The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/esp_input.c

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    1 /*      $FreeBSD: releng/5.1/sys/netinet6/esp_input.c 111888 2003-03-04 23:19:55Z jlemon $      */
    2 /*      $KAME: esp_input.c,v 1.62 2002/01/07 11:39:57 kjc Exp $ */
    3 
    4 /*
    5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. Neither the name of the project nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  */
   32 
   33 /*
   34  * RFC1827/2406 Encapsulated Security Payload.
   35  */
   36 
   37 #include "opt_inet.h"
   38 #include "opt_inet6.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/mbuf.h>
   43 #include <sys/domain.h>
   44 #include <sys/protosw.h>
   45 #include <sys/socket.h>
   46 #include <sys/errno.h>
   47 #include <sys/time.h>
   48 #include <sys/syslog.h>
   49 
   50 #include <net/if.h>
   51 #include <net/route.h>
   52 #include <net/netisr.h>
   53 #include <machine/cpu.h>
   54 
   55 #include <netinet/in.h>
   56 #include <netinet/in_systm.h>
   57 #include <netinet/ip.h>
   58 #include <netinet/ip_var.h>
   59 #include <netinet/in_var.h>
   60 #include <netinet/ip_ecn.h>
   61 #ifdef INET6
   62 #include <netinet6/ip6_ecn.h>
   63 #endif
   64 
   65 #ifdef INET6
   66 #include <netinet/ip6.h>
   67 #include <netinet/in_pcb.h>
   68 #include <netinet6/in6_pcb.h>
   69 #include <netinet6/ip6_var.h>
   70 #include <netinet/icmp6.h>
   71 #include <netinet6/ip6protosw.h>
   72 #endif
   73 
   74 #include <netinet6/ipsec.h>
   75 #ifdef INET6
   76 #include <netinet6/ipsec6.h>
   77 #endif
   78 #include <netinet6/ah.h>
   79 #ifdef INET6
   80 #include <netinet6/ah6.h>
   81 #endif
   82 #include <netinet6/esp.h>
   83 #ifdef INET6
   84 #include <netinet6/esp6.h>
   85 #endif
   86 #include <netkey/key.h>
   87 #include <netkey/keydb.h>
   88 #include <netkey/key_debug.h>
   89 
   90 #include <machine/stdarg.h>
   91 
   92 #include <net/net_osdep.h>
   93 
   94 #define IPLEN_FLIPPED
   95 
   96 #define ESPMAXLEN \
   97         (sizeof(struct esp) < sizeof(struct newesp) \
   98                 ? sizeof(struct newesp) : sizeof(struct esp))
   99 
  100 #ifdef INET
  101 extern struct protosw inetsw[];
  102 
  103 void
  104 esp4_input(m, off)
  105         struct mbuf *m;
  106         int off;
  107 {
  108         struct ip *ip;
  109         struct esp *esp;
  110         struct esptail esptail;
  111         u_int32_t spi;
  112         struct secasvar *sav = NULL;
  113         size_t taillen;
  114         u_int16_t nxt;
  115         const struct esp_algorithm *algo;
  116         int ivlen;
  117         size_t hlen;
  118         size_t esplen;
  119         int proto;
  120 
  121         /* sanity check for alignment. */
  122         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
  123                 ipseclog((LOG_ERR, "IPv4 ESP input: packet alignment problem "
  124                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
  125                 ipsecstat.in_inval++;
  126                 goto bad;
  127         }
  128 
  129         if (m->m_len < off + ESPMAXLEN) {
  130                 m = m_pullup(m, off + ESPMAXLEN);
  131                 if (!m) {
  132                         ipseclog((LOG_DEBUG,
  133                             "IPv4 ESP input: can't pullup in esp4_input\n"));
  134                         ipsecstat.in_inval++;
  135                         goto bad;
  136                 }
  137         }
  138 
  139         ip = mtod(m, struct ip *);
  140         proto = ip->ip_p;
  141         esp = (struct esp *)(((u_int8_t *)ip) + off);
  142 #ifdef _IP_VHL
  143         hlen = IP_VHL_HL(ip->ip_vhl) << 2;
  144 #else
  145         hlen = ip->ip_hl << 2;
  146 #endif
  147 
  148         /* find the sassoc. */
  149         spi = esp->esp_spi;
  150 
  151         if ((sav = key_allocsa(AF_INET,
  152                               (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst,
  153                               IPPROTO_ESP, spi)) == 0) {
  154                 ipseclog((LOG_WARNING,
  155                     "IPv4 ESP input: no key association found for spi %u\n",
  156                     (u_int32_t)ntohl(spi)));
  157                 ipsecstat.in_nosa++;
  158                 goto bad;
  159         }
  160         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  161                 printf("DP esp4_input called to allocate SA:%p\n", sav));
  162         if (sav->state != SADB_SASTATE_MATURE
  163          && sav->state != SADB_SASTATE_DYING) {
  164                 ipseclog((LOG_DEBUG,
  165                     "IPv4 ESP input: non-mature/dying SA found for spi %u\n",
  166                     (u_int32_t)ntohl(spi)));
  167                 ipsecstat.in_badspi++;
  168                 goto bad;
  169         }
  170         algo = esp_algorithm_lookup(sav->alg_enc);
  171         if (!algo) {
  172                 ipseclog((LOG_DEBUG, "IPv4 ESP input: "
  173                     "unsupported encryption algorithm for spi %u\n",
  174                     (u_int32_t)ntohl(spi)));
  175                 ipsecstat.in_badspi++;
  176                 goto bad;
  177         }
  178 
  179         /* check if we have proper ivlen information */
  180         ivlen = sav->ivlen;
  181         if (ivlen < 0) {
  182                 ipseclog((LOG_ERR, "inproper ivlen in IPv4 ESP input: %s %s\n",
  183                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  184                 ipsecstat.in_inval++;
  185                 goto bad;
  186         }
  187 
  188         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
  189          && (sav->alg_auth && sav->key_auth)))
  190                 goto noreplaycheck;
  191 
  192         if (sav->alg_auth == SADB_X_AALG_NULL ||
  193             sav->alg_auth == SADB_AALG_NONE)
  194                 goto noreplaycheck;
  195 
  196         /*
  197          * check for sequence number.
  198          */
  199         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
  200                 ; /* okey */
  201         else {
  202                 ipsecstat.in_espreplay++;
  203                 ipseclog((LOG_WARNING,
  204                     "replay packet in IPv4 ESP input: %s %s\n",
  205                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  206                 goto bad;
  207         }
  208 
  209         /* check ICV */
  210     {
  211         u_char sum0[AH_MAXSUMSIZE];
  212         u_char sum[AH_MAXSUMSIZE];
  213         const struct ah_algorithm *sumalgo;
  214         size_t siz;
  215 
  216         sumalgo = ah_algorithm_lookup(sav->alg_auth);
  217         if (!sumalgo)
  218                 goto noreplaycheck;
  219         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
  220         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
  221                 ipsecstat.in_inval++;
  222                 goto bad;
  223         }
  224         if (AH_MAXSUMSIZE < siz) {
  225                 ipseclog((LOG_DEBUG,
  226                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
  227                     (u_long)siz));
  228                 ipsecstat.in_inval++;
  229                 goto bad;
  230         }
  231 
  232         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
  233 
  234         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
  235                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
  236                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  237                 ipsecstat.in_espauthfail++;
  238                 goto bad;
  239         }
  240 
  241         if (bcmp(sum0, sum, siz) != 0) {
  242                 ipseclog((LOG_WARNING, "auth fail in IPv4 ESP input: %s %s\n",
  243                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  244                 ipsecstat.in_espauthfail++;
  245                 goto bad;
  246         }
  247 
  248         /* strip off the authentication data */
  249         m_adj(m, -siz);
  250         ip = mtod(m, struct ip *);
  251 #ifdef IPLEN_FLIPPED
  252         ip->ip_len = ip->ip_len - siz;
  253 #else
  254         ip->ip_len = htons(ntohs(ip->ip_len) - siz);
  255 #endif
  256         m->m_flags |= M_AUTHIPDGM;
  257         ipsecstat.in_espauthsucc++;
  258     }
  259 
  260         /*
  261          * update sequence number.
  262          */
  263         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
  264                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
  265                         ipsecstat.in_espreplay++;
  266                         goto bad;
  267                 }
  268         }
  269 
  270 noreplaycheck:
  271 
  272         /* process main esp header. */
  273         if (sav->flags & SADB_X_EXT_OLD) {
  274                 /* RFC 1827 */
  275                 esplen = sizeof(struct esp);
  276         } else {
  277                 /* RFC 2406 */
  278                 if (sav->flags & SADB_X_EXT_DERIV)
  279                         esplen = sizeof(struct esp);
  280                 else
  281                         esplen = sizeof(struct newesp);
  282         }
  283 
  284         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
  285                 ipseclog((LOG_WARNING,
  286                     "IPv4 ESP input: packet too short\n"));
  287                 ipsecstat.in_inval++;
  288                 goto bad;
  289         }
  290 
  291         if (m->m_len < off + esplen + ivlen) {
  292                 m = m_pullup(m, off + esplen + ivlen);
  293                 if (!m) {
  294                         ipseclog((LOG_DEBUG,
  295                             "IPv4 ESP input: can't pullup in esp4_input\n"));
  296                         ipsecstat.in_inval++;
  297                         goto bad;
  298                 }
  299         }
  300 
  301         /*
  302          * pre-compute and cache intermediate key
  303          */
  304         if (esp_schedule(algo, sav) != 0) {
  305                 ipsecstat.in_inval++;
  306                 goto bad;
  307         }
  308 
  309         /*
  310          * decrypt the packet.
  311          */
  312         if (!algo->decrypt)
  313                 panic("internal error: no decrypt function");
  314         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
  315                 /* m is already freed */
  316                 m = NULL;
  317                 ipseclog((LOG_ERR, "decrypt fail in IPv4 ESP input: %s\n",
  318                     ipsec_logsastr(sav)));
  319                 ipsecstat.in_inval++;
  320                 goto bad;
  321         }
  322         ipsecstat.in_esphist[sav->alg_enc]++;
  323 
  324         m->m_flags |= M_DECRYPTED;
  325 
  326         /*
  327          * find the trailer of the ESP.
  328          */
  329         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
  330              (caddr_t)&esptail);
  331         nxt = esptail.esp_nxt;
  332         taillen = esptail.esp_padlen + sizeof(esptail);
  333 
  334         if (m->m_pkthdr.len < taillen
  335          || m->m_pkthdr.len - taillen < hlen) { /* ? */
  336                 ipseclog((LOG_WARNING,
  337                     "bad pad length in IPv4 ESP input: %s %s\n",
  338                     ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  339                 ipsecstat.in_inval++;
  340                 goto bad;
  341         }
  342 
  343         /* strip off the trailing pad area. */
  344         m_adj(m, -taillen);
  345 
  346 #ifdef IPLEN_FLIPPED
  347         ip->ip_len = ip->ip_len - taillen;
  348 #else
  349         ip->ip_len = htons(ntohs(ip->ip_len) - taillen);
  350 #endif
  351 
  352         /* was it transmitted over the IPsec tunnel SA? */
  353         if (ipsec4_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
  354                 /*
  355                  * strip off all the headers that precedes ESP header.
  356                  *      IP4 xx ESP IP4' payload -> IP4' payload
  357                  *
  358                  * XXX more sanity checks
  359                  * XXX relationship with gif?
  360                  */
  361                 u_int8_t tos;
  362 
  363                 tos = ip->ip_tos;
  364                 m_adj(m, off + esplen + ivlen);
  365                 if (m->m_len < sizeof(*ip)) {
  366                         m = m_pullup(m, sizeof(*ip));
  367                         if (!m) {
  368                                 ipsecstat.in_inval++;
  369                                 goto bad;
  370                         }
  371                 }
  372                 ip = mtod(m, struct ip *);
  373                 /* ECN consideration. */
  374                 ip_ecn_egress(ip4_ipsec_ecn, &tos, &ip->ip_tos);
  375                 if (!key_checktunnelsanity(sav, AF_INET,
  376                             (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst)) {
  377                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
  378                             "in IPv4 ESP input: %s %s\n",
  379                             ipsec4_logpacketstr(ip, spi), ipsec_logsastr(sav)));
  380                         ipsecstat.in_inval++;
  381                         goto bad;
  382                 }
  383 
  384                 key_sa_recordxfer(sav, m);
  385                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 ||
  386                     ipsec_addhist(m, IPPROTO_IPV4, 0) != 0) {
  387                         ipsecstat.in_nomem++;
  388                         goto bad;
  389                 }
  390 
  391                 if (! netisr_queue(NETISR_IP, m)) {
  392                         ipsecstat.in_inval++;
  393                         m = NULL;
  394                         goto bad;
  395                 }
  396                 m = NULL;
  397                 nxt = IPPROTO_DONE;
  398         } else {
  399                 /*
  400                  * strip off ESP header and IV.
  401                  * even in m_pulldown case, we need to strip off ESP so that
  402                  * we can always compute checksum for AH correctly.
  403                  */
  404                 size_t stripsiz;
  405 
  406                 stripsiz = esplen + ivlen;
  407 
  408                 ip = mtod(m, struct ip *);
  409                 ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), off);
  410                 m->m_data += stripsiz;
  411                 m->m_len -= stripsiz;
  412                 m->m_pkthdr.len -= stripsiz;
  413 
  414                 ip = mtod(m, struct ip *);
  415 #ifdef IPLEN_FLIPPED
  416                 ip->ip_len = ip->ip_len - stripsiz;
  417 #else
  418                 ip->ip_len = htons(ntohs(ip->ip_len) - stripsiz);
  419 #endif
  420                 ip->ip_p = nxt;
  421 
  422                 key_sa_recordxfer(sav, m);
  423                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
  424                         ipsecstat.in_nomem++;
  425                         goto bad;
  426                 }
  427 
  428                 if (nxt != IPPROTO_DONE) {
  429                         if ((inetsw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
  430                             ipsec4_in_reject(m, NULL)) {
  431                                 ipsecstat.in_polvio++;
  432                                 goto bad;
  433                         }
  434                         (*inetsw[ip_protox[nxt]].pr_input)(m, off);
  435                 } else
  436                         m_freem(m);
  437                 m = NULL;
  438         }
  439 
  440         if (sav) {
  441                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  442                         printf("DP esp4_input call free SA:%p\n", sav));
  443                 key_freesav(sav);
  444         }
  445         ipsecstat.in_success++;
  446         return;
  447 
  448 bad:
  449         if (sav) {
  450                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  451                         printf("DP esp4_input call free SA:%p\n", sav));
  452                 key_freesav(sav);
  453         }
  454         if (m)
  455                 m_freem(m);
  456         return;
  457 }
  458 #endif /* INET */
  459 
  460 #ifdef INET6
  461 int
  462 esp6_input(mp, offp, proto)
  463         struct mbuf **mp;
  464         int *offp, proto;
  465 {
  466         struct mbuf *m = *mp;
  467         int off = *offp;
  468         struct ip6_hdr *ip6;
  469         struct esp *esp;
  470         struct esptail esptail;
  471         u_int32_t spi;
  472         struct secasvar *sav = NULL;
  473         size_t taillen;
  474         u_int16_t nxt;
  475         const struct esp_algorithm *algo;
  476         int ivlen;
  477         size_t esplen;
  478 
  479         /* sanity check for alignment. */
  480         if (off % 4 != 0 || m->m_pkthdr.len % 4 != 0) {
  481                 ipseclog((LOG_ERR, "IPv6 ESP input: packet alignment problem "
  482                         "(off=%d, pktlen=%d)\n", off, m->m_pkthdr.len));
  483                 ipsec6stat.in_inval++;
  484                 goto bad;
  485         }
  486 
  487 #ifndef PULLDOWN_TEST
  488         IP6_EXTHDR_CHECK(m, off, ESPMAXLEN, IPPROTO_DONE);
  489         esp = (struct esp *)(mtod(m, caddr_t) + off);
  490 #else
  491         IP6_EXTHDR_GET(esp, struct esp *, m, off, ESPMAXLEN);
  492         if (esp == NULL) {
  493                 ipsec6stat.in_inval++;
  494                 return IPPROTO_DONE;
  495         }
  496 #endif
  497         ip6 = mtod(m, struct ip6_hdr *);
  498 
  499         if (ntohs(ip6->ip6_plen) == 0) {
  500                 ipseclog((LOG_ERR, "IPv6 ESP input: "
  501                     "ESP with IPv6 jumbogram is not supported.\n"));
  502                 ipsec6stat.in_inval++;
  503                 goto bad;
  504         }
  505 
  506         /* find the sassoc. */
  507         spi = esp->esp_spi;
  508 
  509         if ((sav = key_allocsa(AF_INET6,
  510                               (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst,
  511                               IPPROTO_ESP, spi)) == 0) {
  512                 ipseclog((LOG_WARNING,
  513                     "IPv6 ESP input: no key association found for spi %u\n",
  514                     (u_int32_t)ntohl(spi)));
  515                 ipsec6stat.in_nosa++;
  516                 goto bad;
  517         }
  518         KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  519                 printf("DP esp6_input called to allocate SA:%p\n", sav));
  520         if (sav->state != SADB_SASTATE_MATURE
  521          && sav->state != SADB_SASTATE_DYING) {
  522                 ipseclog((LOG_DEBUG,
  523                     "IPv6 ESP input: non-mature/dying SA found for spi %u\n",
  524                     (u_int32_t)ntohl(spi)));
  525                 ipsec6stat.in_badspi++;
  526                 goto bad;
  527         }
  528         algo = esp_algorithm_lookup(sav->alg_enc);
  529         if (!algo) {
  530                 ipseclog((LOG_DEBUG, "IPv6 ESP input: "
  531                     "unsupported encryption algorithm for spi %u\n",
  532                     (u_int32_t)ntohl(spi)));
  533                 ipsec6stat.in_badspi++;
  534                 goto bad;
  535         }
  536 
  537         /* check if we have proper ivlen information */
  538         ivlen = sav->ivlen;
  539         if (ivlen < 0) {
  540                 ipseclog((LOG_ERR, "inproper ivlen in IPv6 ESP input: %s %s\n",
  541                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
  542                 ipsec6stat.in_badspi++;
  543                 goto bad;
  544         }
  545 
  546         if (!((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay
  547          && (sav->alg_auth && sav->key_auth)))
  548                 goto noreplaycheck;
  549 
  550         if (sav->alg_auth == SADB_X_AALG_NULL ||
  551             sav->alg_auth == SADB_AALG_NONE)
  552                 goto noreplaycheck;
  553 
  554         /*
  555          * check for sequence number.
  556          */
  557         if (ipsec_chkreplay(ntohl(((struct newesp *)esp)->esp_seq), sav))
  558                 ; /* okey */
  559         else {
  560                 ipsec6stat.in_espreplay++;
  561                 ipseclog((LOG_WARNING,
  562                     "replay packet in IPv6 ESP input: %s %s\n",
  563                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
  564                 goto bad;
  565         }
  566 
  567         /* check ICV */
  568     {
  569         u_char sum0[AH_MAXSUMSIZE];
  570         u_char sum[AH_MAXSUMSIZE];
  571         const struct ah_algorithm *sumalgo;
  572         size_t siz;
  573 
  574         sumalgo = ah_algorithm_lookup(sav->alg_auth);
  575         if (!sumalgo)
  576                 goto noreplaycheck;
  577         siz = (((*sumalgo->sumsiz)(sav) + 3) & ~(4 - 1));
  578         if (m->m_pkthdr.len < off + ESPMAXLEN + siz) {
  579                 ipsecstat.in_inval++;
  580                 goto bad;
  581         }
  582         if (AH_MAXSUMSIZE < siz) {
  583                 ipseclog((LOG_DEBUG,
  584                     "internal error: AH_MAXSUMSIZE must be larger than %lu\n",
  585                     (u_long)siz));
  586                 ipsec6stat.in_inval++;
  587                 goto bad;
  588         }
  589 
  590         m_copydata(m, m->m_pkthdr.len - siz, siz, &sum0[0]);
  591 
  592         if (esp_auth(m, off, m->m_pkthdr.len - off - siz, sav, sum)) {
  593                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
  594                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
  595                 ipsec6stat.in_espauthfail++;
  596                 goto bad;
  597         }
  598 
  599         if (bcmp(sum0, sum, siz) != 0) {
  600                 ipseclog((LOG_WARNING, "auth fail in IPv6 ESP input: %s %s\n",
  601                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
  602                 ipsec6stat.in_espauthfail++;
  603                 goto bad;
  604         }
  605 
  606         /* strip off the authentication data */
  607         m_adj(m, -siz);
  608         ip6 = mtod(m, struct ip6_hdr *);
  609         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - siz);
  610 
  611         m->m_flags |= M_AUTHIPDGM;
  612         ipsec6stat.in_espauthsucc++;
  613     }
  614 
  615         /*
  616          * update sequence number.
  617          */
  618         if ((sav->flags & SADB_X_EXT_OLD) == 0 && sav->replay) {
  619                 if (ipsec_updatereplay(ntohl(((struct newesp *)esp)->esp_seq), sav)) {
  620                         ipsec6stat.in_espreplay++;
  621                         goto bad;
  622                 }
  623         }
  624 
  625 noreplaycheck:
  626 
  627         /* process main esp header. */
  628         if (sav->flags & SADB_X_EXT_OLD) {
  629                 /* RFC 1827 */
  630                 esplen = sizeof(struct esp);
  631         } else {
  632                 /* RFC 2406 */
  633                 if (sav->flags & SADB_X_EXT_DERIV)
  634                         esplen = sizeof(struct esp);
  635                 else
  636                         esplen = sizeof(struct newesp);
  637         }
  638 
  639         if (m->m_pkthdr.len < off + esplen + ivlen + sizeof(esptail)) {
  640                 ipseclog((LOG_WARNING,
  641                     "IPv6 ESP input: packet too short\n"));
  642                 ipsec6stat.in_inval++;
  643                 goto bad;
  644         }
  645 
  646 #ifndef PULLDOWN_TEST
  647         IP6_EXTHDR_CHECK(m, off, esplen + ivlen, IPPROTO_DONE); /* XXX */
  648 #else
  649         IP6_EXTHDR_GET(esp, struct esp *, m, off, esplen + ivlen);
  650         if (esp == NULL) {
  651                 ipsec6stat.in_inval++;
  652                 m = NULL;
  653                 goto bad;
  654         }
  655 #endif
  656         ip6 = mtod(m, struct ip6_hdr *);        /* set it again just in case */
  657 
  658         /*
  659          * pre-compute and cache intermediate key
  660          */
  661         if (esp_schedule(algo, sav) != 0) {
  662                 ipsec6stat.in_inval++;
  663                 goto bad;
  664         }
  665 
  666         /*
  667          * decrypt the packet.
  668          */
  669         if (!algo->decrypt)
  670                 panic("internal error: no decrypt function");
  671         if ((*algo->decrypt)(m, off, sav, algo, ivlen)) {
  672                 /* m is already freed */
  673                 m = NULL;
  674                 ipseclog((LOG_ERR, "decrypt fail in IPv6 ESP input: %s\n",
  675                     ipsec_logsastr(sav)));
  676                 ipsec6stat.in_inval++;
  677                 goto bad;
  678         }
  679         ipsec6stat.in_esphist[sav->alg_enc]++;
  680 
  681         m->m_flags |= M_DECRYPTED;
  682 
  683         /*
  684          * find the trailer of the ESP.
  685          */
  686         m_copydata(m, m->m_pkthdr.len - sizeof(esptail), sizeof(esptail),
  687              (caddr_t)&esptail);
  688         nxt = esptail.esp_nxt;
  689         taillen = esptail.esp_padlen + sizeof(esptail);
  690 
  691         if (m->m_pkthdr.len < taillen
  692          || m->m_pkthdr.len - taillen < sizeof(struct ip6_hdr)) {       /* ? */
  693                 ipseclog((LOG_WARNING,
  694                     "bad pad length in IPv6 ESP input: %s %s\n",
  695                     ipsec6_logpacketstr(ip6, spi), ipsec_logsastr(sav)));
  696                 ipsec6stat.in_inval++;
  697                 goto bad;
  698         }
  699 
  700         /* strip off the trailing pad area. */
  701         m_adj(m, -taillen);
  702 
  703         ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - taillen);
  704 
  705         /* was it transmitted over the IPsec tunnel SA? */
  706         if (ipsec6_tunnel_validate(m, off + esplen + ivlen, nxt, sav)) {
  707                 /*
  708                  * strip off all the headers that precedes ESP header.
  709                  *      IP6 xx ESP IP6' payload -> IP6' payload
  710                  *
  711                  * XXX more sanity checks
  712                  * XXX relationship with gif?
  713                  */
  714                 u_int32_t flowinfo;     /* net endian */
  715                 flowinfo = ip6->ip6_flow;
  716                 m_adj(m, off + esplen + ivlen);
  717                 if (m->m_len < sizeof(*ip6)) {
  718 #ifndef PULLDOWN_TEST
  719                         /*
  720                          * m_pullup is prohibited in KAME IPv6 input processing
  721                          * but there's no other way!
  722                          */
  723 #else
  724                         /* okay to pullup in m_pulldown style */
  725 #endif
  726                         m = m_pullup(m, sizeof(*ip6));
  727                         if (!m) {
  728                                 ipsec6stat.in_inval++;
  729                                 goto bad;
  730                         }
  731                 }
  732                 ip6 = mtod(m, struct ip6_hdr *);
  733                 /* ECN consideration. */
  734                 ip6_ecn_egress(ip6_ipsec_ecn, &flowinfo, &ip6->ip6_flow);
  735                 if (!key_checktunnelsanity(sav, AF_INET6,
  736                             (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst)) {
  737                         ipseclog((LOG_ERR, "ipsec tunnel address mismatch "
  738                             "in IPv6 ESP input: %s %s\n",
  739                             ipsec6_logpacketstr(ip6, spi),
  740                             ipsec_logsastr(sav)));
  741                         ipsec6stat.in_inval++;
  742                         goto bad;
  743                 }
  744 
  745                 key_sa_recordxfer(sav, m);
  746                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0 || 
  747                     ipsec_addhist(m, IPPROTO_IPV6, 0) != 0) {
  748                         ipsec6stat.in_nomem++;
  749                         goto bad;
  750                 }
  751 
  752                 if (! netisr_queue(NETISR_IPV6, m)) {
  753                         ipsec6stat.in_inval++;
  754                         m = NULL;
  755                         goto bad;
  756                 }
  757                 m = NULL;
  758                 nxt = IPPROTO_DONE;
  759         } else {
  760                 /*
  761                  * strip off ESP header and IV.
  762                  * even in m_pulldown case, we need to strip off ESP so that
  763                  * we can always compute checksum for AH correctly.
  764                  */
  765                 size_t stripsiz;
  766                 char *prvnxtp;
  767 
  768                 /*
  769                  * Set the next header field of the previous header correctly.
  770                  */
  771                 prvnxtp = ip6_get_prevhdr(m, off); /* XXX */
  772                 *prvnxtp = nxt;
  773 
  774                 stripsiz = esplen + ivlen;
  775 
  776                 ip6 = mtod(m, struct ip6_hdr *);
  777                 if (m->m_len >= stripsiz + off) {
  778                         ovbcopy((caddr_t)ip6, ((caddr_t)ip6) + stripsiz, off);
  779                         m->m_data += stripsiz;
  780                         m->m_len -= stripsiz;
  781                         m->m_pkthdr.len -= stripsiz;
  782                 } else {
  783                         /*
  784                          * this comes with no copy if the boundary is on
  785                          * cluster
  786                          */
  787                         struct mbuf *n;
  788 
  789                         n = m_split(m, off, M_DONTWAIT);
  790                         if (n == NULL) {
  791                                 /* m is retained by m_split */
  792                                 goto bad;
  793                         }
  794                         m_adj(n, stripsiz);
  795                         m_cat(m, n);
  796                         /* m_cat does not update m_pkthdr.len */
  797                         m->m_pkthdr.len += n->m_pkthdr.len;
  798                 }
  799 
  800 #ifndef PULLDOWN_TEST
  801                 /*
  802                  * KAME requires that the packet to be contiguous on the
  803                  * mbuf.  We need to make that sure.
  804                  * this kind of code should be avoided.
  805                  * XXX other conditions to avoid running this part?
  806                  */
  807                 if (m->m_len != m->m_pkthdr.len) {
  808                         struct mbuf *n = NULL;
  809                         int maxlen;
  810 
  811                         MGETHDR(n, M_DONTWAIT, MT_HEADER);
  812                         maxlen = MHLEN;
  813                         if (n)
  814                                 M_MOVE_PKTHDR(n, m);
  815                         if (n && n->m_pkthdr.len > maxlen) {
  816                                 MCLGET(n, M_DONTWAIT);
  817                                 maxlen = MCLBYTES;
  818                                 if ((n->m_flags & M_EXT) == 0) {
  819                                         m_free(n);
  820                                         n = NULL;
  821                                 }
  822                         }
  823                         if (!n) {
  824                                 printf("esp6_input: mbuf allocation failed\n");
  825                                 goto bad;
  826                         }
  827 
  828                         if (n->m_pkthdr.len <= maxlen) {
  829                                 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
  830                                 n->m_len = n->m_pkthdr.len;
  831                                 n->m_next = NULL;
  832                                 m_freem(m);
  833                         } else {
  834                                 m_copydata(m, 0, maxlen, mtod(n, caddr_t));
  835                                 n->m_len = maxlen;
  836                                 n->m_next = m;
  837                                 m_adj(m, maxlen);
  838                         }
  839                         m = n;
  840                 }
  841 #endif
  842 
  843                 ip6 = mtod(m, struct ip6_hdr *);
  844                 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - stripsiz);
  845 
  846                 key_sa_recordxfer(sav, m);
  847                 if (ipsec_addhist(m, IPPROTO_ESP, spi) != 0) {
  848                         ipsec6stat.in_nomem++;
  849                         goto bad;
  850                 }
  851         }
  852 
  853         *offp = off;
  854         *mp = m;
  855 
  856         if (sav) {
  857                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  858                         printf("DP esp6_input call free SA:%p\n", sav));
  859                 key_freesav(sav);
  860         }
  861         ipsec6stat.in_success++;
  862         return nxt;
  863 
  864 bad:
  865         if (sav) {
  866                 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
  867                         printf("DP esp6_input call free SA:%p\n", sav));
  868                 key_freesav(sav);
  869         }
  870         if (m)
  871                 m_freem(m);
  872         return IPPROTO_DONE;
  873 }
  874 
  875 void
  876 esp6_ctlinput(cmd, sa, d)
  877         int cmd;
  878         struct sockaddr *sa;
  879         void *d;
  880 {
  881         const struct newesp *espp;
  882         struct newesp esp;
  883         struct ip6ctlparam *ip6cp = NULL, ip6cp1;
  884         struct secasvar *sav;
  885         struct ip6_hdr *ip6;
  886         struct mbuf *m;
  887         int off;
  888         struct sockaddr_in6 *sa6_src, *sa6_dst;
  889 
  890         if (sa->sa_family != AF_INET6 ||
  891             sa->sa_len != sizeof(struct sockaddr_in6))
  892                 return;
  893         if ((unsigned)cmd >= PRC_NCMDS)
  894                 return;
  895 
  896         /* if the parameter is from icmp6, decode it. */
  897         if (d != NULL) {
  898                 ip6cp = (struct ip6ctlparam *)d;
  899                 m = ip6cp->ip6c_m;
  900                 ip6 = ip6cp->ip6c_ip6;
  901                 off = ip6cp->ip6c_off;
  902         } else {
  903                 m = NULL;
  904                 ip6 = NULL;
  905                 off = 0;        /* calm gcc */
  906         }
  907 
  908         if (ip6) {
  909                 /*
  910                  * Notify the error to all possible sockets via pfctlinput2.
  911                  * Since the upper layer information (such as protocol type,
  912                  * source and destination ports) is embedded in the encrypted
  913                  * data and might have been cut, we can't directly call
  914                  * an upper layer ctlinput function. However, the pcbnotify
  915                  * function will consider source and destination addresses
  916                  * as well as the flow info value, and may be able to find
  917                  * some PCB that should be notified.
  918                  * Although pfctlinput2 will call esp6_ctlinput(), there is
  919                  * no possibility of an infinite loop of function calls,
  920                  * because we don't pass the inner IPv6 header.
  921                  */
  922                 bzero(&ip6cp1, sizeof(ip6cp1));
  923                 ip6cp1.ip6c_src = ip6cp->ip6c_src;
  924                 pfctlinput2(cmd, sa, (void *)&ip6cp1);
  925 
  926                 /*
  927                  * Then go to special cases that need ESP header information.
  928                  * XXX: We assume that when ip6 is non NULL,
  929                  * M and OFF are valid.
  930                  */
  931 
  932                 /* check if we can safely examine src and dst ports */
  933                 if (m->m_pkthdr.len < off + sizeof(esp))
  934                         return;
  935 
  936                 if (m->m_len < off + sizeof(esp)) {
  937                         /*
  938                          * this should be rare case,
  939                          * so we compromise on this copy...
  940                          */
  941                         m_copydata(m, off, sizeof(esp), (caddr_t)&esp);
  942                         espp = &esp;
  943                 } else
  944                         espp = (struct newesp*)(mtod(m, caddr_t) + off);
  945 
  946                 if (cmd == PRC_MSGSIZE) {
  947                         int valid = 0;
  948 
  949                         /*
  950                          * Check to see if we have a valid SA corresponding to
  951                          * the address in the ICMP message payload.
  952                          */
  953                         sa6_src = ip6cp->ip6c_src;
  954                         sa6_dst = (struct sockaddr_in6 *)sa;
  955                         sav = key_allocsa(AF_INET6,
  956                                           (caddr_t)&sa6_src->sin6_addr,
  957                                           (caddr_t)&sa6_dst->sin6_addr,
  958                                           IPPROTO_ESP, espp->esp_spi);
  959                         if (sav) {
  960                                 if (sav->state == SADB_SASTATE_MATURE ||
  961                                     sav->state == SADB_SASTATE_DYING)
  962                                         valid++;
  963                                 key_freesav(sav);
  964                         }
  965 
  966                         /* XXX Further validation? */
  967 
  968                         /*
  969                          * Depending on the value of "valid" and routing table
  970                          * size (mtudisc_{hi,lo}wat), we will:
  971                          * - recalcurate the new MTU and create the
  972                          *   corresponding routing entry, or
  973                          * - ignore the MTU change notification.
  974                          */
  975                         icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);
  976                 }
  977         } else {
  978                 /* we normally notify any pcb here */
  979         }
  980 }
  981 #endif /* INET6 */

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