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  */
  28
  29 /*
  30  * IPsec output processing.
  31  */
  32 #include "opt_inet.h"
  33 #include "opt_inet6.h"
  34 #include "opt_ipsec.h"
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/domain.h>
  40 #include <sys/protosw.h>
  41 #include <sys/socket.h>
  42 #include <sys/errno.h>
  43 #include <sys/syslog.h>
  44 #include <sys/in_cksum.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 <netproto/ipsec/ipsec.h>
  69 #ifdef INET6
  70 #include <netproto/ipsec/ipsec6.h>
  71 #endif
  72 #include <netproto/ipsec/ah_var.h>
  73 #include <netproto/ipsec/esp_var.h>
  74 #include <netproto/ipsec/ipcomp_var.h>
  75
  76 #include <netproto/ipsec/xform.h>
  77
  78 #include <netproto/ipsec/key.h>
  79 #include <netproto/ipsec/keydb.h>
  80 #include <netproto/ipsec/key_debug.h>
  81
  82 int
  83 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
  84 {
  85         struct tdb_ident *tdbi;
  86         struct m_tag *mtag;
  87         struct secasvar *sav;
  88         struct secasindex *saidx;
  89         int error;
  90
  91         KASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
  92         KASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
  93         sav = isr->sav;
  94         KASSERT(sav != NULL, ("ipsec_process_done: null SA"));
  95         KASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH"));
  96
  97         saidx = &sav->sah->saidx;
  98         switch (saidx->dst.sa.sa_family) {
  99 #ifdef INET
 100         case AF_INET:
 101                 /* Fix the header length, for AH processing. */
 102                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 103                 break;
 104 #endif /* INET */
 105 #ifdef INET6
 106         case AF_INET6:
 107                 /* Fix the header length, for AH processing. */
 108                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
 109                         error = ENXIO;
 110                         goto bad;
 111                 }
 112                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
 113                         /* No jumbogram support. */
 114                         error = ENXIO;  /*?*/
 115                         goto bad;
 116                 }
 117                 mtod(m, struct ip6_hdr *)->ip6_plen =
 118                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 119                 break;
 120 #endif /* INET6 */
 121         default:
 122                 DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
 123                     saidx->dst.sa.sa_family));
 124                 error = ENXIO;
 125                 goto bad;
 126         }
 127
 128         /*
 129          * Add a record of what we've done or what needs to be done to the
 130          * packet.
 131          */
 132         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
 133                          sizeof(struct tdb_ident), M_NOWAIT);
 134         if (mtag == NULL) {
 135                 DPRINTF(("ipsec_process_done: could not get packet tag\n"));
 136                 error = ENOMEM;
 137                 goto bad;
 138         }
 139
 140         tdbi = (struct tdb_ident *)m_tag_data(mtag);
 141         tdbi->dst = saidx->dst;
 142         tdbi->proto = saidx->proto;
 143         tdbi->spi = sav->spi;
 144         m_tag_prepend(m, mtag);
 145
 146         /*
 147          * If there's another (bundled) SA to apply, do so.
 148          * Note that this puts a burden on the kernel stack size.
 149          * If this is a problem we'll need to introduce a queue
 150          * to set the packet on so we can unwind the stack before
 151          * doing further processing.
 152          */
 153         if (isr->next) {
 154                 newipsecstat.ips_out_bundlesa++;
 155                 return ipsec4_process_packet(m, isr->next, 0, 0);
 156         }
 157
 158         /*
 159          * We're done with IPsec processing, transmit the packet using the
 160          * appropriate network protocol (IP or IPv6). SPD lookup will be
 161          * performed again there.
 162          */
 163         switch (saidx->dst.sa.sa_family) {
 164 #ifdef INET
 165         struct ip *ip;
 166         case AF_INET:
 167                 ip = mtod(m, struct ip *);
 168                 ip->ip_len = ntohs(ip->ip_len);
 169                 ip->ip_off = ntohs(ip->ip_off);
 170
 171                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 172 #endif /* INET */
 173 #ifdef INET6
 174         case AF_INET6:
 175                 /*
 176                  * We don't need massage, IPv6 header fields are always in
 177                  * net endian.
 178                  */
 179                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 180 #endif /* INET6 */
 181         }
 182         panic("ipsec_process_done");
 183 bad:
 184         m_freem(m);
 185         KEY_FREESAV(&sav);
 186         return (error);
 187 }
 188
 189 static struct ipsecrequest *
 190 ipsec_nextisr(
 191         struct mbuf *m,
 192         struct ipsecrequest *isr,
 193         int af,
 194         struct secasindex *saidx,
 195         int *error
 196 )
 197 {
 198 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
 199                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
 200         struct secasvar *sav;
 201
 202         KASSERT(af == AF_INET || af == AF_INET6,
 203                 ("ipsec_nextisr: invalid address family %u", af));
 204 again:
 205         /*
 206          * Craft SA index to search for proper SA.  Note that
 207          * we only fillin unspecified SA peers for transport
 208          * mode; for tunnel mode they must already be filled in.
 209          */
 210         *saidx = isr->saidx;
 211         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 212                 /* Fillin unspecified SA peers only for transport mode */
 213                 if (af == AF_INET) {
 214                         struct sockaddr_in *sin;
 215                         struct ip *ip = mtod(m, struct ip *);
 216
 217                         if (saidx->src.sa.sa_len == 0) {
 218                                 sin = &saidx->src.sin;
 219                                 sin->sin_len = sizeof(*sin);
 220                                 sin->sin_family = AF_INET;
 221                                 sin->sin_port = IPSEC_PORT_ANY;
 222                                 sin->sin_addr = ip->ip_src;
 223                         }
 224                         if (saidx->dst.sa.sa_len == 0) {
 225                                 sin = &saidx->dst.sin;
 226                                 sin->sin_len = sizeof(*sin);
 227                                 sin->sin_family = AF_INET;
 228                                 sin->sin_port = IPSEC_PORT_ANY;
 229                                 sin->sin_addr = ip->ip_dst;
 230                         }
 231                 } else {
 232                         struct sockaddr_in6 *sin6;
 233                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 234
 235                         if (saidx->src.sin6.sin6_len == 0) {
 236                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 237                                 sin6->sin6_len = sizeof(*sin6);
 238                                 sin6->sin6_family = AF_INET6;
 239                                 sin6->sin6_port = IPSEC_PORT_ANY;
 240                                 sin6->sin6_addr = ip6->ip6_src;
 241                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 242                                         /* fix scope id for comparing SPD */
 243                                         sin6->sin6_addr.s6_addr16[1] = 0;
 244                                         sin6->sin6_scope_id =
 245                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 246                                 }
 247                         }
 248                         if (saidx->dst.sin6.sin6_len == 0) {
 249                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 250                                 sin6->sin6_len = sizeof(*sin6);
 251                                 sin6->sin6_family = AF_INET6;
 252                                 sin6->sin6_port = IPSEC_PORT_ANY;
 253                                 sin6->sin6_addr = ip6->ip6_dst;
 254                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 255                                         /* fix scope id for comparing SPD */
 256                                         sin6->sin6_addr.s6_addr16[1] = 0;
 257                                         sin6->sin6_scope_id =
 258                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 259                                 }
 260                         }
 261                 }
 262         }
 263
 264         /*
 265          * Lookup SA and validate it.
 266          */
 267         *error = key_checkrequest(isr, saidx);
 268         if (*error != 0) {
 269                 /*
 270                  * IPsec processing is required, but no SA found.
 271                  * I assume that key_acquire() had been called
 272                  * to get/establish the SA. Here I discard
 273                  * this packet because it is responsibility for
 274                  * upper layer to retransmit the packet.
 275                  */
 276                 newipsecstat.ips_out_nosa++;
 277                 goto bad;
 278         }
 279         sav = isr->sav;
 280         if (sav == NULL) {              /* XXX valid return */
 281                 KASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 282                         ("ipsec_nextisr: no SA found, but required; level %u",
 283                         ipsec_get_reqlevel(isr)));
 284                 isr = isr->next;
 285                 if (isr == NULL) {
 286                         /*XXXstatistic??*/
 287                         *error = EINVAL;                /*XXX*/
 288                         return isr;
 289                 }
 290                 goto again;
 291         }
 292
 293         /*
 294          * Check system global policy controls.
 295          */
 296         if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
 297             (isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
 298             (isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
 299                 DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
 300                         " to policy (check your sysctls)\n"));
 301                 IPSEC_OSTAT(espstat.esps_pdrops, ahstat.ahs_pdrops,
 302                     ipcompstat.ipcomps_pdrops);
 303                 *error = EHOSTUNREACH;
 304                 goto bad;
 305         }
 306
 307         /*
 308          * Sanity check the SA contents for the caller
 309          * before they invoke the xform output method.
 310          */
 311         if (sav->tdb_xform == NULL) {
 312                 DPRINTF(("ipsec_nextisr: no transform for SA\n"));
 313                 IPSEC_OSTAT(espstat.esps_noxform, ahstat.ahs_noxform,
 314                     ipcompstat.ipcomps_noxform);
 315                 *error = EHOSTUNREACH;
 316                 goto bad;
 317         }
 318         return isr;
 319 bad:
 320         KASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
 321         return NULL;
 322 #undef IPSEC_OSTAT
 323 }
 324
 325 #ifdef INET
 326 /*
 327  * IPsec output logic for IPv4.
 328  */
 329 int
 330 ipsec4_process_packet(
 331         struct mbuf *m,
 332         struct ipsecrequest *isr,
 333         int flags,
 334         int tunalready)
 335 {
 336         struct secasindex saidx;
 337         struct secasvar *sav;
 338         struct ip *ip;
 339         int error, i, off;
 340
 341         KASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
 342         KASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
 343
 344         crit_enter();
 345
 346         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 347         if (isr == NULL)
 348                 goto bad;
 349
 350         sav = isr->sav;
 351         if (!tunalready) {
 352                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 353                 int setdf;
 354
 355                 /*
 356                  * Collect IP_DF state from the outer header.
 357                  */
 358                 if (dst->sa.sa_family == AF_INET) {
 359                         if (m->m_len < sizeof (struct ip) &&
 360                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 361                                 error = ENOBUFS;
 362                                 goto bad;
 363                         }
 364                         ip = mtod(m, struct ip *);
 365                         /* Honor system-wide control of how to handle IP_DF */
 366                         switch (ip4_ipsec_dfbit) {
 367                         case 0:                 /* clear in outer header */
 368                         case 1:                 /* set in outer header */
 369                                 setdf = ip4_ipsec_dfbit;
 370                                 break;
 371                         default:                /* propagate to outer header */
 372                                 setdf = ntohs(ip->ip_off & IP_DF);
 373                                 break;
 374                         }
 375                 } else {
 376                         ip = NULL;              /* keep compiler happy */
 377                         setdf = 0;
 378                 }
 379                 /* Do the appropriate encapsulation, if necessary */
 380                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 381                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 382 #if 0
 383                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 384                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 385 #endif
 386                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 387                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 388                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 389                         struct mbuf *mp;
 390
 391                         /* Fix IPv4 header checksum and length */
 392                         if (m->m_len < sizeof (struct ip) &&
 393                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 394                                 error = ENOBUFS;
 395                                 goto bad;
 396                         }
 397                         ip = mtod(m, struct ip *);
 398                         ip->ip_len = htons(m->m_pkthdr.len);
 399                         ip->ip_sum = 0;
 400 #ifdef _IP_VHL
 401                         if (ip->ip_vhl == IP_VHL_BORING)
 402                                 ip->ip_sum = in_cksum_hdr(ip);
 403                         else
 404                                 ip->ip_sum = in_cksum(m,
 405                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 406 #else
 407                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 408 #endif
 409
 410                         /* Encapsulate the packet */
 411                         error = ipip_output(m, isr, &mp, 0, 0);
 412                         if (mp == NULL && !error) {
 413                                 /* Should never happen. */
 414                                 DPRINTF(("ipsec4_process_packet: ipip_output "
 415                                         "returns no mbuf and no error!"));
 416                                 error = EFAULT;
 417                         }
 418                         if (error) {
 419                                 if (mp)
 420                                         m_freem(mp);
 421                                 goto bad;
 422                         }
 423                         m = mp, mp = NULL;
 424                         /*
 425                          * ipip_output clears IP_DF in the new header.  If
 426                          * we need to propagate IP_DF from the outer header,
 427                          * then we have to do it here.
 428                          *
 429                          * XXX shouldn't assume what ipip_output does.
 430                          */
 431                         if (dst->sa.sa_family == AF_INET && setdf) {
 432                                 if (m->m_len < sizeof (struct ip) &&
 433                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 434                                         error = ENOBUFS;
 435                                         goto bad;
 436                                 }
 437                                 ip = mtod(m, struct ip *);
 438                                 ip->ip_off = ntohs(ip->ip_off);
 439                                 ip->ip_off |= IP_DF;
 440                                 ip->ip_off = htons(ip->ip_off);
 441                         }
 442                 }
 443         }
 444
 445         /*
 446          * Dispatch to the appropriate IPsec transform logic.  The
 447          * packet will be returned for transmission after crypto
 448          * processing, etc. are completed.  For encapsulation we
 449          * bypass this call because of the explicit call done above
 450          * (necessary to deal with IP_DF handling for IPv4).
 451          *
 452          * NB: m & sav are ``passed to caller'' who's reponsible for
 453          *     for reclaiming their resources.
 454          */
 455         if (sav->tdb_xform->xf_type != XF_IP4) {
 456                 ip = mtod(m, struct ip *);
 457                 i = ip->ip_hl << 2;
 458                 off = offsetof(struct ip, ip_p);
 459                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 460         } else {
 461                 error = ipsec_process_done(m, isr);
 462         }
 463         crit_exit();
 464         return error;
 465 bad:
 466         crit_exit();
 467         if (m)
 468                 m_freem(m);
 469         return error;
 470 }
 471 #endif
 472
 473 #ifdef INET6
 474 /*
 475  * Chop IP6 header from the payload.
 476  */
 477 static struct mbuf *
 478 ipsec6_splithdr(struct mbuf *m)
 479 {
 480         struct mbuf *mh;
 481         struct ip6_hdr *ip6;
 482         int hlen;
 483
 484         KASSERT(m->m_len >= sizeof (struct ip6_hdr),
 485                 ("ipsec6_splithdr: first mbuf too short, len %u", m->m_len));
 486         ip6 = mtod(m, struct ip6_hdr *);
 487         hlen = sizeof(struct ip6_hdr);
 488         if (m->m_len > hlen) {
 489                 MGETHDR(mh, M_NOWAIT, MT_HEADER);
 490                 if (!mh) {
 491                         m_freem(m);
 492                         return NULL;
 493                 }
 494                 M_MOVE_PKTHDR(mh, m);
 495                 MH_ALIGN(mh, hlen);
 496                 m->m_len -= hlen;
 497                 m->m_data += hlen;
 498                 mh->m_next = m;
 499                 m = mh;
 500                 m->m_len = hlen;
 501                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 502         } else if (m->m_len < hlen) {
 503                 m = m_pullup(m, hlen);
 504                 if (!m)
 505                         return NULL;
 506         }
 507         return m;
 508 }
 509
 510 /*
 511  * IPsec output logic for IPv6, transport mode.
 512  */
 513 int
 514 ipsec6_output_trans(
 515         struct ipsec_output_state *state,
 516         u_char *nexthdrp,
 517         struct mbuf *mprev,
 518         struct secpolicy *sp,
 519         int flags,
 520         int *tun)
 521 {
 522         struct ipsecrequest *isr;
 523         struct secasindex saidx;
 524         int error = 0;
 525         struct mbuf *m;
 526
 527         KASSERT(state != NULL, ("ipsec6_output: null state"));
 528         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 529         KASSERT(nexthdrp != NULL, ("ipsec6_output: null nexthdrp"));
 530         KASSERT(mprev != NULL, ("ipsec6_output: null mprev"));
 531         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 532         KASSERT(tun != NULL, ("ipsec6_output: null tun"));
 533
 534         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 535                 kprintf("ipsec6_output_trans: applyed SP\n");
 536                 kdebug_secpolicy(sp));
 537
 538         isr = sp->req;
 539         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 540                 /* the rest will be handled by ipsec6_output_tunnel() */
 541                 *tun = 1;               /* need tunnel-mode processing */
 542                 return 0;
 543         }
 544
 545         *tun = 0;
 546         m = state->m;
 547
 548         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 549         if (isr == NULL) {
 550 #ifdef notdef
 551                 /* XXX should notification be done for all errors ? */
 552                 /*
 553                  * Notify the fact that the packet is discarded
 554                  * to ourselves. I believe this is better than
 555                  * just silently discarding. (jinmei@kame.net)
 556                  * XXX: should we restrict the error to TCP packets?
 557                  * XXX: should we directly notify sockets via
 558                  *      kpfctlinputs?
 559                  */
 560                 icmp6_error(m, ICMP6_DST_UNREACH,
 561                             ICMP6_DST_UNREACH_ADMIN, 0);
 562                 m = NULL;       /* NB: icmp6_error frees mbuf */
 563 #endif
 564                 goto bad;
 565         }
 566
 567         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 568                 sizeof (struct ip6_hdr),
 569                 offsetof(struct ip6_hdr, ip6_nxt));
 570 bad:
 571         if (m)
 572                 m_freem(m);
 573         state->m = NULL;
 574         return error;
 575 }
 576
 577 static int
 578 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 579 {
 580         struct ip6_hdr *oip6;
 581         struct ip6_hdr *ip6;
 582         size_t plen;
 583
 584         /* can't tunnel between different AFs */
 585         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 586             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 587                 m_freem(m);
 588                 return EINVAL;
 589         }
 590         KASSERT(m->m_len != sizeof (struct ip6_hdr),
 591                 ("ipsec6_encapsulate: mbuf wrong size; len %u", m->m_len));
 592
 593
 594         /*
 595          * grow the mbuf to accomodate the new IPv6 header.
 596          */
 597         plen = m->m_pkthdr.len;
 598         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 599                 struct mbuf *n;
 600                 MGET(n, M_NOWAIT, MT_DATA);
 601                 if (!n) {
 602                         m_freem(m);
 603                         return ENOBUFS;
 604                 }
 605                 n->m_len = sizeof(struct ip6_hdr);
 606                 n->m_next = m->m_next;
 607                 m->m_next = n;
 608                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 609                 oip6 = mtod(n, struct ip6_hdr *);
 610         } else {
 611                 m->m_next->m_len += sizeof(struct ip6_hdr);
 612                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 613                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 614                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 615         }
 616         ip6 = mtod(m, struct ip6_hdr *);
 617         ovbcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 618
 619         /* Fake link-local scope-class addresses */
 620         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 621                 oip6->ip6_src.s6_addr16[1] = 0;
 622         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 623                 oip6->ip6_dst.s6_addr16[1] = 0;
 624
 625         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 626         /* ECN consideration. */
 627         ip6_ecn_ingress(ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 628         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 629                 ip6->ip6_plen = htons(plen);
 630         else {
 631                 /* ip6->ip6_plen will be updated in ip6_output() */
 632         }
 633         ip6->ip6_nxt = IPPROTO_IPV6;
 634         sav->sah->saidx.src.sin6.sin6_addr = ip6->ip6_src;
 635         sav->sah->saidx.dst.sin6.sin6_addr = ip6->ip6_dst;
 636         ip6->ip6_hlim = IPV6_DEFHLIM;
 637
 638         /* XXX Should ip6_src be updated later ? */
 639
 640         return 0;
 641 }
 642
 643 /*
 644  * IPsec output logic for IPv6, tunnel mode.
 645  */
 646 int
 647 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 648 {
 649         struct ip6_hdr *ip6;
 650         struct ipsecrequest *isr;
 651         struct secasindex saidx;
 652         int error;
 653         struct sockaddr_in6* dst6;
 654         struct mbuf *m;
 655
 656         KASSERT(state != NULL, ("ipsec6_output: null state"));
 657         KASSERT(state->m != NULL, ("ipsec6_output: null m"));
 658         KASSERT(sp != NULL, ("ipsec6_output: null sp"));
 659
 660         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 661                 kprintf("ipsec6_output_tunnel: applyed SP\n");
 662                 kdebug_secpolicy(sp));
 663
 664         m = state->m;
 665         /*
 666          * transport mode ipsec (before the 1st tunnel mode) is already
 667          * processed by ipsec6_output_trans().
 668          */
 669         for (isr = sp->req; isr; isr = isr->next) {
 670                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 671                         break;
 672         }
 673         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 674         if (isr == NULL)
 675                 goto bad;
 676
 677         /*
 678          * There may be the case that SA status will be changed when
 679          * we are refering to one. So calling splsoftnet().
 680          */
 681         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 682                 /*
 683                  * build IPsec tunnel.
 684                  */
 685                 /* XXX should be processed with other familiy */
 686                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 687                         ipseclog((LOG_ERR, "ipsec6_output_tunnel: "
 688                             "family mismatched between inner and outer, spi=%u\n",
 689                             ntohl(isr->sav->spi)));
 690                         newipsecstat.ips_out_inval++;
 691                         error = EAFNOSUPPORT;
 692                         goto bad;
 693                 }
 694
 695                 m = ipsec6_splithdr(m);
 696                 if (!m) {
 697                         newipsecstat.ips_out_nomem++;
 698                         error = ENOMEM;
 699                         goto bad;
 700                 }
 701                 error = ipsec6_encapsulate(m, isr->sav);
 702                 if (error) {
 703                         m = NULL;
 704                         goto bad;
 705                 }
 706                 ip6 = mtod(m, struct ip6_hdr *);
 707
 708                 state->ro = &isr->sav->sah->sa_route;
 709                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 710                 dst6 = (struct sockaddr_in6 *)state->dst;
 711                 if (state->ro->ro_rt
 712                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 713                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 714                         RTFREE(state->ro->ro_rt);
 715                         state->ro->ro_rt = NULL;
 716                 }
 717                 if (state->ro->ro_rt == 0) {
 718                         bzero(dst6, sizeof(*dst6));
 719                         dst6->sin6_family = AF_INET6;
 720                         dst6->sin6_len = sizeof(*dst6);
 721                         dst6->sin6_addr = ip6->ip6_dst;
 722                         rtalloc(state->ro);
 723                 }
 724                 if (state->ro->ro_rt == 0) {
 725                         ip6stat.ip6s_noroute++;
 726                         newipsecstat.ips_out_noroute++;
 727                         error = EHOSTUNREACH;
 728                         goto bad;
 729                 }
 730
 731                 /* adjust state->dst if tunnel endpoint is offlink */
 732                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY) {
 733                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 734                         dst6 = (struct sockaddr_in6 *)state->dst;
 735                 }
 736         }
 737
 738         m = ipsec6_splithdr(m);
 739         if (!m) {
 740                 newipsecstat.ips_out_nomem++;
 741                 error = ENOMEM;
 742                 goto bad;
 743         }
 744         ip6 = mtod(m, struct ip6_hdr *);
 745         return (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 746                 sizeof (struct ip6_hdr),
 747                 offsetof(struct ip6_hdr, ip6_nxt));
 748 bad:
 749         if (m)
 750                 m_freem(m);
 751         state->m = NULL;
 752         return error;
 753 }
 754 #endif /*INET6*/