usr.sbin/rtadvd/rtadvd.c

   1 /*      $FreeBSD: stable/10/usr.sbin/rtadvd/rtadvd.c 275038 2014-11-25 13:12:45Z dim $  */
   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/queue.h>
  39 #include <sys/stat.h>
  40 #include <sys/sysctl.h>
  41
  42 #include <net/if.h>
  43 #include <net/if_types.h>
  44 #include <net/if_media.h>
  45 #include <net/if_dl.h>
  46 #include <net/route.h>
  47 #include <netinet/in.h>
  48 #include <netinet/ip6.h>
  49 #include <netinet6/ip6_var.h>
  50 #include <netinet/icmp6.h>
  51
  52 #include <arpa/inet.h>
  53
  54 #include <net/if_var.h>
  55 #include <netinet/in_var.h>
  56 #include <netinet6/nd6.h>
  57
  58 #include <time.h>
  59 #include <unistd.h>
  60 #include <stdio.h>
  61 #include <err.h>
  62 #include <errno.h>
  63 #include <inttypes.h>
  64 #include <libutil.h>
  65 #include <netdb.h>
  66 #include <signal.h>
  67 #include <string.h>
  68 #include <stdlib.h>
  69 #include <syslog.h>
  70 #include <poll.h>
  71
  72 #include "pathnames.h"
  73 #include "rtadvd.h"
  74 #include "if.h"
  75 #include "rrenum.h"
  76 #include "advcap.h"
  77 #include "timer_subr.h"
  78 #include "timer.h"
  79 #include "config.h"
  80 #include "control.h"
  81 #include "control_server.h"
  82
  83 #define RTADV_TYPE2BITMASK(type) (0x1 << type)
  84
  85 struct msghdr rcvmhdr;
  86 static char *rcvcmsgbuf;
  87 static size_t rcvcmsgbuflen;
  88 static char *sndcmsgbuf = NULL;
  89 static size_t sndcmsgbuflen;
  90 struct msghdr sndmhdr;
  91 struct iovec rcviov[2];
  92 struct iovec sndiov[2];
  93 struct sockaddr_in6 rcvfrom;
  94 static const char *pidfilename = _PATH_RTADVDPID;
  95 const char *conffile = _PATH_RTADVDCONF;
  96 static struct pidfh *pfh;
  97 static int dflag, sflag;
  98 static int wait_shutdown;
  99
 100 #define PFD_RAWSOCK     0
 101 #define PFD_RTSOCK      1
 102 #define PFD_CSOCK       2
 103 #define PFD_MAX         3
 104
 105 struct railist_head_t railist =
 106     TAILQ_HEAD_INITIALIZER(railist);
 107 struct ifilist_head_t ifilist =
 108     TAILQ_HEAD_INITIALIZER(ifilist);
 109
 110 struct nd_optlist {
 111         TAILQ_ENTRY(nd_optlist) nol_next;
 112         struct nd_opt_hdr *nol_opt;
 113 };
 114 union nd_opt {
 115         struct nd_opt_hdr *opt_array[9];
 116         struct {
 117                 struct nd_opt_hdr *zero;
 118                 struct nd_opt_hdr *src_lladdr;
 119                 struct nd_opt_hdr *tgt_lladdr;
 120                 struct nd_opt_prefix_info *pi;
 121                 struct nd_opt_rd_hdr *rh;
 122                 struct nd_opt_mtu *mtu;
 123                 TAILQ_HEAD(, nd_optlist) opt_list;
 124         } nd_opt_each;
 125 };
 126 #define opt_src_lladdr  nd_opt_each.src_lladdr
 127 #define opt_tgt_lladdr  nd_opt_each.tgt_lladdr
 128 #define opt_pi          nd_opt_each.pi
 129 #define opt_rh          nd_opt_each.rh
 130 #define opt_mtu         nd_opt_each.mtu
 131 #define opt_list        nd_opt_each.opt_list
 132
 133 #define NDOPT_FLAG_SRCLINKADDR  (1 << 0)
 134 #define NDOPT_FLAG_TGTLINKADDR  (1 << 1)
 135 #define NDOPT_FLAG_PREFIXINFO   (1 << 2)
 136 #define NDOPT_FLAG_RDHDR        (1 << 3)
 137 #define NDOPT_FLAG_MTU          (1 << 4)
 138 #define NDOPT_FLAG_RDNSS        (1 << 5)
 139 #define NDOPT_FLAG_DNSSL        (1 << 6)
 140
 141 static uint32_t ndopt_flags[] = {
 142         [ND_OPT_SOURCE_LINKADDR]        = NDOPT_FLAG_SRCLINKADDR,
 143         [ND_OPT_TARGET_LINKADDR]        = NDOPT_FLAG_TGTLINKADDR,
 144         [ND_OPT_PREFIX_INFORMATION]     = NDOPT_FLAG_PREFIXINFO,
 145         [ND_OPT_REDIRECTED_HEADER]      = NDOPT_FLAG_RDHDR,
 146         [ND_OPT_MTU]                    = NDOPT_FLAG_MTU,
 147         [ND_OPT_RDNSS]                  = NDOPT_FLAG_RDNSS,
 148         [ND_OPT_DNSSL]                  = NDOPT_FLAG_DNSSL,
 149 };
 150
 151 static void     rtadvd_shutdown(void);
 152 static void     sock_open(struct sockinfo *);
 153 static void     rtsock_open(struct sockinfo *);
 154 static void     rtadvd_input(struct sockinfo *);
 155 static void     rs_input(int, struct nd_router_solicit *,
 156                     struct in6_pktinfo *, struct sockaddr_in6 *);
 157 static void     ra_input(int, struct nd_router_advert *,
 158                     struct in6_pktinfo *, struct sockaddr_in6 *);
 159 static int      prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
 160                     struct sockaddr_in6 *);
 161 static int      nd6_options(struct nd_opt_hdr *, int,
 162                     union nd_opt *, uint32_t);
 163 static void     free_ndopts(union nd_opt *);
 164 static void     rtmsg_input(struct sockinfo *);
 165 static void     set_short_delay(struct ifinfo *);
 166 static int      check_accept_rtadv(int);
 167
 168 static void
 169 usage(void)
 170 {
 171
 172         fprintf(stderr, "usage: rtadvd [-dDfRs] "
 173             "[-c configfile] [-C ctlsock] [-M ifname] [-p pidfile]\n");
 174         exit(1);
 175 }
 176
 177 int
 178 main(int argc, char *argv[])
 179 {
 180         struct pollfd set[PFD_MAX];
 181         struct timespec *timeout;
 182         int i, ch;
 183         int fflag = 0, logopt;
 184         int error;
 185         pid_t otherpid;
 186
 187         /* get command line options and arguments */
 188         while ((ch = getopt(argc, argv, "c:C:dDfhM:p:Rs")) != -1) {
 189                 switch (ch) {
 190                 case 'c':
 191                         conffile = optarg;
 192                         break;
 193                 case 'C':
 194                         ctrlsock.si_name = optarg;
 195                         break;
 196                 case 'd':
 197                         dflag++;
 198                         break;
 199                 case 'D':
 200                         dflag += 3;
 201                         break;
 202                 case 'f':
 203                         fflag = 1;
 204                         break;
 205                 case 'M':
 206                         mcastif = optarg;
 207                         break;
 208                 case 'R':
 209                         fprintf(stderr, "rtadvd: "
 210                                 "the -R option is currently ignored.\n");
 211                         /* accept_rr = 1; */
 212                         /* run anyway... */
 213                         break;
 214                 case 's':
 215                         sflag = 1;
 216                         break;
 217                 case 'p':
 218                         pidfilename = optarg;
 219                         break;
 220                 default:
 221                         usage();
 222                 }
 223         }
 224         argc -= optind;
 225         argv += optind;
 226
 227         logopt = LOG_NDELAY | LOG_PID;
 228         if (fflag)
 229                 logopt |= LOG_PERROR;
 230         openlog("rtadvd", logopt, LOG_DAEMON);
 231
 232         /* set log level */
 233         if (dflag > 2)
 234                 (void)setlogmask(LOG_UPTO(LOG_DEBUG));
 235         else if (dflag > 1)
 236                 (void)setlogmask(LOG_UPTO(LOG_INFO));
 237         else if (dflag > 0)
 238                 (void)setlogmask(LOG_UPTO(LOG_NOTICE));
 239         else
 240                 (void)setlogmask(LOG_UPTO(LOG_ERR));
 241
 242         /* timer initialization */
 243         rtadvd_timer_init();
 244
 245 #ifndef HAVE_ARC4RANDOM
 246         /* random value initialization */
 247         srandomdev();
 248 #endif
 249         pfh = pidfile_open(pidfilename, 0600, &otherpid);
 250         if (pfh == NULL) {
 251                 if (errno == EEXIST)
 252                         errx(1, "%s already running, pid: %d",
 253                             getprogname(), otherpid);
 254                 syslog(LOG_ERR,
 255                     "failed to open the pid file %s, run anyway.",
 256                     pidfilename);
 257         }
 258         if (!fflag)
 259                 daemon(1, 0);
 260
 261         sock_open(&sock);
 262
 263         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 264         for (i = 0; i < argc; i++)
 265                 update_persist_ifinfo(&ifilist, argv[i]);
 266
 267         csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 268         if (ctrlsock.si_fd == -1) {
 269                 syslog(LOG_ERR, "cannot open control socket: %s",
 270                     strerror(errno));
 271                 exit(1);
 272         }
 273
 274         /* record the current PID */
 275         pidfile_write(pfh);
 276
 277         set[PFD_RAWSOCK].fd = sock.si_fd;
 278         set[PFD_RAWSOCK].events = POLLIN;
 279         if (sflag == 0) {
 280                 rtsock_open(&rtsock);
 281                 set[PFD_RTSOCK].fd = rtsock.si_fd;
 282                 set[PFD_RTSOCK].events = POLLIN;
 283         } else
 284                 set[PFD_RTSOCK].fd = -1;
 285         set[PFD_CSOCK].fd = ctrlsock.si_fd;
 286         set[PFD_CSOCK].events = POLLIN;
 287         signal(SIGTERM, set_do_shutdown);
 288         signal(SIGINT, set_do_shutdown);
 289         signal(SIGHUP, set_do_reload);
 290
 291         error = csock_listen(&ctrlsock);
 292         if (error) {
 293                 syslog(LOG_ERR, "cannot listen control socket: %s",
 294                     strerror(errno));
 295                 exit(1);
 296         }
 297
 298         /* load configuration file */
 299         set_do_reload(0);
 300
 301         while (1) {
 302                 if (is_do_shutdown())
 303                         rtadvd_shutdown();
 304
 305                 if (is_do_reload()) {
 306                         loadconfig_ifname(reload_ifname());
 307                         if (reload_ifname() == NULL)
 308                                 syslog(LOG_INFO,
 309                                     "configuration file reloaded.");
 310                         else
 311                                 syslog(LOG_INFO,
 312                                     "configuration file for %s reloaded.",
 313                                     reload_ifname());
 314                         reset_do_reload();
 315                 }
 316
 317                 /* timeout handler update for active interfaces */
 318                 rtadvd_update_timeout_handler();
 319
 320                 /* timer expiration check and reset the timer */
 321                 timeout = rtadvd_check_timer();
 322
 323                 if (timeout != NULL) {
 324                         syslog(LOG_DEBUG,
 325                             "<%s> set timer to %ld:%ld. waiting for "
 326                             "inputs or timeout", __func__,
 327                             (long int)timeout->tv_sec,
 328                             (long int)timeout->tv_nsec / 1000);
 329                 } else {
 330                         syslog(LOG_DEBUG,
 331                             "<%s> there's no timer. waiting for inputs",
 332                             __func__);
 333                 }
 334                 if ((i = poll(set, NELEM(set),
 335                               timeout ? (timeout->tv_sec * 1000 +
 336                                          timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
 337
 338                         /* EINTR would occur if a signal was delivered */
 339                         if (errno != EINTR)
 340                                 syslog(LOG_ERR, "poll() failed: %s",
 341                                     strerror(errno));
 342                         continue;
 343                 }
 344                 if (i == 0)     /* timeout */
 345                         continue;
 346                 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
 347                         rtmsg_input(&rtsock);
 348
 349                 if (set[PFD_RAWSOCK].revents & POLLIN)
 350                         rtadvd_input(&sock);
 351
 352                 if (set[PFD_CSOCK].revents & POLLIN) {
 353                         int fd;
 354
 355                         fd = csock_accept(&ctrlsock);
 356                         if (fd == -1)
 357                                 syslog(LOG_ERR,
 358                                     "cannot accept() control socket: %s",
 359                                     strerror(errno));
 360                         else {
 361                                 cm_handler_server(fd);
 362                                 close(fd);
 363                         }
 364                 }
 365         }
 366         exit(0);                /* NOTREACHED */
 367 }
 368
 369 static void
 370 rtadvd_shutdown(void)
 371 {
 372         struct ifinfo *ifi;
 373         struct rainfo *rai;
 374         struct rdnss *rdn;
 375         struct dnssl *dns;
 376
 377         if (wait_shutdown) {
 378                 syslog(LOG_INFO,
 379                     "waiting expiration of the all RA timers.");
 380
 381                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 382                         /*
 383                          * Ignore !IFF_UP interfaces in waiting for shutdown.
 384                          */
 385                         if (!(ifi->ifi_flags & IFF_UP) &&
 386                             ifi->ifi_ra_timer != NULL) {
 387                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 388                                 rtadvd_remove_timer(ifi->ifi_ra_timer);
 389                                 ifi->ifi_ra_timer = NULL;
 390                                 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
 391                                     "Timer removed and marked as UNCONFIGURED.",
 392                                      __func__, ifi->ifi_ifname,
 393                                     ifi->ifi_ifindex);
 394                         }
 395                 }
 396                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 397                         if (ifi->ifi_ra_timer != NULL)
 398                                 break;
 399                 }
 400                 if (ifi == NULL) {
 401                         syslog(LOG_NOTICE, "gracefully terminated.");
 402                         exit(0);
 403                 }
 404
 405                 sleep(1);
 406                 return;
 407         }
 408
 409         syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
 410             __func__);
 411
 412         wait_shutdown = 1;
 413
 414         TAILQ_FOREACH(rai, &railist, rai_next) {
 415                 rai->rai_lifetime = 0;
 416                 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
 417                         rdn->rd_ltime = 0;
 418                 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
 419                         dns->dn_ltime = 0;
 420         }
 421         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 422                 if (!ifi->ifi_persist)
 423                         continue;
 424                 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
 425                         continue;
 426                 if (ifi->ifi_ra_timer == NULL)
 427                         continue;
 428                 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
 429                     ifi->ifi_ra_lastsent.tv_nsec == 0 &&
 430                     ifi->ifi_ra_timer != NULL) {
 431                         /*
 432                          * When RA configured but never sent,
 433                          * ignore the IF immediately.
 434                          */
 435                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 436                         ifi->ifi_ra_timer = NULL;
 437                         ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 438                         continue;
 439                 }
 440
 441                 ifi->ifi_state = IFI_STATE_TRANSITIVE;
 442
 443                 /* Mark as the shut-down state. */
 444                 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
 445                 ifi->ifi_rainfo = NULL;
 446
 447                 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
 448                 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
 449
 450                 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 451                 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 452                     ifi->ifi_ra_timer);
 453         }
 454         syslog(LOG_NOTICE, "final RA transmission started.");
 455
 456         pidfile_remove(pfh);
 457         csock_close(&ctrlsock);
 458 }
 459
 460 static void
 461 rtmsg_input(struct sockinfo *s)
 462 {
 463         int n, type, ifindex = 0, plen;
 464         size_t len;
 465         char msg[2048], *next, *lim;
 466         char ifname[IFNAMSIZ];
 467         struct if_announcemsghdr *ifan;
 468         struct rt_msghdr *rtm;
 469         struct prefix *pfx;
 470         struct rainfo *rai;
 471         struct in6_addr *addr;
 472         struct ifinfo *ifi;
 473         char addrbuf[INET6_ADDRSTRLEN];
 474         int prefixchange = 0;
 475
 476         if (s == NULL) {
 477                 syslog(LOG_ERR, "<%s> internal error", __func__);
 478                 exit(1);
 479         }
 480         n = read(s->si_fd, msg, sizeof(msg));
 481         rtm = (struct rt_msghdr *)msg;
 482         syslog(LOG_DEBUG, "<%s> received a routing message "
 483             "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
 484
 485         if (n > rtm->rtm_msglen) {
 486                 /*
 487                  * This usually won't happen for messages received on
 488                  * a routing socket.
 489                  */
 490                 syslog(LOG_DEBUG,
 491                     "<%s> received data length is larger than "
 492                     "1st routing message len. multiple messages? "
 493                     "read %d bytes, but 1st msg len = %d",
 494                     __func__, n, rtm->rtm_msglen);
 495 #if 0
 496                 /* adjust length */
 497                 n = rtm->rtm_msglen;
 498 #endif
 499         }
 500
 501         lim = msg + n;
 502         for (next = msg; next < lim; next += len) {
 503                 int oldifflags;
 504
 505                 next = get_next_msg(next, lim, 0, &len,
 506                     RTADV_TYPE2BITMASK(RTM_ADD) |
 507                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 508                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 509                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 510                     RTADV_TYPE2BITMASK(RTM_IFINFO) |
 511                     RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
 512                 if (len == 0)
 513                         break;
 514                 type = ((struct rt_msghdr *)next)->rtm_type;
 515                 switch (type) {
 516                 case RTM_ADD:
 517                 case RTM_DELETE:
 518                         ifindex = get_rtm_ifindex(next);
 519                         break;
 520                 case RTM_NEWADDR:
 521                 case RTM_DELADDR:
 522                         ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
 523                         break;
 524                 case RTM_IFINFO:
 525                         ifindex = (int)((struct if_msghdr *)next)->ifm_index;
 526                         break;
 527                 case RTM_IFANNOUNCE:
 528                         ifan = (struct if_announcemsghdr *)next;
 529                         switch (ifan->ifan_what) {
 530                         case IFAN_ARRIVAL:
 531                         case IFAN_DEPARTURE:
 532                                 break;
 533                         default:
 534                                 syslog(LOG_DEBUG,
 535                                     "<%s:%d> unknown ifan msg (ifan_what=%d)",
 536                                    __func__, __LINE__, ifan->ifan_what);
 537                                 continue;
 538                         }
 539
 540                         syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
 541                                __func__, ifan->ifan_index, ifan->ifan_what);
 542                         switch (ifan->ifan_what) {
 543                         case IFAN_ARRIVAL:
 544                                 syslog(LOG_NOTICE,
 545                                     "interface added (idx=%d)",
 546                                     ifan->ifan_index);
 547                                 update_ifinfo(&ifilist, ifan->ifan_index);
 548                                 loadconfig_index(ifan->ifan_index);
 549                                 break;
 550                         case IFAN_DEPARTURE:
 551                                 syslog(LOG_NOTICE,
 552                                     "interface removed (idx=%d)",
 553                                     ifan->ifan_index);
 554                                 rm_ifinfo_index(ifan->ifan_index);
 555
 556                                 /* Clear ifi_ifindex */
 557                                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 558                                         if (ifi->ifi_ifindex
 559                                             == ifan->ifan_index) {
 560                                                 ifi->ifi_ifindex = 0;
 561                                                 break;
 562                                         }
 563                                 }
 564                                 update_ifinfo(&ifilist, ifan->ifan_index);
 565                                 break;
 566                         }
 567                         continue;
 568                 default:
 569                         /* should not reach here */
 570                         syslog(LOG_DEBUG,
 571                                "<%s:%d> unknown rtmsg %d on %s",
 572                                __func__, __LINE__, type,
 573                                if_indextoname(ifindex, ifname));
 574                         continue;
 575                 }
 576                 ifi = if_indextoifinfo(ifindex);
 577                 if (ifi == NULL) {
 578                         syslog(LOG_DEBUG,
 579                             "<%s> ifinfo not found for idx=%d.  Why?",
 580                             __func__, ifindex);
 581                         continue;
 582                 }
 583                 rai = ifi->ifi_rainfo;
 584                 if (rai == NULL) {
 585                         syslog(LOG_DEBUG,
 586                             "<%s> route changed on "
 587                             "non advertising interface(%s)",
 588                             __func__, ifi->ifi_ifname);
 589                         continue;
 590                 }
 591
 592                 oldifflags = ifi->ifi_flags;
 593                 /* init ifflags because it may have changed */
 594                 update_ifinfo(&ifilist, ifindex);
 595
 596                 switch (type) {
 597                 case RTM_ADD:
 598                         if (sflag)
 599                                 break;  /* we aren't interested in prefixes  */
 600
 601                         addr = get_addr(msg);
 602                         plen = get_prefixlen(msg);
 603                         /* sanity check for plen */
 604                         /* as RFC2373, prefixlen is at least 4 */
 605                         if (plen < 4 || plen > 127) {
 606                                 syslog(LOG_INFO, "<%s> new interface route's"
 607                                     "plen %d is invalid for a prefix",
 608                                     __func__, plen);
 609                                 break;
 610                         }
 611                         pfx = find_prefix(rai, addr, plen);
 612                         if (pfx) {
 613                                 if (pfx->pfx_timer) {
 614                                         /*
 615                                          * If the prefix has been invalidated,
 616                                          * make it available again.
 617                                          */
 618                                         update_prefix(pfx);
 619                                         prefixchange = 1;
 620                                 } else
 621                                         syslog(LOG_DEBUG,
 622                                             "<%s> new prefix(%s/%d) "
 623                                             "added on %s, "
 624                                             "but it was already in list",
 625                                             __func__,
 626                                             inet_ntop(AF_INET6, addr,
 627                                                 (char *)addrbuf,
 628                                                 sizeof(addrbuf)),
 629                                             plen, ifi->ifi_ifname);
 630                                 break;
 631                         }
 632                         make_prefix(rai, ifindex, addr, plen);
 633                         prefixchange = 1;
 634                         break;
 635                 case RTM_DELETE:
 636                         if (sflag)
 637                                 break;
 638
 639                         addr = get_addr(msg);
 640                         plen = get_prefixlen(msg);
 641                         /* sanity check for plen */
 642                         /* as RFC2373, prefixlen is at least 4 */
 643                         if (plen < 4 || plen > 127) {
 644                                 syslog(LOG_INFO,
 645                                     "<%s> deleted interface route's "
 646                                     "plen %d is invalid for a prefix",
 647                                     __func__, plen);
 648                                 break;
 649                         }
 650                         pfx = find_prefix(rai, addr, plen);
 651                         if (pfx == NULL) {
 652                                 syslog(LOG_DEBUG,
 653                                     "<%s> prefix(%s/%d) was deleted on %s, "
 654                                     "but it was not in list",
 655                                     __func__, inet_ntop(AF_INET6, addr,
 656                                         (char *)addrbuf, sizeof(addrbuf)),
 657                                         plen, ifi->ifi_ifname);
 658                                 break;
 659                         }
 660                         invalidate_prefix(pfx);
 661                         prefixchange = 1;
 662                         break;
 663                 case RTM_NEWADDR:
 664                 case RTM_DELADDR:
 665                 case RTM_IFINFO:
 666                         break;
 667                 default:
 668                         /* should not reach here */
 669                         syslog(LOG_DEBUG,
 670                             "<%s:%d> unknown rtmsg %d on %s",
 671                             __func__, __LINE__, type,
 672                             if_indextoname(ifindex, ifname));
 673                         return;
 674                 }
 675
 676                 /* check if an interface flag is changed */
 677                 if ((oldifflags & IFF_UP) && /* UP to DOWN */
 678                     !(ifi->ifi_flags & IFF_UP)) {
 679                         syslog(LOG_NOTICE,
 680                             "<interface %s becomes down. stop timer.",
 681                             ifi->ifi_ifname);
 682                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 683                         ifi->ifi_ra_timer = NULL;
 684                 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
 685                     (ifi->ifi_flags & IFF_UP)) {
 686                         syslog(LOG_NOTICE,
 687                             "interface %s becomes up. restart timer.",
 688                             ifi->ifi_ifname);
 689
 690                         ifi->ifi_state = IFI_STATE_TRANSITIVE;
 691                         ifi->ifi_burstcount =
 692                             MAX_INITIAL_RTR_ADVERTISEMENTS;
 693                         ifi->ifi_burstinterval =
 694                             MAX_INITIAL_RTR_ADVERT_INTERVAL;
 695
 696                         ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
 697                             ra_timer_update, ifi, ifi);
 698                         ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 699                         rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 700                             ifi->ifi_ra_timer);
 701                 } else if (prefixchange &&
 702                     (ifi->ifi_flags & IFF_UP)) {
 703                         /*
 704                          * An advertised prefix has been added or invalidated.
 705                          * Will notice the change in a short delay.
 706                          */
 707                         set_short_delay(ifi);
 708                 }
 709         }
 710
 711         return;
 712 }
 713
 714 void
 715 rtadvd_input(struct sockinfo *s)
 716 {
 717         ssize_t i;
 718         int *hlimp = NULL;
 719 #ifdef OLDRAWSOCKET
 720         struct ip6_hdr *ip;
 721 #endif
 722         struct icmp6_hdr *icp;
 723         int ifindex = 0;
 724         struct cmsghdr *cm;
 725         struct in6_pktinfo *pi = NULL;
 726         char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 727         struct in6_addr dst = in6addr_any;
 728         struct ifinfo *ifi;
 729
 730         syslog(LOG_DEBUG, "<%s> enter", __func__);
 731
 732         if (s == NULL) {
 733                 syslog(LOG_ERR, "<%s> internal error", __func__);
 734                 exit(1);
 735         }
 736         /*
 737          * Get message. We reset msg_controllen since the field could
 738          * be modified if we had received a message before setting
 739          * receive options.
 740          */
 741         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 742         if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
 743                 return;
 744
 745         /* extract optional information via Advanced API */
 746         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 747              cm;
 748              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 749                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 750                     cm->cmsg_type == IPV6_PKTINFO &&
 751                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 752                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 753                         ifindex = pi->ipi6_ifindex;
 754                         dst = pi->ipi6_addr;
 755                 }
 756                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 757                     cm->cmsg_type == IPV6_HOPLIMIT &&
 758                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 759                         hlimp = (int *)CMSG_DATA(cm);
 760         }
 761         if (ifindex == 0) {
 762                 syslog(LOG_ERR, "failed to get receiving interface");
 763                 return;
 764         }
 765         if (hlimp == NULL) {
 766                 syslog(LOG_ERR, "failed to get receiving hop limit");
 767                 return;
 768         }
 769
 770         /*
 771          * If we happen to receive data on an interface which is now gone
 772          * or down, just discard the data.
 773          */
 774         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 775         if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
 776                 syslog(LOG_INFO,
 777                     "<%s> received data on a disabled interface (%s)",
 778                     __func__,
 779                     (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
 780                 return;
 781         }
 782
 783 #ifdef OLDRAWSOCKET
 784         if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 785                 syslog(LOG_ERR,
 786                     "packet size(%d) is too short", i);
 787                 return;
 788         }
 789
 790         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 791         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 792 #else
 793         if ((size_t)i < sizeof(struct icmp6_hdr)) {
 794                 syslog(LOG_ERR, "packet size(%zd) is too short", i);
 795                 return;
 796         }
 797
 798         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 799 #endif
 800
 801         switch (icp->icmp6_type) {
 802         case ND_ROUTER_SOLICIT:
 803                 /*
 804                  * Message verification - RFC 4861 6.1.1
 805                  * XXX: these checks must be done in the kernel as well,
 806                  *      but we can't completely rely on them.
 807                  */
 808                 if (*hlimp != 255) {
 809                         syslog(LOG_NOTICE,
 810                             "RS with invalid hop limit(%d) "
 811                             "received from %s on %s",
 812                             *hlimp,
 813                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 814                             sizeof(ntopbuf)),
 815                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 816                         return;
 817                 }
 818                 if (icp->icmp6_code) {
 819                         syslog(LOG_NOTICE,
 820                             "RS with invalid ICMP6 code(%d) "
 821                             "received from %s on %s",
 822                             icp->icmp6_code,
 823                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 824                             sizeof(ntopbuf)),
 825                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 826                         return;
 827                 }
 828                 if ((size_t)i < sizeof(struct nd_router_solicit)) {
 829                         syslog(LOG_NOTICE,
 830                             "RS from %s on %s does not have enough "
 831                             "length (len = %zd)",
 832                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 833                             sizeof(ntopbuf)),
 834                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 835                         return;
 836                 }
 837                 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
 838                 break;
 839         case ND_ROUTER_ADVERT:
 840                 /*
 841                  * Message verification - RFC 4861 6.1.2
 842                  * XXX: there's the same dilemma as above...
 843                  */
 844                 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
 845                         syslog(LOG_NOTICE,
 846                             "RA with non-linklocal source address "
 847                             "received from %s on %s",
 848                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
 849                             ntopbuf, sizeof(ntopbuf)),
 850                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 851                         return;
 852                 }
 853                 if (*hlimp != 255) {
 854                         syslog(LOG_NOTICE,
 855                             "RA with invalid hop limit(%d) "
 856                             "received from %s on %s",
 857                             *hlimp,
 858                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 859                             sizeof(ntopbuf)),
 860                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 861                         return;
 862                 }
 863                 if (icp->icmp6_code) {
 864                         syslog(LOG_NOTICE,
 865                             "RA with invalid ICMP6 code(%d) "
 866                             "received from %s on %s",
 867                             icp->icmp6_code,
 868                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 869                             sizeof(ntopbuf)),
 870                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 871                         return;
 872                 }
 873                 if ((size_t)i < sizeof(struct nd_router_advert)) {
 874                         syslog(LOG_NOTICE,
 875                             "RA from %s on %s does not have enough "
 876                             "length (len = %zd)",
 877                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 878                             sizeof(ntopbuf)),
 879                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 880                         return;
 881                 }
 882                 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
 883                 break;
 884         case ICMP6_ROUTER_RENUMBERING:
 885                 if (mcastif == NULL) {
 886                         syslog(LOG_ERR, "received a router renumbering "
 887                             "message, but not allowed to be accepted");
 888                         break;
 889                 }
 890                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
 891                     &dst);
 892                 break;
 893         default:
 894                 /*
 895                  * Note that this case is POSSIBLE, especially just
 896                  * after invocation of the daemon. This is because we
 897                  * could receive message after opening the socket and
 898                  * before setting ICMP6 type filter(see sock_open()).
 899                  */
 900                 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
 901                 return;
 902         }
 903
 904         return;
 905 }
 906
 907 static void
 908 rs_input(int len, struct nd_router_solicit *rs,
 909          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 910 {
 911         char ntopbuf[INET6_ADDRSTRLEN];
 912         char ifnamebuf[IFNAMSIZ];
 913         union nd_opt ndopts;
 914         struct rainfo *rai;
 915         struct ifinfo *ifi;
 916         struct soliciter *sol;
 917
 918         syslog(LOG_DEBUG,
 919             "<%s> RS received from %s on %s",
 920             __func__,
 921             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
 922             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 923
 924         /* ND option check */
 925         memset(&ndopts, 0, sizeof(ndopts));
 926         TAILQ_INIT(&ndopts.opt_list);
 927         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 928                         len - sizeof(struct nd_router_solicit),
 929                         &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 930                 syslog(LOG_INFO,
 931                     "<%s> ND option check failed for an RS from %s on %s",
 932                     __func__,
 933                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
 934                         sizeof(ntopbuf)),
 935                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 936                 return;
 937         }
 938
 939         /*
 940          * If the IP source address is the unspecified address, there
 941          * must be no source link-layer address option in the message.
 942          * (RFC 4861 6.1.1)
 943          */
 944         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 945             ndopts.opt_src_lladdr) {
 946                 syslog(LOG_INFO,
 947                     "<%s> RS from unspecified src on %s has a link-layer"
 948                     " address option",
 949                     __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 950                 goto done;
 951         }
 952
 953         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 954         if (ifi == NULL) {
 955                 syslog(LOG_INFO,
 956                     "<%s> if (idx=%d) not found.  Why?",
 957                     __func__, pi->ipi6_ifindex);
 958                 goto done;
 959         }
 960         rai = ifi->ifi_rainfo;
 961         if (rai == NULL) {
 962                 syslog(LOG_INFO,
 963                        "<%s> RS received on non advertising interface(%s)",
 964                        __func__,
 965                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 966                 goto done;
 967         }
 968
 969         rai->rai_ifinfo->ifi_rsinput++;
 970
 971         /*
 972          * Decide whether to send RA according to the rate-limit
 973          * consideration.
 974          */
 975
 976         /* record sockaddr waiting for RA, if possible */
 977         sol = (struct soliciter *)malloc(sizeof(*sol));
 978         if (sol) {
 979                 sol->sol_addr = *from;
 980                 /* XXX RFC 2553 need clarification on flowinfo */
 981                 sol->sol_addr.sin6_flowinfo = 0;
 982                 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
 983         }
 984
 985         /*
 986          * If there is already a waiting RS packet, don't
 987          * update the timer.
 988          */
 989         if (ifi->ifi_rs_waitcount++)
 990                 goto done;
 991
 992         set_short_delay(ifi);
 993
 994   done:
 995         free_ndopts(&ndopts);
 996         return;
 997 }
 998
 999 static void
1000 set_short_delay(struct ifinfo *ifi)
1001 {
1002         long delay;     /* must not be greater than 1000000 */
1003         struct timespec interval, now, min_delay, tm_tmp, *rest;
1004
1005         if (ifi->ifi_ra_timer == NULL)
1006                 return;
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_nsec = delay * 1000;
1021         rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1022         if (TS_CMP(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         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1036         TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1037         min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1038         min_delay.tv_nsec = 0;
1039         if (TS_CMP(&tm_tmp, &min_delay, <)) {
1040                 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1041                 TS_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         /*
1062          * RA_RECV: ND6_IFF_ACCEPT_RTADV
1063          * RA_SEND: ip6.forwarding
1064          */
1065         if (update_ifinfo_nd_flags(ifi) != 0) {
1066                 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1067                 return (0);
1068         }
1069
1070         return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1071 }
1072
1073 static void
1074 ra_input(int len, struct nd_router_advert *nra,
1075          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1076 {
1077         struct rainfo *rai;
1078         struct ifinfo *ifi;
1079         char ntopbuf[INET6_ADDRSTRLEN];
1080         char ifnamebuf[IFNAMSIZ];
1081         union nd_opt ndopts;
1082         const char *on_off[] = {"OFF", "ON"};
1083         uint32_t reachabletime, retranstimer, mtu;
1084         int inconsistent = 0;
1085         int error;
1086
1087         syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1088             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1089             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1090
1091         /* ND option check */
1092         memset(&ndopts, 0, sizeof(ndopts));
1093         TAILQ_INIT(&ndopts.opt_list);
1094         error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1095             len - sizeof(struct nd_router_advert), &ndopts,
1096             NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1097             NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1098         if (error) {
1099                 syslog(LOG_INFO,
1100                     "<%s> ND option check failed for an RA from %s on %s",
1101                     __func__,
1102                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1103                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1104                         ifnamebuf));
1105                 return;
1106         }
1107
1108         /*
1109          * RA consistency check according to RFC 4861 6.2.7
1110          */
1111         ifi = if_indextoifinfo(pi->ipi6_ifindex);
1112         if (ifi->ifi_rainfo == NULL) {
1113                 syslog(LOG_INFO,
1114                     "<%s> received RA from %s on non-advertising"
1115                     " interface(%s)",
1116                     __func__,
1117                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1118                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1119                         ifnamebuf));
1120                 goto done;
1121         }
1122         rai = ifi->ifi_rainfo;
1123         ifi->ifi_rainput++;
1124         syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1125             ifi->ifi_rainput);
1126
1127         /* Cur Hop Limit value */
1128         if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1129             nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1130                 syslog(LOG_NOTICE,
1131                     "CurHopLimit inconsistent on %s:"
1132                     " %d from %s, %d from us",
1133                     ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1134                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1135                         sizeof(ntopbuf)), rai->rai_hoplimit);
1136                 inconsistent++;
1137         }
1138         /* M flag */
1139         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1140             rai->rai_managedflg) {
1141                 syslog(LOG_NOTICE,
1142                     "M flag inconsistent on %s:"
1143                     " %s from %s, %s from us",
1144                     ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1145                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1146                         sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1147                 inconsistent++;
1148         }
1149         /* O flag */
1150         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1151             rai->rai_otherflg) {
1152                 syslog(LOG_NOTICE,
1153                     "O flag inconsistent on %s:"
1154                     " %s from %s, %s from us",
1155                     ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1156                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1157                         sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1158                 inconsistent++;
1159         }
1160         /* Reachable Time */
1161         reachabletime = ntohl(nra->nd_ra_reachable);
1162         if (reachabletime && rai->rai_reachabletime &&
1163             reachabletime != rai->rai_reachabletime) {
1164                 syslog(LOG_NOTICE,
1165                     "ReachableTime inconsistent on %s:"
1166                     " %d from %s, %d from us",
1167                     ifi->ifi_ifname, reachabletime,
1168                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1169                         sizeof(ntopbuf)), rai->rai_reachabletime);
1170                 inconsistent++;
1171         }
1172         /* Retrans Timer */
1173         retranstimer = ntohl(nra->nd_ra_retransmit);
1174         if (retranstimer && rai->rai_retranstimer &&
1175             retranstimer != rai->rai_retranstimer) {
1176                 syslog(LOG_NOTICE,
1177                     "RetranceTimer inconsistent on %s:"
1178                     " %d from %s, %d from us",
1179                     ifi->ifi_ifname, retranstimer,
1180                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1181                         sizeof(ntopbuf)), rai->rai_retranstimer);
1182                 inconsistent++;
1183         }
1184         /* Values in the MTU options */
1185         if (ndopts.opt_mtu) {
1186                 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1187                 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1188                         syslog(LOG_NOTICE,
1189                             "MTU option value inconsistent on %s:"
1190                             " %d from %s, %d from us",
1191                             ifi->ifi_ifname, mtu,
1192                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1193                                 sizeof(ntopbuf)), rai->rai_linkmtu);
1194                         inconsistent++;
1195                 }
1196         }
1197         /* Preferred and Valid Lifetimes for prefixes */
1198         {
1199                 struct nd_optlist *nol;
1200
1201                 if (ndopts.opt_pi)
1202                         if (prefix_check(ndopts.opt_pi, rai, from))
1203                                 inconsistent++;
1204
1205                 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1206                         if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1207                                 rai, from))
1208                                 inconsistent++;
1209         }
1210
1211         if (inconsistent)
1212                 ifi->ifi_rainconsistent++;
1213
1214   done:
1215         free_ndopts(&ndopts);
1216         return;
1217 }
1218
1219 static uint32_t
1220 udiff(uint32_t u, uint32_t v)
1221 {
1222         return (u >= v ? u - v : v - u);
1223 }
1224
1225 /* return a non-zero value if the received prefix is inconsitent with ours */
1226 static int
1227 prefix_check(struct nd_opt_prefix_info *pinfo,
1228         struct rainfo *rai, struct sockaddr_in6 *from)
1229 {
1230         struct ifinfo *ifi;
1231         uint32_t preferred_time, valid_time;
1232         struct prefix *pfx;
1233         int inconsistent = 0;
1234         char ntopbuf[INET6_ADDRSTRLEN];
1235         char prefixbuf[INET6_ADDRSTRLEN];
1236         struct timespec now;
1237
1238 #if 0                           /* impossible */
1239         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1240                 return (0);
1241 #endif
1242         ifi = rai->rai_ifinfo;
1243         /*
1244          * log if the adveritsed prefix has link-local scope(sanity check?)
1245          */
1246         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1247                 syslog(LOG_INFO,
1248                     "<%s> link-local prefix %s/%d is advertised "
1249                     "from %s on %s",
1250                     __func__,
1251                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1252                         sizeof(prefixbuf)),
1253                     pinfo->nd_opt_pi_prefix_len,
1254                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1255                         sizeof(ntopbuf)), ifi->ifi_ifname);
1256
1257         if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1258                 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1259                 syslog(LOG_INFO,
1260                     "<%s> prefix %s/%d from %s on %s is not in our list",
1261                     __func__,
1262                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1263                         sizeof(prefixbuf)),
1264                     pinfo->nd_opt_pi_prefix_len,
1265                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1266                         sizeof(ntopbuf)), ifi->ifi_ifname);
1267                 return (0);
1268         }
1269
1270         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1271         if (pfx->pfx_pltimeexpire) {
1272                 /*
1273                  * The lifetime is decremented in real time, so we should
1274                  * compare the expiration time.
1275                  * (RFC 2461 Section 6.2.7.)
1276                  * XXX: can we really expect that all routers on the link
1277                  * have synchronized clocks?
1278                  */
1279                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1280                 preferred_time += now.tv_sec;
1281
1282                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1283                     udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1284                         syslog(LOG_INFO,
1285                             "<%s> preferred lifetime for %s/%d"
1286                             " (decr. in real time) inconsistent on %s:"
1287                             " %" PRIu32 " from %s, %" PRIu32 " from us",
1288                             __func__,
1289                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1290                                 sizeof(prefixbuf)),
1291                             pinfo->nd_opt_pi_prefix_len,
1292                             ifi->ifi_ifname, preferred_time,
1293                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1294                                 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1295                         inconsistent++;
1296                 }
1297         } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1298                 syslog(LOG_INFO,
1299                     "<%s> preferred lifetime for %s/%d"
1300                     " inconsistent on %s:"
1301                     " %d from %s, %d from us",
1302                     __func__,
1303                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1304                         sizeof(prefixbuf)),
1305                     pinfo->nd_opt_pi_prefix_len,
1306                     ifi->ifi_ifname, preferred_time,
1307                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1308                         sizeof(ntopbuf)), pfx->pfx_preflifetime);
1309
1310         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1311         if (pfx->pfx_vltimeexpire) {
1312                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1313                 valid_time += now.tv_sec;
1314
1315                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1316                     udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1317                         syslog(LOG_INFO,
1318                             "<%s> valid lifetime for %s/%d"
1319                             " (decr. in real time) inconsistent on %s:"
1320                             " %d from %s, %" PRIu32 " from us",
1321                             __func__,
1322                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1323                                 sizeof(prefixbuf)),
1324                             pinfo->nd_opt_pi_prefix_len,
1325                             ifi->ifi_ifname, preferred_time,
1326                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1327                                 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1328                         inconsistent++;
1329                 }
1330         } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1331                 syslog(LOG_INFO,
1332                     "<%s> valid lifetime for %s/%d"
1333                     " inconsistent on %s:"
1334                     " %d from %s, %d from us",
1335                     __func__,
1336                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1337                         sizeof(prefixbuf)),
1338                     pinfo->nd_opt_pi_prefix_len,
1339                     ifi->ifi_ifname, valid_time,
1340                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1341                         sizeof(ntopbuf)), pfx->pfx_validlifetime);
1342                 inconsistent++;
1343         }
1344
1345         return (inconsistent);
1346 }
1347
1348 struct prefix *
1349 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1350 {
1351         struct prefix *pfx;
1352         int bytelen, bitlen;
1353         char bitmask;
1354
1355         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1356                 if (plen != pfx->pfx_prefixlen)
1357                         continue;
1358
1359                 bytelen = plen / 8;
1360                 bitlen = plen % 8;
1361                 bitmask = 0xff << (8 - bitlen);
1362
1363                 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1364                         continue;
1365
1366                 if (bitlen == 0 ||
1367                     ((prefix->s6_addr[bytelen] & bitmask) ==
1368                      (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1369                         return (pfx);
1370                 }
1371         }
1372
1373         return (NULL);
1374 }
1375
1376 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1377 int
1378 prefix_match(struct in6_addr *p0, int plen0,
1379         struct in6_addr *p1, int plen1)
1380 {
1381         int bytelen, bitlen;
1382         char bitmask;
1383
1384         if (plen0 < plen1)
1385                 return (0);
1386
1387         bytelen = plen1 / 8;
1388         bitlen = plen1 % 8;
1389         bitmask = 0xff << (8 - bitlen);
1390
1391         if (memcmp((void *)p0, (void *)p1, bytelen))
1392                 return (0);
1393
1394         if (bitlen == 0 ||
1395             ((p0->s6_addr[bytelen] & bitmask) ==
1396              (p1->s6_addr[bytelen] & bitmask))) {
1397                 return (1);
1398         }
1399
1400         return (0);
1401 }
1402
1403 static int
1404 nd6_options(struct nd_opt_hdr *hdr, int limit,
1405         union nd_opt *ndopts, uint32_t optflags)
1406 {
1407         int optlen = 0;
1408
1409         for (; limit > 0; limit -= optlen) {
1410                 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1411                         syslog(LOG_INFO, "<%s> short option header", __func__);
1412                         goto bad;
1413                 }
1414
1415                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1416                 if (hdr->nd_opt_len == 0) {
1417                         syslog(LOG_INFO,
1418                             "<%s> bad ND option length(0) (type = %d)",
1419                             __func__, hdr->nd_opt_type);
1420                         goto bad;
1421                 }
1422                 optlen = hdr->nd_opt_len << 3;
1423                 if (optlen > limit) {
1424                         syslog(LOG_INFO, "<%s> short option", __func__);
1425                         goto bad;
1426                 }
1427
1428                 if (hdr->nd_opt_type > ND_OPT_MTU &&
1429                     hdr->nd_opt_type != ND_OPT_RDNSS &&
1430                     hdr->nd_opt_type != ND_OPT_DNSSL) {
1431                         syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1432                             __func__, hdr->nd_opt_type);
1433                         continue;
1434                 }
1435
1436                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1437                         syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1438                             __func__, hdr->nd_opt_type);
1439                         continue;
1440                 }
1441
1442                 /*
1443                  * Option length check.  Do it here for all fixed-length
1444                  * options.
1445                  */
1446                 switch (hdr->nd_opt_type) {
1447                 case ND_OPT_MTU:
1448                         if (optlen == sizeof(struct nd_opt_mtu))
1449                                 break;
1450                         goto skip;
1451                 case ND_OPT_RDNSS:
1452                         if (optlen >= 24 &&
1453                             (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1454                                 break;
1455                         goto skip;
1456                 case ND_OPT_DNSSL:
1457                         if (optlen >= 16 &&
1458                             (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1459                                 break;
1460                         goto skip;
1461                 case ND_OPT_PREFIX_INFORMATION:
1462                         if (optlen == sizeof(struct nd_opt_prefix_info))
1463                                 break;
1464 skip:
1465                         syslog(LOG_INFO, "<%s> invalid option length",
1466                             __func__);
1467                         continue;
1468                 }
1469
1470                 switch (hdr->nd_opt_type) {
1471                 case ND_OPT_TARGET_LINKADDR:
1472                 case ND_OPT_REDIRECTED_HEADER:
1473                 case ND_OPT_RDNSS:
1474                 case ND_OPT_DNSSL:
1475                         break;  /* we don't care about these options */
1476                 case ND_OPT_SOURCE_LINKADDR:
1477                 case ND_OPT_MTU:
1478                         if (ndopts->opt_array[hdr->nd_opt_type]) {
1479                                 syslog(LOG_INFO,
1480                                     "<%s> duplicated ND option (type = %d)",
1481                                     __func__, hdr->nd_opt_type);
1482                         }
1483                         ndopts->opt_array[hdr->nd_opt_type] = hdr;
1484                         break;
1485                 case ND_OPT_PREFIX_INFORMATION:
1486                 {
1487                         struct nd_optlist *nol;
1488
1489                         if (ndopts->opt_pi == 0) {
1490                                 ndopts->opt_pi =
1491                                     (struct nd_opt_prefix_info *)hdr;
1492                                 continue;
1493                         }
1494                         nol = malloc(sizeof(*nol));
1495                         if (nol == NULL) {
1496                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1497                                     __func__);
1498                                 goto bad;
1499                         }
1500                         nol->nol_opt = hdr;
1501                         TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1502
1503                         break;
1504                 }
1505                 default:        /* impossible */
1506                         break;
1507                 }
1508         }
1509
1510         return (0);
1511
1512   bad:
1513         free_ndopts(ndopts);
1514
1515         return (-1);
1516 }
1517
1518 static void
1519 free_ndopts(union nd_opt *ndopts)
1520 {
1521         struct nd_optlist *nol;
1522
1523         while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1524                 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1525                 free(nol);
1526         }
1527 }
1528
1529 void
1530 sock_open(struct sockinfo *s)
1531 {
1532         struct icmp6_filter filt;
1533         int on;
1534         /* XXX: should be max MTU attached to the node */
1535         static char answer[1500];
1536
1537         syslog(LOG_DEBUG, "<%s> enter", __func__);
1538
1539         if (s == NULL) {
1540                 syslog(LOG_ERR, "<%s> internal error", __func__);
1541                 exit(1);
1542         }
1543         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1544             CMSG_SPACE(sizeof(int));
1545         rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1546         if (rcvcmsgbuf == NULL) {
1547                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1548                 exit(1);
1549         }
1550
1551         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1552             CMSG_SPACE(sizeof(int));
1553         sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1554         if (sndcmsgbuf == NULL) {
1555                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1556                 exit(1);
1557         }
1558
1559         if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1560                 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1561                 exit(1);
1562         }
1563         /* specify to tell receiving interface */
1564         on = 1;
1565         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1566             sizeof(on)) < 0) {
1567                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1568                     strerror(errno));
1569                 exit(1);
1570         }
1571         on = 1;
1572         /* specify to tell value of hoplimit field of received IP6 hdr */
1573         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1574                 sizeof(on)) < 0) {
1575                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1576                     strerror(errno));
1577                 exit(1);
1578         }
1579         ICMP6_FILTER_SETBLOCKALL(&filt);
1580         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1581         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1582         if (mcastif != NULL)
1583                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1584
1585         if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1586             sizeof(filt)) < 0) {
1587                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1588                     __func__, strerror(errno));
1589                 exit(1);
1590         }
1591
1592         /* initialize msghdr for receiving packets */
1593         rcviov[0].iov_base = (caddr_t)answer;
1594         rcviov[0].iov_len = sizeof(answer);
1595         rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1596         rcvmhdr.msg_namelen = sizeof(rcvfrom);
1597         rcvmhdr.msg_iov = rcviov;
1598         rcvmhdr.msg_iovlen = 1;
1599         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1600         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1601
1602         /* initialize msghdr for sending packets */
1603         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1604         sndmhdr.msg_iov = sndiov;
1605         sndmhdr.msg_iovlen = 1;
1606         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1607         sndmhdr.msg_controllen = sndcmsgbuflen;
1608
1609         return;
1610 }
1611
1612 /* open a routing socket to watch the routing table */
1613 static void
1614 rtsock_open(struct sockinfo *s)
1615 {
1616         if (s == NULL) {
1617                 syslog(LOG_ERR, "<%s> internal error", __func__);
1618                 exit(1);
1619         }
1620         if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1621                 syslog(LOG_ERR,
1622                     "<%s> socket: %s", __func__, strerror(errno));
1623                 exit(1);
1624         }
1625 }
1626
1627 struct ifinfo *
1628 if_indextoifinfo(int idx)
1629 {
1630         struct ifinfo *ifi;
1631         char name0[IFNAMSIZ];
1632
1633         /* Check if the interface has a valid name or not. */
1634         if (if_indextoname(idx, name0) == NULL)
1635                 return (NULL);
1636
1637         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1638                 if (ifi->ifi_ifindex == idx)
1639                         return (ifi);
1640         }
1641
1642         if (ifi != NULL)
1643                 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1644                     __func__, idx);
1645         else
1646                 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1647                     __func__, idx);
1648
1649         return (NULL);          /* search failed */
1650 }
1651
1652 void
1653 ra_output(struct ifinfo *ifi)
1654 {
1655         int i;
1656         struct cmsghdr *cm;
1657         struct in6_pktinfo *pi;
1658         struct soliciter *sol;
1659         struct rainfo *rai;
1660
1661         switch (ifi->ifi_state) {
1662         case IFI_STATE_CONFIGURED:
1663                 rai = ifi->ifi_rainfo;
1664                 break;
1665         case IFI_STATE_TRANSITIVE:
1666                 rai = ifi->ifi_rainfo_trans;
1667                 break;
1668         case IFI_STATE_UNCONFIGURED:
1669                 syslog(LOG_DEBUG, "<%s> %s is unconfigured.  "
1670                     "Skip sending RAs.",
1671                     __func__, ifi->ifi_ifname);
1672                 return;
1673         default:
1674                 rai = NULL;
1675         }
1676         if (rai == NULL) {
1677                 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1678                     "Skip sending RAs.",
1679                     __func__, ifi->ifi_ifname);
1680                 return;
1681         }
1682         if (!(ifi->ifi_flags & IFF_UP)) {
1683                 syslog(LOG_DEBUG, "<%s> %s is not up.  "
1684                     "Skip sending RAs.",
1685                     __func__, ifi->ifi_ifname);
1686                 return;
1687         }
1688         /*
1689          * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1690          *
1691          * (lifetime == 0) = output
1692          * (lifetime != 0 && (check_accept_rtadv()) = no output
1693          *
1694          * Basically, hosts MUST NOT send Router Advertisement
1695          * messages at any time (RFC 4861, Section 6.2.3). However, it
1696          * would sometimes be useful to allow hosts to advertise some
1697          * parameters such as prefix information and link MTU. Thus,
1698          * we allow hosts to invoke rtadvd only when router lifetime
1699          * (on every advertising interface) is explicitly set
1700          * zero. (see also the above section)
1701          */
1702         syslog(LOG_DEBUG,
1703             "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1704             "on %s", __func__,
1705             rai->rai_lifetime,
1706             check_accept_rtadv(ifi->ifi_ifindex),
1707             getinet6sysctl(IPV6CTL_FORWARDING),
1708             ifi->ifi_ifname);
1709
1710         if (rai->rai_lifetime != 0) {
1711                 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1712                         syslog(LOG_ERR,
1713                             "non-zero lifetime RA "
1714                             "but net.inet6.ip6.forwarding=0.  "
1715                             "Ignored.");
1716                         return;
1717                 }
1718                 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1719                         syslog(LOG_ERR,
1720                             "non-zero lifetime RA "
1721                             "on RA receiving interface %s."
1722                             "  Ignored.", ifi->ifi_ifname);
1723                         return;
1724                 }
1725         }
1726
1727         make_packet(rai);       /* XXX: inefficient */
1728
1729         sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1730         sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1731         sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1732
1733         cm = CMSG_FIRSTHDR(&sndmhdr);
1734         /* specify the outgoing interface */
1735         cm->cmsg_level = IPPROTO_IPV6;
1736         cm->cmsg_type = IPV6_PKTINFO;
1737         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1738         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1739         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1740         pi->ipi6_ifindex = ifi->ifi_ifindex;
1741
1742         /* specify the hop limit of the packet */
1743         {
1744                 int hoplimit = 255;
1745
1746                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1747                 cm->cmsg_level = IPPROTO_IPV6;
1748                 cm->cmsg_type = IPV6_HOPLIMIT;
1749                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1750                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1751         }
1752
1753         syslog(LOG_DEBUG,
1754             "<%s> send RA on %s, # of RS waitings = %d",
1755             __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1756
1757         i = sendmsg(sock.si_fd, &sndmhdr, 0);
1758
1759         if (i < 0 || (size_t)i != rai->rai_ra_datalen)  {
1760                 if (i < 0) {
1761                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1762                             __func__, ifi->ifi_ifname,
1763                             strerror(errno));
1764                 }
1765         }
1766
1767         /*
1768          * unicast advertisements
1769          * XXX commented out.  reason: though spec does not forbit it, unicast
1770          * advert does not really help
1771          */
1772         while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1773                 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1774                 free(sol);
1775         }
1776
1777         /* update timestamp */
1778         clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1779
1780         /* update counter */
1781         ifi->ifi_rs_waitcount = 0;
1782         ifi->ifi_raoutput++;
1783
1784         switch (ifi->ifi_state) {
1785         case IFI_STATE_CONFIGURED:
1786                 if (ifi->ifi_burstcount > 0)
1787                         ifi->ifi_burstcount--;
1788                 break;
1789         case IFI_STATE_TRANSITIVE:
1790                 ifi->ifi_burstcount--;
1791                 if (ifi->ifi_burstcount == 0) {
1792                         if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1793                                 /* Initial burst finished. */
1794                                 if (ifi->ifi_rainfo_trans != NULL)
1795                                         ifi->ifi_rainfo_trans = NULL;
1796                         }
1797
1798                         /* Remove burst RA information */
1799                         if (ifi->ifi_rainfo_trans != NULL) {
1800                                 rm_rainfo(ifi->ifi_rainfo_trans);
1801                                 ifi->ifi_rainfo_trans = NULL;
1802                         }
1803
1804                         if (ifi->ifi_rainfo != NULL) {
1805                                 /*
1806                                  * TRANSITIVE -> CONFIGURED
1807                                  *
1808                                  * After initial burst or transition from
1809                                  * one configuration to another,
1810                                  * ifi_rainfo always points to the next RA
1811                                  * information.
1812                                  */
1813                                 ifi->ifi_state = IFI_STATE_CONFIGURED;
1814                                 syslog(LOG_DEBUG,
1815                                     "<%s> ifname=%s marked as "
1816                                     "CONFIGURED.", __func__,
1817                                     ifi->ifi_ifname);
1818                         } else {
1819                                 /*
1820                                  * TRANSITIVE -> UNCONFIGURED
1821                                  *
1822                                  * If ifi_rainfo points to NULL, this
1823                                  * interface is shutting down.
1824                                  *
1825                                  */
1826                                 int error;
1827
1828                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1829                                 syslog(LOG_DEBUG,
1830                                     "<%s> ifname=%s marked as "
1831                                     "UNCONFIGURED.", __func__,
1832                                     ifi->ifi_ifname);
1833                                 error = sock_mc_leave(&sock,
1834                                     ifi->ifi_ifindex);
1835                                 if (error)
1836                                         exit(1);
1837                         }
1838                 }
1839                 break;
1840         }
1841 }
1842
1843 /* process RA timer */
1844 struct rtadvd_timer *
1845 ra_timeout(void *arg)
1846 {
1847         struct ifinfo *ifi;
1848
1849         ifi = (struct ifinfo *)arg;
1850         syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1851             __func__, ifi->ifi_ifname);
1852
1853         ra_output(ifi);
1854
1855         return (ifi->ifi_ra_timer);
1856 }
1857
1858 /* update RA timer */
1859 void
1860 ra_timer_update(void *arg, struct timespec *tm)
1861 {
1862         uint16_t interval;
1863         struct rainfo *rai;
1864         struct ifinfo *ifi;
1865
1866         ifi = (struct ifinfo *)arg;
1867         rai = ifi->ifi_rainfo;
1868         interval = 0;
1869
1870         switch (ifi->ifi_state) {
1871         case IFI_STATE_UNCONFIGURED:
1872                 return;
1873                 break;
1874         case IFI_STATE_CONFIGURED:
1875                 /*
1876                  * Whenever a multicast advertisement is sent from
1877                  * an interface, the timer is reset to a
1878                  * uniformly-distributed random value between the
1879                  * interface's configured MinRtrAdvInterval and
1880                  * MaxRtrAdvInterval (RFC4861 6.2.4).
1881                  */
1882                 interval = rai->rai_mininterval;
1883 #ifdef HAVE_ARC4RANDOM
1884                 interval += arc4random_uniform(rai->rai_maxinterval -
1885                     rai->rai_mininterval);
1886 #else
1887                 interval += random() % (rai->rai_maxinterval -
1888                     rai->rai_mininterval);
1889 #endif
1890                 break;
1891         case IFI_STATE_TRANSITIVE:
1892                 /*
1893                  * For the first few advertisements (up to
1894                  * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1895                  * interval is greater than
1896                  * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1897                  * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.  (RFC
1898                  * 4861 6.2.4)
1899                  *
1900                  * In such cases, the router SHOULD transmit one or more
1901                  * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1902                  * multicast Router Advertisements on the interface with a
1903                  * Router Lifetime field of zero.  (RFC 4861 6.2.5)
1904                  */
1905                 interval = ifi->ifi_burstinterval;
1906                 break;
1907         }
1908
1909         tm->tv_sec = interval;
1910         tm->tv_nsec = 0;
1911
1912         syslog(LOG_DEBUG,
1913             "<%s> RA timer on %s is set to %ld:%ld",
1914             __func__, ifi->ifi_ifname,
1915             (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1916
1917         return;
1918 }