sys/netinet6/esp_input.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: esp_input.c,v 1.55 2001/03/23 08:08:47 itojun Exp $      */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * RFC1827/2406 Encapsulated Security Payload.
  35  */
  36
  37 #include "opt_inet.h"
  38 #include "opt_inet6.h"
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/domain.h>
  44 #include <sys/protosw.h>
  45 #include <sys/socket.h>
  46 #include <sys/errno.h>
  47 #include <sys/time.h>
  48 #include <sys/syslog.h>
  49
  50 #include <net/if.h>
  51 #include <net/route.h>
  52 #include <net/netisr.h>
  53 #include <machine/cpu.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58 #include <netinet/ip_var.h>
  59 #include <netinet/in_var.h>
  60 #include <netinet/ip_ecn.h>
  61 #ifdef INET6
  62 #include <netinet6/ip6_ecn.h>
  63 #endif
  64
  65 #ifdef INET6
  66 #include <netinet/ip6.h>
  67 #include <netinet6/in6_pcb.h>
  68 #include <netinet6/ip6_var.h>
  69 #include <netinet/icmp6.h>
  70 #include <netinet6/ip6protosw.h>
  71 #endif
  72
  73 #include <netinet6/ipsec.h>
  74 #ifdef INET6
  75 #include <netinet6/ipsec6.h>
  76 #endif
  77 #include <netinet6/ah.h>
  78 #ifdef INET6
  79 #include <netinet6/ah6.h>
  80 #endif
  81 #include <netinet6/esp.h>
  82 #ifdef INET6
  83 #include <netinet6/esp6.h>
  84 #endif
  85 #include <netkey/key.h>
  86 #include <netkey/keydb.h>
  87 #include <netkey/key_debug.h>
  88
  89 #include <machine/stdarg.h>
  90
  91 #include <net/net_osdep.h>
  92
  93 #define IPLEN_FLIPPED
  94
  95 #define ESPMAXLEN \
  96         (sizeof(struct esp) < sizeof(struct newesp) \
  97                 ? sizeof(struct newesp) : sizeof(struct esp))
  98
  99 #ifdef INET
 100 extern struct protosw inetsw[];
 101
 102 void
 103 esp4_input(m, off)
 104         struct mbuf *m;
 105         int off;
 106 {
 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         int proto;
 119
 120         /* sanity check for alignment. */
 121         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 122                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 123                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 124                 ipsecstat.in_inval++;
 125                 goto bad;
 126         }
 127
 128         if (m->m_len < off + ESPMAXLEN) {
 129                 m = m_pullup(m, off + ESPMAXLEN);
 130                 if (!m) {
 131                         ipseclog((LOG_DEBUG,
 132                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 133                         ipsecstat.in_inval++;
 134                         goto bad;
 135                 }
 136         }
 137
 138         ip = mtod(m, struct ip *);
 139         proto = ip->ip_p;
 140         esp = (struct esp *)(((u_int8_t *)ip) + off);
 141 #ifdef _IP_VHL
 142         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 143 #else
 144         hlen = ip->ip_hl << 2;
 145 #endif
 146
 147         /* find the sassoc. */
 148         spi = esp->esp_spi;
 149
 150         if ((sav = key_allocsa(AF_INET,
 151                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 152                               IPPROTO_ESP, spi)) == 0) {
 153                 ipseclog((LOG_WARNING,
 154                     "IPv4 ESP input: no key association found for spi %u\n",
 155                     (u_int32_t)ntohl(spi)));
 156                 ipsecstat.in_nosa++;
 157                 goto bad;
 158         }
 159         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 160                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 161         if (sav->state != SADB_SASTATE_MATURE
 162          && sav->state != SADB_SASTATE_DYING) {
 163                 ipseclog((LOG_DEBUG,
 164                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 165                     (u_int32_t)ntohl(spi)));
 166                 ipsecstat.in_badspi++;
 167                 goto bad;
 168         }
 169         algo = esp_algorithm_lookup(sav->alg_enc);
 170         if (!algo) {
 171                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 172                     "unsupported encryption algorithm for spi %u\n",
 173                     (u_int32_t)ntohl(spi)));
 174                 ipsecstat.in_badspi++;
 175                 goto bad;
 176         }
 177
 178         /* check if we have proper ivlen information */
 179         ivlen = sav->ivlen;
 180         if (ivlen < 0) {
 181                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 182                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 183                 ipsecstat.in_inval++;
 184                 goto bad;
 185         }
 186
 187         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 188          && (sav->alg_auth && sav->key_auth)))
 189                 goto noreplaycheck;
 190
 191         if (sav->alg_auth == SADB_X_AALG_NULL ||
 192             sav->alg_auth == SADB_AALG_NONE)
 193                 goto noreplaycheck;
 194
 195         /*
 196          * check for sequence number.
 197          */
 198         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 199                 ; /*okey*/
 200         else {
 201                 ipsecstat.in_espreplay++;
 202                 ipseclog((LOG_WARNING,
 203                     "replay packet in IPv4 ESP input: %s %s\n",
 204                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 205                 goto bad;
 206         }
 207
 208         /* check ICV */
 209     {
 210         u_char sum0[AH_MAXSUMSIZE];
 211         u_char sum[AH_MAXSUMSIZE];
 212         const struct ah_algorithm *sumalgo;
 213         size_t siz;
 214
 215         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 216         if (!sumalgo)
 217                 goto noreplaycheck;
 218         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 219         if (AH_MAXSUMSIZE < siz) {
 220                 ipseclog((LOG_DEBUG,
 221                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 222                     (u_long)siz));
 223                 ipsecstat.in_inval++;
 224                 goto bad;
 225         }
 226
 227         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 228
 229         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 230                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 231                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 232                 ipsecstat.in_espauthfail++;
 233                 goto bad;
 234         }
 235
 236         if (bcmp(sum0, sum, siz) != 0) {
 237                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 238                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 239                 ipsecstat.in_espauthfail++;
 240                 goto bad;
 241         }
 242
 243         /* strip off the authentication data */
 244         m_adj(m, -siz);
 245         ip = mtod(m, struct ip *);
 246 #ifdef IPLEN_FLIPPED
 247         ip->ip_len = ip->ip_len - siz;
 248 #else
 249         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 250 #endif
 251         m->m_flags |= M_AUTHIPDGM;
 252         ipsecstat.in_espauthsucc++;
 253     }
 254
 255         /*
 256          * update sequence number.
 257          */
 258         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 259                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 260                         ipsecstat.in_espreplay++;
 261                         goto bad;
 262                 }
 263         }
 264
 265 noreplaycheck:
 266
 267         /* process main esp header. */
 268         if (sav->flags & SADB_X_EXT_OLD) {
 269                 /* RFC 1827 */
 270                 esplen = sizeof(struct esp);
 271         } else {
 272                 /* RFC 2406 */
 273                 if (sav->flags & SADB_X_EXT_DERIV)
 274                         esplen = sizeof(struct esp);
 275                 else
 276                         esplen = sizeof(struct newesp);
 277         }
 278
 279         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 280                 ipseclog((LOG_WARNING,
 281                     "IPv4 ESP input: packet too short\n"));
 282                 ipsecstat.in_inval++;
 283                 goto bad;
 284         }
 285
 286         if (m->m_len < off + esplen + ivlen) {
 287                 m = m_pullup(m, off + esplen + ivlen);
 288                 if (!m) {
 289                         ipseclog((LOG_DEBUG,
 290                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 291                         ipsecstat.in_inval++;
 292                         goto bad;
 293                 }
 294         }
 295
 296         /*
 297          * pre-compute and cache intermediate key
 298          */
 299         if (esp_schedule(algo, sav) != 0) {
 300                 ipsecstat.in_inval++;
 301                 goto bad;
 302         }
 303
 304         /*
 305          * decrypt the packet.
 306          */
 307         if (!algo->decrypt)
 308                 panic("internal error: no decrypt function");
 309         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 310                 /* m is already freed */
 311                 m = NULL;
 312                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 313                     ipsec_logsastr(sav)));
 314                 ipsecstat.in_inval++;
 315                 goto bad;
 316         }
 317         ipsecstat.in_esphist[sav->alg_enc]++;
 318
 319         m->m_flags |= M_DECRYPTED;
 320
 321         /*
 322          * find the trailer of the ESP.
 323          */
 324         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 325              (caddr_t)&esptail);
 326         nxt = esptail.esp_nxt;
 327         taillen = esptail.esp_padlen + sizeof(esptail);
 328
 329         if (m->m_pkthdr.len < taillen
 330          || m->m_pkthdr.len - taillen < hlen) { /*?*/
 331                 ipseclog((LOG_WARNING,
 332                     "bad pad length in IPv4 ESP input: %s %s\n",
 333                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 334                 ipsecstat.in_inval++;
 335                 goto bad;
 336         }
 337
 338         /* strip off the trailing pad area. */
 339         m_adj(m, -taillen);
 340
 341 #ifdef IPLEN_FLIPPED
 342         ip->ip_len = ip->ip_len - taillen;
 343 #else
 344         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 345 #endif
 346
 347         /* was it transmitted over the IPsec tunnel SA? */
 348         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 349                 /*
 350                  * strip off all the headers that precedes ESP header.
 351                  *      IP4 xx ESP IP4' payload -> IP4' payload
 352                  *
 353                  * XXX more sanity checks
 354                  * XXX relationship with gif?
 355                  */
 356                 u_int8_t tos;
 357
 358                 tos = ip->ip_tos;
 359                 m_adj(m, off + esplen + ivlen);
 360                 if (m->m_len < sizeof(*ip)) {
 361                         m = m_pullup(m, sizeof(*ip));
 362                         if (!m) {
 363                                 ipsecstat.in_inval++;
 364                                 goto bad;
 365                         }
 366                 }
 367                 ip = mtod(m, struct ip *);
 368                 /* ECN consideration. */
 369                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 370                 if (!key_checktunnelsanity(sav, AF_INET,
 371                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 372                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 373                             "in IPv4 ESP input: %s %s\n",
 374                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 375                         ipsecstat.in_inval++;
 376                         goto bad;
 377                 }
 378
 379 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 380                 /* drop it if it does not match the default policy */
 381                 if (ipsec4_in_reject(m, NULL)) {
 382                         ipsecstat.in_polvio++;
 383                         goto bad;
 384                 }
 385 #endif
 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 (! IF_HANDOFF(&ipintrq, m, NULL)) {
 395                         ipsecstat.in_inval++;
 396                         m = NULL;
 397                         goto bad;
 398                 }
 399                 m = NULL;
 400                 schednetisr(NETISR_IP); /*can be skipped but to make sure*/
 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) != 0 &&
 434                             ipsec4_in_reject(m, NULL)) {
 435                                 ipsecstat.in_polvio++;
 436                                 goto bad;
 437                         }
 438                         (*inetsw[ip_protox[nxt]].pr_input)(m, off);
 439                 } else
 440                         m_freem(m);
 441                 m = NULL;
 442         }
 443
 444         if (sav) {
 445                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 446                         printf("DP esp4_input call free SA:%p\n", sav));
 447                 key_freesav(sav);
 448         }
 449         ipsecstat.in_success++;
 450         return;
 451
 452 bad:
 453         if (sav) {
 454                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 455                         printf("DP esp4_input call free SA:%p\n", sav));
 456                 key_freesav(sav);
 457         }
 458         if (m)
 459                 m_freem(m);
 460         return;
 461 }
 462 #endif /* INET */
 463
 464 #ifdef INET6
 465 int
 466 esp6_input(mp, offp, proto)
 467         struct mbuf **mp;
 468         int *offp, proto;
 469 {
 470         struct mbuf *m = *mp;
 471         int off = *offp;
 472         struct ip6_hdr *ip6;
 473         struct esp *esp;
 474         struct esptail esptail;
 475         u_int32_t spi;
 476         struct secasvar *sav = NULL;
 477         size_t taillen;
 478         u_int16_t nxt;
 479         const struct esp_algorithm *algo;
 480         int ivlen;
 481         size_t esplen;
 482
 483         /* sanity check for alignment. */
 484         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 485                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 486                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 487                 ipsec6stat.in_inval++;
 488                 goto bad;
 489         }
 490
 491 #ifndef PULLDOWN_TEST
 492         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 493         esp = (struct esp *)(mtod(m, caddr_t) + off);
 494 #else
 495         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 496         if (esp == NULL) {
 497                 ipsec6stat.in_inval++;
 498                 return IPPROTO_DONE;
 499         }
 500 #endif
 501         ip6 = mtod(m, struct ip6_hdr *);
 502
 503         if (ntohs(ip6->ip6_plen) == 0) {
 504                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 505                     "ESP with IPv6 jumbogram is not supported.\n"));
 506                 ipsec6stat.in_inval++;
 507                 goto bad;
 508         }
 509
 510         /* find the sassoc. */
 511         spi = esp->esp_spi;
 512
 513         if ((sav = key_allocsa(AF_INET6,
 514                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 515                               IPPROTO_ESP, spi)) == 0) {
 516                 ipseclog((LOG_WARNING,
 517                     "IPv6 ESP input: no key association found for spi %u\n",
 518                     (u_int32_t)ntohl(spi)));
 519                 ipsec6stat.in_nosa++;
 520                 goto bad;
 521         }
 522         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 523                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 524         if (sav->state != SADB_SASTATE_MATURE
 525          && sav->state != SADB_SASTATE_DYING) {
 526                 ipseclog((LOG_DEBUG,
 527                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 528                     (u_int32_t)ntohl(spi)));
 529                 ipsec6stat.in_badspi++;
 530                 goto bad;
 531         }
 532         algo = esp_algorithm_lookup(sav->alg_enc);
 533         if (!algo) {
 534                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 535                     "unsupported encryption algorithm for spi %u\n",
 536                     (u_int32_t)ntohl(spi)));
 537                 ipsec6stat.in_badspi++;
 538                 goto bad;
 539         }
 540
 541         /* check if we have proper ivlen information */
 542         ivlen = sav->ivlen;
 543         if (ivlen < 0) {
 544                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 545                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 546                 ipsec6stat.in_badspi++;
 547                 goto bad;
 548         }
 549
 550         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 551          && (sav->alg_auth && sav->key_auth)))
 552                 goto noreplaycheck;
 553
 554         if (sav->alg_auth == SADB_X_AALG_NULL ||
 555             sav->alg_auth == SADB_AALG_NONE)
 556                 goto noreplaycheck;
 557
 558         /*
 559          * check for sequence number.
 560          */
 561         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 562                 ; /*okey*/
 563         else {
 564                 ipsec6stat.in_espreplay++;
 565                 ipseclog((LOG_WARNING,
 566                     "replay packet in IPv6 ESP input: %s %s\n",
 567                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 568                 goto bad;
 569         }
 570
 571         /* check ICV */
 572     {
 573         u_char sum0[AH_MAXSUMSIZE];
 574         u_char sum[AH_MAXSUMSIZE];
 575         const struct ah_algorithm *sumalgo;
 576         size_t siz;
 577
 578         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 579         if (!sumalgo)
 580                 goto noreplaycheck;
 581         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 582         if (AH_MAXSUMSIZE < siz) {
 583                 ipseclog((LOG_DEBUG,
 584                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 585                     (u_long)siz));
 586                 ipsec6stat.in_inval++;
 587                 goto bad;
 588         }
 589
 590         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 591
 592         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 593                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 594                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 595                 ipsec6stat.in_espauthfail++;
 596                 goto bad;
 597         }
 598
 599         if (bcmp(sum0, sum, siz) != 0) {
 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         /* strip off the authentication data */
 607         m_adj(m, -siz);
 608         ip6 = mtod(m, struct ip6_hdr *);
 609         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 610
 611         m->m_flags |= M_AUTHIPDGM;
 612         ipsec6stat.in_espauthsucc++;
 613     }
 614
 615         /*
 616          * update sequence number.
 617          */
 618         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 619                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 620                         ipsec6stat.in_espreplay++;
 621                         goto bad;
 622                 }
 623         }
 624
 625 noreplaycheck:
 626
 627         /* process main esp header. */
 628         if (sav->flags & SADB_X_EXT_OLD) {
 629                 /* RFC 1827 */
 630                 esplen = sizeof(struct esp);
 631         } else {
 632                 /* RFC 2406 */
 633                 if (sav->flags & SADB_X_EXT_DERIV)
 634                         esplen = sizeof(struct esp);
 635                 else
 636                         esplen = sizeof(struct newesp);
 637         }
 638
 639         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 640                 ipseclog((LOG_WARNING,
 641                     "IPv6 ESP input: packet too short\n"));
 642                 ipsec6stat.in_inval++;
 643                 goto bad;
 644         }
 645
 646 #ifndef PULLDOWN_TEST
 647         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /*XXX*/
 648 #else
 649         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 650         if (esp == NULL) {
 651                 ipsec6stat.in_inval++;
 652                 m = NULL;
 653                 goto bad;
 654         }
 655 #endif
 656         ip6 = mtod(m, struct ip6_hdr *);        /*set it again just in case*/
 657
 658         /*
 659          * pre-compute and cache intermediate key
 660          */
 661         if (esp_schedule(algo, sav) != 0) {
 662                 ipsec6stat.in_inval++;
 663                 goto bad;
 664         }
 665
 666         /*
 667          * decrypt the packet.
 668          */
 669         if (!algo->decrypt)
 670                 panic("internal error: no decrypt function");
 671         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 672                 /* m is already freed */
 673                 m = NULL;
 674                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 675                     ipsec_logsastr(sav)));
 676                 ipsec6stat.in_inval++;
 677                 goto bad;
 678         }
 679         ipsec6stat.in_esphist[sav->alg_enc]++;
 680
 681         m->m_flags |= M_DECRYPTED;
 682
 683         /*
 684          * find the trailer of the ESP.
 685          */
 686         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 687              (caddr_t)&esptail);
 688         nxt = esptail.esp_nxt;
 689         taillen = esptail.esp_padlen + sizeof(esptail);
 690
 691         if (m->m_pkthdr.len < taillen
 692          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /*?*/
 693                 ipseclog((LOG_WARNING,
 694                     "bad pad length in IPv6 ESP input: %s %s\n",
 695                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 696                 ipsec6stat.in_inval++;
 697                 goto bad;
 698         }
 699
 700         /* strip off the trailing pad area. */
 701         m_adj(m, -taillen);
 702
 703         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 704
 705         /* was it transmitted over the IPsec tunnel SA? */
 706         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 707                 /*
 708                  * strip off all the headers that precedes ESP header.
 709                  *      IP6 xx ESP IP6' payload -> IP6' payload
 710                  *
 711                  * XXX more sanity checks
 712                  * XXX relationship with gif?
 713                  */
 714                 u_int32_t flowinfo;     /*net endian*/
 715                 flowinfo = ip6->ip6_flow;
 716                 m_adj(m, off + esplen + ivlen);
 717                 if (m->m_len < sizeof(*ip6)) {
 718 #ifndef PULLDOWN_TEST
 719                         /*
 720                          * m_pullup is prohibited in KAME IPv6 input processing
 721                          * but there's no other way!
 722                          */
 723 #else
 724                         /* okay to pullup in m_pulldown style */
 725 #endif
 726                         m = m_pullup(m, sizeof(*ip6));
 727                         if (!m) {
 728                                 ipsec6stat.in_inval++;
 729                                 goto bad;
 730                         }
 731                 }
 732                 ip6 = mtod(m, struct ip6_hdr *);
 733                 /* ECN consideration. */
 734                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 735                 if (!key_checktunnelsanity(sav, AF_INET6,
 736                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 737                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 738                             "in IPv6 ESP input: %s %s\n",
 739                             ipsec6_logpacketstr(ip6, spi),
 740                             ipsec_logsastr(sav)));
 741                         ipsec6stat.in_inval++;
 742                         goto bad;
 743                 }
 744
 745 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 746                 /* drop it if it does not match the default policy */
 747                 if (ipsec6_in_reject(m, NULL)) {
 748                         ipsec6stat.in_polvio++;
 749                         goto bad;
 750                 }
 751 #endif
 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 (! IF_HANDOFF(&ip6intrq, m, NULL)) {
 761                         ipsec6stat.in_inval++;
 762                         m = NULL;
 763                         goto bad;
 764                 }
 765                 m = NULL;
 766                 schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
 767                 nxt = IPPROTO_DONE;
 768         } else {
 769                 /*
 770                  * strip off ESP header and IV.
 771                  * even in m_pulldown case, we need to strip off ESP so that
 772                  * we can always compute checksum for AH correctly.
 773                  */
 774                 size_t stripsiz;
 775                 char *prvnxtp;
 776
 777                 /*
 778                  * Set the next header field of the previous header correctly.
 779                  */
 780                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 781                 *prvnxtp = nxt;
 782
 783                 stripsiz = esplen + ivlen;
 784
 785                 ip6 = mtod(m, struct ip6_hdr *);
 786                 if (m->m_len >= stripsiz + off) {
 787                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 788                         m->m_data += stripsiz;
 789                         m->m_len -= stripsiz;
 790                         m->m_pkthdr.len -= stripsiz;
 791                 } else {
 792                         /*
 793                          * this comes with no copy if the boundary is on
 794                          * cluster
 795                          */
 796                         struct mbuf *n;
 797
 798                         n = m_split(m, off, M_DONTWAIT);
 799                         if (n == NULL) {
 800                                 /* m is retained by m_split */
 801                                 goto bad;
 802                         }
 803                         m_adj(n, stripsiz);
 804                         m_cat(m, n);
 805                         /* m_cat does not update m_pkthdr.len */
 806                         m->m_pkthdr.len += n->m_pkthdr.len;
 807                 }
 808
 809 #ifndef PULLDOWN_TEST
 810                 /*
 811                  * KAME requires that the packet to be contiguous on the
 812                  * mbuf.  We need to make that sure.
 813                  * this kind of code should be avoided.
 814                  * XXX other conditions to avoid running this part?
 815                  */
 816                 if (m->m_len != m->m_pkthdr.len) {
 817                         struct mbuf *n = NULL;
 818                         int maxlen;
 819
 820                         MGETHDR(n, M_DONTWAIT, MT_HEADER);
 821                         maxlen = MHLEN;
 822                         if (n)
 823                                 M_COPY_PKTHDR(n, m);
 824                         if (n && m->m_pkthdr.len > maxlen) {
 825                                 MCLGET(n, M_DONTWAIT);
 826                                 maxlen = MCLBYTES;
 827                                 if ((n->m_flags & M_EXT) == 0) {
 828                                         m_free(n);
 829                                         n = NULL;
 830                                 }
 831                         }
 832                         if (!n) {
 833                                 printf("esp6_input: mbuf allocation failed\n");
 834                                 goto bad;
 835                         }
 836
 837                         if (m->m_pkthdr.len <= maxlen) {
 838                                 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
 839                                 n->m_len = m->m_pkthdr.len;
 840                                 n->m_pkthdr.len = m->m_pkthdr.len;
 841                                 n->m_next = NULL;
 842                                 m_freem(m);
 843                         } else {
 844                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 845                                 m_adj(m, maxlen);
 846                                 n->m_len = maxlen;
 847                                 n->m_pkthdr.len = m->m_pkthdr.len;
 848                                 n->m_next = m;
 849                                 m->m_flags &= ~M_PKTHDR;
 850                         }
 851                         m = n;
 852                 }
 853 #endif
 854
 855                 ip6 = mtod(m, struct ip6_hdr *);
 856                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 857
 858                 key_sa_recordxfer(sav, m);
 859                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 860                         ipsec6stat.in_nomem++;
 861                         goto bad;
 862                 }
 863         }
 864
 865         *offp = off;
 866         *mp = m;
 867
 868         if (sav) {
 869                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 870                         printf("DP esp6_input call free SA:%p\n", sav));
 871                 key_freesav(sav);
 872         }
 873         ipsec6stat.in_success++;
 874         return nxt;
 875
 876 bad:
 877         if (sav) {
 878                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 879                         printf("DP esp6_input call free SA:%p\n", sav));
 880                 key_freesav(sav);
 881         }
 882         if (m)
 883                 m_freem(m);
 884         return IPPROTO_DONE;
 885 }
 886
 887 void
 888 esp6_ctlinput(cmd, sa, d)
 889         int cmd;
 890         struct sockaddr *sa;
 891         void *d;
 892 {
 893         const struct newesp *espp;
 894         struct newesp esp;
 895         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 896         struct secasvar *sav;
 897         struct ip6_hdr *ip6;
 898         struct mbuf *m;
 899         int off;
 900         struct sockaddr_in6 sa6_src, sa6_dst;
 901
 902         if (sa->sa_family != AF_INET6 ||
 903             sa->sa_len != sizeof(struct sockaddr_in6))
 904                 return;
 905         if ((unsigned)cmd >= PRC_NCMDS)
 906                 return;
 907
 908         /* if the parameter is from icmp6, decode it. */
 909         if (d != NULL) {
 910                 ip6cp = (struct ip6ctlparam *)d;
 911                 m = ip6cp->ip6c_m;
 912                 ip6 = ip6cp->ip6c_ip6;
 913                 off = ip6cp->ip6c_off;
 914         } else {
 915                 m = NULL;
 916                 ip6 = NULL;
 917         }
 918
 919         if (ip6) {
 920                 /*
 921                  * Notify the error to all possible sockets via pfctlinput2.
 922                  * Since the upper layer information (such as protocol type,
 923                  * source and destination ports) is embedded in the encrypted
 924                  * data and might have been cut, we can't directly call
 925                  * an upper layer ctlinput function. However, the pcbnotify
 926                  * function will consider source and destination addresses
 927                  * as well as the flow info value, and may be able to find
 928                  * some PCB that should be notified.
 929                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 930                  * no possibility of an infinite loop of function calls,
 931                  * because we don't pass the inner IPv6 header.
 932                  */
 933                 bzero(&ip6cp1, sizeof(ip6cp1));
 934                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 935                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 936
 937                 /*
 938                  * Then go to special cases that need ESP header information.
 939                  * XXX: We assume that when ip6 is non NULL,
 940                  * M and OFF are valid.
 941                  */
 942
 943                 /* check if we can safely examine src and dst ports */
 944                 if (m->m_pkthdr.len < off + sizeof(esp))
 945                         return;
 946
 947                 if (m->m_len < off + sizeof(esp)) {
 948                         /*
 949                          * this should be rare case,
 950                          * so we compromise on this copy...
 951                          */
 952                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 953                         espp = &esp;
 954                 } else
 955                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 956
 957                 if (cmd == PRC_MSGSIZE) {
 958                         int valid = 0;
 959
 960                         /*
 961                          * Check to see if we have a valid SA corresponding to
 962                          * the address in the ICMP message payload.
 963                          */
 964                         sav = key_allocsa(AF_INET6,
 965                                           (caddr_t)&sa6_src.sin6_addr,
 966                                           (caddr_t)&sa6_dst, IPPROTO_ESP,
 967                                           espp->esp_spi);
 968                         if (sav) {
 969                                 if (sav->state == SADB_SASTATE_MATURE ||
 970                                     sav->state == SADB_SASTATE_DYING)
 971                                         valid++;
 972                                 key_freesav(sav);
 973                         }
 974
 975                         /* XXX Further validation? */
 976
 977                         /*
 978                          * Depending on the value of "valid" and routing table
 979                          * size (mtudisc_{hi,lo}wat), we will:
 980                          * - recalcurate the new MTU and create the
 981                          *   corresponding routing entry, or
 982                          * - ignore the MTU change notification.
 983                          */
 984                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 985                 }
 986         } else {
 987                 /* we normally notify any pcb here */
 988         }
 989 }
 990 #endif /* INET6 */