1 /* $FreeBSD: stable/9/usr.sbin/rtadvd/rtadvd.c 275038 2014-11-25 13:12:45Z dim $ */
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/time.h>
39 #include <sys/queue.h>
40 #include <sys/stat.h>
41 #include <sys/sysctl.h>
42
43 #include <net/if.h>
44 #include <net/if_types.h>
45 #include <net/if_media.h>
46 #include <net/if_dl.h>
47 #include <net/route.h>
48 #include <netinet/in.h>
49 #include <netinet/ip6.h>
50 #include <netinet6/ip6_var.h>
51 #include <netinet/icmp6.h>
52
53 #include <arpa/inet.h>
54
55 #include <net/if_var.h>
56 #include <netinet/in_var.h>
57 #include <netinet6/nd6.h>
58
59 #include <time.h>
60 #include <unistd.h>
61 #include <stdio.h>
62 #include <err.h>
63 #include <errno.h>
64 #include <inttypes.h>
65 #include <libutil.h>
66 #include <netdb.h>
67 #include <signal.h>
68 #include <string.h>
69 #include <stdlib.h>
70 #include <syslog.h>
71 #include <poll.h>
72
73 #include "pathnames.h"
74 #include "rtadvd.h"
75 #include "if.h"
76 #include "rrenum.h"
77 #include "advcap.h"
78 #include "timer_subr.h"
79 #include "timer.h"
80 #include "config.h"
81 #include "control.h"
82 #include "control_server.h"
83
84 #define RTADV_TYPE2BITMASK(type) (0x1 << type)
85
86 struct msghdr rcvmhdr;
87 static char *rcvcmsgbuf;
88 static size_t rcvcmsgbuflen;
89 static char *sndcmsgbuf = NULL;
90 static size_t sndcmsgbuflen;
91 struct msghdr sndmhdr;
92 struct iovec rcviov[2];
93 struct iovec sndiov[2];
94 struct sockaddr_in6 rcvfrom;
95 static const char *pidfilename = _PATH_RTADVDPID;
96 const char *conffile = _PATH_RTADVDCONF;
97 static struct pidfh *pfh;
98 static int dflag, sflag;
99 static int wait_shutdown;
100
101 #define PFD_RAWSOCK 0
102 #define PFD_RTSOCK 1
103 #define PFD_CSOCK 2
104 #define PFD_MAX 3
105
106 struct railist_head_t railist =
107 TAILQ_HEAD_INITIALIZER(railist);
108 struct ifilist_head_t ifilist =
109 TAILQ_HEAD_INITIALIZER(ifilist);
110
111 struct nd_optlist {
112 TAILQ_ENTRY(nd_optlist) nol_next;
113 struct nd_opt_hdr *nol_opt;
114 };
115 union nd_opt {
116 struct nd_opt_hdr *opt_array[9];
117 struct {
118 struct nd_opt_hdr *zero;
119 struct nd_opt_hdr *src_lladdr;
120 struct nd_opt_hdr *tgt_lladdr;
121 struct nd_opt_prefix_info *pi;
122 struct nd_opt_rd_hdr *rh;
123 struct nd_opt_mtu *mtu;
124 TAILQ_HEAD(, nd_optlist) opt_list;
125 } nd_opt_each;
126 };
127 #define opt_src_lladdr nd_opt_each.src_lladdr
128 #define opt_tgt_lladdr nd_opt_each.tgt_lladdr
129 #define opt_pi nd_opt_each.pi
130 #define opt_rh nd_opt_each.rh
131 #define opt_mtu nd_opt_each.mtu
132 #define opt_list nd_opt_each.opt_list
133
134 #define NDOPT_FLAG_SRCLINKADDR (1 << 0)
135 #define NDOPT_FLAG_TGTLINKADDR (1 << 1)
136 #define NDOPT_FLAG_PREFIXINFO (1 << 2)
137 #define NDOPT_FLAG_RDHDR (1 << 3)
138 #define NDOPT_FLAG_MTU (1 << 4)
139 #define NDOPT_FLAG_RDNSS (1 << 5)
140 #define NDOPT_FLAG_DNSSL (1 << 6)
141
142 static uint32_t ndopt_flags[] = {
143 [ND_OPT_SOURCE_LINKADDR] = NDOPT_FLAG_SRCLINKADDR,
144 [ND_OPT_TARGET_LINKADDR] = NDOPT_FLAG_TGTLINKADDR,
145 [ND_OPT_PREFIX_INFORMATION] = NDOPT_FLAG_PREFIXINFO,
146 [ND_OPT_REDIRECTED_HEADER] = NDOPT_FLAG_RDHDR,
147 [ND_OPT_MTU] = NDOPT_FLAG_MTU,
148 [ND_OPT_RDNSS] = NDOPT_FLAG_RDNSS,
149 [ND_OPT_DNSSL] = NDOPT_FLAG_DNSSL,
150 };
151
152 static void rtadvd_shutdown(void);
153 static void sock_open(struct sockinfo *);
154 static void rtsock_open(struct sockinfo *);
155 static void rtadvd_input(struct sockinfo *);
156 static void rs_input(int, struct nd_router_solicit *,
157 struct in6_pktinfo *, struct sockaddr_in6 *);
158 static void ra_input(int, struct nd_router_advert *,
159 struct in6_pktinfo *, struct sockaddr_in6 *);
160 static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
161 struct sockaddr_in6 *);
162 static int nd6_options(struct nd_opt_hdr *, int,
163 union nd_opt *, uint32_t);
164 static void free_ndopts(union nd_opt *);
165 static void rtmsg_input(struct sockinfo *);
166 static void set_short_delay(struct ifinfo *);
167 static int check_accept_rtadv(int);
168
169 static void
usage(void)170 usage(void)
171 {
172
173 fprintf(stderr, "usage: rtadvd [-dDfRs] "
174 "[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n");
175 exit(1);
176 }
177
178 int
main(int argc,char * argv[])179 main(int argc, char *argv[])
180 {
181 struct pollfd set[PFD_MAX];
182 struct timeval *timeout;
183 int i, ch;
184 int fflag = 0, logopt;
185 int error;
186 pid_t pid, otherpid;
187
188 /* get command line options and arguments */
189 while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) {
190 switch (ch) {
191 case 'c':
192 conffile = optarg;
193 break;
194 case 'C':
195 ctrlsock.si_name = optarg;
196 break;
197 case 'd':
198 dflag++;
199 break;
200 case 'D':
201 dflag += 3;
202 break;
203 case 'f':
204 fflag = 1;
205 break;
206 case 'M':
207 mcastif = optarg;
208 break;
209 case 'R':
210 fprintf(stderr, "rtadvd: "
211 "the -R option is currently ignored.\n");
212 /* accept_rr = 1; */
213 /* run anyway... */
214 break;
215 case 's':
216 sflag = 1;
217 break;
218 case 'p':
219 pidfilename = optarg;
220 break;
221 default:
222 usage();
223 }
224 }
225 argc -= optind;
226 argv += optind;
227
228 logopt = LOG_NDELAY | LOG_PID;
229 if (fflag)
230 logopt |= LOG_PERROR;
231 openlog("rtadvd", logopt, LOG_DAEMON);
232
233 /* set log level */
234 if (dflag > 2)
235 (void)setlogmask(LOG_UPTO(LOG_DEBUG));
236 else if (dflag > 1)
237 (void)setlogmask(LOG_UPTO(LOG_INFO));
238 else if (dflag > 0)
239 (void)setlogmask(LOG_UPTO(LOG_NOTICE));
240 else
241 (void)setlogmask(LOG_UPTO(LOG_ERR));
242
243 /* timer initialization */
244 rtadvd_timer_init();
245
246 #ifndef HAVE_ARC4RANDOM
247 /* random value initialization */
248 #ifdef __FreeBSD__
249 srandomdev();
250 #else
251 srandom((unsigned long)time(NULL));
252 #endif
253 #endif
254 pfh = pidfile_open(pidfilename, 0600, &otherpid);
255 if (pfh == NULL) {
256 if (errno == EEXIST)
257 errx(1, "%s already running, pid: %d",
258 getprogname(), otherpid);
259 syslog(LOG_ERR,
260 "failed to open the pid file %s, run anyway.",
261 pidfilename);
262 }
263 if (!fflag)
264 daemon(1, 0);
265
266 sock_open(&sock);
267
268 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
269 for (i = 0; i < argc; i++)
270 update_persist_ifinfo(&ifilist, argv[i]);
271
272 csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
273 if (ctrlsock.si_fd == -1) {
274 syslog(LOG_ERR, "cannot open control socket: %s",
275 strerror(errno));
276 exit(1);
277 }
278
279 /* record the current PID */
280 pid = getpid();
281 pidfile_write(pfh);
282
283 set[PFD_RAWSOCK].fd = sock.si_fd;
284 set[PFD_RAWSOCK].events = POLLIN;
285 if (sflag == 0) {
286 rtsock_open(&rtsock);
287 set[PFD_RTSOCK].fd = rtsock.si_fd;
288 set[PFD_RTSOCK].events = POLLIN;
289 } else
290 set[PFD_RTSOCK].fd = -1;
291 set[PFD_CSOCK].fd = ctrlsock.si_fd;
292 set[PFD_CSOCK].events = POLLIN;
293 signal(SIGTERM, set_do_shutdown);
294 signal(SIGINT, set_do_shutdown);
295 signal(SIGHUP, set_do_reload);
296
297 error = csock_listen(&ctrlsock);
298 if (error) {
299 syslog(LOG_ERR, "cannot listen control socket: %s",
300 strerror(errno));
301 exit(1);
302 }
303
304 /* load configuration file */
305 set_do_reload(0);
306
307 while (1) {
308 if (is_do_shutdown())
309 rtadvd_shutdown();
310
311 if (is_do_reload()) {
312 loadconfig_ifname(reload_ifname());
313 if (reload_ifname() == NULL)
314 syslog(LOG_INFO,
315 "configuration file reloaded.");
316 else
317 syslog(LOG_INFO,
318 "configuration file for %s reloaded.",
319 reload_ifname());
320 reset_do_reload();
321 }
322
323 /* timeout handler update for active interfaces */
324 rtadvd_update_timeout_handler();
325
326 /* timer expiration check and reset the timer */
327 timeout = rtadvd_check_timer();
328
329 if (timeout != NULL) {
330 syslog(LOG_DEBUG,
331 "<%s> set timer to %ld:%ld. waiting for "
332 "inputs or timeout", __func__,
333 (long int)timeout->tv_sec,
334 (long int)timeout->tv_usec);
335 } else {
336 syslog(LOG_DEBUG,
337 "<%s> there's no timer. waiting for inputs",
338 __func__);
339 }
340 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
341 timeout ? (timeout->tv_sec * 1000 +
342 timeout->tv_usec / 1000) : INFTIM)) < 0) {
343
344 /* EINTR would occur if a signal was delivered */
345 if (errno != EINTR)
346 syslog(LOG_ERR, "poll() failed: %s",
347 strerror(errno));
348 continue;
349 }
350 if (i == 0) /* timeout */
351 continue;
352 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
353 rtmsg_input(&rtsock);
354
355 if (set[PFD_RAWSOCK].revents & POLLIN)
356 rtadvd_input(&sock);
357
358 if (set[PFD_CSOCK].revents & POLLIN) {
359 int fd;
360
361 fd = csock_accept(&ctrlsock);
362 if (fd == -1)
363 syslog(LOG_ERR,
364 "cannot accept() control socket: %s",
365 strerror(errno));
366 else {
367 cm_handler_server(fd);
368 close(fd);
369 }
370 }
371 }
372 exit(0); /* NOTREACHED */
373 }
374
375 static void
rtadvd_shutdown(void)376 rtadvd_shutdown(void)
377 {
378 struct ifinfo *ifi;
379 struct rainfo *rai;
380 struct rdnss *rdn;
381 struct dnssl *dns;
382
383 if (wait_shutdown) {
384 syslog(LOG_INFO,
385 "waiting expiration of the all RA timers.");
386
387 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
388 /*
389 * Ignore !IFF_UP interfaces in waiting for shutdown.
390 */
391 if (!(ifi->ifi_flags & IFF_UP) &&
392 ifi->ifi_ra_timer != NULL) {
393 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
394 rtadvd_remove_timer(ifi->ifi_ra_timer);
395 ifi->ifi_ra_timer = NULL;
396 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
397 "Timer removed and marked as UNCONFIGURED.",
398 __func__, ifi->ifi_ifname,
399 ifi->ifi_ifindex);
400 }
401 }
402 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
403 if (ifi->ifi_ra_timer != NULL)
404 break;
405 }
406 if (ifi == NULL) {
407 syslog(LOG_NOTICE, "gracefully terminated.");
408 exit(0);
409 }
410
411 sleep(1);
412 return;
413 }
414
415 syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
416 __func__);
417
418 wait_shutdown = 1;
419
420 TAILQ_FOREACH(rai, &railist, rai_next) {
421 rai->rai_lifetime = 0;
422 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
423 rdn->rd_ltime = 0;
424 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
425 dns->dn_ltime = 0;
426 }
427 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
428 if (!ifi->ifi_persist)
429 continue;
430 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
431 continue;
432 if (ifi->ifi_ra_timer == NULL)
433 continue;
434 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
435 ifi->ifi_ra_lastsent.tv_usec == 0 &&
436 ifi->ifi_ra_timer != NULL) {
437 /*
438 * When RA configured but never sent,
439 * ignore the IF immediately.
440 */
441 rtadvd_remove_timer(ifi->ifi_ra_timer);
442 ifi->ifi_ra_timer = NULL;
443 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
444 continue;
445 }
446
447 ifi->ifi_state = IFI_STATE_TRANSITIVE;
448
449 /* Mark as the shut-down state. */
450 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
451 ifi->ifi_rainfo = NULL;
452
453 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
454 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
455
456 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
457 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
458 ifi->ifi_ra_timer);
459 }
460 syslog(LOG_NOTICE, "final RA transmission started.");
461
462 pidfile_remove(pfh);
463 csock_close(&ctrlsock);
464 }
465
466 static void
rtmsg_input(struct sockinfo * s)467 rtmsg_input(struct sockinfo *s)
468 {
469 int n, type, ifindex = 0, plen;
470 size_t len;
471 char msg[2048], *next, *lim;
472 char ifname[IFNAMSIZ];
473 struct if_announcemsghdr *ifan;
474 struct rt_msghdr *rtm;
475 struct prefix *pfx;
476 struct rainfo *rai;
477 struct in6_addr *addr;
478 struct ifinfo *ifi;
479 char addrbuf[INET6_ADDRSTRLEN];
480 int prefixchange = 0;
481
482 if (s == NULL) {
483 syslog(LOG_ERR, "<%s> internal error", __func__);
484 exit(1);
485 }
486 n = read(s->si_fd, msg, sizeof(msg));
487 rtm = (struct rt_msghdr *)msg;
488 syslog(LOG_DEBUG, "<%s> received a routing message "
489 "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
490
491 if (n > rtm->rtm_msglen) {
492 /*
493 * This usually won't happen for messages received on
494 * a routing socket.
495 */
496 syslog(LOG_DEBUG,
497 "<%s> received data length is larger than "
498 "1st routing message len. multiple messages? "
499 "read %d bytes, but 1st msg len = %d",
500 __func__, n, rtm->rtm_msglen);
501 #if 0
502 /* adjust length */
503 n = rtm->rtm_msglen;
504 #endif
505 }
506
507 lim = msg + n;
508 for (next = msg; next < lim; next += len) {
509 int oldifflags;
510
511 next = get_next_msg(next, lim, 0, &len,
512 RTADV_TYPE2BITMASK(RTM_ADD) |
513 RTADV_TYPE2BITMASK(RTM_DELETE) |
514 RTADV_TYPE2BITMASK(RTM_NEWADDR) |
515 RTADV_TYPE2BITMASK(RTM_DELADDR) |
516 RTADV_TYPE2BITMASK(RTM_IFINFO) |
517 RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
518 if (len == 0)
519 break;
520 type = ((struct rt_msghdr *)next)->rtm_type;
521 switch (type) {
522 case RTM_ADD:
523 case RTM_DELETE:
524 ifindex = get_rtm_ifindex(next);
525 break;
526 case RTM_NEWADDR:
527 case RTM_DELADDR:
528 ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
529 break;
530 case RTM_IFINFO:
531 ifindex = (int)((struct if_msghdr *)next)->ifm_index;
532 break;
533 case RTM_IFANNOUNCE:
534 ifan = (struct if_announcemsghdr *)next;
535 switch (ifan->ifan_what) {
536 case IFAN_ARRIVAL:
537 case IFAN_DEPARTURE:
538 break;
539 default:
540 syslog(LOG_DEBUG,
541 "<%s:%d> unknown ifan msg (ifan_what=%d)",
542 __func__, __LINE__, ifan->ifan_what);
543 continue;
544 }
545
546 syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
547 __func__, ifan->ifan_index, ifan->ifan_what);
548 switch (ifan->ifan_what) {
549 case IFAN_ARRIVAL:
550 syslog(LOG_NOTICE,
551 "interface added (idx=%d)",
552 ifan->ifan_index);
553 update_ifinfo(&ifilist, ifan->ifan_index);
554 loadconfig_index(ifan->ifan_index);
555 break;
556 case IFAN_DEPARTURE:
557 syslog(LOG_NOTICE,
558 "interface removed (idx=%d)",
559 ifan->ifan_index);
560 rm_ifinfo_index(ifan->ifan_index);
561
562 /* Clear ifi_ifindex */
563 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
564 if (ifi->ifi_ifindex
565 == ifan->ifan_index) {
566 ifi->ifi_ifindex = 0;
567 break;
568 }
569 }
570 update_ifinfo(&ifilist, ifan->ifan_index);
571 break;
572 }
573 continue;
574 default:
575 /* should not reach here */
576 syslog(LOG_DEBUG,
577 "<%s:%d> unknown rtmsg %d on %s",
578 __func__, __LINE__, type,
579 if_indextoname(ifindex, ifname));
580 continue;
581 }
582 ifi = if_indextoifinfo(ifindex);
583 if (ifi == NULL) {
584 syslog(LOG_DEBUG,
585 "<%s> ifinfo not found for idx=%d. Why?",
586 __func__, ifindex);
587 continue;
588 }
589 rai = ifi->ifi_rainfo;
590 if (rai == NULL) {
591 syslog(LOG_DEBUG,
592 "<%s> route changed on "
593 "non advertising interface(%s)",
594 __func__, ifi->ifi_ifname);
595 continue;
596 }
597
598 oldifflags = ifi->ifi_flags;
599 /* init ifflags because it may have changed */
600 update_ifinfo(&ifilist, ifindex);
601
602 switch (type) {
603 case RTM_ADD:
604 if (sflag)
605 break; /* we aren't interested in prefixes */
606
607 addr = get_addr(msg);
608 plen = get_prefixlen(msg);
609 /* sanity check for plen */
610 /* as RFC2373, prefixlen is at least 4 */
611 if (plen < 4 || plen > 127) {
612 syslog(LOG_INFO, "<%s> new interface route's"
613 "plen %d is invalid for a prefix",
614 __func__, plen);
615 break;
616 }
617 pfx = find_prefix(rai, addr, plen);
618 if (pfx) {
619 if (pfx->pfx_timer) {
620 /*
621 * If the prefix has been invalidated,
622 * make it available again.
623 */
624 update_prefix(pfx);
625 prefixchange = 1;
626 } else
627 syslog(LOG_DEBUG,
628 "<%s> new prefix(%s/%d) "
629 "added on %s, "
630 "but it was already in list",
631 __func__,
632 inet_ntop(AF_INET6, addr,
633 (char *)addrbuf,
634 sizeof(addrbuf)),
635 plen, ifi->ifi_ifname);
636 break;
637 }
638 make_prefix(rai, ifindex, addr, plen);
639 prefixchange = 1;
640 break;
641 case RTM_DELETE:
642 if (sflag)
643 break;
644
645 addr = get_addr(msg);
646 plen = get_prefixlen(msg);
647 /* sanity check for plen */
648 /* as RFC2373, prefixlen is at least 4 */
649 if (plen < 4 || plen > 127) {
650 syslog(LOG_INFO,
651 "<%s> deleted interface route's "
652 "plen %d is invalid for a prefix",
653 __func__, plen);
654 break;
655 }
656 pfx = find_prefix(rai, addr, plen);
657 if (pfx == NULL) {
658 syslog(LOG_DEBUG,
659 "<%s> prefix(%s/%d) was deleted on %s, "
660 "but it was not in list",
661 __func__, inet_ntop(AF_INET6, addr,
662 (char *)addrbuf, sizeof(addrbuf)),
663 plen, ifi->ifi_ifname);
664 break;
665 }
666 invalidate_prefix(pfx);
667 prefixchange = 1;
668 break;
669 case RTM_NEWADDR:
670 case RTM_DELADDR:
671 case RTM_IFINFO:
672 break;
673 default:
674 /* should not reach here */
675 syslog(LOG_DEBUG,
676 "<%s:%d> unknown rtmsg %d on %s",
677 __func__, __LINE__, type,
678 if_indextoname(ifindex, ifname));
679 return;
680 }
681
682 /* check if an interface flag is changed */
683 if ((oldifflags & IFF_UP) && /* UP to DOWN */
684 !(ifi->ifi_flags & IFF_UP)) {
685 syslog(LOG_NOTICE,
686 "<interface %s becomes down. stop timer.",
687 ifi->ifi_ifname);
688 rtadvd_remove_timer(ifi->ifi_ra_timer);
689 ifi->ifi_ra_timer = NULL;
690 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
691 (ifi->ifi_flags & IFF_UP)) {
692 syslog(LOG_NOTICE,
693 "interface %s becomes up. restart timer.",
694 ifi->ifi_ifname);
695
696 ifi->ifi_state = IFI_STATE_TRANSITIVE;
697 ifi->ifi_burstcount =
698 MAX_INITIAL_RTR_ADVERTISEMENTS;
699 ifi->ifi_burstinterval =
700 MAX_INITIAL_RTR_ADVERT_INTERVAL;
701
702 ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
703 ra_timer_update, ifi, ifi);
704 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
705 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
706 ifi->ifi_ra_timer);
707 } else if (prefixchange &&
708 (ifi->ifi_flags & IFF_UP)) {
709 /*
710 * An advertised prefix has been added or invalidated.
711 * Will notice the change in a short delay.
712 */
713 set_short_delay(ifi);
714 }
715 }
716
717 return;
718 }
719
720 void
rtadvd_input(struct sockinfo * s)721 rtadvd_input(struct sockinfo *s)
722 {
723 ssize_t i;
724 int *hlimp = NULL;
725 #ifdef OLDRAWSOCKET
726 struct ip6_hdr *ip;
727 #endif
728 struct icmp6_hdr *icp;
729 int ifindex = 0;
730 struct cmsghdr *cm;
731 struct in6_pktinfo *pi = NULL;
732 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
733 struct in6_addr dst = in6addr_any;
734 struct ifinfo *ifi;
735
736 syslog(LOG_DEBUG, "<%s> enter", __func__);
737
738 if (s == NULL) {
739 syslog(LOG_ERR, "<%s> internal error", __func__);
740 exit(1);
741 }
742 /*
743 * Get message. We reset msg_controllen since the field could
744 * be modified if we had received a message before setting
745 * receive options.
746 */
747 rcvmhdr.msg_controllen = rcvcmsgbuflen;
748 if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
749 return;
750
751 /* extract optional information via Advanced API */
752 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
753 cm;
754 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
755 if (cm->cmsg_level == IPPROTO_IPV6 &&
756 cm->cmsg_type == IPV6_PKTINFO &&
757 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
758 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
759 ifindex = pi->ipi6_ifindex;
760 dst = pi->ipi6_addr;
761 }
762 if (cm->cmsg_level == IPPROTO_IPV6 &&
763 cm->cmsg_type == IPV6_HOPLIMIT &&
764 cm->cmsg_len == CMSG_LEN(sizeof(int)))
765 hlimp = (int *)CMSG_DATA(cm);
766 }
767 if (ifindex == 0) {
768 syslog(LOG_ERR, "failed to get receiving interface");
769 return;
770 }
771 if (hlimp == NULL) {
772 syslog(LOG_ERR, "failed to get receiving hop limit");
773 return;
774 }
775
776 /*
777 * If we happen to receive data on an interface which is now gone
778 * or down, just discard the data.
779 */
780 ifi = if_indextoifinfo(pi->ipi6_ifindex);
781 if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
782 syslog(LOG_INFO,
783 "<%s> received data on a disabled interface (%s)",
784 __func__,
785 (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
786 return;
787 }
788
789 #ifdef OLDRAWSOCKET
790 if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
791 syslog(LOG_ERR,
792 "packet size(%d) is too short", i);
793 return;
794 }
795
796 ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
797 icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
798 #else
799 if ((size_t)i < sizeof(struct icmp6_hdr)) {
800 syslog(LOG_ERR, "packet size(%zd) is too short", i);
801 return;
802 }
803
804 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
805 #endif
806
807 switch (icp->icmp6_type) {
808 case ND_ROUTER_SOLICIT:
809 /*
810 * Message verification - RFC 4861 6.1.1
811 * XXX: these checks must be done in the kernel as well,
812 * but we can't completely rely on them.
813 */
814 if (*hlimp != 255) {
815 syslog(LOG_NOTICE,
816 "RS with invalid hop limit(%d) "
817 "received from %s on %s",
818 *hlimp,
819 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
820 sizeof(ntopbuf)),
821 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
822 return;
823 }
824 if (icp->icmp6_code) {
825 syslog(LOG_NOTICE,
826 "RS with invalid ICMP6 code(%d) "
827 "received from %s on %s",
828 icp->icmp6_code,
829 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
830 sizeof(ntopbuf)),
831 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
832 return;
833 }
834 if ((size_t)i < sizeof(struct nd_router_solicit)) {
835 syslog(LOG_NOTICE,
836 "RS from %s on %s does not have enough "
837 "length (len = %zd)",
838 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
839 sizeof(ntopbuf)),
840 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
841 return;
842 }
843 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
844 break;
845 case ND_ROUTER_ADVERT:
846 /*
847 * Message verification - RFC 4861 6.1.2
848 * XXX: there's the same dilemma as above...
849 */
850 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
851 syslog(LOG_NOTICE,
852 "RA witn non-linklocal source address "
853 "received from %s on %s",
854 inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
855 ntopbuf, sizeof(ntopbuf)),
856 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
857 return;
858 }
859 if (*hlimp != 255) {
860 syslog(LOG_NOTICE,
861 "RA with invalid hop limit(%d) "
862 "received from %s on %s",
863 *hlimp,
864 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
865 sizeof(ntopbuf)),
866 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
867 return;
868 }
869 if (icp->icmp6_code) {
870 syslog(LOG_NOTICE,
871 "RA with invalid ICMP6 code(%d) "
872 "received from %s on %s",
873 icp->icmp6_code,
874 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
875 sizeof(ntopbuf)),
876 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
877 return;
878 }
879 if ((size_t)i < sizeof(struct nd_router_advert)) {
880 syslog(LOG_NOTICE,
881 "RA from %s on %s does not have enough "
882 "length (len = %zd)",
883 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
884 sizeof(ntopbuf)),
885 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
886 return;
887 }
888 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
889 break;
890 case ICMP6_ROUTER_RENUMBERING:
891 if (mcastif == NULL) {
892 syslog(LOG_ERR, "received a router renumbering "
893 "message, but not allowed to be accepted");
894 break;
895 }
896 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
897 &dst);
898 break;
899 default:
900 /*
901 * Note that this case is POSSIBLE, especially just
902 * after invocation of the daemon. This is because we
903 * could receive message after opening the socket and
904 * before setting ICMP6 type filter(see sock_open()).
905 */
906 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
907 return;
908 }
909
910 return;
911 }
912
913 static void
rs_input(int len,struct nd_router_solicit * rs,struct in6_pktinfo * pi,struct sockaddr_in6 * from)914 rs_input(int len, struct nd_router_solicit *rs,
915 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
916 {
917 char ntopbuf[INET6_ADDRSTRLEN];
918 char ifnamebuf[IFNAMSIZ];
919 union nd_opt ndopts;
920 struct rainfo *rai;
921 struct ifinfo *ifi;
922 struct soliciter *sol;
923
924 syslog(LOG_DEBUG,
925 "<%s> RS received from %s on %s",
926 __func__,
927 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
928 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
929
930 /* ND option check */
931 memset(&ndopts, 0, sizeof(ndopts));
932 TAILQ_INIT(&ndopts.opt_list);
933 if (nd6_options((struct nd_opt_hdr *)(rs + 1),
934 len - sizeof(struct nd_router_solicit),
935 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
936 syslog(LOG_INFO,
937 "<%s> ND option check failed for an RS from %s on %s",
938 __func__,
939 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
940 sizeof(ntopbuf)),
941 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
942 return;
943 }
944
945 /*
946 * If the IP source address is the unspecified address, there
947 * must be no source link-layer address option in the message.
948 * (RFC 4861 6.1.1)
949 */
950 if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
951 ndopts.opt_src_lladdr) {
952 syslog(LOG_INFO,
953 "<%s> RS from unspecified src on %s has a link-layer"
954 " address option",
955 __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
956 goto done;
957 }
958
959 ifi = if_indextoifinfo(pi->ipi6_ifindex);
960 if (ifi == NULL) {
961 syslog(LOG_INFO,
962 "<%s> if (idx=%d) not found. Why?",
963 __func__, pi->ipi6_ifindex);
964 goto done;
965 }
966 rai = ifi->ifi_rainfo;
967 if (rai == NULL) {
968 syslog(LOG_INFO,
969 "<%s> RS received on non advertising interface(%s)",
970 __func__,
971 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
972 goto done;
973 }
974
975 rai->rai_ifinfo->ifi_rsinput++;
976
977 /*
978 * Decide whether to send RA according to the rate-limit
979 * consideration.
980 */
981
982 /* record sockaddr waiting for RA, if possible */
983 sol = (struct soliciter *)malloc(sizeof(*sol));
984 if (sol) {
985 sol->sol_addr = *from;
986 /* XXX RFC 2553 need clarification on flowinfo */
987 sol->sol_addr.sin6_flowinfo = 0;
988 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
989 }
990
991 /*
992 * If there is already a waiting RS packet, don't
993 * update the timer.
994 */
995 if (ifi->ifi_rs_waitcount++)
996 goto done;
997
998 set_short_delay(ifi);
999
1000 done:
1001 free_ndopts(&ndopts);
1002 return;
1003 }
1004
1005 static void
set_short_delay(struct ifinfo * ifi)1006 set_short_delay(struct ifinfo *ifi)
1007 {
1008 long delay; /* must not be greater than 1000000 */
1009 struct timeval interval, now, min_delay, tm_tmp, *rest;
1010
1011 if (ifi->ifi_ra_timer == NULL)
1012 return;
1013 /*
1014 * Compute a random delay. If the computed value
1015 * corresponds to a time later than the time the next
1016 * multicast RA is scheduled to be sent, ignore the random
1017 * delay and send the advertisement at the
1018 * already-scheduled time. RFC 4861 6.2.6
1019 */
1020 #ifdef HAVE_ARC4RANDOM
1021 delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1022 #else
1023 delay = random() % MAX_RA_DELAY_TIME;
1024 #endif
1025 interval.tv_sec = 0;
1026 interval.tv_usec = delay;
1027 rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1028 if (TIMEVAL_LT(rest, &interval)) {
1029 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1030 "the rest of the current timer", __func__);
1031 interval = *rest;
1032 }
1033
1034 /*
1035 * If we sent a multicast Router Advertisement within
1036 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1037 * the advertisement to be sent at a time corresponding to
1038 * MIN_DELAY_BETWEEN_RAS plus the random value after the
1039 * previous advertisement was sent.
1040 */
1041 gettimeofday(&now, NULL);
1042 TIMEVAL_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1043 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1044 min_delay.tv_usec = 0;
1045 if (TIMEVAL_LT(&tm_tmp, &min_delay)) {
1046 TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
1047 TIMEVAL_ADD(&min_delay, &interval, &interval);
1048 }
1049 rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1050 }
1051
1052 static int
check_accept_rtadv(int idx)1053 check_accept_rtadv(int idx)
1054 {
1055 struct ifinfo *ifi;
1056
1057 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1058 if (ifi->ifi_ifindex == idx)
1059 break;
1060 }
1061 if (ifi == NULL) {
1062 syslog(LOG_DEBUG,
1063 "<%s> if (idx=%d) not found. Why?",
1064 __func__, idx);
1065 return (0);
1066 }
1067 #if (__FreeBSD_version < 900000)
1068 /*
1069 * RA_RECV: !ip6.forwarding && ip6.accept_rtadv
1070 * RA_SEND: ip6.forwarding
1071 */
1072 return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
1073 (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
1074 #else
1075 /*
1076 * RA_RECV: ND6_IFF_ACCEPT_RTADV
1077 * RA_SEND: ip6.forwarding
1078 */
1079 if (update_ifinfo_nd_flags(ifi) != 0) {
1080 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1081 return (0);
1082 }
1083
1084 return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1085 #endif
1086 }
1087
1088 static void
ra_input(int len,struct nd_router_advert * nra,struct in6_pktinfo * pi,struct sockaddr_in6 * from)1089 ra_input(int len, struct nd_router_advert *nra,
1090 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1091 {
1092 struct rainfo *rai;
1093 struct ifinfo *ifi;
1094 char ntopbuf[INET6_ADDRSTRLEN];
1095 char ifnamebuf[IFNAMSIZ];
1096 union nd_opt ndopts;
1097 const char *on_off[] = {"OFF", "ON"};
1098 uint32_t reachabletime, retranstimer, mtu;
1099 int inconsistent = 0;
1100 int error;
1101
1102 syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1103 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1104 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1105
1106 /* ND option check */
1107 memset(&ndopts, 0, sizeof(ndopts));
1108 TAILQ_INIT(&ndopts.opt_list);
1109 error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1110 len - sizeof(struct nd_router_advert), &ndopts,
1111 NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1112 NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1113 if (error) {
1114 syslog(LOG_INFO,
1115 "<%s> ND option check failed for an RA from %s on %s",
1116 __func__,
1117 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1118 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1119 ifnamebuf));
1120 return;
1121 }
1122
1123 /*
1124 * RA consistency check according to RFC 4861 6.2.7
1125 */
1126 ifi = if_indextoifinfo(pi->ipi6_ifindex);
1127 if (ifi->ifi_rainfo == NULL) {
1128 syslog(LOG_INFO,
1129 "<%s> received RA from %s on non-advertising"
1130 " interface(%s)",
1131 __func__,
1132 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1133 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1134 ifnamebuf));
1135 goto done;
1136 }
1137 rai = ifi->ifi_rainfo;
1138 ifi->ifi_rainput++;
1139 syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1140 ifi->ifi_rainput);
1141
1142 /* Cur Hop Limit value */
1143 if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1144 nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1145 syslog(LOG_NOTICE,
1146 "CurHopLimit inconsistent on %s:"
1147 " %d from %s, %d from us",
1148 ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1149 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1150 sizeof(ntopbuf)), rai->rai_hoplimit);
1151 inconsistent++;
1152 }
1153 /* M flag */
1154 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1155 rai->rai_managedflg) {
1156 syslog(LOG_NOTICE,
1157 "M flag inconsistent on %s:"
1158 " %s from %s, %s from us",
1159 ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1160 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1161 sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1162 inconsistent++;
1163 }
1164 /* O flag */
1165 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1166 rai->rai_otherflg) {
1167 syslog(LOG_NOTICE,
1168 "O flag inconsistent on %s:"
1169 " %s from %s, %s from us",
1170 ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1171 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1172 sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1173 inconsistent++;
1174 }
1175 /* Reachable Time */
1176 reachabletime = ntohl(nra->nd_ra_reachable);
1177 if (reachabletime && rai->rai_reachabletime &&
1178 reachabletime != rai->rai_reachabletime) {
1179 syslog(LOG_NOTICE,
1180 "ReachableTime inconsistent on %s:"
1181 " %d from %s, %d from us",
1182 ifi->ifi_ifname, reachabletime,
1183 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1184 sizeof(ntopbuf)), rai->rai_reachabletime);
1185 inconsistent++;
1186 }
1187 /* Retrans Timer */
1188 retranstimer = ntohl(nra->nd_ra_retransmit);
1189 if (retranstimer && rai->rai_retranstimer &&
1190 retranstimer != rai->rai_retranstimer) {
1191 syslog(LOG_NOTICE,
1192 "RetranceTimer inconsistent on %s:"
1193 " %d from %s, %d from us",
1194 ifi->ifi_ifname, retranstimer,
1195 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1196 sizeof(ntopbuf)), rai->rai_retranstimer);
1197 inconsistent++;
1198 }
1199 /* Values in the MTU options */
1200 if (ndopts.opt_mtu) {
1201 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1202 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1203 syslog(LOG_NOTICE,
1204 "MTU option value inconsistent on %s:"
1205 " %d from %s, %d from us",
1206 ifi->ifi_ifname, mtu,
1207 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1208 sizeof(ntopbuf)), rai->rai_linkmtu);
1209 inconsistent++;
1210 }
1211 }
1212 /* Preferred and Valid Lifetimes for prefixes */
1213 {
1214 struct nd_optlist *nol;
1215
1216 if (ndopts.opt_pi)
1217 if (prefix_check(ndopts.opt_pi, rai, from))
1218 inconsistent++;
1219
1220 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1221 if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1222 rai, from))
1223 inconsistent++;
1224 }
1225
1226 if (inconsistent)
1227 ifi->ifi_rainconsistent++;
1228
1229 done:
1230 free_ndopts(&ndopts);
1231 return;
1232 }
1233
1234 static uint32_t
udiff(uint32_t u,uint32_t v)1235 udiff(uint32_t u, uint32_t v)
1236 {
1237 return (u >= v ? u - v : v - u);
1238 }
1239
1240 /* return a non-zero value if the received prefix is inconsitent with ours */
1241 static int
prefix_check(struct nd_opt_prefix_info * pinfo,struct rainfo * rai,struct sockaddr_in6 * from)1242 prefix_check(struct nd_opt_prefix_info *pinfo,
1243 struct rainfo *rai, struct sockaddr_in6 *from)
1244 {
1245 struct ifinfo *ifi;
1246 uint32_t preferred_time, valid_time;
1247 struct prefix *pfx;
1248 int inconsistent = 0;
1249 char ntopbuf[INET6_ADDRSTRLEN];
1250 char prefixbuf[INET6_ADDRSTRLEN];
1251 struct timeval now;
1252
1253 #if 0 /* impossible */
1254 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1255 return (0);
1256 #endif
1257 ifi = rai->rai_ifinfo;
1258 /*
1259 * log if the adveritsed prefix has link-local scope(sanity check?)
1260 */
1261 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1262 syslog(LOG_INFO,
1263 "<%s> link-local prefix %s/%d is advertised "
1264 "from %s on %s",
1265 __func__,
1266 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1267 sizeof(prefixbuf)),
1268 pinfo->nd_opt_pi_prefix_len,
1269 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1270 sizeof(ntopbuf)), ifi->ifi_ifname);
1271
1272 if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1273 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1274 syslog(LOG_INFO,
1275 "<%s> prefix %s/%d from %s on %s is not in our list",
1276 __func__,
1277 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1278 sizeof(prefixbuf)),
1279 pinfo->nd_opt_pi_prefix_len,
1280 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1281 sizeof(ntopbuf)), ifi->ifi_ifname);
1282 return (0);
1283 }
1284
1285 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1286 if (pfx->pfx_pltimeexpire) {
1287 /*
1288 * The lifetime is decremented in real time, so we should
1289 * compare the expiration time.
1290 * (RFC 2461 Section 6.2.7.)
1291 * XXX: can we really expect that all routers on the link
1292 * have synchronized clocks?
1293 */
1294 gettimeofday(&now, NULL);
1295 preferred_time += now.tv_sec;
1296
1297 if (!pfx->pfx_timer && rai->rai_clockskew &&
1298 udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1299 syslog(LOG_INFO,
1300 "<%s> preferred lifetime for %s/%d"
1301 " (decr. in real time) inconsistent on %s:"
1302 " %" PRIu32 " from %s, %" PRIu32 " 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_pltimeexpire);
1310 inconsistent++;
1311 }
1312 } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1313 syslog(LOG_INFO,
1314 "<%s> preferred lifetime for %s/%d"
1315 " inconsistent on %s:"
1316 " %d from %s, %d from us",
1317 __func__,
1318 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1319 sizeof(prefixbuf)),
1320 pinfo->nd_opt_pi_prefix_len,
1321 ifi->ifi_ifname, preferred_time,
1322 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1323 sizeof(ntopbuf)), pfx->pfx_preflifetime);
1324
1325 valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1326 if (pfx->pfx_vltimeexpire) {
1327 gettimeofday(&now, NULL);
1328 valid_time += now.tv_sec;
1329
1330 if (!pfx->pfx_timer && rai->rai_clockskew &&
1331 udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1332 syslog(LOG_INFO,
1333 "<%s> valid lifetime for %s/%d"
1334 " (decr. in real time) inconsistent on %s:"
1335 " %d from %s, %" PRIu32 " 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, preferred_time,
1341 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1342 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1343 inconsistent++;
1344 }
1345 } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1346 syslog(LOG_INFO,
1347 "<%s> valid lifetime for %s/%d"
1348 " inconsistent on %s:"
1349 " %d from %s, %d from us",
1350 __func__,
1351 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1352 sizeof(prefixbuf)),
1353 pinfo->nd_opt_pi_prefix_len,
1354 ifi->ifi_ifname, valid_time,
1355 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1356 sizeof(ntopbuf)), pfx->pfx_validlifetime);
1357 inconsistent++;
1358 }
1359
1360 return (inconsistent);
1361 }
1362
1363 struct prefix *
find_prefix(struct rainfo * rai,struct in6_addr * prefix,int plen)1364 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1365 {
1366 struct prefix *pfx;
1367 int bytelen, bitlen;
1368 char bitmask;
1369
1370 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1371 if (plen != pfx->pfx_prefixlen)
1372 continue;
1373
1374 bytelen = plen / 8;
1375 bitlen = plen % 8;
1376 bitmask = 0xff << (8 - bitlen);
1377
1378 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1379 continue;
1380
1381 if (bitlen == 0 ||
1382 ((prefix->s6_addr[bytelen] & bitmask) ==
1383 (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1384 return (pfx);
1385 }
1386 }
1387
1388 return (NULL);
1389 }
1390
1391 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1392 int
prefix_match(struct in6_addr * p0,int plen0,struct in6_addr * p1,int plen1)1393 prefix_match(struct in6_addr *p0, int plen0,
1394 struct in6_addr *p1, int plen1)
1395 {
1396 int bytelen, bitlen;
1397 char bitmask;
1398
1399 if (plen0 < plen1)
1400 return (0);
1401
1402 bytelen = plen1 / 8;
1403 bitlen = plen1 % 8;
1404 bitmask = 0xff << (8 - bitlen);
1405
1406 if (memcmp((void *)p0, (void *)p1, bytelen))
1407 return (0);
1408
1409 if (bitlen == 0 ||
1410 ((p0->s6_addr[bytelen] & bitmask) ==
1411 (p1->s6_addr[bytelen] & bitmask))) {
1412 return (1);
1413 }
1414
1415 return (0);
1416 }
1417
1418 static int
nd6_options(struct nd_opt_hdr * hdr,int limit,union nd_opt * ndopts,uint32_t optflags)1419 nd6_options(struct nd_opt_hdr *hdr, int limit,
1420 union nd_opt *ndopts, uint32_t optflags)
1421 {
1422 int optlen = 0;
1423
1424 for (; limit > 0; limit -= optlen) {
1425 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1426 syslog(LOG_INFO, "<%s> short option header", __func__);
1427 goto bad;
1428 }
1429
1430 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1431 if (hdr->nd_opt_len == 0) {
1432 syslog(LOG_INFO,
1433 "<%s> bad ND option length(0) (type = %d)",
1434 __func__, hdr->nd_opt_type);
1435 goto bad;
1436 }
1437 optlen = hdr->nd_opt_len << 3;
1438 if (optlen > limit) {
1439 syslog(LOG_INFO, "<%s> short option", __func__);
1440 goto bad;
1441 }
1442
1443 if (hdr->nd_opt_type > ND_OPT_MTU &&
1444 hdr->nd_opt_type != ND_OPT_RDNSS &&
1445 hdr->nd_opt_type != ND_OPT_DNSSL) {
1446 syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1447 __func__, hdr->nd_opt_type);
1448 continue;
1449 }
1450
1451 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1452 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1453 __func__, hdr->nd_opt_type);
1454 continue;
1455 }
1456
1457 /*
1458 * Option length check. Do it here for all fixed-length
1459 * options.
1460 */
1461 switch (hdr->nd_opt_type) {
1462 case ND_OPT_MTU:
1463 if (optlen == sizeof(struct nd_opt_mtu))
1464 break;
1465 goto skip;
1466 case ND_OPT_RDNSS:
1467 if (optlen >= 24 &&
1468 (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1469 break;
1470 goto skip;
1471 case ND_OPT_DNSSL:
1472 if (optlen >= 16 &&
1473 (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1474 break;
1475 goto skip;
1476 case ND_OPT_PREFIX_INFORMATION:
1477 if (optlen == sizeof(struct nd_opt_prefix_info))
1478 break;
1479 skip:
1480 syslog(LOG_INFO, "<%s> invalid option length",
1481 __func__);
1482 continue;
1483 }
1484
1485 switch (hdr->nd_opt_type) {
1486 case ND_OPT_TARGET_LINKADDR:
1487 case ND_OPT_REDIRECTED_HEADER:
1488 case ND_OPT_RDNSS:
1489 case ND_OPT_DNSSL:
1490 break; /* we don't care about these options */
1491 case ND_OPT_SOURCE_LINKADDR:
1492 case ND_OPT_MTU:
1493 if (ndopts->opt_array[hdr->nd_opt_type]) {
1494 syslog(LOG_INFO,
1495 "<%s> duplicated ND option (type = %d)",
1496 __func__, hdr->nd_opt_type);
1497 }
1498 ndopts->opt_array[hdr->nd_opt_type] = hdr;
1499 break;
1500 case ND_OPT_PREFIX_INFORMATION:
1501 {
1502 struct nd_optlist *nol;
1503
1504 if (ndopts->opt_pi == 0) {
1505 ndopts->opt_pi =
1506 (struct nd_opt_prefix_info *)hdr;
1507 continue;
1508 }
1509 nol = malloc(sizeof(*nol));
1510 if (nol == NULL) {
1511 syslog(LOG_ERR, "<%s> can't allocate memory",
1512 __func__);
1513 goto bad;
1514 }
1515 nol->nol_opt = hdr;
1516 TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1517
1518 break;
1519 }
1520 default: /* impossible */
1521 break;
1522 }
1523 }
1524
1525 return (0);
1526
1527 bad:
1528 free_ndopts(ndopts);
1529
1530 return (-1);
1531 }
1532
1533 static void
free_ndopts(union nd_opt * ndopts)1534 free_ndopts(union nd_opt *ndopts)
1535 {
1536 struct nd_optlist *nol;
1537
1538 while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1539 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1540 free(nol);
1541 }
1542 }
1543
1544 void
sock_open(struct sockinfo * s)1545 sock_open(struct sockinfo *s)
1546 {
1547 struct icmp6_filter filt;
1548 int on;
1549 /* XXX: should be max MTU attached to the node */
1550 static char answer[1500];
1551
1552 syslog(LOG_DEBUG, "<%s> enter", __func__);
1553
1554 if (s == NULL) {
1555 syslog(LOG_ERR, "<%s> internal error", __func__);
1556 exit(1);
1557 }
1558 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1559 CMSG_SPACE(sizeof(int));
1560 rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1561 if (rcvcmsgbuf == NULL) {
1562 syslog(LOG_ERR, "<%s> not enough core", __func__);
1563 exit(1);
1564 }
1565
1566 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1567 CMSG_SPACE(sizeof(int));
1568 sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1569 if (sndcmsgbuf == NULL) {
1570 syslog(LOG_ERR, "<%s> not enough core", __func__);
1571 exit(1);
1572 }
1573
1574 if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1575 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1576 exit(1);
1577 }
1578 /* specify to tell receiving interface */
1579 on = 1;
1580 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1581 sizeof(on)) < 0) {
1582 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1583 strerror(errno));
1584 exit(1);
1585 }
1586 on = 1;
1587 /* specify to tell value of hoplimit field of received IP6 hdr */
1588 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1589 sizeof(on)) < 0) {
1590 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1591 strerror(errno));
1592 exit(1);
1593 }
1594 ICMP6_FILTER_SETBLOCKALL(&filt);
1595 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1596 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1597 if (mcastif != NULL)
1598 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1599
1600 if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1601 sizeof(filt)) < 0) {
1602 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1603 __func__, strerror(errno));
1604 exit(1);
1605 }
1606
1607 /* initialize msghdr for receiving packets */
1608 rcviov[0].iov_base = (caddr_t)answer;
1609 rcviov[0].iov_len = sizeof(answer);
1610 rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1611 rcvmhdr.msg_namelen = sizeof(rcvfrom);
1612 rcvmhdr.msg_iov = rcviov;
1613 rcvmhdr.msg_iovlen = 1;
1614 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1615 rcvmhdr.msg_controllen = rcvcmsgbuflen;
1616
1617 /* initialize msghdr for sending packets */
1618 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1619 sndmhdr.msg_iov = sndiov;
1620 sndmhdr.msg_iovlen = 1;
1621 sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1622 sndmhdr.msg_controllen = sndcmsgbuflen;
1623
1624 return;
1625 }
1626
1627 /* open a routing socket to watch the routing table */
1628 static void
rtsock_open(struct sockinfo * s)1629 rtsock_open(struct sockinfo *s)
1630 {
1631 if (s == NULL) {
1632 syslog(LOG_ERR, "<%s> internal error", __func__);
1633 exit(1);
1634 }
1635 if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1636 syslog(LOG_ERR,
1637 "<%s> socket: %s", __func__, strerror(errno));
1638 exit(1);
1639 }
1640 }
1641
1642 struct ifinfo *
if_indextoifinfo(int idx)1643 if_indextoifinfo(int idx)
1644 {
1645 struct ifinfo *ifi;
1646 char *name, name0[IFNAMSIZ];
1647
1648 /* Check if the interface has a valid name or not. */
1649 if (if_indextoname(idx, name0) == NULL)
1650 return (NULL);
1651
1652 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1653 if (ifi->ifi_ifindex == idx)
1654 return (ifi);
1655 }
1656
1657 if (ifi != NULL)
1658 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1659 __func__, idx);
1660 else
1661 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1662 __func__, idx);
1663
1664 return (NULL); /* search failed */
1665 }
1666
1667 void
ra_output(struct ifinfo * ifi)1668 ra_output(struct ifinfo *ifi)
1669 {
1670 int i;
1671 struct cmsghdr *cm;
1672 struct in6_pktinfo *pi;
1673 struct soliciter *sol;
1674 struct rainfo *rai;
1675
1676 switch (ifi->ifi_state) {
1677 case IFI_STATE_CONFIGURED:
1678 rai = ifi->ifi_rainfo;
1679 break;
1680 case IFI_STATE_TRANSITIVE:
1681 rai = ifi->ifi_rainfo_trans;
1682 break;
1683 case IFI_STATE_UNCONFIGURED:
1684 syslog(LOG_DEBUG, "<%s> %s is unconfigured. "
1685 "Skip sending RAs.",
1686 __func__, ifi->ifi_ifname);
1687 return;
1688 default:
1689 rai = NULL;
1690 }
1691 if (rai == NULL) {
1692 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1693 "Skip sending RAs.",
1694 __func__, ifi->ifi_ifname);
1695 return;
1696 }
1697 if (!(ifi->ifi_flags & IFF_UP)) {
1698 syslog(LOG_DEBUG, "<%s> %s is not up. "
1699 "Skip sending RAs.",
1700 __func__, ifi->ifi_ifname);
1701 return;
1702 }
1703 /*
1704 * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1705 *
1706 * (lifetime == 0) = output
1707 * (lifetime != 0 && (check_accept_rtadv()) = no output
1708 *
1709 * Basically, hosts MUST NOT send Router Advertisement
1710 * messages at any time (RFC 4861, Section 6.2.3). However, it
1711 * would sometimes be useful to allow hosts to advertise some
1712 * parameters such as prefix information and link MTU. Thus,
1713 * we allow hosts to invoke rtadvd only when router lifetime
1714 * (on every advertising interface) is explicitly set
1715 * zero. (see also the above section)
1716 */
1717 syslog(LOG_DEBUG,
1718 "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1719 "on %s", __func__,
1720 rai->rai_lifetime,
1721 check_accept_rtadv(ifi->ifi_ifindex),
1722 getinet6sysctl(IPV6CTL_FORWARDING),
1723 ifi->ifi_ifname);
1724
1725 if (rai->rai_lifetime != 0) {
1726 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1727 syslog(LOG_ERR,
1728 "non-zero lifetime RA "
1729 "but net.inet6.ip6.forwarding=0. "
1730 "Ignored.");
1731 return;
1732 }
1733 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1734 syslog(LOG_ERR,
1735 "non-zero lifetime RA "
1736 "on RA receiving interface %s."
1737 " Ignored.", ifi->ifi_ifname);
1738 return;
1739 }
1740 }
1741
1742 make_packet(rai); /* XXX: inefficient */
1743
1744 sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1745 sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1746 sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1747
1748 cm = CMSG_FIRSTHDR(&sndmhdr);
1749 /* specify the outgoing interface */
1750 cm->cmsg_level = IPPROTO_IPV6;
1751 cm->cmsg_type = IPV6_PKTINFO;
1752 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1753 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1754 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
1755 pi->ipi6_ifindex = ifi->ifi_ifindex;
1756
1757 /* specify the hop limit of the packet */
1758 {
1759 int hoplimit = 255;
1760
1761 cm = CMSG_NXTHDR(&sndmhdr, cm);
1762 cm->cmsg_level = IPPROTO_IPV6;
1763 cm->cmsg_type = IPV6_HOPLIMIT;
1764 cm->cmsg_len = CMSG_LEN(sizeof(int));
1765 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1766 }
1767
1768 syslog(LOG_DEBUG,
1769 "<%s> send RA on %s, # of RS waitings = %d",
1770 __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1771
1772 i = sendmsg(sock.si_fd, &sndmhdr, 0);
1773
1774 if (i < 0 || (size_t)i != rai->rai_ra_datalen) {
1775 if (i < 0) {
1776 syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1777 __func__, ifi->ifi_ifname,
1778 strerror(errno));
1779 }
1780 }
1781
1782 /*
1783 * unicast advertisements
1784 * XXX commented out. reason: though spec does not forbit it, unicast
1785 * advert does not really help
1786 */
1787 while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1788 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1789 free(sol);
1790 }
1791
1792 /* update timestamp */
1793 gettimeofday(&ifi->ifi_ra_lastsent, NULL);
1794
1795 /* update counter */
1796 ifi->ifi_rs_waitcount = 0;
1797 ifi->ifi_raoutput++;
1798
1799 switch (ifi->ifi_state) {
1800 case IFI_STATE_CONFIGURED:
1801 if (ifi->ifi_burstcount > 0)
1802 ifi->ifi_burstcount--;
1803 break;
1804 case IFI_STATE_TRANSITIVE:
1805 ifi->ifi_burstcount--;
1806 if (ifi->ifi_burstcount == 0) {
1807 if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1808 /* Inital burst finished. */
1809 if (ifi->ifi_rainfo_trans != NULL)
1810 ifi->ifi_rainfo_trans = NULL;
1811 }
1812
1813 /* Remove burst RA information */
1814 if (ifi->ifi_rainfo_trans != NULL) {
1815 rm_rainfo(ifi->ifi_rainfo_trans);
1816 ifi->ifi_rainfo_trans = NULL;
1817 }
1818
1819 if (ifi->ifi_rainfo != NULL) {
1820 /*
1821 * TRANSITIVE -> CONFIGURED
1822 *
1823 * After initial burst or transition from
1824 * one configuration to another,
1825 * ifi_rainfo always points to the next RA
1826 * information.
1827 */
1828 ifi->ifi_state = IFI_STATE_CONFIGURED;
1829 syslog(LOG_DEBUG,
1830 "<%s> ifname=%s marked as "
1831 "CONFIGURED.", __func__,
1832 ifi->ifi_ifname);
1833 } else {
1834 /*
1835 * TRANSITIVE -> UNCONFIGURED
1836 *
1837 * If ifi_rainfo points to NULL, this
1838 * interface is shutting down.
1839 *
1840 */
1841 int error;
1842
1843 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1844 syslog(LOG_DEBUG,
1845 "<%s> ifname=%s marked as "
1846 "UNCONFIGURED.", __func__,
1847 ifi->ifi_ifname);
1848 error = sock_mc_leave(&sock,
1849 ifi->ifi_ifindex);
1850 if (error)
1851 exit(1);
1852 }
1853 }
1854 break;
1855 }
1856 }
1857
1858 /* process RA timer */
1859 struct rtadvd_timer *
ra_timeout(void * arg)1860 ra_timeout(void *arg)
1861 {
1862 struct ifinfo *ifi;
1863
1864 ifi = (struct ifinfo *)arg;
1865 syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1866 __func__, ifi->ifi_ifname);
1867
1868 ra_output(ifi);
1869
1870 return (ifi->ifi_ra_timer);
1871 }
1872
1873 /* update RA timer */
1874 void
ra_timer_update(void * arg,struct timeval * tm)1875 ra_timer_update(void *arg, struct timeval *tm)
1876 {
1877 uint16_t interval;
1878 struct rainfo *rai;
1879 struct ifinfo *ifi;
1880
1881 ifi = (struct ifinfo *)arg;
1882 rai = ifi->ifi_rainfo;
1883 interval = 0;
1884
1885 switch (ifi->ifi_state) {
1886 case IFI_STATE_UNCONFIGURED:
1887 return;
1888 break;
1889 case IFI_STATE_CONFIGURED:
1890 /*
1891 * Whenever a multicast advertisement is sent from
1892 * an interface, the timer is reset to a
1893 * uniformly-distributed random value between the
1894 * interface's configured MinRtrAdvInterval and
1895 * MaxRtrAdvInterval (RFC4861 6.2.4).
1896 */
1897 interval = rai->rai_mininterval;
1898 #ifdef HAVE_ARC4RANDOM
1899 interval += arc4random_uniform(rai->rai_maxinterval -
1900 rai->rai_mininterval);
1901 #else
1902 interval += random() % (rai->rai_maxinterval -
1903 rai->rai_mininterval);
1904 #endif
1905 break;
1906 case IFI_STATE_TRANSITIVE:
1907 /*
1908 * For the first few advertisements (up to
1909 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1910 * interval is greater than
1911 * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1912 * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC
1913 * 4861 6.2.4)
1914 *
1915 * In such cases, the router SHOULD transmit one or more
1916 * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1917 * multicast Router Advertisements on the interface with a
1918 * Router Lifetime field of zero. (RFC 4861 6.2.5)
1919 */
1920 interval = ifi->ifi_burstinterval;
1921 break;
1922 }
1923
1924 tm->tv_sec = interval;
1925 tm->tv_usec = 0;
1926
1927 syslog(LOG_DEBUG,
1928 "<%s> RA timer on %s is set to %ld:%ld",
1929 __func__, ifi->ifi_ifname,
1930 (long int)tm->tv_sec, (long int)tm->tv_usec);
1931
1932 return;
1933 }
1934