xref: /openbsd-src/usr.sbin/bgpd/session.c (revision de8cc8edbc71bd3e3bc7fbffa27ba0e564c37d8b)
1 /*	$OpenBSD: session.c,v 1.411 2021/02/16 08:29:16 claudio Exp $ */
2 
3 /*
4  * Copyright (c) 2003, 2004, 2005 Henning Brauer <henning@openbsd.org>
5  * Copyright (c) 2017 Peter van Dijk <peter.van.dijk@powerdns.com>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 
22 #include <sys/mman.h>
23 #include <sys/socket.h>
24 #include <sys/time.h>
25 #include <sys/resource.h>
26 #include <sys/un.h>
27 #include <netinet/in.h>
28 #include <netinet/ip.h>
29 #include <netinet/tcp.h>
30 #include <arpa/inet.h>
31 #include <limits.h>
32 
33 #include <err.h>
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <ifaddrs.h>
37 #include <poll.h>
38 #include <pwd.h>
39 #include <signal.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <syslog.h>
44 #include <unistd.h>
45 
46 #include "bgpd.h"
47 #include "session.h"
48 #include "log.h"
49 
50 #define PFD_PIPE_MAIN		0
51 #define PFD_PIPE_ROUTE		1
52 #define PFD_PIPE_ROUTE_CTL	2
53 #define PFD_SOCK_CTL		3
54 #define PFD_SOCK_RCTL		4
55 #define PFD_LISTENERS_START	5
56 
57 void	session_sighdlr(int);
58 int	setup_listeners(u_int *);
59 void	init_peer(struct peer *);
60 void	start_timer_holdtime(struct peer *);
61 void	start_timer_keepalive(struct peer *);
62 void	session_close_connection(struct peer *);
63 void	change_state(struct peer *, enum session_state, enum session_events);
64 int	session_setup_socket(struct peer *);
65 void	session_accept(int);
66 int	session_connect(struct peer *);
67 void	session_tcp_established(struct peer *);
68 void	session_capa_ann_none(struct peer *);
69 int	session_capa_add(struct ibuf *, u_int8_t, u_int8_t);
70 int	session_capa_add_mp(struct ibuf *, u_int8_t);
71 int	session_capa_add_gr(struct peer *, struct ibuf *, u_int8_t);
72 struct bgp_msg	*session_newmsg(enum msg_type, u_int16_t);
73 int	session_sendmsg(struct bgp_msg *, struct peer *);
74 void	session_open(struct peer *);
75 void	session_keepalive(struct peer *);
76 void	session_update(u_int32_t, void *, size_t);
77 void	session_notification(struct peer *, u_int8_t, u_int8_t, void *,
78 	    ssize_t);
79 void	session_rrefresh(struct peer *, u_int8_t);
80 int	session_graceful_restart(struct peer *);
81 int	session_graceful_stop(struct peer *);
82 int	session_dispatch_msg(struct pollfd *, struct peer *);
83 void	session_process_msg(struct peer *);
84 int	parse_header(struct peer *, u_char *, u_int16_t *, u_int8_t *);
85 int	parse_open(struct peer *);
86 int	parse_update(struct peer *);
87 int	parse_refresh(struct peer *);
88 int	parse_notification(struct peer *);
89 int	parse_capabilities(struct peer *, u_char *, u_int16_t, u_int32_t *);
90 int	capa_neg_calc(struct peer *);
91 void	session_dispatch_imsg(struct imsgbuf *, int, u_int *);
92 void	session_up(struct peer *);
93 void	session_down(struct peer *);
94 int	imsg_rde(int, u_int32_t, void *, u_int16_t);
95 void	session_demote(struct peer *, int);
96 void	merge_peers(struct bgpd_config *, struct bgpd_config *);
97 
98 int		 la_cmp(struct listen_addr *, struct listen_addr *);
99 void		 session_template_clone(struct peer *, struct sockaddr *,
100 		    u_int32_t, u_int32_t);
101 int		 session_match_mask(struct peer *, struct bgpd_addr *);
102 
103 static struct bgpd_config	*conf, *nconf;
104 static struct imsgbuf		*ibuf_rde;
105 static struct imsgbuf		*ibuf_rde_ctl;
106 static struct imsgbuf		*ibuf_main;
107 
108 struct bgpd_sysdep	 sysdep;
109 volatile sig_atomic_t	 session_quit;
110 int			 pending_reconf;
111 int			 csock = -1, rcsock = -1;
112 u_int			 peer_cnt;
113 
114 struct mrt_head		 mrthead;
115 time_t			 pauseaccept;
116 
117 static inline int
118 peer_compare(const struct peer *a, const struct peer *b)
119 {
120 	return a->conf.id - b->conf.id;
121 }
122 
123 RB_GENERATE(peer_head, peer, entry, peer_compare);
124 
125 void
126 session_sighdlr(int sig)
127 {
128 	switch (sig) {
129 	case SIGINT:
130 	case SIGTERM:
131 		session_quit = 1;
132 		break;
133 	}
134 }
135 
136 int
137 setup_listeners(u_int *la_cnt)
138 {
139 	int			 ttl = 255;
140 	struct listen_addr	*la;
141 	u_int			 cnt = 0;
142 
143 	TAILQ_FOREACH(la, conf->listen_addrs, entry) {
144 		la->reconf = RECONF_NONE;
145 		cnt++;
146 
147 		if (la->flags & LISTENER_LISTENING)
148 			continue;
149 
150 		if (la->fd == -1) {
151 			log_warn("cannot establish listener on %s: invalid fd",
152 			    log_sockaddr((struct sockaddr *)&la->sa,
153 			    la->sa_len));
154 			continue;
155 		}
156 
157 		if (tcp_md5_prep_listener(la, &conf->peers) == -1)
158 			fatal("tcp_md5_prep_listener");
159 
160 		/* set ttl to 255 so that ttl-security works */
161 		if (la->sa.ss_family == AF_INET && setsockopt(la->fd,
162 		    IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) == -1) {
163 			log_warn("setup_listeners setsockopt TTL");
164 			continue;
165 		}
166 		if (la->sa.ss_family == AF_INET6 && setsockopt(la->fd,
167 		    IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) == -1) {
168 			log_warn("setup_listeners setsockopt hoplimit");
169 			continue;
170 		}
171 
172 		if (listen(la->fd, MAX_BACKLOG)) {
173 			close(la->fd);
174 			fatal("listen");
175 		}
176 
177 		la->flags |= LISTENER_LISTENING;
178 
179 		log_info("listening on %s",
180 		    log_sockaddr((struct sockaddr *)&la->sa, la->sa_len));
181 	}
182 
183 	*la_cnt = cnt;
184 
185 	return (0);
186 }
187 
188 void
189 session_main(int debug, int verbose)
190 {
191 	int			 timeout;
192 	unsigned int		 i, j, idx_peers, idx_listeners, idx_mrts;
193 	u_int			 pfd_elms = 0, peer_l_elms = 0, mrt_l_elms = 0;
194 	u_int			 listener_cnt, ctl_cnt, mrt_cnt;
195 	u_int			 new_cnt;
196 	struct passwd		*pw;
197 	struct peer		*p, **peer_l = NULL, *next;
198 	struct mrt		*m, *xm, **mrt_l = NULL;
199 	struct pollfd		*pfd = NULL;
200 	struct listen_addr	*la;
201 	void			*newp;
202 	time_t			 now;
203 	short			 events;
204 
205 	log_init(debug, LOG_DAEMON);
206 	log_setverbose(verbose);
207 
208 	log_procinit(log_procnames[PROC_SE]);
209 
210 	if ((pw = getpwnam(BGPD_USER)) == NULL)
211 		fatal(NULL);
212 
213 	if (chroot(pw->pw_dir) == -1)
214 		fatal("chroot");
215 	if (chdir("/") == -1)
216 		fatal("chdir(\"/\")");
217 
218 	setproctitle("session engine");
219 
220 	if (setgroups(1, &pw->pw_gid) ||
221 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
222 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
223 		fatal("can't drop privileges");
224 
225 	if (pledge("stdio inet recvfd", NULL) == -1)
226 		fatal("pledge");
227 
228 	signal(SIGTERM, session_sighdlr);
229 	signal(SIGINT, session_sighdlr);
230 	signal(SIGPIPE, SIG_IGN);
231 	signal(SIGHUP, SIG_IGN);
232 	signal(SIGALRM, SIG_IGN);
233 	signal(SIGUSR1, SIG_IGN);
234 
235 	if ((ibuf_main = malloc(sizeof(struct imsgbuf))) == NULL)
236 		fatal(NULL);
237 	imsg_init(ibuf_main, 3);
238 
239 	LIST_INIT(&mrthead);
240 	listener_cnt = 0;
241 	peer_cnt = 0;
242 	ctl_cnt = 0;
243 
244 	conf = new_config();
245 	log_info("session engine ready");
246 
247 	while (session_quit == 0) {
248 		/* check for peers to be initialized or deleted */
249 		if (!pending_reconf) {
250 			RB_FOREACH_SAFE(p, peer_head, &conf->peers, next) {
251 				/* cloned peer that idled out? */
252 				if (p->template && (p->state == STATE_IDLE ||
253 				    p->state == STATE_ACTIVE) &&
254 				    getmonotime() - p->stats.last_updown >=
255 				    INTERVAL_HOLD_CLONED)
256 					p->reconf_action = RECONF_DELETE;
257 
258 				/* new peer that needs init? */
259 				if (p->state == STATE_NONE)
260 					init_peer(p);
261 
262 				/* reinit due? */
263 				if (p->reconf_action == RECONF_REINIT) {
264 					session_stop(p, ERR_CEASE_ADMIN_RESET);
265 					if (!p->conf.down)
266 						timer_set(&p->timers,
267 						    Timer_IdleHold, 0);
268 				}
269 
270 				/* deletion due? */
271 				if (p->reconf_action == RECONF_DELETE) {
272 					if (p->demoted)
273 						session_demote(p, -1);
274 					p->conf.demote_group[0] = 0;
275 					session_stop(p, ERR_CEASE_PEER_UNCONF);
276 					timer_remove_all(&p->timers);
277 					tcp_md5_del_listener(conf, p);
278 					log_peer_warnx(&p->conf, "removed");
279 					RB_REMOVE(peer_head, &conf->peers, p);
280 					free(p);
281 					peer_cnt--;
282 					continue;
283 				}
284 				p->reconf_action = RECONF_NONE;
285 			}
286 		}
287 
288 		if (peer_cnt > peer_l_elms) {
289 			if ((newp = reallocarray(peer_l, peer_cnt,
290 			    sizeof(struct peer *))) == NULL) {
291 				/* panic for now  */
292 				log_warn("could not resize peer_l from %u -> %u"
293 				    " entries", peer_l_elms, peer_cnt);
294 				fatalx("exiting");
295 			}
296 			peer_l = newp;
297 			peer_l_elms = peer_cnt;
298 		}
299 
300 		mrt_cnt = 0;
301 		for (m = LIST_FIRST(&mrthead); m != NULL; m = xm) {
302 			xm = LIST_NEXT(m, entry);
303 			if (m->state == MRT_STATE_REMOVE) {
304 				mrt_clean(m);
305 				LIST_REMOVE(m, entry);
306 				free(m);
307 				continue;
308 			}
309 			if (m->wbuf.queued)
310 				mrt_cnt++;
311 		}
312 
313 		if (mrt_cnt > mrt_l_elms) {
314 			if ((newp = reallocarray(mrt_l, mrt_cnt,
315 			    sizeof(struct mrt *))) == NULL) {
316 				/* panic for now  */
317 				log_warn("could not resize mrt_l from %u -> %u"
318 				    " entries", mrt_l_elms, mrt_cnt);
319 				fatalx("exiting");
320 			}
321 			mrt_l = newp;
322 			mrt_l_elms = mrt_cnt;
323 		}
324 
325 		new_cnt = PFD_LISTENERS_START + listener_cnt + peer_cnt +
326 		    ctl_cnt + mrt_cnt;
327 		if (new_cnt > pfd_elms) {
328 			if ((newp = reallocarray(pfd, new_cnt,
329 			    sizeof(struct pollfd))) == NULL) {
330 				/* panic for now  */
331 				log_warn("could not resize pfd from %u -> %u"
332 				    " entries", pfd_elms, new_cnt);
333 				fatalx("exiting");
334 			}
335 			pfd = newp;
336 			pfd_elms = new_cnt;
337 		}
338 
339 		bzero(pfd, sizeof(struct pollfd) * pfd_elms);
340 
341 		set_pollfd(&pfd[PFD_PIPE_MAIN], ibuf_main);
342 		set_pollfd(&pfd[PFD_PIPE_ROUTE], ibuf_rde);
343 		set_pollfd(&pfd[PFD_PIPE_ROUTE_CTL], ibuf_rde_ctl);
344 
345 		if (pauseaccept == 0) {
346 			pfd[PFD_SOCK_CTL].fd = csock;
347 			pfd[PFD_SOCK_CTL].events = POLLIN;
348 			pfd[PFD_SOCK_RCTL].fd = rcsock;
349 			pfd[PFD_SOCK_RCTL].events = POLLIN;
350 		} else {
351 			pfd[PFD_SOCK_CTL].fd = -1;
352 			pfd[PFD_SOCK_RCTL].fd = -1;
353 		}
354 
355 		i = PFD_LISTENERS_START;
356 		TAILQ_FOREACH(la, conf->listen_addrs, entry) {
357 			if (pauseaccept == 0) {
358 				pfd[i].fd = la->fd;
359 				pfd[i].events = POLLIN;
360 			} else
361 				pfd[i].fd = -1;
362 			i++;
363 		}
364 		idx_listeners = i;
365 		timeout = 240;	/* loop every 240s at least */
366 
367 		now = getmonotime();
368 		RB_FOREACH(p, peer_head, &conf->peers) {
369 			time_t	nextaction;
370 			struct timer *pt;
371 
372 			/* check timers */
373 			if ((pt = timer_nextisdue(&p->timers, now)) != NULL) {
374 				switch (pt->type) {
375 				case Timer_Hold:
376 					bgp_fsm(p, EVNT_TIMER_HOLDTIME);
377 					break;
378 				case Timer_SendHold:
379 					bgp_fsm(p, EVNT_TIMER_SENDHOLD);
380 					break;
381 				case Timer_ConnectRetry:
382 					bgp_fsm(p, EVNT_TIMER_CONNRETRY);
383 					break;
384 				case Timer_Keepalive:
385 					bgp_fsm(p, EVNT_TIMER_KEEPALIVE);
386 					break;
387 				case Timer_IdleHold:
388 					bgp_fsm(p, EVNT_START);
389 					break;
390 				case Timer_IdleHoldReset:
391 					p->IdleHoldTime =
392 					    INTERVAL_IDLE_HOLD_INITIAL;
393 					p->errcnt = 0;
394 					timer_stop(&p->timers,
395 					    Timer_IdleHoldReset);
396 					break;
397 				case Timer_CarpUndemote:
398 					timer_stop(&p->timers,
399 					    Timer_CarpUndemote);
400 					if (p->demoted &&
401 					    p->state == STATE_ESTABLISHED)
402 						session_demote(p, -1);
403 					break;
404 				case Timer_RestartTimeout:
405 					timer_stop(&p->timers,
406 					    Timer_RestartTimeout);
407 					session_graceful_stop(p);
408 					break;
409 				default:
410 					fatalx("King Bula lost in time");
411 				}
412 			}
413 			if ((nextaction = timer_nextduein(&p->timers,
414 			    now)) != -1 && nextaction < timeout)
415 				timeout = nextaction;
416 
417 			/* are we waiting for a write? */
418 			events = POLLIN;
419 			if (p->wbuf.queued > 0 || p->state == STATE_CONNECT)
420 				events |= POLLOUT;
421 			/* is there still work to do? */
422 			if (p->rpending && p->rbuf && p->rbuf->wpos)
423 				timeout = 0;
424 
425 			/* poll events */
426 			if (p->fd != -1 && events != 0) {
427 				pfd[i].fd = p->fd;
428 				pfd[i].events = events;
429 				peer_l[i - idx_listeners] = p;
430 				i++;
431 			}
432 		}
433 
434 		idx_peers = i;
435 
436 		LIST_FOREACH(m, &mrthead, entry)
437 			if (m->wbuf.queued) {
438 				pfd[i].fd = m->wbuf.fd;
439 				pfd[i].events = POLLOUT;
440 				mrt_l[i - idx_peers] = m;
441 				i++;
442 			}
443 
444 		idx_mrts = i;
445 
446 		i += control_fill_pfds(pfd + i, pfd_elms -i);
447 
448 		if (i > pfd_elms)
449 			fatalx("poll pfd overflow");
450 
451 		if (pauseaccept && timeout > 1)
452 			timeout = 1;
453 		if (timeout < 0)
454 			timeout = 0;
455 		if (poll(pfd, i, timeout * 1000) == -1)
456 			if (errno != EINTR)
457 				fatal("poll error");
458 
459 		/*
460 		 * If we previously saw fd exhaustion, we stop accept()
461 		 * for 1 second to throttle the accept() loop.
462 		 */
463 		if (pauseaccept && getmonotime() > pauseaccept + 1)
464 			pauseaccept = 0;
465 
466 		if (handle_pollfd(&pfd[PFD_PIPE_MAIN], ibuf_main) == -1) {
467 			log_warnx("SE: Lost connection to parent");
468 			session_quit = 1;
469 			continue;
470 		} else
471 			session_dispatch_imsg(ibuf_main, PFD_PIPE_MAIN,
472 			    &listener_cnt);
473 
474 		if (handle_pollfd(&pfd[PFD_PIPE_ROUTE], ibuf_rde) == -1) {
475 			log_warnx("SE: Lost connection to RDE");
476 			msgbuf_clear(&ibuf_rde->w);
477 			free(ibuf_rde);
478 			ibuf_rde = NULL;
479 		} else
480 			session_dispatch_imsg(ibuf_rde, PFD_PIPE_ROUTE,
481 			    &listener_cnt);
482 
483 		if (handle_pollfd(&pfd[PFD_PIPE_ROUTE_CTL], ibuf_rde_ctl) ==
484 		    -1) {
485 			log_warnx("SE: Lost connection to RDE control");
486 			msgbuf_clear(&ibuf_rde_ctl->w);
487 			free(ibuf_rde_ctl);
488 			ibuf_rde_ctl = NULL;
489 		} else
490 			session_dispatch_imsg(ibuf_rde_ctl, PFD_PIPE_ROUTE_CTL,
491 			    &listener_cnt);
492 
493 		if (pfd[PFD_SOCK_CTL].revents & POLLIN)
494 			ctl_cnt += control_accept(csock, 0);
495 
496 		if (pfd[PFD_SOCK_RCTL].revents & POLLIN)
497 			ctl_cnt += control_accept(rcsock, 1);
498 
499 		for (j = PFD_LISTENERS_START; j < idx_listeners; j++)
500 			if (pfd[j].revents & POLLIN)
501 				session_accept(pfd[j].fd);
502 
503 		for (; j < idx_peers; j++)
504 			session_dispatch_msg(&pfd[j],
505 			    peer_l[j - idx_listeners]);
506 
507 		RB_FOREACH(p, peer_head, &conf->peers)
508 			if (p->rbuf && p->rbuf->wpos)
509 				session_process_msg(p);
510 
511 		for (; j < idx_mrts; j++)
512 			if (pfd[j].revents & POLLOUT)
513 				mrt_write(mrt_l[j - idx_peers]);
514 
515 		for (; j < i; j++)
516 			ctl_cnt -= control_dispatch_msg(&pfd[j], &conf->peers);
517 	}
518 
519 	RB_FOREACH_SAFE(p, peer_head, &conf->peers, next) {
520 		RB_REMOVE(peer_head, &conf->peers, p);
521 		strlcpy(p->conf.reason,
522 		    "bgpd shutting down",
523 		    sizeof(p->conf.reason));
524 		session_stop(p, ERR_CEASE_ADMIN_DOWN);
525 		timer_remove_all(&p->timers);
526 		free(p);
527 	}
528 
529 	while ((m = LIST_FIRST(&mrthead)) != NULL) {
530 		mrt_clean(m);
531 		LIST_REMOVE(m, entry);
532 		free(m);
533 	}
534 
535 	free_config(conf);
536 	free(peer_l);
537 	free(mrt_l);
538 	free(pfd);
539 
540 	/* close pipes */
541 	if (ibuf_rde) {
542 		msgbuf_write(&ibuf_rde->w);
543 		msgbuf_clear(&ibuf_rde->w);
544 		close(ibuf_rde->fd);
545 		free(ibuf_rde);
546 	}
547 	if (ibuf_rde_ctl) {
548 		msgbuf_clear(&ibuf_rde_ctl->w);
549 		close(ibuf_rde_ctl->fd);
550 		free(ibuf_rde_ctl);
551 	}
552 	msgbuf_write(&ibuf_main->w);
553 	msgbuf_clear(&ibuf_main->w);
554 	close(ibuf_main->fd);
555 	free(ibuf_main);
556 
557 	control_shutdown(csock);
558 	control_shutdown(rcsock);
559 	log_info("session engine exiting");
560 	exit(0);
561 }
562 
563 void
564 init_peer(struct peer *p)
565 {
566 	TAILQ_INIT(&p->timers);
567 	p->fd = p->wbuf.fd = -1;
568 
569 	if (p->conf.if_depend[0])
570 		imsg_compose(ibuf_main, IMSG_IFINFO, 0, 0, -1,
571 		    p->conf.if_depend, sizeof(p->conf.if_depend));
572 	else
573 		p->depend_ok = 1;
574 
575 	peer_cnt++;
576 
577 	change_state(p, STATE_IDLE, EVNT_NONE);
578 	if (p->conf.down)
579 		timer_stop(&p->timers, Timer_IdleHold); /* no autostart */
580 	else
581 		timer_set(&p->timers, Timer_IdleHold, 0); /* start ASAP */
582 
583 	/*
584 	 * on startup, demote if requested.
585 	 * do not handle new peers. they must reach ESTABLISHED beforehands.
586 	 * peers added at runtime have reconf_action set to RECONF_REINIT.
587 	 */
588 	if (p->reconf_action != RECONF_REINIT && p->conf.demote_group[0])
589 		session_demote(p, +1);
590 }
591 
592 void
593 bgp_fsm(struct peer *peer, enum session_events event)
594 {
595 	switch (peer->state) {
596 	case STATE_NONE:
597 		/* nothing */
598 		break;
599 	case STATE_IDLE:
600 		switch (event) {
601 		case EVNT_START:
602 			timer_stop(&peer->timers, Timer_Hold);
603 			timer_stop(&peer->timers, Timer_SendHold);
604 			timer_stop(&peer->timers, Timer_Keepalive);
605 			timer_stop(&peer->timers, Timer_IdleHold);
606 
607 			/* allocate read buffer */
608 			peer->rbuf = calloc(1, sizeof(struct ibuf_read));
609 			if (peer->rbuf == NULL)
610 				fatal(NULL);
611 
612 			/* init write buffer */
613 			msgbuf_init(&peer->wbuf);
614 
615 			peer->stats.last_sent_errcode = 0;
616 			peer->stats.last_sent_suberr = 0;
617 			peer->stats.last_rcvd_errcode = 0;
618 			peer->stats.last_rcvd_suberr = 0;
619 
620 			if (!peer->depend_ok)
621 				timer_stop(&peer->timers, Timer_ConnectRetry);
622 			else if (peer->passive || peer->conf.passive ||
623 			    peer->conf.template) {
624 				change_state(peer, STATE_ACTIVE, event);
625 				timer_stop(&peer->timers, Timer_ConnectRetry);
626 			} else {
627 				change_state(peer, STATE_CONNECT, event);
628 				timer_set(&peer->timers, Timer_ConnectRetry,
629 				    conf->connectretry);
630 				session_connect(peer);
631 			}
632 			peer->passive = 0;
633 			break;
634 		default:
635 			/* ignore */
636 			break;
637 		}
638 		break;
639 	case STATE_CONNECT:
640 		switch (event) {
641 		case EVNT_START:
642 			/* ignore */
643 			break;
644 		case EVNT_CON_OPEN:
645 			session_tcp_established(peer);
646 			session_open(peer);
647 			timer_stop(&peer->timers, Timer_ConnectRetry);
648 			peer->holdtime = INTERVAL_HOLD_INITIAL;
649 			start_timer_holdtime(peer);
650 			change_state(peer, STATE_OPENSENT, event);
651 			break;
652 		case EVNT_CON_OPENFAIL:
653 			timer_set(&peer->timers, Timer_ConnectRetry,
654 			    conf->connectretry);
655 			session_close_connection(peer);
656 			change_state(peer, STATE_ACTIVE, event);
657 			break;
658 		case EVNT_TIMER_CONNRETRY:
659 			timer_set(&peer->timers, Timer_ConnectRetry,
660 			    conf->connectretry);
661 			session_connect(peer);
662 			break;
663 		default:
664 			change_state(peer, STATE_IDLE, event);
665 			break;
666 		}
667 		break;
668 	case STATE_ACTIVE:
669 		switch (event) {
670 		case EVNT_START:
671 			/* ignore */
672 			break;
673 		case EVNT_CON_OPEN:
674 			session_tcp_established(peer);
675 			session_open(peer);
676 			timer_stop(&peer->timers, Timer_ConnectRetry);
677 			peer->holdtime = INTERVAL_HOLD_INITIAL;
678 			start_timer_holdtime(peer);
679 			change_state(peer, STATE_OPENSENT, event);
680 			break;
681 		case EVNT_CON_OPENFAIL:
682 			timer_set(&peer->timers, Timer_ConnectRetry,
683 			    conf->connectretry);
684 			session_close_connection(peer);
685 			change_state(peer, STATE_ACTIVE, event);
686 			break;
687 		case EVNT_TIMER_CONNRETRY:
688 			timer_set(&peer->timers, Timer_ConnectRetry,
689 			    peer->holdtime);
690 			change_state(peer, STATE_CONNECT, event);
691 			session_connect(peer);
692 			break;
693 		default:
694 			change_state(peer, STATE_IDLE, event);
695 			break;
696 		}
697 		break;
698 	case STATE_OPENSENT:
699 		switch (event) {
700 		case EVNT_START:
701 			/* ignore */
702 			break;
703 		case EVNT_STOP:
704 			change_state(peer, STATE_IDLE, event);
705 			break;
706 		case EVNT_CON_CLOSED:
707 			session_close_connection(peer);
708 			timer_set(&peer->timers, Timer_ConnectRetry,
709 			    conf->connectretry);
710 			change_state(peer, STATE_ACTIVE, event);
711 			break;
712 		case EVNT_CON_FATAL:
713 			change_state(peer, STATE_IDLE, event);
714 			break;
715 		case EVNT_TIMER_HOLDTIME:
716 		case EVNT_TIMER_SENDHOLD:
717 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
718 			    0, NULL, 0);
719 			change_state(peer, STATE_IDLE, event);
720 			break;
721 		case EVNT_RCVD_OPEN:
722 			/* parse_open calls change_state itself on failure */
723 			if (parse_open(peer))
724 				break;
725 			session_keepalive(peer);
726 			change_state(peer, STATE_OPENCONFIRM, event);
727 			break;
728 		case EVNT_RCVD_NOTIFICATION:
729 			if (parse_notification(peer)) {
730 				change_state(peer, STATE_IDLE, event);
731 				/* don't punish, capa negotiation */
732 				timer_set(&peer->timers, Timer_IdleHold, 0);
733 				peer->IdleHoldTime /= 2;
734 			} else
735 				change_state(peer, STATE_IDLE, event);
736 			break;
737 		default:
738 			session_notification(peer,
739 			    ERR_FSM, ERR_FSM_UNEX_OPENSENT, NULL, 0);
740 			change_state(peer, STATE_IDLE, event);
741 			break;
742 		}
743 		break;
744 	case STATE_OPENCONFIRM:
745 		switch (event) {
746 		case EVNT_START:
747 			/* ignore */
748 			break;
749 		case EVNT_STOP:
750 			change_state(peer, STATE_IDLE, event);
751 			break;
752 		case EVNT_CON_CLOSED:
753 		case EVNT_CON_FATAL:
754 			change_state(peer, STATE_IDLE, event);
755 			break;
756 		case EVNT_TIMER_HOLDTIME:
757 		case EVNT_TIMER_SENDHOLD:
758 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
759 			    0, NULL, 0);
760 			change_state(peer, STATE_IDLE, event);
761 			break;
762 		case EVNT_TIMER_KEEPALIVE:
763 			session_keepalive(peer);
764 			break;
765 		case EVNT_RCVD_KEEPALIVE:
766 			start_timer_holdtime(peer);
767 			change_state(peer, STATE_ESTABLISHED, event);
768 			break;
769 		case EVNT_RCVD_NOTIFICATION:
770 			parse_notification(peer);
771 			change_state(peer, STATE_IDLE, event);
772 			break;
773 		default:
774 			session_notification(peer,
775 			    ERR_FSM, ERR_FSM_UNEX_OPENCONFIRM, NULL, 0);
776 			change_state(peer, STATE_IDLE, event);
777 			break;
778 		}
779 		break;
780 	case STATE_ESTABLISHED:
781 		switch (event) {
782 		case EVNT_START:
783 			/* ignore */
784 			break;
785 		case EVNT_STOP:
786 			change_state(peer, STATE_IDLE, event);
787 			break;
788 		case EVNT_CON_CLOSED:
789 		case EVNT_CON_FATAL:
790 			change_state(peer, STATE_IDLE, event);
791 			break;
792 		case EVNT_TIMER_HOLDTIME:
793 		case EVNT_TIMER_SENDHOLD:
794 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
795 			    0, NULL, 0);
796 			change_state(peer, STATE_IDLE, event);
797 			break;
798 		case EVNT_TIMER_KEEPALIVE:
799 			session_keepalive(peer);
800 			break;
801 		case EVNT_RCVD_KEEPALIVE:
802 			start_timer_holdtime(peer);
803 			break;
804 		case EVNT_RCVD_UPDATE:
805 			start_timer_holdtime(peer);
806 			if (parse_update(peer))
807 				change_state(peer, STATE_IDLE, event);
808 			else
809 				start_timer_holdtime(peer);
810 			break;
811 		case EVNT_RCVD_NOTIFICATION:
812 			parse_notification(peer);
813 			change_state(peer, STATE_IDLE, event);
814 			break;
815 		default:
816 			session_notification(peer,
817 			    ERR_FSM, ERR_FSM_UNEX_ESTABLISHED, NULL, 0);
818 			change_state(peer, STATE_IDLE, event);
819 			break;
820 		}
821 		break;
822 	}
823 }
824 
825 void
826 start_timer_holdtime(struct peer *peer)
827 {
828 	if (peer->holdtime > 0)
829 		timer_set(&peer->timers, Timer_Hold, peer->holdtime);
830 	else
831 		timer_stop(&peer->timers, Timer_Hold);
832 }
833 
834 void
835 start_timer_keepalive(struct peer *peer)
836 {
837 	if (peer->holdtime > 0)
838 		timer_set(&peer->timers, Timer_Keepalive, peer->holdtime / 3);
839 	else
840 		timer_stop(&peer->timers, Timer_Keepalive);
841 }
842 
843 void
844 session_close_connection(struct peer *peer)
845 {
846 	if (peer->fd != -1) {
847 		close(peer->fd);
848 		pauseaccept = 0;
849 	}
850 	peer->fd = peer->wbuf.fd = -1;
851 }
852 
853 void
854 change_state(struct peer *peer, enum session_state state,
855     enum session_events event)
856 {
857 	struct mrt	*mrt;
858 
859 	switch (state) {
860 	case STATE_IDLE:
861 		/* carp demotion first. new peers handled in init_peer */
862 		if (peer->state == STATE_ESTABLISHED &&
863 		    peer->conf.demote_group[0] && !peer->demoted)
864 			session_demote(peer, +1);
865 
866 		/*
867 		 * try to write out what's buffered (maybe a notification),
868 		 * don't bother if it fails
869 		 */
870 		if (peer->state >= STATE_OPENSENT && peer->wbuf.queued)
871 			msgbuf_write(&peer->wbuf);
872 
873 		/*
874 		 * we must start the timer for the next EVNT_START
875 		 * if we are coming here due to an error and the
876 		 * session was not established successfully before, the
877 		 * starttimerinterval needs to be exponentially increased
878 		 */
879 		if (peer->IdleHoldTime == 0)
880 			peer->IdleHoldTime = INTERVAL_IDLE_HOLD_INITIAL;
881 		peer->holdtime = INTERVAL_HOLD_INITIAL;
882 		timer_stop(&peer->timers, Timer_ConnectRetry);
883 		timer_stop(&peer->timers, Timer_Keepalive);
884 		timer_stop(&peer->timers, Timer_Hold);
885 		timer_stop(&peer->timers, Timer_SendHold);
886 		timer_stop(&peer->timers, Timer_IdleHold);
887 		timer_stop(&peer->timers, Timer_IdleHoldReset);
888 		session_close_connection(peer);
889 		msgbuf_clear(&peer->wbuf);
890 		free(peer->rbuf);
891 		peer->rbuf = NULL;
892 		peer->rpending = 0;
893 		bzero(&peer->capa.peer, sizeof(peer->capa.peer));
894 		if (!peer->template)
895 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
896 			    peer->conf.id, 0, -1, NULL, 0);
897 
898 		if (event != EVNT_STOP) {
899 			timer_set(&peer->timers, Timer_IdleHold,
900 			    peer->IdleHoldTime);
901 			if (event != EVNT_NONE &&
902 			    peer->IdleHoldTime < MAX_IDLE_HOLD/2)
903 				peer->IdleHoldTime *= 2;
904 		}
905 		if (peer->state == STATE_ESTABLISHED) {
906 			if (peer->capa.neg.grestart.restart == 2 &&
907 			    (event == EVNT_CON_CLOSED ||
908 			    event == EVNT_CON_FATAL)) {
909 				/* don't punish graceful restart */
910 				timer_set(&peer->timers, Timer_IdleHold, 0);
911 				peer->IdleHoldTime /= 2;
912 				session_graceful_restart(peer);
913 			} else
914 				session_down(peer);
915 		}
916 		if (peer->state == STATE_NONE ||
917 		    peer->state == STATE_ESTABLISHED) {
918 			/* initialize capability negotiation structures */
919 			memcpy(&peer->capa.ann, &peer->conf.capabilities,
920 			    sizeof(peer->capa.ann));
921 			if (!peer->conf.announce_capa)
922 				session_capa_ann_none(peer);
923 		}
924 		break;
925 	case STATE_CONNECT:
926 		if (peer->state == STATE_ESTABLISHED &&
927 		    peer->capa.neg.grestart.restart == 2) {
928 			/* do the graceful restart dance */
929 			session_graceful_restart(peer);
930 			peer->holdtime = INTERVAL_HOLD_INITIAL;
931 			timer_stop(&peer->timers, Timer_ConnectRetry);
932 			timer_stop(&peer->timers, Timer_Keepalive);
933 			timer_stop(&peer->timers, Timer_Hold);
934 			timer_stop(&peer->timers, Timer_SendHold);
935 			timer_stop(&peer->timers, Timer_IdleHold);
936 			timer_stop(&peer->timers, Timer_IdleHoldReset);
937 			session_close_connection(peer);
938 			msgbuf_clear(&peer->wbuf);
939 			bzero(&peer->capa.peer, sizeof(peer->capa.peer));
940 		}
941 		break;
942 	case STATE_ACTIVE:
943 		if (!peer->template)
944 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
945 			    peer->conf.id, 0, -1, NULL, 0);
946 		break;
947 	case STATE_OPENSENT:
948 		break;
949 	case STATE_OPENCONFIRM:
950 		break;
951 	case STATE_ESTABLISHED:
952 		timer_set(&peer->timers, Timer_IdleHoldReset,
953 		    peer->IdleHoldTime);
954 		if (peer->demoted)
955 			timer_set(&peer->timers, Timer_CarpUndemote,
956 			    INTERVAL_HOLD_DEMOTED);
957 		session_up(peer);
958 		break;
959 	default:		/* something seriously fucked */
960 		break;
961 	}
962 
963 	log_statechange(peer, state, event);
964 	LIST_FOREACH(mrt, &mrthead, entry) {
965 		if (!(mrt->type == MRT_ALL_IN || mrt->type == MRT_ALL_OUT))
966 			continue;
967 		if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
968 		    mrt->peer_id == peer->conf.id || (mrt->group_id != 0 &&
969 		    mrt->group_id == peer->conf.groupid))
970 			mrt_dump_state(mrt, peer->state, state, peer);
971 	}
972 	peer->prev_state = peer->state;
973 	peer->state = state;
974 }
975 
976 void
977 session_accept(int listenfd)
978 {
979 	int			 connfd;
980 	socklen_t		 len;
981 	struct sockaddr_storage	 cliaddr;
982 	struct peer		*p = NULL;
983 
984 	len = sizeof(cliaddr);
985 	if ((connfd = accept4(listenfd,
986 	    (struct sockaddr *)&cliaddr, &len,
987 	    SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
988 		if (errno == ENFILE || errno == EMFILE)
989 			pauseaccept = getmonotime();
990 		else if (errno != EWOULDBLOCK && errno != EINTR &&
991 		    errno != ECONNABORTED)
992 			log_warn("accept");
993 		return;
994 	}
995 
996 	p = getpeerbyip(conf, (struct sockaddr *)&cliaddr);
997 
998 	if (p != NULL && p->state == STATE_IDLE && p->errcnt < 2) {
999 		if (timer_running(&p->timers, Timer_IdleHold, NULL)) {
1000 			/* fast reconnect after clear */
1001 			p->passive = 1;
1002 			bgp_fsm(p, EVNT_START);
1003 		}
1004 	}
1005 
1006 	if (p != NULL &&
1007 	    (p->state == STATE_CONNECT || p->state == STATE_ACTIVE)) {
1008 		if (p->fd != -1) {
1009 			if (p->state == STATE_CONNECT)
1010 				session_close_connection(p);
1011 			else {
1012 				close(connfd);
1013 				return;
1014 			}
1015 		}
1016 
1017 open:
1018 		if (p->conf.auth.method != AUTH_NONE && sysdep.no_pfkey) {
1019 			log_peer_warnx(&p->conf,
1020 			    "ipsec or md5sig configured but not available");
1021 			close(connfd);
1022 			return;
1023 		}
1024 
1025 		if (tcp_md5_check(connfd, p) == -1) {
1026 			close(connfd);
1027 			return;
1028 		}
1029 		p->fd = p->wbuf.fd = connfd;
1030 		if (session_setup_socket(p)) {
1031 			close(connfd);
1032 			return;
1033 		}
1034 		bgp_fsm(p, EVNT_CON_OPEN);
1035 		return;
1036 	} else if (p != NULL && p->state == STATE_ESTABLISHED &&
1037 	    p->capa.neg.grestart.restart == 2) {
1038 		/* first do the graceful restart dance */
1039 		change_state(p, STATE_CONNECT, EVNT_CON_CLOSED);
1040 		/* then do part of the open dance */
1041 		goto open;
1042 	} else {
1043 		log_conn_attempt(p, (struct sockaddr *)&cliaddr, len);
1044 		close(connfd);
1045 	}
1046 }
1047 
1048 int
1049 session_connect(struct peer *peer)
1050 {
1051 	struct sockaddr		*sa;
1052 	struct bgpd_addr	*bind_addr = NULL;
1053 	socklen_t		 sa_len;
1054 
1055 	/*
1056 	 * we do not need the overcomplicated collision detection RFC 1771
1057 	 * describes; we simply make sure there is only ever one concurrent
1058 	 * tcp connection per peer.
1059 	 */
1060 	if (peer->fd != -1)
1061 		return (-1);
1062 
1063 	if ((peer->fd = socket(aid2af(peer->conf.remote_addr.aid),
1064 	    SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_TCP)) == -1) {
1065 		log_peer_warn(&peer->conf, "session_connect socket");
1066 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1067 		return (-1);
1068 	}
1069 
1070 	if (peer->conf.auth.method != AUTH_NONE && sysdep.no_pfkey) {
1071 		log_peer_warnx(&peer->conf,
1072 		    "ipsec or md5sig configured but not available");
1073 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1074 		return (-1);
1075 	}
1076 
1077 	tcp_md5_set(peer->fd, peer);
1078 	peer->wbuf.fd = peer->fd;
1079 
1080 	/* if local-address is set we need to bind() */
1081 	switch (peer->conf.remote_addr.aid) {
1082 	case AID_INET:
1083 		bind_addr = &peer->conf.local_addr_v4;
1084 		break;
1085 	case AID_INET6:
1086 		bind_addr = &peer->conf.local_addr_v6;
1087 		break;
1088 	}
1089 	if ((sa = addr2sa(bind_addr, 0, &sa_len)) != NULL) {
1090 		if (bind(peer->fd, sa, sa_len) == -1) {
1091 			log_peer_warn(&peer->conf, "session_connect bind");
1092 			bgp_fsm(peer, EVNT_CON_OPENFAIL);
1093 			return (-1);
1094 		}
1095 	}
1096 
1097 	if (session_setup_socket(peer)) {
1098 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1099 		return (-1);
1100 	}
1101 
1102 	sa = addr2sa(&peer->conf.remote_addr, BGP_PORT, &sa_len);
1103 	if (connect(peer->fd, sa, sa_len) == -1) {
1104 		if (errno != EINPROGRESS) {
1105 			if (errno != peer->lasterr)
1106 				log_peer_warn(&peer->conf, "connect");
1107 			peer->lasterr = errno;
1108 			bgp_fsm(peer, EVNT_CON_OPENFAIL);
1109 			return (-1);
1110 		}
1111 	} else
1112 		bgp_fsm(peer, EVNT_CON_OPEN);
1113 
1114 	return (0);
1115 }
1116 
1117 int
1118 session_setup_socket(struct peer *p)
1119 {
1120 	int	ttl = p->conf.distance;
1121 	int	pre = IPTOS_PREC_INTERNETCONTROL;
1122 	int	nodelay = 1;
1123 	int	bsize;
1124 
1125 	switch (p->conf.remote_addr.aid) {
1126 	case AID_INET:
1127 		/* set precedence, see RFC 1771 appendix 5 */
1128 		if (setsockopt(p->fd, IPPROTO_IP, IP_TOS, &pre, sizeof(pre)) ==
1129 		    -1) {
1130 			log_peer_warn(&p->conf,
1131 			    "session_setup_socket setsockopt TOS");
1132 			return (-1);
1133 		}
1134 
1135 		if (p->conf.ebgp) {
1136 			/*
1137 			 * set TTL to foreign router's distance
1138 			 * 1=direct n=multihop with ttlsec, we always use 255
1139 			 */
1140 			if (p->conf.ttlsec) {
1141 				ttl = 256 - p->conf.distance;
1142 				if (setsockopt(p->fd, IPPROTO_IP, IP_MINTTL,
1143 				    &ttl, sizeof(ttl)) == -1) {
1144 					log_peer_warn(&p->conf,
1145 					    "session_setup_socket: "
1146 					    "setsockopt MINTTL");
1147 					return (-1);
1148 				}
1149 				ttl = 255;
1150 			}
1151 
1152 			if (setsockopt(p->fd, IPPROTO_IP, IP_TTL, &ttl,
1153 			    sizeof(ttl)) == -1) {
1154 				log_peer_warn(&p->conf,
1155 				    "session_setup_socket setsockopt TTL");
1156 				return (-1);
1157 			}
1158 		}
1159 		break;
1160 	case AID_INET6:
1161 		if (p->conf.ebgp) {
1162 			/*
1163 			 * set hoplimit to foreign router's distance
1164 			 * 1=direct n=multihop with ttlsec, we always use 255
1165 			 */
1166 			if (p->conf.ttlsec) {
1167 				ttl = 256 - p->conf.distance;
1168 				if (setsockopt(p->fd, IPPROTO_IPV6,
1169 				    IPV6_MINHOPCOUNT, &ttl, sizeof(ttl))
1170 				    == -1) {
1171 					log_peer_warn(&p->conf,
1172 					    "session_setup_socket: "
1173 					    "setsockopt MINHOPCOUNT");
1174 					return (-1);
1175 				}
1176 				ttl = 255;
1177 			}
1178 			if (setsockopt(p->fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
1179 			    &ttl, sizeof(ttl)) == -1) {
1180 				log_peer_warn(&p->conf,
1181 				    "session_setup_socket setsockopt hoplimit");
1182 				return (-1);
1183 			}
1184 		}
1185 		break;
1186 	}
1187 
1188 	/* set TCP_NODELAY */
1189 	if (setsockopt(p->fd, IPPROTO_TCP, TCP_NODELAY, &nodelay,
1190 	    sizeof(nodelay)) == -1) {
1191 		log_peer_warn(&p->conf,
1192 		    "session_setup_socket setsockopt TCP_NODELAY");
1193 		return (-1);
1194 	}
1195 
1196 	/* only increase bufsize (and thus window) if md5 or ipsec is in use */
1197 	if (p->conf.auth.method != AUTH_NONE) {
1198 		/* try to increase bufsize. no biggie if it fails */
1199 		bsize = 65535;
1200 		while (bsize > 8192 &&
1201 		    setsockopt(p->fd, SOL_SOCKET, SO_RCVBUF, &bsize,
1202 		    sizeof(bsize)) == -1 && errno != EINVAL)
1203 			bsize /= 2;
1204 		bsize = 65535;
1205 		while (bsize > 8192 &&
1206 		    setsockopt(p->fd, SOL_SOCKET, SO_SNDBUF, &bsize,
1207 		    sizeof(bsize)) == -1 && errno != EINVAL)
1208 			bsize /= 2;
1209 	}
1210 
1211 	return (0);
1212 }
1213 
1214 /* compare two sockaddrs by converting them into bgpd_addr */
1215 static int
1216 sa_cmp(struct sockaddr *a, struct sockaddr *b)
1217 {
1218 	struct bgpd_addr ba, bb;
1219 
1220 	sa2addr(a, &ba, NULL);
1221 	sa2addr(b, &bb, NULL);
1222 
1223 	return (memcmp(&ba, &bb, sizeof(ba)) == 0);
1224 }
1225 
1226 static void
1227 get_alternate_addr(struct sockaddr *sa, struct bgpd_addr *alt)
1228 {
1229 	struct ifaddrs	*ifap, *ifa, *match;
1230 
1231 	if (getifaddrs(&ifap) == -1)
1232 		fatal("getifaddrs");
1233 
1234 	for (match = ifap; match != NULL; match = match->ifa_next)
1235 		if (match->ifa_addr != NULL &&
1236 		    sa_cmp(sa, match->ifa_addr) == 0)
1237 			break;
1238 
1239 	if (match == NULL) {
1240 		log_warnx("%s: local address not found", __func__);
1241 		return;
1242 	}
1243 
1244 	switch (sa->sa_family) {
1245 	case AF_INET6:
1246 		for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
1247 			if (ifa->ifa_addr != NULL &&
1248 			    ifa->ifa_addr->sa_family == AF_INET &&
1249 			    strcmp(ifa->ifa_name, match->ifa_name) == 0) {
1250 				sa2addr(ifa->ifa_addr, alt, NULL);
1251 				break;
1252 			}
1253 		}
1254 		break;
1255 	case AF_INET:
1256 		for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
1257 			if (ifa->ifa_addr != NULL &&
1258 			    ifa->ifa_addr->sa_family == AF_INET6 &&
1259 			    strcmp(ifa->ifa_name, match->ifa_name) == 0) {
1260 				struct sockaddr_in6 *s =
1261 				    (struct sockaddr_in6 *)ifa->ifa_addr;
1262 
1263 				/* only accept global scope addresses */
1264 				if (IN6_IS_ADDR_LINKLOCAL(&s->sin6_addr) ||
1265 				    IN6_IS_ADDR_SITELOCAL(&s->sin6_addr))
1266 					continue;
1267 				sa2addr(ifa->ifa_addr, alt, NULL);
1268 				break;
1269 			}
1270 		}
1271 		break;
1272 	default:
1273 		log_warnx("%s: unsupported address family %d", __func__,
1274 		    sa->sa_family);
1275 		break;
1276 	}
1277 
1278 	freeifaddrs(ifap);
1279 }
1280 
1281 void
1282 session_tcp_established(struct peer *peer)
1283 {
1284 	struct sockaddr_storage	ss;
1285 	socklen_t		len;
1286 
1287 	len = sizeof(ss);
1288 	if (getsockname(peer->fd, (struct sockaddr *)&ss, &len) == -1)
1289 		log_warn("getsockname");
1290 	sa2addr((struct sockaddr *)&ss, &peer->local, &peer->local_port);
1291 	get_alternate_addr((struct sockaddr *)&ss, &peer->local_alt);
1292 	len = sizeof(ss);
1293 	if (getpeername(peer->fd, (struct sockaddr *)&ss, &len) == -1)
1294 		log_warn("getpeername");
1295 	sa2addr((struct sockaddr *)&ss, &peer->remote, &peer->remote_port);
1296 }
1297 
1298 void
1299 session_capa_ann_none(struct peer *peer)
1300 {
1301 	bzero(&peer->capa.ann, sizeof(peer->capa.ann));
1302 }
1303 
1304 int
1305 session_capa_add(struct ibuf *opb, u_int8_t capa_code, u_int8_t capa_len)
1306 {
1307 	int errs = 0;
1308 
1309 	errs += ibuf_add(opb, &capa_code, sizeof(capa_code));
1310 	errs += ibuf_add(opb, &capa_len, sizeof(capa_len));
1311 	return (errs);
1312 }
1313 
1314 int
1315 session_capa_add_mp(struct ibuf *buf, u_int8_t aid)
1316 {
1317 	u_int8_t		 safi, pad = 0;
1318 	u_int16_t		 afi;
1319 	int			 errs = 0;
1320 
1321 	if (aid2afi(aid, &afi, &safi) == -1)
1322 		fatalx("session_capa_add_mp: bad afi/safi pair");
1323 	afi = htons(afi);
1324 	errs += ibuf_add(buf, &afi, sizeof(afi));
1325 	errs += ibuf_add(buf, &pad, sizeof(pad));
1326 	errs += ibuf_add(buf, &safi, sizeof(safi));
1327 
1328 	return (errs);
1329 }
1330 
1331 int
1332 session_capa_add_gr(struct peer *p, struct ibuf *b, u_int8_t aid)
1333 {
1334 	u_int		errs = 0;
1335 	u_int16_t	afi;
1336 	u_int8_t	flags, safi;
1337 
1338 	if (aid2afi(aid, &afi, &safi)) {
1339 		log_warn("session_capa_add_gr: bad AID");
1340 		return (1);
1341 	}
1342 	if (p->capa.neg.grestart.flags[aid] & CAPA_GR_RESTARTING)
1343 		flags = CAPA_GR_F_FLAG;
1344 	else
1345 		flags = 0;
1346 
1347 	afi = htons(afi);
1348 	errs += ibuf_add(b, &afi, sizeof(afi));
1349 	errs += ibuf_add(b, &safi, sizeof(safi));
1350 	errs += ibuf_add(b, &flags, sizeof(flags));
1351 
1352 	return (errs);
1353 }
1354 
1355 struct bgp_msg *
1356 session_newmsg(enum msg_type msgtype, u_int16_t len)
1357 {
1358 	struct bgp_msg		*msg;
1359 	struct msg_header	 hdr;
1360 	struct ibuf		*buf;
1361 	int			 errs = 0;
1362 
1363 	memset(&hdr.marker, 0xff, sizeof(hdr.marker));
1364 	hdr.len = htons(len);
1365 	hdr.type = msgtype;
1366 
1367 	if ((buf = ibuf_open(len)) == NULL)
1368 		return (NULL);
1369 
1370 	errs += ibuf_add(buf, &hdr.marker, sizeof(hdr.marker));
1371 	errs += ibuf_add(buf, &hdr.len, sizeof(hdr.len));
1372 	errs += ibuf_add(buf, &hdr.type, sizeof(hdr.type));
1373 
1374 	if (errs || (msg = calloc(1, sizeof(*msg))) == NULL) {
1375 		ibuf_free(buf);
1376 		return (NULL);
1377 	}
1378 
1379 	msg->buf = buf;
1380 	msg->type = msgtype;
1381 	msg->len = len;
1382 
1383 	return (msg);
1384 }
1385 
1386 int
1387 session_sendmsg(struct bgp_msg *msg, struct peer *p)
1388 {
1389 	struct mrt		*mrt;
1390 
1391 	LIST_FOREACH(mrt, &mrthead, entry) {
1392 		if (!(mrt->type == MRT_ALL_OUT || (msg->type == UPDATE &&
1393 		    mrt->type == MRT_UPDATE_OUT)))
1394 			continue;
1395 		if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
1396 		    mrt->peer_id == p->conf.id || (mrt->group_id != 0 &&
1397 		    mrt->group_id == p->conf.groupid))
1398 			mrt_dump_bgp_msg(mrt, msg->buf->buf, msg->len, p);
1399 	}
1400 
1401 	ibuf_close(&p->wbuf, msg->buf);
1402 	if (!p->throttled && p->wbuf.queued > SESS_MSG_HIGH_MARK) {
1403 		if (imsg_rde(IMSG_XOFF, p->conf.id, NULL, 0) == -1)
1404 			log_peer_warn(&p->conf, "imsg_compose XOFF");
1405 		else
1406 			p->throttled = 1;
1407 	}
1408 
1409 	free(msg);
1410 	return (0);
1411 }
1412 
1413 void
1414 session_open(struct peer *p)
1415 {
1416 	struct bgp_msg		*buf;
1417 	struct ibuf		*opb;
1418 	struct msg_open		 msg;
1419 	u_int16_t		 len;
1420 	u_int8_t		 i, op_type, optparamlen = 0;
1421 	int			 errs = 0;
1422 	int			 mpcapa = 0;
1423 
1424 
1425 	if ((opb = ibuf_dynamic(0, UCHAR_MAX - sizeof(op_type) -
1426 	    sizeof(optparamlen))) == NULL) {
1427 		bgp_fsm(p, EVNT_CON_FATAL);
1428 		return;
1429 	}
1430 
1431 	/* multiprotocol extensions, RFC 4760 */
1432 	for (i = 0; i < AID_MAX; i++)
1433 		if (p->capa.ann.mp[i]) {	/* 4 bytes data */
1434 			errs += session_capa_add(opb, CAPA_MP, 4);
1435 			errs += session_capa_add_mp(opb, i);
1436 			mpcapa++;
1437 		}
1438 
1439 	/* route refresh, RFC 2918 */
1440 	if (p->capa.ann.refresh)	/* no data */
1441 		errs += session_capa_add(opb, CAPA_REFRESH, 0);
1442 
1443 	/* graceful restart and End-of-RIB marker, RFC 4724 */
1444 	if (p->capa.ann.grestart.restart) {
1445 		int		rst = 0;
1446 		u_int16_t	hdr;
1447 		u_int8_t	grlen;
1448 
1449 		if (mpcapa) {
1450 			grlen = 2 + 4 * mpcapa;
1451 			for (i = 0; i < AID_MAX; i++) {
1452 				if (p->capa.neg.grestart.flags[i] &
1453 				    CAPA_GR_RESTARTING)
1454 					rst++;
1455 			}
1456 		} else {	/* AID_INET */
1457 			grlen = 2 + 4;
1458 			if (p->capa.neg.grestart.flags[AID_INET] &
1459 			    CAPA_GR_RESTARTING)
1460 				rst++;
1461 		}
1462 
1463 		hdr = conf->holdtime;		/* default timeout */
1464 		/* if client does graceful restart don't set R flag */
1465 		if (!rst)
1466 			hdr |= CAPA_GR_R_FLAG;
1467 		hdr = htons(hdr);
1468 
1469 		errs += session_capa_add(opb, CAPA_RESTART, grlen);
1470 		errs += ibuf_add(opb, &hdr, sizeof(hdr));
1471 
1472 		if (mpcapa) {
1473 			for (i = 0; i < AID_MAX; i++) {
1474 				if (p->capa.ann.mp[i]) {
1475 					errs += session_capa_add_gr(p, opb, i);
1476 				}
1477 			}
1478 		} else {	/* AID_INET */
1479 			errs += session_capa_add_gr(p, opb, AID_INET);
1480 		}
1481 	}
1482 
1483 	/* 4-bytes AS numbers, draft-ietf-idr-as4bytes-13 */
1484 	if (p->capa.ann.as4byte) {	/* 4 bytes data */
1485 		u_int32_t	nas;
1486 
1487 		nas = htonl(p->conf.local_as);
1488 		errs += session_capa_add(opb, CAPA_AS4BYTE, sizeof(nas));
1489 		errs += ibuf_add(opb, &nas, sizeof(nas));
1490 	}
1491 
1492 	if (ibuf_size(opb))
1493 		optparamlen = ibuf_size(opb) + sizeof(op_type) +
1494 		    sizeof(optparamlen);
1495 
1496 	len = MSGSIZE_OPEN_MIN + optparamlen;
1497 	if (errs || (buf = session_newmsg(OPEN, len)) == NULL) {
1498 		ibuf_free(opb);
1499 		bgp_fsm(p, EVNT_CON_FATAL);
1500 		return;
1501 	}
1502 
1503 	msg.version = 4;
1504 	msg.myas = htons(p->conf.local_short_as);
1505 	if (p->conf.holdtime)
1506 		msg.holdtime = htons(p->conf.holdtime);
1507 	else
1508 		msg.holdtime = htons(conf->holdtime);
1509 	msg.bgpid = conf->bgpid;	/* is already in network byte order */
1510 	msg.optparamlen = optparamlen;
1511 
1512 	errs += ibuf_add(buf->buf, &msg.version, sizeof(msg.version));
1513 	errs += ibuf_add(buf->buf, &msg.myas, sizeof(msg.myas));
1514 	errs += ibuf_add(buf->buf, &msg.holdtime, sizeof(msg.holdtime));
1515 	errs += ibuf_add(buf->buf, &msg.bgpid, sizeof(msg.bgpid));
1516 	errs += ibuf_add(buf->buf, &msg.optparamlen, sizeof(msg.optparamlen));
1517 
1518 	if (optparamlen) {
1519 		op_type = OPT_PARAM_CAPABILITIES;
1520 		optparamlen = ibuf_size(opb);
1521 		errs += ibuf_add(buf->buf, &op_type, sizeof(op_type));
1522 		errs += ibuf_add(buf->buf, &optparamlen, sizeof(optparamlen));
1523 		errs += ibuf_add(buf->buf, opb->buf, ibuf_size(opb));
1524 	}
1525 
1526 	ibuf_free(opb);
1527 
1528 	if (errs) {
1529 		ibuf_free(buf->buf);
1530 		free(buf);
1531 		bgp_fsm(p, EVNT_CON_FATAL);
1532 		return;
1533 	}
1534 
1535 	if (session_sendmsg(buf, p) == -1) {
1536 		bgp_fsm(p, EVNT_CON_FATAL);
1537 		return;
1538 	}
1539 
1540 	p->stats.msg_sent_open++;
1541 }
1542 
1543 void
1544 session_keepalive(struct peer *p)
1545 {
1546 	struct bgp_msg		*buf;
1547 
1548 	if ((buf = session_newmsg(KEEPALIVE, MSGSIZE_KEEPALIVE)) == NULL ||
1549 	    session_sendmsg(buf, p) == -1) {
1550 		bgp_fsm(p, EVNT_CON_FATAL);
1551 		return;
1552 	}
1553 
1554 	start_timer_keepalive(p);
1555 	p->stats.msg_sent_keepalive++;
1556 }
1557 
1558 void
1559 session_update(u_int32_t peerid, void *data, size_t datalen)
1560 {
1561 	struct peer		*p;
1562 	struct bgp_msg		*buf;
1563 
1564 	if ((p = getpeerbyid(conf, peerid)) == NULL) {
1565 		log_warnx("no such peer: id=%u", peerid);
1566 		return;
1567 	}
1568 
1569 	if (p->state != STATE_ESTABLISHED)
1570 		return;
1571 
1572 	if ((buf = session_newmsg(UPDATE, MSGSIZE_HEADER + datalen)) == NULL) {
1573 		bgp_fsm(p, EVNT_CON_FATAL);
1574 		return;
1575 	}
1576 
1577 	if (ibuf_add(buf->buf, data, datalen)) {
1578 		ibuf_free(buf->buf);
1579 		free(buf);
1580 		bgp_fsm(p, EVNT_CON_FATAL);
1581 		return;
1582 	}
1583 
1584 	if (session_sendmsg(buf, p) == -1) {
1585 		bgp_fsm(p, EVNT_CON_FATAL);
1586 		return;
1587 	}
1588 
1589 	start_timer_keepalive(p);
1590 	p->stats.msg_sent_update++;
1591 }
1592 
1593 void
1594 session_notification(struct peer *p, u_int8_t errcode, u_int8_t subcode,
1595     void *data, ssize_t datalen)
1596 {
1597 	struct bgp_msg		*buf;
1598 	int			 errs = 0;
1599 
1600 	if (p->stats.last_sent_errcode)	/* some notification already sent */
1601 		return;
1602 
1603 	log_notification(p, errcode, subcode, data, datalen, "sending");
1604 
1605 	if ((buf = session_newmsg(NOTIFICATION,
1606 	    MSGSIZE_NOTIFICATION_MIN + datalen)) == NULL) {
1607 		bgp_fsm(p, EVNT_CON_FATAL);
1608 		return;
1609 	}
1610 
1611 	errs += ibuf_add(buf->buf, &errcode, sizeof(errcode));
1612 	errs += ibuf_add(buf->buf, &subcode, sizeof(subcode));
1613 
1614 	if (datalen > 0)
1615 		errs += ibuf_add(buf->buf, data, datalen);
1616 
1617 	if (errs) {
1618 		ibuf_free(buf->buf);
1619 		free(buf);
1620 		bgp_fsm(p, EVNT_CON_FATAL);
1621 		return;
1622 	}
1623 
1624 	if (session_sendmsg(buf, p) == -1) {
1625 		bgp_fsm(p, EVNT_CON_FATAL);
1626 		return;
1627 	}
1628 
1629 	p->stats.msg_sent_notification++;
1630 	p->stats.last_sent_errcode = errcode;
1631 	p->stats.last_sent_suberr = subcode;
1632 }
1633 
1634 int
1635 session_neighbor_rrefresh(struct peer *p)
1636 {
1637 	u_int8_t	i;
1638 
1639 	if (!p->capa.peer.refresh)
1640 		return (-1);
1641 
1642 	for (i = 0; i < AID_MAX; i++) {
1643 		if (p->capa.peer.mp[i] != 0)
1644 			session_rrefresh(p, i);
1645 	}
1646 
1647 	return (0);
1648 }
1649 
1650 void
1651 session_rrefresh(struct peer *p, u_int8_t aid)
1652 {
1653 	struct bgp_msg		*buf;
1654 	int			 errs = 0;
1655 	u_int16_t		 afi;
1656 	u_int8_t		 safi, null8 = 0;
1657 
1658 	if (aid2afi(aid, &afi, &safi) == -1)
1659 		fatalx("session_rrefresh: bad afi/safi pair");
1660 
1661 	if ((buf = session_newmsg(RREFRESH, MSGSIZE_RREFRESH)) == NULL) {
1662 		bgp_fsm(p, EVNT_CON_FATAL);
1663 		return;
1664 	}
1665 
1666 	afi = htons(afi);
1667 	errs += ibuf_add(buf->buf, &afi, sizeof(afi));
1668 	errs += ibuf_add(buf->buf, &null8, sizeof(null8));
1669 	errs += ibuf_add(buf->buf, &safi, sizeof(safi));
1670 
1671 	if (errs) {
1672 		ibuf_free(buf->buf);
1673 		free(buf);
1674 		bgp_fsm(p, EVNT_CON_FATAL);
1675 		return;
1676 	}
1677 
1678 	if (session_sendmsg(buf, p) == -1) {
1679 		bgp_fsm(p, EVNT_CON_FATAL);
1680 		return;
1681 	}
1682 
1683 	p->stats.msg_sent_rrefresh++;
1684 }
1685 
1686 int
1687 session_graceful_restart(struct peer *p)
1688 {
1689 	u_int8_t	i;
1690 
1691 	timer_set(&p->timers, Timer_RestartTimeout,
1692 	    p->capa.neg.grestart.timeout);
1693 
1694 	for (i = 0; i < AID_MAX; i++) {
1695 		if (p->capa.neg.grestart.flags[i] & CAPA_GR_PRESENT) {
1696 			if (imsg_rde(IMSG_SESSION_STALE, p->conf.id,
1697 			    &i, sizeof(i)) == -1)
1698 				return (-1);
1699 			log_peer_warnx(&p->conf,
1700 			    "graceful restart of %s, keeping routes",
1701 			    aid2str(i));
1702 			p->capa.neg.grestart.flags[i] |= CAPA_GR_RESTARTING;
1703 		} else if (p->capa.neg.mp[i]) {
1704 			if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
1705 			    &i, sizeof(i)) == -1)
1706 				return (-1);
1707 			log_peer_warnx(&p->conf,
1708 			    "graceful restart of %s, flushing routes",
1709 			    aid2str(i));
1710 		}
1711 	}
1712 	return (0);
1713 }
1714 
1715 int
1716 session_graceful_stop(struct peer *p)
1717 {
1718 	u_int8_t	i;
1719 
1720 	for (i = 0; i < AID_MAX; i++) {
1721 		/*
1722 		 * Only flush if the peer is restarting and the timeout fired.
1723 		 * In all other cases the session was already flushed when the
1724 		 * session went down or when the new open message was parsed.
1725 		 */
1726 		if (p->capa.neg.grestart.flags[i] & CAPA_GR_RESTARTING) {
1727 			log_peer_warnx(&p->conf, "graceful restart of %s, "
1728 			    "time-out, flushing", aid2str(i));
1729 			if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
1730 			    &i, sizeof(i)) == -1)
1731 				return (-1);
1732 		}
1733 		p->capa.neg.grestart.flags[i] &= ~CAPA_GR_RESTARTING;
1734 	}
1735 	return (0);
1736 }
1737 
1738 int
1739 session_dispatch_msg(struct pollfd *pfd, struct peer *p)
1740 {
1741 	ssize_t		n;
1742 	socklen_t	len;
1743 	int		error;
1744 
1745 	if (p->state == STATE_CONNECT) {
1746 		if (pfd->revents & POLLOUT) {
1747 			if (pfd->revents & POLLIN) {
1748 				/* error occurred */
1749 				len = sizeof(error);
1750 				if (getsockopt(pfd->fd, SOL_SOCKET, SO_ERROR,
1751 				    &error, &len) == -1 || error) {
1752 					if (error)
1753 						errno = error;
1754 					if (errno != p->lasterr) {
1755 						log_peer_warn(&p->conf,
1756 						    "socket error");
1757 						p->lasterr = errno;
1758 					}
1759 					bgp_fsm(p, EVNT_CON_OPENFAIL);
1760 					return (1);
1761 				}
1762 			}
1763 			bgp_fsm(p, EVNT_CON_OPEN);
1764 			return (1);
1765 		}
1766 		if (pfd->revents & POLLHUP) {
1767 			bgp_fsm(p, EVNT_CON_OPENFAIL);
1768 			return (1);
1769 		}
1770 		if (pfd->revents & (POLLERR|POLLNVAL)) {
1771 			bgp_fsm(p, EVNT_CON_FATAL);
1772 			return (1);
1773 		}
1774 		return (0);
1775 	}
1776 
1777 	if (pfd->revents & POLLHUP) {
1778 		bgp_fsm(p, EVNT_CON_CLOSED);
1779 		return (1);
1780 	}
1781 	if (pfd->revents & (POLLERR|POLLNVAL)) {
1782 		bgp_fsm(p, EVNT_CON_FATAL);
1783 		return (1);
1784 	}
1785 
1786 	if (pfd->revents & POLLOUT && p->wbuf.queued) {
1787 		if ((error = msgbuf_write(&p->wbuf)) <= 0 && errno != EAGAIN) {
1788 			if (error == 0)
1789 				log_peer_warnx(&p->conf, "Connection closed");
1790 			else if (error == -1)
1791 				log_peer_warn(&p->conf, "write error");
1792 			bgp_fsm(p, EVNT_CON_FATAL);
1793 			return (1);
1794 		}
1795 		p->stats.last_write = getmonotime();
1796 		if (p->holdtime > 0)
1797 			timer_set(&p->timers, Timer_SendHold,
1798 			    p->holdtime < INTERVAL_HOLD ? INTERVAL_HOLD :
1799 			    p->holdtime);
1800 		if (p->throttled && p->wbuf.queued < SESS_MSG_LOW_MARK) {
1801 			if (imsg_rde(IMSG_XON, p->conf.id, NULL, 0) == -1)
1802 				log_peer_warn(&p->conf, "imsg_compose XON");
1803 			else
1804 				p->throttled = 0;
1805 		}
1806 		if (!(pfd->revents & POLLIN))
1807 			return (1);
1808 	}
1809 
1810 	if (p->rbuf && pfd->revents & POLLIN) {
1811 		if ((n = read(p->fd, p->rbuf->buf + p->rbuf->wpos,
1812 		    sizeof(p->rbuf->buf) - p->rbuf->wpos)) == -1) {
1813 			if (errno != EINTR && errno != EAGAIN) {
1814 				log_peer_warn(&p->conf, "read error");
1815 				bgp_fsm(p, EVNT_CON_FATAL);
1816 			}
1817 			return (1);
1818 		}
1819 		if (n == 0) {	/* connection closed */
1820 			bgp_fsm(p, EVNT_CON_CLOSED);
1821 			return (1);
1822 		}
1823 
1824 		p->rbuf->wpos += n;
1825 		p->stats.last_read = getmonotime();
1826 		return (1);
1827 	}
1828 	return (0);
1829 }
1830 
1831 void
1832 session_process_msg(struct peer *p)
1833 {
1834 	struct mrt	*mrt;
1835 	ssize_t		rpos, av, left;
1836 	int		processed = 0;
1837 	u_int16_t	msglen;
1838 	u_int8_t	msgtype;
1839 
1840 	rpos = 0;
1841 	av = p->rbuf->wpos;
1842 	p->rpending = 0;
1843 
1844 	/*
1845 	 * session might drop to IDLE -> buffers deallocated
1846 	 * we MUST check rbuf != NULL before use
1847 	 */
1848 	for (;;) {
1849 		if (p->rbuf == NULL)
1850 			return;
1851 		if (rpos + MSGSIZE_HEADER > av)
1852 			break;
1853 		if (parse_header(p, p->rbuf->buf + rpos, &msglen,
1854 		    &msgtype) == -1)
1855 			return;
1856 		if (rpos + msglen > av)
1857 			break;
1858 		p->rbuf->rptr = p->rbuf->buf + rpos;
1859 
1860 		/* dump to MRT as soon as we have a full packet */
1861 		LIST_FOREACH(mrt, &mrthead, entry) {
1862 			if (!(mrt->type == MRT_ALL_IN || (msgtype == UPDATE &&
1863 			    mrt->type == MRT_UPDATE_IN)))
1864 				continue;
1865 			if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
1866 			    mrt->peer_id == p->conf.id || (mrt->group_id != 0 &&
1867 			    mrt->group_id == p->conf.groupid))
1868 				mrt_dump_bgp_msg(mrt, p->rbuf->rptr, msglen, p);
1869 		}
1870 
1871 		switch (msgtype) {
1872 		case OPEN:
1873 			bgp_fsm(p, EVNT_RCVD_OPEN);
1874 			p->stats.msg_rcvd_open++;
1875 			break;
1876 		case UPDATE:
1877 			bgp_fsm(p, EVNT_RCVD_UPDATE);
1878 			p->stats.msg_rcvd_update++;
1879 			break;
1880 		case NOTIFICATION:
1881 			bgp_fsm(p, EVNT_RCVD_NOTIFICATION);
1882 			p->stats.msg_rcvd_notification++;
1883 			break;
1884 		case KEEPALIVE:
1885 			bgp_fsm(p, EVNT_RCVD_KEEPALIVE);
1886 			p->stats.msg_rcvd_keepalive++;
1887 			break;
1888 		case RREFRESH:
1889 			parse_refresh(p);
1890 			p->stats.msg_rcvd_rrefresh++;
1891 			break;
1892 		default:	/* cannot happen */
1893 			session_notification(p, ERR_HEADER, ERR_HDR_TYPE,
1894 			    &msgtype, 1);
1895 			log_warnx("received message with unknown type %u",
1896 			    msgtype);
1897 			bgp_fsm(p, EVNT_CON_FATAL);
1898 		}
1899 		rpos += msglen;
1900 		if (++processed > MSG_PROCESS_LIMIT) {
1901 			p->rpending = 1;
1902 			break;
1903 		}
1904 	}
1905 
1906 	if (rpos < av) {
1907 		left = av - rpos;
1908 		memmove(&p->rbuf->buf, p->rbuf->buf + rpos, left);
1909 		p->rbuf->wpos = left;
1910 	} else
1911 		p->rbuf->wpos = 0;
1912 }
1913 
1914 int
1915 parse_header(struct peer *peer, u_char *data, u_int16_t *len, u_int8_t *type)
1916 {
1917 	u_char			*p;
1918 	u_int16_t		 olen;
1919 	static const u_int8_t	 marker[MSGSIZE_HEADER_MARKER] = { 0xff, 0xff,
1920 				    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
1921 				    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1922 
1923 	/* caller MUST make sure we are getting 19 bytes! */
1924 	p = data;
1925 	if (memcmp(p, marker, sizeof(marker))) {
1926 		log_peer_warnx(&peer->conf, "sync error");
1927 		session_notification(peer, ERR_HEADER, ERR_HDR_SYNC, NULL, 0);
1928 		bgp_fsm(peer, EVNT_CON_FATAL);
1929 		return (-1);
1930 	}
1931 	p += MSGSIZE_HEADER_MARKER;
1932 
1933 	memcpy(&olen, p, 2);
1934 	*len = ntohs(olen);
1935 	p += 2;
1936 	memcpy(type, p, 1);
1937 
1938 	if (*len < MSGSIZE_HEADER || *len > MAX_PKTSIZE) {
1939 		log_peer_warnx(&peer->conf,
1940 		    "received message: illegal length: %u byte", *len);
1941 		session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1942 		    &olen, sizeof(olen));
1943 		bgp_fsm(peer, EVNT_CON_FATAL);
1944 		return (-1);
1945 	}
1946 
1947 	switch (*type) {
1948 	case OPEN:
1949 		if (*len < MSGSIZE_OPEN_MIN) {
1950 			log_peer_warnx(&peer->conf,
1951 			    "received OPEN: illegal len: %u byte", *len);
1952 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1953 			    &olen, sizeof(olen));
1954 			bgp_fsm(peer, EVNT_CON_FATAL);
1955 			return (-1);
1956 		}
1957 		break;
1958 	case NOTIFICATION:
1959 		if (*len < MSGSIZE_NOTIFICATION_MIN) {
1960 			log_peer_warnx(&peer->conf,
1961 			    "received NOTIFICATION: illegal len: %u byte",
1962 			    *len);
1963 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1964 			    &olen, sizeof(olen));
1965 			bgp_fsm(peer, EVNT_CON_FATAL);
1966 			return (-1);
1967 		}
1968 		break;
1969 	case UPDATE:
1970 		if (*len < MSGSIZE_UPDATE_MIN) {
1971 			log_peer_warnx(&peer->conf,
1972 			    "received UPDATE: illegal len: %u byte", *len);
1973 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1974 			    &olen, sizeof(olen));
1975 			bgp_fsm(peer, EVNT_CON_FATAL);
1976 			return (-1);
1977 		}
1978 		break;
1979 	case KEEPALIVE:
1980 		if (*len != MSGSIZE_KEEPALIVE) {
1981 			log_peer_warnx(&peer->conf,
1982 			    "received KEEPALIVE: illegal len: %u byte", *len);
1983 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1984 			    &olen, sizeof(olen));
1985 			bgp_fsm(peer, EVNT_CON_FATAL);
1986 			return (-1);
1987 		}
1988 		break;
1989 	case RREFRESH:
1990 		if (*len != MSGSIZE_RREFRESH) {
1991 			log_peer_warnx(&peer->conf,
1992 			    "received RREFRESH: illegal len: %u byte", *len);
1993 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1994 			    &olen, sizeof(olen));
1995 			bgp_fsm(peer, EVNT_CON_FATAL);
1996 			return (-1);
1997 		}
1998 		break;
1999 	default:
2000 		log_peer_warnx(&peer->conf,
2001 		    "received msg with unknown type %u", *type);
2002 		session_notification(peer, ERR_HEADER, ERR_HDR_TYPE,
2003 		    type, 1);
2004 		bgp_fsm(peer, EVNT_CON_FATAL);
2005 		return (-1);
2006 	}
2007 	return (0);
2008 }
2009 
2010 int
2011 parse_open(struct peer *peer)
2012 {
2013 	u_char		*p, *op_val;
2014 	u_int8_t	 version, rversion;
2015 	u_int16_t	 short_as, msglen;
2016 	u_int16_t	 holdtime, oholdtime, myholdtime;
2017 	u_int32_t	 as, bgpid;
2018 	u_int8_t	 optparamlen, plen;
2019 	u_int8_t	 op_type, op_len;
2020 
2021 	p = peer->rbuf->rptr;
2022 	p += MSGSIZE_HEADER_MARKER;
2023 	memcpy(&msglen, p, sizeof(msglen));
2024 	msglen = ntohs(msglen);
2025 
2026 	p = peer->rbuf->rptr;
2027 	p += MSGSIZE_HEADER;	/* header is already checked */
2028 
2029 	memcpy(&version, p, sizeof(version));
2030 	p += sizeof(version);
2031 
2032 	if (version != BGP_VERSION) {
2033 		log_peer_warnx(&peer->conf,
2034 		    "peer wants unrecognized version %u", version);
2035 		if (version > BGP_VERSION)
2036 			rversion = version - BGP_VERSION;
2037 		else
2038 			rversion = BGP_VERSION;
2039 		session_notification(peer, ERR_OPEN, ERR_OPEN_VERSION,
2040 		    &rversion, sizeof(rversion));
2041 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2042 		return (-1);
2043 	}
2044 
2045 	memcpy(&short_as, p, sizeof(short_as));
2046 	p += sizeof(short_as);
2047 	as = peer->short_as = ntohs(short_as);
2048 	if (as == 0) {
2049 		log_peer_warnx(&peer->conf,
2050 		    "peer requests unacceptable AS %u", as);
2051 		session_notification(peer, ERR_OPEN, ERR_OPEN_AS,
2052 		    NULL, 0);
2053 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2054 		return (-1);
2055 	}
2056 
2057 	memcpy(&oholdtime, p, sizeof(oholdtime));
2058 	p += sizeof(oholdtime);
2059 
2060 	holdtime = ntohs(oholdtime);
2061 	if (holdtime && holdtime < peer->conf.min_holdtime) {
2062 		log_peer_warnx(&peer->conf,
2063 		    "peer requests unacceptable holdtime %u", holdtime);
2064 		session_notification(peer, ERR_OPEN, ERR_OPEN_HOLDTIME,
2065 		    NULL, 0);
2066 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2067 		return (-1);
2068 	}
2069 
2070 	myholdtime = peer->conf.holdtime;
2071 	if (!myholdtime)
2072 		myholdtime = conf->holdtime;
2073 	if (holdtime < myholdtime)
2074 		peer->holdtime = holdtime;
2075 	else
2076 		peer->holdtime = myholdtime;
2077 
2078 	memcpy(&bgpid, p, sizeof(bgpid));
2079 	p += sizeof(bgpid);
2080 
2081 	/* check bgpid for validity - just disallow 0 */
2082 	if (ntohl(bgpid) == 0) {
2083 		log_peer_warnx(&peer->conf, "peer BGPID %u unacceptable",
2084 		    ntohl(bgpid));
2085 		session_notification(peer, ERR_OPEN, ERR_OPEN_BGPID,
2086 		    NULL, 0);
2087 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2088 		return (-1);
2089 	}
2090 	peer->remote_bgpid = bgpid;
2091 
2092 	memcpy(&optparamlen, p, sizeof(optparamlen));
2093 	p += sizeof(optparamlen);
2094 
2095 	if (optparamlen != msglen - MSGSIZE_OPEN_MIN) {
2096 			log_peer_warnx(&peer->conf,
2097 			    "corrupt OPEN message received: length mismatch");
2098 			session_notification(peer, ERR_OPEN, 0, NULL, 0);
2099 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2100 			return (-1);
2101 	}
2102 
2103 	plen = optparamlen;
2104 	while (plen > 0) {
2105 		if (plen < 2) {
2106 			log_peer_warnx(&peer->conf,
2107 			    "corrupt OPEN message received, len wrong");
2108 			session_notification(peer, ERR_OPEN, 0, NULL, 0);
2109 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2110 			return (-1);
2111 		}
2112 		memcpy(&op_type, p, sizeof(op_type));
2113 		p += sizeof(op_type);
2114 		plen -= sizeof(op_type);
2115 		memcpy(&op_len, p, sizeof(op_len));
2116 		p += sizeof(op_len);
2117 		plen -= sizeof(op_len);
2118 		if (op_len > 0) {
2119 			if (plen < op_len) {
2120 				log_peer_warnx(&peer->conf,
2121 				    "corrupt OPEN message received, len wrong");
2122 				session_notification(peer, ERR_OPEN, 0,
2123 				    NULL, 0);
2124 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2125 				return (-1);
2126 			}
2127 			op_val = p;
2128 			p += op_len;
2129 			plen -= op_len;
2130 		} else
2131 			op_val = NULL;
2132 
2133 		switch (op_type) {
2134 		case OPT_PARAM_CAPABILITIES:		/* RFC 3392 */
2135 			if (parse_capabilities(peer, op_val, op_len,
2136 			    &as) == -1) {
2137 				session_notification(peer, ERR_OPEN, 0,
2138 				    NULL, 0);
2139 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2140 				return (-1);
2141 			}
2142 			break;
2143 		case OPT_PARAM_AUTH:			/* deprecated */
2144 		default:
2145 			/*
2146 			 * unsupported type
2147 			 * the RFCs tell us to leave the data section empty
2148 			 * and notify the peer with ERR_OPEN, ERR_OPEN_OPT.
2149 			 * How the peer should know _which_ optional parameter
2150 			 * we don't support is beyond me.
2151 			 */
2152 			log_peer_warnx(&peer->conf,
2153 			    "received OPEN message with unsupported optional "
2154 			    "parameter: type %u", op_type);
2155 			session_notification(peer, ERR_OPEN, ERR_OPEN_OPT,
2156 				NULL, 0);
2157 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2158 			/* no punish */
2159 			timer_set(&peer->timers, Timer_IdleHold, 0);
2160 			peer->IdleHoldTime /= 2;
2161 			return (-1);
2162 		}
2163 	}
2164 
2165 	/* if remote-as is zero and it's a cloned neighbor, accept any */
2166 	if (peer->template && !peer->conf.remote_as && as != AS_TRANS) {
2167 		peer->conf.remote_as = as;
2168 		peer->conf.ebgp = (peer->conf.remote_as != peer->conf.local_as);
2169 		if (!peer->conf.ebgp)
2170 			/* force enforce_as off for iBGP sessions */
2171 			peer->conf.enforce_as = ENFORCE_AS_OFF;
2172 	}
2173 
2174 	if (peer->conf.remote_as != as) {
2175 		log_peer_warnx(&peer->conf, "peer sent wrong AS %s",
2176 		    log_as(as));
2177 		session_notification(peer, ERR_OPEN, ERR_OPEN_AS, NULL, 0);
2178 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2179 		return (-1);
2180 	}
2181 
2182 	if (capa_neg_calc(peer) == -1) {
2183 		log_peer_warnx(&peer->conf,
2184 		    "capability negotiation calculation failed");
2185 		session_notification(peer, ERR_OPEN, 0, NULL, 0);
2186 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2187 		return (-1);
2188 	}
2189 
2190 	return (0);
2191 }
2192 
2193 int
2194 parse_update(struct peer *peer)
2195 {
2196 	u_char		*p;
2197 	u_int16_t	 datalen;
2198 
2199 	/*
2200 	 * we pass the message verbatim to the rde.
2201 	 * in case of errors the whole session is reset with a
2202 	 * notification anyway, we only need to know the peer
2203 	 */
2204 	p = peer->rbuf->rptr;
2205 	p += MSGSIZE_HEADER_MARKER;
2206 	memcpy(&datalen, p, sizeof(datalen));
2207 	datalen = ntohs(datalen);
2208 
2209 	p = peer->rbuf->rptr;
2210 	p += MSGSIZE_HEADER;	/* header is already checked */
2211 	datalen -= MSGSIZE_HEADER;
2212 
2213 	if (imsg_rde(IMSG_UPDATE, peer->conf.id, p, datalen) == -1)
2214 		return (-1);
2215 
2216 	return (0);
2217 }
2218 
2219 int
2220 parse_refresh(struct peer *peer)
2221 {
2222 	u_char		*p;
2223 	u_int16_t	 afi;
2224 	u_int8_t	 aid, safi;
2225 
2226 	p = peer->rbuf->rptr;
2227 	p += MSGSIZE_HEADER;	/* header is already checked */
2228 
2229 	/*
2230 	 * We could check if we actually announced the capability but
2231 	 * as long as the message is correctly encoded we don't care.
2232 	 */
2233 
2234 	/* afi, 2 byte */
2235 	memcpy(&afi, p, sizeof(afi));
2236 	afi = ntohs(afi);
2237 	p += 2;
2238 	/* reserved, 1 byte */
2239 	p += 1;
2240 	/* safi, 1 byte */
2241 	memcpy(&safi, p, sizeof(safi));
2242 
2243 	/* afi/safi unchecked -	unrecognized values will be ignored anyway */
2244 	if (afi2aid(afi, safi, &aid) == -1) {
2245 		log_peer_warnx(&peer->conf, "peer sent bad refresh, "
2246 		    "invalid afi/safi pair");
2247 		return (0);
2248 	}
2249 
2250 	if (imsg_rde(IMSG_REFRESH, peer->conf.id, &aid, sizeof(aid)) == -1)
2251 		return (-1);
2252 
2253 	return (0);
2254 }
2255 
2256 int
2257 parse_notification(struct peer *peer)
2258 {
2259 	u_char		*p;
2260 	u_int16_t	 datalen;
2261 	u_int8_t	 errcode;
2262 	u_int8_t	 subcode;
2263 	u_int8_t	 capa_code;
2264 	u_int8_t	 capa_len;
2265 	size_t		 reason_len;
2266 	u_int8_t	 i;
2267 
2268 	/* just log */
2269 	p = peer->rbuf->rptr;
2270 	p += MSGSIZE_HEADER_MARKER;
2271 	memcpy(&datalen, p, sizeof(datalen));
2272 	datalen = ntohs(datalen);
2273 
2274 	p = peer->rbuf->rptr;
2275 	p += MSGSIZE_HEADER;	/* header is already checked */
2276 	datalen -= MSGSIZE_HEADER;
2277 
2278 	memcpy(&errcode, p, sizeof(errcode));
2279 	p += sizeof(errcode);
2280 	datalen -= sizeof(errcode);
2281 
2282 	memcpy(&subcode, p, sizeof(subcode));
2283 	p += sizeof(subcode);
2284 	datalen -= sizeof(subcode);
2285 
2286 	log_notification(peer, errcode, subcode, p, datalen, "received");
2287 	peer->errcnt++;
2288 	peer->stats.last_rcvd_errcode = errcode;
2289 	peer->stats.last_rcvd_suberr = subcode;
2290 
2291 	if (errcode == ERR_OPEN && subcode == ERR_OPEN_CAPA) {
2292 		if (datalen == 0) {	/* zebra likes to send those.. humbug */
2293 			log_peer_warnx(&peer->conf, "received \"unsupported "
2294 			    "capability\" notification without data part, "
2295 			    "disabling capability announcements altogether");
2296 			session_capa_ann_none(peer);
2297 		}
2298 
2299 		while (datalen > 0) {
2300 			if (datalen < 2) {
2301 				log_peer_warnx(&peer->conf,
2302 				    "parse_notification: "
2303 				    "expect len >= 2, len is %u", datalen);
2304 				return (-1);
2305 			}
2306 			memcpy(&capa_code, p, sizeof(capa_code));
2307 			p += sizeof(capa_code);
2308 			datalen -= sizeof(capa_code);
2309 			memcpy(&capa_len, p, sizeof(capa_len));
2310 			p += sizeof(capa_len);
2311 			datalen -= sizeof(capa_len);
2312 			if (datalen < capa_len) {
2313 				log_peer_warnx(&peer->conf,
2314 				    "parse_notification: capa_len %u exceeds "
2315 				    "remaining msg length %u", capa_len,
2316 				    datalen);
2317 				return (-1);
2318 			}
2319 			p += capa_len;
2320 			datalen -= capa_len;
2321 			switch (capa_code) {
2322 			case CAPA_MP:
2323 				for (i = 0; i < AID_MAX; i++)
2324 					peer->capa.ann.mp[i] = 0;
2325 				log_peer_warnx(&peer->conf,
2326 				    "disabling multiprotocol capability");
2327 				break;
2328 			case CAPA_REFRESH:
2329 				peer->capa.ann.refresh = 0;
2330 				log_peer_warnx(&peer->conf,
2331 				    "disabling route refresh capability");
2332 				break;
2333 			case CAPA_RESTART:
2334 				peer->capa.ann.grestart.restart = 0;
2335 				log_peer_warnx(&peer->conf,
2336 				    "disabling restart capability");
2337 				break;
2338 			case CAPA_AS4BYTE:
2339 				peer->capa.ann.as4byte = 0;
2340 				log_peer_warnx(&peer->conf,
2341 				    "disabling 4-byte AS num capability");
2342 				break;
2343 			default:	/* should not happen... */
2344 				log_peer_warnx(&peer->conf, "received "
2345 				    "\"unsupported capability\" notification "
2346 				    "for unknown capability %u, disabling "
2347 				    "capability announcements altogether",
2348 				    capa_code);
2349 				session_capa_ann_none(peer);
2350 				break;
2351 			}
2352 		}
2353 
2354 		return (1);
2355 	}
2356 
2357 	if (errcode == ERR_OPEN && subcode == ERR_OPEN_OPT) {
2358 		session_capa_ann_none(peer);
2359 		return (1);
2360 	}
2361 
2362 	if (errcode == ERR_CEASE &&
2363 	    (subcode == ERR_CEASE_ADMIN_DOWN ||
2364 	     subcode == ERR_CEASE_ADMIN_RESET)) {
2365 		if (datalen > 1) {
2366 			reason_len = *p++;
2367 			datalen--;
2368 			if (datalen < reason_len) {
2369 			    log_peer_warnx(&peer->conf,
2370 				"received truncated shutdown reason");
2371 			    return (0);
2372 			}
2373 			if (reason_len > REASON_LEN - 1) {
2374 			    log_peer_warnx(&peer->conf,
2375 				"received overly long shutdown reason");
2376 			    return (0);
2377 			}
2378 			memcpy(peer->stats.last_reason, p, reason_len);
2379 			peer->stats.last_reason[reason_len] = '\0';
2380 			log_peer_warnx(&peer->conf,
2381 			    "received shutdown reason: \"%s\"",
2382 			    log_reason(peer->stats.last_reason));
2383 			p += reason_len;
2384 			datalen -= reason_len;
2385 		}
2386 	}
2387 
2388 	return (0);
2389 }
2390 
2391 int
2392 parse_capabilities(struct peer *peer, u_char *d, u_int16_t dlen, u_int32_t *as)
2393 {
2394 	u_char		*capa_val;
2395 	u_int32_t	 remote_as;
2396 	u_int16_t	 len;
2397 	u_int16_t	 afi;
2398 	u_int16_t	 gr_header;
2399 	u_int8_t	 safi;
2400 	u_int8_t	 aid;
2401 	u_int8_t	 gr_flags;
2402 	u_int8_t	 capa_code;
2403 	u_int8_t	 capa_len;
2404 	u_int8_t	 i;
2405 
2406 	len = dlen;
2407 	while (len > 0) {
2408 		if (len < 2) {
2409 			log_peer_warnx(&peer->conf, "Bad capabilities attr "
2410 			    "length: %u, too short", len);
2411 			return (-1);
2412 		}
2413 		memcpy(&capa_code, d, sizeof(capa_code));
2414 		d += sizeof(capa_code);
2415 		len -= sizeof(capa_code);
2416 		memcpy(&capa_len, d, sizeof(capa_len));
2417 		d += sizeof(capa_len);
2418 		len -= sizeof(capa_len);
2419 		if (capa_len > 0) {
2420 			if (len < capa_len) {
2421 				log_peer_warnx(&peer->conf,
2422 				    "Bad capabilities attr length: "
2423 				    "len %u smaller than capa_len %u",
2424 				    len, capa_len);
2425 				return (-1);
2426 			}
2427 			capa_val = d;
2428 			d += capa_len;
2429 			len -= capa_len;
2430 		} else
2431 			capa_val = NULL;
2432 
2433 		switch (capa_code) {
2434 		case CAPA_MP:			/* RFC 4760 */
2435 			if (capa_len != 4) {
2436 				log_peer_warnx(&peer->conf,
2437 				    "Bad multi protocol capability length: "
2438 				    "%u", capa_len);
2439 				break;
2440 			}
2441 			memcpy(&afi, capa_val, sizeof(afi));
2442 			afi = ntohs(afi);
2443 			memcpy(&safi, capa_val + 3, sizeof(safi));
2444 			if (afi2aid(afi, safi, &aid) == -1) {
2445 				log_peer_warnx(&peer->conf,
2446 				    "Received multi protocol capability: "
2447 				    " unknown AFI %u, safi %u pair",
2448 				    afi, safi);
2449 				break;
2450 			}
2451 			peer->capa.peer.mp[aid] = 1;
2452 			break;
2453 		case CAPA_REFRESH:
2454 			peer->capa.peer.refresh = 1;
2455 			break;
2456 		case CAPA_RESTART:
2457 			if (capa_len == 2) {
2458 				/* peer only supports EoR marker */
2459 				peer->capa.peer.grestart.restart = 1;
2460 				peer->capa.peer.grestart.timeout = 0;
2461 				break;
2462 			} else if (capa_len % 4 != 2) {
2463 				log_peer_warnx(&peer->conf,
2464 				    "Bad graceful restart capability length: "
2465 				    "%u", capa_len);
2466 				peer->capa.peer.grestart.restart = 0;
2467 				peer->capa.peer.grestart.timeout = 0;
2468 				break;
2469 			}
2470 
2471 			memcpy(&gr_header, capa_val, sizeof(gr_header));
2472 			gr_header = ntohs(gr_header);
2473 			peer->capa.peer.grestart.timeout =
2474 			    gr_header & CAPA_GR_TIMEMASK;
2475 			if (peer->capa.peer.grestart.timeout == 0) {
2476 				log_peer_warnx(&peer->conf, "Received "
2477 				    "graceful restart timeout is zero");
2478 				peer->capa.peer.grestart.restart = 0;
2479 				break;
2480 			}
2481 
2482 			for (i = 2; i <= capa_len - 4; i += 4) {
2483 				memcpy(&afi, capa_val + i, sizeof(afi));
2484 				afi = ntohs(afi);
2485 				memcpy(&safi, capa_val + i + 2, sizeof(safi));
2486 				if (afi2aid(afi, safi, &aid) == -1) {
2487 					log_peer_warnx(&peer->conf,
2488 					    "Received graceful restart capa: "
2489 					    " unknown AFI %u, safi %u pair",
2490 					    afi, safi);
2491 					continue;
2492 				}
2493 				memcpy(&gr_flags, capa_val + i + 3,
2494 				    sizeof(gr_flags));
2495 				peer->capa.peer.grestart.flags[aid] |=
2496 				    CAPA_GR_PRESENT;
2497 				if (gr_flags & CAPA_GR_F_FLAG)
2498 					peer->capa.peer.grestart.flags[aid] |=
2499 					    CAPA_GR_FORWARD;
2500 				if (gr_header & CAPA_GR_R_FLAG)
2501 					peer->capa.peer.grestart.flags[aid] |=
2502 					    CAPA_GR_RESTART;
2503 				peer->capa.peer.grestart.restart = 2;
2504 			}
2505 			break;
2506 		case CAPA_AS4BYTE:
2507 			if (capa_len != 4) {
2508 				log_peer_warnx(&peer->conf,
2509 				    "Bad AS4BYTE capability length: "
2510 				    "%u", capa_len);
2511 				peer->capa.peer.as4byte = 0;
2512 				break;
2513 			}
2514 			memcpy(&remote_as, capa_val, sizeof(remote_as));
2515 			*as = ntohl(remote_as);
2516 			if (*as == 0) {
2517 				log_peer_warnx(&peer->conf,
2518 				    "peer requests unacceptable AS %u", *as);
2519 				session_notification(peer, ERR_OPEN,
2520 				    ERR_OPEN_AS, NULL, 0);
2521 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2522 				return (-1);
2523 			}
2524 			peer->capa.peer.as4byte = 1;
2525 			break;
2526 		default:
2527 			break;
2528 		}
2529 	}
2530 
2531 	return (0);
2532 }
2533 
2534 int
2535 capa_neg_calc(struct peer *p)
2536 {
2537 	u_int8_t	i, hasmp = 0;
2538 
2539 	/* refresh: does not realy matter here, use peer setting */
2540 	p->capa.neg.refresh = p->capa.peer.refresh;
2541 
2542 	/* as4byte: both side must announce capability */
2543 	if (p->capa.ann.as4byte && p->capa.peer.as4byte)
2544 		p->capa.neg.as4byte = 1;
2545 	else
2546 		p->capa.neg.as4byte = 0;
2547 
2548 	/* MP: both side must announce capability */
2549 	for (i = 0; i < AID_MAX; i++) {
2550 		if (p->capa.ann.mp[i] && p->capa.peer.mp[i]) {
2551 			p->capa.neg.mp[i] = 1;
2552 			hasmp = 1;
2553 		} else
2554 			p->capa.neg.mp[i] = 0;
2555 	}
2556 	/* if no MP capability present default to IPv4 unicast mode */
2557 	if (!hasmp)
2558 		p->capa.neg.mp[AID_INET] = 1;
2559 
2560 	/*
2561 	 * graceful restart: only the peer capabilities are of interest here.
2562 	 * It is necessary to compare the new values with the previous ones
2563 	 * and act acordingly. AFI/SAFI that are not part in the MP capability
2564 	 * are treated as not being present.
2565 	 */
2566 
2567 	for (i = 0; i < AID_MAX; i++) {
2568 		int8_t	negflags;
2569 
2570 		/* disable GR if the AFI/SAFI is not present */
2571 		if (p->capa.peer.grestart.flags[i] & CAPA_GR_PRESENT &&
2572 		    p->capa.neg.mp[i] == 0)
2573 			p->capa.peer.grestart.flags[i] = 0;	/* disable */
2574 		/* look at current GR state and decide what to do */
2575 		negflags = p->capa.neg.grestart.flags[i];
2576 		p->capa.neg.grestart.flags[i] = p->capa.peer.grestart.flags[i];
2577 		if (negflags & CAPA_GR_RESTARTING) {
2578 			if (!(p->capa.peer.grestart.flags[i] &
2579 			    CAPA_GR_FORWARD)) {
2580 				if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
2581 				    &i, sizeof(i)) == -1)
2582 					return (-1);
2583 				log_peer_warnx(&p->conf, "graceful restart of "
2584 				    "%s, not restarted, flushing", aid2str(i));
2585 			} else
2586 				p->capa.neg.grestart.flags[i] |=
2587 				    CAPA_GR_RESTARTING;
2588 		}
2589 	}
2590 	p->capa.neg.grestart.timeout = p->capa.peer.grestart.timeout;
2591 	p->capa.neg.grestart.restart = p->capa.peer.grestart.restart;
2592 
2593 	return (0);
2594 }
2595 
2596 void
2597 session_dispatch_imsg(struct imsgbuf *ibuf, int idx, u_int *listener_cnt)
2598 {
2599 	struct imsg		 imsg;
2600 	struct mrt		 xmrt;
2601 	struct mrt		*mrt;
2602 	struct imsgbuf		*i;
2603 	struct peer		*p;
2604 	struct listen_addr	*la, *nla;
2605 	struct kif		*kif;
2606 	u_char			*data;
2607 	int			 n, fd, depend_ok, restricted;
2608 	u_int16_t		 t;
2609 	u_int8_t		 aid, errcode, subcode;
2610 
2611 	while (ibuf) {
2612 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2613 			fatal("session_dispatch_imsg: imsg_get error");
2614 
2615 		if (n == 0)
2616 			break;
2617 
2618 		switch (imsg.hdr.type) {
2619 		case IMSG_SOCKET_CONN:
2620 		case IMSG_SOCKET_CONN_CTL:
2621 			if (idx != PFD_PIPE_MAIN)
2622 				fatalx("reconf request not from parent");
2623 			if ((fd = imsg.fd) == -1) {
2624 				log_warnx("expected to receive imsg fd to "
2625 				    "RDE but didn't receive any");
2626 				break;
2627 			}
2628 			if ((i = malloc(sizeof(struct imsgbuf))) == NULL)
2629 				fatal(NULL);
2630 			imsg_init(i, fd);
2631 			if (imsg.hdr.type == IMSG_SOCKET_CONN) {
2632 				if (ibuf_rde) {
2633 					log_warnx("Unexpected imsg connection "
2634 					    "to RDE received");
2635 					msgbuf_clear(&ibuf_rde->w);
2636 					free(ibuf_rde);
2637 				}
2638 				ibuf_rde = i;
2639 			} else {
2640 				if (ibuf_rde_ctl) {
2641 					log_warnx("Unexpected imsg ctl "
2642 					    "connection to RDE received");
2643 					msgbuf_clear(&ibuf_rde_ctl->w);
2644 					free(ibuf_rde_ctl);
2645 				}
2646 				ibuf_rde_ctl = i;
2647 			}
2648 			break;
2649 		case IMSG_RECONF_CONF:
2650 			if (idx != PFD_PIPE_MAIN)
2651 				fatalx("reconf request not from parent");
2652 			nconf = new_config();
2653 
2654 			copy_config(nconf, imsg.data);
2655 			pending_reconf = 1;
2656 			break;
2657 		case IMSG_RECONF_PEER:
2658 			if (idx != PFD_PIPE_MAIN)
2659 				fatalx("reconf request not from parent");
2660 			if ((p = calloc(1, sizeof(struct peer))) == NULL)
2661 				fatal("new_peer");
2662 			memcpy(&p->conf, imsg.data, sizeof(struct peer_config));
2663 			p->state = p->prev_state = STATE_NONE;
2664 			p->reconf_action = RECONF_REINIT;
2665 			if (RB_INSERT(peer_head, &nconf->peers, p) != NULL)
2666 				fatalx("%s: peer tree is corrupt", __func__);
2667 			break;
2668 		case IMSG_RECONF_LISTENER:
2669 			if (idx != PFD_PIPE_MAIN)
2670 				fatalx("reconf request not from parent");
2671 			if (nconf == NULL)
2672 				fatalx("IMSG_RECONF_LISTENER but no config");
2673 			nla = imsg.data;
2674 			TAILQ_FOREACH(la, conf->listen_addrs, entry)
2675 				if (!la_cmp(la, nla))
2676 					break;
2677 
2678 			if (la == NULL) {
2679 				if (nla->reconf != RECONF_REINIT)
2680 					fatalx("king bula sez: "
2681 					    "expected REINIT");
2682 
2683 				if ((nla->fd = imsg.fd) == -1)
2684 					log_warnx("expected to receive fd for "
2685 					    "%s but didn't receive any",
2686 					    log_sockaddr((struct sockaddr *)
2687 					    &nla->sa, nla->sa_len));
2688 
2689 				la = calloc(1, sizeof(struct listen_addr));
2690 				if (la == NULL)
2691 					fatal(NULL);
2692 				memcpy(&la->sa, &nla->sa, sizeof(la->sa));
2693 				la->flags = nla->flags;
2694 				la->fd = nla->fd;
2695 				la->reconf = RECONF_REINIT;
2696 				TAILQ_INSERT_TAIL(nconf->listen_addrs, la,
2697 				    entry);
2698 			} else {
2699 				if (nla->reconf != RECONF_KEEP)
2700 					fatalx("king bula sez: expected KEEP");
2701 				la->reconf = RECONF_KEEP;
2702 			}
2703 
2704 			break;
2705 		case IMSG_RECONF_CTRL:
2706 			if (idx != PFD_PIPE_MAIN)
2707 				fatalx("reconf request not from parent");
2708 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
2709 			    sizeof(restricted))
2710 				fatalx("IFINFO imsg with wrong len");
2711 			memcpy(&restricted, imsg.data, sizeof(restricted));
2712 			if (imsg.fd == -1) {
2713 				log_warnx("expected to receive fd for control "
2714 				    "socket but didn't receive any");
2715 				break;
2716 			}
2717 			if (restricted) {
2718 				control_shutdown(rcsock);
2719 				rcsock = imsg.fd;
2720 			} else {
2721 				control_shutdown(csock);
2722 				csock = imsg.fd;
2723 			}
2724 			break;
2725 		case IMSG_RECONF_DRAIN:
2726 			if (idx != PFD_PIPE_MAIN)
2727 				fatalx("reconf request not from parent");
2728 			imsg_compose(ibuf_main, IMSG_RECONF_DRAIN, 0, 0,
2729 			    -1, NULL, 0);
2730 			break;
2731 		case IMSG_RECONF_DONE:
2732 			if (idx != PFD_PIPE_MAIN)
2733 				fatalx("reconf request not from parent");
2734 			if (nconf == NULL)
2735 				fatalx("got IMSG_RECONF_DONE but no config");
2736 			copy_config(conf, nconf);
2737 			merge_peers(conf, nconf);
2738 
2739 			/* delete old listeners */
2740 			for (la = TAILQ_FIRST(conf->listen_addrs); la != NULL;
2741 			    la = nla) {
2742 				nla = TAILQ_NEXT(la, entry);
2743 				if (la->reconf == RECONF_NONE) {
2744 					log_info("not listening on %s any more",
2745 					    log_sockaddr((struct sockaddr *)
2746 					    &la->sa, la->sa_len));
2747 					TAILQ_REMOVE(conf->listen_addrs, la,
2748 					    entry);
2749 					close(la->fd);
2750 					free(la);
2751 				}
2752 			}
2753 
2754 			/* add new listeners */
2755 			TAILQ_CONCAT(conf->listen_addrs, nconf->listen_addrs,
2756 			    entry);
2757 
2758 			setup_listeners(listener_cnt);
2759 			free_config(nconf);
2760 			nconf = NULL;
2761 			pending_reconf = 0;
2762 			log_info("SE reconfigured");
2763 			imsg_compose(ibuf_main, IMSG_RECONF_DONE, 0, 0,
2764 			    -1, NULL, 0);
2765 			break;
2766 		case IMSG_IFINFO:
2767 			if (idx != PFD_PIPE_MAIN)
2768 				fatalx("IFINFO message not from parent");
2769 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
2770 			    sizeof(struct kif))
2771 				fatalx("IFINFO imsg with wrong len");
2772 			kif = imsg.data;
2773 			depend_ok = kif->depend_state;
2774 
2775 			RB_FOREACH(p, peer_head, &conf->peers)
2776 				if (!strcmp(p->conf.if_depend, kif->ifname)) {
2777 					if (depend_ok && !p->depend_ok) {
2778 						p->depend_ok = depend_ok;
2779 						bgp_fsm(p, EVNT_START);
2780 					} else if (!depend_ok && p->depend_ok) {
2781 						p->depend_ok = depend_ok;
2782 						session_stop(p,
2783 						    ERR_CEASE_OTHER_CHANGE);
2784 					}
2785 				}
2786 			break;
2787 		case IMSG_MRT_OPEN:
2788 		case IMSG_MRT_REOPEN:
2789 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2790 			    sizeof(struct mrt)) {
2791 				log_warnx("wrong imsg len");
2792 				break;
2793 			}
2794 
2795 			memcpy(&xmrt, imsg.data, sizeof(struct mrt));
2796 			if ((xmrt.wbuf.fd = imsg.fd) == -1)
2797 				log_warnx("expected to receive fd for mrt dump "
2798 				    "but didn't receive any");
2799 
2800 			mrt = mrt_get(&mrthead, &xmrt);
2801 			if (mrt == NULL) {
2802 				/* new dump */
2803 				mrt = calloc(1, sizeof(struct mrt));
2804 				if (mrt == NULL)
2805 					fatal("session_dispatch_imsg");
2806 				memcpy(mrt, &xmrt, sizeof(struct mrt));
2807 				TAILQ_INIT(&mrt->wbuf.bufs);
2808 				LIST_INSERT_HEAD(&mrthead, mrt, entry);
2809 			} else {
2810 				/* old dump reopened */
2811 				close(mrt->wbuf.fd);
2812 				mrt->wbuf.fd = xmrt.wbuf.fd;
2813 			}
2814 			break;
2815 		case IMSG_MRT_CLOSE:
2816 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2817 			    sizeof(struct mrt)) {
2818 				log_warnx("wrong imsg len");
2819 				break;
2820 			}
2821 
2822 			memcpy(&xmrt, imsg.data, sizeof(struct mrt));
2823 			mrt = mrt_get(&mrthead, &xmrt);
2824 			if (mrt != NULL)
2825 				mrt_done(mrt);
2826 			break;
2827 		case IMSG_CTL_KROUTE:
2828 		case IMSG_CTL_KROUTE_ADDR:
2829 		case IMSG_CTL_SHOW_NEXTHOP:
2830 		case IMSG_CTL_SHOW_INTERFACE:
2831 		case IMSG_CTL_SHOW_FIB_TABLES:
2832 		case IMSG_CTL_SHOW_RTR:
2833 		case IMSG_CTL_SHOW_TIMER:
2834 			if (idx != PFD_PIPE_MAIN)
2835 				fatalx("ctl kroute request not from parent");
2836 			control_imsg_relay(&imsg);
2837 			break;
2838 		case IMSG_CTL_SHOW_RIB:
2839 		case IMSG_CTL_SHOW_RIB_PREFIX:
2840 		case IMSG_CTL_SHOW_RIB_COMMUNITIES:
2841 		case IMSG_CTL_SHOW_RIB_ATTR:
2842 		case IMSG_CTL_SHOW_RIB_MEM:
2843 		case IMSG_CTL_SHOW_RIB_HASH:
2844 		case IMSG_CTL_SHOW_NETWORK:
2845 		case IMSG_CTL_SHOW_NEIGHBOR:
2846 		case IMSG_CTL_SHOW_SET:
2847 			if (idx != PFD_PIPE_ROUTE_CTL)
2848 				fatalx("ctl rib request not from RDE");
2849 			control_imsg_relay(&imsg);
2850 			break;
2851 		case IMSG_CTL_END:
2852 		case IMSG_CTL_RESULT:
2853 			control_imsg_relay(&imsg);
2854 			break;
2855 		case IMSG_UPDATE:
2856 			if (idx != PFD_PIPE_ROUTE)
2857 				fatalx("update request not from RDE");
2858 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2859 			    MAX_PKTSIZE - MSGSIZE_HEADER ||
2860 			    imsg.hdr.len < IMSG_HEADER_SIZE +
2861 			    MSGSIZE_UPDATE_MIN - MSGSIZE_HEADER)
2862 				log_warnx("RDE sent invalid update");
2863 			else
2864 				session_update(imsg.hdr.peerid, imsg.data,
2865 				    imsg.hdr.len - IMSG_HEADER_SIZE);
2866 			break;
2867 		case IMSG_UPDATE_ERR:
2868 			if (idx != PFD_PIPE_ROUTE)
2869 				fatalx("update request not from RDE");
2870 			if (imsg.hdr.len < IMSG_HEADER_SIZE + 2) {
2871 				log_warnx("RDE sent invalid notification");
2872 				break;
2873 			}
2874 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2875 				log_warnx("no such peer: id=%u",
2876 				    imsg.hdr.peerid);
2877 				break;
2878 			}
2879 			data = imsg.data;
2880 			errcode = *data++;
2881 			subcode = *data++;
2882 
2883 			if (imsg.hdr.len == IMSG_HEADER_SIZE + 2)
2884 				data = NULL;
2885 
2886 			session_notification(p, errcode, subcode,
2887 			    data, imsg.hdr.len - IMSG_HEADER_SIZE - 2);
2888 			switch (errcode) {
2889 			case ERR_CEASE:
2890 				switch (subcode) {
2891 				case ERR_CEASE_MAX_PREFIX:
2892 				case ERR_CEASE_MAX_SENT_PREFIX:
2893 					t = p->conf.max_out_prefix_restart;
2894 					if (subcode == ERR_CEASE_MAX_PREFIX)
2895 						t = p->conf.max_prefix_restart;
2896 
2897 					bgp_fsm(p, EVNT_STOP);
2898 					if (t)
2899 						timer_set(&p->timers,
2900 						    Timer_IdleHold, 60 * t);
2901 					break;
2902 				default:
2903 					bgp_fsm(p, EVNT_CON_FATAL);
2904 					break;
2905 				}
2906 				break;
2907 			default:
2908 				bgp_fsm(p, EVNT_CON_FATAL);
2909 				break;
2910 			}
2911 			break;
2912 		case IMSG_SESSION_RESTARTED:
2913 			if (idx != PFD_PIPE_ROUTE)
2914 				fatalx("update request not from RDE");
2915 			if (imsg.hdr.len < IMSG_HEADER_SIZE + sizeof(aid)) {
2916 				log_warnx("RDE sent invalid restart msg");
2917 				break;
2918 			}
2919 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2920 				log_warnx("no such peer: id=%u",
2921 				    imsg.hdr.peerid);
2922 				break;
2923 			}
2924 			memcpy(&aid, imsg.data, sizeof(aid));
2925 			if (aid >= AID_MAX)
2926 				fatalx("IMSG_SESSION_RESTARTED: bad AID");
2927 			if (p->capa.neg.grestart.flags[aid] &
2928 			    CAPA_GR_RESTARTING) {
2929 				log_peer_warnx(&p->conf,
2930 				    "graceful restart of %s finished",
2931 				    aid2str(aid));
2932 				p->capa.neg.grestart.flags[aid] &=
2933 				    ~CAPA_GR_RESTARTING;
2934 				timer_stop(&p->timers, Timer_RestartTimeout);
2935 
2936 				/* signal back to RDE to cleanup stale routes */
2937 				if (imsg_rde(IMSG_SESSION_RESTARTED,
2938 				    imsg.hdr.peerid, &aid, sizeof(aid)) == -1)
2939 					fatal("imsg_compose: "
2940 					    "IMSG_SESSION_RESTARTED");
2941 			}
2942 			break;
2943 		case IMSG_SESSION_DOWN:
2944 			if (idx != PFD_PIPE_ROUTE)
2945 				fatalx("update request not from RDE");
2946 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2947 				log_warnx("no such peer: id=%u",
2948 				    imsg.hdr.peerid);
2949 				break;
2950 			}
2951 			session_stop(p, ERR_CEASE_ADMIN_DOWN);
2952 			break;
2953 		default:
2954 			break;
2955 		}
2956 		imsg_free(&imsg);
2957 	}
2958 }
2959 
2960 int
2961 la_cmp(struct listen_addr *a, struct listen_addr *b)
2962 {
2963 	struct sockaddr_in	*in_a, *in_b;
2964 	struct sockaddr_in6	*in6_a, *in6_b;
2965 
2966 	if (a->sa.ss_family != b->sa.ss_family)
2967 		return (1);
2968 
2969 	switch (a->sa.ss_family) {
2970 	case AF_INET:
2971 		in_a = (struct sockaddr_in *)&a->sa;
2972 		in_b = (struct sockaddr_in *)&b->sa;
2973 		if (in_a->sin_addr.s_addr != in_b->sin_addr.s_addr)
2974 			return (1);
2975 		if (in_a->sin_port != in_b->sin_port)
2976 			return (1);
2977 		break;
2978 	case AF_INET6:
2979 		in6_a = (struct sockaddr_in6 *)&a->sa;
2980 		in6_b = (struct sockaddr_in6 *)&b->sa;
2981 		if (bcmp(&in6_a->sin6_addr, &in6_b->sin6_addr,
2982 		    sizeof(struct in6_addr)))
2983 			return (1);
2984 		if (in6_a->sin6_port != in6_b->sin6_port)
2985 			return (1);
2986 		break;
2987 	default:
2988 		fatal("king bula sez: unknown address family");
2989 		/* NOTREACHED */
2990 	}
2991 
2992 	return (0);
2993 }
2994 
2995 struct peer *
2996 getpeerbydesc(struct bgpd_config *c, const char *descr)
2997 {
2998 	struct peer	*p, *res = NULL;
2999 	int		 match = 0;
3000 
3001 	RB_FOREACH(p, peer_head, &c->peers)
3002 		if (!strcmp(p->conf.descr, descr)) {
3003 			res = p;
3004 			match++;
3005 		}
3006 
3007 	if (match > 1)
3008 		log_info("neighbor description \"%s\" not unique, request "
3009 		    "aborted", descr);
3010 
3011 	if (match == 1)
3012 		return (res);
3013 	else
3014 		return (NULL);
3015 }
3016 
3017 struct peer *
3018 getpeerbyip(struct bgpd_config *c, struct sockaddr *ip)
3019 {
3020 	struct bgpd_addr addr;
3021 	struct peer	*p, *newpeer, *loose = NULL;
3022 	u_int32_t	 id;
3023 
3024 	sa2addr(ip, &addr, NULL);
3025 
3026 	/* we might want a more effective way to find peers by IP */
3027 	RB_FOREACH(p, peer_head, &c->peers)
3028 		if (!p->conf.template &&
3029 		    !memcmp(&addr, &p->conf.remote_addr, sizeof(addr)))
3030 			return (p);
3031 
3032 	/* try template matching */
3033 	RB_FOREACH(p, peer_head, &c->peers)
3034 		if (p->conf.template &&
3035 		    p->conf.remote_addr.aid == addr.aid &&
3036 		    session_match_mask(p, &addr))
3037 			if (loose == NULL || loose->conf.remote_masklen <
3038 			    p->conf.remote_masklen)
3039 				loose = p;
3040 
3041 	if (loose != NULL) {
3042 		/* clone */
3043 		if ((newpeer = malloc(sizeof(struct peer))) == NULL)
3044 			fatal(NULL);
3045 		memcpy(newpeer, loose, sizeof(struct peer));
3046 		for (id = PEER_ID_DYN_MAX; id > PEER_ID_STATIC_MAX; id--) {
3047 			if (getpeerbyid(c, id) == NULL)	/* we found a free id */
3048 				break;
3049 		}
3050 		newpeer->template = loose;
3051 		session_template_clone(newpeer, ip, id, 0);
3052 		newpeer->state = newpeer->prev_state = STATE_NONE;
3053 		newpeer->reconf_action = RECONF_KEEP;
3054 		newpeer->rbuf = NULL;
3055 		newpeer->rpending = 0;
3056 		init_peer(newpeer);
3057 		bgp_fsm(newpeer, EVNT_START);
3058 		if (RB_INSERT(peer_head, &c->peers, newpeer) != NULL)
3059 			fatalx("%s: peer tree is corrupt", __func__);
3060 		return (newpeer);
3061 	}
3062 
3063 	return (NULL);
3064 }
3065 
3066 struct peer *
3067 getpeerbyid(struct bgpd_config *c, u_int32_t peerid)
3068 {
3069 	static struct peer lookup;
3070 
3071 	lookup.conf.id = peerid;
3072 
3073 	return RB_FIND(peer_head, &c->peers, &lookup);
3074 }
3075 
3076 int
3077 peer_matched(struct peer *p, struct ctl_neighbor *n)
3078 {
3079 	char *s;
3080 
3081 	if (n && n->addr.aid) {
3082 		if (memcmp(&p->conf.remote_addr, &n->addr,
3083 		    sizeof(p->conf.remote_addr)))
3084 			return 0;
3085 	} else if (n && n->descr[0]) {
3086 		s = n->is_group ? p->conf.group : p->conf.descr;
3087 		if (strcmp(s, n->descr))
3088 			return 0;
3089 	}
3090 	return 1;
3091 }
3092 
3093 void
3094 session_template_clone(struct peer *p, struct sockaddr *ip, u_int32_t id,
3095     u_int32_t as)
3096 {
3097 	struct bgpd_addr	remote_addr;
3098 
3099 	if (ip)
3100 		sa2addr(ip, &remote_addr, NULL);
3101 	else
3102 		memcpy(&remote_addr, &p->conf.remote_addr, sizeof(remote_addr));
3103 
3104 	memcpy(&p->conf, &p->template->conf, sizeof(struct peer_config));
3105 
3106 	p->conf.id = id;
3107 
3108 	if (as) {
3109 		p->conf.remote_as = as;
3110 		p->conf.ebgp = (p->conf.remote_as != p->conf.local_as);
3111 		if (!p->conf.ebgp)
3112 			/* force enforce_as off for iBGP sessions */
3113 			p->conf.enforce_as = ENFORCE_AS_OFF;
3114 	}
3115 
3116 	memcpy(&p->conf.remote_addr, &remote_addr, sizeof(remote_addr));
3117 	switch (p->conf.remote_addr.aid) {
3118 	case AID_INET:
3119 		p->conf.remote_masklen = 32;
3120 		break;
3121 	case AID_INET6:
3122 		p->conf.remote_masklen = 128;
3123 		break;
3124 	}
3125 	p->conf.template = 0;
3126 }
3127 
3128 int
3129 session_match_mask(struct peer *p, struct bgpd_addr *a)
3130 {
3131 	struct in_addr	 v4masked;
3132 	struct in6_addr	 v6masked;
3133 
3134 	switch (p->conf.remote_addr.aid) {
3135 	case AID_INET:
3136 		inet4applymask(&v4masked, &a->v4, p->conf.remote_masklen);
3137 		if (p->conf.remote_addr.v4.s_addr == v4masked.s_addr)
3138 			return (1);
3139 		return (0);
3140 	case AID_INET6:
3141 		inet6applymask(&v6masked, &a->v6, p->conf.remote_masklen);
3142 
3143 		if (memcmp(&v6masked, &p->conf.remote_addr.v6,
3144 		    sizeof(v6masked)) == 0)
3145 			return (1);
3146 		return (0);
3147 	}
3148 	return (0);
3149 }
3150 
3151 void
3152 session_down(struct peer *peer)
3153 {
3154 	bzero(&peer->capa.neg, sizeof(peer->capa.neg));
3155 	peer->stats.last_updown = getmonotime();
3156 	/*
3157 	 * session_down is called in the exit code path so check
3158 	 * if the RDE is still around, if not there is no need to
3159 	 * send the message.
3160 	 */
3161 	if (ibuf_rde == NULL)
3162 		return;
3163 	if (imsg_rde(IMSG_SESSION_DOWN, peer->conf.id, NULL, 0) == -1)
3164 		fatalx("imsg_compose error");
3165 }
3166 
3167 void
3168 session_up(struct peer *p)
3169 {
3170 	struct session_up	 sup;
3171 
3172 	if (imsg_rde(IMSG_SESSION_ADD, p->conf.id,
3173 	    &p->conf, sizeof(p->conf)) == -1)
3174 		fatalx("imsg_compose error");
3175 
3176 	if (p->local.aid == AID_INET) {
3177 		sup.local_v4_addr = p->local;
3178 		sup.local_v6_addr = p->local_alt;
3179 	} else {
3180 		sup.local_v6_addr = p->local;
3181 		sup.local_v4_addr = p->local_alt;
3182 	}
3183 	sup.remote_addr = p->remote;
3184 
3185 	sup.remote_bgpid = p->remote_bgpid;
3186 	sup.short_as = p->short_as;
3187 	memcpy(&sup.capa, &p->capa.neg, sizeof(sup.capa));
3188 	p->stats.last_updown = getmonotime();
3189 	if (imsg_rde(IMSG_SESSION_UP, p->conf.id, &sup, sizeof(sup)) == -1)
3190 		fatalx("imsg_compose error");
3191 }
3192 
3193 int
3194 imsg_ctl_parent(int type, u_int32_t peerid, pid_t pid, void *data,
3195     u_int16_t datalen)
3196 {
3197 	return (imsg_compose(ibuf_main, type, peerid, pid, -1, data, datalen));
3198 }
3199 
3200 int
3201 imsg_ctl_rde(int type, pid_t pid, void *data, u_int16_t datalen)
3202 {
3203 	if (ibuf_rde_ctl == NULL) {
3204 		log_warnx("Can't send message %u to RDE, ctl pipe closed",
3205 		    type);
3206 		return (0);
3207 	}
3208 	/*
3209 	 * Use control socket to talk to RDE to bypass the queue of the
3210 	 * regular imsg socket.
3211 	 */
3212 	return (imsg_compose(ibuf_rde_ctl, type, 0, pid, -1, data, datalen));
3213 }
3214 
3215 int
3216 imsg_rde(int type, uint32_t peerid, void *data, u_int16_t datalen)
3217 {
3218 	if (ibuf_rde == NULL) {
3219 		log_warnx("Can't send message %u to RDE, pipe closed", type);
3220 		return (0);
3221 	}
3222 
3223 	return (imsg_compose(ibuf_rde, type, peerid, 0, -1, data, datalen));
3224 }
3225 
3226 void
3227 session_demote(struct peer *p, int level)
3228 {
3229 	struct demote_msg	msg;
3230 
3231 	strlcpy(msg.demote_group, p->conf.demote_group,
3232 	    sizeof(msg.demote_group));
3233 	msg.level = level;
3234 	if (imsg_compose(ibuf_main, IMSG_DEMOTE, p->conf.id, 0, -1,
3235 	    &msg, sizeof(msg)) == -1)
3236 		fatalx("imsg_compose error");
3237 
3238 	p->demoted += level;
3239 }
3240 
3241 void
3242 session_stop(struct peer *peer, u_int8_t subcode)
3243 {
3244 	char data[REASON_LEN];
3245 	size_t datalen;
3246 	size_t reason_len;
3247 	char *communication;
3248 
3249 	datalen = 0;
3250 	communication = peer->conf.reason;
3251 
3252 	if ((subcode == ERR_CEASE_ADMIN_DOWN ||
3253 	    subcode == ERR_CEASE_ADMIN_RESET)
3254 	    && communication && *communication) {
3255 		reason_len = strlen(communication);
3256 		if (reason_len > REASON_LEN - 1) {
3257 		    log_peer_warnx(&peer->conf,
3258 			"trying to send overly long shutdown reason");
3259 		} else {
3260 			data[0] = reason_len;
3261 			datalen = reason_len + sizeof(data[0]);
3262 			memcpy(data + 1, communication, reason_len);
3263 		}
3264 	}
3265 	switch (peer->state) {
3266 	case STATE_OPENSENT:
3267 	case STATE_OPENCONFIRM:
3268 	case STATE_ESTABLISHED:
3269 		session_notification(peer, ERR_CEASE, subcode, data, datalen);
3270 		break;
3271 	default:
3272 		/* session not open, no need to send notification */
3273 		break;
3274 	}
3275 	bgp_fsm(peer, EVNT_STOP);
3276 }
3277 
3278 void
3279 merge_peers(struct bgpd_config *c, struct bgpd_config *nc)
3280 {
3281 	struct peer *p, *np, *next;
3282 
3283 	RB_FOREACH(p, peer_head, &c->peers) {
3284 		/* templates are handled specially */
3285 		if (p->template != NULL)
3286 			continue;
3287 		np = getpeerbyid(nc, p->conf.id);
3288 		if (np == NULL) {
3289 			p->reconf_action = RECONF_DELETE;
3290 			continue;
3291 		}
3292 
3293 		/* peer no longer uses TCP MD5SIG so deconfigure */
3294 		if (p->conf.auth.method == AUTH_MD5SIG &&
3295 		    np->conf.auth.method != AUTH_MD5SIG)
3296 			tcp_md5_del_listener(c, p);
3297 		else if (np->conf.auth.method == AUTH_MD5SIG)
3298 			tcp_md5_add_listener(c, np);
3299 
3300 		memcpy(&p->conf, &np->conf, sizeof(p->conf));
3301 		RB_REMOVE(peer_head, &nc->peers, np);
3302 		free(np);
3303 
3304 		p->reconf_action = RECONF_KEEP;
3305 
3306 		/* had demotion, is demoted, demote removed? */
3307 		if (p->demoted && !p->conf.demote_group[0])
3308 			session_demote(p, -1);
3309 
3310 		/* if session is not open then refresh pfkey data */
3311 		if (p->state < STATE_OPENSENT && !p->template)
3312 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
3313 			    p->conf.id, 0, -1, NULL, 0);
3314 
3315 		/* sync the RDE in case we keep the peer */
3316 		if (imsg_rde(IMSG_SESSION_ADD, p->conf.id,
3317 		    &p->conf, sizeof(struct peer_config)) == -1)
3318 			fatalx("imsg_compose error");
3319 
3320 		/* apply the config to all clones of a template */
3321 		if (p->conf.template) {
3322 			struct peer *xp;
3323 			RB_FOREACH(xp, peer_head, &c->peers) {
3324 				if (xp->template != p)
3325 					continue;
3326 				session_template_clone(xp, NULL, xp->conf.id,
3327 				    xp->conf.remote_as);
3328 				if (imsg_rde(IMSG_SESSION_ADD, xp->conf.id,
3329 				    &xp->conf, sizeof(xp->conf)) == -1)
3330 					fatalx("imsg_compose error");
3331 			}
3332 		}
3333 	}
3334 
3335 	/* pfkeys of new peers already loaded by the parent process */
3336 	RB_FOREACH_SAFE(np, peer_head, &nc->peers, next) {
3337 		RB_REMOVE(peer_head, &nc->peers, np);
3338 		if (RB_INSERT(peer_head, &c->peers, np) != NULL)
3339 			fatalx("%s: peer tree is corrupt", __func__);
3340 		if (np->conf.auth.method == AUTH_MD5SIG)
3341 			tcp_md5_add_listener(c, np);
3342 	}
3343 }
3344