The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/netipsec/ipsec_output.c

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    1 /*-
    2  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  * $FreeBSD: releng/10.0/sys/netipsec/ipsec_output.c 252028 2013-06-20 11:44:16Z ae $
   27  */
   28 
   29 /*
   30  * IPsec output processing.
   31  */
   32 #include "opt_inet.h"
   33 #include "opt_inet6.h"
   34 #include "opt_ipsec.h"
   35 #include "opt_enc.h"
   36 
   37 #include <sys/param.h>
   38 #include <sys/systm.h>
   39 #include <sys/mbuf.h>
   40 #include <sys/domain.h>
   41 #include <sys/protosw.h>
   42 #include <sys/socket.h>
   43 #include <sys/errno.h>
   44 #include <sys/syslog.h>
   45 
   46 #include <net/if.h>
   47 #include <net/pfil.h>
   48 #include <net/route.h>
   49 #include <net/vnet.h>
   50 
   51 #include <netinet/in.h>
   52 #include <netinet/in_systm.h>
   53 #include <netinet/ip.h>
   54 #include <netinet/ip_var.h>
   55 #include <netinet/in_var.h>
   56 #include <netinet/ip_ecn.h>
   57 #ifdef INET6
   58 #include <netinet6/ip6_ecn.h>
   59 #endif
   60 
   61 #include <netinet/ip6.h>
   62 #ifdef INET6
   63 #include <netinet6/ip6_var.h>
   64 #endif
   65 #include <netinet/in_pcb.h>
   66 #ifdef INET6
   67 #include <netinet/icmp6.h>
   68 #endif
   69 
   70 #include <netipsec/ipsec.h>
   71 #ifdef INET6
   72 #include <netipsec/ipsec6.h>
   73 #endif
   74 #include <netipsec/ah_var.h>
   75 #include <netipsec/esp_var.h>
   76 #include <netipsec/ipcomp_var.h>
   77 
   78 #include <netipsec/xform.h>
   79 
   80 #include <netipsec/key.h>
   81 #include <netipsec/keydb.h>
   82 #include <netipsec/key_debug.h>
   83 
   84 #include <machine/in_cksum.h>
   85 
   86 #ifdef IPSEC_NAT_T
   87 #include <netinet/udp.h>
   88 #endif
   89 
   90 #ifdef DEV_ENC
   91 #include <net/if_enc.h>
   92 #endif
   93 
   94 
   95 int
   96 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
   97 {
   98         struct tdb_ident *tdbi;
   99         struct m_tag *mtag;
  100         struct secasvar *sav;
  101         struct secasindex *saidx;
  102         int error;
  103 
  104         IPSEC_ASSERT(m != NULL, ("null mbuf"));
  105         IPSEC_ASSERT(isr != NULL, ("null ISR"));
  106         sav = isr->sav;
  107         IPSEC_ASSERT(sav != NULL, ("null SA"));
  108         IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
  109 
  110         saidx = &sav->sah->saidx;
  111         switch (saidx->dst.sa.sa_family) {
  112 #ifdef INET
  113         case AF_INET:
  114                 /* Fix the header length, for AH processing. */
  115                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
  116                 break;
  117 #endif /* INET */
  118 #ifdef INET6
  119         case AF_INET6:
  120                 /* Fix the header length, for AH processing. */
  121                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
  122                         error = ENXIO;
  123                         goto bad;
  124                 }
  125                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
  126                         /* No jumbogram support. */
  127                         error = ENXIO;  /*?*/
  128                         goto bad;
  129                 }
  130                 mtod(m, struct ip6_hdr *)->ip6_plen =
  131                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
  132                 break;
  133 #endif /* INET6 */
  134         default:
  135                 DPRINTF(("%s: unknown protocol family %u\n", __func__,
  136                     saidx->dst.sa.sa_family));
  137                 error = ENXIO;
  138                 goto bad;
  139         }
  140 
  141         /*
  142          * Add a record of what we've done or what needs to be done to the
  143          * packet.
  144          */
  145         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
  146                         sizeof(struct tdb_ident), M_NOWAIT);
  147         if (mtag == NULL) {
  148                 DPRINTF(("%s: could not get packet tag\n", __func__));
  149                 error = ENOMEM;
  150                 goto bad;
  151         }
  152 
  153         tdbi = (struct tdb_ident *)(mtag + 1);
  154         tdbi->dst = saidx->dst;
  155         tdbi->proto = saidx->proto;
  156         tdbi->spi = sav->spi;
  157         m_tag_prepend(m, mtag);
  158 
  159         /*
  160          * If there's another (bundled) SA to apply, do so.
  161          * Note that this puts a burden on the kernel stack size.
  162          * If this is a problem we'll need to introduce a queue
  163          * to set the packet on so we can unwind the stack before
  164          * doing further processing.
  165          */
  166         if (isr->next) {
  167                 IPSECSTAT_INC(ips_out_bundlesa);
  168                 /* XXX-BZ currently only support same AF bundles. */
  169                 switch (saidx->dst.sa.sa_family) {
  170 #ifdef INET
  171                 case AF_INET:
  172                         return ipsec4_process_packet(m, isr->next, 0, 0);
  173                         /* NOTREACHED */
  174 #endif
  175 #ifdef notyet
  176 #ifdef INET6
  177                 case AF_INET6:
  178                         /* XXX */
  179                         ipsec6_output_trans()
  180                         ipsec6_output_tunnel()
  181                         /* NOTREACHED */
  182 #endif /* INET6 */
  183 #endif
  184                 default:
  185                         DPRINTF(("%s: unknown protocol family %u\n", __func__,
  186                             saidx->dst.sa.sa_family));
  187                         error = ENXIO;
  188                         goto bad;
  189                 }
  190         }
  191         key_sa_recordxfer(sav, m);              /* record data transfer */
  192 
  193         /*
  194          * We're done with IPsec processing, transmit the packet using the
  195          * appropriate network protocol (IP or IPv6). SPD lookup will be
  196          * performed again there.
  197          */
  198         switch (saidx->dst.sa.sa_family) {
  199 #ifdef INET
  200         case AF_INET:
  201 #ifdef IPSEC_NAT_T
  202                 /*
  203                  * If NAT-T is enabled, now that all IPsec processing is done
  204                  * insert UDP encapsulation header after IP header.
  205                  */
  206                 if (sav->natt_type) {
  207                         struct ip *ip = mtod(m, struct ip *);
  208 #ifdef _IP_VHL
  209                         const int hlen = IP_VHL_HL(ip->ip_vhl);
  210 #else
  211                         const int hlen = (ip->ip_hl << 2);
  212 #endif
  213                         int size, off;
  214                         struct mbuf *mi;
  215                         struct udphdr *udp;
  216 
  217                         size = sizeof(struct udphdr);
  218                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
  219                                 /*
  220                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
  221                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
  222                                  * ignoring possible AH mode
  223                                  * non-IKE marker + non-ESP marker
  224                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
  225                                  */
  226                                 size += sizeof(u_int64_t);
  227                         }
  228                         mi = m_makespace(m, hlen, size, &off);
  229                         if (mi == NULL) {
  230                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
  231                                     __func__));
  232                                 error = ENOBUFS;
  233                                 goto bad;
  234                         }
  235 
  236                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
  237                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  238                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
  239                         else
  240                                 udp->uh_sport =
  241                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
  242                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
  243                         udp->uh_sum = 0;
  244                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
  245                         ip->ip_len = htons(m->m_pkthdr.len);
  246                         ip->ip_p = IPPROTO_UDP;
  247 
  248                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  249                                 *(u_int64_t *)(udp + 1) = 0;
  250                 }
  251 #endif /* IPSEC_NAT_T */
  252 
  253                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
  254 #endif /* INET */
  255 #ifdef INET6
  256         case AF_INET6:
  257                 /*
  258                  * We don't need massage, IPv6 header fields are always in
  259                  * net endian.
  260                  */
  261                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
  262 #endif /* INET6 */
  263         }
  264         panic("ipsec_process_done");
  265 bad:
  266         m_freem(m);
  267         return (error);
  268 }
  269 
  270 static struct ipsecrequest *
  271 ipsec_nextisr(
  272         struct mbuf *m,
  273         struct ipsecrequest *isr,
  274         int af,
  275         struct secasindex *saidx,
  276         int *error
  277 )
  278 {
  279 #define IPSEC_OSTAT(name)       do {            \
  280         if (isr->saidx.proto == IPPROTO_ESP)    \
  281                 ESPSTAT_INC(esps_##name);       \
  282         else if (isr->saidx.proto == IPPROTO_AH)\
  283                 AHSTAT_INC(ahs_##name);         \
  284         else                                    \
  285                 IPCOMPSTAT_INC(ipcomps_##name); \
  286 } while (0)
  287         struct secasvar *sav;
  288 
  289         IPSECREQUEST_LOCK_ASSERT(isr);
  290 
  291         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
  292                 ("invalid address family %u", af));
  293 again:
  294         /*
  295          * Craft SA index to search for proper SA.  Note that
  296          * we only fillin unspecified SA peers for transport
  297          * mode; for tunnel mode they must already be filled in.
  298          */
  299         *saidx = isr->saidx;
  300         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
  301                 /* Fillin unspecified SA peers only for transport mode */
  302                 if (af == AF_INET) {
  303                         struct sockaddr_in *sin;
  304                         struct ip *ip = mtod(m, struct ip *);
  305 
  306                         if (saidx->src.sa.sa_len == 0) {
  307                                 sin = &saidx->src.sin;
  308                                 sin->sin_len = sizeof(*sin);
  309                                 sin->sin_family = AF_INET;
  310                                 sin->sin_port = IPSEC_PORT_ANY;
  311                                 sin->sin_addr = ip->ip_src;
  312                         }
  313                         if (saidx->dst.sa.sa_len == 0) {
  314                                 sin = &saidx->dst.sin;
  315                                 sin->sin_len = sizeof(*sin);
  316                                 sin->sin_family = AF_INET;
  317                                 sin->sin_port = IPSEC_PORT_ANY;
  318                                 sin->sin_addr = ip->ip_dst;
  319                         }
  320                 } else {
  321                         struct sockaddr_in6 *sin6;
  322                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  323 
  324                         if (saidx->src.sin6.sin6_len == 0) {
  325                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
  326                                 sin6->sin6_len = sizeof(*sin6);
  327                                 sin6->sin6_family = AF_INET6;
  328                                 sin6->sin6_port = IPSEC_PORT_ANY;
  329                                 sin6->sin6_addr = ip6->ip6_src;
  330                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  331                                         /* fix scope id for comparing SPD */
  332                                         sin6->sin6_addr.s6_addr16[1] = 0;
  333                                         sin6->sin6_scope_id =
  334                                             ntohs(ip6->ip6_src.s6_addr16[1]);
  335                                 }
  336                         }
  337                         if (saidx->dst.sin6.sin6_len == 0) {
  338                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
  339                                 sin6->sin6_len = sizeof(*sin6);
  340                                 sin6->sin6_family = AF_INET6;
  341                                 sin6->sin6_port = IPSEC_PORT_ANY;
  342                                 sin6->sin6_addr = ip6->ip6_dst;
  343                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
  344                                         /* fix scope id for comparing SPD */
  345                                         sin6->sin6_addr.s6_addr16[1] = 0;
  346                                         sin6->sin6_scope_id =
  347                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
  348                                 }
  349                         }
  350                 }
  351         }
  352 
  353         /*
  354          * Lookup SA and validate it.
  355          */
  356         *error = key_checkrequest(isr, saidx);
  357         if (*error != 0) {
  358                 /*
  359                  * IPsec processing is required, but no SA found.
  360                  * I assume that key_acquire() had been called
  361                  * to get/establish the SA. Here I discard
  362                  * this packet because it is responsibility for
  363                  * upper layer to retransmit the packet.
  364                  */
  365                 IPSECSTAT_INC(ips_out_nosa);
  366                 goto bad;
  367         }
  368         sav = isr->sav;
  369         if (sav == NULL) {
  370                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
  371                         ("no SA found, but required; level %u",
  372                         ipsec_get_reqlevel(isr)));
  373                 IPSECREQUEST_UNLOCK(isr);
  374                 isr = isr->next;
  375                 /*
  376                  * If isr is NULL, we found a 'use' policy w/o SA.
  377                  * Return w/o error and w/o isr so we can drop out
  378                  * and continue w/o IPsec processing.
  379                  */
  380                 if (isr == NULL)
  381                         return isr;
  382                 IPSECREQUEST_LOCK(isr);
  383                 goto again;
  384         }
  385 
  386         /*
  387          * Check system global policy controls.
  388          */
  389         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
  390             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
  391             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
  392                 DPRINTF(("%s: IPsec outbound packet dropped due"
  393                         " to policy (check your sysctls)\n", __func__));
  394                 IPSEC_OSTAT(pdrops);
  395                 *error = EHOSTUNREACH;
  396                 goto bad;
  397         }
  398 
  399         /*
  400          * Sanity check the SA contents for the caller
  401          * before they invoke the xform output method.
  402          */
  403         if (sav->tdb_xform == NULL) {
  404                 DPRINTF(("%s: no transform for SA\n", __func__));
  405                 IPSEC_OSTAT(noxform);
  406                 *error = EHOSTUNREACH;
  407                 goto bad;
  408         }
  409         return isr;
  410 bad:
  411         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
  412         IPSECREQUEST_UNLOCK(isr);
  413         return NULL;
  414 #undef IPSEC_OSTAT
  415 }
  416 
  417 #ifdef INET
  418 /*
  419  * IPsec output logic for IPv4.
  420  */
  421 int
  422 ipsec4_process_packet(
  423         struct mbuf *m,
  424         struct ipsecrequest *isr,
  425         int flags,
  426         int tunalready)
  427 {
  428         struct secasindex saidx;
  429         struct secasvar *sav;
  430         struct ip *ip;
  431         int error, i, off;
  432 
  433         IPSEC_ASSERT(m != NULL, ("null mbuf"));
  434         IPSEC_ASSERT(isr != NULL, ("null isr"));
  435 
  436         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  437 
  438         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
  439         if (isr == NULL) {
  440                 if (error != 0)
  441                         goto bad;
  442                 return EJUSTRETURN;
  443         }
  444 
  445         sav = isr->sav;
  446 
  447 #ifdef DEV_ENC
  448         encif->if_opackets++;
  449         encif->if_obytes += m->m_pkthdr.len;
  450 
  451         /* pass the mbuf to enc0 for bpf processing */
  452         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
  453         /* pass the mbuf to enc0 for packet filtering */
  454         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  455                 goto bad;
  456 #endif
  457 
  458         if (!tunalready) {
  459                 union sockaddr_union *dst = &sav->sah->saidx.dst;
  460                 int setdf;
  461 
  462                 /*
  463                  * Collect IP_DF state from the outer header.
  464                  */
  465                 if (dst->sa.sa_family == AF_INET) {
  466                         if (m->m_len < sizeof (struct ip) &&
  467                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  468                                 error = ENOBUFS;
  469                                 goto bad;
  470                         }
  471                         ip = mtod(m, struct ip *);
  472                         /* Honor system-wide control of how to handle IP_DF */
  473                         switch (V_ip4_ipsec_dfbit) {
  474                         case 0:                 /* clear in outer header */
  475                         case 1:                 /* set in outer header */
  476                                 setdf = V_ip4_ipsec_dfbit;
  477                                 break;
  478                         default:                /* propagate to outer header */
  479                                 setdf = ntohs(ip->ip_off & IP_DF);
  480                                 break;
  481                         }
  482                 } else {
  483                         ip = NULL;              /* keep compiler happy */
  484                         setdf = 0;
  485                 }
  486                 /* Do the appropriate encapsulation, if necessary */
  487                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
  488                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
  489 #if 0
  490                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
  491                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
  492 #endif
  493                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
  494                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
  495                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
  496                         struct mbuf *mp;
  497 
  498                         /* Fix IPv4 header checksum and length */
  499                         if (m->m_len < sizeof (struct ip) &&
  500                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  501                                 error = ENOBUFS;
  502                                 goto bad;
  503                         }
  504                         ip = mtod(m, struct ip *);
  505                         ip->ip_len = htons(m->m_pkthdr.len);
  506                         ip->ip_sum = 0;
  507 #ifdef _IP_VHL
  508                         if (ip->ip_vhl == IP_VHL_BORING)
  509                                 ip->ip_sum = in_cksum_hdr(ip);
  510                         else
  511                                 ip->ip_sum = in_cksum(m,
  512                                         _IP_VHL_HL(ip->ip_vhl) << 2);
  513 #else
  514                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
  515 #endif
  516 
  517                         /* Encapsulate the packet */
  518                         error = ipip_output(m, isr, &mp, 0, 0);
  519                         if (mp == NULL && !error) {
  520                                 /* Should never happen. */
  521                                 DPRINTF(("%s: ipip_output returns no mbuf and "
  522                                         "no error!", __func__));
  523                                 error = EFAULT;
  524                         }
  525                         if (error) {
  526                                 if (mp) {
  527                                         /* XXX: Should never happen! */
  528                                         m_freem(mp);
  529                                 }
  530                                 m = NULL; /* ipip_output() already freed it */
  531                                 goto bad;
  532                         }
  533                         m = mp, mp = NULL;
  534                         /*
  535                          * ipip_output clears IP_DF in the new header.  If
  536                          * we need to propagate IP_DF from the outer header,
  537                          * then we have to do it here.
  538                          *
  539                          * XXX shouldn't assume what ipip_output does.
  540                          */
  541                         if (dst->sa.sa_family == AF_INET && setdf) {
  542                                 if (m->m_len < sizeof (struct ip) &&
  543                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  544                                         error = ENOBUFS;
  545                                         goto bad;
  546                                 }
  547                                 ip = mtod(m, struct ip *);
  548                                 ip->ip_off = ntohs(ip->ip_off);
  549                                 ip->ip_off |= IP_DF;
  550                                 ip->ip_off = htons(ip->ip_off);
  551                         }
  552                 }
  553         }
  554 
  555 #ifdef DEV_ENC
  556         /* pass the mbuf to enc0 for bpf processing */
  557         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
  558         /* pass the mbuf to enc0 for packet filtering */
  559         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  560                 goto bad;
  561 #endif
  562 
  563         /*
  564          * Dispatch to the appropriate IPsec transform logic.  The
  565          * packet will be returned for transmission after crypto
  566          * processing, etc. are completed.  For encapsulation we
  567          * bypass this call because of the explicit call done above
  568          * (necessary to deal with IP_DF handling for IPv4).
  569          *
  570          * NB: m & sav are ``passed to caller'' who's reponsible for
  571          *     for reclaiming their resources.
  572          */
  573         if (sav->tdb_xform->xf_type != XF_IP4) {
  574                 ip = mtod(m, struct ip *);
  575                 i = ip->ip_hl << 2;
  576                 off = offsetof(struct ip, ip_p);
  577                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
  578         } else {
  579                 error = ipsec_process_done(m, isr);
  580         }
  581         IPSECREQUEST_UNLOCK(isr);
  582         return error;
  583 bad:
  584         if (isr)
  585                 IPSECREQUEST_UNLOCK(isr);
  586         if (m)
  587                 m_freem(m);
  588         return error;
  589 }
  590 #endif
  591 
  592 #ifdef INET6
  593 /*
  594  * Chop IP6 header from the payload.
  595  */
  596 static struct mbuf *
  597 ipsec6_splithdr(struct mbuf *m)
  598 {
  599         struct mbuf *mh;
  600         struct ip6_hdr *ip6;
  601         int hlen;
  602 
  603         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
  604                 ("first mbuf too short, len %u", m->m_len));
  605         ip6 = mtod(m, struct ip6_hdr *);
  606         hlen = sizeof(struct ip6_hdr);
  607         if (m->m_len > hlen) {
  608                 MGETHDR(mh, M_NOWAIT, MT_DATA);
  609                 if (!mh) {
  610                         m_freem(m);
  611                         return NULL;
  612                 }
  613                 M_MOVE_PKTHDR(mh, m);
  614                 MH_ALIGN(mh, hlen);
  615                 m->m_len -= hlen;
  616                 m->m_data += hlen;
  617                 mh->m_next = m;
  618                 m = mh;
  619                 m->m_len = hlen;
  620                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
  621         } else if (m->m_len < hlen) {
  622                 m = m_pullup(m, hlen);
  623                 if (!m)
  624                         return NULL;
  625         }
  626         return m;
  627 }
  628 
  629 /*
  630  * IPsec output logic for IPv6, transport mode.
  631  */
  632 int
  633 ipsec6_output_trans(
  634         struct ipsec_output_state *state,
  635         u_char *nexthdrp,
  636         struct mbuf *mprev,
  637         struct secpolicy *sp,
  638         int flags,
  639         int *tun)
  640 {
  641         struct ipsecrequest *isr;
  642         struct secasindex saidx;
  643         int error = 0;
  644         struct mbuf *m;
  645 
  646         IPSEC_ASSERT(state != NULL, ("null state"));
  647         IPSEC_ASSERT(state->m != NULL, ("null m"));
  648         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
  649         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
  650         IPSEC_ASSERT(sp != NULL, ("null sp"));
  651         IPSEC_ASSERT(tun != NULL, ("null tun"));
  652 
  653         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  654                 printf("%s: applied SP\n", __func__);
  655                 kdebug_secpolicy(sp));
  656 
  657         isr = sp->req;
  658         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  659                 /* the rest will be handled by ipsec6_output_tunnel() */
  660                 *tun = 1;               /* need tunnel-mode processing */
  661                 return 0;
  662         }
  663 
  664         *tun = 0;
  665         m = state->m;
  666 
  667         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  668         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  669         if (isr == NULL) {
  670                 if (error != 0) {
  671 #ifdef notdef
  672                         /* XXX should notification be done for all errors ? */
  673                         /*
  674                          * Notify the fact that the packet is discarded
  675                          * to ourselves. I believe this is better than
  676                          * just silently discarding. (jinmei@kame.net)
  677                          * XXX: should we restrict the error to TCP packets?
  678                          * XXX: should we directly notify sockets via
  679                          *      pfctlinputs?
  680                          */
  681                         icmp6_error(m, ICMP6_DST_UNREACH,
  682                                     ICMP6_DST_UNREACH_ADMIN, 0);
  683                         m = NULL;       /* NB: icmp6_error frees mbuf */
  684 #endif
  685                         goto bad;
  686                 }
  687                 return EJUSTRETURN;
  688         }
  689 
  690         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  691                                                   sizeof (struct ip6_hdr),
  692                                                   offsetof(struct ip6_hdr, 
  693                                                            ip6_nxt));
  694         IPSECREQUEST_UNLOCK(isr);
  695         return error;
  696 bad:
  697         if (isr)
  698                 IPSECREQUEST_UNLOCK(isr);
  699         if (m)
  700                 m_freem(m);
  701         state->m = NULL;
  702         return error;
  703 }
  704 
  705 static int
  706 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
  707 {
  708         struct ip6_hdr *oip6;
  709         struct ip6_hdr *ip6;
  710         size_t plen;
  711 
  712         /* can't tunnel between different AFs */
  713         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
  714             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
  715                 m_freem(m);
  716                 return EINVAL;
  717         }
  718         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
  719                 ("mbuf wrong size; len %u", m->m_len));
  720 
  721 
  722         /*
  723          * grow the mbuf to accomodate the new IPv6 header.
  724          */
  725         plen = m->m_pkthdr.len;
  726         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
  727                 struct mbuf *n;
  728                 MGET(n, M_NOWAIT, MT_DATA);
  729                 if (!n) {
  730                         m_freem(m);
  731                         return ENOBUFS;
  732                 }
  733                 n->m_len = sizeof(struct ip6_hdr);
  734                 n->m_next = m->m_next;
  735                 m->m_next = n;
  736                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  737                 oip6 = mtod(n, struct ip6_hdr *);
  738         } else {
  739                 m->m_next->m_len += sizeof(struct ip6_hdr);
  740                 m->m_next->m_data -= sizeof(struct ip6_hdr);
  741                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  742                 oip6 = mtod(m->m_next, struct ip6_hdr *);
  743         }
  744         ip6 = mtod(m, struct ip6_hdr *);
  745         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
  746 
  747         /* Fake link-local scope-class addresses */
  748         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
  749                 oip6->ip6_src.s6_addr16[1] = 0;
  750         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
  751                 oip6->ip6_dst.s6_addr16[1] = 0;
  752 
  753         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
  754         /* ECN consideration. */
  755         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
  756         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
  757                 ip6->ip6_plen = htons(plen);
  758         else {
  759                 /* ip6->ip6_plen will be updated in ip6_output() */
  760         }
  761         ip6->ip6_nxt = IPPROTO_IPV6;
  762         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
  763         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
  764         ip6->ip6_hlim = IPV6_DEFHLIM;
  765 
  766         /* XXX Should ip6_src be updated later ? */
  767 
  768         return 0;
  769 }
  770 
  771 /*
  772  * IPsec output logic for IPv6, tunnel mode.
  773  */
  774 int
  775 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
  776 {
  777         struct ip6_hdr *ip6;
  778         struct ipsecrequest *isr;
  779         struct secasindex saidx;
  780         int error;
  781         struct sockaddr_in6 *dst6;
  782         struct mbuf *m;
  783 
  784         IPSEC_ASSERT(state != NULL, ("null state"));
  785         IPSEC_ASSERT(state->m != NULL, ("null m"));
  786         IPSEC_ASSERT(sp != NULL, ("null sp"));
  787 
  788         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  789                 printf("%s: applied SP\n", __func__);
  790                 kdebug_secpolicy(sp));
  791 
  792         m = state->m;
  793         /*
  794          * transport mode ipsec (before the 1st tunnel mode) is already
  795          * processed by ipsec6_output_trans().
  796          */
  797         for (isr = sp->req; isr; isr = isr->next) {
  798                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
  799                         break;
  800         }
  801 
  802         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  803         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  804         if (isr == NULL) {
  805                 if (error != 0)
  806                         goto bad;
  807                 return EJUSTRETURN; 
  808         }
  809 
  810 #ifdef DEV_ENC
  811         encif->if_opackets++;
  812         encif->if_obytes += m->m_pkthdr.len;
  813 
  814         /* pass the mbuf to enc0 for bpf processing */
  815         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
  816         /* pass the mbuf to enc0 for packet filtering */
  817         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  818                 goto bad;
  819 #endif
  820 
  821         /*
  822          * There may be the case that SA status will be changed when
  823          * we are refering to one. So calling splsoftnet().
  824          */
  825         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  826                 /*
  827                  * build IPsec tunnel.
  828                  */
  829                 /* XXX should be processed with other familiy */
  830                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
  831                         ipseclog((LOG_ERR, "%s: family mismatched between "
  832                             "inner and outer, spi=%u\n", __func__,
  833                             ntohl(isr->sav->spi)));
  834                         IPSEC6STAT_INC(ips_out_inval);
  835                         error = EAFNOSUPPORT;
  836                         goto bad;
  837                 }
  838 
  839                 m = ipsec6_splithdr(m);
  840                 if (!m) {
  841                         IPSEC6STAT_INC(ips_out_nomem);
  842                         error = ENOMEM;
  843                         goto bad;
  844                 }
  845                 error = ipsec6_encapsulate(m, isr->sav);
  846                 if (error) {
  847                         m = NULL;
  848                         goto bad;
  849                 }
  850                 ip6 = mtod(m, struct ip6_hdr *);
  851 
  852                 state->ro =
  853                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
  854                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
  855                 dst6 = (struct sockaddr_in6 *)state->dst;
  856                 if (state->ro->ro_rt
  857                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
  858                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
  859                         RTFREE(state->ro->ro_rt);
  860                         state->ro->ro_rt = NULL;
  861                 }
  862                 if (state->ro->ro_rt == NULL) {
  863                         bzero(dst6, sizeof(*dst6));
  864                         dst6->sin6_family = AF_INET6;
  865                         dst6->sin6_len = sizeof(*dst6);
  866                         dst6->sin6_addr = ip6->ip6_dst;
  867                         rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
  868                 }
  869                 if (state->ro->ro_rt == NULL) {
  870                         IP6STAT_INC(ip6s_noroute);
  871                         IPSEC6STAT_INC(ips_out_noroute);
  872                         error = EHOSTUNREACH;
  873                         goto bad;
  874                 }
  875 
  876                 /* adjust state->dst if tunnel endpoint is offlink */
  877                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
  878                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
  879         }
  880 
  881         m = ipsec6_splithdr(m);
  882         if (!m) {
  883                 IPSEC6STAT_INC(ips_out_nomem);
  884                 error = ENOMEM;
  885                 goto bad;
  886         }
  887         ip6 = mtod(m, struct ip6_hdr *);
  888 
  889 #ifdef DEV_ENC
  890         /* pass the mbuf to enc0 for bpf processing */
  891         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
  892         /* pass the mbuf to enc0 for packet filtering */
  893         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  894                 goto bad;
  895 #endif
  896 
  897         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  898                 sizeof (struct ip6_hdr),
  899                 offsetof(struct ip6_hdr, ip6_nxt));
  900         IPSECREQUEST_UNLOCK(isr);
  901         return error;
  902 bad:
  903         if (isr)
  904                 IPSECREQUEST_UNLOCK(isr);
  905         if (m)
  906                 m_freem(m);
  907         state->m = NULL;
  908         return error;
  909 }
  910 #endif /*INET6*/

Cache object: d007490fdf145d28c8a5395113d5b147


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