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 /*      $KAME: esp_input.c,v 1.62 2002/01/07 11:39:57 kjc 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 <sys/thread2.h>
  51 #include <sys/msgport2.h>
  52
  53 #include <net/if.h>
  54 #include <net/route.h>
  55 #include <net/netisr.h>
  56 #include <machine/cpu.h>
  57
  58 #include <netinet/in.h>
  59 #include <netinet/in_systm.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/in_var.h>
  63 #include <netinet/ip_ecn.h>
  64 #ifdef INET6
  65 #include <netinet6/ip6_ecn.h>
  66 #endif
  67
  68 #ifdef INET6
  69 #include <netinet/ip6.h>
  70 #include <netinet6/in6_pcb.h>
  71 #include <netinet6/ip6_var.h>
  72 #include <netinet/icmp6.h>
  73 #include <netinet6/ip6protosw.h>
  74 #endif
  75
  76 #include <netinet6/ipsec.h>
  77 #ifdef INET6
  78 #include <netinet6/ipsec6.h>
  79 #endif
  80 #include <netinet6/ah.h>
  81 #ifdef INET6
  82 #include <netinet6/ah6.h>
  83 #endif
  84 #include <netinet6/esp.h>
  85 #ifdef INET6
  86 #include <netinet6/esp6.h>
  87 #endif
  88 #include <netproto/key/key.h>
  89 #include <netproto/key/keydb.h>
  90 #include <netproto/key/key_debug.h>
  91
  92 #include <machine/stdarg.h>
  93
  94 #include <net/net_osdep.h>
  95
  96 #define IPLEN_FLIPPED
  97
  98 #define ESPMAXLEN \
  99         (sizeof(struct esp) < sizeof(struct newesp) \
 100                 ? sizeof(struct newesp) : sizeof(struct esp))
 101
 102 #ifdef INET
 103 extern struct protosw inetsw[];
 104
 105 int
 106 esp4_input(struct mbuf **mp, int *offp, int proto)
 107 {
 108         int off;
 109         struct ip *ip;
 110         struct esp *esp;
 111         struct esptail esptail;
 112         struct mbuf *m;
 113         u_int32_t spi;
 114         struct secasvar *sav = NULL;
 115         size_t taillen;
 116         u_int16_t nxt;
 117         const struct esp_algorithm *algo;
 118         int ivlen;
 119         size_t hlen;
 120         size_t esplen;
 121
 122         off = *offp;
 123         m = *mp;
 124         *mp = NULL;
 125
 126         /* sanity check for alignment. */
 127         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 128                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 129                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 130                 ipsecstat.in_inval++;
 131                 goto bad;
 132         }
 133
 134         if (m->m_len < off + ESPMAXLEN) {
 135                 m = m_pullup(m, off + ESPMAXLEN);
 136                 if (!m) {
 137                         ipseclog((LOG_DEBUG,
 138                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 139                         ipsecstat.in_inval++;
 140                         goto bad;
 141                 }
 142         }
 143
 144         ip = mtod(m, struct ip *);
 145         esp = (struct esp *)(((u_int8_t *)ip) + off);
 146 #ifdef _IP_VHL
 147         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 148 #else
 149         hlen = ip->ip_hl << 2;
 150 #endif
 151
 152         /* find the sassoc. */
 153         spi = esp->esp_spi;
 154
 155         if ((sav = key_allocsa(AF_INET,
 156                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 157                               IPPROTO_ESP, spi)) == NULL) {
 158                 ipseclog((LOG_WARNING,
 159                     "IPv4 ESP input: no key association found for spi %u\n",
 160                     (u_int32_t)ntohl(spi)));
 161                 ipsecstat.in_nosa++;
 162                 goto bad;
 163         }
 164         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 165                 kprintf("DP esp4_input called to allocate SA:%p\n", sav));
 166         if (sav->state != SADB_SASTATE_MATURE
 167          && sav->state != SADB_SASTATE_DYING) {
 168                 ipseclog((LOG_DEBUG,
 169                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 170                     (u_int32_t)ntohl(spi)));
 171                 ipsecstat.in_badspi++;
 172                 goto bad;
 173         }
 174         algo = esp_algorithm_lookup(sav->alg_enc);
 175         if (!algo) {
 176                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 177                     "unsupported encryption algorithm for spi %u\n",
 178                     (u_int32_t)ntohl(spi)));
 179                 ipsecstat.in_badspi++;
 180                 goto bad;
 181         }
 182
 183         /* check if we have proper ivlen information */
 184         ivlen = sav->ivlen;
 185         if (ivlen < 0) {
 186                 ipseclog((LOG_ERR, "improper ivlen in IPv4 ESP input: %s %s\n",
 187                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 188                 ipsecstat.in_inval++;
 189                 goto bad;
 190         }
 191
 192         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 193          && (sav->alg_auth && sav->key_auth)))
 194                 goto noreplaycheck;
 195
 196         if (sav->alg_auth == SADB_X_AALG_NULL ||
 197             sav->alg_auth == SADB_AALG_NONE)
 198                 goto noreplaycheck;
 199
 200         /*
 201          * check for sequence number.
 202          */
 203         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 204                 ; /* okey */
 205         else {
 206                 ipsecstat.in_espreplay++;
 207                 ipseclog((LOG_WARNING,
 208                     "replay packet in IPv4 ESP input: %s %s\n",
 209                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 210                 goto bad;
 211         }
 212
 213         /* check ICV */
 214     {
 215         u_char sum0[AH_MAXSUMSIZE];
 216         u_char sum[AH_MAXSUMSIZE];
 217         const struct ah_algorithm *sumalgo;
 218         size_t siz;
 219
 220         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 221         if (!sumalgo)
 222                 goto noreplaycheck;
 223         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 224         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 225                 ipsecstat.in_inval++;
 226                 goto bad;
 227         }
 228         if (AH_MAXSUMSIZE < siz) {
 229                 ipseclog((LOG_DEBUG,
 230                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 231                     (u_long)siz));
 232                 ipsecstat.in_inval++;
 233                 goto bad;
 234         }
 235
 236         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 237
 238         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 239                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 240                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 241                 ipsecstat.in_espauthfail++;
 242                 goto bad;
 243         }
 244
 245         if (bcmp(sum0, sum, siz) != 0) {
 246                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 247                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 248                 ipsecstat.in_espauthfail++;
 249                 goto bad;
 250         }
 251
 252         /* strip off the authentication data */
 253         m_adj(m, -siz);
 254         ip = mtod(m, struct ip *);
 255 #ifdef IPLEN_FLIPPED
 256         ip->ip_len = ip->ip_len - siz;
 257 #else
 258         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 259 #endif
 260         m->m_flags |= M_AUTHIPDGM;
 261         ipsecstat.in_espauthsucc++;
 262     }
 263
 264         /*
 265          * update sequence number.
 266          */
 267         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 268                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 269                         ipsecstat.in_espreplay++;
 270                         goto bad;
 271                 }
 272         }
 273
 274 noreplaycheck:
 275
 276         /* process main esp header. */
 277         if (sav->flags & SADB_X_EXT_OLD) {
 278                 /* RFC 1827 */
 279                 esplen = sizeof(struct esp);
 280         } else {
 281                 /* RFC 2406 */
 282                 if (sav->flags & SADB_X_EXT_DERIV)
 283                         esplen = sizeof(struct esp);
 284                 else
 285                         esplen = sizeof(struct newesp);
 286         }
 287
 288         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 289                 ipseclog((LOG_WARNING,
 290                     "IPv4 ESP input: packet too short\n"));
 291                 ipsecstat.in_inval++;
 292                 goto bad;
 293         }
 294
 295         if (m->m_len < off + esplen + ivlen) {
 296                 m = m_pullup(m, off + esplen + ivlen);
 297                 if (!m) {
 298                         ipseclog((LOG_DEBUG,
 299                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 300                         ipsecstat.in_inval++;
 301                         goto bad;
 302                 }
 303         }
 304
 305         /*
 306          * pre-compute and cache intermediate key
 307          */
 308         if (esp_schedule(algo, sav) != 0) {
 309                 ipsecstat.in_inval++;
 310                 goto bad;
 311         }
 312
 313         /*
 314          * decrypt the packet.
 315          */
 316         if (!algo->decrypt)
 317                 panic("internal error: no decrypt function");
 318         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 319                 /* m is already freed */
 320                 m = NULL;
 321                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 322                     ipsec_logsastr(sav)));
 323                 ipsecstat.in_inval++;
 324                 goto bad;
 325         }
 326         ipsecstat.in_esphist[sav->alg_enc]++;
 327
 328         m->m_flags |= M_DECRYPTED;
 329
 330         /*
 331          * find the trailer of the ESP.
 332          */
 333         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 334              (caddr_t)&esptail);
 335         nxt = esptail.esp_nxt;
 336         taillen = esptail.esp_padlen + sizeof(esptail);
 337
 338         if (m->m_pkthdr.len < taillen ||
 339             m->m_pkthdr.len - taillen < off + esplen + ivlen + sizeof(esptail)) {
 340                 ipseclog((LOG_WARNING,
 341                     "bad pad length in IPv4 ESP input: %s %s\n",
 342                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 343                 ipsecstat.in_inval++;
 344                 goto bad;
 345         }
 346
 347         /* strip off the trailing pad area. */
 348         m_adj(m, -taillen);
 349
 350 #ifdef IPLEN_FLIPPED
 351         ip->ip_len = ip->ip_len - taillen;
 352 #else
 353         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 354 #endif
 355
 356         /* was it transmitted over the IPsec tunnel SA? */
 357         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 358                 /*
 359                  * strip off all the headers that precedes ESP header.
 360                  *      IP4 xx ESP IP4' payload -> IP4' payload
 361                  *
 362                  * XXX more sanity checks
 363                  * XXX relationship with gif?
 364                  */
 365                 u_int8_t tos;
 366
 367                 tos = ip->ip_tos;
 368                 m_adj(m, off + esplen + ivlen);
 369                 if (m->m_len < sizeof(*ip)) {
 370                         m = m_pullup(m, sizeof(*ip));
 371                         if (!m) {
 372                                 ipsecstat.in_inval++;
 373                                 goto bad;
 374                         }
 375                 }
 376                 ip = mtod(m, struct ip *);
 377                 /* ECN consideration. */
 378                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 379                 if (!key_checktunnelsanity(sav, AF_INET,
 380                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 381                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 382                             "in IPv4 ESP input: %s %s\n",
 383                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 384                         ipsecstat.in_inval++;
 385                         goto bad;
 386                 }
 387
 388                 key_sa_recordxfer(sav, m);
 389                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 390                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 391                         ipsecstat.in_nomem++;
 392                         goto bad;
 393                 }
 394
 395                 if (netisr_queue(NETISR_IP, m)) {
 396                         ipsecstat.in_inval++;
 397                         m = NULL;
 398                         goto bad;
 399                 }
 400
 401                 nxt = IPPROTO_DONE;
 402         } else {
 403                 /*
 404                  * strip off ESP header and IV.
 405                  * even in m_pulldown case, we need to strip off ESP so that
 406                  * we can always compute checksum for AH correctly.
 407                  */
 408                 size_t stripsiz;
 409
 410                 stripsiz = esplen + ivlen;
 411
 412                 ip = mtod(m, struct ip *);
 413                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 414                 m->m_data += stripsiz;
 415                 m->m_len -= stripsiz;
 416                 m->m_pkthdr.len -= stripsiz;
 417
 418                 ip = mtod(m, struct ip *);
 419 #ifdef IPLEN_FLIPPED
 420                 ip->ip_len = ip->ip_len - stripsiz;
 421 #else
 422                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 423 #endif
 424                 ip->ip_p = nxt;
 425
 426                 key_sa_recordxfer(sav, m);
 427                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 428                         ipsecstat.in_nomem++;
 429                         goto bad;
 430                 }
 431
 432                 if (nxt != IPPROTO_DONE) {
 433                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 434                             ipsec4_in_reject(m, NULL)) {
 435                                 ipsecstat.in_polvio++;
 436                                 goto bad;
 437                         }
 438                         if (!ip_lengthcheck(&m, 0)) {
 439                                 /* freed in ip_lengthcheck() */
 440                                 goto bad;
 441                         }
 442                         *mp = m;
 443                         *offp = off;
 444                         (*inetsw[ip_protox[nxt]].pr_input)(mp, offp, nxt);
 445                 } else {
 446                         m_freem(m);
 447                 }
 448                 m = NULL;
 449         }
 450
 451         if (sav) {
 452                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 453                         kprintf("DP esp4_input call free SA:%p\n", sav));
 454                 key_freesav(sav);
 455         }
 456         ipsecstat.in_success++;
 457         return(IPPROTO_DONE);
 458
 459 bad:
 460         if (sav) {
 461                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 462                         kprintf("DP esp4_input call free SA:%p\n", sav));
 463                 key_freesav(sav);
 464         }
 465         if (m)
 466                 m_freem(m);
 467         return(IPPROTO_DONE);
 468 }
 469 #endif /* INET */
 470
 471 #ifdef INET6
 472 int
 473 esp6_input(struct mbuf **mp, int *offp, int proto)
 474 {
 475         struct mbuf *m = *mp;
 476         int off = *offp;
 477         struct ip6_hdr *ip6;
 478         struct esp *esp;
 479         struct esptail esptail;
 480         u_int32_t spi;
 481         struct secasvar *sav = NULL;
 482         size_t taillen;
 483         u_int16_t nxt;
 484         const struct esp_algorithm *algo;
 485         int ivlen;
 486         size_t esplen;
 487
 488         /* sanity check for alignment. */
 489         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 490                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 491                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 492                 ipsec6stat.in_inval++;
 493                 goto bad;
 494         }
 495
 496 #ifndef PULLDOWN_TEST
 497         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 498         esp = (struct esp *)(mtod(m, caddr_t) + off);
 499 #else
 500         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 501         if (esp == NULL) {
 502                 ipsec6stat.in_inval++;
 503                 return IPPROTO_DONE;
 504         }
 505 #endif
 506         ip6 = mtod(m, struct ip6_hdr *);
 507
 508         if (ntohs(ip6->ip6_plen) == 0) {
 509                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 510                     "ESP with IPv6 jumbogram is not supported.\n"));
 511                 ipsec6stat.in_inval++;
 512                 goto bad;
 513         }
 514
 515         /* find the sassoc. */
 516         spi = esp->esp_spi;
 517
 518         if ((sav = key_allocsa(AF_INET6,
 519                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 520                               IPPROTO_ESP, spi)) == NULL) {
 521                 ipseclog((LOG_WARNING,
 522                     "IPv6 ESP input: no key association found for spi %u\n",
 523                     (u_int32_t)ntohl(spi)));
 524                 ipsec6stat.in_nosa++;
 525                 goto bad;
 526         }
 527         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 528                 kprintf("DP esp6_input called to allocate SA:%p\n", sav));
 529         if (sav->state != SADB_SASTATE_MATURE
 530          && sav->state != SADB_SASTATE_DYING) {
 531                 ipseclog((LOG_DEBUG,
 532                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 533                     (u_int32_t)ntohl(spi)));
 534                 ipsec6stat.in_badspi++;
 535                 goto bad;
 536         }
 537         algo = esp_algorithm_lookup(sav->alg_enc);
 538         if (!algo) {
 539                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 540                     "unsupported encryption algorithm for spi %u\n",
 541                     (u_int32_t)ntohl(spi)));
 542                 ipsec6stat.in_badspi++;
 543                 goto bad;
 544         }
 545
 546         /* check if we have proper ivlen information */
 547         ivlen = sav->ivlen;
 548         if (ivlen < 0) {
 549                 ipseclog((LOG_ERR, "improper ivlen in IPv6 ESP input: %s %s\n",
 550                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 551                 ipsec6stat.in_badspi++;
 552                 goto bad;
 553         }
 554
 555         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 556          && (sav->alg_auth && sav->key_auth)))
 557                 goto noreplaycheck;
 558
 559         if (sav->alg_auth == SADB_X_AALG_NULL ||
 560             sav->alg_auth == SADB_AALG_NONE)
 561                 goto noreplaycheck;
 562
 563         /*
 564          * check for sequence number.
 565          */
 566         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 567                 ; /* okey */
 568         else {
 569                 ipsec6stat.in_espreplay++;
 570                 ipseclog((LOG_WARNING,
 571                     "replay packet in IPv6 ESP input: %s %s\n",
 572                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 573                 goto bad;
 574         }
 575
 576         /* check ICV */
 577     {
 578         u_char sum0[AH_MAXSUMSIZE];
 579         u_char sum[AH_MAXSUMSIZE];
 580         const struct ah_algorithm *sumalgo;
 581         size_t siz;
 582
 583         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 584         if (!sumalgo)
 585                 goto noreplaycheck;
 586         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 587         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 588                 ipsec6stat.in_inval++;
 589                 goto bad;
 590         }
 591         if (AH_MAXSUMSIZE < siz) {
 592                 ipseclog((LOG_DEBUG,
 593                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 594                     (u_long)siz));
 595                 ipsec6stat.in_inval++;
 596                 goto bad;
 597         }
 598
 599         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 600
 601         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 602                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 603                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 604                 ipsec6stat.in_espauthfail++;
 605                 goto bad;
 606         }
 607
 608         if (bcmp(sum0, sum, siz) != 0) {
 609                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 610                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 611                 ipsec6stat.in_espauthfail++;
 612                 goto bad;
 613         }
 614
 615         /* strip off the authentication data */
 616         m_adj(m, -siz);
 617         ip6 = mtod(m, struct ip6_hdr *);
 618         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 619
 620         m->m_flags |= M_AUTHIPDGM;
 621         ipsec6stat.in_espauthsucc++;
 622     }
 623
 624         /*
 625          * update sequence number.
 626          */
 627         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 628                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 629                         ipsec6stat.in_espreplay++;
 630                         goto bad;
 631                 }
 632         }
 633
 634 noreplaycheck:
 635
 636         /* process main esp header. */
 637         if (sav->flags & SADB_X_EXT_OLD) {
 638                 /* RFC 1827 */
 639                 esplen = sizeof(struct esp);
 640         } else {
 641                 /* RFC 2406 */
 642                 if (sav->flags & SADB_X_EXT_DERIV)
 643                         esplen = sizeof(struct esp);
 644                 else
 645                         esplen = sizeof(struct newesp);
 646         }
 647
 648         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 649                 ipseclog((LOG_WARNING,
 650                     "IPv6 ESP input: packet too short\n"));
 651                 ipsec6stat.in_inval++;
 652                 goto bad;
 653         }
 654
 655 #ifndef PULLDOWN_TEST
 656         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 657 #else
 658         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 659         if (esp == NULL) {
 660                 ipsec6stat.in_inval++;
 661                 m = NULL;
 662                 goto bad;
 663         }
 664 #endif
 665         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 666
 667         /*
 668          * pre-compute and cache intermediate key
 669          */
 670         if (esp_schedule(algo, sav) != 0) {
 671                 ipsec6stat.in_inval++;
 672                 goto bad;
 673         }
 674
 675         /*
 676          * decrypt the packet.
 677          */
 678         if (!algo->decrypt)
 679                 panic("internal error: no decrypt function");
 680         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 681                 /* m is already freed */
 682                 m = NULL;
 683                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 684                     ipsec_logsastr(sav)));
 685                 ipsec6stat.in_inval++;
 686                 goto bad;
 687         }
 688         ipsec6stat.in_esphist[sav->alg_enc]++;
 689
 690         m->m_flags |= M_DECRYPTED;
 691
 692         /*
 693          * find the trailer of the ESP.
 694          */
 695         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 696              (caddr_t)&esptail);
 697         nxt = esptail.esp_nxt;
 698         taillen = esptail.esp_padlen + sizeof(esptail);
 699
 700         if (m->m_pkthdr.len < taillen
 701          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 702                 ipseclog((LOG_WARNING,
 703                     "bad pad length in IPv6 ESP input: %s %s\n",
 704                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 705                 ipsec6stat.in_inval++;
 706                 goto bad;
 707         }
 708
 709         /* strip off the trailing pad area. */
 710         m_adj(m, -taillen);
 711
 712         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 713
 714         /* was it transmitted over the IPsec tunnel SA? */
 715         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 716                 /*
 717                  * strip off all the headers that precedes ESP header.
 718                  *      IP6 xx ESP IP6' payload -> IP6' payload
 719                  *
 720                  * XXX more sanity checks
 721                  * XXX relationship with gif?
 722                  */
 723                 u_int32_t flowinfo;     /* net endian */
 724                 flowinfo = ip6->ip6_flow;
 725                 m_adj(m, off + esplen + ivlen);
 726                 if (m->m_len < sizeof(*ip6)) {
 727 #ifndef PULLDOWN_TEST
 728                         /*
 729                          * m_pullup is prohibited in KAME IPv6 input processing
 730                          * but there's no other way!
 731                          */
 732 #else
 733                         /* okay to pullup in m_pulldown style */
 734 #endif
 735                         m = m_pullup(m, sizeof(*ip6));
 736                         if (!m) {
 737                                 ipsec6stat.in_inval++;
 738                                 goto bad;
 739                         }
 740                 }
 741                 ip6 = mtod(m, struct ip6_hdr *);
 742                 /* ECN consideration. */
 743                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 744                 if (!key_checktunnelsanity(sav, AF_INET6,
 745                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 746                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 747                             "in IPv6 ESP input: %s %s\n",
 748                             ipsec6_logpacketstr(ip6, spi),
 749                             ipsec_logsastr(sav)));
 750                         ipsec6stat.in_inval++;
 751                         goto bad;
 752                 }
 753
 754                 key_sa_recordxfer(sav, m);
 755                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 756                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 757                         ipsec6stat.in_nomem++;
 758                         goto bad;
 759                 }
 760
 761                 if (netisr_queue(NETISR_IPV6, m)) {
 762                         ipsec6stat.in_inval++;
 763                         m = NULL;
 764                         goto bad;
 765                 }
 766
 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, MB_DONTWAIT);
 799                         if (n == NULL) {
 800                                 /* m is retained by m_split */
 801                                 goto bad;
 802                         }
 803                         m_adj(n, stripsiz);
 804                         /* m_cat does not update m_pkthdr.len */
 805                         m->m_pkthdr.len += n->m_pkthdr.len;
 806                         m_cat(m, n);
 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                         n = m_getb(m->m_pkthdr.len, MB_DONTWAIT, MT_HEADER,
 821                                    M_PKTHDR);
 822                         if (!n) {
 823                                 kprintf("esp6_input: mbuf allocation failed\n");
 824                                 goto bad;
 825                         }
 826                         M_MOVE_PKTHDR(n, m);
 827
 828                         maxlen = (n->m_flags & M_EXT) ? MCLBYTES : MHLEN;
 829                         if (n->m_pkthdr.len <= maxlen) {
 830                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
 831                                 n->m_len = n->m_pkthdr.len;
 832                                 n->m_next = NULL;
 833                                 m_freem(m);
 834                         } else {
 835                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 836                                 n->m_len = maxlen;
 837                                 n->m_next = m;
 838                                 m_adj(m, maxlen);
 839                         }
 840                         m = n;
 841                 }
 842 #endif
 843
 844                 ip6 = mtod(m, struct ip6_hdr *);
 845                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 846
 847                 key_sa_recordxfer(sav, m);
 848                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 849                         ipsec6stat.in_nomem++;
 850                         goto bad;
 851                 }
 852         }
 853
 854         *offp = off;
 855         *mp = m;
 856
 857         if (sav) {
 858                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 859                         kprintf("DP esp6_input call free SA:%p\n", sav));
 860                 key_freesav(sav);
 861         }
 862         ipsec6stat.in_success++;
 863         return nxt;
 864
 865 bad:
 866         if (sav) {
 867                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 868                         kprintf("DP esp6_input call free SA:%p\n", sav));
 869                 key_freesav(sav);
 870         }
 871         if (m)
 872                 m_freem(m);
 873         return IPPROTO_DONE;
 874 }
 875
 876 void
 877 esp6_ctlinput(netmsg_t msg)
 878 {
 879         int cmd = msg->ctlinput.nm_cmd;
 880         struct sockaddr *sa = msg->ctlinput.nm_arg;
 881         void *d = msg->ctlinput.nm_extra;
 882         const struct newesp *espp;
 883         struct newesp esp;
 884         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 885         struct secasvar *sav;
 886         struct ip6_hdr *ip6;
 887         struct mbuf *m;
 888         int off;
 889         struct sockaddr_in6 *sa6_src, *sa6_dst;
 890
 891         if (sa->sa_family != AF_INET6 ||
 892             sa->sa_len != sizeof(struct sockaddr_in6))
 893                 goto out;
 894         if ((unsigned)cmd >= PRC_NCMDS)
 895                 goto out;
 896
 897         /* if the parameter is from icmp6, decode it. */
 898         if (d != NULL) {
 899                 ip6cp = (struct ip6ctlparam *)d;
 900                 m = ip6cp->ip6c_m;
 901                 ip6 = ip6cp->ip6c_ip6;
 902                 off = ip6cp->ip6c_off;
 903         } else {
 904                 m = NULL;
 905                 ip6 = NULL;
 906                 off = 0; /* fix warning */
 907         }
 908
 909         if (ip6) {
 910                 /*
 911                  * Notify the error to all possible sockets via pfctlinput2.
 912                  * Since the upper layer information (such as protocol type,
 913                  * source and destination ports) is embedded in the encrypted
 914                  * data and might have been cut, we can't directly call
 915                  * an upper layer ctlinput function. However, the pcbnotify
 916                  * function will consider source and destination addresses
 917                  * as well as the flow info value, and may be able to find
 918                  * some PCB that should be notified.
 919                  * Although kpfctlinput2 will call esp6_ctlinput(), there is
 920                  * no possibility of an infinite loop of function calls,
 921                  * because we don't pass the inner IPv6 header.
 922                  */
 923                 bzero(&ip6cp1, sizeof(ip6cp1));
 924                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 925                 kpfctlinput2(cmd, sa, (void *)&ip6cp1);
 926
 927                 /*
 928                  * Then go to special cases that need ESP header information.
 929                  * XXX: We assume that when ip6 is non NULL,
 930                  * M and OFF are valid.
 931                  */
 932
 933                 /* check if we can safely examine src and dst ports */
 934                 if (m->m_pkthdr.len < off + sizeof(esp))
 935                         goto out;
 936
 937                 if (m->m_len < off + sizeof(esp)) {
 938                         /*
 939                          * this should be rare case,
 940                          * so we compromise on this copy...
 941                          */
 942                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 943                         espp = &esp;
 944                 } else
 945                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 946
 947                 if (cmd == PRC_MSGSIZE) {
 948                         int valid = 0;
 949
 950                         /*
 951                          * Check to see if we have a valid SA corresponding to
 952                          * the address in the ICMP message payload.
 953                          */
 954                         sa6_src = ip6cp->ip6c_src;
 955                         sa6_dst = (struct sockaddr_in6 *)sa;
 956                         sav = key_allocsa(AF_INET6,
 957                                           (caddr_t)&sa6_src->sin6_addr,
 958                                           (caddr_t)&sa6_dst->sin6_addr,
 959                                           IPPROTO_ESP, espp->esp_spi);
 960                         if (sav) {
 961                                 if (sav->state == SADB_SASTATE_MATURE ||
 962                                     sav->state == SADB_SASTATE_DYING)
 963                                         valid++;
 964                                 key_freesav(sav);
 965                         }
 966
 967                         /* XXX Further validation? */
 968
 969                         /*
 970                          * Depending on the value of "valid" and routing table
 971                          * size (mtudisc_{hi,lo}wat), we will:
 972                          * - recalcurate the new MTU and create the
 973                          *   corresponding routing entry, or
 974                          * - ignore the MTU change notification.
 975                          */
 976                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 977                 }
 978         } else {
 979                 /* we normally notify any pcb here */
 980         }
 981 out:
 982         lwkt_replymsg(&msg->ctlinput.base.lmsg, 0);
 983 }
 984 #endif /* INET6 */