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/if_var.h>
  48 #include <net/pfil.h>
  49 #include <net/route.h>
  50 #include <net/vnet.h>
  51
  52 #include <netinet/in.h>
  53 #include <netinet/in_systm.h>
  54 #include <netinet/ip.h>
  55 #include <netinet/ip_var.h>
  56 #include <netinet/in_var.h>
  57 #include <netinet/ip_ecn.h>
  58 #ifdef INET6
  59 #include <netinet6/ip6_ecn.h>
  60 #endif
  61
  62 #include <netinet/ip6.h>
  63 #ifdef INET6
  64 #include <netinet6/ip6_var.h>
  65 #endif
  66 #include <netinet/in_pcb.h>
  67 #ifdef INET6
  68 #include <netinet/icmp6.h>
  69 #endif
  70
  71 #include <netipsec/ipsec.h>
  72 #ifdef INET6
  73 #include <netipsec/ipsec6.h>
  74 #endif
  75 #include <netipsec/ah_var.h>
  76 #include <netipsec/esp_var.h>
  77 #include <netipsec/ipcomp_var.h>
  78
  79 #include <netipsec/xform.h>
  80
  81 #include <netipsec/key.h>
  82 #include <netipsec/keydb.h>
  83 #include <netipsec/key_debug.h>
  84
  85 #include <machine/in_cksum.h>
  86
  87 #ifdef IPSEC_NAT_T
  88 #include <netinet/udp.h>
  89 #endif
  90
  91 #ifdef DEV_ENC
  92 #include <net/if_enc.h>
  93 #endif
  94
  95
  96 int
  97 ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
  98 {
  99         struct tdb_ident *tdbi;
 100         struct m_tag *mtag;
 101         struct secasvar *sav;
 102         struct secasindex *saidx;
 103         int error;
 104
 105         IPSEC_ASSERT(m != NULL, ("null mbuf"));
 106         IPSEC_ASSERT(isr != NULL, ("null ISR"));
 107         sav = isr->sav;
 108         IPSEC_ASSERT(sav != NULL, ("null SA"));
 109         IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
 110
 111         saidx = &sav->sah->saidx;
 112         switch (saidx->dst.sa.sa_family) {
 113 #ifdef INET
 114         case AF_INET:
 115                 /* Fix the header length, for AH processing. */
 116                 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len);
 117                 break;
 118 #endif /* INET */
 119 #ifdef INET6
 120         case AF_INET6:
 121                 /* Fix the header length, for AH processing. */
 122                 if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
 123                         error = ENXIO;
 124                         goto bad;
 125                 }
 126                 if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
 127                         /* No jumbogram support. */
 128                         error = ENXIO;  /*?*/
 129                         goto bad;
 130                 }
 131                 mtod(m, struct ip6_hdr *)->ip6_plen =
 132                         htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 133                 break;
 134 #endif /* INET6 */
 135         default:
 136                 DPRINTF(("%s: unknown protocol family %u\n", __func__,
 137                     saidx->dst.sa.sa_family));
 138                 error = ENXIO;
 139                 goto bad;
 140         }
 141
 142         /*
 143          * Add a record of what we've done or what needs to be done to the
 144          * packet.
 145          */
 146         mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE,
 147                         sizeof(struct tdb_ident), M_NOWAIT);
 148         if (mtag == NULL) {
 149                 DPRINTF(("%s: could not get packet tag\n", __func__));
 150                 error = ENOMEM;
 151                 goto bad;
 152         }
 153
 154         tdbi = (struct tdb_ident *)(mtag + 1);
 155         tdbi->dst = saidx->dst;
 156         tdbi->proto = saidx->proto;
 157         tdbi->spi = sav->spi;
 158         m_tag_prepend(m, mtag);
 159
 160         /*
 161          * If there's another (bundled) SA to apply, do so.
 162          * Note that this puts a burden on the kernel stack size.
 163          * If this is a problem we'll need to introduce a queue
 164          * to set the packet on so we can unwind the stack before
 165          * doing further processing.
 166          */
 167         if (isr->next) {
 168                 IPSECSTAT_INC(ips_out_bundlesa);
 169                 /* XXX-BZ currently only support same AF bundles. */
 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         /*
 195          * We're done with IPsec processing, transmit the packet using the
 196          * appropriate network protocol (IP or IPv6). SPD lookup will be
 197          * performed again there.
 198          */
 199         switch (saidx->dst.sa.sa_family) {
 200 #ifdef INET
 201         case AF_INET:
 202 #ifdef IPSEC_NAT_T
 203                 /*
 204                  * If NAT-T is enabled, now that all IPsec processing is done
 205                  * insert UDP encapsulation header after IP header.
 206                  */
 207                 if (sav->natt_type) {
 208                         struct ip *ip = mtod(m, struct ip *);
 209 #ifdef _IP_VHL
 210                         const int hlen = IP_VHL_HL(ip->ip_vhl);
 211 #else
 212                         const int hlen = (ip->ip_hl << 2);
 213 #endif
 214                         int size, off;
 215                         struct mbuf *mi;
 216                         struct udphdr *udp;
 217
 218                         size = sizeof(struct udphdr);
 219                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
 220                                 /*
 221                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
 222                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
 223                                  * ignoring possible AH mode
 224                                  * non-IKE marker + non-ESP marker
 225                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
 226                                  */
 227                                 size += sizeof(u_int64_t);
 228                         }
 229                         mi = m_makespace(m, hlen, size, &off);
 230                         if (mi == NULL) {
 231                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
 232                                     __func__));
 233                                 error = ENOBUFS;
 234                                 goto bad;
 235                         }
 236
 237                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
 238                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 239                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
 240                         else
 241                                 udp->uh_sport =
 242                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
 243                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
 244                         udp->uh_sum = 0;
 245                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
 246                         ip->ip_len = htons(m->m_pkthdr.len);
 247                         ip->ip_p = IPPROTO_UDP;
 248
 249                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 250                                 *(u_int64_t *)(udp + 1) = 0;
 251                 }
 252 #endif /* IPSEC_NAT_T */
 253
 254                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 255 #endif /* INET */
 256 #ifdef INET6
 257         case AF_INET6:
 258                 /*
 259                  * We don't need massage, IPv6 header fields are always in
 260                  * net endian.
 261                  */
 262                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 263 #endif /* INET6 */
 264         }
 265         panic("ipsec_process_done");
 266 bad:
 267         m_freem(m);
 268         return (error);
 269 }
 270
 271 static struct ipsecrequest *
 272 ipsec_nextisr(
 273         struct mbuf *m,
 274         struct ipsecrequest *isr,
 275         int af,
 276         struct secasindex *saidx,
 277         int *error
 278 )
 279 {
 280 #define IPSEC_OSTAT(name)       do {            \
 281         if (isr->saidx.proto == IPPROTO_ESP)    \
 282                 ESPSTAT_INC(esps_##name);       \
 283         else if (isr->saidx.proto == IPPROTO_AH)\
 284                 AHSTAT_INC(ahs_##name);         \
 285         else                                    \
 286                 IPCOMPSTAT_INC(ipcomps_##name); \
 287 } while (0)
 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                 IPSECSTAT_INC(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(pdrops);
 396                 *error = EHOSTUNREACH;
 397                 goto bad;
 398         }
 399
 400         /*
 401          * Sanity check the SA contents for the caller
 402          * before they invoke the xform output method.
 403          */
 404         if (sav->tdb_xform == NULL) {
 405                 DPRINTF(("%s: no transform for SA\n", __func__));
 406                 IPSEC_OSTAT(noxform);
 407                 *error = EHOSTUNREACH;
 408                 goto bad;
 409         }
 410         return isr;
 411 bad:
 412         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
 413         IPSECREQUEST_UNLOCK(isr);
 414         return NULL;
 415 #undef IPSEC_OSTAT
 416 }
 417
 418 #ifdef INET
 419 /*
 420  * IPsec output logic for IPv4.
 421  */
 422 int
 423 ipsec4_process_packet(
 424         struct mbuf *m,
 425         struct ipsecrequest *isr,
 426         int flags,
 427         int tunalready)
 428 {
 429         struct secasindex saidx;
 430         struct secasvar *sav;
 431         struct ip *ip;
 432         int error, i, off;
 433
 434         IPSEC_ASSERT(m != NULL, ("null mbuf"));
 435         IPSEC_ASSERT(isr != NULL, ("null isr"));
 436
 437         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 438
 439         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 440         if (isr == NULL) {
 441                 if (error != 0)
 442                         goto bad;
 443                 return EJUSTRETURN;
 444         }
 445
 446         sav = isr->sav;
 447
 448 #ifdef DEV_ENC
 449         encif->if_opackets++;
 450         encif->if_obytes += m->m_pkthdr.len;
 451
 452         /* pass the mbuf to enc0 for bpf processing */
 453         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
 454         /* pass the mbuf to enc0 for packet filtering */
 455         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 456                 goto bad;
 457 #endif
 458
 459         if (!tunalready) {
 460                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 461                 int setdf;
 462
 463                 /*
 464                  * Collect IP_DF state from the outer header.
 465                  */
 466                 if (dst->sa.sa_family == AF_INET) {
 467                         if (m->m_len < sizeof (struct ip) &&
 468                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 469                                 error = ENOBUFS;
 470                                 goto bad;
 471                         }
 472                         ip = mtod(m, struct ip *);
 473                         /* Honor system-wide control of how to handle IP_DF */
 474                         switch (V_ip4_ipsec_dfbit) {
 475                         case 0:                 /* clear in outer header */
 476                         case 1:                 /* set in outer header */
 477                                 setdf = V_ip4_ipsec_dfbit;
 478                                 break;
 479                         default:                /* propagate to outer header */
 480                                 setdf = ntohs(ip->ip_off & IP_DF);
 481                                 break;
 482                         }
 483                 } else {
 484                         ip = NULL;              /* keep compiler happy */
 485                         setdf = 0;
 486                 }
 487                 /* Do the appropriate encapsulation, if necessary */
 488                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 489                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 490 #if 0
 491                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 492                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 493 #endif
 494                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 495                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 496                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 497                         struct mbuf *mp;
 498
 499                         /* Fix IPv4 header checksum and length */
 500                         if (m->m_len < sizeof (struct ip) &&
 501                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 502                                 error = ENOBUFS;
 503                                 goto bad;
 504                         }
 505                         ip = mtod(m, struct ip *);
 506                         ip->ip_len = htons(m->m_pkthdr.len);
 507                         ip->ip_sum = 0;
 508 #ifdef _IP_VHL
 509                         if (ip->ip_vhl == IP_VHL_BORING)
 510                                 ip->ip_sum = in_cksum_hdr(ip);
 511                         else
 512                                 ip->ip_sum = in_cksum(m,
 513                                         _IP_VHL_HL(ip->ip_vhl) << 2);
 514 #else
 515                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 516 #endif
 517
 518                         /* Encapsulate the packet */
 519                         error = ipip_output(m, isr, &mp, 0, 0);
 520                         if (mp == NULL && !error) {
 521                                 /* Should never happen. */
 522                                 DPRINTF(("%s: ipip_output returns no mbuf and "
 523                                         "no error!", __func__));
 524                                 error = EFAULT;
 525                         }
 526                         if (error) {
 527                                 if (mp) {
 528                                         /* XXX: Should never happen! */
 529                                         m_freem(mp);
 530                                 }
 531                                 m = NULL; /* ipip_output() already freed it */
 532                                 goto bad;
 533                         }
 534                         m = mp, mp = NULL;
 535                         /*
 536                          * ipip_output clears IP_DF in the new header.  If
 537                          * we need to propagate IP_DF from the outer header,
 538                          * then we have to do it here.
 539                          *
 540                          * XXX shouldn't assume what ipip_output does.
 541                          */
 542                         if (dst->sa.sa_family == AF_INET && setdf) {
 543                                 if (m->m_len < sizeof (struct ip) &&
 544                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 545                                         error = ENOBUFS;
 546                                         goto bad;
 547                                 }
 548                                 ip = mtod(m, struct ip *);
 549                                 ip->ip_off = ntohs(ip->ip_off);
 550                                 ip->ip_off |= IP_DF;
 551                                 ip->ip_off = htons(ip->ip_off);
 552                         }
 553                 }
 554         }
 555
 556 #ifdef DEV_ENC
 557         /* pass the mbuf to enc0 for bpf processing */
 558         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
 559         /* pass the mbuf to enc0 for packet filtering */
 560         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 561                 goto bad;
 562 #endif
 563
 564         /*
 565          * Dispatch to the appropriate IPsec transform logic.  The
 566          * packet will be returned for transmission after crypto
 567          * processing, etc. are completed.  For encapsulation we
 568          * bypass this call because of the explicit call done above
 569          * (necessary to deal with IP_DF handling for IPv4).
 570          *
 571          * NB: m & sav are ``passed to caller'' who's reponsible for
 572          *     for reclaiming their resources.
 573          */
 574         if (sav->tdb_xform->xf_type != XF_IP4) {
 575                 ip = mtod(m, struct ip *);
 576                 i = ip->ip_hl << 2;
 577                 off = offsetof(struct ip, ip_p);
 578                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 579         } else {
 580                 error = ipsec_process_done(m, isr);
 581         }
 582         IPSECREQUEST_UNLOCK(isr);
 583         return error;
 584 bad:
 585         if (isr)
 586                 IPSECREQUEST_UNLOCK(isr);
 587         if (m)
 588                 m_freem(m);
 589         return error;
 590 }
 591 #endif
 592
 593 #ifdef INET6
 594 /*
 595  * Chop IP6 header from the payload.
 596  */
 597 static struct mbuf *
 598 ipsec6_splithdr(struct mbuf *m)
 599 {
 600         struct mbuf *mh;
 601         struct ip6_hdr *ip6;
 602         int hlen;
 603
 604         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
 605                 ("first mbuf too short, len %u", m->m_len));
 606         ip6 = mtod(m, struct ip6_hdr *);
 607         hlen = sizeof(struct ip6_hdr);
 608         if (m->m_len > hlen) {
 609                 MGETHDR(mh, M_NOWAIT, MT_DATA);
 610                 if (!mh) {
 611                         m_freem(m);
 612                         return NULL;
 613                 }
 614                 M_MOVE_PKTHDR(mh, m);
 615                 MH_ALIGN(mh, hlen);
 616                 m->m_len -= hlen;
 617                 m->m_data += hlen;
 618                 mh->m_next = m;
 619                 m = mh;
 620                 m->m_len = hlen;
 621                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 622         } else if (m->m_len < hlen) {
 623                 m = m_pullup(m, hlen);
 624                 if (!m)
 625                         return NULL;
 626         }
 627         return m;
 628 }
 629
 630 /*
 631  * IPsec output logic for IPv6, transport mode.
 632  */
 633 int
 634 ipsec6_output_trans(
 635         struct ipsec_output_state *state,
 636         u_char *nexthdrp,
 637         struct mbuf *mprev,
 638         struct secpolicy *sp,
 639         int flags,
 640         int *tun)
 641 {
 642         struct ipsecrequest *isr;
 643         struct secasindex saidx;
 644         int error = 0;
 645         struct mbuf *m;
 646
 647         IPSEC_ASSERT(state != NULL, ("null state"));
 648         IPSEC_ASSERT(state->m != NULL, ("null m"));
 649         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
 650         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
 651         IPSEC_ASSERT(sp != NULL, ("null sp"));
 652         IPSEC_ASSERT(tun != NULL, ("null tun"));
 653
 654         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 655                 printf("%s: applied SP\n", __func__);
 656                 kdebug_secpolicy(sp));
 657
 658         isr = sp->req;
 659         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 660                 /* the rest will be handled by ipsec6_output_tunnel() */
 661                 *tun = 1;               /* need tunnel-mode processing */
 662                 return 0;
 663         }
 664
 665         *tun = 0;
 666         m = state->m;
 667
 668         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 669         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 670         if (isr == NULL) {
 671                 if (error != 0) {
 672 #ifdef notdef
 673                         /* XXX should notification be done for all errors ? */
 674                         /*
 675                          * Notify the fact that the packet is discarded
 676                          * to ourselves. I believe this is better than
 677                          * just silently discarding. (jinmei@kame.net)
 678                          * XXX: should we restrict the error to TCP packets?
 679                          * XXX: should we directly notify sockets via
 680                          *      pfctlinputs?
 681                          */
 682                         icmp6_error(m, ICMP6_DST_UNREACH,
 683                                     ICMP6_DST_UNREACH_ADMIN, 0);
 684                         m = NULL;       /* NB: icmp6_error frees mbuf */
 685 #endif
 686                         goto bad;
 687                 }
 688                 return EJUSTRETURN;
 689         }
 690
 691         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 692                                                   sizeof (struct ip6_hdr),
 693                                                   offsetof(struct ip6_hdr,
 694                                                            ip6_nxt));
 695         IPSECREQUEST_UNLOCK(isr);
 696         return error;
 697 bad:
 698         if (isr)
 699                 IPSECREQUEST_UNLOCK(isr);
 700         if (m)
 701                 m_freem(m);
 702         state->m = NULL;
 703         return error;
 704 }
 705
 706 static int
 707 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 708 {
 709         struct ip6_hdr *oip6;
 710         struct ip6_hdr *ip6;
 711         size_t plen;
 712
 713         /* can't tunnel between different AFs */
 714         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 715             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 716                 m_freem(m);
 717                 return EINVAL;
 718         }
 719         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
 720                 ("mbuf wrong size; len %u", m->m_len));
 721
 722
 723         /*
 724          * grow the mbuf to accomodate the new IPv6 header.
 725          */
 726         plen = m->m_pkthdr.len;
 727         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 728                 struct mbuf *n;
 729                 MGET(n, M_NOWAIT, MT_DATA);
 730                 if (!n) {
 731                         m_freem(m);
 732                         return ENOBUFS;
 733                 }
 734                 n->m_len = sizeof(struct ip6_hdr);
 735                 n->m_next = m->m_next;
 736                 m->m_next = n;
 737                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 738                 oip6 = mtod(n, struct ip6_hdr *);
 739         } else {
 740                 m->m_next->m_len += sizeof(struct ip6_hdr);
 741                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 742                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 743                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 744         }
 745         ip6 = mtod(m, struct ip6_hdr *);
 746         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 747
 748         /* Fake link-local scope-class addresses */
 749         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 750                 oip6->ip6_src.s6_addr16[1] = 0;
 751         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 752                 oip6->ip6_dst.s6_addr16[1] = 0;
 753
 754         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 755         /* ECN consideration. */
 756         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 757         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 758                 ip6->ip6_plen = htons(plen);
 759         else {
 760                 /* ip6->ip6_plen will be updated in ip6_output() */
 761         }
 762         ip6->ip6_nxt = IPPROTO_IPV6;
 763         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
 764         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
 765         ip6->ip6_hlim = IPV6_DEFHLIM;
 766
 767         /* XXX Should ip6_src be updated later ? */
 768
 769         return 0;
 770 }
 771
 772 /*
 773  * IPsec output logic for IPv6, tunnel mode.
 774  */
 775 int
 776 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 777 {
 778         struct ip6_hdr *ip6;
 779         struct ipsecrequest *isr;
 780         struct secasindex saidx;
 781         int error;
 782         struct sockaddr_in6 *dst6;
 783         struct mbuf *m;
 784
 785         IPSEC_ASSERT(state != NULL, ("null state"));
 786         IPSEC_ASSERT(state->m != NULL, ("null m"));
 787         IPSEC_ASSERT(sp != NULL, ("null sp"));
 788
 789         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 790                 printf("%s: applied SP\n", __func__);
 791                 kdebug_secpolicy(sp));
 792
 793         m = state->m;
 794         /*
 795          * transport mode ipsec (before the 1st tunnel mode) is already
 796          * processed by ipsec6_output_trans().
 797          */
 798         for (isr = sp->req; isr; isr = isr->next) {
 799                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 800                         break;
 801         }
 802
 803         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 804         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 805         if (isr == NULL) {
 806                 if (error != 0)
 807                         goto bad;
 808                 return EJUSTRETURN;
 809         }
 810
 811 #ifdef DEV_ENC
 812         encif->if_opackets++;
 813         encif->if_obytes += m->m_pkthdr.len;
 814
 815         /* pass the mbuf to enc0 for bpf processing */
 816         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
 817         /* pass the mbuf to enc0 for packet filtering */
 818         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 819                 goto bad;
 820 #endif
 821
 822         /*
 823          * There may be the case that SA status will be changed when
 824          * we are refering to one. So calling splsoftnet().
 825          */
 826         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 827                 /*
 828                  * build IPsec tunnel.
 829                  */
 830                 /* XXX should be processed with other familiy */
 831                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 832                         ipseclog((LOG_ERR, "%s: family mismatched between "
 833                             "inner and outer, spi=%u\n", __func__,
 834                             ntohl(isr->sav->spi)));
 835                         IPSEC6STAT_INC(ips_out_inval);
 836                         error = EAFNOSUPPORT;
 837                         goto bad;
 838                 }
 839
 840                 m = ipsec6_splithdr(m);
 841                 if (!m) {
 842                         IPSEC6STAT_INC(ips_out_nomem);
 843                         error = ENOMEM;
 844                         goto bad;
 845                 }
 846                 error = ipsec6_encapsulate(m, isr->sav);
 847                 if (error) {
 848                         m = NULL;
 849                         goto bad;
 850                 }
 851                 ip6 = mtod(m, struct ip6_hdr *);
 852
 853                 state->ro =
 854                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
 855                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 856                 dst6 = (struct sockaddr_in6 *)state->dst;
 857                 if (state->ro->ro_rt
 858                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 859                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 860                         RTFREE(state->ro->ro_rt);
 861                         state->ro->ro_rt = NULL;
 862                 }
 863                 if (state->ro->ro_rt == NULL) {
 864                         bzero(dst6, sizeof(*dst6));
 865                         dst6->sin6_family = AF_INET6;
 866                         dst6->sin6_len = sizeof(*dst6);
 867                         dst6->sin6_addr = ip6->ip6_dst;
 868                         rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
 869                 }
 870                 if (state->ro->ro_rt == NULL) {
 871                         IP6STAT_INC(ip6s_noroute);
 872                         IPSEC6STAT_INC(ips_out_noroute);
 873                         error = EHOSTUNREACH;
 874                         goto bad;
 875                 }
 876
 877                 /* adjust state->dst if tunnel endpoint is offlink */
 878                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
 879                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 880         }
 881
 882         m = ipsec6_splithdr(m);
 883         if (!m) {
 884                 IPSEC6STAT_INC(ips_out_nomem);
 885                 error = ENOMEM;
 886                 goto bad;
 887         }
 888         ip6 = mtod(m, struct ip6_hdr *);
 889
 890 #ifdef DEV_ENC
 891         /* pass the mbuf to enc0 for bpf processing */
 892         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
 893         /* pass the mbuf to enc0 for packet filtering */
 894         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 895                 goto bad;
 896 #endif
 897
 898         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 899                 sizeof (struct ip6_hdr),
 900                 offsetof(struct ip6_hdr, ip6_nxt));
 901         IPSECREQUEST_UNLOCK(isr);
 902         return error;
 903 bad:
 904         if (isr)
 905                 IPSECREQUEST_UNLOCK(isr);
 906         if (m)
 907                 m_freem(m);
 908         state->m = NULL;
 909         return error;
 910 }
 911 #endif /*INET6*/