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 <string.h>
  49 #include <stdlib.h>
  50 #include <syslog.h>
  51 #include "rtadvd.h"
  52 #include "rrenum.h"
  53 #include "if.h"
  54
  55 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  56         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  57 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  58         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  59
  60 struct rr_operation {
  61         u_long  rro_seqnum;
  62         u_long  rro_segnum_bits[8];
  63 };
  64
  65 static struct rr_operation rro;
  66 static int rr_rcvifindex;
  67 static int rrcmd2pco[RPM_PCO_MAX] = {
  68         0,
  69         SIOCAIFPREFIX_IN6,
  70         SIOCCIFPREFIX_IN6,
  71         SIOCSGIFPREFIX_IN6
  72 };
  73 static int s = -1;
  74
  75 /*
  76  * Check validity of a Prefix Control Operation(PCO).
  77  * Return 0 on success, 1 on failure.
  78  */
  79 static int
  80 rr_pco_check(int len, struct rr_pco_match *rpm)
  81 {
  82         struct rr_pco_use *rpu, *rpulim;
  83         int checklen;
  84
  85         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  86         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  87             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  88                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  89                        __func__, rpm->rpm_len);
  90                 return 1;
  91         }
  92         /* rpm->rpm_code must be valid value */
  93         switch (rpm->rpm_code) {
  94         case RPM_PCO_ADD:
  95         case RPM_PCO_CHANGE:
  96         case RPM_PCO_SETGLOBAL:
  97                 break;
  98         default:
  99                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
 100                        rpm->rpm_code);
 101                 return 1;
 102         }
 103         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 104         if (rpm->rpm_matchlen > 128) {
 105                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 106                        __func__, rpm->rpm_matchlen);
 107                 return 1;
 108         }
 109
 110         /*
 111          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 112          * between 0 and 128 inclusive
 113          */
 114         for (rpu = (struct rr_pco_use *)(rpm + 1),
 115              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 116              rpu < rpulim;
 117              rpu += 1) {
 118                 checklen = rpu->rpu_uselen;
 119                 checklen += rpu->rpu_keeplen;
 120                 /*
 121                  * omit these check, because either of rpu_uselen
 122                  * and rpu_keeplen is unsigned char
 123                  *  (128 > rpu_uselen > 0)
 124                  *  (128 > rpu_keeplen > 0)
 125                  *  (rpu_uselen + rpu_keeplen > 0)
 126                  */
 127                 if (checklen > 128) {
 128                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 129                                " rpu_keeplen %d is %d(over 128)",
 130                                __func__, rpu->rpu_uselen,
 131                                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 *pp;
 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 ? 0 : 1;
 186                 irr->irr_raf_auto =
 187                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
 188                 irr->irr_rrf_decrvalid =
 189                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
 190                 irr->irr_rrf_decrprefd =
 191                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
 192                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 193                 irr->irr_useprefix.sin6_family = AF_INET6;
 194                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 195
 196                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 197                     errno != EADDRNOTAVAIL)
 198                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 199                                strerror(errno));
 200
 201                 /* very adhoc: should be rewritten */
 202                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 203                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 204                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 205                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 206                         if ((rai = if_indextorainfo(ifindex)) == NULL)
 207                                 continue; /* non-advertising IF */
 208
 209                         for (pp = rai->prefix.next; pp != &rai->prefix;
 210                              pp = pp->next) {
 211                                 struct timeval now;
 212
 213                                 if (prefix_match(&pp->prefix, pp->prefixlen,
 214                                                  &rpm->rpm_prefix,
 215                                                  rpm->rpm_matchlen)) {
 216                                         /* change parameters */
 217                                         pp->validlifetime = ntohl(rpu->rpu_vltime);
 218                                         pp->preflifetime = ntohl(rpu->rpu_pltime);
 219                                         if (irr->irr_rrf_decrvalid) {
 220                                                 gettimeofday(&now, 0);
 221                                                 pp->vltimeexpire =
 222                                                         now.tv_sec + pp->validlifetime;
 223                                         } else
 224                                                 pp->vltimeexpire = 0;
 225                                         if (irr->irr_rrf_decrprefd) {
 226                                                 gettimeofday(&now, 0);
 227                                                 pp->pltimeexpire =
 228                                                         now.tv_sec + pp->preflifetime;
 229                                         } else
 230                                                 pp->pltimeexpire = 0;
 231                                 }
 232                         }
 233                 }
 234         }
 235 }
 236
 237 /*
 238  * process a Prefix Control Operation(PCO).
 239  * return 0 on success, 1 on failure
 240  */
 241 static int
 242 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 243 {
 244         int ifindex = 0;
 245         struct in6_rrenumreq irr;
 246
 247         if ((rr_pco_check(len, rpm) != 0))
 248                 return 1;
 249
 250         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 251                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 252                        strerror(errno));
 253                 exit(1);
 254         }
 255
 256         memset(&irr, 0, sizeof(irr));
 257         irr.irr_origin = PR_ORIG_RR;
 258         irr.irr_m_len = rpm->rpm_matchlen;
 259         irr.irr_m_minlen = rpm->rpm_minlen;
 260         irr.irr_m_maxlen = rpm->rpm_maxlen;
 261         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 262         irr.irr_matchprefix.sin6_family = AF_INET6;
 263         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 264
 265         while (if_indextoname(++ifindex, irr.irr_name)) {
 266                 /*
 267                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
 268                  * the interface is not applied
 269                  */
 270                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 271                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
 272                         continue;
 273                 /* TODO: interface scope check */
 274                 do_use_prefix(len, rpm, &irr, ifindex);
 275         }
 276         if (errno == ENXIO)
 277                 return 0;
 278         else if (errno) {
 279                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 280                        strerror(errno));
 281                 return 1;
 282         }
 283         return 0;
 284 }
 285
 286 /*
 287  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 288  * Router Renumbering Command packet.
 289  * return 0 on success, 1 on failure
 290  */
 291 static int
 292 do_rr(int len, struct icmp6_router_renum *rr)
 293 {
 294         struct rr_pco_match *rpm;
 295         char *cp, *lim;
 296
 297         lim = (char *)rr + len;
 298         cp = (char *)(rr + 1);
 299         len -= sizeof(struct icmp6_router_renum);
 300
 301         /* get iflist block from kernel again, to get up-to-date information */
 302         init_iflist();
 303
 304         while (cp < lim) {
 305                 int rpmlen;
 306
 307                 rpm = (struct rr_pco_match *)cp;
 308                 if (len < sizeof(struct rr_pco_match)) {
 309                     tooshort:
 310                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 311                                "gabage at end of pkt?", __func__, len);
 312                         return 1;
 313                 }
 314                 rpmlen = rpm->rpm_len << 3;
 315                 if (len < rpmlen)
 316                         goto tooshort;
 317
 318                 if (do_pco(rr, rpmlen, rpm)) {
 319                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 320                         goto next;
 321                 }
 322
 323             next:
 324                 cp += rpmlen;
 325                 len -= rpmlen;
 326         }
 327
 328         return 0;
 329 }
 330
 331 /*
 332  * check validity of a router renumbering command packet
 333  * return 0 on success, 1 on failure
 334  */
 335 static int
 336 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 337                  struct in6_addr *dst)
 338 {
 339         u_char ntopbuf[INET6_ADDRSTRLEN];
 340
 341         /* omit rr minimal length check. hope kernel have done it. */
 342         /* rr_command length check */
 343         if (len < (sizeof(struct icmp6_router_renum) +
 344                    sizeof(struct rr_pco_match))) {
 345                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 346                        __func__, len);
 347                 return 1;
 348         }
 349
 350         /* destination check. only for multicast. omit unicast check. */
 351         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 352             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 353                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 354                        __func__,
 355                        inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
 356                 return 1;
 357         }
 358
 359         /* seqnum and segnum check */
 360         if (rro.rro_seqnum > rr->rr_seqnum) {
 361                 syslog(LOG_WARNING,
 362                        "<%s> rcvd old seqnum %d from %s",
 363                        __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 364                        inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
 365                 return 1;
 366         }
 367         if (rro.rro_seqnum == rr->rr_seqnum &&
 368             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 369             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 370                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 371                         syslog(LOG_WARNING,
 372                                "<%s> rcvd duped segnum %d from %s",
 373                                __func__, rr->rr_segnum,
 374                                inet_ntop(AF_INET6, from, ntopbuf,
 375                                          INET6_ADDRSTRLEN));
 376                 return 0;
 377         }
 378
 379         /* update seqnum */
 380         if (rro.rro_seqnum != rr->rr_seqnum) {
 381                 /* then must be "<" */
 382
 383                 /* init rro_segnum_bits */
 384                 memset(rro.rro_segnum_bits, 0,
 385                        sizeof(rro.rro_segnum_bits));
 386         }
 387         rro.rro_seqnum = rr->rr_seqnum;
 388
 389         return 0;
 390 }
 391
 392 static void
 393 rr_command_input(int len, struct icmp6_router_renum *rr,
 394                  struct in6_addr *from, struct in6_addr *dst)
 395 {
 396         /* rr_command validity check */
 397         if (rr_command_check(len, rr, from, dst))
 398                 goto failed;
 399         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 400             ICMP6_RR_FLAGS_TEST)
 401                 return;
 402
 403         /* do router renumbering */
 404         if (do_rr(len, rr)) {
 405                 goto failed;
 406         }
 407
 408         /* update segnum */
 409         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 410
 411         return;
 412
 413     failed:
 414         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 415         return;
 416 }
 417
 418 void
 419 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 420          struct sockaddr_in6 *from, struct in6_addr *dst)
 421 {
 422         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 423
 424         syslog(LOG_DEBUG,
 425                "<%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                 syslog(LOG_NOTICE,
 435                        "<%s>: RR short message (size %d) from %s to %s on %s",
 436                        __func__, len,
 437                        inet_ntop(AF_INET6, &from->sin6_addr,
 438                                  ntopbuf[0], INET6_ADDRSTRLEN),
 439                        inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 440                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 441                 return;
 442         }
 443
 444         /*
 445          * If the IPv6 destination address is neither an All Routers multicast
 446          * address [AARCH] nor one of the receiving router's unicast addresses,
 447          * the message MUST be discarded and SHOULD be logged to network
 448          * management.
 449          * We rely on the kernel input routine for unicast addresses, and thus
 450          * check multicast destinations only.
 451          */
 452         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
 453             !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
 454                 syslog(LOG_NOTICE,
 455                        "<%s>: RR message with invalid destination (%s) "
 456                        "from %s on %s",
 457                        __func__,
 458                        inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
 459                        inet_ntop(AF_INET6, &from->sin6_addr,
 460                                  ntopbuf[1], INET6_ADDRSTRLEN),
 461                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 462                 return;
 463         }
 464
 465         rr_rcvifindex = pi->ipi6_ifindex;
 466
 467         switch (rr->rr_code) {
 468         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 469                 rr_command_input(len, rr, &from->sin6_addr, dst);
 470                 /* TODO: send reply msg */
 471                 break;
 472         case ICMP6_ROUTER_RENUMBERING_RESULT:
 473                 /* RESULT will be processed by rrenumd */
 474                 break;
 475         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 476                 /* TODO: sequence number reset */
 477                 break;
 478         default:
 479                 syslog(LOG_ERR, "<%s> received unknown code %d",
 480                        __func__, rr->rr_code);
 481                 break;
 482
 483         }
 484
 485         return;
 486 }