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  * $DragonFly: src/usr.sbin/rtadvd/rtadvd.c,v 1.6 2005/12/05 00:56:37 swildner Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/socket.h>
  37 #include <sys/uio.h>
  38 #include <sys/time.h>
  39 #include <sys/queue.h>
  40
  41 #include <net/if.h>
  42 #include <net/route.h>
  43 #include <net/if_dl.h>
  44 #include <netinet/in.h>
  45 #include <netinet/ip6.h>
  46 #include <netinet6/ip6_var.h>
  47 #include <netinet/icmp6.h>
  48
  49 #include <arpa/inet.h>
  50
  51 #include <time.h>
  52 #include <unistd.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <err.h>
  56 #include <errno.h>
  57 #include <string.h>
  58 #include <stdlib.h>
  59 #include <syslog.h>
  60 #include "rtadvd.h"
  61 #include "rrenum.h"
  62 #include "advcap.h"
  63 #include "timer.h"
  64 #include "if.h"
  65 #include "config.h"
  66 #include "dump.h"
  67
  68 struct msghdr rcvmhdr;
  69 static u_char *rcvcmsgbuf;
  70 static size_t rcvcmsgbuflen;
  71 static u_char *sndcmsgbuf = NULL;
  72 static size_t sndcmsgbuflen;
  73 static int do_dump;
  74 static int do_die;
  75 struct msghdr sndmhdr;
  76 struct iovec rcviov[2];
  77 struct iovec sndiov[2];
  78 struct sockaddr_in6 from;
  79 struct sockaddr_in6 sin6_allnodes = {sizeof(sin6_allnodes), AF_INET6};
  80 struct in6_addr in6a_site_allrouters;
  81 static char *dumpfilename = "/var/run/rtadvd.dump"; /* XXX: should be configurable */
  82 static char *pidfilename = "/var/run/rtadvd.pid"; /* should be configurable */
  83 static char *mcastif;
  84 int sock;
  85 int rtsock = -1;
  86 #ifdef MIP6
  87 int mobileip6 = 0;
  88 #endif
  89 int accept_rr = 0;
  90 int dflag = 0, sflag = 0;
  91
  92 u_char *conffile = NULL;
  93
  94 struct rainfo *ralist = NULL;
  95 struct nd_optlist {
  96         struct nd_optlist *next;
  97         struct nd_opt_hdr *opt;
  98 };
  99 union nd_opts {
 100         struct nd_opt_hdr *nd_opt_array[7];
 101         struct {
 102                 struct nd_opt_hdr *zero;
 103                 struct nd_opt_hdr *src_lladdr;
 104                 struct nd_opt_hdr *tgt_lladdr;
 105                 struct nd_opt_prefix_info *pi;
 106                 struct nd_opt_rd_hdr *rh;
 107                 struct nd_opt_mtu *mtu;
 108                 struct nd_optlist *list;
 109         } nd_opt_each;
 110 };
 111 #define nd_opts_src_lladdr      nd_opt_each.src_lladdr
 112 #define nd_opts_tgt_lladdr      nd_opt_each.tgt_lladdr
 113 #define nd_opts_pi              nd_opt_each.pi
 114 #define nd_opts_rh              nd_opt_each.rh
 115 #define nd_opts_mtu             nd_opt_each.mtu
 116 #define nd_opts_list            nd_opt_each.list
 117
 118 #define NDOPT_FLAG_SRCLINKADDR 0x1
 119 #define NDOPT_FLAG_TGTLINKADDR 0x2
 120 #define NDOPT_FLAG_PREFIXINFO 0x4
 121 #define NDOPT_FLAG_RDHDR 0x8
 122 #define NDOPT_FLAG_MTU 0x10
 123
 124 u_int32_t ndopt_flags[] = {
 125         0, NDOPT_FLAG_SRCLINKADDR, NDOPT_FLAG_TGTLINKADDR,
 126         NDOPT_FLAG_PREFIXINFO, NDOPT_FLAG_RDHDR, NDOPT_FLAG_MTU
 127 };
 128
 129 int main(int, char *[]);
 130 static void set_die(int);
 131 static void die(void);
 132 static void sock_open(void);
 133 static void rtsock_open(void);
 134 static void rtadvd_input(void);
 135 static void rs_input(int, struct nd_router_solicit *,
 136                           struct in6_pktinfo *, struct sockaddr_in6 *);
 137 static void ra_input(int, struct nd_router_advert *,
 138                           struct in6_pktinfo *, struct sockaddr_in6 *);
 139 static int prefix_check(struct nd_opt_prefix_info *, struct rainfo *,
 140                              struct sockaddr_in6 *);
 141 static int nd6_options(struct nd_opt_hdr *, int,
 142                             union nd_opts *, u_int32_t);
 143 static void free_ndopts(union nd_opts *);
 144 static void ra_output(struct rainfo *);
 145 static void rtmsg_input(void);
 146 static void rtadvd_set_dump_file(void);
 147
 148 int
 149 main(int argc, char *argv[])
 150 {
 151         fd_set fdset;
 152         int maxfd = 0;
 153         struct timeval *timeout;
 154         int i, ch;
 155         int fflag = 0;
 156         FILE *pidfp;
 157         pid_t pid;
 158
 159         openlog("rtadvd", LOG_NDELAY|LOG_PID, LOG_DAEMON);
 160
 161         /* get command line options and arguments */
 162 #ifdef MIP6
 163 #define OPTIONS "c:dDfM:mRs"
 164 #else
 165 #define OPTIONS "c:dDfM:Rs"
 166 #endif
 167         while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
 168 #undef OPTIONS
 169                 switch (ch) {
 170                 case 'c':
 171                         conffile = optarg;
 172                         break;
 173                 case 'd':
 174                         dflag = 1;
 175                         break;
 176                 case 'D':
 177                         dflag = 2;
 178                         break;
 179                 case 'f':
 180                         fflag = 1;
 181                         break;
 182                 case 'M':
 183                         mcastif = optarg;
 184                         break;
 185 #ifdef MIP6
 186                 case 'm':
 187                         mobileip6 = 1;
 188                         break;
 189 #endif
 190                 case 'R':
 191                         fprintf(stderr, "rtadvd: "
 192                                 "the -R option is currently ignored.\n");
 193                         /* accept_rr = 1; */
 194                         /* run anyway... */
 195                         break;
 196                 case 's':
 197                         sflag = 1;
 198                         break;
 199                 }
 200         }
 201         argc -= optind;
 202         argv += optind;
 203         if (argc == 0) {
 204                 fprintf(stderr,
 205 #ifdef MIP6
 206                         "usage: rtadvd [-dDfMmRs] [-c conffile] "
 207 #else
 208                         "usage: rtadvd [-dDfMRs] [-c conffile] "
 209 #endif
 210                         "interfaces...\n");
 211                 exit(1);
 212         }
 213
 214         /* set log level */
 215         if (dflag == 0)
 216                 setlogmask(LOG_UPTO(LOG_ERR));
 217         if (dflag == 1)
 218                 setlogmask(LOG_UPTO(LOG_INFO));
 219
 220         /* timer initialization */
 221         rtadvd_timer_init();
 222
 223         /* random value initialization */
 224         srandom((u_long)time(NULL));
 225
 226         /* get iflist block from kernel */
 227         init_iflist();
 228
 229         while (argc--)
 230                 getconfig(*argv++);
 231
 232         if (inet_pton(AF_INET6, ALLNODES, &sin6_allnodes.sin6_addr) != 1) {
 233                 fprintf(stderr, "fatal: inet_pton failed\n");
 234                 exit(1);
 235         }
 236         sock_open();
 237
 238         if (!fflag)
 239                 daemon(1, 0);
 240
 241         /* record the current PID */
 242         pid = getpid();
 243         if ((pidfp = fopen(pidfilename, "w")) == NULL) {
 244                 syslog(LOG_ERR,
 245                     "<%s> failed to open a log file(%s), run anyway.",
 246                     __func__, pidfilename);
 247         } else {
 248                 fprintf(pidfp, "%d\n", pid);
 249                 fclose(pidfp);
 250         }
 251
 252         FD_ZERO(&fdset);
 253         FD_SET(sock, &fdset);
 254         maxfd = sock;
 255         if (sflag == 0) {
 256                 rtsock_open();
 257                 FD_SET(rtsock, &fdset);
 258                 if (rtsock > sock)
 259                         maxfd = rtsock;
 260         } else
 261                 rtsock = -1;
 262
 263         signal(SIGTERM, (void *)set_die);
 264         signal(SIGUSR1, (void *)rtadvd_set_dump_file);
 265
 266         while (1) {
 267                 struct fd_set select_fd = fdset; /* reinitialize */
 268
 269                 if (do_dump) {  /* SIGUSR1 */
 270                         do_dump = 0;
 271                         rtadvd_dump_file(dumpfilename);
 272                 }
 273
 274                 if (do_die) {
 275                         die();
 276                         /*NOTREACHED*/
 277                 }
 278
 279                 /* timer expiration check and reset the timer */
 280                 timeout = rtadvd_check_timer();
 281
 282                 if (timeout != NULL) {
 283                         syslog(LOG_DEBUG,
 284                             "<%s> set timer to %ld:%ld. waiting for "
 285                             "inputs or timeout", __func__,
 286                             (long int)timeout->tv_sec,
 287                             (long int)timeout->tv_usec);
 288                 } else {
 289                         syslog(LOG_DEBUG,
 290                             "<%s> there's no timer. waiting for inputs",
 291                             __func__);
 292                 }
 293
 294                 if ((i = select(maxfd + 1, &select_fd,
 295                                 NULL, NULL, timeout)) < 0) {
 296                         /* EINTR would occur upon SIGUSR1 for status dump */
 297                         if (errno != EINTR)
 298                                 syslog(LOG_ERR, "<%s> select: %s",
 299                                     __func__, strerror(errno));
 300                         continue;
 301                 }
 302                 if (i == 0)     /* timeout */
 303                         continue;
 304                 if (rtsock != -1 && FD_ISSET(rtsock, &select_fd))
 305                         rtmsg_input();
 306                 if (FD_ISSET(sock, &select_fd))
 307                         rtadvd_input();
 308         }
 309         exit(0);                /* NOTREACHED */
 310 }
 311
 312 static void
 313 rtadvd_set_dump_file(void)
 314 {
 315         do_dump = 1;
 316 }
 317
 318 static void
 319 set_die(int sig)
 320 {
 321         do_die = 1;
 322 }
 323
 324 static void
 325 die(void)
 326 {
 327         struct rainfo *ra;
 328         int i;
 329         const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
 330
 331         if (dflag > 1) {
 332                 syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
 333                     __func__);
 334         }
 335
 336         for (ra = ralist; ra; ra = ra->next) {
 337                 ra->lifetime = 0;
 338                 make_packet(ra);
 339         }
 340         for (i = 0; i < retrans; i++) {
 341                 for (ra = ralist; ra; ra = ra->next)
 342                         ra_output(ra);
 343                 sleep(MIN_DELAY_BETWEEN_RAS);
 344         }
 345         exit(0);
 346         /*NOTREACHED*/
 347 }
 348
 349 static void
 350 rtmsg_input(void)
 351 {
 352         int n, type, ifindex = 0, plen;
 353         size_t len;
 354         char msg[2048], *next, *lim;
 355         u_char ifname[IF_NAMESIZE];
 356         struct prefix *prefix;
 357         struct rainfo *rai;
 358         struct in6_addr *addr;
 359         char addrbuf[INET6_ADDRSTRLEN];
 360
 361         n = read(rtsock, msg, sizeof(msg));
 362         if (dflag > 1) {
 363                 syslog(LOG_DEBUG, "<%s> received a routing message "
 364                     "(type = %d, len = %d)", __func__, rtmsg_type(msg), n);
 365         }
 366         if (n > rtmsg_len(msg)) {
 367                 /*
 368                  * This usually won't happen for messages received on
 369                  * a routing socket.
 370                  */
 371                 if (dflag > 1)
 372                         syslog(LOG_DEBUG,
 373                             "<%s> received data length is larger than "
 374                             "1st routing message len. multiple messages? "
 375                             "read %d bytes, but 1st msg len = %d",
 376                             __func__, n, rtmsg_len(msg));
 377 #if 0
 378                 /* adjust length */
 379                 n = rtmsg_len(msg);
 380 #endif
 381         }
 382
 383         lim = msg + n;
 384         for (next = msg; next < lim; next += len) {
 385                 int oldifflags;
 386
 387                 next = get_next_msg(next, lim, 0, &len,
 388                                     RTADV_TYPE2BITMASK(RTM_ADD) |
 389                                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 390                                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 391                                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 392                                     RTADV_TYPE2BITMASK(RTM_IFINFO));
 393                 if (len == 0)
 394                         break;
 395                 type = rtmsg_type(next);
 396                 switch (type) {
 397                 case RTM_ADD:
 398                 case RTM_DELETE:
 399                         ifindex = get_rtm_ifindex(next);
 400                         break;
 401                 case RTM_NEWADDR:
 402                 case RTM_DELADDR:
 403                         ifindex = get_ifam_ifindex(next);
 404                         break;
 405                 case RTM_IFINFO:
 406                         ifindex = get_ifm_ifindex(next);
 407                         break;
 408                 default:
 409                         /* should not reach here */
 410                         if (dflag > 1) {
 411                                 syslog(LOG_DEBUG,
 412                                        "<%s:%d> unknown rtmsg %d on %s",
 413                                        __func__, __LINE__, type,
 414                                        if_indextoname(ifindex, ifname));
 415                         }
 416                         continue;
 417                 }
 418
 419                 if ((rai = if_indextorainfo(ifindex)) == NULL) {
 420                         if (dflag > 1) {
 421                                 syslog(LOG_DEBUG,
 422                                        "<%s> route changed on "
 423                                        "non advertising interface(%s)",
 424                                        __func__,
 425                                        if_indextoname(ifindex, ifname));
 426                         }
 427                         continue;
 428                 }
 429                 oldifflags = iflist[ifindex]->ifm_flags;
 430
 431                 switch (type) {
 432                 case RTM_ADD:
 433                         /* init ifflags because it may have changed */
 434                         iflist[ifindex]->ifm_flags =
 435                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 436
 437                         if (sflag)
 438                                 break;  /* we aren't interested in prefixes  */
 439
 440                         addr = get_addr(msg);
 441                         plen = get_prefixlen(msg);
 442                         /* sanity check for plen */
 443                         /* as RFC2373, prefixlen is at least 4 */
 444                         if (plen < 4 || plen > 127) {
 445                                 syslog(LOG_INFO, "<%s> new interface route's"
 446                                     "plen %d is invalid for a prefix",
 447                                     __func__, plen);
 448                                 break;
 449                         }
 450                         prefix = find_prefix(rai, addr, plen);
 451                         if (prefix) {
 452                                 if (prefix->timer) {
 453                                         /*
 454                                          * If the prefix has been invalidated,
 455                                          * make it available again.
 456                                          */
 457                                         update_prefix(prefix);
 458                                 } else if (dflag > 1) {
 459                                         syslog(LOG_DEBUG,
 460                                             "<%s> new prefix(%s/%d) "
 461                                             "added on %s, "
 462                                             "but it was already in list",
 463                                             __func__,
 464                                             inet_ntop(AF_INET6, addr,
 465                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 466                                             plen, rai->ifname);
 467                                 }
 468                                 break;
 469                         }
 470                         make_prefix(rai, ifindex, addr, plen);
 471                         break;
 472                 case RTM_DELETE:
 473                         /* init ifflags because it may have changed */
 474                         iflist[ifindex]->ifm_flags =
 475                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 476
 477                         if (sflag)
 478                                 break;
 479
 480                         addr = get_addr(msg);
 481                         plen = get_prefixlen(msg);
 482                         /* sanity check for plen */
 483                         /* as RFC2373, prefixlen is at least 4 */
 484                         if (plen < 4 || plen > 127) {
 485                                 syslog(LOG_INFO,
 486                                     "<%s> deleted interface route's "
 487                                     "plen %d is invalid for a prefix",
 488                                     __func__, plen);
 489                                 break;
 490                         }
 491                         prefix = find_prefix(rai, addr, plen);
 492                         if (prefix == NULL) {
 493                                 if (dflag > 1) {
 494                                         syslog(LOG_DEBUG,
 495                                             "<%s> prefix(%s/%d) was "
 496                                             "deleted on %s, "
 497                                             "but it was not in list",
 498                                             __func__,
 499                                             inet_ntop(AF_INET6, addr,
 500                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 501                                             plen, rai->ifname);
 502                                 }
 503                                 break;
 504                         }
 505                         invalidate_prefix(prefix);
 506                         break;
 507                 case RTM_NEWADDR:
 508                 case RTM_DELADDR:
 509                         /* init ifflags because it may have changed */
 510                         iflist[ifindex]->ifm_flags =
 511                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 512                         break;
 513                 case RTM_IFINFO:
 514                         iflist[ifindex]->ifm_flags = get_ifm_flags(next);
 515                         break;
 516                 default:
 517                         /* should not reach here */
 518                         if (dflag > 1) {
 519                                 syslog(LOG_DEBUG,
 520                                     "<%s:%d> unknown rtmsg %d on %s",
 521                                     __func__, __LINE__, type,
 522                                     if_indextoname(ifindex, ifname));
 523                         }
 524                         return;
 525                 }
 526
 527                 /* check if an interface flag is changed */
 528                 if ((oldifflags & IFF_UP) != 0 &&       /* UP to DOWN */
 529                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0) {
 530                         syslog(LOG_INFO,
 531                             "<%s> interface %s becomes down. stop timer.",
 532                             __func__, rai->ifname);
 533                         rtadvd_remove_timer(&rai->timer);
 534                 } else if ((oldifflags & IFF_UP) == 0 &&        /* DOWN to UP */
 535                          (iflist[ifindex]->ifm_flags & IFF_UP) != 0) {
 536                         syslog(LOG_INFO,
 537                             "<%s> interface %s becomes up. restart timer.",
 538                             __func__, rai->ifname);
 539
 540                         rai->initcounter = 0; /* reset the counter */
 541                         rai->waiting = 0; /* XXX */
 542                         rai->timer = rtadvd_add_timer(ra_timeout,
 543                             ra_timer_update, rai, rai);
 544                         ra_timer_update((void *)rai, &rai->timer->tm);
 545                         rtadvd_set_timer(&rai->timer->tm, rai->timer);
 546                 }
 547         }
 548
 549         return;
 550 }
 551
 552 void
 553 rtadvd_input(void)
 554 {
 555         int i;
 556         int *hlimp = NULL;
 557 #ifdef OLDRAWSOCKET
 558         struct ip6_hdr *ip;
 559 #endif
 560         struct icmp6_hdr *icp;
 561         int ifindex = 0;
 562         struct cmsghdr *cm;
 563         struct in6_pktinfo *pi = NULL;
 564         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 565         struct in6_addr dst = in6addr_any;
 566
 567         /*
 568          * Get message. We reset msg_controllen since the field could
 569          * be modified if we had received a message before setting
 570          * receive options.
 571          */
 572         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 573         if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
 574                 return;
 575
 576         /* extract optional information via Advanced API */
 577         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 578              cm;
 579              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 580                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 581                     cm->cmsg_type == IPV6_PKTINFO &&
 582                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 583                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 584                         ifindex = pi->ipi6_ifindex;
 585                         dst = pi->ipi6_addr;
 586                 }
 587                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 588                     cm->cmsg_type == IPV6_HOPLIMIT &&
 589                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 590                         hlimp = (int *)CMSG_DATA(cm);
 591         }
 592         if (ifindex == 0) {
 593                 syslog(LOG_ERR,
 594                        "<%s> failed to get receiving interface",
 595                        __func__);
 596                 return;
 597         }
 598         if (hlimp == NULL) {
 599                 syslog(LOG_ERR,
 600                        "<%s> failed to get receiving hop limit",
 601                        __func__);
 602                 return;
 603         }
 604
 605         /*
 606          * If we happen to receive data on an interface which is now down,
 607          * just discard the data.
 608          */
 609         if ((iflist[pi->ipi6_ifindex]->ifm_flags & IFF_UP) == 0) {
 610                 syslog(LOG_INFO,
 611                        "<%s> received data on a disabled interface (%s)",
 612                        __func__,
 613                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 614                 return;
 615         }
 616
 617 #ifdef OLDRAWSOCKET
 618         if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 619                 syslog(LOG_ERR,
 620                        "<%s> packet size(%d) is too short",
 621                        __func__, i);
 622                 return;
 623         }
 624
 625         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 626         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 627 #else
 628         if (i < sizeof(struct icmp6_hdr)) {
 629                 syslog(LOG_ERR,
 630                        "<%s> packet size(%d) is too short",
 631                        __func__, i);
 632                 return;
 633         }
 634
 635         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 636 #endif
 637
 638         switch (icp->icmp6_type) {
 639         case ND_ROUTER_SOLICIT:
 640                 /*
 641                  * Message verification - RFC-2461 6.1.1
 642                  * XXX: these checks must be done in the kernel as well,
 643                  *      but we can't completely rely on them.
 644                  */
 645                 if (*hlimp != 255) {
 646                         syslog(LOG_NOTICE,
 647                             "<%s> RS with invalid hop limit(%d) "
 648                             "received from %s on %s",
 649                             __func__, *hlimp,
 650                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 651                             INET6_ADDRSTRLEN),
 652                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 653                         return;
 654                 }
 655                 if (icp->icmp6_code) {
 656                         syslog(LOG_NOTICE,
 657                             "<%s> RS with invalid ICMP6 code(%d) "
 658                             "received from %s on %s",
 659                             __func__, icp->icmp6_code,
 660                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 661                             INET6_ADDRSTRLEN),
 662                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 663                         return;
 664                 }
 665                 if (i < sizeof(struct nd_router_solicit)) {
 666                         syslog(LOG_NOTICE,
 667                             "<%s> RS from %s on %s does not have enough "
 668                             "length (len = %d)",
 669                             __func__,
 670                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 671                             INET6_ADDRSTRLEN),
 672                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 673                         return;
 674                 }
 675                 rs_input(i, (struct nd_router_solicit *)icp, pi, &from);
 676                 break;
 677         case ND_ROUTER_ADVERT:
 678                 /*
 679                  * Message verification - RFC-2461 6.1.2
 680                  * XXX: there's a same dilemma as above...
 681                  */
 682                 if (*hlimp != 255) {
 683                         syslog(LOG_NOTICE,
 684                             "<%s> RA with invalid hop limit(%d) "
 685                             "received from %s on %s",
 686                             __func__, *hlimp,
 687                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 688                             INET6_ADDRSTRLEN),
 689                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 690                         return;
 691                 }
 692                 if (icp->icmp6_code) {
 693                         syslog(LOG_NOTICE,
 694                             "<%s> RA with invalid ICMP6 code(%d) "
 695                             "received from %s on %s",
 696                             __func__, icp->icmp6_code,
 697                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 698                             INET6_ADDRSTRLEN),
 699                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 700                         return;
 701                 }
 702                 if (i < sizeof(struct nd_router_advert)) {
 703                         syslog(LOG_NOTICE,
 704                             "<%s> RA from %s on %s does not have enough "
 705                             "length (len = %d)",
 706                             __func__,
 707                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 708                             INET6_ADDRSTRLEN),
 709                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 710                         return;
 711                 }
 712                 ra_input(i, (struct nd_router_advert *)icp, pi, &from);
 713                 break;
 714         case ICMP6_ROUTER_RENUMBERING:
 715                 if (accept_rr == 0) {
 716                         syslog(LOG_ERR, "<%s> received a router renumbering "
 717                             "message, but not allowed to be accepted",
 718                             __func__);
 719                         break;
 720                 }
 721                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &from,
 722                          &dst);
 723                 break;
 724         default:
 725                 /*
 726                  * Note that this case is POSSIBLE, especially just
 727                  * after invocation of the daemon. This is because we
 728                  * could receive message after opening the socket and
 729                  * before setting ICMP6 type filter(see sock_open()).
 730                  */
 731                 syslog(LOG_ERR, "<%s> invalid icmp type(%d)",
 732                     __func__, icp->icmp6_type);
 733                 return;
 734         }
 735
 736         return;
 737 }
 738
 739 static void
 740 rs_input(int len, struct nd_router_solicit *rs,
 741          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 742 {
 743         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 744         union nd_opts ndopts;
 745         struct rainfo *ra;
 746
 747         syslog(LOG_DEBUG,
 748                "<%s> RS received from %s on %s",
 749                __func__,
 750                inet_ntop(AF_INET6, &from->sin6_addr,
 751                          ntopbuf, INET6_ADDRSTRLEN),
 752                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 753
 754         /* ND option check */
 755         memset(&ndopts, 0, sizeof(ndopts));
 756         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 757                         len - sizeof(struct nd_router_solicit),
 758                          &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 759                 syslog(LOG_DEBUG,
 760                        "<%s> ND option check failed for an RS from %s on %s",
 761                        __func__,
 762                        inet_ntop(AF_INET6, &from->sin6_addr,
 763                                  ntopbuf, INET6_ADDRSTRLEN),
 764                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 765                 return;
 766         }
 767
 768         /*
 769          * If the IP source address is the unspecified address, there
 770          * must be no source link-layer address option in the message.
 771          * (RFC-2461 6.1.1)
 772          */
 773         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 774             ndopts.nd_opts_src_lladdr) {
 775                 syslog(LOG_ERR,
 776                        "<%s> RS from unspecified src on %s has a link-layer"
 777                        " address option",
 778                        __func__,
 779                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 780                 goto done;
 781         }
 782
 783         ra = ralist;
 784         while (ra != NULL) {
 785                 if (pi->ipi6_ifindex == ra->ifindex)
 786                         break;
 787                 ra = ra->next;
 788         }
 789         if (ra == NULL) {
 790                 syslog(LOG_INFO,
 791                        "<%s> RS received on non advertising interface(%s)",
 792                        __func__,
 793                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 794                 goto done;
 795         }
 796
 797         ra->rsinput++;          /* increment statistics */
 798
 799         /*
 800          * Decide whether to send RA according to the rate-limit
 801          * consideration.
 802          */
 803         {
 804                 long delay;     /* must not be greater than 1000000 */
 805                 struct timeval interval, now, min_delay, tm_tmp, *rest;
 806                 struct soliciter *sol;
 807
 808                 /*
 809                  * record sockaddr waiting for RA, if possible
 810                  */
 811                 sol = (struct soliciter *)malloc(sizeof(*sol));
 812                 if (sol) {
 813                         sol->addr = *from;
 814                         /*XXX RFC2553 need clarification on flowinfo */
 815                         sol->addr.sin6_flowinfo = 0;
 816                         sol->next = ra->soliciter;
 817                         ra->soliciter = sol->next;
 818                 }
 819
 820                 /*
 821                  * If there is already a waiting RS packet, don't
 822                  * update the timer.
 823                  */
 824                 if (ra->waiting++)
 825                         goto done;
 826
 827                 /*
 828                  * Compute a random delay. If the computed value
 829                  * corresponds to a time later than the time the next
 830                  * multicast RA is scheduled to be sent, ignore the random
 831                  * delay and send the advertisement at the
 832                  * already-scheduled time. RFC-2461 6.2.6
 833                  */
 834                 delay = random() % MAX_RA_DELAY_TIME;
 835                 interval.tv_sec = 0;
 836                 interval.tv_usec = delay;
 837                 rest = rtadvd_timer_rest(ra->timer);
 838                 if (TIMEVAL_LT(*rest, interval)) {
 839                         syslog(LOG_DEBUG,
 840                                "<%s> random delay is larger than "
 841                                "the rest of normal timer",
 842                                __func__);
 843                         interval = *rest;
 844                 }
 845
 846                 /*
 847                  * If we sent a multicast Router Advertisement within
 848                  * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
 849                  * the advertisement to be sent at a time corresponding to
 850                  * MIN_DELAY_BETWEEN_RAS plus the random value after the
 851                  * previous advertisement was sent.
 852                  */
 853                 gettimeofday(&now, NULL);
 854                 TIMEVAL_SUB(&now, &ra->lastsent, &tm_tmp);
 855                 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
 856                 min_delay.tv_usec = 0;
 857                 if (TIMEVAL_LT(tm_tmp, min_delay)) {
 858                         TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
 859                         TIMEVAL_ADD(&min_delay, &interval, &interval);
 860                 }
 861                 rtadvd_set_timer(&interval, ra->timer);
 862                 goto done;
 863         }
 864
 865   done:
 866         free_ndopts(&ndopts);
 867         return;
 868 }
 869
 870 static void
 871 ra_input(int len, struct nd_router_advert *ra,
 872          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 873 {
 874         struct rainfo *rai;
 875         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 876         union nd_opts ndopts;
 877         char *on_off[] = {"OFF", "ON"};
 878         u_int32_t reachabletime, retranstimer, mtu;
 879         int inconsistent = 0;
 880
 881         syslog(LOG_DEBUG,
 882                "<%s> RA received from %s on %s",
 883                __func__,
 884                inet_ntop(AF_INET6, &from->sin6_addr,
 885                          ntopbuf, INET6_ADDRSTRLEN),
 886                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 887
 888         /* ND option check */
 889         memset(&ndopts, 0, sizeof(ndopts));
 890         if (nd6_options((struct nd_opt_hdr *)(ra + 1),
 891                         len - sizeof(struct nd_router_advert),
 892                         &ndopts, NDOPT_FLAG_SRCLINKADDR |
 893                         NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
 894                 syslog(LOG_ERR,
 895                        "<%s> ND option check failed for an RA from %s on %s",
 896                        __func__,
 897                        inet_ntop(AF_INET6, &from->sin6_addr,
 898                                  ntopbuf, INET6_ADDRSTRLEN),
 899                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 900                 return;
 901         }
 902
 903         /*
 904          * RA consistency check according to RFC-2461 6.2.7
 905          */
 906         if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
 907                 syslog(LOG_INFO,
 908                        "<%s> received RA from %s on non-advertising"
 909                        " interface(%s)",
 910                        __func__,
 911                        inet_ntop(AF_INET6, &from->sin6_addr,
 912                                  ntopbuf, INET6_ADDRSTRLEN),
 913                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 914                 goto done;
 915         }
 916         rai->rainput++;         /* increment statistics */
 917
 918         /* Cur Hop Limit value */
 919         if (ra->nd_ra_curhoplimit && rai->hoplimit &&
 920             ra->nd_ra_curhoplimit != rai->hoplimit) {
 921                 syslog(LOG_INFO,
 922                        "<%s> CurHopLimit inconsistent on %s:"
 923                        " %d from %s, %d from us",
 924                        __func__,
 925                        rai->ifname,
 926                        ra->nd_ra_curhoplimit,
 927                        inet_ntop(AF_INET6, &from->sin6_addr,
 928                                  ntopbuf, INET6_ADDRSTRLEN),
 929                        rai->hoplimit);
 930                 inconsistent++;
 931         }
 932         /* M flag */
 933         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
 934             rai->managedflg) {
 935                 syslog(LOG_INFO,
 936                        "<%s> M flag inconsistent on %s:"
 937                        " %s from %s, %s from us",
 938                        __func__,
 939                        rai->ifname,
 940                        on_off[!rai->managedflg],
 941                        inet_ntop(AF_INET6, &from->sin6_addr,
 942                                  ntopbuf, INET6_ADDRSTRLEN),
 943                        on_off[rai->managedflg]);
 944                 inconsistent++;
 945         }
 946         /* O flag */
 947         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
 948             rai->otherflg) {
 949                 syslog(LOG_INFO,
 950                        "<%s> O flag inconsistent on %s:"
 951                        " %s from %s, %s from us",
 952                        __func__,
 953                        rai->ifname,
 954                        on_off[!rai->otherflg],
 955                        inet_ntop(AF_INET6, &from->sin6_addr,
 956                                  ntopbuf, INET6_ADDRSTRLEN),
 957                        on_off[rai->otherflg]);
 958                 inconsistent++;
 959         }
 960         /* Reachable Time */
 961         reachabletime = ntohl(ra->nd_ra_reachable);
 962         if (reachabletime && rai->reachabletime &&
 963             reachabletime != rai->reachabletime) {
 964                 syslog(LOG_INFO,
 965                        "<%s> ReachableTime inconsistent on %s:"
 966                        " %d from %s, %d from us",
 967                        __func__,
 968                        rai->ifname,
 969                        reachabletime,
 970                        inet_ntop(AF_INET6, &from->sin6_addr,
 971                                  ntopbuf, INET6_ADDRSTRLEN),
 972                        rai->reachabletime);
 973                 inconsistent++;
 974         }
 975         /* Retrans Timer */
 976         retranstimer = ntohl(ra->nd_ra_retransmit);
 977         if (retranstimer && rai->retranstimer &&
 978             retranstimer != rai->retranstimer) {
 979                 syslog(LOG_INFO,
 980                        "<%s> RetranceTimer inconsistent on %s:"
 981                        " %d from %s, %d from us",
 982                        __func__,
 983                        rai->ifname,
 984                        retranstimer,
 985                        inet_ntop(AF_INET6, &from->sin6_addr,
 986                                  ntopbuf, INET6_ADDRSTRLEN),
 987                        rai->retranstimer);
 988                 inconsistent++;
 989         }
 990         /* Values in the MTU options */
 991         if (ndopts.nd_opts_mtu) {
 992                 mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
 993                 if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
 994                         syslog(LOG_INFO,
 995                                "<%s> MTU option value inconsistent on %s:"
 996                                " %d from %s, %d from us",
 997                                __func__,
 998                                rai->ifname, mtu,
 999                                inet_ntop(AF_INET6, &from->sin6_addr,
1000                                          ntopbuf, INET6_ADDRSTRLEN),
1001                                rai->linkmtu);
1002                         inconsistent++;
1003                 }
1004         }
1005         /* Preferred and Valid Lifetimes for prefixes */
1006         {
1007                 struct nd_optlist *optp = ndopts.nd_opts_list;
1008
1009                 if (ndopts.nd_opts_pi) {
1010                         if (prefix_check(ndopts.nd_opts_pi, rai, from))
1011                                 inconsistent++;
1012                 }
1013                 while (optp) {
1014                         if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
1015                                          rai, from))
1016                                 inconsistent++;
1017                         optp = optp->next;
1018                 }
1019         }
1020
1021         if (inconsistent)
1022                 rai->rainconsistent++;
1023
1024   done:
1025         free_ndopts(&ndopts);
1026         return;
1027 }
1028
1029 /* return a non-zero value if the received prefix is inconsitent with ours */
1030 static int
1031 prefix_check(struct nd_opt_prefix_info *pinfo,
1032              struct rainfo *rai, struct sockaddr_in6 *from)
1033 {
1034         u_int32_t preferred_time, valid_time;
1035         struct prefix *pp;
1036         int inconsistent = 0;
1037         u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
1038         struct timeval now;
1039
1040 #if 0                           /* impossible */
1041         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1042                 return(0);
1043 #endif
1044
1045         /*
1046          * log if the adveritsed prefix has link-local scope(sanity check?)
1047          */
1048         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
1049                 syslog(LOG_INFO,
1050                        "<%s> link-local prefix %s/%d is advertised "
1051                        "from %s on %s",
1052                        __func__,
1053                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1054                                  prefixbuf, INET6_ADDRSTRLEN),
1055                        pinfo->nd_opt_pi_prefix_len,
1056                        inet_ntop(AF_INET6, &from->sin6_addr,
1057                                  ntopbuf, INET6_ADDRSTRLEN),
1058                        rai->ifname);
1059         }
1060
1061         if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1062                               pinfo->nd_opt_pi_prefix_len)) == NULL) {
1063                 syslog(LOG_INFO,
1064                        "<%s> prefix %s/%d from %s on %s is not in our list",
1065                        __func__,
1066                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1067                                  prefixbuf, INET6_ADDRSTRLEN),
1068                        pinfo->nd_opt_pi_prefix_len,
1069                        inet_ntop(AF_INET6, &from->sin6_addr,
1070                                  ntopbuf, INET6_ADDRSTRLEN),
1071                        rai->ifname);
1072                 return(0);
1073         }
1074
1075         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1076         if (pp->pltimeexpire) {
1077                 /*
1078                  * The lifetime is decremented in real time, so we should
1079                  * compare the expiration time.
1080                  * (RFC 2461 Section 6.2.7.)
1081                  * XXX: can we really expect that all routers on the link
1082                  * have synchronized clocks?
1083                  */
1084                 gettimeofday(&now, NULL);
1085                 preferred_time += now.tv_sec;
1086
1087                 if (rai->clockskew &&
1088                     abs(preferred_time - pp->pltimeexpire) > rai->clockskew) {
1089                         syslog(LOG_INFO,
1090                                "<%s> prefeerred lifetime for %s/%d"
1091                                " (decr. in real time) inconsistent on %s:"
1092                                " %d from %s, %ld from us",
1093                                __func__,
1094                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1095                                          prefixbuf, INET6_ADDRSTRLEN),
1096                                pinfo->nd_opt_pi_prefix_len,
1097                                rai->ifname, preferred_time,
1098                                inet_ntop(AF_INET6, &from->sin6_addr,
1099                                          ntopbuf, INET6_ADDRSTRLEN),
1100                                pp->pltimeexpire);
1101                         inconsistent++;
1102                 }
1103         } else if (preferred_time != pp->preflifetime) {
1104                 syslog(LOG_INFO,
1105                        "<%s> prefeerred lifetime for %s/%d"
1106                        " inconsistent on %s:"
1107                        " %d from %s, %d from us",
1108                        __func__,
1109                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1110                                  prefixbuf, INET6_ADDRSTRLEN),
1111                        pinfo->nd_opt_pi_prefix_len,
1112                        rai->ifname, preferred_time,
1113                        inet_ntop(AF_INET6, &from->sin6_addr,
1114                                  ntopbuf, INET6_ADDRSTRLEN),
1115                        pp->preflifetime);
1116         }
1117
1118         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1119         if (pp->vltimeexpire) {
1120                 gettimeofday(&now, NULL);
1121                 valid_time += now.tv_sec;
1122
1123                 if (rai->clockskew &&
1124                     abs(valid_time - pp->vltimeexpire) > rai->clockskew) {
1125                         syslog(LOG_INFO,
1126                                "<%s> valid lifetime for %s/%d"
1127                                " (decr. in real time) inconsistent on %s:"
1128                                " %d from %s, %ld from us",
1129                                __func__,
1130                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1131                                          prefixbuf, INET6_ADDRSTRLEN),
1132                                pinfo->nd_opt_pi_prefix_len,
1133                                rai->ifname, preferred_time,
1134                                inet_ntop(AF_INET6, &from->sin6_addr,
1135                                          ntopbuf, INET6_ADDRSTRLEN),
1136                                pp->vltimeexpire);
1137                         inconsistent++;
1138                 }
1139         } else if (valid_time != pp->validlifetime) {
1140                 syslog(LOG_INFO,
1141                        "<%s> valid lifetime for %s/%d"
1142                        " inconsistent on %s:"
1143                        " %d from %s, %d from us",
1144                        __func__,
1145                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1146                                  prefixbuf, INET6_ADDRSTRLEN),
1147                        pinfo->nd_opt_pi_prefix_len,
1148                        rai->ifname, valid_time,
1149                        inet_ntop(AF_INET6, &from->sin6_addr,
1150                                  ntopbuf, INET6_ADDRSTRLEN),
1151                        pp->validlifetime);
1152                 inconsistent++;
1153         }
1154
1155         return(inconsistent);
1156 }
1157
1158 struct prefix *
1159 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1160 {
1161         struct prefix *pp;
1162         int bytelen, bitlen;
1163
1164         for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
1165                 if (plen != pp->prefixlen)
1166                         continue;
1167                 bytelen = plen / 8;
1168                 bitlen = plen % 8;
1169                 if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1170                         continue;
1171                 if (prefix->s6_addr[bytelen] >> (8 - bitlen) ==
1172                     pp->prefix.s6_addr[bytelen] >> (8 - bitlen))
1173                         return(pp);
1174         }
1175
1176         return(NULL);
1177 }
1178
1179 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1180 int
1181 prefix_match(struct in6_addr *p0, int plen0,
1182              struct in6_addr *p1, int plen1)
1183 {
1184         int bytelen, bitlen;
1185
1186         if (plen0 < plen1)
1187                 return(0);
1188         bytelen = plen1 / 8;
1189         bitlen = plen1 % 8;
1190         if (memcmp((void *)p0, (void *)p1, bytelen))
1191                 return(0);
1192         if (p0->s6_addr[bytelen] >> (8 - bitlen) ==
1193             p1->s6_addr[bytelen] >> (8 - bitlen))
1194                 return(1);
1195
1196         return(0);
1197 }
1198
1199 static int
1200 nd6_options(struct nd_opt_hdr *hdr, int limit,
1201             union nd_opts *ndopts, u_int32_t optflags)
1202 {
1203         int optlen = 0;
1204
1205         for (; limit > 0; limit -= optlen) {
1206                 if (limit < sizeof(struct nd_opt_hdr)) {
1207                         syslog(LOG_INFO, "<%s> short option header", __func__);
1208                         goto bad;
1209                 }
1210
1211                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1212                 if (hdr->nd_opt_len == 0) {
1213                         syslog(LOG_INFO,
1214                             "<%s> bad ND option length(0) (type = %d)",
1215                             __func__, hdr->nd_opt_type);
1216                         goto bad;
1217                 }
1218                 optlen = hdr->nd_opt_len << 3;
1219                 if (optlen > limit) {
1220                         syslog(LOG_INFO, "<%s> short option", __func__);
1221                         goto bad;
1222                 }
1223
1224                 if (hdr->nd_opt_type > ND_OPT_MTU) {
1225                         syslog(LOG_INFO,
1226                             "<%s> unknown ND option(type %d)",
1227                             __func__, hdr->nd_opt_type);
1228                         continue;
1229                 }
1230
1231                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1232                         syslog(LOG_INFO,
1233                             "<%s> unexpected ND option(type %d)",
1234                                __func__, hdr->nd_opt_type);
1235                         continue;
1236                 }
1237
1238                 /*
1239                  * Option length check.  Do it here for all fixed-length
1240                  * options.
1241                  */
1242                 if ((hdr->nd_opt_type == ND_OPT_MTU &&
1243                     (optlen != sizeof(struct nd_opt_mtu))) ||
1244                     ((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION &&
1245                     optlen != sizeof(struct nd_opt_prefix_info)))) {
1246                         syslog(LOG_INFO, "<%s> invalid option length",
1247                             __func__);
1248                         continue;
1249                 }
1250
1251                 switch (hdr->nd_opt_type) {
1252                 case ND_OPT_SOURCE_LINKADDR:
1253                 case ND_OPT_TARGET_LINKADDR:
1254                 case ND_OPT_REDIRECTED_HEADER:
1255                         break;  /* we don't care about these options */
1256                 case ND_OPT_MTU:
1257                         if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1258                                 syslog(LOG_INFO,
1259                                     "<%s> duplicated ND option (type = %d)",
1260                                     __func__, hdr->nd_opt_type);
1261                         }
1262                         ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1263                         break;
1264                 case ND_OPT_PREFIX_INFORMATION:
1265                 {
1266                         struct nd_optlist *pfxlist;
1267
1268                         if (ndopts->nd_opts_pi == 0) {
1269                                 ndopts->nd_opts_pi =
1270                                     (struct nd_opt_prefix_info *)hdr;
1271                                 continue;
1272                         }
1273                         if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1274                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1275                                     __func__);
1276                                 goto bad;
1277                         }
1278                         pfxlist->next = ndopts->nd_opts_list;
1279                         pfxlist->opt = hdr;
1280                         ndopts->nd_opts_list = pfxlist;
1281
1282                         break;
1283                 }
1284                 default:        /* impossible */
1285                         break;
1286                 }
1287         }
1288
1289         return(0);
1290
1291   bad:
1292         free_ndopts(ndopts);
1293
1294         return(-1);
1295 }
1296
1297 static void
1298 free_ndopts(union nd_opts *ndopts)
1299 {
1300         struct nd_optlist *opt = ndopts->nd_opts_list, *next;
1301
1302         while (opt) {
1303                 next = opt->next;
1304                 free(opt);
1305                 opt = next;
1306         }
1307 }
1308
1309 void
1310 sock_open(void)
1311 {
1312         struct icmp6_filter filt;
1313         struct ipv6_mreq mreq;
1314         struct rainfo *ra = ralist;
1315         int on;
1316         /* XXX: should be max MTU attached to the node */
1317         static u_char answer[1500];
1318
1319         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1320                                 CMSG_SPACE(sizeof(int));
1321         rcvcmsgbuf = (u_char *)malloc(rcvcmsgbuflen);
1322         if (rcvcmsgbuf == NULL) {
1323                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1324                 exit(1);
1325         }
1326
1327         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1328                                 CMSG_SPACE(sizeof(int));
1329         sndcmsgbuf = (u_char *)malloc(sndcmsgbuflen);
1330         if (sndcmsgbuf == NULL) {
1331                 syslog(LOG_ERR, "<%s> not enough core", __func__);
1332                 exit(1);
1333         }
1334
1335         if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1336                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
1337                        strerror(errno));
1338                 exit(1);
1339         }
1340
1341         /* specify to tell receiving interface */
1342         on = 1;
1343 #ifdef IPV6_RECVPKTINFO
1344         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1345                        sizeof(on)) < 0) {
1346                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
1347                        __func__, strerror(errno));
1348                 exit(1);
1349         }
1350 #else  /* old adv. API */
1351         if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1352                        sizeof(on)) < 0) {
1353                 syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
1354                        __func__, strerror(errno));
1355                 exit(1);
1356         }
1357 #endif
1358
1359         on = 1;
1360         /* specify to tell value of hoplimit field of received IP6 hdr */
1361 #ifdef IPV6_RECVHOPLIMIT
1362         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1363                        sizeof(on)) < 0) {
1364                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
1365                        __func__, strerror(errno));
1366                 exit(1);
1367         }
1368 #else  /* old adv. API */
1369         if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1370                        sizeof(on)) < 0) {
1371                 syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
1372                        __func__, strerror(errno));
1373                 exit(1);
1374         }
1375 #endif
1376
1377         ICMP6_FILTER_SETBLOCKALL(&filt);
1378         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1379         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1380         if (accept_rr)
1381                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1382         if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1383                        sizeof(filt)) < 0) {
1384                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1385                        __func__, strerror(errno));
1386                 exit(1);
1387         }
1388
1389         /*
1390          * join all routers multicast address on each advertising interface.
1391          */
1392         if (inet_pton(AF_INET6, ALLROUTERS_LINK,
1393                       &mreq.ipv6mr_multiaddr.s6_addr)
1394             != 1) {
1395                 syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1396                        __func__);
1397                 exit(1);
1398         }
1399         while (ra) {
1400                 mreq.ipv6mr_interface = ra->ifindex;
1401                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
1402                                sizeof(mreq)) < 0) {
1403                         syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP(link) on %s: %s",
1404                                __func__, ra->ifname, strerror(errno));
1405                         exit(1);
1406                 }
1407                 ra = ra->next;
1408         }
1409
1410         /*
1411          * When attending router renumbering, join all-routers site-local
1412          * multicast group.
1413          */
1414         if (accept_rr) {
1415                 if (inet_pton(AF_INET6, ALLROUTERS_SITE,
1416                               &in6a_site_allrouters) != 1) {
1417                         syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1418                                __func__);
1419                         exit(1);
1420                 }
1421                 mreq.ipv6mr_multiaddr = in6a_site_allrouters;
1422                 if (mcastif) {
1423                         if ((mreq.ipv6mr_interface = if_nametoindex(mcastif))
1424                             == 0) {
1425                                 syslog(LOG_ERR,
1426                                        "<%s> invalid interface: %s",
1427                                        __func__, mcastif);
1428                                 exit(1);
1429                         }
1430                 } else
1431                         mreq.ipv6mr_interface = ralist->ifindex;
1432                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1433                                &mreq, sizeof(mreq)) < 0) {
1434                         syslog(LOG_ERR,
1435                                "<%s> IPV6_JOIN_GROUP(site) on %s: %s",
1436                                __func__,
1437                                mcastif ? mcastif : ralist->ifname,
1438                                strerror(errno));
1439                         exit(1);
1440                 }
1441         }
1442
1443         /* initialize msghdr for receiving packets */
1444         rcviov[0].iov_base = (caddr_t)answer;
1445         rcviov[0].iov_len = sizeof(answer);
1446         rcvmhdr.msg_name = (caddr_t)&from;
1447         rcvmhdr.msg_namelen = sizeof(from);
1448         rcvmhdr.msg_iov = rcviov;
1449         rcvmhdr.msg_iovlen = 1;
1450         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1451         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1452
1453         /* initialize msghdr for sending packets */
1454         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1455         sndmhdr.msg_iov = sndiov;
1456         sndmhdr.msg_iovlen = 1;
1457         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1458         sndmhdr.msg_controllen = sndcmsgbuflen;
1459
1460         return;
1461 }
1462
1463 /* open a routing socket to watch the routing table */
1464 static void
1465 rtsock_open(void)
1466 {
1467         if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1468                 syslog(LOG_ERR,
1469                        "<%s> socket: %s", __func__, strerror(errno));
1470                 exit(1);
1471         }
1472 }
1473
1474 struct rainfo *
1475 if_indextorainfo(int index)
1476 {
1477         struct rainfo *rai = ralist;
1478
1479         for (rai = ralist; rai; rai = rai->next) {
1480                 if (rai->ifindex == index)
1481                         return(rai);
1482         }
1483
1484         return(NULL);           /* search failed */
1485 }
1486
1487 static void
1488 ra_output(struct rainfo *rainfo)
1489 {
1490         int i;
1491         struct cmsghdr *cm;
1492         struct in6_pktinfo *pi;
1493         struct soliciter *sol, *nextsol;
1494
1495         if ((iflist[rainfo->ifindex]->ifm_flags & IFF_UP) == 0) {
1496                 syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1497                        __func__, rainfo->ifname);
1498                 return;
1499         }
1500
1501         make_packet(rainfo);    /* XXX: inefficient */
1502
1503         sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
1504         sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
1505         sndmhdr.msg_iov[0].iov_len = rainfo->ra_datalen;
1506
1507         cm = CMSG_FIRSTHDR(&sndmhdr);
1508         /* specify the outgoing interface */
1509         cm->cmsg_level = IPPROTO_IPV6;
1510         cm->cmsg_type = IPV6_PKTINFO;
1511         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1512         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1513         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1514         pi->ipi6_ifindex = rainfo->ifindex;
1515
1516         /* specify the hop limit of the packet */
1517         {
1518                 int hoplimit = 255;
1519
1520                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1521                 cm->cmsg_level = IPPROTO_IPV6;
1522                 cm->cmsg_type = IPV6_HOPLIMIT;
1523                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1524                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1525         }
1526
1527         syslog(LOG_DEBUG,
1528                "<%s> send RA on %s, # of waitings = %d",
1529                __func__, rainfo->ifname, rainfo->waiting);
1530
1531         i = sendmsg(sock, &sndmhdr, 0);
1532
1533         if (i < 0 || i != rainfo->ra_datalen)  {
1534                 if (i < 0) {
1535                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1536                                __func__, rainfo->ifname,
1537                                strerror(errno));
1538                 }
1539         }
1540
1541         /*
1542          * unicast advertisements
1543          * XXX commented out.  reason: though spec does not forbit it, unicast
1544          * advert does not really help
1545          */
1546         for (sol = rainfo->soliciter; sol; sol = nextsol) {
1547                 nextsol = sol->next;
1548
1549 #if 0
1550                 sndmhdr.msg_name = (caddr_t)&sol->addr;
1551                 i = sendmsg(sock, &sndmhdr, 0);
1552                 if (i < 0 || i != rainfo->ra_datalen)  {
1553                         if (i < 0) {
1554                                 syslog(LOG_ERR,
1555                                     "<%s> unicast sendmsg on %s: %s",
1556                                     __func__, rainfo->ifname,
1557                                     strerror(errno));
1558                         }
1559                 }
1560 #endif
1561
1562                 sol->next = NULL;
1563                 free(sol);
1564         }
1565         rainfo->soliciter = NULL;
1566
1567         /* update counter */
1568         if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1569                 rainfo->initcounter++;
1570         rainfo->raoutput++;
1571
1572         /* update timestamp */
1573         gettimeofday(&rainfo->lastsent, NULL);
1574
1575         /* reset waiting conter */
1576         rainfo->waiting = 0;
1577 }
1578
1579 /* process RA timer */
1580 struct rtadvd_timer *
1581 ra_timeout(void *data)
1582 {
1583         struct rainfo *rai = (struct rainfo *)data;
1584
1585 #ifdef notyet
1586         /* if necessary, reconstruct the packet. */
1587 #endif
1588
1589         syslog(LOG_DEBUG,
1590                "<%s> RA timer on %s is expired",
1591                __func__, rai->ifname);
1592
1593         ra_output(rai);
1594
1595         return(rai->timer);
1596 }
1597
1598 /* update RA timer */
1599 void
1600 ra_timer_update(void *data, struct timeval *tm)
1601 {
1602         struct rainfo *rai = (struct rainfo *)data;
1603         long interval;
1604
1605         /*
1606          * Whenever a multicast advertisement is sent from an interface,
1607          * the timer is reset to a uniformly-distributed random value
1608          * between the interface's configured MinRtrAdvInterval and
1609          * MaxRtrAdvInterval (RFC2461 6.2.4).
1610          */
1611         interval = rai->mininterval;
1612         interval += random() % (rai->maxinterval - rai->mininterval);
1613
1614         /*
1615          * For the first few advertisements (up to
1616          * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1617          * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1618          * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1619          * (RFC-2461 6.2.4)
1620          */
1621         if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1622             interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1623                 interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1624
1625         tm->tv_sec = interval;
1626         tm->tv_usec = 0;
1627
1628         syslog(LOG_DEBUG,
1629                "<%s> RA timer on %s is set to %ld:%ld",
1630                __func__, rai->ifname,
1631                (long int)tm->tv_sec, (long int)tm->tv_usec);
1632
1633         return;
1634 }