sys/netproto/ipsec/xform_ipip.c

   1 /*      $FreeBSD: src/sys/netipsec/xform_ipip.c,v 1.3.2.1 2003/01/24 05:11:36 sam Exp $ */
   2 /*      $OpenBSD: ip_ipip.c,v 1.25 2002/06/10 18:04:55 itojun Exp $ */
   3 /*
   4  * The authors of this code are John Ioannidis (ji@tla.org),
   5  * Angelos D. Keromytis (kermit@csd.uch.gr) and
   6  * Niels Provos (provos@physnet.uni-hamburg.de).
   7  *
   8  * The original version of this code was written by John Ioannidis
   9  * for BSD/OS in Athens, Greece, in November 1995.
  10  *
  11  * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
  12  * by Angelos D. Keromytis.
  13  *
  14  * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
  15  * and Niels Provos.
  16  *
  17  * Additional features in 1999 by Angelos D. Keromytis.
  18  *
  19  * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
  20  * Angelos D. Keromytis and Niels Provos.
  21  * Copyright (c) 2001, Angelos D. Keromytis.
  22  *
  23  * Permission to use, copy, and modify this software with or without fee
  24  * is hereby granted, provided that this entire notice is included in
  25  * all copies of any software which is or includes a copy or
  26  * modification of this software.
  27  * You may use this code under the GNU public license if you so wish. Please
  28  * contribute changes back to the authors under this freer than GPL license
  29  * so that we may further the use of strong encryption without limitations to
  30  * all.
  31  *
  32  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
  33  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
  34  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
  35  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
  36  * PURPOSE.
  37  */
  38
  39 /*
  40  * IP-inside-IP processing
  41  */
  42 #include "opt_inet.h"
  43 #include "opt_inet6.h"
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/socket.h>
  49 #include <sys/kernel.h>
  50 #include <sys/protosw.h>
  51 #include <sys/sysctl.h>
  52
  53 #include <net/if.h>
  54 #include <net/route.h>
  55 #include <net/netisr.h>
  56 #include <net/raw_cb.h>
  57
  58 #include <netinet/in.h>
  59 #include <netinet/in_systm.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip.h>
  62 #include <netinet/ip_ecn.h>
  63 #include <netinet/ip_var.h>
  64 #include <netinet/ip_encap.h>
  65
  66 #include <netproto/ipsec/ipsec.h>
  67 #include <netproto/ipsec/xform.h>
  68
  69 #include <netproto/ipsec/ipip_var.h>
  70
  71 #ifdef MROUTING
  72 #include <netinet/ip_mroute.h>
  73 #endif
  74
  75 #ifdef INET6
  76 #include <netinet/ip6.h>
  77 #include <netproto/ipsec/ipsec6.h>
  78 #include <netinet6/ip6_ecn.h>
  79 #include <netinet6/in6_var.h>
  80 #include <netinet6/ip6protosw.h>
  81 #endif
  82
  83 #include <netproto/ipsec/key.h>
  84 #include <netproto/ipsec/key_debug.h>
  85
  86 #include <machine/stdarg.h>
  87
  88 typedef void    pr_in_input_t (struct mbuf *, int, int); /* XXX FIX THIS */
  89
  90 /*
  91  * We can control the acceptance of IP4 packets by altering the sysctl
  92  * net.inet.ipip.allow value.  Zero means drop them, all else is acceptance.
  93  */
  94 int     ipip_allow = 0;
  95 struct  ipipstat ipipstat;
  96
  97 SYSCTL_DECL(_net_inet_ipip);
  98 SYSCTL_INT(_net_inet_ipip, OID_AUTO,
  99         ipip_allow,     CTLFLAG_RW,     &ipip_allow,    0, "");
 100 SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS,
 101         stats,          CTLFLAG_RD,     &ipipstat,      ipipstat, "");
 102
 103 /* XXX IPCOMP */
 104 #define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
 105
 106 static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp);
 107
 108 #ifdef INET6
 109 /*
 110  * Really only a wrapper for ipip_input(), for use with IPv6.
 111  */
 112 int
 113 ip4_input6(struct mbuf **mp, int *offp, int proto)
 114 {
 115 #if 0
 116         /* If we do not accept IP-in-IP explicitly, drop.  */
 117         if (!ipip_allow && ((*m)->m_flags & M_IPSEC) == 0) {
 118                 DPRINTF(("ip4_input6: dropped due to policy\n"));
 119                 ipipstat.ipips_pdrops++;
 120                 m_freem(*m);
 121                 return IPPROTO_DONE;
 122         }
 123 #endif
 124         _ipip_input(*mp, *offp, NULL);
 125         return IPPROTO_DONE;
 126 }
 127 #endif /* INET6 */
 128
 129 #ifdef INET
 130 /*
 131  * Really only a wrapper for ipip_input(), for use with IPv4.
 132  */
 133 int
 134 ip4_input(struct mbuf **mp, int *offp, int proto)
 135 {
 136 #if 0
 137         /* If we do not accept IP-in-IP explicitly, drop.  */
 138         if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) {
 139                 DPRINTF(("ip4_input: dropped due to policy\n"));
 140                 ipipstat.ipips_pdrops++;
 141                 m_freem(m);
 142                 return;
 143         }
 144 #endif
 145         _ipip_input(*mp, *offp, NULL);
 146         return IPPROTO_DONE;
 147 }
 148 #endif /* INET */
 149
 150 /*
 151  * ipip_input gets called when we receive an IP{46} encapsulated packet,
 152  * either because we got it at a real interface, or because AH or ESP
 153  * were being used in tunnel mode (in which case the rcvif element will
 154  * contain the address of the encX interface associated with the tunnel.
 155  */
 156
 157 static void
 158 _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 159 {
 160         struct sockaddr_in *sin;
 161         struct ifaddr *ifa;
 162         struct ip *ipo;
 163 #ifdef INET6
 164         struct sockaddr_in6 *sin6;
 165         struct ip6_hdr *ip6 = NULL;
 166         u_int8_t itos;
 167 #endif
 168         u_int8_t nxt;
 169         int isr;
 170         u_int8_t otos;
 171         u_int8_t v;
 172         int hlen;
 173
 174         ipipstat.ipips_ipackets++;
 175
 176         m_copydata(m, 0, 1, &v);
 177
 178         switch (v >> 4) {
 179 #ifdef INET
 180         case 4:
 181                 hlen = sizeof(struct ip);
 182                 break;
 183 #endif /* INET */
 184 #ifdef INET6
 185         case 6:
 186                 hlen = sizeof(struct ip6_hdr);
 187                 break;
 188 #endif
 189         default:
 190                 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
 191                         "for outer header\n", v, v>>4));
 192                 ipipstat.ipips_family++;
 193                 m_freem(m);
 194                 return /* EAFNOSUPPORT */;
 195         }
 196
 197         /* Bring the IP header in the first mbuf, if not there already */
 198         if (m->m_len < hlen) {
 199                 if ((m = m_pullup(m, hlen)) == NULL) {
 200                         DPRINTF(("ipip_input: m_pullup (1) failed\n"));
 201                         ipipstat.ipips_hdrops++;
 202                         return;
 203                 }
 204         }
 205
 206         ipo = mtod(m, struct ip *);
 207
 208 #ifdef MROUTING
 209         if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) {
 210                 if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) {
 211                         ipip_mroute_input (m, iphlen);
 212                         return;
 213                 }
 214         }
 215 #endif /* MROUTING */
 216
 217         /* Keep outer ecn field. */
 218         switch (v >> 4) {
 219 #ifdef INET
 220         case 4:
 221                 otos = ipo->ip_tos;
 222                 break;
 223 #endif /* INET */
 224 #ifdef INET6
 225         case 6:
 226                 otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff;
 227                 break;
 228 #endif
 229         default:
 230                 panic("ipip_input: unknown ip version %u (outer)", v>>4);
 231         }
 232
 233         /* Remove outer IP header */
 234         m_adj(m, iphlen);
 235
 236         /* Sanity check */
 237         if (m->m_pkthdr.len < sizeof(struct ip))  {
 238                 ipipstat.ipips_hdrops++;
 239                 m_freem(m);
 240                 return;
 241         }
 242
 243         m_copydata(m, 0, 1, &v);
 244
 245         switch (v >> 4) {
 246 #ifdef INET
 247         case 4:
 248                 hlen = sizeof(struct ip);
 249                 break;
 250 #endif /* INET */
 251
 252 #ifdef INET6
 253         case 6:
 254                 hlen = sizeof(struct ip6_hdr);
 255                 break;
 256 #endif
 257         default:
 258                 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) "
 259                         "for inner header\n", v, v>>4));
 260                 ipipstat.ipips_family++;
 261                 m_freem(m);
 262                 return; /* EAFNOSUPPORT */
 263         }
 264
 265         /*
 266          * Bring the inner IP header in the first mbuf, if not there already.
 267          */
 268         if (m->m_len < hlen) {
 269                 if ((m = m_pullup(m, hlen)) == NULL) {
 270                         DPRINTF(("ipip_input: m_pullup (2) failed\n"));
 271                         ipipstat.ipips_hdrops++;
 272                         return;
 273                 }
 274         }
 275
 276         /*
 277          * RFC 1853 specifies that the inner TTL should not be touched on
 278          * decapsulation. There's no reason this comment should be here, but
 279          * this is as good as any a position.
 280          */
 281
 282         /* Some sanity checks in the inner IP header */
 283         switch (v >> 4) {
 284 #ifdef INET
 285         case 4:
 286                 ipo = mtod(m, struct ip *);
 287                 nxt = ipo->ip_p;
 288                 ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos);
 289                 break;
 290 #endif /* INET */
 291 #ifdef INET6
 292         case 6:
 293                 ip6 = (struct ip6_hdr *) ipo;
 294                 nxt = ip6->ip6_nxt;
 295                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 296                 ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos);
 297                 ip6->ip6_flow &= ~htonl(0xff << 20);
 298                 ip6->ip6_flow |= htonl((u_int32_t) itos << 20);
 299                 break;
 300 #endif
 301         default:
 302                 panic("ipip_input: unknown ip version %u (inner)", v>>4);
 303         }
 304
 305         /* Check for local address spoofing. */
 306         if ((m->m_pkthdr.rcvif == NULL ||
 307             !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) &&
 308             ipip_allow != 2) {
 309                 struct ifnet_array *arr;
 310                 int i;
 311
 312                 arr = ifnet_array_get();
 313                 for (i = 0; i < arr->ifnet_count; ++i) {
 314                         struct ifnet *ifp = arr->ifnet_arr[i];
 315                         struct ifaddr_container *ifac;
 316
 317                         TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
 318                                 ifa = ifac->ifa;
 319 #ifdef INET
 320                                 if (ipo) {
 321                                         if (ifa->ifa_addr->sa_family !=
 322                                             AF_INET)
 323                                                 continue;
 324
 325                                         sin = (struct sockaddr_in *) ifa->ifa_addr;
 326
 327                                         if (sin->sin_addr.s_addr ==
 328                                             ipo->ip_src.s_addr) {
 329                                                 ipipstat.ipips_spoof++;
 330                                                 m_freem(m);
 331                                                 return;
 332                                         }
 333                                 }
 334 #endif /* INET */
 335
 336 #ifdef INET6
 337                                 if (ip6) {
 338                                         if (ifa->ifa_addr->sa_family !=
 339                                             AF_INET6)
 340                                                 continue;
 341
 342                                         sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
 343
 344                                         if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) {
 345                                                 ipipstat.ipips_spoof++;
 346                                                 m_freem(m);
 347                                                 return;
 348                                         }
 349
 350                                 }
 351 #endif /* INET6 */
 352                         }
 353                 }
 354         }
 355
 356         /* Statistics */
 357         ipipstat.ipips_ibytes += m->m_pkthdr.len - iphlen;
 358
 359         /*
 360          * Interface pointer stays the same; if no IPsec processing has
 361          * been done (or will be done), this will point to a normal
 362          * interface. Otherwise, it'll point to an enc interface, which
 363          * will allow a packet filter to distinguish between secure and
 364          * untrusted packets.
 365          */
 366
 367         switch (v >> 4) {
 368 #ifdef INET
 369         case 4:
 370                 isr = NETISR_IP;
 371                 break;
 372 #endif
 373 #ifdef INET6
 374         case 6:
 375                 isr = NETISR_IPV6;
 376                 break;
 377 #endif
 378         default:
 379                 panic("ipip_input: should never reach here");
 380         }
 381
 382         if (netisr_queue(isr, m)) {
 383                 ipipstat.ipips_qfull++;
 384
 385                 DPRINTF(("ipip_input: packet dropped because of full queue\n"));
 386         }
 387 }
 388
 389 int
 390 ipip_output(
 391         struct mbuf *m,
 392         struct ipsecrequest *isr,
 393         struct mbuf **mp,
 394         int skip,
 395         int protoff
 396 )
 397 {
 398         struct secasvar *sav;
 399         u_int8_t tp, otos;
 400         struct secasindex *saidx;
 401         int error;
 402 #ifdef INET
 403         u_int8_t itos;
 404         struct ip *ipo;
 405 #endif /* INET */
 406 #ifdef INET6
 407         struct ip6_hdr *ip6, *ip6o;
 408 #endif /* INET6 */
 409
 410         sav = isr->sav;
 411         KASSERT(sav != NULL, ("ipip_output: null SA"));
 412         KASSERT(sav->sah != NULL, ("ipip_output: null SAH"));
 413
 414         /* XXX Deal with empty TDB source/destination addresses. */
 415
 416         m_copydata(m, 0, 1, &tp);
 417         tp = (tp >> 4) & 0xff;  /* Get the IP version number. */
 418
 419         saidx = &sav->sah->saidx;
 420         switch (saidx->dst.sa.sa_family) {
 421 #ifdef INET
 422         case AF_INET:
 423                 if (saidx->src.sa.sa_family != AF_INET ||
 424                     saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
 425                     saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) {
 426                         DPRINTF(("ipip_output: unspecified tunnel endpoint "
 427                             "address in SA %s/%08lx\n",
 428                             ipsec_address(&saidx->dst),
 429                             (u_long) ntohl(sav->spi)));
 430                         ipipstat.ipips_unspec++;
 431                         error = EINVAL;
 432                         goto bad;
 433                 }
 434
 435                 M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
 436                 if (m == NULL) {
 437                         DPRINTF(("ipip_output: M_PREPEND failed\n"));
 438                         ipipstat.ipips_hdrops++;
 439                         error = ENOBUFS;
 440                         goto bad;
 441                 }
 442
 443                 ipo = mtod(m, struct ip *);
 444
 445                 ipo->ip_v = IPVERSION;
 446                 ipo->ip_hl = 5;
 447                 ipo->ip_len = htons(m->m_pkthdr.len);
 448                 ipo->ip_ttl = ip_defttl;
 449                 ipo->ip_sum = 0;
 450                 ipo->ip_src = saidx->src.sin.sin_addr;
 451                 ipo->ip_dst = saidx->dst.sin.sin_addr;
 452
 453                 ipo->ip_id = ip_newid();
 454
 455                 /* If the inner protocol is IP... */
 456                 if (tp == IPVERSION) {
 457                         /* Save ECN notification */
 458                         m_copydata(m, sizeof(struct ip) +
 459                             offsetof(struct ip, ip_tos),
 460                             sizeof(u_int8_t), (caddr_t) &itos);
 461
 462                         ipo->ip_p = IPPROTO_IPIP;
 463
 464                         /*
 465                          * We should be keeping tunnel soft-state and
 466                          * send back ICMPs if needed.
 467                          */
 468                         m_copydata(m, sizeof(struct ip) +
 469                             offsetof(struct ip, ip_off),
 470                             sizeof(u_int16_t), (caddr_t) &ipo->ip_off);
 471                         ipo->ip_off = ntohs(ipo->ip_off);
 472                         ipo->ip_off &= ~(IP_DF | IP_MF | IP_OFFMASK);
 473                         ipo->ip_off = htons(ipo->ip_off);
 474                 }
 475 #ifdef INET6
 476                 else if (tp == (IPV6_VERSION >> 4)) {
 477                         u_int32_t itos32;
 478
 479                         /* Save ECN notification. */
 480                         m_copydata(m, sizeof(struct ip) +
 481                             offsetof(struct ip6_hdr, ip6_flow),
 482                             sizeof(u_int32_t), (caddr_t) &itos32);
 483                         itos = ntohl(itos32) >> 20;
 484                         ipo->ip_p = IPPROTO_IPV6;
 485                         ipo->ip_off = 0;
 486                 }
 487 #endif /* INET6 */
 488                 else {
 489                         goto nofamily;
 490                 }
 491
 492                 otos = 0;
 493                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 494                 ipo->ip_tos = otos;
 495                 break;
 496 #endif /* INET */
 497
 498 #ifdef INET6
 499         case AF_INET6:
 500                 if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) ||
 501                     saidx->src.sa.sa_family != AF_INET6 ||
 502                     IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) {
 503                         DPRINTF(("ipip_output: unspecified tunnel endpoint "
 504                             "address in SA %s/%08lx\n",
 505                             ipsec_address(&saidx->dst),
 506                             (u_long) ntohl(sav->spi)));
 507                         ipipstat.ipips_unspec++;
 508                         error = ENOBUFS;
 509                         goto bad;
 510                 }
 511
 512                 /* scoped address handling */
 513                 ip6 = mtod(m, struct ip6_hdr *);
 514                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
 515                         ip6->ip6_src.s6_addr16[1] = 0;
 516                 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
 517                         ip6->ip6_dst.s6_addr16[1] = 0;
 518
 519                 M_PREPEND(m, sizeof(struct ip6_hdr), M_NOWAIT);
 520                 if (m == NULL) {
 521                         DPRINTF(("ipip_output: M_PREPEND failed\n"));
 522                         ipipstat.ipips_hdrops++;
 523                         *mp = NULL;
 524                         error = ENOBUFS;
 525                         goto bad;
 526                 }
 527
 528                 /* Initialize IPv6 header */
 529                 ip6o = mtod(m, struct ip6_hdr *);
 530                 ip6o->ip6_flow = 0;
 531                 ip6o->ip6_vfc &= ~IPV6_VERSION_MASK;
 532                 ip6o->ip6_vfc |= IPV6_VERSION;
 533                 ip6o->ip6_plen = htons(m->m_pkthdr.len);
 534                 ip6o->ip6_hlim = ip_defttl;
 535                 ip6o->ip6_dst = saidx->dst.sin6.sin6_addr;
 536                 ip6o->ip6_src = saidx->src.sin6.sin6_addr;
 537
 538 #ifdef INET
 539                 if (tp == IPVERSION) {
 540                         /* Save ECN notification */
 541                         m_copydata(m, sizeof(struct ip6_hdr) +
 542                             offsetof(struct ip, ip_tos), sizeof(u_int8_t),
 543                             (caddr_t) &itos);
 544
 545                         /* This is really IPVERSION. */
 546                         ip6o->ip6_nxt = IPPROTO_IPIP;
 547                 } else
 548 #endif /* INET */
 549                         if (tp == (IPV6_VERSION >> 4)) {
 550                                 u_int32_t itos32;
 551
 552                                 /* Save ECN notification. */
 553                                 m_copydata(m, sizeof(struct ip6_hdr) +
 554                                     offsetof(struct ip6_hdr, ip6_flow),
 555                                     sizeof(u_int32_t), (caddr_t) &itos32);
 556                                 itos = ntohl(itos32) >> 20;
 557
 558                                 ip6o->ip6_nxt = IPPROTO_IPV6;
 559                         } else {
 560                                 goto nofamily;
 561                         }
 562
 563                 otos = 0;
 564                 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
 565                 ip6o->ip6_flow |= htonl((u_int32_t) otos << 20);
 566                 break;
 567 #endif /* INET6 */
 568
 569         default:
 570 nofamily:
 571                 DPRINTF(("ipip_output: unsupported protocol family %u\n",
 572                     saidx->dst.sa.sa_family));
 573                 ipipstat.ipips_family++;
 574                 error = EAFNOSUPPORT;           /* XXX diffs from openbsd */
 575                 goto bad;
 576         }
 577
 578         ipipstat.ipips_opackets++;
 579         *mp = m;
 580
 581 #ifdef INET
 582         if (saidx->dst.sa.sa_family == AF_INET) {
 583 #if 0
 584                 if (sav->tdb_xform->xf_type == XF_IP4)
 585                         tdb->tdb_cur_bytes +=
 586                             m->m_pkthdr.len - sizeof(struct ip);
 587 #endif
 588                 ipipstat.ipips_obytes += m->m_pkthdr.len - sizeof(struct ip);
 589         }
 590 #endif /* INET */
 591
 592 #ifdef INET6
 593         if (saidx->dst.sa.sa_family == AF_INET6) {
 594 #if 0
 595                 if (sav->tdb_xform->xf_type == XF_IP4)
 596                         tdb->tdb_cur_bytes +=
 597                             m->m_pkthdr.len - sizeof(struct ip6_hdr);
 598 #endif
 599                 ipipstat.ipips_obytes +=
 600                     m->m_pkthdr.len - sizeof(struct ip6_hdr);
 601         }
 602 #endif /* INET6 */
 603
 604         return 0;
 605 bad:
 606         if (m)
 607                 m_freem(m), *mp = NULL;
 608         return (error);
 609 }
 610
 611 #ifdef FAST_IPSEC
 612 static int
 613 ipe4_init(struct secasvar *sav, struct xformsw *xsp)
 614 {
 615         sav->tdb_xform = xsp;
 616         return 0;
 617 }
 618
 619 static int
 620 ipe4_zeroize(struct secasvar *sav)
 621 {
 622         sav->tdb_xform = NULL;
 623         return 0;
 624 }
 625
 626 static int
 627 ipe4_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 628 {
 629         /* This is a rather serious mistake, so no conditional printing. */
 630         kprintf("ipe4_input: should never be called\n");
 631         if (m)
 632                 m_freem(m);
 633         return EOPNOTSUPP;
 634 }
 635
 636 static struct xformsw ipe4_xformsw = {
 637         XF_IP4,         0,              "IPv4 Simple Encapsulation",
 638         ipe4_init,      ipe4_zeroize,   ipe4_input,     ipip_output,
 639 };
 640
 641 extern struct domain inetdomain;
 642
 643 static struct protosw ipe4_protosw[] = {
 644         {
 645                 .pr_type = SOCK_RAW,
 646                 .pr_domain = &inetdomain,
 647                 .pr_protocol = IPPROTO_IPV4,
 648                 .pr_flags = PR_ATOMIC|PR_ADDR,
 649
 650                 .pr_input = ip4_input,
 651                 .pr_output = NULL,
 652                 .pr_ctlinput = NULL,
 653                 .pr_ctloutput = rip_ctloutput,
 654
 655                 .pr_ctlport = cpu0_ctlport,
 656                 .pr_init = raw_init,
 657                 .pr_usrreqs = &rip_usrreqs
 658         },
 659 #ifdef INET6
 660         {
 661                 .pr_type = SOCK_RAW,
 662                 .pr_domain = &inetdomain,
 663                 .pr_protocol = IPPROTO_IPV6,
 664                 .pr_flags = PR_ATOMIC|PR_ADDR,
 665
 666                 .pr_input = ip4_input6,
 667                 .pr_output = NULL,
 668                 .pr_ctlinput = NULL,
 669                 .pr_ctloutput = rip_ctloutput,
 670
 671                 .pr_ctlport = cpu0_ctlport,
 672                 .pr_init = raw_init,
 673                 .pr_usrreqs = &rip_usrreqs
 674         }
 675 #endif
 676 };
 677
 678 /*
 679  * Check the encapsulated packet to see if we want it
 680  */
 681 static int
 682 ipe4_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
 683 {
 684         /*
 685          * Only take packets coming from IPSEC tunnels; the rest
 686          * must be handled by the gif tunnel code.  Note that we
 687          * also return a minimum priority when we want the packet
 688          * so any explicit gif tunnels take precedence.
 689          */
 690         return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0);
 691 }
 692
 693 static void
 694 ipe4_attach(void)
 695 {
 696         xform_register(&ipe4_xformsw);
 697         /* attach to encapsulation framework */
 698         /* XXX save return cookie for detach on module remove */
 699         encap_attach_func(AF_INET, -1,
 700                 ipe4_encapcheck, &ipe4_protosw[0], NULL);
 701 #ifdef INET6
 702         encap_attach_func(AF_INET6, -1,
 703                 ipe4_encapcheck, &ipe4_protosw[1], NULL);
 704 #endif
 705 }
 706 SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL);
 707 #endif  /* FAST_IPSEC */