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Merge pull request #3205 from donaldsharp/default
[mirror_frr.git] / bgpd / bgp_fsm.c
1 /* BGP-4 Finite State Machine
2 * From RFC1771 [A Border Gateway Protocol 4 (BGP-4)]
3 * Copyright (C) 1996, 97, 98 Kunihiro Ishiguro
4 *
5 * This file is part of GNU Zebra.
6 *
7 * GNU Zebra is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2, or (at your option) any
10 * later version.
11 *
12 * GNU Zebra is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; see the file COPYING; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <zebra.h>
23
24 #include "linklist.h"
25 #include "prefix.h"
26 #include "sockunion.h"
27 #include "thread.h"
28 #include "log.h"
29 #include "stream.h"
30 #include "ringbuf.h"
31 #include "memory.h"
32 #include "plist.h"
33 #include "workqueue.h"
34 #include "queue.h"
35 #include "filter.h"
36 #include "command.h"
37 #include "lib_errors.h"
38
39 #include "lib/json.h"
40 #include "bgpd/bgpd.h"
41 #include "bgpd/bgp_attr.h"
42 #include "bgpd/bgp_debug.h"
43 #include "bgpd/bgp_errors.h"
44 #include "bgpd/bgp_fsm.h"
45 #include "bgpd/bgp_packet.h"
46 #include "bgpd/bgp_network.h"
47 #include "bgpd/bgp_route.h"
48 #include "bgpd/bgp_dump.h"
49 #include "bgpd/bgp_open.h"
50 #include "bgpd/bgp_advertise.h"
51 #include "bgpd/bgp_updgrp.h"
52 #include "bgpd/bgp_nht.h"
53 #include "bgpd/bgp_bfd.h"
54 #include "bgpd/bgp_memory.h"
55 #include "bgpd/bgp_keepalives.h"
56 #include "bgpd/bgp_io.h"
57 #include "bgpd/bgp_zebra.h"
58
59 DEFINE_HOOK(peer_backward_transition, (struct peer * peer), (peer))
60 DEFINE_HOOK(peer_established, (struct peer * peer), (peer))
61
62 /* Definition of display strings corresponding to FSM events. This should be
63 * kept consistent with the events defined in bgpd.h
64 */
65 static const char *bgp_event_str[] = {
66 NULL,
67 "BGP_Start",
68 "BGP_Stop",
69 "TCP_connection_open",
70 "TCP_connection_closed",
71 "TCP_connection_open_failed",
72 "TCP_fatal_error",
73 "ConnectRetry_timer_expired",
74 "Hold_Timer_expired",
75 "KeepAlive_timer_expired",
76 "Receive_OPEN_message",
77 "Receive_KEEPALIVE_message",
78 "Receive_UPDATE_message",
79 "Receive_NOTIFICATION_message",
80 "Clearing_Completed",
81 };
82
83 /* BGP FSM (finite state machine) has three types of functions. Type
84 one is thread functions. Type two is event functions. Type three
85 is FSM functions. Timer functions are set by bgp_timer_set
86 function. */
87
88 /* BGP event function. */
89 int bgp_event(struct thread *);
90
91 /* BGP thread functions. */
92 static int bgp_start_timer(struct thread *);
93 static int bgp_connect_timer(struct thread *);
94 static int bgp_holdtime_timer(struct thread *);
95
96 /* BGP FSM functions. */
97 static int bgp_start(struct peer *);
98
99 static void peer_xfer_stats(struct peer *peer_dst, struct peer *peer_src)
100 {
101 /* Copy stats over. These are only the pre-established state stats */
102 peer_dst->open_in += peer_src->open_in;
103 peer_dst->open_out += peer_src->open_out;
104 peer_dst->keepalive_in += peer_src->keepalive_in;
105 peer_dst->keepalive_out += peer_src->keepalive_out;
106 peer_dst->notify_in += peer_src->notify_in;
107 peer_dst->notify_out += peer_src->notify_out;
108 peer_dst->dynamic_cap_in += peer_src->dynamic_cap_in;
109 peer_dst->dynamic_cap_out += peer_src->dynamic_cap_out;
110 }
111
112 static struct peer *peer_xfer_conn(struct peer *from_peer)
113 {
114 struct peer *peer;
115 afi_t afi;
116 safi_t safi;
117 int fd;
118 int status, pstatus;
119 unsigned char last_evt, last_maj_evt;
120
121 assert(from_peer != NULL);
122
123 peer = from_peer->doppelganger;
124
125 if (!peer || !CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
126 return from_peer;
127
128 /*
129 * Let's check that we are not going to loose known configuration
130 * state based upon doppelganger rules.
131 */
132 FOREACH_AFI_SAFI (afi, safi) {
133 if (from_peer->afc[afi][safi] != peer->afc[afi][safi]) {
134 flog_err(
135 EC_BGP_DOPPELGANGER_CONFIG,
136 "from_peer->afc[%d][%d] is not the same as what we are overwriting",
137 afi, safi);
138 return NULL;
139 }
140 }
141
142 if (bgp_debug_neighbor_events(peer))
143 zlog_debug("%s: peer transfer %p fd %d -> %p fd %d)",
144 from_peer->host, from_peer, from_peer->fd, peer,
145 peer->fd);
146
147 bgp_writes_off(peer);
148 bgp_reads_off(peer);
149 bgp_writes_off(from_peer);
150 bgp_reads_off(from_peer);
151
152 BGP_TIMER_OFF(peer->t_routeadv);
153 BGP_TIMER_OFF(peer->t_connect);
154 BGP_TIMER_OFF(peer->t_connect_check_r);
155 BGP_TIMER_OFF(peer->t_connect_check_w);
156 BGP_TIMER_OFF(from_peer->t_routeadv);
157 BGP_TIMER_OFF(from_peer->t_connect);
158 BGP_TIMER_OFF(from_peer->t_connect_check_r);
159 BGP_TIMER_OFF(from_peer->t_connect_check_w);
160 BGP_TIMER_OFF(from_peer->t_process_packet);
161
162 /*
163 * At this point in time, it is possible that there are packets pending
164 * on various buffers. Those need to be transferred or dropped,
165 * otherwise we'll get spurious failures during session establishment.
166 */
167 pthread_mutex_lock(&peer->io_mtx);
168 pthread_mutex_lock(&from_peer->io_mtx);
169 {
170 fd = peer->fd;
171 peer->fd = from_peer->fd;
172 from_peer->fd = fd;
173
174 stream_fifo_clean(peer->ibuf);
175 stream_fifo_clean(peer->obuf);
176
177 /*
178 * this should never happen, since bgp_process_packet() is the
179 * only task that sets and unsets the current packet and it
180 * runs in our pthread.
181 */
182 if (peer->curr) {
183 flog_err(
184 EC_BGP_PKT_PROCESS,
185 "[%s] Dropping pending packet on connection transfer:",
186 peer->host);
187 uint16_t type = stream_getc_from(peer->curr,
188 BGP_MARKER_SIZE + 2);
189 bgp_dump_packet(peer, type, peer->curr);
190 stream_free(peer->curr);
191 peer->curr = NULL;
192 }
193
194 // copy each packet from old peer's output queue to new peer
195 while (from_peer->obuf->head)
196 stream_fifo_push(peer->obuf,
197 stream_fifo_pop(from_peer->obuf));
198
199 // copy each packet from old peer's input queue to new peer
200 while (from_peer->ibuf->head)
201 stream_fifo_push(peer->ibuf,
202 stream_fifo_pop(from_peer->ibuf));
203
204 ringbuf_wipe(peer->ibuf_work);
205 ringbuf_copy(peer->ibuf_work, from_peer->ibuf_work,
206 ringbuf_remain(from_peer->ibuf_work));
207 }
208 pthread_mutex_unlock(&from_peer->io_mtx);
209 pthread_mutex_unlock(&peer->io_mtx);
210
211 peer->as = from_peer->as;
212 peer->v_holdtime = from_peer->v_holdtime;
213 peer->v_keepalive = from_peer->v_keepalive;
214 peer->v_routeadv = from_peer->v_routeadv;
215 peer->v_gr_restart = from_peer->v_gr_restart;
216 peer->cap = from_peer->cap;
217 status = peer->status;
218 pstatus = peer->ostatus;
219 last_evt = peer->last_event;
220 last_maj_evt = peer->last_major_event;
221 peer->status = from_peer->status;
222 peer->ostatus = from_peer->ostatus;
223 peer->last_event = from_peer->last_event;
224 peer->last_major_event = from_peer->last_major_event;
225 from_peer->status = status;
226 from_peer->ostatus = pstatus;
227 from_peer->last_event = last_evt;
228 from_peer->last_major_event = last_maj_evt;
229 peer->remote_id = from_peer->remote_id;
230
231 if (from_peer->hostname != NULL) {
232 if (peer->hostname) {
233 XFREE(MTYPE_BGP_PEER_HOST, peer->hostname);
234 peer->hostname = NULL;
235 }
236
237 peer->hostname = from_peer->hostname;
238 from_peer->hostname = NULL;
239 }
240
241 if (from_peer->domainname != NULL) {
242 if (peer->domainname) {
243 XFREE(MTYPE_BGP_PEER_HOST, peer->domainname);
244 peer->domainname = NULL;
245 }
246
247 peer->domainname = from_peer->domainname;
248 from_peer->domainname = NULL;
249 }
250
251 FOREACH_AFI_SAFI (afi, safi) {
252 peer->af_flags[afi][safi] = from_peer->af_flags[afi][safi];
253 peer->af_sflags[afi][safi] = from_peer->af_sflags[afi][safi];
254 peer->af_cap[afi][safi] = from_peer->af_cap[afi][safi];
255 peer->afc_nego[afi][safi] = from_peer->afc_nego[afi][safi];
256 peer->afc_adv[afi][safi] = from_peer->afc_adv[afi][safi];
257 peer->afc_recv[afi][safi] = from_peer->afc_recv[afi][safi];
258 peer->orf_plist[afi][safi] = from_peer->orf_plist[afi][safi];
259 }
260
261 if (bgp_getsockname(peer) < 0) {
262 flog_err(
263 EC_LIB_SOCKET,
264 "%%bgp_getsockname() failed for %s peer %s fd %d (from_peer fd %d)",
265 (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)
266 ? "accept"
267 : ""),
268 peer->host, peer->fd, from_peer->fd);
269 bgp_stop(peer);
270 bgp_stop(from_peer);
271 return NULL;
272 }
273 if (from_peer->status > Active) {
274 if (bgp_getsockname(from_peer) < 0) {
275 flog_err(
276 EC_LIB_SOCKET,
277 "%%bgp_getsockname() failed for %s from_peer %s fd %d (peer fd %d)",
278
279 (CHECK_FLAG(from_peer->sflags,
280 PEER_STATUS_ACCEPT_PEER)
281 ? "accept"
282 : ""),
283 from_peer->host, from_peer->fd, peer->fd);
284 bgp_stop(from_peer);
285 from_peer = NULL;
286 }
287 }
288
289
290 // Note: peer_xfer_stats() must be called with I/O turned OFF
291 if (from_peer)
292 peer_xfer_stats(peer, from_peer);
293
294 bgp_reads_on(peer);
295 bgp_writes_on(peer);
296 thread_add_timer_msec(bm->master, bgp_process_packet, peer, 0,
297 &peer->t_process_packet);
298
299 return (peer);
300 }
301
302 /* Hook function called after bgp event is occered. And vty's
303 neighbor command invoke this function after making neighbor
304 structure. */
305 void bgp_timer_set(struct peer *peer)
306 {
307 switch (peer->status) {
308 case Idle:
309 /* First entry point of peer's finite state machine. In Idle
310 status start timer is on unless peer is shutdown or peer is
311 inactive. All other timer must be turned off */
312 if (BGP_PEER_START_SUPPRESSED(peer) || !peer_active(peer)
313 || peer->bgp->vrf_id == VRF_UNKNOWN) {
314 BGP_TIMER_OFF(peer->t_start);
315 } else {
316 BGP_TIMER_ON(peer->t_start, bgp_start_timer,
317 peer->v_start);
318 }
319 BGP_TIMER_OFF(peer->t_connect);
320 BGP_TIMER_OFF(peer->t_holdtime);
321 bgp_keepalives_off(peer);
322 BGP_TIMER_OFF(peer->t_routeadv);
323 break;
324
325 case Connect:
326 /* After start timer is expired, the peer moves to Connect
327 status. Make sure start timer is off and connect timer is
328 on. */
329 BGP_TIMER_OFF(peer->t_start);
330 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
331 peer->v_connect);
332 BGP_TIMER_OFF(peer->t_holdtime);
333 bgp_keepalives_off(peer);
334 BGP_TIMER_OFF(peer->t_routeadv);
335 break;
336
337 case Active:
338 /* Active is waiting connection from remote peer. And if
339 connect timer is expired, change status to Connect. */
340 BGP_TIMER_OFF(peer->t_start);
341 /* If peer is passive mode, do not set connect timer. */
342 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)
343 || CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
344 BGP_TIMER_OFF(peer->t_connect);
345 } else {
346 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
347 peer->v_connect);
348 }
349 BGP_TIMER_OFF(peer->t_holdtime);
350 bgp_keepalives_off(peer);
351 BGP_TIMER_OFF(peer->t_routeadv);
352 break;
353
354 case OpenSent:
355 /* OpenSent status. */
356 BGP_TIMER_OFF(peer->t_start);
357 BGP_TIMER_OFF(peer->t_connect);
358 if (peer->v_holdtime != 0) {
359 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
360 peer->v_holdtime);
361 } else {
362 BGP_TIMER_OFF(peer->t_holdtime);
363 }
364 bgp_keepalives_off(peer);
365 BGP_TIMER_OFF(peer->t_routeadv);
366 break;
367
368 case OpenConfirm:
369 /* OpenConfirm status. */
370 BGP_TIMER_OFF(peer->t_start);
371 BGP_TIMER_OFF(peer->t_connect);
372
373 /* If the negotiated Hold Time value is zero, then the Hold Time
374 timer and KeepAlive timers are not started. */
375 if (peer->v_holdtime == 0) {
376 BGP_TIMER_OFF(peer->t_holdtime);
377 bgp_keepalives_off(peer);
378 } else {
379 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
380 peer->v_holdtime);
381 bgp_keepalives_on(peer);
382 }
383 BGP_TIMER_OFF(peer->t_routeadv);
384 break;
385
386 case Established:
387 /* In Established status start and connect timer is turned
388 off. */
389 BGP_TIMER_OFF(peer->t_start);
390 BGP_TIMER_OFF(peer->t_connect);
391
392 /* Same as OpenConfirm, if holdtime is zero then both holdtime
393 and keepalive must be turned off. */
394 if (peer->v_holdtime == 0) {
395 BGP_TIMER_OFF(peer->t_holdtime);
396 bgp_keepalives_off(peer);
397 } else {
398 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
399 peer->v_holdtime);
400 bgp_keepalives_on(peer);
401 }
402 break;
403 case Deleted:
404 BGP_TIMER_OFF(peer->t_gr_restart);
405 BGP_TIMER_OFF(peer->t_gr_stale);
406 BGP_TIMER_OFF(peer->t_pmax_restart);
407 /* fallthru */
408 case Clearing:
409 BGP_TIMER_OFF(peer->t_start);
410 BGP_TIMER_OFF(peer->t_connect);
411 BGP_TIMER_OFF(peer->t_holdtime);
412 bgp_keepalives_off(peer);
413 BGP_TIMER_OFF(peer->t_routeadv);
414 break;
415 }
416 }
417
418 /* BGP start timer. This function set BGP_Start event to thread value
419 and process event. */
420 static int bgp_start_timer(struct thread *thread)
421 {
422 struct peer *peer;
423
424 peer = THREAD_ARG(thread);
425 peer->t_start = NULL;
426
427 if (bgp_debug_neighbor_events(peer))
428 zlog_debug("%s [FSM] Timer (start timer expire).", peer->host);
429
430 THREAD_VAL(thread) = BGP_Start;
431 bgp_event(thread); /* bgp_event unlocks peer */
432
433 return 0;
434 }
435
436 /* BGP connect retry timer. */
437 static int bgp_connect_timer(struct thread *thread)
438 {
439 struct peer *peer;
440 int ret;
441
442 peer = THREAD_ARG(thread);
443
444 assert(!peer->t_write);
445 assert(!peer->t_read);
446
447 peer->t_connect = NULL;
448
449 if (bgp_debug_neighbor_events(peer))
450 zlog_debug("%s [FSM] Timer (connect timer expire)", peer->host);
451
452 if (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) {
453 bgp_stop(peer);
454 ret = -1;
455 } else {
456 THREAD_VAL(thread) = ConnectRetry_timer_expired;
457 bgp_event(thread); /* bgp_event unlocks peer */
458 ret = 0;
459 }
460
461 return ret;
462 }
463
464 /* BGP holdtime timer. */
465 static int bgp_holdtime_timer(struct thread *thread)
466 {
467 struct peer *peer;
468
469 peer = THREAD_ARG(thread);
470 peer->t_holdtime = NULL;
471
472 if (bgp_debug_neighbor_events(peer))
473 zlog_debug("%s [FSM] Timer (holdtime timer expire)",
474 peer->host);
475
476 THREAD_VAL(thread) = Hold_Timer_expired;
477 bgp_event(thread); /* bgp_event unlocks peer */
478
479 return 0;
480 }
481
482 int bgp_routeadv_timer(struct thread *thread)
483 {
484 struct peer *peer;
485
486 peer = THREAD_ARG(thread);
487 peer->t_routeadv = NULL;
488
489 if (bgp_debug_neighbor_events(peer))
490 zlog_debug("%s [FSM] Timer (routeadv timer expire)",
491 peer->host);
492
493 peer->synctime = bgp_clock();
494
495 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets, peer, 0,
496 &peer->t_generate_updgrp_packets);
497
498 /* MRAI timer will be started again when FIFO is built, no need to
499 * do it here.
500 */
501 return 0;
502 }
503
504 /* BGP Peer Down Cause */
505 const char *peer_down_str[] = {"",
506 "Router ID changed",
507 "Remote AS changed",
508 "Local AS change",
509 "Cluster ID changed",
510 "Confederation identifier changed",
511 "Confederation peer changed",
512 "RR client config change",
513 "RS client config change",
514 "Update source change",
515 "Address family activated",
516 "Admin. shutdown",
517 "User reset",
518 "BGP Notification received",
519 "BGP Notification send",
520 "Peer closed the session",
521 "Neighbor deleted",
522 "Peer-group add member",
523 "Peer-group delete member",
524 "Capability changed",
525 "Passive config change",
526 "Multihop config change",
527 "NSF peer closed the session",
528 "Intf peering v6only config change",
529 "BFD down received",
530 "Interface down",
531 "Neighbor address lost"};
532
533 static int bgp_graceful_restart_timer_expire(struct thread *thread)
534 {
535 struct peer *peer;
536 afi_t afi;
537 safi_t safi;
538
539 peer = THREAD_ARG(thread);
540 peer->t_gr_restart = NULL;
541
542 /* NSF delete stale route */
543 for (afi = AFI_IP; afi < AFI_MAX; afi++)
544 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
545 if (peer->nsf[afi][safi])
546 bgp_clear_stale_route(peer, afi, safi);
547
548 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
549 BGP_TIMER_OFF(peer->t_gr_stale);
550
551 if (bgp_debug_neighbor_events(peer)) {
552 zlog_debug("%s graceful restart timer expired", peer->host);
553 zlog_debug("%s graceful restart stalepath timer stopped",
554 peer->host);
555 }
556
557 bgp_timer_set(peer);
558
559 return 0;
560 }
561
562 static int bgp_graceful_stale_timer_expire(struct thread *thread)
563 {
564 struct peer *peer;
565 afi_t afi;
566 safi_t safi;
567
568 peer = THREAD_ARG(thread);
569 peer->t_gr_stale = NULL;
570
571 if (bgp_debug_neighbor_events(peer))
572 zlog_debug("%s graceful restart stalepath timer expired",
573 peer->host);
574
575 /* NSF delete stale route */
576 for (afi = AFI_IP; afi < AFI_MAX; afi++)
577 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
578 if (peer->nsf[afi][safi])
579 bgp_clear_stale_route(peer, afi, safi);
580
581 return 0;
582 }
583
584 static int bgp_update_delay_applicable(struct bgp *bgp)
585 {
586 /* update_delay_over flag should be reset (set to 0) for any new
587 applicability of the update-delay during BGP process lifetime.
588 And it should be set after an occurence of the update-delay is
589 over)*/
590 if (!bgp->update_delay_over)
591 return 1;
592
593 return 0;
594 }
595
596 int bgp_update_delay_active(struct bgp *bgp)
597 {
598 if (bgp->t_update_delay)
599 return 1;
600
601 return 0;
602 }
603
604 int bgp_update_delay_configured(struct bgp *bgp)
605 {
606 if (bgp->v_update_delay)
607 return 1;
608
609 return 0;
610 }
611
612 /* Do the post-processing needed when bgp comes out of the read-only mode
613 on ending the update delay. */
614 void bgp_update_delay_end(struct bgp *bgp)
615 {
616 THREAD_TIMER_OFF(bgp->t_update_delay);
617 THREAD_TIMER_OFF(bgp->t_establish_wait);
618
619 /* Reset update-delay related state */
620 bgp->update_delay_over = 1;
621 bgp->established = 0;
622 bgp->restarted_peers = 0;
623 bgp->implicit_eors = 0;
624 bgp->explicit_eors = 0;
625
626 quagga_timestamp(3, bgp->update_delay_end_time,
627 sizeof(bgp->update_delay_end_time));
628
629 /*
630 * Add an end-of-initial-update marker to the main process queues so
631 * that
632 * the route advertisement timer for the peers can be started. Also set
633 * the zebra and peer update hold flags. These flags are used to achieve
634 * three stages in the update-delay post processing:
635 * 1. Finish best-path selection for all the prefixes held on the
636 * queues.
637 * (routes in BGP are updated, and peers sync queues are populated
638 * too)
639 * 2. As the eoiu mark is reached in the bgp process routine, ship all
640 * the
641 * routes to zebra. With that zebra should see updates from BGP
642 * close
643 * to each other.
644 * 3. Unblock the peer update writes. With that peer update packing
645 * with
646 * the prefixes should be at its maximum.
647 */
648 bgp_add_eoiu_mark(bgp);
649 bgp->main_zebra_update_hold = 1;
650 bgp->main_peers_update_hold = 1;
651
652 /* Resume the queue processing. This should trigger the event that would
653 take
654 care of processing any work that was queued during the read-only
655 mode. */
656 work_queue_unplug(bm->process_main_queue);
657 }
658
659 /**
660 * see bgp_fsm.h
661 */
662 void bgp_start_routeadv(struct bgp *bgp)
663 {
664 struct listnode *node, *nnode;
665 struct peer *peer;
666
667 zlog_info("bgp_start_routeadv(), update hold status %d",
668 bgp->main_peers_update_hold);
669
670 if (bgp->main_peers_update_hold)
671 return;
672
673 quagga_timestamp(3, bgp->update_delay_peers_resume_time,
674 sizeof(bgp->update_delay_peers_resume_time));
675
676 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
677 if (peer->status != Established)
678 continue;
679 BGP_TIMER_OFF(peer->t_routeadv);
680 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
681 }
682 }
683
684 /**
685 * see bgp_fsm.h
686 */
687 void bgp_adjust_routeadv(struct peer *peer)
688 {
689 time_t nowtime = bgp_clock();
690 double diff;
691 unsigned long remain;
692
693 /* Bypass checks for special case of MRAI being 0 */
694 if (peer->v_routeadv == 0) {
695 /* Stop existing timer, just in case it is running for a
696 * different
697 * duration and schedule write thread immediately.
698 */
699 if (peer->t_routeadv)
700 BGP_TIMER_OFF(peer->t_routeadv);
701
702 peer->synctime = bgp_clock();
703 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets,
704 peer, 0,
705 &peer->t_generate_updgrp_packets);
706 return;
707 }
708
709
710 /*
711 * CASE I:
712 * If the last update was written more than MRAI back, expire the timer
713 * instantly so that we can send the update out sooner.
714 *
715 * <------- MRAI --------->
716 * |-----------------|-----------------------|
717 * <------------- m ------------>
718 * ^ ^ ^
719 * | | |
720 * | | current time
721 * | timer start
722 * last write
723 *
724 * m > MRAI
725 */
726 diff = difftime(nowtime, peer->last_update);
727 if (diff > (double)peer->v_routeadv) {
728 BGP_TIMER_OFF(peer->t_routeadv);
729 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
730 return;
731 }
732
733 /*
734 * CASE II:
735 * - Find when to expire the MRAI timer.
736 * If MRAI timer is not active, assume we can start it now.
737 *
738 * <------- MRAI --------->
739 * |------------|-----------------------|
740 * <-------- m ----------><----- r ----->
741 * ^ ^ ^
742 * | | |
743 * | | current time
744 * | timer start
745 * last write
746 *
747 * (MRAI - m) < r
748 */
749 if (peer->t_routeadv)
750 remain = thread_timer_remain_second(peer->t_routeadv);
751 else
752 remain = peer->v_routeadv;
753 diff = peer->v_routeadv - diff;
754 if (diff <= (double)remain) {
755 BGP_TIMER_OFF(peer->t_routeadv);
756 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, diff);
757 }
758 }
759
760 static int bgp_maxmed_onstartup_applicable(struct bgp *bgp)
761 {
762 if (!bgp->maxmed_onstartup_over)
763 return 1;
764
765 return 0;
766 }
767
768 int bgp_maxmed_onstartup_configured(struct bgp *bgp)
769 {
770 if (bgp->v_maxmed_onstartup != BGP_MAXMED_ONSTARTUP_UNCONFIGURED)
771 return 1;
772
773 return 0;
774 }
775
776 int bgp_maxmed_onstartup_active(struct bgp *bgp)
777 {
778 if (bgp->t_maxmed_onstartup)
779 return 1;
780
781 return 0;
782 }
783
784 void bgp_maxmed_update(struct bgp *bgp)
785 {
786 uint8_t maxmed_active;
787 uint32_t maxmed_value;
788
789 if (bgp->v_maxmed_admin) {
790 maxmed_active = 1;
791 maxmed_value = bgp->maxmed_admin_value;
792 } else if (bgp->t_maxmed_onstartup) {
793 maxmed_active = 1;
794 maxmed_value = bgp->maxmed_onstartup_value;
795 } else {
796 maxmed_active = 0;
797 maxmed_value = BGP_MAXMED_VALUE_DEFAULT;
798 }
799
800 if (bgp->maxmed_active != maxmed_active
801 || bgp->maxmed_value != maxmed_value) {
802 bgp->maxmed_active = maxmed_active;
803 bgp->maxmed_value = maxmed_value;
804
805 update_group_announce(bgp);
806 }
807 }
808
809 /* The maxmed onstartup timer expiry callback. */
810 static int bgp_maxmed_onstartup_timer(struct thread *thread)
811 {
812 struct bgp *bgp;
813
814 zlog_info("Max med on startup ended - timer expired.");
815
816 bgp = THREAD_ARG(thread);
817 THREAD_TIMER_OFF(bgp->t_maxmed_onstartup);
818 bgp->maxmed_onstartup_over = 1;
819
820 bgp_maxmed_update(bgp);
821
822 return 0;
823 }
824
825 static void bgp_maxmed_onstartup_begin(struct bgp *bgp)
826 {
827 /* Applicable only once in the process lifetime on the startup */
828 if (bgp->maxmed_onstartup_over)
829 return;
830
831 zlog_info("Begin maxmed onstartup mode - timer %d seconds",
832 bgp->v_maxmed_onstartup);
833
834 thread_add_timer(bm->master, bgp_maxmed_onstartup_timer, bgp,
835 bgp->v_maxmed_onstartup, &bgp->t_maxmed_onstartup);
836
837 if (!bgp->v_maxmed_admin) {
838 bgp->maxmed_active = 1;
839 bgp->maxmed_value = bgp->maxmed_onstartup_value;
840 }
841
842 /* Route announce to all peers should happen after this in
843 * bgp_establish() */
844 }
845
846 static void bgp_maxmed_onstartup_process_status_change(struct peer *peer)
847 {
848 if (peer->status == Established && !peer->bgp->established) {
849 bgp_maxmed_onstartup_begin(peer->bgp);
850 }
851 }
852
853 /* The update delay timer expiry callback. */
854 static int bgp_update_delay_timer(struct thread *thread)
855 {
856 struct bgp *bgp;
857
858 zlog_info("Update delay ended - timer expired.");
859
860 bgp = THREAD_ARG(thread);
861 THREAD_TIMER_OFF(bgp->t_update_delay);
862 bgp_update_delay_end(bgp);
863
864 return 0;
865 }
866
867 /* The establish wait timer expiry callback. */
868 static int bgp_establish_wait_timer(struct thread *thread)
869 {
870 struct bgp *bgp;
871
872 zlog_info("Establish wait - timer expired.");
873
874 bgp = THREAD_ARG(thread);
875 THREAD_TIMER_OFF(bgp->t_establish_wait);
876 bgp_check_update_delay(bgp);
877
878 return 0;
879 }
880
881 /* Steps to begin the update delay:
882 - initialize queues if needed
883 - stop the queue processing
884 - start the timer */
885 static void bgp_update_delay_begin(struct bgp *bgp)
886 {
887 struct listnode *node, *nnode;
888 struct peer *peer;
889
890 /* Stop the processing of queued work. Enqueue shall continue */
891 work_queue_plug(bm->process_main_queue);
892
893 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer))
894 peer->update_delay_over = 0;
895
896 /* Start the update-delay timer */
897 thread_add_timer(bm->master, bgp_update_delay_timer, bgp,
898 bgp->v_update_delay, &bgp->t_update_delay);
899
900 if (bgp->v_establish_wait != bgp->v_update_delay)
901 thread_add_timer(bm->master, bgp_establish_wait_timer, bgp,
902 bgp->v_establish_wait, &bgp->t_establish_wait);
903
904 quagga_timestamp(3, bgp->update_delay_begin_time,
905 sizeof(bgp->update_delay_begin_time));
906 }
907
908 static void bgp_update_delay_process_status_change(struct peer *peer)
909 {
910 if (peer->status == Established) {
911 if (!peer->bgp->established++) {
912 bgp_update_delay_begin(peer->bgp);
913 zlog_info(
914 "Begin read-only mode - update-delay timer %d seconds",
915 peer->bgp->v_update_delay);
916 }
917 if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_BIT_RCV))
918 bgp_update_restarted_peers(peer);
919 }
920 if (peer->ostatus == Established
921 && bgp_update_delay_active(peer->bgp)) {
922 /* Adjust the update-delay state to account for this flap.
923 NOTE: Intentionally skipping adjusting implicit_eors or
924 explicit_eors
925 counters. Extra sanity check in bgp_check_update_delay()
926 should
927 be enough to take care of any additive discrepancy in bgp eor
928 counters */
929 peer->bgp->established--;
930 peer->update_delay_over = 0;
931 }
932 }
933
934 /* Called after event occurred, this function change status and reset
935 read/write and timer thread. */
936 void bgp_fsm_change_status(struct peer *peer, int status)
937 {
938
939 bgp_dump_state(peer, peer->status, status);
940
941 /* Transition into Clearing or Deleted must /always/ clear all routes..
942 * (and must do so before actually changing into Deleted..
943 */
944 if (status >= Clearing) {
945 bgp_clear_route_all(peer);
946
947 /* If no route was queued for the clear-node processing,
948 * generate the
949 * completion event here. This is needed because if there are no
950 * routes
951 * to trigger the background clear-node thread, the event won't
952 * get
953 * generated and the peer would be stuck in Clearing. Note that
954 * this
955 * event is for the peer and helps the peer transition out of
956 * Clearing
957 * state; it should not be generated per (AFI,SAFI). The event
958 * is
959 * directly posted here without calling clear_node_complete() as
960 * we
961 * shouldn't do an extra unlock. This event will get processed
962 * after
963 * the state change that happens below, so peer will be in
964 * Clearing
965 * (or Deleted).
966 */
967 if (!work_queue_is_scheduled(peer->clear_node_queue))
968 BGP_EVENT_ADD(peer, Clearing_Completed);
969 }
970
971 /* Preserve old status and change into new status. */
972 peer->ostatus = peer->status;
973 peer->status = status;
974
975 /* Save event that caused status change. */
976 peer->last_major_event = peer->cur_event;
977
978 if (status == Established)
979 UNSET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER);
980
981 /* If max-med processing is applicable, do the necessary. */
982 if (status == Established) {
983 if (bgp_maxmed_onstartup_configured(peer->bgp)
984 && bgp_maxmed_onstartup_applicable(peer->bgp))
985 bgp_maxmed_onstartup_process_status_change(peer);
986 else
987 peer->bgp->maxmed_onstartup_over = 1;
988 }
989
990 /* If update-delay processing is applicable, do the necessary. */
991 if (bgp_update_delay_configured(peer->bgp)
992 && bgp_update_delay_applicable(peer->bgp))
993 bgp_update_delay_process_status_change(peer);
994
995 if (bgp_debug_neighbor_events(peer))
996 zlog_debug("%s went from %s to %s", peer->host,
997 lookup_msg(bgp_status_msg, peer->ostatus, NULL),
998 lookup_msg(bgp_status_msg, peer->status, NULL));
999 }
1000
1001 /* Flush the event queue and ensure the peer is shut down */
1002 static int bgp_clearing_completed(struct peer *peer)
1003 {
1004 int rc = bgp_stop(peer);
1005
1006 if (rc >= 0)
1007 BGP_EVENT_FLUSH(peer);
1008
1009 return rc;
1010 }
1011
1012 /* Administrative BGP peer stop event. */
1013 /* May be called multiple times for the same peer */
1014 int bgp_stop(struct peer *peer)
1015 {
1016 afi_t afi;
1017 safi_t safi;
1018 char orf_name[BUFSIZ];
1019 int ret = 0;
1020
1021 if (peer_dynamic_neighbor(peer)
1022 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1023 if (bgp_debug_neighbor_events(peer))
1024 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1025 peer_delete(peer);
1026 return -1;
1027 }
1028
1029 /* Can't do this in Clearing; events are used for state transitions */
1030 if (peer->status != Clearing) {
1031 /* Delete all existing events of the peer */
1032 BGP_EVENT_FLUSH(peer);
1033 }
1034
1035 /* Increment Dropped count. */
1036 if (peer->status == Established) {
1037 peer->dropped++;
1038
1039 /* bgp log-neighbor-changes of neighbor Down */
1040 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1041 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1042 zlog_info(
1043 "%%ADJCHANGE: neighbor %s(%s) in vrf %s Down %s",
1044 peer->host,
1045 (peer->hostname) ? peer->hostname : "Unknown",
1046 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1047 ? vrf->name
1048 : VRF_DEFAULT_NAME)
1049 : "",
1050 peer_down_str[(int)peer->last_reset]);
1051 }
1052
1053 /* graceful restart */
1054 if (peer->t_gr_stale) {
1055 BGP_TIMER_OFF(peer->t_gr_stale);
1056 if (bgp_debug_neighbor_events(peer))
1057 zlog_debug(
1058 "%s graceful restart stalepath timer stopped",
1059 peer->host);
1060 }
1061 if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
1062 if (bgp_debug_neighbor_events(peer)) {
1063 zlog_debug(
1064 "%s graceful restart timer started for %d sec",
1065 peer->host, peer->v_gr_restart);
1066 zlog_debug(
1067 "%s graceful restart stalepath timer started for %d sec",
1068 peer->host, peer->bgp->stalepath_time);
1069 }
1070 BGP_TIMER_ON(peer->t_gr_restart,
1071 bgp_graceful_restart_timer_expire,
1072 peer->v_gr_restart);
1073 BGP_TIMER_ON(peer->t_gr_stale,
1074 bgp_graceful_stale_timer_expire,
1075 peer->bgp->stalepath_time);
1076 } else {
1077 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1078
1079 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1080 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN;
1081 safi++)
1082 peer->nsf[afi][safi] = 0;
1083 }
1084
1085 /* set last reset time */
1086 peer->resettime = peer->uptime = bgp_clock();
1087
1088 if (BGP_DEBUG(update_groups, UPDATE_GROUPS))
1089 zlog_debug("%s remove from all update group",
1090 peer->host);
1091 update_group_remove_peer_afs(peer);
1092
1093 hook_call(peer_backward_transition, peer);
1094
1095 /* Reset peer synctime */
1096 peer->synctime = 0;
1097
1098 bgp_bfd_deregister_peer(peer);
1099 }
1100
1101 /* stop keepalives */
1102 bgp_keepalives_off(peer);
1103
1104 /* Stop read and write threads. */
1105 bgp_writes_off(peer);
1106 bgp_reads_off(peer);
1107
1108 THREAD_OFF(peer->t_connect_check_r);
1109 THREAD_OFF(peer->t_connect_check_w);
1110
1111 /* Stop all timers. */
1112 BGP_TIMER_OFF(peer->t_start);
1113 BGP_TIMER_OFF(peer->t_connect);
1114 BGP_TIMER_OFF(peer->t_holdtime);
1115 BGP_TIMER_OFF(peer->t_routeadv);
1116
1117 /* Clear input and output buffer. */
1118 pthread_mutex_lock(&peer->io_mtx);
1119 {
1120 if (peer->ibuf)
1121 stream_fifo_clean(peer->ibuf);
1122 if (peer->obuf)
1123 stream_fifo_clean(peer->obuf);
1124
1125 if (peer->ibuf_work)
1126 ringbuf_wipe(peer->ibuf_work);
1127 if (peer->obuf_work)
1128 stream_reset(peer->obuf_work);
1129
1130 if (peer->curr) {
1131 stream_free(peer->curr);
1132 peer->curr = NULL;
1133 }
1134 }
1135 pthread_mutex_unlock(&peer->io_mtx);
1136
1137 /* Close of file descriptor. */
1138 if (peer->fd >= 0) {
1139 close(peer->fd);
1140 peer->fd = -1;
1141 }
1142
1143 FOREACH_AFI_SAFI (afi, safi) {
1144 /* Reset all negotiated variables */
1145 peer->afc_nego[afi][safi] = 0;
1146 peer->afc_adv[afi][safi] = 0;
1147 peer->afc_recv[afi][safi] = 0;
1148
1149 /* peer address family capability flags*/
1150 peer->af_cap[afi][safi] = 0;
1151
1152 /* peer address family status flags*/
1153 peer->af_sflags[afi][safi] = 0;
1154
1155 /* Received ORF prefix-filter */
1156 peer->orf_plist[afi][safi] = NULL;
1157
1158 if ((peer->status == OpenConfirm)
1159 || (peer->status == Established)) {
1160 /* ORF received prefix-filter pnt */
1161 sprintf(orf_name, "%s.%d.%d", peer->host, afi, safi);
1162 prefix_bgp_orf_remove_all(afi, orf_name);
1163 }
1164 }
1165
1166 /* Reset keepalive and holdtime */
1167 if (CHECK_FLAG(peer->flags, PEER_FLAG_TIMER)) {
1168 peer->v_keepalive = peer->keepalive;
1169 peer->v_holdtime = peer->holdtime;
1170 } else {
1171 peer->v_keepalive = peer->bgp->default_keepalive;
1172 peer->v_holdtime = peer->bgp->default_holdtime;
1173 }
1174
1175 peer->update_time = 0;
1176
1177 /* Until we are sure that there is no problem about prefix count
1178 this should be commented out.*/
1179 #if 0
1180 /* Reset prefix count */
1181 peer->pcount[AFI_IP][SAFI_UNICAST] = 0;
1182 peer->pcount[AFI_IP][SAFI_MULTICAST] = 0;
1183 peer->pcount[AFI_IP][SAFI_LABELED_UNICAST] = 0;
1184 peer->pcount[AFI_IP][SAFI_MPLS_VPN] = 0;
1185 peer->pcount[AFI_IP6][SAFI_UNICAST] = 0;
1186 peer->pcount[AFI_IP6][SAFI_MULTICAST] = 0;
1187 peer->pcount[AFI_IP6][SAFI_LABELED_UNICAST] = 0;
1188 #endif /* 0 */
1189
1190 if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE)
1191 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1192 peer_delete(peer);
1193 ret = -1;
1194 } else {
1195 bgp_peer_conf_if_to_su_update(peer);
1196 }
1197
1198 return ret;
1199 }
1200
1201 /* BGP peer is stoped by the error. */
1202 static int bgp_stop_with_error(struct peer *peer)
1203 {
1204 /* Double start timer. */
1205 peer->v_start *= 2;
1206
1207 /* Overflow check. */
1208 if (peer->v_start >= (60 * 2))
1209 peer->v_start = (60 * 2);
1210
1211 if (peer_dynamic_neighbor(peer)) {
1212 if (bgp_debug_neighbor_events(peer))
1213 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1214 peer_delete(peer);
1215 return -1;
1216 }
1217
1218 return (bgp_stop(peer));
1219 }
1220
1221
1222 /* something went wrong, send notify and tear down */
1223 static int bgp_stop_with_notify(struct peer *peer, uint8_t code,
1224 uint8_t sub_code)
1225 {
1226 /* Send notify to remote peer */
1227 bgp_notify_send(peer, code, sub_code);
1228
1229 if (peer_dynamic_neighbor(peer)) {
1230 if (bgp_debug_neighbor_events(peer))
1231 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1232 peer_delete(peer);
1233 return -1;
1234 }
1235
1236 /* Clear start timer value to default. */
1237 peer->v_start = BGP_INIT_START_TIMER;
1238
1239 return (bgp_stop(peer));
1240 }
1241
1242 /**
1243 * Determines whether a TCP session has successfully established for a peer and
1244 * events as appropriate.
1245 *
1246 * This function is called when setting up a new session. After connect() is
1247 * called on the peer's socket (in bgp_start()), the fd is passed to poll()
1248 * to wait for connection success or failure. When poll() returns, this
1249 * function is called to evaluate the result.
1250 *
1251 * Due to differences in behavior of poll() on Linux and BSD - specifically,
1252 * the value of .revents in the case of a closed connection - this function is
1253 * scheduled both for a read and a write event. The write event is triggered
1254 * when the connection is established. A read event is triggered when the
1255 * connection is closed. Thus we need to cancel whichever one did not occur.
1256 */
1257 static int bgp_connect_check(struct thread *thread)
1258 {
1259 int status;
1260 socklen_t slen;
1261 int ret;
1262 struct peer *peer;
1263
1264 peer = THREAD_ARG(thread);
1265 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1266 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1267 assert(!peer->t_read);
1268 assert(!peer->t_write);
1269
1270 THREAD_OFF(peer->t_connect_check_r);
1271 THREAD_OFF(peer->t_connect_check_w);
1272
1273 /* Check file descriptor. */
1274 slen = sizeof(status);
1275 ret = getsockopt(peer->fd, SOL_SOCKET, SO_ERROR, (void *)&status,
1276 &slen);
1277
1278 /* If getsockopt is fail, this is fatal error. */
1279 if (ret < 0) {
1280 zlog_info("can't get sockopt for nonblocking connect: %d(%s)",
1281 errno, safe_strerror(errno));
1282 BGP_EVENT_ADD(peer, TCP_fatal_error);
1283 return -1;
1284 }
1285
1286 /* When status is 0 then TCP connection is established. */
1287 if (status == 0) {
1288 BGP_EVENT_ADD(peer, TCP_connection_open);
1289 return 1;
1290 } else {
1291 if (bgp_debug_neighbor_events(peer))
1292 zlog_debug("%s [Event] Connect failed %d(%s)",
1293 peer->host, status, safe_strerror(status));
1294 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1295 return 0;
1296 }
1297 }
1298
1299 /* TCP connection open. Next we send open message to remote peer. And
1300 add read thread for reading open message. */
1301 static int bgp_connect_success(struct peer *peer)
1302 {
1303 if (peer->fd < 0) {
1304 flog_err(EC_BGP_CONNECT,
1305 "bgp_connect_success peer's fd is negative value %d",
1306 peer->fd);
1307 bgp_stop(peer);
1308 return -1;
1309 }
1310
1311 if (bgp_getsockname(peer) < 0) {
1312 flog_err_sys(EC_LIB_SOCKET,
1313 "%s: bgp_getsockname(): failed for peer %s, fd %d",
1314 __FUNCTION__, peer->host, peer->fd);
1315 bgp_notify_send(peer, BGP_NOTIFY_FSM_ERR,
1316 0); /* internal error */
1317 bgp_writes_on(peer);
1318 return -1;
1319 }
1320
1321 bgp_reads_on(peer);
1322
1323 if (bgp_debug_neighbor_events(peer)) {
1324 char buf1[SU_ADDRSTRLEN];
1325
1326 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER))
1327 zlog_debug("%s open active, local address %s",
1328 peer->host,
1329 sockunion2str(peer->su_local, buf1,
1330 SU_ADDRSTRLEN));
1331 else
1332 zlog_debug("%s passive open", peer->host);
1333 }
1334
1335 bgp_open_send(peer);
1336
1337 return 0;
1338 }
1339
1340 /* TCP connect fail */
1341 static int bgp_connect_fail(struct peer *peer)
1342 {
1343 if (peer_dynamic_neighbor(peer)) {
1344 if (bgp_debug_neighbor_events(peer))
1345 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1346 peer_delete(peer);
1347 return -1;
1348 }
1349
1350 return (bgp_stop(peer));
1351 }
1352
1353 /* This function is the first starting point of all BGP connection. It
1354 try to connect to remote peer with non-blocking IO. */
1355 int bgp_start(struct peer *peer)
1356 {
1357 int status;
1358 int connected = 0;
1359
1360 bgp_peer_conf_if_to_su_update(peer);
1361
1362 if (peer->su.sa.sa_family == AF_UNSPEC) {
1363 if (bgp_debug_neighbor_events(peer))
1364 zlog_debug(
1365 "%s [FSM] Unable to get neighbor's IP address, waiting...",
1366 peer->host);
1367 return -1;
1368 }
1369
1370 if (BGP_PEER_START_SUPPRESSED(peer)) {
1371 if (bgp_debug_neighbor_events(peer))
1372 flog_err(EC_BGP_FSM,
1373 "%s [FSM] Trying to start suppressed peer"
1374 " - this is never supposed to happen!",
1375 peer->host);
1376 return -1;
1377 }
1378
1379 /* Scrub some information that might be left over from a previous,
1380 * session
1381 */
1382 /* Connection information. */
1383 if (peer->su_local) {
1384 sockunion_free(peer->su_local);
1385 peer->su_local = NULL;
1386 }
1387
1388 if (peer->su_remote) {
1389 sockunion_free(peer->su_remote);
1390 peer->su_remote = NULL;
1391 }
1392
1393 /* Clear remote router-id. */
1394 peer->remote_id.s_addr = 0;
1395
1396 /* Clear peer capability flag. */
1397 peer->cap = 0;
1398
1399 /* If the peer is passive mode, force to move to Active mode. */
1400 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)) {
1401 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1402 return 0;
1403 }
1404
1405 if (peer->bgp->vrf_id == VRF_UNKNOWN) {
1406 if (bgp_debug_neighbor_events(peer))
1407 flog_err(
1408 EC_BGP_FSM,
1409 "%s [FSM] In a VRF that is not initialised yet",
1410 peer->host);
1411 return -1;
1412 }
1413
1414 /* Register to be notified on peer up */
1415 if (peer->sort == BGP_PEER_EBGP && peer->ttl == 1
1416 && !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
1417 && !bgp_flag_check(peer->bgp, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
1418 connected = 1;
1419 else
1420 connected = 0;
1421
1422 if (!bgp_find_or_add_nexthop(peer->bgp, peer->bgp,
1423 family2afi(peer->su.sa.sa_family), NULL,
1424 peer, connected)) {
1425 if (bgp_zebra_num_connects()) {
1426 if (bgp_debug_neighbor_events(peer))
1427 zlog_debug("%s [FSM] Waiting for NHT",
1428 peer->host);
1429
1430 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1431 return 0;
1432 }
1433 }
1434
1435 assert(!peer->t_write);
1436 assert(!peer->t_read);
1437 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1438 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1439 status = bgp_connect(peer);
1440
1441 switch (status) {
1442 case connect_error:
1443 if (bgp_debug_neighbor_events(peer))
1444 zlog_debug("%s [FSM] Connect error", peer->host);
1445 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1446 break;
1447 case connect_success:
1448 if (bgp_debug_neighbor_events(peer))
1449 zlog_debug(
1450 "%s [FSM] Connect immediately success, fd %d",
1451 peer->host, peer->fd);
1452 BGP_EVENT_ADD(peer, TCP_connection_open);
1453 break;
1454 case connect_in_progress:
1455 /* To check nonblocking connect, we wait until socket is
1456 readable or writable. */
1457 if (bgp_debug_neighbor_events(peer))
1458 zlog_debug(
1459 "%s [FSM] Non blocking connect waiting result, fd %d",
1460 peer->host, peer->fd);
1461 if (peer->fd < 0) {
1462 flog_err(EC_BGP_FSM,
1463 "bgp_start peer's fd is negative value %d",
1464 peer->fd);
1465 return -1;
1466 }
1467 /*
1468 * - when the socket becomes ready, poll() will signify POLLOUT
1469 * - if it fails to connect, poll() will signify POLLHUP
1470 * - POLLHUP is handled as a 'read' event by thread.c
1471 *
1472 * therefore, we schedule both a read and a write event with
1473 * bgp_connect_check() as the handler for each and cancel the
1474 * unused event in that function.
1475 */
1476 thread_add_read(bm->master, bgp_connect_check, peer, peer->fd,
1477 &peer->t_connect_check_r);
1478 thread_add_write(bm->master, bgp_connect_check, peer, peer->fd,
1479 &peer->t_connect_check_w);
1480 break;
1481 }
1482 return 0;
1483 }
1484
1485 /* Connect retry timer is expired when the peer status is Connect. */
1486 static int bgp_reconnect(struct peer *peer)
1487 {
1488 if (bgp_stop(peer) < 0)
1489 return -1;
1490
1491 bgp_start(peer);
1492 return 0;
1493 }
1494
1495 static int bgp_fsm_open(struct peer *peer)
1496 {
1497 /* Send keepalive and make keepalive timer */
1498 bgp_keepalive_send(peer);
1499
1500 /* Reset holdtimer value. */
1501 BGP_TIMER_OFF(peer->t_holdtime);
1502
1503 return 0;
1504 }
1505
1506 /* FSM error, unexpected event. This is error of BGP connection. So cut the
1507 peer and change to Idle status. */
1508 static int bgp_fsm_event_error(struct peer *peer)
1509 {
1510 flog_err(EC_BGP_FSM, "%s [FSM] unexpected packet received in state %s",
1511 peer->host, lookup_msg(bgp_status_msg, peer->status, NULL));
1512
1513 return bgp_stop_with_notify(peer, BGP_NOTIFY_FSM_ERR, 0);
1514 }
1515
1516 /* Hold timer expire. This is error of BGP connection. So cut the
1517 peer and change to Idle status. */
1518 static int bgp_fsm_holdtime_expire(struct peer *peer)
1519 {
1520 if (bgp_debug_neighbor_events(peer))
1521 zlog_debug("%s [FSM] Hold timer expire", peer->host);
1522
1523 return bgp_stop_with_notify(peer, BGP_NOTIFY_HOLD_ERR, 0);
1524 }
1525
1526 /**
1527 * Transition to Established state.
1528 *
1529 * Convert peer from stub to full fledged peer, set some timers, and generate
1530 * initial updates.
1531 */
1532 static int bgp_establish(struct peer *peer)
1533 {
1534 afi_t afi;
1535 safi_t safi;
1536 int nsf_af_count = 0;
1537 int ret = 0;
1538 struct peer *other;
1539
1540 other = peer->doppelganger;
1541 peer = peer_xfer_conn(peer);
1542 if (!peer) {
1543 flog_err(EC_BGP_CONNECT, "%%Neighbor failed in xfer_conn");
1544 return -1;
1545 }
1546
1547 if (other == peer)
1548 ret = 1; /* bgp_establish specific code when xfer_conn
1549 happens. */
1550
1551 /* Reset capability open status flag. */
1552 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN))
1553 SET_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN);
1554
1555 /* Clear start timer value to default. */
1556 peer->v_start = BGP_INIT_START_TIMER;
1557
1558 /* Increment established count. */
1559 peer->established++;
1560 bgp_fsm_change_status(peer, Established);
1561
1562 /* bgp log-neighbor-changes of neighbor Up */
1563 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1564 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1565 zlog_info("%%ADJCHANGE: neighbor %s(%s) in vrf %s Up",
1566 peer->host,
1567 (peer->hostname) ? peer->hostname : "Unknown",
1568 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1569 ? vrf->name
1570 : VRF_DEFAULT_NAME)
1571 : "");
1572 }
1573 /* assign update-group/subgroup */
1574 update_group_adjust_peer_afs(peer);
1575
1576 /* graceful restart */
1577 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
1578 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1579 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++) {
1580 if (peer->afc_nego[afi][safi]
1581 && CHECK_FLAG(peer->cap, PEER_CAP_RESTART_ADV)
1582 && CHECK_FLAG(peer->af_cap[afi][safi],
1583 PEER_CAP_RESTART_AF_RCV)) {
1584 if (peer->nsf[afi][safi]
1585 && !CHECK_FLAG(
1586 peer->af_cap[afi][safi],
1587 PEER_CAP_RESTART_AF_PRESERVE_RCV))
1588 bgp_clear_stale_route(peer, afi, safi);
1589
1590 peer->nsf[afi][safi] = 1;
1591 nsf_af_count++;
1592 } else {
1593 if (peer->nsf[afi][safi])
1594 bgp_clear_stale_route(peer, afi, safi);
1595 peer->nsf[afi][safi] = 0;
1596 }
1597 }
1598
1599 if (nsf_af_count)
1600 SET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1601 else {
1602 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1603 if (peer->t_gr_stale) {
1604 BGP_TIMER_OFF(peer->t_gr_stale);
1605 if (bgp_debug_neighbor_events(peer))
1606 zlog_debug(
1607 "%s graceful restart stalepath timer stopped",
1608 peer->host);
1609 }
1610 }
1611
1612 if (peer->t_gr_restart) {
1613 BGP_TIMER_OFF(peer->t_gr_restart);
1614 if (bgp_debug_neighbor_events(peer))
1615 zlog_debug("%s graceful restart timer stopped",
1616 peer->host);
1617 }
1618
1619 hook_call(peer_established, peer);
1620
1621 /* Reset uptime, turn on keepalives, send current table. */
1622 if (!peer->v_holdtime)
1623 bgp_keepalives_on(peer);
1624
1625 peer->uptime = bgp_clock();
1626
1627 /* Send route-refresh when ORF is enabled */
1628 FOREACH_AFI_SAFI (afi, safi) {
1629 if (CHECK_FLAG(peer->af_cap[afi][safi],
1630 PEER_CAP_ORF_PREFIX_SM_ADV)) {
1631 if (CHECK_FLAG(peer->af_cap[afi][safi],
1632 PEER_CAP_ORF_PREFIX_RM_RCV))
1633 bgp_route_refresh_send(peer, afi, safi,
1634 ORF_TYPE_PREFIX,
1635 REFRESH_IMMEDIATE, 0);
1636 else if (CHECK_FLAG(peer->af_cap[afi][safi],
1637 PEER_CAP_ORF_PREFIX_RM_OLD_RCV))
1638 bgp_route_refresh_send(peer, afi, safi,
1639 ORF_TYPE_PREFIX_OLD,
1640 REFRESH_IMMEDIATE, 0);
1641 }
1642 }
1643
1644 /* First update is deferred until ORF or ROUTE-REFRESH is received */
1645 FOREACH_AFI_SAFI (afi, safi) {
1646 if (CHECK_FLAG(peer->af_cap[afi][safi],
1647 PEER_CAP_ORF_PREFIX_RM_ADV))
1648 if (CHECK_FLAG(peer->af_cap[afi][safi],
1649 PEER_CAP_ORF_PREFIX_SM_RCV)
1650 || CHECK_FLAG(peer->af_cap[afi][safi],
1651 PEER_CAP_ORF_PREFIX_SM_OLD_RCV))
1652 SET_FLAG(peer->af_sflags[afi][safi],
1653 PEER_STATUS_ORF_WAIT_REFRESH);
1654 }
1655
1656 bgp_announce_peer(peer);
1657
1658 /* Start the route advertisement timer to send updates to the peer - if
1659 * BGP
1660 * is not in read-only mode. If it is, the timer will be started at the
1661 * end
1662 * of read-only mode.
1663 */
1664 if (!bgp_update_delay_active(peer->bgp)) {
1665 BGP_TIMER_OFF(peer->t_routeadv);
1666 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
1667 }
1668
1669 if (peer->doppelganger && (peer->doppelganger->status != Deleted)) {
1670 if (bgp_debug_neighbor_events(peer))
1671 zlog_debug(
1672 "[Event] Deleting stub connection for peer %s",
1673 peer->host);
1674
1675 if (peer->doppelganger->status > Active)
1676 bgp_notify_send(peer->doppelganger, BGP_NOTIFY_CEASE,
1677 BGP_NOTIFY_CEASE_COLLISION_RESOLUTION);
1678 else
1679 peer_delete(peer->doppelganger);
1680 }
1681
1682 /*
1683 * If we are replacing the old peer for a doppelganger
1684 * then switch it around in the bgp->peerhash
1685 * the doppelgangers su and this peer's su are the same
1686 * so the hash_release is the same for either.
1687 */
1688 hash_release(peer->bgp->peerhash, peer);
1689 hash_get(peer->bgp->peerhash, peer, hash_alloc_intern);
1690
1691 bgp_bfd_register_peer(peer);
1692 return ret;
1693 }
1694
1695 /* Keepalive packet is received. */
1696 static int bgp_fsm_keepalive(struct peer *peer)
1697 {
1698 BGP_TIMER_OFF(peer->t_holdtime);
1699 return 0;
1700 }
1701
1702 /* Update packet is received. */
1703 static int bgp_fsm_update(struct peer *peer)
1704 {
1705 BGP_TIMER_OFF(peer->t_holdtime);
1706 return 0;
1707 }
1708
1709 /* This is empty event. */
1710 static int bgp_ignore(struct peer *peer)
1711 {
1712 flog_err(
1713 EC_BGP_FSM,
1714 "%s [FSM] Ignoring event %s in state %s, prior events %s, %s, fd %d",
1715 peer->host, bgp_event_str[peer->cur_event],
1716 lookup_msg(bgp_status_msg, peer->status, NULL),
1717 bgp_event_str[peer->last_event],
1718 bgp_event_str[peer->last_major_event], peer->fd);
1719 return 0;
1720 }
1721
1722 /* This is to handle unexpected events.. */
1723 static int bgp_fsm_exeption(struct peer *peer)
1724 {
1725 flog_err(
1726 EC_BGP_FSM,
1727 "%s [FSM] Unexpected event %s in state %s, prior events %s, %s, fd %d",
1728 peer->host, bgp_event_str[peer->cur_event],
1729 lookup_msg(bgp_status_msg, peer->status, NULL),
1730 bgp_event_str[peer->last_event],
1731 bgp_event_str[peer->last_major_event], peer->fd);
1732 return (bgp_stop(peer));
1733 }
1734
1735 void bgp_fsm_nht_update(struct peer *peer, int valid)
1736 {
1737 if (!peer)
1738 return;
1739
1740 switch (peer->status) {
1741 case Idle:
1742 if (valid)
1743 BGP_EVENT_ADD(peer, BGP_Start);
1744 break;
1745 case Connect:
1746 if (!valid) {
1747 BGP_TIMER_OFF(peer->t_connect);
1748 BGP_EVENT_ADD(peer, TCP_fatal_error);
1749 }
1750 break;
1751 case Active:
1752 if (valid) {
1753 BGP_TIMER_OFF(peer->t_connect);
1754 BGP_EVENT_ADD(peer, ConnectRetry_timer_expired);
1755 }
1756 break;
1757 case OpenSent:
1758 case OpenConfirm:
1759 case Established:
1760 if (!valid && (peer->gtsm_hops == 1))
1761 BGP_EVENT_ADD(peer, TCP_fatal_error);
1762 case Clearing:
1763 case Deleted:
1764 default:
1765 break;
1766 }
1767 }
1768
1769
1770 /* Finite State Machine structure */
1771 static const struct {
1772 int (*func)(struct peer *);
1773 int next_state;
1774 } FSM[BGP_STATUS_MAX - 1][BGP_EVENTS_MAX - 1] = {
1775 {
1776 /* Idle state: In Idle state, all events other than BGP_Start is
1777 ignored. With BGP_Start event, finite state machine calls
1778 bgp_start(). */
1779 {bgp_start, Connect}, /* BGP_Start */
1780 {bgp_stop, Idle}, /* BGP_Stop */
1781 {bgp_stop, Idle}, /* TCP_connection_open */
1782 {bgp_stop, Idle}, /* TCP_connection_closed */
1783 {bgp_ignore, Idle}, /* TCP_connection_open_failed */
1784 {bgp_stop, Idle}, /* TCP_fatal_error */
1785 {bgp_ignore, Idle}, /* ConnectRetry_timer_expired */
1786 {bgp_ignore, Idle}, /* Hold_Timer_expired */
1787 {bgp_ignore, Idle}, /* KeepAlive_timer_expired */
1788 {bgp_ignore, Idle}, /* Receive_OPEN_message */
1789 {bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
1790 {bgp_ignore, Idle}, /* Receive_UPDATE_message */
1791 {bgp_ignore, Idle}, /* Receive_NOTIFICATION_message */
1792 {bgp_ignore, Idle}, /* Clearing_Completed */
1793 },
1794 {
1795 /* Connect */
1796 {bgp_ignore, Connect}, /* BGP_Start */
1797 {bgp_stop, Idle}, /* BGP_Stop */
1798 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1799 {bgp_stop, Idle}, /* TCP_connection_closed */
1800 {bgp_connect_fail, Active}, /* TCP_connection_open_failed */
1801 {bgp_connect_fail, Idle}, /* TCP_fatal_error */
1802 {bgp_reconnect, Connect}, /* ConnectRetry_timer_expired */
1803 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1804 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1805 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1806 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1807 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1808 {bgp_stop, Idle}, /* Receive_NOTIFICATION_message */
1809 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1810 },
1811 {
1812 /* Active, */
1813 {bgp_ignore, Active}, /* BGP_Start */
1814 {bgp_stop, Idle}, /* BGP_Stop */
1815 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1816 {bgp_stop, Idle}, /* TCP_connection_closed */
1817 {bgp_ignore, Active}, /* TCP_connection_open_failed */
1818 {bgp_fsm_exeption, Idle}, /* TCP_fatal_error */
1819 {bgp_start, Connect}, /* ConnectRetry_timer_expired */
1820 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1821 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1822 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1823 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1824 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1825 {bgp_fsm_exeption, Idle}, /* Receive_NOTIFICATION_message */
1826 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1827 },
1828 {
1829 /* OpenSent, */
1830 {bgp_ignore, OpenSent}, /* BGP_Start */
1831 {bgp_stop, Idle}, /* BGP_Stop */
1832 {bgp_stop, Active}, /* TCP_connection_open */
1833 {bgp_stop, Active}, /* TCP_connection_closed */
1834 {bgp_stop, Active}, /* TCP_connection_open_failed */
1835 {bgp_stop, Active}, /* TCP_fatal_error */
1836 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1837 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1838 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1839 {bgp_fsm_open, OpenConfirm}, /* Receive_OPEN_message */
1840 {bgp_fsm_event_error, Idle}, /* Receive_KEEPALIVE_message */
1841 {bgp_fsm_event_error, Idle}, /* Receive_UPDATE_message */
1842 {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
1843 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1844 },
1845 {
1846 /* OpenConfirm, */
1847 {bgp_ignore, OpenConfirm}, /* BGP_Start */
1848 {bgp_stop, Idle}, /* BGP_Stop */
1849 {bgp_stop, Idle}, /* TCP_connection_open */
1850 {bgp_stop, Idle}, /* TCP_connection_closed */
1851 {bgp_stop, Idle}, /* TCP_connection_open_failed */
1852 {bgp_stop, Idle}, /* TCP_fatal_error */
1853 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1854 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1855 {bgp_ignore, OpenConfirm}, /* KeepAlive_timer_expired */
1856 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1857 {bgp_establish, Established}, /* Receive_KEEPALIVE_message */
1858 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1859 {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
1860 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1861 },
1862 {
1863 /* Established, */
1864 {bgp_ignore, Established}, /* BGP_Start */
1865 {bgp_stop, Clearing}, /* BGP_Stop */
1866 {bgp_stop, Clearing}, /* TCP_connection_open */
1867 {bgp_stop, Clearing}, /* TCP_connection_closed */
1868 {bgp_stop, Clearing}, /* TCP_connection_open_failed */
1869 {bgp_stop, Clearing}, /* TCP_fatal_error */
1870 {bgp_stop, Clearing}, /* ConnectRetry_timer_expired */
1871 {bgp_fsm_holdtime_expire, Clearing}, /* Hold_Timer_expired */
1872 {bgp_ignore, Established}, /* KeepAlive_timer_expired */
1873 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1874 {bgp_fsm_keepalive,
1875 Established}, /* Receive_KEEPALIVE_message */
1876 {bgp_fsm_update, Established}, /* Receive_UPDATE_message */
1877 {bgp_stop_with_error,
1878 Clearing}, /* Receive_NOTIFICATION_message */
1879 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1880 },
1881 {
1882 /* Clearing, */
1883 {bgp_ignore, Clearing}, /* BGP_Start */
1884 {bgp_stop, Clearing}, /* BGP_Stop */
1885 {bgp_stop, Clearing}, /* TCP_connection_open */
1886 {bgp_stop, Clearing}, /* TCP_connection_closed */
1887 {bgp_stop, Clearing}, /* TCP_connection_open_failed */
1888 {bgp_stop, Clearing}, /* TCP_fatal_error */
1889 {bgp_stop, Clearing}, /* ConnectRetry_timer_expired */
1890 {bgp_stop, Clearing}, /* Hold_Timer_expired */
1891 {bgp_stop, Clearing}, /* KeepAlive_timer_expired */
1892 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1893 {bgp_stop, Clearing}, /* Receive_KEEPALIVE_message */
1894 {bgp_stop, Clearing}, /* Receive_UPDATE_message */
1895 {bgp_stop, Clearing}, /* Receive_NOTIFICATION_message */
1896 {bgp_clearing_completed, Idle}, /* Clearing_Completed */
1897 },
1898 {
1899 /* Deleted, */
1900 {bgp_ignore, Deleted}, /* BGP_Start */
1901 {bgp_ignore, Deleted}, /* BGP_Stop */
1902 {bgp_ignore, Deleted}, /* TCP_connection_open */
1903 {bgp_ignore, Deleted}, /* TCP_connection_closed */
1904 {bgp_ignore, Deleted}, /* TCP_connection_open_failed */
1905 {bgp_ignore, Deleted}, /* TCP_fatal_error */
1906 {bgp_ignore, Deleted}, /* ConnectRetry_timer_expired */
1907 {bgp_ignore, Deleted}, /* Hold_Timer_expired */
1908 {bgp_ignore, Deleted}, /* KeepAlive_timer_expired */
1909 {bgp_ignore, Deleted}, /* Receive_OPEN_message */
1910 {bgp_ignore, Deleted}, /* Receive_KEEPALIVE_message */
1911 {bgp_ignore, Deleted}, /* Receive_UPDATE_message */
1912 {bgp_ignore, Deleted}, /* Receive_NOTIFICATION_message */
1913 {bgp_ignore, Deleted}, /* Clearing_Completed */
1914 },
1915 };
1916
1917 /* Execute event process. */
1918 int bgp_event(struct thread *thread)
1919 {
1920 int event;
1921 struct peer *peer;
1922 int ret;
1923
1924 peer = THREAD_ARG(thread);
1925 event = THREAD_VAL(thread);
1926
1927 ret = bgp_event_update(peer, event);
1928
1929 return (ret);
1930 }
1931
1932 int bgp_event_update(struct peer *peer, int event)
1933 {
1934 int next;
1935 int ret = 0;
1936 struct peer *other;
1937 int passive_conn = 0;
1938 int dyn_nbr;
1939
1940 /* default return code */
1941 ret = FSM_PEER_NOOP;
1942
1943 other = peer->doppelganger;
1944 passive_conn =
1945 (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) ? 1 : 0;
1946 dyn_nbr = peer_dynamic_neighbor(peer);
1947
1948 /* Logging this event. */
1949 next = FSM[peer->status - 1][event - 1].next_state;
1950
1951 if (bgp_debug_neighbor_events(peer) && peer->status != next)
1952 zlog_debug("%s [FSM] %s (%s->%s), fd %d", peer->host,
1953 bgp_event_str[event],
1954 lookup_msg(bgp_status_msg, peer->status, NULL),
1955 lookup_msg(bgp_status_msg, next, NULL), peer->fd);
1956
1957 peer->last_event = peer->cur_event;
1958 peer->cur_event = event;
1959
1960 /* Call function. */
1961 if (FSM[peer->status - 1][event - 1].func)
1962 ret = (*(FSM[peer->status - 1][event - 1].func))(peer);
1963
1964 if (ret >= 0) {
1965 if (ret == 1 && next == Established) {
1966 /* The case when doppelganger swap accurred in
1967 bgp_establish.
1968 Update the peer pointer accordingly */
1969 ret = FSM_PEER_TRANSFERRED;
1970 peer = other;
1971 }
1972
1973 /* If status is changed. */
1974 if (next != peer->status) {
1975 bgp_fsm_change_status(peer, next);
1976
1977 /*
1978 * If we're going to ESTABLISHED then we executed a
1979 * peer transfer. In this case we can either return
1980 * FSM_PEER_TRANSITIONED or FSM_PEER_TRANSFERRED.
1981 * Opting for TRANSFERRED since transfer implies
1982 * session establishment.
1983 */
1984 if (ret != FSM_PEER_TRANSFERRED)
1985 ret = FSM_PEER_TRANSITIONED;
1986 }
1987
1988 /* Make sure timer is set. */
1989 bgp_timer_set(peer);
1990
1991 } else {
1992 /*
1993 * If we got a return value of -1, that means there was an
1994 * error, restart the FSM. Since bgp_stop() was called on the
1995 * peer. only a few fields are safe to access here. In any case
1996 * we need to indicate that the peer was stopped in the return
1997 * code.
1998 */
1999 if (!dyn_nbr && !passive_conn && peer->bgp) {
2000 flog_err(
2001 EC_BGP_FSM,
2002 "%s [FSM] Failure handling event %s in state %s, "
2003 "prior events %s, %s, fd %d",
2004 peer->host, bgp_event_str[peer->cur_event],
2005 lookup_msg(bgp_status_msg, peer->status, NULL),
2006 bgp_event_str[peer->last_event],
2007 bgp_event_str[peer->last_major_event],
2008 peer->fd);
2009 bgp_stop(peer);
2010 bgp_fsm_change_status(peer, Idle);
2011 bgp_timer_set(peer);
2012 }
2013 ret = FSM_PEER_STOPPED;
2014 }
2015
2016 return ret;
2017 }
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