1/* 2 * Copyright (c) 2000-2013 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 29/* $FreeBSD: src/sys/net/if_stf.c,v 1.1.2.6 2001/07/24 19:10:18 brooks Exp $ */ 30/* $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun Exp $ */ 31 32/* 33 * Copyright (C) 2000 WIDE Project. 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 3. Neither the name of the project nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 */ 60/* 61 * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce 62 * support for mandatory and extensible security protections. This notice 63 * is included in support of clause 2.2 (b) of the Apple Public License, 64 * Version 2.0. 65 */ 66 67/* 68 * 6to4 interface, based on RFC3056. 69 * 70 * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting. 71 * There is no address mapping defined from IPv6 multicast address to IPv4 72 * address. Therefore, we do not have IFF_MULTICAST on the interface. 73 * 74 * Due to the lack of address mapping for link-local addresses, we cannot 75 * throw packets toward link-local addresses (fe80::x). Also, we cannot throw 76 * packets to link-local multicast addresses (ff02::x). 77 * 78 * Here are interesting symptoms due to the lack of link-local address: 79 * 80 * Unicast routing exchange: 81 * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9, 82 * and link-local addresses as nexthop. 83 * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address 84 * assigned to the link, and makes use of them. Also, HELLO packets use 85 * link-local multicast addresses (ff02::5 and ff02::6). 86 * - BGP4+: Maybe. You can only use global address as nexthop, and global 87 * address as TCP endpoint address. 88 * 89 * Multicast routing protocols: 90 * - PIM: Hello packet cannot be used to discover adjacent PIM routers. 91 * Adjacent PIM routers must be configured manually (is it really spec-wise 92 * correct thing to do?). 93 * 94 * ICMPv6: 95 * - Redirects cannot be used due to the lack of link-local address. 96 * 97 * stf interface does not have, and will not need, a link-local address. 98 * It seems to have no real benefit and does not help the above symptoms much. 99 * Even if we assign link-locals to interface, we cannot really 100 * use link-local unicast/multicast on top of 6to4 cloud (since there's no 101 * encapsulation defined for link-local address), and the above analysis does 102 * not change. RFC3056 does not mandate the assignment of link-local address 103 * either. 104 * 105 * 6to4 interface has security issues. Refer to 106 * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt 107 * for details. The code tries to filter out some of malicious packets. 108 * Note that there is no way to be 100% secure. 109 */ 110 111#include <sys/param.h> 112#include <sys/systm.h> 113#include <sys/socket.h> 114#include <sys/sockio.h> 115#include <sys/mbuf.h> 116#include <sys/errno.h> 117#include <sys/protosw.h> 118#include <sys/kernel.h> 119#include <sys/syslog.h> 120 121#include <sys/malloc.h> 122 123#include <kern/locks.h> 124 125#include <net/if.h> 126#include <net/route.h> 127#include <net/if_types.h> 128 129#include <netinet/in.h> 130#include <netinet/in_systm.h> 131#include <netinet/ip.h> 132#include <netinet/ip_var.h> 133#include <netinet/in_var.h> 134 135#include <netinet/ip6.h> 136#include <netinet6/ip6_var.h> 137#include <netinet6/in6_var.h> 138#include <netinet/ip_ecn.h> 139 140#include <netinet/ip_encap.h> 141#include <net/kpi_interface.h> 142#include <net/kpi_protocol.h> 143 144 145#include <net/net_osdep.h> 146 147#include <net/bpf.h> 148 149#if CONFIG_MACF_NET 150#include <security/mac_framework.h> 151#endif 152 153#define GET_V4(x) ((const struct in_addr *)(const void *)(&(x)->s6_addr16[1])) 154 155static lck_grp_t *stf_mtx_grp; 156 157struct stf_softc { 158 ifnet_t sc_if; /* common area */ 159 u_int32_t sc_protocol_family; /* dlil protocol attached */ 160 union { 161 struct route __sc_ro4; 162 struct route_in6 __sc_ro6; /* just for safety */ 163 } __sc_ro46; 164#define sc_ro __sc_ro46.__sc_ro4 165 decl_lck_mtx_data(, sc_ro_mtx); 166 const struct encaptab *encap_cookie; 167 bpf_tap_mode tap_mode; 168 bpf_packet_func tap_callback; 169}; 170 171void stfattach (void); 172 173static int ip_stf_ttl = 40; 174static int stf_init_done; 175 176static void in_stf_input(struct mbuf *, int); 177static void stfinit(void); 178 179static struct protosw in_stf_protosw = 180{ 181 .pr_type = SOCK_RAW, 182 .pr_protocol = IPPROTO_IPV6, 183 .pr_flags = PR_ATOMIC|PR_ADDR, 184 .pr_input = in_stf_input, 185 .pr_ctloutput = rip_ctloutput, 186 .pr_usrreqs = &rip_usrreqs, 187 .pr_unlock = rip_unlock, 188}; 189 190static int stf_encapcheck(const struct mbuf *, int, int, void *); 191static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 192int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **, 193 const struct sockaddr *, void *, char *, char *); 194static int stf_checkaddr4(struct stf_softc *, const struct in_addr *, 195 struct ifnet *); 196static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 197 struct ifnet *); 198static void stf_rtrequest(int, struct rtentry *, struct sockaddr *); 199static errno_t stf_ioctl(ifnet_t ifp, u_long cmd, void *data); 200static errno_t stf_output(ifnet_t ifp, mbuf_t m); 201 202static void 203stfinit(void) 204{ 205 if (!stf_init_done) { 206 stf_mtx_grp = lck_grp_alloc_init("stf", LCK_GRP_ATTR_NULL); 207 stf_init_done = 1; 208 } 209} 210 211/* 212 * gif_input is the input handler for IP and IPv6 attached to gif 213 */ 214static errno_t 215stf_media_input( 216 __unused ifnet_t ifp, 217 protocol_family_t protocol_family, 218 mbuf_t m, 219 __unused char *frame_header) 220{ 221 if (proto_input(protocol_family, m) != 0) 222 m_freem(m); 223 224 return (0); 225} 226 227 228 229static errno_t 230stf_add_proto( 231 ifnet_t ifp, 232 protocol_family_t protocol_family, 233 __unused const struct ifnet_demux_desc *demux_array, 234 __unused u_int32_t demux_count) 235{ 236 /* Only one protocol may be attached at a time */ 237 struct stf_softc* stf = ifnet_softc(ifp); 238 if (stf->sc_protocol_family == 0) 239 stf->sc_protocol_family = protocol_family; 240 else { 241 printf("stf_add_proto: stf already has a proto\n"); 242 return EBUSY; 243 } 244 245 return 0; 246} 247 248static errno_t 249stf_del_proto( 250 ifnet_t ifp, 251 protocol_family_t protocol_family) 252{ 253 if (((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family == protocol_family) 254 ((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family = 0; 255 256 return 0; 257} 258 259static errno_t 260stf_attach_inet6( 261 ifnet_t ifp, 262 protocol_family_t protocol_family) 263{ 264 struct ifnet_attach_proto_param reg; 265 errno_t stat; 266 267 if (protocol_family != PF_INET6) 268 return EPROTONOSUPPORT; 269 270 bzero(®, sizeof(reg)); 271 reg.input = stf_media_input; 272 reg.pre_output = stf_pre_output; 273 274 stat = ifnet_attach_protocol(ifp, protocol_family, ®); 275 if (stat && stat != EEXIST) { 276 printf("stf_attach_proto_family can't attach interface fam=%d\n", 277 protocol_family); 278 } 279 280 return stat; 281} 282 283static errno_t 284stf_demux( 285 ifnet_t ifp, 286 __unused mbuf_t m, 287 __unused char *frame_ptr, 288 protocol_family_t *protocol_family) 289{ 290 struct stf_softc* stf = ifnet_softc(ifp); 291 *protocol_family = stf->sc_protocol_family; 292 return 0; 293} 294 295static errno_t 296stf_set_bpf_tap( 297 ifnet_t ifp, 298 bpf_tap_mode mode, 299 bpf_packet_func callback) 300{ 301 struct stf_softc *sc = ifnet_softc(ifp); 302 303 sc->tap_mode = mode; 304 sc->tap_callback = callback; 305 306 return 0; 307} 308 309void 310stfattach(void) 311{ 312 struct stf_softc *sc; 313 int error; 314 const struct encaptab *p; 315 struct ifnet_init_params stf_init; 316 317 stfinit(); 318 319 error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF, 320 stf_attach_inet6, NULL); 321 if (error != 0) 322 printf("proto_register_plumber failed for AF_INET6 error=%d\n", error); 323 324 sc = _MALLOC(sizeof(struct stf_softc), M_DEVBUF, M_WAITOK); 325 if (sc == 0) { 326 printf("stf softc attach failed\n" ); 327 return; 328 } 329 330 bzero(sc, sizeof(*sc)); 331 332 p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, 333 &in_stf_protosw, sc); 334 if (p == NULL) { 335 printf("sftattach encap_attach_func failed\n"); 336 FREE(sc, M_DEVBUF); 337 return; 338 } 339 sc->encap_cookie = p; 340 lck_mtx_init(&sc->sc_ro_mtx, stf_mtx_grp, LCK_ATTR_NULL); 341 342 bzero(&stf_init, sizeof(stf_init)); 343 stf_init.name = "stf"; 344 stf_init.unit = 0; 345 stf_init.type = IFT_STF; 346 stf_init.family = IFNET_FAMILY_STF; 347 stf_init.output = stf_output; 348 stf_init.demux = stf_demux; 349 stf_init.add_proto = stf_add_proto; 350 stf_init.del_proto = stf_del_proto; 351 stf_init.softc = sc; 352 stf_init.ioctl = stf_ioctl; 353 stf_init.set_bpf_tap = stf_set_bpf_tap; 354 355 error = ifnet_allocate(&stf_init, &sc->sc_if); 356 if (error != 0) { 357 printf("stfattach, ifnet_allocate failed - %d\n", error); 358 encap_detach(sc->encap_cookie); 359 lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp); 360 FREE(sc, M_DEVBUF); 361 return; 362 } 363 ifnet_set_mtu(sc->sc_if, IPV6_MMTU); 364 ifnet_set_flags(sc->sc_if, 0, 0xffff); /* clear all flags */ 365#if 0 366 /* turn off ingress filter */ 367 ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2); 368#endif 369 370#if CONFIG_MACF_NET 371 mac_ifnet_label_init(&sc->sc_if); 372#endif 373 374 error = ifnet_attach(sc->sc_if, NULL); 375 if (error != 0) { 376 printf("stfattach: ifnet_attach returned error=%d\n", error); 377 encap_detach(sc->encap_cookie); 378 ifnet_release(sc->sc_if); 379 lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp); 380 FREE(sc, M_DEVBUF); 381 return; 382 } 383 384 bpfattach(sc->sc_if, DLT_NULL, sizeof(u_int)); 385 386 return; 387} 388 389static int 390stf_encapcheck( 391 const struct mbuf *m, 392 __unused int off, 393 int proto, 394 void *arg) 395{ 396 struct ip ip; 397 struct in6_ifaddr *ia6; 398 struct stf_softc *sc; 399 struct in_addr a, b; 400 401 sc = (struct stf_softc *)arg; 402 if (sc == NULL) 403 return 0; 404 405 if ((ifnet_flags(sc->sc_if) & IFF_UP) == 0) 406 return 0; 407 408 /* IFF_LINK0 means "no decapsulation" */ 409 if ((ifnet_flags(sc->sc_if) & IFF_LINK0) != 0) 410 return 0; 411 412 if (proto != IPPROTO_IPV6) 413 return 0; 414 415 mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip), &ip); 416 417 if (ip.ip_v != 4) 418 return 0; 419 420 ia6 = stf_getsrcifa6(sc->sc_if); 421 if (ia6 == NULL) 422 return 0; 423 424 /* 425 * check if IPv4 dst matches the IPv4 address derived from the 426 * local 6to4 address. 427 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 428 */ 429 IFA_LOCK(&ia6->ia_ifa); 430 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 431 sizeof(ip.ip_dst)) != 0) { 432 IFA_UNLOCK(&ia6->ia_ifa); 433 IFA_REMREF(&ia6->ia_ifa); 434 return 0; 435 } 436 /* 437 * check if IPv4 src matches the IPv4 address derived from the 438 * local 6to4 address masked by prefixmask. 439 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 440 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 441 */ 442 bzero(&a, sizeof(a)); 443 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 444 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 445 b = ip.ip_src; 446 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 447 if (a.s_addr != b.s_addr) { 448 IFA_UNLOCK(&ia6->ia_ifa); 449 IFA_REMREF(&ia6->ia_ifa); 450 return 0; 451 } 452 /* stf interface makes single side match only */ 453 IFA_UNLOCK(&ia6->ia_ifa); 454 IFA_REMREF(&ia6->ia_ifa); 455 return 32; 456} 457 458static struct in6_ifaddr * 459stf_getsrcifa6(struct ifnet *ifp) 460{ 461 struct ifaddr *ia; 462 struct in_ifaddr *ia4; 463 struct sockaddr_in6 *sin6; 464 struct in_addr in; 465 466 ifnet_lock_shared(ifp); 467 for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) { 468 IFA_LOCK(ia); 469 if (ia->ifa_addr == NULL) { 470 IFA_UNLOCK(ia); 471 continue; 472 } 473 if (ia->ifa_addr->sa_family != AF_INET6) { 474 IFA_UNLOCK(ia); 475 continue; 476 } 477 sin6 = (struct sockaddr_in6 *)(void *)ia->ifa_addr; 478 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 479 IFA_UNLOCK(ia); 480 continue; 481 } 482 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 483 IFA_UNLOCK(ia); 484 lck_rw_lock_shared(in_ifaddr_rwlock); 485 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 486 ia4; 487 ia4 = TAILQ_NEXT(ia4, ia_link)) 488 { 489 IFA_LOCK(&ia4->ia_ifa); 490 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) { 491 IFA_UNLOCK(&ia4->ia_ifa); 492 break; 493 } 494 IFA_UNLOCK(&ia4->ia_ifa); 495 } 496 lck_rw_done(in_ifaddr_rwlock); 497 if (ia4 == NULL) 498 continue; 499 500 IFA_ADDREF(ia); /* for caller */ 501 ifnet_lock_done(ifp); 502 return ((struct in6_ifaddr *)ia); 503 } 504 ifnet_lock_done(ifp); 505 506 return (NULL); 507} 508 509int 510stf_pre_output( 511 struct ifnet *ifp, 512 __unused protocol_family_t protocol_family, 513 struct mbuf **m0, 514 const struct sockaddr *dst, 515 __unused void *route, 516 __unused char *desk_linkaddr, 517 __unused char *frame_type) 518{ 519 struct mbuf *m = *m0; 520 struct stf_softc *sc; 521 const struct sockaddr_in6 *dst6; 522 const struct in_addr *in4; 523 u_int8_t tos; 524 struct ip *ip; 525 struct ip6_hdr *ip6; 526 struct in6_ifaddr *ia6; 527 struct sockaddr_in *dst4; 528 struct ip_out_args ipoa = 529 { IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF, 0 }; 530 errno_t result = 0; 531 532 sc = ifnet_softc(ifp); 533 dst6 = (const struct sockaddr_in6 *)(const void *)dst; 534 535 /* just in case */ 536 if ((ifnet_flags(ifp) & IFF_UP) == 0) { 537 printf("stf: IFF_DOWN\n"); 538 return ENETDOWN; 539 } 540 541 /* 542 * If we don't have an ip4 address that match my inner ip6 address, 543 * we shouldn't generate output. Without this check, we'll end up 544 * using wrong IPv4 source. 545 */ 546 ia6 = stf_getsrcifa6(ifp); 547 if (ia6 == NULL) { 548 return ENETDOWN; 549 } 550 551 if (mbuf_len(m) < sizeof(*ip6)) { 552 m = m_pullup(m, sizeof(*ip6)); 553 if (!m) { 554 *m0 = NULL; /* makes sure this won't be double freed */ 555 IFA_REMREF(&ia6->ia_ifa); 556 return ENOBUFS; 557 } 558 } 559 ip6 = mtod(m, struct ip6_hdr *); 560 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 561 562 /* 563 * Pickup the right outer dst addr from the list of candidates. 564 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 565 */ 566 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 567 in4 = GET_V4(&ip6->ip6_dst); 568 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 569 in4 = GET_V4(&dst6->sin6_addr); 570 else { 571 IFA_REMREF(&ia6->ia_ifa); 572 return ENETUNREACH; 573 } 574 575 if (ifp->if_bpf) { 576 /* We need to prepend the address family as a four byte field. */ 577 u_int32_t af = AF_INET6; 578 579 bpf_tap_out(ifp, 0, m, &af, sizeof(af)); 580 } 581 582 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 583 if (m && mbuf_len(m) < sizeof(struct ip)) 584 m = m_pullup(m, sizeof(struct ip)); 585 if (m == NULL) { 586 *m0 = NULL; 587 IFA_REMREF(&ia6->ia_ifa); 588 return ENOBUFS; 589 } 590 ip = mtod(m, struct ip *); 591 592 bzero(ip, sizeof(*ip)); 593 594 IFA_LOCK_SPIN(&ia6->ia_ifa); 595 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 596 &ip->ip_src, sizeof(ip->ip_src)); 597 IFA_UNLOCK(&ia6->ia_ifa); 598 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 599 ip->ip_p = IPPROTO_IPV6; 600 ip->ip_ttl = ip_stf_ttl; 601 ip->ip_len = m->m_pkthdr.len; /*host order*/ 602 if (ifp->if_flags & IFF_LINK1) 603 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 604 else 605 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 606 607 lck_mtx_lock(&sc->sc_ro_mtx); 608 dst4 = (struct sockaddr_in *)(void *)&sc->sc_ro.ro_dst; 609 if (ROUTE_UNUSABLE(&sc->sc_ro) || dst4->sin_family != AF_INET || 610 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 611 ROUTE_RELEASE(&sc->sc_ro); 612 /* cache route doesn't match: always the case during the first use */ 613 dst4->sin_family = AF_INET; 614 dst4->sin_len = sizeof(struct sockaddr_in); 615 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 616 } 617 618 result = ip_output(m, NULL, &sc->sc_ro, IP_OUTARGS, NULL, &ipoa); 619 lck_mtx_unlock(&sc->sc_ro_mtx); 620 621 /* Assumption: ip_output will free mbuf on errors */ 622 /* All the output processing is done here, don't let stf_output be called */ 623 if (result == 0) 624 result = EJUSTRETURN; 625 *m0 = NULL; 626 IFA_REMREF(&ia6->ia_ifa); 627 return result; 628} 629static errno_t 630stf_output( 631 __unused ifnet_t ifp, 632 __unused mbuf_t m) 633{ 634 /* All processing is done in stf_pre_output 635 * this shouldn't be called as the pre_output returns "EJUSTRETURN" 636 */ 637 return 0; 638} 639 640static int 641stf_checkaddr4( 642 struct stf_softc *sc, 643 const struct in_addr *in, 644 struct ifnet *inifp) /* incoming interface */ 645{ 646 struct in_ifaddr *ia4; 647 648 /* 649 * reject packets with the following address: 650 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 651 */ 652 if (IN_MULTICAST(ntohl(in->s_addr))) 653 return -1; 654 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 655 case 0: case 127: case 255: 656 return -1; 657 } 658 659 /* 660 * reject packets with broadcast 661 */ 662 lck_rw_lock_shared(in_ifaddr_rwlock); 663 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 664 ia4; 665 ia4 = TAILQ_NEXT(ia4, ia_link)) 666 { 667 IFA_LOCK(&ia4->ia_ifa); 668 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) { 669 IFA_UNLOCK(&ia4->ia_ifa); 670 continue; 671 } 672 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 673 IFA_UNLOCK(&ia4->ia_ifa); 674 lck_rw_done(in_ifaddr_rwlock); 675 return -1; 676 } 677 IFA_UNLOCK(&ia4->ia_ifa); 678 } 679 lck_rw_done(in_ifaddr_rwlock); 680 681 /* 682 * perform ingress filter 683 */ 684 if (sc && (ifnet_flags(sc->sc_if) & IFF_LINK2) == 0 && inifp) { 685 struct sockaddr_in sin; 686 struct rtentry *rt; 687 688 bzero(&sin, sizeof(sin)); 689 sin.sin_family = AF_INET; 690 sin.sin_len = sizeof(struct sockaddr_in); 691 sin.sin_addr = *in; 692 rt = rtalloc1((struct sockaddr *)&sin, 0, 0); 693 if (rt != NULL) 694 RT_LOCK(rt); 695 if (rt == NULL || rt->rt_ifp != inifp) { 696#if 1 697 log(LOG_WARNING, "%s: packet from 0x%x dropped " 698 "due to ingress filter\n", if_name(sc->sc_if), 699 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 700#endif 701 if (rt != NULL) { 702 RT_UNLOCK(rt); 703 rtfree(rt); 704 } 705 return -1; 706 } 707 RT_UNLOCK(rt); 708 rtfree(rt); 709 } 710 711 return 0; 712} 713 714static int 715stf_checkaddr6( 716 struct stf_softc *sc, 717 struct in6_addr *in6, 718 struct ifnet *inifp) /* incoming interface */ 719{ 720 /* 721 * check 6to4 addresses 722 */ 723 if (IN6_IS_ADDR_6TO4(in6)) 724 return stf_checkaddr4(sc, GET_V4(in6), inifp); 725 726 /* 727 * reject anything that look suspicious. the test is implemented 728 * in ip6_input too, but we check here as well to 729 * (1) reject bad packets earlier, and 730 * (2) to be safe against future ip6_input change. 731 */ 732 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 733 return -1; 734 735 return 0; 736} 737 738static void 739in_stf_input( 740 struct mbuf *m, 741 int off) 742{ 743 struct stf_softc *sc; 744 struct ip *ip; 745 struct ip6_hdr ip6; 746 u_int8_t otos, itos; 747 int proto; 748 struct ifnet *ifp; 749 struct ifnet_stat_increment_param stats; 750 751 ip = mtod(m, struct ip *); 752 proto = ip->ip_p; 753 754 if (proto != IPPROTO_IPV6) { 755 m_freem(m); 756 return; 757 } 758 759 ip = mtod(m, struct ip *); 760 761 sc = (struct stf_softc *)encap_getarg(m); 762 763 if (sc == NULL || (ifnet_flags(sc->sc_if) & IFF_UP) == 0) { 764 m_freem(m); 765 return; 766 } 767 768 ifp = sc->sc_if; 769 770#if MAC_LABEL 771 mac_mbuf_label_associate_ifnet(ifp, m); 772#endif 773 774 /* 775 * perform sanity check against outer src/dst. 776 * for source, perform ingress filter as well. 777 */ 778 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 779 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 780 m_freem(m); 781 return; 782 } 783 784 otos = ip->ip_tos; 785 mbuf_copydata(m, off, sizeof(ip6), &ip6); 786 787 /* 788 * perform sanity check against inner src/dst. 789 * for source, perform ingress filter as well. 790 */ 791 if (stf_checkaddr6(sc, &ip6.ip6_dst, NULL) < 0 || 792 stf_checkaddr6(sc, &ip6.ip6_src, m->m_pkthdr.rcvif) < 0) { 793 m_freem(m); 794 return; 795 } 796 797 itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff; 798 if ((ifnet_flags(ifp) & IFF_LINK1) != 0) 799 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 800 else 801 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 802 ip6.ip6_flow &= ~htonl(0xff << 20); 803 ip6.ip6_flow |= htonl((u_int32_t)itos << 20); 804 805 m->m_pkthdr.rcvif = ifp; 806 mbuf_pkthdr_setheader(m, mbuf_data(m)); 807 mbuf_adj(m, off); 808 809 if (ifp->if_bpf) { 810 /* We need to prepend the address family as a four byte field. */ 811 u_int32_t af = AF_INET6; 812 bpf_tap_in(ifp, 0, m, &af, sizeof(af)); 813 } 814 815 /* 816 * Put the packet to the network layer input queue according to the 817 * specified address family. 818 * See net/if_gif.c for possible issues with packet processing 819 * reorder due to extra queueing. 820 */ 821 bzero(&stats, sizeof(stats)); 822 stats.packets_in = 1; 823 stats.bytes_in = mbuf_pkthdr_len(m); 824 mbuf_pkthdr_setrcvif(m, ifp); 825 ifnet_input(ifp, m, &stats); 826 827 return; 828} 829 830static void 831stf_rtrequest( 832 __unused int cmd, 833 struct rtentry *rt, 834 __unused struct sockaddr *sa) 835{ 836 if (rt != NULL) { 837 RT_LOCK_ASSERT_HELD(rt); 838 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 839 } 840} 841 842static errno_t 843stf_ioctl( 844 ifnet_t ifp, 845 u_long cmd, 846 void *data) 847{ 848 struct ifaddr *ifa; 849 struct ifreq *ifr; 850 struct sockaddr_in6 *sin6; 851 int error; 852 853 error = 0; 854 switch (cmd) { 855 case SIOCSIFADDR: 856 ifa = (struct ifaddr *)data; 857 if (ifa == NULL) { 858 error = EAFNOSUPPORT; 859 break; 860 } 861 IFA_LOCK(ifa); 862 if (ifa->ifa_addr->sa_family != AF_INET6) { 863 IFA_UNLOCK(ifa); 864 error = EAFNOSUPPORT; 865 break; 866 } 867 sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr; 868 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 869 if ( !(ifnet_flags( ifp ) & IFF_UP) ) { 870 /* do this only if the interface is not already up */ 871 ifa->ifa_rtrequest = stf_rtrequest; 872 IFA_UNLOCK(ifa); 873 ifnet_set_flags(ifp, IFF_UP, IFF_UP); 874 } else { 875 IFA_UNLOCK(ifa); 876 } 877 } else { 878 IFA_UNLOCK(ifa); 879 error = EINVAL; 880 } 881 IFA_LOCK_ASSERT_NOTHELD(ifa); 882 break; 883 884 case SIOCADDMULTI: 885 case SIOCDELMULTI: 886 ifr = (struct ifreq *)data; 887 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 888 ; 889 else 890 error = EAFNOSUPPORT; 891 break; 892 893 default: 894 error = EOPNOTSUPP; 895 break; 896 } 897 898 return error; 899} 900