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 1.9 2004/11/30 19:21:26 joerg 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                 printf("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, "inproper 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 < hlen) { /* ? */
 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                                 m = NULL;       /* 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                         printf("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                         printf("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(mp, offp, proto)
 470         struct mbuf **mp;
 471         int *offp, proto;
 472 {
 473         struct mbuf *m = *mp;
 474         int off = *offp;
 475         struct ip6_hdr *ip6;
 476         struct esp *esp;
 477         struct esptail esptail;
 478         u_int32_t spi;
 479         struct secasvar *sav = NULL;
 480         size_t taillen;
 481         u_int16_t nxt;
 482         const struct esp_algorithm *algo;
 483         int ivlen;
 484         size_t esplen;
 485
 486         /* sanity check for alignment. */
 487         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 488                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 489                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 490                 ipsec6stat.in_inval++;
 491                 goto bad;
 492         }
 493
 494 #ifndef PULLDOWN_TEST
 495         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 496         esp = (struct esp *)(mtod(m, caddr_t) + off);
 497 #else
 498         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 499         if (esp == NULL) {
 500                 ipsec6stat.in_inval++;
 501                 return IPPROTO_DONE;
 502         }
 503 #endif
 504         ip6 = mtod(m, struct ip6_hdr *);
 505
 506         if (ntohs(ip6->ip6_plen) == 0) {
 507                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 508                     "ESP with IPv6 jumbogram is not supported.\n"));
 509                 ipsec6stat.in_inval++;
 510                 goto bad;
 511         }
 512
 513         /* find the sassoc. */
 514         spi = esp->esp_spi;
 515
 516         if ((sav = key_allocsa(AF_INET6,
 517                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 518                               IPPROTO_ESP, spi)) == 0) {
 519                 ipseclog((LOG_WARNING,
 520                     "IPv6 ESP input: no key association found for spi %u\n",
 521                     (u_int32_t)ntohl(spi)));
 522                 ipsec6stat.in_nosa++;
 523                 goto bad;
 524         }
 525         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 526                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 527         if (sav->state != SADB_SASTATE_MATURE
 528          && sav->state != SADB_SASTATE_DYING) {
 529                 ipseclog((LOG_DEBUG,
 530                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 531                     (u_int32_t)ntohl(spi)));
 532                 ipsec6stat.in_badspi++;
 533                 goto bad;
 534         }
 535         algo = esp_algorithm_lookup(sav->alg_enc);
 536         if (!algo) {
 537                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 538                     "unsupported encryption algorithm for spi %u\n",
 539                     (u_int32_t)ntohl(spi)));
 540                 ipsec6stat.in_badspi++;
 541                 goto bad;
 542         }
 543
 544         /* check if we have proper ivlen information */
 545         ivlen = sav->ivlen;
 546         if (ivlen < 0) {
 547                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 548                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 549                 ipsec6stat.in_badspi++;
 550                 goto bad;
 551         }
 552
 553         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 554          && (sav->alg_auth && sav->key_auth)))
 555                 goto noreplaycheck;
 556
 557         if (sav->alg_auth == SADB_X_AALG_NULL ||
 558             sav->alg_auth == SADB_AALG_NONE)
 559                 goto noreplaycheck;
 560
 561         /*
 562          * check for sequence number.
 563          */
 564         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 565                 ; /* okey */
 566         else {
 567                 ipsec6stat.in_espreplay++;
 568                 ipseclog((LOG_WARNING,
 569                     "replay packet in IPv6 ESP input: %s %s\n",
 570                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 571                 goto bad;
 572         }
 573
 574         /* check ICV */
 575     {
 576         u_char sum0[AH_MAXSUMSIZE];
 577         u_char sum[AH_MAXSUMSIZE];
 578         const struct ah_algorithm *sumalgo;
 579         size_t siz;
 580
 581         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 582         if (!sumalgo)
 583                 goto noreplaycheck;
 584         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 585         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 586                 ipsecstat.in_inval++;
 587                 goto bad;
 588         }
 589         if (AH_MAXSUMSIZE < siz) {
 590                 ipseclog((LOG_DEBUG,
 591                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 592                     (u_long)siz));
 593                 ipsec6stat.in_inval++;
 594                 goto bad;
 595         }
 596
 597         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 598
 599         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 600                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 601                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 602                 ipsec6stat.in_espauthfail++;
 603                 goto bad;
 604         }
 605
 606         if (bcmp(sum0, sum, siz) != 0) {
 607                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 608                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 609                 ipsec6stat.in_espauthfail++;
 610                 goto bad;
 611         }
 612
 613         /* strip off the authentication data */
 614         m_adj(m, -siz);
 615         ip6 = mtod(m, struct ip6_hdr *);
 616         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 617
 618         m->m_flags |= M_AUTHIPDGM;
 619         ipsec6stat.in_espauthsucc++;
 620     }
 621
 622         /*
 623          * update sequence number.
 624          */
 625         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 626                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 627                         ipsec6stat.in_espreplay++;
 628                         goto bad;
 629                 }
 630         }
 631
 632 noreplaycheck:
 633
 634         /* process main esp header. */
 635         if (sav->flags & SADB_X_EXT_OLD) {
 636                 /* RFC 1827 */
 637                 esplen = sizeof(struct esp);
 638         } else {
 639                 /* RFC 2406 */
 640                 if (sav->flags & SADB_X_EXT_DERIV)
 641                         esplen = sizeof(struct esp);
 642                 else
 643                         esplen = sizeof(struct newesp);
 644         }
 645
 646         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 647                 ipseclog((LOG_WARNING,
 648                     "IPv6 ESP input: packet too short\n"));
 649                 ipsec6stat.in_inval++;
 650                 goto bad;
 651         }
 652
 653 #ifndef PULLDOWN_TEST
 654         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 655 #else
 656         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 657         if (esp == NULL) {
 658                 ipsec6stat.in_inval++;
 659                 m = NULL;
 660                 goto bad;
 661         }
 662 #endif
 663         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 664
 665         /*
 666          * pre-compute and cache intermediate key
 667          */
 668         if (esp_schedule(algo, sav) != 0) {
 669                 ipsec6stat.in_inval++;
 670                 goto bad;
 671         }
 672
 673         /*
 674          * decrypt the packet.
 675          */
 676         if (!algo->decrypt)
 677                 panic("internal error: no decrypt function");
 678         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 679                 /* m is already freed */
 680                 m = NULL;
 681                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 682                     ipsec_logsastr(sav)));
 683                 ipsec6stat.in_inval++;
 684                 goto bad;
 685         }
 686         ipsec6stat.in_esphist[sav->alg_enc]++;
 687
 688         m->m_flags |= M_DECRYPTED;
 689
 690         /*
 691          * find the trailer of the ESP.
 692          */
 693         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 694              (caddr_t)&esptail);
 695         nxt = esptail.esp_nxt;
 696         taillen = esptail.esp_padlen + sizeof(esptail);
 697
 698         if (m->m_pkthdr.len < taillen
 699          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 700                 ipseclog((LOG_WARNING,
 701                     "bad pad length in IPv6 ESP input: %s %s\n",
 702                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 703                 ipsec6stat.in_inval++;
 704                 goto bad;
 705         }
 706
 707         /* strip off the trailing pad area. */
 708         m_adj(m, -taillen);
 709
 710         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 711
 712         /* was it transmitted over the IPsec tunnel SA? */
 713         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 714                 /*
 715                  * strip off all the headers that precedes ESP header.
 716                  *      IP6 xx ESP IP6' payload -> IP6' payload
 717                  *
 718                  * XXX more sanity checks
 719                  * XXX relationship with gif?
 720                  */
 721                 u_int32_t flowinfo;     /* net endian */
 722                 flowinfo = ip6->ip6_flow;
 723                 m_adj(m, off + esplen + ivlen);
 724                 if (m->m_len < sizeof(*ip6)) {
 725 #ifndef PULLDOWN_TEST
 726                         /*
 727                          * m_pullup is prohibited in KAME IPv6 input processing
 728                          * but there's no other way!
 729                          */
 730 #else
 731                         /* okay to pullup in m_pulldown style */
 732 #endif
 733                         m = m_pullup(m, sizeof(*ip6));
 734                         if (!m) {
 735                                 ipsec6stat.in_inval++;
 736                                 goto bad;
 737                         }
 738                 }
 739                 ip6 = mtod(m, struct ip6_hdr *);
 740                 /* ECN consideration. */
 741                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 742                 if (!key_checktunnelsanity(sav, AF_INET6,
 743                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 744                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 745                             "in IPv6 ESP input: %s %s\n",
 746                             ipsec6_logpacketstr(ip6, spi),
 747                             ipsec_logsastr(sav)));
 748                         ipsec6stat.in_inval++;
 749                         goto bad;
 750                 }
 751
 752                 key_sa_recordxfer(sav, m);
 753                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 754                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 755                         ipsec6stat.in_nomem++;
 756                         goto bad;
 757                 }
 758
 759                 if (netisr_queue(NETISR_IPV6, m)) {
 760                         ipsec6stat.in_inval++;
 761                         m = NULL;
 762                         goto bad;
 763                 }
 764
 765                 nxt = IPPROTO_DONE;
 766         } else {
 767                 /*
 768                  * strip off ESP header and IV.
 769                  * even in m_pulldown case, we need to strip off ESP so that
 770                  * we can always compute checksum for AH correctly.
 771                  */
 772                 size_t stripsiz;
 773                 char *prvnxtp;
 774
 775                 /*
 776                  * Set the next header field of the previous header correctly.
 777                  */
 778                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 779                 *prvnxtp = nxt;
 780
 781                 stripsiz = esplen + ivlen;
 782
 783                 ip6 = mtod(m, struct ip6_hdr *);
 784                 if (m->m_len >= stripsiz + off) {
 785                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 786                         m->m_data += stripsiz;
 787                         m->m_len -= stripsiz;
 788                         m->m_pkthdr.len -= stripsiz;
 789                 } else {
 790                         /*
 791                          * this comes with no copy if the boundary is on
 792                          * cluster
 793                          */
 794                         struct mbuf *n;
 795
 796                         n = m_split(m, off, MB_DONTWAIT);
 797                         if (n == NULL) {
 798                                 /* m is retained by m_split */
 799                                 goto bad;
 800                         }
 801                         m_adj(n, stripsiz);
 802                         m_cat(m, n);
 803                         /* m_cat does not update m_pkthdr.len */
 804                         m->m_pkthdr.len += n->m_pkthdr.len;
 805                 }
 806
 807 #ifndef PULLDOWN_TEST
 808                 /*
 809                  * KAME requires that the packet to be contiguous on the
 810                  * mbuf.  We need to make that sure.
 811                  * this kind of code should be avoided.
 812                  * XXX other conditions to avoid running this part?
 813                  */
 814                 if (m->m_len != m->m_pkthdr.len) {
 815                         struct mbuf *n = NULL;
 816                         int maxlen;
 817
 818                         MGETHDR(n, MB_DONTWAIT, MT_HEADER);
 819                         maxlen = MHLEN;
 820                         if (n)
 821                                 M_MOVE_PKTHDR(n, m);
 822                         if (n && n->m_pkthdr.len > maxlen) {
 823                                 MCLGET(n, MB_DONTWAIT);
 824                                 maxlen = MCLBYTES;
 825                                 if ((n->m_flags & M_EXT) == 0) {
 826                                         m_free(n);
 827                                         n = NULL;
 828                                 }
 829                         }
 830                         if (!n) {
 831                                 printf("esp6_input: mbuf allocation failed\n");
 832                                 goto bad;
 833                         }
 834
 835                         if (n->m_pkthdr.len <= maxlen) {
 836                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 837                                 n->m_len = n->m_pkthdr.len;
 838                                 n->m_next = NULL;
 839                                 m_freem(m);
 840                         } else {
 841                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 842                                 n->m_len = maxlen;
 843                                 n->m_next = m;
 844                                 m_adj(m, maxlen);
 845                         }
 846                         m = n;
 847                 }
 848 #endif
 849
 850                 ip6 = mtod(m, struct ip6_hdr *);
 851                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 852
 853                 key_sa_recordxfer(sav, m);
 854                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 855                         ipsec6stat.in_nomem++;
 856                         goto bad;
 857                 }
 858         }
 859
 860         *offp = off;
 861         *mp = m;
 862
 863         if (sav) {
 864                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 865                         printf("DP esp6_input call free SA:%p\n", sav));
 866                 key_freesav(sav);
 867         }
 868         ipsec6stat.in_success++;
 869         return nxt;
 870
 871 bad:
 872         if (sav) {
 873                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 874                         printf("DP esp6_input call free SA:%p\n", sav));
 875                 key_freesav(sav);
 876         }
 877         if (m)
 878                 m_freem(m);
 879         return IPPROTO_DONE;
 880 }
 881
 882 void
 883 esp6_ctlinput(cmd, sa, d)
 884         int cmd;
 885         struct sockaddr *sa;
 886         void *d;
 887 {
 888         const struct newesp *espp;
 889         struct newesp esp;
 890         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 891         struct secasvar *sav;
 892         struct ip6_hdr *ip6;
 893         struct mbuf *m;
 894         int off;
 895         struct sockaddr_in6 *sa6_src, *sa6_dst;
 896
 897         if (sa->sa_family != AF_INET6 ||
 898             sa->sa_len != sizeof(struct sockaddr_in6))
 899                 return;
 900         if ((unsigned)cmd >= PRC_NCMDS)
 901                 return;
 902
 903         /* if the parameter is from icmp6, decode it. */
 904         if (d != NULL) {
 905                 ip6cp = (struct ip6ctlparam *)d;
 906                 m = ip6cp->ip6c_m;
 907                 ip6 = ip6cp->ip6c_ip6;
 908                 off = ip6cp->ip6c_off;
 909         } else {
 910                 m = NULL;
 911                 ip6 = NULL;
 912                 off = 0; /* fix warning */
 913         }
 914
 915         if (ip6) {
 916                 /*
 917                  * Notify the error to all possible sockets via pfctlinput2.
 918                  * Since the upper layer information (such as protocol type,
 919                  * source and destination ports) is embedded in the encrypted
 920                  * data and might have been cut, we can't directly call
 921                  * an upper layer ctlinput function. However, the pcbnotify
 922                  * function will consider source and destination addresses
 923                  * as well as the flow info value, and may be able to find
 924                  * some PCB that should be notified.
 925                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 926                  * no possibility of an infinite loop of function calls,
 927                  * because we don't pass the inner IPv6 header.
 928                  */
 929                 bzero(&ip6cp1, sizeof(ip6cp1));
 930                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 931                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 932
 933                 /*
 934                  * Then go to special cases that need ESP header information.
 935                  * XXX: We assume that when ip6 is non NULL,
 936                  * M and OFF are valid.
 937                  */
 938
 939                 /* check if we can safely examine src and dst ports */
 940                 if (m->m_pkthdr.len < off + sizeof(esp))
 941                         return;
 942
 943                 if (m->m_len < off + sizeof(esp)) {
 944                         /*
 945                          * this should be rare case,
 946                          * so we compromise on this copy...
 947                          */
 948                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 949                         espp = &esp;
 950                 } else
 951                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 952
 953                 if (cmd == PRC_MSGSIZE) {
 954                         int valid = 0;
 955
 956                         /*
 957                          * Check to see if we have a valid SA corresponding to
 958                          * the address in the ICMP message payload.
 959                          */
 960                         sa6_src = ip6cp->ip6c_src;
 961                         sa6_dst = (struct sockaddr_in6 *)sa;
 962                         sav = key_allocsa(AF_INET6,
 963                                           (caddr_t)&sa6_src->sin6_addr,
 964                                           (caddr_t)&sa6_dst->sin6_addr,
 965                                           IPPROTO_ESP, espp->esp_spi);
 966                         if (sav) {
 967                                 if (sav->state == SADB_SASTATE_MATURE ||
 968                                     sav->state == SADB_SASTATE_DYING)
 969                                         valid++;
 970                                 key_freesav(sav);
 971                         }
 972
 973                         /* XXX Further validation? */
 974
 975                         /*
 976                          * Depending on the value of "valid" and routing table
 977                          * size (mtudisc_{hi,lo}wat), we will:
 978                          * - recalcurate the new MTU and create the
 979                          *   corresponding routing entry, or
 980                          * - ignore the MTU change notification.
 981                          */
 982                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 983                 }
 984         } else {
 985                 /* we normally notify any pcb here */
 986         }
 987 }
 988 #endif /* INET6 */