usr.sbin/rtadvd/rtadvd.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */
   3
   4 /*-
   5  * SPDX-License-Identifier: BSD-3-Clause
   6  *
   7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   8  * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the project nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/socket.h>
  39 #include <sys/uio.h>
  40 #include <sys/queue.h>
  41 #include <sys/stat.h>
  42 #include <sys/sysctl.h>
  43
  44 #include <net/if.h>
  45 #include <net/if_types.h>
  46 #include <net/if_media.h>
  47 #include <net/if_dl.h>
  48 #include <net/route.h>
  49 #include <netinet/in.h>
  50 #include <netinet/ip6.h>
  51 #include <netinet6/ip6_var.h>
  52 #include <netinet/icmp6.h>
  53
  54 #include <arpa/inet.h>
  55
  56 #include <netinet/in_var.h>
  57 #include <netinet6/nd6.h>
  58
  59 #include <time.h>
  60 #include <unistd.h>
  61 #include <stdio.h>
  62 #include <err.h>
  63 #include <errno.h>
  64 #include <inttypes.h>
  65 #include <libutil.h>
  66 #include <netdb.h>
  67 #include <signal.h>
  68 #include <string.h>
  69 #include <stdlib.h>
  70 #include <syslog.h>
  71 #include <poll.h>
  72
  73 #include "pathnames.h"
  74 #include "rtadvd.h"
  75 #include "if.h"
  76 #include "rrenum.h"
  77 #include "advcap.h"
  78 #include "timer_subr.h"
  79 #include "timer.h"
  80 #include "config.h"
  81 #include "control.h"
  82 #include "control_server.h"
  83
  84 #define RTADV_TYPE2BITMASK(type) (0x1 << type)
  85
  86 struct msghdr rcvmhdr;
  87 static char *rcvcmsgbuf;
  88 static size_t rcvcmsgbuflen;
  89 static char *sndcmsgbuf = NULL;
  90 static size_t sndcmsgbuflen;
  91 struct msghdr sndmhdr;
  92 struct iovec rcviov[2];
  93 struct iovec sndiov[2];
  94 struct sockaddr_in6 rcvfrom;
  95 static const char *pidfilename = _PATH_RTADVDPID;
  96 const char *conffile = _PATH_RTADVDCONF;
  97 static struct pidfh *pfh;
  98 static int dflag, sflag;
  99 static int wait_shutdown;
 100
 101 #define PFD_RAWSOCK     0
 102 #define PFD_RTSOCK      1
 103 #define PFD_CSOCK       2
 104 #define PFD_MAX         3
 105
 106 struct railist_head_t railist =
 107     TAILQ_HEAD_INITIALIZER(railist);
 108 struct ifilist_head_t ifilist =
 109     TAILQ_HEAD_INITIALIZER(ifilist);
 110
 111 struct nd_optlist {
 112         TAILQ_ENTRY(nd_optlist) nol_next;
 113         struct nd_opt_hdr *nol_opt;
 114 };
 115 union nd_opt {
 116         struct nd_opt_hdr *opt_array[9];
 117         struct {
 118                 struct nd_opt_hdr *zero;
 119                 struct nd_opt_hdr *src_lladdr;
 120                 struct nd_opt_hdr *tgt_lladdr;
 121                 struct nd_opt_prefix_info *pi;
 122                 struct nd_opt_rd_hdr *rh;
 123                 struct nd_opt_mtu *mtu;
 124                 TAILQ_HEAD(, nd_optlist) opt_list;
 125         } nd_opt_each;
 126 };
 127 #define opt_src_lladdr  nd_opt_each.src_lladdr
 128 #define opt_tgt_lladdr  nd_opt_each.tgt_lladdr
 129 #define opt_pi          nd_opt_each.pi
 130 #define opt_rh          nd_opt_each.rh
 131 #define opt_mtu         nd_opt_each.mtu
 132 #define opt_list        nd_opt_each.opt_list
 133
 134 #define NDOPT_FLAG_SRCLINKADDR  (1 << 0)
 135 #define NDOPT_FLAG_TGTLINKADDR  (1 << 1)
 136 #define NDOPT_FLAG_PREFIXINFO   (1 << 2)
 137 #define NDOPT_FLAG_RDHDR        (1 << 3)
 138 #define NDOPT_FLAG_MTU          (1 << 4)
 139 #define NDOPT_FLAG_RDNSS        (1 << 5)
 140 #define NDOPT_FLAG_DNSSL        (1 << 6)
 141
 142 static uint32_t ndopt_flags[] = {
 143         [ND_OPT_SOURCE_LINKADDR]        = NDOPT_FLAG_SRCLINKADDR,
 144         [ND_OPT_TARGET_LINKADDR]        = NDOPT_FLAG_TGTLINKADDR,
 145         [ND_OPT_PREFIX_INFORMATION]     = NDOPT_FLAG_PREFIXINFO,
 146         [ND_OPT_REDIRECTED_HEADER]      = NDOPT_FLAG_RDHDR,
 147         [ND_OPT_MTU]                    = NDOPT_FLAG_MTU,
 148         [ND_OPT_RDNSS]                  = NDOPT_FLAG_RDNSS,
 149         [ND_OPT_DNSSL]                  = NDOPT_FLAG_DNSSL,
 150 };
 151
 152 static void     rtadvd_shutdown(void);
 153 static void     sock_open(struct sockinfo *);
 154 static void     rtsock_open(struct sockinfo *);
 155 static void     rtadvd_input(struct sockinfo *);
 156 static void     rs_input(int, struct nd_router_solicit *,
 157                     struct in6_pktinfo *, struct sockaddr_in6 *);
 158 static void     ra_input(int, struct nd_router_advert *,
 159                     struct in6_pktinfo *, struct sockaddr_in6 *);
 160 static int      prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
 161                     struct sockaddr_in6 *);
 162 static int      nd6_options(struct nd_opt_hdr *, int,
 163                     union nd_opt *, uint32_t);
 164 static void     free_ndopts(union nd_opt *);
 165 static void     rtmsg_input(struct sockinfo *);
 166 static void     set_short_delay(struct ifinfo *);
 167 static int      check_accept_rtadv(int);
 168
 169 static void
 170 usage(void)
 171 {
 172
 173         fprintf(stderr, "usage: rtadvd [-dDfRs] "
 174             "[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n");
 175         exit(1);
 176 }
 177
 178 int
 179 main(int argc, char *argv[])
 180 {
 181         struct pollfd set[PFD_MAX];
 182         struct timespec *timeout;
 183         int i, ch;
 184         int fflag = 0, logopt;
 185         int error;
 186         pid_t pid, otherpid;
 187
 188         /* get command line options and arguments */
 189         while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) {
 190                 switch (ch) {
 191                 case 'c':
 192                         conffile = optarg;
 193                         break;
 194                 case 'C':
 195                         ctrlsock.si_name = optarg;
 196                         break;
 197                 case 'd':
 198                         dflag++;
 199                         break;
 200                 case 'D':
 201                         dflag += 3;
 202                         break;
 203                 case 'f':
 204                         fflag = 1;
 205                         break;
 206                 case 'M':
 207                         mcastif = optarg;
 208                         break;
 209                 case 'R':
 210                         fprintf(stderr, "rtadvd: "
 211                                 "the -R option is currently ignored.\n");
 212                         /* accept_rr = 1; */
 213                         /* run anyway... */
 214                         break;
 215                 case 's':
 216                         sflag = 1;
 217                         break;
 218                 case 'p':
 219                         pidfilename = optarg;
 220                         break;
 221                 default:
 222                         usage();
 223                 }
 224         }
 225         argc -= optind;
 226         argv += optind;
 227
 228         logopt = LOG_NDELAY | LOG_PID;
 229         if (fflag)
 230                 logopt |= LOG_PERROR;
 231         openlog("rtadvd", logopt, LOG_DAEMON);
 232
 233         /* set log level */
 234         if (dflag > 2)
 235                 (void)setlogmask(LOG_UPTO(LOG_DEBUG));
 236         else if (dflag > 1)
 237                 (void)setlogmask(LOG_UPTO(LOG_INFO));
 238         else if (dflag > 0)
 239                 (void)setlogmask(LOG_UPTO(LOG_NOTICE));
 240         else
 241                 (void)setlogmask(LOG_UPTO(LOG_ERR));
 242
 243         /* timer initialization */
 244         rtadvd_timer_init();
 245
 246         pfh = pidfile_open(pidfilename, 0600, &otherpid);
 247         if (pfh == NULL) {
 248                 if (errno == EEXIST)
 249                         errx(1, "%s already running, pid: %d",
 250                             getprogname(), otherpid);
 251                 syslog(LOG_ERR,
 252                     "failed to open the pid file %s, run anyway.",
 253                     pidfilename);
 254         }
 255         if (!fflag)
 256                 daemon(1, 0);
 257
 258         sock_open(&sock);
 259
 260         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 261         for (i = 0; i < argc; i++)
 262                 update_persist_ifinfo(&ifilist, argv[i]);
 263
 264         csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 265         if (ctrlsock.si_fd == -1) {
 266                 syslog(LOG_ERR, "cannot open control socket: %s",
 267                     strerror(errno));
 268                 exit(1);
 269         }
 270
 271         /* record the current PID */
 272         pid = getpid();
 273         pidfile_write(pfh);
 274
 275         set[PFD_RAWSOCK].fd = sock.si_fd;
 276         set[PFD_RAWSOCK].events = POLLIN;
 277         if (sflag == 0) {
 278                 rtsock_open(&rtsock);
 279                 set[PFD_RTSOCK].fd = rtsock.si_fd;
 280                 set[PFD_RTSOCK].events = POLLIN;
 281         } else
 282                 set[PFD_RTSOCK].fd = -1;
 283         set[PFD_CSOCK].fd = ctrlsock.si_fd;
 284         set[PFD_CSOCK].events = POLLIN;
 285         signal(SIGTERM, set_do_shutdown);
 286         signal(SIGINT, set_do_shutdown);
 287         signal(SIGHUP, set_do_reload);
 288
 289         error = csock_listen(&ctrlsock);
 290         if (error) {
 291                 syslog(LOG_ERR, "cannot listen control socket: %s",
 292                     strerror(errno));
 293                 exit(1);
 294         }
 295
 296         /* load configuration file */
 297         set_do_reload(0);
 298
 299         while (1) {
 300                 if (is_do_shutdown())
 301                         rtadvd_shutdown();
 302
 303                 if (is_do_reload()) {
 304                         loadconfig_ifname(reload_ifname());
 305                         if (reload_ifname() == NULL)
 306                                 syslog(LOG_INFO,
 307                                     "configuration file reloaded.");
 308                         else
 309                                 syslog(LOG_INFO,
 310                                     "configuration file for %s reloaded.",
 311                                     reload_ifname());
 312                         reset_do_reload();
 313                 }
 314
 315                 /* timeout handler update for active interfaces */
 316                 rtadvd_update_timeout_handler();
 317
 318                 /* timer expiration check and reset the timer */
 319                 timeout = rtadvd_check_timer();
 320
 321                 if (timeout != NULL) {
 322                         syslog(LOG_DEBUG,
 323                             "<%s> set timer to %ld:%ld. waiting for "
 324                             "inputs or timeout", __func__,
 325                             (long int)timeout->tv_sec,
 326                             (long int)timeout->tv_nsec / 1000);
 327                 } else {
 328                         syslog(LOG_DEBUG,
 329                             "<%s> there's no timer. waiting for inputs",
 330                             __func__);
 331                 }
 332                 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
 333                             timeout ? (timeout->tv_sec * 1000 +
 334                                 timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
 335
 336                         /* EINTR would occur if a signal was delivered */
 337                         if (errno != EINTR)
 338                                 syslog(LOG_ERR, "poll() failed: %s",
 339                                     strerror(errno));
 340                         continue;
 341                 }
 342                 if (i == 0)     /* timeout */
 343                         continue;
 344                 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
 345                         rtmsg_input(&rtsock);
 346
 347                 if (set[PFD_RAWSOCK].revents & POLLIN)
 348                         rtadvd_input(&sock);
 349
 350                 if (set[PFD_CSOCK].revents & POLLIN) {
 351                         int fd;
 352
 353                         fd = csock_accept(&ctrlsock);
 354                         if (fd == -1)
 355                                 syslog(LOG_ERR,
 356                                     "cannot accept() control socket: %s",
 357                                     strerror(errno));
 358                         else {
 359                                 cm_handler_server(fd);
 360                                 close(fd);
 361                         }
 362                 }
 363         }
 364         exit(0);                /* NOTREACHED */
 365 }
 366
 367 static void
 368 rtadvd_shutdown(void)
 369 {
 370         struct ifinfo *ifi;
 371         struct rainfo *rai;
 372         struct rdnss *rdn;
 373         struct dnssl *dns;
 374
 375         if (wait_shutdown) {
 376                 syslog(LOG_INFO,
 377                     "waiting expiration of the all RA timers.");
 378
 379                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 380                         /*
 381                          * Ignore !IFF_UP interfaces in waiting for shutdown.
 382                          */
 383                         if (!(ifi->ifi_flags & IFF_UP) &&
 384                             ifi->ifi_ra_timer != NULL) {
 385                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 386                                 rtadvd_remove_timer(ifi->ifi_ra_timer);
 387                                 ifi->ifi_ra_timer = NULL;
 388                                 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
 389                                     "Timer removed and marked as UNCONFIGURED.",
 390                                      __func__, ifi->ifi_ifname,
 391                                     ifi->ifi_ifindex);
 392                         }
 393                 }
 394                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 395                         if (ifi->ifi_ra_timer != NULL)
 396                                 break;
 397                 }
 398                 if (ifi == NULL) {
 399                         syslog(LOG_NOTICE, "gracefully terminated.");
 400                         exit(0);
 401                 }
 402
 403                 sleep(1);
 404                 return;
 405         }
 406
 407         syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
 408             __func__);
 409
 410         wait_shutdown = 1;
 411
 412         TAILQ_FOREACH(rai, &railist, rai_next) {
 413                 rai->rai_lifetime = 0;
 414                 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
 415                         rdn->rd_ltime = 0;
 416                 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
 417                         dns->dn_ltime = 0;
 418         }
 419         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 420                 if (!ifi->ifi_persist)
 421                         continue;
 422                 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
 423                         continue;
 424                 if (ifi->ifi_ra_timer == NULL)
 425                         continue;
 426                 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
 427                     ifi->ifi_ra_lastsent.tv_nsec == 0 &&
 428                     ifi->ifi_ra_timer != NULL) {
 429                         /*
 430                          * When RA configured but never sent,
 431                          * ignore the IF immediately.
 432                          */
 433                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 434                         ifi->ifi_ra_timer = NULL;
 435                         ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 436                         continue;
 437                 }
 438
 439                 ifi->ifi_state = IFI_STATE_TRANSITIVE;
 440
 441                 /* Mark as the shut-down state. */
 442                 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
 443                 ifi->ifi_rainfo = NULL;
 444
 445                 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
 446                 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
 447
 448                 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 449                 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 450                     ifi->ifi_ra_timer);
 451         }
 452         syslog(LOG_NOTICE, "final RA transmission started.");
 453
 454         pidfile_remove(pfh);
 455         csock_close(&ctrlsock);
 456 }
 457
 458 static void
 459 rtmsg_input(struct sockinfo *s)
 460 {
 461         int n, type, ifindex = 0, plen;
 462         size_t len;
 463         char msg[2048], *next, *lim;
 464         char ifname[IFNAMSIZ];
 465         struct if_announcemsghdr *ifan;
 466         struct rt_msghdr *rtm;
 467         struct prefix *pfx;
 468         struct rainfo *rai;
 469         struct in6_addr *addr;
 470         struct ifinfo *ifi;
 471         char addrbuf[INET6_ADDRSTRLEN];
 472         int prefixchange = 0;
 473
 474         if (s == NULL) {
 475                 syslog(LOG_ERR, "<%s> internal error", __func__);
 476                 exit(1);
 477         }
 478         n = read(s->si_fd, msg, sizeof(msg));
 479         rtm = (struct rt_msghdr *)msg;
 480         syslog(LOG_DEBUG, "<%s> received a routing message "
 481             "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
 482
 483         if (n > rtm->rtm_msglen) {
 484                 /*
 485                  * This usually won't happen for messages received on
 486                  * a routing socket.
 487                  */
 488                 syslog(LOG_DEBUG,
 489                     "<%s> received data length is larger than "
 490                     "1st routing message len. multiple messages? "
 491                     "read %d bytes, but 1st msg len = %d",
 492                     __func__, n, rtm->rtm_msglen);
 493 #if 0
 494                 /* adjust length */
 495                 n = rtm->rtm_msglen;
 496 #endif
 497         }
 498
 499         lim = msg + n;
 500         for (next = msg; next < lim; next += len) {
 501                 int oldifflags;
 502
 503                 next = get_next_msg(next, lim, 0, &len,
 504                     RTADV_TYPE2BITMASK(RTM_ADD) |
 505                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 506                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 507                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 508                     RTADV_TYPE2BITMASK(RTM_IFINFO) |
 509                     RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
 510                 if (len == 0)
 511                         break;
 512                 type = ((struct rt_msghdr *)next)->rtm_type;
 513                 switch (type) {
 514                 case RTM_ADD:
 515                 case RTM_DELETE:
 516                         ifindex = get_rtm_ifindex(next);
 517                         break;
 518                 case RTM_NEWADDR:
 519                 case RTM_DELADDR:
 520                         ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
 521                         break;
 522                 case RTM_IFINFO:
 523                         ifindex = (int)((struct if_msghdr *)next)->ifm_index;
 524                         break;
 525                 case RTM_IFANNOUNCE:
 526                         ifan = (struct if_announcemsghdr *)next;
 527                         switch (ifan->ifan_what) {
 528                         case IFAN_ARRIVAL:
 529                         case IFAN_DEPARTURE:
 530                                 break;
 531                         default:
 532                                 syslog(LOG_DEBUG,
 533                                     "<%s:%d> unknown ifan msg (ifan_what=%d)",
 534                                    __func__, __LINE__, ifan->ifan_what);
 535                                 continue;
 536                         }
 537
 538                         syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
 539                                __func__, ifan->ifan_index, ifan->ifan_what);
 540                         switch (ifan->ifan_what) {
 541                         case IFAN_ARRIVAL:
 542                                 syslog(LOG_NOTICE,
 543                                     "interface added (idx=%d)",
 544                                     ifan->ifan_index);
 545                                 update_ifinfo(&ifilist, ifan->ifan_index);
 546                                 loadconfig_index(ifan->ifan_index);
 547                                 break;
 548                         case IFAN_DEPARTURE:
 549                                 syslog(LOG_NOTICE,
 550                                     "interface removed (idx=%d)",
 551                                     ifan->ifan_index);
 552                                 rm_ifinfo_index(ifan->ifan_index);
 553
 554                                 /* Clear ifi_ifindex */
 555                                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 556                                         if (ifi->ifi_ifindex
 557                                             == ifan->ifan_index) {
 558                                                 ifi->ifi_ifindex = 0;
 559                                                 break;
 560                                         }
 561                                 }
 562                                 update_ifinfo(&ifilist, ifan->ifan_index);
 563                                 break;
 564                         }
 565                         continue;
 566                 default:
 567                         /* should not reach here */
 568                         syslog(LOG_DEBUG,
 569                                "<%s:%d> unknown rtmsg %d on %s",
 570                                __func__, __LINE__, type,
 571                                if_indextoname(ifindex, ifname));
 572                         continue;
 573                 }
 574                 ifi = if_indextoifinfo(ifindex);
 575                 if (ifi == NULL) {
 576                         syslog(LOG_DEBUG,
 577                             "<%s> ifinfo not found for idx=%d.  Why?",
 578                             __func__, ifindex);
 579                         continue;
 580                 }
 581                 rai = ifi->ifi_rainfo;
 582                 if (rai == NULL) {
 583                         syslog(LOG_DEBUG,
 584                             "<%s> route changed on "
 585                             "non advertising interface(%s)",
 586                             __func__, ifi->ifi_ifname);
 587                         continue;
 588                 }
 589
 590                 oldifflags = ifi->ifi_flags;
 591                 /* init ifflags because it may have changed */
 592                 update_ifinfo(&ifilist, ifindex);
 593
 594                 switch (type) {
 595                 case RTM_ADD:
 596                         if (sflag)
 597                                 break;  /* we aren't interested in prefixes  */
 598
 599                         addr = get_addr(msg);
 600                         plen = get_prefixlen(msg);
 601                         /* sanity check for plen */
 602                         /* as RFC2373, prefixlen is at least 4 */
 603                         if (plen < 4 || plen > 127) {
 604                                 syslog(LOG_INFO, "<%s> new interface route's"
 605                                     "plen %d is invalid for a prefix",
 606                                     __func__, plen);
 607                                 break;
 608                         }
 609                         pfx = find_prefix(rai, addr, plen);
 610                         if (pfx) {
 611                                 if (pfx->pfx_timer) {
 612                                         /*
 613                                          * If the prefix has been invalidated,
 614                                          * make it available again.
 615                                          */
 616                                         update_prefix(pfx);
 617                                         prefixchange = 1;
 618                                 } else
 619                                         syslog(LOG_DEBUG,
 620                                             "<%s> new prefix(%s/%d) "
 621                                             "added on %s, "
 622                                             "but it was already in list",
 623                                             __func__,
 624                                             inet_ntop(AF_INET6, addr,
 625                                                 (char *)addrbuf,
 626                                                 sizeof(addrbuf)),
 627                                             plen, ifi->ifi_ifname);
 628                                 break;
 629                         }
 630                         make_prefix(rai, ifindex, addr, plen);
 631                         prefixchange = 1;
 632                         break;
 633                 case RTM_DELETE:
 634                         if (sflag)
 635                                 break;
 636
 637                         addr = get_addr(msg);
 638                         plen = get_prefixlen(msg);
 639                         /* sanity check for plen */
 640                         /* as RFC2373, prefixlen is at least 4 */
 641                         if (plen < 4 || plen > 127) {
 642                                 syslog(LOG_INFO,
 643                                     "<%s> deleted interface route's "
 644                                     "plen %d is invalid for a prefix",
 645                                     __func__, plen);
 646                                 break;
 647                         }
 648                         pfx = find_prefix(rai, addr, plen);
 649                         if (pfx == NULL) {
 650                                 syslog(LOG_DEBUG,
 651                                     "<%s> prefix(%s/%d) was deleted on %s, "
 652                                     "but it was not in list",
 653                                     __func__, inet_ntop(AF_INET6, addr,
 654                                         (char *)addrbuf, sizeof(addrbuf)),
 655                                         plen, ifi->ifi_ifname);
 656                                 break;
 657                         }
 658                         invalidate_prefix(pfx);
 659                         prefixchange = 1;
 660                         break;
 661                 case RTM_NEWADDR:
 662                 case RTM_DELADDR:
 663                 case RTM_IFINFO:
 664                         break;
 665                 default:
 666                         /* should not reach here */
 667                         syslog(LOG_DEBUG,
 668                             "<%s:%d> unknown rtmsg %d on %s",
 669                             __func__, __LINE__, type,
 670                             if_indextoname(ifindex, ifname));
 671                         return;
 672                 }
 673
 674                 /* check if an interface flag is changed */
 675                 if ((oldifflags & IFF_UP) && /* UP to DOWN */
 676                     !(ifi->ifi_flags & IFF_UP)) {
 677                         syslog(LOG_NOTICE,
 678                             "<interface %s becomes down. stop timer.",
 679                             ifi->ifi_ifname);
 680                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 681                         ifi->ifi_ra_timer = NULL;
 682                 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
 683                     (ifi->ifi_flags & IFF_UP)) {
 684                         syslog(LOG_NOTICE,
 685                             "interface %s becomes up. restart timer.",
 686                             ifi->ifi_ifname);
 687
 688                         ifi->ifi_state = IFI_STATE_TRANSITIVE;
 689                         ifi->ifi_burstcount =
 690                             MAX_INITIAL_RTR_ADVERTISEMENTS;
 691                         ifi->ifi_burstinterval =
 692                             MAX_INITIAL_RTR_ADVERT_INTERVAL;
 693
 694                         ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
 695                             ra_timer_update, ifi, ifi);
 696                         ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 697                         rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 698                             ifi->ifi_ra_timer);
 699                 } else if (prefixchange &&
 700                     (ifi->ifi_flags & IFF_UP)) {
 701                         /*
 702                          * An advertised prefix has been added or invalidated.
 703                          * Will notice the change in a short delay.
 704                          */
 705                         set_short_delay(ifi);
 706                 }
 707         }
 708
 709         return;
 710 }
 711
 712 void
 713 rtadvd_input(struct sockinfo *s)
 714 {
 715         ssize_t i;
 716         int *hlimp = NULL;
 717 #ifdef OLDRAWSOCKET
 718         struct ip6_hdr *ip;
 719 #endif
 720         struct icmp6_hdr *icp;
 721         int ifindex = 0;
 722         struct cmsghdr *cm;
 723         struct in6_pktinfo *pi = NULL;
 724         char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 725         struct in6_addr dst = in6addr_any;
 726         struct ifinfo *ifi;
 727
 728         syslog(LOG_DEBUG, "<%s> enter", __func__);
 729
 730         if (s == NULL) {
 731                 syslog(LOG_ERR, "<%s> internal error", __func__);
 732                 exit(1);
 733         }
 734         /*
 735          * Get message. We reset msg_controllen since the field could
 736          * be modified if we had received a message before setting
 737          * receive options.
 738          */
 739         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 740         if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
 741                 return;
 742
 743         /* extract optional information via Advanced API */
 744         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 745              cm;
 746              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 747                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 748                     cm->cmsg_type == IPV6_PKTINFO &&
 749                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 750                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 751                         ifindex = pi->ipi6_ifindex;
 752                         dst = pi->ipi6_addr;
 753                 }
 754                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 755                     cm->cmsg_type == IPV6_HOPLIMIT &&
 756                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 757                         hlimp = (int *)CMSG_DATA(cm);
 758         }
 759         if (ifindex == 0) {
 760                 syslog(LOG_ERR, "failed to get receiving interface");
 761                 return;
 762         }
 763         if (hlimp == NULL) {
 764                 syslog(LOG_ERR, "failed to get receiving hop limit");
 765                 return;
 766         }
 767
 768         /*
 769          * If we happen to receive data on an interface which is now gone
 770          * or down, just discard the data.
 771          */
 772         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 773         if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
 774                 syslog(LOG_INFO,
 775                     "<%s> received data on a disabled interface (%s)",
 776                     __func__,
 777                     (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
 778                 return;
 779         }
 780
 781 #ifdef OLDRAWSOCKET
 782         if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 783                 syslog(LOG_ERR,
 784                     "packet size(%d) is too short", i);
 785                 return;
 786         }
 787
 788         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 789         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 790 #else
 791         if ((size_t)i < sizeof(struct icmp6_hdr)) {
 792                 syslog(LOG_ERR, "packet size(%zd) is too short", i);
 793                 return;
 794         }
 795
 796         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 797 #endif
 798
 799         switch (icp->icmp6_type) {
 800         case ND_ROUTER_SOLICIT:
 801                 /*
 802                  * Message verification - RFC 4861 6.1.1
 803                  * XXX: these checks must be done in the kernel as well,
 804                  *      but we can't completely rely on them.
 805                  */
 806                 if (*hlimp != 255) {
 807                         syslog(LOG_NOTICE,
 808                             "RS with invalid hop limit(%d) "
 809                             "received from %s on %s",
 810                             *hlimp,
 811                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 812                             sizeof(ntopbuf)),
 813                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 814                         return;
 815                 }
 816                 if (icp->icmp6_code) {
 817                         syslog(LOG_NOTICE,
 818                             "RS with invalid ICMP6 code(%d) "
 819                             "received from %s on %s",
 820                             icp->icmp6_code,
 821                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 822                             sizeof(ntopbuf)),
 823                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 824                         return;
 825                 }
 826                 if ((size_t)i < sizeof(struct nd_router_solicit)) {
 827                         syslog(LOG_NOTICE,
 828                             "RS from %s on %s does not have enough "
 829                             "length (len = %zd)",
 830                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 831                             sizeof(ntopbuf)),
 832                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 833                         return;
 834                 }
 835                 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
 836                 break;
 837         case ND_ROUTER_ADVERT:
 838                 /*
 839                  * Message verification - RFC 4861 6.1.2
 840                  * XXX: there's the same dilemma as above...
 841                  */
 842                 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
 843                         syslog(LOG_NOTICE,
 844                             "RA with non-linklocal source address "
 845                             "received from %s on %s",
 846                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
 847                             ntopbuf, sizeof(ntopbuf)),
 848                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 849                         return;
 850                 }
 851                 if (*hlimp != 255) {
 852                         syslog(LOG_NOTICE,
 853                             "RA with invalid hop limit(%d) "
 854                             "received from %s on %s",
 855                             *hlimp,
 856                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 857                             sizeof(ntopbuf)),
 858                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 859                         return;
 860                 }
 861                 if (icp->icmp6_code) {
 862                         syslog(LOG_NOTICE,
 863                             "RA with invalid ICMP6 code(%d) "
 864                             "received from %s on %s",
 865                             icp->icmp6_code,
 866                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 867                             sizeof(ntopbuf)),
 868                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 869                         return;
 870                 }
 871                 if ((size_t)i < sizeof(struct nd_router_advert)) {
 872                         syslog(LOG_NOTICE,
 873                             "RA from %s on %s does not have enough "
 874                             "length (len = %zd)",
 875                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 876                             sizeof(ntopbuf)),
 877                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 878                         return;
 879                 }
 880                 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
 881                 break;
 882         case ICMP6_ROUTER_RENUMBERING:
 883                 if (mcastif == NULL) {
 884                         syslog(LOG_ERR, "received a router renumbering "
 885                             "message, but not allowed to be accepted");
 886                         break;
 887                 }
 888                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
 889                     &dst);
 890                 break;
 891         default:
 892                 /*
 893                  * Note that this case is POSSIBLE, especially just
 894                  * after invocation of the daemon. This is because we
 895                  * could receive message after opening the socket and
 896                  * before setting ICMP6 type filter(see sock_open()).
 897                  */
 898                 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
 899                 return;
 900         }
 901
 902         return;
 903 }
 904
 905 static void
 906 rs_input(int len, struct nd_router_solicit *rs,
 907          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 908 {
 909         char ntopbuf[INET6_ADDRSTRLEN];
 910         char ifnamebuf[IFNAMSIZ];
 911         union nd_opt ndopts;
 912         struct rainfo *rai;
 913         struct ifinfo *ifi;
 914         struct soliciter *sol;
 915
 916         syslog(LOG_DEBUG,
 917             "<%s> RS received from %s on %s",
 918             __func__,
 919             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
 920             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 921
 922         /* ND option check */
 923         memset(&ndopts, 0, sizeof(ndopts));
 924         TAILQ_INIT(&ndopts.opt_list);
 925         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 926                         len - sizeof(struct nd_router_solicit),
 927                         &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 928                 syslog(LOG_INFO,
 929                     "<%s> ND option check failed for an RS from %s on %s",
 930                     __func__,
 931                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
 932                         sizeof(ntopbuf)),
 933                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 934                 return;
 935         }
 936
 937         /*
 938          * If the IP source address is the unspecified address, there
 939          * must be no source link-layer address option in the message.
 940          * (RFC 4861 6.1.1)
 941          */
 942         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 943             ndopts.opt_src_lladdr) {
 944                 syslog(LOG_INFO,
 945                     "<%s> RS from unspecified src on %s has a link-layer"
 946                     " address option",
 947                     __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 948                 goto done;
 949         }
 950
 951         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 952         if (ifi == NULL) {
 953                 syslog(LOG_INFO,
 954                     "<%s> if (idx=%d) not found.  Why?",
 955                     __func__, pi->ipi6_ifindex);
 956                 goto done;
 957         }
 958         rai = ifi->ifi_rainfo;
 959         if (rai == NULL) {
 960                 syslog(LOG_INFO,
 961                        "<%s> RS received on non advertising interface(%s)",
 962                        __func__,
 963                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 964                 goto done;
 965         }
 966
 967         rai->rai_ifinfo->ifi_rsinput++;
 968
 969         /*
 970          * Decide whether to send RA according to the rate-limit
 971          * consideration.
 972          */
 973
 974         /* record sockaddr waiting for RA, if possible */
 975         sol = (struct soliciter *)malloc(sizeof(*sol));
 976         if (sol) {
 977                 sol->sol_addr = *from;
 978                 /* XXX RFC 2553 need clarification on flowinfo */
 979                 sol->sol_addr.sin6_flowinfo = 0;
 980                 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
 981         }
 982
 983         /*
 984          * If there is already a waiting RS packet, don't
 985          * update the timer.
 986          */
 987         if (ifi->ifi_rs_waitcount++)
 988                 goto done;
 989
 990         set_short_delay(ifi);
 991
 992   done:
 993         free_ndopts(&ndopts);
 994         return;
 995 }
 996
 997 static void
 998 set_short_delay(struct ifinfo *ifi)
 999 {
1000         long delay;     /* must not be greater than 1000000 */
1001         struct timespec interval, now, min_delay, tm_tmp, *rest;
1002
1003         if (ifi->ifi_ra_timer == NULL)
1004                 return;
1005         /*
1006          * Compute a random delay. If the computed value
1007          * corresponds to a time later than the time the next
1008          * multicast RA is scheduled to be sent, ignore the random
1009          * delay and send the advertisement at the
1010          * already-scheduled time. RFC 4861 6.2.6
1011          */
1012         delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1013         interval.tv_sec = 0;
1014         interval.tv_nsec = delay * 1000;
1015         rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1016         if (TS_CMP(rest, &interval, <)) {
1017                 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1018                     "the rest of the current timer", __func__);
1019                 interval = *rest;
1020         }
1021
1022         /*
1023          * If we sent a multicast Router Advertisement within
1024          * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1025          * the advertisement to be sent at a time corresponding to
1026          * MIN_DELAY_BETWEEN_RAS plus the random value after the
1027          * previous advertisement was sent.
1028          */
1029         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1030         TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1031         min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1032         min_delay.tv_nsec = 0;
1033         if (TS_CMP(&tm_tmp, &min_delay, <)) {
1034                 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1035                 TS_ADD(&min_delay, &interval, &interval);
1036         }
1037         rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1038 }
1039
1040 static int
1041 check_accept_rtadv(int idx)
1042 {
1043         struct ifinfo *ifi;
1044
1045         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1046                 if (ifi->ifi_ifindex == idx)
1047                         break;
1048         }
1049         if (ifi == NULL) {
1050                 syslog(LOG_DEBUG,
1051                     "<%s> if (idx=%d) not found.  Why?",
1052                     __func__, idx);
1053                 return (0);
1054         }
1055 #if (__FreeBSD_version < 900000)
1056         /*
1057          * RA_RECV: !ip6.forwarding && ip6.accept_rtadv
1058          * RA_SEND: ip6.forwarding
1059          */
1060         return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
1061             (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
1062 #else
1063         /*
1064          * RA_RECV: ND6_IFF_ACCEPT_RTADV
1065          * RA_SEND: ip6.forwarding
1066          */
1067         if (update_ifinfo_nd_flags(ifi) != 0) {
1068                 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1069                 return (0);
1070         }
1071
1072         return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1073 #endif
1074 }
1075
1076 static void
1077 ra_input(int len, struct nd_router_advert *nra,
1078          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1079 {
1080         struct rainfo *rai;
1081         struct ifinfo *ifi;
1082         char ntopbuf[INET6_ADDRSTRLEN];
1083         char ifnamebuf[IFNAMSIZ];
1084         union nd_opt ndopts;
1085         const char *on_off[] = {"OFF", "ON"};
1086         uint32_t reachabletime, retranstimer, mtu;
1087         int inconsistent = 0;
1088         int error;
1089
1090         syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1091             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1092             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1093
1094         /* ND option check */
1095         memset(&ndopts, 0, sizeof(ndopts));
1096         TAILQ_INIT(&ndopts.opt_list);
1097         error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1098             len - sizeof(struct nd_router_advert), &ndopts,
1099             NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1100             NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1101         if (error) {
1102                 syslog(LOG_INFO,
1103                     "<%s> ND option check failed for an RA from %s on %s",
1104                     __func__,
1105                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1106                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1107                         ifnamebuf));
1108                 return;
1109         }
1110
1111         /*
1112          * RA consistency check according to RFC 4861 6.2.7
1113          */
1114         ifi = if_indextoifinfo(pi->ipi6_ifindex);
1115         if (ifi->ifi_rainfo == NULL) {
1116                 syslog(LOG_INFO,
1117                     "<%s> received RA from %s on non-advertising"
1118                     " interface(%s)",
1119                     __func__,
1120                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1121                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1122                         ifnamebuf));
1123                 goto done;
1124         }
1125         rai = ifi->ifi_rainfo;
1126         ifi->ifi_rainput++;
1127         syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1128             ifi->ifi_rainput);
1129
1130         /* Cur Hop Limit value */
1131         if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1132             nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1133                 syslog(LOG_NOTICE,
1134                     "CurHopLimit inconsistent on %s:"
1135                     " %d from %s, %d from us",
1136                     ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1137                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1138                         sizeof(ntopbuf)), rai->rai_hoplimit);
1139                 inconsistent++;
1140         }
1141         /* M flag */
1142         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1143             rai->rai_managedflg) {
1144                 syslog(LOG_NOTICE,
1145                     "M flag inconsistent on %s:"
1146                     " %s from %s, %s from us",
1147                     ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1148                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1149                         sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1150                 inconsistent++;
1151         }
1152         /* O flag */
1153         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1154             rai->rai_otherflg) {
1155                 syslog(LOG_NOTICE,
1156                     "O flag inconsistent on %s:"
1157                     " %s from %s, %s from us",
1158                     ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1159                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1160                         sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1161                 inconsistent++;
1162         }
1163 #ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
1164         /* S "IPv6-Only" (Six, Silence-IPv4) flag */
1165         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_IPV6_ONLY) !=
1166             rai->rai_ipv6onlyflg) {
1167                 syslog(LOG_NOTICE,
1168                     "S flag inconsistent on %s:"
1169                     " %s from %s, %s from us",
1170                     ifi->ifi_ifname, on_off[!rai->rai_ipv6onlyflg],
1171                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1172                         sizeof(ntopbuf)), on_off[rai->rai_ipv6onlyflg]);
1173                 inconsistent++;
1174         }
1175 #endif
1176         /* Reachable Time */
1177         reachabletime = ntohl(nra->nd_ra_reachable);
1178         if (reachabletime && rai->rai_reachabletime &&
1179             reachabletime != rai->rai_reachabletime) {
1180                 syslog(LOG_NOTICE,
1181                     "ReachableTime inconsistent on %s:"
1182                     " %d from %s, %d from us",
1183                     ifi->ifi_ifname, reachabletime,
1184                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1185                         sizeof(ntopbuf)), rai->rai_reachabletime);
1186                 inconsistent++;
1187         }
1188         /* Retrans Timer */
1189         retranstimer = ntohl(nra->nd_ra_retransmit);
1190         if (retranstimer && rai->rai_retranstimer &&
1191             retranstimer != rai->rai_retranstimer) {
1192                 syslog(LOG_NOTICE,
1193                     "RetranceTimer inconsistent on %s:"
1194                     " %d from %s, %d from us",
1195                     ifi->ifi_ifname, retranstimer,
1196                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1197                         sizeof(ntopbuf)), rai->rai_retranstimer);
1198                 inconsistent++;
1199         }
1200         /* Values in the MTU options */
1201         if (ndopts.opt_mtu) {
1202                 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1203                 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1204                         syslog(LOG_NOTICE,
1205                             "MTU option value inconsistent on %s:"
1206                             " %d from %s, %d from us",
1207                             ifi->ifi_ifname, mtu,
1208                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1209                                 sizeof(ntopbuf)), rai->rai_linkmtu);
1210                         inconsistent++;
1211                 }
1212         }
1213         /* Preferred and Valid Lifetimes for prefixes */
1214         {
1215                 struct nd_optlist *nol;
1216
1217                 if (ndopts.opt_pi)
1218                         if (prefix_check(ndopts.opt_pi, rai, from))
1219                                 inconsistent++;
1220
1221                 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1222                         if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1223                                 rai, from))
1224                                 inconsistent++;
1225         }
1226
1227         if (inconsistent)
1228                 ifi->ifi_rainconsistent++;
1229
1230   done:
1231         free_ndopts(&ndopts);
1232         return;
1233 }
1234
1235 static uint32_t
1236 udiff(uint32_t u, uint32_t v)
1237 {
1238         return (u >= v ? u - v : v - u);
1239 }
1240
1241 /* return a non-zero value if the received prefix is inconsistent with ours */
1242 static int
1243 prefix_check(struct nd_opt_prefix_info *pinfo,
1244         struct rainfo *rai, struct sockaddr_in6 *from)
1245 {
1246         struct ifinfo *ifi;
1247         uint32_t preferred_time, valid_time;
1248         struct prefix *pfx;
1249         int inconsistent = 0;
1250         char ntopbuf[INET6_ADDRSTRLEN];
1251         char prefixbuf[INET6_ADDRSTRLEN];
1252         struct timespec now;
1253
1254 #if 0                           /* impossible */
1255         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1256                 return (0);
1257 #endif
1258         ifi = rai->rai_ifinfo;
1259         /*
1260          * log if the adveritsed prefix has link-local scope(sanity check?)
1261          */
1262         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1263                 syslog(LOG_INFO,
1264                     "<%s> link-local prefix %s/%d is advertised "
1265                     "from %s on %s",
1266                     __func__,
1267                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1268                         sizeof(prefixbuf)),
1269                     pinfo->nd_opt_pi_prefix_len,
1270                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1271                         sizeof(ntopbuf)), ifi->ifi_ifname);
1272
1273         if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1274                 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1275                 syslog(LOG_INFO,
1276                     "<%s> prefix %s/%d from %s on %s is not in our list",
1277                     __func__,
1278                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1279                         sizeof(prefixbuf)),
1280                     pinfo->nd_opt_pi_prefix_len,
1281                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1282                         sizeof(ntopbuf)), ifi->ifi_ifname);
1283                 return (0);
1284         }
1285
1286         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1287         if (pfx->pfx_pltimeexpire) {
1288                 /*
1289                  * The lifetime is decremented in real time, so we should
1290                  * compare the expiration time.
1291                  * (RFC 2461 Section 6.2.7.)
1292                  * XXX: can we really expect that all routers on the link
1293                  * have synchronized clocks?
1294                  */
1295                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1296                 preferred_time += now.tv_sec;
1297
1298                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1299                     udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1300                         syslog(LOG_INFO,
1301                             "<%s> preferred lifetime for %s/%d"
1302                             " (decr. in real time) inconsistent on %s:"
1303                             " %" PRIu32 " from %s, %" PRIu32 " from us",
1304                             __func__,
1305                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1306                                 sizeof(prefixbuf)),
1307                             pinfo->nd_opt_pi_prefix_len,
1308                             ifi->ifi_ifname, preferred_time,
1309                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1310                                 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1311                         inconsistent++;
1312                 }
1313         } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1314                 syslog(LOG_INFO,
1315                     "<%s> preferred lifetime for %s/%d"
1316                     " inconsistent on %s:"
1317                     " %d from %s, %d from us",
1318                     __func__,
1319                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1320                         sizeof(prefixbuf)),
1321                     pinfo->nd_opt_pi_prefix_len,
1322                     ifi->ifi_ifname, preferred_time,
1323                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1324                         sizeof(ntopbuf)), pfx->pfx_preflifetime);
1325
1326         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1327         if (pfx->pfx_vltimeexpire) {
1328                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1329                 valid_time += now.tv_sec;
1330
1331                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1332                     udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1333                         syslog(LOG_INFO,
1334                             "<%s> valid lifetime for %s/%d"
1335                             " (decr. in real time) inconsistent on %s:"
1336                             " %d from %s, %" PRIu32 " from us",
1337                             __func__,
1338                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1339                                 sizeof(prefixbuf)),
1340                             pinfo->nd_opt_pi_prefix_len,
1341                             ifi->ifi_ifname, preferred_time,
1342                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1343                                 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1344                         inconsistent++;
1345                 }
1346         } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1347                 syslog(LOG_INFO,
1348                     "<%s> valid lifetime for %s/%d"
1349                     " inconsistent on %s:"
1350                     " %d from %s, %d from us",
1351                     __func__,
1352                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1353                         sizeof(prefixbuf)),
1354                     pinfo->nd_opt_pi_prefix_len,
1355                     ifi->ifi_ifname, valid_time,
1356                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1357                         sizeof(ntopbuf)), pfx->pfx_validlifetime);
1358                 inconsistent++;
1359         }
1360
1361         return (inconsistent);
1362 }
1363
1364 struct prefix *
1365 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1366 {
1367         struct prefix *pfx;
1368         int bytelen, bitlen;
1369         char bitmask;
1370
1371         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1372                 if (plen != pfx->pfx_prefixlen)
1373                         continue;
1374
1375                 bytelen = plen / 8;
1376                 bitlen = plen % 8;
1377                 bitmask = 0xff << (8 - bitlen);
1378
1379                 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1380                         continue;
1381
1382                 if (bitlen == 0 ||
1383                     ((prefix->s6_addr[bytelen] & bitmask) ==
1384                      (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1385                         return (pfx);
1386                 }
1387         }
1388
1389         return (NULL);
1390 }
1391
1392 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1393 int
1394 prefix_match(struct in6_addr *p0, int plen0,
1395         struct in6_addr *p1, int plen1)
1396 {
1397         int bytelen, bitlen;
1398         char bitmask;
1399
1400         if (plen0 < plen1)
1401                 return (0);
1402
1403         bytelen = plen1 / 8;
1404         bitlen = plen1 % 8;
1405         bitmask = 0xff << (8 - bitlen);
1406
1407         if (memcmp((void *)p0, (void *)p1, bytelen))
1408                 return (0);
1409
1410         if (bitlen == 0 ||
1411             ((p0->s6_addr[bytelen] & bitmask) ==
1412              (p1->s6_addr[bytelen] & bitmask))) {
1413                 return (1);
1414         }
1415
1416         return (0);
1417 }
1418
1419 static int
1420 nd6_options(struct nd_opt_hdr *hdr, int limit,
1421         union nd_opt *ndopts, uint32_t optflags)
1422 {
1423         int optlen = 0;
1424
1425         for (; limit > 0; limit -= optlen) {
1426                 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1427                         syslog(LOG_INFO, "<%s> short option header", __func__);
1428                         goto bad;
1429                 }
1430
1431                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1432                 if (hdr->nd_opt_len == 0) {
1433                         syslog(LOG_INFO,
1434                             "<%s> bad ND option length(0) (type = %d)",
1435                             __func__, hdr->nd_opt_type);
1436                         goto bad;
1437                 }
1438                 optlen = hdr->nd_opt_len << 3;
1439                 if (optlen > limit) {
1440                         syslog(LOG_INFO, "<%s> short option", __func__);
1441                         goto bad;
1442                 }
1443
1444                 if (hdr->nd_opt_type > ND_OPT_MTU &&
1445                     hdr->nd_opt_type != ND_OPT_RDNSS &&
1446                     hdr->nd_opt_type != ND_OPT_DNSSL) {
1447                         syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1448                             __func__, hdr->nd_opt_type);
1449                         continue;
1450                 }
1451
1452                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1453                         syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1454                             __func__, hdr->nd_opt_type);
1455                         continue;
1456                 }
1457
1458                 /*
1459                  * Option length check.  Do it here for all fixed-length
1460                  * options.
1461                  */
1462                 switch (hdr->nd_opt_type) {
1463                 case ND_OPT_MTU:
1464                         if (optlen == sizeof(struct nd_opt_mtu))
1465                                 break;
1466                         goto skip;
1467                 case ND_OPT_RDNSS:
1468                         if (optlen >= 24 &&
1469                             (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1470                                 break;
1471                         goto skip;
1472                 case ND_OPT_DNSSL:
1473                         if (optlen >= 16 &&
1474                             (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1475                                 break;
1476                         goto skip;
1477                 case ND_OPT_PREFIX_INFORMATION:
1478                         if (optlen == sizeof(struct nd_opt_prefix_info))
1479                                 break;
1480 skip:
1481                         syslog(LOG_INFO, "<%s> invalid option length",
1482                             __func__);
1483                         continue;
1484                 }
1485
1486                 switch (hdr->nd_opt_type) {
1487                 case ND_OPT_TARGET_LINKADDR:
1488                 case ND_OPT_REDIRECTED_HEADER:
1489                 case ND_OPT_RDNSS:
1490                 case ND_OPT_DNSSL:
1491                         break;  /* we don't care about these options */
1492                 case ND_OPT_SOURCE_LINKADDR:
1493                 case ND_OPT_MTU:
1494                         if (ndopts->opt_array[hdr->nd_opt_type]) {
1495                                 syslog(LOG_INFO,
1496                                     "<%s> duplicated ND option (type = %d)",
1497                                     __func__, hdr->nd_opt_type);
1498                         }
1499                         ndopts->opt_array[hdr->nd_opt_type] = hdr;
1500                         break;
1501                 case ND_OPT_PREFIX_INFORMATION:
1502                 {
1503                         struct nd_optlist *nol;
1504
1505                         if (ndopts->opt_pi == 0) {
1506                                 ndopts->opt_pi =
1507                                     (struct nd_opt_prefix_info *)hdr;
1508                                 continue;
1509                         }
1510                         nol = malloc(sizeof(*nol));
1511                         if (nol == NULL) {
1512                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1513                                     __func__);
1514                                 goto bad;
1515                         }
1516                         nol->nol_opt = hdr;
1517                         TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1518
1519                         break;
1520                 }
1521                 default:        /* impossible */
1522                         break;
1523                 }
1524         }
1525
1526         return (0);
1527
1528   bad:
1529         free_ndopts(ndopts);
1530
1531         return (-1);
1532 }
1533
1534 static void
1535 free_ndopts(union nd_opt *ndopts)
1536 {
1537         struct nd_optlist *nol;
1538
1539         while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1540                 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1541                 free(nol);
1542         }
1543 }
1544
1545 void
1546 sock_open(struct sockinfo *s)
1547 {
1548         struct icmp6_filter filt;
1549         int on;
1550         /* XXX: should be max MTU attached to the node */
1551         static char answer[1500];
1552
1553         syslog(LOG_DEBUG, "<%s> enter", __func__);
1554
1555         if (s == NULL) {
1556                 syslog(LOG_ERR, "<%s> internal error", __func__);
1557                 exit(1);
1558         }
1559         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1560             CMSG_SPACE(sizeof(int));
1561         rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1562         if (rcvcmsgbuf == NULL) {
1563                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1564                 exit(1);
1565         }
1566
1567         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1568             CMSG_SPACE(sizeof(int));
1569         sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1570         if (sndcmsgbuf == NULL) {
1571                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1572                 exit(1);
1573         }
1574
1575         if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1576                 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1577                 exit(1);
1578         }
1579         /* specify to tell receiving interface */
1580         on = 1;
1581         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1582             sizeof(on)) < 0) {
1583                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1584                     strerror(errno));
1585                 exit(1);
1586         }
1587         on = 1;
1588         /* specify to tell value of hoplimit field of received IP6 hdr */
1589         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1590                 sizeof(on)) < 0) {
1591                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1592                     strerror(errno));
1593                 exit(1);
1594         }
1595         ICMP6_FILTER_SETBLOCKALL(&filt);
1596         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1597         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1598         if (mcastif != NULL)
1599                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1600
1601         if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1602             sizeof(filt)) < 0) {
1603                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1604                     __func__, strerror(errno));
1605                 exit(1);
1606         }
1607
1608         /* initialize msghdr for receiving packets */
1609         rcviov[0].iov_base = (caddr_t)answer;
1610         rcviov[0].iov_len = sizeof(answer);
1611         rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1612         rcvmhdr.msg_namelen = sizeof(rcvfrom);
1613         rcvmhdr.msg_iov = rcviov;
1614         rcvmhdr.msg_iovlen = 1;
1615         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1616         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1617
1618         /* initialize msghdr for sending packets */
1619         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1620         sndmhdr.msg_iov = sndiov;
1621         sndmhdr.msg_iovlen = 1;
1622         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1623         sndmhdr.msg_controllen = sndcmsgbuflen;
1624
1625         return;
1626 }
1627
1628 /* open a routing socket to watch the routing table */
1629 static void
1630 rtsock_open(struct sockinfo *s)
1631 {
1632         if (s == NULL) {
1633                 syslog(LOG_ERR, "<%s> internal error", __func__);
1634                 exit(1);
1635         }
1636         if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1637                 syslog(LOG_ERR,
1638                     "<%s> socket: %s", __func__, strerror(errno));
1639                 exit(1);
1640         }
1641 }
1642
1643 struct ifinfo *
1644 if_indextoifinfo(int idx)
1645 {
1646         struct ifinfo *ifi;
1647         char *name, name0[IFNAMSIZ];
1648
1649         /* Check if the interface has a valid name or not. */
1650         if (if_indextoname(idx, name0) == NULL)
1651                 return (NULL);
1652
1653         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1654                 if (ifi->ifi_ifindex == idx)
1655                         return (ifi);
1656         }
1657
1658         if (ifi != NULL)
1659                 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1660                     __func__, idx);
1661         else
1662                 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1663                     __func__, idx);
1664
1665         return (NULL);          /* search failed */
1666 }
1667
1668 void
1669 ra_output(struct ifinfo *ifi)
1670 {
1671         int i;
1672         struct cmsghdr *cm;
1673         struct in6_pktinfo *pi;
1674         struct soliciter *sol;
1675         struct rainfo *rai;
1676
1677         switch (ifi->ifi_state) {
1678         case IFI_STATE_CONFIGURED:
1679                 rai = ifi->ifi_rainfo;
1680                 break;
1681         case IFI_STATE_TRANSITIVE:
1682                 rai = ifi->ifi_rainfo_trans;
1683                 break;
1684         case IFI_STATE_UNCONFIGURED:
1685                 syslog(LOG_DEBUG, "<%s> %s is unconfigured.  "
1686                     "Skip sending RAs.",
1687                     __func__, ifi->ifi_ifname);
1688                 return;
1689         default:
1690                 rai = NULL;
1691         }
1692         if (rai == NULL) {
1693                 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1694                     "Skip sending RAs.",
1695                     __func__, ifi->ifi_ifname);
1696                 return;
1697         }
1698         if (!(ifi->ifi_flags & IFF_UP)) {
1699                 syslog(LOG_DEBUG, "<%s> %s is not up.  "
1700                     "Skip sending RAs.",
1701                     __func__, ifi->ifi_ifname);
1702                 return;
1703         }
1704         /*
1705          * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1706          *
1707          * (lifetime == 0) = output
1708          * (lifetime != 0 && (check_accept_rtadv()) = no output
1709          *
1710          * Basically, hosts MUST NOT send Router Advertisement
1711          * messages at any time (RFC 4861, Section 6.2.3). However, it
1712          * would sometimes be useful to allow hosts to advertise some
1713          * parameters such as prefix information and link MTU. Thus,
1714          * we allow hosts to invoke rtadvd only when router lifetime
1715          * (on every advertising interface) is explicitly set
1716          * zero. (see also the above section)
1717          */
1718         syslog(LOG_DEBUG,
1719             "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1720             "on %s", __func__,
1721             rai->rai_lifetime,
1722             check_accept_rtadv(ifi->ifi_ifindex),
1723             getinet6sysctl(IPV6CTL_FORWARDING),
1724             ifi->ifi_ifname);
1725
1726         if (rai->rai_lifetime != 0) {
1727                 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1728                         syslog(LOG_ERR,
1729                             "non-zero lifetime RA "
1730                             "but net.inet6.ip6.forwarding=0.  "
1731                             "Ignored.");
1732                         return;
1733                 }
1734                 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1735                         syslog(LOG_ERR,
1736                             "non-zero lifetime RA "
1737                             "on RA receiving interface %s."
1738                             "  Ignored.", ifi->ifi_ifname);
1739                         return;
1740                 }
1741         }
1742
1743         make_packet(rai);       /* XXX: inefficient */
1744
1745         sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1746         sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1747         sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1748
1749         cm = CMSG_FIRSTHDR(&sndmhdr);
1750         /* specify the outgoing interface */
1751         cm->cmsg_level = IPPROTO_IPV6;
1752         cm->cmsg_type = IPV6_PKTINFO;
1753         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1754         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1755         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1756         pi->ipi6_ifindex = ifi->ifi_ifindex;
1757
1758         /* specify the hop limit of the packet */
1759         {
1760                 int hoplimit = 255;
1761
1762                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1763                 cm->cmsg_level = IPPROTO_IPV6;
1764                 cm->cmsg_type = IPV6_HOPLIMIT;
1765                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1766                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1767         }
1768
1769         syslog(LOG_DEBUG,
1770             "<%s> send RA on %s, # of RS waitings = %d",
1771             __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1772
1773         i = sendmsg(sock.si_fd, &sndmhdr, 0);
1774
1775         if (i < 0 || (size_t)i != rai->rai_ra_datalen)  {
1776                 if (i < 0) {
1777                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1778                             __func__, ifi->ifi_ifname,
1779                             strerror(errno));
1780                 }
1781         }
1782
1783         /*
1784          * unicast advertisements
1785          * XXX commented out.  reason: though spec does not forbit it, unicast
1786          * advert does not really help
1787          */
1788         while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1789                 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1790                 free(sol);
1791         }
1792
1793         /* update timestamp */
1794         clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1795
1796         /* update counter */
1797         ifi->ifi_rs_waitcount = 0;
1798         ifi->ifi_raoutput++;
1799
1800         switch (ifi->ifi_state) {
1801         case IFI_STATE_CONFIGURED:
1802                 if (ifi->ifi_burstcount > 0)
1803                         ifi->ifi_burstcount--;
1804                 break;
1805         case IFI_STATE_TRANSITIVE:
1806                 ifi->ifi_burstcount--;
1807                 if (ifi->ifi_burstcount == 0) {
1808                         if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1809                                 /* Initial burst finished. */
1810                                 if (ifi->ifi_rainfo_trans != NULL)
1811                                         ifi->ifi_rainfo_trans = NULL;
1812                         }
1813
1814                         /* Remove burst RA information */
1815                         if (ifi->ifi_rainfo_trans != NULL) {
1816                                 rm_rainfo(ifi->ifi_rainfo_trans);
1817                                 ifi->ifi_rainfo_trans = NULL;
1818                         }
1819
1820                         if (ifi->ifi_rainfo != NULL) {
1821                                 /*
1822                                  * TRANSITIVE -> CONFIGURED
1823                                  *
1824                                  * After initial burst or transition from
1825                                  * one configuration to another,
1826                                  * ifi_rainfo always points to the next RA
1827                                  * information.
1828                                  */
1829                                 ifi->ifi_state = IFI_STATE_CONFIGURED;
1830                                 syslog(LOG_DEBUG,
1831                                     "<%s> ifname=%s marked as "
1832                                     "CONFIGURED.", __func__,
1833                                     ifi->ifi_ifname);
1834                         } else {
1835                                 /*
1836                                  * TRANSITIVE -> UNCONFIGURED
1837                                  *
1838                                  * If ifi_rainfo points to NULL, this
1839                                  * interface is shutting down.
1840                                  *
1841                                  */
1842                                 int error;
1843
1844                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1845                                 syslog(LOG_DEBUG,
1846                                     "<%s> ifname=%s marked as "
1847                                     "UNCONFIGURED.", __func__,
1848                                     ifi->ifi_ifname);
1849                                 error = sock_mc_leave(&sock,
1850                                     ifi->ifi_ifindex);
1851                                 if (error)
1852                                         exit(1);
1853                         }
1854                 }
1855                 break;
1856         }
1857 }
1858
1859 /* process RA timer */
1860 struct rtadvd_timer *
1861 ra_timeout(void *arg)
1862 {
1863         struct ifinfo *ifi;
1864
1865         ifi = (struct ifinfo *)arg;
1866         syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1867             __func__, ifi->ifi_ifname);
1868
1869         ra_output(ifi);
1870
1871         return (ifi->ifi_ra_timer);
1872 }
1873
1874 /* update RA timer */
1875 void
1876 ra_timer_update(void *arg, struct timespec *tm)
1877 {
1878         uint16_t interval;
1879         struct rainfo *rai;
1880         struct ifinfo *ifi;
1881
1882         ifi = (struct ifinfo *)arg;
1883         rai = ifi->ifi_rainfo;
1884         interval = 0;
1885
1886         switch (ifi->ifi_state) {
1887         case IFI_STATE_UNCONFIGURED:
1888                 return;
1889                 break;
1890         case IFI_STATE_CONFIGURED:
1891                 /*
1892                  * Whenever a multicast advertisement is sent from
1893                  * an interface, the timer is reset to a
1894                  * uniformly-distributed random value between the
1895                  * interface's configured MinRtrAdvInterval and
1896                  * MaxRtrAdvInterval (RFC4861 6.2.4).
1897                  */
1898                 interval = rai->rai_mininterval;
1899                 interval += arc4random_uniform(rai->rai_maxinterval -
1900                     rai->rai_mininterval);
1901                 break;
1902         case IFI_STATE_TRANSITIVE:
1903                 /*
1904                  * For the first few advertisements (up to
1905                  * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1906                  * interval is greater than
1907                  * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1908                  * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.  (RFC
1909                  * 4861 6.2.4)
1910                  *
1911                  * In such cases, the router SHOULD transmit one or more
1912                  * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1913                  * multicast Router Advertisements on the interface with a
1914                  * Router Lifetime field of zero.  (RFC 4861 6.2.5)
1915                  */
1916                 interval = ifi->ifi_burstinterval;
1917                 break;
1918         }
1919
1920         tm->tv_sec = interval;
1921         tm->tv_nsec = 0;
1922
1923         syslog(LOG_DEBUG,
1924             "<%s> RA timer on %s is set to %ld:%ld",
1925             __func__, ifi->ifi_ifname,
1926             (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1927
1928         return;
1929 }