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 #ifdef __FreeBSD__
 248         srandomdev();
 249 #else
 250         srandom((unsigned long)time(NULL));
 251 #endif
 252 #endif
 253         pfh = pidfile_open(pidfilename, 0600, &otherpid);
 254         if (pfh == NULL) {
 255                 if (errno == EEXIST)
 256                         errx(1, "%s already running, pid: %d",
 257                             getprogname(), otherpid);
 258                 syslog(LOG_ERR,
 259                     "failed to open the pid file %s, run anyway.",
 260                     pidfilename);
 261         }
 262         if (!fflag)
 263                 daemon(1, 0);
 264
 265         sock_open(&sock);
 266
 267         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 268         for (i = 0; i < argc; i++)
 269                 update_persist_ifinfo(&ifilist, argv[i]);
 270
 271         csock_open(&ctrlsock, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 272         if (ctrlsock.si_fd == -1) {
 273                 syslog(LOG_ERR, "cannot open control socket: %s",
 274                     strerror(errno));
 275                 exit(1);
 276         }
 277
 278         /* record the current PID */
 279         pidfile_write(pfh);
 280
 281         set[PFD_RAWSOCK].fd = sock.si_fd;
 282         set[PFD_RAWSOCK].events = POLLIN;
 283         if (sflag == 0) {
 284                 rtsock_open(&rtsock);
 285                 set[PFD_RTSOCK].fd = rtsock.si_fd;
 286                 set[PFD_RTSOCK].events = POLLIN;
 287         } else
 288                 set[PFD_RTSOCK].fd = -1;
 289         set[PFD_CSOCK].fd = ctrlsock.si_fd;
 290         set[PFD_CSOCK].events = POLLIN;
 291         signal(SIGTERM, set_do_shutdown);
 292         signal(SIGINT, set_do_shutdown);
 293         signal(SIGHUP, set_do_reload);
 294
 295         error = csock_listen(&ctrlsock);
 296         if (error) {
 297                 syslog(LOG_ERR, "cannot listen control socket: %s",
 298                     strerror(errno));
 299                 exit(1);
 300         }
 301
 302         /* load configuration file */
 303         set_do_reload(0);
 304
 305         while (1) {
 306                 if (is_do_shutdown())
 307                         rtadvd_shutdown();
 308
 309                 if (is_do_reload()) {
 310                         loadconfig_ifname(reload_ifname());
 311                         if (reload_ifname() == NULL)
 312                                 syslog(LOG_INFO,
 313                                     "configuration file reloaded.");
 314                         else
 315                                 syslog(LOG_INFO,
 316                                     "configuration file for %s reloaded.",
 317                                     reload_ifname());
 318                         reset_do_reload();
 319                 }
 320
 321                 /* timeout handler update for active interfaces */
 322                 rtadvd_update_timeout_handler();
 323
 324                 /* timer expiration check and reset the timer */
 325                 timeout = rtadvd_check_timer();
 326
 327                 if (timeout != NULL) {
 328                         syslog(LOG_DEBUG,
 329                             "<%s> set timer to %ld:%ld. waiting for "
 330                             "inputs or timeout", __func__,
 331                             (long int)timeout->tv_sec,
 332                             (long int)timeout->tv_nsec / 1000);
 333                 } else {
 334                         syslog(LOG_DEBUG,
 335                             "<%s> there's no timer. waiting for inputs",
 336                             __func__);
 337                 }
 338                 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
 339                             timeout ? (timeout->tv_sec * 1000 +
 340                                 timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
 341
 342                         /* EINTR would occur if a signal was delivered */
 343                         if (errno != EINTR)
 344                                 syslog(LOG_ERR, "poll() failed: %s",
 345                                     strerror(errno));
 346                         continue;
 347                 }
 348                 if (i == 0)     /* timeout */
 349                         continue;
 350                 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
 351                         rtmsg_input(&rtsock);
 352
 353                 if (set[PFD_RAWSOCK].revents & POLLIN)
 354                         rtadvd_input(&sock);
 355
 356                 if (set[PFD_CSOCK].revents & POLLIN) {
 357                         int fd;
 358
 359                         fd = csock_accept(&ctrlsock);
 360                         if (fd == -1)
 361                                 syslog(LOG_ERR,
 362                                     "cannot accept() control socket: %s",
 363                                     strerror(errno));
 364                         else {
 365                                 cm_handler_server(fd);
 366                                 close(fd);
 367                         }
 368                 }
 369         }
 370         exit(0);                /* NOTREACHED */
 371 }
 372
 373 static void
 374 rtadvd_shutdown(void)
 375 {
 376         struct ifinfo *ifi;
 377         struct rainfo *rai;
 378         struct rdnss *rdn;
 379         struct dnssl *dns;
 380
 381         if (wait_shutdown) {
 382                 syslog(LOG_INFO,
 383                     "waiting expiration of the all RA timers.");
 384
 385                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 386                         /*
 387                          * Ignore !IFF_UP interfaces in waiting for shutdown.
 388                          */
 389                         if (!(ifi->ifi_flags & IFF_UP) &&
 390                             ifi->ifi_ra_timer != NULL) {
 391                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 392                                 rtadvd_remove_timer(ifi->ifi_ra_timer);
 393                                 ifi->ifi_ra_timer = NULL;
 394                                 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
 395                                     "Timer removed and marked as UNCONFIGURED.",
 396                                      __func__, ifi->ifi_ifname,
 397                                     ifi->ifi_ifindex);
 398                         }
 399                 }
 400                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 401                         if (ifi->ifi_ra_timer != NULL)
 402                                 break;
 403                 }
 404                 if (ifi == NULL) {
 405                         syslog(LOG_NOTICE, "gracefully terminated.");
 406                         exit(0);
 407                 }
 408
 409                 sleep(1);
 410                 return;
 411         }
 412
 413         syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
 414             __func__);
 415
 416         wait_shutdown = 1;
 417
 418         TAILQ_FOREACH(rai, &railist, rai_next) {
 419                 rai->rai_lifetime = 0;
 420                 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
 421                         rdn->rd_ltime = 0;
 422                 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
 423                         dns->dn_ltime = 0;
 424         }
 425         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 426                 if (!ifi->ifi_persist)
 427                         continue;
 428                 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
 429                         continue;
 430                 if (ifi->ifi_ra_timer == NULL)
 431                         continue;
 432                 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
 433                     ifi->ifi_ra_lastsent.tv_nsec == 0 &&
 434                     ifi->ifi_ra_timer != NULL) {
 435                         /*
 436                          * When RA configured but never sent,
 437                          * ignore the IF immediately.
 438                          */
 439                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 440                         ifi->ifi_ra_timer = NULL;
 441                         ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 442                         continue;
 443                 }
 444
 445                 ifi->ifi_state = IFI_STATE_TRANSITIVE;
 446
 447                 /* Mark as the shut-down state. */
 448                 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
 449                 ifi->ifi_rainfo = NULL;
 450
 451                 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
 452                 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
 453
 454                 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 455                 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 456                     ifi->ifi_ra_timer);
 457         }
 458         syslog(LOG_NOTICE, "final RA transmission started.");
 459
 460         pidfile_remove(pfh);
 461         csock_close(&ctrlsock);
 462 }
 463
 464 static void
 465 rtmsg_input(struct sockinfo *s)
 466 {
 467         int n, type, ifindex = 0, plen;
 468         size_t len;
 469         char msg[2048], *next, *lim;
 470         char ifname[IFNAMSIZ];
 471         struct if_announcemsghdr *ifan;
 472         struct rt_msghdr *rtm;
 473         struct prefix *pfx;
 474         struct rainfo *rai;
 475         struct in6_addr *addr;
 476         struct ifinfo *ifi;
 477         char addrbuf[INET6_ADDRSTRLEN];
 478         int prefixchange = 0;
 479
 480         if (s == NULL) {
 481                 syslog(LOG_ERR, "<%s> internal error", __func__);
 482                 exit(1);
 483         }
 484         n = read(s->si_fd, msg, sizeof(msg));
 485         rtm = (struct rt_msghdr *)msg;
 486         syslog(LOG_DEBUG, "<%s> received a routing message "
 487             "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
 488
 489         if (n > rtm->rtm_msglen) {
 490                 /*
 491                  * This usually won't happen for messages received on
 492                  * a routing socket.
 493                  */
 494                 syslog(LOG_DEBUG,
 495                     "<%s> received data length is larger than "
 496                     "1st routing message len. multiple messages? "
 497                     "read %d bytes, but 1st msg len = %d",
 498                     __func__, n, rtm->rtm_msglen);
 499 #if 0
 500                 /* adjust length */
 501                 n = rtm->rtm_msglen;
 502 #endif
 503         }
 504
 505         lim = msg + n;
 506         for (next = msg; next < lim; next += len) {
 507                 int oldifflags;
 508
 509                 next = get_next_msg(next, lim, 0, &len,
 510                     RTADV_TYPE2BITMASK(RTM_ADD) |
 511                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 512                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 513                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 514                     RTADV_TYPE2BITMASK(RTM_IFINFO) |
 515                     RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
 516                 if (len == 0)
 517                         break;
 518                 type = ((struct rt_msghdr *)next)->rtm_type;
 519                 switch (type) {
 520                 case RTM_ADD:
 521                 case RTM_DELETE:
 522                         ifindex = get_rtm_ifindex(next);
 523                         break;
 524                 case RTM_NEWADDR:
 525                 case RTM_DELADDR:
 526                         ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
 527                         break;
 528                 case RTM_IFINFO:
 529                         ifindex = (int)((struct if_msghdr *)next)->ifm_index;
 530                         break;
 531                 case RTM_IFANNOUNCE:
 532                         ifan = (struct if_announcemsghdr *)next;
 533                         switch (ifan->ifan_what) {
 534                         case IFAN_ARRIVAL:
 535                         case IFAN_DEPARTURE:
 536                                 break;
 537                         default:
 538                                 syslog(LOG_DEBUG,
 539                                     "<%s:%d> unknown ifan msg (ifan_what=%d)",
 540                                    __func__, __LINE__, ifan->ifan_what);
 541                                 continue;
 542                         }
 543
 544                         syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
 545                                __func__, ifan->ifan_index, ifan->ifan_what);
 546                         switch (ifan->ifan_what) {
 547                         case IFAN_ARRIVAL:
 548                                 syslog(LOG_NOTICE,
 549                                     "interface added (idx=%d)",
 550                                     ifan->ifan_index);
 551                                 update_ifinfo(&ifilist, ifan->ifan_index);
 552                                 loadconfig_index(ifan->ifan_index);
 553                                 break;
 554                         case IFAN_DEPARTURE:
 555                                 syslog(LOG_NOTICE,
 556                                     "interface removed (idx=%d)",
 557                                     ifan->ifan_index);
 558                                 rm_ifinfo_index(ifan->ifan_index);
 559
 560                                 /* Clear ifi_ifindex */
 561                                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 562                                         if (ifi->ifi_ifindex
 563                                             == ifan->ifan_index) {
 564                                                 ifi->ifi_ifindex = 0;
 565                                                 break;
 566                                         }
 567                                 }
 568                                 update_ifinfo(&ifilist, ifan->ifan_index);
 569                                 break;
 570                         }
 571                         continue;
 572                 default:
 573                         /* should not reach here */
 574                         syslog(LOG_DEBUG,
 575                                "<%s:%d> unknown rtmsg %d on %s",
 576                                __func__, __LINE__, type,
 577                                if_indextoname(ifindex, ifname));
 578                         continue;
 579                 }
 580                 ifi = if_indextoifinfo(ifindex);
 581                 if (ifi == NULL) {
 582                         syslog(LOG_DEBUG,
 583                             "<%s> ifinfo not found for idx=%d.  Why?",
 584                             __func__, ifindex);
 585                         continue;
 586                 }
 587                 rai = ifi->ifi_rainfo;
 588                 if (rai == NULL) {
 589                         syslog(LOG_DEBUG,
 590                             "<%s> route changed on "
 591                             "non advertising interface(%s)",
 592                             __func__, ifi->ifi_ifname);
 593                         continue;
 594                 }
 595
 596                 oldifflags = ifi->ifi_flags;
 597                 /* init ifflags because it may have changed */
 598                 update_ifinfo(&ifilist, ifindex);
 599
 600                 switch (type) {
 601                 case RTM_ADD:
 602                         if (sflag)
 603                                 break;  /* we aren't interested in prefixes  */
 604
 605                         addr = get_addr(msg);
 606                         plen = get_prefixlen(msg);
 607                         /* sanity check for plen */
 608                         /* as RFC2373, prefixlen is at least 4 */
 609                         if (plen < 4 || plen > 127) {
 610                                 syslog(LOG_INFO, "<%s> new interface route's"
 611                                     "plen %d is invalid for a prefix",
 612                                     __func__, plen);
 613                                 break;
 614                         }
 615                         pfx = find_prefix(rai, addr, plen);
 616                         if (pfx) {
 617                                 if (pfx->pfx_timer) {
 618                                         /*
 619                                          * If the prefix has been invalidated,
 620                                          * make it available again.
 621                                          */
 622                                         update_prefix(pfx);
 623                                         prefixchange = 1;
 624                                 } else
 625                                         syslog(LOG_DEBUG,
 626                                             "<%s> new prefix(%s/%d) "
 627                                             "added on %s, "
 628                                             "but it was already in list",
 629                                             __func__,
 630                                             inet_ntop(AF_INET6, addr,
 631                                                 (char *)addrbuf,
 632                                                 sizeof(addrbuf)),
 633                                             plen, ifi->ifi_ifname);
 634                                 break;
 635                         }
 636                         make_prefix(rai, ifindex, addr, plen);
 637                         prefixchange = 1;
 638                         break;
 639                 case RTM_DELETE:
 640                         if (sflag)
 641                                 break;
 642
 643                         addr = get_addr(msg);
 644                         plen = get_prefixlen(msg);
 645                         /* sanity check for plen */
 646                         /* as RFC2373, prefixlen is at least 4 */
 647                         if (plen < 4 || plen > 127) {
 648                                 syslog(LOG_INFO,
 649                                     "<%s> deleted interface route's "
 650                                     "plen %d is invalid for a prefix",
 651                                     __func__, plen);
 652                                 break;
 653                         }
 654                         pfx = find_prefix(rai, addr, plen);
 655                         if (pfx == NULL) {
 656                                 syslog(LOG_DEBUG,
 657                                     "<%s> prefix(%s/%d) was deleted on %s, "
 658                                     "but it was not in list",
 659                                     __func__, inet_ntop(AF_INET6, addr,
 660                                         (char *)addrbuf, sizeof(addrbuf)),
 661                                         plen, ifi->ifi_ifname);
 662                                 break;
 663                         }
 664                         invalidate_prefix(pfx);
 665                         prefixchange = 1;
 666                         break;
 667                 case RTM_NEWADDR:
 668                 case RTM_DELADDR:
 669                 case RTM_IFINFO:
 670                         break;
 671                 default:
 672                         /* should not reach here */
 673                         syslog(LOG_DEBUG,
 674                             "<%s:%d> unknown rtmsg %d on %s",
 675                             __func__, __LINE__, type,
 676                             if_indextoname(ifindex, ifname));
 677                         return;
 678                 }
 679
 680                 /* check if an interface flag is changed */
 681                 if ((oldifflags & IFF_UP) && /* UP to DOWN */
 682                     !(ifi->ifi_flags & IFF_UP)) {
 683                         syslog(LOG_NOTICE,
 684                             "<interface %s becomes down. stop timer.",
 685                             ifi->ifi_ifname);
 686                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 687                         ifi->ifi_ra_timer = NULL;
 688                 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
 689                     (ifi->ifi_flags & IFF_UP)) {
 690                         syslog(LOG_NOTICE,
 691                             "interface %s becomes up. restart timer.",
 692                             ifi->ifi_ifname);
 693
 694                         ifi->ifi_state = IFI_STATE_TRANSITIVE;
 695                         ifi->ifi_burstcount =
 696                             MAX_INITIAL_RTR_ADVERTISEMENTS;
 697                         ifi->ifi_burstinterval =
 698                             MAX_INITIAL_RTR_ADVERT_INTERVAL;
 699
 700                         ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
 701                             ra_timer_update, ifi, ifi);
 702                         ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 703                         rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 704                             ifi->ifi_ra_timer);
 705                 } else if (prefixchange &&
 706                     (ifi->ifi_flags & IFF_UP)) {
 707                         /*
 708                          * An advertised prefix has been added or invalidated.
 709                          * Will notice the change in a short delay.
 710                          */
 711                         set_short_delay(ifi);
 712                 }
 713         }
 714
 715         return;
 716 }
 717
 718 void
 719 rtadvd_input(struct sockinfo *s)
 720 {
 721         ssize_t i;
 722         int *hlimp = NULL;
 723 #ifdef OLDRAWSOCKET
 724         struct ip6_hdr *ip;
 725 #endif
 726         struct icmp6_hdr *icp;
 727         int ifindex = 0;
 728         struct cmsghdr *cm;
 729         struct in6_pktinfo *pi = NULL;
 730         char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 731         struct in6_addr dst = in6addr_any;
 732         struct ifinfo *ifi;
 733
 734         syslog(LOG_DEBUG, "<%s> enter", __func__);
 735
 736         if (s == NULL) {
 737                 syslog(LOG_ERR, "<%s> internal error", __func__);
 738                 exit(1);
 739         }
 740         /*
 741          * Get message. We reset msg_controllen since the field could
 742          * be modified if we had received a message before setting
 743          * receive options.
 744          */
 745         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 746         if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
 747                 return;
 748
 749         /* extract optional information via Advanced API */
 750         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 751              cm;
 752              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 753                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 754                     cm->cmsg_type == IPV6_PKTINFO &&
 755                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 756                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 757                         ifindex = pi->ipi6_ifindex;
 758                         dst = pi->ipi6_addr;
 759                 }
 760                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 761                     cm->cmsg_type == IPV6_HOPLIMIT &&
 762                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 763                         hlimp = (int *)CMSG_DATA(cm);
 764         }
 765         if (ifindex == 0) {
 766                 syslog(LOG_ERR, "failed to get receiving interface");
 767                 return;
 768         }
 769         if (hlimp == NULL) {
 770                 syslog(LOG_ERR, "failed to get receiving hop limit");
 771                 return;
 772         }
 773
 774         /*
 775          * If we happen to receive data on an interface which is now gone
 776          * or down, just discard the data.
 777          */
 778         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 779         if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
 780                 syslog(LOG_INFO,
 781                     "<%s> received data on a disabled interface (%s)",
 782                     __func__,
 783                     (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
 784                 return;
 785         }
 786
 787 #ifdef OLDRAWSOCKET
 788         if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 789                 syslog(LOG_ERR,
 790                     "packet size(%d) is too short", i);
 791                 return;
 792         }
 793
 794         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 795         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 796 #else
 797         if ((size_t)i < sizeof(struct icmp6_hdr)) {
 798                 syslog(LOG_ERR, "packet size(%zd) is too short", i);
 799                 return;
 800         }
 801
 802         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 803 #endif
 804
 805         switch (icp->icmp6_type) {
 806         case ND_ROUTER_SOLICIT:
 807                 /*
 808                  * Message verification - RFC 4861 6.1.1
 809                  * XXX: these checks must be done in the kernel as well,
 810                  *      but we can't completely rely on them.
 811                  */
 812                 if (*hlimp != 255) {
 813                         syslog(LOG_NOTICE,
 814                             "RS with invalid hop limit(%d) "
 815                             "received from %s on %s",
 816                             *hlimp,
 817                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 818                             sizeof(ntopbuf)),
 819                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 820                         return;
 821                 }
 822                 if (icp->icmp6_code) {
 823                         syslog(LOG_NOTICE,
 824                             "RS with invalid ICMP6 code(%d) "
 825                             "received from %s on %s",
 826                             icp->icmp6_code,
 827                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 828                             sizeof(ntopbuf)),
 829                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 830                         return;
 831                 }
 832                 if ((size_t)i < sizeof(struct nd_router_solicit)) {
 833                         syslog(LOG_NOTICE,
 834                             "RS from %s on %s does not have enough "
 835                             "length (len = %zd)",
 836                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 837                             sizeof(ntopbuf)),
 838                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 839                         return;
 840                 }
 841                 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
 842                 break;
 843         case ND_ROUTER_ADVERT:
 844                 /*
 845                  * Message verification - RFC 4861 6.1.2
 846                  * XXX: there's the same dilemma as above...
 847                  */
 848                 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
 849                         syslog(LOG_NOTICE,
 850                             "RA with non-linklocal source address "
 851                             "received from %s on %s",
 852                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
 853                             ntopbuf, sizeof(ntopbuf)),
 854                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 855                         return;
 856                 }
 857                 if (*hlimp != 255) {
 858                         syslog(LOG_NOTICE,
 859                             "RA with invalid hop limit(%d) "
 860                             "received from %s on %s",
 861                             *hlimp,
 862                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 863                             sizeof(ntopbuf)),
 864                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 865                         return;
 866                 }
 867                 if (icp->icmp6_code) {
 868                         syslog(LOG_NOTICE,
 869                             "RA with invalid ICMP6 code(%d) "
 870                             "received from %s on %s",
 871                             icp->icmp6_code,
 872                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 873                             sizeof(ntopbuf)),
 874                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 875                         return;
 876                 }
 877                 if ((size_t)i < sizeof(struct nd_router_advert)) {
 878                         syslog(LOG_NOTICE,
 879                             "RA from %s on %s does not have enough "
 880                             "length (len = %zd)",
 881                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 882                             sizeof(ntopbuf)),
 883                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 884                         return;
 885                 }
 886                 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
 887                 break;
 888         case ICMP6_ROUTER_RENUMBERING:
 889                 if (mcastif == NULL) {
 890                         syslog(LOG_ERR, "received a router renumbering "
 891                             "message, but not allowed to be accepted");
 892                         break;
 893                 }
 894                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
 895                     &dst);
 896                 break;
 897         default:
 898                 /*
 899                  * Note that this case is POSSIBLE, especially just
 900                  * after invocation of the daemon. This is because we
 901                  * could receive message after opening the socket and
 902                  * before setting ICMP6 type filter(see sock_open()).
 903                  */
 904                 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
 905                 return;
 906         }
 907
 908         return;
 909 }
 910
 911 static void
 912 rs_input(int len, struct nd_router_solicit *rs,
 913          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 914 {
 915         char ntopbuf[INET6_ADDRSTRLEN];
 916         char ifnamebuf[IFNAMSIZ];
 917         union nd_opt ndopts;
 918         struct rainfo *rai;
 919         struct ifinfo *ifi;
 920         struct soliciter *sol;
 921
 922         syslog(LOG_DEBUG,
 923             "<%s> RS received from %s on %s",
 924             __func__,
 925             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
 926             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 927
 928         /* ND option check */
 929         memset(&ndopts, 0, sizeof(ndopts));
 930         TAILQ_INIT(&ndopts.opt_list);
 931         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 932                         len - sizeof(struct nd_router_solicit),
 933                         &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 934                 syslog(LOG_INFO,
 935                     "<%s> ND option check failed for an RS from %s on %s",
 936                     __func__,
 937                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
 938                         sizeof(ntopbuf)),
 939                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 940                 return;
 941         }
 942
 943         /*
 944          * If the IP source address is the unspecified address, there
 945          * must be no source link-layer address option in the message.
 946          * (RFC 4861 6.1.1)
 947          */
 948         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 949             ndopts.opt_src_lladdr) {
 950                 syslog(LOG_INFO,
 951                     "<%s> RS from unspecified src on %s has a link-layer"
 952                     " address option",
 953                     __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 954                 goto done;
 955         }
 956
 957         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 958         if (ifi == NULL) {
 959                 syslog(LOG_INFO,
 960                     "<%s> if (idx=%d) not found.  Why?",
 961                     __func__, pi->ipi6_ifindex);
 962                 goto done;
 963         }
 964         rai = ifi->ifi_rainfo;
 965         if (rai == NULL) {
 966                 syslog(LOG_INFO,
 967                        "<%s> RS received on non advertising interface(%s)",
 968                        __func__,
 969                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 970                 goto done;
 971         }
 972
 973         rai->rai_ifinfo->ifi_rsinput++;
 974
 975         /*
 976          * Decide whether to send RA according to the rate-limit
 977          * consideration.
 978          */
 979
 980         /* record sockaddr waiting for RA, if possible */
 981         sol = (struct soliciter *)malloc(sizeof(*sol));
 982         if (sol) {
 983                 sol->sol_addr = *from;
 984                 /* XXX RFC 2553 need clarification on flowinfo */
 985                 sol->sol_addr.sin6_flowinfo = 0;
 986                 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
 987         }
 988
 989         /*
 990          * If there is already a waiting RS packet, don't
 991          * update the timer.
 992          */
 993         if (ifi->ifi_rs_waitcount++)
 994                 goto done;
 995
 996         set_short_delay(ifi);
 997
 998   done:
 999         free_ndopts(&ndopts);
1000         return;
1001 }
1002
1003 static void
1004 set_short_delay(struct ifinfo *ifi)
1005 {
1006         long delay;     /* must not be greater than 1000000 */
1007         struct timespec interval, now, min_delay, tm_tmp, *rest;
1008
1009         if (ifi->ifi_ra_timer == NULL)
1010                 return;
1011         /*
1012          * Compute a random delay. If the computed value
1013          * corresponds to a time later than the time the next
1014          * multicast RA is scheduled to be sent, ignore the random
1015          * delay and send the advertisement at the
1016          * already-scheduled time. RFC 4861 6.2.6
1017          */
1018 #ifdef HAVE_ARC4RANDOM
1019         delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1020 #else
1021         delay = random() % MAX_RA_DELAY_TIME;
1022 #endif
1023         interval.tv_sec = 0;
1024         interval.tv_nsec = delay * 1000;
1025         rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1026         if (TS_CMP(rest, &interval, <)) {
1027                 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1028                     "the rest of the current timer", __func__);
1029                 interval = *rest;
1030         }
1031
1032         /*
1033          * If we sent a multicast Router Advertisement within
1034          * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1035          * the advertisement to be sent at a time corresponding to
1036          * MIN_DELAY_BETWEEN_RAS plus the random value after the
1037          * previous advertisement was sent.
1038          */
1039         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1040         TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1041         min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1042         min_delay.tv_nsec = 0;
1043         if (TS_CMP(&tm_tmp, &min_delay, <)) {
1044                 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1045                 TS_ADD(&min_delay, &interval, &interval);
1046         }
1047         rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1048 }
1049
1050 static int
1051 check_accept_rtadv(int idx)
1052 {
1053         struct ifinfo *ifi;
1054
1055         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1056                 if (ifi->ifi_ifindex == idx)
1057                         break;
1058         }
1059         if (ifi == NULL) {
1060                 syslog(LOG_DEBUG,
1061                     "<%s> if (idx=%d) not found.  Why?",
1062                     __func__, idx);
1063                 return (0);
1064         }
1065 #if (__FreeBSD_version < 900000)
1066         /*
1067          * RA_RECV: !ip6.forwarding && ip6.accept_rtadv
1068          * RA_SEND: ip6.forwarding
1069          */
1070         return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
1071             (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
1072 #else
1073         /*
1074          * RA_RECV: ND6_IFF_ACCEPT_RTADV
1075          * RA_SEND: ip6.forwarding
1076          */
1077         if (update_ifinfo_nd_flags(ifi) != 0) {
1078                 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1079                 return (0);
1080         }
1081
1082         return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1083 #endif
1084 }
1085
1086 static void
1087 ra_input(int len, struct nd_router_advert *nra,
1088          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1089 {
1090         struct rainfo *rai;
1091         struct ifinfo *ifi;
1092         char ntopbuf[INET6_ADDRSTRLEN];
1093         char ifnamebuf[IFNAMSIZ];
1094         union nd_opt ndopts;
1095         const char *on_off[] = {"OFF", "ON"};
1096         uint32_t reachabletime, retranstimer, mtu;
1097         int inconsistent = 0;
1098         int error;
1099
1100         syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1101             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1102             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1103
1104         /* ND option check */
1105         memset(&ndopts, 0, sizeof(ndopts));
1106         TAILQ_INIT(&ndopts.opt_list);
1107         error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1108             len - sizeof(struct nd_router_advert), &ndopts,
1109             NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1110             NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1111         if (error) {
1112                 syslog(LOG_INFO,
1113                     "<%s> ND option check failed for an RA from %s on %s",
1114                     __func__,
1115                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1116                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1117                         ifnamebuf));
1118                 return;
1119         }
1120
1121         /*
1122          * RA consistency check according to RFC 4861 6.2.7
1123          */
1124         ifi = if_indextoifinfo(pi->ipi6_ifindex);
1125         if (ifi->ifi_rainfo == NULL) {
1126                 syslog(LOG_INFO,
1127                     "<%s> received RA from %s on non-advertising"
1128                     " interface(%s)",
1129                     __func__,
1130                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1131                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1132                         ifnamebuf));
1133                 goto done;
1134         }
1135         rai = ifi->ifi_rainfo;
1136         ifi->ifi_rainput++;
1137         syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1138             ifi->ifi_rainput);
1139
1140         /* Cur Hop Limit value */
1141         if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1142             nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1143                 syslog(LOG_NOTICE,
1144                     "CurHopLimit inconsistent on %s:"
1145                     " %d from %s, %d from us",
1146                     ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1147                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1148                         sizeof(ntopbuf)), rai->rai_hoplimit);
1149                 inconsistent++;
1150         }
1151         /* M flag */
1152         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1153             rai->rai_managedflg) {
1154                 syslog(LOG_NOTICE,
1155                     "M flag inconsistent on %s:"
1156                     " %s from %s, %s from us",
1157                     ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1158                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1159                         sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1160                 inconsistent++;
1161         }
1162         /* O flag */
1163         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1164             rai->rai_otherflg) {
1165                 syslog(LOG_NOTICE,
1166                     "O flag inconsistent on %s:"
1167                     " %s from %s, %s from us",
1168                     ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1169                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1170                         sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1171                 inconsistent++;
1172         }
1173         /* Reachable Time */
1174         reachabletime = ntohl(nra->nd_ra_reachable);
1175         if (reachabletime && rai->rai_reachabletime &&
1176             reachabletime != rai->rai_reachabletime) {
1177                 syslog(LOG_NOTICE,
1178                     "ReachableTime inconsistent on %s:"
1179                     " %d from %s, %d from us",
1180                     ifi->ifi_ifname, reachabletime,
1181                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1182                         sizeof(ntopbuf)), rai->rai_reachabletime);
1183                 inconsistent++;
1184         }
1185         /* Retrans Timer */
1186         retranstimer = ntohl(nra->nd_ra_retransmit);
1187         if (retranstimer && rai->rai_retranstimer &&
1188             retranstimer != rai->rai_retranstimer) {
1189                 syslog(LOG_NOTICE,
1190                     "RetranceTimer inconsistent on %s:"
1191                     " %d from %s, %d from us",
1192                     ifi->ifi_ifname, retranstimer,
1193                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1194                         sizeof(ntopbuf)), rai->rai_retranstimer);
1195                 inconsistent++;
1196         }
1197         /* Values in the MTU options */
1198         if (ndopts.opt_mtu) {
1199                 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1200                 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1201                         syslog(LOG_NOTICE,
1202                             "MTU option value inconsistent on %s:"
1203                             " %d from %s, %d from us",
1204                             ifi->ifi_ifname, mtu,
1205                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1206                                 sizeof(ntopbuf)), rai->rai_linkmtu);
1207                         inconsistent++;
1208                 }
1209         }
1210         /* Preferred and Valid Lifetimes for prefixes */
1211         {
1212                 struct nd_optlist *nol;
1213
1214                 if (ndopts.opt_pi)
1215                         if (prefix_check(ndopts.opt_pi, rai, from))
1216                                 inconsistent++;
1217
1218                 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1219                         if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1220                                 rai, from))
1221                                 inconsistent++;
1222         }
1223
1224         if (inconsistent)
1225                 ifi->ifi_rainconsistent++;
1226
1227   done:
1228         free_ndopts(&ndopts);
1229         return;
1230 }
1231
1232 static uint32_t
1233 udiff(uint32_t u, uint32_t v)
1234 {
1235         return (u >= v ? u - v : v - u);
1236 }
1237
1238 /* return a non-zero value if the received prefix is inconsitent with ours */
1239 static int
1240 prefix_check(struct nd_opt_prefix_info *pinfo,
1241         struct rainfo *rai, struct sockaddr_in6 *from)
1242 {
1243         struct ifinfo *ifi;
1244         uint32_t preferred_time, valid_time;
1245         struct prefix *pfx;
1246         int inconsistent = 0;
1247         char ntopbuf[INET6_ADDRSTRLEN];
1248         char prefixbuf[INET6_ADDRSTRLEN];
1249         struct timespec now;
1250
1251 #if 0                           /* impossible */
1252         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1253                 return (0);
1254 #endif
1255         ifi = rai->rai_ifinfo;
1256         /*
1257          * log if the adveritsed prefix has link-local scope(sanity check?)
1258          */
1259         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix))
1260                 syslog(LOG_INFO,
1261                     "<%s> link-local prefix %s/%d is advertised "
1262                     "from %s on %s",
1263                     __func__,
1264                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1265                         sizeof(prefixbuf)),
1266                     pinfo->nd_opt_pi_prefix_len,
1267                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1268                         sizeof(ntopbuf)), ifi->ifi_ifname);
1269
1270         if ((pfx = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1271                 pinfo->nd_opt_pi_prefix_len)) == NULL) {
1272                 syslog(LOG_INFO,
1273                     "<%s> prefix %s/%d from %s on %s is not in our list",
1274                     __func__,
1275                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1276                         sizeof(prefixbuf)),
1277                     pinfo->nd_opt_pi_prefix_len,
1278                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1279                         sizeof(ntopbuf)), ifi->ifi_ifname);
1280                 return (0);
1281         }
1282
1283         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1284         if (pfx->pfx_pltimeexpire) {
1285                 /*
1286                  * The lifetime is decremented in real time, so we should
1287                  * compare the expiration time.
1288                  * (RFC 2461 Section 6.2.7.)
1289                  * XXX: can we really expect that all routers on the link
1290                  * have synchronized clocks?
1291                  */
1292                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1293                 preferred_time += now.tv_sec;
1294
1295                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1296                     udiff(preferred_time, pfx->pfx_pltimeexpire) > rai->rai_clockskew) {
1297                         syslog(LOG_INFO,
1298                             "<%s> preferred lifetime for %s/%d"
1299                             " (decr. in real time) inconsistent on %s:"
1300                             " %" PRIu32 " from %s, %" PRIu32 " from us",
1301                             __func__,
1302                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1303                                 sizeof(prefixbuf)),
1304                             pinfo->nd_opt_pi_prefix_len,
1305                             ifi->ifi_ifname, preferred_time,
1306                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1307                                 sizeof(ntopbuf)), pfx->pfx_pltimeexpire);
1308                         inconsistent++;
1309                 }
1310         } else if (!pfx->pfx_timer && preferred_time != pfx->pfx_preflifetime)
1311                 syslog(LOG_INFO,
1312                     "<%s> preferred lifetime for %s/%d"
1313                     " inconsistent on %s:"
1314                     " %d from %s, %d from us",
1315                     __func__,
1316                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1317                         sizeof(prefixbuf)),
1318                     pinfo->nd_opt_pi_prefix_len,
1319                     ifi->ifi_ifname, preferred_time,
1320                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1321                         sizeof(ntopbuf)), pfx->pfx_preflifetime);
1322
1323         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1324         if (pfx->pfx_vltimeexpire) {
1325                 clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1326                 valid_time += now.tv_sec;
1327
1328                 if (!pfx->pfx_timer && rai->rai_clockskew &&
1329                     udiff(valid_time, pfx->pfx_vltimeexpire) > rai->rai_clockskew) {
1330                         syslog(LOG_INFO,
1331                             "<%s> valid lifetime for %s/%d"
1332                             " (decr. in real time) inconsistent on %s:"
1333                             " %d from %s, %" PRIu32 " from us",
1334                             __func__,
1335                             inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1336                                 sizeof(prefixbuf)),
1337                             pinfo->nd_opt_pi_prefix_len,
1338                             ifi->ifi_ifname, preferred_time,
1339                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1340                                 sizeof(ntopbuf)), pfx->pfx_vltimeexpire);
1341                         inconsistent++;
1342                 }
1343         } else if (!pfx->pfx_timer && valid_time != pfx->pfx_validlifetime) {
1344                 syslog(LOG_INFO,
1345                     "<%s> valid lifetime for %s/%d"
1346                     " inconsistent on %s:"
1347                     " %d from %s, %d from us",
1348                     __func__,
1349                     inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix, prefixbuf,
1350                         sizeof(prefixbuf)),
1351                     pinfo->nd_opt_pi_prefix_len,
1352                     ifi->ifi_ifname, valid_time,
1353                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1354                         sizeof(ntopbuf)), pfx->pfx_validlifetime);
1355                 inconsistent++;
1356         }
1357
1358         return (inconsistent);
1359 }
1360
1361 struct prefix *
1362 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1363 {
1364         struct prefix *pfx;
1365         int bytelen, bitlen;
1366         char bitmask;
1367
1368         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
1369                 if (plen != pfx->pfx_prefixlen)
1370                         continue;
1371
1372                 bytelen = plen / 8;
1373                 bitlen = plen % 8;
1374                 bitmask = 0xff << (8 - bitlen);
1375
1376                 if (memcmp((void *)prefix, (void *)&pfx->pfx_prefix, bytelen))
1377                         continue;
1378
1379                 if (bitlen == 0 ||
1380                     ((prefix->s6_addr[bytelen] & bitmask) ==
1381                      (pfx->pfx_prefix.s6_addr[bytelen] & bitmask))) {
1382                         return (pfx);
1383                 }
1384         }
1385
1386         return (NULL);
1387 }
1388
1389 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1390 int
1391 prefix_match(struct in6_addr *p0, int plen0,
1392         struct in6_addr *p1, int plen1)
1393 {
1394         int bytelen, bitlen;
1395         char bitmask;
1396
1397         if (plen0 < plen1)
1398                 return (0);
1399
1400         bytelen = plen1 / 8;
1401         bitlen = plen1 % 8;
1402         bitmask = 0xff << (8 - bitlen);
1403
1404         if (memcmp((void *)p0, (void *)p1, bytelen))
1405                 return (0);
1406
1407         if (bitlen == 0 ||
1408             ((p0->s6_addr[bytelen] & bitmask) ==
1409              (p1->s6_addr[bytelen] & bitmask))) {
1410                 return (1);
1411         }
1412
1413         return (0);
1414 }
1415
1416 static int
1417 nd6_options(struct nd_opt_hdr *hdr, int limit,
1418         union nd_opt *ndopts, uint32_t optflags)
1419 {
1420         int optlen = 0;
1421
1422         for (; limit > 0; limit -= optlen) {
1423                 if ((size_t)limit < sizeof(struct nd_opt_hdr)) {
1424                         syslog(LOG_INFO, "<%s> short option header", __func__);
1425                         goto bad;
1426                 }
1427
1428                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1429                 if (hdr->nd_opt_len == 0) {
1430                         syslog(LOG_INFO,
1431                             "<%s> bad ND option length(0) (type = %d)",
1432                             __func__, hdr->nd_opt_type);
1433                         goto bad;
1434                 }
1435                 optlen = hdr->nd_opt_len << 3;
1436                 if (optlen > limit) {
1437                         syslog(LOG_INFO, "<%s> short option", __func__);
1438                         goto bad;
1439                 }
1440
1441                 if (hdr->nd_opt_type > ND_OPT_MTU &&
1442                     hdr->nd_opt_type != ND_OPT_RDNSS &&
1443                     hdr->nd_opt_type != ND_OPT_DNSSL) {
1444                         syslog(LOG_INFO, "<%s> unknown ND option(type %d)",
1445                             __func__, hdr->nd_opt_type);
1446                         continue;
1447                 }
1448
1449                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1450                         syslog(LOG_INFO, "<%s> unexpected ND option(type %d)",
1451                             __func__, hdr->nd_opt_type);
1452                         continue;
1453                 }
1454
1455                 /*
1456                  * Option length check.  Do it here for all fixed-length
1457                  * options.
1458                  */
1459                 switch (hdr->nd_opt_type) {
1460                 case ND_OPT_MTU:
1461                         if (optlen == sizeof(struct nd_opt_mtu))
1462                                 break;
1463                         goto skip;
1464                 case ND_OPT_RDNSS:
1465                         if (optlen >= 24 &&
1466                             (optlen - sizeof(struct nd_opt_rdnss)) % 16 == 0)
1467                                 break;
1468                         goto skip;
1469                 case ND_OPT_DNSSL:
1470                         if (optlen >= 16 &&
1471                             (optlen - sizeof(struct nd_opt_dnssl)) % 8 == 0)
1472                                 break;
1473                         goto skip;
1474                 case ND_OPT_PREFIX_INFORMATION:
1475                         if (optlen == sizeof(struct nd_opt_prefix_info))
1476                                 break;
1477 skip:
1478                         syslog(LOG_INFO, "<%s> invalid option length",
1479                             __func__);
1480                         continue;
1481                 }
1482
1483                 switch (hdr->nd_opt_type) {
1484                 case ND_OPT_TARGET_LINKADDR:
1485                 case ND_OPT_REDIRECTED_HEADER:
1486                 case ND_OPT_RDNSS:
1487                 case ND_OPT_DNSSL:
1488                         break;  /* we don't care about these options */
1489                 case ND_OPT_SOURCE_LINKADDR:
1490                 case ND_OPT_MTU:
1491                         if (ndopts->opt_array[hdr->nd_opt_type]) {
1492                                 syslog(LOG_INFO,
1493                                     "<%s> duplicated ND option (type = %d)",
1494                                     __func__, hdr->nd_opt_type);
1495                         }
1496                         ndopts->opt_array[hdr->nd_opt_type] = hdr;
1497                         break;
1498                 case ND_OPT_PREFIX_INFORMATION:
1499                 {
1500                         struct nd_optlist *nol;
1501
1502                         if (ndopts->opt_pi == 0) {
1503                                 ndopts->opt_pi =
1504                                     (struct nd_opt_prefix_info *)hdr;
1505                                 continue;
1506                         }
1507                         nol = malloc(sizeof(*nol));
1508                         if (nol == NULL) {
1509                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1510                                     __func__);
1511                                 goto bad;
1512                         }
1513                         nol->nol_opt = hdr;
1514                         TAILQ_INSERT_TAIL(&(ndopts->opt_list), nol, nol_next);
1515
1516                         break;
1517                 }
1518                 default:        /* impossible */
1519                         break;
1520                 }
1521         }
1522
1523         return (0);
1524
1525   bad:
1526         free_ndopts(ndopts);
1527
1528         return (-1);
1529 }
1530
1531 static void
1532 free_ndopts(union nd_opt *ndopts)
1533 {
1534         struct nd_optlist *nol;
1535
1536         while ((nol = TAILQ_FIRST(&ndopts->opt_list)) != NULL) {
1537                 TAILQ_REMOVE(&ndopts->opt_list, nol, nol_next);
1538                 free(nol);
1539         }
1540 }
1541
1542 void
1543 sock_open(struct sockinfo *s)
1544 {
1545         struct icmp6_filter filt;
1546         int on;
1547         /* XXX: should be max MTU attached to the node */
1548         static char answer[1500];
1549
1550         syslog(LOG_DEBUG, "<%s> enter", __func__);
1551
1552         if (s == NULL) {
1553                 syslog(LOG_ERR, "<%s> internal error", __func__);
1554                 exit(1);
1555         }
1556         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1557             CMSG_SPACE(sizeof(int));
1558         rcvcmsgbuf = (char *)malloc(rcvcmsgbuflen);
1559         if (rcvcmsgbuf == NULL) {
1560                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1561                 exit(1);
1562         }
1563
1564         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1565             CMSG_SPACE(sizeof(int));
1566         sndcmsgbuf = (char *)malloc(sndcmsgbuflen);
1567         if (sndcmsgbuf == NULL) {
1568                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1569                 exit(1);
1570         }
1571
1572         if ((s->si_fd = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1573                 syslog(LOG_ERR, "<%s> socket: %s", __func__, strerror(errno));
1574                 exit(1);
1575         }
1576         /* specify to tell receiving interface */
1577         on = 1;
1578         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1579             sizeof(on)) < 0) {
1580                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s", __func__,
1581                     strerror(errno));
1582                 exit(1);
1583         }
1584         on = 1;
1585         /* specify to tell value of hoplimit field of received IP6 hdr */
1586         if (setsockopt(s->si_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1587                 sizeof(on)) < 0) {
1588                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s", __func__,
1589                     strerror(errno));
1590                 exit(1);
1591         }
1592         ICMP6_FILTER_SETBLOCKALL(&filt);
1593         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1594         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1595         if (mcastif != NULL)
1596                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1597
1598         if (setsockopt(s->si_fd, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1599             sizeof(filt)) < 0) {
1600                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1601                     __func__, strerror(errno));
1602                 exit(1);
1603         }
1604
1605         /* initialize msghdr for receiving packets */
1606         rcviov[0].iov_base = (caddr_t)answer;
1607         rcviov[0].iov_len = sizeof(answer);
1608         rcvmhdr.msg_name = (caddr_t)&rcvfrom;
1609         rcvmhdr.msg_namelen = sizeof(rcvfrom);
1610         rcvmhdr.msg_iov = rcviov;
1611         rcvmhdr.msg_iovlen = 1;
1612         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1613         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1614
1615         /* initialize msghdr for sending packets */
1616         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1617         sndmhdr.msg_iov = sndiov;
1618         sndmhdr.msg_iovlen = 1;
1619         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1620         sndmhdr.msg_controllen = sndcmsgbuflen;
1621
1622         return;
1623 }
1624
1625 /* open a routing socket to watch the routing table */
1626 static void
1627 rtsock_open(struct sockinfo *s)
1628 {
1629         if (s == NULL) {
1630                 syslog(LOG_ERR, "<%s> internal error", __func__);
1631                 exit(1);
1632         }
1633         if ((s->si_fd = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1634                 syslog(LOG_ERR,
1635                     "<%s> socket: %s", __func__, strerror(errno));
1636                 exit(1);
1637         }
1638 }
1639
1640 struct ifinfo *
1641 if_indextoifinfo(int idx)
1642 {
1643         struct ifinfo *ifi;
1644         char name0[IFNAMSIZ];
1645
1646         /* Check if the interface has a valid name or not. */
1647         if (if_indextoname(idx, name0) == NULL)
1648                 return (NULL);
1649
1650         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1651                 if (ifi->ifi_ifindex == idx)
1652                         return (ifi);
1653         }
1654
1655         if (ifi != NULL)
1656                 syslog(LOG_DEBUG, "<%s> ifi found (idx=%d)",
1657                     __func__, idx);
1658         else
1659                 syslog(LOG_DEBUG, "<%s> ifi not found (idx=%d)",
1660                     __func__, idx);
1661
1662         return (NULL);          /* search failed */
1663 }
1664
1665 void
1666 ra_output(struct ifinfo *ifi)
1667 {
1668         int i;
1669         struct cmsghdr *cm;
1670         struct in6_pktinfo *pi;
1671         struct soliciter *sol;
1672         struct rainfo *rai;
1673
1674         switch (ifi->ifi_state) {
1675         case IFI_STATE_CONFIGURED:
1676                 rai = ifi->ifi_rainfo;
1677                 break;
1678         case IFI_STATE_TRANSITIVE:
1679                 rai = ifi->ifi_rainfo_trans;
1680                 break;
1681         case IFI_STATE_UNCONFIGURED:
1682                 syslog(LOG_DEBUG, "<%s> %s is unconfigured.  "
1683                     "Skip sending RAs.",
1684                     __func__, ifi->ifi_ifname);
1685                 return;
1686         default:
1687                 rai = NULL;
1688         }
1689         if (rai == NULL) {
1690                 syslog(LOG_DEBUG, "<%s> rainfo is NULL on %s."
1691                     "Skip sending RAs.",
1692                     __func__, ifi->ifi_ifname);
1693                 return;
1694         }
1695         if (!(ifi->ifi_flags & IFF_UP)) {
1696                 syslog(LOG_DEBUG, "<%s> %s is not up.  "
1697                     "Skip sending RAs.",
1698                     __func__, ifi->ifi_ifname);
1699                 return;
1700         }
1701         /*
1702          * Check lifetime, ACCEPT_RTADV flag, and ip6.forwarding.
1703          *
1704          * (lifetime == 0) = output
1705          * (lifetime != 0 && (check_accept_rtadv()) = no output
1706          *
1707          * Basically, hosts MUST NOT send Router Advertisement
1708          * messages at any time (RFC 4861, Section 6.2.3). However, it
1709          * would sometimes be useful to allow hosts to advertise some
1710          * parameters such as prefix information and link MTU. Thus,
1711          * we allow hosts to invoke rtadvd only when router lifetime
1712          * (on every advertising interface) is explicitly set
1713          * zero. (see also the above section)
1714          */
1715         syslog(LOG_DEBUG,
1716             "<%s> check lifetime=%d, ACCEPT_RTADV=%d, ip6.forwarding=%d "
1717             "on %s", __func__,
1718             rai->rai_lifetime,
1719             check_accept_rtadv(ifi->ifi_ifindex),
1720             getinet6sysctl(IPV6CTL_FORWARDING),
1721             ifi->ifi_ifname);
1722
1723         if (rai->rai_lifetime != 0) {
1724                 if (getinet6sysctl(IPV6CTL_FORWARDING) == 0) {
1725                         syslog(LOG_ERR,
1726                             "non-zero lifetime RA "
1727                             "but net.inet6.ip6.forwarding=0.  "
1728                             "Ignored.");
1729                         return;
1730                 }
1731                 if (check_accept_rtadv(ifi->ifi_ifindex)) {
1732                         syslog(LOG_ERR,
1733                             "non-zero lifetime RA "
1734                             "on RA receiving interface %s."
1735                             "  Ignored.", ifi->ifi_ifname);
1736                         return;
1737                 }
1738         }
1739
1740         make_packet(rai);       /* XXX: inefficient */
1741
1742         sndmhdr.msg_name = (caddr_t)&sin6_linklocal_allnodes;
1743         sndmhdr.msg_iov[0].iov_base = (caddr_t)rai->rai_ra_data;
1744         sndmhdr.msg_iov[0].iov_len = rai->rai_ra_datalen;
1745
1746         cm = CMSG_FIRSTHDR(&sndmhdr);
1747         /* specify the outgoing interface */
1748         cm->cmsg_level = IPPROTO_IPV6;
1749         cm->cmsg_type = IPV6_PKTINFO;
1750         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1751         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1752         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1753         pi->ipi6_ifindex = ifi->ifi_ifindex;
1754
1755         /* specify the hop limit of the packet */
1756         {
1757                 int hoplimit = 255;
1758
1759                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1760                 cm->cmsg_level = IPPROTO_IPV6;
1761                 cm->cmsg_type = IPV6_HOPLIMIT;
1762                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1763                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1764         }
1765
1766         syslog(LOG_DEBUG,
1767             "<%s> send RA on %s, # of RS waitings = %d",
1768             __func__, ifi->ifi_ifname, ifi->ifi_rs_waitcount);
1769
1770         i = sendmsg(sock.si_fd, &sndmhdr, 0);
1771
1772         if (i < 0 || (size_t)i != rai->rai_ra_datalen)  {
1773                 if (i < 0) {
1774                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1775                             __func__, ifi->ifi_ifname,
1776                             strerror(errno));
1777                 }
1778         }
1779
1780         /*
1781          * unicast advertisements
1782          * XXX commented out.  reason: though spec does not forbit it, unicast
1783          * advert does not really help
1784          */
1785         while ((sol = TAILQ_FIRST(&rai->rai_soliciter)) != NULL) {
1786                 TAILQ_REMOVE(&rai->rai_soliciter, sol, sol_next);
1787                 free(sol);
1788         }
1789
1790         /* update timestamp */
1791         clock_gettime(CLOCK_MONOTONIC_FAST, &ifi->ifi_ra_lastsent);
1792
1793         /* update counter */
1794         ifi->ifi_rs_waitcount = 0;
1795         ifi->ifi_raoutput++;
1796
1797         switch (ifi->ifi_state) {
1798         case IFI_STATE_CONFIGURED:
1799                 if (ifi->ifi_burstcount > 0)
1800                         ifi->ifi_burstcount--;
1801                 break;
1802         case IFI_STATE_TRANSITIVE:
1803                 ifi->ifi_burstcount--;
1804                 if (ifi->ifi_burstcount == 0) {
1805                         if (ifi->ifi_rainfo == ifi->ifi_rainfo_trans) {
1806                                 /* Initial burst finished. */
1807                                 if (ifi->ifi_rainfo_trans != NULL)
1808                                         ifi->ifi_rainfo_trans = NULL;
1809                         }
1810
1811                         /* Remove burst RA information */
1812                         if (ifi->ifi_rainfo_trans != NULL) {
1813                                 rm_rainfo(ifi->ifi_rainfo_trans);
1814                                 ifi->ifi_rainfo_trans = NULL;
1815                         }
1816
1817                         if (ifi->ifi_rainfo != NULL) {
1818                                 /*
1819                                  * TRANSITIVE -> CONFIGURED
1820                                  *
1821                                  * After initial burst or transition from
1822                                  * one configuration to another,
1823                                  * ifi_rainfo always points to the next RA
1824                                  * information.
1825                                  */
1826                                 ifi->ifi_state = IFI_STATE_CONFIGURED;
1827                                 syslog(LOG_DEBUG,
1828                                     "<%s> ifname=%s marked as "
1829                                     "CONFIGURED.", __func__,
1830                                     ifi->ifi_ifname);
1831                         } else {
1832                                 /*
1833                                  * TRANSITIVE -> UNCONFIGURED
1834                                  *
1835                                  * If ifi_rainfo points to NULL, this
1836                                  * interface is shutting down.
1837                                  *
1838                                  */
1839                                 int error;
1840
1841                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
1842                                 syslog(LOG_DEBUG,
1843                                     "<%s> ifname=%s marked as "
1844                                     "UNCONFIGURED.", __func__,
1845                                     ifi->ifi_ifname);
1846                                 error = sock_mc_leave(&sock,
1847                                     ifi->ifi_ifindex);
1848                                 if (error)
1849                                         exit(1);
1850                         }
1851                 }
1852                 break;
1853         }
1854 }
1855
1856 /* process RA timer */
1857 struct rtadvd_timer *
1858 ra_timeout(void *arg)
1859 {
1860         struct ifinfo *ifi;
1861
1862         ifi = (struct ifinfo *)arg;
1863         syslog(LOG_DEBUG, "<%s> RA timer on %s is expired",
1864             __func__, ifi->ifi_ifname);
1865
1866         ra_output(ifi);
1867
1868         return (ifi->ifi_ra_timer);
1869 }
1870
1871 /* update RA timer */
1872 void
1873 ra_timer_update(void *arg, struct timespec *tm)
1874 {
1875         uint16_t interval;
1876         struct rainfo *rai;
1877         struct ifinfo *ifi;
1878
1879         ifi = (struct ifinfo *)arg;
1880         rai = ifi->ifi_rainfo;
1881         interval = 0;
1882
1883         switch (ifi->ifi_state) {
1884         case IFI_STATE_UNCONFIGURED:
1885                 return;
1886                 break;
1887         case IFI_STATE_CONFIGURED:
1888                 /*
1889                  * Whenever a multicast advertisement is sent from
1890                  * an interface, the timer is reset to a
1891                  * uniformly-distributed random value between the
1892                  * interface's configured MinRtrAdvInterval and
1893                  * MaxRtrAdvInterval (RFC4861 6.2.4).
1894                  */
1895                 interval = rai->rai_mininterval;
1896 #ifdef HAVE_ARC4RANDOM
1897                 interval += arc4random_uniform(rai->rai_maxinterval -
1898                     rai->rai_mininterval);
1899 #else
1900                 interval += random() % (rai->rai_maxinterval -
1901                     rai->rai_mininterval);
1902 #endif
1903                 break;
1904         case IFI_STATE_TRANSITIVE:
1905                 /*
1906                  * For the first few advertisements (up to
1907                  * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1908                  * interval is greater than
1909                  * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1910                  * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.  (RFC
1911                  * 4861 6.2.4)
1912                  *
1913                  * In such cases, the router SHOULD transmit one or more
1914                  * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1915                  * multicast Router Advertisements on the interface with a
1916                  * Router Lifetime field of zero.  (RFC 4861 6.2.5)
1917                  */
1918                 interval = ifi->ifi_burstinterval;
1919                 break;
1920         }
1921
1922         tm->tv_sec = interval;
1923         tm->tv_nsec = 0;
1924
1925         syslog(LOG_DEBUG,
1926             "<%s> RA timer on %s is set to %ld:%ld",
1927             __func__, ifi->ifi_ifname,
1928             (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1929
1930         return;
1931 }