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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    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  * $FreeBSD$
   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         m_addr_changed(m);
  194 
  195         /*
  196          * We're done with IPsec processing, transmit the packet using the
  197          * appropriate network protocol (IP or IPv6). SPD lookup will be
  198          * performed again there.
  199          */
  200         switch (saidx->dst.sa.sa_family) {
  201 #ifdef INET
  202         struct ip *ip;
  203         case AF_INET:
  204                 ip = mtod(m, struct ip *);
  205                 ip->ip_len = ntohs(ip->ip_len);
  206                 ip->ip_off = ntohs(ip->ip_off);
  207 
  208 #ifdef IPSEC_NAT_T
  209                 /*
  210                  * If NAT-T is enabled, now that all IPsec processing is done
  211                  * insert UDP encapsulation header after IP header.
  212                  */
  213                 if (sav->natt_type) {
  214                         const int hlen = (ip->ip_hl << 2);
  215                         int size, off;
  216                         struct mbuf *mi;
  217                         struct udphdr *udp;
  218 
  219                         size = sizeof(struct udphdr);
  220                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
  221                                 /*
  222                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
  223                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
  224                                  * ignoring possible AH mode
  225                                  * non-IKE marker + non-ESP marker
  226                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
  227                                  */
  228                                 size += sizeof(u_int64_t);
  229                         }
  230                         mi = m_makespace(m, hlen, size, &off);
  231                         if (mi == NULL) {
  232                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
  233                                     __func__));
  234                                 error = ENOBUFS;
  235                                 goto bad;
  236                         }
  237 
  238                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
  239                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  240                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
  241                         else
  242                                 udp->uh_sport =
  243                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
  244                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
  245                         udp->uh_sum = 0;
  246                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
  247                         ip->ip_len = m->m_pkthdr.len;
  248                         ip->ip_p = IPPROTO_UDP;
  249 
  250                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  251                                 *(u_int64_t *)(udp + 1) = 0;
  252                 }
  253 #endif /* IPSEC_NAT_T */
  254 
  255                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
  256 #endif /* INET */
  257 #ifdef INET6
  258         case AF_INET6:
  259                 /*
  260                  * We don't need massage, IPv6 header fields are always in
  261                  * net endian.
  262                  */
  263                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
  264 #endif /* INET6 */
  265         }
  266         panic("ipsec_process_done");
  267 bad:
  268         m_freem(m);
  269         return (error);
  270 }
  271 
  272 static struct ipsecrequest *
  273 ipsec_nextisr(
  274         struct mbuf *m,
  275         struct ipsecrequest *isr,
  276         int af,
  277         struct secasindex *saidx,
  278         int *error
  279 )
  280 {
  281 #define IPSEC_OSTAT(name)       do {            \
  282         if (isr->saidx.proto == IPPROTO_ESP)    \
  283                 ESPSTAT_INC(esps_##name);       \
  284         else if (isr->saidx.proto == IPPROTO_AH)\
  285                 AHSTAT_INC(ahs_##name);         \
  286         else                                    \
  287                 IPCOMPSTAT_INC(ipcomps_##name); \
  288 } while (0)
  289         struct secasvar *sav;
  290 
  291         IPSECREQUEST_LOCK_ASSERT(isr);
  292 
  293         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
  294                 ("invalid address family %u", af));
  295 again:
  296         /*
  297          * Craft SA index to search for proper SA.  Note that
  298          * we only fillin unspecified SA peers for transport
  299          * mode; for tunnel mode they must already be filled in.
  300          */
  301         *saidx = isr->saidx;
  302         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
  303                 /* Fillin unspecified SA peers only for transport mode */
  304                 if (af == AF_INET) {
  305                         struct sockaddr_in *sin;
  306                         struct ip *ip = mtod(m, struct ip *);
  307 
  308                         if (saidx->src.sa.sa_len == 0) {
  309                                 sin = &saidx->src.sin;
  310                                 sin->sin_len = sizeof(*sin);
  311                                 sin->sin_family = AF_INET;
  312                                 sin->sin_port = IPSEC_PORT_ANY;
  313                                 sin->sin_addr = ip->ip_src;
  314                         }
  315                         if (saidx->dst.sa.sa_len == 0) {
  316                                 sin = &saidx->dst.sin;
  317                                 sin->sin_len = sizeof(*sin);
  318                                 sin->sin_family = AF_INET;
  319                                 sin->sin_port = IPSEC_PORT_ANY;
  320                                 sin->sin_addr = ip->ip_dst;
  321                         }
  322                 } else {
  323                         struct sockaddr_in6 *sin6;
  324                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  325 
  326                         if (saidx->src.sin6.sin6_len == 0) {
  327                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
  328                                 sin6->sin6_len = sizeof(*sin6);
  329                                 sin6->sin6_family = AF_INET6;
  330                                 sin6->sin6_port = IPSEC_PORT_ANY;
  331                                 sin6->sin6_addr = ip6->ip6_src;
  332                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  333                                         /* fix scope id for comparing SPD */
  334                                         sin6->sin6_addr.s6_addr16[1] = 0;
  335                                         sin6->sin6_scope_id =
  336                                             ntohs(ip6->ip6_src.s6_addr16[1]);
  337                                 }
  338                         }
  339                         if (saidx->dst.sin6.sin6_len == 0) {
  340                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
  341                                 sin6->sin6_len = sizeof(*sin6);
  342                                 sin6->sin6_family = AF_INET6;
  343                                 sin6->sin6_port = IPSEC_PORT_ANY;
  344                                 sin6->sin6_addr = ip6->ip6_dst;
  345                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
  346                                         /* fix scope id for comparing SPD */
  347                                         sin6->sin6_addr.s6_addr16[1] = 0;
  348                                         sin6->sin6_scope_id =
  349                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
  350                                 }
  351                         }
  352                 }
  353         }
  354 
  355         /*
  356          * Lookup SA and validate it.
  357          */
  358         *error = key_checkrequest(isr, saidx);
  359         if (*error != 0) {
  360                 /*
  361                  * IPsec processing is required, but no SA found.
  362                  * I assume that key_acquire() had been called
  363                  * to get/establish the SA. Here I discard
  364                  * this packet because it is responsibility for
  365                  * upper layer to retransmit the packet.
  366                  */
  367                 IPSECSTAT_INC(ips_out_nosa);
  368                 goto bad;
  369         }
  370         sav = isr->sav;
  371         if (sav == NULL) {
  372                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
  373                         ("no SA found, but required; level %u",
  374                         ipsec_get_reqlevel(isr)));
  375                 IPSECREQUEST_UNLOCK(isr);
  376                 isr = isr->next;
  377                 /*
  378                  * If isr is NULL, we found a 'use' policy w/o SA.
  379                  * Return w/o error and w/o isr so we can drop out
  380                  * and continue w/o IPsec processing.
  381                  */
  382                 if (isr == NULL)
  383                         return isr;
  384                 IPSECREQUEST_LOCK(isr);
  385                 goto again;
  386         }
  387 
  388         /*
  389          * Check system global policy controls.
  390          */
  391         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
  392             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
  393             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
  394                 DPRINTF(("%s: IPsec outbound packet dropped due"
  395                         " to policy (check your sysctls)\n", __func__));
  396                 IPSEC_OSTAT(pdrops);
  397                 *error = EHOSTUNREACH;
  398                 goto bad;
  399         }
  400 
  401         /*
  402          * Sanity check the SA contents for the caller
  403          * before they invoke the xform output method.
  404          */
  405         if (sav->tdb_xform == NULL) {
  406                 DPRINTF(("%s: no transform for SA\n", __func__));
  407                 IPSEC_OSTAT(noxform);
  408                 *error = EHOSTUNREACH;
  409                 goto bad;
  410         }
  411         return isr;
  412 bad:
  413         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
  414         IPSECREQUEST_UNLOCK(isr);
  415         return NULL;
  416 #undef IPSEC_OSTAT
  417 }
  418 
  419 #ifdef INET
  420 /*
  421  * IPsec output logic for IPv4.
  422  */
  423 int
  424 ipsec4_process_packet(
  425         struct mbuf *m,
  426         struct ipsecrequest *isr,
  427         int flags,
  428         int tunalready)
  429 {
  430         struct secasindex saidx;
  431         struct secasvar *sav;
  432         struct ip *ip;
  433         int error, i, off;
  434 
  435         IPSEC_ASSERT(m != NULL, ("null mbuf"));
  436         IPSEC_ASSERT(isr != NULL, ("null isr"));
  437 
  438         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  439 
  440         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
  441         if (isr == NULL) {
  442                 if (error != 0)
  443                         goto bad;
  444                 return EJUSTRETURN;
  445         }
  446 
  447         sav = isr->sav;
  448 
  449 #ifdef DEV_ENC
  450         encif->if_opackets++;
  451         encif->if_obytes += m->m_pkthdr.len;
  452 
  453         /* pass the mbuf to enc0 for bpf processing */
  454         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
  455         /* pass the mbuf to enc0 for packet filtering */
  456         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  457                 goto bad;
  458 #endif
  459 
  460         if (!tunalready) {
  461                 union sockaddr_union *dst = &sav->sah->saidx.dst;
  462                 int setdf;
  463 
  464                 /*
  465                  * Collect IP_DF state from the outer header.
  466                  */
  467                 if (dst->sa.sa_family == AF_INET) {
  468                         if (m->m_len < sizeof (struct ip) &&
  469                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  470                                 error = ENOBUFS;
  471                                 goto bad;
  472                         }
  473                         ip = mtod(m, struct ip *);
  474                         /* Honor system-wide control of how to handle IP_DF */
  475                         switch (V_ip4_ipsec_dfbit) {
  476                         case 0:                 /* clear in outer header */
  477                         case 1:                 /* set in outer header */
  478                                 setdf = V_ip4_ipsec_dfbit;
  479                                 break;
  480                         default:                /* propagate to outer header */
  481                                 setdf = ntohs(ip->ip_off & IP_DF);
  482                                 break;
  483                         }
  484                 } else {
  485                         ip = NULL;              /* keep compiler happy */
  486                         setdf = 0;
  487                 }
  488                 /* Do the appropriate encapsulation, if necessary */
  489                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
  490                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
  491 #if 0
  492                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
  493                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
  494 #endif
  495                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
  496                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
  497                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
  498                         struct mbuf *mp;
  499 
  500                         /* Fix IPv4 header checksum and length */
  501                         if (m->m_len < sizeof (struct ip) &&
  502                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  503                                 error = ENOBUFS;
  504                                 goto bad;
  505                         }
  506                         ip = mtod(m, struct ip *);
  507                         ip->ip_len = htons(m->m_pkthdr.len);
  508                         ip->ip_sum = 0;
  509                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
  510 
  511                         /* Encapsulate the packet */
  512                         error = ipip_output(m, isr, &mp, 0, 0);
  513                         if (mp == NULL && !error) {
  514                                 /* Should never happen. */
  515                                 DPRINTF(("%s: ipip_output returns no mbuf and "
  516                                         "no error!", __func__));
  517                                 error = EFAULT;
  518                         }
  519                         if (error) {
  520                                 if (mp) {
  521                                         /* XXX: Should never happen! */
  522                                         m_freem(mp);
  523                                 }
  524                                 m = NULL; /* ipip_output() already freed it */
  525                                 goto bad;
  526                         }
  527                         m = mp, mp = NULL;
  528                         /*
  529                          * ipip_output clears IP_DF in the new header.  If
  530                          * we need to propagate IP_DF from the outer header,
  531                          * then we have to do it here.
  532                          *
  533                          * XXX shouldn't assume what ipip_output does.
  534                          */
  535                         if (dst->sa.sa_family == AF_INET && setdf) {
  536                                 if (m->m_len < sizeof (struct ip) &&
  537                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  538                                         error = ENOBUFS;
  539                                         goto bad;
  540                                 }
  541                                 ip = mtod(m, struct ip *);
  542                                 ip->ip_off = ntohs(ip->ip_off);
  543                                 ip->ip_off |= IP_DF;
  544                                 ip->ip_off = htons(ip->ip_off);
  545                         }
  546                 }
  547         }
  548 
  549 #ifdef DEV_ENC
  550         /* pass the mbuf to enc0 for bpf processing */
  551         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
  552         /* pass the mbuf to enc0 for packet filtering */
  553         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  554                 goto bad;
  555 #endif
  556 
  557         /*
  558          * Dispatch to the appropriate IPsec transform logic.  The
  559          * packet will be returned for transmission after crypto
  560          * processing, etc. are completed.  For encapsulation we
  561          * bypass this call because of the explicit call done above
  562          * (necessary to deal with IP_DF handling for IPv4).
  563          *
  564          * NB: m & sav are ``passed to caller'' who's reponsible for
  565          *     for reclaiming their resources.
  566          */
  567         if (sav->tdb_xform->xf_type != XF_IP4) {
  568                 ip = mtod(m, struct ip *);
  569                 i = ip->ip_hl << 2;
  570                 off = offsetof(struct ip, ip_p);
  571                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
  572         } else {
  573                 error = ipsec_process_done(m, isr);
  574         }
  575         IPSECREQUEST_UNLOCK(isr);
  576         return error;
  577 bad:
  578         if (isr)
  579                 IPSECREQUEST_UNLOCK(isr);
  580         if (m)
  581                 m_freem(m);
  582         return error;
  583 }
  584 #endif
  585 
  586 #ifdef INET6
  587 /*
  588  * Chop IP6 header from the payload.
  589  */
  590 static struct mbuf *
  591 ipsec6_splithdr(struct mbuf *m)
  592 {
  593         struct mbuf *mh;
  594         struct ip6_hdr *ip6;
  595         int hlen;
  596 
  597         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
  598                 ("first mbuf too short, len %u", m->m_len));
  599         ip6 = mtod(m, struct ip6_hdr *);
  600         hlen = sizeof(struct ip6_hdr);
  601         if (m->m_len > hlen) {
  602                 MGETHDR(mh, M_DONTWAIT, MT_DATA);
  603                 if (!mh) {
  604                         m_freem(m);
  605                         return NULL;
  606                 }
  607                 M_MOVE_PKTHDR(mh, m);
  608                 MH_ALIGN(mh, hlen);
  609                 m->m_len -= hlen;
  610                 m->m_data += hlen;
  611                 mh->m_next = m;
  612                 m = mh;
  613                 m->m_len = hlen;
  614                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
  615         } else if (m->m_len < hlen) {
  616                 m = m_pullup(m, hlen);
  617                 if (!m)
  618                         return NULL;
  619         }
  620         return m;
  621 }
  622 
  623 /*
  624  * IPsec output logic for IPv6, transport mode.
  625  */
  626 int
  627 ipsec6_output_trans(
  628         struct ipsec_output_state *state,
  629         u_char *nexthdrp,
  630         struct mbuf *mprev,
  631         struct secpolicy *sp,
  632         int flags,
  633         int *tun)
  634 {
  635         struct ipsecrequest *isr;
  636         struct secasindex saidx;
  637         int error = 0;
  638         struct mbuf *m;
  639 
  640         IPSEC_ASSERT(state != NULL, ("null state"));
  641         IPSEC_ASSERT(state->m != NULL, ("null m"));
  642         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
  643         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
  644         IPSEC_ASSERT(sp != NULL, ("null sp"));
  645         IPSEC_ASSERT(tun != NULL, ("null tun"));
  646 
  647         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  648                 printf("%s: applied SP\n", __func__);
  649                 kdebug_secpolicy(sp));
  650 
  651         isr = sp->req;
  652         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  653                 /* the rest will be handled by ipsec6_output_tunnel() */
  654                 *tun = 1;               /* need tunnel-mode processing */
  655                 return 0;
  656         }
  657 
  658         *tun = 0;
  659         m = state->m;
  660 
  661         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  662         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  663         if (isr == NULL) {
  664                 if (error != 0) {
  665 #ifdef notdef
  666                         /* XXX should notification be done for all errors ? */
  667                         /*
  668                          * Notify the fact that the packet is discarded
  669                          * to ourselves. I believe this is better than
  670                          * just silently discarding. (jinmei@kame.net)
  671                          * XXX: should we restrict the error to TCP packets?
  672                          * XXX: should we directly notify sockets via
  673                          *      pfctlinputs?
  674                          */
  675                         icmp6_error(m, ICMP6_DST_UNREACH,
  676                                     ICMP6_DST_UNREACH_ADMIN, 0);
  677                         m = NULL;       /* NB: icmp6_error frees mbuf */
  678 #endif
  679                         goto bad;
  680                 }
  681                 return EJUSTRETURN;
  682         }
  683 
  684         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  685                                                   sizeof (struct ip6_hdr),
  686                                                   offsetof(struct ip6_hdr, 
  687                                                            ip6_nxt));
  688         IPSECREQUEST_UNLOCK(isr);
  689         return error;
  690 bad:
  691         if (isr)
  692                 IPSECREQUEST_UNLOCK(isr);
  693         if (m)
  694                 m_freem(m);
  695         state->m = NULL;
  696         return error;
  697 }
  698 
  699 static int
  700 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
  701 {
  702         struct ip6_hdr *oip6;
  703         struct ip6_hdr *ip6;
  704         size_t plen;
  705 
  706         /* can't tunnel between different AFs */
  707         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
  708             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
  709                 m_freem(m);
  710                 return EINVAL;
  711         }
  712         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
  713                 ("mbuf wrong size; len %u", m->m_len));
  714 
  715 
  716         /*
  717          * grow the mbuf to accomodate the new IPv6 header.
  718          */
  719         plen = m->m_pkthdr.len;
  720         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
  721                 struct mbuf *n;
  722                 MGET(n, M_DONTWAIT, MT_DATA);
  723                 if (!n) {
  724                         m_freem(m);
  725                         return ENOBUFS;
  726                 }
  727                 n->m_len = sizeof(struct ip6_hdr);
  728                 n->m_next = m->m_next;
  729                 m->m_next = n;
  730                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  731                 oip6 = mtod(n, struct ip6_hdr *);
  732         } else {
  733                 m->m_next->m_len += sizeof(struct ip6_hdr);
  734                 m->m_next->m_data -= sizeof(struct ip6_hdr);
  735                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  736                 oip6 = mtod(m->m_next, struct ip6_hdr *);
  737         }
  738         ip6 = mtod(m, struct ip6_hdr *);
  739         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
  740 
  741         /* Fake link-local scope-class addresses */
  742         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
  743                 oip6->ip6_src.s6_addr16[1] = 0;
  744         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
  745                 oip6->ip6_dst.s6_addr16[1] = 0;
  746 
  747         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
  748         /* ECN consideration. */
  749         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
  750         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
  751                 ip6->ip6_plen = htons(plen);
  752         else {
  753                 /* ip6->ip6_plen will be updated in ip6_output() */
  754         }
  755         ip6->ip6_nxt = IPPROTO_IPV6;
  756         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
  757         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
  758         ip6->ip6_hlim = IPV6_DEFHLIM;
  759 
  760         /* XXX Should ip6_src be updated later ? */
  761 
  762         return 0;
  763 }
  764 
  765 /*
  766  * IPsec output logic for IPv6, tunnel mode.
  767  */
  768 int
  769 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
  770 {
  771         struct ip6_hdr *ip6;
  772         struct ipsecrequest *isr;
  773         struct secasindex saidx;
  774         int error;
  775         struct sockaddr_in6 *dst6;
  776         struct mbuf *m;
  777 
  778         IPSEC_ASSERT(state != NULL, ("null state"));
  779         IPSEC_ASSERT(state->m != NULL, ("null m"));
  780         IPSEC_ASSERT(sp != NULL, ("null sp"));
  781 
  782         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  783                 printf("%s: applied SP\n", __func__);
  784                 kdebug_secpolicy(sp));
  785 
  786         m = state->m;
  787         /*
  788          * transport mode ipsec (before the 1st tunnel mode) is already
  789          * processed by ipsec6_output_trans().
  790          */
  791         for (isr = sp->req; isr; isr = isr->next) {
  792                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
  793                         break;
  794         }
  795 
  796         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  797         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  798         if (isr == NULL) {
  799                 if (error != 0)
  800                         goto bad;
  801                 return EJUSTRETURN; 
  802         }
  803 
  804 #ifdef DEV_ENC
  805         encif->if_opackets++;
  806         encif->if_obytes += m->m_pkthdr.len;
  807 
  808         /* pass the mbuf to enc0 for bpf processing */
  809         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
  810         /* pass the mbuf to enc0 for packet filtering */
  811         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  812                 goto bad;
  813 #endif
  814 
  815         /*
  816          * There may be the case that SA status will be changed when
  817          * we are refering to one. So calling splsoftnet().
  818          */
  819         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  820                 /*
  821                  * build IPsec tunnel.
  822                  */
  823                 /* XXX should be processed with other familiy */
  824                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
  825                         ipseclog((LOG_ERR, "%s: family mismatched between "
  826                             "inner and outer, spi=%u\n", __func__,
  827                             ntohl(isr->sav->spi)));
  828                         IPSEC6STAT_INC(ips_out_inval);
  829                         error = EAFNOSUPPORT;
  830                         goto bad;
  831                 }
  832 
  833                 m = ipsec6_splithdr(m);
  834                 if (!m) {
  835                         IPSEC6STAT_INC(ips_out_nomem);
  836                         error = ENOMEM;
  837                         goto bad;
  838                 }
  839                 error = ipsec6_encapsulate(m, isr->sav);
  840                 if (error) {
  841                         m = NULL;
  842                         goto bad;
  843                 }
  844                 ip6 = mtod(m, struct ip6_hdr *);
  845 
  846                 state->ro =
  847                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
  848                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
  849                 dst6 = (struct sockaddr_in6 *)state->dst;
  850                 if (state->ro->ro_rt
  851                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
  852                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
  853                         RTFREE(state->ro->ro_rt);
  854                         state->ro->ro_rt = NULL;
  855                 }
  856                 if (state->ro->ro_rt == NULL) {
  857                         bzero(dst6, sizeof(*dst6));
  858                         dst6->sin6_family = AF_INET6;
  859                         dst6->sin6_len = sizeof(*dst6);
  860                         dst6->sin6_addr = ip6->ip6_dst;
  861                         rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
  862                 }
  863                 if (state->ro->ro_rt == NULL) {
  864                         IP6STAT_INC(ip6s_noroute);
  865                         IPSEC6STAT_INC(ips_out_noroute);
  866                         error = EHOSTUNREACH;
  867                         goto bad;
  868                 }
  869 
  870                 /* adjust state->dst if tunnel endpoint is offlink */
  871                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
  872                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
  873         }
  874 
  875         m = ipsec6_splithdr(m);
  876         if (!m) {
  877                 IPSEC6STAT_INC(ips_out_nomem);
  878                 error = ENOMEM;
  879                 goto bad;
  880         }
  881         ip6 = mtod(m, struct ip6_hdr *);
  882 
  883 #ifdef DEV_ENC
  884         /* pass the mbuf to enc0 for bpf processing */
  885         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
  886         /* pass the mbuf to enc0 for packet filtering */
  887         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  888                 goto bad;
  889 #endif
  890 
  891         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  892                 sizeof (struct ip6_hdr),
  893                 offsetof(struct ip6_hdr, ip6_nxt));
  894         IPSECREQUEST_UNLOCK(isr);
  895         return error;
  896 bad:
  897         if (isr)
  898                 IPSECREQUEST_UNLOCK(isr);
  899         if (m)
  900                 m_freem(m);
  901         state->m = NULL;
  902         return error;
  903 }
  904 #endif /*INET6*/

Cache object: c78230da3a73b2af9af09abcfee5d079


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.