sys/netipsec/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  * $FreeBSD$
  27  */
  28
  29 /*
  30  * IPsec output processing.
  31  */
  32 #include "opt_inet.h"
  33 #include "opt_inet6.h"
  34 #include "opt_ipsec.h"
  35 #include "opt_enc.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/domain.h>
  41 #include <sys/protosw.h>
  42 #include <sys/socket.h>
  43 #include <sys/errno.h>
  44 #include <sys/syslog.h>
  45
  46 #include <net/if.h>
  47 #include <net/pfil.h>
  48 #include <net/route.h>
  49 #include <net/vnet.h>
  50
  51 #include <netinet/in.h>
  52 #include <netinet/in_systm.h>
  53 #include <netinet/ip.h>
  54 #include <netinet/ip_var.h>
  55 #include <netinet/in_var.h>
  56 #include <netinet/ip_ecn.h>
  57 #ifdef INET6
  58 #include <netinet6/ip6_ecn.h>
  59 #endif
  60
  61 #include <netinet/ip6.h>
  62 #ifdef INET6
  63 #include <netinet6/ip6_var.h>
  64 #endif
  65 #include <netinet/in_pcb.h>
  66 #ifdef INET6
  67 #include <netinet/icmp6.h>
  68 #endif
  69
  70 #include <netipsec/ipsec.h>
  71 #ifdef INET6
  72 #include <netipsec/ipsec6.h>
  73 #endif
  74 #include <netipsec/ah_var.h>
  75 #include <netipsec/esp_var.h>
  76 #include <netipsec/ipcomp_var.h>
  77
  78 #include <netipsec/xform.h>
  79
  80 #include <netipsec/key.h>
  81 #include <netipsec/keydb.h>
  82 #include <netipsec/key_debug.h>
  83
  84 #include <machine/in_cksum.h>
  85
  86 #ifdef IPSEC_NAT_T
  87 #include <netinet/udp.h>
  88 #endif
  89
  90 #ifdef DEV_ENC
  91 #include <net/if_enc.h>
  92 #endif
  93
  94
  95 int
  96 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
  97 {
  98         struct tdb_ident *tdbi;
  99         struct m_tag *mtag;
 100         struct secasvar *sav;
 101         struct secasindex *saidx;
 102         int error;
 103
 104         IPSEC_ASSERT(m != NULL, ("null mbuf"));
 105         IPSEC_ASSERT(isr != NULL, ("null ISR"));
 106         sav = isr->sav;
 107         IPSEC_ASSERT(sav != NULL, ("null SA"));
 108         IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
 109
 110         saidx = &sav->sah->saidx;
 111         switch (saidx->dst.sa.sa_family) {
 112 #ifdef INET
 113         case AF_INET:
 114                 /* Fix the header length, for AH processing. */
 115                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 116                 break;
 117 #endif /* INET */
 118 #ifdef INET6
 119         case AF_INET6:
 120                 /* Fix the header length, for AH processing. */
 121                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
 122                         error = ENXIO;
 123                         goto bad;
 124                 }
 125                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
 126                         /* No jumbogram support. */
 127                         error = ENXIO;  /*?*/
 128                         goto bad;
 129                 }
 130                 mtod(m, struct ip6_hdr *)->ip6_plen =
 131                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 132                 break;
 133 #endif /* INET6 */
 134         default:
 135                 DPRINTF(("%s: unknown protocol family %u\n", __func__,
 136                     saidx->dst.sa.sa_family));
 137                 error = ENXIO;
 138                 goto bad;
 139         }
 140
 141         /*
 142          * Add a record of what we've done or what needs to be done to the
 143          * packet.
 144          */
 145         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
 146                         sizeof(struct tdb_ident), M_NOWAIT);
 147         if (mtag == NULL) {
 148                 DPRINTF(("%s: could not get packet tag\n", __func__));
 149                 error = ENOMEM;
 150                 goto bad;
 151         }
 152
 153         tdbi = (struct tdb_ident *)(mtag + 1);
 154         tdbi->dst = saidx->dst;
 155         tdbi->proto = saidx->proto;
 156         tdbi->spi = sav->spi;
 157         m_tag_prepend(m, mtag);
 158
 159         /*
 160          * If there's another (bundled) SA to apply, do so.
 161          * Note that this puts a burden on the kernel stack size.
 162          * If this is a problem we'll need to introduce a queue
 163          * to set the packet on so we can unwind the stack before
 164          * doing further processing.
 165          */
 166         if (isr->next) {
 167                 V_ipsec4stat.ips_out_bundlesa++;
 168                 sav = isr->next->sav;
 169                 saidx = &sav->sah->saidx;
 170                 switch (saidx->dst.sa.sa_family) {
 171 #ifdef INET
 172                 case AF_INET:
 173                         return ipsec4_process_packet(m, isr->next, 0, 0);
 174                         /* NOTREACHED */
 175 #endif
 176 #ifdef notyet
 177 #ifdef INET6
 178                 case AF_INET6:
 179                         /* XXX */
 180                         ipsec6_output_trans()
 181                         ipsec6_output_tunnel()
 182                         /* NOTREACHED */
 183 #endif /* INET6 */
 184 #endif
 185                 default:
 186                         DPRINTF(("%s: unknown protocol family %u\n", __func__,
 187                             saidx->dst.sa.sa_family));
 188                         error = ENXIO;
 189                         goto bad;
 190                 }
 191         }
 192         key_sa_recordxfer(sav, m);              /* record data transfer */
 193
 194         m_addr_changed(m);
 195
 196         /*
 197          * We're done with IPsec processing, transmit the packet using the
 198          * appropriate network protocol (IP or IPv6). SPD lookup will be
 199          * performed again there.
 200          */
 201         switch (saidx->dst.sa.sa_family) {
 202 #ifdef INET
 203         struct ip *ip;
 204         case AF_INET:
 205                 ip = mtod(m, struct ip *);
 206                 ip->ip_len = ntohs(ip->ip_len);
 207                 ip->ip_off = ntohs(ip->ip_off);
 208
 209 #ifdef IPSEC_NAT_T
 210                 /*
 211                  * If NAT-T is enabled, now that all IPsec processing is done
 212                  * insert UDP encapsulation header after IP header.
 213                  */
 214                 if (sav->natt_type) {
 215 #ifdef _IP_VHL
 216                         const int hlen = IP_VHL_HL(ip->ip_vhl);
 217 #else
 218                         const int hlen = (ip->ip_hl << 2);
 219 #endif
 220                         int size, off;
 221                         struct mbuf *mi;
 222                         struct udphdr *udp;
 223
 224                         size = sizeof(struct udphdr);
 225                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
 226                                 /*
 227                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
 228                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
 229                                  * ignoring possible AH mode
 230                                  * non-IKE marker + non-ESP marker
 231                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
 232                                  */
 233                                 size += sizeof(u_int64_t);
 234                         }
 235                         mi = m_makespace(m, hlen, size, &off);
 236                         if (mi == NULL) {
 237                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
 238                                     __func__));
 239                                 error = ENOBUFS;
 240                                 goto bad;
 241                         }
 242
 243                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
 244                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 245                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
 246                         else
 247                                 udp->uh_sport =
 248                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
 249                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
 250                         udp->uh_sum = 0;
 251                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
 252                         ip->ip_len = m->m_pkthdr.len;
 253                         ip->ip_p = IPPROTO_UDP;
 254
 255                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 256                                 *(u_int64_t *)(udp + 1) = 0;
 257                 }
 258 #endif /* IPSEC_NAT_T */
 259
 260                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 261 #endif /* INET */
 262 #ifdef INET6
 263         case AF_INET6:
 264                 /*
 265                  * We don't need massage, IPv6 header fields are always in
 266                  * net endian.
 267                  */
 268                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 269 #endif /* INET6 */
 270         }
 271         panic("ipsec_process_done");
 272 bad:
 273         m_freem(m);
 274         return (error);
 275 }
 276
 277 static struct ipsecrequest *
 278 ipsec_nextisr(
 279         struct mbuf *m,
 280         struct ipsecrequest *isr,
 281         int af,
 282         struct secasindex *saidx,
 283         int *error
 284 )
 285 {
 286 #define IPSEC_OSTAT(x,y,z) (isr->saidx.proto == IPPROTO_ESP ? (x)++ : \
 287                             isr->saidx.proto == IPPROTO_AH ? (y)++ : (z)++)
 288         struct secasvar *sav;
 289
 290         IPSECREQUEST_LOCK_ASSERT(isr);
 291
 292         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
 293                 ("invalid address family %u", af));
 294 again:
 295         /*
 296          * Craft SA index to search for proper SA.  Note that
 297          * we only fillin unspecified SA peers for transport
 298          * mode; for tunnel mode they must already be filled in.
 299          */
 300         *saidx = isr->saidx;
 301         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 302                 /* Fillin unspecified SA peers only for transport mode */
 303                 if (af == AF_INET) {
 304                         struct sockaddr_in *sin;
 305                         struct ip *ip = mtod(m, struct ip *);
 306
 307                         if (saidx->src.sa.sa_len == 0) {
 308                                 sin = &saidx->src.sin;
 309                                 sin->sin_len = sizeof(*sin);
 310                                 sin->sin_family = AF_INET;
 311                                 sin->sin_port = IPSEC_PORT_ANY;
 312                                 sin->sin_addr = ip->ip_src;
 313                         }
 314                         if (saidx->dst.sa.sa_len == 0) {
 315                                 sin = &saidx->dst.sin;
 316                                 sin->sin_len = sizeof(*sin);
 317                                 sin->sin_family = AF_INET;
 318                                 sin->sin_port = IPSEC_PORT_ANY;
 319                                 sin->sin_addr = ip->ip_dst;
 320                         }
 321                 } else {
 322                         struct sockaddr_in6 *sin6;
 323                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 324
 325                         if (saidx->src.sin6.sin6_len == 0) {
 326                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 327                                 sin6->sin6_len = sizeof(*sin6);
 328                                 sin6->sin6_family = AF_INET6;
 329                                 sin6->sin6_port = IPSEC_PORT_ANY;
 330                                 sin6->sin6_addr = ip6->ip6_src;
 331                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 332                                         /* fix scope id for comparing SPD */
 333                                         sin6->sin6_addr.s6_addr16[1] = 0;
 334                                         sin6->sin6_scope_id =
 335                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 336                                 }
 337                         }
 338                         if (saidx->dst.sin6.sin6_len == 0) {
 339                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 340                                 sin6->sin6_len = sizeof(*sin6);
 341                                 sin6->sin6_family = AF_INET6;
 342                                 sin6->sin6_port = IPSEC_PORT_ANY;
 343                                 sin6->sin6_addr = ip6->ip6_dst;
 344                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 345                                         /* fix scope id for comparing SPD */
 346                                         sin6->sin6_addr.s6_addr16[1] = 0;
 347                                         sin6->sin6_scope_id =
 348                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 349                                 }
 350                         }
 351                 }
 352         }
 353
 354         /*
 355          * Lookup SA and validate it.
 356          */
 357         *error = key_checkrequest(isr, saidx);
 358         if (*error != 0) {
 359                 /*
 360                  * IPsec processing is required, but no SA found.
 361                  * I assume that key_acquire() had been called
 362                  * to get/establish the SA. Here I discard
 363                  * this packet because it is responsibility for
 364                  * upper layer to retransmit the packet.
 365                  */
 366                 V_ipsec4stat.ips_out_nosa++;
 367                 goto bad;
 368         }
 369         sav = isr->sav;
 370         if (sav == NULL) {
 371                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 372                         ("no SA found, but required; level %u",
 373                         ipsec_get_reqlevel(isr)));
 374                 IPSECREQUEST_UNLOCK(isr);
 375                 isr = isr->next;
 376                 /*
 377                  * If isr is NULL, we found a 'use' policy w/o SA.
 378                  * Return w/o error and w/o isr so we can drop out
 379                  * and continue w/o IPsec processing.
 380                  */
 381                 if (isr == NULL)
 382                         return isr;
 383                 IPSECREQUEST_LOCK(isr);
 384                 goto again;
 385         }
 386
 387         /*
 388          * Check system global policy controls.
 389          */
 390         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
 391             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
 392             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
 393                 DPRINTF(("%s: IPsec outbound packet dropped due"
 394                         " to policy (check your sysctls)\n", __func__));
 395                 IPSEC_OSTAT(V_espstat.esps_pdrops, V_ahstat.ahs_pdrops,
 396                     V_ipcompstat.ipcomps_pdrops);
 397                 *error = EHOSTUNREACH;
 398                 goto bad;
 399         }
 400
 401         /*
 402          * Sanity check the SA contents for the caller
 403          * before they invoke the xform output method.
 404          */
 405         if (sav->tdb_xform == NULL) {
 406                 DPRINTF(("%s: no transform for SA\n", __func__));
 407                 IPSEC_OSTAT(V_espstat.esps_noxform, V_ahstat.ahs_noxform,
 408                     V_ipcompstat.ipcomps_noxform);
 409                 *error = EHOSTUNREACH;
 410                 goto bad;
 411         }
 412         return isr;
 413 bad:
 414         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
 415         IPSECREQUEST_UNLOCK(isr);
 416         return NULL;
 417 #undef IPSEC_OSTAT
 418 }
 419
 420 #ifdef INET
 421 /*
 422  * IPsec output logic for IPv4.
 423  */
 424 int
 425 ipsec4_process_packet(
 426         struct mbuf *m,
 427         struct ipsecrequest *isr,
 428         int flags,
 429         int tunalready)
 430 {
 431         struct secasindex saidx;
 432         struct secasvar *sav;
 433         struct ip *ip;
 434         int error, i, off;
 435
 436         IPSEC_ASSERT(m != NULL, ("null mbuf"));
 437         IPSEC_ASSERT(isr != NULL, ("null isr"));
 438
 439         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 440
 441         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 442         if (isr == NULL) {
 443                 if (error != 0)
 444                         goto bad;
 445                 return EJUSTRETURN;
 446         }
 447
 448         sav = isr->sav;
 449
 450 #ifdef DEV_ENC
 451         encif->if_opackets++;
 452         encif->if_obytes += m->m_pkthdr.len;
 453
 454         /* pass the mbuf to enc0 for bpf processing */
 455         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
 456         /* pass the mbuf to enc0 for packet filtering */
 457         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 458                 goto bad;
 459 #endif
 460
 461         if (!tunalready) {
 462                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 463                 int setdf;
 464
 465                 /*
 466                  * Collect IP_DF state from the outer header.
 467                  */
 468                 if (dst->sa.sa_family == AF_INET) {
 469                         if (m->m_len < sizeof (struct ip) &&
 470                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 471                                 error = ENOBUFS;
 472                                 goto bad;
 473                         }
 474                         ip = mtod(m, struct ip *);
 475                         /* Honor system-wide control of how to handle IP_DF */
 476                         switch (V_ip4_ipsec_dfbit) {
 477                         case 0:                 /* clear in outer header */
 478                         case 1:                 /* set in outer header */
 479                                 setdf = V_ip4_ipsec_dfbit;
 480                                 break;
 481                         default:                /* propagate to outer header */
 482                                 setdf = ntohs(ip->ip_off & IP_DF);
 483                                 break;
 484                         }
 485                 } else {
 486                         ip = NULL;              /* keep compiler happy */
 487                         setdf = 0;
 488                 }
 489                 /* Do the appropriate encapsulation, if necessary */
 490                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 491                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 492 #if 0
 493                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 494                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 495 #endif
 496                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 497                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 498                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 499                         struct mbuf *mp;
 500
 501                         /* Fix IPv4 header checksum and length */
 502                         if (m->m_len < sizeof (struct ip) &&
 503                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 504                                 error = ENOBUFS;
 505                                 goto bad;
 506                         }
 507                         ip = mtod(m, struct ip *);
 508                         ip->ip_len = htons(m->m_pkthdr.len);
 509                         ip->ip_sum = 0;
 510 #ifdef _IP_VHL
 511                         if (ip->ip_vhl == IP_VHL_BORING)
 512                                 ip->ip_sum = in_cksum_hdr(ip);
 513                         else
 514                                 ip->ip_sum = in_cksum(m,
 515                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 516 #else
 517                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 518 #endif
 519
 520                         /* Encapsulate the packet */
 521                         error = ipip_output(m, isr, &mp, 0, 0);
 522                         if (mp == NULL && !error) {
 523                                 /* Should never happen. */
 524                                 DPRINTF(("%s: ipip_output returns no mbuf and "
 525                                         "no error!", __func__));
 526                                 error = EFAULT;
 527                         }
 528                         if (error) {
 529                                 if (mp) {
 530                                         /* XXX: Should never happen! */
 531                                         m_freem(mp);
 532                                 }
 533                                 m = NULL; /* ipip_output() already freed it */
 534                                 goto bad;
 535                         }
 536                         m = mp, mp = NULL;
 537                         /*
 538                          * ipip_output clears IP_DF in the new header.  If
 539                          * we need to propagate IP_DF from the outer header,
 540                          * then we have to do it here.
 541                          *
 542                          * XXX shouldn't assume what ipip_output does.
 543                          */
 544                         if (dst->sa.sa_family == AF_INET && setdf) {
 545                                 if (m->m_len < sizeof (struct ip) &&
 546                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 547                                         error = ENOBUFS;
 548                                         goto bad;
 549                                 }
 550                                 ip = mtod(m, struct ip *);
 551                                 ip->ip_off = ntohs(ip->ip_off);
 552                                 ip->ip_off |= IP_DF;
 553                                 ip->ip_off = htons(ip->ip_off);
 554                         }
 555                 }
 556         }
 557
 558 #ifdef DEV_ENC
 559         /* pass the mbuf to enc0 for bpf processing */
 560         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
 561         /* pass the mbuf to enc0 for packet filtering */
 562         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 563                 goto bad;
 564 #endif
 565
 566         /*
 567          * Dispatch to the appropriate IPsec transform logic.  The
 568          * packet will be returned for transmission after crypto
 569          * processing, etc. are completed.  For encapsulation we
 570          * bypass this call because of the explicit call done above
 571          * (necessary to deal with IP_DF handling for IPv4).
 572          *
 573          * NB: m & sav are ``passed to caller'' who's reponsible for
 574          *     for reclaiming their resources.
 575          */
 576         if (sav->tdb_xform->xf_type != XF_IP4) {
 577                 ip = mtod(m, struct ip *);
 578                 i = ip->ip_hl << 2;
 579                 off = offsetof(struct ip, ip_p);
 580                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 581         } else {
 582                 error = ipsec_process_done(m, isr);
 583         }
 584         IPSECREQUEST_UNLOCK(isr);
 585         return error;
 586 bad:
 587         if (isr)
 588                 IPSECREQUEST_UNLOCK(isr);
 589         if (m)
 590                 m_freem(m);
 591         return error;
 592 }
 593 #endif
 594
 595 #ifdef INET6
 596 /*
 597  * Chop IP6 header from the payload.
 598  */
 599 static struct mbuf *
 600 ipsec6_splithdr(struct mbuf *m)
 601 {
 602         struct mbuf *mh;
 603         struct ip6_hdr *ip6;
 604         int hlen;
 605
 606         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
 607                 ("first mbuf too short, len %u", m->m_len));
 608         ip6 = mtod(m, struct ip6_hdr *);
 609         hlen = sizeof(struct ip6_hdr);
 610         if (m->m_len > hlen) {
 611                 MGETHDR(mh, M_DONTWAIT, MT_DATA);
 612                 if (!mh) {
 613                         m_freem(m);
 614                         return NULL;
 615                 }
 616                 M_MOVE_PKTHDR(mh, m);
 617                 MH_ALIGN(mh, hlen);
 618                 m->m_len -= hlen;
 619                 m->m_data += hlen;
 620                 mh->m_next = m;
 621                 m = mh;
 622                 m->m_len = hlen;
 623                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 624         } else if (m->m_len < hlen) {
 625                 m = m_pullup(m, hlen);
 626                 if (!m)
 627                         return NULL;
 628         }
 629         return m;
 630 }
 631
 632 /*
 633  * IPsec output logic for IPv6, transport mode.
 634  */
 635 int
 636 ipsec6_output_trans(
 637         struct ipsec_output_state *state,
 638         u_char *nexthdrp,
 639         struct mbuf *mprev,
 640         struct secpolicy *sp,
 641         int flags,
 642         int *tun)
 643 {
 644         struct ipsecrequest *isr;
 645         struct secasindex saidx;
 646         int error = 0;
 647         struct mbuf *m;
 648
 649         IPSEC_ASSERT(state != NULL, ("null state"));
 650         IPSEC_ASSERT(state->m != NULL, ("null m"));
 651         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
 652         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
 653         IPSEC_ASSERT(sp != NULL, ("null sp"));
 654         IPSEC_ASSERT(tun != NULL, ("null tun"));
 655
 656         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 657                 printf("%s: applied SP\n", __func__);
 658                 kdebug_secpolicy(sp));
 659
 660         isr = sp->req;
 661         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 662                 /* the rest will be handled by ipsec6_output_tunnel() */
 663                 *tun = 1;               /* need tunnel-mode processing */
 664                 return 0;
 665         }
 666
 667         *tun = 0;
 668         m = state->m;
 669
 670         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 671         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 672         if (isr == NULL) {
 673                 if (error != 0) {
 674 #ifdef notdef
 675                         /* XXX should notification be done for all errors ? */
 676                         /*
 677                          * Notify the fact that the packet is discarded
 678                          * to ourselves. I believe this is better than
 679                          * just silently discarding. (jinmei@kame.net)
 680                          * XXX: should we restrict the error to TCP packets?
 681                          * XXX: should we directly notify sockets via
 682                          *      pfctlinputs?
 683                          */
 684                         icmp6_error(m, ICMP6_DST_UNREACH,
 685                                     ICMP6_DST_UNREACH_ADMIN, 0);
 686                         m = NULL;       /* NB: icmp6_error frees mbuf */
 687 #endif
 688                         goto bad;
 689                 }
 690                 return EJUSTRETURN;
 691         }
 692
 693         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 694                                                   sizeof (struct ip6_hdr),
 695                                                   offsetof(struct ip6_hdr,
 696                                                            ip6_nxt));
 697         IPSECREQUEST_UNLOCK(isr);
 698         return error;
 699 bad:
 700         if (isr)
 701                 IPSECREQUEST_UNLOCK(isr);
 702         if (m)
 703                 m_freem(m);
 704         state->m = NULL;
 705         return error;
 706 }
 707
 708 static int
 709 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 710 {
 711         struct ip6_hdr *oip6;
 712         struct ip6_hdr *ip6;
 713         size_t plen;
 714
 715         /* can't tunnel between different AFs */
 716         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 717             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 718                 m_freem(m);
 719                 return EINVAL;
 720         }
 721         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
 722                 ("mbuf wrong size; len %u", m->m_len));
 723
 724
 725         /*
 726          * grow the mbuf to accomodate the new IPv6 header.
 727          */
 728         plen = m->m_pkthdr.len;
 729         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 730                 struct mbuf *n;
 731                 MGET(n, M_DONTWAIT, MT_DATA);
 732                 if (!n) {
 733                         m_freem(m);
 734                         return ENOBUFS;
 735                 }
 736                 n->m_len = sizeof(struct ip6_hdr);
 737                 n->m_next = m->m_next;
 738                 m->m_next = n;
 739                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 740                 oip6 = mtod(n, struct ip6_hdr *);
 741         } else {
 742                 m->m_next->m_len += sizeof(struct ip6_hdr);
 743                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 744                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 745                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 746         }
 747         ip6 = mtod(m, struct ip6_hdr *);
 748         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 749
 750         /* Fake link-local scope-class addresses */
 751         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 752                 oip6->ip6_src.s6_addr16[1] = 0;
 753         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 754                 oip6->ip6_dst.s6_addr16[1] = 0;
 755
 756         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 757         /* ECN consideration. */
 758         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 759         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 760                 ip6->ip6_plen = htons(plen);
 761         else {
 762                 /* ip6->ip6_plen will be updated in ip6_output() */
 763         }
 764         ip6->ip6_nxt = IPPROTO_IPV6;
 765         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
 766         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
 767         ip6->ip6_hlim = IPV6_DEFHLIM;
 768
 769         /* XXX Should ip6_src be updated later ? */
 770
 771         return 0;
 772 }
 773
 774 /*
 775  * IPsec output logic for IPv6, tunnel mode.
 776  */
 777 int
 778 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 779 {
 780         struct ip6_hdr *ip6;
 781         struct ipsecrequest *isr;
 782         struct secasindex saidx;
 783         int error;
 784         struct sockaddr_in6 *dst6;
 785         struct mbuf *m;
 786
 787         IPSEC_ASSERT(state != NULL, ("null state"));
 788         IPSEC_ASSERT(state->m != NULL, ("null m"));
 789         IPSEC_ASSERT(sp != NULL, ("null sp"));
 790
 791         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 792                 printf("%s: applied SP\n", __func__);
 793                 kdebug_secpolicy(sp));
 794
 795         m = state->m;
 796         /*
 797          * transport mode ipsec (before the 1st tunnel mode) is already
 798          * processed by ipsec6_output_trans().
 799          */
 800         for (isr = sp->req; isr; isr = isr->next) {
 801                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 802                         break;
 803         }
 804
 805         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 806         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 807         if (isr == NULL) {
 808                 if (error != 0)
 809                         goto bad;
 810                 return EJUSTRETURN;
 811         }
 812
 813 #ifdef DEV_ENC
 814         encif->if_opackets++;
 815         encif->if_obytes += m->m_pkthdr.len;
 816
 817         /* pass the mbuf to enc0 for bpf processing */
 818         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
 819         /* pass the mbuf to enc0 for packet filtering */
 820         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 821                 goto bad;
 822 #endif
 823
 824         /*
 825          * There may be the case that SA status will be changed when
 826          * we are refering to one. So calling splsoftnet().
 827          */
 828         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 829                 /*
 830                  * build IPsec tunnel.
 831                  */
 832                 /* XXX should be processed with other familiy */
 833                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 834                         ipseclog((LOG_ERR, "%s: family mismatched between "
 835                             "inner and outer, spi=%u\n", __func__,
 836                             ntohl(isr->sav->spi)));
 837                         V_ipsec6stat.ips_out_inval++;
 838                         error = EAFNOSUPPORT;
 839                         goto bad;
 840                 }
 841
 842                 m = ipsec6_splithdr(m);
 843                 if (!m) {
 844                         V_ipsec6stat.ips_out_nomem++;
 845                         error = ENOMEM;
 846                         goto bad;
 847                 }
 848                 error = ipsec6_encapsulate(m, isr->sav);
 849                 if (error) {
 850                         m = NULL;
 851                         goto bad;
 852                 }
 853                 ip6 = mtod(m, struct ip6_hdr *);
 854
 855                 state->ro =
 856                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
 857                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 858                 dst6 = (struct sockaddr_in6 *)state->dst;
 859                 if (state->ro->ro_rt
 860                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 861                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 862                         RTFREE(state->ro->ro_rt);
 863                         state->ro->ro_rt = NULL;
 864                 }
 865                 if (state->ro->ro_rt == NULL) {
 866                         bzero(dst6, sizeof(*dst6));
 867                         dst6->sin6_family = AF_INET6;
 868                         dst6->sin6_len = sizeof(*dst6);
 869                         dst6->sin6_addr = ip6->ip6_dst;
 870                         rtalloc(state->ro);
 871                 }
 872                 if (state->ro->ro_rt == NULL) {
 873                         V_ip6stat.ip6s_noroute++;
 874                         V_ipsec6stat.ips_out_noroute++;
 875                         error = EHOSTUNREACH;
 876                         goto bad;
 877                 }
 878
 879                 /* adjust state->dst if tunnel endpoint is offlink */
 880                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
 881                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 882         }
 883
 884         m = ipsec6_splithdr(m);
 885         if (!m) {
 886                 V_ipsec6stat.ips_out_nomem++;
 887                 error = ENOMEM;
 888                 goto bad;
 889         }
 890         ip6 = mtod(m, struct ip6_hdr *);
 891
 892 #ifdef DEV_ENC
 893         /* pass the mbuf to enc0 for bpf processing */
 894         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
 895         /* pass the mbuf to enc0 for packet filtering */
 896         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 897                 goto bad;
 898 #endif
 899
 900         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 901                 sizeof (struct ip6_hdr),
 902                 offsetof(struct ip6_hdr, ip6_nxt));
 903         IPSECREQUEST_UNLOCK(isr);
 904         return error;
 905 bad:
 906         if (isr)
 907                 IPSECREQUEST_UNLOCK(isr);
 908         if (m)
 909                 m_freem(m);
 910         state->m = NULL;
 911         return error;
 912 }
 913 #endif /*INET6*/