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