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 __P((int, char *[]));
 129 static void set_die __P((int));
 130 static void die __P((void));
 131 static void sock_open __P((void));
 132 static void rtsock_open __P((void));
 133 static void rtadvd_input __P((void));
 134 static void rs_input __P((int, struct nd_router_solicit *,
 135                           struct in6_pktinfo *, struct sockaddr_in6 *));
 136 static void ra_input __P((int, struct nd_router_advert *,
 137                           struct in6_pktinfo *, struct sockaddr_in6 *));
 138 static int prefix_check __P((struct nd_opt_prefix_info *, struct rainfo *,
 139                              struct sockaddr_in6 *));
 140 static int nd6_options __P((struct nd_opt_hdr *, int,
 141                             union nd_opts *, u_int32_t));
 142 static void free_ndopts __P((union nd_opts *));
 143 static void ra_output __P((struct rainfo *));
 144 static void rtmsg_input __P((void));
 145 static void rtadvd_set_dump_file __P((void));
 146
 147 int
 148 main(argc, argv)
 149         int argc;
 150         char *argv[];
 151 {
 152         fd_set fdset;
 153         int maxfd = 0;
 154         struct timeval *timeout;
 155         int i, ch;
 156         int fflag = 0;
 157         FILE *pidfp;
 158         pid_t pid;
 159
 160         openlog("rtadvd", LOG_NDELAY|LOG_PID, LOG_DAEMON);
 161
 162         /* get command line options and arguments */
 163 #ifdef MIP6
 164 #define OPTIONS "c:dDfM:mRs"
 165 #else
 166 #define OPTIONS "c:dDfM:Rs"
 167 #endif
 168         while ((ch = getopt(argc, argv, OPTIONS)) != -1) {
 169 #undef OPTIONS
 170                 switch (ch) {
 171                 case 'c':
 172                         conffile = optarg;
 173                         break;
 174                 case 'd':
 175                         dflag = 1;
 176                         break;
 177                 case 'D':
 178                         dflag = 2;
 179                         break;
 180                 case 'f':
 181                         fflag = 1;
 182                         break;
 183                 case 'M':
 184                         mcastif = optarg;
 185                         break;
 186 #ifdef MIP6
 187                 case 'm':
 188                         mobileip6 = 1;
 189                         break;
 190 #endif
 191                 case 'R':
 192                         fprintf(stderr, "rtadvd: "
 193                                 "the -R option is currently ignored.\n");
 194                         /* accept_rr = 1; */
 195                         /* run anyway... */
 196                         break;
 197                 case 's':
 198                         sflag = 1;
 199                         break;
 200                 }
 201         }
 202         argc -= optind;
 203         argv += optind;
 204         if (argc == 0) {
 205                 fprintf(stderr,
 206 #ifdef MIP6
 207                         "usage: rtadvd [-dDfMmRs] [-c conffile] "
 208 #else
 209                         "usage: rtadvd [-dDfMRs] [-c conffile] "
 210 #endif
 211                         "interfaces...\n");
 212                 exit(1);
 213         }
 214
 215         /* set log level */
 216         if (dflag == 0)
 217                 (void)setlogmask(LOG_UPTO(LOG_ERR));
 218         if (dflag == 1)
 219                 (void)setlogmask(LOG_UPTO(LOG_INFO));
 220
 221         /* timer initialization */
 222         rtadvd_timer_init();
 223
 224         /* random value initialization */
 225         srandom((u_long)time(NULL));
 226
 227         /* get iflist block from kernel */
 228         init_iflist();
 229
 230         while (argc--)
 231                 getconfig(*argv++);
 232
 233         if (inet_pton(AF_INET6, ALLNODES, &sin6_allnodes.sin6_addr) != 1) {
 234                 fprintf(stderr, "fatal: inet_pton failed\n");
 235                 exit(1);
 236         }
 237         sock_open();
 238
 239         if (!fflag)
 240                 daemon(1, 0);
 241
 242         /* record the current PID */
 243         pid = getpid();
 244         if ((pidfp = fopen(pidfilename, "w")) == NULL) {
 245                 syslog(LOG_ERR,
 246                     "<%s> failed to open a log file(%s), run anyway.",
 247                     __FUNCTION__, pidfilename);
 248         } else {
 249                 fprintf(pidfp, "%d\n", pid);
 250                 fclose(pidfp);
 251         }
 252
 253         FD_ZERO(&fdset);
 254         FD_SET(sock, &fdset);
 255         maxfd = sock;
 256         if (sflag == 0) {
 257                 rtsock_open();
 258                 FD_SET(rtsock, &fdset);
 259                 if (rtsock > sock)
 260                         maxfd = rtsock;
 261         } else
 262                 rtsock = -1;
 263
 264         signal(SIGTERM, (void *)set_die);
 265         signal(SIGUSR1, (void *)rtadvd_set_dump_file);
 266
 267         while (1) {
 268                 struct fd_set select_fd = fdset; /* reinitialize */
 269
 270                 if (do_dump) {  /* SIGUSR1 */
 271                         do_dump = 0;
 272                         rtadvd_dump_file(dumpfilename);
 273                 }
 274
 275                 if (do_die) {
 276                         die();
 277                         /*NOTREACHED*/
 278                 }
 279
 280                 /* timer expiration check and reset the timer */
 281                 timeout = rtadvd_check_timer();
 282
 283                 if (timeout != NULL) {
 284                         syslog(LOG_DEBUG,
 285                             "<%s> set timer to %ld:%ld. waiting for "
 286                             "inputs or timeout", __FUNCTION__,
 287                             (long int)timeout->tv_sec,
 288                             (long int)timeout->tv_usec);
 289                 } else {
 290                         syslog(LOG_DEBUG,
 291                             "<%s> there's no timer. waiting for inputs",
 292                             __FUNCTION__);
 293                 }
 294
 295                 if ((i = select(maxfd + 1, &select_fd,
 296                                 NULL, NULL, timeout)) < 0) {
 297                         /* EINTR would occur upon SIGUSR1 for status dump */
 298                         if (errno != EINTR)
 299                                 syslog(LOG_ERR, "<%s> select: %s",
 300                                     __FUNCTION__, strerror(errno));
 301                         continue;
 302                 }
 303                 if (i == 0)     /* timeout */
 304                         continue;
 305                 if (rtsock != -1 && FD_ISSET(rtsock, &select_fd))
 306                         rtmsg_input();
 307                 if (FD_ISSET(sock, &select_fd))
 308                         rtadvd_input();
 309         }
 310         exit(0);                /* NOTREACHED */
 311 }
 312
 313 static void
 314 rtadvd_set_dump_file()
 315 {
 316         do_dump = 1;
 317 }
 318
 319 static void
 320 set_die(sig)
 321         int sig;
 322 {
 323         do_die = 1;
 324 }
 325
 326 static void
 327 die()
 328 {
 329         struct rainfo *ra;
 330         int i;
 331         const int retrans = MAX_FINAL_RTR_ADVERTISEMENTS;
 332
 333         if (dflag > 1) {
 334                 syslog(LOG_DEBUG, "<%s> cease to be an advertising router\n",
 335                     __FUNCTION__);
 336         }
 337
 338         for (ra = ralist; ra; ra = ra->next) {
 339                 ra->lifetime = 0;
 340                 make_packet(ra);
 341         }
 342         for (i = 0; i < retrans; i++) {
 343                 for (ra = ralist; ra; ra = ra->next)
 344                         ra_output(ra);
 345                 sleep(MIN_DELAY_BETWEEN_RAS);
 346         }
 347         exit(0);
 348         /*NOTREACHED*/
 349 }
 350
 351 static void
 352 rtmsg_input()
 353 {
 354         int n, type, ifindex = 0, plen;
 355         size_t len;
 356         char msg[2048], *next, *lim;
 357         u_char ifname[IF_NAMESIZE];
 358         struct prefix *prefix;
 359         struct rainfo *rai;
 360         struct in6_addr *addr;
 361         char addrbuf[INET6_ADDRSTRLEN];
 362
 363         n = read(rtsock, msg, sizeof(msg));
 364         if (dflag > 1) {
 365                 syslog(LOG_DEBUG, "<%s> received a routing message "
 366                     "(type = %d, len = %d)", __FUNCTION__, rtmsg_type(msg), n);
 367         }
 368         if (n > rtmsg_len(msg)) {
 369                 /*
 370                  * This usually won't happen for messages received on
 371                  * a routing socket.
 372                  */
 373                 if (dflag > 1)
 374                         syslog(LOG_DEBUG,
 375                             "<%s> received data length is larger than "
 376                             "1st routing message len. multiple messages? "
 377                             "read %d bytes, but 1st msg len = %d",
 378                             __FUNCTION__, n, rtmsg_len(msg));
 379 #if 0
 380                 /* adjust length */
 381                 n = rtmsg_len(msg);
 382 #endif
 383         }
 384
 385         lim = msg + n;
 386         for (next = msg; next < lim; next += len) {
 387                 int oldifflags;
 388
 389                 next = get_next_msg(next, lim, 0, &len,
 390                                     RTADV_TYPE2BITMASK(RTM_ADD) |
 391                                     RTADV_TYPE2BITMASK(RTM_DELETE) |
 392                                     RTADV_TYPE2BITMASK(RTM_NEWADDR) |
 393                                     RTADV_TYPE2BITMASK(RTM_DELADDR) |
 394                                     RTADV_TYPE2BITMASK(RTM_IFINFO));
 395                 if (len == 0)
 396                         break;
 397                 type = rtmsg_type(next);
 398                 switch (type) {
 399                 case RTM_ADD:
 400                 case RTM_DELETE:
 401                         ifindex = get_rtm_ifindex(next);
 402                         break;
 403                 case RTM_NEWADDR:
 404                 case RTM_DELADDR:
 405                         ifindex = get_ifam_ifindex(next);
 406                         break;
 407                 case RTM_IFINFO:
 408                         ifindex = get_ifm_ifindex(next);
 409                         break;
 410                 default:
 411                         /* should not reach here */
 412                         if (dflag > 1) {
 413                                 syslog(LOG_DEBUG,
 414                                        "<%s:%d> unknown rtmsg %d on %s",
 415                                        __FUNCTION__, __LINE__, type,
 416                                        if_indextoname(ifindex, ifname));
 417                         }
 418                         continue;
 419                 }
 420
 421                 if ((rai = if_indextorainfo(ifindex)) == NULL) {
 422                         if (dflag > 1) {
 423                                 syslog(LOG_DEBUG,
 424                                        "<%s> route changed on "
 425                                        "non advertising interface(%s)",
 426                                        __FUNCTION__,
 427                                        if_indextoname(ifindex, ifname));
 428                         }
 429                         continue;
 430                 }
 431                 oldifflags = iflist[ifindex]->ifm_flags;
 432
 433                 switch (type) {
 434                 case RTM_ADD:
 435                         /* init ifflags because it may have changed */
 436                         iflist[ifindex]->ifm_flags =
 437                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 438
 439                         if (sflag)
 440                                 break;  /* we aren't interested in prefixes  */
 441
 442                         addr = get_addr(msg);
 443                         plen = get_prefixlen(msg);
 444                         /* sanity check for plen */
 445                         /* as RFC2373, prefixlen is at least 4 */
 446                         if (plen < 4 || plen > 127) {
 447                                 syslog(LOG_INFO, "<%s> new interface route's"
 448                                     "plen %d is invalid for a prefix",
 449                                     __FUNCTION__, plen);
 450                                 break;
 451                         }
 452                         prefix = find_prefix(rai, addr, plen);
 453                         if (prefix) {
 454                                 if (prefix->timer) {
 455                                         /*
 456                                          * If the prefix has been invalidated,
 457                                          * make it available again.
 458                                          */
 459                                         update_prefix(prefix);
 460                                 } else if (dflag > 1) {
 461                                         syslog(LOG_DEBUG,
 462                                             "<%s> new prefix(%s/%d) "
 463                                             "added on %s, "
 464                                             "but it was already in list",
 465                                             __FUNCTION__,
 466                                             inet_ntop(AF_INET6, addr,
 467                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 468                                             plen, rai->ifname);
 469                                 }
 470                                 break;
 471                         }
 472                         make_prefix(rai, ifindex, addr, plen);
 473                         break;
 474                 case RTM_DELETE:
 475                         /* init ifflags because it may have changed */
 476                         iflist[ifindex]->ifm_flags =
 477                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 478
 479                         if (sflag)
 480                                 break;
 481
 482                         addr = get_addr(msg);
 483                         plen = get_prefixlen(msg);
 484                         /* sanity check for plen */
 485                         /* as RFC2373, prefixlen is at least 4 */
 486                         if (plen < 4 || plen > 127) {
 487                                 syslog(LOG_INFO,
 488                                     "<%s> deleted interface route's "
 489                                     "plen %d is invalid for a prefix",
 490                                     __FUNCTION__, plen);
 491                                 break;
 492                         }
 493                         prefix = find_prefix(rai, addr, plen);
 494                         if (prefix == NULL) {
 495                                 if (dflag > 1) {
 496                                         syslog(LOG_DEBUG,
 497                                             "<%s> prefix(%s/%d) was "
 498                                             "deleted on %s, "
 499                                             "but it was not in list",
 500                                             __FUNCTION__,
 501                                             inet_ntop(AF_INET6, addr,
 502                                             (char *)addrbuf, INET6_ADDRSTRLEN),
 503                                             plen, rai->ifname);
 504                                 }
 505                                 break;
 506                         }
 507                         invalidate_prefix(prefix);
 508                         break;
 509                 case RTM_NEWADDR:
 510                 case RTM_DELADDR:
 511                         /* init ifflags because it may have changed */
 512                         iflist[ifindex]->ifm_flags =
 513                             if_getflags(ifindex, iflist[ifindex]->ifm_flags);
 514                         break;
 515                 case RTM_IFINFO:
 516                         iflist[ifindex]->ifm_flags = get_ifm_flags(next);
 517                         break;
 518                 default:
 519                         /* should not reach here */
 520                         if (dflag > 1) {
 521                                 syslog(LOG_DEBUG,
 522                                     "<%s:%d> unknown rtmsg %d on %s",
 523                                     __FUNCTION__, __LINE__, type,
 524                                     if_indextoname(ifindex, ifname));
 525                         }
 526                         return;
 527                 }
 528
 529                 /* check if an interface flag is changed */
 530                 if ((oldifflags & IFF_UP) != 0 &&       /* UP to DOWN */
 531                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0) {
 532                         syslog(LOG_INFO,
 533                             "<%s> interface %s becomes down. stop timer.",
 534                             __FUNCTION__, rai->ifname);
 535                         rtadvd_remove_timer(&rai->timer);
 536                 } else if ((oldifflags & IFF_UP) == 0 &&        /* DOWN to UP */
 537                          (iflist[ifindex]->ifm_flags & IFF_UP) != 0) {
 538                         syslog(LOG_INFO,
 539                             "<%s> interface %s becomes up. restart timer.",
 540                             __FUNCTION__, rai->ifname);
 541
 542                         rai->initcounter = 0; /* reset the counter */
 543                         rai->waiting = 0; /* XXX */
 544                         rai->timer = rtadvd_add_timer(ra_timeout,
 545                             ra_timer_update, rai, rai);
 546                         ra_timer_update((void *)rai, &rai->timer->tm);
 547                         rtadvd_set_timer(&rai->timer->tm, rai->timer);
 548                 }
 549         }
 550
 551         return;
 552 }
 553
 554 void
 555 rtadvd_input()
 556 {
 557         int i;
 558         int *hlimp = NULL;
 559 #ifdef OLDRAWSOCKET
 560         struct ip6_hdr *ip;
 561 #endif
 562         struct icmp6_hdr *icp;
 563         int ifindex = 0;
 564         struct cmsghdr *cm;
 565         struct in6_pktinfo *pi = NULL;
 566         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 567         struct in6_addr dst = in6addr_any;
 568
 569         /*
 570          * Get message. We reset msg_controllen since the field could
 571          * be modified if we had received a message before setting
 572          * receive options.
 573          */
 574         rcvmhdr.msg_controllen = rcvcmsgbuflen;
 575         if ((i = recvmsg(sock, &rcvmhdr, 0)) < 0)
 576                 return;
 577
 578         /* extract optional information via Advanced API */
 579         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 580              cm;
 581              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 582                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 583                     cm->cmsg_type == IPV6_PKTINFO &&
 584                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 585                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 586                         ifindex = pi->ipi6_ifindex;
 587                         dst = pi->ipi6_addr;
 588                 }
 589                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 590                     cm->cmsg_type == IPV6_HOPLIMIT &&
 591                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 592                         hlimp = (int *)CMSG_DATA(cm);
 593         }
 594         if (ifindex == 0) {
 595                 syslog(LOG_ERR,
 596                        "<%s> failed to get receiving interface",
 597                        __FUNCTION__);
 598                 return;
 599         }
 600         if (hlimp == NULL) {
 601                 syslog(LOG_ERR,
 602                        "<%s> failed to get receiving hop limit",
 603                        __FUNCTION__);
 604                 return;
 605         }
 606
 607         /*
 608          * If we happen to receive data on an interface which is now down,
 609          * just discard the data.
 610          */
 611         if ((iflist[pi->ipi6_ifindex]->ifm_flags & IFF_UP) == 0) {
 612                 syslog(LOG_INFO,
 613                        "<%s> received data on a disabled interface (%s)",
 614                        __FUNCTION__,
 615                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 616                 return;
 617         }
 618
 619 #ifdef OLDRAWSOCKET
 620         if (i < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) {
 621                 syslog(LOG_ERR,
 622                        "<%s> packet size(%d) is too short",
 623                        __FUNCTION__, i);
 624                 return;
 625         }
 626
 627         ip = (struct ip6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 628         icp = (struct icmp6_hdr *)(ip + 1); /* XXX: ext. hdr? */
 629 #else
 630         if (i < sizeof(struct icmp6_hdr)) {
 631                 syslog(LOG_ERR,
 632                        "<%s> packet size(%d) is too short",
 633                        __FUNCTION__, i);
 634                 return;
 635         }
 636
 637         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 638 #endif
 639
 640         switch (icp->icmp6_type) {
 641         case ND_ROUTER_SOLICIT:
 642                 /*
 643                  * Message verification - RFC-2461 6.1.1
 644                  * XXX: these checks must be done in the kernel as well,
 645                  *      but we can't completely rely on them.
 646                  */
 647                 if (*hlimp != 255) {
 648                         syslog(LOG_NOTICE,
 649                             "<%s> RS with invalid hop limit(%d) "
 650                             "received from %s on %s",
 651                             __FUNCTION__, *hlimp,
 652                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 653                             INET6_ADDRSTRLEN),
 654                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 655                         return;
 656                 }
 657                 if (icp->icmp6_code) {
 658                         syslog(LOG_NOTICE,
 659                             "<%s> RS with invalid ICMP6 code(%d) "
 660                             "received from %s on %s",
 661                             __FUNCTION__, icp->icmp6_code,
 662                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 663                             INET6_ADDRSTRLEN),
 664                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 665                         return;
 666                 }
 667                 if (i < sizeof(struct nd_router_solicit)) {
 668                         syslog(LOG_NOTICE,
 669                             "<%s> RS from %s on %s does not have enough "
 670                             "length (len = %d)",
 671                             __FUNCTION__,
 672                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 673                             INET6_ADDRSTRLEN),
 674                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 675                         return;
 676                 }
 677                 rs_input(i, (struct nd_router_solicit *)icp, pi, &from);
 678                 break;
 679         case ND_ROUTER_ADVERT:
 680                 /*
 681                  * Message verification - RFC-2461 6.1.2
 682                  * XXX: there's a same dilemma as above...
 683                  */
 684                 if (*hlimp != 255) {
 685                         syslog(LOG_NOTICE,
 686                             "<%s> RA with invalid hop limit(%d) "
 687                             "received from %s on %s",
 688                             __FUNCTION__, *hlimp,
 689                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 690                             INET6_ADDRSTRLEN),
 691                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 692                         return;
 693                 }
 694                 if (icp->icmp6_code) {
 695                         syslog(LOG_NOTICE,
 696                             "<%s> RA with invalid ICMP6 code(%d) "
 697                             "received from %s on %s",
 698                             __FUNCTION__, icp->icmp6_code,
 699                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 700                             INET6_ADDRSTRLEN),
 701                             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 702                         return;
 703                 }
 704                 if (i < sizeof(struct nd_router_advert)) {
 705                         syslog(LOG_NOTICE,
 706                             "<%s> RA from %s on %s does not have enough "
 707                             "length (len = %d)",
 708                             __FUNCTION__,
 709                             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 710                             INET6_ADDRSTRLEN),
 711                             if_indextoname(pi->ipi6_ifindex, ifnamebuf), i);
 712                         return;
 713                 }
 714                 ra_input(i, (struct nd_router_advert *)icp, pi, &from);
 715                 break;
 716         case ICMP6_ROUTER_RENUMBERING:
 717                 if (accept_rr == 0) {
 718                         syslog(LOG_ERR, "<%s> received a router renumbering "
 719                             "message, but not allowed to be accepted",
 720                             __FUNCTION__);
 721                         break;
 722                 }
 723                 rr_input(i, (struct icmp6_router_renum *)icp, pi, &from,
 724                          &dst);
 725                 break;
 726         default:
 727                 /*
 728                  * Note that this case is POSSIBLE, especially just
 729                  * after invocation of the daemon. This is because we
 730                  * could receive message after opening the socket and
 731                  * before setting ICMP6 type filter(see sock_open()).
 732                  */
 733                 syslog(LOG_ERR, "<%s> invalid icmp type(%d)",
 734                     __FUNCTION__, icp->icmp6_type);
 735                 return;
 736         }
 737
 738         return;
 739 }
 740
 741 static void
 742 rs_input(int len, struct nd_router_solicit *rs,
 743          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 744 {
 745         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 746         union nd_opts ndopts;
 747         struct rainfo *ra;
 748
 749         syslog(LOG_DEBUG,
 750                "<%s> RS received from %s on %s",
 751                __FUNCTION__,
 752                inet_ntop(AF_INET6, &from->sin6_addr,
 753                          ntopbuf, INET6_ADDRSTRLEN),
 754                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 755
 756         /* ND option check */
 757         memset(&ndopts, 0, sizeof(ndopts));
 758         if (nd6_options((struct nd_opt_hdr *)(rs + 1),
 759                         len - sizeof(struct nd_router_solicit),
 760                          &ndopts, NDOPT_FLAG_SRCLINKADDR)) {
 761                 syslog(LOG_DEBUG,
 762                        "<%s> ND option check failed for an RS from %s on %s",
 763                        __FUNCTION__,
 764                        inet_ntop(AF_INET6, &from->sin6_addr,
 765                                  ntopbuf, INET6_ADDRSTRLEN),
 766                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 767                 return;
 768         }
 769
 770         /*
 771          * If the IP source address is the unspecified address, there
 772          * must be no source link-layer address option in the message.
 773          * (RFC-2461 6.1.1)
 774          */
 775         if (IN6_IS_ADDR_UNSPECIFIED(&from->sin6_addr) &&
 776             ndopts.nd_opts_src_lladdr) {
 777                 syslog(LOG_ERR,
 778                        "<%s> RS from unspecified src on %s has a link-layer"
 779                        " address option",
 780                        __FUNCTION__,
 781                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 782                 goto done;
 783         }
 784
 785         ra = ralist;
 786         while (ra != NULL) {
 787                 if (pi->ipi6_ifindex == ra->ifindex)
 788                         break;
 789                 ra = ra->next;
 790         }
 791         if (ra == NULL) {
 792                 syslog(LOG_INFO,
 793                        "<%s> RS received on non advertising interface(%s)",
 794                        __FUNCTION__,
 795                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 796                 goto done;
 797         }
 798
 799         ra->rsinput++;          /* increment statistics */
 800
 801         /*
 802          * Decide whether to send RA according to the rate-limit
 803          * consideration.
 804          */
 805         {
 806                 long delay;     /* must not be greater than 1000000 */
 807                 struct timeval interval, now, min_delay, tm_tmp, *rest;
 808                 struct soliciter *sol;
 809
 810                 /*
 811                  * record sockaddr waiting for RA, if possible
 812                  */
 813                 sol = (struct soliciter *)malloc(sizeof(*sol));
 814                 if (sol) {
 815                         sol->addr = *from;
 816                         /*XXX RFC2553 need clarification on flowinfo */
 817                         sol->addr.sin6_flowinfo = 0;
 818                         sol->next = ra->soliciter;
 819                         ra->soliciter = sol->next;
 820                 }
 821
 822                 /*
 823                  * If there is already a waiting RS packet, don't
 824                  * update the timer.
 825                  */
 826                 if (ra->waiting++)
 827                         goto done;
 828
 829                 /*
 830                  * Compute a random delay. If the computed value
 831                  * corresponds to a time later than the time the next
 832                  * multicast RA is scheduled to be sent, ignore the random
 833                  * delay and send the advertisement at the
 834                  * already-scheduled time. RFC-2461 6.2.6
 835                  */
 836                 delay = random() % MAX_RA_DELAY_TIME;
 837                 interval.tv_sec = 0;
 838                 interval.tv_usec = delay;
 839                 rest = rtadvd_timer_rest(ra->timer);
 840                 if (TIMEVAL_LT(*rest, interval)) {
 841                         syslog(LOG_DEBUG,
 842                                "<%s> random delay is larger than "
 843                                "the rest of normal timer",
 844                                __FUNCTION__);
 845                         interval = *rest;
 846                 }
 847
 848                 /*
 849                  * If we sent a multicast Router Advertisement within
 850                  * the last MIN_DELAY_BETWEEN_RAS seconds, schedule
 851                  * the advertisement to be sent at a time corresponding to
 852                  * MIN_DELAY_BETWEEN_RAS plus the random value after the
 853                  * previous advertisement was sent.
 854                  */
 855                 gettimeofday(&now, NULL);
 856                 TIMEVAL_SUB(&now, &ra->lastsent, &tm_tmp);
 857                 min_delay.tv_sec = MIN_DELAY_BETWEEN_RAS;
 858                 min_delay.tv_usec = 0;
 859                 if (TIMEVAL_LT(tm_tmp, min_delay)) {
 860                         TIMEVAL_SUB(&min_delay, &tm_tmp, &min_delay);
 861                         TIMEVAL_ADD(&min_delay, &interval, &interval);
 862                 }
 863                 rtadvd_set_timer(&interval, ra->timer);
 864                 goto done;
 865         }
 866
 867   done:
 868         free_ndopts(&ndopts);
 869         return;
 870 }
 871
 872 static void
 873 ra_input(int len, struct nd_router_advert *ra,
 874          struct in6_pktinfo *pi, struct sockaddr_in6 *from)
 875 {
 876         struct rainfo *rai;
 877         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 878         union nd_opts ndopts;
 879         char *on_off[] = {"OFF", "ON"};
 880         u_int32_t reachabletime, retranstimer, mtu;
 881         int inconsistent = 0;
 882
 883         syslog(LOG_DEBUG,
 884                "<%s> RA received from %s on %s",
 885                __FUNCTION__,
 886                inet_ntop(AF_INET6, &from->sin6_addr,
 887                          ntopbuf, INET6_ADDRSTRLEN),
 888                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 889
 890         /* ND option check */
 891         memset(&ndopts, 0, sizeof(ndopts));
 892         if (nd6_options((struct nd_opt_hdr *)(ra + 1),
 893                         len - sizeof(struct nd_router_advert),
 894                         &ndopts, NDOPT_FLAG_SRCLINKADDR |
 895                         NDOPT_FLAG_PREFIXINFO | NDOPT_FLAG_MTU)) {
 896                 syslog(LOG_ERR,
 897                        "<%s> ND option check failed for an RA from %s on %s",
 898                        __FUNCTION__,
 899                        inet_ntop(AF_INET6, &from->sin6_addr,
 900                                  ntopbuf, INET6_ADDRSTRLEN),
 901                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 902                 return;
 903         }
 904
 905         /*
 906          * RA consistency check according to RFC-2461 6.2.7
 907          */
 908         if ((rai = if_indextorainfo(pi->ipi6_ifindex)) == 0) {
 909                 syslog(LOG_INFO,
 910                        "<%s> received RA from %s on non-advertising"
 911                        " interface(%s)",
 912                        __FUNCTION__,
 913                        inet_ntop(AF_INET6, &from->sin6_addr,
 914                                  ntopbuf, INET6_ADDRSTRLEN),
 915                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 916                 goto done;
 917         }
 918         rai->rainput++;         /* increment statistics */
 919
 920         /* Cur Hop Limit value */
 921         if (ra->nd_ra_curhoplimit && rai->hoplimit &&
 922             ra->nd_ra_curhoplimit != rai->hoplimit) {
 923                 syslog(LOG_INFO,
 924                        "<%s> CurHopLimit inconsistent on %s:"
 925                        " %d from %s, %d from us",
 926                        __FUNCTION__,
 927                        rai->ifname,
 928                        ra->nd_ra_curhoplimit,
 929                        inet_ntop(AF_INET6, &from->sin6_addr,
 930                                  ntopbuf, INET6_ADDRSTRLEN),
 931                        rai->hoplimit);
 932                 inconsistent++;
 933         }
 934         /* M flag */
 935         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) !=
 936             rai->managedflg) {
 937                 syslog(LOG_INFO,
 938                        "<%s> M flag inconsistent on %s:"
 939                        " %s from %s, %s from us",
 940                        __FUNCTION__,
 941                        rai->ifname,
 942                        on_off[!rai->managedflg],
 943                        inet_ntop(AF_INET6, &from->sin6_addr,
 944                                  ntopbuf, INET6_ADDRSTRLEN),
 945                        on_off[rai->managedflg]);
 946                 inconsistent++;
 947         }
 948         /* O flag */
 949         if ((ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) !=
 950             rai->otherflg) {
 951                 syslog(LOG_INFO,
 952                        "<%s> O flag inconsistent on %s:"
 953                        " %s from %s, %s from us",
 954                        __FUNCTION__,
 955                        rai->ifname,
 956                        on_off[!rai->otherflg],
 957                        inet_ntop(AF_INET6, &from->sin6_addr,
 958                                  ntopbuf, INET6_ADDRSTRLEN),
 959                        on_off[rai->otherflg]);
 960                 inconsistent++;
 961         }
 962         /* Reachable Time */
 963         reachabletime = ntohl(ra->nd_ra_reachable);
 964         if (reachabletime && rai->reachabletime &&
 965             reachabletime != rai->reachabletime) {
 966                 syslog(LOG_INFO,
 967                        "<%s> ReachableTime inconsistent on %s:"
 968                        " %d from %s, %d from us",
 969                        __FUNCTION__,
 970                        rai->ifname,
 971                        reachabletime,
 972                        inet_ntop(AF_INET6, &from->sin6_addr,
 973                                  ntopbuf, INET6_ADDRSTRLEN),
 974                        rai->reachabletime);
 975                 inconsistent++;
 976         }
 977         /* Retrans Timer */
 978         retranstimer = ntohl(ra->nd_ra_retransmit);
 979         if (retranstimer && rai->retranstimer &&
 980             retranstimer != rai->retranstimer) {
 981                 syslog(LOG_INFO,
 982                        "<%s> RetranceTimer inconsistent on %s:"
 983                        " %d from %s, %d from us",
 984                        __FUNCTION__,
 985                        rai->ifname,
 986                        retranstimer,
 987                        inet_ntop(AF_INET6, &from->sin6_addr,
 988                                  ntopbuf, INET6_ADDRSTRLEN),
 989                        rai->retranstimer);
 990                 inconsistent++;
 991         }
 992         /* Values in the MTU options */
 993         if (ndopts.nd_opts_mtu) {
 994                 mtu = ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
 995                 if (mtu && rai->linkmtu && mtu != rai->linkmtu) {
 996                         syslog(LOG_INFO,
 997                                "<%s> MTU option value inconsistent on %s:"
 998                                " %d from %s, %d from us",
 999                                __FUNCTION__,
1000                                rai->ifname, mtu,
1001                                inet_ntop(AF_INET6, &from->sin6_addr,
1002                                          ntopbuf, INET6_ADDRSTRLEN),
1003                                rai->linkmtu);
1004                         inconsistent++;
1005                 }
1006         }
1007         /* Preferred and Valid Lifetimes for prefixes */
1008         {
1009                 struct nd_optlist *optp = ndopts.nd_opts_list;
1010
1011                 if (ndopts.nd_opts_pi) {
1012                         if (prefix_check(ndopts.nd_opts_pi, rai, from))
1013                                 inconsistent++;
1014                 }
1015                 while (optp) {
1016                         if (prefix_check((struct nd_opt_prefix_info *)optp->opt,
1017                                          rai, from))
1018                                 inconsistent++;
1019                         optp = optp->next;
1020                 }
1021         }
1022
1023         if (inconsistent)
1024                 rai->rainconsistent++;
1025
1026   done:
1027         free_ndopts(&ndopts);
1028         return;
1029 }
1030
1031 /* return a non-zero value if the received prefix is inconsitent with ours */
1032 static int
1033 prefix_check(struct nd_opt_prefix_info *pinfo,
1034              struct rainfo *rai, struct sockaddr_in6 *from)
1035 {
1036         u_int32_t preferred_time, valid_time;
1037         struct prefix *pp;
1038         int inconsistent = 0;
1039         u_char ntopbuf[INET6_ADDRSTRLEN], prefixbuf[INET6_ADDRSTRLEN];
1040         struct timeval now;
1041
1042 #if 0                           /* impossible */
1043         if (pinfo->nd_opt_pi_type != ND_OPT_PREFIX_INFORMATION)
1044                 return(0);
1045 #endif
1046
1047         /*
1048          * log if the adveritsed prefix has link-local scope(sanity check?)
1049          */
1050         if (IN6_IS_ADDR_LINKLOCAL(&pinfo->nd_opt_pi_prefix)) {
1051                 syslog(LOG_INFO,
1052                        "<%s> link-local prefix %s/%d is advertised "
1053                        "from %s on %s",
1054                        __FUNCTION__,
1055                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1056                                  prefixbuf, INET6_ADDRSTRLEN),
1057                        pinfo->nd_opt_pi_prefix_len,
1058                        inet_ntop(AF_INET6, &from->sin6_addr,
1059                                  ntopbuf, INET6_ADDRSTRLEN),
1060                        rai->ifname);
1061         }
1062
1063         if ((pp = find_prefix(rai, &pinfo->nd_opt_pi_prefix,
1064                               pinfo->nd_opt_pi_prefix_len)) == NULL) {
1065                 syslog(LOG_INFO,
1066                        "<%s> prefix %s/%d from %s on %s is not in our list",
1067                        __FUNCTION__,
1068                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1069                                  prefixbuf, INET6_ADDRSTRLEN),
1070                        pinfo->nd_opt_pi_prefix_len,
1071                        inet_ntop(AF_INET6, &from->sin6_addr,
1072                                  ntopbuf, INET6_ADDRSTRLEN),
1073                        rai->ifname);
1074                 return(0);
1075         }
1076
1077         preferred_time = ntohl(pinfo->nd_opt_pi_preferred_time);
1078         if (pp->pltimeexpire) {
1079                 /*
1080                  * The lifetime is decremented in real time, so we should
1081                  * compare the expiration time.
1082                  * (RFC 2461 Section 6.2.7.)
1083                  * XXX: can we really expect that all routers on the link
1084                  * have synchronized clocks?
1085                  */
1086                 gettimeofday(&now, NULL);
1087                 preferred_time += now.tv_sec;
1088
1089                 if (rai->clockskew &&
1090                     abs(preferred_time - pp->pltimeexpire) > rai->clockskew) {
1091                         syslog(LOG_INFO,
1092                                "<%s> prefeerred lifetime for %s/%d"
1093                                " (decr. in real time) inconsistent on %s:"
1094                                " %d from %s, %ld from us",
1095                                __FUNCTION__,
1096                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1097                                          prefixbuf, INET6_ADDRSTRLEN),
1098                                pinfo->nd_opt_pi_prefix_len,
1099                                rai->ifname, preferred_time,
1100                                inet_ntop(AF_INET6, &from->sin6_addr,
1101                                          ntopbuf, INET6_ADDRSTRLEN),
1102                                pp->pltimeexpire);
1103                         inconsistent++;
1104                 }
1105         } else if (preferred_time != pp->preflifetime) {
1106                 syslog(LOG_INFO,
1107                        "<%s> prefeerred lifetime for %s/%d"
1108                        " inconsistent on %s:"
1109                        " %d from %s, %d from us",
1110                        __FUNCTION__,
1111                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1112                                  prefixbuf, INET6_ADDRSTRLEN),
1113                        pinfo->nd_opt_pi_prefix_len,
1114                        rai->ifname, preferred_time,
1115                        inet_ntop(AF_INET6, &from->sin6_addr,
1116                                  ntopbuf, INET6_ADDRSTRLEN),
1117                        pp->preflifetime);
1118         }
1119
1120         valid_time = ntohl(pinfo->nd_opt_pi_valid_time);
1121         if (pp->vltimeexpire) {
1122                 gettimeofday(&now, NULL);
1123                 valid_time += now.tv_sec;
1124
1125                 if (rai->clockskew &&
1126                     abs(valid_time - pp->vltimeexpire) > rai->clockskew) {
1127                         syslog(LOG_INFO,
1128                                "<%s> valid lifetime for %s/%d"
1129                                " (decr. in real time) inconsistent on %s:"
1130                                " %d from %s, %ld from us",
1131                                __FUNCTION__,
1132                                inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1133                                          prefixbuf, INET6_ADDRSTRLEN),
1134                                pinfo->nd_opt_pi_prefix_len,
1135                                rai->ifname, preferred_time,
1136                                inet_ntop(AF_INET6, &from->sin6_addr,
1137                                          ntopbuf, INET6_ADDRSTRLEN),
1138                                pp->vltimeexpire);
1139                         inconsistent++;
1140                 }
1141         } else if (valid_time != pp->validlifetime) {
1142                 syslog(LOG_INFO,
1143                        "<%s> valid lifetime for %s/%d"
1144                        " inconsistent on %s:"
1145                        " %d from %s, %d from us",
1146                        __FUNCTION__,
1147                        inet_ntop(AF_INET6, &pinfo->nd_opt_pi_prefix,
1148                                  prefixbuf, INET6_ADDRSTRLEN),
1149                        pinfo->nd_opt_pi_prefix_len,
1150                        rai->ifname, valid_time,
1151                        inet_ntop(AF_INET6, &from->sin6_addr,
1152                                  ntopbuf, INET6_ADDRSTRLEN),
1153                        pp->validlifetime);
1154                 inconsistent++;
1155         }
1156
1157         return(inconsistent);
1158 }
1159
1160 struct prefix *
1161 find_prefix(struct rainfo *rai, struct in6_addr *prefix, int plen)
1162 {
1163         struct prefix *pp;
1164         int bytelen, bitlen;
1165
1166         for (pp = rai->prefix.next; pp != &rai->prefix; pp = pp->next) {
1167                 if (plen != pp->prefixlen)
1168                         continue;
1169                 bytelen = plen / 8;
1170                 bitlen = plen % 8;
1171                 if (memcmp((void *)prefix, (void *)&pp->prefix, bytelen))
1172                         continue;
1173                 if (prefix->s6_addr[bytelen] >> (8 - bitlen) ==
1174                     pp->prefix.s6_addr[bytelen] >> (8 - bitlen))
1175                         return(pp);
1176         }
1177
1178         return(NULL);
1179 }
1180
1181 /* check if p0/plen0 matches p1/plen1; return 1 if matches, otherwise 0. */
1182 int
1183 prefix_match(struct in6_addr *p0, int plen0,
1184              struct in6_addr *p1, int plen1)
1185 {
1186         int bytelen, bitlen;
1187
1188         if (plen0 < plen1)
1189                 return(0);
1190         bytelen = plen1 / 8;
1191         bitlen = plen1 % 8;
1192         if (memcmp((void *)p0, (void *)p1, bytelen))
1193                 return(0);
1194         if (p0->s6_addr[bytelen] >> (8 - bitlen) ==
1195             p1->s6_addr[bytelen] >> (8 - bitlen))
1196                 return(1);
1197
1198         return(0);
1199 }
1200
1201 static int
1202 nd6_options(struct nd_opt_hdr *hdr, int limit,
1203             union nd_opts *ndopts, u_int32_t optflags)
1204 {
1205         int optlen = 0;
1206
1207         for (; limit > 0; limit -= optlen) {
1208                 if (limit < sizeof(struct nd_opt_hdr)) {
1209                         syslog(LOG_INFO, "<%s> short option header", __FUNCTION__);
1210                         goto bad;
1211                 }
1212
1213                 hdr = (struct nd_opt_hdr *)((caddr_t)hdr + optlen);
1214                 if (hdr->nd_opt_len == 0) {
1215                         syslog(LOG_INFO,
1216                             "<%s> bad ND option length(0) (type = %d)",
1217                             __FUNCTION__, hdr->nd_opt_type);
1218                         goto bad;
1219                 }
1220                 optlen = hdr->nd_opt_len << 3;
1221                 if (optlen > limit) {
1222                         syslog(LOG_INFO, "<%s> short option", __FUNCTION__);
1223                         goto bad;
1224                 }
1225
1226                 if (hdr->nd_opt_type > ND_OPT_MTU) {
1227                         syslog(LOG_INFO,
1228                             "<%s> unknown ND option(type %d)",
1229                             __FUNCTION__, hdr->nd_opt_type);
1230                         continue;
1231                 }
1232
1233                 if ((ndopt_flags[hdr->nd_opt_type] & optflags) == 0) {
1234                         syslog(LOG_INFO,
1235                             "<%s> unexpected ND option(type %d)",
1236                                __FUNCTION__, hdr->nd_opt_type);
1237                         continue;
1238                 }
1239
1240                 /*
1241                  * Option length check.  Do it here for all fixed-length
1242                  * options.
1243                  */
1244                 if ((hdr->nd_opt_type == ND_OPT_MTU &&
1245                     (optlen != sizeof(struct nd_opt_mtu))) ||
1246                     ((hdr->nd_opt_type == ND_OPT_PREFIX_INFORMATION &&
1247                     optlen != sizeof(struct nd_opt_prefix_info)))) {
1248                         syslog(LOG_INFO, "<%s> invalid option length",
1249                             __FUNCTION__);
1250                         continue;
1251                 }
1252
1253                 switch (hdr->nd_opt_type) {
1254                 case ND_OPT_SOURCE_LINKADDR:
1255                 case ND_OPT_TARGET_LINKADDR:
1256                 case ND_OPT_REDIRECTED_HEADER:
1257                         break;  /* we don't care about these options */
1258                 case ND_OPT_MTU:
1259                         if (ndopts->nd_opt_array[hdr->nd_opt_type]) {
1260                                 syslog(LOG_INFO,
1261                                     "<%s> duplicated ND option (type = %d)",
1262                                     __FUNCTION__, hdr->nd_opt_type);
1263                         }
1264                         ndopts->nd_opt_array[hdr->nd_opt_type] = hdr;
1265                         break;
1266                 case ND_OPT_PREFIX_INFORMATION:
1267                 {
1268                         struct nd_optlist *pfxlist;
1269
1270                         if (ndopts->nd_opts_pi == 0) {
1271                                 ndopts->nd_opts_pi =
1272                                     (struct nd_opt_prefix_info *)hdr;
1273                                 continue;
1274                         }
1275                         if ((pfxlist = malloc(sizeof(*pfxlist))) == NULL) {
1276                                 syslog(LOG_ERR, "<%s> can't allocate memory",
1277                                     __FUNCTION__);
1278                                 goto bad;
1279                         }
1280                         pfxlist->next = ndopts->nd_opts_list;
1281                         pfxlist->opt = hdr;
1282                         ndopts->nd_opts_list = pfxlist;
1283
1284                         break;
1285                 }
1286                 default:        /* impossible */
1287                         break;
1288                 }
1289         }
1290
1291         return(0);
1292
1293   bad:
1294         free_ndopts(ndopts);
1295
1296         return(-1);
1297 }
1298
1299 static void
1300 free_ndopts(union nd_opts *ndopts)
1301 {
1302         struct nd_optlist *opt = ndopts->nd_opts_list, *next;
1303
1304         while (opt) {
1305                 next = opt->next;
1306                 free(opt);
1307                 opt = next;
1308         }
1309 }
1310
1311 void
1312 sock_open()
1313 {
1314         struct icmp6_filter filt;
1315         struct ipv6_mreq mreq;
1316         struct rainfo *ra = ralist;
1317         int on;
1318         /* XXX: should be max MTU attached to the node */
1319         static u_char answer[1500];
1320
1321         rcvcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1322                                 CMSG_SPACE(sizeof(int));
1323         rcvcmsgbuf = (u_char *)malloc(rcvcmsgbuflen);
1324         if (rcvcmsgbuf == NULL) {
1325                 syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1326                 exit(1);
1327         }
1328
1329         sndcmsgbuflen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
1330                                 CMSG_SPACE(sizeof(int));
1331         sndcmsgbuf = (u_char *)malloc(sndcmsgbuflen);
1332         if (sndcmsgbuf == NULL) {
1333                 syslog(LOG_ERR, "<%s> not enough core", __FUNCTION__);
1334                 exit(1);
1335         }
1336
1337         if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
1338                 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
1339                        strerror(errno));
1340                 exit(1);
1341         }
1342
1343         /* specify to tell receiving interface */
1344         on = 1;
1345 #ifdef IPV6_RECVPKTINFO
1346         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
1347                        sizeof(on)) < 0) {
1348                 syslog(LOG_ERR, "<%s> IPV6_RECVPKTINFO: %s",
1349                        __FUNCTION__, strerror(errno));
1350                 exit(1);
1351         }
1352 #else  /* old adv. API */
1353         if (setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
1354                        sizeof(on)) < 0) {
1355                 syslog(LOG_ERR, "<%s> IPV6_PKTINFO: %s",
1356                        __FUNCTION__, strerror(errno));
1357                 exit(1);
1358         }
1359 #endif
1360
1361         on = 1;
1362         /* specify to tell value of hoplimit field of received IP6 hdr */
1363 #ifdef IPV6_RECVHOPLIMIT
1364         if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
1365                        sizeof(on)) < 0) {
1366                 syslog(LOG_ERR, "<%s> IPV6_RECVHOPLIMIT: %s",
1367                        __FUNCTION__, strerror(errno));
1368                 exit(1);
1369         }
1370 #else  /* old adv. API */
1371         if (setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
1372                        sizeof(on)) < 0) {
1373                 syslog(LOG_ERR, "<%s> IPV6_HOPLIMIT: %s",
1374                        __FUNCTION__, strerror(errno));
1375                 exit(1);
1376         }
1377 #endif
1378
1379         ICMP6_FILTER_SETBLOCKALL(&filt);
1380         ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
1381         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
1382         if (accept_rr)
1383                 ICMP6_FILTER_SETPASS(ICMP6_ROUTER_RENUMBERING, &filt);
1384         if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
1385                        sizeof(filt)) < 0) {
1386                 syslog(LOG_ERR, "<%s> IICMP6_FILTER: %s",
1387                        __FUNCTION__, strerror(errno));
1388                 exit(1);
1389         }
1390
1391         /*
1392          * join all routers multicast address on each advertising interface.
1393          */
1394         if (inet_pton(AF_INET6, ALLROUTERS_LINK,
1395                       &mreq.ipv6mr_multiaddr.s6_addr)
1396             != 1) {
1397                 syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1398                        __FUNCTION__);
1399                 exit(1);
1400         }
1401         while (ra) {
1402                 mreq.ipv6mr_interface = ra->ifindex;
1403                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq,
1404                                sizeof(mreq)) < 0) {
1405                         syslog(LOG_ERR, "<%s> IPV6_JOIN_GROUP(link) on %s: %s",
1406                                __FUNCTION__, ra->ifname, strerror(errno));
1407                         exit(1);
1408                 }
1409                 ra = ra->next;
1410         }
1411
1412         /*
1413          * When attending router renumbering, join all-routers site-local
1414          * multicast group.
1415          */
1416         if (accept_rr) {
1417                 if (inet_pton(AF_INET6, ALLROUTERS_SITE,
1418                               &in6a_site_allrouters) != 1) {
1419                         syslog(LOG_ERR, "<%s> inet_pton failed(library bug?)",
1420                                __FUNCTION__);
1421                         exit(1);
1422                 }
1423                 mreq.ipv6mr_multiaddr = in6a_site_allrouters;
1424                 if (mcastif) {
1425                         if ((mreq.ipv6mr_interface = if_nametoindex(mcastif))
1426                             == 0) {
1427                                 syslog(LOG_ERR,
1428                                        "<%s> invalid interface: %s",
1429                                        __FUNCTION__, mcastif);
1430                                 exit(1);
1431                         }
1432                 } else
1433                         mreq.ipv6mr_interface = ralist->ifindex;
1434                 if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP,
1435                                &mreq, sizeof(mreq)) < 0) {
1436                         syslog(LOG_ERR,
1437                                "<%s> IPV6_JOIN_GROUP(site) on %s: %s",
1438                                __FUNCTION__,
1439                                mcastif ? mcastif : ralist->ifname,
1440                                strerror(errno));
1441                         exit(1);
1442                 }
1443         }
1444
1445         /* initialize msghdr for receiving packets */
1446         rcviov[0].iov_base = (caddr_t)answer;
1447         rcviov[0].iov_len = sizeof(answer);
1448         rcvmhdr.msg_name = (caddr_t)&from;
1449         rcvmhdr.msg_namelen = sizeof(from);
1450         rcvmhdr.msg_iov = rcviov;
1451         rcvmhdr.msg_iovlen = 1;
1452         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
1453         rcvmhdr.msg_controllen = rcvcmsgbuflen;
1454
1455         /* initialize msghdr for sending packets */
1456         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
1457         sndmhdr.msg_iov = sndiov;
1458         sndmhdr.msg_iovlen = 1;
1459         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
1460         sndmhdr.msg_controllen = sndcmsgbuflen;
1461
1462         return;
1463 }
1464
1465 /* open a routing socket to watch the routing table */
1466 static void
1467 rtsock_open()
1468 {
1469         if ((rtsock = socket(PF_ROUTE, SOCK_RAW, 0)) < 0) {
1470                 syslog(LOG_ERR,
1471                        "<%s> socket: %s", __FUNCTION__, strerror(errno));
1472                 exit(1);
1473         }
1474 }
1475
1476 struct rainfo *
1477 if_indextorainfo(int index)
1478 {
1479         struct rainfo *rai = ralist;
1480
1481         for (rai = ralist; rai; rai = rai->next) {
1482                 if (rai->ifindex == index)
1483                         return(rai);
1484         }
1485
1486         return(NULL);           /* search failed */
1487 }
1488
1489 static void
1490 ra_output(rainfo)
1491 struct rainfo *rainfo;
1492 {
1493         int i;
1494         struct cmsghdr *cm;
1495         struct in6_pktinfo *pi;
1496         struct soliciter *sol, *nextsol;
1497
1498         if ((iflist[rainfo->ifindex]->ifm_flags & IFF_UP) == 0) {
1499                 syslog(LOG_DEBUG, "<%s> %s is not up, skip sending RA",
1500                        __FUNCTION__, rainfo->ifname);
1501                 return;
1502         }
1503
1504         make_packet(rainfo);    /* XXX: inefficient */
1505
1506         sndmhdr.msg_name = (caddr_t)&sin6_allnodes;
1507         sndmhdr.msg_iov[0].iov_base = (caddr_t)rainfo->ra_data;
1508         sndmhdr.msg_iov[0].iov_len = rainfo->ra_datalen;
1509
1510         cm = CMSG_FIRSTHDR(&sndmhdr);
1511         /* specify the outgoing interface */
1512         cm->cmsg_level = IPPROTO_IPV6;
1513         cm->cmsg_type = IPV6_PKTINFO;
1514         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1515         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
1516         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
1517         pi->ipi6_ifindex = rainfo->ifindex;
1518
1519         /* specify the hop limit of the packet */
1520         {
1521                 int hoplimit = 255;
1522
1523                 cm = CMSG_NXTHDR(&sndmhdr, cm);
1524                 cm->cmsg_level = IPPROTO_IPV6;
1525                 cm->cmsg_type = IPV6_HOPLIMIT;
1526                 cm->cmsg_len = CMSG_LEN(sizeof(int));
1527                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
1528         }
1529
1530         syslog(LOG_DEBUG,
1531                "<%s> send RA on %s, # of waitings = %d",
1532                __FUNCTION__, rainfo->ifname, rainfo->waiting);
1533
1534         i = sendmsg(sock, &sndmhdr, 0);
1535
1536         if (i < 0 || i != rainfo->ra_datalen)  {
1537                 if (i < 0) {
1538                         syslog(LOG_ERR, "<%s> sendmsg on %s: %s",
1539                                __FUNCTION__, rainfo->ifname,
1540                                strerror(errno));
1541                 }
1542         }
1543
1544         /*
1545          * unicast advertisements
1546          * XXX commented out.  reason: though spec does not forbit it, unicast
1547          * advert does not really help
1548          */
1549         for (sol = rainfo->soliciter; sol; sol = nextsol) {
1550                 nextsol = sol->next;
1551
1552 #if 0
1553                 sndmhdr.msg_name = (caddr_t)&sol->addr;
1554                 i = sendmsg(sock, &sndmhdr, 0);
1555                 if (i < 0 || i != rainfo->ra_datalen)  {
1556                         if (i < 0) {
1557                                 syslog(LOG_ERR,
1558                                     "<%s> unicast sendmsg on %s: %s",
1559                                     __FUNCTION__, rainfo->ifname,
1560                                     strerror(errno));
1561                         }
1562                 }
1563 #endif
1564
1565                 sol->next = NULL;
1566                 free(sol);
1567         }
1568         rainfo->soliciter = NULL;
1569
1570         /* update counter */
1571         if (rainfo->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS)
1572                 rainfo->initcounter++;
1573         rainfo->raoutput++;
1574
1575         /* update timestamp */
1576         gettimeofday(&rainfo->lastsent, NULL);
1577
1578         /* reset waiting conter */
1579         rainfo->waiting = 0;
1580 }
1581
1582 /* process RA timer */
1583 struct rtadvd_timer *
1584 ra_timeout(void *data)
1585 {
1586         struct rainfo *rai = (struct rainfo *)data;
1587
1588 #ifdef notyet
1589         /* if necessary, reconstruct the packet. */
1590 #endif
1591
1592         syslog(LOG_DEBUG,
1593                "<%s> RA timer on %s is expired",
1594                __FUNCTION__, rai->ifname);
1595
1596         ra_output(rai);
1597
1598         return(rai->timer);
1599 }
1600
1601 /* update RA timer */
1602 void
1603 ra_timer_update(void *data, struct timeval *tm)
1604 {
1605         struct rainfo *rai = (struct rainfo *)data;
1606         long interval;
1607
1608         /*
1609          * Whenever a multicast advertisement is sent from an interface,
1610          * the timer is reset to a uniformly-distributed random value
1611          * between the interface's configured MinRtrAdvInterval and
1612          * MaxRtrAdvInterval (RFC2461 6.2.4).
1613          */
1614         interval = rai->mininterval;
1615         interval += random() % (rai->maxinterval - rai->mininterval);
1616
1617         /*
1618          * For the first few advertisements (up to
1619          * MAX_INITIAL_RTR_ADVERTISEMENTS), if the randomly chosen interval
1620          * is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the timer
1621          * SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL instead.
1622          * (RFC-2461 6.2.4)
1623          */
1624         if (rai->initcounter < MAX_INITIAL_RTR_ADVERTISEMENTS &&
1625             interval > MAX_INITIAL_RTR_ADVERT_INTERVAL)
1626                 interval = MAX_INITIAL_RTR_ADVERT_INTERVAL;
1627
1628         tm->tv_sec = interval;
1629         tm->tv_usec = 0;
1630
1631         syslog(LOG_DEBUG,
1632                "<%s> RA timer on %s is set to %ld:%ld",
1633                __FUNCTION__, rai->ifname,
1634                (long int)tm->tv_sec, (long int)tm->tv_usec);
1635
1636         return;
1637 }