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tipc: reduce code dependency between binding table and node layer
[mirror_ubuntu-zesty-kernel.git] / net / tipc / node.c
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
45 /* Node FSM states and events:
46 */
47 enum {
48 SELF_DOWN_PEER_DOWN = 0xdd,
49 SELF_UP_PEER_UP = 0xaa,
50 SELF_DOWN_PEER_LEAVING = 0xd1,
51 SELF_UP_PEER_COMING = 0xac,
52 SELF_COMING_PEER_UP = 0xca,
53 SELF_LEAVING_PEER_DOWN = 0x1d,
54 NODE_FAILINGOVER = 0xf0,
55 NODE_SYNCHING = 0xcc
56 };
57
58 enum {
59 SELF_ESTABL_CONTACT_EVT = 0xece,
60 SELF_LOST_CONTACT_EVT = 0x1ce,
61 PEER_ESTABL_CONTACT_EVT = 0x9ece,
62 PEER_LOST_CONTACT_EVT = 0x91ce,
63 NODE_FAILOVER_BEGIN_EVT = 0xfbe,
64 NODE_FAILOVER_END_EVT = 0xfee,
65 NODE_SYNCH_BEGIN_EVT = 0xcbe,
66 NODE_SYNCH_END_EVT = 0xcee
67 };
68
69 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
70 struct sk_buff_head *xmitq,
71 struct tipc_media_addr **maddr);
72 static void tipc_node_link_down(struct tipc_node *n, int bearer_id,
73 bool delete);
74 static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
75 static void tipc_node_delete(struct tipc_node *node);
76 static void tipc_node_timeout(unsigned long data);
77 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
78
79 struct tipc_sock_conn {
80 u32 port;
81 u32 peer_port;
82 u32 peer_node;
83 struct list_head list;
84 };
85
86 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = {
87 [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC },
88 [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 },
89 [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG }
90 };
91
92 /*
93 * A trivial power-of-two bitmask technique is used for speed, since this
94 * operation is done for every incoming TIPC packet. The number of hash table
95 * entries has been chosen so that no hash chain exceeds 8 nodes and will
96 * usually be much smaller (typically only a single node).
97 */
98 static unsigned int tipc_hashfn(u32 addr)
99 {
100 return addr & (NODE_HTABLE_SIZE - 1);
101 }
102
103 static void tipc_node_kref_release(struct kref *kref)
104 {
105 struct tipc_node *node = container_of(kref, struct tipc_node, kref);
106
107 tipc_node_delete(node);
108 }
109
110 void tipc_node_put(struct tipc_node *node)
111 {
112 kref_put(&node->kref, tipc_node_kref_release);
113 }
114
115 static void tipc_node_get(struct tipc_node *node)
116 {
117 kref_get(&node->kref);
118 }
119
120 /*
121 * tipc_node_find - locate specified node object, if it exists
122 */
123 struct tipc_node *tipc_node_find(struct net *net, u32 addr)
124 {
125 struct tipc_net *tn = net_generic(net, tipc_net_id);
126 struct tipc_node *node;
127
128 if (unlikely(!in_own_cluster_exact(net, addr)))
129 return NULL;
130
131 rcu_read_lock();
132 hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)],
133 hash) {
134 if (node->addr == addr) {
135 tipc_node_get(node);
136 rcu_read_unlock();
137 return node;
138 }
139 }
140 rcu_read_unlock();
141 return NULL;
142 }
143
144 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
145 {
146 struct tipc_net *tn = net_generic(net, tipc_net_id);
147 struct tipc_node *n_ptr, *temp_node;
148
149 spin_lock_bh(&tn->node_list_lock);
150 n_ptr = tipc_node_find(net, addr);
151 if (n_ptr)
152 goto exit;
153 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
154 if (!n_ptr) {
155 pr_warn("Node creation failed, no memory\n");
156 goto exit;
157 }
158 n_ptr->addr = addr;
159 n_ptr->net = net;
160 n_ptr->capabilities = capabilities;
161 kref_init(&n_ptr->kref);
162 spin_lock_init(&n_ptr->lock);
163 INIT_HLIST_NODE(&n_ptr->hash);
164 INIT_LIST_HEAD(&n_ptr->list);
165 INIT_LIST_HEAD(&n_ptr->publ_list);
166 INIT_LIST_HEAD(&n_ptr->conn_sks);
167 skb_queue_head_init(&n_ptr->bc_entry.namedq);
168 skb_queue_head_init(&n_ptr->bc_entry.inputq1);
169 __skb_queue_head_init(&n_ptr->bc_entry.arrvq);
170 skb_queue_head_init(&n_ptr->bc_entry.inputq2);
171 hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
172 list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
173 if (n_ptr->addr < temp_node->addr)
174 break;
175 }
176 list_add_tail_rcu(&n_ptr->list, &temp_node->list);
177 n_ptr->state = SELF_DOWN_PEER_LEAVING;
178 n_ptr->signature = INVALID_NODE_SIG;
179 n_ptr->active_links[0] = INVALID_BEARER_ID;
180 n_ptr->active_links[1] = INVALID_BEARER_ID;
181 if (!tipc_link_bc_create(net, tipc_own_addr(net), n_ptr->addr,
182 U16_MAX, tipc_bc_sndlink(net)->window,
183 n_ptr->capabilities,
184 &n_ptr->bc_entry.inputq1,
185 &n_ptr->bc_entry.namedq,
186 tipc_bc_sndlink(net),
187 &n_ptr->bc_entry.link)) {
188 pr_warn("Broadcast rcv link creation failed, no memory\n");
189 kfree(n_ptr);
190 n_ptr = NULL;
191 goto exit;
192 }
193 tipc_node_get(n_ptr);
194 setup_timer(&n_ptr->timer, tipc_node_timeout, (unsigned long)n_ptr);
195 n_ptr->keepalive_intv = U32_MAX;
196 exit:
197 spin_unlock_bh(&tn->node_list_lock);
198 return n_ptr;
199 }
200
201 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
202 {
203 unsigned long tol = l->tolerance;
204 unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
205 unsigned long keepalive_intv = msecs_to_jiffies(intv);
206
207 /* Link with lowest tolerance determines timer interval */
208 if (keepalive_intv < n->keepalive_intv)
209 n->keepalive_intv = keepalive_intv;
210
211 /* Ensure link's abort limit corresponds to current interval */
212 l->abort_limit = l->tolerance / jiffies_to_msecs(n->keepalive_intv);
213 }
214
215 static void tipc_node_delete(struct tipc_node *node)
216 {
217 list_del_rcu(&node->list);
218 hlist_del_rcu(&node->hash);
219 kfree(node->bc_entry.link);
220 kfree_rcu(node, rcu);
221 }
222
223 void tipc_node_stop(struct net *net)
224 {
225 struct tipc_net *tn = net_generic(net, tipc_net_id);
226 struct tipc_node *node, *t_node;
227
228 spin_lock_bh(&tn->node_list_lock);
229 list_for_each_entry_safe(node, t_node, &tn->node_list, list) {
230 if (del_timer(&node->timer))
231 tipc_node_put(node);
232 tipc_node_put(node);
233 }
234 spin_unlock_bh(&tn->node_list_lock);
235 }
236
237 void tipc_node_subscribe(struct net *net, struct list_head *subscr, u32 addr)
238 {
239 struct tipc_node *n;
240
241 if (in_own_node(net, addr))
242 return;
243
244 n = tipc_node_find(net, addr);
245 if (!n) {
246 pr_warn("Node subscribe rejected, unknown node 0x%x\n", addr);
247 return;
248 }
249 tipc_node_lock(n);
250 list_add_tail(subscr, &n->publ_list);
251 tipc_node_unlock(n);
252 tipc_node_put(n);
253 }
254
255 void tipc_node_unsubscribe(struct net *net, struct list_head *subscr, u32 addr)
256 {
257 struct tipc_node *n;
258
259 if (in_own_node(net, addr))
260 return;
261
262 n = tipc_node_find(net, addr);
263 if (!n) {
264 pr_warn("Node unsubscribe rejected, unknown node 0x%x\n", addr);
265 return;
266 }
267 tipc_node_lock(n);
268 list_del_init(subscr);
269 tipc_node_unlock(n);
270 tipc_node_put(n);
271 }
272
273 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
274 {
275 struct tipc_node *node;
276 struct tipc_sock_conn *conn;
277 int err = 0;
278
279 if (in_own_node(net, dnode))
280 return 0;
281
282 node = tipc_node_find(net, dnode);
283 if (!node) {
284 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
285 return -EHOSTUNREACH;
286 }
287 conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
288 if (!conn) {
289 err = -EHOSTUNREACH;
290 goto exit;
291 }
292 conn->peer_node = dnode;
293 conn->port = port;
294 conn->peer_port = peer_port;
295
296 tipc_node_lock(node);
297 list_add_tail(&conn->list, &node->conn_sks);
298 tipc_node_unlock(node);
299 exit:
300 tipc_node_put(node);
301 return err;
302 }
303
304 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
305 {
306 struct tipc_node *node;
307 struct tipc_sock_conn *conn, *safe;
308
309 if (in_own_node(net, dnode))
310 return;
311
312 node = tipc_node_find(net, dnode);
313 if (!node)
314 return;
315
316 tipc_node_lock(node);
317 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
318 if (port != conn->port)
319 continue;
320 list_del(&conn->list);
321 kfree(conn);
322 }
323 tipc_node_unlock(node);
324 tipc_node_put(node);
325 }
326
327 /* tipc_node_timeout - handle expiration of node timer
328 */
329 static void tipc_node_timeout(unsigned long data)
330 {
331 struct tipc_node *n = (struct tipc_node *)data;
332 struct tipc_link_entry *le;
333 struct sk_buff_head xmitq;
334 int bearer_id;
335 int rc = 0;
336
337 __skb_queue_head_init(&xmitq);
338
339 for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
340 tipc_node_lock(n);
341 le = &n->links[bearer_id];
342 if (le->link) {
343 /* Link tolerance may change asynchronously: */
344 tipc_node_calculate_timer(n, le->link);
345 rc = tipc_link_timeout(le->link, &xmitq);
346 }
347 tipc_node_unlock(n);
348 tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
349 if (rc & TIPC_LINK_DOWN_EVT)
350 tipc_node_link_down(n, bearer_id, false);
351 }
352 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
353 tipc_node_get(n);
354 tipc_node_put(n);
355 }
356
357 /**
358 * __tipc_node_link_up - handle addition of link
359 * Node lock must be held by caller
360 * Link becomes active (alone or shared) or standby, depending on its priority.
361 */
362 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
363 struct sk_buff_head *xmitq)
364 {
365 int *slot0 = &n->active_links[0];
366 int *slot1 = &n->active_links[1];
367 struct tipc_link *ol = node_active_link(n, 0);
368 struct tipc_link *nl = n->links[bearer_id].link;
369
370 if (!nl)
371 return;
372
373 tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
374 if (!tipc_link_is_up(nl))
375 return;
376
377 n->working_links++;
378 n->action_flags |= TIPC_NOTIFY_LINK_UP;
379 n->link_id = nl->peer_bearer_id << 16 | bearer_id;
380
381 /* Leave room for tunnel header when returning 'mtu' to users: */
382 n->links[bearer_id].mtu = nl->mtu - INT_H_SIZE;
383
384 tipc_bearer_add_dest(n->net, bearer_id, n->addr);
385 tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
386
387 pr_debug("Established link <%s> on network plane %c\n",
388 nl->name, nl->net_plane);
389
390 /* First link? => give it both slots */
391 if (!ol) {
392 *slot0 = bearer_id;
393 *slot1 = bearer_id;
394 tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
395 n->action_flags |= TIPC_NOTIFY_NODE_UP;
396 tipc_bcast_add_peer(n->net, nl, xmitq);
397 return;
398 }
399
400 /* Second link => redistribute slots */
401 if (nl->priority > ol->priority) {
402 pr_debug("Old link <%s> becomes standby\n", ol->name);
403 *slot0 = bearer_id;
404 *slot1 = bearer_id;
405 tipc_link_set_active(nl, true);
406 tipc_link_set_active(ol, false);
407 } else if (nl->priority == ol->priority) {
408 tipc_link_set_active(nl, true);
409 *slot1 = bearer_id;
410 } else {
411 pr_debug("New link <%s> is standby\n", nl->name);
412 }
413
414 /* Prepare synchronization with first link */
415 tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
416 }
417
418 /**
419 * tipc_node_link_up - handle addition of link
420 *
421 * Link becomes active (alone or shared) or standby, depending on its priority.
422 */
423 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
424 struct sk_buff_head *xmitq)
425 {
426 tipc_node_lock(n);
427 __tipc_node_link_up(n, bearer_id, xmitq);
428 tipc_node_unlock(n);
429 }
430
431 /**
432 * __tipc_node_link_down - handle loss of link
433 */
434 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
435 struct sk_buff_head *xmitq,
436 struct tipc_media_addr **maddr)
437 {
438 struct tipc_link_entry *le = &n->links[*bearer_id];
439 int *slot0 = &n->active_links[0];
440 int *slot1 = &n->active_links[1];
441 int i, highest = 0;
442 struct tipc_link *l, *_l, *tnl;
443
444 l = n->links[*bearer_id].link;
445 if (!l || tipc_link_is_reset(l))
446 return;
447
448 n->working_links--;
449 n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
450 n->link_id = l->peer_bearer_id << 16 | *bearer_id;
451
452 tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
453
454 pr_debug("Lost link <%s> on network plane %c\n",
455 l->name, l->net_plane);
456
457 /* Select new active link if any available */
458 *slot0 = INVALID_BEARER_ID;
459 *slot1 = INVALID_BEARER_ID;
460 for (i = 0; i < MAX_BEARERS; i++) {
461 _l = n->links[i].link;
462 if (!_l || !tipc_link_is_up(_l))
463 continue;
464 if (_l == l)
465 continue;
466 if (_l->priority < highest)
467 continue;
468 if (_l->priority > highest) {
469 highest = _l->priority;
470 *slot0 = i;
471 *slot1 = i;
472 continue;
473 }
474 *slot1 = i;
475 }
476
477 if (!tipc_node_is_up(n)) {
478 if (tipc_link_peer_is_down(l))
479 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
480 tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
481 tipc_link_fsm_evt(l, LINK_RESET_EVT);
482 tipc_link_reset(l);
483 tipc_link_build_reset_msg(l, xmitq);
484 *maddr = &n->links[*bearer_id].maddr;
485 node_lost_contact(n, &le->inputq);
486 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
487 return;
488 }
489 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
490
491 /* There is still a working link => initiate failover */
492 tnl = node_active_link(n, 0);
493 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
494 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
495 n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
496 tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
497 tipc_link_reset(l);
498 tipc_link_fsm_evt(l, LINK_RESET_EVT);
499 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
500 tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
501 *maddr = &n->links[tnl->bearer_id].maddr;
502 *bearer_id = tnl->bearer_id;
503 }
504
505 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
506 {
507 struct tipc_link_entry *le = &n->links[bearer_id];
508 struct tipc_link *l = le->link;
509 struct tipc_media_addr *maddr;
510 struct sk_buff_head xmitq;
511
512 if (!l)
513 return;
514
515 __skb_queue_head_init(&xmitq);
516
517 tipc_node_lock(n);
518 if (!tipc_link_is_establishing(l)) {
519 __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
520 if (delete) {
521 kfree(l);
522 le->link = NULL;
523 n->link_cnt--;
524 }
525 } else {
526 /* Defuse pending tipc_node_link_up() */
527 tipc_link_fsm_evt(l, LINK_RESET_EVT);
528 }
529 tipc_node_unlock(n);
530 tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
531 tipc_sk_rcv(n->net, &le->inputq);
532 }
533
534 bool tipc_node_is_up(struct tipc_node *n)
535 {
536 return n->active_links[0] != INVALID_BEARER_ID;
537 }
538
539 void tipc_node_check_dest(struct net *net, u32 onode,
540 struct tipc_bearer *b,
541 u16 capabilities, u32 signature,
542 struct tipc_media_addr *maddr,
543 bool *respond, bool *dupl_addr)
544 {
545 struct tipc_node *n;
546 struct tipc_link *l;
547 struct tipc_link_entry *le;
548 bool addr_match = false;
549 bool sign_match = false;
550 bool link_up = false;
551 bool accept_addr = false;
552 bool reset = true;
553 char *if_name;
554
555 *dupl_addr = false;
556 *respond = false;
557
558 n = tipc_node_create(net, onode, capabilities);
559 if (!n)
560 return;
561
562 tipc_node_lock(n);
563
564 le = &n->links[b->identity];
565
566 /* Prepare to validate requesting node's signature and media address */
567 l = le->link;
568 link_up = l && tipc_link_is_up(l);
569 addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
570 sign_match = (signature == n->signature);
571
572 /* These three flags give us eight permutations: */
573
574 if (sign_match && addr_match && link_up) {
575 /* All is fine. Do nothing. */
576 reset = false;
577 } else if (sign_match && addr_match && !link_up) {
578 /* Respond. The link will come up in due time */
579 *respond = true;
580 } else if (sign_match && !addr_match && link_up) {
581 /* Peer has changed i/f address without rebooting.
582 * If so, the link will reset soon, and the next
583 * discovery will be accepted. So we can ignore it.
584 * It may also be an cloned or malicious peer having
585 * chosen the same node address and signature as an
586 * existing one.
587 * Ignore requests until the link goes down, if ever.
588 */
589 *dupl_addr = true;
590 } else if (sign_match && !addr_match && !link_up) {
591 /* Peer link has changed i/f address without rebooting.
592 * It may also be a cloned or malicious peer; we can't
593 * distinguish between the two.
594 * The signature is correct, so we must accept.
595 */
596 accept_addr = true;
597 *respond = true;
598 } else if (!sign_match && addr_match && link_up) {
599 /* Peer node rebooted. Two possibilities:
600 * - Delayed re-discovery; this link endpoint has already
601 * reset and re-established contact with the peer, before
602 * receiving a discovery message from that node.
603 * (The peer happened to receive one from this node first).
604 * - The peer came back so fast that our side has not
605 * discovered it yet. Probing from this side will soon
606 * reset the link, since there can be no working link
607 * endpoint at the peer end, and the link will re-establish.
608 * Accept the signature, since it comes from a known peer.
609 */
610 n->signature = signature;
611 } else if (!sign_match && addr_match && !link_up) {
612 /* The peer node has rebooted.
613 * Accept signature, since it is a known peer.
614 */
615 n->signature = signature;
616 *respond = true;
617 } else if (!sign_match && !addr_match && link_up) {
618 /* Peer rebooted with new address, or a new/duplicate peer.
619 * Ignore until the link goes down, if ever.
620 */
621 *dupl_addr = true;
622 } else if (!sign_match && !addr_match && !link_up) {
623 /* Peer rebooted with new address, or it is a new peer.
624 * Accept signature and address.
625 */
626 n->signature = signature;
627 accept_addr = true;
628 *respond = true;
629 }
630
631 if (!accept_addr)
632 goto exit;
633
634 /* Now create new link if not already existing */
635 if (!l) {
636 if (n->link_cnt == 2) {
637 pr_warn("Cannot establish 3rd link to %x\n", n->addr);
638 goto exit;
639 }
640 if_name = strchr(b->name, ':') + 1;
641 if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
642 b->net_plane, b->mtu, b->priority,
643 b->window, mod(tipc_net(net)->random),
644 tipc_own_addr(net), onode,
645 n->capabilities,
646 tipc_bc_sndlink(n->net), n->bc_entry.link,
647 &le->inputq,
648 &n->bc_entry.namedq, &l)) {
649 *respond = false;
650 goto exit;
651 }
652 tipc_link_reset(l);
653 tipc_link_fsm_evt(l, LINK_RESET_EVT);
654 if (n->state == NODE_FAILINGOVER)
655 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
656 le->link = l;
657 n->link_cnt++;
658 tipc_node_calculate_timer(n, l);
659 if (n->link_cnt == 1)
660 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
661 tipc_node_get(n);
662 }
663 memcpy(&le->maddr, maddr, sizeof(*maddr));
664 exit:
665 tipc_node_unlock(n);
666 if (reset && !tipc_link_is_reset(l))
667 tipc_node_link_down(n, b->identity, false);
668 tipc_node_put(n);
669 }
670
671 void tipc_node_delete_links(struct net *net, int bearer_id)
672 {
673 struct tipc_net *tn = net_generic(net, tipc_net_id);
674 struct tipc_node *n;
675
676 rcu_read_lock();
677 list_for_each_entry_rcu(n, &tn->node_list, list) {
678 tipc_node_link_down(n, bearer_id, true);
679 }
680 rcu_read_unlock();
681 }
682
683 static void tipc_node_reset_links(struct tipc_node *n)
684 {
685 char addr_string[16];
686 int i;
687
688 pr_warn("Resetting all links to %s\n",
689 tipc_addr_string_fill(addr_string, n->addr));
690
691 for (i = 0; i < MAX_BEARERS; i++) {
692 tipc_node_link_down(n, i, false);
693 }
694 }
695
696 /* tipc_node_fsm_evt - node finite state machine
697 * Determines when contact is allowed with peer node
698 */
699 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
700 {
701 int state = n->state;
702
703 switch (state) {
704 case SELF_DOWN_PEER_DOWN:
705 switch (evt) {
706 case SELF_ESTABL_CONTACT_EVT:
707 state = SELF_UP_PEER_COMING;
708 break;
709 case PEER_ESTABL_CONTACT_EVT:
710 state = SELF_COMING_PEER_UP;
711 break;
712 case SELF_LOST_CONTACT_EVT:
713 case PEER_LOST_CONTACT_EVT:
714 break;
715 case NODE_SYNCH_END_EVT:
716 case NODE_SYNCH_BEGIN_EVT:
717 case NODE_FAILOVER_BEGIN_EVT:
718 case NODE_FAILOVER_END_EVT:
719 default:
720 goto illegal_evt;
721 }
722 break;
723 case SELF_UP_PEER_UP:
724 switch (evt) {
725 case SELF_LOST_CONTACT_EVT:
726 state = SELF_DOWN_PEER_LEAVING;
727 break;
728 case PEER_LOST_CONTACT_EVT:
729 state = SELF_LEAVING_PEER_DOWN;
730 break;
731 case NODE_SYNCH_BEGIN_EVT:
732 state = NODE_SYNCHING;
733 break;
734 case NODE_FAILOVER_BEGIN_EVT:
735 state = NODE_FAILINGOVER;
736 break;
737 case SELF_ESTABL_CONTACT_EVT:
738 case PEER_ESTABL_CONTACT_EVT:
739 case NODE_SYNCH_END_EVT:
740 case NODE_FAILOVER_END_EVT:
741 break;
742 default:
743 goto illegal_evt;
744 }
745 break;
746 case SELF_DOWN_PEER_LEAVING:
747 switch (evt) {
748 case PEER_LOST_CONTACT_EVT:
749 state = SELF_DOWN_PEER_DOWN;
750 break;
751 case SELF_ESTABL_CONTACT_EVT:
752 case PEER_ESTABL_CONTACT_EVT:
753 case SELF_LOST_CONTACT_EVT:
754 break;
755 case NODE_SYNCH_END_EVT:
756 case NODE_SYNCH_BEGIN_EVT:
757 case NODE_FAILOVER_BEGIN_EVT:
758 case NODE_FAILOVER_END_EVT:
759 default:
760 goto illegal_evt;
761 }
762 break;
763 case SELF_UP_PEER_COMING:
764 switch (evt) {
765 case PEER_ESTABL_CONTACT_EVT:
766 state = SELF_UP_PEER_UP;
767 break;
768 case SELF_LOST_CONTACT_EVT:
769 state = SELF_DOWN_PEER_LEAVING;
770 break;
771 case SELF_ESTABL_CONTACT_EVT:
772 case PEER_LOST_CONTACT_EVT:
773 case NODE_SYNCH_END_EVT:
774 case NODE_FAILOVER_BEGIN_EVT:
775 break;
776 case NODE_SYNCH_BEGIN_EVT:
777 case NODE_FAILOVER_END_EVT:
778 default:
779 goto illegal_evt;
780 }
781 break;
782 case SELF_COMING_PEER_UP:
783 switch (evt) {
784 case SELF_ESTABL_CONTACT_EVT:
785 state = SELF_UP_PEER_UP;
786 break;
787 case PEER_LOST_CONTACT_EVT:
788 state = SELF_LEAVING_PEER_DOWN;
789 break;
790 case SELF_LOST_CONTACT_EVT:
791 case PEER_ESTABL_CONTACT_EVT:
792 break;
793 case NODE_SYNCH_END_EVT:
794 case NODE_SYNCH_BEGIN_EVT:
795 case NODE_FAILOVER_BEGIN_EVT:
796 case NODE_FAILOVER_END_EVT:
797 default:
798 goto illegal_evt;
799 }
800 break;
801 case SELF_LEAVING_PEER_DOWN:
802 switch (evt) {
803 case SELF_LOST_CONTACT_EVT:
804 state = SELF_DOWN_PEER_DOWN;
805 break;
806 case SELF_ESTABL_CONTACT_EVT:
807 case PEER_ESTABL_CONTACT_EVT:
808 case PEER_LOST_CONTACT_EVT:
809 break;
810 case NODE_SYNCH_END_EVT:
811 case NODE_SYNCH_BEGIN_EVT:
812 case NODE_FAILOVER_BEGIN_EVT:
813 case NODE_FAILOVER_END_EVT:
814 default:
815 goto illegal_evt;
816 }
817 break;
818 case NODE_FAILINGOVER:
819 switch (evt) {
820 case SELF_LOST_CONTACT_EVT:
821 state = SELF_DOWN_PEER_LEAVING;
822 break;
823 case PEER_LOST_CONTACT_EVT:
824 state = SELF_LEAVING_PEER_DOWN;
825 break;
826 case NODE_FAILOVER_END_EVT:
827 state = SELF_UP_PEER_UP;
828 break;
829 case NODE_FAILOVER_BEGIN_EVT:
830 case SELF_ESTABL_CONTACT_EVT:
831 case PEER_ESTABL_CONTACT_EVT:
832 break;
833 case NODE_SYNCH_BEGIN_EVT:
834 case NODE_SYNCH_END_EVT:
835 default:
836 goto illegal_evt;
837 }
838 break;
839 case NODE_SYNCHING:
840 switch (evt) {
841 case SELF_LOST_CONTACT_EVT:
842 state = SELF_DOWN_PEER_LEAVING;
843 break;
844 case PEER_LOST_CONTACT_EVT:
845 state = SELF_LEAVING_PEER_DOWN;
846 break;
847 case NODE_SYNCH_END_EVT:
848 state = SELF_UP_PEER_UP;
849 break;
850 case NODE_FAILOVER_BEGIN_EVT:
851 state = NODE_FAILINGOVER;
852 break;
853 case NODE_SYNCH_BEGIN_EVT:
854 case SELF_ESTABL_CONTACT_EVT:
855 case PEER_ESTABL_CONTACT_EVT:
856 break;
857 case NODE_FAILOVER_END_EVT:
858 default:
859 goto illegal_evt;
860 }
861 break;
862 default:
863 pr_err("Unknown node fsm state %x\n", state);
864 break;
865 }
866 n->state = state;
867 return;
868
869 illegal_evt:
870 pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
871 }
872
873 bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
874 {
875 int state = n->state;
876
877 if (likely(state == SELF_UP_PEER_UP))
878 return true;
879
880 if (state == SELF_LEAVING_PEER_DOWN)
881 return false;
882
883 if (state == SELF_DOWN_PEER_LEAVING) {
884 if (msg_peer_node_is_up(hdr))
885 return false;
886 }
887
888 return true;
889 }
890
891 static void node_lost_contact(struct tipc_node *n,
892 struct sk_buff_head *inputq)
893 {
894 char addr_string[16];
895 struct tipc_sock_conn *conn, *safe;
896 struct tipc_link *l;
897 struct list_head *conns = &n->conn_sks;
898 struct sk_buff *skb;
899 uint i;
900
901 pr_debug("Lost contact with %s\n",
902 tipc_addr_string_fill(addr_string, n->addr));
903
904 /* Clean up broadcast state */
905 tipc_bcast_remove_peer(n->net, n->bc_entry.link);
906
907 /* Abort any ongoing link failover */
908 for (i = 0; i < MAX_BEARERS; i++) {
909 l = n->links[i].link;
910 if (l)
911 tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
912 }
913
914 /* Notify publications from this node */
915 n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
916
917 /* Notify sockets connected to node */
918 list_for_each_entry_safe(conn, safe, conns, list) {
919 skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
920 SHORT_H_SIZE, 0, tipc_own_addr(n->net),
921 conn->peer_node, conn->port,
922 conn->peer_port, TIPC_ERR_NO_NODE);
923 if (likely(skb))
924 skb_queue_tail(inputq, skb);
925 list_del(&conn->list);
926 kfree(conn);
927 }
928 }
929
930 /**
931 * tipc_node_get_linkname - get the name of a link
932 *
933 * @bearer_id: id of the bearer
934 * @node: peer node address
935 * @linkname: link name output buffer
936 *
937 * Returns 0 on success
938 */
939 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
940 char *linkname, size_t len)
941 {
942 struct tipc_link *link;
943 int err = -EINVAL;
944 struct tipc_node *node = tipc_node_find(net, addr);
945
946 if (!node)
947 return err;
948
949 if (bearer_id >= MAX_BEARERS)
950 goto exit;
951
952 tipc_node_lock(node);
953 link = node->links[bearer_id].link;
954 if (link) {
955 strncpy(linkname, link->name, len);
956 err = 0;
957 }
958 exit:
959 tipc_node_unlock(node);
960 tipc_node_put(node);
961 return err;
962 }
963
964 void tipc_node_unlock(struct tipc_node *node)
965 {
966 struct net *net = node->net;
967 u32 addr = 0;
968 u32 flags = node->action_flags;
969 u32 link_id = 0;
970 struct list_head *publ_list;
971
972 if (likely(!flags)) {
973 spin_unlock_bh(&node->lock);
974 return;
975 }
976
977 addr = node->addr;
978 link_id = node->link_id;
979 publ_list = &node->publ_list;
980
981 node->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
982 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
983
984 spin_unlock_bh(&node->lock);
985
986 if (flags & TIPC_NOTIFY_NODE_DOWN)
987 tipc_publ_notify(net, publ_list, addr);
988
989 if (flags & TIPC_NOTIFY_NODE_UP)
990 tipc_named_node_up(net, addr);
991
992 if (flags & TIPC_NOTIFY_LINK_UP)
993 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
994 TIPC_NODE_SCOPE, link_id, addr);
995
996 if (flags & TIPC_NOTIFY_LINK_DOWN)
997 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
998 link_id, addr);
999
1000 }
1001
1002 /* Caller should hold node lock for the passed node */
1003 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
1004 {
1005 void *hdr;
1006 struct nlattr *attrs;
1007
1008 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1009 NLM_F_MULTI, TIPC_NL_NODE_GET);
1010 if (!hdr)
1011 return -EMSGSIZE;
1012
1013 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
1014 if (!attrs)
1015 goto msg_full;
1016
1017 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
1018 goto attr_msg_full;
1019 if (tipc_node_is_up(node))
1020 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
1021 goto attr_msg_full;
1022
1023 nla_nest_end(msg->skb, attrs);
1024 genlmsg_end(msg->skb, hdr);
1025
1026 return 0;
1027
1028 attr_msg_full:
1029 nla_nest_cancel(msg->skb, attrs);
1030 msg_full:
1031 genlmsg_cancel(msg->skb, hdr);
1032
1033 return -EMSGSIZE;
1034 }
1035
1036 static struct tipc_link *tipc_node_select_link(struct tipc_node *n, int sel,
1037 int *bearer_id,
1038 struct tipc_media_addr **maddr)
1039 {
1040 int id = n->active_links[sel & 1];
1041
1042 if (unlikely(id < 0))
1043 return NULL;
1044
1045 *bearer_id = id;
1046 *maddr = &n->links[id].maddr;
1047 return n->links[id].link;
1048 }
1049
1050 /**
1051 * tipc_node_xmit() is the general link level function for message sending
1052 * @net: the applicable net namespace
1053 * @list: chain of buffers containing message
1054 * @dnode: address of destination node
1055 * @selector: a number used for deterministic link selection
1056 * Consumes the buffer chain, except when returning -ELINKCONG
1057 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
1058 */
1059 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1060 u32 dnode, int selector)
1061 {
1062 struct tipc_link *l = NULL;
1063 struct tipc_node *n;
1064 struct sk_buff_head xmitq;
1065 struct tipc_media_addr *maddr;
1066 int bearer_id;
1067 int rc = -EHOSTUNREACH;
1068
1069 __skb_queue_head_init(&xmitq);
1070 n = tipc_node_find(net, dnode);
1071 if (likely(n)) {
1072 tipc_node_lock(n);
1073 l = tipc_node_select_link(n, selector, &bearer_id, &maddr);
1074 if (likely(l))
1075 rc = tipc_link_xmit(l, list, &xmitq);
1076 tipc_node_unlock(n);
1077 if (unlikely(rc == -ENOBUFS))
1078 tipc_node_link_down(n, bearer_id, false);
1079 tipc_node_put(n);
1080 }
1081 if (likely(!rc)) {
1082 tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
1083 return 0;
1084 }
1085 if (likely(in_own_node(net, dnode))) {
1086 tipc_sk_rcv(net, list);
1087 return 0;
1088 }
1089 return rc;
1090 }
1091
1092 /* tipc_node_xmit_skb(): send single buffer to destination
1093 * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1094 * messages, which will not be rejected
1095 * The only exception is datagram messages rerouted after secondary
1096 * lookup, which are rare and safe to dispose of anyway.
1097 * TODO: Return real return value, and let callers use
1098 * tipc_wait_for_sendpkt() where applicable
1099 */
1100 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1101 u32 selector)
1102 {
1103 struct sk_buff_head head;
1104 int rc;
1105
1106 skb_queue_head_init(&head);
1107 __skb_queue_tail(&head, skb);
1108 rc = tipc_node_xmit(net, &head, dnode, selector);
1109 if (rc == -ELINKCONG)
1110 kfree_skb(skb);
1111 return 0;
1112 }
1113
1114 void tipc_node_broadcast(struct net *net, struct sk_buff *skb)
1115 {
1116 struct sk_buff *txskb;
1117 struct tipc_node *n;
1118 u32 dst;
1119
1120 rcu_read_lock();
1121 list_for_each_entry_rcu(n, tipc_nodes(net), list) {
1122 dst = n->addr;
1123 if (in_own_node(net, dst))
1124 continue;
1125 if (!tipc_node_is_up(n))
1126 continue;
1127 txskb = pskb_copy(skb, GFP_ATOMIC);
1128 if (!txskb)
1129 break;
1130 msg_set_destnode(buf_msg(txskb), dst);
1131 tipc_node_xmit_skb(net, txskb, dst, 0);
1132 }
1133 rcu_read_unlock();
1134
1135 kfree_skb(skb);
1136 }
1137
1138 /**
1139 * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1140 * @net: the applicable net namespace
1141 * @skb: TIPC packet
1142 * @bearer_id: id of bearer message arrived on
1143 *
1144 * Invoked with no locks held.
1145 */
1146 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1147 {
1148 int rc;
1149 struct sk_buff_head xmitq;
1150 struct tipc_bclink_entry *be;
1151 struct tipc_link_entry *le;
1152 struct tipc_msg *hdr = buf_msg(skb);
1153 int usr = msg_user(hdr);
1154 u32 dnode = msg_destnode(hdr);
1155 struct tipc_node *n;
1156
1157 __skb_queue_head_init(&xmitq);
1158
1159 /* If NACK for other node, let rcv link for that node peek into it */
1160 if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1161 n = tipc_node_find(net, dnode);
1162 else
1163 n = tipc_node_find(net, msg_prevnode(hdr));
1164 if (!n) {
1165 kfree_skb(skb);
1166 return;
1167 }
1168 be = &n->bc_entry;
1169 le = &n->links[bearer_id];
1170
1171 rc = tipc_bcast_rcv(net, be->link, skb);
1172
1173 /* Broadcast link reset may happen at reassembly failure */
1174 if (rc & TIPC_LINK_DOWN_EVT)
1175 tipc_node_reset_links(n);
1176
1177 /* Broadcast ACKs are sent on a unicast link */
1178 if (rc & TIPC_LINK_SND_BC_ACK) {
1179 tipc_node_lock(n);
1180 tipc_link_build_ack_msg(le->link, &xmitq);
1181 tipc_node_unlock(n);
1182 }
1183
1184 if (!skb_queue_empty(&xmitq))
1185 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1186
1187 /* Deliver. 'arrvq' is under inputq2's lock protection */
1188 if (!skb_queue_empty(&be->inputq1)) {
1189 spin_lock_bh(&be->inputq2.lock);
1190 spin_lock_bh(&be->inputq1.lock);
1191 skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1192 spin_unlock_bh(&be->inputq1.lock);
1193 spin_unlock_bh(&be->inputq2.lock);
1194 tipc_sk_mcast_rcv(net, &be->arrvq, &be->inputq2);
1195 }
1196 tipc_node_put(n);
1197 }
1198
1199 /**
1200 * tipc_node_check_state - check and if necessary update node state
1201 * @skb: TIPC packet
1202 * @bearer_id: identity of bearer delivering the packet
1203 * Returns true if state is ok, otherwise consumes buffer and returns false
1204 */
1205 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1206 int bearer_id, struct sk_buff_head *xmitq)
1207 {
1208 struct tipc_msg *hdr = buf_msg(skb);
1209 int usr = msg_user(hdr);
1210 int mtyp = msg_type(hdr);
1211 u16 oseqno = msg_seqno(hdr);
1212 u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1213 u16 exp_pkts = msg_msgcnt(hdr);
1214 u16 rcv_nxt, syncpt, dlv_nxt;
1215 int state = n->state;
1216 struct tipc_link *l, *tnl, *pl = NULL;
1217 struct tipc_media_addr *maddr;
1218 int i, pb_id;
1219
1220 l = n->links[bearer_id].link;
1221 if (!l)
1222 return false;
1223 rcv_nxt = l->rcv_nxt;
1224
1225
1226 if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1227 return true;
1228
1229 /* Find parallel link, if any */
1230 for (i = 0; i < MAX_BEARERS; i++) {
1231 if ((i != bearer_id) && n->links[i].link) {
1232 pl = n->links[i].link;
1233 break;
1234 }
1235 }
1236
1237 /* Update node accesibility if applicable */
1238 if (state == SELF_UP_PEER_COMING) {
1239 if (!tipc_link_is_up(l))
1240 return true;
1241 if (!msg_peer_link_is_up(hdr))
1242 return true;
1243 tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1244 }
1245
1246 if (state == SELF_DOWN_PEER_LEAVING) {
1247 if (msg_peer_node_is_up(hdr))
1248 return false;
1249 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1250 return true;
1251 }
1252
1253 /* Ignore duplicate packets */
1254 if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1255 return true;
1256
1257 /* Initiate or update failover mode if applicable */
1258 if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1259 syncpt = oseqno + exp_pkts - 1;
1260 if (pl && tipc_link_is_up(pl)) {
1261 pb_id = pl->bearer_id;
1262 __tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1263 tipc_skb_queue_splice_tail_init(pl->inputq, l->inputq);
1264 }
1265 /* If pkts arrive out of order, use lowest calculated syncpt */
1266 if (less(syncpt, n->sync_point))
1267 n->sync_point = syncpt;
1268 }
1269
1270 /* Open parallel link when tunnel link reaches synch point */
1271 if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1272 if (!more(rcv_nxt, n->sync_point))
1273 return true;
1274 tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1275 if (pl)
1276 tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1277 return true;
1278 }
1279
1280 /* No synching needed if only one link */
1281 if (!pl || !tipc_link_is_up(pl))
1282 return true;
1283
1284 /* Initiate synch mode if applicable */
1285 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1286 syncpt = iseqno + exp_pkts - 1;
1287 if (!tipc_link_is_up(l)) {
1288 tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
1289 __tipc_node_link_up(n, bearer_id, xmitq);
1290 }
1291 if (n->state == SELF_UP_PEER_UP) {
1292 n->sync_point = syncpt;
1293 tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1294 tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1295 }
1296 }
1297
1298 /* Open tunnel link when parallel link reaches synch point */
1299 if (n->state == NODE_SYNCHING) {
1300 if (tipc_link_is_synching(l)) {
1301 tnl = l;
1302 } else {
1303 tnl = pl;
1304 pl = l;
1305 }
1306 dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
1307 if (more(dlv_nxt, n->sync_point)) {
1308 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1309 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1310 return true;
1311 }
1312 if (l == pl)
1313 return true;
1314 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1315 return true;
1316 if (usr == LINK_PROTOCOL)
1317 return true;
1318 return false;
1319 }
1320 return true;
1321 }
1322
1323 /**
1324 * tipc_rcv - process TIPC packets/messages arriving from off-node
1325 * @net: the applicable net namespace
1326 * @skb: TIPC packet
1327 * @bearer: pointer to bearer message arrived on
1328 *
1329 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1330 * structure (i.e. cannot be NULL), but bearer can be inactive.
1331 */
1332 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1333 {
1334 struct sk_buff_head xmitq;
1335 struct tipc_node *n;
1336 struct tipc_msg *hdr = buf_msg(skb);
1337 int usr = msg_user(hdr);
1338 int bearer_id = b->identity;
1339 struct tipc_link_entry *le;
1340 u16 bc_ack = msg_bcast_ack(hdr);
1341 int rc = 0;
1342
1343 __skb_queue_head_init(&xmitq);
1344
1345 /* Ensure message is well-formed */
1346 if (unlikely(!tipc_msg_validate(skb)))
1347 goto discard;
1348
1349 /* Handle arrival of discovery or broadcast packet */
1350 if (unlikely(msg_non_seq(hdr))) {
1351 if (unlikely(usr == LINK_CONFIG))
1352 return tipc_disc_rcv(net, skb, b);
1353 else
1354 return tipc_node_bc_rcv(net, skb, bearer_id);
1355 }
1356
1357 /* Locate neighboring node that sent packet */
1358 n = tipc_node_find(net, msg_prevnode(hdr));
1359 if (unlikely(!n))
1360 goto discard;
1361 le = &n->links[bearer_id];
1362
1363 /* Ensure broadcast reception is in synch with peer's send state */
1364 if (unlikely(usr == LINK_PROTOCOL))
1365 tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr);
1366 else if (unlikely(n->bc_entry.link->acked != bc_ack))
1367 tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
1368
1369 tipc_node_lock(n);
1370
1371 /* Is reception permitted at the moment ? */
1372 if (!tipc_node_filter_pkt(n, hdr))
1373 goto unlock;
1374
1375 /* Check and if necessary update node state */
1376 if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
1377 rc = tipc_link_rcv(le->link, skb, &xmitq);
1378 skb = NULL;
1379 }
1380 unlock:
1381 tipc_node_unlock(n);
1382
1383 if (unlikely(rc & TIPC_LINK_UP_EVT))
1384 tipc_node_link_up(n, bearer_id, &xmitq);
1385
1386 if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1387 tipc_node_link_down(n, bearer_id, false);
1388
1389 if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1390 tipc_named_rcv(net, &n->bc_entry.namedq);
1391
1392 if (!skb_queue_empty(&le->inputq))
1393 tipc_sk_rcv(net, &le->inputq);
1394
1395 if (!skb_queue_empty(&xmitq))
1396 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1397
1398 tipc_node_put(n);
1399 discard:
1400 kfree_skb(skb);
1401 }
1402
1403 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1404 {
1405 int err;
1406 struct net *net = sock_net(skb->sk);
1407 struct tipc_net *tn = net_generic(net, tipc_net_id);
1408 int done = cb->args[0];
1409 int last_addr = cb->args[1];
1410 struct tipc_node *node;
1411 struct tipc_nl_msg msg;
1412
1413 if (done)
1414 return 0;
1415
1416 msg.skb = skb;
1417 msg.portid = NETLINK_CB(cb->skb).portid;
1418 msg.seq = cb->nlh->nlmsg_seq;
1419
1420 rcu_read_lock();
1421 if (last_addr) {
1422 node = tipc_node_find(net, last_addr);
1423 if (!node) {
1424 rcu_read_unlock();
1425 /* We never set seq or call nl_dump_check_consistent()
1426 * this means that setting prev_seq here will cause the
1427 * consistence check to fail in the netlink callback
1428 * handler. Resulting in the NLMSG_DONE message having
1429 * the NLM_F_DUMP_INTR flag set if the node state
1430 * changed while we released the lock.
1431 */
1432 cb->prev_seq = 1;
1433 return -EPIPE;
1434 }
1435 tipc_node_put(node);
1436 }
1437
1438 list_for_each_entry_rcu(node, &tn->node_list, list) {
1439 if (last_addr) {
1440 if (node->addr == last_addr)
1441 last_addr = 0;
1442 else
1443 continue;
1444 }
1445
1446 tipc_node_lock(node);
1447 err = __tipc_nl_add_node(&msg, node);
1448 if (err) {
1449 last_addr = node->addr;
1450 tipc_node_unlock(node);
1451 goto out;
1452 }
1453
1454 tipc_node_unlock(node);
1455 }
1456 done = 1;
1457 out:
1458 cb->args[0] = done;
1459 cb->args[1] = last_addr;
1460 rcu_read_unlock();
1461
1462 return skb->len;
1463 }
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