xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision b740c88bfb6453416926271c089262e7164dace3)
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 
42 #include <netinet/in.h>
43 #include <netinet/icmp6.h>
44 #include <netinet/in_var.h>
45 #include <arpa/inet.h>
46 
47 #include <netinet6/nd6.h>
48 
49 #include <signal.h>
50 #include <unistd.h>
51 #include <syslog.h>
52 #include <string.h>
53 #include <stdlib.h>
54 #include <stdio.h>
55 #include <time.h>
56 #include <errno.h>
57 #include <err.h>
58 #include <stdarg.h>
59 #include <ifaddrs.h>
60 #ifdef HAVE_POLL_H
61 #include <poll.h>
62 #endif
63 
64 #include "rtsold.h"
65 
66 #define RTSOL_DUMPFILE	"/var/run/rtsold.dump";
67 #define RTSOL_PIDFILE	"/var/run/rtsold.pid";
68 
69 struct timespec tm_max;
70 static int log_upto = 999;
71 static int fflag = 0;
72 
73 int Fflag = 0;	/* force setting sysctl parameters */
74 int aflag = 0;
75 int dflag = 0;
76 int uflag = 0;
77 
78 const char *otherconf_script;
79 const char *resolvconf_script = "/sbin/resolvconf";
80 
81 /* protocol constants */
82 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
83 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
84 #define MAX_RTR_SOLICITATIONS		3 /* times */
85 
86 /*
87  * implementation dependent constants in seconds
88  * XXX: should be configurable
89  */
90 #define PROBE_INTERVAL 60
91 
92 /* static variables and functions */
93 static int mobile_node = 0;
94 static const char *pidfilename = RTSOL_PIDFILE;
95 
96 #ifndef SMALL
97 static int do_dump;
98 static const char *dumpfilename = RTSOL_DUMPFILE;
99 #endif
100 
101 #if 0
102 static int ifreconfig(char *);
103 #endif
104 
105 static int make_packet(struct ifinfo *);
106 static struct timespec *rtsol_check_timer(void);
107 
108 #ifndef SMALL
109 static void rtsold_set_dump_file(int);
110 #endif
111 static void usage(void);
112 
113 int
114 main(int argc, char **argv)
115 {
116 	int s, ch, once = 0;
117 	struct timespec *timeout;
118 	const char *opts;
119 #ifdef HAVE_POLL_H
120 	struct pollfd set[2];
121 #else
122 	fd_set *fdsetp, *selectfdp;
123 	int fdmasks;
124 	int maxfd;
125 #endif
126 	int rtsock;
127 	char *argv0;
128 
129 #ifndef SMALL
130 	/* rtsold */
131 	opts = "adDfFm1O:p:R:u";
132 #else
133 	/* rtsol */
134 	opts = "adDFO:R:u";
135 	fflag = 1;
136 	once = 1;
137 #endif
138 	argv0 = argv[0];
139 
140 	while ((ch = getopt(argc, argv, opts)) != -1) {
141 		switch (ch) {
142 		case 'a':
143 			aflag = 1;
144 			break;
145 		case 'd':
146 			dflag += 1;
147 			break;
148 		case 'D':
149 			dflag += 2;
150 			break;
151 		case 'f':
152 			fflag = 1;
153 			break;
154 		case 'F':
155 			Fflag = 1;
156 			break;
157 		case 'm':
158 			mobile_node = 1;
159 			break;
160 		case '1':
161 			once = 1;
162 			break;
163 		case 'O':
164 			otherconf_script = optarg;
165 			break;
166 		case 'p':
167 			pidfilename = optarg;
168 			break;
169 		case 'R':
170 			resolvconf_script = optarg;
171 			break;
172 		case 'u':
173 			uflag = 1;
174 			break;
175 		default:
176 			usage();
177 			exit(1);
178 		}
179 	}
180 	argc -= optind;
181 	argv += optind;
182 
183 	if ((!aflag && argc == 0) || (aflag && argc != 0)) {
184 		usage();
185 		exit(1);
186 	}
187 
188 	/* Generate maximum time in timespec. */
189 	tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1));
190 	tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1));
191 
192 	/* set log level */
193 	if (dflag > 1)
194 		log_upto = LOG_DEBUG;
195 	else if (dflag > 0)
196 		log_upto = LOG_INFO;
197 	else
198 		log_upto = LOG_NOTICE;
199 
200 	if (!fflag) {
201 		char *ident;
202 
203 		ident = strrchr(argv0, '/');
204 		if (!ident)
205 			ident = argv0;
206 		else
207 			ident++;
208 		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
209 		if (log_upto >= 0)
210 			setlogmask(LOG_UPTO(log_upto));
211 	}
212 
213 	if (otherconf_script && *otherconf_script != '/') {
214 		errx(1, "configuration script (%s) must be an absolute path",
215 		    otherconf_script);
216 	}
217 	if (resolvconf_script && *resolvconf_script != '/') {
218 		errx(1, "configuration script (%s) must be an absolute path",
219 		    resolvconf_script);
220 	}
221 	if (pidfilename && *pidfilename != '/') {
222 		errx(1, "pid filename (%s) must be an absolute path",
223 		    pidfilename);
224 	}
225 #ifndef HAVE_ARC4RANDOM
226 	/* random value initialization */
227 	srandom((u_long)time(NULL));
228 #endif
229 
230 #if (__FreeBSD_version < 900000)
231 	if (Fflag) {
232 		setinet6sysctl(IPV6CTL_FORWARDING, 0);
233 	} else {
234 		/* warn if forwarding is up */
235 		if (getinet6sysctl(IPV6CTL_FORWARDING))
236 			warnx("kernel is configured as a router, not a host");
237 	}
238 #endif
239 
240 #ifndef SMALL
241 	/* initialization to dump internal status to a file */
242 	signal(SIGUSR1, rtsold_set_dump_file);
243 #endif
244 
245 	if (!fflag)
246 		daemon(0, 0);		/* act as a daemon */
247 
248 	/*
249 	 * Open a socket for sending RS and receiving RA.
250 	 * This should be done before calling ifinit(), since the function
251 	 * uses the socket.
252 	 */
253 	if ((s = sockopen()) < 0) {
254 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
255 		exit(1);
256 	}
257 #ifdef HAVE_POLL_H
258 	set[0].fd = s;
259 	set[0].events = POLLIN;
260 #else
261 	maxfd = s;
262 #endif
263 
264 #ifdef HAVE_POLL_H
265 	set[1].fd = -1;
266 #endif
267 
268 	if ((rtsock = rtsock_open()) < 0) {
269 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
270 		exit(1);
271 	}
272 #ifdef HAVE_POLL_H
273 	set[1].fd = rtsock;
274 	set[1].events = POLLIN;
275 #else
276 	if (rtsock > maxfd)
277 		maxfd = rtsock;
278 #endif
279 
280 #ifndef HAVE_POLL_H
281 	fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask);
282 	if ((fdsetp = malloc(fdmasks)) == NULL) {
283 		warnmsg(LOG_ERR, __func__, "malloc");
284 		exit(1);
285 	}
286 	if ((selectfdp = malloc(fdmasks)) == NULL) {
287 		warnmsg(LOG_ERR, __func__, "malloc");
288 		exit(1);
289 	}
290 #endif
291 
292 	/* configuration per interface */
293 	if (ifinit()) {
294 		warnmsg(LOG_ERR, __func__,
295 		    "failed to initialize interfaces");
296 		exit(1);
297 	}
298 	if (aflag)
299 		argv = autoifprobe();
300 	while (argv && *argv) {
301 		if (ifconfig(*argv)) {
302 			warnmsg(LOG_ERR, __func__,
303 			    "failed to initialize %s", *argv);
304 			exit(1);
305 		}
306 		argv++;
307 	}
308 
309 	/* setup for probing default routers */
310 	if (probe_init()) {
311 		warnmsg(LOG_ERR, __func__,
312 		    "failed to setup for probing routers");
313 		exit(1);
314 		/*NOTREACHED*/
315 	}
316 
317 	/* dump the current pid */
318 	if (!once) {
319 		pid_t pid = getpid();
320 		FILE *fp;
321 
322 		if ((fp = fopen(pidfilename, "w")) == NULL)
323 			warnmsg(LOG_ERR, __func__,
324 			    "failed to open a pid log file(%s): %s",
325 			    pidfilename, strerror(errno));
326 		else {
327 			fprintf(fp, "%d\n", pid);
328 			fclose(fp);
329 		}
330 	}
331 #ifndef HAVE_POLL_H
332 	memset(fdsetp, 0, fdmasks);
333 	FD_SET(s, fdsetp);
334 	FD_SET(rtsock, fdsetp);
335 #endif
336 	while (1) {		/* main loop */
337 		int e;
338 
339 #ifndef HAVE_POLL_H
340 		memcpy(selectfdp, fdsetp, fdmasks);
341 #endif
342 
343 #ifndef SMALL
344 		if (do_dump) {	/* SIGUSR1 */
345 			do_dump = 0;
346 			rtsold_dump_file(dumpfilename);
347 		}
348 #endif
349 
350 		timeout = rtsol_check_timer();
351 
352 		if (once) {
353 			struct ifinfo *ifi;
354 
355 			/* if we have no timeout, we are done (or failed) */
356 			if (timeout == NULL)
357 				break;
358 
359 			/* if all interfaces have got RA packet, we are done */
360 			TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
361 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
362 					break;
363 			}
364 			if (ifi == NULL)
365 				break;
366 		}
367 #ifdef HAVE_POLL_H
368 		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM);
369 #else
370 		e = select(maxfd + 1, selectfdp, NULL, NULL, timeout);
371 #endif
372 		if (e < 1) {
373 			if (e < 0 && errno != EINTR) {
374 				warnmsg(LOG_ERR, __func__, "select: %s",
375 				    strerror(errno));
376 			}
377 			continue;
378 		}
379 
380 		/* packet reception */
381 #ifdef HAVE_POLL_H
382 		if (set[1].revents & POLLIN)
383 #else
384 		if (FD_ISSET(rtsock, selectfdp))
385 #endif
386 			rtsock_input(rtsock);
387 #ifdef HAVE_POLL_H
388 		if (set[0].revents & POLLIN)
389 #else
390 		if (FD_ISSET(s, selectfdp))
391 #endif
392 			rtsol_input(s);
393 	}
394 	/* NOTREACHED */
395 
396 	return (0);
397 }
398 
399 int
400 ifconfig(char *ifname)
401 {
402 	struct ifinfo *ifi;
403 	struct sockaddr_dl *sdl;
404 	int flags;
405 
406 	if ((sdl = if_nametosdl(ifname)) == NULL) {
407 		warnmsg(LOG_ERR, __func__,
408 		    "failed to get link layer information for %s", ifname);
409 		return (-1);
410 	}
411 	if (find_ifinfo(sdl->sdl_index)) {
412 		warnmsg(LOG_ERR, __func__,
413 		    "interface %s was already configured", ifname);
414 		free(sdl);
415 		return (-1);
416 	}
417 
418 	if (Fflag) {
419 		struct in6_ndireq nd;
420 		int s;
421 
422 		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
423 			warnmsg(LOG_ERR, __func__, "socket() failed.");
424 			return (-1);
425 		}
426 		memset(&nd, 0, sizeof(nd));
427 		strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
428 		if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
429 			warnmsg(LOG_ERR, __func__,
430 			    "cannot get accept_rtadv flag");
431 			close(s);
432 			return (-1);
433 		}
434 		nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
435 		if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
436 			warnmsg(LOG_ERR, __func__,
437 			    "cannot set accept_rtadv flag");
438 			close(s);
439 			return (-1);
440 		}
441 		close(s);
442 	}
443 
444 	if ((ifi = malloc(sizeof(*ifi))) == NULL) {
445 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
446 		free(sdl);
447 		return (-1);
448 	}
449 	memset(ifi, 0, sizeof(*ifi));
450 	ifi->sdl = sdl;
451 	ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
452 	ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
453 	TAILQ_INIT(&ifi->ifi_rainfo);
454 	strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
455 
456 	/* construct a router solicitation message */
457 	if (make_packet(ifi))
458 		goto bad;
459 
460 	/* set link ID of this interface. */
461 #ifdef HAVE_SCOPELIB
462 	if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
463 		goto bad;
464 #else
465 	/* XXX: assume interface IDs as link IDs */
466 	ifi->linkid = ifi->sdl->sdl_index;
467 #endif
468 
469 	/*
470 	 * check if the interface is available.
471 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
472 	 */
473 	ifi->mediareqok = 1;
474 	ifi->active = interface_status(ifi);
475 	if (!ifi->mediareqok) {
476 		/*
477 		 * probe routers periodically even if the link status
478 		 * does not change.
479 		 */
480 		ifi->probeinterval = PROBE_INTERVAL;
481 	}
482 
483 	/* activate interface: interface_up returns 0 on success */
484 	flags = interface_up(ifi->ifname);
485 	if (flags == 0)
486 		ifi->state = IFS_DELAY;
487 	else if (flags == IFS_TENTATIVE)
488 		ifi->state = IFS_TENTATIVE;
489 	else
490 		ifi->state = IFS_DOWN;
491 
492 	rtsol_timer_update(ifi);
493 
494 	TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
495 	return (0);
496 
497 bad:
498 	free(ifi->sdl);
499 	free(ifi);
500 	return (-1);
501 }
502 
503 void
504 iflist_init(void)
505 {
506 	struct ifinfo *ifi;
507 
508 	while ((ifi = TAILQ_FIRST(&ifinfo_head)) != NULL) {
509 		TAILQ_REMOVE(&ifinfo_head, ifi, ifi_next);
510 		if (ifi->sdl != NULL)
511 			free(ifi->sdl);
512 		if (ifi->rs_data != NULL)
513 			free(ifi->rs_data);
514 		free(ifi);
515 	}
516 }
517 
518 #if 0
519 static int
520 ifreconfig(char *ifname)
521 {
522 	struct ifinfo *ifi, *prev;
523 	int rv;
524 
525 	prev = NULL;
526 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
527 		if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
528 			break;
529 		prev = ifi;
530 	}
531 	prev->next = ifi->next;
532 
533 	rv = ifconfig(ifname);
534 
535 	/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
536 	if (ifi->rs_data)
537 		free(ifi->rs_data);
538 	free(ifi->sdl);
539 	free(ifi);
540 
541 	return (rv);
542 }
543 #endif
544 
545 struct rainfo *
546 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
547 {
548 	struct rainfo *rai;
549 
550 	TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
551 		if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
552 		    sizeof(rai->rai_saddr.sin6_addr)) == 0)
553 			return (rai);
554 
555 	return (NULL);
556 }
557 
558 struct ifinfo *
559 find_ifinfo(int ifindex)
560 {
561 	struct ifinfo *ifi;
562 
563 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
564 		if (ifi->sdl->sdl_index == ifindex)
565 			return (ifi);
566 	}
567 	return (NULL);
568 }
569 
570 static int
571 make_packet(struct ifinfo *ifi)
572 {
573 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
574 	struct nd_router_solicit *rs;
575 	char *buf;
576 
577 	if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
578 		warnmsg(LOG_INFO, __func__,
579 		    "link-layer address option has null length"
580 		    " on %s. Treat as not included.", ifi->ifname);
581 	}
582 	packlen += lladdroptlen;
583 	ifi->rs_datalen = packlen;
584 
585 	/* allocate buffer */
586 	if ((buf = malloc(packlen)) == NULL) {
587 		warnmsg(LOG_ERR, __func__,
588 		    "memory allocation failed for %s", ifi->ifname);
589 		return (-1);
590 	}
591 	ifi->rs_data = buf;
592 
593 	/* fill in the message */
594 	rs = (struct nd_router_solicit *)buf;
595 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
596 	rs->nd_rs_code = 0;
597 	rs->nd_rs_cksum = 0;
598 	rs->nd_rs_reserved = 0;
599 	buf += sizeof(*rs);
600 
601 	/* fill in source link-layer address option */
602 	if (lladdroptlen)
603 		lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
604 
605 	return (0);
606 }
607 
608 static struct timespec *
609 rtsol_check_timer(void)
610 {
611 	static struct timespec returnval;
612 	struct timespec now, rtsol_timer;
613 	struct ifinfo *ifi;
614 	struct rainfo *rai;
615 	struct ra_opt *rao;
616 	int flags;
617 
618 	clock_gettime(CLOCK_MONOTONIC_FAST, &now);
619 
620 	rtsol_timer = tm_max;
621 
622 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
623 		if (TS_CMP(&ifi->expire, &now, <=)) {
624 			warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
625 			    "state = %d", ifi->ifname, ifi->state);
626 
627 			while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
628 				/* Remove all RA options. */
629 				TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
630 				while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
631 				    NULL) {
632 					TAILQ_REMOVE(&rai->rai_ra_opt, rao,
633 					    rao_next);
634 					if (rao->rao_msg != NULL)
635 						free(rao->rao_msg);
636 					free(rao);
637 				}
638 				free(rai);
639 			}
640 			switch (ifi->state) {
641 			case IFS_DOWN:
642 			case IFS_TENTATIVE:
643 				/* interface_up returns 0 on success */
644 				flags = interface_up(ifi->ifname);
645 				if (flags == 0)
646 					ifi->state = IFS_DELAY;
647 				else if (flags == IFS_TENTATIVE)
648 					ifi->state = IFS_TENTATIVE;
649 				else
650 					ifi->state = IFS_DOWN;
651 				break;
652 			case IFS_IDLE:
653 			{
654 				int oldstatus = ifi->active;
655 				int probe = 0;
656 
657 				ifi->active = interface_status(ifi);
658 
659 				if (oldstatus != ifi->active) {
660 					warnmsg(LOG_DEBUG, __func__,
661 					    "%s status is changed"
662 					    " from %d to %d",
663 					    ifi->ifname,
664 					    oldstatus, ifi->active);
665 					probe = 1;
666 					ifi->state = IFS_DELAY;
667 				} else if (ifi->probeinterval &&
668 				    (ifi->probetimer -=
669 				    ifi->timer.tv_sec) <= 0) {
670 					/* probe timer expired */
671 					ifi->probetimer =
672 					    ifi->probeinterval;
673 					probe = 1;
674 					ifi->state = IFS_PROBE;
675 				}
676 
677 				/*
678 				 * If we need a probe, clear the previous
679 				 * status wrt the "other" configuration.
680 				 */
681 				if (probe)
682 					ifi->otherconfig = 0;
683 
684 				if (probe && mobile_node)
685 					defrouter_probe(ifi);
686 				break;
687 			}
688 			case IFS_DELAY:
689 				ifi->state = IFS_PROBE;
690 				sendpacket(ifi);
691 				break;
692 			case IFS_PROBE:
693 				if (ifi->probes < MAX_RTR_SOLICITATIONS)
694 					sendpacket(ifi);
695 				else {
696 					warnmsg(LOG_INFO, __func__,
697 					    "No answer after sending %d RSs",
698 					    ifi->probes);
699 					ifi->probes = 0;
700 					ifi->state = IFS_IDLE;
701 				}
702 				break;
703 			}
704 			rtsol_timer_update(ifi);
705 		} else {
706 			/* Expiration check for RA options. */
707 			int expire = 0;
708 
709 			TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
710 				TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
711 					warnmsg(LOG_DEBUG, __func__,
712 					    "RA expiration timer: "
713 					    "type=%d, msg=%s, expire=%s",
714 					    rao->rao_type, (char *)rao->rao_msg,
715 						sec2str(&rao->rao_expire));
716 					if (TS_CMP(&now, &rao->rao_expire,
717 					    >=)) {
718 						warnmsg(LOG_DEBUG, __func__,
719 						    "RA expiration timer: "
720 						    "expired.");
721 						TAILQ_REMOVE(&rai->rai_ra_opt,
722 						    rao, rao_next);
723 						if (rao->rao_msg != NULL)
724 							free(rao->rao_msg);
725 						free(rao);
726 						expire = 1;
727 					}
728 				}
729 			}
730 			if (expire)
731 				ra_opt_handler(ifi);
732 		}
733 		if (TS_CMP(&ifi->expire, &rtsol_timer, <))
734 			rtsol_timer = ifi->expire;
735 	}
736 
737 	if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
738 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
739 		return (NULL);
740 	} else if (TS_CMP(&rtsol_timer, &now, <))
741 		/* this may occur when the interval is too small */
742 		returnval.tv_sec = returnval.tv_nsec = 0;
743 	else
744 		TS_SUB(&rtsol_timer, &now, &returnval);
745 
746 	now.tv_sec += returnval.tv_sec;
747 	now.tv_nsec += returnval.tv_nsec;
748 	warnmsg(LOG_DEBUG, __func__, "New timer is %s",
749 	    sec2str(&now));
750 
751 	return (&returnval);
752 }
753 
754 void
755 rtsol_timer_update(struct ifinfo *ifi)
756 {
757 #define MILLION 1000000
758 #define DADRETRY 10		/* XXX: adhoc */
759 	long interval;
760 	struct timespec now;
761 
762 	bzero(&ifi->timer, sizeof(ifi->timer));
763 
764 	switch (ifi->state) {
765 	case IFS_DOWN:
766 	case IFS_TENTATIVE:
767 		if (++ifi->dadcount > DADRETRY) {
768 			ifi->dadcount = 0;
769 			ifi->timer.tv_sec = PROBE_INTERVAL;
770 		} else
771 			ifi->timer.tv_sec = 1;
772 		break;
773 	case IFS_IDLE:
774 		if (mobile_node) {
775 			/* XXX should be configurable */
776 			ifi->timer.tv_sec = 3;
777 		}
778 		else
779 			ifi->timer = tm_max;	/* stop timer(valid?) */
780 		break;
781 	case IFS_DELAY:
782 #ifndef HAVE_ARC4RANDOM
783 		interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
784 #else
785 		interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
786 #endif
787 		ifi->timer.tv_sec = interval / MILLION;
788 		ifi->timer.tv_nsec = (interval % MILLION) * 1000;
789 		break;
790 	case IFS_PROBE:
791 		if (ifi->probes < MAX_RTR_SOLICITATIONS)
792 			ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
793 		else {
794 			/*
795 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
796 			 * we're just waiting for possible replies; there
797 			 * will be no more solicitation.  Thus, we change
798 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
799 			 * on RFC 2461, Section 6.3.7.
800 			 */
801 			ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
802 		}
803 		break;
804 	default:
805 		warnmsg(LOG_ERR, __func__,
806 		    "illegal interface state(%d) on %s",
807 		    ifi->state, ifi->ifname);
808 		return;
809 	}
810 
811 	/* reset the timer */
812 	if (TS_CMP(&ifi->timer, &tm_max, ==)) {
813 		ifi->expire = tm_max;
814 		warnmsg(LOG_DEBUG, __func__,
815 		    "stop timer for %s", ifi->ifname);
816 	} else {
817 		clock_gettime(CLOCK_MONOTONIC_FAST, &now);
818 		TS_ADD(&now, &ifi->timer, &ifi->expire);
819 
820 		now.tv_sec += ifi->timer.tv_sec;
821 		now.tv_nsec += ifi->timer.tv_nsec;
822 		warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
823 		    ifi->ifname, sec2str(&now));
824 	}
825 
826 #undef MILLION
827 }
828 
829 /* timer related utility functions */
830 #define MILLION 1000000
831 
832 #ifndef SMALL
833 static void
834 rtsold_set_dump_file(int sig __unused)
835 {
836 	do_dump = 1;
837 }
838 #endif
839 
840 static void
841 usage(void)
842 {
843 #ifndef SMALL
844 	fprintf(stderr, "usage: rtsold [-adDfFm1] [-O script-name] "
845 	    "[-P pidfile] [-R script-name] interfaces...\n");
846 	fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
847 	    "[-P pidfile] [-R script-name] -a\n");
848 #else
849 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
850 	    "[-P pidfile] [-R script-name] interfaces...\n");
851 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
852 	    "[-P pidfile] [-R script-name] -a\n");
853 #endif
854 }
855 
856 void
857 warnmsg(int priority, const char *func, const char *msg, ...)
858 {
859 	va_list ap;
860 	char buf[BUFSIZ];
861 
862 	va_start(ap, msg);
863 	if (fflag) {
864 		if (priority <= log_upto) {
865 			(void)vfprintf(stderr, msg, ap);
866 			(void)fprintf(stderr, "\n");
867 		}
868 	} else {
869 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
870 		msg = buf;
871 		vsyslog(priority, msg, ap);
872 	}
873 	va_end(ap);
874 }
875 
876 /*
877  * return a list of interfaces which is suitable to sending an RS.
878  */
879 char **
880 autoifprobe(void)
881 {
882 	static char **argv = NULL;
883 	static int n = 0;
884 	char **a;
885 	int s = 0, i, found;
886 	struct ifaddrs *ifap, *ifa;
887 	struct in6_ndireq nd;
888 
889 	/* initialize */
890 	while (n--)
891 		free(argv[n]);
892 	if (argv) {
893 		free(argv);
894 		argv = NULL;
895 	}
896 	n = 0;
897 
898 	if (getifaddrs(&ifap) != 0)
899 		return (NULL);
900 
901 	if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
902 		warnmsg(LOG_ERR, __func__, "socket");
903 		exit(1);
904 	}
905 
906 	/* find an ethernet */
907 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
908 		if ((ifa->ifa_flags & IFF_UP) == 0)
909 			continue;
910 		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
911 			continue;
912 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
913 			continue;
914 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
915 			continue;
916 
917 		if (ifa->ifa_addr->sa_family != AF_INET6)
918 			continue;
919 
920 		found = 0;
921 		for (i = 0; i < n; i++) {
922 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
923 				found++;
924 				break;
925 			}
926 		}
927 		if (found)
928 			continue;
929 
930 		/*
931 		 * Skip the interfaces which IPv6 and/or accepting RA
932 		 * is disabled.
933 		 */
934 		if (!Fflag) {
935 			memset(&nd, 0, sizeof(nd));
936 			strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
937 			if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
938 				warnmsg(LOG_ERR, __func__,
939 					"ioctl(SIOCGIFINFO_IN6)");
940 				exit(1);
941 			}
942 			if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
943 				continue;
944 			if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
945 				continue;
946 		}
947 
948 		/* if we find multiple candidates, just warn. */
949 		if (n != 0 && dflag > 1)
950 			warnmsg(LOG_WARNING, __func__,
951 				"multiple interfaces found");
952 
953 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
954 		if (a == NULL) {
955 			warnmsg(LOG_ERR, __func__, "realloc");
956 			exit(1);
957 		}
958 		argv = a;
959 		argv[n] = strdup(ifa->ifa_name);
960 		if (!argv[n]) {
961 			warnmsg(LOG_ERR, __func__, "malloc");
962 			exit(1);
963 		}
964 		n++;
965 	}
966 
967 	if (n) {
968 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
969 		if (a == NULL) {
970 			warnmsg(LOG_ERR, __func__, "realloc");
971 			exit(1);
972 		}
973 		argv = a;
974 		argv[n] = NULL;
975 
976 		if (dflag > 0) {
977 			for (i = 0; i < n; i++)
978 				warnmsg(LOG_WARNING, __func__, "probing %s",
979 					argv[i]);
980 		}
981 	}
982 	if (!Fflag)
983 		close(s);
984 	freeifaddrs(ifap);
985 	return (argv);
986 }
987