1/* 2 * Copyright (c) 2000-2012 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); 178extern struct domain inetdomain; 179struct protosw in_stf_protosw = 180{ SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 181 in_stf_input, NULL, NULL, rip_ctloutput, 182 NULL, 183 NULL, NULL, NULL, NULL, 184 NULL, 185 &rip_usrreqs, 186 NULL, rip_unlock, NULL, {NULL, NULL}, NULL, {0} 187}; 188 189static int stf_encapcheck(const struct mbuf *, int, int, void *); 190static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 191int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **, 192 const struct sockaddr *, void *, char *, char *); 193static int stf_checkaddr4(struct stf_softc *, const struct in_addr *, 194 struct ifnet *); 195static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 196 struct ifnet *); 197static void stf_rtrequest(int, struct rtentry *, struct sockaddr *); 198static errno_t stf_ioctl(ifnet_t ifp, u_long cmd, void *data); 199static errno_t stf_output(ifnet_t ifp, mbuf_t m); 200 201static void 202stfinit(void) 203{ 204 if (!stf_init_done) { 205 stf_mtx_grp = lck_grp_alloc_init("stf", LCK_GRP_ATTR_NULL); 206 stf_init_done = 1; 207 } 208} 209 210/* 211 * gif_input is the input handler for IP and IPv6 attached to gif 212 */ 213static errno_t 214stf_media_input( 215 __unused ifnet_t ifp, 216 protocol_family_t protocol_family, 217 mbuf_t m, 218 __unused char *frame_header) 219{ 220 if (proto_input(protocol_family, m) != 0) 221 m_freem(m); 222 223 return (0); 224} 225 226 227 228static errno_t 229stf_add_proto( 230 ifnet_t ifp, 231 protocol_family_t protocol_family, 232 __unused const struct ifnet_demux_desc *demux_array, 233 __unused u_int32_t demux_count) 234{ 235 /* Only one protocol may be attached at a time */ 236 struct stf_softc* stf = ifnet_softc(ifp); 237 if (stf->sc_protocol_family == 0) 238 stf->sc_protocol_family = protocol_family; 239 else { 240 printf("stf_add_proto: stf already has a proto\n"); 241 return EBUSY; 242 } 243 244 return 0; 245} 246 247static errno_t 248stf_del_proto( 249 ifnet_t ifp, 250 protocol_family_t protocol_family) 251{ 252 if (((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family == protocol_family) 253 ((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family = 0; 254 255 return 0; 256} 257 258static errno_t 259stf_attach_inet6( 260 ifnet_t ifp, 261 protocol_family_t protocol_family) 262{ 263 struct ifnet_attach_proto_param reg; 264 errno_t stat; 265 266 if (protocol_family != PF_INET6) 267 return EPROTONOSUPPORT; 268 269 bzero(®, sizeof(reg)); 270 reg.input = stf_media_input; 271 reg.pre_output = stf_pre_output; 272 273 stat = ifnet_attach_protocol(ifp, protocol_family, ®); 274 if (stat && stat != EEXIST) { 275 printf("stf_attach_proto_family can't attach interface fam=%d\n", 276 protocol_family); 277 } 278 279 return stat; 280} 281 282static errno_t 283stf_demux( 284 ifnet_t ifp, 285 __unused mbuf_t m, 286 __unused char *frame_ptr, 287 protocol_family_t *protocol_family) 288{ 289 struct stf_softc* stf = ifnet_softc(ifp); 290 *protocol_family = stf->sc_protocol_family; 291 return 0; 292} 293 294static errno_t 295stf_set_bpf_tap( 296 ifnet_t ifp, 297 bpf_tap_mode mode, 298 bpf_packet_func callback) 299{ 300 struct stf_softc *sc = ifnet_softc(ifp); 301 302 sc->tap_mode = mode; 303 sc->tap_callback = callback; 304 305 return 0; 306} 307 308void 309stfattach(void) 310{ 311 struct stf_softc *sc; 312 int error; 313 const struct encaptab *p; 314 struct ifnet_init_params stf_init; 315 316 stfinit(); 317 318 error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF, 319 stf_attach_inet6, NULL); 320 if (error != 0) 321 printf("proto_register_plumber failed for AF_INET6 error=%d\n", error); 322 323 sc = _MALLOC(sizeof(struct stf_softc), M_DEVBUF, M_WAITOK); 324 if (sc == 0) { 325 printf("stf softc attach failed\n" ); 326 return; 327 } 328 329 bzero(sc, sizeof(*sc)); 330 331 p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, 332 &in_stf_protosw, sc); 333 if (p == NULL) { 334 printf("sftattach encap_attach_func failed\n"); 335 FREE(sc, M_DEVBUF); 336 return; 337 } 338 sc->encap_cookie = p; 339 lck_mtx_init(&sc->sc_ro_mtx, stf_mtx_grp, LCK_ATTR_NULL); 340 341 bzero(&stf_init, sizeof(stf_init)); 342 stf_init.name = "stf"; 343 stf_init.unit = 0; 344 stf_init.type = IFT_STF; 345 stf_init.family = IFNET_FAMILY_STF; 346 stf_init.output = stf_output; 347 stf_init.demux = stf_demux; 348 stf_init.add_proto = stf_add_proto; 349 stf_init.del_proto = stf_del_proto; 350 stf_init.softc = sc; 351 stf_init.ioctl = stf_ioctl; 352 stf_init.set_bpf_tap = stf_set_bpf_tap; 353 354 error = ifnet_allocate(&stf_init, &sc->sc_if); 355 if (error != 0) { 356 printf("stfattach, ifnet_allocate failed - %d\n", error); 357 encap_detach(sc->encap_cookie); 358 lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp); 359 FREE(sc, M_DEVBUF); 360 return; 361 } 362 ifnet_set_mtu(sc->sc_if, IPV6_MMTU); 363 ifnet_set_flags(sc->sc_if, 0, 0xffff); /* clear all flags */ 364#if 0 365 /* turn off ingress filter */ 366 ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2); 367#endif 368 369#if CONFIG_MACF_NET 370 mac_ifnet_label_init(&sc->sc_if); 371#endif 372 373 error = ifnet_attach(sc->sc_if, NULL); 374 if (error != 0) { 375 printf("stfattach: ifnet_attach returned error=%d\n", error); 376 encap_detach(sc->encap_cookie); 377 ifnet_release(sc->sc_if); 378 lck_mtx_destroy(&sc->sc_ro_mtx, stf_mtx_grp); 379 FREE(sc, M_DEVBUF); 380 return; 381 } 382 383 bpfattach(sc->sc_if, DLT_NULL, sizeof(u_int)); 384 385 return; 386} 387 388static int 389stf_encapcheck( 390 const struct mbuf *m, 391 __unused int off, 392 int proto, 393 void *arg) 394{ 395 struct ip ip; 396 struct in6_ifaddr *ia6; 397 struct stf_softc *sc; 398 struct in_addr a, b; 399 400 sc = (struct stf_softc *)arg; 401 if (sc == NULL) 402 return 0; 403 404 if ((ifnet_flags(sc->sc_if) & IFF_UP) == 0) 405 return 0; 406 407 /* IFF_LINK0 means "no decapsulation" */ 408 if ((ifnet_flags(sc->sc_if) & IFF_LINK0) != 0) 409 return 0; 410 411 if (proto != IPPROTO_IPV6) 412 return 0; 413 414 mbuf_copydata((struct mbuf *)(size_t)m, 0, sizeof(ip), &ip); 415 416 if (ip.ip_v != 4) 417 return 0; 418 419 ia6 = stf_getsrcifa6(sc->sc_if); 420 if (ia6 == NULL) 421 return 0; 422 423 /* 424 * check if IPv4 dst matches the IPv4 address derived from the 425 * local 6to4 address. 426 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 427 */ 428 IFA_LOCK(&ia6->ia_ifa); 429 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 430 sizeof(ip.ip_dst)) != 0) { 431 IFA_UNLOCK(&ia6->ia_ifa); 432 IFA_REMREF(&ia6->ia_ifa); 433 return 0; 434 } 435 /* 436 * check if IPv4 src matches the IPv4 address derived from the 437 * local 6to4 address masked by prefixmask. 438 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 439 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 440 */ 441 bzero(&a, sizeof(a)); 442 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 443 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 444 b = ip.ip_src; 445 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 446 if (a.s_addr != b.s_addr) { 447 IFA_UNLOCK(&ia6->ia_ifa); 448 IFA_REMREF(&ia6->ia_ifa); 449 return 0; 450 } 451 /* stf interface makes single side match only */ 452 IFA_UNLOCK(&ia6->ia_ifa); 453 IFA_REMREF(&ia6->ia_ifa); 454 return 32; 455} 456 457static struct in6_ifaddr * 458stf_getsrcifa6(struct ifnet *ifp) 459{ 460 struct ifaddr *ia; 461 struct in_ifaddr *ia4; 462 struct sockaddr_in6 *sin6; 463 struct in_addr in; 464 465 ifnet_lock_shared(ifp); 466 for (ia = ifp->if_addrlist.tqh_first; ia; ia = ia->ifa_list.tqe_next) { 467 IFA_LOCK(ia); 468 if (ia->ifa_addr == NULL) { 469 IFA_UNLOCK(ia); 470 continue; 471 } 472 if (ia->ifa_addr->sa_family != AF_INET6) { 473 IFA_UNLOCK(ia); 474 continue; 475 } 476 sin6 = (struct sockaddr_in6 *)(void *)ia->ifa_addr; 477 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 478 IFA_UNLOCK(ia); 479 continue; 480 } 481 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 482 IFA_UNLOCK(ia); 483 lck_rw_lock_shared(in_ifaddr_rwlock); 484 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 485 ia4; 486 ia4 = TAILQ_NEXT(ia4, ia_link)) 487 { 488 IFA_LOCK(&ia4->ia_ifa); 489 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) { 490 IFA_UNLOCK(&ia4->ia_ifa); 491 break; 492 } 493 IFA_UNLOCK(&ia4->ia_ifa); 494 } 495 lck_rw_done(in_ifaddr_rwlock); 496 if (ia4 == NULL) 497 continue; 498 499 IFA_ADDREF(ia); /* for caller */ 500 ifnet_lock_done(ifp); 501 return ((struct in6_ifaddr *)ia); 502 } 503 ifnet_lock_done(ifp); 504 505 return (NULL); 506} 507 508int 509stf_pre_output( 510 struct ifnet *ifp, 511 __unused protocol_family_t protocol_family, 512 struct mbuf **m0, 513 const struct sockaddr *dst, 514 __unused void *route, 515 __unused char *desk_linkaddr, 516 __unused char *frame_type) 517{ 518 struct mbuf *m = *m0; 519 struct stf_softc *sc; 520 const struct sockaddr_in6 *dst6; 521 const struct in_addr *in4; 522 u_int8_t tos; 523 struct ip *ip; 524 struct ip6_hdr *ip6; 525 struct in6_ifaddr *ia6; 526 struct sockaddr_in *dst4; 527 struct ip_out_args ipoa = { IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF }; 528 errno_t result = 0; 529 530 sc = ifnet_softc(ifp); 531 dst6 = (const struct sockaddr_in6 *)(const void *)dst; 532 533 /* just in case */ 534 if ((ifnet_flags(ifp) & IFF_UP) == 0) { 535 printf("stf: IFF_DOWN\n"); 536 return ENETDOWN; 537 } 538 539 /* 540 * If we don't have an ip4 address that match my inner ip6 address, 541 * we shouldn't generate output. Without this check, we'll end up 542 * using wrong IPv4 source. 543 */ 544 ia6 = stf_getsrcifa6(ifp); 545 if (ia6 == NULL) { 546 return ENETDOWN; 547 } 548 549 if (mbuf_len(m) < sizeof(*ip6)) { 550 m = m_pullup(m, sizeof(*ip6)); 551 if (!m) { 552 *m0 = NULL; /* makes sure this won't be double freed */ 553 IFA_REMREF(&ia6->ia_ifa); 554 return ENOBUFS; 555 } 556 } 557 ip6 = mtod(m, struct ip6_hdr *); 558 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 559 560 /* 561 * Pickup the right outer dst addr from the list of candidates. 562 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 563 */ 564 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 565 in4 = GET_V4(&ip6->ip6_dst); 566 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 567 in4 = GET_V4(&dst6->sin6_addr); 568 else { 569 IFA_REMREF(&ia6->ia_ifa); 570 return ENETUNREACH; 571 } 572 573 if (ifp->if_bpf) { 574 /* We need to prepend the address family as a four byte field. */ 575 u_int32_t af = AF_INET6; 576 577 bpf_tap_out(ifp, 0, m, &af, sizeof(af)); 578 } 579 580 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 581 if (m && mbuf_len(m) < sizeof(struct ip)) 582 m = m_pullup(m, sizeof(struct ip)); 583 if (m == NULL) { 584 *m0 = NULL; 585 IFA_REMREF(&ia6->ia_ifa); 586 return ENOBUFS; 587 } 588 ip = mtod(m, struct ip *); 589 590 bzero(ip, sizeof(*ip)); 591 592 IFA_LOCK_SPIN(&ia6->ia_ifa); 593 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 594 &ip->ip_src, sizeof(ip->ip_src)); 595 IFA_UNLOCK(&ia6->ia_ifa); 596 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 597 ip->ip_p = IPPROTO_IPV6; 598 ip->ip_ttl = ip_stf_ttl; 599 ip->ip_len = m->m_pkthdr.len; /*host order*/ 600 if (ifp->if_flags & IFF_LINK1) 601 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 602 else 603 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 604 605 lck_mtx_lock(&sc->sc_ro_mtx); 606 dst4 = (struct sockaddr_in *)(void *)&sc->sc_ro.ro_dst; 607 if (dst4->sin_family != AF_INET || 608 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 609 /* cache route doesn't match: always the case during the first use */ 610 dst4->sin_family = AF_INET; 611 dst4->sin_len = sizeof(struct sockaddr_in); 612 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 613 if (sc->sc_ro.ro_rt) { 614 rtfree(sc->sc_ro.ro_rt); 615 sc->sc_ro.ro_rt = NULL; 616 } 617 } 618 619 result = ip_output_list(m, 0, NULL, &sc->sc_ro, IP_OUTARGS, NULL, 620 &ipoa); 621 lck_mtx_unlock(&sc->sc_ro_mtx); 622 623 /* Assumption: ip_output will free mbuf on errors */ 624 /* All the output processing is done here, don't let stf_output be called */ 625 if (result == 0) 626 result = EJUSTRETURN; 627 *m0 = NULL; 628 IFA_REMREF(&ia6->ia_ifa); 629 return result; 630} 631static errno_t 632stf_output( 633 __unused ifnet_t ifp, 634 __unused mbuf_t m) 635{ 636 /* All processing is done in stf_pre_output 637 * this shouldn't be called as the pre_output returns "EJUSTRETURN" 638 */ 639 return 0; 640} 641 642static int 643stf_checkaddr4( 644 struct stf_softc *sc, 645 const struct in_addr *in, 646 struct ifnet *inifp) /* incoming interface */ 647{ 648 struct in_ifaddr *ia4; 649 650 /* 651 * reject packets with the following address: 652 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 653 */ 654 if (IN_MULTICAST(ntohl(in->s_addr))) 655 return -1; 656 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 657 case 0: case 127: case 255: 658 return -1; 659 } 660 661 /* 662 * reject packets with broadcast 663 */ 664 lck_rw_lock_shared(in_ifaddr_rwlock); 665 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 666 ia4; 667 ia4 = TAILQ_NEXT(ia4, ia_link)) 668 { 669 IFA_LOCK(&ia4->ia_ifa); 670 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) { 671 IFA_UNLOCK(&ia4->ia_ifa); 672 continue; 673 } 674 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 675 IFA_UNLOCK(&ia4->ia_ifa); 676 lck_rw_done(in_ifaddr_rwlock); 677 return -1; 678 } 679 IFA_UNLOCK(&ia4->ia_ifa); 680 } 681 lck_rw_done(in_ifaddr_rwlock); 682 683 /* 684 * perform ingress filter 685 */ 686 if (sc && (ifnet_flags(sc->sc_if) & IFF_LINK2) == 0 && inifp) { 687 struct sockaddr_in sin; 688 struct rtentry *rt; 689 690 bzero(&sin, sizeof(sin)); 691 sin.sin_family = AF_INET; 692 sin.sin_len = sizeof(struct sockaddr_in); 693 sin.sin_addr = *in; 694 rt = rtalloc1((struct sockaddr *)&sin, 0, 0); 695 if (rt != NULL) 696 RT_LOCK(rt); 697 if (rt == NULL || rt->rt_ifp != inifp) { 698#if 1 699 log(LOG_WARNING, "%s: packet from 0x%x dropped " 700 "due to ingress filter\n", if_name(sc->sc_if), 701 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 702#endif 703 if (rt != NULL) { 704 RT_UNLOCK(rt); 705 rtfree(rt); 706 } 707 return -1; 708 } 709 RT_UNLOCK(rt); 710 rtfree(rt); 711 } 712 713 return 0; 714} 715 716static int 717stf_checkaddr6( 718 struct stf_softc *sc, 719 struct in6_addr *in6, 720 struct ifnet *inifp) /* incoming interface */ 721{ 722 /* 723 * check 6to4 addresses 724 */ 725 if (IN6_IS_ADDR_6TO4(in6)) 726 return stf_checkaddr4(sc, GET_V4(in6), inifp); 727 728 /* 729 * reject anything that look suspicious. the test is implemented 730 * in ip6_input too, but we check here as well to 731 * (1) reject bad packets earlier, and 732 * (2) to be safe against future ip6_input change. 733 */ 734 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 735 return -1; 736 737 return 0; 738} 739 740static void 741in_stf_input( 742 struct mbuf *m, 743 int off) 744{ 745 struct stf_softc *sc; 746 struct ip *ip; 747 struct ip6_hdr ip6; 748 u_int8_t otos, itos; 749 int proto; 750 struct ifnet *ifp; 751 struct ifnet_stat_increment_param stats; 752 753 ip = mtod(m, struct ip *); 754 proto = ip->ip_p; 755 756 if (proto != IPPROTO_IPV6) { 757 m_freem(m); 758 return; 759 } 760 761 ip = mtod(m, struct ip *); 762 763 sc = (struct stf_softc *)encap_getarg(m); 764 765 if (sc == NULL || (ifnet_flags(sc->sc_if) & IFF_UP) == 0) { 766 m_freem(m); 767 return; 768 } 769 770 ifp = sc->sc_if; 771 772#if MAC_LABEL 773 mac_mbuf_label_associate_ifnet(ifp, m); 774#endif 775 776 /* 777 * perform sanity check against outer src/dst. 778 * for source, perform ingress filter as well. 779 */ 780 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 781 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 782 m_freem(m); 783 return; 784 } 785 786 otos = ip->ip_tos; 787 mbuf_copydata(m, off, sizeof(ip6), &ip6); 788 789 /* 790 * perform sanity check against inner src/dst. 791 * for source, perform ingress filter as well. 792 */ 793 if (stf_checkaddr6(sc, &ip6.ip6_dst, NULL) < 0 || 794 stf_checkaddr6(sc, &ip6.ip6_src, m->m_pkthdr.rcvif) < 0) { 795 m_freem(m); 796 return; 797 } 798 799 itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff; 800 if ((ifnet_flags(ifp) & IFF_LINK1) != 0) 801 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 802 else 803 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 804 ip6.ip6_flow &= ~htonl(0xff << 20); 805 ip6.ip6_flow |= htonl((u_int32_t)itos << 20); 806 807 m->m_pkthdr.rcvif = ifp; 808 mbuf_pkthdr_setheader(m, mbuf_data(m)); 809 mbuf_adj(m, off); 810 811 if (ifp->if_bpf) { 812 /* We need to prepend the address family as a four byte field. */ 813 u_int32_t af = AF_INET6; 814 bpf_tap_in(ifp, 0, m, &af, sizeof(af)); 815 } 816 817 /* 818 * Put the packet to the network layer input queue according to the 819 * specified address family. 820 * See net/if_gif.c for possible issues with packet processing 821 * reorder due to extra queueing. 822 */ 823 bzero(&stats, sizeof(stats)); 824 stats.packets_in = 1; 825 stats.bytes_in = mbuf_pkthdr_len(m); 826 mbuf_pkthdr_setrcvif(m, ifp); 827 ifnet_input(ifp, m, &stats); 828 829 return; 830} 831 832static void 833stf_rtrequest( 834 __unused int cmd, 835 struct rtentry *rt, 836 __unused struct sockaddr *sa) 837{ 838 if (rt != NULL) { 839 RT_LOCK_ASSERT_HELD(rt); 840 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 841 } 842} 843 844static errno_t 845stf_ioctl( 846 ifnet_t ifp, 847 u_long cmd, 848 void *data) 849{ 850 struct ifaddr *ifa; 851 struct ifreq *ifr; 852 struct sockaddr_in6 *sin6; 853 int error; 854 855 error = 0; 856 switch (cmd) { 857 case SIOCSIFADDR: 858 ifa = (struct ifaddr *)data; 859 if (ifa == NULL) { 860 error = EAFNOSUPPORT; 861 break; 862 } 863 IFA_LOCK(ifa); 864 if (ifa->ifa_addr->sa_family != AF_INET6) { 865 IFA_UNLOCK(ifa); 866 error = EAFNOSUPPORT; 867 break; 868 } 869 sin6 = (struct sockaddr_in6 *)(void *)ifa->ifa_addr; 870 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 871 if ( !(ifnet_flags( ifp ) & IFF_UP) ) { 872 /* do this only if the interface is not already up */ 873 ifa->ifa_rtrequest = stf_rtrequest; 874 IFA_UNLOCK(ifa); 875 ifnet_set_flags(ifp, IFF_UP, IFF_UP); 876 } else { 877 IFA_UNLOCK(ifa); 878 } 879 } else { 880 IFA_UNLOCK(ifa); 881 error = EINVAL; 882 } 883 IFA_LOCK_ASSERT_NOTHELD(ifa); 884 break; 885 886 case SIOCADDMULTI: 887 case SIOCDELMULTI: 888 ifr = (struct ifreq *)data; 889 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 890 ; 891 else 892 error = EAFNOSUPPORT; 893 break; 894 895 default: 896 error = EINVAL; 897 break; 898 } 899 900 return error; 901} 902