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 1.2 2003/06/17 04:28:53 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
  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         SPLASSERT(net, "ipsec_process_done");
  94
  95         KASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
  96         KASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
  97         sav = isr->sav;
  98         KASSERT(sav != NULL, ("ipsec_process_done: null SA"));
  99         KASSERT(sav->sah != NULL, ("ipsec_process_done: 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(("ipsec_process_done: unknown protocol family %u\n",
 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(("ipsec_process_done: could not get packet tag\n"));
 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
 162         /*
 163          * We're done with IPsec processing, transmit the packet using the
 164          * appropriate network protocol (IP or IPv6). SPD lookup will be
 165          * performed again there.
 166          */
 167         switch (saidx->dst.sa.sa_family) {
 168 #ifdef INET
 169         struct ip *ip;
 170         case AF_INET:
 171                 ip = mtod(m, struct ip *);
 172                 ip->ip_len = ntohs(ip->ip_len);
 173                 ip->ip_off = ntohs(ip->ip_off);
 174
 175                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 176 #endif /* INET */
 177 #ifdef INET6
 178         case AF_INET6:
 179                 /*
 180                  * We don't need massage, IPv6 header fields are always in
 181                  * net endian.
 182                  */
 183                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 184 #endif /* INET6 */
 185         }
 186         panic("ipsec_process_done");
 187 bad:
 188         m_freem(m);
 189         KEY_FREESAV(&sav);
 190         return (error);
 191 }
 192
 193 static struct ipsecrequest *
 194 ipsec_nextisr(
 195         struct mbuf *m,
 196         struct ipsecrequest *isr,
 197         int af,
 198         struct secasindex *saidx,
 199         int *error
 200 )
 201 {
 202 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
 203                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
 204         struct secasvar *sav;
 205
 206         SPLASSERT(net, "ipsec_nextisr");
 207         KASSERT(af == AF_INET || af == AF_INET6,
 208                 ("ipsec_nextisr: invalid address family %u", af));
 209 again:
 210         /*
 211          * Craft SA index to search for proper SA.  Note that
 212          * we only fillin unspecified SA peers for transport
 213          * mode; for tunnel mode they must already be filled in.
 214          */
 215         *saidx = isr->saidx;
 216         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 217                 /* Fillin unspecified SA peers only for transport mode */
 218                 if (af == AF_INET) {
 219                         struct sockaddr_in *sin;
 220                         struct ip *ip = mtod(m, struct ip *);
 221
 222                         if (saidx->src.sa.sa_len == 0) {
 223                                 sin = &saidx->src.sin;
 224                                 sin->sin_len = sizeof(*sin);
 225                                 sin->sin_family = AF_INET;
 226                                 sin->sin_port = IPSEC_PORT_ANY;
 227                                 sin->sin_addr = ip->ip_src;
 228                         }
 229                         if (saidx->dst.sa.sa_len == 0) {
 230                                 sin = &saidx->dst.sin;
 231                                 sin->sin_len = sizeof(*sin);
 232                                 sin->sin_family = AF_INET;
 233                                 sin->sin_port = IPSEC_PORT_ANY;
 234                                 sin->sin_addr = ip->ip_dst;
 235                         }
 236                 } else {
 237                         struct sockaddr_in6 *sin6;
 238                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 239
 240                         if (saidx->src.sin6.sin6_len == 0) {
 241                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 242                                 sin6->sin6_len = sizeof(*sin6);
 243                                 sin6->sin6_family = AF_INET6;
 244                                 sin6->sin6_port = IPSEC_PORT_ANY;
 245                                 sin6->sin6_addr = ip6->ip6_src;
 246                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 247                                         /* fix scope id for comparing SPD */
 248                                         sin6->sin6_addr.s6_addr16[1] = 0;
 249                                         sin6->sin6_scope_id =
 250                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 251                                 }
 252                         }
 253                         if (saidx->dst.sin6.sin6_len == 0) {
 254                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 255                                 sin6->sin6_len = sizeof(*sin6);
 256                                 sin6->sin6_family = AF_INET6;
 257                                 sin6->sin6_port = IPSEC_PORT_ANY;
 258                                 sin6->sin6_addr = ip6->ip6_dst;
 259                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 260                                         /* fix scope id for comparing SPD */
 261                                         sin6->sin6_addr.s6_addr16[1] = 0;
 262                                         sin6->sin6_scope_id =
 263                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 264                                 }
 265                         }
 266                 }
 267         }
 268
 269         /*
 270          * Lookup SA and validate it.
 271          */
 272         *error = key_checkrequest(isr, saidx);
 273         if (*error != 0) {
 274                 /*
 275                  * IPsec processing is required, but no SA found.
 276                  * I assume that key_acquire() had been called
 277                  * to get/establish the SA. Here I discard
 278                  * this packet because it is responsibility for
 279                  * upper layer to retransmit the packet.
 280                  */
 281                 newipsecstat.ips_out_nosa++;
 282                 goto bad;
 283         }
 284         sav = isr->sav;
 285         if (sav == NULL) {              /* XXX valid return */
 286                 KASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 287                         ("ipsec_nextisr: no SA found, but required; level %u",
 288                         ipsec_get_reqlevel(isr)));
 289                 isr = isr->next;
 290                 if (isr == NULL) {
 291                         /*XXXstatistic??*/
 292                         *error = EINVAL;                /*XXX*/
 293                         return isr;
 294                 }
 295                 goto again;
 296         }
 297
 298         /*
 299          * Check system global policy controls.
 300          */
 301         if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
 302             (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
 303             (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
 304                 DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
 305                         " to policy (check your sysctls)\n"));
 306                 IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
 307                     ipcompstat.ipcomps_pdrops);
 308                 *error = EHOSTUNREACH;
 309                 goto bad;
 310         }
 311
 312         /*
 313          * Sanity check the SA contents for the caller
 314          * before they invoke the xform output method.
 315          */
 316         if (sav->tdb_xform == NULL) {
 317                 DPRINTF(("ipsec_nextisr: no transform for SA\n"));
 318                 IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
 319                     ipcompstat.ipcomps_noxform);
 320                 *error = EHOSTUNREACH;
 321                 goto bad;
 322         }
 323         return isr;
 324 bad:
 325         KASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
 326         return NULL;
 327 #undef IPSEC_OSTAT
 328 }
 329
 330 #ifdef INET
 331 /*
 332  * IPsec output logic for IPv4.
 333  */
 334 int
 335 ipsec4_process_packet(
 336         struct mbuf *m,
 337         struct ipsecrequest *isr,
 338         int flags,
 339         int tunalready)
 340 {
 341         struct secasindex saidx;
 342         struct secasvar *sav;
 343         struct ip *ip;
 344         int s, error, i, off;
 345
 346         KASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
 347         KASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
 348
 349         s = splnet();                   /* insure SA contents don't change */
 350
 351         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 352         if (isr == NULL)
 353                 goto bad;
 354
 355         sav = isr->sav;
 356         if (!tunalready) {
 357                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 358                 int setdf;
 359
 360                 /*
 361                  * Collect IP_DF state from the outer header.
 362                  */
 363                 if (dst->sa.sa_family == AF_INET) {
 364                         if (m->m_len < sizeof (struct ip) &&
 365                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 366                                 error = ENOBUFS;
 367                                 goto bad;
 368                         }
 369                         ip = mtod(m, struct ip *);
 370                         /* Honor system-wide control of how to handle IP_DF */
 371                         switch (ip4_ipsec_dfbit) {
 372                         case 0:                 /* clear in outer header */
 373                         case 1:                 /* set in outer header */
 374                                 setdf = ip4_ipsec_dfbit;
 375                                 break;
 376                         default:                /* propagate to outer header */
 377                                 setdf = ntohs(ip->ip_off & IP_DF);
 378                                 break;
 379                         }
 380                 } else {
 381                         ip = NULL;              /* keep compiler happy */
 382                         setdf = 0;
 383                 }
 384                 /* Do the appropriate encapsulation, if necessary */
 385                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 386                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 387 #if 0
 388                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 389                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 390 #endif
 391                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 392                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 393                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 394                         struct mbuf *mp;
 395
 396                         /* Fix IPv4 header checksum and length */
 397                         if (m->m_len < sizeof (struct ip) &&
 398                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 399                                 error = ENOBUFS;
 400                                 goto bad;
 401                         }
 402                         ip = mtod(m, struct ip *);
 403                         ip->ip_len = htons(m->m_pkthdr.len);
 404                         ip->ip_sum = 0;
 405 #ifdef _IP_VHL
 406                         if (ip->ip_vhl == IP_VHL_BORING)
 407                                 ip->ip_sum = in_cksum_hdr(ip);
 408                         else
 409                                 ip->ip_sum = in_cksum(m,
 410                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 411 #else
 412                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 413 #endif
 414
 415                         /* Encapsulate the packet */
 416                         error = ipip_output(m, isr, &mp, 0, 0);
 417                         if (mp == NULL && !error) {
 418                                 /* Should never happen. */
 419                                 DPRINTF(("ipsec4_process_packet: ipip_output "
 420                                         "returns no mbuf and no error!"));
 421                                 error = EFAULT;
 422                         }
 423                         if (error) {
 424                                 if (mp)
 425                                         m_freem(mp);
 426                                 goto bad;
 427                         }
 428                         m = mp, mp = NULL;
 429                         /*
 430                          * ipip_output clears IP_DF in the new header.  If
 431                          * we need to propagate IP_DF from the outer header,
 432                          * then we have to do it here.
 433                          *
 434                          * XXX shouldn't assume what ipip_output does.
 435                          */
 436                         if (dst->sa.sa_family == AF_INET && setdf) {
 437                                 if (m->m_len < sizeof (struct ip) &&
 438                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 439                                         error = ENOBUFS;
 440                                         goto bad;
 441                                 }
 442                                 ip = mtod(m, struct ip *);
 443                                 ip->ip_off = ntohs(ip->ip_off);
 444                                 ip->ip_off |= IP_DF;
 445                                 ip->ip_off = htons(ip->ip_off);
 446                         }
 447                 }
 448         }
 449
 450         /*
 451          * Dispatch to the appropriate IPsec transform logic.  The
 452          * packet will be returned for transmission after crypto
 453          * processing, etc. are completed.  For encapsulation we
 454          * bypass this call because of the explicit call done above
 455          * (necessary to deal with IP_DF handling for IPv4).
 456          *
 457          * NB: m & sav are ``passed to caller'' who's reponsible for
 458          *     for reclaiming their resources.
 459          */
 460         if (sav->tdb_xform->xf_type != XF_IP4) {
 461                 ip = mtod(m, struct ip *);
 462                 i = ip->ip_hl << 2;
 463                 off = offsetof(struct ip, ip_p);
 464                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 465         } else {
 466                 error = ipsec_process_done(m, isr);
 467         }
 468         splx(s);
 469         return error;
 470 bad:
 471         splx(s);
 472         if (m)
 473                 m_freem(m);
 474         return error;
 475 }
 476 #endif
 477
 478 #ifdef INET6
 479 /*
 480  * Chop IP6 header from the payload.
 481  */
 482 static struct mbuf *
 483 ipsec6_splithdr(struct mbuf *m)
 484 {
 485         struct mbuf *mh;
 486         struct ip6_hdr *ip6;
 487         int hlen;
 488
 489         KASSERT(m->m_len >= sizeof (struct ip6_hdr),
 490                 ("ipsec6_splithdr: first mbuf too short, len %u", m->m_len));
 491         ip6 = mtod(m, struct ip6_hdr *);
 492         hlen = sizeof(struct ip6_hdr);
 493         if (m->m_len > hlen) {
 494                 MGETHDR(mh, M_DONTWAIT, MT_HEADER);
 495                 if (!mh) {
 496                         m_freem(m);
 497                         return NULL;
 498                 }
 499                 M_MOVE_PKTHDR(mh, m);
 500                 MH_ALIGN(mh, hlen);
 501                 m->m_len -= hlen;
 502                 m->m_data += hlen;
 503                 mh->m_next = m;
 504                 m = mh;
 505                 m->m_len = hlen;
 506                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 507         } else if (m->m_len < hlen) {
 508                 m = m_pullup(m, hlen);
 509                 if (!m)
 510                         return NULL;
 511         }
 512         return m;
 513 }
 514
 515 /*
 516  * IPsec output logic for IPv6, transport mode.
 517  */
 518 int
 519 ipsec6_output_trans(
 520         struct ipsec_output_state *state,
 521         u_char *nexthdrp,
 522         struct mbuf *mprev,
 523         struct secpolicy *sp,
 524         int flags,
 525         int *tun)
 526 {
 527         struct ipsecrequest *isr;
 528         struct secasindex saidx;
 529         int error = 0;
 530         struct mbuf *m;
 531
 532         KASSERT(state != NULL, ("ipsec6_output: null state"));
 533         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 534         KASSERT(nexthdrp != NULL, ("ipsec6_output: null nexthdrp"));
 535         KASSERT(mprev != NULL, ("ipsec6_output: null mprev"));
 536         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 537         KASSERT(tun != NULL, ("ipsec6_output: null tun"));
 538
 539         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 540                 printf("ipsec6_output_trans: applyed SP\n");
 541                 kdebug_secpolicy(sp));
 542
 543         isr = sp->req;
 544         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 545                 /* the rest will be handled by ipsec6_output_tunnel() */
 546                 *tun = 1;               /* need tunnel-mode processing */
 547                 return 0;
 548         }
 549
 550         *tun = 0;
 551         m = state->m;
 552
 553         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 554         if (isr == NULL) {
 555 #ifdef notdef
 556                 /* XXX should notification be done for all errors ? */
 557                 /*
 558                  * Notify the fact that the packet is discarded
 559                  * to ourselves. I believe this is better than
 560                  * just silently discarding. (jinmei@kame.net)
 561                  * XXX: should we restrict the error to TCP packets?
 562                  * XXX: should we directly notify sockets via
 563                  *      pfctlinputs?
 564                  */
 565                 icmp6_error(m, ICMP6_DST_UNREACH,
 566                             ICMP6_DST_UNREACH_ADMIN, 0);
 567                 m = NULL;       /* NB: icmp6_error frees mbuf */
 568 #endif
 569                 goto bad;
 570         }
 571
 572         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 573                 sizeof (struct ip6_hdr),
 574                 offsetof(struct ip6_hdr, ip6_nxt));
 575 bad:
 576         if (m)
 577                 m_freem(m);
 578         state->m = NULL;
 579         return error;
 580 }
 581
 582 static int
 583 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 584 {
 585         struct ip6_hdr *oip6;
 586         struct ip6_hdr *ip6;
 587         size_t plen;
 588
 589         /* can't tunnel between different AFs */
 590         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 591             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 592                 m_freem(m);
 593                 return EINVAL;
 594         }
 595         KASSERT(m->m_len != sizeof (struct ip6_hdr),
 596                 ("ipsec6_encapsulate: mbuf wrong size; len %u", m->m_len));
 597
 598
 599         /*
 600          * grow the mbuf to accomodate the new IPv6 header.
 601          */
 602         plen = m->m_pkthdr.len;
 603         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 604                 struct mbuf *n;
 605                 MGET(n, M_DONTWAIT, MT_DATA);
 606                 if (!n) {
 607                         m_freem(m);
 608                         return ENOBUFS;
 609                 }
 610                 n->m_len = sizeof(struct ip6_hdr);
 611                 n->m_next = m->m_next;
 612                 m->m_next = n;
 613                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 614                 oip6 = mtod(n, struct ip6_hdr *);
 615         } else {
 616                 m->m_next->m_len += sizeof(struct ip6_hdr);
 617                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 618                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 619                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 620         }
 621         ip6 = mtod(m, struct ip6_hdr *);
 622         ovbcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 623
 624         /* Fake link-local scope-class addresses */
 625         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 626                 oip6->ip6_src.s6_addr16[1] = 0;
 627         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 628                 oip6->ip6_dst.s6_addr16[1] = 0;
 629
 630         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 631         /* ECN consideration. */
 632         ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 633         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 634                 ip6->ip6_plen = htons(plen);
 635         else {
 636                 /* ip6->ip6_plen will be updated in ip6_output() */
 637         }
 638         ip6->ip6_nxt = IPPROTO_IPV6;
 639         sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
 640         sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
 641         ip6->ip6_hlim = IPV6_DEFHLIM;
 642
 643         /* XXX Should ip6_src be updated later ? */
 644
 645         return 0;
 646 }
 647
 648 /*
 649  * IPsec output logic for IPv6, tunnel mode.
 650  */
 651 int
 652 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 653 {
 654         struct ip6_hdr *ip6;
 655         struct ipsecrequest *isr;
 656         struct secasindex saidx;
 657         int error;
 658         struct sockaddr_in6* dst6;
 659         struct mbuf *m;
 660
 661         KASSERT(state != NULL, ("ipsec6_output: null state"));
 662         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 663         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 664
 665         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 666                 printf("ipsec6_output_tunnel: applyed SP\n");
 667                 kdebug_secpolicy(sp));
 668
 669         m = state->m;
 670         /*
 671          * transport mode ipsec (before the 1st tunnel mode) is already
 672          * processed by ipsec6_output_trans().
 673          */
 674         for (isr = sp->req; isr; isr = isr->next) {
 675                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 676                         break;
 677         }
 678         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 679         if (isr == NULL)
 680                 goto bad;
 681
 682         /*
 683          * There may be the case that SA status will be changed when
 684          * we are refering to one. So calling splsoftnet().
 685          */
 686         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 687                 /*
 688                  * build IPsec tunnel.
 689                  */
 690                 /* XXX should be processed with other familiy */
 691                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 692                         ipseclog((LOG_ERR, "ipsec6_output_tunnel: "
 693                             "family mismatched between inner and outer, spi=%lu\n",
 694                             ntohl(isr->sav->spi)));
 695                         newipsecstat.ips_out_inval++;
 696                         error = EAFNOSUPPORT;
 697                         goto bad;
 698                 }
 699
 700                 m = ipsec6_splithdr(m);
 701                 if (!m) {
 702                         newipsecstat.ips_out_nomem++;
 703                         error = ENOMEM;
 704                         goto bad;
 705                 }
 706                 error = ipsec6_encapsulate(m, isr->sav);
 707                 if (error) {
 708                         m = NULL;
 709                         goto bad;
 710                 }
 711                 ip6 = mtod(m, struct ip6_hdr *);
 712
 713                 state->ro = &isr->sav->sah->sa_route;
 714                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 715                 dst6 = (struct sockaddr_in6 *)state->dst;
 716                 if (state->ro->ro_rt
 717                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 718                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 719                         RTFREE(state->ro->ro_rt);
 720                         state->ro->ro_rt = NULL;
 721                 }
 722                 if (state->ro->ro_rt == 0) {
 723                         bzero(dst6, sizeof(*dst6));
 724                         dst6->sin6_family = AF_INET6;
 725                         dst6->sin6_len = sizeof(*dst6);
 726                         dst6->sin6_addr = ip6->ip6_dst;
 727                         rtalloc(state->ro);
 728                 }
 729                 if (state->ro->ro_rt == 0) {
 730                         ip6stat.ip6s_noroute++;
 731                         newipsecstat.ips_out_noroute++;
 732                         error = EHOSTUNREACH;
 733                         goto bad;
 734                 }
 735
 736                 /* adjust state->dst if tunnel endpoint is offlink */
 737                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
 738                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 739                         dst6 = (struct sockaddr_in6 *)state->dst;
 740                 }
 741         }
 742
 743         m = ipsec6_splithdr(m);
 744         if (!m) {
 745                 newipsecstat.ips_out_nomem++;
 746                 error = ENOMEM;
 747                 goto bad;
 748         }
 749         ip6 = mtod(m, struct ip6_hdr *);
 750         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 751                 sizeof (struct ip6_hdr),
 752                 offsetof(struct ip6_hdr, ip6_nxt));
 753 bad:
 754         if (m)
 755                 m_freem(m);
 756         state->m = NULL;
 757         return error;
 758 }
 759 #endif /*INET6*/