usr.sbin/rtadvd/rrenum.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $ */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32 #include <sys/types.h>
  33 #include <sys/param.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/socket.h>
  36 #include <sys/sysctl.h>
  37
  38 #include <net/if.h>
  39 #include <net/if_dl.h>
  40 #include <net/if_var.h>
  41 #include <net/route.h>
  42 #include <netinet/in.h>
  43 #include <netinet/in_var.h>
  44 #include <netinet/icmp6.h>
  45
  46 #include <arpa/inet.h>
  47
  48 #include <errno.h>
  49 #include <netdb.h>
  50 #include <string.h>
  51 #include <stdlib.h>
  52 #include <syslog.h>
  53 #include "rtadvd.h"
  54 #include "rrenum.h"
  55 #include "if.h"
  56
  57 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  58         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  59 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  60         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  61
  62 struct rr_operation {
  63         u_long  rro_seqnum;
  64         u_long  rro_segnum_bits[8];
  65 };
  66
  67 static struct rr_operation rro;
  68 static int rr_rcvifindex;
  69 static int rrcmd2pco[RPM_PCO_MAX] = {
  70         0,
  71         SIOCAIFPREFIX_IN6,
  72         SIOCCIFPREFIX_IN6,
  73         SIOCSGIFPREFIX_IN6
  74 };
  75 static int s = -1;
  76
  77 /*
  78  * Check validity of a Prefix Control Operation(PCO).
  79  * return 0 on success, 1 on failure.
  80  */
  81 static int
  82 rr_pco_check(int len, struct rr_pco_match *rpm)
  83 {
  84         struct rr_pco_use *rpu, *rpulim;
  85         int checklen;
  86
  87         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  88         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  89             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  90                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  91                     __func__, rpm->rpm_len);
  92                 return (1);
  93         }
  94         /* rpm->rpm_code must be valid value */
  95         switch (rpm->rpm_code) {
  96         case RPM_PCO_ADD:
  97         case RPM_PCO_CHANGE:
  98         case RPM_PCO_SETGLOBAL:
  99                 break;
 100         default:
 101                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
 102                     rpm->rpm_code);
 103                 return (1);
 104         }
 105         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 106         if (rpm->rpm_matchlen > 128) {
 107                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 108                     __func__, rpm->rpm_matchlen);
 109                 return (1);
 110         }
 111
 112         /*
 113          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 114          * between 0 and 128 inclusive
 115          */
 116         for (rpu = (struct rr_pco_use *)(rpm + 1),
 117              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 118              rpu < rpulim;
 119              rpu += 1) {
 120                 checklen = rpu->rpu_uselen;
 121                 checklen += rpu->rpu_keeplen;
 122                 /*
 123                  * omit these check, because either of rpu_uselen
 124                  * and rpu_keeplen is unsigned char
 125                  *  (128 > rpu_uselen > 0)
 126                  *  (128 > rpu_keeplen > 0)
 127                  *  (rpu_uselen + rpu_keeplen > 0)
 128                  */
 129                 if (checklen > 128) {
 130                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 131                             " rpu_keeplen %d is %d(over 128)",
 132                             __func__, rpu->rpu_uselen, rpu->rpu_keeplen,
 133                             rpu->rpu_uselen + rpu->rpu_keeplen);
 134                         return (1);
 135                 }
 136         }
 137         return (0);
 138 }
 139
 140 static void
 141 do_use_prefix(int len, struct rr_pco_match *rpm,
 142         struct in6_rrenumreq *irr, int ifindex)
 143 {
 144         struct rr_pco_use *rpu, *rpulim;
 145         struct rainfo *rai;
 146         struct ifinfo *ifi;
 147         struct prefix *pfx;
 148
 149         rpu = (struct rr_pco_use *)(rpm + 1);
 150         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 151
 152         if (rpu == rpulim) {    /* no use prefix */
 153                 if (rpm->rpm_code == RPM_PCO_ADD)
 154                         return;
 155
 156                 irr->irr_u_uselen = 0;
 157                 irr->irr_u_keeplen = 0;
 158                 irr->irr_raf_mask_onlink = 0;
 159                 irr->irr_raf_mask_auto = 0;
 160                 irr->irr_vltime = 0;
 161                 irr->irr_pltime = 0;
 162                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 163                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 164                 irr->irr_useprefix.sin6_family = 0;
 165                 irr->irr_useprefix.sin6_addr = in6addr_any;
 166                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 167                     errno != EADDRNOTAVAIL)
 168                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 169                             strerror(errno));
 170                 return;
 171         }
 172
 173         for (rpu = (struct rr_pco_use *)(rpm + 1),
 174              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 175              rpu < rpulim;
 176              rpu += 1) {
 177                 /* init in6_rrenumreq fields */
 178                 irr->irr_u_uselen = rpu->rpu_uselen;
 179                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 180                 irr->irr_raf_mask_onlink =
 181                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 182                 irr->irr_raf_mask_auto =
 183                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 184                 irr->irr_vltime = ntohl(rpu->rpu_vltime);
 185                 irr->irr_pltime = ntohl(rpu->rpu_pltime);
 186                 irr->irr_raf_onlink =
 187                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ?
 188                     0 : 1;
 189                 irr->irr_raf_auto =
 190                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
 191                     0 : 1;
 192                 irr->irr_rrf_decrvalid =
 193                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
 194                     0 : 1;
 195                 irr->irr_rrf_decrprefd =
 196                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
 197                     0 : 1;
 198                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 199                 irr->irr_useprefix.sin6_family = AF_INET6;
 200                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 201
 202                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 203                     errno != EADDRNOTAVAIL)
 204                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 205                             strerror(errno));
 206
 207                 /* very adhoc: should be rewritten */
 208                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 209                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 210                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 211                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 212                         ifi = if_indextoifinfo(ifindex);
 213                         if (ifi == NULL || ifi->ifi_rainfo == NULL)
 214                                 continue; /* non-advertising IF */
 215                         rai = ifi->ifi_rainfo;
 216
 217                         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
 218                                 struct timeval now;
 219
 220                                 if (prefix_match(&pfx->pfx_prefix,
 221                                     pfx->pfx_prefixlen, &rpm->rpm_prefix,
 222                                     rpm->rpm_matchlen)) {
 223                                         /* change parameters */
 224                                         pfx->pfx_validlifetime =
 225                                             ntohl(rpu->rpu_vltime);
 226                                         pfx->pfx_preflifetime =
 227                                             ntohl(rpu->rpu_pltime);
 228                                         if (irr->irr_rrf_decrvalid) {
 229                                                 gettimeofday(&now, 0);
 230                                                 pfx->pfx_vltimeexpire =
 231                                                     now.tv_sec +
 232                                                     pfx->pfx_validlifetime;
 233                                         } else
 234                                                 pfx->pfx_vltimeexpire = 0;
 235                                         if (irr->irr_rrf_decrprefd) {
 236                                                 gettimeofday(&now, 0);
 237                                                 pfx->pfx_pltimeexpire =
 238                                                     now.tv_sec +
 239                                                     pfx->pfx_preflifetime;
 240                                         } else
 241                                                 pfx->pfx_pltimeexpire = 0;
 242                                 }
 243                         }
 244                 }
 245         }
 246 }
 247
 248 /*
 249  * process a Prefix Control Operation(PCO).
 250  * return 0 on success, 1 on failure
 251  */
 252 static int
 253 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 254 {
 255         int ifindex = 0;
 256         struct in6_rrenumreq irr;
 257         struct ifinfo *ifi;
 258
 259         if ((rr_pco_check(len, rpm) != 0))
 260                 return (1);
 261
 262         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 263                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 264                     strerror(errno));
 265                 exit(1);
 266         }
 267
 268         memset(&irr, 0, sizeof(irr));
 269         irr.irr_origin = PR_ORIG_RR;
 270         irr.irr_m_len = rpm->rpm_matchlen;
 271         irr.irr_m_minlen = rpm->rpm_minlen;
 272         irr.irr_m_maxlen = rpm->rpm_maxlen;
 273         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 274         irr.irr_matchprefix.sin6_family = AF_INET6;
 275         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 276
 277         while (if_indextoname(++ifindex, irr.irr_name)) {
 278                 ifi = if_indextoifinfo(ifindex);
 279                 if (ifi == NULL) {
 280                         syslog(LOG_ERR, "<%s> ifindex not found.",
 281                             __func__);
 282                         return (1);
 283                 }
 284                 /*
 285                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
 286                  * IFF_UP is off, the interface is not applied
 287                  */
 288                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 289                     (ifi->ifi_flags & IFF_UP) == 0)
 290                         continue;
 291                 /* TODO: interface scope check */
 292                 do_use_prefix(len, rpm, &irr, ifindex);
 293         }
 294         if (errno == ENXIO)
 295                 return (0);
 296         else if (errno) {
 297                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 298                     strerror(errno));
 299                 return (1);
 300         }
 301         return (0);
 302 }
 303
 304 /*
 305  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 306  * Router Renumbering Command packet.
 307  * return 0 on success, 1 on failure
 308  */
 309 static int
 310 do_rr(int len, struct icmp6_router_renum *rr)
 311 {
 312         struct rr_pco_match *rpm;
 313         char *cp, *lim;
 314
 315         lim = (char *)rr + len;
 316         cp = (char *)(rr + 1);
 317         len -= sizeof(struct icmp6_router_renum);
 318
 319         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 320
 321         while (cp < lim) {
 322                 int rpmlen;
 323
 324                 rpm = (struct rr_pco_match *)cp;
 325                 if ((size_t)len < sizeof(struct rr_pco_match)) {
 326                     tooshort:
 327                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 328                             "gabage at end of pkt?", __func__, len);
 329                         return (1);
 330                 }
 331                 rpmlen = rpm->rpm_len << 3;
 332                 if (len < rpmlen)
 333                         goto tooshort;
 334
 335                 if (do_pco(rr, rpmlen, rpm)) {
 336                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 337                         goto next;
 338                 }
 339
 340             next:
 341                 cp += rpmlen;
 342                 len -= rpmlen;
 343         }
 344
 345         return (0);
 346 }
 347
 348 /*
 349  * check validity of a router renumbering command packet
 350  * return 0 on success, 1 on failure
 351  */
 352 static int
 353 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 354         struct in6_addr *dst)
 355 {
 356         u_char ntopbuf[INET6_ADDRSTRLEN];
 357
 358         /* omit rr minimal length check. hope kernel have done it. */
 359         /* rr_command length check */
 360         if ((size_t)len < (sizeof(struct icmp6_router_renum) +
 361             sizeof(struct rr_pco_match))) {
 362                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 363                     __func__, len);
 364                 return (1);
 365         }
 366
 367         /* destination check. only for multicast. omit unicast check. */
 368         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 369             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 370                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 371                     __func__,
 372                     inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
 373                 return (1);
 374         }
 375
 376         /* seqnum and segnum check */
 377         if (rro.rro_seqnum > rr->rr_seqnum) {
 378                 syslog(LOG_WARNING,
 379                     "<%s> rcvd old seqnum %d from %s",
 380                     __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 381                    inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
 382                 return (1);
 383         }
 384         if (rro.rro_seqnum == rr->rr_seqnum &&
 385             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 386             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 387                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 388                         syslog(LOG_WARNING,
 389                             "<%s> rcvd duped segnum %d from %s",
 390                             __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
 391                                 ntopbuf, sizeof(ntopbuf)));
 392                 return (0);
 393         }
 394
 395         /* update seqnum */
 396         if (rro.rro_seqnum != rr->rr_seqnum) {
 397                 /* then must be "<" */
 398
 399                 /* init rro_segnum_bits */
 400                 memset(rro.rro_segnum_bits, 0,
 401                     sizeof(rro.rro_segnum_bits));
 402         }
 403         rro.rro_seqnum = rr->rr_seqnum;
 404
 405         return (0);
 406 }
 407
 408 static void
 409 rr_command_input(int len, struct icmp6_router_renum *rr,
 410         struct in6_addr *from, struct in6_addr *dst)
 411 {
 412         /* rr_command validity check */
 413         if (rr_command_check(len, rr, from, dst))
 414                 goto failed;
 415         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 416             ICMP6_RR_FLAGS_TEST)
 417                 return;
 418
 419         /* do router renumbering */
 420         if (do_rr(len, rr))
 421                 goto failed;
 422
 423         /* update segnum */
 424         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 425
 426         return;
 427
 428     failed:
 429         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 430         return;
 431 }
 432
 433 void
 434 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 435         struct sockaddr_in6 *from, struct in6_addr *dst)
 436 {
 437         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 438
 439         syslog(LOG_DEBUG,
 440             "<%s> RR received from %s to %s on %s",
 441             __func__,
 442             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
 443             inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 444             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 445
 446         /* packet validation based on Section 4.1 of RFC2894 */
 447         if ((size_t)len < sizeof(struct icmp6_router_renum)) {
 448                 syslog(LOG_NOTICE,
 449                     "<%s>: RR short message (size %d) from %s to %s on %s",
 450                     __func__, len,
 451                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
 452                         sizeof(ntopbuf[0])),
 453                     inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 454                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 455                 return;
 456         }
 457
 458         /*
 459          * If the IPv6 destination address is neither an All Routers multicast
 460          * address [AARCH] nor one of the receiving router's unicast addresses,
 461          * the message MUST be discarded and SHOULD be logged to network
 462          * management.
 463          * We rely on the kernel input routine for unicast addresses, and thus
 464          * check multicast destinations only.
 465          */
 466         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
 467             &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
 468                 syslog(LOG_NOTICE,
 469                     "<%s>: RR message with invalid destination (%s) "
 470                     "from %s on %s",
 471                     __func__,
 472                     inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
 473                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
 474                               sizeof(ntopbuf[1])),
 475                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 476                 return;
 477         }
 478
 479         rr_rcvifindex = pi->ipi6_ifindex;
 480
 481         switch (rr->rr_code) {
 482         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 483                 rr_command_input(len, rr, &from->sin6_addr, dst);
 484                 /* TODO: send reply msg */
 485                 break;
 486         case ICMP6_ROUTER_RENUMBERING_RESULT:
 487                 /* RESULT will be processed by rrenumd */
 488                 break;
 489         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 490                 /* TODO: sequence number reset */
 491                 break;
 492         default:
 493                 syslog(LOG_ERR, "<%s> received unknown code %d",
 494                     __func__, rr->rr_code);
 495                 break;
 496
 497         }
 498
 499         return;
 500 }