The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netipsec/xform_ah.c

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    1 /*      $NetBSD: xform_ah.c,v 1.21 2008/04/23 06:09:05 thorpej Exp $    */
    2 /*      $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $   */
    3 /*      $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
    4 /*
    5  * The authors of this code are John Ioannidis (ji@tla.org),
    6  * Angelos D. Keromytis (kermit@csd.uch.gr) and
    7  * Niels Provos (provos@physnet.uni-hamburg.de).
    8  *
    9  * The original version of this code was written by John Ioannidis
   10  * for BSD/OS in Athens, Greece, in November 1995.
   11  *
   12  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
   13  * by Angelos D. Keromytis.
   14  *
   15  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
   16  * and Niels Provos.
   17  *
   18  * Additional features in 1999 by Angelos D. Keromytis and Niklas Hallqvist.
   19  *
   20  * Copyright (c) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
   21  * Angelos D. Keromytis and Niels Provos.
   22  * Copyright (c) 1999 Niklas Hallqvist.
   23  * Copyright (c) 2001 Angelos D. Keromytis.
   24  *
   25  * Permission to use, copy, and modify this software with or without fee
   26  * is hereby granted, provided that this entire notice is included in
   27  * all copies of any software which is or includes a copy or
   28  * modification of this software.
   29  * You may use this code under the GNU public license if you so wish. Please
   30  * contribute changes back to the authors under this freer than GPL license
   31  * so that we may further the use of strong encryption without limitations to
   32  * all.
   33  *
   34  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
   35  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
   36  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
   37  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
   38  * PURPOSE.
   39  */
   40 
   41 #include <sys/cdefs.h>
   42 __KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.21 2008/04/23 06:09:05 thorpej Exp $");
   43 
   44 #include "opt_inet.h"
   45 #ifdef __FreeBSD__
   46 #include "opt_inet6.h"
   47 #endif
   48 
   49 #include <sys/param.h>
   50 #include <sys/systm.h>
   51 #include <sys/mbuf.h>
   52 #include <sys/socket.h>
   53 #include <sys/syslog.h>
   54 #include <sys/kernel.h>
   55 #include <sys/sysctl.h>
   56 
   57 #include <net/if.h>
   58 
   59 #include <netinet/in.h>
   60 #include <netinet/in_systm.h>
   61 #include <netinet/ip.h>
   62 #include <netinet/ip_ecn.h>
   63 #include <netinet/ip6.h>
   64 
   65 #include <net/route.h>
   66 #include <netipsec/ipsec.h>
   67 #include <netipsec/ipsec_private.h>
   68 #include <netipsec/ah.h>
   69 #include <netipsec/ah_var.h>
   70 #include <netipsec/xform.h>
   71 
   72 #ifdef INET6
   73 #include <netinet6/ip6_var.h>
   74 #include <netipsec/ipsec6.h>
   75 #  ifdef __FreeBSD__
   76 #  include <netinet6/ip6_ecn.h>
   77 #  endif
   78 #endif
   79 
   80 #include <netipsec/key.h>
   81 #include <netipsec/key_debug.h>
   82 #include <netipsec/ipsec_osdep.h>
   83 
   84 #include <opencrypto/cryptodev.h>
   85 
   86 /*
   87  * Return header size in bytes.  The old protocol did not support
   88  * the replay counter; the new protocol always includes the counter.
   89  */
   90 #define HDRSIZE(sav) \
   91         (((sav)->flags & SADB_X_EXT_OLD) ? \
   92                 sizeof (struct ah) : sizeof (struct ah) + sizeof (u_int32_t))
   93 /*
   94  * Return authenticator size in bytes.  The old protocol is known
   95  * to use a fixed 16-byte authenticator.  The new algorithm gets
   96  * this size from the xform but is (currently) always 12.
   97  */
   98 #define AUTHSIZE(sav) \
   99         ((sav->flags & SADB_X_EXT_OLD) ? 16 : (sav)->tdb_authalgxform->authsize)
  100 
  101 percpu_t *ahstat_percpu;
  102 
  103 int     ah_enable = 1;                  /* control flow of packets with AH */
  104 int     ip4_ah_cleartos = 1;            /* clear ip_tos when doing AH calc */
  105 
  106 #ifdef __FreeBSD__
  107 SYSCTL_DECL(_net_inet_ah);
  108 SYSCTL_INT(_net_inet_ah, OID_AUTO,
  109         ah_enable,      CTLFLAG_RW,     &ah_enable,     0, "");
  110 SYSCTL_INT(_net_inet_ah, OID_AUTO,
  111         ah_cleartos,    CTLFLAG_RW,     &ip4_ah_cleartos,       0, "");
  112 SYSCTL_STRUCT(_net_inet_ah, IPSECCTL_STATS,
  113         stats,          CTLFLAG_RD,     &ahstat,        ahstat, "");
  114 
  115 #endif /* __FreeBSD__ */
  116 
  117 static unsigned char ipseczeroes[256];  /* larger than an ip6 extension hdr */
  118 
  119 static int ah_input_cb(struct cryptop*);
  120 static int ah_output_cb(struct cryptop*);
  121 
  122 /*
  123  * NB: this is public for use by the PF_KEY support.
  124  */
  125 struct auth_hash *
  126 ah_algorithm_lookup(int alg)
  127 {
  128         if (alg >= AH_ALG_MAX)
  129                 return NULL;
  130         switch (alg) {
  131         case SADB_X_AALG_NULL:
  132                 return &auth_hash_null;
  133         case SADB_AALG_MD5HMAC:
  134                 return &auth_hash_hmac_md5_96;
  135         case SADB_AALG_SHA1HMAC:
  136                 return &auth_hash_hmac_sha1_96;
  137         case SADB_X_AALG_RIPEMD160HMAC:
  138                 return &auth_hash_hmac_ripemd_160_96;
  139         case SADB_X_AALG_MD5:
  140                 return &auth_hash_key_md5;
  141         case SADB_X_AALG_SHA:
  142                 return &auth_hash_key_sha1;
  143         case SADB_X_AALG_SHA2_256:
  144                 return &auth_hash_hmac_sha2_256;
  145         case SADB_X_AALG_SHA2_384:
  146                 return &auth_hash_hmac_sha2_384;
  147         case SADB_X_AALG_SHA2_512:
  148                 return &auth_hash_hmac_sha2_512;
  149         }
  150         return NULL;
  151 }
  152 
  153 size_t
  154 ah_hdrsiz(struct secasvar *sav)
  155 {
  156         size_t size;
  157 
  158         if (sav != NULL) {
  159                 int authsize;
  160                 IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
  161                         ("ah_hdrsiz: null xform"));
  162                 /*XXX not right for null algorithm--does it matter??*/
  163                 authsize = AUTHSIZE(sav);
  164                 size = roundup(authsize, sizeof (u_int32_t)) + HDRSIZE(sav);
  165         } else {
  166                 /* default guess */
  167                 size = sizeof (struct ah) + sizeof (u_int32_t) + 16;
  168         }
  169         return size;
  170 }
  171 
  172 /*
  173  * NB: public for use by esp_init.
  174  */
  175 int
  176 ah_init0(struct secasvar *sav, struct xformsw *xsp, struct cryptoini *cria)
  177 {
  178         struct auth_hash *thash;
  179         int keylen;
  180 
  181         thash = ah_algorithm_lookup(sav->alg_auth);
  182         if (thash == NULL) {
  183                 DPRINTF(("ah_init: unsupported authentication algorithm %u\n",
  184                         sav->alg_auth));
  185                 return EINVAL;
  186         }
  187         /*
  188          * Verify the replay state block allocation is consistent with
  189          * the protocol type.  We check here so we can make assumptions
  190          * later during protocol processing.
  191          */
  192         /* NB: replay state is setup elsewhere (sigh) */
  193         if (((sav->flags&SADB_X_EXT_OLD) == 0) ^ (sav->replay != NULL)) {
  194                 DPRINTF(("ah_init: replay state block inconsistency, "
  195                         "%s algorithm %s replay state\n",
  196                         (sav->flags & SADB_X_EXT_OLD) ? "old" : "new",
  197                         sav->replay == NULL ? "without" : "with"));
  198                 return EINVAL;
  199         }
  200         if (sav->key_auth == NULL) {
  201                 DPRINTF(("ah_init: no authentication key for %s "
  202                         "algorithm\n", thash->name));
  203                 return EINVAL;
  204         }
  205         keylen = _KEYLEN(sav->key_auth);
  206         if (keylen != thash->keysize && thash->keysize != 0) {
  207                 DPRINTF(("ah_init: invalid keylength %d, algorithm "
  208                          "%s requires keysize %d\n",
  209                          keylen, thash->name, thash->keysize));
  210                 return EINVAL;
  211         }
  212 
  213         sav->tdb_xform = xsp;
  214         sav->tdb_authalgxform = thash;
  215 
  216         /* Initialize crypto session. */
  217         bzero(cria, sizeof (*cria));
  218         cria->cri_alg = sav->tdb_authalgxform->type;
  219         cria->cri_klen = _KEYBITS(sav->key_auth);
  220         cria->cri_key = _KEYBUF(sav->key_auth);
  221 
  222         return 0;
  223 }
  224 
  225 /*
  226  * ah_init() is called when an SPI is being set up.
  227  */
  228 static int
  229 ah_init(struct secasvar *sav, struct xformsw *xsp)
  230 {
  231         struct cryptoini cria;
  232         int error;
  233 
  234         error = ah_init0(sav, xsp, &cria);
  235         if (!error) {
  236                 mutex_spin_enter(&crypto_mtx);
  237                 error = crypto_newsession(&sav->tdb_cryptoid,
  238                                            &cria, crypto_support);
  239                 mutex_spin_exit(&crypto_mtx);
  240         }
  241         return error;
  242 }
  243 
  244 /*
  245  * Paranoia.
  246  *
  247  * NB: public for use by esp_zeroize (XXX).
  248  */
  249 int
  250 ah_zeroize(struct secasvar *sav)
  251 {
  252         int err;
  253 
  254         if (sav->key_auth)
  255                 bzero(_KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth));
  256 
  257         mutex_spin_enter(&crypto_mtx);
  258         err = crypto_freesession(sav->tdb_cryptoid);
  259         mutex_spin_exit(&crypto_mtx);
  260         sav->tdb_cryptoid = 0;
  261         sav->tdb_authalgxform = NULL;
  262         sav->tdb_xform = NULL;
  263         return err;
  264 }
  265 
  266 /*
  267  * Massage IPv4/IPv6 headers for AH processing.
  268  */
  269 static int
  270 ah_massage_headers(struct mbuf **m0, int proto, int skip, int alg, int out)
  271 {
  272         struct mbuf *m = *m0;
  273         unsigned char *ptr;
  274         int off, count;
  275 
  276 #ifdef INET
  277         struct ip *ip;
  278 #endif /* INET */
  279 
  280 #ifdef INET6
  281         struct ip6_ext *ip6e;
  282         struct ip6_hdr ip6;
  283         int alloc, len, ad;
  284 #endif /* INET6 */
  285 
  286         switch (proto) {
  287 #ifdef INET
  288         case AF_INET:
  289                 /*
  290                  * This is the least painful way of dealing with IPv4 header
  291                  * and option processing -- just make sure they're in
  292                  * contiguous memory.
  293                  */
  294                 *m0 = m = m_pullup(m, skip);
  295                 if (m == NULL) {
  296                         DPRINTF(("ah_massage_headers: m_pullup failed\n"));
  297                         return ENOBUFS;
  298                 }
  299 
  300                 /* Fix the IP header */
  301                 ip = mtod(m, struct ip *);
  302                 if (ip4_ah_cleartos)
  303                         ip->ip_tos = 0;
  304                 ip->ip_ttl = 0;
  305                 ip->ip_sum = 0;
  306                 ip->ip_off = htons(ntohs(ip->ip_off) & ip4_ah_offsetmask);
  307 
  308                 /*
  309                  * On FreeBSD, ip_off and ip_len assumed in host endian;
  310                  * they are converted (if necessary) by ip_input().
  311                  * On NetBSD, ip_off and ip_len are in network byte order.
  312                  * They must be massaged back to network byte order
  313                  * before verifying the  HMAC. Moreover, on FreeBSD,
  314                  * we should add `skip' back into the massaged ip_len
  315                  * (presumably ip_input() deducted it before we got here?)
  316                  * whereas on NetBSD, we should not.
  317                  */
  318 #ifdef __FreeBSD__
  319   #define TOHOST(x) (x)
  320 #else
  321   #define TOHOST(x) (ntohs(x))
  322 #endif
  323                 if (!out) {
  324                         u_int16_t inlen = TOHOST(ip->ip_len);
  325 
  326 #ifdef __FreeBSD__
  327                         ip->ip_len = htons(inlen + skip);
  328 #else  /*!__FreeBSD__ */
  329                         ip->ip_len = htons(inlen);
  330 #endif /*!__FreeBSD__ */
  331                         DPRINTF(("ip len: skip %d, "
  332                                  "in %d host %d: new: raw %d host %d\n",
  333                                  skip,
  334                                  inlen, TOHOST(inlen),
  335                                  ip->ip_len, ntohs(ip->ip_len)));
  336 
  337 
  338                         if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
  339                                 ip->ip_off  &= IP_OFF_CONVERT(IP_DF);
  340                         else
  341                                 ip->ip_off = 0;
  342                 } else {
  343                         if (alg == CRYPTO_MD5_KPDK || alg == CRYPTO_SHA1_KPDK)
  344                                 ip->ip_off &= IP_OFF_CONVERT(IP_DF);
  345                         else
  346                                 ip->ip_off = 0;
  347                 }
  348 
  349                 ptr = mtod(m, unsigned char *) + sizeof(struct ip);
  350 
  351                 /* IPv4 option processing */
  352                 for (off = sizeof(struct ip); off < skip;) {
  353                         if (ptr[off] == IPOPT_EOL || ptr[off] == IPOPT_NOP ||
  354                             off + 1 < skip)
  355                                 ;
  356                         else {
  357                                 DPRINTF(("ah_massage_headers: illegal IPv4 "
  358                                     "option length for option %d\n",
  359                                     ptr[off]));
  360 
  361                                 m_freem(m);
  362                                 return EINVAL;
  363                         }
  364 
  365                         switch (ptr[off]) {
  366                         case IPOPT_EOL:
  367                                 off = skip;  /* End the loop. */
  368                                 break;
  369 
  370                         case IPOPT_NOP:
  371                                 off++;
  372                                 break;
  373 
  374                         case IPOPT_SECURITY:    /* 0x82 */
  375                         case 0x85:      /* Extended security. */
  376                         case 0x86:      /* Commercial security. */
  377                         case 0x94:      /* Router alert */
  378                         case 0x95:      /* RFC1770 */
  379                                 /* Sanity check for option length. */
  380                                 if (ptr[off + 1] < 2) {
  381                                         DPRINTF(("ah_massage_headers: "
  382                                             "illegal IPv4 option length for "
  383                                             "option %d\n", ptr[off]));
  384 
  385                                         m_freem(m);
  386                                         return EINVAL;
  387                                 }
  388 
  389                                 off += ptr[off + 1];
  390                                 break;
  391 
  392                         case IPOPT_LSRR:
  393                         case IPOPT_SSRR:
  394                                 /* Sanity check for option length. */
  395                                 if (ptr[off + 1] < 2) {
  396                                         DPRINTF(("ah_massage_headers: "
  397                                             "illegal IPv4 option length for "
  398                                             "option %d\n", ptr[off]));
  399 
  400                                         m_freem(m);
  401                                         return EINVAL;
  402                                 }
  403 
  404                                 /*
  405                                  * On output, if we have either of the
  406                                  * source routing options, we should
  407                                  * swap the destination address of the
  408                                  * IP header with the last address
  409                                  * specified in the option, as that is
  410                                  * what the destination's IP header
  411                                  * will look like.
  412                                  */
  413                                 if (out)
  414                                         bcopy(ptr + off + ptr[off + 1] -
  415                                             sizeof(struct in_addr),
  416                                             &(ip->ip_dst), sizeof(struct in_addr));
  417 
  418                                 /* Fall through */
  419                         default:
  420                                 /* Sanity check for option length. */
  421                                 if (ptr[off + 1] < 2) {
  422                                         DPRINTF(("ah_massage_headers: "
  423                                             "illegal IPv4 option length for "
  424                                             "option %d\n", ptr[off]));
  425                                         m_freem(m);
  426                                         return EINVAL;
  427                                 }
  428 
  429                                 /* Zeroize all other options. */
  430                                 count = ptr[off + 1];
  431                                 bcopy(ipseczeroes, ptr, count);
  432                                 off += count;
  433                                 break;
  434                         }
  435 
  436                         /* Sanity check. */
  437                         if (off > skip) {
  438                                 DPRINTF(("ah_massage_headers(): malformed "
  439                                     "IPv4 options header\n"));
  440 
  441                                 m_freem(m);
  442                                 return EINVAL;
  443                         }
  444                 }
  445 
  446                 break;
  447 #endif /* INET */
  448 
  449 #ifdef INET6
  450         case AF_INET6:  /* Ugly... */
  451                 /* Copy and "cook" the IPv6 header. */
  452                 m_copydata(m, 0, sizeof(ip6), &ip6);
  453 
  454                 /* We don't do IPv6 Jumbograms. */
  455                 if (ip6.ip6_plen == 0) {
  456                         DPRINTF(("ah_massage_headers: unsupported IPv6 jumbogram\n"));
  457                         m_freem(m);
  458                         return EMSGSIZE;
  459                 }
  460 
  461                 ip6.ip6_flow = 0;
  462                 ip6.ip6_hlim = 0;
  463                 ip6.ip6_vfc &= ~IPV6_VERSION_MASK;
  464                 ip6.ip6_vfc |= IPV6_VERSION;
  465 
  466                 /* Scoped address handling. */
  467                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_src))
  468                         ip6.ip6_src.s6_addr16[1] = 0;
  469                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6.ip6_dst))
  470                         ip6.ip6_dst.s6_addr16[1] = 0;
  471 
  472                 /* Done with IPv6 header. */
  473                 m_copyback(m, 0, sizeof(struct ip6_hdr), &ip6);
  474 
  475                 /* Let's deal with the remaining headers (if any). */
  476                 if (skip - sizeof(struct ip6_hdr) > 0) {
  477                         if (m->m_len <= skip) {
  478                                 ptr = (unsigned char *) malloc(
  479                                     skip - sizeof(struct ip6_hdr),
  480                                     M_XDATA, M_NOWAIT);
  481                                 if (ptr == NULL) {
  482                                         DPRINTF(("ah_massage_headers: failed "
  483                                             "to allocate memory for IPv6 "
  484                                             "headers\n"));
  485                                         m_freem(m);
  486                                         return ENOBUFS;
  487                                 }
  488 
  489                                 /*
  490                                  * Copy all the protocol headers after
  491                                  * the IPv6 header.
  492                                  */
  493                                 m_copydata(m, sizeof(struct ip6_hdr),
  494                                     skip - sizeof(struct ip6_hdr), ptr);
  495                                 alloc = 1;
  496                         } else {
  497                                 /* No need to allocate memory. */
  498                                 ptr = mtod(m, unsigned char *) +
  499                                     sizeof(struct ip6_hdr);
  500                                 alloc = 0;
  501                         }
  502                 } else
  503                         break;
  504 
  505                 off = ip6.ip6_nxt & 0xff; /* Next header type. */
  506 
  507                 for (len = 0; len < skip - sizeof(struct ip6_hdr);)
  508                         switch (off) {
  509                         case IPPROTO_HOPOPTS:
  510                         case IPPROTO_DSTOPTS:
  511                                 ip6e = (struct ip6_ext *) (ptr + len);
  512 
  513                                 /*
  514                                  * Process the mutable/immutable
  515                                  * options -- borrows heavily from the
  516                                  * KAME code.
  517                                  */
  518                                 for (count = len + sizeof(struct ip6_ext);
  519                                      count < len + ((ip6e->ip6e_len + 1) << 3);) {
  520                                         if (ptr[count] == IP6OPT_PAD1) {
  521                                                 count++;
  522                                                 continue; /* Skip padding. */
  523                                         }
  524 
  525                                         /* Sanity check. */
  526                                         if (count > len +
  527                                             ((ip6e->ip6e_len + 1) << 3)) {
  528                                                 m_freem(m);
  529 
  530                                                 /* Free, if we allocated. */
  531                                                 if (alloc)
  532                                                         FREE(ptr, M_XDATA);
  533                                                 return EINVAL;
  534                                         }
  535 
  536                                         ad = ptr[count + 1];
  537 
  538                                         /* If mutable option, zeroize. */
  539                                         if (ptr[count] & IP6OPT_MUTABLE)
  540                                                 bcopy(ipseczeroes, ptr + count,
  541                                                     ptr[count + 1]);
  542 
  543                                         count += ad;
  544 
  545                                         /* Sanity check. */
  546                                         if (count >
  547                                             skip - sizeof(struct ip6_hdr)) {
  548                                                 m_freem(m);
  549 
  550                                                 /* Free, if we allocated. */
  551                                                 if (alloc)
  552                                                         FREE(ptr, M_XDATA);
  553                                                 return EINVAL;
  554                                         }
  555                                 }
  556 
  557                                 /* Advance. */
  558                                 len += ((ip6e->ip6e_len + 1) << 3);
  559                                 off = ip6e->ip6e_nxt;
  560                                 break;
  561 
  562                         case IPPROTO_ROUTING:
  563                                 /*
  564                                  * Always include routing headers in
  565                                  * computation.
  566                                  */
  567                                 ip6e = (struct ip6_ext *) (ptr + len);
  568                                 len += ((ip6e->ip6e_len + 1) << 3);
  569                                 off = ip6e->ip6e_nxt;
  570                                 break;
  571 
  572                         default:
  573                                 DPRINTF(("ah_massage_headers: unexpected "
  574                                     "IPv6 header type %d", off));
  575                                 if (alloc)
  576                                         FREE(ptr, M_XDATA);
  577                                 m_freem(m);
  578                                 return EINVAL;
  579                         }
  580 
  581                 /* Copyback and free, if we allocated. */
  582                 if (alloc) {
  583                         m_copyback(m, sizeof(struct ip6_hdr),
  584                             skip - sizeof(struct ip6_hdr), ptr);
  585                         free(ptr, M_XDATA);
  586                 }
  587 
  588                 break;
  589 #endif /* INET6 */
  590         }
  591 
  592         return 0;
  593 }
  594 
  595 /*
  596  * ah_input() gets called to verify that an input packet
  597  * passes authentication.
  598  */
  599 static int
  600 ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
  601 {
  602         struct auth_hash *ahx;
  603         struct tdb_ident *tdbi;
  604         struct tdb_crypto *tc;
  605         struct m_tag *mtag;
  606         struct newah *ah;
  607         int hl, rplen, authsize;
  608 
  609         struct cryptodesc *crda;
  610         struct cryptop *crp;
  611 
  612         IPSEC_SPLASSERT_SOFTNET("ah_input");
  613 
  614         IPSEC_ASSERT(sav != NULL, ("ah_input: null SA"));
  615         IPSEC_ASSERT(sav->key_auth != NULL,
  616                 ("ah_input: null authentication key"));
  617         IPSEC_ASSERT(sav->tdb_authalgxform != NULL,
  618                 ("ah_input: null authentication xform"));
  619 
  620         /* Figure out header size. */
  621         rplen = HDRSIZE(sav);
  622 
  623         /* XXX don't pullup, just copy header */
  624         IP6_EXTHDR_GET(ah, struct newah *, m, skip, rplen);
  625         if (ah == NULL) {
  626                 DPRINTF(("ah_input: cannot pullup header\n"));
  627                 AH_STATINC(AH_STAT_HDROPS);     /*XXX*/
  628                 m_freem(m);
  629                 return ENOBUFS;
  630         }
  631 
  632         /* Check replay window, if applicable. */
  633         if (sav->replay && !ipsec_chkreplay(ntohl(ah->ah_seq), sav)) {
  634                 AH_STATINC(AH_STAT_REPLAY);
  635                 DPRINTF(("ah_input: packet replay failure: %s\n",
  636                           ipsec_logsastr(sav)));
  637                 m_freem(m);
  638                 return ENOBUFS;
  639         }
  640 
  641         /* Verify AH header length. */
  642         hl = ah->ah_len * sizeof (u_int32_t);
  643         ahx = sav->tdb_authalgxform;
  644         authsize = AUTHSIZE(sav);
  645         if (hl != authsize + rplen - sizeof (struct ah)) {
  646                 DPRINTF(("ah_input: bad authenticator length %u (expecting %lu)"
  647                         " for packet in SA %s/%08lx\n",
  648                         hl, (u_long) (authsize + rplen - sizeof (struct ah)),
  649                         ipsec_address(&sav->sah->saidx.dst),
  650                         (u_long) ntohl(sav->spi)));
  651                 AH_STATINC(AH_STAT_BADAUTHL);
  652                 m_freem(m);
  653                 return EACCES;
  654         }
  655         AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl);
  656         DPRINTF(("ah_input skip %d poff %d\n"
  657                  "len: hl %d authsize %d rpl %d expect %ld\n",
  658                  skip, protoff,
  659                  hl, authsize, rplen,
  660                  (long)(authsize + rplen - sizeof(struct ah))));
  661 
  662         /* Get crypto descriptors. */
  663         crp = crypto_getreq(1);
  664         if (crp == NULL) {
  665                 DPRINTF(("ah_input: failed to acquire crypto descriptor\n"));
  666                 AH_STATINC(AH_STAT_CRYPTO);
  667                 m_freem(m);
  668                 return ENOBUFS;
  669         }
  670 
  671         crda = crp->crp_desc;
  672         IPSEC_ASSERT(crda != NULL, ("ah_input: null crypto descriptor"));
  673 
  674         crda->crd_skip = 0;
  675         crda->crd_len = m->m_pkthdr.len;
  676         crda->crd_inject = skip + rplen;
  677 
  678         /* Authentication operation. */
  679         crda->crd_alg = ahx->type;
  680         crda->crd_key = _KEYBUF(sav->key_auth);
  681         crda->crd_klen = _KEYBITS(sav->key_auth);
  682 
  683         /* Find out if we've already done crypto. */
  684         for (mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, NULL);
  685              mtag != NULL;
  686              mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_CRYPTO_DONE, mtag)) {
  687                 tdbi = (struct tdb_ident *) (mtag + 1);
  688                 if (tdbi->proto == sav->sah->saidx.proto &&
  689                     tdbi->spi == sav->spi &&
  690                     !bcmp(&tdbi->dst, &sav->sah->saidx.dst,
  691                           sizeof (union sockaddr_union)))
  692                         break;
  693         }
  694 
  695         /* Allocate IPsec-specific opaque crypto info. */
  696         if (mtag == NULL) {
  697                 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto) +
  698                         skip + rplen + authsize, M_XDATA, M_NOWAIT|M_ZERO);
  699         } else {
  700                 /* Hash verification has already been done successfully. */
  701                 tc = (struct tdb_crypto *) malloc(sizeof (struct tdb_crypto),
  702                                                     M_XDATA, M_NOWAIT|M_ZERO);
  703         }
  704         if (tc == NULL) {
  705                 DPRINTF(("ah_input: failed to allocate tdb_crypto\n"));
  706                 AH_STATINC(AH_STAT_CRYPTO);
  707                 crypto_freereq(crp);
  708                 m_freem(m);
  709                 return ENOBUFS;
  710         }
  711 
  712         /* Only save information if crypto processing is needed. */
  713         if (mtag == NULL) {
  714                 int error;
  715 
  716                 /*
  717                  * Save the authenticator, the skipped portion of the packet,
  718                  * and the AH header.
  719                  */
  720                 m_copydata(m, 0, skip + rplen + authsize, (char *)(tc+1));
  721 
  722                 {
  723                         u_int8_t *pppp = ((char *)(tc+1))+skip+rplen;
  724                         DPRINTF(("ah_input: zeroing %d bytes of authent " \
  725                     "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
  726                                  authsize,
  727                                  pppp[0], pppp[1], pppp[2], pppp[3],
  728                                  pppp[4], pppp[5], pppp[6], pppp[7],
  729                                  pppp[8], pppp[9], pppp[10], pppp[11]));
  730                 }
  731 
  732                 /* Zeroize the authenticator on the packet. */
  733                 m_copyback(m, skip + rplen, authsize, ipseczeroes);
  734 
  735                 /* "Massage" the packet headers for crypto processing. */
  736                 error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
  737                     skip, ahx->type, 0);
  738                 if (error != 0) {
  739                         /* NB: mbuf is free'd by ah_massage_headers */
  740                         AH_STATINC(AH_STAT_HDROPS);
  741                         free(tc, M_XDATA);
  742                         crypto_freereq(crp);
  743                         return error;
  744                 }
  745         }
  746 
  747         /* Crypto operation descriptor. */
  748         crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
  749         crp->crp_flags = CRYPTO_F_IMBUF;
  750         crp->crp_buf = m;
  751         crp->crp_callback = ah_input_cb;
  752         crp->crp_sid = sav->tdb_cryptoid;
  753         crp->crp_opaque = tc;
  754 
  755         /* These are passed as-is to the callback. */
  756         tc->tc_spi = sav->spi;
  757         tc->tc_dst = sav->sah->saidx.dst;
  758         tc->tc_proto = sav->sah->saidx.proto;
  759         tc->tc_nxt = ah->ah_nxt;
  760         tc->tc_protoff = protoff;
  761         tc->tc_skip = skip;
  762         tc->tc_ptr = mtag; /* Save the mtag we've identified. */
  763 
  764         DPRINTF(("ah: hash over %d bytes, skip %d: "
  765                  "crda len %d skip %d inject %d\n",
  766                  crp->crp_ilen, tc->tc_skip,
  767                  crda->crd_len, crda->crd_skip, crda->crd_inject));
  768 
  769         if (mtag == NULL)
  770                 return crypto_dispatch(crp);
  771         else
  772                 return ah_input_cb(crp);
  773 }
  774 
  775 #ifdef INET6
  776 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do {              \
  777         if (saidx->dst.sa.sa_family == AF_INET6) {                           \
  778                 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \
  779         } else {                                                             \
  780                 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \
  781         }                                                                    \
  782 } while (0)
  783 #else
  784 #define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag)                   \
  785         (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag))
  786 #endif
  787 
  788 /*
  789  * AH input callback from the crypto driver.
  790  */
  791 static int
  792 ah_input_cb(struct cryptop *crp)
  793 {
  794         int rplen, error, skip, protoff;
  795         unsigned char calc[AH_ALEN_MAX];
  796         struct mbuf *m;
  797         struct cryptodesc *crd;
  798         struct auth_hash *ahx;
  799         struct tdb_crypto *tc;
  800         struct m_tag *mtag;
  801         struct secasvar *sav;
  802         struct secasindex *saidx;
  803         u_int8_t nxt;
  804         char *ptr;
  805         int s, authsize;
  806         u_int16_t dport = 0;
  807         u_int16_t sport = 0;
  808 #ifdef IPSEC_NAT_T
  809         struct m_tag * tag = NULL;
  810 #endif
  811 
  812         crd = crp->crp_desc;
  813 
  814         tc = (struct tdb_crypto *) crp->crp_opaque;
  815         IPSEC_ASSERT(tc != NULL, ("ah_input_cb: null opaque crypto data area!"));
  816         skip = tc->tc_skip;
  817         nxt = tc->tc_nxt;
  818         protoff = tc->tc_protoff;
  819         mtag = (struct m_tag *) tc->tc_ptr;
  820         m = (struct mbuf *) crp->crp_buf;
  821 
  822 
  823 #ifdef IPSEC_NAT_T
  824         /* find the source port for NAT-T */
  825         if ((tag = m_tag_find(m, PACKET_TAG_IPSEC_NAT_T_PORTS, NULL))) {
  826                 sport = ((u_int16_t *)(tag + 1))[0];
  827                 dport = ((u_int16_t *)(tag + 1))[1];
  828         }
  829 #endif
  830 
  831         s = splsoftnet();
  832 
  833         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, sport, dport);
  834         if (sav == NULL) {
  835                 AH_STATINC(AH_STAT_NOTDB);
  836                 DPRINTF(("ah_input_cb: SA expired while in crypto\n"));
  837                 error = ENOBUFS;                /*XXX*/
  838                 goto bad;
  839         }
  840 
  841         saidx = &sav->sah->saidx;
  842         IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
  843                 saidx->dst.sa.sa_family == AF_INET6,
  844                 ("ah_input_cb: unexpected protocol family %u",
  845                  saidx->dst.sa.sa_family));
  846 
  847         ahx = (struct auth_hash *) sav->tdb_authalgxform;
  848 
  849         /* Check for crypto errors. */
  850         if (crp->crp_etype) {
  851                 if (sav->tdb_cryptoid != 0)
  852                         sav->tdb_cryptoid = crp->crp_sid;
  853 
  854                 if (crp->crp_etype == EAGAIN)
  855                         return crypto_dispatch(crp);
  856 
  857                 AH_STATINC(AH_STAT_NOXFORM);
  858                 DPRINTF(("ah_input_cb: crypto error %d\n", crp->crp_etype));
  859                 error = crp->crp_etype;
  860                 goto bad;
  861         } else {
  862                 AH_STATINC(AH_STAT_HIST + sav->alg_auth);
  863                 crypto_freereq(crp);            /* No longer needed. */
  864                 crp = NULL;
  865         }
  866 
  867         /* Shouldn't happen... */
  868         if (m == NULL) {
  869                 AH_STATINC(AH_STAT_CRYPTO);
  870                 DPRINTF(("ah_input_cb: bogus returned buffer from crypto\n"));
  871                 error = EINVAL;
  872                 goto bad;
  873         }
  874 
  875         /* Figure out header size. */
  876         rplen = HDRSIZE(sav);
  877         authsize = AUTHSIZE(sav);
  878 
  879         if (ipsec_debug)
  880           bzero(calc, sizeof(calc));
  881 
  882         /* Copy authenticator off the packet. */
  883         m_copydata(m, skip + rplen, authsize, calc);
  884 
  885         /*
  886          * If we have an mtag, we don't need to verify the authenticator --
  887          * it has been verified by an IPsec-aware NIC.
  888          */
  889         if (mtag == NULL) {
  890                 ptr = (char *) (tc + 1);
  891 
  892                 /* Verify authenticator. */
  893                 if (bcmp(ptr + skip + rplen, calc, authsize)) {
  894                         u_int8_t *pppp = ptr + skip+rplen;
  895                         DPRINTF(("ah_input: authentication hash mismatch " \
  896                             "over %d bytes " \
  897                             "for packet in SA %s/%08lx:\n" \
  898                     "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x, " \
  899                     "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
  900                             authsize,
  901                             ipsec_address(&saidx->dst),
  902                             (u_long) ntohl(sav->spi),
  903                                  calc[0], calc[1], calc[2], calc[3],
  904                                  calc[4], calc[5], calc[6], calc[7],
  905                                  calc[8], calc[9], calc[10], calc[11],
  906                                  pppp[0], pppp[1], pppp[2], pppp[3],
  907                                  pppp[4], pppp[5], pppp[6], pppp[7],
  908                                  pppp[8], pppp[9], pppp[10], pppp[11]
  909                                  ));
  910                         AH_STATINC(AH_STAT_BADAUTH);
  911                         error = EACCES;
  912                         goto bad;
  913                 }
  914 
  915                 /* Fix the Next Protocol field. */
  916                 ((u_int8_t *) ptr)[protoff] = nxt;
  917 
  918                 /* Copyback the saved (uncooked) network headers. */
  919                 m_copyback(m, 0, skip, ptr);
  920         } else {
  921                 /* Fix the Next Protocol field. */
  922                 m_copyback(m, protoff, sizeof(u_int8_t), &nxt);
  923         }
  924 
  925         free(tc, M_XDATA), tc = NULL;                   /* No longer needed */
  926 
  927         /*
  928          * Header is now authenticated.
  929          */
  930         m->m_flags |= M_AUTHIPHDR|M_AUTHIPDGM;
  931 
  932         /*
  933          * Update replay sequence number, if appropriate.
  934          */
  935         if (sav->replay) {
  936                 u_int32_t seq;
  937 
  938                 m_copydata(m, skip + offsetof(struct newah, ah_seq),
  939                            sizeof (seq), &seq);
  940                 if (ipsec_updatereplay(ntohl(seq), sav)) {
  941                         AH_STATINC(AH_STAT_REPLAY);
  942                         error = ENOBUFS;                        /*XXX as above*/
  943                         goto bad;
  944                 }
  945         }
  946 
  947         /*
  948          * Remove the AH header and authenticator from the mbuf.
  949          */
  950         error = m_striphdr(m, skip, rplen + authsize);
  951         if (error) {
  952                 DPRINTF(("ah_input_cb: mangled mbuf chain for SA %s/%08lx\n",
  953                     ipsec_address(&saidx->dst), (u_long) ntohl(sav->spi)));
  954 
  955                 AH_STATINC(AH_STAT_HDROPS);
  956                 goto bad;
  957         }
  958 
  959         IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag);
  960 
  961         KEY_FREESAV(&sav);
  962         splx(s);
  963         return error;
  964 bad:
  965         if (sav)
  966                 KEY_FREESAV(&sav);
  967         splx(s);
  968         if (m != NULL)
  969                 m_freem(m);
  970         if (tc != NULL)
  971                 free(tc, M_XDATA);
  972         if (crp != NULL)
  973                 crypto_freereq(crp);
  974         return error;
  975 }
  976 
  977 /*
  978  * AH output routine, called by ipsec[46]_process_packet().
  979  */
  980 static int
  981 ah_output(
  982     struct mbuf *m,
  983     struct ipsecrequest *isr,
  984     struct mbuf **mp,
  985     int skip,
  986     int protoff
  987 )
  988 {
  989         struct secasvar *sav;
  990         struct auth_hash *ahx;
  991         struct cryptodesc *crda;
  992         struct tdb_crypto *tc;
  993         struct mbuf *mi;
  994         struct cryptop *crp;
  995         u_int16_t iplen;
  996         int error, rplen, authsize, maxpacketsize, roff;
  997         u_int8_t prot;
  998         struct newah *ah;
  999 
 1000         IPSEC_SPLASSERT_SOFTNET("ah_output");
 1001 
 1002         sav = isr->sav;
 1003         IPSEC_ASSERT(sav != NULL, ("ah_output: null SA"));
 1004         ahx = sav->tdb_authalgxform;
 1005         IPSEC_ASSERT(ahx != NULL, ("ah_output: null authentication xform"));
 1006 
 1007         AH_STATINC(AH_STAT_OUTPUT);
 1008 
 1009         /* Figure out header size. */
 1010         rplen = HDRSIZE(sav);
 1011 
 1012         /* Check for maximum packet size violations. */
 1013         switch (sav->sah->saidx.dst.sa.sa_family) {
 1014 #ifdef INET
 1015         case AF_INET:
 1016                 maxpacketsize = IP_MAXPACKET;
 1017                 break;
 1018 #endif /* INET */
 1019 #ifdef INET6
 1020         case AF_INET6:
 1021                 maxpacketsize = IPV6_MAXPACKET;
 1022                 break;
 1023 #endif /* INET6 */
 1024         default:
 1025                 DPRINTF(("ah_output: unknown/unsupported protocol "
 1026                     "family %u, SA %s/%08lx\n",
 1027                     sav->sah->saidx.dst.sa.sa_family,
 1028                     ipsec_address(&sav->sah->saidx.dst),
 1029                     (u_long) ntohl(sav->spi)));
 1030                 AH_STATINC(AH_STAT_NOPF);
 1031                 error = EPFNOSUPPORT;
 1032                 goto bad;
 1033         }
 1034         authsize = AUTHSIZE(sav);
 1035         if (rplen + authsize + m->m_pkthdr.len > maxpacketsize) {
 1036                 DPRINTF(("ah_output: packet in SA %s/%08lx got too big "
 1037                     "(len %u, max len %u)\n",
 1038                     ipsec_address(&sav->sah->saidx.dst),
 1039                     (u_long) ntohl(sav->spi),
 1040                     rplen + authsize + m->m_pkthdr.len, maxpacketsize));
 1041                 AH_STATINC(AH_STAT_TOOBIG);
 1042                 error = EMSGSIZE;
 1043                 goto bad;
 1044         }
 1045 
 1046         /* Update the counters. */
 1047         AH_STATADD(AH_STAT_OBYTES, m->m_pkthdr.len - skip);
 1048 
 1049         m = m_clone(m);
 1050         if (m == NULL) {
 1051                 DPRINTF(("ah_output: cannot clone mbuf chain, SA %s/%08lx\n",
 1052                     ipsec_address(&sav->sah->saidx.dst),
 1053                     (u_long) ntohl(sav->spi)));
 1054                 AH_STATINC(AH_STAT_HDROPS);
 1055                 error = ENOBUFS;
 1056                 goto bad;
 1057         }
 1058 
 1059         /* Inject AH header. */
 1060         mi = m_makespace(m, skip, rplen + authsize, &roff);
 1061         if (mi == NULL) {
 1062                 DPRINTF(("ah_output: failed to inject %u byte AH header for SA "
 1063                     "%s/%08lx\n",
 1064                     rplen + authsize,
 1065                     ipsec_address(&sav->sah->saidx.dst),
 1066                     (u_long) ntohl(sav->spi)));
 1067                 AH_STATINC(AH_STAT_HDROPS);     /*XXX differs from openbsd */
 1068                 error = ENOBUFS;
 1069                 goto bad;
 1070         }
 1071 
 1072         /*
 1073          * The AH header is guaranteed by m_makespace() to be in
 1074          * contiguous memory, at roff bytes offset into the returned mbuf.
 1075          */
 1076         ah = (struct newah *)(mtod(mi, char *) + roff);
 1077 
 1078         /* Initialize the AH header. */
 1079         m_copydata(m, protoff, sizeof(u_int8_t), (char *) &ah->ah_nxt);
 1080         ah->ah_len = (rplen + authsize - sizeof(struct ah)) / sizeof(u_int32_t);
 1081         ah->ah_reserve = 0;
 1082         ah->ah_spi = sav->spi;
 1083 
 1084         /* Zeroize authenticator. */
 1085         m_copyback(m, skip + rplen, authsize, ipseczeroes);
 1086 
 1087         /* Insert packet replay counter, as requested.  */
 1088         if (sav->replay) {
 1089                 if (sav->replay->count == ~0 &&
 1090                     (sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
 1091                         DPRINTF(("ah_output: replay counter wrapped for SA "
 1092                                 "%s/%08lx\n",
 1093                                 ipsec_address(&sav->sah->saidx.dst),
 1094                                 (u_long) ntohl(sav->spi)));
 1095                         AH_STATINC(AH_STAT_WRAP);
 1096                         error = EINVAL;
 1097                         goto bad;
 1098                 }
 1099 #ifdef IPSEC_DEBUG
 1100                 /* Emulate replay attack when ipsec_replay is TRUE. */
 1101                 if (!ipsec_replay)
 1102 #endif
 1103                         sav->replay->count++;
 1104                 ah->ah_seq = htonl(sav->replay->count);
 1105         }
 1106 
 1107         /* Get crypto descriptors. */
 1108         crp = crypto_getreq(1);
 1109         if (crp == NULL) {
 1110                 DPRINTF(("ah_output: failed to acquire crypto descriptors\n"));
 1111                 AH_STATINC(AH_STAT_CRYPTO);
 1112                 error = ENOBUFS;
 1113                 goto bad;
 1114         }
 1115 
 1116         crda = crp->crp_desc;
 1117 
 1118         crda->crd_skip = 0;
 1119         crda->crd_inject = skip + rplen;
 1120         crda->crd_len = m->m_pkthdr.len;
 1121 
 1122         /* Authentication operation. */
 1123         crda->crd_alg = ahx->type;
 1124         crda->crd_key = _KEYBUF(sav->key_auth);
 1125         crda->crd_klen = _KEYBITS(sav->key_auth);
 1126 
 1127         /* Allocate IPsec-specific opaque crypto info. */
 1128         tc = (struct tdb_crypto *) malloc(
 1129                 sizeof(struct tdb_crypto) + skip, M_XDATA, M_NOWAIT|M_ZERO);
 1130         if (tc == NULL) {
 1131                 crypto_freereq(crp);
 1132                 DPRINTF(("ah_output: failed to allocate tdb_crypto\n"));
 1133                 AH_STATINC(AH_STAT_CRYPTO);
 1134                 error = ENOBUFS;
 1135                 goto bad;
 1136         }
 1137 
 1138         /* Save the skipped portion of the packet. */
 1139         m_copydata(m, 0, skip, (tc + 1));
 1140 
 1141         /*
 1142          * Fix IP header length on the header used for
 1143          * authentication. We don't need to fix the original
 1144          * header length as it will be fixed by our caller.
 1145          */
 1146         switch (sav->sah->saidx.dst.sa.sa_family) {
 1147 #ifdef INET
 1148         case AF_INET:
 1149                 bcopy(((char *)(tc + 1)) +
 1150                     offsetof(struct ip, ip_len),
 1151                     &iplen, sizeof(u_int16_t));
 1152                 iplen = htons(ntohs(iplen) + rplen + authsize);
 1153                 m_copyback(m, offsetof(struct ip, ip_len),
 1154                     sizeof(u_int16_t), &iplen);
 1155                 break;
 1156 #endif /* INET */
 1157 
 1158 #ifdef INET6
 1159         case AF_INET6:
 1160                 bcopy(((char *)(tc + 1)) +
 1161                     offsetof(struct ip6_hdr, ip6_plen),
 1162                     &iplen, sizeof(u_int16_t));
 1163                 iplen = htons(ntohs(iplen) + rplen + authsize);
 1164                 m_copyback(m, offsetof(struct ip6_hdr, ip6_plen),
 1165                     sizeof(u_int16_t), &iplen);
 1166                 break;
 1167 #endif /* INET6 */
 1168         }
 1169 
 1170         /* Fix the Next Header field in saved header. */
 1171         ((u_int8_t *) (tc + 1))[protoff] = IPPROTO_AH;
 1172 
 1173         /* Update the Next Protocol field in the IP header. */
 1174         prot = IPPROTO_AH;
 1175         m_copyback(m, protoff, sizeof(u_int8_t), &prot);
 1176 
 1177         /* "Massage" the packet headers for crypto processing. */
 1178         error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
 1179                         skip, ahx->type, 1);
 1180         if (error != 0) {
 1181                 m = NULL;       /* mbuf was free'd by ah_massage_headers. */
 1182                 free(tc, M_XDATA);
 1183                 crypto_freereq(crp);
 1184                 goto bad;
 1185         }
 1186 
 1187         /* Crypto operation descriptor. */
 1188         crp->crp_ilen = m->m_pkthdr.len; /* Total input length. */
 1189         crp->crp_flags = CRYPTO_F_IMBUF;
 1190         crp->crp_buf = m;
 1191         crp->crp_callback = ah_output_cb;
 1192         crp->crp_sid = sav->tdb_cryptoid;
 1193         crp->crp_opaque = tc;
 1194 
 1195         /* These are passed as-is to the callback. */
 1196         tc->tc_isr = isr;
 1197         tc->tc_spi = sav->spi;
 1198         tc->tc_dst = sav->sah->saidx.dst;
 1199         tc->tc_proto = sav->sah->saidx.proto;
 1200         tc->tc_skip = skip;
 1201         tc->tc_protoff = protoff;
 1202 
 1203         return crypto_dispatch(crp);
 1204 bad:
 1205         if (m)
 1206                 m_freem(m);
 1207         return (error);
 1208 }
 1209 
 1210 /*
 1211  * AH output callback from the crypto driver.
 1212  */
 1213 static int
 1214 ah_output_cb(struct cryptop *crp)
 1215 {
 1216         int skip, protoff, error;
 1217         struct tdb_crypto *tc;
 1218         struct ipsecrequest *isr;
 1219         struct secasvar *sav;
 1220         struct mbuf *m;
 1221         void *ptr;
 1222         int s, err;
 1223 
 1224         tc = (struct tdb_crypto *) crp->crp_opaque;
 1225         IPSEC_ASSERT(tc != NULL, ("ah_output_cb: null opaque data area!"));
 1226         skip = tc->tc_skip;
 1227         protoff = tc->tc_protoff;
 1228         ptr = (tc + 1);
 1229         m = (struct mbuf *) crp->crp_buf;
 1230 
 1231         s = splsoftnet();
 1232 
 1233         isr = tc->tc_isr;
 1234         sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi, 0, 0);
 1235         if (sav == NULL) {
 1236                 AH_STATINC(AH_STAT_NOTDB);
 1237                 DPRINTF(("ah_output_cb: SA expired while in crypto\n"));
 1238                 error = ENOBUFS;                /*XXX*/
 1239                 goto bad;
 1240         }
 1241         IPSEC_ASSERT(isr->sav == sav, ("ah_output_cb: SA changed\n"));
 1242 
 1243         /* Check for crypto errors. */
 1244         if (crp->crp_etype) {
 1245                 if (sav->tdb_cryptoid != 0)
 1246                         sav->tdb_cryptoid = crp->crp_sid;
 1247 
 1248                 if (crp->crp_etype == EAGAIN) {
 1249                         KEY_FREESAV(&sav);
 1250                         splx(s);
 1251                         return crypto_dispatch(crp);
 1252                 }
 1253 
 1254                 AH_STATINC(AH_STAT_NOXFORM);
 1255                 DPRINTF(("ah_output_cb: crypto error %d\n", crp->crp_etype));
 1256                 error = crp->crp_etype;
 1257                 goto bad;
 1258         }
 1259 
 1260         /* Shouldn't happen... */
 1261         if (m == NULL) {
 1262                 AH_STATINC(AH_STAT_CRYPTO);
 1263                 DPRINTF(("ah_output_cb: bogus returned buffer from crypto\n"));
 1264                 error = EINVAL;
 1265                 goto bad;
 1266         }
 1267         AH_STATINC(AH_STAT_HIST + sav->alg_auth);
 1268 
 1269         /*
 1270          * Copy original headers (with the new protocol number) back
 1271          * in place.
 1272          */
 1273         m_copyback(m, 0, skip, ptr);
 1274 
 1275         /* No longer needed. */
 1276         free(tc, M_XDATA);
 1277         crypto_freereq(crp);
 1278 
 1279 #ifdef IPSEC_DEBUG
 1280         /* Emulate man-in-the-middle attack when ipsec_integrity is TRUE. */
 1281         if (ipsec_integrity) {
 1282                 int alen;
 1283 
 1284                 /*
 1285                  * Corrupt HMAC if we want to test integrity verification of
 1286                  * the other side.
 1287                  */
 1288                 alen = AUTHSIZE(sav);
 1289                 m_copyback(m, m->m_pkthdr.len - alen, alen, ipseczeroes);
 1290         }
 1291 #endif
 1292 
 1293         /* NB: m is reclaimed by ipsec_process_done. */
 1294         err = ipsec_process_done(m, isr);
 1295         KEY_FREESAV(&sav);
 1296         splx(s);
 1297         return err;
 1298 bad:
 1299         if (sav)
 1300                 KEY_FREESAV(&sav);
 1301         splx(s);
 1302         if (m)
 1303                 m_freem(m);
 1304         free(tc, M_XDATA);
 1305         crypto_freereq(crp);
 1306         return error;
 1307 }
 1308 
 1309 static struct xformsw ah_xformsw = {
 1310         XF_AH,          XFT_AUTH,       "IPsec AH",
 1311         ah_init,        ah_zeroize,     ah_input,       ah_output,
 1312         NULL,
 1313 };
 1314 
 1315 INITFN void
 1316 ah_attach(void)
 1317 {
 1318         ahstat_percpu = percpu_alloc(sizeof(uint64_t) * AH_NSTATS);
 1319         xform_register(&ah_xformsw);
 1320 }
 1321 
 1322 #ifdef __FreeBSD__
 1323 SYSINIT(ah_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ah_attach, NULL);
 1324 #endif

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