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