xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision c9dbb1cc52b063bbd9ab078a7afc89a8696da659)
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 #include <poll.h>
61 
62 #include "rtsold.h"
63 
64 #define RTSOL_DUMPFILE	"/var/run/rtsold.dump";
65 #define RTSOL_PIDFILE	"/var/run/rtsold.pid";
66 
67 struct timespec tm_max;
68 static int log_upto = 999;
69 static int fflag = 0;
70 
71 int Fflag = 0;	/* force setting sysctl parameters */
72 int aflag = 0;
73 int dflag = 0;
74 int uflag = 0;
75 
76 const char *otherconf_script;
77 const char *resolvconf_script = "/sbin/resolvconf";
78 
79 /* protocol constants */
80 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
81 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
82 #define MAX_RTR_SOLICITATIONS		3 /* times */
83 
84 /*
85  * implementation dependent constants in seconds
86  * XXX: should be configurable
87  */
88 #define PROBE_INTERVAL 60
89 
90 /* static variables and functions */
91 static int mobile_node = 0;
92 static const char *pidfilename = RTSOL_PIDFILE;
93 
94 #ifndef SMALL
95 static int do_dump;
96 static const char *dumpfilename = RTSOL_DUMPFILE;
97 #endif
98 
99 #if 0
100 static int ifreconfig(char *);
101 #endif
102 
103 static int make_packet(struct ifinfo *);
104 static struct timespec *rtsol_check_timer(void);
105 
106 #ifndef SMALL
107 static void rtsold_set_dump_file(int);
108 #endif
109 static void usage(void);
110 
111 int
112 main(int argc, char **argv)
113 {
114 	int s, ch, once = 0;
115 	struct timespec *timeout;
116 	const char *opts;
117 	struct pollfd set[2];
118 	int rtsock;
119 	char *argv0;
120 
121 #ifndef SMALL
122 	/* rtsold */
123 	opts = "adDfFm1O:p:R:u";
124 #else
125 	/* rtsol */
126 	opts = "adDFO:R:u";
127 	fflag = 1;
128 	once = 1;
129 #endif
130 	argv0 = argv[0];
131 
132 	while ((ch = getopt(argc, argv, opts)) != -1) {
133 		switch (ch) {
134 		case 'a':
135 			aflag = 1;
136 			break;
137 		case 'd':
138 			dflag += 1;
139 			break;
140 		case 'D':
141 			dflag += 2;
142 			break;
143 		case 'f':
144 			fflag = 1;
145 			break;
146 		case 'F':
147 			Fflag = 1;
148 			break;
149 		case 'm':
150 			mobile_node = 1;
151 			break;
152 		case '1':
153 			once = 1;
154 			break;
155 		case 'O':
156 			otherconf_script = optarg;
157 			break;
158 		case 'p':
159 			pidfilename = optarg;
160 			break;
161 		case 'R':
162 			resolvconf_script = optarg;
163 			break;
164 		case 'u':
165 			uflag = 1;
166 			break;
167 		default:
168 			usage();
169 			exit(1);
170 		}
171 	}
172 	argc -= optind;
173 	argv += optind;
174 
175 	if ((!aflag && argc == 0) || (aflag && argc != 0)) {
176 		usage();
177 		exit(1);
178 	}
179 
180 	/* Generate maximum time in timespec. */
181 	tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1));
182 	tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1));
183 
184 	/* set log level */
185 	if (dflag > 1)
186 		log_upto = LOG_DEBUG;
187 	else if (dflag > 0)
188 		log_upto = LOG_INFO;
189 	else
190 		log_upto = LOG_NOTICE;
191 
192 	if (!fflag) {
193 		char *ident;
194 
195 		ident = strrchr(argv0, '/');
196 		if (!ident)
197 			ident = argv0;
198 		else
199 			ident++;
200 		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
201 		if (log_upto >= 0)
202 			setlogmask(LOG_UPTO(log_upto));
203 	}
204 
205 	if (otherconf_script && *otherconf_script != '/') {
206 		errx(1, "configuration script (%s) must be an absolute path",
207 		    otherconf_script);
208 	}
209 	if (resolvconf_script && *resolvconf_script != '/') {
210 		errx(1, "configuration script (%s) must be an absolute path",
211 		    resolvconf_script);
212 	}
213 	if (pidfilename && *pidfilename != '/') {
214 		errx(1, "pid filename (%s) must be an absolute path",
215 		    pidfilename);
216 	}
217 #ifndef HAVE_ARC4RANDOM
218 	/* random value initialization */
219 	srandom((u_long)time(NULL));
220 #endif
221 
222 #if (__FreeBSD_version < 900000)
223 	if (Fflag) {
224 		setinet6sysctl(IPV6CTL_FORWARDING, 0);
225 	} else {
226 		/* warn if forwarding is up */
227 		if (getinet6sysctl(IPV6CTL_FORWARDING))
228 			warnx("kernel is configured as a router, not a host");
229 	}
230 #endif
231 
232 #ifndef SMALL
233 	/* initialization to dump internal status to a file */
234 	signal(SIGUSR1, rtsold_set_dump_file);
235 #endif
236 
237 	if (!fflag)
238 		daemon(0, 0);		/* act as a daemon */
239 
240 	/*
241 	 * Open a socket for sending RS and receiving RA.
242 	 * This should be done before calling ifinit(), since the function
243 	 * uses the socket.
244 	 */
245 	if ((s = sockopen()) < 0) {
246 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
247 		exit(1);
248 	}
249 	set[0].fd = s;
250 	set[0].events = POLLIN;
251 	set[1].fd = -1;
252 
253 	if ((rtsock = rtsock_open()) < 0) {
254 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
255 		exit(1);
256 	}
257 	set[1].fd = rtsock;
258 	set[1].events = POLLIN;
259 
260 	/* configuration per interface */
261 	if (ifinit()) {
262 		warnmsg(LOG_ERR, __func__,
263 		    "failed to initialize interfaces");
264 		exit(1);
265 	}
266 	if (aflag)
267 		argv = autoifprobe();
268 	while (argv && *argv) {
269 		if (ifconfig(*argv)) {
270 			warnmsg(LOG_ERR, __func__,
271 			    "failed to initialize %s", *argv);
272 			exit(1);
273 		}
274 		argv++;
275 	}
276 
277 	/* setup for probing default routers */
278 	if (probe_init()) {
279 		warnmsg(LOG_ERR, __func__,
280 		    "failed to setup for probing routers");
281 		exit(1);
282 		/*NOTREACHED*/
283 	}
284 
285 	/* dump the current pid */
286 	if (!once) {
287 		pid_t pid = getpid();
288 		FILE *fp;
289 
290 		if ((fp = fopen(pidfilename, "w")) == NULL)
291 			warnmsg(LOG_ERR, __func__,
292 			    "failed to open a pid log file(%s): %s",
293 			    pidfilename, strerror(errno));
294 		else {
295 			fprintf(fp, "%d\n", pid);
296 			fclose(fp);
297 		}
298 	}
299 	while (1) {		/* main loop */
300 		int e;
301 #ifndef SMALL
302 		if (do_dump) {	/* SIGUSR1 */
303 			do_dump = 0;
304 			rtsold_dump_file(dumpfilename);
305 		}
306 #endif
307 
308 		timeout = rtsol_check_timer();
309 
310 		if (once) {
311 			struct ifinfo *ifi;
312 
313 			/* if we have no timeout, we are done (or failed) */
314 			if (timeout == NULL)
315 				break;
316 
317 			/* if all interfaces have got RA packet, we are done */
318 			TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
319 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
320 					break;
321 			}
322 			if (ifi == NULL)
323 				break;
324 		}
325 		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_nsec / 1000 / 1000) : INFTIM);
326 		if (e < 1) {
327 			if (e < 0 && errno != EINTR) {
328 				warnmsg(LOG_ERR, __func__, "select: %s",
329 				    strerror(errno));
330 			}
331 			continue;
332 		}
333 
334 		/* packet reception */
335 		if (set[1].revents & POLLIN)
336 			rtsock_input(rtsock);
337 		if (set[0].revents & POLLIN)
338 			rtsol_input(s);
339 	}
340 	/* NOTREACHED */
341 
342 	return (0);
343 }
344 
345 int
346 ifconfig(char *ifname)
347 {
348 	struct ifinfo *ifi;
349 	struct sockaddr_dl *sdl;
350 	int flags;
351 
352 	if ((sdl = if_nametosdl(ifname)) == NULL) {
353 		warnmsg(LOG_ERR, __func__,
354 		    "failed to get link layer information for %s", ifname);
355 		return (-1);
356 	}
357 	if (find_ifinfo(sdl->sdl_index)) {
358 		warnmsg(LOG_ERR, __func__,
359 		    "interface %s was already configured", ifname);
360 		free(sdl);
361 		return (-1);
362 	}
363 
364 	if (Fflag) {
365 		struct in6_ndireq nd;
366 		int s;
367 
368 		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
369 			warnmsg(LOG_ERR, __func__, "socket() failed.");
370 			return (-1);
371 		}
372 		memset(&nd, 0, sizeof(nd));
373 		strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
374 		if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
375 			warnmsg(LOG_ERR, __func__,
376 			    "cannot get accept_rtadv flag");
377 			close(s);
378 			return (-1);
379 		}
380 		nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
381 		if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
382 			warnmsg(LOG_ERR, __func__,
383 			    "cannot set accept_rtadv flag");
384 			close(s);
385 			return (-1);
386 		}
387 		close(s);
388 	}
389 
390 	if ((ifi = malloc(sizeof(*ifi))) == NULL) {
391 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
392 		free(sdl);
393 		return (-1);
394 	}
395 	memset(ifi, 0, sizeof(*ifi));
396 	ifi->sdl = sdl;
397 	ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
398 	ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
399 	TAILQ_INIT(&ifi->ifi_rainfo);
400 	strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
401 
402 	/* construct a router solicitation message */
403 	if (make_packet(ifi))
404 		goto bad;
405 
406 	/* set link ID of this interface. */
407 #ifdef HAVE_SCOPELIB
408 	if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
409 		goto bad;
410 #else
411 	/* XXX: assume interface IDs as link IDs */
412 	ifi->linkid = ifi->sdl->sdl_index;
413 #endif
414 
415 	/*
416 	 * check if the interface is available.
417 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
418 	 */
419 	ifi->mediareqok = 1;
420 	ifi->active = interface_status(ifi);
421 	if (!ifi->mediareqok) {
422 		/*
423 		 * probe routers periodically even if the link status
424 		 * does not change.
425 		 */
426 		ifi->probeinterval = PROBE_INTERVAL;
427 	}
428 
429 	/* activate interface: interface_up returns 0 on success */
430 	flags = interface_up(ifi->ifname);
431 	if (flags == 0)
432 		ifi->state = IFS_DELAY;
433 	else if (flags == IFS_TENTATIVE)
434 		ifi->state = IFS_TENTATIVE;
435 	else
436 		ifi->state = IFS_DOWN;
437 
438 	rtsol_timer_update(ifi);
439 
440 	TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
441 	return (0);
442 
443 bad:
444 	free(ifi->sdl);
445 	free(ifi);
446 	return (-1);
447 }
448 
449 void
450 iflist_init(void)
451 {
452 	struct ifinfo *ifi;
453 
454 	while ((ifi = TAILQ_FIRST(&ifinfo_head)) != NULL) {
455 		TAILQ_REMOVE(&ifinfo_head, ifi, ifi_next);
456 		if (ifi->sdl != NULL)
457 			free(ifi->sdl);
458 		if (ifi->rs_data != NULL)
459 			free(ifi->rs_data);
460 		free(ifi);
461 	}
462 }
463 
464 #if 0
465 static int
466 ifreconfig(char *ifname)
467 {
468 	struct ifinfo *ifi, *prev;
469 	int rv;
470 
471 	prev = NULL;
472 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
473 		if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
474 			break;
475 		prev = ifi;
476 	}
477 	prev->next = ifi->next;
478 
479 	rv = ifconfig(ifname);
480 
481 	/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
482 	if (ifi->rs_data)
483 		free(ifi->rs_data);
484 	free(ifi->sdl);
485 	free(ifi);
486 
487 	return (rv);
488 }
489 #endif
490 
491 struct rainfo *
492 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
493 {
494 	struct rainfo *rai;
495 
496 	TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
497 		if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
498 		    sizeof(rai->rai_saddr.sin6_addr)) == 0)
499 			return (rai);
500 
501 	return (NULL);
502 }
503 
504 struct ifinfo *
505 find_ifinfo(int ifindex)
506 {
507 	struct ifinfo *ifi;
508 
509 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
510 		if (ifi->sdl->sdl_index == ifindex)
511 			return (ifi);
512 	}
513 	return (NULL);
514 }
515 
516 static int
517 make_packet(struct ifinfo *ifi)
518 {
519 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
520 	struct nd_router_solicit *rs;
521 	char *buf;
522 
523 	if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
524 		warnmsg(LOG_INFO, __func__,
525 		    "link-layer address option has null length"
526 		    " on %s. Treat as not included.", ifi->ifname);
527 	}
528 	packlen += lladdroptlen;
529 	ifi->rs_datalen = packlen;
530 
531 	/* allocate buffer */
532 	if ((buf = malloc(packlen)) == NULL) {
533 		warnmsg(LOG_ERR, __func__,
534 		    "memory allocation failed for %s", ifi->ifname);
535 		return (-1);
536 	}
537 	ifi->rs_data = buf;
538 
539 	/* fill in the message */
540 	rs = (struct nd_router_solicit *)buf;
541 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
542 	rs->nd_rs_code = 0;
543 	rs->nd_rs_cksum = 0;
544 	rs->nd_rs_reserved = 0;
545 	buf += sizeof(*rs);
546 
547 	/* fill in source link-layer address option */
548 	if (lladdroptlen)
549 		lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
550 
551 	return (0);
552 }
553 
554 static struct timespec *
555 rtsol_check_timer(void)
556 {
557 	static struct timespec returnval;
558 	struct timespec now, rtsol_timer;
559 	struct ifinfo *ifi;
560 	struct rainfo *rai;
561 	struct ra_opt *rao;
562 	int flags;
563 
564 	clock_gettime(CLOCK_MONOTONIC_FAST, &now);
565 
566 	rtsol_timer = tm_max;
567 
568 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
569 		if (TS_CMP(&ifi->expire, &now, <=)) {
570 			warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
571 			    "state = %d", ifi->ifname, ifi->state);
572 
573 			while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
574 				/* Remove all RA options. */
575 				TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
576 				while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
577 				    NULL) {
578 					TAILQ_REMOVE(&rai->rai_ra_opt, rao,
579 					    rao_next);
580 					if (rao->rao_msg != NULL)
581 						free(rao->rao_msg);
582 					free(rao);
583 				}
584 				free(rai);
585 			}
586 			switch (ifi->state) {
587 			case IFS_DOWN:
588 			case IFS_TENTATIVE:
589 				/* interface_up returns 0 on success */
590 				flags = interface_up(ifi->ifname);
591 				if (flags == 0)
592 					ifi->state = IFS_DELAY;
593 				else if (flags == IFS_TENTATIVE)
594 					ifi->state = IFS_TENTATIVE;
595 				else
596 					ifi->state = IFS_DOWN;
597 				break;
598 			case IFS_IDLE:
599 			{
600 				int oldstatus = ifi->active;
601 				int probe = 0;
602 
603 				ifi->active = interface_status(ifi);
604 
605 				if (oldstatus != ifi->active) {
606 					warnmsg(LOG_DEBUG, __func__,
607 					    "%s status is changed"
608 					    " from %d to %d",
609 					    ifi->ifname,
610 					    oldstatus, ifi->active);
611 					probe = 1;
612 					ifi->state = IFS_DELAY;
613 				} else if (ifi->probeinterval &&
614 				    (ifi->probetimer -=
615 				    ifi->timer.tv_sec) <= 0) {
616 					/* probe timer expired */
617 					ifi->probetimer =
618 					    ifi->probeinterval;
619 					probe = 1;
620 					ifi->state = IFS_PROBE;
621 				}
622 
623 				/*
624 				 * If we need a probe, clear the previous
625 				 * status wrt the "other" configuration.
626 				 */
627 				if (probe)
628 					ifi->otherconfig = 0;
629 
630 				if (probe && mobile_node)
631 					defrouter_probe(ifi);
632 				break;
633 			}
634 			case IFS_DELAY:
635 				ifi->state = IFS_PROBE;
636 				sendpacket(ifi);
637 				break;
638 			case IFS_PROBE:
639 				if (ifi->probes < MAX_RTR_SOLICITATIONS)
640 					sendpacket(ifi);
641 				else {
642 					warnmsg(LOG_INFO, __func__,
643 					    "No answer after sending %d RSs",
644 					    ifi->probes);
645 					ifi->probes = 0;
646 					ifi->state = IFS_IDLE;
647 				}
648 				break;
649 			}
650 			rtsol_timer_update(ifi);
651 		} else {
652 			/* Expiration check for RA options. */
653 			int expire = 0;
654 
655 			TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
656 				TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
657 					warnmsg(LOG_DEBUG, __func__,
658 					    "RA expiration timer: "
659 					    "type=%d, msg=%s, expire=%s",
660 					    rao->rao_type, (char *)rao->rao_msg,
661 						sec2str(&rao->rao_expire));
662 					if (TS_CMP(&now, &rao->rao_expire,
663 					    >=)) {
664 						warnmsg(LOG_DEBUG, __func__,
665 						    "RA expiration timer: "
666 						    "expired.");
667 						TAILQ_REMOVE(&rai->rai_ra_opt,
668 						    rao, rao_next);
669 						if (rao->rao_msg != NULL)
670 							free(rao->rao_msg);
671 						free(rao);
672 						expire = 1;
673 					}
674 				}
675 			}
676 			if (expire)
677 				ra_opt_handler(ifi);
678 		}
679 		if (TS_CMP(&ifi->expire, &rtsol_timer, <))
680 			rtsol_timer = ifi->expire;
681 	}
682 
683 	if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
684 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
685 		return (NULL);
686 	} else if (TS_CMP(&rtsol_timer, &now, <))
687 		/* this may occur when the interval is too small */
688 		returnval.tv_sec = returnval.tv_nsec = 0;
689 	else
690 		TS_SUB(&rtsol_timer, &now, &returnval);
691 
692 	now.tv_sec += returnval.tv_sec;
693 	now.tv_nsec += returnval.tv_nsec;
694 	warnmsg(LOG_DEBUG, __func__, "New timer is %s",
695 	    sec2str(&now));
696 
697 	return (&returnval);
698 }
699 
700 void
701 rtsol_timer_update(struct ifinfo *ifi)
702 {
703 #define MILLION 1000000
704 #define DADRETRY 10		/* XXX: adhoc */
705 	long interval;
706 	struct timespec now;
707 
708 	bzero(&ifi->timer, sizeof(ifi->timer));
709 
710 	switch (ifi->state) {
711 	case IFS_DOWN:
712 	case IFS_TENTATIVE:
713 		if (++ifi->dadcount > DADRETRY) {
714 			ifi->dadcount = 0;
715 			ifi->timer.tv_sec = PROBE_INTERVAL;
716 		} else
717 			ifi->timer.tv_sec = 1;
718 		break;
719 	case IFS_IDLE:
720 		if (mobile_node) {
721 			/* XXX should be configurable */
722 			ifi->timer.tv_sec = 3;
723 		}
724 		else
725 			ifi->timer = tm_max;	/* stop timer(valid?) */
726 		break;
727 	case IFS_DELAY:
728 #ifndef HAVE_ARC4RANDOM
729 		interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
730 #else
731 		interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
732 #endif
733 		ifi->timer.tv_sec = interval / MILLION;
734 		ifi->timer.tv_nsec = (interval % MILLION) * 1000;
735 		break;
736 	case IFS_PROBE:
737 		if (ifi->probes < MAX_RTR_SOLICITATIONS)
738 			ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
739 		else {
740 			/*
741 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
742 			 * we're just waiting for possible replies; there
743 			 * will be no more solicitation.  Thus, we change
744 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
745 			 * on RFC 2461, Section 6.3.7.
746 			 */
747 			ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
748 		}
749 		break;
750 	default:
751 		warnmsg(LOG_ERR, __func__,
752 		    "illegal interface state(%d) on %s",
753 		    ifi->state, ifi->ifname);
754 		return;
755 	}
756 
757 	/* reset the timer */
758 	if (TS_CMP(&ifi->timer, &tm_max, ==)) {
759 		ifi->expire = tm_max;
760 		warnmsg(LOG_DEBUG, __func__,
761 		    "stop timer for %s", ifi->ifname);
762 	} else {
763 		clock_gettime(CLOCK_MONOTONIC_FAST, &now);
764 		TS_ADD(&now, &ifi->timer, &ifi->expire);
765 
766 		now.tv_sec += ifi->timer.tv_sec;
767 		now.tv_nsec += ifi->timer.tv_nsec;
768 		warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
769 		    ifi->ifname, sec2str(&now));
770 	}
771 
772 #undef MILLION
773 }
774 
775 /* timer related utility functions */
776 #define MILLION 1000000
777 
778 #ifndef SMALL
779 static void
780 rtsold_set_dump_file(int sig __unused)
781 {
782 	do_dump = 1;
783 }
784 #endif
785 
786 static void
787 usage(void)
788 {
789 #ifndef SMALL
790 	fprintf(stderr, "usage: rtsold [-adDfFm1] [-O script-name] "
791 	    "[-P pidfile] [-R script-name] interfaces...\n");
792 	fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
793 	    "[-P pidfile] [-R script-name] -a\n");
794 #else
795 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
796 	    "[-P pidfile] [-R script-name] interfaces...\n");
797 	fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
798 	    "[-P pidfile] [-R script-name] -a\n");
799 #endif
800 }
801 
802 void
803 warnmsg(int priority, const char *func, const char *msg, ...)
804 {
805 	va_list ap;
806 	char buf[BUFSIZ];
807 
808 	va_start(ap, msg);
809 	if (fflag) {
810 		if (priority <= log_upto) {
811 			(void)vfprintf(stderr, msg, ap);
812 			(void)fprintf(stderr, "\n");
813 		}
814 	} else {
815 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
816 		msg = buf;
817 		vsyslog(priority, msg, ap);
818 	}
819 	va_end(ap);
820 }
821 
822 /*
823  * return a list of interfaces which is suitable to sending an RS.
824  */
825 char **
826 autoifprobe(void)
827 {
828 	static char **argv = NULL;
829 	static int n = 0;
830 	char **a;
831 	int s = 0, i, found;
832 	struct ifaddrs *ifap, *ifa;
833 	struct in6_ndireq nd;
834 
835 	/* initialize */
836 	while (n--)
837 		free(argv[n]);
838 	if (argv) {
839 		free(argv);
840 		argv = NULL;
841 	}
842 	n = 0;
843 
844 	if (getifaddrs(&ifap) != 0)
845 		return (NULL);
846 
847 	if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
848 		warnmsg(LOG_ERR, __func__, "socket");
849 		exit(1);
850 	}
851 
852 	/* find an ethernet */
853 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
854 		if ((ifa->ifa_flags & IFF_UP) == 0)
855 			continue;
856 		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
857 			continue;
858 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
859 			continue;
860 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
861 			continue;
862 
863 		if (ifa->ifa_addr->sa_family != AF_INET6)
864 			continue;
865 
866 		found = 0;
867 		for (i = 0; i < n; i++) {
868 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
869 				found++;
870 				break;
871 			}
872 		}
873 		if (found)
874 			continue;
875 
876 		/*
877 		 * Skip the interfaces which IPv6 and/or accepting RA
878 		 * is disabled.
879 		 */
880 		if (!Fflag) {
881 			memset(&nd, 0, sizeof(nd));
882 			strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
883 			if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
884 				warnmsg(LOG_ERR, __func__,
885 					"ioctl(SIOCGIFINFO_IN6)");
886 				exit(1);
887 			}
888 			if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
889 				continue;
890 			if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
891 				continue;
892 		}
893 
894 		/* if we find multiple candidates, just warn. */
895 		if (n != 0 && dflag > 1)
896 			warnmsg(LOG_WARNING, __func__,
897 				"multiple interfaces found");
898 
899 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
900 		if (a == NULL) {
901 			warnmsg(LOG_ERR, __func__, "realloc");
902 			exit(1);
903 		}
904 		argv = a;
905 		argv[n] = strdup(ifa->ifa_name);
906 		if (!argv[n]) {
907 			warnmsg(LOG_ERR, __func__, "malloc");
908 			exit(1);
909 		}
910 		n++;
911 	}
912 
913 	if (n) {
914 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
915 		if (a == NULL) {
916 			warnmsg(LOG_ERR, __func__, "realloc");
917 			exit(1);
918 		}
919 		argv = a;
920 		argv[n] = NULL;
921 
922 		if (dflag > 0) {
923 			for (i = 0; i < n; i++)
924 				warnmsg(LOG_WARNING, __func__, "probing %s",
925 					argv[i]);
926 		}
927 	}
928 	if (!Fflag)
929 		close(s);
930 	freeifaddrs(ifap);
931 	return (argv);
932 }
933