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