1 /* $FreeBSD$ */
2 /* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/param.h>
35 #include <sys/ioctl.h>
36 #include <sys/socket.h>
37 #include <sys/uio.h>
38 #include <sys/queue.h>
39 #include <sys/stat.h>
40 #include <sys/sysctl.h>
41
42 #include <net/if.h>
43 #include <net/if_types.h>
44 #include <net/if_media.h>
45 #include <net/if_dl.h>
46 #include <net/route.h>
47 #include <netinet/in.h>
48 #include <netinet/ip6.h>
49 #include <netinet6/ip6_var.h>
50 #include <netinet/icmp6.h>
51
52 #include <arpa/inet.h>
53
54 #include <netinet/in_var.h>
55 #include <netinet6/nd6.h>
56
57 #include <time.h>
58 #include <unistd.h>
59 #include <stdio.h>
60 #include <err.h>
61 #include <errno.h>
62 #include <inttypes.h>
63 #include <libutil.h>
64 #include <netdb.h>
65 #include <signal.h>
66 #include <string.h>
67 #include <stdlib.h>
68 #include <syslog.h>
69 #include <poll.h>
70
71 #include "pathnames.h"
72 #include "rtadvd.h"
73 #include "if.h"
74 #include "rrenum.h"
75 #include "advcap.h"
76 #include "timer_subr.h"
77 #include "timer.h"
78 #include "config.h"
79 #include "control.h"
80 #include "control_server.h"
81
82 #define RTADV_TYPE2BITMASK(type) (0x1 << type)
83
84 struct msghdr rcvmhdr;
85 static char *rcvcmsgbuf;
86 static size_t rcvcmsgbuflen;
87 static char *sndcmsgbuf = NULL;
88 static size_t sndcmsgbuflen;
89 struct msghdr sndmhdr;
90 struct iovec rcviov[2];
91 struct iovec sndiov[2];
92 struct sockaddr_in6 rcvfrom;
93 static const char *pidfilename = _PATH_RTADVDPID;
94 const char *conffile = _PATH_RTADVDCONF;
95 static struct pidfh *pfh;
96 static int dflag, sflag;
97 static int wait_shutdown;
98
99 #define PFD_RAWSOCK 0
100 #define PFD_RTSOCK 1
101 #define PFD_CSOCK 2
102 #define PFD_MAX 3
103
104 struct railist_head_t railist =
105 TAILQ_HEAD_INITIALIZER(railist);
106 struct ifilist_head_t ifilist =
107 TAILQ_HEAD_INITIALIZER(ifilist);
108
109 struct nd_optlist {
110 TAILQ_ENTRY(nd_optlist) nol_next;
111 struct nd_opt_hdr *nol_opt;
112 };
113 union nd_opt {
114 struct nd_opt_hdr *opt_array[9];
115 struct {
116 struct nd_opt_hdr *zero;
117 struct nd_opt_hdr *src_lladdr;
118 struct nd_opt_hdr *tgt_lladdr;
119 struct nd_opt_prefix_info *pi;
120 struct nd_opt_rd_hdr *rh;
121 struct nd_opt_mtu *mtu;
122 TAILQ_HEAD(, nd_optlist) opt_list;
123 } nd_opt_each;
124 };
125 #define opt_src_lladdr nd_opt_each.src_lladdr
126 #define opt_tgt_lladdr nd_opt_each.tgt_lladdr
127 #define opt_pi nd_opt_each.pi
128 #define opt_rh nd_opt_each.rh
129 #define opt_mtu nd_opt_each.mtu
130 #define opt_list nd_opt_each.opt_list
131
132 #define NDOPT_FLAG_SRCLINKADDR (1 << 0)
133 #define NDOPT_FLAG_TGTLINKADDR (1 << 1)
134 #define NDOPT_FLAG_PREFIXINFO (1 << 2)
135 #define NDOPT_FLAG_RDHDR (1 << 3)
136 #define NDOPT_FLAG_MTU (1 << 4)
137 #define NDOPT_FLAG_RDNSS (1 << 5)
138 #define NDOPT_FLAG_DNSSL (1 << 6)
139
140 static uint32_t ndopt_flags[] = {
141 [ND_OPT_SOURCE_LINKADDR] = NDOPT_FLAG_SRCLINKADDR,
142 [ND_OPT_TARGET_LINKADDR] = NDOPT_FLAG_TGTLINKADDR,
143 [ND_OPT_PREFIX_INFORMATION] = NDOPT_FLAG_PREFIXINFO,
144 [ND_OPT_REDIRECTED_HEADER] = NDOPT_FLAG_RDHDR,
145 [ND_OPT_MTU] = NDOPT_FLAG_MTU,
146 [ND_OPT_RDNSS] = NDOPT_FLAG_RDNSS,
147 [ND_OPT_DNSSL] = NDOPT_FLAG_DNSSL,
148 };
149
150 static void rtadvd_shutdown(void);
151 static void sock_open(struct sockinfo *);
152 static void rtsock_open(struct sockinfo *);
153 static void rtadvd_input(struct sockinfo *);
154 static void rs_input(int, struct nd_router_solicit *,
155 struct in6_pktinfo *, struct sockaddr_in6 *);
156 static void ra_input(int, struct nd_router_advert *,
157 struct in6_pktinfo *, struct sockaddr_in6 *);
158 static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
159 struct sockaddr_in6 *);
160 static int nd6_options(struct nd_opt_hdr *, int,
161 union nd_opt *, uint32_t);
162 static void free_ndopts(union nd_opt *);
163 static void rtmsg_input(struct sockinfo *);
164 static void set_short_delay(struct ifinfo *);
165 static int check_accept_rtadv(int);
166
167 static void
usage(void)168 usage(void)
169 {
170
171 fprintf(stderr, "usage: rtadvd [-dDfRs] "
172 "[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n");
173 exit(1);
174 }
175
176 int
main(int argc,char * argv[])177 main(int argc, char *argv[])
178 {
179 struct pollfd set[PFD_MAX];
180 struct timespec *timeout;
181 int i, ch;
182 int fflag = 0, logopt;
183 int error;
184 pid_t pid, otherpid;
185
186 /* get command line options and arguments */
187 while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) {
188 switch (ch) {
189 case 'c':
190 conffile = optarg;
191 break;
192 case 'C':
193 ctrlsock.si_name = optarg;
194 break;
195 case 'd':
196 dflag++;
197 break;
198 case 'D':
199 dflag += 3;
200 break;
201 case 'f':
202 fflag = 1;
203 break;
204 case 'M':
205 mcastif = optarg;
206 break;
207 case 'R':
208 fprintf(stderr, "rtadvd: "
209 "the -R option is currently ignored.\n");
210 /* accept_rr = 1; */
211 /* run anyway... */
212 break;
213 case 's':
214 sflag = 1;
215 break;
216 case 'p':
217 pidfilename = optarg;
218 break;
219 default:
220 usage();
221 }
222 }
223 argc -= optind;
224 argv += optind;
225
226 logopt = LOG_NDELAY | LOG_PID;
227 if (fflag)
228 logopt |= LOG_PERROR;
229 openlog("rtadvd", logopt, LOG_DAEMON);
230
231 /* set log level */
232 if (dflag > 2)
233 (void)setlogmask(LOG_UPTO(LOG_DEBUG));
234 else if (dflag > 1)
235 (void)setlogmask(LOG_UPTO(LOG_INFO));
236 else if (dflag > 0)
237 (void)setlogmask(LOG_UPTO(LOG_NOTICE));
238 else
239 (void)setlogmask(LOG_UPTO(LOG_ERR));
240
241 /* timer initialization */
242 rtadvd_timer_init();
243
244 pfh = pidfile_open(pidfilename, 0600, &otherpid);
245 if (pfh == NULL) {
246 if (errno == EEXIST)
247 errx(1, "%s already running, pid: %d",
248 getprogname(), otherpid);
249 syslog(LOG_ERR,
250 "failed to open the pid file %s, run anyway.",
251 pidfilename);
252 }
253 if (!fflag)
254 daemon(1, 0);
255
256 sock_open(&sock);
257
258 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
259 for (i = 0; i < argc; i++)
260 update_persist_ifinfo(&ifilist, argv[i]);
261
262 csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
263 if (ctrlsock.si_fd == -1) {
264 syslog(LOG_ERR, "cannot open control socket: %s",
265 strerror(errno));
266 exit(1);
267 }
268
269 /* record the current PID */
270 pid = getpid();
271 pidfile_write(pfh);
272
273 set[PFD_RAWSOCK].fd = sock.si_fd;
274 set[PFD_RAWSOCK].events = POLLIN;
275 if (sflag == 0) {
276 rtsock_open(&rtsock);
277 set[PFD_RTSOCK].fd = rtsock.si_fd;
278 set[PFD_RTSOCK].events = POLLIN;
279 } else
280 set[PFD_RTSOCK].fd = -1;
281 set[PFD_CSOCK].fd = ctrlsock.si_fd;
282 set[PFD_CSOCK].events = POLLIN;
283 signal(SIGTERM, set_do_shutdown);
284 signal(SIGINT, set_do_shutdown);
285 signal(SIGHUP, set_do_reload);
286
287 error = csock_listen(&ctrlsock);
288 if (error) {
289 syslog(LOG_ERR, "cannot listen control socket: %s",
290 strerror(errno));
291 exit(1);
292 }
293
294 /* load configuration file */
295 set_do_reload(0);
296
297 while (1) {
298 if (is_do_shutdown())
299 rtadvd_shutdown();
300
301 if (is_do_reload()) {
302 loadconfig_ifname(reload_ifname());
303 if (reload_ifname() == NULL)
304 syslog(LOG_INFO,
305 "configuration file reloaded.");
306 else
307 syslog(LOG_INFO,
308 "configuration file for %s reloaded.",
309 reload_ifname());
310 reset_do_reload();
311 }
312
313 /* timeout handler update for active interfaces */
314 rtadvd_update_timeout_handler();
315
316 /* timer expiration check and reset the timer */
317 timeout = rtadvd_check_timer();
318
319 if (timeout != NULL) {
320 syslog(LOG_DEBUG,
321 "<%s> set timer to %ld:%ld. waiting for "
322 "inputs or timeout", __func__,
323 (long int)timeout->tv_sec,
324 (long int)timeout->tv_nsec / 1000);
325 } else {
326 syslog(LOG_DEBUG,
327 "<%s> there's no timer. waiting for inputs",
328 __func__);
329 }
330 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
331 timeout ? (timeout->tv_sec * 1000 +
332 timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
333
334 /* EINTR would occur if a signal was delivered */
335 if (errno != EINTR)
336 syslog(LOG_ERR, "poll() failed: %s",
337 strerror(errno));
338 continue;
339 }
340 if (i == 0) /* timeout */
341 continue;
342 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
343 rtmsg_input(&rtsock);
344
345 if (set[PFD_RAWSOCK].revents & POLLIN)
346 rtadvd_input(&sock);
347
348 if (set[PFD_CSOCK].revents & POLLIN) {
349 int fd;
350
351 fd = csock_accept(&ctrlsock);
352 if (fd == -1)
353 syslog(LOG_ERR,
354 "cannot accept() control socket: %s",
355 strerror(errno));
356 else {
357 cm_handler_server(fd);
358 close(fd);
359 }
360 }
361 }
362 exit(0); /* NOTREACHED */
363 }
364
365 static void
rtadvd_shutdown(void)366 rtadvd_shutdown(void)
367 {
368 struct ifinfo *ifi;
369 struct rainfo *rai;
370 struct rdnss *rdn;
371 struct dnssl *dns;
372
373 if (wait_shutdown) {
374 syslog(LOG_INFO,
375 "waiting expiration of the all RA timers.");
376
377 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
378 /*
379 * Ignore !IFF_UP interfaces in waiting for shutdown.
380 */
381 if (!(ifi->ifi_flags & IFF_UP) &&
382 ifi->ifi_ra_timer != NULL) {
383 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
384 rtadvd_remove_timer(ifi->ifi_ra_timer);
385 ifi->ifi_ra_timer = NULL;
386 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
387 "Timer removed and marked as UNCONFIGURED.",
388 __func__, ifi->ifi_ifname,
389 ifi->ifi_ifindex);
390 }
391 }
392 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
393 if (ifi->ifi_ra_timer != NULL)
394 break;
395 }
396 if (ifi == NULL) {
397 syslog(LOG_NOTICE, "gracefully terminated.");
398 exit(0);
399 }
400
401 sleep(1);
402 return;
403 }
404
405 syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
406 __func__);
407
408 wait_shutdown = 1;
409
410 TAILQ_FOREACH(rai, &railist, rai_next) {
411 rai->rai_lifetime = 0;
412 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
413 rdn->rd_ltime = 0;
414 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
415 dns->dn_ltime = 0;
416 }
417 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
418 if (!ifi->ifi_persist)
419 continue;
420 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
421 continue;
422 if (ifi->ifi_ra_timer == NULL)
423 continue;
424 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
425 ifi->ifi_ra_lastsent.tv_nsec == 0 &&
426 ifi->ifi_ra_timer != NULL) {
427 /*
428 * When RA configured but never sent,
429 * ignore the IF immediately.
430 */
431 rtadvd_remove_timer(ifi->ifi_ra_timer);
432 ifi->ifi_ra_timer = NULL;
433 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
434 continue;
435 }
436
437 ifi->ifi_state = IFI_STATE_TRANSITIVE;
438
439 /* Mark as the shut-down state. */
440 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
441 ifi->ifi_rainfo = NULL;
442
443 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
444 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
445
446 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
447 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
448 ifi->ifi_ra_timer);
449 }
450 syslog(LOG_NOTICE, "final RA transmission started.");
451
452 pidfile_remove(pfh);
453 csock_close(&ctrlsock);
454 }
455
456 static void
rtmsg_input(struct sockinfo * s)457 rtmsg_input(struct sockinfo *s)
458 {
459 int n, type, ifindex = 0, plen;
460 size_t len;
461 char msg[2048], *next, *lim;
462 char ifname[IFNAMSIZ];
463 struct if_announcemsghdr *ifan;
464 struct rt_msghdr *rtm;
465 struct prefix *pfx;
466 struct rainfo *rai;
467 struct in6_addr *addr;
468 struct ifinfo *ifi;
469 char addrbuf[INET6_ADDRSTRLEN];
470 int prefixchange = 0;
471
472 if (s == NULL) {
473 syslog(LOG_ERR, "<%s> internal error", __func__);
474 exit(1);
475 }
476 n = read(s->si_fd, msg, sizeof(msg));
477 rtm = (struct rt_msghdr *)msg;
478 syslog(LOG_DEBUG, "<%s> received a routing message "
479 "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
480
481 if (n > rtm->rtm_msglen) {
482 /*
483 * This usually won't happen for messages received on
484 * a routing socket.
485 */
486 syslog(LOG_DEBUG,
487 "<%s> received data length is larger than "
488 "1st routing message len. multiple messages? "
489 "read %d bytes, but 1st msg len = %d",
490 __func__, n, rtm->rtm_msglen);
491 #if 0
492 /* adjust length */
493 n = rtm->rtm_msglen;
494 #endif
495 }
496
497 lim = msg + n;
498 for (next = msg; next < lim; next += len) {
499 int oldifflags;
500
501 next = get_next_msg(next, lim, 0, &len,
502 RTADV_TYPE2BITMASK(RTM_ADD) |
503 RTADV_TYPE2BITMASK(RTM_DELETE) |
504 RTADV_TYPE2BITMASK(RTM_NEWADDR) |
505 RTADV_TYPE2BITMASK(RTM_DELADDR) |
506 RTADV_TYPE2BITMASK(RTM_IFINFO) |
507 RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
508 if (len == 0)
509 break;
510 type = ((struct rt_msghdr *)next)->rtm_type;
511 switch (type) {
512 case RTM_ADD:
513 case RTM_DELETE:
514 ifindex = get_rtm_ifindex(next);
515 break;
516 case RTM_NEWADDR:
517 case RTM_DELADDR:
518 ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
519 break;
520 case RTM_IFINFO:
521 ifindex = (int)((struct if_msghdr *)next)->ifm_index;
522 break;
523 case RTM_IFANNOUNCE:
524 ifan = (struct if_announcemsghdr *)next;
525 switch (ifan->ifan_what) {
526 case IFAN_ARRIVAL:
527 case IFAN_DEPARTURE:
528 break;
529 default:
530 syslog(LOG_DEBUG,
531 "<%s:%d> unknown ifan msg (ifan_what=%d)",
532 __func__, __LINE__, ifan->ifan_what);
533 continue;
534 }
535
536 syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
537 __func__, ifan->ifan_index, ifan->ifan_what);
538 switch (ifan->ifan_what) {
539 case IFAN_ARRIVAL:
540 syslog(LOG_NOTICE,
541 "interface added (idx=%d)",
542 ifan->ifan_index);
543 update_ifinfo(&ifilist, ifan->ifan_index);
544 loadconfig_index(ifan->ifan_index);
545 break;
546 case IFAN_DEPARTURE:
547 syslog(LOG_NOTICE,
548 "interface removed (idx=%d)",
549 ifan->ifan_index);
550 rm_ifinfo_index(ifan->ifan_index);
551
552 /* Clear ifi_ifindex */
553 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
554 if (ifi->ifi_ifindex
555 == ifan->ifan_index) {
556 ifi->ifi_ifindex = 0;
557 break;
558 }
559 }
560 update_ifinfo(&ifilist, ifan->ifan_index);
561 break;
562 }
563 continue;
564 default:
565 /* should not reach here */
566 syslog(LOG_DEBUG,
567 "<%s:%d> unknown rtmsg %d on %s",
568 __func__, __LINE__, type,
569 if_indextoname(ifindex, ifname));
570 continue;
571 }
572 ifi = if_indextoifinfo(ifindex);
573 if (ifi == NULL) {
574 syslog(LOG_DEBUG,
575 "<%s> ifinfo not found for idx=%d. Why?",
576 __func__, ifindex);
577 continue;
578 }
579 rai = ifi->ifi_rainfo;
580 if (rai == NULL) {
581 syslog(LOG_DEBUG,
582 "<%s> route changed on "
583 "non advertising interface(%s)",
584 __func__, ifi->ifi_ifname);
585 continue;
586 }
587
588 oldifflags = ifi->ifi_flags;
589 /* init ifflags because it may have changed */
590 update_ifinfo(&ifilist, ifindex);
591
592 switch (type) {
593 case RTM_ADD:
594 if (sflag)
595 break; /* we aren't interested in prefixes */
596
597 addr = get_addr(msg);
598 plen = get_prefixlen(msg);
599 /* sanity check for plen */
600 /* as RFC2373, prefixlen is at least 4 */
601 if (plen < 4 || plen > 127) {
602 syslog(LOG_INFO, "<%s> new interface route's"
603 "plen %d is invalid for a prefix",
604 __func__, plen);
605 break;
606 }
607 pfx = find_prefix(rai, addr, plen);
608 if (pfx) {
609 if (pfx->pfx_timer) {
610 /*
611 * If the prefix has been invalidated,
612 * make it available again.
613 */
614 update_prefix(pfx);
615 prefixchange = 1;
616 } else
617 syslog(LOG_DEBUG,
618 "<%s> new prefix(%s/%d) "
619 "added on %s, "
620 "but it was already in list",
621 __func__,
622 inet_ntop(AF_INET6, addr,
623 (char *)addrbuf,
624 sizeof(addrbuf)),
625 plen, ifi->ifi_ifname);
626 break;
627 }
628 make_prefix(rai, ifindex, addr, plen);
629 prefixchange = 1;
630 break;
631 case RTM_DELETE:
632 if (sflag)
633 break;
634
635 addr = get_addr(msg);
636 plen = get_prefixlen(msg);
637 /* sanity check for plen */
638 /* as RFC2373, prefixlen is at least 4 */
639 if (plen < 4 || plen > 127) {
640 syslog(LOG_INFO,
641 "<%s> deleted interface route's "
642 "plen %d is invalid for a prefix",
643 __func__, plen);
644 break;
645 }
646 pfx = find_prefix(rai, addr, plen);
647 if (pfx == NULL) {
648 syslog(LOG_DEBUG,
649 "<%s> prefix(%s/%d) was deleted on %s, "
650 "but it was not in list",
651 __func__, inet_ntop(AF_INET6, addr,
652 (char *)addrbuf, sizeof(addrbuf)),
653 plen, ifi->ifi_ifname);
654 break;
655 }
656 invalidate_prefix(pfx);
657 prefixchange = 1;
658 break;
659 case RTM_NEWADDR:
660 case RTM_DELADDR:
661 case RTM_IFINFO:
662 break;
663 default:
664 /* should not reach here */
665 syslog(LOG_DEBUG,
666 "<%s:%d> unknown rtmsg %d on %s",
667 __func__, __LINE__, type,
668 if_indextoname(ifindex, ifname));
669 return;
670 }
671
672 /* check if an interface flag is changed */
673 if ((oldifflags & IFF_UP) && /* UP to DOWN */
674 !(ifi->ifi_flags & IFF_UP)) {
675 syslog(LOG_NOTICE,
676 "<interface %s becomes down. stop timer.",
677 ifi->ifi_ifname);
678 rtadvd_remove_timer(ifi->ifi_ra_timer);
679 ifi->ifi_ra_timer = NULL;
680 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
681 (ifi->ifi_flags & IFF_UP)) {
682 syslog(LOG_NOTICE,
683 "interface %s becomes up. restart timer.",
684 ifi->ifi_ifname);
685
686 ifi->ifi_state = IFI_STATE_TRANSITIVE;
687 ifi->ifi_burstcount =
688 MAX_INITIAL_RTR_ADVERTISEMENTS;
689 ifi->ifi_burstinterval =
690 MAX_INITIAL_RTR_ADVERT_INTERVAL;
691
692 ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
693 ra_timer_update, ifi, ifi);
694 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
695 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
696 ifi->ifi_ra_timer);
697 } else if (prefixchange &&
698 (ifi->ifi_flags & IFF_UP)) {
699 /*
700 * An advertised prefix has been added or invalidated.
701 * Will notice the change in a short delay.
702 */
703 set_short_delay(ifi);
704 }
705 }
706
707 return;
708 }
709
710 void
rtadvd_input(struct sockinfo * s)711 rtadvd_input(struct sockinfo *s)
712 {
713 ssize_t i;
714 int *hlimp = NULL;
715 #ifdef OLDRAWSOCKET
716 struct ip6_hdr *ip;
717 #endif
718 struct icmp6_hdr *icp;
719 int ifindex = 0;
720 struct cmsghdr *cm;
721 struct in6_pktinfo *pi = NULL;
722 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
723 struct in6_addr dst = in6addr_any;
724 struct ifinfo *ifi;
725
726 syslog(LOG_DEBUG, "<%s> enter", __func__);
727
728 if (s == NULL) {
729 syslog(LOG_ERR, "<%s> internal error", __func__);
730 exit(1);
731 }
732 /*
733 * Get message. We reset msg_controllen since the field could
734 * be modified if we had received a message before setting
735 * receive options.
736 */
737 rcvmhdr.msg_controllen = rcvcmsgbuflen;
738 if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
739 return;
740
741 /* extract optional information via Advanced API */
742 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
743 cm;
744 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
745 if (cm->cmsg_level == IPPROTO_IPV6 &&
746 cm->cmsg_type == IPV6_PKTINFO &&
747 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
748 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
749 ifindex = pi->ipi6_ifindex;
750 dst = pi->ipi6_addr;
751 }
752 if (cm->cmsg_level == IPPROTO_IPV6 &&
753 cm->cmsg_type == IPV6_HOPLIMIT &&
754 cm->cmsg_len == CMSG_LEN(sizeof(int)))
755 hlimp = (int *)CMSG_DATA(cm);
756 }
757 if (ifindex == 0) {
758 syslog(LOG_ERR, "failed to get receiving interface");
759 return;
760 }
761 if (hlimp == NULL) {
762 syslog(LOG_ERR, "failed to get receiving hop limit");
763 return;
764 }
765
766 /*
767 * If we happen to receive data on an interface which is now gone
768 * or down, just discard the data.
769 */
770 ifi = if_indextoifinfo(pi->ipi6_ifindex);
771 if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
772 syslog(LOG_INFO,
773 "<%s> received data on a disabled interface (%s)",
774 __func__,
775 (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
776 return;
777 }
778
779 #ifdef OLDRAWSOCKET
780 if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
781 syslog(LOG_ERR,
782 "packet size(%d) is too short", i);
783 return;
784 }
785
786 ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
787 icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
788 #else
789 if ((size_t)i < sizeof(struct icmp6_hdr)) {
790 syslog(LOG_ERR, "packet size(%zd) is too short", i);
791 return;
792 }
793
794 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
795 #endif
796
797 switch (icp->icmp6_type) {
798 case ND_ROUTER_SOLICIT:
799 /*
800 * Message verification - RFC 4861 6.1.1
801 * XXX: these checks must be done in the kernel as well,
802 * but we can't completely rely on them.
803 */
804 if (*hlimp != 255) {
805 syslog(LOG_NOTICE,
806 "RS with invalid hop limit(%d) "
807 "received from %s on %s",
808 *hlimp,
809 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
810 sizeof(ntopbuf)),
811 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
812 return;
813 }
814 if (icp->icmp6_code) {
815 syslog(LOG_NOTICE,
816 "RS with invalid ICMP6 code(%d) "
817 "received from %s on %s",
818 icp->icmp6_code,
819 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
820 sizeof(ntopbuf)),
821 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
822 return;
823 }
824 if ((size_t)i < sizeof(struct nd_router_solicit)) {
825 syslog(LOG_NOTICE,
826 "RS from %s on %s does not have enough "
827 "length (len = %zd)",
828 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
829 sizeof(ntopbuf)),
830 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
831 return;
832 }
833 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
834 break;
835 case ND_ROUTER_ADVERT:
836 /*
837 * Message verification - RFC 4861 6.1.2
838 * XXX: there's the same dilemma as above...
839 */
840 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
841 syslog(LOG_NOTICE,
842 "RA with non-linklocal source address "
843 "received from %s on %s",
844 inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
845 ntopbuf, sizeof(ntopbuf)),
846 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
847 return;
848 }
849 if (*hlimp != 255) {
850 syslog(LOG_NOTICE,
851 "RA with invalid hop limit(%d) "
852 "received from %s on %s",
853 *hlimp,
854 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
855 sizeof(ntopbuf)),
856 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
857 return;
858 }
859 if (icp->icmp6_code) {
860 syslog(LOG_NOTICE,
861 "RA with invalid ICMP6 code(%d) "
862 "received from %s on %s",
863 icp->icmp6_code,
864 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
865 sizeof(ntopbuf)),
866 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
867 return;
868 }
869 if ((size_t)i < sizeof(struct nd_router_advert)) {
870 syslog(LOG_NOTICE,
871 "RA from %s on %s does not have enough "
872 "length (len = %zd)",
873 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
874 sizeof(ntopbuf)),
875 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
876 return;
877 }
878 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
879 break;
880 case ICMP6_ROUTER_RENUMBERING:
881 if (mcastif == NULL) {
882 syslog(LOG_ERR, "received a router renumbering "
883 "message, but not allowed to be accepted");
884 break;
885 }
886 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
887 &dst);
888 break;
889 default:
890 /*
891 * Note that this case is POSSIBLE, especially just
892 * after invocation of the daemon. This is because we
893 * could receive message after opening the socket and
894 * before setting ICMP6 type filter(see sock_open()).
895 */
896 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
897 return;
898 }
899
900 return;
901 }
902
903 static void
rs_input(int len,struct nd_router_solicit * rs,struct in6_pktinfo * pi,struct sockaddr_in6 * from)904 rs_input(int len, struct nd_router_solicit *rs,
905 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
906 {
907 char ntopbuf[INET6_ADDRSTRLEN];
908 char ifnamebuf[IFNAMSIZ];
909 union nd_opt ndopts;
910 struct rainfo *rai;
911 struct ifinfo *ifi;
912 struct soliciter *sol;
913
914 syslog(LOG_DEBUG,
915 "<%s> RS received from %s on %s",
916 __func__,
917 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
918 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
919
920 /* ND option check */
921 memset(&ndopts, 0, sizeof(ndopts));
922 TAILQ_INIT(&ndopts.opt_list);
923 if (nd6_options((struct nd_opt_hdr *)(rs + 1),
924 len - sizeof(struct nd_router_solicit),
925 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
926 syslog(LOG_INFO,
927 "<%s> ND option check failed for an RS from %s on %s",
928 __func__,
929 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
930 sizeof(ntopbuf)),
931 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
932 return;
933 }
934
935 /*
936 * If the IP source address is the unspecified address, there
937 * must be no source link-layer address option in the message.
938 * (RFC 4861 6.1.1)
939 */
940 if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
941 ndopts.opt_src_lladdr) {
942 syslog(LOG_INFO,
943 "<%s> RS from unspecified src on %s has a link-layer"
944 " address option",
945 __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
946 goto done;
947 }
948
949 ifi = if_indextoifinfo(pi->ipi6_ifindex);
950 if (ifi == NULL) {
951 syslog(LOG_INFO,
952 "<%s> if (idx=%d) not found. Why?",
953 __func__, pi->ipi6_ifindex);
954 goto done;
955 }
956 rai = ifi->ifi_rainfo;
957 if (rai == NULL) {
958 syslog(LOG_INFO,
959 "<%s> RS received on non advertising interface(%s)",
960 __func__,
961 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
962 goto done;
963 }
964
965 rai->rai_ifinfo->ifi_rsinput++;
966
967 /*
968 * Decide whether to send RA according to the rate-limit
969 * consideration.
970 */
971
972 /* record sockaddr waiting for RA, if possible */
973 sol = (struct soliciter *)malloc(sizeof(*sol));
974 if (sol) {
975 sol->sol_addr = *from;
976 /* XXX RFC 2553 need clarification on flowinfo */
977 sol->sol_addr.sin6_flowinfo = 0;
978 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
979 }
980
981 /*
982 * If there is already a waiting RS packet, don't
983 * update the timer.
984 */
985 if (ifi->ifi_rs_waitcount++)
986 goto done;
987
988 set_short_delay(ifi);
989
990 done:
991 free_ndopts(&ndopts);
992 return;
993 }
994
995 static void
set_short_delay(struct ifinfo * ifi)996 set_short_delay(struct ifinfo *ifi)
997 {
998 long delay; /* must not be greater than 1000000 */
999 struct timespec interval, now, min_delay, tm_tmp, *rest;
1000
1001 if (ifi->ifi_ra_timer == NULL)
1002 return;
1003 /*
1004 * Compute a random delay. If the computed value
1005 * corresponds to a time later than the time the next
1006 * multicast RA is scheduled to be sent, ignore the random
1007 * delay and send the advertisement at the
1008 * already-scheduled time. RFC 4861 6.2.6
1009 */
1010 delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1011 interval.tv_sec = 0;
1012 interval.tv_nsec = delay * 1000;
1013 rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1014 if (TS_CMP(rest, &interval, <)) {
1015 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1016 "the rest of the current timer", __func__);
1017 interval = *rest;
1018 }
1019
1020 /*
1021 * If we sent a multicast Router Advertisement within
1022 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1023 * the advertisement to be sent at a time corresponding to
1024 * MIN_DELAY_BETWEEN_RAS plus the random value after the
1025 * previous advertisement was sent.
1026 */
1027 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1028 TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1029 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1030 min_delay.tv_nsec = 0;
1031 if (TS_CMP(&tm_tmp, &min_delay, <)) {
1032 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1033 TS_ADD(&min_delay, &interval, &interval);
1034 }
1035 rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1036 }
1037
1038 static int
check_accept_rtadv(int idx)1039 check_accept_rtadv(int idx)
1040 {
1041 struct ifinfo *ifi;
1042
1043 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1044 if (ifi->ifi_ifindex == idx)
1045 break;
1046 }
1047 if (ifi == NULL) {
1048 syslog(LOG_DEBUG,
1049 "<%s> if (idx=%d) not found. Why?",
1050 __func__, idx);
1051 return (0);
1052 }
1053 #if (__FreeBSD_version < 900000)
1054 /*
1055 * RA_RECV: !ip6.forwarding && ip6.accept_rtadv
1056 * RA_SEND: ip6.forwarding
1057 */
1058 return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
1059 (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
1060 #else
1061 /*
1062 * RA_RECV: ND6_IFF_ACCEPT_RTADV
1063 * RA_SEND: ip6.forwarding
1064 */
1065 if (update_ifinfo_nd_flags(ifi) != 0) {
1066 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1067 return (0);
1068 }
1069
1070 return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1071 #endif
1072 }
1073
1074 static void
ra_input(int len,struct nd_router_advert * nra,struct in6_pktinfo * pi,struct sockaddr_in6 * from)1075 ra_input(int len, struct nd_router_advert *nra,
1076 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1077 {
1078 struct rainfo *rai;
1079 struct ifinfo *ifi;
1080 char ntopbuf[INET6_ADDRSTRLEN];
1081 char ifnamebuf[IFNAMSIZ];
1082 union nd_opt ndopts;
1083 const char *on_off[] = {"OFF", "ON"};
1084 uint32_t reachabletime, retranstimer, mtu;
1085 int inconsistent = 0;
1086 int error;
1087
1088 syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1089 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1090 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1091
1092 /* ND option check */
1093 memset(&ndopts, 0, sizeof(ndopts));
1094 TAILQ_INIT(&ndopts.opt_list);
1095 error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1096 len - sizeof(struct nd_router_advert), &ndopts,
1097 NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1098 NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1099 if (error) {
1100 syslog(LOG_INFO,
1101 "<%s> ND option check failed for an RA from %s on %s",
1102 __func__,
1103 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1104 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1105 ifnamebuf));
1106 return;
1107 }
1108
1109 /*
1110 * RA consistency check according to RFC 4861 6.2.7
1111 */
1112 ifi = if_indextoifinfo(pi->ipi6_ifindex);
1113 if (ifi->ifi_rainfo == NULL) {
1114 syslog(LOG_INFO,
1115 "<%s> received RA from %s on non-advertising"
1116 " interface(%s)",
1117 __func__,
1118 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1119 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1120 ifnamebuf));
1121 goto done;
1122 }
1123 rai = ifi->ifi_rainfo;
1124 ifi->ifi_rainput++;
1125 syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1126 ifi->ifi_rainput);
1127
1128 /* Cur Hop Limit value */
1129 if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1130 nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1131 syslog(LOG_NOTICE,
1132 "CurHopLimit inconsistent on %s:"
1133 " %d from %s, %d from us",
1134 ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1135 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1136 sizeof(ntopbuf)), rai->rai_hoplimit);
1137 inconsistent++;
1138 }
1139 /* M flag */
1140 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1141 rai->rai_managedflg) {
1142 syslog(LOG_NOTICE,
1143 "M flag inconsistent on %s:"
1144 " %s from %s, %s from us",
1145 ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1146 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1147 sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1148 inconsistent++;
1149 }
1150 /* O flag */
1151 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1152 rai->rai_otherflg) {
1153 syslog(LOG_NOTICE,
1154 "O flag inconsistent on %s:"
1155 " %s from %s, %s from us",
1156 ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1157 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1158 sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1159 inconsistent++;
1160 }
1161 /* Reachable Time */
1162 reachabletime = ntohl(nra->nd_ra_reachable);
1163 if (reachabletime && rai->rai_reachabletime &&
1164 reachabletime != rai->rai_reachabletime) {
1165 syslog(LOG_NOTICE,
1166 "ReachableTime inconsistent on %s:"
1167 " %d from %s, %d from us",
1168 ifi->ifi_ifname, reachabletime,
1169 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1170 sizeof(ntopbuf)), rai->rai_reachabletime);
1171 inconsistent++;
1172 }
1173 /* Retrans Timer */
1174 retranstimer = ntohl(nra->nd_ra_retransmit);
1175 if (retranstimer && rai->rai_retranstimer &&
1176 retranstimer != rai->rai_retranstimer) {
1177 syslog(LOG_NOTICE,
1178 "RetranceTimer inconsistent on %s:"
1179 " %d from %s, %d from us",
1180 ifi->ifi_ifname, retranstimer,
1181 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1182 sizeof(ntopbuf)), rai->rai_retranstimer);
1183 inconsistent++;
1184 }
1185 /* Values in the MTU options */
1186 if (ndopts.opt_mtu) {
1187 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1188 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1189 syslog(LOG_NOTICE,
1190 "MTU option value inconsistent on %s:"
1191 " %d from %s, %d from us",
1192 ifi->ifi_ifname, mtu,
1193 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1194 sizeof(ntopbuf)), rai->rai_linkmtu);
1195 inconsistent++;
1196 }
1197 }
1198 /* Preferred and Valid Lifetimes for prefixes */
1199 {
1200 struct nd_optlist *nol;
1201
1202 if (ndopts.opt_pi)
1203 if (prefix_check(ndopts.opt_pi, rai, from))
1204 inconsistent++;
1205
1206 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1207 if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1208 rai, from))
1209 inconsistent++;
1210 }
1211
1212 if (inconsistent)
1213 ifi->ifi_rainconsistent++;
1214
1215 done:
1216 free_ndopts(&ndopts);
1217 return;
1218 }
1219
1220 static uint32_t
udiff(uint32_t u,uint32_t v)1221 udiff(uint32_t u, uint32_t v)
1222 {
1223 return (u >= v ? u - v : v - u);
1224 }
1225
1226 /* return a non-zero value if the received prefix is inconsitent with ours */
1227 static int
prefix_check(struct nd_opt_prefix_info * pinfo,struct rainfo * rai,struct sockaddr_in6 * from)1228 prefix_check(struct nd_opt_prefix_info *pinfo,
1229 struct rainfo *rai, struct sockaddr_in6 *from)
1230 {
1231 struct ifinfo *ifi;
1232 uint32_t preferred_time, valid_time;
1233 struct prefix *pfx;
1234 int inconsistent = 0;
1235 char ntopbuf[INET6_ADDRSTRLEN];
1236 char prefixbuf[INET6_ADDRSTRLEN];
1237 struct timespec now;
1238
1239 #if 0 /* impossible */
1240 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1241 return (0);
1242 #endif
1243 ifi = rai->rai_ifinfo;
1244 /*
1245 * log if the adveritsed prefix has link-local scope(sanity check?)
1246 */
1247 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1248 syslog(LOG_INFO,
1249 "<%s> link-local prefix %s/%d is advertised "
1250 "from %s on %s",
1251 __func__,
1252 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1253 sizeof(prefixbuf)),
1254 pinfo->nd_opt_pi_prefix_len,
1255 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1256 sizeof(ntopbuf)), ifi->ifi_ifname);
1257
1258 if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1259 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1260 syslog(LOG_INFO,
1261 "<%s> prefix %s/%d from %s on %s is not in our list",
1262 __func__,
1263 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1264 sizeof(prefixbuf)),
1265 pinfo->nd_opt_pi_prefix_len,
1266 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1267 sizeof(ntopbuf)), ifi->ifi_ifname);
1268 return (0);
1269 }
1270
1271 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1272 if (pfx->pfx_pltimeexpire) {
1273 /*
1274 * The lifetime is decremented in real time, so we should
1275 * compare the expiration time.
1276 * (RFC 2461 Section 6.2.7.)
1277 * XXX: can we really expect that all routers on the link
1278 * have synchronized clocks?
1279 */
1280 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1281 preferred_time += now.tv_sec;
1282
1283 if (!pfx->pfx_timer && rai->rai_clockskew &&
1284 udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1285 syslog(LOG_INFO,
1286 "<%s> preferred lifetime for %s/%d"
1287 " (decr. in real time) inconsistent on %s:"
1288 " %" PRIu32 " from %s, %" PRIu32 " from us",
1289 __func__,
1290 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1291 sizeof(prefixbuf)),
1292 pinfo->nd_opt_pi_prefix_len,
1293 ifi->ifi_ifname, preferred_time,
1294 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1295 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1296 inconsistent++;
1297 }
1298 } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1299 syslog(LOG_INFO,
1300 "<%s> preferred lifetime for %s/%d"
1301 " inconsistent on %s:"
1302 " %d from %s, %d from us",
1303 __func__,
1304 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1305 sizeof(prefixbuf)),
1306 pinfo->nd_opt_pi_prefix_len,
1307 ifi->ifi_ifname, preferred_time,
1308 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1309 sizeof(ntopbuf)), pfx->pfx_preflifetime);
1310
1311 valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1312 if (pfx->pfx_vltimeexpire) {
1313 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1314 valid_time += now.tv_sec;
1315
1316 if (!pfx->pfx_timer && rai->rai_clockskew &&
1317 udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1318 syslog(LOG_INFO,
1319 "<%s> valid lifetime for %s/%d"
1320 " (decr. in real time) inconsistent on %s:"
1321 " %d from %s, %" PRIu32 " from us",
1322 __func__,
1323 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1324 sizeof(prefixbuf)),
1325 pinfo->nd_opt_pi_prefix_len,
1326 ifi->ifi_ifname, preferred_time,
1327 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1328 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1329 inconsistent++;
1330 }
1331 } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1332 syslog(LOG_INFO,
1333 "<%s> valid lifetime for %s/%d"
1334 " inconsistent on %s:"
1335 " %d from %s, %d from us",
1336 __func__,
1337 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1338 sizeof(prefixbuf)),
1339 pinfo->nd_opt_pi_prefix_len,
1340 ifi->ifi_ifname, valid_time,
1341 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1342 sizeof(ntopbuf)), pfx->pfx_validlifetime);
1343 inconsistent++;
1344 }
1345
1346 return (inconsistent);
1347 }
1348
1349 struct prefix *
find_prefix(struct rainfo * rai,struct in6_addr * prefix,int plen)1350 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1351 {
1352 struct prefix *pfx;
1353 int bytelen, bitlen;
1354 char bitmask;
1355
1356 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1357 if (plen != pfx->pfx_prefixlen)
1358 continue;
1359
1360 bytelen = plen / 8;
1361 bitlen = plen % 8;
1362 bitmask = 0xff << (8 - bitlen);
1363
1364 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1365 continue;
1366
1367 if (bitlen == 0 ||
1368 ((prefix->s6_addr[bytelen] & bitmask) ==
1369 (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1370 return (pfx);
1371 }
1372 }
1373
1374 return (NULL);
1375 }
1376
1377 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1378 int
prefix_match(struct in6_addr * p0,int plen0,struct in6_addr * p1,int plen1)1379 prefix_match(struct in6_addr *p0, int plen0,
1380 struct in6_addr *p1, int plen1)
1381 {
1382 int bytelen, bitlen;
1383 char bitmask;
1384
1385 if (plen0 < plen1)
1386 return (0);
1387
1388 bytelen = plen1 / 8;
1389 bitlen = plen1 % 8;
1390 bitmask = 0xff << (8 - bitlen);
1391
1392 if (memcmp((void *)p0, (void *)p1, bytelen))
1393 return (0);
1394
1395 if (bitlen == 0 ||
1396 ((p0->s6_addr[bytelen] & bitmask) ==
1397 (p1->s6_addr[bytelen] & bitmask))) {
1398 return (1);
1399 }
1400
1401 return (0);
1402 }
1403
1404 static int
nd6_options(struct nd_opt_hdr * hdr,int limit,union nd_opt * ndopts,uint32_t optflags)1405 nd6_options(struct nd_opt_hdr *hdr, int limit,
1406 union nd_opt *ndopts, uint32_t optflags)
1407 {
1408 int optlen = 0;
1409
1410 for (; limit > 0; limit -= optlen) {
1411 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1412 syslog(LOG_INFO, "<%s> short option header", __func__);
1413 goto bad;
1414 }
1415
1416 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1417 if (hdr->nd_opt_len == 0) {
1418 syslog(LOG_INFO,
1419 "<%s> bad ND option length(0) (type = %d)",
1420 __func__, hdr->nd_opt_type);
1421 goto bad;
1422 }
1423 optlen = hdr->nd_opt_len << 3;
1424 if (optlen > limit) {
1425 syslog(LOG_INFO, "<%s> short option", __func__);
1426 goto bad;
1427 }
1428
1429 if (hdr->nd_opt_type > ND_OPT_MTU &&
1430 hdr->nd_opt_type != ND_OPT_RDNSS &&
1431 hdr->nd_opt_type != ND_OPT_DNSSL) {
1432 syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1433 __func__, hdr->nd_opt_type);
1434 continue;
1435 }
1436
1437 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1438 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1439 __func__, hdr->nd_opt_type);
1440 continue;
1441 }
1442
1443 /*
1444 * Option length check. Do it here for all fixed-length
1445 * options.
1446 */
1447 switch (hdr->nd_opt_type) {
1448 case ND_OPT_MTU:
1449 if (optlen == sizeof(struct nd_opt_mtu))
1450 break;
1451 goto skip;
1452 case ND_OPT_RDNSS:
1453 if (optlen >= 24 &&
1454 (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1455 break;
1456 goto skip;
1457 case ND_OPT_DNSSL:
1458 if (optlen >= 16 &&
1459 (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1460 break;
1461 goto skip;
1462 case ND_OPT_PREFIX_INFORMATION:
1463 if (optlen == sizeof(struct nd_opt_prefix_info))
1464 break;
1465 skip:
1466 syslog(LOG_INFO, "<%s> invalid option length",
1467 __func__);
1468 continue;
1469 }
1470
1471 switch (hdr->nd_opt_type) {
1472 case ND_OPT_TARGET_LINKADDR:
1473 case ND_OPT_REDIRECTED_HEADER:
1474 case ND_OPT_RDNSS:
1475 case ND_OPT_DNSSL:
1476 break; /* we don't care about these options */
1477 case ND_OPT_SOURCE_LINKADDR:
1478 case ND_OPT_MTU:
1479 if (ndopts->opt_array[hdr->nd_opt_type]) {
1480 syslog(LOG_INFO,
1481 "<%s> duplicated ND option (type = %d)",
1482 __func__, hdr->nd_opt_type);
1483 }
1484 ndopts->opt_array[hdr->nd_opt_type] = hdr;
1485 break;
1486 case ND_OPT_PREFIX_INFORMATION:
1487 {
1488 struct nd_optlist *nol;
1489
1490 if (ndopts->opt_pi == 0) {
1491 ndopts->opt_pi =
1492 (struct nd_opt_prefix_info *)hdr;
1493 continue;
1494 }
1495 nol = malloc(sizeof(*nol));
1496 if (nol == NULL) {
1497 syslog(LOG_ERR, "<%s> can't allocate memory",
1498 __func__);
1499 goto bad;
1500 }
1501 nol->nol_opt = hdr;
1502 TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1503
1504 break;
1505 }
1506 default: /* impossible */
1507 break;
1508 }
1509 }
1510
1511 return (0);
1512
1513 bad:
1514 free_ndopts(ndopts);
1515
1516 return (-1);
1517 }
1518
1519 static void
free_ndopts(union nd_opt * ndopts)1520 free_ndopts(union nd_opt *ndopts)
1521 {
1522 struct nd_optlist *nol;
1523
1524 while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1525 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1526 free(nol);
1527 }
1528 }
1529
1530 void
sock_open(struct sockinfo * s)1531 sock_open(struct sockinfo *s)
1532 {
1533 struct icmp6_filter filt;
1534 int on;
1535 /* XXX: should be max MTU attached to the node */
1536 static char answer[1500];
1537
1538 syslog(LOG_DEBUG, "<%s> enter", __func__);
1539
1540 if (s == NULL) {
1541 syslog(LOG_ERR, "<%s> internal error", __func__);
1542 exit(1);
1543 }
1544 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1545 CMSG_SPACE(sizeof(int));
1546 rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1547 if (rcvcmsgbuf == NULL) {
1548 syslog(LOG_ERR, "<%s> not enough core", __func__);
1549 exit(1);
1550 }
1551
1552 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1553 CMSG_SPACE(sizeof(int));
1554 sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1555 if (sndcmsgbuf == NULL) {
1556 syslog(LOG_ERR, "<%s> not enough core", __func__);
1557 exit(1);
1558 }
1559
1560 if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1561 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1562 exit(1);
1563 }
1564 /* specify to tell receiving interface */
1565 on = 1;
1566 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1567 sizeof(on)) < 0) {
1568 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1569 strerror(errno));
1570 exit(1);
1571 }
1572 on = 1;
1573 /* specify to tell value of hoplimit field of received IP6 hdr */
1574 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1575 sizeof(on)) < 0) {
1576 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1577 strerror(errno));
1578 exit(1);
1579 }
1580 ICMP6_FILTER_SETBLOCKALL(&filt);
1581 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1582 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1583 if (mcastif != NULL)
1584 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1585
1586 if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1587 sizeof(filt)) < 0) {
1588 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1589 __func__, strerror(errno));
1590 exit(1);
1591 }
1592
1593 /* initialize msghdr for receiving packets */
1594 rcviov[0].iov_base = (caddr_t)answer;
1595 rcviov[0].iov_len = sizeof(answer);
1596 rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1597 rcvmhdr.msg_namelen = sizeof(rcvfrom);
1598 rcvmhdr.msg_iov = rcviov;
1599 rcvmhdr.msg_iovlen = 1;
1600 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1601 rcvmhdr.msg_controllen = rcvcmsgbuflen;
1602
1603 /* initialize msghdr for sending packets */
1604 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1605 sndmhdr.msg_iov = sndiov;
1606 sndmhdr.msg_iovlen = 1;
1607 sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1608 sndmhdr.msg_controllen = sndcmsgbuflen;
1609
1610 return;
1611 }
1612
1613 /* open a routing socket to watch the routing table */
1614 static void
rtsock_open(struct sockinfo * s)1615 rtsock_open(struct sockinfo *s)
1616 {
1617 if (s == NULL) {
1618 syslog(LOG_ERR, "<%s> internal error", __func__);
1619 exit(1);
1620 }
1621 if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1622 syslog(LOG_ERR,
1623 "<%s> socket: %s", __func__, strerror(errno));
1624 exit(1);
1625 }
1626 }
1627
1628 struct ifinfo *
if_indextoifinfo(int idx)1629 if_indextoifinfo(int idx)
1630 {
1631 struct ifinfo *ifi;
1632 char *name, name0[IFNAMSIZ];
1633
1634 /* Check if the interface has a valid name or not. */
1635 if (if_indextoname(idx, name0) == NULL)
1636 return (NULL);
1637
1638 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1639 if (ifi->ifi_ifindex == idx)
1640 return (ifi);
1641 }
1642
1643 if (ifi != NULL)
1644 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1645 __func__, idx);
1646 else
1647 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1648 __func__, idx);
1649
1650 return (NULL); /* search failed */
1651 }
1652
1653 void
ra_output(struct ifinfo * ifi)1654 ra_output(struct ifinfo *ifi)
1655 {
1656 int i;
1657 struct cmsghdr *cm;
1658 struct in6_pktinfo *pi;
1659 struct soliciter *sol;
1660 struct rainfo *rai;
1661
1662 switch (ifi->ifi_state) {
1663 case IFI_STATE_CONFIGURED:
1664 rai = ifi->ifi_rainfo;
1665 break;
1666 case IFI_STATE_TRANSITIVE:
1667 rai = ifi->ifi_rainfo_trans;
1668 break;
1669 case IFI_STATE_UNCONFIGURED:
1670 syslog(LOG_DEBUG, "<%s> %s is unconfigured. "
1671 "Skip sending RAs.",
1672 __func__, ifi->ifi_ifname);
1673 return;
1674 default:
1675 rai = NULL;
1676 }
1677 if (rai == NULL) {
1678 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1679 "Skip sending RAs.",
1680 __func__, ifi->ifi_ifname);
1681 return;
1682 }
1683 if (!(ifi->ifi_flags & IFF_UP)) {
1684 syslog(LOG_DEBUG, "<%s> %s is not up. "
1685 "Skip sending RAs.",
1686 __func__, ifi->ifi_ifname);
1687 return;
1688 }
1689 /*
1690 * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1691 *
1692 * (lifetime == 0) = output
1693 * (lifetime != 0 && (check_accept_rtadv()) = no output
1694 *
1695 * Basically, hosts MUST NOT send Router Advertisement
1696 * messages at any time (RFC 4861, Section 6.2.3). However, it
1697 * would sometimes be useful to allow hosts to advertise some
1698 * parameters such as prefix information and link MTU. Thus,
1699 * we allow hosts to invoke rtadvd only when router lifetime
1700 * (on every advertising interface) is explicitly set
1701 * zero. (see also the above section)
1702 */
1703 syslog(LOG_DEBUG,
1704 "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1705 "on %s", __func__,
1706 rai->rai_lifetime,
1707 check_accept_rtadv(ifi->ifi_ifindex),
1708 getinet6sysctl(IPV6CTL_FORWARDING),
1709 ifi->ifi_ifname);
1710
1711 if (rai->rai_lifetime != 0) {
1712 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1713 syslog(LOG_ERR,
1714 "non-zero lifetime RA "
1715 "but net.inet6.ip6.forwarding=0. "
1716 "Ignored.");
1717 return;
1718 }
1719 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1720 syslog(LOG_ERR,
1721 "non-zero lifetime RA "
1722 "on RA receiving interface %s."
1723 " Ignored.", ifi->ifi_ifname);
1724 return;
1725 }
1726 }
1727
1728 make_packet(rai); /* XXX: inefficient */
1729
1730 sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1731 sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1732 sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1733
1734 cm = CMSG_FIRSTHDR(&sndmhdr);
1735 /* specify the outgoing interface */
1736 cm->cmsg_level = IPPROTO_IPV6;
1737 cm->cmsg_type = IPV6_PKTINFO;
1738 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1739 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1740 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
1741 pi->ipi6_ifindex = ifi->ifi_ifindex;
1742
1743 /* specify the hop limit of the packet */
1744 {
1745 int hoplimit = 255;
1746
1747 cm = CMSG_NXTHDR(&sndmhdr, cm);
1748 cm->cmsg_level = IPPROTO_IPV6;
1749 cm->cmsg_type = IPV6_HOPLIMIT;
1750 cm->cmsg_len = CMSG_LEN(sizeof(int));
1751 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1752 }
1753
1754 syslog(LOG_DEBUG,
1755 "<%s> send RA on %s, # of RS waitings = %d",
1756 __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1757
1758 i = sendmsg(sock.si_fd, &sndmhdr, 0);
1759
1760 if (i < 0 || (size_t)i != rai->rai_ra_datalen) {
1761 if (i < 0) {
1762 syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1763 __func__, ifi->ifi_ifname,
1764 strerror(errno));
1765 }
1766 }
1767
1768 /*
1769 * unicast advertisements
1770 * XXX commented out. reason: though spec does not forbit it, unicast
1771 * advert does not really help
1772 */
1773 while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1774 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1775 free(sol);
1776 }
1777
1778 /* update timestamp */
1779 clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1780
1781 /* update counter */
1782 ifi->ifi_rs_waitcount = 0;
1783 ifi->ifi_raoutput++;
1784
1785 switch (ifi->ifi_state) {
1786 case IFI_STATE_CONFIGURED:
1787 if (ifi->ifi_burstcount > 0)
1788 ifi->ifi_burstcount--;
1789 break;
1790 case IFI_STATE_TRANSITIVE:
1791 ifi->ifi_burstcount--;
1792 if (ifi->ifi_burstcount == 0) {
1793 if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1794 /* Initial burst finished. */
1795 if (ifi->ifi_rainfo_trans != NULL)
1796 ifi->ifi_rainfo_trans = NULL;
1797 }
1798
1799 /* Remove burst RA information */
1800 if (ifi->ifi_rainfo_trans != NULL) {
1801 rm_rainfo(ifi->ifi_rainfo_trans);
1802 ifi->ifi_rainfo_trans = NULL;
1803 }
1804
1805 if (ifi->ifi_rainfo != NULL) {
1806 /*
1807 * TRANSITIVE -> CONFIGURED
1808 *
1809 * After initial burst or transition from
1810 * one configuration to another,
1811 * ifi_rainfo always points to the next RA
1812 * information.
1813 */
1814 ifi->ifi_state = IFI_STATE_CONFIGURED;
1815 syslog(LOG_DEBUG,
1816 "<%s> ifname=%s marked as "
1817 "CONFIGURED.", __func__,
1818 ifi->ifi_ifname);
1819 } else {
1820 /*
1821 * TRANSITIVE -> UNCONFIGURED
1822 *
1823 * If ifi_rainfo points to NULL, this
1824 * interface is shutting down.
1825 *
1826 */
1827 int error;
1828
1829 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1830 syslog(LOG_DEBUG,
1831 "<%s> ifname=%s marked as "
1832 "UNCONFIGURED.", __func__,
1833 ifi->ifi_ifname);
1834 error = sock_mc_leave(&sock,
1835 ifi->ifi_ifindex);
1836 if (error)
1837 exit(1);
1838 }
1839 }
1840 break;
1841 }
1842 }
1843
1844 /* process RA timer */
1845 struct rtadvd_timer *
ra_timeout(void * arg)1846 ra_timeout(void *arg)
1847 {
1848 struct ifinfo *ifi;
1849
1850 ifi = (struct ifinfo *)arg;
1851 syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1852 __func__, ifi->ifi_ifname);
1853
1854 ra_output(ifi);
1855
1856 return (ifi->ifi_ra_timer);
1857 }
1858
1859 /* update RA timer */
1860 void
ra_timer_update(void * arg,struct timespec * tm)1861 ra_timer_update(void *arg, struct timespec *tm)
1862 {
1863 uint16_t interval;
1864 struct rainfo *rai;
1865 struct ifinfo *ifi;
1866
1867 ifi = (struct ifinfo *)arg;
1868 rai = ifi->ifi_rainfo;
1869 interval = 0;
1870
1871 switch (ifi->ifi_state) {
1872 case IFI_STATE_UNCONFIGURED:
1873 return;
1874 break;
1875 case IFI_STATE_CONFIGURED:
1876 /*
1877 * Whenever a multicast advertisement is sent from
1878 * an interface, the timer is reset to a
1879 * uniformly-distributed random value between the
1880 * interface's configured MinRtrAdvInterval and
1881 * MaxRtrAdvInterval (RFC4861 6.2.4).
1882 */
1883 interval = rai->rai_mininterval;
1884 interval += arc4random_uniform(rai->rai_maxinterval -
1885 rai->rai_mininterval);
1886 break;
1887 case IFI_STATE_TRANSITIVE:
1888 /*
1889 * For the first few advertisements (up to
1890 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1891 * interval is greater than
1892 * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1893 * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC
1894 * 4861 6.2.4)
1895 *
1896 * In such cases, the router SHOULD transmit one or more
1897 * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1898 * multicast Router Advertisements on the interface with a
1899 * Router Lifetime field of zero. (RFC 4861 6.2.5)
1900 */
1901 interval = ifi->ifi_burstinterval;
1902 break;
1903 }
1904
1905 tm->tv_sec = interval;
1906 tm->tv_nsec = 0;
1907
1908 syslog(LOG_DEBUG,
1909 "<%s> RA timer on %s is set to %ld:%ld",
1910 __func__, ifi->ifi_ifname,
1911 (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1912
1913 return;
1914 }
1915