddr,
702 bool *respond, bool *dupl_addr)
703 {
704 struct tipc_node *n;
705 struct tipc_link *l;
706 struct tipc_link_entry *le;
707 bool addr_match = false;
708 bool sign_match = false;
709 bool link_up = false;
710 bool accept_addr = false;
711 bool reset = true;
712 char *if_name;
713
714 *dupl_addr = false;
715 *respond = false;
716
717 n = tipc_node_create(net, onode, capabilities);
718 if (!n)
719 return;
720
721 tipc_node_write_lock(n);
722
723 le = &n->links[b->identity];
724
725 /* Prepare to validate requesting node's signature and media address */
726 l = le->link;
727 link_up = l && tipc_link_is_up(l);
728 addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
729 sign_match = (signature == n->signature);
730
731 /* These three flags give us eight permutations: */
732
733 if (sign_match && addr_match && link_up) {
734 /* All is fine. Do nothing. */
735 reset = false;
736 } else if (sign_match && addr_match && !link_up) {
737 /* Respond. The link will come up in due time */
738 *respond = true;
739 } else if (sign_match && !addr_match && link_up) {
740 /* Peer has changed i/f address without rebooting.
741 * If so, the link will reset soon, and the next
742 * discovery will be accepted. So we can ignore it.
743 * It may also be an cloned or malicious peer having
744 * chosen the same node address and signature as an
745 * existing one.
746 * Ignore requests until the link goes down, if ever.
747 */
748 *dupl_addr = true;
749 } else if (sign_match && !addr_match && !link_up) {
750 /* Peer link has changed i/f address without rebooting.
751 * It may also be a cloned or malicious peer; we can't
752 * distinguish between the two.
753 * The signature is correct, so we must accept.
754 */
755 accept_addr = true;
756 *respond = true;
757 } else if (!sign_match && addr_match && link_up) {
758 /* Peer node rebooted. Two possibilities:
759 * - Delayed re-discovery; this link endpoint has already
760 * reset and re-established contact with the peer, before
761 * receiving a discovery message from that node.
762 * (The peer happened to receive one from this node first).
763 * - The peer came back so fast that our side has not
764 * discovered it yet. Probing from this side will soon
765 * reset the link, since there can be no working link
766 * endpoint at the peer end, and the link will re-establish.
767 * Accept the signature, since it comes from a known peer.
768 */
769 n->signature = signature;
770 } else if (!sign_match && addr_match && !link_up) {
771 /* The peer node has rebooted.
772 * Accept signature, since it is a known peer.
773 */
774 n->signature = signature;
775 *respond = true;
776 } else if (!sign_match && !addr_match && link_up) {
777 /* Peer rebooted with new address, or a new/duplicate peer.
778 * Ignore until the link goes down, if ever.
779 */
780 *dupl_addr = true;
781 } else if (!sign_match && !addr_match && !link_up) {
782 /* Peer rebooted with new address, or it is a new peer.
783 * Accept signature and address.
784 */
785 n->signature = signature;
786 accept_addr = true;
787 *respond = true;
788 }
789
790 if (!accept_addr)
791 goto exit;
792
793 /* Now create new link if not already existing */
794 if (!l) {
795 if (n->link_cnt == 2) {
796 pr_warn("Cannot establish 3rd link to %x\n", n->addr);
797 goto exit;
798 }
799 if_name = strchr(b->name, ':') + 1;
800 if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
801 b->net_plane, b->mtu, b->priority,
802 b->window, mod(tipc_net(net)->random),
803 tipc_own_addr(net), onode,
804 n->capabilities,
805 tipc_bc_sndlink(n->net), n->bc_entry.link,
806 &le->inputq,
807 &n->bc_entry.namedq, &l)) {
808 *respond = false;
809 goto exit;
810 }
811 tipc_link_reset(l);
812 tipc_link_fsm_evt(l, LINK_RESET_EVT);
813 if (n->state == NODE_FAILINGOVER)
814 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
815 le->link = l;
816 n->link_cnt++;
817 tipc_node_calculate_timer(n, l);
818 if (n->link_cnt == 1)
819 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
820 tipc_node_get(n);
821 }
822 memcpy(&le->maddr, maddr, sizeof(*maddr));
823 exit:
824 tipc_node_write_unlock(n);
825 if (reset && l && !tipc_link_is_reset(l))
826 tipc_node_link_down(n, b->identity, false);
827 tipc_node_put(n);
828 }
829
830 void tipc_node_delete_links(struct net *net, int bearer_id)
831 {
832 struct tipc_net *tn = net_generic(net, tipc_net_id);
833 struct tipc_node *n;
834
835 rcu_read_lock();
836 list_for_each_entry_rcu(n, &tn->node_list, list) {
837 tipc_node_link_down(n, bearer_id, true);
838 }
839 rcu_read_unlock();
840 }
841
842 static void tipc_node_reset_links(struct tipc_node *n)
843 {
844 char addr_string[16];
845 int i;
846
847 pr_warn("Resetting all links to %s\n",
848 tipc_addr_string_fill(addr_string, n->addr));
849
850 for (i = 0; i < MAX_BEARERS; i++) {
851 tipc_node_link_down(n, i, false);
852 }
853 }
854
855 /* tipc_node_fsm_evt - node finite state machine
856 * Determines when contact is allowed with peer node
857 */
858 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
859 {
860 int state = n->state;
861
862 switch (state) {
863 case SELF_DOWN_PEER_DOWN:
864 switch (evt) {
865 case SELF_ESTABL_CONTACT_EVT:
866 state = SELF_UP_PEER_COMING;
867 break;
868 case PEER_ESTABL_CONTACT_EVT:
869 state = SELF_COMING_PEER_UP;
870 break;
871 case SELF_LOST_CONTACT_EVT:
872 case PEER_LOST_CONTACT_EVT:
873 break;
874 case NODE_SYNCH_END_EVT:
875 case NODE_SYNCH_BEGIN_EVT:
876 case NODE_FAILOVER_BEGIN_EVT:
877 case NODE_FAILOVER_END_EVT:
878 default:
879 goto illegal_evt;
880 }
881 break;
882 case SELF_UP_PEER_UP:
883 switch (evt) {
884 case SELF_LOST_CONTACT_EVT:
885 state = SELF_DOWN_PEER_LEAVING;
886 break;
887 case PEER_LOST_CONTACT_EVT:
888 state = SELF_LEAVING_PEER_DOWN;
889 break;
890 case NODE_SYNCH_BEGIN_EVT:
891 state = NODE_SYNCHING;
892 break;
893 case NODE_FAILOVER_BEGIN_EVT:
894 state = NODE_FAILINGOVER;
895 break;
896 case SELF_ESTABL_CONTACT_EVT:
897 case PEER_ESTABL_CONTACT_EVT:
898 case NODE_SYNCH_END_EVT:
899 case NODE_FAILOVER_END_EVT:
900 break;
901 default:
902 goto illegal_evt;
903 }
904 break;
905 case SELF_DOWN_PEER_LEAVING:
906 switch (evt) {
907 case PEER_LOST_CONTACT_EVT:
908 state = SELF_DOWN_PEER_DOWN;
909 break;
910 case SELF_ESTABL_CONTACT_EVT:
911 case PEER_ESTABL_CONTACT_EVT:
912 case SELF_LOST_CONTACT_EVT:
913 break;
914 case NODE_SYNCH_END_EVT:
915 case NODE_SYNCH_BEGIN_EVT:
916 case NODE_FAILOVER_BEGIN_EVT:
917 case NODE_FAILOVER_END_EVT:
918 default:
919 goto illegal_evt;
920 }
921 break;
922 case SELF_UP_PEER_COMING:
923 switch (evt) {
924 case PEER_ESTABL_CONTACT_EVT:
925 state = SELF_UP_PEER_UP;
926 break;
927 case SELF_LOST_CONTACT_EVT:
928 state = SELF_DOWN_PEER_LEAVING;
929 break;
930 case SELF_ESTABL_CONTACT_EVT:
931 case PEER_LOST_CONTACT_EVT:
932 case NODE_SYNCH_END_EVT:
933 case NODE_FAILOVER_BEGIN_EVT:
934 break;
935 case NODE_SYNCH_BEGIN_EVT:
936 case NODE_FAILOVER_END_EVT:
937 default:
938 goto illegal_evt;
939 }
940 break;
941 case SELF_COMING_PEER_UP:
942 switch (evt) {
943 case SELF_ESTABL_CONTACT_EVT:
944 state = SELF_UP_PEER_UP;
945 break;
946 case PEER_LOST_CONTACT_EVT:
947 state = SELF_LEAVING_PEER_DOWN;
948 break;
949 case SELF_LOST_CONTACT_EVT:
950 case PEER_ESTABL_CONTACT_EVT:
951 break;
952 case NODE_SYNCH_END_EVT:
953 case NODE_SYNCH_BEGIN_EVT:
954 case NODE_FAILOVER_BEGIN_EVT:
955 case NODE_FAILOVER_END_EVT:
956 default:
957 goto illegal_evt;
958 }
959 break;
960 case SELF_LEAVING_PEER_DOWN:
961 switch (evt) {
962 case SELF_LOST_CONTACT_EVT:
963 state = SELF_DOWN_PEER_DOWN;
964 break;
965 case SELF_ESTABL_CONTACT_EVT:
966 case PEER_ESTABL_CONTACT_EVT:
967 case PEER_LOST_CONTACT_EVT:
968 break;
969 case NODE_SYNCH_END_EVT:
970 case NODE_SYNCH_BEGIN_EVT:
971 case NODE_FAILOVER_BEGIN_EVT:
972 case NODE_FAILOVER_END_EVT:
973 default:
974 goto illegal_evt;
975 }
976 break;
977 case NODE_FAILINGOVER:
978 switch (evt) {
979 case SELF_LOST_CONTACT_EVT:
980 state = SELF_DOWN_PEER_LEAVING;
981 break;
982 case PEER_LOST_CONTACT_EVT:
983 state = SELF_LEAVING_PEER_DOWN;
984 break;
985 case NODE_FAILOVER_END_EVT:
986 state = SELF_UP_PEER_UP;
987 break;
988 case NODE_FAILOVER_BEGIN_EVT:
989 case SELF_ESTABL_CONTACT_EVT:
990 case PEER_ESTABL_CONTACT_EVT:
991 break;
992 case NODE_SYNCH_BEGIN_EVT:
993 case NODE_SYNCH_END_EVT:
994 default:
995 goto illegal_evt;
996 }
997 break;
998 case NODE_SYNCHING:
999 switch (evt) {
1000 case SELF_LOST_CONTACT_EVT:
1001 state = SELF_DOWN_PEER_LEAVING;
1002 break;
1003 case PEER_LOST_CONTACT_EVT:
1004 state = SELF_LEAVING_PEER_DOWN;
1005 break;
1006 case NODE_SYNCH_END_EVT:
1007 state = SELF_UP_PEER_UP;
1008 break;
1009 case NODE_FAILOVER_BEGIN_EVT:
1010 state = NODE_FAILINGOVER;
1011 break;
1012 case NODE_SYNCH_BEGIN_EVT:
1013 case SELF_ESTABL_CONTACT_EVT:
1014 case PEER_ESTABL_CONTACT_EVT:
1015 break;
1016 case NODE_FAILOVER_END_EVT:
1017 default:
1018 goto illegal_evt;
1019 }
1020 break;
1021 default:
1022 pr_err("Unknown node fsm state %x\n", state);
1023 break;
1024 }
1025 n->state = state;
1026 return;
1027
1028 illegal_evt:
1029 pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
1030 }
1031
1032 static void node_lost_contact(struct tipc_node *n,
1033 struct sk_buff_head *inputq)
1034 {
1035 char addr_string[16];
1036 struct tipc_sock_conn *conn, *safe;
1037 struct tipc_link *l;
1038 struct list_head *conns = &n->conn_sks;
1039 struct sk_buff *skb;
1040 uint i;
1041
1042 pr_debug("Lost contact with %s\n",
1043 tipc_addr_string_fill(addr_string, n->addr));
1044
1045 /* Clean up broadcast state */
1046 tipc_bcast_remove_peer(n->net, n->bc_entry.link);
1047
1048 /* Abort any ongoing link failover */
1049 for (i = 0; i < MAX_BEARERS; i++) {
1050 l = n->links[i].link;
1051 if (l)
1052 tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
1053 }
1054
1055 /* Notify publications from this node */
1056 n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
1057
1058 /* Notify sockets connected to node */
1059 list_for_each_entry_safe(conn, safe, conns, list) {
1060 skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
1061 SHORT_H_SIZE, 0, tipc_own_addr(n->net),
1062 conn->peer_node, conn->port,
1063 conn->peer_port, TIPC_ERR_NO_NODE);
1064 if (likely(skb))
1065 skb_queue_tail(inputq, skb);
1066 list_del(&conn->list);
1067 kfree(conn);
1068 }
1069 }
1070
1071 /**
1072 * tipc_node_get_linkname - get the name of a link
1073 *
1074 * @bearer_id: id of the bearer
1075 * @node: peer node address
1076 * @linkname: link name output buffer
1077 *
1078 * Returns 0 on success
1079 */
1080 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
1081 char *linkname, size_t len)
1082 {
1083 struct tipc_link *link;
1084 int err = -EINVAL;
1085 struct tipc_node *node = tipc_node_find(net, addr);
1086
1087 if (!node)
1088 return err;
1089
1090 if (bearer_id >= MAX_BEARERS)
1091 goto exit;
1092
1093 tipc_node_read_lock(node);
1094 link = node->links[bearer_id].link;
1095 if (link) {
1096 strncpy(linkname, tipc_link_name(link), len);
1097 err = 0;
1098 }
1099 exit:
1100 tipc_node_read_unlock(node);
1101 tipc_node_put(node);
1102 return err;
1103 }
1104
1105 /* Caller should hold node lock for the passed node */
1106 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1107 {
1108 void *hdr;
1109 struct nlattr *attrs;
1110
1111 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1112 NLM_F_MULTI, TIPC_NL_NODE_GET);
1113 if (!hdr)
1114 return -EMSGSIZE;
1115
1116 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
1117 if (!attrs)
1118 goto msg_full;
1119
1120 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1121 goto attr_msg_full;
1122 if (tipc_node_is_up(node))
1123 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1124 goto attr_msg_full;
1125
1126 nla_nest_end(msg->skb, attrs);
1127 genlmsg_end(msg->skb, hdr);
1128
1129 return 0;
1130
1131 attr_msg_full:
1132 nla_nest_cancel(msg->skb, attrs);
1133 msg_full:
1134 genlmsg_cancel(msg->skb, hdr);
1135
1136 return -EMSGSIZE;
1137 }
1138
1139 /**
1140 * tipc_node_xmit() is the general link level function for message sending
1141 * @net: the applicable net namespace
1142 * @list: chain of buffers containing message
1143 * @dnode: address of destination node
1144 * @selector: a number used for deterministic link selection
1145 * Consumes the buffer chain, except when returning -ELINKCONG
1146 * Returns 0 if success, otherwise: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE,-ENOBUF
1147 */
1148 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1149 u32 dnode, int selector)
1150 {
1151 struct tipc_link_entry *le = NULL;
1152 struct tipc_node *n;
1153 struct sk_buff_head xmitq;
1154 int bearer_id;
1155 int rc;
1156
1157 if (in_own_node(net, dnode)) {
1158 tipc_sk_rcv(net, list);
1159 return 0;
1160 }
1161
1162 n = tipc_node_find(net, dnode);
1163 if (unlikely(!n)) {
1164 skb_queue_purge(list);
1165 return -EHOSTUNREACH;
1166 }
1167
1168 tipc_node_read_lock(n);
1169 bearer_id = n->active_links[selector & 1];
1170 if (unlikely(bearer_id == INVALID_BEARER_ID)) {
1171 tipc_node_read_unlock(n);
1172 tipc_node_put(n);
1173 skb_queue_purge(list);
1174 return -EHOSTUNREACH;
1175 }
1176
1177 __skb_queue_head_init(&xmitq);
1178 le = &n->links[bearer_id];
1179 spin_lock_bh(&le->lock);
1180 rc = tipc_link_xmit(le->link, list, &xmitq);
1181 spin_unlock_bh(&le->lock);
1182 tipc_node_read_unlock(n);
1183
1184 if (likely(rc == 0))
1185 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1186 else if (rc == -ENOBUFS)
1187 tipc_node_link_down(n, bearer_id, false);
1188
1189 tipc_node_put(n);
1190
1191 return rc;
1192 }
1193
1194 /* tipc_node_xmit_skb(): send single buffer to destination
1195 * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1196 * messages, which will not be rejected
1197 * The only exception is datagram messages rerouted after secondary
1198 * lookup, which are rare and safe to dispose of anyway.
1199 * TODO: Return real return value, and let callers use
1200 * tipc_wait_for_sendpkt() where applicable
1201 */
1202 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1203 u32 selector)
1204 {
1205 struct sk_buff_head head;
1206 int rc;
1207
1208 skb_queue_head_init(&head);
1209 __skb_queue_tail(&head, skb);
1210 rc = tipc_node_xmit(net, &head, dnode, selector);
1211 if (rc == -ELINKCONG)
1212 kfree_skb(skb);
1213 return 0;
1214 }
1215
1216 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1217 {
1218 struct sk_buff *txskb;
1219 struct tipc_node *n;
1220 u32 dst;
1221
1222 rcu_read_lock();
1223 list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1224 dst = n->addr;
1225 if (in_own_node(net, dst))
1226 continue;
1227 if (!tipc_node_is_up(n))
1228 continue;
1229 txskb = pskb_copy(skb, GFP_ATOMIC);
1230 if (!txskb)
1231 break;
1232 msg_set_destnode(buf_msg(txskb), dst);
1233 tipc_node_xmit_skb(net, txskb, dst, 0);
1234 }
1235 rcu_read_unlock();
1236
1237 kfree_skb(skb);
1238 }
1239
1240 /**
1241 * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1242 * @net: the applicable net namespace
1243 * @skb: TIPC packet
1244 * @bearer_id: id of bearer message arrived on
1245 *
1246 * Invoked with no locks held.
1247 */
1248 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1249 {
1250 int rc;
1251 struct sk_buff_head xmitq;
1252 struct tipc_bclink_entry *be;
1253 struct tipc_link_entry *le;
1254 struct tipc_msg *hdr = buf_msg(skb);
1255 int usr = msg_user(hdr);
1256 u32 dnode = msg_destnode(hdr);
1257 struct tipc_node *n;
1258
1259 __skb_queue_head_init(&xmitq);
1260
1261 /* If NACK for other node, let rcv link for that node peek into it */
1262 if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1263 n = tipc_node_find(net, dnode);
1264 else
1265 n = tipc_node_find(net, msg_prevnode(hdr));
1266 if (!n) {
1267 kfree_skb(skb);
1268 return;
1269 }
1270 be = &n->bc_entry;
1271 le = &n->links[bearer_id];
1272
1273 rc = tipc_bcast_rcv(net, be->link, skb);
1274
1275 /* Broadcast link reset may happen at reassembly failure */
1276 if (rc & TIPC_LINK_DOWN_EVT)
1277 tipc_node_reset_links(n);
1278
1279 /* Broadcast ACKs are sent on a unicast link */
1280 if (rc & TIPC_LINK_SND_BC_ACK) {
1281 tipc_node_read_lock(n);
1282 tipc_link_build_ack_msg(le->link, &xmitq);
1283 tipc_node_read_unlock(n);
1284 }
1285
1286 if (!skb_queue_empty(&xmitq))
1287 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1288
1289 /* Deliver. 'arrvq' is under inputq2's lock protection */
1290 if (!skb_queue_empty(&be->inputq1)) {
1291 spin_lock_bh(&be->inputq2.lock);
1292 spin_lock_bh(&be->inputq1.lock);
1293 skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1294 spin_unlock_bh(&be->inputq1.lock);
1295 spin_unlock_bh(&be->inputq2.lock);
1296 tipc_sk_mcast_rcv(net, &be->arrvq, &be->inputq2);
1297 }
1298 tipc_node_put(n);
1299 }
1300
1301 /**
1302 * tipc_node_check_state - check and if necessary update node state
1303 * @skb: TIPC packet
1304 * @bearer_id: identity of bearer delivering the packet
1305 * Returns true if state is ok, otherwise consumes buffer and returns false
1306 */
1307 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1308 int bearer_id, struct sk_buff_head *xmitq)
1309 {
1310 struct tipc_msg *hdr = buf_msg(skb);
1311 int usr = msg_user(hdr);
1312 int mtyp = msg_type(hdr);
1313 u16 oseqno = msg_seqno(hdr);
1314 u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1315 u16 exp_pkts = msg_msgcnt(hdr);
1316 u16 rcv_nxt, syncpt, dlv_nxt, inputq_len;
1317 int state = n->state;
1318 struct tipc_link *l, *tnl, *pl = NULL;
1319 struct tipc_media_addr *maddr;
1320 int pb_id;
1321
1322 l = n->links[bearer_id].link;
1323 if (!l)
1324 return false;
1325 rcv_nxt = tipc_link_rcv_nxt(l);
1326
1327
1328 if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1329 return true;
1330
1331 /* Find parallel link, if any */
1332 for (pb_id = 0; pb_id < MAX_BEARERS; pb_id++) {
1333 if ((pb_id != bearer_id) && n->links[pb_id].link) {
1334 pl = n->links[pb_id].link;
1335 break;
1336 }
1337 }
1338
1339 /* Check and update node accesibility if applicable */
1340 if (state == SELF_UP_PEER_COMING) {
1341 if (!tipc_link_is_up(l))
1342 return true;
1343 if (!msg_peer_link_is_up(hdr))
1344 return true;
1345 tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1346 }
1347
1348 if (state == SELF_DOWN_PEER_LEAVING) {
1349 if (msg_peer_node_is_up(hdr))
1350 return false;
1351 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1352 return true;
1353 }
1354
1355 if (state == SELF_LEAVING_PEER_DOWN)
1356 return false;
1357
1358 /* Ignore duplicate packets */
1359 if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1360 return true;
1361
1362 /* Initiate or update failover mode if applicable */
1363 if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1364 syncpt = oseqno + exp_pkts - 1;
1365 if (pl && tipc_link_is_up(pl)) {
1366 __tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1367 tipc_skb_queue_splice_tail_init(tipc_link_inputq(pl),
1368 tipc_link_inputq(l));
1369 }
1370 /* If pkts arrive out of order, use lowest calculated syncpt */
1371 if (less(syncpt, n->sync_point))
1372 n->sync_point = syncpt;
1373 }
1374
1375 /* Open parallel link when tunnel link reaches synch point */
1376 if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1377 if (!more(rcv_nxt, n->sync_point))
1378 return true;
1379 tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1380 if (pl)
1381 tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1382 return true;
1383 }
1384
1385 /* No synching needed if only one link */
1386 if (!pl || !tipc_link_is_up(pl))
1387 return true;
1388
1389 /* Initiate synch mode if applicable */
1390 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1391 syncpt = iseqno + exp_pkts - 1;
1392 if (!tipc_link_is_up(l)) {
1393 tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
1394 __tipc_node_link_up(n, bearer_id, xmitq);
1395 }
1396 if (n->state == SELF_UP_PEER_UP) {
1397 n->sync_point = syncpt;
1398 tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1399 tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1400 }
1401 }
1402
1403 /* Open tunnel link when parallel link reaches synch point */
1404 if (n->state == NODE_SYNCHING) {
1405 if (tipc_link_is_synching(l)) {
1406 tnl = l;
1407 } else {
1408 tnl = pl;
1409 pl = l;
1410 }
1411 inputq_len = skb_queue_len(tipc_link_inputq(pl));
1412 dlv_nxt = tipc_link_rcv_nxt(pl) - inputq_len;
1413 if (more(dlv_nxt, n->sync_point)) {
1414 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1415 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1416 return true;
1417 }
1418 if (l == pl)
1419 return true;
1420 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1421 return true;
1422 if (usr == LINK_PROTOCOL)
1423 return true;
1424 return false;
1425 }
1426 return true;
1427 }
1428
1429 /**
1430 * tipc_rcv - process TIPC packets/messages arriving from off-node
1431 * @net: the applicable net namespace
1432 * @skb: TIPC packet
1433 * @bearer: pointer to bearer message arrived on
1434 *
1435 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1436 * structure (i.e. cannot be NULL), but bearer can be inactive.
1437 */
1438 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1439 {
1440 struct sk_buff_head xmitq;
1441 struct tipc_node *n;
1442 struct tipc_msg *hdr = buf_msg(skb);
1443 int usr = msg_user(hdr);
1444 int bearer_id = b->identity;
1445 struct tipc_link_entry *le;
1446 u16 bc_ack = msg_bcast_ack(hdr);
1447 int rc = 0;
1448
1449 __skb_queue_head_init(&xmitq);
1450
1451 /* Ensure message is well-formed */
1452 if (unlikely(!tipc_msg_validate(skb)))
1453 goto discard;
1454
1455 /* Handle arrival of discovery or broadcast packet */
1456 if (unlikely(msg_non_seq(hdr))) {
1457 if (unlikely(usr == LINK_CONFIG))
1458 return tipc_disc_rcv(net, skb, b);
1459 else
1460 return tipc_node_bc_rcv(net, skb, bearer_id);
1461 }
1462
1463 /* Locate neighboring node that sent packet */
1464 n = tipc_node_find(net, msg_prevnode(hdr));
1465 if (unlikely(!n))
1466 goto discard;
1467 le = &n->links[bearer_id];
1468
1469 /* Ensure broadcast reception is in synch with peer's send state */
1470 if (unlikely(usr == LINK_PROTOCOL))
1471 tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr);
1472 else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack))
1473 tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
1474
1475 /* Receive packet directly if conditions permit */
1476 tipc_node_read_lock(n);
1477 if (likely((n->state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL))) {
1478 spin_lock_bh(&le->lock);
1479 if (le->link) {
1480 rc = tipc_link_rcv(le->link, skb, &xmitq);
1481 skb = NULL;
1482 }
1483 spin_unlock_bh(&le->lock);
1484 }
1485 tipc_node_read_unlock(n);
1486
1487 /* Check/update node state before receiving */
1488 if (unlikely(skb)) {
1489 tipc_node_write_lock(n);
1490 if (tipc_node_check_state(n, skb, bearer_id, &xmitq)) {
1491 if (le->link) {
1492 rc = tipc_link_rcv(le->link, skb, &xmitq);
1493 skb = NULL;
1494 }
1495 }
1496 tipc_node_write_unlock(n);
1497 }
1498
1499 if (unlikely(rc & TIPC_LINK_UP_EVT))
1500 tipc_node_link_up(n, bearer_id, &xmitq);
1501
1502 if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1503 tipc_node_link_down(n, bearer_id, false);
1504
1505 if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1506 tipc_named_rcv(net, &n->bc_entry.namedq);
1507
1508 if (!skb_queue_empty(&le->inputq))
1509 tipc_sk_rcv(net, &le->inputq);
1510
1511 if (!skb_queue_empty(&xmitq))
1512 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1513
1514 tipc_node_put(n);
1515 discard:
1516 kfree_skb(skb);
1517 }
1518
1519 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1520 {
1521 int err;
1522 struct net *net = sock_net(skb->sk);
1523 struct tipc_net *tn = net_generic(net, tipc_net_id);
1524 int done = cb->args[0];
1525 int last_addr = cb->args[1];
1526 struct tipc_node *node;
1527 struct tipc_nl_msg msg;
1528
1529 if (done)
1530 return 0;
1531
1532 msg.skb = skb;
1533 msg.portid = NETLINK_CB(cb->skb).portid;
1534 msg.seq = cb->nlh->nlmsg_seq;
1535
1536 rcu_read_lock();
1537 if (last_addr) {
1538 node = tipc_node_find(net, last_addr);
1539 if (!node) {
1540 rcu_read_unlock();
1541 /* We never set seq or call nl_dump_check_consistent()
1542 * this means that setting prev_seq here will cause the
1543 * consistence check to fail in the netlink callback
1544 * handler. Resulting in the NLMSG_DONE message having
1545 * the NLM_F_DUMP_INTR flag set if the node state
1546 * changed while we released the lock.
1547 */
1548 cb->prev_seq = 1;
1549 return -EPIPE;
1550 }
1551 tipc_node_put(node);
1552 }
1553
1554 list_for_each_entry_rcu(node, &tn->node_list, list) {
1555 if (last_addr) {
1556 if (node->addr == last_addr)
1557 last_addr = 0;
1558 else
1559 continue;
1560 }
1561
1562 tipc_node_read_lock(node);
1563 err = __tipc_nl_add_node(&msg, node);
1564 if (err) {
1565 last_addr = node->addr;
1566 tipc_node_read_unlock(node);
1567 goto out;
1568 }
1569
1570 tipc_node_read_unlock(node);
1571 }
1572 done = 1;
1573 out:
1574 cb->args[0] = done;
1575 cb->args[1] = last_addr;
1576 rcu_read_unlock();
1577
1578 return skb->len;
1579 }
1580
1581 /* tipc_node_find_by_name - locate owner node of link by link's name
1582 * @net: the applicable net namespace
1583 * @name: pointer to link name string
1584 * @bearer_id: pointer to index in 'node->links' array where the link was found.
1585 *
1586 * Returns pointer to node owning the link, or 0 if no matching link is found.
1587 */
1588 static struct tipc_node *tipc_node_find_by_name(struct net *net,
1589 const char *link_name,
1590 unsigned int *bearer_id)
1591 {
1592 struct tipc_net *tn = net_generic(net, tipc_net_id);
1593 struct tipc_link *l;
1594 struct tipc_node *n;
1595 struct tipc_node *found_node = NULL;
1596 int i;
1597
1598 *bearer_id = 0;
1599 rcu_read_lock();
1600 list_for_each_entry_rcu(n, &tn->node_list, list) {
1601 tipc_node_read_lock(n);
1602 for (i = 0; i < MAX_BEARERS; i++) {
1603 l = n->links[i].link;
1604 if (l && !strcmp(tipc_link_name(l), link_name)) {
1605 *bearer_id = i;
1606 found_node = n;
1607 break;
1608 }
1609 }
1610 tipc_node_read_unlock(n);
1611 if (found_node)
1612 break;
1613 }
1614 rcu_read_unlock();
1615
1616 return found_node;
1617 }
1618
1619 int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
1620 {
1621 int err;
1622 int res = 0;
1623 int bearer_id;
1624 char *name;
1625 struct tipc_link *link;
1626 struct tipc_node *node;
1627 struct sk_buff_head xmitq;
1628 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1629 struct net *net = sock_net(skb->sk);
1630
1631 __skb_queue_head_init(&xmitq);
1632
1633 if (!info->attrs[TIPC_NLA_LINK])
1634 return -EINVAL;
1635
1636 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1637 info->attrs[TIPC_NLA_LINK],
1638 tipc_nl_link_policy);
1639 if (err)
1640 return err;
1641
1642 if (!attrs[TIPC_NLA_LINK_NAME])
1643 return -EINVAL;
1644
1645 name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1646
1647 if (strcmp(name, tipc_bclink_name) == 0)
1648 return tipc_nl_bc_link_set(net, attrs);
1649
1650 node = tipc_node_find_by_name(net, name, &bearer_id);
1651 if (!node)
1652 return -EINVAL;
1653
1654 tipc_node_read_lock(node);
1655
1656 link = node->links[bearer_id].link;
1657 if (!link) {
1658 res = -EINVAL;
1659 goto out;
1660 }
1661
1662 if (attrs[TIPC_NLA_LINK_PROP]) {
1663 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1664
1665 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1666 props);
1667 if (err) {
1668 res = err;
1669 goto out;
1670 }
1671
1672 if (props[TIPC_NLA_PROP_TOL]) {
1673 u32 tol;
1674
1675 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1676 tipc_link_set_tolerance(link, tol, &xmitq);
1677 }
1678 if (props[TIPC_NLA_PROP_PRIO]) {
1679 u32 prio;
1680
1681 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1682 tipc_link_set_prio(link, prio, &xmitq);
1683 }
1684 if (props[TIPC_NLA_PROP_WIN]) {
1685 u32 win;
1686
1687 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1688 tipc_link_set_queue_limits(link, win);
1689 }
1690 }
1691
1692 out:
1693 tipc_node_read_unlock(node);
1694 tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
1695 return res;
1696 }
1697
1698 int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
1699 {
1700 struct net *net = genl_info_net(info);
1701 struct tipc_nl_msg msg;
1702 char *name;
1703 int err;
1704
1705 msg.portid = info->snd_portid;
1706 msg.seq = info->snd_seq;
1707
1708 if (!info->attrs[TIPC_NLA_LINK_NAME])
1709 return -EINVAL;
1710 name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
1711
1712 msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1713 if (!msg.skb)
1714 return -ENOMEM;
1715
1716 if (strcmp(name, tipc_bclink_name) == 0) {
1717 err = tipc_nl_add_bc_link(net, &msg);
1718 if (err) {
1719 nlmsg_free(msg.skb);
1720 return err;
1721 }
1722 } else {
1723 int bearer_id;
1724 struct tipc_node *node;
1725 struct tipc_link *link;
1726
1727 node = tipc_node_find_by_name(net, name, &bearer_id);
1728 if (!node)
1729 return -EINVAL;
1730
1731 tipc_node_read_lock(node);
1732 link = node->links[bearer_id].link;
1733 if (!link) {
1734 tipc_node_read_unlock(node);
1735 nlmsg_free(msg.skb);
1736 return -EINVAL;
1737 }
1738
1739 err = __tipc_nl_add_link(net, &msg, link, 0);
1740 tipc_node_read_unlock(node);
1741 if (err) {
1742 nlmsg_free(msg.skb);
1743 return err;
1744 }
1745 }
1746
1747 return genlmsg_reply(msg.skb, info);
1748 }
1749
1750 int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
1751 {
1752 int err;
1753 char *link_name;
1754 unsigned int bearer_id;
1755 struct tipc_link *link;
1756 struct tipc_node *node;
1757 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1758 struct net *net = sock_net(skb->sk);
1759 struct tipc_link_entry *le;
1760
1761 if (!info->attrs[TIPC_NLA_LINK])
1762 return -EINVAL;
1763
1764 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1765 info->attrs[TIPC_NLA_LINK],
1766 tipc_nl_link_policy);
1767 if (err)
1768 return err;
1769
1770 if (!attrs[TIPC_NLA_LINK_NAME])
1771 return -EINVAL;
1772
1773 link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1774
1775 if (strcmp(link_name, tipc_bclink_name) == 0) {
1776 err = tipc_bclink_reset_stats(net);
1777 if (err)
1778 return err;
1779 return 0;
1780 }
1781
1782 node = tipc_node_find_by_name(net, link_name, &bearer_id);
1783 if (!node)
1784 return -EINVAL;
1785
1786 le = &node->links[bearer_id];
1787 tipc_node_read_lock(node);
1788 spin_lock_bh(&le->lock);
1789 link = node->links[bearer_id].link;
1790 if (!link) {
1791 spin_unlock_bh(&le->lock);
1792 tipc_node_read_unlock(node);
1793 return -EINVAL;
1794 }
1795 tipc_link_reset_stats(link);
1796 spin_unlock_bh(&le->lock);
1797 tipc_node_read_unlock(node);
1798 return 0;
1799 }
1800
1801 /* Caller should hold node lock */
1802 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1803 struct tipc_node *node, u32 *prev_link)
1804 {
1805 u32 i;
1806 int err;
1807
1808 for (i = *prev_link; i < MAX_BEARERS; i++) {
1809 *prev_link = i;
1810
1811 if (!node->links[i].link)
1812 continue;
1813
1814 err = __tipc_nl_add_link(net, msg,
1815 node->links[i].link, NLM_F_MULTI);
1816 if (err)
1817 return err;
1818 }
1819 *prev_link = 0;
1820
1821 return 0;
1822 }
1823
1824 int tipc_nl_node_dump_link(struct sk_buff *skb, struct netlink_callback *cb)
1825 {
1826 struct net *net = sock_net(skb->sk);
1827 struct tipc_net *tn = net_generic(net, tipc_net_id);
1828 struct tipc_node *node;
1829 struct tipc_nl_msg msg;
1830 u32 prev_node = cb->args[0];
1831 u32 prev_link = cb->args[1];
1832 int done = cb->args[2];
1833 int err;
1834
1835 if (done)
1836 return 0;
1837
1838 msg.skb = skb;
1839 msg.portid = NETLINK_CB(cb->skb).portid;
1840 msg.seq = cb->nlh->nlmsg_seq;
1841
1842 rcu_read_lock();
1843 if (prev_node) {
1844 node = tipc_node_find(net, prev_node);
1845 if (!node) {
1846 /* We never set seq or call nl_dump_check_consistent()
1847 * this means that setting prev_seq here will cause the
1848 * consistence check to fail in the netlink callback
1849 * handler. Resulting in the last NLMSG_DONE message
1850 * having the NLM_F_DUMP_INTR flag set.
1851 */
1852 cb->prev_seq = 1;
1853 goto out;
1854 }
1855 tipc_node_put(node);
1856
1857 list_for_each_entry_continue_rcu(node, &tn->node_list,
1858 list) {
1859 tipc_node_read_lock(node);
1860 err = __tipc_nl_add_node_links(net, &msg, node,
1861 &prev_link);
1862 tipc_node_read_unlock(node);
1863 if (err)
1864 goto out;
1865
1866 prev_node = node->addr;
1867 }
1868 } else {
1869 err = tipc_nl_add_bc_link(net, &msg);
1870 if (err)
1871 goto out;
1872
1873 list_for_each_entry_rcu(node, &tn->node_list, list) {
1874 tipc_node_read_lock(node);
1875 err = __tipc_nl_add_node_links(net, &msg, node,
1876 &prev_link);
1877 tipc_node_read_unlock(node);
1878 if (err)
1879 goto out;
1880
1881 prev_node = node->addr;
1882 }
1883 }
1884 done = 1;
1885 out:
1886 rcu_read_unlock();
1887
1888 cb->args[0] = prev_node;
1889 cb->args[1] = prev_link;
1890 cb->args[2] = done;
1891
1892 return skb->len;
1893 }
Linux with added FPC-III support