xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision 7815283df299be63807225a9fe9b6e54406eae28)
1 /*	$KAME: rtsold.c,v 1.67 2003/05/17 18:16:15 itojun Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD$
34  */
35 
36 #include <sys/param.h>
37 #include <sys/ioctl.h>
38 #include <sys/socket.h>
39 
40 #include <net/if.h>
41 #include <net/if_dl.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 #include <poll.h>
62 
63 #include "rtsold.h"
64 
65 #define RTSOL_DUMPFILE	"/var/run/rtsold.dump";
66 #define RTSOL_PIDFILE	"/var/run/rtsold.pid";
67 
68 struct timespec tm_max;
69 static int log_upto = 999;
70 static int fflag = 0;
71 
72 int Fflag = 0;	/* force setting sysctl parameters */
73 int aflag = 0;
74 int dflag = 0;
75 int uflag = 0;
76 
77 const char *otherconf_script;
78 const char *resolvconf_script = "/sbin/resolvconf";
79 
80 /* protocol constants */
81 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
82 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
83 #define MAX_RTR_SOLICITATIONS		3 /* times */
84 
85 /*
86  * implementation dependent constants in seconds
87  * XXX: should be configurable
88  */
89 #define PROBE_INTERVAL 60
90 
91 /* static variables and functions */
92 static int mobile_node = 0;
93 static const char *pidfilename = RTSOL_PIDFILE;
94 
95 #ifndef SMALL
96 static int do_dump;
97 static const char *dumpfilename = RTSOL_DUMPFILE;
98 #endif
99 
100 static char **autoifprobe(void);
101 static int ifconfig(char *ifname);
102 static int make_packet(struct ifinfo *);
103 static struct timespec *rtsol_check_timer(void);
104 
105 #ifndef SMALL
106 static void rtsold_set_dump_file(int);
107 #endif
108 static void usage(void);
109 
110 int
111 main(int argc, char **argv)
112 {
113 	int s, ch, once = 0;
114 	struct timespec *timeout;
115 	const char *opts;
116 	struct pollfd set[2];
117 	int rtsock;
118 	char *argv0;
119 
120 #ifndef SMALL
121 	/* rtsold */
122 	opts = "adDfFm1O:p:R:u";
123 #else
124 	/* rtsol */
125 	opts = "adDFO:R:u";
126 	fflag = 1;
127 	once = 1;
128 #endif
129 	argv0 = argv[0];
130 
131 	while ((ch = getopt(argc, argv, opts)) != -1) {
132 		switch (ch) {
133 		case 'a':
134 			aflag = 1;
135 			break;
136 		case 'd':
137 			dflag += 1;
138 			break;
139 		case 'D':
140 			dflag += 2;
141 			break;
142 		case 'f':
143 			fflag = 1;
144 			break;
145 		case 'F':
146 			Fflag = 1;
147 			break;
148 		case 'm':
149 			mobile_node = 1;
150 			break;
151 		case '1':
152 			once = 1;
153 			break;
154 		case 'O':
155 			otherconf_script = optarg;
156 			break;
157 		case 'p':
158 			pidfilename = optarg;
159 			break;
160 		case 'R':
161 			resolvconf_script = optarg;
162 			break;
163 		case 'u':
164 			uflag = 1;
165 			break;
166 		default:
167 			usage();
168 			exit(1);
169 		}
170 	}
171 	argc -= optind;
172 	argv += optind;
173 
174 	if ((!aflag && argc == 0) || (aflag && argc != 0)) {
175 		usage();
176 		exit(1);
177 	}
178 
179 	/* Generate maximum time in timespec. */
180 	tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1));
181 	tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1));
182 
183 	/* set log level */
184 	if (dflag > 1)
185 		log_upto = LOG_DEBUG;
186 	else if (dflag > 0)
187 		log_upto = LOG_INFO;
188 	else
189 		log_upto = LOG_NOTICE;
190 
191 	if (!fflag) {
192 		char *ident;
193 
194 		ident = strrchr(argv0, '/');
195 		if (!ident)
196 			ident = argv0;
197 		else
198 			ident++;
199 		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
200 		if (log_upto >= 0)
201 			setlogmask(LOG_UPTO(log_upto));
202 	}
203 
204 	if (otherconf_script && *otherconf_script != '/') {
205 		errx(1, "configuration script (%s) must be an absolute path",
206 		    otherconf_script);
207 	}
208 	if (resolvconf_script && *resolvconf_script != '/') {
209 		errx(1, "configuration script (%s) must be an absolute path",
210 		    resolvconf_script);
211 	}
212 	if (pidfilename && *pidfilename != '/') {
213 		errx(1, "pid filename (%s) must be an absolute path",
214 		    pidfilename);
215 	}
216 
217 #ifndef SMALL
218 	/* initialization to dump internal status to a file */
219 	signal(SIGUSR1, rtsold_set_dump_file);
220 #endif
221 
222 	if (!fflag)
223 		daemon(0, 0);		/* act as a daemon */
224 
225 	/*
226 	 * Open a socket for sending RS and receiving RA.
227 	 * This should be done before calling ifinit(), since the function
228 	 * uses the socket.
229 	 */
230 	if ((s = sockopen()) < 0) {
231 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
232 		exit(1);
233 	}
234 	set[0].fd = s;
235 	set[0].events = POLLIN;
236 	set[1].fd = -1;
237 
238 	if ((rtsock = rtsock_open()) < 0) {
239 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
240 		exit(1);
241 	}
242 	set[1].fd = rtsock;
243 	set[1].events = POLLIN;
244 
245 	/* configuration per interface */
246 	if (ifinit()) {
247 		warnmsg(LOG_ERR, __func__,
248 		    "failed to initialize interfaces");
249 		exit(1);
250 	}
251 	if (aflag)
252 		argv = autoifprobe();
253 	while (argv && *argv) {
254 		if (ifconfig(*argv)) {
255 			warnmsg(LOG_ERR, __func__,
256 			    "failed to initialize %s", *argv);
257 			exit(1);
258 		}
259 		argv++;
260 	}
261 
262 	/* setup for probing default routers */
263 	if (probe_init()) {
264 		warnmsg(LOG_ERR, __func__,
265 		    "failed to setup for probing routers");
266 		exit(1);
267 		/*NOTREACHED*/
268 	}
269 
270 	/* dump the current pid */
271 	if (!once) {
272 		pid_t pid = getpid();
273 		FILE *fp;
274 
275 		if ((fp = fopen(pidfilename, "w")) == NULL)
276 			warnmsg(LOG_ERR, __func__,
277 			    "failed to open a pid log file(%s): %s",
278 			    pidfilename, strerror(errno));
279 		else {
280 			fprintf(fp, "%d\n", pid);
281 			fclose(fp);
282 		}
283 	}
284 	while (1) {		/* main loop */
285 		int e;
286 #ifndef SMALL
287 		if (do_dump) {	/* SIGUSR1 */
288 			do_dump = 0;
289 			rtsold_dump_file(dumpfilename);
290 		}
291 #endif
292 
293 		timeout = rtsol_check_timer();
294 
295 		if (once) {
296 			struct ifinfo *ifi;
297 
298 			/* if we have no timeout, we are done (or failed) */
299 			if (timeout == NULL)
300 				break;
301 
302 			/* if all interfaces have got RA packet, we are done */
303 			TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
304 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
305 					break;
306 			}
307 			if (ifi == NULL)
308 				break;
309 		}
310 		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM);
311 		if (e < 1) {
312 			if (e < 0 && errno != EINTR) {
313 				warnmsg(LOG_ERR, __func__, "select: %s",
314 				    strerror(errno));
315 			}
316 			continue;
317 		}
318 
319 		/* packet reception */
320 		if (set[1].revents & POLLIN)
321 			rtsock_input(rtsock);
322 		if (set[0].revents & POLLIN)
323 			rtsol_input(s);
324 	}
325 	/* NOTREACHED */
326 
327 	return (0);
328 }
329 
330 static int
331 ifconfig(char *ifname)
332 {
333 	struct ifinfo *ifi;
334 	struct sockaddr_dl *sdl;
335 	int flags;
336 
337 	ifi = NULL;
338 	if ((sdl = if_nametosdl(ifname)) == NULL) {
339 		warnmsg(LOG_ERR, __func__,
340 		    "failed to get link layer information for %s", ifname);
341 		goto bad;
342 	}
343 	if (find_ifinfo(sdl->sdl_index)) {
344 		warnmsg(LOG_ERR, __func__,
345 		    "interface %s was already configured", ifname);
346 		goto bad;
347 	}
348 
349 	if (Fflag) {
350 		struct in6_ndireq nd;
351 		int s;
352 
353 		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
354 			warnmsg(LOG_ERR, __func__, "socket() failed.");
355 			goto bad;
356 		}
357 		memset(&nd, 0, sizeof(nd));
358 		strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
359 		if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
360 			warnmsg(LOG_ERR, __func__,
361 			    "cannot get accept_rtadv flag");
362 			(void)close(s);
363 			goto bad;
364 		}
365 		nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
366 		if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
367 			warnmsg(LOG_ERR, __func__,
368 			    "cannot set accept_rtadv flag");
369 			(void)close(s);
370 			goto bad;
371 		}
372 		(void)close(s);
373 	}
374 
375 	if ((ifi = malloc(sizeof(*ifi))) == NULL) {
376 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
377 		goto bad;
378 	}
379 	memset(ifi, 0, sizeof(*ifi));
380 	ifi->sdl = sdl;
381 	ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
382 	ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
383 	TAILQ_INIT(&ifi->ifi_rainfo);
384 	strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
385 
386 	/* construct a router solicitation message */
387 	if (make_packet(ifi))
388 		goto bad;
389 
390 	/* set link ID of this interface. */
391 #ifdef HAVE_SCOPELIB
392 	if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
393 		goto bad;
394 #else
395 	/* XXX: assume interface IDs as link IDs */
396 	ifi->linkid = ifi->sdl->sdl_index;
397 #endif
398 
399 	/*
400 	 * check if the interface is available.
401 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
402 	 */
403 	ifi->mediareqok = 1;
404 	ifi->active = interface_status(ifi);
405 	if (!ifi->mediareqok) {
406 		/*
407 		 * probe routers periodically even if the link status
408 		 * does not change.
409 		 */
410 		ifi->probeinterval = PROBE_INTERVAL;
411 	}
412 
413 	/* activate interface: interface_up returns 0 on success */
414 	flags = interface_up(ifi->ifname);
415 	if (flags == 0)
416 		ifi->state = IFS_DELAY;
417 	else if (flags == IFS_TENTATIVE)
418 		ifi->state = IFS_TENTATIVE;
419 	else
420 		ifi->state = IFS_DOWN;
421 
422 	rtsol_timer_update(ifi);
423 
424 	TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
425 	return (0);
426 
427 bad:
428 	free(sdl);
429 	free(ifi);
430 	return (-1);
431 }
432 
433 struct rainfo *
434 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
435 {
436 	struct rainfo *rai;
437 
438 	TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
439 		if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
440 		    sizeof(rai->rai_saddr.sin6_addr)) == 0)
441 			return (rai);
442 
443 	return (NULL);
444 }
445 
446 struct ifinfo *
447 find_ifinfo(int ifindex)
448 {
449 	struct ifinfo *ifi;
450 
451 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
452 		if (ifi->sdl->sdl_index == ifindex)
453 			return (ifi);
454 	}
455 	return (NULL);
456 }
457 
458 static int
459 make_packet(struct ifinfo *ifi)
460 {
461 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
462 	struct nd_router_solicit *rs;
463 	char *buf;
464 
465 	if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
466 		warnmsg(LOG_INFO, __func__,
467 		    "link-layer address option has null length"
468 		    " on %s. Treat as not included.", ifi->ifname);
469 	}
470 	packlen += lladdroptlen;
471 	ifi->rs_datalen = packlen;
472 
473 	/* allocate buffer */
474 	if ((buf = malloc(packlen)) == NULL) {
475 		warnmsg(LOG_ERR, __func__,
476 		    "memory allocation failed for %s", ifi->ifname);
477 		return (-1);
478 	}
479 	ifi->rs_data = buf;
480 
481 	/* fill in the message */
482 	rs = (struct nd_router_solicit *)buf;
483 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
484 	rs->nd_rs_code = 0;
485 	rs->nd_rs_cksum = 0;
486 	rs->nd_rs_reserved = 0;
487 	buf += sizeof(*rs);
488 
489 	/* fill in source link-layer address option */
490 	if (lladdroptlen)
491 		lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
492 
493 	return (0);
494 }
495 
496 static struct timespec *
497 rtsol_check_timer(void)
498 {
499 	static struct timespec returnval;
500 	struct timespec now, rtsol_timer;
501 	struct ifinfo *ifi;
502 	struct rainfo *rai;
503 	struct ra_opt *rao, *raotmp;
504 	int flags;
505 
506 	clock_gettime(CLOCK_MONOTONIC_FAST, &now);
507 
508 	rtsol_timer = tm_max;
509 
510 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
511 		if (TS_CMP(&ifi->expire, &now, <=)) {
512 			warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
513 			    "state = %d", ifi->ifname, ifi->state);
514 
515 			while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
516 				/* Remove all RA options. */
517 				TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
518 				while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
519 				    NULL) {
520 					TAILQ_REMOVE(&rai->rai_ra_opt, rao,
521 					    rao_next);
522 					if (rao->rao_msg != NULL)
523 						free(rao->rao_msg);
524 					free(rao);
525 				}
526 				free(rai);
527 			}
528 			switch (ifi->state) {
529 			case IFS_DOWN:
530 			case IFS_TENTATIVE:
531 				/* interface_up returns 0 on success */
532 				flags = interface_up(ifi->ifname);
533 				if (flags == 0)
534 					ifi->state = IFS_DELAY;
535 				else if (flags == IFS_TENTATIVE)
536 					ifi->state = IFS_TENTATIVE;
537 				else
538 					ifi->state = IFS_DOWN;
539 				break;
540 			case IFS_IDLE:
541 			{
542 				int oldstatus = ifi->active;
543 				int probe = 0;
544 
545 				ifi->active = interface_status(ifi);
546 
547 				if (oldstatus != ifi->active) {
548 					warnmsg(LOG_DEBUG, __func__,
549 					    "%s status is changed"
550 					    " from %d to %d",
551 					    ifi->ifname,
552 					    oldstatus, ifi->active);
553 					probe = 1;
554 					ifi->state = IFS_DELAY;
555 				} else if (ifi->probeinterval &&
556 				    (ifi->probetimer -=
557 				    ifi->timer.tv_sec) <= 0) {
558 					/* probe timer expired */
559 					ifi->probetimer =
560 					    ifi->probeinterval;
561 					probe = 1;
562 					ifi->state = IFS_PROBE;
563 				}
564 
565 				/*
566 				 * If we need a probe, clear the previous
567 				 * status wrt the "other" configuration.
568 				 */
569 				if (probe)
570 					ifi->otherconfig = 0;
571 
572 				if (probe && mobile_node)
573 					defrouter_probe(ifi);
574 				break;
575 			}
576 			case IFS_DELAY:
577 				ifi->state = IFS_PROBE;
578 				sendpacket(ifi);
579 				break;
580 			case IFS_PROBE:
581 				if (ifi->probes < MAX_RTR_SOLICITATIONS)
582 					sendpacket(ifi);
583 				else {
584 					warnmsg(LOG_INFO, __func__,
585 					    "No answer after sending %d RSs",
586 					    ifi->probes);
587 					ifi->probes = 0;
588 					ifi->state = IFS_IDLE;
589 				}
590 				break;
591 			}
592 			rtsol_timer_update(ifi);
593 		} else {
594 			/* Expiration check for RA options. */
595 			int expire = 0;
596 
597 			TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
598 				TAILQ_FOREACH_SAFE(rao, &rai->rai_ra_opt,
599 				    rao_next, raotmp) {
600 					warnmsg(LOG_DEBUG, __func__,
601 					    "RA expiration timer: "
602 					    "type=%d, msg=%s, expire=%s",
603 					    rao->rao_type, (char *)rao->rao_msg,
604 						sec2str(&rao->rao_expire));
605 					if (TS_CMP(&now, &rao->rao_expire,
606 					    >=)) {
607 						warnmsg(LOG_DEBUG, __func__,
608 						    "RA expiration timer: "
609 						    "expired.");
610 						TAILQ_REMOVE(&rai->rai_ra_opt,
611 						    rao, rao_next);
612 						if (rao->rao_msg != NULL)
613 							free(rao->rao_msg);
614 						free(rao);
615 						expire = 1;
616 					}
617 				}
618 			}
619 			if (expire)
620 				ra_opt_handler(ifi);
621 		}
622 		if (TS_CMP(&ifi->expire, &rtsol_timer, <))
623 			rtsol_timer = ifi->expire;
624 	}
625 
626 	if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
627 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
628 		return (NULL);
629 	} else if (TS_CMP(&rtsol_timer, &now, <))
630 		/* this may occur when the interval is too small */
631 		returnval.tv_sec = returnval.tv_nsec = 0;
632 	else
633 		TS_SUB(&rtsol_timer, &now, &returnval);
634 
635 	now.tv_sec += returnval.tv_sec;
636 	now.tv_nsec += returnval.tv_nsec;
637 	warnmsg(LOG_DEBUG, __func__, "New timer is %s",
638 	    sec2str(&now));
639 
640 	return (&returnval);
641 }
642 
643 void
644 rtsol_timer_update(struct ifinfo *ifi)
645 {
646 #define MILLION 1000000
647 #define DADRETRY 10		/* XXX: adhoc */
648 	long interval;
649 	struct timespec now;
650 
651 	bzero(&ifi->timer, sizeof(ifi->timer));
652 
653 	switch (ifi->state) {
654 	case IFS_DOWN:
655 	case IFS_TENTATIVE:
656 		if (++ifi->dadcount > DADRETRY) {
657 			ifi->dadcount = 0;
658 			ifi->timer.tv_sec = PROBE_INTERVAL;
659 		} else
660 			ifi->timer.tv_sec = 1;
661 		break;
662 	case IFS_IDLE:
663 		if (mobile_node) {
664 			/* XXX should be configurable */
665 			ifi->timer.tv_sec = 3;
666 		}
667 		else
668 			ifi->timer = tm_max;	/* stop timer(valid?) */
669 		break;
670 	case IFS_DELAY:
671 		interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
672 		ifi->timer.tv_sec = interval / MILLION;
673 		ifi->timer.tv_nsec = (interval % MILLION) * 1000;
674 		break;
675 	case IFS_PROBE:
676 		if (ifi->probes < MAX_RTR_SOLICITATIONS)
677 			ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
678 		else {
679 			/*
680 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
681 			 * we're just waiting for possible replies; there
682 			 * will be no more solicitation.  Thus, we change
683 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
684 			 * on RFC 2461, Section 6.3.7.
685 			 */
686 			ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
687 		}
688 		break;
689 	default:
690 		warnmsg(LOG_ERR, __func__,
691 		    "illegal interface state(%d) on %s",
692 		    ifi->state, ifi->ifname);
693 		return;
694 	}
695 
696 	/* reset the timer */
697 	if (TS_CMP(&ifi->timer, &tm_max, ==)) {
698 		ifi->expire = tm_max;
699 		warnmsg(LOG_DEBUG, __func__,
700 		    "stop timer for %s", ifi->ifname);
701 	} else {
702 		clock_gettime(CLOCK_MONOTONIC_FAST, &now);
703 		TS_ADD(&now, &ifi->timer, &ifi->expire);
704 
705 		now.tv_sec += ifi->timer.tv_sec;
706 		now.tv_nsec += ifi->timer.tv_nsec;
707 		warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
708 		    ifi->ifname, sec2str(&now));
709 	}
710 
711 #undef MILLION
712 }
713 
714 #ifndef SMALL
715 static void
716 rtsold_set_dump_file(int sig __unused)
717 {
718 	do_dump = 1;
719 }
720 #endif
721 
722 static void
723 usage(void)
724 {
725 #ifndef SMALL
726 	fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
727 	    "[-p pidfile] [-R script-name] interface ...\n");
728 	fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
729 	    "[-p pidfile] [-R script-name] -a\n");
730 #else
731 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
732 	    "[-p pidfile] [-R script-name] interface ...\n");
733 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
734 	    "[-p pidfile] [-R script-name] -a\n");
735 #endif
736 }
737 
738 void
739 warnmsg(int priority, const char *func, const char *msg, ...)
740 {
741 	va_list ap;
742 	char buf[BUFSIZ];
743 
744 	va_start(ap, msg);
745 	if (fflag) {
746 		if (priority <= log_upto) {
747 			(void)vfprintf(stderr, msg, ap);
748 			(void)fprintf(stderr, "\n");
749 		}
750 	} else {
751 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
752 		msg = buf;
753 		vsyslog(priority, msg, ap);
754 	}
755 	va_end(ap);
756 }
757 
758 /*
759  * return a list of interfaces which is suitable to sending an RS.
760  */
761 static char **
762 autoifprobe(void)
763 {
764 	static char **argv = NULL;
765 	static int n = 0;
766 	char **a;
767 	int s = 0, i, found;
768 	struct ifaddrs *ifap, *ifa;
769 	struct in6_ndireq nd;
770 
771 	/* initialize */
772 	while (n--)
773 		free(argv[n]);
774 	if (argv) {
775 		free(argv);
776 		argv = NULL;
777 	}
778 	n = 0;
779 
780 	if (getifaddrs(&ifap) != 0)
781 		return (NULL);
782 
783 	if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
784 		warnmsg(LOG_ERR, __func__, "socket");
785 		exit(1);
786 	}
787 
788 	/* find an ethernet */
789 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
790 		if ((ifa->ifa_flags & IFF_UP) == 0)
791 			continue;
792 		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
793 			continue;
794 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
795 			continue;
796 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
797 			continue;
798 
799 		if (ifa->ifa_addr->sa_family != AF_INET6)
800 			continue;
801 
802 		found = 0;
803 		for (i = 0; i < n; i++) {
804 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
805 				found++;
806 				break;
807 			}
808 		}
809 		if (found)
810 			continue;
811 
812 		/*
813 		 * Skip the interfaces which IPv6 and/or accepting RA
814 		 * is disabled.
815 		 */
816 		if (!Fflag) {
817 			memset(&nd, 0, sizeof(nd));
818 			strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
819 			if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
820 				warnmsg(LOG_ERR, __func__,
821 					"ioctl(SIOCGIFINFO_IN6)");
822 				exit(1);
823 			}
824 			if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
825 				continue;
826 			if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
827 				continue;
828 		}
829 
830 		/* if we find multiple candidates, just warn. */
831 		if (n != 0 && dflag > 1)
832 			warnmsg(LOG_WARNING, __func__,
833 				"multiple interfaces found");
834 
835 		a = realloc(argv, (n + 1) * sizeof(char *));
836 		if (a == NULL) {
837 			warnmsg(LOG_ERR, __func__, "realloc");
838 			exit(1);
839 		}
840 		argv = a;
841 		argv[n] = strdup(ifa->ifa_name);
842 		if (!argv[n]) {
843 			warnmsg(LOG_ERR, __func__, "malloc");
844 			exit(1);
845 		}
846 		n++;
847 	}
848 
849 	if (n) {
850 		a = realloc(argv, (n + 1) * sizeof(char *));
851 		if (a == NULL) {
852 			warnmsg(LOG_ERR, __func__, "realloc");
853 			exit(1);
854 		}
855 		argv = a;
856 		argv[n] = NULL;
857 
858 		if (dflag > 0) {
859 			for (i = 0; i < n; i++)
860 				warnmsg(LOG_WARNING, __func__, "probing %s",
861 					argv[i]);
862 		}
863 	}
864 	if (!Fflag)
865 		close(s);
866 	freeifaddrs(ifap);
867 	return (argv);
868 }
869