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/6.3/sys/netipsec/ipsec_output.c 160632 2006-07-24 23:20:59Z thompsa $
   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/route.h>
   48 
   49 #include <netinet/in.h>
   50 #include <netinet/in_systm.h>
   51 #include <netinet/ip.h>
   52 #include <netinet/ip_var.h>
   53 #include <netinet/in_var.h>
   54 #include <netinet/ip_ecn.h>
   55 #ifdef INET6
   56 #include <netinet6/ip6_ecn.h>
   57 #endif
   58 
   59 #include <netinet/ip6.h>
   60 #ifdef INET6
   61 #include <netinet6/ip6_var.h>
   62 #endif
   63 #include <netinet/in_pcb.h>
   64 #ifdef INET6
   65 #include <netinet/icmp6.h>
   66 #endif
   67 
   68 #include <netipsec/ipsec.h>
   69 #ifdef INET6
   70 #include <netipsec/ipsec6.h>
   71 #endif
   72 #include <netipsec/ah_var.h>
   73 #include <netipsec/esp_var.h>
   74 #include <netipsec/ipcomp_var.h>
   75 
   76 #include <netipsec/xform.h>
   77 
   78 #include <netipsec/key.h>
   79 #include <netipsec/keydb.h>
   80 #include <netipsec/key_debug.h>
   81 
   82 #include <machine/in_cksum.h>
   83 
   84 int
   85 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
   86 {
   87         struct tdb_ident *tdbi;
   88         struct m_tag *mtag;
   89         struct secasvar *sav;
   90         struct secasindex *saidx;
   91         int error;
   92 
   93         IPSEC_SPLASSERT_SOFTNET(__func__);
   94 
   95         IPSEC_ASSERT(m != NULL, ("null mbuf"));
   96         IPSEC_ASSERT(isr != NULL, ("null ISR"));
   97         sav = isr->sav;
   98         IPSEC_ASSERT(sav != NULL, ("null SA"));
   99         IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
  100 
  101         saidx = &sav->sah->saidx;
  102         switch (saidx->dst.sa.sa_family) {
  103 #ifdef INET
  104         case AF_INET:
  105                 /* Fix the header length, for AH processing. */
  106                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
  107                 break;
  108 #endif /* INET */
  109 #ifdef INET6
  110         case AF_INET6:
  111                 /* Fix the header length, for AH processing. */
  112                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
  113                         error = ENXIO;
  114                         goto bad;
  115                 }
  116                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
  117                         /* No jumbogram support. */
  118                         error = ENXIO;  /*?*/
  119                         goto bad;
  120                 }
  121                 mtod(m, struct ip6_hdr *)->ip6_plen =
  122                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
  123                 break;
  124 #endif /* INET6 */
  125         default:
  126                 DPRINTF(("%s: unknown protocol family %u\n", __func__,
  127                     saidx->dst.sa.sa_family));
  128                 error = ENXIO;
  129                 goto bad;
  130         }
  131 
  132         /*
  133          * Add a record of what we've done or what needs to be done to the
  134          * packet.
  135          */
  136         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
  137                         sizeof(struct tdb_ident), M_NOWAIT);
  138         if (mtag == NULL) {
  139                 DPRINTF(("%s: could not get packet tag\n", __func__));
  140                 error = ENOMEM;
  141                 goto bad;
  142         }
  143 
  144         tdbi = (struct tdb_ident *)(mtag + 1);
  145         tdbi->dst = saidx->dst;
  146         tdbi->proto = saidx->proto;
  147         tdbi->spi = sav->spi;
  148         m_tag_prepend(m, mtag);
  149 
  150         /*
  151          * If there's another (bundled) SA to apply, do so.
  152          * Note that this puts a burden on the kernel stack size.
  153          * If this is a problem we'll need to introduce a queue
  154          * to set the packet on so we can unwind the stack before
  155          * doing further processing.
  156          */
  157         if (isr->next) {
  158                 newipsecstat.ips_out_bundlesa++;
  159                 return ipsec4_process_packet(m, isr->next, 0, 0);
  160         }
  161         key_sa_recordxfer(sav, m);              /* record data transfer */
  162 
  163         /*
  164          * We're done with IPsec processing, transmit the packet using the
  165          * appropriate network protocol (IP or IPv6). SPD lookup will be
  166          * performed again there.
  167          */
  168         switch (saidx->dst.sa.sa_family) {
  169 #ifdef INET
  170         struct ip *ip;
  171         case AF_INET:
  172                 ip = mtod(m, struct ip *);
  173                 ip->ip_len = ntohs(ip->ip_len);
  174                 ip->ip_off = ntohs(ip->ip_off);
  175 
  176                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
  177 #endif /* INET */
  178 #ifdef INET6
  179         case AF_INET6:
  180                 /*
  181                  * We don't need massage, IPv6 header fields are always in
  182                  * net endian.
  183                  */
  184                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
  185 #endif /* INET6 */
  186         }
  187         panic("ipsec_process_done");
  188 bad:
  189         m_freem(m);
  190         KEY_FREESAV(&sav);
  191         return (error);
  192 }
  193 
  194 static struct ipsecrequest *
  195 ipsec_nextisr(
  196         struct mbuf *m,
  197         struct ipsecrequest *isr,
  198         int af,
  199         struct secasindex *saidx,
  200         int *error
  201 )
  202 {
  203 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
  204                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
  205         struct secasvar *sav;
  206 
  207         IPSEC_SPLASSERT_SOFTNET(__func__);
  208         IPSECREQUEST_LOCK_ASSERT(isr);
  209 
  210         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
  211                 ("invalid address family %u", af));
  212 again:
  213         /*
  214          * Craft SA index to search for proper SA.  Note that
  215          * we only fillin unspecified SA peers for transport
  216          * mode; for tunnel mode they must already be filled in.
  217          */
  218         *saidx = isr->saidx;
  219         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
  220                 /* Fillin unspecified SA peers only for transport mode */
  221                 if (af == AF_INET) {
  222                         struct sockaddr_in *sin;
  223                         struct ip *ip = mtod(m, struct ip *);
  224 
  225                         if (saidx->src.sa.sa_len == 0) {
  226                                 sin = &saidx->src.sin;
  227                                 sin->sin_len = sizeof(*sin);
  228                                 sin->sin_family = AF_INET;
  229                                 sin->sin_port = IPSEC_PORT_ANY;
  230                                 sin->sin_addr = ip->ip_src;
  231                         }
  232                         if (saidx->dst.sa.sa_len == 0) {
  233                                 sin = &saidx->dst.sin;
  234                                 sin->sin_len = sizeof(*sin);
  235                                 sin->sin_family = AF_INET;
  236                                 sin->sin_port = IPSEC_PORT_ANY;
  237                                 sin->sin_addr = ip->ip_dst;
  238                         }
  239                 } else {
  240                         struct sockaddr_in6 *sin6;
  241                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  242 
  243                         if (saidx->src.sin6.sin6_len == 0) {
  244                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
  245                                 sin6->sin6_len = sizeof(*sin6);
  246                                 sin6->sin6_family = AF_INET6;
  247                                 sin6->sin6_port = IPSEC_PORT_ANY;
  248                                 sin6->sin6_addr = ip6->ip6_src;
  249                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
  250                                         /* fix scope id for comparing SPD */
  251                                         sin6->sin6_addr.s6_addr16[1] = 0;
  252                                         sin6->sin6_scope_id =
  253                                             ntohs(ip6->ip6_src.s6_addr16[1]);
  254                                 }
  255                         }
  256                         if (saidx->dst.sin6.sin6_len == 0) {
  257                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
  258                                 sin6->sin6_len = sizeof(*sin6);
  259                                 sin6->sin6_family = AF_INET6;
  260                                 sin6->sin6_port = IPSEC_PORT_ANY;
  261                                 sin6->sin6_addr = ip6->ip6_dst;
  262                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
  263                                         /* fix scope id for comparing SPD */
  264                                         sin6->sin6_addr.s6_addr16[1] = 0;
  265                                         sin6->sin6_scope_id =
  266                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
  267                                 }
  268                         }
  269                 }
  270         }
  271 
  272         /*
  273          * Lookup SA and validate it.
  274          */
  275         *error = key_checkrequest(isr, saidx);
  276         if (*error != 0) {
  277                 /*
  278                  * IPsec processing is required, but no SA found.
  279                  * I assume that key_acquire() had been called
  280                  * to get/establish the SA. Here I discard
  281                  * this packet because it is responsibility for
  282                  * upper layer to retransmit the packet.
  283                  */
  284                 newipsecstat.ips_out_nosa++;
  285                 goto bad;
  286         }
  287         sav = isr->sav;
  288         if (sav == NULL) {              /* XXX valid return */
  289                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
  290                         ("no SA found, but required; level %u",
  291                         ipsec_get_reqlevel(isr)));
  292                 IPSECREQUEST_UNLOCK(isr);
  293                 isr = isr->next;
  294                 if (isr == NULL) {
  295                         /*XXXstatistic??*/
  296                         *error = EINVAL;                /*XXX*/
  297                         return isr;
  298                 }
  299                 IPSECREQUEST_LOCK(isr);
  300                 goto again;
  301         }
  302 
  303         /*
  304          * Check system global policy controls.
  305          */
  306         if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
  307             (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
  308             (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
  309                 DPRINTF(("%s: IPsec outbound packet dropped due"
  310                         " to policy (check your sysctls)\n", __func__));
  311                 IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
  312                     ipcompstat.ipcomps_pdrops);
  313                 *error = EHOSTUNREACH;
  314                 goto bad;
  315         }
  316 
  317         /*
  318          * Sanity check the SA contents for the caller
  319          * before they invoke the xform output method.
  320          */
  321         if (sav->tdb_xform == NULL) {
  322                 DPRINTF(("%s: no transform for SA\n", __func__));
  323                 IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
  324                     ipcompstat.ipcomps_noxform);
  325                 *error = EHOSTUNREACH;
  326                 goto bad;
  327         }
  328         return isr;
  329 bad:
  330         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
  331         IPSECREQUEST_UNLOCK(isr);
  332         return NULL;
  333 #undef IPSEC_OSTAT
  334 }
  335 
  336 #ifdef INET
  337 /*
  338  * IPsec output logic for IPv4.
  339  */
  340 int
  341 ipsec4_process_packet(
  342         struct mbuf *m,
  343         struct ipsecrequest *isr,
  344         int flags,
  345         int tunalready)
  346 {
  347         struct secasindex saidx;
  348         struct secasvar *sav;
  349         struct ip *ip;
  350         int error, i, off;
  351 
  352         IPSEC_ASSERT(m != NULL, ("null mbuf"));
  353         IPSEC_ASSERT(isr != NULL, ("null isr"));
  354 
  355         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
  356 
  357         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
  358         if (isr == NULL)
  359                 goto bad;
  360 
  361         sav = isr->sav;
  362 
  363 #ifdef DEV_ENC
  364         /* pass the mbuf to enc0 for packet filtering */
  365         if ((error = ipsec_filter(&m, 2)) != 0)
  366                 goto bad;
  367 #endif
  368 
  369         if (!tunalready) {
  370                 union sockaddr_union *dst = &sav->sah->saidx.dst;
  371                 int setdf;
  372 
  373                 /*
  374                  * Collect IP_DF state from the outer header.
  375                  */
  376                 if (dst->sa.sa_family == AF_INET) {
  377                         if (m->m_len < sizeof (struct ip) &&
  378                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  379                                 error = ENOBUFS;
  380                                 goto bad;
  381                         }
  382                         ip = mtod(m, struct ip *);
  383                         /* Honor system-wide control of how to handle IP_DF */
  384                         switch (ip4_ipsec_dfbit) {
  385                         case 0:                 /* clear in outer header */
  386                         case 1:                 /* set in outer header */
  387                                 setdf = ip4_ipsec_dfbit;
  388                                 break;
  389                         default:                /* propagate to outer header */
  390                                 setdf = ntohs(ip->ip_off & IP_DF);
  391                                 break;
  392                         }
  393                 } else {
  394                         ip = NULL;              /* keep compiler happy */
  395                         setdf = 0;
  396                 }
  397                 /* Do the appropriate encapsulation, if necessary */
  398                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
  399                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
  400 #if 0
  401                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
  402                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
  403 #endif
  404                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
  405                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
  406                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
  407                         struct mbuf *mp;
  408 
  409                         /* Fix IPv4 header checksum and length */
  410                         if (m->m_len < sizeof (struct ip) &&
  411                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  412                                 error = ENOBUFS;
  413                                 goto bad;
  414                         }
  415                         ip = mtod(m, struct ip *);
  416                         ip->ip_len = htons(m->m_pkthdr.len);
  417                         ip->ip_sum = 0;
  418 #ifdef _IP_VHL
  419                         if (ip->ip_vhl == IP_VHL_BORING)
  420                                 ip->ip_sum = in_cksum_hdr(ip);
  421                         else
  422                                 ip->ip_sum = in_cksum(m,
  423                                         _IP_VHL_HL(ip->ip_vhl) << 2);
  424 #else
  425                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
  426 #endif
  427 
  428                         /* Encapsulate the packet */
  429                         error = ipip_output(m, isr, &mp, 0, 0);
  430                         if (mp == NULL && !error) {
  431                                 /* Should never happen. */
  432                                 DPRINTF(("%s: ipip_output returns no mbuf and "
  433                                         "no error!", __func__));
  434                                 error = EFAULT;
  435                         }
  436                         if (error) {
  437                                 if (mp) {
  438                                         /* XXX: Should never happen! */
  439                                         m_freem(mp);
  440                                 }
  441                                 m = NULL; /* ipip_output() already freed it */
  442                                 goto bad;
  443                         }
  444                         m = mp, mp = NULL;
  445                         /*
  446                          * ipip_output clears IP_DF in the new header.  If
  447                          * we need to propagate IP_DF from the outer header,
  448                          * then we have to do it here.
  449                          *
  450                          * XXX shouldn't assume what ipip_output does.
  451                          */
  452                         if (dst->sa.sa_family == AF_INET && setdf) {
  453                                 if (m->m_len < sizeof (struct ip) &&
  454                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
  455                                         error = ENOBUFS;
  456                                         goto bad;
  457                                 }
  458                                 ip = mtod(m, struct ip *);
  459                                 ip->ip_off = ntohs(ip->ip_off);
  460                                 ip->ip_off |= IP_DF;
  461                                 ip->ip_off = htons(ip->ip_off);
  462                         }
  463                 }
  464         }
  465 
  466 #ifdef DEV_ENC
  467         /* pass the mbuf to enc0 for bpf processing */
  468         ipsec_bpf(m, sav, AF_INET);
  469 #endif
  470 
  471         /*
  472          * Dispatch to the appropriate IPsec transform logic.  The
  473          * packet will be returned for transmission after crypto
  474          * processing, etc. are completed.  For encapsulation we
  475          * bypass this call because of the explicit call done above
  476          * (necessary to deal with IP_DF handling for IPv4).
  477          *
  478          * NB: m & sav are ``passed to caller'' who's reponsible for
  479          *     for reclaiming their resources.
  480          */
  481         if (sav->tdb_xform->xf_type != XF_IP4) {
  482                 ip = mtod(m, struct ip *);
  483                 i = ip->ip_hl << 2;
  484                 off = offsetof(struct ip, ip_p);
  485                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
  486         } else {
  487                 error = ipsec_process_done(m, isr);
  488         }
  489         IPSECREQUEST_UNLOCK(isr);
  490         return error;
  491 bad:
  492         if (isr)
  493                 IPSECREQUEST_UNLOCK(isr);
  494         if (m)
  495                 m_freem(m);
  496         return error;
  497 }
  498 #endif
  499 
  500 #ifdef INET6
  501 /*
  502  * Chop IP6 header from the payload.
  503  */
  504 static struct mbuf *
  505 ipsec6_splithdr(struct mbuf *m)
  506 {
  507         struct mbuf *mh;
  508         struct ip6_hdr *ip6;
  509         int hlen;
  510 
  511         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
  512                 ("first mbuf too short, len %u", m->m_len));
  513         ip6 = mtod(m, struct ip6_hdr *);
  514         hlen = sizeof(struct ip6_hdr);
  515         if (m->m_len > hlen) {
  516                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
  517                 if (!mh) {
  518                         m_freem(m);
  519                         return NULL;
  520                 }
  521                 M_MOVE_PKTHDR(mh, m);
  522                 MH_ALIGN(mh, hlen);
  523                 m->m_len -= hlen;
  524                 m->m_data += hlen;
  525                 mh->m_next = m;
  526                 m = mh;
  527                 m->m_len = hlen;
  528                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
  529         } else if (m->m_len < hlen) {
  530                 m = m_pullup(m, hlen);
  531                 if (!m)
  532                         return NULL;
  533         }
  534         return m;
  535 }
  536 
  537 /*
  538  * IPsec output logic for IPv6, transport mode.
  539  */
  540 int
  541 ipsec6_output_trans(
  542         struct ipsec_output_state *state,
  543         u_char *nexthdrp,
  544         struct mbuf *mprev,
  545         struct secpolicy *sp,
  546         int flags,
  547         int *tun)
  548 {
  549         struct ipsecrequest *isr;
  550         struct secasindex saidx;
  551         int error = 0;
  552         struct mbuf *m;
  553 
  554         IPSEC_ASSERT(state != NULL, ("null state"));
  555         IPSEC_ASSERT(state->m != NULL, ("null m"));
  556         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
  557         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
  558         IPSEC_ASSERT(sp != NULL, ("null sp"));
  559         IPSEC_ASSERT(tun != NULL, ("null tun"));
  560 
  561         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  562                 printf("%s: applyed SP\n", __func__);
  563                 kdebug_secpolicy(sp));
  564 
  565         isr = sp->req;
  566         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  567                 /* the rest will be handled by ipsec6_output_tunnel() */
  568                 *tun = 1;               /* need tunnel-mode processing */
  569                 return 0;
  570         }
  571 
  572         *tun = 0;
  573         m = state->m;
  574 
  575         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  576         if (isr == NULL) {
  577 #ifdef notdef
  578                 /* XXX should notification be done for all errors ? */
  579                 /*
  580                  * Notify the fact that the packet is discarded
  581                  * to ourselves. I believe this is better than
  582                  * just silently discarding. (jinmei@kame.net)
  583                  * XXX: should we restrict the error to TCP packets?
  584                  * XXX: should we directly notify sockets via
  585                  *      pfctlinputs?
  586                  */
  587                 icmp6_error(m, ICMP6_DST_UNREACH,
  588                             ICMP6_DST_UNREACH_ADMIN, 0);
  589                 m = NULL;       /* NB: icmp6_error frees mbuf */
  590 #endif
  591                 goto bad;
  592         }
  593 
  594         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  595                 sizeof (struct ip6_hdr),
  596                 offsetof(struct ip6_hdr, ip6_nxt));
  597 bad:
  598         if (m)
  599                 m_freem(m);
  600         state->m = NULL;
  601         return error;
  602 }
  603 
  604 static int
  605 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
  606 {
  607         struct ip6_hdr *oip6;
  608         struct ip6_hdr *ip6;
  609         size_t plen;
  610 
  611         /* can't tunnel between different AFs */
  612         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
  613             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
  614                 m_freem(m);
  615                 return EINVAL;
  616         }
  617         IPSEC_ASSERT(m->m_len != sizeof (struct ip6_hdr),
  618                 ("mbuf wrong size; len %u", m->m_len));
  619 
  620 
  621         /*
  622          * grow the mbuf to accomodate the new IPv6 header.
  623          */
  624         plen = m->m_pkthdr.len;
  625         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
  626                 struct mbuf *n;
  627                 MGET(n, M_DONTWAIT, MT_DATA);
  628                 if (!n) {
  629                         m_freem(m);
  630                         return ENOBUFS;
  631                 }
  632                 n->m_len = sizeof(struct ip6_hdr);
  633                 n->m_next = m->m_next;
  634                 m->m_next = n;
  635                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  636                 oip6 = mtod(n, struct ip6_hdr *);
  637         } else {
  638                 m->m_next->m_len += sizeof(struct ip6_hdr);
  639                 m->m_next->m_data -= sizeof(struct ip6_hdr);
  640                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
  641                 oip6 = mtod(m->m_next, struct ip6_hdr *);
  642         }
  643         ip6 = mtod(m, struct ip6_hdr *);
  644         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
  645 
  646         /* Fake link-local scope-class addresses */
  647         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
  648                 oip6->ip6_src.s6_addr16[1] = 0;
  649         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
  650                 oip6->ip6_dst.s6_addr16[1] = 0;
  651 
  652         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
  653         /* ECN consideration. */
  654         ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
  655         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
  656                 ip6->ip6_plen = htons(plen);
  657         else {
  658                 /* ip6->ip6_plen will be updated in ip6_output() */
  659         }
  660         ip6->ip6_nxt = IPPROTO_IPV6;
  661         sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
  662         sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
  663         ip6->ip6_hlim = IPV6_DEFHLIM;
  664 
  665         /* XXX Should ip6_src be updated later ? */
  666 
  667         return 0;
  668 }
  669 
  670 /*
  671  * IPsec output logic for IPv6, tunnel mode.
  672  */
  673 int
  674 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
  675 {
  676         struct ip6_hdr *ip6;
  677         struct ipsecrequest *isr;
  678         struct secasindex saidx;
  679         int error;
  680         struct sockaddr_in6* dst6;
  681         struct mbuf *m;
  682 
  683         IPSEC_ASSERT(state != NULL, ("null state"));
  684         IPSEC_ASSERT(state->m != NULL, ("null m"));
  685         IPSEC_ASSERT(sp != NULL, ("null sp"));
  686 
  687         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
  688                 printf("%s: applyed SP\n", __func__);
  689                 kdebug_secpolicy(sp));
  690 
  691         m = state->m;
  692         /*
  693          * transport mode ipsec (before the 1st tunnel mode) is already
  694          * processed by ipsec6_output_trans().
  695          */
  696         for (isr = sp->req; isr; isr = isr->next) {
  697                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
  698                         break;
  699         }
  700         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
  701         if (isr == NULL)
  702                 goto bad;
  703 
  704         /*
  705          * There may be the case that SA status will be changed when
  706          * we are refering to one. So calling splsoftnet().
  707          */
  708         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
  709                 /*
  710                  * build IPsec tunnel.
  711                  */
  712                 /* XXX should be processed with other familiy */
  713                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
  714                         ipseclog((LOG_ERR, "%s: family mismatched between "
  715                             "inner and outer, spi=%u\n", __func__,
  716                             ntohl(isr->sav->spi)));
  717                         newipsecstat.ips_out_inval++;
  718                         error = EAFNOSUPPORT;
  719                         goto bad;
  720                 }
  721 
  722                 m = ipsec6_splithdr(m);
  723                 if (!m) {
  724                         newipsecstat.ips_out_nomem++;
  725                         error = ENOMEM;
  726                         goto bad;
  727                 }
  728                 error = ipsec6_encapsulate(m, isr->sav);
  729                 if (error) {
  730                         m = NULL;
  731                         goto bad;
  732                 }
  733                 ip6 = mtod(m, struct ip6_hdr *);
  734 
  735                 state->ro = &isr->sav->sah->sa_route;
  736                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
  737                 dst6 = (struct sockaddr_in6 *)state->dst;
  738                 if (state->ro->ro_rt
  739                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
  740                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
  741                         RTFREE(state->ro->ro_rt);
  742                         state->ro->ro_rt = NULL;
  743                 }
  744                 if (state->ro->ro_rt == 0) {
  745                         bzero(dst6, sizeof(*dst6));
  746                         dst6->sin6_family = AF_INET6;
  747                         dst6->sin6_len = sizeof(*dst6);
  748                         dst6->sin6_addr = ip6->ip6_dst;
  749                         rtalloc(state->ro);
  750                 }
  751                 if (state->ro->ro_rt == 0) {
  752                         ip6stat.ip6s_noroute++;
  753                         newipsecstat.ips_out_noroute++;
  754                         error = EHOSTUNREACH;
  755                         goto bad;
  756                 }
  757 
  758                 /* adjust state->dst if tunnel endpoint is offlink */
  759                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
  760                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
  761                         dst6 = (struct sockaddr_in6 *)state->dst;
  762                 }
  763         }
  764 
  765         m = ipsec6_splithdr(m);
  766         if (!m) {
  767                 newipsecstat.ips_out_nomem++;
  768                 error = ENOMEM;
  769                 goto bad;
  770         }
  771         ip6 = mtod(m, struct ip6_hdr *);
  772         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
  773                 sizeof (struct ip6_hdr),
  774                 offsetof(struct ip6_hdr, ip6_nxt));
  775 bad:
  776         if (m)
  777                 m_freem(m);
  778         state->m = NULL;
  779         return error;
  780 }
  781 #endif /*INET6*/

Cache object: 44f602da39be93140c1fb1b2c8046180


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