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  * SPDX-License-Identifier: BSD-3-Clause
   6  *
   7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the project nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 #include <sys/types.h>
  35 #include <sys/param.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/socket.h>
  38 #include <sys/sysctl.h>
  39
  40 #include <net/if.h>
  41 #include <net/if_dl.h>
  42 #include <net/route.h>
  43 #include <netinet/in.h>
  44 #include <netinet/in_var.h>
  45 #include <netinet/icmp6.h>
  46
  47 #include <arpa/inet.h>
  48
  49 #include <errno.h>
  50 #include <netdb.h>
  51 #include <string.h>
  52 #include <stdlib.h>
  53 #include <time.h>
  54 #include <syslog.h>
  55 #include "rtadvd.h"
  56 #include "rrenum.h"
  57 #include "if.h"
  58
  59 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  60         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  61 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  62         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  63
  64 struct rr_operation {
  65         u_long  rro_seqnum;
  66         u_long  rro_segnum_bits[8];
  67 };
  68
  69 static struct rr_operation rro;
  70 static int rr_rcvifindex;
  71 static int rrcmd2pco[RPM_PCO_MAX] = {
  72         0,
  73         SIOCAIFPREFIX_IN6,
  74         SIOCCIFPREFIX_IN6,
  75         SIOCSGIFPREFIX_IN6
  76 };
  77 static int s = -1;
  78
  79 /*
  80  * Check validity of a Prefix Control Operation(PCO).
  81  * return 0 on success, 1 on failure.
  82  */
  83 static int
  84 rr_pco_check(int len, struct rr_pco_match *rpm)
  85 {
  86         struct rr_pco_use *rpu, *rpulim;
  87         int checklen;
  88
  89         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  90         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  91             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  92                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  93                     __func__, rpm->rpm_len);
  94                 return (1);
  95         }
  96         /* rpm->rpm_code must be valid value */
  97         switch (rpm->rpm_code) {
  98         case RPM_PCO_ADD:
  99         case RPM_PCO_CHANGE:
 100         case RPM_PCO_SETGLOBAL:
 101                 break;
 102         default:
 103                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
 104                     rpm->rpm_code);
 105                 return (1);
 106         }
 107         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 108         if (rpm->rpm_matchlen > 128) {
 109                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 110                     __func__, rpm->rpm_matchlen);
 111                 return (1);
 112         }
 113
 114         /*
 115          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 116          * between 0 and 128 inclusive
 117          */
 118         for (rpu = (struct rr_pco_use *)(rpm + 1),
 119              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 120              rpu < rpulim;
 121              rpu += 1) {
 122                 checklen = rpu->rpu_uselen;
 123                 checklen += rpu->rpu_keeplen;
 124                 /*
 125                  * omit these check, because either of rpu_uselen
 126                  * and rpu_keeplen is unsigned char
 127                  *  (128 > rpu_uselen > 0)
 128                  *  (128 > rpu_keeplen > 0)
 129                  *  (rpu_uselen + rpu_keeplen > 0)
 130                  */
 131                 if (checklen > 128) {
 132                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 133                             " rpu_keeplen %d is %d(over 128)",
 134                             __func__, rpu->rpu_uselen, rpu->rpu_keeplen,
 135                             rpu->rpu_uselen + rpu->rpu_keeplen);
 136                         return (1);
 137                 }
 138         }
 139         return (0);
 140 }
 141
 142 static void
 143 do_use_prefix(int len, struct rr_pco_match *rpm,
 144         struct in6_rrenumreq *irr, int ifindex)
 145 {
 146         struct rr_pco_use *rpu, *rpulim;
 147         struct rainfo *rai;
 148         struct ifinfo *ifi;
 149         struct prefix *pfx;
 150
 151         rpu = (struct rr_pco_use *)(rpm + 1);
 152         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 153
 154         if (rpu == rpulim) {    /* no use prefix */
 155                 if (rpm->rpm_code == RPM_PCO_ADD)
 156                         return;
 157
 158                 irr->irr_u_uselen = 0;
 159                 irr->irr_u_keeplen = 0;
 160                 irr->irr_raf_mask_onlink = 0;
 161                 irr->irr_raf_mask_auto = 0;
 162                 irr->irr_vltime = 0;
 163                 irr->irr_pltime = 0;
 164                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 165                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 166                 irr->irr_useprefix.sin6_family = 0;
 167                 irr->irr_useprefix.sin6_addr = in6addr_any;
 168                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 169                     errno != EADDRNOTAVAIL)
 170                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 171                             strerror(errno));
 172                 return;
 173         }
 174
 175         for (rpu = (struct rr_pco_use *)(rpm + 1),
 176              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 177              rpu < rpulim;
 178              rpu += 1) {
 179                 /* init in6_rrenumreq fields */
 180                 irr->irr_u_uselen = rpu->rpu_uselen;
 181                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 182                 irr->irr_raf_mask_onlink =
 183                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 184                 irr->irr_raf_mask_auto =
 185                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 186                 irr->irr_vltime = ntohl(rpu->rpu_vltime);
 187                 irr->irr_pltime = ntohl(rpu->rpu_pltime);
 188                 irr->irr_raf_onlink =
 189                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ?
 190                     0 : 1;
 191                 irr->irr_raf_auto =
 192                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
 193                     0 : 1;
 194                 irr->irr_rrf_decrvalid =
 195                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
 196                     0 : 1;
 197                 irr->irr_rrf_decrprefd =
 198                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
 199                     0 : 1;
 200                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 201                 irr->irr_useprefix.sin6_family = AF_INET6;
 202                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 203
 204                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 205                     errno != EADDRNOTAVAIL)
 206                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 207                             strerror(errno));
 208
 209                 /* very adhoc: should be rewritten */
 210                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 211                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 212                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 213                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 214                         ifi = if_indextoifinfo(ifindex);
 215                         if (ifi == NULL || ifi->ifi_rainfo == NULL)
 216                                 continue; /* non-advertising IF */
 217                         rai = ifi->ifi_rainfo;
 218
 219                         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
 220                                 struct timespec now;
 221
 222                                 if (prefix_match(&pfx->pfx_prefix,
 223                                     pfx->pfx_prefixlen, &rpm->rpm_prefix,
 224                                     rpm->rpm_matchlen)) {
 225                                         /* change parameters */
 226                                         pfx->pfx_validlifetime =
 227                                             ntohl(rpu->rpu_vltime);
 228                                         pfx->pfx_preflifetime =
 229                                             ntohl(rpu->rpu_pltime);
 230                                         if (irr->irr_rrf_decrvalid) {
 231                                                 clock_gettime(CLOCK_MONOTONIC_FAST,
 232                                                     &now);
 233                                                 pfx->pfx_vltimeexpire =
 234                                                     now.tv_sec +
 235                                                     pfx->pfx_validlifetime;
 236                                         } else
 237                                                 pfx->pfx_vltimeexpire = 0;
 238                                         if (irr->irr_rrf_decrprefd) {
 239                                                 clock_gettime(CLOCK_MONOTONIC_FAST,
 240                                                     &now);
 241                                                 pfx->pfx_pltimeexpire =
 242                                                     now.tv_sec +
 243                                                     pfx->pfx_preflifetime;
 244                                         } else
 245                                                 pfx->pfx_pltimeexpire = 0;
 246                                 }
 247                         }
 248                 }
 249         }
 250 }
 251
 252 /*
 253  * process a Prefix Control Operation(PCO).
 254  * return 0 on success, 1 on failure
 255  */
 256 static int
 257 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 258 {
 259         int ifindex = 0;
 260         struct in6_rrenumreq irr;
 261         struct ifinfo *ifi;
 262
 263         if ((rr_pco_check(len, rpm) != 0))
 264                 return (1);
 265
 266         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 267                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 268                     strerror(errno));
 269                 exit(1);
 270         }
 271
 272         memset(&irr, 0, sizeof(irr));
 273         irr.irr_origin = PR_ORIG_RR;
 274         irr.irr_m_len = rpm->rpm_matchlen;
 275         irr.irr_m_minlen = rpm->rpm_minlen;
 276         irr.irr_m_maxlen = rpm->rpm_maxlen;
 277         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 278         irr.irr_matchprefix.sin6_family = AF_INET6;
 279         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 280
 281         while (if_indextoname(++ifindex, irr.irr_name)) {
 282                 ifi = if_indextoifinfo(ifindex);
 283                 if (ifi == NULL) {
 284                         syslog(LOG_ERR, "<%s> ifindex not found.",
 285                             __func__);
 286                         return (1);
 287                 }
 288                 /*
 289                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
 290                  * IFF_UP is off, the interface is not applied
 291                  */
 292                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 293                     (ifi->ifi_flags & IFF_UP) == 0)
 294                         continue;
 295                 /* TODO: interface scope check */
 296                 do_use_prefix(len, rpm, &irr, ifindex);
 297         }
 298         if (errno == ENXIO)
 299                 return (0);
 300         else if (errno) {
 301                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 302                     strerror(errno));
 303                 return (1);
 304         }
 305         return (0);
 306 }
 307
 308 /*
 309  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 310  * Router Renumbering Command packet.
 311  * return 0 on success, 1 on failure
 312  */
 313 static int
 314 do_rr(int len, struct icmp6_router_renum *rr)
 315 {
 316         struct rr_pco_match *rpm;
 317         char *cp, *lim;
 318
 319         lim = (char *)rr + len;
 320         cp = (char *)(rr + 1);
 321         len -= sizeof(struct icmp6_router_renum);
 322
 323         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 324
 325         while (cp < lim) {
 326                 int rpmlen;
 327
 328                 rpm = (struct rr_pco_match *)cp;
 329                 if ((size_t)len < sizeof(struct rr_pco_match)) {
 330                     tooshort:
 331                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 332                             "garbage at end of pkt?", __func__, len);
 333                         return (1);
 334                 }
 335                 rpmlen = rpm->rpm_len << 3;
 336                 if (len < rpmlen)
 337                         goto tooshort;
 338
 339                 if (do_pco(rr, rpmlen, rpm)) {
 340                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 341                         goto next;
 342                 }
 343
 344             next:
 345                 cp += rpmlen;
 346                 len -= rpmlen;
 347         }
 348
 349         return (0);
 350 }
 351
 352 /*
 353  * check validity of a router renumbering command packet
 354  * return 0 on success, 1 on failure
 355  */
 356 static int
 357 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 358         struct in6_addr *dst)
 359 {
 360         u_char ntopbuf[INET6_ADDRSTRLEN];
 361
 362         /* omit rr minimal length check. hope kernel have done it. */
 363         /* rr_command length check */
 364         if ((size_t)len < (sizeof(struct icmp6_router_renum) +
 365             sizeof(struct rr_pco_match))) {
 366                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 367                     __func__, len);
 368                 return (1);
 369         }
 370
 371         /* destination check. only for multicast. omit unicast check. */
 372         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 373             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 374                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 375                     __func__,
 376                     inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
 377                 return (1);
 378         }
 379
 380         /* seqnum and segnum check */
 381         if (rro.rro_seqnum > rr->rr_seqnum) {
 382                 syslog(LOG_WARNING,
 383                     "<%s> rcvd old seqnum %d from %s",
 384                     __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 385                    inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
 386                 return (1);
 387         }
 388         if (rro.rro_seqnum == rr->rr_seqnum &&
 389             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 390             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 391                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 392                         syslog(LOG_WARNING,
 393                             "<%s> rcvd duped segnum %d from %s",
 394                             __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
 395                                 ntopbuf, sizeof(ntopbuf)));
 396                 return (0);
 397         }
 398
 399         /* update seqnum */
 400         if (rro.rro_seqnum != rr->rr_seqnum) {
 401                 /* then must be "<" */
 402
 403                 /* init rro_segnum_bits */
 404                 memset(rro.rro_segnum_bits, 0,
 405                     sizeof(rro.rro_segnum_bits));
 406         }
 407         rro.rro_seqnum = rr->rr_seqnum;
 408
 409         return (0);
 410 }
 411
 412 static void
 413 rr_command_input(int len, struct icmp6_router_renum *rr,
 414         struct in6_addr *from, struct in6_addr *dst)
 415 {
 416         /* rr_command validity check */
 417         if (rr_command_check(len, rr, from, dst))
 418                 goto failed;
 419         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 420             ICMP6_RR_FLAGS_TEST)
 421                 return;
 422
 423         /* do router renumbering */
 424         if (do_rr(len, rr))
 425                 goto failed;
 426
 427         /* update segnum */
 428         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 429
 430         return;
 431
 432     failed:
 433         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 434         return;
 435 }
 436
 437 void
 438 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 439         struct sockaddr_in6 *from, struct in6_addr *dst)
 440 {
 441         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 442
 443         syslog(LOG_DEBUG,
 444             "<%s> RR received from %s to %s on %s",
 445             __func__,
 446             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
 447             inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 448             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 449
 450         /* packet validation based on Section 4.1 of RFC2894 */
 451         if ((size_t)len < sizeof(struct icmp6_router_renum)) {
 452                 syslog(LOG_NOTICE,
 453                     "<%s>: RR short message (size %d) from %s to %s on %s",
 454                     __func__, len,
 455                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
 456                         sizeof(ntopbuf[0])),
 457                     inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 458                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 459                 return;
 460         }
 461
 462         /*
 463          * If the IPv6 destination address is neither an All Routers multicast
 464          * address [AARCH] nor one of the receiving router's unicast addresses,
 465          * the message MUST be discarded and SHOULD be logged to network
 466          * management.
 467          * We rely on the kernel input routine for unicast addresses, and thus
 468          * check multicast destinations only.
 469          */
 470         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
 471             &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
 472                 syslog(LOG_NOTICE,
 473                     "<%s>: RR message with invalid destination (%s) "
 474                     "from %s on %s",
 475                     __func__,
 476                     inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
 477                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
 478                               sizeof(ntopbuf[1])),
 479                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 480                 return;
 481         }
 482
 483         rr_rcvifindex = pi->ipi6_ifindex;
 484
 485         switch (rr->rr_code) {
 486         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 487                 rr_command_input(len, rr, &from->sin6_addr, dst);
 488                 /* TODO: send reply msg */
 489                 break;
 490         case ICMP6_ROUTER_RENUMBERING_RESULT:
 491                 /* RESULT will be processed by rrenumd */
 492                 break;
 493         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 494                 /* TODO: sequence number reset */
 495                 break;
 496         default:
 497                 syslog(LOG_ERR, "<%s> received unknown code %d",
 498                     __func__, rr->rr_code);
 499                 break;
 500
 501         }
 502
 503         return;
 504 }