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 /*      $DragonFly: src/sys/netinet6/ah_input.c,v 1.8 2004/06/03 18:30:04 joerg Exp $   */
   3 /*      $KAME: ah_input.c,v 1.67 2002/01/07 11:39:56 kjc Exp $  */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * RFC1826/2402 authentication header.
  36  */
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/malloc.h>
  44 #include <sys/mbuf.h>
  45 #include <sys/domain.h>
  46 #include <sys/protosw.h>
  47 #include <sys/socket.h>
  48 #include <sys/errno.h>
  49 #include <sys/time.h>
  50 #include <sys/syslog.h>
  51
  52 #include <net/if.h>
  53 #include <net/route.h>
  54 #include <net/netisr.h>
  55 #include <machine/cpu.h>
  56 #include <machine/stdarg.h>
  57
  58 #include <netinet/in.h>
  59 #include <netinet/in_systm.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip.h>
  62 #include <netinet/ip_var.h>
  63 #include <netinet/ip_ecn.h>
  64 #ifdef INET6
  65 #include <netinet6/ip6_ecn.h>
  66 #endif
  67
  68 #ifdef INET6
  69 #include <netinet/ip6.h>
  70 #include <netinet6/ip6_var.h>
  71 #include <netinet6/in6_pcb.h>
  72 #include <netinet/icmp6.h>
  73 #include <netinet6/ip6protosw.h>
  74 #endif
  75
  76 #include <netinet6/ipsec.h>
  77 #ifdef INET6
  78 #include <netinet6/ipsec6.h>
  79 #endif
  80 #include <netinet6/ah.h>
  81 #ifdef INET6
  82 #include <netinet6/ah6.h>
  83 #endif
  84 #include <netproto/key/key.h>
  85 #include <netproto/key/keydb.h>
  86 #ifdef IPSEC_DEBUG
  87 #include <netproto/key/key_debug.h>
  88 #else
  89 #define KEYDEBUG(lev,arg)
  90 #endif
  91
  92 #include <machine/stdarg.h>
  93
  94 #include <net/net_osdep.h>
  95
  96 #define IPLEN_FLIPPED
  97
  98 #ifdef INET
  99 #include <netinet/ipprotosw.h>
 100 extern struct ipprotosw inetsw[];
 101
 102 void
 103 ah4_input(struct mbuf *m, ...)
 104 {
 105         int off, proto;
 106         struct ip *ip;
 107         struct ah *ah;
 108         u_int32_t spi;
 109         const struct ah_algorithm *algo;
 110         size_t siz;
 111         size_t siz1;
 112         u_char *cksum;
 113         struct secasvar *sav = NULL;
 114         u_int16_t nxt;
 115         size_t hlen;
 116         size_t stripsiz = 0;
 117         __va_list ap;
 118
 119         __va_start(ap, m);
 120         off = __va_arg(ap, int);
 121         proto = __va_arg(ap, int);
 122         __va_end(ap);
 123
 124 #ifndef PULLDOWN_TEST
 125         if (m->m_len < off + sizeof(struct newah)) {
 126                 m = m_pullup(m, off + sizeof(struct newah));
 127                 if (!m) {
 128                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 129                                 "dropping the packet for simplicity\n"));
 130                         ipsecstat.in_inval++;
 131                         goto fail;
 132                 }
 133         }
 134
 135         ip = mtod(m, struct ip *);
 136         ah = (struct ah *)(((caddr_t)ip) + off);
 137 #else
 138         ip = mtod(m, struct ip *);
 139         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 140         if (ah == NULL) {
 141                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 142                         "dropping the packet for simplicity\n"));
 143                 ipsecstat.in_inval++;
 144                 goto fail;
 145         }
 146 #endif
 147         nxt = ah->ah_nxt;
 148 #ifdef _IP_VHL
 149         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 150 #else
 151         hlen = ip->ip_hl << 2;
 152 #endif
 153
 154         /* find the sassoc. */
 155         spi = ah->ah_spi;
 156
 157         if ((sav = key_allocsa(AF_INET,
 158                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 159                               IPPROTO_AH, spi)) == 0) {
 160                 ipseclog((LOG_WARNING,
 161                     "IPv4 AH input: no key association found for spi %u\n",
 162                     (u_int32_t)ntohl(spi)));
 163                 ipsecstat.in_nosa++;
 164                 goto fail;
 165         }
 166         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 167                 printf("DP ah4_input called to allocate SA:%p\n", sav));
 168         if (sav->state != SADB_SASTATE_MATURE
 169          && sav->state != SADB_SASTATE_DYING) {
 170                 ipseclog((LOG_DEBUG,
 171                     "IPv4 AH input: non-mature/dying SA found for spi %u\n",
 172                     (u_int32_t)ntohl(spi)));
 173                 ipsecstat.in_badspi++;
 174                 goto fail;
 175         }
 176
 177         algo = ah_algorithm_lookup(sav->alg_auth);
 178         if (!algo) {
 179                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 180                     "unsupported authentication algorithm for spi %u\n",
 181                     (u_int32_t)ntohl(spi)));
 182                 ipsecstat.in_badspi++;
 183                 goto fail;
 184         }
 185
 186         siz = (*algo->sumsiz)(sav);
 187         siz1 = ((siz + 3) & ~(4 - 1));
 188
 189         /*
 190          * sanity checks for header, 1.
 191          */
 192     {
 193         int sizoff;
 194
 195         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 196
 197         /*
 198          * Here, we do not do "siz1 == siz".  This is because the way
 199          * RFC240[34] section 2 is written.  They do not require truncation
 200          * to 96 bits.
 201          * For example, Microsoft IPsec stack attaches 160 bits of
 202          * authentication data for both hmac-md5 and hmac-sha1.  For hmac-sha1,
 203          * 32 bits of padding is attached.
 204          *
 205          * There are two downsides to this specification.
 206          * They have no real harm, however, they leave us fuzzy feeling.
 207          * - if we attach more than 96 bits of authentication data onto AH,
 208          *   we will never notice about possible modification by rogue
 209          *   intermediate nodes.
 210          *   Since extra bits in AH checksum is never used, this constitutes
 211          *   no real issue, however, it is wacky.
 212          * - even if the peer attaches big authentication data, we will never
 213          *   notice the difference, since longer authentication data will just
 214          *   work.
 215          *
 216          * We may need some clarification in the spec.
 217          */
 218         if (siz1 < siz) {
 219                 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
 220                     "(%lu, should be at least %lu): %s\n",
 221                     (u_long)siz1, (u_long)siz,
 222                     ipsec4_logpacketstr(ip, spi)));
 223                 ipsecstat.in_inval++;
 224                 goto fail;
 225         }
 226         if ((ah->ah_len << 2) - sizoff != siz1) {
 227                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
 228                     "(%d should be %lu): %s\n",
 229                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 230                     ipsec4_logpacketstr(ip, spi)));
 231                 ipsecstat.in_inval++;
 232                 goto fail;
 233         }
 234
 235 #ifndef PULLDOWN_TEST
 236         if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
 237                 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
 238                 if (!m) {
 239                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 240                         ipsecstat.in_inval++;
 241                         goto fail;
 242                 }
 243
 244                 ip = mtod(m, struct ip *);
 245                 ah = (struct ah *)(((caddr_t)ip) + off);
 246         }
 247 #else
 248         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 249                 sizeof(struct ah) + sizoff + siz1);
 250         if (ah == NULL) {
 251                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 252                 ipsecstat.in_inval++;
 253                 goto fail;
 254         }
 255 #endif
 256     }
 257
 258         /*
 259          * check for sequence number.
 260          */
 261         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 262                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 263                         ; /* okey */
 264                 else {
 265                         ipsecstat.in_ahreplay++;
 266                         ipseclog((LOG_WARNING,
 267                             "replay packet in IPv4 AH input: %s %s\n",
 268                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 269                         goto fail;
 270                 }
 271         }
 272
 273         /*
 274          * alright, it seems sane.  now we are going to check the
 275          * cryptographic checksum.
 276          */
 277         cksum = malloc(siz1, M_TEMP, M_NOWAIT);
 278         if (!cksum) {
 279                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 280                     "couldn't alloc temporary region for cksum\n"));
 281                 ipsecstat.in_inval++;
 282                 goto fail;
 283         }
 284
 285         /*
 286          * some of IP header fields are flipped to the host endian.
 287          * convert them back to network endian.  VERY stupid.
 288          */
 289         ip->ip_len = htons(ip->ip_len + hlen);
 290         ip->ip_off = htons(ip->ip_off);
 291         if (ah4_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 292                 free(cksum, M_TEMP);
 293                 ipsecstat.in_inval++;
 294                 goto fail;
 295         }
 296         ipsecstat.in_ahhist[sav->alg_auth]++;
 297         /*
 298          * flip them back.
 299          */
 300         ip->ip_len = ntohs(ip->ip_len) - hlen;
 301         ip->ip_off = ntohs(ip->ip_off);
 302
 303     {
 304         caddr_t sumpos = NULL;
 305
 306         if (sav->flags & SADB_X_EXT_OLD) {
 307                 /* RFC 1826 */
 308                 sumpos = (caddr_t)(ah + 1);
 309         } else {
 310                 /* RFC 2402 */
 311                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 312         }
 313
 314         if (bcmp(sumpos, cksum, siz) != 0) {
 315                 ipseclog((LOG_WARNING,
 316                     "checksum mismatch in IPv4 AH input: %s %s\n",
 317                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 318                 free(cksum, M_TEMP);
 319                 ipsecstat.in_ahauthfail++;
 320                 goto fail;
 321         }
 322     }
 323
 324         free(cksum, M_TEMP);
 325
 326         m->m_flags |= M_AUTHIPHDR;
 327         m->m_flags |= M_AUTHIPDGM;
 328
 329 #if 0
 330         /*
 331          * looks okey, but we need more sanity check.
 332          * XXX should elaborate.
 333          */
 334         if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
 335                 struct ip *nip;
 336                 size_t sizoff;
 337
 338                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 339
 340                 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
 341                         m = m_pullup(m, off + sizeof(struct ah)
 342                                         + sizoff + siz1 + hlen);
 343                         if (!m) {
 344                                 ipseclog((LOG_DEBUG,
 345                                     "IPv4 AH input: can't pullup\n"));
 346                                 ipsecstat.in_inval++;
 347                                 goto fail;
 348                         }
 349                 }
 350
 351                 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
 352                 if (nip->ip_src.s_addr != ip->ip_src.s_addr
 353                  || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
 354                         m->m_flags &= ~M_AUTHIPHDR;
 355                         m->m_flags &= ~M_AUTHIPDGM;
 356                 }
 357         }
 358 #ifdef INET6
 359         else if (ah->ah_nxt == IPPROTO_IPV6) {
 360                 m->m_flags &= ~M_AUTHIPHDR;
 361                 m->m_flags &= ~M_AUTHIPDGM;
 362         }
 363 #endif /* INET6 */
 364 #endif /* 0 */
 365
 366         if (m->m_flags & M_AUTHIPHDR
 367          && m->m_flags & M_AUTHIPDGM) {
 368 #if 0
 369                 ipseclog((LOG_DEBUG,
 370                     "IPv4 AH input: authentication succeess\n"));
 371 #endif
 372                 ipsecstat.in_ahauthsucc++;
 373         } else {
 374                 ipseclog((LOG_WARNING,
 375                     "authentication failed in IPv4 AH input: %s %s\n",
 376                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 377                 ipsecstat.in_ahauthfail++;
 378                 goto fail;
 379         }
 380
 381         /*
 382          * update sequence number.
 383          */
 384         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 385                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 386                         ipsecstat.in_ahreplay++;
 387                         goto fail;
 388                 }
 389         }
 390
 391         /* was it transmitted over the IPsec tunnel SA? */
 392         if (sav->flags & SADB_X_EXT_OLD) {
 393                 /* RFC 1826 */
 394                 stripsiz = sizeof(struct ah) + siz1;
 395         } else {
 396                 /* RFC 2402 */
 397                 stripsiz = sizeof(struct newah) + siz1;
 398         }
 399         if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 400                 /*
 401                  * strip off all the headers that precedes AH.
 402                  *      IP xx AH IP' payload -> IP' payload
 403                  *
 404                  * XXX more sanity checks
 405                  * XXX relationship with gif?
 406                  */
 407                 u_int8_t tos;
 408
 409                 tos = ip->ip_tos;
 410                 m_adj(m, off + stripsiz);
 411                 if (m->m_len < sizeof(*ip)) {
 412                         m = m_pullup(m, sizeof(*ip));
 413                         if (!m) {
 414                                 ipsecstat.in_inval++;
 415                                 goto fail;
 416                         }
 417                 }
 418                 ip = mtod(m, struct ip *);
 419                 /* ECN consideration. */
 420                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 421                 if (!key_checktunnelsanity(sav, AF_INET,
 422                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 423                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 424                             "in IPv4 AH input: %s %s\n",
 425                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 426                         ipsecstat.in_inval++;
 427                         goto fail;
 428                 }
 429
 430 #if 1
 431                 /*
 432                  * Should the inner packet be considered authentic?
 433                  * My current answer is: NO.
 434                  *
 435                  * host1 -- gw1 === gw2 -- host2
 436                  *      In this case, gw2 can trust the authenticity of the
 437                  *      outer packet, but NOT inner.  Packet may be altered
 438                  *      between host1 and gw1.
 439                  *
 440                  * host1 -- gw1 === host2
 441                  *      This case falls into the same scenario as above.
 442                  *
 443                  * host1 === host2
 444                  *      This case is the only case when we may be able to leave
 445                  *      M_AUTHIPHDR and M_AUTHIPDGM set.
 446                  *      However, if host1 is wrongly configured, and allows
 447                  *      attacker to inject some packet with src=host1 and
 448                  *      dst=host2, you are in risk.
 449                  */
 450                 m->m_flags &= ~M_AUTHIPHDR;
 451                 m->m_flags &= ~M_AUTHIPDGM;
 452 #endif
 453
 454                 key_sa_recordxfer(sav, m);
 455                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 456                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 457                         ipsecstat.in_nomem++;
 458                         goto fail;
 459                 }
 460
 461                 if (netisr_queue(NETISR_IP, m)) {
 462                         ipsecstat.in_inval++;
 463                         m = NULL;
 464                         goto fail;
 465                 }
 466
 467                 nxt = IPPROTO_DONE;
 468         } else {
 469                 /*
 470                  * strip off AH.
 471                  */
 472
 473                 ip = mtod(m, struct ip *);
 474 #ifndef PULLDOWN_TEST
 475                 /*
 476                  * We do deep-copy since KAME requires that
 477                  * the packet is placed in a single external mbuf.
 478                  */
 479                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 480                 m->m_data += stripsiz;
 481                 m->m_len -= stripsiz;
 482                 m->m_pkthdr.len -= stripsiz;
 483 #else
 484                 /*
 485                  * even in m_pulldown case, we need to strip off AH so that
 486                  * we can compute checksum for multiple AH correctly.
 487                  */
 488                 if (m->m_len >= stripsiz + off) {
 489                         ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
 490                         m->m_data += stripsiz;
 491                         m->m_len -= stripsiz;
 492                         m->m_pkthdr.len -= stripsiz;
 493                 } else {
 494                         /*
 495                          * this comes with no copy if the boundary is on
 496                          * cluster
 497                          */
 498                         struct mbuf *n;
 499
 500                         n = m_split(m, off, MB_DONTWAIT);
 501                         if (n == NULL) {
 502                                 /* m is retained by m_split */
 503                                 goto fail;
 504                         }
 505                         m_adj(n, stripsiz);
 506                         m_cat(m, n);
 507                         /* m_cat does not update m_pkthdr.len */
 508                         m->m_pkthdr.len += n->m_pkthdr.len;
 509                 }
 510 #endif
 511
 512                 if (m->m_len < sizeof(*ip)) {
 513                         m = m_pullup(m, sizeof(*ip));
 514                         if (m == NULL) {
 515                                 ipsecstat.in_inval++;
 516                                 goto fail;
 517                         }
 518                 }
 519                 ip = mtod(m, struct ip *);
 520 #ifdef IPLEN_FLIPPED
 521                 ip->ip_len = ip->ip_len - stripsiz;
 522 #else
 523                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 524 #endif
 525                 ip->ip_p = nxt;
 526                 /* forget about IP hdr checksum, the check has already been passed */
 527
 528                 key_sa_recordxfer(sav, m);
 529                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 530                         ipsecstat.in_nomem++;
 531                         goto fail;
 532                 }
 533
 534                 if (nxt != IPPROTO_DONE) {
 535                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 536                             ipsec4_in_reject(m, NULL)) {
 537                                 ipsecstat.in_polvio++;
 538                                 goto fail;
 539                         }
 540                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 541                 } else
 542                         m_freem(m);
 543                 m = NULL;
 544         }
 545
 546         if (sav) {
 547                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 548                         printf("DP ah4_input call free SA:%p\n", sav));
 549                 key_freesav(sav);
 550         }
 551         ipsecstat.in_success++;
 552         return;
 553
 554 fail:
 555         if (sav) {
 556                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 557                         printf("DP ah4_input call free SA:%p\n", sav));
 558                 key_freesav(sav);
 559         }
 560         if (m)
 561                 m_freem(m);
 562         return;
 563 }
 564 #endif /* INET */
 565
 566 #ifdef INET6
 567 int
 568 ah6_input(struct mbuf **mp, int *offp, int proto)
 569 {
 570         struct mbuf *m = *mp;
 571         int off = *offp;
 572         struct ip6_hdr *ip6;
 573         struct ah *ah;
 574         u_int32_t spi;
 575         const struct ah_algorithm *algo;
 576         size_t siz;
 577         size_t siz1;
 578         u_char *cksum;
 579         struct secasvar *sav = NULL;
 580         u_int16_t nxt;
 581         size_t stripsiz = 0;
 582
 583 #ifndef PULLDOWN_TEST
 584         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
 585         ah = (struct ah *)(mtod(m, caddr_t) + off);
 586 #else
 587         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 588         if (ah == NULL) {
 589                 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
 590                 ipsec6stat.in_inval++;
 591                 return IPPROTO_DONE;
 592         }
 593 #endif
 594         ip6 = mtod(m, struct ip6_hdr *);
 595         nxt = ah->ah_nxt;
 596
 597         /* find the sassoc. */
 598         spi = ah->ah_spi;
 599
 600         if (ntohs(ip6->ip6_plen) == 0) {
 601                 ipseclog((LOG_ERR, "IPv6 AH input: "
 602                     "AH with IPv6 jumbogram is not supported.\n"));
 603                 ipsec6stat.in_inval++;
 604                 goto fail;
 605         }
 606
 607         if ((sav = key_allocsa(AF_INET6,
 608                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 609                               IPPROTO_AH, spi)) == 0) {
 610                 ipseclog((LOG_WARNING,
 611                     "IPv6 AH input: no key association found for spi %u\n",
 612                     (u_int32_t)ntohl(spi)));
 613                 ipsec6stat.in_nosa++;
 614                 goto fail;
 615         }
 616         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 617                 printf("DP ah6_input called to allocate SA:%p\n", sav));
 618         if (sav->state != SADB_SASTATE_MATURE
 619          && sav->state != SADB_SASTATE_DYING) {
 620                 ipseclog((LOG_DEBUG,
 621                     "IPv6 AH input: non-mature/dying SA found for spi %u; ",
 622                     (u_int32_t)ntohl(spi)));
 623                 ipsec6stat.in_badspi++;
 624                 goto fail;
 625         }
 626
 627         algo = ah_algorithm_lookup(sav->alg_auth);
 628         if (!algo) {
 629                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 630                     "unsupported authentication algorithm for spi %u\n",
 631                     (u_int32_t)ntohl(spi)));
 632                 ipsec6stat.in_badspi++;
 633                 goto fail;
 634         }
 635
 636         siz = (*algo->sumsiz)(sav);
 637         siz1 = ((siz + 3) & ~(4 - 1));
 638
 639         /*
 640          * sanity checks for header, 1.
 641          */
 642     {
 643         int sizoff;
 644
 645         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 646
 647         /*
 648          * Here, we do not do "siz1 == siz".  See ah4_input() for complete
 649          * description.
 650          */
 651         if (siz1 < siz) {
 652                 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
 653                     "(%lu, should be at least %lu): %s\n",
 654                     (u_long)siz1, (u_long)siz,
 655                     ipsec6_logpacketstr(ip6, spi)));
 656                 ipsec6stat.in_inval++;
 657                 goto fail;
 658         }
 659         if ((ah->ah_len << 2) - sizoff != siz1) {
 660                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
 661                     "(%d should be %lu): %s\n",
 662                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 663                     ipsec6_logpacketstr(ip6, spi)));
 664                 ipsec6stat.in_inval++;
 665                 goto fail;
 666         }
 667 #ifndef PULLDOWN_TEST
 668         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
 669 #else
 670         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 671                 sizeof(struct ah) + sizoff + siz1);
 672         if (ah == NULL) {
 673                 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
 674                 ipsec6stat.in_inval++;
 675                 m = NULL;
 676                 goto fail;
 677         }
 678 #endif
 679     }
 680
 681         /*
 682          * check for sequence number.
 683          */
 684         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 685                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 686                         ; /* okey */
 687                 else {
 688                         ipsec6stat.in_ahreplay++;
 689                         ipseclog((LOG_WARNING,
 690                             "replay packet in IPv6 AH input: %s %s\n",
 691                             ipsec6_logpacketstr(ip6, spi),
 692                             ipsec_logsastr(sav)));
 693                         goto fail;
 694                 }
 695         }
 696
 697         /*
 698          * alright, it seems sane.  now we are going to check the
 699          * cryptographic checksum.
 700          */
 701         cksum = malloc(siz1, M_TEMP, M_NOWAIT);
 702         if (!cksum) {
 703                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 704                     "couldn't alloc temporary region for cksum\n"));
 705                 ipsec6stat.in_inval++;
 706                 goto fail;
 707         }
 708
 709         if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 710                 free(cksum, M_TEMP);
 711                 ipsec6stat.in_inval++;
 712                 goto fail;
 713         }
 714         ipsec6stat.in_ahhist[sav->alg_auth]++;
 715
 716     {
 717         caddr_t sumpos = NULL;
 718
 719         if (sav->flags & SADB_X_EXT_OLD) {
 720                 /* RFC 1826 */
 721                 sumpos = (caddr_t)(ah + 1);
 722         } else {
 723                 /* RFC 2402 */
 724                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 725         }
 726
 727         if (bcmp(sumpos, cksum, siz) != 0) {
 728                 ipseclog((LOG_WARNING,
 729                     "checksum mismatch in IPv6 AH input: %s %s\n",
 730                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 731                 free(cksum, M_TEMP);
 732                 ipsec6stat.in_ahauthfail++;
 733                 goto fail;
 734         }
 735     }
 736
 737         free(cksum, M_TEMP);
 738
 739         m->m_flags |= M_AUTHIPHDR;
 740         m->m_flags |= M_AUTHIPDGM;
 741
 742 #if 0
 743         /*
 744          * looks okey, but we need more sanity check.
 745          * XXX should elaborate.
 746          */
 747         if (ah->ah_nxt == IPPROTO_IPV6) {
 748                 struct ip6_hdr *nip6;
 749                 size_t sizoff;
 750
 751                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 752
 753                 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
 754                                 + sizeof(struct ip6_hdr), IPPROTO_DONE);
 755
 756                 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
 757                 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
 758                  || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
 759                         m->m_flags &= ~M_AUTHIPHDR;
 760                         m->m_flags &= ~M_AUTHIPDGM;
 761                 }
 762         } else if (ah->ah_nxt == IPPROTO_IPIP) {
 763                 m->m_flags &= ~M_AUTHIPHDR;
 764                 m->m_flags &= ~M_AUTHIPDGM;
 765         } else if (ah->ah_nxt == IPPROTO_IP) {
 766                 m->m_flags &= ~M_AUTHIPHDR;
 767                 m->m_flags &= ~M_AUTHIPDGM;
 768         }
 769 #endif
 770
 771         if (m->m_flags & M_AUTHIPHDR
 772          && m->m_flags & M_AUTHIPDGM) {
 773 #if 0
 774                 ipseclog((LOG_DEBUG,
 775                     "IPv6 AH input: authentication succeess\n"));
 776 #endif
 777                 ipsec6stat.in_ahauthsucc++;
 778         } else {
 779                 ipseclog((LOG_WARNING,
 780                     "authentication failed in IPv6 AH input: %s %s\n",
 781                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 782                 ipsec6stat.in_ahauthfail++;
 783                 goto fail;
 784         }
 785
 786         /*
 787          * update sequence number.
 788          */
 789         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 790                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 791                         ipsec6stat.in_ahreplay++;
 792                         goto fail;
 793                 }
 794         }
 795
 796         /* was it transmitted over the IPsec tunnel SA? */
 797         if (sav->flags & SADB_X_EXT_OLD) {
 798                 /* RFC 1826 */
 799                 stripsiz = sizeof(struct ah) + siz1;
 800         } else {
 801                 /* RFC 2402 */
 802                 stripsiz = sizeof(struct newah) + siz1;
 803         }
 804         if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 805                 /*
 806                  * strip off all the headers that precedes AH.
 807                  *      IP6 xx AH IP6' payload -> IP6' payload
 808                  *
 809                  * XXX more sanity checks
 810                  * XXX relationship with gif?
 811                  */
 812                 u_int32_t flowinfo;     /* net endian */
 813
 814                 flowinfo = ip6->ip6_flow;
 815                 m_adj(m, off + stripsiz);
 816                 if (m->m_len < sizeof(*ip6)) {
 817                         /*
 818                          * m_pullup is prohibited in KAME IPv6 input processing
 819                          * but there's no other way!
 820                          */
 821                         m = m_pullup(m, sizeof(*ip6));
 822                         if (!m) {
 823                                 ipsec6stat.in_inval++;
 824                                 goto fail;
 825                         }
 826                 }
 827                 ip6 = mtod(m, struct ip6_hdr *);
 828                 /* ECN consideration. */
 829                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 830                 if (!key_checktunnelsanity(sav, AF_INET6,
 831                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 832                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 833                             "in IPv6 AH input: %s %s\n",
 834                             ipsec6_logpacketstr(ip6, spi),
 835                             ipsec_logsastr(sav)));
 836                         ipsec6stat.in_inval++;
 837                         goto fail;
 838                 }
 839
 840 #if 1
 841                 /*
 842                  * should the inner packet be considered authentic?
 843                  * see comment in ah4_input().
 844                  */
 845                 m->m_flags &= ~M_AUTHIPHDR;
 846                 m->m_flags &= ~M_AUTHIPDGM;
 847 #endif
 848
 849                 key_sa_recordxfer(sav, m);
 850                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 851                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 852                         ipsec6stat.in_nomem++;
 853                         goto fail;
 854                 }
 855
 856                 if (netisr_queue(NETISR_IPV6, m)) {
 857                         ipsecstat.in_inval++;
 858                         m = NULL;
 859                         goto fail;
 860                 }
 861
 862                 nxt = IPPROTO_DONE;
 863         } else {
 864                 /*
 865                  * strip off AH.
 866                  */
 867                 char *prvnxtp;
 868
 869                 /*
 870                  * Copy the value of the next header field of AH to the
 871                  * next header field of the previous header.
 872                  * This is necessary because AH will be stripped off below.
 873                  */
 874                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 875                 *prvnxtp = nxt;
 876
 877                 ip6 = mtod(m, struct ip6_hdr *);
 878 #ifndef PULLDOWN_TEST
 879                 /*
 880                  * We do deep-copy since KAME requires that
 881                  * the packet is placed in a single mbuf.
 882                  */
 883                 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 884                 m->m_data += stripsiz;
 885                 m->m_len -= stripsiz;
 886                 m->m_pkthdr.len -= stripsiz;
 887 #else
 888                 /*
 889                  * even in m_pulldown case, we need to strip off AH so that
 890                  * we can compute checksum for multiple AH correctly.
 891                  */
 892                 if (m->m_len >= stripsiz + off) {
 893                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 894                         m->m_data += stripsiz;
 895                         m->m_len -= stripsiz;
 896                         m->m_pkthdr.len -= stripsiz;
 897                 } else {
 898                         /*
 899                          * this comes with no copy if the boundary is on
 900                          * cluster
 901                          */
 902                         struct mbuf *n;
 903
 904                         n = m_split(m, off, MB_DONTWAIT);
 905                         if (n == NULL) {
 906                                 /* m is retained by m_split */
 907                                 goto fail;
 908                         }
 909                         m_adj(n, stripsiz);
 910                         m_cat(m, n);
 911                         /* m_cat does not update m_pkthdr.len */
 912                         m->m_pkthdr.len += n->m_pkthdr.len;
 913                 }
 914 #endif
 915                 ip6 = mtod(m, struct ip6_hdr *);
 916                 /* XXX jumbogram */
 917                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 918
 919                 key_sa_recordxfer(sav, m);
 920                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 921                         ipsec6stat.in_nomem++;
 922                         goto fail;
 923                 }
 924         }
 925
 926         *offp = off;
 927         *mp = m;
 928
 929         if (sav) {
 930                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 931                         printf("DP ah6_input call free SA:%p\n", sav));
 932                 key_freesav(sav);
 933         }
 934         ipsec6stat.in_success++;
 935         return nxt;
 936
 937 fail:
 938         if (sav) {
 939                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 940                         printf("DP ah6_input call free SA:%p\n", sav));
 941                 key_freesav(sav);
 942         }
 943         if (m)
 944                 m_freem(m);
 945         return IPPROTO_DONE;
 946 }
 947
 948 void
 949 ah6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 950 {
 951         const struct newah *ahp;
 952         struct newah ah;
 953         struct secasvar *sav;
 954         struct ip6_hdr *ip6;
 955         struct mbuf *m;
 956         struct ip6ctlparam *ip6cp = NULL;
 957         int off;
 958         struct sockaddr_in6 *sa6_src, *sa6_dst;
 959
 960         if (sa->sa_family != AF_INET6 ||
 961             sa->sa_len != sizeof(struct sockaddr_in6))
 962                 return;
 963         if ((unsigned)cmd >= PRC_NCMDS)
 964                 return;
 965
 966         /* if the parameter is from icmp6, decode it. */
 967         if (d != NULL) {
 968                 ip6cp = (struct ip6ctlparam *)d;
 969                 m = ip6cp->ip6c_m;
 970                 ip6 = ip6cp->ip6c_ip6;
 971                 off = ip6cp->ip6c_off;
 972         } else {
 973                 m = NULL;
 974                 ip6 = NULL;
 975                 off = 0; /* fix warning */
 976         }
 977
 978         if (ip6) {
 979                 /*
 980                  * XXX: We assume that when ip6 is non NULL,
 981                  * M and OFF are valid.
 982                  */
 983
 984                 /* check if we can safely examine src and dst ports */
 985                 if (m->m_pkthdr.len < off + sizeof(ah))
 986                         return;
 987
 988                 if (m->m_len < off + sizeof(ah)) {
 989                         /*
 990                          * this should be rare case,
 991                          * so we compromise on this copy...
 992                          */
 993                         m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
 994                         ahp = &ah;
 995                 } else
 996                         ahp = (struct newah *)(mtod(m, caddr_t) + off);
 997
 998                 if (cmd == PRC_MSGSIZE) {
 999                         int valid = 0;
1000
1001                         /*
1002                          * Check to see if we have a valid SA corresponding to
1003                          * the address in the ICMP message payload.
1004                          */
1005                         sa6_src = ip6cp->ip6c_src;
1006                         sa6_dst = (struct sockaddr_in6 *)sa;
1007                         sav = key_allocsa(AF_INET6,
1008                                           (caddr_t)&sa6_src->sin6_addr,
1009                                           (caddr_t)&sa6_dst->sin6_addr,
1010                                           IPPROTO_AH, ahp->ah_spi);
1011                         if (sav) {
1012                                 if (sav->state == SADB_SASTATE_MATURE ||
1013                                     sav->state == SADB_SASTATE_DYING)
1014                                         valid++;
1015                                 key_freesav(sav);
1016                         }
1017
1018                         /* XXX Further validation? */
1019
1020                         /*
1021                          * Depending on the value of "valid" and routing table
1022                          * size (mtudisc_{hi,lo}wat), we will:
1023                          * - recalcurate the new MTU and create the
1024                          *   corresponding routing entry, or
1025                          * - ignore the MTU change notification.
1026                          */
1027                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1028                 }
1029
1030                 /* we normally notify single pcb here */
1031         } else {
1032                 /* we normally notify any pcb here */
1033         }
1034 }
1035 #endif /* INET6 */