usr.sbin/rtadvd/rtadvd.c

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