xref: /netbsd-src/usr.sbin/faithd/faithd.c (revision 6fc217346bb51c463d3a5a2a7883cb56515cd6d7)
1 /*	$NetBSD: faithd.c,v 1.32 2007/12/15 16:32:07 perry Exp $	*/
2 /*	$KAME: faithd.c,v 1.62 2003/08/19 21:20:33 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1997 and 1998 WIDE Project.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the project nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * User level translator from IPv6 to IPv4.
35  *
36  * Usage: faithd [<port> <progpath> <arg1(progname)> <arg2> ...]
37  *   e.g. faithd telnet /usr/local/v6/sbin/telnetd telnetd
38  */
39 
40 #include <sys/cdefs.h>
41 #include <sys/param.h>
42 #include <sys/types.h>
43 #include <sys/sysctl.h>
44 #include <sys/socket.h>
45 #include <sys/wait.h>
46 #include <sys/stat.h>
47 #include <sys/time.h>
48 #include <sys/ioctl.h>
49 
50 #include <poll.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <stdarg.h>
54 #include <string.h>
55 #include <syslog.h>
56 #include <unistd.h>
57 #include <errno.h>
58 #include <signal.h>
59 #include <fcntl.h>
60 #include <termios.h>
61 
62 #include <net/if_types.h>
63 #ifdef IFT_FAITH
64 # define USE_ROUTE
65 # include <net/if.h>
66 # include <net/route.h>
67 # include <net/if_dl.h>
68 #endif
69 
70 #include <netinet/in.h>
71 #include <arpa/inet.h>
72 #include <netdb.h>
73 #include <ifaddrs.h>
74 
75 #include "faithd.h"
76 #include "prefix.h"
77 
78 char *serverpath = NULL;
79 char *serverarg[MAXARGV + 1];
80 static char *faithdname = NULL;
81 char logname[BUFSIZ];
82 char procname[BUFSIZ];
83 struct myaddrs {
84 	struct myaddrs *next;
85 	struct sockaddr *addr;
86 };
87 struct myaddrs *myaddrs = NULL;
88 static const char *service;
89 #ifdef USE_ROUTE
90 static int sockfd = 0;
91 #endif
92 int dflag = 0;
93 static int pflag = 0;
94 static int inetd = 0;
95 static char *configfile = NULL;
96 
97 int main __P((int, char **));
98 static int inetd_main __P((int, char **));
99 static int daemon_main __P((int, char **));
100 static void play_service __P((int));
101 static void play_child __P((int, struct sockaddr *));
102 static int faith_prefix __P((struct sockaddr *));
103 static int map6to4 __P((struct sockaddr_in6 *, struct sockaddr_in *));
104 static void sig_child __P((int));
105 static void sig_terminate __P((int));
106 static void start_daemon __P((void));
107 static void exit_stderr __P((const char *, ...))
108 	__attribute__((__format__(__printf__, 1, 2)));
109 static void grab_myaddrs __P((void));
110 static void free_myaddrs __P((void));
111 static void update_myaddrs __P((void));
112 static void usage __P((void));
113 
114 int
115 main(int argc, char **argv)
116 {
117 
118 	/*
119 	 * Initializing stuff
120 	 */
121 
122 	faithdname = strrchr(argv[0], '/');
123 	if (faithdname)
124 		faithdname++;
125 	else
126 		faithdname = argv[0];
127 
128 	if (strcmp(faithdname, "faithd") != 0) {
129 		inetd = 1;
130 		return inetd_main(argc, argv);
131 	} else
132 		return daemon_main(argc, argv);
133 }
134 
135 static int
136 inetd_main(int argc, char **argv)
137 {
138 	char path[MAXPATHLEN];
139 	struct sockaddr_storage me;
140 	struct sockaddr_storage from;
141 	socklen_t melen, fromlen;
142 	int i;
143 	int error;
144 	const int on = 1;
145 	char sbuf[NI_MAXSERV], snum[NI_MAXSERV];
146 
147 	if (config_load(configfile) < 0 && configfile) {
148 		exit_failure("could not load config file");
149 		/*NOTREACHED*/
150 	}
151 
152 	if (strrchr(argv[0], '/') == NULL)
153 		snprintf(path, sizeof(path), "%s/%s", DEFAULT_DIR, argv[0]);
154 	else
155 		snprintf(path, sizeof(path), "%s", argv[0]);
156 
157 #ifdef USE_ROUTE
158 	grab_myaddrs();
159 
160 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
161 	if (sockfd < 0) {
162 		exit_failure("socket(PF_ROUTE): %s", strerror(errno));
163 		/*NOTREACHED*/
164 	}
165 #endif
166 
167 	melen = sizeof(me);
168 	if (getsockname(STDIN_FILENO, (struct sockaddr *)&me, &melen) < 0) {
169 		exit_failure("getsockname: %s", strerror(errno));
170 		/*NOTREACHED*/
171 	}
172 	fromlen = sizeof(from);
173 	if (getpeername(STDIN_FILENO, (struct sockaddr *)&from, &fromlen) < 0) {
174 		exit_failure("getpeername: %s", strerror(errno));
175 		/*NOTREACHED*/
176 	}
177 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
178 	    sbuf, sizeof(sbuf), NI_NUMERICHOST) == 0)
179 		service = sbuf;
180 	else
181 		service = DEFAULT_PORT_NAME;
182 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
183 	    snum, sizeof(snum), NI_NUMERICHOST) != 0)
184 		snprintf(snum, sizeof(snum), "?");
185 
186 	snprintf(logname, sizeof(logname), "faithd %s", snum);
187 	snprintf(procname, sizeof(procname), "accepting port %s", snum);
188 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
189 
190 	if (argc >= MAXARGV) {
191 		exit_failure("too many arguments");
192 		/*NOTREACHED*/
193 	}
194 	serverarg[0] = serverpath = path;
195 	for (i = 1; i < argc; i++)
196 		serverarg[i] = argv[i];
197 	serverarg[i] = NULL;
198 
199 	error = setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &on,
200 	    sizeof(on));
201 	if (error < 0) {
202 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
203 		/*NOTREACHED*/
204 	}
205 
206 	play_child(STDIN_FILENO, (struct sockaddr *)&from);
207 	exit_failure("should not reach here");
208 	return 0;	/*dummy!*/
209 }
210 
211 static int
212 daemon_main(int argc, char **argv)
213 {
214 	struct addrinfo hints, *res;
215 	int s_wld, error, i, serverargc, on = 1;
216 	int family = AF_INET6;
217 	int c;
218 
219 	while ((c = getopt(argc, argv, "df:p")) != -1) {
220 		switch (c) {
221 		case 'd':
222 			dflag++;
223 			break;
224 		case 'f':
225 			configfile = optarg;
226 			break;
227 		case 'p':
228 			pflag++;
229 			break;
230 		default:
231 			usage();
232 			/*NOTREACHED*/
233 		}
234 	}
235 	argc -= optind;
236 	argv += optind;
237 
238 	if (config_load(configfile) < 0 && configfile) {
239 		exit_failure("could not load config file");
240 		/*NOTREACHED*/
241 	}
242 
243 
244 #ifdef USE_ROUTE
245 	grab_myaddrs();
246 #endif
247 
248 	switch (argc) {
249 	case 0:
250 		usage();
251 		/*NOTREACHED*/
252 	default:
253 		serverargc = argc - NUMARG;
254 		if (serverargc >= MAXARGV)
255 			exit_stderr("too many arguments");
256 
257 		serverpath = strdup(argv[NUMPRG]);
258 		if (!serverpath)
259 			exit_stderr("not enough core");
260 		for (i = 0; i < serverargc; i++) {
261 			serverarg[i] = strdup(argv[i + NUMARG]);
262 			if (!serverarg[i])
263 				exit_stderr("not enough core");
264 		}
265 		serverarg[i] = NULL;
266 		/* fall throuth */
267 	case 1:	/* no local service */
268 		service = argv[NUMPRT];
269 		break;
270 	}
271 
272 	start_daemon();
273 
274 	/*
275 	 * Opening wild card socket for this service.
276 	 */
277 
278 	memset(&hints, 0, sizeof(hints));
279 	hints.ai_flags = AI_PASSIVE;
280 	hints.ai_family = family;
281 	hints.ai_socktype = SOCK_STREAM;
282 	hints.ai_protocol = IPPROTO_TCP;	/* SCTP? */
283 	error = getaddrinfo(NULL, service, &hints, &res);
284 	if (error)
285 		exit_failure("getaddrinfo: %s", gai_strerror(error));
286 
287 	s_wld = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
288 	if (s_wld == -1)
289 		exit_failure("socket: %s", strerror(errno));
290 
291 #ifdef IPV6_FAITH
292 	if (res->ai_family == AF_INET6) {
293 		error = setsockopt(s_wld, IPPROTO_IPV6, IPV6_FAITH, &on, sizeof(on));
294 		if (error == -1)
295 			exit_failure("setsockopt(IPV6_FAITH): %s",
296 			    strerror(errno));
297 	}
298 #endif
299 
300 	error = setsockopt(s_wld, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
301 	if (error == -1)
302 		exit_failure("setsockopt(SO_REUSEADDR): %s", strerror(errno));
303 
304 	error = setsockopt(s_wld, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
305 	if (error == -1)
306 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
307 
308 #ifdef IPV6_V6ONLY
309 	error = setsockopt(s_wld, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
310 	if (error == -1)
311 		exit_failure("setsockopt(IPV6_V6ONLY): %s", strerror(errno));
312 #endif
313 
314 	error = bind(s_wld, (struct sockaddr *)res->ai_addr, res->ai_addrlen);
315 	if (error == -1)
316 		exit_failure("bind: %s", strerror(errno));
317 
318 	error = listen(s_wld, 5);
319 	if (error == -1)
320 		exit_failure("listen: %s", strerror(errno));
321 
322 #ifdef USE_ROUTE
323 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
324 	if (sockfd < 0) {
325 		exit_failure("socket(PF_ROUTE): %s", strerror(errno));
326 		/*NOTREACHED*/
327 	}
328 #endif
329 
330 	/*
331 	 * Everything is OK.
332 	 */
333 
334 	snprintf(logname, sizeof(logname), "faithd %s", service);
335 	snprintf(procname, sizeof(procname), "accepting port %s", service);
336 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
337 	syslog(LOG_INFO, "Staring faith daemon for %s port", service);
338 
339 	play_service(s_wld);
340 	/* NOTREACHED */
341 	exit(1);	/*pacify gcc*/
342 }
343 
344 static void
345 play_service(int s_wld)
346 {
347 	struct sockaddr_storage srcaddr;
348 	socklen_t len;
349 	int s_src;
350 	pid_t child_pid;
351 	struct pollfd pfd[2];
352 	int error;
353 
354 	/*
355 	 * Wait, accept, fork, faith....
356 	 */
357 again:
358 	setproctitle("%s", procname);
359 
360 	pfd[0].fd = s_wld;
361 	pfd[0].events = POLLIN;
362 	pfd[1].fd = -1;
363 	pfd[1].revents = 0;
364 #ifdef USE_ROUTE
365 	if (sockfd) {
366 		pfd[1].fd = sockfd;
367 		pfd[1].events = POLLIN;
368 	}
369 #endif
370 
371 	error = poll(pfd, sizeof(pfd)/sizeof(pfd[0]), INFTIM);
372 	if (error < 0) {
373 		if (errno == EINTR)
374 			goto again;
375 		exit_failure("select: %s", strerror(errno));
376 		/*NOTREACHED*/
377 	}
378 
379 #ifdef USE_ROUTE
380 	if (pfd[1].revents & POLLIN)
381 	{
382 		update_myaddrs();
383 	}
384 #endif
385 	if (pfd[0].revents & POLLIN)
386 	{
387 		len = sizeof(srcaddr);
388 		s_src = accept(s_wld, (struct sockaddr *)&srcaddr, &len);
389 		if (s_src < 0) {
390 			if (errno == ECONNABORTED)
391 				goto again;
392 			exit_failure("socket: %s", strerror(errno));
393 			/*NOTREACHED*/
394 		}
395 		if (srcaddr.ss_family == AF_INET6 &&
396 		    IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&srcaddr)->sin6_addr)) {
397 			close(s_src);
398 			syslog(LOG_ERR, "connection from IPv4 mapped address?");
399 			goto again;
400 		}
401 
402 		child_pid = fork();
403 
404 		if (child_pid == 0) {
405 			/* child process */
406 			close(s_wld);
407 			closelog();
408 			openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
409 			play_child(s_src, (struct sockaddr *)&srcaddr);
410 			exit_failure("should never reach here");
411 			/*NOTREACHED*/
412 		} else {
413 			/* parent process */
414 			close(s_src);
415 			if (child_pid == -1)
416 				syslog(LOG_ERR, "can't fork");
417 		}
418 	}
419 	goto again;
420 }
421 
422 static void
423 play_child(int s_src, struct sockaddr *srcaddr)
424 {
425 	struct sockaddr_storage dstaddr6;
426 	struct sockaddr_storage dstaddr4;
427 	char src[NI_MAXHOST];
428 	char dst6[NI_MAXHOST];
429 	char dst4[NI_MAXHOST];
430 	socklen_t len = sizeof(dstaddr6);
431 	int s_dst, error, hport, nresvport, on = 1;
432 	struct timeval tv;
433 	struct sockaddr *sa4;
434 	const struct config *conf;
435 
436 	tv.tv_sec = 1;
437 	tv.tv_usec = 0;
438 
439 	getnameinfo(srcaddr, srcaddr->sa_len,
440 		src, sizeof(src), NULL, 0, NI_NUMERICHOST);
441 	syslog(LOG_INFO, "accepted a client from %s", src);
442 
443 	error = getsockname(s_src, (struct sockaddr *)&dstaddr6, &len);
444 	if (error == -1) {
445 		exit_failure("getsockname: %s", strerror(errno));
446 		/*NOTREACHED*/
447 	}
448 
449 	getnameinfo((struct sockaddr *)&dstaddr6, len,
450 		dst6, sizeof(dst6), NULL, 0, NI_NUMERICHOST);
451 	syslog(LOG_INFO, "the client is connecting to %s", dst6);
452 
453 	if (!faith_prefix((struct sockaddr *)&dstaddr6)) {
454 		if (serverpath) {
455 			/*
456 			 * Local service
457 			 */
458 			syslog(LOG_INFO, "executing local %s", serverpath);
459 			if (!inetd) {
460 				dup2(s_src, 0);
461 				close(s_src);
462 				dup2(0, 1);
463 				dup2(0, 2);
464 			}
465 			execv(serverpath, serverarg);
466 			syslog(LOG_ERR, "execv %s: %s", serverpath,
467 			    strerror(errno));
468 			_exit(EXIT_FAILURE);
469 		} else {
470 			close(s_src);
471 			exit_success("no local service for %s", service);
472 		}
473 	}
474 
475 	/*
476 	 * Act as a translator
477 	 */
478 
479 	switch (((struct sockaddr *)&dstaddr6)->sa_family) {
480 	case AF_INET6:
481 		if (!map6to4((struct sockaddr_in6 *)&dstaddr6,
482 		    (struct sockaddr_in *)&dstaddr4)) {
483 			close(s_src);
484 			exit_failure("map6to4 failed");
485 			/*NOTREACHED*/
486 		}
487 		syslog(LOG_INFO, "translating from v6 to v4");
488 		break;
489 	default:
490 		close(s_src);
491 		exit_failure("family not supported");
492 		/*NOTREACHED*/
493 	}
494 
495 	sa4 = (struct sockaddr *)&dstaddr4;
496 	getnameinfo(sa4, sa4->sa_len,
497 		dst4, sizeof(dst4), NULL, 0, NI_NUMERICHOST);
498 
499 	conf = config_match(srcaddr, sa4);
500 	if (!conf || !conf->permit) {
501 		close(s_src);
502 		if (conf) {
503 			exit_failure("translation to %s not permitted for %s",
504 			    dst4, prefix_string(&conf->match));
505 			/*NOTREACHED*/
506 		} else {
507 			exit_failure("translation to %s not permitted", dst4);
508 			/*NOTREACHED*/
509 		}
510 	}
511 
512 	syslog(LOG_INFO, "the translator is connecting to %s", dst4);
513 
514 	setproctitle("port %s, %s -> %s", service, src, dst4);
515 
516 	if (sa4->sa_family == AF_INET6)
517 		hport = ntohs(((struct sockaddr_in6 *)&dstaddr4)->sin6_port);
518 	else /* AF_INET */
519 		hport = ntohs(((struct sockaddr_in *)&dstaddr4)->sin_port);
520 
521 	if (pflag)
522 		s_dst = rresvport_af(&nresvport, sa4->sa_family);
523 	else
524 		s_dst = socket(sa4->sa_family, SOCK_STREAM, 0);
525 	if (s_dst < 0) {
526 		exit_failure("socket: %s", strerror(errno));
527 		/*NOTREACHED*/
528 	}
529 
530 	if (conf->src.a.ss_family) {
531 		if (bind(s_dst, (const struct sockaddr *)&conf->src.a,
532 		    conf->src.a.ss_len) < 0) {
533 			exit_failure("bind: %s", strerror(errno));
534 			/*NOTREACHED*/
535 		}
536 	}
537 
538 	error = setsockopt(s_dst, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
539 	if (error < 0) {
540 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
541 		/*NOTREACHED*/
542 	}
543 
544 	error = setsockopt(s_src, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
545 	if (error < 0) {
546 		exit_failure("setsockopt(SO_SNDTIMEO): %s", strerror(errno));
547 		/*NOTREACHED*/
548 	}
549 	error = setsockopt(s_dst, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
550 	if (error < 0) {
551 		exit_failure("setsockopt(SO_SNDTIMEO): %s", strerror(errno));
552 		/*NOTREACHED*/
553 	}
554 
555 	error = connect(s_dst, sa4, sa4->sa_len);
556 	if (error < 0) {
557 		exit_failure("connect: %s", strerror(errno));
558 		/*NOTREACHED*/
559 	}
560 
561 	switch (hport) {
562 	case FTP_PORT:
563 		ftp_relay(s_src, s_dst);
564 		break;
565 	default:
566 		tcp_relay(s_src, s_dst, service);
567 		break;
568 	}
569 
570 	/* NOTREACHED */
571 }
572 
573 /* 0: non faith, 1: faith */
574 static int
575 faith_prefix(struct sockaddr *dst)
576 {
577 #ifndef USE_ROUTE
578 	int mib[4], size;
579 	struct in6_addr faith_prefix;
580 	struct sockaddr_in6 *dst6 = (struct sockaddr_in *)dst;
581 
582 	if (dst->sa_family != AF_INET6)
583 		return 0;
584 
585 	mib[0] = CTL_NET;
586 	mib[1] = PF_INET6;
587 	mib[2] = IPPROTO_IPV6;
588 	mib[3] = IPV6CTL_FAITH_PREFIX;
589 	size = sizeof(struct in6_addr);
590 	if (sysctl(mib, 4, &faith_prefix, &size, NULL, 0) < 0) {
591 		exit_failure("sysctl: %s", strerror(errno));
592 		/*NOTREACHED*/
593 	}
594 
595 	if (memcmp(dst, &faith_prefix,
596 			sizeof(struct in6_addr) - sizeof(struct in_addr) == 0) {
597 		return 1;
598 	}
599 	return 0;
600 #else
601 	struct myaddrs *p;
602 	struct sockaddr_in6 *sin6;
603 	struct sockaddr_in *sin4;
604 	struct sockaddr_in6 *dst6;
605 	struct sockaddr_in *dst4;
606 	struct sockaddr_in dstmap;
607 
608 	dst6 = (struct sockaddr_in6 *)dst;
609 	if (dst->sa_family == AF_INET6
610 	 && IN6_IS_ADDR_V4MAPPED(&dst6->sin6_addr)) {
611 		/* ugly... */
612 		memset(&dstmap, 0, sizeof(dstmap));
613 		dstmap.sin_family = AF_INET;
614 		dstmap.sin_len = sizeof(dstmap);
615 		memcpy(&dstmap.sin_addr, &dst6->sin6_addr.s6_addr[12],
616 			sizeof(dstmap.sin_addr));
617 		dst = (struct sockaddr *)&dstmap;
618 	}
619 
620 	dst6 = (struct sockaddr_in6 *)dst;
621 	dst4 = (struct sockaddr_in *)dst;
622 
623 	for (p = myaddrs; p; p = p->next) {
624 		sin6 = (struct sockaddr_in6 *)p->addr;
625 		sin4 = (struct sockaddr_in *)p->addr;
626 
627 		if (p->addr->sa_len != dst->sa_len
628 		 || p->addr->sa_family != dst->sa_family)
629 			continue;
630 
631 		switch (dst->sa_family) {
632 		case AF_INET6:
633 			if (sin6->sin6_scope_id == dst6->sin6_scope_id
634 			 && IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &dst6->sin6_addr))
635 				return 0;
636 			break;
637 		case AF_INET:
638 			if (sin4->sin_addr.s_addr == dst4->sin_addr.s_addr)
639 				return 0;
640 			break;
641 		}
642 	}
643 	return 1;
644 #endif
645 }
646 
647 /* 0: non faith, 1: faith */
648 static int
649 map6to4(struct sockaddr_in6 *dst6, struct sockaddr_in *dst4)
650 {
651 	memset(dst4, 0, sizeof(*dst4));
652 	dst4->sin_len = sizeof(*dst4);
653 	dst4->sin_family = AF_INET;
654 	dst4->sin_port = dst6->sin6_port;
655 	memcpy(&dst4->sin_addr, &dst6->sin6_addr.s6_addr[12],
656 		sizeof(dst4->sin_addr));
657 
658 	if (dst4->sin_addr.s_addr == INADDR_ANY
659 	 || dst4->sin_addr.s_addr == INADDR_BROADCAST
660 	 || IN_MULTICAST(ntohl(dst4->sin_addr.s_addr)))
661 		return 0;
662 
663 	return 1;
664 }
665 
666 
667 static void
668 sig_child(int sig)
669 {
670 	int status;
671 	pid_t pid;
672 
673 	while ((pid = wait3(&status, WNOHANG, (struct rusage *)0)) > 0)
674 		if (WEXITSTATUS(status))
675 			syslog(LOG_WARNING, "child %ld exit status 0x%x",
676 			    (long)pid, status);
677 }
678 
679 void
680 sig_terminate(int sig)
681 {
682 	syslog(LOG_INFO, "Terminating faith daemon");
683 	exit(EXIT_SUCCESS);
684 }
685 
686 static void
687 start_daemon(void)
688 {
689 #ifdef SA_NOCLDWAIT
690 	struct sigaction sa;
691 #endif
692 
693 	if (daemon(0, 0) == -1)
694 		exit_stderr("daemon: %s", strerror(errno));
695 
696 #ifdef SA_NOCLDWAIT
697 	memset(&sa, 0, sizeof(sa));
698 	sa.sa_handler = sig_child;
699 	sa.sa_flags = SA_NOCLDWAIT;
700 	sigemptyset(&sa.sa_mask);
701 	sigaction(SIGCHLD, &sa, (struct sigaction *)0);
702 #else
703 	if (signal(SIGCHLD, sig_child) == SIG_ERR) {
704 		exit_failure("signal CHLD: %s", strerror(errno));
705 		/*NOTREACHED*/
706 	}
707 #endif
708 
709 	if (signal(SIGTERM, sig_terminate) == SIG_ERR) {
710 		exit_failure("signal TERM: %s", strerror(errno));
711 		/*NOTREACHED*/
712 	}
713 }
714 
715 static void
716 exit_stderr(const char *fmt, ...)
717 {
718 	va_list ap;
719 	char buf[BUFSIZ];
720 
721 	va_start(ap, fmt);
722 	vsnprintf(buf, sizeof(buf), fmt, ap);
723 	va_end(ap);
724 	fprintf(stderr, "%s\n", buf);
725 	exit(EXIT_FAILURE);
726 }
727 
728 void
729 exit_failure(const char *fmt, ...)
730 {
731 	va_list ap;
732 	char buf[BUFSIZ];
733 
734 	va_start(ap, fmt);
735 	vsnprintf(buf, sizeof(buf), fmt, ap);
736 	va_end(ap);
737 	syslog(LOG_ERR, "%s", buf);
738 	exit(EXIT_FAILURE);
739 }
740 
741 void
742 exit_success(const char *fmt, ...)
743 {
744 	va_list ap;
745 	char buf[BUFSIZ];
746 
747 	va_start(ap, fmt);
748 	vsnprintf(buf, sizeof(buf), fmt, ap);
749 	va_end(ap);
750 	syslog(LOG_INFO, "%s", buf);
751 	exit(EXIT_SUCCESS);
752 }
753 
754 #ifdef USE_ROUTE
755 static void
756 grab_myaddrs()
757 {
758 	struct ifaddrs *ifap, *ifa;
759 	struct myaddrs *p;
760 	struct sockaddr_in6 *sin6;
761 
762 	if (getifaddrs(&ifap) != 0) {
763 		exit_failure("getifaddrs");
764 		/*NOTREACHED*/
765 	}
766 
767 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
768 		switch (ifa->ifa_addr->sa_family) {
769 		case AF_INET:
770 		case AF_INET6:
771 			break;
772 		default:
773 			continue;
774 		}
775 
776 		p = (struct myaddrs *)malloc(sizeof(struct myaddrs) +
777 		    ifa->ifa_addr->sa_len);
778 		if (!p) {
779 			exit_failure("not enough core");
780 			/*NOTREACHED*/
781 		}
782 		memcpy(p + 1, ifa->ifa_addr, ifa->ifa_addr->sa_len);
783 		p->next = myaddrs;
784 		p->addr = (struct sockaddr *)(p + 1);
785 #ifdef __KAME__
786 		if (ifa->ifa_addr->sa_family == AF_INET6) {
787 			sin6 = (struct sockaddr_in6 *)p->addr;
788 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)
789 			 || IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) {
790 				sin6->sin6_scope_id =
791 					ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
792 				sin6->sin6_addr.s6_addr[2] = 0;
793 				sin6->sin6_addr.s6_addr[3] = 0;
794 			}
795 		}
796 #endif
797 		myaddrs = p;
798 		if (dflag) {
799 			char hbuf[NI_MAXHOST];
800 			getnameinfo(p->addr, p->addr->sa_len,
801 				hbuf, sizeof(hbuf), NULL, 0,
802 				NI_NUMERICHOST);
803 			syslog(LOG_INFO, "my interface: %s %s", hbuf,
804 			    ifa->ifa_name);
805 		}
806 	}
807 
808 	freeifaddrs(ifap);
809 }
810 
811 static void
812 free_myaddrs()
813 {
814 	struct myaddrs *p, *q;
815 
816 	p = myaddrs;
817 	while (p) {
818 		q = p->next;
819 		free(p);
820 		p = q;
821 	}
822 	myaddrs = NULL;
823 }
824 
825 static void
826 update_myaddrs()
827 {
828 	char msg[BUFSIZ];
829 	int len;
830 	struct rt_msghdr *rtm;
831 
832 	len = read(sockfd, msg, sizeof(msg));
833 	if (len < 0) {
834 		syslog(LOG_ERR, "read(PF_ROUTE) failed");
835 		return;
836 	}
837 	rtm = (struct rt_msghdr *)msg;
838 	if (len < 4 || len < rtm->rtm_msglen) {
839 		syslog(LOG_ERR, "read(PF_ROUTE) short read");
840 		return;
841 	}
842 	if (rtm->rtm_version != RTM_VERSION) {
843 		syslog(LOG_ERR, "routing socket version mismatch");
844 		close(sockfd);
845 		sockfd = 0;
846 		return;
847 	}
848 	switch (rtm->rtm_type) {
849 	case RTM_NEWADDR:
850 	case RTM_DELADDR:
851 	case RTM_IFINFO:
852 		break;
853 	default:
854 		return;
855 	}
856 	/* XXX more filters here? */
857 
858 	syslog(LOG_INFO, "update interface address list");
859 	free_myaddrs();
860 	grab_myaddrs();
861 }
862 #endif /*USE_ROUTE*/
863 
864 static void
865 usage()
866 {
867 	fprintf(stderr, "usage: %s [-dp] [-f conf] service [serverpath [serverargs]]\n",
868 		faithdname);
869 	exit(0);
870 }
871