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 1.8 2004/10/20 05:00:36 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, ...)
 106 {
 107         int off, proto;
 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         __va_list ap;
 120
 121         __va_start(ap, m);
 122         off = __va_arg(ap, int);
 123         proto = __va_arg(ap, int);
 124         __va_end(ap);
 125
 126         /* sanity check for alignment. */
 127         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 128                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 129                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 130                 ipsecstat.in_inval++;
 131                 goto bad;
 132         }
 133
 134         if (m->m_len < off + ESPMAXLEN) {
 135                 m = m_pullup(m, off + ESPMAXLEN);
 136                 if (!m) {
 137                         ipseclog((LOG_DEBUG,
 138                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 139                         ipsecstat.in_inval++;
 140                         goto bad;
 141                 }
 142         }
 143
 144         ip = mtod(m, struct ip *);
 145         esp = (struct esp *)(((u_int8_t *)ip) + off);
 146 #ifdef _IP_VHL
 147         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 148 #else
 149         hlen = ip->ip_hl << 2;
 150 #endif
 151
 152         /* find the sassoc. */
 153         spi = esp->esp_spi;
 154
 155         if ((sav = key_allocsa(AF_INET,
 156                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 157                               IPPROTO_ESP, spi)) == 0) {
 158                 ipseclog((LOG_WARNING,
 159                     "IPv4 ESP input: no key association found for spi %u\n",
 160                     (u_int32_t)ntohl(spi)));
 161                 ipsecstat.in_nosa++;
 162                 goto bad;
 163         }
 164         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 165                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 166         if (sav->state != SADB_SASTATE_MATURE
 167          && sav->state != SADB_SASTATE_DYING) {
 168                 ipseclog((LOG_DEBUG,
 169                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 170                     (u_int32_t)ntohl(spi)));
 171                 ipsecstat.in_badspi++;
 172                 goto bad;
 173         }
 174         algo = esp_algorithm_lookup(sav->alg_enc);
 175         if (!algo) {
 176                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 177                     "unsupported encryption algorithm for spi %u\n",
 178                     (u_int32_t)ntohl(spi)));
 179                 ipsecstat.in_badspi++;
 180                 goto bad;
 181         }
 182
 183         /* check if we have proper ivlen information */
 184         ivlen = sav->ivlen;
 185         if (ivlen < 0) {
 186                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 187                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 188                 ipsecstat.in_inval++;
 189                 goto bad;
 190         }
 191
 192         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 193          && (sav->alg_auth && sav->key_auth)))
 194                 goto noreplaycheck;
 195
 196         if (sav->alg_auth == SADB_X_AALG_NULL ||
 197             sav->alg_auth == SADB_AALG_NONE)
 198                 goto noreplaycheck;
 199
 200         /*
 201          * check for sequence number.
 202          */
 203         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 204                 ; /* okey */
 205         else {
 206                 ipsecstat.in_espreplay++;
 207                 ipseclog((LOG_WARNING,
 208                     "replay packet in IPv4 ESP input: %s %s\n",
 209                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 210                 goto bad;
 211         }
 212
 213         /* check ICV */
 214     {
 215         u_char sum0[AH_MAXSUMSIZE];
 216         u_char sum[AH_MAXSUMSIZE];
 217         const struct ah_algorithm *sumalgo;
 218         size_t siz;
 219
 220         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 221         if (!sumalgo)
 222                 goto noreplaycheck;
 223         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 224         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 225                 ipsecstat.in_inval++;
 226                 goto bad;
 227         }
 228         if (AH_MAXSUMSIZE < siz) {
 229                 ipseclog((LOG_DEBUG,
 230                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 231                     (u_long)siz));
 232                 ipsecstat.in_inval++;
 233                 goto bad;
 234         }
 235
 236         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 237
 238         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 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         if (bcmp(sum0, sum, siz) != 0) {
 246                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 247                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 248                 ipsecstat.in_espauthfail++;
 249                 goto bad;
 250         }
 251
 252         /* strip off the authentication data */
 253         m_adj(m, -siz);
 254         ip = mtod(m, struct ip *);
 255 #ifdef IPLEN_FLIPPED
 256         ip->ip_len = ip->ip_len - siz;
 257 #else
 258         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 259 #endif
 260         m->m_flags |= M_AUTHIPDGM;
 261         ipsecstat.in_espauthsucc++;
 262     }
 263
 264         /*
 265          * update sequence number.
 266          */
 267         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 268                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 269                         ipsecstat.in_espreplay++;
 270                         goto bad;
 271                 }
 272         }
 273
 274 noreplaycheck:
 275
 276         /* process main esp header. */
 277         if (sav->flags & SADB_X_EXT_OLD) {
 278                 /* RFC 1827 */
 279                 esplen = sizeof(struct esp);
 280         } else {
 281                 /* RFC 2406 */
 282                 if (sav->flags & SADB_X_EXT_DERIV)
 283                         esplen = sizeof(struct esp);
 284                 else
 285                         esplen = sizeof(struct newesp);
 286         }
 287
 288         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 289                 ipseclog((LOG_WARNING,
 290                     "IPv4 ESP input: packet too short\n"));
 291                 ipsecstat.in_inval++;
 292                 goto bad;
 293         }
 294
 295         if (m->m_len < off + esplen + ivlen) {
 296                 m = m_pullup(m, off + esplen + ivlen);
 297                 if (!m) {
 298                         ipseclog((LOG_DEBUG,
 299                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 300                         ipsecstat.in_inval++;
 301                         goto bad;
 302                 }
 303         }
 304
 305         /*
 306          * pre-compute and cache intermediate key
 307          */
 308         if (esp_schedule(algo, sav) != 0) {
 309                 ipsecstat.in_inval++;
 310                 goto bad;
 311         }
 312
 313         /*
 314          * decrypt the packet.
 315          */
 316         if (!algo->decrypt)
 317                 panic("internal error: no decrypt function");
 318         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 319                 /* m is already freed */
 320                 m = NULL;
 321                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 322                     ipsec_logsastr(sav)));
 323                 ipsecstat.in_inval++;
 324                 goto bad;
 325         }
 326         ipsecstat.in_esphist[sav->alg_enc]++;
 327
 328         m->m_flags |= M_DECRYPTED;
 329
 330         /*
 331          * find the trailer of the ESP.
 332          */
 333         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 334              (caddr_t)&esptail);
 335         nxt = esptail.esp_nxt;
 336         taillen = esptail.esp_padlen + sizeof(esptail);
 337
 338         if (m->m_pkthdr.len < taillen
 339          || m->m_pkthdr.len - taillen < hlen) { /* ? */
 340                 ipseclog((LOG_WARNING,
 341                     "bad pad length in IPv4 ESP input: %s %s\n",
 342                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 343                 ipsecstat.in_inval++;
 344                 goto bad;
 345         }
 346
 347         /* strip off the trailing pad area. */
 348         m_adj(m, -taillen);
 349
 350 #ifdef IPLEN_FLIPPED
 351         ip->ip_len = ip->ip_len - taillen;
 352 #else
 353         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 354 #endif
 355
 356         /* was it transmitted over the IPsec tunnel SA? */
 357         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 358                 /*
 359                  * strip off all the headers that precedes ESP header.
 360                  *      IP4 xx ESP IP4' payload -> IP4' payload
 361                  *
 362                  * XXX more sanity checks
 363                  * XXX relationship with gif?
 364                  */
 365                 u_int8_t tos;
 366
 367                 tos = ip->ip_tos;
 368                 m_adj(m, off + esplen + ivlen);
 369                 if (m->m_len < sizeof(*ip)) {
 370                         m = m_pullup(m, sizeof(*ip));
 371                         if (!m) {
 372                                 ipsecstat.in_inval++;
 373                                 goto bad;
 374                         }
 375                 }
 376                 ip = mtod(m, struct ip *);
 377                 /* ECN consideration. */
 378                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 379                 if (!key_checktunnelsanity(sav, AF_INET,
 380                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 381                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 382                             "in IPv4 ESP input: %s %s\n",
 383                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 384                         ipsecstat.in_inval++;
 385                         goto bad;
 386                 }
 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 (netisr_queue(NETISR_IP, m)) {
 396                         ipsecstat.in_inval++;
 397                         m = NULL;
 398                         goto bad;
 399                 }
 400
 401                 nxt = IPPROTO_DONE;
 402         } else {
 403                 /*
 404                  * strip off ESP header and IV.
 405                  * even in m_pulldown case, we need to strip off ESP so that
 406                  * we can always compute checksum for AH correctly.
 407                  */
 408                 size_t stripsiz;
 409
 410                 stripsiz = esplen + ivlen;
 411
 412                 ip = mtod(m, struct ip *);
 413                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 414                 m->m_data += stripsiz;
 415                 m->m_len -= stripsiz;
 416                 m->m_pkthdr.len -= stripsiz;
 417
 418                 ip = mtod(m, struct ip *);
 419 #ifdef IPLEN_FLIPPED
 420                 ip->ip_len = ip->ip_len - stripsiz;
 421 #else
 422                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 423 #endif
 424                 ip->ip_p = nxt;
 425
 426                 key_sa_recordxfer(sav, m);
 427                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 428                         ipsecstat.in_nomem++;
 429                         goto bad;
 430                 }
 431
 432                 if (nxt != IPPROTO_DONE) {
 433                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 434                             ipsec4_in_reject(m, NULL)) {
 435                                 ipsecstat.in_polvio++;
 436                                 goto bad;
 437                         }
 438                         if (!ip_lengthcheck(&m)) {
 439                                 m = NULL;       /* freed in ip_lengthcheck() */
 440                                 goto bad;
 441                         }
 442                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 443                 } else
 444                         m_freem(m);
 445                 m = NULL;
 446         }
 447
 448         if (sav) {
 449                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 450                         printf("DP esp4_input call free SA:%p\n", sav));
 451                 key_freesav(sav);
 452         }
 453         ipsecstat.in_success++;
 454         return;
 455
 456 bad:
 457         if (sav) {
 458                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 459                         printf("DP esp4_input call free SA:%p\n", sav));
 460                 key_freesav(sav);
 461         }
 462         if (m)
 463                 m_freem(m);
 464         return;
 465 }
 466 #endif /* INET */
 467
 468 #ifdef INET6
 469 int
 470 esp6_input(mp, offp, proto)
 471         struct mbuf **mp;
 472         int *offp, proto;
 473 {
 474         struct mbuf *m = *mp;
 475         int off = *offp;
 476         struct ip6_hdr *ip6;
 477         struct esp *esp;
 478         struct esptail esptail;
 479         u_int32_t spi;
 480         struct secasvar *sav = NULL;
 481         size_t taillen;
 482         u_int16_t nxt;
 483         const struct esp_algorithm *algo;
 484         int ivlen;
 485         size_t esplen;
 486
 487         /* sanity check for alignment. */
 488         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 489                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 490                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 491                 ipsec6stat.in_inval++;
 492                 goto bad;
 493         }
 494
 495 #ifndef PULLDOWN_TEST
 496         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 497         esp = (struct esp *)(mtod(m, caddr_t) + off);
 498 #else
 499         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 500         if (esp == NULL) {
 501                 ipsec6stat.in_inval++;
 502                 return IPPROTO_DONE;
 503         }
 504 #endif
 505         ip6 = mtod(m, struct ip6_hdr *);
 506
 507         if (ntohs(ip6->ip6_plen) == 0) {
 508                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 509                     "ESP with IPv6 jumbogram is not supported.\n"));
 510                 ipsec6stat.in_inval++;
 511                 goto bad;
 512         }
 513
 514         /* find the sassoc. */
 515         spi = esp->esp_spi;
 516
 517         if ((sav = key_allocsa(AF_INET6,
 518                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 519                               IPPROTO_ESP, spi)) == 0) {
 520                 ipseclog((LOG_WARNING,
 521                     "IPv6 ESP input: no key association found for spi %u\n",
 522                     (u_int32_t)ntohl(spi)));
 523                 ipsec6stat.in_nosa++;
 524                 goto bad;
 525         }
 526         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 527                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 528         if (sav->state != SADB_SASTATE_MATURE
 529          && sav->state != SADB_SASTATE_DYING) {
 530                 ipseclog((LOG_DEBUG,
 531                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 532                     (u_int32_t)ntohl(spi)));
 533                 ipsec6stat.in_badspi++;
 534                 goto bad;
 535         }
 536         algo = esp_algorithm_lookup(sav->alg_enc);
 537         if (!algo) {
 538                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 539                     "unsupported encryption algorithm for spi %u\n",
 540                     (u_int32_t)ntohl(spi)));
 541                 ipsec6stat.in_badspi++;
 542                 goto bad;
 543         }
 544
 545         /* check if we have proper ivlen information */
 546         ivlen = sav->ivlen;
 547         if (ivlen < 0) {
 548                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 549                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 550                 ipsec6stat.in_badspi++;
 551                 goto bad;
 552         }
 553
 554         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 555          && (sav->alg_auth && sav->key_auth)))
 556                 goto noreplaycheck;
 557
 558         if (sav->alg_auth == SADB_X_AALG_NULL ||
 559             sav->alg_auth == SADB_AALG_NONE)
 560                 goto noreplaycheck;
 561
 562         /*
 563          * check for sequence number.
 564          */
 565         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 566                 ; /* okey */
 567         else {
 568                 ipsec6stat.in_espreplay++;
 569                 ipseclog((LOG_WARNING,
 570                     "replay packet in IPv6 ESP input: %s %s\n",
 571                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 572                 goto bad;
 573         }
 574
 575         /* check ICV */
 576     {
 577         u_char sum0[AH_MAXSUMSIZE];
 578         u_char sum[AH_MAXSUMSIZE];
 579         const struct ah_algorithm *sumalgo;
 580         size_t siz;
 581
 582         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 583         if (!sumalgo)
 584                 goto noreplaycheck;
 585         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 586         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 587                 ipsecstat.in_inval++;
 588                 goto bad;
 589         }
 590         if (AH_MAXSUMSIZE < siz) {
 591                 ipseclog((LOG_DEBUG,
 592                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 593                     (u_long)siz));
 594                 ipsec6stat.in_inval++;
 595                 goto bad;
 596         }
 597
 598         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 599
 600         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 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         if (bcmp(sum0, sum, siz) != 0) {
 608                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 609                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 610                 ipsec6stat.in_espauthfail++;
 611                 goto bad;
 612         }
 613
 614         /* strip off the authentication data */
 615         m_adj(m, -siz);
 616         ip6 = mtod(m, struct ip6_hdr *);
 617         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 618
 619         m->m_flags |= M_AUTHIPDGM;
 620         ipsec6stat.in_espauthsucc++;
 621     }
 622
 623         /*
 624          * update sequence number.
 625          */
 626         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 627                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 628                         ipsec6stat.in_espreplay++;
 629                         goto bad;
 630                 }
 631         }
 632
 633 noreplaycheck:
 634
 635         /* process main esp header. */
 636         if (sav->flags & SADB_X_EXT_OLD) {
 637                 /* RFC 1827 */
 638                 esplen = sizeof(struct esp);
 639         } else {
 640                 /* RFC 2406 */
 641                 if (sav->flags & SADB_X_EXT_DERIV)
 642                         esplen = sizeof(struct esp);
 643                 else
 644                         esplen = sizeof(struct newesp);
 645         }
 646
 647         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 648                 ipseclog((LOG_WARNING,
 649                     "IPv6 ESP input: packet too short\n"));
 650                 ipsec6stat.in_inval++;
 651                 goto bad;
 652         }
 653
 654 #ifndef PULLDOWN_TEST
 655         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 656 #else
 657         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 658         if (esp == NULL) {
 659                 ipsec6stat.in_inval++;
 660                 m = NULL;
 661                 goto bad;
 662         }
 663 #endif
 664         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 665
 666         /*
 667          * pre-compute and cache intermediate key
 668          */
 669         if (esp_schedule(algo, sav) != 0) {
 670                 ipsec6stat.in_inval++;
 671                 goto bad;
 672         }
 673
 674         /*
 675          * decrypt the packet.
 676          */
 677         if (!algo->decrypt)
 678                 panic("internal error: no decrypt function");
 679         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 680                 /* m is already freed */
 681                 m = NULL;
 682                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 683                     ipsec_logsastr(sav)));
 684                 ipsec6stat.in_inval++;
 685                 goto bad;
 686         }
 687         ipsec6stat.in_esphist[sav->alg_enc]++;
 688
 689         m->m_flags |= M_DECRYPTED;
 690
 691         /*
 692          * find the trailer of the ESP.
 693          */
 694         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 695              (caddr_t)&esptail);
 696         nxt = esptail.esp_nxt;
 697         taillen = esptail.esp_padlen + sizeof(esptail);
 698
 699         if (m->m_pkthdr.len < taillen
 700          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 701                 ipseclog((LOG_WARNING,
 702                     "bad pad length in IPv6 ESP input: %s %s\n",
 703                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 704                 ipsec6stat.in_inval++;
 705                 goto bad;
 706         }
 707
 708         /* strip off the trailing pad area. */
 709         m_adj(m, -taillen);
 710
 711         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 712
 713         /* was it transmitted over the IPsec tunnel SA? */
 714         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 715                 /*
 716                  * strip off all the headers that precedes ESP header.
 717                  *      IP6 xx ESP IP6' payload -> IP6' payload
 718                  *
 719                  * XXX more sanity checks
 720                  * XXX relationship with gif?
 721                  */
 722                 u_int32_t flowinfo;     /* net endian */
 723                 flowinfo = ip6->ip6_flow;
 724                 m_adj(m, off + esplen + ivlen);
 725                 if (m->m_len < sizeof(*ip6)) {
 726 #ifndef PULLDOWN_TEST
 727                         /*
 728                          * m_pullup is prohibited in KAME IPv6 input processing
 729                          * but there's no other way!
 730                          */
 731 #else
 732                         /* okay to pullup in m_pulldown style */
 733 #endif
 734                         m = m_pullup(m, sizeof(*ip6));
 735                         if (!m) {
 736                                 ipsec6stat.in_inval++;
 737                                 goto bad;
 738                         }
 739                 }
 740                 ip6 = mtod(m, struct ip6_hdr *);
 741                 /* ECN consideration. */
 742                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 743                 if (!key_checktunnelsanity(sav, AF_INET6,
 744                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 745                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 746                             "in IPv6 ESP input: %s %s\n",
 747                             ipsec6_logpacketstr(ip6, spi),
 748                             ipsec_logsastr(sav)));
 749                         ipsec6stat.in_inval++;
 750                         goto bad;
 751                 }
 752
 753                 key_sa_recordxfer(sav, m);
 754                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 755                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 756                         ipsec6stat.in_nomem++;
 757                         goto bad;
 758                 }
 759
 760                 if (netisr_queue(NETISR_IPV6, m)) {
 761                         ipsec6stat.in_inval++;
 762                         m = NULL;
 763                         goto bad;
 764                 }
 765
 766                 nxt = IPPROTO_DONE;
 767         } else {
 768                 /*
 769                  * strip off ESP header and IV.
 770                  * even in m_pulldown case, we need to strip off ESP so that
 771                  * we can always compute checksum for AH correctly.
 772                  */
 773                 size_t stripsiz;
 774                 char *prvnxtp;
 775
 776                 /*
 777                  * Set the next header field of the previous header correctly.
 778                  */
 779                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 780                 *prvnxtp = nxt;
 781
 782                 stripsiz = esplen + ivlen;
 783
 784                 ip6 = mtod(m, struct ip6_hdr *);
 785                 if (m->m_len >= stripsiz + off) {
 786                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 787                         m->m_data += stripsiz;
 788                         m->m_len -= stripsiz;
 789                         m->m_pkthdr.len -= stripsiz;
 790                 } else {
 791                         /*
 792                          * this comes with no copy if the boundary is on
 793                          * cluster
 794                          */
 795                         struct mbuf *n;
 796
 797                         n = m_split(m, off, MB_DONTWAIT);
 798                         if (n == NULL) {
 799                                 /* m is retained by m_split */
 800                                 goto bad;
 801                         }
 802                         m_adj(n, stripsiz);
 803                         m_cat(m, n);
 804                         /* m_cat does not update m_pkthdr.len */
 805                         m->m_pkthdr.len += n->m_pkthdr.len;
 806                 }
 807
 808 #ifndef PULLDOWN_TEST
 809                 /*
 810                  * KAME requires that the packet to be contiguous on the
 811                  * mbuf.  We need to make that sure.
 812                  * this kind of code should be avoided.
 813                  * XXX other conditions to avoid running this part?
 814                  */
 815                 if (m->m_len != m->m_pkthdr.len) {
 816                         struct mbuf *n = NULL;
 817                         int maxlen;
 818
 819                         MGETHDR(n, MB_DONTWAIT, MT_HEADER);
 820                         maxlen = MHLEN;
 821                         if (n)
 822                                 M_MOVE_PKTHDR(n, m);
 823                         if (n && n->m_pkthdr.len > maxlen) {
 824                                 MCLGET(n, MB_DONTWAIT);
 825                                 maxlen = MCLBYTES;
 826                                 if ((n->m_flags & M_EXT) == 0) {
 827                                         m_free(n);
 828                                         n = NULL;
 829                                 }
 830                         }
 831                         if (!n) {
 832                                 printf("esp6_input: mbuf allocation failed\n");
 833                                 goto bad;
 834                         }
 835
 836                         if (n->m_pkthdr.len <= maxlen) {
 837                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 838                                 n->m_len = n->m_pkthdr.len;
 839                                 n->m_next = NULL;
 840                                 m_freem(m);
 841                         } else {
 842                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 843                                 n->m_len = maxlen;
 844                                 n->m_next = m;
 845                                 m_adj(m, maxlen);
 846                         }
 847                         m = n;
 848                 }
 849 #endif
 850
 851                 ip6 = mtod(m, struct ip6_hdr *);
 852                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 853
 854                 key_sa_recordxfer(sav, m);
 855                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 856                         ipsec6stat.in_nomem++;
 857                         goto bad;
 858                 }
 859         }
 860
 861         *offp = off;
 862         *mp = m;
 863
 864         if (sav) {
 865                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 866                         printf("DP esp6_input call free SA:%p\n", sav));
 867                 key_freesav(sav);
 868         }
 869         ipsec6stat.in_success++;
 870         return nxt;
 871
 872 bad:
 873         if (sav) {
 874                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 875                         printf("DP esp6_input call free SA:%p\n", sav));
 876                 key_freesav(sav);
 877         }
 878         if (m)
 879                 m_freem(m);
 880         return IPPROTO_DONE;
 881 }
 882
 883 void
 884 esp6_ctlinput(cmd, sa, d)
 885         int cmd;
 886         struct sockaddr *sa;
 887         void *d;
 888 {
 889         const struct newesp *espp;
 890         struct newesp esp;
 891         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 892         struct secasvar *sav;
 893         struct ip6_hdr *ip6;
 894         struct mbuf *m;
 895         int off;
 896         struct sockaddr_in6 *sa6_src, *sa6_dst;
 897
 898         if (sa->sa_family != AF_INET6 ||
 899             sa->sa_len != sizeof(struct sockaddr_in6))
 900                 return;
 901         if ((unsigned)cmd >= PRC_NCMDS)
 902                 return;
 903
 904         /* if the parameter is from icmp6, decode it. */
 905         if (d != NULL) {
 906                 ip6cp = (struct ip6ctlparam *)d;
 907                 m = ip6cp->ip6c_m;
 908                 ip6 = ip6cp->ip6c_ip6;
 909                 off = ip6cp->ip6c_off;
 910         } else {
 911                 m = NULL;
 912                 ip6 = NULL;
 913                 off = 0; /* fix warning */
 914         }
 915
 916         if (ip6) {
 917                 /*
 918                  * Notify the error to all possible sockets via pfctlinput2.
 919                  * Since the upper layer information (such as protocol type,
 920                  * source and destination ports) is embedded in the encrypted
 921                  * data and might have been cut, we can't directly call
 922                  * an upper layer ctlinput function. However, the pcbnotify
 923                  * function will consider source and destination addresses
 924                  * as well as the flow info value, and may be able to find
 925                  * some PCB that should be notified.
 926                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 927                  * no possibility of an infinite loop of function calls,
 928                  * because we don't pass the inner IPv6 header.
 929                  */
 930                 bzero(&ip6cp1, sizeof(ip6cp1));
 931                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 932                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 933
 934                 /*
 935                  * Then go to special cases that need ESP header information.
 936                  * XXX: We assume that when ip6 is non NULL,
 937                  * M and OFF are valid.
 938                  */
 939
 940                 /* check if we can safely examine src and dst ports */
 941                 if (m->m_pkthdr.len < off + sizeof(esp))
 942                         return;
 943
 944                 if (m->m_len < off + sizeof(esp)) {
 945                         /*
 946                          * this should be rare case,
 947                          * so we compromise on this copy...
 948                          */
 949                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 950                         espp = &esp;
 951                 } else
 952                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 953
 954                 if (cmd == PRC_MSGSIZE) {
 955                         int valid = 0;
 956
 957                         /*
 958                          * Check to see if we have a valid SA corresponding to
 959                          * the address in the ICMP message payload.
 960                          */
 961                         sa6_src = ip6cp->ip6c_src;
 962                         sa6_dst = (struct sockaddr_in6 *)sa;
 963                         sav = key_allocsa(AF_INET6,
 964                                           (caddr_t)&sa6_src->sin6_addr,
 965                                           (caddr_t)&sa6_dst->sin6_addr,
 966                                           IPPROTO_ESP, espp->esp_spi);
 967                         if (sav) {
 968                                 if (sav->state == SADB_SASTATE_MATURE ||
 969                                     sav->state == SADB_SASTATE_DYING)
 970                                         valid++;
 971                                 key_freesav(sav);
 972                         }
 973
 974                         /* XXX Further validation? */
 975
 976                         /*
 977                          * Depending on the value of "valid" and routing table
 978                          * size (mtudisc_{hi,lo}wat), we will:
 979                          * - recalcurate the new MTU and create the
 980                          *   corresponding routing entry, or
 981                          * - ignore the MTU change notification.
 982                          */
 983                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 984                 }
 985         } else {
 986                 /* we normally notify any pcb here */
 987         }
 988 }
 989 #endif /* INET6 */