xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision 7d26db17)
1 /*	$KAME: rtsold.c,v 1.67 2003/05/17 18:16:15 itojun Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 #include <sys/types.h>
35 #include <sys/ioctl.h>
36 #include <sys/socket.h>
37 #include <sys/param.h>
38 
39 #include <net/if.h>
40 #include <net/if_dl.h>
41 #include <net/if_var.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/icmp6.h>
45 #include <netinet/in_var.h>
46 #include <arpa/inet.h>
47 
48 #include <netinet6/nd6.h>
49 
50 #include <signal.h>
51 #include <unistd.h>
52 #include <syslog.h>
53 #include <string.h>
54 #include <stdlib.h>
55 #include <stdio.h>
56 #include <time.h>
57 #include <errno.h>
58 #include <err.h>
59 #include <stdarg.h>
60 #include <ifaddrs.h>
61 #ifdef HAVE_POLL_H
62 #include <poll.h>
63 #endif
64 
65 #include "rtsold.h"
66 
67 #define RTSOL_DUMPFILE	"/var/run/rtsold.dump";
68 #define RTSOL_PIDFILE	"/var/run/rtsold.pid";
69 
70 struct ifinfo *iflist;
71 struct timespec tm_max;
72 static int log_upto = 999;
73 static int fflag = 0;
74 
75 int Fflag = 0;	/* force setting sysctl parameters */
76 int aflag = 0;
77 int dflag = 0;
78 int uflag = 0;
79 
80 const char *otherconf_script;
81 const char *resolvconf_script = "/sbin/resolvconf";
82 
83 /* protocol constants */
84 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
85 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
86 #define MAX_RTR_SOLICITATIONS		3 /* times */
87 
88 /*
89  * implementation dependent constants in seconds
90  * XXX: should be configurable
91  */
92 #define PROBE_INTERVAL 60
93 
94 /* static variables and functions */
95 static int mobile_node = 0;
96 static const char *pidfilename = RTSOL_PIDFILE;
97 
98 #ifndef SMALL
99 static int do_dump;
100 static const char *dumpfilename = RTSOL_DUMPFILE;
101 #endif
102 
103 #if 0
104 static int ifreconfig(char *);
105 #endif
106 
107 static int make_packet(struct ifinfo *);
108 static struct timespec *rtsol_check_timer(void);
109 
110 #ifndef SMALL
111 static void rtsold_set_dump_file(int);
112 #endif
113 static void usage(void);
114 
115 int
116 main(int argc, char **argv)
117 {
118 	int s, ch, once = 0;
119 	struct timespec *timeout;
120 	const char *opts;
121 #ifdef HAVE_POLL_H
122 	struct pollfd set[2];
123 #else
124 	fd_set *fdsetp, *selectfdp;
125 	int fdmasks;
126 	int maxfd;
127 #endif
128 	int rtsock;
129 	char *argv0;
130 
131 #ifndef SMALL
132 	/* rtsold */
133 	opts = "adDfFm1O:p:R:u";
134 #else
135 	/* rtsol */
136 	opts = "adDFO:R:u";
137 	fflag = 1;
138 	once = 1;
139 #endif
140 	argv0 = argv[0];
141 
142 	while ((ch = getopt(argc, argv, opts)) != -1) {
143 		switch (ch) {
144 		case 'a':
145 			aflag = 1;
146 			break;
147 		case 'd':
148 			dflag += 1;
149 			break;
150 		case 'D':
151 			dflag += 2;
152 			break;
153 		case 'f':
154 			fflag = 1;
155 			break;
156 		case 'F':
157 			Fflag = 1;
158 			break;
159 		case 'm':
160 			mobile_node = 1;
161 			break;
162 		case '1':
163 			once = 1;
164 			break;
165 		case 'O':
166 			otherconf_script = optarg;
167 			break;
168 		case 'p':
169 			pidfilename = optarg;
170 			break;
171 		case 'R':
172 			resolvconf_script = optarg;
173 			break;
174 		case 'u':
175 			uflag = 1;
176 			break;
177 		default:
178 			usage();
179 			exit(1);
180 		}
181 	}
182 	argc -= optind;
183 	argv += optind;
184 
185 	if ((!aflag && argc == 0) || (aflag && argc != 0)) {
186 		usage();
187 		exit(1);
188 	}
189 
190 	/* Generate maximum time in timespec. */
191 	memset(&tm_max.tv_sec, 0xff, sizeof(tm_max.tv_sec));
192 	memset(&tm_max.tv_nsec, 0xff, sizeof(tm_max.tv_nsec));
193 	tm_max.tv_sec &= ~(1UL << (sizeof(tm_max.tv_sec) * 8 - 1));
194 	tm_max.tv_nsec &= ~(1UL << (sizeof(tm_max.tv_nsec) * 8 - 1));
195 
196 	/* set log level */
197 	if (dflag > 1)
198 		log_upto = LOG_DEBUG;
199 	else if (dflag > 0)
200 		log_upto = LOG_INFO;
201 	else
202 		log_upto = LOG_NOTICE;
203 
204 	if (!fflag) {
205 		char *ident;
206 
207 		ident = strrchr(argv0, '/');
208 		if (!ident)
209 			ident = argv0;
210 		else
211 			ident++;
212 		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
213 		if (log_upto >= 0)
214 			setlogmask(LOG_UPTO(log_upto));
215 	}
216 
217 	if (otherconf_script && *otherconf_script != '/') {
218 		errx(1, "configuration script (%s) must be an absolute path",
219 		    otherconf_script);
220 	}
221 	if (resolvconf_script && *resolvconf_script != '/') {
222 		errx(1, "configuration script (%s) must be an absolute path",
223 		    resolvconf_script);
224 	}
225 	if (pidfilename && *pidfilename != '/') {
226 		errx(1, "pid filename (%s) must be an absolute path",
227 		    pidfilename);
228 	}
229 #ifndef HAVE_ARC4RANDOM
230 	/* random value initialization */
231 	srandom((u_long)time(NULL));
232 #endif
233 
234 #if (__FreeBSD_version < 900000)
235 	if (Fflag) {
236 		setinet6sysctl(IPV6CTL_FORWARDING, 0);
237 	} else {
238 		/* warn if forwarding is up */
239 		if (getinet6sysctl(IPV6CTL_FORWARDING))
240 			warnx("kernel is configured as a router, not a host");
241 	}
242 #endif
243 
244 #ifndef SMALL
245 	/* initialization to dump internal status to a file */
246 	signal(SIGUSR1, rtsold_set_dump_file);
247 #endif
248 
249 	if (!fflag)
250 		daemon(0, 0);		/* act as a daemon */
251 
252 	/*
253 	 * Open a socket for sending RS and receiving RA.
254 	 * This should be done before calling ifinit(), since the function
255 	 * uses the socket.
256 	 */
257 	if ((s = sockopen()) < 0) {
258 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
259 		exit(1);
260 	}
261 #ifdef HAVE_POLL_H
262 	set[0].fd = s;
263 	set[0].events = POLLIN;
264 #else
265 	maxfd = s;
266 #endif
267 
268 #ifdef HAVE_POLL_H
269 	set[1].fd = -1;
270 #endif
271 
272 	if ((rtsock = rtsock_open()) < 0) {
273 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
274 		exit(1);
275 	}
276 #ifdef HAVE_POLL_H
277 	set[1].fd = rtsock;
278 	set[1].events = POLLIN;
279 #else
280 	if (rtsock > maxfd)
281 		maxfd = rtsock;
282 #endif
283 
284 #ifndef HAVE_POLL_H
285 	fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask);
286 	if ((fdsetp = malloc(fdmasks)) == NULL) {
287 		warnmsg(LOG_ERR, __func__, "malloc");
288 		exit(1);
289 	}
290 	if ((selectfdp = malloc(fdmasks)) == NULL) {
291 		warnmsg(LOG_ERR, __func__, "malloc");
292 		exit(1);
293 	}
294 #endif
295 
296 	/* configuration per interface */
297 	if (ifinit()) {
298 		warnmsg(LOG_ERR, __func__,
299 		    "failed to initialize interfaces");
300 		exit(1);
301 	}
302 	if (aflag)
303 		argv = autoifprobe();
304 	while (argv && *argv) {
305 		if (ifconfig(*argv)) {
306 			warnmsg(LOG_ERR, __func__,
307 			    "failed to initialize %s", *argv);
308 			exit(1);
309 		}
310 		argv++;
311 	}
312 
313 	/* setup for probing default routers */
314 	if (probe_init()) {
315 		warnmsg(LOG_ERR, __func__,
316 		    "failed to setup for probing routers");
317 		exit(1);
318 		/*NOTREACHED*/
319 	}
320 
321 	/* dump the current pid */
322 	if (!once) {
323 		pid_t pid = getpid();
324 		FILE *fp;
325 
326 		if ((fp = fopen(pidfilename, "w")) == NULL)
327 			warnmsg(LOG_ERR, __func__,
328 			    "failed to open a pid log file(%s): %s",
329 			    pidfilename, strerror(errno));
330 		else {
331 			fprintf(fp, "%d\n", pid);
332 			fclose(fp);
333 		}
334 	}
335 #ifndef HAVE_POLL_H
336 	memset(fdsetp, 0, fdmasks);
337 	FD_SET(s, fdsetp);
338 	FD_SET(rtsock, fdsetp);
339 #endif
340 	while (1) {		/* main loop */
341 		int e;
342 
343 #ifndef HAVE_POLL_H
344 		memcpy(selectfdp, fdsetp, fdmasks);
345 #endif
346 
347 #ifndef SMALL
348 		if (do_dump) {	/* SIGUSR1 */
349 			do_dump = 0;
350 			rtsold_dump_file(dumpfilename);
351 		}
352 #endif
353 
354 		timeout = rtsol_check_timer();
355 
356 		if (once) {
357 			struct ifinfo *ifi;
358 
359 			/* if we have no timeout, we are done (or failed) */
360 			if (timeout == NULL)
361 				break;
362 
363 			/* if all interfaces have got RA packet, we are done */
364 			TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
365 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
366 					break;
367 			}
368 			if (ifi == NULL)
369 				break;
370 		}
371 #ifdef HAVE_POLL_H
372 		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM);
373 #else
374 		e = select(maxfd + 1, selectfdp, NULL, NULL, timeout);
375 #endif
376 		if (e < 1) {
377 			if (e < 0 && errno != EINTR) {
378 				warnmsg(LOG_ERR, __func__, "select: %s",
379 				    strerror(errno));
380 			}
381 			continue;
382 		}
383 
384 		/* packet reception */
385 #ifdef HAVE_POLL_H
386 		if (set[1].revents & POLLIN)
387 #else
388 		if (FD_ISSET(rtsock, selectfdp))
389 #endif
390 			rtsock_input(rtsock);
391 #ifdef HAVE_POLL_H
392 		if (set[0].revents & POLLIN)
393 #else
394 		if (FD_ISSET(s, selectfdp))
395 #endif
396 			rtsol_input(s);
397 	}
398 	/* NOTREACHED */
399 
400 	return (0);
401 }
402 
403 int
404 ifconfig(char *ifname)
405 {
406 	struct ifinfo *ifi;
407 	struct sockaddr_dl *sdl;
408 	int flags;
409 
410 	if ((sdl = if_nametosdl(ifname)) == NULL) {
411 		warnmsg(LOG_ERR, __func__,
412 		    "failed to get link layer information for %s", ifname);
413 		return (-1);
414 	}
415 	if (find_ifinfo(sdl->sdl_index)) {
416 		warnmsg(LOG_ERR, __func__,
417 		    "interface %s was already configured", ifname);
418 		free(sdl);
419 		return (-1);
420 	}
421 
422 	if (Fflag) {
423 		struct in6_ndireq nd;
424 		int s;
425 
426 		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
427 			warnmsg(LOG_ERR, __func__, "socket() failed.");
428 			return (-1);
429 		}
430 		memset(&nd, 0, sizeof(nd));
431 		strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
432 		if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
433 			warnmsg(LOG_ERR, __func__,
434 			    "cannot get accept_rtadv flag");
435 			close(s);
436 			return (-1);
437 		}
438 		nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
439 		if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
440 			warnmsg(LOG_ERR, __func__,
441 			    "cannot set accept_rtadv flag");
442 			close(s);
443 			return (-1);
444 		}
445 		close(s);
446 	}
447 
448 	if ((ifi = malloc(sizeof(*ifi))) == NULL) {
449 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
450 		free(sdl);
451 		return (-1);
452 	}
453 	memset(ifi, 0, sizeof(*ifi));
454 	ifi->sdl = sdl;
455 	ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
456 	ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
457 	TAILQ_INIT(&ifi->ifi_rainfo);
458 	strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
459 
460 	/* construct a router solicitation message */
461 	if (make_packet(ifi))
462 		goto bad;
463 
464 	/* set link ID of this interface. */
465 #ifdef HAVE_SCOPELIB
466 	if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
467 		goto bad;
468 #else
469 	/* XXX: assume interface IDs as link IDs */
470 	ifi->linkid = ifi->sdl->sdl_index;
471 #endif
472 
473 	/*
474 	 * check if the interface is available.
475 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
476 	 */
477 	ifi->mediareqok = 1;
478 	ifi->active = interface_status(ifi);
479 	if (!ifi->mediareqok) {
480 		/*
481 		 * probe routers periodically even if the link status
482 		 * does not change.
483 		 */
484 		ifi->probeinterval = PROBE_INTERVAL;
485 	}
486 
487 	/* activate interface: interface_up returns 0 on success */
488 	flags = interface_up(ifi->ifname);
489 	if (flags == 0)
490 		ifi->state = IFS_DELAY;
491 	else if (flags == IFS_TENTATIVE)
492 		ifi->state = IFS_TENTATIVE;
493 	else
494 		ifi->state = IFS_DOWN;
495 
496 	rtsol_timer_update(ifi);
497 
498 	TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
499 	return (0);
500 
501 bad:
502 	free(ifi->sdl);
503 	free(ifi);
504 	return (-1);
505 }
506 
507 void
508 iflist_init(void)
509 {
510 	struct ifinfo *ifi;
511 
512 	while ((ifi = TAILQ_FIRST(&ifinfo_head)) != NULL) {
513 		TAILQ_REMOVE(&ifinfo_head, ifi, ifi_next);
514 		if (ifi->sdl != NULL)
515 			free(ifi->sdl);
516 		if (ifi->rs_data != NULL)
517 			free(ifi->rs_data);
518 		free(ifi);
519 	}
520 }
521 
522 #if 0
523 static int
524 ifreconfig(char *ifname)
525 {
526 	struct ifinfo *ifi, *prev;
527 	int rv;
528 
529 	prev = NULL;
530 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
531 		if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
532 			break;
533 		prev = ifi;
534 	}
535 	prev->next = ifi->next;
536 
537 	rv = ifconfig(ifname);
538 
539 	/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
540 	if (ifi->rs_data)
541 		free(ifi->rs_data);
542 	free(ifi->sdl);
543 	free(ifi);
544 
545 	return (rv);
546 }
547 #endif
548 
549 struct rainfo *
550 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
551 {
552 	struct rainfo *rai;
553 
554 	TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
555 		if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
556 		    sizeof(rai->rai_saddr.sin6_addr)) == 0)
557 			return (rai);
558 
559 	return (NULL);
560 }
561 
562 struct ifinfo *
563 find_ifinfo(int ifindex)
564 {
565 	struct ifinfo *ifi;
566 
567 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
568 		if (ifi->sdl->sdl_index == ifindex)
569 			return (ifi);
570 	}
571 	return (NULL);
572 }
573 
574 static int
575 make_packet(struct ifinfo *ifi)
576 {
577 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
578 	struct nd_router_solicit *rs;
579 	char *buf;
580 
581 	if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
582 		warnmsg(LOG_INFO, __func__,
583 		    "link-layer address option has null length"
584 		    " on %s. Treat as not included.", ifi->ifname);
585 	}
586 	packlen += lladdroptlen;
587 	ifi->rs_datalen = packlen;
588 
589 	/* allocate buffer */
590 	if ((buf = malloc(packlen)) == NULL) {
591 		warnmsg(LOG_ERR, __func__,
592 		    "memory allocation failed for %s", ifi->ifname);
593 		return (-1);
594 	}
595 	ifi->rs_data = buf;
596 
597 	/* fill in the message */
598 	rs = (struct nd_router_solicit *)buf;
599 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
600 	rs->nd_rs_code = 0;
601 	rs->nd_rs_cksum = 0;
602 	rs->nd_rs_reserved = 0;
603 	buf += sizeof(*rs);
604 
605 	/* fill in source link-layer address option */
606 	if (lladdroptlen)
607 		lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
608 
609 	return (0);
610 }
611 
612 static struct timespec *
613 rtsol_check_timer(void)
614 {
615 	static struct timespec returnval;
616 	struct timespec now, rtsol_timer;
617 	struct ifinfo *ifi;
618 	struct rainfo *rai;
619 	struct ra_opt *rao;
620 	int flags;
621 
622 	clock_gettime(CLOCK_MONOTONIC_FAST, &now);
623 
624 	rtsol_timer = tm_max;
625 
626 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
627 		if (TS_CMP(&ifi->expire, &now, <=)) {
628 			warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
629 			    "state = %d", ifi->ifname, ifi->state);
630 
631 			while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
632 				/* Remove all RA options. */
633 				TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
634 				while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
635 				    NULL) {
636 					TAILQ_REMOVE(&rai->rai_ra_opt, rao,
637 					    rao_next);
638 					if (rao->rao_msg != NULL)
639 						free(rao->rao_msg);
640 					free(rao);
641 				}
642 				free(rai);
643 			}
644 			switch (ifi->state) {
645 			case IFS_DOWN:
646 			case IFS_TENTATIVE:
647 				/* interface_up returns 0 on success */
648 				flags = interface_up(ifi->ifname);
649 				if (flags == 0)
650 					ifi->state = IFS_DELAY;
651 				else if (flags == IFS_TENTATIVE)
652 					ifi->state = IFS_TENTATIVE;
653 				else
654 					ifi->state = IFS_DOWN;
655 				break;
656 			case IFS_IDLE:
657 			{
658 				int oldstatus = ifi->active;
659 				int probe = 0;
660 
661 				ifi->active = interface_status(ifi);
662 
663 				if (oldstatus != ifi->active) {
664 					warnmsg(LOG_DEBUG, __func__,
665 					    "%s status is changed"
666 					    " from %d to %d",
667 					    ifi->ifname,
668 					    oldstatus, ifi->active);
669 					probe = 1;
670 					ifi->state = IFS_DELAY;
671 				} else if (ifi->probeinterval &&
672 				    (ifi->probetimer -=
673 				    ifi->timer.tv_sec) <= 0) {
674 					/* probe timer expired */
675 					ifi->probetimer =
676 					    ifi->probeinterval;
677 					probe = 1;
678 					ifi->state = IFS_PROBE;
679 				}
680 
681 				/*
682 				 * If we need a probe, clear the previous
683 				 * status wrt the "other" configuration.
684 				 */
685 				if (probe)
686 					ifi->otherconfig = 0;
687 
688 				if (probe && mobile_node)
689 					defrouter_probe(ifi);
690 				break;
691 			}
692 			case IFS_DELAY:
693 				ifi->state = IFS_PROBE;
694 				sendpacket(ifi);
695 				break;
696 			case IFS_PROBE:
697 				if (ifi->probes < MAX_RTR_SOLICITATIONS)
698 					sendpacket(ifi);
699 				else {
700 					warnmsg(LOG_INFO, __func__,
701 					    "No answer after sending %d RSs",
702 					    ifi->probes);
703 					ifi->probes = 0;
704 					ifi->state = IFS_IDLE;
705 				}
706 				break;
707 			}
708 			rtsol_timer_update(ifi);
709 		} else {
710 			/* Expiration check for RA options. */
711 			int expire = 0;
712 
713 			TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
714 				TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
715 					warnmsg(LOG_DEBUG, __func__,
716 					    "RA expiration timer: "
717 					    "type=%d, msg=%s, expire=%s",
718 					    rao->rao_type, (char *)rao->rao_msg,
719 						sec2str(&rao->rao_expire));
720 					if (TS_CMP(&now, &rao->rao_expire,
721 					    >=)) {
722 						warnmsg(LOG_DEBUG, __func__,
723 						    "RA expiration timer: "
724 						    "expired.");
725 						TAILQ_REMOVE(&rai->rai_ra_opt,
726 						    rao, rao_next);
727 						if (rao->rao_msg != NULL)
728 							free(rao->rao_msg);
729 						free(rao);
730 						expire = 1;
731 					}
732 				}
733 			}
734 			if (expire)
735 				ra_opt_handler(ifi);
736 		}
737 		if (TS_CMP(&ifi->expire, &rtsol_timer, <))
738 			rtsol_timer = ifi->expire;
739 	}
740 
741 	if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
742 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
743 		return (NULL);
744 	} else if (TS_CMP(&rtsol_timer, &now, <))
745 		/* this may occur when the interval is too small */
746 		returnval.tv_sec = returnval.tv_nsec = 0;
747 	else
748 		TS_SUB(&rtsol_timer, &now, &returnval);
749 
750 	now.tv_sec += returnval.tv_sec;
751 	now.tv_nsec += returnval.tv_nsec;
752 	warnmsg(LOG_DEBUG, __func__, "New timer is %s",
753 	    sec2str(&now));
754 
755 	return (&returnval);
756 }
757 
758 void
759 rtsol_timer_update(struct ifinfo *ifi)
760 {
761 #define MILLION 1000000
762 #define DADRETRY 10		/* XXX: adhoc */
763 	long interval;
764 	struct timespec now;
765 
766 	bzero(&ifi->timer, sizeof(ifi->timer));
767 
768 	switch (ifi->state) {
769 	case IFS_DOWN:
770 	case IFS_TENTATIVE:
771 		if (++ifi->dadcount > DADRETRY) {
772 			ifi->dadcount = 0;
773 			ifi->timer.tv_sec = PROBE_INTERVAL;
774 		} else
775 			ifi->timer.tv_sec = 1;
776 		break;
777 	case IFS_IDLE:
778 		if (mobile_node) {
779 			/* XXX should be configurable */
780 			ifi->timer.tv_sec = 3;
781 		}
782 		else
783 			ifi->timer = tm_max;	/* stop timer(valid?) */
784 		break;
785 	case IFS_DELAY:
786 #ifndef HAVE_ARC4RANDOM
787 		interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
788 #else
789 		interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
790 #endif
791 		ifi->timer.tv_sec = interval / MILLION;
792 		ifi->timer.tv_nsec = (interval % MILLION) * 1000;
793 		break;
794 	case IFS_PROBE:
795 		if (ifi->probes < MAX_RTR_SOLICITATIONS)
796 			ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
797 		else {
798 			/*
799 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
800 			 * we're just waiting for possible replies; there
801 			 * will be no more solicitation.  Thus, we change
802 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
803 			 * on RFC 2461, Section 6.3.7.
804 			 */
805 			ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
806 		}
807 		break;
808 	default:
809 		warnmsg(LOG_ERR, __func__,
810 		    "illegal interface state(%d) on %s",
811 		    ifi->state, ifi->ifname);
812 		return;
813 	}
814 
815 	/* reset the timer */
816 	if (TS_CMP(&ifi->timer, &tm_max, ==)) {
817 		ifi->expire = tm_max;
818 		warnmsg(LOG_DEBUG, __func__,
819 		    "stop timer for %s", ifi->ifname);
820 	} else {
821 		clock_gettime(CLOCK_MONOTONIC_FAST, &now);
822 		TS_ADD(&now, &ifi->timer, &ifi->expire);
823 
824 		now.tv_sec += ifi->timer.tv_sec;
825 		now.tv_nsec += ifi->timer.tv_nsec;
826 		warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
827 		    ifi->ifname, sec2str(&now));
828 	}
829 
830 #undef MILLION
831 }
832 
833 /* timer related utility functions */
834 #define MILLION 1000000
835 
836 #ifndef SMALL
837 static void
838 rtsold_set_dump_file(int sig __unused)
839 {
840 	do_dump = 1;
841 }
842 #endif
843 
844 static void
845 usage(void)
846 {
847 #ifndef SMALL
848 	fprintf(stderr, "usage: rtsold [-adDfFm1] [-O script-name] "
849 	    "[-P pidfile] [-R script-name] interfaces...\n");
850 	fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
851 	    "[-P pidfile] [-R script-name] -a\n");
852 #else
853 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
854 	    "[-P pidfile] [-R script-name] interfaces...\n");
855 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
856 	    "[-P pidfile] [-R script-name] -a\n");
857 #endif
858 }
859 
860 void
861 warnmsg(int priority, const char *func, const char *msg, ...)
862 {
863 	va_list ap;
864 	char buf[BUFSIZ];
865 
866 	va_start(ap, msg);
867 	if (fflag) {
868 		if (priority <= log_upto) {
869 			(void)vfprintf(stderr, msg, ap);
870 			(void)fprintf(stderr, "\n");
871 		}
872 	} else {
873 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
874 		msg = buf;
875 		vsyslog(priority, msg, ap);
876 	}
877 	va_end(ap);
878 }
879 
880 /*
881  * return a list of interfaces which is suitable to sending an RS.
882  */
883 char **
884 autoifprobe(void)
885 {
886 	static char **argv = NULL;
887 	static int n = 0;
888 	char **a;
889 	int s = 0, i, found;
890 	struct ifaddrs *ifap, *ifa;
891 	struct in6_ndireq nd;
892 
893 	/* initialize */
894 	while (n--)
895 		free(argv[n]);
896 	if (argv) {
897 		free(argv);
898 		argv = NULL;
899 	}
900 	n = 0;
901 
902 	if (getifaddrs(&ifap) != 0)
903 		return (NULL);
904 
905 	if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
906 		warnmsg(LOG_ERR, __func__, "socket");
907 		exit(1);
908 	}
909 
910 	/* find an ethernet */
911 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
912 		if ((ifa->ifa_flags & IFF_UP) == 0)
913 			continue;
914 		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
915 			continue;
916 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
917 			continue;
918 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
919 			continue;
920 
921 		if (ifa->ifa_addr->sa_family != AF_INET6)
922 			continue;
923 
924 		found = 0;
925 		for (i = 0; i < n; i++) {
926 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
927 				found++;
928 				break;
929 			}
930 		}
931 		if (found)
932 			continue;
933 
934 		/*
935 		 * Skip the interfaces which IPv6 and/or accepting RA
936 		 * is disabled.
937 		 */
938 		if (!Fflag) {
939 			memset(&nd, 0, sizeof(nd));
940 			strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
941 			if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
942 				warnmsg(LOG_ERR, __func__,
943 					"ioctl(SIOCGIFINFO_IN6)");
944 				exit(1);
945 			}
946 			if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
947 				continue;
948 			if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
949 				continue;
950 		}
951 
952 		/* if we find multiple candidates, just warn. */
953 		if (n != 0 && dflag > 1)
954 			warnmsg(LOG_WARNING, __func__,
955 				"multiple interfaces found");
956 
957 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
958 		if (a == NULL) {
959 			warnmsg(LOG_ERR, __func__, "realloc");
960 			exit(1);
961 		}
962 		argv = a;
963 		argv[n] = strdup(ifa->ifa_name);
964 		if (!argv[n]) {
965 			warnmsg(LOG_ERR, __func__, "malloc");
966 			exit(1);
967 		}
968 		n++;
969 	}
970 
971 	if (n) {
972 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
973 		if (a == NULL) {
974 			warnmsg(LOG_ERR, __func__, "realloc");
975 			exit(1);
976 		}
977 		argv = a;
978 		argv[n] = NULL;
979 
980 		if (dflag > 0) {
981 			for (i = 0; i < n; i++)
982 				warnmsg(LOG_WARNING, __func__, "probing %s",
983 					argv[i]);
984 		}
985 	}
986 	if (!Fflag)
987 		close(s);
988 	freeifaddrs(ifap);
989 	return (argv);
990 }
991