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 1.6 2004/10/15 22:59:10 hsu 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         SPLASSERT(net, "ipsec_process_done");
  93
  94         KASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
  95         KASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
  96         sav = isr->sav;
  97         KASSERT(sav != NULL, ("ipsec_process_done: null SA"));
  98         KASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH"));
  99
 100         saidx = &sav->sah->saidx;
 101         switch (saidx->dst.sa.sa_family) {
 102 #ifdef INET
 103         case AF_INET:
 104                 /* Fix the header length, for AH processing. */
 105                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 106                 break;
 107 #endif /* INET */
 108 #ifdef INET6
 109         case AF_INET6:
 110                 /* Fix the header length, for AH processing. */
 111                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
 112                         error = ENXIO;
 113                         goto bad;
 114                 }
 115                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
 116                         /* No jumbogram support. */
 117                         error = ENXIO;  /*?*/
 118                         goto bad;
 119                 }
 120                 mtod(m, struct ip6_hdr *)->ip6_plen =
 121                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 122                 break;
 123 #endif /* INET6 */
 124         default:
 125                 DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
 126                     saidx->dst.sa.sa_family));
 127                 error = ENXIO;
 128                 goto bad;
 129         }
 130
 131         /*
 132          * Add a record of what we've done or what needs to be done to the
 133          * packet.
 134          */
 135         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
 136                         sizeof(struct tdb_ident), M_NOWAIT);
 137         if (mtag == NULL) {
 138                 DPRINTF(("ipsec_process_done: could not get packet tag\n"));
 139                 error = ENOMEM;
 140                 goto bad;
 141         }
 142
 143         tdbi = (struct tdb_ident *)(mtag + 1);
 144         tdbi->dst = saidx->dst;
 145         tdbi->proto = saidx->proto;
 146         tdbi->spi = sav->spi;
 147         m_tag_prepend(m, mtag);
 148
 149         /*
 150          * If there's another (bundled) SA to apply, do so.
 151          * Note that this puts a burden on the kernel stack size.
 152          * If this is a problem we'll need to introduce a queue
 153          * to set the packet on so we can unwind the stack before
 154          * doing further processing.
 155          */
 156         if (isr->next) {
 157                 newipsecstat.ips_out_bundlesa++;
 158                 return ipsec4_process_packet(m, isr->next, 0, 0);
 159         }
 160
 161         /*
 162          * We're done with IPsec processing, transmit the packet using the
 163          * appropriate network protocol (IP or IPv6). SPD lookup will be
 164          * performed again there.
 165          */
 166         switch (saidx->dst.sa.sa_family) {
 167 #ifdef INET
 168         struct ip *ip;
 169         case AF_INET:
 170                 ip = mtod(m, struct ip *);
 171                 ip->ip_len = ntohs(ip->ip_len);
 172                 ip->ip_off = ntohs(ip->ip_off);
 173
 174                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 175 #endif /* INET */
 176 #ifdef INET6
 177         case AF_INET6:
 178                 /*
 179                  * We don't need massage, IPv6 header fields are always in
 180                  * net endian.
 181                  */
 182                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 183 #endif /* INET6 */
 184         }
 185         panic("ipsec_process_done");
 186 bad:
 187         m_freem(m);
 188         KEY_FREESAV(&sav);
 189         return (error);
 190 }
 191
 192 static struct ipsecrequest *
 193 ipsec_nextisr(
 194         struct mbuf *m,
 195         struct ipsecrequest *isr,
 196         int af,
 197         struct secasindex *saidx,
 198         int *error
 199 )
 200 {
 201 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
 202                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
 203         struct secasvar *sav;
 204
 205         SPLASSERT(net, "ipsec_nextisr");
 206         KASSERT(af == AF_INET || af == AF_INET6,
 207                 ("ipsec_nextisr: invalid address family %u", af));
 208 again:
 209         /*
 210          * Craft SA index to search for proper SA.  Note that
 211          * we only fillin unspecified SA peers for transport
 212          * mode; for tunnel mode they must already be filled in.
 213          */
 214         *saidx = isr->saidx;
 215         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 216                 /* Fillin unspecified SA peers only for transport mode */
 217                 if (af == AF_INET) {
 218                         struct sockaddr_in *sin;
 219                         struct ip *ip = mtod(m, struct ip *);
 220
 221                         if (saidx->src.sa.sa_len == 0) {
 222                                 sin = &saidx->src.sin;
 223                                 sin->sin_len = sizeof(*sin);
 224                                 sin->sin_family = AF_INET;
 225                                 sin->sin_port = IPSEC_PORT_ANY;
 226                                 sin->sin_addr = ip->ip_src;
 227                         }
 228                         if (saidx->dst.sa.sa_len == 0) {
 229                                 sin = &saidx->dst.sin;
 230                                 sin->sin_len = sizeof(*sin);
 231                                 sin->sin_family = AF_INET;
 232                                 sin->sin_port = IPSEC_PORT_ANY;
 233                                 sin->sin_addr = ip->ip_dst;
 234                         }
 235                 } else {
 236                         struct sockaddr_in6 *sin6;
 237                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 238
 239                         if (saidx->src.sin6.sin6_len == 0) {
 240                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 241                                 sin6->sin6_len = sizeof(*sin6);
 242                                 sin6->sin6_family = AF_INET6;
 243                                 sin6->sin6_port = IPSEC_PORT_ANY;
 244                                 sin6->sin6_addr = ip6->ip6_src;
 245                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 246                                         /* fix scope id for comparing SPD */
 247                                         sin6->sin6_addr.s6_addr16[1] = 0;
 248                                         sin6->sin6_scope_id =
 249                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 250                                 }
 251                         }
 252                         if (saidx->dst.sin6.sin6_len == 0) {
 253                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 254                                 sin6->sin6_len = sizeof(*sin6);
 255                                 sin6->sin6_family = AF_INET6;
 256                                 sin6->sin6_port = IPSEC_PORT_ANY;
 257                                 sin6->sin6_addr = ip6->ip6_dst;
 258                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 259                                         /* fix scope id for comparing SPD */
 260                                         sin6->sin6_addr.s6_addr16[1] = 0;
 261                                         sin6->sin6_scope_id =
 262                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 263                                 }
 264                         }
 265                 }
 266         }
 267
 268         /*
 269          * Lookup SA and validate it.
 270          */
 271         *error = key_checkrequest(isr, saidx);
 272         if (*error != 0) {
 273                 /*
 274                  * IPsec processing is required, but no SA found.
 275                  * I assume that key_acquire() had been called
 276                  * to get/establish the SA. Here I discard
 277                  * this packet because it is responsibility for
 278                  * upper layer to retransmit the packet.
 279                  */
 280                 newipsecstat.ips_out_nosa++;
 281                 goto bad;
 282         }
 283         sav = isr->sav;
 284         if (sav == NULL) {              /* XXX valid return */
 285                 KASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 286                         ("ipsec_nextisr: no SA found, but required; level %u",
 287                         ipsec_get_reqlevel(isr)));
 288                 isr = isr->next;
 289                 if (isr == NULL) {
 290                         /*XXXstatistic??*/
 291                         *error = EINVAL;                /*XXX*/
 292                         return isr;
 293                 }
 294                 goto again;
 295         }
 296
 297         /*
 298          * Check system global policy controls.
 299          */
 300         if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
 301             (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
 302             (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
 303                 DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
 304                         " to policy (check your sysctls)\n"));
 305                 IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
 306                     ipcompstat.ipcomps_pdrops);
 307                 *error = EHOSTUNREACH;
 308                 goto bad;
 309         }
 310
 311         /*
 312          * Sanity check the SA contents for the caller
 313          * before they invoke the xform output method.
 314          */
 315         if (sav->tdb_xform == NULL) {
 316                 DPRINTF(("ipsec_nextisr: no transform for SA\n"));
 317                 IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
 318                     ipcompstat.ipcomps_noxform);
 319                 *error = EHOSTUNREACH;
 320                 goto bad;
 321         }
 322         return isr;
 323 bad:
 324         KASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
 325         return NULL;
 326 #undef IPSEC_OSTAT
 327 }
 328
 329 #ifdef INET
 330 /*
 331  * IPsec output logic for IPv4.
 332  */
 333 int
 334 ipsec4_process_packet(
 335         struct mbuf *m,
 336         struct ipsecrequest *isr,
 337         int flags,
 338         int tunalready)
 339 {
 340         struct secasindex saidx;
 341         struct secasvar *sav;
 342         struct ip *ip;
 343         int s, error, i, off;
 344
 345         KASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
 346         KASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
 347
 348         s = splnet();                   /* insure SA contents don't change */
 349
 350         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 351         if (isr == NULL)
 352                 goto bad;
 353
 354         sav = isr->sav;
 355         if (!tunalready) {
 356                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 357                 int setdf;
 358
 359                 /*
 360                  * Collect IP_DF state from the outer header.
 361                  */
 362                 if (dst->sa.sa_family == AF_INET) {
 363                         if (m->m_len < sizeof (struct ip) &&
 364                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 365                                 error = ENOBUFS;
 366                                 goto bad;
 367                         }
 368                         ip = mtod(m, struct ip *);
 369                         /* Honor system-wide control of how to handle IP_DF */
 370                         switch (ip4_ipsec_dfbit) {
 371                         case 0:                 /* clear in outer header */
 372                         case 1:                 /* set in outer header */
 373                                 setdf = ip4_ipsec_dfbit;
 374                                 break;
 375                         default:                /* propagate to outer header */
 376                                 setdf = ntohs(ip->ip_off & IP_DF);
 377                                 break;
 378                         }
 379                 } else {
 380                         ip = NULL;              /* keep compiler happy */
 381                         setdf = 0;
 382                 }
 383                 /* Do the appropriate encapsulation, if necessary */
 384                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 385                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 386 #if 0
 387                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 388                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 389 #endif
 390                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 391                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 392                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 393                         struct mbuf *mp;
 394
 395                         /* Fix IPv4 header checksum and length */
 396                         if (m->m_len < sizeof (struct ip) &&
 397                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 398                                 error = ENOBUFS;
 399                                 goto bad;
 400                         }
 401                         ip = mtod(m, struct ip *);
 402                         ip->ip_len = htons(m->m_pkthdr.len);
 403                         ip->ip_sum = 0;
 404 #ifdef _IP_VHL
 405                         if (ip->ip_vhl == IP_VHL_BORING)
 406                                 ip->ip_sum = in_cksum_hdr(ip);
 407                         else
 408                                 ip->ip_sum = in_cksum(m,
 409                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 410 #else
 411                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 412 #endif
 413
 414                         /* Encapsulate the packet */
 415                         error = ipip_output(m, isr, &mp, 0, 0);
 416                         if (mp == NULL && !error) {
 417                                 /* Should never happen. */
 418                                 DPRINTF(("ipsec4_process_packet: ipip_output "
 419                                         "returns no mbuf and no error!"));
 420                                 error = EFAULT;
 421                         }
 422                         if (error) {
 423                                 if (mp)
 424                                         m_freem(mp);
 425                                 goto bad;
 426                         }
 427                         m = mp, mp = NULL;
 428                         /*
 429                          * ipip_output clears IP_DF in the new header.  If
 430                          * we need to propagate IP_DF from the outer header,
 431                          * then we have to do it here.
 432                          *
 433                          * XXX shouldn't assume what ipip_output does.
 434                          */
 435                         if (dst->sa.sa_family == AF_INET && setdf) {
 436                                 if (m->m_len < sizeof (struct ip) &&
 437                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 438                                         error = ENOBUFS;
 439                                         goto bad;
 440                                 }
 441                                 ip = mtod(m, struct ip *);
 442                                 ip->ip_off = ntohs(ip->ip_off);
 443                                 ip->ip_off |= IP_DF;
 444                                 ip->ip_off = htons(ip->ip_off);
 445                         }
 446                 }
 447         }
 448
 449         /*
 450          * Dispatch to the appropriate IPsec transform logic.  The
 451          * packet will be returned for transmission after crypto
 452          * processing, etc. are completed.  For encapsulation we
 453          * bypass this call because of the explicit call done above
 454          * (necessary to deal with IP_DF handling for IPv4).
 455          *
 456          * NB: m & sav are ``passed to caller'' who's reponsible for
 457          *     for reclaiming their resources.
 458          */
 459         if (sav->tdb_xform->xf_type != XF_IP4) {
 460                 ip = mtod(m, struct ip *);
 461                 i = ip->ip_hl << 2;
 462                 off = offsetof(struct ip, ip_p);
 463                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 464         } else {
 465                 error = ipsec_process_done(m, isr);
 466         }
 467         splx(s);
 468         return error;
 469 bad:
 470         splx(s);
 471         if (m)
 472                 m_freem(m);
 473         return error;
 474 }
 475 #endif
 476
 477 #ifdef INET6
 478 /*
 479  * Chop IP6 header from the payload.
 480  */
 481 static struct mbuf *
 482 ipsec6_splithdr(struct mbuf *m)
 483 {
 484         struct mbuf *mh;
 485         struct ip6_hdr *ip6;
 486         int hlen;
 487
 488         KASSERT(m->m_len >= sizeof (struct ip6_hdr),
 489                 ("ipsec6_splithdr: first mbuf too short, len %u", m->m_len));
 490         ip6 = mtod(m, struct ip6_hdr *);
 491         hlen = sizeof(struct ip6_hdr);
 492         if (m->m_len > hlen) {
 493                 MGETHDR(mh, MB_DONTWAIT, MT_HEADER);
 494                 if (!mh) {
 495                         m_freem(m);
 496                         return NULL;
 497                 }
 498                 M_MOVE_PKTHDR(mh, m);
 499                 MH_ALIGN(mh, hlen);
 500                 m->m_len -= hlen;
 501                 m->m_data += hlen;
 502                 mh->m_next = m;
 503                 m = mh;
 504                 m->m_len = hlen;
 505                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 506         } else if (m->m_len < hlen) {
 507                 m = m_pullup(m, hlen);
 508                 if (!m)
 509                         return NULL;
 510         }
 511         return m;
 512 }
 513
 514 /*
 515  * IPsec output logic for IPv6, transport mode.
 516  */
 517 int
 518 ipsec6_output_trans(
 519         struct ipsec_output_state *state,
 520         u_char *nexthdrp,
 521         struct mbuf *mprev,
 522         struct secpolicy *sp,
 523         int flags,
 524         int *tun)
 525 {
 526         struct ipsecrequest *isr;
 527         struct secasindex saidx;
 528         int error = 0;
 529         struct mbuf *m;
 530
 531         KASSERT(state != NULL, ("ipsec6_output: null state"));
 532         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 533         KASSERT(nexthdrp != NULL, ("ipsec6_output: null nexthdrp"));
 534         KASSERT(mprev != NULL, ("ipsec6_output: null mprev"));
 535         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 536         KASSERT(tun != NULL, ("ipsec6_output: null tun"));
 537
 538         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 539                 printf("ipsec6_output_trans: applyed SP\n");
 540                 kdebug_secpolicy(sp));
 541
 542         isr = sp->req;
 543         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 544                 /* the rest will be handled by ipsec6_output_tunnel() */
 545                 *tun = 1;               /* need tunnel-mode processing */
 546                 return 0;
 547         }
 548
 549         *tun = 0;
 550         m = state->m;
 551
 552         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 553         if (isr == NULL) {
 554 #ifdef notdef
 555                 /* XXX should notification be done for all errors ? */
 556                 /*
 557                  * Notify the fact that the packet is discarded
 558                  * to ourselves. I believe this is better than
 559                  * just silently discarding. (jinmei@kame.net)
 560                  * XXX: should we restrict the error to TCP packets?
 561                  * XXX: should we directly notify sockets via
 562                  *      pfctlinputs?
 563                  */
 564                 icmp6_error(m, ICMP6_DST_UNREACH,
 565                             ICMP6_DST_UNREACH_ADMIN, 0);
 566                 m = NULL;       /* NB: icmp6_error frees mbuf */
 567 #endif
 568                 goto bad;
 569         }
 570
 571         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 572                 sizeof (struct ip6_hdr),
 573                 offsetof(struct ip6_hdr, ip6_nxt));
 574 bad:
 575         if (m)
 576                 m_freem(m);
 577         state->m = NULL;
 578         return error;
 579 }
 580
 581 static int
 582 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 583 {
 584         struct ip6_hdr *oip6;
 585         struct ip6_hdr *ip6;
 586         size_t plen;
 587
 588         /* can't tunnel between different AFs */
 589         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 590             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 591                 m_freem(m);
 592                 return EINVAL;
 593         }
 594         KASSERT(m->m_len != sizeof (struct ip6_hdr),
 595                 ("ipsec6_encapsulate: mbuf wrong size; len %u", m->m_len));
 596
 597
 598         /*
 599          * grow the mbuf to accomodate the new IPv6 header.
 600          */
 601         plen = m->m_pkthdr.len;
 602         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 603                 struct mbuf *n;
 604                 MGET(n, MB_DONTWAIT, MT_DATA);
 605                 if (!n) {
 606                         m_freem(m);
 607                         return ENOBUFS;
 608                 }
 609                 n->m_len = sizeof(struct ip6_hdr);
 610                 n->m_next = m->m_next;
 611                 m->m_next = n;
 612                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 613                 oip6 = mtod(n, struct ip6_hdr *);
 614         } else {
 615                 m->m_next->m_len += sizeof(struct ip6_hdr);
 616                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 617                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 618                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 619         }
 620         ip6 = mtod(m, struct ip6_hdr *);
 621         ovbcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 622
 623         /* Fake link-local scope-class addresses */
 624         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 625                 oip6->ip6_src.s6_addr16[1] = 0;
 626         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 627                 oip6->ip6_dst.s6_addr16[1] = 0;
 628
 629         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 630         /* ECN consideration. */
 631         ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 632         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 633                 ip6->ip6_plen = htons(plen);
 634         else {
 635                 /* ip6->ip6_plen will be updated in ip6_output() */
 636         }
 637         ip6->ip6_nxt = IPPROTO_IPV6;
 638         sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
 639         sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
 640         ip6->ip6_hlim = IPV6_DEFHLIM;
 641
 642         /* XXX Should ip6_src be updated later ? */
 643
 644         return 0;
 645 }
 646
 647 /*
 648  * IPsec output logic for IPv6, tunnel mode.
 649  */
 650 int
 651 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 652 {
 653         struct ip6_hdr *ip6;
 654         struct ipsecrequest *isr;
 655         struct secasindex saidx;
 656         int error;
 657         struct sockaddr_in6* dst6;
 658         struct mbuf *m;
 659
 660         KASSERT(state != NULL, ("ipsec6_output: null state"));
 661         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 662         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 663
 664         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 665                 printf("ipsec6_output_tunnel: applyed SP\n");
 666                 kdebug_secpolicy(sp));
 667
 668         m = state->m;
 669         /*
 670          * transport mode ipsec (before the 1st tunnel mode) is already
 671          * processed by ipsec6_output_trans().
 672          */
 673         for (isr = sp->req; isr; isr = isr->next) {
 674                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 675                         break;
 676         }
 677         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 678         if (isr == NULL)
 679                 goto bad;
 680
 681         /*
 682          * There may be the case that SA status will be changed when
 683          * we are refering to one. So calling splsoftnet().
 684          */
 685         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 686                 /*
 687                  * build IPsec tunnel.
 688                  */
 689                 /* XXX should be processed with other familiy */
 690                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 691                         ipseclog((LOG_ERR, "ipsec6_output_tunnel: "
 692                             "family mismatched between inner and outer, spi=%u\n",
 693                             ntohl(isr->sav->spi)));
 694                         newipsecstat.ips_out_inval++;
 695                         error = EAFNOSUPPORT;
 696                         goto bad;
 697                 }
 698
 699                 m = ipsec6_splithdr(m);
 700                 if (!m) {
 701                         newipsecstat.ips_out_nomem++;
 702                         error = ENOMEM;
 703                         goto bad;
 704                 }
 705                 error = ipsec6_encapsulate(m, isr->sav);
 706                 if (error) {
 707                         m = NULL;
 708                         goto bad;
 709                 }
 710                 ip6 = mtod(m, struct ip6_hdr *);
 711
 712                 state->ro = &isr->sav->sah->sa_route;
 713                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 714                 dst6 = (struct sockaddr_in6 *)state->dst;
 715                 if (state->ro->ro_rt
 716                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 717                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 718                         RTFREE(state->ro->ro_rt);
 719                         state->ro->ro_rt = NULL;
 720                 }
 721                 if (state->ro->ro_rt == 0) {
 722                         bzero(dst6, sizeof(*dst6));
 723                         dst6->sin6_family = AF_INET6;
 724                         dst6->sin6_len = sizeof(*dst6);
 725                         dst6->sin6_addr = ip6->ip6_dst;
 726                         rtalloc(state->ro);
 727                 }
 728                 if (state->ro->ro_rt == 0) {
 729                         ip6stat.ip6s_noroute++;
 730                         newipsecstat.ips_out_noroute++;
 731                         error = EHOSTUNREACH;
 732                         goto bad;
 733                 }
 734
 735                 /* adjust state->dst if tunnel endpoint is offlink */
 736                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
 737                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 738                         dst6 = (struct sockaddr_in6 *)state->dst;
 739                 }
 740         }
 741
 742         m = ipsec6_splithdr(m);
 743         if (!m) {
 744                 newipsecstat.ips_out_nomem++;
 745                 error = ENOMEM;
 746                 goto bad;
 747         }
 748         ip6 = mtod(m, struct ip6_hdr *);
 749         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 750                 sizeof (struct ip6_hdr),
 751                 offsetof(struct ip6_hdr, ip6_nxt));
 752 bad:
 753         if (m)
 754                 m_freem(m);
 755         state->m = NULL;
 756         return error;
 757 }
 758 #endif /*INET6*/