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/queue.h>
  38 #include <sys/socket.h>
  39 #include <sys/sysctl.h>
  40
  41 #include <net/if.h>
  42 #include <net/if_dl.h>
  43 #include <net/route.h>
  44 #include <netinet/in.h>
  45 #include <netinet/in_var.h>
  46 #include <netinet/icmp6.h>
  47
  48 #include <arpa/inet.h>
  49
  50 #include <errno.h>
  51 #include <netdb.h>
  52 #include <string.h>
  53 #include <stdlib.h>
  54 #include <time.h>
  55 #include <syslog.h>
  56 #include "rtadvd.h"
  57 #include "rrenum.h"
  58 #include "if.h"
  59
  60 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  61         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  62 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  63         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  64
  65 struct rr_operation {
  66         u_long  rro_seqnum;
  67         u_long  rro_segnum_bits[8];
  68 };
  69
  70 static struct rr_operation rro;
  71 static int rr_rcvifindex;
  72 static int rrcmd2pco[RPM_PCO_MAX] = {
  73         0,
  74         SIOCAIFPREFIX_IN6,
  75         SIOCCIFPREFIX_IN6,
  76         SIOCSGIFPREFIX_IN6
  77 };
  78 static int s = -1;
  79
  80 /*
  81  * Check validity of a Prefix Control Operation(PCO).
  82  * return 0 on success, 1 on failure.
  83  */
  84 static int
  85 rr_pco_check(int len, struct rr_pco_match *rpm)
  86 {
  87         struct rr_pco_use *rpu, *rpulim;
  88         int checklen;
  89
  90         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  91         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  92             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  93                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  94                     __func__, rpm->rpm_len);
  95                 return (1);
  96         }
  97         /* rpm->rpm_code must be valid value */
  98         switch (rpm->rpm_code) {
  99         case RPM_PCO_ADD:
 100         case RPM_PCO_CHANGE:
 101         case RPM_PCO_SETGLOBAL:
 102                 break;
 103         default:
 104                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
 105                     rpm->rpm_code);
 106                 return (1);
 107         }
 108         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 109         if (rpm->rpm_matchlen > 128) {
 110                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 111                     __func__, rpm->rpm_matchlen);
 112                 return (1);
 113         }
 114
 115         /*
 116          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 117          * between 0 and 128 inclusive
 118          */
 119         for (rpu = (struct rr_pco_use *)(rpm + 1),
 120              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 121              rpu < rpulim;
 122              rpu += 1) {
 123                 checklen = rpu->rpu_uselen;
 124                 checklen += rpu->rpu_keeplen;
 125                 /*
 126                  * omit these check, because either of rpu_uselen
 127                  * and rpu_keeplen is unsigned char
 128                  *  (128 > rpu_uselen > 0)
 129                  *  (128 > rpu_keeplen > 0)
 130                  *  (rpu_uselen + rpu_keeplen > 0)
 131                  */
 132                 if (checklen > 128) {
 133                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 134                             " rpu_keeplen %d is %d(over 128)",
 135                             __func__, rpu->rpu_uselen, rpu->rpu_keeplen,
 136                             rpu->rpu_uselen + rpu->rpu_keeplen);
 137                         return (1);
 138                 }
 139         }
 140         return (0);
 141 }
 142
 143 static void
 144 do_use_prefix(int len, struct rr_pco_match *rpm,
 145         struct in6_rrenumreq *irr, int ifindex)
 146 {
 147         struct rr_pco_use *rpu, *rpulim;
 148         struct rainfo *rai;
 149         struct ifinfo *ifi;
 150         struct prefix *pfx;
 151
 152         rpu = (struct rr_pco_use *)(rpm + 1);
 153         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 154
 155         if (rpu == rpulim) {    /* no use prefix */
 156                 if (rpm->rpm_code == RPM_PCO_ADD)
 157                         return;
 158
 159                 irr->irr_u_uselen = 0;
 160                 irr->irr_u_keeplen = 0;
 161                 irr->irr_raf_mask_onlink = 0;
 162                 irr->irr_raf_mask_auto = 0;
 163                 irr->irr_vltime = 0;
 164                 irr->irr_pltime = 0;
 165                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 166                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 167                 irr->irr_useprefix.sin6_family = 0;
 168                 irr->irr_useprefix.sin6_addr = in6addr_any;
 169                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 170                     errno != EADDRNOTAVAIL)
 171                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 172                             strerror(errno));
 173                 return;
 174         }
 175
 176         for (rpu = (struct rr_pco_use *)(rpm + 1),
 177              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 178              rpu < rpulim;
 179              rpu += 1) {
 180                 /* init in6_rrenumreq fields */
 181                 irr->irr_u_uselen = rpu->rpu_uselen;
 182                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 183                 irr->irr_raf_mask_onlink =
 184                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 185                 irr->irr_raf_mask_auto =
 186                     !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 187                 irr->irr_vltime = ntohl(rpu->rpu_vltime);
 188                 irr->irr_pltime = ntohl(rpu->rpu_pltime);
 189                 irr->irr_raf_onlink =
 190                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ?
 191                     0 : 1;
 192                 irr->irr_raf_auto =
 193                     (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ?
 194                     0 : 1;
 195                 irr->irr_rrf_decrvalid =
 196                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ?
 197                     0 : 1;
 198                 irr->irr_rrf_decrprefd =
 199                     (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ?
 200                     0 : 1;
 201                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 202                 irr->irr_useprefix.sin6_family = AF_INET6;
 203                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 204
 205                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 206                     errno != EADDRNOTAVAIL)
 207                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 208                             strerror(errno));
 209
 210                 /* very adhoc: should be rewritten */
 211                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 212                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 213                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 214                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 215                         ifi = if_indextoifinfo(ifindex);
 216                         if (ifi == NULL || ifi->ifi_rainfo == NULL)
 217                                 continue; /* non-advertising IF */
 218                         rai = ifi->ifi_rainfo;
 219
 220                         TAILQ_FOREACH(pfx, &rai->rai_prefix, pfx_next) {
 221                                 struct timespec now;
 222
 223                                 if (prefix_match(&pfx->pfx_prefix,
 224                                     pfx->pfx_prefixlen, &rpm->rpm_prefix,
 225                                     rpm->rpm_matchlen)) {
 226                                         /* change parameters */
 227                                         pfx->pfx_validlifetime =
 228                                             ntohl(rpu->rpu_vltime);
 229                                         pfx->pfx_preflifetime =
 230                                             ntohl(rpu->rpu_pltime);
 231                                         if (irr->irr_rrf_decrvalid) {
 232                                                 clock_gettime(CLOCK_MONOTONIC_FAST,
 233                                                     &now);
 234                                                 pfx->pfx_vltimeexpire =
 235                                                     now.tv_sec +
 236                                                     pfx->pfx_validlifetime;
 237                                         } else
 238                                                 pfx->pfx_vltimeexpire = 0;
 239                                         if (irr->irr_rrf_decrprefd) {
 240                                                 clock_gettime(CLOCK_MONOTONIC_FAST,
 241                                                     &now);
 242                                                 pfx->pfx_pltimeexpire =
 243                                                     now.tv_sec +
 244                                                     pfx->pfx_preflifetime;
 245                                         } else
 246                                                 pfx->pfx_pltimeexpire = 0;
 247                                 }
 248                         }
 249                 }
 250         }
 251 }
 252
 253 /*
 254  * process a Prefix Control Operation(PCO).
 255  * return 0 on success, 1 on failure
 256  */
 257 static int
 258 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 259 {
 260         int ifindex = 0;
 261         struct in6_rrenumreq irr;
 262         struct ifinfo *ifi;
 263
 264         if ((rr_pco_check(len, rpm) != 0))
 265                 return (1);
 266
 267         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 268                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 269                     strerror(errno));
 270                 exit(1);
 271         }
 272
 273         memset(&irr, 0, sizeof(irr));
 274         irr.irr_origin = PR_ORIG_RR;
 275         irr.irr_m_len = rpm->rpm_matchlen;
 276         irr.irr_m_minlen = rpm->rpm_minlen;
 277         irr.irr_m_maxlen = rpm->rpm_maxlen;
 278         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 279         irr.irr_matchprefix.sin6_family = AF_INET6;
 280         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 281
 282         while (if_indextoname(++ifindex, irr.irr_name)) {
 283                 ifi = if_indextoifinfo(ifindex);
 284                 if (ifi == NULL) {
 285                         syslog(LOG_ERR, "<%s> ifindex not found.",
 286                             __func__);
 287                         return (1);
 288                 }
 289                 /*
 290                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and
 291                  * IFF_UP is off, the interface is not applied
 292                  */
 293                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 294                     (ifi->ifi_flags & IFF_UP) == 0)
 295                         continue;
 296                 /* TODO: interface scope check */
 297                 do_use_prefix(len, rpm, &irr, ifindex);
 298         }
 299         if (errno == ENXIO)
 300                 return (0);
 301         else if (errno) {
 302                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 303                     strerror(errno));
 304                 return (1);
 305         }
 306         return (0);
 307 }
 308
 309 /*
 310  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 311  * Router Renumbering Command packet.
 312  * return 0 on success, 1 on failure
 313  */
 314 static int
 315 do_rr(int len, struct icmp6_router_renum *rr)
 316 {
 317         struct rr_pco_match *rpm;
 318         char *cp, *lim;
 319
 320         lim = (char *)rr + len;
 321         cp = (char *)(rr + 1);
 322         len -= sizeof(struct icmp6_router_renum);
 323
 324         update_ifinfo(&ifilist, UPDATE_IFINFO_ALL);
 325
 326         while (cp < lim) {
 327                 int rpmlen;
 328
 329                 rpm = (struct rr_pco_match *)cp;
 330                 if ((size_t)len < sizeof(struct rr_pco_match)) {
 331                     tooshort:
 332                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 333                             "garbage at end of pkt?", __func__, len);
 334                         return (1);
 335                 }
 336                 rpmlen = rpm->rpm_len << 3;
 337                 if (len < rpmlen)
 338                         goto tooshort;
 339
 340                 if (do_pco(rr, rpmlen, rpm)) {
 341                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 342                         goto next;
 343                 }
 344
 345             next:
 346                 cp += rpmlen;
 347                 len -= rpmlen;
 348         }
 349
 350         return (0);
 351 }
 352
 353 /*
 354  * check validity of a router renumbering command packet
 355  * return 0 on success, 1 on failure
 356  */
 357 static int
 358 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 359         struct in6_addr *dst)
 360 {
 361         u_char ntopbuf[INET6_ADDRSTRLEN];
 362
 363         /* omit rr minimal length check. hope kernel have done it. */
 364         /* rr_command length check */
 365         if ((size_t)len < (sizeof(struct icmp6_router_renum) +
 366             sizeof(struct rr_pco_match))) {
 367                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 368                     __func__, len);
 369                 return (1);
 370         }
 371
 372         /* destination check. only for multicast. omit unicast check. */
 373         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 374             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 375                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 376                     __func__,
 377                     inet_ntop(AF_INET6, dst, ntopbuf, sizeof(ntopbuf)));
 378                 return (1);
 379         }
 380
 381         /* seqnum and segnum check */
 382         if (rro.rro_seqnum > rr->rr_seqnum) {
 383                 syslog(LOG_WARNING,
 384                     "<%s> rcvd old seqnum %d from %s",
 385                     __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 386                    inet_ntop(AF_INET6, from, ntopbuf, sizeof(ntopbuf)));
 387                 return (1);
 388         }
 389         if (rro.rro_seqnum == rr->rr_seqnum &&
 390             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 391             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 392                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 393                         syslog(LOG_WARNING,
 394                             "<%s> rcvd duped segnum %d from %s",
 395                             __func__, rr->rr_segnum, inet_ntop(AF_INET6, from,
 396                                 ntopbuf, sizeof(ntopbuf)));
 397                 return (0);
 398         }
 399
 400         /* update seqnum */
 401         if (rro.rro_seqnum != rr->rr_seqnum) {
 402                 /* then must be "<" */
 403
 404                 /* init rro_segnum_bits */
 405                 memset(rro.rro_segnum_bits, 0,
 406                     sizeof(rro.rro_segnum_bits));
 407         }
 408         rro.rro_seqnum = rr->rr_seqnum;
 409
 410         return (0);
 411 }
 412
 413 static void
 414 rr_command_input(int len, struct icmp6_router_renum *rr,
 415         struct in6_addr *from, struct in6_addr *dst)
 416 {
 417         /* rr_command validity check */
 418         if (rr_command_check(len, rr, from, dst))
 419                 goto failed;
 420         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 421             ICMP6_RR_FLAGS_TEST)
 422                 return;
 423
 424         /* do router renumbering */
 425         if (do_rr(len, rr))
 426                 goto failed;
 427
 428         /* update segnum */
 429         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 430
 431         return;
 432
 433     failed:
 434         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 435         return;
 436 }
 437
 438 void
 439 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 440         struct sockaddr_in6 *from, struct in6_addr *dst)
 441 {
 442         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 443
 444         syslog(LOG_DEBUG,
 445             "<%s> RR received from %s to %s on %s",
 446             __func__,
 447             inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0] ,sizeof(ntopbuf[0])),
 448             inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 449             if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 450
 451         /* packet validation based on Section 4.1 of RFC2894 */
 452         if ((size_t)len < sizeof(struct icmp6_router_renum)) {
 453                 syslog(LOG_NOTICE,
 454                     "<%s>: RR short message (size %d) from %s to %s on %s",
 455                     __func__, len,
 456                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[0],
 457                         sizeof(ntopbuf[0])),
 458                     inet_ntop(AF_INET6, &dst, ntopbuf[1], sizeof(ntopbuf[1])),
 459                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 460                 return;
 461         }
 462
 463         /*
 464          * If the IPv6 destination address is neither an All Routers multicast
 465          * address [AARCH] nor one of the receiving router's unicast addresses,
 466          * the message MUST be discarded and SHOULD be logged to network
 467          * management.
 468          * We rely on the kernel input routine for unicast addresses, and thus
 469          * check multicast destinations only.
 470          */
 471         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) && !IN6_ARE_ADDR_EQUAL(
 472             &sin6_sitelocal_allrouters.sin6_addr, &pi->ipi6_addr)) {
 473                 syslog(LOG_NOTICE,
 474                     "<%s>: RR message with invalid destination (%s) "
 475                     "from %s on %s",
 476                     __func__,
 477                     inet_ntop(AF_INET6, &dst, ntopbuf[0], sizeof(ntopbuf[0])),
 478                     inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf[1],
 479                               sizeof(ntopbuf[1])),
 480                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 481                 return;
 482         }
 483
 484         rr_rcvifindex = pi->ipi6_ifindex;
 485
 486         switch (rr->rr_code) {
 487         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 488                 rr_command_input(len, rr, &from->sin6_addr, dst);
 489                 /* TODO: send reply msg */
 490                 break;
 491         case ICMP6_ROUTER_RENUMBERING_RESULT:
 492                 /* RESULT will be processed by rrenumd */
 493                 break;
 494         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 495                 /* TODO: sequence number reset */
 496                 break;
 497         default:
 498                 syslog(LOG_ERR, "<%s> received unknown code %d",
 499                     __func__, rr->rr_code);
 500                 break;
 501
 502         }
 503
 504         return;
 505 }