bsd/netinet6/esp_input.c

   1 /*      $FreeBSD: src/sys/netinet6/esp_input.c,v 1.1.2.3 2001/07/03 11:01:50 ume Exp $  */
   2 /*      $KAME: esp_input.c,v 1.55 2001/03/23 08:08:47 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
  33 /*
  34  * RFC1827/2406 Encapsulated Security Payload.
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/malloc.h>
  40 #include <sys/mbuf.h>
  41 #include <sys/domain.h>
  42 #include <sys/protosw.h>
  43 #include <sys/socket.h>
  44 #include <sys/errno.h>
  45 #include <sys/time.h>
  46 #include <sys/kernel.h>
  47 #include <sys/syslog.h>
  48
  49 #include <net/if.h>
  50 #include <net/route.h>
  51 #include <net/netisr.h>
  52 #include <kern/cpu_number.h>
  53
  54 #include <netinet/in.h>
  55 #include <netinet/in_systm.h>
  56 #include <netinet/ip.h>
  57 #include <netinet/ip_var.h>
  58 #include <netinet/in_var.h>
  59 #include <netinet/ip_ecn.h>
  60 #include <netinet/in_pcb.h>
  61 #if INET6
  62 #include <netinet6/ip6_ecn.h>
  63 #endif
  64
  65 #if INET6
  66 #include <netinet/ip6.h>
  67 #include <netinet6/in6_pcb.h>
  68 #include <netinet6/ip6_var.h>
  69 #include <netinet/icmp6.h>
  70 #include <netinet6/ip6protosw.h>
  71 #endif
  72
  73 #include <netinet6/ipsec.h>
  74 #if INET6
  75 #include <netinet6/ipsec6.h>
  76 #endif
  77 #include <netinet6/ah.h>
  78 #if INET6
  79 #include <netinet6/ah6.h>
  80 #endif
  81 #include <netinet6/esp.h>
  82 #if INET6
  83 #include <netinet6/esp6.h>
  84 #endif
  85 #include <netkey/key.h>
  86 #include <netkey/keydb.h>
  87 #include <netkey/key_debug.h>
  88
  89
  90 #include <net/net_osdep.h>
  91
  92 #define IPLEN_FLIPPED
  93
  94 #if INET
  95 extern struct protosw inetsw[];
  96
  97 #define ESPMAXLEN \
  98         (sizeof(struct esp) < sizeof(struct newesp) \
  99                 ? sizeof(struct newesp) : sizeof(struct esp))
 100
 101 void
 102 esp4_input(m, off)
 103         struct mbuf *m;
 104         int off;
 105 {
 106         struct ip *ip;
 107         struct esp *esp;
 108         struct esptail esptail;
 109         u_int32_t spi;
 110         struct secasvar *sav = NULL;
 111         size_t taillen;
 112         u_int16_t nxt;
 113         const struct esp_algorithm *algo;
 114         int ivlen;
 115         size_t hlen;
 116         size_t esplen;
 117         int s;
 118
 119         /* sanity check for alignment. */
 120         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 121                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 122                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 123                 ipsecstat.in_inval++;
 124                 goto bad;
 125         }
 126
 127         if (m->m_len < off + ESPMAXLEN) {
 128                 m = m_pullup(m, off + ESPMAXLEN);
 129                 if (!m) {
 130                         ipseclog((LOG_DEBUG,
 131                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 132                         ipsecstat.in_inval++;
 133                         goto bad;
 134                 }
 135         }
 136
 137         ip = mtod(m, struct ip *);
 138         esp = (struct esp *)(((u_int8_t *)ip) + off);
 139 #ifdef _IP_VHL
 140         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 141 #else
 142         hlen = ip->ip_hl << 2;
 143 #endif
 144
 145         /* find the sassoc. */
 146         spi = esp->esp_spi;
 147
 148         if ((sav = key_allocsa(AF_INET,
 149                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 150                               IPPROTO_ESP, spi)) == 0) {
 151                 ipseclog((LOG_WARNING,
 152                     "IPv4 ESP input: no key association found for spi %u\n",
 153                     (u_int32_t)ntohl(spi)));
 154                 ipsecstat.in_nosa++;
 155                 goto bad;
 156         }
 157         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 158                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 159         if (sav->state != SADB_SASTATE_MATURE
 160          && sav->state != SADB_SASTATE_DYING) {
 161                 ipseclog((LOG_DEBUG,
 162                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 163                     (u_int32_t)ntohl(spi)));
 164                 ipsecstat.in_badspi++;
 165                 goto bad;
 166         }
 167         algo = esp_algorithm_lookup(sav->alg_enc);
 168         if (!algo) {
 169                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 170                     "unsupported encryption algorithm for spi %u\n",
 171                     (u_int32_t)ntohl(spi)));
 172                 ipsecstat.in_badspi++;
 173                 goto bad;
 174         }
 175
 176         /* check if we have proper ivlen information */
 177         ivlen = sav->ivlen;
 178         if (ivlen < 0) {
 179                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 180                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 181                 ipsecstat.in_inval++;
 182                 goto bad;
 183         }
 184
 185         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 186          && (sav->alg_auth && sav->key_auth)))
 187                 goto noreplaycheck;
 188
 189         if (sav->alg_auth == SADB_X_AALG_NULL ||
 190             sav->alg_auth == SADB_AALG_NONE)
 191                 goto noreplaycheck;
 192
 193         /*
 194          * check for sequence number.
 195          */
 196         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 197                 ; /*okey*/
 198         else {
 199                 ipsecstat.in_espreplay++;
 200                 ipseclog((LOG_WARNING,
 201                     "replay packet in IPv4 ESP input: %s %s\n",
 202                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 203                 goto bad;
 204         }
 205
 206         /* check ICV */
 207     {
 208         u_char sum0[AH_MAXSUMSIZE];
 209         u_char sum[AH_MAXSUMSIZE];
 210         const struct ah_algorithm *sumalgo;
 211         size_t siz;
 212
 213         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 214         if (!sumalgo)
 215                 goto noreplaycheck;
 216         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 217         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 218                 ipsecstat.in_inval++;
 219                 goto bad;
 220         }
 221         if (AH_MAXSUMSIZE < siz) {
 222                 ipseclog((LOG_DEBUG,
 223                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 224                     (u_long)siz));
 225                 ipsecstat.in_inval++;
 226                 goto bad;
 227         }
 228
 229         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 230
 231         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 232                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 233                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 234                 ipsecstat.in_espauthfail++;
 235                 goto bad;
 236         }
 237
 238         if (bcmp(sum0, sum, siz) != 0) {
 239                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 240                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 241                 ipsecstat.in_espauthfail++;
 242                 goto bad;
 243         }
 244
 245         /* strip off the authentication data */
 246         m_adj(m, -siz);
 247         ip = mtod(m, struct ip *);
 248 #ifdef IPLEN_FLIPPED
 249         ip->ip_len = ip->ip_len - siz;
 250 #else
 251         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 252 #endif
 253         m->m_flags |= M_AUTHIPDGM;
 254         ipsecstat.in_espauthsucc++;
 255     }
 256
 257         /*
 258          * update sequence number.
 259          */
 260         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 261                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 262                         ipsecstat.in_espreplay++;
 263                         goto bad;
 264                 }
 265         }
 266
 267 noreplaycheck:
 268
 269         /* process main esp header. */
 270         if (sav->flags & SADB_X_EXT_OLD) {
 271                 /* RFC 1827 */
 272                 esplen = sizeof(struct esp);
 273         } else {
 274                 /* RFC 2406 */
 275                 if (sav->flags & SADB_X_EXT_DERIV)
 276                         esplen = sizeof(struct esp);
 277                 else
 278                         esplen = sizeof(struct newesp);
 279         }
 280
 281         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 282                 ipseclog((LOG_WARNING,
 283                     "IPv4 ESP input: packet too short\n"));
 284                 ipsecstat.in_inval++;
 285                 goto bad;
 286         }
 287
 288         if (m->m_len < off + esplen + ivlen) {
 289                 m = m_pullup(m, off + esplen + ivlen);
 290                 if (!m) {
 291                         ipseclog((LOG_DEBUG,
 292                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 293                         ipsecstat.in_inval++;
 294                         goto bad;
 295                 }
 296         }
 297
 298         /*
 299          * pre-compute and cache intermediate key
 300          */
 301         if (esp_schedule(algo, sav) != 0) {
 302                 ipsecstat.in_inval++;
 303                 goto bad;
 304         }
 305
 306         /*
 307          * decrypt the packet.
 308          */
 309         if (!algo->decrypt)
 310                 panic("internal error: no decrypt function");
 311         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 312                 /* m is already freed */
 313                 m = NULL;
 314                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 315                     ipsec_logsastr(sav)));
 316                 ipsecstat.in_inval++;
 317                 goto bad;
 318         }
 319         ipsecstat.in_esphist[sav->alg_enc]++;
 320
 321         m->m_flags |= M_DECRYPTED;
 322
 323         /*
 324          * find the trailer of the ESP.
 325          */
 326         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 327              (caddr_t)&esptail);
 328         nxt = esptail.esp_nxt;
 329         taillen = esptail.esp_padlen + sizeof(esptail);
 330
 331         if (m->m_pkthdr.len < taillen
 332          || m->m_pkthdr.len - taillen < hlen) { /*?*/
 333                 ipseclog((LOG_WARNING,
 334                     "bad pad length in IPv4 ESP input: %s %s\n",
 335                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 336                 ipsecstat.in_inval++;
 337                 goto bad;
 338         }
 339
 340         /* strip off the trailing pad area. */
 341         m_adj(m, -taillen);
 342
 343 #ifdef IPLEN_FLIPPED
 344         ip->ip_len = ip->ip_len - taillen;
 345 #else
 346         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 347 #endif
 348
 349         /* was it transmitted over the IPsec tunnel SA? */
 350         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 351                 /*
 352                  * strip off all the headers that precedes ESP header.
 353                  *      IP4 xx ESP IP4' payload -> IP4' payload
 354                  *
 355                  * XXX more sanity checks
 356                  * XXX relationship with gif?
 357                  */
 358                 u_int8_t tos;
 359
 360                 tos = ip->ip_tos;
 361                 m_adj(m, off + esplen + ivlen);
 362                 if (m->m_len < sizeof(*ip)) {
 363                         m = m_pullup(m, sizeof(*ip));
 364                         if (!m) {
 365                                 ipsecstat.in_inval++;
 366                                 goto bad;
 367                         }
 368                 }
 369                 ip = mtod(m, struct ip *);
 370                 /* ECN consideration. */
 371                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 372                 if (!key_checktunnelsanity(sav, AF_INET,
 373                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 374                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 375                             "in IPv4 ESP input: %s %s\n",
 376                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 377                         ipsecstat.in_inval++;
 378                         goto bad;
 379                 }
 380
 381 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 382                 /* drop it if it does not match the default policy */
 383                 if (ipsec4_in_reject(m, NULL)) {
 384                         ipsecstat.in_polvio++;
 385                         goto bad;
 386                 }
 387 #endif
 388
 389                 key_sa_recordxfer(sav, m);
 390                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 391                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 392                         ipsecstat.in_nomem++;
 393                         goto bad;
 394                 }
 395
 396                 s = splimp();
 397                 if (IF_QFULL(&ipintrq)) {
 398                         ipsecstat.in_inval++;
 399                         splx(s);
 400                         goto bad;
 401                 }
 402                 IF_ENQUEUE(&ipintrq, m);
 403                 m = NULL;
 404                 schednetisr(NETISR_IP); /*can be skipped but to make sure*/
 405                 splx(s);
 406                 nxt = IPPROTO_DONE;
 407         } else {
 408                 /*
 409                  * strip off ESP header and IV.
 410                  * even in m_pulldown case, we need to strip off ESP so that
 411                  * we can always compute checksum for AH correctly.
 412                  */
 413                 size_t stripsiz;
 414
 415                 stripsiz = esplen + ivlen;
 416
 417                 ip = mtod(m, struct ip *);
 418                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 419                 m->m_data += stripsiz;
 420                 m->m_len -= stripsiz;
 421                 m->m_pkthdr.len -= stripsiz;
 422
 423                 ip = mtod(m, struct ip *);
 424 #ifdef IPLEN_FLIPPED
 425                 ip->ip_len = ip->ip_len - stripsiz;
 426 #else
 427                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 428 #endif
 429                 ip->ip_p = nxt;
 430
 431                 key_sa_recordxfer(sav, m);
 432                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 433                         ipsecstat.in_nomem++;
 434                         goto bad;
 435                 }
 436
 437                 if (nxt != IPPROTO_DONE) {
 438                         if ((ip_protox[nxt]->pr_flags & PR_LASTHDR) != 0 &&
 439                             ipsec4_in_reject(m, NULL)) {
 440                                 ipsecstat.in_polvio++;
 441                                 goto bad;
 442                         }
 443                         (*ip_protox[nxt]->pr_input)(m, off);
 444                 } else
 445                         m_freem(m);
 446                 m = NULL;
 447         }
 448
 449         if (sav) {
 450                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 451                         printf("DP esp4_input call free SA:%p\n", sav));
 452                 key_freesav(sav);
 453         }
 454         ipsecstat.in_success++;
 455         return;
 456
 457 bad:
 458         if (sav) {
 459                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 460                         printf("DP esp4_input call free SA:%p\n", sav));
 461                 key_freesav(sav);
 462         }
 463         if (m)
 464                 m_freem(m);
 465         return;
 466 }
 467 #endif /* INET */
 468
 469 #if INET6
 470 int
 471 esp6_input(mp, offp, proto)
 472         struct mbuf **mp;
 473         int *offp, proto;
 474 {
 475         struct mbuf *m = *mp;
 476         int off = *offp;
 477         struct ip6_hdr *ip6;
 478         struct esp *esp;
 479         struct esptail esptail;
 480         u_int32_t spi;
 481         struct secasvar *sav = NULL;
 482         size_t taillen;
 483         u_int16_t nxt;
 484         const struct esp_algorithm *algo;
 485         int ivlen;
 486         size_t esplen;
 487         int s;
 488
 489         /* sanity check for alignment. */
 490         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 491                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 492                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 493                 ipsec6stat.in_inval++;
 494                 goto bad;
 495         }
 496
 497 #ifndef PULLDOWN_TEST
 498         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 499         esp = (struct esp *)(mtod(m, caddr_t) + off);
 500 #else
 501         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 502         if (esp == NULL) {
 503                 ipsec6stat.in_inval++;
 504                 return IPPROTO_DONE;
 505         }
 506 #endif
 507         ip6 = mtod(m, struct ip6_hdr *);
 508
 509         if (ntohs(ip6->ip6_plen) == 0) {
 510                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 511                     "ESP with IPv6 jumbogram is not supported.\n"));
 512                 ipsec6stat.in_inval++;
 513                 goto bad;
 514         }
 515
 516         /* find the sassoc. */
 517         spi = esp->esp_spi;
 518
 519         if ((sav = key_allocsa(AF_INET6,
 520                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 521                               IPPROTO_ESP, spi)) == 0) {
 522                 ipseclog((LOG_WARNING,
 523                     "IPv6 ESP input: no key association found for spi %u\n",
 524                     (u_int32_t)ntohl(spi)));
 525                 ipsec6stat.in_nosa++;
 526                 goto bad;
 527         }
 528         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 529                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 530         if (sav->state != SADB_SASTATE_MATURE
 531          && sav->state != SADB_SASTATE_DYING) {
 532                 ipseclog((LOG_DEBUG,
 533                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 534                     (u_int32_t)ntohl(spi)));
 535                 ipsec6stat.in_badspi++;
 536                 goto bad;
 537         }
 538         algo = esp_algorithm_lookup(sav->alg_enc);
 539         if (!algo) {
 540                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 541                     "unsupported encryption algorithm for spi %u\n",
 542                     (u_int32_t)ntohl(spi)));
 543                 ipsec6stat.in_badspi++;
 544                 goto bad;
 545         }
 546
 547         /* check if we have proper ivlen information */
 548         ivlen = sav->ivlen;
 549         if (ivlen < 0) {
 550                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 551                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 552                 ipsec6stat.in_badspi++;
 553                 goto bad;
 554         }
 555
 556         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 557          && (sav->alg_auth && sav->key_auth)))
 558                 goto noreplaycheck;
 559
 560         if (sav->alg_auth == SADB_X_AALG_NULL ||
 561             sav->alg_auth == SADB_AALG_NONE)
 562                 goto noreplaycheck;
 563
 564         /*
 565          * check for sequence number.
 566          */
 567         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 568                 ; /*okey*/
 569         else {
 570                 ipsec6stat.in_espreplay++;
 571                 ipseclog((LOG_WARNING,
 572                     "replay packet in IPv6 ESP input: %s %s\n",
 573                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 574                 goto bad;
 575         }
 576
 577         /* check ICV */
 578     {
 579         u_char sum0[AH_MAXSUMSIZE];
 580         u_char sum[AH_MAXSUMSIZE];
 581         const struct ah_algorithm *sumalgo;
 582         size_t siz;
 583
 584         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 585         if (!sumalgo)
 586                 goto noreplaycheck;
 587         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 588         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 589                 ipsecstat.in_inval++;
 590                 goto bad;
 591         }
 592         if (AH_MAXSUMSIZE < siz) {
 593                 ipseclog((LOG_DEBUG,
 594                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 595                     (u_long)siz));
 596                 ipsec6stat.in_inval++;
 597                 goto bad;
 598         }
 599
 600         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 601
 602         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 603                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 604                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 605                 ipsec6stat.in_espauthfail++;
 606                 goto bad;
 607         }
 608
 609         if (bcmp(sum0, sum, siz) != 0) {
 610                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 611                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 612                 ipsec6stat.in_espauthfail++;
 613                 goto bad;
 614         }
 615
 616         /* strip off the authentication data */
 617         m_adj(m, -siz);
 618         ip6 = mtod(m, struct ip6_hdr *);
 619         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 620
 621         m->m_flags |= M_AUTHIPDGM;
 622         ipsec6stat.in_espauthsucc++;
 623     }
 624
 625         /*
 626          * update sequence number.
 627          */
 628         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 629                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 630                         ipsec6stat.in_espreplay++;
 631                         goto bad;
 632                 }
 633         }
 634
 635 noreplaycheck:
 636
 637         /* process main esp header. */
 638         if (sav->flags & SADB_X_EXT_OLD) {
 639                 /* RFC 1827 */
 640                 esplen = sizeof(struct esp);
 641         } else {
 642                 /* RFC 2406 */
 643                 if (sav->flags & SADB_X_EXT_DERIV)
 644                         esplen = sizeof(struct esp);
 645                 else
 646                         esplen = sizeof(struct newesp);
 647         }
 648
 649         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 650                 ipseclog((LOG_WARNING,
 651                     "IPv6 ESP input: packet too short\n"));
 652                 ipsec6stat.in_inval++;
 653                 goto bad;
 654         }
 655
 656 #ifndef PULLDOWN_TEST
 657         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /*XXX*/
 658 #else
 659         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 660         if (esp == NULL) {
 661                 ipsec6stat.in_inval++;
 662                 m = NULL;
 663                 goto bad;
 664         }
 665 #endif
 666         ip6 = mtod(m, struct ip6_hdr *);        /*set it again just in case*/
 667
 668         /*
 669          * pre-compute and cache intermediate key
 670          */
 671         if (esp_schedule(algo, sav) != 0) {
 672                 ipsec6stat.in_inval++;
 673                 goto bad;
 674         }
 675
 676         /*
 677          * decrypt the packet.
 678          */
 679         if (!algo->decrypt)
 680                 panic("internal error: no decrypt function");
 681         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 682                 /* m is already freed */
 683                 m = NULL;
 684                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 685                     ipsec_logsastr(sav)));
 686                 ipsec6stat.in_inval++;
 687                 goto bad;
 688         }
 689         ipsec6stat.in_esphist[sav->alg_enc]++;
 690
 691         m->m_flags |= M_DECRYPTED;
 692
 693         /*
 694          * find the trailer of the ESP.
 695          */
 696         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 697              (caddr_t)&esptail);
 698         nxt = esptail.esp_nxt;
 699         taillen = esptail.esp_padlen + sizeof(esptail);
 700
 701         if (m->m_pkthdr.len < taillen
 702          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /*?*/
 703                 ipseclog((LOG_WARNING,
 704                     "bad pad length in IPv6 ESP input: %s %s\n",
 705                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 706                 ipsec6stat.in_inval++;
 707                 goto bad;
 708         }
 709
 710         /* strip off the trailing pad area. */
 711         m_adj(m, -taillen);
 712
 713         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 714
 715         /* was it transmitted over the IPsec tunnel SA? */
 716         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 717                 /*
 718                  * strip off all the headers that precedes ESP header.
 719                  *      IP6 xx ESP IP6' payload -> IP6' payload
 720                  *
 721                  * XXX more sanity checks
 722                  * XXX relationship with gif?
 723                  */
 724                 u_int32_t flowinfo;     /*net endian*/
 725                 flowinfo = ip6->ip6_flow;
 726                 m_adj(m, off + esplen + ivlen);
 727                 if (m->m_len < sizeof(*ip6)) {
 728 #ifndef PULLDOWN_TEST
 729                         /*
 730                          * m_pullup is prohibited in KAME IPv6 input processing
 731                          * but there's no other way!
 732                          */
 733 #else
 734                         /* okay to pullup in m_pulldown style */
 735 #endif
 736                         m = m_pullup(m, sizeof(*ip6));
 737                         if (!m) {
 738                                 ipsec6stat.in_inval++;
 739                                 goto bad;
 740                         }
 741                 }
 742                 ip6 = mtod(m, struct ip6_hdr *);
 743                 /* ECN consideration. */
 744                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 745                 if (!key_checktunnelsanity(sav, AF_INET6,
 746                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 747                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 748                             "in IPv6 ESP input: %s %s\n",
 749                             ipsec6_logpacketstr(ip6, spi),
 750                             ipsec_logsastr(sav)));
 751                         ipsec6stat.in_inval++;
 752                         goto bad;
 753                 }
 754
 755 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 756                 /* drop it if it does not match the default policy */
 757                 if (ipsec6_in_reject(m, NULL)) {
 758                         ipsec6stat.in_polvio++;
 759                         goto bad;
 760                 }
 761 #endif
 762
 763                 key_sa_recordxfer(sav, m);
 764                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 765                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 766                         ipsec6stat.in_nomem++;
 767                         goto bad;
 768                 }
 769
 770                 s = splimp();
 771                 if (IF_QFULL(&ip6intrq)) {
 772                         ipsec6stat.in_inval++;
 773                         splx(s);
 774                         goto bad;
 775                 }
 776                 IF_ENQUEUE(&ip6intrq, m);
 777                 m = NULL;
 778                 schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
 779                 splx(s);
 780                 nxt = IPPROTO_DONE;
 781         } else {
 782                 /*
 783                  * strip off ESP header and IV.
 784                  * even in m_pulldown case, we need to strip off ESP so that
 785                  * we can always compute checksum for AH correctly.
 786                  */
 787                 size_t stripsiz;
 788                 char *prvnxtp;
 789
 790                 /*
 791                  * Set the next header field of the previous header correctly.
 792                  */
 793                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 794                 *prvnxtp = nxt;
 795
 796                 stripsiz = esplen + ivlen;
 797
 798                 ip6 = mtod(m, struct ip6_hdr *);
 799                 if (m->m_len >= stripsiz + off) {
 800                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 801                         m->m_data += stripsiz;
 802                         m->m_len -= stripsiz;
 803                         m->m_pkthdr.len -= stripsiz;
 804                 } else {
 805                         /*
 806                          * this comes with no copy if the boundary is on
 807                          * cluster
 808                          */
 809                         struct mbuf *n;
 810
 811                         n = m_split(m, off, M_DONTWAIT);
 812                         if (n == NULL) {
 813                                 /* m is retained by m_split */
 814                                 goto bad;
 815                         }
 816                         m_adj(n, stripsiz);
 817                         m_cat(m, n);
 818                         /* m_cat does not update m_pkthdr.len */
 819                         m->m_pkthdr.len += n->m_pkthdr.len;
 820                 }
 821
 822 #ifndef PULLDOWN_TEST
 823                 /*
 824                  * KAME requires that the packet to be contiguous on the
 825                  * mbuf.  We need to make that sure.
 826                  * this kind of code should be avoided.
 827                  * XXX other conditions to avoid running this part?
 828                  */
 829                 if (m->m_len != m->m_pkthdr.len) {
 830                         struct mbuf *n = NULL;
 831                         int maxlen;
 832
 833                         MGETHDR(n, M_DONTWAIT, MT_HEADER);
 834                         maxlen = MHLEN;
 835                         if (n)
 836                                 M_COPY_PKTHDR(n, m);
 837                         if (n && m->m_pkthdr.len > maxlen) {
 838                                 MCLGET(n, M_DONTWAIT);
 839                                 maxlen = MCLBYTES;
 840                                 if ((n->m_flags & M_EXT) == 0) {
 841                                         m_free(n);
 842                                         n = NULL;
 843                                 }
 844                         }
 845                         if (!n) {
 846                                 printf("esp6_input: mbuf allocation failed\n");
 847                                 goto bad;
 848                         }
 849
 850                         if (m->m_pkthdr.len <= maxlen) {
 851                                 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
 852                                 n->m_len = m->m_pkthdr.len;
 853                                 n->m_pkthdr.len = m->m_pkthdr.len;
 854                                 n->m_next = NULL;
 855                                 m_freem(m);
 856                         } else {
 857                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 858                                 m_adj(m, maxlen);
 859                                 n->m_len = maxlen;
 860                                 n->m_pkthdr.len = m->m_pkthdr.len;
 861                                 n->m_next = m;
 862                                 m->m_flags &= ~M_PKTHDR;
 863                         }
 864                         m = n;
 865                 }
 866 #endif
 867
 868                 ip6 = mtod(m, struct ip6_hdr *);
 869                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 870
 871                 key_sa_recordxfer(sav, m);
 872                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 873                         ipsec6stat.in_nomem++;
 874                         goto bad;
 875                 }
 876         }
 877
 878         *offp = off;
 879         *mp = m;
 880
 881         if (sav) {
 882                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 883                         printf("DP esp6_input call free SA:%p\n", sav));
 884                 key_freesav(sav);
 885         }
 886         ipsec6stat.in_success++;
 887         return nxt;
 888
 889 bad:
 890         if (sav) {
 891                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 892                         printf("DP esp6_input call free SA:%p\n", sav));
 893                 key_freesav(sav);
 894         }
 895         if (m)
 896                 m_freem(m);
 897         return IPPROTO_DONE;
 898 }
 899
 900 void
 901 esp6_ctlinput(cmd, sa, d)
 902         int cmd;
 903         struct sockaddr *sa;
 904         void *d;
 905 {
 906         const struct newesp *espp;
 907         struct newesp esp;
 908         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 909         struct secasvar *sav;
 910         struct ip6_hdr *ip6;
 911         struct mbuf *m;
 912         int off;
 913         struct sockaddr_in6 sa6_src, sa6_dst;
 914
 915         if (sa->sa_family != AF_INET6 ||
 916             sa->sa_len != sizeof(struct sockaddr_in6))
 917                 return;
 918         if ((unsigned)cmd >= PRC_NCMDS)
 919                 return;
 920
 921         /* if the parameter is from icmp6, decode it. */
 922         if (d != NULL) {
 923                 ip6cp = (struct ip6ctlparam *)d;
 924                 m = ip6cp->ip6c_m;
 925                 ip6 = ip6cp->ip6c_ip6;
 926                 off = ip6cp->ip6c_off;
 927         } else {
 928                 m = NULL;
 929                 ip6 = NULL;
 930         }
 931
 932         if (ip6) {
 933                 /*
 934                  * Notify the error to all possible sockets via pfctlinput2.
 935                  * Since the upper layer information (such as protocol type,
 936                  * source and destination ports) is embedded in the encrypted
 937                  * data and might have been cut, we can't directly call
 938                  * an upper layer ctlinput function. However, the pcbnotify
 939                  * function will consider source and destination addresses
 940                  * as well as the flow info value, and may be able to find
 941                  * some PCB that should be notified.
 942                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 943                  * no possibility of an infinite loop of function calls,
 944                  * because we don't pass the inner IPv6 header.
 945                  */
 946                 bzero(&ip6cp1, sizeof(ip6cp1));
 947                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 948                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 949
 950                 /*
 951                  * Then go to special cases that need ESP header information.
 952                  * XXX: We assume that when ip6 is non NULL,
 953                  * M and OFF are valid.
 954                  */
 955
 956                 /* check if we can safely examine src and dst ports */
 957                 if (m->m_pkthdr.len < off + sizeof(esp))
 958                         return;
 959
 960                 if (m->m_len < off + sizeof(esp)) {
 961                         /*
 962                          * this should be rare case,
 963                          * so we compromise on this copy...
 964                          */
 965                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 966                         espp = &esp;
 967                 } else
 968                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 969
 970                 if (cmd == PRC_MSGSIZE) {
 971                         int valid = 0;
 972
 973                         /*
 974                          * Check to see if we have a valid SA corresponding to
 975                          * the address in the ICMP message payload.
 976                          */
 977                         sav = key_allocsa(AF_INET6,
 978                                           (caddr_t)&sa6_src.sin6_addr,
 979                                           (caddr_t)&sa6_dst, IPPROTO_ESP,
 980                                           espp->esp_spi);
 981                         if (sav) {
 982                                 if (sav->state == SADB_SASTATE_MATURE ||
 983                                     sav->state == SADB_SASTATE_DYING)
 984                                         valid++;
 985                                 key_freesav(sav);
 986                         }
 987
 988                         /* XXX Further validation? */
 989
 990                         /*
 991                          * Depending on the value of "valid" and routing table
 992                          * size (mtudisc_{hi,lo}wat), we will:
 993                          * - recalcurate the new MTU and create the
 994                          *   corresponding routing entry, or
 995                          * - ignore the MTU change notification.
 996                          */
 997                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 998                 }
 999         } else {
1000                 /* we normally notify any pcb here */
1001         }
1002 }
1003 #endif /* INET6 */