usr.sbin/rtadvd/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  * $DragonFly: src/usr.sbin/rtadvd/rrenum.c,v 1.5 2008/06/05 18:06:33 swildner Exp $
  33  */
  34 #include <sys/types.h>
  35 #include <sys/param.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/socket.h>
  38 #include <sys/sysctl.h>
  39
  40 #include <net/if.h>
  41 #if defined(__DragonFly__)
  42 #include <net/if_var.h>
  43 #endif /* __DragonFly__ */
  44 #include <net/route.h>
  45 #include <netinet/in.h>
  46 #include <netinet/in_var.h>
  47 #include <netinet/icmp6.h>
  48
  49 #include <arpa/inet.h>
  50
  51 #include <errno.h>
  52 #include <string.h>
  53 #include <stdlib.h>
  54 #include <syslog.h>
  55 #include "rtadvd.h"
  56 #include "rrenum.h"
  57 #include "if.h"
  58
  59 #define RR_ISSET_SEGNUM(segnum_bits, segnum) \
  60         ((((segnum_bits)[(segnum) >> 5]) & (1 << ((segnum) & 31))) != 0)
  61 #define RR_SET_SEGNUM(segnum_bits, segnum) \
  62         (((segnum_bits)[(segnum) >> 5]) |= (1 << ((segnum) & 31)))
  63
  64 struct rr_operation {
  65         u_long  rro_seqnum;
  66         u_long  rro_segnum_bits[8];
  67 };
  68
  69 static struct rr_operation rro;
  70 static int rr_rcvifindex;
  71 static int rrcmd2pco[RPM_PCO_MAX] = {
  72         0,
  73         SIOCAIFPREFIX_IN6,
  74         SIOCCIFPREFIX_IN6,
  75         SIOCSGIFPREFIX_IN6
  76 };
  77 static int s = -1;
  78
  79 /*
  80  * Check validity of a Prefix Control Operation(PCO).
  81  * Return 0 on success, 1 on failure.
  82  */
  83 static int
  84 rr_pco_check(int len, struct rr_pco_match *rpm)
  85 {
  86         struct rr_pco_use *rpu, *rpulim;
  87         int checklen;
  88
  89         /* rpm->rpm_len must be (4N * 3) as router-renum-05.txt */
  90         if ((rpm->rpm_len - 3) < 0 || /* must be at least 3 */
  91             (rpm->rpm_len - 3) & 0x3) { /* must be multiple of 4 */
  92                 syslog(LOG_WARNING, "<%s> rpm_len %d is not 4N * 3",
  93                        __func__, rpm->rpm_len);
  94                 return 1;
  95         }
  96         /* rpm->rpm_code must be valid value */
  97         switch(rpm->rpm_code) {
  98         case RPM_PCO_ADD:
  99         case RPM_PCO_CHANGE:
 100         case RPM_PCO_SETGLOBAL:
 101                 break;
 102         default:
 103                 syslog(LOG_WARNING, "<%s> unknown rpm_code %d", __func__,
 104                        rpm->rpm_code);
 105                 return 1;
 106         }
 107         /* rpm->rpm_matchlen must be 0 to 128 inclusive */
 108         if (rpm->rpm_matchlen > 128) {
 109                 syslog(LOG_WARNING, "<%s> rpm_matchlen %d is over 128",
 110                        __func__, rpm->rpm_matchlen);
 111                 return 1;
 112         }
 113
 114         /*
 115          * rpu->rpu_uselen, rpu->rpu_keeplen, and sum of them must be
 116          * between 0 and 128 inclusive
 117          */
 118         for (rpu = (struct rr_pco_use *)(rpm + 1),
 119              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 120              rpu < rpulim;
 121              rpu += 1) {
 122                 checklen = rpu->rpu_uselen;
 123                 checklen += rpu->rpu_keeplen;
 124                 /*
 125                  * omit these check, because either of rpu_uselen
 126                  * and rpu_keeplen is unsigned char
 127                  *  (128 > rpu_uselen > 0)
 128                  *  (128 > rpu_keeplen > 0)
 129                  *  (rpu_uselen + rpu_keeplen > 0)
 130                  */
 131                 if (checklen > 128) {
 132                         syslog(LOG_WARNING, "<%s> sum of rpu_uselen %d and"
 133                                " rpu_keeplen %d is %d(over 128)",
 134                                __func__, rpu->rpu_uselen,
 135                                rpu->rpu_keeplen,
 136                                rpu->rpu_uselen + rpu->rpu_keeplen);
 137                         return 1;
 138                 }
 139         }
 140         return 0;
 141 }
 142
 143 static void
 144 do_use_prefix(int len, struct rr_pco_match *rpm,
 145               struct in6_rrenumreq *irr, int ifindex)
 146 {
 147         struct rr_pco_use *rpu, *rpulim;
 148         struct rainfo *rai;
 149         struct prefix *pp;
 150
 151         rpu = (struct rr_pco_use *)(rpm + 1);
 152         rpulim = (struct rr_pco_use *)((char *)rpm + len);
 153
 154         if (rpu == rpulim) {    /* no use prefix */
 155                 if (rpm->rpm_code == RPM_PCO_ADD)
 156                         return;
 157
 158                 irr->irr_u_uselen = 0;
 159                 irr->irr_u_keeplen = 0;
 160                 irr->irr_raf_mask_onlink = 0;
 161                 irr->irr_raf_mask_auto = 0;
 162                 irr->irr_vltime = 0;
 163                 irr->irr_pltime = 0;
 164                 memset(&irr->irr_flags, 0, sizeof(irr->irr_flags));
 165                 irr->irr_useprefix.sin6_len = 0; /* let it mean, no addition */
 166                 irr->irr_useprefix.sin6_family = 0;
 167                 irr->irr_useprefix.sin6_addr = in6addr_any;
 168                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 169                     errno != EADDRNOTAVAIL)
 170                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 171                                strerror(errno));
 172                 return;
 173         }
 174
 175         for (rpu = (struct rr_pco_use *)(rpm + 1),
 176              rpulim = (struct rr_pco_use *)((char *)rpm + len);
 177              rpu < rpulim;
 178              rpu += 1) {
 179                 /* init in6_rrenumreq fields */
 180                 irr->irr_u_uselen = rpu->rpu_uselen;
 181                 irr->irr_u_keeplen = rpu->rpu_keeplen;
 182                 irr->irr_raf_mask_onlink =
 183                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
 184                 irr->irr_raf_mask_auto =
 185                         (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
 186                 irr->irr_vltime = ntohl(rpu->rpu_vltime);
 187                 irr->irr_pltime = ntohl(rpu->rpu_pltime);
 188                 irr->irr_raf_onlink =
 189                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
 190                 irr->irr_raf_auto =
 191                         (rpu->rpu_raflags & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
 192                 irr->irr_rrf_decrvalid =
 193                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRVLTIME) == 0 ? 0 : 1;
 194                 irr->irr_rrf_decrprefd =
 195                         (rpu->rpu_flags & ICMP6_RR_PCOUSE_FLAGS_DECRPLTIME) == 0 ? 0 : 1;
 196                 irr->irr_useprefix.sin6_len = sizeof(irr->irr_useprefix);
 197                 irr->irr_useprefix.sin6_family = AF_INET6;
 198                 irr->irr_useprefix.sin6_addr = rpu->rpu_prefix;
 199
 200                 if (ioctl(s, rrcmd2pco[rpm->rpm_code], (caddr_t)irr) < 0 &&
 201                     errno != EADDRNOTAVAIL)
 202                         syslog(LOG_ERR, "<%s> ioctl: %s", __func__,
 203                                strerror(errno));
 204
 205                 /* very adhoc: should be rewritten */
 206                 if (rpm->rpm_code == RPM_PCO_CHANGE &&
 207                     IN6_ARE_ADDR_EQUAL(&rpm->rpm_prefix, &rpu->rpu_prefix) &&
 208                     rpm->rpm_matchlen == rpu->rpu_uselen &&
 209                     rpu->rpu_uselen == rpu->rpu_keeplen) {
 210                         if ((rai = if_indextorainfo(ifindex)) == NULL)
 211                                 continue; /* non-advertising IF */
 212
 213                         for (pp = rai->prefix.next; pp != &rai->prefix;
 214                              pp = pp->next) {
 215                                 struct timeval now;
 216
 217                                 if (prefix_match(&pp->prefix, pp->prefixlen,
 218                                                  &rpm->rpm_prefix,
 219                                                  rpm->rpm_matchlen)) {
 220                                         /* change parameters */
 221                                         pp->validlifetime = ntohl(rpu->rpu_vltime);
 222                                         pp->preflifetime = ntohl(rpu->rpu_pltime);
 223                                         if (irr->irr_rrf_decrvalid) {
 224                                                 gettimeofday(&now, 0);
 225                                                 pp->vltimeexpire =
 226                                                         now.tv_sec + pp->validlifetime;
 227                                         } else
 228                                                 pp->vltimeexpire = 0;
 229                                         if (irr->irr_rrf_decrprefd) {
 230                                                 gettimeofday(&now, 0);
 231                                                 pp->pltimeexpire =
 232                                                         now.tv_sec + pp->preflifetime;
 233                                         } else
 234                                                 pp->pltimeexpire = 0;
 235                                 }
 236                         }
 237                 }
 238         }
 239 }
 240
 241 /*
 242  * process a Prefix Control Operation(PCO).
 243  * return 0 on success, 1 on failure
 244  */
 245 static int
 246 do_pco(struct icmp6_router_renum *rr, int len, struct rr_pco_match *rpm)
 247 {
 248         int ifindex = 0;
 249         struct in6_rrenumreq irr;
 250
 251         if ((rr_pco_check(len, rpm) != 0))
 252                 return 1;
 253
 254         if (s == -1 && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 255                 syslog(LOG_ERR, "<%s> socket: %s", __func__,
 256                        strerror(errno));
 257                 exit(1);
 258         }
 259
 260         memset(&irr, 0, sizeof(irr));
 261         irr.irr_origin = PR_ORIG_RR;
 262         irr.irr_m_len = rpm->rpm_matchlen;
 263         irr.irr_m_minlen = rpm->rpm_minlen;
 264         irr.irr_m_maxlen = rpm->rpm_maxlen;
 265         irr.irr_matchprefix.sin6_len = sizeof(irr.irr_matchprefix);
 266         irr.irr_matchprefix.sin6_family = AF_INET6;
 267         irr.irr_matchprefix.sin6_addr = rpm->rpm_prefix;
 268
 269         while (if_indextoname(++ifindex, irr.irr_name)) {
 270                 /*
 271                  * if ICMP6_RR_FLAGS_FORCEAPPLY(A flag) is 0 and IFF_UP is off,
 272                  * the interface is not applied
 273                  */
 274                 if ((rr->rr_flags & ICMP6_RR_FLAGS_FORCEAPPLY) == 0 &&
 275                     (iflist[ifindex]->ifm_flags & IFF_UP) == 0)
 276                         continue;
 277                 /* TODO: interface scope check */
 278                 do_use_prefix(len, rpm, &irr, ifindex);
 279         }
 280         if (errno == ENXIO)
 281                 return 0;
 282         else if (errno) {
 283                 syslog(LOG_ERR, "<%s> if_indextoname: %s", __func__,
 284                        strerror(errno));
 285                 return 1;
 286         }
 287         return 0;
 288 }
 289
 290 /*
 291  * call do_pco() for each Prefix Control Operations(PCOs) in a received
 292  * Router Renumbering Command packet.
 293  * return 0 on success, 1 on failure
 294  */
 295 static int
 296 do_rr(int len, struct icmp6_router_renum *rr)
 297 {
 298         struct rr_pco_match *rpm;
 299         char *cp, *lim;
 300
 301         lim = (char *)rr + len;
 302         cp = (char *)(rr + 1);
 303         len -= sizeof(struct icmp6_router_renum);
 304
 305         /* get iflist block from kernel again, to get up-to-date information */
 306         init_iflist();
 307
 308         while (cp < lim) {
 309                 int rpmlen;
 310
 311                 rpm = (struct rr_pco_match *)cp;
 312                 if (len < sizeof(struct rr_pco_match)) {
 313                     tooshort:
 314                         syslog(LOG_ERR, "<%s> pkt too short. left len = %d. "
 315                                "gabage at end of pkt?", __func__, len);
 316                         return 1;
 317                 }
 318                 rpmlen = rpm->rpm_len << 3;
 319                 if (len < rpmlen)
 320                         goto tooshort;
 321
 322                 if (do_pco(rr, rpmlen, rpm)) {
 323                         syslog(LOG_WARNING, "<%s> invalid PCO", __func__);
 324                         goto next;
 325                 }
 326
 327             next:
 328                 cp += rpmlen;
 329                 len -= rpmlen;
 330         }
 331
 332         return 0;
 333 }
 334
 335 /*
 336  * check validity of a router renumbering command packet
 337  * return 0 on success, 1 on failure
 338  */
 339 static int
 340 rr_command_check(int len, struct icmp6_router_renum *rr, struct in6_addr *from,
 341                  struct in6_addr *dst)
 342 {
 343         u_char ntopbuf[INET6_ADDRSTRLEN];
 344
 345         /* omit rr minimal length check. hope kernel have done it. */
 346         /* rr_command length check */
 347         if (len < (sizeof(struct icmp6_router_renum) +
 348                    sizeof(struct rr_pco_match))) {
 349                 syslog(LOG_ERR, "<%s> rr_command len %d is too short",
 350                        __func__, len);
 351                 return 1;
 352         }
 353
 354         /* destination check. only for multicast. omit unicast check. */
 355         if (IN6_IS_ADDR_MULTICAST(dst) && !IN6_IS_ADDR_MC_LINKLOCAL(dst) &&
 356             !IN6_IS_ADDR_MC_SITELOCAL(dst)) {
 357                 syslog(LOG_ERR, "<%s> dst mcast addr %s is illegal",
 358                        __func__,
 359                        inet_ntop(AF_INET6, dst, ntopbuf, INET6_ADDRSTRLEN));
 360                 return 1;
 361         }
 362
 363         /* seqnum and segnum check */
 364         if (rro.rro_seqnum > rr->rr_seqnum) {
 365                 syslog(LOG_WARNING,
 366                        "<%s> rcvd old seqnum %d from %s",
 367                        __func__, (u_int32_t)ntohl(rr->rr_seqnum),
 368                        inet_ntop(AF_INET6, from, ntopbuf, INET6_ADDRSTRLEN));
 369                 return 1;
 370         }
 371         if (rro.rro_seqnum == rr->rr_seqnum &&
 372             (rr->rr_flags & ICMP6_RR_FLAGS_TEST) == 0 &&
 373             RR_ISSET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum)) {
 374                 if ((rr->rr_flags & ICMP6_RR_FLAGS_REQRESULT) != 0)
 375                         syslog(LOG_WARNING,
 376                                "<%s> rcvd duped segnum %d from %s",
 377                                __func__, rr->rr_segnum,
 378                                inet_ntop(AF_INET6, from, ntopbuf,
 379                                          INET6_ADDRSTRLEN));
 380                 return 0;
 381         }
 382
 383         /* update seqnum */
 384         if (rro.rro_seqnum != rr->rr_seqnum) {
 385                 /* then must be "<" */
 386
 387                 /* init rro_segnum_bits */
 388                 memset(rro.rro_segnum_bits, 0,
 389                        sizeof(rro.rro_segnum_bits));
 390         }
 391         rro.rro_seqnum = rr->rr_seqnum;
 392
 393         return 0;
 394 }
 395
 396 static void
 397 rr_command_input(int len, struct icmp6_router_renum *rr,
 398                  struct in6_addr *from, struct in6_addr *dst)
 399 {
 400         /* rr_command validity check */
 401         if (rr_command_check(len, rr, from, dst))
 402                 goto failed;
 403         if ((rr->rr_flags & (ICMP6_RR_FLAGS_TEST|ICMP6_RR_FLAGS_REQRESULT)) ==
 404             ICMP6_RR_FLAGS_TEST)
 405                 return;
 406
 407         /* do router renumbering */
 408         if (do_rr(len, rr)) {
 409                 goto failed;
 410         }
 411
 412         /* update segnum */
 413         RR_SET_SEGNUM(rro.rro_segnum_bits, rr->rr_segnum);
 414
 415         return;
 416
 417     failed:
 418         syslog(LOG_ERR, "<%s> received RR was invalid", __func__);
 419         return;
 420 }
 421
 422 void
 423 rr_input(int len, struct icmp6_router_renum *rr, struct in6_pktinfo *pi,
 424          struct sockaddr_in6 *from, struct in6_addr *dst)
 425 {
 426         u_char ntopbuf[2][INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 427
 428         syslog(LOG_DEBUG,
 429                "<%s> RR received from %s to %s on %s",
 430                __func__,
 431                inet_ntop(AF_INET6, &from->sin6_addr,
 432                          ntopbuf[0], INET6_ADDRSTRLEN),
 433                inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 434                if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 435
 436         /* packet validation based on Section 4.1 of RFC2894 */
 437         if (len < sizeof(struct icmp6_router_renum)) {
 438                 syslog(LOG_NOTICE,
 439                        "<%s>: RR short message (size %d) from %s to %s on %s",
 440                        __func__, len,
 441                        inet_ntop(AF_INET6, &from->sin6_addr,
 442                                  ntopbuf[0], INET6_ADDRSTRLEN),
 443                        inet_ntop(AF_INET6, &dst, ntopbuf[1], INET6_ADDRSTRLEN),
 444                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 445                 return;
 446         }
 447
 448         /*
 449          * If the IPv6 destination address is neither an All Routers multicast
 450          * address [AARCH] nor one of the receiving router's unicast addresses,
 451          * the message MUST be discarded and SHOULD be logged to network
 452          * management.
 453          * We rely on the kernel input routine for unicast addresses, and thus
 454          * check multicast destinations only.
 455          */
 456         if (IN6_IS_ADDR_MULTICAST(&pi->ipi6_addr) &&
 457             !IN6_ARE_ADDR_EQUAL(&in6a_site_allrouters, &pi->ipi6_addr)) {
 458                 syslog(LOG_NOTICE,
 459                        "<%s>: RR message with invalid destination (%s) "
 460                        "from %s on %s",
 461                        __func__,
 462                        inet_ntop(AF_INET6, &dst, ntopbuf[0], INET6_ADDRSTRLEN),
 463                        inet_ntop(AF_INET6, &from->sin6_addr,
 464                                  ntopbuf[1], INET6_ADDRSTRLEN),
 465                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 466                 return;
 467         }
 468
 469         rr_rcvifindex = pi->ipi6_ifindex;
 470
 471         switch (rr->rr_code) {
 472         case ICMP6_ROUTER_RENUMBERING_COMMAND:
 473                 rr_command_input(len, rr, &from->sin6_addr, dst);
 474                 /* TODO: send reply msg */
 475                 break;
 476         case ICMP6_ROUTER_RENUMBERING_RESULT:
 477                 /* RESULT will be processed by rrenumd */
 478                 break;
 479         case ICMP6_ROUTER_RENUMBERING_SEQNUM_RESET:
 480                 /* TODO: sequence number reset */
 481                 break;
 482         default:
 483                 syslog(LOG_ERR, "<%s> received unknown code %d",
 484                        __func__, rr->rr_code);
 485                 break;
 486
 487         }
 488
 489         return;
 490 }