sys/netproto/ipsec/ipsec_output.c

   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: src/sys/netipsec/ipsec_output.c,v 1.3.2.2 2003/03/28 20:32:53 sam Exp $
  27  * $DragonFly: src/sys/netproto/ipsec/ipsec_output.c,v 1.12 2008/05/27 01:10:44 dillon Exp $
  28  */
  29
  30 /*
  31  * IPsec output processing.
  32  */
  33 #include "opt_inet.h"
  34 #include "opt_inet6.h"
  35 #include "opt_ipsec.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 #include <sys/in_cksum.h>
  46
  47 #include <net/if.h>
  48 #include <net/route.h>
  49
  50 #include <netinet/in.h>
  51 #include <netinet/in_systm.h>
  52 #include <netinet/ip.h>
  53 #include <netinet/ip_var.h>
  54 #include <netinet/in_var.h>
  55 #include <netinet/ip_ecn.h>
  56 #ifdef INET6
  57 #include <netinet6/ip6_ecn.h>
  58 #endif
  59
  60 #include <netinet/ip6.h>
  61 #ifdef INET6
  62 #include <netinet6/ip6_var.h>
  63 #endif
  64 #include <netinet/in_pcb.h>
  65 #ifdef INET6
  66 #include <netinet/icmp6.h>
  67 #endif
  68
  69 #include <netproto/ipsec/ipsec.h>
  70 #ifdef INET6
  71 #include <netproto/ipsec/ipsec6.h>
  72 #endif
  73 #include <netproto/ipsec/ah_var.h>
  74 #include <netproto/ipsec/esp_var.h>
  75 #include <netproto/ipsec/ipcomp_var.h>
  76
  77 #include <netproto/ipsec/xform.h>
  78
  79 #include <netproto/ipsec/key.h>
  80 #include <netproto/ipsec/keydb.h>
  81 #include <netproto/ipsec/key_debug.h>
  82
  83 int
  84 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
  85 {
  86         struct tdb_ident *tdbi;
  87         struct m_tag *mtag;
  88         struct secasvar *sav;
  89         struct secasindex *saidx;
  90         int error;
  91
  92         KASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
  93         KASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
  94         sav = isr->sav;
  95         KASSERT(sav != NULL, ("ipsec_process_done: null SA"));
  96         KASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH"));
  97
  98         saidx = &sav->sah->saidx;
  99         switch (saidx->dst.sa.sa_family) {
 100 #ifdef INET
 101         case AF_INET:
 102                 /* Fix the header length, for AH processing. */
 103                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 104                 break;
 105 #endif /* INET */
 106 #ifdef INET6
 107         case AF_INET6:
 108                 /* Fix the header length, for AH processing. */
 109                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
 110                         error = ENXIO;
 111                         goto bad;
 112                 }
 113                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
 114                         /* No jumbogram support. */
 115                         error = ENXIO;  /*?*/
 116                         goto bad;
 117                 }
 118                 mtod(m, struct ip6_hdr *)->ip6_plen =
 119                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 120                 break;
 121 #endif /* INET6 */
 122         default:
 123                 DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
 124                     saidx->dst.sa.sa_family));
 125                 error = ENXIO;
 126                 goto bad;
 127         }
 128
 129         /*
 130          * Add a record of what we've done or what needs to be done to the
 131          * packet.
 132          */
 133         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
 134                          sizeof(struct tdb_ident), MB_DONTWAIT);
 135         if (mtag == NULL) {
 136                 DPRINTF(("ipsec_process_done: could not get packet tag\n"));
 137                 error = ENOMEM;
 138                 goto bad;
 139         }
 140
 141         tdbi = (struct tdb_ident *)m_tag_data(mtag);
 142         tdbi->dst = saidx->dst;
 143         tdbi->proto = saidx->proto;
 144         tdbi->spi = sav->spi;
 145         m_tag_prepend(m, mtag);
 146
 147         /*
 148          * If there's another (bundled) SA to apply, do so.
 149          * Note that this puts a burden on the kernel stack size.
 150          * If this is a problem we'll need to introduce a queue
 151          * to set the packet on so we can unwind the stack before
 152          * doing further processing.
 153          */
 154         if (isr->next) {
 155                 newipsecstat.ips_out_bundlesa++;
 156                 return ipsec4_process_packet(m, isr->next, 0, 0);
 157         }
 158
 159         /*
 160          * We're done with IPsec processing, transmit the packet using the
 161          * appropriate network protocol (IP or IPv6). SPD lookup will be
 162          * performed again there.
 163          */
 164         switch (saidx->dst.sa.sa_family) {
 165 #ifdef INET
 166         struct ip *ip;
 167         case AF_INET:
 168                 ip = mtod(m, struct ip *);
 169                 ip->ip_len = ntohs(ip->ip_len);
 170                 ip->ip_off = ntohs(ip->ip_off);
 171
 172                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 173 #endif /* INET */
 174 #ifdef INET6
 175         case AF_INET6:
 176                 /*
 177                  * We don't need massage, IPv6 header fields are always in
 178                  * net endian.
 179                  */
 180                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 181 #endif /* INET6 */
 182         }
 183         panic("ipsec_process_done");
 184 bad:
 185         m_freem(m);
 186         KEY_FREESAV(&sav);
 187         return (error);
 188 }
 189
 190 static struct ipsecrequest *
 191 ipsec_nextisr(
 192         struct mbuf *m,
 193         struct ipsecrequest *isr,
 194         int af,
 195         struct secasindex *saidx,
 196         int *error
 197 )
 198 {
 199 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
 200                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
 201         struct secasvar *sav;
 202
 203         KASSERT(af == AF_INET || af == AF_INET6,
 204                 ("ipsec_nextisr: invalid address family %u", af));
 205 again:
 206         /*
 207          * Craft SA index to search for proper SA.  Note that
 208          * we only fillin unspecified SA peers for transport
 209          * mode; for tunnel mode they must already be filled in.
 210          */
 211         *saidx = isr->saidx;
 212         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 213                 /* Fillin unspecified SA peers only for transport mode */
 214                 if (af == AF_INET) {
 215                         struct sockaddr_in *sin;
 216                         struct ip *ip = mtod(m, struct ip *);
 217
 218                         if (saidx->src.sa.sa_len == 0) {
 219                                 sin = &saidx->src.sin;
 220                                 sin->sin_len = sizeof(*sin);
 221                                 sin->sin_family = AF_INET;
 222                                 sin->sin_port = IPSEC_PORT_ANY;
 223                                 sin->sin_addr = ip->ip_src;
 224                         }
 225                         if (saidx->dst.sa.sa_len == 0) {
 226                                 sin = &saidx->dst.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_dst;
 231                         }
 232                 } else {
 233                         struct sockaddr_in6 *sin6;
 234                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 235
 236                         if (saidx->src.sin6.sin6_len == 0) {
 237                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 238                                 sin6->sin6_len = sizeof(*sin6);
 239                                 sin6->sin6_family = AF_INET6;
 240                                 sin6->sin6_port = IPSEC_PORT_ANY;
 241                                 sin6->sin6_addr = ip6->ip6_src;
 242                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 243                                         /* fix scope id for comparing SPD */
 244                                         sin6->sin6_addr.s6_addr16[1] = 0;
 245                                         sin6->sin6_scope_id =
 246                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 247                                 }
 248                         }
 249                         if (saidx->dst.sin6.sin6_len == 0) {
 250                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 251                                 sin6->sin6_len = sizeof(*sin6);
 252                                 sin6->sin6_family = AF_INET6;
 253                                 sin6->sin6_port = IPSEC_PORT_ANY;
 254                                 sin6->sin6_addr = ip6->ip6_dst;
 255                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 256                                         /* fix scope id for comparing SPD */
 257                                         sin6->sin6_addr.s6_addr16[1] = 0;
 258                                         sin6->sin6_scope_id =
 259                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 260                                 }
 261                         }
 262                 }
 263         }
 264
 265         /*
 266          * Lookup SA and validate it.
 267          */
 268         *error = key_checkrequest(isr, saidx);
 269         if (*error != 0) {
 270                 /*
 271                  * IPsec processing is required, but no SA found.
 272                  * I assume that key_acquire() had been called
 273                  * to get/establish the SA. Here I discard
 274                  * this packet because it is responsibility for
 275                  * upper layer to retransmit the packet.
 276                  */
 277                 newipsecstat.ips_out_nosa++;
 278                 goto bad;
 279         }
 280         sav = isr->sav;
 281         if (sav == NULL) {              /* XXX valid return */
 282                 KASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 283                         ("ipsec_nextisr: no SA found, but required; level %u",
 284                         ipsec_get_reqlevel(isr)));
 285                 isr = isr->next;
 286                 if (isr == NULL) {
 287                         /*XXXstatistic??*/
 288                         *error = EINVAL;                /*XXX*/
 289                         return isr;
 290                 }
 291                 goto again;
 292         }
 293
 294         /*
 295          * Check system global policy controls.
 296          */
 297         if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
 298             (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
 299             (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
 300                 DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
 301                         " to policy (check your sysctls)\n"));
 302                 IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
 303                     ipcompstat.ipcomps_pdrops);
 304                 *error = EHOSTUNREACH;
 305                 goto bad;
 306         }
 307
 308         /*
 309          * Sanity check the SA contents for the caller
 310          * before they invoke the xform output method.
 311          */
 312         if (sav->tdb_xform == NULL) {
 313                 DPRINTF(("ipsec_nextisr: no transform for SA\n"));
 314                 IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
 315                     ipcompstat.ipcomps_noxform);
 316                 *error = EHOSTUNREACH;
 317                 goto bad;
 318         }
 319         return isr;
 320 bad:
 321         KASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
 322         return NULL;
 323 #undef IPSEC_OSTAT
 324 }
 325
 326 #ifdef INET
 327 /*
 328  * IPsec output logic for IPv4.
 329  */
 330 int
 331 ipsec4_process_packet(
 332         struct mbuf *m,
 333         struct ipsecrequest *isr,
 334         int flags,
 335         int tunalready)
 336 {
 337         struct secasindex saidx;
 338         struct secasvar *sav;
 339         struct ip *ip;
 340         int error, i, off;
 341
 342         KASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
 343         KASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
 344
 345         crit_enter();
 346
 347         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 348         if (isr == NULL)
 349                 goto bad;
 350
 351         sav = isr->sav;
 352         if (!tunalready) {
 353                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 354                 int setdf;
 355
 356                 /*
 357                  * Collect IP_DF state from the outer header.
 358                  */
 359                 if (dst->sa.sa_family == AF_INET) {
 360                         if (m->m_len < sizeof (struct ip) &&
 361                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 362                                 error = ENOBUFS;
 363                                 goto bad;
 364                         }
 365                         ip = mtod(m, struct ip *);
 366                         /* Honor system-wide control of how to handle IP_DF */
 367                         switch (ip4_ipsec_dfbit) {
 368                         case 0:                 /* clear in outer header */
 369                         case 1:                 /* set in outer header */
 370                                 setdf = ip4_ipsec_dfbit;
 371                                 break;
 372                         default:                /* propagate to outer header */
 373                                 setdf = ntohs(ip->ip_off & IP_DF);
 374                                 break;
 375                         }
 376                 } else {
 377                         ip = NULL;              /* keep compiler happy */
 378                         setdf = 0;
 379                 }
 380                 /* Do the appropriate encapsulation, if necessary */
 381                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 382                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 383 #if 0
 384                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 385                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 386 #endif
 387                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 388                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 389                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 390                         struct mbuf *mp;
 391
 392                         /* Fix IPv4 header checksum and length */
 393                         if (m->m_len < sizeof (struct ip) &&
 394                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 395                                 error = ENOBUFS;
 396                                 goto bad;
 397                         }
 398                         ip = mtod(m, struct ip *);
 399                         ip->ip_len = htons(m->m_pkthdr.len);
 400                         ip->ip_sum = 0;
 401 #ifdef _IP_VHL
 402                         if (ip->ip_vhl == IP_VHL_BORING)
 403                                 ip->ip_sum = in_cksum_hdr(ip);
 404                         else
 405                                 ip->ip_sum = in_cksum(m,
 406                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 407 #else
 408                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 409 #endif
 410
 411                         /* Encapsulate the packet */
 412                         error = ipip_output(m, isr, &mp, 0, 0);
 413                         if (mp == NULL && !error) {
 414                                 /* Should never happen. */
 415                                 DPRINTF(("ipsec4_process_packet: ipip_output "
 416                                         "returns no mbuf and no error!"));
 417                                 error = EFAULT;
 418                         }
 419                         if (error) {
 420                                 if (mp)
 421                                         m_freem(mp);
 422                                 goto bad;
 423                         }
 424                         m = mp, mp = NULL;
 425                         /*
 426                          * ipip_output clears IP_DF in the new header.  If
 427                          * we need to propagate IP_DF from the outer header,
 428                          * then we have to do it here.
 429                          *
 430                          * XXX shouldn't assume what ipip_output does.
 431                          */
 432                         if (dst->sa.sa_family == AF_INET && setdf) {
 433                                 if (m->m_len < sizeof (struct ip) &&
 434                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 435                                         error = ENOBUFS;
 436                                         goto bad;
 437                                 }
 438                                 ip = mtod(m, struct ip *);
 439                                 ip->ip_off = ntohs(ip->ip_off);
 440                                 ip->ip_off |= IP_DF;
 441                                 ip->ip_off = htons(ip->ip_off);
 442                         }
 443                 }
 444         }
 445
 446         /*
 447          * Dispatch to the appropriate IPsec transform logic.  The
 448          * packet will be returned for transmission after crypto
 449          * processing, etc. are completed.  For encapsulation we
 450          * bypass this call because of the explicit call done above
 451          * (necessary to deal with IP_DF handling for IPv4).
 452          *
 453          * NB: m & sav are ``passed to caller'' who's reponsible for
 454          *     for reclaiming their resources.
 455          */
 456         if (sav->tdb_xform->xf_type != XF_IP4) {
 457                 ip = mtod(m, struct ip *);
 458                 i = ip->ip_hl << 2;
 459                 off = offsetof(struct ip, ip_p);
 460                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 461         } else {
 462                 error = ipsec_process_done(m, isr);
 463         }
 464         crit_exit();
 465         return error;
 466 bad:
 467         crit_exit();
 468         if (m)
 469                 m_freem(m);
 470         return error;
 471 }
 472 #endif
 473
 474 #ifdef INET6
 475 /*
 476  * Chop IP6 header from the payload.
 477  */
 478 static struct mbuf *
 479 ipsec6_splithdr(struct mbuf *m)
 480 {
 481         struct mbuf *mh;
 482         struct ip6_hdr *ip6;
 483         int hlen;
 484
 485         KASSERT(m->m_len >= sizeof (struct ip6_hdr),
 486                 ("ipsec6_splithdr: first mbuf too short, len %u", m->m_len));
 487         ip6 = mtod(m, struct ip6_hdr *);
 488         hlen = sizeof(struct ip6_hdr);
 489         if (m->m_len > hlen) {
 490                 MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
 491                 if (!mh) {
 492                         m_freem(m);
 493                         return NULL;
 494                 }
 495                 M_MOVE_PKTHDR(mh, m);
 496                 MH_ALIGN(mh, hlen);
 497                 m->m_len -= hlen;
 498                 m->m_data += hlen;
 499                 mh->m_next = m;
 500                 m = mh;
 501                 m->m_len = hlen;
 502                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 503         } else if (m->m_len < hlen) {
 504                 m = m_pullup(m, hlen);
 505                 if (!m)
 506                         return NULL;
 507         }
 508         return m;
 509 }
 510
 511 /*
 512  * IPsec output logic for IPv6, transport mode.
 513  */
 514 int
 515 ipsec6_output_trans(
 516         struct ipsec_output_state *state,
 517         u_char *nexthdrp,
 518         struct mbuf *mprev,
 519         struct secpolicy *sp,
 520         int flags,
 521         int *tun)
 522 {
 523         struct ipsecrequest *isr;
 524         struct secasindex saidx;
 525         int error = 0;
 526         struct mbuf *m;
 527
 528         KASSERT(state != NULL, ("ipsec6_output: null state"));
 529         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 530         KASSERT(nexthdrp != NULL, ("ipsec6_output: null nexthdrp"));
 531         KASSERT(mprev != NULL, ("ipsec6_output: null mprev"));
 532         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 533         KASSERT(tun != NULL, ("ipsec6_output: null tun"));
 534
 535         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 536                 kprintf("ipsec6_output_trans: applyed SP\n");
 537                 kdebug_secpolicy(sp));
 538
 539         isr = sp->req;
 540         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 541                 /* the rest will be handled by ipsec6_output_tunnel() */
 542                 *tun = 1;               /* need tunnel-mode processing */
 543                 return 0;
 544         }
 545
 546         *tun = 0;
 547         m = state->m;
 548
 549         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 550         if (isr == NULL) {
 551 #ifdef notdef
 552                 /* XXX should notification be done for all errors ? */
 553                 /*
 554                  * Notify the fact that the packet is discarded
 555                  * to ourselves. I believe this is better than
 556                  * just silently discarding. (jinmei@kame.net)
 557                  * XXX: should we restrict the error to TCP packets?
 558                  * XXX: should we directly notify sockets via
 559                  *      kpfctlinputs?
 560                  */
 561                 icmp6_error(m, ICMP6_DST_UNREACH,
 562                             ICMP6_DST_UNREACH_ADMIN, 0);
 563                 m = NULL;       /* NB: icmp6_error frees mbuf */
 564 #endif
 565                 goto bad;
 566         }
 567
 568         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 569                 sizeof (struct ip6_hdr),
 570                 offsetof(struct ip6_hdr, ip6_nxt));
 571 bad:
 572         if (m)
 573                 m_freem(m);
 574         state->m = NULL;
 575         return error;
 576 }
 577
 578 static int
 579 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 580 {
 581         struct ip6_hdr *oip6;
 582         struct ip6_hdr *ip6;
 583         size_t plen;
 584
 585         /* can't tunnel between different AFs */
 586         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 587             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 588                 m_freem(m);
 589                 return EINVAL;
 590         }
 591         KASSERT(m->m_len != sizeof (struct ip6_hdr),
 592                 ("ipsec6_encapsulate: mbuf wrong size; len %u", m->m_len));
 593
 594
 595         /*
 596          * grow the mbuf to accomodate the new IPv6 header.
 597          */
 598         plen = m->m_pkthdr.len;
 599         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 600                 struct mbuf *n;
 601                 MGET(n, MB_DONTWAIT, MT_DATA);
 602                 if (!n) {
 603                         m_freem(m);
 604                         return ENOBUFS;
 605                 }
 606                 n->m_len = sizeof(struct ip6_hdr);
 607                 n->m_next = m->m_next;
 608                 m->m_next = n;
 609                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 610                 oip6 = mtod(n, struct ip6_hdr *);
 611         } else {
 612                 m->m_next->m_len += sizeof(struct ip6_hdr);
 613                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 614                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 615                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 616         }
 617         ip6 = mtod(m, struct ip6_hdr *);
 618         ovbcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 619
 620         /* Fake link-local scope-class addresses */
 621         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 622                 oip6->ip6_src.s6_addr16[1] = 0;
 623         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 624                 oip6->ip6_dst.s6_addr16[1] = 0;
 625
 626         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 627         /* ECN consideration. */
 628         ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 629         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 630                 ip6->ip6_plen = htons(plen);
 631         else {
 632                 /* ip6->ip6_plen will be updated in ip6_output() */
 633         }
 634         ip6->ip6_nxt = IPPROTO_IPV6;
 635         sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
 636         sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
 637         ip6->ip6_hlim = IPV6_DEFHLIM;
 638
 639         /* XXX Should ip6_src be updated later ? */
 640
 641         return 0;
 642 }
 643
 644 /*
 645  * IPsec output logic for IPv6, tunnel mode.
 646  */
 647 int
 648 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 649 {
 650         struct ip6_hdr *ip6;
 651         struct ipsecrequest *isr;
 652         struct secasindex saidx;
 653         int error;
 654         struct sockaddr_in6* dst6;
 655         struct mbuf *m;
 656
 657         KASSERT(state != NULL, ("ipsec6_output: null state"));
 658         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 659         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 660
 661         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 662                 kprintf("ipsec6_output_tunnel: applyed SP\n");
 663                 kdebug_secpolicy(sp));
 664
 665         m = state->m;
 666         /*
 667          * transport mode ipsec (before the 1st tunnel mode) is already
 668          * processed by ipsec6_output_trans().
 669          */
 670         for (isr = sp->req; isr; isr = isr->next) {
 671                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 672                         break;
 673         }
 674         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 675         if (isr == NULL)
 676                 goto bad;
 677
 678         /*
 679          * There may be the case that SA status will be changed when
 680          * we are refering to one. So calling splsoftnet().
 681          */
 682         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 683                 /*
 684                  * build IPsec tunnel.
 685                  */
 686                 /* XXX should be processed with other familiy */
 687                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 688                         ipseclog((LOG_ERR, "ipsec6_output_tunnel: "
 689                             "family mismatched between inner and outer, spi=%u\n",
 690                             ntohl(isr->sav->spi)));
 691                         newipsecstat.ips_out_inval++;
 692                         error = EAFNOSUPPORT;
 693                         goto bad;
 694                 }
 695
 696                 m = ipsec6_splithdr(m);
 697                 if (!m) {
 698                         newipsecstat.ips_out_nomem++;
 699                         error = ENOMEM;
 700                         goto bad;
 701                 }
 702                 error = ipsec6_encapsulate(m, isr->sav);
 703                 if (error) {
 704                         m = NULL;
 705                         goto bad;
 706                 }
 707                 ip6 = mtod(m, struct ip6_hdr *);
 708
 709                 state->ro = &isr->sav->sah->sa_route;
 710                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 711                 dst6 = (struct sockaddr_in6 *)state->dst;
 712                 if (state->ro->ro_rt
 713                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 714                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 715                         RTFREE(state->ro->ro_rt);
 716                         state->ro->ro_rt = NULL;
 717                 }
 718                 if (state->ro->ro_rt == 0) {
 719                         bzero(dst6, sizeof(*dst6));
 720                         dst6->sin6_family = AF_INET6;
 721                         dst6->sin6_len = sizeof(*dst6);
 722                         dst6->sin6_addr = ip6->ip6_dst;
 723                         rtalloc(state->ro);
 724                 }
 725                 if (state->ro->ro_rt == 0) {
 726                         ip6stat.ip6s_noroute++;
 727                         newipsecstat.ips_out_noroute++;
 728                         error = EHOSTUNREACH;
 729                         goto bad;
 730                 }
 731
 732                 /* adjust state->dst if tunnel endpoint is offlink */
 733                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
 734                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 735                         dst6 = (struct sockaddr_in6 *)state->dst;
 736                 }
 737         }
 738
 739         m = ipsec6_splithdr(m);
 740         if (!m) {
 741                 newipsecstat.ips_out_nomem++;
 742                 error = ENOMEM;
 743                 goto bad;
 744         }
 745         ip6 = mtod(m, struct ip6_hdr *);
 746         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 747                 sizeof (struct ip6_hdr),
 748                 offsetof(struct ip6_hdr, ip6_nxt));
 749 bad:
 750         if (m)
 751                 m_freem(m);
 752         state->m = NULL;
 753         return error;
 754 }
 755 #endif /*INET6*/