projects / deliverable / linux.git / blob
? search:


2670751d0e2e935b0b9b36efc3455f49f6680fd9
[deliverable/linux.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 node_established_contact(struct tipc_node *n_ptr);
76 static void tipc_node_delete(struct tipc_node *node);
77 static void tipc_node_timeout(unsigned long data);
78 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
79
80 struct tipc_sock_conn {
81 u32 port;
82 u32 peer_port;
83 u32 peer_node;
84 struct list_head list;
85 };
86
87 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = {
88 [TIPC_NLA_NODE_UNSPEC] = { .type = NLA_UNSPEC },
89 [TIPC_NLA_NODE_ADDR] = { .type = NLA_U32 },
90 [TIPC_NLA_NODE_UP] = { .type = NLA_FLAG }
91 };
92
93 /*
94 * A trivial power-of-two bitmask technique is used for speed, since this
95 * operation is done for every incoming TIPC packet. The number of hash table
96 * entries has been chosen so that no hash chain exceeds 8 nodes and will
97 * usually be much smaller (typically only a single node).
98 */
99 static unsigned int tipc_hashfn(u32 addr)
100 {
101 return addr & (NODE_HTABLE_SIZE - 1);
102 }
103
104 static void tipc_node_kref_release(struct kref *kref)
105 {
106 struct tipc_node *node = container_of(kref, struct tipc_node, kref);
107
108 tipc_node_delete(node);
109 }
110
111 void tipc_node_put(struct tipc_node *node)
112 {
113 kref_put(&node->kref, tipc_node_kref_release);
114 }
115
116 static void tipc_node_get(struct tipc_node *node)
117 {
118 kref_get(&node->kref);
119 }
120
121 /*
122 * tipc_node_find - locate specified node object, if it exists
123 */
124 struct tipc_node *tipc_node_find(struct net *net, u32 addr)
125 {
126 struct tipc_net *tn = net_generic(net, tipc_net_id);
127 struct tipc_node *node;
128
129 if (unlikely(!in_own_cluster_exact(net, addr)))
130 return NULL;
131
132 rcu_read_lock();
133 hlist_for_each_entry_rcu(node, &tn->node_htable[tipc_hashfn(addr)],
134 hash) {
135 if (node->addr == addr) {
136 tipc_node_get(node);
137 rcu_read_unlock();
138 return node;
139 }
140 }
141 rcu_read_unlock();
142 return NULL;
143 }
144
145 struct tipc_node *tipc_node_create(struct net *net, u32 addr, u16 capabilities)
146 {
147 struct tipc_net *tn = net_generic(net, tipc_net_id);
148 struct tipc_node *n_ptr, *temp_node;
149
150 spin_lock_bh(&tn->node_list_lock);
151 n_ptr = tipc_node_find(net, addr);
152 if (n_ptr)
153 goto exit;
154 n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
155 if (!n_ptr) {
156 pr_warn("Node creation failed, no memory\n");
157 goto exit;
158 }
159 n_ptr->addr = addr;
160 n_ptr->net = net;
161 n_ptr->capabilities = capabilities;
162 kref_init(&n_ptr->kref);
163 spin_lock_init(&n_ptr->lock);
164 INIT_HLIST_NODE(&n_ptr->hash);
165 INIT_LIST_HEAD(&n_ptr->list);
166 INIT_LIST_HEAD(&n_ptr->publ_list);
167 INIT_LIST_HEAD(&n_ptr->conn_sks);
168 skb_queue_head_init(&n_ptr->bclink.namedq);
169 __skb_queue_head_init(&n_ptr->bclink.deferdq);
170 hlist_add_head_rcu(&n_ptr->hash, &tn->node_htable[tipc_hashfn(addr)]);
171 list_for_each_entry_rcu(temp_node, &tn->node_list, list) {
172 if (n_ptr->addr < temp_node->addr)
173 break;
174 }
175 list_add_tail_rcu(&n_ptr->list, &temp_node->list);
176 n_ptr->state = SELF_DOWN_PEER_LEAVING;
177 n_ptr->signature = INVALID_NODE_SIG;
178 n_ptr->active_links[0] = INVALID_BEARER_ID;
179 n_ptr->active_links[1] = INVALID_BEARER_ID;
180 tipc_node_get(n_ptr);
181 setup_timer(&n_ptr->timer, tipc_node_timeout, (unsigned long)n_ptr);
182 n_ptr->keepalive_intv = U32_MAX;
183 exit:
184 spin_unlock_bh(&tn->node_list_lock);
185 return n_ptr;
186 }
187
188 static void tipc_node_calculate_timer(struct tipc_node *n, struct tipc_link *l)
189 {
190 unsigned long tol = l->tolerance;
191 unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
192 unsigned long keepalive_intv = msecs_to_jiffies(intv);
193
194 /* Link with lowest tolerance determines timer interval */
195 if (keepalive_intv < n->keepalive_intv)
196 n->keepalive_intv = keepalive_intv;
197
198 /* Ensure link's abort limit corresponds to current interval */
199 l->abort_limit = l->tolerance / jiffies_to_msecs(n->keepalive_intv);
200 }
201
202 static void tipc_node_delete(struct tipc_node *node)
203 {
204 list_del_rcu(&node->list);
205 hlist_del_rcu(&node->hash);
206 kfree_rcu(node, rcu);
207 }
208
209 void tipc_node_stop(struct net *net)
210 {
211 struct tipc_net *tn = net_generic(net, tipc_net_id);
212 struct tipc_node *node, *t_node;
213
214 spin_lock_bh(&tn->node_list_lock);
215 list_for_each_entry_safe(node, t_node, &tn->node_list, list) {
216 if (del_timer(&node->timer))
217 tipc_node_put(node);
218 tipc_node_put(node);
219 }
220 spin_unlock_bh(&tn->node_list_lock);
221 }
222
223 int tipc_node_add_conn(struct net *net, u32 dnode, u32 port, u32 peer_port)
224 {
225 struct tipc_node *node;
226 struct tipc_sock_conn *conn;
227 int err = 0;
228
229 if (in_own_node(net, dnode))
230 return 0;
231
232 node = tipc_node_find(net, dnode);
233 if (!node) {
234 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
235 return -EHOSTUNREACH;
236 }
237 conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
238 if (!conn) {
239 err = -EHOSTUNREACH;
240 goto exit;
241 }
242 conn->peer_node = dnode;
243 conn->port = port;
244 conn->peer_port = peer_port;
245
246 tipc_node_lock(node);
247 list_add_tail(&conn->list, &node->conn_sks);
248 tipc_node_unlock(node);
249 exit:
250 tipc_node_put(node);
251 return err;
252 }
253
254 void tipc_node_remove_conn(struct net *net, u32 dnode, u32 port)
255 {
256 struct tipc_node *node;
257 struct tipc_sock_conn *conn, *safe;
258
259 if (in_own_node(net, dnode))
260 return;
261
262 node = tipc_node_find(net, dnode);
263 if (!node)
264 return;
265
266 tipc_node_lock(node);
267 list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
268 if (port != conn->port)
269 continue;
270 list_del(&conn->list);
271 kfree(conn);
272 }
273 tipc_node_unlock(node);
274 tipc_node_put(node);
275 }
276
277 /* tipc_node_timeout - handle expiration of node timer
278 */
279 static void tipc_node_timeout(unsigned long data)
280 {
281 struct tipc_node *n = (struct tipc_node *)data;
282 struct tipc_link_entry *le;
283 struct sk_buff_head xmitq;
284 int bearer_id;
285 int rc = 0;
286
287 __skb_queue_head_init(&xmitq);
288
289 for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
290 tipc_node_lock(n);
291 le = &n->links[bearer_id];
292 if (le->link) {
293 /* Link tolerance may change asynchronously: */
294 tipc_node_calculate_timer(n, le->link);
295 rc = tipc_link_timeout(le->link, &xmitq);
296 }
297 tipc_node_unlock(n);
298 tipc_bearer_xmit(n->net, bearer_id, &xmitq, &le->maddr);
299 if (rc & TIPC_LINK_DOWN_EVT)
300 tipc_node_link_down(n, bearer_id, false);
301 }
302 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
303 tipc_node_get(n);
304 tipc_node_put(n);
305 }
306
307 /**
308 * __tipc_node_link_up - handle addition of link
309 * Node lock must be held by caller
310 * Link becomes active (alone or shared) or standby, depending on its priority.
311 */
312 static void __tipc_node_link_up(struct tipc_node *n, int bearer_id,
313 struct sk_buff_head *xmitq)
314 {
315 int *slot0 = &n->active_links[0];
316 int *slot1 = &n->active_links[1];
317 struct tipc_link *ol = node_active_link(n, 0);
318 struct tipc_link *nl = n->links[bearer_id].link;
319
320 if (!nl)
321 return;
322
323 tipc_link_fsm_evt(nl, LINK_ESTABLISH_EVT);
324 if (!tipc_link_is_up(nl))
325 return;
326
327 n->working_links++;
328 n->action_flags |= TIPC_NOTIFY_LINK_UP;
329 n->link_id = nl->peer_bearer_id << 16 | bearer_id;
330
331 /* Leave room for tunnel header when returning 'mtu' to users: */
332 n->links[bearer_id].mtu = nl->mtu - INT_H_SIZE;
333
334 tipc_bearer_add_dest(n->net, bearer_id, n->addr);
335
336 pr_debug("Established link <%s> on network plane %c\n",
337 nl->name, nl->net_plane);
338
339 /* First link? => give it both slots */
340 if (!ol) {
341 *slot0 = bearer_id;
342 *slot1 = bearer_id;
343 tipc_link_build_bcast_sync_msg(nl, xmitq);
344 node_established_contact(n);
345 return;
346 }
347
348 /* Second link => redistribute slots */
349 if (nl->priority > ol->priority) {
350 pr_debug("Old link <%s> becomes standby\n", ol->name);
351 *slot0 = bearer_id;
352 *slot1 = bearer_id;
353 } else if (nl->priority == ol->priority) {
354 *slot0 = bearer_id;
355 } else {
356 pr_debug("New link <%s> is standby\n", nl->name);
357 }
358
359 /* Prepare synchronization with first link */
360 tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
361 }
362
363 /**
364 * tipc_node_link_up - handle addition of link
365 *
366 * Link becomes active (alone or shared) or standby, depending on its priority.
367 */
368 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
369 struct sk_buff_head *xmitq)
370 {
371 tipc_node_lock(n);
372 __tipc_node_link_up(n, bearer_id, xmitq);
373 tipc_node_unlock(n);
374 }
375
376 /**
377 * __tipc_node_link_down - handle loss of link
378 */
379 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
380 struct sk_buff_head *xmitq,
381 struct tipc_media_addr **maddr)
382 {
383 struct tipc_link_entry *le = &n->links[*bearer_id];
384 int *slot0 = &n->active_links[0];
385 int *slot1 = &n->active_links[1];
386 int i, highest = 0;
387 struct tipc_link *l, *_l, *tnl;
388
389 l = n->links[*bearer_id].link;
390 if (!l || tipc_link_is_reset(l))
391 return;
392
393 n->working_links--;
394 n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
395 n->link_id = l->peer_bearer_id << 16 | *bearer_id;
396
397 tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
398
399 pr_debug("Lost link <%s> on network plane %c\n",
400 l->name, l->net_plane);
401
402 /* Select new active link if any available */
403 *slot0 = INVALID_BEARER_ID;
404 *slot1 = INVALID_BEARER_ID;
405 for (i = 0; i < MAX_BEARERS; i++) {
406 _l = n->links[i].link;
407 if (!_l || !tipc_link_is_up(_l))
408 continue;
409 if (_l == l)
410 continue;
411 if (_l->priority < highest)
412 continue;
413 if (_l->priority > highest) {
414 highest = _l->priority;
415 *slot0 = i;
416 *slot1 = i;
417 continue;
418 }
419 *slot1 = i;
420 }
421
422 if (!tipc_node_is_up(n)) {
423 if (tipc_link_peer_is_down(l))
424 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
425 tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
426 tipc_link_fsm_evt(l, LINK_RESET_EVT);
427 tipc_link_reset(l);
428 tipc_link_build_reset_msg(l, xmitq);
429 *maddr = &n->links[*bearer_id].maddr;
430 node_lost_contact(n, &le->inputq);
431 return;
432 }
433
434 /* There is still a working link => initiate failover */
435 tnl = node_active_link(n, 0);
436 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
437 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
438 n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
439 tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
440 tipc_link_reset(l);
441 tipc_link_fsm_evt(l, LINK_RESET_EVT);
442 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
443 tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
444 *maddr = &n->links[tnl->bearer_id].maddr;
445 *bearer_id = tnl->bearer_id;
446 }
447
448 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
449 {
450 struct tipc_link_entry *le = &n->links[bearer_id];
451 struct tipc_link *l = le->link;
452 struct tipc_media_addr *maddr;
453 struct sk_buff_head xmitq;
454
455 if (!l)
456 return;
457
458 __skb_queue_head_init(&xmitq);
459
460 tipc_node_lock(n);
461 if (!tipc_link_is_establishing(l)) {
462 __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
463 if (delete) {
464 kfree(l);
465 le->link = NULL;
466 n->link_cnt--;
467 }
468 } else {
469 /* Defuse pending tipc_node_link_up() */
470 tipc_link_fsm_evt(l, LINK_RESET_EVT);
471 }
472 tipc_node_unlock(n);
473 tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
474 tipc_sk_rcv(n->net, &le->inputq);
475 }
476
477 bool tipc_node_is_up(struct tipc_node *n)
478 {
479 return n->active_links[0] != INVALID_BEARER_ID;
480 }
481
482 void tipc_node_check_dest(struct net *net, u32 onode,
483 struct tipc_bearer *b,
484 u16 capabilities, u32 signature,
485 struct tipc_media_addr *maddr,
486 bool *respond, bool *dupl_addr)
487 {
488 struct tipc_node *n;
489 struct tipc_link *l;
490 struct tipc_link_entry *le;
491 bool addr_match = false;
492 bool sign_match = false;
493 bool link_up = false;
494 bool accept_addr = false;
495 bool reset = true;
496
497 *dupl_addr = false;
498 *respond = false;
499
500 n = tipc_node_create(net, onode, capabilities);
501 if (!n)
502 return;
503
504 tipc_node_lock(n);
505
506 le = &n->links[b->identity];
507
508 /* Prepare to validate requesting node's signature and media address */
509 l = le->link;
510 link_up = l && tipc_link_is_up(l);
511 addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
512 sign_match = (signature == n->signature);
513
514 /* These three flags give us eight permutations: */
515
516 if (sign_match && addr_match && link_up) {
517 /* All is fine. Do nothing. */
518 reset = false;
519 } else if (sign_match && addr_match && !link_up) {
520 /* Respond. The link will come up in due time */
521 *respond = true;
522 } else if (sign_match && !addr_match && link_up) {
523 /* Peer has changed i/f address without rebooting.
524 * If so, the link will reset soon, and the next
525 * discovery will be accepted. So we can ignore it.
526 * It may also be an cloned or malicious peer having
527 * chosen the same node address and signature as an
528 * existing one.
529 * Ignore requests until the link goes down, if ever.
530 */
531 *dupl_addr = true;
532 } else if (sign_match && !addr_match && !link_up) {
533 /* Peer link has changed i/f address without rebooting.
534 * It may also be a cloned or malicious peer; we can't
535 * distinguish between the two.
536 * The signature is correct, so we must accept.
537 */
538 accept_addr = true;
539 *respond = true;
540 } else if (!sign_match && addr_match && link_up) {
541 /* Peer node rebooted. Two possibilities:
542 * - Delayed re-discovery; this link endpoint has already
543 * reset and re-established contact with the peer, before
544 * receiving a discovery message from that node.
545 * (The peer happened to receive one from this node first).
546 * - The peer came back so fast that our side has not
547 * discovered it yet. Probing from this side will soon
548 * reset the link, since there can be no working link
549 * endpoint at the peer end, and the link will re-establish.
550 * Accept the signature, since it comes from a known peer.
551 */
552 n->signature = signature;
553 } else if (!sign_match && addr_match && !link_up) {
554 /* The peer node has rebooted.
555 * Accept signature, since it is a known peer.
556 */
557 n->signature = signature;
558 *respond = true;
559 } else if (!sign_match && !addr_match && link_up) {
560 /* Peer rebooted with new address, or a new/duplicate peer.
561 * Ignore until the link goes down, if ever.
562 */
563 *dupl_addr = true;
564 } else if (!sign_match && !addr_match && !link_up) {
565 /* Peer rebooted with new address, or it is a new peer.
566 * Accept signature and address.
567 */
568 n->signature = signature;
569 accept_addr = true;
570 *respond = true;
571 }
572
573 if (!accept_addr)
574 goto exit;
575
576 /* Now create new link if not already existing */
577 if (!l) {
578 if (n->link_cnt == 2) {
579 pr_warn("Cannot establish 3rd link to %x\n", n->addr);
580 goto exit;
581 }
582 if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
583 tipc_own_addr(net), onode, &le->maddr,
584 &le->inputq, &n->bclink.namedq, &l)) {
585 *respond = false;
586 goto exit;
587 }
588 tipc_link_reset(l);
589 tipc_link_fsm_evt(l, LINK_RESET_EVT);
590 if (n->state == NODE_FAILINGOVER)
591 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
592 le->link = l;
593 n->link_cnt++;
594 tipc_node_calculate_timer(n, l);
595 if (n->link_cnt == 1)
596 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
597 tipc_node_get(n);
598 }
599 memcpy(&le->maddr, maddr, sizeof(*maddr));
600 exit:
601 tipc_node_unlock(n);
602 if (reset && !tipc_link_is_reset(l))
603 tipc_node_link_down(n, b->identity, false);
604 tipc_node_put(n);
605 }
606
607 void tipc_node_delete_links(struct net *net, int bearer_id)
608 {
609 struct tipc_net *tn = net_generic(net, tipc_net_id);
610 struct tipc_node *n;
611
612 rcu_read_lock();
613 list_for_each_entry_rcu(n, &tn->node_list, list) {
614 tipc_node_link_down(n, bearer_id, true);
615 }
616 rcu_read_unlock();
617 }
618
619 static void tipc_node_reset_links(struct tipc_node *n)
620 {
621 char addr_string[16];
622 int i;
623
624 pr_warn("Resetting all links to %s\n",
625 tipc_addr_string_fill(addr_string, n->addr));
626
627 for (i = 0; i < MAX_BEARERS; i++) {
628 tipc_node_link_down(n, i, false);
629 }
630 }
631
632 /* tipc_node_fsm_evt - node finite state machine
633 * Determines when contact is allowed with peer node
634 */
635 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
636 {
637 int state = n->state;
638
639 switch (state) {
640 case SELF_DOWN_PEER_DOWN:
641 switch (evt) {
642 case SELF_ESTABL_CONTACT_EVT:
643 state = SELF_UP_PEER_COMING;
644 break;
645 case PEER_ESTABL_CONTACT_EVT:
646 state = SELF_COMING_PEER_UP;
647 break;
648 case SELF_LOST_CONTACT_EVT:
649 case PEER_LOST_CONTACT_EVT:
650 break;
651 case NODE_SYNCH_END_EVT:
652 case NODE_SYNCH_BEGIN_EVT:
653 case NODE_FAILOVER_BEGIN_EVT:
654 case NODE_FAILOVER_END_EVT:
655 default:
656 goto illegal_evt;
657 }
658 break;
659 case SELF_UP_PEER_UP:
660 switch (evt) {
661 case SELF_LOST_CONTACT_EVT:
662 state = SELF_DOWN_PEER_LEAVING;
663 break;
664 case PEER_LOST_CONTACT_EVT:
665 state = SELF_LEAVING_PEER_DOWN;
666 break;
667 case NODE_SYNCH_BEGIN_EVT:
668 state = NODE_SYNCHING;
669 break;
670 case NODE_FAILOVER_BEGIN_EVT:
671 state = NODE_FAILINGOVER;
672 break;
673 case SELF_ESTABL_CONTACT_EVT:
674 case PEER_ESTABL_CONTACT_EVT:
675 case NODE_SYNCH_END_EVT:
676 case NODE_FAILOVER_END_EVT:
677 break;
678 default:
679 goto illegal_evt;
680 }
681 break;
682 case SELF_DOWN_PEER_LEAVING:
683 switch (evt) {
684 case PEER_LOST_CONTACT_EVT:
685 state = SELF_DOWN_PEER_DOWN;
686 break;
687 case SELF_ESTABL_CONTACT_EVT:
688 case PEER_ESTABL_CONTACT_EVT:
689 case SELF_LOST_CONTACT_EVT:
690 break;
691 case NODE_SYNCH_END_EVT:
692 case NODE_SYNCH_BEGIN_EVT:
693 case NODE_FAILOVER_BEGIN_EVT:
694 case NODE_FAILOVER_END_EVT:
695 default:
696 goto illegal_evt;
697 }
698 break;
699 case SELF_UP_PEER_COMING:
700 switch (evt) {
701 case PEER_ESTABL_CONTACT_EVT:
702 state = SELF_UP_PEER_UP;
703 break;
704 case SELF_LOST_CONTACT_EVT:
705 state = SELF_DOWN_PEER_LEAVING;
706 break;
707 case SELF_ESTABL_CONTACT_EVT:
708 case PEER_LOST_CONTACT_EVT:
709 case NODE_SYNCH_END_EVT:
710 case NODE_FAILOVER_BEGIN_EVT:
711 break;
712 case NODE_SYNCH_BEGIN_EVT:
713 case NODE_FAILOVER_END_EVT:
714 default:
715 goto illegal_evt;
716 }
717 break;
718 case SELF_COMING_PEER_UP:
719 switch (evt) {
720 case SELF_ESTABL_CONTACT_EVT:
721 state = SELF_UP_PEER_UP;
722 break;
723 case PEER_LOST_CONTACT_EVT:
724 state = SELF_LEAVING_PEER_DOWN;
725 break;
726 case SELF_LOST_CONTACT_EVT:
727 case PEER_ESTABL_CONTACT_EVT:
728 break;
729 case NODE_SYNCH_END_EVT:
730 case NODE_SYNCH_BEGIN_EVT:
731 case NODE_FAILOVER_BEGIN_EVT:
732 case NODE_FAILOVER_END_EVT:
733 default:
734 goto illegal_evt;
735 }
736 break;
737 case SELF_LEAVING_PEER_DOWN:
738 switch (evt) {
739 case SELF_LOST_CONTACT_EVT:
740 state = SELF_DOWN_PEER_DOWN;
741 break;
742 case SELF_ESTABL_CONTACT_EVT:
743 case PEER_ESTABL_CONTACT_EVT:
744 case PEER_LOST_CONTACT_EVT:
745 break;
746 case NODE_SYNCH_END_EVT:
747 case NODE_SYNCH_BEGIN_EVT:
748 case NODE_FAILOVER_BEGIN_EVT:
749 case NODE_FAILOVER_END_EVT:
750 default:
751 goto illegal_evt;
752 }
753 break;
754 case NODE_FAILINGOVER:
755 switch (evt) {
756 case SELF_LOST_CONTACT_EVT:
757 state = SELF_DOWN_PEER_LEAVING;
758 break;
759 case PEER_LOST_CONTACT_EVT:
760 state = SELF_LEAVING_PEER_DOWN;
761 break;
762 case NODE_FAILOVER_END_EVT:
763 state = SELF_UP_PEER_UP;
764 break;
765 case NODE_FAILOVER_BEGIN_EVT:
766 case SELF_ESTABL_CONTACT_EVT:
767 case PEER_ESTABL_CONTACT_EVT:
768 break;
769 case NODE_SYNCH_BEGIN_EVT:
770 case NODE_SYNCH_END_EVT:
771 default:
772 goto illegal_evt;
773 }
774 break;
775 case NODE_SYNCHING:
776 switch (evt) {
777 case SELF_LOST_CONTACT_EVT:
778 state = SELF_DOWN_PEER_LEAVING;
779 break;
780 case PEER_LOST_CONTACT_EVT:
781 state = SELF_LEAVING_PEER_DOWN;
782 break;
783 case NODE_SYNCH_END_EVT:
784 state = SELF_UP_PEER_UP;
785 break;
786 case NODE_FAILOVER_BEGIN_EVT:
787 state = NODE_FAILINGOVER;
788 break;
789 case NODE_SYNCH_BEGIN_EVT:
790 case SELF_ESTABL_CONTACT_EVT:
791 case PEER_ESTABL_CONTACT_EVT:
792 break;
793 case NODE_FAILOVER_END_EVT:
794 default:
795 goto illegal_evt;
796 }
797 break;
798 default:
799 pr_err("Unknown node fsm state %x\n", state);
800 break;
801 }
802 n->state = state;
803 return;
804
805 illegal_evt:
806 pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
807 }
808
809 bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
810 {
811 int state = n->state;
812
813 if (likely(state == SELF_UP_PEER_UP))
814 return true;
815
816 if (state == SELF_LEAVING_PEER_DOWN)
817 return false;
818
819 if (state == SELF_DOWN_PEER_LEAVING) {
820 if (msg_peer_node_is_up(hdr))
821 return false;
822 }
823
824 return true;
825 }
826
827 static void node_established_contact(struct tipc_node *n_ptr)
828 {
829 tipc_node_fsm_evt(n_ptr, SELF_ESTABL_CONTACT_EVT);
830 n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
831 n_ptr->bclink.oos_state = 0;
832 n_ptr->bclink.acked = tipc_bclink_get_last_sent(n_ptr->net);
833 tipc_bclink_add_node(n_ptr->net, n_ptr->addr);
834 }
835
836 static void node_lost_contact(struct tipc_node *n_ptr,
837 struct sk_buff_head *inputq)
838 {
839 char addr_string[16];
840 struct tipc_sock_conn *conn, *safe;
841 struct tipc_link *l;
842 struct list_head *conns = &n_ptr->conn_sks;
843 struct sk_buff *skb;
844 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
845 uint i;
846
847 pr_debug("Lost contact with %s\n",
848 tipc_addr_string_fill(addr_string, n_ptr->addr));
849
850 /* Flush broadcast link info associated with lost node */
851 if (n_ptr->bclink.recv_permitted) {
852 __skb_queue_purge(&n_ptr->bclink.deferdq);
853
854 if (n_ptr->bclink.reasm_buf) {
855 kfree_skb(n_ptr->bclink.reasm_buf);
856 n_ptr->bclink.reasm_buf = NULL;
857 }
858
859 tipc_bclink_remove_node(n_ptr->net, n_ptr->addr);
860 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
861
862 n_ptr->bclink.recv_permitted = false;
863 }
864
865 /* Abort any ongoing link failover */
866 for (i = 0; i < MAX_BEARERS; i++) {
867 l = n_ptr->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_ptr->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, tn->own_addr,
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_check_state - check and if necessary update node state
1084 * @skb: TIPC packet
1085 * @bearer_id: identity of bearer delivering the packet
1086 * Returns true if state is ok, otherwise consumes buffer and returns false
1087 */
1088 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1089 int bearer_id, struct sk_buff_head *xmitq)
1090 {
1091 struct tipc_msg *hdr = buf_msg(skb);
1092 int usr = msg_user(hdr);
1093 int mtyp = msg_type(hdr);
1094 u16 oseqno = msg_seqno(hdr);
1095 u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1096 u16 exp_pkts = msg_msgcnt(hdr);
1097 u16 rcv_nxt, syncpt, dlv_nxt;
1098 int state = n->state;
1099 struct tipc_link *l, *tnl, *pl = NULL;
1100 struct tipc_media_addr *maddr;
1101 int i, pb_id;
1102
1103 l = n->links[bearer_id].link;
1104 if (!l)
1105 return false;
1106 rcv_nxt = l->rcv_nxt;
1107
1108
1109 if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1110 return true;
1111
1112 /* Find parallel link, if any */
1113 for (i = 0; i < MAX_BEARERS; i++) {
1114 if ((i != bearer_id) && n->links[i].link) {
1115 pl = n->links[i].link;
1116 break;
1117 }
1118 }
1119
1120 /* Update node accesibility if applicable */
1121 if (state == SELF_UP_PEER_COMING) {
1122 if (!tipc_link_is_up(l))
1123 return true;
1124 if (!msg_peer_link_is_up(hdr))
1125 return true;
1126 tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1127 }
1128
1129 if (state == SELF_DOWN_PEER_LEAVING) {
1130 if (msg_peer_node_is_up(hdr))
1131 return false;
1132 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1133 }
1134
1135 /* Ignore duplicate packets */
1136 if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1137 return true;
1138
1139 /* Initiate or update failover mode if applicable */
1140 if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1141 syncpt = oseqno + exp_pkts - 1;
1142 if (pl && tipc_link_is_up(pl)) {
1143 pb_id = pl->bearer_id;
1144 __tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1145 tipc_skb_queue_splice_tail_init(pl->inputq, l->inputq);
1146 }
1147 /* If pkts arrive out of order, use lowest calculated syncpt */
1148 if (less(syncpt, n->sync_point))
1149 n->sync_point = syncpt;
1150 }
1151
1152 /* Open parallel link when tunnel link reaches synch point */
1153 if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1154 if (!more(rcv_nxt, n->sync_point))
1155 return true;
1156 tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1157 if (pl)
1158 tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1159 return true;
1160 }
1161
1162 /* No synching needed if only one link */
1163 if (!pl || !tipc_link_is_up(pl))
1164 return true;
1165
1166 /* Initiate synch mode if applicable */
1167 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1168 syncpt = iseqno + exp_pkts - 1;
1169 if (!tipc_link_is_up(l)) {
1170 tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
1171 __tipc_node_link_up(n, bearer_id, xmitq);
1172 }
1173 if (n->state == SELF_UP_PEER_UP) {
1174 n->sync_point = syncpt;
1175 tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1176 tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1177 }
1178 if (less(syncpt, n->sync_point))
1179 n->sync_point = syncpt;
1180 }
1181
1182 /* Open tunnel link when parallel link reaches synch point */
1183 if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
1184 if (tipc_link_is_synching(l)) {
1185 tnl = l;
1186 } else {
1187 tnl = pl;
1188 pl = l;
1189 }
1190 dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
1191 if (more(dlv_nxt, n->sync_point)) {
1192 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1193 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1194 return true;
1195 }
1196 if (l == pl)
1197 return true;
1198 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1199 return true;
1200 if (usr == LINK_PROTOCOL)
1201 return true;
1202 return false;
1203 }
1204 return true;
1205 }
1206
1207 /**
1208 * tipc_rcv - process TIPC packets/messages arriving from off-node
1209 * @net: the applicable net namespace
1210 * @skb: TIPC packet
1211 * @bearer: pointer to bearer message arrived on
1212 *
1213 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1214 * structure (i.e. cannot be NULL), but bearer can be inactive.
1215 */
1216 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1217 {
1218 struct sk_buff_head xmitq;
1219 struct tipc_node *n;
1220 struct tipc_msg *hdr = buf_msg(skb);
1221 int usr = msg_user(hdr);
1222 int bearer_id = b->identity;
1223 struct tipc_link_entry *le;
1224 int rc = 0;
1225
1226 __skb_queue_head_init(&xmitq);
1227
1228 /* Ensure message is well-formed */
1229 if (unlikely(!tipc_msg_validate(skb)))
1230 goto discard;
1231
1232 /* Handle arrival of a non-unicast link packet */
1233 if (unlikely(msg_non_seq(hdr))) {
1234 if (usr == LINK_CONFIG)
1235 tipc_disc_rcv(net, skb, b);
1236 else
1237 tipc_bclink_rcv(net, skb);
1238 return;
1239 }
1240
1241 /* Locate neighboring node that sent packet */
1242 n = tipc_node_find(net, msg_prevnode(hdr));
1243 if (unlikely(!n))
1244 goto discard;
1245 le = &n->links[bearer_id];
1246
1247 tipc_node_lock(n);
1248
1249 /* Is reception permitted at the moment ? */
1250 if (!tipc_node_filter_pkt(n, hdr))
1251 goto unlock;
1252
1253 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1254 tipc_bclink_sync_state(n, hdr);
1255
1256 /* Release acked broadcast packets */
1257 if (unlikely(n->bclink.acked != msg_bcast_ack(hdr)))
1258 tipc_bclink_acknowledge(n, msg_bcast_ack(hdr));
1259
1260 /* Check and if necessary update node state */
1261 if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
1262 rc = tipc_link_rcv(le->link, skb, &xmitq);
1263 skb = NULL;
1264 }
1265 unlock:
1266 tipc_node_unlock(n);
1267
1268 if (unlikely(rc & TIPC_LINK_UP_EVT))
1269 tipc_node_link_up(n, bearer_id, &xmitq);
1270
1271 if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1272 tipc_node_link_down(n, bearer_id, false);
1273
1274 if (unlikely(!skb_queue_empty(&n->bclink.namedq)))
1275 tipc_named_rcv(net, &n->bclink.namedq);
1276
1277 if (!skb_queue_empty(&le->inputq))
1278 tipc_sk_rcv(net, &le->inputq);
1279
1280 if (!skb_queue_empty(&xmitq))
1281 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1282
1283 tipc_node_put(n);
1284 discard:
1285 kfree_skb(skb);
1286 }
1287
1288 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1289 {
1290 int err;
1291 struct net *net = sock_net(skb->sk);
1292 struct tipc_net *tn = net_generic(net, tipc_net_id);
1293 int done = cb->args[0];
1294 int last_addr = cb->args[1];
1295 struct tipc_node *node;
1296 struct tipc_nl_msg msg;
1297
1298 if (done)
1299 return 0;
1300
1301 msg.skb = skb;
1302 msg.portid = NETLINK_CB(cb->skb).portid;
1303 msg.seq = cb->nlh->nlmsg_seq;
1304
1305 rcu_read_lock();
1306 if (last_addr) {
1307 node = tipc_node_find(net, last_addr);
1308 if (!node) {
1309 rcu_read_unlock();
1310 /* We never set seq or call nl_dump_check_consistent()
1311 * this means that setting prev_seq here will cause the
1312 * consistence check to fail in the netlink callback
1313 * handler. Resulting in the NLMSG_DONE message having
1314 * the NLM_F_DUMP_INTR flag set if the node state
1315 * changed while we released the lock.
1316 */
1317 cb->prev_seq = 1;
1318 return -EPIPE;
1319 }
1320 tipc_node_put(node);
1321 }
1322
1323 list_for_each_entry_rcu(node, &tn->node_list, list) {
1324 if (last_addr) {
1325 if (node->addr == last_addr)
1326 last_addr = 0;
1327 else
1328 continue;
1329 }
1330
1331 tipc_node_lock(node);
1332 err = __tipc_nl_add_node(&msg, node);
1333 if (err) {
1334 last_addr = node->addr;
1335 tipc_node_unlock(node);
1336 goto out;
1337 }
1338
1339 tipc_node_unlock(node);
1340 }
1341 done = 1;
1342 out:
1343 cb->args[0] = done;
1344 cb->args[1] = last_addr;
1345 rcu_read_unlock();
1346
1347 return skb->len;
1348 }
Linux kernel - Deliverables
This page took 0.056137 seconds and 4 git commands to generate.