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 #include <netinet/ipprotosw.h>
 101 extern struct ipprotosw inetsw[];
 102
 103 void
 104 #if __STDC__
 105 esp4_input(struct mbuf *m, ...)
 106 #else
 107 esp4_input(m, va_alist)
 108         struct mbuf *m;
 109         va_dcl
 110 #endif
 111 {
 112         struct ip *ip;
 113         struct esp *esp;
 114         struct esptail esptail;
 115         u_int32_t spi;
 116         struct secasvar *sav = NULL;
 117         size_t taillen;
 118         u_int16_t nxt;
 119         const struct esp_algorithm *algo;
 120         int ivlen;
 121         size_t hlen;
 122         size_t esplen;
 123         va_list ap;
 124         int off, proto;
 125
 126         va_start(ap, m);
 127         off = va_arg(ap, int);
 128         proto = va_arg(ap, int);
 129         va_end(ap);
 130
 131         /* sanity check for alignment. */
 132         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 133                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
 134                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 135                 ipsecstat.in_inval++;
 136                 goto bad;
 137         }
 138
 139         if (m->m_len < off + ESPMAXLEN) {
 140                 m = m_pullup(m, off + ESPMAXLEN);
 141                 if (!m) {
 142                         ipseclog((LOG_DEBUG,
 143                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 144                         ipsecstat.in_inval++;
 145                         goto bad;
 146                 }
 147         }
 148
 149         ip = mtod(m, struct ip *);
 150         esp = (struct esp *)(((u_int8_t *)ip) + off);
 151 #ifdef _IP_VHL
 152         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 153 #else
 154         hlen = ip->ip_hl << 2;
 155 #endif
 156
 157         /* find the sassoc. */
 158         spi = esp->esp_spi;
 159
 160         if ((sav = key_allocsa(AF_INET,
 161                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 162                               IPPROTO_ESP, spi)) == 0) {
 163                 ipseclog((LOG_WARNING,
 164                     "IPv4 ESP input: no key association found for spi %u\n",
 165                     (u_int32_t)ntohl(spi)));
 166                 ipsecstat.in_nosa++;
 167                 goto bad;
 168         }
 169         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 170                 printf("DP esp4_input called to allocate SA:%p\n", sav));
 171         if (sav->state != SADB_SASTATE_MATURE
 172          && sav->state != SADB_SASTATE_DYING) {
 173                 ipseclog((LOG_DEBUG,
 174                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
 175                     (u_int32_t)ntohl(spi)));
 176                 ipsecstat.in_badspi++;
 177                 goto bad;
 178         }
 179         algo = esp_algorithm_lookup(sav->alg_enc);
 180         if (!algo) {
 181                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
 182                     "unsupported encryption algorithm for spi %u\n",
 183                     (u_int32_t)ntohl(spi)));
 184                 ipsecstat.in_badspi++;
 185                 goto bad;
 186         }
 187
 188         /* check if we have proper ivlen information */
 189         ivlen = sav->ivlen;
 190         if (ivlen < 0) {
 191                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
 192                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 193                 ipsecstat.in_inval++;
 194                 goto bad;
 195         }
 196
 197         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 198          && (sav->alg_auth && sav->key_auth)))
 199                 goto noreplaycheck;
 200
 201         if (sav->alg_auth == SADB_X_AALG_NULL ||
 202             sav->alg_auth == SADB_AALG_NONE)
 203                 goto noreplaycheck;
 204
 205         /*
 206          * check for sequence number.
 207          */
 208         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 209                 ; /*okey*/
 210         else {
 211                 ipsecstat.in_espreplay++;
 212                 ipseclog((LOG_WARNING,
 213                     "replay packet in IPv4 ESP input: %s %s\n",
 214                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 215                 goto bad;
 216         }
 217
 218         /* check ICV */
 219     {
 220         u_char sum0[AH_MAXSUMSIZE];
 221         u_char sum[AH_MAXSUMSIZE];
 222         const struct ah_algorithm *sumalgo;
 223         size_t siz;
 224
 225         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 226         if (!sumalgo)
 227                 goto noreplaycheck;
 228         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 229         if (AH_MAXSUMSIZE < siz) {
 230                 ipseclog((LOG_DEBUG,
 231                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 232                     (u_long)siz));
 233                 ipsecstat.in_inval++;
 234                 goto bad;
 235         }
 236
 237         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 238
 239         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 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         if (bcmp(sum0, sum, siz) != 0) {
 247                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
 248                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 249                 ipsecstat.in_espauthfail++;
 250                 goto bad;
 251         }
 252
 253         /* strip off the authentication data */
 254         m_adj(m, -siz);
 255         ip = mtod(m, struct ip *);
 256 #ifdef IPLEN_FLIPPED
 257         ip->ip_len = ip->ip_len - siz;
 258 #else
 259         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
 260 #endif
 261         m->m_flags |= M_AUTHIPDGM;
 262         ipsecstat.in_espauthsucc++;
 263     }
 264
 265         /*
 266          * update sequence number.
 267          */
 268         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 269                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 270                         ipsecstat.in_espreplay++;
 271                         goto bad;
 272                 }
 273         }
 274
 275 noreplaycheck:
 276
 277         /* process main esp header. */
 278         if (sav->flags & SADB_X_EXT_OLD) {
 279                 /* RFC 1827 */
 280                 esplen = sizeof(struct esp);
 281         } else {
 282                 /* RFC 2406 */
 283                 if (sav->flags & SADB_X_EXT_DERIV)
 284                         esplen = sizeof(struct esp);
 285                 else
 286                         esplen = sizeof(struct newesp);
 287         }
 288
 289         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 290                 ipseclog((LOG_WARNING,
 291                     "IPv4 ESP input: packet too short\n"));
 292                 ipsecstat.in_inval++;
 293                 goto bad;
 294         }
 295
 296         if (m->m_len < off + esplen + ivlen) {
 297                 m = m_pullup(m, off + esplen + ivlen);
 298                 if (!m) {
 299                         ipseclog((LOG_DEBUG,
 300                             "IPv4 ESP input: can't pullup in esp4_input\n"));
 301                         ipsecstat.in_inval++;
 302                         goto bad;
 303                 }
 304         }
 305
 306         /*
 307          * pre-compute and cache intermediate key
 308          */
 309         if (esp_schedule(algo, sav) != 0) {
 310                 ipsecstat.in_inval++;
 311                 goto bad;
 312         }
 313
 314         /*
 315          * decrypt the packet.
 316          */
 317         if (!algo->decrypt)
 318                 panic("internal error: no decrypt function");
 319         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 320                 /* m is already freed */
 321                 m = NULL;
 322                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
 323                     ipsec_logsastr(sav)));
 324                 ipsecstat.in_inval++;
 325                 goto bad;
 326         }
 327         ipsecstat.in_esphist[sav->alg_enc]++;
 328
 329         m->m_flags |= M_DECRYPTED;
 330
 331         /*
 332          * find the trailer of the ESP.
 333          */
 334         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 335              (caddr_t)&esptail);
 336         nxt = esptail.esp_nxt;
 337         taillen = esptail.esp_padlen + sizeof(esptail);
 338
 339         if (m->m_pkthdr.len < taillen
 340          || m->m_pkthdr.len - taillen < hlen) { /*?*/
 341                 ipseclog((LOG_WARNING,
 342                     "bad pad length in IPv4 ESP input: %s %s\n",
 343                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 344                 ipsecstat.in_inval++;
 345                 goto bad;
 346         }
 347
 348         /* strip off the trailing pad area. */
 349         m_adj(m, -taillen);
 350
 351 #ifdef IPLEN_FLIPPED
 352         ip->ip_len = ip->ip_len - taillen;
 353 #else
 354         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
 355 #endif
 356
 357         /* was it transmitted over the IPsec tunnel SA? */
 358         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 359                 /*
 360                  * strip off all the headers that precedes ESP header.
 361                  *      IP4 xx ESP IP4' payload -> IP4' payload
 362                  *
 363                  * XXX more sanity checks
 364                  * XXX relationship with gif?
 365                  */
 366                 u_int8_t tos;
 367
 368                 tos = ip->ip_tos;
 369                 m_adj(m, off + esplen + ivlen);
 370                 if (m->m_len < sizeof(*ip)) {
 371                         m = m_pullup(m, sizeof(*ip));
 372                         if (!m) {
 373                                 ipsecstat.in_inval++;
 374                                 goto bad;
 375                         }
 376                 }
 377                 ip = mtod(m, struct ip *);
 378                 /* ECN consideration. */
 379                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 380                 if (!key_checktunnelsanity(sav, AF_INET,
 381                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 382                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 383                             "in IPv4 ESP input: %s %s\n",
 384                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 385                         ipsecstat.in_inval++;
 386                         goto bad;
 387                 }
 388
 389 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 390                 /* drop it if it does not match the default policy */
 391                 if (ipsec4_in_reject(m, NULL)) {
 392                         ipsecstat.in_polvio++;
 393                         goto bad;
 394                 }
 395 #endif
 396
 397                 key_sa_recordxfer(sav, m);
 398                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 399                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 400                         ipsecstat.in_nomem++;
 401                         goto bad;
 402                 }
 403
 404                 if (! IF_HANDOFF(&ipintrq, m, NULL)) {
 405                         ipsecstat.in_inval++;
 406                         m = NULL;
 407                         goto bad;
 408                 }
 409                 m = NULL;
 410                 schednetisr(NETISR_IP); /*can be skipped but to make sure*/
 411                 nxt = IPPROTO_DONE;
 412         } else {
 413                 /*
 414                  * strip off ESP header and IV.
 415                  * even in m_pulldown case, we need to strip off ESP so that
 416                  * we can always compute checksum for AH correctly.
 417                  */
 418                 size_t stripsiz;
 419
 420                 stripsiz = esplen + ivlen;
 421
 422                 ip = mtod(m, struct ip *);
 423                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 424                 m->m_data += stripsiz;
 425                 m->m_len -= stripsiz;
 426                 m->m_pkthdr.len -= stripsiz;
 427
 428                 ip = mtod(m, struct ip *);
 429 #ifdef IPLEN_FLIPPED
 430                 ip->ip_len = ip->ip_len - stripsiz;
 431 #else
 432                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 433 #endif
 434                 ip->ip_p = nxt;
 435
 436                 key_sa_recordxfer(sav, m);
 437                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 438                         ipsecstat.in_nomem++;
 439                         goto bad;
 440                 }
 441
 442                 if (nxt != IPPROTO_DONE) {
 443                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 444                             ipsec4_in_reject(m, NULL)) {
 445                                 ipsecstat.in_polvio++;
 446                                 goto bad;
 447                         }
 448                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 449                 } else
 450                         m_freem(m);
 451                 m = NULL;
 452         }
 453
 454         if (sav) {
 455                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 456                         printf("DP esp4_input call free SA:%p\n", sav));
 457                 key_freesav(sav);
 458         }
 459         ipsecstat.in_success++;
 460         return;
 461
 462 bad:
 463         if (sav) {
 464                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 465                         printf("DP esp4_input call free SA:%p\n", sav));
 466                 key_freesav(sav);
 467         }
 468         if (m)
 469                 m_freem(m);
 470         return;
 471 }
 472 #endif /* INET */
 473
 474 #ifdef INET6
 475 int
 476 esp6_input(mp, offp, proto)
 477         struct mbuf **mp;
 478         int *offp, proto;
 479 {
 480         struct mbuf *m = *mp;
 481         int off = *offp;
 482         struct ip6_hdr *ip6;
 483         struct esp *esp;
 484         struct esptail esptail;
 485         u_int32_t spi;
 486         struct secasvar *sav = NULL;
 487         size_t taillen;
 488         u_int16_t nxt;
 489         const struct esp_algorithm *algo;
 490         int ivlen;
 491         size_t esplen;
 492
 493         /* sanity check for alignment. */
 494         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
 495                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
 496                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
 497                 ipsec6stat.in_inval++;
 498                 goto bad;
 499         }
 500
 501 #ifndef PULLDOWN_TEST
 502         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
 503         esp = (struct esp *)(mtod(m, caddr_t) + off);
 504 #else
 505         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
 506         if (esp == NULL) {
 507                 ipsec6stat.in_inval++;
 508                 return IPPROTO_DONE;
 509         }
 510 #endif
 511         ip6 = mtod(m, struct ip6_hdr *);
 512
 513         if (ntohs(ip6->ip6_plen) == 0) {
 514                 ipseclog((LOG_ERR, "IPv6 ESP input: "
 515                     "ESP with IPv6 jumbogram is not supported.\n"));
 516                 ipsec6stat.in_inval++;
 517                 goto bad;
 518         }
 519
 520         /* find the sassoc. */
 521         spi = esp->esp_spi;
 522
 523         if ((sav = key_allocsa(AF_INET6,
 524                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 525                               IPPROTO_ESP, spi)) == 0) {
 526                 ipseclog((LOG_WARNING,
 527                     "IPv6 ESP input: no key association found for spi %u\n",
 528                     (u_int32_t)ntohl(spi)));
 529                 ipsec6stat.in_nosa++;
 530                 goto bad;
 531         }
 532         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 533                 printf("DP esp6_input called to allocate SA:%p\n", sav));
 534         if (sav->state != SADB_SASTATE_MATURE
 535          && sav->state != SADB_SASTATE_DYING) {
 536                 ipseclog((LOG_DEBUG,
 537                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
 538                     (u_int32_t)ntohl(spi)));
 539                 ipsec6stat.in_badspi++;
 540                 goto bad;
 541         }
 542         algo = esp_algorithm_lookup(sav->alg_enc);
 543         if (!algo) {
 544                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
 545                     "unsupported encryption algorithm for spi %u\n",
 546                     (u_int32_t)ntohl(spi)));
 547                 ipsec6stat.in_badspi++;
 548                 goto bad;
 549         }
 550
 551         /* check if we have proper ivlen information */
 552         ivlen = sav->ivlen;
 553         if (ivlen < 0) {
 554                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
 555                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 556                 ipsec6stat.in_badspi++;
 557                 goto bad;
 558         }
 559
 560         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
 561          && (sav->alg_auth && sav->key_auth)))
 562                 goto noreplaycheck;
 563
 564         if (sav->alg_auth == SADB_X_AALG_NULL ||
 565             sav->alg_auth == SADB_AALG_NONE)
 566                 goto noreplaycheck;
 567
 568         /*
 569          * check for sequence number.
 570          */
 571         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
 572                 ; /*okey*/
 573         else {
 574                 ipsec6stat.in_espreplay++;
 575                 ipseclog((LOG_WARNING,
 576                     "replay packet in IPv6 ESP input: %s %s\n",
 577                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 578                 goto bad;
 579         }
 580
 581         /* check ICV */
 582     {
 583         u_char sum0[AH_MAXSUMSIZE];
 584         u_char sum[AH_MAXSUMSIZE];
 585         const struct ah_algorithm *sumalgo;
 586         size_t siz;
 587
 588         sumalgo = ah_algorithm_lookup(sav->alg_auth);
 589         if (!sumalgo)
 590                 goto noreplaycheck;
 591         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
 592         if (AH_MAXSUMSIZE < siz) {
 593                 ipseclog((LOG_DEBUG,
 594                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
 595                     (u_long)siz));
 596                 ipsec6stat.in_inval++;
 597                 goto bad;
 598         }
 599
 600         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
 601
 602         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
 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         if (bcmp(sum0, sum, siz) != 0) {
 610                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
 611                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 612                 ipsec6stat.in_espauthfail++;
 613                 goto bad;
 614         }
 615
 616         /* strip off the authentication data */
 617         m_adj(m, -siz);
 618         ip6 = mtod(m, struct ip6_hdr *);
 619         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
 620
 621         m->m_flags |= M_AUTHIPDGM;
 622         ipsec6stat.in_espauthsucc++;
 623     }
 624
 625         /*
 626          * update sequence number.
 627          */
 628         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 629                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
 630                         ipsec6stat.in_espreplay++;
 631                         goto bad;
 632                 }
 633         }
 634
 635 noreplaycheck:
 636
 637         /* process main esp header. */
 638         if (sav->flags & SADB_X_EXT_OLD) {
 639                 /* RFC 1827 */
 640                 esplen = sizeof(struct esp);
 641         } else {
 642                 /* RFC 2406 */
 643                 if (sav->flags & SADB_X_EXT_DERIV)
 644                         esplen = sizeof(struct esp);
 645                 else
 646                         esplen = sizeof(struct newesp);
 647         }
 648
 649         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
 650                 ipseclog((LOG_WARNING,
 651                     "IPv6 ESP input: packet too short\n"));
 652                 ipsec6stat.in_inval++;
 653                 goto bad;
 654         }
 655
 656 #ifndef PULLDOWN_TEST
 657         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /*XXX*/
 658 #else
 659         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
 660         if (esp == NULL) {
 661                 ipsec6stat.in_inval++;
 662                 m = NULL;
 663                 goto bad;
 664         }
 665 #endif
 666         ip6 = mtod(m, struct ip6_hdr *);        /*set it again just in case*/
 667
 668         /*
 669          * pre-compute and cache intermediate key
 670          */
 671         if (esp_schedule(algo, sav) != 0) {
 672                 ipsec6stat.in_inval++;
 673                 goto bad;
 674         }
 675
 676         /*
 677          * decrypt the packet.
 678          */
 679         if (!algo->decrypt)
 680                 panic("internal error: no decrypt function");
 681         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
 682                 /* m is already freed */
 683                 m = NULL;
 684                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
 685                     ipsec_logsastr(sav)));
 686                 ipsec6stat.in_inval++;
 687                 goto bad;
 688         }
 689         ipsec6stat.in_esphist[sav->alg_enc]++;
 690
 691         m->m_flags |= M_DECRYPTED;
 692
 693         /*
 694          * find the trailer of the ESP.
 695          */
 696         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
 697              (caddr_t)&esptail);
 698         nxt = esptail.esp_nxt;
 699         taillen = esptail.esp_padlen + sizeof(esptail);
 700
 701         if (m->m_pkthdr.len < taillen
 702          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /*?*/
 703                 ipseclog((LOG_WARNING,
 704                     "bad pad length in IPv6 ESP input: %s %s\n",
 705                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 706                 ipsec6stat.in_inval++;
 707                 goto bad;
 708         }
 709
 710         /* strip off the trailing pad area. */
 711         m_adj(m, -taillen);
 712
 713         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
 714
 715         /* was it transmitted over the IPsec tunnel SA? */
 716         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
 717                 /*
 718                  * strip off all the headers that precedes ESP header.
 719                  *      IP6 xx ESP IP6' payload -> IP6' payload
 720                  *
 721                  * XXX more sanity checks
 722                  * XXX relationship with gif?
 723                  */
 724                 u_int32_t flowinfo;     /*net endian*/
 725                 flowinfo = ip6->ip6_flow;
 726                 m_adj(m, off + esplen + ivlen);
 727                 if (m->m_len < sizeof(*ip6)) {
 728 #ifndef PULLDOWN_TEST
 729                         /*
 730                          * m_pullup is prohibited in KAME IPv6 input processing
 731                          * but there's no other way!
 732                          */
 733 #else
 734                         /* okay to pullup in m_pulldown style */
 735 #endif
 736                         m = m_pullup(m, sizeof(*ip6));
 737                         if (!m) {
 738                                 ipsec6stat.in_inval++;
 739                                 goto bad;
 740                         }
 741                 }
 742                 ip6 = mtod(m, struct ip6_hdr *);
 743                 /* ECN consideration. */
 744                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 745                 if (!key_checktunnelsanity(sav, AF_INET6,
 746                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 747                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
 748                             "in IPv6 ESP input: %s %s\n",
 749                             ipsec6_logpacketstr(ip6, spi),
 750                             ipsec_logsastr(sav)));
 751                         ipsec6stat.in_inval++;
 752                         goto bad;
 753                 }
 754
 755 #if 0 /* XXX should call ipfw rather than ipsec_in_reject, shouldn't it ? */
 756                 /* drop it if it does not match the default policy */
 757                 if (ipsec6_in_reject(m, NULL)) {
 758                         ipsec6stat.in_polvio++;
 759                         goto bad;
 760                 }
 761 #endif
 762
 763                 key_sa_recordxfer(sav, m);
 764                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
 765                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 766                         ipsec6stat.in_nomem++;
 767                         goto bad;
 768                 }
 769
 770                 if (! IF_HANDOFF(&ip6intrq, m, NULL)) {
 771                         ipsec6stat.in_inval++;
 772                         m = NULL;
 773                         goto bad;
 774                 }
 775                 m = NULL;
 776                 schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
 777                 nxt = IPPROTO_DONE;
 778         } else {
 779                 /*
 780                  * strip off ESP header and IV.
 781                  * even in m_pulldown case, we need to strip off ESP so that
 782                  * we can always compute checksum for AH correctly.
 783                  */
 784                 size_t stripsiz;
 785                 char *prvnxtp;
 786
 787                 /*
 788                  * Set the next header field of the previous header correctly.
 789                  */
 790                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 791                 *prvnxtp = nxt;
 792
 793                 stripsiz = esplen + ivlen;
 794
 795                 ip6 = mtod(m, struct ip6_hdr *);
 796                 if (m->m_len >= stripsiz + off) {
 797                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 798                         m->m_data += stripsiz;
 799                         m->m_len -= stripsiz;
 800                         m->m_pkthdr.len -= stripsiz;
 801                 } else {
 802                         /*
 803                          * this comes with no copy if the boundary is on
 804                          * cluster
 805                          */
 806                         struct mbuf *n;
 807
 808                         n = m_split(m, off, M_DONTWAIT);
 809                         if (n == NULL) {
 810                                 /* m is retained by m_split */
 811                                 goto bad;
 812                         }
 813                         m_adj(n, stripsiz);
 814                         m_cat(m, n);
 815                         /* m_cat does not update m_pkthdr.len */
 816                         m->m_pkthdr.len += n->m_pkthdr.len;
 817                 }
 818
 819 #ifndef PULLDOWN_TEST
 820                 /*
 821                  * KAME requires that the packet to be contiguous on the
 822                  * mbuf.  We need to make that sure.
 823                  * this kind of code should be avoided.
 824                  * XXX other conditions to avoid running this part?
 825                  */
 826                 if (m->m_len != m->m_pkthdr.len) {
 827                         struct mbuf *n = NULL;
 828                         int maxlen;
 829
 830                         MGETHDR(n, M_DONTWAIT, MT_HEADER);
 831                         maxlen = MHLEN;
 832                         if (n)
 833                                 M_COPY_PKTHDR(n, m);
 834                         if (n && m->m_pkthdr.len > maxlen) {
 835                                 MCLGET(n, M_DONTWAIT);
 836                                 maxlen = MCLBYTES;
 837                                 if ((n->m_flags & M_EXT) == 0) {
 838                                         m_free(n);
 839                                         n = NULL;
 840                                 }
 841                         }
 842                         if (!n) {
 843                                 printf("esp6_input: mbuf allocation failed\n");
 844                                 goto bad;
 845                         }
 846
 847                         if (m->m_pkthdr.len <= maxlen) {
 848                                 m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
 849                                 n->m_len = m->m_pkthdr.len;
 850                                 n->m_pkthdr.len = m->m_pkthdr.len;
 851                                 n->m_next = NULL;
 852                                 m_freem(m);
 853                         } else {
 854                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
 855                                 m_adj(m, maxlen);
 856                                 n->m_len = maxlen;
 857                                 n->m_pkthdr.len = m->m_pkthdr.len;
 858                                 n->m_next = m;
 859                                 m->m_flags &= ~M_PKTHDR;
 860                         }
 861                         m = n;
 862                 }
 863 #endif
 864
 865                 ip6 = mtod(m, struct ip6_hdr *);
 866                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 867
 868                 key_sa_recordxfer(sav, m);
 869                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
 870                         ipsec6stat.in_nomem++;
 871                         goto bad;
 872                 }
 873         }
 874
 875         *offp = off;
 876         *mp = m;
 877
 878         if (sav) {
 879                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 880                         printf("DP esp6_input call free SA:%p\n", sav));
 881                 key_freesav(sav);
 882         }
 883         ipsec6stat.in_success++;
 884         return nxt;
 885
 886 bad:
 887         if (sav) {
 888                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 889                         printf("DP esp6_input call free SA:%p\n", sav));
 890                 key_freesav(sav);
 891         }
 892         if (m)
 893                 m_freem(m);
 894         return IPPROTO_DONE;
 895 }
 896
 897 void
 898 esp6_ctlinput(cmd, sa, d)
 899         int cmd;
 900         struct sockaddr *sa;
 901         void *d;
 902 {
 903         const struct newesp *espp;
 904         struct newesp esp;
 905         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
 906         struct secasvar *sav;
 907         struct ip6_hdr *ip6;
 908         struct mbuf *m;
 909         int off;
 910         struct sockaddr_in6 sa6_src, sa6_dst;
 911
 912         if (sa->sa_family != AF_INET6 ||
 913             sa->sa_len != sizeof(struct sockaddr_in6))
 914                 return;
 915         if ((unsigned)cmd >= PRC_NCMDS)
 916                 return;
 917
 918         /* if the parameter is from icmp6, decode it. */
 919         if (d != NULL) {
 920                 ip6cp = (struct ip6ctlparam *)d;
 921                 m = ip6cp->ip6c_m;
 922                 ip6 = ip6cp->ip6c_ip6;
 923                 off = ip6cp->ip6c_off;
 924         } else {
 925                 m = NULL;
 926                 ip6 = NULL;
 927         }
 928
 929         if (ip6) {
 930                 /*
 931                  * Notify the error to all possible sockets via pfctlinput2.
 932                  * Since the upper layer information (such as protocol type,
 933                  * source and destination ports) is embedded in the encrypted
 934                  * data and might have been cut, we can't directly call
 935                  * an upper layer ctlinput function. However, the pcbnotify
 936                  * function will consider source and destination addresses
 937                  * as well as the flow info value, and may be able to find
 938                  * some PCB that should be notified.
 939                  * Although pfctlinput2 will call esp6_ctlinput(), there is
 940                  * no possibility of an infinite loop of function calls,
 941                  * because we don't pass the inner IPv6 header.
 942                  */
 943                 bzero(&ip6cp1, sizeof(ip6cp1));
 944                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
 945                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
 946
 947                 /*
 948                  * Then go to special cases that need ESP header information.
 949                  * XXX: We assume that when ip6 is non NULL,
 950                  * M and OFF are valid.
 951                  */
 952
 953                 /* check if we can safely examine src and dst ports */
 954                 if (m->m_pkthdr.len < off + sizeof(esp))
 955                         return;
 956
 957                 if (m->m_len < off + sizeof(esp)) {
 958                         /*
 959                          * this should be rare case,
 960                          * so we compromise on this copy...
 961                          */
 962                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
 963                         espp = &esp;
 964                 } else
 965                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
 966
 967                 if (cmd == PRC_MSGSIZE) {
 968                         int valid = 0;
 969
 970                         /*
 971                          * Check to see if we have a valid SA corresponding to
 972                          * the address in the ICMP message payload.
 973                          */
 974                         sav = key_allocsa(AF_INET6,
 975                                           (caddr_t)&sa6_src.sin6_addr,
 976                                           (caddr_t)&sa6_dst, IPPROTO_ESP,
 977                                           espp->esp_spi);
 978                         if (sav) {
 979                                 if (sav->state == SADB_SASTATE_MATURE ||
 980                                     sav->state == SADB_SASTATE_DYING)
 981                                         valid++;
 982                                 key_freesav(sav);
 983                         }
 984
 985                         /* XXX Further validation? */
 986
 987                         /*
 988                          * Depending on the value of "valid" and routing table
 989                          * size (mtudisc_{hi,lo}wat), we will:
 990                          * - recalcurate the new MTU and create the
 991                          *   corresponding routing entry, or
 992                          * - ignore the MTU change notification.
 993                          */
 994                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
 995                 }
 996         } else {
 997                 /* we normally notify any pcb here */
 998         }
 999 }
1000 #endif /* INET6 */