xref: /netbsd-src/usr.sbin/faithd/faithd.c (revision bcc8ec9959e7b01e313d813067bfb43a3ad70551)
1 /*	$NetBSD: faithd.c,v 1.16 2001/01/11 03:34:12 lukem Exp $	*/
2 /*	$KAME: faithd.c,v 1.31 2000/10/05 22:20:37 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 #define HAVE_GETIFADDRS
40 
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 #ifdef __FreeBSD__
50 #include <libutil.h>
51 #endif
52 
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <stdarg.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <unistd.h>
59 #include <errno.h>
60 #include <signal.h>
61 #include <fcntl.h>
62 #include <termios.h>
63 
64 #include <net/if_types.h>
65 #ifdef IFT_FAITH
66 # define USE_ROUTE
67 # include <net/if.h>
68 # include <net/route.h>
69 # include <net/if_dl.h>
70 #endif
71 
72 #include <netinet/in.h>
73 #include <arpa/inet.h>
74 #include <netdb.h>
75 #ifdef HAVE_GETIFADDRS
76 #include <ifaddrs.h>
77 #endif
78 
79 #ifdef FAITH4
80 #include <resolv.h>
81 #include <arpa/nameser.h>
82 #ifndef FAITH_NS
83 #define FAITH_NS "FAITH_NS"
84 #endif
85 #endif
86 
87 #include "faithd.h"
88 
89 char *serverpath = NULL;
90 char *serverarg[MAXARGV + 1];
91 static char *faithdname = NULL;
92 char logname[BUFSIZ];
93 char procname[BUFSIZ];
94 struct myaddrs {
95 	struct myaddrs *next;
96 	struct sockaddr *addr;
97 };
98 struct myaddrs *myaddrs = NULL;
99 static char *service;
100 #ifdef USE_ROUTE
101 static int sockfd = 0;
102 #endif
103 int dflag = 0;
104 static int pflag = 0;
105 static int inetd = 0;
106 
107 int main __P((int, char **));
108 static int inetd_main __P((int, char **));
109 static int daemon_main __P((int, char **));
110 static void play_service __P((int));
111 static void play_child __P((int, struct sockaddr *));
112 static int faith_prefix __P((struct sockaddr *));
113 static int map6to4 __P((struct sockaddr_in6 *, struct sockaddr_in *));
114 #ifdef FAITH4
115 static int map4to6 __P((struct sockaddr_in *, struct sockaddr_in6 *));
116 #endif
117 static void sig_child __P((int));
118 static void sig_terminate __P((int));
119 static void start_daemon __P((void));
120 static void exit_stderr __P((const char *, ...))
121 	__attribute__((__format__(__printf__, 1, 2)));
122 #ifndef HAVE_GETIFADDRS
123 static unsigned int if_maxindex __P((void));
124 #endif
125 static void grab_myaddrs __P((void));
126 static void free_myaddrs __P((void));
127 static void update_myaddrs __P((void));
128 static void usage __P((void));
129 
130 int
131 main(int argc, char **argv)
132 {
133 
134 	/*
135 	 * Initializing stuff
136 	 */
137 
138 	faithdname = strrchr(argv[0], '/');
139 	if (faithdname)
140 		faithdname++;
141 	else
142 		faithdname = argv[0];
143 
144 	if (strcmp(faithdname, "faithd") != 0) {
145 		inetd = 1;
146 		return inetd_main(argc, argv);
147 	} else
148 		return daemon_main(argc, argv);
149 }
150 
151 static int
152 inetd_main(int argc, char **argv)
153 {
154 	char path[MAXPATHLEN];
155 	struct sockaddr_storage me;
156 	struct sockaddr_storage from;
157 	int melen, fromlen;
158 	int i;
159 	int error;
160 	const int on = 1;
161 	char sbuf[NI_MAXSERV], snum[NI_MAXSERV];
162 
163 	if (strrchr(argv[0], '/') == NULL)
164 		snprintf(path, sizeof(path), "%s/%s", DEFAULT_DIR, argv[0]);
165 	else
166 		snprintf(path, sizeof(path), "%s", argv[0]);
167 
168 #ifdef USE_ROUTE
169 	grab_myaddrs();
170 
171 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
172 	if (sockfd < 0) {
173 		exit_failure("socket(PF_ROUTE): %s", ERRSTR);
174 		/*NOTREACHED*/
175 	}
176 #endif
177 
178 	melen = sizeof(me);
179 	if (getsockname(STDIN_FILENO, (struct sockaddr *)&me, &melen) < 0)
180 		exit_failure("getsockname");
181 	fromlen = sizeof(from);
182 	if (getpeername(STDIN_FILENO, (struct sockaddr *)&from, &fromlen) < 0)
183 		exit_failure("getpeername");
184 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
185 	    sbuf, sizeof(sbuf), NI_NUMERICHOST) == 0)
186 		service = sbuf;
187 	else
188 		service = DEFAULT_PORT_NAME;
189 	if (getnameinfo((struct sockaddr *)&me, melen, NULL, 0,
190 	    snum, sizeof(snum), NI_NUMERICHOST) != 0)
191 		snprintf(snum, sizeof(snum), "?");
192 
193 	snprintf(logname, sizeof(logname), "faithd %s", snum);
194 	snprintf(procname, sizeof(procname), "accepting port %s", snum);
195 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
196 
197 	if (argc >= MAXARGV)
198 		exit_failure("too many arguments");
199 	serverarg[0] = serverpath = path;
200 	for (i = 1; i < argc; i++)
201 		serverarg[i] = argv[i];
202 	serverarg[i] = NULL;
203 
204 	error = setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &on,
205 	    sizeof(on));
206 	if (error < 0)
207 		exit_failure("setsockopt(SO_OOBINLINE): %s", ERRSTR);
208 
209 	play_child(STDIN_FILENO, (struct sockaddr *)&from);
210 	exit_failure("should not reach here");
211 	return 0;	/*dummy!*/
212 }
213 
214 static int
215 daemon_main(int argc, char **argv)
216 {
217 	struct addrinfo hints, *res;
218 	int s_wld, error, i, serverargc, on = 1;
219 	int family = AF_INET6;
220 	int c;
221 #ifdef FAITH_NS
222 	char *ns;
223 #endif /* FAITH_NS */
224 
225 	while ((c = getopt(argc, argv, "dp46")) != -1) {
226 		switch (c) {
227 		case 'd':
228 			dflag++;
229 			break;
230 		case 'p':
231 			pflag++;
232 			break;
233 #ifdef FAITH4
234 		case '4':
235 			family = AF_INET;
236 			break;
237 		case '6':
238 			family = AF_INET6;
239 			break;
240 #endif
241 		default:
242 			usage();
243 			/*NOTREACHED*/
244 		}
245 	}
246 	argc -= optind;
247 	argv += optind;
248 
249 #ifdef FAITH_NS
250 	if ((ns = getenv(FAITH_NS)) != NULL) {
251 		struct sockaddr_storage ss;
252 		struct addrinfo hints, *res;
253 		char serv[NI_MAXSERV];
254 
255 		memset(&ss, 0, sizeof(ss));
256 		memset(&hints, 0, sizeof(hints));
257 		snprintf(serv, sizeof(serv), "%u", NAMESERVER_PORT);
258 		hints.ai_flags = AI_NUMERICHOST;
259 		if (getaddrinfo(ns, serv, &hints, &res) ==  0) {
260 			res_init();
261 			memcpy(&_res_ext.nsaddr, res->ai_addr, res->ai_addrlen);
262 			_res.nscount = 1;
263 		}
264 	}
265 #endif /* FAITH_NS */
266 
267 #ifdef USE_ROUTE
268 	grab_myaddrs();
269 #endif
270 
271 	switch (argc) {
272 	case 0:
273 		usage();
274 		/*NOTREACHED*/
275 	default:
276 		serverargc = argc - NUMARG;
277 		if (serverargc >= MAXARGV)
278 			exit_stderr("too many arguments");
279 
280 		serverpath = malloc(strlen(argv[NUMPRG]) + 1);
281 		strcpy(serverpath, argv[NUMPRG]);
282 		for (i = 0; i < serverargc; i++) {
283 			serverarg[i] = malloc(strlen(argv[i + NUMARG]) + 1);
284 			strcpy(serverarg[i], argv[i + NUMARG]);
285 		}
286 		serverarg[i] = NULL;
287 		/* fall throuth */
288 	case 1:	/* no local service */
289 		service = argv[NUMPRT];
290 		break;
291 	}
292 
293 	/*
294 	 * Opening wild card socket for this service.
295 	 */
296 
297 	memset(&hints, 0, sizeof(hints));
298 	hints.ai_flags = AI_PASSIVE;
299 	hints.ai_family = family;
300 	hints.ai_socktype = SOCK_STREAM;
301 	hints.ai_protocol = 0;
302 	error = getaddrinfo(NULL, service, &hints, &res);
303 	if (error)
304 		exit_stderr("getaddrinfo: %s", gai_strerror(error));
305 
306 	s_wld = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
307 	if (s_wld == -1)
308 		exit_stderr("socket: %s", ERRSTR);
309 
310 #ifdef IPV6_FAITH
311 	if (res->ai_family == AF_INET6) {
312 		error = setsockopt(s_wld, IPPROTO_IPV6, IPV6_FAITH, &on, sizeof(on));
313 		if (error == -1)
314 			exit_stderr("setsockopt(IPV6_FAITH): %s", ERRSTR);
315 	}
316 #endif
317 #ifdef FAITH4
318 #ifdef IP_FAITH
319 	if (res->ai_family == AF_INET) {
320 		error = setsockopt(s_wld, IPPROTO_IP, IP_FAITH, &on, sizeof(on));
321 		if (error == -1)
322 			exit_stderr("setsockopt(IP_FAITH): %s", ERRSTR);
323 	}
324 #endif
325 #endif /* FAITH4 */
326 
327 	error = setsockopt(s_wld, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
328 	if (error == -1)
329 		exit_stderr("setsockopt(SO_REUSEADDR): %s", ERRSTR);
330 
331 	error = setsockopt(s_wld, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
332 	if (error == -1)
333 		exit_stderr("setsockopt(SO_OOBINLINE): %s", ERRSTR);
334 
335 	error = bind(s_wld, (struct sockaddr *)res->ai_addr, res->ai_addrlen);
336 	if (error == -1)
337 		exit_stderr("bind: %s", ERRSTR);
338 
339 	error = listen(s_wld, 5);
340 	if (error == -1)
341 		exit_stderr("listen: %s", ERRSTR);
342 
343 #ifdef USE_ROUTE
344 	sockfd = socket(PF_ROUTE, SOCK_RAW, PF_UNSPEC);
345 	if (sockfd < 0) {
346 		exit_stderr("socket(PF_ROUTE): %s", ERRSTR);
347 		/*NOTREACHED*/
348 	}
349 #endif
350 
351 	/*
352 	 * Everything is OK.
353 	 */
354 
355 	start_daemon();
356 
357 	snprintf(logname, sizeof(logname), "faithd %s", service);
358 	snprintf(procname, sizeof(procname), "accepting port %s", service);
359 	openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
360 	syslog(LOG_INFO, "Starting faith daemon for %s port", service);
361 
362 	play_service(s_wld);
363 	/* NOTREACHED */
364 	exit(1);	/*pacify gcc*/
365 }
366 
367 static void
368 play_service(int s_wld)
369 {
370 	struct sockaddr_storage srcaddr;
371 	int len;
372 	int s_src;
373 	pid_t child_pid;
374 	fd_set rfds;
375 	int error;
376 	int maxfd;
377 
378 	/*
379 	 * Wait, accept, fork, faith....
380 	 */
381 again:
382 	setproctitle("%s", procname);
383 
384 	FD_ZERO(&rfds);
385 	FD_SET(s_wld, &rfds);
386 	maxfd = s_wld;
387 #ifdef USE_ROUTE
388 	if (sockfd) {
389 		FD_SET(sockfd, &rfds);
390 		maxfd = (maxfd < sockfd) ? sockfd : maxfd;
391 	}
392 #endif
393 
394 	error = select(maxfd + 1, &rfds, NULL, NULL, NULL);
395 	if (error < 0) {
396 		if (errno == EINTR)
397 			goto again;
398 		exit_failure("select: %s", ERRSTR);
399 		/*NOTREACHED*/
400 	}
401 
402 #ifdef USE_ROUTE
403 	if (FD_ISSET(sockfd, &rfds)) {
404 		update_myaddrs();
405 	}
406 #endif
407 	if (FD_ISSET(s_wld, &rfds)) {
408 		len = sizeof(srcaddr);
409 		s_src = accept(s_wld, (struct sockaddr *)&srcaddr,
410 			&len);
411 		if (s_src == -1)
412 			exit_failure("socket: %s", ERRSTR);
413 
414 		child_pid = fork();
415 
416 		if (child_pid == 0) {
417 			/* child process */
418 			close(s_wld);
419 			closelog();
420 			openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
421 			play_child(s_src, (struct sockaddr *)&srcaddr);
422 			exit_failure("should never reach here");
423 		} else {
424 			/* parent process */
425 			close(s_src);
426 			if (child_pid == -1)
427 				syslog(LOG_ERR, "can't fork");
428 		}
429 	}
430 	goto again;
431 }
432 
433 static void
434 play_child(int s_src, struct sockaddr *srcaddr)
435 {
436 	struct sockaddr_storage dstaddr6;
437 	struct sockaddr_storage dstaddr4;
438 	char src[MAXHOSTNAMELEN];
439 	char dst6[MAXHOSTNAMELEN];
440 	char dst4[MAXHOSTNAMELEN];
441 	int len = sizeof(dstaddr6);
442 	int s_dst, error, hport, nresvport, on = 1;
443 	struct timeval tv;
444 	struct sockaddr *sa4;
445 
446 	tv.tv_sec = 1;
447 	tv.tv_usec = 0;
448 
449 	getnameinfo(srcaddr, srcaddr->sa_len,
450 		src, sizeof(src), NULL, 0, NI_NUMERICHOST);
451 	syslog(LOG_INFO, "accepted a client from %s", src);
452 
453 	error = getsockname(s_src, (struct sockaddr *)&dstaddr6, &len);
454 	if (error == -1)
455 		exit_failure("getsockname: %s", ERRSTR);
456 
457 	getnameinfo((struct sockaddr *)&dstaddr6, len,
458 		dst6, sizeof(dst6), NULL, 0, NI_NUMERICHOST);
459 	syslog(LOG_INFO, "the client is connecting to %s", dst6);
460 
461 	if (!faith_prefix((struct sockaddr *)&dstaddr6)) {
462 		if (serverpath) {
463 			/*
464 			 * Local service
465 			 */
466 			syslog(LOG_INFO, "executing local %s", serverpath);
467 			if (!inetd) {
468 				dup2(s_src, 0);
469 				close(s_src);
470 				dup2(0, 1);
471 				dup2(0, 2);
472 			}
473 			execv(serverpath, serverarg);
474 			syslog(LOG_ERR, "execv %s: %s", serverpath, ERRSTR);
475 			_exit(EXIT_FAILURE);
476 		} else {
477 			close(s_src);
478 			exit_success("no local service for %s", service);
479 		}
480 	}
481 
482 	/*
483 	 * Act as a translator
484 	 */
485 
486 	switch (((struct sockaddr *)&dstaddr6)->sa_family) {
487 	case AF_INET6:
488 		if (!map6to4((struct sockaddr_in6 *)&dstaddr6,
489 		    (struct sockaddr_in *)&dstaddr4)) {
490 			close(s_src);
491 			exit_failure("map6to4 failed");
492 		}
493 		syslog(LOG_INFO, "translating from v6 to v4");
494 		break;
495 #ifdef FAITH4
496 	case AF_INET:
497 		if (!map4to6((struct sockaddr_in *)&dstaddr6,
498 		    (struct sockaddr_in6 *)&dstaddr4)) {
499 			close(s_src);
500 			exit_failure("map4to6 failed");
501 		}
502 		syslog(LOG_INFO, "translating from v4 to v6");
503 		break;
504 #endif
505 	default:
506 		close(s_src);
507 		exit_failure("family not supported");
508 		/*NOTREACHED*/
509 	}
510 
511 	sa4 = (struct sockaddr *)&dstaddr4;
512 	getnameinfo(sa4, sa4->sa_len,
513 		dst4, sizeof(dst4), NULL, 0, NI_NUMERICHOST);
514 	syslog(LOG_INFO, "the translator is connecting to %s", dst4);
515 
516 	setproctitle("port %s, %s -> %s", service, src, dst4);
517 
518 	if (sa4->sa_family == AF_INET6)
519 		hport = ntohs(((struct sockaddr_in6 *)&dstaddr4)->sin6_port);
520 	else /* AF_INET */
521 		hport = ntohs(((struct sockaddr_in *)&dstaddr4)->sin_port);
522 
523 	switch (hport) {
524 	case RLOGIN_PORT:
525 	case RSH_PORT:
526 		s_dst = rresvport_af(&nresvport, sa4->sa_family);
527 		break;
528 	default:
529 		if (pflag)
530 			s_dst = rresvport_af(&nresvport, sa4->sa_family);
531 		else
532 			s_dst = socket(sa4->sa_family, SOCK_STREAM, 0);
533 		break;
534 	}
535 	if (s_dst == -1)
536 		exit_failure("socket: %s", ERRSTR);
537 
538 	error = setsockopt(s_dst, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on));
539 	if (error == -1)
540 		exit_failure("setsockopt(SO_OOBINLINE): %s", ERRSTR);
541 
542 	error = setsockopt(s_src, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
543 	if (error == -1)
544 		exit_failure("setsockopt(SO_SNDTIMEO): %s", ERRSTR);
545 	error = setsockopt(s_dst, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
546 	if (error == -1)
547 		exit_failure("setsockopt(SO_SNDTIMEO): %s", ERRSTR);
548 
549 	error = connect(s_dst, sa4, sa4->sa_len);
550 	if (error == -1)
551 		exit_failure("connect: %s", ERRSTR);
552 
553 	switch (hport) {
554 	case FTP_PORT:
555 		ftp_relay(s_src, s_dst);
556 		break;
557 	case RSH_PORT:
558 		rsh_relay(s_src, s_dst);
559 		break;
560 	default:
561 		tcp_relay(s_src, s_dst, service);
562 		break;
563 	}
564 
565 	/* NOTREACHED */
566 }
567 
568 /* 0: non faith, 1: faith */
569 static int
570 faith_prefix(struct sockaddr *dst)
571 {
572 #ifndef USE_ROUTE
573 	int mib[4], size;
574 	struct in6_addr faith_prefix;
575 	struct sockaddr_in6 *dst6 = (struct sockaddr_in *)dst;
576 
577 	if (dst->sa_family != AF_INET6)
578 		return 0;
579 
580 	mib[0] = CTL_NET;
581 	mib[1] = PF_INET6;
582 	mib[2] = IPPROTO_IPV6;
583 	mib[3] = IPV6CTL_FAITH_PREFIX;
584 	size = sizeof(struct in6_addr);
585 	if (sysctl(mib, 4, &faith_prefix, &size, NULL, 0) < 0)
586 		exit_failure("sysctl: %s", ERRSTR);
587 
588 	if (memcmp(dst, &faith_prefix,
589 			sizeof(struct in6_addr) - sizeof(struct in_addr) == 0) {
590 		return 1;
591 	}
592 	return 0;
593 #else
594 	struct myaddrs *p;
595 	struct sockaddr_in6 *sin6;
596 	struct sockaddr_in *sin4;
597 	struct sockaddr_in6 *dst6;
598 	struct sockaddr_in *dst4;
599 	struct sockaddr_in dstmap;
600 
601 	dst6 = (struct sockaddr_in6 *)dst;
602 	if (dst->sa_family == AF_INET6
603 	 && IN6_IS_ADDR_V4MAPPED(&dst6->sin6_addr)) {
604 		/* ugly... */
605 		memset(&dstmap, 0, sizeof(dstmap));
606 		dstmap.sin_family = AF_INET;
607 		dstmap.sin_len = sizeof(dstmap);
608 		memcpy(&dstmap.sin_addr, &dst6->sin6_addr.s6_addr[12],
609 			sizeof(dstmap.sin_addr));
610 		dst = (struct sockaddr *)&dstmap;
611 	}
612 
613 	dst6 = (struct sockaddr_in6 *)dst;
614 	dst4 = (struct sockaddr_in *)dst;
615 
616 	for (p = myaddrs; p; p = p->next) {
617 		sin6 = (struct sockaddr_in6 *)p->addr;
618 		sin4 = (struct sockaddr_in *)p->addr;
619 
620 		if (p->addr->sa_len != dst->sa_len
621 		 || p->addr->sa_family != dst->sa_family)
622 			continue;
623 
624 		switch (dst->sa_family) {
625 		case AF_INET6:
626 			if (sin6->sin6_scope_id == dst6->sin6_scope_id
627 			 && IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &dst6->sin6_addr))
628 				return 0;
629 			break;
630 		case AF_INET:
631 			if (sin4->sin_addr.s_addr == dst4->sin_addr.s_addr)
632 				return 0;
633 			break;
634 		}
635 	}
636 	return 1;
637 #endif
638 }
639 
640 /* 0: non faith, 1: faith */
641 static int
642 map6to4(struct sockaddr_in6 *dst6, struct sockaddr_in *dst4)
643 {
644 	memset(dst4, 0, sizeof(*dst4));
645 	dst4->sin_len = sizeof(*dst4);
646 	dst4->sin_family = AF_INET;
647 	dst4->sin_port = dst6->sin6_port;
648 	memcpy(&dst4->sin_addr, &dst6->sin6_addr.s6_addr[12],
649 		sizeof(dst4->sin_addr));
650 
651 	if (dst4->sin_addr.s_addr == INADDR_ANY
652 	 || dst4->sin_addr.s_addr == INADDR_BROADCAST
653 	 || IN_MULTICAST(ntohl(dst4->sin_addr.s_addr)))
654 		return 0;
655 
656 	return 1;
657 }
658 
659 #ifdef FAITH4
660 /* 0: non faith, 1: faith */
661 static int
662 map4to6(struct sockaddr_in *dst4, struct sockaddr_in6 *dst6)
663 {
664 	char host[NI_MAXHOST];
665 	char serv[NI_MAXSERV];
666 	struct addrinfo hints, *res;
667 	int ai_errno;
668 
669 	if (getnameinfo((struct sockaddr *)dst4, dst4->sin_len, host, sizeof(host),
670 			serv, sizeof(serv), NI_NAMEREQD|NI_NUMERICSERV) != 0)
671 		return 0;
672 
673 	memset(&hints, 0, sizeof(hints));
674 	hints.ai_flags = 0;
675 	hints.ai_family = AF_INET6;
676 	hints.ai_socktype = SOCK_STREAM;
677 	hints.ai_protocol = 0;
678 
679 	if ((ai_errno = getaddrinfo(host, serv, &hints, &res)) != 0) {
680 		syslog(LOG_INFO, "%s %s: %s", host, serv, gai_strerror(ai_errno));
681 		return 0;
682 	}
683 
684 	memcpy(dst6, res->ai_addr, res->ai_addrlen);
685 
686 	freeaddrinfo(res);
687 
688 	return 1;
689 }
690 #endif /* FAITH4 */
691 
692 static void
693 sig_child(int sig)
694 {
695 	int status;
696 	pid_t pid;
697 
698 	pid = wait3(&status, WNOHANG, (struct rusage *)0);
699 	if (pid && WEXITSTATUS(status))
700 		syslog(LOG_WARNING, "child %d exit status 0x%x", pid, status);
701 }
702 
703 void
704 sig_terminate(int sig)
705 {
706 	syslog(LOG_INFO, "Terminating faith daemon");
707 	exit(EXIT_SUCCESS);
708 }
709 
710 static void
711 start_daemon(void)
712 {
713 	if (daemon(0, 0) == -1)
714 		exit_stderr("daemon: %s", ERRSTR);
715 
716 	if (signal(SIGCHLD, sig_child) == SIG_ERR)
717 		exit_failure("signal CHLD: %s", ERRSTR);
718 
719 	if (signal(SIGTERM, sig_terminate) == SIG_ERR)
720 		exit_failure("signal TERM: %s", ERRSTR);
721 }
722 
723 static void
724 exit_stderr(const char *fmt, ...)
725 {
726 	va_list ap;
727 	char buf[BUFSIZ];
728 
729 	va_start(ap, fmt);
730 	vsnprintf(buf, sizeof(buf), fmt, ap);
731 	va_end(ap);
732 	fprintf(stderr, "%s", buf);
733 	exit(EXIT_FAILURE);
734 }
735 
736 void
737 exit_failure(const char *fmt, ...)
738 {
739 	va_list ap;
740 	char buf[BUFSIZ];
741 
742 	va_start(ap, fmt);
743 	vsnprintf(buf, sizeof(buf), fmt, ap);
744 	va_end(ap);
745 	syslog(LOG_ERR, "%s", buf);
746 	exit(EXIT_FAILURE);
747 }
748 
749 void
750 exit_success(const char *fmt, ...)
751 {
752 	va_list ap;
753 	char buf[BUFSIZ];
754 
755 	va_start(ap, fmt);
756 	vsnprintf(buf, sizeof(buf), fmt, ap);
757 	va_end(ap);
758 	syslog(LOG_INFO, "%s", buf);
759 	exit(EXIT_SUCCESS);
760 }
761 
762 #ifdef USE_ROUTE
763 #ifndef HAVE_GETIFADDRS
764 static unsigned int
765 if_maxindex()
766 {
767 	struct if_nameindex *p, *p0;
768 	unsigned int max = 0;
769 
770 	p0 = if_nameindex();
771 	for (p = p0; p && p->if_index && p->if_name; p++) {
772 		if (max < p->if_index)
773 			max = p->if_index;
774 	}
775 	if_freenameindex(p0);
776 	return max;
777 }
778 #endif
779 
780 static void
781 grab_myaddrs()
782 {
783 #ifdef HAVE_GETIFADDRS
784 	struct ifaddrs *ifap, *ifa;
785 	struct myaddrs *p;
786 	struct sockaddr_in6 *sin6;
787 
788 	if (getifaddrs(&ifap) != 0) {
789 		exit_failure("getifaddrs");
790 		/*NOTREACHED*/
791 	}
792 
793 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
794 		switch (ifa->ifa_addr->sa_family) {
795 		case AF_INET:
796 		case AF_INET6:
797 			break;
798 		default:
799 			continue;
800 		}
801 
802 		p = (struct myaddrs *)malloc(sizeof(struct myaddrs) +
803 		    ifa->ifa_addr->sa_len);
804 		if (!p) {
805 			exit_failure("not enough core");
806 			/*NOTREACHED*/
807 		}
808 		memcpy(p + 1, ifa->ifa_addr, ifa->ifa_addr->sa_len);
809 		p->next = myaddrs;
810 		p->addr = (struct sockaddr *)(p + 1);
811 #ifdef __KAME__
812 		if (ifa->ifa_addr->sa_family == AF_INET6) {
813 			sin6 = (struct sockaddr_in6 *)p->addr;
814 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)
815 			 || IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) {
816 				sin6->sin6_scope_id =
817 					ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
818 				sin6->sin6_addr.s6_addr[2] = 0;
819 				sin6->sin6_addr.s6_addr[3] = 0;
820 			}
821 		}
822 #endif
823 		myaddrs = p;
824 		if (dflag) {
825 			char hbuf[NI_MAXHOST];
826 			getnameinfo(p->addr, p->addr->sa_len,
827 				hbuf, sizeof(hbuf), NULL, 0,
828 				NI_NUMERICHOST);
829 			syslog(LOG_INFO, "my interface: %s %s", hbuf,
830 			    ifa->ifa_name);
831 		}
832 	}
833 
834 	freeifaddrs(ifap);
835 #else
836 	int s;
837 	unsigned int maxif;
838 	struct ifreq *iflist;
839 	struct ifconf ifconf;
840 	struct ifreq *ifr, *ifrp, *ifr_end;
841 	struct myaddrs *p;
842 	struct sockaddr_in6 *sin6;
843 	size_t siz;
844 	char ifrbuf[sizeof(struct ifreq) + 1024];
845 
846 	maxif = if_maxindex() + 1;
847 	iflist = (struct ifreq *)malloc(maxif * BUFSIZ);	/* XXX */
848 	if (!iflist) {
849 		exit_failure("not enough core");
850 		/*NOTREACHED*/
851 	}
852 
853 	if ((s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
854 		exit_failure("socket(SOCK_DGRAM)");
855 		/*NOTREACHED*/
856 	}
857 	memset(&ifconf, 0, sizeof(ifconf));
858 	ifconf.ifc_req = iflist;
859 	ifconf.ifc_len = maxif * BUFSIZ;	/* XXX */
860 	if (ioctl(s, SIOCGIFCONF, &ifconf) < 0) {
861 		exit_failure("ioctl(SIOCGIFCONF)");
862 		/*NOTREACHED*/
863 	}
864 	close(s);
865 
866 	/* Look for this interface in the list */
867 	ifr_end = (struct ifreq *) (ifconf.ifc_buf + ifconf.ifc_len);
868 	for (ifrp = ifconf.ifc_req;
869 	     ifrp < ifr_end;
870 	     ifrp = (struct ifreq *)((char *)ifrp + siz)) {
871 		memcpy(ifrbuf, ifrp, sizeof(*ifrp));
872 		ifr = (struct ifreq *)ifrbuf;
873 		siz = ifr->ifr_addr.sa_len;
874 		if (siz < sizeof(ifr->ifr_addr))
875 			siz = sizeof(ifr->ifr_addr);
876 		siz += (sizeof(*ifrp) - sizeof(ifr->ifr_addr));
877 		if (siz > sizeof(ifrbuf)) {
878 			/* ifr too big */
879 			break;
880 		}
881 		memcpy(ifrbuf, ifrp, siz);
882 
883 		switch (ifr->ifr_addr.sa_family) {
884 		case AF_INET:
885 		case AF_INET6:
886 			p = (struct myaddrs *)malloc(sizeof(struct myaddrs)
887 				+ ifr->ifr_addr.sa_len);
888 			if (!p) {
889 				exit_failure("not enough core");
890 				/*NOTREACHED*/
891 			}
892 			memcpy(p + 1, &ifr->ifr_addr, ifr->ifr_addr.sa_len);
893 			p->next = myaddrs;
894 			p->addr = (struct sockaddr *)(p + 1);
895 #ifdef __KAME__
896 			if (ifr->ifr_addr.sa_family == AF_INET6) {
897 				sin6 = (struct sockaddr_in6 *)p->addr;
898 				if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)
899 				 || IN6_IS_ADDR_SITELOCAL(&sin6->sin6_addr)) {
900 					sin6->sin6_scope_id =
901 						ntohs(*(u_int16_t *)&sin6->sin6_addr.s6_addr[2]);
902 					sin6->sin6_addr.s6_addr[2] = 0;
903 					sin6->sin6_addr.s6_addr[3] = 0;
904 				}
905 			}
906 #endif
907 			myaddrs = p;
908 			if (dflag) {
909 				char hbuf[NI_MAXHOST];
910 				getnameinfo(p->addr, p->addr->sa_len,
911 					hbuf, sizeof(hbuf), NULL, 0,
912 					NI_NUMERICHOST);
913 				syslog(LOG_INFO, "my interface: %s %s", hbuf, ifr->ifr_name);
914 			}
915 			break;
916 		default:
917 			break;
918 		}
919 	}
920 
921 	free(iflist);
922 #endif
923 }
924 
925 static void
926 free_myaddrs()
927 {
928 	struct myaddrs *p, *q;
929 
930 	p = myaddrs;
931 	while (p) {
932 		q = p->next;
933 		free(p);
934 		p = q;
935 	}
936 	myaddrs = NULL;
937 }
938 
939 static void
940 update_myaddrs()
941 {
942 	char msg[BUFSIZ];
943 	int len;
944 	struct rt_msghdr *rtm;
945 
946 	len = read(sockfd, msg, sizeof(msg));
947 	if (len < 0) {
948 		syslog(LOG_ERR, "read(PF_ROUTE) failed");
949 		return;
950 	}
951 	rtm = (struct rt_msghdr *)msg;
952 	if (len < 4 || len < rtm->rtm_msglen) {
953 		syslog(LOG_ERR, "read(PF_ROUTE) short read");
954 		return;
955 	}
956 	if (rtm->rtm_version != RTM_VERSION) {
957 		syslog(LOG_ERR, "routing socket version mismatch");
958 		close(sockfd);
959 		sockfd = 0;
960 		return;
961 	}
962 	switch (rtm->rtm_type) {
963 	case RTM_NEWADDR:
964 	case RTM_DELADDR:
965 	case RTM_IFINFO:
966 		break;
967 	default:
968 		return;
969 	}
970 	/* XXX more filters here? */
971 
972 	syslog(LOG_INFO, "update interface address list");
973 	free_myaddrs();
974 	grab_myaddrs();
975 }
976 #endif /*USE_ROUTE*/
977 
978 static void
979 usage()
980 {
981 	fprintf(stderr, "usage: %s [-dp] service [serverpath [serverargs]]\n",
982 		faithdname);
983 	exit(0);
984 }
985