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  * 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 witn 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                                 /* Inital 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 }