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 1.3 2003/07/23 02:30:22 dillon Exp $ */
   3 /*      $KAME: esp_input.c,v 1.62 2002/01/07 11:39:57 kjc Exp $ */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * RFC1827/2406 Encapsulated Security Payload.
  36  */
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/mbuf.h>
  44 #include <sys/domain.h>
  45 #include <sys/protosw.h>
  46 #include <sys/socket.h>
  47 #include <sys/errno.h>
  48 #include <sys/time.h>
  49 #include <sys/syslog.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53 #include <net/netisr.h>
  54 #include <machine/cpu.h>
  55
  56 #include <netinet/in.h>
  57 #include <netinet/in_systm.h>
  58 #include <netinet/ip.h>
  59 #include <netinet/ip_var.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip_ecn.h>
  62 #ifdef INET6
  63 #include <netinet6/ip6_ecn.h>
  64 #endif
  65
  66 #ifdef INET6
  67 #include <netinet/ip6.h>
  68 #include <netinet6/in6_pcb.h>
  69 #include <netinet6/ip6_var.h>
  70 #include <netinet/icmp6.h>
  71 #include <netinet6/ip6protosw.h>
  72 #endif
  73
  74 #include <netinet6/ipsec.h>
  75 #ifdef INET6
  76 #include <netinet6/ipsec6.h>
  77 #endif
  78 #include <netinet6/ah.h>
  79 #ifdef INET6
  80 #include <netinet6/ah6.h>
  81 #endif
  82 #include <netinet6/esp.h>
  83 #ifdef INET6
  84 #include <netinet6/esp6.h>
  85 #endif
  86 #include <netkey/key.h>
  87 #include <netkey/keydb.h>
  88 #include <netkey/key_debug.h>
  89
  90 #include <machine/stdarg.h>
  91
  92 #include <net/net_osdep.h>
  93
  94 #define IPLEN_FLIPPED
  95
  96 #define ESPMAXLEN \
  97         (sizeof(struct esp) < sizeof(struct newesp) \
  98                 ? sizeof(struct newesp) : sizeof(struct esp))
  99
 100 #ifdef INET
 101 #include <netinet/ipprotosw.h>
 102 extern struct ipprotosw inetsw[];
 103
 104 void
 105 esp4_input(struct mbuf *m, int off, int proto)
 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 s;
 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         esp = (struct esp *)(((u_int8_t *)ip) + off);
 140 #ifdef _IP_VHL
 141         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 142 #else
 143         hlen = ip->ip_hl << 2;
 144 #endif
 145
 146         /* find the sassoc. */
 147         spi = esp->esp_spi;
 148
 149         if ((sav = key_allocsa(AF_INET,
 150                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 151                               IPPROTO_ESP, spi)) == 0) {
 152                 ipseclog((LOG_WARNING,
 153                     "IPv4 ESP input: no key association found for spi %u\n",
 154                     (u_int32_t)ntohl(spi)));
 155                 ipsecstat.in_nosa++;
 156                 goto bad;
 157         }
 158         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 159                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 160         if (sav->state != SADB_SASTATE_MATURE
 161          && sav->state != SADB_SASTATE_DYING) {
 162                 ipseclog((LOG_DEBUG,
 163                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 164                     (u_int32_t)ntohl(spi)));
 165                 ipsecstat.in_badspi++;
 166                 goto bad;
 167         }
 168         algo = esp_algorithm_lookup(sav->alg_enc);
 169         if (!algo) {
 170                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 171                     "unsupported encryption algorithm for spi %u\n",
 172                     (u_int32_t)ntohl(spi)));
 173                 ipsecstat.in_badspi++;
 174                 goto bad;
 175         }
 176
 177         /* check if we have proper ivlen information */
 178         ivlen = sav->ivlen;
 179         if (ivlen < 0) {
 180                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 181                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 182                 ipsecstat.in_inval++;
 183                 goto bad;
 184         }
 185
 186         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 187          && (sav->alg_auth && sav->key_auth)))
 188                 goto noreplaycheck;
 189
 190         if (sav->alg_auth == SADB_X_AALG_NULL ||
 191             sav->alg_auth == SADB_AALG_NONE)
 192                 goto noreplaycheck;
 193
 194         /*
 195          * check for sequence number.
 196          */
 197         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 198                 ; /* okey */
 199         else {
 200                 ipsecstat.in_espreplay++;
 201                 ipseclog((LOG_WARNING,
 202                     "replay packet in IPv4 ESP input: %s %s\n",
 203                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 204                 goto bad;
 205         }
 206
 207         /* check ICV */
 208     {
 209         u_char sum0[AH_MAXSUMSIZE];
 210         u_char sum[AH_MAXSUMSIZE];
 211         const struct ah_algorithm *sumalgo;
 212         size_t siz;
 213
 214         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 215         if (!sumalgo)
 216                 goto noreplaycheck;
 217         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 218         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 219                 ipsecstat.in_inval++;
 220                 goto bad;
 221         }
 222         if (AH_MAXSUMSIZE < siz) {
 223                 ipseclog((LOG_DEBUG,
 224                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 225                     (u_long)siz));
 226                 ipsecstat.in_inval++;
 227                 goto bad;
 228         }
 229
 230         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 231
 232         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 233                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 234                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 235                 ipsecstat.in_espauthfail++;
 236                 goto bad;
 237         }
 238
 239         if (bcmp(sum0, sum, siz) != 0) {
 240                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 241                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 242                 ipsecstat.in_espauthfail++;
 243                 goto bad;
 244         }
 245
 246         /* strip off the authentication data */
 247         m_adj(m, -siz);
 248         ip = mtod(m, struct ip *);
 249 #ifdef IPLEN_FLIPPED
 250         ip->ip_len = ip->ip_len - siz;
 251 #else
 252         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 253 #endif
 254         m->m_flags |= M_AUTHIPDGM;
 255         ipsecstat.in_espauthsucc++;
 256     }
 257
 258         /*
 259          * update sequence number.
 260          */
 261         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 262                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 263                         ipsecstat.in_espreplay++;
 264                         goto bad;
 265                 }
 266         }
 267
 268 noreplaycheck:
 269
 270         /* process main esp header. */
 271         if (sav->flags & SADB_X_EXT_OLD) {
 272                 /* RFC 1827 */
 273                 esplen = sizeof(struct esp);
 274         } else {
 275                 /* RFC 2406 */
 276                 if (sav->flags & SADB_X_EXT_DERIV)
 277                         esplen = sizeof(struct esp);
 278                 else
 279                         esplen = sizeof(struct newesp);
 280         }
 281
 282         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 283                 ipseclog((LOG_WARNING,
 284                     "IPv4 ESP input: packet too short\n"));
 285                 ipsecstat.in_inval++;
 286                 goto bad;
 287         }
 288
 289         if (m->m_len < off + esplen + ivlen) {
 290                 m = m_pullup(m, off + esplen + ivlen);
 291                 if (!m) {
 292                         ipseclog((LOG_DEBUG,
 293                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 294                         ipsecstat.in_inval++;
 295                         goto bad;
 296                 }
 297         }
 298
 299         /*
 300          * pre-compute and cache intermediate key
 301          */
 302         if (esp_schedule(algo, sav) != 0) {
 303                 ipsecstat.in_inval++;
 304                 goto bad;
 305         }
 306
 307         /*
 308          * decrypt the packet.
 309          */
 310         if (!algo->decrypt)
 311                 panic("internal error: no decrypt function");
 312         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 313                 /* m is already freed */
 314                 m = NULL;
 315                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 316                     ipsec_logsastr(sav)));
 317                 ipsecstat.in_inval++;
 318                 goto bad;
 319         }
 320         ipsecstat.in_esphist[sav->alg_enc]++;
 321
 322         m->m_flags |= M_DECRYPTED;
 323
 324         /*
 325          * find the trailer of the ESP.
 326          */
 327         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 328              (caddr_t)&esptail);
 329         nxt = esptail.esp_nxt;
 330         taillen = esptail.esp_padlen + sizeof(esptail);
 331
 332         if (m->m_pkthdr.len < taillen
 333          || m->m_pkthdr.len - taillen < hlen) { /* ? */
 334                 ipseclog((LOG_WARNING,
 335                     "bad pad length in IPv4 ESP input: %s %s\n",
 336                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 337                 ipsecstat.in_inval++;
 338                 goto bad;
 339         }
 340
 341         /* strip off the trailing pad area. */
 342         m_adj(m, -taillen);
 343
 344 #ifdef IPLEN_FLIPPED
 345         ip->ip_len = ip->ip_len - taillen;
 346 #else
 347         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 348 #endif
 349
 350         /* was it transmitted over the IPsec tunnel SA? */
 351         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 352                 /*
 353                  * strip off all the headers that precedes ESP header.
 354                  *      IP4 xx ESP IP4' payload -> IP4' payload
 355                  *
 356                  * XXX more sanity checks
 357                  * XXX relationship with gif?
 358                  */
 359                 u_int8_t tos;
 360
 361                 tos = ip->ip_tos;
 362                 m_adj(m, off + esplen + ivlen);
 363                 if (m->m_len < sizeof(*ip)) {
 364                         m = m_pullup(m, sizeof(*ip));
 365                         if (!m) {
 366                                 ipsecstat.in_inval++;
 367                                 goto bad;
 368                         }
 369                 }
 370                 ip = mtod(m, struct ip *);
 371                 /* ECN consideration. */
 372                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 373                 if (!key_checktunnelsanity(sav, AF_INET,
 374                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 375                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 376                             "in IPv4 ESP input: %s %s\n",
 377                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 378                         ipsecstat.in_inval++;
 379                         goto bad;
 380                 }
 381
 382                 key_sa_recordxfer(sav, m);
 383                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 384                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 385                         ipsecstat.in_nomem++;
 386                         goto bad;
 387                 }
 388
 389                 s = splimp();
 390                 if (IF_QFULL(&ipintrq)) {
 391                         ipsecstat.in_inval++;
 392                         splx(s);
 393                         goto bad;
 394                 }
 395                 IF_ENQUEUE(&ipintrq, m);
 396                 m = NULL;
 397                 schednetisr(NETISR_IP); /* can be skipped but to make sure */
 398                 splx(s);
 399                 nxt = IPPROTO_DONE;
 400         } else {
 401                 /*
 402                  * strip off ESP header and IV.
 403                  * even in m_pulldown case, we need to strip off ESP so that
 404                  * we can always compute checksum for AH correctly.
 405                  */
 406                 size_t stripsiz;
 407
 408                 stripsiz = esplen + ivlen;
 409
 410                 ip = mtod(m, struct ip *);
 411                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 412                 m->m_data += stripsiz;
 413                 m->m_len -= stripsiz;
 414                 m->m_pkthdr.len -= stripsiz;
 415
 416                 ip = mtod(m, struct ip *);
 417 #ifdef IPLEN_FLIPPED
 418                 ip->ip_len = ip->ip_len - stripsiz;
 419 #else
 420                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 421 #endif
 422                 ip->ip_p = nxt;
 423
 424                 key_sa_recordxfer(sav, m);
 425                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 426                         ipsecstat.in_nomem++;
 427                         goto bad;
 428                 }
 429
 430                 if (nxt != IPPROTO_DONE) {
 431                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 432                             ipsec4_in_reject(m, NULL)) {
 433                                 ipsecstat.in_polvio++;
 434                                 goto bad;
 435                         }
 436                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 437                 } else
 438                         m_freem(m);
 439                 m = NULL;
 440         }
 441
 442         if (sav) {
 443                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 444                         printf("DP esp4_input call free SA:%p\n", sav));
 445                 key_freesav(sav);
 446         }
 447         ipsecstat.in_success++;
 448         return;
 449
 450 bad:
 451         if (sav) {
 452                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 453                         printf("DP esp4_input call free SA:%p\n", sav));
 454                 key_freesav(sav);
 455         }
 456         if (m)
 457                 m_freem(m);
 458         return;
 459 }
 460 #endif /* INET */
 461
 462 #ifdef INET6
 463 int
 464 esp6_input(mp, offp, proto)
 465         struct mbuf **mp;
 466         int *offp, proto;
 467 {
 468         struct mbuf *m = *mp;
 469         int off = *offp;
 470         struct ip6_hdr *ip6;
 471         struct esp *esp;
 472         struct esptail esptail;
 473         u_int32_t spi;
 474         struct secasvar *sav = NULL;
 475         size_t taillen;
 476         u_int16_t nxt;
 477         const struct esp_algorithm *algo;
 478         int ivlen;
 479         size_t esplen;
 480         int s;
 481
 482         /* sanity check for alignment. */
 483         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 484                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 485                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 486                 ipsec6stat.in_inval++;
 487                 goto bad;
 488         }
 489
 490 #ifndef PULLDOWN_TEST
 491         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 492         esp = (struct esp *)(mtod(m, caddr_t) + off);
 493 #else
 494         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 495         if (esp == NULL) {
 496                 ipsec6stat.in_inval++;
 497                 return IPPROTO_DONE;
 498         }
 499 #endif
 500         ip6 = mtod(m, struct ip6_hdr *);
 501
 502         if (ntohs(ip6->ip6_plen) == 0) {
 503                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 504                     "ESP with IPv6 jumbogram is not supported.\n"));
 505                 ipsec6stat.in_inval++;
 506                 goto bad;
 507         }
 508
 509         /* find the sassoc. */
 510         spi = esp->esp_spi;
 511
 512         if ((sav = key_allocsa(AF_INET6,
 513                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 514                               IPPROTO_ESP, spi)) == 0) {
 515                 ipseclog((LOG_WARNING,
 516                     "IPv6 ESP input: no key association found for spi %u\n",
 517                     (u_int32_t)ntohl(spi)));
 518                 ipsec6stat.in_nosa++;
 519                 goto bad;
 520         }
 521         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 522                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 523         if (sav->state != SADB_SASTATE_MATURE
 524          && sav->state != SADB_SASTATE_DYING) {
 525                 ipseclog((LOG_DEBUG,
 526                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 527                     (u_int32_t)ntohl(spi)));
 528                 ipsec6stat.in_badspi++;
 529                 goto bad;
 530         }
 531         algo = esp_algorithm_lookup(sav->alg_enc);
 532         if (!algo) {
 533                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 534                     "unsupported encryption algorithm for spi %u\n",
 535                     (u_int32_t)ntohl(spi)));
 536                 ipsec6stat.in_badspi++;
 537                 goto bad;
 538         }
 539
 540         /* check if we have proper ivlen information */
 541         ivlen = sav->ivlen;
 542         if (ivlen < 0) {
 543                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 544                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 545                 ipsec6stat.in_badspi++;
 546                 goto bad;
 547         }
 548
 549         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 550          && (sav->alg_auth && sav->key_auth)))
 551                 goto noreplaycheck;
 552
 553         if (sav->alg_auth == SADB_X_AALG_NULL ||
 554             sav->alg_auth == SADB_AALG_NONE)
 555                 goto noreplaycheck;
 556
 557         /*
 558          * check for sequence number.
 559          */
 560         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 561                 ; /* okey */
 562         else {
 563                 ipsec6stat.in_espreplay++;
 564                 ipseclog((LOG_WARNING,
 565                     "replay packet in IPv6 ESP input: %s %s\n",
 566                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 567                 goto bad;
 568         }
 569
 570         /* check ICV */
 571     {
 572         u_char sum0[AH_MAXSUMSIZE];
 573         u_char sum[AH_MAXSUMSIZE];
 574         const struct ah_algorithm *sumalgo;
 575         size_t siz;
 576
 577         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 578         if (!sumalgo)
 579                 goto noreplaycheck;
 580         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 581         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
 582                 ipsecstat.in_inval++;
 583                 goto bad;
 584         }
 585         if (AH_MAXSUMSIZE < siz) {
 586                 ipseclog((LOG_DEBUG,
 587                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 588                     (u_long)siz));
 589                 ipsec6stat.in_inval++;
 590                 goto bad;
 591         }
 592
 593         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 594
 595         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 596                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 597                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 598                 ipsec6stat.in_espauthfail++;
 599                 goto bad;
 600         }
 601
 602         if (bcmp(sum0, sum, siz) != 0) {
 603                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 604                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 605                 ipsec6stat.in_espauthfail++;
 606                 goto bad;
 607         }
 608
 609         /* strip off the authentication data */
 610         m_adj(m, -siz);
 611         ip6 = mtod(m, struct ip6_hdr *);
 612         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 613
 614         m->m_flags |= M_AUTHIPDGM;
 615         ipsec6stat.in_espauthsucc++;
 616     }
 617
 618         /*
 619          * update sequence number.
 620          */
 621         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 622                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 623                         ipsec6stat.in_espreplay++;
 624                         goto bad;
 625                 }
 626         }
 627
 628 noreplaycheck:
 629
 630         /* process main esp header. */
 631         if (sav->flags & SADB_X_EXT_OLD) {
 632                 /* RFC 1827 */
 633                 esplen = sizeof(struct esp);
 634         } else {
 635                 /* RFC 2406 */
 636                 if (sav->flags & SADB_X_EXT_DERIV)
 637                         esplen = sizeof(struct esp);
 638                 else
 639                         esplen = sizeof(struct newesp);
 640         }
 641
 642         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 643                 ipseclog((LOG_WARNING,
 644                     "IPv6 ESP input: packet too short\n"));
 645                 ipsec6stat.in_inval++;
 646                 goto bad;
 647         }
 648
 649 #ifndef PULLDOWN_TEST
 650         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
 651 #else
 652         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 653         if (esp == NULL) {
 654                 ipsec6stat.in_inval++;
 655                 m = NULL;
 656                 goto bad;
 657         }
 658 #endif
 659         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
 660
 661         /*
 662          * pre-compute and cache intermediate key
 663          */
 664         if (esp_schedule(algo, sav) != 0) {
 665                 ipsec6stat.in_inval++;
 666                 goto bad;
 667         }
 668
 669         /*
 670          * decrypt the packet.
 671          */
 672         if (!algo->decrypt)
 673                 panic("internal error: no decrypt function");
 674         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 675                 /* m is already freed */
 676                 m = NULL;
 677                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 678                     ipsec_logsastr(sav)));
 679                 ipsec6stat.in_inval++;
 680                 goto bad;
 681         }
 682         ipsec6stat.in_esphist[sav->alg_enc]++;
 683
 684         m->m_flags |= M_DECRYPTED;
 685
 686         /*
 687          * find the trailer of the ESP.
 688          */
 689         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 690              (caddr_t)&esptail);
 691         nxt = esptail.esp_nxt;
 692         taillen = esptail.esp_padlen + sizeof(esptail);
 693
 694         if (m->m_pkthdr.len < taillen
 695          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
 696                 ipseclog((LOG_WARNING,
 697                     "bad pad length in IPv6 ESP input: %s %s\n",
 698                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 699                 ipsec6stat.in_inval++;
 700                 goto bad;
 701         }
 702
 703         /* strip off the trailing pad area. */
 704         m_adj(m, -taillen);
 705
 706         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 707
 708         /* was it transmitted over the IPsec tunnel SA? */
 709         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 710                 /*
 711                  * strip off all the headers that precedes ESP header.
 712                  *      IP6 xx ESP IP6' payload -> IP6' payload
 713                  *
 714                  * XXX more sanity checks
 715                  * XXX relationship with gif?
 716                  */
 717                 u_int32_t flowinfo;     /* net endian */
 718                 flowinfo = ip6->ip6_flow;
 719                 m_adj(m, off + esplen + ivlen);
 720                 if (m->m_len < sizeof(*ip6)) {
 721 #ifndef PULLDOWN_TEST
 722                         /*
 723                          * m_pullup is prohibited in KAME IPv6 input processing
 724                          * but there's no other way!
 725                          */
 726 #else
 727                         /* okay to pullup in m_pulldown style */
 728 #endif
 729                         m = m_pullup(m, sizeof(*ip6));
 730                         if (!m) {
 731                                 ipsec6stat.in_inval++;
 732                                 goto bad;
 733                         }
 734                 }
 735                 ip6 = mtod(m, struct ip6_hdr *);
 736                 /* ECN consideration. */
 737                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 738                 if (!key_checktunnelsanity(sav, AF_INET6,
 739                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 740                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 741                             "in IPv6 ESP input: %s %s\n",
 742                             ipsec6_logpacketstr(ip6, spi),
 743                             ipsec_logsastr(sav)));
 744                         ipsec6stat.in_inval++;
 745                         goto bad;
 746                 }
 747
 748                 key_sa_recordxfer(sav, m);
 749                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 750                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 751                         ipsec6stat.in_nomem++;
 752                         goto bad;
 753                 }
 754
 755                 s = splimp();
 756                 if (IF_QFULL(&ip6intrq)) {
 757                         ipsec6stat.in_inval++;
 758                         splx(s);
 759                         goto bad;
 760                 }
 761                 IF_ENQUEUE(&ip6intrq, m);
 762                 m = NULL;
 763                 schednetisr(NETISR_IPV6); /* can be skipped but to make sure */
 764                 splx(s);
 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, M_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, M_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, M_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 */