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Merge tag 'for-4.4' of git://git.osdn.jp/gitroot/uclinux-h8/linux
[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 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 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 tipc_bcast_inc_bearer_dst_cnt(n->net, bearer_id);
350
351 pr_debug("Established link <%s> on network plane %c\n",
352 nl->name, nl->net_plane);
353
354 /* First link? => give it both slots */
355 if (!ol) {
356 *slot0 = bearer_id;
357 *slot1 = bearer_id;
358 tipc_node_fsm_evt(n, SELF_ESTABL_CONTACT_EVT);
359 n->action_flags |= TIPC_NOTIFY_NODE_UP;
360 tipc_bcast_add_peer(n->net, nl, xmitq);
361 return;
362 }
363
364 /* Second link => redistribute slots */
365 if (nl->priority > ol->priority) {
366 pr_debug("Old link <%s> becomes standby\n", ol->name);
367 *slot0 = bearer_id;
368 *slot1 = bearer_id;
369 tipc_link_set_active(nl, true);
370 tipc_link_set_active(ol, false);
371 } else if (nl->priority == ol->priority) {
372 tipc_link_set_active(nl, true);
373 *slot1 = bearer_id;
374 } else {
375 pr_debug("New link <%s> is standby\n", nl->name);
376 }
377
378 /* Prepare synchronization with first link */
379 tipc_link_tnl_prepare(ol, nl, SYNCH_MSG, xmitq);
380 }
381
382 /**
383 * tipc_node_link_up - handle addition of link
384 *
385 * Link becomes active (alone or shared) or standby, depending on its priority.
386 */
387 static void tipc_node_link_up(struct tipc_node *n, int bearer_id,
388 struct sk_buff_head *xmitq)
389 {
390 tipc_node_lock(n);
391 __tipc_node_link_up(n, bearer_id, xmitq);
392 tipc_node_unlock(n);
393 }
394
395 /**
396 * __tipc_node_link_down - handle loss of link
397 */
398 static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
399 struct sk_buff_head *xmitq,
400 struct tipc_media_addr **maddr)
401 {
402 struct tipc_link_entry *le = &n->links[*bearer_id];
403 int *slot0 = &n->active_links[0];
404 int *slot1 = &n->active_links[1];
405 int i, highest = 0;
406 struct tipc_link *l, *_l, *tnl;
407
408 l = n->links[*bearer_id].link;
409 if (!l || tipc_link_is_reset(l))
410 return;
411
412 n->working_links--;
413 n->action_flags |= TIPC_NOTIFY_LINK_DOWN;
414 n->link_id = l->peer_bearer_id << 16 | *bearer_id;
415
416 tipc_bearer_remove_dest(n->net, *bearer_id, n->addr);
417
418 pr_debug("Lost link <%s> on network plane %c\n",
419 l->name, l->net_plane);
420
421 /* Select new active link if any available */
422 *slot0 = INVALID_BEARER_ID;
423 *slot1 = INVALID_BEARER_ID;
424 for (i = 0; i < MAX_BEARERS; i++) {
425 _l = n->links[i].link;
426 if (!_l || !tipc_link_is_up(_l))
427 continue;
428 if (_l == l)
429 continue;
430 if (_l->priority < highest)
431 continue;
432 if (_l->priority > highest) {
433 highest = _l->priority;
434 *slot0 = i;
435 *slot1 = i;
436 continue;
437 }
438 *slot1 = i;
439 }
440
441 if (!tipc_node_is_up(n)) {
442 if (tipc_link_peer_is_down(l))
443 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
444 tipc_node_fsm_evt(n, SELF_LOST_CONTACT_EVT);
445 tipc_link_fsm_evt(l, LINK_RESET_EVT);
446 tipc_link_reset(l);
447 tipc_link_build_reset_msg(l, xmitq);
448 *maddr = &n->links[*bearer_id].maddr;
449 node_lost_contact(n, &le->inputq);
450 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
451 return;
452 }
453 tipc_bcast_dec_bearer_dst_cnt(n->net, *bearer_id);
454
455 /* There is still a working link => initiate failover */
456 tnl = node_active_link(n, 0);
457 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
458 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
459 n->sync_point = tnl->rcv_nxt + (U16_MAX / 2 - 1);
460 tipc_link_tnl_prepare(l, tnl, FAILOVER_MSG, xmitq);
461 tipc_link_reset(l);
462 tipc_link_fsm_evt(l, LINK_RESET_EVT);
463 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
464 tipc_node_fsm_evt(n, NODE_FAILOVER_BEGIN_EVT);
465 *maddr = &n->links[tnl->bearer_id].maddr;
466 *bearer_id = tnl->bearer_id;
467 }
468
469 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
470 {
471 struct tipc_link_entry *le = &n->links[bearer_id];
472 struct tipc_link *l = le->link;
473 struct tipc_media_addr *maddr;
474 struct sk_buff_head xmitq;
475
476 if (!l)
477 return;
478
479 __skb_queue_head_init(&xmitq);
480
481 tipc_node_lock(n);
482 if (!tipc_link_is_establishing(l)) {
483 __tipc_node_link_down(n, &bearer_id, &xmitq, &maddr);
484 if (delete) {
485 kfree(l);
486 le->link = NULL;
487 n->link_cnt--;
488 }
489 } else {
490 /* Defuse pending tipc_node_link_up() */
491 tipc_link_fsm_evt(l, LINK_RESET_EVT);
492 }
493 tipc_node_unlock(n);
494 tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
495 tipc_sk_rcv(n->net, &le->inputq);
496 }
497
498 bool tipc_node_is_up(struct tipc_node *n)
499 {
500 return n->active_links[0] != INVALID_BEARER_ID;
501 }
502
503 void tipc_node_check_dest(struct net *net, u32 onode,
504 struct tipc_bearer *b,
505 u16 capabilities, u32 signature,
506 struct tipc_media_addr *maddr,
507 bool *respond, bool *dupl_addr)
508 {
509 struct tipc_node *n;
510 struct tipc_link *l;
511 struct tipc_link_entry *le;
512 bool addr_match = false;
513 bool sign_match = false;
514 bool link_up = false;
515 bool accept_addr = false;
516 bool reset = true;
517 char *if_name;
518
519 *dupl_addr = false;
520 *respond = false;
521
522 n = tipc_node_create(net, onode, capabilities);
523 if (!n)
524 return;
525
526 tipc_node_lock(n);
527
528 le = &n->links[b->identity];
529
530 /* Prepare to validate requesting node's signature and media address */
531 l = le->link;
532 link_up = l && tipc_link_is_up(l);
533 addr_match = l && !memcmp(&le->maddr, maddr, sizeof(*maddr));
534 sign_match = (signature == n->signature);
535
536 /* These three flags give us eight permutations: */
537
538 if (sign_match && addr_match && link_up) {
539 /* All is fine. Do nothing. */
540 reset = false;
541 } else if (sign_match && addr_match && !link_up) {
542 /* Respond. The link will come up in due time */
543 *respond = true;
544 } else if (sign_match && !addr_match && link_up) {
545 /* Peer has changed i/f address without rebooting.
546 * If so, the link will reset soon, and the next
547 * discovery will be accepted. So we can ignore it.
548 * It may also be an cloned or malicious peer having
549 * chosen the same node address and signature as an
550 * existing one.
551 * Ignore requests until the link goes down, if ever.
552 */
553 *dupl_addr = true;
554 } else if (sign_match && !addr_match && !link_up) {
555 /* Peer link has changed i/f address without rebooting.
556 * It may also be a cloned or malicious peer; we can't
557 * distinguish between the two.
558 * The signature is correct, so we must accept.
559 */
560 accept_addr = true;
561 *respond = true;
562 } else if (!sign_match && addr_match && link_up) {
563 /* Peer node rebooted. Two possibilities:
564 * - Delayed re-discovery; this link endpoint has already
565 * reset and re-established contact with the peer, before
566 * receiving a discovery message from that node.
567 * (The peer happened to receive one from this node first).
568 * - The peer came back so fast that our side has not
569 * discovered it yet. Probing from this side will soon
570 * reset the link, since there can be no working link
571 * endpoint at the peer end, and the link will re-establish.
572 * Accept the signature, since it comes from a known peer.
573 */
574 n->signature = signature;
575 } else if (!sign_match && addr_match && !link_up) {
576 /* The peer node has rebooted.
577 * Accept signature, since it is a known peer.
578 */
579 n->signature = signature;
580 *respond = true;
581 } else if (!sign_match && !addr_match && link_up) {
582 /* Peer rebooted with new address, or a new/duplicate peer.
583 * Ignore until the link goes down, if ever.
584 */
585 *dupl_addr = true;
586 } else if (!sign_match && !addr_match && !link_up) {
587 /* Peer rebooted with new address, or it is a new peer.
588 * Accept signature and address.
589 */
590 n->signature = signature;
591 accept_addr = true;
592 *respond = true;
593 }
594
595 if (!accept_addr)
596 goto exit;
597
598 /* Now create new link if not already existing */
599 if (!l) {
600 if (n->link_cnt == 2) {
601 pr_warn("Cannot establish 3rd link to %x\n", n->addr);
602 goto exit;
603 }
604 if_name = strchr(b->name, ':') + 1;
605 if (!tipc_link_create(net, if_name, b->identity, b->tolerance,
606 b->net_plane, b->mtu, b->priority,
607 b->window, mod(tipc_net(net)->random),
608 tipc_own_addr(net), onode,
609 n->capabilities,
610 tipc_bc_sndlink(n->net), n->bc_entry.link,
611 &le->inputq,
612 &n->bc_entry.namedq, &l)) {
613 *respond = false;
614 goto exit;
615 }
616 tipc_link_reset(l);
617 tipc_link_fsm_evt(l, LINK_RESET_EVT);
618 if (n->state == NODE_FAILINGOVER)
619 tipc_link_fsm_evt(l, LINK_FAILOVER_BEGIN_EVT);
620 le->link = l;
621 n->link_cnt++;
622 tipc_node_calculate_timer(n, l);
623 if (n->link_cnt == 1)
624 if (!mod_timer(&n->timer, jiffies + n->keepalive_intv))
625 tipc_node_get(n);
626 }
627 memcpy(&le->maddr, maddr, sizeof(*maddr));
628 exit:
629 tipc_node_unlock(n);
630 if (reset && !tipc_link_is_reset(l))
631 tipc_node_link_down(n, b->identity, false);
632 tipc_node_put(n);
633 }
634
635 void tipc_node_delete_links(struct net *net, int bearer_id)
636 {
637 struct tipc_net *tn = net_generic(net, tipc_net_id);
638 struct tipc_node *n;
639
640 rcu_read_lock();
641 list_for_each_entry_rcu(n, &tn->node_list, list) {
642 tipc_node_link_down(n, bearer_id, true);
643 }
644 rcu_read_unlock();
645 }
646
647 static void tipc_node_reset_links(struct tipc_node *n)
648 {
649 char addr_string[16];
650 int i;
651
652 pr_warn("Resetting all links to %s\n",
653 tipc_addr_string_fill(addr_string, n->addr));
654
655 for (i = 0; i < MAX_BEARERS; i++) {
656 tipc_node_link_down(n, i, false);
657 }
658 }
659
660 /* tipc_node_fsm_evt - node finite state machine
661 * Determines when contact is allowed with peer node
662 */
663 static void tipc_node_fsm_evt(struct tipc_node *n, int evt)
664 {
665 int state = n->state;
666
667 switch (state) {
668 case SELF_DOWN_PEER_DOWN:
669 switch (evt) {
670 case SELF_ESTABL_CONTACT_EVT:
671 state = SELF_UP_PEER_COMING;
672 break;
673 case PEER_ESTABL_CONTACT_EVT:
674 state = SELF_COMING_PEER_UP;
675 break;
676 case SELF_LOST_CONTACT_EVT:
677 case PEER_LOST_CONTACT_EVT:
678 break;
679 case NODE_SYNCH_END_EVT:
680 case NODE_SYNCH_BEGIN_EVT:
681 case NODE_FAILOVER_BEGIN_EVT:
682 case NODE_FAILOVER_END_EVT:
683 default:
684 goto illegal_evt;
685 }
686 break;
687 case SELF_UP_PEER_UP:
688 switch (evt) {
689 case SELF_LOST_CONTACT_EVT:
690 state = SELF_DOWN_PEER_LEAVING;
691 break;
692 case PEER_LOST_CONTACT_EVT:
693 state = SELF_LEAVING_PEER_DOWN;
694 break;
695 case NODE_SYNCH_BEGIN_EVT:
696 state = NODE_SYNCHING;
697 break;
698 case NODE_FAILOVER_BEGIN_EVT:
699 state = NODE_FAILINGOVER;
700 break;
701 case SELF_ESTABL_CONTACT_EVT:
702 case PEER_ESTABL_CONTACT_EVT:
703 case NODE_SYNCH_END_EVT:
704 case NODE_FAILOVER_END_EVT:
705 break;
706 default:
707 goto illegal_evt;
708 }
709 break;
710 case SELF_DOWN_PEER_LEAVING:
711 switch (evt) {
712 case PEER_LOST_CONTACT_EVT:
713 state = SELF_DOWN_PEER_DOWN;
714 break;
715 case SELF_ESTABL_CONTACT_EVT:
716 case PEER_ESTABL_CONTACT_EVT:
717 case SELF_LOST_CONTACT_EVT:
718 break;
719 case NODE_SYNCH_END_EVT:
720 case NODE_SYNCH_BEGIN_EVT:
721 case NODE_FAILOVER_BEGIN_EVT:
722 case NODE_FAILOVER_END_EVT:
723 default:
724 goto illegal_evt;
725 }
726 break;
727 case SELF_UP_PEER_COMING:
728 switch (evt) {
729 case PEER_ESTABL_CONTACT_EVT:
730 state = SELF_UP_PEER_UP;
731 break;
732 case SELF_LOST_CONTACT_EVT:
733 state = SELF_DOWN_PEER_LEAVING;
734 break;
735 case SELF_ESTABL_CONTACT_EVT:
736 case PEER_LOST_CONTACT_EVT:
737 case NODE_SYNCH_END_EVT:
738 case NODE_FAILOVER_BEGIN_EVT:
739 break;
740 case NODE_SYNCH_BEGIN_EVT:
741 case NODE_FAILOVER_END_EVT:
742 default:
743 goto illegal_evt;
744 }
745 break;
746 case SELF_COMING_PEER_UP:
747 switch (evt) {
748 case SELF_ESTABL_CONTACT_EVT:
749 state = SELF_UP_PEER_UP;
750 break;
751 case PEER_LOST_CONTACT_EVT:
752 state = SELF_LEAVING_PEER_DOWN;
753 break;
754 case SELF_LOST_CONTACT_EVT:
755 case PEER_ESTABL_CONTACT_EVT:
756 break;
757 case NODE_SYNCH_END_EVT:
758 case NODE_SYNCH_BEGIN_EVT:
759 case NODE_FAILOVER_BEGIN_EVT:
760 case NODE_FAILOVER_END_EVT:
761 default:
762 goto illegal_evt;
763 }
764 break;
765 case SELF_LEAVING_PEER_DOWN:
766 switch (evt) {
767 case SELF_LOST_CONTACT_EVT:
768 state = SELF_DOWN_PEER_DOWN;
769 break;
770 case SELF_ESTABL_CONTACT_EVT:
771 case PEER_ESTABL_CONTACT_EVT:
772 case PEER_LOST_CONTACT_EVT:
773 break;
774 case NODE_SYNCH_END_EVT:
775 case NODE_SYNCH_BEGIN_EVT:
776 case NODE_FAILOVER_BEGIN_EVT:
777 case NODE_FAILOVER_END_EVT:
778 default:
779 goto illegal_evt;
780 }
781 break;
782 case NODE_FAILINGOVER:
783 switch (evt) {
784 case SELF_LOST_CONTACT_EVT:
785 state = SELF_DOWN_PEER_LEAVING;
786 break;
787 case PEER_LOST_CONTACT_EVT:
788 state = SELF_LEAVING_PEER_DOWN;
789 break;
790 case NODE_FAILOVER_END_EVT:
791 state = SELF_UP_PEER_UP;
792 break;
793 case NODE_FAILOVER_BEGIN_EVT:
794 case SELF_ESTABL_CONTACT_EVT:
795 case PEER_ESTABL_CONTACT_EVT:
796 break;
797 case NODE_SYNCH_BEGIN_EVT:
798 case NODE_SYNCH_END_EVT:
799 default:
800 goto illegal_evt;
801 }
802 break;
803 case NODE_SYNCHING:
804 switch (evt) {
805 case SELF_LOST_CONTACT_EVT:
806 state = SELF_DOWN_PEER_LEAVING;
807 break;
808 case PEER_LOST_CONTACT_EVT:
809 state = SELF_LEAVING_PEER_DOWN;
810 break;
811 case NODE_SYNCH_END_EVT:
812 state = SELF_UP_PEER_UP;
813 break;
814 case NODE_FAILOVER_BEGIN_EVT:
815 state = NODE_FAILINGOVER;
816 break;
817 case NODE_SYNCH_BEGIN_EVT:
818 case SELF_ESTABL_CONTACT_EVT:
819 case PEER_ESTABL_CONTACT_EVT:
820 break;
821 case NODE_FAILOVER_END_EVT:
822 default:
823 goto illegal_evt;
824 }
825 break;
826 default:
827 pr_err("Unknown node fsm state %x\n", state);
828 break;
829 }
830 n->state = state;
831 return;
832
833 illegal_evt:
834 pr_err("Illegal node fsm evt %x in state %x\n", evt, state);
835 }
836
837 bool tipc_node_filter_pkt(struct tipc_node *n, struct tipc_msg *hdr)
838 {
839 int state = n->state;
840
841 if (likely(state == SELF_UP_PEER_UP))
842 return true;
843
844 if (state == SELF_LEAVING_PEER_DOWN)
845 return false;
846
847 if (state == SELF_DOWN_PEER_LEAVING) {
848 if (msg_peer_node_is_up(hdr))
849 return false;
850 }
851
852 return true;
853 }
854
855 static void node_lost_contact(struct tipc_node *n,
856 struct sk_buff_head *inputq)
857 {
858 char addr_string[16];
859 struct tipc_sock_conn *conn, *safe;
860 struct tipc_link *l;
861 struct list_head *conns = &n->conn_sks;
862 struct sk_buff *skb;
863 uint i;
864
865 pr_debug("Lost contact with %s\n",
866 tipc_addr_string_fill(addr_string, n->addr));
867
868 /* Clean up broadcast state */
869 tipc_bcast_remove_peer(n->net, n->bc_entry.link);
870
871 /* Abort any ongoing link failover */
872 for (i = 0; i < MAX_BEARERS; i++) {
873 l = n->links[i].link;
874 if (l)
875 tipc_link_fsm_evt(l, LINK_FAILOVER_END_EVT);
876 }
877
878 /* Notify publications from this node */
879 n->action_flags |= TIPC_NOTIFY_NODE_DOWN;
880
881 /* Notify sockets connected to node */
882 list_for_each_entry_safe(conn, safe, conns, list) {
883 skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
884 SHORT_H_SIZE, 0, tipc_own_addr(n->net),
885 conn->peer_node, conn->port,
886 conn->peer_port, TIPC_ERR_NO_NODE);
887 if (likely(skb))
888 skb_queue_tail(inputq, skb);
889 list_del(&conn->list);
890 kfree(conn);
891 }
892 }
893
894 /**
895 * tipc_node_get_linkname - get the name of a link
896 *
897 * @bearer_id: id of the bearer
898 * @node: peer node address
899 * @linkname: link name output buffer
900 *
901 * Returns 0 on success
902 */
903 int tipc_node_get_linkname(struct net *net, u32 bearer_id, u32 addr,
904 char *linkname, size_t len)
905 {
906 struct tipc_link *link;
907 int err = -EINVAL;
908 struct tipc_node *node = tipc_node_find(net, addr);
909
910 if (!node)
911 return err;
912
913 if (bearer_id >= MAX_BEARERS)
914 goto exit;
915
916 tipc_node_lock(node);
917 link = node->links[bearer_id].link;
918 if (link) {
919 strncpy(linkname, link->name, len);
920 err = 0;
921 }
922 exit:
923 tipc_node_unlock(node);
924 tipc_node_put(node);
925 return err;
926 }
927
928 void tipc_node_unlock(struct tipc_node *node)
929 {
930 struct net *net = node->net;
931 u32 addr = 0;
932 u32 flags = node->action_flags;
933 u32 link_id = 0;
934 struct list_head *publ_list;
935
936 if (likely(!flags)) {
937 spin_unlock_bh(&node->lock);
938 return;
939 }
940
941 addr = node->addr;
942 link_id = node->link_id;
943 publ_list = &node->publ_list;
944
945 node->action_flags &= ~(TIPC_NOTIFY_NODE_DOWN | TIPC_NOTIFY_NODE_UP |
946 TIPC_NOTIFY_LINK_DOWN | TIPC_NOTIFY_LINK_UP);
947
948 spin_unlock_bh(&node->lock);
949
950 if (flags & TIPC_NOTIFY_NODE_DOWN)
951 tipc_publ_notify(net, publ_list, addr);
952
953 if (flags & TIPC_NOTIFY_NODE_UP)
954 tipc_named_node_up(net, addr);
955
956 if (flags & TIPC_NOTIFY_LINK_UP)
957 tipc_nametbl_publish(net, TIPC_LINK_STATE, addr, addr,
958 TIPC_NODE_SCOPE, link_id, addr);
959
960 if (flags & TIPC_NOTIFY_LINK_DOWN)
961 tipc_nametbl_withdraw(net, TIPC_LINK_STATE, addr,
962 link_id, addr);
963
964 }
965
966 /* Caller should hold node lock for the passed node */
967 static int __tipc_nl_add_node(struct tipc_nl_msg *msg, struct tipc_node *node)
968 {
969 void *hdr;
970 struct nlattr *attrs;
971
972 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
973 NLM_F_MULTI, TIPC_NL_NODE_GET);
974 if (!hdr)
975 return -EMSGSIZE;
976
977 attrs = nla_nest_start(msg->skb, TIPC_NLA_NODE);
978 if (!attrs)
979 goto msg_full;
980
981 if (nla_put_u32(msg->skb, TIPC_NLA_NODE_ADDR, node->addr))
982 goto attr_msg_full;
983 if (tipc_node_is_up(node))
984 if (nla_put_flag(msg->skb, TIPC_NLA_NODE_UP))
985 goto attr_msg_full;
986
987 nla_nest_end(msg->skb, attrs);
988 genlmsg_end(msg->skb, hdr);
989
990 return 0;
991
992 attr_msg_full:
993 nla_nest_cancel(msg->skb, attrs);
994 msg_full:
995 genlmsg_cancel(msg->skb, hdr);
996
997 return -EMSGSIZE;
998 }
999
1000 static struct tipc_link *tipc_node_select_link(struct tipc_node *n, int sel,
1001 int *bearer_id,
1002 struct tipc_media_addr **maddr)
1003 {
1004 int id = n->active_links[sel & 1];
1005
1006 if (unlikely(id < 0))
1007 return NULL;
1008
1009 *bearer_id = id;
1010 *maddr = &n->links[id].maddr;
1011 return n->links[id].link;
1012 }
1013
1014 /**
1015 * tipc_node_xmit() is the general link level function for message sending
1016 * @net: the applicable net namespace
1017 * @list: chain of buffers containing message
1018 * @dnode: address of destination node
1019 * @selector: a number used for deterministic link selection
1020 * Consumes the buffer chain, except when returning -ELINKCONG
1021 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
1022 */
1023 int tipc_node_xmit(struct net *net, struct sk_buff_head *list,
1024 u32 dnode, int selector)
1025 {
1026 struct tipc_link *l = NULL;
1027 struct tipc_node *n;
1028 struct sk_buff_head xmitq;
1029 struct tipc_media_addr *maddr;
1030 int bearer_id;
1031 int rc = -EHOSTUNREACH;
1032
1033 __skb_queue_head_init(&xmitq);
1034 n = tipc_node_find(net, dnode);
1035 if (likely(n)) {
1036 tipc_node_lock(n);
1037 l = tipc_node_select_link(n, selector, &bearer_id, &maddr);
1038 if (likely(l))
1039 rc = tipc_link_xmit(l, list, &xmitq);
1040 tipc_node_unlock(n);
1041 if (unlikely(rc == -ENOBUFS))
1042 tipc_node_link_down(n, bearer_id, false);
1043 tipc_node_put(n);
1044 }
1045 if (likely(!rc)) {
1046 tipc_bearer_xmit(net, bearer_id, &xmitq, maddr);
1047 return 0;
1048 }
1049 if (likely(in_own_node(net, dnode))) {
1050 tipc_sk_rcv(net, list);
1051 return 0;
1052 }
1053 return rc;
1054 }
1055
1056 /* tipc_node_xmit_skb(): send single buffer to destination
1057 * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
1058 * messages, which will not be rejected
1059 * The only exception is datagram messages rerouted after secondary
1060 * lookup, which are rare and safe to dispose of anyway.
1061 * TODO: Return real return value, and let callers use
1062 * tipc_wait_for_sendpkt() where applicable
1063 */
1064 int tipc_node_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
1065 u32 selector)
1066 {
1067 struct sk_buff_head head;
1068 int rc;
1069
1070 skb_queue_head_init(&head);
1071 __skb_queue_tail(&head, skb);
1072 rc = tipc_node_xmit(net, &head, dnode, selector);
1073 if (rc == -ELINKCONG)
1074 kfree_skb(skb);
1075 return 0;
1076 }
1077
1078 /**
1079 * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node
1080 * @net: the applicable net namespace
1081 * @skb: TIPC packet
1082 * @bearer_id: id of bearer message arrived on
1083 *
1084 * Invoked with no locks held.
1085 */
1086 static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id)
1087 {
1088 int rc;
1089 struct sk_buff_head xmitq;
1090 struct tipc_bclink_entry *be;
1091 struct tipc_link_entry *le;
1092 struct tipc_msg *hdr = buf_msg(skb);
1093 int usr = msg_user(hdr);
1094 u32 dnode = msg_destnode(hdr);
1095 struct tipc_node *n;
1096
1097 __skb_queue_head_init(&xmitq);
1098
1099 /* If NACK for other node, let rcv link for that node peek into it */
1100 if ((usr == BCAST_PROTOCOL) && (dnode != tipc_own_addr(net)))
1101 n = tipc_node_find(net, dnode);
1102 else
1103 n = tipc_node_find(net, msg_prevnode(hdr));
1104 if (!n) {
1105 kfree_skb(skb);
1106 return;
1107 }
1108 be = &n->bc_entry;
1109 le = &n->links[bearer_id];
1110
1111 rc = tipc_bcast_rcv(net, be->link, skb);
1112
1113 /* Broadcast link reset may happen at reassembly failure */
1114 if (rc & TIPC_LINK_DOWN_EVT)
1115 tipc_node_reset_links(n);
1116
1117 /* Broadcast ACKs are sent on a unicast link */
1118 if (rc & TIPC_LINK_SND_BC_ACK) {
1119 tipc_node_lock(n);
1120 tipc_link_build_ack_msg(le->link, &xmitq);
1121 tipc_node_unlock(n);
1122 }
1123
1124 if (!skb_queue_empty(&xmitq))
1125 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1126
1127 /* Deliver. 'arrvq' is under inputq2's lock protection */
1128 if (!skb_queue_empty(&be->inputq1)) {
1129 spin_lock_bh(&be->inputq2.lock);
1130 spin_lock_bh(&be->inputq1.lock);
1131 skb_queue_splice_tail_init(&be->inputq1, &be->arrvq);
1132 spin_unlock_bh(&be->inputq1.lock);
1133 spin_unlock_bh(&be->inputq2.lock);
1134 tipc_sk_mcast_rcv(net, &be->arrvq, &be->inputq2);
1135 }
1136 tipc_node_put(n);
1137 }
1138
1139 /**
1140 * tipc_node_check_state - check and if necessary update node state
1141 * @skb: TIPC packet
1142 * @bearer_id: identity of bearer delivering the packet
1143 * Returns true if state is ok, otherwise consumes buffer and returns false
1144 */
1145 static bool tipc_node_check_state(struct tipc_node *n, struct sk_buff *skb,
1146 int bearer_id, struct sk_buff_head *xmitq)
1147 {
1148 struct tipc_msg *hdr = buf_msg(skb);
1149 int usr = msg_user(hdr);
1150 int mtyp = msg_type(hdr);
1151 u16 oseqno = msg_seqno(hdr);
1152 u16 iseqno = msg_seqno(msg_get_wrapped(hdr));
1153 u16 exp_pkts = msg_msgcnt(hdr);
1154 u16 rcv_nxt, syncpt, dlv_nxt;
1155 int state = n->state;
1156 struct tipc_link *l, *tnl, *pl = NULL;
1157 struct tipc_media_addr *maddr;
1158 int i, pb_id;
1159
1160 l = n->links[bearer_id].link;
1161 if (!l)
1162 return false;
1163 rcv_nxt = l->rcv_nxt;
1164
1165
1166 if (likely((state == SELF_UP_PEER_UP) && (usr != TUNNEL_PROTOCOL)))
1167 return true;
1168
1169 /* Find parallel link, if any */
1170 for (i = 0; i < MAX_BEARERS; i++) {
1171 if ((i != bearer_id) && n->links[i].link) {
1172 pl = n->links[i].link;
1173 break;
1174 }
1175 }
1176
1177 /* Update node accesibility if applicable */
1178 if (state == SELF_UP_PEER_COMING) {
1179 if (!tipc_link_is_up(l))
1180 return true;
1181 if (!msg_peer_link_is_up(hdr))
1182 return true;
1183 tipc_node_fsm_evt(n, PEER_ESTABL_CONTACT_EVT);
1184 }
1185
1186 if (state == SELF_DOWN_PEER_LEAVING) {
1187 if (msg_peer_node_is_up(hdr))
1188 return false;
1189 tipc_node_fsm_evt(n, PEER_LOST_CONTACT_EVT);
1190 }
1191
1192 /* Ignore duplicate packets */
1193 if ((usr != LINK_PROTOCOL) && less(oseqno, rcv_nxt))
1194 return true;
1195
1196 /* Initiate or update failover mode if applicable */
1197 if ((usr == TUNNEL_PROTOCOL) && (mtyp == FAILOVER_MSG)) {
1198 syncpt = oseqno + exp_pkts - 1;
1199 if (pl && tipc_link_is_up(pl)) {
1200 pb_id = pl->bearer_id;
1201 __tipc_node_link_down(n, &pb_id, xmitq, &maddr);
1202 tipc_skb_queue_splice_tail_init(pl->inputq, l->inputq);
1203 }
1204 /* If pkts arrive out of order, use lowest calculated syncpt */
1205 if (less(syncpt, n->sync_point))
1206 n->sync_point = syncpt;
1207 }
1208
1209 /* Open parallel link when tunnel link reaches synch point */
1210 if ((n->state == NODE_FAILINGOVER) && tipc_link_is_up(l)) {
1211 if (!more(rcv_nxt, n->sync_point))
1212 return true;
1213 tipc_node_fsm_evt(n, NODE_FAILOVER_END_EVT);
1214 if (pl)
1215 tipc_link_fsm_evt(pl, LINK_FAILOVER_END_EVT);
1216 return true;
1217 }
1218
1219 /* No synching needed if only one link */
1220 if (!pl || !tipc_link_is_up(pl))
1221 return true;
1222
1223 /* Initiate synch mode if applicable */
1224 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG) && (oseqno == 1)) {
1225 syncpt = iseqno + exp_pkts - 1;
1226 if (!tipc_link_is_up(l)) {
1227 tipc_link_fsm_evt(l, LINK_ESTABLISH_EVT);
1228 __tipc_node_link_up(n, bearer_id, xmitq);
1229 }
1230 if (n->state == SELF_UP_PEER_UP) {
1231 n->sync_point = syncpt;
1232 tipc_link_fsm_evt(l, LINK_SYNCH_BEGIN_EVT);
1233 tipc_node_fsm_evt(n, NODE_SYNCH_BEGIN_EVT);
1234 }
1235 if (less(syncpt, n->sync_point))
1236 n->sync_point = syncpt;
1237 }
1238
1239 /* Open tunnel link when parallel link reaches synch point */
1240 if ((n->state == NODE_SYNCHING) && tipc_link_is_synching(l)) {
1241 if (tipc_link_is_synching(l)) {
1242 tnl = l;
1243 } else {
1244 tnl = pl;
1245 pl = l;
1246 }
1247 dlv_nxt = pl->rcv_nxt - mod(skb_queue_len(pl->inputq));
1248 if (more(dlv_nxt, n->sync_point)) {
1249 tipc_link_fsm_evt(tnl, LINK_SYNCH_END_EVT);
1250 tipc_node_fsm_evt(n, NODE_SYNCH_END_EVT);
1251 return true;
1252 }
1253 if (l == pl)
1254 return true;
1255 if ((usr == TUNNEL_PROTOCOL) && (mtyp == SYNCH_MSG))
1256 return true;
1257 if (usr == LINK_PROTOCOL)
1258 return true;
1259 return false;
1260 }
1261 return true;
1262 }
1263
1264 /**
1265 * tipc_rcv - process TIPC packets/messages arriving from off-node
1266 * @net: the applicable net namespace
1267 * @skb: TIPC packet
1268 * @bearer: pointer to bearer message arrived on
1269 *
1270 * Invoked with no locks held. Bearer pointer must point to a valid bearer
1271 * structure (i.e. cannot be NULL), but bearer can be inactive.
1272 */
1273 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
1274 {
1275 struct sk_buff_head xmitq;
1276 struct tipc_node *n;
1277 struct tipc_msg *hdr = buf_msg(skb);
1278 int usr = msg_user(hdr);
1279 int bearer_id = b->identity;
1280 struct tipc_link_entry *le;
1281 u16 bc_ack = msg_bcast_ack(hdr);
1282 int rc = 0;
1283
1284 __skb_queue_head_init(&xmitq);
1285
1286 /* Ensure message is well-formed */
1287 if (unlikely(!tipc_msg_validate(skb)))
1288 goto discard;
1289
1290 /* Handle arrival of discovery or broadcast packet */
1291 if (unlikely(msg_non_seq(hdr))) {
1292 if (unlikely(usr == LINK_CONFIG))
1293 return tipc_disc_rcv(net, skb, b);
1294 else
1295 return tipc_node_bc_rcv(net, skb, bearer_id);
1296 }
1297
1298 /* Locate neighboring node that sent packet */
1299 n = tipc_node_find(net, msg_prevnode(hdr));
1300 if (unlikely(!n))
1301 goto discard;
1302 le = &n->links[bearer_id];
1303
1304 /* Ensure broadcast reception is in synch with peer's send state */
1305 if (unlikely(usr == LINK_PROTOCOL))
1306 tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr);
1307 else if (unlikely(n->bc_entry.link->acked != bc_ack))
1308 tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack);
1309
1310 tipc_node_lock(n);
1311
1312 /* Is reception permitted at the moment ? */
1313 if (!tipc_node_filter_pkt(n, hdr))
1314 goto unlock;
1315
1316 /* Check and if necessary update node state */
1317 if (likely(tipc_node_check_state(n, skb, bearer_id, &xmitq))) {
1318 rc = tipc_link_rcv(le->link, skb, &xmitq);
1319 skb = NULL;
1320 }
1321 unlock:
1322 tipc_node_unlock(n);
1323
1324 if (unlikely(rc & TIPC_LINK_UP_EVT))
1325 tipc_node_link_up(n, bearer_id, &xmitq);
1326
1327 if (unlikely(rc & TIPC_LINK_DOWN_EVT))
1328 tipc_node_link_down(n, bearer_id, false);
1329
1330 if (unlikely(!skb_queue_empty(&n->bc_entry.namedq)))
1331 tipc_named_rcv(net, &n->bc_entry.namedq);
1332
1333 if (!skb_queue_empty(&le->inputq))
1334 tipc_sk_rcv(net, &le->inputq);
1335
1336 if (!skb_queue_empty(&xmitq))
1337 tipc_bearer_xmit(net, bearer_id, &xmitq, &le->maddr);
1338
1339 tipc_node_put(n);
1340 discard:
1341 kfree_skb(skb);
1342 }
1343
1344 int tipc_nl_node_dump(struct sk_buff *skb, struct netlink_callback *cb)
1345 {
1346 int err;
1347 struct net *net = sock_net(skb->sk);
1348 struct tipc_net *tn = net_generic(net, tipc_net_id);
1349 int done = cb->args[0];
1350 int last_addr = cb->args[1];
1351 struct tipc_node *node;
1352 struct tipc_nl_msg msg;
1353
1354 if (done)
1355 return 0;
1356
1357 msg.skb = skb;
1358 msg.portid = NETLINK_CB(cb->skb).portid;
1359 msg.seq = cb->nlh->nlmsg_seq;
1360
1361 rcu_read_lock();
1362 if (last_addr) {
1363 node = tipc_node_find(net, last_addr);
1364 if (!node) {
1365 rcu_read_unlock();
1366 /* We never set seq or call nl_dump_check_consistent()
1367 * this means that setting prev_seq here will cause the
1368 * consistence check to fail in the netlink callback
1369 * handler. Resulting in the NLMSG_DONE message having
1370 * the NLM_F_DUMP_INTR flag set if the node state
1371 * changed while we released the lock.
1372 */
1373 cb->prev_seq = 1;
1374 return -EPIPE;
1375 }
1376 tipc_node_put(node);
1377 }
1378
1379 list_for_each_entry_rcu(node, &tn->node_list, list) {
1380 if (last_addr) {
1381 if (node->addr == last_addr)
1382 last_addr = 0;
1383 else
1384 continue;
1385 }
1386
1387 tipc_node_lock(node);
1388 err = __tipc_nl_add_node(&msg, node);
1389 if (err) {
1390 last_addr = node->addr;
1391 tipc_node_unlock(node);
1392 goto out;
1393 }
1394
1395 tipc_node_unlock(node);
1396 }
1397 done = 1;
1398 out:
1399 cb->args[0] = done;
1400 cb->args[1] = last_addr;
1401 rcu_read_unlock();
1402
1403 return skb->len;
1404 }
Linux kernel - Deliverables
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