1 /*
2 * net/tipc/link.c: TIPC link code
3 *
4 * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
5 * Copyright (c) 2004-2007, 2010-2013, 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 "subscr.h"
39 #include "link.h"
40 #include "bcast.h"
41 #include "socket.h"
42 #include "name_distr.h"
43 #include "discover.h"
44 #include "netlink.h"
45
46 #include <linux/pkt_sched.h>
47
48 /*
49 * Error message prefixes
50 */
51 static const char *link_co_err = "Link tunneling error, ";
52 static const char *link_rst_msg = "Resetting link ";
53 static const char tipc_bclink_name[] = "broadcast-link";
54
55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
56 [TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC },
57 [TIPC_NLA_LINK_NAME] = {
58 .type = NLA_STRING,
59 .len = TIPC_MAX_LINK_NAME
60 },
61 [TIPC_NLA_LINK_MTU] = { .type = NLA_U32 },
62 [TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG },
63 [TIPC_NLA_LINK_UP] = { .type = NLA_FLAG },
64 [TIPC_NLA_LINK_ACTIVE] = { .type = NLA_FLAG },
65 [TIPC_NLA_LINK_PROP] = { .type = NLA_NESTED },
66 [TIPC_NLA_LINK_STATS] = { .type = NLA_NESTED },
67 [TIPC_NLA_LINK_RX] = { .type = NLA_U32 },
68 [TIPC_NLA_LINK_TX] = { .type = NLA_U32 }
69 };
70
71 /* Properties valid for media, bearar and link */
72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
73 [TIPC_NLA_PROP_UNSPEC] = { .type = NLA_UNSPEC },
74 [TIPC_NLA_PROP_PRIO] = { .type = NLA_U32 },
75 [TIPC_NLA_PROP_TOL] = { .type = NLA_U32 },
76 [TIPC_NLA_PROP_WIN] = { .type = NLA_U32 }
77 };
78
79 /* Send states for broadcast NACKs
80 */
81 enum {
82 BC_NACK_SND_CONDITIONAL,
83 BC_NACK_SND_UNCONDITIONAL,
84 BC_NACK_SND_SUPPRESS,
85 };
86
87 /*
88 * Interval between NACKs when packets arrive out of order
89 */
90 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
91 /*
92 * Out-of-range value for link session numbers
93 */
94 #define WILDCARD_SESSION 0x10000
95
96 /* Link FSM states:
97 */
98 enum {
99 LINK_ESTABLISHED = 0xe,
100 LINK_ESTABLISHING = 0xe << 4,
101 LINK_RESET = 0x1 << 8,
102 LINK_RESETTING = 0x2 << 12,
103 LINK_PEER_RESET = 0xd << 16,
104 LINK_FAILINGOVER = 0xf << 20,
105 LINK_SYNCHING = 0xc << 24
106 };
107
108 /* Link FSM state checking routines
109 */
110 static int link_is_up(struct tipc_link *l)
111 {
112 return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
113 }
114
115 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
116 struct sk_buff_head *xmitq);
117 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
118 u16 rcvgap, int tolerance, int priority,
119 struct sk_buff_head *xmitq);
120 static void link_reset_statistics(struct tipc_link *l_ptr);
121 static void link_print(struct tipc_link *l_ptr, const char *str);
122 static void tipc_link_build_nack_msg(struct tipc_link *l,
123 struct sk_buff_head *xmitq);
124 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
125 struct sk_buff_head *xmitq);
126 static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
127
128 /*
129 * Simple non-static link routines (i.e. referenced outside this file)
130 */
131 bool tipc_link_is_up(struct tipc_link *l)
132 {
133 return link_is_up(l);
134 }
135
136 bool tipc_link_peer_is_down(struct tipc_link *l)
137 {
138 return l->state == LINK_PEER_RESET;
139 }
140
141 bool tipc_link_is_reset(struct tipc_link *l)
142 {
143 return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
144 }
145
146 bool tipc_link_is_establishing(struct tipc_link *l)
147 {
148 return l->state == LINK_ESTABLISHING;
149 }
150
151 bool tipc_link_is_synching(struct tipc_link *l)
152 {
153 return l->state == LINK_SYNCHING;
154 }
155
156 bool tipc_link_is_failingover(struct tipc_link *l)
157 {
158 return l->state == LINK_FAILINGOVER;
159 }
160
161 bool tipc_link_is_blocked(struct tipc_link *l)
162 {
163 return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
164 }
165
166 static bool link_is_bc_sndlink(struct tipc_link *l)
167 {
168 return !l->bc_sndlink;
169 }
170
171 static bool link_is_bc_rcvlink(struct tipc_link *l)
172 {
173 return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
174 }
175
176 int tipc_link_is_active(struct tipc_link *l)
177 {
178 return l->active;
179 }
180
181 void tipc_link_set_active(struct tipc_link *l, bool active)
182 {
183 l->active = active;
184 }
185
186 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
187 struct tipc_link *uc_l,
188 struct sk_buff_head *xmitq)
189 {
190 struct tipc_link *rcv_l = uc_l->bc_rcvlink;
191
192 snd_l->ackers++;
193 rcv_l->acked = snd_l->snd_nxt - 1;
194 snd_l->state = LINK_ESTABLISHED;
195 tipc_link_build_bc_init_msg(uc_l, xmitq);
196 }
197
198 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
199 struct tipc_link *rcv_l,
200 struct sk_buff_head *xmitq)
201 {
202 u16 ack = snd_l->snd_nxt - 1;
203
204 snd_l->ackers--;
205 tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
206 tipc_link_reset(rcv_l);
207 rcv_l->state = LINK_RESET;
208 if (!snd_l->ackers) {
209 tipc_link_reset(snd_l);
210 snd_l->state = LINK_RESET;
211 __skb_queue_purge(xmitq);
212 }
213 }
214
215 int tipc_link_bc_peers(struct tipc_link *l)
216 {
217 return l->ackers;
218 }
219
220 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
221 {
222 l->mtu = mtu;
223 }
224
225 int tipc_link_mtu(struct tipc_link *l)
226 {
227 return l->mtu;
228 }
229
230 static u32 link_own_addr(struct tipc_link *l)
231 {
232 return msg_prevnode(l->pmsg);
233 }
234
235 /**
236 * tipc_link_create - create a new link
237 * @n: pointer to associated node
238 * @if_name: associated interface name
239 * @bearer_id: id (index) of associated bearer
240 * @tolerance: link tolerance to be used by link
241 * @net_plane: network plane (A,B,c..) this link belongs to
242 * @mtu: mtu to be advertised by link
243 * @priority: priority to be used by link
244 * @window: send window to be used by link
245 * @session: session to be used by link
246 * @ownnode: identity of own node
247 * @peer: node id of peer node
248 * @peer_caps: bitmap describing peer node capabilities
249 * @bc_sndlink: the namespace global link used for broadcast sending
250 * @bc_rcvlink: the peer specific link used for broadcast reception
251 * @inputq: queue to put messages ready for delivery
252 * @namedq: queue to put binding table update messages ready for delivery
253 * @link: return value, pointer to put the created link
254 *
255 * Returns true if link was created, otherwise false
256 */
257 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
258 int tolerance, char net_plane, u32 mtu, int priority,
259 int window, u32 session, u32 ownnode, u32 peer,
260 u16 peer_caps,
261 struct tipc_link *bc_sndlink,
262 struct tipc_link *bc_rcvlink,
263 struct sk_buff_head *inputq,
264 struct sk_buff_head *namedq,
265 struct tipc_link **link)
266 {
267 struct tipc_link *l;
268 struct tipc_msg *hdr;
269
270 l = kzalloc(sizeof(*l), GFP_ATOMIC);
271 if (!l)
272 return false;
273 *link = l;
274 l->pmsg = (struct tipc_msg *)&l->proto_msg;
275 hdr = l->pmsg;
276 tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
277 msg_set_size(hdr, sizeof(l->proto_msg));
278 msg_set_session(hdr, session);
279 msg_set_bearer_id(hdr, l->bearer_id);
280
281 /* Note: peer i/f name is completed by reset/activate message */
282 sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
283 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
284 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
285 strcpy((char *)msg_data(hdr), if_name);
286
287 l->addr = peer;
288 l->peer_caps = peer_caps;
289 l->net = net;
290 l->peer_session = WILDCARD_SESSION;
291 l->bearer_id = bearer_id;
292 l->tolerance = tolerance;
293 l->net_plane = net_plane;
294 l->advertised_mtu = mtu;
295 l->mtu = mtu;
296 l->priority = priority;
297 tipc_link_set_queue_limits(l, window);
298 l->ackers = 1;
299 l->bc_sndlink = bc_sndlink;
300 l->bc_rcvlink = bc_rcvlink;
301 l->inputq = inputq;
302 l->namedq = namedq;
303 l->state = LINK_RESETTING;
304 __skb_queue_head_init(&l->transmq);
305 __skb_queue_head_init(&l->backlogq);
306 __skb_queue_head_init(&l->deferdq);
307 skb_queue_head_init(&l->wakeupq);
308 skb_queue_head_init(l->inputq);
309 return true;
310 }
311
312 /**
313 * tipc_link_bc_create - create new link to be used for broadcast
314 * @n: pointer to associated node
315 * @mtu: mtu to be used
316 * @window: send window to be used
317 * @inputq: queue to put messages ready for delivery
318 * @namedq: queue to put binding table update messages ready for delivery
319 * @link: return value, pointer to put the created link
320 *
321 * Returns true if link was created, otherwise false
322 */
323 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
324 int mtu, int window, u16 peer_caps,
325 struct sk_buff_head *inputq,
326 struct sk_buff_head *namedq,
327 struct tipc_link *bc_sndlink,
328 struct tipc_link **link)
329 {
330 struct tipc_link *l;
331
332 if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
333 0, ownnode, peer, peer_caps, bc_sndlink,
334 NULL, inputq, namedq, link))
335 return false;
336
337 l = *link;
338 strcpy(l->name, tipc_bclink_name);
339 tipc_link_reset(l);
340 l->state = LINK_RESET;
341 l->ackers = 0;
342 l->bc_rcvlink = l;
343
344 /* Broadcast send link is always up */
345 if (link_is_bc_sndlink(l))
346 l->state = LINK_ESTABLISHED;
347
348 return true;
349 }
350
351 /**
352 * tipc_link_fsm_evt - link finite state machine
353 * @l: pointer to link
354 * @evt: state machine event to be processed
355 */
356 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
357 {
358 int rc = 0;
359
360 switch (l->state) {
361 case LINK_RESETTING:
362 switch (evt) {
363 case LINK_PEER_RESET_EVT:
364 l->state = LINK_PEER_RESET;
365 break;
366 case LINK_RESET_EVT:
367 l->state = LINK_RESET;
368 break;
369 case LINK_FAILURE_EVT:
370 case LINK_FAILOVER_BEGIN_EVT:
371 case LINK_ESTABLISH_EVT:
372 case LINK_FAILOVER_END_EVT:
373 case LINK_SYNCH_BEGIN_EVT:
374 case LINK_SYNCH_END_EVT:
375 default:
376 goto illegal_evt;
377 }
378 break;
379 case LINK_RESET:
380 switch (evt) {
381 case LINK_PEER_RESET_EVT:
382 l->state = LINK_ESTABLISHING;
383 break;
384 case LINK_FAILOVER_BEGIN_EVT:
385 l->state = LINK_FAILINGOVER;
386 case LINK_FAILURE_EVT:
387 case LINK_RESET_EVT:
388 case LINK_ESTABLISH_EVT:
389 case LINK_FAILOVER_END_EVT:
390 break;
391 case LINK_SYNCH_BEGIN_EVT:
392 case LINK_SYNCH_END_EVT:
393 default:
394 goto illegal_evt;
395 }
396 break;
397 case LINK_PEER_RESET:
398 switch (evt) {
399 case LINK_RESET_EVT:
400 l->state = LINK_ESTABLISHING;
401 break;
402 case LINK_PEER_RESET_EVT:
403 case LINK_ESTABLISH_EVT:
404 case LINK_FAILURE_EVT:
405 break;
406 case LINK_SYNCH_BEGIN_EVT:
407 case LINK_SYNCH_END_EVT:
408 case LINK_FAILOVER_BEGIN_EVT:
409 case LINK_FAILOVER_END_EVT:
410 default:
411 goto illegal_evt;
412 }
413 break;
414 case LINK_FAILINGOVER:
415 switch (evt) {
416 case LINK_FAILOVER_END_EVT:
417 l->state = LINK_RESET;
418 break;
419 case LINK_PEER_RESET_EVT:
420 case LINK_RESET_EVT:
421 case LINK_ESTABLISH_EVT:
422 case LINK_FAILURE_EVT:
423 break;
424 case LINK_FAILOVER_BEGIN_EVT:
425 case LINK_SYNCH_BEGIN_EVT:
426 case LINK_SYNCH_END_EVT:
427 default:
428 goto illegal_evt;
429 }
430 break;
431 case LINK_ESTABLISHING:
432 switch (evt) {
433 case LINK_ESTABLISH_EVT:
434 l->state = LINK_ESTABLISHED;
435 break;
436 case LINK_FAILOVER_BEGIN_EVT:
437 l->state = LINK_FAILINGOVER;
438 break;
439 case LINK_RESET_EVT:
440 l->state = LINK_RESET;
441 break;
442 case LINK_FAILURE_EVT:
443 case LINK_PEER_RESET_EVT:
444 case LINK_SYNCH_BEGIN_EVT:
445 case LINK_FAILOVER_END_EVT:
446 break;
447 case LINK_SYNCH_END_EVT:
448 default:
449 goto illegal_evt;
450 }
451 break;
452 case LINK_ESTABLISHED:
453 switch (evt) {
454 case LINK_PEER_RESET_EVT:
455 l->state = LINK_PEER_RESET;
456 rc |= TIPC_LINK_DOWN_EVT;
457 break;
458 case LINK_FAILURE_EVT:
459 l->state = LINK_RESETTING;
460 rc |= TIPC_LINK_DOWN_EVT;
461 break;
462 case LINK_RESET_EVT:
463 l->state = LINK_RESET;
464 break;
465 case LINK_ESTABLISH_EVT:
466 case LINK_SYNCH_END_EVT:
467 break;
468 case LINK_SYNCH_BEGIN_EVT:
469 l->state = LINK_SYNCHING;
470 break;
471 case LINK_FAILOVER_BEGIN_EVT:
472 case LINK_FAILOVER_END_EVT:
473 default:
474 goto illegal_evt;
475 }
476 break;
477 case LINK_SYNCHING:
478 switch (evt) {
479 case LINK_PEER_RESET_EVT:
480 l->state = LINK_PEER_RESET;
481 rc |= TIPC_LINK_DOWN_EVT;
482 break;
483 case LINK_FAILURE_EVT:
484 l->state = LINK_RESETTING;
485 rc |= TIPC_LINK_DOWN_EVT;
486 break;
487 case LINK_RESET_EVT:
488 l->state = LINK_RESET;
489 break;
490 case LINK_ESTABLISH_EVT:
491 case LINK_SYNCH_BEGIN_EVT:
492 break;
493 case LINK_SYNCH_END_EVT:
494 l->state = LINK_ESTABLISHED;
495 break;
496 case LINK_FAILOVER_BEGIN_EVT:
497 case LINK_FAILOVER_END_EVT:
498 default:
499 goto illegal_evt;
500 }
501 break;
502 default:
503 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
504 }
505 return rc;
506 illegal_evt:
507 pr_err("Illegal FSM event %x in state %x on link %s\n",
508 evt, l->state, l->name);
509 return rc;
510 }
511
512 /* link_profile_stats - update statistical profiling of traffic
513 */
514 static void link_profile_stats(struct tipc_link *l)
515 {
516 struct sk_buff *skb;
517 struct tipc_msg *msg;
518 int length;
519
520 /* Update counters used in statistical profiling of send traffic */
521 l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
522 l->stats.queue_sz_counts++;
523
524 skb = skb_peek(&l->transmq);
525 if (!skb)
526 return;
527 msg = buf_msg(skb);
528 length = msg_size(msg);
529
530 if (msg_user(msg) == MSG_FRAGMENTER) {
531 if (msg_type(msg) != FIRST_FRAGMENT)
532 return;
533 length = msg_size(msg_get_wrapped(msg));
534 }
535 l->stats.msg_lengths_total += length;
536 l->stats.msg_length_counts++;
537 if (length <= 64)
538 l->stats.msg_length_profile[0]++;
539 else if (length <= 256)
540 l->stats.msg_length_profile[1]++;
541 else if (length <= 1024)
542 l->stats.msg_length_profile[2]++;
543 else if (length <= 4096)
544 l->stats.msg_length_profile[3]++;
545 else if (length <= 16384)
546 l->stats.msg_length_profile[4]++;
547 else if (length <= 32768)
548 l->stats.msg_length_profile[5]++;
549 else
550 l->stats.msg_length_profile[6]++;
551 }
552
553 /* tipc_link_timeout - perform periodic task as instructed from node timeout
554 */
555 /* tipc_link_timeout - perform periodic task as instructed from node timeout
556 */
557 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
558 {
559 int rc = 0;
560 int mtyp = STATE_MSG;
561 bool xmit = false;
562 bool prb = false;
563 u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
564 u16 bc_acked = l->bc_rcvlink->acked;
565 bool bc_up = link_is_up(l->bc_rcvlink);
566
567 link_profile_stats(l);
568
569 switch (l->state) {
570 case LINK_ESTABLISHED:
571 case LINK_SYNCHING:
572 if (!l->silent_intv_cnt) {
573 if (bc_up && (bc_acked != bc_snt))
574 xmit = true;
575 } else if (l->silent_intv_cnt <= l->abort_limit) {
576 xmit = true;
577 prb = true;
578 } else {
579 rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
580 }
581 l->silent_intv_cnt++;
582 break;
583 case LINK_RESET:
584 xmit = true;
585 mtyp = RESET_MSG;
586 break;
587 case LINK_ESTABLISHING:
588 xmit = true;
589 mtyp = ACTIVATE_MSG;
590 break;
591 case LINK_PEER_RESET:
592 case LINK_RESETTING:
593 case LINK_FAILINGOVER:
594 break;
595 default:
596 break;
597 }
598
599 if (xmit)
600 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
601
602 return rc;
603 }
604
605 /**
606 * link_schedule_user - schedule a message sender for wakeup after congestion
607 * @link: congested link
608 * @list: message that was attempted sent
609 * Create pseudo msg to send back to user when congestion abates
610 * Does not consume buffer list
611 */
612 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
613 {
614 struct tipc_msg *msg = buf_msg(skb_peek(list));
615 int imp = msg_importance(msg);
616 u32 oport = msg_origport(msg);
617 u32 addr = link_own_addr(link);
618 struct sk_buff *skb;
619
620 /* This really cannot happen... */
621 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
622 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
623 return -ENOBUFS;
624 }
625 /* Non-blocking sender: */
626 if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
627 return -ELINKCONG;
628
629 /* Create and schedule wakeup pseudo message */
630 skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
631 addr, addr, oport, 0, 0);
632 if (!skb)
633 return -ENOBUFS;
634 TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
635 TIPC_SKB_CB(skb)->chain_imp = imp;
636 skb_queue_tail(&link->wakeupq, skb);
637 link->stats.link_congs++;
638 return -ELINKCONG;
639 }
640
641 /**
642 * link_prepare_wakeup - prepare users for wakeup after congestion
643 * @link: congested link
644 * Move a number of waiting users, as permitted by available space in
645 * the send queue, from link wait queue to node wait queue for wakeup
646 */
647 void link_prepare_wakeup(struct tipc_link *l)
648 {
649 int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
650 int imp, lim;
651 struct sk_buff *skb, *tmp;
652
653 skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
654 imp = TIPC_SKB_CB(skb)->chain_imp;
655 lim = l->window + l->backlog[imp].limit;
656 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
657 if ((pnd[imp] + l->backlog[imp].len) >= lim)
658 break;
659 skb_unlink(skb, &l->wakeupq);
660 skb_queue_tail(l->inputq, skb);
661 }
662 }
663
664 void tipc_link_reset(struct tipc_link *l)
665 {
666 /* Link is down, accept any session */
667 l->peer_session = WILDCARD_SESSION;
668
669 /* If peer is up, it only accepts an incremented session number */
670 msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
671
672 /* Prepare for renewed mtu size negotiation */
673 l->mtu = l->advertised_mtu;
674
675 /* Clean up all queues and counters: */
676 __skb_queue_purge(&l->transmq);
677 __skb_queue_purge(&l->deferdq);
678 skb_queue_splice_init(&l->wakeupq, l->inputq);
679 __skb_queue_purge(&l->backlogq);
680 l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
681 l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
682 l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
683 l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
684 l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
685 kfree_skb(l->reasm_buf);
686 kfree_skb(l->failover_reasm_skb);
687 l->reasm_buf = NULL;
688 l->failover_reasm_skb = NULL;
689 l->rcv_unacked = 0;
690 l->snd_nxt = 1;
691 l->rcv_nxt = 1;
692 l->acked = 0;
693 l->silent_intv_cnt = 0;
694 l->stats.recv_info = 0;
695 l->stale_count = 0;
696 l->bc_peer_is_up = false;
697 link_reset_statistics(l);
698 }
699
700 /**
701 * tipc_link_xmit(): enqueue buffer list according to queue situation
702 * @link: link to use
703 * @list: chain of buffers containing message
704 * @xmitq: returned list of packets to be sent by caller
705 *
706 * Consumes the buffer chain, except when returning -ELINKCONG,
707 * since the caller then may want to make more send attempts.
708 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
709 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
710 */
711 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
712 struct sk_buff_head *xmitq)
713 {
714 struct tipc_msg *hdr = buf_msg(skb_peek(list));
715 unsigned int maxwin = l->window;
716 unsigned int i, imp = msg_importance(hdr);
717 unsigned int mtu = l->mtu;
718 u16 ack = l->rcv_nxt - 1;
719 u16 seqno = l->snd_nxt;
720 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
721 struct sk_buff_head *transmq = &l->transmq;
722 struct sk_buff_head *backlogq = &l->backlogq;
723 struct sk_buff *skb, *_skb, *bskb;
724
725 /* Match msg importance against this and all higher backlog limits: */
726 for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
727 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
728 return link_schedule_user(l, list);
729 }
730 if (unlikely(msg_size(hdr) > mtu))
731 return -EMSGSIZE;
732
733 /* Prepare each packet for sending, and add to relevant queue: */
734 while (skb_queue_len(list)) {
735 skb = skb_peek(list);
736 hdr = buf_msg(skb);
737 msg_set_seqno(hdr, seqno);
738 msg_set_ack(hdr, ack);
739 msg_set_bcast_ack(hdr, bc_ack);
740
741 if (likely(skb_queue_len(transmq) < maxwin)) {
742 _skb = skb_clone(skb, GFP_ATOMIC);
743 if (!_skb)
744 return -ENOBUFS;
745 __skb_dequeue(list);
746 __skb_queue_tail(transmq, skb);
747 __skb_queue_tail(xmitq, _skb);
748 TIPC_SKB_CB(skb)->ackers = l->ackers;
749 l->rcv_unacked = 0;
750 seqno++;
751 continue;
752 }
753 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
754 kfree_skb(__skb_dequeue(list));
755 l->stats.sent_bundled++;
756 continue;
757 }
758 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
759 kfree_skb(__skb_dequeue(list));
760 __skb_queue_tail(backlogq, bskb);
761 l->backlog[msg_importance(buf_msg(bskb))].len++;
762 l->stats.sent_bundled++;
763 l->stats.sent_bundles++;
764 continue;
765 }
766 l->backlog[imp].len += skb_queue_len(list);
767 skb_queue_splice_tail_init(list, backlogq);
768 }
769 l->snd_nxt = seqno;
770 return 0;
771 }
772
773 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
774 {
775 struct sk_buff *skb, *_skb;
776 struct tipc_msg *hdr;
777 u16 seqno = l->snd_nxt;
778 u16 ack = l->rcv_nxt - 1;
779 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
780
781 while (skb_queue_len(&l->transmq) < l->window) {
782 skb = skb_peek(&l->backlogq);
783 if (!skb)
784 break;
785 _skb = skb_clone(skb, GFP_ATOMIC);
786 if (!_skb)
787 break;
788 __skb_dequeue(&l->backlogq);
789 hdr = buf_msg(skb);
790 l->backlog[msg_importance(hdr)].len--;
791 __skb_queue_tail(&l->transmq, skb);
792 __skb_queue_tail(xmitq, _skb);
793 TIPC_SKB_CB(skb)->ackers = l->ackers;
794 msg_set_seqno(hdr, seqno);
795 msg_set_ack(hdr, ack);
796 msg_set_bcast_ack(hdr, bc_ack);
797 l->rcv_unacked = 0;
798 seqno++;
799 }
800 l->snd_nxt = seqno;
801 }
802
803 static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
804 {
805 struct tipc_msg *hdr = buf_msg(skb);
806
807 pr_warn("Retransmission failure on link <%s>\n", l->name);
808 link_print(l, "Resetting link ");
809 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
810 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
811 pr_info("sqno %u, prev: %x, src: %x\n",
812 msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
813 }
814
815 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
816 struct sk_buff_head *xmitq)
817 {
818 struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
819 struct tipc_msg *hdr;
820 u16 ack = l->rcv_nxt - 1;
821 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
822
823 if (!skb)
824 return 0;
825
826 /* Detect repeated retransmit failures on same packet */
827 if (likely(l->last_retransm != buf_seqno(skb))) {
828 l->last_retransm = buf_seqno(skb);
829 l->stale_count = 1;
830 } else if (++l->stale_count > 100) {
831 link_retransmit_failure(l, skb);
832 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
833 }
834
835 /* Move forward to where retransmission should start */
836 skb_queue_walk(&l->transmq, skb) {
837 if (!less(buf_seqno(skb), from))
838 break;
839 }
840
841 skb_queue_walk_from(&l->transmq, skb) {
842 if (more(buf_seqno(skb), to))
843 break;
844 hdr = buf_msg(skb);
845 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
846 if (!_skb)
847 return 0;
848 hdr = buf_msg(_skb);
849 msg_set_ack(hdr, ack);
850 msg_set_bcast_ack(hdr, bc_ack);
851 _skb->priority = TC_PRIO_CONTROL;
852 __skb_queue_tail(xmitq, _skb);
853 l->stats.retransmitted++;
854 }
855 return 0;
856 }
857
858 /* tipc_data_input - deliver data and name distr msgs to upper layer
859 *
860 * Consumes buffer if message is of right type
861 * Node lock must be held
862 */
863 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
864 struct sk_buff_head *inputq)
865 {
866 switch (msg_user(buf_msg(skb))) {
867 case TIPC_LOW_IMPORTANCE:
868 case TIPC_MEDIUM_IMPORTANCE:
869 case TIPC_HIGH_IMPORTANCE:
870 case TIPC_CRITICAL_IMPORTANCE:
871 case CONN_MANAGER:
872 skb_queue_tail(inputq, skb);
873 return true;
874 case NAME_DISTRIBUTOR:
875 l->bc_rcvlink->state = LINK_ESTABLISHED;
876 skb_queue_tail(l->namedq, skb);
877 return true;
878 case MSG_BUNDLER:
879 case TUNNEL_PROTOCOL:
880 case MSG_FRAGMENTER:
881 case BCAST_PROTOCOL:
882 return false;
883 default:
884 pr_warn("Dropping received illegal msg type\n");
885 kfree_skb(skb);
886 return true;
887 };
888 }
889
890 /* tipc_link_input - process packet that has passed link protocol check
891 *
892 * Consumes buffer
893 */
894 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
895 struct sk_buff_head *inputq)
896 {
897 struct tipc_msg *hdr = buf_msg(skb);
898 struct sk_buff **reasm_skb = &l->reasm_buf;
899 struct sk_buff *iskb;
900 struct sk_buff_head tmpq;
901 int usr = msg_user(hdr);
902 int rc = 0;
903 int pos = 0;
904 int ipos = 0;
905
906 if (unlikely(usr == TUNNEL_PROTOCOL)) {
907 if (msg_type(hdr) == SYNCH_MSG) {
908 __skb_queue_purge(&l->deferdq);
909 goto drop;
910 }
911 if (!tipc_msg_extract(skb, &iskb, &ipos))
912 return rc;
913 kfree_skb(skb);
914 skb = iskb;
915 hdr = buf_msg(skb);
916 if (less(msg_seqno(hdr), l->drop_point))
917 goto drop;
918 if (tipc_data_input(l, skb, inputq))
919 return rc;
920 usr = msg_user(hdr);
921 reasm_skb = &l->failover_reasm_skb;
922 }
923
924 if (usr == MSG_BUNDLER) {
925 skb_queue_head_init(&tmpq);
926 l->stats.recv_bundles++;
927 l->stats.recv_bundled += msg_msgcnt(hdr);
928 while (tipc_msg_extract(skb, &iskb, &pos))
929 tipc_data_input(l, iskb, &tmpq);
930 tipc_skb_queue_splice_tail(&tmpq, inputq);
931 return 0;
932 } else if (usr == MSG_FRAGMENTER) {
933 l->stats.recv_fragments++;
934 if (tipc_buf_append(reasm_skb, &skb)) {
935 l->stats.recv_fragmented++;
936 tipc_data_input(l, skb, inputq);
937 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
938 pr_warn_ratelimited("Unable to build fragment list\n");
939 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
940 }
941 return 0;
942 } else if (usr == BCAST_PROTOCOL) {
943 tipc_bcast_lock(l->net);
944 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
945 tipc_bcast_unlock(l->net);
946 }
947 drop:
948 kfree_skb(skb);
949 return 0;
950 }
951
952 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
953 {
954 bool released = false;
955 struct sk_buff *skb, *tmp;
956
957 skb_queue_walk_safe(&l->transmq, skb, tmp) {
958 if (more(buf_seqno(skb), acked))
959 break;
960 __skb_unlink(skb, &l->transmq);
961 kfree_skb(skb);
962 released = true;
963 }
964 return released;
965 }
966
967 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
968 *
969 * Note that sending of broadcast ack is coordinated among nodes, to reduce
970 * risk of ack storms towards the sender
971 */
972 int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
973 {
974 if (!l)
975 return 0;
976
977 /* Broadcast ACK must be sent via a unicast link => defer to caller */
978 if (link_is_bc_rcvlink(l)) {
979 if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf)
980 return 0;
981 l->rcv_unacked = 0;
982 return TIPC_LINK_SND_BC_ACK;
983 }
984
985 /* Unicast ACK */
986 l->rcv_unacked = 0;
987 l->stats.sent_acks++;
988 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
989 return 0;
990 }
991
992 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
993 */
994 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
995 {
996 int mtyp = RESET_MSG;
997
998 if (l->state == LINK_ESTABLISHING)
999 mtyp = ACTIVATE_MSG;
1000
1001 tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1002 }
1003
1004 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1005 */
1006 static void tipc_link_build_nack_msg(struct tipc_link *l,
1007 struct sk_buff_head *xmitq)
1008 {
1009 u32 def_cnt = ++l->stats.deferred_recv;
1010
1011 if (link_is_bc_rcvlink(l))
1012 return;
1013
1014 if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1015 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1016 }
1017
1018 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1019 * @l: the link that should handle the message
1020 * @skb: TIPC packet
1021 * @xmitq: queue to place packets to be sent after this call
1022 */
1023 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1024 struct sk_buff_head *xmitq)
1025 {
1026 struct sk_buff_head *defq = &l->deferdq;
1027 struct tipc_msg *hdr;
1028 u16 seqno, rcv_nxt, win_lim;
1029 int rc = 0;
1030
1031 do {
1032 hdr = buf_msg(skb);
1033 seqno = msg_seqno(hdr);
1034 rcv_nxt = l->rcv_nxt;
1035 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1036
1037 /* Verify and update link state */
1038 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1039 return tipc_link_proto_rcv(l, skb, xmitq);
1040
1041 if (unlikely(!link_is_up(l))) {
1042 if (l->state == LINK_ESTABLISHING)
1043 rc = TIPC_LINK_UP_EVT;
1044 goto drop;
1045 }
1046
1047 /* Don't send probe at next timeout expiration */
1048 l->silent_intv_cnt = 0;
1049
1050 /* Drop if outside receive window */
1051 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1052 l->stats.duplicates++;
1053 goto drop;
1054 }
1055
1056 /* Forward queues and wake up waiting users */
1057 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1058 tipc_link_advance_backlog(l, xmitq);
1059 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1060 link_prepare_wakeup(l);
1061 }
1062
1063 /* Defer delivery if sequence gap */
1064 if (unlikely(seqno != rcv_nxt)) {
1065 __tipc_skb_queue_sorted(defq, seqno, skb);
1066 tipc_link_build_nack_msg(l, xmitq);
1067 break;
1068 }
1069
1070 /* Deliver packet */
1071 l->rcv_nxt++;
1072 l->stats.recv_info++;
1073 if (!tipc_data_input(l, skb, l->inputq))
1074 rc |= tipc_link_input(l, skb, l->inputq);
1075 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1076 rc |= tipc_link_build_ack_msg(l, xmitq);
1077 if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
1078 break;
1079 } while ((skb = __skb_dequeue(defq)));
1080
1081 return rc;
1082 drop:
1083 kfree_skb(skb);
1084 return rc;
1085 }
1086
1087 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1088 u16 rcvgap, int tolerance, int priority,
1089 struct sk_buff_head *xmitq)
1090 {
1091 struct sk_buff *skb = NULL;
1092 struct tipc_msg *hdr = l->pmsg;
1093 bool node_up = link_is_up(l->bc_rcvlink);
1094
1095 /* Don't send protocol message during reset or link failover */
1096 if (tipc_link_is_blocked(l))
1097 return;
1098
1099 msg_set_type(hdr, mtyp);
1100 msg_set_net_plane(hdr, l->net_plane);
1101 msg_set_next_sent(hdr, l->snd_nxt);
1102 msg_set_ack(hdr, l->rcv_nxt - 1);
1103 msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
1104 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1105 msg_set_link_tolerance(hdr, tolerance);
1106 msg_set_linkprio(hdr, priority);
1107 msg_set_redundant_link(hdr, node_up);
1108 msg_set_seq_gap(hdr, 0);
1109
1110 /* Compatibility: created msg must not be in sequence with pkt flow */
1111 msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1112
1113 if (mtyp == STATE_MSG) {
1114 if (!tipc_link_is_up(l))
1115 return;
1116
1117 /* Override rcvgap if there are packets in deferred queue */
1118 if (!skb_queue_empty(&l->deferdq))
1119 rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
1120 if (rcvgap) {
1121 msg_set_seq_gap(hdr, rcvgap);
1122 l->stats.sent_nacks++;
1123 }
1124 msg_set_probe(hdr, probe);
1125 if (probe)
1126 l->stats.sent_probes++;
1127 l->stats.sent_states++;
1128 l->rcv_unacked = 0;
1129 } else {
1130 /* RESET_MSG or ACTIVATE_MSG */
1131 msg_set_max_pkt(hdr, l->advertised_mtu);
1132 msg_set_ack(hdr, l->rcv_nxt - 1);
1133 msg_set_next_sent(hdr, 1);
1134 }
1135 skb = tipc_buf_acquire(msg_size(hdr));
1136 if (!skb)
1137 return;
1138 skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1139 skb->priority = TC_PRIO_CONTROL;
1140 __skb_queue_tail(xmitq, skb);
1141 }
1142
1143 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1144 * with contents of the link's transmit and backlog queues.
1145 */
1146 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1147 int mtyp, struct sk_buff_head *xmitq)
1148 {
1149 struct sk_buff *skb, *tnlskb;
1150 struct tipc_msg *hdr, tnlhdr;
1151 struct sk_buff_head *queue = &l->transmq;
1152 struct sk_buff_head tmpxq, tnlq;
1153 u16 pktlen, pktcnt, seqno = l->snd_nxt;
1154
1155 if (!tnl)
1156 return;
1157
1158 skb_queue_head_init(&tnlq);
1159 skb_queue_head_init(&tmpxq);
1160
1161 /* At least one packet required for safe algorithm => add dummy */
1162 skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1163 BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
1164 0, 0, TIPC_ERR_NO_PORT);
1165 if (!skb) {
1166 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1167 return;
1168 }
1169 skb_queue_tail(&tnlq, skb);
1170 tipc_link_xmit(l, &tnlq, &tmpxq);
1171 __skb_queue_purge(&tmpxq);
1172
1173 /* Initialize reusable tunnel packet header */
1174 tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
1175 mtyp, INT_H_SIZE, l->addr);
1176 pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1177 msg_set_msgcnt(&tnlhdr, pktcnt);
1178 msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1179 tnl:
1180 /* Wrap each packet into a tunnel packet */
1181 skb_queue_walk(queue, skb) {
1182 hdr = buf_msg(skb);
1183 if (queue == &l->backlogq)
1184 msg_set_seqno(hdr, seqno++);
1185 pktlen = msg_size(hdr);
1186 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1187 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1188 if (!tnlskb) {
1189 pr_warn("%sunable to send packet\n", link_co_err);
1190 return;
1191 }
1192 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1193 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1194 __skb_queue_tail(&tnlq, tnlskb);
1195 }
1196 if (queue != &l->backlogq) {
1197 queue = &l->backlogq;
1198 goto tnl;
1199 }
1200
1201 tipc_link_xmit(tnl, &tnlq, xmitq);
1202
1203 if (mtyp == FAILOVER_MSG) {
1204 tnl->drop_point = l->rcv_nxt;
1205 tnl->failover_reasm_skb = l->reasm_buf;
1206 l->reasm_buf = NULL;
1207 }
1208 }
1209
1210 /* tipc_link_proto_rcv(): receive link level protocol message :
1211 * Note that network plane id propagates through the network, and may
1212 * change at any time. The node with lowest numerical id determines
1213 * network plane
1214 */
1215 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1216 struct sk_buff_head *xmitq)
1217 {
1218 struct tipc_msg *hdr = buf_msg(skb);
1219 u16 rcvgap = 0;
1220 u16 ack = msg_ack(hdr);
1221 u16 gap = msg_seq_gap(hdr);
1222 u16 peers_snd_nxt = msg_next_sent(hdr);
1223 u16 peers_tol = msg_link_tolerance(hdr);
1224 u16 peers_prio = msg_linkprio(hdr);
1225 u16 rcv_nxt = l->rcv_nxt;
1226 int mtyp = msg_type(hdr);
1227 char *if_name;
1228 int rc = 0;
1229
1230 if (tipc_link_is_blocked(l) || !xmitq)
1231 goto exit;
1232
1233 if (link_own_addr(l) > msg_prevnode(hdr))
1234 l->net_plane = msg_net_plane(hdr);
1235
1236 switch (mtyp) {
1237 case RESET_MSG:
1238
1239 /* Ignore duplicate RESET with old session number */
1240 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1241 (l->peer_session != WILDCARD_SESSION))
1242 break;
1243 /* fall thru' */
1244
1245 case ACTIVATE_MSG:
1246 skb_linearize(skb);
1247 hdr = buf_msg(skb);
1248
1249 /* Complete own link name with peer's interface name */
1250 if_name = strrchr(l->name, ':') + 1;
1251 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1252 break;
1253 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1254 break;
1255 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1256
1257 /* Update own tolerance if peer indicates a non-zero value */
1258 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1259 l->tolerance = peers_tol;
1260
1261 /* Update own priority if peer's priority is higher */
1262 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1263 l->priority = peers_prio;
1264
1265 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1266 if ((mtyp == RESET_MSG) || !link_is_up(l))
1267 rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1268
1269 /* ACTIVATE_MSG takes up link if it was already locally reset */
1270 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1271 rc = TIPC_LINK_UP_EVT;
1272
1273 l->peer_session = msg_session(hdr);
1274 l->peer_bearer_id = msg_bearer_id(hdr);
1275 if (l->mtu > msg_max_pkt(hdr))
1276 l->mtu = msg_max_pkt(hdr);
1277 break;
1278
1279 case STATE_MSG:
1280
1281 /* Update own tolerance if peer indicates a non-zero value */
1282 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1283 l->tolerance = peers_tol;
1284
1285 l->silent_intv_cnt = 0;
1286 l->stats.recv_states++;
1287 if (msg_probe(hdr))
1288 l->stats.recv_probes++;
1289
1290 if (!link_is_up(l)) {
1291 if (l->state == LINK_ESTABLISHING)
1292 rc = TIPC_LINK_UP_EVT;
1293 break;
1294 }
1295
1296 /* Send NACK if peer has sent pkts we haven't received yet */
1297 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1298 rcvgap = peers_snd_nxt - l->rcv_nxt;
1299 if (rcvgap || (msg_probe(hdr)))
1300 tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1301 0, 0, xmitq);
1302 tipc_link_release_pkts(l, ack);
1303
1304 /* If NACK, retransmit will now start at right position */
1305 if (gap) {
1306 rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1307 l->stats.recv_nacks++;
1308 }
1309
1310 tipc_link_advance_backlog(l, xmitq);
1311 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1312 link_prepare_wakeup(l);
1313 }
1314 exit:
1315 kfree_skb(skb);
1316 return rc;
1317 }
1318
1319 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1320 */
1321 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1322 u16 peers_snd_nxt,
1323 struct sk_buff_head *xmitq)
1324 {
1325 struct sk_buff *skb;
1326 struct tipc_msg *hdr;
1327 struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1328 u16 ack = l->rcv_nxt - 1;
1329 u16 gap_to = peers_snd_nxt - 1;
1330
1331 skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1332 0, l->addr, link_own_addr(l), 0, 0, 0);
1333 if (!skb)
1334 return false;
1335 hdr = buf_msg(skb);
1336 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1337 msg_set_bcast_ack(hdr, ack);
1338 msg_set_bcgap_after(hdr, ack);
1339 if (dfrd_skb)
1340 gap_to = buf_seqno(dfrd_skb) - 1;
1341 msg_set_bcgap_to(hdr, gap_to);
1342 msg_set_non_seq(hdr, bcast);
1343 __skb_queue_tail(xmitq, skb);
1344 return true;
1345 }
1346
1347 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1348 *
1349 * Give a newly added peer node the sequence number where it should
1350 * start receiving and acking broadcast packets.
1351 */
1352 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1353 struct sk_buff_head *xmitq)
1354 {
1355 struct sk_buff_head list;
1356
1357 __skb_queue_head_init(&list);
1358 if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1359 return;
1360 tipc_link_xmit(l, &list, xmitq);
1361 }
1362
1363 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1364 */
1365 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1366 {
1367 int mtyp = msg_type(hdr);
1368 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1369
1370 if (link_is_up(l))
1371 return;
1372
1373 if (msg_user(hdr) == BCAST_PROTOCOL) {
1374 l->rcv_nxt = peers_snd_nxt;
1375 l->state = LINK_ESTABLISHED;
1376 return;
1377 }
1378
1379 if (l->peer_caps & TIPC_BCAST_SYNCH)
1380 return;
1381
1382 if (msg_peer_node_is_up(hdr))
1383 return;
1384
1385 /* Compatibility: accept older, less safe initial synch data */
1386 if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1387 l->rcv_nxt = peers_snd_nxt;
1388 }
1389
1390 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1391 */
1392 void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1393 struct sk_buff_head *xmitq)
1394 {
1395 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1396
1397 if (!link_is_up(l))
1398 return;
1399
1400 if (!msg_peer_node_is_up(hdr))
1401 return;
1402
1403 l->bc_peer_is_up = true;
1404
1405 /* Ignore if peers_snd_nxt goes beyond receive window */
1406 if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1407 return;
1408
1409 if (!more(peers_snd_nxt, l->rcv_nxt)) {
1410 l->nack_state = BC_NACK_SND_CONDITIONAL;
1411 return;
1412 }
1413
1414 /* Don't NACK if one was recently sent or peeked */
1415 if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1416 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1417 return;
1418 }
1419
1420 /* Conditionally delay NACK sending until next synch rcv */
1421 if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1422 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1423 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1424 return;
1425 }
1426
1427 /* Send NACK now but suppress next one */
1428 tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1429 l->nack_state = BC_NACK_SND_SUPPRESS;
1430 }
1431
1432 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1433 struct sk_buff_head *xmitq)
1434 {
1435 struct sk_buff *skb, *tmp;
1436 struct tipc_link *snd_l = l->bc_sndlink;
1437
1438 if (!link_is_up(l) || !l->bc_peer_is_up)
1439 return;
1440
1441 if (!more(acked, l->acked))
1442 return;
1443
1444 /* Skip over packets peer has already acked */
1445 skb_queue_walk(&snd_l->transmq, skb) {
1446 if (more(buf_seqno(skb), l->acked))
1447 break;
1448 }
1449
1450 /* Update/release the packets peer is acking now */
1451 skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1452 if (more(buf_seqno(skb), acked))
1453 break;
1454 if (!--TIPC_SKB_CB(skb)->ackers) {
1455 __skb_unlink(skb, &snd_l->transmq);
1456 kfree_skb(skb);
1457 }
1458 }
1459 l->acked = acked;
1460 tipc_link_advance_backlog(snd_l, xmitq);
1461 if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1462 link_prepare_wakeup(snd_l);
1463 }
1464
1465 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
1466 */
1467 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1468 struct sk_buff_head *xmitq)
1469 {
1470 struct tipc_msg *hdr = buf_msg(skb);
1471 u32 dnode = msg_destnode(hdr);
1472 int mtyp = msg_type(hdr);
1473 u16 acked = msg_bcast_ack(hdr);
1474 u16 from = acked + 1;
1475 u16 to = msg_bcgap_to(hdr);
1476 u16 peers_snd_nxt = to + 1;
1477 int rc = 0;
1478
1479 kfree_skb(skb);
1480
1481 if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1482 return 0;
1483
1484 if (mtyp != STATE_MSG)
1485 return 0;
1486
1487 if (dnode == link_own_addr(l)) {
1488 tipc_link_bc_ack_rcv(l, acked, xmitq);
1489 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1490 l->stats.recv_nacks++;
1491 return rc;
1492 }
1493
1494 /* Msg for other node => suppress own NACK at next sync if applicable */
1495 if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1496 l->nack_state = BC_NACK_SND_SUPPRESS;
1497
1498 return 0;
1499 }
1500
1501 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1502 {
1503 int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1504
1505 l->window = win;
1506 l->backlog[TIPC_LOW_IMPORTANCE].limit = win / 2;
1507 l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = win;
1508 l->backlog[TIPC_HIGH_IMPORTANCE].limit = win / 2 * 3;
1509 l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1510 l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
1511 }
1512
1513 /* tipc_link_find_owner - locate owner node of link by link's name
1514 * @net: the applicable net namespace
1515 * @name: pointer to link name string
1516 * @bearer_id: pointer to index in 'node->links' array where the link was found.
1517 *
1518 * Returns pointer to node owning the link, or 0 if no matching link is found.
1519 */
1520 static struct tipc_node *tipc_link_find_owner(struct net *net,
1521 const char *link_name,
1522 unsigned int *bearer_id)
1523 {
1524 struct tipc_net *tn = net_generic(net, tipc_net_id);
1525 struct tipc_link *l_ptr;
1526 struct tipc_node *n_ptr;
1527 struct tipc_node *found_node = NULL;
1528 int i;
1529
1530 *bearer_id = 0;
1531 rcu_read_lock();
1532 list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1533 tipc_node_lock(n_ptr);
1534 for (i = 0; i < MAX_BEARERS; i++) {
1535 l_ptr = n_ptr->links[i].link;
1536 if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1537 *bearer_id = i;
1538 found_node = n_ptr;
1539 break;
1540 }
1541 }
1542 tipc_node_unlock(n_ptr);
1543 if (found_node)
1544 break;
1545 }
1546 rcu_read_unlock();
1547
1548 return found_node;
1549 }
1550
1551 /**
1552 * link_reset_statistics - reset link statistics
1553 * @l_ptr: pointer to link
1554 */
1555 static void link_reset_statistics(struct tipc_link *l_ptr)
1556 {
1557 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1558 l_ptr->stats.sent_info = l_ptr->snd_nxt;
1559 l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1560 }
1561
1562 static void link_print(struct tipc_link *l, const char *str)
1563 {
1564 struct sk_buff *hskb = skb_peek(&l->transmq);
1565 u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1566 u16 tail = l->snd_nxt - 1;
1567
1568 pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1569 pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1570 skb_queue_len(&l->transmq), head, tail,
1571 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1572 }
1573
1574 /* Parse and validate nested (link) properties valid for media, bearer and link
1575 */
1576 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1577 {
1578 int err;
1579
1580 err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1581 tipc_nl_prop_policy);
1582 if (err)
1583 return err;
1584
1585 if (props[TIPC_NLA_PROP_PRIO]) {
1586 u32 prio;
1587
1588 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1589 if (prio > TIPC_MAX_LINK_PRI)
1590 return -EINVAL;
1591 }
1592
1593 if (props[TIPC_NLA_PROP_TOL]) {
1594 u32 tol;
1595
1596 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1597 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1598 return -EINVAL;
1599 }
1600
1601 if (props[TIPC_NLA_PROP_WIN]) {
1602 u32 win;
1603
1604 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1605 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1606 return -EINVAL;
1607 }
1608
1609 return 0;
1610 }
1611
1612 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1613 {
1614 int err;
1615 int res = 0;
1616 int bearer_id;
1617 char *name;
1618 struct tipc_link *link;
1619 struct tipc_node *node;
1620 struct sk_buff_head xmitq;
1621 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1622 struct net *net = sock_net(skb->sk);
1623
1624 __skb_queue_head_init(&xmitq);
1625
1626 if (!info->attrs[TIPC_NLA_LINK])
1627 return -EINVAL;
1628
1629 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1630 info->attrs[TIPC_NLA_LINK],
1631 tipc_nl_link_policy);
1632 if (err)
1633 return err;
1634
1635 if (!attrs[TIPC_NLA_LINK_NAME])
1636 return -EINVAL;
1637
1638 name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1639
1640 if (strcmp(name, tipc_bclink_name) == 0)
1641 return tipc_nl_bc_link_set(net, attrs);
1642
1643 node = tipc_link_find_owner(net, name, &bearer_id);
1644 if (!node)
1645 return -EINVAL;
1646
1647 tipc_node_lock(node);
1648
1649 link = node->links[bearer_id].link;
1650 if (!link) {
1651 res = -EINVAL;
1652 goto out;
1653 }
1654
1655 if (attrs[TIPC_NLA_LINK_PROP]) {
1656 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1657
1658 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1659 props);
1660 if (err) {
1661 res = err;
1662 goto out;
1663 }
1664
1665 if (props[TIPC_NLA_PROP_TOL]) {
1666 u32 tol;
1667
1668 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1669 link->tolerance = tol;
1670 tipc_link_build_proto_msg(link, STATE_MSG, 0, 0, tol, 0, &xmitq);
1671 }
1672 if (props[TIPC_NLA_PROP_PRIO]) {
1673 u32 prio;
1674
1675 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1676 link->priority = prio;
1677 tipc_link_build_proto_msg(link, STATE_MSG, 0, 0, 0, prio, &xmitq);
1678 }
1679 if (props[TIPC_NLA_PROP_WIN]) {
1680 u32 win;
1681
1682 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1683 tipc_link_set_queue_limits(link, win);
1684 }
1685 }
1686
1687 out:
1688 tipc_node_unlock(node);
1689 tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
1690 return res;
1691 }
1692
1693 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1694 {
1695 int i;
1696 struct nlattr *stats;
1697
1698 struct nla_map {
1699 u32 key;
1700 u32 val;
1701 };
1702
1703 struct nla_map map[] = {
1704 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1705 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1706 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1707 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1708 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1709 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1710 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1711 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1712 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1713 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1714 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1715 s->msg_length_counts : 1},
1716 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1717 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1718 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1719 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1720 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1721 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1722 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1723 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1724 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1725 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1726 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1727 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1728 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1729 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1730 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1731 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1732 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1733 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1734 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1735 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1736 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1737 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1738 (s->accu_queue_sz / s->queue_sz_counts) : 0}
1739 };
1740
1741 stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1742 if (!stats)
1743 return -EMSGSIZE;
1744
1745 for (i = 0; i < ARRAY_SIZE(map); i++)
1746 if (nla_put_u32(skb, map[i].key, map[i].val))
1747 goto msg_full;
1748
1749 nla_nest_end(skb, stats);
1750
1751 return 0;
1752 msg_full:
1753 nla_nest_cancel(skb, stats);
1754
1755 return -EMSGSIZE;
1756 }
1757
1758 /* Caller should hold appropriate locks to protect the link */
1759 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1760 struct tipc_link *link, int nlflags)
1761 {
1762 int err;
1763 void *hdr;
1764 struct nlattr *attrs;
1765 struct nlattr *prop;
1766 struct tipc_net *tn = net_generic(net, tipc_net_id);
1767
1768 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1769 nlflags, TIPC_NL_LINK_GET);
1770 if (!hdr)
1771 return -EMSGSIZE;
1772
1773 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1774 if (!attrs)
1775 goto msg_full;
1776
1777 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1778 goto attr_msg_full;
1779 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1780 tipc_cluster_mask(tn->own_addr)))
1781 goto attr_msg_full;
1782 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1783 goto attr_msg_full;
1784 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1785 goto attr_msg_full;
1786 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1787 goto attr_msg_full;
1788
1789 if (tipc_link_is_up(link))
1790 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1791 goto attr_msg_full;
1792 if (link->active)
1793 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1794 goto attr_msg_full;
1795
1796 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1797 if (!prop)
1798 goto attr_msg_full;
1799 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1800 goto prop_msg_full;
1801 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1802 goto prop_msg_full;
1803 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1804 link->window))
1805 goto prop_msg_full;
1806 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1807 goto prop_msg_full;
1808 nla_nest_end(msg->skb, prop);
1809
1810 err = __tipc_nl_add_stats(msg->skb, &link->stats);
1811 if (err)
1812 goto attr_msg_full;
1813
1814 nla_nest_end(msg->skb, attrs);
1815 genlmsg_end(msg->skb, hdr);
1816
1817 return 0;
1818
1819 prop_msg_full:
1820 nla_nest_cancel(msg->skb, prop);
1821 attr_msg_full:
1822 nla_nest_cancel(msg->skb, attrs);
1823 msg_full:
1824 genlmsg_cancel(msg->skb, hdr);
1825
1826 return -EMSGSIZE;
1827 }
1828
1829 /* Caller should hold node lock */
1830 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1831 struct tipc_node *node, u32 *prev_link)
1832 {
1833 u32 i;
1834 int err;
1835
1836 for (i = *prev_link; i < MAX_BEARERS; i++) {
1837 *prev_link = i;
1838
1839 if (!node->links[i].link)
1840 continue;
1841
1842 err = __tipc_nl_add_link(net, msg,
1843 node->links[i].link, NLM_F_MULTI);
1844 if (err)
1845 return err;
1846 }
1847 *prev_link = 0;
1848
1849 return 0;
1850 }
1851
1852 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
1853 {
1854 struct net *net = sock_net(skb->sk);
1855 struct tipc_net *tn = net_generic(net, tipc_net_id);
1856 struct tipc_node *node;
1857 struct tipc_nl_msg msg;
1858 u32 prev_node = cb->args[0];
1859 u32 prev_link = cb->args[1];
1860 int done = cb->args[2];
1861 int err;
1862
1863 if (done)
1864 return 0;
1865
1866 msg.skb = skb;
1867 msg.portid = NETLINK_CB(cb->skb).portid;
1868 msg.seq = cb->nlh->nlmsg_seq;
1869
1870 rcu_read_lock();
1871 if (prev_node) {
1872 node = tipc_node_find(net, prev_node);
1873 if (!node) {
1874 /* We never set seq or call nl_dump_check_consistent()
1875 * this means that setting prev_seq here will cause the
1876 * consistence check to fail in the netlink callback
1877 * handler. Resulting in the last NLMSG_DONE message
1878 * having the NLM_F_DUMP_INTR flag set.
1879 */
1880 cb->prev_seq = 1;
1881 goto out;
1882 }
1883 tipc_node_put(node);
1884
1885 list_for_each_entry_continue_rcu(node, &tn->node_list,
1886 list) {
1887 tipc_node_lock(node);
1888 err = __tipc_nl_add_node_links(net, &msg, node,
1889 &prev_link);
1890 tipc_node_unlock(node);
1891 if (err)
1892 goto out;
1893
1894 prev_node = node->addr;
1895 }
1896 } else {
1897 err = tipc_nl_add_bc_link(net, &msg);
1898 if (err)
1899 goto out;
1900
1901 list_for_each_entry_rcu(node, &tn->node_list, list) {
1902 tipc_node_lock(node);
1903 err = __tipc_nl_add_node_links(net, &msg, node,
1904 &prev_link);
1905 tipc_node_unlock(node);
1906 if (err)
1907 goto out;
1908
1909 prev_node = node->addr;
1910 }
1911 }
1912 done = 1;
1913 out:
1914 rcu_read_unlock();
1915
1916 cb->args[0] = prev_node;
1917 cb->args[1] = prev_link;
1918 cb->args[2] = done;
1919
1920 return skb->len;
1921 }
1922
1923 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
1924 {
1925 struct net *net = genl_info_net(info);
1926 struct tipc_nl_msg msg;
1927 char *name;
1928 int err;
1929
1930 msg.portid = info->snd_portid;
1931 msg.seq = info->snd_seq;
1932
1933 if (!info->attrs[TIPC_NLA_LINK_NAME])
1934 return -EINVAL;
1935 name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
1936
1937 msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1938 if (!msg.skb)
1939 return -ENOMEM;
1940
1941 if (strcmp(name, tipc_bclink_name) == 0) {
1942 err = tipc_nl_add_bc_link(net, &msg);
1943 if (err) {
1944 nlmsg_free(msg.skb);
1945 return err;
1946 }
1947 } else {
1948 int bearer_id;
1949 struct tipc_node *node;
1950 struct tipc_link *link;
1951
1952 node = tipc_link_find_owner(net, name, &bearer_id);
1953 if (!node)
1954 return -EINVAL;
1955
1956 tipc_node_lock(node);
1957 link = node->links[bearer_id].link;
1958 if (!link) {
1959 tipc_node_unlock(node);
1960 nlmsg_free(msg.skb);
1961 return -EINVAL;
1962 }
1963
1964 err = __tipc_nl_add_link(net, &msg, link, 0);
1965 tipc_node_unlock(node);
1966 if (err) {
1967 nlmsg_free(msg.skb);
1968 return err;
1969 }
1970 }
1971
1972 return genlmsg_reply(msg.skb, info);
1973 }
1974
1975 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
1976 {
1977 int err;
1978 char *link_name;
1979 unsigned int bearer_id;
1980 struct tipc_link *link;
1981 struct tipc_node *node;
1982 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1983 struct net *net = sock_net(skb->sk);
1984
1985 if (!info->attrs[TIPC_NLA_LINK])
1986 return -EINVAL;
1987
1988 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1989 info->attrs[TIPC_NLA_LINK],
1990 tipc_nl_link_policy);
1991 if (err)
1992 return err;
1993
1994 if (!attrs[TIPC_NLA_LINK_NAME])
1995 return -EINVAL;
1996
1997 link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1998
1999 if (strcmp(link_name, tipc_bclink_name) == 0) {
2000 err = tipc_bclink_reset_stats(net);
2001 if (err)
2002 return err;
2003 return 0;
2004 }
2005
2006 node = tipc_link_find_owner(net, link_name, &bearer_id);
2007 if (!node)
2008 return -EINVAL;
2009
2010 tipc_node_lock(node);
2011
2012 link = node->links[bearer_id].link;
2013 if (!link) {
2014 tipc_node_unlock(node);
2015 return -EINVAL;
2016 }
2017
2018 link_reset_statistics(link);
2019
2020 tipc_node_unlock(node);
2021
2022 return 0;
2023 }
2024
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