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