xref: /freebsd/usr.sbin/rtsold/rtsold.c (revision 3e8eb5c7f4909209c042403ddee340b2ee7003a5)
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/capsicum.h>
38 #include <sys/event.h>
39 #include <sys/ioctl.h>
40 #include <sys/socket.h>
41 
42 #include <net/if.h>
43 #include <net/if_dl.h>
44 
45 #include <netinet/in.h>
46 #include <netinet/icmp6.h>
47 #include <netinet/in_var.h>
48 #include <arpa/inet.h>
49 
50 #include <netinet6/nd6.h>
51 
52 #include <capsicum_helpers.h>
53 #include <err.h>
54 #include <errno.h>
55 #include <ifaddrs.h>
56 #include <libgen.h>
57 #include <signal.h>
58 #include <stdarg.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <syslog.h>
63 #include <time.h>
64 #include <unistd.h>
65 
66 #include <libcasper.h>
67 #include <casper/cap_syslog.h>
68 #include <libutil.h>
69 
70 #include "rtsold.h"
71 
72 #define RTSOL_DUMPFILE	"/var/run/rtsold.dump"
73 
74 struct timespec tm_max;
75 static int log_upto = 999;
76 static int fflag = 0;
77 
78 int Fflag = 0;	/* force setting sysctl parameters */
79 int aflag = 0;
80 int dflag = 0;
81 int uflag = 0;
82 
83 const char *managedconf_script;
84 const char *otherconf_script;
85 const char *resolvconf_script = "/sbin/resolvconf";
86 
87 cap_channel_t *capllflags, *capscript, *capsendmsg, *capsyslog;
88 
89 /* protocol constants */
90 #define MAX_RTR_SOLICITATION_DELAY	1 /* second */
91 #define RTR_SOLICITATION_INTERVAL	4 /* seconds */
92 #define MAX_RTR_SOLICITATIONS		3 /* times */
93 
94 /*
95  * implementation dependent constants in seconds
96  * XXX: should be configurable
97  */
98 #define PROBE_INTERVAL 60
99 
100 /* static variables and functions */
101 static int mobile_node = 0;
102 static int no_solicitation_delay = 0;
103 
104 static sig_atomic_t do_dump, do_exit;
105 static struct pidfh *pfh;
106 
107 static char **autoifprobe(void);
108 static int ifconfig(char *ifname);
109 static int init_capabilities(void);
110 static int make_packet(struct ifinfo *);
111 static struct timespec *rtsol_check_timer(void);
112 
113 static void set_dumpfile(int);
114 static void set_exit(int);
115 static void usage(const char *progname);
116 
117 int
118 main(int argc, char **argv)
119 {
120 	struct kevent events[2];
121 	FILE *dumpfp;
122 	struct ifinfo *ifi;
123 	struct timespec *timeout;
124 	const char *opts, *pidfilepath, *progname;
125 	int ch, error, kq, once, rcvsock, rtsock;
126 
127 	progname = basename(argv[0]);
128 	if (strcmp(progname, "rtsold") == 0) {
129 		opts = "adDfFim1M:O:p:R:u";
130 		once = 0;
131 		pidfilepath = NULL;
132 	} else {
133 		opts = "adDFiM:O:R:u";
134 		fflag = 1;
135 		once = 1;
136 	}
137 
138 	while ((ch = getopt(argc, argv, opts)) != -1) {
139 		switch (ch) {
140 		case 'a':
141 			aflag = 1;
142 			break;
143 		case 'd':
144 			dflag += 1;
145 			break;
146 		case 'D':
147 			dflag += 2;
148 			break;
149 		case 'f':
150 			fflag = 1;
151 			break;
152 		case 'F':
153 			Fflag = 1;
154 			break;
155 		case 'i':
156 			no_solicitation_delay = 1;
157 			break;
158 		case 'm':
159 			mobile_node = 1;
160 			break;
161 		case '1':
162 			once = 1;
163 			break;
164 		case 'M':
165 			managedconf_script = optarg;
166 			break;
167 		case 'O':
168 			otherconf_script = optarg;
169 			break;
170 		case 'p':
171 			pidfilepath = optarg;
172 			break;
173 		case 'R':
174 			resolvconf_script = optarg;
175 			break;
176 		case 'u':
177 			uflag = 1;
178 			break;
179 		default:
180 			usage(progname);
181 		}
182 	}
183 	argc -= optind;
184 	argv += optind;
185 
186 	if ((!aflag && argc == 0) || (aflag && argc != 0))
187 		usage(progname);
188 
189 	/* Generate maximum time in timespec. */
190 	tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1));
191 	tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1));
192 
193 	/* set log level */
194 	if (dflag > 1)
195 		log_upto = LOG_DEBUG;
196 	else if (dflag > 0)
197 		log_upto = LOG_INFO;
198 	else
199 		log_upto = LOG_NOTICE;
200 
201 	if (managedconf_script != NULL && *managedconf_script != '/')
202 		errx(1, "configuration script (%s) must be an absolute path",
203 		    managedconf_script);
204 	if (otherconf_script != NULL && *otherconf_script != '/')
205 		errx(1, "configuration script (%s) must be an absolute path",
206 		    otherconf_script);
207 	if (*resolvconf_script != '/')
208 		errx(1, "configuration script (%s) must be an absolute path",
209 		    resolvconf_script);
210 
211 	if (!fflag) {
212 		pfh = pidfile_open(pidfilepath, 0644, NULL);
213 		if (pfh == NULL)
214 			errx(1, "failed to open pidfile: %s", strerror(errno));
215 		if (daemon(0, 0) != 0)
216 			errx(1, "failed to daemonize");
217 	}
218 
219 	if ((error = init_capabilities()) != 0)
220 		err(1, "failed to initialize capabilities");
221 
222 	if (!fflag) {
223 		cap_openlog(capsyslog, progname, LOG_NDELAY | LOG_PID,
224 		    LOG_DAEMON);
225 		if (log_upto >= 0)
226 			(void)cap_setlogmask(capsyslog, LOG_UPTO(log_upto));
227 		(void)signal(SIGTERM, set_exit);
228 		(void)signal(SIGINT, set_exit);
229 		(void)signal(SIGUSR1, set_dumpfile);
230 		dumpfp = rtsold_init_dumpfile(RTSOL_DUMPFILE);
231 	} else
232 		dumpfp = NULL;
233 
234 	kq = kqueue();
235 	if (kq < 0) {
236 		warnmsg(LOG_ERR, __func__, "failed to create a kqueue: %s",
237 		    strerror(errno));
238 		exit(1);
239 	}
240 
241 	/* Open global sockets and register for read events. */
242 	if ((rtsock = rtsock_open()) < 0) {
243 		warnmsg(LOG_ERR, __func__, "failed to open routing socket");
244 		exit(1);
245 	}
246 	if ((rcvsock = recvsockopen()) < 0) {
247 		warnmsg(LOG_ERR, __func__, "failed to open receive socket");
248 		exit(1);
249 	}
250 	EV_SET(&events[0], rtsock, EVFILT_READ, EV_ADD, 0, 0, NULL);
251 	EV_SET(&events[1], rcvsock, EVFILT_READ, EV_ADD, 0, 0, NULL);
252 	if (kevent(kq, events, 2, NULL, 0, NULL) < 0) {
253 		warnmsg(LOG_ERR, __func__, "kevent(): %s", strerror(errno));
254 		exit(1);
255 	}
256 
257 	/* Probe network interfaces and set up tracking info. */
258 	if (ifinit() != 0) {
259 		warnmsg(LOG_ERR, __func__, "failed to initialize interfaces");
260 		exit(1);
261 	}
262 	if (aflag)
263 		argv = autoifprobe();
264 	while (argv && *argv) {
265 		if (ifconfig(*argv)) {
266 			warnmsg(LOG_ERR, __func__,
267 			    "failed to initialize %s", *argv);
268 			exit(1);
269 		}
270 		argv++;
271 	}
272 
273 	/* Write to our pidfile. */
274 	if (pfh != NULL && pidfile_write(pfh) != 0) {
275 		warnmsg(LOG_ERR, __func__,
276 		    "failed to open pidfile: %s", strerror(errno));
277 		exit(1);
278 	}
279 
280 	/* Enter capability mode. */
281 	caph_cache_catpages();
282 	if (caph_enter_casper() != 0) {
283 		warnmsg(LOG_ERR, __func__, "caph_enter(): %s", strerror(errno));
284 		exit(1);
285 	}
286 
287 	for (;;) {
288 		if (do_exit) {
289 			/* Handle SIGTERM, SIGINT. */
290 			if (pfh != NULL)
291 				pidfile_remove(pfh);
292 			break;
293 		}
294 		if (do_dump) {
295 			/* Handle SIGUSR1. */
296 			do_dump = 0;
297 			if (dumpfp != NULL)
298 				rtsold_dump(dumpfp);
299 		}
300 
301 		timeout = rtsol_check_timer();
302 
303 		if (once) {
304 			/* if we have no timeout, we are done (or failed) */
305 			if (timeout == NULL)
306 				break;
307 
308 			/* if all interfaces have got RA packet, we are done */
309 			TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
310 				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
311 					break;
312 			}
313 			if (ifi == NULL)
314 				break;
315 		}
316 
317 		error = kevent(kq, NULL, 0, &events[0], 1, timeout);
318 		if (error < 1) {
319 			if (error < 0 && errno != EINTR)
320 				warnmsg(LOG_ERR, __func__, "kevent(): %s",
321 				    strerror(errno));
322 			continue;
323 		}
324 
325 		if (events[0].ident == (uintptr_t)rtsock)
326 			rtsock_input(rtsock);
327 		else
328 			rtsol_input(rcvsock);
329 	}
330 
331 	return (0);
332 }
333 
334 static int
335 init_capabilities(void)
336 {
337 #ifdef WITH_CASPER
338 	const char *const scripts[] =
339 	    { resolvconf_script, managedconf_script, otherconf_script };
340 	cap_channel_t *capcasper;
341 	nvlist_t *limits;
342 
343 	capcasper = cap_init();
344 	if (capcasper == NULL)
345 		return (-1);
346 
347 	capllflags = cap_service_open(capcasper, "rtsold.llflags");
348 	if (capllflags == NULL)
349 		return (-1);
350 
351 	capscript = cap_service_open(capcasper, "rtsold.script");
352 	if (capscript == NULL)
353 		return (-1);
354 	limits = nvlist_create(0);
355 	for (size_t i = 0; i < nitems(scripts); i++)
356 		if (scripts[i] != NULL)
357 			nvlist_append_string_array(limits, "scripts",
358 			    scripts[i]);
359 	if (cap_limit_set(capscript, limits) != 0)
360 		return (-1);
361 
362 	capsendmsg = cap_service_open(capcasper, "rtsold.sendmsg");
363 	if (capsendmsg == NULL)
364 		return (-1);
365 
366 	if (!fflag) {
367 		capsyslog = cap_service_open(capcasper, "system.syslog");
368 		if (capsyslog == NULL)
369 			return (-1);
370 	}
371 
372 	cap_close(capcasper);
373 #endif /* WITH_CASPER */
374 	return (0);
375 }
376 
377 static int
378 ifconfig(char *ifname)
379 {
380 	struct ifinfo *ifi;
381 	struct sockaddr_dl *sdl;
382 	int flags;
383 
384 	ifi = NULL;
385 	if ((sdl = if_nametosdl(ifname)) == NULL) {
386 		warnmsg(LOG_ERR, __func__,
387 		    "failed to get link layer information for %s", ifname);
388 		goto bad;
389 	}
390 	if (find_ifinfo(sdl->sdl_index)) {
391 		warnmsg(LOG_ERR, __func__,
392 		    "interface %s was already configured", ifname);
393 		goto bad;
394 	}
395 
396 	if (Fflag) {
397 		struct in6_ndireq nd;
398 		int s;
399 
400 		if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
401 			warnmsg(LOG_ERR, __func__, "socket() failed.");
402 			goto bad;
403 		}
404 		memset(&nd, 0, sizeof(nd));
405 		strlcpy(nd.ifname, ifname, sizeof(nd.ifname));
406 		if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
407 			warnmsg(LOG_ERR, __func__,
408 			    "cannot get accept_rtadv flag");
409 			(void)close(s);
410 			goto bad;
411 		}
412 		nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV;
413 		if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) {
414 			warnmsg(LOG_ERR, __func__,
415 			    "cannot set accept_rtadv flag");
416 			(void)close(s);
417 			goto bad;
418 		}
419 		(void)close(s);
420 	}
421 
422 	if ((ifi = malloc(sizeof(*ifi))) == NULL) {
423 		warnmsg(LOG_ERR, __func__, "memory allocation failed");
424 		goto bad;
425 	}
426 	memset(ifi, 0, sizeof(*ifi));
427 	ifi->sdl = sdl;
428 	ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
429 	ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
430 	TAILQ_INIT(&ifi->ifi_rainfo);
431 	strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname));
432 
433 	/* construct a router solicitation message */
434 	if (make_packet(ifi))
435 		goto bad;
436 
437 	/* set link ID of this interface. */
438 #ifdef HAVE_SCOPELIB
439 	if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid))
440 		goto bad;
441 #else
442 	/* XXX: assume interface IDs as link IDs */
443 	ifi->linkid = ifi->sdl->sdl_index;
444 #endif
445 
446 	/*
447 	 * check if the interface is available.
448 	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
449 	 */
450 	ifi->mediareqok = 1;
451 	ifi->active = interface_status(ifi);
452 	if (!ifi->mediareqok) {
453 		/*
454 		 * probe routers periodically even if the link status
455 		 * does not change.
456 		 */
457 		ifi->probeinterval = PROBE_INTERVAL;
458 	}
459 
460 	/* activate interface: interface_up returns 0 on success */
461 	flags = interface_up(ifi->ifname);
462 	if (flags == 0)
463 		ifi->state = IFS_DELAY;
464 	else if (flags == IFS_TENTATIVE)
465 		ifi->state = IFS_TENTATIVE;
466 	else
467 		ifi->state = IFS_DOWN;
468 
469 	rtsol_timer_update(ifi);
470 
471 	TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next);
472 	return (0);
473 
474 bad:
475 	free(sdl);
476 	free(ifi);
477 	return (-1);
478 }
479 
480 struct rainfo *
481 find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6)
482 {
483 	struct rainfo *rai;
484 
485 	TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next)
486 		if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr,
487 		    sizeof(rai->rai_saddr.sin6_addr)) == 0)
488 			return (rai);
489 
490 	return (NULL);
491 }
492 
493 struct ifinfo *
494 find_ifinfo(int ifindex)
495 {
496 	struct ifinfo *ifi;
497 
498 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
499 		if (ifi->sdl->sdl_index == ifindex)
500 			return (ifi);
501 	}
502 	return (NULL);
503 }
504 
505 static int
506 make_packet(struct ifinfo *ifi)
507 {
508 	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
509 	struct nd_router_solicit *rs;
510 	char *buf;
511 
512 	if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) {
513 		warnmsg(LOG_INFO, __func__,
514 		    "link-layer address option has null length"
515 		    " on %s. Treat as not included.", ifi->ifname);
516 	}
517 	packlen += lladdroptlen;
518 	ifi->rs_datalen = packlen;
519 
520 	/* allocate buffer */
521 	if ((buf = malloc(packlen)) == NULL) {
522 		warnmsg(LOG_ERR, __func__,
523 		    "memory allocation failed for %s", ifi->ifname);
524 		return (-1);
525 	}
526 	ifi->rs_data = buf;
527 
528 	/* fill in the message */
529 	rs = (struct nd_router_solicit *)buf;
530 	rs->nd_rs_type = ND_ROUTER_SOLICIT;
531 	rs->nd_rs_code = 0;
532 	rs->nd_rs_cksum = 0;
533 	rs->nd_rs_reserved = 0;
534 	buf += sizeof(*rs);
535 
536 	/* fill in source link-layer address option */
537 	if (lladdroptlen)
538 		lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf);
539 
540 	return (0);
541 }
542 
543 static struct timespec *
544 rtsol_check_timer(void)
545 {
546 	static struct timespec returnval;
547 	struct timespec now, rtsol_timer;
548 	struct ifinfo *ifi;
549 	struct rainfo *rai;
550 	struct ra_opt *rao, *raotmp;
551 	int error, flags;
552 
553 	clock_gettime(CLOCK_MONOTONIC_FAST, &now);
554 
555 	rtsol_timer = tm_max;
556 
557 	TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) {
558 		if (TS_CMP(&ifi->expire, &now, <=)) {
559 			warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, "
560 			    "state = %d", ifi->ifname, ifi->state);
561 
562 			while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) {
563 				/* Remove all RA options. */
564 				TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next);
565 				while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) !=
566 				    NULL) {
567 					TAILQ_REMOVE(&rai->rai_ra_opt, rao,
568 					    rao_next);
569 					if (rao->rao_msg != NULL)
570 						free(rao->rao_msg);
571 					free(rao);
572 				}
573 				free(rai);
574 			}
575 			switch (ifi->state) {
576 			case IFS_DOWN:
577 			case IFS_TENTATIVE:
578 				/* interface_up returns 0 on success */
579 				flags = interface_up(ifi->ifname);
580 				if (flags == 0)
581 					ifi->state = IFS_DELAY;
582 				else if (flags == IFS_TENTATIVE)
583 					ifi->state = IFS_TENTATIVE;
584 				else
585 					ifi->state = IFS_DOWN;
586 				break;
587 			case IFS_IDLE:
588 			{
589 				int oldstatus = ifi->active;
590 				int probe = 0;
591 
592 				ifi->active = interface_status(ifi);
593 
594 				if (oldstatus != ifi->active) {
595 					warnmsg(LOG_DEBUG, __func__,
596 					    "%s status is changed"
597 					    " from %d to %d",
598 					    ifi->ifname,
599 					    oldstatus, ifi->active);
600 					probe = 1;
601 					ifi->state = IFS_DELAY;
602 				} else if (ifi->probeinterval &&
603 				    (ifi->probetimer -=
604 				    ifi->timer.tv_sec) <= 0) {
605 					/* probe timer expired */
606 					ifi->probetimer =
607 					    ifi->probeinterval;
608 					probe = 1;
609 					ifi->state = IFS_PROBE;
610 				}
611 
612 				/*
613 				 * If we need a probe, clear the previous
614 				 * status wrt the "managed/other" configuration.
615 				 */
616 				if (probe) {
617 					ifi->managedconfig = 0;
618 					ifi->otherconfig = 0;
619 				}
620 				if (probe && mobile_node) {
621 					error = cap_probe_defrouters(capsendmsg,
622 					    ifi);
623 					if (error != 0)
624 						warnmsg(LOG_DEBUG, __func__,
625 					    "failed to probe routers: %d",
626 						    error);
627 				}
628 				break;
629 			}
630 			case IFS_DELAY:
631 				ifi->state = IFS_PROBE;
632 				(void)cap_rssend(capsendmsg, ifi);
633 				break;
634 			case IFS_PROBE:
635 				if (ifi->probes < MAX_RTR_SOLICITATIONS)
636 					(void)cap_rssend(capsendmsg, ifi);
637 				else {
638 					warnmsg(LOG_INFO, __func__,
639 					    "No answer after sending %d RSs",
640 					    ifi->probes);
641 					ifi->probes = 0;
642 					ifi->state = IFS_IDLE;
643 				}
644 				break;
645 			}
646 			rtsol_timer_update(ifi);
647 		} else {
648 			/* Expiration check for RA options. */
649 			int expire = 0;
650 
651 			TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
652 				TAILQ_FOREACH_SAFE(rao, &rai->rai_ra_opt,
653 				    rao_next, raotmp) {
654 					warnmsg(LOG_DEBUG, __func__,
655 					    "RA expiration timer: "
656 					    "type=%d, msg=%s, expire=%s",
657 					    rao->rao_type, (char *)rao->rao_msg,
658 						sec2str(&rao->rao_expire));
659 					if (TS_CMP(&now, &rao->rao_expire,
660 					    >=)) {
661 						warnmsg(LOG_DEBUG, __func__,
662 						    "RA expiration timer: "
663 						    "expired.");
664 						TAILQ_REMOVE(&rai->rai_ra_opt,
665 						    rao, rao_next);
666 						if (rao->rao_msg != NULL)
667 							free(rao->rao_msg);
668 						free(rao);
669 						expire = 1;
670 					}
671 				}
672 			}
673 			if (expire)
674 				ra_opt_handler(ifi);
675 		}
676 		if (TS_CMP(&ifi->expire, &rtsol_timer, <))
677 			rtsol_timer = ifi->expire;
678 	}
679 
680 	if (TS_CMP(&rtsol_timer, &tm_max, ==)) {
681 		warnmsg(LOG_DEBUG, __func__, "there is no timer");
682 		return (NULL);
683 	} else if (TS_CMP(&rtsol_timer, &now, <))
684 		/* this may occur when the interval is too small */
685 		returnval.tv_sec = returnval.tv_nsec = 0;
686 	else
687 		TS_SUB(&rtsol_timer, &now, &returnval);
688 
689 	now.tv_sec += returnval.tv_sec;
690 	now.tv_nsec += returnval.tv_nsec;
691 	warnmsg(LOG_DEBUG, __func__, "New timer is %s",
692 	    sec2str(&now));
693 
694 	return (&returnval);
695 }
696 
697 void
698 rtsol_timer_update(struct ifinfo *ifi)
699 {
700 #define MILLION 1000000
701 #define DADRETRY 10		/* XXX: adhoc */
702 	long interval;
703 	struct timespec now;
704 
705 	bzero(&ifi->timer, sizeof(ifi->timer));
706 
707 	switch (ifi->state) {
708 	case IFS_DOWN:
709 	case IFS_TENTATIVE:
710 		if (++ifi->dadcount > DADRETRY) {
711 			ifi->dadcount = 0;
712 			ifi->timer.tv_sec = PROBE_INTERVAL;
713 		} else
714 			ifi->timer.tv_sec = 1;
715 		break;
716 	case IFS_IDLE:
717 		if (mobile_node)
718 			/* XXX should be configurable */
719 			ifi->timer.tv_sec = 3;
720 		else
721 			ifi->timer = tm_max;	/* stop timer(valid?) */
722 		break;
723 	case IFS_DELAY:
724 		if (no_solicitation_delay)
725 			interval = 0;
726 		else
727 			interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION);
728 		ifi->timer.tv_sec = interval / MILLION;
729 		ifi->timer.tv_nsec = (interval % MILLION) * 1000;
730 		break;
731 	case IFS_PROBE:
732 		if (ifi->probes < MAX_RTR_SOLICITATIONS)
733 			ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
734 		else
735 			/*
736 			 * After sending MAX_RTR_SOLICITATIONS solicitations,
737 			 * we're just waiting for possible replies; there
738 			 * will be no more solicitation.  Thus, we change
739 			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
740 			 * on RFC 2461, Section 6.3.7.
741 			 */
742 			ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
743 		break;
744 	default:
745 		warnmsg(LOG_ERR, __func__,
746 		    "illegal interface state(%d) on %s",
747 		    ifi->state, ifi->ifname);
748 		return;
749 	}
750 
751 	/* reset the timer */
752 	if (TS_CMP(&ifi->timer, &tm_max, ==)) {
753 		ifi->expire = tm_max;
754 		warnmsg(LOG_DEBUG, __func__,
755 		    "stop timer for %s", ifi->ifname);
756 	} else {
757 		clock_gettime(CLOCK_MONOTONIC_FAST, &now);
758 		TS_ADD(&now, &ifi->timer, &ifi->expire);
759 
760 		now.tv_sec += ifi->timer.tv_sec;
761 		now.tv_nsec += ifi->timer.tv_nsec;
762 		warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s",
763 		    ifi->ifname, sec2str(&now));
764 	}
765 
766 #undef MILLION
767 }
768 
769 static void
770 set_dumpfile(int sig __unused)
771 {
772 
773 	do_dump = 1;
774 }
775 
776 static void
777 set_exit(int sig __unused)
778 {
779 
780 	do_exit = 1;
781 }
782 
783 static void
784 usage(const char *progname)
785 {
786 
787 	if (strcmp(progname, "rtsold") == 0) {
788 		fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
789 		    "[-p pidfile] [-R script-name] interface ...\n");
790 		fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] "
791 		    "[-p pidfile] [-R script-name] -a\n");
792 	} else {
793 		fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
794 		    "[-p pidfile] [-R script-name] interface ...\n");
795 		fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] "
796 		    "[-p pidfile] [-R script-name] -a\n");
797 	}
798 	exit(1);
799 }
800 
801 void
802 warnmsg(int priority, const char *func, const char *msg, ...)
803 {
804 	va_list ap;
805 	char buf[BUFSIZ];
806 
807 	va_start(ap, msg);
808 	if (fflag) {
809 		if (priority <= log_upto)
810 			vwarnx(msg, ap);
811 	} else {
812 		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
813 		msg = buf;
814 		cap_vsyslog(capsyslog, priority, msg, ap);
815 	}
816 	va_end(ap);
817 }
818 
819 /*
820  * return a list of interfaces which is suitable to sending an RS.
821  */
822 static char **
823 autoifprobe(void)
824 {
825 	static char **argv = NULL;
826 	static int n = 0;
827 	char **a;
828 	int s = 0, i, found;
829 	struct ifaddrs *ifap, *ifa;
830 	struct in6_ndireq nd;
831 
832 	/* initialize */
833 	while (n--)
834 		free(argv[n]);
835 	if (argv) {
836 		free(argv);
837 		argv = NULL;
838 	}
839 	n = 0;
840 
841 	if (getifaddrs(&ifap) != 0)
842 		return (NULL);
843 
844 	if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
845 		warnmsg(LOG_ERR, __func__, "socket");
846 		exit(1);
847 	}
848 
849 	/* find an ethernet */
850 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
851 		if ((ifa->ifa_flags & IFF_UP) == 0)
852 			continue;
853 		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
854 			continue;
855 		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
856 			continue;
857 
858 		if (ifa->ifa_addr->sa_family != AF_INET6)
859 			continue;
860 
861 		found = 0;
862 		for (i = 0; i < n; i++) {
863 			if (strcmp(argv[i], ifa->ifa_name) == 0) {
864 				found++;
865 				break;
866 			}
867 		}
868 		if (found)
869 			continue;
870 
871 		/*
872 		 * Skip the interfaces which IPv6 and/or accepting RA
873 		 * is disabled.
874 		 */
875 		if (!Fflag) {
876 			memset(&nd, 0, sizeof(nd));
877 			strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname));
878 			if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) {
879 				warnmsg(LOG_ERR, __func__,
880 					"ioctl(SIOCGIFINFO_IN6)");
881 				exit(1);
882 			}
883 			if ((nd.ndi.flags & ND6_IFF_IFDISABLED))
884 				continue;
885 			if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV))
886 				continue;
887 		}
888 
889 		/* if we find multiple candidates, just warn. */
890 		if (n != 0 && dflag > 1)
891 			warnmsg(LOG_WARNING, __func__,
892 				"multiple interfaces found");
893 
894 		a = realloc(argv, (n + 1) * sizeof(char *));
895 		if (a == NULL) {
896 			warnmsg(LOG_ERR, __func__, "realloc");
897 			exit(1);
898 		}
899 		argv = a;
900 		argv[n] = strdup(ifa->ifa_name);
901 		if (!argv[n]) {
902 			warnmsg(LOG_ERR, __func__, "malloc");
903 			exit(1);
904 		}
905 		n++;
906 	}
907 
908 	if (n) {
909 		a = realloc(argv, (n + 1) * sizeof(char *));
910 		if (a == NULL) {
911 			warnmsg(LOG_ERR, __func__, "realloc");
912 			exit(1);
913 		}
914 		argv = a;
915 		argv[n] = NULL;
916 
917 		if (dflag > 0) {
918 			for (i = 0; i < n; i++)
919 				warnmsg(LOG_WARNING, __func__, "probing %s",
920 					argv[i]);
921 		}
922 	}
923 	if (!Fflag)
924 		close(s);
925 	freeifaddrs(ifap);
926 	return (argv);
927 }
928