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 /* Reachable Time */
1156 reachabletime = ntohl(nra->nd_ra_reachable);
1157 if (reachabletime && rai->rai_reachabletime &&
1158 reachabletime != rai->rai_reachabletime) {
1159 syslog(LOG_NOTICE,
1160 "ReachableTime inconsistent on %s:"
1161 " %d from %s, %d from us",
1162 ifi->ifi_ifname, reachabletime,
1163 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1164 sizeof(ntopbuf)), rai->rai_reachabletime);
1165 inconsistent++;
1166 }
1167 /* Retrans Timer */
1168 retranstimer = ntohl(nra->nd_ra_retransmit);
1169 if (retranstimer && rai->rai_retranstimer &&
1170 retranstimer != rai->rai_retranstimer) {
1171 syslog(LOG_NOTICE,
1172 "RetranceTimer inconsistent on %s:"
1173 " %d from %s, %d from us",
1174 ifi->ifi_ifname, retranstimer,
1175 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1176 sizeof(ntopbuf)), rai->rai_retranstimer);
1177 inconsistent++;
1178 }
1179 /* Values in the MTU options */
1180 if (ndopts.opt_mtu) {
1181 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1182 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1183 syslog(LOG_NOTICE,
1184 "MTU option value inconsistent on %s:"
1185 " %d from %s, %d from us",
1186 ifi->ifi_ifname, mtu,
1187 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1188 sizeof(ntopbuf)), rai->rai_linkmtu);
1189 inconsistent++;
1190 }
1191 }
1192 /* Preferred and Valid Lifetimes for prefixes */
1193 {
1194 struct nd_optlist *nol;
1195
1196 if (ndopts.opt_pi)
1197 if (prefix_check(ndopts.opt_pi, rai, from))
1198 inconsistent++;
1199
1200 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1201 if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1202 rai, from))
1203 inconsistent++;
1204 }
1205
1206 if (inconsistent)
1207 ifi->ifi_rainconsistent++;
1208
1209 done:
1210 free_ndopts(&ndopts);
1211 return;
1212 }
1213
1214 static uint32_t
udiff(uint32_t u,uint32_t v)1215 udiff(uint32_t u, uint32_t v)
1216 {
1217 return (u >= v ? u - v : v - u);
1218 }
1219
1220 /* return a non-zero value if the received prefix is inconsistent with ours */
1221 static int
prefix_check(struct nd_opt_prefix_info * pinfo,struct rainfo * rai,struct sockaddr_in6 * from)1222 prefix_check(struct nd_opt_prefix_info *pinfo,
1223 struct rainfo *rai, struct sockaddr_in6 *from)
1224 {
1225 struct ifinfo *ifi;
1226 uint32_t preferred_time, valid_time;
1227 struct prefix *pfx;
1228 int inconsistent = 0;
1229 char ntopbuf[INET6_ADDRSTRLEN];
1230 char prefixbuf[INET6_ADDRSTRLEN];
1231 struct timespec now;
1232
1233 #if 0 /* impossible */
1234 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1235 return (0);
1236 #endif
1237 ifi = rai->rai_ifinfo;
1238 /*
1239 * log if the adveritsed prefix has link-local scope(sanity check?)
1240 */
1241 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1242 syslog(LOG_INFO,
1243 "<%s> link-local prefix %s/%d is advertised "
1244 "from %s on %s",
1245 __func__,
1246 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1247 sizeof(prefixbuf)),
1248 pinfo->nd_opt_pi_prefix_len,
1249 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1250 sizeof(ntopbuf)), ifi->ifi_ifname);
1251
1252 if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1253 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1254 syslog(LOG_INFO,
1255 "<%s> prefix %s/%d from %s on %s is not in our list",
1256 __func__,
1257 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1258 sizeof(prefixbuf)),
1259 pinfo->nd_opt_pi_prefix_len,
1260 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1261 sizeof(ntopbuf)), ifi->ifi_ifname);
1262 return (0);
1263 }
1264
1265 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1266 if (pfx->pfx_pltimeexpire) {
1267 /*
1268 * The lifetime is decremented in real time, so we should
1269 * compare the expiration time.
1270 * (RFC 2461 Section 6.2.7.)
1271 * XXX: can we really expect that all routers on the link
1272 * have synchronized clocks?
1273 */
1274 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1275 preferred_time += now.tv_sec;
1276
1277 if (!pfx->pfx_timer && rai->rai_clockskew &&
1278 udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1279 syslog(LOG_INFO,
1280 "<%s> preferred lifetime for %s/%d"
1281 " (decr. in real time) inconsistent on %s:"
1282 " %" PRIu32 " from %s, %" PRIu32 " from us",
1283 __func__,
1284 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1285 sizeof(prefixbuf)),
1286 pinfo->nd_opt_pi_prefix_len,
1287 ifi->ifi_ifname, preferred_time,
1288 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1289 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1290 inconsistent++;
1291 }
1292 } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1293 syslog(LOG_INFO,
1294 "<%s> preferred lifetime for %s/%d"
1295 " inconsistent on %s:"
1296 " %d from %s, %d from us",
1297 __func__,
1298 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1299 sizeof(prefixbuf)),
1300 pinfo->nd_opt_pi_prefix_len,
1301 ifi->ifi_ifname, preferred_time,
1302 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1303 sizeof(ntopbuf)), pfx->pfx_preflifetime);
1304
1305 valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1306 if (pfx->pfx_vltimeexpire) {
1307 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1308 valid_time += now.tv_sec;
1309
1310 if (!pfx->pfx_timer && rai->rai_clockskew &&
1311 udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1312 syslog(LOG_INFO,
1313 "<%s> valid lifetime for %s/%d"
1314 " (decr. in real time) inconsistent on %s:"
1315 " %d from %s, %" PRIu32 " from us",
1316 __func__,
1317 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1318 sizeof(prefixbuf)),
1319 pinfo->nd_opt_pi_prefix_len,
1320 ifi->ifi_ifname, preferred_time,
1321 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1322 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1323 inconsistent++;
1324 }
1325 } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1326 syslog(LOG_INFO,
1327 "<%s> valid lifetime for %s/%d"
1328 " inconsistent on %s:"
1329 " %d from %s, %d from us",
1330 __func__,
1331 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1332 sizeof(prefixbuf)),
1333 pinfo->nd_opt_pi_prefix_len,
1334 ifi->ifi_ifname, valid_time,
1335 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1336 sizeof(ntopbuf)), pfx->pfx_validlifetime);
1337 inconsistent++;
1338 }
1339
1340 return (inconsistent);
1341 }
1342
1343 struct prefix *
find_prefix(struct rainfo * rai,struct in6_addr * prefix,int plen)1344 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1345 {
1346 struct prefix *pfx;
1347 int bytelen, bitlen;
1348 char bitmask;
1349
1350 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1351 if (plen != pfx->pfx_prefixlen)
1352 continue;
1353
1354 bytelen = plen / 8;
1355 bitlen = plen % 8;
1356 bitmask = 0xff << (8 - bitlen);
1357
1358 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1359 continue;
1360
1361 if (bitlen == 0 ||
1362 ((prefix->s6_addr[bytelen] & bitmask) ==
1363 (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1364 return (pfx);
1365 }
1366 }
1367
1368 return (NULL);
1369 }
1370
1371 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1372 int
prefix_match(struct in6_addr * p0,int plen0,struct in6_addr * p1,int plen1)1373 prefix_match(struct in6_addr *p0, int plen0,
1374 struct in6_addr *p1, int plen1)
1375 {
1376 int bytelen, bitlen;
1377 char bitmask;
1378
1379 if (plen0 < plen1)
1380 return (0);
1381
1382 bytelen = plen1 / 8;
1383 bitlen = plen1 % 8;
1384 bitmask = 0xff << (8 - bitlen);
1385
1386 if (memcmp((void *)p0, (void *)p1, bytelen))
1387 return (0);
1388
1389 if (bitlen == 0 ||
1390 ((p0->s6_addr[bytelen] & bitmask) ==
1391 (p1->s6_addr[bytelen] & bitmask))) {
1392 return (1);
1393 }
1394
1395 return (0);
1396 }
1397
1398 static int
nd6_options(struct nd_opt_hdr * hdr,int limit,union nd_opt * ndopts,uint32_t optflags)1399 nd6_options(struct nd_opt_hdr *hdr, int limit,
1400 union nd_opt *ndopts, uint32_t optflags)
1401 {
1402 int optlen = 0;
1403
1404 for (; limit > 0; limit -= optlen) {
1405 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1406 syslog(LOG_INFO, "<%s> short option header", __func__);
1407 goto bad;
1408 }
1409
1410 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1411 if (hdr->nd_opt_len == 0) {
1412 syslog(LOG_INFO,
1413 "<%s> bad ND option length(0) (type = %d)",
1414 __func__, hdr->nd_opt_type);
1415 goto bad;
1416 }
1417 optlen = hdr->nd_opt_len << 3;
1418 if (optlen > limit) {
1419 syslog(LOG_INFO, "<%s> short option", __func__);
1420 goto bad;
1421 }
1422
1423 if (hdr->nd_opt_type > ND_OPT_MTU &&
1424 hdr->nd_opt_type != ND_OPT_RDNSS &&
1425 hdr->nd_opt_type != ND_OPT_DNSSL) {
1426 syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1427 __func__, hdr->nd_opt_type);
1428 continue;
1429 }
1430
1431 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1432 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1433 __func__, hdr->nd_opt_type);
1434 continue;
1435 }
1436
1437 /*
1438 * Option length check. Do it here for all fixed-length
1439 * options.
1440 */
1441 switch (hdr->nd_opt_type) {
1442 case ND_OPT_MTU:
1443 if (optlen == sizeof(struct nd_opt_mtu))
1444 break;
1445 goto skip;
1446 case ND_OPT_RDNSS:
1447 if (optlen >= 24 &&
1448 (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1449 break;
1450 goto skip;
1451 case ND_OPT_DNSSL:
1452 if (optlen >= 16 &&
1453 (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1454 break;
1455 goto skip;
1456 case ND_OPT_PREFIX_INFORMATION:
1457 if (optlen == sizeof(struct nd_opt_prefix_info))
1458 break;
1459 skip:
1460 syslog(LOG_INFO, "<%s> invalid option length",
1461 __func__);
1462 continue;
1463 }
1464
1465 switch (hdr->nd_opt_type) {
1466 case ND_OPT_TARGET_LINKADDR:
1467 case ND_OPT_REDIRECTED_HEADER:
1468 case ND_OPT_RDNSS:
1469 case ND_OPT_DNSSL:
1470 break; /* we don't care about these options */
1471 case ND_OPT_SOURCE_LINKADDR:
1472 case ND_OPT_MTU:
1473 if (ndopts->opt_array[hdr->nd_opt_type]) {
1474 syslog(LOG_INFO,
1475 "<%s> duplicated ND option (type = %d)",
1476 __func__, hdr->nd_opt_type);
1477 }
1478 ndopts->opt_array[hdr->nd_opt_type] = hdr;
1479 break;
1480 case ND_OPT_PREFIX_INFORMATION:
1481 {
1482 struct nd_optlist *nol;
1483
1484 if (ndopts->opt_pi == 0) {
1485 ndopts->opt_pi =
1486 (struct nd_opt_prefix_info *)hdr;
1487 continue;
1488 }
1489 nol = malloc(sizeof(*nol));
1490 if (nol == NULL) {
1491 syslog(LOG_ERR, "<%s> can't allocate memory",
1492 __func__);
1493 goto bad;
1494 }
1495 nol->nol_opt = hdr;
1496 TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1497
1498 break;
1499 }
1500 default: /* impossible */
1501 break;
1502 }
1503 }
1504
1505 return (0);
1506
1507 bad:
1508 free_ndopts(ndopts);
1509
1510 return (-1);
1511 }
1512
1513 static void
free_ndopts(union nd_opt * ndopts)1514 free_ndopts(union nd_opt *ndopts)
1515 {
1516 struct nd_optlist *nol;
1517
1518 while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1519 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1520 free(nol);
1521 }
1522 }
1523
1524 void
sock_open(struct sockinfo * s)1525 sock_open(struct sockinfo *s)
1526 {
1527 struct icmp6_filter filt;
1528 int on;
1529 /* XXX: should be max MTU attached to the node */
1530 static char answer[1500];
1531
1532 syslog(LOG_DEBUG, "<%s> enter", __func__);
1533
1534 if (s == NULL) {
1535 syslog(LOG_ERR, "<%s> internal error", __func__);
1536 exit(1);
1537 }
1538 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1539 CMSG_SPACE(sizeof(int));
1540 rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1541 if (rcvcmsgbuf == NULL) {
1542 syslog(LOG_ERR, "<%s> not enough core", __func__);
1543 exit(1);
1544 }
1545
1546 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1547 CMSG_SPACE(sizeof(int));
1548 sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1549 if (sndcmsgbuf == NULL) {
1550 syslog(LOG_ERR, "<%s> not enough core", __func__);
1551 exit(1);
1552 }
1553
1554 if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1555 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1556 exit(1);
1557 }
1558 /* specify to tell receiving interface */
1559 on = 1;
1560 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1561 sizeof(on)) < 0) {
1562 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1563 strerror(errno));
1564 exit(1);
1565 }
1566 on = 1;
1567 /* specify to tell value of hoplimit field of received IP6 hdr */
1568 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1569 sizeof(on)) < 0) {
1570 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1571 strerror(errno));
1572 exit(1);
1573 }
1574 ICMP6_FILTER_SETBLOCKALL(&filt);
1575 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1576 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1577 if (mcastif != NULL)
1578 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1579
1580 if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1581 sizeof(filt)) < 0) {
1582 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1583 __func__, strerror(errno));
1584 exit(1);
1585 }
1586
1587 /* initialize msghdr for receiving packets */
1588 rcviov[0].iov_base = (caddr_t)answer;
1589 rcviov[0].iov_len = sizeof(answer);
1590 rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1591 rcvmhdr.msg_namelen = sizeof(rcvfrom);
1592 rcvmhdr.msg_iov = rcviov;
1593 rcvmhdr.msg_iovlen = 1;
1594 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1595 rcvmhdr.msg_controllen = rcvcmsgbuflen;
1596
1597 /* initialize msghdr for sending packets */
1598 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1599 sndmhdr.msg_iov = sndiov;
1600 sndmhdr.msg_iovlen = 1;
1601 sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1602 sndmhdr.msg_controllen = sndcmsgbuflen;
1603
1604 return;
1605 }
1606
1607 /* open a routing socket to watch the routing table */
1608 static void
rtsock_open(struct sockinfo * s)1609 rtsock_open(struct sockinfo *s)
1610 {
1611 if (s == NULL) {
1612 syslog(LOG_ERR, "<%s> internal error", __func__);
1613 exit(1);
1614 }
1615 if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1616 syslog(LOG_ERR,
1617 "<%s> socket: %s", __func__, strerror(errno));
1618 exit(1);
1619 }
1620 }
1621
1622 struct ifinfo *
if_indextoifinfo(int idx)1623 if_indextoifinfo(int idx)
1624 {
1625 struct ifinfo *ifi;
1626 char *name, name0[IFNAMSIZ];
1627
1628 /* Check if the interface has a valid name or not. */
1629 if (if_indextoname(idx, name0) == NULL)
1630 return (NULL);
1631
1632 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1633 if (ifi->ifi_ifindex == idx)
1634 return (ifi);
1635 }
1636
1637 if (ifi != NULL)
1638 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1639 __func__, idx);
1640 else
1641 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1642 __func__, idx);
1643
1644 return (NULL); /* search failed */
1645 }
1646
1647 void
ra_output(struct ifinfo * ifi)1648 ra_output(struct ifinfo *ifi)
1649 {
1650 int i;
1651 struct cmsghdr *cm;
1652 struct in6_pktinfo *pi;
1653 struct soliciter *sol;
1654 struct rainfo *rai;
1655
1656 switch (ifi->ifi_state) {
1657 case IFI_STATE_CONFIGURED:
1658 rai = ifi->ifi_rainfo;
1659 break;
1660 case IFI_STATE_TRANSITIVE:
1661 rai = ifi->ifi_rainfo_trans;
1662 break;
1663 case IFI_STATE_UNCONFIGURED:
1664 syslog(LOG_DEBUG, "<%s> %s is unconfigured. "
1665 "Skip sending RAs.",
1666 __func__, ifi->ifi_ifname);
1667 return;
1668 default:
1669 rai = NULL;
1670 }
1671 if (rai == NULL) {
1672 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1673 "Skip sending RAs.",
1674 __func__, ifi->ifi_ifname);
1675 return;
1676 }
1677 if (!(ifi->ifi_flags & IFF_UP)) {
1678 syslog(LOG_DEBUG, "<%s> %s is not up. "
1679 "Skip sending RAs.",
1680 __func__, ifi->ifi_ifname);
1681 return;
1682 }
1683 /*
1684 * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1685 *
1686 * (lifetime == 0) = output
1687 * (lifetime != 0 && (check_accept_rtadv()) = no output
1688 *
1689 * Basically, hosts MUST NOT send Router Advertisement
1690 * messages at any time (RFC 4861, Section 6.2.3). However, it
1691 * would sometimes be useful to allow hosts to advertise some
1692 * parameters such as prefix information and link MTU. Thus,
1693 * we allow hosts to invoke rtadvd only when router lifetime
1694 * (on every advertising interface) is explicitly set
1695 * zero. (see also the above section)
1696 */
1697 syslog(LOG_DEBUG,
1698 "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1699 "on %s", __func__,
1700 rai->rai_lifetime,
1701 check_accept_rtadv(ifi->ifi_ifindex),
1702 getinet6sysctl(IPV6CTL_FORWARDING),
1703 ifi->ifi_ifname);
1704
1705 if (rai->rai_lifetime != 0) {
1706 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1707 syslog(LOG_ERR,
1708 "non-zero lifetime RA "
1709 "but net.inet6.ip6.forwarding=0. "
1710 "Ignored.");
1711 return;
1712 }
1713 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1714 syslog(LOG_ERR,
1715 "non-zero lifetime RA "
1716 "on RA receiving interface %s."
1717 " Ignored.", ifi->ifi_ifname);
1718 return;
1719 }
1720 }
1721
1722 make_packet(rai); /* XXX: inefficient */
1723
1724 sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1725 sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1726 sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1727
1728 cm = CMSG_FIRSTHDR(&sndmhdr);
1729 /* specify the outgoing interface */
1730 cm->cmsg_level = IPPROTO_IPV6;
1731 cm->cmsg_type = IPV6_PKTINFO;
1732 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1733 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1734 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
1735 pi->ipi6_ifindex = ifi->ifi_ifindex;
1736
1737 /* specify the hop limit of the packet */
1738 {
1739 int hoplimit = 255;
1740
1741 cm = CMSG_NXTHDR(&sndmhdr, cm);
1742 cm->cmsg_level = IPPROTO_IPV6;
1743 cm->cmsg_type = IPV6_HOPLIMIT;
1744 cm->cmsg_len = CMSG_LEN(sizeof(int));
1745 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1746 }
1747
1748 syslog(LOG_DEBUG,
1749 "<%s> send RA on %s, # of RS waitings = %d",
1750 __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1751
1752 i = sendmsg(sock.si_fd, &sndmhdr, 0);
1753
1754 if (i < 0 || (size_t)i != rai->rai_ra_datalen) {
1755 if (i < 0) {
1756 syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1757 __func__, ifi->ifi_ifname,
1758 strerror(errno));
1759 }
1760 }
1761
1762 /*
1763 * unicast advertisements
1764 * XXX commented out. reason: though spec does not forbit it, unicast
1765 * advert does not really help
1766 */
1767 while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1768 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1769 free(sol);
1770 }
1771
1772 /* update timestamp */
1773 clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1774
1775 /* update counter */
1776 ifi->ifi_rs_waitcount = 0;
1777 ifi->ifi_raoutput++;
1778
1779 switch (ifi->ifi_state) {
1780 case IFI_STATE_CONFIGURED:
1781 if (ifi->ifi_burstcount > 0)
1782 ifi->ifi_burstcount--;
1783 break;
1784 case IFI_STATE_TRANSITIVE:
1785 ifi->ifi_burstcount--;
1786 if (ifi->ifi_burstcount == 0) {
1787 if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1788 /* Initial burst finished. */
1789 if (ifi->ifi_rainfo_trans != NULL)
1790 ifi->ifi_rainfo_trans = NULL;
1791 }
1792
1793 /* Remove burst RA information */
1794 if (ifi->ifi_rainfo_trans != NULL) {
1795 rm_rainfo(ifi->ifi_rainfo_trans);
1796 ifi->ifi_rainfo_trans = NULL;
1797 }
1798
1799 if (ifi->ifi_rainfo != NULL) {
1800 /*
1801 * TRANSITIVE -> CONFIGURED
1802 *
1803 * After initial burst or transition from
1804 * one configuration to another,
1805 * ifi_rainfo always points to the next RA
1806 * information.
1807 */
1808 ifi->ifi_state = IFI_STATE_CONFIGURED;
1809 syslog(LOG_DEBUG,
1810 "<%s> ifname=%s marked as "
1811 "CONFIGURED.", __func__,
1812 ifi->ifi_ifname);
1813 } else {
1814 /*
1815 * TRANSITIVE -> UNCONFIGURED
1816 *
1817 * If ifi_rainfo points to NULL, this
1818 * interface is shutting down.
1819 *
1820 */
1821 int error;
1822
1823 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1824 syslog(LOG_DEBUG,
1825 "<%s> ifname=%s marked as "
1826 "UNCONFIGURED.", __func__,
1827 ifi->ifi_ifname);
1828 error = sock_mc_leave(&sock,
1829 ifi->ifi_ifindex);
1830 if (error)
1831 exit(1);
1832 }
1833 }
1834 break;
1835 }
1836 }
1837
1838 /* process RA timer */
1839 struct rtadvd_timer *
ra_timeout(void * arg)1840 ra_timeout(void *arg)
1841 {
1842 struct ifinfo *ifi;
1843
1844 ifi = (struct ifinfo *)arg;
1845 syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1846 __func__, ifi->ifi_ifname);
1847
1848 ra_output(ifi);
1849
1850 return (ifi->ifi_ra_timer);
1851 }
1852
1853 /* update RA timer */
1854 void
ra_timer_update(void * arg,struct timespec * tm)1855 ra_timer_update(void *arg, struct timespec *tm)
1856 {
1857 uint16_t interval;
1858 struct rainfo *rai;
1859 struct ifinfo *ifi;
1860
1861 ifi = (struct ifinfo *)arg;
1862 rai = ifi->ifi_rainfo;
1863 interval = 0;
1864
1865 switch (ifi->ifi_state) {
1866 case IFI_STATE_UNCONFIGURED:
1867 return;
1868 break;
1869 case IFI_STATE_CONFIGURED:
1870 /*
1871 * Whenever a multicast advertisement is sent from
1872 * an interface, the timer is reset to a
1873 * uniformly-distributed random value between the
1874 * interface's configured MinRtrAdvInterval and
1875 * MaxRtrAdvInterval (RFC4861 6.2.4).
1876 */
1877 interval = rai->rai_mininterval;
1878 interval += arc4random_uniform(rai->rai_maxinterval -
1879 rai->rai_mininterval);
1880 break;
1881 case IFI_STATE_TRANSITIVE:
1882 /*
1883 * For the first few advertisements (up to
1884 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1885 * interval is greater than
1886 * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1887 * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC
1888 * 4861 6.2.4)
1889 *
1890 * In such cases, the router SHOULD transmit one or more
1891 * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1892 * multicast Router Advertisements on the interface with a
1893 * Router Lifetime field of zero. (RFC 4861 6.2.5)
1894 */
1895 interval = ifi->ifi_burstinterval;
1896 break;
1897 }
1898
1899 tm->tv_sec = interval;
1900 tm->tv_nsec = 0;
1901
1902 syslog(LOG_DEBUG,
1903 "<%s> RA timer on %s is set to %ld:%ld",
1904 __func__, ifi->ifi_ifname,
1905 (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1906
1907 return;
1908 }
1909