sys/netinet6/ah_input.c

   1 /*      $FreeBSD: src/sys/netinet6/ah_input.c,v 1.1.2.6 2002/04/28 05:40:26 suz Exp $   */
   2 /*      $KAME: ah_input.c,v 1.67 2002/01/07 11:39:56 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  * RFC1826/2402 authentication header.
  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/malloc.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 #include <machine/stdarg.h>
  56
  57 #include <netinet/in.h>
  58 #include <netinet/in_systm.h>
  59 #include <netinet/in_var.h>
  60 #include <netinet/ip.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/ip_ecn.h>
  63 #ifdef INET6
  64 #include <netinet6/ip6_ecn.h>
  65 #endif
  66
  67 #ifdef INET6
  68 #include <netinet/ip6.h>
  69 #include <netinet6/ip6_var.h>
  70 #include <netinet6/in6_pcb.h>
  71 #include <netinet/icmp6.h>
  72 #include <netinet6/ip6protosw.h>
  73 #endif
  74
  75 #include <netinet6/ipsec.h>
  76 #ifdef INET6
  77 #include <netinet6/ipsec6.h>
  78 #endif
  79 #include <netinet6/ah.h>
  80 #ifdef INET6
  81 #include <netinet6/ah6.h>
  82 #endif
  83 #include <netproto/key/key.h>
  84 #include <netproto/key/keydb.h>
  85 #ifdef IPSEC_DEBUG
  86 #include <netproto/key/key_debug.h>
  87 #else
  88 #define KEYDEBUG(lev,arg)
  89 #endif
  90
  91 #include <net/net_osdep.h>
  92
  93 #define IPLEN_FLIPPED
  94
  95 #ifdef INET
  96 extern struct protosw inetsw[];
  97
  98 int
  99 ah4_input(struct mbuf **mp, int *offp, int proto)
 100 {
 101         int off;
 102         struct mbuf *m;
 103         struct ip *ip;
 104         struct ah *ah;
 105         u_int32_t spi;
 106         const struct ah_algorithm *algo;
 107         size_t siz;
 108         size_t siz1;
 109         u_char *cksum;
 110         struct secasvar *sav = NULL;
 111         u_int16_t nxt;
 112         size_t hlen;
 113         size_t stripsiz = 0;
 114
 115         off = *offp;
 116         m = *mp;
 117         *mp = NULL;
 118
 119 #ifndef PULLDOWN_TEST
 120         if (m->m_len < off + sizeof(struct newah)) {
 121                 m = m_pullup(m, off + sizeof(struct newah));
 122                 if (!m) {
 123                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 124                                 "dropping the packet for simplicity\n"));
 125                         ipsecstat.in_inval++;
 126                         goto fail;
 127                 }
 128         }
 129
 130         ip = mtod(m, struct ip *);
 131         ah = (struct ah *)(((caddr_t)ip) + off);
 132 #else
 133         ip = mtod(m, struct ip *);
 134         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 135         if (ah == NULL) {
 136                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 137                         "dropping the packet for simplicity\n"));
 138                 ipsecstat.in_inval++;
 139                 goto fail;
 140         }
 141 #endif
 142         nxt = ah->ah_nxt;
 143 #ifdef _IP_VHL
 144         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 145 #else
 146         hlen = ip->ip_hl << 2;
 147 #endif
 148
 149         /* find the sassoc. */
 150         spi = ah->ah_spi;
 151
 152         if ((sav = key_allocsa(AF_INET,
 153                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 154                               IPPROTO_AH, spi)) == NULL) {
 155                 ipseclog((LOG_WARNING,
 156                     "IPv4 AH input: no key association found for spi %u\n",
 157                     (u_int32_t)ntohl(spi)));
 158                 ipsecstat.in_nosa++;
 159                 goto fail;
 160         }
 161         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 162                 kprintf("DP ah4_input called to allocate SA:%p\n", sav));
 163         if (sav->state != SADB_SASTATE_MATURE
 164          && sav->state != SADB_SASTATE_DYING) {
 165                 ipseclog((LOG_DEBUG,
 166                     "IPv4 AH input: non-mature/dying SA found for spi %u\n",
 167                     (u_int32_t)ntohl(spi)));
 168                 ipsecstat.in_badspi++;
 169                 goto fail;
 170         }
 171
 172         algo = ah_algorithm_lookup(sav->alg_auth);
 173         if (!algo) {
 174                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 175                     "unsupported authentication algorithm for spi %u\n",
 176                     (u_int32_t)ntohl(spi)));
 177                 ipsecstat.in_badspi++;
 178                 goto fail;
 179         }
 180
 181         siz = (*algo->sumsiz)(sav);
 182         siz1 = ((siz + 3) & ~(4 - 1));
 183
 184         /*
 185          * sanity checks for header, 1.
 186          */
 187     {
 188         int sizoff;
 189
 190         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 191
 192         /*
 193          * Here, we do not do "siz1 == siz".  This is because the way
 194          * RFC240[34] section 2 is written.  They do not require truncation
 195          * to 96 bits.
 196          * For example, Microsoft IPsec stack attaches 160 bits of
 197          * authentication data for both hmac-md5 and hmac-sha1.  For hmac-sha1,
 198          * 32 bits of padding is attached.
 199          *
 200          * There are two downsides to this specification.
 201          * They have no real harm, however, they leave us fuzzy feeling.
 202          * - if we attach more than 96 bits of authentication data onto AH,
 203          *   we will never notice about possible modification by rogue
 204          *   intermediate nodes.
 205          *   Since extra bits in AH checksum is never used, this constitutes
 206          *   no real issue, however, it is wacky.
 207          * - even if the peer attaches big authentication data, we will never
 208          *   notice the difference, since longer authentication data will just
 209          *   work.
 210          *
 211          * We may need some clarification in the spec.
 212          */
 213         if (siz1 < siz) {
 214                 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
 215                     "(%lu, should be at least %lu): %s\n",
 216                     (u_long)siz1, (u_long)siz,
 217                     ipsec4_logpacketstr(ip, spi)));
 218                 ipsecstat.in_inval++;
 219                 goto fail;
 220         }
 221         if ((ah->ah_len << 2) - sizoff != siz1) {
 222                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
 223                     "(%d should be %lu): %s\n",
 224                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 225                     ipsec4_logpacketstr(ip, spi)));
 226                 ipsecstat.in_inval++;
 227                 goto fail;
 228         }
 229
 230 #ifndef PULLDOWN_TEST
 231         if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
 232                 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
 233                 if (!m) {
 234                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 235                         ipsecstat.in_inval++;
 236                         goto fail;
 237                 }
 238
 239                 ip = mtod(m, struct ip *);
 240                 ah = (struct ah *)(((caddr_t)ip) + off);
 241         }
 242 #else
 243         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 244                 sizeof(struct ah) + sizoff + siz1);
 245         if (ah == NULL) {
 246                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 247                 ipsecstat.in_inval++;
 248                 goto fail;
 249         }
 250 #endif
 251     }
 252
 253         /*
 254          * check for sequence number.
 255          */
 256         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 257                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 258                         ; /* okey */
 259                 else {
 260                         ipsecstat.in_ahreplay++;
 261                         ipseclog((LOG_WARNING,
 262                             "replay packet in IPv4 AH input: %s %s\n",
 263                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 264                         goto fail;
 265                 }
 266         }
 267
 268         /*
 269          * alright, it seems sane.  now we are going to check the
 270          * cryptographic checksum.
 271          */
 272         cksum = kmalloc(siz1, M_TEMP, M_NOWAIT);
 273         if (!cksum) {
 274                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 275                     "couldn't alloc temporary region for cksum\n"));
 276                 ipsecstat.in_inval++;
 277                 goto fail;
 278         }
 279
 280         /*
 281          * some of IP header fields are flipped to the host endian.
 282          * convert them back to network endian.  VERY stupid.
 283          */
 284         ip->ip_len = htons(ip->ip_len + hlen);
 285         ip->ip_off = htons(ip->ip_off);
 286         if (ah4_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 287                 kfree(cksum, M_TEMP);
 288                 ipsecstat.in_inval++;
 289                 goto fail;
 290         }
 291         ipsecstat.in_ahhist[sav->alg_auth]++;
 292         /*
 293          * flip them back.
 294          */
 295         ip->ip_len = ntohs(ip->ip_len) - hlen;
 296         ip->ip_off = ntohs(ip->ip_off);
 297
 298     {
 299         caddr_t sumpos = NULL;
 300
 301         if (sav->flags & SADB_X_EXT_OLD) {
 302                 /* RFC 1826 */
 303                 sumpos = (caddr_t)(ah + 1);
 304         } else {
 305                 /* RFC 2402 */
 306                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 307         }
 308
 309         if (bcmp(sumpos, cksum, siz) != 0) {
 310                 ipseclog((LOG_WARNING,
 311                     "checksum mismatch in IPv4 AH input: %s %s\n",
 312                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 313                 kfree(cksum, M_TEMP);
 314                 ipsecstat.in_ahauthfail++;
 315                 goto fail;
 316         }
 317     }
 318
 319         kfree(cksum, M_TEMP);
 320
 321         m->m_flags |= M_AUTHIPHDR;
 322         m->m_flags |= M_AUTHIPDGM;
 323
 324 #if 0
 325         /*
 326          * looks okey, but we need more sanity check.
 327          * XXX should elaborate.
 328          */
 329         if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
 330                 struct ip *nip;
 331                 size_t sizoff;
 332
 333                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 334
 335                 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
 336                         m = m_pullup(m, off + sizeof(struct ah)
 337                                         + sizoff + siz1 + hlen);
 338                         if (!m) {
 339                                 ipseclog((LOG_DEBUG,
 340                                     "IPv4 AH input: can't pullup\n"));
 341                                 ipsecstat.in_inval++;
 342                                 goto fail;
 343                         }
 344                 }
 345
 346                 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
 347                 if (nip->ip_src.s_addr != ip->ip_src.s_addr
 348                  || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
 349                         m->m_flags &= ~M_AUTHIPHDR;
 350                         m->m_flags &= ~M_AUTHIPDGM;
 351                 }
 352         }
 353 #ifdef INET6
 354         else if (ah->ah_nxt == IPPROTO_IPV6) {
 355                 m->m_flags &= ~M_AUTHIPHDR;
 356                 m->m_flags &= ~M_AUTHIPDGM;
 357         }
 358 #endif /* INET6 */
 359 #endif /* 0 */
 360
 361         if (m->m_flags & M_AUTHIPHDR
 362          && m->m_flags & M_AUTHIPDGM) {
 363 #if 0
 364                 ipseclog((LOG_DEBUG,
 365                     "IPv4 AH input: authentication succeess\n"));
 366 #endif
 367                 ipsecstat.in_ahauthsucc++;
 368         } else {
 369                 ipseclog((LOG_WARNING,
 370                     "authentication failed in IPv4 AH input: %s %s\n",
 371                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 372                 ipsecstat.in_ahauthfail++;
 373                 goto fail;
 374         }
 375
 376         /*
 377          * update sequence number.
 378          */
 379         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 380                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 381                         ipsecstat.in_ahreplay++;
 382                         goto fail;
 383                 }
 384         }
 385
 386         /* was it transmitted over the IPsec tunnel SA? */
 387         if (sav->flags & SADB_X_EXT_OLD) {
 388                 /* RFC 1826 */
 389                 stripsiz = sizeof(struct ah) + siz1;
 390         } else {
 391                 /* RFC 2402 */
 392                 stripsiz = sizeof(struct newah) + siz1;
 393         }
 394         if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 395                 /*
 396                  * strip off all the headers that precedes AH.
 397                  *      IP xx AH IP' payload -> IP' payload
 398                  *
 399                  * XXX more sanity checks
 400                  * XXX relationship with gif?
 401                  */
 402                 u_int8_t tos;
 403
 404                 tos = ip->ip_tos;
 405                 m_adj(m, off + stripsiz);
 406                 if (m->m_len < sizeof(*ip)) {
 407                         m = m_pullup(m, sizeof(*ip));
 408                         if (!m) {
 409                                 ipsecstat.in_inval++;
 410                                 goto fail;
 411                         }
 412                 }
 413                 ip = mtod(m, struct ip *);
 414                 /* ECN consideration. */
 415                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 416                 if (!key_checktunnelsanity(sav, AF_INET,
 417                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 418                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 419                             "in IPv4 AH input: %s %s\n",
 420                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 421                         ipsecstat.in_inval++;
 422                         goto fail;
 423                 }
 424
 425 #if 1
 426                 /*
 427                  * Should the inner packet be considered authentic?
 428                  * My current answer is: NO.
 429                  *
 430                  * host1 -- gw1 === gw2 -- host2
 431                  *      In this case, gw2 can trust the authenticity of the
 432                  *      outer packet, but NOT inner.  Packet may be altered
 433                  *      between host1 and gw1.
 434                  *
 435                  * host1 -- gw1 === host2
 436                  *      This case falls into the same scenario as above.
 437                  *
 438                  * host1 === host2
 439                  *      This case is the only case when we may be able to leave
 440                  *      M_AUTHIPHDR and M_AUTHIPDGM set.
 441                  *      However, if host1 is wrongly configured, and allows
 442                  *      attacker to inject some packet with src=host1 and
 443                  *      dst=host2, you are in risk.
 444                  */
 445                 m->m_flags &= ~M_AUTHIPHDR;
 446                 m->m_flags &= ~M_AUTHIPDGM;
 447 #endif
 448
 449                 key_sa_recordxfer(sav, m);
 450                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 451                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 452                         ipsecstat.in_nomem++;
 453                         goto fail;
 454                 }
 455
 456                 if (netisr_queue(NETISR_IP, m)) {
 457                         ipsecstat.in_inval++;
 458                         m = NULL;
 459                         goto fail;
 460                 }
 461
 462                 nxt = IPPROTO_DONE;
 463         } else {
 464                 /*
 465                  * strip off AH.
 466                  */
 467
 468                 ip = mtod(m, struct ip *);
 469 #ifndef PULLDOWN_TEST
 470                 /*
 471                  * We do deep-copy since KAME requires that
 472                  * the packet is placed in a single external mbuf.
 473                  */
 474                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 475                 m->m_data += stripsiz;
 476                 m->m_len -= stripsiz;
 477                 m->m_pkthdr.len -= stripsiz;
 478 #else
 479                 /*
 480                  * even in m_pulldown case, we need to strip off AH so that
 481                  * we can compute checksum for multiple AH correctly.
 482                  */
 483                 if (m->m_len >= stripsiz + off) {
 484                         ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
 485                         m->m_data += stripsiz;
 486                         m->m_len -= stripsiz;
 487                         m->m_pkthdr.len -= stripsiz;
 488                 } else {
 489                         /*
 490                          * this comes with no copy if the boundary is on
 491                          * cluster
 492                          */
 493                         struct mbuf *n;
 494
 495                         n = m_split(m, off, M_NOWAIT);
 496                         if (n == NULL) {
 497                                 /* m is retained by m_split */
 498                                 goto fail;
 499                         }
 500                         m_adj(n, stripsiz);
 501                         /* m_cat does not update m_pkthdr.len */
 502                         m->m_pkthdr.len += n->m_pkthdr.len;
 503                         m_cat(m, n);
 504                 }
 505 #endif
 506
 507                 if (m->m_len < sizeof(*ip)) {
 508                         m = m_pullup(m, sizeof(*ip));
 509                         if (m == NULL) {
 510                                 ipsecstat.in_inval++;
 511                                 goto fail;
 512                         }
 513                 }
 514                 ip = mtod(m, struct ip *);
 515 #ifdef IPLEN_FLIPPED
 516                 ip->ip_len = ip->ip_len - stripsiz;
 517 #else
 518                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 519 #endif
 520                 ip->ip_p = nxt;
 521                 /* forget about IP hdr checksum, the check has already been passed */
 522
 523                 key_sa_recordxfer(sav, m);
 524                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 525                         ipsecstat.in_nomem++;
 526                         goto fail;
 527                 }
 528
 529                 if (nxt != IPPROTO_DONE) {
 530                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) &&
 531                             ipsec4_in_reject(m, NULL)) {
 532                                 ipsecstat.in_polvio++;
 533                                 goto fail;
 534                         }
 535                         if (!ip_lengthcheck(&m, 0)) {
 536                                 /* freed in ip_lengthcheck() */
 537                                 goto fail;
 538                         }
 539                         *mp = m;
 540                         *offp = off;
 541                         (*inetsw[ip_protox[nxt]].pr_input)(mp, offp, nxt);
 542                 } else {
 543                         m_freem(m);
 544                 }
 545                 m = NULL;
 546         }
 547
 548         if (sav) {
 549                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 550                         kprintf("DP ah4_input call free SA:%p\n", sav));
 551                 key_freesav(sav);
 552         }
 553         ipsecstat.in_success++;
 554         return(IPPROTO_DONE);
 555
 556 fail:
 557         if (sav) {
 558                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 559                         kprintf("DP ah4_input call free SA:%p\n", sav));
 560                 key_freesav(sav);
 561         }
 562         if (m)
 563                 m_freem(m);
 564         return(IPPROTO_DONE);
 565 }
 566 #endif /* INET */
 567
 568 #ifdef INET6
 569 int
 570 ah6_input(struct mbuf **mp, int *offp, int proto)
 571 {
 572         struct mbuf *m = *mp;
 573         int off = *offp;
 574         struct ip6_hdr *ip6;
 575         struct ah *ah;
 576         u_int32_t spi;
 577         const struct ah_algorithm *algo;
 578         size_t siz;
 579         size_t siz1;
 580         u_char *cksum;
 581         struct secasvar *sav = NULL;
 582         u_int16_t nxt;
 583         size_t stripsiz = 0;
 584
 585 #ifndef PULLDOWN_TEST
 586         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
 587         ah = (struct ah *)(mtod(m, caddr_t) + off);
 588 #else
 589         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 590         if (ah == NULL) {
 591                 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
 592                 ipsec6stat.in_inval++;
 593                 return IPPROTO_DONE;
 594         }
 595 #endif
 596         ip6 = mtod(m, struct ip6_hdr *);
 597         nxt = ah->ah_nxt;
 598
 599         /* find the sassoc. */
 600         spi = ah->ah_spi;
 601
 602         if (ntohs(ip6->ip6_plen) == 0) {
 603                 ipseclog((LOG_ERR, "IPv6 AH input: "
 604                     "AH with IPv6 jumbogram is not supported.\n"));
 605                 ipsec6stat.in_inval++;
 606                 goto fail;
 607         }
 608
 609         if ((sav = key_allocsa(AF_INET6,
 610                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 611                               IPPROTO_AH, spi)) == NULL) {
 612                 ipseclog((LOG_WARNING,
 613                     "IPv6 AH input: no key association found for spi %u\n",
 614                     (u_int32_t)ntohl(spi)));
 615                 ipsec6stat.in_nosa++;
 616                 goto fail;
 617         }
 618         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 619                 kprintf("DP ah6_input called to allocate SA:%p\n", sav));
 620         if (sav->state != SADB_SASTATE_MATURE
 621          && sav->state != SADB_SASTATE_DYING) {
 622                 ipseclog((LOG_DEBUG,
 623                     "IPv6 AH input: non-mature/dying SA found for spi %u; ",
 624                     (u_int32_t)ntohl(spi)));
 625                 ipsec6stat.in_badspi++;
 626                 goto fail;
 627         }
 628
 629         algo = ah_algorithm_lookup(sav->alg_auth);
 630         if (!algo) {
 631                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 632                     "unsupported authentication algorithm for spi %u\n",
 633                     (u_int32_t)ntohl(spi)));
 634                 ipsec6stat.in_badspi++;
 635                 goto fail;
 636         }
 637
 638         siz = (*algo->sumsiz)(sav);
 639         siz1 = ((siz + 3) & ~(4 - 1));
 640
 641         /*
 642          * sanity checks for header, 1.
 643          */
 644     {
 645         int sizoff;
 646
 647         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 648
 649         /*
 650          * Here, we do not do "siz1 == siz".  See ah4_input() for complete
 651          * description.
 652          */
 653         if (siz1 < siz) {
 654                 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
 655                     "(%lu, should be at least %lu): %s\n",
 656                     (u_long)siz1, (u_long)siz,
 657                     ipsec6_logpacketstr(ip6, spi)));
 658                 ipsec6stat.in_inval++;
 659                 goto fail;
 660         }
 661         if ((ah->ah_len << 2) - sizoff != siz1) {
 662                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
 663                     "(%d should be %lu): %s\n",
 664                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 665                     ipsec6_logpacketstr(ip6, spi)));
 666                 ipsec6stat.in_inval++;
 667                 goto fail;
 668         }
 669 #ifndef PULLDOWN_TEST
 670         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
 671 #else
 672         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 673                 sizeof(struct ah) + sizoff + siz1);
 674         if (ah == NULL) {
 675                 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
 676                 ipsec6stat.in_inval++;
 677                 m = NULL;
 678                 goto fail;
 679         }
 680 #endif
 681     }
 682
 683         /*
 684          * check for sequence number.
 685          */
 686         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 687                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 688                         ; /* okey */
 689                 else {
 690                         ipsec6stat.in_ahreplay++;
 691                         ipseclog((LOG_WARNING,
 692                             "replay packet in IPv6 AH input: %s %s\n",
 693                             ipsec6_logpacketstr(ip6, spi),
 694                             ipsec_logsastr(sav)));
 695                         goto fail;
 696                 }
 697         }
 698
 699         /*
 700          * alright, it seems sane.  now we are going to check the
 701          * cryptographic checksum.
 702          */
 703         cksum = kmalloc(siz1, M_TEMP, M_NOWAIT);
 704         if (!cksum) {
 705                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 706                     "couldn't alloc temporary region for cksum\n"));
 707                 ipsec6stat.in_inval++;
 708                 goto fail;
 709         }
 710
 711         if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 712                 kfree(cksum, M_TEMP);
 713                 ipsec6stat.in_inval++;
 714                 goto fail;
 715         }
 716         ipsec6stat.in_ahhist[sav->alg_auth]++;
 717
 718     {
 719         caddr_t sumpos = NULL;
 720
 721         if (sav->flags & SADB_X_EXT_OLD) {
 722                 /* RFC 1826 */
 723                 sumpos = (caddr_t)(ah + 1);
 724         } else {
 725                 /* RFC 2402 */
 726                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 727         }
 728
 729         if (bcmp(sumpos, cksum, siz) != 0) {
 730                 ipseclog((LOG_WARNING,
 731                     "checksum mismatch in IPv6 AH input: %s %s\n",
 732                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 733                 kfree(cksum, M_TEMP);
 734                 ipsec6stat.in_ahauthfail++;
 735                 goto fail;
 736         }
 737     }
 738
 739         kfree(cksum, M_TEMP);
 740
 741         m->m_flags |= M_AUTHIPHDR;
 742         m->m_flags |= M_AUTHIPDGM;
 743
 744 #if 0
 745         /*
 746          * looks okey, but we need more sanity check.
 747          * XXX should elaborate.
 748          */
 749         if (ah->ah_nxt == IPPROTO_IPV6) {
 750                 struct ip6_hdr *nip6;
 751                 size_t sizoff;
 752
 753                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 754
 755                 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
 756                                 + sizeof(struct ip6_hdr), IPPROTO_DONE);
 757
 758                 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
 759                 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
 760                  || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
 761                         m->m_flags &= ~M_AUTHIPHDR;
 762                         m->m_flags &= ~M_AUTHIPDGM;
 763                 }
 764         } else if (ah->ah_nxt == IPPROTO_IPIP) {
 765                 m->m_flags &= ~M_AUTHIPHDR;
 766                 m->m_flags &= ~M_AUTHIPDGM;
 767         } else if (ah->ah_nxt == IPPROTO_IP) {
 768                 m->m_flags &= ~M_AUTHIPHDR;
 769                 m->m_flags &= ~M_AUTHIPDGM;
 770         }
 771 #endif
 772
 773         if (m->m_flags & M_AUTHIPHDR
 774          && m->m_flags & M_AUTHIPDGM) {
 775 #if 0
 776                 ipseclog((LOG_DEBUG,
 777                     "IPv6 AH input: authentication succeess\n"));
 778 #endif
 779                 ipsec6stat.in_ahauthsucc++;
 780         } else {
 781                 ipseclog((LOG_WARNING,
 782                     "authentication failed in IPv6 AH input: %s %s\n",
 783                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 784                 ipsec6stat.in_ahauthfail++;
 785                 goto fail;
 786         }
 787
 788         /*
 789          * update sequence number.
 790          */
 791         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 792                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 793                         ipsec6stat.in_ahreplay++;
 794                         goto fail;
 795                 }
 796         }
 797
 798         /* was it transmitted over the IPsec tunnel SA? */
 799         if (sav->flags & SADB_X_EXT_OLD) {
 800                 /* RFC 1826 */
 801                 stripsiz = sizeof(struct ah) + siz1;
 802         } else {
 803                 /* RFC 2402 */
 804                 stripsiz = sizeof(struct newah) + siz1;
 805         }
 806         if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 807                 /*
 808                  * strip off all the headers that precedes AH.
 809                  *      IP6 xx AH IP6' payload -> IP6' payload
 810                  *
 811                  * XXX more sanity checks
 812                  * XXX relationship with gif?
 813                  */
 814                 u_int32_t flowinfo;     /* net endian */
 815
 816                 flowinfo = ip6->ip6_flow;
 817                 m_adj(m, off + stripsiz);
 818                 if (m->m_len < sizeof(*ip6)) {
 819                         /*
 820                          * m_pullup is prohibited in KAME IPv6 input processing
 821                          * but there's no other way!
 822                          */
 823                         m = m_pullup(m, sizeof(*ip6));
 824                         if (!m) {
 825                                 ipsec6stat.in_inval++;
 826                                 goto fail;
 827                         }
 828                 }
 829                 ip6 = mtod(m, struct ip6_hdr *);
 830                 /* ECN consideration. */
 831                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 832                 if (!key_checktunnelsanity(sav, AF_INET6,
 833                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 834                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 835                             "in IPv6 AH input: %s %s\n",
 836                             ipsec6_logpacketstr(ip6, spi),
 837                             ipsec_logsastr(sav)));
 838                         ipsec6stat.in_inval++;
 839                         goto fail;
 840                 }
 841
 842 #if 1
 843                 /*
 844                  * should the inner packet be considered authentic?
 845                  * see comment in ah4_input().
 846                  */
 847                 m->m_flags &= ~M_AUTHIPHDR;
 848                 m->m_flags &= ~M_AUTHIPDGM;
 849 #endif
 850
 851                 key_sa_recordxfer(sav, m);
 852                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 853                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 854                         ipsec6stat.in_nomem++;
 855                         goto fail;
 856                 }
 857
 858                 if (netisr_queue(NETISR_IPV6, m)) {
 859                         ipsec6stat.in_inval++;
 860                         m = NULL;
 861                         goto fail;
 862                 }
 863
 864                 nxt = IPPROTO_DONE;
 865         } else {
 866                 /*
 867                  * strip off AH.
 868                  */
 869                 char *prvnxtp;
 870
 871                 /*
 872                  * Copy the value of the next header field of AH to the
 873                  * next header field of the previous header.
 874                  * This is necessary because AH will be stripped off below.
 875                  */
 876                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 877                 *prvnxtp = nxt;
 878
 879                 ip6 = mtod(m, struct ip6_hdr *);
 880 #ifndef PULLDOWN_TEST
 881                 /*
 882                  * We do deep-copy since KAME requires that
 883                  * the packet is placed in a single mbuf.
 884                  */
 885                 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 886                 m->m_data += stripsiz;
 887                 m->m_len -= stripsiz;
 888                 m->m_pkthdr.len -= stripsiz;
 889 #else
 890                 /*
 891                  * even in m_pulldown case, we need to strip off AH so that
 892                  * we can compute checksum for multiple AH correctly.
 893                  */
 894                 if (m->m_len >= stripsiz + off) {
 895                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 896                         m->m_data += stripsiz;
 897                         m->m_len -= stripsiz;
 898                         m->m_pkthdr.len -= stripsiz;
 899                 } else {
 900                         /*
 901                          * this comes with no copy if the boundary is on
 902                          * cluster
 903                          */
 904                         struct mbuf *n;
 905
 906                         n = m_split(m, off, M_NOWAIT);
 907                         if (n == NULL) {
 908                                 /* m is retained by m_split */
 909                                 goto fail;
 910                         }
 911                         m_adj(n, stripsiz);
 912                         /* m_cat does not update m_pkthdr.len */
 913                         m->m_pkthdr.len += n->m_pkthdr.len;
 914                         m_cat(m, n);
 915                 }
 916 #endif
 917                 ip6 = mtod(m, struct ip6_hdr *);
 918                 /* XXX jumbogram */
 919                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 920
 921                 key_sa_recordxfer(sav, m);
 922                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 923                         ipsec6stat.in_nomem++;
 924                         goto fail;
 925                 }
 926         }
 927
 928         *offp = off;
 929         *mp = m;
 930
 931         if (sav) {
 932                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 933                         kprintf("DP ah6_input call free SA:%p\n", sav));
 934                 key_freesav(sav);
 935         }
 936         ipsec6stat.in_success++;
 937         return nxt;
 938
 939 fail:
 940         if (sav) {
 941                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 942                         kprintf("DP ah6_input call free SA:%p\n", sav));
 943                 key_freesav(sav);
 944         }
 945         if (m)
 946                 m_freem(m);
 947         return IPPROTO_DONE;
 948 }
 949
 950 void
 951 ah6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 952 {
 953         const struct newah *ahp;
 954         struct newah ah;
 955         struct secasvar *sav;
 956         struct ip6_hdr *ip6;
 957         struct mbuf *m;
 958         struct ip6ctlparam *ip6cp = NULL;
 959         int off;
 960         struct sockaddr_in6 *sa6_src, *sa6_dst;
 961
 962         if (sa->sa_family != AF_INET6 ||
 963             sa->sa_len != sizeof(struct sockaddr_in6))
 964                 return;
 965         if ((unsigned)cmd >= PRC_NCMDS)
 966                 return;
 967
 968         /* if the parameter is from icmp6, decode it. */
 969         if (d != NULL) {
 970                 ip6cp = (struct ip6ctlparam *)d;
 971                 m = ip6cp->ip6c_m;
 972                 ip6 = ip6cp->ip6c_ip6;
 973                 off = ip6cp->ip6c_off;
 974         } else {
 975                 m = NULL;
 976                 ip6 = NULL;
 977                 off = 0; /* fix warning */
 978         }
 979
 980         if (ip6) {
 981                 /*
 982                  * XXX: We assume that when ip6 is non NULL,
 983                  * M and OFF are valid.
 984                  */
 985
 986                 /* check if we can safely examine src and dst ports */
 987                 if (m->m_pkthdr.len < off + sizeof(ah))
 988                         return;
 989
 990                 if (m->m_len < off + sizeof(ah)) {
 991                         /*
 992                          * this should be rare case,
 993                          * so we compromise on this copy...
 994                          */
 995                         m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
 996                         ahp = &ah;
 997                 } else
 998                         ahp = (struct newah *)(mtod(m, caddr_t) + off);
 999
1000                 if (cmd == PRC_MSGSIZE) {
1001                         int valid = 0;
1002
1003                         /*
1004                          * Check to see if we have a valid SA corresponding to
1005                          * the address in the ICMP message payload.
1006                          */
1007                         sa6_src = ip6cp->ip6c_src;
1008                         sa6_dst = (struct sockaddr_in6 *)sa;
1009                         sav = key_allocsa(AF_INET6,
1010                                           (caddr_t)&sa6_src->sin6_addr,
1011                                           (caddr_t)&sa6_dst->sin6_addr,
1012                                           IPPROTO_AH, ahp->ah_spi);
1013                         if (sav) {
1014                                 if (sav->state == SADB_SASTATE_MATURE ||
1015                                     sav->state == SADB_SASTATE_DYING)
1016                                         valid++;
1017                                 key_freesav(sav);
1018                         }
1019
1020                         /* XXX Further validation? */
1021
1022                         /*
1023                          * Depending on the value of "valid" and routing table
1024                          * size (mtudisc_{hi,lo}wat), we will:
1025                          * - recalcurate the new MTU and create the
1026                          *   corresponding routing entry, or
1027                          * - ignore the MTU change notification.
1028                          */
1029                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1030                 }
1031
1032                 /* we normally notify single pcb here */
1033         } else {
1034                 /* we normally notify any pcb here */
1035         }
1036 }
1037 #endif /* INET6 */