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Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[mirror_ubuntu-zesty-kernel.git] / net / tipc / link.c
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 tipc_link_build_bc_init_msg(uc_l, xmitq);
195 }
196
197 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
198 struct tipc_link *rcv_l,
199 struct sk_buff_head *xmitq)
200 {
201 u16 ack = snd_l->snd_nxt - 1;
202
203 snd_l->ackers--;
204 tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
205 tipc_link_reset(rcv_l);
206 rcv_l->state = LINK_RESET;
207 if (!snd_l->ackers) {
208 tipc_link_reset(snd_l);
209 __skb_queue_purge(xmitq);
210 }
211 }
212
213 int tipc_link_bc_peers(struct tipc_link *l)
214 {
215 return l->ackers;
216 }
217
218 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
219 {
220 l->mtu = mtu;
221 }
222
223 int tipc_link_mtu(struct tipc_link *l)
224 {
225 return l->mtu;
226 }
227
228 static u32 link_own_addr(struct tipc_link *l)
229 {
230 return msg_prevnode(l->pmsg);
231 }
232
233 /**
234 * tipc_link_create - create a new link
235 * @n: pointer to associated node
236 * @if_name: associated interface name
237 * @bearer_id: id (index) of associated bearer
238 * @tolerance: link tolerance to be used by link
239 * @net_plane: network plane (A,B,c..) this link belongs to
240 * @mtu: mtu to be advertised by link
241 * @priority: priority to be used by link
242 * @window: send window to be used by link
243 * @session: session to be used by link
244 * @ownnode: identity of own node
245 * @peer: node id of peer node
246 * @peer_caps: bitmap describing peer node capabilities
247 * @bc_sndlink: the namespace global link used for broadcast sending
248 * @bc_rcvlink: the peer specific link used for broadcast reception
249 * @inputq: queue to put messages ready for delivery
250 * @namedq: queue to put binding table update messages ready for delivery
251 * @link: return value, pointer to put the created link
252 *
253 * Returns true if link was created, otherwise false
254 */
255 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
256 int tolerance, char net_plane, u32 mtu, int priority,
257 int window, u32 session, u32 ownnode, u32 peer,
258 u16 peer_caps,
259 struct tipc_link *bc_sndlink,
260 struct tipc_link *bc_rcvlink,
261 struct sk_buff_head *inputq,
262 struct sk_buff_head *namedq,
263 struct tipc_link **link)
264 {
265 struct tipc_link *l;
266 struct tipc_msg *hdr;
267
268 l = kzalloc(sizeof(*l), GFP_ATOMIC);
269 if (!l)
270 return false;
271 *link = l;
272 l->pmsg = (struct tipc_msg *)&l->proto_msg;
273 hdr = l->pmsg;
274 tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
275 msg_set_size(hdr, sizeof(l->proto_msg));
276 msg_set_session(hdr, session);
277 msg_set_bearer_id(hdr, l->bearer_id);
278
279 /* Note: peer i/f name is completed by reset/activate message */
280 sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
281 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
282 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
283 strcpy((char *)msg_data(hdr), if_name);
284
285 l->addr = peer;
286 l->peer_caps = peer_caps;
287 l->net = net;
288 l->peer_session = WILDCARD_SESSION;
289 l->bearer_id = bearer_id;
290 l->tolerance = tolerance;
291 l->net_plane = net_plane;
292 l->advertised_mtu = mtu;
293 l->mtu = mtu;
294 l->priority = priority;
295 tipc_link_set_queue_limits(l, window);
296 l->ackers = 1;
297 l->bc_sndlink = bc_sndlink;
298 l->bc_rcvlink = bc_rcvlink;
299 l->inputq = inputq;
300 l->namedq = namedq;
301 l->state = LINK_RESETTING;
302 __skb_queue_head_init(&l->transmq);
303 __skb_queue_head_init(&l->backlogq);
304 __skb_queue_head_init(&l->deferdq);
305 skb_queue_head_init(&l->wakeupq);
306 skb_queue_head_init(l->inputq);
307 return true;
308 }
309
310 /**
311 * tipc_link_bc_create - create new link to be used for broadcast
312 * @n: pointer to associated node
313 * @mtu: mtu to be used
314 * @window: send window to be used
315 * @inputq: queue to put messages ready for delivery
316 * @namedq: queue to put binding table update messages ready for delivery
317 * @link: return value, pointer to put the created link
318 *
319 * Returns true if link was created, otherwise false
320 */
321 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
322 int mtu, int window, u16 peer_caps,
323 struct sk_buff_head *inputq,
324 struct sk_buff_head *namedq,
325 struct tipc_link *bc_sndlink,
326 struct tipc_link **link)
327 {
328 struct tipc_link *l;
329
330 if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
331 0, ownnode, peer, peer_caps, bc_sndlink,
332 NULL, inputq, namedq, link))
333 return false;
334
335 l = *link;
336 strcpy(l->name, tipc_bclink_name);
337 tipc_link_reset(l);
338 l->state = LINK_RESET;
339 l->ackers = 0;
340 l->bc_rcvlink = l;
341
342 /* Broadcast send link is always up */
343 if (link_is_bc_sndlink(l))
344 l->state = LINK_ESTABLISHED;
345
346 return true;
347 }
348
349 /**
350 * tipc_link_fsm_evt - link finite state machine
351 * @l: pointer to link
352 * @evt: state machine event to be processed
353 */
354 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
355 {
356 int rc = 0;
357
358 switch (l->state) {
359 case LINK_RESETTING:
360 switch (evt) {
361 case LINK_PEER_RESET_EVT:
362 l->state = LINK_PEER_RESET;
363 break;
364 case LINK_RESET_EVT:
365 l->state = LINK_RESET;
366 break;
367 case LINK_FAILURE_EVT:
368 case LINK_FAILOVER_BEGIN_EVT:
369 case LINK_ESTABLISH_EVT:
370 case LINK_FAILOVER_END_EVT:
371 case LINK_SYNCH_BEGIN_EVT:
372 case LINK_SYNCH_END_EVT:
373 default:
374 goto illegal_evt;
375 }
376 break;
377 case LINK_RESET:
378 switch (evt) {
379 case LINK_PEER_RESET_EVT:
380 l->state = LINK_ESTABLISHING;
381 break;
382 case LINK_FAILOVER_BEGIN_EVT:
383 l->state = LINK_FAILINGOVER;
384 case LINK_FAILURE_EVT:
385 case LINK_RESET_EVT:
386 case LINK_ESTABLISH_EVT:
387 case LINK_FAILOVER_END_EVT:
388 break;
389 case LINK_SYNCH_BEGIN_EVT:
390 case LINK_SYNCH_END_EVT:
391 default:
392 goto illegal_evt;
393 }
394 break;
395 case LINK_PEER_RESET:
396 switch (evt) {
397 case LINK_RESET_EVT:
398 l->state = LINK_ESTABLISHING;
399 break;
400 case LINK_PEER_RESET_EVT:
401 case LINK_ESTABLISH_EVT:
402 case LINK_FAILURE_EVT:
403 break;
404 case LINK_SYNCH_BEGIN_EVT:
405 case LINK_SYNCH_END_EVT:
406 case LINK_FAILOVER_BEGIN_EVT:
407 case LINK_FAILOVER_END_EVT:
408 default:
409 goto illegal_evt;
410 }
411 break;
412 case LINK_FAILINGOVER:
413 switch (evt) {
414 case LINK_FAILOVER_END_EVT:
415 l->state = LINK_RESET;
416 break;
417 case LINK_PEER_RESET_EVT:
418 case LINK_RESET_EVT:
419 case LINK_ESTABLISH_EVT:
420 case LINK_FAILURE_EVT:
421 break;
422 case LINK_FAILOVER_BEGIN_EVT:
423 case LINK_SYNCH_BEGIN_EVT:
424 case LINK_SYNCH_END_EVT:
425 default:
426 goto illegal_evt;
427 }
428 break;
429 case LINK_ESTABLISHING:
430 switch (evt) {
431 case LINK_ESTABLISH_EVT:
432 l->state = LINK_ESTABLISHED;
433 break;
434 case LINK_FAILOVER_BEGIN_EVT:
435 l->state = LINK_FAILINGOVER;
436 break;
437 case LINK_RESET_EVT:
438 l->state = LINK_RESET;
439 break;
440 case LINK_FAILURE_EVT:
441 case LINK_PEER_RESET_EVT:
442 case LINK_SYNCH_BEGIN_EVT:
443 case LINK_FAILOVER_END_EVT:
444 break;
445 case LINK_SYNCH_END_EVT:
446 default:
447 goto illegal_evt;
448 }
449 break;
450 case LINK_ESTABLISHED:
451 switch (evt) {
452 case LINK_PEER_RESET_EVT:
453 l->state = LINK_PEER_RESET;
454 rc |= TIPC_LINK_DOWN_EVT;
455 break;
456 case LINK_FAILURE_EVT:
457 l->state = LINK_RESETTING;
458 rc |= TIPC_LINK_DOWN_EVT;
459 break;
460 case LINK_RESET_EVT:
461 l->state = LINK_RESET;
462 break;
463 case LINK_ESTABLISH_EVT:
464 case LINK_SYNCH_END_EVT:
465 break;
466 case LINK_SYNCH_BEGIN_EVT:
467 l->state = LINK_SYNCHING;
468 break;
469 case LINK_FAILOVER_BEGIN_EVT:
470 case LINK_FAILOVER_END_EVT:
471 default:
472 goto illegal_evt;
473 }
474 break;
475 case LINK_SYNCHING:
476 switch (evt) {
477 case LINK_PEER_RESET_EVT:
478 l->state = LINK_PEER_RESET;
479 rc |= TIPC_LINK_DOWN_EVT;
480 break;
481 case LINK_FAILURE_EVT:
482 l->state = LINK_RESETTING;
483 rc |= TIPC_LINK_DOWN_EVT;
484 break;
485 case LINK_RESET_EVT:
486 l->state = LINK_RESET;
487 break;
488 case LINK_ESTABLISH_EVT:
489 case LINK_SYNCH_BEGIN_EVT:
490 break;
491 case LINK_SYNCH_END_EVT:
492 l->state = LINK_ESTABLISHED;
493 break;
494 case LINK_FAILOVER_BEGIN_EVT:
495 case LINK_FAILOVER_END_EVT:
496 default:
497 goto illegal_evt;
498 }
499 break;
500 default:
501 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
502 }
503 return rc;
504 illegal_evt:
505 pr_err("Illegal FSM event %x in state %x on link %s\n",
506 evt, l->state, l->name);
507 return rc;
508 }
509
510 /* link_profile_stats - update statistical profiling of traffic
511 */
512 static void link_profile_stats(struct tipc_link *l)
513 {
514 struct sk_buff *skb;
515 struct tipc_msg *msg;
516 int length;
517
518 /* Update counters used in statistical profiling of send traffic */
519 l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
520 l->stats.queue_sz_counts++;
521
522 skb = skb_peek(&l->transmq);
523 if (!skb)
524 return;
525 msg = buf_msg(skb);
526 length = msg_size(msg);
527
528 if (msg_user(msg) == MSG_FRAGMENTER) {
529 if (msg_type(msg) != FIRST_FRAGMENT)
530 return;
531 length = msg_size(msg_get_wrapped(msg));
532 }
533 l->stats.msg_lengths_total += length;
534 l->stats.msg_length_counts++;
535 if (length <= 64)
536 l->stats.msg_length_profile[0]++;
537 else if (length <= 256)
538 l->stats.msg_length_profile[1]++;
539 else if (length <= 1024)
540 l->stats.msg_length_profile[2]++;
541 else if (length <= 4096)
542 l->stats.msg_length_profile[3]++;
543 else if (length <= 16384)
544 l->stats.msg_length_profile[4]++;
545 else if (length <= 32768)
546 l->stats.msg_length_profile[5]++;
547 else
548 l->stats.msg_length_profile[6]++;
549 }
550
551 /* tipc_link_timeout - perform periodic task as instructed from node timeout
552 */
553 /* tipc_link_timeout - perform periodic task as instructed from node timeout
554 */
555 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
556 {
557 int rc = 0;
558 int mtyp = STATE_MSG;
559 bool xmit = false;
560 bool prb = false;
561 u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
562 u16 bc_acked = l->bc_rcvlink->acked;
563 bool bc_up = link_is_up(l->bc_rcvlink);
564
565 link_profile_stats(l);
566
567 switch (l->state) {
568 case LINK_ESTABLISHED:
569 case LINK_SYNCHING:
570 if (!l->silent_intv_cnt) {
571 if (bc_up && (bc_acked != bc_snt))
572 xmit = true;
573 } else if (l->silent_intv_cnt <= l->abort_limit) {
574 xmit = true;
575 prb = true;
576 } else {
577 rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
578 }
579 l->silent_intv_cnt++;
580 break;
581 case LINK_RESET:
582 xmit = true;
583 mtyp = RESET_MSG;
584 break;
585 case LINK_ESTABLISHING:
586 xmit = true;
587 mtyp = ACTIVATE_MSG;
588 break;
589 case LINK_PEER_RESET:
590 case LINK_RESETTING:
591 case LINK_FAILINGOVER:
592 break;
593 default:
594 break;
595 }
596
597 if (xmit)
598 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
599
600 return rc;
601 }
602
603 /**
604 * link_schedule_user - schedule a message sender for wakeup after congestion
605 * @link: congested link
606 * @list: message that was attempted sent
607 * Create pseudo msg to send back to user when congestion abates
608 * Does not consume buffer list
609 */
610 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
611 {
612 struct tipc_msg *msg = buf_msg(skb_peek(list));
613 int imp = msg_importance(msg);
614 u32 oport = msg_origport(msg);
615 u32 addr = link_own_addr(link);
616 struct sk_buff *skb;
617
618 /* This really cannot happen... */
619 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
620 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
621 return -ENOBUFS;
622 }
623 /* Non-blocking sender: */
624 if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
625 return -ELINKCONG;
626
627 /* Create and schedule wakeup pseudo message */
628 skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
629 addr, addr, oport, 0, 0);
630 if (!skb)
631 return -ENOBUFS;
632 TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
633 TIPC_SKB_CB(skb)->chain_imp = imp;
634 skb_queue_tail(&link->wakeupq, skb);
635 link->stats.link_congs++;
636 return -ELINKCONG;
637 }
638
639 /**
640 * link_prepare_wakeup - prepare users for wakeup after congestion
641 * @link: congested link
642 * Move a number of waiting users, as permitted by available space in
643 * the send queue, from link wait queue to node wait queue for wakeup
644 */
645 void link_prepare_wakeup(struct tipc_link *l)
646 {
647 int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
648 int imp, lim;
649 struct sk_buff *skb, *tmp;
650
651 skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
652 imp = TIPC_SKB_CB(skb)->chain_imp;
653 lim = l->window + l->backlog[imp].limit;
654 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
655 if ((pnd[imp] + l->backlog[imp].len) >= lim)
656 break;
657 skb_unlink(skb, &l->wakeupq);
658 skb_queue_tail(l->inputq, skb);
659 }
660 }
661
662 void tipc_link_reset(struct tipc_link *l)
663 {
664 /* Link is down, accept any session */
665 l->peer_session = WILDCARD_SESSION;
666
667 /* If peer is up, it only accepts an incremented session number */
668 msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
669
670 /* Prepare for renewed mtu size negotiation */
671 l->mtu = l->advertised_mtu;
672
673 /* Clean up all queues and counters: */
674 __skb_queue_purge(&l->transmq);
675 __skb_queue_purge(&l->deferdq);
676 skb_queue_splice_init(&l->wakeupq, l->inputq);
677 __skb_queue_purge(&l->backlogq);
678 l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
679 l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
680 l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
681 l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
682 l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
683 kfree_skb(l->reasm_buf);
684 kfree_skb(l->failover_reasm_skb);
685 l->reasm_buf = NULL;
686 l->failover_reasm_skb = NULL;
687 l->rcv_unacked = 0;
688 l->snd_nxt = 1;
689 l->rcv_nxt = 1;
690 l->acked = 0;
691 l->silent_intv_cnt = 0;
692 l->stats.recv_info = 0;
693 l->stale_count = 0;
694 l->bc_peer_is_up = false;
695 link_reset_statistics(l);
696 }
697
698 /**
699 * tipc_link_xmit(): enqueue buffer list according to queue situation
700 * @link: link to use
701 * @list: chain of buffers containing message
702 * @xmitq: returned list of packets to be sent by caller
703 *
704 * Consumes the buffer chain, except when returning -ELINKCONG,
705 * since the caller then may want to make more send attempts.
706 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
707 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
708 */
709 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
710 struct sk_buff_head *xmitq)
711 {
712 struct tipc_msg *hdr = buf_msg(skb_peek(list));
713 unsigned int maxwin = l->window;
714 unsigned int i, imp = msg_importance(hdr);
715 unsigned int mtu = l->mtu;
716 u16 ack = l->rcv_nxt - 1;
717 u16 seqno = l->snd_nxt;
718 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
719 struct sk_buff_head *transmq = &l->transmq;
720 struct sk_buff_head *backlogq = &l->backlogq;
721 struct sk_buff *skb, *_skb, *bskb;
722
723 /* Match msg importance against this and all higher backlog limits: */
724 for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
725 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
726 return link_schedule_user(l, list);
727 }
728 if (unlikely(msg_size(hdr) > mtu))
729 return -EMSGSIZE;
730
731 /* Prepare each packet for sending, and add to relevant queue: */
732 while (skb_queue_len(list)) {
733 skb = skb_peek(list);
734 hdr = buf_msg(skb);
735 msg_set_seqno(hdr, seqno);
736 msg_set_ack(hdr, ack);
737 msg_set_bcast_ack(hdr, bc_ack);
738
739 if (likely(skb_queue_len(transmq) < maxwin)) {
740 _skb = skb_clone(skb, GFP_ATOMIC);
741 if (!_skb)
742 return -ENOBUFS;
743 __skb_dequeue(list);
744 __skb_queue_tail(transmq, skb);
745 __skb_queue_tail(xmitq, _skb);
746 TIPC_SKB_CB(skb)->ackers = l->ackers;
747 l->rcv_unacked = 0;
748 seqno++;
749 continue;
750 }
751 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
752 kfree_skb(__skb_dequeue(list));
753 l->stats.sent_bundled++;
754 continue;
755 }
756 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
757 kfree_skb(__skb_dequeue(list));
758 __skb_queue_tail(backlogq, bskb);
759 l->backlog[msg_importance(buf_msg(bskb))].len++;
760 l->stats.sent_bundled++;
761 l->stats.sent_bundles++;
762 continue;
763 }
764 l->backlog[imp].len += skb_queue_len(list);
765 skb_queue_splice_tail_init(list, backlogq);
766 }
767 l->snd_nxt = seqno;
768 return 0;
769 }
770
771 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
772 {
773 struct sk_buff *skb, *_skb;
774 struct tipc_msg *hdr;
775 u16 seqno = l->snd_nxt;
776 u16 ack = l->rcv_nxt - 1;
777 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
778
779 while (skb_queue_len(&l->transmq) < l->window) {
780 skb = skb_peek(&l->backlogq);
781 if (!skb)
782 break;
783 _skb = skb_clone(skb, GFP_ATOMIC);
784 if (!_skb)
785 break;
786 __skb_dequeue(&l->backlogq);
787 hdr = buf_msg(skb);
788 l->backlog[msg_importance(hdr)].len--;
789 __skb_queue_tail(&l->transmq, skb);
790 __skb_queue_tail(xmitq, _skb);
791 TIPC_SKB_CB(skb)->ackers = l->ackers;
792 msg_set_seqno(hdr, seqno);
793 msg_set_ack(hdr, ack);
794 msg_set_bcast_ack(hdr, bc_ack);
795 l->rcv_unacked = 0;
796 seqno++;
797 }
798 l->snd_nxt = seqno;
799 }
800
801 static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
802 {
803 struct tipc_msg *hdr = buf_msg(skb);
804
805 pr_warn("Retransmission failure on link <%s>\n", l->name);
806 link_print(l, "Resetting link ");
807 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
808 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
809 pr_info("sqno %u, prev: %x, src: %x\n",
810 msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
811 }
812
813 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
814 struct sk_buff_head *xmitq)
815 {
816 struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
817 struct tipc_msg *hdr;
818 u16 ack = l->rcv_nxt - 1;
819 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
820
821 if (!skb)
822 return 0;
823
824 /* Detect repeated retransmit failures on same packet */
825 if (likely(l->last_retransm != buf_seqno(skb))) {
826 l->last_retransm = buf_seqno(skb);
827 l->stale_count = 1;
828 } else if (++l->stale_count > 100) {
829 link_retransmit_failure(l, skb);
830 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
831 }
832
833 /* Move forward to where retransmission should start */
834 skb_queue_walk(&l->transmq, skb) {
835 if (!less(buf_seqno(skb), from))
836 break;
837 }
838
839 skb_queue_walk_from(&l->transmq, skb) {
840 if (more(buf_seqno(skb), to))
841 break;
842 hdr = buf_msg(skb);
843 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
844 if (!_skb)
845 return 0;
846 hdr = buf_msg(_skb);
847 msg_set_ack(hdr, ack);
848 msg_set_bcast_ack(hdr, bc_ack);
849 _skb->priority = TC_PRIO_CONTROL;
850 __skb_queue_tail(xmitq, _skb);
851 l->stats.retransmitted++;
852 }
853 return 0;
854 }
855
856 /* tipc_data_input - deliver data and name distr msgs to upper layer
857 *
858 * Consumes buffer if message is of right type
859 * Node lock must be held
860 */
861 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
862 struct sk_buff_head *inputq)
863 {
864 switch (msg_user(buf_msg(skb))) {
865 case TIPC_LOW_IMPORTANCE:
866 case TIPC_MEDIUM_IMPORTANCE:
867 case TIPC_HIGH_IMPORTANCE:
868 case TIPC_CRITICAL_IMPORTANCE:
869 case CONN_MANAGER:
870 skb_queue_tail(inputq, skb);
871 return true;
872 case NAME_DISTRIBUTOR:
873 l->bc_rcvlink->state = LINK_ESTABLISHED;
874 skb_queue_tail(l->namedq, skb);
875 return true;
876 case MSG_BUNDLER:
877 case TUNNEL_PROTOCOL:
878 case MSG_FRAGMENTER:
879 case BCAST_PROTOCOL:
880 return false;
881 default:
882 pr_warn("Dropping received illegal msg type\n");
883 kfree_skb(skb);
884 return false;
885 };
886 }
887
888 /* tipc_link_input - process packet that has passed link protocol check
889 *
890 * Consumes buffer
891 */
892 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
893 struct sk_buff_head *inputq)
894 {
895 struct tipc_msg *hdr = buf_msg(skb);
896 struct sk_buff **reasm_skb = &l->reasm_buf;
897 struct sk_buff *iskb;
898 struct sk_buff_head tmpq;
899 int usr = msg_user(hdr);
900 int rc = 0;
901 int pos = 0;
902 int ipos = 0;
903
904 if (unlikely(usr == TUNNEL_PROTOCOL)) {
905 if (msg_type(hdr) == SYNCH_MSG) {
906 __skb_queue_purge(&l->deferdq);
907 goto drop;
908 }
909 if (!tipc_msg_extract(skb, &iskb, &ipos))
910 return rc;
911 kfree_skb(skb);
912 skb = iskb;
913 hdr = buf_msg(skb);
914 if (less(msg_seqno(hdr), l->drop_point))
915 goto drop;
916 if (tipc_data_input(l, skb, inputq))
917 return rc;
918 usr = msg_user(hdr);
919 reasm_skb = &l->failover_reasm_skb;
920 }
921
922 if (usr == MSG_BUNDLER) {
923 skb_queue_head_init(&tmpq);
924 l->stats.recv_bundles++;
925 l->stats.recv_bundled += msg_msgcnt(hdr);
926 while (tipc_msg_extract(skb, &iskb, &pos))
927 tipc_data_input(l, iskb, &tmpq);
928 tipc_skb_queue_splice_tail(&tmpq, inputq);
929 return 0;
930 } else if (usr == MSG_FRAGMENTER) {
931 l->stats.recv_fragments++;
932 if (tipc_buf_append(reasm_skb, &skb)) {
933 l->stats.recv_fragmented++;
934 tipc_data_input(l, skb, inputq);
935 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
936 pr_warn_ratelimited("Unable to build fragment list\n");
937 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
938 }
939 return 0;
940 } else if (usr == BCAST_PROTOCOL) {
941 tipc_bcast_lock(l->net);
942 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
943 tipc_bcast_unlock(l->net);
944 }
945 drop:
946 kfree_skb(skb);
947 return 0;
948 }
949
950 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
951 {
952 bool released = false;
953 struct sk_buff *skb, *tmp;
954
955 skb_queue_walk_safe(&l->transmq, skb, tmp) {
956 if (more(buf_seqno(skb), acked))
957 break;
958 __skb_unlink(skb, &l->transmq);
959 kfree_skb(skb);
960 released = true;
961 }
962 return released;
963 }
964
965 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
966 *
967 * Note that sending of broadcast ack is coordinated among nodes, to reduce
968 * risk of ack storms towards the sender
969 */
970 int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
971 {
972 if (!l)
973 return 0;
974
975 /* Broadcast ACK must be sent via a unicast link => defer to caller */
976 if (link_is_bc_rcvlink(l)) {
977 if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf)
978 return 0;
979 l->rcv_unacked = 0;
980 return TIPC_LINK_SND_BC_ACK;
981 }
982
983 /* Unicast ACK */
984 l->rcv_unacked = 0;
985 l->stats.sent_acks++;
986 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
987 return 0;
988 }
989
990 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
991 */
992 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
993 {
994 int mtyp = RESET_MSG;
995
996 if (l->state == LINK_ESTABLISHING)
997 mtyp = ACTIVATE_MSG;
998
999 tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1000 }
1001
1002 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1003 */
1004 static void tipc_link_build_nack_msg(struct tipc_link *l,
1005 struct sk_buff_head *xmitq)
1006 {
1007 u32 def_cnt = ++l->stats.deferred_recv;
1008
1009 if (link_is_bc_rcvlink(l))
1010 return;
1011
1012 if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1013 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1014 }
1015
1016 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1017 * @l: the link that should handle the message
1018 * @skb: TIPC packet
1019 * @xmitq: queue to place packets to be sent after this call
1020 */
1021 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1022 struct sk_buff_head *xmitq)
1023 {
1024 struct sk_buff_head *defq = &l->deferdq;
1025 struct tipc_msg *hdr;
1026 u16 seqno, rcv_nxt, win_lim;
1027 int rc = 0;
1028
1029 do {
1030 hdr = buf_msg(skb);
1031 seqno = msg_seqno(hdr);
1032 rcv_nxt = l->rcv_nxt;
1033 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1034
1035 /* Verify and update link state */
1036 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1037 return tipc_link_proto_rcv(l, skb, xmitq);
1038
1039 if (unlikely(!link_is_up(l))) {
1040 if (l->state == LINK_ESTABLISHING)
1041 rc = TIPC_LINK_UP_EVT;
1042 goto drop;
1043 }
1044
1045 /* Don't send probe at next timeout expiration */
1046 l->silent_intv_cnt = 0;
1047
1048 /* Drop if outside receive window */
1049 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1050 l->stats.duplicates++;
1051 goto drop;
1052 }
1053
1054 /* Forward queues and wake up waiting users */
1055 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1056 tipc_link_advance_backlog(l, xmitq);
1057 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1058 link_prepare_wakeup(l);
1059 }
1060
1061 /* Defer delivery if sequence gap */
1062 if (unlikely(seqno != rcv_nxt)) {
1063 __tipc_skb_queue_sorted(defq, seqno, skb);
1064 tipc_link_build_nack_msg(l, xmitq);
1065 break;
1066 }
1067
1068 /* Deliver packet */
1069 l->rcv_nxt++;
1070 l->stats.recv_info++;
1071 if (!tipc_data_input(l, skb, l->inputq))
1072 rc |= tipc_link_input(l, skb, l->inputq);
1073 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1074 rc |= tipc_link_build_ack_msg(l, xmitq);
1075 if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
1076 break;
1077 } while ((skb = __skb_dequeue(defq)));
1078
1079 return rc;
1080 drop:
1081 kfree_skb(skb);
1082 return rc;
1083 }
1084
1085 /*
1086 * Send protocol message to the other endpoint.
1087 */
1088 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1089 u32 gap, u32 tolerance, u32 priority)
1090 {
1091 struct sk_buff *skb = NULL;
1092 struct sk_buff_head xmitq;
1093
1094 __skb_queue_head_init(&xmitq);
1095 tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1096 tolerance, priority, &xmitq);
1097 skb = __skb_dequeue(&xmitq);
1098 if (!skb)
1099 return;
1100 tipc_bearer_xmit_skb(l->net, l->bearer_id, skb, l->media_addr);
1101 l->rcv_unacked = 0;
1102 }
1103
1104 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1105 u16 rcvgap, int tolerance, int priority,
1106 struct sk_buff_head *xmitq)
1107 {
1108 struct sk_buff *skb = NULL;
1109 struct tipc_msg *hdr = l->pmsg;
1110 bool node_up = link_is_up(l->bc_rcvlink);
1111
1112 /* Don't send protocol message during reset or link failover */
1113 if (tipc_link_is_blocked(l))
1114 return;
1115
1116 msg_set_type(hdr, mtyp);
1117 msg_set_net_plane(hdr, l->net_plane);
1118 msg_set_next_sent(hdr, l->snd_nxt);
1119 msg_set_ack(hdr, l->rcv_nxt - 1);
1120 msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
1121 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1122 msg_set_link_tolerance(hdr, tolerance);
1123 msg_set_linkprio(hdr, priority);
1124 msg_set_redundant_link(hdr, node_up);
1125 msg_set_seq_gap(hdr, 0);
1126
1127 /* Compatibility: created msg must not be in sequence with pkt flow */
1128 msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1129
1130 if (mtyp == STATE_MSG) {
1131 if (!tipc_link_is_up(l))
1132 return;
1133
1134 /* Override rcvgap if there are packets in deferred queue */
1135 if (!skb_queue_empty(&l->deferdq))
1136 rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
1137 if (rcvgap) {
1138 msg_set_seq_gap(hdr, rcvgap);
1139 l->stats.sent_nacks++;
1140 }
1141 msg_set_probe(hdr, probe);
1142 if (probe)
1143 l->stats.sent_probes++;
1144 l->stats.sent_states++;
1145 l->rcv_unacked = 0;
1146 } else {
1147 /* RESET_MSG or ACTIVATE_MSG */
1148 msg_set_max_pkt(hdr, l->advertised_mtu);
1149 msg_set_ack(hdr, l->rcv_nxt - 1);
1150 msg_set_next_sent(hdr, 1);
1151 }
1152 skb = tipc_buf_acquire(msg_size(hdr));
1153 if (!skb)
1154 return;
1155 skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1156 skb->priority = TC_PRIO_CONTROL;
1157 __skb_queue_tail(xmitq, skb);
1158 }
1159
1160 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1161 * with contents of the link's transmit and backlog queues.
1162 */
1163 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1164 int mtyp, struct sk_buff_head *xmitq)
1165 {
1166 struct sk_buff *skb, *tnlskb;
1167 struct tipc_msg *hdr, tnlhdr;
1168 struct sk_buff_head *queue = &l->transmq;
1169 struct sk_buff_head tmpxq, tnlq;
1170 u16 pktlen, pktcnt, seqno = l->snd_nxt;
1171
1172 if (!tnl)
1173 return;
1174
1175 skb_queue_head_init(&tnlq);
1176 skb_queue_head_init(&tmpxq);
1177
1178 /* At least one packet required for safe algorithm => add dummy */
1179 skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1180 BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
1181 0, 0, TIPC_ERR_NO_PORT);
1182 if (!skb) {
1183 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1184 return;
1185 }
1186 skb_queue_tail(&tnlq, skb);
1187 tipc_link_xmit(l, &tnlq, &tmpxq);
1188 __skb_queue_purge(&tmpxq);
1189
1190 /* Initialize reusable tunnel packet header */
1191 tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
1192 mtyp, INT_H_SIZE, l->addr);
1193 pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1194 msg_set_msgcnt(&tnlhdr, pktcnt);
1195 msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1196 tnl:
1197 /* Wrap each packet into a tunnel packet */
1198 skb_queue_walk(queue, skb) {
1199 hdr = buf_msg(skb);
1200 if (queue == &l->backlogq)
1201 msg_set_seqno(hdr, seqno++);
1202 pktlen = msg_size(hdr);
1203 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1204 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1205 if (!tnlskb) {
1206 pr_warn("%sunable to send packet\n", link_co_err);
1207 return;
1208 }
1209 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1210 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1211 __skb_queue_tail(&tnlq, tnlskb);
1212 }
1213 if (queue != &l->backlogq) {
1214 queue = &l->backlogq;
1215 goto tnl;
1216 }
1217
1218 tipc_link_xmit(tnl, &tnlq, xmitq);
1219
1220 if (mtyp == FAILOVER_MSG) {
1221 tnl->drop_point = l->rcv_nxt;
1222 tnl->failover_reasm_skb = l->reasm_buf;
1223 l->reasm_buf = NULL;
1224 }
1225 }
1226
1227 /* tipc_link_proto_rcv(): receive link level protocol message :
1228 * Note that network plane id propagates through the network, and may
1229 * change at any time. The node with lowest numerical id determines
1230 * network plane
1231 */
1232 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1233 struct sk_buff_head *xmitq)
1234 {
1235 struct tipc_msg *hdr = buf_msg(skb);
1236 u16 rcvgap = 0;
1237 u16 ack = msg_ack(hdr);
1238 u16 gap = msg_seq_gap(hdr);
1239 u16 peers_snd_nxt = msg_next_sent(hdr);
1240 u16 peers_tol = msg_link_tolerance(hdr);
1241 u16 peers_prio = msg_linkprio(hdr);
1242 u16 rcv_nxt = l->rcv_nxt;
1243 int mtyp = msg_type(hdr);
1244 char *if_name;
1245 int rc = 0;
1246
1247 if (tipc_link_is_blocked(l) || !xmitq)
1248 goto exit;
1249
1250 if (link_own_addr(l) > msg_prevnode(hdr))
1251 l->net_plane = msg_net_plane(hdr);
1252
1253 switch (mtyp) {
1254 case RESET_MSG:
1255
1256 /* Ignore duplicate RESET with old session number */
1257 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1258 (l->peer_session != WILDCARD_SESSION))
1259 break;
1260 /* fall thru' */
1261
1262 case ACTIVATE_MSG:
1263
1264 /* Complete own link name with peer's interface name */
1265 if_name = strrchr(l->name, ':') + 1;
1266 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1267 break;
1268 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1269 break;
1270 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1271
1272 /* Update own tolerance if peer indicates a non-zero value */
1273 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1274 l->tolerance = peers_tol;
1275
1276 /* Update own priority if peer's priority is higher */
1277 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1278 l->priority = peers_prio;
1279
1280 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1281 if ((mtyp == RESET_MSG) || !link_is_up(l))
1282 rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1283
1284 /* ACTIVATE_MSG takes up link if it was already locally reset */
1285 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1286 rc = TIPC_LINK_UP_EVT;
1287
1288 l->peer_session = msg_session(hdr);
1289 l->peer_bearer_id = msg_bearer_id(hdr);
1290 if (l->mtu > msg_max_pkt(hdr))
1291 l->mtu = msg_max_pkt(hdr);
1292 break;
1293
1294 case STATE_MSG:
1295
1296 /* Update own tolerance if peer indicates a non-zero value */
1297 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1298 l->tolerance = peers_tol;
1299
1300 l->silent_intv_cnt = 0;
1301 l->stats.recv_states++;
1302 if (msg_probe(hdr))
1303 l->stats.recv_probes++;
1304
1305 if (!link_is_up(l)) {
1306 if (l->state == LINK_ESTABLISHING)
1307 rc = TIPC_LINK_UP_EVT;
1308 break;
1309 }
1310
1311 /* Send NACK if peer has sent pkts we haven't received yet */
1312 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1313 rcvgap = peers_snd_nxt - l->rcv_nxt;
1314 if (rcvgap || (msg_probe(hdr)))
1315 tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1316 0, 0, xmitq);
1317 tipc_link_release_pkts(l, ack);
1318
1319 /* If NACK, retransmit will now start at right position */
1320 if (gap) {
1321 rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1322 l->stats.recv_nacks++;
1323 }
1324
1325 tipc_link_advance_backlog(l, xmitq);
1326 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1327 link_prepare_wakeup(l);
1328 }
1329 exit:
1330 kfree_skb(skb);
1331 return rc;
1332 }
1333
1334 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1335 */
1336 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1337 u16 peers_snd_nxt,
1338 struct sk_buff_head *xmitq)
1339 {
1340 struct sk_buff *skb;
1341 struct tipc_msg *hdr;
1342 struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1343 u16 ack = l->rcv_nxt - 1;
1344 u16 gap_to = peers_snd_nxt - 1;
1345
1346 skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1347 0, l->addr, link_own_addr(l), 0, 0, 0);
1348 if (!skb)
1349 return false;
1350 hdr = buf_msg(skb);
1351 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1352 msg_set_bcast_ack(hdr, ack);
1353 msg_set_bcgap_after(hdr, ack);
1354 if (dfrd_skb)
1355 gap_to = buf_seqno(dfrd_skb) - 1;
1356 msg_set_bcgap_to(hdr, gap_to);
1357 msg_set_non_seq(hdr, bcast);
1358 __skb_queue_tail(xmitq, skb);
1359 return true;
1360 }
1361
1362 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1363 *
1364 * Give a newly added peer node the sequence number where it should
1365 * start receiving and acking broadcast packets.
1366 */
1367 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1368 struct sk_buff_head *xmitq)
1369 {
1370 struct sk_buff_head list;
1371
1372 __skb_queue_head_init(&list);
1373 if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1374 return;
1375 tipc_link_xmit(l, &list, xmitq);
1376 }
1377
1378 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1379 */
1380 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1381 {
1382 int mtyp = msg_type(hdr);
1383 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1384
1385 if (link_is_up(l))
1386 return;
1387
1388 if (msg_user(hdr) == BCAST_PROTOCOL) {
1389 l->rcv_nxt = peers_snd_nxt;
1390 l->state = LINK_ESTABLISHED;
1391 return;
1392 }
1393
1394 if (l->peer_caps & TIPC_BCAST_SYNCH)
1395 return;
1396
1397 if (msg_peer_node_is_up(hdr))
1398 return;
1399
1400 /* Compatibility: accept older, less safe initial synch data */
1401 if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1402 l->rcv_nxt = peers_snd_nxt;
1403 }
1404
1405 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1406 */
1407 void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1408 struct sk_buff_head *xmitq)
1409 {
1410 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1411
1412 if (!link_is_up(l))
1413 return;
1414
1415 if (!msg_peer_node_is_up(hdr))
1416 return;
1417
1418 l->bc_peer_is_up = true;
1419
1420 /* Ignore if peers_snd_nxt goes beyond receive window */
1421 if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1422 return;
1423
1424 if (!more(peers_snd_nxt, l->rcv_nxt)) {
1425 l->nack_state = BC_NACK_SND_CONDITIONAL;
1426 return;
1427 }
1428
1429 /* Don't NACK if one was recently sent or peeked */
1430 if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1431 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1432 return;
1433 }
1434
1435 /* Conditionally delay NACK sending until next synch rcv */
1436 if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1437 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1438 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1439 return;
1440 }
1441
1442 /* Send NACK now but suppress next one */
1443 tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1444 l->nack_state = BC_NACK_SND_SUPPRESS;
1445 }
1446
1447 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1448 struct sk_buff_head *xmitq)
1449 {
1450 struct sk_buff *skb, *tmp;
1451 struct tipc_link *snd_l = l->bc_sndlink;
1452
1453 if (!link_is_up(l) || !l->bc_peer_is_up)
1454 return;
1455
1456 if (!more(acked, l->acked))
1457 return;
1458
1459 /* Skip over packets peer has already acked */
1460 skb_queue_walk(&snd_l->transmq, skb) {
1461 if (more(buf_seqno(skb), l->acked))
1462 break;
1463 }
1464
1465 /* Update/release the packets peer is acking now */
1466 skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1467 if (more(buf_seqno(skb), acked))
1468 break;
1469 if (!--TIPC_SKB_CB(skb)->ackers) {
1470 __skb_unlink(skb, &snd_l->transmq);
1471 kfree_skb(skb);
1472 }
1473 }
1474 l->acked = acked;
1475 tipc_link_advance_backlog(snd_l, xmitq);
1476 if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1477 link_prepare_wakeup(snd_l);
1478 }
1479
1480 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
1481 */
1482 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1483 struct sk_buff_head *xmitq)
1484 {
1485 struct tipc_msg *hdr = buf_msg(skb);
1486 u32 dnode = msg_destnode(hdr);
1487 int mtyp = msg_type(hdr);
1488 u16 acked = msg_bcast_ack(hdr);
1489 u16 from = acked + 1;
1490 u16 to = msg_bcgap_to(hdr);
1491 u16 peers_snd_nxt = to + 1;
1492 int rc = 0;
1493
1494 kfree_skb(skb);
1495
1496 if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1497 return 0;
1498
1499 if (mtyp != STATE_MSG)
1500 return 0;
1501
1502 if (dnode == link_own_addr(l)) {
1503 tipc_link_bc_ack_rcv(l, acked, xmitq);
1504 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1505 l->stats.recv_nacks++;
1506 return rc;
1507 }
1508
1509 /* Msg for other node => suppress own NACK at next sync if applicable */
1510 if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1511 l->nack_state = BC_NACK_SND_SUPPRESS;
1512
1513 return 0;
1514 }
1515
1516 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1517 {
1518 int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1519
1520 l->window = win;
1521 l->backlog[TIPC_LOW_IMPORTANCE].limit = win / 2;
1522 l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = win;
1523 l->backlog[TIPC_HIGH_IMPORTANCE].limit = win / 2 * 3;
1524 l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1525 l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
1526 }
1527
1528 /* tipc_link_find_owner - locate owner node of link by link's name
1529 * @net: the applicable net namespace
1530 * @name: pointer to link name string
1531 * @bearer_id: pointer to index in 'node->links' array where the link was found.
1532 *
1533 * Returns pointer to node owning the link, or 0 if no matching link is found.
1534 */
1535 static struct tipc_node *tipc_link_find_owner(struct net *net,
1536 const char *link_name,
1537 unsigned int *bearer_id)
1538 {
1539 struct tipc_net *tn = net_generic(net, tipc_net_id);
1540 struct tipc_link *l_ptr;
1541 struct tipc_node *n_ptr;
1542 struct tipc_node *found_node = NULL;
1543 int i;
1544
1545 *bearer_id = 0;
1546 rcu_read_lock();
1547 list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1548 tipc_node_lock(n_ptr);
1549 for (i = 0; i < MAX_BEARERS; i++) {
1550 l_ptr = n_ptr->links[i].link;
1551 if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1552 *bearer_id = i;
1553 found_node = n_ptr;
1554 break;
1555 }
1556 }
1557 tipc_node_unlock(n_ptr);
1558 if (found_node)
1559 break;
1560 }
1561 rcu_read_unlock();
1562
1563 return found_node;
1564 }
1565
1566 /**
1567 * link_reset_statistics - reset link statistics
1568 * @l_ptr: pointer to link
1569 */
1570 static void link_reset_statistics(struct tipc_link *l_ptr)
1571 {
1572 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1573 l_ptr->stats.sent_info = l_ptr->snd_nxt;
1574 l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1575 }
1576
1577 static void link_print(struct tipc_link *l, const char *str)
1578 {
1579 struct sk_buff *hskb = skb_peek(&l->transmq);
1580 u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1581 u16 tail = l->snd_nxt - 1;
1582
1583 pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1584 pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1585 skb_queue_len(&l->transmq), head, tail,
1586 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1587 }
1588
1589 /* Parse and validate nested (link) properties valid for media, bearer and link
1590 */
1591 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1592 {
1593 int err;
1594
1595 err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1596 tipc_nl_prop_policy);
1597 if (err)
1598 return err;
1599
1600 if (props[TIPC_NLA_PROP_PRIO]) {
1601 u32 prio;
1602
1603 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1604 if (prio > TIPC_MAX_LINK_PRI)
1605 return -EINVAL;
1606 }
1607
1608 if (props[TIPC_NLA_PROP_TOL]) {
1609 u32 tol;
1610
1611 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1612 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1613 return -EINVAL;
1614 }
1615
1616 if (props[TIPC_NLA_PROP_WIN]) {
1617 u32 win;
1618
1619 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1620 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1621 return -EINVAL;
1622 }
1623
1624 return 0;
1625 }
1626
1627 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1628 {
1629 int err;
1630 int res = 0;
1631 int bearer_id;
1632 char *name;
1633 struct tipc_link *link;
1634 struct tipc_node *node;
1635 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1636 struct net *net = sock_net(skb->sk);
1637
1638 if (!info->attrs[TIPC_NLA_LINK])
1639 return -EINVAL;
1640
1641 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1642 info->attrs[TIPC_NLA_LINK],
1643 tipc_nl_link_policy);
1644 if (err)
1645 return err;
1646
1647 if (!attrs[TIPC_NLA_LINK_NAME])
1648 return -EINVAL;
1649
1650 name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1651
1652 if (strcmp(name, tipc_bclink_name) == 0)
1653 return tipc_nl_bc_link_set(net, attrs);
1654
1655 node = tipc_link_find_owner(net, name, &bearer_id);
1656 if (!node)
1657 return -EINVAL;
1658
1659 tipc_node_lock(node);
1660
1661 link = node->links[bearer_id].link;
1662 if (!link) {
1663 res = -EINVAL;
1664 goto out;
1665 }
1666
1667 if (attrs[TIPC_NLA_LINK_PROP]) {
1668 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1669
1670 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1671 props);
1672 if (err) {
1673 res = err;
1674 goto out;
1675 }
1676
1677 if (props[TIPC_NLA_PROP_TOL]) {
1678 u32 tol;
1679
1680 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1681 link->tolerance = tol;
1682 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1683 }
1684 if (props[TIPC_NLA_PROP_PRIO]) {
1685 u32 prio;
1686
1687 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1688 link->priority = prio;
1689 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1690 }
1691 if (props[TIPC_NLA_PROP_WIN]) {
1692 u32 win;
1693
1694 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1695 tipc_link_set_queue_limits(link, win);
1696 }
1697 }
1698
1699 out:
1700 tipc_node_unlock(node);
1701
1702 return res;
1703 }
1704
1705 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1706 {
1707 int i;
1708 struct nlattr *stats;
1709
1710 struct nla_map {
1711 u32 key;
1712 u32 val;
1713 };
1714
1715 struct nla_map map[] = {
1716 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1717 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1718 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1719 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1720 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1721 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1722 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1723 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1724 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1725 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1726 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1727 s->msg_length_counts : 1},
1728 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1729 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1730 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1731 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1732 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1733 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1734 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1735 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1736 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1737 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1738 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1739 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1740 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1741 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1742 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1743 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1744 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1745 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1746 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1747 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1748 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1749 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1750 (s->accu_queue_sz / s->queue_sz_counts) : 0}
1751 };
1752
1753 stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1754 if (!stats)
1755 return -EMSGSIZE;
1756
1757 for (i = 0; i < ARRAY_SIZE(map); i++)
1758 if (nla_put_u32(skb, map[i].key, map[i].val))
1759 goto msg_full;
1760
1761 nla_nest_end(skb, stats);
1762
1763 return 0;
1764 msg_full:
1765 nla_nest_cancel(skb, stats);
1766
1767 return -EMSGSIZE;
1768 }
1769
1770 /* Caller should hold appropriate locks to protect the link */
1771 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1772 struct tipc_link *link, int nlflags)
1773 {
1774 int err;
1775 void *hdr;
1776 struct nlattr *attrs;
1777 struct nlattr *prop;
1778 struct tipc_net *tn = net_generic(net, tipc_net_id);
1779
1780 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1781 nlflags, TIPC_NL_LINK_GET);
1782 if (!hdr)
1783 return -EMSGSIZE;
1784
1785 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1786 if (!attrs)
1787 goto msg_full;
1788
1789 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1790 goto attr_msg_full;
1791 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1792 tipc_cluster_mask(tn->own_addr)))
1793 goto attr_msg_full;
1794 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1795 goto attr_msg_full;
1796 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1797 goto attr_msg_full;
1798 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1799 goto attr_msg_full;
1800
1801 if (tipc_link_is_up(link))
1802 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1803 goto attr_msg_full;
1804 if (link->active)
1805 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1806 goto attr_msg_full;
1807
1808 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1809 if (!prop)
1810 goto attr_msg_full;
1811 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1812 goto prop_msg_full;
1813 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1814 goto prop_msg_full;
1815 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1816 link->window))
1817 goto prop_msg_full;
1818 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1819 goto prop_msg_full;
1820 nla_nest_end(msg->skb, prop);
1821
1822 err = __tipc_nl_add_stats(msg->skb, &link->stats);
1823 if (err)
1824 goto attr_msg_full;
1825
1826 nla_nest_end(msg->skb, attrs);
1827 genlmsg_end(msg->skb, hdr);
1828
1829 return 0;
1830
1831 prop_msg_full:
1832 nla_nest_cancel(msg->skb, prop);
1833 attr_msg_full:
1834 nla_nest_cancel(msg->skb, attrs);
1835 msg_full:
1836 genlmsg_cancel(msg->skb, hdr);
1837
1838 return -EMSGSIZE;
1839 }
1840
1841 /* Caller should hold node lock */
1842 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1843 struct tipc_node *node, u32 *prev_link)
1844 {
1845 u32 i;
1846 int err;
1847
1848 for (i = *prev_link; i < MAX_BEARERS; i++) {
1849 *prev_link = i;
1850
1851 if (!node->links[i].link)
1852 continue;
1853
1854 err = __tipc_nl_add_link(net, msg,
1855 node->links[i].link, NLM_F_MULTI);
1856 if (err)
1857 return err;
1858 }
1859 *prev_link = 0;
1860
1861 return 0;
1862 }
1863
1864 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
1865 {
1866 struct net *net = sock_net(skb->sk);
1867 struct tipc_net *tn = net_generic(net, tipc_net_id);
1868 struct tipc_node *node;
1869 struct tipc_nl_msg msg;
1870 u32 prev_node = cb->args[0];
1871 u32 prev_link = cb->args[1];
1872 int done = cb->args[2];
1873 int err;
1874
1875 if (done)
1876 return 0;
1877
1878 msg.skb = skb;
1879 msg.portid = NETLINK_CB(cb->skb).portid;
1880 msg.seq = cb->nlh->nlmsg_seq;
1881
1882 rcu_read_lock();
1883 if (prev_node) {
1884 node = tipc_node_find(net, prev_node);
1885 if (!node) {
1886 /* We never set seq or call nl_dump_check_consistent()
1887 * this means that setting prev_seq here will cause the
1888 * consistence check to fail in the netlink callback
1889 * handler. Resulting in the last NLMSG_DONE message
1890 * having the NLM_F_DUMP_INTR flag set.
1891 */
1892 cb->prev_seq = 1;
1893 goto out;
1894 }
1895 tipc_node_put(node);
1896
1897 list_for_each_entry_continue_rcu(node, &tn->node_list,
1898 list) {
1899 tipc_node_lock(node);
1900 err = __tipc_nl_add_node_links(net, &msg, node,
1901 &prev_link);
1902 tipc_node_unlock(node);
1903 if (err)
1904 goto out;
1905
1906 prev_node = node->addr;
1907 }
1908 } else {
1909 err = tipc_nl_add_bc_link(net, &msg);
1910 if (err)
1911 goto out;
1912
1913 list_for_each_entry_rcu(node, &tn->node_list, list) {
1914 tipc_node_lock(node);
1915 err = __tipc_nl_add_node_links(net, &msg, node,
1916 &prev_link);
1917 tipc_node_unlock(node);
1918 if (err)
1919 goto out;
1920
1921 prev_node = node->addr;
1922 }
1923 }
1924 done = 1;
1925 out:
1926 rcu_read_unlock();
1927
1928 cb->args[0] = prev_node;
1929 cb->args[1] = prev_link;
1930 cb->args[2] = done;
1931
1932 return skb->len;
1933 }
1934
1935 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
1936 {
1937 struct net *net = genl_info_net(info);
1938 struct tipc_nl_msg msg;
1939 char *name;
1940 int err;
1941
1942 msg.portid = info->snd_portid;
1943 msg.seq = info->snd_seq;
1944
1945 if (!info->attrs[TIPC_NLA_LINK_NAME])
1946 return -EINVAL;
1947 name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
1948
1949 msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1950 if (!msg.skb)
1951 return -ENOMEM;
1952
1953 if (strcmp(name, tipc_bclink_name) == 0) {
1954 err = tipc_nl_add_bc_link(net, &msg);
1955 if (err) {
1956 nlmsg_free(msg.skb);
1957 return err;
1958 }
1959 } else {
1960 int bearer_id;
1961 struct tipc_node *node;
1962 struct tipc_link *link;
1963
1964 node = tipc_link_find_owner(net, name, &bearer_id);
1965 if (!node)
1966 return -EINVAL;
1967
1968 tipc_node_lock(node);
1969 link = node->links[bearer_id].link;
1970 if (!link) {
1971 tipc_node_unlock(node);
1972 nlmsg_free(msg.skb);
1973 return -EINVAL;
1974 }
1975
1976 err = __tipc_nl_add_link(net, &msg, link, 0);
1977 tipc_node_unlock(node);
1978 if (err) {
1979 nlmsg_free(msg.skb);
1980 return err;
1981 }
1982 }
1983
1984 return genlmsg_reply(msg.skb, info);
1985 }
1986
1987 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
1988 {
1989 int err;
1990 char *link_name;
1991 unsigned int bearer_id;
1992 struct tipc_link *link;
1993 struct tipc_node *node;
1994 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1995 struct net *net = sock_net(skb->sk);
1996
1997 if (!info->attrs[TIPC_NLA_LINK])
1998 return -EINVAL;
1999
2000 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2001 info->attrs[TIPC_NLA_LINK],
2002 tipc_nl_link_policy);
2003 if (err)
2004 return err;
2005
2006 if (!attrs[TIPC_NLA_LINK_NAME])
2007 return -EINVAL;
2008
2009 link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2010
2011 if (strcmp(link_name, tipc_bclink_name) == 0) {
2012 err = tipc_bclink_reset_stats(net);
2013 if (err)
2014 return err;
2015 return 0;
2016 }
2017
2018 node = tipc_link_find_owner(net, link_name, &bearer_id);
2019 if (!node)
2020 return -EINVAL;
2021
2022 tipc_node_lock(node);
2023
2024 link = node->links[bearer_id].link;
2025 if (!link) {
2026 tipc_node_unlock(node);
2027 return -EINVAL;
2028 }
2029
2030 link_reset_statistics(link);
2031
2032 tipc_node_unlock(node);
2033
2034 return 0;
2035 }
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