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/10.1/sys/netipsec/ipsec_output.c 264814 2014-04-23 11:22:54Z 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                         const int hlen = (ip->ip_hl << 2);
  209                         int size, off;
  210                         struct mbuf *mi;
  211                         struct udphdr *udp;
  212 
  213                         size = sizeof(struct udphdr);
  214                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
  215                                 /*
  216                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
  217                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
  218                                  * ignoring possible AH mode
  219                                  * non-IKE marker + non-ESP marker
  220                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
  221                                  */
  222                                 size += sizeof(u_int64_t);
  223                         }
  224                         mi = m_makespace(m, hlen, size, &off);
  225                         if (mi == NULL) {
  226                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
  227                                     __func__));
  228                                 error = ENOBUFS;
  229                                 goto bad;
  230                         }
  231 
  232                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
  233                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  234                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
  235                         else
  236                                 udp->uh_sport =
  237                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
  238                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
  239                         udp->uh_sum = 0;
  240                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
  241                         ip->ip_len = htons(m->m_pkthdr.len);
  242                         ip->ip_p = IPPROTO_UDP;
  243 
  244                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
  245                                 *(u_int64_t *)(udp + 1) = 0;
  246                 }
  247 #endif /* IPSEC_NAT_T */
  248 
  249                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
  250 #endif /* INET */
  251 #ifdef INET6
  252         case AF_INET6:
  253                 /*
  254                  * We don't need massage, IPv6 header fields are always in
  255                  * net endian.
  256                  */
  257                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
  258 #endif /* INET6 */
  259         }
  260         panic("ipsec_process_done");
  261 bad:
  262         m_freem(m);
  263         return (error);
  264 }
  265 
  266 static struct ipsecrequest *
  267 ipsec_nextisr(
  268         struct mbuf *m,
  269         struct ipsecrequest *isr,
  270         int af,
  271         struct secasindex *saidx,
  272         int *error
  273 )
  274 {
  275 #define IPSEC_OSTAT(name)       do {            \
  276         if (isr->saidx.proto == IPPROTO_ESP)    \
  277                 ESPSTAT_INC(esps_##name);       \
  278         else if (isr->saidx.proto == IPPROTO_AH)\
  279                 AHSTAT_INC(ahs_##name);         \
  280         else                                    \
  281                 IPCOMPSTAT_INC(ipcomps_##name); \
  282 } while (0)
  283         struct secasvar *sav;
  284 
  285         IPSECREQUEST_LOCK_ASSERT(isr);
  286 
  287         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
  288                 ("invalid address family %u", af));
  289 again:
  290         /*
  291          * Craft SA index to search for proper SA.  Note that
  292          * we only fillin unspecified SA peers for transport
  293          * mode; for tunnel mode they must already be filled in.
  294          */
  295         *saidx = isr->saidx;
  296         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
  297                 /* Fillin unspecified SA peers only for transport mode */
  298                 if (af == AF_INET) {
  299                         struct sockaddr_in *sin;
  300                         struct ip *ip = mtod(m, struct ip *);
  301 
  302                         if (saidx->src.sa.sa_len == 0) {
  303                                 sin = &saidx->src.sin;
  304                                 sin->sin_len = sizeof(*sin);
  305                                 sin->sin_family = AF_INET;
  306                                 sin->sin_port = IPSEC_PORT_ANY;
  307                                 sin->sin_addr = ip->ip_src;
  308                         }
  309                         if (saidx->dst.sa.sa_len == 0) {
  310                                 sin = &saidx->dst.sin;
  311                                 sin->sin_len = sizeof(*sin);
  312                                 sin->sin_family = AF_INET;
  313                                 sin->sin_port = IPSEC_PORT_ANY;
  314                                 sin->sin_addr = ip->ip_dst;
  315                         }
  316                 } else {
  317                         struct sockaddr_in6 *sin6;
  318                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  319 
  320                         if (saidx->src.sin6.sin6_len == 0) {
  321                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
  322                                 sin6->sin6_len = sizeof(*sin6);
  323                                 sin6->sin6_family = AF_INET6;
  324                                 sin6->sin6_port = IPSEC_PORT_ANY;
  325                                 sin6->sin6_addr = ip6->ip6_src;
  326                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  327                                         /* fix scope id for comparing SPD */
  328                                         sin6->sin6_addr.s6_addr16[1] = 0;
  329                                         sin6->sin6_scope_id =
  330                                             ntohs(ip6->ip6_src.s6_addr16[1]);
  331                                 }
  332                         }
  333                         if (saidx->dst.sin6.sin6_len == 0) {
  334                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
  335                                 sin6->sin6_len = sizeof(*sin6);
  336                                 sin6->sin6_family = AF_INET6;
  337                                 sin6->sin6_port = IPSEC_PORT_ANY;
  338                                 sin6->sin6_addr = ip6->ip6_dst;
  339                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
  340                                         /* fix scope id for comparing SPD */
  341                                         sin6->sin6_addr.s6_addr16[1] = 0;
  342                                         sin6->sin6_scope_id =
  343                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
  344                                 }
  345                         }
  346                 }
  347         }
  348 
  349         /*
  350          * Lookup SA and validate it.
  351          */
  352         *error = key_checkrequest(isr, saidx);
  353         if (*error != 0) {
  354                 /*
  355                  * IPsec processing is required, but no SA found.
  356                  * I assume that key_acquire() had been called
  357                  * to get/establish the SA. Here I discard
  358                  * this packet because it is responsibility for
  359                  * upper layer to retransmit the packet.
  360                  */
  361                 IPSECSTAT_INC(ips_out_nosa);
  362                 goto bad;
  363         }
  364         sav = isr->sav;
  365         if (sav == NULL) {
  366                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
  367                         ("no SA found, but required; level %u",
  368                         ipsec_get_reqlevel(isr)));
  369                 IPSECREQUEST_UNLOCK(isr);
  370                 isr = isr->next;
  371                 /*
  372                  * If isr is NULL, we found a 'use' policy w/o SA.
  373                  * Return w/o error and w/o isr so we can drop out
  374                  * and continue w/o IPsec processing.
  375                  */
  376                 if (isr == NULL)
  377                         return isr;
  378                 IPSECREQUEST_LOCK(isr);
  379                 goto again;
  380         }
  381 
  382         /*
  383          * Check system global policy controls.
  384          */
  385         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
  386             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
  387             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
  388                 DPRINTF(("%s: IPsec outbound packet dropped due"
  389                         " to policy (check your sysctls)\n", __func__));
  390                 IPSEC_OSTAT(pdrops);
  391                 *error = EHOSTUNREACH;
  392                 goto bad;
  393         }
  394 
  395         /*
  396          * Sanity check the SA contents for the caller
  397          * before they invoke the xform output method.
  398          */
  399         if (sav->tdb_xform == NULL) {
  400                 DPRINTF(("%s: no transform for SA\n", __func__));
  401                 IPSEC_OSTAT(noxform);
  402                 *error = EHOSTUNREACH;
  403                 goto bad;
  404         }
  405         return isr;
  406 bad:
  407         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
  408         IPSECREQUEST_UNLOCK(isr);
  409         return NULL;
  410 #undef IPSEC_OSTAT
  411 }
  412 
  413 #ifdef INET
  414 /*
  415  * IPsec output logic for IPv4.
  416  */
  417 int
  418 ipsec4_process_packet(
  419         struct mbuf *m,
  420         struct ipsecrequest *isr,
  421         int flags,
  422         int tunalready)
  423 {
  424         struct secasindex saidx;
  425         struct secasvar *sav;
  426         struct ip *ip;
  427         int error, i, off;
  428 
  429         IPSEC_ASSERT(m != NULL, ("null mbuf"));
  430         IPSEC_ASSERT(isr != NULL, ("null isr"));
  431 
  432         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  433 
  434         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
  435         if (isr == NULL) {
  436                 if (error != 0)
  437                         goto bad;
  438                 return EJUSTRETURN;
  439         }
  440 
  441         sav = isr->sav;
  442 
  443 #ifdef DEV_ENC
  444         encif->if_opackets++;
  445         encif->if_obytes += m->m_pkthdr.len;
  446 
  447         /* pass the mbuf to enc0 for bpf processing */
  448         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
  449         /* pass the mbuf to enc0 for packet filtering */
  450         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  451                 goto bad;
  452 #endif
  453 
  454         if (!tunalready) {
  455                 union sockaddr_union *dst = &sav->sah->saidx.dst;
  456                 int setdf;
  457 
  458                 /*
  459                  * Collect IP_DF state from the outer header.
  460                  */
  461                 if (dst->sa.sa_family == AF_INET) {
  462                         if (m->m_len < sizeof (struct ip) &&
  463                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  464                                 error = ENOBUFS;
  465                                 goto bad;
  466                         }
  467                         ip = mtod(m, struct ip *);
  468                         /* Honor system-wide control of how to handle IP_DF */
  469                         switch (V_ip4_ipsec_dfbit) {
  470                         case 0:                 /* clear in outer header */
  471                         case 1:                 /* set in outer header */
  472                                 setdf = V_ip4_ipsec_dfbit;
  473                                 break;
  474                         default:                /* propagate to outer header */
  475                                 setdf = ntohs(ip->ip_off & IP_DF);
  476                                 break;
  477                         }
  478                 } else {
  479                         ip = NULL;              /* keep compiler happy */
  480                         setdf = 0;
  481                 }
  482                 /* Do the appropriate encapsulation, if necessary */
  483                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
  484                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
  485 #if 0
  486                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
  487                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
  488 #endif
  489                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
  490                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
  491                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
  492                         struct mbuf *mp;
  493 
  494                         /* Fix IPv4 header checksum and length */
  495                         if (m->m_len < sizeof (struct ip) &&
  496                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  497                                 error = ENOBUFS;
  498                                 goto bad;
  499                         }
  500                         ip = mtod(m, struct ip *);
  501                         ip->ip_len = htons(m->m_pkthdr.len);
  502                         ip->ip_sum = 0;
  503                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
  504 
  505                         /* Encapsulate the packet */
  506                         error = ipip_output(m, isr, &mp, 0, 0);
  507                         if (mp == NULL && !error) {
  508                                 /* Should never happen. */
  509                                 DPRINTF(("%s: ipip_output returns no mbuf and "
  510                                         "no error!", __func__));
  511                                 error = EFAULT;
  512                         }
  513                         if (error) {
  514                                 if (mp) {
  515                                         /* XXX: Should never happen! */
  516                                         m_freem(mp);
  517                                 }
  518                                 m = NULL; /* ipip_output() already freed it */
  519                                 goto bad;
  520                         }
  521                         m = mp, mp = NULL;
  522                         /*
  523                          * ipip_output clears IP_DF in the new header.  If
  524                          * we need to propagate IP_DF from the outer header,
  525                          * then we have to do it here.
  526                          *
  527                          * XXX shouldn't assume what ipip_output does.
  528                          */
  529                         if (dst->sa.sa_family == AF_INET && setdf) {
  530                                 if (m->m_len < sizeof (struct ip) &&
  531                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  532                                         error = ENOBUFS;
  533                                         goto bad;
  534                                 }
  535                                 ip = mtod(m, struct ip *);
  536                                 ip->ip_off = ntohs(ip->ip_off);
  537                                 ip->ip_off |= IP_DF;
  538                                 ip->ip_off = htons(ip->ip_off);
  539                         }
  540                 }
  541         }
  542 
  543 #ifdef DEV_ENC
  544         /* pass the mbuf to enc0 for bpf processing */
  545         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
  546         /* pass the mbuf to enc0 for packet filtering */
  547         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  548                 goto bad;
  549 #endif
  550 
  551         /*
  552          * Dispatch to the appropriate IPsec transform logic.  The
  553          * packet will be returned for transmission after crypto
  554          * processing, etc. are completed.  For encapsulation we
  555          * bypass this call because of the explicit call done above
  556          * (necessary to deal with IP_DF handling for IPv4).
  557          *
  558          * NB: m & sav are ``passed to caller'' who's reponsible for
  559          *     for reclaiming their resources.
  560          */
  561         if (sav->tdb_xform->xf_type != XF_IP4) {
  562                 ip = mtod(m, struct ip *);
  563                 i = ip->ip_hl << 2;
  564                 off = offsetof(struct ip, ip_p);
  565                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
  566         } else {
  567                 error = ipsec_process_done(m, isr);
  568         }
  569         IPSECREQUEST_UNLOCK(isr);
  570         return error;
  571 bad:
  572         if (isr)
  573                 IPSECREQUEST_UNLOCK(isr);
  574         if (m)
  575                 m_freem(m);
  576         return error;
  577 }
  578 #endif
  579 
  580 #ifdef INET6
  581 /*
  582  * Chop IP6 header from the payload.
  583  */
  584 static struct mbuf *
  585 ipsec6_splithdr(struct mbuf *m)
  586 {
  587         struct mbuf *mh;
  588         struct ip6_hdr *ip6;
  589         int hlen;
  590 
  591         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
  592                 ("first mbuf too short, len %u", m->m_len));
  593         ip6 = mtod(m, struct ip6_hdr *);
  594         hlen = sizeof(struct ip6_hdr);
  595         if (m->m_len > hlen) {
  596                 MGETHDR(mh, M_NOWAIT, MT_DATA);
  597                 if (!mh) {
  598                         m_freem(m);
  599                         return NULL;
  600                 }
  601                 M_MOVE_PKTHDR(mh, m);
  602                 MH_ALIGN(mh, hlen);
  603                 m->m_len -= hlen;
  604                 m->m_data += hlen;
  605                 mh->m_next = m;
  606                 m = mh;
  607                 m->m_len = hlen;
  608                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
  609         } else if (m->m_len < hlen) {
  610                 m = m_pullup(m, hlen);
  611                 if (!m)
  612                         return NULL;
  613         }
  614         return m;
  615 }
  616 
  617 /*
  618  * IPsec output logic for IPv6, transport mode.
  619  */
  620 int
  621 ipsec6_output_trans(
  622         struct ipsec_output_state *state,
  623         u_char *nexthdrp,
  624         struct mbuf *mprev,
  625         struct secpolicy *sp,
  626         int flags,
  627         int *tun)
  628 {
  629         struct ipsecrequest *isr;
  630         struct secasindex saidx;
  631         int error = 0;
  632         struct mbuf *m;
  633 
  634         IPSEC_ASSERT(state != NULL, ("null state"));
  635         IPSEC_ASSERT(state->m != NULL, ("null m"));
  636         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
  637         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
  638         IPSEC_ASSERT(sp != NULL, ("null sp"));
  639         IPSEC_ASSERT(tun != NULL, ("null tun"));
  640 
  641         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  642                 printf("%s: applied SP\n", __func__);
  643                 kdebug_secpolicy(sp));
  644 
  645         isr = sp->req;
  646         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  647                 /* the rest will be handled by ipsec6_output_tunnel() */
  648                 *tun = 1;               /* need tunnel-mode processing */
  649                 return 0;
  650         }
  651 
  652         *tun = 0;
  653         m = state->m;
  654 
  655         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  656         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  657         if (isr == NULL) {
  658                 if (error != 0) {
  659 #ifdef notdef
  660                         /* XXX should notification be done for all errors ? */
  661                         /*
  662                          * Notify the fact that the packet is discarded
  663                          * to ourselves. I believe this is better than
  664                          * just silently discarding. (jinmei@kame.net)
  665                          * XXX: should we restrict the error to TCP packets?
  666                          * XXX: should we directly notify sockets via
  667                          *      pfctlinputs?
  668                          */
  669                         icmp6_error(m, ICMP6_DST_UNREACH,
  670                                     ICMP6_DST_UNREACH_ADMIN, 0);
  671                         m = NULL;       /* NB: icmp6_error frees mbuf */
  672 #endif
  673                         goto bad;
  674                 }
  675                 return EJUSTRETURN;
  676         }
  677 
  678         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  679                                                   sizeof (struct ip6_hdr),
  680                                                   offsetof(struct ip6_hdr, 
  681                                                            ip6_nxt));
  682         IPSECREQUEST_UNLOCK(isr);
  683         return error;
  684 bad:
  685         if (isr)
  686                 IPSECREQUEST_UNLOCK(isr);
  687         if (m)
  688                 m_freem(m);
  689         state->m = NULL;
  690         return error;
  691 }
  692 
  693 static int
  694 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
  695 {
  696         struct ip6_hdr *oip6;
  697         struct ip6_hdr *ip6;
  698         size_t plen;
  699 
  700         /* can't tunnel between different AFs */
  701         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
  702             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
  703                 m_freem(m);
  704                 return EINVAL;
  705         }
  706         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
  707                 ("mbuf wrong size; len %u", m->m_len));
  708 
  709 
  710         /*
  711          * grow the mbuf to accomodate the new IPv6 header.
  712          */
  713         plen = m->m_pkthdr.len;
  714         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
  715                 struct mbuf *n;
  716                 MGET(n, M_NOWAIT, MT_DATA);
  717                 if (!n) {
  718                         m_freem(m);
  719                         return ENOBUFS;
  720                 }
  721                 n->m_len = sizeof(struct ip6_hdr);
  722                 n->m_next = m->m_next;
  723                 m->m_next = n;
  724                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  725                 oip6 = mtod(n, struct ip6_hdr *);
  726         } else {
  727                 m->m_next->m_len += sizeof(struct ip6_hdr);
  728                 m->m_next->m_data -= sizeof(struct ip6_hdr);
  729                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  730                 oip6 = mtod(m->m_next, struct ip6_hdr *);
  731         }
  732         ip6 = mtod(m, struct ip6_hdr *);
  733         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
  734 
  735         /* Fake link-local scope-class addresses */
  736         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
  737                 oip6->ip6_src.s6_addr16[1] = 0;
  738         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
  739                 oip6->ip6_dst.s6_addr16[1] = 0;
  740 
  741         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
  742         /* ECN consideration. */
  743         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
  744         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
  745                 ip6->ip6_plen = htons(plen);
  746         else {
  747                 /* ip6->ip6_plen will be updated in ip6_output() */
  748         }
  749         ip6->ip6_nxt = IPPROTO_IPV6;
  750         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
  751         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
  752         ip6->ip6_hlim = IPV6_DEFHLIM;
  753 
  754         /* XXX Should ip6_src be updated later ? */
  755 
  756         return 0;
  757 }
  758 
  759 /*
  760  * IPsec output logic for IPv6, tunnel mode.
  761  */
  762 int
  763 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
  764 {
  765         struct ip6_hdr *ip6;
  766         struct ipsecrequest *isr;
  767         struct secasindex saidx;
  768         int error;
  769         struct sockaddr_in6 *dst6;
  770         struct mbuf *m;
  771 
  772         IPSEC_ASSERT(state != NULL, ("null state"));
  773         IPSEC_ASSERT(state->m != NULL, ("null m"));
  774         IPSEC_ASSERT(sp != NULL, ("null sp"));
  775 
  776         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  777                 printf("%s: applied SP\n", __func__);
  778                 kdebug_secpolicy(sp));
  779 
  780         m = state->m;
  781         /*
  782          * transport mode ipsec (before the 1st tunnel mode) is already
  783          * processed by ipsec6_output_trans().
  784          */
  785         for (isr = sp->req; isr; isr = isr->next) {
  786                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
  787                         break;
  788         }
  789 
  790         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  791         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  792         if (isr == NULL) {
  793                 if (error != 0)
  794                         goto bad;
  795                 return EJUSTRETURN; 
  796         }
  797 
  798 #ifdef DEV_ENC
  799         encif->if_opackets++;
  800         encif->if_obytes += m->m_pkthdr.len;
  801 
  802         /* pass the mbuf to enc0 for bpf processing */
  803         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
  804         /* pass the mbuf to enc0 for packet filtering */
  805         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
  806                 goto bad;
  807 #endif
  808 
  809         /*
  810          * There may be the case that SA status will be changed when
  811          * we are refering to one. So calling splsoftnet().
  812          */
  813         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  814                 /*
  815                  * build IPsec tunnel.
  816                  */
  817                 /* XXX should be processed with other familiy */
  818                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
  819                         ipseclog((LOG_ERR, "%s: family mismatched between "
  820                             "inner and outer, spi=%u\n", __func__,
  821                             ntohl(isr->sav->spi)));
  822                         IPSEC6STAT_INC(ips_out_inval);
  823                         error = EAFNOSUPPORT;
  824                         goto bad;
  825                 }
  826 
  827                 m = ipsec6_splithdr(m);
  828                 if (!m) {
  829                         IPSEC6STAT_INC(ips_out_nomem);
  830                         error = ENOMEM;
  831                         goto bad;
  832                 }
  833                 error = ipsec6_encapsulate(m, isr->sav);
  834                 if (error) {
  835                         m = NULL;
  836                         goto bad;
  837                 }
  838                 ip6 = mtod(m, struct ip6_hdr *);
  839 
  840                 state->ro =
  841                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
  842                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
  843                 dst6 = (struct sockaddr_in6 *)state->dst;
  844                 if (state->ro->ro_rt
  845                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
  846                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
  847                         RTFREE(state->ro->ro_rt);
  848                         state->ro->ro_rt = NULL;
  849                 }
  850                 if (state->ro->ro_rt == NULL) {
  851                         bzero(dst6, sizeof(*dst6));
  852                         dst6->sin6_family = AF_INET6;
  853                         dst6->sin6_len = sizeof(*dst6);
  854                         dst6->sin6_addr = ip6->ip6_dst;
  855                         rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
  856                 }
  857                 if (state->ro->ro_rt == NULL) {
  858                         IP6STAT_INC(ip6s_noroute);
  859                         IPSEC6STAT_INC(ips_out_noroute);
  860                         error = EHOSTUNREACH;
  861                         goto bad;
  862                 }
  863 
  864                 /* adjust state->dst if tunnel endpoint is offlink */
  865                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
  866                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
  867         }
  868 
  869         m = ipsec6_splithdr(m);
  870         if (!m) {
  871                 IPSEC6STAT_INC(ips_out_nomem);
  872                 error = ENOMEM;
  873                 goto bad;
  874         }
  875         ip6 = mtod(m, struct ip6_hdr *);
  876 
  877 #ifdef DEV_ENC
  878         /* pass the mbuf to enc0 for bpf processing */
  879         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
  880         /* pass the mbuf to enc0 for packet filtering */
  881         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
  882                 goto bad;
  883 #endif
  884 
  885         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  886                 sizeof (struct ip6_hdr),
  887                 offsetof(struct ip6_hdr, ip6_nxt));
  888         IPSECREQUEST_UNLOCK(isr);
  889         return error;
  890 bad:
  891         if (isr)
  892                 IPSECREQUEST_UNLOCK(isr);
  893         if (m)
  894                 m_freem(m);
  895         state->m = NULL;
  896         return error;
  897 }
  898 #endif /*INET6*/

Cache object: 7327a459305a203171578d2a7bc71505


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