1 /* $NetBSD: xform_ipip.c,v 1.8 2004/01/16 11:06:27 scw Exp $ */ 2 /* $FreeBSD: src/sys/netipsec/xform_ipip.c,v 1.3.2.1 2003/01/24 05:11:36 sam Exp $ */ 3 /* $OpenBSD: ip_ipip.c,v 1.25 2002/06/10 18:04:55 itojun Exp $ */ 4 5 /* 6 * The authors of this code are John Ioannidis (ji@tla.org), 7 * Angelos D. Keromytis (kermit@csd.uch.gr) and 8 * Niels Provos (provos@physnet.uni-hamburg.de). 9 * 10 * The original version of this code was written by John Ioannidis 11 * for BSD/OS in Athens, Greece, in November 1995. 12 * 13 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 14 * by Angelos D. Keromytis. 15 * 16 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 17 * and Niels Provos. 18 * 19 * Additional features in 1999 by Angelos D. Keromytis. 20 * 21 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 22 * Angelos D. Keromytis and Niels Provos. 23 * Copyright (c) 2001, Angelos D. Keromytis. 24 * 25 * Permission to use, copy, and modify this software with or without fee 26 * is hereby granted, provided that this entire notice is included in 27 * all copies of any software which is or includes a copy or 28 * modification of this software. 29 * You may use this code under the GNU public license if you so wish. Please 30 * contribute changes back to the authors under this freer than GPL license 31 * so that we may further the use of strong encryption without limitations to 32 * all. 33 * 34 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 35 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 36 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 37 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 38 * PURPOSE. 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: xform_ipip.c,v 1.8 2004/01/16 11:06:27 scw Exp $"); 43 44 /* 45 * IP-inside-IP processing 46 */ 47 #include "opt_inet.h" 48 #ifdef __FreeBSD__ 49 #include "opt_inet6.h" 50 #include "opt_random_ip_id.h" 51 #endif /* __FreeBSD__ */ 52 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/mbuf.h> 57 #include <sys/socket.h> 58 #include <sys/kernel.h> 59 #include <sys/protosw.h> 60 #include <sys/sysctl.h> 61 62 #include <net/if.h> 63 #include <net/route.h> 64 #include <net/netisr.h> 65 66 #include <netinet/in.h> 67 #include <netinet/in_systm.h> 68 #include <netinet/in_var.h> 69 #include <netinet/ip.h> 70 #include <netinet/ip_ecn.h> 71 #include <netinet/ip_var.h> 72 #include <netinet/ip_encap.h> 73 #ifdef __FreeBSD__ 74 #include <netinet/ipprotosw.h> 75 #endif 76 77 #include <netipsec/ipsec.h> 78 #include <netipsec/xform.h> 79 80 #include <netipsec/ipip_var.h> 81 82 #ifdef MROUTING 83 #include <netinet/ip_mroute.h> 84 #endif 85 86 #ifdef INET6 87 #include <netinet/ip6.h> 88 #include <netipsec/ipsec6.h> 89 #include <netinet6/ip6_ecn.h> 90 #include <netinet6/in6_var.h> 91 #include <netinet6/ip6protosw.h> 92 #endif 93 94 #include <netipsec/key.h> 95 #include <netipsec/key_debug.h> 96 #include <netipsec/ipsec_osdep.h> 97 98 #include <machine/stdarg.h> 99 100 #ifdef __FreeBSD__ 101 typedef void pr_in_input_t (struct mbuf *, int, int); /* XXX FIX THIS */ 102 #else 103 typedef void pr_in_input_t (struct mbuf *m, ...); 104 #endif 105 106 /* 107 * We can control the acceptance of IP4 packets by altering the sysctl 108 * net.inet.ipip.allow value. Zero means drop them, all else is acceptance. 109 */ 110 int ipip_allow = 0; 111 struct ipipstat ipipstat; 112 113 #ifdef SYSCTL_DECL 114 SYSCTL_DECL(_net_inet_ipip); 115 116 SYSCTL_INT(_net_inet_ipip, OID_AUTO, 117 ipip_allow, CTLFLAG_RW, &ipip_allow, 0, ""); 118 SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS, 119 stats, CTLFLAG_RD, &ipipstat, ipipstat, ""); 120 121 #endif 122 123 #ifdef __FreeBSD__ 124 static 125 #endif 126 void ipe4_attach(void); 127 128 129 /* XXX IPCOMP */ 130 #define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED) 131 132 static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp); 133 134 #ifdef INET6 135 /* 136 * Really only a wrapper for ipip_input(), for use with IPv6. 137 */ 138 int 139 ip4_input6(struct mbuf **m, int *offp, int proto) 140 { 141 #if 0 142 /* If we do not accept IP-in-IP explicitly, drop. */ 143 if (!ipip_allow && ((*m)->m_flags & M_IPSEC) == 0) { 144 DPRINTF(("ip4_input6: dropped due to policy\n")); 145 ipipstat.ipips_pdrops++; 146 m_freem(*m); 147 return IPPROTO_DONE; 148 } 149 #endif 150 _ipip_input(*m, *offp, NULL); 151 return IPPROTO_DONE; 152 } 153 #endif /* INET6 */ 154 155 #ifdef INET 156 /* 157 * Really only a wrapper for ipip_input(), for use with IPv4. 158 */ 159 void 160 ip4_input(struct mbuf *m, ...) 161 { 162 va_list ap; 163 int iphlen; 164 165 #if 0 166 /* If we do not accept IP-in-IP explicitly, drop. */ 167 if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) { 168 DPRINTF(("ip4_input: dropped due to policy\n")); 169 ipipstat.ipips_pdrops++; 170 m_freem(m); 171 return; 172 } 173 #endif 174 va_start(ap, m); 175 iphlen = va_arg(ap, int); 176 va_end(ap); 177 178 _ipip_input(m, iphlen, NULL); 179 } 180 #endif /* INET */ 181 182 /* 183 * ipip_input gets called when we receive an IP{46} encapsulated packet, 184 * either because we got it at a real interface, or because AH or ESP 185 * were being used in tunnel mode (in which case the rcvif element will 186 * contain the address of the encX interface associated with the tunnel. 187 */ 188 189 static void 190 _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp) 191 { 192 register struct sockaddr_in *sin; 193 register struct ifnet *ifp; 194 register struct ifaddr *ifa; 195 struct ifqueue *ifq = NULL; 196 struct ip *ipo; 197 #ifdef INET6 198 register struct sockaddr_in6 *sin6; 199 struct ip6_hdr *ip6 = NULL; 200 u_int8_t itos; 201 #endif 202 u_int8_t nxt; 203 int isr; 204 u_int8_t otos; 205 u_int8_t v; 206 int hlen; 207 208 ipipstat.ipips_ipackets++; 209 210 m_copydata(m, 0, 1, &v); 211 212 switch (v >> 4) { 213 #ifdef INET 214 case 4: 215 hlen = sizeof(struct ip); 216 break; 217 #endif /* INET */ 218 #ifdef INET6 219 case 6: 220 hlen = sizeof(struct ip6_hdr); 221 break; 222 #endif 223 default: 224 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) " 225 "for outer header\n", v, v>>4)); 226 ipipstat.ipips_family++; 227 m_freem(m); 228 return /* EAFNOSUPPORT */; 229 } 230 231 /* Bring the IP header in the first mbuf, if not there already */ 232 if (m->m_len < hlen) { 233 if ((m = m_pullup(m, hlen)) == NULL) { 234 DPRINTF(("ipip_input: m_pullup (1) failed\n")); 235 ipipstat.ipips_hdrops++; 236 return; 237 } 238 } 239 240 ipo = mtod(m, struct ip *); 241 242 #ifdef MROUTING 243 if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) { 244 if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) { 245 ipip_mroute_input (m, iphlen); 246 return; 247 } 248 } 249 #endif /* MROUTING */ 250 251 /* Keep outer ecn field. */ 252 switch (v >> 4) { 253 #ifdef INET 254 case 4: 255 otos = ipo->ip_tos; 256 break; 257 #endif /* INET */ 258 #ifdef INET6 259 case 6: 260 otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff; 261 break; 262 #endif 263 default: 264 panic("ipip_input: unknown ip version %u (outer)", v>>4); 265 } 266 267 /* Remove outer IP header */ 268 m_adj(m, iphlen); 269 270 /* Sanity check */ 271 if (m->m_pkthdr.len < sizeof(struct ip)) { 272 ipipstat.ipips_hdrops++; 273 m_freem(m); 274 return; 275 } 276 277 m_copydata(m, 0, 1, &v); 278 279 switch (v >> 4) { 280 #ifdef INET 281 case 4: 282 hlen = sizeof(struct ip); 283 break; 284 #endif /* INET */ 285 286 #ifdef INET6 287 case 6: 288 hlen = sizeof(struct ip6_hdr); 289 break; 290 #endif 291 default: 292 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) " 293 "for inner header\n", v, v>>4)); 294 ipipstat.ipips_family++; 295 m_freem(m); 296 return; /* EAFNOSUPPORT */ 297 } 298 299 /* 300 * Bring the inner IP header in the first mbuf, if not there already. 301 */ 302 if (m->m_len < hlen) { 303 if ((m = m_pullup(m, hlen)) == NULL) { 304 DPRINTF(("ipip_input: m_pullup (2) failed\n")); 305 ipipstat.ipips_hdrops++; 306 return; 307 } 308 } 309 310 /* 311 * RFC 1853 specifies that the inner TTL should not be touched on 312 * decapsulation. There's no reason this comment should be here, but 313 * this is as good as any a position. 314 */ 315 316 /* Some sanity checks in the inner IP header */ 317 switch (v >> 4) { 318 #ifdef INET 319 case 4: 320 ipo = mtod(m, struct ip *); 321 nxt = ipo->ip_p; 322 ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos); 323 break; 324 #endif /* INET */ 325 #ifdef INET6 326 case 6: 327 ip6 = (struct ip6_hdr *) ipo; 328 nxt = ip6->ip6_nxt; 329 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 330 ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos); 331 ip6->ip6_flow &= ~htonl(0xff << 20); 332 ip6->ip6_flow |= htonl((u_int32_t) itos << 20); 333 break; 334 #endif 335 default: 336 panic("ipip_input: unknown ip version %u (inner)", v>>4); 337 } 338 339 /* Check for local address spoofing. */ 340 if ((m->m_pkthdr.rcvif == NULL || 341 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) && 342 ipip_allow != 2) { 343 for (ifp = ifnet.tqh_first; ifp != 0; 344 ifp = ifp->if_list.tqe_next) { 345 for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; 346 ifa = ifa->ifa_list.tqe_next) { 347 #ifdef INET 348 if (ipo) { 349 if (ifa->ifa_addr->sa_family != 350 AF_INET) 351 continue; 352 353 sin = (struct sockaddr_in *) ifa->ifa_addr; 354 355 if (sin->sin_addr.s_addr == 356 ipo->ip_src.s_addr) { 357 ipipstat.ipips_spoof++; 358 m_freem(m); 359 return; 360 } 361 } 362 #endif /* INET */ 363 364 #ifdef INET6 365 if (ip6) { 366 if (ifa->ifa_addr->sa_family != 367 AF_INET6) 368 continue; 369 370 sin6 = (struct sockaddr_in6 *) ifa->ifa_addr; 371 372 if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) { 373 ipipstat.ipips_spoof++; 374 m_freem(m); 375 return; 376 } 377 378 } 379 #endif /* INET6 */ 380 } 381 } 382 } 383 384 /* Statistics */ 385 ipipstat.ipips_ibytes += m->m_pkthdr.len - iphlen; 386 387 /* 388 * Interface pointer stays the same; if no IPsec processing has 389 * been done (or will be done), this will point to a normal 390 * interface. Otherwise, it'll point to an enc interface, which 391 * will allow a packet filter to distinguish between secure and 392 * untrusted packets. 393 */ 394 395 switch (v >> 4) { 396 #ifdef INET 397 case 4: 398 ifq = &ipintrq; 399 isr = NETISR_IP; 400 break; 401 #endif 402 #ifdef INET6 403 case 6: 404 ifq = &ip6intrq; 405 isr = NETISR_IPV6; 406 break; 407 #endif 408 default: 409 panic("ipip_input: should never reach here"); 410 } 411 412 if (!IF_HANDOFF(ifq, m, NULL)) { 413 ipipstat.ipips_qfull++; 414 415 DPRINTF(("ipip_input: packet dropped because of full queue\n")); 416 } else { 417 schednetisr(isr); 418 } 419 } 420 421 int 422 ipip_output( 423 struct mbuf *m, 424 struct ipsecrequest *isr, 425 struct mbuf **mp, 426 int skip, 427 int protoff 428 ) 429 { 430 struct secasvar *sav; 431 u_int8_t tp, otos; 432 struct secasindex *saidx; 433 int error; 434 #ifdef INET 435 u_int8_t itos; 436 struct ip *ipo; 437 #endif /* INET */ 438 #ifdef INET6 439 struct ip6_hdr *ip6, *ip6o; 440 #endif /* INET6 */ 441 442 IPSEC_SPLASSERT_SOFTNET("ipip_output"); 443 444 sav = isr->sav; 445 IPSEC_ASSERT(sav != NULL, ("ipip_output: null SA")); 446 IPSEC_ASSERT(sav->sah != NULL, ("ipip_output: null SAH")); 447 448 /* XXX Deal with empty TDB source/destination addresses. */ 449 450 m_copydata(m, 0, 1, &tp); 451 tp = (tp >> 4) & 0xff; /* Get the IP version number. */ 452 453 saidx = &sav->sah->saidx; 454 switch (saidx->dst.sa.sa_family) { 455 #ifdef INET 456 case AF_INET: 457 if (saidx->src.sa.sa_family != AF_INET || 458 saidx->src.sin.sin_addr.s_addr == INADDR_ANY || 459 saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) { 460 DPRINTF(("ipip_output: unspecified tunnel endpoint " 461 "address in SA %s/%08lx\n", 462 ipsec_address(&saidx->dst), 463 (u_long) ntohl(sav->spi))); 464 ipipstat.ipips_unspec++; 465 error = EINVAL; 466 goto bad; 467 } 468 469 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 470 if (m == 0) { 471 DPRINTF(("ipip_output: M_PREPEND failed\n")); 472 ipipstat.ipips_hdrops++; 473 error = ENOBUFS; 474 goto bad; 475 } 476 477 ipo = mtod(m, struct ip *); 478 479 ipo->ip_v = IPVERSION; 480 ipo->ip_hl = 5; 481 ipo->ip_len = htons(m->m_pkthdr.len); 482 ipo->ip_ttl = ip_defttl; 483 ipo->ip_sum = 0; 484 ipo->ip_src = saidx->src.sin.sin_addr; 485 ipo->ip_dst = saidx->dst.sin.sin_addr; 486 487 #if defined(__NetBSD__) 488 ipo->ip_id = ip_newid(); 489 #elif defined(RANDOM_IP_ID) 490 ipo->ip_id = ip_randomid(); 491 #else 492 ipo->ip_id = htons(ip_id++); 493 #endif 494 495 /* If the inner protocol is IP... */ 496 if (tp == IPVERSION) { 497 /* Save ECN notification */ 498 m_copydata(m, sizeof(struct ip) + 499 offsetof(struct ip, ip_tos), 500 sizeof(u_int8_t), (caddr_t) &itos); 501 502 ipo->ip_p = IPPROTO_IPIP; 503 504 /* 505 * We should be keeping tunnel soft-state and 506 * send back ICMPs if needed. 507 */ 508 m_copydata(m, sizeof(struct ip) + 509 offsetof(struct ip, ip_off), 510 sizeof(u_int16_t), (caddr_t) &ipo->ip_off); 511 ipo->ip_off = ntohs(ipo->ip_off); 512 ipo->ip_off &= ~(IP_DF | IP_MF | IP_OFFMASK); 513 ipo->ip_off = htons(ipo->ip_off); 514 } 515 #ifdef INET6 516 else if (tp == (IPV6_VERSION >> 4)) { 517 u_int32_t itos32; 518 519 /* Save ECN notification. */ 520 m_copydata(m, sizeof(struct ip) + 521 offsetof(struct ip6_hdr, ip6_flow), 522 sizeof(u_int32_t), (caddr_t) &itos32); 523 itos = ntohl(itos32) >> 20; 524 ipo->ip_p = IPPROTO_IPV6; 525 ipo->ip_off = 0; 526 } 527 #endif /* INET6 */ 528 else { 529 goto nofamily; 530 } 531 532 otos = 0; 533 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); 534 ipo->ip_tos = otos; 535 break; 536 #endif /* INET */ 537 538 #ifdef INET6 539 case AF_INET6: 540 if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) || 541 saidx->src.sa.sa_family != AF_INET6 || 542 IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) { 543 DPRINTF(("ipip_output: unspecified tunnel endpoint " 544 "address in SA %s/%08lx\n", 545 ipsec_address(&saidx->dst), 546 (u_long) ntohl(sav->spi))); 547 ipipstat.ipips_unspec++; 548 error = ENOBUFS; 549 goto bad; 550 } 551 552 /* scoped address handling */ 553 ip6 = mtod(m, struct ip6_hdr *); 554 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 555 ip6->ip6_src.s6_addr16[1] = 0; 556 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 557 ip6->ip6_dst.s6_addr16[1] = 0; 558 559 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 560 if (m == 0) { 561 DPRINTF(("ipip_output: M_PREPEND failed\n")); 562 ipipstat.ipips_hdrops++; 563 error = ENOBUFS; 564 goto bad; 565 } 566 567 /* Initialize IPv6 header */ 568 ip6o = mtod(m, struct ip6_hdr *); 569 ip6o->ip6_flow = 0; 570 ip6o->ip6_vfc &= ~IPV6_VERSION_MASK; 571 ip6o->ip6_vfc |= IPV6_VERSION; 572 ip6o->ip6_plen = htons(m->m_pkthdr.len); 573 ip6o->ip6_hlim = ip_defttl; 574 ip6o->ip6_dst = saidx->dst.sin6.sin6_addr; 575 ip6o->ip6_src = saidx->src.sin6.sin6_addr; 576 577 #ifdef INET 578 if (tp == IPVERSION) { 579 /* Save ECN notification */ 580 m_copydata(m, sizeof(struct ip6_hdr) + 581 offsetof(struct ip, ip_tos), sizeof(u_int8_t), 582 (caddr_t) &itos); 583 584 /* This is really IPVERSION. */ 585 ip6o->ip6_nxt = IPPROTO_IPIP; 586 } else 587 #endif /* INET */ 588 if (tp == (IPV6_VERSION >> 4)) { 589 u_int32_t itos32; 590 591 /* Save ECN notification. */ 592 m_copydata(m, sizeof(struct ip6_hdr) + 593 offsetof(struct ip6_hdr, ip6_flow), 594 sizeof(u_int32_t), (caddr_t) &itos32); 595 itos = ntohl(itos32) >> 20; 596 597 ip6o->ip6_nxt = IPPROTO_IPV6; 598 } else { 599 goto nofamily; 600 } 601 602 otos = 0; 603 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); 604 ip6o->ip6_flow |= htonl((u_int32_t) otos << 20); 605 break; 606 #endif /* INET6 */ 607 608 default: 609 nofamily: 610 DPRINTF(("ipip_output: unsupported protocol family %u\n", 611 saidx->dst.sa.sa_family)); 612 ipipstat.ipips_family++; 613 error = EAFNOSUPPORT; /* XXX diffs from openbsd */ 614 goto bad; 615 } 616 617 ipipstat.ipips_opackets++; 618 *mp = m; 619 620 #ifdef INET 621 if (saidx->dst.sa.sa_family == AF_INET) { 622 #if 0 623 if (sav->tdb_xform->xf_type == XF_IP4) 624 tdb->tdb_cur_bytes += 625 m->m_pkthdr.len - sizeof(struct ip); 626 #endif 627 ipipstat.ipips_obytes += m->m_pkthdr.len - sizeof(struct ip); 628 } 629 #endif /* INET */ 630 631 #ifdef INET6 632 if (saidx->dst.sa.sa_family == AF_INET6) { 633 #if 0 634 if (sav->tdb_xform->xf_type == XF_IP4) 635 tdb->tdb_cur_bytes += 636 m->m_pkthdr.len - sizeof(struct ip6_hdr); 637 #endif 638 ipipstat.ipips_obytes += 639 m->m_pkthdr.len - sizeof(struct ip6_hdr); 640 } 641 #endif /* INET6 */ 642 643 return 0; 644 bad: 645 if (m) 646 m_freem(m); 647 *mp = NULL; 648 return (error); 649 } 650 651 #ifdef FAST_IPSEC 652 static int 653 ipe4_init(struct secasvar *sav, struct xformsw *xsp) 654 { 655 sav->tdb_xform = xsp; 656 return 0; 657 } 658 659 static int 660 ipe4_zeroize(struct secasvar *sav) 661 { 662 sav->tdb_xform = NULL; 663 return 0; 664 } 665 666 static int 667 ipe4_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 668 { 669 /* This is a rather serious mistake, so no conditional printing. */ 670 printf("ipe4_input: should never be called\n"); 671 if (m) 672 m_freem(m); 673 return EOPNOTSUPP; 674 } 675 676 static struct xformsw ipe4_xformsw = { 677 XF_IP4, 0, "IPv4 Simple Encapsulation", 678 ipe4_init, ipe4_zeroize, ipe4_input, ipip_output, 679 }; 680 681 extern struct domain inetdomain; 682 static struct ipprotosw ipe4_protosw[] = { 683 { SOCK_RAW, &inetdomain, IPPROTO_IPV4, PR_ATOMIC|PR_ADDR|PR_LASTHDR, 684 ip4_input, 0, 0, rip_ctloutput, 685 rip_usrreq, 686 0, 0, 0, 0, 687 }, 688 #ifdef INET6 689 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR|PR_LASTHDR, 690 ip4_input, 0, 0, rip_ctloutput, 691 rip_usrreq, 692 0, 0, 0, 0, 693 }, 694 #endif 695 }; 696 697 /* 698 * Check the encapsulated packet to see if we want it 699 */ 700 static int 701 ipe4_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 702 { 703 /* 704 * Only take packets coming from IPSEC tunnels; the rest 705 * must be handled by the gif tunnel code. Note that we 706 * also return a minimum priority when we want the packet 707 * so any explicit gif tunnels take precedence. 708 */ 709 return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0); 710 } 711 712 INITFN void 713 ipe4_attach(void) 714 { 715 xform_register(&ipe4_xformsw); 716 /* attach to encapsulation framework */ 717 /* XXX save return cookie for detach on module remove */ 718 (void) encap_attach_func(AF_INET, -1, 719 ipe4_encapcheck, (struct protosw*) &ipe4_protosw[0], NULL); 720 #ifdef INET6 721 (void) encap_attach_func(AF_INET6, -1, 722 ipe4_encapcheck, (struct protosw*) &ipe4_protosw[1], NULL); 723 #endif 724 } 725 726 #ifdef SYSINIT 727 SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL); 728 #endif 729 730 #endif /* FAST_IPSEC */ 731