sys/netinet6/ah_input.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: ah_input.c,v 1.59 2001/05/16 04:01:27 jinmei 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
  56 #include <netinet/in.h>
  57 #include <netinet/in_systm.h>
  58 #include <netinet/in_var.h>
  59 #include <netinet/ip.h>
  60 #include <netinet/ip_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/ip6_var.h>
  69 #include <netinet6/in6_pcb.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 <netkey/key.h>
  83 #include <netkey/keydb.h>
  84 #ifdef IPSEC_DEBUG
  85 #include <netkey/key_debug.h>
  86 #else
  87 #define KEYDEBUG(lev,arg)
  88 #endif
  89
  90 #include <machine/stdarg.h>
  91
  92 #include <net/net_osdep.h>
  93
  94 #define IPLEN_FLIPPED
  95
  96 #ifdef INET
  97 extern struct protosw inetsw[];
  98
  99 void
 100 ah4_input(m, off)
 101         struct mbuf *m;
 102         int off;
 103 {
 104         struct ip *ip;
 105         struct ah *ah;
 106         u_int32_t spi;
 107         const struct ah_algorithm *algo;
 108         size_t siz;
 109         size_t siz1;
 110         u_char *cksum;
 111         struct secasvar *sav = NULL;
 112         u_int16_t nxt;
 113         size_t hlen;
 114         int proto;
 115         size_t stripsiz = 0;
 116
 117 #ifndef PULLDOWN_TEST
 118         if (m->m_len < off + sizeof(struct newah)) {
 119                 m = m_pullup(m, off + sizeof(struct newah));
 120                 if (!m) {
 121                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 122                                 "dropping the packet for simplicity\n"));
 123                         ipsecstat.in_inval++;
 124                         goto fail;
 125                 }
 126         }
 127
 128         ip = mtod(m, struct ip *);
 129         proto = ip->ip_p;
 130         ah = (struct ah *)(((caddr_t)ip) + off);
 131 #else
 132         ip = mtod(m, struct ip *);
 133         proto = ip->ip_p;
 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)) == 0) {
 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                 printf("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 = malloc(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                 free(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                 free(cksum, M_TEMP);
 314                 ipsecstat.in_ahauthfail++;
 315                 goto fail;
 316         }
 317     }
 318
 319         free(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 0 /* XXX should we call ipfw rather than ipsec_in_reject? */
 426                 /* drop it if it does not match the default policy */
 427                 if (ipsec4_in_reject(m, NULL)) {
 428                         ipsecstat.in_polvio++;
 429                         goto fail;
 430                 }
 431 #endif
 432
 433 #if 1
 434                 /*
 435                  * Should the inner packet be considered authentic?
 436                  * My current answer is: NO.
 437                  *
 438                  * host1 -- gw1 === gw2 -- host2
 439                  *      In this case, gw2 can trust the authenticity of the
 440                  *      outer packet, but NOT inner.  Packet may be altered
 441                  *      between host1 and gw1.
 442                  *
 443                  * host1 -- gw1 === host2
 444                  *      This case falls into the same scenario as above.
 445                  *
 446                  * host1 === host2
 447                  *      This case is the only case when we may be able to leave
 448                  *      M_AUTHIPHDR and M_AUTHIPDGM set.
 449                  *      However, if host1 is wrongly configured, and allows
 450                  *      attacker to inject some packet with src=host1 and
 451                  *      dst=host2, you are in risk.
 452                  */
 453                 m->m_flags &= ~M_AUTHIPHDR;
 454                 m->m_flags &= ~M_AUTHIPDGM;
 455 #endif
 456
 457                 key_sa_recordxfer(sav, m);
 458                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 459                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 460                         ipsecstat.in_nomem++;
 461                         goto fail;
 462                 }
 463
 464                 if (! IF_HANDOFF(&ipintrq, m, NULL)) {
 465                         ipsecstat.in_inval++;
 466                         m = NULL;
 467                         goto fail;
 468                 }
 469                 m = NULL;
 470                 schednetisr(NETISR_IP); /*can be skipped but to make sure*/
 471                 nxt = IPPROTO_DONE;
 472         } else {
 473                 /*
 474                  * strip off AH.
 475                  */
 476
 477                 ip = mtod(m, struct ip *);
 478 #ifndef PULLDOWN_TEST
 479                 /*
 480                  * We do deep-copy since KAME requires that
 481                  * the packet is placed in a single external mbuf.
 482                  */
 483                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 484                 m->m_data += stripsiz;
 485                 m->m_len -= stripsiz;
 486                 m->m_pkthdr.len -= stripsiz;
 487 #else
 488                 /*
 489                  * even in m_pulldown case, we need to strip off AH so that
 490                  * we can compute checksum for multiple AH correctly.
 491                  */
 492                 if (m->m_len >= stripsiz + off) {
 493                         ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
 494                         m->m_data += stripsiz;
 495                         m->m_len -= stripsiz;
 496                         m->m_pkthdr.len -= stripsiz;
 497                 } else {
 498                         /*
 499                          * this comes with no copy if the boundary is on
 500                          * cluster
 501                          */
 502                         struct mbuf *n;
 503
 504                         n = m_split(m, off, M_DONTWAIT);
 505                         if (n == NULL) {
 506                                 /* m is retained by m_split */
 507                                 goto fail;
 508                         }
 509                         m_adj(n, stripsiz);
 510                         m_cat(m, n);
 511                         /* m_cat does not update m_pkthdr.len */
 512                         m->m_pkthdr.len += n->m_pkthdr.len;
 513                 }
 514 #endif
 515
 516                 if (m->m_len < sizeof(*ip)) {
 517                         m = m_pullup(m, sizeof(*ip));
 518                         if (m == NULL) {
 519                                 ipsecstat.in_inval++;
 520                                 goto fail;
 521                         }
 522                 }
 523                 ip = mtod(m, struct ip *);
 524 #ifdef IPLEN_FLIPPED
 525                 ip->ip_len = ip->ip_len - stripsiz;
 526 #else
 527                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 528 #endif
 529                 ip->ip_p = nxt;
 530                 /* forget about IP hdr checksum, the check has already been passed */
 531
 532                 key_sa_recordxfer(sav, m);
 533                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 534                         ipsecstat.in_nomem++;
 535                         goto fail;
 536                 }
 537
 538                 if (nxt != IPPROTO_DONE) {
 539                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 540                             ipsec4_in_reject(m, NULL)) {
 541                                 ipsecstat.in_polvio++;
 542                                 goto fail;
 543                         }
 544                         (*inetsw[ip_protox[nxt]].pr_input)(m, off);
 545                 } else
 546                         m_freem(m);
 547                 m = NULL;
 548         }
 549
 550         if (sav) {
 551                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 552                         printf("DP ah4_input call free SA:%p\n", sav));
 553                 key_freesav(sav);
 554         }
 555         ipsecstat.in_success++;
 556         return;
 557
 558 fail:
 559         if (sav) {
 560                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 561                         printf("DP ah4_input call free SA:%p\n", sav));
 562                 key_freesav(sav);
 563         }
 564         if (m)
 565                 m_freem(m);
 566         return;
 567 }
 568 #endif /* INET */
 569
 570 #ifdef INET6
 571 int
 572 ah6_input(mp, offp, proto)
 573         struct mbuf **mp;
 574         int *offp, proto;
 575 {
 576         struct mbuf *m = *mp;
 577         int off = *offp;
 578         struct ip6_hdr *ip6;
 579         struct ah *ah;
 580         u_int32_t spi;
 581         const struct ah_algorithm *algo;
 582         size_t siz;
 583         size_t siz1;
 584         u_char *cksum;
 585         struct secasvar *sav = NULL;
 586         u_int16_t nxt;
 587         size_t stripsiz = 0;
 588
 589 #ifndef PULLDOWN_TEST
 590         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
 591         ah = (struct ah *)(mtod(m, caddr_t) + off);
 592 #else
 593         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 594         if (ah == NULL) {
 595                 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
 596                 ipsec6stat.in_inval++;
 597                 return IPPROTO_DONE;
 598         }
 599 #endif
 600         ip6 = mtod(m, struct ip6_hdr *);
 601         nxt = ah->ah_nxt;
 602
 603         /* find the sassoc.  */
 604         spi = ah->ah_spi;
 605
 606         if (ntohs(ip6->ip6_plen) == 0) {
 607                 ipseclog((LOG_ERR, "IPv6 AH input: "
 608                     "AH with IPv6 jumbogram is not supported.\n"));
 609                 ipsec6stat.in_inval++;
 610                 goto fail;
 611         }
 612
 613         if ((sav = key_allocsa(AF_INET6,
 614                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 615                               IPPROTO_AH, spi)) == 0) {
 616                 ipseclog((LOG_WARNING,
 617                     "IPv6 AH input: no key association found for spi %u\n",
 618                     (u_int32_t)ntohl(spi)));
 619                 ipsec6stat.in_nosa++;
 620                 goto fail;
 621         }
 622         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 623                 printf("DP ah6_input called to allocate SA:%p\n", sav));
 624         if (sav->state != SADB_SASTATE_MATURE
 625          && sav->state != SADB_SASTATE_DYING) {
 626                 ipseclog((LOG_DEBUG,
 627                     "IPv6 AH input: non-mature/dying SA found for spi %u; ",
 628                     (u_int32_t)ntohl(spi)));
 629                 ipsec6stat.in_badspi++;
 630                 goto fail;
 631         }
 632
 633         algo = ah_algorithm_lookup(sav->alg_auth);
 634         if (!algo) {
 635                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 636                     "unsupported authentication algorithm for spi %u\n",
 637                     (u_int32_t)ntohl(spi)));
 638                 ipsec6stat.in_badspi++;
 639                 goto fail;
 640         }
 641
 642         siz = (*algo->sumsiz)(sav);
 643         siz1 = ((siz + 3) & ~(4 - 1));
 644
 645         /*
 646          * sanity checks for header, 1.
 647          */
 648     {
 649         int sizoff;
 650
 651         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 652
 653         /*
 654          * Here, we do not do "siz1 == siz".  See ah4_input() for complete
 655          * description.
 656          */
 657         if (siz1 < siz) {
 658                 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
 659                     "(%lu, should be at least %lu): %s\n",
 660                     (u_long)siz1, (u_long)siz,
 661                     ipsec6_logpacketstr(ip6, spi)));
 662                 ipsec6stat.in_inval++;
 663                 goto fail;
 664         }
 665         if ((ah->ah_len << 2) - sizoff != siz1) {
 666                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
 667                     "(%d should be %lu): %s\n",
 668                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 669                     ipsec6_logpacketstr(ip6, spi)));
 670                 ipsec6stat.in_inval++;
 671                 goto fail;
 672         }
 673 #ifndef PULLDOWN_TEST
 674         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
 675 #else
 676         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 677                 sizeof(struct ah) + sizoff + siz1);
 678         if (ah == NULL) {
 679                 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
 680                 ipsec6stat.in_inval++;
 681                 m = NULL;
 682                 goto fail;
 683         }
 684 #endif
 685     }
 686
 687         /*
 688          * check for sequence number.
 689          */
 690         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 691                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 692                         ; /*okey*/
 693                 else {
 694                         ipsec6stat.in_ahreplay++;
 695                         ipseclog((LOG_WARNING,
 696                             "replay packet in IPv6 AH input: %s %s\n",
 697                             ipsec6_logpacketstr(ip6, spi),
 698                             ipsec_logsastr(sav)));
 699                         goto fail;
 700                 }
 701         }
 702
 703         /*
 704          * alright, it seems sane.  now we are going to check the
 705          * cryptographic checksum.
 706          */
 707         cksum = malloc(siz1, M_TEMP, M_NOWAIT);
 708         if (!cksum) {
 709                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 710                     "couldn't alloc temporary region for cksum\n"));
 711                 ipsec6stat.in_inval++;
 712                 goto fail;
 713         }
 714
 715         if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 716                 free(cksum, M_TEMP);
 717                 ipsec6stat.in_inval++;
 718                 goto fail;
 719         }
 720         ipsec6stat.in_ahhist[sav->alg_auth]++;
 721
 722     {
 723         caddr_t sumpos = NULL;
 724
 725         if (sav->flags & SADB_X_EXT_OLD) {
 726                 /* RFC 1826 */
 727                 sumpos = (caddr_t)(ah + 1);
 728         } else {
 729                 /* RFC 2402 */
 730                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 731         }
 732
 733         if (bcmp(sumpos, cksum, siz) != 0) {
 734                 ipseclog((LOG_WARNING,
 735                     "checksum mismatch in IPv6 AH input: %s %s\n",
 736                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 737                 free(cksum, M_TEMP);
 738                 ipsec6stat.in_ahauthfail++;
 739                 goto fail;
 740         }
 741     }
 742
 743         free(cksum, M_TEMP);
 744
 745         m->m_flags |= M_AUTHIPHDR;
 746         m->m_flags |= M_AUTHIPDGM;
 747
 748 #if 0
 749         /*
 750          * looks okey, but we need more sanity check.
 751          * XXX should elaborate.
 752          */
 753         if (ah->ah_nxt == IPPROTO_IPV6) {
 754                 struct ip6_hdr *nip6;
 755                 size_t sizoff;
 756
 757                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 758
 759                 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
 760                                 + sizeof(struct ip6_hdr), IPPROTO_DONE);
 761
 762                 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
 763                 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
 764                  || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
 765                         m->m_flags &= ~M_AUTHIPHDR;
 766                         m->m_flags &= ~M_AUTHIPDGM;
 767                 }
 768         } else if (ah->ah_nxt == IPPROTO_IPIP) {
 769                 m->m_flags &= ~M_AUTHIPHDR;
 770                 m->m_flags &= ~M_AUTHIPDGM;
 771         } else if (ah->ah_nxt == IPPROTO_IP) {
 772                 m->m_flags &= ~M_AUTHIPHDR;
 773                 m->m_flags &= ~M_AUTHIPDGM;
 774         }
 775 #endif
 776
 777         if (m->m_flags & M_AUTHIPHDR
 778          && m->m_flags & M_AUTHIPDGM) {
 779 #if 0
 780                 ipseclog((LOG_DEBUG,
 781                     "IPv6 AH input: authentication succeess\n"));
 782 #endif
 783                 ipsec6stat.in_ahauthsucc++;
 784         } else {
 785                 ipseclog((LOG_WARNING,
 786                     "authentication failed in IPv6 AH input: %s %s\n",
 787                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 788                 ipsec6stat.in_ahauthfail++;
 789                 goto fail;
 790         }
 791
 792         /*
 793          * update sequence number.
 794          */
 795         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 796                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 797                         ipsec6stat.in_ahreplay++;
 798                         goto fail;
 799                 }
 800         }
 801
 802         /* was it transmitted over the IPsec tunnel SA? */
 803         if (sav->flags & SADB_X_EXT_OLD) {
 804                 /* RFC 1826 */
 805                 stripsiz = sizeof(struct ah) + siz1;
 806         } else {
 807                 /* RFC 2402 */
 808                 stripsiz = sizeof(struct newah) + siz1;
 809         }
 810         if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 811                 /*
 812                  * strip off all the headers that precedes AH.
 813                  *      IP6 xx AH IP6' payload -> IP6' payload
 814                  *
 815                  * XXX more sanity checks
 816                  * XXX relationship with gif?
 817                  */
 818                 u_int32_t flowinfo;     /*net endian*/
 819
 820                 flowinfo = ip6->ip6_flow;
 821                 m_adj(m, off + stripsiz);
 822                 if (m->m_len < sizeof(*ip6)) {
 823                         /*
 824                          * m_pullup is prohibited in KAME IPv6 input processing
 825                          * but there's no other way!
 826                          */
 827                         m = m_pullup(m, sizeof(*ip6));
 828                         if (!m) {
 829                                 ipsec6stat.in_inval++;
 830                                 goto fail;
 831                         }
 832                 }
 833                 ip6 = mtod(m, struct ip6_hdr *);
 834                 /* ECN consideration. */
 835                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 836                 if (!key_checktunnelsanity(sav, AF_INET6,
 837                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 838                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 839                             "in IPv6 AH input: %s %s\n",
 840                             ipsec6_logpacketstr(ip6, spi),
 841                             ipsec_logsastr(sav)));
 842                         ipsec6stat.in_inval++;
 843                         goto fail;
 844                 }
 845
 846 #if 0 /* XXX should we call ipfw rather than ipsec_in_reject? */
 847                 /* drop it if it does not match the default policy */
 848                 if (ipsec6_in_reject(m, NULL)) {
 849                         ipsec6stat.in_polvio++;
 850                         goto fail;
 851                 }
 852 #endif
 853
 854 #if 1
 855                 /*
 856                  * should the inner packet be considered authentic?
 857                  * see comment in ah4_input().
 858                  */
 859                 m->m_flags &= ~M_AUTHIPHDR;
 860                 m->m_flags &= ~M_AUTHIPDGM;
 861 #endif
 862
 863                 key_sa_recordxfer(sav, m);
 864                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 865                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 866                         ipsec6stat.in_nomem++;
 867                         goto fail;
 868                 }
 869
 870                 if (! IF_HANDOFF(&ip6intrq, m, NULL)) {
 871                         ipsec6stat.in_inval++;
 872                         m = NULL;
 873                         goto fail;
 874                 }
 875                 m = NULL;
 876                 schednetisr(NETISR_IPV6); /*can be skipped but to make sure*/
 877                 nxt = IPPROTO_DONE;
 878         } else {
 879                 /*
 880                  * strip off AH.
 881                  */
 882                 char *prvnxtp;
 883
 884                 /*
 885                  * Copy the value of the next header field of AH to the
 886                  * next header field of the previous header.
 887                  * This is necessary because AH will be stripped off below.
 888                  */
 889                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 890                 *prvnxtp = nxt;
 891
 892                 ip6 = mtod(m, struct ip6_hdr *);
 893 #ifndef PULLDOWN_TEST
 894                 /*
 895                  * We do deep-copy since KAME requires that
 896                  * the packet is placed in a single mbuf.
 897                  */
 898                 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 899                 m->m_data += stripsiz;
 900                 m->m_len -= stripsiz;
 901                 m->m_pkthdr.len -= stripsiz;
 902 #else
 903                 /*
 904                  * even in m_pulldown case, we need to strip off AH so that
 905                  * we can compute checksum for multiple AH correctly.
 906                  */
 907                 if (m->m_len >= stripsiz + off) {
 908                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 909                         m->m_data += stripsiz;
 910                         m->m_len -= stripsiz;
 911                         m->m_pkthdr.len -= stripsiz;
 912                 } else {
 913                         /*
 914                          * this comes with no copy if the boundary is on
 915                          * cluster
 916                          */
 917                         struct mbuf *n;
 918
 919                         n = m_split(m, off, M_DONTWAIT);
 920                         if (n == NULL) {
 921                                 /* m is retained by m_split */
 922                                 goto fail;
 923                         }
 924                         m_adj(n, stripsiz);
 925                         m_cat(m, n);
 926                         /* m_cat does not update m_pkthdr.len */
 927                         m->m_pkthdr.len += n->m_pkthdr.len;
 928                 }
 929 #endif
 930                 ip6 = mtod(m, struct ip6_hdr *);
 931                 /* XXX jumbogram */
 932                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 933
 934                 key_sa_recordxfer(sav, m);
 935                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 936                         ipsec6stat.in_nomem++;
 937                         goto fail;
 938                 }
 939         }
 940
 941         *offp = off;
 942         *mp = m;
 943
 944         if (sav) {
 945                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 946                         printf("DP ah6_input call free SA:%p\n", sav));
 947                 key_freesav(sav);
 948         }
 949         ipsec6stat.in_success++;
 950         return nxt;
 951
 952 fail:
 953         if (sav) {
 954                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 955                         printf("DP ah6_input call free SA:%p\n", sav));
 956                 key_freesav(sav);
 957         }
 958         if (m)
 959                 m_freem(m);
 960         return IPPROTO_DONE;
 961 }
 962
 963 void
 964 ah6_ctlinput(cmd, sa, d)
 965         int cmd;
 966         struct sockaddr *sa;
 967         void *d;
 968 {
 969         const struct newah *ahp;
 970         struct newah ah;
 971         struct secasvar *sav;
 972         struct ip6_hdr *ip6;
 973         struct mbuf *m;
 974         struct ip6ctlparam *ip6cp = NULL;
 975         int off;
 976         struct sockaddr_in6 sa6_src, sa6_dst;
 977
 978         if (sa->sa_family != AF_INET6 ||
 979             sa->sa_len != sizeof(struct sockaddr_in6))
 980                 return;
 981         if ((unsigned)cmd >= PRC_NCMDS)
 982                 return;
 983
 984         /* if the parameter is from icmp6, decode it. */
 985         if (d != NULL) {
 986                 ip6cp = (struct ip6ctlparam *)d;
 987                 m = ip6cp->ip6c_m;
 988                 ip6 = ip6cp->ip6c_ip6;
 989                 off = ip6cp->ip6c_off;
 990         } else {
 991                 m = NULL;
 992                 ip6 = NULL;
 993         }
 994
 995         if (ip6) {
 996                 /*
 997                  * XXX: We assume that when ip6 is non NULL,
 998                  * M and OFF are valid.
 999                  */
1000
1001                 /* check if we can safely examine src and dst ports */
1002                 if (m->m_pkthdr.len < off + sizeof(ah))
1003                         return;
1004
1005                 if (m->m_len < off + sizeof(ah)) {
1006                         /*
1007                          * this should be rare case,
1008                          * so we compromise on this copy...
1009                          */
1010                         m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
1011                         ahp = &ah;
1012                 } else
1013                         ahp = (struct newah *)(mtod(m, caddr_t) + off);
1014
1015                 if (cmd == PRC_MSGSIZE) {
1016                         int valid = 0;
1017
1018                         /*
1019                          * Check to see if we have a valid SA corresponding to
1020                          * the address in the ICMP message payload.
1021                          */
1022                         sav = key_allocsa(AF_INET6,
1023                                           (caddr_t)&sa6_src.sin6_addr,
1024                                           (caddr_t)&sa6_dst.sin6_addr,
1025                                           IPPROTO_AH, ahp->ah_spi);
1026                         if (sav) {
1027                                 if (sav->state == SADB_SASTATE_MATURE ||
1028                                     sav->state == SADB_SASTATE_DYING)
1029                                         valid++;
1030                                 key_freesav(sav);
1031                         }
1032
1033                         /* XXX Further validation? */
1034
1035                         /*
1036                          * Depending on the value of "valid" and routing table
1037                          * size (mtudisc_{hi,lo}wat), we will:
1038                          * - recalcurate the new MTU and create the
1039                          *   corresponding routing entry, or
1040                          * - ignore the MTU change notification.
1041                          */
1042                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1043                 }
1044
1045                 /* we normally notify single pcb here */
1046         } else {
1047                 /* we normally notify any pcb here */
1048         }
1049 }
1050 #endif /* INET6 */