Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/net/if_stf.c
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1 /* $FreeBSD: releng/7.4/sys/net/if_stf.c 215368 2010-11-16 04:40:03Z sobomax $ */ 2 /* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */ 3 4 /*- 5 * Copyright (C) 2000 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * 6to4 interface, based on RFC3056. 35 * 36 * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting. 37 * There is no address mapping defined from IPv6 multicast address to IPv4 38 * address. Therefore, we do not have IFF_MULTICAST on the interface. 39 * 40 * Due to the lack of address mapping for link-local addresses, we cannot 41 * throw packets toward link-local addresses (fe80::x). Also, we cannot throw 42 * packets to link-local multicast addresses (ff02::x). 43 * 44 * Here are interesting symptoms due to the lack of link-local address: 45 * 46 * Unicast routing exchange: 47 * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9, 48 * and link-local addresses as nexthop. 49 * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address 50 * assigned to the link, and makes use of them. Also, HELLO packets use 51 * link-local multicast addresses (ff02::5 and ff02::6). 52 * - BGP4+: Maybe. You can only use global address as nexthop, and global 53 * address as TCP endpoint address. 54 * 55 * Multicast routing protocols: 56 * - PIM: Hello packet cannot be used to discover adjacent PIM routers. 57 * Adjacent PIM routers must be configured manually (is it really spec-wise 58 * correct thing to do?). 59 * 60 * ICMPv6: 61 * - Redirects cannot be used due to the lack of link-local address. 62 * 63 * stf interface does not have, and will not need, a link-local address. 64 * It seems to have no real benefit and does not help the above symptoms much. 65 * Even if we assign link-locals to interface, we cannot really 66 * use link-local unicast/multicast on top of 6to4 cloud (since there's no 67 * encapsulation defined for link-local address), and the above analysis does 68 * not change. RFC3056 does not mandate the assignment of link-local address 69 * either. 70 * 71 * 6to4 interface has security issues. Refer to 72 * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt 73 * for details. The code tries to filter out some of malicious packets. 74 * Note that there is no way to be 100% secure. 75 */ 76 77 #include "opt_inet.h" 78 #include "opt_inet6.h" 79 #include "opt_mac.h" 80 81 #include <sys/param.h> 82 #include <sys/systm.h> 83 #include <sys/socket.h> 84 #include <sys/sockio.h> 85 #include <sys/mbuf.h> 86 #include <sys/errno.h> 87 #include <sys/kernel.h> 88 #include <sys/module.h> 89 #include <sys/protosw.h> 90 #include <sys/proc.h> 91 #include <sys/queue.h> 92 #include <sys/sysctl.h> 93 #include <machine/cpu.h> 94 95 #include <sys/malloc.h> 96 97 #include <net/if.h> 98 #include <net/if_clone.h> 99 #include <net/route.h> 100 #include <net/netisr.h> 101 #include <net/if_types.h> 102 #include <net/if_stf.h> 103 104 #include <netinet/in.h> 105 #include <netinet/in_systm.h> 106 #include <netinet/ip.h> 107 #include <netinet/ip_var.h> 108 #include <netinet/in_var.h> 109 110 #include <netinet/ip6.h> 111 #include <netinet6/ip6_var.h> 112 #include <netinet6/in6_var.h> 113 #include <netinet/ip_ecn.h> 114 115 #include <netinet/ip_encap.h> 116 117 #include <machine/stdarg.h> 118 119 #include <net/bpf.h> 120 121 #include <security/mac/mac_framework.h> 122 123 SYSCTL_DECL(_net_link); 124 SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface"); 125 126 static int stf_route_cache = 1; 127 SYSCTL_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW, 128 &stf_route_cache, 0, "Caching of IPv4 routes for 6to4 Output"); 129 130 #define STFNAME "stf" 131 #define STFUNIT 0 132 133 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 134 135 /* 136 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 137 * struct in_addr *; use bcopy() instead. 138 */ 139 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 140 141 struct stf_softc { 142 struct ifnet *sc_ifp; 143 union { 144 struct route __sc_ro4; 145 struct route_in6 __sc_ro6; /* just for safety */ 146 } __sc_ro46; 147 #define sc_ro __sc_ro46.__sc_ro4 148 struct mtx sc_ro_mtx; 149 u_int sc_fibnum; 150 const struct encaptab *encap_cookie; 151 }; 152 #define STF2IFP(sc) ((sc)->sc_ifp) 153 154 /* 155 * Note that mutable fields in the softc are not currently locked. 156 * We do lock sc_ro in stf_output though. 157 */ 158 static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 159 static const int ip_stf_ttl = 40; 160 161 extern struct domain inetdomain; 162 struct protosw in_stf_protosw = { 163 .pr_type = SOCK_RAW, 164 .pr_domain = &inetdomain, 165 .pr_protocol = IPPROTO_IPV6, 166 .pr_flags = PR_ATOMIC|PR_ADDR, 167 .pr_input = in_stf_input, 168 .pr_output = (pr_output_t *)rip_output, 169 .pr_ctloutput = rip_ctloutput, 170 .pr_usrreqs = &rip_usrreqs 171 }; 172 173 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 174 175 static int stfmodevent(module_t, int, void *); 176 static int stf_encapcheck(const struct mbuf *, int, int, void *); 177 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 178 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 179 struct rtentry *); 180 static int isrfc1918addr(struct in_addr *); 181 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 182 struct ifnet *); 183 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 184 struct ifnet *); 185 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 186 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 187 188 static int stf_clone_match(struct if_clone *, const char *); 189 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 190 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 191 struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 192 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 193 194 static int 195 stf_clone_match(struct if_clone *ifc, const char *name) 196 { 197 int i; 198 199 for(i = 0; stfnames[i] != NULL; i++) { 200 if (strcmp(stfnames[i], name) == 0) 201 return (1); 202 } 203 204 return (0); 205 } 206 207 static int 208 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 209 { 210 int err, unit; 211 struct stf_softc *sc; 212 struct ifnet *ifp; 213 214 /* 215 * We can only have one unit, but since unit allocation is 216 * already locked, we use it to keep from allocating extra 217 * interfaces. 218 */ 219 unit = STFUNIT; 220 err = ifc_alloc_unit(ifc, &unit); 221 if (err != 0) 222 return (err); 223 224 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 225 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 226 if (ifp == NULL) { 227 free(sc, M_STF); 228 ifc_free_unit(ifc, unit); 229 return (ENOSPC); 230 } 231 ifp->if_softc = sc; 232 sc->sc_fibnum = curthread->td_proc->p_fibnum; 233 234 /* 235 * Set the name manually rather then using if_initname because 236 * we don't conform to the default naming convention for interfaces. 237 */ 238 strlcpy(ifp->if_xname, name, IFNAMSIZ); 239 ifp->if_dname = ifc->ifc_name; 240 ifp->if_dunit = IF_DUNIT_NONE; 241 242 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF); 243 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 244 stf_encapcheck, &in_stf_protosw, sc); 245 if (sc->encap_cookie == NULL) { 246 if_printf(ifp, "attach failed\n"); 247 free(sc, M_STF); 248 ifc_free_unit(ifc, unit); 249 return (ENOMEM); 250 } 251 252 ifp->if_mtu = IPV6_MMTU; 253 ifp->if_ioctl = stf_ioctl; 254 ifp->if_output = stf_output; 255 ifp->if_snd.ifq_maxlen = ifqmaxlen; 256 if_attach(ifp); 257 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 258 return (0); 259 } 260 261 static int 262 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 263 { 264 struct stf_softc *sc = ifp->if_softc; 265 int err; 266 267 err = encap_detach(sc->encap_cookie); 268 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 269 mtx_destroy(&(sc)->sc_ro_mtx); 270 bpfdetach(ifp); 271 if_detach(ifp); 272 if_free(ifp); 273 274 free(sc, M_STF); 275 ifc_free_unit(ifc, STFUNIT); 276 277 return (0); 278 } 279 280 static int 281 stfmodevent(mod, type, data) 282 module_t mod; 283 int type; 284 void *data; 285 { 286 287 switch (type) { 288 case MOD_LOAD: 289 if_clone_attach(&stf_cloner); 290 break; 291 case MOD_UNLOAD: 292 if_clone_detach(&stf_cloner); 293 break; 294 default: 295 return (EOPNOTSUPP); 296 } 297 298 return (0); 299 } 300 301 static moduledata_t stf_mod = { 302 "if_stf", 303 stfmodevent, 304 0 305 }; 306 307 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 308 309 static int 310 stf_encapcheck(m, off, proto, arg) 311 const struct mbuf *m; 312 int off; 313 int proto; 314 void *arg; 315 { 316 struct ip ip; 317 struct in6_ifaddr *ia6; 318 struct stf_softc *sc; 319 struct in_addr a, b, mask; 320 321 sc = (struct stf_softc *)arg; 322 if (sc == NULL) 323 return 0; 324 325 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 326 return 0; 327 328 /* IFF_LINK0 means "no decapsulation" */ 329 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 330 return 0; 331 332 if (proto != IPPROTO_IPV6) 333 return 0; 334 335 /* LINTED const cast */ 336 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 337 338 if (ip.ip_v != 4) 339 return 0; 340 341 ia6 = stf_getsrcifa6(STF2IFP(sc)); 342 if (ia6 == NULL) 343 return 0; 344 345 /* 346 * check if IPv4 dst matches the IPv4 address derived from the 347 * local 6to4 address. 348 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 349 */ 350 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 351 sizeof(ip.ip_dst)) != 0) 352 return 0; 353 354 /* 355 * check if IPv4 src matches the IPv4 address derived from the 356 * local 6to4 address masked by prefixmask. 357 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 358 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 359 */ 360 bzero(&a, sizeof(a)); 361 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 362 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 363 a.s_addr &= mask.s_addr; 364 b = ip.ip_src; 365 b.s_addr &= mask.s_addr; 366 if (a.s_addr != b.s_addr) 367 return 0; 368 369 /* stf interface makes single side match only */ 370 return 32; 371 } 372 373 static struct in6_ifaddr * 374 stf_getsrcifa6(ifp) 375 struct ifnet *ifp; 376 { 377 struct ifaddr *ia; 378 struct in_ifaddr *ia4; 379 struct sockaddr_in6 *sin6; 380 struct in_addr in; 381 382 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) { 383 if (ia->ifa_addr->sa_family != AF_INET6) 384 continue; 385 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 386 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 387 continue; 388 389 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 390 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 391 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 392 break; 393 if (ia4 == NULL) 394 continue; 395 396 return (struct in6_ifaddr *)ia; 397 } 398 399 return NULL; 400 } 401 402 static int 403 stf_output(ifp, m, dst, rt) 404 struct ifnet *ifp; 405 struct mbuf *m; 406 struct sockaddr *dst; 407 struct rtentry *rt; 408 { 409 struct stf_softc *sc; 410 struct sockaddr_in6 *dst6; 411 struct route *cached_route; 412 struct in_addr in4; 413 caddr_t ptr; 414 struct sockaddr_in *dst4; 415 u_int8_t tos; 416 struct ip *ip; 417 struct ip6_hdr *ip6; 418 struct in6_ifaddr *ia6; 419 u_int32_t af; 420 int error; 421 422 #ifdef MAC 423 error = mac_check_ifnet_transmit(ifp, m); 424 if (error) { 425 m_freem(m); 426 return (error); 427 } 428 #endif 429 430 sc = ifp->if_softc; 431 dst6 = (struct sockaddr_in6 *)dst; 432 433 /* just in case */ 434 if ((ifp->if_flags & IFF_UP) == 0) { 435 m_freem(m); 436 ifp->if_oerrors++; 437 return ENETDOWN; 438 } 439 440 /* 441 * If we don't have an ip4 address that match my inner ip6 address, 442 * we shouldn't generate output. Without this check, we'll end up 443 * using wrong IPv4 source. 444 */ 445 ia6 = stf_getsrcifa6(ifp); 446 if (ia6 == NULL) { 447 m_freem(m); 448 ifp->if_oerrors++; 449 return ENETDOWN; 450 } 451 452 if (m->m_len < sizeof(*ip6)) { 453 m = m_pullup(m, sizeof(*ip6)); 454 if (!m) { 455 ifp->if_oerrors++; 456 return ENOBUFS; 457 } 458 } 459 ip6 = mtod(m, struct ip6_hdr *); 460 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 461 462 /* 463 * BPF writes need to be handled specially. 464 * This is a null operation, nothing here checks dst->sa_family. 465 */ 466 if (dst->sa_family == AF_UNSPEC) { 467 bcopy(dst->sa_data, &af, sizeof(af)); 468 dst->sa_family = af; 469 } 470 471 /* 472 * Pickup the right outer dst addr from the list of candidates. 473 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 474 */ 475 ptr = NULL; 476 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 477 ptr = GET_V4(&ip6->ip6_dst); 478 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 479 ptr = GET_V4(&dst6->sin6_addr); 480 else { 481 m_freem(m); 482 ifp->if_oerrors++; 483 return ENETUNREACH; 484 } 485 bcopy(ptr, &in4, sizeof(in4)); 486 487 if (bpf_peers_present(ifp->if_bpf)) { 488 /* 489 * We need to prepend the address family as 490 * a four byte field. Cons up a dummy header 491 * to pacify bpf. This is safe because bpf 492 * will only read from the mbuf (i.e., it won't 493 * try to free it or keep a pointer a to it). 494 */ 495 af = AF_INET6; 496 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 497 } 498 499 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 500 if (m && m->m_len < sizeof(struct ip)) 501 m = m_pullup(m, sizeof(struct ip)); 502 if (m == NULL) { 503 ifp->if_oerrors++; 504 return ENOBUFS; 505 } 506 ip = mtod(m, struct ip *); 507 508 bzero(ip, sizeof(*ip)); 509 510 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 511 &ip->ip_src, sizeof(ip->ip_src)); 512 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 513 ip->ip_p = IPPROTO_IPV6; 514 ip->ip_ttl = ip_stf_ttl; 515 ip->ip_len = m->m_pkthdr.len; /*host order*/ 516 if (ifp->if_flags & IFF_LINK1) 517 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 518 else 519 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 520 521 if (!stf_route_cache) { 522 cached_route = NULL; 523 goto sendit; 524 } 525 526 /* 527 * Do we have a cached route? 528 */ 529 mtx_lock(&(sc)->sc_ro_mtx); 530 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 531 if (dst4->sin_family != AF_INET || 532 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 533 /* cache route doesn't match */ 534 dst4->sin_family = AF_INET; 535 dst4->sin_len = sizeof(struct sockaddr_in); 536 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 537 if (sc->sc_ro.ro_rt) { 538 RTFREE(sc->sc_ro.ro_rt); 539 sc->sc_ro.ro_rt = NULL; 540 } 541 } 542 543 if (sc->sc_ro.ro_rt == NULL) { 544 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 545 if (sc->sc_ro.ro_rt == NULL) { 546 m_freem(m); 547 mtx_unlock(&(sc)->sc_ro_mtx); 548 ifp->if_oerrors++; 549 return ENETUNREACH; 550 } 551 } 552 cached_route = &sc->sc_ro; 553 554 sendit: 555 M_SETFIB(m, sc->sc_fibnum); 556 ifp->if_opackets++; 557 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 558 559 if (cached_route != NULL) 560 mtx_unlock(&(sc)->sc_ro_mtx); 561 return error; 562 } 563 564 static int 565 isrfc1918addr(in) 566 struct in_addr *in; 567 { 568 /* 569 * returns 1 if private address range: 570 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 571 */ 572 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 573 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 574 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 575 return 1; 576 577 return 0; 578 } 579 580 static int 581 stf_checkaddr4(sc, in, inifp) 582 struct stf_softc *sc; 583 struct in_addr *in; 584 struct ifnet *inifp; /* incoming interface */ 585 { 586 struct in_ifaddr *ia4; 587 588 /* 589 * reject packets with the following address: 590 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 591 */ 592 if (IN_MULTICAST(ntohl(in->s_addr))) 593 return -1; 594 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 595 case 0: case 127: case 255: 596 return -1; 597 } 598 599 /* 600 * reject packets with private address range. 601 * (requirement from RFC3056 section 2 1st paragraph) 602 */ 603 if (isrfc1918addr(in)) 604 return -1; 605 606 /* 607 * reject packets with broadcast 608 */ 609 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 610 ia4; 611 ia4 = TAILQ_NEXT(ia4, ia_link)) 612 { 613 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 614 continue; 615 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 616 return -1; 617 } 618 619 /* 620 * perform ingress filter 621 */ 622 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 623 struct sockaddr_in sin; 624 struct rtentry *rt; 625 626 bzero(&sin, sizeof(sin)); 627 sin.sin_family = AF_INET; 628 sin.sin_len = sizeof(struct sockaddr_in); 629 sin.sin_addr = *in; 630 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 631 0UL, sc->sc_fibnum); 632 if (!rt || rt->rt_ifp != inifp) { 633 #if 0 634 log(LOG_WARNING, "%s: packet from 0x%x dropped " 635 "due to ingress filter\n", if_name(STF2IFP(sc)), 636 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 637 #endif 638 if (rt) 639 RTFREE_LOCKED(rt); 640 return -1; 641 } 642 RTFREE_LOCKED(rt); 643 } 644 645 return 0; 646 } 647 648 static int 649 stf_checkaddr6(sc, in6, inifp) 650 struct stf_softc *sc; 651 struct in6_addr *in6; 652 struct ifnet *inifp; /* incoming interface */ 653 { 654 /* 655 * check 6to4 addresses 656 */ 657 if (IN6_IS_ADDR_6TO4(in6)) { 658 struct in_addr in4; 659 bcopy(GET_V4(in6), &in4, sizeof(in4)); 660 return stf_checkaddr4(sc, &in4, inifp); 661 } 662 663 /* 664 * reject anything that look suspicious. the test is implemented 665 * in ip6_input too, but we check here as well to 666 * (1) reject bad packets earlier, and 667 * (2) to be safe against future ip6_input change. 668 */ 669 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 670 return -1; 671 672 return 0; 673 } 674 675 void 676 in_stf_input(m, off) 677 struct mbuf *m; 678 int off; 679 { 680 int proto; 681 struct stf_softc *sc; 682 struct ip *ip; 683 struct ip6_hdr *ip6; 684 u_int8_t otos, itos; 685 struct ifnet *ifp; 686 687 proto = mtod(m, struct ip *)->ip_p; 688 689 if (proto != IPPROTO_IPV6) { 690 m_freem(m); 691 return; 692 } 693 694 ip = mtod(m, struct ip *); 695 696 sc = (struct stf_softc *)encap_getarg(m); 697 698 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 699 m_freem(m); 700 return; 701 } 702 703 ifp = STF2IFP(sc); 704 705 #ifdef MAC 706 mac_create_mbuf_from_ifnet(ifp, m); 707 #endif 708 709 /* 710 * perform sanity check against outer src/dst. 711 * for source, perform ingress filter as well. 712 */ 713 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 714 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 715 m_freem(m); 716 return; 717 } 718 719 otos = ip->ip_tos; 720 m_adj(m, off); 721 722 if (m->m_len < sizeof(*ip6)) { 723 m = m_pullup(m, sizeof(*ip6)); 724 if (!m) 725 return; 726 } 727 ip6 = mtod(m, struct ip6_hdr *); 728 729 /* 730 * perform sanity check against inner src/dst. 731 * for source, perform ingress filter as well. 732 */ 733 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 734 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 735 m_freem(m); 736 return; 737 } 738 739 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 740 if ((ifp->if_flags & IFF_LINK1) != 0) 741 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 742 else 743 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 744 ip6->ip6_flow &= ~htonl(0xff << 20); 745 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 746 747 m->m_pkthdr.rcvif = ifp; 748 749 if (bpf_peers_present(ifp->if_bpf)) { 750 /* 751 * We need to prepend the address family as 752 * a four byte field. Cons up a dummy header 753 * to pacify bpf. This is safe because bpf 754 * will only read from the mbuf (i.e., it won't 755 * try to free it or keep a pointer a to it). 756 */ 757 u_int32_t af = AF_INET6; 758 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 759 } 760 761 /* 762 * Put the packet to the network layer input queue according to the 763 * specified address family. 764 * See net/if_gif.c for possible issues with packet processing 765 * reorder due to extra queueing. 766 */ 767 ifp->if_ipackets++; 768 ifp->if_ibytes += m->m_pkthdr.len; 769 netisr_dispatch(NETISR_IPV6, m); 770 } 771 772 /* ARGSUSED */ 773 static void 774 stf_rtrequest(cmd, rt, info) 775 int cmd; 776 struct rtentry *rt; 777 struct rt_addrinfo *info; 778 { 779 RT_LOCK_ASSERT(rt); 780 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 781 } 782 783 static int 784 stf_ioctl(ifp, cmd, data) 785 struct ifnet *ifp; 786 u_long cmd; 787 caddr_t data; 788 { 789 struct ifaddr *ifa; 790 struct ifreq *ifr; 791 struct sockaddr_in6 *sin6; 792 struct in_addr addr; 793 int error; 794 795 error = 0; 796 switch (cmd) { 797 case SIOCSIFADDR: 798 ifa = (struct ifaddr *)data; 799 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 800 error = EAFNOSUPPORT; 801 break; 802 } 803 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 804 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 805 error = EINVAL; 806 break; 807 } 808 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 809 if (isrfc1918addr(&addr)) { 810 error = EINVAL; 811 break; 812 } 813 814 ifa->ifa_rtrequest = stf_rtrequest; 815 ifp->if_flags |= IFF_UP; 816 break; 817 818 case SIOCADDMULTI: 819 case SIOCDELMULTI: 820 ifr = (struct ifreq *)data; 821 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 822 ; 823 else 824 error = EAFNOSUPPORT; 825 break; 826 827 default: 828 error = EINVAL; 829 break; 830 } 831 832 return error; 833 }
Cache object: 3eeb785b9fe44019fd1ecaa5474bb678
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