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 1.2 2003/06/17 04:28:51 dillon 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
  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 <netkey/key.h>
  84 #include <netkey/keydb.h>
  85 #ifdef IPSEC_DEBUG
  86 #include <netkey/key_debug.h>
  87 #else
  88 #define KEYDEBUG(lev,arg)
  89 #endif
  90
  91 #include <machine/stdarg.h>
  92
  93 #include <net/net_osdep.h>
  94
  95 #define IPLEN_FLIPPED
  96
  97 #ifdef INET
  98 #include <netinet/ipprotosw.h>
  99 extern struct ipprotosw inetsw[];
 100
 101 void
 102 #if __STDC__
 103 ah4_input(struct mbuf *m, ...)
 104 #else
 105 ah4_input(m, va_alist)
 106         struct mbuf *m;
 107         va_dcl
 108 #endif
 109 {
 110         struct ip *ip;
 111         struct ah *ah;
 112         u_int32_t spi;
 113         const struct ah_algorithm *algo;
 114         size_t siz;
 115         size_t siz1;
 116         u_char *cksum;
 117         struct secasvar *sav = NULL;
 118         u_int16_t nxt;
 119         size_t hlen;
 120         int s;
 121         int off, proto;
 122         va_list ap;
 123         size_t stripsiz = 0;
 124
 125         va_start(ap, m);
 126         off = va_arg(ap, int);
 127         proto = va_arg(ap, int);
 128         va_end(ap);
 129
 130 #ifndef PULLDOWN_TEST
 131         if (m->m_len < off + sizeof(struct newah)) {
 132                 m = m_pullup(m, off + sizeof(struct newah));
 133                 if (!m) {
 134                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 135                                 "dropping the packet for simplicity\n"));
 136                         ipsecstat.in_inval++;
 137                         goto fail;
 138                 }
 139         }
 140
 141         ip = mtod(m, struct ip *);
 142         ah = (struct ah *)(((caddr_t)ip) + off);
 143 #else
 144         ip = mtod(m, struct ip *);
 145         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 146         if (ah == NULL) {
 147                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup;"
 148                         "dropping the packet for simplicity\n"));
 149                 ipsecstat.in_inval++;
 150                 goto fail;
 151         }
 152 #endif
 153         nxt = ah->ah_nxt;
 154 #ifdef _IP_VHL
 155         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
 156 #else
 157         hlen = ip->ip_hl << 2;
 158 #endif
 159
 160         /* find the sassoc. */
 161         spi = ah->ah_spi;
 162
 163         if ((sav = key_allocsa(AF_INET,
 164                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
 165                               IPPROTO_AH, spi)) == 0) {
 166                 ipseclog((LOG_WARNING,
 167                     "IPv4 AH input: no key association found for spi %u\n",
 168                     (u_int32_t)ntohl(spi)));
 169                 ipsecstat.in_nosa++;
 170                 goto fail;
 171         }
 172         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 173                 printf("DP ah4_input called to allocate SA:%p\n", sav));
 174         if (sav->state != SADB_SASTATE_MATURE
 175          && sav->state != SADB_SASTATE_DYING) {
 176                 ipseclog((LOG_DEBUG,
 177                     "IPv4 AH input: non-mature/dying SA found for spi %u\n",
 178                     (u_int32_t)ntohl(spi)));
 179                 ipsecstat.in_badspi++;
 180                 goto fail;
 181         }
 182
 183         algo = ah_algorithm_lookup(sav->alg_auth);
 184         if (!algo) {
 185                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 186                     "unsupported authentication algorithm for spi %u\n",
 187                     (u_int32_t)ntohl(spi)));
 188                 ipsecstat.in_badspi++;
 189                 goto fail;
 190         }
 191
 192         siz = (*algo->sumsiz)(sav);
 193         siz1 = ((siz + 3) & ~(4 - 1));
 194
 195         /*
 196          * sanity checks for header, 1.
 197          */
 198     {
 199         int sizoff;
 200
 201         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 202
 203         /*
 204          * Here, we do not do "siz1 == siz".  This is because the way
 205          * RFC240[34] section 2 is written.  They do not require truncation
 206          * to 96 bits.
 207          * For example, Microsoft IPsec stack attaches 160 bits of
 208          * authentication data for both hmac-md5 and hmac-sha1.  For hmac-sha1,
 209          * 32 bits of padding is attached.
 210          *
 211          * There are two downsides to this specification.
 212          * They have no real harm, however, they leave us fuzzy feeling.
 213          * - if we attach more than 96 bits of authentication data onto AH,
 214          *   we will never notice about possible modification by rogue
 215          *   intermediate nodes.
 216          *   Since extra bits in AH checksum is never used, this constitutes
 217          *   no real issue, however, it is wacky.
 218          * - even if the peer attaches big authentication data, we will never
 219          *   notice the difference, since longer authentication data will just
 220          *   work.
 221          *
 222          * We may need some clarification in the spec.
 223          */
 224         if (siz1 < siz) {
 225                 ipseclog((LOG_NOTICE, "sum length too short in IPv4 AH input "
 226                     "(%lu, should be at least %lu): %s\n",
 227                     (u_long)siz1, (u_long)siz,
 228                     ipsec4_logpacketstr(ip, spi)));
 229                 ipsecstat.in_inval++;
 230                 goto fail;
 231         }
 232         if ((ah->ah_len << 2) - sizoff != siz1) {
 233                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv4 AH input "
 234                     "(%d should be %lu): %s\n",
 235                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 236                     ipsec4_logpacketstr(ip, spi)));
 237                 ipsecstat.in_inval++;
 238                 goto fail;
 239         }
 240
 241 #ifndef PULLDOWN_TEST
 242         if (m->m_len < off + sizeof(struct ah) + sizoff + siz1) {
 243                 m = m_pullup(m, off + sizeof(struct ah) + sizoff + siz1);
 244                 if (!m) {
 245                         ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 246                         ipsecstat.in_inval++;
 247                         goto fail;
 248                 }
 249
 250                 ip = mtod(m, struct ip *);
 251                 ah = (struct ah *)(((caddr_t)ip) + off);
 252         }
 253 #else
 254         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 255                 sizeof(struct ah) + sizoff + siz1);
 256         if (ah == NULL) {
 257                 ipseclog((LOG_DEBUG, "IPv4 AH input: can't pullup\n"));
 258                 ipsecstat.in_inval++;
 259                 goto fail;
 260         }
 261 #endif
 262     }
 263
 264         /*
 265          * check for sequence number.
 266          */
 267         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 268                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 269                         ; /* okey */
 270                 else {
 271                         ipsecstat.in_ahreplay++;
 272                         ipseclog((LOG_WARNING,
 273                             "replay packet in IPv4 AH input: %s %s\n",
 274                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 275                         goto fail;
 276                 }
 277         }
 278
 279         /*
 280          * alright, it seems sane.  now we are going to check the
 281          * cryptographic checksum.
 282          */
 283         cksum = malloc(siz1, M_TEMP, M_NOWAIT);
 284         if (!cksum) {
 285                 ipseclog((LOG_DEBUG, "IPv4 AH input: "
 286                     "couldn't alloc temporary region for cksum\n"));
 287                 ipsecstat.in_inval++;
 288                 goto fail;
 289         }
 290
 291         /*
 292          * some of IP header fields are flipped to the host endian.
 293          * convert them back to network endian.  VERY stupid.
 294          */
 295         ip->ip_len = htons(ip->ip_len + hlen);
 296         ip->ip_off = htons(ip->ip_off);
 297         if (ah4_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 298                 free(cksum, M_TEMP);
 299                 ipsecstat.in_inval++;
 300                 goto fail;
 301         }
 302         ipsecstat.in_ahhist[sav->alg_auth]++;
 303         /*
 304          * flip them back.
 305          */
 306         ip->ip_len = ntohs(ip->ip_len) - hlen;
 307         ip->ip_off = ntohs(ip->ip_off);
 308
 309     {
 310         caddr_t sumpos = NULL;
 311
 312         if (sav->flags & SADB_X_EXT_OLD) {
 313                 /* RFC 1826 */
 314                 sumpos = (caddr_t)(ah + 1);
 315         } else {
 316                 /* RFC 2402 */
 317                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 318         }
 319
 320         if (bcmp(sumpos, cksum, siz) != 0) {
 321                 ipseclog((LOG_WARNING,
 322                     "checksum mismatch in IPv4 AH input: %s %s\n",
 323                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 324                 free(cksum, M_TEMP);
 325                 ipsecstat.in_ahauthfail++;
 326                 goto fail;
 327         }
 328     }
 329
 330         free(cksum, M_TEMP);
 331
 332         m->m_flags |= M_AUTHIPHDR;
 333         m->m_flags |= M_AUTHIPDGM;
 334
 335 #if 0
 336         /*
 337          * looks okey, but we need more sanity check.
 338          * XXX should elaborate.
 339          */
 340         if (ah->ah_nxt == IPPROTO_IPIP || ah->ah_nxt == IPPROTO_IP) {
 341                 struct ip *nip;
 342                 size_t sizoff;
 343
 344                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 345
 346                 if (m->m_len < off + sizeof(struct ah) + sizoff + siz1 + hlen) {
 347                         m = m_pullup(m, off + sizeof(struct ah)
 348                                         + sizoff + siz1 + hlen);
 349                         if (!m) {
 350                                 ipseclog((LOG_DEBUG,
 351                                     "IPv4 AH input: can't pullup\n"));
 352                                 ipsecstat.in_inval++;
 353                                 goto fail;
 354                         }
 355                 }
 356
 357                 nip = (struct ip *)((u_char *)(ah + 1) + sizoff + siz1);
 358                 if (nip->ip_src.s_addr != ip->ip_src.s_addr
 359                  || nip->ip_dst.s_addr != ip->ip_dst.s_addr) {
 360                         m->m_flags &= ~M_AUTHIPHDR;
 361                         m->m_flags &= ~M_AUTHIPDGM;
 362                 }
 363         }
 364 #ifdef INET6
 365         else if (ah->ah_nxt == IPPROTO_IPV6) {
 366                 m->m_flags &= ~M_AUTHIPHDR;
 367                 m->m_flags &= ~M_AUTHIPDGM;
 368         }
 369 #endif /* INET6 */
 370 #endif /* 0 */
 371
 372         if (m->m_flags & M_AUTHIPHDR
 373          && m->m_flags & M_AUTHIPDGM) {
 374 #if 0
 375                 ipseclog((LOG_DEBUG,
 376                     "IPv4 AH input: authentication succeess\n"));
 377 #endif
 378                 ipsecstat.in_ahauthsucc++;
 379         } else {
 380                 ipseclog((LOG_WARNING,
 381                     "authentication failed in IPv4 AH input: %s %s\n",
 382                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 383                 ipsecstat.in_ahauthfail++;
 384                 goto fail;
 385         }
 386
 387         /*
 388          * update sequence number.
 389          */
 390         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 391                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 392                         ipsecstat.in_ahreplay++;
 393                         goto fail;
 394                 }
 395         }
 396
 397         /* was it transmitted over the IPsec tunnel SA? */
 398         if (sav->flags & SADB_X_EXT_OLD) {
 399                 /* RFC 1826 */
 400                 stripsiz = sizeof(struct ah) + siz1;
 401         } else {
 402                 /* RFC 2402 */
 403                 stripsiz = sizeof(struct newah) + siz1;
 404         }
 405         if (ipsec4_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 406                 /*
 407                  * strip off all the headers that precedes AH.
 408                  *      IP xx AH IP' payload -> IP' payload
 409                  *
 410                  * XXX more sanity checks
 411                  * XXX relationship with gif?
 412                  */
 413                 u_int8_t tos;
 414
 415                 tos = ip->ip_tos;
 416                 m_adj(m, off + stripsiz);
 417                 if (m->m_len < sizeof(*ip)) {
 418                         m = m_pullup(m, sizeof(*ip));
 419                         if (!m) {
 420                                 ipsecstat.in_inval++;
 421                                 goto fail;
 422                         }
 423                 }
 424                 ip = mtod(m, struct ip *);
 425                 /* ECN consideration. */
 426                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
 427                 if (!key_checktunnelsanity(sav, AF_INET,
 428                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
 429                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 430                             "in IPv4 AH input: %s %s\n",
 431                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
 432                         ipsecstat.in_inval++;
 433                         goto fail;
 434                 }
 435
 436 #if 1
 437                 /*
 438                  * Should the inner packet be considered authentic?
 439                  * My current answer is: NO.
 440                  *
 441                  * host1 -- gw1 === gw2 -- host2
 442                  *      In this case, gw2 can trust the authenticity of the
 443                  *      outer packet, but NOT inner.  Packet may be altered
 444                  *      between host1 and gw1.
 445                  *
 446                  * host1 -- gw1 === host2
 447                  *      This case falls into the same scenario as above.
 448                  *
 449                  * host1 === host2
 450                  *      This case is the only case when we may be able to leave
 451                  *      M_AUTHIPHDR and M_AUTHIPDGM set.
 452                  *      However, if host1 is wrongly configured, and allows
 453                  *      attacker to inject some packet with src=host1 and
 454                  *      dst=host2, you are in risk.
 455                  */
 456                 m->m_flags &= ~M_AUTHIPHDR;
 457                 m->m_flags &= ~M_AUTHIPDGM;
 458 #endif
 459
 460                 key_sa_recordxfer(sav, m);
 461                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 462                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
 463                         ipsecstat.in_nomem++;
 464                         goto fail;
 465                 }
 466
 467                 s = splimp();
 468                 if (IF_QFULL(&ipintrq)) {
 469                         ipsecstat.in_inval++;
 470                         splx(s);
 471                         goto fail;
 472                 }
 473                 IF_ENQUEUE(&ipintrq, m);
 474                 m = NULL;
 475                 schednetisr(NETISR_IP); /* can be skipped but to make sure */
 476                 splx(s);
 477                 nxt = IPPROTO_DONE;
 478         } else {
 479                 /*
 480                  * strip off AH.
 481                  */
 482
 483                 ip = mtod(m, struct ip *);
 484 #ifndef PULLDOWN_TEST
 485                 /*
 486                  * We do deep-copy since KAME requires that
 487                  * the packet is placed in a single external mbuf.
 488                  */
 489                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
 490                 m->m_data += stripsiz;
 491                 m->m_len -= stripsiz;
 492                 m->m_pkthdr.len -= stripsiz;
 493 #else
 494                 /*
 495                  * even in m_pulldown case, we need to strip off AH so that
 496                  * we can compute checksum for multiple AH correctly.
 497                  */
 498                 if (m->m_len >= stripsiz + off) {
 499                         ovbcopy((caddr_t)ip, ((caddr_t)ip) + stripsiz, off);
 500                         m->m_data += stripsiz;
 501                         m->m_len -= stripsiz;
 502                         m->m_pkthdr.len -= stripsiz;
 503                 } else {
 504                         /*
 505                          * this comes with no copy if the boundary is on
 506                          * cluster
 507                          */
 508                         struct mbuf *n;
 509
 510                         n = m_split(m, off, M_DONTWAIT);
 511                         if (n == NULL) {
 512                                 /* m is retained by m_split */
 513                                 goto fail;
 514                         }
 515                         m_adj(n, stripsiz);
 516                         m_cat(m, n);
 517                         /* m_cat does not update m_pkthdr.len */
 518                         m->m_pkthdr.len += n->m_pkthdr.len;
 519                 }
 520 #endif
 521
 522                 if (m->m_len < sizeof(*ip)) {
 523                         m = m_pullup(m, sizeof(*ip));
 524                         if (m == NULL) {
 525                                 ipsecstat.in_inval++;
 526                                 goto fail;
 527                         }
 528                 }
 529                 ip = mtod(m, struct ip *);
 530 #ifdef IPLEN_FLIPPED
 531                 ip->ip_len = ip->ip_len - stripsiz;
 532 #else
 533                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
 534 #endif
 535                 ip->ip_p = nxt;
 536                 /* forget about IP hdr checksum, the check has already been passed */
 537
 538                 key_sa_recordxfer(sav, m);
 539                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 540                         ipsecstat.in_nomem++;
 541                         goto fail;
 542                 }
 543
 544                 if (nxt != IPPROTO_DONE) {
 545                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
 546                             ipsec4_in_reject(m, NULL)) {
 547                                 ipsecstat.in_polvio++;
 548                                 goto fail;
 549                         }
 550                         (*inetsw[ip_protox[nxt]].pr_input)(m, off, nxt);
 551                 } else
 552                         m_freem(m);
 553                 m = NULL;
 554         }
 555
 556         if (sav) {
 557                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 558                         printf("DP ah4_input call free SA:%p\n", sav));
 559                 key_freesav(sav);
 560         }
 561         ipsecstat.in_success++;
 562         return;
 563
 564 fail:
 565         if (sav) {
 566                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 567                         printf("DP ah4_input call free SA:%p\n", sav));
 568                 key_freesav(sav);
 569         }
 570         if (m)
 571                 m_freem(m);
 572         return;
 573 }
 574 #endif /* INET */
 575
 576 #ifdef INET6
 577 int
 578 ah6_input(mp, offp, proto)
 579         struct mbuf **mp;
 580         int *offp, proto;
 581 {
 582         struct mbuf *m = *mp;
 583         int off = *offp;
 584         struct ip6_hdr *ip6;
 585         struct ah *ah;
 586         u_int32_t spi;
 587         const struct ah_algorithm *algo;
 588         size_t siz;
 589         size_t siz1;
 590         u_char *cksum;
 591         struct secasvar *sav = NULL;
 592         u_int16_t nxt;
 593         int s;
 594         size_t stripsiz = 0;
 595
 596 #ifndef PULLDOWN_TEST
 597         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah), IPPROTO_DONE);
 598         ah = (struct ah *)(mtod(m, caddr_t) + off);
 599 #else
 600         IP6_EXTHDR_GET(ah, struct ah *, m, off, sizeof(struct newah));
 601         if (ah == NULL) {
 602                 ipseclog((LOG_DEBUG, "IPv6 AH input: can't pullup\n"));
 603                 ipsec6stat.in_inval++;
 604                 return IPPROTO_DONE;
 605         }
 606 #endif
 607         ip6 = mtod(m, struct ip6_hdr *);
 608         nxt = ah->ah_nxt;
 609
 610         /* find the sassoc. */
 611         spi = ah->ah_spi;
 612
 613         if (ntohs(ip6->ip6_plen) == 0) {
 614                 ipseclog((LOG_ERR, "IPv6 AH input: "
 615                     "AH with IPv6 jumbogram is not supported.\n"));
 616                 ipsec6stat.in_inval++;
 617                 goto fail;
 618         }
 619
 620         if ((sav = key_allocsa(AF_INET6,
 621                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
 622                               IPPROTO_AH, spi)) == 0) {
 623                 ipseclog((LOG_WARNING,
 624                     "IPv6 AH input: no key association found for spi %u\n",
 625                     (u_int32_t)ntohl(spi)));
 626                 ipsec6stat.in_nosa++;
 627                 goto fail;
 628         }
 629         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 630                 printf("DP ah6_input called to allocate SA:%p\n", sav));
 631         if (sav->state != SADB_SASTATE_MATURE
 632          && sav->state != SADB_SASTATE_DYING) {
 633                 ipseclog((LOG_DEBUG,
 634                     "IPv6 AH input: non-mature/dying SA found for spi %u; ",
 635                     (u_int32_t)ntohl(spi)));
 636                 ipsec6stat.in_badspi++;
 637                 goto fail;
 638         }
 639
 640         algo = ah_algorithm_lookup(sav->alg_auth);
 641         if (!algo) {
 642                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 643                     "unsupported authentication algorithm for spi %u\n",
 644                     (u_int32_t)ntohl(spi)));
 645                 ipsec6stat.in_badspi++;
 646                 goto fail;
 647         }
 648
 649         siz = (*algo->sumsiz)(sav);
 650         siz1 = ((siz + 3) & ~(4 - 1));
 651
 652         /*
 653          * sanity checks for header, 1.
 654          */
 655     {
 656         int sizoff;
 657
 658         sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 659
 660         /*
 661          * Here, we do not do "siz1 == siz".  See ah4_input() for complete
 662          * description.
 663          */
 664         if (siz1 < siz) {
 665                 ipseclog((LOG_NOTICE, "sum length too short in IPv6 AH input "
 666                     "(%lu, should be at least %lu): %s\n",
 667                     (u_long)siz1, (u_long)siz,
 668                     ipsec6_logpacketstr(ip6, spi)));
 669                 ipsec6stat.in_inval++;
 670                 goto fail;
 671         }
 672         if ((ah->ah_len << 2) - sizoff != siz1) {
 673                 ipseclog((LOG_NOTICE, "sum length mismatch in IPv6 AH input "
 674                     "(%d should be %lu): %s\n",
 675                     (ah->ah_len << 2) - sizoff, (u_long)siz1,
 676                     ipsec6_logpacketstr(ip6, spi)));
 677                 ipsec6stat.in_inval++;
 678                 goto fail;
 679         }
 680 #ifndef PULLDOWN_TEST
 681         IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1, IPPROTO_DONE);
 682 #else
 683         IP6_EXTHDR_GET(ah, struct ah *, m, off,
 684                 sizeof(struct ah) + sizoff + siz1);
 685         if (ah == NULL) {
 686                 ipseclog((LOG_NOTICE, "couldn't pullup gather IPv6 AH checksum part"));
 687                 ipsec6stat.in_inval++;
 688                 m = NULL;
 689                 goto fail;
 690         }
 691 #endif
 692     }
 693
 694         /*
 695          * check for sequence number.
 696          */
 697         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 698                 if (ipsec_chkreplay(ntohl(((struct newah *)ah)->ah_seq), sav))
 699                         ; /* okey */
 700                 else {
 701                         ipsec6stat.in_ahreplay++;
 702                         ipseclog((LOG_WARNING,
 703                             "replay packet in IPv6 AH input: %s %s\n",
 704                             ipsec6_logpacketstr(ip6, spi),
 705                             ipsec_logsastr(sav)));
 706                         goto fail;
 707                 }
 708         }
 709
 710         /*
 711          * alright, it seems sane.  now we are going to check the
 712          * cryptographic checksum.
 713          */
 714         cksum = malloc(siz1, M_TEMP, M_NOWAIT);
 715         if (!cksum) {
 716                 ipseclog((LOG_DEBUG, "IPv6 AH input: "
 717                     "couldn't alloc temporary region for cksum\n"));
 718                 ipsec6stat.in_inval++;
 719                 goto fail;
 720         }
 721
 722         if (ah6_calccksum(m, (caddr_t)cksum, siz1, algo, sav)) {
 723                 free(cksum, M_TEMP);
 724                 ipsec6stat.in_inval++;
 725                 goto fail;
 726         }
 727         ipsec6stat.in_ahhist[sav->alg_auth]++;
 728
 729     {
 730         caddr_t sumpos = NULL;
 731
 732         if (sav->flags & SADB_X_EXT_OLD) {
 733                 /* RFC 1826 */
 734                 sumpos = (caddr_t)(ah + 1);
 735         } else {
 736                 /* RFC 2402 */
 737                 sumpos = (caddr_t)(((struct newah *)ah) + 1);
 738         }
 739
 740         if (bcmp(sumpos, cksum, siz) != 0) {
 741                 ipseclog((LOG_WARNING,
 742                     "checksum mismatch in IPv6 AH input: %s %s\n",
 743                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 744                 free(cksum, M_TEMP);
 745                 ipsec6stat.in_ahauthfail++;
 746                 goto fail;
 747         }
 748     }
 749
 750         free(cksum, M_TEMP);
 751
 752         m->m_flags |= M_AUTHIPHDR;
 753         m->m_flags |= M_AUTHIPDGM;
 754
 755 #if 0
 756         /*
 757          * looks okey, but we need more sanity check.
 758          * XXX should elaborate.
 759          */
 760         if (ah->ah_nxt == IPPROTO_IPV6) {
 761                 struct ip6_hdr *nip6;
 762                 size_t sizoff;
 763
 764                 sizoff = (sav->flags & SADB_X_EXT_OLD) ? 0 : 4;
 765
 766                 IP6_EXTHDR_CHECK(m, off, sizeof(struct ah) + sizoff + siz1
 767                                 + sizeof(struct ip6_hdr), IPPROTO_DONE);
 768
 769                 nip6 = (struct ip6_hdr *)((u_char *)(ah + 1) + sizoff + siz1);
 770                 if (!IN6_ARE_ADDR_EQUAL(&nip6->ip6_src, &ip6->ip6_src)
 771                  || !IN6_ARE_ADDR_EQUAL(&nip6->ip6_dst, &ip6->ip6_dst)) {
 772                         m->m_flags &= ~M_AUTHIPHDR;
 773                         m->m_flags &= ~M_AUTHIPDGM;
 774                 }
 775         } else if (ah->ah_nxt == IPPROTO_IPIP) {
 776                 m->m_flags &= ~M_AUTHIPHDR;
 777                 m->m_flags &= ~M_AUTHIPDGM;
 778         } else if (ah->ah_nxt == IPPROTO_IP) {
 779                 m->m_flags &= ~M_AUTHIPHDR;
 780                 m->m_flags &= ~M_AUTHIPDGM;
 781         }
 782 #endif
 783
 784         if (m->m_flags & M_AUTHIPHDR
 785          && m->m_flags & M_AUTHIPDGM) {
 786 #if 0
 787                 ipseclog((LOG_DEBUG,
 788                     "IPv6 AH input: authentication succeess\n"));
 789 #endif
 790                 ipsec6stat.in_ahauthsucc++;
 791         } else {
 792                 ipseclog((LOG_WARNING,
 793                     "authentication failed in IPv6 AH input: %s %s\n",
 794                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
 795                 ipsec6stat.in_ahauthfail++;
 796                 goto fail;
 797         }
 798
 799         /*
 800          * update sequence number.
 801          */
 802         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
 803                 if (ipsec_updatereplay(ntohl(((struct newah *)ah)->ah_seq), sav)) {
 804                         ipsec6stat.in_ahreplay++;
 805                         goto fail;
 806                 }
 807         }
 808
 809         /* was it transmitted over the IPsec tunnel SA? */
 810         if (sav->flags & SADB_X_EXT_OLD) {
 811                 /* RFC 1826 */
 812                 stripsiz = sizeof(struct ah) + siz1;
 813         } else {
 814                 /* RFC 2402 */
 815                 stripsiz = sizeof(struct newah) + siz1;
 816         }
 817         if (ipsec6_tunnel_validate(m, off + stripsiz, nxt, sav)) {
 818                 /*
 819                  * strip off all the headers that precedes AH.
 820                  *      IP6 xx AH IP6' payload -> IP6' payload
 821                  *
 822                  * XXX more sanity checks
 823                  * XXX relationship with gif?
 824                  */
 825                 u_int32_t flowinfo;     /* net endian */
 826
 827                 flowinfo = ip6->ip6_flow;
 828                 m_adj(m, off + stripsiz);
 829                 if (m->m_len < sizeof(*ip6)) {
 830                         /*
 831                          * m_pullup is prohibited in KAME IPv6 input processing
 832                          * but there's no other way!
 833                          */
 834                         m = m_pullup(m, sizeof(*ip6));
 835                         if (!m) {
 836                                 ipsec6stat.in_inval++;
 837                                 goto fail;
 838                         }
 839                 }
 840                 ip6 = mtod(m, struct ip6_hdr *);
 841                 /* ECN consideration. */
 842                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
 843                 if (!key_checktunnelsanity(sav, AF_INET6,
 844                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
 845                         ipseclog((LOG_NOTICE, "ipsec tunnel address mismatch "
 846                             "in IPv6 AH input: %s %s\n",
 847                             ipsec6_logpacketstr(ip6, spi),
 848                             ipsec_logsastr(sav)));
 849                         ipsec6stat.in_inval++;
 850                         goto fail;
 851                 }
 852
 853 #if 1
 854                 /*
 855                  * should the inner packet be considered authentic?
 856                  * see comment in ah4_input().
 857                  */
 858                 m->m_flags &= ~M_AUTHIPHDR;
 859                 m->m_flags &= ~M_AUTHIPDGM;
 860 #endif
 861
 862                 key_sa_recordxfer(sav, m);
 863                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0 ||
 864                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
 865                         ipsec6stat.in_nomem++;
 866                         goto fail;
 867                 }
 868
 869                 s = splimp();
 870                 if (IF_QFULL(&ip6intrq)) {
 871                         ipsec6stat.in_inval++;
 872                         splx(s);
 873                         goto fail;
 874                 }
 875                 IF_ENQUEUE(&ip6intrq, m);
 876                 m = NULL;
 877                 schednetisr(NETISR_IPV6); /* can be skipped but to make sure */
 878                 splx(s);
 879                 nxt = IPPROTO_DONE;
 880         } else {
 881                 /*
 882                  * strip off AH.
 883                  */
 884                 char *prvnxtp;
 885
 886                 /*
 887                  * Copy the value of the next header field of AH to the
 888                  * next header field of the previous header.
 889                  * This is necessary because AH will be stripped off below.
 890                  */
 891                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
 892                 *prvnxtp = nxt;
 893
 894                 ip6 = mtod(m, struct ip6_hdr *);
 895 #ifndef PULLDOWN_TEST
 896                 /*
 897                  * We do deep-copy since KAME requires that
 898                  * the packet is placed in a single mbuf.
 899                  */
 900                 ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 901                 m->m_data += stripsiz;
 902                 m->m_len -= stripsiz;
 903                 m->m_pkthdr.len -= stripsiz;
 904 #else
 905                 /*
 906                  * even in m_pulldown case, we need to strip off AH so that
 907                  * we can compute checksum for multiple AH correctly.
 908                  */
 909                 if (m->m_len >= stripsiz + off) {
 910                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
 911                         m->m_data += stripsiz;
 912                         m->m_len -= stripsiz;
 913                         m->m_pkthdr.len -= stripsiz;
 914                 } else {
 915                         /*
 916                          * this comes with no copy if the boundary is on
 917                          * cluster
 918                          */
 919                         struct mbuf *n;
 920
 921                         n = m_split(m, off, M_DONTWAIT);
 922                         if (n == NULL) {
 923                                 /* m is retained by m_split */
 924                                 goto fail;
 925                         }
 926                         m_adj(n, stripsiz);
 927                         m_cat(m, n);
 928                         /* m_cat does not update m_pkthdr.len */
 929                         m->m_pkthdr.len += n->m_pkthdr.len;
 930                 }
 931 #endif
 932                 ip6 = mtod(m, struct ip6_hdr *);
 933                 /* XXX jumbogram */
 934                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
 935
 936                 key_sa_recordxfer(sav, m);
 937                 if (ipsec_addhist(m, IPPROTO_AH, spi) != 0) {
 938                         ipsec6stat.in_nomem++;
 939                         goto fail;
 940                 }
 941         }
 942
 943         *offp = off;
 944         *mp = m;
 945
 946         if (sav) {
 947                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 948                         printf("DP ah6_input call free SA:%p\n", sav));
 949                 key_freesav(sav);
 950         }
 951         ipsec6stat.in_success++;
 952         return nxt;
 953
 954 fail:
 955         if (sav) {
 956                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
 957                         printf("DP ah6_input call free SA:%p\n", sav));
 958                 key_freesav(sav);
 959         }
 960         if (m)
 961                 m_freem(m);
 962         return IPPROTO_DONE;
 963 }
 964
 965 void
 966 ah6_ctlinput(cmd, sa, d)
 967         int cmd;
 968         struct sockaddr *sa;
 969         void *d;
 970 {
 971         const struct newah *ahp;
 972         struct newah ah;
 973         struct secasvar *sav;
 974         struct ip6_hdr *ip6;
 975         struct mbuf *m;
 976         struct ip6ctlparam *ip6cp = NULL;
 977         int off;
 978         struct sockaddr_in6 *sa6_src, *sa6_dst;
 979
 980         if (sa->sa_family != AF_INET6 ||
 981             sa->sa_len != sizeof(struct sockaddr_in6))
 982                 return;
 983         if ((unsigned)cmd >= PRC_NCMDS)
 984                 return;
 985
 986         /* if the parameter is from icmp6, decode it. */
 987         if (d != NULL) {
 988                 ip6cp = (struct ip6ctlparam *)d;
 989                 m = ip6cp->ip6c_m;
 990                 ip6 = ip6cp->ip6c_ip6;
 991                 off = ip6cp->ip6c_off;
 992         } else {
 993                 m = NULL;
 994                 ip6 = NULL;
 995         }
 996
 997         if (ip6) {
 998                 /*
 999                  * XXX: We assume that when ip6 is non NULL,
1000                  * M and OFF are valid.
1001                  */
1002
1003                 /* check if we can safely examine src and dst ports */
1004                 if (m->m_pkthdr.len < off + sizeof(ah))
1005                         return;
1006
1007                 if (m->m_len < off + sizeof(ah)) {
1008                         /*
1009                          * this should be rare case,
1010                          * so we compromise on this copy...
1011                          */
1012                         m_copydata(m, off, sizeof(ah), (caddr_t)&ah);
1013                         ahp = &ah;
1014                 } else
1015                         ahp = (struct newah *)(mtod(m, caddr_t) + off);
1016
1017                 if (cmd == PRC_MSGSIZE) {
1018                         int valid = 0;
1019
1020                         /*
1021                          * Check to see if we have a valid SA corresponding to
1022                          * the address in the ICMP message payload.
1023                          */
1024                         sa6_src = ip6cp->ip6c_src;
1025                         sa6_dst = (struct sockaddr_in6 *)sa;
1026                         sav = key_allocsa(AF_INET6,
1027                                           (caddr_t)&sa6_src->sin6_addr,
1028                                           (caddr_t)&sa6_dst->sin6_addr,
1029                                           IPPROTO_AH, ahp->ah_spi);
1030                         if (sav) {
1031                                 if (sav->state == SADB_SASTATE_MATURE ||
1032                                     sav->state == SADB_SASTATE_DYING)
1033                                         valid++;
1034                                 key_freesav(sav);
1035                         }
1036
1037                         /* XXX Further validation? */
1038
1039                         /*
1040                          * Depending on the value of "valid" and routing table
1041                          * size (mtudisc_{hi,lo}wat), we will:
1042                          * - recalcurate the new MTU and create the
1043                          *   corresponding routing entry, or
1044                          * - ignore the MTU change notification.
1045                          */
1046                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
1047                 }
1048
1049                 /* we normally notify single pcb here */
1050         } else {
1051                 /* we normally notify any pcb here */
1052         }
1053 }
1054 #endif /* INET6 */