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