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