rtadvd.tproj/rrenum.c

   1 /*      $KAME: rrenum.c,v 1.10 2001/01/21 15:32:16 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  * $FreeBSD: src/usr.sbin/rtadvd/rrenum.c,v 1.2.2.2 2001/07/03 11:02:14 ume Exp $
  32  */
  33 #include <sys/types.h>
  34 #include <sys/param.h>
  35 #include <sys/ioctl.h>
  36 #include <sys/socket.h>
  37 #include <sys/sysctl.h>
  38
  39 #include <net/if.h>
  40 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
  41 #include <net/if_var.h>
  42 #endif /* __FreeBSD__ >= 3 */
  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 <string.h>
  52 #include <stdlib.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                        __FUNCTION__, 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", __FUNCTION__,
 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                        __FUNCTION__, 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                                __FUNCTION__, rpu->rpu_uselen,
 134                                rpu->rpu_keeplen,
 135                                rpu->rpu_uselen + rpu->rpu_keeplen);
 136                         return 1;
 137                 }
 138         }
 139         return 0;
 140 }
 141
 142 static void
 143 do_use_prefix(int len, struct rr_pco_match *rpm,
 144               struct in6_rrenumreq *irr, int ifindex)
 145 {
 146         struct rr_pco_use *rpu, *rpulim;
 147         struct rainfo *rai;
 148         struct prefix *pp;
 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", __FUNCTION__,
 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) == 0 ? 0 : 1;
 183                 irr->irr_raf_mask_auto =
 184                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
 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 ? 0 : 1;
 189                 irr->irr_raf_auto =
 190                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
 191                 irr->irr_rrf_decrvalid =
 192                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
 193                 irr->irr_rrf_decrprefd =
 194                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
 195                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 196                 irr->irr_useprefix.sin6_family = AF_INET6;
 197                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 198
 199                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 200                     errno != EADDRNOTAVAIL)
 201                         syslog(LOG_ERR, "<%s> ioctl: %s", __FUNCTION__,
 202                                strerror(errno));
 203
 204                 /* very adhoc: should be rewritten */
 205                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 206                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 207                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 208                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 209                         if ((rai = if_indextorainfo(ifindex)) == NULL)
 210                                 continue; /* non-advertising IF */
 211
 212                         for (pp = rai->prefix.next; pp != &rai->prefix;
 213                              pp = pp->next) {
 214                                 struct timeval now;
 215
 216                                 if (prefix_match(&pp->prefix, pp->prefixlen,
 217                                                  &rpm->rpm_prefix,
 218                                                  rpm->rpm_matchlen)) {
 219                                         /* change parameters */
 220                                         pp->validlifetime = ntohl(rpu->rpu_vltime);
 221                                         pp->preflifetime = ntohl(rpu->rpu_pltime);
 222                                         if (irr->irr_rrf_decrvalid) {
 223                                                 gettimeofday(&now, 0);
 224                                                 pp->vltimeexpire =
 225                                                         now.tv_sec + pp->validlifetime;
 226                                         } else
 227                                                 pp->vltimeexpire = 0;
 228                                         if (irr->irr_rrf_decrprefd) {
 229                                                 gettimeofday(&now, 0);
 230                                                 pp->pltimeexpire =
 231                                                         now.tv_sec + pp->preflifetime;
 232                                         } else
 233                                                 pp->pltimeexpire = 0;
 234                                 }
 235                         }
 236                 }
 237         }
 238 }
 239
 240 /*
 241  * process a Prefix Control Operation(PCO).
 242  * return 0 on success, 1 on failure
 243  */
 244 static int
 245 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 246 {
 247         int ifindex = 0;
 248         struct in6_rrenumreq irr;
 249
 250         if ((rr_pco_check(len, rpm) != 0))
 251                 return 1;
 252
 253         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 254                 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
 255                        strerror(errno));
 256                 exit(1);
 257         }
 258
 259         memset(&irr, 0, sizeof(irr));
 260         irr.irr_origin = PR_ORIG_RR;
 261         irr.irr_m_len = rpm->rpm_matchlen;
 262         irr.irr_m_minlen = rpm->rpm_minlen;
 263         irr.irr_m_maxlen = rpm->rpm_maxlen;
 264         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 265         irr.irr_matchprefix.sin6_family = AF_INET6;
 266         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 267
 268         while (if_indextoname(++ifindex, irr.irr_name)) {
 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                     (iflist[ifindex]->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                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __FUNCTION__,
 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                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 314                                "gabage at end of pkt?", __FUNCTION__, 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                         syslog(LOG_WARNING, "<%s> invalid PCO", __FUNCTION__);
 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         u_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                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 349                        __FUNCTION__, 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                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 357                        __FUNCTION__,
 358                        inet_ntop(AF_INET6, dst, (char *)ntopbuf, INET6_ADDRSTRLEN));
 359                 return 1;
 360         }
 361
 362         /* seqnum and segnum check */
 363         if (rro.rro_seqnum > rr->rr_seqnum) {
 364                 syslog(LOG_WARNING,
 365                        "<%s> rcvd old seqnum %d from %s",
 366                        __FUNCTION__, (u_int32_t)ntohl(rr->rr_seqnum),
 367                        inet_ntop(AF_INET6, from, (char *)ntopbuf, INET6_ADDRSTRLEN));
 368                 return 1;
 369         }
 370         if (rro.rro_seqnum == rr->rr_seqnum &&
 371             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 372             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 373                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 374                         syslog(LOG_WARNING,
 375                                "<%s> rcvd duped segnum %d from %s",
 376                                __FUNCTION__, rr->rr_segnum,
 377                                inet_ntop(AF_INET6, from, (char *)ntopbuf,
 378                                          INET6_ADDRSTRLEN));
 379                 return 0;
 380         }
 381
 382         /* update seqnum */
 383         if (rro.rro_seqnum != rr->rr_seqnum) {
 384                 /* then must be "<" */
 385
 386                 /* init rro_segnum_bits */
 387                 memset(rro.rro_segnum_bits, 0,
 388                        sizeof(rro.rro_segnum_bits));
 389         }
 390         rro.rro_seqnum = rr->rr_seqnum;
 391
 392         return 0;
 393 }
 394
 395 static void
 396 rr_command_input(int len, struct icmp6_router_renum *rr,
 397                  struct in6_addr *from, struct in6_addr *dst)
 398 {
 399         /* rr_command validity check */
 400         if (rr_command_check(len, rr, from, dst))
 401                 goto failed;
 402         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 403             ICMP6_RR_FLAGS_TEST)
 404                 return;
 405
 406         /* do router renumbering */
 407         if (do_rr(len, rr)) {
 408                 goto failed;
 409         }
 410
 411         /* update segnum */
 412         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 413
 414         return;
 415
 416     failed:
 417         syslog(LOG_ERR, "<%s> received RR was invalid", __FUNCTION__);
 418         return;
 419 }
 420
 421 void
 422 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 423          struct sockaddr_in6 *from, struct in6_addr *dst)
 424 {
 425         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 426
 427         syslog(LOG_DEBUG,
 428                "<%s> RR received from %s to %s on %s",
 429                __FUNCTION__,
 430                inet_ntop(AF_INET6, &from->sin6_addr,
 431                          (char *)ntopbuf[0], INET6_ADDRSTRLEN),
 432                inet_ntop(AF_INET6, &dst, (char *)ntopbuf[1], INET6_ADDRSTRLEN),
 433                if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
 434
 435         /* packet validation based on Section 4.1 of RFC2894 */
 436         if (len < sizeof(struct icmp6_router_renum)) {
 437                 syslog(LOG_NOTICE,
 438                        "<%s>: RR short message (size %d) from %s to %s on %s",
 439                        __FUNCTION__, len,
 440                        inet_ntop(AF_INET6, &from->sin6_addr,
 441                                  (char *)ntopbuf[0], INET6_ADDRSTRLEN),
 442                        inet_ntop(AF_INET6, &dst, (char *)ntopbuf[1], INET6_ADDRSTRLEN),
 443                        if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
 444                 return;
 445         }
 446
 447         /*
 448          * If the IPv6 destination address is neither an All Routers multicast
 449          * address [AARCH] nor one of the receiving router's unicast addresses,
 450          * the message MUST be discarded and SHOULD be logged to network
 451          * management.
 452          * We rely on the kernel input routine for unicast addresses, and thus
 453          * check multicast destinations only.
 454          */
 455         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
 456             !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
 457                 syslog(LOG_NOTICE,
 458                        "<%s>: RR message with invalid destination (%s) "
 459                        "from %s on %s",
 460                        __FUNCTION__,
 461                        inet_ntop(AF_INET6, &dst, (char *)ntopbuf[0], INET6_ADDRSTRLEN),
 462                        inet_ntop(AF_INET6, &from->sin6_addr,
 463                                  (char *)ntopbuf[1], INET6_ADDRSTRLEN),
 464                        if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
 465                 return;
 466         }
 467
 468         rr_rcvifindex = pi->ipi6_ifindex;
 469
 470         switch (rr->rr_code) {
 471         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 472                 rr_command_input(len, rr, &from->sin6_addr, dst);
 473                 /* TODO: send reply msg */
 474                 break;
 475         case ICMP6_ROUTER_RENUMBERING_RESULT:
 476                 /* RESULT will be processed by rrenumd */
 477                 break;
 478         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 479                 /* TODO: sequence number reset */
 480                 break;
 481         default:
 482                 syslog(LOG_ERR, "<%s> received unknown code %d",
 483                        __FUNCTION__, rr->rr_code);
 484                 break;
 485
 486         }
 487
 488         return;
 489 }