1 /* $NetBSD: xform_ipip.c,v 1.12 2005/12/11 12:25:06 christos 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 1.12 2005/12/11 12:25:06 christos 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 # ifdef __FreeBSD__ 90 # include <netinet6/ip6_ecn.h> 91 # endif 92 #include <netinet6/in6_var.h> 93 #include <netinet6/ip6protosw.h> 94 #endif 95 96 #include <netipsec/key.h> 97 #include <netipsec/key_debug.h> 98 #include <netipsec/ipsec_osdep.h> 99 100 #include <machine/stdarg.h> 101 102 #ifdef __FreeBSD__ 103 typedef void pr_in_input_t (struct mbuf *, int, int); /* XXX FIX THIS */ 104 #else 105 typedef void pr_in_input_t (struct mbuf *m, ...); 106 #endif 107 108 /* 109 * We can control the acceptance of IP4 packets by altering the sysctl 110 * net.inet.ipip.allow value. Zero means drop them, all else is acceptance. 111 */ 112 int ipip_allow = 0; 113 struct ipipstat ipipstat; 114 115 #ifdef SYSCTL_DECL 116 SYSCTL_DECL(_net_inet_ipip); 117 118 SYSCTL_INT(_net_inet_ipip, OID_AUTO, 119 ipip_allow, CTLFLAG_RW, &ipip_allow, 0, ""); 120 SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS, 121 stats, CTLFLAG_RD, &ipipstat, ipipstat, ""); 122 123 #endif 124 125 #ifdef __FreeBSD__ 126 static 127 #endif 128 void ipe4_attach(void); 129 130 131 /* XXX IPCOMP */ 132 #define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED) 133 134 static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp); 135 136 #ifdef INET6 137 /* 138 * Really only a wrapper for ipip_input(), for use with IPv6. 139 */ 140 int 141 ip4_input6(struct mbuf **m, int *offp, int proto) 142 { 143 #if 0 144 /* If we do not accept IP-in-IP explicitly, drop. */ 145 if (!ipip_allow && ((*m)->m_flags & M_IPSEC) == 0) { 146 DPRINTF(("ip4_input6: dropped due to policy\n")); 147 ipipstat.ipips_pdrops++; 148 m_freem(*m); 149 return IPPROTO_DONE; 150 } 151 #endif 152 _ipip_input(*m, *offp, NULL); 153 return IPPROTO_DONE; 154 } 155 #endif /* INET6 */ 156 157 #ifdef INET 158 /* 159 * Really only a wrapper for ipip_input(), for use with IPv4. 160 */ 161 void 162 ip4_input(struct mbuf *m, ...) 163 { 164 va_list ap; 165 int iphlen; 166 167 #if 0 168 /* If we do not accept IP-in-IP explicitly, drop. */ 169 if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) { 170 DPRINTF(("ip4_input: dropped due to policy\n")); 171 ipipstat.ipips_pdrops++; 172 m_freem(m); 173 return; 174 } 175 #endif 176 va_start(ap, m); 177 iphlen = va_arg(ap, int); 178 va_end(ap); 179 180 _ipip_input(m, iphlen, NULL); 181 } 182 #endif /* INET */ 183 184 /* 185 * ipip_input gets called when we receive an IP{46} encapsulated packet, 186 * either because we got it at a real interface, or because AH or ESP 187 * were being used in tunnel mode (in which case the rcvif element will 188 * contain the address of the encX interface associated with the tunnel. 189 */ 190 191 static void 192 _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp) 193 { 194 register struct sockaddr_in *sin; 195 register struct ifnet *ifp; 196 register struct ifaddr *ifa; 197 struct ifqueue *ifq = NULL; 198 struct ip *ipo; 199 #ifdef INET6 200 register struct sockaddr_in6 *sin6; 201 struct ip6_hdr *ip6 = NULL; 202 u_int8_t itos; 203 #endif 204 u_int8_t nxt; 205 int isr; 206 u_int8_t otos; 207 u_int8_t v; 208 int hlen; 209 210 ipipstat.ipips_ipackets++; 211 212 m_copydata(m, 0, 1, &v); 213 214 switch (v >> 4) { 215 #ifdef INET 216 case 4: 217 hlen = sizeof(struct ip); 218 break; 219 #endif /* INET */ 220 #ifdef INET6 221 case 6: 222 hlen = sizeof(struct ip6_hdr); 223 break; 224 #endif 225 default: 226 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) " 227 "for outer header\n", v, v>>4)); 228 ipipstat.ipips_family++; 229 m_freem(m); 230 return /* EAFNOSUPPORT */; 231 } 232 233 /* Bring the IP header in the first mbuf, if not there already */ 234 if (m->m_len < hlen) { 235 if ((m = m_pullup(m, hlen)) == NULL) { 236 DPRINTF(("ipip_input: m_pullup (1) failed\n")); 237 ipipstat.ipips_hdrops++; 238 return; 239 } 240 } 241 242 ipo = mtod(m, struct ip *); 243 244 #ifdef MROUTING 245 if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) { 246 if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) { 247 ipip_mroute_input (m, iphlen); 248 return; 249 } 250 } 251 #endif /* MROUTING */ 252 253 /* Keep outer ecn field. */ 254 switch (v >> 4) { 255 #ifdef INET 256 case 4: 257 otos = ipo->ip_tos; 258 break; 259 #endif /* INET */ 260 #ifdef INET6 261 case 6: 262 otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff; 263 break; 264 #endif 265 default: 266 panic("ipip_input: unknown ip version %u (outer)", v>>4); 267 } 268 269 /* Remove outer IP header */ 270 m_adj(m, iphlen); 271 272 /* Sanity check */ 273 if (m->m_pkthdr.len < sizeof(struct ip)) { 274 ipipstat.ipips_hdrops++; 275 m_freem(m); 276 return; 277 } 278 279 m_copydata(m, 0, 1, &v); 280 281 switch (v >> 4) { 282 #ifdef INET 283 case 4: 284 hlen = sizeof(struct ip); 285 break; 286 #endif /* INET */ 287 288 #ifdef INET6 289 case 6: 290 hlen = sizeof(struct ip6_hdr); 291 break; 292 #endif 293 default: 294 DPRINTF(("_ipip_input: bad protocol version 0x%x (%u) " 295 "for inner header\n", v, v>>4)); 296 ipipstat.ipips_family++; 297 m_freem(m); 298 return; /* EAFNOSUPPORT */ 299 } 300 301 /* 302 * Bring the inner IP header in the first mbuf, if not there already. 303 */ 304 if (m->m_len < hlen) { 305 if ((m = m_pullup(m, hlen)) == NULL) { 306 DPRINTF(("ipip_input: m_pullup (2) failed\n")); 307 ipipstat.ipips_hdrops++; 308 return; 309 } 310 } 311 312 /* 313 * RFC 1853 specifies that the inner TTL should not be touched on 314 * decapsulation. There's no reason this comment should be here, but 315 * this is as good as any a position. 316 */ 317 318 /* Some sanity checks in the inner IP header */ 319 switch (v >> 4) { 320 #ifdef INET 321 case 4: 322 ipo = mtod(m, struct ip *); 323 nxt = ipo->ip_p; 324 ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos); 325 break; 326 #endif /* INET */ 327 #ifdef INET6 328 case 6: 329 ip6 = (struct ip6_hdr *) ipo; 330 nxt = ip6->ip6_nxt; 331 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 332 ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos); 333 ip6->ip6_flow &= ~htonl(0xff << 20); 334 ip6->ip6_flow |= htonl((u_int32_t) itos << 20); 335 break; 336 #endif 337 default: 338 panic("ipip_input: unknown ip version %u (inner)", v>>4); 339 } 340 341 /* Check for local address spoofing. */ 342 if ((m->m_pkthdr.rcvif == NULL || 343 !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) && 344 ipip_allow != 2) { 345 for (ifp = ifnet.tqh_first; ifp != 0; 346 ifp = ifp->if_list.tqe_next) { 347 for (ifa = ifp->if_addrlist.tqh_first; ifa != 0; 348 ifa = ifa->ifa_list.tqe_next) { 349 #ifdef INET 350 if (ipo) { 351 if (ifa->ifa_addr->sa_family != 352 AF_INET) 353 continue; 354 355 sin = (struct sockaddr_in *) ifa->ifa_addr; 356 357 if (sin->sin_addr.s_addr == 358 ipo->ip_src.s_addr) { 359 ipipstat.ipips_spoof++; 360 m_freem(m); 361 return; 362 } 363 } 364 #endif /* INET */ 365 366 #ifdef INET6 367 if (ip6) { 368 if (ifa->ifa_addr->sa_family != 369 AF_INET6) 370 continue; 371 372 sin6 = (struct sockaddr_in6 *) ifa->ifa_addr; 373 374 if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) { 375 ipipstat.ipips_spoof++; 376 m_freem(m); 377 return; 378 } 379 380 } 381 #endif /* INET6 */ 382 } 383 } 384 } 385 386 /* Statistics */ 387 ipipstat.ipips_ibytes += m->m_pkthdr.len - iphlen; 388 389 /* 390 * Interface pointer stays the same; if no IPsec processing has 391 * been done (or will be done), this will point to a normal 392 * interface. Otherwise, it'll point to an enc interface, which 393 * will allow a packet filter to distinguish between secure and 394 * untrusted packets. 395 */ 396 397 switch (v >> 4) { 398 #ifdef INET 399 case 4: 400 ifq = &ipintrq; 401 isr = NETISR_IP; 402 break; 403 #endif 404 #ifdef INET6 405 case 6: 406 ifq = &ip6intrq; 407 isr = NETISR_IPV6; 408 break; 409 #endif 410 default: 411 panic("ipip_input: should never reach here"); 412 } 413 414 if (!IF_HANDOFF(ifq, m, NULL)) { 415 ipipstat.ipips_qfull++; 416 417 DPRINTF(("ipip_input: packet dropped because of full queue\n")); 418 } else { 419 schednetisr(isr); 420 } 421 } 422 423 int 424 ipip_output( 425 struct mbuf *m, 426 struct ipsecrequest *isr, 427 struct mbuf **mp, 428 int skip, 429 int protoff 430 ) 431 { 432 struct secasvar *sav; 433 u_int8_t tp, otos; 434 struct secasindex *saidx; 435 int error; 436 #ifdef INET 437 u_int8_t itos; 438 struct ip *ipo; 439 #endif /* INET */ 440 #ifdef INET6 441 struct ip6_hdr *ip6, *ip6o; 442 #endif /* INET6 */ 443 444 IPSEC_SPLASSERT_SOFTNET("ipip_output"); 445 446 sav = isr->sav; 447 IPSEC_ASSERT(sav != NULL, ("ipip_output: null SA")); 448 IPSEC_ASSERT(sav->sah != NULL, ("ipip_output: null SAH")); 449 450 /* XXX Deal with empty TDB source/destination addresses. */ 451 452 m_copydata(m, 0, 1, &tp); 453 tp = (tp >> 4) & 0xff; /* Get the IP version number. */ 454 455 saidx = &sav->sah->saidx; 456 switch (saidx->dst.sa.sa_family) { 457 #ifdef INET 458 case AF_INET: 459 if (saidx->src.sa.sa_family != AF_INET || 460 saidx->src.sin.sin_addr.s_addr == INADDR_ANY || 461 saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) { 462 DPRINTF(("ipip_output: unspecified tunnel endpoint " 463 "address in SA %s/%08lx\n", 464 ipsec_address(&saidx->dst), 465 (u_long) ntohl(sav->spi))); 466 ipipstat.ipips_unspec++; 467 error = EINVAL; 468 goto bad; 469 } 470 471 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 472 if (m == 0) { 473 DPRINTF(("ipip_output: M_PREPEND failed\n")); 474 ipipstat.ipips_hdrops++; 475 error = ENOBUFS; 476 goto bad; 477 } 478 479 ipo = mtod(m, struct ip *); 480 481 ipo->ip_v = IPVERSION; 482 ipo->ip_hl = 5; 483 ipo->ip_len = htons(m->m_pkthdr.len); 484 ipo->ip_ttl = ip_defttl; 485 ipo->ip_sum = 0; 486 ipo->ip_src = saidx->src.sin.sin_addr; 487 ipo->ip_dst = saidx->dst.sin.sin_addr; 488 489 #if defined(__NetBSD__) 490 ipo->ip_id = ip_newid(); 491 #elif defined(RANDOM_IP_ID) 492 ipo->ip_id = ip_randomid(); 493 #else 494 ipo->ip_id = htons(ip_id++); 495 #endif 496 497 /* If the inner protocol is IP... */ 498 if (tp == IPVERSION) { 499 /* Save ECN notification */ 500 m_copydata(m, sizeof(struct ip) + 501 offsetof(struct ip, ip_tos), 502 sizeof(u_int8_t), (caddr_t) &itos); 503 504 ipo->ip_p = IPPROTO_IPIP; 505 506 /* 507 * We should be keeping tunnel soft-state and 508 * send back ICMPs if needed. 509 */ 510 m_copydata(m, sizeof(struct ip) + 511 offsetof(struct ip, ip_off), 512 sizeof(u_int16_t), (caddr_t) &ipo->ip_off); 513 ipo->ip_off = ntohs(ipo->ip_off); 514 ipo->ip_off &= ~(IP_DF | IP_MF | IP_OFFMASK); 515 ipo->ip_off = htons(ipo->ip_off); 516 } 517 #ifdef INET6 518 else if (tp == (IPV6_VERSION >> 4)) { 519 u_int32_t itos32; 520 521 /* Save ECN notification. */ 522 m_copydata(m, sizeof(struct ip) + 523 offsetof(struct ip6_hdr, ip6_flow), 524 sizeof(u_int32_t), (caddr_t) &itos32); 525 itos = ntohl(itos32) >> 20; 526 ipo->ip_p = IPPROTO_IPV6; 527 ipo->ip_off = 0; 528 } 529 #endif /* INET6 */ 530 else { 531 goto nofamily; 532 } 533 534 otos = 0; 535 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); 536 ipo->ip_tos = otos; 537 break; 538 #endif /* INET */ 539 540 #ifdef INET6 541 case AF_INET6: 542 if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) || 543 saidx->src.sa.sa_family != AF_INET6 || 544 IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) { 545 DPRINTF(("ipip_output: unspecified tunnel endpoint " 546 "address in SA %s/%08lx\n", 547 ipsec_address(&saidx->dst), 548 (u_long) ntohl(sav->spi))); 549 ipipstat.ipips_unspec++; 550 error = ENOBUFS; 551 goto bad; 552 } 553 554 /* scoped address handling */ 555 ip6 = mtod(m, struct ip6_hdr *); 556 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) 557 ip6->ip6_src.s6_addr16[1] = 0; 558 if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) 559 ip6->ip6_dst.s6_addr16[1] = 0; 560 561 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 562 if (m == 0) { 563 DPRINTF(("ipip_output: M_PREPEND failed\n")); 564 ipipstat.ipips_hdrops++; 565 error = ENOBUFS; 566 goto bad; 567 } 568 569 /* Initialize IPv6 header */ 570 ip6o = mtod(m, struct ip6_hdr *); 571 ip6o->ip6_flow = 0; 572 ip6o->ip6_vfc &= ~IPV6_VERSION_MASK; 573 ip6o->ip6_vfc |= IPV6_VERSION; 574 ip6o->ip6_plen = htons(m->m_pkthdr.len); 575 ip6o->ip6_hlim = ip_defttl; 576 ip6o->ip6_dst = saidx->dst.sin6.sin6_addr; 577 ip6o->ip6_src = saidx->src.sin6.sin6_addr; 578 579 #ifdef INET 580 if (tp == IPVERSION) { 581 /* Save ECN notification */ 582 m_copydata(m, sizeof(struct ip6_hdr) + 583 offsetof(struct ip, ip_tos), sizeof(u_int8_t), 584 (caddr_t) &itos); 585 586 /* This is really IPVERSION. */ 587 ip6o->ip6_nxt = IPPROTO_IPIP; 588 } else 589 #endif /* INET */ 590 if (tp == (IPV6_VERSION >> 4)) { 591 u_int32_t itos32; 592 593 /* Save ECN notification. */ 594 m_copydata(m, sizeof(struct ip6_hdr) + 595 offsetof(struct ip6_hdr, ip6_flow), 596 sizeof(u_int32_t), (caddr_t) &itos32); 597 itos = ntohl(itos32) >> 20; 598 599 ip6o->ip6_nxt = IPPROTO_IPV6; 600 } else { 601 goto nofamily; 602 } 603 604 otos = 0; 605 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); 606 ip6o->ip6_flow |= htonl((u_int32_t) otos << 20); 607 break; 608 #endif /* INET6 */ 609 610 default: 611 nofamily: 612 DPRINTF(("ipip_output: unsupported protocol family %u\n", 613 saidx->dst.sa.sa_family)); 614 ipipstat.ipips_family++; 615 error = EAFNOSUPPORT; /* XXX diffs from openbsd */ 616 goto bad; 617 } 618 619 ipipstat.ipips_opackets++; 620 *mp = m; 621 622 #ifdef INET 623 if (saidx->dst.sa.sa_family == AF_INET) { 624 #if 0 625 if (sav->tdb_xform->xf_type == XF_IP4) 626 tdb->tdb_cur_bytes += 627 m->m_pkthdr.len - sizeof(struct ip); 628 #endif 629 ipipstat.ipips_obytes += m->m_pkthdr.len - sizeof(struct ip); 630 } 631 #endif /* INET */ 632 633 #ifdef INET6 634 if (saidx->dst.sa.sa_family == AF_INET6) { 635 #if 0 636 if (sav->tdb_xform->xf_type == XF_IP4) 637 tdb->tdb_cur_bytes += 638 m->m_pkthdr.len - sizeof(struct ip6_hdr); 639 #endif 640 ipipstat.ipips_obytes += 641 m->m_pkthdr.len - sizeof(struct ip6_hdr); 642 } 643 #endif /* INET6 */ 644 645 return 0; 646 bad: 647 if (m) 648 m_freem(m); 649 *mp = NULL; 650 return (error); 651 } 652 653 #ifdef FAST_IPSEC 654 static int 655 ipe4_init(struct secasvar *sav, struct xformsw *xsp) 656 { 657 sav->tdb_xform = xsp; 658 return 0; 659 } 660 661 static int 662 ipe4_zeroize(struct secasvar *sav) 663 { 664 sav->tdb_xform = NULL; 665 return 0; 666 } 667 668 static int 669 ipe4_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 670 { 671 /* This is a rather serious mistake, so no conditional printing. */ 672 printf("ipe4_input: should never be called\n"); 673 if (m) 674 m_freem(m); 675 return EOPNOTSUPP; 676 } 677 678 static struct xformsw ipe4_xformsw = { 679 XF_IP4, 0, "IPv4 Simple Encapsulation", 680 ipe4_init, ipe4_zeroize, ipe4_input, ipip_output, 681 }; 682 683 extern struct domain inetdomain; 684 static struct ipprotosw ipe4_protosw[] = { 685 { SOCK_RAW, &inetdomain, IPPROTO_IPV4, PR_ATOMIC|PR_ADDR|PR_LASTHDR, 686 ip4_input, 0, 0, rip_ctloutput, 687 rip_usrreq, 688 0, 0, 0, 0, 689 }, 690 #ifdef INET6 691 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR|PR_LASTHDR, 692 ip4_input, 0, 0, rip_ctloutput, 693 rip_usrreq, 694 0, 0, 0, 0, 695 }, 696 #endif 697 }; 698 699 /* 700 * Check the encapsulated packet to see if we want it 701 */ 702 static int 703 ipe4_encapcheck(struct mbuf *m, int off, int proto, void *arg) 704 { 705 /* 706 * Only take packets coming from IPSEC tunnels; the rest 707 * must be handled by the gif tunnel code. Note that we 708 * also return a minimum priority when we want the packet 709 * so any explicit gif tunnels take precedence. 710 */ 711 return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0); 712 } 713 714 INITFN void 715 ipe4_attach(void) 716 { 717 xform_register(&ipe4_xformsw); 718 /* attach to encapsulation framework */ 719 /* XXX save return cookie for detach on module remove */ 720 (void) encap_attach_func(AF_INET, -1, 721 ipe4_encapcheck, (struct protosw*) &ipe4_protosw[0], NULL); 722 #ifdef INET6 723 (void) encap_attach_func(AF_INET6, -1, 724 ipe4_encapcheck, (struct protosw*) &ipe4_protosw[1], NULL); 725 #endif 726 } 727 728 #ifdef SYSINIT 729 SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL); 730 #endif 731 732 #endif /* FAST_IPSEC */ 733