usr.sbin/rtadvd/rtadvd.c

   1 /*      $KAME: rtadvd.c,v 1.50 2001/02/04 06:15:15 itojun Exp $ */
   2
   3 /*
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/usr.sbin/rtadvd/rtadvd.c,v 1.3.2.4 2003/04/05 10:31:58 ume Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/socket.h>
  36 #include <sys/uio.h>
  37 #include <sys/time.h>
  38 #include <sys/queue.h>
  39
  40 #include <net/if.h>
  41 #include <net/route.h>
  42 #include <net/if_dl.h>
  43 #include <netinet/in.h>
  44 #include <netinet/ip6.h>
  45 #include <netinet6/ip6_var.h>
  46 #include <netinet/icmp6.h>
  47
  48 #include <arpa/inet.h>
  49
  50 #include <time.h>
  51 #include <unistd.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <err.h>
  55 #include <errno.h>
  56 #include <string.h>
  57 #include <stdlib.h>
  58 #include <syslog.h>
  59 #include "rtadvd.h"
  60 #include "rrenum.h"
  61 #include "advcap.h"
  62 #include "timer.h"
  63 #include "if.h"
  64 #include "config.h"
  65 #include "dump.h"
  66
  67 struct msghdr rcvmhdr;
  68 static u_char *rcvcmsgbuf;
  69 static size_t rcvcmsgbuflen;
  70 static u_char *sndcmsgbuf = NULL;
  71 static size_t sndcmsgbuflen;
  72 static int do_dump;
  73 static int do_die;
  74 struct msghdr sndmhdr;
  75 struct iovec rcviov[2];
  76 struct iovec sndiov[2];
  77 struct sockaddr_in6 from;
  78 struct sockaddr_in6 sin6_allnodes = {sizeof(sin6_allnodes), AF_INET6};
  79 struct in6_addr in6a_site_allrouters;
  80 static char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX: should be configurable */
  81 static char *pidfilename = "/var/run/rtadvd.pid"; /* should be configurable */
  82 static char *mcastif;
  83 int sock;
  84 int rtsock = -1;
  85 #ifdef MIP6
  86 int mobileip6 = 0;
  87 #endif
  88 int accept_rr = 0;
  89 int dflag = 0, sflag = 0;
  90
  91 u_char *conffile = NULL;
  92
  93 struct rainfo *ralist = NULL;
  94 struct nd_optlist {
  95         struct nd_optlist *next;
  96         struct nd_opt_hdr *opt;
  97 };
  98 union nd_opts {
  99         struct nd_opt_hdr *nd_opt_array[7];
 100         struct {
 101                 struct nd_opt_hdr *zero;
 102                 struct nd_opt_hdr *src_lladdr;
 103                 struct nd_opt_hdr *tgt_lladdr;
 104                 struct nd_opt_prefix_info *pi;
 105                 struct nd_opt_rd_hdr *rh;
 106                 struct nd_opt_mtu *mtu;
 107                 struct nd_optlist *list;
 108         } nd_opt_each;
 109 };
 110 #define nd_opts_src_lladdr      nd_opt_each.src_lladdr
 111 #define nd_opts_tgt_lladdr      nd_opt_each.tgt_lladdr
 112 #define nd_opts_pi              nd_opt_each.pi
 113 #define nd_opts_rh              nd_opt_each.rh
 114 #define nd_opts_mtu             nd_opt_each.mtu
 115 #define nd_opts_list            nd_opt_each.list
 116
 117 #define NDOPT_FLAG_SRCLINKADDR 0x1
 118 #define NDOPT_FLAG_TGTLINKADDR 0x2
 119 #define NDOPT_FLAG_PREFIXINFO 0x4
 120 #define NDOPT_FLAG_RDHDR 0x8
 121 #define NDOPT_FLAG_MTU 0x10
 122
 123 u_int32_t ndopt_flags[] = {
 124         0, NDOPT_FLAG_SRCLINKADDR, NDOPT_FLAG_TGTLINKADDR,
 125         NDOPT_FLAG_PREFIXINFO, NDOPT_FLAG_RDHDR, NDOPT_FLAG_MTU
 126 };
 127
 128 int main(int, char *[]);
 129 static void set_die(int);
 130 static void die(void);
 131 static void sock_open(void);
 132 static void rtsock_open(void);
 133 static void rtadvd_input(void);
 134 static void rs_input(int, struct nd_router_solicit *,
 135                           struct in6_pktinfo *, struct sockaddr_in6 *);
 136 static void ra_input(int, struct nd_router_advert *,
 137                           struct in6_pktinfo *, struct sockaddr_in6 *);
 138 static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
 139                              struct sockaddr_in6 *);
 140 static int nd6_options(struct nd_opt_hdr *, int,
 141                             union nd_opts *, u_int32_t);
 142 static void free_ndopts(union nd_opts *);
 143 static void ra_output(struct rainfo *);
 144 static void rtmsg_input(void);
 145 static void rtadvd_set_dump_file(void);
 146
 147 int
 148 main(int argc, char *argv[])
 149 {
 150         fd_set fdset;
 151         int maxfd = 0;
 152         struct timeval *timeout;
 153         int i, ch;
 154         int fflag = 0;
 155         FILE *pidfp;
 156         pid_t pid;
 157
 158         openlog("rtadvd", LOG_NDELAY|LOG_PID, LOG_DAEMON);
 159
 160         /* get command line options and arguments */
 161 #ifdef MIP6
 162 #define OPTIONS "c:dDfM:mRs"
 163 #else
 164 #define OPTIONS "c:dDfM:Rs"
 165 #endif
 166         while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
 167 #undef OPTIONS
 168                 switch (ch) {
 169                 case 'c':
 170                         conffile = optarg;
 171                         break;
 172                 case 'd':
 173                         dflag = 1;
 174                         break;
 175                 case 'D':
 176                         dflag = 2;
 177                         break;
 178                 case 'f':
 179                         fflag = 1;
 180                         break;
 181                 case 'M':
 182                         mcastif = optarg;
 183                         break;
 184 #ifdef MIP6
 185                 case 'm':
 186                         mobileip6 = 1;
 187                         break;
 188 #endif
 189                 case 'R':
 190                         fprintf(stderr, "rtadvd: "
 191                                 "the -R option is currently ignored.\n");
 192                         /* accept_rr = 1; */
 193                         /* run anyway... */
 194                         break;
 195                 case 's':
 196                         sflag = 1;
 197                         break;
 198                 }
 199         }
 200         argc -= optind;
 201         argv += optind;
 202         if (argc == 0) {
 203                 fprintf(stderr,
 204 #ifdef MIP6
 205                         "usage: rtadvd [-dDfMmRs] [-c conffile] "
 206 #else
 207                         "usage: rtadvd [-dDfMRs] [-c conffile] "
 208 #endif
 209                         "interfaces...\n");
 210                 exit(1);
 211         }
 212
 213         /* set log level */
 214         if (dflag == 0)
 215                 setlogmask(LOG_UPTO(LOG_ERR));
 216         if (dflag == 1)
 217                 setlogmask(LOG_UPTO(LOG_INFO));
 218
 219         /* timer initialization */
 220         rtadvd_timer_init();
 221
 222         /* random value initialization */
 223         srandom((u_long)time(NULL));
 224
 225         /* get iflist block from kernel */
 226         init_iflist();
 227
 228         while (argc--)
 229                 getconfig(*argv++);
 230
 231         if (inet_pton(AF_INET6, ALLNODES, &sin6_allnodes.sin6_addr) != 1) {
 232                 fprintf(stderr, "fatal: inet_pton failed\n");
 233                 exit(1);
 234         }
 235         sock_open();
 236
 237         if (!fflag)
 238                 daemon(1, 0);
 239
 240         /* record the current PID */
 241         pid = getpid();
 242         if ((pidfp = fopen(pidfilename, "w")) == NULL) {
 243                 syslog(LOG_ERR,
 244                     "<%s> failed to open a log file(%s), run anyway.",
 245                     __func__, pidfilename);
 246         } else {
 247                 fprintf(pidfp, "%d\n", pid);
 248                 fclose(pidfp);
 249         }
 250
 251         FD_ZERO(&fdset);
 252         FD_SET(sock, &fdset);
 253         maxfd = sock;
 254         if (sflag == 0) {
 255                 rtsock_open();
 256                 FD_SET(rtsock, &fdset);
 257                 if (rtsock > sock)
 258                         maxfd = rtsock;
 259         } else
 260                 rtsock = -1;
 261
 262         signal(SIGTERM, (void *)set_die);
 263         signal(SIGUSR1, (void *)rtadvd_set_dump_file);
 264
 265         while (1) {
 266                 struct fd_set select_fd = fdset; /* reinitialize */
 267
 268                 if (do_dump) {  /* SIGUSR1 */
 269                         do_dump = 0;
 270                         rtadvd_dump_file(dumpfilename);
 271                 }
 272
 273                 if (do_die) {
 274                         die();
 275                         /*NOTREACHED*/
 276                 }
 277
 278                 /* timer expiration check and reset the timer */
 279                 timeout = rtadvd_check_timer();
 280
 281                 if (timeout != NULL) {
 282                         syslog(LOG_DEBUG,
 283                             "<%s> set timer to %ld:%ld. waiting for "
 284                             "inputs or timeout", __func__,
 285                             (long int)timeout->tv_sec,
 286                             (long int)timeout->tv_usec);
 287                 } else {
 288                         syslog(LOG_DEBUG,
 289                             "<%s> there's no timer. waiting for inputs",
 290                             __func__);
 291                 }
 292
 293                 if ((i = select(maxfd + 1, &select_fd,
 294                                 NULL, NULL, timeout)) < 0) {
 295                         /* EINTR would occur upon SIGUSR1 for status dump */
 296                         if (errno != EINTR)
 297                                 syslog(LOG_ERR, "<%s> select: %s",
 298                                     __func__, strerror(errno));
 299                         continue;
 300                 }
 301                 if (i == 0)     /* timeout */
 302                         continue;
 303                 if (rtsock != -1 && FD_ISSET(rtsock, &select_fd))
 304                         rtmsg_input();
 305                 if (FD_ISSET(sock, &select_fd))
 306                         rtadvd_input();
 307         }
 308         exit(0);                /* NOTREACHED */
 309 }
 310
 311 static void
 312 rtadvd_set_dump_file(void)
 313 {
 314         do_dump = 1;
 315 }
 316
 317 static void
 318 set_die(int sig)
 319 {
 320         do_die = 1;
 321 }
 322
 323 static void
 324 die(void)
 325 {
 326         struct rainfo *ra;
 327         int i;
 328         const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
 329
 330         if (dflag > 1) {
 331                 syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
 332                     __func__);
 333         }
 334
 335         for (ra = ralist; ra; ra = ra->next) {
 336                 ra->lifetime = 0;
 337                 make_packet(ra);
 338         }
 339         for (i = 0; i < retrans; i++) {
 340                 for (ra = ralist; ra; ra = ra->next)
 341                         ra_output(ra);
 342                 sleep(MIN_DELAY_BETWEEN_RAS);
 343         }
 344         exit(0);
 345         /*NOTREACHED*/
 346 }
 347
 348 static void
 349 rtmsg_input(void)
 350 {
 351         int n, type, ifindex = 0, plen;
 352         size_t len;
 353         char msg[2048], *next, *lim;
 354         u_char ifname[IF_NAMESIZE];
 355         struct prefix *prefix;
 356         struct rainfo *rai;
 357         struct in6_addr *addr;
 358         char addrbuf[INET6_ADDRSTRLEN];
 359
 360         n = read(rtsock, msg, sizeof(msg));
 361         if (dflag > 1) {
 362                 syslog(LOG_DEBUG, "<%s> received a routing message "
 363                     "(type = %d, len = %d)", __func__, rtmsg_type(msg), n);
 364         }
 365         if (n > rtmsg_len(msg)) {
 366                 /*
 367                  * This usually won't happen for messages received on
 368                  * a routing socket.
 369                  */
 370                 if (dflag > 1)
 371                         syslog(LOG_DEBUG,
 372                             "<%s> received data length is larger than "
 373                             "1st routing message len. multiple messages? "
 374                             "read %d bytes, but 1st msg len = %d",
 375                             __func__, n, rtmsg_len(msg));
 376 #if 0
 377                 /* adjust length */
 378                 n = rtmsg_len(msg);
 379 #endif
 380         }
 381
 382         lim = msg + n;
 383         for (next = msg; next < lim; next += len) {
 384                 int oldifflags;
 385
 386                 next = get_next_msg(next, lim, 0, &len,
 387                                     RTADV_TYPE2BITMASK(RTM_ADD) |
 388                                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 389                                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 390                                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 391                                     RTADV_TYPE2BITMASK(RTM_IFINFO));
 392                 if (len == 0)
 393                         break;
 394                 type = rtmsg_type(next);
 395                 switch (type) {
 396                 case RTM_ADD:
 397                 case RTM_DELETE:
 398                         ifindex = get_rtm_ifindex(next);
 399                         break;
 400                 case RTM_NEWADDR:
 401                 case RTM_DELADDR:
 402                         ifindex = get_ifam_ifindex(next);
 403                         break;
 404                 case RTM_IFINFO:
 405                         ifindex = get_ifm_ifindex(next);
 406                         break;
 407                 default:
 408                         /* should not reach here */
 409                         if (dflag > 1) {
 410                                 syslog(LOG_DEBUG,
 411                                        "<%s:%d> unknown rtmsg %d on %s",
 412                                        __func__, __LINE__, type,
 413                                        if_indextoname(ifindex, ifname));
 414                         }
 415                         continue;
 416                 }
 417
 418                 if ((rai = if_indextorainfo(ifindex)) == NULL) {
 419                         if (dflag > 1) {
 420                                 syslog(LOG_DEBUG,
 421                                        "<%s> route changed on "
 422                                        "non advertising interface(%s)",
 423                                        __func__,
 424                                        if_indextoname(ifindex, ifname));
 425                         }
 426                         continue;
 427                 }
 428                 oldifflags = iflist[ifindex]->ifm_flags;
 429
 430                 switch (type) {
 431                 case RTM_ADD:
 432                         /* init ifflags because it may have changed */
 433                         iflist[ifindex]->ifm_flags =
 434                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 435
 436                         if (sflag)
 437                                 break;  /* we aren't interested in prefixes  */
 438
 439                         addr = get_addr(msg);
 440                         plen = get_prefixlen(msg);
 441                         /* sanity check for plen */
 442                         /* as RFC2373, prefixlen is at least 4 */
 443                         if (plen < 4 || plen > 127) {
 444                                 syslog(LOG_INFO, "<%s> new interface route's"
 445                                     "plen %d is invalid for a prefix",
 446                                     __func__, plen);
 447                                 break;
 448                         }
 449                         prefix = find_prefix(rai, addr, plen);
 450                         if (prefix) {
 451                                 if (prefix->timer) {
 452                                         /*
 453                                          * If the prefix has been invalidated,
 454                                          * make it available again.
 455                                          */
 456                                         update_prefix(prefix);
 457                                 } else if (dflag > 1) {
 458                                         syslog(LOG_DEBUG,
 459                                             "<%s> new prefix(%s/%d) "
 460                                             "added on %s, "
 461                                             "but it was already in list",
 462                                             __func__,
 463                                             inet_ntop(AF_INET6, addr,
 464                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 465                                             plen, rai->ifname);
 466                                 }
 467                                 break;
 468                         }
 469                         make_prefix(rai, ifindex, addr, plen);
 470                         break;
 471                 case RTM_DELETE:
 472                         /* init ifflags because it may have changed */
 473                         iflist[ifindex]->ifm_flags =
 474                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 475
 476                         if (sflag)
 477                                 break;
 478
 479                         addr = get_addr(msg);
 480                         plen = get_prefixlen(msg);
 481                         /* sanity check for plen */
 482                         /* as RFC2373, prefixlen is at least 4 */
 483                         if (plen < 4 || plen > 127) {
 484                                 syslog(LOG_INFO,
 485                                     "<%s> deleted interface route's "
 486                                     "plen %d is invalid for a prefix",
 487                                     __func__, plen);
 488                                 break;
 489                         }
 490                         prefix = find_prefix(rai, addr, plen);
 491                         if (prefix == NULL) {
 492                                 if (dflag > 1) {
 493                                         syslog(LOG_DEBUG,
 494                                             "<%s> prefix(%s/%d) was "
 495                                             "deleted on %s, "
 496                                             "but it was not in list",
 497                                             __func__,
 498                                             inet_ntop(AF_INET6, addr,
 499                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 500                                             plen, rai->ifname);
 501                                 }
 502                                 break;
 503                         }
 504                         invalidate_prefix(prefix);
 505                         break;
 506                 case RTM_NEWADDR:
 507                 case RTM_DELADDR:
 508                         /* init ifflags because it may have changed */
 509                         iflist[ifindex]->ifm_flags =
 510                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 511                         break;
 512                 case RTM_IFINFO:
 513                         iflist[ifindex]->ifm_flags = get_ifm_flags(next);
 514                         break;
 515                 default:
 516                         /* should not reach here */
 517                         if (dflag > 1) {
 518                                 syslog(LOG_DEBUG,
 519                                     "<%s:%d> unknown rtmsg %d on %s",
 520                                     __func__, __LINE__, type,
 521                                     if_indextoname(ifindex, ifname));
 522                         }
 523                         return;
 524                 }
 525
 526                 /* check if an interface flag is changed */
 527                 if ((oldifflags & IFF_UP) != 0 &&       /* UP to DOWN */
 528                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0) {
 529                         syslog(LOG_INFO,
 530                             "<%s> interface %s becomes down. stop timer.",
 531                             __func__, rai->ifname);
 532                         rtadvd_remove_timer(&rai->timer);
 533                 } else if ((oldifflags & IFF_UP) == 0 &&        /* DOWN to UP */
 534                          (iflist[ifindex]->ifm_flags & IFF_UP) != 0) {
 535                         syslog(LOG_INFO,
 536                             "<%s> interface %s becomes up. restart timer.",
 537                             __func__, rai->ifname);
 538
 539                         rai->initcounter = 0; /* reset the counter */
 540                         rai->waiting = 0; /* XXX */
 541                         rai->timer = rtadvd_add_timer(ra_timeout,
 542                             ra_timer_update, rai, rai);
 543                         ra_timer_update((void *)rai, &rai->timer->tm);
 544                         rtadvd_set_timer(&rai->timer->tm, rai->timer);
 545                 }
 546         }
 547
 548         return;
 549 }
 550
 551 void
 552 rtadvd_input(void)
 553 {
 554         int i;
 555         int *hlimp = NULL;
 556 #ifdef OLDRAWSOCKET
 557         struct ip6_hdr *ip;
 558 #endif
 559         struct icmp6_hdr *icp;
 560         int ifindex = 0;
 561         struct cmsghdr *cm;
 562         struct in6_pktinfo *pi = NULL;
 563         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 564         struct in6_addr dst = in6addr_any;
 565
 566         /*
 567          * Get message. We reset msg_controllen since the field could
 568          * be modified if we had received a message before setting
 569          * receive options.
 570          */
 571         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 572         if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
 573                 return;
 574
 575         /* extract optional information via Advanced API */
 576         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 577              cm;
 578              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 579                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 580                     cm->cmsg_type == IPV6_PKTINFO &&
 581                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 582                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 583                         ifindex = pi->ipi6_ifindex;
 584                         dst = pi->ipi6_addr;
 585                 }
 586                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 587                     cm->cmsg_type == IPV6_HOPLIMIT &&
 588                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 589                         hlimp = (int *)CMSG_DATA(cm);
 590         }
 591         if (ifindex == 0) {
 592                 syslog(LOG_ERR,
 593                        "<%s> failed to get receiving interface",
 594                        __func__);
 595                 return;
 596         }
 597         if (hlimp == NULL) {
 598                 syslog(LOG_ERR,
 599                        "<%s> failed to get receiving hop limit",
 600                        __func__);
 601                 return;
 602         }
 603
 604         /*
 605          * If we happen to receive data on an interface which is now down,
 606          * just discard the data.
 607          */
 608         if ((iflist[pi->ipi6_ifindex]->ifm_flags & IFF_UP) == 0) {
 609                 syslog(LOG_INFO,
 610                        "<%s> received data on a disabled interface (%s)",
 611                        __func__,
 612                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 613                 return;
 614         }
 615
 616 #ifdef OLDRAWSOCKET
 617         if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 618                 syslog(LOG_ERR,
 619                        "<%s> packet size(%d) is too short",
 620                        __func__, i);
 621                 return;
 622         }
 623
 624         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 625         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 626 #else
 627         if (i < sizeof(struct icmp6_hdr)) {
 628                 syslog(LOG_ERR,
 629                        "<%s> packet size(%d) is too short",
 630                        __func__, i);
 631                 return;
 632         }
 633
 634         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 635 #endif
 636
 637         switch (icp->icmp6_type) {
 638         case ND_ROUTER_SOLICIT:
 639                 /*
 640                  * Message verification - RFC-2461 6.1.1
 641                  * XXX: these checks must be done in the kernel as well,
 642                  *      but we can't completely rely on them.
 643                  */
 644                 if (*hlimp != 255) {
 645                         syslog(LOG_NOTICE,
 646                             "<%s> RS with invalid hop limit(%d) "
 647                             "received from %s on %s",
 648                             __func__, *hlimp,
 649                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 650                             INET6_ADDRSTRLEN),
 651                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 652                         return;
 653                 }
 654                 if (icp->icmp6_code) {
 655                         syslog(LOG_NOTICE,
 656                             "<%s> RS with invalid ICMP6 code(%d) "
 657                             "received from %s on %s",
 658                             __func__, icp->icmp6_code,
 659                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 660                             INET6_ADDRSTRLEN),
 661                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 662                         return;
 663                 }
 664                 if (i < sizeof(struct nd_router_solicit)) {
 665                         syslog(LOG_NOTICE,
 666                             "<%s> RS from %s on %s does not have enough "
 667                             "length (len = %d)",
 668                             __func__,
 669                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 670                             INET6_ADDRSTRLEN),
 671                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 672                         return;
 673                 }
 674                 rs_input(i, (struct nd_router_solicit *)icp, pi, &from);
 675                 break;
 676         case ND_ROUTER_ADVERT:
 677                 /*
 678                  * Message verification - RFC-2461 6.1.2
 679                  * XXX: there's a same dilemma as above...
 680                  */
 681                 if (*hlimp != 255) {
 682                         syslog(LOG_NOTICE,
 683                             "<%s> RA with invalid hop limit(%d) "
 684                             "received from %s on %s",
 685                             __func__, *hlimp,
 686                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 687                             INET6_ADDRSTRLEN),
 688                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 689                         return;
 690                 }
 691                 if (icp->icmp6_code) {
 692                         syslog(LOG_NOTICE,
 693                             "<%s> RA with invalid ICMP6 code(%d) "
 694                             "received from %s on %s",
 695                             __func__, icp->icmp6_code,
 696                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 697                             INET6_ADDRSTRLEN),
 698                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 699                         return;
 700                 }
 701                 if (i < sizeof(struct nd_router_advert)) {
 702                         syslog(LOG_NOTICE,
 703                             "<%s> RA from %s on %s does not have enough "
 704                             "length (len = %d)",
 705                             __func__,
 706                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 707                             INET6_ADDRSTRLEN),
 708                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 709                         return;
 710                 }
 711                 ra_input(i, (struct nd_router_advert *)icp, pi, &from);
 712                 break;
 713         case ICMP6_ROUTER_RENUMBERING:
 714                 if (accept_rr == 0) {
 715                         syslog(LOG_ERR, "<%s> received a router renumbering "
 716                             "message, but not allowed to be accepted",
 717                             __func__);
 718                         break;
 719                 }
 720                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &from,
 721                          &dst);
 722                 break;
 723         default:
 724                 /*
 725                  * Note that this case is POSSIBLE, especially just
 726                  * after invocation of the daemon. This is because we
 727                  * could receive message after opening the socket and
 728                  * before setting ICMP6 type filter(see sock_open()).
 729                  */
 730                 syslog(LOG_ERR, "<%s> invalid icmp type(%d)",
 731                     __func__, icp->icmp6_type);
 732                 return;
 733         }
 734
 735         return;
 736 }
 737
 738 static void
 739 rs_input(int len, struct nd_router_solicit *rs,
 740          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 741 {
 742         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 743         union nd_opts ndopts;
 744         struct rainfo *ra;
 745
 746         syslog(LOG_DEBUG,
 747                "<%s> RS received from %s on %s",
 748                __func__,
 749                inet_ntop(AF_INET6, &from->sin6_addr,
 750                          ntopbuf, INET6_ADDRSTRLEN),
 751                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 752
 753         /* ND option check */
 754         memset(&ndopts, 0, sizeof(ndopts));
 755         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 756                         len - sizeof(struct nd_router_solicit),
 757                          &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 758                 syslog(LOG_DEBUG,
 759                        "<%s> ND option check failed for an RS from %s on %s",
 760                        __func__,
 761                        inet_ntop(AF_INET6, &from->sin6_addr,
 762                                  ntopbuf, INET6_ADDRSTRLEN),
 763                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 764                 return;
 765         }
 766
 767         /*
 768          * If the IP source address is the unspecified address, there
 769          * must be no source link-layer address option in the message.
 770          * (RFC-2461 6.1.1)
 771          */
 772         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 773             ndopts.nd_opts_src_lladdr) {
 774                 syslog(LOG_ERR,
 775                        "<%s> RS from unspecified src on %s has a link-layer"
 776                        " address option",
 777                        __func__,
 778                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 779                 goto done;
 780         }
 781
 782         ra = ralist;
 783         while (ra != NULL) {
 784                 if (pi->ipi6_ifindex == ra->ifindex)
 785                         break;
 786                 ra = ra->next;
 787         }
 788         if (ra == NULL) {
 789                 syslog(LOG_INFO,
 790                        "<%s> RS received on non advertising interface(%s)",
 791                        __func__,
 792                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 793                 goto done;
 794         }
 795
 796         ra->rsinput++;          /* increment statistics */
 797
 798         /*
 799          * Decide whether to send RA according to the rate-limit
 800          * consideration.
 801          */
 802         {
 803                 long delay;     /* must not be greater than 1000000 */
 804                 struct timeval interval, now, min_delay, tm_tmp, *rest;
 805                 struct soliciter *sol;
 806
 807                 /*
 808                  * record sockaddr waiting for RA, if possible
 809                  */
 810                 sol = (struct soliciter *)malloc(sizeof(*sol));
 811                 if (sol) {
 812                         sol->addr = *from;
 813                         /*XXX RFC2553 need clarification on flowinfo */
 814                         sol->addr.sin6_flowinfo = 0;
 815                         sol->next = ra->soliciter;
 816                         ra->soliciter = sol->next;
 817                 }
 818
 819                 /*
 820                  * If there is already a waiting RS packet, don't
 821                  * update the timer.
 822                  */
 823                 if (ra->waiting++)
 824                         goto done;
 825
 826                 /*
 827                  * Compute a random delay. If the computed value
 828                  * corresponds to a time later than the time the next
 829                  * multicast RA is scheduled to be sent, ignore the random
 830                  * delay and send the advertisement at the
 831                  * already-scheduled time. RFC-2461 6.2.6
 832                  */
 833                 delay = random() % MAX_RA_DELAY_TIME;
 834                 interval.tv_sec = 0;
 835                 interval.tv_usec = delay;
 836                 rest = rtadvd_timer_rest(ra->timer);
 837                 if (TIMEVAL_LT(*rest, interval)) {
 838                         syslog(LOG_DEBUG,
 839                                "<%s> random delay is larger than "
 840                                "the rest of normal timer",
 841                                __func__);
 842                         interval = *rest;
 843                 }
 844
 845                 /*
 846                  * If we sent a multicast Router Advertisement within
 847                  * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
 848                  * the advertisement to be sent at a time corresponding to
 849                  * MIN_DELAY_BETWEEN_RAS plus the random value after the
 850                  * previous advertisement was sent.
 851                  */
 852                 gettimeofday(&now, NULL);
 853                 TIMEVAL_SUB(&now, &ra->lastsent, &tm_tmp);
 854                 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
 855                 min_delay.tv_usec = 0;
 856                 if (TIMEVAL_LT(tm_tmp, min_delay)) {
 857                         TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
 858                         TIMEVAL_ADD(&min_delay, &interval, &interval);
 859                 }
 860                 rtadvd_set_timer(&interval, ra->timer);
 861                 goto done;
 862         }
 863
 864   done:
 865         free_ndopts(&ndopts);
 866         return;
 867 }
 868
 869 static void
 870 ra_input(int len, struct nd_router_advert *ra,
 871          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 872 {
 873         struct rainfo *rai;
 874         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 875         union nd_opts ndopts;
 876         char *on_off[] = {"OFF", "ON"};
 877         u_int32_t reachabletime, retranstimer, mtu;
 878         int inconsistent = 0;
 879
 880         syslog(LOG_DEBUG,
 881                "<%s> RA received from %s on %s",
 882                __func__,
 883                inet_ntop(AF_INET6, &from->sin6_addr,
 884                          ntopbuf, INET6_ADDRSTRLEN),
 885                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 886
 887         /* ND option check */
 888         memset(&ndopts, 0, sizeof(ndopts));
 889         if (nd6_options((struct nd_opt_hdr *)(ra + 1),
 890                         len - sizeof(struct nd_router_advert),
 891                         &ndopts, NDOPT_FLAG_SRCLINKADDR |
 892                         NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
 893                 syslog(LOG_ERR,
 894                        "<%s> ND option check failed for an RA from %s on %s",
 895                        __func__,
 896                        inet_ntop(AF_INET6, &from->sin6_addr,
 897                                  ntopbuf, INET6_ADDRSTRLEN),
 898                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 899                 return;
 900         }
 901
 902         /*
 903          * RA consistency check according to RFC-2461 6.2.7
 904          */
 905         if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
 906                 syslog(LOG_INFO,
 907                        "<%s> received RA from %s on non-advertising"
 908                        " interface(%s)",
 909                        __func__,
 910                        inet_ntop(AF_INET6, &from->sin6_addr,
 911                                  ntopbuf, INET6_ADDRSTRLEN),
 912                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 913                 goto done;
 914         }
 915         rai->rainput++;         /* increment statistics */
 916
 917         /* Cur Hop Limit value */
 918         if (ra->nd_ra_curhoplimit && rai->hoplimit &&
 919             ra->nd_ra_curhoplimit != rai->hoplimit) {
 920                 syslog(LOG_INFO,
 921                        "<%s> CurHopLimit inconsistent on %s:"
 922                        " %d from %s, %d from us",
 923                        __func__,
 924                        rai->ifname,
 925                        ra->nd_ra_curhoplimit,
 926                        inet_ntop(AF_INET6, &from->sin6_addr,
 927                                  ntopbuf, INET6_ADDRSTRLEN),
 928                        rai->hoplimit);
 929                 inconsistent++;
 930         }
 931         /* M flag */
 932         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
 933             rai->managedflg) {
 934                 syslog(LOG_INFO,
 935                        "<%s> M flag inconsistent on %s:"
 936                        " %s from %s, %s from us",
 937                        __func__,
 938                        rai->ifname,
 939                        on_off[!rai->managedflg],
 940                        inet_ntop(AF_INET6, &from->sin6_addr,
 941                                  ntopbuf, INET6_ADDRSTRLEN),
 942                        on_off[rai->managedflg]);
 943                 inconsistent++;
 944         }
 945         /* O flag */
 946         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
 947             rai->otherflg) {
 948                 syslog(LOG_INFO,
 949                        "<%s> O flag inconsistent on %s:"
 950                        " %s from %s, %s from us",
 951                        __func__,
 952                        rai->ifname,
 953                        on_off[!rai->otherflg],
 954                        inet_ntop(AF_INET6, &from->sin6_addr,
 955                                  ntopbuf, INET6_ADDRSTRLEN),
 956                        on_off[rai->otherflg]);
 957                 inconsistent++;
 958         }
 959         /* Reachable Time */
 960         reachabletime = ntohl(ra->nd_ra_reachable);
 961         if (reachabletime && rai->reachabletime &&
 962             reachabletime != rai->reachabletime) {
 963                 syslog(LOG_INFO,
 964                        "<%s> ReachableTime inconsistent on %s:"
 965                        " %d from %s, %d from us",
 966                        __func__,
 967                        rai->ifname,
 968                        reachabletime,
 969                        inet_ntop(AF_INET6, &from->sin6_addr,
 970                                  ntopbuf, INET6_ADDRSTRLEN),
 971                        rai->reachabletime);
 972                 inconsistent++;
 973         }
 974         /* Retrans Timer */
 975         retranstimer = ntohl(ra->nd_ra_retransmit);
 976         if (retranstimer && rai->retranstimer &&
 977             retranstimer != rai->retranstimer) {
 978                 syslog(LOG_INFO,
 979                        "<%s> RetranceTimer inconsistent on %s:"
 980                        " %d from %s, %d from us",
 981                        __func__,
 982                        rai->ifname,
 983                        retranstimer,
 984                        inet_ntop(AF_INET6, &from->sin6_addr,
 985                                  ntopbuf, INET6_ADDRSTRLEN),
 986                        rai->retranstimer);
 987                 inconsistent++;
 988         }
 989         /* Values in the MTU options */
 990         if (ndopts.nd_opts_mtu) {
 991                 mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
 992                 if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
 993                         syslog(LOG_INFO,
 994                                "<%s> MTU option value inconsistent on %s:"
 995                                " %d from %s, %d from us",
 996                                __func__,
 997                                rai->ifname, mtu,
 998                                inet_ntop(AF_INET6, &from->sin6_addr,
 999                                          ntopbuf, INET6_ADDRSTRLEN),
1000                                rai->linkmtu);
1001                         inconsistent++;
1002                 }
1003         }
1004         /* Preferred and Valid Lifetimes for prefixes */
1005         {
1006                 struct nd_optlist *optp = ndopts.nd_opts_list;
1007
1008                 if (ndopts.nd_opts_pi) {
1009                         if (prefix_check(ndopts.nd_opts_pi, rai, from))
1010                                 inconsistent++;
1011                 }
1012                 while (optp) {
1013                         if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
1014                                          rai, from))
1015                                 inconsistent++;
1016                         optp = optp->next;
1017                 }
1018         }
1019
1020         if (inconsistent)
1021                 rai->rainconsistent++;
1022
1023 done:
1024         free_ndopts(&ndopts);
1025         return;
1026 }
1027
1028 /* return a non-zero value if the received prefix is inconsitent with ours */
1029 static int
1030 prefix_check(struct nd_opt_prefix_info *pinfo,
1031              struct rainfo *rai, struct sockaddr_in6 *from)
1032 {
1033         u_int32_t preferred_time, valid_time;
1034         struct prefix *pp;
1035         int inconsistent = 0;
1036         u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
1037         struct timeval now;
1038
1039 #if 0                           /* impossible */
1040         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1041                 return(0);
1042 #endif
1043
1044         /*
1045          * log if the adveritsed prefix has link-local scope(sanity check?)
1046          */
1047         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
1048                 syslog(LOG_INFO,
1049                        "<%s> link-local prefix %s/%d is advertised "
1050                        "from %s on %s",
1051                        __func__,
1052                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1053                                  prefixbuf, INET6_ADDRSTRLEN),
1054                        pinfo->nd_opt_pi_prefix_len,
1055                        inet_ntop(AF_INET6, &from->sin6_addr,
1056                                  ntopbuf, INET6_ADDRSTRLEN),
1057                        rai->ifname);
1058         }
1059
1060         if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1061                               pinfo->nd_opt_pi_prefix_len)) == NULL) {
1062                 syslog(LOG_INFO,
1063                        "<%s> prefix %s/%d from %s on %s is not in our list",
1064                        __func__,
1065                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1066                                  prefixbuf, INET6_ADDRSTRLEN),
1067                        pinfo->nd_opt_pi_prefix_len,
1068                        inet_ntop(AF_INET6, &from->sin6_addr,
1069                                  ntopbuf, INET6_ADDRSTRLEN),
1070                        rai->ifname);
1071                 return(0);
1072         }
1073
1074         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1075         if (pp->pltimeexpire) {
1076                 /*
1077                  * The lifetime is decremented in real time, so we should
1078                  * compare the expiration time.
1079                  * (RFC 2461 Section 6.2.7.)
1080                  * XXX: can we really expect that all routers on the link
1081                  * have synchronized clocks?
1082                  */
1083                 gettimeofday(&now, NULL);
1084                 preferred_time += now.tv_sec;
1085
1086                 if (rai->clockskew &&
1087                     abs(preferred_time - pp->pltimeexpire) > rai->clockskew) {
1088                         syslog(LOG_INFO,
1089                                "<%s> prefeerred lifetime for %s/%d"
1090                                " (decr. in real time) inconsistent on %s:"
1091                                " %d from %s, %ld from us",
1092                                __func__,
1093                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1094                                          prefixbuf, INET6_ADDRSTRLEN),
1095                                pinfo->nd_opt_pi_prefix_len,
1096                                rai->ifname, preferred_time,
1097                                inet_ntop(AF_INET6, &from->sin6_addr,
1098                                          ntopbuf, INET6_ADDRSTRLEN),
1099                                pp->pltimeexpire);
1100                         inconsistent++;
1101                 }
1102         } else if (preferred_time != pp->preflifetime) {
1103                 syslog(LOG_INFO,
1104                        "<%s> prefeerred lifetime for %s/%d"
1105                        " inconsistent on %s:"
1106                        " %d from %s, %d from us",
1107                        __func__,
1108                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1109                                  prefixbuf, INET6_ADDRSTRLEN),
1110                        pinfo->nd_opt_pi_prefix_len,
1111                        rai->ifname, preferred_time,
1112                        inet_ntop(AF_INET6, &from->sin6_addr,
1113                                  ntopbuf, INET6_ADDRSTRLEN),
1114                        pp->preflifetime);
1115         }
1116
1117         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1118         if (pp->vltimeexpire) {
1119                 gettimeofday(&now, NULL);
1120                 valid_time += now.tv_sec;
1121
1122                 if (rai->clockskew &&
1123                     abs(valid_time - pp->vltimeexpire) > rai->clockskew) {
1124                         syslog(LOG_INFO,
1125                                "<%s> valid lifetime for %s/%d"
1126                                " (decr. in real time) inconsistent on %s:"
1127                                " %d from %s, %ld from us",
1128                                __func__,
1129                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1130                                          prefixbuf, INET6_ADDRSTRLEN),
1131                                pinfo->nd_opt_pi_prefix_len,
1132                                rai->ifname, preferred_time,
1133                                inet_ntop(AF_INET6, &from->sin6_addr,
1134                                          ntopbuf, INET6_ADDRSTRLEN),
1135                                pp->vltimeexpire);
1136                         inconsistent++;
1137                 }
1138         } else if (valid_time != pp->validlifetime) {
1139                 syslog(LOG_INFO,
1140                        "<%s> valid lifetime for %s/%d"
1141                        " inconsistent on %s:"
1142                        " %d from %s, %d from us",
1143                        __func__,
1144                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1145                                  prefixbuf, INET6_ADDRSTRLEN),
1146                        pinfo->nd_opt_pi_prefix_len,
1147                        rai->ifname, valid_time,
1148                        inet_ntop(AF_INET6, &from->sin6_addr,
1149                                  ntopbuf, INET6_ADDRSTRLEN),
1150                        pp->validlifetime);
1151                 inconsistent++;
1152         }
1153
1154         return(inconsistent);
1155 }
1156
1157 struct prefix *
1158 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1159 {
1160         struct prefix *pp;
1161         int bytelen, bitlen;
1162
1163         for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
1164                 if (plen != pp->prefixlen)
1165                         continue;
1166                 bytelen = plen / 8;
1167                 bitlen = plen % 8;
1168                 if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1169                         continue;
1170                 if (prefix->s6_addr[bytelen] >> (8 - bitlen) ==
1171                     pp->prefix.s6_addr[bytelen] >> (8 - bitlen))
1172                         return(pp);
1173         }
1174
1175         return(NULL);
1176 }
1177
1178 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1179 int
1180 prefix_match(struct in6_addr *p0, int plen0,
1181              struct in6_addr *p1, int plen1)
1182 {
1183         int bytelen, bitlen;
1184
1185         if (plen0 < plen1)
1186                 return(0);
1187         bytelen = plen1 / 8;
1188         bitlen = plen1 % 8;
1189         if (memcmp((void *)p0, (void *)p1, bytelen))
1190                 return(0);
1191         if (p0->s6_addr[bytelen] >> (8 - bitlen) ==
1192             p1->s6_addr[bytelen] >> (8 - bitlen))
1193                 return(1);
1194
1195         return(0);
1196 }
1197
1198 static int
1199 nd6_options(struct nd_opt_hdr *hdr, int limit,
1200             union nd_opts *ndopts, u_int32_t optflags)
1201 {
1202         int optlen = 0;
1203
1204         for (; limit > 0; limit -= optlen) {
1205                 if (limit < sizeof(struct nd_opt_hdr)) {
1206                         syslog(LOG_INFO, "<%s> short option header", __func__);
1207                         goto bad;
1208                 }
1209
1210                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1211                 if (hdr->nd_opt_len == 0) {
1212                         syslog(LOG_INFO,
1213                             "<%s> bad ND option length(0) (type = %d)",
1214                             __func__, hdr->nd_opt_type);
1215                         goto bad;
1216                 }
1217                 optlen = hdr->nd_opt_len << 3;
1218                 if (optlen > limit) {
1219                         syslog(LOG_INFO, "<%s> short option", __func__);
1220                         goto bad;
1221                 }
1222
1223                 if (hdr->nd_opt_type > ND_OPT_MTU) {
1224                         syslog(LOG_INFO,
1225                             "<%s> unknown ND option(type %d)",
1226                             __func__, hdr->nd_opt_type);
1227                         continue;
1228                 }
1229
1230                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1231                         syslog(LOG_INFO,
1232                             "<%s> unexpected ND option(type %d)",
1233                                __func__, hdr->nd_opt_type);
1234                         continue;
1235                 }
1236
1237                 /*
1238                  * Option length check.  Do it here for all fixed-length
1239                  * options.
1240                  */
1241                 if ((hdr->nd_opt_type == ND_OPT_MTU &&
1242                     (optlen != sizeof(struct nd_opt_mtu))) ||
1243                     ((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION &&
1244                     optlen != sizeof(struct nd_opt_prefix_info)))) {
1245                         syslog(LOG_INFO, "<%s> invalid option length",
1246                             __func__);
1247                         continue;
1248                 }
1249
1250                 switch (hdr->nd_opt_type) {
1251                 case ND_OPT_SOURCE_LINKADDR:
1252                 case ND_OPT_TARGET_LINKADDR:
1253                 case ND_OPT_REDIRECTED_HEADER:
1254                         break;  /* we don't care about these options */
1255                 case ND_OPT_MTU:
1256                         if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1257                                 syslog(LOG_INFO,
1258                                     "<%s> duplicated ND option (type = %d)",
1259                                     __func__, hdr->nd_opt_type);
1260                         }
1261                         ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1262                         break;
1263                 case ND_OPT_PREFIX_INFORMATION:
1264                 {
1265                         struct nd_optlist *pfxlist;
1266
1267                         if (ndopts->nd_opts_pi == 0) {
1268                                 ndopts->nd_opts_pi =
1269                                     (struct nd_opt_prefix_info *)hdr;
1270                                 continue;
1271                         }
1272                         if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1273                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1274                                     __func__);
1275                                 goto bad;
1276                         }
1277                         pfxlist->next = ndopts->nd_opts_list;
1278                         pfxlist->opt = hdr;
1279                         ndopts->nd_opts_list = pfxlist;
1280
1281                         break;
1282                 }
1283                 default:        /* impossible */
1284                         break;
1285                 }
1286         }
1287
1288         return(0);
1289
1290   bad:
1291         free_ndopts(ndopts);
1292
1293         return(-1);
1294 }
1295
1296 static void
1297 free_ndopts(union nd_opts *ndopts)
1298 {
1299         struct nd_optlist *opt = ndopts->nd_opts_list, *next;
1300
1301         while (opt) {
1302                 next = opt->next;
1303                 free(opt);
1304                 opt = next;
1305         }
1306 }
1307
1308 void
1309 sock_open(void)
1310 {
1311         struct icmp6_filter filt;
1312         struct ipv6_mreq mreq;
1313         struct rainfo *ra = ralist;
1314         int on;
1315         /* XXX: should be max MTU attached to the node */
1316         static u_char answer[1500];
1317
1318         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1319                                 CMSG_SPACE(sizeof(int));
1320         rcvcmsgbuf = (u_char *)malloc(rcvcmsgbuflen);
1321         if (rcvcmsgbuf == NULL) {
1322                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1323                 exit(1);
1324         }
1325
1326         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1327                                 CMSG_SPACE(sizeof(int));
1328         sndcmsgbuf = (u_char *)malloc(sndcmsgbuflen);
1329         if (sndcmsgbuf == NULL) {
1330                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1331                 exit(1);
1332         }
1333
1334         if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1335                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
1336                        strerror(errno));
1337                 exit(1);
1338         }
1339
1340         /* specify to tell receiving interface */
1341         on = 1;
1342 #ifdef IPV6_RECVPKTINFO
1343         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1344                        sizeof(on)) < 0) {
1345                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
1346                        __func__, strerror(errno));
1347                 exit(1);
1348         }
1349 #else  /* old adv. API */
1350         if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1351                        sizeof(on)) < 0) {
1352                 syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
1353                        __func__, strerror(errno));
1354                 exit(1);
1355         }
1356 #endif
1357
1358         on = 1;
1359         /* specify to tell value of hoplimit field of received IP6 hdr */
1360 #ifdef IPV6_RECVHOPLIMIT
1361         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1362                        sizeof(on)) < 0) {
1363                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
1364                        __func__, strerror(errno));
1365                 exit(1);
1366         }
1367 #else  /* old adv. API */
1368         if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1369                        sizeof(on)) < 0) {
1370                 syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
1371                        __func__, strerror(errno));
1372                 exit(1);
1373         }
1374 #endif
1375
1376         ICMP6_FILTER_SETBLOCKALL(&filt);
1377         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1378         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1379         if (accept_rr)
1380                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1381         if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1382                        sizeof(filt)) < 0) {
1383                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1384                        __func__, strerror(errno));
1385                 exit(1);
1386         }
1387
1388         /*
1389          * join all routers multicast address on each advertising interface.
1390          */
1391         if (inet_pton(AF_INET6, ALLROUTERS_LINK,
1392                       &mreq.ipv6mr_multiaddr.s6_addr)
1393             != 1) {
1394                 syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1395                        __func__);
1396                 exit(1);
1397         }
1398         while (ra) {
1399                 mreq.ipv6mr_interface = ra->ifindex;
1400                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
1401                                sizeof(mreq)) < 0) {
1402                         syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP(link) on %s: %s",
1403                                __func__, ra->ifname, strerror(errno));
1404                         exit(1);
1405                 }
1406                 ra = ra->next;
1407         }
1408
1409         /*
1410          * When attending router renumbering, join all-routers site-local
1411          * multicast group.
1412          */
1413         if (accept_rr) {
1414                 if (inet_pton(AF_INET6, ALLROUTERS_SITE,
1415                               &in6a_site_allrouters) != 1) {
1416                         syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1417                                __func__);
1418                         exit(1);
1419                 }
1420                 mreq.ipv6mr_multiaddr = in6a_site_allrouters;
1421                 if (mcastif) {
1422                         if ((mreq.ipv6mr_interface = if_nametoindex(mcastif))
1423                             == 0) {
1424                                 syslog(LOG_ERR,
1425                                        "<%s> invalid interface: %s",
1426                                        __func__, mcastif);
1427                                 exit(1);
1428                         }
1429                 } else
1430                         mreq.ipv6mr_interface = ralist->ifindex;
1431                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1432                                &mreq, sizeof(mreq)) < 0) {
1433                         syslog(LOG_ERR,
1434                                "<%s> IPV6_JOIN_GROUP(site) on %s: %s",
1435                                __func__,
1436                                mcastif ? mcastif : ralist->ifname,
1437                                strerror(errno));
1438                         exit(1);
1439                 }
1440         }
1441
1442         /* initialize msghdr for receiving packets */
1443         rcviov[0].iov_base = (caddr_t)answer;
1444         rcviov[0].iov_len = sizeof(answer);
1445         rcvmhdr.msg_name = (caddr_t)&from;
1446         rcvmhdr.msg_namelen = sizeof(from);
1447         rcvmhdr.msg_iov = rcviov;
1448         rcvmhdr.msg_iovlen = 1;
1449         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1450         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1451
1452         /* initialize msghdr for sending packets */
1453         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1454         sndmhdr.msg_iov = sndiov;
1455         sndmhdr.msg_iovlen = 1;
1456         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1457         sndmhdr.msg_controllen = sndcmsgbuflen;
1458
1459         return;
1460 }
1461
1462 /* open a routing socket to watch the routing table */
1463 static void
1464 rtsock_open(void)
1465 {
1466         if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1467                 syslog(LOG_ERR,
1468                        "<%s> socket: %s", __func__, strerror(errno));
1469                 exit(1);
1470         }
1471 }
1472
1473 struct rainfo *
1474 if_indextorainfo(int index)
1475 {
1476         struct rainfo *rai = ralist;
1477
1478         for (rai = ralist; rai; rai = rai->next) {
1479                 if (rai->ifindex == index)
1480                         return(rai);
1481         }
1482
1483         return(NULL);           /* search failed */
1484 }
1485
1486 static void
1487 ra_output(struct rainfo *rainfo)
1488 {
1489         int i;
1490         struct cmsghdr *cm;
1491         struct in6_pktinfo *pi;
1492         struct soliciter *sol, *nextsol;
1493
1494         if ((iflist[rainfo->ifindex]->ifm_flags & IFF_UP) == 0) {
1495                 syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1496                        __func__, rainfo->ifname);
1497                 return;
1498         }
1499
1500         make_packet(rainfo);    /* XXX: inefficient */
1501
1502         sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
1503         sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
1504         sndmhdr.msg_iov[0].iov_len = rainfo->ra_datalen;
1505
1506         cm = CMSG_FIRSTHDR(&sndmhdr);
1507         /* specify the outgoing interface */
1508         cm->cmsg_level = IPPROTO_IPV6;
1509         cm->cmsg_type = IPV6_PKTINFO;
1510         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1511         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1512         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1513         pi->ipi6_ifindex = rainfo->ifindex;
1514
1515         /* specify the hop limit of the packet */
1516         {
1517                 int hoplimit = 255;
1518
1519                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1520                 cm->cmsg_level = IPPROTO_IPV6;
1521                 cm->cmsg_type = IPV6_HOPLIMIT;
1522                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1523                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1524         }
1525
1526         syslog(LOG_DEBUG,
1527                "<%s> send RA on %s, # of waitings = %d",
1528                __func__, rainfo->ifname, rainfo->waiting);
1529
1530         i = sendmsg(sock, &sndmhdr, 0);
1531
1532         if (i < 0 || i != rainfo->ra_datalen)  {
1533                 if (i < 0) {
1534                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1535                                __func__, rainfo->ifname,
1536                                strerror(errno));
1537                 }
1538         }
1539
1540         /*
1541          * unicast advertisements
1542          * XXX commented out.  reason: though spec does not forbit it, unicast
1543          * advert does not really help
1544          */
1545         for (sol = rainfo->soliciter; sol; sol = nextsol) {
1546                 nextsol = sol->next;
1547
1548 #if 0
1549                 sndmhdr.msg_name = (caddr_t)&sol->addr;
1550                 i = sendmsg(sock, &sndmhdr, 0);
1551                 if (i < 0 || i != rainfo->ra_datalen)  {
1552                         if (i < 0) {
1553                                 syslog(LOG_ERR,
1554                                     "<%s> unicast sendmsg on %s: %s",
1555                                     __func__, rainfo->ifname,
1556                                     strerror(errno));
1557                         }
1558                 }
1559 #endif
1560
1561                 sol->next = NULL;
1562                 free(sol);
1563         }
1564         rainfo->soliciter = NULL;
1565
1566         /* update counter */
1567         if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1568                 rainfo->initcounter++;
1569         rainfo->raoutput++;
1570
1571         /* update timestamp */
1572         gettimeofday(&rainfo->lastsent, NULL);
1573
1574         /* reset waiting conter */
1575         rainfo->waiting = 0;
1576 }
1577
1578 /* process RA timer */
1579 struct rtadvd_timer *
1580 ra_timeout(void *data)
1581 {
1582         struct rainfo *rai = (struct rainfo *)data;
1583
1584 #ifdef notyet
1585         /* if necessary, reconstruct the packet. */
1586 #endif
1587
1588         syslog(LOG_DEBUG,
1589                "<%s> RA timer on %s is expired",
1590                __func__, rai->ifname);
1591
1592         ra_output(rai);
1593
1594         return(rai->timer);
1595 }
1596
1597 /* update RA timer */
1598 void
1599 ra_timer_update(void *data, struct timeval *tm)
1600 {
1601         struct rainfo *rai = (struct rainfo *)data;
1602         long interval;
1603
1604         /*
1605          * Whenever a multicast advertisement is sent from an interface,
1606          * the timer is reset to a uniformly-distributed random value
1607          * between the interface's configured MinRtrAdvInterval and
1608          * MaxRtrAdvInterval (RFC2461 6.2.4).
1609          */
1610         interval = rai->mininterval;
1611         interval += random() % (rai->maxinterval - rai->mininterval);
1612
1613         /*
1614          * For the first few advertisements (up to
1615          * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1616          * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1617          * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1618          * (RFC-2461 6.2.4)
1619          */
1620         if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1621             interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1622                 interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1623
1624         tm->tv_sec = interval;
1625         tm->tv_usec = 0;
1626
1627         syslog(LOG_DEBUG,
1628                "<%s> RA timer on %s is set to %ld:%ld",
1629                __func__, rai->ifname,
1630                (long int)tm->tv_sec, (long int)tm->tv_usec);
1631
1632         return;
1633 }