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                 IPSECSTAT_INC(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         m_addr_changed(m);
 194
 195         /*
 196          * We're done with IPsec processing, transmit the packet using the
 197          * appropriate network protocol (IP or IPv6). SPD lookup will be
 198          * performed again there.
 199          */
 200         switch (saidx->dst.sa.sa_family) {
 201 #ifdef INET
 202         struct ip *ip;
 203         case AF_INET:
 204                 ip = mtod(m, struct ip *);
 205                 ip->ip_len = ntohs(ip->ip_len);
 206                 ip->ip_off = ntohs(ip->ip_off);
 207
 208 #ifdef IPSEC_NAT_T
 209                 /*
 210                  * If NAT-T is enabled, now that all IPsec processing is done
 211                  * insert UDP encapsulation header after IP header.
 212                  */
 213                 if (sav->natt_type) {
 214                         const int hlen = (ip->ip_hl << 2);
 215                         int size, off;
 216                         struct mbuf *mi;
 217                         struct udphdr *udp;
 218
 219                         size = sizeof(struct udphdr);
 220                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
 221                                 /*
 222                                  * draft-ietf-ipsec-nat-t-ike-0[01].txt and
 223                                  * draft-ietf-ipsec-udp-encaps-(00/)01.txt,
 224                                  * ignoring possible AH mode
 225                                  * non-IKE marker + non-ESP marker
 226                                  * from draft-ietf-ipsec-udp-encaps-00.txt.
 227                                  */
 228                                 size += sizeof(u_int64_t);
 229                         }
 230                         mi = m_makespace(m, hlen, size, &off);
 231                         if (mi == NULL) {
 232                                 DPRINTF(("%s: m_makespace for udphdr failed\n",
 233                                     __func__));
 234                                 error = ENOBUFS;
 235                                 goto bad;
 236                         }
 237
 238                         udp = (struct udphdr *)(mtod(mi, caddr_t) + off);
 239                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 240                                 udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
 241                         else
 242                                 udp->uh_sport =
 243                                         KEY_PORTFROMSADDR(&sav->sah->saidx.src);
 244                         udp->uh_dport = KEY_PORTFROMSADDR(&sav->sah->saidx.dst);
 245                         udp->uh_sum = 0;
 246                         udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
 247                         ip->ip_len = m->m_pkthdr.len;
 248                         ip->ip_p = IPPROTO_UDP;
 249
 250                         if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
 251                                 *(u_int64_t *)(udp + 1) = 0;
 252                 }
 253 #endif /* IPSEC_NAT_T */
 254
 255                 return ip_output(m, NULL, NULL, IP_RAWOUTPUT, NULL, NULL);
 256 #endif /* INET */
 257 #ifdef INET6
 258         case AF_INET6:
 259                 /*
 260                  * We don't need massage, IPv6 header fields are always in
 261                  * net endian.
 262                  */
 263                 return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
 264 #endif /* INET6 */
 265         }
 266         panic("ipsec_process_done");
 267 bad:
 268         m_freem(m);
 269         return (error);
 270 }
 271
 272 static struct ipsecrequest *
 273 ipsec_nextisr(
 274         struct mbuf *m,
 275         struct ipsecrequest *isr,
 276         int af,
 277         struct secasindex *saidx,
 278         int *error
 279 )
 280 {
 281 #define IPSEC_OSTAT(name)       do {            \
 282         if (isr->saidx.proto == IPPROTO_ESP)    \
 283                 ESPSTAT_INC(esps_##name);       \
 284         else if (isr->saidx.proto == IPPROTO_AH)\
 285                 AHSTAT_INC(ahs_##name);         \
 286         else                                    \
 287                 IPCOMPSTAT_INC(ipcomps_##name); \
 288 } while (0)
 289         struct secasvar *sav;
 290
 291         IPSECREQUEST_LOCK_ASSERT(isr);
 292
 293         IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
 294                 ("invalid address family %u", af));
 295 again:
 296         /*
 297          * Craft SA index to search for proper SA.  Note that
 298          * we only fillin unspecified SA peers for transport
 299          * mode; for tunnel mode they must already be filled in.
 300          */
 301         *saidx = isr->saidx;
 302         if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
 303                 /* Fillin unspecified SA peers only for transport mode */
 304                 if (af == AF_INET) {
 305                         struct sockaddr_in *sin;
 306                         struct ip *ip = mtod(m, struct ip *);
 307
 308                         if (saidx->src.sa.sa_len == 0) {
 309                                 sin = &saidx->src.sin;
 310                                 sin->sin_len = sizeof(*sin);
 311                                 sin->sin_family = AF_INET;
 312                                 sin->sin_port = IPSEC_PORT_ANY;
 313                                 sin->sin_addr = ip->ip_src;
 314                         }
 315                         if (saidx->dst.sa.sa_len == 0) {
 316                                 sin = &saidx->dst.sin;
 317                                 sin->sin_len = sizeof(*sin);
 318                                 sin->sin_family = AF_INET;
 319                                 sin->sin_port = IPSEC_PORT_ANY;
 320                                 sin->sin_addr = ip->ip_dst;
 321                         }
 322                 } else {
 323                         struct sockaddr_in6 *sin6;
 324                         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 325
 326                         if (saidx->src.sin6.sin6_len == 0) {
 327                                 sin6 = (struct sockaddr_in6 *)&saidx->src;
 328                                 sin6->sin6_len = sizeof(*sin6);
 329                                 sin6->sin6_family = AF_INET6;
 330                                 sin6->sin6_port = IPSEC_PORT_ANY;
 331                                 sin6->sin6_addr = ip6->ip6_src;
 332                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
 333                                         /* fix scope id for comparing SPD */
 334                                         sin6->sin6_addr.s6_addr16[1] = 0;
 335                                         sin6->sin6_scope_id =
 336                                             ntohs(ip6->ip6_src.s6_addr16[1]);
 337                                 }
 338                         }
 339                         if (saidx->dst.sin6.sin6_len == 0) {
 340                                 sin6 = (struct sockaddr_in6 *)&saidx->dst;
 341                                 sin6->sin6_len = sizeof(*sin6);
 342                                 sin6->sin6_family = AF_INET6;
 343                                 sin6->sin6_port = IPSEC_PORT_ANY;
 344                                 sin6->sin6_addr = ip6->ip6_dst;
 345                                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
 346                                         /* fix scope id for comparing SPD */
 347                                         sin6->sin6_addr.s6_addr16[1] = 0;
 348                                         sin6->sin6_scope_id =
 349                                             ntohs(ip6->ip6_dst.s6_addr16[1]);
 350                                 }
 351                         }
 352                 }
 353         }
 354
 355         /*
 356          * Lookup SA and validate it.
 357          */
 358         *error = key_checkrequest(isr, saidx);
 359         if (*error != 0) {
 360                 /*
 361                  * IPsec processing is required, but no SA found.
 362                  * I assume that key_acquire() had been called
 363                  * to get/establish the SA. Here I discard
 364                  * this packet because it is responsibility for
 365                  * upper layer to retransmit the packet.
 366                  */
 367                 IPSECSTAT_INC(ips_out_nosa);
 368                 goto bad;
 369         }
 370         sav = isr->sav;
 371         if (sav == NULL) {
 372                 IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
 373                         ("no SA found, but required; level %u",
 374                         ipsec_get_reqlevel(isr)));
 375                 IPSECREQUEST_UNLOCK(isr);
 376                 isr = isr->next;
 377                 /*
 378                  * If isr is NULL, we found a 'use' policy w/o SA.
 379                  * Return w/o error and w/o isr so we can drop out
 380                  * and continue w/o IPsec processing.
 381                  */
 382                 if (isr == NULL)
 383                         return isr;
 384                 IPSECREQUEST_LOCK(isr);
 385                 goto again;
 386         }
 387
 388         /*
 389          * Check system global policy controls.
 390          */
 391         if ((isr->saidx.proto == IPPROTO_ESP && !V_esp_enable) ||
 392             (isr->saidx.proto == IPPROTO_AH && !V_ah_enable) ||
 393             (isr->saidx.proto == IPPROTO_IPCOMP && !V_ipcomp_enable)) {
 394                 DPRINTF(("%s: IPsec outbound packet dropped due"
 395                         " to policy (check your sysctls)\n", __func__));
 396                 IPSEC_OSTAT(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(noxform);
 408                 *error = EHOSTUNREACH;
 409                 goto bad;
 410         }
 411         return isr;
 412 bad:
 413         IPSEC_ASSERT(*error != 0, ("error return w/ no error code"));
 414         IPSECREQUEST_UNLOCK(isr);
 415         return NULL;
 416 #undef IPSEC_OSTAT
 417 }
 418
 419 #ifdef INET
 420 /*
 421  * IPsec output logic for IPv4.
 422  */
 423 int
 424 ipsec4_process_packet(
 425         struct mbuf *m,
 426         struct ipsecrequest *isr,
 427         int flags,
 428         int tunalready)
 429 {
 430         struct secasindex saidx;
 431         struct secasvar *sav;
 432         struct ip *ip;
 433         int error, i, off;
 434
 435         IPSEC_ASSERT(m != NULL, ("null mbuf"));
 436         IPSEC_ASSERT(isr != NULL, ("null isr"));
 437
 438         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 439
 440         isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
 441         if (isr == NULL) {
 442                 if (error != 0)
 443                         goto bad;
 444                 return EJUSTRETURN;
 445         }
 446
 447         sav = isr->sav;
 448
 449 #ifdef DEV_ENC
 450         encif->if_opackets++;
 451         encif->if_obytes += m->m_pkthdr.len;
 452
 453         /* pass the mbuf to enc0 for bpf processing */
 454         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_BEFORE);
 455         /* pass the mbuf to enc0 for packet filtering */
 456         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 457                 goto bad;
 458 #endif
 459
 460         if (!tunalready) {
 461                 union sockaddr_union *dst = &sav->sah->saidx.dst;
 462                 int setdf;
 463
 464                 /*
 465                  * Collect IP_DF state from the outer header.
 466                  */
 467                 if (dst->sa.sa_family == AF_INET) {
 468                         if (m->m_len < sizeof (struct ip) &&
 469                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 470                                 error = ENOBUFS;
 471                                 goto bad;
 472                         }
 473                         ip = mtod(m, struct ip *);
 474                         /* Honor system-wide control of how to handle IP_DF */
 475                         switch (V_ip4_ipsec_dfbit) {
 476                         case 0:                 /* clear in outer header */
 477                         case 1:                 /* set in outer header */
 478                                 setdf = V_ip4_ipsec_dfbit;
 479                                 break;
 480                         default:                /* propagate to outer header */
 481                                 setdf = ntohs(ip->ip_off & IP_DF);
 482                                 break;
 483                         }
 484                 } else {
 485                         ip = NULL;              /* keep compiler happy */
 486                         setdf = 0;
 487                 }
 488                 /* Do the appropriate encapsulation, if necessary */
 489                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
 490                     dst->sa.sa_family != AF_INET ||         /* PF mismatch */
 491 #if 0
 492                     (sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
 493                     sav->tdb_xform->xf_type == XF_IP4 ||    /* ditto */
 494 #endif
 495                     (dst->sa.sa_family == AF_INET &&        /* Proxy */
 496                      dst->sin.sin_addr.s_addr != INADDR_ANY &&
 497                      dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
 498                         struct mbuf *mp;
 499
 500                         /* Fix IPv4 header checksum and length */
 501                         if (m->m_len < sizeof (struct ip) &&
 502                             (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 503                                 error = ENOBUFS;
 504                                 goto bad;
 505                         }
 506                         ip = mtod(m, struct ip *);
 507                         ip->ip_len = htons(m->m_pkthdr.len);
 508                         ip->ip_sum = 0;
 509                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 510
 511                         /* Encapsulate the packet */
 512                         error = ipip_output(m, isr, &mp, 0, 0);
 513                         if (mp == NULL && !error) {
 514                                 /* Should never happen. */
 515                                 DPRINTF(("%s: ipip_output returns no mbuf and "
 516                                         "no error!", __func__));
 517                                 error = EFAULT;
 518                         }
 519                         if (error) {
 520                                 if (mp) {
 521                                         /* XXX: Should never happen! */
 522                                         m_freem(mp);
 523                                 }
 524                                 m = NULL; /* ipip_output() already freed it */
 525                                 goto bad;
 526                         }
 527                         m = mp, mp = NULL;
 528                         /*
 529                          * ipip_output clears IP_DF in the new header.  If
 530                          * we need to propagate IP_DF from the outer header,
 531                          * then we have to do it here.
 532                          *
 533                          * XXX shouldn't assume what ipip_output does.
 534                          */
 535                         if (dst->sa.sa_family == AF_INET && setdf) {
 536                                 if (m->m_len < sizeof (struct ip) &&
 537                                     (m = m_pullup(m, sizeof (struct ip))) == NULL) {
 538                                         error = ENOBUFS;
 539                                         goto bad;
 540                                 }
 541                                 ip = mtod(m, struct ip *);
 542                                 ip->ip_off = ntohs(ip->ip_off);
 543                                 ip->ip_off |= IP_DF;
 544                                 ip->ip_off = htons(ip->ip_off);
 545                         }
 546                 }
 547         }
 548
 549 #ifdef DEV_ENC
 550         /* pass the mbuf to enc0 for bpf processing */
 551         ipsec_bpf(m, sav, AF_INET, ENC_OUT|ENC_AFTER);
 552         /* pass the mbuf to enc0 for packet filtering */
 553         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 554                 goto bad;
 555 #endif
 556
 557         /*
 558          * Dispatch to the appropriate IPsec transform logic.  The
 559          * packet will be returned for transmission after crypto
 560          * processing, etc. are completed.  For encapsulation we
 561          * bypass this call because of the explicit call done above
 562          * (necessary to deal with IP_DF handling for IPv4).
 563          *
 564          * NB: m & sav are ``passed to caller'' who's reponsible for
 565          *     for reclaiming their resources.
 566          */
 567         if (sav->tdb_xform->xf_type != XF_IP4) {
 568                 ip = mtod(m, struct ip *);
 569                 i = ip->ip_hl << 2;
 570                 off = offsetof(struct ip, ip_p);
 571                 error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
 572         } else {
 573                 error = ipsec_process_done(m, isr);
 574         }
 575         IPSECREQUEST_UNLOCK(isr);
 576         return error;
 577 bad:
 578         if (isr)
 579                 IPSECREQUEST_UNLOCK(isr);
 580         if (m)
 581                 m_freem(m);
 582         return error;
 583 }
 584 #endif
 585
 586 #ifdef INET6
 587 /*
 588  * Chop IP6 header from the payload.
 589  */
 590 static struct mbuf *
 591 ipsec6_splithdr(struct mbuf *m)
 592 {
 593         struct mbuf *mh;
 594         struct ip6_hdr *ip6;
 595         int hlen;
 596
 597         IPSEC_ASSERT(m->m_len >= sizeof (struct ip6_hdr),
 598                 ("first mbuf too short, len %u", m->m_len));
 599         ip6 = mtod(m, struct ip6_hdr *);
 600         hlen = sizeof(struct ip6_hdr);
 601         if (m->m_len > hlen) {
 602                 MGETHDR(mh, M_DONTWAIT, MT_DATA);
 603                 if (!mh) {
 604                         m_freem(m);
 605                         return NULL;
 606                 }
 607                 M_MOVE_PKTHDR(mh, m);
 608                 MH_ALIGN(mh, hlen);
 609                 m->m_len -= hlen;
 610                 m->m_data += hlen;
 611                 mh->m_next = m;
 612                 m = mh;
 613                 m->m_len = hlen;
 614                 bcopy((caddr_t)ip6, mtod(m, caddr_t), hlen);
 615         } else if (m->m_len < hlen) {
 616                 m = m_pullup(m, hlen);
 617                 if (!m)
 618                         return NULL;
 619         }
 620         return m;
 621 }
 622
 623 /*
 624  * IPsec output logic for IPv6, transport mode.
 625  */
 626 int
 627 ipsec6_output_trans(
 628         struct ipsec_output_state *state,
 629         u_char *nexthdrp,
 630         struct mbuf *mprev,
 631         struct secpolicy *sp,
 632         int flags,
 633         int *tun)
 634 {
 635         struct ipsecrequest *isr;
 636         struct secasindex saidx;
 637         int error = 0;
 638         struct mbuf *m;
 639
 640         IPSEC_ASSERT(state != NULL, ("null state"));
 641         IPSEC_ASSERT(state->m != NULL, ("null m"));
 642         IPSEC_ASSERT(nexthdrp != NULL, ("null nexthdrp"));
 643         IPSEC_ASSERT(mprev != NULL, ("null mprev"));
 644         IPSEC_ASSERT(sp != NULL, ("null sp"));
 645         IPSEC_ASSERT(tun != NULL, ("null tun"));
 646
 647         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 648                 printf("%s: applied SP\n", __func__);
 649                 kdebug_secpolicy(sp));
 650
 651         isr = sp->req;
 652         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 653                 /* the rest will be handled by ipsec6_output_tunnel() */
 654                 *tun = 1;               /* need tunnel-mode processing */
 655                 return 0;
 656         }
 657
 658         *tun = 0;
 659         m = state->m;
 660
 661         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 662         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 663         if (isr == NULL) {
 664                 if (error != 0) {
 665 #ifdef notdef
 666                         /* XXX should notification be done for all errors ? */
 667                         /*
 668                          * Notify the fact that the packet is discarded
 669                          * to ourselves. I believe this is better than
 670                          * just silently discarding. (jinmei@kame.net)
 671                          * XXX: should we restrict the error to TCP packets?
 672                          * XXX: should we directly notify sockets via
 673                          *      pfctlinputs?
 674                          */
 675                         icmp6_error(m, ICMP6_DST_UNREACH,
 676                                     ICMP6_DST_UNREACH_ADMIN, 0);
 677                         m = NULL;       /* NB: icmp6_error frees mbuf */
 678 #endif
 679                         goto bad;
 680                 }
 681                 return EJUSTRETURN;
 682         }
 683
 684         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 685                                                   sizeof (struct ip6_hdr),
 686                                                   offsetof(struct ip6_hdr,
 687                                                            ip6_nxt));
 688         IPSECREQUEST_UNLOCK(isr);
 689         return error;
 690 bad:
 691         if (isr)
 692                 IPSECREQUEST_UNLOCK(isr);
 693         if (m)
 694                 m_freem(m);
 695         state->m = NULL;
 696         return error;
 697 }
 698
 699 static int
 700 ipsec6_encapsulate(struct mbuf *m, struct secasvar *sav)
 701 {
 702         struct ip6_hdr *oip6;
 703         struct ip6_hdr *ip6;
 704         size_t plen;
 705
 706         /* can't tunnel between different AFs */
 707         if (sav->sah->saidx.src.sa.sa_family != AF_INET6 ||
 708             sav->sah->saidx.dst.sa.sa_family != AF_INET6) {
 709                 m_freem(m);
 710                 return EINVAL;
 711         }
 712         IPSEC_ASSERT(m->m_len == sizeof (struct ip6_hdr),
 713                 ("mbuf wrong size; len %u", m->m_len));
 714
 715
 716         /*
 717          * grow the mbuf to accomodate the new IPv6 header.
 718          */
 719         plen = m->m_pkthdr.len;
 720         if (M_LEADINGSPACE(m->m_next) < sizeof(struct ip6_hdr)) {
 721                 struct mbuf *n;
 722                 MGET(n, M_DONTWAIT, MT_DATA);
 723                 if (!n) {
 724                         m_freem(m);
 725                         return ENOBUFS;
 726                 }
 727                 n->m_len = sizeof(struct ip6_hdr);
 728                 n->m_next = m->m_next;
 729                 m->m_next = n;
 730                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 731                 oip6 = mtod(n, struct ip6_hdr *);
 732         } else {
 733                 m->m_next->m_len += sizeof(struct ip6_hdr);
 734                 m->m_next->m_data -= sizeof(struct ip6_hdr);
 735                 m->m_pkthdr.len += sizeof(struct ip6_hdr);
 736                 oip6 = mtod(m->m_next, struct ip6_hdr *);
 737         }
 738         ip6 = mtod(m, struct ip6_hdr *);
 739         bcopy((caddr_t)ip6, (caddr_t)oip6, sizeof(struct ip6_hdr));
 740
 741         /* Fake link-local scope-class addresses */
 742         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 743                 oip6->ip6_src.s6_addr16[1] = 0;
 744         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 745                 oip6->ip6_dst.s6_addr16[1] = 0;
 746
 747         /* construct new IPv6 header. see RFC 2401 5.1.2.2 */
 748         /* ECN consideration. */
 749         ip6_ecn_ingress(V_ip6_ipsec_ecn, &ip6->ip6_flow, &oip6->ip6_flow);
 750         if (plen < IPV6_MAXPACKET - sizeof(struct ip6_hdr))
 751                 ip6->ip6_plen = htons(plen);
 752         else {
 753                 /* ip6->ip6_plen will be updated in ip6_output() */
 754         }
 755         ip6->ip6_nxt = IPPROTO_IPV6;
 756         ip6->ip6_src = sav->sah->saidx.src.sin6.sin6_addr;
 757         ip6->ip6_dst = sav->sah->saidx.dst.sin6.sin6_addr;
 758         ip6->ip6_hlim = IPV6_DEFHLIM;
 759
 760         /* XXX Should ip6_src be updated later ? */
 761
 762         return 0;
 763 }
 764
 765 /*
 766  * IPsec output logic for IPv6, tunnel mode.
 767  */
 768 int
 769 ipsec6_output_tunnel(struct ipsec_output_state *state, struct secpolicy *sp, int flags)
 770 {
 771         struct ip6_hdr *ip6;
 772         struct ipsecrequest *isr;
 773         struct secasindex saidx;
 774         int error;
 775         struct sockaddr_in6 *dst6;
 776         struct mbuf *m;
 777
 778         IPSEC_ASSERT(state != NULL, ("null state"));
 779         IPSEC_ASSERT(state->m != NULL, ("null m"));
 780         IPSEC_ASSERT(sp != NULL, ("null sp"));
 781
 782         KEYDEBUG(KEYDEBUG_IPSEC_DATA,
 783                 printf("%s: applied SP\n", __func__);
 784                 kdebug_secpolicy(sp));
 785
 786         m = state->m;
 787         /*
 788          * transport mode ipsec (before the 1st tunnel mode) is already
 789          * processed by ipsec6_output_trans().
 790          */
 791         for (isr = sp->req; isr; isr = isr->next) {
 792                 if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
 793                         break;
 794         }
 795
 796         IPSECREQUEST_LOCK(isr);         /* insure SA contents don't change */
 797         isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
 798         if (isr == NULL) {
 799                 if (error != 0)
 800                         goto bad;
 801                 return EJUSTRETURN;
 802         }
 803
 804 #ifdef DEV_ENC
 805         encif->if_opackets++;
 806         encif->if_obytes += m->m_pkthdr.len;
 807
 808         /* pass the mbuf to enc0 for bpf processing */
 809         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_BEFORE);
 810         /* pass the mbuf to enc0 for packet filtering */
 811         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_BEFORE)) != 0)
 812                 goto bad;
 813 #endif
 814
 815         /*
 816          * There may be the case that SA status will be changed when
 817          * we are refering to one. So calling splsoftnet().
 818          */
 819         if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
 820                 /*
 821                  * build IPsec tunnel.
 822                  */
 823                 /* XXX should be processed with other familiy */
 824                 if (isr->sav->sah->saidx.src.sa.sa_family != AF_INET6) {
 825                         ipseclog((LOG_ERR, "%s: family mismatched between "
 826                             "inner and outer, spi=%u\n", __func__,
 827                             ntohl(isr->sav->spi)));
 828                         IPSEC6STAT_INC(ips_out_inval);
 829                         error = EAFNOSUPPORT;
 830                         goto bad;
 831                 }
 832
 833                 m = ipsec6_splithdr(m);
 834                 if (!m) {
 835                         IPSEC6STAT_INC(ips_out_nomem);
 836                         error = ENOMEM;
 837                         goto bad;
 838                 }
 839                 error = ipsec6_encapsulate(m, isr->sav);
 840                 if (error) {
 841                         m = NULL;
 842                         goto bad;
 843                 }
 844                 ip6 = mtod(m, struct ip6_hdr *);
 845
 846                 state->ro =
 847                     (struct route *)&isr->sav->sah->route_cache.sin6_route;
 848                 state->dst = (struct sockaddr *)&state->ro->ro_dst;
 849                 dst6 = (struct sockaddr_in6 *)state->dst;
 850                 if (state->ro->ro_rt
 851                  && ((state->ro->ro_rt->rt_flags & RTF_UP) == 0
 852                   || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_dst))) {
 853                         RTFREE(state->ro->ro_rt);
 854                         state->ro->ro_rt = NULL;
 855                 }
 856                 if (state->ro->ro_rt == NULL) {
 857                         bzero(dst6, sizeof(*dst6));
 858                         dst6->sin6_family = AF_INET6;
 859                         dst6->sin6_len = sizeof(*dst6);
 860                         dst6->sin6_addr = ip6->ip6_dst;
 861                         rtalloc_ign_fib(state->ro, 0UL, M_GETFIB(m));
 862                 }
 863                 if (state->ro->ro_rt == NULL) {
 864                         IP6STAT_INC(ip6s_noroute);
 865                         IPSEC6STAT_INC(ips_out_noroute);
 866                         error = EHOSTUNREACH;
 867                         goto bad;
 868                 }
 869
 870                 /* adjust state->dst if tunnel endpoint is offlink */
 871                 if (state->ro->ro_rt->rt_flags & RTF_GATEWAY)
 872                         state->dst = (struct sockaddr *)state->ro->ro_rt->rt_gateway;
 873         }
 874
 875         m = ipsec6_splithdr(m);
 876         if (!m) {
 877                 IPSEC6STAT_INC(ips_out_nomem);
 878                 error = ENOMEM;
 879                 goto bad;
 880         }
 881         ip6 = mtod(m, struct ip6_hdr *);
 882
 883 #ifdef DEV_ENC
 884         /* pass the mbuf to enc0 for bpf processing */
 885         ipsec_bpf(m, isr->sav, AF_INET6, ENC_OUT|ENC_AFTER);
 886         /* pass the mbuf to enc0 for packet filtering */
 887         if ((error = ipsec_filter(&m, PFIL_OUT, ENC_OUT|ENC_AFTER)) != 0)
 888                 goto bad;
 889 #endif
 890
 891         error = (*isr->sav->tdb_xform->xf_output)(m, isr, NULL,
 892                 sizeof (struct ip6_hdr),
 893                 offsetof(struct ip6_hdr, ip6_nxt));
 894         IPSECREQUEST_UNLOCK(isr);
 895         return error;
 896 bad:
 897         if (isr)
 898                 IPSECREQUEST_UNLOCK(isr);
 899         if (m)
 900                 m_freem(m);
 901         state->m = NULL;
 902         return error;
 903 }
 904 #endif /*INET6*/