sys/netinet6/esp_input.c

   1 /*      $FreeBSD: src/sys/netinet6/esp_input.c,v 1.1.2.8 2003/01/23 21:06:47 sam Exp $  */
   2 /*      $DragonFly: src/sys/netinet6/esp_input.c,v 1.5 2003/09/15 23:38:14 hsu Exp $    */
   3 /*      $KAME: esp_input.c,v 1.62 2002/01/07 11:39:57 kjc Exp $ */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * RFC1827/2406 Encapsulated Security Payload.
  36  */
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/mbuf.h>
  44 #include <sys/domain.h>
  45 #include <sys/protosw.h>
  46 #include <sys/socket.h>
  47 #include <sys/errno.h>
  48 #include <sys/time.h>
  49 #include <sys/syslog.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53 #include <net/netisr.h>
  54 #include <machine/cpu.h>
  55
  56 #include <netinet/in.h>
  57 #include <netinet/in_systm.h>
  58 #include <netinet/ip.h>
  59 #include <netinet/ip_var.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip_ecn.h>
  62 #ifdef INET6
  63 #include <netinet6/ip6_ecn.h>
  64 #endif
  65
  66 #ifdef INET6
  67 #include <netinet/ip6.h>
  68 #include <netinet6/in6_pcb.h>
  69 #include <netinet6/ip6_var.h>
  70 #include <netinet/icmp6.h>
  71 #include <netinet6/ip6protosw.h>
  72 #endif
  73
  74 #include <netinet6/ipsec.h>
  75 #ifdef INET6
  76 #include <netinet6/ipsec6.h>
  77 #endif
  78 #include <netinet6/ah.h>
  79 #ifdef INET6
  80 #include <netinet6/ah6.h>
  81 #endif
  82 #include <netinet6/esp.h>
  83 #ifdef INET6
  84 #include <netinet6/esp6.h>
  85 #endif
  86 #include <netproto/key/key.h>
  87 #include <netproto/key/keydb.h>
  88 #include <netproto/key/key_debug.h>
  89
  90 #include <machine/stdarg.h>
  91
  92 #include <net/net_osdep.h>
  93
  94 #define IPLEN_FLIPPED
  95
  96 #define ESPMAXLEN \
  97         (sizeof(struct esp) < sizeof(struct newesp) \
  98                 ? sizeof(struct newesp) : sizeof(struct esp))
  99
 100 #ifdef INET
 101 #include <netinet/ipprotosw.h>
 102 extern struct ipprotosw inetsw[];
 103
 104 void
 105 esp4_input(struct mbuf *m, int off, int proto)
 106 {
 107         struct ip *ip;
 108         struct esp *esp;
 109         struct esptail esptail;
 110         u_int32_t spi;
 111         struct secasvar *sav = NULL;
 112         size_t taillen;
 113         u_int16_t nxt;
 114         const struct esp_algorithm *algo;
 115         int ivlen;
 116         size_t hlen;
 117         size_t esplen;
 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                 key_sa_recordxfer(sav, m);
 382                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 383                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 384                         ipsecstat.in_nomem++;
 385                         goto bad;
 386                 }
 387
 388                 if (netisr_queue(NETISR_IP, m)) {
 389                         ipsecstat.in_inval++;
 390                         m = NULL;
 391                         goto bad;
 392                 }
 393
 394                 nxt = IPPROTO_DONE;
 395         } else {
 396                 /*
 397                  * strip off ESP header and IV.
 398                  * even in m_pulldown case, we need to strip off ESP so that
 399                  * we can always compute checksum for AH correctly.
 400                  */
 401                 size_t stripsiz;
 402
 403                 stripsiz = esplen + ivlen;
 404
 405                 ip = mtod(m, struct ip *);
 406                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 407                 m->m_data += stripsiz;
 408                 m->m_len -= stripsiz;
 409                 m->m_pkthdr.len -= stripsiz;
 410
 411                 ip = mtod(m, struct ip *);
 412 #ifdef IPLEN_FLIPPED
 413                 ip->ip_len = ip->ip_len - stripsiz;
 414 #else
 415                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 416 #endif
 417                 ip->ip_p = nxt;
 418
 419                 key_sa_recordxfer(sav, m);
 420                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 421                         ipsecstat.in_nomem++;
 422                         goto bad;
 423                 }
 424
 425                 if (nxt != IPPROTO_DONE) {
 426                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 427                             ipsec4_in_reject(m, NULL)) {
 428                                 ipsecstat.in_polvio++;
 429                                 goto bad;
 430                         }
 431                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 432                 } else
 433                         m_freem(m);
 434                 m = NULL;
 435         }
 436
 437         if (sav) {
 438                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 439                         printf("DP esp4_input call free SA:%p\n", sav));
 440                 key_freesav(sav);
 441         }
 442         ipsecstat.in_success++;
 443         return;
 444
 445 bad:
 446         if (sav) {
 447                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 448                         printf("DP esp4_input call free SA:%p\n", sav));
 449                 key_freesav(sav);
 450         }
 451         if (m)
 452                 m_freem(m);
 453         return;
 454 }
 455 #endif /* INET */
 456
 457 #ifdef INET6
 458 int
 459 esp6_input(mp, offp, proto)
 460         struct mbuf **mp;
 461         int *offp, proto;
 462 {
 463         struct mbuf *m = *mp;
 464         int off = *offp;
 465         struct ip6_hdr *ip6;
 466         struct esp *esp;
 467         struct esptail esptail;
 468         u_int32_t spi;
 469         struct secasvar *sav = NULL;
 470         size_t taillen;
 471         u_int16_t nxt;
 472         const struct esp_algorithm *algo;
 473         int ivlen;
 474         size_t esplen;
 475
 476         /* sanity check for alignment. */
 477         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 478                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 479                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 480                 ipsec6stat.in_inval++;
 481                 goto bad;
 482         }
 483
 484 #ifndef PULLDOWN_TEST
 485         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 486         esp = (struct esp *)(mtod(m, caddr_t) + off);
 487 #else
 488         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 489         if (esp == NULL) {
 490                 ipsec6stat.in_inval++;
 491                 return IPPROTO_DONE;
 492         }
 493 #endif
 494         ip6 = mtod(m, struct ip6_hdr *);
 495
 496         if (ntohs(ip6->ip6_plen) == 0) {
 497                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 498                     "ESP with IPv6 jumbogram is not supported.\n"));
 499                 ipsec6stat.in_inval++;
 500                 goto bad;
 501         }
 502
 503         /* find the sassoc. */
 504         spi = esp->esp_spi;
 505
 506         if ((sav = key_allocsa(AF_INET6,
 507                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 508                               IPPROTO_ESP, spi)) == 0) {
 509                 ipseclog((LOG_WARNING,
 510                     "IPv6 ESP input: no key association found for spi %u\n",
 511                     (u_int32_t)ntohl(spi)));
 512                 ipsec6stat.in_nosa++;
 513                 goto bad;
 514         }
 515         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 516                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 517         if (sav->state != SADB_SASTATE_MATURE
 518          && sav->state != SADB_SASTATE_DYING) {
 519                 ipseclog((LOG_DEBUG,
 520                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 521                     (u_int32_t)ntohl(spi)));
 522                 ipsec6stat.in_badspi++;
 523                 goto bad;
 524         }
 525         algo = esp_algorithm_lookup(sav->alg_enc);
 526         if (!algo) {
 527                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 528                     "unsupported encryption algorithm for spi %u\n",
 529                     (u_int32_t)ntohl(spi)));
 530                 ipsec6stat.in_badspi++;
 531                 goto bad;
 532         }
 533
 534         /* check if we have proper ivlen information */
 535         ivlen = sav->ivlen;
 536         if (ivlen < 0) {
 537                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 538                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 539                 ipsec6stat.in_badspi++;
 540                 goto bad;
 541         }
 542
 543         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 544          && (sav->alg_auth && sav->key_auth)))
 545                 goto noreplaycheck;
 546
 547         if (sav->alg_auth == SADB_X_AALG_NULL ||
 548             sav->alg_auth == SADB_AALG_NONE)
 549                 goto noreplaycheck;
 550
 551         /*
 552          * check for sequence number.
 553          */
 554         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 555                 ; /* okey */
 556         else {
 557                 ipsec6stat.in_espreplay++;
 558                 ipseclog((LOG_WARNING,
 559                     "replay packet in IPv6 ESP input: %s %s\n",
 560                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 561                 goto bad;
 562         }
 563
 564         /* check ICV */
 565     {
 566         u_char sum0[AH_MAXSUMSIZE];
 567         u_char sum[AH_MAXSUMSIZE];
 568         const struct ah_algorithm *sumalgo;
 569         size_t siz;
 570
 571         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 572         if (!sumalgo)
 573                 goto noreplaycheck;
 574         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 575         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 576                 ipsecstat.in_inval++;
 577                 goto bad;
 578         }
 579         if (AH_MAXSUMSIZE < siz) {
 580                 ipseclog((LOG_DEBUG,
 581                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 582                     (u_long)siz));
 583                 ipsec6stat.in_inval++;
 584                 goto bad;
 585         }
 586
 587         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 588
 589         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 590                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 591                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 592                 ipsec6stat.in_espauthfail++;
 593                 goto bad;
 594         }
 595
 596         if (bcmp(sum0, sum, siz) != 0) {
 597                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 598                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 599                 ipsec6stat.in_espauthfail++;
 600                 goto bad;
 601         }
 602
 603         /* strip off the authentication data */
 604         m_adj(m, -siz);
 605         ip6 = mtod(m, struct ip6_hdr *);
 606         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 607
 608         m->m_flags |= M_AUTHIPDGM;
 609         ipsec6stat.in_espauthsucc++;
 610     }
 611
 612         /*
 613          * update sequence number.
 614          */
 615         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 616                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 617                         ipsec6stat.in_espreplay++;
 618                         goto bad;
 619                 }
 620         }
 621
 622 noreplaycheck:
 623
 624         /* process main esp header. */
 625         if (sav->flags & SADB_X_EXT_OLD) {
 626                 /* RFC 1827 */
 627                 esplen = sizeof(struct esp);
 628         } else {
 629                 /* RFC 2406 */
 630                 if (sav->flags & SADB_X_EXT_DERIV)
 631                         esplen = sizeof(struct esp);
 632                 else
 633                         esplen = sizeof(struct newesp);
 634         }
 635
 636         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 637                 ipseclog((LOG_WARNING,
 638                     "IPv6 ESP input: packet too short\n"));
 639                 ipsec6stat.in_inval++;
 640                 goto bad;
 641         }
 642
 643 #ifndef PULLDOWN_TEST
 644         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 645 #else
 646         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 647         if (esp == NULL) {
 648                 ipsec6stat.in_inval++;
 649                 m = NULL;
 650                 goto bad;
 651         }
 652 #endif
 653         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 654
 655         /*
 656          * pre-compute and cache intermediate key
 657          */
 658         if (esp_schedule(algo, sav) != 0) {
 659                 ipsec6stat.in_inval++;
 660                 goto bad;
 661         }
 662
 663         /*
 664          * decrypt the packet.
 665          */
 666         if (!algo->decrypt)
 667                 panic("internal error: no decrypt function");
 668         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 669                 /* m is already freed */
 670                 m = NULL;
 671                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 672                     ipsec_logsastr(sav)));
 673                 ipsec6stat.in_inval++;
 674                 goto bad;
 675         }
 676         ipsec6stat.in_esphist[sav->alg_enc]++;
 677
 678         m->m_flags |= M_DECRYPTED;
 679
 680         /*
 681          * find the trailer of the ESP.
 682          */
 683         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 684              (caddr_t)&esptail);
 685         nxt = esptail.esp_nxt;
 686         taillen = esptail.esp_padlen + sizeof(esptail);
 687
 688         if (m->m_pkthdr.len < taillen
 689          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 690                 ipseclog((LOG_WARNING,
 691                     "bad pad length in IPv6 ESP input: %s %s\n",
 692                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 693                 ipsec6stat.in_inval++;
 694                 goto bad;
 695         }
 696
 697         /* strip off the trailing pad area. */
 698         m_adj(m, -taillen);
 699
 700         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 701
 702         /* was it transmitted over the IPsec tunnel SA? */
 703         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 704                 /*
 705                  * strip off all the headers that precedes ESP header.
 706                  *      IP6 xx ESP IP6' payload -> IP6' payload
 707                  *
 708                  * XXX more sanity checks
 709                  * XXX relationship with gif?
 710                  */
 711                 u_int32_t flowinfo;     /* net endian */
 712                 flowinfo = ip6->ip6_flow;
 713                 m_adj(m, off + esplen + ivlen);
 714                 if (m->m_len < sizeof(*ip6)) {
 715 #ifndef PULLDOWN_TEST
 716                         /*
 717                          * m_pullup is prohibited in KAME IPv6 input processing
 718                          * but there's no other way!
 719                          */
 720 #else
 721                         /* okay to pullup in m_pulldown style */
 722 #endif
 723                         m = m_pullup(m, sizeof(*ip6));
 724                         if (!m) {
 725                                 ipsec6stat.in_inval++;
 726                                 goto bad;
 727                         }
 728                 }
 729                 ip6 = mtod(m, struct ip6_hdr *);
 730                 /* ECN consideration. */
 731                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 732                 if (!key_checktunnelsanity(sav, AF_INET6,
 733                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 734                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 735                             "in IPv6 ESP input: %s %s\n",
 736                             ipsec6_logpacketstr(ip6, spi),
 737                             ipsec_logsastr(sav)));
 738                         ipsec6stat.in_inval++;
 739                         goto bad;
 740                 }
 741
 742                 key_sa_recordxfer(sav, m);
 743                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 744                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 745                         ipsec6stat.in_nomem++;
 746                         goto bad;
 747                 }
 748
 749                 if (netisr_queue(NETISR_IPV6, m)) {
 750                         ipsec6stat.in_inval++;
 751                         m = NULL;
 752                         goto bad;
 753                 }
 754
 755                 nxt = IPPROTO_DONE;
 756         } else {
 757                 /*
 758                  * strip off ESP header and IV.
 759                  * even in m_pulldown case, we need to strip off ESP so that
 760                  * we can always compute checksum for AH correctly.
 761                  */
 762                 size_t stripsiz;
 763                 char *prvnxtp;
 764
 765                 /*
 766                  * Set the next header field of the previous header correctly.
 767                  */
 768                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 769                 *prvnxtp = nxt;
 770
 771                 stripsiz = esplen + ivlen;
 772
 773                 ip6 = mtod(m, struct ip6_hdr *);
 774                 if (m->m_len >= stripsiz + off) {
 775                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 776                         m->m_data += stripsiz;
 777                         m->m_len -= stripsiz;
 778                         m->m_pkthdr.len -= stripsiz;
 779                 } else {
 780                         /*
 781                          * this comes with no copy if the boundary is on
 782                          * cluster
 783                          */
 784                         struct mbuf *n;
 785
 786                         n = m_split(m, off, M_DONTWAIT);
 787                         if (n == NULL) {
 788                                 /* m is retained by m_split */
 789                                 goto bad;
 790                         }
 791                         m_adj(n, stripsiz);
 792                         m_cat(m, n);
 793                         /* m_cat does not update m_pkthdr.len */
 794                         m->m_pkthdr.len += n->m_pkthdr.len;
 795                 }
 796
 797 #ifndef PULLDOWN_TEST
 798                 /*
 799                  * KAME requires that the packet to be contiguous on the
 800                  * mbuf.  We need to make that sure.
 801                  * this kind of code should be avoided.
 802                  * XXX other conditions to avoid running this part?
 803                  */
 804                 if (m->m_len != m->m_pkthdr.len) {
 805                         struct mbuf *n = NULL;
 806                         int maxlen;
 807
 808                         MGETHDR(n, M_DONTWAIT, MT_HEADER);
 809                         maxlen = MHLEN;
 810                         if (n)
 811                                 M_MOVE_PKTHDR(n, m);
 812                         if (n && n->m_pkthdr.len > maxlen) {
 813                                 MCLGET(n, M_DONTWAIT);
 814                                 maxlen = MCLBYTES;
 815                                 if ((n->m_flags & M_EXT) == 0) {
 816                                         m_free(n);
 817                                         n = NULL;
 818                                 }
 819                         }
 820                         if (!n) {
 821                                 printf("esp6_input: mbuf allocation failed\n");
 822                                 goto bad;
 823                         }
 824
 825                         if (n->m_pkthdr.len <= maxlen) {
 826                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 827                                 n->m_len = n->m_pkthdr.len;
 828                                 n->m_next = NULL;
 829                                 m_freem(m);
 830                         } else {
 831                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 832                                 n->m_len = maxlen;
 833                                 n->m_next = m;
 834                                 m_adj(m, maxlen);
 835                         }
 836                         m = n;
 837                 }
 838 #endif
 839
 840                 ip6 = mtod(m, struct ip6_hdr *);
 841                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 842
 843                 key_sa_recordxfer(sav, m);
 844                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 845                         ipsec6stat.in_nomem++;
 846                         goto bad;
 847                 }
 848         }
 849
 850         *offp = off;
 851         *mp = m;
 852
 853         if (sav) {
 854                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 855                         printf("DP esp6_input call free SA:%p\n", sav));
 856                 key_freesav(sav);
 857         }
 858         ipsec6stat.in_success++;
 859         return nxt;
 860
 861 bad:
 862         if (sav) {
 863                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 864                         printf("DP esp6_input call free SA:%p\n", sav));
 865                 key_freesav(sav);
 866         }
 867         if (m)
 868                 m_freem(m);
 869         return IPPROTO_DONE;
 870 }
 871
 872 void
 873 esp6_ctlinput(cmd, sa, d)
 874         int cmd;
 875         struct sockaddr *sa;
 876         void *d;
 877 {
 878         const struct newesp *espp;
 879         struct newesp esp;
 880         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 881         struct secasvar *sav;
 882         struct ip6_hdr *ip6;
 883         struct mbuf *m;
 884         int off;
 885         struct sockaddr_in6 *sa6_src, *sa6_dst;
 886
 887         if (sa->sa_family != AF_INET6 ||
 888             sa->sa_len != sizeof(struct sockaddr_in6))
 889                 return;
 890         if ((unsigned)cmd >= PRC_NCMDS)
 891                 return;
 892
 893         /* if the parameter is from icmp6, decode it. */
 894         if (d != NULL) {
 895                 ip6cp = (struct ip6ctlparam *)d;
 896                 m = ip6cp->ip6c_m;
 897                 ip6 = ip6cp->ip6c_ip6;
 898                 off = ip6cp->ip6c_off;
 899         } else {
 900                 m = NULL;
 901                 ip6 = NULL;
 902                 off = 0; /* fix warning */
 903         }
 904
 905         if (ip6) {
 906                 /*
 907                  * Notify the error to all possible sockets via pfctlinput2.
 908                  * Since the upper layer information (such as protocol type,
 909                  * source and destination ports) is embedded in the encrypted
 910                  * data and might have been cut, we can't directly call
 911                  * an upper layer ctlinput function. However, the pcbnotify
 912                  * function will consider source and destination addresses
 913                  * as well as the flow info value, and may be able to find
 914                  * some PCB that should be notified.
 915                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 916                  * no possibility of an infinite loop of function calls,
 917                  * because we don't pass the inner IPv6 header.
 918                  */
 919                 bzero(&ip6cp1, sizeof(ip6cp1));
 920                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 921                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 922
 923                 /*
 924                  * Then go to special cases that need ESP header information.
 925                  * XXX: We assume that when ip6 is non NULL,
 926                  * M and OFF are valid.
 927                  */
 928
 929                 /* check if we can safely examine src and dst ports */
 930                 if (m->m_pkthdr.len < off + sizeof(esp))
 931                         return;
 932
 933                 if (m->m_len < off + sizeof(esp)) {
 934                         /*
 935                          * this should be rare case,
 936                          * so we compromise on this copy...
 937                          */
 938                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 939                         espp = &esp;
 940                 } else
 941                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 942
 943                 if (cmd == PRC_MSGSIZE) {
 944                         int valid = 0;
 945
 946                         /*
 947                          * Check to see if we have a valid SA corresponding to
 948                          * the address in the ICMP message payload.
 949                          */
 950                         sa6_src = ip6cp->ip6c_src;
 951                         sa6_dst = (struct sockaddr_in6 *)sa;
 952                         sav = key_allocsa(AF_INET6,
 953                                           (caddr_t)&sa6_src->sin6_addr,
 954                                           (caddr_t)&sa6_dst->sin6_addr,
 955                                           IPPROTO_ESP, espp->esp_spi);
 956                         if (sav) {
 957                                 if (sav->state == SADB_SASTATE_MATURE ||
 958                                     sav->state == SADB_SASTATE_DYING)
 959                                         valid++;
 960                                 key_freesav(sav);
 961                         }
 962
 963                         /* XXX Further validation? */
 964
 965                         /*
 966                          * Depending on the value of "valid" and routing table
 967                          * size (mtudisc_{hi,lo}wat), we will:
 968                          * - recalcurate the new MTU and create the
 969                          *   corresponding routing entry, or
 970                          * - ignore the MTU change notification.
 971                          */
 972                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 973                 }
 974         } else {
 975                 /* we normally notify any pcb here */
 976         }
 977 }
 978 #endif /* INET6 */