sys/netinet6/esp_input.c

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