rtadvd.tproj/rrenum.c

   1 /*      $KAME: rrenum.c,v 1.12 2002/06/10 19:59:47 itojun Exp $ */
   2
   3 /*
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31 #include <sys/types.h>
  32 #include <sys/param.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/socket.h>
  35 #include <sys/sysctl.h>
  36
  37 #include <net/if.h>
  38 #include <net/if_var.h>
  39 #include <net/route.h>
  40 #include <netinet/in.h>
  41 #include <netinet/in_var.h>
  42 #include <netinet/icmp6.h>
  43
  44 #include <arpa/inet.h>
  45
  46 #include <errno.h>
  47 #include <string.h>
  48 #include <stdlib.h>
  49 #include <syslog.h>
  50 #include "rtadvd.h"
  51 #include "rrenum.h"
  52 #include "if.h"
  53
  54 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  55         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  56 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  57         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  58
  59 struct rr_operation {
  60         u_long  rro_seqnum;
  61         u_long  rro_segnum_bits[8];
  62 };
  63
  64 static struct rr_operation rro;
  65 static int rr_rcvifindex;
  66 static int rrcmd2pco[RPM_PCO_MAX] = {
  67         0,
  68         SIOCAIFPREFIX_IN6,
  69         SIOCCIFPREFIX_IN6,
  70         SIOCSGIFPREFIX_IN6
  71 };
  72 static int s = -1;
  73
  74 /*
  75  * Check validity of a Prefix Control Operation(PCO).
  76  * Return 0 on success, 1 on failure.
  77  */
  78 static int
  79 rr_pco_check(int len, struct rr_pco_match *rpm)
  80 {
  81         struct rr_pco_use *rpu, *rpulim;
  82         int checklen;
  83
  84         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  85         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  86             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  87                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  88                        __func__, rpm->rpm_len);
  89                 return 1;
  90         }
  91         /* rpm->rpm_code must be valid value */
  92         switch (rpm->rpm_code) {
  93         case RPM_PCO_ADD:
  94         case RPM_PCO_CHANGE:
  95         case RPM_PCO_SETGLOBAL:
  96                 break;
  97         default:
  98                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
  99                        rpm->rpm_code);
 100                 return 1;
 101         }
 102         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 103         if (rpm->rpm_matchlen > 128) {
 104                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 105                        __func__, rpm->rpm_matchlen);
 106                 return 1;
 107         }
 108
 109         /*
 110          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 111          * between 0 and 128 inclusive
 112          */
 113         for (rpu = (struct rr_pco_use *)(rpm + 1),
 114              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 115              rpu < rpulim;
 116              rpu += 1) {
 117                 checklen = rpu->rpu_uselen;
 118                 checklen += rpu->rpu_keeplen;
 119                 /*
 120                  * omit these check, because either of rpu_uselen
 121                  * and rpu_keeplen is unsigned char
 122                  *  (128 > rpu_uselen > 0)
 123                  *  (128 > rpu_keeplen > 0)
 124                  *  (rpu_uselen + rpu_keeplen > 0)
 125                  */
 126                 if (checklen > 128) {
 127                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 128                                " rpu_keeplen %d is %d(over 128)",
 129                                __func__, rpu->rpu_uselen,
 130                                rpu->rpu_keeplen,
 131                                rpu->rpu_uselen + rpu->rpu_keeplen);
 132                         return 1;
 133                 }
 134         }
 135         return 0;
 136 }
 137
 138 static void
 139 do_use_prefix(int len, struct rr_pco_match *rpm,
 140               struct in6_rrenumreq *irr, int ifindex)
 141 {
 142         struct rr_pco_use *rpu, *rpulim;
 143         struct rainfo *rai;
 144         struct prefix *pp;
 145
 146         rpu = (struct rr_pco_use *)(rpm + 1);
 147         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 148
 149         if (rpu == rpulim) {    /* no use prefix */
 150                 if (rpm->rpm_code == RPM_PCO_ADD)
 151                         return;
 152
 153                 irr->irr_u_uselen = 0;
 154                 irr->irr_u_keeplen = 0;
 155                 irr->irr_raf_mask_onlink = 0;
 156                 irr->irr_raf_mask_auto = 0;
 157                 irr->irr_vltime = 0;
 158                 irr->irr_pltime = 0;
 159                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 160                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 161                 irr->irr_useprefix.sin6_family = 0;
 162                 irr->irr_useprefix.sin6_addr = in6addr_any;
 163                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 164                     errno != EADDRNOTAVAIL)
 165                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 166                                strerror(errno));
 167                 return;
 168         }
 169
 170         for (rpu = (struct rr_pco_use *)(rpm + 1),
 171              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 172              rpu < rpulim;
 173              rpu += 1) {
 174                 /* init in6_rrenumreq fields */
 175                 irr->irr_u_uselen = rpu->rpu_uselen;
 176                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 177                 irr->irr_raf_mask_onlink =
 178                         !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
 179                 irr->irr_raf_mask_auto =
 180                         !!(rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 181                 irr->irr_vltime = ntohl(rpu->rpu_vltime);
 182                 irr->irr_pltime = ntohl(rpu->rpu_pltime);
 183                 irr->irr_raf_onlink =
 184                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
 185                 irr->irr_raf_auto =
 186                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
 187                 irr->irr_rrf_decrvalid =
 188                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
 189                 irr->irr_rrf_decrprefd =
 190                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
 191                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 192                 irr->irr_useprefix.sin6_family = AF_INET6;
 193                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 194
 195                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 196                     errno != EADDRNOTAVAIL)
 197                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 198                                strerror(errno));
 199
 200                 /* very adhoc: should be rewritten */
 201                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 202                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 203                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 204                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 205                         if ((rai = if_indextorainfo(ifindex)) == NULL)
 206                                 continue; /* non-advertising IF */
 207
 208                         for (pp = rai->prefix.next; pp != &rai->prefix;
 209                              pp = pp->next) {
 210                                 struct timeval now;
 211
 212                                 if (prefix_match(&pp->prefix, pp->prefixlen,
 213                                                  &rpm->rpm_prefix,
 214                                                  rpm->rpm_matchlen)) {
 215                                         /* change parameters */
 216                                         pp->validlifetime = ntohl(rpu->rpu_vltime);
 217                                         pp->preflifetime = ntohl(rpu->rpu_pltime);
 218                                         if (irr->irr_rrf_decrvalid) {
 219                                                 gettimeofday(&now, 0);
 220                                                 pp->vltimeexpire =
 221                                                         now.tv_sec + pp->validlifetime;
 222                                         } else
 223                                                 pp->vltimeexpire = 0;
 224                                         if (irr->irr_rrf_decrprefd) {
 225                                                 gettimeofday(&now, 0);
 226                                                 pp->pltimeexpire =
 227                                                         now.tv_sec + pp->preflifetime;
 228                                         } else
 229                                                 pp->pltimeexpire = 0;
 230                                 }
 231                         }
 232                 }
 233         }
 234 }
 235
 236 /*
 237  * process a Prefix Control Operation(PCO).
 238  * return 0 on success, 1 on failure
 239  */
 240 static int
 241 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 242 {
 243         int ifindex = 0;
 244         struct in6_rrenumreq irr;
 245
 246         if ((rr_pco_check(len, rpm) != 0))
 247                 return 1;
 248
 249         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 250                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 251                        strerror(errno));
 252                 exit(1);
 253         }
 254
 255         memset(&irr, 0, sizeof(irr));
 256         irr.irr_origin = PR_ORIG_RR;
 257         irr.irr_m_len = rpm->rpm_matchlen;
 258         irr.irr_m_minlen = rpm->rpm_minlen;
 259         irr.irr_m_maxlen = rpm->rpm_maxlen;
 260         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 261         irr.irr_matchprefix.sin6_family = AF_INET6;
 262         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 263
 264         while (if_indextoname(++ifindex, irr.irr_name)) {
 265                 /*
 266                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
 267                  * the interface is not applied
 268                  */
 269                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 270                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
 271                         continue;
 272                 /* TODO: interface scope check */
 273                 do_use_prefix(len, rpm, &irr, ifindex);
 274         }
 275         if (errno == ENXIO)
 276                 return 0;
 277         else if (errno) {
 278                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 279                        strerror(errno));
 280                 return 1;
 281         }
 282         return 0;
 283 }
 284
 285 /*
 286  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 287  * Router Renumbering Command packet.
 288  * return 0 on success, 1 on failure
 289  */
 290 static int
 291 do_rr(int len, struct icmp6_router_renum *rr)
 292 {
 293         struct rr_pco_match *rpm;
 294         char *cp, *lim;
 295
 296         lim = (char *)rr + len;
 297         cp = (char *)(rr + 1);
 298         len -= sizeof(struct icmp6_router_renum);
 299
 300         /* get iflist block from kernel again, to get up-to-date information */
 301         init_iflist();
 302
 303         while (cp < lim) {
 304                 int rpmlen;
 305
 306                 rpm = (struct rr_pco_match *)cp;
 307                 if (len < sizeof(struct rr_pco_match)) {
 308                     tooshort:
 309                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 310                                "gabage at end of pkt?", __func__, len);
 311                         return 1;
 312                 }
 313                 rpmlen = rpm->rpm_len << 3;
 314                 if (len < rpmlen)
 315                         goto tooshort;
 316
 317                 if (do_pco(rr, rpmlen, rpm)) {
 318                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 319                         goto next;
 320                 }
 321
 322             next:
 323                 cp += rpmlen;
 324                 len -= rpmlen;
 325         }
 326
 327         return 0;
 328 }
 329
 330 /*
 331  * check validity of a router renumbering command packet
 332  * return 0 on success, 1 on failure
 333  */
 334 static int
 335 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 336                  struct in6_addr *dst)
 337 {
 338         char ntopbuf[INET6_ADDRSTRLEN];
 339
 340         /* omit rr minimal length check. hope kernel have done it. */
 341         /* rr_command length check */
 342         if (len < (sizeof(struct icmp6_router_renum) +
 343                    sizeof(struct rr_pco_match))) {
 344                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 345                        __func__, len);
 346                 return 1;
 347         }
 348
 349         /* destination check. only for multicast. omit unicast check. */
 350         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 351             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 352                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 353                        __func__,
 354                        inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
 355                 return 1;
 356         }
 357
 358         /* seqnum and segnum check */
 359         if (rro.rro_seqnum > rr->rr_seqnum) {
 360                 syslog(LOG_WARNING,
 361                        "<%s> rcvd old seqnum %d from %s",
 362                        __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 363                        inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
 364                 return 1;
 365         }
 366         if (rro.rro_seqnum == rr->rr_seqnum &&
 367             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 368             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 369                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 370                         syslog(LOG_WARNING,
 371                                "<%s> rcvd duped segnum %d from %s",
 372                                __func__, rr->rr_segnum,
 373                                inet_ntop(AF_INET6, from, ntopbuf,
 374                                          INET6_ADDRSTRLEN));
 375                 return 0;
 376         }
 377
 378         /* update seqnum */
 379         if (rro.rro_seqnum != rr->rr_seqnum) {
 380                 /* then must be "<" */
 381
 382                 /* init rro_segnum_bits */
 383                 memset(rro.rro_segnum_bits, 0,
 384                        sizeof(rro.rro_segnum_bits));
 385         }
 386         rro.rro_seqnum = rr->rr_seqnum;
 387
 388         return 0;
 389 }
 390
 391 static void
 392 rr_command_input(int len, struct icmp6_router_renum *rr,
 393                  struct in6_addr *from, struct in6_addr *dst)
 394 {
 395         /* rr_command validity check */
 396         if (rr_command_check(len, rr, from, dst))
 397                 goto failed;
 398         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 399             ICMP6_RR_FLAGS_TEST)
 400                 return;
 401
 402         /* do router renumbering */
 403         if (do_rr(len, rr)) {
 404                 goto failed;
 405         }
 406
 407         /* update segnum */
 408         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 409
 410         return;
 411
 412     failed:
 413         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 414         return;
 415 }
 416
 417 void
 418 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 419          struct sockaddr_in6 *from, struct in6_addr *dst)
 420 {
 421         char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 422
 423         syslog(LOG_DEBUG,
 424                "<%s> RR received from %s to %s on %s",
 425                __func__,
 426                inet_ntop(AF_INET6, &from->sin6_addr,
 427                          ntopbuf[0], INET6_ADDRSTRLEN),
 428                inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 429                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 430
 431         /* packet validation based on Section 4.1 of RFC2894 */
 432         if (len < sizeof(struct icmp6_router_renum)) {
 433                 syslog(LOG_NOTICE,
 434                        "<%s>: RR short message (size %d) from %s to %s on %s",
 435                        __func__, len,
 436                        inet_ntop(AF_INET6, &from->sin6_addr,
 437                                  ntopbuf[0], INET6_ADDRSTRLEN),
 438                        inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 439                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 440                 return;
 441         }
 442
 443         /*
 444          * If the IPv6 destination address is neither an All Routers multicast
 445          * address [AARCH] nor one of the receiving router's unicast addresses,
 446          * the message MUST be discarded and SHOULD be logged to network
 447          * management.
 448          * We rely on the kernel input routine for unicast addresses, and thus
 449          * check multicast destinations only.
 450          */
 451         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
 452             !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
 453                 syslog(LOG_NOTICE,
 454                        "<%s>: RR message with invalid destination (%s) "
 455                        "from %s on %s",
 456                        __func__,
 457                        inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
 458                        inet_ntop(AF_INET6, &from->sin6_addr,
 459                                  ntopbuf[1], INET6_ADDRSTRLEN),
 460                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 461                 return;
 462         }
 463
 464         rr_rcvifindex = pi->ipi6_ifindex;
 465
 466         switch (rr->rr_code) {
 467         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 468                 rr_command_input(len, rr, &from->sin6_addr, dst);
 469                 /* TODO: send reply msg */
 470                 break;
 471         case ICMP6_ROUTER_RENUMBERING_RESULT:
 472                 /* RESULT will be processed by rrenumd */
 473                 break;
 474         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 475                 /* TODO: sequence number reset */
 476                 break;
 477         default:
 478                 syslog(LOG_ERR, "<%s> received unknown code %d",
 479                        __func__, rr->rr_code);
 480                 break;
 481
 482         }
 483
 484         return;
 485 }