rtsold.c revision 118916 
1/*	$KAME: rtsold.c,v 1.31 2001/05/22 06:03:06 jinmei 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: head/usr.sbin/rtsold/rtsold.c 118916 2003-08-14 18:43:57Z ume $
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
61struct ifinfo *iflist;
62struct timeval tm_max =	{0x7fffffff, 0x7fffffff};
63static int log_upto = 999;
64static int fflag = 0;
65
66int aflag = 0;
67int dflag = 0;
68
69char *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
96int main __P((int, char **));
97
98/* static variables and functions */
99static int mobile_node = 0;
100static int do_dump;
101static char *dumpfilename = "/var/run/rtsold.dump"; /* XXX: should be configurable */
102static char *pidfilename = "/var/run/rtsold.pid"; /* should be configurable */
103
104static int ifconfig __P((char *));
105#if 0
106static int ifreconfig __P((char *));
107#endif
108static int make_packet __P((struct ifinfo *));
109static struct timeval *rtsol_check_timer __P((void));
110static void TIMEVAL_ADD __P((struct timeval *, struct timeval *,
111	struct timeval *));
112static void TIMEVAL_SUB __P((struct timeval *, struct timeval *,
113	struct timeval *));
114
115static void rtsold_set_dump_file __P((int));
116static void usage __P((char *));
117static char **autoifprobe __P((void));
118
119int
120main(argc, argv)
121	int argc;
122	char **argv;
123{
124	int s, ch, once = 0;
125	struct timeval *timeout;
126	char *argv0, *opts;
127#ifdef HAVE_POLL_H
128	struct pollfd set[2];
129#else
130	fd_set *fdsetp, *selectfdp;
131	int fdmasks;
132	int maxfd;
133#endif
134	int rtsock;
135
136	/*
137	 * Initialization
138	 */
139	argv0 = argv[0];
140
141	/* get option */
142	if (argv0 && argv0[strlen(argv0) - 1] != 'd') {
143		fflag = 1;
144		once = 1;
145		opts = "adDO:";
146	} else
147		opts = "adDfm1O:";
148
149	while ((ch = getopt(argc, argv, opts)) != -1) {
150		switch (ch) {
151		case 'a':
152			aflag = 1;
153			break;
154		case 'd':
155			dflag = 1;
156			break;
157		case 'D':
158			dflag = 2;
159			break;
160		case 'f':
161			fflag = 1;
162			break;
163		case 'm':
164			mobile_node = 1;
165			break;
166		case '1':
167			once = 1;
168			break;
169		case 'O':
170			otherconf_script = optarg;
171			break;
172		default:
173			usage(argv0);
174			/*NOTREACHED*/
175		}
176	}
177	argc -= optind;
178	argv += optind;
179
180	if (aflag) {
181		int i;
182
183		if (argc != 0) {
184			usage(argv0);
185			/*NOTREACHED*/
186		}
187
188		argv = autoifprobe();
189		if (!argv) {
190			errx(1, "could not autoprobe interface");
191			/*NOTREACHED*/
192		}
193
194		for (i = 0; argv[i]; i++)
195			;
196		argc = i;
197	}
198	if (argc == 0) {
199		usage(argv0);
200		/*NOTREACHED*/
201	}
202
203	/* set log level */
204	if (dflag == 0)
205		log_upto = LOG_NOTICE;
206	if (!fflag) {
207		char *ident;
208
209		ident = strrchr(argv0, '/');
210		if (!ident)
211			ident = argv0;
212		else
213			ident++;
214		openlog(ident, LOG_NDELAY|LOG_PID, LOG_DAEMON);
215		if (log_upto >= 0)
216			setlogmask(LOG_UPTO(log_upto));
217	}
218
219	if (otherconf_script && *otherconf_script != '/') {
220		errx(1, "configuration script (%s) must be an absolute path",
221		    otherconf_script);
222	}
223
224#ifndef HAVE_ARC4RANDOM
225	/* random value initialization */
226	srandom((u_long)time(NULL));
227#endif
228
229	/* warn if accept_rtadv is down */
230	if (!getinet6sysctl(IPV6CTL_ACCEPT_RTADV))
231		warnx("kernel is configured not to accept RAs");
232	/* warn if forwarding is up */
233	if (getinet6sysctl(IPV6CTL_FORWARDING))
234		warnx("kernel is configured as a router, not a host");
235
236	/* initialization to dump internal status to a file */
237	signal(SIGUSR1, rtsold_set_dump_file);
238
239	if (!fflag)
240		daemon(0, 0);		/* act as a daemon */
241
242	/*
243	 * Open a socket for sending RS and receiving RA.
244	 * This should be done before calling ifinit(), since the function
245	 * uses the socket.
246	 */
247	if ((s = sockopen()) < 0) {
248		warnmsg(LOG_ERR, __func__, "failed to open a socket");
249		exit(1);
250		/*NOTREACHED*/
251	}
252#ifdef HAVE_POLL_H
253	set[0].fd = s;
254	set[0].events = POLLIN;
255#else
256	maxfd = s;
257#endif
258
259#ifdef HAVE_POLL_H
260	set[1].fd = -1;
261#endif
262
263	if ((rtsock = rtsock_open()) < 0) {
264		warnmsg(LOG_ERR, __func__, "failed to open a socket");
265		exit(1);
266		/*NOTREACHED*/
267	}
268#ifdef HAVE_POLL_H
269	set[1].fd = rtsock;
270	set[1].events = POLLIN;
271#else
272	if (rtsock > maxfd)
273		maxfd = rtsock;
274#endif
275
276#ifndef HAVE_POLL_H
277	fdmasks = howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask);
278	if ((fdsetp = malloc(fdmasks)) == NULL) {
279		err(1, "malloc");
280		/*NOTREACHED*/
281	}
282	if ((selectfdp = malloc(fdmasks)) == NULL) {
283		err(1, "malloc");
284		/*NOTREACHED*/
285	}
286#endif
287
288	/* configuration per interface */
289	if (ifinit()) {
290		warnmsg(LOG_ERR, __func__,
291		    "failed to initilizatoin interfaces");
292		exit(1);
293		/*NOTREACHED*/
294	}
295	while (argc--) {
296		if (ifconfig(*argv)) {
297			warnmsg(LOG_ERR, __func__,
298			    "failed to initialize %s", *argv);
299			exit(1);
300			/*NOTREACHED*/
301		}
302		argv++;
303	}
304
305	/* setup for probing default routers */
306	if (probe_init()) {
307		warnmsg(LOG_ERR, __func__,
308		    "failed to setup for probing routers");
309		exit(1);
310		/*NOTREACHED*/
311	}
312
313	/* dump the current pid */
314	if (!once) {
315		pid_t pid = getpid();
316		FILE *fp;
317
318		if ((fp = fopen(pidfilename, "w")) == NULL)
319			warnmsg(LOG_ERR, __func__,
320			    "failed to open a pid log file(%s): %s",
321			    pidfilename, strerror(errno));
322		else {
323			fprintf(fp, "%d\n", pid);
324			fclose(fp);
325		}
326	}
327
328#ifndef HAVE_POLL_H
329	memset(fdsetp, 0, fdmasks);
330	FD_SET(s, fdsetp);
331	FD_SET(rtsock, fdsetp);
332#endif
333	while (1) {		/* main loop */
334		int e;
335
336#ifndef HAVE_POLL_H
337		memcpy(selectfdp, fdsetp, fdmasks);
338#endif
339
340		if (do_dump) {	/* SIGUSR1 */
341			do_dump = 0;
342			rtsold_dump_file(dumpfilename);
343		}
344
345		timeout = rtsol_check_timer();
346
347		if (once) {
348			struct ifinfo *ifi;
349
350			/* if we have no timeout, we are done (or failed) */
351			if (timeout == NULL)
352				break;
353
354			/* if all interfaces have got RA packet, we are done */
355			for (ifi = iflist; ifi; ifi = ifi->next) {
356				if (ifi->state != IFS_DOWN && ifi->racnt == 0)
357					break;
358			}
359			if (ifi == NULL)
360				break;
361		}
362#ifdef HAVE_POLL_H
363		e = poll(set, 2, timeout ? (timeout->tv_sec * 1000 + timeout->tv_usec / 1000) : INFTIM);
364#else
365		e = select(maxfd + 1, selectfdp, NULL, NULL, timeout);
366#endif
367		if (e < 1) {
368			if (e < 0 && errno != EINTR) {
369				warnmsg(LOG_ERR, __func__, "select: %s",
370				    strerror(errno));
371			}
372			continue;
373		}
374
375		/* packet reception */
376#ifdef HAVE_POLL_H
377		if (set[1].revents & POLLIN)
378#else
379		if (FD_ISSET(rtsock, selectfdp))
380#endif
381			rtsock_input(rtsock);
382#ifdef HAVE_POLL_H
383		if (set[0].revents & POLLIN)
384#else
385		if (FD_ISSET(s, selectfdp))
386#endif
387			rtsol_input(s);
388	}
389	/* NOTREACHED */
390
391	return 0;
392}
393
394static int
395ifconfig(char *ifname)
396{
397	struct ifinfo *ifinfo;
398	struct sockaddr_dl *sdl;
399	int flags;
400
401	if ((sdl = if_nametosdl(ifname)) == NULL) {
402		warnmsg(LOG_ERR, __func__,
403		    "failed to get link layer information for %s", ifname);
404		return(-1);
405	}
406	if (find_ifinfo(sdl->sdl_index)) {
407		warnmsg(LOG_ERR, __func__,
408		    "interface %s was already configured", ifname);
409		free(sdl);
410		return(-1);
411	}
412
413	if ((ifinfo = malloc(sizeof(*ifinfo))) == NULL) {
414		warnmsg(LOG_ERR, __func__, "memory allocation failed");
415		free(sdl);
416		return(-1);
417	}
418	memset(ifinfo, 0, sizeof(*ifinfo));
419	ifinfo->sdl = sdl;
420
421	strlcpy(ifinfo->ifname, ifname, sizeof(ifinfo->ifname));
422
423	/* construct a router solicitation message */
424	if (make_packet(ifinfo))
425		goto bad;
426
427	/*
428	 * check if the interface is available.
429	 * also check if SIOCGIFMEDIA ioctl is OK on the interface.
430	 */
431	ifinfo->mediareqok = 1;
432	ifinfo->active = interface_status(ifinfo);
433	if (!ifinfo->mediareqok) {
434		/*
435		 * probe routers periodically even if the link status
436		 * does not change.
437		 */
438		ifinfo->probeinterval = PROBE_INTERVAL;
439	}
440
441	/* activate interface: interface_up returns 0 on success */
442	flags = interface_up(ifinfo->ifname);
443	if (flags == 0)
444		ifinfo->state = IFS_DELAY;
445	else if (flags == IFS_TENTATIVE)
446		ifinfo->state = IFS_TENTATIVE;
447	else
448		ifinfo->state = IFS_DOWN;
449
450	rtsol_timer_update(ifinfo);
451
452	/* link into chain */
453	if (iflist)
454		ifinfo->next = iflist;
455	iflist = ifinfo;
456
457	return(0);
458
459bad:
460	free(ifinfo->sdl);
461	free(ifinfo);
462	return(-1);
463}
464
465#if 0
466static int
467ifreconfig(char *ifname)
468{
469	struct ifinfo *ifi, *prev;
470	int rv;
471
472	prev = NULL;
473	for (ifi = iflist; ifi; ifi = ifi->next) {
474		if (strncmp(ifi->ifname, ifname, sizeof(ifi->ifname)) == 0)
475			break;
476		prev = ifi;
477	}
478	prev->next = ifi->next;
479
480	rv = ifconfig(ifname);
481
482	/* reclaim it after ifconfig() in case ifname is pointer inside ifi */
483	if (ifi->rs_data)
484		free(ifi->rs_data);
485	free(ifi->sdl);
486	free(ifi);
487	return rv;
488}
489#endif
490
491struct ifinfo *
492find_ifinfo(int ifindex)
493{
494	struct ifinfo *ifi;
495
496	for (ifi = iflist; ifi; ifi = ifi->next)
497		if (ifi->sdl->sdl_index == ifindex)
498			return(ifi);
499	return(NULL);
500}
501
502static int
503make_packet(struct ifinfo *ifinfo)
504{
505	size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0;
506	struct nd_router_solicit *rs;
507	char *buf;
508
509	if ((lladdroptlen = lladdropt_length(ifinfo->sdl)) == 0) {
510		warnmsg(LOG_INFO, __func__,
511		    "link-layer address option has null length"
512		    " on %s. Treat as not included.", ifinfo->ifname);
513	}
514	packlen += lladdroptlen;
515	ifinfo->rs_datalen = packlen;
516
517	/* allocate buffer */
518	if ((buf = malloc(packlen)) == NULL) {
519		warnmsg(LOG_ERR, __func__,
520		    "memory allocation failed for %s", ifinfo->ifname);
521		return(-1);
522	}
523	ifinfo->rs_data = buf;
524
525	/* fill in the message */
526	rs = (struct nd_router_solicit *)buf;
527	rs->nd_rs_type = ND_ROUTER_SOLICIT;
528	rs->nd_rs_code = 0;
529	rs->nd_rs_cksum = 0;
530	rs->nd_rs_reserved = 0;
531	buf += sizeof(*rs);
532
533	/* fill in source link-layer address option */
534	if (lladdroptlen)
535		lladdropt_fill(ifinfo->sdl, (struct nd_opt_hdr *)buf);
536
537	return(0);
538}
539
540static struct timeval *
541rtsol_check_timer()
542{
543	static struct timeval returnval;
544	struct timeval now, rtsol_timer;
545	struct ifinfo *ifinfo;
546	int flags;
547
548	gettimeofday(&now, NULL);
549
550	rtsol_timer = tm_max;
551
552	for (ifinfo = iflist; ifinfo; ifinfo = ifinfo->next) {
553		if (TIMEVAL_LEQ(ifinfo->expire, now)) {
554			if (dflag > 1)
555				warnmsg(LOG_DEBUG, __func__,
556				    "timer expiration on %s, "
557				    "state = %d", ifinfo->ifname,
558				    ifinfo->state);
559
560			switch (ifinfo->state) {
561			case IFS_DOWN:
562			case IFS_TENTATIVE:
563				/* interface_up returns 0 on success */
564				flags = interface_up(ifinfo->ifname);
565				if (flags == 0)
566					ifinfo->state = IFS_DELAY;
567				else if (flags == IFS_TENTATIVE)
568					ifinfo->state = IFS_TENTATIVE;
569				else
570					ifinfo->state = IFS_DOWN;
571				break;
572			case IFS_IDLE:
573			{
574				int oldstatus = ifinfo->active;
575				int probe = 0;
576
577				ifinfo->active = interface_status(ifinfo);
578
579				if (oldstatus != ifinfo->active) {
580					warnmsg(LOG_DEBUG, __func__,
581					    "%s status is changed"
582					    " from %d to %d",
583					    ifinfo->ifname,
584					    oldstatus, ifinfo->active);
585					probe = 1;
586					ifinfo->state = IFS_DELAY;
587				} else if (ifinfo->probeinterval &&
588				    (ifinfo->probetimer -=
589				    ifinfo->timer.tv_sec) <= 0) {
590					/* probe timer expired */
591					ifinfo->probetimer =
592					    ifinfo->probeinterval;
593					probe = 1;
594					ifinfo->state = IFS_PROBE;
595				}
596
597				/*
598				 * If we need a probe, clear the previous
599				 * status wrt the "other" configuration.
600				 */
601				if (probe)
602					ifinfo->otherconfig = 0;
603
604				if (probe && mobile_node)
605					defrouter_probe(ifinfo->sdl->sdl_index);
606				break;
607			}
608			case IFS_DELAY:
609				ifinfo->state = IFS_PROBE;
610				sendpacket(ifinfo);
611				break;
612			case IFS_PROBE:
613				if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
614					sendpacket(ifinfo);
615				else {
616					warnmsg(LOG_INFO, __func__,
617					    "No answer after sending %d RSs",
618					    ifinfo->probes);
619					ifinfo->probes = 0;
620					ifinfo->state = IFS_IDLE;
621				}
622				break;
623			}
624			rtsol_timer_update(ifinfo);
625		}
626
627		if (TIMEVAL_LT(ifinfo->expire, rtsol_timer))
628			rtsol_timer = ifinfo->expire;
629	}
630
631	if (TIMEVAL_EQ(rtsol_timer, tm_max)) {
632		warnmsg(LOG_DEBUG, __func__, "there is no timer");
633		return(NULL);
634	} else if (TIMEVAL_LT(rtsol_timer, now))
635		/* this may occur when the interval is too small */
636		returnval.tv_sec = returnval.tv_usec = 0;
637	else
638		TIMEVAL_SUB(&rtsol_timer, &now, &returnval);
639
640	if (dflag > 1)
641		warnmsg(LOG_DEBUG, __func__, "New timer is %ld:%08ld",
642		    (long)returnval.tv_sec, (long)returnval.tv_usec);
643
644	return(&returnval);
645}
646
647void
648rtsol_timer_update(struct ifinfo *ifinfo)
649{
650#define MILLION 1000000
651#define DADRETRY 10		/* XXX: adhoc */
652	long interval;
653	struct timeval now;
654
655	bzero(&ifinfo->timer, sizeof(ifinfo->timer));
656
657	switch (ifinfo->state) {
658	case IFS_DOWN:
659	case IFS_TENTATIVE:
660		if (++ifinfo->dadcount > DADRETRY) {
661			ifinfo->dadcount = 0;
662			ifinfo->timer.tv_sec = PROBE_INTERVAL;
663		} else
664			ifinfo->timer.tv_sec = 1;
665		break;
666	case IFS_IDLE:
667		if (mobile_node) {
668			/* XXX should be configurable */
669			ifinfo->timer.tv_sec = 3;
670		}
671		else
672			ifinfo->timer = tm_max;	/* stop timer(valid?) */
673		break;
674	case IFS_DELAY:
675#ifndef HAVE_ARC4RANDOM
676		interval = random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
677#else
678		interval = arc4random() % (MAX_RTR_SOLICITATION_DELAY * MILLION);
679#endif
680		ifinfo->timer.tv_sec = interval / MILLION;
681		ifinfo->timer.tv_usec = interval % MILLION;
682		break;
683	case IFS_PROBE:
684		if (ifinfo->probes < MAX_RTR_SOLICITATIONS)
685			ifinfo->timer.tv_sec = RTR_SOLICITATION_INTERVAL;
686		else {
687			/*
688			 * After sending MAX_RTR_SOLICITATIONS solicitations,
689			 * we're just waiting for possible replies; there
690			 * will be no more solicatation.  Thus, we change
691			 * the timer value to MAX_RTR_SOLICITATION_DELAY based
692			 * on RFC 2461, Section 6.3.7.
693			 */
694			ifinfo->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY;
695		}
696		break;
697	default:
698		warnmsg(LOG_ERR, __func__,
699		    "illegal interface state(%d) on %s",
700		    ifinfo->state, ifinfo->ifname);
701		return;
702	}
703
704	/* reset the timer */
705	if (TIMEVAL_EQ(ifinfo->timer, tm_max)) {
706		ifinfo->expire = tm_max;
707		warnmsg(LOG_DEBUG, __func__,
708		    "stop timer for %s", ifinfo->ifname);
709	} else {
710		gettimeofday(&now, NULL);
711		TIMEVAL_ADD(&now, &ifinfo->timer, &ifinfo->expire);
712
713		if (dflag > 1)
714			warnmsg(LOG_DEBUG, __func__,
715			    "set timer for %s to %d:%d", ifinfo->ifname,
716			    (int)ifinfo->timer.tv_sec,
717			    (int)ifinfo->timer.tv_usec);
718	}
719
720#undef MILLION
721}
722
723/* timer related utility functions */
724#define MILLION 1000000
725
726/* result = a + b */
727static void
728TIMEVAL_ADD(struct timeval *a, struct timeval *b, struct timeval *result)
729{
730	long l;
731
732	if ((l = a->tv_usec + b->tv_usec) < MILLION) {
733		result->tv_usec = l;
734		result->tv_sec = a->tv_sec + b->tv_sec;
735	} else {
736		result->tv_usec = l - MILLION;
737		result->tv_sec = a->tv_sec + b->tv_sec + 1;
738	}
739}
740
741/*
742 * result = a - b
743 * XXX: this function assumes that a >= b.
744 */
745void
746TIMEVAL_SUB(struct timeval *a, struct timeval *b, struct timeval *result)
747{
748	long l;
749
750	if ((l = a->tv_usec - b->tv_usec) >= 0) {
751		result->tv_usec = l;
752		result->tv_sec = a->tv_sec - b->tv_sec;
753	} else {
754		result->tv_usec = MILLION + l;
755		result->tv_sec = a->tv_sec - b->tv_sec - 1;
756	}
757}
758
759static void
760rtsold_set_dump_file(sig)
761	int sig;
762{
763	do_dump = 1;
764}
765
766static void
767usage(char *progname)
768{
769	if (progname && progname[strlen(progname) - 1] != 'd') {
770		fprintf(stderr, "usage: rtsol [-dD] interfaces...\n");
771		fprintf(stderr, "usage: rtsol [-dD] -a\n");
772	} else {
773		fprintf(stderr, "usage: rtsold [-adDfm1] interfaces...\n");
774		fprintf(stderr, "usage: rtsold [-dDfm1] -a\n");
775	}
776	exit(1);
777}
778
779void
780#if __STDC__
781warnmsg(int priority, const char *func, const char *msg, ...)
782#else
783warnmsg(priority, func, msg, va_alist)
784	int priority;
785	const char *func;
786	const char *msg;
787	va_dcl
788#endif
789{
790	va_list ap;
791	char buf[BUFSIZ];
792
793	va_start(ap, msg);
794	if (fflag) {
795		if (priority <= log_upto) {
796			(void)vfprintf(stderr, msg, ap);
797			(void)fprintf(stderr, "\n");
798		}
799	} else {
800		snprintf(buf, sizeof(buf), "<%s> %s", func, msg);
801		msg = buf;
802		vsyslog(priority, msg, ap);
803	}
804	va_end(ap);
805}
806
807static char **
808autoifprobe()
809{
810	static char ifname[IFNAMSIZ + 1];
811	static char *argv[2];
812	struct ifaddrs *ifap, *ifa, *target;
813
814	if (getifaddrs(&ifap) != 0)
815		return NULL;
816
817	target = NULL;
818	/* find an ethernet */
819	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
820		if ((ifa->ifa_flags & IFF_UP) == 0)
821			continue;
822		if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
823			continue;
824		if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
825			continue;
826		if ((ifa->ifa_flags & IFF_MULTICAST) == 0)
827			continue;
828
829		if (ifa->ifa_addr->sa_family != AF_INET6)
830			continue;
831
832		if (target && strcmp(target->ifa_name, ifa->ifa_name) == 0)
833			continue;
834
835		if (!target)
836			target = ifa;
837		else {
838			/* if we find multiple candidates, failure. */
839			if (dflag > 1)
840				warnx("multiple interfaces found");
841			target = NULL;
842			break;
843		}
844	}
845
846	if (target) {
847		strncpy(ifname, target->ifa_name, sizeof(ifname) - 1);
848		ifname[sizeof(ifname) - 1] = '\0';
849		argv[0] = ifname;
850		argv[1] = NULL;
851
852		if (dflag > 0)
853			warnx("probing %s", argv[0]);
854	}
855	freeifaddrs(ifap);
856	if (target)
857		return argv;
858	else
859		return (char **)NULL;
860}
861