1 /* $NetBSD: rtadvd.c,v 1.50 2015/06/15 04:15:33 ozaki-r Exp $ */
2 /* $KAME: rtadvd.c,v 1.92 2005/10/17 14:40:02 suz Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/param.h>
34 #include <sys/socket.h>
35 #include <sys/uio.h>
36 #include <sys/time.h>
37 #include <sys/queue.h>
38
39 #include <net/if.h>
40 #include <net/route.h>
41 #include <net/if_dl.h>
42 #include <netinet/in.h>
43 #include <netinet/ip6.h>
44 #include <netinet6/ip6_var.h>
45 #include <netinet/icmp6.h>
46
47 #include <arpa/inet.h>
48
49 #include <time.h>
50 #include <unistd.h>
51 #include <stdio.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <string.h>
55 #include <stdlib.h>
56 #include <syslog.h>
57 #if defined(__NetBSD__) || defined(__minix)
58 #include <util.h>
59 #endif
60 #include <poll.h>
61 #include <pwd.h>
62
63 #include "rtadvd.h"
64 #include "rrenum.h"
65 #include "advcap.h"
66 #include "timer.h"
67 #include "if.h"
68 #include "config.h"
69 #include "dump.h"
70
71 struct msghdr rcvmhdr;
72 static unsigned char *rcvcmsgbuf;
73 static size_t rcvcmsgbuflen;
74 static unsigned char *sndcmsgbuf;
75 static size_t sndcmsgbuflen;
76 volatile sig_atomic_t do_dump;
77 volatile sig_atomic_t do_reconf;
78 volatile sig_atomic_t do_die;
79 struct msghdr sndmhdr;
80 struct iovec rcviov[2];
81 struct iovec sndiov[2];
82 struct sockaddr_in6 rcvfrom;
83 static const char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX configurable */
84 static char *mcastif;
85 int sock;
86 int rtsock = -1;
87 int accept_rr = 0;
88 int dflag = 0, sflag = 0;
89
90 static char **if_argv;
91 static int if_argc;
92
93 char *conffile = NULL;
94
95 struct ralist_head_t ralist = TAILQ_HEAD_INITIALIZER(ralist);
96
97 struct nd_optlist {
98 TAILQ_ENTRY(nd_optlist) next;
99 struct nd_opt_hdr *opt;
100 };
101 union nd_opts {
102 struct nd_opt_hdr *nd_opt_array[9];
103 struct {
104 struct nd_opt_hdr *zero;
105 struct nd_opt_hdr *src_lladdr;
106 struct nd_opt_hdr *tgt_lladdr;
107 struct nd_opt_prefix_info *pi;
108 struct nd_opt_rd_hdr *rh;
109 struct nd_opt_mtu *mtu;
110 TAILQ_HEAD(, nd_optlist) list;
111 } nd_opt_each;
112 };
113 #define nd_opts_src_lladdr nd_opt_each.src_lladdr
114 #define nd_opts_tgt_lladdr nd_opt_each.tgt_lladdr
115 #define nd_opts_pi nd_opt_each.pi
116 #define nd_opts_rh nd_opt_each.rh
117 #define nd_opts_mtu nd_opt_each.mtu
118 #define nd_opts_list nd_opt_each.list
119
120 #define NDOPT_FLAG_SRCLINKADDR (1 << 0)
121 #define NDOPT_FLAG_TGTLINKADDR (1 << 1)
122 #define NDOPT_FLAG_PREFIXINFO (1 << 2)
123 #define NDOPT_FLAG_RDHDR (1 << 3)
124 #define NDOPT_FLAG_MTU (1 << 4)
125 #define NDOPT_FLAG_RDNSS (1 << 5)
126 #define NDOPT_FLAG_DNSSL (1 << 6)
127
128 uint32_t ndopt_flags[] = {
129 [ND_OPT_SOURCE_LINKADDR] = NDOPT_FLAG_SRCLINKADDR,
130 [ND_OPT_TARGET_LINKADDR] = NDOPT_FLAG_TGTLINKADDR,
131 [ND_OPT_PREFIX_INFORMATION] = NDOPT_FLAG_PREFIXINFO,
132 [ND_OPT_REDIRECTED_HEADER] = NDOPT_FLAG_RDHDR,
133 [ND_OPT_MTU] = NDOPT_FLAG_MTU,
134 [ND_OPT_RDNSS] = NDOPT_FLAG_RDNSS,
135 [ND_OPT_DNSSL] = NDOPT_FLAG_DNSSL,
136 };
137
138 struct sockaddr_in6 sin6_linklocal_allnodes = {
139 .sin6_len = sizeof(sin6_linklocal_allnodes),
140 .sin6_family = AF_INET6,
141 .sin6_addr = IN6ADDR_LINKLOCAL_ALLNODES_INIT,
142 };
143 #ifdef notdef
144 struct sockaddr_in6 sin6_linklocal_allrouters = {
145 .sin6_len = sizeof(sin6_linklocal_allrouters),
146 .sin6_family = AF_INET6,
147 .sin6_addr = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT,
148 };
149 #endif
150 struct sockaddr_in6 sin6_sitelocal_allrouters = {
151 .sin6_len = sizeof(sin6_sitelocal_allrouters),
152 .sin6_family = AF_INET6,
153 .sin6_addr = IN6ADDR_SITELOCAL_ALLROUTERS_INIT,
154 };
155
156 static void set_die(int);
157 static void die(void);
158 static void set_reconf(int);
159 static void sock_open(void);
160 static void rtsock_open(void);
161 static void rtadvd_input(void);
162 static void rs_input(int, struct nd_router_solicit *,
163 struct in6_pktinfo *, struct sockaddr_in6 *);
164 static void ra_input(int, struct nd_router_advert *,
165 struct in6_pktinfo *, struct sockaddr_in6 *);
166 static struct rainfo *ra_output(struct rainfo *);
167 static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
168 struct sockaddr_in6 *);
169 static int nd6_options(struct nd_opt_hdr *, int, union nd_opts *, uint32_t);
170 static void free_ndopts(union nd_opts *);
171 static void rtmsg_input(void);
172 static void rtadvd_set_dump_file(int);
173
174 int
main(int argc,char * argv[])175 main(int argc, char *argv[])
176 {
177 struct pollfd set[2];
178 struct timespec *timeout;
179 int i, ch;
180 int fflag = 0, logopt;
181 struct passwd *pw;
182
183 /* get command line options and arguments */
184 #define OPTIONS "c:dDfM:Rs"
185 while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
186 #undef OPTIONS
187 switch (ch) {
188 case 'c':
189 conffile = optarg;
190 break;
191 case 'd':
192 dflag = 1;
193 break;
194 case 'D':
195 dflag = 2;
196 break;
197 case 'f':
198 fflag = 1;
199 break;
200 case 'M':
201 mcastif = optarg;
202 break;
203 case 'R':
204 fprintf(stderr, "rtadvd: "
205 "the -R option is currently ignored.\n");
206 /* accept_rr = 1; */
207 /* run anyway... */
208 break;
209 case 's':
210 sflag = 1;
211 break;
212 }
213 }
214 argc -= optind;
215 argv += optind;
216 if (argc == 0) {
217 fprintf(stderr,
218 "usage: rtadvd [-DdfRs] [-c conffile]"
219 " [-M ifname] interface ...\n");
220 exit(1);
221 }
222
223 logopt = LOG_NDELAY | LOG_PID;
224 if (fflag)
225 logopt |= LOG_PERROR;
226 openlog("rtadvd", logopt, LOG_DAEMON);
227
228 /* set log level */
229 if (dflag == 0)
230 (void)setlogmask(LOG_UPTO(LOG_ERR));
231 if (dflag == 1)
232 (void)setlogmask(LOG_UPTO(LOG_INFO));
233
234 errno = 0; /* Ensure errno is 0 so we know if getpwnam errors or not */
235 if ((pw = getpwnam(RTADVD_USER)) == NULL) {
236 if (errno == 0)
237 syslog(LOG_ERR,
238 "user %s does not exist, aborting",
239 RTADVD_USER);
240 else
241 syslog(LOG_ERR, "getpwnam: %s: %m", RTADVD_USER);
242 exit(1);
243 }
244
245 /* timer initialization */
246 rtadvd_timer_init();
247
248 if_argc = argc;
249 if_argv = argv;
250 while (argc--)
251 getconfig(*argv++, 1);
252
253 if (!fflag)
254 daemon(1, 0);
255
256 sock_open();
257
258 #if defined(__NetBSD__) || defined(__minix)
259 /* record the current PID */
260 if (pidfile(NULL) < 0) {
261 syslog(LOG_ERR,
262 "<%s> failed to open the pid log file, run anyway.",
263 __func__);
264 }
265 #endif
266
267 set[0].fd = sock;
268 set[0].events = POLLIN;
269 if (sflag == 0) {
270 rtsock_open();
271 set[1].fd = rtsock;
272 set[1].events = POLLIN;
273 } else
274 set[1].fd = -1;
275
276 syslog(LOG_INFO, "dropping privileges to %s", RTADVD_USER);
277 if (chroot(pw->pw_dir) == -1) {
278 syslog(LOG_ERR, "chroot: %s: %m", pw->pw_dir);
279 exit(1);
280 }
281 if (chdir("/") == -1) {
282 syslog(LOG_ERR, "chdir: /: %m");
283 exit(1);
284 }
285 if (setgroups(1, &pw->pw_gid) == -1 ||
286 setgid(pw->pw_gid) == -1 ||
287 setuid(pw->pw_uid) == -1)
288 {
289 syslog(LOG_ERR, "failed to drop privileges: %m");
290 exit(1);
291 }
292
293 signal(SIGINT, set_die);
294 signal(SIGTERM, set_die);
295 signal(SIGHUP, set_reconf);
296 signal(SIGUSR1, rtadvd_set_dump_file);
297
298 for (;;) {
299 if (do_dump) { /* SIGUSR1 */
300 do_dump = 0;
301 rtadvd_dump_file(dumpfilename);
302 }
303
304 if (do_reconf) { /* SIGHUP */
305 do_reconf = 0;
306 syslog(LOG_INFO, "<%s> reloading config on SIGHUP",
307 __func__);
308 argc = if_argc;
309 argv = if_argv;
310 while (argc--)
311 getconfig(*argv++, 0);
312 }
313
314 /* timer expiration check and reset the timer */
315 timeout = rtadvd_check_timer();
316
317 if (do_die) {
318 die();
319 /*NOTREACHED*/
320 }
321
322 if (timeout != NULL) {
323 syslog(LOG_DEBUG,
324 "<%s> set timer to %ld:%ld. waiting for "
325 "inputs or timeout", __func__,
326 (long int)timeout->tv_sec,
327 (long int)timeout->tv_nsec);
328 } else {
329 syslog(LOG_DEBUG,
330 "<%s> there's no timer. waiting for inputs",
331 __func__);
332 }
333
334 if ((i = poll(set, 2, timeout ? (timeout->tv_sec * 1000 +
335 (timeout->tv_nsec + 999999) / 1000000) : INFTIM)) < 0)
336 {
337 /* EINTR would occur upon SIGUSR1 for status dump */
338 if (errno != EINTR)
339 syslog(LOG_ERR, "<%s> poll: %m", __func__);
340 continue;
341 }
342 if (i == 0) /* timeout */
343 continue;
344 if (rtsock != -1 && set[1].revents & POLLIN)
345 rtmsg_input();
346 if (set[0].revents & POLLIN)
347 rtadvd_input();
348 }
349 exit(0); /* NOTREACHED */
350 }
351
352 static void
rtadvd_set_dump_file(__unused int sig)353 rtadvd_set_dump_file(__unused int sig)
354 {
355
356 do_dump = 1;
357 }
358
359 static void
set_reconf(__unused int sig)360 set_reconf(__unused int sig)
361 {
362
363 do_reconf = 1;
364 }
365
366 static void
set_die(__unused int sig)367 set_die(__unused int sig)
368 {
369
370 do_die = 1;
371 }
372
373 static void
die(void)374 die(void)
375 {
376 static int waiting;
377 struct rainfo *rai, *ran;
378 struct rdnss *rdnss;
379 struct dnssl *dnssl;
380
381 if (waiting) {
382 if (TAILQ_FIRST(&ralist)) {
383 syslog(LOG_INFO,
384 "<%s> waiting for expiration of all RA timers",
385 __func__);
386 return;
387 }
388 syslog(LOG_NOTICE, "<%s> gracefully terminated", __func__);
389 free(rcvcmsgbuf);
390 free(sndcmsgbuf);
391 exit(0);
392 /* NOT REACHED */
393 }
394
395 if (TAILQ_FIRST(&ralist) == NULL) {
396 syslog(LOG_NOTICE, "<%s> gracefully terminated", __func__);
397 exit(0);
398 /* NOT REACHED */
399 }
400
401 waiting = 1;
402 syslog(LOG_NOTICE, "<%s> final RA transmission started", __func__);
403
404 TAILQ_FOREACH_SAFE(rai, &ralist, next, ran) {
405 if (rai->leaving) {
406 TAILQ_REMOVE(&ralist, rai, next);
407 TAILQ_INSERT_HEAD(&ralist, rai->leaving, next);
408 rai->leaving->leaving = rai->leaving;
409 rai->leaving->leaving_for = rai->leaving;
410 free_rainfo(rai);
411 continue;
412 }
413 rai->lifetime = 0;
414 TAILQ_FOREACH(rdnss, &rai->rdnss, next)
415 rdnss->lifetime = 0;
416 TAILQ_FOREACH(dnssl, &rai->dnssl, next)
417 dnssl->lifetime = 0;
418 make_packet(rai);
419 rai->leaving = rai;
420 rai->leaving_for = rai;
421 rai->initcounter = MAX_INITIAL_RTR_ADVERTISEMENTS;
422 rai->mininterval = MIN_DELAY_BETWEEN_RAS;
423 rai->maxinterval = MIN_DELAY_BETWEEN_RAS;
424 rai->leaving_adv = MAX_FINAL_RTR_ADVERTISEMENTS;
425 ra_output(rai);
426 ra_timer_update((void *)rai, &rai->timer->tm);
427 rtadvd_set_timer(&rai->timer->tm, rai->timer);
428 }
429 }
430
431 static void
rtmsg_input(void)432 rtmsg_input(void)
433 {
434 int n, type, ifindex = 0, plen;
435 size_t len;
436 union rt_msghdr_buf {
437 struct rt_msghdr rt_msghdr;
438 char data[2048];
439 } buffer;
440 char *msg, *next, *lim, **argv;
441 char ifname[IF_NAMESIZE];
442 struct prefix *prefix;
443 struct rainfo *rai;
444 struct in6_addr *addr;
445 char addrbuf[INET6_ADDRSTRLEN];
446 int prefixchange = 0, argc;
447
448 memset(&buffer, 0, sizeof(buffer));
449 n = read(rtsock, &buffer, sizeof(buffer));
450
451 /* We read the buffer first to clear the FD */
452 if (do_die)
453 return;
454
455 msg = buffer.data;
456 if (dflag > 1) {
457 syslog(LOG_DEBUG, "<%s> received a routing message "
458 "(type = %d, len = %d)", __func__, rtmsg_type(msg),
459 rtmsg_len(msg));
460 }
461 if (n > rtmsg_len(msg)) {
462 /*
463 * This usually won't happen for messages received on
464 * a routing socket.
465 */
466 if (dflag > 1)
467 syslog(LOG_DEBUG,
468 "<%s> received data length is larger than "
469 "1st routing message len. multiple messages? "
470 "read %d bytes, but 1st msg len = %d",
471 __func__, n, rtmsg_len(msg));
472 #if 0
473 /* adjust length */
474 n = rtmsg_len(msg);
475 #endif
476 }
477
478 lim = msg + n;
479 for (next = msg; next < lim; next += len) {
480 int oldifflags;
481
482 next = get_next_msg(next, lim, 0, &len,
483 RTADV_TYPE2BITMASK(RTM_ADD) |
484 RTADV_TYPE2BITMASK(RTM_DELETE) |
485 RTADV_TYPE2BITMASK(RTM_NEWADDR) |
486 RTADV_TYPE2BITMASK(RTM_DELADDR) |
487 #ifdef RTM_IFANNOUNCE
488 RTADV_TYPE2BITMASK(RTM_IFANNOUNCE) |
489 #endif
490 RTADV_TYPE2BITMASK(RTM_IFINFO));
491 if (len == 0)
492 break;
493 type = rtmsg_type(next);
494 switch (type) {
495 case RTM_ADD:
496 case RTM_DELETE:
497 ifindex = get_rtm_ifindex(next);
498 break;
499 case RTM_NEWADDR:
500 case RTM_DELADDR:
501 ifindex = get_ifam_ifindex(next);
502 break;
503 #ifdef RTM_IFANNOUNCE
504 case RTM_IFANNOUNCE:
505 ifindex = get_ifan_ifindex(next);
506 if (get_ifan_what(next) == IFAN_ARRIVAL) {
507 syslog(LOG_DEBUG,
508 "<%s> interface %s arrived",
509 __func__,
510 if_indextoname(ifindex, ifname));
511 if (if_argc == 0) {
512 getconfig(ifname, 0);
513 continue;
514 }
515 argc = if_argc;
516 argv = if_argv;
517 while (argc--) {
518 if (strcmp(ifname, *argv++) == 0) {
519 getconfig(ifname, 0);
520 break;
521 }
522 }
523 continue;
524 }
525 break;
526 #endif
527 case RTM_IFINFO:
528 ifindex = get_ifm_ifindex(next);
529 break;
530 default:
531 /* should not reach here */
532 if (dflag > 1) {
533 syslog(LOG_DEBUG,
534 "<%s:%d> unknown rtmsg %d on %s",
535 __func__, __LINE__, type,
536 if_indextoname(ifindex, ifname));
537 }
538 continue;
539 }
540
541 if ((rai = if_indextorainfo(ifindex)) == NULL) {
542 if (dflag > 1) {
543 syslog(LOG_DEBUG,
544 "<%s> route changed on "
545 "non advertising interface %s (%d)",
546 __func__,
547 if_indextoname(ifindex, ifname),
548 ifindex);
549 }
550 continue;
551 }
552 oldifflags = rai->ifflags;
553
554 switch (type) {
555 case RTM_ADD:
556 /* init ifflags because it may have changed */
557 rai->ifflags = if_getflags(ifindex, rai->ifflags);
558
559 if (sflag)
560 break; /* we aren't interested in prefixes */
561
562 addr = get_addr(msg);
563 plen = get_prefixlen(msg);
564 /* sanity check for plen */
565 /* as RFC2373, prefixlen is at least 4 */
566 if (plen < 4 || plen > 127) {
567 syslog(LOG_INFO, "<%s> new interface route's"
568 "plen %d is invalid for a prefix",
569 __func__, plen);
570 break;
571 }
572 prefix = find_prefix(rai, addr, plen);
573 if (prefix) {
574 if (prefix->timer) {
575 /*
576 * If the prefix has been invalidated,
577 * make it available again.
578 */
579 update_prefix(prefix);
580 prefixchange = 1;
581 } else if (dflag > 1) {
582 syslog(LOG_DEBUG,
583 "<%s> new prefix(%s/%d) "
584 "added on %s, "
585 "but it was already in list",
586 __func__,
587 inet_ntop(AF_INET6, addr,
588 (char *)addrbuf, INET6_ADDRSTRLEN),
589 plen, rai->ifname);
590 }
591 break;
592 }
593 make_prefix(rai, ifindex, addr, plen);
594 prefixchange = 1;
595 break;
596 case RTM_DELETE:
597 /* init ifflags because it may have changed */
598 rai->ifflags = if_getflags(ifindex, rai->ifflags);
599
600 if (sflag)
601 break;
602
603 addr = get_addr(msg);
604 plen = get_prefixlen(msg);
605 /* sanity check for plen */
606 /* as RFC2373, prefixlen is at least 4 */
607 if (plen < 4 || plen > 127) {
608 syslog(LOG_INFO,
609 "<%s> deleted interface route's "
610 "plen %d is invalid for a prefix",
611 __func__, plen);
612 break;
613 }
614 prefix = find_prefix(rai, addr, plen);
615 if (prefix == NULL) {
616 if (dflag > 1) {
617 syslog(LOG_DEBUG,
618 "<%s> prefix(%s/%d) was "
619 "deleted on %s, "
620 "but it was not in list",
621 __func__,
622 inet_ntop(AF_INET6, addr,
623 (char *)addrbuf, INET6_ADDRSTRLEN),
624 plen, rai->ifname);
625 }
626 break;
627 }
628 invalidate_prefix(prefix);
629 prefixchange = 1;
630 break;
631 case RTM_NEWADDR:
632 case RTM_DELADDR:
633 /* init ifflags because it may have changed */
634 rai->ifflags = if_getflags(ifindex, rai->ifflags);
635 break;
636 case RTM_IFINFO:
637 rai->ifflags = get_ifm_flags(next);
638 break;
639 #ifdef RTM_IFANNOUNCE
640 case RTM_IFANNOUNCE:
641 if (get_ifan_what(next) == IFAN_DEPARTURE) {
642 syslog(LOG_DEBUG,
643 "<%s> interface %s departed",
644 __func__, rai->ifname);
645 TAILQ_REMOVE(&ralist, rai, next);
646 if (rai->leaving)
647 free_rainfo(rai->leaving);
648 free_rainfo(rai);
649 continue;
650 }
651 break;
652 #endif
653 default:
654 /* should not reach here */
655 if (dflag > 1) {
656 syslog(LOG_DEBUG,
657 "<%s:%d> unknown rtmsg %d on %s",
658 __func__, __LINE__, type,
659 if_indextoname(ifindex, ifname));
660 }
661 return;
662 }
663
664 /* check if an interface flag is changed */
665 if ((oldifflags & IFF_UP) != 0 && /* UP to DOWN */
666 (rai->ifflags & IFF_UP) == 0) {
667 syslog(LOG_INFO,
668 "<%s> interface %s becomes down. stop timer.",
669 __func__, rai->ifname);
670 rtadvd_remove_timer(&rai->timer);
671 } else if ((oldifflags & IFF_UP) == 0 && /* DOWN to UP */
672 (rai->ifflags & IFF_UP) != 0) {
673 syslog(LOG_INFO,
674 "<%s> interface %s becomes up. restart timer.",
675 __func__, rai->ifname);
676
677 rai->initcounter = 0; /* reset the counter */
678 rai->waiting = 0; /* XXX */
679 rtadvd_remove_timer(&rai->timer);
680 rai->timer = rtadvd_add_timer(ra_timeout,
681 ra_timer_update, rai, rai);
682 ra_timer_update((void *)rai, &rai->timer->tm);
683 rtadvd_set_timer(&rai->timer->tm, rai->timer);
684 } else if (prefixchange && rai->ifflags & IFF_UP) {
685 /*
686 * An advertised prefix has been added or invalidated.
687 * Will notice the change in a short delay.
688 */
689 rai->initcounter = 0;
690 ra_timer_set_short_delay(rai);
691 }
692 }
693
694 return;
695 }
696
697 void
rtadvd_input(void)698 rtadvd_input(void)
699 {
700 ssize_t i;
701 int *hlimp = NULL;
702 #ifdef OLDRAWSOCKET
703 struct ip6_hdr *ip;
704 #endif
705 struct icmp6_hdr *icp;
706 int ifindex = 0;
707 struct cmsghdr *cm;
708 struct in6_pktinfo *pi = NULL;
709 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
710 struct in6_addr dst = in6addr_any;
711 struct rainfo *rai;
712
713 /*
714 * Get message. We reset msg_controllen since the field could
715 * be modified if we had received a message before setting
716 * receive options.
717 */
718 rcvmhdr.msg_controllen = rcvcmsgbuflen;
719 if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
720 return;
721
722 /* We read the buffer first to clear the FD */
723 if (do_die)
724 return;
725
726 /* extract optional information via Advanced API */
727 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
728 cm;
729 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
730 if (cm->cmsg_level == IPPROTO_IPV6 &&
731 cm->cmsg_type == IPV6_PKTINFO &&
732 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
733 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
734 ifindex = pi->ipi6_ifindex;
735 dst = pi->ipi6_addr;
736 }
737 if (cm->cmsg_level == IPPROTO_IPV6 &&
738 cm->cmsg_type == IPV6_HOPLIMIT &&
739 cm->cmsg_len == CMSG_LEN(sizeof(int)))
740 hlimp = (int *)CMSG_DATA(cm);
741 }
742 if (ifindex == 0) {
743 syslog(LOG_ERR,
744 "<%s> failed to get receiving interface",
745 __func__);
746 return;
747 }
748 if (hlimp == NULL) {
749 syslog(LOG_ERR,
750 "<%s> failed to get receiving hop limit",
751 __func__);
752 return;
753 }
754
755 if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == NULL) {
756 if (dflag > 1) {
757 syslog(LOG_DEBUG,
758 "<%s> received data for non advertising "
759 "interface (%s)",
760 __func__,
761 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
762 }
763 return;
764 }
765 /*
766 * If we happen to receive data on an interface which is now down,
767 * just discard the data.
768 */
769 if ((rai->ifflags & IFF_UP) == 0) {
770 syslog(LOG_INFO,
771 "<%s> received data on a disabled interface (%s)",
772 __func__,
773 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
774 return;
775 }
776
777 #ifdef OLDRAWSOCKET
778 if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
779 syslog(LOG_ERR,
780 "<%s> packet size(%d) is too short",
781 __func__, i);
782 return;
783 }
784
785 ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
786 icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
787 #else
788 if ((size_t)i < sizeof(struct icmp6_hdr)) {
789 syslog(LOG_ERR,
790 "<%s> packet size(%zd) is too short",
791 __func__, i);
792 return;
793 }
794
795 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
796 #endif
797
798 switch (icp->icmp6_type) {
799 case ND_ROUTER_SOLICIT:
800 /*
801 * Message verification - RFC-2461 6.1.1
802 * XXX: these checks must be done in the kernel as well,
803 * but we can't completely rely on them.
804 */
805 if (*hlimp != 255) {
806 syslog(LOG_NOTICE,
807 "<%s> RS with invalid hop limit(%d) "
808 "received from %s on %s",
809 __func__, *hlimp,
810 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
811 INET6_ADDRSTRLEN),
812 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
813 return;
814 }
815 if (icp->icmp6_code) {
816 syslog(LOG_NOTICE,
817 "<%s> RS with invalid ICMP6 code(%d) "
818 "received from %s on %s",
819 __func__, icp->icmp6_code,
820 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
821 INET6_ADDRSTRLEN),
822 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
823 return;
824 }
825 if ((size_t)i < sizeof(struct nd_router_solicit)) {
826 syslog(LOG_NOTICE,
827 "<%s> RS from %s on %s does not have enough "
828 "length (len = %zd)",
829 __func__,
830 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
831 INET6_ADDRSTRLEN),
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-2461 6.1.2
840 * XXX: there's a same dilemma as above...
841 */
842 if (*hlimp != 255) {
843 syslog(LOG_NOTICE,
844 "<%s> RA with invalid hop limit(%d) "
845 "received from %s on %s",
846 __func__, *hlimp,
847 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
848 INET6_ADDRSTRLEN),
849 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
850 return;
851 }
852 if (icp->icmp6_code) {
853 syslog(LOG_NOTICE,
854 "<%s> RA with invalid ICMP6 code(%d) "
855 "received from %s on %s",
856 __func__, icp->icmp6_code,
857 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
858 INET6_ADDRSTRLEN),
859 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
860 return;
861 }
862 if ((size_t)i < sizeof(struct nd_router_advert)) {
863 syslog(LOG_NOTICE,
864 "<%s> RA from %s on %s does not have enough "
865 "length (len = %zd)",
866 __func__,
867 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
868 INET6_ADDRSTRLEN),
869 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
870 return;
871 }
872 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
873 break;
874 case ICMP6_ROUTER_RENUMBERING:
875 if (accept_rr == 0) {
876 syslog(LOG_ERR, "<%s> received a router renumbering "
877 "message, but not allowed to be accepted",
878 __func__);
879 break;
880 }
881 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
882 &dst);
883 break;
884 default:
885 /*
886 * Note that this case is POSSIBLE, especially just
887 * after invocation of the daemon. This is because we
888 * could receive message after opening the socket and
889 * before setting ICMP6 type filter(see sock_open()).
890 */
891 syslog(LOG_ERR, "<%s> invalid icmp type(%d)",
892 __func__, icp->icmp6_type);
893 return;
894 }
895
896 return;
897 }
898
899 static void
rs_input(int len,struct nd_router_solicit * rs,struct in6_pktinfo * pi,struct sockaddr_in6 * from)900 rs_input(int len, struct nd_router_solicit *rs,
901 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
902 {
903 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
904 union nd_opts ndopts;
905 struct rainfo *rai;
906 struct soliciter *sol;
907
908 syslog(LOG_DEBUG,
909 "<%s> RS received from %s on %s",
910 __func__,
911 inet_ntop(AF_INET6, &from->sin6_addr,
912 ntopbuf, INET6_ADDRSTRLEN),
913 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
914
915 /* ND option check */
916 memset(&ndopts, 0, sizeof(ndopts));
917 TAILQ_INIT(&ndopts.nd_opts_list);
918 if (nd6_options((struct nd_opt_hdr *)(rs + 1),
919 len - sizeof(struct nd_router_solicit),
920 &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
921 syslog(LOG_INFO,
922 "<%s> ND option check failed for an RS from %s on %s",
923 __func__,
924 inet_ntop(AF_INET6, &from->sin6_addr,
925 ntopbuf, INET6_ADDRSTRLEN),
926 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
927 return;
928 }
929
930 /*
931 * If the IP source address is the unspecified address, there
932 * must be no source link-layer address option in the message.
933 * (RFC-2461 6.1.1)
934 */
935 if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
936 ndopts.nd_opts_src_lladdr) {
937 syslog(LOG_INFO,
938 "<%s> RS from unspecified src on %s has a link-layer"
939 " address option",
940 __func__,
941 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
942 goto done;
943 }
944
945 if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == NULL) {
946 syslog(LOG_INFO,
947 "<%s> RS received on non advertising interface(%s)",
948 __func__,
949 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
950 goto done;
951 }
952
953 if (rai->leaving) {
954 syslog(LOG_INFO,
955 "<%s> RS received on reconfiguring advertising interface(%s)",
956 __func__, rai->ifname);
957 goto done;
958 }
959
960 rai->rsinput++; /* increment statistics */
961
962 /*
963 * Decide whether to send RA according to the rate-limit
964 * consideration.
965 */
966
967 /* record sockaddr waiting for RA, if possible */
968 sol = malloc(sizeof(*sol));
969 if (sol) {
970 sol->addr = *from;
971 /* XXX RFC2553 need clarification on flowinfo */
972 sol->addr.sin6_flowinfo = 0;
973 TAILQ_INSERT_HEAD(&rai->soliciter, sol, next);
974 }
975
976 /*
977 * If there is already a waiting RS packet, don't
978 * update the timer.
979 */
980 if (rai->waiting++)
981 goto done;
982
983 ra_timer_set_short_delay(rai);
984
985 done:
986 free_ndopts(&ndopts);
987 return;
988 }
989
990 void
ra_timer_set_short_delay(struct rainfo * rai)991 ra_timer_set_short_delay(struct rainfo *rai)
992 {
993 long delay; /* must not be greater than 1000000 */
994 struct timespec interval, now, min_delay, tm_tmp, *rest;
995
996 /*
997 * Compute a random delay. If the computed value
998 * corresponds to a time later than the time the next
999 * multicast RA is scheduled to be sent, ignore the random
1000 * delay and send the advertisement at the
1001 * already-scheduled time. RFC2461 6.2.6
1002 */
1003 delay = arc4random() % MAX_RA_DELAY_TIME;
1004 interval.tv_sec = 0;
1005 interval.tv_nsec = delay;
1006 rest = rtadvd_timer_rest(rai->timer);
1007 if (timespeccmp(rest, &interval, <)) {
1008 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1009 "the rest of current timer", __func__);
1010 interval = *rest;
1011 }
1012
1013 /*
1014 * If we sent a multicast Router Advertisement within
1015 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1016 * the advertisement to be sent at a time corresponding to
1017 * MIN_DELAY_BETWEEN_RAS plus the random value after the
1018 * previous advertisement was sent.
1019 */
1020 clock_gettime(CLOCK_MONOTONIC, &now);
1021 timespecsub(&now, &rai->lastsent, &tm_tmp);
1022 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1023 min_delay.tv_nsec = 0;
1024 if (timespeccmp(&tm_tmp, &min_delay, <)) {
1025 timespecsub(&min_delay, &tm_tmp, &min_delay);
1026 timespecadd(&min_delay, &interval, &interval);
1027 }
1028 rtadvd_set_timer(&interval, rai->timer);
1029 }
1030
1031 static void
ra_input(int len,struct nd_router_advert * ra,struct in6_pktinfo * pi,struct sockaddr_in6 * from)1032 ra_input(int len, struct nd_router_advert *ra,
1033 struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1034 {
1035 struct rainfo *rai;
1036 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
1037 union nd_opts ndopts;
1038 const char *on_off[] = {"OFF", "ON"};
1039 uint32_t reachabletime, retranstimer, mtu;
1040 struct nd_optlist *optp;
1041 int inconsistent = 0;
1042
1043 syslog(LOG_DEBUG,
1044 "<%s> RA received from %s on %s",
1045 __func__,
1046 inet_ntop(AF_INET6, &from->sin6_addr,
1047 ntopbuf, INET6_ADDRSTRLEN),
1048 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1049
1050 /* ND option check */
1051 memset(&ndopts, 0, sizeof(ndopts));
1052 TAILQ_INIT(&ndopts.nd_opts_list);
1053 if (nd6_options((struct nd_opt_hdr *)(ra + 1),
1054 len - sizeof(struct nd_router_advert),
1055 &ndopts, NDOPT_FLAG_SRCLINKADDR |
1056 NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1057 NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL))
1058 {
1059 syslog(LOG_INFO,
1060 "<%s> ND option check failed for an RA from %s on %s",
1061 __func__,
1062 inet_ntop(AF_INET6, &from->sin6_addr,
1063 ntopbuf, INET6_ADDRSTRLEN),
1064 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1065 return;
1066 }
1067
1068 /*
1069 * RA consistency check according to RFC-2461 6.2.7
1070 */
1071 if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
1072 syslog(LOG_INFO,
1073 "<%s> received RA from %s on non-advertising"
1074 " interface(%s)",
1075 __func__,
1076 inet_ntop(AF_INET6, &from->sin6_addr,
1077 ntopbuf, INET6_ADDRSTRLEN),
1078 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1079 goto done;
1080 }
1081 if (rai->leaving) {
1082 syslog(LOG_DEBUG,
1083 "<%s> received RA on re-configuring interface (%s)",
1084 __func__, rai->ifname);
1085 goto done;
1086 }
1087 rai->rainput++; /* increment statistics */
1088
1089 /* Cur Hop Limit value */
1090 if (ra->nd_ra_curhoplimit && rai->hoplimit &&
1091 ra->nd_ra_curhoplimit != rai->hoplimit) {
1092 syslog(LOG_INFO,
1093 "<%s> CurHopLimit inconsistent on %s:"
1094 " %d from %s, %d from us",
1095 __func__,
1096 rai->ifname,
1097 ra->nd_ra_curhoplimit,
1098 inet_ntop(AF_INET6, &from->sin6_addr,
1099 ntopbuf, INET6_ADDRSTRLEN),
1100 rai->hoplimit);
1101 inconsistent++;
1102 }
1103 /* M flag */
1104 if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1105 rai->managedflg) {
1106 syslog(LOG_INFO,
1107 "<%s> M flag inconsistent on %s:"
1108 " %s from %s, %s from us",
1109 __func__,
1110 rai->ifname,
1111 on_off[!rai->managedflg],
1112 inet_ntop(AF_INET6, &from->sin6_addr,
1113 ntopbuf, INET6_ADDRSTRLEN),
1114 on_off[rai->managedflg]);
1115 inconsistent++;
1116 }
1117 /* O flag */
1118 if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1119 rai->otherflg) {
1120 syslog(LOG_INFO,
1121 "<%s> O flag inconsistent on %s:"
1122 " %s from %s, %s from us",
1123 __func__,
1124 rai->ifname,
1125 on_off[!rai->otherflg],
1126 inet_ntop(AF_INET6, &from->sin6_addr,
1127 ntopbuf, INET6_ADDRSTRLEN),
1128 on_off[rai->otherflg]);
1129 inconsistent++;
1130 }
1131 /* Reachable Time */
1132 reachabletime = ntohl(ra->nd_ra_reachable);
1133 if (reachabletime && rai->reachabletime &&
1134 reachabletime != rai->reachabletime) {
1135 syslog(LOG_INFO,
1136 "<%s> ReachableTime inconsistent on %s:"
1137 " %d from %s, %d from us",
1138 __func__,
1139 rai->ifname,
1140 reachabletime,
1141 inet_ntop(AF_INET6, &from->sin6_addr,
1142 ntopbuf, INET6_ADDRSTRLEN),
1143 rai->reachabletime);
1144 inconsistent++;
1145 }
1146 /* Retrans Timer */
1147 retranstimer = ntohl(ra->nd_ra_retransmit);
1148 if (retranstimer && rai->retranstimer &&
1149 retranstimer != rai->retranstimer) {
1150 syslog(LOG_INFO,
1151 "<%s> RetranceTimer inconsistent on %s:"
1152 " %d from %s, %d from us",
1153 __func__,
1154 rai->ifname,
1155 retranstimer,
1156 inet_ntop(AF_INET6, &from->sin6_addr,
1157 ntopbuf, INET6_ADDRSTRLEN),
1158 rai->retranstimer);
1159 inconsistent++;
1160 }
1161 /* Values in the MTU options */
1162 if (ndopts.nd_opts_mtu) {
1163 mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
1164 if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
1165 syslog(LOG_INFO,
1166 "<%s> MTU option value inconsistent on %s:"
1167 " %d from %s, %d from us",
1168 __func__,
1169 rai->ifname, mtu,
1170 inet_ntop(AF_INET6, &from->sin6_addr,
1171 ntopbuf, INET6_ADDRSTRLEN),
1172 rai->linkmtu);
1173 inconsistent++;
1174 }
1175 }
1176 /* Preferred and Valid Lifetimes for prefixes */
1177 if (ndopts.nd_opts_pi)
1178 if (prefix_check(ndopts.nd_opts_pi, rai, from))
1179 inconsistent++;
1180 TAILQ_FOREACH(optp, &ndopts.nd_opts_list, next)
1181 if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
1182 rai, from))
1183 inconsistent++;
1184
1185 if (inconsistent)
1186 rai->rainconsistent++;
1187
1188 done:
1189 free_ndopts(&ndopts);
1190 return;
1191 }
1192
1193 /* return a non-zero value if the received prefix is inconsitent with ours */
1194 static int
prefix_check(struct nd_opt_prefix_info * pinfo,struct rainfo * rai,struct sockaddr_in6 * from)1195 prefix_check(struct nd_opt_prefix_info *pinfo,
1196 struct rainfo *rai, struct sockaddr_in6 *from)
1197 {
1198 uint32_t preferred_time, valid_time;
1199 struct prefix *pp;
1200 int inconsistent = 0;
1201 char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
1202 struct timespec now;
1203
1204 #if 0 /* impossible */
1205 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1206 return(0);
1207 #endif
1208
1209 /*
1210 * log if the adveritsed prefix has link-local scope(sanity check?)
1211 */
1212 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
1213 syslog(LOG_INFO,
1214 "<%s> link-local prefix %s/%d is advertised "
1215 "from %s on %s",
1216 __func__,
1217 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1218 prefixbuf, INET6_ADDRSTRLEN),
1219 pinfo->nd_opt_pi_prefix_len,
1220 inet_ntop(AF_INET6, &from->sin6_addr,
1221 ntopbuf, INET6_ADDRSTRLEN),
1222 rai->ifname);
1223 }
1224
1225 if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1226 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1227 syslog(LOG_INFO,
1228 "<%s> prefix %s/%d from %s on %s is not in our list",
1229 __func__,
1230 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1231 prefixbuf, INET6_ADDRSTRLEN),
1232 pinfo->nd_opt_pi_prefix_len,
1233 inet_ntop(AF_INET6, &from->sin6_addr,
1234 ntopbuf, INET6_ADDRSTRLEN),
1235 rai->ifname);
1236 return(0);
1237 }
1238
1239 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1240 if (pp->pltimeexpire) {
1241 /*
1242 * The lifetime is decremented in real time, so we should
1243 * compare the expiration time.
1244 * (RFC 2461 Section 6.2.7.)
1245 * XXX: can we really expect that all routers on the link
1246 * have synchronized clocks?
1247 */
1248 clock_gettime(CLOCK_MONOTONIC, &now);
1249 preferred_time += now.tv_sec;
1250
1251 if (!pp->timer && rai->clockskew &&
1252 llabs((long long)preferred_time - pp->pltimeexpire) > rai->clockskew) {
1253 syslog(LOG_INFO,
1254 "<%s> preferred lifetime for %s/%d"
1255 " (decr. in real time) inconsistent on %s:"
1256 " %d from %s, %ld from us",
1257 __func__,
1258 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1259 prefixbuf, INET6_ADDRSTRLEN),
1260 pinfo->nd_opt_pi_prefix_len,
1261 rai->ifname, preferred_time,
1262 inet_ntop(AF_INET6, &from->sin6_addr,
1263 ntopbuf, INET6_ADDRSTRLEN),
1264 pp->pltimeexpire);
1265 inconsistent++;
1266 }
1267 } else if (!pp->timer && preferred_time != pp->preflifetime) {
1268 syslog(LOG_INFO,
1269 "<%s> preferred lifetime for %s/%d"
1270 " inconsistent on %s:"
1271 " %d from %s, %d from us",
1272 __func__,
1273 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1274 prefixbuf, INET6_ADDRSTRLEN),
1275 pinfo->nd_opt_pi_prefix_len,
1276 rai->ifname, preferred_time,
1277 inet_ntop(AF_INET6, &from->sin6_addr,
1278 ntopbuf, INET6_ADDRSTRLEN),
1279 pp->preflifetime);
1280 }
1281
1282 valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1283 if (pp->vltimeexpire) {
1284 clock_gettime(CLOCK_MONOTONIC, &now);
1285 valid_time += now.tv_sec;
1286
1287 if (!pp->timer && rai->clockskew &&
1288 llabs((long long)valid_time - pp->vltimeexpire) > rai->clockskew) {
1289 syslog(LOG_INFO,
1290 "<%s> valid lifetime for %s/%d"
1291 " (decr. in real time) inconsistent on %s:"
1292 " %d from %s, %ld from us",
1293 __func__,
1294 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1295 prefixbuf, INET6_ADDRSTRLEN),
1296 pinfo->nd_opt_pi_prefix_len,
1297 rai->ifname, preferred_time,
1298 inet_ntop(AF_INET6, &from->sin6_addr,
1299 ntopbuf, INET6_ADDRSTRLEN),
1300 pp->vltimeexpire);
1301 inconsistent++;
1302 }
1303 } else if (!pp->timer && valid_time != pp->validlifetime) {
1304 syslog(LOG_INFO,
1305 "<%s> valid lifetime for %s/%d"
1306 " inconsistent on %s:"
1307 " %d from %s, %d from us",
1308 __func__,
1309 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1310 prefixbuf, INET6_ADDRSTRLEN),
1311 pinfo->nd_opt_pi_prefix_len,
1312 rai->ifname, valid_time,
1313 inet_ntop(AF_INET6, &from->sin6_addr,
1314 ntopbuf, INET6_ADDRSTRLEN),
1315 pp->validlifetime);
1316 inconsistent++;
1317 }
1318
1319 return(inconsistent);
1320 }
1321
1322 struct prefix *
find_prefix(struct rainfo * rai,struct in6_addr * prefix,int plen)1323 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1324 {
1325 struct prefix *pp;
1326 int bytelen, bitlen;
1327 unsigned char bitmask;
1328
1329 TAILQ_FOREACH(pp, &rai->prefix, next) {
1330 if (plen != pp->prefixlen)
1331 continue;
1332 bytelen = plen / 8;
1333 bitlen = plen % 8;
1334 bitmask = 0xff << (8 - bitlen);
1335 if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1336 continue;
1337 if (bitlen == 0 ||
1338 ((prefix->s6_addr[bytelen] & bitmask) ==
1339 (pp->prefix.s6_addr[bytelen] & bitmask))) {
1340 return(pp);
1341 }
1342 }
1343
1344 return(NULL);
1345 }
1346
1347 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1348 int
prefix_match(struct in6_addr * p0,int plen0,struct in6_addr * p1,int plen1)1349 prefix_match(struct in6_addr *p0, int plen0,
1350 struct in6_addr *p1, int plen1)
1351 {
1352 int bytelen, bitlen;
1353 unsigned char bitmask;
1354
1355 if (plen0 < plen1)
1356 return(0);
1357 bytelen = plen1 / 8;
1358 bitlen = plen1 % 8;
1359 bitmask = 0xff << (8 - bitlen);
1360 if (memcmp((void *)p0, (void *)p1, bytelen))
1361 return(0);
1362 if (bitlen == 0 ||
1363 ((p0->s6_addr[bytelen] & bitmask) ==
1364 (p1->s6_addr[bytelen] & bitmask))) {
1365 return(1);
1366 }
1367
1368 return(0);
1369 }
1370
1371 static int
nd6_options(struct nd_opt_hdr * hdr,int limit,union nd_opts * ndopts,uint32_t optflags)1372 nd6_options(struct nd_opt_hdr *hdr, int limit,
1373 union nd_opts *ndopts, uint32_t optflags)
1374 {
1375 int optlen = 0;
1376
1377 for (; limit > 0; limit -= optlen) {
1378 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1379 syslog(LOG_INFO, "<%s> short option header", __func__);
1380 goto bad;
1381 }
1382
1383 hdr = (struct nd_opt_hdr *)((char *)hdr + optlen);
1384 if (hdr->nd_opt_len == 0) {
1385 syslog(LOG_INFO,
1386 "<%s> bad ND option length(0) (type = %d)",
1387 __func__, hdr->nd_opt_type);
1388 goto bad;
1389 }
1390 optlen = hdr->nd_opt_len << 3;
1391 if (optlen > limit) {
1392 syslog(LOG_INFO, "<%s> short option", __func__);
1393 goto bad;
1394 }
1395
1396 if (hdr->nd_opt_type > ND_OPT_MTU &&
1397 hdr->nd_opt_type != ND_OPT_RDNSS &&
1398 hdr->nd_opt_type != ND_OPT_DNSSL)
1399 {
1400 syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1401 __func__, hdr->nd_opt_type);
1402 continue;
1403 }
1404
1405 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1406 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1407 __func__, hdr->nd_opt_type);
1408 continue;
1409 }
1410
1411 /*
1412 * Option length check. Do it here for all fixed-length
1413 * options.
1414 */
1415 if ((hdr->nd_opt_type == ND_OPT_MTU &&
1416 (optlen != sizeof(struct nd_opt_mtu))) ||
1417 ((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION &&
1418 optlen != sizeof(struct nd_opt_prefix_info))) ||
1419 (hdr->nd_opt_type == ND_OPT_RDNSS &&
1420 ((optlen < (int)sizeof(struct nd_opt_rdnss) ||
1421 (optlen - sizeof(struct nd_opt_rdnss)) % 16 != 0))) ||
1422 (hdr->nd_opt_type == ND_OPT_DNSSL &&
1423 optlen < (int)sizeof(struct nd_opt_dnssl)))
1424 {
1425 syslog(LOG_INFO, "<%s> invalid option length",
1426 __func__);
1427 continue;
1428 }
1429
1430 switch (hdr->nd_opt_type) {
1431 case ND_OPT_TARGET_LINKADDR:
1432 case ND_OPT_REDIRECTED_HEADER:
1433 case ND_OPT_RDNSS:
1434 case ND_OPT_DNSSL:
1435 break; /* we don't care about these options */
1436 case ND_OPT_SOURCE_LINKADDR:
1437 case ND_OPT_MTU:
1438 if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1439 syslog(LOG_INFO,
1440 "<%s> duplicated ND option (type = %d)",
1441 __func__, hdr->nd_opt_type);
1442 }
1443 ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1444 break;
1445 case ND_OPT_PREFIX_INFORMATION:
1446 {
1447 struct nd_optlist *pfxlist;
1448
1449 if (ndopts->nd_opts_pi == 0) {
1450 ndopts->nd_opts_pi =
1451 (struct nd_opt_prefix_info *)hdr;
1452 continue;
1453 }
1454 if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1455 syslog(LOG_ERR, "<%s> can't allocate memory",
1456 __func__);
1457 goto bad;
1458 }
1459 pfxlist->opt = hdr;
1460 TAILQ_INSERT_TAIL(&ndopts->nd_opts_list, pfxlist, next);
1461
1462 break;
1463 }
1464 default: /* impossible */
1465 break;
1466 }
1467 }
1468
1469 return(0);
1470
1471 bad:
1472 free_ndopts(ndopts);
1473
1474 return(-1);
1475 }
1476
1477 static void
free_ndopts(union nd_opts * ndopts)1478 free_ndopts(union nd_opts *ndopts)
1479 {
1480 struct nd_optlist *opt;
1481
1482 while ((opt = TAILQ_FIRST(&ndopts->nd_opts_list)) != NULL) {
1483 TAILQ_REMOVE(&ndopts->nd_opts_list, opt, next);
1484 free(opt);
1485 }
1486 }
1487
1488 void
sock_open(void)1489 sock_open(void)
1490 {
1491 struct icmp6_filter filt;
1492 struct ipv6_mreq mreq;
1493 struct rainfo *ra;
1494 int on;
1495 /* XXX: should be max MTU attached to the node */
1496 static unsigned char answer[1500];
1497
1498 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1499 CMSG_SPACE(sizeof(int));
1500 rcvcmsgbuf = malloc(rcvcmsgbuflen);
1501 if (rcvcmsgbuf == NULL) {
1502 syslog(LOG_ERR, "<%s> malloc: %m", __func__);
1503 exit(1);
1504 }
1505
1506 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo));
1507 sndcmsgbuf = malloc(sndcmsgbuflen);
1508 if (sndcmsgbuf == NULL) {
1509 syslog(LOG_ERR, "<%s> malloc: %m", __func__);
1510 exit(1);
1511 }
1512
1513 if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1514 syslog(LOG_ERR, "<%s> socket: %m", __func__);
1515 exit(1);
1516 }
1517
1518 /* RFC 4861 Section 4.2 */
1519 on = 255;
1520 if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &on,
1521 sizeof(on)) == -1) {
1522 syslog(LOG_ERR, "<%s> IPV6_MULTICAST_HOPS: %m", __func__);
1523 exit(1);
1524 }
1525
1526 /* specify to tell receiving interface */
1527 on = 1;
1528 #ifdef IPV6_RECVPKTINFO
1529 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1530 sizeof(on)) < 0) {
1531 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %m", __func__);
1532 exit(1);
1533 }
1534 #else /* old adv. API */
1535 if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1536 sizeof(on)) < 0) {
1537 syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %m", __func__);
1538 exit(1);
1539 }
1540 #endif
1541
1542 on = 1;
1543 /* specify to tell value of hoplimit field of received IP6 hdr */
1544 #ifdef IPV6_RECVHOPLIMIT
1545 if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1546 sizeof(on)) < 0) {
1547 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %m", __func__);
1548 exit(1);
1549 }
1550 #else /* old adv. API */
1551 if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1552 sizeof(on)) < 0) {
1553 syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %m", __func__);
1554 exit(1);
1555 }
1556 #endif
1557
1558 ICMP6_FILTER_SETBLOCKALL(&filt);
1559 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1560 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1561 if (accept_rr)
1562 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1563 if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1564 sizeof(filt)) < 0) {
1565 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %m", __func__);
1566 exit(1);
1567 }
1568
1569 /*
1570 * join all routers multicast address on each advertising interface.
1571 */
1572 if (inet_pton(AF_INET6, ALLROUTERS_LINK,
1573 mreq.ipv6mr_multiaddr.s6_addr) != 1)
1574 {
1575 syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1576 __func__);
1577 exit(1);
1578 }
1579 TAILQ_FOREACH(ra, &ralist, next) {
1580 mreq.ipv6mr_interface = ra->ifindex;
1581 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
1582 sizeof(mreq)) < 0) {
1583 syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP(link) on %s: %m",
1584 __func__, ra->ifname);
1585 exit(1);
1586 }
1587 }
1588
1589 /*
1590 * When attending router renumbering, join all-routers site-local
1591 * multicast group.
1592 */
1593 if (accept_rr) {
1594 if (inet_pton(AF_INET6, ALLROUTERS_SITE,
1595 mreq.ipv6mr_multiaddr.s6_addr) != 1)
1596 {
1597 syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1598 __func__);
1599 exit(1);
1600 }
1601 ra = TAILQ_FIRST(&ralist);
1602 if (mcastif) {
1603 if ((mreq.ipv6mr_interface = if_nametoindex(mcastif))
1604 == 0) {
1605 syslog(LOG_ERR,
1606 "<%s> invalid interface: %s",
1607 __func__, mcastif);
1608 exit(1);
1609 }
1610 } else
1611 mreq.ipv6mr_interface = ra->ifindex;
1612 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1613 &mreq, sizeof(mreq)) < 0) {
1614 syslog(LOG_ERR,
1615 "<%s> IPV6_JOIN_GROUP(site) on %s: %m",
1616 __func__,
1617 mcastif ? mcastif : ra->ifname);
1618 exit(1);
1619 }
1620 }
1621
1622 /* initialize msghdr for receiving packets */
1623 rcviov[0].iov_base = answer;
1624 rcviov[0].iov_len = sizeof(answer);
1625 rcvmhdr.msg_name = &rcvfrom;
1626 rcvmhdr.msg_namelen = sizeof(rcvfrom);
1627 rcvmhdr.msg_iov = rcviov;
1628 rcvmhdr.msg_iovlen = 1;
1629 rcvmhdr.msg_control = rcvcmsgbuf;
1630 rcvmhdr.msg_controllen = rcvcmsgbuflen;
1631
1632 /* initialize msghdr for sending packets */
1633 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1634 sndmhdr.msg_iov = sndiov;
1635 sndmhdr.msg_iovlen = 1;
1636 sndmhdr.msg_control = (void *)sndcmsgbuf;
1637 sndmhdr.msg_controllen = sndcmsgbuflen;
1638
1639 return;
1640 }
1641
1642 /* open a routing socket to watch the routing table */
1643 static void
rtsock_open(void)1644 rtsock_open(void)
1645 {
1646 if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1647 syslog(LOG_ERR, "<%s> socket: %m", __func__);
1648 exit(1);
1649 }
1650 }
1651
1652 struct rainfo *
if_indextorainfo(unsigned int idx)1653 if_indextorainfo(unsigned int idx)
1654 {
1655 struct rainfo *rai;
1656
1657 TAILQ_FOREACH(rai, &ralist, next) {
1658 if (rai->ifindex == idx)
1659 return(rai);
1660 }
1661
1662 return(NULL); /* search failed */
1663 }
1664
1665 struct rainfo *
ra_output(struct rainfo * rai)1666 ra_output(struct rainfo *rai)
1667 {
1668 int i;
1669 struct cmsghdr *cm;
1670 struct in6_pktinfo *pi;
1671 struct soliciter *sol;
1672
1673 if ((rai->ifflags & IFF_UP) == 0) {
1674 syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1675 __func__, rai->ifname);
1676 return NULL;
1677 }
1678
1679 make_packet(rai); /* XXX: inefficient */
1680
1681 sndmhdr.msg_name = (void *)&sin6_linklocal_allnodes;
1682 sndmhdr.msg_iov[0].iov_base = (void *)rai->ra_data;
1683 sndmhdr.msg_iov[0].iov_len = rai->ra_datalen;
1684
1685 cm = CMSG_FIRSTHDR(&sndmhdr);
1686 /* specify the outgoing interface */
1687 cm->cmsg_level = IPPROTO_IPV6;
1688 cm->cmsg_type = IPV6_PKTINFO;
1689 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1690 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1691 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
1692 pi->ipi6_ifindex = rai->ifindex;
1693
1694 syslog(LOG_DEBUG,
1695 "<%s> send RA on %s, # of waitings = %d",
1696 __func__, rai->ifname, rai->waiting);
1697
1698 i = sendmsg(sock, &sndmhdr, 0);
1699
1700 if (i < 0 || (size_t)i != rai->ra_datalen) {
1701 if (i < 0) {
1702 syslog(LOG_ERR, "<%s> sendmsg on %s: %m",
1703 __func__, rai->ifname);
1704 }
1705 }
1706
1707 /*
1708 * unicast advertisements
1709 * XXX commented out. reason: though spec does not forbit it, unicast
1710 * advert does not really help
1711 */
1712 while ((sol = TAILQ_FIRST(&rai->soliciter)) != NULL) {
1713 #if 0
1714 sndmhdr.msg_name = (void *)&sol->addr;
1715 i = sendmsg(sock, &sndmhdr, 0);
1716 if (i < 0 || i != rai->ra_datalen) {
1717 if (i < 0) {
1718 syslog(LOG_ERR,
1719 "<%s> unicast sendmsg on %s: %m",
1720 __func__, rai->ifname);
1721 }
1722 }
1723 #endif
1724 TAILQ_REMOVE(&rai->soliciter, sol, next);
1725 free(sol);
1726 }
1727
1728 if (rai->leaving_adv > 0) {
1729 if (--(rai->leaving_adv) == 0) {
1730 /* leaving for ourself means we're shutting down */
1731 if (rai->leaving_for == rai) {
1732 TAILQ_REMOVE(&ralist, rai, next);
1733 free_rainfo(rai);
1734 return NULL;
1735 }
1736 syslog(LOG_DEBUG,
1737 "<%s> expired RA,"
1738 " new config active for interface (%s)",
1739 __func__, rai->ifname);
1740 rai->leaving_for->timer = rtadvd_add_timer(ra_timeout,
1741 ra_timer_update,
1742 rai->leaving_for, rai->leaving_for);
1743 ra_timer_set_short_delay(rai->leaving_for);
1744 rai->leaving_for->leaving = NULL;
1745 free_rainfo(rai);
1746 return NULL;
1747 }
1748 }
1749
1750 /* update counter */
1751 if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1752 rai->initcounter++;
1753 rai->raoutput++;
1754
1755 /* update timestamp */
1756 clock_gettime(CLOCK_MONOTONIC, &rai->lastsent);
1757
1758 /* reset waiting conter */
1759 rai->waiting = 0;
1760
1761 return rai;
1762 }
1763
1764 /* process RA timer */
1765 struct rtadvd_timer *
ra_timeout(void * data)1766 ra_timeout(void *data)
1767 {
1768 struct rainfo *rai = (struct rainfo *)data;
1769
1770 #ifdef notyet
1771 /* if necessary, reconstruct the packet. */
1772 #endif
1773
1774 syslog(LOG_DEBUG,
1775 "<%s> RA timer on %s is expired",
1776 __func__, rai->ifname);
1777
1778 if (ra_output(rai))
1779 return(rai->timer);
1780 return NULL;
1781 }
1782
1783 /* update RA timer */
1784 void
ra_timer_update(void * data,struct timespec * tm)1785 ra_timer_update(void *data, struct timespec *tm)
1786 {
1787 struct rainfo *rai = (struct rainfo *)data;
1788 long interval;
1789
1790 /*
1791 * Whenever a multicast advertisement is sent from an interface,
1792 * the timer is reset to a uniformly-distributed random value
1793 * between the interface's configured MinRtrAdvInterval and
1794 * MaxRtrAdvInterval (RFC2461 6.2.4).
1795 */
1796 interval = rai->mininterval;
1797 if (rai->mininterval != rai->maxinterval)
1798 interval += arc4random() % (rai->maxinterval-rai->mininterval);
1799
1800 /*
1801 * For the first few advertisements (up to
1802 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1803 * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1804 * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1805 * (RFC-2461 6.2.4)
1806 */
1807 if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1808 interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1809 interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1810
1811 tm->tv_sec = interval;
1812 tm->tv_nsec = 0;
1813
1814 syslog(LOG_DEBUG,
1815 "<%s> RA timer on %s is set to %ld:%ld",
1816 __func__, rai->ifname,
1817 (long int)tm->tv_sec, (long int)tm->tv_nsec);
1818
1819 return;
1820 }
1821