usr.sbin/rtadvd/rtadvd.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: rtadvd.c,v 1.82 2003/08/05 12:34:23 itojun Exp $ */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * Copyright (C) 2011 Hiroki Sato <hrs@FreeBSD.org>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/socket.h>
  37 #include <sys/uio.h>
  38 #include <sys/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 pid, 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         pid = getpid();
 280         pidfile_write(pfh);
 281
 282         set[PFD_RAWSOCK].fd = sock.si_fd;
 283         set[PFD_RAWSOCK].events = POLLIN;
 284         if (sflag == 0) {
 285                 rtsock_open(&rtsock);
 286                 set[PFD_RTSOCK].fd = rtsock.si_fd;
 287                 set[PFD_RTSOCK].events = POLLIN;
 288         } else
 289                 set[PFD_RTSOCK].fd = -1;
 290         set[PFD_CSOCK].fd = ctrlsock.si_fd;
 291         set[PFD_CSOCK].events = POLLIN;
 292         signal(SIGTERM, set_do_shutdown);
 293         signal(SIGINT, set_do_shutdown);
 294         signal(SIGHUP, set_do_reload);
 295
 296         error = csock_listen(&ctrlsock);
 297         if (error) {
 298                 syslog(LOG_ERR, "cannot listen control socket: %s",
 299                     strerror(errno));
 300                 exit(1);
 301         }
 302
 303         /* load configuration file */
 304         set_do_reload(0);
 305
 306         while (1) {
 307                 if (is_do_shutdown())
 308                         rtadvd_shutdown();
 309
 310                 if (is_do_reload()) {
 311                         loadconfig_ifname(reload_ifname());
 312                         if (reload_ifname() == NULL)
 313                                 syslog(LOG_INFO,
 314                                     "configuration file reloaded.");
 315                         else
 316                                 syslog(LOG_INFO,
 317                                     "configuration file for %s reloaded.",
 318                                     reload_ifname());
 319                         reset_do_reload();
 320                 }
 321
 322                 /* timeout handler update for active interfaces */
 323                 rtadvd_update_timeout_handler();
 324
 325                 /* timer expiration check and reset the timer */
 326                 timeout = rtadvd_check_timer();
 327
 328                 if (timeout != NULL) {
 329                         syslog(LOG_DEBUG,
 330                             "<%s> set timer to %ld:%ld. waiting for "
 331                             "inputs or timeout", __func__,
 332                             (long int)timeout->tv_sec,
 333                             (long int)timeout->tv_nsec / 1000);
 334                 } else {
 335                         syslog(LOG_DEBUG,
 336                             "<%s> there's no timer. waiting for inputs",
 337                             __func__);
 338                 }
 339                 if ((i = poll(set, sizeof(set)/sizeof(set[0]),
 340                             timeout ? (timeout->tv_sec * 1000 +
 341                                 timeout->tv_nsec / 1000 / 1000) : INFTIM)) < 0) {
 342
 343                         /* EINTR would occur if a signal was delivered */
 344                         if (errno != EINTR)
 345                                 syslog(LOG_ERR, "poll() failed: %s",
 346                                     strerror(errno));
 347                         continue;
 348                 }
 349                 if (i == 0)     /* timeout */
 350                         continue;
 351                 if (rtsock.si_fd != -1 && set[PFD_RTSOCK].revents & POLLIN)
 352                         rtmsg_input(&rtsock);
 353
 354                 if (set[PFD_RAWSOCK].revents & POLLIN)
 355                         rtadvd_input(&sock);
 356
 357                 if (set[PFD_CSOCK].revents & POLLIN) {
 358                         int fd;
 359
 360                         fd = csock_accept(&ctrlsock);
 361                         if (fd == -1)
 362                                 syslog(LOG_ERR,
 363                                     "cannot accept() control socket: %s",
 364                                     strerror(errno));
 365                         else {
 366                                 cm_handler_server(fd);
 367                                 close(fd);
 368                         }
 369                 }
 370         }
 371         exit(0);                /* NOTREACHED */
 372 }
 373
 374 static void
 375 rtadvd_shutdown(void)
 376 {
 377         struct ifinfo *ifi;
 378         struct rainfo *rai;
 379         struct rdnss *rdn;
 380         struct dnssl *dns;
 381
 382         if (wait_shutdown) {
 383                 syslog(LOG_INFO,
 384                     "waiting expiration of the all RA timers.");
 385
 386                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 387                         /*
 388                          * Ignore !IFF_UP interfaces in waiting for shutdown.
 389                          */
 390                         if (!(ifi->ifi_flags & IFF_UP) &&
 391                             ifi->ifi_ra_timer != NULL) {
 392                                 ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 393                                 rtadvd_remove_timer(ifi->ifi_ra_timer);
 394                                 ifi->ifi_ra_timer = NULL;
 395                                 syslog(LOG_DEBUG, "<%s> %s(idx=%d) is down. "
 396                                     "Timer removed and marked as UNCONFIGURED.",
 397                                      __func__, ifi->ifi_ifname,
 398                                     ifi->ifi_ifindex);
 399                         }
 400                 }
 401                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 402                         if (ifi->ifi_ra_timer != NULL)
 403                                 break;
 404                 }
 405                 if (ifi == NULL) {
 406                         syslog(LOG_NOTICE, "gracefully terminated.");
 407                         exit(0);
 408                 }
 409
 410                 sleep(1);
 411                 return;
 412         }
 413
 414         syslog(LOG_DEBUG, "<%s> cease to be an advertising router",
 415             __func__);
 416
 417         wait_shutdown = 1;
 418
 419         TAILQ_FOREACH(rai, &railist, rai_next) {
 420                 rai->rai_lifetime = 0;
 421                 TAILQ_FOREACH(rdn, &rai->rai_rdnss, rd_next)
 422                         rdn->rd_ltime = 0;
 423                 TAILQ_FOREACH(dns, &rai->rai_dnssl, dn_next)
 424                         dns->dn_ltime = 0;
 425         }
 426         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 427                 if (!ifi->ifi_persist)
 428                         continue;
 429                 if (ifi->ifi_state == IFI_STATE_UNCONFIGURED)
 430                         continue;
 431                 if (ifi->ifi_ra_timer == NULL)
 432                         continue;
 433                 if (ifi->ifi_ra_lastsent.tv_sec == 0 &&
 434                     ifi->ifi_ra_lastsent.tv_nsec == 0 &&
 435                     ifi->ifi_ra_timer != NULL) {
 436                         /*
 437                          * When RA configured but never sent,
 438                          * ignore the IF immediately.
 439                          */
 440                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 441                         ifi->ifi_ra_timer = NULL;
 442                         ifi->ifi_state = IFI_STATE_UNCONFIGURED;
 443                         continue;
 444                 }
 445
 446                 ifi->ifi_state = IFI_STATE_TRANSITIVE;
 447
 448                 /* Mark as the shut-down state. */
 449                 ifi->ifi_rainfo_trans = ifi->ifi_rainfo;
 450                 ifi->ifi_rainfo = NULL;
 451
 452                 ifi->ifi_burstcount = MAX_FINAL_RTR_ADVERTISEMENTS;
 453                 ifi->ifi_burstinterval = MIN_DELAY_BETWEEN_RAS;
 454
 455                 ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 456                 rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 457                     ifi->ifi_ra_timer);
 458         }
 459         syslog(LOG_NOTICE, "final RA transmission started.");
 460
 461         pidfile_remove(pfh);
 462         csock_close(&ctrlsock);
 463 }
 464
 465 static void
 466 rtmsg_input(struct sockinfo *s)
 467 {
 468         int n, type, ifindex = 0, plen;
 469         size_t len;
 470         char msg[2048], *next, *lim;
 471         char ifname[IFNAMSIZ];
 472         struct if_announcemsghdr *ifan;
 473         struct rt_msghdr *rtm;
 474         struct prefix *pfx;
 475         struct rainfo *rai;
 476         struct in6_addr *addr;
 477         struct ifinfo *ifi;
 478         char addrbuf[INET6_ADDRSTRLEN];
 479         int prefixchange = 0;
 480
 481         if (s == NULL) {
 482                 syslog(LOG_ERR, "<%s> internal error", __func__);
 483                 exit(1);
 484         }
 485         n = read(s->si_fd, msg, sizeof(msg));
 486         rtm = (struct rt_msghdr *)msg;
 487         syslog(LOG_DEBUG, "<%s> received a routing message "
 488             "(type = %d, len = %d)", __func__, rtm->rtm_type, n);
 489
 490         if (n > rtm->rtm_msglen) {
 491                 /*
 492                  * This usually won't happen for messages received on
 493                  * a routing socket.
 494                  */
 495                 syslog(LOG_DEBUG,
 496                     "<%s> received data length is larger than "
 497                     "1st routing message len. multiple messages? "
 498                     "read %d bytes, but 1st msg len = %d",
 499                     __func__, n, rtm->rtm_msglen);
 500 #if 0
 501                 /* adjust length */
 502                 n = rtm->rtm_msglen;
 503 #endif
 504         }
 505
 506         lim = msg + n;
 507         for (next = msg; next < lim; next += len) {
 508                 int oldifflags;
 509
 510                 next = get_next_msg(next, lim, 0, &len,
 511                     RTADV_TYPE2BITMASK(RTM_ADD) |
 512                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 513                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 514                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 515                     RTADV_TYPE2BITMASK(RTM_IFINFO) |
 516                     RTADV_TYPE2BITMASK(RTM_IFANNOUNCE));
 517                 if (len == 0)
 518                         break;
 519                 type = ((struct rt_msghdr *)next)->rtm_type;
 520                 switch (type) {
 521                 case RTM_ADD:
 522                 case RTM_DELETE:
 523                         ifindex = get_rtm_ifindex(next);
 524                         break;
 525                 case RTM_NEWADDR:
 526                 case RTM_DELADDR:
 527                         ifindex = (int)((struct ifa_msghdr *)next)->ifam_index;
 528                         break;
 529                 case RTM_IFINFO:
 530                         ifindex = (int)((struct if_msghdr *)next)->ifm_index;
 531                         break;
 532                 case RTM_IFANNOUNCE:
 533                         ifan = (struct if_announcemsghdr *)next;
 534                         switch (ifan->ifan_what) {
 535                         case IFAN_ARRIVAL:
 536                         case IFAN_DEPARTURE:
 537                                 break;
 538                         default:
 539                                 syslog(LOG_DEBUG,
 540                                     "<%s:%d> unknown ifan msg (ifan_what=%d)",
 541                                    __func__, __LINE__, ifan->ifan_what);
 542                                 continue;
 543                         }
 544
 545                         syslog(LOG_DEBUG, "<%s>: if_announcemsg (idx=%d:%d)",
 546                                __func__, ifan->ifan_index, ifan->ifan_what);
 547                         switch (ifan->ifan_what) {
 548                         case IFAN_ARRIVAL:
 549                                 syslog(LOG_NOTICE,
 550                                     "interface added (idx=%d)",
 551                                     ifan->ifan_index);
 552                                 update_ifinfo(&ifilist, ifan->ifan_index);
 553                                 loadconfig_index(ifan->ifan_index);
 554                                 break;
 555                         case IFAN_DEPARTURE:
 556                                 syslog(LOG_NOTICE,
 557                                     "interface removed (idx=%d)",
 558                                     ifan->ifan_index);
 559                                 rm_ifinfo_index(ifan->ifan_index);
 560
 561                                 /* Clear ifi_ifindex */
 562                                 TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
 563                                         if (ifi->ifi_ifindex
 564                                             == ifan->ifan_index) {
 565                                                 ifi->ifi_ifindex = 0;
 566                                                 break;
 567                                         }
 568                                 }
 569                                 update_ifinfo(&ifilist, ifan->ifan_index);
 570                                 break;
 571                         }
 572                         continue;
 573                 default:
 574                         /* should not reach here */
 575                         syslog(LOG_DEBUG,
 576                                "<%s:%d> unknown rtmsg %d on %s",
 577                                __func__, __LINE__, type,
 578                                if_indextoname(ifindex, ifname));
 579                         continue;
 580                 }
 581                 ifi = if_indextoifinfo(ifindex);
 582                 if (ifi == NULL) {
 583                         syslog(LOG_DEBUG,
 584                             "<%s> ifinfo not found for idx=%d.  Why?",
 585                             __func__, ifindex);
 586                         continue;
 587                 }
 588                 rai = ifi->ifi_rainfo;
 589                 if (rai == NULL) {
 590                         syslog(LOG_DEBUG,
 591                             "<%s> route changed on "
 592                             "non advertising interface(%s)",
 593                             __func__, ifi->ifi_ifname);
 594                         continue;
 595                 }
 596
 597                 oldifflags = ifi->ifi_flags;
 598                 /* init ifflags because it may have changed */
 599                 update_ifinfo(&ifilist, ifindex);
 600
 601                 switch (type) {
 602                 case RTM_ADD:
 603                         if (sflag)
 604                                 break;  /* we aren't interested in prefixes  */
 605
 606                         addr = get_addr(msg);
 607                         plen = get_prefixlen(msg);
 608                         /* sanity check for plen */
 609                         /* as RFC2373, prefixlen is at least 4 */
 610                         if (plen < 4 || plen > 127) {
 611                                 syslog(LOG_INFO, "<%s> new interface route's"
 612                                     "plen %d is invalid for a prefix",
 613                                     __func__, plen);
 614                                 break;
 615                         }
 616                         pfx = find_prefix(rai, addr, plen);
 617                         if (pfx) {
 618                                 if (pfx->pfx_timer) {
 619                                         /*
 620                                          * If the prefix has been invalidated,
 621                                          * make it available again.
 622                                          */
 623                                         update_prefix(pfx);
 624                                         prefixchange = 1;
 625                                 } else
 626                                         syslog(LOG_DEBUG,
 627                                             "<%s> new prefix(%s/%d) "
 628                                             "added on %s, "
 629                                             "but it was already in list",
 630                                             __func__,
 631                                             inet_ntop(AF_INET6, addr,
 632                                                 (char *)addrbuf,
 633                                                 sizeof(addrbuf)),
 634                                             plen, ifi->ifi_ifname);
 635                                 break;
 636                         }
 637                         make_prefix(rai, ifindex, addr, plen);
 638                         prefixchange = 1;
 639                         break;
 640                 case RTM_DELETE:
 641                         if (sflag)
 642                                 break;
 643
 644                         addr = get_addr(msg);
 645                         plen = get_prefixlen(msg);
 646                         /* sanity check for plen */
 647                         /* as RFC2373, prefixlen is at least 4 */
 648                         if (plen < 4 || plen > 127) {
 649                                 syslog(LOG_INFO,
 650                                     "<%s> deleted interface route's "
 651                                     "plen %d is invalid for a prefix",
 652                                     __func__, plen);
 653                                 break;
 654                         }
 655                         pfx = find_prefix(rai, addr, plen);
 656                         if (pfx == NULL) {
 657                                 syslog(LOG_DEBUG,
 658                                     "<%s> prefix(%s/%d) was deleted on %s, "
 659                                     "but it was not in list",
 660                                     __func__, inet_ntop(AF_INET6, addr,
 661                                         (char *)addrbuf, sizeof(addrbuf)),
 662                                         plen, ifi->ifi_ifname);
 663                                 break;
 664                         }
 665                         invalidate_prefix(pfx);
 666                         prefixchange = 1;
 667                         break;
 668                 case RTM_NEWADDR:
 669                 case RTM_DELADDR:
 670                 case RTM_IFINFO:
 671                         break;
 672                 default:
 673                         /* should not reach here */
 674                         syslog(LOG_DEBUG,
 675                             "<%s:%d> unknown rtmsg %d on %s",
 676                             __func__, __LINE__, type,
 677                             if_indextoname(ifindex, ifname));
 678                         return;
 679                 }
 680
 681                 /* check if an interface flag is changed */
 682                 if ((oldifflags & IFF_UP) && /* UP to DOWN */
 683                     !(ifi->ifi_flags & IFF_UP)) {
 684                         syslog(LOG_NOTICE,
 685                             "<interface %s becomes down. stop timer.",
 686                             ifi->ifi_ifname);
 687                         rtadvd_remove_timer(ifi->ifi_ra_timer);
 688                         ifi->ifi_ra_timer = NULL;
 689                 } else if (!(oldifflags & IFF_UP) && /* DOWN to UP */
 690                     (ifi->ifi_flags & IFF_UP)) {
 691                         syslog(LOG_NOTICE,
 692                             "interface %s becomes up. restart timer.",
 693                             ifi->ifi_ifname);
 694
 695                         ifi->ifi_state = IFI_STATE_TRANSITIVE;
 696                         ifi->ifi_burstcount =
 697                             MAX_INITIAL_RTR_ADVERTISEMENTS;
 698                         ifi->ifi_burstinterval =
 699                             MAX_INITIAL_RTR_ADVERT_INTERVAL;
 700
 701                         ifi->ifi_ra_timer = rtadvd_add_timer(ra_timeout,
 702                             ra_timer_update, ifi, ifi);
 703                         ra_timer_update(ifi, &ifi->ifi_ra_timer->rat_tm);
 704                         rtadvd_set_timer(&ifi->ifi_ra_timer->rat_tm,
 705                             ifi->ifi_ra_timer);
 706                 } else if (prefixchange &&
 707                     (ifi->ifi_flags & IFF_UP)) {
 708                         /*
 709                          * An advertised prefix has been added or invalidated.
 710                          * Will notice the change in a short delay.
 711                          */
 712                         set_short_delay(ifi);
 713                 }
 714         }
 715
 716         return;
 717 }
 718
 719 void
 720 rtadvd_input(struct sockinfo *s)
 721 {
 722         ssize_t i;
 723         int *hlimp = NULL;
 724 #ifdef OLDRAWSOCKET
 725         struct ip6_hdr *ip;
 726 #endif
 727         struct icmp6_hdr *icp;
 728         int ifindex = 0;
 729         struct cmsghdr *cm;
 730         struct in6_pktinfo *pi = NULL;
 731         char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 732         struct in6_addr dst = in6addr_any;
 733         struct ifinfo *ifi;
 734
 735         syslog(LOG_DEBUG, "<%s> enter", __func__);
 736
 737         if (s == NULL) {
 738                 syslog(LOG_ERR, "<%s> internal error", __func__);
 739                 exit(1);
 740         }
 741         /*
 742          * Get message. We reset msg_controllen since the field could
 743          * be modified if we had received a message before setting
 744          * receive options.
 745          */
 746         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 747         if ((i = recvmsg(s->si_fd, &rcvmhdr, 0)) < 0)
 748                 return;
 749
 750         /* extract optional information via Advanced API */
 751         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 752              cm;
 753              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 754                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 755                     cm->cmsg_type == IPV6_PKTINFO &&
 756                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 757                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 758                         ifindex = pi->ipi6_ifindex;
 759                         dst = pi->ipi6_addr;
 760                 }
 761                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 762                     cm->cmsg_type == IPV6_HOPLIMIT &&
 763                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 764                         hlimp = (int *)CMSG_DATA(cm);
 765         }
 766         if (ifindex == 0) {
 767                 syslog(LOG_ERR, "failed to get receiving interface");
 768                 return;
 769         }
 770         if (hlimp == NULL) {
 771                 syslog(LOG_ERR, "failed to get receiving hop limit");
 772                 return;
 773         }
 774
 775         /*
 776          * If we happen to receive data on an interface which is now gone
 777          * or down, just discard the data.
 778          */
 779         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 780         if (ifi == NULL || !(ifi->ifi_flags & IFF_UP)) {
 781                 syslog(LOG_INFO,
 782                     "<%s> received data on a disabled interface (%s)",
 783                     __func__,
 784                     (ifi == NULL) ? "[gone]" : ifi->ifi_ifname);
 785                 return;
 786         }
 787
 788 #ifdef OLDRAWSOCKET
 789         if ((size_t)i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 790                 syslog(LOG_ERR,
 791                     "packet size(%d) is too short", i);
 792                 return;
 793         }
 794
 795         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 796         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 797 #else
 798         if ((size_t)i < sizeof(struct icmp6_hdr)) {
 799                 syslog(LOG_ERR, "packet size(%zd) is too short", i);
 800                 return;
 801         }
 802
 803         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 804 #endif
 805
 806         switch (icp->icmp6_type) {
 807         case ND_ROUTER_SOLICIT:
 808                 /*
 809                  * Message verification - RFC 4861 6.1.1
 810                  * XXX: these checks must be done in the kernel as well,
 811                  *      but we can't completely rely on them.
 812                  */
 813                 if (*hlimp != 255) {
 814                         syslog(LOG_NOTICE,
 815                             "RS with invalid hop limit(%d) "
 816                             "received from %s on %s",
 817                             *hlimp,
 818                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 819                             sizeof(ntopbuf)),
 820                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 821                         return;
 822                 }
 823                 if (icp->icmp6_code) {
 824                         syslog(LOG_NOTICE,
 825                             "RS with invalid ICMP6 code(%d) "
 826                             "received from %s on %s",
 827                             icp->icmp6_code,
 828                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 829                             sizeof(ntopbuf)),
 830                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 831                         return;
 832                 }
 833                 if ((size_t)i < sizeof(struct nd_router_solicit)) {
 834                         syslog(LOG_NOTICE,
 835                             "RS from %s on %s does not have enough "
 836                             "length (len = %zd)",
 837                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 838                             sizeof(ntopbuf)),
 839                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 840                         return;
 841                 }
 842                 rs_input(i, (struct nd_router_solicit *)icp, pi, &rcvfrom);
 843                 break;
 844         case ND_ROUTER_ADVERT:
 845                 /*
 846                  * Message verification - RFC 4861 6.1.2
 847                  * XXX: there's the same dilemma as above...
 848                  */
 849                 if (!IN6_IS_ADDR_LINKLOCAL(&rcvfrom.sin6_addr)) {
 850                         syslog(LOG_NOTICE,
 851                             "RA with non-linklocal source address "
 852                             "received from %s on %s",
 853                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr,
 854                             ntopbuf, sizeof(ntopbuf)),
 855                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 856                         return;
 857                 }
 858                 if (*hlimp != 255) {
 859                         syslog(LOG_NOTICE,
 860                             "RA with invalid hop limit(%d) "
 861                             "received from %s on %s",
 862                             *hlimp,
 863                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 864                             sizeof(ntopbuf)),
 865                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 866                         return;
 867                 }
 868                 if (icp->icmp6_code) {
 869                         syslog(LOG_NOTICE,
 870                             "RA with invalid ICMP6 code(%d) "
 871                             "received from %s on %s",
 872                             icp->icmp6_code,
 873                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 874                             sizeof(ntopbuf)),
 875                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 876                         return;
 877                 }
 878                 if ((size_t)i < sizeof(struct nd_router_advert)) {
 879                         syslog(LOG_NOTICE,
 880                             "RA from %s on %s does not have enough "
 881                             "length (len = %zd)",
 882                             inet_ntop(AF_INET6, &rcvfrom.sin6_addr, ntopbuf,
 883                             sizeof(ntopbuf)),
 884                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 885                         return;
 886                 }
 887                 ra_input(i, (struct nd_router_advert *)icp, pi, &rcvfrom);
 888                 break;
 889         case ICMP6_ROUTER_RENUMBERING:
 890                 if (mcastif == NULL) {
 891                         syslog(LOG_ERR, "received a router renumbering "
 892                             "message, but not allowed to be accepted");
 893                         break;
 894                 }
 895                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &rcvfrom,
 896                     &dst);
 897                 break;
 898         default:
 899                 /*
 900                  * Note that this case is POSSIBLE, especially just
 901                  * after invocation of the daemon. This is because we
 902                  * could receive message after opening the socket and
 903                  * before setting ICMP6 type filter(see sock_open()).
 904                  */
 905                 syslog(LOG_ERR, "invalid icmp type(%d)", icp->icmp6_type);
 906                 return;
 907         }
 908
 909         return;
 910 }
 911
 912 static void
 913 rs_input(int len, struct nd_router_solicit *rs,
 914          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 915 {
 916         char ntopbuf[INET6_ADDRSTRLEN];
 917         char ifnamebuf[IFNAMSIZ];
 918         union nd_opt ndopts;
 919         struct rainfo *rai;
 920         struct ifinfo *ifi;
 921         struct soliciter *sol;
 922
 923         syslog(LOG_DEBUG,
 924             "<%s> RS received from %s on %s",
 925             __func__,
 926             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
 927             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 928
 929         /* ND option check */
 930         memset(&ndopts, 0, sizeof(ndopts));
 931         TAILQ_INIT(&ndopts.opt_list);
 932         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 933                         len - sizeof(struct nd_router_solicit),
 934                         &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 935                 syslog(LOG_INFO,
 936                     "<%s> ND option check failed for an RS from %s on %s",
 937                     __func__,
 938                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
 939                         sizeof(ntopbuf)),
 940                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 941                 return;
 942         }
 943
 944         /*
 945          * If the IP source address is the unspecified address, there
 946          * must be no source link-layer address option in the message.
 947          * (RFC 4861 6.1.1)
 948          */
 949         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 950             ndopts.opt_src_lladdr) {
 951                 syslog(LOG_INFO,
 952                     "<%s> RS from unspecified src on %s has a link-layer"
 953                     " address option",
 954                     __func__, if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 955                 goto done;
 956         }
 957
 958         ifi = if_indextoifinfo(pi->ipi6_ifindex);
 959         if (ifi == NULL) {
 960                 syslog(LOG_INFO,
 961                     "<%s> if (idx=%d) not found.  Why?",
 962                     __func__, pi->ipi6_ifindex);
 963                 goto done;
 964         }
 965         rai = ifi->ifi_rainfo;
 966         if (rai == NULL) {
 967                 syslog(LOG_INFO,
 968                        "<%s> RS received on non advertising interface(%s)",
 969                        __func__,
 970                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 971                 goto done;
 972         }
 973
 974         rai->rai_ifinfo->ifi_rsinput++;
 975
 976         /*
 977          * Decide whether to send RA according to the rate-limit
 978          * consideration.
 979          */
 980
 981         /* record sockaddr waiting for RA, if possible */
 982         sol = (struct soliciter *)malloc(sizeof(*sol));
 983         if (sol) {
 984                 sol->sol_addr = *from;
 985                 /* XXX RFC 2553 need clarification on flowinfo */
 986                 sol->sol_addr.sin6_flowinfo = 0;
 987                 TAILQ_INSERT_TAIL(&rai->rai_soliciter, sol, sol_next);
 988         }
 989
 990         /*
 991          * If there is already a waiting RS packet, don't
 992          * update the timer.
 993          */
 994         if (ifi->ifi_rs_waitcount++)
 995                 goto done;
 996
 997         set_short_delay(ifi);
 998
 999   done:
1000         free_ndopts(&ndopts);
1001         return;
1002 }
1003
1004 static void
1005 set_short_delay(struct ifinfo *ifi)
1006 {
1007         long delay;     /* must not be greater than 1000000 */
1008         struct timespec interval, now, min_delay, tm_tmp, *rest;
1009
1010         if (ifi->ifi_ra_timer == NULL)
1011                 return;
1012         /*
1013          * Compute a random delay. If the computed value
1014          * corresponds to a time later than the time the next
1015          * multicast RA is scheduled to be sent, ignore the random
1016          * delay and send the advertisement at the
1017          * already-scheduled time. RFC 4861 6.2.6
1018          */
1019 #ifdef HAVE_ARC4RANDOM
1020         delay = arc4random_uniform(MAX_RA_DELAY_TIME);
1021 #else
1022         delay = random() % MAX_RA_DELAY_TIME;
1023 #endif
1024         interval.tv_sec = 0;
1025         interval.tv_nsec = delay * 1000;
1026         rest = rtadvd_timer_rest(ifi->ifi_ra_timer);
1027         if (TS_CMP(rest, &interval, <)) {
1028                 syslog(LOG_DEBUG, "<%s> random delay is larger than "
1029                     "the rest of the current timer", __func__);
1030                 interval = *rest;
1031         }
1032
1033         /*
1034          * If we sent a multicast Router Advertisement within
1035          * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
1036          * the advertisement to be sent at a time corresponding to
1037          * MIN_DELAY_BETWEEN_RAS plus the random value after the
1038          * previous advertisement was sent.
1039          */
1040         clock_gettime(CLOCK_MONOTONIC_FAST, &now);
1041         TS_SUB(&now, &ifi->ifi_ra_lastsent, &tm_tmp);
1042         min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
1043         min_delay.tv_nsec = 0;
1044         if (TS_CMP(&tm_tmp, &min_delay, <)) {
1045                 TS_SUB(&min_delay, &tm_tmp, &min_delay);
1046                 TS_ADD(&min_delay, &interval, &interval);
1047         }
1048         rtadvd_set_timer(&interval, ifi->ifi_ra_timer);
1049 }
1050
1051 static int
1052 check_accept_rtadv(int idx)
1053 {
1054         struct ifinfo *ifi;
1055
1056         TAILQ_FOREACH(ifi, &ifilist, ifi_next) {
1057                 if (ifi->ifi_ifindex == idx)
1058                         break;
1059         }
1060         if (ifi == NULL) {
1061                 syslog(LOG_DEBUG,
1062                     "<%s> if (idx=%d) not found.  Why?",
1063                     __func__, idx);
1064                 return (0);
1065         }
1066 #if (__FreeBSD_version < 900000)
1067         /*
1068          * RA_RECV: !ip6.forwarding && ip6.accept_rtadv
1069          * RA_SEND: ip6.forwarding
1070          */
1071         return ((getinet6sysctl(IPV6CTL_FORWARDING) == 0) &&
1072             (getinet6sysctl(IPV6CTL_ACCEPT_RTADV) == 1));
1073 #else
1074         /*
1075          * RA_RECV: ND6_IFF_ACCEPT_RTADV
1076          * RA_SEND: ip6.forwarding
1077          */
1078         if (update_ifinfo_nd_flags(ifi) != 0) {
1079                 syslog(LOG_ERR, "cannot get nd6 flags (idx=%d)", idx);
1080                 return (0);
1081         }
1082
1083         return (ifi->ifi_nd_flags & ND6_IFF_ACCEPT_RTADV);
1084 #endif
1085 }
1086
1087 static void
1088 ra_input(int len, struct nd_router_advert *nra,
1089          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
1090 {
1091         struct rainfo *rai;
1092         struct ifinfo *ifi;
1093         char ntopbuf[INET6_ADDRSTRLEN];
1094         char ifnamebuf[IFNAMSIZ];
1095         union nd_opt ndopts;
1096         const char *on_off[] = {"OFF", "ON"};
1097         uint32_t reachabletime, retranstimer, mtu;
1098         int inconsistent = 0;
1099         int error;
1100
1101         syslog(LOG_DEBUG, "<%s> RA received from %s on %s", __func__,
1102             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf, sizeof(ntopbuf)),
1103             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
1104
1105         /* ND option check */
1106         memset(&ndopts, 0, sizeof(ndopts));
1107         TAILQ_INIT(&ndopts.opt_list);
1108         error = nd6_options((struct nd_opt_hdr *)(nra + 1),
1109             len - sizeof(struct nd_router_advert), &ndopts,
1110             NDOPT_FLAG_SRCLINKADDR | NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU |
1111             NDOPT_FLAG_RDNSS | NDOPT_FLAG_DNSSL);
1112         if (error) {
1113                 syslog(LOG_INFO,
1114                     "<%s> ND option check failed for an RA from %s on %s",
1115                     __func__,
1116                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1117                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1118                         ifnamebuf));
1119                 return;
1120         }
1121
1122         /*
1123          * RA consistency check according to RFC 4861 6.2.7
1124          */
1125         ifi = if_indextoifinfo(pi->ipi6_ifindex);
1126         if (ifi->ifi_rainfo == NULL) {
1127                 syslog(LOG_INFO,
1128                     "<%s> received RA from %s on non-advertising"
1129                     " interface(%s)",
1130                     __func__,
1131                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1132                         sizeof(ntopbuf)), if_indextoname(pi->ipi6_ifindex,
1133                         ifnamebuf));
1134                 goto done;
1135         }
1136         rai = ifi->ifi_rainfo;
1137         ifi->ifi_rainput++;
1138         syslog(LOG_DEBUG, "<%s> ifi->ifi_rainput = %" PRIu64, __func__,
1139             ifi->ifi_rainput);
1140
1141         /* Cur Hop Limit value */
1142         if (nra->nd_ra_curhoplimit && rai->rai_hoplimit &&
1143             nra->nd_ra_curhoplimit != rai->rai_hoplimit) {
1144                 syslog(LOG_NOTICE,
1145                     "CurHopLimit inconsistent on %s:"
1146                     " %d from %s, %d from us",
1147                     ifi->ifi_ifname, nra->nd_ra_curhoplimit,
1148                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1149                         sizeof(ntopbuf)), rai->rai_hoplimit);
1150                 inconsistent++;
1151         }
1152         /* M flag */
1153         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
1154             rai->rai_managedflg) {
1155                 syslog(LOG_NOTICE,
1156                     "M flag inconsistent on %s:"
1157                     " %s from %s, %s from us",
1158                     ifi->ifi_ifname, on_off[!rai->rai_managedflg],
1159                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1160                         sizeof(ntopbuf)), on_off[rai->rai_managedflg]);
1161                 inconsistent++;
1162         }
1163         /* O flag */
1164         if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
1165             rai->rai_otherflg) {
1166                 syslog(LOG_NOTICE,
1167                     "O flag inconsistent on %s:"
1168                     " %s from %s, %s from us",
1169                     ifi->ifi_ifname, on_off[!rai->rai_otherflg],
1170                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1171                         sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
1172                 inconsistent++;
1173         }
1174         /* Reachable Time */
1175         reachabletime = ntohl(nra->nd_ra_reachable);
1176         if (reachabletime && rai->rai_reachabletime &&
1177             reachabletime != rai->rai_reachabletime) {
1178                 syslog(LOG_NOTICE,
1179                     "ReachableTime inconsistent on %s:"
1180                     " %d from %s, %d from us",
1181                     ifi->ifi_ifname, reachabletime,
1182                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1183                         sizeof(ntopbuf)), rai->rai_reachabletime);
1184                 inconsistent++;
1185         }
1186         /* Retrans Timer */
1187         retranstimer = ntohl(nra->nd_ra_retransmit);
1188         if (retranstimer && rai->rai_retranstimer &&
1189             retranstimer != rai->rai_retranstimer) {
1190                 syslog(LOG_NOTICE,
1191                     "RetranceTimer inconsistent on %s:"
1192                     " %d from %s, %d from us",
1193                     ifi->ifi_ifname, retranstimer,
1194                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1195                         sizeof(ntopbuf)), rai->rai_retranstimer);
1196                 inconsistent++;
1197         }
1198         /* Values in the MTU options */
1199         if (ndopts.opt_mtu) {
1200                 mtu = ntohl(ndopts.opt_mtu->nd_opt_mtu_mtu);
1201                 if (mtu && rai->rai_linkmtu && mtu != rai->rai_linkmtu) {
1202                         syslog(LOG_NOTICE,
1203                             "MTU option value inconsistent on %s:"
1204                             " %d from %s, %d from us",
1205                             ifi->ifi_ifname, mtu,
1206                             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
1207                                 sizeof(ntopbuf)), rai->rai_linkmtu);
1208                         inconsistent++;
1209                 }
1210         }
1211         /* Preferred and Valid Lifetimes for prefixes */
1212         {
1213                 struct nd_optlist *nol;
1214
1215                 if (ndopts.opt_pi)
1216                         if (prefix_check(ndopts.opt_pi, rai, from))
1217                                 inconsistent++;
1218
1219                 TAILQ_FOREACH(nol, &ndopts.opt_list, nol_next)
1220                         if (prefix_check((struct nd_opt_prefix_info *)nol->nol_opt,
1221                                 rai, from))
1222                                 inconsistent++;
1223         }
1224
1225         if (inconsistent)
1226                 ifi->ifi_rainconsistent++;
1227
1228   done:
1229         free_ndopts(&ndopts);
1230         return;
1231 }
1232
1233 /* return a non-zero value if the received prefix is inconsitent 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                     abs(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                     abs(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 #ifdef HAVE_ARC4RANDOM
1892                 interval += arc4random_uniform(rai->rai_maxinterval -
1893                     rai->rai_mininterval);
1894 #else
1895                 interval += random() % (rai->rai_maxinterval -
1896                     rai->rai_mininterval);
1897 #endif
1898                 break;
1899         case IFI_STATE_TRANSITIVE:
1900                 /*
1901                  * For the first few advertisements (up to
1902                  * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen
1903                  * interval is greater than
1904                  * MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer SHOULD be
1905                  * set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.  (RFC
1906                  * 4861 6.2.4)
1907                  *
1908                  * In such cases, the router SHOULD transmit one or more
1909                  * (but not more than MAX_FINAL_RTR_ADVERTISEMENTS) final
1910                  * multicast Router Advertisements on the interface with a
1911                  * Router Lifetime field of zero.  (RFC 4861 6.2.5)
1912                  */
1913                 interval = ifi->ifi_burstinterval;
1914                 break;
1915         }
1916
1917         tm->tv_sec = interval;
1918         tm->tv_nsec = 0;
1919
1920         syslog(LOG_DEBUG,
1921             "<%s> RA timer on %s is set to %ld:%ld",
1922             __func__, ifi->ifi_ifname,
1923             (long int)tm->tv_sec, (long int)tm->tv_nsec / 1000);
1924
1925         return;
1926 }