1 /* $FreeBSD$ */ 2 /* $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/param.h> 35 #include <sys/ioctl.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/time.h> 39 #include <sys/queue.h> 40 #include <sys/stat.h> 41 #include <sys/sysctl.h> 42 43 #include <net/if.h> 44 #include <net/if_types.h> 45 #include <net/if_media.h> 46 #include <net/if_dl.h> 47 #include <net/route.h> 48 #include <netinet/in.h> 49 #include <netinet/ip6.h> 50 #include <netinet6/ip6_var.h> 51 #include <netinet/icmp6.h> 52 53 #include <arpa/inet.h> 54 55 #include <net/if_var.h> 56 #include <netinet/in_var.h> 57 #include <netinet6/nd6.h> 58 59 #include <time.h> 60 #include <unistd.h> 61 #include <stdio.h> 62 #include <err.h> 63 #include <errno.h> 64 #include <inttypes.h> 65 #include <libutil.h> 66 #include <netdb.h> 67 #include <signal.h> 68 #include <string.h> 69 #include <stdlib.h> 70 #include <syslog.h> 71 #include <poll.h> 72 73 #include "pathnames.h" 74 #include "rtadvd.h" 75 #include "if.h" 76 #include "rrenum.h" 77 #include "advcap.h" 78 #include "timer_subr.h" 79 #include "timer.h" 80 #include "config.h" 81 #include "control.h" 82 #include "control_server.h" 83 84 #define RTADV_TYPE2BITMASK(type) (0x1 << type) 85 86 struct msghdr rcvmhdr; 87 static char *rcvcmsgbuf; 88 static size_t rcvcmsgbuflen; 89 static char *sndcmsgbuf = NULL; 90 static size_t sndcmsgbuflen; 91 struct msghdr sndmhdr; 92 struct iovec rcviov[2]; 93 struct iovec sndiov[2]; 94 struct sockaddr_in6 rcvfrom; 95 static const char *pidfilename = _PATH_RTADVDPID; 96 const char *conffile = _PATH_RTADVDCONF; 97 static struct pidfh *pfh; 98 int dflag = 0, sflag = 0; 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 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 int 170 main(int argc, char *argv[]) 171 { 172 struct pollfd set[PFD_MAX]; 173 struct timeval *timeout; 174 int i, ch; 175 int fflag = 0, logopt; 176 int error; 177 pid_t pid, otherpid; 178 179 /* get command line options and arguments */ 180 while ((ch = getopt(argc, argv, "c:C:dDfM:p:Rs")) != -1) { 181 switch (ch) { 182 case 'c': 183 conffile = optarg; 184 break; 185 case 'C': 186 ctrlsock.si_name = optarg; 187 break; 188 case 'd': 189 dflag++; 190 break; 191 case 'D': 192 dflag += 3; 193 break; 194 case 'f': 195 fflag = 1; 196 break; 197 case 'M': 198 mcastif = optarg; 199 break; 200 case 'R': 201 fprintf(stderr, "rtadvd: " 202 "the -R option is currently ignored.\n"); 203 /* accept_rr = 1; */ 204 /* run anyway... */ 205 break; 206 case 's': 207 sflag = 1; 208 break; 209 case 'p': 210 pidfilename = optarg; 211 break; 212 } 213 } 214 argc -= optind; 215 argv += optind; 216 if (argc == 0) { 217 fprintf(stderr, 218 "usage: rtadvd [-dDfRs] [-c conffile] " 219 "[-C ctrlsockname] [-M ifname] " 220 "[-p pidfile] interfaces...\n"); 221 exit(1); 222 } 223 224 logopt = LOG_NDELAY | LOG_PID; 225 if (fflag) 226 logopt |= LOG_PERROR; 227 openlog("rtadvd", logopt, LOG_DAEMON); 228 229 /* set log level */ 230 if (dflag > 2) 231 (void)setlogmask(LOG_UPTO(LOG_DEBUG)); 232 else if (dflag > 1) 233 (void)setlogmask(LOG_UPTO(LOG_INFO)); 234 else if (dflag > 0) 235 (void)setlogmask(LOG_UPTO(LOG_NOTICE)); 236 else 237 (void)setlogmask(LOG_UPTO(LOG_ERR)); 238 239 /* timer initialization */ 240 rtadvd_timer_init(); 241 242 #ifndef HAVE_ARC4RANDOM 243 /* random value initialization */ 244 #ifdef __FreeBSD__ 245 srandomdev(); 246 #else 247 srandom((unsigned long)time(NULL)); 248 #endif 249 #endif 250 pfh = pidfile_open(pidfilename, 0600, &otherpid); 251 if (pfh == NULL) { 252 if (errno == EEXIST) 253 errx(1, "%s already running, pid: %d", 254 getprogname(), otherpid); 255 syslog(LOG_ERR, 256 "failed to open the pid file %s, run anyway.", 257 pidfilename); 258 } 259 if (!fflag) 260 daemon(1, 0); 261 262 sock_open(&sock); 263 264 update_ifinfo(&ifilist, UPDATE_IFINFO_ALL); 265 for (i = 0; i < argc; i++) 266 update_persist_ifinfo(&ifilist, argv[i]); 267 268 csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH); 269 if (ctrlsock.si_fd == -1) { 270 syslog(LOG_ERR, "cannot open control socket: %s", 271 strerror(errno)); 272 exit(1); 273 } 274 275 /* record the current PID */ 276 pid = getpid(); 277 pidfile_write(pfh); 278 279 set[PFD_RAWSOCK].fd = sock.si_fd; 280 set[PFD_RAWSOCK].events = POLLIN; 281 if (sflag == 0) { 282 rtsock_open(&rtsock); 283 set[PFD_RTSOCK].fd = rtsock.si_fd; 284 set[PFD_RTSOCK].events = POLLIN; 285 } else 286 set[PFD_RTSOCK].fd = -1; 287 set[PFD_CSOCK].fd = ctrlsock.si_fd; 288 set[PFD_CSOCK].events = POLLIN; 289 signal(SIGTERM, set_do_shutdown); 290 signal(SIGINT, set_do_shutdown); 291 signal(SIGHUP, set_do_reload); 292 293 error = csock_listen(&ctrlsock); 294 if (error) { 295 syslog(LOG_ERR, "cannot listen control socket: %s", 296 strerror(errno)); 297 exit(1); 298 } 299 300 /* load configuration file */ 301 set_do_reload(0); 302 303 while (1) { 304 if (is_do_shutdown()) 305 rtadvd_shutdown(); 306 307 if (is_do_reload()) { 308 loadconfig_ifname(reload_ifname()); 309 if (reload_ifname() == NULL) 310 syslog(LOG_INFO, 311 "configuration file reloaded."); 312 else 313 syslog(LOG_INFO, 314 "configuration file for %s reloaded.", 315 reload_ifname()); 316 reset_do_reload(); 317 } 318 319 /* timeout handler update for active interfaces */ 320 rtadvd_update_timeout_handler(); 321 322 /* timer expiration check and reset the timer */ 323 timeout = rtadvd_check_timer(); 324 325 if (timeout != NULL) { 326 syslog(LOG_DEBUG, 327 "<%s> set timer to %ld:%ld. waiting for " 328 "inputs or timeout", __func__, 329 (long int)timeout->tv_sec, 330 (long int)timeout->tv_usec); 331 } else { 332 syslog(LOG_DEBUG, 333 "<%s> there's no timer. waiting for inputs", 334 __func__); 335 } 336 if ((i = poll(set, sizeof(set)/sizeof(set[0]), 337 timeout ? (timeout->tv_sec * 1000 + 338 timeout->tv_usec / 1000) : INFTIM)) < 0) { 339 340 /* EINTR would occur if a signal was delivered */ 341 if (errno != EINTR) 342 syslog(LOG_ERR, "poll() failed: %s", 343 strerror(errno)); 344 continue; 345 } 346 if (i == 0) /* timeout */ 347 continue; 348 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN) 349 rtmsg_input(&rtsock); 350 351 if (set[PFD_RAWSOCK].revents & POLLIN) 352 rtadvd_input(&sock); 353 354 if (set[PFD_CSOCK].revents & POLLIN) { 355 int fd; 356 357 fd = csock_accept(&ctrlsock); 358 if (fd == -1) 359 syslog(LOG_ERR, 360 "cannot accept() control socket: %s", 361 strerror(errno)); 362 else { 363 cm_handler_server(fd); 364 close(fd); 365 } 366 } 367 } 368 exit(0); /* NOTREACHED */ 369 } 370 371 static void 372 rtadvd_shutdown(void) 373 { 374 struct ifinfo *ifi; 375 struct rainfo *rai; 376 struct rdnss *rdn; 377 struct dnssl *dns; 378 379 if (wait_shutdown) { 380 syslog(LOG_INFO, 381 "waiting expiration of the all RA timers."); 382 383 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 384 /* 385 * Ignore !IFF_UP interfaces in waiting for shutdown. 386 */ 387 if (!(ifi->ifi_flags & IFF_UP) && 388 ifi->ifi_ra_timer != NULL) { 389 ifi->ifi_state = IFI_STATE_UNCONFIGURED; 390 rtadvd_remove_timer(ifi->ifi_ra_timer); 391 ifi->ifi_ra_timer = NULL; 392 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. " 393 "Timer removed and marked as UNCONFIGURED.", 394 __func__, ifi->ifi_ifname, 395 ifi->ifi_ifindex); 396 } 397 } 398 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 399 if (ifi->ifi_ra_timer != NULL) 400 break; 401 } 402 if (ifi == NULL) { 403 syslog(LOG_NOTICE, "gracefully terminated."); 404 exit(0); 405 } 406 407 sleep(1); 408 return; 409 } 410 411 syslog(LOG_DEBUG, "<%s> cease to be an advertising router", 412 __func__); 413 414 wait_shutdown = 1; 415 416 TAILQ_FOREACH(rai, &railist, rai_next) { 417 rai->rai_lifetime = 0; 418 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next) 419 rdn->rd_ltime = 0; 420 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next) 421 dns->dn_ltime = 0; 422 } 423 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 424 if (!ifi->ifi_persist) 425 continue; 426 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED) 427 continue; 428 if (ifi->ifi_ra_timer == NULL) 429 continue; 430 if (ifi->ifi_ra_lastsent.tv_sec == 0 && 431 ifi->ifi_ra_lastsent.tv_usec == 0 && 432 ifi->ifi_ra_timer != NULL) { 433 /* 434 * When RA configured but never sent, 435 * ignore the IF immediately. 436 */ 437 rtadvd_remove_timer(ifi->ifi_ra_timer); 438 ifi->ifi_ra_timer = NULL; 439 ifi->ifi_state = IFI_STATE_UNCONFIGURED; 440 continue; 441 } 442 443 ifi->ifi_state = IFI_STATE_TRANSITIVE; 444 445 /* Mark as the shut-down state. */ 446 ifi->ifi_rainfo_trans = ifi->ifi_rainfo; 447 ifi->ifi_rainfo = NULL; 448 449 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS; 450 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS; 451 452 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm); 453 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm, 454 ifi->ifi_ra_timer); 455 } 456 syslog(LOG_NOTICE, "final RA transmission started."); 457 458 pidfile_remove(pfh); 459 csock_close(&ctrlsock); 460 } 461 462 static void 463 rtmsg_input(struct sockinfo *s) 464 { 465 int n, type, ifindex = 0, plen; 466 size_t len; 467 char msg[2048], *next, *lim; 468 char ifname[IFNAMSIZ]; 469 struct if_announcemsghdr *ifan; 470 struct rt_msghdr *rtm; 471 struct prefix *pfx; 472 struct rainfo *rai; 473 struct in6_addr *addr; 474 struct ifinfo *ifi; 475 char addrbuf[INET6_ADDRSTRLEN]; 476 int prefixchange = 0; 477 478 if (s == NULL) { 479 syslog(LOG_ERR, "<%s> internal error", __func__); 480 exit(1); 481 } 482 n = read(s->si_fd, msg, sizeof(msg)); 483 rtm = (struct rt_msghdr *)msg; 484 syslog(LOG_DEBUG, "<%s> received a routing message " 485 "(type = %d, len = %d)", __func__, rtm->rtm_type, n); 486 487 if (n > rtm->rtm_msglen) { 488 /* 489 * This usually won't happen for messages received on 490 * a routing socket. 491 */ 492 syslog(LOG_DEBUG, 493 "<%s> received data length is larger than " 494 "1st routing message len. multiple messages? " 495 "read %d bytes, but 1st msg len = %d", 496 __func__, n, rtm->rtm_msglen); 497 #if 0 498 /* adjust length */ 499 n = rtm->rtm_msglen; 500 #endif 501 } 502 503 lim = msg + n; 504 for (next = msg; next < lim; next += len) { 505 int oldifflags; 506 507 next = get_next_msg(next, lim, 0, &len, 508 RTADV_TYPE2BITMASK(RTM_ADD) | 509 RTADV_TYPE2BITMASK(RTM_DELETE) | 510 RTADV_TYPE2BITMASK(RTM_NEWADDR) | 511 RTADV_TYPE2BITMASK(RTM_DELADDR) | 512 RTADV_TYPE2BITMASK(RTM_IFINFO) | 513 RTADV_TYPE2BITMASK(RTM_IFANNOUNCE)); 514 if (len == 0) 515 break; 516 type = ((struct rt_msghdr *)next)->rtm_type; 517 switch (type) { 518 case RTM_ADD: 519 case RTM_DELETE: 520 ifindex = get_rtm_ifindex(next); 521 break; 522 case RTM_NEWADDR: 523 case RTM_DELADDR: 524 ifindex = (int)((struct ifa_msghdr *)next)->ifam_index; 525 break; 526 case RTM_IFINFO: 527 ifindex = (int)((struct if_msghdr *)next)->ifm_index; 528 break; 529 case RTM_IFANNOUNCE: 530 ifan = (struct if_announcemsghdr *)next; 531 switch (ifan->ifan_what) { 532 case IFAN_ARRIVAL: 533 case IFAN_DEPARTURE: 534 break; 535 default: 536 syslog(LOG_DEBUG, 537 "<%s:%d> unknown ifan msg (ifan_what=%d)", 538 __func__, __LINE__, ifan->ifan_what); 539 continue; 540 } 541 542 syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)", 543 __func__, ifan->ifan_index, ifan->ifan_what); 544 switch (ifan->ifan_what) { 545 case IFAN_ARRIVAL: 546 syslog(LOG_NOTICE, 547 "interface added (idx=%d)", 548 ifan->ifan_index); 549 update_ifinfo(&ifilist, ifan->ifan_index); 550 loadconfig_index(ifan->ifan_index); 551 break; 552 case IFAN_DEPARTURE: 553 syslog(LOG_NOTICE, 554 "interface removed (idx=%d)", 555 ifan->ifan_index); 556 rm_ifinfo_index(ifan->ifan_index); 557 558 /* Clear ifi_ifindex */ 559 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 560 if (ifi->ifi_ifindex 561 == ifan->ifan_index) { 562 ifi->ifi_ifindex = 0; 563 break; 564 } 565 } 566 update_ifinfo(&ifilist, ifan->ifan_index); 567 break; 568 } 569 continue; 570 default: 571 /* should not reach here */ 572 syslog(LOG_DEBUG, 573 "<%s:%d> unknown rtmsg %d on %s", 574 __func__, __LINE__, type, 575 if_indextoname(ifindex, ifname)); 576 continue; 577 } 578 ifi = if_indextoifinfo(ifindex); 579 if (ifi == NULL) { 580 syslog(LOG_DEBUG, 581 "<%s> ifinfo not found for idx=%d. Why?", 582 __func__, ifindex); 583 continue; 584 } 585 rai = ifi->ifi_rainfo; 586 if (rai == NULL) { 587 syslog(LOG_DEBUG, 588 "<%s> route changed on " 589 "non advertising interface(%s)", 590 __func__, ifi->ifi_ifname); 591 continue; 592 } 593 594 oldifflags = ifi->ifi_flags; 595 /* init ifflags because it may have changed */ 596 update_ifinfo(&ifilist, ifindex); 597 598 switch (type) { 599 case RTM_ADD: 600 if (sflag) 601 break; /* we aren't interested in prefixes */ 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, "<%s> new interface route's" 609 "plen %d is invalid for a prefix", 610 __func__, plen); 611 break; 612 } 613 pfx = find_prefix(rai, addr, plen); 614 if (pfx) { 615 if (pfx->pfx_timer) { 616 /* 617 * If the prefix has been invalidated, 618 * make it available again. 619 */ 620 update_prefix(pfx); 621 prefixchange = 1; 622 } else 623 syslog(LOG_DEBUG, 624 "<%s> new prefix(%s/%d) " 625 "added on %s, " 626 "but it was already in list", 627 __func__, 628 inet_ntop(AF_INET6, addr, 629 (char *)addrbuf, 630 sizeof(addrbuf)), 631 plen, ifi->ifi_ifname); 632 break; 633 } 634 make_prefix(rai, ifindex, addr, plen); 635 prefixchange = 1; 636 break; 637 case RTM_DELETE: 638 if (sflag) 639 break; 640 641 addr = get_addr(msg); 642 plen = get_prefixlen(msg); 643 /* sanity check for plen */ 644 /* as RFC2373, prefixlen is at least 4 */ 645 if (plen < 4 || plen > 127) { 646 syslog(LOG_INFO, 647 "<%s> deleted interface route's " 648 "plen %d is invalid for a prefix", 649 __func__, plen); 650 break; 651 } 652 pfx = find_prefix(rai, addr, plen); 653 if (pfx == NULL) { 654 syslog(LOG_DEBUG, 655 "<%s> prefix(%s/%d) was deleted on %s, " 656 "but it was not in list", 657 __func__, inet_ntop(AF_INET6, addr, 658 (char *)addrbuf, sizeof(addrbuf)), 659 plen, ifi->ifi_ifname); 660 break; 661 } 662 invalidate_prefix(pfx); 663 prefixchange = 1; 664 break; 665 case RTM_NEWADDR: 666 case RTM_DELADDR: 667 case RTM_IFINFO: 668 break; 669 default: 670 /* should not reach here */ 671 syslog(LOG_DEBUG, 672 "<%s:%d> unknown rtmsg %d on %s", 673 __func__, __LINE__, type, 674 if_indextoname(ifindex, ifname)); 675 return; 676 } 677 678 /* check if an interface flag is changed */ 679 if ((oldifflags & IFF_UP) && /* UP to DOWN */ 680 !(ifi->ifi_flags & IFF_UP)) { 681 syslog(LOG_NOTICE, 682 "<interface %s becomes down. stop timer.", 683 ifi->ifi_ifname); 684 rtadvd_remove_timer(ifi->ifi_ra_timer); 685 ifi->ifi_ra_timer = NULL; 686 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */ 687 (ifi->ifi_flags & IFF_UP)) { 688 syslog(LOG_NOTICE, 689 "interface %s becomes up. restart timer.", 690 ifi->ifi_ifname); 691 692 ifi->ifi_state = IFI_STATE_TRANSITIVE; 693 ifi->ifi_burstcount = 694 MAX_INITIAL_RTR_ADVERTISEMENTS; 695 ifi->ifi_burstinterval = 696 MAX_INITIAL_RTR_ADVERT_INTERVAL; 697 698 ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout, 699 ra_timer_update, ifi, ifi); 700 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm); 701 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm, 702 ifi->ifi_ra_timer); 703 } else if (prefixchange && 704 (ifi->ifi_flags & IFF_UP)) { 705 /* 706 * An advertised prefix has been added or invalidated. 707 * Will notice the change in a short delay. 708 */ 709 set_short_delay(ifi); 710 } 711 } 712 713 return; 714 } 715 716 void 717 rtadvd_input(struct sockinfo *s) 718 { 719 ssize_t i; 720 int *hlimp = NULL; 721 #ifdef OLDRAWSOCKET 722 struct ip6_hdr *ip; 723 #endif 724 struct icmp6_hdr *icp; 725 int ifindex = 0; 726 struct cmsghdr *cm; 727 struct in6_pktinfo *pi = NULL; 728 char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 729 struct in6_addr dst = in6addr_any; 730 struct ifinfo *ifi; 731 732 syslog(LOG_DEBUG, "<%s> enter", __func__); 733 734 if (s == NULL) { 735 syslog(LOG_ERR, "<%s> internal error", __func__); 736 exit(1); 737 } 738 /* 739 * Get message. We reset msg_controllen since the field could 740 * be modified if we had received a message before setting 741 * receive options. 742 */ 743 rcvmhdr.msg_controllen = rcvcmsgbuflen; 744 if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0) 745 return; 746 747 /* extract optional information via Advanced API */ 748 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); 749 cm; 750 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) { 751 if (cm->cmsg_level == IPPROTO_IPV6 && 752 cm->cmsg_type == IPV6_PKTINFO && 753 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { 754 pi = (struct in6_pktinfo *)(CMSG_DATA(cm)); 755 ifindex = pi->ipi6_ifindex; 756 dst = pi->ipi6_addr; 757 } 758 if (cm->cmsg_level == IPPROTO_IPV6 && 759 cm->cmsg_type == IPV6_HOPLIMIT && 760 cm->cmsg_len == CMSG_LEN(sizeof(int))) 761 hlimp = (int *)CMSG_DATA(cm); 762 } 763 if (ifindex == 0) { 764 syslog(LOG_ERR, "failed to get receiving interface"); 765 return; 766 } 767 if (hlimp == NULL) { 768 syslog(LOG_ERR, "failed to get receiving hop limit"); 769 return; 770 } 771 772 /* 773 * If we happen to receive data on an interface which is now gone 774 * or down, just discard the data. 775 */ 776 ifi = if_indextoifinfo(pi->ipi6_ifindex); 777 if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) { 778 syslog(LOG_INFO, 779 "<%s> received data on a disabled interface (%s)", 780 __func__, 781 (ifi == NULL) ? "[gone]" : ifi->ifi_ifname); 782 return; 783 } 784 785 #ifdef OLDRAWSOCKET 786 if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) { 787 syslog(LOG_ERR, 788 "packet size(%d) is too short", i); 789 return; 790 } 791 792 ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base; 793 icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */ 794 #else 795 if ((size_t)i < sizeof(struct icmp6_hdr)) { 796 syslog(LOG_ERR, "packet size(%zd) is too short", i); 797 return; 798 } 799 800 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base; 801 #endif 802 803 switch (icp->icmp6_type) { 804 case ND_ROUTER_SOLICIT: 805 /* 806 * Message verification - RFC 4861 6.1.1 807 * XXX: these checks must be done in the kernel as well, 808 * but we can't completely rely on them. 809 */ 810 if (*hlimp != 255) { 811 syslog(LOG_NOTICE, 812 "RS with invalid hop limit(%d) " 813 "received from %s on %s", 814 *hlimp, 815 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 816 sizeof(ntopbuf)), 817 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 818 return; 819 } 820 if (icp->icmp6_code) { 821 syslog(LOG_NOTICE, 822 "RS with invalid ICMP6 code(%d) " 823 "received from %s on %s", 824 icp->icmp6_code, 825 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 826 sizeof(ntopbuf)), 827 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 828 return; 829 } 830 if ((size_t)i < sizeof(struct nd_router_solicit)) { 831 syslog(LOG_NOTICE, 832 "RS from %s on %s does not have enough " 833 "length (len = %zd)", 834 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 835 sizeof(ntopbuf)), 836 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i); 837 return; 838 } 839 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom); 840 break; 841 case ND_ROUTER_ADVERT: 842 /* 843 * Message verification - RFC 4861 6.1.2 844 * XXX: there's the same dilemma as above... 845 */ 846 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) { 847 syslog(LOG_NOTICE, 848 "RA with non-linklocal source address " 849 "received from %s on %s", 850 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, 851 ntopbuf, sizeof(ntopbuf)), 852 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 853 return; 854 } 855 if (*hlimp != 255) { 856 syslog(LOG_NOTICE, 857 "RA with invalid hop limit(%d) " 858 "received from %s on %s", 859 *hlimp, 860 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 861 sizeof(ntopbuf)), 862 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 863 return; 864 } 865 if (icp->icmp6_code) { 866 syslog(LOG_NOTICE, 867 "RA with invalid ICMP6 code(%d) " 868 "received from %s on %s", 869 icp->icmp6_code, 870 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 871 sizeof(ntopbuf)), 872 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 873 return; 874 } 875 if ((size_t)i < sizeof(struct nd_router_advert)) { 876 syslog(LOG_NOTICE, 877 "RA from %s on %s does not have enough " 878 "length (len = %zd)", 879 inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf, 880 sizeof(ntopbuf)), 881 if_indextoname(pi->ipi6_ifindex, ifnamebuf), i); 882 return; 883 } 884 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom); 885 break; 886 case ICMP6_ROUTER_RENUMBERING: 887 if (mcastif == NULL) { 888 syslog(LOG_ERR, "received a router renumbering " 889 "message, but not allowed to be accepted"); 890 break; 891 } 892 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom, 893 &dst); 894 break; 895 default: 896 /* 897 * Note that this case is POSSIBLE, especially just 898 * after invocation of the daemon. This is because we 899 * could receive message after opening the socket and 900 * before setting ICMP6 type filter(see sock_open()). 901 */ 902 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type); 903 return; 904 } 905 906 return; 907 } 908 909 static void 910 rs_input(int len, struct nd_router_solicit *rs, 911 struct in6_pktinfo *pi, struct sockaddr_in6 *from) 912 { 913 char ntopbuf[INET6_ADDRSTRLEN]; 914 char ifnamebuf[IFNAMSIZ]; 915 union nd_opt ndopts; 916 struct rainfo *rai; 917 struct ifinfo *ifi; 918 struct soliciter *sol; 919 920 syslog(LOG_DEBUG, 921 "<%s> RS received from %s on %s", 922 __func__, 923 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), 924 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 925 926 /* ND option check */ 927 memset(&ndopts, 0, sizeof(ndopts)); 928 TAILQ_INIT(&ndopts.opt_list); 929 if (nd6_options((struct nd_opt_hdr *)(rs + 1), 930 len - sizeof(struct nd_router_solicit), 931 &ndopts, NDOPT_FLAG_SRCLINKADDR)) { 932 syslog(LOG_INFO, 933 "<%s> ND option check failed for an RS from %s on %s", 934 __func__, 935 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 936 sizeof(ntopbuf)), 937 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 938 return; 939 } 940 941 /* 942 * If the IP source address is the unspecified address, there 943 * must be no source link-layer address option in the message. 944 * (RFC 4861 6.1.1) 945 */ 946 if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) && 947 ndopts.opt_src_lladdr) { 948 syslog(LOG_INFO, 949 "<%s> RS from unspecified src on %s has a link-layer" 950 " address option", 951 __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 952 goto done; 953 } 954 955 ifi = if_indextoifinfo(pi->ipi6_ifindex); 956 if (ifi == NULL) { 957 syslog(LOG_INFO, 958 "<%s> if (idx=%d) not found. Why?", 959 __func__, pi->ipi6_ifindex); 960 goto done; 961 } 962 rai = ifi->ifi_rainfo; 963 if (rai == NULL) { 964 syslog(LOG_INFO, 965 "<%s> RS received on non advertising interface(%s)", 966 __func__, 967 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 968 goto done; 969 } 970 971 rai->rai_ifinfo->ifi_rsinput++; 972 973 /* 974 * Decide whether to send RA according to the rate-limit 975 * consideration. 976 */ 977 978 /* record sockaddr waiting for RA, if possible */ 979 sol = (struct soliciter *)malloc(sizeof(*sol)); 980 if (sol) { 981 sol->sol_addr = *from; 982 /* XXX RFC 2553 need clarification on flowinfo */ 983 sol->sol_addr.sin6_flowinfo = 0; 984 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next); 985 } 986 987 /* 988 * If there is already a waiting RS packet, don't 989 * update the timer. 990 */ 991 if (ifi->ifi_rs_waitcount++) 992 goto done; 993 994 set_short_delay(ifi); 995 996 done: 997 free_ndopts(&ndopts); 998 return; 999 } 1000 1001 static void 1002 set_short_delay(struct ifinfo *ifi) 1003 { 1004 long delay; /* must not be greater than 1000000 */ 1005 struct timeval interval, now, min_delay, tm_tmp, *rest; 1006 1007 /* 1008 * Compute a random delay. If the computed value 1009 * corresponds to a time later than the time the next 1010 * multicast RA is scheduled to be sent, ignore the random 1011 * delay and send the advertisement at the 1012 * already-scheduled time. RFC 4861 6.2.6 1013 */ 1014 #ifdef HAVE_ARC4RANDOM 1015 delay = arc4random_uniform(MAX_RA_DELAY_TIME); 1016 #else 1017 delay = random() % MAX_RA_DELAY_TIME; 1018 #endif 1019 interval.tv_sec = 0; 1020 interval.tv_usec = delay; 1021 rest = rtadvd_timer_rest(ifi->ifi_ra_timer); 1022 if (TIMEVAL_LT(rest, &interval)) { 1023 syslog(LOG_DEBUG, "<%s> random delay is larger than " 1024 "the rest of the current timer", __func__); 1025 interval = *rest; 1026 } 1027 1028 /* 1029 * If we sent a multicast Router Advertisement within 1030 * the last MIN_DELAY_BETWEEN_RAS seconds, schedule 1031 * the advertisement to be sent at a time corresponding to 1032 * MIN_DELAY_BETWEEN_RAS plus the random value after the 1033 * previous advertisement was sent. 1034 */ 1035 gettimeofday(&now, NULL); 1036 TIMEVAL_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp); 1037 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS; 1038 min_delay.tv_usec = 0; 1039 if (TIMEVAL_LT(&tm_tmp, &min_delay)) { 1040 TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay); 1041 TIMEVAL_ADD(&min_delay, &interval, &interval); 1042 } 1043 rtadvd_set_timer(&interval, ifi->ifi_ra_timer); 1044 } 1045 1046 static int 1047 check_accept_rtadv(int idx) 1048 { 1049 struct ifinfo *ifi; 1050 1051 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 1052 if (ifi->ifi_ifindex == idx) 1053 break; 1054 } 1055 if (ifi == NULL) { 1056 syslog(LOG_DEBUG, 1057 "<%s> if (idx=%d) not found. Why?", 1058 __func__, idx); 1059 return (0); 1060 } 1061 #if (__FreeBSD_version < 900000) 1062 /* 1063 * RA_RECV: !ip6.forwarding && ip6.accept_rtadv 1064 * RA_SEND: ip6.forwarding 1065 */ 1066 return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) && 1067 (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1)); 1068 #else 1069 /* 1070 * RA_RECV: ND6_IFF_ACCEPT_RTADV 1071 * RA_SEND: ip6.forwarding 1072 */ 1073 if (update_ifinfo_nd_flags(ifi) != 0) { 1074 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx); 1075 return (0); 1076 } 1077 1078 return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV); 1079 #endif 1080 } 1081 1082 static void 1083 ra_input(int len, struct nd_router_advert *nra, 1084 struct in6_pktinfo *pi, struct sockaddr_in6 *from) 1085 { 1086 struct rainfo *rai; 1087 struct ifinfo *ifi; 1088 char ntopbuf[INET6_ADDRSTRLEN]; 1089 char ifnamebuf[IFNAMSIZ]; 1090 union nd_opt ndopts; 1091 const char *on_off[] = {"OFF", "ON"}; 1092 uint32_t reachabletime, retranstimer, mtu; 1093 int inconsistent = 0; 1094 int error; 1095 1096 syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__, 1097 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)), 1098 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 1099 1100 /* ND option check */ 1101 memset(&ndopts, 0, sizeof(ndopts)); 1102 TAILQ_INIT(&ndopts.opt_list); 1103 error = nd6_options((struct nd_opt_hdr *)(nra + 1), 1104 len - sizeof(struct nd_router_advert), &ndopts, 1105 NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU | 1106 NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL); 1107 if (error) { 1108 syslog(LOG_INFO, 1109 "<%s> ND option check failed for an RA from %s on %s", 1110 __func__, 1111 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1112 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, 1113 ifnamebuf)); 1114 return; 1115 } 1116 1117 /* 1118 * RA consistency check according to RFC 4861 6.2.7 1119 */ 1120 ifi = if_indextoifinfo(pi->ipi6_ifindex); 1121 if (ifi->ifi_rainfo == NULL) { 1122 syslog(LOG_INFO, 1123 "<%s> received RA from %s on non-advertising" 1124 " interface(%s)", 1125 __func__, 1126 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1127 sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex, 1128 ifnamebuf)); 1129 goto done; 1130 } 1131 rai = ifi->ifi_rainfo; 1132 ifi->ifi_rainput++; 1133 syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__, 1134 ifi->ifi_rainput); 1135 1136 /* Cur Hop Limit value */ 1137 if (nra->nd_ra_curhoplimit && rai->rai_hoplimit && 1138 nra->nd_ra_curhoplimit != rai->rai_hoplimit) { 1139 syslog(LOG_NOTICE, 1140 "CurHopLimit inconsistent on %s:" 1141 " %d from %s, %d from us", 1142 ifi->ifi_ifname, nra->nd_ra_curhoplimit, 1143 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1144 sizeof(ntopbuf)), rai->rai_hoplimit); 1145 inconsistent++; 1146 } 1147 /* M flag */ 1148 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) != 1149 rai->rai_managedflg) { 1150 syslog(LOG_NOTICE, 1151 "M flag inconsistent on %s:" 1152 " %s from %s, %s from us", 1153 ifi->ifi_ifname, on_off[!rai->rai_managedflg], 1154 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1155 sizeof(ntopbuf)), on_off[rai->rai_managedflg]); 1156 inconsistent++; 1157 } 1158 /* O flag */ 1159 if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) != 1160 rai->rai_otherflg) { 1161 syslog(LOG_NOTICE, 1162 "O flag inconsistent on %s:" 1163 " %s from %s, %s from us", 1164 ifi->ifi_ifname, on_off[!rai->rai_otherflg], 1165 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1166 sizeof(ntopbuf)), on_off[rai->rai_otherflg]); 1167 inconsistent++; 1168 } 1169 /* Reachable Time */ 1170 reachabletime = ntohl(nra->nd_ra_reachable); 1171 if (reachabletime && rai->rai_reachabletime && 1172 reachabletime != rai->rai_reachabletime) { 1173 syslog(LOG_NOTICE, 1174 "ReachableTime inconsistent on %s:" 1175 " %d from %s, %d from us", 1176 ifi->ifi_ifname, reachabletime, 1177 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1178 sizeof(ntopbuf)), rai->rai_reachabletime); 1179 inconsistent++; 1180 } 1181 /* Retrans Timer */ 1182 retranstimer = ntohl(nra->nd_ra_retransmit); 1183 if (retranstimer && rai->rai_retranstimer && 1184 retranstimer != rai->rai_retranstimer) { 1185 syslog(LOG_NOTICE, 1186 "RetranceTimer inconsistent on %s:" 1187 " %d from %s, %d from us", 1188 ifi->ifi_ifname, retranstimer, 1189 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1190 sizeof(ntopbuf)), rai->rai_retranstimer); 1191 inconsistent++; 1192 } 1193 /* Values in the MTU options */ 1194 if (ndopts.opt_mtu) { 1195 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu); 1196 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) { 1197 syslog(LOG_NOTICE, 1198 "MTU option value inconsistent on %s:" 1199 " %d from %s, %d from us", 1200 ifi->ifi_ifname, mtu, 1201 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1202 sizeof(ntopbuf)), rai->rai_linkmtu); 1203 inconsistent++; 1204 } 1205 } 1206 /* Preferred and Valid Lifetimes for prefixes */ 1207 { 1208 struct nd_optlist *nol; 1209 1210 if (ndopts.opt_pi) 1211 if (prefix_check(ndopts.opt_pi, rai, from)) 1212 inconsistent++; 1213 1214 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next) 1215 if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt, 1216 rai, from)) 1217 inconsistent++; 1218 } 1219 1220 if (inconsistent) 1221 ifi->ifi_rainconsistent++; 1222 1223 done: 1224 free_ndopts(&ndopts); 1225 return; 1226 } 1227 1228 /* return a non-zero value if the received prefix is inconsitent with ours */ 1229 static int 1230 prefix_check(struct nd_opt_prefix_info *pinfo, 1231 struct rainfo *rai, struct sockaddr_in6 *from) 1232 { 1233 struct ifinfo *ifi; 1234 uint32_t preferred_time, valid_time; 1235 struct prefix *pfx; 1236 int inconsistent = 0; 1237 char ntopbuf[INET6_ADDRSTRLEN]; 1238 char prefixbuf[INET6_ADDRSTRLEN]; 1239 struct timeval now; 1240 1241 #if 0 /* impossible */ 1242 if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION) 1243 return (0); 1244 #endif 1245 ifi = rai->rai_ifinfo; 1246 /* 1247 * log if the adveritsed prefix has link-local scope(sanity check?) 1248 */ 1249 if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) 1250 syslog(LOG_INFO, 1251 "<%s> link-local prefix %s/%d is advertised " 1252 "from %s on %s", 1253 __func__, 1254 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1255 sizeof(prefixbuf)), 1256 pinfo->nd_opt_pi_prefix_len, 1257 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1258 sizeof(ntopbuf)), ifi->ifi_ifname); 1259 1260 if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix, 1261 pinfo->nd_opt_pi_prefix_len)) == NULL) { 1262 syslog(LOG_INFO, 1263 "<%s> prefix %s/%d from %s on %s is not in our list", 1264 __func__, 1265 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1266 sizeof(prefixbuf)), 1267 pinfo->nd_opt_pi_prefix_len, 1268 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1269 sizeof(ntopbuf)), ifi->ifi_ifname); 1270 return (0); 1271 } 1272 1273 preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time); 1274 if (pfx->pfx_pltimeexpire) { 1275 /* 1276 * The lifetime is decremented in real time, so we should 1277 * compare the expiration time. 1278 * (RFC 2461 Section 6.2.7.) 1279 * XXX: can we really expect that all routers on the link 1280 * have synchronized clocks? 1281 */ 1282 gettimeofday(&now, NULL); 1283 preferred_time += now.tv_sec; 1284 1285 if (!pfx->pfx_timer && rai->rai_clockskew && 1286 abs(preferred_time - pfx->pfx_pltimeexpire) > rai->rai_clockskew) { 1287 syslog(LOG_INFO, 1288 "<%s> preferred lifetime for %s/%d" 1289 " (decr. in real time) inconsistent on %s:" 1290 " %" PRIu32 " from %s, %" PRIu32 " from us", 1291 __func__, 1292 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1293 sizeof(prefixbuf)), 1294 pinfo->nd_opt_pi_prefix_len, 1295 ifi->ifi_ifname, preferred_time, 1296 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1297 sizeof(ntopbuf)), pfx->pfx_pltimeexpire); 1298 inconsistent++; 1299 } 1300 } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime) 1301 syslog(LOG_INFO, 1302 "<%s> preferred lifetime for %s/%d" 1303 " inconsistent on %s:" 1304 " %d from %s, %d from us", 1305 __func__, 1306 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1307 sizeof(prefixbuf)), 1308 pinfo->nd_opt_pi_prefix_len, 1309 ifi->ifi_ifname, preferred_time, 1310 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1311 sizeof(ntopbuf)), pfx->pfx_preflifetime); 1312 1313 valid_time = ntohl(pinfo->nd_opt_pi_valid_time); 1314 if (pfx->pfx_vltimeexpire) { 1315 gettimeofday(&now, NULL); 1316 valid_time += now.tv_sec; 1317 1318 if (!pfx->pfx_timer && rai->rai_clockskew && 1319 abs(valid_time - pfx->pfx_vltimeexpire) > rai->rai_clockskew) { 1320 syslog(LOG_INFO, 1321 "<%s> valid lifetime for %s/%d" 1322 " (decr. in real time) inconsistent on %s:" 1323 " %d from %s, %" PRIu32 " from us", 1324 __func__, 1325 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1326 sizeof(prefixbuf)), 1327 pinfo->nd_opt_pi_prefix_len, 1328 ifi->ifi_ifname, preferred_time, 1329 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1330 sizeof(ntopbuf)), pfx->pfx_vltimeexpire); 1331 inconsistent++; 1332 } 1333 } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) { 1334 syslog(LOG_INFO, 1335 "<%s> valid lifetime for %s/%d" 1336 " inconsistent on %s:" 1337 " %d from %s, %d from us", 1338 __func__, 1339 inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf, 1340 sizeof(prefixbuf)), 1341 pinfo->nd_opt_pi_prefix_len, 1342 ifi->ifi_ifname, valid_time, 1343 inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, 1344 sizeof(ntopbuf)), pfx->pfx_validlifetime); 1345 inconsistent++; 1346 } 1347 1348 return (inconsistent); 1349 } 1350 1351 struct prefix * 1352 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen) 1353 { 1354 struct prefix *pfx; 1355 int bytelen, bitlen; 1356 char bitmask; 1357 1358 TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) { 1359 if (plen != pfx->pfx_prefixlen) 1360 continue; 1361 1362 bytelen = plen / 8; 1363 bitlen = plen % 8; 1364 bitmask = 0xff << (8 - bitlen); 1365 1366 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen)) 1367 continue; 1368 1369 if (bitlen == 0 || 1370 ((prefix->s6_addr[bytelen] & bitmask) == 1371 (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) { 1372 return (pfx); 1373 } 1374 } 1375 1376 return (NULL); 1377 } 1378 1379 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */ 1380 int 1381 prefix_match(struct in6_addr *p0, int plen0, 1382 struct in6_addr *p1, int plen1) 1383 { 1384 int bytelen, bitlen; 1385 char bitmask; 1386 1387 if (plen0 < plen1) 1388 return (0); 1389 1390 bytelen = plen1 / 8; 1391 bitlen = plen1 % 8; 1392 bitmask = 0xff << (8 - bitlen); 1393 1394 if (memcmp((void *)p0, (void *)p1, bytelen)) 1395 return (0); 1396 1397 if (bitlen == 0 || 1398 ((p0->s6_addr[bytelen] & bitmask) == 1399 (p1->s6_addr[bytelen] & bitmask))) { 1400 return (1); 1401 } 1402 1403 return (0); 1404 } 1405 1406 static int 1407 nd6_options(struct nd_opt_hdr *hdr, int limit, 1408 union nd_opt *ndopts, uint32_t optflags) 1409 { 1410 int optlen = 0; 1411 1412 for (; limit > 0; limit -= optlen) { 1413 if ((size_t)limit < sizeof(struct nd_opt_hdr)) { 1414 syslog(LOG_INFO, "<%s> short option header", __func__); 1415 goto bad; 1416 } 1417 1418 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen); 1419 if (hdr->nd_opt_len == 0) { 1420 syslog(LOG_INFO, 1421 "<%s> bad ND option length(0) (type = %d)", 1422 __func__, hdr->nd_opt_type); 1423 goto bad; 1424 } 1425 optlen = hdr->nd_opt_len << 3; 1426 if (optlen > limit) { 1427 syslog(LOG_INFO, "<%s> short option", __func__); 1428 goto bad; 1429 } 1430 1431 if (hdr->nd_opt_type > ND_OPT_MTU && 1432 hdr->nd_opt_type != ND_OPT_RDNSS && 1433 hdr->nd_opt_type != ND_OPT_DNSSL) { 1434 syslog(LOG_INFO, "<%s> unknown ND option(type %d)", 1435 __func__, hdr->nd_opt_type); 1436 continue; 1437 } 1438 1439 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) { 1440 syslog(LOG_INFO, "<%s> unexpected ND option(type %d)", 1441 __func__, hdr->nd_opt_type); 1442 continue; 1443 } 1444 1445 /* 1446 * Option length check. Do it here for all fixed-length 1447 * options. 1448 */ 1449 switch (hdr->nd_opt_type) { 1450 case ND_OPT_MTU: 1451 if (optlen == sizeof(struct nd_opt_mtu)) 1452 break; 1453 goto skip; 1454 case ND_OPT_RDNSS: 1455 if (optlen >= 24 && 1456 (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0) 1457 break; 1458 goto skip; 1459 case ND_OPT_DNSSL: 1460 if (optlen >= 16 && 1461 (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0) 1462 break; 1463 goto skip; 1464 case ND_OPT_PREFIX_INFORMATION: 1465 if (optlen == sizeof(struct nd_opt_prefix_info)) 1466 break; 1467 skip: 1468 syslog(LOG_INFO, "<%s> invalid option length", 1469 __func__); 1470 continue; 1471 } 1472 1473 switch (hdr->nd_opt_type) { 1474 case ND_OPT_TARGET_LINKADDR: 1475 case ND_OPT_REDIRECTED_HEADER: 1476 case ND_OPT_RDNSS: 1477 case ND_OPT_DNSSL: 1478 break; /* we don't care about these options */ 1479 case ND_OPT_SOURCE_LINKADDR: 1480 case ND_OPT_MTU: 1481 if (ndopts->opt_array[hdr->nd_opt_type]) { 1482 syslog(LOG_INFO, 1483 "<%s> duplicated ND option (type = %d)", 1484 __func__, hdr->nd_opt_type); 1485 } 1486 ndopts->opt_array[hdr->nd_opt_type] = hdr; 1487 break; 1488 case ND_OPT_PREFIX_INFORMATION: 1489 { 1490 struct nd_optlist *nol; 1491 1492 if (ndopts->opt_pi == 0) { 1493 ndopts->opt_pi = 1494 (struct nd_opt_prefix_info *)hdr; 1495 continue; 1496 } 1497 nol = malloc(sizeof(*nol)); 1498 if (nol == NULL) { 1499 syslog(LOG_ERR, "<%s> can't allocate memory", 1500 __func__); 1501 goto bad; 1502 } 1503 nol->nol_opt = hdr; 1504 TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next); 1505 1506 break; 1507 } 1508 default: /* impossible */ 1509 break; 1510 } 1511 } 1512 1513 return (0); 1514 1515 bad: 1516 free_ndopts(ndopts); 1517 1518 return (-1); 1519 } 1520 1521 static void 1522 free_ndopts(union nd_opt *ndopts) 1523 { 1524 struct nd_optlist *nol; 1525 1526 while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) { 1527 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next); 1528 free(nol); 1529 } 1530 } 1531 1532 void 1533 sock_open(struct sockinfo *s) 1534 { 1535 struct icmp6_filter filt; 1536 int on; 1537 /* XXX: should be max MTU attached to the node */ 1538 static char answer[1500]; 1539 1540 syslog(LOG_DEBUG, "<%s> enter", __func__); 1541 1542 if (s == NULL) { 1543 syslog(LOG_ERR, "<%s> internal error", __func__); 1544 exit(1); 1545 } 1546 rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + 1547 CMSG_SPACE(sizeof(int)); 1548 rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen); 1549 if (rcvcmsgbuf == NULL) { 1550 syslog(LOG_ERR, "<%s> not enough core", __func__); 1551 exit(1); 1552 } 1553 1554 sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + 1555 CMSG_SPACE(sizeof(int)); 1556 sndcmsgbuf = (char *)malloc(sndcmsgbuflen); 1557 if (sndcmsgbuf == NULL) { 1558 syslog(LOG_ERR, "<%s> not enough core", __func__); 1559 exit(1); 1560 } 1561 1562 if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { 1563 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno)); 1564 exit(1); 1565 } 1566 /* specify to tell receiving interface */ 1567 on = 1; 1568 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, 1569 sizeof(on)) < 0) { 1570 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__, 1571 strerror(errno)); 1572 exit(1); 1573 } 1574 on = 1; 1575 /* specify to tell value of hoplimit field of received IP6 hdr */ 1576 if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, 1577 sizeof(on)) < 0) { 1578 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__, 1579 strerror(errno)); 1580 exit(1); 1581 } 1582 ICMP6_FILTER_SETBLOCKALL(&filt); 1583 ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt); 1584 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); 1585 if (mcastif != NULL) 1586 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt); 1587 1588 if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, 1589 sizeof(filt)) < 0) { 1590 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s", 1591 __func__, strerror(errno)); 1592 exit(1); 1593 } 1594 1595 /* initialize msghdr for receiving packets */ 1596 rcviov[0].iov_base = (caddr_t)answer; 1597 rcviov[0].iov_len = sizeof(answer); 1598 rcvmhdr.msg_name = (caddr_t)&rcvfrom; 1599 rcvmhdr.msg_namelen = sizeof(rcvfrom); 1600 rcvmhdr.msg_iov = rcviov; 1601 rcvmhdr.msg_iovlen = 1; 1602 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf; 1603 rcvmhdr.msg_controllen = rcvcmsgbuflen; 1604 1605 /* initialize msghdr for sending packets */ 1606 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); 1607 sndmhdr.msg_iov = sndiov; 1608 sndmhdr.msg_iovlen = 1; 1609 sndmhdr.msg_control = (caddr_t)sndcmsgbuf; 1610 sndmhdr.msg_controllen = sndcmsgbuflen; 1611 1612 return; 1613 } 1614 1615 /* open a routing socket to watch the routing table */ 1616 static void 1617 rtsock_open(struct sockinfo *s) 1618 { 1619 if (s == NULL) { 1620 syslog(LOG_ERR, "<%s> internal error", __func__); 1621 exit(1); 1622 } 1623 if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) { 1624 syslog(LOG_ERR, 1625 "<%s> socket: %s", __func__, strerror(errno)); 1626 exit(1); 1627 } 1628 } 1629 1630 struct ifinfo * 1631 if_indextoifinfo(int idx) 1632 { 1633 struct ifinfo *ifi; 1634 1635 TAILQ_FOREACH(ifi, &ifilist, ifi_next) { 1636 if (ifi->ifi_ifindex == idx) 1637 return (ifi); 1638 } 1639 1640 if (ifi != NULL) 1641 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)", 1642 __func__, idx); 1643 else 1644 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)", 1645 __func__, idx); 1646 1647 return (NULL); /* search failed */ 1648 } 1649 1650 void 1651 ra_output(struct ifinfo *ifi) 1652 { 1653 int i; 1654 struct cmsghdr *cm; 1655 struct in6_pktinfo *pi; 1656 struct soliciter *sol; 1657 struct rainfo *rai; 1658 1659 switch (ifi->ifi_state) { 1660 case IFI_STATE_CONFIGURED: 1661 rai = ifi->ifi_rainfo; 1662 break; 1663 case IFI_STATE_TRANSITIVE: 1664 rai = ifi->ifi_rainfo_trans; 1665 break; 1666 case IFI_STATE_UNCONFIGURED: 1667 syslog(LOG_DEBUG, "<%s> %s is unconfigured. " 1668 "Skip sending RAs.", 1669 __func__, ifi->ifi_ifname); 1670 return; 1671 default: 1672 rai = NULL; 1673 } 1674 if (rai == NULL) { 1675 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s." 1676 "Skip sending RAs.", 1677 __func__, ifi->ifi_ifname); 1678 return; 1679 } 1680 if (!(ifi->ifi_flags & IFF_UP)) { 1681 syslog(LOG_DEBUG, "<%s> %s is not up. " 1682 "Skip sending RAs.", 1683 __func__, ifi->ifi_ifname); 1684 return; 1685 } 1686 /* 1687 * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding. 1688 * 1689 * (lifetime == 0) = output 1690 * (lifetime != 0 && (check_accept_rtadv()) = no output 1691 * 1692 * Basically, hosts MUST NOT send Router Advertisement 1693 * messages at any time (RFC 4861, Section 6.2.3). However, it 1694 * would sometimes be useful to allow hosts to advertise some 1695 * parameters such as prefix information and link MTU. Thus, 1696 * we allow hosts to invoke rtadvd only when router lifetime 1697 * (on every advertising interface) is explicitly set 1698 * zero. (see also the above section) 1699 */ 1700 syslog(LOG_DEBUG, 1701 "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d " 1702 "on %s", __func__, 1703 rai->rai_lifetime, 1704 check_accept_rtadv(ifi->ifi_ifindex), 1705 getinet6sysctl(IPV6CTL_FORWARDING), 1706 ifi->ifi_ifname); 1707 1708 if (rai->rai_lifetime != 0) { 1709 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) { 1710 syslog(LOG_ERR, 1711 "non-zero lifetime RA " 1712 "but net.inet6.ip6.forwarding=0. " 1713 "Ignored."); 1714 return; 1715 } 1716 if (check_accept_rtadv(ifi->ifi_ifindex)) { 1717 syslog(LOG_ERR, 1718 "non-zero lifetime RA " 1719 "on RA receiving interface %s." 1720 " Ignored.", ifi->ifi_ifname); 1721 return; 1722 } 1723 } 1724 1725 make_packet(rai); /* XXX: inefficient */ 1726 1727 sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes; 1728 sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data; 1729 sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen; 1730 1731 cm = CMSG_FIRSTHDR(&sndmhdr); 1732 /* specify the outgoing interface */ 1733 cm->cmsg_level = IPPROTO_IPV6; 1734 cm->cmsg_type = IPV6_PKTINFO; 1735 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 1736 pi = (struct in6_pktinfo *)CMSG_DATA(cm); 1737 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ 1738 pi->ipi6_ifindex = ifi->ifi_ifindex; 1739 1740 /* specify the hop limit of the packet */ 1741 { 1742 int hoplimit = 255; 1743 1744 cm = CMSG_NXTHDR(&sndmhdr, cm); 1745 cm->cmsg_level = IPPROTO_IPV6; 1746 cm->cmsg_type = IPV6_HOPLIMIT; 1747 cm->cmsg_len = CMSG_LEN(sizeof(int)); 1748 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int)); 1749 } 1750 1751 syslog(LOG_DEBUG, 1752 "<%s> send RA on %s, # of RS waitings = %d", 1753 __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount); 1754 1755 i = sendmsg(sock.si_fd, &sndmhdr, 0); 1756 1757 if (i < 0 || (size_t)i != rai->rai_ra_datalen) { 1758 if (i < 0) { 1759 syslog(LOG_ERR, "<%s> sendmsg on %s: %s", 1760 __func__, ifi->ifi_ifname, 1761 strerror(errno)); 1762 } 1763 } 1764 1765 /* 1766 * unicast advertisements 1767 * XXX commented out. reason: though spec does not forbit it, unicast 1768 * advert does not really help 1769 */ 1770 while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) { 1771 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next); 1772 free(sol); 1773 } 1774 1775 /* update timestamp */ 1776 gettimeofday(&ifi->ifi_ra_lastsent, NULL); 1777 1778 /* update counter */ 1779 ifi->ifi_rs_waitcount = 0; 1780 ifi->ifi_raoutput++; 1781 1782 switch (ifi->ifi_state) { 1783 case IFI_STATE_CONFIGURED: 1784 if (ifi->ifi_burstcount > 0) 1785 ifi->ifi_burstcount--; 1786 break; 1787 case IFI_STATE_TRANSITIVE: 1788 ifi->ifi_burstcount--; 1789 if (ifi->ifi_burstcount == 0) { 1790 if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) { 1791 /* Initial burst finished. */ 1792 if (ifi->ifi_rainfo_trans != NULL) 1793 ifi->ifi_rainfo_trans = NULL; 1794 } 1795 1796 /* Remove burst RA information */ 1797 if (ifi->ifi_rainfo_trans != NULL) { 1798 rm_rainfo(ifi->ifi_rainfo_trans); 1799 ifi->ifi_rainfo_trans = NULL; 1800 } 1801 1802 if (ifi->ifi_rainfo != NULL) { 1803 /* 1804 * TRANSITIVE -> CONFIGURED 1805 * 1806 * After initial burst or transition from 1807 * one configuration to another, 1808 * ifi_rainfo always points to the next RA 1809 * information. 1810 */ 1811 ifi->ifi_state = IFI_STATE_CONFIGURED; 1812 syslog(LOG_DEBUG, 1813 "<%s> ifname=%s marked as " 1814 "CONFIGURED.", __func__, 1815 ifi->ifi_ifname); 1816 } else { 1817 /* 1818 * TRANSITIVE -> UNCONFIGURED 1819 * 1820 * If ifi_rainfo points to NULL, this 1821 * interface is shutting down. 1822 * 1823 */ 1824 int error; 1825 1826 ifi->ifi_state = IFI_STATE_UNCONFIGURED; 1827 syslog(LOG_DEBUG, 1828 "<%s> ifname=%s marked as " 1829 "UNCONFIGURED.", __func__, 1830 ifi->ifi_ifname); 1831 error = sock_mc_leave(&sock, 1832 ifi->ifi_ifindex); 1833 if (error) 1834 exit(1); 1835 } 1836 } 1837 break; 1838 } 1839 } 1840 1841 /* process RA timer */ 1842 struct rtadvd_timer * 1843 ra_timeout(void *arg) 1844 { 1845 struct ifinfo *ifi; 1846 1847 ifi = (struct ifinfo *)arg; 1848 syslog(LOG_DEBUG, "<%s> RA timer on %s is expired", 1849 __func__, ifi->ifi_ifname); 1850 1851 ra_output(ifi); 1852 1853 return (ifi->ifi_ra_timer); 1854 } 1855 1856 /* update RA timer */ 1857 void 1858 ra_timer_update(void *arg, struct timeval *tm) 1859 { 1860 uint16_t interval; 1861 struct rainfo *rai; 1862 struct ifinfo *ifi; 1863 1864 ifi = (struct ifinfo *)arg; 1865 rai = ifi->ifi_rainfo; 1866 interval = 0; 1867 1868 switch (ifi->ifi_state) { 1869 case IFI_STATE_UNCONFIGURED: 1870 return; 1871 break; 1872 case IFI_STATE_CONFIGURED: 1873 /* 1874 * Whenever a multicast advertisement is sent from 1875 * an interface, the timer is reset to a 1876 * uniformly-distributed random value between the 1877 * interface's configured MinRtrAdvInterval and 1878 * MaxRtrAdvInterval (RFC4861 6.2.4). 1879 */ 1880 interval = rai->rai_mininterval; 1881 #ifdef HAVE_ARC4RANDOM 1882 interval += arc4random_uniform(rai->rai_maxinterval - 1883 rai->rai_mininterval); 1884 #else 1885 interval += random() % (rai->rai_maxinterval - 1886 rai->rai_mininterval); 1887 #endif 1888 break; 1889 case IFI_STATE_TRANSITIVE: 1890 /* 1891 * For the first few advertisements (up to 1892 * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen 1893 * interval is greater than 1894 * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be 1895 * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead. (RFC 1896 * 4861 6.2.4) 1897 * 1898 * In such cases, the router SHOULD transmit one or more 1899 * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final 1900 * multicast Router Advertisements on the interface with a 1901 * Router Lifetime field of zero. (RFC 4861 6.2.5) 1902 */ 1903 interval = ifi->ifi_burstinterval; 1904 break; 1905 } 1906 1907 tm->tv_sec = interval; 1908 tm->tv_usec = 0; 1909 1910 syslog(LOG_DEBUG, 1911 "<%s> RA timer on %s is set to %ld:%ld", 1912 __func__, ifi->ifi_ifname, 1913 (long int)tm->tv_sec, (long int)tm->tv_usec); 1914 1915 return; 1916 } 1917