xref: /openbsd-src/usr.sbin/bgpd/session.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*	$OpenBSD: session.c,v 1.399 2020/02/12 10:33:56 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 struct bgpd_config	*conf, *nconf;
104 struct bgpd_sysdep	 sysdep;
105 volatile sig_atomic_t	 session_quit;
106 int			 pending_reconf;
107 int			 csock = -1, rcsock = -1;
108 u_int			 peer_cnt;
109 struct imsgbuf		*ibuf_rde;
110 struct imsgbuf		*ibuf_rde_ctl;
111 struct imsgbuf		*ibuf_main;
112 
113 struct mrt_head		 mrthead;
114 time_t			 pauseaccept;
115 
116 static inline int
117 peer_compare(const struct peer *a, const struct peer *b)
118 {
119 	return a->conf.id - b->conf.id;
120 }
121 
122 RB_GENERATE(peer_head, peer, entry, peer_compare);
123 
124 void
125 session_sighdlr(int sig)
126 {
127 	switch (sig) {
128 	case SIGINT:
129 	case SIGTERM:
130 		session_quit = 1;
131 		break;
132 	}
133 }
134 
135 int
136 setup_listeners(u_int *la_cnt)
137 {
138 	int			 ttl = 255;
139 	struct listen_addr	*la;
140 	u_int			 cnt = 0;
141 
142 	TAILQ_FOREACH(la, conf->listen_addrs, entry) {
143 		la->reconf = RECONF_NONE;
144 		cnt++;
145 
146 		if (la->flags & LISTENER_LISTENING)
147 			continue;
148 
149 		if (la->fd == -1) {
150 			log_warn("cannot establish listener on %s: invalid fd",
151 			    log_sockaddr((struct sockaddr *)&la->sa,
152 			    la->sa_len));
153 			continue;
154 		}
155 
156 		if (tcp_md5_prep_listener(la, &conf->peers) == -1)
157 			fatal("tcp_md5_prep_listener");
158 
159 		/* set ttl to 255 so that ttl-security works */
160 		if (la->sa.ss_family == AF_INET && setsockopt(la->fd,
161 		    IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) == -1) {
162 			log_warn("setup_listeners setsockopt TTL");
163 			continue;
164 		}
165 		if (la->sa.ss_family == AF_INET6 && setsockopt(la->fd,
166 		    IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) == -1) {
167 			log_warn("setup_listeners setsockopt hoplimit");
168 			continue;
169 		}
170 
171 		if (listen(la->fd, MAX_BACKLOG)) {
172 			close(la->fd);
173 			fatal("listen");
174 		}
175 
176 		la->flags |= LISTENER_LISTENING;
177 
178 		log_info("listening on %s",
179 		    log_sockaddr((struct sockaddr *)&la->sa, la->sa_len));
180 	}
181 
182 	*la_cnt = cnt;
183 
184 	return (0);
185 }
186 
187 void
188 session_main(int debug, int verbose)
189 {
190 	int			 timeout;
191 	unsigned int		 i, j, idx_peers, idx_listeners, idx_mrts;
192 	u_int			 pfd_elms = 0, peer_l_elms = 0, mrt_l_elms = 0;
193 	u_int			 listener_cnt, ctl_cnt, mrt_cnt;
194 	u_int			 new_cnt;
195 	struct passwd		*pw;
196 	struct peer		*p, **peer_l = NULL, *next;
197 	struct mrt		*m, *xm, **mrt_l = NULL;
198 	struct pollfd		*pfd = NULL;
199 	struct ctl_conn		*ctl_conn;
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 	bgpd_process = PROC_SE;
209 	log_procinit(log_procnames[bgpd_process]);
210 
211 	if ((pw = getpwnam(BGPD_USER)) == NULL)
212 		fatal(NULL);
213 
214 	if (chroot(pw->pw_dir) == -1)
215 		fatal("chroot");
216 	if (chdir("/") == -1)
217 		fatal("chdir(\"/\")");
218 
219 	setproctitle("session engine");
220 
221 	if (setgroups(1, &pw->pw_gid) ||
222 	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
223 	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
224 		fatal("can't drop privileges");
225 
226 	if (pledge("stdio inet recvfd", NULL) == -1)
227 		fatal("pledge");
228 
229 	signal(SIGTERM, session_sighdlr);
230 	signal(SIGINT, session_sighdlr);
231 	signal(SIGPIPE, SIG_IGN);
232 	signal(SIGHUP, SIG_IGN);
233 	signal(SIGALRM, SIG_IGN);
234 	signal(SIGUSR1, SIG_IGN);
235 
236 	if ((ibuf_main = malloc(sizeof(struct imsgbuf))) == NULL)
237 		fatal(NULL);
238 	imsg_init(ibuf_main, 3);
239 
240 	TAILQ_INIT(&ctl_conns);
241 	LIST_INIT(&mrthead);
242 	listener_cnt = 0;
243 	peer_cnt = 0;
244 	ctl_cnt = 0;
245 
246 	conf = new_config();
247 	log_info("session engine ready");
248 
249 	while (session_quit == 0) {
250 		/* check for peers to be initialized or deleted */
251 		if (!pending_reconf) {
252 			RB_FOREACH_SAFE(p, peer_head, &conf->peers, next) {
253 				/* cloned peer that idled out? */
254 				if (p->template && (p->state == STATE_IDLE ||
255 				    p->state == STATE_ACTIVE) &&
256 				    getmonotime() - p->stats.last_updown >=
257 				    INTERVAL_HOLD_CLONED)
258 					p->reconf_action = RECONF_DELETE;
259 
260 				/* new peer that needs init? */
261 				if (p->state == STATE_NONE)
262 					init_peer(p);
263 
264 				/* reinit due? */
265 				if (p->reconf_action == RECONF_REINIT) {
266 					session_stop(p, ERR_CEASE_ADMIN_RESET);
267 					if (!p->conf.down)
268 						timer_set(p, Timer_IdleHold, 0);
269 				}
270 
271 				/* deletion due? */
272 				if (p->reconf_action == RECONF_DELETE) {
273 					if (p->demoted)
274 						session_demote(p, -1);
275 					p->conf.demote_group[0] = 0;
276 					session_stop(p, ERR_CEASE_PEER_UNCONF);
277 					timer_remove_all(p);
278 					tcp_md5_del_listener(conf, p);
279 					log_peer_warnx(&p->conf, "removed");
280 					RB_REMOVE(peer_head, &conf->peers, p);
281 					free(p);
282 					peer_cnt--;
283 					continue;
284 				}
285 				p->reconf_action = RECONF_NONE;
286 			}
287 		}
288 
289 		if (peer_cnt > peer_l_elms) {
290 			if ((newp = reallocarray(peer_l, peer_cnt,
291 			    sizeof(struct peer *))) == NULL) {
292 				/* panic for now  */
293 				log_warn("could not resize peer_l from %u -> %u"
294 				    " entries", peer_l_elms, peer_cnt);
295 				fatalx("exiting");
296 			}
297 			peer_l = newp;
298 			peer_l_elms = peer_cnt;
299 		}
300 
301 		mrt_cnt = 0;
302 		for (m = LIST_FIRST(&mrthead); m != NULL; m = xm) {
303 			xm = LIST_NEXT(m, entry);
304 			if (m->state == MRT_STATE_REMOVE) {
305 				mrt_clean(m);
306 				LIST_REMOVE(m, entry);
307 				free(m);
308 				continue;
309 			}
310 			if (m->wbuf.queued)
311 				mrt_cnt++;
312 		}
313 
314 		if (mrt_cnt > mrt_l_elms) {
315 			if ((newp = reallocarray(mrt_l, mrt_cnt,
316 			    sizeof(struct mrt *))) == NULL) {
317 				/* panic for now  */
318 				log_warn("could not resize mrt_l from %u -> %u"
319 				    " entries", mrt_l_elms, mrt_cnt);
320 				fatalx("exiting");
321 			}
322 			mrt_l = newp;
323 			mrt_l_elms = mrt_cnt;
324 		}
325 
326 		new_cnt = PFD_LISTENERS_START + listener_cnt + peer_cnt +
327 		    ctl_cnt + mrt_cnt;
328 		if (new_cnt > pfd_elms) {
329 			if ((newp = reallocarray(pfd, new_cnt,
330 			    sizeof(struct pollfd))) == NULL) {
331 				/* panic for now  */
332 				log_warn("could not resize pfd from %u -> %u"
333 				    " entries", pfd_elms, new_cnt);
334 				fatalx("exiting");
335 			}
336 			pfd = newp;
337 			pfd_elms = new_cnt;
338 		}
339 
340 		bzero(pfd, sizeof(struct pollfd) * pfd_elms);
341 
342 		set_pollfd(&pfd[PFD_PIPE_MAIN], ibuf_main);
343 		set_pollfd(&pfd[PFD_PIPE_ROUTE], ibuf_rde);
344 		set_pollfd(&pfd[PFD_PIPE_ROUTE_CTL], ibuf_rde_ctl);
345 
346 		if (pauseaccept == 0) {
347 			pfd[PFD_SOCK_CTL].fd = csock;
348 			pfd[PFD_SOCK_CTL].events = POLLIN;
349 			pfd[PFD_SOCK_RCTL].fd = rcsock;
350 			pfd[PFD_SOCK_RCTL].events = POLLIN;
351 		} else {
352 			pfd[PFD_SOCK_CTL].fd = -1;
353 			pfd[PFD_SOCK_RCTL].fd = -1;
354 		}
355 
356 		i = PFD_LISTENERS_START;
357 		TAILQ_FOREACH(la, conf->listen_addrs, entry) {
358 			if (pauseaccept == 0) {
359 				pfd[i].fd = la->fd;
360 				pfd[i].events = POLLIN;
361 			} else
362 				pfd[i].fd = -1;
363 			i++;
364 		}
365 		idx_listeners = i;
366 		timeout = 240;	/* loop every 240s at least */
367 
368 		now = getmonotime();
369 		RB_FOREACH(p, peer_head, &conf->peers) {
370 			time_t	nextaction;
371 			struct peer_timer *pt;
372 
373 			/* check timers */
374 			if ((pt = timer_nextisdue(p, now)) != NULL) {
375 				switch (pt->type) {
376 				case Timer_Hold:
377 					bgp_fsm(p, EVNT_TIMER_HOLDTIME);
378 					break;
379 				case Timer_ConnectRetry:
380 					bgp_fsm(p, EVNT_TIMER_CONNRETRY);
381 					break;
382 				case Timer_Keepalive:
383 					bgp_fsm(p, EVNT_TIMER_KEEPALIVE);
384 					break;
385 				case Timer_IdleHold:
386 					bgp_fsm(p, EVNT_START);
387 					break;
388 				case Timer_IdleHoldReset:
389 					p->IdleHoldTime =
390 					    INTERVAL_IDLE_HOLD_INITIAL;
391 					p->errcnt = 0;
392 					timer_stop(p, Timer_IdleHoldReset);
393 					break;
394 				case Timer_CarpUndemote:
395 					timer_stop(p, Timer_CarpUndemote);
396 					if (p->demoted &&
397 					    p->state == STATE_ESTABLISHED)
398 						session_demote(p, -1);
399 					break;
400 				case Timer_RestartTimeout:
401 					timer_stop(p, Timer_RestartTimeout);
402 					session_graceful_stop(p);
403 					break;
404 				default:
405 					fatalx("King Bula lost in time");
406 				}
407 			}
408 			if ((nextaction = timer_nextduein(p, now)) != -1 &&
409 			    nextaction < timeout)
410 				timeout = nextaction;
411 
412 			/* are we waiting for a write? */
413 			events = POLLIN;
414 			if (p->wbuf.queued > 0 || p->state == STATE_CONNECT)
415 				events |= POLLOUT;
416 			/* is there still work to do? */
417 			if (p->rpending && p->rbuf && p->rbuf->wpos)
418 				timeout = 0;
419 
420 			/* poll events */
421 			if (p->fd != -1 && events != 0) {
422 				pfd[i].fd = p->fd;
423 				pfd[i].events = events;
424 				peer_l[i - idx_listeners] = p;
425 				i++;
426 			}
427 		}
428 
429 		idx_peers = i;
430 
431 		LIST_FOREACH(m, &mrthead, entry)
432 			if (m->wbuf.queued) {
433 				pfd[i].fd = m->wbuf.fd;
434 				pfd[i].events = POLLOUT;
435 				mrt_l[i - idx_peers] = m;
436 				i++;
437 			}
438 
439 		idx_mrts = i;
440 
441 		TAILQ_FOREACH(ctl_conn, &ctl_conns, entry) {
442 			pfd[i].fd = ctl_conn->ibuf.fd;
443 			pfd[i].events = POLLIN;
444 			if (ctl_conn->ibuf.w.queued > 0)
445 				pfd[i].events |= POLLOUT;
446 			i++;
447 		}
448 
449 		if (pauseaccept && timeout > 1)
450 			timeout = 1;
451 		if (timeout < 0)
452 			timeout = 0;
453 		if (poll(pfd, i, timeout * 1000) == -1)
454 			if (errno != EINTR)
455 				fatal("poll error");
456 
457 		/*
458 		 * If we previously saw fd exhaustion, we stop accept()
459 		 * for 1 second to throttle the accept() loop.
460 		 */
461 		if (pauseaccept && getmonotime() > pauseaccept + 1)
462 			pauseaccept = 0;
463 
464 		if (handle_pollfd(&pfd[PFD_PIPE_MAIN], ibuf_main) == -1) {
465 			log_warnx("SE: Lost connection to parent");
466 			session_quit = 1;
467 			continue;
468 		} else
469 			session_dispatch_imsg(ibuf_main, PFD_PIPE_MAIN,
470 			    &listener_cnt);
471 
472 		if (handle_pollfd(&pfd[PFD_PIPE_ROUTE], ibuf_rde) == -1) {
473 			log_warnx("SE: Lost connection to RDE");
474 			msgbuf_clear(&ibuf_rde->w);
475 			free(ibuf_rde);
476 			ibuf_rde = NULL;
477 		} else
478 			session_dispatch_imsg(ibuf_rde, PFD_PIPE_ROUTE,
479 			    &listener_cnt);
480 
481 		if (handle_pollfd(&pfd[PFD_PIPE_ROUTE_CTL], ibuf_rde_ctl) ==
482 		    -1) {
483 			log_warnx("SE: Lost connection to RDE control");
484 			msgbuf_clear(&ibuf_rde_ctl->w);
485 			free(ibuf_rde_ctl);
486 			ibuf_rde_ctl = NULL;
487 		} else
488 			session_dispatch_imsg(ibuf_rde_ctl, PFD_PIPE_ROUTE_CTL,
489 			    &listener_cnt);
490 
491 		if (pfd[PFD_SOCK_CTL].revents & POLLIN)
492 			ctl_cnt += control_accept(csock, 0);
493 
494 		if (pfd[PFD_SOCK_RCTL].revents & POLLIN)
495 			ctl_cnt += control_accept(rcsock, 1);
496 
497 		for (j = PFD_LISTENERS_START; j < idx_listeners; j++)
498 			if (pfd[j].revents & POLLIN)
499 				session_accept(pfd[j].fd);
500 
501 		for (; j < idx_peers; j++)
502 			session_dispatch_msg(&pfd[j],
503 			    peer_l[j - idx_listeners]);
504 
505 		RB_FOREACH(p, peer_head, &conf->peers)
506 			if (p->rbuf && p->rbuf->wpos)
507 				session_process_msg(p);
508 
509 		for (; j < idx_mrts; j++)
510 			if (pfd[j].revents & POLLOUT)
511 				mrt_write(mrt_l[j - idx_peers]);
512 
513 		for (; j < i; j++)
514 			control_dispatch_msg(&pfd[j], &ctl_cnt, &conf->peers);
515 	}
516 
517 	RB_FOREACH_SAFE(p, peer_head, &conf->peers, next) {
518 		RB_REMOVE(peer_head, &conf->peers, p);
519 		strlcpy(p->conf.shutcomm,
520 		    "bgpd shutting down",
521 		    sizeof(p->conf.shutcomm));
522 		session_stop(p, ERR_CEASE_ADMIN_DOWN);
523 		timer_remove_all(p);
524 		free(p);
525 	}
526 
527 	while ((m = LIST_FIRST(&mrthead)) != NULL) {
528 		mrt_clean(m);
529 		LIST_REMOVE(m, entry);
530 		free(m);
531 	}
532 
533 	free_config(conf);
534 	free(peer_l);
535 	free(mrt_l);
536 	free(pfd);
537 
538 	/* close pipes */
539 	if (ibuf_rde) {
540 		msgbuf_write(&ibuf_rde->w);
541 		msgbuf_clear(&ibuf_rde->w);
542 		close(ibuf_rde->fd);
543 		free(ibuf_rde);
544 	}
545 	if (ibuf_rde_ctl) {
546 		msgbuf_clear(&ibuf_rde_ctl->w);
547 		close(ibuf_rde_ctl->fd);
548 		free(ibuf_rde_ctl);
549 	}
550 	msgbuf_write(&ibuf_main->w);
551 	msgbuf_clear(&ibuf_main->w);
552 	close(ibuf_main->fd);
553 	free(ibuf_main);
554 
555 	control_shutdown(csock);
556 	control_shutdown(rcsock);
557 	log_info("session engine exiting");
558 	exit(0);
559 }
560 
561 void
562 init_peer(struct peer *p)
563 {
564 	TAILQ_INIT(&p->timers);
565 	p->fd = p->wbuf.fd = -1;
566 
567 	if (p->conf.if_depend[0])
568 		imsg_compose(ibuf_main, IMSG_IFINFO, 0, 0, -1,
569 		    p->conf.if_depend, sizeof(p->conf.if_depend));
570 	else
571 		p->depend_ok = 1;
572 
573 	peer_cnt++;
574 
575 	change_state(p, STATE_IDLE, EVNT_NONE);
576 	if (p->conf.down)
577 		timer_stop(p, Timer_IdleHold);		/* no autostart */
578 	else
579 		timer_set(p, Timer_IdleHold, 0);	/* start ASAP */
580 
581 	/*
582 	 * on startup, demote if requested.
583 	 * do not handle new peers. they must reach ESTABLISHED beforehands.
584 	 * peers added at runtime have reconf_action set to RECONF_REINIT.
585 	 */
586 	if (p->reconf_action != RECONF_REINIT && p->conf.demote_group[0])
587 		session_demote(p, +1);
588 }
589 
590 void
591 bgp_fsm(struct peer *peer, enum session_events event)
592 {
593 	switch (peer->state) {
594 	case STATE_NONE:
595 		/* nothing */
596 		break;
597 	case STATE_IDLE:
598 		switch (event) {
599 		case EVNT_START:
600 			timer_stop(peer, Timer_Hold);
601 			timer_stop(peer, Timer_Keepalive);
602 			timer_stop(peer, Timer_IdleHold);
603 
604 			/* allocate read buffer */
605 			peer->rbuf = calloc(1, sizeof(struct ibuf_read));
606 			if (peer->rbuf == NULL)
607 				fatal(NULL);
608 
609 			/* init write buffer */
610 			msgbuf_init(&peer->wbuf);
611 
612 			peer->stats.last_sent_errcode = 0;
613 			peer->stats.last_sent_suberr = 0;
614 			peer->stats.last_rcvd_errcode = 0;
615 			peer->stats.last_rcvd_suberr = 0;
616 
617 			if (!peer->depend_ok)
618 				timer_stop(peer, Timer_ConnectRetry);
619 			else if (peer->passive || peer->conf.passive ||
620 			    peer->conf.template) {
621 				change_state(peer, STATE_ACTIVE, event);
622 				timer_stop(peer, Timer_ConnectRetry);
623 			} else {
624 				change_state(peer, STATE_CONNECT, event);
625 				timer_set(peer, Timer_ConnectRetry,
626 				    conf->connectretry);
627 				session_connect(peer);
628 			}
629 			peer->passive = 0;
630 			break;
631 		default:
632 			/* ignore */
633 			break;
634 		}
635 		break;
636 	case STATE_CONNECT:
637 		switch (event) {
638 		case EVNT_START:
639 			/* ignore */
640 			break;
641 		case EVNT_CON_OPEN:
642 			session_tcp_established(peer);
643 			session_open(peer);
644 			timer_stop(peer, Timer_ConnectRetry);
645 			peer->holdtime = INTERVAL_HOLD_INITIAL;
646 			start_timer_holdtime(peer);
647 			change_state(peer, STATE_OPENSENT, event);
648 			break;
649 		case EVNT_CON_OPENFAIL:
650 			timer_set(peer, Timer_ConnectRetry,
651 			    conf->connectretry);
652 			session_close_connection(peer);
653 			change_state(peer, STATE_ACTIVE, event);
654 			break;
655 		case EVNT_TIMER_CONNRETRY:
656 			timer_set(peer, Timer_ConnectRetry,
657 			    conf->connectretry);
658 			session_connect(peer);
659 			break;
660 		default:
661 			change_state(peer, STATE_IDLE, event);
662 			break;
663 		}
664 		break;
665 	case STATE_ACTIVE:
666 		switch (event) {
667 		case EVNT_START:
668 			/* ignore */
669 			break;
670 		case EVNT_CON_OPEN:
671 			session_tcp_established(peer);
672 			session_open(peer);
673 			timer_stop(peer, Timer_ConnectRetry);
674 			peer->holdtime = INTERVAL_HOLD_INITIAL;
675 			start_timer_holdtime(peer);
676 			change_state(peer, STATE_OPENSENT, event);
677 			break;
678 		case EVNT_CON_OPENFAIL:
679 			timer_set(peer, Timer_ConnectRetry,
680 			    conf->connectretry);
681 			session_close_connection(peer);
682 			change_state(peer, STATE_ACTIVE, event);
683 			break;
684 		case EVNT_TIMER_CONNRETRY:
685 			timer_set(peer, Timer_ConnectRetry,
686 			    peer->holdtime);
687 			change_state(peer, STATE_CONNECT, event);
688 			session_connect(peer);
689 			break;
690 		default:
691 			change_state(peer, STATE_IDLE, event);
692 			break;
693 		}
694 		break;
695 	case STATE_OPENSENT:
696 		switch (event) {
697 		case EVNT_START:
698 			/* ignore */
699 			break;
700 		case EVNT_STOP:
701 			change_state(peer, STATE_IDLE, event);
702 			break;
703 		case EVNT_CON_CLOSED:
704 			session_close_connection(peer);
705 			timer_set(peer, Timer_ConnectRetry,
706 			    conf->connectretry);
707 			change_state(peer, STATE_ACTIVE, event);
708 			break;
709 		case EVNT_CON_FATAL:
710 			change_state(peer, STATE_IDLE, event);
711 			break;
712 		case EVNT_TIMER_HOLDTIME:
713 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
714 			    0, NULL, 0);
715 			change_state(peer, STATE_IDLE, event);
716 			break;
717 		case EVNT_RCVD_OPEN:
718 			/* parse_open calls change_state itself on failure */
719 			if (parse_open(peer))
720 				break;
721 			session_keepalive(peer);
722 			change_state(peer, STATE_OPENCONFIRM, event);
723 			break;
724 		case EVNT_RCVD_NOTIFICATION:
725 			if (parse_notification(peer)) {
726 				change_state(peer, STATE_IDLE, event);
727 				/* don't punish, capa negotiation */
728 				timer_set(peer, Timer_IdleHold, 0);
729 				peer->IdleHoldTime /= 2;
730 			} else
731 				change_state(peer, STATE_IDLE, event);
732 			break;
733 		default:
734 			session_notification(peer,
735 			    ERR_FSM, ERR_FSM_UNEX_OPENSENT, NULL, 0);
736 			change_state(peer, STATE_IDLE, event);
737 			break;
738 		}
739 		break;
740 	case STATE_OPENCONFIRM:
741 		switch (event) {
742 		case EVNT_START:
743 			/* ignore */
744 			break;
745 		case EVNT_STOP:
746 			change_state(peer, STATE_IDLE, event);
747 			break;
748 		case EVNT_CON_CLOSED:
749 		case EVNT_CON_FATAL:
750 			change_state(peer, STATE_IDLE, event);
751 			break;
752 		case EVNT_TIMER_HOLDTIME:
753 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
754 			    0, NULL, 0);
755 			change_state(peer, STATE_IDLE, event);
756 			break;
757 		case EVNT_TIMER_KEEPALIVE:
758 			session_keepalive(peer);
759 			break;
760 		case EVNT_RCVD_KEEPALIVE:
761 			start_timer_holdtime(peer);
762 			change_state(peer, STATE_ESTABLISHED, event);
763 			break;
764 		case EVNT_RCVD_NOTIFICATION:
765 			parse_notification(peer);
766 			change_state(peer, STATE_IDLE, event);
767 			break;
768 		default:
769 			session_notification(peer,
770 			    ERR_FSM, ERR_FSM_UNEX_OPENCONFIRM, NULL, 0);
771 			change_state(peer, STATE_IDLE, event);
772 			break;
773 		}
774 		break;
775 	case STATE_ESTABLISHED:
776 		switch (event) {
777 		case EVNT_START:
778 			/* ignore */
779 			break;
780 		case EVNT_STOP:
781 			change_state(peer, STATE_IDLE, event);
782 			break;
783 		case EVNT_CON_CLOSED:
784 		case EVNT_CON_FATAL:
785 			change_state(peer, STATE_IDLE, event);
786 			break;
787 		case EVNT_TIMER_HOLDTIME:
788 			session_notification(peer, ERR_HOLDTIMEREXPIRED,
789 			    0, NULL, 0);
790 			change_state(peer, STATE_IDLE, event);
791 			break;
792 		case EVNT_TIMER_KEEPALIVE:
793 			session_keepalive(peer);
794 			break;
795 		case EVNT_RCVD_KEEPALIVE:
796 			start_timer_holdtime(peer);
797 			break;
798 		case EVNT_RCVD_UPDATE:
799 			start_timer_holdtime(peer);
800 			if (parse_update(peer))
801 				change_state(peer, STATE_IDLE, event);
802 			else
803 				start_timer_holdtime(peer);
804 			break;
805 		case EVNT_RCVD_NOTIFICATION:
806 			parse_notification(peer);
807 			change_state(peer, STATE_IDLE, event);
808 			break;
809 		default:
810 			session_notification(peer,
811 			    ERR_FSM, ERR_FSM_UNEX_ESTABLISHED, NULL, 0);
812 			change_state(peer, STATE_IDLE, event);
813 			break;
814 		}
815 		break;
816 	}
817 }
818 
819 void
820 start_timer_holdtime(struct peer *peer)
821 {
822 	if (peer->holdtime > 0)
823 		timer_set(peer, Timer_Hold, peer->holdtime);
824 	else
825 		timer_stop(peer, Timer_Hold);
826 }
827 
828 void
829 start_timer_keepalive(struct peer *peer)
830 {
831 	if (peer->holdtime > 0)
832 		timer_set(peer, Timer_Keepalive, peer->holdtime / 3);
833 	else
834 		timer_stop(peer, Timer_Keepalive);
835 }
836 
837 void
838 session_close_connection(struct peer *peer)
839 {
840 	if (peer->fd != -1) {
841 		close(peer->fd);
842 		pauseaccept = 0;
843 	}
844 	peer->fd = peer->wbuf.fd = -1;
845 }
846 
847 void
848 change_state(struct peer *peer, enum session_state state,
849     enum session_events event)
850 {
851 	struct mrt	*mrt;
852 
853 	switch (state) {
854 	case STATE_IDLE:
855 		/* carp demotion first. new peers handled in init_peer */
856 		if (peer->state == STATE_ESTABLISHED &&
857 		    peer->conf.demote_group[0] && !peer->demoted)
858 			session_demote(peer, +1);
859 
860 		/*
861 		 * try to write out what's buffered (maybe a notification),
862 		 * don't bother if it fails
863 		 */
864 		if (peer->state >= STATE_OPENSENT && peer->wbuf.queued)
865 			msgbuf_write(&peer->wbuf);
866 
867 		/*
868 		 * we must start the timer for the next EVNT_START
869 		 * if we are coming here due to an error and the
870 		 * session was not established successfully before, the
871 		 * starttimerinterval needs to be exponentially increased
872 		 */
873 		if (peer->IdleHoldTime == 0)
874 			peer->IdleHoldTime = INTERVAL_IDLE_HOLD_INITIAL;
875 		peer->holdtime = INTERVAL_HOLD_INITIAL;
876 		timer_stop(peer, Timer_ConnectRetry);
877 		timer_stop(peer, Timer_Keepalive);
878 		timer_stop(peer, Timer_Hold);
879 		timer_stop(peer, Timer_IdleHold);
880 		timer_stop(peer, Timer_IdleHoldReset);
881 		session_close_connection(peer);
882 		msgbuf_clear(&peer->wbuf);
883 		free(peer->rbuf);
884 		peer->rbuf = NULL;
885 		peer->rpending = 0;
886 		bzero(&peer->capa.peer, sizeof(peer->capa.peer));
887 		if (!peer->template)
888 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
889 			    peer->conf.id, 0, -1, NULL, 0);
890 
891 		if (event != EVNT_STOP) {
892 			timer_set(peer, Timer_IdleHold, peer->IdleHoldTime);
893 			if (event != EVNT_NONE &&
894 			    peer->IdleHoldTime < MAX_IDLE_HOLD/2)
895 				peer->IdleHoldTime *= 2;
896 		}
897 		if (peer->state == STATE_ESTABLISHED) {
898 			if (peer->capa.neg.grestart.restart == 2 &&
899 			    (event == EVNT_CON_CLOSED ||
900 			    event == EVNT_CON_FATAL)) {
901 				/* don't punish graceful restart */
902 				timer_set(peer, Timer_IdleHold, 0);
903 				peer->IdleHoldTime /= 2;
904 				session_graceful_restart(peer);
905 			} else
906 				session_down(peer);
907 		}
908 		if (peer->state == STATE_NONE ||
909 		    peer->state == STATE_ESTABLISHED) {
910 			/* initialize capability negotiation structures */
911 			memcpy(&peer->capa.ann, &peer->conf.capabilities,
912 			    sizeof(peer->capa.ann));
913 			if (!peer->conf.announce_capa)
914 				session_capa_ann_none(peer);
915 		}
916 		break;
917 	case STATE_CONNECT:
918 		if (peer->state == STATE_ESTABLISHED &&
919 		    peer->capa.neg.grestart.restart == 2) {
920 			/* do the graceful restart dance */
921 			session_graceful_restart(peer);
922 			peer->holdtime = INTERVAL_HOLD_INITIAL;
923 			timer_stop(peer, Timer_ConnectRetry);
924 			timer_stop(peer, Timer_Keepalive);
925 			timer_stop(peer, Timer_Hold);
926 			timer_stop(peer, Timer_IdleHold);
927 			timer_stop(peer, Timer_IdleHoldReset);
928 			session_close_connection(peer);
929 			msgbuf_clear(&peer->wbuf);
930 			bzero(&peer->capa.peer, sizeof(peer->capa.peer));
931 		}
932 		break;
933 	case STATE_ACTIVE:
934 		if (!peer->template)
935 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
936 			    peer->conf.id, 0, -1, NULL, 0);
937 		break;
938 	case STATE_OPENSENT:
939 		break;
940 	case STATE_OPENCONFIRM:
941 		break;
942 	case STATE_ESTABLISHED:
943 		timer_set(peer, Timer_IdleHoldReset, peer->IdleHoldTime);
944 		if (peer->demoted)
945 			timer_set(peer, Timer_CarpUndemote,
946 			    INTERVAL_HOLD_DEMOTED);
947 		session_up(peer);
948 		break;
949 	default:		/* something seriously fucked */
950 		break;
951 	}
952 
953 	log_statechange(peer, state, event);
954 	LIST_FOREACH(mrt, &mrthead, entry) {
955 		if (!(mrt->type == MRT_ALL_IN || mrt->type == MRT_ALL_OUT))
956 			continue;
957 		if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
958 		    mrt->peer_id == peer->conf.id || (mrt->group_id != 0 &&
959 		    mrt->group_id == peer->conf.groupid))
960 			mrt_dump_state(mrt, peer->state, state, peer);
961 	}
962 	peer->prev_state = peer->state;
963 	peer->state = state;
964 }
965 
966 void
967 session_accept(int listenfd)
968 {
969 	int			 connfd;
970 	socklen_t		 len;
971 	struct sockaddr_storage	 cliaddr;
972 	struct peer		*p = NULL;
973 
974 	len = sizeof(cliaddr);
975 	if ((connfd = accept4(listenfd,
976 	    (struct sockaddr *)&cliaddr, &len,
977 	    SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) {
978 		if (errno == ENFILE || errno == EMFILE)
979 			pauseaccept = getmonotime();
980 		else if (errno != EWOULDBLOCK && errno != EINTR &&
981 		    errno != ECONNABORTED)
982 			log_warn("accept");
983 		return;
984 	}
985 
986 	p = getpeerbyip(conf, (struct sockaddr *)&cliaddr);
987 
988 	if (p != NULL && p->state == STATE_IDLE && p->errcnt < 2) {
989 		if (timer_running(p, Timer_IdleHold, NULL)) {
990 			/* fast reconnect after clear */
991 			p->passive = 1;
992 			bgp_fsm(p, EVNT_START);
993 		}
994 	}
995 
996 	if (p != NULL &&
997 	    (p->state == STATE_CONNECT || p->state == STATE_ACTIVE)) {
998 		if (p->fd != -1) {
999 			if (p->state == STATE_CONNECT)
1000 				session_close_connection(p);
1001 			else {
1002 				close(connfd);
1003 				return;
1004 			}
1005 		}
1006 
1007 open:
1008 		if (p->conf.auth.method != AUTH_NONE && sysdep.no_pfkey) {
1009 			log_peer_warnx(&p->conf,
1010 			    "ipsec or md5sig configured but not available");
1011 			close(connfd);
1012 			return;
1013 		}
1014 
1015 		if (tcp_md5_check(connfd, p) == -1) {
1016 			close(connfd);
1017 			return;
1018 		}
1019 		p->fd = p->wbuf.fd = connfd;
1020 		if (session_setup_socket(p)) {
1021 			close(connfd);
1022 			return;
1023 		}
1024 		bgp_fsm(p, EVNT_CON_OPEN);
1025 		return;
1026 	} else if (p != NULL && p->state == STATE_ESTABLISHED &&
1027 	    p->capa.neg.grestart.restart == 2) {
1028 		/* first do the graceful restart dance */
1029 		change_state(p, STATE_CONNECT, EVNT_CON_CLOSED);
1030 		/* then do part of the open dance */
1031 		goto open;
1032 	} else {
1033 		log_conn_attempt(p, (struct sockaddr *)&cliaddr, len);
1034 		close(connfd);
1035 	}
1036 }
1037 
1038 int
1039 session_connect(struct peer *peer)
1040 {
1041 	struct sockaddr		*sa;
1042 	socklen_t		 sa_len;
1043 
1044 	/*
1045 	 * we do not need the overcomplicated collision detection RFC 1771
1046 	 * describes; we simply make sure there is only ever one concurrent
1047 	 * tcp connection per peer.
1048 	 */
1049 	if (peer->fd != -1)
1050 		return (-1);
1051 
1052 	if ((peer->fd = socket(aid2af(peer->conf.remote_addr.aid),
1053 	    SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, IPPROTO_TCP)) == -1) {
1054 		log_peer_warn(&peer->conf, "session_connect socket");
1055 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1056 		return (-1);
1057 	}
1058 
1059 	if (peer->conf.auth.method != AUTH_NONE && sysdep.no_pfkey) {
1060 		log_peer_warnx(&peer->conf,
1061 		    "ipsec or md5sig configured but not available");
1062 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1063 		return (-1);
1064 	}
1065 
1066 	tcp_md5_set(peer->fd, peer);
1067 	peer->wbuf.fd = peer->fd;
1068 
1069 	/* if update source is set we need to bind() */
1070 	if ((sa = addr2sa(&peer->conf.local_addr, 0, &sa_len)) != NULL) {
1071 		if (bind(peer->fd, sa, sa_len) == -1) {
1072 			log_peer_warn(&peer->conf, "session_connect bind");
1073 			bgp_fsm(peer, EVNT_CON_OPENFAIL);
1074 			return (-1);
1075 		}
1076 	}
1077 
1078 	if (session_setup_socket(peer)) {
1079 		bgp_fsm(peer, EVNT_CON_OPENFAIL);
1080 		return (-1);
1081 	}
1082 
1083 	sa = addr2sa(&peer->conf.remote_addr, BGP_PORT, &sa_len);
1084 	if (connect(peer->fd, sa, sa_len) == -1) {
1085 		if (errno != EINPROGRESS) {
1086 			if (errno != peer->lasterr)
1087 				log_peer_warn(&peer->conf, "connect");
1088 			peer->lasterr = errno;
1089 			bgp_fsm(peer, EVNT_CON_OPENFAIL);
1090 			return (-1);
1091 		}
1092 	} else
1093 		bgp_fsm(peer, EVNT_CON_OPEN);
1094 
1095 	return (0);
1096 }
1097 
1098 int
1099 session_setup_socket(struct peer *p)
1100 {
1101 	int	ttl = p->conf.distance;
1102 	int	pre = IPTOS_PREC_INTERNETCONTROL;
1103 	int	nodelay = 1;
1104 	int	bsize;
1105 
1106 	switch (p->conf.remote_addr.aid) {
1107 	case AID_INET:
1108 		/* set precedence, see RFC 1771 appendix 5 */
1109 		if (setsockopt(p->fd, IPPROTO_IP, IP_TOS, &pre, sizeof(pre)) ==
1110 		    -1) {
1111 			log_peer_warn(&p->conf,
1112 			    "session_setup_socket setsockopt TOS");
1113 			return (-1);
1114 		}
1115 
1116 		if (p->conf.ebgp) {
1117 			/*
1118 			 * set TTL to foreign router's distance
1119 			 * 1=direct n=multihop with ttlsec, we always use 255
1120 			 */
1121 			if (p->conf.ttlsec) {
1122 				ttl = 256 - p->conf.distance;
1123 				if (setsockopt(p->fd, IPPROTO_IP, IP_MINTTL,
1124 				    &ttl, sizeof(ttl)) == -1) {
1125 					log_peer_warn(&p->conf,
1126 					    "session_setup_socket: "
1127 					    "setsockopt MINTTL");
1128 					return (-1);
1129 				}
1130 				ttl = 255;
1131 			}
1132 
1133 			if (setsockopt(p->fd, IPPROTO_IP, IP_TTL, &ttl,
1134 			    sizeof(ttl)) == -1) {
1135 				log_peer_warn(&p->conf,
1136 				    "session_setup_socket setsockopt TTL");
1137 				return (-1);
1138 			}
1139 		}
1140 		break;
1141 	case AID_INET6:
1142 		if (p->conf.ebgp) {
1143 			/*
1144 			 * set hoplimit to foreign router's distance
1145 			 * 1=direct n=multihop with ttlsec, we always use 255
1146 			 */
1147 			if (p->conf.ttlsec) {
1148 				ttl = 256 - p->conf.distance;
1149 				if (setsockopt(p->fd, IPPROTO_IPV6,
1150 				    IPV6_MINHOPCOUNT, &ttl, sizeof(ttl))
1151 				    == -1) {
1152 					log_peer_warn(&p->conf,
1153 					    "session_setup_socket: "
1154 					    "setsockopt MINHOPCOUNT");
1155 					return (-1);
1156 				}
1157 				ttl = 255;
1158 			}
1159 			if (setsockopt(p->fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
1160 			    &ttl, sizeof(ttl)) == -1) {
1161 				log_peer_warn(&p->conf,
1162 				    "session_setup_socket setsockopt hoplimit");
1163 				return (-1);
1164 			}
1165 		}
1166 		break;
1167 	}
1168 
1169 	/* set TCP_NODELAY */
1170 	if (setsockopt(p->fd, IPPROTO_TCP, TCP_NODELAY, &nodelay,
1171 	    sizeof(nodelay)) == -1) {
1172 		log_peer_warn(&p->conf,
1173 		    "session_setup_socket setsockopt TCP_NODELAY");
1174 		return (-1);
1175 	}
1176 
1177 	/* only increase bufsize (and thus window) if md5 or ipsec is in use */
1178 	if (p->conf.auth.method != AUTH_NONE) {
1179 		/* try to increase bufsize. no biggie if it fails */
1180 		bsize = 65535;
1181 		while (bsize > 8192 &&
1182 		    setsockopt(p->fd, SOL_SOCKET, SO_RCVBUF, &bsize,
1183 		    sizeof(bsize)) == -1 && errno != EINVAL)
1184 			bsize /= 2;
1185 		bsize = 65535;
1186 		while (bsize > 8192 &&
1187 		    setsockopt(p->fd, SOL_SOCKET, SO_SNDBUF, &bsize,
1188 		    sizeof(bsize)) == -1 && errno != EINVAL)
1189 			bsize /= 2;
1190 	}
1191 
1192 	return (0);
1193 }
1194 
1195 /* compare two sockaddrs by converting them into bgpd_addr */
1196 static int
1197 sa_cmp(struct sockaddr *a, struct sockaddr *b)
1198 {
1199 	struct bgpd_addr ba, bb;
1200 
1201 	sa2addr(a, &ba, NULL);
1202 	sa2addr(b, &bb, NULL);
1203 
1204 	return (memcmp(&ba, &bb, sizeof(ba)) == 0);
1205 }
1206 
1207 static void
1208 get_alternate_addr(struct sockaddr *sa, struct bgpd_addr *alt)
1209 {
1210 	struct ifaddrs	*ifap, *ifa, *match;
1211 
1212 	if (getifaddrs(&ifap) == -1)
1213 		fatal("getifaddrs");
1214 
1215 	for (match = ifap; match != NULL; match = match->ifa_next)
1216 		if (sa_cmp(sa, match->ifa_addr) == 0)
1217 			break;
1218 
1219 	if (match == NULL) {
1220 		log_warnx("%s: local address not found", __func__);
1221 		return;
1222 	}
1223 
1224 	switch (sa->sa_family) {
1225 	case AF_INET6:
1226 		for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
1227 			if (ifa->ifa_addr->sa_family == AF_INET &&
1228 			    strcmp(ifa->ifa_name, match->ifa_name) == 0) {
1229 				sa2addr(ifa->ifa_addr, alt, NULL);
1230 				break;
1231 			}
1232 		}
1233 		break;
1234 	case AF_INET:
1235 		for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
1236 			struct sockaddr_in6 *s =
1237 			    (struct sockaddr_in6 *)ifa->ifa_addr;
1238 			if (ifa->ifa_addr->sa_family == AF_INET6 &&
1239 			    strcmp(ifa->ifa_name, match->ifa_name) == 0) {
1240 				/* only accept global scope addresses */
1241 				if (IN6_IS_ADDR_LINKLOCAL(&s->sin6_addr) ||
1242 				    IN6_IS_ADDR_SITELOCAL(&s->sin6_addr))
1243 					continue;
1244 				sa2addr(ifa->ifa_addr, alt, NULL);
1245 				break;
1246 			}
1247 		}
1248 		break;
1249 	default:
1250 		log_warnx("%s: unsupported address family %d", __func__,
1251 		    sa->sa_family);
1252 		break;
1253 	}
1254 
1255 	freeifaddrs(ifap);
1256 }
1257 
1258 void
1259 session_tcp_established(struct peer *peer)
1260 {
1261 	struct sockaddr_storage	ss;
1262 	socklen_t		len;
1263 
1264 	len = sizeof(ss);
1265 	if (getsockname(peer->fd, (struct sockaddr *)&ss, &len) == -1)
1266 		log_warn("getsockname");
1267 	sa2addr((struct sockaddr *)&ss, &peer->local, &peer->local_port);
1268 	get_alternate_addr((struct sockaddr *)&ss, &peer->local_alt);
1269 	len = sizeof(ss);
1270 	if (getpeername(peer->fd, (struct sockaddr *)&ss, &len) == -1)
1271 		log_warn("getpeername");
1272 	sa2addr((struct sockaddr *)&ss, &peer->remote, &peer->remote_port);
1273 }
1274 
1275 void
1276 session_capa_ann_none(struct peer *peer)
1277 {
1278 	bzero(&peer->capa.ann, sizeof(peer->capa.ann));
1279 }
1280 
1281 int
1282 session_capa_add(struct ibuf *opb, u_int8_t capa_code, u_int8_t capa_len)
1283 {
1284 	int errs = 0;
1285 
1286 	errs += ibuf_add(opb, &capa_code, sizeof(capa_code));
1287 	errs += ibuf_add(opb, &capa_len, sizeof(capa_len));
1288 	return (errs);
1289 }
1290 
1291 int
1292 session_capa_add_mp(struct ibuf *buf, u_int8_t aid)
1293 {
1294 	u_int8_t		 safi, pad = 0;
1295 	u_int16_t		 afi;
1296 	int			 errs = 0;
1297 
1298 	if (aid2afi(aid, &afi, &safi) == -1)
1299 		fatalx("session_capa_add_mp: bad afi/safi pair");
1300 	afi = htons(afi);
1301 	errs += ibuf_add(buf, &afi, sizeof(afi));
1302 	errs += ibuf_add(buf, &pad, sizeof(pad));
1303 	errs += ibuf_add(buf, &safi, sizeof(safi));
1304 
1305 	return (errs);
1306 }
1307 
1308 int
1309 session_capa_add_gr(struct peer *p, struct ibuf *b, u_int8_t aid)
1310 {
1311 	u_int		errs = 0;
1312 	u_int16_t	afi;
1313 	u_int8_t	flags, safi;
1314 
1315 	if (aid2afi(aid, &afi, &safi)) {
1316 		log_warn("session_capa_add_gr: bad AID");
1317 		return (1);
1318 	}
1319 	if (p->capa.neg.grestart.flags[aid] & CAPA_GR_RESTARTING)
1320 		flags = CAPA_GR_F_FLAG;
1321 	else
1322 		flags = 0;
1323 
1324 	afi = htons(afi);
1325 	errs += ibuf_add(b, &afi, sizeof(afi));
1326 	errs += ibuf_add(b, &safi, sizeof(safi));
1327 	errs += ibuf_add(b, &flags, sizeof(flags));
1328 
1329 	return (errs);
1330 }
1331 
1332 struct bgp_msg *
1333 session_newmsg(enum msg_type msgtype, u_int16_t len)
1334 {
1335 	struct bgp_msg		*msg;
1336 	struct msg_header	 hdr;
1337 	struct ibuf		*buf;
1338 	int			 errs = 0;
1339 
1340 	memset(&hdr.marker, 0xff, sizeof(hdr.marker));
1341 	hdr.len = htons(len);
1342 	hdr.type = msgtype;
1343 
1344 	if ((buf = ibuf_open(len)) == NULL)
1345 		return (NULL);
1346 
1347 	errs += ibuf_add(buf, &hdr.marker, sizeof(hdr.marker));
1348 	errs += ibuf_add(buf, &hdr.len, sizeof(hdr.len));
1349 	errs += ibuf_add(buf, &hdr.type, sizeof(hdr.type));
1350 
1351 	if (errs || (msg = calloc(1, sizeof(*msg))) == NULL) {
1352 		ibuf_free(buf);
1353 		return (NULL);
1354 	}
1355 
1356 	msg->buf = buf;
1357 	msg->type = msgtype;
1358 	msg->len = len;
1359 
1360 	return (msg);
1361 }
1362 
1363 int
1364 session_sendmsg(struct bgp_msg *msg, struct peer *p)
1365 {
1366 	struct mrt		*mrt;
1367 
1368 	LIST_FOREACH(mrt, &mrthead, entry) {
1369 		if (!(mrt->type == MRT_ALL_OUT || (msg->type == UPDATE &&
1370 		    mrt->type == MRT_UPDATE_OUT)))
1371 			continue;
1372 		if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
1373 		    mrt->peer_id == p->conf.id || (mrt->group_id != 0 &&
1374 		    mrt->group_id == p->conf.groupid))
1375 			mrt_dump_bgp_msg(mrt, msg->buf->buf, msg->len, p);
1376 	}
1377 
1378 	ibuf_close(&p->wbuf, msg->buf);
1379 	if (!p->throttled && p->wbuf.queued > SESS_MSG_HIGH_MARK) {
1380 		if (imsg_rde(IMSG_XOFF, p->conf.id, NULL, 0) == -1)
1381 			log_peer_warn(&p->conf, "imsg_compose XOFF");
1382 		else
1383 			p->throttled = 1;
1384 	}
1385 
1386 	free(msg);
1387 	return (0);
1388 }
1389 
1390 void
1391 session_open(struct peer *p)
1392 {
1393 	struct bgp_msg		*buf;
1394 	struct ibuf		*opb;
1395 	struct msg_open		 msg;
1396 	u_int16_t		 len;
1397 	u_int8_t		 i, op_type, optparamlen = 0;
1398 	int			 errs = 0;
1399 	int			 mpcapa = 0;
1400 
1401 
1402 	if ((opb = ibuf_dynamic(0, UCHAR_MAX - sizeof(op_type) -
1403 	    sizeof(optparamlen))) == NULL) {
1404 		bgp_fsm(p, EVNT_CON_FATAL);
1405 		return;
1406 	}
1407 
1408 	/* multiprotocol extensions, RFC 4760 */
1409 	for (i = 0; i < AID_MAX; i++)
1410 		if (p->capa.ann.mp[i]) {	/* 4 bytes data */
1411 			errs += session_capa_add(opb, CAPA_MP, 4);
1412 			errs += session_capa_add_mp(opb, i);
1413 			mpcapa++;
1414 		}
1415 
1416 	/* route refresh, RFC 2918 */
1417 	if (p->capa.ann.refresh)	/* no data */
1418 		errs += session_capa_add(opb, CAPA_REFRESH, 0);
1419 
1420 	/* graceful restart and End-of-RIB marker, RFC 4724 */
1421 	if (p->capa.ann.grestart.restart) {
1422 		int		rst = 0;
1423 		u_int16_t	hdr;
1424 		u_int8_t	grlen;
1425 
1426 		if (mpcapa) {
1427 			grlen = 2 + 4 * mpcapa;
1428 			for (i = 0; i < AID_MAX; i++) {
1429 				if (p->capa.neg.grestart.flags[i] &
1430 				    CAPA_GR_RESTARTING)
1431 					rst++;
1432 			}
1433 		} else {	/* AID_INET */
1434 			grlen = 2 + 4;
1435 			if (p->capa.neg.grestart.flags[AID_INET] &
1436 			    CAPA_GR_RESTARTING)
1437 				rst++;
1438 		}
1439 
1440 		hdr = conf->holdtime;		/* default timeout */
1441 		/* if client does graceful restart don't set R flag */
1442 		if (!rst)
1443 			hdr |= CAPA_GR_R_FLAG;
1444 		hdr = htons(hdr);
1445 
1446 		errs += session_capa_add(opb, CAPA_RESTART, grlen);
1447 		errs += ibuf_add(opb, &hdr, sizeof(hdr));
1448 
1449 		if (mpcapa) {
1450 			for (i = 0; i < AID_MAX; i++) {
1451 				if (p->capa.ann.mp[i]) {
1452 					errs += session_capa_add_gr(p, opb, i);
1453 				}
1454 			}
1455 		} else {	/* AID_INET */
1456 			errs += session_capa_add_gr(p, opb, AID_INET);
1457 		}
1458 	}
1459 
1460 	/* 4-bytes AS numbers, draft-ietf-idr-as4bytes-13 */
1461 	if (p->capa.ann.as4byte) {	/* 4 bytes data */
1462 		u_int32_t	nas;
1463 
1464 		nas = htonl(p->conf.local_as);
1465 		errs += session_capa_add(opb, CAPA_AS4BYTE, sizeof(nas));
1466 		errs += ibuf_add(opb, &nas, sizeof(nas));
1467 	}
1468 
1469 	if (ibuf_size(opb))
1470 		optparamlen = ibuf_size(opb) + sizeof(op_type) +
1471 		    sizeof(optparamlen);
1472 
1473 	len = MSGSIZE_OPEN_MIN + optparamlen;
1474 	if (errs || (buf = session_newmsg(OPEN, len)) == NULL) {
1475 		ibuf_free(opb);
1476 		bgp_fsm(p, EVNT_CON_FATAL);
1477 		return;
1478 	}
1479 
1480 	msg.version = 4;
1481 	msg.myas = htons(p->conf.local_short_as);
1482 	if (p->conf.holdtime)
1483 		msg.holdtime = htons(p->conf.holdtime);
1484 	else
1485 		msg.holdtime = htons(conf->holdtime);
1486 	msg.bgpid = conf->bgpid;	/* is already in network byte order */
1487 	msg.optparamlen = optparamlen;
1488 
1489 	errs += ibuf_add(buf->buf, &msg.version, sizeof(msg.version));
1490 	errs += ibuf_add(buf->buf, &msg.myas, sizeof(msg.myas));
1491 	errs += ibuf_add(buf->buf, &msg.holdtime, sizeof(msg.holdtime));
1492 	errs += ibuf_add(buf->buf, &msg.bgpid, sizeof(msg.bgpid));
1493 	errs += ibuf_add(buf->buf, &msg.optparamlen, sizeof(msg.optparamlen));
1494 
1495 	if (optparamlen) {
1496 		op_type = OPT_PARAM_CAPABILITIES;
1497 		optparamlen = ibuf_size(opb);
1498 		errs += ibuf_add(buf->buf, &op_type, sizeof(op_type));
1499 		errs += ibuf_add(buf->buf, &optparamlen, sizeof(optparamlen));
1500 		errs += ibuf_add(buf->buf, opb->buf, ibuf_size(opb));
1501 	}
1502 
1503 	ibuf_free(opb);
1504 
1505 	if (errs) {
1506 		ibuf_free(buf->buf);
1507 		free(buf);
1508 		bgp_fsm(p, EVNT_CON_FATAL);
1509 		return;
1510 	}
1511 
1512 	if (session_sendmsg(buf, p) == -1) {
1513 		bgp_fsm(p, EVNT_CON_FATAL);
1514 		return;
1515 	}
1516 
1517 	p->stats.msg_sent_open++;
1518 }
1519 
1520 void
1521 session_keepalive(struct peer *p)
1522 {
1523 	struct bgp_msg		*buf;
1524 
1525 	if ((buf = session_newmsg(KEEPALIVE, MSGSIZE_KEEPALIVE)) == NULL ||
1526 	    session_sendmsg(buf, p) == -1) {
1527 		bgp_fsm(p, EVNT_CON_FATAL);
1528 		return;
1529 	}
1530 
1531 	start_timer_keepalive(p);
1532 	p->stats.msg_sent_keepalive++;
1533 }
1534 
1535 void
1536 session_update(u_int32_t peerid, void *data, size_t datalen)
1537 {
1538 	struct peer		*p;
1539 	struct bgp_msg		*buf;
1540 
1541 	if ((p = getpeerbyid(conf, peerid)) == NULL) {
1542 		log_warnx("no such peer: id=%u", peerid);
1543 		return;
1544 	}
1545 
1546 	if (p->state != STATE_ESTABLISHED)
1547 		return;
1548 
1549 	if ((buf = session_newmsg(UPDATE, MSGSIZE_HEADER + datalen)) == NULL) {
1550 		bgp_fsm(p, EVNT_CON_FATAL);
1551 		return;
1552 	}
1553 
1554 	if (ibuf_add(buf->buf, data, datalen)) {
1555 		ibuf_free(buf->buf);
1556 		free(buf);
1557 		bgp_fsm(p, EVNT_CON_FATAL);
1558 		return;
1559 	}
1560 
1561 	if (session_sendmsg(buf, p) == -1) {
1562 		bgp_fsm(p, EVNT_CON_FATAL);
1563 		return;
1564 	}
1565 
1566 	start_timer_keepalive(p);
1567 	p->stats.msg_sent_update++;
1568 }
1569 
1570 void
1571 session_notification(struct peer *p, u_int8_t errcode, u_int8_t subcode,
1572     void *data, ssize_t datalen)
1573 {
1574 	struct bgp_msg		*buf;
1575 	int			 errs = 0;
1576 
1577 	if (p->stats.last_sent_errcode)	/* some notification already sent */
1578 		return;
1579 
1580 	log_notification(p, errcode, subcode, data, datalen, "sending");
1581 
1582 	if ((buf = session_newmsg(NOTIFICATION,
1583 	    MSGSIZE_NOTIFICATION_MIN + datalen)) == NULL) {
1584 		bgp_fsm(p, EVNT_CON_FATAL);
1585 		return;
1586 	}
1587 
1588 	errs += ibuf_add(buf->buf, &errcode, sizeof(errcode));
1589 	errs += ibuf_add(buf->buf, &subcode, sizeof(subcode));
1590 
1591 	if (datalen > 0)
1592 		errs += ibuf_add(buf->buf, data, datalen);
1593 
1594 	if (errs) {
1595 		ibuf_free(buf->buf);
1596 		free(buf);
1597 		bgp_fsm(p, EVNT_CON_FATAL);
1598 		return;
1599 	}
1600 
1601 	if (session_sendmsg(buf, p) == -1) {
1602 		bgp_fsm(p, EVNT_CON_FATAL);
1603 		return;
1604 	}
1605 
1606 	p->stats.msg_sent_notification++;
1607 	p->stats.last_sent_errcode = errcode;
1608 	p->stats.last_sent_suberr = subcode;
1609 }
1610 
1611 int
1612 session_neighbor_rrefresh(struct peer *p)
1613 {
1614 	u_int8_t	i;
1615 
1616 	if (!p->capa.peer.refresh)
1617 		return (-1);
1618 
1619 	for (i = 0; i < AID_MAX; i++) {
1620 		if (p->capa.peer.mp[i] != 0)
1621 			session_rrefresh(p, i);
1622 	}
1623 
1624 	return (0);
1625 }
1626 
1627 void
1628 session_rrefresh(struct peer *p, u_int8_t aid)
1629 {
1630 	struct bgp_msg		*buf;
1631 	int			 errs = 0;
1632 	u_int16_t		 afi;
1633 	u_int8_t		 safi, null8 = 0;
1634 
1635 	if (aid2afi(aid, &afi, &safi) == -1)
1636 		fatalx("session_rrefresh: bad afi/safi pair");
1637 
1638 	if ((buf = session_newmsg(RREFRESH, MSGSIZE_RREFRESH)) == NULL) {
1639 		bgp_fsm(p, EVNT_CON_FATAL);
1640 		return;
1641 	}
1642 
1643 	afi = htons(afi);
1644 	errs += ibuf_add(buf->buf, &afi, sizeof(afi));
1645 	errs += ibuf_add(buf->buf, &null8, sizeof(null8));
1646 	errs += ibuf_add(buf->buf, &safi, sizeof(safi));
1647 
1648 	if (errs) {
1649 		ibuf_free(buf->buf);
1650 		free(buf);
1651 		bgp_fsm(p, EVNT_CON_FATAL);
1652 		return;
1653 	}
1654 
1655 	if (session_sendmsg(buf, p) == -1) {
1656 		bgp_fsm(p, EVNT_CON_FATAL);
1657 		return;
1658 	}
1659 
1660 	p->stats.msg_sent_rrefresh++;
1661 }
1662 
1663 int
1664 session_graceful_restart(struct peer *p)
1665 {
1666 	u_int8_t	i;
1667 
1668 	timer_set(p, Timer_RestartTimeout, p->capa.neg.grestart.timeout);
1669 
1670 	for (i = 0; i < AID_MAX; i++) {
1671 		if (p->capa.neg.grestart.flags[i] & CAPA_GR_PRESENT) {
1672 			if (imsg_rde(IMSG_SESSION_STALE, p->conf.id,
1673 			    &i, sizeof(i)) == -1)
1674 				return (-1);
1675 			log_peer_warnx(&p->conf,
1676 			    "graceful restart of %s, keeping routes",
1677 			    aid2str(i));
1678 			p->capa.neg.grestart.flags[i] |= CAPA_GR_RESTARTING;
1679 		} else if (p->capa.neg.mp[i]) {
1680 			if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
1681 			    &i, sizeof(i)) == -1)
1682 				return (-1);
1683 			log_peer_warnx(&p->conf,
1684 			    "graceful restart of %s, flushing routes",
1685 			    aid2str(i));
1686 		}
1687 	}
1688 	return (0);
1689 }
1690 
1691 int
1692 session_graceful_stop(struct peer *p)
1693 {
1694 	u_int8_t	i;
1695 
1696 	for (i = 0; i < AID_MAX; i++) {
1697 		/*
1698 		 * Only flush if the peer is restarting and the timeout fired.
1699 		 * In all other cases the session was already flushed when the
1700 		 * session went down or when the new open message was parsed.
1701 		 */
1702 		if (p->capa.neg.grestart.flags[i] & CAPA_GR_RESTARTING) {
1703 			log_peer_warnx(&p->conf, "graceful restart of %s, "
1704 			    "time-out, flushing", aid2str(i));
1705 			if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
1706 			    &i, sizeof(i)) == -1)
1707 				return (-1);
1708 		}
1709 		p->capa.neg.grestart.flags[i] &= ~CAPA_GR_RESTARTING;
1710 	}
1711 	return (0);
1712 }
1713 
1714 int
1715 session_dispatch_msg(struct pollfd *pfd, struct peer *p)
1716 {
1717 	ssize_t		n;
1718 	socklen_t	len;
1719 	int		error;
1720 
1721 	if (p->state == STATE_CONNECT) {
1722 		if (pfd->revents & POLLOUT) {
1723 			if (pfd->revents & POLLIN) {
1724 				/* error occurred */
1725 				len = sizeof(error);
1726 				if (getsockopt(pfd->fd, SOL_SOCKET, SO_ERROR,
1727 				    &error, &len) == -1 || error) {
1728 					if (error)
1729 						errno = error;
1730 					if (errno != p->lasterr) {
1731 						log_peer_warn(&p->conf,
1732 						    "socket error");
1733 						p->lasterr = errno;
1734 					}
1735 					bgp_fsm(p, EVNT_CON_OPENFAIL);
1736 					return (1);
1737 				}
1738 			}
1739 			bgp_fsm(p, EVNT_CON_OPEN);
1740 			return (1);
1741 		}
1742 		if (pfd->revents & POLLHUP) {
1743 			bgp_fsm(p, EVNT_CON_OPENFAIL);
1744 			return (1);
1745 		}
1746 		if (pfd->revents & (POLLERR|POLLNVAL)) {
1747 			bgp_fsm(p, EVNT_CON_FATAL);
1748 			return (1);
1749 		}
1750 		return (0);
1751 	}
1752 
1753 	if (pfd->revents & POLLHUP) {
1754 		bgp_fsm(p, EVNT_CON_CLOSED);
1755 		return (1);
1756 	}
1757 	if (pfd->revents & (POLLERR|POLLNVAL)) {
1758 		bgp_fsm(p, EVNT_CON_FATAL);
1759 		return (1);
1760 	}
1761 
1762 	if (pfd->revents & POLLOUT && p->wbuf.queued) {
1763 		if ((error = msgbuf_write(&p->wbuf)) <= 0 && errno != EAGAIN) {
1764 			if (error == 0)
1765 				log_peer_warnx(&p->conf, "Connection closed");
1766 			else if (error == -1)
1767 				log_peer_warn(&p->conf, "write error");
1768 			bgp_fsm(p, EVNT_CON_FATAL);
1769 			return (1);
1770 		}
1771 		p->stats.last_write = getmonotime();
1772 		if (p->throttled && p->wbuf.queued < SESS_MSG_LOW_MARK) {
1773 			if (imsg_rde(IMSG_XON, p->conf.id, NULL, 0) == -1)
1774 				log_peer_warn(&p->conf, "imsg_compose XON");
1775 			else
1776 				p->throttled = 0;
1777 		}
1778 		if (!(pfd->revents & POLLIN))
1779 			return (1);
1780 	}
1781 
1782 	if (p->rbuf && pfd->revents & POLLIN) {
1783 		if ((n = read(p->fd, p->rbuf->buf + p->rbuf->wpos,
1784 		    sizeof(p->rbuf->buf) - p->rbuf->wpos)) == -1) {
1785 			if (errno != EINTR && errno != EAGAIN) {
1786 				log_peer_warn(&p->conf, "read error");
1787 				bgp_fsm(p, EVNT_CON_FATAL);
1788 			}
1789 			return (1);
1790 		}
1791 		if (n == 0) {	/* connection closed */
1792 			bgp_fsm(p, EVNT_CON_CLOSED);
1793 			return (1);
1794 		}
1795 
1796 		p->rbuf->wpos += n;
1797 		p->stats.last_read = getmonotime();
1798 		return (1);
1799 	}
1800 	return (0);
1801 }
1802 
1803 void
1804 session_process_msg(struct peer *p)
1805 {
1806 	struct mrt	*mrt;
1807 	ssize_t		rpos, av, left;
1808 	int		processed = 0;
1809 	u_int16_t	msglen;
1810 	u_int8_t	msgtype;
1811 
1812 	rpos = 0;
1813 	av = p->rbuf->wpos;
1814 	p->rpending = 0;
1815 
1816 	/*
1817 	 * session might drop to IDLE -> buffers deallocated
1818 	 * we MUST check rbuf != NULL before use
1819 	 */
1820 	for (;;) {
1821 		if (p->rbuf == NULL)
1822 			return;
1823 		if (rpos + MSGSIZE_HEADER > av)
1824 			break;
1825 		if (parse_header(p, p->rbuf->buf + rpos, &msglen,
1826 		    &msgtype) == -1)
1827 			return;
1828 		if (rpos + msglen > av)
1829 			break;
1830 		p->rbuf->rptr = p->rbuf->buf + rpos;
1831 
1832 		/* dump to MRT as soon as we have a full packet */
1833 		LIST_FOREACH(mrt, &mrthead, entry) {
1834 			if (!(mrt->type == MRT_ALL_IN || (msgtype == UPDATE &&
1835 			    mrt->type == MRT_UPDATE_IN)))
1836 				continue;
1837 			if ((mrt->peer_id == 0 && mrt->group_id == 0) ||
1838 			    mrt->peer_id == p->conf.id || (mrt->group_id != 0 &&
1839 			    mrt->group_id == p->conf.groupid))
1840 				mrt_dump_bgp_msg(mrt, p->rbuf->rptr, msglen, p);
1841 		}
1842 
1843 		switch (msgtype) {
1844 		case OPEN:
1845 			bgp_fsm(p, EVNT_RCVD_OPEN);
1846 			p->stats.msg_rcvd_open++;
1847 			break;
1848 		case UPDATE:
1849 			bgp_fsm(p, EVNT_RCVD_UPDATE);
1850 			p->stats.msg_rcvd_update++;
1851 			break;
1852 		case NOTIFICATION:
1853 			bgp_fsm(p, EVNT_RCVD_NOTIFICATION);
1854 			p->stats.msg_rcvd_notification++;
1855 			break;
1856 		case KEEPALIVE:
1857 			bgp_fsm(p, EVNT_RCVD_KEEPALIVE);
1858 			p->stats.msg_rcvd_keepalive++;
1859 			break;
1860 		case RREFRESH:
1861 			parse_refresh(p);
1862 			p->stats.msg_rcvd_rrefresh++;
1863 			break;
1864 		default:	/* cannot happen */
1865 			session_notification(p, ERR_HEADER, ERR_HDR_TYPE,
1866 			    &msgtype, 1);
1867 			log_warnx("received message with unknown type %u",
1868 			    msgtype);
1869 			bgp_fsm(p, EVNT_CON_FATAL);
1870 		}
1871 		rpos += msglen;
1872 		if (++processed > MSG_PROCESS_LIMIT) {
1873 			p->rpending = 1;
1874 			break;
1875 		}
1876 	}
1877 
1878 	if (rpos < av) {
1879 		left = av - rpos;
1880 		memmove(&p->rbuf->buf, p->rbuf->buf + rpos, left);
1881 		p->rbuf->wpos = left;
1882 	} else
1883 		p->rbuf->wpos = 0;
1884 }
1885 
1886 int
1887 parse_header(struct peer *peer, u_char *data, u_int16_t *len, u_int8_t *type)
1888 {
1889 	u_char			*p;
1890 	u_int16_t		 olen;
1891 	static const u_int8_t	 marker[MSGSIZE_HEADER_MARKER] = { 0xff, 0xff,
1892 				    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
1893 				    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
1894 
1895 	/* caller MUST make sure we are getting 19 bytes! */
1896 	p = data;
1897 	if (memcmp(p, marker, sizeof(marker))) {
1898 		log_peer_warnx(&peer->conf, "sync error");
1899 		session_notification(peer, ERR_HEADER, ERR_HDR_SYNC, NULL, 0);
1900 		bgp_fsm(peer, EVNT_CON_FATAL);
1901 		return (-1);
1902 	}
1903 	p += MSGSIZE_HEADER_MARKER;
1904 
1905 	memcpy(&olen, p, 2);
1906 	*len = ntohs(olen);
1907 	p += 2;
1908 	memcpy(type, p, 1);
1909 
1910 	if (*len < MSGSIZE_HEADER || *len > MAX_PKTSIZE) {
1911 		log_peer_warnx(&peer->conf,
1912 		    "received message: illegal length: %u byte", *len);
1913 		session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1914 		    &olen, sizeof(olen));
1915 		bgp_fsm(peer, EVNT_CON_FATAL);
1916 		return (-1);
1917 	}
1918 
1919 	switch (*type) {
1920 	case OPEN:
1921 		if (*len < MSGSIZE_OPEN_MIN) {
1922 			log_peer_warnx(&peer->conf,
1923 			    "received OPEN: illegal len: %u byte", *len);
1924 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1925 			    &olen, sizeof(olen));
1926 			bgp_fsm(peer, EVNT_CON_FATAL);
1927 			return (-1);
1928 		}
1929 		break;
1930 	case NOTIFICATION:
1931 		if (*len < MSGSIZE_NOTIFICATION_MIN) {
1932 			log_peer_warnx(&peer->conf,
1933 			    "received NOTIFICATION: illegal len: %u byte",
1934 			    *len);
1935 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1936 			    &olen, sizeof(olen));
1937 			bgp_fsm(peer, EVNT_CON_FATAL);
1938 			return (-1);
1939 		}
1940 		break;
1941 	case UPDATE:
1942 		if (*len < MSGSIZE_UPDATE_MIN) {
1943 			log_peer_warnx(&peer->conf,
1944 			    "received UPDATE: illegal len: %u byte", *len);
1945 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1946 			    &olen, sizeof(olen));
1947 			bgp_fsm(peer, EVNT_CON_FATAL);
1948 			return (-1);
1949 		}
1950 		break;
1951 	case KEEPALIVE:
1952 		if (*len != MSGSIZE_KEEPALIVE) {
1953 			log_peer_warnx(&peer->conf,
1954 			    "received KEEPALIVE: illegal len: %u byte", *len);
1955 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1956 			    &olen, sizeof(olen));
1957 			bgp_fsm(peer, EVNT_CON_FATAL);
1958 			return (-1);
1959 		}
1960 		break;
1961 	case RREFRESH:
1962 		if (*len != MSGSIZE_RREFRESH) {
1963 			log_peer_warnx(&peer->conf,
1964 			    "received RREFRESH: illegal len: %u byte", *len);
1965 			session_notification(peer, ERR_HEADER, ERR_HDR_LEN,
1966 			    &olen, sizeof(olen));
1967 			bgp_fsm(peer, EVNT_CON_FATAL);
1968 			return (-1);
1969 		}
1970 		break;
1971 	default:
1972 		log_peer_warnx(&peer->conf,
1973 		    "received msg with unknown type %u", *type);
1974 		session_notification(peer, ERR_HEADER, ERR_HDR_TYPE,
1975 		    type, 1);
1976 		bgp_fsm(peer, EVNT_CON_FATAL);
1977 		return (-1);
1978 	}
1979 	return (0);
1980 }
1981 
1982 int
1983 parse_open(struct peer *peer)
1984 {
1985 	u_char		*p, *op_val;
1986 	u_int8_t	 version, rversion;
1987 	u_int16_t	 short_as, msglen;
1988 	u_int16_t	 holdtime, oholdtime, myholdtime;
1989 	u_int32_t	 as, bgpid;
1990 	u_int8_t	 optparamlen, plen;
1991 	u_int8_t	 op_type, op_len;
1992 
1993 	p = peer->rbuf->rptr;
1994 	p += MSGSIZE_HEADER_MARKER;
1995 	memcpy(&msglen, p, sizeof(msglen));
1996 	msglen = ntohs(msglen);
1997 
1998 	p = peer->rbuf->rptr;
1999 	p += MSGSIZE_HEADER;	/* header is already checked */
2000 
2001 	memcpy(&version, p, sizeof(version));
2002 	p += sizeof(version);
2003 
2004 	if (version != BGP_VERSION) {
2005 		log_peer_warnx(&peer->conf,
2006 		    "peer wants unrecognized version %u", version);
2007 		if (version > BGP_VERSION)
2008 			rversion = version - BGP_VERSION;
2009 		else
2010 			rversion = BGP_VERSION;
2011 		session_notification(peer, ERR_OPEN, ERR_OPEN_VERSION,
2012 		    &rversion, sizeof(rversion));
2013 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2014 		return (-1);
2015 	}
2016 
2017 	memcpy(&short_as, p, sizeof(short_as));
2018 	p += sizeof(short_as);
2019 	as = peer->short_as = ntohs(short_as);
2020 	if (as == 0) {
2021 		log_peer_warnx(&peer->conf,
2022 		    "peer requests unacceptable AS %u", as);
2023 		session_notification(peer, ERR_OPEN, ERR_OPEN_AS,
2024 		    NULL, 0);
2025 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2026 		return (-1);
2027 	}
2028 
2029 	memcpy(&oholdtime, p, sizeof(oholdtime));
2030 	p += sizeof(oholdtime);
2031 
2032 	holdtime = ntohs(oholdtime);
2033 	if (holdtime && holdtime < peer->conf.min_holdtime) {
2034 		log_peer_warnx(&peer->conf,
2035 		    "peer requests unacceptable holdtime %u", holdtime);
2036 		session_notification(peer, ERR_OPEN, ERR_OPEN_HOLDTIME,
2037 		    NULL, 0);
2038 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2039 		return (-1);
2040 	}
2041 
2042 	myholdtime = peer->conf.holdtime;
2043 	if (!myholdtime)
2044 		myholdtime = conf->holdtime;
2045 	if (holdtime < myholdtime)
2046 		peer->holdtime = holdtime;
2047 	else
2048 		peer->holdtime = myholdtime;
2049 
2050 	memcpy(&bgpid, p, sizeof(bgpid));
2051 	p += sizeof(bgpid);
2052 
2053 	/* check bgpid for validity - just disallow 0 */
2054 	if (ntohl(bgpid) == 0) {
2055 		log_peer_warnx(&peer->conf, "peer BGPID %u unacceptable",
2056 		    ntohl(bgpid));
2057 		session_notification(peer, ERR_OPEN, ERR_OPEN_BGPID,
2058 		    NULL, 0);
2059 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2060 		return (-1);
2061 	}
2062 	peer->remote_bgpid = bgpid;
2063 
2064 	memcpy(&optparamlen, p, sizeof(optparamlen));
2065 	p += sizeof(optparamlen);
2066 
2067 	if (optparamlen != msglen - MSGSIZE_OPEN_MIN) {
2068 			log_peer_warnx(&peer->conf,
2069 			    "corrupt OPEN message received: length mismatch");
2070 			session_notification(peer, ERR_OPEN, 0, NULL, 0);
2071 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2072 			return (-1);
2073 	}
2074 
2075 	plen = optparamlen;
2076 	while (plen > 0) {
2077 		if (plen < 2) {
2078 			log_peer_warnx(&peer->conf,
2079 			    "corrupt OPEN message received, len wrong");
2080 			session_notification(peer, ERR_OPEN, 0, NULL, 0);
2081 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2082 			return (-1);
2083 		}
2084 		memcpy(&op_type, p, sizeof(op_type));
2085 		p += sizeof(op_type);
2086 		plen -= sizeof(op_type);
2087 		memcpy(&op_len, p, sizeof(op_len));
2088 		p += sizeof(op_len);
2089 		plen -= sizeof(op_len);
2090 		if (op_len > 0) {
2091 			if (plen < op_len) {
2092 				log_peer_warnx(&peer->conf,
2093 				    "corrupt OPEN message received, len wrong");
2094 				session_notification(peer, ERR_OPEN, 0,
2095 				    NULL, 0);
2096 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2097 				return (-1);
2098 			}
2099 			op_val = p;
2100 			p += op_len;
2101 			plen -= op_len;
2102 		} else
2103 			op_val = NULL;
2104 
2105 		switch (op_type) {
2106 		case OPT_PARAM_CAPABILITIES:		/* RFC 3392 */
2107 			if (parse_capabilities(peer, op_val, op_len,
2108 			    &as) == -1) {
2109 				session_notification(peer, ERR_OPEN, 0,
2110 				    NULL, 0);
2111 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2112 				return (-1);
2113 			}
2114 			break;
2115 		case OPT_PARAM_AUTH:			/* deprecated */
2116 		default:
2117 			/*
2118 			 * unsupported type
2119 			 * the RFCs tell us to leave the data section empty
2120 			 * and notify the peer with ERR_OPEN, ERR_OPEN_OPT.
2121 			 * How the peer should know _which_ optional parameter
2122 			 * we don't support is beyond me.
2123 			 */
2124 			log_peer_warnx(&peer->conf,
2125 			    "received OPEN message with unsupported optional "
2126 			    "parameter: type %u", op_type);
2127 			session_notification(peer, ERR_OPEN, ERR_OPEN_OPT,
2128 				NULL, 0);
2129 			change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2130 			timer_set(peer, Timer_IdleHold, 0);	/* no punish */
2131 			peer->IdleHoldTime /= 2;
2132 			return (-1);
2133 		}
2134 	}
2135 
2136 	/* if remote-as is zero and it's a cloned neighbor, accept any */
2137 	if (peer->template && !peer->conf.remote_as && as != AS_TRANS) {
2138 		peer->conf.remote_as = as;
2139 		peer->conf.ebgp = (peer->conf.remote_as != peer->conf.local_as);
2140 		if (!peer->conf.ebgp)
2141 			/* force enforce_as off for iBGP sessions */
2142 			peer->conf.enforce_as = ENFORCE_AS_OFF;
2143 	}
2144 
2145 	if (peer->conf.remote_as != as) {
2146 		log_peer_warnx(&peer->conf, "peer sent wrong AS %s",
2147 		    log_as(as));
2148 		session_notification(peer, ERR_OPEN, ERR_OPEN_AS, NULL, 0);
2149 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2150 		return (-1);
2151 	}
2152 
2153 	if (capa_neg_calc(peer) == -1) {
2154 		log_peer_warnx(&peer->conf,
2155 		    "capability negotiation calculation failed");
2156 		session_notification(peer, ERR_OPEN, 0, NULL, 0);
2157 		change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2158 		return (-1);
2159 	}
2160 
2161 	return (0);
2162 }
2163 
2164 int
2165 parse_update(struct peer *peer)
2166 {
2167 	u_char		*p;
2168 	u_int16_t	 datalen;
2169 
2170 	/*
2171 	 * we pass the message verbatim to the rde.
2172 	 * in case of errors the whole session is reset with a
2173 	 * notification anyway, we only need to know the peer
2174 	 */
2175 	p = peer->rbuf->rptr;
2176 	p += MSGSIZE_HEADER_MARKER;
2177 	memcpy(&datalen, p, sizeof(datalen));
2178 	datalen = ntohs(datalen);
2179 
2180 	p = peer->rbuf->rptr;
2181 	p += MSGSIZE_HEADER;	/* header is already checked */
2182 	datalen -= MSGSIZE_HEADER;
2183 
2184 	if (imsg_rde(IMSG_UPDATE, peer->conf.id, p, datalen) == -1)
2185 		return (-1);
2186 
2187 	return (0);
2188 }
2189 
2190 int
2191 parse_refresh(struct peer *peer)
2192 {
2193 	u_char		*p;
2194 	u_int16_t	 afi;
2195 	u_int8_t	 aid, safi;
2196 
2197 	p = peer->rbuf->rptr;
2198 	p += MSGSIZE_HEADER;	/* header is already checked */
2199 
2200 	/*
2201 	 * We could check if we actually announced the capability but
2202 	 * as long as the message is correctly encoded we don't care.
2203 	 */
2204 
2205 	/* afi, 2 byte */
2206 	memcpy(&afi, p, sizeof(afi));
2207 	afi = ntohs(afi);
2208 	p += 2;
2209 	/* reserved, 1 byte */
2210 	p += 1;
2211 	/* safi, 1 byte */
2212 	memcpy(&safi, p, sizeof(safi));
2213 
2214 	/* afi/safi unchecked -	unrecognized values will be ignored anyway */
2215 	if (afi2aid(afi, safi, &aid) == -1) {
2216 		log_peer_warnx(&peer->conf, "peer sent bad refresh, "
2217 		    "invalid afi/safi pair");
2218 		return (0);
2219 	}
2220 
2221 	if (imsg_rde(IMSG_REFRESH, peer->conf.id, &aid, sizeof(aid)) == -1)
2222 		return (-1);
2223 
2224 	return (0);
2225 }
2226 
2227 int
2228 parse_notification(struct peer *peer)
2229 {
2230 	u_char		*p;
2231 	u_int16_t	 datalen;
2232 	u_int8_t	 errcode;
2233 	u_int8_t	 subcode;
2234 	u_int8_t	 capa_code;
2235 	u_int8_t	 capa_len;
2236 	size_t		 shutcomm_len;
2237 	u_int8_t	 i;
2238 
2239 	/* just log */
2240 	p = peer->rbuf->rptr;
2241 	p += MSGSIZE_HEADER_MARKER;
2242 	memcpy(&datalen, p, sizeof(datalen));
2243 	datalen = ntohs(datalen);
2244 
2245 	p = peer->rbuf->rptr;
2246 	p += MSGSIZE_HEADER;	/* header is already checked */
2247 	datalen -= MSGSIZE_HEADER;
2248 
2249 	memcpy(&errcode, p, sizeof(errcode));
2250 	p += sizeof(errcode);
2251 	datalen -= sizeof(errcode);
2252 
2253 	memcpy(&subcode, p, sizeof(subcode));
2254 	p += sizeof(subcode);
2255 	datalen -= sizeof(subcode);
2256 
2257 	log_notification(peer, errcode, subcode, p, datalen, "received");
2258 	peer->errcnt++;
2259 	peer->stats.last_rcvd_errcode = errcode;
2260 	peer->stats.last_rcvd_suberr = subcode;
2261 
2262 	if (errcode == ERR_OPEN && subcode == ERR_OPEN_CAPA) {
2263 		if (datalen == 0) {	/* zebra likes to send those.. humbug */
2264 			log_peer_warnx(&peer->conf, "received \"unsupported "
2265 			    "capability\" notification without data part, "
2266 			    "disabling capability announcements altogether");
2267 			session_capa_ann_none(peer);
2268 		}
2269 
2270 		while (datalen > 0) {
2271 			if (datalen < 2) {
2272 				log_peer_warnx(&peer->conf,
2273 				    "parse_notification: "
2274 				    "expect len >= 2, len is %u", datalen);
2275 				return (-1);
2276 			}
2277 			memcpy(&capa_code, p, sizeof(capa_code));
2278 			p += sizeof(capa_code);
2279 			datalen -= sizeof(capa_code);
2280 			memcpy(&capa_len, p, sizeof(capa_len));
2281 			p += sizeof(capa_len);
2282 			datalen -= sizeof(capa_len);
2283 			if (datalen < capa_len) {
2284 				log_peer_warnx(&peer->conf,
2285 				    "parse_notification: capa_len %u exceeds "
2286 				    "remaining msg length %u", capa_len,
2287 				    datalen);
2288 				return (-1);
2289 			}
2290 			p += capa_len;
2291 			datalen -= capa_len;
2292 			switch (capa_code) {
2293 			case CAPA_MP:
2294 				for (i = 0; i < AID_MAX; i++)
2295 					peer->capa.ann.mp[i] = 0;
2296 				log_peer_warnx(&peer->conf,
2297 				    "disabling multiprotocol capability");
2298 				break;
2299 			case CAPA_REFRESH:
2300 				peer->capa.ann.refresh = 0;
2301 				log_peer_warnx(&peer->conf,
2302 				    "disabling route refresh capability");
2303 				break;
2304 			case CAPA_RESTART:
2305 				peer->capa.ann.grestart.restart = 0;
2306 				log_peer_warnx(&peer->conf,
2307 				    "disabling restart capability");
2308 				break;
2309 			case CAPA_AS4BYTE:
2310 				peer->capa.ann.as4byte = 0;
2311 				log_peer_warnx(&peer->conf,
2312 				    "disabling 4-byte AS num capability");
2313 				break;
2314 			default:	/* should not happen... */
2315 				log_peer_warnx(&peer->conf, "received "
2316 				    "\"unsupported capability\" notification "
2317 				    "for unknown capability %u, disabling "
2318 				    "capability announcements altogether",
2319 				    capa_code);
2320 				session_capa_ann_none(peer);
2321 				break;
2322 			}
2323 		}
2324 
2325 		return (1);
2326 	}
2327 
2328 	if (errcode == ERR_OPEN && subcode == ERR_OPEN_OPT) {
2329 		session_capa_ann_none(peer);
2330 		return (1);
2331 	}
2332 
2333 	if (errcode == ERR_CEASE &&
2334 	    (subcode == ERR_CEASE_ADMIN_DOWN ||
2335 	     subcode == ERR_CEASE_ADMIN_RESET)) {
2336 		if (datalen > 1) {
2337 			shutcomm_len = *p++;
2338 			datalen--;
2339 			if (datalen < shutcomm_len) {
2340 			    log_peer_warnx(&peer->conf,
2341 				"received truncated shutdown reason");
2342 			    return (0);
2343 			}
2344 			if (shutcomm_len > SHUT_COMM_LEN - 1) {
2345 			    log_peer_warnx(&peer->conf,
2346 				"received overly long shutdown reason");
2347 			    return (0);
2348 			}
2349 			memcpy(peer->stats.last_shutcomm, p, shutcomm_len);
2350 			peer->stats.last_shutcomm[shutcomm_len] = '\0';
2351 			log_peer_warnx(&peer->conf,
2352 			    "received shutdown reason: \"%s\"",
2353 			    log_shutcomm(peer->stats.last_shutcomm));
2354 			p += shutcomm_len;
2355 			datalen -= shutcomm_len;
2356 		}
2357 	}
2358 
2359 	return (0);
2360 }
2361 
2362 int
2363 parse_capabilities(struct peer *peer, u_char *d, u_int16_t dlen, u_int32_t *as)
2364 {
2365 	u_char		*capa_val;
2366 	u_int32_t	 remote_as;
2367 	u_int16_t	 len;
2368 	u_int16_t	 afi;
2369 	u_int16_t	 gr_header;
2370 	u_int8_t	 safi;
2371 	u_int8_t	 aid;
2372 	u_int8_t	 gr_flags;
2373 	u_int8_t	 capa_code;
2374 	u_int8_t	 capa_len;
2375 	u_int8_t	 i;
2376 
2377 	len = dlen;
2378 	while (len > 0) {
2379 		if (len < 2) {
2380 			log_peer_warnx(&peer->conf, "Bad capabilities attr "
2381 			    "length: %u, too short", len);
2382 			return (-1);
2383 		}
2384 		memcpy(&capa_code, d, sizeof(capa_code));
2385 		d += sizeof(capa_code);
2386 		len -= sizeof(capa_code);
2387 		memcpy(&capa_len, d, sizeof(capa_len));
2388 		d += sizeof(capa_len);
2389 		len -= sizeof(capa_len);
2390 		if (capa_len > 0) {
2391 			if (len < capa_len) {
2392 				log_peer_warnx(&peer->conf,
2393 				    "Bad capabilities attr length: "
2394 				    "len %u smaller than capa_len %u",
2395 				    len, capa_len);
2396 				return (-1);
2397 			}
2398 			capa_val = d;
2399 			d += capa_len;
2400 			len -= capa_len;
2401 		} else
2402 			capa_val = NULL;
2403 
2404 		switch (capa_code) {
2405 		case CAPA_MP:			/* RFC 4760 */
2406 			if (capa_len != 4) {
2407 				log_peer_warnx(&peer->conf,
2408 				    "Bad multi protocol capability length: "
2409 				    "%u", capa_len);
2410 				break;
2411 			}
2412 			memcpy(&afi, capa_val, sizeof(afi));
2413 			afi = ntohs(afi);
2414 			memcpy(&safi, capa_val + 3, sizeof(safi));
2415 			if (afi2aid(afi, safi, &aid) == -1) {
2416 				log_peer_warnx(&peer->conf,
2417 				    "Received multi protocol capability: "
2418 				    " unknown AFI %u, safi %u pair",
2419 				    afi, safi);
2420 				break;
2421 			}
2422 			peer->capa.peer.mp[aid] = 1;
2423 			break;
2424 		case CAPA_REFRESH:
2425 			peer->capa.peer.refresh = 1;
2426 			break;
2427 		case CAPA_RESTART:
2428 			if (capa_len == 2) {
2429 				/* peer only supports EoR marker */
2430 				peer->capa.peer.grestart.restart = 1;
2431 				peer->capa.peer.grestart.timeout = 0;
2432 				break;
2433 			} else if (capa_len % 4 != 2) {
2434 				log_peer_warnx(&peer->conf,
2435 				    "Bad graceful restart capability length: "
2436 				    "%u", capa_len);
2437 				peer->capa.peer.grestart.restart = 0;
2438 				peer->capa.peer.grestart.timeout = 0;
2439 				break;
2440 			}
2441 
2442 			memcpy(&gr_header, capa_val, sizeof(gr_header));
2443 			gr_header = ntohs(gr_header);
2444 			peer->capa.peer.grestart.timeout =
2445 			    gr_header & CAPA_GR_TIMEMASK;
2446 			if (peer->capa.peer.grestart.timeout == 0) {
2447 				log_peer_warnx(&peer->conf, "Received "
2448 				    "graceful restart timeout is zero");
2449 				peer->capa.peer.grestart.restart = 0;
2450 				break;
2451 			}
2452 
2453 			for (i = 2; i <= capa_len - 4; i += 4) {
2454 				memcpy(&afi, capa_val + i, sizeof(afi));
2455 				afi = ntohs(afi);
2456 				memcpy(&safi, capa_val + i + 2, sizeof(safi));
2457 				if (afi2aid(afi, safi, &aid) == -1) {
2458 					log_peer_warnx(&peer->conf,
2459 					    "Received graceful restart capa: "
2460 					    " unknown AFI %u, safi %u pair",
2461 					    afi, safi);
2462 					continue;
2463 				}
2464 				memcpy(&gr_flags, capa_val + i + 3,
2465 				    sizeof(gr_flags));
2466 				peer->capa.peer.grestart.flags[aid] |=
2467 				    CAPA_GR_PRESENT;
2468 				if (gr_flags & CAPA_GR_F_FLAG)
2469 					peer->capa.peer.grestart.flags[aid] |=
2470 					    CAPA_GR_FORWARD;
2471 				if (gr_header & CAPA_GR_R_FLAG)
2472 					peer->capa.peer.grestart.flags[aid] |=
2473 					    CAPA_GR_RESTART;
2474 				peer->capa.peer.grestart.restart = 2;
2475 			}
2476 			break;
2477 		case CAPA_AS4BYTE:
2478 			if (capa_len != 4) {
2479 				log_peer_warnx(&peer->conf,
2480 				    "Bad AS4BYTE capability length: "
2481 				    "%u", capa_len);
2482 				peer->capa.peer.as4byte = 0;
2483 				break;
2484 			}
2485 			memcpy(&remote_as, capa_val, sizeof(remote_as));
2486 			*as = ntohl(remote_as);
2487 			if (*as == 0) {
2488 				log_peer_warnx(&peer->conf,
2489 				    "peer requests unacceptable AS %u", *as);
2490 				session_notification(peer, ERR_OPEN,
2491 				    ERR_OPEN_AS, NULL, 0);
2492 				change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
2493 				return (-1);
2494 			}
2495 			peer->capa.peer.as4byte = 1;
2496 			break;
2497 		default:
2498 			break;
2499 		}
2500 	}
2501 
2502 	return (0);
2503 }
2504 
2505 int
2506 capa_neg_calc(struct peer *p)
2507 {
2508 	u_int8_t	i, hasmp = 0;
2509 
2510 	/* refresh: does not realy matter here, use peer setting */
2511 	p->capa.neg.refresh = p->capa.peer.refresh;
2512 
2513 	/* as4byte: both side must announce capability */
2514 	if (p->capa.ann.as4byte && p->capa.peer.as4byte)
2515 		p->capa.neg.as4byte = 1;
2516 	else
2517 		p->capa.neg.as4byte = 0;
2518 
2519 	/* MP: both side must announce capability */
2520 	for (i = 0; i < AID_MAX; i++) {
2521 		if (p->capa.ann.mp[i] && p->capa.peer.mp[i]) {
2522 			p->capa.neg.mp[i] = 1;
2523 			hasmp = 1;
2524 		} else
2525 			p->capa.neg.mp[i] = 0;
2526 	}
2527 	/* if no MP capability present default to IPv4 unicast mode */
2528 	if (!hasmp)
2529 		p->capa.neg.mp[AID_INET] = 1;
2530 
2531 	/*
2532 	 * graceful restart: only the peer capabilities are of interest here.
2533 	 * It is necessary to compare the new values with the previous ones
2534 	 * and act acordingly. AFI/SAFI that are not part in the MP capability
2535 	 * are treated as not being present.
2536 	 */
2537 
2538 	for (i = 0; i < AID_MAX; i++) {
2539 		int8_t	negflags;
2540 
2541 		/* disable GR if the AFI/SAFI is not present */
2542 		if (p->capa.peer.grestart.flags[i] & CAPA_GR_PRESENT &&
2543 		    p->capa.neg.mp[i] == 0)
2544 			p->capa.peer.grestart.flags[i] = 0;	/* disable */
2545 		/* look at current GR state and decide what to do */
2546 		negflags = p->capa.neg.grestart.flags[i];
2547 		p->capa.neg.grestart.flags[i] = p->capa.peer.grestart.flags[i];
2548 		if (negflags & CAPA_GR_RESTARTING) {
2549 			if (!(p->capa.peer.grestart.flags[i] &
2550 			    CAPA_GR_FORWARD)) {
2551 				if (imsg_rde(IMSG_SESSION_FLUSH, p->conf.id,
2552 				    &i, sizeof(i)) == -1)
2553 					return (-1);
2554 				log_peer_warnx(&p->conf, "graceful restart of "
2555 				    "%s, not restarted, flushing", aid2str(i));
2556 			} else
2557 				p->capa.neg.grestart.flags[i] |=
2558 				    CAPA_GR_RESTARTING;
2559 		}
2560 	}
2561 	p->capa.neg.grestart.timeout = p->capa.peer.grestart.timeout;
2562 	p->capa.neg.grestart.restart = p->capa.peer.grestart.restart;
2563 
2564 	return (0);
2565 }
2566 
2567 void
2568 session_dispatch_imsg(struct imsgbuf *ibuf, int idx, u_int *listener_cnt)
2569 {
2570 	struct imsg		 imsg;
2571 	struct mrt		 xmrt;
2572 	struct mrt		*mrt;
2573 	struct imsgbuf		*i;
2574 	struct peer		*p;
2575 	struct listen_addr	*la, *nla;
2576 	struct kif		*kif;
2577 	u_char			*data;
2578 	int			 n, fd, depend_ok, restricted;
2579 	u_int16_t		 t;
2580 	u_int8_t		 aid, errcode, subcode;
2581 
2582 	while (ibuf) {
2583 		if ((n = imsg_get(ibuf, &imsg)) == -1)
2584 			fatal("session_dispatch_imsg: imsg_get error");
2585 
2586 		if (n == 0)
2587 			break;
2588 
2589 		switch (imsg.hdr.type) {
2590 		case IMSG_SOCKET_CONN:
2591 		case IMSG_SOCKET_CONN_CTL:
2592 			if (idx != PFD_PIPE_MAIN)
2593 				fatalx("reconf request not from parent");
2594 			if ((fd = imsg.fd) == -1) {
2595 				log_warnx("expected to receive imsg fd to "
2596 				    "RDE but didn't receive any");
2597 				break;
2598 			}
2599 			if ((i = malloc(sizeof(struct imsgbuf))) == NULL)
2600 				fatal(NULL);
2601 			imsg_init(i, fd);
2602 			if (imsg.hdr.type == IMSG_SOCKET_CONN) {
2603 				if (ibuf_rde) {
2604 					log_warnx("Unexpected imsg connection "
2605 					    "to RDE received");
2606 					msgbuf_clear(&ibuf_rde->w);
2607 					free(ibuf_rde);
2608 				}
2609 				ibuf_rde = i;
2610 			} else {
2611 				if (ibuf_rde_ctl) {
2612 					log_warnx("Unexpected imsg ctl "
2613 					    "connection to RDE received");
2614 					msgbuf_clear(&ibuf_rde_ctl->w);
2615 					free(ibuf_rde_ctl);
2616 				}
2617 				ibuf_rde_ctl = i;
2618 			}
2619 			break;
2620 		case IMSG_RECONF_CONF:
2621 			if (idx != PFD_PIPE_MAIN)
2622 				fatalx("reconf request not from parent");
2623 			nconf = new_config();
2624 
2625 			copy_config(nconf, imsg.data);
2626 			pending_reconf = 1;
2627 			break;
2628 		case IMSG_RECONF_PEER:
2629 			if (idx != PFD_PIPE_MAIN)
2630 				fatalx("reconf request not from parent");
2631 			if ((p = calloc(1, sizeof(struct peer))) == NULL)
2632 				fatal("new_peer");
2633 			memcpy(&p->conf, imsg.data, sizeof(struct peer_config));
2634 			p->state = p->prev_state = STATE_NONE;
2635 			p->reconf_action = RECONF_REINIT;
2636 			if (RB_INSERT(peer_head, &nconf->peers, p) != NULL)
2637 				fatalx("%s: peer tree is corrupt", __func__);
2638 			break;
2639 		case IMSG_RECONF_LISTENER:
2640 			if (idx != PFD_PIPE_MAIN)
2641 				fatalx("reconf request not from parent");
2642 			if (nconf == NULL)
2643 				fatalx("IMSG_RECONF_LISTENER but no config");
2644 			nla = imsg.data;
2645 			TAILQ_FOREACH(la, conf->listen_addrs, entry)
2646 				if (!la_cmp(la, nla))
2647 					break;
2648 
2649 			if (la == NULL) {
2650 				if (nla->reconf != RECONF_REINIT)
2651 					fatalx("king bula sez: "
2652 					    "expected REINIT");
2653 
2654 				if ((nla->fd = imsg.fd) == -1)
2655 					log_warnx("expected to receive fd for "
2656 					    "%s but didn't receive any",
2657 					    log_sockaddr((struct sockaddr *)
2658 					    &nla->sa, nla->sa_len));
2659 
2660 				la = calloc(1, sizeof(struct listen_addr));
2661 				if (la == NULL)
2662 					fatal(NULL);
2663 				memcpy(&la->sa, &nla->sa, sizeof(la->sa));
2664 				la->flags = nla->flags;
2665 				la->fd = nla->fd;
2666 				la->reconf = RECONF_REINIT;
2667 				TAILQ_INSERT_TAIL(nconf->listen_addrs, la,
2668 				    entry);
2669 			} else {
2670 				if (nla->reconf != RECONF_KEEP)
2671 					fatalx("king bula sez: expected KEEP");
2672 				la->reconf = RECONF_KEEP;
2673 			}
2674 
2675 			break;
2676 		case IMSG_RECONF_CTRL:
2677 			if (idx != PFD_PIPE_MAIN)
2678 				fatalx("reconf request not from parent");
2679 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
2680 			    sizeof(restricted))
2681 				fatalx("IFINFO imsg with wrong len");
2682 			memcpy(&restricted, imsg.data, sizeof(restricted));
2683 			if (imsg.fd == -1) {
2684 				log_warnx("expected to receive fd for control "
2685 				    "socket but didn't receive any");
2686 				break;
2687 			}
2688 			if (restricted) {
2689 				control_shutdown(rcsock);
2690 				rcsock = imsg.fd;
2691 			} else {
2692 				control_shutdown(csock);
2693 				csock = imsg.fd;
2694 			}
2695 			break;
2696 		case IMSG_RECONF_DRAIN:
2697 			if (idx != PFD_PIPE_MAIN)
2698 				fatalx("reconf request not from parent");
2699 			imsg_compose(ibuf_main, IMSG_RECONF_DRAIN, 0, 0,
2700 			    -1, NULL, 0);
2701 			break;
2702 		case IMSG_RECONF_DONE:
2703 			if (idx != PFD_PIPE_MAIN)
2704 				fatalx("reconf request not from parent");
2705 			if (nconf == NULL)
2706 				fatalx("got IMSG_RECONF_DONE but no config");
2707 			copy_config(conf, nconf);
2708 			merge_peers(conf, nconf);
2709 
2710 			/* delete old listeners */
2711 			for (la = TAILQ_FIRST(conf->listen_addrs); la != NULL;
2712 			    la = nla) {
2713 				nla = TAILQ_NEXT(la, entry);
2714 				if (la->reconf == RECONF_NONE) {
2715 					log_info("not listening on %s any more",
2716 					    log_sockaddr((struct sockaddr *)
2717 					    &la->sa, la->sa_len));
2718 					TAILQ_REMOVE(conf->listen_addrs, la,
2719 					    entry);
2720 					close(la->fd);
2721 					free(la);
2722 				}
2723 			}
2724 
2725 			/* add new listeners */
2726 			while ((la = TAILQ_FIRST(nconf->listen_addrs)) !=
2727 			    NULL) {
2728 				TAILQ_REMOVE(nconf->listen_addrs, la, entry);
2729 				TAILQ_INSERT_TAIL(conf->listen_addrs, la,
2730 				    entry);
2731 			}
2732 
2733 			setup_listeners(listener_cnt);
2734 			free_config(nconf);
2735 			nconf = NULL;
2736 			pending_reconf = 0;
2737 			log_info("SE reconfigured");
2738 			imsg_compose(ibuf_main, IMSG_RECONF_DONE, 0, 0,
2739 			    -1, NULL, 0);
2740 			break;
2741 		case IMSG_IFINFO:
2742 			if (idx != PFD_PIPE_MAIN)
2743 				fatalx("IFINFO message not from parent");
2744 			if (imsg.hdr.len != IMSG_HEADER_SIZE +
2745 			    sizeof(struct kif))
2746 				fatalx("IFINFO imsg with wrong len");
2747 			kif = imsg.data;
2748 			depend_ok = kif->depend_state;
2749 
2750 			RB_FOREACH(p, peer_head, &conf->peers)
2751 				if (!strcmp(p->conf.if_depend, kif->ifname)) {
2752 					if (depend_ok && !p->depend_ok) {
2753 						p->depend_ok = depend_ok;
2754 						bgp_fsm(p, EVNT_START);
2755 					} else if (!depend_ok && p->depend_ok) {
2756 						p->depend_ok = depend_ok;
2757 						session_stop(p,
2758 						    ERR_CEASE_OTHER_CHANGE);
2759 					}
2760 				}
2761 			break;
2762 		case IMSG_MRT_OPEN:
2763 		case IMSG_MRT_REOPEN:
2764 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2765 			    sizeof(struct mrt)) {
2766 				log_warnx("wrong imsg len");
2767 				break;
2768 			}
2769 
2770 			memcpy(&xmrt, imsg.data, sizeof(struct mrt));
2771 			if ((xmrt.wbuf.fd = imsg.fd) == -1)
2772 				log_warnx("expected to receive fd for mrt dump "
2773 				    "but didn't receive any");
2774 
2775 			mrt = mrt_get(&mrthead, &xmrt);
2776 			if (mrt == NULL) {
2777 				/* new dump */
2778 				mrt = calloc(1, sizeof(struct mrt));
2779 				if (mrt == NULL)
2780 					fatal("session_dispatch_imsg");
2781 				memcpy(mrt, &xmrt, sizeof(struct mrt));
2782 				TAILQ_INIT(&mrt->wbuf.bufs);
2783 				LIST_INSERT_HEAD(&mrthead, mrt, entry);
2784 			} else {
2785 				/* old dump reopened */
2786 				close(mrt->wbuf.fd);
2787 				mrt->wbuf.fd = xmrt.wbuf.fd;
2788 			}
2789 			break;
2790 		case IMSG_MRT_CLOSE:
2791 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2792 			    sizeof(struct mrt)) {
2793 				log_warnx("wrong imsg len");
2794 				break;
2795 			}
2796 
2797 			memcpy(&xmrt, imsg.data, sizeof(struct mrt));
2798 			mrt = mrt_get(&mrthead, &xmrt);
2799 			if (mrt != NULL)
2800 				mrt_done(mrt);
2801 			break;
2802 		case IMSG_CTL_KROUTE:
2803 		case IMSG_CTL_KROUTE_ADDR:
2804 		case IMSG_CTL_SHOW_NEXTHOP:
2805 		case IMSG_CTL_SHOW_INTERFACE:
2806 		case IMSG_CTL_SHOW_FIB_TABLES:
2807 			if (idx != PFD_PIPE_MAIN)
2808 				fatalx("ctl kroute request not from parent");
2809 			control_imsg_relay(&imsg);
2810 			break;
2811 		case IMSG_CTL_SHOW_RIB:
2812 		case IMSG_CTL_SHOW_RIB_PREFIX:
2813 		case IMSG_CTL_SHOW_RIB_COMMUNITIES:
2814 		case IMSG_CTL_SHOW_RIB_ATTR:
2815 		case IMSG_CTL_SHOW_RIB_MEM:
2816 		case IMSG_CTL_SHOW_RIB_HASH:
2817 		case IMSG_CTL_SHOW_NETWORK:
2818 		case IMSG_CTL_SHOW_NEIGHBOR:
2819 			if (idx != PFD_PIPE_ROUTE_CTL)
2820 				fatalx("ctl rib request not from RDE");
2821 			control_imsg_relay(&imsg);
2822 			break;
2823 		case IMSG_CTL_END:
2824 		case IMSG_CTL_RESULT:
2825 			control_imsg_relay(&imsg);
2826 			break;
2827 		case IMSG_UPDATE:
2828 			if (idx != PFD_PIPE_ROUTE)
2829 				fatalx("update request not from RDE");
2830 			if (imsg.hdr.len > IMSG_HEADER_SIZE +
2831 			    MAX_PKTSIZE - MSGSIZE_HEADER ||
2832 			    imsg.hdr.len < IMSG_HEADER_SIZE +
2833 			    MSGSIZE_UPDATE_MIN - MSGSIZE_HEADER)
2834 				log_warnx("RDE sent invalid update");
2835 			else
2836 				session_update(imsg.hdr.peerid, imsg.data,
2837 				    imsg.hdr.len - IMSG_HEADER_SIZE);
2838 			break;
2839 		case IMSG_UPDATE_ERR:
2840 			if (idx != PFD_PIPE_ROUTE)
2841 				fatalx("update request not from RDE");
2842 			if (imsg.hdr.len < IMSG_HEADER_SIZE + 2) {
2843 				log_warnx("RDE sent invalid notification");
2844 				break;
2845 			}
2846 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2847 				log_warnx("no such peer: id=%u",
2848 				    imsg.hdr.peerid);
2849 				break;
2850 			}
2851 			data = imsg.data;
2852 			errcode = *data++;
2853 			subcode = *data++;
2854 
2855 			if (imsg.hdr.len == IMSG_HEADER_SIZE + 2)
2856 				data = NULL;
2857 
2858 			session_notification(p, errcode, subcode,
2859 			    data, imsg.hdr.len - IMSG_HEADER_SIZE - 2);
2860 			switch (errcode) {
2861 			case ERR_CEASE:
2862 				switch (subcode) {
2863 				case ERR_CEASE_MAX_PREFIX:
2864 				case ERR_CEASE_MAX_SENT_PREFIX:
2865 					t = p->conf.max_out_prefix_restart;
2866 					if (subcode == ERR_CEASE_MAX_PREFIX)
2867 						t = p->conf.max_prefix_restart;
2868 
2869 					bgp_fsm(p, EVNT_STOP);
2870 					if (t)
2871 						timer_set(p, Timer_IdleHold,
2872 						    60 * t);
2873 					break;
2874 				default:
2875 					bgp_fsm(p, EVNT_CON_FATAL);
2876 					break;
2877 				}
2878 				break;
2879 			default:
2880 				bgp_fsm(p, EVNT_CON_FATAL);
2881 				break;
2882 			}
2883 			break;
2884 		case IMSG_SESSION_RESTARTED:
2885 			if (idx != PFD_PIPE_ROUTE)
2886 				fatalx("update request not from RDE");
2887 			if (imsg.hdr.len < IMSG_HEADER_SIZE + sizeof(aid)) {
2888 				log_warnx("RDE sent invalid restart msg");
2889 				break;
2890 			}
2891 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2892 				log_warnx("no such peer: id=%u",
2893 				    imsg.hdr.peerid);
2894 				break;
2895 			}
2896 			memcpy(&aid, imsg.data, sizeof(aid));
2897 			if (aid >= AID_MAX)
2898 				fatalx("IMSG_SESSION_RESTARTED: bad AID");
2899 			if (p->capa.neg.grestart.flags[aid] &
2900 			    CAPA_GR_RESTARTING) {
2901 				log_peer_warnx(&p->conf,
2902 				    "graceful restart of %s finished",
2903 				    aid2str(aid));
2904 				p->capa.neg.grestart.flags[aid] &=
2905 				    ~CAPA_GR_RESTARTING;
2906 				timer_stop(p, Timer_RestartTimeout);
2907 
2908 				/* signal back to RDE to cleanup stale routes */
2909 				if (imsg_rde(IMSG_SESSION_RESTARTED,
2910 				    imsg.hdr.peerid, &aid, sizeof(aid)) == -1)
2911 					fatal("imsg_compose: "
2912 					    "IMSG_SESSION_RESTARTED");
2913 			}
2914 			break;
2915 		case IMSG_SESSION_DOWN:
2916 			if (idx != PFD_PIPE_ROUTE)
2917 				fatalx("update request not from RDE");
2918 			if ((p = getpeerbyid(conf, imsg.hdr.peerid)) == NULL) {
2919 				log_warnx("no such peer: id=%u",
2920 				    imsg.hdr.peerid);
2921 				break;
2922 			}
2923 			session_stop(p, ERR_CEASE_ADMIN_DOWN);
2924 			break;
2925 		default:
2926 			break;
2927 		}
2928 		imsg_free(&imsg);
2929 	}
2930 }
2931 
2932 int
2933 la_cmp(struct listen_addr *a, struct listen_addr *b)
2934 {
2935 	struct sockaddr_in	*in_a, *in_b;
2936 	struct sockaddr_in6	*in6_a, *in6_b;
2937 
2938 	if (a->sa.ss_family != b->sa.ss_family)
2939 		return (1);
2940 
2941 	switch (a->sa.ss_family) {
2942 	case AF_INET:
2943 		in_a = (struct sockaddr_in *)&a->sa;
2944 		in_b = (struct sockaddr_in *)&b->sa;
2945 		if (in_a->sin_addr.s_addr != in_b->sin_addr.s_addr)
2946 			return (1);
2947 		if (in_a->sin_port != in_b->sin_port)
2948 			return (1);
2949 		break;
2950 	case AF_INET6:
2951 		in6_a = (struct sockaddr_in6 *)&a->sa;
2952 		in6_b = (struct sockaddr_in6 *)&b->sa;
2953 		if (bcmp(&in6_a->sin6_addr, &in6_b->sin6_addr,
2954 		    sizeof(struct in6_addr)))
2955 			return (1);
2956 		if (in6_a->sin6_port != in6_b->sin6_port)
2957 			return (1);
2958 		break;
2959 	default:
2960 		fatal("king bula sez: unknown address family");
2961 		/* NOTREACHED */
2962 	}
2963 
2964 	return (0);
2965 }
2966 
2967 struct peer *
2968 getpeerbydesc(struct bgpd_config *c, const char *descr)
2969 {
2970 	struct peer	*p, *res = NULL;
2971 	int		 match = 0;
2972 
2973 	RB_FOREACH(p, peer_head, &c->peers)
2974 		if (!strcmp(p->conf.descr, descr)) {
2975 			res = p;
2976 			match++;
2977 		}
2978 
2979 	if (match > 1)
2980 		log_info("neighbor description \"%s\" not unique, request "
2981 		    "aborted", descr);
2982 
2983 	if (match == 1)
2984 		return (res);
2985 	else
2986 		return (NULL);
2987 }
2988 
2989 struct peer *
2990 getpeerbyip(struct bgpd_config *c, struct sockaddr *ip)
2991 {
2992 	struct bgpd_addr addr;
2993 	struct peer	*p, *newpeer, *loose = NULL;
2994 	u_int32_t	 id;
2995 
2996 	sa2addr(ip, &addr, NULL);
2997 
2998 	/* we might want a more effective way to find peers by IP */
2999 	RB_FOREACH(p, peer_head, &c->peers)
3000 		if (!p->conf.template &&
3001 		    !memcmp(&addr, &p->conf.remote_addr, sizeof(addr)))
3002 			return (p);
3003 
3004 	/* try template matching */
3005 	RB_FOREACH(p, peer_head, &c->peers)
3006 		if (p->conf.template &&
3007 		    p->conf.remote_addr.aid == addr.aid &&
3008 		    session_match_mask(p, &addr))
3009 			if (loose == NULL || loose->conf.remote_masklen <
3010 			    p->conf.remote_masklen)
3011 				loose = p;
3012 
3013 	if (loose != NULL) {
3014 		/* clone */
3015 		if ((newpeer = malloc(sizeof(struct peer))) == NULL)
3016 			fatal(NULL);
3017 		memcpy(newpeer, loose, sizeof(struct peer));
3018 		for (id = PEER_ID_DYN_MAX; id > PEER_ID_STATIC_MAX; id--) {
3019 			if (getpeerbyid(c, id) == NULL)	/* we found a free id */
3020 				break;
3021 		}
3022 		newpeer->template = loose;
3023 		session_template_clone(newpeer, ip, id, 0);
3024 		newpeer->state = newpeer->prev_state = STATE_NONE;
3025 		newpeer->reconf_action = RECONF_KEEP;
3026 		newpeer->rbuf = NULL;
3027 		newpeer->rpending = 0;
3028 		init_peer(newpeer);
3029 		bgp_fsm(newpeer, EVNT_START);
3030 		if (RB_INSERT(peer_head, &c->peers, newpeer) != NULL)
3031 			fatalx("%s: peer tree is corrupt", __func__);
3032 		return (newpeer);
3033 	}
3034 
3035 	return (NULL);
3036 }
3037 
3038 struct peer *
3039 getpeerbyid(struct bgpd_config *c, u_int32_t peerid)
3040 {
3041 	static struct peer lookup;
3042 
3043 	lookup.conf.id = peerid;
3044 
3045 	return RB_FIND(peer_head, &c->peers, &lookup);
3046 }
3047 
3048 int
3049 peer_matched(struct peer *p, struct ctl_neighbor *n)
3050 {
3051 	char *s;
3052 
3053 	if (n && n->addr.aid) {
3054 		if (memcmp(&p->conf.remote_addr, &n->addr,
3055 		    sizeof(p->conf.remote_addr)))
3056 			return 0;
3057 	} else if (n && n->descr[0]) {
3058 		s = n->is_group ? p->conf.group : p->conf.descr;
3059 		if (strcmp(s, n->descr))
3060 			return 0;
3061 	}
3062 	return 1;
3063 }
3064 
3065 void
3066 session_template_clone(struct peer *p, struct sockaddr *ip, u_int32_t id,
3067     u_int32_t as)
3068 {
3069 	struct bgpd_addr	remote_addr;
3070 
3071 	if (ip)
3072 		sa2addr(ip, &remote_addr, NULL);
3073 	else
3074 		memcpy(&remote_addr, &p->conf.remote_addr, sizeof(remote_addr));
3075 
3076 	memcpy(&p->conf, &p->template->conf, sizeof(struct peer_config));
3077 
3078 	p->conf.id = id;
3079 
3080 	if (as) {
3081 		p->conf.remote_as = as;
3082 		p->conf.ebgp = (p->conf.remote_as != p->conf.local_as);
3083 		if (!p->conf.ebgp)
3084 			/* force enforce_as off for iBGP sessions */
3085 			p->conf.enforce_as = ENFORCE_AS_OFF;
3086 	}
3087 
3088 	memcpy(&p->conf.remote_addr, &remote_addr, sizeof(remote_addr));
3089 	switch (p->conf.remote_addr.aid) {
3090 	case AID_INET:
3091 		p->conf.remote_masklen = 32;
3092 		break;
3093 	case AID_INET6:
3094 		p->conf.remote_masklen = 128;
3095 		break;
3096 	}
3097 	p->conf.template = 0;
3098 }
3099 
3100 int
3101 session_match_mask(struct peer *p, struct bgpd_addr *a)
3102 {
3103 	struct in_addr	 v4masked;
3104 	struct in6_addr	 v6masked;
3105 
3106 	switch (p->conf.remote_addr.aid) {
3107 	case AID_INET:
3108 		inet4applymask(&v4masked, &a->v4, p->conf.remote_masklen);
3109 		if (p->conf.remote_addr.v4.s_addr == v4masked.s_addr)
3110 			return (1);
3111 		return (0);
3112 	case AID_INET6:
3113 		inet6applymask(&v6masked, &a->v6, p->conf.remote_masklen);
3114 
3115 		if (memcmp(&v6masked, &p->conf.remote_addr.v6,
3116 		    sizeof(v6masked)) == 0)
3117 			return (1);
3118 		return (0);
3119 	}
3120 	return (0);
3121 }
3122 
3123 void
3124 session_down(struct peer *peer)
3125 {
3126 	bzero(&peer->capa.neg, sizeof(peer->capa.neg));
3127 	peer->stats.last_updown = getmonotime();
3128 	/*
3129 	 * session_down is called in the exit code path so check
3130 	 * if the RDE is still around, if not there is no need to
3131 	 * send the message.
3132 	 */
3133 	if (ibuf_rde == NULL)
3134 		return;
3135 	if (imsg_rde(IMSG_SESSION_DOWN, peer->conf.id, NULL, 0) == -1)
3136 		fatalx("imsg_compose error");
3137 }
3138 
3139 void
3140 session_up(struct peer *p)
3141 {
3142 	struct session_up	 sup;
3143 
3144 	if (imsg_rde(IMSG_SESSION_ADD, p->conf.id,
3145 	    &p->conf, sizeof(p->conf)) == -1)
3146 		fatalx("imsg_compose error");
3147 
3148 	if (p->local.aid == AID_INET) {
3149 		sup.local_v4_addr = p->local;
3150 		sup.local_v6_addr = p->local_alt;
3151 	} else {
3152 		sup.local_v6_addr = p->local;
3153 		sup.local_v4_addr = p->local_alt;
3154 	}
3155 	sup.remote_addr = p->remote;
3156 
3157 	sup.remote_bgpid = p->remote_bgpid;
3158 	sup.short_as = p->short_as;
3159 	memcpy(&sup.capa, &p->capa.neg, sizeof(sup.capa));
3160 	p->stats.last_updown = getmonotime();
3161 	if (imsg_rde(IMSG_SESSION_UP, p->conf.id, &sup, sizeof(sup)) == -1)
3162 		fatalx("imsg_compose error");
3163 }
3164 
3165 int
3166 imsg_ctl_parent(int type, u_int32_t peerid, pid_t pid, void *data,
3167     u_int16_t datalen)
3168 {
3169 	return (imsg_compose(ibuf_main, type, peerid, pid, -1, data, datalen));
3170 }
3171 
3172 int
3173 imsg_ctl_rde(int type, pid_t pid, void *data, u_int16_t datalen)
3174 {
3175 	if (ibuf_rde_ctl == NULL) {
3176 		log_warnx("Can't send message %u to RDE, ctl pipe closed",
3177 		    type);
3178 		return (0);
3179 	}
3180 	/*
3181 	 * Use control socket to talk to RDE to bypass the queue of the
3182 	 * regular imsg socket.
3183 	 */
3184 	return (imsg_compose(ibuf_rde_ctl, type, 0, pid, -1, data, datalen));
3185 }
3186 
3187 int
3188 imsg_rde(int type, uint32_t peerid, void *data, u_int16_t datalen)
3189 {
3190 	if (ibuf_rde == NULL) {
3191 		log_warnx("Can't send message %u to RDE, pipe closed", type);
3192 		return (0);
3193 	}
3194 
3195 	return (imsg_compose(ibuf_rde, type, peerid, 0, -1, data, datalen));
3196 }
3197 
3198 void
3199 session_demote(struct peer *p, int level)
3200 {
3201 	struct demote_msg	msg;
3202 
3203 	strlcpy(msg.demote_group, p->conf.demote_group,
3204 	    sizeof(msg.demote_group));
3205 	msg.level = level;
3206 	if (imsg_compose(ibuf_main, IMSG_DEMOTE, p->conf.id, 0, -1,
3207 	    &msg, sizeof(msg)) == -1)
3208 		fatalx("imsg_compose error");
3209 
3210 	p->demoted += level;
3211 }
3212 
3213 void
3214 session_stop(struct peer *peer, u_int8_t subcode)
3215 {
3216 	char data[SHUT_COMM_LEN];
3217 	size_t datalen;
3218 	size_t shutcomm_len;
3219 	char *communication;
3220 
3221 	datalen = 0;
3222 	communication = peer->conf.shutcomm;
3223 
3224 	if ((subcode == ERR_CEASE_ADMIN_DOWN ||
3225 	    subcode == ERR_CEASE_ADMIN_RESET)
3226 	    && communication && *communication) {
3227 		shutcomm_len = strlen(communication);
3228 		if (shutcomm_len > SHUT_COMM_LEN - 1) {
3229 		    log_peer_warnx(&peer->conf,
3230 			"trying to send overly long shutdown reason");
3231 		} else {
3232 			data[0] = shutcomm_len;
3233 			datalen = shutcomm_len + sizeof(data[0]);
3234 			memcpy(data + 1, communication, shutcomm_len);
3235 		}
3236 	}
3237 	switch (peer->state) {
3238 	case STATE_OPENSENT:
3239 	case STATE_OPENCONFIRM:
3240 	case STATE_ESTABLISHED:
3241 		session_notification(peer, ERR_CEASE, subcode, data, datalen);
3242 		break;
3243 	default:
3244 		/* session not open, no need to send notification */
3245 		break;
3246 	}
3247 	bgp_fsm(peer, EVNT_STOP);
3248 }
3249 
3250 void
3251 merge_peers(struct bgpd_config *c, struct bgpd_config *nc)
3252 {
3253 	struct peer *p, *np, *next;
3254 
3255 	RB_FOREACH(p, peer_head, &c->peers) {
3256 		/* templates are handled specially */
3257 		if (p->template != NULL)
3258 			continue;
3259 		np = getpeerbyid(nc, p->conf.id);
3260 		if (np == NULL) {
3261 			p->reconf_action = RECONF_DELETE;
3262 			continue;
3263 		}
3264 
3265 		/* peer no longer uses TCP MD5SIG so deconfigure */
3266 		if (p->conf.auth.method == AUTH_MD5SIG &&
3267 		    np->conf.auth.method != AUTH_MD5SIG)
3268 			tcp_md5_del_listener(c, p);
3269 		else if (np->conf.auth.method == AUTH_MD5SIG)
3270 			tcp_md5_add_listener(c, np);
3271 
3272 		memcpy(&p->conf, &np->conf, sizeof(p->conf));
3273 		RB_REMOVE(peer_head, &nc->peers, np);
3274 		free(np);
3275 
3276 		p->reconf_action = RECONF_KEEP;
3277 
3278 		/* had demotion, is demoted, demote removed? */
3279 		if (p->demoted && !p->conf.demote_group[0])
3280 			session_demote(p, -1);
3281 
3282 		/* if session is not open then refresh pfkey data */
3283 		if (p->state < STATE_OPENSENT && !p->template)
3284 			imsg_compose(ibuf_main, IMSG_PFKEY_RELOAD,
3285 			    p->conf.id, 0, -1, NULL, 0);
3286 
3287 		/* sync the RDE in case we keep the peer */
3288 		if (imsg_rde(IMSG_SESSION_ADD, p->conf.id,
3289 		    &p->conf, sizeof(struct peer_config)) == -1)
3290 			fatalx("imsg_compose error");
3291 
3292 		/* apply the config to all clones of a template */
3293 		if (p->conf.template) {
3294 			struct peer *xp;
3295 			RB_FOREACH(xp, peer_head, &c->peers) {
3296 				if (xp->template != p)
3297 					continue;
3298 				session_template_clone(xp, NULL, xp->conf.id,
3299 				    xp->conf.remote_as);
3300 				if (imsg_rde(IMSG_SESSION_ADD, xp->conf.id,
3301 				    &xp->conf, sizeof(xp->conf)) == -1)
3302 					fatalx("imsg_compose error");
3303 			}
3304 		}
3305 	}
3306 
3307 	/* pfkeys of new peers already loaded by the parent process */
3308 	RB_FOREACH_SAFE(np, peer_head, &nc->peers, next) {
3309 		RB_REMOVE(peer_head, &nc->peers, np);
3310 		if (RB_INSERT(peer_head, &c->peers, np) != NULL)
3311 			fatalx("%s: peer tree is corrupt", __func__);
3312 		if (np->conf.auth.method == AUTH_MD5SIG)
3313 			tcp_md5_add_listener(c, np);
3314 	}
3315 }
3316