sys/netinet6/esp_input.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: esp_input.c,v 1.25 2000/05/08 08:04:30 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 "opt_inet.h"
  38 #include "opt_inet6.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/domain.h>
  44 #include <sys/protosw.h>
  45 #include <sys/socket.h>
  46 #include <sys/errno.h>
  47 #include <sys/time.h>
  48 #include <sys/syslog.h>
  49
  50 #include <net/if.h>
  51 #include <net/route.h>
  52 #include <net/netisr.h>
  53 #include <machine/cpu.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58 #include <netinet/ip_var.h>
  59 #include <netinet/in_var.h>
  60 #include <netinet/ip_ecn.h>
  61 #ifdef INET6
  62 #include <netinet6/ip6_ecn.h>
  63 #endif
  64
  65 #ifdef INET6
  66 #include <netinet/ip6.h>
  67 #include <netinet6/ip6_var.h>
  68 #include <netinet/icmp6.h>
  69 #endif
  70
  71 #include <netinet6/ipsec.h>
  72 #ifdef INET6
  73 #include <netinet6/ipsec6.h>
  74 #endif
  75 #include <netinet6/ah.h>
  76 #ifdef INET6
  77 #include <netinet6/ah6.h>
  78 #endif
  79 #include <netinet6/esp.h>
  80 #ifdef INET6
  81 #include <netinet6/esp6.h>
  82 #endif
  83 #include <netkey/key.h>
  84 #include <netkey/keydb.h>
  85 #ifdef IPSEC_DEBUG
  86 #include <netkey/key_debug.h>
  87 #else
  88 #define KEYDEBUG(lev,arg)
  89 #endif
  90
  91 #include <machine/stdarg.h>
  92
  93 #include <net/net_osdep.h>
  94
  95 #define IPLEN_FLIPPED
  96
  97 #ifdef INET
  98 #include <netinet/ipprotosw.h>
  99 extern struct ipprotosw inetsw[];
 100
 101 #define ESPMAXLEN \
 102         (sizeof(struct esp) < sizeof(struct newesp) \
 103                 ? sizeof(struct newesp) : sizeof(struct esp))
 104
 105 void
 106 #if __STDC__
 107 esp4_input(struct mbuf *m, ...)
 108 #else
 109 esp4_input(m, va_alist)
 110         struct mbuf *m;
 111         va_dcl
 112 #endif
 113 {
 114         struct ip *ip;
 115         struct esp *esp;
 116         struct esptail esptail;
 117         u_int32_t spi;
 118         struct secasvar *sav = NULL;
 119         size_t taillen;
 120         u_int16_t nxt;
 121         struct esp_algorithm *algo;
 122         int ivlen;
 123         size_t hlen;
 124         size_t esplen;
 125         va_list ap;
 126         int off, proto;
 127
 128         va_start(ap, m);
 129         off = va_arg(ap, int);
 130         proto = va_arg(ap, int);
 131         va_end(ap);
 132
 133         /* sanity check for alignment. */
 134         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 135                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 136                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 137                 ipsecstat.in_inval++;
 138                 goto bad;
 139         }
 140
 141         if (m->m_len < off + ESPMAXLEN) {
 142                 m = m_pullup(m, off + ESPMAXLEN);
 143                 if (!m) {
 144                         ipseclog((LOG_DEBUG,
 145                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 146                         ipsecstat.in_inval++;
 147                         goto bad;
 148                 }
 149         }
 150
 151         ip = mtod(m, struct ip *);
 152         esp = (struct esp *)(((u_int8_t *)ip) + off);
 153 #ifdef _IP_VHL
 154         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 155 #else
 156         hlen = ip->ip_hl << 2;
 157 #endif
 158
 159         /* find the sassoc. */
 160         spi = esp->esp_spi;
 161
 162         if ((sav = key_allocsa(AF_INET,
 163                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 164                               IPPROTO_ESP, spi)) == 0) {
 165                 ipseclog((LOG_WARNING,
 166                     "IPv4 ESP input: no key association found for spi %u\n",
 167                     (u_int32_t)ntohl(spi)));
 168                 ipsecstat.in_nosa++;
 169                 goto bad;
 170         }
 171         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 172                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 173         if (sav->state != SADB_SASTATE_MATURE
 174          && sav->state != SADB_SASTATE_DYING) {
 175                 ipseclog((LOG_DEBUG,
 176                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 177                     (u_int32_t)ntohl(spi)));
 178                 ipsecstat.in_badspi++;
 179                 goto bad;
 180         }
 181         if (sav->alg_enc == SADB_EALG_NONE) {
 182                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 183                     "unspecified encryption algorithm for spi %u\n",
 184                     (u_int32_t)ntohl(spi)));
 185                 ipsecstat.in_badspi++;
 186                 goto bad;
 187         }
 188
 189         algo = &esp_algorithms[sav->alg_enc];   /*XXX*/
 190
 191         /* check if we have proper ivlen information */
 192         ivlen = sav->ivlen;
 193         if (ivlen < 0) {
 194                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 195                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 196                 ipsecstat.in_inval++;
 197                 goto bad;
 198         }
 199
 200         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 201          && (sav->alg_auth && sav->key_auth)))
 202                 goto noreplaycheck;
 203
 204         if (sav->alg_auth == SADB_AALG_NULL)
 205                 goto noreplaycheck;
 206
 207         /*
 208          * check for sequence number.
 209          */
 210         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 211                 ; /*okey*/
 212         else {
 213                 ipsecstat.in_espreplay++;
 214                 ipseclog((LOG_WARNING,
 215                     "replay packet in IPv4 ESP input: %s %s\n",
 216                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 217                 goto bad;
 218         }
 219
 220         /* check ICV */
 221     {
 222         u_char sum0[AH_MAXSUMSIZE];
 223         u_char sum[AH_MAXSUMSIZE];
 224         struct ah_algorithm *sumalgo;
 225         size_t siz;
 226
 227         sumalgo = &ah_algorithms[sav->alg_auth];
 228         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 229         if (AH_MAXSUMSIZE < siz) {
 230                 ipseclog((LOG_DEBUG,
 231                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 232                     (u_long)siz));
 233                 ipsecstat.in_inval++;
 234                 goto bad;
 235         }
 236
 237         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 238
 239         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 240                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 241                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 242                 ipsecstat.in_espauthfail++;
 243                 goto bad;
 244         }
 245
 246         if (bcmp(sum0, sum, siz) != 0) {
 247                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 248                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 249                 ipsecstat.in_espauthfail++;
 250                 goto bad;
 251         }
 252
 253         /* strip off the authentication data */
 254         m_adj(m, -siz);
 255         ip = mtod(m, struct ip *);
 256 #ifdef IPLEN_FLIPPED
 257         ip->ip_len = ip->ip_len - siz;
 258 #else
 259         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 260 #endif
 261         m->m_flags |= M_AUTHIPDGM;
 262         ipsecstat.in_espauthsucc++;
 263     }
 264
 265         /*
 266          * update sequence number.
 267          */
 268         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 269                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 270                         ipsecstat.in_espreplay++;
 271                         goto bad;
 272                 }
 273         }
 274
 275 noreplaycheck:
 276
 277         /* process main esp header. */
 278         if (sav->flags & SADB_X_EXT_OLD) {
 279                 /* RFC 1827 */
 280                 esplen = sizeof(struct esp);
 281         } else {
 282                 /* RFC 2406 */
 283                 if (sav->flags & SADB_X_EXT_DERIV)
 284                         esplen = sizeof(struct esp);
 285                 else
 286                         esplen = sizeof(struct newesp);
 287         }
 288
 289         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 290                 ipseclog((LOG_WARNING,
 291                     "IPv4 ESP input: packet too short\n"));
 292                 ipsecstat.in_inval++;
 293                 goto bad;
 294         }
 295
 296         if (m->m_len < off + esplen + ivlen) {
 297                 m = m_pullup(m, off + esplen + ivlen);
 298                 if (!m) {
 299                         ipseclog((LOG_DEBUG,
 300                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 301                         ipsecstat.in_inval++;
 302                         goto bad;
 303                 }
 304         }
 305
 306     {
 307         /*
 308          * decrypt the packet.
 309          */
 310         if (!algo->decrypt)
 311                 panic("internal error: no decrypt function");
 312         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 313                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s %s\n",
 314                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 315                 ipsecstat.in_inval++;
 316                 goto bad;
 317         }
 318         ipsecstat.in_esphist[sav->alg_enc]++;
 319
 320         m->m_flags |= M_DECRYPTED;
 321     }
 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(ip, 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
 391                 if (! IF_HANDOFF(&ipintrq, m, NULL)) {
 392                         ipsecstat.in_inval++;
 393                         m = NULL;
 394                         goto bad;
 395                 }
 396                 m = NULL;
 397                 schednetisr(NETISR_IP); /*can be skipped but to make sure*/
 398                 nxt = IPPROTO_DONE;
 399         } else {
 400                 /*
 401                  * strip off ESP header and IV.
 402                  * even in m_pulldown case, we need to strip off ESP so that
 403                  * we can always compute checksum for AH correctly.
 404                  */
 405                 size_t stripsiz;
 406
 407                 stripsiz = esplen + ivlen;
 408
 409                 ip = mtod(m, struct ip *);
 410                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 411                 m->m_data += stripsiz;
 412                 m->m_len -= stripsiz;
 413                 m->m_pkthdr.len -= stripsiz;
 414
 415                 ip = mtod(m, struct ip *);
 416 #ifdef IPLEN_FLIPPED
 417                 ip->ip_len = ip->ip_len - stripsiz;
 418 #else
 419                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 420 #endif
 421                 ip->ip_p = nxt;
 422
 423                 key_sa_recordxfer(sav, m);
 424
 425                 if (nxt != IPPROTO_DONE)
 426                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 427                 else
 428                         m_freem(m);
 429                 m = NULL;
 430         }
 431
 432         if (sav) {
 433                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 434                         printf("DP esp4_input call free SA:%p\n", sav));
 435                 key_freesav(sav);
 436         }
 437         ipsecstat.in_success++;
 438         return;
 439
 440 bad:
 441         if (sav) {
 442                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 443                         printf("DP esp4_input call free SA:%p\n", sav));
 444                 key_freesav(sav);
 445         }
 446         if (m)
 447                 m_freem(m);
 448         return;
 449 }
 450 #endif /* INET */
 451
 452 #ifdef INET6
 453 int
 454 esp6_input(mp, offp, proto)
 455         struct mbuf **mp;
 456         int *offp, proto;
 457 {
 458         struct mbuf *m = *mp;
 459         int off = *offp;
 460         struct ip6_hdr *ip6;
 461         struct esp *esp;
 462         struct esptail esptail;
 463         u_int32_t spi;
 464         struct secasvar *sav = NULL;
 465         size_t taillen;
 466         u_int16_t nxt;
 467         struct esp_algorithm *algo;
 468         int ivlen;
 469         size_t esplen;
 470         int s;
 471
 472         /* sanity check for alignment. */
 473         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 474                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 475                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 476                 ipsec6stat.in_inval++;
 477                 goto bad;
 478         }
 479
 480 #ifndef PULLDOWN_TEST
 481         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 482         esp = (struct esp *)(mtod(m, caddr_t) + off);
 483 #else
 484         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 485         if (esp == NULL) {
 486                 ipsec6stat.in_inval++;
 487                 return IPPROTO_DONE;
 488         }
 489 #endif
 490         ip6 = mtod(m, struct ip6_hdr *);
 491
 492         if (ntohs(ip6->ip6_plen) == 0) {
 493                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 494                     "ESP with IPv6 jumbogram is not supported.\n"));
 495                 ipsec6stat.in_inval++;
 496                 goto bad;
 497         }
 498
 499         /* find the sassoc. */
 500         spi = esp->esp_spi;
 501
 502         if ((sav = key_allocsa(AF_INET6,
 503                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 504                               IPPROTO_ESP, spi)) == 0) {
 505                 ipseclog((LOG_WARNING,
 506                     "IPv6 ESP input: no key association found for spi %u\n",
 507                     (u_int32_t)ntohl(spi)));
 508                 ipsec6stat.in_nosa++;
 509                 goto bad;
 510         }
 511         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 512                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 513         if (sav->state != SADB_SASTATE_MATURE
 514          && sav->state != SADB_SASTATE_DYING) {
 515                 ipseclog((LOG_DEBUG,
 516                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 517                     (u_int32_t)ntohl(spi)));
 518                 ipsec6stat.in_badspi++;
 519                 goto bad;
 520         }
 521         if (sav->alg_enc == SADB_EALG_NONE) {
 522                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 523                     "unspecified encryption algorithm for spi %u\n",
 524                     (u_int32_t)ntohl(spi)));
 525                 ipsec6stat.in_badspi++;
 526                 goto bad;
 527         }
 528
 529         algo = &esp_algorithms[sav->alg_enc];   /*XXX*/
 530
 531         /* check if we have proper ivlen information */
 532         ivlen = sav->ivlen;
 533         if (ivlen < 0) {
 534                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 535                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 536                 ipsec6stat.in_badspi++;
 537                 goto bad;
 538         }
 539
 540         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 541          && (sav->alg_auth && sav->key_auth)))
 542                 goto noreplaycheck;
 543
 544         if (sav->alg_auth == SADB_AALG_NULL)
 545                 goto noreplaycheck;
 546
 547         /*
 548          * check for sequence number.
 549          */
 550         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 551                 ; /*okey*/
 552         else {
 553                 ipsec6stat.in_espreplay++;
 554                 ipseclog((LOG_WARNING,
 555                     "replay packet in IPv6 ESP input: %s %s\n",
 556                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 557                 goto bad;
 558         }
 559
 560         /* check ICV */
 561     {
 562         u_char sum0[AH_MAXSUMSIZE];
 563         u_char sum[AH_MAXSUMSIZE];
 564         struct ah_algorithm *sumalgo;
 565         size_t siz;
 566
 567         sumalgo = &ah_algorithms[sav->alg_auth];
 568         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 569         if (AH_MAXSUMSIZE < siz) {
 570                 ipseclog((LOG_DEBUG,
 571                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 572                     (u_long)siz));
 573                 ipsec6stat.in_inval++;
 574                 goto bad;
 575         }
 576
 577         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 578
 579         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 580                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 581                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 582                 ipsec6stat.in_espauthfail++;
 583                 goto bad;
 584         }
 585
 586         if (bcmp(sum0, sum, siz) != 0) {
 587                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 588                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 589                 ipsec6stat.in_espauthfail++;
 590                 goto bad;
 591         }
 592
 593         /* strip off the authentication data */
 594         m_adj(m, -siz);
 595         ip6 = mtod(m, struct ip6_hdr *);
 596         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 597
 598         m->m_flags |= M_AUTHIPDGM;
 599         ipsec6stat.in_espauthsucc++;
 600     }
 601
 602         /*
 603          * update sequence number.
 604          */
 605         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 606                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 607                         ipsec6stat.in_espreplay++;
 608                         goto bad;
 609                 }
 610         }
 611
 612 noreplaycheck:
 613
 614         /* process main esp header. */
 615         if (sav->flags & SADB_X_EXT_OLD) {
 616                 /* RFC 1827 */
 617                 esplen = sizeof(struct esp);
 618         } else {
 619                 /* RFC 2406 */
 620                 if (sav->flags & SADB_X_EXT_DERIV)
 621                         esplen = sizeof(struct esp);
 622                 else
 623                         esplen = sizeof(struct newesp);
 624         }
 625
 626         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 627                 ipseclog((LOG_WARNING,
 628                     "IPv6 ESP input: packet too short\n"));
 629                 ipsec6stat.in_inval++;
 630                 goto bad;
 631         }
 632
 633 #ifndef PULLDOWN_TEST
 634         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /*XXX*/
 635 #else
 636         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 637         if (esp == NULL) {
 638                 ipsec6stat.in_inval++;
 639                 m = NULL;
 640                 goto bad;
 641         }
 642 #endif
 643         ip6 = mtod(m, struct ip6_hdr *);        /*set it again just in case*/
 644
 645         /*
 646          * decrypt the packet.
 647          */
 648         if (!algo->decrypt)
 649                 panic("internal error: no decrypt function");
 650         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 651                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s %s\n",
 652                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 653                 ipsec6stat.in_inval++;
 654                 goto bad;
 655         }
 656         ipsec6stat.in_esphist[sav->alg_enc]++;
 657
 658         m->m_flags |= M_DECRYPTED;
 659
 660         /*
 661          * find the trailer of the ESP.
 662          */
 663         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 664              (caddr_t)&esptail);
 665         nxt = esptail.esp_nxt;
 666         taillen = esptail.esp_padlen + sizeof(esptail);
 667
 668         if (m->m_pkthdr.len < taillen
 669          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /*?*/
 670                 ipseclog((LOG_WARNING,
 671                     "bad pad length in IPv6 ESP input: %s %s\n",
 672                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 673                 ipsec6stat.in_inval++;
 674                 goto bad;
 675         }
 676
 677         /* strip off the trailing pad area. */
 678         m_adj(m, -taillen);
 679
 680         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 681
 682         /* was it transmitted over the IPsec tunnel SA? */
 683         if (ipsec6_tunnel_validate(ip6, nxt, sav)) {
 684                 /*
 685                  * strip off all the headers that precedes ESP header.
 686                  *      IP6 xx ESP IP6' payload -> IP6' payload
 687                  *
 688                  * XXX more sanity checks
 689                  * XXX relationship with gif?
 690                  */
 691                 u_int32_t flowinfo;     /*net endian*/
 692                 flowinfo = ip6->ip6_flow;
 693                 m_adj(m, off + esplen + ivlen);
 694                 if (m->m_len < sizeof(*ip6)) {
 695 #ifndef PULLDOWN_TEST
 696                         /*
 697                          * m_pullup is prohibited in KAME IPv6 input processing
 698                          * but there's no other way!
 699                          */
 700 #else
 701                         /* okay to pullup in m_pulldown style */
 702 #endif
 703                         m = m_pullup(m, sizeof(*ip6));
 704                         if (!m) {
 705                                 ipsec6stat.in_inval++;
 706                                 goto bad;
 707                         }
 708                 }
 709                 ip6 = mtod(m, struct ip6_hdr *);
 710                 /* ECN consideration. */
 711                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 712                 if (!key_checktunnelsanity(sav, AF_INET6,
 713                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 714                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 715                             "in IPv6 ESP input: %s %s\n",
 716                             ipsec6_logpacketstr(ip6, spi),
 717                             ipsec_logsastr(sav)));
 718                         ipsec6stat.in_inval++;
 719                         goto bad;
 720                 }
 721
 722 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 723                 /* drop it if it does not match the default policy */
 724                 if (ipsec6_in_reject(m, NULL)) {
 725                         ipsec6stat.in_polvio++;
 726                         goto bad;
 727                 }
 728 #endif
 729
 730                 key_sa_recordxfer(sav, m);
 731
 732                 if (! IF_HANDOFF(&ip6intrq, m, NULL)) {
 733                         ipsec6stat.in_inval++;
 734                         m = NULL;
 735                         goto bad;
 736                 }
 737                 m = NULL;
 738                 schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
 739                 nxt = IPPROTO_DONE;
 740         } else {
 741                 /*
 742                  * strip off ESP header and IV.
 743                  * even in m_pulldown case, we need to strip off ESP so that
 744                  * we can always compute checksum for AH correctly.
 745                  */
 746                 size_t stripsiz;
 747                 char *prvnxtp;
 748
 749                 /*
 750                  * Set the next header field of the previous header correctly.
 751                  */
 752                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 753                 *prvnxtp = nxt;
 754
 755                 stripsiz = esplen + ivlen;
 756
 757                 ip6 = mtod(m, struct ip6_hdr *);
 758                 if (m->m_len >= stripsiz + off) {
 759                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 760                         m->m_data += stripsiz;
 761                         m->m_len -= stripsiz;
 762                         m->m_pkthdr.len -= stripsiz;
 763                 } else {
 764                         /*
 765                          * this comes with no copy if the boundary is on
 766                          * cluster
 767                          */
 768                         struct mbuf *n;
 769
 770                         n = m_split(m, off, M_DONTWAIT);
 771                         if (n == NULL) {
 772                                 /* m is retained by m_split */
 773                                 goto bad;
 774                         }
 775                         m_adj(n, stripsiz);
 776                         m_cat(m, n);
 777                         /* m_cat does not update m_pkthdr.len */
 778                         m->m_pkthdr.len += n->m_pkthdr.len;
 779                 }
 780
 781                 ip6 = mtod(m, struct ip6_hdr *);
 782                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 783
 784                 key_sa_recordxfer(sav, m);
 785         }
 786
 787         *offp = off;
 788         *mp = m;
 789
 790         if (sav) {
 791                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 792                         printf("DP esp6_input call free SA:%p\n", sav));
 793                 key_freesav(sav);
 794         }
 795         ipsec6stat.in_success++;
 796         return nxt;
 797
 798 bad:
 799         if (sav) {
 800                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 801                         printf("DP esp6_input call free SA:%p\n", sav));
 802                 key_freesav(sav);
 803         }
 804         if (m)
 805                 m_freem(m);
 806         return IPPROTO_DONE;
 807 }
 808 #endif /* INET6 */