xref: /freebsd/usr.sbin/rtadvd/if.c (revision a0ca4af9455b844c5e094fc1b09b1390ffa979fc)
1 /*	$KAME: if.c,v 1.17 2001/01/21 15:27:30 itojun Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the project nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <sys/sysctl.h>
38 #include <sys/ioctl.h>
39 #include <net/if.h>
40 #include <net/if_dl.h>
41 #include <net/if_types.h>
42 #include <net/ethernet.h>
43 #include <net/route.h>
44 #include <netinet/in.h>
45 #include <netinet/in_var.h>
46 #include <netinet/ip6.h>
47 #include <netinet/icmp6.h>
48 #include <netinet6/nd6.h>
49 #include <unistd.h>
50 #include <errno.h>
51 #include <netdb.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <syslog.h>
55 
56 #include "pathnames.h"
57 #include "rtadvd.h"
58 #include "if.h"
59 
60 #define ROUNDUP(a, size)					\
61 	(((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a))
62 
63 #define	NEXT_SA(ap)							\
64 	(ap) = (struct sockaddr *)((caddr_t)(ap) +			\
65 	    ((ap)->sa_len ? ROUNDUP((ap)->sa_len, sizeof(u_long)) :	\
66 	    sizeof(u_long)))
67 
68 struct sockaddr_in6 sin6_linklocal_allnodes = {
69         .sin6_len =     sizeof(sin6_linklocal_allnodes),
70         .sin6_family =  AF_INET6,
71         .sin6_addr =    IN6ADDR_LINKLOCAL_ALLNODES_INIT,
72 };
73 
74 struct sockaddr_in6 sin6_linklocal_allrouters = {
75         .sin6_len =     sizeof(sin6_linklocal_allrouters),
76         .sin6_family =  AF_INET6,
77         .sin6_addr =    IN6ADDR_LINKLOCAL_ALLROUTERS_INIT,
78 };
79 
80 struct sockaddr_in6 sin6_sitelocal_allrouters = {
81         .sin6_len =     sizeof(sin6_sitelocal_allrouters),
82         .sin6_family =  AF_INET6,
83         .sin6_addr =    IN6ADDR_SITELOCAL_ALLROUTERS_INIT,
84 };
85 
86 struct sockinfo sock = { .si_fd = -1, .si_name = NULL };
87 struct sockinfo rtsock = { .si_fd = -1, .si_name = NULL };
88 struct sockinfo ctrlsock = { .si_fd = -1, .si_name = _PATH_CTRL_SOCK };
89 
90 char *mcastif;
91 
92 static void		get_rtaddrs(int, struct sockaddr *,
93 			    struct sockaddr **);
94 static struct if_msghdr	*get_next_msghdr(struct if_msghdr *,
95 			    struct if_msghdr *);
96 
97 static void
98 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
99 {
100 	int i;
101 
102 	for (i = 0; i < RTAX_MAX; i++) {
103 		if (addrs & (1 << i)) {
104 			rti_info[i] = sa;
105 			NEXT_SA(sa);
106 		}
107 		else
108 			rti_info[i] = NULL;
109 	}
110 }
111 
112 #define ROUNDUP8(a) (1 + (((a) - 1) | 7))
113 int
114 lladdropt_length(struct sockaddr_dl *sdl)
115 {
116 	switch (sdl->sdl_type) {
117 	case IFT_ETHER:
118 	case IFT_L2VLAN:
119 	case IFT_BRIDGE:
120 		return (ROUNDUP8(ETHER_ADDR_LEN + 2));
121 	default:
122 		return (0);
123 	}
124 }
125 
126 void
127 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt)
128 {
129 	char *addr;
130 
131 	ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */
132 
133 	switch (sdl->sdl_type) {
134 	case IFT_ETHER:
135 	case IFT_L2VLAN:
136 	case IFT_BRIDGE:
137 		ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3;
138 		addr = (char *)(ndopt + 1);
139 		memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN);
140 		break;
141 	default:
142 		syslog(LOG_ERR, "<%s> unsupported link type(%d)",
143 		    __func__, sdl->sdl_type);
144 		exit(1);
145 	}
146 }
147 
148 int
149 rtbuf_len(void)
150 {
151 	size_t len;
152 	int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0};
153 
154 	if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
155 		return (-1);
156 
157 	return (len);
158 }
159 
160 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter)
161 #define SIN6(s) ((struct sockaddr_in6 *)(s))
162 #define SDL(s) ((struct sockaddr_dl *)(s))
163 char *
164 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter)
165 {
166 	struct rt_msghdr *rtm;
167 	struct ifa_msghdr *ifam;
168 	struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX];
169 
170 	*lenp = 0;
171 	for (rtm = (struct rt_msghdr *)buf;
172 	     rtm < (struct rt_msghdr *)lim;
173 	     rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) {
174 		/* just for safety */
175 		if (!rtm->rtm_msglen) {
176 			syslog(LOG_WARNING, "<%s> rtm_msglen is 0 "
177 			    "(buf=%p lim=%p rtm=%p)", __func__,
178 			    buf, lim, rtm);
179 			break;
180 		}
181 		if (((struct rt_msghdr *)buf)->rtm_version != RTM_VERSION) {
182 			syslog(LOG_WARNING,
183 			    "<%s> routing message version mismatch "
184 			    "(buf=%p lim=%p rtm=%p)", __func__,
185 			    buf, lim, rtm);
186 			continue;
187 		}
188 
189 		if (FILTER_MATCH(rtm->rtm_type, filter) == 0)
190 			continue;
191 
192 		switch (rtm->rtm_type) {
193 		case RTM_GET:
194 		case RTM_ADD:
195 		case RTM_DELETE:
196 			/* address related checks */
197 			sa = (struct sockaddr *)(rtm + 1);
198 			get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
199 			if ((dst = rti_info[RTAX_DST]) == NULL ||
200 			    dst->sa_family != AF_INET6)
201 				continue;
202 
203 			if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) ||
204 			    IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr))
205 				continue;
206 
207 			if ((gw = rti_info[RTAX_GATEWAY]) == NULL ||
208 			    gw->sa_family != AF_LINK)
209 				continue;
210 			if (ifindex && SDL(gw)->sdl_index != ifindex)
211 				continue;
212 
213 			if (rti_info[RTAX_NETMASK] == NULL)
214 				continue;
215 
216 			/* found */
217 			*lenp = rtm->rtm_msglen;
218 			return (char *)rtm;
219 			/* NOTREACHED */
220 		case RTM_NEWADDR:
221 		case RTM_DELADDR:
222 			ifam = (struct ifa_msghdr *)rtm;
223 
224 			/* address related checks */
225 			sa = (struct sockaddr *)(ifam + 1);
226 			get_rtaddrs(ifam->ifam_addrs, sa, rti_info);
227 			if ((ifa = rti_info[RTAX_IFA]) == NULL ||
228 			    (ifa->sa_family != AF_INET &&
229 			     ifa->sa_family != AF_INET6))
230 				continue;
231 
232 			if (ifa->sa_family == AF_INET6 &&
233 			    (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) ||
234 			     IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr)))
235 				continue;
236 
237 			if (ifindex && ifam->ifam_index != ifindex)
238 				continue;
239 
240 			/* found */
241 			*lenp = ifam->ifam_msglen;
242 			return (char *)rtm;
243 			/* NOTREACHED */
244 		case RTM_IFINFO:
245 		case RTM_IFANNOUNCE:
246 			/* found */
247 			*lenp = rtm->rtm_msglen;
248 			return (char *)rtm;
249 			/* NOTREACHED */
250 		}
251 	}
252 
253 	return ((char *)rtm);
254 }
255 #undef FILTER_MATCH
256 
257 struct in6_addr *
258 get_addr(char *buf)
259 {
260 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
261 	struct sockaddr *sa, *rti_info[RTAX_MAX];
262 
263 	sa = (struct sockaddr *)(rtm + 1);
264 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
265 
266 	return (&SIN6(rti_info[RTAX_DST])->sin6_addr);
267 }
268 
269 int
270 get_rtm_ifindex(char *buf)
271 {
272 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
273 	struct sockaddr *sa, *rti_info[RTAX_MAX];
274 
275 	sa = (struct sockaddr *)(rtm + 1);
276 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
277 
278 	return (((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index);
279 }
280 
281 int
282 get_prefixlen(char *buf)
283 {
284 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
285 	struct sockaddr *sa, *rti_info[RTAX_MAX];
286 	char *p, *lim;
287 
288 	sa = (struct sockaddr *)(rtm + 1);
289 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
290 	sa = rti_info[RTAX_NETMASK];
291 
292 	p = (char *)(&SIN6(sa)->sin6_addr);
293 	lim = (char *)sa + sa->sa_len;
294 	return prefixlen(p, lim);
295 }
296 
297 int
298 prefixlen(unsigned char *p, unsigned char *lim)
299 {
300 	int masklen;
301 
302 	for (masklen = 0; p < lim; p++) {
303 		switch (*p) {
304 		case 0xff:
305 			masklen += 8;
306 			break;
307 		case 0xfe:
308 			masklen += 7;
309 			break;
310 		case 0xfc:
311 			masklen += 6;
312 			break;
313 		case 0xf8:
314 			masklen += 5;
315 			break;
316 		case 0xf0:
317 			masklen += 4;
318 			break;
319 		case 0xe0:
320 			masklen += 3;
321 			break;
322 		case 0xc0:
323 			masklen += 2;
324 			break;
325 		case 0x80:
326 			masklen += 1;
327 			break;
328 		case 0x00:
329 			break;
330 		default:
331 			return (-1);
332 		}
333 	}
334 
335 	return (masklen);
336 }
337 
338 struct ifinfo *
339 update_persist_ifinfo(struct ifilist_head_t *ifi_head, const char *ifname)
340 {
341 	struct ifinfo *ifi;
342 	int ifindex;
343 
344 	ifi = NULL;
345 	ifindex = if_nametoindex(ifname);
346 	TAILQ_FOREACH(ifi, ifi_head, ifi_next) {
347 		if (ifindex != 0) {
348 			if (ifindex == ifi->ifi_ifindex)
349 				break;
350 		} else {
351 			if (strncmp(ifname, ifi->ifi_ifname,
352 				sizeof(ifi->ifi_ifname)) == 0)
353 				break;
354 		}
355 	}
356 
357 	if (ifi == NULL) {
358 		/* A new ifinfo element is needed. */
359 		syslog(LOG_DEBUG, "<%s> new entry: %s", __func__,
360 		    ifname);
361 
362 		ELM_MALLOC(ifi, exit(1));
363 		ifi->ifi_ifindex = 0;
364 		strlcpy(ifi->ifi_ifname, ifname, sizeof(ifi->ifi_ifname));
365 		ifi->ifi_rainfo = NULL;
366 		ifi->ifi_state = IFI_STATE_UNCONFIGURED;
367 		TAILQ_INSERT_TAIL(ifi_head, ifi, ifi_next);
368 	}
369 
370 	ifi->ifi_persist = 1;
371 
372 	syslog(LOG_DEBUG, "<%s> %s is marked PERSIST", __func__,
373 	    ifi->ifi_ifname);
374 	syslog(LOG_DEBUG, "<%s> %s is state = %d", __func__,
375 	    ifi->ifi_ifname, ifi->ifi_state);
376 	return (ifi);
377 }
378 
379 int
380 update_ifinfo_nd_flags(struct ifinfo *ifi)
381 {
382 	struct in6_ndireq nd;
383 	int s;
384 	int error;
385 
386 	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
387 		syslog(LOG_ERR,
388 		    "<%s> socket() failed.", __func__);
389 		return (1);
390 	}
391 	/* ND flags */
392 	memset(&nd, 0, sizeof(nd));
393 	strlcpy(nd.ifname, ifi->ifi_ifname,
394 	    sizeof(nd.ifname));
395 	error = ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd);
396 	if (error) {
397 		close(s);
398 		if (errno != EPFNOSUPPORT)
399 			syslog(LOG_ERR, "<%s> ioctl() failed.", __func__);
400 		return (1);
401 	}
402 	ifi->ifi_nd_flags = nd.ndi.flags;
403 	close(s);
404 
405 	return (0);
406 }
407 
408 #define MAX_SYSCTL_TRY 5
409 
410 struct ifinfo *
411 update_ifinfo(struct ifilist_head_t *ifi_head, int ifindex)
412 {
413 	struct if_msghdr *ifm;
414 	struct ifinfo *ifi = NULL;
415 	struct sockaddr *sa;
416 	struct sockaddr *rti_info[RTAX_MAX];
417 	char *msg;
418 	size_t len;
419 	char *lim;
420 	int mib[] = { CTL_NET, PF_ROUTE, 0, AF_INET6, NET_RT_IFLIST, 0 };
421 	int error, ntry;
422 
423 	syslog(LOG_DEBUG, "<%s> enter", __func__);
424 
425 	ntry = 0;
426 	do {
427 		/*
428 		 * We'll try to get addresses several times in case that
429 		 * the number of addresses is unexpectedly increased during
430 		 * the two sysctl calls.  This should rarely happen.
431 		 * Portability note: since FreeBSD does not add margin of
432 		 * memory at the first sysctl, the possibility of failure on
433 		 * the second sysctl call is a bit higher.
434 		 */
435 
436 		if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) < 0) {
437 			syslog(LOG_ERR,
438 			    "<%s> sysctl: NET_RT_IFLIST size get failed",
439 			    __func__);
440 			exit(1);
441 		}
442 		if ((msg = malloc(len)) == NULL) {
443 			syslog(LOG_ERR, "<%s> malloc failed", __func__);
444 			exit(1);
445 		}
446 		if (sysctl(mib, nitems(mib), msg, &len, NULL, 0) < 0) {
447 			if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
448 				free(msg);
449 				syslog(LOG_ERR,
450 				    "<%s> sysctl: NET_RT_IFLIST get failed",
451 				    __func__);
452 				exit(1);
453 			}
454 			free(msg);
455 			msg = NULL;
456 		}
457 	} while (msg == NULL);
458 
459 	lim = msg + len;
460 	for (ifm = (struct if_msghdr *)msg;
461 	     ifm != NULL && ifm < (struct if_msghdr *)lim;
462 	     ifm = get_next_msghdr(ifm,(struct if_msghdr *)lim)) {
463 		int ifi_new;
464 
465 		syslog(LOG_DEBUG, "<%s> ifm = %p, lim = %p, diff = %zu",
466 		    __func__, ifm, lim, (char *)lim - (char *)ifm);
467 
468 		if (ifm->ifm_version != RTM_VERSION) {
469 			syslog(LOG_ERR,
470 			    "<%s> ifm_vesrion mismatch", __func__);
471 			exit(1);
472 		}
473 		if (ifm->ifm_msglen == 0) {
474 			syslog(LOG_WARNING,
475 			    "<%s> ifm_msglen is 0", __func__);
476 			free(msg);
477 			return (NULL);
478 		}
479 
480 		ifi_new = 0;
481 		if (ifm->ifm_type == RTM_IFINFO) {
482 			struct ifreq ifr;
483 			int s;
484 			char ifname[IFNAMSIZ];
485 
486 			syslog(LOG_DEBUG, "<%s> RTM_IFINFO found. "
487 			    "ifm_index = %d, ifindex = %d",
488 			    __func__, ifm->ifm_index, ifindex);
489 
490 			/* when ifindex is specified */
491 			if (ifindex != UPDATE_IFINFO_ALL &&
492 			    ifindex != ifm->ifm_index)
493 				continue;
494 
495 			/* ifname */
496 			if (if_indextoname(ifm->ifm_index, ifname) == NULL) {
497 				syslog(LOG_WARNING,
498 				    "<%s> ifname not found (idx=%d)",
499 				    __func__, ifm->ifm_index);
500 				continue;
501 			}
502 
503 			/* lookup an entry with the same ifindex */
504 			TAILQ_FOREACH(ifi, ifi_head, ifi_next) {
505 				if (ifm->ifm_index == ifi->ifi_ifindex)
506 					break;
507 				if (strncmp(ifname, ifi->ifi_ifname,
508 					sizeof(ifname)) == 0)
509 					break;
510 			}
511 			if (ifi == NULL) {
512 				syslog(LOG_DEBUG,
513 				    "<%s> new entry for idx=%d",
514 				    __func__, ifm->ifm_index);
515 				ELM_MALLOC(ifi, exit(1));
516 				ifi->ifi_rainfo = NULL;
517 				ifi->ifi_state = IFI_STATE_UNCONFIGURED;
518 				ifi->ifi_persist = 0;
519 				ifi_new = 1;
520 			}
521 			/* ifindex */
522 			ifi->ifi_ifindex = ifm->ifm_index;
523 
524 			/* ifname */
525 			strlcpy(ifi->ifi_ifname, ifname, IFNAMSIZ);
526 
527 			if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
528 				syslog(LOG_ERR,
529 				    "<%s> socket() failed.", __func__);
530 				if (ifi_new)
531 					free(ifi);
532 				continue;
533 			}
534 
535 			/* MTU  */
536 			ifi->ifi_phymtu = ifm->ifm_data.ifi_mtu;
537 			if (ifi->ifi_phymtu == 0) {
538 				memset(&ifr, 0, sizeof(ifr));
539 				ifr.ifr_addr.sa_family = AF_INET6;
540 				strlcpy(ifr.ifr_name, ifi->ifi_ifname,
541 				    sizeof(ifr.ifr_name));
542 				error = ioctl(s, SIOCGIFMTU, (caddr_t)&ifr);
543 				if (error) {
544 					close(s);
545 					syslog(LOG_ERR,
546 					    "<%s> ioctl() failed.",
547 					    __func__);
548 					if (ifi_new)
549 						free(ifi);
550 					continue;
551 				}
552 				ifi->ifi_phymtu = ifr.ifr_mtu;
553 				if (ifi->ifi_phymtu == 0) {
554 					syslog(LOG_WARNING,
555 					    "<%s> no interface mtu info"
556 					    " on %s.  %d will be used.",
557 					    __func__, ifi->ifi_ifname,
558 					    IPV6_MMTU);
559 					ifi->ifi_phymtu = IPV6_MMTU;
560 				}
561 			}
562 			close(s);
563 
564 			/* ND flags */
565 			error = update_ifinfo_nd_flags(ifi);
566 			if (error) {
567 				if (ifi_new)
568 					free(ifi);
569 				continue;
570 			}
571 
572 			/* SDL */
573 			sa = (struct sockaddr *)(ifm + 1);
574 			get_rtaddrs(ifm->ifm_addrs, sa, rti_info);
575 			if ((sa = rti_info[RTAX_IFP]) != NULL) {
576 				if (sa->sa_family == AF_LINK) {
577 					memcpy(&ifi->ifi_sdl,
578 					    (struct sockaddr_dl *)sa,
579 					    sizeof(ifi->ifi_sdl));
580 				}
581 			} else
582 				memset(&ifi->ifi_sdl, 0,
583 				    sizeof(ifi->ifi_sdl));
584 
585 			/* flags */
586 			ifi->ifi_flags = ifm->ifm_flags;
587 
588 			/* type */
589 			ifi->ifi_type = ifm->ifm_type;
590 		} else {
591 			syslog(LOG_ERR,
592 			    "out of sync parsing NET_RT_IFLIST\n"
593 			    "expected %d, got %d\n msglen = %d\n",
594 			    RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen);
595 			exit(1);
596 		}
597 
598 		if (ifi_new) {
599 			syslog(LOG_DEBUG,
600 			    "<%s> adding %s(idx=%d) to ifilist",
601 			    __func__, ifi->ifi_ifname, ifi->ifi_ifindex);
602 			TAILQ_INSERT_TAIL(ifi_head, ifi, ifi_next);
603 		}
604 	}
605 	free(msg);
606 
607 	if (mcastif != NULL) {
608 		error = sock_mc_rr_update(&sock, mcastif);
609 		if (error)
610 			exit(1);
611 	}
612 
613 	return (ifi);
614 }
615 
616 static struct if_msghdr *
617 get_next_msghdr(struct if_msghdr *ifm, struct if_msghdr *lim)
618 {
619 	struct ifa_msghdr *ifam;
620 
621 	for (ifam = (struct ifa_msghdr *)((char *)ifm + ifm->ifm_msglen);
622 	     ifam < (struct ifa_msghdr *)lim;
623 	     ifam = (struct ifa_msghdr *)((char *)ifam + ifam->ifam_msglen)) {
624 		if (!ifam->ifam_msglen) {
625 			syslog(LOG_WARNING,
626 			    "<%s> ifa_msglen is 0", __func__);
627 			return (NULL);
628 		}
629 		if (ifam->ifam_type != RTM_NEWADDR)
630 			break;
631 	}
632 
633 	return ((struct if_msghdr *)ifam);
634 }
635 
636 int
637 getinet6sysctl(int code)
638 {
639 	int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
640 	int value;
641 	size_t size;
642 
643 	mib[3] = code;
644 	size = sizeof(value);
645 	if (sysctl(mib, nitems(mib), &value, &size, NULL, 0)
646 	    < 0) {
647 		syslog(LOG_ERR, "<%s>: failed to get ip6 sysctl(%d): %s",
648 		    __func__, code,
649 		    strerror(errno));
650 		return (-1);
651 	}
652 	else
653 		return (value);
654 }
655 
656 
657 int
658 sock_mc_join(struct sockinfo *s, int ifindex)
659 {
660 	struct ipv6_mreq mreq;
661 	char ifname[IFNAMSIZ];
662 
663 	syslog(LOG_DEBUG, "<%s> enter", __func__);
664 
665 	if (ifindex == 0)
666 		return (1);
667 
668 	/*
669 	 * join all routers multicast address on each advertising
670 	 * interface.
671 	 */
672 	memset(&mreq, 0, sizeof(mreq));
673 	/* XXX */
674 	memcpy(&mreq.ipv6mr_multiaddr.s6_addr,
675 	    &sin6_linklocal_allrouters.sin6_addr,
676 	    sizeof(mreq.ipv6mr_multiaddr.s6_addr));
677 
678 	mreq.ipv6mr_interface = ifindex;
679 	if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
680 		sizeof(mreq)) < 0) {
681 		syslog(LOG_ERR,
682 		    "<%s> IPV6_JOIN_GROUP(link) on %s: %s",
683 		    __func__, if_indextoname(ifindex, ifname),
684 		    strerror(errno));
685 		return (1);
686 	}
687 	syslog(LOG_DEBUG,
688 	    "<%s> %s: join link-local all-routers MC group",
689 	    __func__, if_indextoname(ifindex, ifname));
690 
691 	return (0);
692 }
693 
694 int
695 sock_mc_leave(struct sockinfo *s, int ifindex)
696 {
697 	struct ipv6_mreq mreq;
698 	char ifname[IFNAMSIZ];
699 
700 	syslog(LOG_DEBUG, "<%s> enter", __func__);
701 
702 	if (ifindex == 0)
703 		return (1);
704 
705 	/*
706 	 * join all routers multicast address on each advertising
707 	 * interface.
708 	 */
709 
710 	memset(&mreq, 0, sizeof(mreq));
711 	/* XXX */
712 	memcpy(&mreq.ipv6mr_multiaddr.s6_addr,
713 	    &sin6_linklocal_allrouters.sin6_addr,
714 	    sizeof(mreq.ipv6mr_multiaddr.s6_addr));
715 
716 	mreq.ipv6mr_interface = ifindex;
717 	if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &mreq,
718 		sizeof(mreq)) < 0) {
719 		syslog(LOG_ERR,
720 		    "<%s> IPV6_JOIN_LEAVE(link) on %s: %s",
721 		    __func__, if_indextoname(ifindex, ifname),
722 		    strerror(errno));
723 		return (1);
724 	}
725 	syslog(LOG_DEBUG,
726 	    "<%s> %s: leave link-local all-routers MC group",
727 	    __func__, if_indextoname(ifindex, ifname));
728 
729 	return (0);
730 }
731 
732 int
733 sock_mc_rr_update(struct sockinfo *s, char *mif)
734 {
735 	struct ipv6_mreq mreq;
736 
737 	syslog(LOG_DEBUG, "<%s> enter", __func__);
738 
739 	if (mif == NULL)
740 		return (1);
741 	/*
742 	 * When attending router renumbering, join all-routers site-local
743 	 * multicast group.
744 	 */
745 	/* XXX */
746 	memcpy(&mreq.ipv6mr_multiaddr.s6_addr,
747 	    &sin6_sitelocal_allrouters.sin6_addr,
748 	    sizeof(mreq.ipv6mr_multiaddr.s6_addr));
749 	if ((mreq.ipv6mr_interface = if_nametoindex(mif)) == 0) {
750 		syslog(LOG_ERR,
751 		    "<%s> invalid interface: %s",
752 		    __func__, mif);
753 		return (1);
754 	}
755 
756 	if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_JOIN_GROUP,
757 		&mreq, sizeof(mreq)) < 0) {
758 		syslog(LOG_ERR,
759 		    "<%s> IPV6_JOIN_GROUP(site) on %s: %s",
760 		    __func__, mif, strerror(errno));
761 		return (1);
762 	}
763 
764 	syslog(LOG_DEBUG,
765 	    "<%s> %s: join site-local all-routers MC group",
766 	    __func__, mif);
767 
768 	return (0);
769 }
770