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Merge pull request #5686 from qlyoung/fix-bgp-fqdn-capability-leak
[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_status_changed, (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 *const 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 /* Register peer with NHT */
100 static int bgp_peer_reg_with_nht(struct peer *peer)
101 {
102 int connected = 0;
103
104 if (peer->sort == BGP_PEER_EBGP && peer->ttl == BGP_DEFAULT_TTL
105 && !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
106 && !bgp_flag_check(peer->bgp, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
107 connected = 1;
108
109 return bgp_find_or_add_nexthop(
110 peer->bgp, peer->bgp, family2afi(peer->su.sa.sa_family),
111 NULL, peer, connected);
112 }
113
114 static void peer_xfer_stats(struct peer *peer_dst, struct peer *peer_src)
115 {
116 /* Copy stats over. These are only the pre-established state stats */
117 peer_dst->open_in += peer_src->open_in;
118 peer_dst->open_out += peer_src->open_out;
119 peer_dst->keepalive_in += peer_src->keepalive_in;
120 peer_dst->keepalive_out += peer_src->keepalive_out;
121 peer_dst->notify_in += peer_src->notify_in;
122 peer_dst->notify_out += peer_src->notify_out;
123 peer_dst->dynamic_cap_in += peer_src->dynamic_cap_in;
124 peer_dst->dynamic_cap_out += peer_src->dynamic_cap_out;
125 }
126
127 static struct peer *peer_xfer_conn(struct peer *from_peer)
128 {
129 struct peer *peer;
130 afi_t afi;
131 safi_t safi;
132 int fd;
133 int status, pstatus;
134 unsigned char last_evt, last_maj_evt;
135
136 assert(from_peer != NULL);
137
138 peer = from_peer->doppelganger;
139
140 if (!peer || !CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
141 return from_peer;
142
143 /*
144 * Let's check that we are not going to loose known configuration
145 * state based upon doppelganger rules.
146 */
147 FOREACH_AFI_SAFI (afi, safi) {
148 if (from_peer->afc[afi][safi] != peer->afc[afi][safi]) {
149 flog_err(
150 EC_BGP_DOPPELGANGER_CONFIG,
151 "from_peer->afc[%d][%d] is not the same as what we are overwriting",
152 afi, safi);
153 return NULL;
154 }
155 }
156
157 if (bgp_debug_neighbor_events(peer))
158 zlog_debug("%s: peer transfer %p fd %d -> %p fd %d)",
159 from_peer->host, from_peer, from_peer->fd, peer,
160 peer->fd);
161
162 bgp_writes_off(peer);
163 bgp_reads_off(peer);
164 bgp_writes_off(from_peer);
165 bgp_reads_off(from_peer);
166
167 /*
168 * Before exchanging FD remove doppelganger from
169 * keepalive peer hash. It could be possible conf peer
170 * fd is set to -1. If blocked on lock then keepalive
171 * thread can access peer pointer with fd -1.
172 */
173 bgp_keepalives_off(from_peer);
174
175 BGP_TIMER_OFF(peer->t_routeadv);
176 BGP_TIMER_OFF(peer->t_connect);
177 BGP_TIMER_OFF(peer->t_connect_check_r);
178 BGP_TIMER_OFF(peer->t_connect_check_w);
179 BGP_TIMER_OFF(from_peer->t_routeadv);
180 BGP_TIMER_OFF(from_peer->t_connect);
181 BGP_TIMER_OFF(from_peer->t_connect_check_r);
182 BGP_TIMER_OFF(from_peer->t_connect_check_w);
183 BGP_TIMER_OFF(from_peer->t_process_packet);
184
185 /*
186 * At this point in time, it is possible that there are packets pending
187 * on various buffers. Those need to be transferred or dropped,
188 * otherwise we'll get spurious failures during session establishment.
189 */
190 frr_with_mutex(&peer->io_mtx, &from_peer->io_mtx) {
191 fd = peer->fd;
192 peer->fd = from_peer->fd;
193 from_peer->fd = fd;
194
195 stream_fifo_clean(peer->ibuf);
196 stream_fifo_clean(peer->obuf);
197
198 /*
199 * this should never happen, since bgp_process_packet() is the
200 * only task that sets and unsets the current packet and it
201 * runs in our pthread.
202 */
203 if (peer->curr) {
204 flog_err(
205 EC_BGP_PKT_PROCESS,
206 "[%s] Dropping pending packet on connection transfer:",
207 peer->host);
208 /* there used to be a bgp_packet_dump call here, but
209 * that's extremely confusing since there's no way to
210 * identify the packet in MRT dumps or BMP as dropped
211 * due to connection transfer.
212 */
213 stream_free(peer->curr);
214 peer->curr = NULL;
215 }
216
217 // copy each packet from old peer's output queue to new peer
218 while (from_peer->obuf->head)
219 stream_fifo_push(peer->obuf,
220 stream_fifo_pop(from_peer->obuf));
221
222 // copy each packet from old peer's input queue to new peer
223 while (from_peer->ibuf->head)
224 stream_fifo_push(peer->ibuf,
225 stream_fifo_pop(from_peer->ibuf));
226
227 ringbuf_wipe(peer->ibuf_work);
228 ringbuf_copy(peer->ibuf_work, from_peer->ibuf_work,
229 ringbuf_remain(from_peer->ibuf_work));
230 }
231
232 peer->as = from_peer->as;
233 peer->v_holdtime = from_peer->v_holdtime;
234 peer->v_keepalive = from_peer->v_keepalive;
235 peer->v_routeadv = from_peer->v_routeadv;
236 peer->v_gr_restart = from_peer->v_gr_restart;
237 peer->cap = from_peer->cap;
238 status = peer->status;
239 pstatus = peer->ostatus;
240 last_evt = peer->last_event;
241 last_maj_evt = peer->last_major_event;
242 peer->status = from_peer->status;
243 peer->ostatus = from_peer->ostatus;
244 peer->last_event = from_peer->last_event;
245 peer->last_major_event = from_peer->last_major_event;
246 from_peer->status = status;
247 from_peer->ostatus = pstatus;
248 from_peer->last_event = last_evt;
249 from_peer->last_major_event = last_maj_evt;
250 peer->remote_id = from_peer->remote_id;
251 peer->last_reset = from_peer->last_reset;
252
253 if (from_peer->hostname != NULL) {
254 if (peer->hostname) {
255 XFREE(MTYPE_BGP_PEER_HOST, peer->hostname);
256 peer->hostname = NULL;
257 }
258
259 peer->hostname = from_peer->hostname;
260 from_peer->hostname = NULL;
261 }
262
263 if (from_peer->domainname != NULL) {
264 if (peer->domainname) {
265 XFREE(MTYPE_BGP_PEER_HOST, peer->domainname);
266 peer->domainname = NULL;
267 }
268
269 peer->domainname = from_peer->domainname;
270 from_peer->domainname = NULL;
271 }
272
273 FOREACH_AFI_SAFI (afi, safi) {
274 peer->af_flags[afi][safi] = from_peer->af_flags[afi][safi];
275 peer->af_sflags[afi][safi] = from_peer->af_sflags[afi][safi];
276 peer->af_cap[afi][safi] = from_peer->af_cap[afi][safi];
277 peer->afc_nego[afi][safi] = from_peer->afc_nego[afi][safi];
278 peer->afc_adv[afi][safi] = from_peer->afc_adv[afi][safi];
279 peer->afc_recv[afi][safi] = from_peer->afc_recv[afi][safi];
280 peer->orf_plist[afi][safi] = from_peer->orf_plist[afi][safi];
281 }
282
283 if (bgp_getsockname(peer) < 0) {
284 flog_err(
285 EC_LIB_SOCKET,
286 "%%bgp_getsockname() failed for %s peer %s fd %d (from_peer fd %d)",
287 (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)
288 ? "accept"
289 : ""),
290 peer->host, peer->fd, from_peer->fd);
291 bgp_stop(peer);
292 bgp_stop(from_peer);
293 return NULL;
294 }
295 if (from_peer->status > Active) {
296 if (bgp_getsockname(from_peer) < 0) {
297 flog_err(
298 EC_LIB_SOCKET,
299 "%%bgp_getsockname() failed for %s from_peer %s fd %d (peer fd %d)",
300
301 (CHECK_FLAG(from_peer->sflags,
302 PEER_STATUS_ACCEPT_PEER)
303 ? "accept"
304 : ""),
305 from_peer->host, from_peer->fd, peer->fd);
306 bgp_stop(from_peer);
307 from_peer = NULL;
308 }
309 }
310
311
312 // Note: peer_xfer_stats() must be called with I/O turned OFF
313 if (from_peer)
314 peer_xfer_stats(peer, from_peer);
315
316 /* Register peer for NHT. This is to allow RAs to be enabled when
317 * needed, even on a passive connection.
318 */
319 bgp_peer_reg_with_nht(peer);
320
321 bgp_reads_on(peer);
322 bgp_writes_on(peer);
323 thread_add_timer_msec(bm->master, bgp_process_packet, peer, 0,
324 &peer->t_process_packet);
325
326 return (peer);
327 }
328
329 /* Hook function called after bgp event is occered. And vty's
330 neighbor command invoke this function after making neighbor
331 structure. */
332 void bgp_timer_set(struct peer *peer)
333 {
334 switch (peer->status) {
335 case Idle:
336 /* First entry point of peer's finite state machine. In Idle
337 status start timer is on unless peer is shutdown or peer is
338 inactive. All other timer must be turned off */
339 if (BGP_PEER_START_SUPPRESSED(peer) || !peer_active(peer)
340 || (peer->bgp->inst_type != BGP_INSTANCE_TYPE_VIEW &&
341 peer->bgp->vrf_id == VRF_UNKNOWN)) {
342 BGP_TIMER_OFF(peer->t_start);
343 } else {
344 BGP_TIMER_ON(peer->t_start, bgp_start_timer,
345 peer->v_start);
346 }
347 BGP_TIMER_OFF(peer->t_connect);
348 BGP_TIMER_OFF(peer->t_holdtime);
349 bgp_keepalives_off(peer);
350 BGP_TIMER_OFF(peer->t_routeadv);
351 break;
352
353 case Connect:
354 /* After start timer is expired, the peer moves to Connect
355 status. Make sure start timer is off and connect timer is
356 on. */
357 BGP_TIMER_OFF(peer->t_start);
358 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
359 peer->v_connect);
360 BGP_TIMER_OFF(peer->t_holdtime);
361 bgp_keepalives_off(peer);
362 BGP_TIMER_OFF(peer->t_routeadv);
363 break;
364
365 case Active:
366 /* Active is waiting connection from remote peer. And if
367 connect timer is expired, change status to Connect. */
368 BGP_TIMER_OFF(peer->t_start);
369 /* If peer is passive mode, do not set connect timer. */
370 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)
371 || CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
372 BGP_TIMER_OFF(peer->t_connect);
373 } else {
374 BGP_TIMER_ON(peer->t_connect, bgp_connect_timer,
375 peer->v_connect);
376 }
377 BGP_TIMER_OFF(peer->t_holdtime);
378 bgp_keepalives_off(peer);
379 BGP_TIMER_OFF(peer->t_routeadv);
380 break;
381
382 case OpenSent:
383 /* OpenSent status. */
384 BGP_TIMER_OFF(peer->t_start);
385 BGP_TIMER_OFF(peer->t_connect);
386 if (peer->v_holdtime != 0) {
387 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
388 peer->v_holdtime);
389 } else {
390 BGP_TIMER_OFF(peer->t_holdtime);
391 }
392 bgp_keepalives_off(peer);
393 BGP_TIMER_OFF(peer->t_routeadv);
394 break;
395
396 case OpenConfirm:
397 /* OpenConfirm status. */
398 BGP_TIMER_OFF(peer->t_start);
399 BGP_TIMER_OFF(peer->t_connect);
400
401 /* If the negotiated Hold Time value is zero, then the Hold Time
402 timer and KeepAlive timers are not started. */
403 if (peer->v_holdtime == 0) {
404 BGP_TIMER_OFF(peer->t_holdtime);
405 bgp_keepalives_off(peer);
406 } else {
407 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
408 peer->v_holdtime);
409 bgp_keepalives_on(peer);
410 }
411 BGP_TIMER_OFF(peer->t_routeadv);
412 break;
413
414 case Established:
415 /* In Established status start and connect timer is turned
416 off. */
417 BGP_TIMER_OFF(peer->t_start);
418 BGP_TIMER_OFF(peer->t_connect);
419
420 /* Same as OpenConfirm, if holdtime is zero then both holdtime
421 and keepalive must be turned off. */
422 if (peer->v_holdtime == 0) {
423 BGP_TIMER_OFF(peer->t_holdtime);
424 bgp_keepalives_off(peer);
425 } else {
426 BGP_TIMER_ON(peer->t_holdtime, bgp_holdtime_timer,
427 peer->v_holdtime);
428 bgp_keepalives_on(peer);
429 }
430 break;
431 case Deleted:
432 BGP_TIMER_OFF(peer->t_gr_restart);
433 BGP_TIMER_OFF(peer->t_gr_stale);
434 BGP_TIMER_OFF(peer->t_pmax_restart);
435 /* fallthru */
436 case Clearing:
437 BGP_TIMER_OFF(peer->t_start);
438 BGP_TIMER_OFF(peer->t_connect);
439 BGP_TIMER_OFF(peer->t_holdtime);
440 bgp_keepalives_off(peer);
441 BGP_TIMER_OFF(peer->t_routeadv);
442 break;
443 }
444 }
445
446 /* BGP start timer. This function set BGP_Start event to thread value
447 and process event. */
448 static int bgp_start_timer(struct thread *thread)
449 {
450 struct peer *peer;
451
452 peer = THREAD_ARG(thread);
453 peer->t_start = NULL;
454
455 if (bgp_debug_neighbor_events(peer))
456 zlog_debug("%s [FSM] Timer (start timer expire).", peer->host);
457
458 THREAD_VAL(thread) = BGP_Start;
459 bgp_event(thread); /* bgp_event unlocks peer */
460
461 return 0;
462 }
463
464 /* BGP connect retry timer. */
465 static int bgp_connect_timer(struct thread *thread)
466 {
467 struct peer *peer;
468 int ret;
469
470 peer = THREAD_ARG(thread);
471
472 assert(!peer->t_write);
473 assert(!peer->t_read);
474
475 peer->t_connect = NULL;
476
477 if (bgp_debug_neighbor_events(peer))
478 zlog_debug("%s [FSM] Timer (connect timer expire)", peer->host);
479
480 if (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) {
481 bgp_stop(peer);
482 ret = -1;
483 } else {
484 THREAD_VAL(thread) = ConnectRetry_timer_expired;
485 bgp_event(thread); /* bgp_event unlocks peer */
486 ret = 0;
487 }
488
489 return ret;
490 }
491
492 /* BGP holdtime timer. */
493 static int bgp_holdtime_timer(struct thread *thread)
494 {
495 struct peer *peer;
496
497 peer = THREAD_ARG(thread);
498 peer->t_holdtime = NULL;
499
500 if (bgp_debug_neighbor_events(peer))
501 zlog_debug("%s [FSM] Timer (holdtime timer expire)",
502 peer->host);
503
504 THREAD_VAL(thread) = Hold_Timer_expired;
505 bgp_event(thread); /* bgp_event unlocks peer */
506
507 return 0;
508 }
509
510 int bgp_routeadv_timer(struct thread *thread)
511 {
512 struct peer *peer;
513
514 peer = THREAD_ARG(thread);
515 peer->t_routeadv = NULL;
516
517 if (bgp_debug_neighbor_events(peer))
518 zlog_debug("%s [FSM] Timer (routeadv timer expire)",
519 peer->host);
520
521 peer->synctime = bgp_clock();
522
523 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets, peer, 0,
524 &peer->t_generate_updgrp_packets);
525
526 /* MRAI timer will be started again when FIFO is built, no need to
527 * do it here.
528 */
529 return 0;
530 }
531
532 /* BGP Peer Down Cause */
533 const char *const peer_down_str[] = {"",
534 "Router ID changed",
535 "Remote AS changed",
536 "Local AS change",
537 "Cluster ID changed",
538 "Confederation identifier changed",
539 "Confederation peer changed",
540 "RR client config change",
541 "RS client config change",
542 "Update source change",
543 "Address family activated",
544 "Admin. shutdown",
545 "User reset",
546 "BGP Notification received",
547 "BGP Notification send",
548 "Peer closed the session",
549 "Neighbor deleted",
550 "Peer-group add member",
551 "Peer-group delete member",
552 "Capability changed",
553 "Passive config change",
554 "Multihop config change",
555 "NSF peer closed the session",
556 "Intf peering v6only config change",
557 "BFD down received",
558 "Interface down",
559 "Neighbor address lost",
560 "Waiting for NHT",
561 "Waiting for Peer IPv6 LLA",
562 "Waiting for VRF to be initialized",
563 "No AFI/SAFI activated for peer"};
564
565 static int bgp_graceful_restart_timer_expire(struct thread *thread)
566 {
567 struct peer *peer;
568 afi_t afi;
569 safi_t safi;
570
571 peer = THREAD_ARG(thread);
572 peer->t_gr_restart = NULL;
573
574 /* NSF delete stale route */
575 for (afi = AFI_IP; afi < AFI_MAX; afi++)
576 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
577 if (peer->nsf[afi][safi])
578 bgp_clear_stale_route(peer, afi, safi);
579
580 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
581 BGP_TIMER_OFF(peer->t_gr_stale);
582
583 if (bgp_debug_neighbor_events(peer)) {
584 zlog_debug("%s graceful restart timer expired", peer->host);
585 zlog_debug("%s graceful restart stalepath timer stopped",
586 peer->host);
587 }
588
589 bgp_timer_set(peer);
590
591 return 0;
592 }
593
594 static int bgp_graceful_stale_timer_expire(struct thread *thread)
595 {
596 struct peer *peer;
597 afi_t afi;
598 safi_t safi;
599
600 peer = THREAD_ARG(thread);
601 peer->t_gr_stale = NULL;
602
603 if (bgp_debug_neighbor_events(peer))
604 zlog_debug("%s graceful restart stalepath timer expired",
605 peer->host);
606
607 /* NSF delete stale route */
608 for (afi = AFI_IP; afi < AFI_MAX; afi++)
609 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++)
610 if (peer->nsf[afi][safi])
611 bgp_clear_stale_route(peer, afi, safi);
612
613 return 0;
614 }
615
616 static int bgp_update_delay_applicable(struct bgp *bgp)
617 {
618 /* update_delay_over flag should be reset (set to 0) for any new
619 applicability of the update-delay during BGP process lifetime.
620 And it should be set after an occurence of the update-delay is
621 over)*/
622 if (!bgp->update_delay_over)
623 return 1;
624
625 return 0;
626 }
627
628 int bgp_update_delay_active(struct bgp *bgp)
629 {
630 if (bgp->t_update_delay)
631 return 1;
632
633 return 0;
634 }
635
636 int bgp_update_delay_configured(struct bgp *bgp)
637 {
638 if (bgp->v_update_delay)
639 return 1;
640
641 return 0;
642 }
643
644 /* Do the post-processing needed when bgp comes out of the read-only mode
645 on ending the update delay. */
646 void bgp_update_delay_end(struct bgp *bgp)
647 {
648 THREAD_TIMER_OFF(bgp->t_update_delay);
649 THREAD_TIMER_OFF(bgp->t_establish_wait);
650
651 /* Reset update-delay related state */
652 bgp->update_delay_over = 1;
653 bgp->established = 0;
654 bgp->restarted_peers = 0;
655 bgp->implicit_eors = 0;
656 bgp->explicit_eors = 0;
657
658 quagga_timestamp(3, bgp->update_delay_end_time,
659 sizeof(bgp->update_delay_end_time));
660
661 /*
662 * Add an end-of-initial-update marker to the main process queues so
663 * that
664 * the route advertisement timer for the peers can be started. Also set
665 * the zebra and peer update hold flags. These flags are used to achieve
666 * three stages in the update-delay post processing:
667 * 1. Finish best-path selection for all the prefixes held on the
668 * queues.
669 * (routes in BGP are updated, and peers sync queues are populated
670 * too)
671 * 2. As the eoiu mark is reached in the bgp process routine, ship all
672 * the
673 * routes to zebra. With that zebra should see updates from BGP
674 * close
675 * to each other.
676 * 3. Unblock the peer update writes. With that peer update packing
677 * with
678 * the prefixes should be at its maximum.
679 */
680 bgp_add_eoiu_mark(bgp);
681 bgp->main_zebra_update_hold = 1;
682 bgp->main_peers_update_hold = 1;
683
684 /* Resume the queue processing. This should trigger the event that would
685 take
686 care of processing any work that was queued during the read-only
687 mode. */
688 work_queue_unplug(bm->process_main_queue);
689 }
690
691 /**
692 * see bgp_fsm.h
693 */
694 void bgp_start_routeadv(struct bgp *bgp)
695 {
696 struct listnode *node, *nnode;
697 struct peer *peer;
698
699 zlog_info("bgp_start_routeadv(), update hold status %d",
700 bgp->main_peers_update_hold);
701
702 if (bgp->main_peers_update_hold)
703 return;
704
705 quagga_timestamp(3, bgp->update_delay_peers_resume_time,
706 sizeof(bgp->update_delay_peers_resume_time));
707
708 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer)) {
709 if (peer->status != Established)
710 continue;
711 BGP_TIMER_OFF(peer->t_routeadv);
712 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
713 }
714 }
715
716 /**
717 * see bgp_fsm.h
718 */
719 void bgp_adjust_routeadv(struct peer *peer)
720 {
721 time_t nowtime = bgp_clock();
722 double diff;
723 unsigned long remain;
724
725 /* Bypass checks for special case of MRAI being 0 */
726 if (peer->v_routeadv == 0) {
727 /* Stop existing timer, just in case it is running for a
728 * different
729 * duration and schedule write thread immediately.
730 */
731 if (peer->t_routeadv)
732 BGP_TIMER_OFF(peer->t_routeadv);
733
734 peer->synctime = bgp_clock();
735 thread_add_timer_msec(bm->master, bgp_generate_updgrp_packets,
736 peer, 0,
737 &peer->t_generate_updgrp_packets);
738 return;
739 }
740
741
742 /*
743 * CASE I:
744 * If the last update was written more than MRAI back, expire the timer
745 * instantly so that we can send the update out sooner.
746 *
747 * <------- MRAI --------->
748 * |-----------------|-----------------------|
749 * <------------- m ------------>
750 * ^ ^ ^
751 * | | |
752 * | | current time
753 * | timer start
754 * last write
755 *
756 * m > MRAI
757 */
758 diff = difftime(nowtime, peer->last_update);
759 if (diff > (double)peer->v_routeadv) {
760 BGP_TIMER_OFF(peer->t_routeadv);
761 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
762 return;
763 }
764
765 /*
766 * CASE II:
767 * - Find when to expire the MRAI timer.
768 * If MRAI timer is not active, assume we can start it now.
769 *
770 * <------- MRAI --------->
771 * |------------|-----------------------|
772 * <-------- m ----------><----- r ----->
773 * ^ ^ ^
774 * | | |
775 * | | current time
776 * | timer start
777 * last write
778 *
779 * (MRAI - m) < r
780 */
781 if (peer->t_routeadv)
782 remain = thread_timer_remain_second(peer->t_routeadv);
783 else
784 remain = peer->v_routeadv;
785 diff = peer->v_routeadv - diff;
786 if (diff <= (double)remain) {
787 BGP_TIMER_OFF(peer->t_routeadv);
788 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, diff);
789 }
790 }
791
792 static int bgp_maxmed_onstartup_applicable(struct bgp *bgp)
793 {
794 if (!bgp->maxmed_onstartup_over)
795 return 1;
796
797 return 0;
798 }
799
800 int bgp_maxmed_onstartup_configured(struct bgp *bgp)
801 {
802 if (bgp->v_maxmed_onstartup != BGP_MAXMED_ONSTARTUP_UNCONFIGURED)
803 return 1;
804
805 return 0;
806 }
807
808 int bgp_maxmed_onstartup_active(struct bgp *bgp)
809 {
810 if (bgp->t_maxmed_onstartup)
811 return 1;
812
813 return 0;
814 }
815
816 void bgp_maxmed_update(struct bgp *bgp)
817 {
818 uint8_t maxmed_active;
819 uint32_t maxmed_value;
820
821 if (bgp->v_maxmed_admin) {
822 maxmed_active = 1;
823 maxmed_value = bgp->maxmed_admin_value;
824 } else if (bgp->t_maxmed_onstartup) {
825 maxmed_active = 1;
826 maxmed_value = bgp->maxmed_onstartup_value;
827 } else {
828 maxmed_active = 0;
829 maxmed_value = BGP_MAXMED_VALUE_DEFAULT;
830 }
831
832 if (bgp->maxmed_active != maxmed_active
833 || bgp->maxmed_value != maxmed_value) {
834 bgp->maxmed_active = maxmed_active;
835 bgp->maxmed_value = maxmed_value;
836
837 update_group_announce(bgp);
838 }
839 }
840
841 /* The maxmed onstartup timer expiry callback. */
842 static int bgp_maxmed_onstartup_timer(struct thread *thread)
843 {
844 struct bgp *bgp;
845
846 zlog_info("Max med on startup ended - timer expired.");
847
848 bgp = THREAD_ARG(thread);
849 THREAD_TIMER_OFF(bgp->t_maxmed_onstartup);
850 bgp->maxmed_onstartup_over = 1;
851
852 bgp_maxmed_update(bgp);
853
854 return 0;
855 }
856
857 static void bgp_maxmed_onstartup_begin(struct bgp *bgp)
858 {
859 /* Applicable only once in the process lifetime on the startup */
860 if (bgp->maxmed_onstartup_over)
861 return;
862
863 zlog_info("Begin maxmed onstartup mode - timer %d seconds",
864 bgp->v_maxmed_onstartup);
865
866 thread_add_timer(bm->master, bgp_maxmed_onstartup_timer, bgp,
867 bgp->v_maxmed_onstartup, &bgp->t_maxmed_onstartup);
868
869 if (!bgp->v_maxmed_admin) {
870 bgp->maxmed_active = 1;
871 bgp->maxmed_value = bgp->maxmed_onstartup_value;
872 }
873
874 /* Route announce to all peers should happen after this in
875 * bgp_establish() */
876 }
877
878 static void bgp_maxmed_onstartup_process_status_change(struct peer *peer)
879 {
880 if (peer->status == Established && !peer->bgp->established) {
881 bgp_maxmed_onstartup_begin(peer->bgp);
882 }
883 }
884
885 /* The update delay timer expiry callback. */
886 static int bgp_update_delay_timer(struct thread *thread)
887 {
888 struct bgp *bgp;
889
890 zlog_info("Update delay ended - timer expired.");
891
892 bgp = THREAD_ARG(thread);
893 THREAD_TIMER_OFF(bgp->t_update_delay);
894 bgp_update_delay_end(bgp);
895
896 return 0;
897 }
898
899 /* The establish wait timer expiry callback. */
900 static int bgp_establish_wait_timer(struct thread *thread)
901 {
902 struct bgp *bgp;
903
904 zlog_info("Establish wait - timer expired.");
905
906 bgp = THREAD_ARG(thread);
907 THREAD_TIMER_OFF(bgp->t_establish_wait);
908 bgp_check_update_delay(bgp);
909
910 return 0;
911 }
912
913 /* Steps to begin the update delay:
914 - initialize queues if needed
915 - stop the queue processing
916 - start the timer */
917 static void bgp_update_delay_begin(struct bgp *bgp)
918 {
919 struct listnode *node, *nnode;
920 struct peer *peer;
921
922 /* Stop the processing of queued work. Enqueue shall continue */
923 work_queue_plug(bm->process_main_queue);
924
925 for (ALL_LIST_ELEMENTS(bgp->peer, node, nnode, peer))
926 peer->update_delay_over = 0;
927
928 /* Start the update-delay timer */
929 thread_add_timer(bm->master, bgp_update_delay_timer, bgp,
930 bgp->v_update_delay, &bgp->t_update_delay);
931
932 if (bgp->v_establish_wait != bgp->v_update_delay)
933 thread_add_timer(bm->master, bgp_establish_wait_timer, bgp,
934 bgp->v_establish_wait, &bgp->t_establish_wait);
935
936 quagga_timestamp(3, bgp->update_delay_begin_time,
937 sizeof(bgp->update_delay_begin_time));
938 }
939
940 static void bgp_update_delay_process_status_change(struct peer *peer)
941 {
942 if (peer->status == Established) {
943 if (!peer->bgp->established++) {
944 bgp_update_delay_begin(peer->bgp);
945 zlog_info(
946 "Begin read-only mode - update-delay timer %d seconds",
947 peer->bgp->v_update_delay);
948 }
949 if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_BIT_RCV))
950 bgp_update_restarted_peers(peer);
951 }
952 if (peer->ostatus == Established
953 && bgp_update_delay_active(peer->bgp)) {
954 /* Adjust the update-delay state to account for this flap.
955 NOTE: Intentionally skipping adjusting implicit_eors or
956 explicit_eors
957 counters. Extra sanity check in bgp_check_update_delay()
958 should
959 be enough to take care of any additive discrepancy in bgp eor
960 counters */
961 peer->bgp->established--;
962 peer->update_delay_over = 0;
963 }
964 }
965
966 /* Called after event occurred, this function change status and reset
967 read/write and timer thread. */
968 void bgp_fsm_change_status(struct peer *peer, int status)
969 {
970 struct bgp *bgp;
971 uint32_t peer_count;
972
973 bgp = peer->bgp;
974 peer_count = bgp->established_peers;
975
976 if (status == Established)
977 bgp->established_peers++;
978 else if ((peer->status == Established) && (status != Established))
979 bgp->established_peers--;
980
981 if (bgp_debug_neighbor_events(peer)) {
982 struct vrf *vrf = vrf_lookup_by_id(bgp->vrf_id);
983
984 zlog_debug("%s : vrf %s(%u), Status: %s established_peers %u", __func__,
985 vrf ? vrf->name : "Unknown", bgp->vrf_id,
986 lookup_msg(bgp_status_msg, status, NULL),
987 bgp->established_peers);
988 }
989
990 /* Set to router ID to the value provided by RIB if there are no peers
991 * in the established state and peer count did not change
992 */
993 if ((peer_count != bgp->established_peers) &&
994 (bgp->established_peers == 0))
995 bgp_router_id_zebra_bump(bgp->vrf_id, NULL);
996
997 /* Transition into Clearing or Deleted must /always/ clear all routes..
998 * (and must do so before actually changing into Deleted..
999 */
1000 if (status >= Clearing) {
1001 bgp_clear_route_all(peer);
1002
1003 /* If no route was queued for the clear-node processing,
1004 * generate the
1005 * completion event here. This is needed because if there are no
1006 * routes
1007 * to trigger the background clear-node thread, the event won't
1008 * get
1009 * generated and the peer would be stuck in Clearing. Note that
1010 * this
1011 * event is for the peer and helps the peer transition out of
1012 * Clearing
1013 * state; it should not be generated per (AFI,SAFI). The event
1014 * is
1015 * directly posted here without calling clear_node_complete() as
1016 * we
1017 * shouldn't do an extra unlock. This event will get processed
1018 * after
1019 * the state change that happens below, so peer will be in
1020 * Clearing
1021 * (or Deleted).
1022 */
1023 if (!work_queue_is_scheduled(peer->clear_node_queue))
1024 BGP_EVENT_ADD(peer, Clearing_Completed);
1025 }
1026
1027 /* Preserve old status and change into new status. */
1028 peer->ostatus = peer->status;
1029 peer->status = status;
1030
1031 /* Save event that caused status change. */
1032 peer->last_major_event = peer->cur_event;
1033
1034 /* Operations after status change */
1035 hook_call(peer_status_changed, peer);
1036
1037 if (status == Established)
1038 UNSET_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER);
1039
1040 /* If max-med processing is applicable, do the necessary. */
1041 if (status == Established) {
1042 if (bgp_maxmed_onstartup_configured(peer->bgp)
1043 && bgp_maxmed_onstartup_applicable(peer->bgp))
1044 bgp_maxmed_onstartup_process_status_change(peer);
1045 else
1046 peer->bgp->maxmed_onstartup_over = 1;
1047 }
1048
1049 /* If update-delay processing is applicable, do the necessary. */
1050 if (bgp_update_delay_configured(peer->bgp)
1051 && bgp_update_delay_applicable(peer->bgp))
1052 bgp_update_delay_process_status_change(peer);
1053
1054 if (bgp_debug_neighbor_events(peer))
1055 zlog_debug("%s went from %s to %s", peer->host,
1056 lookup_msg(bgp_status_msg, peer->ostatus, NULL),
1057 lookup_msg(bgp_status_msg, peer->status, NULL));
1058 }
1059
1060 /* Flush the event queue and ensure the peer is shut down */
1061 static int bgp_clearing_completed(struct peer *peer)
1062 {
1063 int rc = bgp_stop(peer);
1064
1065 if (rc >= 0)
1066 BGP_EVENT_FLUSH(peer);
1067
1068 return rc;
1069 }
1070
1071 /* Administrative BGP peer stop event. */
1072 /* May be called multiple times for the same peer */
1073 int bgp_stop(struct peer *peer)
1074 {
1075 afi_t afi;
1076 safi_t safi;
1077 char orf_name[BUFSIZ];
1078 int ret = 0;
1079
1080 if (peer_dynamic_neighbor(peer)
1081 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1082 if (bgp_debug_neighbor_events(peer))
1083 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1084 peer_delete(peer);
1085 return -1;
1086 }
1087
1088 /* Can't do this in Clearing; events are used for state transitions */
1089 if (peer->status != Clearing) {
1090 /* Delete all existing events of the peer */
1091 BGP_EVENT_FLUSH(peer);
1092 }
1093
1094 /* Increment Dropped count. */
1095 if (peer->status == Established) {
1096 peer->dropped++;
1097
1098 /* bgp log-neighbor-changes of neighbor Down */
1099 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1100 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1101 zlog_info(
1102 "%%ADJCHANGE: neighbor %s(%s) in vrf %s Down %s",
1103 peer->host,
1104 (peer->hostname) ? peer->hostname : "Unknown",
1105 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1106 ? vrf->name
1107 : VRF_DEFAULT_NAME)
1108 : "",
1109 peer_down_str[(int)peer->last_reset]);
1110 }
1111
1112 /* graceful restart */
1113 if (peer->t_gr_stale) {
1114 BGP_TIMER_OFF(peer->t_gr_stale);
1115 if (bgp_debug_neighbor_events(peer))
1116 zlog_debug(
1117 "%s graceful restart stalepath timer stopped",
1118 peer->host);
1119 }
1120 if (CHECK_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT)) {
1121 if (bgp_debug_neighbor_events(peer)) {
1122 zlog_debug(
1123 "%s graceful restart timer started for %d sec",
1124 peer->host, peer->v_gr_restart);
1125 zlog_debug(
1126 "%s graceful restart stalepath timer started for %d sec",
1127 peer->host, peer->bgp->stalepath_time);
1128 }
1129 BGP_TIMER_ON(peer->t_gr_restart,
1130 bgp_graceful_restart_timer_expire,
1131 peer->v_gr_restart);
1132 BGP_TIMER_ON(peer->t_gr_stale,
1133 bgp_graceful_stale_timer_expire,
1134 peer->bgp->stalepath_time);
1135 } else {
1136 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1137
1138 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1139 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN;
1140 safi++)
1141 peer->nsf[afi][safi] = 0;
1142 }
1143
1144 /* set last reset time */
1145 peer->resettime = peer->uptime = bgp_clock();
1146
1147 if (BGP_DEBUG(update_groups, UPDATE_GROUPS))
1148 zlog_debug("%s remove from all update group",
1149 peer->host);
1150 update_group_remove_peer_afs(peer);
1151
1152 hook_call(peer_backward_transition, peer);
1153
1154 /* Reset peer synctime */
1155 peer->synctime = 0;
1156 }
1157
1158 /* stop keepalives */
1159 bgp_keepalives_off(peer);
1160
1161 /* Stop read and write threads. */
1162 bgp_writes_off(peer);
1163 bgp_reads_off(peer);
1164
1165 THREAD_OFF(peer->t_connect_check_r);
1166 THREAD_OFF(peer->t_connect_check_w);
1167
1168 /* Stop all timers. */
1169 BGP_TIMER_OFF(peer->t_start);
1170 BGP_TIMER_OFF(peer->t_connect);
1171 BGP_TIMER_OFF(peer->t_holdtime);
1172 BGP_TIMER_OFF(peer->t_routeadv);
1173
1174 /* Clear input and output buffer. */
1175 frr_with_mutex(&peer->io_mtx) {
1176 if (peer->ibuf)
1177 stream_fifo_clean(peer->ibuf);
1178 if (peer->obuf)
1179 stream_fifo_clean(peer->obuf);
1180
1181 if (peer->ibuf_work)
1182 ringbuf_wipe(peer->ibuf_work);
1183 if (peer->obuf_work)
1184 stream_reset(peer->obuf_work);
1185
1186 if (peer->curr) {
1187 stream_free(peer->curr);
1188 peer->curr = NULL;
1189 }
1190 }
1191
1192 /* Close of file descriptor. */
1193 if (peer->fd >= 0) {
1194 close(peer->fd);
1195 peer->fd = -1;
1196 }
1197
1198 FOREACH_AFI_SAFI (afi, safi) {
1199 /* Reset all negotiated variables */
1200 peer->afc_nego[afi][safi] = 0;
1201 peer->afc_adv[afi][safi] = 0;
1202 peer->afc_recv[afi][safi] = 0;
1203
1204 /* peer address family capability flags*/
1205 peer->af_cap[afi][safi] = 0;
1206
1207 /* peer address family status flags*/
1208 peer->af_sflags[afi][safi] = 0;
1209
1210 /* Received ORF prefix-filter */
1211 peer->orf_plist[afi][safi] = NULL;
1212
1213 if ((peer->status == OpenConfirm)
1214 || (peer->status == Established)) {
1215 /* ORF received prefix-filter pnt */
1216 sprintf(orf_name, "%s.%d.%d", peer->host, afi, safi);
1217 prefix_bgp_orf_remove_all(afi, orf_name);
1218 }
1219 }
1220
1221 /* Reset keepalive and holdtime */
1222 if (CHECK_FLAG(peer->flags, PEER_FLAG_TIMER)) {
1223 peer->v_keepalive = peer->keepalive;
1224 peer->v_holdtime = peer->holdtime;
1225 } else {
1226 peer->v_keepalive = peer->bgp->default_keepalive;
1227 peer->v_holdtime = peer->bgp->default_holdtime;
1228 }
1229
1230 peer->update_time = 0;
1231
1232 /* Until we are sure that there is no problem about prefix count
1233 this should be commented out.*/
1234 #if 0
1235 /* Reset prefix count */
1236 peer->pcount[AFI_IP][SAFI_UNICAST] = 0;
1237 peer->pcount[AFI_IP][SAFI_MULTICAST] = 0;
1238 peer->pcount[AFI_IP][SAFI_LABELED_UNICAST] = 0;
1239 peer->pcount[AFI_IP][SAFI_MPLS_VPN] = 0;
1240 peer->pcount[AFI_IP6][SAFI_UNICAST] = 0;
1241 peer->pcount[AFI_IP6][SAFI_MULTICAST] = 0;
1242 peer->pcount[AFI_IP6][SAFI_LABELED_UNICAST] = 0;
1243 #endif /* 0 */
1244
1245 if (!CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE)
1246 && !(CHECK_FLAG(peer->flags, PEER_FLAG_DELETE))) {
1247 peer_delete(peer);
1248 ret = -1;
1249 } else {
1250 bgp_peer_conf_if_to_su_update(peer);
1251 }
1252
1253 return ret;
1254 }
1255
1256 /* BGP peer is stoped by the error. */
1257 static int bgp_stop_with_error(struct peer *peer)
1258 {
1259 /* Double start timer. */
1260 peer->v_start *= 2;
1261
1262 /* Overflow check. */
1263 if (peer->v_start >= (60 * 2))
1264 peer->v_start = (60 * 2);
1265
1266 if (peer_dynamic_neighbor(peer)) {
1267 if (bgp_debug_neighbor_events(peer))
1268 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1269 peer_delete(peer);
1270 return -1;
1271 }
1272
1273 return (bgp_stop(peer));
1274 }
1275
1276
1277 /* something went wrong, send notify and tear down */
1278 static int bgp_stop_with_notify(struct peer *peer, uint8_t code,
1279 uint8_t sub_code)
1280 {
1281 /* Send notify to remote peer */
1282 bgp_notify_send(peer, code, sub_code);
1283
1284 if (peer_dynamic_neighbor(peer)) {
1285 if (bgp_debug_neighbor_events(peer))
1286 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1287 peer_delete(peer);
1288 return -1;
1289 }
1290
1291 /* Clear start timer value to default. */
1292 peer->v_start = BGP_INIT_START_TIMER;
1293
1294 return (bgp_stop(peer));
1295 }
1296
1297 /**
1298 * Determines whether a TCP session has successfully established for a peer and
1299 * events as appropriate.
1300 *
1301 * This function is called when setting up a new session. After connect() is
1302 * called on the peer's socket (in bgp_start()), the fd is passed to poll()
1303 * to wait for connection success or failure. When poll() returns, this
1304 * function is called to evaluate the result.
1305 *
1306 * Due to differences in behavior of poll() on Linux and BSD - specifically,
1307 * the value of .revents in the case of a closed connection - this function is
1308 * scheduled both for a read and a write event. The write event is triggered
1309 * when the connection is established. A read event is triggered when the
1310 * connection is closed. Thus we need to cancel whichever one did not occur.
1311 */
1312 static int bgp_connect_check(struct thread *thread)
1313 {
1314 int status;
1315 socklen_t slen;
1316 int ret;
1317 struct peer *peer;
1318
1319 peer = THREAD_ARG(thread);
1320 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1321 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1322 assert(!peer->t_read);
1323 assert(!peer->t_write);
1324
1325 THREAD_OFF(peer->t_connect_check_r);
1326 THREAD_OFF(peer->t_connect_check_w);
1327
1328 /* Check file descriptor. */
1329 slen = sizeof(status);
1330 ret = getsockopt(peer->fd, SOL_SOCKET, SO_ERROR, (void *)&status,
1331 &slen);
1332
1333 /* If getsockopt is fail, this is fatal error. */
1334 if (ret < 0) {
1335 zlog_err("can't get sockopt for nonblocking connect: %d(%s)",
1336 errno, safe_strerror(errno));
1337 BGP_EVENT_ADD(peer, TCP_fatal_error);
1338 return -1;
1339 }
1340
1341 /* When status is 0 then TCP connection is established. */
1342 if (status == 0) {
1343 BGP_EVENT_ADD(peer, TCP_connection_open);
1344 return 1;
1345 } else {
1346 if (bgp_debug_neighbor_events(peer))
1347 zlog_debug("%s [Event] Connect failed %d(%s)",
1348 peer->host, status, safe_strerror(status));
1349 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1350 return 0;
1351 }
1352 }
1353
1354 /* TCP connection open. Next we send open message to remote peer. And
1355 add read thread for reading open message. */
1356 static int bgp_connect_success(struct peer *peer)
1357 {
1358 if (peer->fd < 0) {
1359 flog_err(EC_BGP_CONNECT,
1360 "bgp_connect_success peer's fd is negative value %d",
1361 peer->fd);
1362 bgp_stop(peer);
1363 return -1;
1364 }
1365
1366 if (bgp_getsockname(peer) < 0) {
1367 flog_err_sys(EC_LIB_SOCKET,
1368 "%s: bgp_getsockname(): failed for peer %s, fd %d",
1369 __FUNCTION__, peer->host, peer->fd);
1370 bgp_notify_send(
1371 peer, BGP_NOTIFY_FSM_ERR,
1372 BGP_NOTIFY_SUBCODE_UNSPECIFIC); /* internal error */
1373 bgp_writes_on(peer);
1374 return -1;
1375 }
1376
1377 bgp_reads_on(peer);
1378
1379 if (bgp_debug_neighbor_events(peer)) {
1380 char buf1[SU_ADDRSTRLEN];
1381
1382 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER))
1383 zlog_debug("%s open active, local address %s",
1384 peer->host,
1385 sockunion2str(peer->su_local, buf1,
1386 SU_ADDRSTRLEN));
1387 else
1388 zlog_debug("%s passive open", peer->host);
1389 }
1390
1391 bgp_open_send(peer);
1392
1393 return 0;
1394 }
1395
1396 /* TCP connect fail */
1397 static int bgp_connect_fail(struct peer *peer)
1398 {
1399 if (peer_dynamic_neighbor(peer)) {
1400 if (bgp_debug_neighbor_events(peer))
1401 zlog_debug("%s (dynamic neighbor) deleted", peer->host);
1402 peer_delete(peer);
1403 return -1;
1404 }
1405
1406 return (bgp_stop(peer));
1407 }
1408
1409 /* This function is the first starting point of all BGP connection. It
1410 try to connect to remote peer with non-blocking IO. */
1411 int bgp_start(struct peer *peer)
1412 {
1413 int status;
1414
1415 bgp_peer_conf_if_to_su_update(peer);
1416
1417 if (peer->su.sa.sa_family == AF_UNSPEC) {
1418 if (bgp_debug_neighbor_events(peer))
1419 zlog_debug(
1420 "%s [FSM] Unable to get neighbor's IP address, waiting...",
1421 peer->host);
1422 peer->last_reset = PEER_DOWN_NBR_ADDR;
1423 return -1;
1424 }
1425
1426 if (BGP_PEER_START_SUPPRESSED(peer)) {
1427 if (bgp_debug_neighbor_events(peer))
1428 flog_err(EC_BGP_FSM,
1429 "%s [FSM] Trying to start suppressed peer"
1430 " - this is never supposed to happen!",
1431 peer->host);
1432 return -1;
1433 }
1434
1435 /* Scrub some information that might be left over from a previous,
1436 * session
1437 */
1438 /* Connection information. */
1439 if (peer->su_local) {
1440 sockunion_free(peer->su_local);
1441 peer->su_local = NULL;
1442 }
1443
1444 if (peer->su_remote) {
1445 sockunion_free(peer->su_remote);
1446 peer->su_remote = NULL;
1447 }
1448
1449 /* Clear remote router-id. */
1450 peer->remote_id.s_addr = 0;
1451
1452 /* Clear peer capability flag. */
1453 peer->cap = 0;
1454
1455 /* If the peer is passive mode, force to move to Active mode. */
1456 if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE)) {
1457 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1458 return 0;
1459 }
1460
1461 if (peer->bgp->inst_type != BGP_INSTANCE_TYPE_VIEW &&
1462 peer->bgp->vrf_id == VRF_UNKNOWN) {
1463 if (bgp_debug_neighbor_events(peer))
1464 flog_err(
1465 EC_BGP_FSM,
1466 "%s [FSM] In a VRF that is not initialised yet",
1467 peer->host);
1468 peer->last_reset = PEER_DOWN_VRF_UNINIT;
1469 return -1;
1470 }
1471
1472 /* Register peer for NHT. If next hop is already resolved, proceed
1473 * with connection setup, else wait.
1474 */
1475 if (!bgp_peer_reg_with_nht(peer)) {
1476 if (bgp_zebra_num_connects()) {
1477 if (bgp_debug_neighbor_events(peer))
1478 zlog_debug("%s [FSM] Waiting for NHT",
1479 peer->host);
1480 peer->last_reset = PEER_DOWN_WAITING_NHT;
1481 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1482 return 0;
1483 }
1484 }
1485
1486 assert(!peer->t_write);
1487 assert(!peer->t_read);
1488 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_WRITES_ON));
1489 assert(!CHECK_FLAG(peer->thread_flags, PEER_THREAD_READS_ON));
1490 status = bgp_connect(peer);
1491
1492 switch (status) {
1493 case connect_error:
1494 if (bgp_debug_neighbor_events(peer))
1495 zlog_debug("%s [FSM] Connect error", peer->host);
1496 BGP_EVENT_ADD(peer, TCP_connection_open_failed);
1497 break;
1498 case connect_success:
1499 if (bgp_debug_neighbor_events(peer))
1500 zlog_debug(
1501 "%s [FSM] Connect immediately success, fd %d",
1502 peer->host, peer->fd);
1503 BGP_EVENT_ADD(peer, TCP_connection_open);
1504 break;
1505 case connect_in_progress:
1506 /* To check nonblocking connect, we wait until socket is
1507 readable or writable. */
1508 if (bgp_debug_neighbor_events(peer))
1509 zlog_debug(
1510 "%s [FSM] Non blocking connect waiting result, fd %d",
1511 peer->host, peer->fd);
1512 if (peer->fd < 0) {
1513 flog_err(EC_BGP_FSM,
1514 "bgp_start peer's fd is negative value %d",
1515 peer->fd);
1516 return -1;
1517 }
1518 /*
1519 * - when the socket becomes ready, poll() will signify POLLOUT
1520 * - if it fails to connect, poll() will signify POLLHUP
1521 * - POLLHUP is handled as a 'read' event by thread.c
1522 *
1523 * therefore, we schedule both a read and a write event with
1524 * bgp_connect_check() as the handler for each and cancel the
1525 * unused event in that function.
1526 */
1527 thread_add_read(bm->master, bgp_connect_check, peer, peer->fd,
1528 &peer->t_connect_check_r);
1529 thread_add_write(bm->master, bgp_connect_check, peer, peer->fd,
1530 &peer->t_connect_check_w);
1531 break;
1532 }
1533 return 0;
1534 }
1535
1536 /* Connect retry timer is expired when the peer status is Connect. */
1537 static int bgp_reconnect(struct peer *peer)
1538 {
1539 if (bgp_stop(peer) < 0)
1540 return -1;
1541
1542 bgp_start(peer);
1543 return 0;
1544 }
1545
1546 static int bgp_fsm_open(struct peer *peer)
1547 {
1548 /* Send keepalive and make keepalive timer */
1549 bgp_keepalive_send(peer);
1550
1551 /* Reset holdtimer value. */
1552 BGP_TIMER_OFF(peer->t_holdtime);
1553
1554 return 0;
1555 }
1556
1557 /* FSM error, unexpected event. This is error of BGP connection. So cut the
1558 peer and change to Idle status. */
1559 static int bgp_fsm_event_error(struct peer *peer)
1560 {
1561 flog_err(EC_BGP_FSM, "%s [FSM] unexpected packet received in state %s",
1562 peer->host, lookup_msg(bgp_status_msg, peer->status, NULL));
1563
1564 return bgp_stop_with_notify(peer, BGP_NOTIFY_FSM_ERR, 0);
1565 }
1566
1567 /* Hold timer expire. This is error of BGP connection. So cut the
1568 peer and change to Idle status. */
1569 static int bgp_fsm_holdtime_expire(struct peer *peer)
1570 {
1571 if (bgp_debug_neighbor_events(peer))
1572 zlog_debug("%s [FSM] Hold timer expire", peer->host);
1573
1574 return bgp_stop_with_notify(peer, BGP_NOTIFY_HOLD_ERR, 0);
1575 }
1576
1577 /**
1578 * Transition to Established state.
1579 *
1580 * Convert peer from stub to full fledged peer, set some timers, and generate
1581 * initial updates.
1582 */
1583 static int bgp_establish(struct peer *peer)
1584 {
1585 afi_t afi;
1586 safi_t safi;
1587 int nsf_af_count = 0;
1588 int ret = 0;
1589 struct peer *other;
1590
1591 other = peer->doppelganger;
1592 peer = peer_xfer_conn(peer);
1593 if (!peer) {
1594 flog_err(EC_BGP_CONNECT, "%%Neighbor failed in xfer_conn");
1595 return -1;
1596 }
1597
1598 if (other == peer)
1599 ret = 1; /* bgp_establish specific code when xfer_conn
1600 happens. */
1601
1602 /* Reset capability open status flag. */
1603 if (!CHECK_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN))
1604 SET_FLAG(peer->sflags, PEER_STATUS_CAPABILITY_OPEN);
1605
1606 /* Clear start timer value to default. */
1607 peer->v_start = BGP_INIT_START_TIMER;
1608
1609 /* Increment established count. */
1610 peer->established++;
1611 bgp_fsm_change_status(peer, Established);
1612
1613 /* bgp log-neighbor-changes of neighbor Up */
1614 if (bgp_flag_check(peer->bgp, BGP_FLAG_LOG_NEIGHBOR_CHANGES)) {
1615 struct vrf *vrf = vrf_lookup_by_id(peer->bgp->vrf_id);
1616 zlog_info("%%ADJCHANGE: neighbor %s(%s) in vrf %s Up",
1617 peer->host,
1618 (peer->hostname) ? peer->hostname : "Unknown",
1619 vrf ? ((vrf->vrf_id != VRF_DEFAULT)
1620 ? vrf->name
1621 : VRF_DEFAULT_NAME)
1622 : "");
1623 }
1624 /* assign update-group/subgroup */
1625 update_group_adjust_peer_afs(peer);
1626
1627 /* graceful restart */
1628 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_WAIT);
1629 for (afi = AFI_IP; afi < AFI_MAX; afi++)
1630 for (safi = SAFI_UNICAST; safi <= SAFI_MPLS_VPN; safi++) {
1631 if (peer->afc_nego[afi][safi]
1632 && CHECK_FLAG(peer->cap, PEER_CAP_RESTART_ADV)
1633 && CHECK_FLAG(peer->af_cap[afi][safi],
1634 PEER_CAP_RESTART_AF_RCV)) {
1635 if (peer->nsf[afi][safi]
1636 && !CHECK_FLAG(
1637 peer->af_cap[afi][safi],
1638 PEER_CAP_RESTART_AF_PRESERVE_RCV))
1639 bgp_clear_stale_route(peer, afi, safi);
1640
1641 peer->nsf[afi][safi] = 1;
1642 nsf_af_count++;
1643 } else {
1644 if (peer->nsf[afi][safi])
1645 bgp_clear_stale_route(peer, afi, safi);
1646 peer->nsf[afi][safi] = 0;
1647 }
1648 }
1649
1650 if (nsf_af_count)
1651 SET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1652 else {
1653 UNSET_FLAG(peer->sflags, PEER_STATUS_NSF_MODE);
1654 if (peer->t_gr_stale) {
1655 BGP_TIMER_OFF(peer->t_gr_stale);
1656 if (bgp_debug_neighbor_events(peer))
1657 zlog_debug(
1658 "%s graceful restart stalepath timer stopped",
1659 peer->host);
1660 }
1661 }
1662
1663 if (peer->t_gr_restart) {
1664 BGP_TIMER_OFF(peer->t_gr_restart);
1665 if (bgp_debug_neighbor_events(peer))
1666 zlog_debug("%s graceful restart timer stopped",
1667 peer->host);
1668 }
1669
1670 /* Reset uptime, turn on keepalives, send current table. */
1671 if (!peer->v_holdtime)
1672 bgp_keepalives_on(peer);
1673
1674 peer->uptime = bgp_clock();
1675
1676 /* Send route-refresh when ORF is enabled */
1677 FOREACH_AFI_SAFI (afi, safi) {
1678 if (CHECK_FLAG(peer->af_cap[afi][safi],
1679 PEER_CAP_ORF_PREFIX_SM_ADV)) {
1680 if (CHECK_FLAG(peer->af_cap[afi][safi],
1681 PEER_CAP_ORF_PREFIX_RM_RCV))
1682 bgp_route_refresh_send(peer, afi, safi,
1683 ORF_TYPE_PREFIX,
1684 REFRESH_IMMEDIATE, 0);
1685 else if (CHECK_FLAG(peer->af_cap[afi][safi],
1686 PEER_CAP_ORF_PREFIX_RM_OLD_RCV))
1687 bgp_route_refresh_send(peer, afi, safi,
1688 ORF_TYPE_PREFIX_OLD,
1689 REFRESH_IMMEDIATE, 0);
1690 }
1691 }
1692
1693 /* First update is deferred until ORF or ROUTE-REFRESH is received */
1694 FOREACH_AFI_SAFI (afi, safi) {
1695 if (CHECK_FLAG(peer->af_cap[afi][safi],
1696 PEER_CAP_ORF_PREFIX_RM_ADV))
1697 if (CHECK_FLAG(peer->af_cap[afi][safi],
1698 PEER_CAP_ORF_PREFIX_SM_RCV)
1699 || CHECK_FLAG(peer->af_cap[afi][safi],
1700 PEER_CAP_ORF_PREFIX_SM_OLD_RCV))
1701 SET_FLAG(peer->af_sflags[afi][safi],
1702 PEER_STATUS_ORF_WAIT_REFRESH);
1703 }
1704
1705 bgp_announce_peer(peer);
1706
1707 /* Start the route advertisement timer to send updates to the peer - if
1708 * BGP
1709 * is not in read-only mode. If it is, the timer will be started at the
1710 * end
1711 * of read-only mode.
1712 */
1713 if (!bgp_update_delay_active(peer->bgp)) {
1714 BGP_TIMER_OFF(peer->t_routeadv);
1715 BGP_TIMER_ON(peer->t_routeadv, bgp_routeadv_timer, 0);
1716 }
1717
1718 if (peer->doppelganger && (peer->doppelganger->status != Deleted)) {
1719 if (bgp_debug_neighbor_events(peer))
1720 zlog_debug(
1721 "[Event] Deleting stub connection for peer %s",
1722 peer->host);
1723
1724 if (peer->doppelganger->status > Active)
1725 bgp_notify_send(peer->doppelganger, BGP_NOTIFY_CEASE,
1726 BGP_NOTIFY_CEASE_COLLISION_RESOLUTION);
1727 else
1728 peer_delete(peer->doppelganger);
1729 }
1730
1731 /*
1732 * If we are replacing the old peer for a doppelganger
1733 * then switch it around in the bgp->peerhash
1734 * the doppelgangers su and this peer's su are the same
1735 * so the hash_release is the same for either.
1736 */
1737 hash_release(peer->bgp->peerhash, peer);
1738 hash_get(peer->bgp->peerhash, peer, hash_alloc_intern);
1739
1740 bgp_bfd_register_peer(peer);
1741 return ret;
1742 }
1743
1744 /* Keepalive packet is received. */
1745 static int bgp_fsm_keepalive(struct peer *peer)
1746 {
1747 BGP_TIMER_OFF(peer->t_holdtime);
1748 return 0;
1749 }
1750
1751 /* Update packet is received. */
1752 static int bgp_fsm_update(struct peer *peer)
1753 {
1754 BGP_TIMER_OFF(peer->t_holdtime);
1755 return 0;
1756 }
1757
1758 /* This is empty event. */
1759 static int bgp_ignore(struct peer *peer)
1760 {
1761 flog_err(
1762 EC_BGP_FSM,
1763 "%s [FSM] Ignoring event %s in state %s, prior events %s, %s, fd %d",
1764 peer->host, bgp_event_str[peer->cur_event],
1765 lookup_msg(bgp_status_msg, peer->status, NULL),
1766 bgp_event_str[peer->last_event],
1767 bgp_event_str[peer->last_major_event], peer->fd);
1768 return 0;
1769 }
1770
1771 /* This is to handle unexpected events.. */
1772 static int bgp_fsm_exeption(struct peer *peer)
1773 {
1774 flog_err(
1775 EC_BGP_FSM,
1776 "%s [FSM] Unexpected event %s in state %s, prior events %s, %s, fd %d",
1777 peer->host, bgp_event_str[peer->cur_event],
1778 lookup_msg(bgp_status_msg, peer->status, NULL),
1779 bgp_event_str[peer->last_event],
1780 bgp_event_str[peer->last_major_event], peer->fd);
1781 return (bgp_stop(peer));
1782 }
1783
1784 void bgp_fsm_event_update(struct peer *peer, int valid)
1785 {
1786 if (!peer)
1787 return;
1788
1789 switch (peer->status) {
1790 case Idle:
1791 if (valid)
1792 BGP_EVENT_ADD(peer, BGP_Start);
1793 break;
1794 case Connect:
1795 if (!valid) {
1796 BGP_TIMER_OFF(peer->t_connect);
1797 BGP_EVENT_ADD(peer, TCP_fatal_error);
1798 }
1799 break;
1800 case Active:
1801 if (valid) {
1802 BGP_TIMER_OFF(peer->t_connect);
1803 BGP_EVENT_ADD(peer, ConnectRetry_timer_expired);
1804 }
1805 break;
1806 case OpenSent:
1807 case OpenConfirm:
1808 case Established:
1809 if (!valid && (peer->gtsm_hops == 1))
1810 BGP_EVENT_ADD(peer, TCP_fatal_error);
1811 case Clearing:
1812 case Deleted:
1813 default:
1814 break;
1815 }
1816 }
1817
1818 /* Finite State Machine structure */
1819 static const struct {
1820 int (*func)(struct peer *);
1821 int next_state;
1822 } FSM[BGP_STATUS_MAX - 1][BGP_EVENTS_MAX - 1] = {
1823 {
1824 /* Idle state: In Idle state, all events other than BGP_Start is
1825 ignored. With BGP_Start event, finite state machine calls
1826 bgp_start(). */
1827 {bgp_start, Connect}, /* BGP_Start */
1828 {bgp_stop, Idle}, /* BGP_Stop */
1829 {bgp_stop, Idle}, /* TCP_connection_open */
1830 {bgp_stop, Idle}, /* TCP_connection_closed */
1831 {bgp_ignore, Idle}, /* TCP_connection_open_failed */
1832 {bgp_stop, Idle}, /* TCP_fatal_error */
1833 {bgp_ignore, Idle}, /* ConnectRetry_timer_expired */
1834 {bgp_ignore, Idle}, /* Hold_Timer_expired */
1835 {bgp_ignore, Idle}, /* KeepAlive_timer_expired */
1836 {bgp_ignore, Idle}, /* Receive_OPEN_message */
1837 {bgp_ignore, Idle}, /* Receive_KEEPALIVE_message */
1838 {bgp_ignore, Idle}, /* Receive_UPDATE_message */
1839 {bgp_ignore, Idle}, /* Receive_NOTIFICATION_message */
1840 {bgp_ignore, Idle}, /* Clearing_Completed */
1841 },
1842 {
1843 /* Connect */
1844 {bgp_ignore, Connect}, /* BGP_Start */
1845 {bgp_stop, Idle}, /* BGP_Stop */
1846 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1847 {bgp_stop, Idle}, /* TCP_connection_closed */
1848 {bgp_connect_fail, Active}, /* TCP_connection_open_failed */
1849 {bgp_connect_fail, Idle}, /* TCP_fatal_error */
1850 {bgp_reconnect, Connect}, /* ConnectRetry_timer_expired */
1851 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1852 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1853 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1854 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1855 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1856 {bgp_stop, Idle}, /* Receive_NOTIFICATION_message */
1857 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1858 },
1859 {
1860 /* Active, */
1861 {bgp_ignore, Active}, /* BGP_Start */
1862 {bgp_stop, Idle}, /* BGP_Stop */
1863 {bgp_connect_success, OpenSent}, /* TCP_connection_open */
1864 {bgp_stop, Idle}, /* TCP_connection_closed */
1865 {bgp_ignore, Active}, /* TCP_connection_open_failed */
1866 {bgp_fsm_exeption, Idle}, /* TCP_fatal_error */
1867 {bgp_start, Connect}, /* ConnectRetry_timer_expired */
1868 {bgp_fsm_exeption, Idle}, /* Hold_Timer_expired */
1869 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1870 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1871 {bgp_fsm_exeption, Idle}, /* Receive_KEEPALIVE_message */
1872 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1873 {bgp_fsm_exeption, Idle}, /* Receive_NOTIFICATION_message */
1874 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1875 },
1876 {
1877 /* OpenSent, */
1878 {bgp_ignore, OpenSent}, /* BGP_Start */
1879 {bgp_stop, Idle}, /* BGP_Stop */
1880 {bgp_stop, Active}, /* TCP_connection_open */
1881 {bgp_stop, Active}, /* TCP_connection_closed */
1882 {bgp_stop, Active}, /* TCP_connection_open_failed */
1883 {bgp_stop, Active}, /* TCP_fatal_error */
1884 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1885 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1886 {bgp_fsm_exeption, Idle}, /* KeepAlive_timer_expired */
1887 {bgp_fsm_open, OpenConfirm}, /* Receive_OPEN_message */
1888 {bgp_fsm_event_error, Idle}, /* Receive_KEEPALIVE_message */
1889 {bgp_fsm_event_error, Idle}, /* Receive_UPDATE_message */
1890 {bgp_fsm_event_error, Idle}, /* Receive_NOTIFICATION_message */
1891 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1892 },
1893 {
1894 /* OpenConfirm, */
1895 {bgp_ignore, OpenConfirm}, /* BGP_Start */
1896 {bgp_stop, Idle}, /* BGP_Stop */
1897 {bgp_stop, Idle}, /* TCP_connection_open */
1898 {bgp_stop, Idle}, /* TCP_connection_closed */
1899 {bgp_stop, Idle}, /* TCP_connection_open_failed */
1900 {bgp_stop, Idle}, /* TCP_fatal_error */
1901 {bgp_fsm_exeption, Idle}, /* ConnectRetry_timer_expired */
1902 {bgp_fsm_holdtime_expire, Idle}, /* Hold_Timer_expired */
1903 {bgp_ignore, OpenConfirm}, /* KeepAlive_timer_expired */
1904 {bgp_fsm_exeption, Idle}, /* Receive_OPEN_message */
1905 {bgp_establish, Established}, /* Receive_KEEPALIVE_message */
1906 {bgp_fsm_exeption, Idle}, /* Receive_UPDATE_message */
1907 {bgp_stop_with_error, Idle}, /* Receive_NOTIFICATION_message */
1908 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1909 },
1910 {
1911 /* Established, */
1912 {bgp_ignore, Established}, /* BGP_Start */
1913 {bgp_stop, Clearing}, /* BGP_Stop */
1914 {bgp_stop, Clearing}, /* TCP_connection_open */
1915 {bgp_stop, Clearing}, /* TCP_connection_closed */
1916 {bgp_stop, Clearing}, /* TCP_connection_open_failed */
1917 {bgp_stop, Clearing}, /* TCP_fatal_error */
1918 {bgp_stop, Clearing}, /* ConnectRetry_timer_expired */
1919 {bgp_fsm_holdtime_expire, Clearing}, /* Hold_Timer_expired */
1920 {bgp_ignore, Established}, /* KeepAlive_timer_expired */
1921 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1922 {bgp_fsm_keepalive,
1923 Established}, /* Receive_KEEPALIVE_message */
1924 {bgp_fsm_update, Established}, /* Receive_UPDATE_message */
1925 {bgp_stop_with_error,
1926 Clearing}, /* Receive_NOTIFICATION_message */
1927 {bgp_fsm_exeption, Idle}, /* Clearing_Completed */
1928 },
1929 {
1930 /* Clearing, */
1931 {bgp_ignore, Clearing}, /* BGP_Start */
1932 {bgp_stop, Clearing}, /* BGP_Stop */
1933 {bgp_stop, Clearing}, /* TCP_connection_open */
1934 {bgp_stop, Clearing}, /* TCP_connection_closed */
1935 {bgp_stop, Clearing}, /* TCP_connection_open_failed */
1936 {bgp_stop, Clearing}, /* TCP_fatal_error */
1937 {bgp_stop, Clearing}, /* ConnectRetry_timer_expired */
1938 {bgp_stop, Clearing}, /* Hold_Timer_expired */
1939 {bgp_stop, Clearing}, /* KeepAlive_timer_expired */
1940 {bgp_stop, Clearing}, /* Receive_OPEN_message */
1941 {bgp_stop, Clearing}, /* Receive_KEEPALIVE_message */
1942 {bgp_stop, Clearing}, /* Receive_UPDATE_message */
1943 {bgp_stop, Clearing}, /* Receive_NOTIFICATION_message */
1944 {bgp_clearing_completed, Idle}, /* Clearing_Completed */
1945 },
1946 {
1947 /* Deleted, */
1948 {bgp_ignore, Deleted}, /* BGP_Start */
1949 {bgp_ignore, Deleted}, /* BGP_Stop */
1950 {bgp_ignore, Deleted}, /* TCP_connection_open */
1951 {bgp_ignore, Deleted}, /* TCP_connection_closed */
1952 {bgp_ignore, Deleted}, /* TCP_connection_open_failed */
1953 {bgp_ignore, Deleted}, /* TCP_fatal_error */
1954 {bgp_ignore, Deleted}, /* ConnectRetry_timer_expired */
1955 {bgp_ignore, Deleted}, /* Hold_Timer_expired */
1956 {bgp_ignore, Deleted}, /* KeepAlive_timer_expired */
1957 {bgp_ignore, Deleted}, /* Receive_OPEN_message */
1958 {bgp_ignore, Deleted}, /* Receive_KEEPALIVE_message */
1959 {bgp_ignore, Deleted}, /* Receive_UPDATE_message */
1960 {bgp_ignore, Deleted}, /* Receive_NOTIFICATION_message */
1961 {bgp_ignore, Deleted}, /* Clearing_Completed */
1962 },
1963 };
1964
1965 /* Execute event process. */
1966 int bgp_event(struct thread *thread)
1967 {
1968 int event;
1969 struct peer *peer;
1970 int ret;
1971
1972 peer = THREAD_ARG(thread);
1973 event = THREAD_VAL(thread);
1974
1975 ret = bgp_event_update(peer, event);
1976
1977 return (ret);
1978 }
1979
1980 int bgp_event_update(struct peer *peer, int event)
1981 {
1982 int next;
1983 int ret = 0;
1984 struct peer *other;
1985 int passive_conn = 0;
1986 int dyn_nbr;
1987
1988 /* default return code */
1989 ret = FSM_PEER_NOOP;
1990
1991 other = peer->doppelganger;
1992 passive_conn =
1993 (CHECK_FLAG(peer->sflags, PEER_STATUS_ACCEPT_PEER)) ? 1 : 0;
1994 dyn_nbr = peer_dynamic_neighbor(peer);
1995
1996 /* Logging this event. */
1997 next = FSM[peer->status - 1][event - 1].next_state;
1998
1999 if (bgp_debug_neighbor_events(peer) && peer->status != next)
2000 zlog_debug("%s [FSM] %s (%s->%s), fd %d", peer->host,
2001 bgp_event_str[event],
2002 lookup_msg(bgp_status_msg, peer->status, NULL),
2003 lookup_msg(bgp_status_msg, next, NULL), peer->fd);
2004
2005 peer->last_event = peer->cur_event;
2006 peer->cur_event = event;
2007
2008 /* Call function. */
2009 if (FSM[peer->status - 1][event - 1].func)
2010 ret = (*(FSM[peer->status - 1][event - 1].func))(peer);
2011
2012 if (ret >= 0) {
2013 if (ret == 1 && next == Established) {
2014 /* The case when doppelganger swap accurred in
2015 bgp_establish.
2016 Update the peer pointer accordingly */
2017 ret = FSM_PEER_TRANSFERRED;
2018 peer = other;
2019 }
2020
2021 /* If status is changed. */
2022 if (next != peer->status) {
2023 bgp_fsm_change_status(peer, next);
2024
2025 /*
2026 * If we're going to ESTABLISHED then we executed a
2027 * peer transfer. In this case we can either return
2028 * FSM_PEER_TRANSITIONED or FSM_PEER_TRANSFERRED.
2029 * Opting for TRANSFERRED since transfer implies
2030 * session establishment.
2031 */
2032 if (ret != FSM_PEER_TRANSFERRED)
2033 ret = FSM_PEER_TRANSITIONED;
2034 }
2035
2036 /* Make sure timer is set. */
2037 bgp_timer_set(peer);
2038
2039 } else {
2040 /*
2041 * If we got a return value of -1, that means there was an
2042 * error, restart the FSM. Since bgp_stop() was called on the
2043 * peer. only a few fields are safe to access here. In any case
2044 * we need to indicate that the peer was stopped in the return
2045 * code.
2046 */
2047 if (!dyn_nbr && !passive_conn && peer->bgp) {
2048 flog_err(
2049 EC_BGP_FSM,
2050 "%s [FSM] Failure handling event %s in state %s, "
2051 "prior events %s, %s, fd %d",
2052 peer->host, bgp_event_str[peer->cur_event],
2053 lookup_msg(bgp_status_msg, peer->status, NULL),
2054 bgp_event_str[peer->last_event],
2055 bgp_event_str[peer->last_major_event],
2056 peer->fd);
2057 bgp_stop(peer);
2058 bgp_fsm_change_status(peer, Idle);
2059 bgp_timer_set(peer);
2060 }
2061 ret = FSM_PEER_STOPPED;
2062 }
2063
2064 return ret;
2065 }
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