xref: /freebsd/usr.sbin/rtadvd/rtadvd.c (revision 43960f159d60217fcb3c5c03095effdb77a0f291)
1 /*	$FreeBSD$	*/
2 /*	$KAME: rtadvd.c,v 1.30 2000/06/22 20:16:12 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 	rtsock_open();
247 	FD_SET(rtsock, &fdset);
248 	if (rtsock > sock)
249 			maxfd = rtsock;
250 
251 	signal(SIGTERM, (void *)die);
252 	signal(SIGUSR1, (void *)rtadvd_set_dump_file);
253 
254 	while (1) {
255 		struct fd_set select_fd = fdset; /* reinitialize */
256 
257 		if (do_dump) {	/* SIGUSR1 */
258 			do_dump = 0;
259 			rtadvd_dump_file(dumpfilename);
260 		}
261 
262 		/* timer expiration check and reset the timer */
263 		timeout = rtadvd_check_timer();
264 
265 		if (timeout != NULL) {
266 			syslog(LOG_DEBUG,
267 			       "<%s> set timer to %ld:%ld. waiting for "
268 			       "inputs or timeout",
269 			       __FUNCTION__,
270 			       (long int)timeout->tv_sec,
271 			       (long int)timeout->tv_usec);
272 		} else {
273 			syslog(LOG_DEBUG,
274 			       "<%s> there's no timer. waiting for inputs",
275 			       __FUNCTION__);
276 		}
277 
278 		if ((i = select(maxfd + 1, &select_fd,
279 				NULL, NULL, timeout)) < 0) {
280 			/* EINTR would occur upon SIGUSR1 for status dump */
281 			if (errno != EINTR)
282 				syslog(LOG_ERR, "<%s> select: %s",
283 				       __FUNCTION__, strerror(errno));
284 			continue;
285 		}
286 		if (i == 0)	/* timeout */
287 			continue;
288 		if (sflag == 0 && FD_ISSET(rtsock, &select_fd))
289 			rtmsg_input();
290 		if (FD_ISSET(sock, &select_fd))
291 			rtadvd_input();
292 	}
293 	exit(0);		/* NOTREACHED */
294 }
295 
296 static void
297 rtadvd_set_dump_file()
298 {
299 	do_dump = 1;
300 }
301 
302 static void
303 die(sig)
304 	int sig;
305 {
306 	struct rainfo *ra;
307 	int i;
308 	const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
309 
310 	if (dflag > 1) {
311 		syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
312 		    __FUNCTION__);
313 	}
314 
315 	for (ra = ralist; ra; ra = ra->next) {
316 		ra->lifetime = 0;
317 		make_packet(ra);
318 	}
319 	for (i = 0; i < retrans; i++) {
320 		for (ra = ralist; ra; ra = ra->next)
321 			ra_output(ra);
322 		sleep(MIN_DELAY_BETWEEN_RAS);
323 	}
324 	exit(0);
325 	/*NOTREACHED*/
326 }
327 
328 static void
329 rtmsg_input()
330 {
331 	int n, type, ifindex = 0, plen;
332 	size_t len;
333 	char msg[2048], *next, *lim;
334 	u_char ifname[16];
335 	struct prefix *prefix;
336 	struct rainfo *rai;
337 	struct in6_addr *addr;
338 	char addrbuf[INET6_ADDRSTRLEN];
339 
340 	n = read(rtsock, msg, 2048);
341 	if (dflag > 1) {
342 		syslog(LOG_DEBUG,
343 		       "<%s> received a routing message "
344 		       "(type = %d, len = %d)",
345 		       __FUNCTION__,
346 		       rtmsg_type(msg), n);
347 	}
348 	if (n > rtmsg_len(msg)) {
349 		/*
350 		 * This usually won't happen for messages received on
351 		 * a routing socket.
352 		 */
353 		if (dflag > 1)
354 			syslog(LOG_DEBUG,
355 			       "<%s> received data length is larger than"
356 			       "1st routing message len. multiple messages?"
357 			       " read %d bytes, but 1st msg len = %d",
358 			       __FUNCTION__, n, rtmsg_len(msg));
359 #if 0
360 		/* adjust length */
361 		n = rtmsg_len(msg);
362 #endif
363 	}
364 
365 	lim = msg + n;
366 	for (next = msg; next < lim; next += len) {
367 		int oldifflags;
368 
369 		next = get_next_msg(next, lim, 0, &len,
370 				    RTADV_TYPE2BITMASK(RTM_ADD) |
371 				    RTADV_TYPE2BITMASK(RTM_DELETE) |
372 				    RTADV_TYPE2BITMASK(RTM_NEWADDR) |
373 				    RTADV_TYPE2BITMASK(RTM_DELADDR) |
374 				    RTADV_TYPE2BITMASK(RTM_IFINFO));
375 		if (len == 0)
376 			break;
377 		type = rtmsg_type(next);
378 		switch (type) {
379 		case RTM_ADD:
380 		case RTM_DELETE:
381 			ifindex = get_rtm_ifindex(next);
382 			break;
383 		case RTM_NEWADDR:
384 		case RTM_DELADDR:
385 			ifindex = get_ifam_ifindex(next);
386 			break;
387 		case RTM_IFINFO:
388 			ifindex = get_ifm_ifindex(next);
389 			break;
390 		default:
391 			/* should not reach here */
392 			if (dflag > 1) {
393 				syslog(LOG_DEBUG,
394 				       "<%s:%d> unknown rtmsg %d on %s",
395 				       __FUNCTION__, __LINE__, type,
396 				       if_indextoname(ifindex, ifname));
397 			}
398 			continue;
399 		}
400 
401 		if ((rai = if_indextorainfo(ifindex)) == NULL) {
402 			if (dflag > 1) {
403 				syslog(LOG_DEBUG,
404 				       "<%s> route changed on "
405 				       "non advertising interface(%s)",
406 				       __FUNCTION__,
407 				       if_indextoname(ifindex, ifname));
408 			}
409 			continue;
410 		}
411 		oldifflags = iflist[ifindex]->ifm_flags;
412 
413 		switch(type) {
414 		 case RTM_ADD:
415 			 /* init ifflags because it may have changed */
416 			 iflist[ifindex]->ifm_flags =
417 			 	if_getflags(ifindex,
418 					    iflist[ifindex]->ifm_flags);
419 
420 			 if (sflag)
421 				 break;	/* we aren't interested in prefixes  */
422 
423 			 addr = get_addr(msg);
424 			 plen = get_prefixlen(msg);
425 			 /* sanity check for plen */
426 			 if (plen < 4 /* as RFC2373, prefixlen is at least 4 */
427 			     || plen > 127) {
428 				syslog(LOG_INFO, "<%s> new interface route's"
429 				       "plen %d is invalid for a prefix",
430 				       __FUNCTION__, plen);
431 				break;
432 			 }
433 			 prefix = find_prefix(rai, addr, plen);
434 			 if (prefix) {
435 				 if (dflag > 1) {
436 					 syslog(LOG_DEBUG,
437 						"<%s> new prefix(%s/%d) "
438 						"added on %s, "
439 						"but it was already in list",
440 						__FUNCTION__,
441 						inet_ntop(AF_INET6,
442 							  addr, (char *)addrbuf,
443 							  INET6_ADDRSTRLEN),
444 						plen,
445 						rai->ifname);
446 				 }
447 				 break;
448 			 }
449 			 make_prefix(rai, ifindex, addr, plen);
450 			 break;
451 		 case RTM_DELETE:
452 			 /* init ifflags because it may have changed */
453 			 iflist[ifindex]->ifm_flags =
454 			 	if_getflags(ifindex,
455 					    iflist[ifindex]->ifm_flags);
456 
457 			 if (sflag)
458 				 break;
459 
460 			 addr = get_addr(msg);
461 			 plen = get_prefixlen(msg);
462 			 /* sanity check for plen */
463 			 if (plen < 4 /* as RFC2373, prefixlen is at least 4 */
464 			     || plen > 127) {
465 				syslog(LOG_INFO, "<%s> deleted interface"
466 				       "route's"
467 				       "plen %d is invalid for a prefix",
468 				       __FUNCTION__, plen);
469 				break;
470 			 }
471 			 prefix = find_prefix(rai, addr, plen);
472 			 if (prefix == NULL) {
473 				 if (dflag > 1) {
474 					 syslog(LOG_DEBUG,
475 						"<%s> prefix(%s/%d) was "
476 						"deleted on %s, "
477 						"but it was not in list",
478 						__FUNCTION__,
479 						inet_ntop(AF_INET6,
480 							  addr, (char *)addrbuf,
481 							  INET6_ADDRSTRLEN),
482 						plen,
483 						rai->ifname);
484 				 }
485 				 break;
486 			 }
487 			 delete_prefix(rai, prefix);
488 			 break;
489 		case RTM_NEWADDR:
490 		case RTM_DELADDR:
491 			 /* init ifflags because it may have changed */
492 			 iflist[ifindex]->ifm_flags =
493 			 	if_getflags(ifindex,
494 					    iflist[ifindex]->ifm_flags);
495 			 break;
496 		case RTM_IFINFO:
497 			 iflist[ifindex]->ifm_flags = get_ifm_flags(next);
498 			 break;
499 		default:
500 			/* should not reach here */
501 			if (dflag > 1) {
502 				syslog(LOG_DEBUG,
503 				       "<%s:%d> unknown rtmsg %d on %s",
504 				       __FUNCTION__, __LINE__, type,
505 				       if_indextoname(ifindex, ifname));
506 			}
507 			return;
508 		}
509 
510 		/* check if an interface flag is changed */
511 		if ((oldifflags & IFF_UP) != 0 &&	/* UP to DOWN */
512 		    (iflist[ifindex]->ifm_flags & IFF_UP) == 0) {
513 			syslog(LOG_INFO,
514 			       "<%s> interface %s becomes down. stop timer.",
515 			       __FUNCTION__, rai->ifname);
516 			rtadvd_remove_timer(&rai->timer);
517 		}
518 		else if ((oldifflags & IFF_UP) == 0 &&	/* DOWN to UP */
519 			 (iflist[ifindex]->ifm_flags & IFF_UP) != 0) {
520 			syslog(LOG_INFO,
521 			       "<%s> interface %s becomes up. restart timer.",
522 			       __FUNCTION__, rai->ifname);
523 
524 			rai->initcounter = 0; /* reset the counter */
525 			rai->waiting = 0; /* XXX */
526 			rai->timer = rtadvd_add_timer(ra_timeout,
527 						      ra_timer_update,
528 						      rai, rai);
529 			ra_timer_update((void *)rai, &rai->timer->tm);
530 			rtadvd_set_timer(&rai->timer->tm, rai->timer);
531 		}
532 	}
533 
534 	return;
535 }
536 
537 void
538 rtadvd_input()
539 {
540 	int i;
541 	int *hlimp = NULL;
542 #ifdef OLDRAWSOCKET
543 	struct ip6_hdr *ip;
544 #endif
545 	struct icmp6_hdr *icp;
546 	int ifindex = 0;
547 	struct cmsghdr *cm;
548 	struct in6_pktinfo *pi = NULL;
549 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
550 	struct in6_addr dst = in6addr_any;
551 
552 	/*
553 	 * Get message. We reset msg_controllen since the field could
554 	 * be modified if we had received a message before setting
555 	 * receive options.
556 	 */
557 	rcvmhdr.msg_controllen = rcvcmsgbuflen;
558 	if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
559 		return;
560 
561 	/* extract optional information via Advanced API */
562 	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
563 	     cm;
564 	     cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
565 		if (cm->cmsg_level == IPPROTO_IPV6 &&
566 		    cm->cmsg_type == IPV6_PKTINFO &&
567 		    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
568 			pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
569 			ifindex = pi->ipi6_ifindex;
570 			dst = pi->ipi6_addr;
571 		}
572 		if (cm->cmsg_level == IPPROTO_IPV6 &&
573 		    cm->cmsg_type == IPV6_HOPLIMIT &&
574 		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
575 			hlimp = (int *)CMSG_DATA(cm);
576 	}
577 	if (ifindex == 0) {
578 		syslog(LOG_ERR,
579 		       "<%s> failed to get receiving interface",
580 		       __FUNCTION__);
581 		return;
582 	}
583 	if (hlimp == NULL) {
584 		syslog(LOG_ERR,
585 		       "<%s> failed to get receiving hop limit",
586 		       __FUNCTION__);
587 		return;
588 	}
589 
590 	/*
591 	 * If we happen to receive data on an interface which is now down,
592 	 * just discard the data.
593 	 */
594 	if ((iflist[pi->ipi6_ifindex]->ifm_flags & IFF_UP) == 0) {
595 		syslog(LOG_INFO,
596 		       "<%s> received data on a disabled interface (%s)",
597 		       __FUNCTION__,
598 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
599 		return;
600 	}
601 
602 #ifdef OLDRAWSOCKET
603 	if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
604 		syslog(LOG_ERR,
605 		       "<%s> packet size(%d) is too short",
606 		       __FUNCTION__, i);
607 		return;
608 	}
609 
610 	ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
611 	icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
612 #else
613 	if (i < sizeof(struct icmp6_hdr)) {
614 		syslog(LOG_ERR,
615 		       "<%s> packet size(%d) is too short",
616 		       __FUNCTION__, i);
617 		return;
618 	}
619 
620 	icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
621 #endif
622 
623 	switch(icp->icmp6_type) {
624 	 case ND_ROUTER_SOLICIT:
625 		 /*
626 		  * Message verification - RFC-2461 6.1.1
627 		  * XXX: these checks must be done in the kernel as well,
628 		  *      but we can't completely rely on them.
629 		  */
630 		 if (*hlimp != 255) {
631 			 syslog(LOG_NOTICE,
632 				"<%s> RS with invalid hop limit(%d) "
633 				"received from %s on %s",
634 				__FUNCTION__, *hlimp,
635 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
636 					  INET6_ADDRSTRLEN),
637 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
638 			 return;
639 		 }
640 		 if (icp->icmp6_code) {
641 			 syslog(LOG_NOTICE,
642 				"<%s> RS with invalid ICMP6 code(%d) "
643 				"received from %s on %s",
644 				__FUNCTION__, icp->icmp6_code,
645 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
646 					  INET6_ADDRSTRLEN),
647 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
648 			 return;
649 		 }
650 		 if (i < sizeof(struct nd_router_solicit)) {
651 			 syslog(LOG_NOTICE,
652 				"<%s> RS from %s on %s does not have enough "
653 				"length (len = %d)",
654 				__FUNCTION__,
655 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
656 					  INET6_ADDRSTRLEN),
657 				if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
658 			 return;
659 		 }
660 		 rs_input(i, (struct nd_router_solicit *)icp, pi, &from);
661 		 break;
662 	 case ND_ROUTER_ADVERT:
663 		 /*
664 		  * Message verification - RFC-2461 6.1.2
665 		  * XXX: there's a same dilemma as above...
666 		  */
667 		 if (*hlimp != 255) {
668 			 syslog(LOG_NOTICE,
669 				"<%s> RA with invalid hop limit(%d) "
670 				"received from %s on %s",
671 				__FUNCTION__, *hlimp,
672 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
673 					  INET6_ADDRSTRLEN),
674 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
675 			 return;
676 		 }
677 		 if (icp->icmp6_code) {
678 			 syslog(LOG_NOTICE,
679 				"<%s> RA with invalid ICMP6 code(%d) "
680 				"received from %s on %s",
681 				__FUNCTION__, icp->icmp6_code,
682 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
683 					  INET6_ADDRSTRLEN),
684 				if_indextoname(pi->ipi6_ifindex, ifnamebuf));
685 			 return;
686 		 }
687 		 if (i < sizeof(struct nd_router_advert)) {
688 			 syslog(LOG_NOTICE,
689 				"<%s> RA from %s on %s does not have enough "
690 				"length (len = %d)",
691 				__FUNCTION__,
692 				inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
693 					  INET6_ADDRSTRLEN),
694 				if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
695 			 return;
696 		 }
697 		 ra_input(i, (struct nd_router_advert *)icp, pi, &from);
698 		 break;
699 	 case ICMP6_ROUTER_RENUMBERING:
700 		 if (accept_rr == 0) {
701 			 syslog(LOG_ERR,
702 				"<%s> received a router renumbering "
703 				"message, but not allowed to be accepted",
704 				__FUNCTION__);
705 			 break;
706 		 }
707 		 rr_input(i, (struct icmp6_router_renum *)icp, pi, &from,
708 			  &dst);
709 		 break;
710 	 default:
711 		 /*
712 		  * Note that this case is POSSIBLE, especially just
713 		  * after invocation of the daemon. This is because we
714 		  * could receive message after opening the socket and
715 		  * before setting ICMP6 type filter(see sock_open()).
716 		  */
717 		 syslog(LOG_ERR,
718 			"<%s> invalid icmp type(%d)",
719 			__FUNCTION__, icp->icmp6_type);
720 		 return;
721 	}
722 
723 	return;
724 }
725 
726 static void
727 rs_input(int len, struct nd_router_solicit *rs,
728 	 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
729 {
730 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
731 	union nd_opts ndopts;
732 	struct rainfo *ra;
733 
734 	syslog(LOG_DEBUG,
735 	       "<%s> RS received from %s on %s",
736 	       __FUNCTION__,
737 	       inet_ntop(AF_INET6, &from->sin6_addr,
738 			 ntopbuf, INET6_ADDRSTRLEN),
739 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
740 
741 	/* ND option check */
742 	memset(&ndopts, 0, sizeof(ndopts));
743 	if (nd6_options((struct nd_opt_hdr *)(rs + 1),
744 			len - sizeof(struct nd_router_solicit),
745 			 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
746 		syslog(LOG_DEBUG,
747 		       "<%s> ND option check failed for an RS from %s on %s",
748 		       __FUNCTION__,
749 		       inet_ntop(AF_INET6, &from->sin6_addr,
750 				 ntopbuf, INET6_ADDRSTRLEN),
751 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
752 		return;
753 	}
754 
755 	/*
756 	 * If the IP source address is the unspecified address, there
757 	 * must be no source link-layer address option in the message.
758 	 * (RFC-2461 6.1.1)
759 	 */
760 	if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
761 	    ndopts.nd_opts_src_lladdr) {
762 		syslog(LOG_ERR,
763 		       "<%s> RS from unspecified src on %s has a link-layer"
764 		       " address option",
765 		       __FUNCTION__,
766 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
767 		goto done;
768 	}
769 
770 	ra = ralist;
771 	while (ra != NULL) {
772 		if (pi->ipi6_ifindex == ra->ifindex)
773 			break;
774 		ra = ra->next;
775 	}
776 	if (ra == NULL) {
777 		syslog(LOG_INFO,
778 		       "<%s> RS received on non advertising interface(%s)",
779 		       __FUNCTION__,
780 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
781 		goto done;
782 	}
783 
784 	ra->rsinput++;		/* increment statistics */
785 
786 	/*
787 	 * Decide whether to send RA according to the rate-limit
788 	 * consideration.
789 	 */
790 	{
791 		long delay;	/* must not be greater than 1000000 */
792 		struct timeval interval, now, min_delay, tm_tmp, *rest;
793 		struct soliciter *sol;
794 
795 		/*
796 		 * record sockaddr waiting for RA, if possible
797 		 */
798 		sol = (struct soliciter *)malloc(sizeof(*sol));
799 		if (sol) {
800 			sol->addr = *from;
801 			/*XXX RFC2553 need clarification on flowinfo */
802 			sol->addr.sin6_flowinfo = 0;
803 			sol->next = ra->soliciter;
804 			ra->soliciter = sol->next;
805 		}
806 
807 		/*
808 		 * If there is already a waiting RS packet, don't
809 		 * update the timer.
810 		 */
811 		if (ra->waiting++)
812 			goto done;
813 
814 		/*
815 		 * Compute a random delay. If the computed value
816 		 * corresponds to a time later than the time the next
817 		 * multicast RA is scheduled to be sent, ignore the random
818 		 * delay and send the advertisement at the
819 		 * already-scheduled time. RFC-2461 6.2.6
820 		 */
821 		delay = random() % MAX_RA_DELAY_TIME;
822 		interval.tv_sec = 0;
823 		interval.tv_usec = delay;
824 		rest = rtadvd_timer_rest(ra->timer);
825 		if (TIMEVAL_LT(*rest, interval)) {
826 			syslog(LOG_DEBUG,
827 			       "<%s> random delay is larger than "
828 			       "the rest of normal timer",
829 			       __FUNCTION__);
830 			interval = *rest;
831 		}
832 
833 		/*
834 		 * If we sent a multicast Router Advertisement within
835 		 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
836 		 * the advertisement to be sent at a time corresponding to
837 		 * MIN_DELAY_BETWEEN_RAS plus the random value after the
838 		 * previous advertisement was sent.
839 		 */
840 		gettimeofday(&now, NULL);
841 		TIMEVAL_SUB(&now, &ra->lastsent, &tm_tmp);
842 		min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
843 		min_delay.tv_usec = 0;
844 		if (TIMEVAL_LT(tm_tmp, min_delay)) {
845 			TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
846 			TIMEVAL_ADD(&min_delay, &interval, &interval);
847 		}
848 		rtadvd_set_timer(&interval, ra->timer);
849 		goto done;
850 	}
851 
852   done:
853 	free_ndopts(&ndopts);
854 	return;
855 }
856 
857 static void
858 ra_input(int len, struct nd_router_advert *ra,
859 	 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
860 {
861 	struct rainfo *rai;
862 	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
863 	union nd_opts ndopts;
864 	char *on_off[] = {"OFF", "ON"};
865 	u_int32_t reachabletime, retranstimer, mtu;
866 	int inconsistent = 0;
867 
868 	syslog(LOG_DEBUG,
869 	       "<%s> RA received from %s on %s",
870 	       __FUNCTION__,
871 	       inet_ntop(AF_INET6, &from->sin6_addr,
872 			 ntopbuf, INET6_ADDRSTRLEN),
873 	       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
874 
875 	/* ND option check */
876 	memset(&ndopts, 0, sizeof(ndopts));
877 	if (nd6_options((struct nd_opt_hdr *)(ra + 1),
878 			len - sizeof(struct nd_router_advert),
879 			 &ndopts,
880 			NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
881 		syslog(LOG_ERR,
882 		       "<%s> ND option check failed for an RA from %s on %s",
883 		       __FUNCTION__,
884 		       inet_ntop(AF_INET6, &from->sin6_addr,
885 				 ntopbuf, INET6_ADDRSTRLEN),
886 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
887 		return;
888 	}
889 
890 	/*
891 	 * RA consistency check according to RFC-2461 6.2.7
892 	 */
893 	if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
894 		syslog(LOG_INFO,
895 		       "<%s> received RA from %s on non-advertising"
896 		       " interface(%s)",
897 		       __FUNCTION__,
898 		       inet_ntop(AF_INET6, &from->sin6_addr,
899 				 ntopbuf, INET6_ADDRSTRLEN),
900 		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
901 		goto done;
902 	}
903 	rai->rainput++;		/* increment statistics */
904 
905 	/* Cur Hop Limit value */
906 	if (ra->nd_ra_curhoplimit && rai->hoplimit &&
907 	    ra->nd_ra_curhoplimit != rai->hoplimit) {
908 		syslog(LOG_WARNING,
909 		       "<%s> CurHopLimit inconsistent on %s:"
910 		       " %d from %s, %d from us",
911 		       __FUNCTION__,
912 		       rai->ifname,
913 		       ra->nd_ra_curhoplimit,
914 		       inet_ntop(AF_INET6, &from->sin6_addr,
915 				 ntopbuf, INET6_ADDRSTRLEN),
916 		       rai->hoplimit);
917 		inconsistent++;
918 	}
919 	/* M flag */
920 	if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
921 	    rai->managedflg) {
922 		syslog(LOG_WARNING,
923 		       "<%s> M flag inconsistent on %s:"
924 		       " %s from %s, %s from us",
925 		       __FUNCTION__,
926 		       rai->ifname,
927 		       on_off[!rai->managedflg],
928 		       inet_ntop(AF_INET6, &from->sin6_addr,
929 				 ntopbuf, INET6_ADDRSTRLEN),
930 		       on_off[rai->managedflg]);
931 		inconsistent++;
932 	}
933 	/* O flag */
934 	if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
935 	    rai->otherflg) {
936 		syslog(LOG_WARNING,
937 		       "<%s> O flag inconsistent on %s:"
938 		       " %s from %s, %s from us",
939 		       __FUNCTION__,
940 		       rai->ifname,
941 		       on_off[!rai->otherflg],
942 		       inet_ntop(AF_INET6, &from->sin6_addr,
943 				 ntopbuf, INET6_ADDRSTRLEN),
944 		       on_off[rai->otherflg]);
945 		inconsistent++;
946 	}
947 	/* Reachable Time */
948 	reachabletime = ntohl(ra->nd_ra_reachable);
949 	if (reachabletime && rai->reachabletime &&
950 	    reachabletime != rai->reachabletime) {
951 		syslog(LOG_WARNING,
952 		       "<%s> ReachableTime inconsistent on %s:"
953 		       " %d from %s, %d from us",
954 		       __FUNCTION__,
955 		       rai->ifname,
956 		       reachabletime,
957 		       inet_ntop(AF_INET6, &from->sin6_addr,
958 				 ntopbuf, INET6_ADDRSTRLEN),
959 		       rai->reachabletime);
960 		inconsistent++;
961 	}
962 	/* Retrans Timer */
963 	retranstimer = ntohl(ra->nd_ra_retransmit);
964 	if (retranstimer && rai->retranstimer &&
965 	    retranstimer != rai->retranstimer) {
966 		syslog(LOG_WARNING,
967 		       "<%s> RetranceTimer inconsistent on %s:"
968 		       " %d from %s, %d from us",
969 		       __FUNCTION__,
970 		       rai->ifname,
971 		       retranstimer,
972 		       inet_ntop(AF_INET6, &from->sin6_addr,
973 				 ntopbuf, INET6_ADDRSTRLEN),
974 		       rai->retranstimer);
975 		inconsistent++;
976 	}
977 	/* Values in the MTU options */
978 	if (ndopts.nd_opts_mtu) {
979 		mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
980 		if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
981 			syslog(LOG_WARNING,
982 			       "<%s> MTU option value inconsistent on %s:"
983 			       " %d from %s, %d from us",
984 			       __FUNCTION__,
985 			       rai->ifname, mtu,
986 			       inet_ntop(AF_INET6, &from->sin6_addr,
987 					 ntopbuf, INET6_ADDRSTRLEN),
988 			       rai->linkmtu);
989 			inconsistent++;
990 		}
991 	}
992 	/* Preferred and Valid Lifetimes for prefixes */
993 	{
994 		struct nd_optlist *optp = ndopts.nd_opts_list;
995 
996 		if (ndopts.nd_opts_pi) {
997 			if (prefix_check(ndopts.nd_opts_pi, rai, from))
998 				inconsistent++;
999 		}
1000 		while (optp) {
1001 			if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
1002 					 rai, from))
1003 				inconsistent++;
1004 			optp = optp->next;
1005 		}
1006 	}
1007 
1008 	if (inconsistent) {
1009 		printf("RA input %d inconsistents\n", inconsistent);
1010 		rai->rainconsistent++;
1011 	}
1012 
1013   done:
1014 	free_ndopts(&ndopts);
1015 	return;
1016 }
1017 
1018 /* return a non-zero value if the received prefix is inconsitent with ours */
1019 static int
1020 prefix_check(struct nd_opt_prefix_info *pinfo,
1021 	     struct rainfo *rai, struct sockaddr_in6 *from)
1022 {
1023 	u_int32_t preferred_time, valid_time;
1024 	struct prefix *pp;
1025 	int inconsistent = 0;
1026 	u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
1027 
1028 #if 0				/* impossible */
1029 	if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1030 		return(0);
1031 #endif
1032 
1033 	/*
1034 	 * log if the adveritsed prefix has link-local scope(sanity check?)
1035 	 */
1036 	if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
1037 		syslog(LOG_INFO,
1038 		       "<%s> link-local prefix %s/%d is advertised "
1039 		       "from %s on %s",
1040 		       __FUNCTION__,
1041 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1042 				 prefixbuf, INET6_ADDRSTRLEN),
1043 		       pinfo->nd_opt_pi_prefix_len,
1044 		       inet_ntop(AF_INET6, &from->sin6_addr,
1045 				 ntopbuf, INET6_ADDRSTRLEN),
1046 		       rai->ifname);
1047 	}
1048 
1049 	if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1050 			      pinfo->nd_opt_pi_prefix_len)) == NULL) {
1051 		syslog(LOG_INFO,
1052 		       "<%s> prefix %s/%d from %s on %s is not in our list",
1053 		       __FUNCTION__,
1054 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1055 				 prefixbuf, INET6_ADDRSTRLEN),
1056 		       pinfo->nd_opt_pi_prefix_len,
1057 		       inet_ntop(AF_INET6, &from->sin6_addr,
1058 				 ntopbuf, INET6_ADDRSTRLEN),
1059 		       rai->ifname);
1060 		return(0);
1061 	}
1062 
1063 	preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1064 	if (preferred_time != pp->preflifetime) {
1065 		syslog(LOG_WARNING,
1066 		       "<%s> prefeerred lifetime for %s/%d"
1067 		       " inconsistent on %s:"
1068 		       " %d from %s, %d from us",
1069 		       __FUNCTION__,
1070 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1071 				 prefixbuf, INET6_ADDRSTRLEN),
1072 		       pinfo->nd_opt_pi_prefix_len,
1073 		       rai->ifname, preferred_time,
1074 		       inet_ntop(AF_INET6, &from->sin6_addr,
1075 				 ntopbuf, INET6_ADDRSTRLEN),
1076 		       pp->preflifetime);
1077 		inconsistent++;
1078 	}
1079 
1080 	valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1081 	if (valid_time != pp->validlifetime) {
1082 		syslog(LOG_WARNING,
1083 		       "<%s> valid lifetime for %s/%d"
1084 		       " inconsistent on %s:"
1085 		       " %d from %s, %d from us",
1086 		       __FUNCTION__,
1087 		       inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1088 				 prefixbuf, INET6_ADDRSTRLEN),
1089 		       pinfo->nd_opt_pi_prefix_len,
1090 		       rai->ifname, valid_time,
1091 		       inet_ntop(AF_INET6, &from->sin6_addr,
1092 				 ntopbuf, INET6_ADDRSTRLEN),
1093 		       pp->validlifetime);
1094 		inconsistent++;
1095 	}
1096 
1097 	return(inconsistent);
1098 }
1099 
1100 struct prefix *
1101 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1102 {
1103 	struct prefix *pp;
1104 	int bytelen, bitlen;
1105 
1106 	for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
1107 		if (plen != pp->prefixlen)
1108 			continue;
1109 		bytelen = plen / 8;
1110 		bitlen = plen % 8;
1111 		if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1112 			continue;
1113 		if (prefix->s6_addr[bytelen] >> (8 - bitlen) ==
1114 		    pp->prefix.s6_addr[bytelen] >> (8 - bitlen))
1115 			return(pp);
1116 	}
1117 
1118 	return(NULL);
1119 }
1120 
1121 static int
1122 nd6_options(struct nd_opt_hdr *hdr, int limit,
1123 	    union nd_opts *ndopts, u_int32_t optflags)
1124 {
1125 	int optlen = 0;
1126 
1127 	for (; limit > 0; limit -= optlen) {
1128 		hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1129 		optlen = hdr->nd_opt_len << 3;
1130 		if (hdr->nd_opt_len == 0) {
1131 			syslog(LOG_ERR,
1132 			       "<%s> bad ND option length(0) (type = %d)",
1133 			       __FUNCTION__, hdr->nd_opt_type);
1134 			goto bad;
1135 		}
1136 
1137 		if (hdr->nd_opt_type > ND_OPT_MTU) {
1138 			syslog(LOG_INFO,
1139 			       "<%s> unknown ND option(type %d)",
1140 			       __FUNCTION__,
1141 			       hdr->nd_opt_type);
1142 			continue;
1143 		}
1144 
1145 		if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1146 			syslog(LOG_INFO,
1147 			       "<%s> unexpected ND option(type %d)",
1148 			       __FUNCTION__,
1149 			       hdr->nd_opt_type);
1150 			continue;
1151 		}
1152 
1153 		switch(hdr->nd_opt_type) {
1154 		 case ND_OPT_SOURCE_LINKADDR:
1155 		 case ND_OPT_TARGET_LINKADDR:
1156 		 case ND_OPT_REDIRECTED_HEADER:
1157 		 case ND_OPT_MTU:
1158 			 if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1159 				 syslog(LOG_INFO,
1160 					"<%s> duplicated ND option"
1161 					" (type = %d)",
1162 					__FUNCTION__,
1163 					hdr->nd_opt_type);
1164 			 }
1165 			 ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1166 			 break;
1167 		 case ND_OPT_PREFIX_INFORMATION:
1168 		 {
1169 			 struct nd_optlist *pfxlist;
1170 
1171 			 if (ndopts->nd_opts_pi == 0) {
1172 				 ndopts->nd_opts_pi =
1173 					 (struct nd_opt_prefix_info *)hdr;
1174 				 continue;
1175 			 }
1176 			 if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1177 				 syslog(LOG_ERR,
1178 					"<%s> can't allocate memory",
1179 					__FUNCTION__);
1180 				 goto bad;
1181 			 }
1182 			 pfxlist->next = ndopts->nd_opts_list;
1183 			 pfxlist->opt = hdr;
1184 			 ndopts->nd_opts_list = pfxlist;
1185 
1186 			 break;
1187 		 }
1188 		 default:	/* impossible */
1189 			 break;
1190 		}
1191 	}
1192 
1193 	return(0);
1194 
1195   bad:
1196 	free_ndopts(ndopts);
1197 
1198 	return(-1);
1199 }
1200 
1201 static void
1202 free_ndopts(union nd_opts *ndopts)
1203 {
1204 	struct nd_optlist *opt = ndopts->nd_opts_list, *next;
1205 
1206 	while(opt) {
1207 		next = opt->next;
1208 		free(opt);
1209 		opt = next;
1210 	}
1211 }
1212 
1213 void
1214 sock_open()
1215 {
1216 	struct icmp6_filter filt;
1217 	struct ipv6_mreq mreq;
1218 	struct rainfo *ra = ralist;
1219 	int on;
1220 	/* XXX: should be max MTU attached to the node */
1221 	static u_char answer[1500];
1222 
1223 	rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1224 				CMSG_SPACE(sizeof(int));
1225 	rcvcmsgbuf = (u_char *)malloc(rcvcmsgbuflen);
1226 	if (rcvcmsgbuf == NULL) {
1227 		syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1228 		exit(1);
1229 	}
1230 
1231 	sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1232 				CMSG_SPACE(sizeof(int));
1233 	sndcmsgbuf = (u_char *)malloc(sndcmsgbuflen);
1234 	if (sndcmsgbuf == NULL) {
1235 		syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1236 		exit(1);
1237 	}
1238 
1239 	if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1240 		syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
1241 		       strerror(errno));
1242 		exit(1);
1243 	}
1244 
1245 	/* specify to tell receiving interface */
1246 	on = 1;
1247 #ifdef IPV6_RECVPKTINFO
1248 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1249 		       sizeof(on)) < 0) {
1250 		syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
1251 		       __FUNCTION__, strerror(errno));
1252 		exit(1);
1253 	}
1254 #else  /* old adv. API */
1255 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1256 		       sizeof(on)) < 0) {
1257 		syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
1258 		       __FUNCTION__, strerror(errno));
1259 		exit(1);
1260 	}
1261 #endif
1262 
1263 	on = 1;
1264 	/* specify to tell value of hoplimit field of received IP6 hdr */
1265 #ifdef IPV6_RECVHOPLIMIT
1266 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1267 		       sizeof(on)) < 0) {
1268 		syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
1269 		       __FUNCTION__, strerror(errno));
1270 		exit(1);
1271 	}
1272 #else  /* old adv. API */
1273 	if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1274 		       sizeof(on)) < 0) {
1275 		syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
1276 		       __FUNCTION__, strerror(errno));
1277 		exit(1);
1278 	}
1279 #endif
1280 
1281 	ICMP6_FILTER_SETBLOCKALL(&filt);
1282 	ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1283 	ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1284 	if (accept_rr)
1285 		ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1286 	if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1287 		       sizeof(filt)) < 0) {
1288 		syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1289 		       __FUNCTION__, strerror(errno));
1290 		exit(1);
1291 	}
1292 
1293 	/*
1294 	 * join all routers multicast address on each advertising interface.
1295 	 */
1296 	if (inet_pton(AF_INET6, ALLROUTERS, &mreq.ipv6mr_multiaddr.s6_addr)
1297 	    != 1) {
1298 		syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1299 		       __FUNCTION__);
1300 		exit(1);
1301 	}
1302 	while(ra) {
1303 		mreq.ipv6mr_interface = ra->ifindex;
1304 		if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1305 			       &mreq,
1306 			       sizeof(mreq)) < 0) {
1307 			syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP on %s: %s",
1308 			       __FUNCTION__, ra->ifname, strerror(errno));
1309 			exit(1);
1310 		}
1311 		ra = ra->next;
1312 	}
1313 
1314 	/* initialize msghdr for receiving packets */
1315 	rcviov[0].iov_base = (caddr_t)answer;
1316 	rcviov[0].iov_len = sizeof(answer);
1317 	rcvmhdr.msg_name = (caddr_t)&from;
1318 	rcvmhdr.msg_namelen = sizeof(from);
1319 	rcvmhdr.msg_iov = rcviov;
1320 	rcvmhdr.msg_iovlen = 1;
1321 	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1322 	rcvmhdr.msg_controllen = rcvcmsgbuflen;
1323 
1324 	/* initialize msghdr for sending packets */
1325 	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1326 	sndmhdr.msg_iov = sndiov;
1327 	sndmhdr.msg_iovlen = 1;
1328 	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1329 	sndmhdr.msg_controllen = sndcmsgbuflen;
1330 
1331 	return;
1332 }
1333 
1334 /* open a routing socket to watch the routing table */
1335 static void
1336 rtsock_open()
1337 {
1338 	if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1339 		syslog(LOG_ERR,
1340 		       "<%s> socket: %s", __FUNCTION__, strerror(errno));
1341 		exit(1);
1342 	}
1343 }
1344 
1345 static struct rainfo *
1346 if_indextorainfo(int index)
1347 {
1348 	struct rainfo *rai = ralist;
1349 
1350 	for (rai = ralist; rai; rai = rai->next) {
1351 		if (rai->ifindex == index)
1352 			return(rai);
1353 	}
1354 
1355 	return(NULL);		/* search failed */
1356 }
1357 
1358 static void
1359 ra_output(rainfo)
1360 struct rainfo *rainfo;
1361 {
1362 	int i;
1363 	struct cmsghdr *cm;
1364 	struct in6_pktinfo *pi;
1365 	struct soliciter *sol, *nextsol;
1366 
1367 	if ((iflist[rainfo->ifindex]->ifm_flags & IFF_UP) == 0) {
1368 		syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1369 		       __FUNCTION__, rainfo->ifname);
1370 		return;
1371 	}
1372 
1373 	sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
1374 	sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
1375 	sndmhdr.msg_iov[0].iov_len = rainfo->ra_datalen;
1376 
1377 	cm = CMSG_FIRSTHDR(&sndmhdr);
1378 	/* specify the outgoing interface */
1379 	cm->cmsg_level = IPPROTO_IPV6;
1380 	cm->cmsg_type = IPV6_PKTINFO;
1381 	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1382 	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1383 	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
1384 	pi->ipi6_ifindex = rainfo->ifindex;
1385 
1386 	/* specify the hop limit of the packet */
1387 	{
1388 		int hoplimit = 255;
1389 
1390 		cm = CMSG_NXTHDR(&sndmhdr, cm);
1391 		cm->cmsg_level = IPPROTO_IPV6;
1392 		cm->cmsg_type = IPV6_HOPLIMIT;
1393 		cm->cmsg_len = CMSG_LEN(sizeof(int));
1394 		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1395 	}
1396 
1397 	syslog(LOG_DEBUG,
1398 	       "<%s> send RA on %s, # of waitings = %d",
1399 	       __FUNCTION__, rainfo->ifname, rainfo->waiting);
1400 
1401 	i = sendmsg(sock, &sndmhdr, 0);
1402 
1403 	if (i < 0 || i != rainfo->ra_datalen)  {
1404 		if (i < 0) {
1405 			syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1406 			       __FUNCTION__, rainfo->ifname,
1407 			       strerror(errno));
1408 		}
1409 	}
1410 
1411 	/*
1412 	 * unicast advertisements
1413 	 * XXX commented out.  reason: though spec does not forbit it, unicast
1414 	 * advert does not really help
1415 	 */
1416 	for (sol = rainfo->soliciter; sol; sol = nextsol) {
1417 		nextsol = sol->next;
1418 
1419 #if 0
1420 		sndmhdr.msg_name = (caddr_t)&sol->addr;
1421 		i = sendmsg(sock, &sndmhdr, 0);
1422 		if (i < 0 || i != rainfo->ra_datalen)  {
1423 			if (i < 0) {
1424 				syslog(LOG_ERR,
1425 				    "<%s> unicast sendmsg on %s: %s",
1426 				    __FUNCTION__, rainfo->ifname,
1427 				    strerror(errno));
1428 			}
1429 		}
1430 #endif
1431 
1432 		sol->next = NULL;
1433 		free(sol);
1434 	}
1435 	rainfo->soliciter = NULL;
1436 
1437 	/* update counter */
1438 	if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1439 		rainfo->initcounter++;
1440 	rainfo->raoutput++;
1441 
1442 	/* update timestamp */
1443 	gettimeofday(&rainfo->lastsent, NULL);
1444 
1445 	/* reset waiting conter */
1446 	rainfo->waiting = 0;
1447 }
1448 
1449 /* process RA timer */
1450 void
1451 ra_timeout(void *data)
1452 {
1453 	struct rainfo *rai = (struct rainfo *)data;
1454 
1455 #ifdef notyet
1456 	/* if necessary, reconstruct the packet. */
1457 #endif
1458 
1459 	syslog(LOG_DEBUG,
1460 	       "<%s> RA timer on %s is expired",
1461 	       __FUNCTION__, rai->ifname);
1462 
1463 	ra_output(rai);
1464 }
1465 
1466 /* update RA timer */
1467 void
1468 ra_timer_update(void *data, struct timeval *tm)
1469 {
1470 	struct rainfo *rai = (struct rainfo *)data;
1471 	long interval;
1472 
1473 	/*
1474 	 * Whenever a multicast advertisement is sent from an interface,
1475 	 * the timer is reset to a uniformly-distributed random value
1476 	 * between the interface's configured MinRtrAdvInterval and
1477 	 * MaxRtrAdvInterval(discovery-v2-02 6.2.4).
1478 	 */
1479 	interval = rai->mininterval;
1480 	interval += random() % (rai->maxinterval - rai->mininterval);
1481 
1482 	/*
1483 	 * For the first few advertisements (up to
1484 	 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1485 	 * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1486 	 * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1487 	 * (RFC-2461 6.2.4)
1488 	 */
1489 	if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1490 	    interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1491 		interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1492 
1493 	tm->tv_sec = interval;
1494 	tm->tv_usec = 0;
1495 
1496 	syslog(LOG_DEBUG,
1497 	       "<%s> RA timer on %s is set to %ld:%ld",
1498 	       __FUNCTION__, rai->ifname,
1499 	       (long int)tm->tv_sec, (long int)tm->tv_usec);
1500 
1501 	return;
1502 }
1503