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 1.17 2008/05/27 01:10:43 dillon 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 extern struct protosw inetsw[];
 102
 103 void
 104 esp4_input(struct mbuf *m, ...)
 105 {
 106         int off, proto;
 107         struct ip *ip;
 108         struct esp *esp;
 109         struct esptail esptail;
 110         u_int32_t spi;
 111         struct secasvar *sav = NULL;
 112         size_t taillen;
 113         u_int16_t nxt;
 114         const struct esp_algorithm *algo;
 115         int ivlen;
 116         size_t hlen;
 117         size_t esplen;
 118         __va_list ap;
 119
 120         __va_start(ap, m);
 121         off = __va_arg(ap, int);
 122         proto = __va_arg(ap, int);
 123         __va_end(ap);
 124
 125         /* sanity check for alignment. */
 126         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 127                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 128                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 129                 ipsecstat.in_inval++;
 130                 goto bad;
 131         }
 132
 133         if (m->m_len < off + ESPMAXLEN) {
 134                 m = m_pullup(m, off + ESPMAXLEN);
 135                 if (!m) {
 136                         ipseclog((LOG_DEBUG,
 137                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 138                         ipsecstat.in_inval++;
 139                         goto bad;
 140                 }
 141         }
 142
 143         ip = mtod(m, struct ip *);
 144         esp = (struct esp *)(((u_int8_t *)ip) + off);
 145 #ifdef _IP_VHL
 146         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 147 #else
 148         hlen = ip->ip_hl << 2;
 149 #endif
 150
 151         /* find the sassoc. */
 152         spi = esp->esp_spi;
 153
 154         if ((sav = key_allocsa(AF_INET,
 155                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 156                               IPPROTO_ESP, spi)) == 0) {
 157                 ipseclog((LOG_WARNING,
 158                     "IPv4 ESP input: no key association found for spi %u\n",
 159                     (u_int32_t)ntohl(spi)));
 160                 ipsecstat.in_nosa++;
 161                 goto bad;
 162         }
 163         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 164                 kprintf("DP esp4_input called to allocate SA:%p\n", sav));
 165         if (sav->state != SADB_SASTATE_MATURE
 166          && sav->state != SADB_SASTATE_DYING) {
 167                 ipseclog((LOG_DEBUG,
 168                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 169                     (u_int32_t)ntohl(spi)));
 170                 ipsecstat.in_badspi++;
 171                 goto bad;
 172         }
 173         algo = esp_algorithm_lookup(sav->alg_enc);
 174         if (!algo) {
 175                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 176                     "unsupported encryption algorithm for spi %u\n",
 177                     (u_int32_t)ntohl(spi)));
 178                 ipsecstat.in_badspi++;
 179                 goto bad;
 180         }
 181
 182         /* check if we have proper ivlen information */
 183         ivlen = sav->ivlen;
 184         if (ivlen < 0) {
 185                 ipseclog((LOG_ERR, "improper ivlen in IPv4 ESP input: %s %s\n",
 186                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 187                 ipsecstat.in_inval++;
 188                 goto bad;
 189         }
 190
 191         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 192          && (sav->alg_auth && sav->key_auth)))
 193                 goto noreplaycheck;
 194
 195         if (sav->alg_auth == SADB_X_AALG_NULL ||
 196             sav->alg_auth == SADB_AALG_NONE)
 197                 goto noreplaycheck;
 198
 199         /*
 200          * check for sequence number.
 201          */
 202         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 203                 ; /* okey */
 204         else {
 205                 ipsecstat.in_espreplay++;
 206                 ipseclog((LOG_WARNING,
 207                     "replay packet in IPv4 ESP input: %s %s\n",
 208                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 209                 goto bad;
 210         }
 211
 212         /* check ICV */
 213     {
 214         u_char sum0[AH_MAXSUMSIZE];
 215         u_char sum[AH_MAXSUMSIZE];
 216         const struct ah_algorithm *sumalgo;
 217         size_t siz;
 218
 219         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 220         if (!sumalgo)
 221                 goto noreplaycheck;
 222         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 223         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 224                 ipsecstat.in_inval++;
 225                 goto bad;
 226         }
 227         if (AH_MAXSUMSIZE < siz) {
 228                 ipseclog((LOG_DEBUG,
 229                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 230                     (u_long)siz));
 231                 ipsecstat.in_inval++;
 232                 goto bad;
 233         }
 234
 235         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 236
 237         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 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         if (bcmp(sum0, sum, siz) != 0) {
 245                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 246                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 247                 ipsecstat.in_espauthfail++;
 248                 goto bad;
 249         }
 250
 251         /* strip off the authentication data */
 252         m_adj(m, -siz);
 253         ip = mtod(m, struct ip *);
 254 #ifdef IPLEN_FLIPPED
 255         ip->ip_len = ip->ip_len - siz;
 256 #else
 257         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 258 #endif
 259         m->m_flags |= M_AUTHIPDGM;
 260         ipsecstat.in_espauthsucc++;
 261     }
 262
 263         /*
 264          * update sequence number.
 265          */
 266         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 267                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 268                         ipsecstat.in_espreplay++;
 269                         goto bad;
 270                 }
 271         }
 272
 273 noreplaycheck:
 274
 275         /* process main esp header. */
 276         if (sav->flags & SADB_X_EXT_OLD) {
 277                 /* RFC 1827 */
 278                 esplen = sizeof(struct esp);
 279         } else {
 280                 /* RFC 2406 */
 281                 if (sav->flags & SADB_X_EXT_DERIV)
 282                         esplen = sizeof(struct esp);
 283                 else
 284                         esplen = sizeof(struct newesp);
 285         }
 286
 287         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 288                 ipseclog((LOG_WARNING,
 289                     "IPv4 ESP input: packet too short\n"));
 290                 ipsecstat.in_inval++;
 291                 goto bad;
 292         }
 293
 294         if (m->m_len < off + esplen + ivlen) {
 295                 m = m_pullup(m, off + esplen + ivlen);
 296                 if (!m) {
 297                         ipseclog((LOG_DEBUG,
 298                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 299                         ipsecstat.in_inval++;
 300                         goto bad;
 301                 }
 302         }
 303
 304         /*
 305          * pre-compute and cache intermediate key
 306          */
 307         if (esp_schedule(algo, sav) != 0) {
 308                 ipsecstat.in_inval++;
 309                 goto bad;
 310         }
 311
 312         /*
 313          * decrypt the packet.
 314          */
 315         if (!algo->decrypt)
 316                 panic("internal error: no decrypt function");
 317         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 318                 /* m is already freed */
 319                 m = NULL;
 320                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 321                     ipsec_logsastr(sav)));
 322                 ipsecstat.in_inval++;
 323                 goto bad;
 324         }
 325         ipsecstat.in_esphist[sav->alg_enc]++;
 326
 327         m->m_flags |= M_DECRYPTED;
 328
 329         /*
 330          * find the trailer of the ESP.
 331          */
 332         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 333              (caddr_t)&esptail);
 334         nxt = esptail.esp_nxt;
 335         taillen = esptail.esp_padlen + sizeof(esptail);
 336
 337         if (m->m_pkthdr.len < taillen ||
 338             m->m_pkthdr.len - taillen < off + esplen + ivlen + sizeof(esptail)) {
 339                 ipseclog((LOG_WARNING,
 340                     "bad pad length in IPv4 ESP input: %s %s\n",
 341                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 342                 ipsecstat.in_inval++;
 343                 goto bad;
 344         }
 345
 346         /* strip off the trailing pad area. */
 347         m_adj(m, -taillen);
 348
 349 #ifdef IPLEN_FLIPPED
 350         ip->ip_len = ip->ip_len - taillen;
 351 #else
 352         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 353 #endif
 354
 355         /* was it transmitted over the IPsec tunnel SA? */
 356         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 357                 /*
 358                  * strip off all the headers that precedes ESP header.
 359                  *      IP4 xx ESP IP4' payload -> IP4' payload
 360                  *
 361                  * XXX more sanity checks
 362                  * XXX relationship with gif?
 363                  */
 364                 u_int8_t tos;
 365
 366                 tos = ip->ip_tos;
 367                 m_adj(m, off + esplen + ivlen);
 368                 if (m->m_len < sizeof(*ip)) {
 369                         m = m_pullup(m, sizeof(*ip));
 370                         if (!m) {
 371                                 ipsecstat.in_inval++;
 372                                 goto bad;
 373                         }
 374                 }
 375                 ip = mtod(m, struct ip *);
 376                 /* ECN consideration. */
 377                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 378                 if (!key_checktunnelsanity(sav, AF_INET,
 379                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 380                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 381                             "in IPv4 ESP input: %s %s\n",
 382                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 383                         ipsecstat.in_inval++;
 384                         goto bad;
 385                 }
 386
 387                 key_sa_recordxfer(sav, m);
 388                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 389                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 390                         ipsecstat.in_nomem++;
 391                         goto bad;
 392                 }
 393
 394                 if (netisr_queue(NETISR_IP, m)) {
 395                         ipsecstat.in_inval++;
 396                         m = NULL;
 397                         goto bad;
 398                 }
 399
 400                 nxt = IPPROTO_DONE;
 401         } else {
 402                 /*
 403                  * strip off ESP header and IV.
 404                  * even in m_pulldown case, we need to strip off ESP so that
 405                  * we can always compute checksum for AH correctly.
 406                  */
 407                 size_t stripsiz;
 408
 409                 stripsiz = esplen + ivlen;
 410
 411                 ip = mtod(m, struct ip *);
 412                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 413                 m->m_data += stripsiz;
 414                 m->m_len -= stripsiz;
 415                 m->m_pkthdr.len -= stripsiz;
 416
 417                 ip = mtod(m, struct ip *);
 418 #ifdef IPLEN_FLIPPED
 419                 ip->ip_len = ip->ip_len - stripsiz;
 420 #else
 421                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 422 #endif
 423                 ip->ip_p = nxt;
 424
 425                 key_sa_recordxfer(sav, m);
 426                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 427                         ipsecstat.in_nomem++;
 428                         goto bad;
 429                 }
 430
 431                 if (nxt != IPPROTO_DONE) {
 432                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 433                             ipsec4_in_reject(m, NULL)) {
 434                                 ipsecstat.in_polvio++;
 435                                 goto bad;
 436                         }
 437                         if (!ip_lengthcheck(&m)) {
 438                                 /* freed in ip_lengthcheck() */
 439                                 goto bad;
 440                         }
 441                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 442                 } else
 443                         m_freem(m);
 444                 m = NULL;
 445         }
 446
 447         if (sav) {
 448                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 449                         kprintf("DP esp4_input call free SA:%p\n", sav));
 450                 key_freesav(sav);
 451         }
 452         ipsecstat.in_success++;
 453         return;
 454
 455 bad:
 456         if (sav) {
 457                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 458                         kprintf("DP esp4_input call free SA:%p\n", sav));
 459                 key_freesav(sav);
 460         }
 461         if (m)
 462                 m_freem(m);
 463         return;
 464 }
 465 #endif /* INET */
 466
 467 #ifdef INET6
 468 int
 469 esp6_input(struct mbuf **mp, int *offp, int 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                 kprintf("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, "improper 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 (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 584                 ipsec6stat.in_inval++;
 585                 goto bad;
 586         }
 587         if (AH_MAXSUMSIZE < siz) {
 588                 ipseclog((LOG_DEBUG,
 589                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 590                     (u_long)siz));
 591                 ipsec6stat.in_inval++;
 592                 goto bad;
 593         }
 594
 595         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 596
 597         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 598                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 599                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 600                 ipsec6stat.in_espauthfail++;
 601                 goto bad;
 602         }
 603
 604         if (bcmp(sum0, sum, siz) != 0) {
 605                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 606                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 607                 ipsec6stat.in_espauthfail++;
 608                 goto bad;
 609         }
 610
 611         /* strip off the authentication data */
 612         m_adj(m, -siz);
 613         ip6 = mtod(m, struct ip6_hdr *);
 614         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 615
 616         m->m_flags |= M_AUTHIPDGM;
 617         ipsec6stat.in_espauthsucc++;
 618     }
 619
 620         /*
 621          * update sequence number.
 622          */
 623         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 624                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 625                         ipsec6stat.in_espreplay++;
 626                         goto bad;
 627                 }
 628         }
 629
 630 noreplaycheck:
 631
 632         /* process main esp header. */
 633         if (sav->flags & SADB_X_EXT_OLD) {
 634                 /* RFC 1827 */
 635                 esplen = sizeof(struct esp);
 636         } else {
 637                 /* RFC 2406 */
 638                 if (sav->flags & SADB_X_EXT_DERIV)
 639                         esplen = sizeof(struct esp);
 640                 else
 641                         esplen = sizeof(struct newesp);
 642         }
 643
 644         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 645                 ipseclog((LOG_WARNING,
 646                     "IPv6 ESP input: packet too short\n"));
 647                 ipsec6stat.in_inval++;
 648                 goto bad;
 649         }
 650
 651 #ifndef PULLDOWN_TEST
 652         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 653 #else
 654         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 655         if (esp == NULL) {
 656                 ipsec6stat.in_inval++;
 657                 m = NULL;
 658                 goto bad;
 659         }
 660 #endif
 661         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 662
 663         /*
 664          * pre-compute and cache intermediate key
 665          */
 666         if (esp_schedule(algo, sav) != 0) {
 667                 ipsec6stat.in_inval++;
 668                 goto bad;
 669         }
 670
 671         /*
 672          * decrypt the packet.
 673          */
 674         if (!algo->decrypt)
 675                 panic("internal error: no decrypt function");
 676         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 677                 /* m is already freed */
 678                 m = NULL;
 679                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 680                     ipsec_logsastr(sav)));
 681                 ipsec6stat.in_inval++;
 682                 goto bad;
 683         }
 684         ipsec6stat.in_esphist[sav->alg_enc]++;
 685
 686         m->m_flags |= M_DECRYPTED;
 687
 688         /*
 689          * find the trailer of the ESP.
 690          */
 691         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 692              (caddr_t)&esptail);
 693         nxt = esptail.esp_nxt;
 694         taillen = esptail.esp_padlen + sizeof(esptail);
 695
 696         if (m->m_pkthdr.len < taillen
 697          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 698                 ipseclog((LOG_WARNING,
 699                     "bad pad length in IPv6 ESP input: %s %s\n",
 700                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 701                 ipsec6stat.in_inval++;
 702                 goto bad;
 703         }
 704
 705         /* strip off the trailing pad area. */
 706         m_adj(m, -taillen);
 707
 708         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 709
 710         /* was it transmitted over the IPsec tunnel SA? */
 711         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 712                 /*
 713                  * strip off all the headers that precedes ESP header.
 714                  *      IP6 xx ESP IP6' payload -> IP6' payload
 715                  *
 716                  * XXX more sanity checks
 717                  * XXX relationship with gif?
 718                  */
 719                 u_int32_t flowinfo;     /* net endian */
 720                 flowinfo = ip6->ip6_flow;
 721                 m_adj(m, off + esplen + ivlen);
 722                 if (m->m_len < sizeof(*ip6)) {
 723 #ifndef PULLDOWN_TEST
 724                         /*
 725                          * m_pullup is prohibited in KAME IPv6 input processing
 726                          * but there's no other way!
 727                          */
 728 #else
 729                         /* okay to pullup in m_pulldown style */
 730 #endif
 731                         m = m_pullup(m, sizeof(*ip6));
 732                         if (!m) {
 733                                 ipsec6stat.in_inval++;
 734                                 goto bad;
 735                         }
 736                 }
 737                 ip6 = mtod(m, struct ip6_hdr *);
 738                 /* ECN consideration. */
 739                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 740                 if (!key_checktunnelsanity(sav, AF_INET6,
 741                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 742                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 743                             "in IPv6 ESP input: %s %s\n",
 744                             ipsec6_logpacketstr(ip6, spi),
 745                             ipsec_logsastr(sav)));
 746                         ipsec6stat.in_inval++;
 747                         goto bad;
 748                 }
 749
 750                 key_sa_recordxfer(sav, m);
 751                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 752                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 753                         ipsec6stat.in_nomem++;
 754                         goto bad;
 755                 }
 756
 757                 if (netisr_queue(NETISR_IPV6, m)) {
 758                         ipsec6stat.in_inval++;
 759                         m = NULL;
 760                         goto bad;
 761                 }
 762
 763                 nxt = IPPROTO_DONE;
 764         } else {
 765                 /*
 766                  * strip off ESP header and IV.
 767                  * even in m_pulldown case, we need to strip off ESP so that
 768                  * we can always compute checksum for AH correctly.
 769                  */
 770                 size_t stripsiz;
 771                 char *prvnxtp;
 772
 773                 /*
 774                  * Set the next header field of the previous header correctly.
 775                  */
 776                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 777                 *prvnxtp = nxt;
 778
 779                 stripsiz = esplen + ivlen;
 780
 781                 ip6 = mtod(m, struct ip6_hdr *);
 782                 if (m->m_len >= stripsiz + off) {
 783                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 784                         m->m_data += stripsiz;
 785                         m->m_len -= stripsiz;
 786                         m->m_pkthdr.len -= stripsiz;
 787                 } else {
 788                         /*
 789                          * this comes with no copy if the boundary is on
 790                          * cluster
 791                          */
 792                         struct mbuf *n;
 793
 794                         n = m_split(m, off, MB_DONTWAIT);
 795                         if (n == NULL) {
 796                                 /* m is retained by m_split */
 797                                 goto bad;
 798                         }
 799                         m_adj(n, stripsiz);
 800                         /* m_cat does not update m_pkthdr.len */
 801                         m->m_pkthdr.len += n->m_pkthdr.len;
 802                         m_cat(m, n);
 803                 }
 804
 805 #ifndef PULLDOWN_TEST
 806                 /*
 807                  * KAME requires that the packet to be contiguous on the
 808                  * mbuf.  We need to make that sure.
 809                  * this kind of code should be avoided.
 810                  * XXX other conditions to avoid running this part?
 811                  */
 812                 if (m->m_len != m->m_pkthdr.len) {
 813                         struct mbuf *n = NULL;
 814                         int maxlen;
 815
 816                         n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER,
 817                                    M_PKTHDR);
 818                         if (!n) {
 819                                 kprintf("esp6_input: mbuf allocation failed\n");
 820                                 goto bad;
 821                         }
 822                         M_MOVE_PKTHDR(n, m);
 823
 824                         maxlen = (n->m_flags & M_EXT) ? MCLBYTES : MHLEN;
 825                         if (n->m_pkthdr.len <= maxlen) {
 826                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 827                                 n->m_len = n->m_pkthdr.len;
 828                                 n->m_next = NULL;
 829                                 m_freem(m);
 830                         } else {
 831                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 832                                 n->m_len = maxlen;
 833                                 n->m_next = m;
 834                                 m_adj(m, maxlen);
 835                         }
 836                         m = n;
 837                 }
 838 #endif
 839
 840                 ip6 = mtod(m, struct ip6_hdr *);
 841                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 842
 843                 key_sa_recordxfer(sav, m);
 844                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 845                         ipsec6stat.in_nomem++;
 846                         goto bad;
 847                 }
 848         }
 849
 850         *offp = off;
 851         *mp = m;
 852
 853         if (sav) {
 854                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 855                         kprintf("DP esp6_input call free SA:%p\n", sav));
 856                 key_freesav(sav);
 857         }
 858         ipsec6stat.in_success++;
 859         return nxt;
 860
 861 bad:
 862         if (sav) {
 863                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 864                         kprintf("DP esp6_input call free SA:%p\n", sav));
 865                 key_freesav(sav);
 866         }
 867         if (m)
 868                 m_freem(m);
 869         return IPPROTO_DONE;
 870 }
 871
 872 void
 873 esp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 874 {
 875         const struct newesp *espp;
 876         struct newesp esp;
 877         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 878         struct secasvar *sav;
 879         struct ip6_hdr *ip6;
 880         struct mbuf *m;
 881         int off;
 882         struct sockaddr_in6 *sa6_src, *sa6_dst;
 883
 884         if (sa->sa_family != AF_INET6 ||
 885             sa->sa_len != sizeof(struct sockaddr_in6))
 886                 return;
 887         if ((unsigned)cmd >= PRC_NCMDS)
 888                 return;
 889
 890         /* if the parameter is from icmp6, decode it. */
 891         if (d != NULL) {
 892                 ip6cp = (struct ip6ctlparam *)d;
 893                 m = ip6cp->ip6c_m;
 894                 ip6 = ip6cp->ip6c_ip6;
 895                 off = ip6cp->ip6c_off;
 896         } else {
 897                 m = NULL;
 898                 ip6 = NULL;
 899                 off = 0; /* fix warning */
 900         }
 901
 902         if (ip6) {
 903                 /*
 904                  * Notify the error to all possible sockets via pfctlinput2.
 905                  * Since the upper layer information (such as protocol type,
 906                  * source and destination ports) is embedded in the encrypted
 907                  * data and might have been cut, we can't directly call
 908                  * an upper layer ctlinput function. However, the pcbnotify
 909                  * function will consider source and destination addresses
 910                  * as well as the flow info value, and may be able to find
 911                  * some PCB that should be notified.
 912                  * Although kpfctlinput2 will call esp6_ctlinput(), there is
 913                  * no possibility of an infinite loop of function calls,
 914                  * because we don't pass the inner IPv6 header.
 915                  */
 916                 bzero(&ip6cp1, sizeof(ip6cp1));
 917                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 918                 kpfctlinput2(cmd, sa, (void *)&ip6cp1);
 919
 920                 /*
 921                  * Then go to special cases that need ESP header information.
 922                  * XXX: We assume that when ip6 is non NULL,
 923                  * M and OFF are valid.
 924                  */
 925
 926                 /* check if we can safely examine src and dst ports */
 927                 if (m->m_pkthdr.len < off + sizeof(esp))
 928                         return;
 929
 930                 if (m->m_len < off + sizeof(esp)) {
 931                         /*
 932                          * this should be rare case,
 933                          * so we compromise on this copy...
 934                          */
 935                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 936                         espp = &esp;
 937                 } else
 938                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 939
 940                 if (cmd == PRC_MSGSIZE) {
 941                         int valid = 0;
 942
 943                         /*
 944                          * Check to see if we have a valid SA corresponding to
 945                          * the address in the ICMP message payload.
 946                          */
 947                         sa6_src = ip6cp->ip6c_src;
 948                         sa6_dst = (struct sockaddr_in6 *)sa;
 949                         sav = key_allocsa(AF_INET6,
 950                                           (caddr_t)&sa6_src->sin6_addr,
 951                                           (caddr_t)&sa6_dst->sin6_addr,
 952                                           IPPROTO_ESP, espp->esp_spi);
 953                         if (sav) {
 954                                 if (sav->state == SADB_SASTATE_MATURE ||
 955                                     sav->state == SADB_SASTATE_DYING)
 956                                         valid++;
 957                                 key_freesav(sav);
 958                         }
 959
 960                         /* XXX Further validation? */
 961
 962                         /*
 963                          * Depending on the value of "valid" and routing table
 964                          * size (mtudisc_{hi,lo}wat), we will:
 965                          * - recalcurate the new MTU and create the
 966                          *   corresponding routing entry, or
 967                          * - ignore the MTU change notification.
 968                          */
 969                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 970                 }
 971         } else {
 972                 /* we normally notify any pcb here */
 973         }
 974 }
 975 #endif /* INET6 */