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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->inst_type != BGP_INSTANCE_TYPE_VIEW &&
314 peer->bgp->vrf_id == VRF_UNKNOWN)) {
315 BGP_TIMER_OFF(peer->t_start);
316 } else {
317 BGP_TIMER_ON(peer->t_start, bgp_start_timer,
318 peer->v_start);
319 }
320 BGP_TIMER_OFF(peer->t_connect);
321 BGP_TIMER_OFF(peer->t_holdtime);
322 bgp_keepalives_off(peer);
323 BGP_TIMER_OFF(peer->t_routeadv);
324 break;
325
326 case Connect:
327 /* After start timer is expired, the peer moves to Connect
328 status. Make sure start timer is off and connect timer is
329 on. */
330 BGP_TIMER_OFF(peer->t_start);
331 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
332 peer->v_connect);
333 BGP_TIMER_OFF(peer->t_holdtime);
334 bgp_keepalives_off(peer);
335 BGP_TIMER_OFF(peer->t_routeadv);
336 break;
337
338 case Active:
339 /* Active is waiting connection from remote peer. And if
340 connect timer is expired, change status to Connect. */
341 BGP_TIMER_OFF(peer->t_start);
342 /* If peer is passive mode, do not set connect timer. */
343 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)
344 || CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
345 BGP_TIMER_OFF(peer->t_connect);
346 } else {
347 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
348 peer->v_connect);
349 }
350 BGP_TIMER_OFF(peer->t_holdtime);
351 bgp_keepalives_off(peer);
352 BGP_TIMER_OFF(peer->t_routeadv);
353 break;
354
355 case OpenSent:
356 /* OpenSent status. */
357 BGP_TIMER_OFF(peer->t_start);
358 BGP_TIMER_OFF(peer->t_connect);
359 if (peer->v_holdtime != 0) {
360 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
361 peer->v_holdtime);
362 } else {
363 BGP_TIMER_OFF(peer->t_holdtime);
364 }
365 bgp_keepalives_off(peer);
366 BGP_TIMER_OFF(peer->t_routeadv);
367 break;
368
369 case OpenConfirm:
370 /* OpenConfirm status. */
371 BGP_TIMER_OFF(peer->t_start);
372 BGP_TIMER_OFF(peer->t_connect);
373
374 /* If the negotiated Hold Time value is zero, then the Hold Time
375 timer and KeepAlive timers are not started. */
376 if (peer->v_holdtime == 0) {
377 BGP_TIMER_OFF(peer->t_holdtime);
378 bgp_keepalives_off(peer);
379 } else {
380 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
381 peer->v_holdtime);
382 bgp_keepalives_on(peer);
383 }
384 BGP_TIMER_OFF(peer->t_routeadv);
385 break;
386
387 case Established:
388 /* In Established status start and connect timer is turned
389 off. */
390 BGP_TIMER_OFF(peer->t_start);
391 BGP_TIMER_OFF(peer->t_connect);
392
393 /* Same as OpenConfirm, if holdtime is zero then both holdtime
394 and keepalive must be turned off. */
395 if (peer->v_holdtime == 0) {
396 BGP_TIMER_OFF(peer->t_holdtime);
397 bgp_keepalives_off(peer);
398 } else {
399 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
400 peer->v_holdtime);
401 bgp_keepalives_on(peer);
402 }
403 break;
404 case Deleted:
405 BGP_TIMER_OFF(peer->t_gr_restart);
406 BGP_TIMER_OFF(peer->t_gr_stale);
407 BGP_TIMER_OFF(peer->t_pmax_restart);
408 /* fallthru */
409 case Clearing:
410 BGP_TIMER_OFF(peer->t_start);
411 BGP_TIMER_OFF(peer->t_connect);
412 BGP_TIMER_OFF(peer->t_holdtime);
413 bgp_keepalives_off(peer);
414 BGP_TIMER_OFF(peer->t_routeadv);
415 break;
416 }
417 }
418
419 /* BGP start timer. This function set BGP_Start event to thread value
420 and process event. */
421 static int bgp_start_timer(struct thread *thread)
422 {
423 struct peer *peer;
424
425 peer = THREAD_ARG(thread);
426 peer->t_start = NULL;
427
428 if (bgp_debug_neighbor_events(peer))
429 zlog_debug("%s [FSM] Timer (start timer expire).", peer->host);
430
431 THREAD_VAL(thread) = BGP_Start;
432 bgp_event(thread); /* bgp_event unlocks peer */
433
434 return 0;
435 }
436
437 /* BGP connect retry timer. */
438 static int bgp_connect_timer(struct thread *thread)
439 {
440 struct peer *peer;
441 int ret;
442
443 peer = THREAD_ARG(thread);
444
445 assert(!peer->t_write);
446 assert(!peer->t_read);
447
448 peer->t_connect = NULL;
449
450 if (bgp_debug_neighbor_events(peer))
451 zlog_debug("%s [FSM] Timer (connect timer expire)", peer->host);
452
453 if (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) {
454 bgp_stop(peer);
455 ret = -1;
456 } else {
457 THREAD_VAL(thread) = ConnectRetry_timer_expired;
458 bgp_event(thread); /* bgp_event unlocks peer */
459 ret = 0;
460 }
461
462 return ret;
463 }
464
465 /* BGP holdtime timer. */
466 static int bgp_holdtime_timer(struct thread *thread)
467 {
468 struct peer *peer;
469
470 peer = THREAD_ARG(thread);
471 peer->t_holdtime = NULL;
472
473 if (bgp_debug_neighbor_events(peer))
474 zlog_debug("%s [FSM] Timer (holdtime timer expire)",
475 peer->host);
476
477 THREAD_VAL(thread) = Hold_Timer_expired;
478 bgp_event(thread); /* bgp_event unlocks peer */
479
480 return 0;
481 }
482
483 int bgp_routeadv_timer(struct thread *thread)
484 {
485 struct peer *peer;
486
487 peer = THREAD_ARG(thread);
488 peer->t_routeadv = NULL;
489
490 if (bgp_debug_neighbor_events(peer))
491 zlog_debug("%s [FSM] Timer (routeadv timer expire)",
492 peer->host);
493
494 peer->synctime = bgp_clock();
495
496 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets, peer, 0,
497 &peer->t_generate_updgrp_packets);
498
499 /* MRAI timer will be started again when FIFO is built, no need to
500 * do it here.
501 */
502 return 0;
503 }
504
505 /* BGP Peer Down Cause */
506 const char *peer_down_str[] = {"",
507 "Router ID changed",
508 "Remote AS changed",
509 "Local AS change",
510 "Cluster ID changed",
511 "Confederation identifier changed",
512 "Confederation peer changed",
513 "RR client config change",
514 "RS client config change",
515 "Update source change",
516 "Address family activated",
517 "Admin. shutdown",
518 "User reset",
519 "BGP Notification received",
520 "BGP Notification send",
521 "Peer closed the session",
522 "Neighbor deleted",
523 "Peer-group add member",
524 "Peer-group delete member",
525 "Capability changed",
526 "Passive config change",
527 "Multihop config change",
528 "NSF peer closed the session",
529 "Intf peering v6only config change",
530 "BFD down received",
531 "Interface down",
532 "Neighbor address lost"};
533
534 static int bgp_graceful_restart_timer_expire(struct thread *thread)
535 {
536 struct peer *peer;
537 afi_t afi;
538 safi_t safi;
539
540 peer = THREAD_ARG(thread);
541 peer->t_gr_restart = NULL;
542
543 /* NSF delete stale route */
544 for (afi = AFI_IP; afi < AFI_MAX; afi++)
545 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
546 if (peer->nsf[afi][safi])
547 bgp_clear_stale_route(peer, afi, safi);
548
549 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
550 BGP_TIMER_OFF(peer->t_gr_stale);
551
552 if (bgp_debug_neighbor_events(peer)) {
553 zlog_debug("%s graceful restart timer expired", peer->host);
554 zlog_debug("%s graceful restart stalepath timer stopped",
555 peer->host);
556 }
557
558 bgp_timer_set(peer);
559
560 return 0;
561 }
562
563 static int bgp_graceful_stale_timer_expire(struct thread *thread)
564 {
565 struct peer *peer;
566 afi_t afi;
567 safi_t safi;
568
569 peer = THREAD_ARG(thread);
570 peer->t_gr_stale = NULL;
571
572 if (bgp_debug_neighbor_events(peer))
573 zlog_debug("%s graceful restart stalepath timer expired",
574 peer->host);
575
576 /* NSF delete stale route */
577 for (afi = AFI_IP; afi < AFI_MAX; afi++)
578 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
579 if (peer->nsf[afi][safi])
580 bgp_clear_stale_route(peer, afi, safi);
581
582 return 0;
583 }
584
585 static int bgp_update_delay_applicable(struct bgp *bgp)
586 {
587 /* update_delay_over flag should be reset (set to 0) for any new
588 applicability of the update-delay during BGP process lifetime.
589 And it should be set after an occurence of the update-delay is
590 over)*/
591 if (!bgp->update_delay_over)
592 return 1;
593
594 return 0;
595 }
596
597 int bgp_update_delay_active(struct bgp *bgp)
598 {
599 if (bgp->t_update_delay)
600 return 1;
601
602 return 0;
603 }
604
605 int bgp_update_delay_configured(struct bgp *bgp)
606 {
607 if (bgp->v_update_delay)
608 return 1;
609
610 return 0;
611 }
612
613 /* Do the post-processing needed when bgp comes out of the read-only mode
614 on ending the update delay. */
615 void bgp_update_delay_end(struct bgp *bgp)
616 {
617 THREAD_TIMER_OFF(bgp->t_update_delay);
618 THREAD_TIMER_OFF(bgp->t_establish_wait);
619
620 /* Reset update-delay related state */
621 bgp->update_delay_over = 1;
622 bgp->established = 0;
623 bgp->restarted_peers = 0;
624 bgp->implicit_eors = 0;
625 bgp->explicit_eors = 0;
626
627 quagga_timestamp(3, bgp->update_delay_end_time,
628 sizeof(bgp->update_delay_end_time));
629
630 /*
631 * Add an end-of-initial-update marker to the main process queues so
632 * that
633 * the route advertisement timer for the peers can be started. Also set
634 * the zebra and peer update hold flags. These flags are used to achieve
635 * three stages in the update-delay post processing:
636 * 1. Finish best-path selection for all the prefixes held on the
637 * queues.
638 * (routes in BGP are updated, and peers sync queues are populated
639 * too)
640 * 2. As the eoiu mark is reached in the bgp process routine, ship all
641 * the
642 * routes to zebra. With that zebra should see updates from BGP
643 * close
644 * to each other.
645 * 3. Unblock the peer update writes. With that peer update packing
646 * with
647 * the prefixes should be at its maximum.
648 */
649 bgp_add_eoiu_mark(bgp);
650 bgp->main_zebra_update_hold = 1;
651 bgp->main_peers_update_hold = 1;
652
653 /* Resume the queue processing. This should trigger the event that would
654 take
655 care of processing any work that was queued during the read-only
656 mode. */
657 work_queue_unplug(bm->process_main_queue);
658 }
659
660 /**
661 * see bgp_fsm.h
662 */
663 void bgp_start_routeadv(struct bgp *bgp)
664 {
665 struct listnode *node, *nnode;
666 struct peer *peer;
667
668 zlog_info("bgp_start_routeadv(), update hold status %d",
669 bgp->main_peers_update_hold);
670
671 if (bgp->main_peers_update_hold)
672 return;
673
674 quagga_timestamp(3, bgp->update_delay_peers_resume_time,
675 sizeof(bgp->update_delay_peers_resume_time));
676
677 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
678 if (peer->status != Established)
679 continue;
680 BGP_TIMER_OFF(peer->t_routeadv);
681 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
682 }
683 }
684
685 /**
686 * see bgp_fsm.h
687 */
688 void bgp_adjust_routeadv(struct peer *peer)
689 {
690 time_t nowtime = bgp_clock();
691 double diff;
692 unsigned long remain;
693
694 /* Bypass checks for special case of MRAI being 0 */
695 if (peer->v_routeadv == 0) {
696 /* Stop existing timer, just in case it is running for a
697 * different
698 * duration and schedule write thread immediately.
699 */
700 if (peer->t_routeadv)
701 BGP_TIMER_OFF(peer->t_routeadv);
702
703 peer->synctime = bgp_clock();
704 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets,
705 peer, 0,
706 &peer->t_generate_updgrp_packets);
707 return;
708 }
709
710
711 /*
712 * CASE I:
713 * If the last update was written more than MRAI back, expire the timer
714 * instantly so that we can send the update out sooner.
715 *
716 * <------- MRAI --------->
717 * |-----------------|-----------------------|
718 * <------------- m ------------>
719 * ^ ^ ^
720 * | | |
721 * | | current time
722 * | timer start
723 * last write
724 *
725 * m > MRAI
726 */
727 diff = difftime(nowtime, peer->last_update);
728 if (diff > (double)peer->v_routeadv) {
729 BGP_TIMER_OFF(peer->t_routeadv);
730 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
731 return;
732 }
733
734 /*
735 * CASE II:
736 * - Find when to expire the MRAI timer.
737 * If MRAI timer is not active, assume we can start it now.
738 *
739 * <------- MRAI --------->
740 * |------------|-----------------------|
741 * <-------- m ----------><----- r ----->
742 * ^ ^ ^
743 * | | |
744 * | | current time
745 * | timer start
746 * last write
747 *
748 * (MRAI - m) < r
749 */
750 if (peer->t_routeadv)
751 remain = thread_timer_remain_second(peer->t_routeadv);
752 else
753 remain = peer->v_routeadv;
754 diff = peer->v_routeadv - diff;
755 if (diff <= (double)remain) {
756 BGP_TIMER_OFF(peer->t_routeadv);
757 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, diff);
758 }
759 }
760
761 static int bgp_maxmed_onstartup_applicable(struct bgp *bgp)
762 {
763 if (!bgp->maxmed_onstartup_over)
764 return 1;
765
766 return 0;
767 }
768
769 int bgp_maxmed_onstartup_configured(struct bgp *bgp)
770 {
771 if (bgp->v_maxmed_onstartup != BGP_MAXMED_ONSTARTUP_UNCONFIGURED)
772 return 1;
773
774 return 0;
775 }
776
777 int bgp_maxmed_onstartup_active(struct bgp *bgp)
778 {
779 if (bgp->t_maxmed_onstartup)
780 return 1;
781
782 return 0;
783 }
784
785 void bgp_maxmed_update(struct bgp *bgp)
786 {
787 uint8_t maxmed_active;
788 uint32_t maxmed_value;
789
790 if (bgp->v_maxmed_admin) {
791 maxmed_active = 1;
792 maxmed_value = bgp->maxmed_admin_value;
793 } else if (bgp->t_maxmed_onstartup) {
794 maxmed_active = 1;
795 maxmed_value = bgp->maxmed_onstartup_value;
796 } else {
797 maxmed_active = 0;
798 maxmed_value = BGP_MAXMED_VALUE_DEFAULT;
799 }
800
801 if (bgp->maxmed_active != maxmed_active
802 || bgp->maxmed_value != maxmed_value) {
803 bgp->maxmed_active = maxmed_active;
804 bgp->maxmed_value = maxmed_value;
805
806 update_group_announce(bgp);
807 }
808 }
809
810 /* The maxmed onstartup timer expiry callback. */
811 static int bgp_maxmed_onstartup_timer(struct thread *thread)
812 {
813 struct bgp *bgp;
814
815 zlog_info("Max med on startup ended - timer expired.");
816
817 bgp = THREAD_ARG(thread);
818 THREAD_TIMER_OFF(bgp->t_maxmed_onstartup);
819 bgp->maxmed_onstartup_over = 1;
820
821 bgp_maxmed_update(bgp);
822
823 return 0;
824 }
825
826 static void bgp_maxmed_onstartup_begin(struct bgp *bgp)
827 {
828 /* Applicable only once in the process lifetime on the startup */
829 if (bgp->maxmed_onstartup_over)
830 return;
831
832 zlog_info("Begin maxmed onstartup mode - timer %d seconds",
833 bgp->v_maxmed_onstartup);
834
835 thread_add_timer(bm->master, bgp_maxmed_onstartup_timer, bgp,
836 bgp->v_maxmed_onstartup, &bgp->t_maxmed_onstartup);
837
838 if (!bgp->v_maxmed_admin) {
839 bgp->maxmed_active = 1;
840 bgp->maxmed_value = bgp->maxmed_onstartup_value;
841 }
842
843 /* Route announce to all peers should happen after this in
844 * bgp_establish() */
845 }
846
847 static void bgp_maxmed_onstartup_process_status_change(struct peer *peer)
848 {
849 if (peer->status == Established && !peer->bgp->established) {
850 bgp_maxmed_onstartup_begin(peer->bgp);
851 }
852 }
853
854 /* The update delay timer expiry callback. */
855 static int bgp_update_delay_timer(struct thread *thread)
856 {
857 struct bgp *bgp;
858
859 zlog_info("Update delay ended - timer expired.");
860
861 bgp = THREAD_ARG(thread);
862 THREAD_TIMER_OFF(bgp->t_update_delay);
863 bgp_update_delay_end(bgp);
864
865 return 0;
866 }
867
868 /* The establish wait timer expiry callback. */
869 static int bgp_establish_wait_timer(struct thread *thread)
870 {
871 struct bgp *bgp;
872
873 zlog_info("Establish wait - timer expired.");
874
875 bgp = THREAD_ARG(thread);
876 THREAD_TIMER_OFF(bgp->t_establish_wait);
877 bgp_check_update_delay(bgp);
878
879 return 0;
880 }
881
882 /* Steps to begin the update delay:
883 - initialize queues if needed
884 - stop the queue processing
885 - start the timer */
886 static void bgp_update_delay_begin(struct bgp *bgp)
887 {
888 struct listnode *node, *nnode;
889 struct peer *peer;
890
891 /* Stop the processing of queued work. Enqueue shall continue */
892 work_queue_plug(bm->process_main_queue);
893
894 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer))
895 peer->update_delay_over = 0;
896
897 /* Start the update-delay timer */
898 thread_add_timer(bm->master, bgp_update_delay_timer, bgp,
899 bgp->v_update_delay, &bgp->t_update_delay);
900
901 if (bgp->v_establish_wait != bgp->v_update_delay)
902 thread_add_timer(bm->master, bgp_establish_wait_timer, bgp,
903 bgp->v_establish_wait, &bgp->t_establish_wait);
904
905 quagga_timestamp(3, bgp->update_delay_begin_time,
906 sizeof(bgp->update_delay_begin_time));
907 }
908
909 static void bgp_update_delay_process_status_change(struct peer *peer)
910 {
911 if (peer->status == Established) {
912 if (!peer->bgp->established++) {
913 bgp_update_delay_begin(peer->bgp);
914 zlog_info(
915 "Begin read-only mode - update-delay timer %d seconds",
916 peer->bgp->v_update_delay);
917 }
918 if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_BIT_RCV))
919 bgp_update_restarted_peers(peer);
920 }
921 if (peer->ostatus == Established
922 && bgp_update_delay_active(peer->bgp)) {
923 /* Adjust the update-delay state to account for this flap.
924 NOTE: Intentionally skipping adjusting implicit_eors or
925 explicit_eors
926 counters. Extra sanity check in bgp_check_update_delay()
927 should
928 be enough to take care of any additive discrepancy in bgp eor
929 counters */
930 peer->bgp->established--;
931 peer->update_delay_over = 0;
932 }
933 }
934
935 /* Called after event occurred, this function change status and reset
936 read/write and timer thread. */
937 void bgp_fsm_change_status(struct peer *peer, int status)
938 {
939 struct bgp *bgp;
940 uint32_t peer_count;
941
942 bgp_dump_state(peer, peer->status, status);
943
944 bgp = peer->bgp;
945 peer_count = bgp->established_peers;
946
947 if (status == Established)
948 bgp->established_peers++;
949 else if ((peer->status == Established) && (status != Established))
950 bgp->established_peers--;
951
952 if (BGP_DEBUG(neighbor_events, NEIGHBOR_EVENTS))
953 zlog_debug("%s : vrf %u, established_peers %u", __func__,
954 bgp->vrf_id, bgp->established_peers);
955 /* Set to router ID to the value provided by RIB if there are no peers
956 * in the established state and peer count did not change
957 */
958 if ((peer_count != bgp->established_peers) &&
959 (bgp->established_peers == 0))
960 bgp_router_id_zebra_bump(bgp->vrf_id, NULL);
961
962 /* Transition into Clearing or Deleted must /always/ clear all routes..
963 * (and must do so before actually changing into Deleted..
964 */
965 if (status >= Clearing) {
966 bgp_clear_route_all(peer);
967
968 /* If no route was queued for the clear-node processing,
969 * generate the
970 * completion event here. This is needed because if there are no
971 * routes
972 * to trigger the background clear-node thread, the event won't
973 * get
974 * generated and the peer would be stuck in Clearing. Note that
975 * this
976 * event is for the peer and helps the peer transition out of
977 * Clearing
978 * state; it should not be generated per (AFI,SAFI). The event
979 * is
980 * directly posted here without calling clear_node_complete() as
981 * we
982 * shouldn't do an extra unlock. This event will get processed
983 * after
984 * the state change that happens below, so peer will be in
985 * Clearing
986 * (or Deleted).
987 */
988 if (!work_queue_is_scheduled(peer->clear_node_queue))
989 BGP_EVENT_ADD(peer, Clearing_Completed);
990 }
991
992 /* Preserve old status and change into new status. */
993 peer->ostatus = peer->status;
994 peer->status = status;
995
996 /* Save event that caused status change. */
997 peer->last_major_event = peer->cur_event;
998
999 if (status == Established)
1000 UNSET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER);
1001
1002 /* If max-med processing is applicable, do the necessary. */
1003 if (status == Established) {
1004 if (bgp_maxmed_onstartup_configured(peer->bgp)
1005 && bgp_maxmed_onstartup_applicable(peer->bgp))
1006 bgp_maxmed_onstartup_process_status_change(peer);
1007 else
1008 peer->bgp->maxmed_onstartup_over = 1;
1009 }
1010
1011 /* If update-delay processing is applicable, do the necessary. */
1012 if (bgp_update_delay_configured(peer->bgp)
1013 && bgp_update_delay_applicable(peer->bgp))
1014 bgp_update_delay_process_status_change(peer);
1015
1016 if (bgp_debug_neighbor_events(peer))
1017 zlog_debug("%s went from %s to %s", peer->host,
1018 lookup_msg(bgp_status_msg, peer->ostatus, NULL),
1019 lookup_msg(bgp_status_msg, peer->status, NULL));
1020 }
1021
1022 /* Flush the event queue and ensure the peer is shut down */
1023 static int bgp_clearing_completed(struct peer *peer)
1024 {
1025 int rc = bgp_stop(peer);
1026
1027 if (rc >= 0)
1028 BGP_EVENT_FLUSH(peer);
1029
1030 return rc;
1031 }
1032
1033 /* Administrative BGP peer stop event. */
1034 /* May be called multiple times for the same peer */
1035 int bgp_stop(struct peer *peer)
1036 {
1037 afi_t afi;
1038 safi_t safi;
1039 char orf_name[BUFSIZ];
1040 int ret = 0;
1041
1042 if (peer_dynamic_neighbor(peer)
1043 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1044 if (bgp_debug_neighbor_events(peer))
1045 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1046 peer_delete(peer);
1047 return -1;
1048 }
1049
1050 /* Can't do this in Clearing; events are used for state transitions */
1051 if (peer->status != Clearing) {
1052 /* Delete all existing events of the peer */
1053 BGP_EVENT_FLUSH(peer);
1054 }
1055
1056 /* Increment Dropped count. */
1057 if (peer->status == Established) {
1058 peer->dropped++;
1059
1060 /* bgp log-neighbor-changes of neighbor Down */
1061 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1062 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1063 zlog_info(
1064 "%%ADJCHANGE: neighbor %s(%s) in vrf %s Down %s",
1065 peer->host,
1066 (peer->hostname) ? peer->hostname : "Unknown",
1067 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1068 ? vrf->name
1069 : VRF_DEFAULT_NAME)
1070 : "",
1071 peer_down_str[(int)peer->last_reset]);
1072 }
1073
1074 /* graceful restart */
1075 if (peer->t_gr_stale) {
1076 BGP_TIMER_OFF(peer->t_gr_stale);
1077 if (bgp_debug_neighbor_events(peer))
1078 zlog_debug(
1079 "%s graceful restart stalepath timer stopped",
1080 peer->host);
1081 }
1082 if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
1083 if (bgp_debug_neighbor_events(peer)) {
1084 zlog_debug(
1085 "%s graceful restart timer started for %d sec",
1086 peer->host, peer->v_gr_restart);
1087 zlog_debug(
1088 "%s graceful restart stalepath timer started for %d sec",
1089 peer->host, peer->bgp->stalepath_time);
1090 }
1091 BGP_TIMER_ON(peer->t_gr_restart,
1092 bgp_graceful_restart_timer_expire,
1093 peer->v_gr_restart);
1094 BGP_TIMER_ON(peer->t_gr_stale,
1095 bgp_graceful_stale_timer_expire,
1096 peer->bgp->stalepath_time);
1097 } else {
1098 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1099
1100 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1101 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN;
1102 safi++)
1103 peer->nsf[afi][safi] = 0;
1104 }
1105
1106 /* set last reset time */
1107 peer->resettime = peer->uptime = bgp_clock();
1108
1109 if (BGP_DEBUG(update_groups, UPDATE_GROUPS))
1110 zlog_debug("%s remove from all update group",
1111 peer->host);
1112 update_group_remove_peer_afs(peer);
1113
1114 hook_call(peer_backward_transition, peer);
1115
1116 /* Reset peer synctime */
1117 peer->synctime = 0;
1118 }
1119
1120 /* stop keepalives */
1121 bgp_keepalives_off(peer);
1122
1123 /* Stop read and write threads. */
1124 bgp_writes_off(peer);
1125 bgp_reads_off(peer);
1126
1127 THREAD_OFF(peer->t_connect_check_r);
1128 THREAD_OFF(peer->t_connect_check_w);
1129
1130 /* Stop all timers. */
1131 BGP_TIMER_OFF(peer->t_start);
1132 BGP_TIMER_OFF(peer->t_connect);
1133 BGP_TIMER_OFF(peer->t_holdtime);
1134 BGP_TIMER_OFF(peer->t_routeadv);
1135
1136 /* Clear input and output buffer. */
1137 pthread_mutex_lock(&peer->io_mtx);
1138 {
1139 if (peer->ibuf)
1140 stream_fifo_clean(peer->ibuf);
1141 if (peer->obuf)
1142 stream_fifo_clean(peer->obuf);
1143
1144 if (peer->ibuf_work)
1145 ringbuf_wipe(peer->ibuf_work);
1146 if (peer->obuf_work)
1147 stream_reset(peer->obuf_work);
1148
1149 if (peer->curr) {
1150 stream_free(peer->curr);
1151 peer->curr = NULL;
1152 }
1153 }
1154 pthread_mutex_unlock(&peer->io_mtx);
1155
1156 /* Close of file descriptor. */
1157 if (peer->fd >= 0) {
1158 close(peer->fd);
1159 peer->fd = -1;
1160 }
1161
1162 FOREACH_AFI_SAFI (afi, safi) {
1163 /* Reset all negotiated variables */
1164 peer->afc_nego[afi][safi] = 0;
1165 peer->afc_adv[afi][safi] = 0;
1166 peer->afc_recv[afi][safi] = 0;
1167
1168 /* peer address family capability flags*/
1169 peer->af_cap[afi][safi] = 0;
1170
1171 /* peer address family status flags*/
1172 peer->af_sflags[afi][safi] = 0;
1173
1174 /* Received ORF prefix-filter */
1175 peer->orf_plist[afi][safi] = NULL;
1176
1177 if ((peer->status == OpenConfirm)
1178 || (peer->status == Established)) {
1179 /* ORF received prefix-filter pnt */
1180 sprintf(orf_name, "%s.%d.%d", peer->host, afi, safi);
1181 prefix_bgp_orf_remove_all(afi, orf_name);
1182 }
1183 }
1184
1185 /* Reset keepalive and holdtime */
1186 if (CHECK_FLAG(peer->flags, PEER_FLAG_TIMER)) {
1187 peer->v_keepalive = peer->keepalive;
1188 peer->v_holdtime = peer->holdtime;
1189 } else {
1190 peer->v_keepalive = peer->bgp->default_keepalive;
1191 peer->v_holdtime = peer->bgp->default_holdtime;
1192 }
1193
1194 peer->update_time = 0;
1195
1196 /* Until we are sure that there is no problem about prefix count
1197 this should be commented out.*/
1198 #if 0
1199 /* Reset prefix count */
1200 peer->pcount[AFI_IP][SAFI_UNICAST] = 0;
1201 peer->pcount[AFI_IP][SAFI_MULTICAST] = 0;
1202 peer->pcount[AFI_IP][SAFI_LABELED_UNICAST] = 0;
1203 peer->pcount[AFI_IP][SAFI_MPLS_VPN] = 0;
1204 peer->pcount[AFI_IP6][SAFI_UNICAST] = 0;
1205 peer->pcount[AFI_IP6][SAFI_MULTICAST] = 0;
1206 peer->pcount[AFI_IP6][SAFI_LABELED_UNICAST] = 0;
1207 #endif /* 0 */
1208
1209 if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE)
1210 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1211 peer_delete(peer);
1212 ret = -1;
1213 } else {
1214 bgp_peer_conf_if_to_su_update(peer);
1215 }
1216
1217 return ret;
1218 }
1219
1220 /* BGP peer is stoped by the error. */
1221 static int bgp_stop_with_error(struct peer *peer)
1222 {
1223 /* Double start timer. */
1224 peer->v_start *= 2;
1225
1226 /* Overflow check. */
1227 if (peer->v_start >= (60 * 2))
1228 peer->v_start = (60 * 2);
1229
1230 if (peer_dynamic_neighbor(peer)) {
1231 if (bgp_debug_neighbor_events(peer))
1232 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1233 peer_delete(peer);
1234 return -1;
1235 }
1236
1237 return (bgp_stop(peer));
1238 }
1239
1240
1241 /* something went wrong, send notify and tear down */
1242 static int bgp_stop_with_notify(struct peer *peer, uint8_t code,
1243 uint8_t sub_code)
1244 {
1245 /* Send notify to remote peer */
1246 bgp_notify_send(peer, code, sub_code);
1247
1248 if (peer_dynamic_neighbor(peer)) {
1249 if (bgp_debug_neighbor_events(peer))
1250 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1251 peer_delete(peer);
1252 return -1;
1253 }
1254
1255 /* Clear start timer value to default. */
1256 peer->v_start = BGP_INIT_START_TIMER;
1257
1258 return (bgp_stop(peer));
1259 }
1260
1261 /**
1262 * Determines whether a TCP session has successfully established for a peer and
1263 * events as appropriate.
1264 *
1265 * This function is called when setting up a new session. After connect() is
1266 * called on the peer's socket (in bgp_start()), the fd is passed to poll()
1267 * to wait for connection success or failure. When poll() returns, this
1268 * function is called to evaluate the result.
1269 *
1270 * Due to differences in behavior of poll() on Linux and BSD - specifically,
1271 * the value of .revents in the case of a closed connection - this function is
1272 * scheduled both for a read and a write event. The write event is triggered
1273 * when the connection is established. A read event is triggered when the
1274 * connection is closed. Thus we need to cancel whichever one did not occur.
1275 */
1276 static int bgp_connect_check(struct thread *thread)
1277 {
1278 int status;
1279 socklen_t slen;
1280 int ret;
1281 struct peer *peer;
1282
1283 peer = THREAD_ARG(thread);
1284 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1285 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1286 assert(!peer->t_read);
1287 assert(!peer->t_write);
1288
1289 THREAD_OFF(peer->t_connect_check_r);
1290 THREAD_OFF(peer->t_connect_check_w);
1291
1292 /* Check file descriptor. */
1293 slen = sizeof(status);
1294 ret = getsockopt(peer->fd, SOL_SOCKET, SO_ERROR, (void *)&status,
1295 &slen);
1296
1297 /* If getsockopt is fail, this is fatal error. */
1298 if (ret < 0) {
1299 zlog_info("can't get sockopt for nonblocking connect: %d(%s)",
1300 errno, safe_strerror(errno));
1301 BGP_EVENT_ADD(peer, TCP_fatal_error);
1302 return -1;
1303 }
1304
1305 /* When status is 0 then TCP connection is established. */
1306 if (status == 0) {
1307 BGP_EVENT_ADD(peer, TCP_connection_open);
1308 return 1;
1309 } else {
1310 if (bgp_debug_neighbor_events(peer))
1311 zlog_debug("%s [Event] Connect failed %d(%s)",
1312 peer->host, status, safe_strerror(status));
1313 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1314 return 0;
1315 }
1316 }
1317
1318 /* TCP connection open. Next we send open message to remote peer. And
1319 add read thread for reading open message. */
1320 static int bgp_connect_success(struct peer *peer)
1321 {
1322 if (peer->fd < 0) {
1323 flog_err(EC_BGP_CONNECT,
1324 "bgp_connect_success peer's fd is negative value %d",
1325 peer->fd);
1326 bgp_stop(peer);
1327 return -1;
1328 }
1329
1330 if (bgp_getsockname(peer) < 0) {
1331 flog_err_sys(EC_LIB_SOCKET,
1332 "%s: bgp_getsockname(): failed for peer %s, fd %d",
1333 __FUNCTION__, peer->host, peer->fd);
1334 bgp_notify_send(peer, BGP_NOTIFY_FSM_ERR,
1335 0); /* internal error */
1336 bgp_writes_on(peer);
1337 return -1;
1338 }
1339
1340 bgp_reads_on(peer);
1341
1342 if (bgp_debug_neighbor_events(peer)) {
1343 char buf1[SU_ADDRSTRLEN];
1344
1345 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER))
1346 zlog_debug("%s open active, local address %s",
1347 peer->host,
1348 sockunion2str(peer->su_local, buf1,
1349 SU_ADDRSTRLEN));
1350 else
1351 zlog_debug("%s passive open", peer->host);
1352 }
1353
1354 bgp_open_send(peer);
1355
1356 return 0;
1357 }
1358
1359 /* TCP connect fail */
1360 static int bgp_connect_fail(struct peer *peer)
1361 {
1362 if (peer_dynamic_neighbor(peer)) {
1363 if (bgp_debug_neighbor_events(peer))
1364 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1365 peer_delete(peer);
1366 return -1;
1367 }
1368
1369 return (bgp_stop(peer));
1370 }
1371
1372 /* This function is the first starting point of all BGP connection. It
1373 try to connect to remote peer with non-blocking IO. */
1374 int bgp_start(struct peer *peer)
1375 {
1376 int status;
1377 int connected = 0;
1378
1379 bgp_peer_conf_if_to_su_update(peer);
1380
1381 if (peer->su.sa.sa_family == AF_UNSPEC) {
1382 if (bgp_debug_neighbor_events(peer))
1383 zlog_debug(
1384 "%s [FSM] Unable to get neighbor's IP address, waiting...",
1385 peer->host);
1386 return -1;
1387 }
1388
1389 if (BGP_PEER_START_SUPPRESSED(peer)) {
1390 if (bgp_debug_neighbor_events(peer))
1391 flog_err(EC_BGP_FSM,
1392 "%s [FSM] Trying to start suppressed peer"
1393 " - this is never supposed to happen!",
1394 peer->host);
1395 return -1;
1396 }
1397
1398 /* Scrub some information that might be left over from a previous,
1399 * session
1400 */
1401 /* Connection information. */
1402 if (peer->su_local) {
1403 sockunion_free(peer->su_local);
1404 peer->su_local = NULL;
1405 }
1406
1407 if (peer->su_remote) {
1408 sockunion_free(peer->su_remote);
1409 peer->su_remote = NULL;
1410 }
1411
1412 /* Clear remote router-id. */
1413 peer->remote_id.s_addr = 0;
1414
1415 /* Clear peer capability flag. */
1416 peer->cap = 0;
1417
1418 /* If the peer is passive mode, force to move to Active mode. */
1419 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)) {
1420 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1421 return 0;
1422 }
1423
1424 if (peer->bgp->inst_type != BGP_INSTANCE_TYPE_VIEW &&
1425 peer->bgp->vrf_id == VRF_UNKNOWN) {
1426 if (bgp_debug_neighbor_events(peer))
1427 flog_err(
1428 EC_BGP_FSM,
1429 "%s [FSM] In a VRF that is not initialised yet",
1430 peer->host);
1431 return -1;
1432 }
1433
1434 /* Register to be notified on peer up */
1435 if (peer->sort == BGP_PEER_EBGP && peer->ttl == 1
1436 && !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
1437 && !bgp_flag_check(peer->bgp, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
1438 connected = 1;
1439 else
1440 connected = 0;
1441
1442 if (!bgp_find_or_add_nexthop(peer->bgp, peer->bgp,
1443 family2afi(peer->su.sa.sa_family), NULL,
1444 peer, connected)) {
1445 if (bgp_zebra_num_connects()) {
1446 if (bgp_debug_neighbor_events(peer))
1447 zlog_debug("%s [FSM] Waiting for NHT",
1448 peer->host);
1449
1450 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1451 return 0;
1452 }
1453 }
1454
1455 assert(!peer->t_write);
1456 assert(!peer->t_read);
1457 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1458 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1459 status = bgp_connect(peer);
1460
1461 switch (status) {
1462 case connect_error:
1463 if (bgp_debug_neighbor_events(peer))
1464 zlog_debug("%s [FSM] Connect error", peer->host);
1465 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1466 break;
1467 case connect_success:
1468 if (bgp_debug_neighbor_events(peer))
1469 zlog_debug(
1470 "%s [FSM] Connect immediately success, fd %d",
1471 peer->host, peer->fd);
1472 BGP_EVENT_ADD(peer, TCP_connection_open);
1473 break;
1474 case connect_in_progress:
1475 /* To check nonblocking connect, we wait until socket is
1476 readable or writable. */
1477 if (bgp_debug_neighbor_events(peer))
1478 zlog_debug(
1479 "%s [FSM] Non blocking connect waiting result, fd %d",
1480 peer->host, peer->fd);
1481 if (peer->fd < 0) {
1482 flog_err(EC_BGP_FSM,
1483 "bgp_start peer's fd is negative value %d",
1484 peer->fd);
1485 return -1;
1486 }
1487 /*
1488 * - when the socket becomes ready, poll() will signify POLLOUT
1489 * - if it fails to connect, poll() will signify POLLHUP
1490 * - POLLHUP is handled as a 'read' event by thread.c
1491 *
1492 * therefore, we schedule both a read and a write event with
1493 * bgp_connect_check() as the handler for each and cancel the
1494 * unused event in that function.
1495 */
1496 thread_add_read(bm->master, bgp_connect_check, peer, peer->fd,
1497 &peer->t_connect_check_r);
1498 thread_add_write(bm->master, bgp_connect_check, peer, peer->fd,
1499 &peer->t_connect_check_w);
1500 break;
1501 }
1502 return 0;
1503 }
1504
1505 /* Connect retry timer is expired when the peer status is Connect. */
1506 static int bgp_reconnect(struct peer *peer)
1507 {
1508 if (bgp_stop(peer) < 0)
1509 return -1;
1510
1511 bgp_start(peer);
1512 return 0;
1513 }
1514
1515 static int bgp_fsm_open(struct peer *peer)
1516 {
1517 /* Send keepalive and make keepalive timer */
1518 bgp_keepalive_send(peer);
1519
1520 /* Reset holdtimer value. */
1521 BGP_TIMER_OFF(peer->t_holdtime);
1522
1523 return 0;
1524 }
1525
1526 /* FSM error, unexpected event. This is error of BGP connection. So cut the
1527 peer and change to Idle status. */
1528 static int bgp_fsm_event_error(struct peer *peer)
1529 {
1530 flog_err(EC_BGP_FSM, "%s [FSM] unexpected packet received in state %s",
1531 peer->host, lookup_msg(bgp_status_msg, peer->status, NULL));
1532
1533 return bgp_stop_with_notify(peer, BGP_NOTIFY_FSM_ERR, 0);
1534 }
1535
1536 /* Hold timer expire. This is error of BGP connection. So cut the
1537 peer and change to Idle status. */
1538 static int bgp_fsm_holdtime_expire(struct peer *peer)
1539 {
1540 if (bgp_debug_neighbor_events(peer))
1541 zlog_debug("%s [FSM] Hold timer expire", peer->host);
1542
1543 return bgp_stop_with_notify(peer, BGP_NOTIFY_HOLD_ERR, 0);
1544 }
1545
1546 /**
1547 * Transition to Established state.
1548 *
1549 * Convert peer from stub to full fledged peer, set some timers, and generate
1550 * initial updates.
1551 */
1552 static int bgp_establish(struct peer *peer)
1553 {
1554 afi_t afi;
1555 safi_t safi;
1556 int nsf_af_count = 0;
1557 int ret = 0;
1558 struct peer *other;
1559
1560 other = peer->doppelganger;
1561 peer = peer_xfer_conn(peer);
1562 if (!peer) {
1563 flog_err(EC_BGP_CONNECT, "%%Neighbor failed in xfer_conn");
1564 return -1;
1565 }
1566
1567 if (other == peer)
1568 ret = 1; /* bgp_establish specific code when xfer_conn
1569 happens. */
1570
1571 /* Reset capability open status flag. */
1572 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN))
1573 SET_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN);
1574
1575 /* Clear start timer value to default. */
1576 peer->v_start = BGP_INIT_START_TIMER;
1577
1578 /* Increment established count. */
1579 peer->established++;
1580 bgp_fsm_change_status(peer, Established);
1581
1582 /* bgp log-neighbor-changes of neighbor Up */
1583 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1584 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1585 zlog_info("%%ADJCHANGE: neighbor %s(%s) in vrf %s Up",
1586 peer->host,
1587 (peer->hostname) ? peer->hostname : "Unknown",
1588 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1589 ? vrf->name
1590 : VRF_DEFAULT_NAME)
1591 : "");
1592 }
1593 /* assign update-group/subgroup */
1594 update_group_adjust_peer_afs(peer);
1595
1596 /* graceful restart */
1597 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
1598 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1599 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++) {
1600 if (peer->afc_nego[afi][safi]
1601 && CHECK_FLAG(peer->cap, PEER_CAP_RESTART_ADV)
1602 && CHECK_FLAG(peer->af_cap[afi][safi],
1603 PEER_CAP_RESTART_AF_RCV)) {
1604 if (peer->nsf[afi][safi]
1605 && !CHECK_FLAG(
1606 peer->af_cap[afi][safi],
1607 PEER_CAP_RESTART_AF_PRESERVE_RCV))
1608 bgp_clear_stale_route(peer, afi, safi);
1609
1610 peer->nsf[afi][safi] = 1;
1611 nsf_af_count++;
1612 } else {
1613 if (peer->nsf[afi][safi])
1614 bgp_clear_stale_route(peer, afi, safi);
1615 peer->nsf[afi][safi] = 0;
1616 }
1617 }
1618
1619 if (nsf_af_count)
1620 SET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1621 else {
1622 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1623 if (peer->t_gr_stale) {
1624 BGP_TIMER_OFF(peer->t_gr_stale);
1625 if (bgp_debug_neighbor_events(peer))
1626 zlog_debug(
1627 "%s graceful restart stalepath timer stopped",
1628 peer->host);
1629 }
1630 }
1631
1632 if (peer->t_gr_restart) {
1633 BGP_TIMER_OFF(peer->t_gr_restart);
1634 if (bgp_debug_neighbor_events(peer))
1635 zlog_debug("%s graceful restart timer stopped",
1636 peer->host);
1637 }
1638
1639 hook_call(peer_established, peer);
1640
1641 /* Reset uptime, turn on keepalives, send current table. */
1642 if (!peer->v_holdtime)
1643 bgp_keepalives_on(peer);
1644
1645 peer->uptime = bgp_clock();
1646
1647 /* Send route-refresh when ORF is enabled */
1648 FOREACH_AFI_SAFI (afi, safi) {
1649 if (CHECK_FLAG(peer->af_cap[afi][safi],
1650 PEER_CAP_ORF_PREFIX_SM_ADV)) {
1651 if (CHECK_FLAG(peer->af_cap[afi][safi],
1652 PEER_CAP_ORF_PREFIX_RM_RCV))
1653 bgp_route_refresh_send(peer, afi, safi,
1654 ORF_TYPE_PREFIX,
1655 REFRESH_IMMEDIATE, 0);
1656 else if (CHECK_FLAG(peer->af_cap[afi][safi],
1657 PEER_CAP_ORF_PREFIX_RM_OLD_RCV))
1658 bgp_route_refresh_send(peer, afi, safi,
1659 ORF_TYPE_PREFIX_OLD,
1660 REFRESH_IMMEDIATE, 0);
1661 }
1662 }
1663
1664 /* First update is deferred until ORF or ROUTE-REFRESH is received */
1665 FOREACH_AFI_SAFI (afi, safi) {
1666 if (CHECK_FLAG(peer->af_cap[afi][safi],
1667 PEER_CAP_ORF_PREFIX_RM_ADV))
1668 if (CHECK_FLAG(peer->af_cap[afi][safi],
1669 PEER_CAP_ORF_PREFIX_SM_RCV)
1670 || CHECK_FLAG(peer->af_cap[afi][safi],
1671 PEER_CAP_ORF_PREFIX_SM_OLD_RCV))
1672 SET_FLAG(peer->af_sflags[afi][safi],
1673 PEER_STATUS_ORF_WAIT_REFRESH);
1674 }
1675
1676 bgp_announce_peer(peer);
1677
1678 /* Start the route advertisement timer to send updates to the peer - if
1679 * BGP
1680 * is not in read-only mode. If it is, the timer will be started at the
1681 * end
1682 * of read-only mode.
1683 */
1684 if (!bgp_update_delay_active(peer->bgp)) {
1685 BGP_TIMER_OFF(peer->t_routeadv);
1686 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
1687 }
1688
1689 if (peer->doppelganger && (peer->doppelganger->status != Deleted)) {
1690 if (bgp_debug_neighbor_events(peer))
1691 zlog_debug(
1692 "[Event] Deleting stub connection for peer %s",
1693 peer->host);
1694
1695 if (peer->doppelganger->status > Active)
1696 bgp_notify_send(peer->doppelganger, BGP_NOTIFY_CEASE,
1697 BGP_NOTIFY_CEASE_COLLISION_RESOLUTION);
1698 else
1699 peer_delete(peer->doppelganger);
1700 }
1701
1702 /*
1703 * If we are replacing the old peer for a doppelganger
1704 * then switch it around in the bgp->peerhash
1705 * the doppelgangers su and this peer's su are the same
1706 * so the hash_release is the same for either.
1707 */
1708 hash_release(peer->bgp->peerhash, peer);
1709 hash_get(peer->bgp->peerhash, peer, hash_alloc_intern);
1710
1711 bgp_bfd_register_peer(peer);
1712 return ret;
1713 }
1714
1715 /* Keepalive packet is received. */
1716 static int bgp_fsm_keepalive(struct peer *peer)
1717 {
1718 BGP_TIMER_OFF(peer->t_holdtime);
1719 return 0;
1720 }
1721
1722 /* Update packet is received. */
1723 static int bgp_fsm_update(struct peer *peer)
1724 {
1725 BGP_TIMER_OFF(peer->t_holdtime);
1726 return 0;
1727 }
1728
1729 /* This is empty event. */
1730 static int bgp_ignore(struct peer *peer)
1731 {
1732 flog_err(
1733 EC_BGP_FSM,
1734 "%s [FSM] Ignoring event %s in state %s, prior events %s, %s, fd %d",
1735 peer->host, bgp_event_str[peer->cur_event],
1736 lookup_msg(bgp_status_msg, peer->status, NULL),
1737 bgp_event_str[peer->last_event],
1738 bgp_event_str[peer->last_major_event], peer->fd);
1739 return 0;
1740 }
1741
1742 /* This is to handle unexpected events.. */
1743 static int bgp_fsm_exeption(struct peer *peer)
1744 {
1745 flog_err(
1746 EC_BGP_FSM,
1747 "%s [FSM] Unexpected event %s in state %s, prior events %s, %s, fd %d",
1748 peer->host, bgp_event_str[peer->cur_event],
1749 lookup_msg(bgp_status_msg, peer->status, NULL),
1750 bgp_event_str[peer->last_event],
1751 bgp_event_str[peer->last_major_event], peer->fd);
1752 return (bgp_stop(peer));
1753 }
1754
1755 void bgp_fsm_event_update(struct peer *peer, int valid)
1756 {
1757 if (!peer)
1758 return;
1759
1760 switch (peer->status) {
1761 case Idle:
1762 if (valid)
1763 BGP_EVENT_ADD(peer, BGP_Start);
1764 break;
1765 case Connect:
1766 if (!valid) {
1767 BGP_TIMER_OFF(peer->t_connect);
1768 BGP_EVENT_ADD(peer, TCP_fatal_error);
1769 }
1770 break;
1771 case Active:
1772 if (valid) {
1773 BGP_TIMER_OFF(peer->t_connect);
1774 BGP_EVENT_ADD(peer, ConnectRetry_timer_expired);
1775 }
1776 break;
1777 case OpenSent:
1778 case OpenConfirm:
1779 case Established:
1780 if (!valid && (peer->gtsm_hops == 1))
1781 BGP_EVENT_ADD(peer, TCP_fatal_error);
1782 case Clearing:
1783 case Deleted:
1784 default:
1785 break;
1786 }
1787 }
1788
1789 /* Finite State Machine structure */
1790 static const struct {
1791 int (*func)(struct peer *);
1792 int next_state;
1793 } FSM[BGP_STATUS_MAX - 1][BGP_EVENTS_MAX - 1] = {
1794 {
1795 /* Idle state: In Idle state, all events other than BGP_Start is
1796 ignored. With BGP_Start event, finite state machine calls
1797 bgp_start(). */
1798 {bgp_start, Connect}, /* BGP_Start */
1799 {bgp_stop, Idle}, /* BGP_Stop */
1800 {bgp_stop, Idle}, /* TCP_connection_open */
1801 {bgp_stop, Idle}, /* TCP_connection_closed */
1802 {bgp_ignore, Idle}, /* TCP_connection_open_failed */
1803 {bgp_stop, Idle}, /* TCP_fatal_error */
1804 {bgp_ignore, Idle}, /* ConnectRetry_timer_expired */
1805 {bgp_ignore, Idle}, /* Hold_Timer_expired */
1806 {bgp_ignore, Idle}, /* KeepAlive_timer_expired */
1807 {bgp_ignore, Idle}, /* Receive_OPEN_message */
1808 {bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
1809 {bgp_ignore, Idle}, /* Receive_UPDATE_message */
1810 {bgp_ignore, Idle}, /* Receive_NOTIFICATION_message */
1811 {bgp_ignore, Idle}, /* Clearing_Completed */
1812 },
1813 {
1814 /* Connect */
1815 {bgp_ignore, Connect}, /* BGP_Start */
1816 {bgp_stop, Idle}, /* BGP_Stop */
1817 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1818 {bgp_stop, Idle}, /* TCP_connection_closed */
1819 {bgp_connect_fail, Active}, /* TCP_connection_open_failed */
1820 {bgp_connect_fail, Idle}, /* TCP_fatal_error */
1821 {bgp_reconnect, Connect}, /* ConnectRetry_timer_expired */
1822 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1823 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1824 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1825 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1826 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1827 {bgp_stop, Idle}, /* Receive_NOTIFICATION_message */
1828 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1829 },
1830 {
1831 /* Active, */
1832 {bgp_ignore, Active}, /* BGP_Start */
1833 {bgp_stop, Idle}, /* BGP_Stop */
1834 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1835 {bgp_stop, Idle}, /* TCP_connection_closed */
1836 {bgp_ignore, Active}, /* TCP_connection_open_failed */
1837 {bgp_fsm_exeption, Idle}, /* TCP_fatal_error */
1838 {bgp_start, Connect}, /* ConnectRetry_timer_expired */
1839 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1840 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1841 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1842 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1843 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1844 {bgp_fsm_exeption, Idle}, /* Receive_NOTIFICATION_message */
1845 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1846 },
1847 {
1848 /* OpenSent, */
1849 {bgp_ignore, OpenSent}, /* BGP_Start */
1850 {bgp_stop, Idle}, /* BGP_Stop */
1851 {bgp_stop, Active}, /* TCP_connection_open */
1852 {bgp_stop, Active}, /* TCP_connection_closed */
1853 {bgp_stop, Active}, /* TCP_connection_open_failed */
1854 {bgp_stop, Active}, /* TCP_fatal_error */
1855 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1856 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1857 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1858 {bgp_fsm_open, OpenConfirm}, /* Receive_OPEN_message */
1859 {bgp_fsm_event_error, Idle}, /* Receive_KEEPALIVE_message */
1860 {bgp_fsm_event_error, Idle}, /* Receive_UPDATE_message */
1861 {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
1862 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1863 },
1864 {
1865 /* OpenConfirm, */
1866 {bgp_ignore, OpenConfirm}, /* BGP_Start */
1867 {bgp_stop, Idle}, /* BGP_Stop */
1868 {bgp_stop, Idle}, /* TCP_connection_open */
1869 {bgp_stop, Idle}, /* TCP_connection_closed */
1870 {bgp_stop, Idle}, /* TCP_connection_open_failed */
1871 {bgp_stop, Idle}, /* TCP_fatal_error */
1872 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1873 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1874 {bgp_ignore, OpenConfirm}, /* KeepAlive_timer_expired */
1875 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1876 {bgp_establish, Established}, /* Receive_KEEPALIVE_message */
1877 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1878 {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
1879 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1880 },
1881 {
1882 /* Established, */
1883 {bgp_ignore, Established}, /* 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_fsm_holdtime_expire, Clearing}, /* Hold_Timer_expired */
1891 {bgp_ignore, Established}, /* KeepAlive_timer_expired */
1892 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1893 {bgp_fsm_keepalive,
1894 Established}, /* Receive_KEEPALIVE_message */
1895 {bgp_fsm_update, Established}, /* Receive_UPDATE_message */
1896 {bgp_stop_with_error,
1897 Clearing}, /* Receive_NOTIFICATION_message */
1898 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1899 },
1900 {
1901 /* Clearing, */
1902 {bgp_ignore, Clearing}, /* BGP_Start */
1903 {bgp_stop, Clearing}, /* BGP_Stop */
1904 {bgp_stop, Clearing}, /* TCP_connection_open */
1905 {bgp_stop, Clearing}, /* TCP_connection_closed */
1906 {bgp_stop, Clearing}, /* TCP_connection_open_failed */
1907 {bgp_stop, Clearing}, /* TCP_fatal_error */
1908 {bgp_stop, Clearing}, /* ConnectRetry_timer_expired */
1909 {bgp_stop, Clearing}, /* Hold_Timer_expired */
1910 {bgp_stop, Clearing}, /* KeepAlive_timer_expired */
1911 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1912 {bgp_stop, Clearing}, /* Receive_KEEPALIVE_message */
1913 {bgp_stop, Clearing}, /* Receive_UPDATE_message */
1914 {bgp_stop, Clearing}, /* Receive_NOTIFICATION_message */
1915 {bgp_clearing_completed, Idle}, /* Clearing_Completed */
1916 },
1917 {
1918 /* Deleted, */
1919 {bgp_ignore, Deleted}, /* BGP_Start */
1920 {bgp_ignore, Deleted}, /* BGP_Stop */
1921 {bgp_ignore, Deleted}, /* TCP_connection_open */
1922 {bgp_ignore, Deleted}, /* TCP_connection_closed */
1923 {bgp_ignore, Deleted}, /* TCP_connection_open_failed */
1924 {bgp_ignore, Deleted}, /* TCP_fatal_error */
1925 {bgp_ignore, Deleted}, /* ConnectRetry_timer_expired */
1926 {bgp_ignore, Deleted}, /* Hold_Timer_expired */
1927 {bgp_ignore, Deleted}, /* KeepAlive_timer_expired */
1928 {bgp_ignore, Deleted}, /* Receive_OPEN_message */
1929 {bgp_ignore, Deleted}, /* Receive_KEEPALIVE_message */
1930 {bgp_ignore, Deleted}, /* Receive_UPDATE_message */
1931 {bgp_ignore, Deleted}, /* Receive_NOTIFICATION_message */
1932 {bgp_ignore, Deleted}, /* Clearing_Completed */
1933 },
1934 };
1935
1936 /* Execute event process. */
1937 int bgp_event(struct thread *thread)
1938 {
1939 int event;
1940 struct peer *peer;
1941 int ret;
1942
1943 peer = THREAD_ARG(thread);
1944 event = THREAD_VAL(thread);
1945
1946 ret = bgp_event_update(peer, event);
1947
1948 return (ret);
1949 }
1950
1951 int bgp_event_update(struct peer *peer, int event)
1952 {
1953 int next;
1954 int ret = 0;
1955 struct peer *other;
1956 int passive_conn = 0;
1957 int dyn_nbr;
1958
1959 /* default return code */
1960 ret = FSM_PEER_NOOP;
1961
1962 other = peer->doppelganger;
1963 passive_conn =
1964 (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) ? 1 : 0;
1965 dyn_nbr = peer_dynamic_neighbor(peer);
1966
1967 /* Logging this event. */
1968 next = FSM[peer->status - 1][event - 1].next_state;
1969
1970 if (bgp_debug_neighbor_events(peer) && peer->status != next)
1971 zlog_debug("%s [FSM] %s (%s->%s), fd %d", peer->host,
1972 bgp_event_str[event],
1973 lookup_msg(bgp_status_msg, peer->status, NULL),
1974 lookup_msg(bgp_status_msg, next, NULL), peer->fd);
1975
1976 peer->last_event = peer->cur_event;
1977 peer->cur_event = event;
1978
1979 /* Call function. */
1980 if (FSM[peer->status - 1][event - 1].func)
1981 ret = (*(FSM[peer->status - 1][event - 1].func))(peer);
1982
1983 if (ret >= 0) {
1984 if (ret == 1 && next == Established) {
1985 /* The case when doppelganger swap accurred in
1986 bgp_establish.
1987 Update the peer pointer accordingly */
1988 ret = FSM_PEER_TRANSFERRED;
1989 peer = other;
1990 }
1991
1992 /* If status is changed. */
1993 if (next != peer->status) {
1994 bgp_fsm_change_status(peer, next);
1995
1996 /*
1997 * If we're going to ESTABLISHED then we executed a
1998 * peer transfer. In this case we can either return
1999 * FSM_PEER_TRANSITIONED or FSM_PEER_TRANSFERRED.
2000 * Opting for TRANSFERRED since transfer implies
2001 * session establishment.
2002 */
2003 if (ret != FSM_PEER_TRANSFERRED)
2004 ret = FSM_PEER_TRANSITIONED;
2005 }
2006
2007 /* Make sure timer is set. */
2008 bgp_timer_set(peer);
2009
2010 } else {
2011 /*
2012 * If we got a return value of -1, that means there was an
2013 * error, restart the FSM. Since bgp_stop() was called on the
2014 * peer. only a few fields are safe to access here. In any case
2015 * we need to indicate that the peer was stopped in the return
2016 * code.
2017 */
2018 if (!dyn_nbr && !passive_conn && peer->bgp) {
2019 flog_err(
2020 EC_BGP_FSM,
2021 "%s [FSM] Failure handling event %s in state %s, "
2022 "prior events %s, %s, fd %d",
2023 peer->host, bgp_event_str[peer->cur_event],
2024 lookup_msg(bgp_status_msg, peer->status, NULL),
2025 bgp_event_str[peer->last_event],
2026 bgp_event_str[peer->last_major_event],
2027 peer->fd);
2028 bgp_stop(peer);
2029 bgp_fsm_change_status(peer, Idle);
2030 bgp_timer_set(peer);
2031 }
2032 ret = FSM_PEER_STOPPED;
2033 }
2034
2035 return ret;
2036 }
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