xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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/time.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 
45 #include <signal.h>
46 #include <unistd.h>
47 #include <syslog.h>
48 #include <string.h>
49 #include <stdlib.h>
50 #include <stdio.h>
51 #include <errno.h>
52 #include <err.h>
53 #include <stdarg.h>
54 #include <ifaddrs.h>
55 #ifdef HAVE_POLL_H
56 #include <poll.h>
57 #endif
58 
59 #include "rtsold.h"
60 
61 struct ifinfo *iflist;
62 struct timeval tm_max =	{0x7fffffff, 0x7fffffff};
63 static int log_upto = 999;
64 static int fflag = 0;
65 
66 int aflag = 0;
67 int dflag = 0;
68 
69 char *otherconf_script;
70 
71 /* protocol constatns */
72 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
73 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
74 #define MAX_RTR_SOLICITATIONS		3 /* times */
75 
76 /*
77  * implementation dependent constants in seconds
78  * XXX: should be configurable
79  */
80 #define PROBE_INTERVAL 60
81 
82 /* utility macros */
83 /* a < b */
84 #define TIMEVAL_LT(a, b) (((a).tv_sec < (b).tv_sec) ||\
85 			  (((a).tv_sec == (b).tv_sec) && \
86 			    ((a).tv_usec < (b).tv_usec)))
87 
88 /* a <= b */
89 #define TIMEVAL_LEQ(a, b) (((a).tv_sec < (b).tv_sec) ||\
90 			   (((a).tv_sec == (b).tv_sec) &&\
91 			    ((a).tv_usec <= (b).tv_usec)))
92 
93 /* a == b */
94 #define TIMEVAL_EQ(a, b) (((a).tv_sec==(b).tv_sec) && ((a).tv_usec==(b).tv_usec))
95 
96 int main __P((int, char **));
97 
98 /* static variables and functions */
99 static int mobile_node = 0;
100 static int do_dump;
101 static char *dumpfilename = "/var/run/rtsold.dump"; /* XXX: should be configurable */
102 static char *pidfilename = "/var/run/rtsold.pid"; /* should be configurable */
103 
104 #if 0
105 static int ifreconfig __P((char *));
106 #endif
107 static int make_packet __P((struct ifinfo *));
108 static struct timeval *rtsol_check_timer __P((void));
109 static void TIMEVAL_ADD __P((struct timeval *, struct timeval *,
110 	struct timeval *));
111 static void TIMEVAL_SUB __P((struct timeval *, struct timeval *,
112 	struct timeval *));
113 
114 static void rtsold_set_dump_file __P((int));
115 static void usage __P((char *));
116 
117 int
118 main(argc, argv)
119 	int argc;
120 	char **argv;
121 {
122 	int s, ch, once = 0;
123 	struct timeval *timeout;
124 	char *argv0, *opts;
125 #ifdef HAVE_POLL_H
126 	struct pollfd set[2];
127 #else
128 	fd_set *fdsetp, *selectfdp;
129 	int fdmasks;
130 	int maxfd;
131 #endif
132 	int rtsock;
133 
134 	/*
135 	 * Initialization
136 	 */
137 	argv0 = argv[0];
138 
139 	/* get option */
140 	if (argv0 && argv0[strlen(argv0) - 1] != 'd') {
141 		fflag = 1;
142 		once = 1;
143 		opts = "adDO:";
144 	} else
145 		opts = "adDfm1O:";
146 
147 	while ((ch = getopt(argc, argv, opts)) != -1) {
148 		switch (ch) {
149 		case 'a':
150 			aflag = 1;
151 			break;
152 		case 'd':
153 			dflag = 1;
154 			break;
155 		case 'D':
156 			dflag = 2;
157 			break;
158 		case 'f':
159 			fflag = 1;
160 			break;
161 		case 'm':
162 			mobile_node = 1;
163 			break;
164 		case '1':
165 			once = 1;
166 			break;
167 		case 'O':
168 			otherconf_script = optarg;
169 			break;
170 		default:
171 			usage(argv0);
172 			/*NOTREACHED*/
173 		}
174 	}
175 	argc -= optind;
176 	argv += optind;
177 
178 	if ((!aflag && argc == 0) || (aflag && argc != 0)) {
179 		usage(argv0);
180 		/*NOTREACHED*/
181 	}
182 
183 	/* set log level */
184 	if (dflag == 0)
185 		log_upto = LOG_NOTICE;
186 	if (!fflag) {
187 		char *ident;
188 
189 		ident = strrchr(argv0, '/');
190 		if (!ident)
191 			ident = argv0;
192 		else
193 			ident++;
194 		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
195 		if (log_upto >= 0)
196 			setlogmask(LOG_UPTO(log_upto));
197 	}
198 
199 	if (otherconf_script && *otherconf_script != '/') {
200 		errx(1, "configuration script (%s) must be an absolute path",
201 		    otherconf_script);
202 	}
203 
204 #ifndef HAVE_ARC4RANDOM
205 	/* random value initialization */
206 	srandom((u_long)time(NULL));
207 #endif
208 
209 	/* warn if accept_rtadv is down */
210 	if (!getinet6sysctl(IPV6CTL_ACCEPT_RTADV))
211 		warnx("kernel is configured not to accept RAs");
212 	/* warn if forwarding is up */
213 	if (getinet6sysctl(IPV6CTL_FORWARDING))
214 		warnx("kernel is configured as a router, not a host");
215 
216 	/* initialization to dump internal status to a file */
217 	signal(SIGUSR1, rtsold_set_dump_file);
218 
219 	if (!fflag)
220 		daemon(0, 0);		/* act as a daemon */
221 
222 	/*
223 	 * Open a socket for sending RS and receiving RA.
224 	 * This should be done before calling ifinit(), since the function
225 	 * uses the socket.
226 	 */
227 	if ((s = sockopen()) < 0) {
228 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
229 		exit(1);
230 		/*NOTREACHED*/
231 	}
232 #ifdef HAVE_POLL_H
233 	set[0].fd = s;
234 	set[0].events = POLLIN;
235 #else
236 	maxfd = s;
237 #endif
238 
239 #ifdef HAVE_POLL_H
240 	set[1].fd = -1;
241 #endif
242 
243 	if ((rtsock = rtsock_open()) < 0) {
244 		warnmsg(LOG_ERR, __func__, "failed to open a socket");
245 		exit(1);
246 		/*NOTREACHED*/
247 	}
248 #ifdef HAVE_POLL_H
249 	set[1].fd = rtsock;
250 	set[1].events = POLLIN;
251 #else
252 	if (rtsock > maxfd)
253 		maxfd = rtsock;
254 #endif
255 
256 #ifndef HAVE_POLL_H
257 	fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask);
258 	if ((fdsetp = malloc(fdmasks)) == NULL) {
259 		err(1, "malloc");
260 		/*NOTREACHED*/
261 	}
262 	if ((selectfdp = malloc(fdmasks)) == NULL) {
263 		err(1, "malloc");
264 		/*NOTREACHED*/
265 	}
266 #endif
267 
268 	/* configuration per interface */
269 	if (ifinit()) {
270 		warnmsg(LOG_ERR, __func__,
271 		    "failed to initilizatoin interfaces");
272 		exit(1);
273 		/*NOTREACHED*/
274 	}
275 	if (aflag)
276 		argv = autoifprobe();
277 	while (argv && *argv) {
278 		if (ifconfig(*argv)) {
279 			warnmsg(LOG_ERR, __func__,
280 			    "failed to initialize %s", *argv);
281 			exit(1);
282 			/*NOTREACHED*/
283 		}
284 		argv++;
285 	}
286 
287 	/* setup for probing default routers */
288 	if (probe_init()) {
289 		warnmsg(LOG_ERR, __func__,
290 		    "failed to setup for probing routers");
291 		exit(1);
292 		/*NOTREACHED*/
293 	}
294 
295 	/* dump the current pid */
296 	if (!once) {
297 		pid_t pid = getpid();
298 		FILE *fp;
299 
300 		if ((fp = fopen(pidfilename, "w")) == NULL)
301 			warnmsg(LOG_ERR, __func__,
302 			    "failed to open a pid log file(%s): %s",
303 			    pidfilename, strerror(errno));
304 		else {
305 			fprintf(fp, "%d\n", pid);
306 			fclose(fp);
307 		}
308 	}
309 
310 #ifndef HAVE_POLL_H
311 	memset(fdsetp, 0, fdmasks);
312 	FD_SET(s, fdsetp);
313 	FD_SET(rtsock, fdsetp);
314 #endif
315 	while (1) {		/* main loop */
316 		int e;
317 
318 #ifndef HAVE_POLL_H
319 		memcpy(selectfdp, fdsetp, fdmasks);
320 #endif
321 
322 		if (do_dump) {	/* SIGUSR1 */
323 			do_dump = 0;
324 			rtsold_dump_file(dumpfilename);
325 		}
326 
327 		timeout = rtsol_check_timer();
328 
329 		if (once) {
330 			struct ifinfo *ifi;
331 
332 			/* if we have no timeout, we are done (or failed) */
333 			if (timeout == NULL)
334 				break;
335 
336 			/* if all interfaces have got RA packet, we are done */
337 			for (ifi = iflist; ifi; ifi = ifi->next) {
338 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
339 					break;
340 			}
341 			if (ifi == NULL)
342 				break;
343 		}
344 #ifdef HAVE_POLL_H
345 		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_usec / 1000) : INFTIM);
346 #else
347 		e = select(maxfd + 1, selectfdp, NULL, NULL, timeout);
348 #endif
349 		if (e < 1) {
350 			if (e < 0 && errno != EINTR) {
351 				warnmsg(LOG_ERR, __func__, "select: %s",
352 				    strerror(errno));
353 			}
354 			continue;
355 		}
356 
357 		/* packet reception */
358 #ifdef HAVE_POLL_H
359 		if (set[1].revents & POLLIN)
360 #else
361 		if (FD_ISSET(rtsock, selectfdp))
362 #endif
363 			rtsock_input(rtsock);
364 #ifdef HAVE_POLL_H
365 		if (set[0].revents & POLLIN)
366 #else
367 		if (FD_ISSET(s, selectfdp))
368 #endif
369 			rtsol_input(s);
370 	}
371 	/* NOTREACHED */
372 
373 	return 0;
374 }
375 
376 int
377 ifconfig(char *ifname)
378 {
379 	struct ifinfo *ifinfo;
380 	struct sockaddr_dl *sdl;
381 	int flags;
382 
383 	if ((sdl = if_nametosdl(ifname)) == NULL) {
384 		warnmsg(LOG_ERR, __func__,
385 		    "failed to get link layer information for %s", ifname);
386 		return(-1);
387 	}
388 	if (find_ifinfo(sdl->sdl_index)) {
389 		warnmsg(LOG_ERR, __func__,
390 		    "interface %s was already configured", ifname);
391 		free(sdl);
392 		return(-1);
393 	}
394 
395 	if ((ifinfo = malloc(sizeof(*ifinfo))) == NULL) {
396 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
397 		free(sdl);
398 		return(-1);
399 	}
400 	memset(ifinfo, 0, sizeof(*ifinfo));
401 	ifinfo->sdl = sdl;
402 
403 	strlcpy(ifinfo->ifname, ifname, sizeof(ifinfo->ifname));
404 
405 	/* construct a router solicitation message */
406 	if (make_packet(ifinfo))
407 		goto bad;
408 
409 	/* set link ID of this interface. */
410 #ifdef HAVE_SCOPELIB
411 	if (inet_zoneid(AF_INET6, 2, ifname, &ifinfo->linkid))
412 		goto bad;
413 #else
414 	/* XXX: assume interface IDs as link IDs */
415 	ifinfo->linkid = ifinfo->sdl->sdl_index;
416 #endif
417 
418 	/*
419 	 * check if the interface is available.
420 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
421 	 */
422 	ifinfo->mediareqok = 1;
423 	ifinfo->active = interface_status(ifinfo);
424 	if (!ifinfo->mediareqok) {
425 		/*
426 		 * probe routers periodically even if the link status
427 		 * does not change.
428 		 */
429 		ifinfo->probeinterval = PROBE_INTERVAL;
430 	}
431 
432 	/* activate interface: interface_up returns 0 on success */
433 	flags = interface_up(ifinfo->ifname);
434 	if (flags == 0)
435 		ifinfo->state = IFS_DELAY;
436 	else if (flags == IFS_TENTATIVE)
437 		ifinfo->state = IFS_TENTATIVE;
438 	else
439 		ifinfo->state = IFS_DOWN;
440 
441 	rtsol_timer_update(ifinfo);
442 
443 	/* link into chain */
444 	if (iflist)
445 		ifinfo->next = iflist;
446 	iflist = ifinfo;
447 
448 	return(0);
449 
450 bad:
451 	free(ifinfo->sdl);
452 	free(ifinfo);
453 	return(-1);
454 }
455 
456 void
457 iflist_init()
458 {
459 	struct ifinfo *ifi, *next;
460 
461 	for (ifi = iflist; ifi; ifi = next) {
462 		next = ifi->next;
463 		if (ifi->sdl)
464 			free(ifi->sdl);
465 		if (ifi->rs_data)
466 			free(ifi->rs_data);
467 		free(ifi);
468 		iflist = NULL;
469 	}
470 }
471 
472 #if 0
473 static int
474 ifreconfig(char *ifname)
475 {
476 	struct ifinfo *ifi, *prev;
477 	int rv;
478 
479 	prev = NULL;
480 	for (ifi = iflist; ifi; ifi = ifi->next) {
481 		if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
482 			break;
483 		prev = ifi;
484 	}
485 	prev->next = ifi->next;
486 
487 	rv = ifconfig(ifname);
488 
489 	/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
490 	if (ifi->rs_data)
491 		free(ifi->rs_data);
492 	free(ifi->sdl);
493 	free(ifi);
494 	return rv;
495 }
496 #endif
497 
498 struct ifinfo *
499 find_ifinfo(int ifindex)
500 {
501 	struct ifinfo *ifi;
502 
503 	for (ifi = iflist; ifi; ifi = ifi->next)
504 		if (ifi->sdl->sdl_index == ifindex)
505 			return(ifi);
506 	return(NULL);
507 }
508 
509 static int
510 make_packet(struct ifinfo *ifinfo)
511 {
512 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
513 	struct nd_router_solicit *rs;
514 	char *buf;
515 
516 	if ((lladdroptlen = lladdropt_length(ifinfo->sdl)) == 0) {
517 		warnmsg(LOG_INFO, __func__,
518 		    "link-layer address option has null length"
519 		    " on %s. Treat as not included.", ifinfo->ifname);
520 	}
521 	packlen += lladdroptlen;
522 	ifinfo->rs_datalen = packlen;
523 
524 	/* allocate buffer */
525 	if ((buf = malloc(packlen)) == NULL) {
526 		warnmsg(LOG_ERR, __func__,
527 		    "memory allocation failed for %s", ifinfo->ifname);
528 		return(-1);
529 	}
530 	ifinfo->rs_data = buf;
531 
532 	/* fill in the message */
533 	rs = (struct nd_router_solicit *)buf;
534 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
535 	rs->nd_rs_code = 0;
536 	rs->nd_rs_cksum = 0;
537 	rs->nd_rs_reserved = 0;
538 	buf += sizeof(*rs);
539 
540 	/* fill in source link-layer address option */
541 	if (lladdroptlen)
542 		lladdropt_fill(ifinfo->sdl, (struct nd_opt_hdr *)buf);
543 
544 	return(0);
545 }
546 
547 static struct timeval *
548 rtsol_check_timer()
549 {
550 	static struct timeval returnval;
551 	struct timeval now, rtsol_timer;
552 	struct ifinfo *ifinfo;
553 	int flags;
554 
555 	gettimeofday(&now, NULL);
556 
557 	rtsol_timer = tm_max;
558 
559 	for (ifinfo = iflist; ifinfo; ifinfo = ifinfo->next) {
560 		if (TIMEVAL_LEQ(ifinfo->expire, now)) {
561 			if (dflag > 1)
562 				warnmsg(LOG_DEBUG, __func__,
563 				    "timer expiration on %s, "
564 				    "state = %d", ifinfo->ifname,
565 				    ifinfo->state);
566 
567 			switch (ifinfo->state) {
568 			case IFS_DOWN:
569 			case IFS_TENTATIVE:
570 				/* interface_up returns 0 on success */
571 				flags = interface_up(ifinfo->ifname);
572 				if (flags == 0)
573 					ifinfo->state = IFS_DELAY;
574 				else if (flags == IFS_TENTATIVE)
575 					ifinfo->state = IFS_TENTATIVE;
576 				else
577 					ifinfo->state = IFS_DOWN;
578 				break;
579 			case IFS_IDLE:
580 			{
581 				int oldstatus = ifinfo->active;
582 				int probe = 0;
583 
584 				ifinfo->active = interface_status(ifinfo);
585 
586 				if (oldstatus != ifinfo->active) {
587 					warnmsg(LOG_DEBUG, __func__,
588 					    "%s status is changed"
589 					    " from %d to %d",
590 					    ifinfo->ifname,
591 					    oldstatus, ifinfo->active);
592 					probe = 1;
593 					ifinfo->state = IFS_DELAY;
594 				} else if (ifinfo->probeinterval &&
595 				    (ifinfo->probetimer -=
596 				    ifinfo->timer.tv_sec) <= 0) {
597 					/* probe timer expired */
598 					ifinfo->probetimer =
599 					    ifinfo->probeinterval;
600 					probe = 1;
601 					ifinfo->state = IFS_PROBE;
602 				}
603 
604 				/*
605 				 * If we need a probe, clear the previous
606 				 * status wrt the "other" configuration.
607 				 */
608 				if (probe)
609 					ifinfo->otherconfig = 0;
610 
611 				if (probe && mobile_node)
612 					defrouter_probe(ifinfo);
613 				break;
614 			}
615 			case IFS_DELAY:
616 				ifinfo->state = IFS_PROBE;
617 				sendpacket(ifinfo);
618 				break;
619 			case IFS_PROBE:
620 				if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
621 					sendpacket(ifinfo);
622 				else {
623 					warnmsg(LOG_INFO, __func__,
624 					    "No answer after sending %d RSs",
625 					    ifinfo->probes);
626 					ifinfo->probes = 0;
627 					ifinfo->state = IFS_IDLE;
628 				}
629 				break;
630 			}
631 			rtsol_timer_update(ifinfo);
632 		}
633 
634 		if (TIMEVAL_LT(ifinfo->expire, rtsol_timer))
635 			rtsol_timer = ifinfo->expire;
636 	}
637 
638 	if (TIMEVAL_EQ(rtsol_timer, tm_max)) {
639 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
640 		return(NULL);
641 	} else if (TIMEVAL_LT(rtsol_timer, now))
642 		/* this may occur when the interval is too small */
643 		returnval.tv_sec = returnval.tv_usec = 0;
644 	else
645 		TIMEVAL_SUB(&rtsol_timer, &now, &returnval);
646 
647 	if (dflag > 1)
648 		warnmsg(LOG_DEBUG, __func__, "New timer is %ld:%08ld",
649 		    (long)returnval.tv_sec, (long)returnval.tv_usec);
650 
651 	return(&returnval);
652 }
653 
654 void
655 rtsol_timer_update(struct ifinfo *ifinfo)
656 {
657 #define MILLION 1000000
658 #define DADRETRY 10		/* XXX: adhoc */
659 	long interval;
660 	struct timeval now;
661 
662 	bzero(&ifinfo->timer, sizeof(ifinfo->timer));
663 
664 	switch (ifinfo->state) {
665 	case IFS_DOWN:
666 	case IFS_TENTATIVE:
667 		if (++ifinfo->dadcount > DADRETRY) {
668 			ifinfo->dadcount = 0;
669 			ifinfo->timer.tv_sec = PROBE_INTERVAL;
670 		} else
671 			ifinfo->timer.tv_sec = 1;
672 		break;
673 	case IFS_IDLE:
674 		if (mobile_node) {
675 			/* XXX should be configurable */
676 			ifinfo->timer.tv_sec = 3;
677 		}
678 		else
679 			ifinfo->timer = tm_max;	/* stop timer(valid?) */
680 		break;
681 	case IFS_DELAY:
682 #ifndef HAVE_ARC4RANDOM
683 		interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
684 #else
685 		interval = arc4random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
686 #endif
687 		ifinfo->timer.tv_sec = interval / MILLION;
688 		ifinfo->timer.tv_usec = interval % MILLION;
689 		break;
690 	case IFS_PROBE:
691 		if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
692 			ifinfo->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
693 		else {
694 			/*
695 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
696 			 * we're just waiting for possible replies; there
697 			 * will be no more solicatation.  Thus, we change
698 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
699 			 * on RFC 2461, Section 6.3.7.
700 			 */
701 			ifinfo->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
702 		}
703 		break;
704 	default:
705 		warnmsg(LOG_ERR, __func__,
706 		    "illegal interface state(%d) on %s",
707 		    ifinfo->state, ifinfo->ifname);
708 		return;
709 	}
710 
711 	/* reset the timer */
712 	if (TIMEVAL_EQ(ifinfo->timer, tm_max)) {
713 		ifinfo->expire = tm_max;
714 		warnmsg(LOG_DEBUG, __func__,
715 		    "stop timer for %s", ifinfo->ifname);
716 	} else {
717 		gettimeofday(&now, NULL);
718 		TIMEVAL_ADD(&now, &ifinfo->timer, &ifinfo->expire);
719 
720 		if (dflag > 1)
721 			warnmsg(LOG_DEBUG, __func__,
722 			    "set timer for %s to %d:%d", ifinfo->ifname,
723 			    (int)ifinfo->timer.tv_sec,
724 			    (int)ifinfo->timer.tv_usec);
725 	}
726 
727 #undef MILLION
728 }
729 
730 /* timer related utility functions */
731 #define MILLION 1000000
732 
733 /* result = a + b */
734 static void
735 TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result)
736 {
737 	long l;
738 
739 	if ((l = a->tv_usec + b->tv_usec) < MILLION) {
740 		result->tv_usec = l;
741 		result->tv_sec = a->tv_sec + b->tv_sec;
742 	} else {
743 		result->tv_usec = l - MILLION;
744 		result->tv_sec = a->tv_sec + b->tv_sec + 1;
745 	}
746 }
747 
748 /*
749  * result = a - b
750  * XXX: this function assumes that a >= b.
751  */
752 void
753 TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result)
754 {
755 	long l;
756 
757 	if ((l = a->tv_usec - b->tv_usec) >= 0) {
758 		result->tv_usec = l;
759 		result->tv_sec = a->tv_sec - b->tv_sec;
760 	} else {
761 		result->tv_usec = MILLION + l;
762 		result->tv_sec = a->tv_sec - b->tv_sec - 1;
763 	}
764 }
765 
766 static void
767 rtsold_set_dump_file(sig)
768 	int sig;
769 {
770 	do_dump = 1;
771 }
772 
773 static void
774 usage(char *progname)
775 {
776 	if (progname && progname[strlen(progname) - 1] != 'd') {
777 		fprintf(stderr, "usage: rtsol [-dD] interfaces...\n");
778 		fprintf(stderr, "usage: rtsol [-dD] -a\n");
779 	} else {
780 		fprintf(stderr, "usage: rtsold [-adDfm1] interfaces...\n");
781 		fprintf(stderr, "usage: rtsold [-dDfm1] -a\n");
782 	}
783 	exit(1);
784 }
785 
786 void
787 #if __STDC__
788 warnmsg(int priority, const char *func, const char *msg, ...)
789 #else
790 warnmsg(priority, func, msg, va_alist)
791 	int priority;
792 	const char *func;
793 	const char *msg;
794 	va_dcl
795 #endif
796 {
797 	va_list ap;
798 	char buf[BUFSIZ];
799 
800 	va_start(ap, msg);
801 	if (fflag) {
802 		if (priority <= log_upto) {
803 			(void)vfprintf(stderr, msg, ap);
804 			(void)fprintf(stderr, "\n");
805 		}
806 	} else {
807 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
808 		msg = buf;
809 		vsyslog(priority, msg, ap);
810 	}
811 	va_end(ap);
812 }
813 
814 /*
815  * return a list of interfaces which is suitable to sending an RS.
816  */
817 char **
818 autoifprobe()
819 {
820 	static char **argv = NULL;
821 	static int n = 0;
822 	char **a;
823 	int i, found;
824 	struct ifaddrs *ifap, *ifa, *target;
825 
826 	/* initialize */
827 	while (n--)
828 		free(argv[n]);
829 	if (argv) {
830 		free(argv);
831 		argv = NULL;
832 	}
833 	n = 0;
834 
835 	if (getifaddrs(&ifap) != 0)
836 		return NULL;
837 
838 	target = NULL;
839 	/* find an ethernet */
840 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
841 		if ((ifa->ifa_flags & IFF_UP) == 0)
842 			continue;
843 		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
844 			continue;
845 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
846 			continue;
847 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
848 			continue;
849 
850 		if (ifa->ifa_addr->sa_family != AF_INET6)
851 			continue;
852 
853 		found = 0;
854 		for (i = 0; i < n; i++) {
855 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
856 				found++;
857 				break;
858 			}
859 		}
860 		if (found)
861 			continue;
862 
863 		/* if we find multiple candidates, just warn. */
864 		if (n != 0 && dflag > 1)
865 			warnx("multiple interfaces found");
866 
867 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
868 		if (a == NULL)
869 			err(1, "realloc");
870 		argv = a;
871 		argv[n] = strdup(ifa->ifa_name);
872 		if (!argv[n])
873 			err(1, "malloc");
874 		n++;
875 		argv[n] = NULL;
876 	}
877 
878 	if (n) {
879 		a = (char **)realloc(argv, (n + 1) * sizeof(char **));
880 		if (a == NULL)
881 			err(1, "realloc");
882 		argv = a;
883 		argv[n] = NULL;
884 
885 		if (dflag > 0) {
886 			for (i = 0; i < n; i++)
887 				warnx("probing %s", argv[i]);
888 		}
889 	}
890 	freeifaddrs(ifap);
891 	return argv;
892 }
893