xref: /netbsd-src/usr.sbin/rtadvd/rtadvd.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /*	$NetBSD: rtadvd.c,v 1.9 2000/05/23 11:37:59 itojun Exp $	*/
2 /*	$KAME: rtadvd.c,v 1.26 2000/05/23 11:31:26 itojun Exp $	*/
3 
4 /*
5  * Copyright (C) 1995, 1996, 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 #include <sys/param.h>
34 #include <sys/socket.h>
35 #include <sys/uio.h>
36 #include <sys/time.h>
37 
38 #include <net/if.h>
39 #include <net/route.h>
40 #include <net/if_dl.h>
41 #include <netinet/in.h>
42 #include <netinet/ip6.h>
43 #include <netinet6/ip6_var.h>
44 #include <netinet/icmp6.h>
45 
46 #include <arpa/inet.h>
47 
48 #include <time.h>
49 #include <unistd.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <string.h>
55 #include <stdlib.h>
56 #include <syslog.h>
57 #include "rtadvd.h"
58 #include "rrenum.h"
59 #include "advcap.h"
60 #include "timer.h"
61 #include "if.h"
62 #include "config.h"
63 #include "dump.h"
64 
65 struct msghdr rcvmhdr;
66 static u_char *rcvcmsgbuf;
67 static size_t rcvcmsgbuflen;
68 static u_char *sndcmsgbuf = NULL;
69 static size_t sndcmsgbuflen;
70 static int do_dump;
71 struct msghdr sndmhdr;
72 struct iovec rcviov[2];
73 struct iovec sndiov[2];
74 struct sockaddr_in6 from;
75 struct sockaddr_in6 sin6_allnodes = {sizeof(sin6_allnodes), AF_INET6};
76 static char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX: should be configurable */
77 static char *pidfilename = "/var/run/rtadvd.pid"; /* should be configurable */
78 int sock, rtsock;
79 #ifdef MIP6
80 int mobileip6 = 0;
81 #endif
82 int accept_rr = 0;
83 int dflag = 0, sflag = 0;
84 
85 u_char *conffile = NULL;
86 
87 struct rainfo *ralist = NULL;
88 struct nd_optlist {
89 	struct nd_optlist *next;
90 	struct nd_opt_hdr *opt;
91 };
92 union nd_opts {
93 	struct nd_opt_hdr *nd_opt_array[7];
94 	struct {
95 		struct nd_opt_hdr *zero;
96 		struct nd_opt_hdr *src_lladdr;
97 		struct nd_opt_hdr *tgt_lladdr;
98 		struct nd_opt_prefix_info *pi;
99 		struct nd_opt_rd_hdr *rh;
100 		struct nd_opt_mtu *mtu;
101 		struct nd_optlist *list;
102 	} nd_opt_each;
103 };
104 #define nd_opts_src_lladdr	nd_opt_each.src_lladdr
105 #define nd_opts_tgt_lladdr	nd_opt_each.tgt_lladdr
106 #define nd_opts_pi		nd_opt_each.pi
107 #define nd_opts_rh		nd_opt_each.rh
108 #define nd_opts_mtu		nd_opt_each.mtu
109 #define nd_opts_list		nd_opt_each.list
110 
111 #define NDOPT_FLAG_SRCLINKADDR 0x1
112 #define NDOPT_FLAG_TGTLINKADDR 0x2
113 #define NDOPT_FLAG_PREFIXINFO 0x4
114 #define NDOPT_FLAG_RDHDR 0x8
115 #define NDOPT_FLAG_MTU 0x10
116 
117 u_int32_t ndopt_flags[] = {
118 	0, NDOPT_FLAG_SRCLINKADDR, NDOPT_FLAG_TGTLINKADDR,
119 	NDOPT_FLAG_PREFIXINFO, NDOPT_FLAG_RDHDR, NDOPT_FLAG_MTU
120 };
121 
122 int main __P((int, char *[]));
123 static void die __P((int));
124 static void sock_open __P((void));
125 static void rtsock_open __P((void));
126 static void rtadvd_input __P((void));
127 static void rs_input __P((int, struct nd_router_solicit *,
128 			  struct in6_pktinfo *, struct sockaddr_in6 *));
129 static void ra_input __P((int, struct nd_router_advert *,
130 			  struct in6_pktinfo *, struct sockaddr_in6 *));
131 static int prefix_check __P((struct nd_opt_prefix_info *, struct rainfo *,
132 			     struct sockaddr_in6 *));
133 static int nd6_options __P((struct nd_opt_hdr *, int,
134 			    union nd_opts *, u_int32_t));
135 static void free_ndopts __P((union nd_opts *));
136 static struct rainfo *if_indextorainfo __P((int));
137 static void ra_output __P((struct rainfo *));
138 static void rtmsg_input __P((void));
139 static void rtadvd_set_dump_file __P((void));
140 
141 struct prefix *find_prefix __P((struct rainfo *, struct in6_addr *, int));
142 
143 int
144 main(argc, argv)
145 	int argc;
146 	char *argv[];
147 {
148 	fd_set fdset;
149 	int maxfd = 0;
150 	struct timeval *timeout;
151 	int i, ch;
152 	int fflag = 0;
153 	FILE *pidfp;
154 	pid_t pid;
155 
156 	openlog("rtadvd", LOG_NDELAY|LOG_PID, LOG_DAEMON);
157 
158 	/* get command line options and arguments */
159 #ifdef MIP6
160 #define OPTIONS "c:dDfmRs"
161 #else
162 #define OPTIONS "c:dDfRs"
163 #endif
164 	while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
165 #undef OPTIONS
166 		switch(ch) {
167 		 case 'c':
168 			 conffile = optarg;
169 			 break;
170 		 case 'd':
171 			 dflag = 1;
172 			 break;
173 		 case 'D':
174 			 dflag = 2;
175 			 break;
176 		 case 'f':
177 			 fflag = 1;
178 			 break;
179 #ifdef MIP6
180 		 case 'm':
181 			 mobileip6 = 1;
182 			 break;
183 #endif
184 		 case 'R':
185 			 accept_rr = 1;
186 			 break;
187 		 case 's':
188 			 sflag = 1;
189 			 break;
190 		}
191 	}
192 	argc -= optind;
193 	argv += optind;
194 	if (argc == 0) {
195 		fprintf(stderr,
196 #ifdef MIP6
197 			"usage: rtadvd [-dDfmRs] [-c conffile] "
198 #else
199 			"usage: rtadvd [-dDfRs] [-c conffile] "
200 #endif
201 			"interfaces...\n");
202 		exit(1);
203 	}
204 
205 	/* set log level */
206 	if (dflag == 0)
207 		(void)setlogmask(LOG_UPTO(LOG_ERR));
208 	if (dflag == 1)
209 		(void)setlogmask(LOG_UPTO(LOG_INFO));
210 
211 	/* timer initialization */
212 	rtadvd_timer_init();
213 
214 	/* random value initialization */
215 	srandom((u_long)time(NULL));
216 
217 	/* get iflist block from kernel */
218 	init_iflist();
219 
220 	while (argc--)
221 		getconfig(*argv++);
222 
223 	if (inet_pton(AF_INET6, ALLNODES, &sin6_allnodes.sin6_addr) != 1) {
224 		fprintf(stderr, "fatal: inet_pton failed\n");
225 		exit(1);
226 	}
227 	sock_open();
228 
229 	if (!fflag)
230 		daemon(1, 0);
231 
232 	/* record the current PID */
233 	pid = getpid();
234 	if ((pidfp = fopen(pidfilename, "w")) == NULL)
235 		syslog(LOG_ERR,
236 		       "<%s> failed to open a log file(%s), run anyway.",
237 		       __FUNCTION__, pidfilename);
238 	else {
239 		fprintf(pidfp, "%d\n", pid);
240 		fclose(pidfp);
241 	}
242 
243 	FD_ZERO(&fdset);
244 	FD_SET(sock, &fdset);
245 	maxfd = sock;
246 	if (sflag == 0) {
247 		rtsock_open();
248 		FD_SET(rtsock, &fdset);
249 		if (rtsock > sock)
250 			maxfd = rtsock;
251 	}
252 
253 	signal(SIGTERM, (void *)die);
254 	signal(SIGUSR1, (void *)rtadvd_set_dump_file);
255 
256 	while (1) {
257 		struct fd_set select_fd = fdset; /* reinitialize */
258 
259 		if (do_dump) {	/* SIGUSR1 */
260 			do_dump = 0;
261 			rtadvd_dump_file(dumpfilename);
262 		}
263 
264 		/* timer expiration check and reset the timer */
265 		timeout = rtadvd_check_timer();
266 
267 		syslog(LOG_DEBUG,
268 		       "<%s> set timer to %ld:%ld. waiting for inputs "
269 		       "or timeout",
270 		       __FUNCTION__,
271 		       (long int)timeout->tv_sec, (long int)timeout->tv_usec);
272 
273 		if ((i = select(maxfd + 1, &select_fd,
274 				NULL, NULL, timeout)) < 0) {
275 			/* EINTR would occur upon SIGUSR1 for status dump */
276 			if (errno != EINTR)
277 				syslog(LOG_ERR, "<%s> select: %s",
278 				       __FUNCTION__, strerror(errno));
279 			continue;
280 		}
281 		if (i == 0)	/* timeout */
282 			continue;
283 		if (sflag == 0 && FD_ISSET(rtsock, &select_fd))
284 			rtmsg_input();
285 		if (FD_ISSET(sock, &select_fd))
286 			rtadvd_input();
287 	}
288 	exit(0);		/* NOTREACHED */
289 }
290 
291 static void
292 rtadvd_set_dump_file()
293 {
294 	do_dump = 1;
295 }
296 
297 static void
298 die(sig)
299 	int sig;
300 {
301 	struct rainfo *ra;
302 	int i;
303 	const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
304 
305 	if (dflag > 1) {
306 		syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
307 		    __FUNCTION__);
308 	}
309 
310 	for (ra = ralist; ra; ra = ra->next) {
311 		ra->lifetime = 0;
312 		make_packet(ra);
313 	}
314 	for (i = 0; i < retrans; i++) {
315 		for (ra = ralist; ra; ra = ra->next)
316 			ra_output(ra);
317 		sleep(MIN_DELAY_BETWEEN_RAS);
318 	}
319 	exit(0);
320 	/*NOTREACHED*/
321 }
322 
323 static void
324 rtmsg_input()
325 {
326 	int n, type, ifindex = 0, plen;
327 	size_t len;
328 	char msg[2048], *next, *lim;
329 	u_char ifname[16];
330 	struct prefix *prefix;
331 	struct rainfo *rai;
332 	struct in6_addr *addr;
333 	char addrbuf[INET6_ADDRSTRLEN];
334 
335 	n = read(rtsock, msg, 2048);
336 	if (dflag > 1) {
337 		syslog(LOG_DEBUG,
338 		       "<%s> received a routing message "
339 		       "(type = %d, len = %d)",
340 		       __FUNCTION__,
341 		       rtmsg_type(msg), n);
342 	}
343 	if (n > rtmsg_len(msg)) {
344 		/*
345 		 * This usually won't happen for messages received on
346 		 * an routing socket.
347 		 */
348 		if (dflag > 1)
349 			syslog(LOG_DEBUG,
350 			       "<%s> received data length is larger than"
351 			       "1st routing message len. multiple messages?"
352 			       " read %d bytes, but 1st msg len = %d",
353 			       __FUNCTION__, n, rtmsg_len(msg));
354 #if 0
355 		/* adjust length */
356 		n = rtmsg_len(msg);
357 #endif
358 	}
359 
360 	lim = msg + n;
361 	for (next = msg; next < lim; next += len) {
362 		next = get_next_msg(next, lim, 0, &len,
363 				    RTADV_TYPE2BITMASK(RTM_ADD) |
364 				    RTADV_TYPE2BITMASK(RTM_DELETE) |
365 				    RTADV_TYPE2BITMASK(RTM_NEWADDR) |
366 				    RTADV_TYPE2BITMASK(RTM_DELADDR) |
367 				    RTADV_TYPE2BITMASK(RTM_IFINFO));
368 		if (len == 0)
369 			break;
370 		type = rtmsg_type(next);
371 		switch (type) {
372 		case RTM_ADD:
373 		case RTM_DELETE:
374 			ifindex = get_rtm_ifindex(next);
375 			break;
376 		case RTM_NEWADDR:
377 		case RTM_DELADDR:
378 			ifindex = get_ifam_ifindex(next);
379 			break;
380 		case RTM_IFINFO:
381 			ifindex = get_ifm_ifindex(next);
382 			break;
383 		default:
384 			/* should not reach here */
385 			if (dflag > 1) {
386 				syslog(LOG_DEBUG,
387 				       "<%s:%d> unknown rtmsg %d on %s",
388 				       __FUNCTION__, __LINE__, type,
389 				       if_indextoname(ifindex, ifname));
390 			}
391 			return;
392 		}
393 
394 		if ((rai = if_indextorainfo(ifindex)) == NULL) {
395 			if (dflag > 1) {
396 				syslog(LOG_DEBUG,
397 				       "<%s> route changed on "
398 				       "non advertising interface(%s)",
399 				       __FUNCTION__,
400 				       if_indextoname(ifindex, ifname));
401 			}
402 			return;
403 		}
404 
405 		switch(type) {
406 		 case RTM_ADD:
407 			 /* init iffalgs because it may have changed */
408 			 iflist[ifindex]->ifm_flags =
409 			 	if_getflags(ifindex,
410 					    iflist[ifindex]->ifm_flags);
411 
412 			 addr = get_addr(msg);
413 			 plen = get_prefixlen(msg);
414 			 /* sanity check for plen */
415 			 if (plen < 4 /* as RFC2373, prefixlen is at least 4 */
416 			     || plen > 127) {
417 				syslog(LOG_INFO, "<%s> new interface route's"
418 				       "plen %d is invalid for a prefix",
419 				       __FUNCTION__, plen);
420 				return;
421 			 }
422 			 prefix = find_prefix(rai, addr, plen);
423 			 if (prefix) {
424 				 if (dflag > 1) {
425 					 syslog(LOG_DEBUG,
426 						"<%s> new prefix(%s/%d) "
427 						"added on %s, "
428 						"but it was already in list",
429 						__FUNCTION__,
430 						inet_ntop(AF_INET6,
431 							  addr, (char *)addrbuf,
432 							  INET6_ADDRSTRLEN),
433 						plen,
434 						rai->ifname);
435 				 }
436 				 return;
437 			 }
438 			 make_prefix(rai, ifindex, addr, plen);
439 			 break;
440 		 case RTM_DELETE:
441 			 /* init ifflags because it may have changed */
442 			 iflist[ifindex]->ifm_flags =
443 			 	if_getflags(ifindex,
444 					    iflist[ifindex]->ifm_flags);
445 
446 			 addr = get_addr(msg);
447 			 plen = get_prefixlen(msg);
448 			 /* sanity check for plen */
449 			 if (plen < 4 /* as RFC2373, prefixlen is at least 4 */
450 			     || plen > 127) {
451 				syslog(LOG_INFO, "<%s> deleted interface"
452 				       "route's"
453 				       "plen %d is invalid for a prefix",
454 				       __FUNCTION__, plen);
455 				return;
456 			 }
457 			 prefix = find_prefix(rai, addr, plen);
458 			 if (prefix == NULL) {
459 				 if (dflag > 1) {
460 					 syslog(LOG_DEBUG,
461 						"<%s> prefix(%s/%d) was "
462 						"deleted on %s, "
463 						"but it was not in list",
464 						__FUNCTION__,
465 						inet_ntop(AF_INET6,
466 							  addr, (char *)addrbuf,
467 							  INET6_ADDRSTRLEN),
468 						plen,
469 						rai->ifname);
470 				 }
471 				 return;
472 			 }
473 			 delete_prefix(rai, prefix);
474 			 break;
475 		case RTM_NEWADDR:
476 		case RTM_DELADDR:
477 			 /* init ifflags because it may have changed */
478 			 iflist[ifindex]->ifm_flags =
479 			 	if_getflags(ifindex,
480 					    iflist[ifindex]->ifm_flags);
481 			 break;
482 		case RTM_IFINFO:
483 			 iflist[ifindex]->ifm_flags = get_ifm_flags(next);
484 			 break;
485 		default:
486 			/* should not reach here */
487 			if (dflag > 1) {
488 				syslog(LOG_DEBUG,
489 				       "<%s:%d> unknown rtmsg %d on %s",
490 				       __FUNCTION__, __LINE__, type,
491 				       if_indextoname(ifindex, ifname));
492 			}
493 			return;
494 		}
495 	}
496 
497 	return;
498 }
499 
500 void
501 rtadvd_input()
502 {
503 	int i;
504 	int *hlimp = NULL;
505 #ifdef OLDRAWSOCKET
506 	struct ip6_hdr *ip;
507 #endif
508 	struct icmp6_hdr *icp;
509 	int ifindex = 0;
510 	struct cmsghdr *cm;
511 	struct in6_pktinfo *pi = NULL;
512 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
513 	struct in6_addr dst = in6addr_any;
514 
515 	/*
516 	 * Get message. We reset msg_controllen since the field could
517 	 * be modified if we had received a message before setting
518 	 * receive options.
519 	 */
520 	rcvmhdr.msg_controllen = rcvcmsgbuflen;
521 	if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
522 		return;
523 
524 	/* extract optional information via Advanced API */
525 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
526 	     cm;
527 	     cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
528 		if (cm->cmsg_level == IPPROTO_IPV6 &&
529 		    cm->cmsg_type == IPV6_PKTINFO &&
530 		    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
531 			pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
532 			ifindex = pi->ipi6_ifindex;
533 			dst = pi->ipi6_addr;
534 		}
535 		if (cm->cmsg_level == IPPROTO_IPV6 &&
536 		    cm->cmsg_type == IPV6_HOPLIMIT &&
537 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
538 			hlimp = (int *)CMSG_DATA(cm);
539 	}
540 	if (ifindex == 0) {
541 		syslog(LOG_ERR,
542 		       "<%s> failed to get receiving interface",
543 		       __FUNCTION__);
544 		return;
545 	}
546 	if (hlimp == NULL) {
547 		syslog(LOG_ERR,
548 		       "<%s> failed to get receiving hop limit",
549 		       __FUNCTION__);
550 		return;
551 	}
552 
553 #ifdef OLDRAWSOCKET
554 	if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
555 		syslog(LOG_ERR,
556 		       "<%s> packet size(%d) is too short",
557 		       __FUNCTION__, i);
558 		return;
559 	}
560 
561 	ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
562 	icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
563 #else
564 	if (i < sizeof(struct icmp6_hdr)) {
565 		syslog(LOG_ERR,
566 		       "<%s> packet size(%d) is too short",
567 		       __FUNCTION__, i);
568 		return;
569 	}
570 
571 	icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
572 #endif
573 
574 	switch(icp->icmp6_type) {
575 	 case ND_ROUTER_SOLICIT:
576 		 /*
577 		  * Message verification - RFC-2461 6.1.1
578 		  * XXX: these checks must be done in the kernel as well,
579 		  *      but we can't completely rely on them.
580 		  */
581 		 if (*hlimp != 255) {
582 			 syslog(LOG_NOTICE,
583 				"<%s> RS with invalid hop limit(%d) "
584 				"received from %s on %s",
585 				__FUNCTION__, *hlimp,
586 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
587 					  INET6_ADDRSTRLEN),
588 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
589 			 return;
590 		 }
591 		 if (icp->icmp6_code) {
592 			 syslog(LOG_NOTICE,
593 				"<%s> RS with invalid ICMP6 code(%d) "
594 				"received from %s on %s",
595 				__FUNCTION__, icp->icmp6_code,
596 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
597 					  INET6_ADDRSTRLEN),
598 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
599 			 return;
600 		 }
601 		 if (i < sizeof(struct nd_router_solicit)) {
602 			 syslog(LOG_NOTICE,
603 				"<%s> RS from %s on %s does not have enough "
604 				"length (len = %d)",
605 				__FUNCTION__,
606 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
607 					  INET6_ADDRSTRLEN),
608 				if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
609 			 return;
610 		 }
611 		 rs_input(i, (struct nd_router_solicit *)icp, pi, &from);
612 		 break;
613 	 case ND_ROUTER_ADVERT:
614 		 /*
615 		  * Message verification - RFC-2461 6.1.2
616 		  * XXX: there's a same dilemma as above...
617 		  */
618 		 if (*hlimp != 255) {
619 			 syslog(LOG_NOTICE,
620 				"<%s> RA with invalid hop limit(%d) "
621 				"received from %s on %s",
622 				__FUNCTION__, *hlimp,
623 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
624 					  INET6_ADDRSTRLEN),
625 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
626 			 return;
627 		 }
628 		 if (icp->icmp6_code) {
629 			 syslog(LOG_NOTICE,
630 				"<%s> RA with invalid ICMP6 code(%d) "
631 				"received from %s on %s",
632 				__FUNCTION__, icp->icmp6_code,
633 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
634 					  INET6_ADDRSTRLEN),
635 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
636 			 return;
637 		 }
638 		 if (i < sizeof(struct nd_router_advert)) {
639 			 syslog(LOG_NOTICE,
640 				"<%s> RA from %s on %s does not have enough "
641 				"length (len = %d)",
642 				__FUNCTION__,
643 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
644 					  INET6_ADDRSTRLEN),
645 				if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
646 			 return;
647 		 }
648 		 ra_input(i, (struct nd_router_advert *)icp, pi, &from);
649 		 break;
650 	 case ICMP6_ROUTER_RENUMBERING:
651 		 if (accept_rr == 0) {
652 			 syslog(LOG_ERR,
653 				"<%s> received a router renumbering "
654 				"message, but not allowed to be accepted",
655 				__FUNCTION__);
656 			 break;
657 		 }
658 		 rr_input(i, (struct icmp6_router_renum *)icp, pi, &from,
659 			  &dst);
660 		 break;
661 	 default:
662 		 /*
663 		  * Note that this case is POSSIBLE, especially just
664 		  * after invocation of the daemon. This is because we
665 		  * could receive message after opening the socket and
666 		  * before setting ICMP6 type filter(see sock_open()).
667 		  */
668 		 syslog(LOG_ERR,
669 			"<%s> invalid icmp type(%d)",
670 			__FUNCTION__, icp->icmp6_type);
671 		 return;
672 	}
673 
674 	return;
675 }
676 
677 static void
678 rs_input(int len, struct nd_router_solicit *rs,
679 	 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
680 {
681 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
682 	union nd_opts ndopts;
683 	struct rainfo *ra;
684 
685 	syslog(LOG_DEBUG,
686 	       "<%s> RS received from %s on %s",
687 	       __FUNCTION__,
688 	       inet_ntop(AF_INET6, &from->sin6_addr,
689 			 ntopbuf, INET6_ADDRSTRLEN),
690 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
691 
692 	/* ND option check */
693 	memset(&ndopts, 0, sizeof(ndopts));
694 	if (nd6_options((struct nd_opt_hdr *)(rs + 1),
695 			len - sizeof(struct nd_router_solicit),
696 			 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
697 		syslog(LOG_DEBUG,
698 		       "<%s> ND option check failed for an RS from %s on %s",
699 		       __FUNCTION__,
700 		       inet_ntop(AF_INET6, &from->sin6_addr,
701 				 ntopbuf, INET6_ADDRSTRLEN),
702 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
703 		return;
704 	}
705 
706 	/*
707 	 * If the IP source address is the unspecified address, there
708 	 * must be no source link-layer address option in the message.
709 	 * (RFC-2461 6.1.1)
710 	 */
711 	if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
712 	    ndopts.nd_opts_src_lladdr) {
713 		syslog(LOG_ERR,
714 		       "<%s> RS from unspecified src on %s has a link-layer"
715 		       " address option",
716 		       __FUNCTION__,
717 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
718 		goto done;
719 	}
720 
721 	ra = ralist;
722 	while (ra != NULL) {
723 		if (pi->ipi6_ifindex == ra->ifindex)
724 			break;
725 		ra = ra->next;
726 	}
727 	if (ra == NULL) {
728 		syslog(LOG_INFO,
729 		       "<%s> RS received on non advertising interface(%s)",
730 		       __FUNCTION__,
731 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
732 		goto done;
733 	}
734 
735 	ra->rsinput++;		/* increment statistics */
736 
737 	/*
738 	 * Decide whether to send RA according to the rate-limit
739 	 * consideration.
740 	 */
741 	{
742 		long delay;	/* must not be greater than 1000000 */
743 		struct timeval interval, now, min_delay, tm_tmp, *rest;
744 
745 		/*
746 		 * If there is already a waiting RS packet, don't
747 		 * update the timer.
748 		 */
749 		if (ra->waiting++)
750 			goto done;
751 
752 		/*
753 		 * Compute a random delay. If the computed value
754 		 * corresponds to a time later than the time the next
755 		 * multicast RA is scheduled to be sent, ignore the random
756 		 * delay and send the advertisement at the
757 		 * already-scheduled time. RFC-2461 6.2.6
758 		 */
759 		delay = random() % MAX_RA_DELAY_TIME;
760 		interval.tv_sec = 0;
761 		interval.tv_usec = delay;
762 		rest = rtadvd_timer_rest(ra->timer);
763 		if (TIMEVAL_LT(*rest, interval)) {
764 			syslog(LOG_DEBUG,
765 			       "<%s> random delay is larger than "
766 			       "the rest of normal timer",
767 			       __FUNCTION__);
768 			interval = *rest;
769 		}
770 
771 		/*
772 		 * If we sent a multicast Router Advertisement within
773 		 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
774 		 * the advertisement to be sent at a time corresponding to
775 		 * MIN_DELAY_BETWEEN_RAS plus the random value after the
776 		 * previous advertisement was sent.
777 		 */
778 		gettimeofday(&now, NULL);
779 		TIMEVAL_SUB(&now, &ra->lastsent, &tm_tmp);
780 		min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
781 		min_delay.tv_usec = 0;
782 		if (TIMEVAL_LT(tm_tmp, min_delay)) {
783 			TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
784 			TIMEVAL_ADD(&min_delay, &interval, &interval);
785 		}
786 		rtadvd_set_timer(&interval, ra->timer);
787 			goto done;
788 	}
789 
790   done:
791 	free_ndopts(&ndopts);
792 	return;
793 }
794 
795 static void
796 ra_input(int len, struct nd_router_advert *ra,
797 	 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
798 {
799 	struct rainfo *rai;
800 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
801 	union nd_opts ndopts;
802 	char *on_off[] = {"OFF", "ON"};
803 	u_int32_t reachabletime, retranstimer, mtu;
804 	int inconsistent = 0;
805 
806 	syslog(LOG_DEBUG,
807 	       "<%s> RA received from %s on %s",
808 	       __FUNCTION__,
809 	       inet_ntop(AF_INET6, &from->sin6_addr,
810 			 ntopbuf, INET6_ADDRSTRLEN),
811 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
812 
813 	/* ND option check */
814 	memset(&ndopts, 0, sizeof(ndopts));
815 	if (nd6_options((struct nd_opt_hdr *)(ra + 1),
816 			len - sizeof(struct nd_router_advert),
817 			 &ndopts,
818 			NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
819 		syslog(LOG_ERR,
820 		       "<%s> ND option check failed for an RA from %s on %s",
821 		       __FUNCTION__,
822 		       inet_ntop(AF_INET6, &from->sin6_addr,
823 				 ntopbuf, INET6_ADDRSTRLEN),
824 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
825 		return;
826 	}
827 
828 	/*
829 	 * RA consistency check according to RFC-2461 6.2.7
830 	 */
831 	if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
832 		syslog(LOG_INFO,
833 		       "<%s> received RA from %s on non-advertising"
834 		       " interface(%s)",
835 		       __FUNCTION__,
836 		       inet_ntop(AF_INET6, &from->sin6_addr,
837 				 ntopbuf, INET6_ADDRSTRLEN),
838 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
839 		goto done;
840 	}
841 	rai->rainput++;		/* increment statistics */
842 
843 	/* Cur Hop Limit value */
844 	if (ra->nd_ra_curhoplimit && rai->hoplimit &&
845 	    ra->nd_ra_curhoplimit != rai->hoplimit) {
846 		syslog(LOG_WARNING,
847 		       "<%s> CurHopLimit inconsistent on %s:"
848 		       " %d from %s, %d from us",
849 		       __FUNCTION__,
850 		       rai->ifname,
851 		       ra->nd_ra_curhoplimit,
852 		       inet_ntop(AF_INET6, &from->sin6_addr,
853 				 ntopbuf, INET6_ADDRSTRLEN),
854 		       rai->hoplimit);
855 		inconsistent++;
856 	}
857 	/* M flag */
858 	if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
859 	    rai->managedflg) {
860 		syslog(LOG_WARNING,
861 		       "<%s> M flag inconsistent on %s:"
862 		       " %s from %s, %s from us",
863 		       __FUNCTION__,
864 		       rai->ifname,
865 		       on_off[!rai->managedflg],
866 		       inet_ntop(AF_INET6, &from->sin6_addr,
867 				 ntopbuf, INET6_ADDRSTRLEN),
868 		       on_off[rai->managedflg]);
869 		inconsistent++;
870 	}
871 	/* O flag */
872 	if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
873 	    rai->otherflg) {
874 		syslog(LOG_WARNING,
875 		       "<%s> O flag inconsistent on %s:"
876 		       " %s from %s, %s from us",
877 		       __FUNCTION__,
878 		       rai->ifname,
879 		       on_off[!rai->otherflg],
880 		       inet_ntop(AF_INET6, &from->sin6_addr,
881 				 ntopbuf, INET6_ADDRSTRLEN),
882 		       on_off[rai->otherflg]);
883 		inconsistent++;
884 	}
885 	/* Reachable Time */
886 	reachabletime = ntohl(ra->nd_ra_reachable);
887 	if (reachabletime && rai->reachabletime &&
888 	    reachabletime != rai->reachabletime) {
889 		syslog(LOG_WARNING,
890 		       "<%s> ReachableTime inconsistent on %s:"
891 		       " %d from %s, %d from us",
892 		       __FUNCTION__,
893 		       rai->ifname,
894 		       reachabletime,
895 		       inet_ntop(AF_INET6, &from->sin6_addr,
896 				 ntopbuf, INET6_ADDRSTRLEN),
897 		       rai->reachabletime);
898 		inconsistent++;
899 	}
900 	/* Retrans Timer */
901 	retranstimer = ntohl(ra->nd_ra_retransmit);
902 	if (retranstimer && rai->retranstimer &&
903 	    retranstimer != rai->retranstimer) {
904 		syslog(LOG_WARNING,
905 		       "<%s> RetranceTimer inconsistent on %s:"
906 		       " %d from %s, %d from us",
907 		       __FUNCTION__,
908 		       rai->ifname,
909 		       retranstimer,
910 		       inet_ntop(AF_INET6, &from->sin6_addr,
911 				 ntopbuf, INET6_ADDRSTRLEN),
912 		       rai->retranstimer);
913 		inconsistent++;
914 	}
915 	/* Values in the MTU options */
916 	if (ndopts.nd_opts_mtu) {
917 		mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
918 		if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
919 			syslog(LOG_WARNING,
920 			       "<%s> MTU option value inconsistent on %s:"
921 			       " %d from %s, %d from us",
922 			       __FUNCTION__,
923 			       rai->ifname, mtu,
924 			       inet_ntop(AF_INET6, &from->sin6_addr,
925 					 ntopbuf, INET6_ADDRSTRLEN),
926 			       rai->linkmtu);
927 			inconsistent++;
928 		}
929 	}
930 	/* Preferred and Valid Lifetimes for prefixes */
931 	{
932 		struct nd_optlist *optp = ndopts.nd_opts_list;
933 
934 		if (ndopts.nd_opts_pi) {
935 			if (prefix_check(ndopts.nd_opts_pi, rai, from))
936 				inconsistent++;
937 		}
938 		while (optp) {
939 			if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
940 					 rai, from))
941 				inconsistent++;
942 			optp = optp->next;
943 		}
944 	}
945 
946 	if (inconsistent) {
947 		printf("RA input %d inconsistents\n", inconsistent);
948 		rai->rainconsistent++;
949 	}
950 
951   done:
952 	free_ndopts(&ndopts);
953 	return;
954 }
955 
956 /* return a non-zero value if the received prefix is inconsitent with ours */
957 static int
958 prefix_check(struct nd_opt_prefix_info *pinfo,
959 	     struct rainfo *rai, struct sockaddr_in6 *from)
960 {
961 	u_int32_t preferred_time, valid_time;
962 	struct prefix *pp;
963 	int inconsistent = 0;
964 	u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
965 
966 #if 0				/* impossible */
967 	if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
968 		return(0);
969 #endif
970 
971 	/*
972 	 * log if the adveritsed prefix has link-local scope(sanity check?)
973 	 */
974 	if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
975 		syslog(LOG_INFO,
976 		       "<%s> link-local prefix %s/%d is advertised "
977 		       "from %s on %s",
978 		       __FUNCTION__,
979 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
980 				 prefixbuf, INET6_ADDRSTRLEN),
981 		       pinfo->nd_opt_pi_prefix_len,
982 		       inet_ntop(AF_INET6, &from->sin6_addr,
983 				 ntopbuf, INET6_ADDRSTRLEN),
984 		       rai->ifname);
985 	}
986 
987 	if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
988 			      pinfo->nd_opt_pi_prefix_len)) == NULL) {
989 		syslog(LOG_INFO,
990 		       "<%s> prefix %s/%d from %s on %s is not in our list",
991 		       __FUNCTION__,
992 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
993 				 prefixbuf, INET6_ADDRSTRLEN),
994 		       pinfo->nd_opt_pi_prefix_len,
995 		       inet_ntop(AF_INET6, &from->sin6_addr,
996 				 ntopbuf, INET6_ADDRSTRLEN),
997 		       rai->ifname);
998 		return(0);
999 	}
1000 
1001 	preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1002 	if (preferred_time != pp->preflifetime) {
1003 		syslog(LOG_WARNING,
1004 		       "<%s> prefeerred lifetime for %s/%d"
1005 		       " inconsistent on %s:"
1006 		       " %d from %s, %d from us",
1007 		       __FUNCTION__,
1008 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1009 				 prefixbuf, INET6_ADDRSTRLEN),
1010 		       pinfo->nd_opt_pi_prefix_len,
1011 		       rai->ifname, preferred_time,
1012 		       inet_ntop(AF_INET6, &from->sin6_addr,
1013 				 ntopbuf, INET6_ADDRSTRLEN),
1014 		       pp->preflifetime);
1015 		inconsistent++;
1016 	}
1017 
1018 	valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1019 	if (valid_time != pp->validlifetime) {
1020 		syslog(LOG_WARNING,
1021 		       "<%s> valid lifetime for %s/%d"
1022 		       " inconsistent on %s:"
1023 		       " %d from %s, %d from us",
1024 		       __FUNCTION__,
1025 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1026 				 prefixbuf, INET6_ADDRSTRLEN),
1027 		       pinfo->nd_opt_pi_prefix_len,
1028 		       rai->ifname, valid_time,
1029 		       inet_ntop(AF_INET6, &from->sin6_addr,
1030 				 ntopbuf, INET6_ADDRSTRLEN),
1031 		       pp->validlifetime);
1032 		inconsistent++;
1033 	}
1034 
1035 	return(inconsistent);
1036 }
1037 
1038 struct prefix *
1039 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1040 {
1041 	struct prefix *pp;
1042 	int bytelen, bitlen;
1043 
1044 	for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
1045 		if (plen != pp->prefixlen)
1046 			continue;
1047 		bytelen = plen / 8;
1048 		bitlen = plen % 8;
1049 		if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1050 			continue;
1051 		if (prefix->s6_addr[bytelen] >> (8 - bitlen) ==
1052 		    pp->prefix.s6_addr[bytelen] >> (8 - bitlen))
1053 			return(pp);
1054 	}
1055 
1056 	return(NULL);
1057 }
1058 
1059 static int
1060 nd6_options(struct nd_opt_hdr *hdr, int limit,
1061 	    union nd_opts *ndopts, u_int32_t optflags)
1062 {
1063 	int optlen = 0;
1064 
1065 	for (; limit > 0; limit -= optlen) {
1066 		hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1067 		optlen = hdr->nd_opt_len << 3;
1068 		if (hdr->nd_opt_len == 0) {
1069 			syslog(LOG_ERR,
1070 			       "<%s> bad ND option length(0) (type = %d)",
1071 			       __FUNCTION__, hdr->nd_opt_type);
1072 			goto bad;
1073 		}
1074 
1075 		if (hdr->nd_opt_type > ND_OPT_MTU) {
1076 			syslog(LOG_INFO,
1077 			       "<%s> unknown ND option(type %d)",
1078 			       __FUNCTION__,
1079 			       hdr->nd_opt_type);
1080 			continue;
1081 		}
1082 
1083 		if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1084 			syslog(LOG_INFO,
1085 			       "<%s> unexpected ND option(type %d)",
1086 			       __FUNCTION__,
1087 			       hdr->nd_opt_type);
1088 			continue;
1089 		}
1090 
1091 		switch(hdr->nd_opt_type) {
1092 		 case ND_OPT_SOURCE_LINKADDR:
1093 		 case ND_OPT_TARGET_LINKADDR:
1094 		 case ND_OPT_REDIRECTED_HEADER:
1095 		 case ND_OPT_MTU:
1096 			 if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1097 				 syslog(LOG_INFO,
1098 					"<%s> duplicated ND option"
1099 					" (type = %d)",
1100 					__FUNCTION__,
1101 					hdr->nd_opt_type);
1102 			 }
1103 			 ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1104 			 break;
1105 		 case ND_OPT_PREFIX_INFORMATION:
1106 		 {
1107 			 struct nd_optlist *pfxlist;
1108 
1109 			 if (ndopts->nd_opts_pi == 0) {
1110 				 ndopts->nd_opts_pi =
1111 					 (struct nd_opt_prefix_info *)hdr;
1112 				 continue;
1113 			 }
1114 			 if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1115 				 syslog(LOG_ERR,
1116 					"<%s> can't allocate memory",
1117 					__FUNCTION__);
1118 				 goto bad;
1119 			 }
1120 			 pfxlist->next = ndopts->nd_opts_list;
1121 			 pfxlist->opt = hdr;
1122 			 ndopts->nd_opts_list = pfxlist;
1123 
1124 			 break;
1125 		 }
1126 		 default:	/* impossible */
1127 			 break;
1128 		}
1129 	}
1130 
1131 	return(0);
1132 
1133   bad:
1134 	free_ndopts(ndopts);
1135 
1136 	return(-1);
1137 }
1138 
1139 static void
1140 free_ndopts(union nd_opts *ndopts)
1141 {
1142 	struct nd_optlist *opt = ndopts->nd_opts_list, *next;
1143 
1144 	while(opt) {
1145 		next = opt->next;
1146 		free(opt);
1147 		opt = next;
1148 	}
1149 }
1150 
1151 void
1152 sock_open()
1153 {
1154 	struct icmp6_filter filt;
1155 	struct ipv6_mreq mreq;
1156 	struct rainfo *ra = ralist;
1157 	int on;
1158 	/* XXX: should be max MTU attached to the node */
1159 	static u_char answer[1500];
1160 
1161 	rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1162 				CMSG_SPACE(sizeof(int));
1163 	rcvcmsgbuf = (u_char *)malloc(rcvcmsgbuflen);
1164 	if (rcvcmsgbuf == NULL) {
1165 		syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1166 		exit(1);
1167 	}
1168 
1169 	sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1170 				CMSG_SPACE(sizeof(int));
1171 	sndcmsgbuf = (u_char *)malloc(sndcmsgbuflen);
1172 	if (sndcmsgbuf == NULL) {
1173 		syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1174 		exit(1);
1175 	}
1176 
1177 	if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1178 		syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
1179 		       strerror(errno));
1180 		exit(1);
1181 	}
1182 
1183 	/* specify to tell receiving interface */
1184 	on = 1;
1185 #ifdef IPV6_RECVPKTINFO
1186 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1187 		       sizeof(on)) < 0) {
1188 		syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
1189 		       __FUNCTION__, strerror(errno));
1190 		exit(1);
1191 	}
1192 #else  /* old adv. API */
1193 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1194 		       sizeof(on)) < 0) {
1195 		syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
1196 		       __FUNCTION__, strerror(errno));
1197 		exit(1);
1198 	}
1199 #endif
1200 
1201 	on = 1;
1202 	/* specify to tell value of hoplimit field of received IP6 hdr */
1203 #ifdef IPV6_RECVHOPLIMIT
1204 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1205 		       sizeof(on)) < 0) {
1206 		syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
1207 		       __FUNCTION__, strerror(errno));
1208 		exit(1);
1209 	}
1210 #else  /* old adv. API */
1211 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1212 		       sizeof(on)) < 0) {
1213 		syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
1214 		       __FUNCTION__, strerror(errno));
1215 		exit(1);
1216 	}
1217 #endif
1218 
1219 	ICMP6_FILTER_SETBLOCKALL(&filt);
1220 	ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1221 	ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1222 	if (accept_rr)
1223 		ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1224 	if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1225 		       sizeof(filt)) < 0) {
1226 		syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1227 		       __FUNCTION__, strerror(errno));
1228 		exit(1);
1229 	}
1230 
1231 	/*
1232 	 * join all routers multicast address on each advertising interface.
1233 	 */
1234 	if (inet_pton(AF_INET6, ALLROUTERS, &mreq.ipv6mr_multiaddr.s6_addr)
1235 	    != 1) {
1236 		syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1237 		       __FUNCTION__);
1238 		exit(1);
1239 	}
1240 	while(ra) {
1241 		mreq.ipv6mr_interface = ra->ifindex;
1242 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1243 			       &mreq,
1244 			       sizeof(mreq)) < 0) {
1245 			syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP on %s: %s",
1246 			       __FUNCTION__, ra->ifname, strerror(errno));
1247 			exit(1);
1248 		}
1249 		ra = ra->next;
1250 	}
1251 
1252 	/* initialize msghdr for receiving packets */
1253 	rcviov[0].iov_base = (caddr_t)answer;
1254 	rcviov[0].iov_len = sizeof(answer);
1255 	rcvmhdr.msg_name = (caddr_t)&from;
1256 	rcvmhdr.msg_namelen = sizeof(from);
1257 	rcvmhdr.msg_iov = rcviov;
1258 	rcvmhdr.msg_iovlen = 1;
1259 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1260 	rcvmhdr.msg_controllen = rcvcmsgbuflen;
1261 
1262 	/* initialize msghdr for sending packets */
1263 	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1264 	sndmhdr.msg_iov = sndiov;
1265 	sndmhdr.msg_iovlen = 1;
1266 	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1267 	sndmhdr.msg_controllen = sndcmsgbuflen;
1268 
1269 	return;
1270 }
1271 
1272 /* open a routing socket to watch the routing table */
1273 static void
1274 rtsock_open()
1275 {
1276 	if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1277 		syslog(LOG_ERR,
1278 		       "<%s> socket: %s", __FUNCTION__, strerror(errno));
1279 		exit(1);
1280 	}
1281 }
1282 
1283 static struct rainfo *
1284 if_indextorainfo(int index)
1285 {
1286 	struct rainfo *rai = ralist;
1287 
1288 	for (rai = ralist; rai; rai = rai->next) {
1289 		if (rai->ifindex == index)
1290 			return(rai);
1291 	}
1292 
1293 	return(NULL);		/* search failed */
1294 }
1295 
1296 static void
1297 ra_output(rainfo)
1298 struct rainfo *rainfo;
1299 {
1300 	int i;
1301 
1302 	struct cmsghdr *cm;
1303 	struct in6_pktinfo *pi;
1304 
1305 	sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
1306 	sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
1307 	sndmhdr.msg_iov[0].iov_len = rainfo->ra_datalen;
1308 
1309 	cm = CMSG_FIRSTHDR(&sndmhdr);
1310 	/* specify the outgoing interface */
1311 	cm->cmsg_level = IPPROTO_IPV6;
1312 	cm->cmsg_type = IPV6_PKTINFO;
1313 	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1314 	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1315 	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
1316 	pi->ipi6_ifindex = rainfo->ifindex;
1317 
1318 	/* specify the hop limit of the packet */
1319 	{
1320 		int hoplimit = 255;
1321 
1322 		cm = CMSG_NXTHDR(&sndmhdr, cm);
1323 		cm->cmsg_level = IPPROTO_IPV6;
1324 		cm->cmsg_type = IPV6_HOPLIMIT;
1325 		cm->cmsg_len = CMSG_LEN(sizeof(int));
1326 		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1327 	}
1328 
1329 	syslog(LOG_DEBUG,
1330 	       "<%s> send RA on %s, # of waitings = %d",
1331 	       __FUNCTION__, rainfo->ifname, rainfo->waiting);
1332 
1333 	i = sendmsg(sock, &sndmhdr, 0);
1334 
1335 	if (i < 0 || i != rainfo->ra_datalen)  {
1336 		if (i < 0) {
1337 			syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1338 			       __FUNCTION__, rainfo->ifname,
1339 			       strerror(errno));
1340 		}
1341 	}
1342 
1343 	/* update counter */
1344 	if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1345 		rainfo->initcounter++;
1346 	rainfo->raoutput++;
1347 
1348 	/* update timestamp */
1349 	gettimeofday(&rainfo->lastsent, NULL);
1350 
1351 	/* reset waiting conter */
1352 	rainfo->waiting = 0;
1353 }
1354 
1355 /* process RA timer */
1356 void
1357 ra_timeout(void *data)
1358 {
1359 	struct rainfo *rai = (struct rainfo *)data;
1360 
1361 #ifdef notyet
1362 	/* if necessary, reconstruct the packet. */
1363 #endif
1364 
1365 	syslog(LOG_DEBUG,
1366 	       "<%s> RA timer on %s is expired",
1367 	       __FUNCTION__, rai->ifname);
1368 
1369 	if (iflist[rai->ifindex]->ifm_flags & IFF_UP)
1370 		ra_output(rai);
1371 	else
1372 		syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1373 		       __FUNCTION__, rai->ifname);
1374 }
1375 
1376 /* update RA timer */
1377 void
1378 ra_timer_update(void *data, struct timeval *tm)
1379 {
1380 	struct rainfo *rai = (struct rainfo *)data;
1381 	long interval;
1382 
1383 	/*
1384 	 * Whenever a multicast advertisement is sent from an interface,
1385 	 * the timer is reset to a uniformly-distributed random value
1386 	 * between the interface's configured MinRtrAdvInterval and
1387 	 * MaxRtrAdvInterval(discovery-v2-02 6.2.4).
1388 	 */
1389 	interval = rai->mininterval;
1390 	interval += random() % (rai->maxinterval - rai->mininterval);
1391 
1392 	/*
1393 	 * For the first few advertisements (up to
1394 	 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1395 	 * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1396 	 * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1397 	 * (RFC-2461 6.2.4)
1398 	 */
1399 	if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1400 	    interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1401 		interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1402 
1403 	tm->tv_sec = interval;
1404 	tm->tv_usec = 0;
1405 
1406 	syslog(LOG_DEBUG,
1407 	       "<%s> RA timer on %s is set to %ld:%ld",
1408 	       __FUNCTION__, rai->ifname,
1409 	       (long int)tm->tv_sec, (long int)tm->tv_usec);
1410 
1411 	return;
1412 }
1413