1 /* $FreeBSD$ */
2 /* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */
3
4 /*-
5 * SPDX-License-Identifier: BSD-3-Clause
6 *
7 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
8 * Copyright (C) 2011 Hiroki Sato <[email protected]>
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the project nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/param.h>
37 #include <sys/ioctl.h>
38 #include <sys/socket.h>
39 #include <sys/uio.h>
40 #include <sys/queue.h>
41 #include <sys/stat.h>
42 #include <sys/sysctl.h>
43
44 #include <net/if.h>
45 #include <net/if_types.h>
46 #include <net/if_media.h>
47 #include <net/if_dl.h>
48 #include <net/route.h>
49 #include <netinet/in.h>
50 #include <netinet/ip6.h>
51 #include <netinet6/ip6_var.h>
52 #include <netinet/icmp6.h>
53
54 #include <arpa/inet.h>
55
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 timespec *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 pfh = pidfile_open(pidfilename, 0600, &otherpid);
247 if (pfh == NULL) {
248 if (errno == EEXIST)
249 errx(1, "%s already running, pid: %d",
250 getprogname(), otherpid);
251 syslog(LOG_ERR,
252 "failed to open the pid file %s, run anyway.",
253 pidfilename);
254 }
255 if (!fflag)
256 daemon(1, 0);
257
258 sock_open(&sock);
259
260 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
261 for (i = 0; i < argc; i++)
262 update_persist_ifinfo(&ifilist, argv[i]);
263
264 csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
265 if (ctrlsock.si_fd == -1) {
266 syslog(LOG_ERR, "cannot open control socket: %s",
267 strerror(errno));
268 exit(1);
269 }
270
271 /* record the current PID */
272 pid = getpid();
273 pidfile_write(pfh);
274
275 set[PFD_RAWSOCK].fd = sock.si_fd;
276 set[PFD_RAWSOCK].events = POLLIN;
277 if (sflag == 0) {
278 rtsock_open(&rtsock);
279 set[PFD_RTSOCK].fd = rtsock.si_fd;
280 set[PFD_RTSOCK].events = POLLIN;
281 } else
282 set[PFD_RTSOCK].fd = -1;
283 set[PFD_CSOCK].fd = ctrlsock.si_fd;
284 set[PFD_CSOCK].events = POLLIN;
285 signal(SIGTERM, set_do_shutdown);
286 signal(SIGINT, set_do_shutdown);
287 signal(SIGHUP, set_do_reload);
288
289 error = csock_listen(&ctrlsock);
290 if (error) {
291 syslog(LOG_ERR, "cannot listen control socket: %s",
292 strerror(errno));
293 exit(1);
294 }
295
296 /* load configuration file */
297 set_do_reload(0);
298
299 while (1) {
300 if (is_do_shutdown())
301 rtadvd_shutdown();
302
303 if (is_do_reload()) {
304 loadconfig_ifname(reload_ifname());
305 if (reload_ifname() == NULL)
306 syslog(LOG_INFO,
307 "configuration file reloaded.");
308 else
309 syslog(LOG_INFO,
310 "configuration file for %s reloaded.",
311 reload_ifname());
312 reset_do_reload();
313 }
314
315 /* timeout handler update for active interfaces */
316 rtadvd_update_timeout_handler();
317
318 /* timer expiration check and reset the timer */
319 timeout = rtadvd_check_timer();
320
321 if (timeout != NULL) {
322 syslog(LOG_DEBUG,
323 "<%s> set timer to %ld:%ld. waiting for "
324 "inputs or timeout", __func__,
325 (long int)timeout->tv_sec,
326 (long int)timeout->tv_nsec / 1000);
327 } else {
328 syslog(LOG_DEBUG,
329 "<%s> there's no timer. waiting for inputs",
330 __func__);
331 }
332 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
333 timeout ? (timeout->tv_sec * 1000 +
334 timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
335
336 /* EINTR would occur if a signal was delivered */
337 if (errno != EINTR)
338 syslog(LOG_ERR, "poll() failed: %s",
339 strerror(errno));
340 continue;
341 }
342 if (i == 0) /* timeout */
343 continue;
344 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
345 rtmsg_input(&rtsock);
346
347 if (set[PFD_RAWSOCK].revents & POLLIN)
348 rtadvd_input(&sock);
349
350 if (set[PFD_CSOCK].revents & POLLIN) {
351 int fd;
352
353 fd = csock_accept(&ctrlsock);
354 if (fd == -1)
355 syslog(LOG_ERR,
356 "cannot accept() control socket: %s",
357 strerror(errno));
358 else {
359 cm_handler_server(fd);
360 close(fd);
361 }
362 }
363 }
364 exit(0); /* NOTREACHED */
365 }
366
367 static void
rtadvd_shutdown(void)368 rtadvd_shutdown(void)
369 {
370 struct ifinfo *ifi;
371 struct rainfo *rai;
372 struct rdnss *rdn;
373 struct dnssl *dns;
374
375 if (wait_shutdown) {
376 syslog(LOG_INFO,
377 "waiting expiration of the all RA timers.");
378
379 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
380 /*
381 * Ignore !IFF_UP interfaces in waiting for shutdown.
382 */
383 if (!(ifi->ifi_flags & IFF_UP) &&
384 ifi->ifi_ra_timer != NULL) {
385 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
386 rtadvd_remove_timer(ifi->ifi_ra_timer);
387 ifi->ifi_ra_timer = NULL;
388 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
389 "Timer removed and marked as UNCONFIGURED.",
390 __func__, ifi->ifi_ifname,
391 ifi->ifi_ifindex);
392 }
393 }
394 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
395 if (ifi->ifi_ra_timer != NULL)
396 break;
397 }
398 if (ifi == NULL) {
399 syslog(LOG_NOTICE, "gracefully terminated.");
400 exit(0);
401 }
402
403 sleep(1);
404 return;
405 }
406
407 syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
408 __func__);
409
410 wait_shutdown = 1;
411
412 TAILQ_FOREACH(rai, &railist, rai_next) {
413 rai->rai_lifetime = 0;
414 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
415 rdn->rd_ltime = 0;
416 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
417 dns->dn_ltime = 0;
418 }
419 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
420 if (!ifi->ifi_persist)
421 continue;
422 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
423 continue;
424 if (ifi->ifi_ra_timer == NULL)
425 continue;
426 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
427 ifi->ifi_ra_lastsent.tv_nsec == 0 &&
428 ifi->ifi_ra_timer != NULL) {
429 /*
430 * When RA configured but never sent,
431 * ignore the IF immediately.
432 */
433 rtadvd_remove_timer(ifi->ifi_ra_timer);
434 ifi->ifi_ra_timer = NULL;
435 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
436 continue;
437 }
438
439 ifi->ifi_state = IFI_STATE_TRANSITIVE;
440
441 /* Mark as the shut-down state. */
442 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
443 ifi->ifi_rainfo = NULL;
444
445 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
446 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
447
448 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
449 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
450 ifi->ifi_ra_timer);
451 }
452 syslog(LOG_NOTICE, "final RA transmission started.");
453
454 pidfile_remove(pfh);
455 csock_close(&ctrlsock);
456 }
457
458 static void
rtmsg_input(struct sockinfo * s)459 rtmsg_input(struct sockinfo *s)
460 {
461 int n, type, ifindex = 0, plen;
462 size_t len;
463 char msg[2048], *next, *lim;
464 char ifname[IFNAMSIZ];
465 struct if_announcemsghdr *ifan;
466 struct rt_msghdr *rtm;
467 struct prefix *pfx;
468 struct rainfo *rai;
469 struct in6_addr *addr;
470 struct ifinfo *ifi;
471 char addrbuf[INET6_ADDRSTRLEN];
472 int prefixchange = 0;
473
474 if (s == NULL) {
475 syslog(LOG_ERR, "<%s> internal error", __func__);
476 exit(1);
477 }
478 n = read(s->si_fd, msg, sizeof(msg));
479 rtm = (struct rt_msghdr *)msg;
480 syslog(LOG_DEBUG, "<%s> received a routing message "
481 "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
482
483 if (n > rtm->rtm_msglen) {
484 /*
485 * This usually won't happen for messages received on
486 * a routing socket.
487 */
488 syslog(LOG_DEBUG,
489 "<%s> received data length is larger than "
490 "1st routing message len. multiple messages? "
491 "read %d bytes, but 1st msg len = %d",
492 __func__, n, rtm->rtm_msglen);
493 #if 0
494 /* adjust length */
495 n = rtm->rtm_msglen;
496 #endif
497 }
498
499 lim = msg + n;
500 for (next = msg; next < lim; next += len) {
501 int oldifflags;
502
503 next = get_next_msg(next, lim, 0, &len,
504 RTADV_TYPE2BITMASK(RTM_ADD) |
505 RTADV_TYPE2BITMASK(RTM_DELETE) |
506 RTADV_TYPE2BITMASK(RTM_NEWADDR) |
507 RTADV_TYPE2BITMASK(RTM_DELADDR) |
508 RTADV_TYPE2BITMASK(RTM_IFINFO) |
509 RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
510 if (len == 0)
511 break;
512 type = ((struct rt_msghdr *)next)->rtm_type;
513 switch (type) {
514 case RTM_ADD:
515 case RTM_DELETE:
516 ifindex = get_rtm_ifindex(next);
517 break;
518 case RTM_NEWADDR:
519 case RTM_DELADDR:
520 ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
521 break;
522 case RTM_IFINFO:
523 ifindex = (int)((struct if_msghdr *)next)->ifm_index;
524 break;
525 case RTM_IFANNOUNCE:
526 ifan = (struct if_announcemsghdr *)next;
527 switch (ifan->ifan_what) {
528 case IFAN_ARRIVAL:
529 case IFAN_DEPARTURE:
530 break;
531 default:
532 syslog(LOG_DEBUG,
533 "<%s:%d> unknown ifan msg (ifan_what=%d)",
534 __func__, __LINE__, ifan->ifan_what);
535 continue;
536 }
537
538 syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
539 __func__, ifan->ifan_index, ifan->ifan_what);
540 switch (ifan->ifan_what) {
541 case IFAN_ARRIVAL:
542 syslog(LOG_NOTICE,
543 "interface added (idx=%d)",
544 ifan->ifan_index);
545 update_ifinfo(&ifilist, ifan->ifan_index);
546 loadconfig_index(ifan->ifan_index);
547 break;
548 case IFAN_DEPARTURE:
549 syslog(LOG_NOTICE,
550 "interface removed (idx=%d)",
551 ifan->ifan_index);
552 rm_ifinfo_index(ifan->ifan_index);
553
554 /* Clear ifi_ifindex */
555 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
556 if (ifi->ifi_ifindex
557 == ifan->ifan_index) {
558 ifi->ifi_ifindex = 0;
559 break;
560 }
561 }
562 update_ifinfo(&ifilist, ifan->ifan_index);
563 break;
564 }
565 continue;
566 default:
567 /* should not reach here */
568 syslog(LOG_DEBUG,
569 "<%s:%d> unknown rtmsg %d on %s",
570 __func__, __LINE__, type,
571 if_indextoname(ifindex, ifname));
572 continue;
573 }
574 ifi = if_indextoifinfo(ifindex);
575 if (ifi == NULL) {
576 syslog(LOG_DEBUG,
577 "<%s> ifinfo not found for idx=%d. Why?",
578 __func__, ifindex);
579 continue;
580 }
581 rai = ifi->ifi_rainfo;
582 if (rai == NULL) {
583 syslog(LOG_DEBUG,
584 "<%s> route changed on "
585 "non advertising interface(%s)",
586 __func__, ifi->ifi_ifname);
587 continue;
588 }
589
590 oldifflags = ifi->ifi_flags;
591 /* init ifflags because it may have changed */
592 update_ifinfo(&ifilist, ifindex);
593
594 switch (type) {
595 case RTM_ADD:
596 if (sflag)
597 break; /* we aren't interested in prefixes */
598
599 addr = get_addr(msg);
600 plen = get_prefixlen(msg);
601 /* sanity check for plen */
602 /* as RFC2373, prefixlen is at least 4 */
603 if (plen < 4 || plen > 127) {
604 syslog(LOG_INFO, "<%s> new interface route's"
605 "plen %d is invalid for a prefix",
606 __func__, plen);
607 break;
608 }
609 pfx = find_prefix(rai, addr, plen);
610 if (pfx) {
611 if (pfx->pfx_timer) {
612 /*
613 * If the prefix has been invalidated,
614 * make it available again.
615 */
616 update_prefix(pfx);
617 prefixchange = 1;
618 } else
619 syslog(LOG_DEBUG,
620 "<%s> new prefix(%s/%d) "
621 "added on %s, "
622 "but it was already in list",
623 __func__,
624 inet_ntop(AF_INET6, addr,
625 (char *)addrbuf,
626 sizeof(addrbuf)),
627 plen, ifi->ifi_ifname);
628 break;
629 }
630 make_prefix(rai, ifindex, addr, plen);
631 prefixchange = 1;
632 break;
633 case RTM_DELETE:
634 if (sflag)
635 break;
636
637 addr = get_addr(msg);
638 plen = get_prefixlen(msg);
639 /* sanity check for plen */
640 /* as RFC2373, prefixlen is at least 4 */
641 if (plen < 4 || plen > 127) {
642 syslog(LOG_INFO,
643 "<%s> deleted interface route's "
644 "plen %d is invalid for a prefix",
645 __func__, plen);
646 break;
647 }
648 pfx = find_prefix(rai, addr, plen);
649 if (pfx == NULL) {
650 syslog(LOG_DEBUG,
651 "<%s> prefix(%s/%d) was deleted on %s, "
652 "but it was not in list",
653 __func__, inet_ntop(AF_INET6, addr,
654 (char *)addrbuf, sizeof(addrbuf)),
655 plen, ifi->ifi_ifname);
656 break;
657 }
658 invalidate_prefix(pfx);
659 prefixchange = 1;
660 break;
661 case RTM_NEWADDR:
662 case RTM_DELADDR:
663 case RTM_IFINFO:
664 break;
665 default:
666 /* should not reach here */
667 syslog(LOG_DEBUG,
668 "<%s:%d> unknown rtmsg %d on %s",
669 __func__, __LINE__, type,
670 if_indextoname(ifindex, ifname));
671 return;
672 }
673
674 /* check if an interface flag is changed */
675 if ((oldifflags & IFF_UP) && /* UP to DOWN */
676 !(ifi->ifi_flags & IFF_UP)) {
677 syslog(LOG_NOTICE,
678 "<interface %s becomes down. stop timer.",
679 ifi->ifi_ifname);
680 rtadvd_remove_timer(ifi->ifi_ra_timer);
681 ifi->ifi_ra_timer = NULL;
682 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
683 (ifi->ifi_flags & IFF_UP)) {
684 syslog(LOG_NOTICE,
685 "interface %s becomes up. restart timer.",
686 ifi->ifi_ifname);
687
688 ifi->ifi_state = IFI_STATE_TRANSITIVE;
689 ifi->ifi_burstcount =
690 MAX_INITIAL_RTR_ADVERTISEMENTS;
691 ifi->ifi_burstinterval =
692 MAX_INITIAL_RTR_ADVERT_INTERVAL;
693
694 ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
695 ra_timer_update, ifi, ifi);
696 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
697 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
698 ifi->ifi_ra_timer);
699 } else if (prefixchange &&
700 (ifi->ifi_flags & IFF_UP)) {
701 /*
702 * An advertised prefix has been added or invalidated.
703 * Will notice the change in a short delay.
704 */
705 set_short_delay(ifi);
706 }
707 }
708
709 return;
710 }
711
712 void
rtadvd_input(struct sockinfo * s)713 rtadvd_input(struct sockinfo *s)
714 {
715 ssize_t i;
716 int *hlimp = NULL;
717 #ifdef OLDRAWSOCKET
718 struct ip6_hdr *ip;
719 #endif
720 struct icmp6_hdr *icp;
721 int ifindex = 0;
722 struct cmsghdr *cm;
723 struct in6_pktinfo *pi = NULL;
724 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
725 struct in6_addr dst = in6addr_any;
726 struct ifinfo *ifi;
727
728 syslog(LOG_DEBUG, "<%s> enter", __func__);
729
730 if (s == NULL) {
731 syslog(LOG_ERR, "<%s> internal error", __func__);
732 exit(1);
733 }
734 /*
735 * Get message. We reset msg_controllen since the field could
736 * be modified if we had received a message before setting
737 * receive options.
738 */
739 rcvmhdr.msg_controllen = rcvcmsgbuflen;
740 if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
741 return;
742
743 /* extract optional information via Advanced API */
744 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
745 cm;
746 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
747 if (cm->cmsg_level == IPPROTO_IPV6 &&
748 cm->cmsg_type == IPV6_PKTINFO &&
749 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
750 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
751 ifindex = pi->ipi6_ifindex;
752 dst = pi->ipi6_addr;
753 }
754 if (cm->cmsg_level == IPPROTO_IPV6 &&
755 cm->cmsg_type == IPV6_HOPLIMIT &&
756 cm->cmsg_len == CMSG_LEN(sizeof(int)))
757 hlimp = (int *)CMSG_DATA(cm);
758 }
759 if (ifindex == 0) {
760 syslog(LOG_ERR, "failed to get receiving interface");
761 return;
762 }
763 if (hlimp == NULL) {
764 syslog(LOG_ERR, "failed to get receiving hop limit");
765 return;
766 }
767
768 /*
769 * If we happen to receive data on an interface which is now gone
770 * or down, just discard the data.
771 */
772 ifi = if_indextoifinfo(pi->ipi6_ifindex);
773 if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
774 syslog(LOG_INFO,
775 "<%s> received data on a disabled interface (%s)",
776 __func__,
777 (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
778 return;
779 }
780
781 #ifdef OLDRAWSOCKET
782 if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
783 syslog(LOG_ERR,
784 "packet size(%d) is too short", i);
785 return;
786 }
787
788 ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
789 icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
790 #else
791 if ((size_t)i < sizeof(struct icmp6_hdr)) {
792 syslog(LOG_ERR, "packet size(%zd) is too short", i);
793 return;
794 }
795
796 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
797 #endif
798
799 switch (icp->icmp6_type) {
800 case ND_ROUTER_SOLICIT:
801 /*
802 * Message verification - RFC 4861 6.1.1
803 * XXX: these checks must be done in the kernel as well,
804 * but we can't completely rely on them.
805 */
806 if (*hlimp != 255) {
807 syslog(LOG_NOTICE,
808 "RS with invalid hop limit(%d) "
809 "received from %s on %s",
810 *hlimp,
811 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
812 sizeof(ntopbuf)),
813 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
814 return;
815 }
816 if (icp->icmp6_code) {
817 syslog(LOG_NOTICE,
818 "RS with invalid ICMP6 code(%d) "
819 "received from %s on %s",
820 icp->icmp6_code,
821 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
822 sizeof(ntopbuf)),
823 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
824 return;
825 }
826 if ((size_t)i < sizeof(struct nd_router_solicit)) {
827 syslog(LOG_NOTICE,
828 "RS from %s on %s does not have enough "
829 "length (len = %zd)",
830 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
831 sizeof(ntopbuf)),
832 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
833 return;
834 }
835 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
836 break;
837 case ND_ROUTER_ADVERT:
838 /*
839 * Message verification - RFC 4861 6.1.2
840 * XXX: there's the same dilemma as above...
841 */
842 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
843 syslog(LOG_NOTICE,
844 "RA with non-linklocal source address "
845 "received from %s on %s",
846 inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
847 ntopbuf, sizeof(ntopbuf)),
848 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
849 return;
850 }
851 if (*hlimp != 255) {
852 syslog(LOG_NOTICE,
853 "RA with invalid hop limit(%d) "
854 "received from %s on %s",
855 *hlimp,
856 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
857 sizeof(ntopbuf)),
858 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
859 return;
860 }
861 if (icp->icmp6_code) {
862 syslog(LOG_NOTICE,
863 "RA with invalid ICMP6 code(%d) "
864 "received from %s on %s",
865 icp->icmp6_code,
866 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
867 sizeof(ntopbuf)),
868 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
869 return;
870 }
871 if ((size_t)i < sizeof(struct nd_router_advert)) {
872 syslog(LOG_NOTICE,
873 "RA from %s on %s does not have enough "
874 "length (len = %zd)",
875 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
876 sizeof(ntopbuf)),
877 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
878 return;
879 }
880 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
881 break;
882 case ICMP6_ROUTER_RENUMBERING:
883 if (mcastif == NULL) {
884 syslog(LOG_ERR, "received a router renumbering "
885 "message, but not allowed to be accepted");
886 break;
887 }
888 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
889 &dst);
890 break;
891 default:
892 /*
893 * Note that this case is POSSIBLE, especially just
894 * after invocation of the daemon. This is because we
895 * could receive message after opening the socket and
896 * before setting ICMP6 type filter(see sock_open()).
897 */
898 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
899 return;
900 }
901
902 return;
903 }
904
905 static void
rs_input(int len,struct nd_router_solicit * rs,struct in6_pktinfo * pi,struct sockaddr_in6 * from)906 rs_input(int len, struct nd_router_solicit *rs,
907 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
908 {
909 char ntopbuf[INET6_ADDRSTRLEN];
910 char ifnamebuf[IFNAMSIZ];
911 union nd_opt ndopts;
912 struct rainfo *rai;
913 struct ifinfo *ifi;
914 struct soliciter *sol;
915
916 syslog(LOG_DEBUG,
917 "<%s> RS received from %s on %s",
918 __func__,
919 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
920 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
921
922 /* ND option check */
923 memset(&ndopts, 0, sizeof(ndopts));
924 TAILQ_INIT(&ndopts.opt_list);
925 if (nd6_options((struct nd_opt_hdr *)(rs + 1),
926 len - sizeof(struct nd_router_solicit),
927 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
928 syslog(LOG_INFO,
929 "<%s> ND option check failed for an RS from %s on %s",
930 __func__,
931 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
932 sizeof(ntopbuf)),
933 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
934 return;
935 }
936
937 /*
938 * If the IP source address is the unspecified address, there
939 * must be no source link-layer address option in the message.
940 * (RFC 4861 6.1.1)
941 */
942 if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
943 ndopts.opt_src_lladdr) {
944 syslog(LOG_INFO,
945 "<%s> RS from unspecified src on %s has a link-layer"
946 " address option",
947 __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
948 goto done;
949 }
950
951 ifi = if_indextoifinfo(pi->ipi6_ifindex);
952 if (ifi == NULL) {
953 syslog(LOG_INFO,
954 "<%s> if (idx=%d) not found. Why?",
955 __func__, pi->ipi6_ifindex);
956 goto done;
957 }
958 rai = ifi->ifi_rainfo;
959 if (rai == NULL) {
960 syslog(LOG_INFO,
961 "<%s> RS received on non advertising interface(%s)",
962 __func__,
963 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
964 goto done;
965 }
966
967 rai->rai_ifinfo->ifi_rsinput++;
968
969 /*
970 * Decide whether to send RA according to the rate-limit
971 * consideration.
972 */
973
974 /* record sockaddr waiting for RA, if possible */
975 sol = (struct soliciter *)malloc(sizeof(*sol));
976 if (sol) {
977 sol->sol_addr = *from;
978 /* XXX RFC 2553 need clarification on flowinfo */
979 sol->sol_addr.sin6_flowinfo = 0;
980 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
981 }
982
983 /*
984 * If there is already a waiting RS packet, don't
985 * update the timer.
986 */
987 if (ifi->ifi_rs_waitcount++)
988 goto done;
989
990 set_short_delay(ifi);
991
992 done:
993 free_ndopts(&ndopts);
994 return;
995 }
996
997 static void
set_short_delay(struct ifinfo * ifi)998 set_short_delay(struct ifinfo *ifi)
999 {
1000 long delay; /* must not be greater than 1000000 */
1001 struct timespec interval, now, min_delay, tm_tmp, *rest;
1002
1003 if (ifi->ifi_ra_timer == NULL)
1004 return;
1005 /*
1006 * Compute a random delay. If the computed value
1007 * corresponds to a time later than the time the next
1008 * multicast RA is scheduled to be sent, ignore the random
1009 * delay and send the advertisement at the
1010 * already-scheduled time. RFC 4861 6.2.6
1011 */
1012 delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1013 interval.tv_sec = 0;
1014 interval.tv_nsec = delay * 1000;
1015 rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1016 if (TS_CMP(rest, &interval, <)) {
1017 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1018 "the rest of the current timer", __func__);
1019 interval = *rest;
1020 }
1021
1022 /*
1023 * If we sent a multicast Router Advertisement within
1024 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1025 * the advertisement to be sent at a time corresponding to
1026 * MIN_DELAY_BETWEEN_RAS plus the random value after the
1027 * previous advertisement was sent.
1028 */
1029 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1030 TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1031 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1032 min_delay.tv_nsec = 0;
1033 if (TS_CMP(&tm_tmp, &min_delay, <)) {
1034 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1035 TS_ADD(&min_delay, &interval, &interval);
1036 }
1037 rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1038 }
1039
1040 static int
check_accept_rtadv(int idx)1041 check_accept_rtadv(int idx)
1042 {
1043 struct ifinfo *ifi;
1044
1045 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1046 if (ifi->ifi_ifindex == idx)
1047 break;
1048 }
1049 if (ifi == NULL) {
1050 syslog(LOG_DEBUG,
1051 "<%s> if (idx=%d) not found. Why?",
1052 __func__, idx);
1053 return (0);
1054 }
1055
1056 /*
1057 * RA_RECV: ND6_IFF_ACCEPT_RTADV
1058 * RA_SEND: ip6.forwarding
1059 */
1060 if (update_ifinfo_nd_flags(ifi) != 0) {
1061 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1062 return (0);
1063 }
1064
1065 return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1066 }
1067
1068 static void
ra_input(int len,struct nd_router_advert * nra,struct in6_pktinfo * pi,struct sockaddr_in6 * from)1069 ra_input(int len, struct nd_router_advert *nra,
1070 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1071 {
1072 struct rainfo *rai;
1073 struct ifinfo *ifi;
1074 char ntopbuf[INET6_ADDRSTRLEN];
1075 char ifnamebuf[IFNAMSIZ];
1076 union nd_opt ndopts;
1077 const char *on_off[] = {"OFF", "ON"};
1078 uint32_t reachabletime, retranstimer, mtu;
1079 int inconsistent = 0;
1080 int error;
1081
1082 syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1083 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1084 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1085
1086 /* ND option check */
1087 memset(&ndopts, 0, sizeof(ndopts));
1088 TAILQ_INIT(&ndopts.opt_list);
1089 error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1090 len - sizeof(struct nd_router_advert), &ndopts,
1091 NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1092 NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1093 if (error) {
1094 syslog(LOG_INFO,
1095 "<%s> ND option check failed for an RA from %s on %s",
1096 __func__,
1097 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1098 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1099 ifnamebuf));
1100 return;
1101 }
1102
1103 /*
1104 * RA consistency check according to RFC 4861 6.2.7
1105 */
1106 ifi = if_indextoifinfo(pi->ipi6_ifindex);
1107 if (ifi->ifi_rainfo == NULL) {
1108 syslog(LOG_INFO,
1109 "<%s> received RA from %s on non-advertising"
1110 " interface(%s)",
1111 __func__,
1112 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1113 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1114 ifnamebuf));
1115 goto done;
1116 }
1117 rai = ifi->ifi_rainfo;
1118 ifi->ifi_rainput++;
1119 syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1120 ifi->ifi_rainput);
1121
1122 /* Cur Hop Limit value */
1123 if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1124 nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1125 syslog(LOG_NOTICE,
1126 "CurHopLimit inconsistent on %s:"
1127 " %d from %s, %d from us",
1128 ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1129 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1130 sizeof(ntopbuf)), rai->rai_hoplimit);
1131 inconsistent++;
1132 }
1133 /* M flag */
1134 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1135 rai->rai_managedflg) {
1136 syslog(LOG_NOTICE,
1137 "M flag inconsistent on %s:"
1138 " %s from %s, %s from us",
1139 ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1140 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1141 sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1142 inconsistent++;
1143 }
1144 /* O flag */
1145 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1146 rai->rai_otherflg) {
1147 syslog(LOG_NOTICE,
1148 "O flag inconsistent on %s:"
1149 " %s from %s, %s from us",
1150 ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1151 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1152 sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1153 inconsistent++;
1154 }
1155 #ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
1156 /* S "IPv6-Only" (Six, Silence-IPv4) flag */
1157 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_IPV6_ONLY) !=
1158 rai->rai_ipv6onlyflg) {
1159 syslog(LOG_NOTICE,
1160 "S flag inconsistent on %s:"
1161 " %s from %s, %s from us",
1162 ifi->ifi_ifname, on_off[!rai->rai_ipv6onlyflg],
1163 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1164 sizeof(ntopbuf)), on_off[rai->rai_ipv6onlyflg]);
1165 inconsistent++;
1166 }
1167 #endif
1168 /* Reachable Time */
1169 reachabletime = ntohl(nra->nd_ra_reachable);
1170 if (reachabletime && rai->rai_reachabletime &&
1171 reachabletime != rai->rai_reachabletime) {
1172 syslog(LOG_NOTICE,
1173 "ReachableTime inconsistent on %s:"
1174 " %d from %s, %d from us",
1175 ifi->ifi_ifname, reachabletime,
1176 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1177 sizeof(ntopbuf)), rai->rai_reachabletime);
1178 inconsistent++;
1179 }
1180 /* Retrans Timer */
1181 retranstimer = ntohl(nra->nd_ra_retransmit);
1182 if (retranstimer && rai->rai_retranstimer &&
1183 retranstimer != rai->rai_retranstimer) {
1184 syslog(LOG_NOTICE,
1185 "RetranceTimer inconsistent on %s:"
1186 " %d from %s, %d from us",
1187 ifi->ifi_ifname, retranstimer,
1188 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1189 sizeof(ntopbuf)), rai->rai_retranstimer);
1190 inconsistent++;
1191 }
1192 /* Values in the MTU options */
1193 if (ndopts.opt_mtu) {
1194 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1195 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1196 syslog(LOG_NOTICE,
1197 "MTU option value inconsistent on %s:"
1198 " %d from %s, %d from us",
1199 ifi->ifi_ifname, mtu,
1200 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1201 sizeof(ntopbuf)), rai->rai_linkmtu);
1202 inconsistent++;
1203 }
1204 }
1205 /* Preferred and Valid Lifetimes for prefixes */
1206 {
1207 struct nd_optlist *nol;
1208
1209 if (ndopts.opt_pi)
1210 if (prefix_check(ndopts.opt_pi, rai, from))
1211 inconsistent++;
1212
1213 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1214 if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1215 rai, from))
1216 inconsistent++;
1217 }
1218
1219 if (inconsistent)
1220 ifi->ifi_rainconsistent++;
1221
1222 done:
1223 free_ndopts(&ndopts);
1224 return;
1225 }
1226
1227 static uint32_t
udiff(uint32_t u,uint32_t v)1228 udiff(uint32_t u, uint32_t v)
1229 {
1230 return (u >= v ? u - v : v - u);
1231 }
1232
1233 /* return a non-zero value if the received prefix is inconsistent with ours */
1234 static int
prefix_check(struct nd_opt_prefix_info * pinfo,struct rainfo * rai,struct sockaddr_in6 * from)1235 prefix_check(struct nd_opt_prefix_info *pinfo,
1236 struct rainfo *rai, struct sockaddr_in6 *from)
1237 {
1238 struct ifinfo *ifi;
1239 uint32_t preferred_time, valid_time;
1240 struct prefix *pfx;
1241 int inconsistent = 0;
1242 char ntopbuf[INET6_ADDRSTRLEN];
1243 char prefixbuf[INET6_ADDRSTRLEN];
1244 struct timespec now;
1245
1246 #if 0 /* impossible */
1247 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1248 return (0);
1249 #endif
1250 ifi = rai->rai_ifinfo;
1251 /*
1252 * log if the adveritsed prefix has link-local scope(sanity check?)
1253 */
1254 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1255 syslog(LOG_INFO,
1256 "<%s> link-local prefix %s/%d is advertised "
1257 "from %s on %s",
1258 __func__,
1259 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1260 sizeof(prefixbuf)),
1261 pinfo->nd_opt_pi_prefix_len,
1262 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1263 sizeof(ntopbuf)), ifi->ifi_ifname);
1264
1265 if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1266 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1267 syslog(LOG_INFO,
1268 "<%s> prefix %s/%d from %s on %s is not in our list",
1269 __func__,
1270 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1271 sizeof(prefixbuf)),
1272 pinfo->nd_opt_pi_prefix_len,
1273 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1274 sizeof(ntopbuf)), ifi->ifi_ifname);
1275 return (0);
1276 }
1277
1278 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1279 if (pfx->pfx_pltimeexpire) {
1280 /*
1281 * The lifetime is decremented in real time, so we should
1282 * compare the expiration time.
1283 * (RFC 2461 Section 6.2.7.)
1284 * XXX: can we really expect that all routers on the link
1285 * have synchronized clocks?
1286 */
1287 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1288 preferred_time += now.tv_sec;
1289
1290 if (!pfx->pfx_timer && rai->rai_clockskew &&
1291 udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1292 syslog(LOG_INFO,
1293 "<%s> preferred lifetime for %s/%d"
1294 " (decr. in real time) inconsistent on %s:"
1295 " %" PRIu32 " from %s, %" PRIu32 " from us",
1296 __func__,
1297 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1298 sizeof(prefixbuf)),
1299 pinfo->nd_opt_pi_prefix_len,
1300 ifi->ifi_ifname, preferred_time,
1301 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1302 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1303 inconsistent++;
1304 }
1305 } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1306 syslog(LOG_INFO,
1307 "<%s> preferred lifetime for %s/%d"
1308 " inconsistent on %s:"
1309 " %d from %s, %d from us",
1310 __func__,
1311 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1312 sizeof(prefixbuf)),
1313 pinfo->nd_opt_pi_prefix_len,
1314 ifi->ifi_ifname, preferred_time,
1315 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1316 sizeof(ntopbuf)), pfx->pfx_preflifetime);
1317
1318 valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1319 if (pfx->pfx_vltimeexpire) {
1320 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1321 valid_time += now.tv_sec;
1322
1323 if (!pfx->pfx_timer && rai->rai_clockskew &&
1324 udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1325 syslog(LOG_INFO,
1326 "<%s> valid lifetime for %s/%d"
1327 " (decr. in real time) inconsistent on %s:"
1328 " %d from %s, %" PRIu32 " from us",
1329 __func__,
1330 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1331 sizeof(prefixbuf)),
1332 pinfo->nd_opt_pi_prefix_len,
1333 ifi->ifi_ifname, preferred_time,
1334 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1335 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1336 inconsistent++;
1337 }
1338 } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1339 syslog(LOG_INFO,
1340 "<%s> valid lifetime for %s/%d"
1341 " inconsistent on %s:"
1342 " %d from %s, %d from us",
1343 __func__,
1344 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1345 sizeof(prefixbuf)),
1346 pinfo->nd_opt_pi_prefix_len,
1347 ifi->ifi_ifname, valid_time,
1348 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1349 sizeof(ntopbuf)), pfx->pfx_validlifetime);
1350 inconsistent++;
1351 }
1352
1353 return (inconsistent);
1354 }
1355
1356 struct prefix *
find_prefix(struct rainfo * rai,struct in6_addr * prefix,int plen)1357 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1358 {
1359 struct prefix *pfx;
1360 int bytelen, bitlen;
1361 char bitmask;
1362
1363 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1364 if (plen != pfx->pfx_prefixlen)
1365 continue;
1366
1367 bytelen = plen / 8;
1368 bitlen = plen % 8;
1369 bitmask = 0xff << (8 - bitlen);
1370
1371 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1372 continue;
1373
1374 if (bitlen == 0 ||
1375 ((prefix->s6_addr[bytelen] & bitmask) ==
1376 (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1377 return (pfx);
1378 }
1379 }
1380
1381 return (NULL);
1382 }
1383
1384 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1385 int
prefix_match(struct in6_addr * p0,int plen0,struct in6_addr * p1,int plen1)1386 prefix_match(struct in6_addr *p0, int plen0,
1387 struct in6_addr *p1, int plen1)
1388 {
1389 int bytelen, bitlen;
1390 char bitmask;
1391
1392 if (plen0 < plen1)
1393 return (0);
1394
1395 bytelen = plen1 / 8;
1396 bitlen = plen1 % 8;
1397 bitmask = 0xff << (8 - bitlen);
1398
1399 if (memcmp((void *)p0, (void *)p1, bytelen))
1400 return (0);
1401
1402 if (bitlen == 0 ||
1403 ((p0->s6_addr[bytelen] & bitmask) ==
1404 (p1->s6_addr[bytelen] & bitmask))) {
1405 return (1);
1406 }
1407
1408 return (0);
1409 }
1410
1411 static int
nd6_options(struct nd_opt_hdr * hdr,int limit,union nd_opt * ndopts,uint32_t optflags)1412 nd6_options(struct nd_opt_hdr *hdr, int limit,
1413 union nd_opt *ndopts, uint32_t optflags)
1414 {
1415 int optlen = 0;
1416
1417 for (; limit > 0; limit -= optlen) {
1418 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1419 syslog(LOG_INFO, "<%s> short option header", __func__);
1420 goto bad;
1421 }
1422
1423 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1424 if (hdr->nd_opt_len == 0) {
1425 syslog(LOG_INFO,
1426 "<%s> bad ND option length(0) (type = %d)",
1427 __func__, hdr->nd_opt_type);
1428 goto bad;
1429 }
1430 optlen = hdr->nd_opt_len << 3;
1431 if (optlen > limit) {
1432 syslog(LOG_INFO, "<%s> short option", __func__);
1433 goto bad;
1434 }
1435
1436 if (hdr->nd_opt_type > ND_OPT_MTU &&
1437 hdr->nd_opt_type != ND_OPT_RDNSS &&
1438 hdr->nd_opt_type != ND_OPT_DNSSL) {
1439 syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1440 __func__, hdr->nd_opt_type);
1441 continue;
1442 }
1443
1444 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1445 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1446 __func__, hdr->nd_opt_type);
1447 continue;
1448 }
1449
1450 /*
1451 * Option length check. Do it here for all fixed-length
1452 * options.
1453 */
1454 switch (hdr->nd_opt_type) {
1455 case ND_OPT_MTU:
1456 if (optlen == sizeof(struct nd_opt_mtu))
1457 break;
1458 goto skip;
1459 case ND_OPT_RDNSS:
1460 if (optlen >= 24 &&
1461 (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1462 break;
1463 goto skip;
1464 case ND_OPT_DNSSL:
1465 if (optlen >= 16 &&
1466 (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1467 break;
1468 goto skip;
1469 case ND_OPT_PREFIX_INFORMATION:
1470 if (optlen == sizeof(struct nd_opt_prefix_info))
1471 break;
1472 skip:
1473 syslog(LOG_INFO, "<%s> invalid option length",
1474 __func__);
1475 continue;
1476 }
1477
1478 switch (hdr->nd_opt_type) {
1479 case ND_OPT_TARGET_LINKADDR:
1480 case ND_OPT_REDIRECTED_HEADER:
1481 case ND_OPT_RDNSS:
1482 case ND_OPT_DNSSL:
1483 break; /* we don't care about these options */
1484 case ND_OPT_SOURCE_LINKADDR:
1485 case ND_OPT_MTU:
1486 if (ndopts->opt_array[hdr->nd_opt_type]) {
1487 syslog(LOG_INFO,
1488 "<%s> duplicated ND option (type = %d)",
1489 __func__, hdr->nd_opt_type);
1490 }
1491 ndopts->opt_array[hdr->nd_opt_type] = hdr;
1492 break;
1493 case ND_OPT_PREFIX_INFORMATION:
1494 {
1495 struct nd_optlist *nol;
1496
1497 if (ndopts->opt_pi == 0) {
1498 ndopts->opt_pi =
1499 (struct nd_opt_prefix_info *)hdr;
1500 continue;
1501 }
1502 nol = malloc(sizeof(*nol));
1503 if (nol == NULL) {
1504 syslog(LOG_ERR, "<%s> can't allocate memory",
1505 __func__);
1506 goto bad;
1507 }
1508 nol->nol_opt = hdr;
1509 TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1510
1511 break;
1512 }
1513 default: /* impossible */
1514 break;
1515 }
1516 }
1517
1518 return (0);
1519
1520 bad:
1521 free_ndopts(ndopts);
1522
1523 return (-1);
1524 }
1525
1526 static void
free_ndopts(union nd_opt * ndopts)1527 free_ndopts(union nd_opt *ndopts)
1528 {
1529 struct nd_optlist *nol;
1530
1531 while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1532 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1533 free(nol);
1534 }
1535 }
1536
1537 void
sock_open(struct sockinfo * s)1538 sock_open(struct sockinfo *s)
1539 {
1540 struct icmp6_filter filt;
1541 int on;
1542 /* XXX: should be max MTU attached to the node */
1543 static char answer[1500];
1544
1545 syslog(LOG_DEBUG, "<%s> enter", __func__);
1546
1547 if (s == NULL) {
1548 syslog(LOG_ERR, "<%s> internal error", __func__);
1549 exit(1);
1550 }
1551 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1552 CMSG_SPACE(sizeof(int));
1553 rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1554 if (rcvcmsgbuf == NULL) {
1555 syslog(LOG_ERR, "<%s> not enough core", __func__);
1556 exit(1);
1557 }
1558
1559 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1560 CMSG_SPACE(sizeof(int));
1561 sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1562 if (sndcmsgbuf == NULL) {
1563 syslog(LOG_ERR, "<%s> not enough core", __func__);
1564 exit(1);
1565 }
1566
1567 if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1568 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1569 exit(1);
1570 }
1571 /* specify to tell receiving interface */
1572 on = 1;
1573 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1574 sizeof(on)) < 0) {
1575 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1576 strerror(errno));
1577 exit(1);
1578 }
1579 on = 1;
1580 /* specify to tell value of hoplimit field of received IP6 hdr */
1581 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1582 sizeof(on)) < 0) {
1583 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1584 strerror(errno));
1585 exit(1);
1586 }
1587 ICMP6_FILTER_SETBLOCKALL(&filt);
1588 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1589 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1590 if (mcastif != NULL)
1591 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1592
1593 if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1594 sizeof(filt)) < 0) {
1595 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1596 __func__, strerror(errno));
1597 exit(1);
1598 }
1599
1600 /* initialize msghdr for receiving packets */
1601 rcviov[0].iov_base = (caddr_t)answer;
1602 rcviov[0].iov_len = sizeof(answer);
1603 rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1604 rcvmhdr.msg_namelen = sizeof(rcvfrom);
1605 rcvmhdr.msg_iov = rcviov;
1606 rcvmhdr.msg_iovlen = 1;
1607 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1608 rcvmhdr.msg_controllen = rcvcmsgbuflen;
1609
1610 /* initialize msghdr for sending packets */
1611 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1612 sndmhdr.msg_iov = sndiov;
1613 sndmhdr.msg_iovlen = 1;
1614 sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1615 sndmhdr.msg_controllen = sndcmsgbuflen;
1616
1617 return;
1618 }
1619
1620 /* open a routing socket to watch the routing table */
1621 static void
rtsock_open(struct sockinfo * s)1622 rtsock_open(struct sockinfo *s)
1623 {
1624 if (s == NULL) {
1625 syslog(LOG_ERR, "<%s> internal error", __func__);
1626 exit(1);
1627 }
1628 if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1629 syslog(LOG_ERR,
1630 "<%s> socket: %s", __func__, strerror(errno));
1631 exit(1);
1632 }
1633 }
1634
1635 struct ifinfo *
if_indextoifinfo(int idx)1636 if_indextoifinfo(int idx)
1637 {
1638 struct ifinfo *ifi;
1639 char *name, name0[IFNAMSIZ];
1640
1641 /* Check if the interface has a valid name or not. */
1642 if (if_indextoname(idx, name0) == NULL)
1643 return (NULL);
1644
1645 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1646 if (ifi->ifi_ifindex == idx)
1647 return (ifi);
1648 }
1649
1650 if (ifi != NULL)
1651 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1652 __func__, idx);
1653 else
1654 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1655 __func__, idx);
1656
1657 return (NULL); /* search failed */
1658 }
1659
1660 void
ra_output(struct ifinfo * ifi)1661 ra_output(struct ifinfo *ifi)
1662 {
1663 int i;
1664 struct cmsghdr *cm;
1665 struct in6_pktinfo *pi;
1666 struct soliciter *sol;
1667 struct rainfo *rai;
1668
1669 switch (ifi->ifi_state) {
1670 case IFI_STATE_CONFIGURED:
1671 rai = ifi->ifi_rainfo;
1672 break;
1673 case IFI_STATE_TRANSITIVE:
1674 rai = ifi->ifi_rainfo_trans;
1675 break;
1676 case IFI_STATE_UNCONFIGURED:
1677 syslog(LOG_DEBUG, "<%s> %s is unconfigured. "
1678 "Skip sending RAs.",
1679 __func__, ifi->ifi_ifname);
1680 return;
1681 default:
1682 rai = NULL;
1683 }
1684 if (rai == NULL) {
1685 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1686 "Skip sending RAs.",
1687 __func__, ifi->ifi_ifname);
1688 return;
1689 }
1690 if (!(ifi->ifi_flags & IFF_UP)) {
1691 syslog(LOG_DEBUG, "<%s> %s is not up. "
1692 "Skip sending RAs.",
1693 __func__, ifi->ifi_ifname);
1694 return;
1695 }
1696 /*
1697 * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1698 *
1699 * (lifetime == 0) = output
1700 * (lifetime != 0 && (check_accept_rtadv()) = no output
1701 *
1702 * Basically, hosts MUST NOT send Router Advertisement
1703 * messages at any time (RFC 4861, Section 6.2.3). However, it
1704 * would sometimes be useful to allow hosts to advertise some
1705 * parameters such as prefix information and link MTU. Thus,
1706 * we allow hosts to invoke rtadvd only when router lifetime
1707 * (on every advertising interface) is explicitly set
1708 * zero. (see also the above section)
1709 */
1710 syslog(LOG_DEBUG,
1711 "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1712 "on %s", __func__,
1713 rai->rai_lifetime,
1714 check_accept_rtadv(ifi->ifi_ifindex),
1715 getinet6sysctl(IPV6CTL_FORWARDING),
1716 ifi->ifi_ifname);
1717
1718 if (rai->rai_lifetime != 0) {
1719 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1720 syslog(LOG_ERR,
1721 "non-zero lifetime RA "
1722 "but net.inet6.ip6.forwarding=0. "
1723 "Ignored.");
1724 return;
1725 }
1726 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1727 syslog(LOG_ERR,
1728 "non-zero lifetime RA "
1729 "on RA receiving interface %s."
1730 " Ignored.", ifi->ifi_ifname);
1731 return;
1732 }
1733 }
1734
1735 make_packet(rai); /* XXX: inefficient */
1736
1737 sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1738 sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1739 sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1740
1741 cm = CMSG_FIRSTHDR(&sndmhdr);
1742 /* specify the outgoing interface */
1743 cm->cmsg_level = IPPROTO_IPV6;
1744 cm->cmsg_type = IPV6_PKTINFO;
1745 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1746 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1747 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
1748 pi->ipi6_ifindex = ifi->ifi_ifindex;
1749
1750 /* specify the hop limit of the packet */
1751 {
1752 int hoplimit = 255;
1753
1754 cm = CMSG_NXTHDR(&sndmhdr, cm);
1755 cm->cmsg_level = IPPROTO_IPV6;
1756 cm->cmsg_type = IPV6_HOPLIMIT;
1757 cm->cmsg_len = CMSG_LEN(sizeof(int));
1758 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1759 }
1760
1761 syslog(LOG_DEBUG,
1762 "<%s> send RA on %s, # of RS waitings = %d",
1763 __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1764
1765 i = sendmsg(sock.si_fd, &sndmhdr, 0);
1766
1767 if (i < 0 || (size_t)i != rai->rai_ra_datalen) {
1768 if (i < 0) {
1769 syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1770 __func__, ifi->ifi_ifname,
1771 strerror(errno));
1772 }
1773 }
1774
1775 /*
1776 * unicast advertisements
1777 * XXX commented out. reason: though spec does not forbit it, unicast
1778 * advert does not really help
1779 */
1780 while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1781 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1782 free(sol);
1783 }
1784
1785 /* update timestamp */
1786 clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1787
1788 /* update counter */
1789 ifi->ifi_rs_waitcount = 0;
1790 ifi->ifi_raoutput++;
1791
1792 switch (ifi->ifi_state) {
1793 case IFI_STATE_CONFIGURED:
1794 if (ifi->ifi_burstcount > 0)
1795 ifi->ifi_burstcount--;
1796 break;
1797 case IFI_STATE_TRANSITIVE:
1798 ifi->ifi_burstcount--;
1799 if (ifi->ifi_burstcount == 0) {
1800 if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1801 /* Initial burst finished. */
1802 if (ifi->ifi_rainfo_trans != NULL)
1803 ifi->ifi_rainfo_trans = NULL;
1804 }
1805
1806 /* Remove burst RA information */
1807 if (ifi->ifi_rainfo_trans != NULL) {
1808 rm_rainfo(ifi->ifi_rainfo_trans);
1809 ifi->ifi_rainfo_trans = NULL;
1810 }
1811
1812 if (ifi->ifi_rainfo != NULL) {
1813 /*
1814 * TRANSITIVE -> CONFIGURED
1815 *
1816 * After initial burst or transition from
1817 * one configuration to another,
1818 * ifi_rainfo always points to the next RA
1819 * information.
1820 */
1821 ifi->ifi_state = IFI_STATE_CONFIGURED;
1822 syslog(LOG_DEBUG,
1823 "<%s> ifname=%s marked as "
1824 "CONFIGURED.", __func__,
1825 ifi->ifi_ifname);
1826 } else {
1827 /*
1828 * TRANSITIVE -> UNCONFIGURED
1829 *
1830 * If ifi_rainfo points to NULL, this
1831 * interface is shutting down.
1832 *
1833 */
1834 int error;
1835
1836 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1837 syslog(LOG_DEBUG,
1838 "<%s> ifname=%s marked as "
1839 "UNCONFIGURED.", __func__,
1840 ifi->ifi_ifname);
1841 error = sock_mc_leave(&sock,
1842 ifi->ifi_ifindex);
1843 if (error)
1844 exit(1);
1845 }
1846 }
1847 break;
1848 }
1849 }
1850
1851 /* process RA timer */
1852 struct rtadvd_timer *
ra_timeout(void * arg)1853 ra_timeout(void *arg)
1854 {
1855 struct ifinfo *ifi;
1856
1857 ifi = (struct ifinfo *)arg;
1858 syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1859 __func__, ifi->ifi_ifname);
1860
1861 ra_output(ifi);
1862
1863 return (ifi->ifi_ra_timer);
1864 }
1865
1866 /* update RA timer */
1867 void
ra_timer_update(void * arg,struct timespec * tm)1868 ra_timer_update(void *arg, struct timespec *tm)
1869 {
1870 uint16_t interval;
1871 struct rainfo *rai;
1872 struct ifinfo *ifi;
1873
1874 ifi = (struct ifinfo *)arg;
1875 rai = ifi->ifi_rainfo;
1876 interval = 0;
1877
1878 switch (ifi->ifi_state) {
1879 case IFI_STATE_UNCONFIGURED:
1880 return;
1881 break;
1882 case IFI_STATE_CONFIGURED:
1883 /*
1884 * Whenever a multicast advertisement is sent from
1885 * an interface, the timer is reset to a
1886 * uniformly-distributed random value between the
1887 * interface's configured MinRtrAdvInterval and
1888 * MaxRtrAdvInterval (RFC4861 6.2.4).
1889 */
1890 interval = rai->rai_mininterval;
1891 interval += arc4random_uniform(rai->rai_maxinterval -
1892 rai->rai_mininterval);
1893 break;
1894 case IFI_STATE_TRANSITIVE:
1895 /*
1896 * For the first few advertisements (up to
1897 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1898 * interval is greater than
1899 * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1900 * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC
1901 * 4861 6.2.4)
1902 *
1903 * In such cases, the router SHOULD transmit one or more
1904 * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1905 * multicast Router Advertisements on the interface with a
1906 * Router Lifetime field of zero. (RFC 4861 6.2.5)
1907 */
1908 interval = ifi->ifi_burstinterval;
1909 break;
1910 }
1911
1912 tm->tv_sec = interval;
1913 tm->tv_nsec = 0;
1914
1915 syslog(LOG_DEBUG,
1916 "<%s> RA timer on %s is set to %ld:%ld",
1917 __func__, ifi->ifi_ifname,
1918 (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1919
1920 return;
1921 }
1922