xref: /netbsd/usr.sbin/faithd/faithd.c (revision bf9ec67e)
1 /*	$NetBSD: faithd.c,v 1.25 2002/05/09 14:24:03 itojun Exp $	*/
2 /*	$KAME: faithd.c,v 1.50 2002/05/09 14:06:52 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/param.h>
41 #include <sys/types.h>
42 #include <sys/sysctl.h>
43 #include <sys/socket.h>
44 #include <sys/wait.h>
45 #include <sys/stat.h>
46 #include <sys/time.h>
47 #include <sys/ioctl.h>
48 #ifdef __FreeBSD__
49 #include <libutil.h>
50 #endif
51 
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <stdarg.h>
55 #include <string.h>
56 #include <syslog.h>
57 #include <unistd.h>
58 #include <errno.h>
59 #include <signal.h>
60 #include <fcntl.h>
61 #include <termios.h>
62 
63 #include <net/if_types.h>
64 #ifdef IFT_FAITH
65 # define USE_ROUTE
66 # include <net/if.h>
67 # include <net/route.h>
68 # include <net/if_dl.h>
69 #endif
70 
71 #include <netinet/in.h>
72 #include <arpa/inet.h>
73 #include <netdb.h>
74 #include <ifaddrs.h>
75 
76 #ifdef FAITH4
77 #include <resolv.h>
78 #include <arpa/nameser.h>
79 #ifndef FAITH_NS
80 #define FAITH_NS "FAITH_NS"
81 #endif
82 #endif
83 
84 #include "faithd.h"
85 #include "prefix.h"
86 
87 char *serverpath = NULL;
88 char *serverarg[MAXARGV + 1];
89 static char *faithdname = NULL;
90 char logname[BUFSIZ];
91 char procname[BUFSIZ];
92 struct myaddrs {
93 	struct myaddrs *next;
94 	struct sockaddr *addr;
95 };
96 struct myaddrs *myaddrs = NULL;
97 static const char *service;
98 #ifdef USE_ROUTE
99 static int sockfd = 0;
100 #endif
101 int dflag = 0;
102 static int pflag = 0;
103 static int inetd = 0;
104 static char *configfile = NULL;
105 
106 int main __P((int, char **));
107 static int inetd_main __P((int, char **));
108 static int daemon_main __P((int, char **));
109 static void play_service __P((int));
110 static void play_child __P((int, struct sockaddr *));
111 static int faith_prefix __P((struct sockaddr *));
112 static int map6to4 __P((struct sockaddr_in6 *, struct sockaddr_in *));
113 #ifdef FAITH4
114 static int map4to6 __P((struct sockaddr_in *, struct sockaddr_in6 *));
115 #endif
116 static void sig_child __P((int));
117 static void sig_terminate __P((int));
118 static void start_daemon __P((void));
119 static void exit_stderr __P((const char *, ...))
120 	__attribute__((__format__(__printf__, 1, 2)));
121 static void grab_myaddrs __P((void));
122 static void free_myaddrs __P((void));
123 static void update_myaddrs __P((void));
124 static void usage __P((void));
125 
126 int
127 main(int argc, char **argv)
128 {
129 
130 	/*
131 	 * Initializing stuff
132 	 */
133 
134 	faithdname = strrchr(argv[0], '/');
135 	if (faithdname)
136 		faithdname++;
137 	else
138 		faithdname = argv[0];
139 
140 	if (strcmp(faithdname, "faithd") != 0) {
141 		inetd = 1;
142 		return inetd_main(argc, argv);
143 	} else
144 		return daemon_main(argc, argv);
145 }
146 
147 static int
148 inetd_main(int argc, char **argv)
149 {
150 	char path[MAXPATHLEN];
151 	struct sockaddr_storage me;
152 	struct sockaddr_storage from;
153 	int melen, fromlen;
154 	int i;
155 	int error;
156 	const int on = 1;
157 	char sbuf[NI_MAXSERV], snum[NI_MAXSERV];
158 
159 	if (config_load(configfile) < 0 && configfile) {
160 		exit_failure("could not load config file");
161 		/*NOTREACHED*/
162 	}
163 
164 	if (strrchr(argv[0], '/') == NULL)
165 		snprintf(path, sizeof(path), "%s/%s", DEFAULT_DIR, argv[0]);
166 	else
167 		snprintf(path, sizeof(path), "%s", argv[0]);
168 
169 #ifdef USE_ROUTE
170 	grab_myaddrs();
171 
172 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
173 	if (sockfd < 0) {
174 		exit_failure("socket(PF_ROUTE): %s", strerror(errno));
175 		/*NOTREACHED*/
176 	}
177 #endif
178 
179 	melen = sizeof(me);
180 	if (getsockname(STDIN_FILENO, (struct sockaddr *)&me, &melen) < 0) {
181 		exit_failure("getsockname: %s", strerror(errno));
182 		/*NOTREACHED*/
183 	}
184 	fromlen = sizeof(from);
185 	if (getpeername(STDIN_FILENO, (struct sockaddr *)&from, &fromlen) < 0) {
186 		exit_failure("getpeername: %s", strerror(errno));
187 		/*NOTREACHED*/
188 	}
189 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
190 	    sbuf, sizeof(sbuf), NI_NUMERICHOST) == 0)
191 		service = sbuf;
192 	else
193 		service = DEFAULT_PORT_NAME;
194 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
195 	    snum, sizeof(snum), NI_NUMERICHOST) != 0)
196 		snprintf(snum, sizeof(snum), "?");
197 
198 	snprintf(logname, sizeof(logname), "faithd %s", snum);
199 	snprintf(procname, sizeof(procname), "accepting port %s", snum);
200 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
201 
202 	if (argc >= MAXARGV) {
203 		exit_failure("too many arguments");
204 		/*NOTREACHED*/
205 	}
206 	serverarg[0] = serverpath = path;
207 	for (i = 1; i < argc; i++)
208 		serverarg[i] = argv[i];
209 	serverarg[i] = NULL;
210 
211 	error = setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &on,
212 	    sizeof(on));
213 	if (error < 0) {
214 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
215 		/*NOTREACHED*/
216 	}
217 
218 	play_child(STDIN_FILENO, (struct sockaddr *)&from);
219 	exit_failure("should not reach here");
220 	return 0;	/*dummy!*/
221 }
222 
223 static int
224 daemon_main(int argc, char **argv)
225 {
226 	struct addrinfo hints, *res;
227 	int s_wld, error, i, serverargc, on = 1;
228 	int family = AF_INET6;
229 	int c;
230 #ifdef FAITH_NS
231 	char *ns;
232 #endif /* FAITH_NS */
233 
234 	while ((c = getopt(argc, argv, "df:p46")) != -1) {
235 		switch (c) {
236 		case 'd':
237 			dflag++;
238 			break;
239 		case 'f':
240 			configfile = optarg;
241 			break;
242 		case 'p':
243 			pflag++;
244 			break;
245 #ifdef FAITH4
246 		case '4':
247 			family = AF_INET;
248 			break;
249 		case '6':
250 			family = AF_INET6;
251 			break;
252 #endif
253 		default:
254 			usage();
255 			/*NOTREACHED*/
256 		}
257 	}
258 	argc -= optind;
259 	argv += optind;
260 
261 	if (config_load(configfile) < 0 && configfile) {
262 		exit_failure("could not load config file");
263 		/*NOTREACHED*/
264 	}
265 
266 #ifdef FAITH_NS
267 	if ((ns = getenv(FAITH_NS)) != NULL) {
268 		struct sockaddr_storage ss;
269 		struct addrinfo hints, *res;
270 		char serv[NI_MAXSERV];
271 
272 		memset(&ss, 0, sizeof(ss));
273 		memset(&hints, 0, sizeof(hints));
274 		snprintf(serv, sizeof(serv), "%u", NAMESERVER_PORT);
275 		hints.ai_flags = AI_NUMERICHOST;
276 		if (getaddrinfo(ns, serv, &hints, &res) ==  0) {
277 			res_init();
278 			memcpy(&_res_ext.nsaddr, res->ai_addr, res->ai_addrlen);
279 			_res.nscount = 1;
280 		}
281 	}
282 #endif /* FAITH_NS */
283 
284 #ifdef USE_ROUTE
285 	grab_myaddrs();
286 #endif
287 
288 	switch (argc) {
289 	case 0:
290 		usage();
291 		/*NOTREACHED*/
292 	default:
293 		serverargc = argc - NUMARG;
294 		if (serverargc >= MAXARGV)
295 			exit_stderr("too many arguments");
296 
297 		serverpath = malloc(strlen(argv[NUMPRG]) + 1);
298 		if (!serverpath)
299 			exit_stderr("not enough core");
300 		strcpy(serverpath, argv[NUMPRG]);
301 		for (i = 0; i < serverargc; i++) {
302 			serverarg[i] = malloc(strlen(argv[i + NUMARG]) + 1);
303 			if (!serverarg[i])
304 				exit_stderr("not enough core");
305 			strcpy(serverarg[i], argv[i + NUMARG]);
306 		}
307 		serverarg[i] = NULL;
308 		/* fall throuth */
309 	case 1:	/* no local service */
310 		service = argv[NUMPRT];
311 		break;
312 	}
313 
314 	start_daemon();
315 
316 	/*
317 	 * Opening wild card socket for this service.
318 	 */
319 
320 	memset(&hints, 0, sizeof(hints));
321 	hints.ai_flags = AI_PASSIVE;
322 	hints.ai_family = family;
323 	hints.ai_socktype = SOCK_STREAM;
324 	hints.ai_protocol = 0;
325 	error = getaddrinfo(NULL, service, &hints, &res);
326 	if (error)
327 		exit_failure("getaddrinfo: %s", gai_strerror(error));
328 
329 	s_wld = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
330 	if (s_wld == -1)
331 		exit_failure("socket: %s", strerror(errno));
332 
333 #ifdef IPV6_FAITH
334 	if (res->ai_family == AF_INET6) {
335 		error = setsockopt(s_wld, IPPROTO_IPV6, IPV6_FAITH, &on, sizeof(on));
336 		if (error == -1)
337 			exit_failure("setsockopt(IPV6_FAITH): %s",
338 			    strerror(errno));
339 	}
340 #endif
341 #ifdef FAITH4
342 #ifdef IP_FAITH
343 	if (res->ai_family == AF_INET) {
344 		error = setsockopt(s_wld, IPPROTO_IP, IP_FAITH, &on, sizeof(on));
345 		if (error == -1)
346 			exit_failure("setsockopt(IP_FAITH): %s",
347 			    strerror(errno));
348 	}
349 #endif
350 #endif /* FAITH4 */
351 
352 	error = setsockopt(s_wld, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
353 	if (error == -1)
354 		exit_failure("setsockopt(SO_REUSEADDR): %s", strerror(errno));
355 
356 	error = setsockopt(s_wld, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
357 	if (error == -1)
358 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
359 
360 	error = bind(s_wld, (struct sockaddr *)res->ai_addr, res->ai_addrlen);
361 	if (error == -1)
362 		exit_failure("bind: %s", strerror(errno));
363 
364 	error = listen(s_wld, 5);
365 	if (error == -1)
366 		exit_failure("listen: %s", strerror(errno));
367 
368 #ifdef USE_ROUTE
369 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
370 	if (sockfd < 0) {
371 		exit_failure("socket(PF_ROUTE): %s", strerror(errno));
372 		/*NOTREACHED*/
373 	}
374 #endif
375 
376 	/*
377 	 * Everything is OK.
378 	 */
379 
380 	snprintf(logname, sizeof(logname), "faithd %s", service);
381 	snprintf(procname, sizeof(procname), "accepting port %s", service);
382 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
383 	syslog(LOG_INFO, "Staring faith daemon for %s port", service);
384 
385 	play_service(s_wld);
386 	/* NOTREACHED */
387 	exit(1);	/*pacify gcc*/
388 }
389 
390 static void
391 play_service(int s_wld)
392 {
393 	struct sockaddr_storage srcaddr;
394 	int len;
395 	int s_src;
396 	pid_t child_pid;
397 	fd_set rfds;
398 	int error;
399 	int maxfd;
400 
401 	/*
402 	 * Wait, accept, fork, faith....
403 	 */
404 again:
405 	setproctitle("%s", procname);
406 
407 	FD_ZERO(&rfds);
408 	FD_SET(s_wld, &rfds);
409 	maxfd = s_wld;
410 #ifdef USE_ROUTE
411 	if (sockfd) {
412 		FD_SET(sockfd, &rfds);
413 		maxfd = (maxfd < sockfd) ? sockfd : maxfd;
414 	}
415 #endif
416 
417 	error = select(maxfd + 1, &rfds, NULL, NULL, NULL);
418 	if (error < 0) {
419 		if (errno == EINTR)
420 			goto again;
421 		exit_failure("select: %s", strerror(errno));
422 		/*NOTREACHED*/
423 	}
424 
425 #ifdef USE_ROUTE
426 	if (FD_ISSET(sockfd, &rfds)) {
427 		update_myaddrs();
428 	}
429 #endif
430 	if (FD_ISSET(s_wld, &rfds)) {
431 		len = sizeof(srcaddr);
432 		s_src = accept(s_wld, (struct sockaddr *)&srcaddr,
433 			&len);
434 		if (s_src < 0) {
435 			if (errno == ECONNABORTED)
436 				goto again;
437 			exit_failure("socket: %s", strerror(errno));
438 			/*NOTREACHED*/
439 		}
440 
441 		child_pid = fork();
442 
443 		if (child_pid == 0) {
444 			/* child process */
445 			close(s_wld);
446 			closelog();
447 			openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
448 			play_child(s_src, (struct sockaddr *)&srcaddr);
449 			exit_failure("should never reach here");
450 			/*NOTREACHED*/
451 		} else {
452 			/* parent process */
453 			close(s_src);
454 			if (child_pid == -1)
455 				syslog(LOG_ERR, "can't fork");
456 		}
457 	}
458 	goto again;
459 }
460 
461 static void
462 play_child(int s_src, struct sockaddr *srcaddr)
463 {
464 	struct sockaddr_storage dstaddr6;
465 	struct sockaddr_storage dstaddr4;
466 	char src[NI_MAXHOST];
467 	char dst6[NI_MAXHOST];
468 	char dst4[NI_MAXHOST];
469 	int len = sizeof(dstaddr6);
470 	int s_dst, error, hport, nresvport, on = 1;
471 	struct timeval tv;
472 	struct sockaddr *sa4;
473 	const struct config *conf;
474 
475 	tv.tv_sec = 1;
476 	tv.tv_usec = 0;
477 
478 	getnameinfo(srcaddr, srcaddr->sa_len,
479 		src, sizeof(src), NULL, 0, NI_NUMERICHOST);
480 	syslog(LOG_INFO, "accepted a client from %s", src);
481 
482 	error = getsockname(s_src, (struct sockaddr *)&dstaddr6, &len);
483 	if (error == -1) {
484 		exit_failure("getsockname: %s", strerror(errno));
485 		/*NOTREACHED*/
486 	}
487 
488 	getnameinfo((struct sockaddr *)&dstaddr6, len,
489 		dst6, sizeof(dst6), NULL, 0, NI_NUMERICHOST);
490 	syslog(LOG_INFO, "the client is connecting to %s", dst6);
491 
492 	if (!faith_prefix((struct sockaddr *)&dstaddr6)) {
493 		if (serverpath) {
494 			/*
495 			 * Local service
496 			 */
497 			syslog(LOG_INFO, "executing local %s", serverpath);
498 			if (!inetd) {
499 				dup2(s_src, 0);
500 				close(s_src);
501 				dup2(0, 1);
502 				dup2(0, 2);
503 			}
504 			execv(serverpath, serverarg);
505 			syslog(LOG_ERR, "execv %s: %s", serverpath,
506 			    strerror(errno));
507 			_exit(EXIT_FAILURE);
508 		} else {
509 			close(s_src);
510 			exit_success("no local service for %s", service);
511 		}
512 	}
513 
514 	/*
515 	 * Act as a translator
516 	 */
517 
518 	switch (((struct sockaddr *)&dstaddr6)->sa_family) {
519 	case AF_INET6:
520 		if (!map6to4((struct sockaddr_in6 *)&dstaddr6,
521 		    (struct sockaddr_in *)&dstaddr4)) {
522 			close(s_src);
523 			exit_failure("map6to4 failed");
524 			/*NOTREACHED*/
525 		}
526 		syslog(LOG_INFO, "translating from v6 to v4");
527 		break;
528 #ifdef FAITH4
529 	case AF_INET:
530 		if (!map4to6((struct sockaddr_in *)&dstaddr6,
531 		    (struct sockaddr_in6 *)&dstaddr4)) {
532 			close(s_src);
533 			exit_failure("map4to6 failed");
534 			/*NOTREACHED*/
535 		}
536 		syslog(LOG_INFO, "translating from v4 to v6");
537 		break;
538 #endif
539 	default:
540 		close(s_src);
541 		exit_failure("family not supported");
542 		/*NOTREACHED*/
543 	}
544 
545 	sa4 = (struct sockaddr *)&dstaddr4;
546 	getnameinfo(sa4, sa4->sa_len,
547 		dst4, sizeof(dst4), NULL, 0, NI_NUMERICHOST);
548 
549 	conf = config_match(srcaddr, sa4);
550 	if (!conf || !conf->permit) {
551 		close(s_src);
552 		if (conf) {
553 			exit_failure("translation to %s not permitted for %s",
554 			    dst4, prefix_string(&conf->match));
555 			/*NOTREACHED*/
556 		} else {
557 			exit_failure("translation to %s not permitted", dst4);
558 			/*NOTREACHED*/
559 		}
560 	}
561 
562 	syslog(LOG_INFO, "the translator is connecting to %s", dst4);
563 
564 	setproctitle("port %s, %s -> %s", service, src, dst4);
565 
566 	if (sa4->sa_family == AF_INET6)
567 		hport = ntohs(((struct sockaddr_in6 *)&dstaddr4)->sin6_port);
568 	else /* AF_INET */
569 		hport = ntohs(((struct sockaddr_in *)&dstaddr4)->sin_port);
570 
571 	if (pflag)
572 		s_dst = rresvport_af(&nresvport, sa4->sa_family);
573 	else
574 		s_dst = socket(sa4->sa_family, SOCK_STREAM, 0);
575 	if (s_dst < 0) {
576 		exit_failure("socket: %s", strerror(errno));
577 		/*NOTREACHED*/
578 	}
579 
580 	if (conf->src.a.ss_family) {
581 		if (bind(s_dst, (const struct sockaddr *)&conf->src.a,
582 		    conf->src.a.ss_len) < 0) {
583 			exit_failure("bind: %s", strerror(errno));
584 			/*NOTREACHED*/
585 		}
586 	}
587 
588 	error = setsockopt(s_dst, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
589 	if (error < 0) {
590 		exit_failure("setsockopt(SO_OOBINLINE): %s", strerror(errno));
591 		/*NOTREACHED*/
592 	}
593 
594 	error = setsockopt(s_src, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
595 	if (error < 0) {
596 		exit_failure("setsockopt(SO_SNDTIMEO): %s", strerror(errno));
597 		/*NOTREACHED*/
598 	}
599 	error = setsockopt(s_dst, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
600 	if (error < 0) {
601 		exit_failure("setsockopt(SO_SNDTIMEO): %s", strerror(errno));
602 		/*NOTREACHED*/
603 	}
604 
605 	error = connect(s_dst, sa4, sa4->sa_len);
606 	if (error < 0) {
607 		exit_failure("connect: %s", strerror(errno));
608 		/*NOTREACHED*/
609 	}
610 
611 	switch (hport) {
612 	case FTP_PORT:
613 		ftp_relay(s_src, s_dst);
614 		break;
615 	default:
616 		tcp_relay(s_src, s_dst, service);
617 		break;
618 	}
619 
620 	/* NOTREACHED */
621 }
622 
623 /* 0: non faith, 1: faith */
624 static int
625 faith_prefix(struct sockaddr *dst)
626 {
627 #ifndef USE_ROUTE
628 	int mib[4], size;
629 	struct in6_addr faith_prefix;
630 	struct sockaddr_in6 *dst6 = (struct sockaddr_in *)dst;
631 
632 	if (dst->sa_family != AF_INET6)
633 		return 0;
634 
635 	mib[0] = CTL_NET;
636 	mib[1] = PF_INET6;
637 	mib[2] = IPPROTO_IPV6;
638 	mib[3] = IPV6CTL_FAITH_PREFIX;
639 	size = sizeof(struct in6_addr);
640 	if (sysctl(mib, 4, &faith_prefix, &size, NULL, 0) < 0) {
641 		exit_failure("sysctl: %s", strerror(errno));
642 		/*NOTREACHED*/
643 	}
644 
645 	if (memcmp(dst, &faith_prefix,
646 			sizeof(struct in6_addr) - sizeof(struct in_addr) == 0) {
647 		return 1;
648 	}
649 	return 0;
650 #else
651 	struct myaddrs *p;
652 	struct sockaddr_in6 *sin6;
653 	struct sockaddr_in *sin4;
654 	struct sockaddr_in6 *dst6;
655 	struct sockaddr_in *dst4;
656 	struct sockaddr_in dstmap;
657 
658 	dst6 = (struct sockaddr_in6 *)dst;
659 	if (dst->sa_family == AF_INET6
660 	 && IN6_IS_ADDR_V4MAPPED(&dst6->sin6_addr)) {
661 		/* ugly... */
662 		memset(&dstmap, 0, sizeof(dstmap));
663 		dstmap.sin_family = AF_INET;
664 		dstmap.sin_len = sizeof(dstmap);
665 		memcpy(&dstmap.sin_addr, &dst6->sin6_addr.s6_addr[12],
666 			sizeof(dstmap.sin_addr));
667 		dst = (struct sockaddr *)&dstmap;
668 	}
669 
670 	dst6 = (struct sockaddr_in6 *)dst;
671 	dst4 = (struct sockaddr_in *)dst;
672 
673 	for (p = myaddrs; p; p = p->next) {
674 		sin6 = (struct sockaddr_in6 *)p->addr;
675 		sin4 = (struct sockaddr_in *)p->addr;
676 
677 		if (p->addr->sa_len != dst->sa_len
678 		 || p->addr->sa_family != dst->sa_family)
679 			continue;
680 
681 		switch (dst->sa_family) {
682 		case AF_INET6:
683 			if (sin6->sin6_scope_id == dst6->sin6_scope_id
684 			 && IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &dst6->sin6_addr))
685 				return 0;
686 			break;
687 		case AF_INET:
688 			if (sin4->sin_addr.s_addr == dst4->sin_addr.s_addr)
689 				return 0;
690 			break;
691 		}
692 	}
693 	return 1;
694 #endif
695 }
696 
697 /* 0: non faith, 1: faith */
698 static int
699 map6to4(struct sockaddr_in6 *dst6, struct sockaddr_in *dst4)
700 {
701 	memset(dst4, 0, sizeof(*dst4));
702 	dst4->sin_len = sizeof(*dst4);
703 	dst4->sin_family = AF_INET;
704 	dst4->sin_port = dst6->sin6_port;
705 	memcpy(&dst4->sin_addr, &dst6->sin6_addr.s6_addr[12],
706 		sizeof(dst4->sin_addr));
707 
708 	if (dst4->sin_addr.s_addr == INADDR_ANY
709 	 || dst4->sin_addr.s_addr == INADDR_BROADCAST
710 	 || IN_MULTICAST(ntohl(dst4->sin_addr.s_addr)))
711 		return 0;
712 
713 	return 1;
714 }
715 
716 #ifdef FAITH4
717 /* 0: non faith, 1: faith */
718 static int
719 map4to6(struct sockaddr_in *dst4, struct sockaddr_in6 *dst6)
720 {
721 	char host[NI_MAXHOST];
722 	char serv[NI_MAXSERV];
723 	struct addrinfo hints, *res;
724 	int ai_errno;
725 
726 	if (getnameinfo((struct sockaddr *)dst4, dst4->sin_len, host, sizeof(host),
727 			serv, sizeof(serv), NI_NAMEREQD|NI_NUMERICSERV) != 0)
728 		return 0;
729 
730 	memset(&hints, 0, sizeof(hints));
731 	hints.ai_flags = 0;
732 	hints.ai_family = AF_INET6;
733 	hints.ai_socktype = SOCK_STREAM;
734 	hints.ai_protocol = 0;
735 
736 	if ((ai_errno = getaddrinfo(host, serv, &hints, &res)) != 0) {
737 		syslog(LOG_INFO, "%s %s: %s", host, serv,
738 		    gai_strerror(ai_errno));
739 		return 0;
740 	}
741 
742 	memcpy(dst6, res->ai_addr, res->ai_addrlen);
743 
744 	freeaddrinfo(res);
745 
746 	return 1;
747 }
748 #endif /* FAITH4 */
749 
750 static void
751 sig_child(int sig)
752 {
753 	int status;
754 	pid_t pid;
755 
756 	while ((pid = wait3(&status, WNOHANG, (struct rusage *)0)) > 0)
757 		if (WEXITSTATUS(status))
758 			syslog(LOG_WARNING, "child %d exit status 0x%x",
759 			    pid, status);
760 }
761 
762 void
763 sig_terminate(int sig)
764 {
765 	syslog(LOG_INFO, "Terminating faith daemon");
766 	exit(EXIT_SUCCESS);
767 }
768 
769 static void
770 start_daemon(void)
771 {
772 #ifdef SA_NOCLDWAIT
773 	struct sigaction sa;
774 #endif
775 
776 	if (daemon(0, 0) == -1)
777 		exit_stderr("daemon: %s", strerror(errno));
778 
779 #ifdef SA_NOCLDWAIT
780 	memset(&sa, 0, sizeof(sa));
781 	sa.sa_handler = sig_child;
782 	sa.sa_flags = SA_NOCLDWAIT;
783 	sigemptyset(&sa.sa_mask);
784 	sigaction(SIGCHLD, &sa, (struct sigaction *)0);
785 #else
786 	if (signal(SIGCHLD, sig_child) == SIG_ERR) {
787 		exit_failure("signal CHLD: %s", strerror(errno));
788 		/*NOTREACHED*/
789 	}
790 #endif
791 
792 	if (signal(SIGTERM, sig_terminate) == SIG_ERR) {
793 		exit_failure("signal TERM: %s", strerror(errno));
794 		/*NOTREACHED*/
795 	}
796 }
797 
798 static void
799 exit_stderr(const char *fmt, ...)
800 {
801 	va_list ap;
802 	char buf[BUFSIZ];
803 
804 	va_start(ap, fmt);
805 	vsnprintf(buf, sizeof(buf), fmt, ap);
806 	va_end(ap);
807 	fprintf(stderr, "%s\n", buf);
808 	exit(EXIT_FAILURE);
809 }
810 
811 void
812 exit_failure(const char *fmt, ...)
813 {
814 	va_list ap;
815 	char buf[BUFSIZ];
816 
817 	va_start(ap, fmt);
818 	vsnprintf(buf, sizeof(buf), fmt, ap);
819 	va_end(ap);
820 	syslog(LOG_ERR, "%s", buf);
821 	exit(EXIT_FAILURE);
822 }
823 
824 void
825 exit_success(const char *fmt, ...)
826 {
827 	va_list ap;
828 	char buf[BUFSIZ];
829 
830 	va_start(ap, fmt);
831 	vsnprintf(buf, sizeof(buf), fmt, ap);
832 	va_end(ap);
833 	syslog(LOG_INFO, "%s", buf);
834 	exit(EXIT_SUCCESS);
835 }
836 
837 #ifdef USE_ROUTE
838 static void
839 grab_myaddrs()
840 {
841 	struct ifaddrs *ifap, *ifa;
842 	struct myaddrs *p;
843 	struct sockaddr_in6 *sin6;
844 
845 	if (getifaddrs(&ifap) != 0) {
846 		exit_failure("getifaddrs");
847 		/*NOTREACHED*/
848 	}
849 
850 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
851 		switch (ifa->ifa_addr->sa_family) {
852 		case AF_INET:
853 		case AF_INET6:
854 			break;
855 		default:
856 			continue;
857 		}
858 
859 		p = (struct myaddrs *)malloc(sizeof(struct myaddrs) +
860 		    ifa->ifa_addr->sa_len);
861 		if (!p) {
862 			exit_failure("not enough core");
863 			/*NOTREACHED*/
864 		}
865 		memcpy(p + 1, ifa->ifa_addr, ifa->ifa_addr->sa_len);
866 		p->next = myaddrs;
867 		p->addr = (struct sockaddr *)(p + 1);
868 #ifdef __KAME__
869 		if (ifa->ifa_addr->sa_family == AF_INET6) {
870 			sin6 = (struct sockaddr_in6 *)p->addr;
871 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)
872 			 || IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) {
873 				sin6->sin6_scope_id =
874 					ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
875 				sin6->sin6_addr.s6_addr[2] = 0;
876 				sin6->sin6_addr.s6_addr[3] = 0;
877 			}
878 		}
879 #endif
880 		myaddrs = p;
881 		if (dflag) {
882 			char hbuf[NI_MAXHOST];
883 			getnameinfo(p->addr, p->addr->sa_len,
884 				hbuf, sizeof(hbuf), NULL, 0,
885 				NI_NUMERICHOST);
886 			syslog(LOG_INFO, "my interface: %s %s", hbuf,
887 			    ifa->ifa_name);
888 		}
889 	}
890 
891 	freeifaddrs(ifap);
892 }
893 
894 static void
895 free_myaddrs()
896 {
897 	struct myaddrs *p, *q;
898 
899 	p = myaddrs;
900 	while (p) {
901 		q = p->next;
902 		free(p);
903 		p = q;
904 	}
905 	myaddrs = NULL;
906 }
907 
908 static void
909 update_myaddrs()
910 {
911 	char msg[BUFSIZ];
912 	int len;
913 	struct rt_msghdr *rtm;
914 
915 	len = read(sockfd, msg, sizeof(msg));
916 	if (len < 0) {
917 		syslog(LOG_ERR, "read(PF_ROUTE) failed");
918 		return;
919 	}
920 	rtm = (struct rt_msghdr *)msg;
921 	if (len < 4 || len < rtm->rtm_msglen) {
922 		syslog(LOG_ERR, "read(PF_ROUTE) short read");
923 		return;
924 	}
925 	if (rtm->rtm_version != RTM_VERSION) {
926 		syslog(LOG_ERR, "routing socket version mismatch");
927 		close(sockfd);
928 		sockfd = 0;
929 		return;
930 	}
931 	switch (rtm->rtm_type) {
932 	case RTM_NEWADDR:
933 	case RTM_DELADDR:
934 	case RTM_IFINFO:
935 		break;
936 	default:
937 		return;
938 	}
939 	/* XXX more filters here? */
940 
941 	syslog(LOG_INFO, "update interface address list");
942 	free_myaddrs();
943 	grab_myaddrs();
944 }
945 #endif /*USE_ROUTE*/
946 
947 static void
948 usage()
949 {
950 	fprintf(stderr, "usage: %s [-dp] [-f conf] service [serverpath [serverargs]]\n",
951 		faithdname);
952 	exit(0);
953 }
954