if_stf.c revision 191339
1/* $FreeBSD: head/sys/net/if_stf.c 191339 2009-04-20 22:41:19Z rwatson $ */ 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#include <sys/vimage.h> 97 98#include <net/if.h> 99#include <net/if_clone.h> 100#include <net/route.h> 101#include <net/netisr.h> 102#include <net/if_types.h> 103#include <net/if_stf.h> 104 105#include <netinet/in.h> 106#include <netinet/in_systm.h> 107#include <netinet/ip.h> 108#include <netinet/ip_var.h> 109#include <netinet/in_var.h> 110#include <netinet/vinet.h> 111 112#include <netinet/ip6.h> 113#include <netinet6/ip6_var.h> 114#include <netinet6/in6_var.h> 115#include <netinet/ip_ecn.h> 116 117#include <netinet/ip_encap.h> 118 119#include <machine/stdarg.h> 120 121#include <net/bpf.h> 122 123#include <security/mac/mac_framework.h> 124 125SYSCTL_DECL(_net_link); 126SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface"); 127 128static int stf_route_cache = 1; 129SYSCTL_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW, 130 &stf_route_cache, 0, "Caching of IPv4 routes for 6to4 Output"); 131 132#define STFNAME "stf" 133#define STFUNIT 0 134 135#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 136 137/* 138 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 139 * struct in_addr *; use bcopy() instead. 140 */ 141#define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 142 143struct stf_softc { 144 struct ifnet *sc_ifp; 145 union { 146 struct route __sc_ro4; 147 struct route_in6 __sc_ro6; /* just for safety */ 148 } __sc_ro46; 149#define sc_ro __sc_ro46.__sc_ro4 150 struct mtx sc_ro_mtx; 151 u_int sc_fibnum; 152 const struct encaptab *encap_cookie; 153}; 154#define STF2IFP(sc) ((sc)->sc_ifp) 155 156/* 157 * Note that mutable fields in the softc are not currently locked. 158 * We do lock sc_ro in stf_output though. 159 */ 160static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 161static const int ip_stf_ttl = 40; 162 163extern struct domain inetdomain; 164struct protosw in_stf_protosw = { 165 .pr_type = SOCK_RAW, 166 .pr_domain = &inetdomain, 167 .pr_protocol = IPPROTO_IPV6, 168 .pr_flags = PR_ATOMIC|PR_ADDR, 169 .pr_input = in_stf_input, 170 .pr_output = (pr_output_t *)rip_output, 171 .pr_ctloutput = rip_ctloutput, 172 .pr_usrreqs = &rip_usrreqs 173}; 174 175static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 176 177static int stfmodevent(module_t, int, void *); 178static int stf_encapcheck(const struct mbuf *, int, int, void *); 179static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 180static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 181 struct route *); 182static int isrfc1918addr(struct in_addr *); 183static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 184 struct ifnet *); 185static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 186 struct ifnet *); 187static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 188static int stf_ioctl(struct ifnet *, u_long, caddr_t); 189 190static int stf_clone_match(struct if_clone *, const char *); 191static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 192static int stf_clone_destroy(struct if_clone *, struct ifnet *); 193struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 194 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 195 196static int 197stf_clone_match(struct if_clone *ifc, const char *name) 198{ 199 int i; 200 201 for(i = 0; stfnames[i] != NULL; i++) { 202 if (strcmp(stfnames[i], name) == 0) 203 return (1); 204 } 205 206 return (0); 207} 208 209static int 210stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 211{ 212 int err, unit; 213 struct stf_softc *sc; 214 struct ifnet *ifp; 215 216 /* 217 * We can only have one unit, but since unit allocation is 218 * already locked, we use it to keep from allocating extra 219 * interfaces. 220 */ 221 unit = STFUNIT; 222 err = ifc_alloc_unit(ifc, &unit); 223 if (err != 0) 224 return (err); 225 226 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 227 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 228 if (ifp == NULL) { 229 free(sc, M_STF); 230 ifc_free_unit(ifc, unit); 231 return (ENOSPC); 232 } 233 ifp->if_softc = sc; 234 sc->sc_fibnum = curthread->td_proc->p_fibnum; 235 236 /* 237 * Set the name manually rather then using if_initname because 238 * we don't conform to the default naming convention for interfaces. 239 */ 240 strlcpy(ifp->if_xname, name, IFNAMSIZ); 241 ifp->if_dname = ifc->ifc_name; 242 ifp->if_dunit = IF_DUNIT_NONE; 243 244 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF); 245 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 246 stf_encapcheck, &in_stf_protosw, sc); 247 if (sc->encap_cookie == NULL) { 248 if_printf(ifp, "attach failed\n"); 249 free(sc, M_STF); 250 ifc_free_unit(ifc, unit); 251 return (ENOMEM); 252 } 253 254 ifp->if_mtu = IPV6_MMTU; 255 ifp->if_ioctl = stf_ioctl; 256 ifp->if_output = stf_output; 257 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN; 258 if_attach(ifp); 259 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 260 return (0); 261} 262 263static int 264stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 265{ 266 struct stf_softc *sc = ifp->if_softc; 267 int err; 268 269 err = encap_detach(sc->encap_cookie); 270 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 271 mtx_destroy(&(sc)->sc_ro_mtx); 272 bpfdetach(ifp); 273 if_detach(ifp); 274 if_free(ifp); 275 276 free(sc, M_STF); 277 ifc_free_unit(ifc, STFUNIT); 278 279 return (0); 280} 281 282static int 283stfmodevent(mod, type, data) 284 module_t mod; 285 int type; 286 void *data; 287{ 288 289 switch (type) { 290 case MOD_LOAD: 291 if_clone_attach(&stf_cloner); 292 break; 293 case MOD_UNLOAD: 294 if_clone_detach(&stf_cloner); 295 break; 296 default: 297 return (EOPNOTSUPP); 298 } 299 300 return (0); 301} 302 303static moduledata_t stf_mod = { 304 "if_stf", 305 stfmodevent, 306 0 307}; 308 309DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 310 311static int 312stf_encapcheck(m, off, proto, arg) 313 const struct mbuf *m; 314 int off; 315 int proto; 316 void *arg; 317{ 318 struct ip ip; 319 struct in6_ifaddr *ia6; 320 struct stf_softc *sc; 321 struct in_addr a, b, mask; 322 323 sc = (struct stf_softc *)arg; 324 if (sc == NULL) 325 return 0; 326 327 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 328 return 0; 329 330 /* IFF_LINK0 means "no decapsulation" */ 331 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 332 return 0; 333 334 if (proto != IPPROTO_IPV6) 335 return 0; 336 337 /* LINTED const cast */ 338 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 339 340 if (ip.ip_v != 4) 341 return 0; 342 343 ia6 = stf_getsrcifa6(STF2IFP(sc)); 344 if (ia6 == NULL) 345 return 0; 346 347 /* 348 * check if IPv4 dst matches the IPv4 address derived from the 349 * local 6to4 address. 350 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 351 */ 352 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 353 sizeof(ip.ip_dst)) != 0) 354 return 0; 355 356 /* 357 * check if IPv4 src matches the IPv4 address derived from the 358 * local 6to4 address masked by prefixmask. 359 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 360 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 361 */ 362 bzero(&a, sizeof(a)); 363 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 364 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 365 a.s_addr &= mask.s_addr; 366 b = ip.ip_src; 367 b.s_addr &= mask.s_addr; 368 if (a.s_addr != b.s_addr) 369 return 0; 370 371 /* stf interface makes single side match only */ 372 return 32; 373} 374 375static struct in6_ifaddr * 376stf_getsrcifa6(ifp) 377 struct ifnet *ifp; 378{ 379 INIT_VNET_INET(ifp->if_vnet); 380 struct ifaddr *ia; 381 struct in_ifaddr *ia4; 382 struct sockaddr_in6 *sin6; 383 struct in_addr in; 384 385 IF_ADDR_LOCK(ifp); 386 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 387 if (ia->ifa_addr->sa_family != AF_INET6) 388 continue; 389 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 390 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 391 continue; 392 393 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 394 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 395 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 396 break; 397 if (ia4 == NULL) 398 continue; 399 400 IF_ADDR_UNLOCK(ifp); 401 return (struct in6_ifaddr *)ia; 402 } 403 IF_ADDR_UNLOCK(ifp); 404 405 return NULL; 406} 407 408static int 409stf_output(ifp, m, dst, ro) 410 struct ifnet *ifp; 411 struct mbuf *m; 412 struct sockaddr *dst; 413 struct route *ro; 414{ 415 struct stf_softc *sc; 416 struct sockaddr_in6 *dst6; 417 struct route *cached_route; 418 struct in_addr in4; 419 caddr_t ptr; 420 struct sockaddr_in *dst4; 421 u_int8_t tos; 422 struct ip *ip; 423 struct ip6_hdr *ip6; 424 struct in6_ifaddr *ia6; 425 u_int32_t af; 426 int error; 427 428#ifdef MAC 429 error = mac_ifnet_check_transmit(ifp, m); 430 if (error) { 431 m_freem(m); 432 return (error); 433 } 434#endif 435 436 sc = ifp->if_softc; 437 dst6 = (struct sockaddr_in6 *)dst; 438 439 /* just in case */ 440 if ((ifp->if_flags & IFF_UP) == 0) { 441 m_freem(m); 442 ifp->if_oerrors++; 443 return ENETDOWN; 444 } 445 446 /* 447 * If we don't have an ip4 address that match my inner ip6 address, 448 * we shouldn't generate output. Without this check, we'll end up 449 * using wrong IPv4 source. 450 */ 451 ia6 = stf_getsrcifa6(ifp); 452 if (ia6 == NULL) { 453 m_freem(m); 454 ifp->if_oerrors++; 455 return ENETDOWN; 456 } 457 458 if (m->m_len < sizeof(*ip6)) { 459 m = m_pullup(m, sizeof(*ip6)); 460 if (!m) { 461 ifp->if_oerrors++; 462 return ENOBUFS; 463 } 464 } 465 ip6 = mtod(m, struct ip6_hdr *); 466 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 467 468 /* 469 * BPF writes need to be handled specially. 470 * This is a null operation, nothing here checks dst->sa_family. 471 */ 472 if (dst->sa_family == AF_UNSPEC) { 473 bcopy(dst->sa_data, &af, sizeof(af)); 474 dst->sa_family = af; 475 } 476 477 /* 478 * Pickup the right outer dst addr from the list of candidates. 479 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 480 */ 481 ptr = NULL; 482 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 483 ptr = GET_V4(&ip6->ip6_dst); 484 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 485 ptr = GET_V4(&dst6->sin6_addr); 486 else { 487 m_freem(m); 488 ifp->if_oerrors++; 489 return ENETUNREACH; 490 } 491 bcopy(ptr, &in4, sizeof(in4)); 492 493 if (bpf_peers_present(ifp->if_bpf)) { 494 /* 495 * We need to prepend the address family as 496 * a four byte field. Cons up a dummy header 497 * to pacify bpf. This is safe because bpf 498 * will only read from the mbuf (i.e., it won't 499 * try to free it or keep a pointer a to it). 500 */ 501 af = AF_INET6; 502 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 503 } 504 505 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 506 if (m && m->m_len < sizeof(struct ip)) 507 m = m_pullup(m, sizeof(struct ip)); 508 if (m == NULL) { 509 ifp->if_oerrors++; 510 return ENOBUFS; 511 } 512 ip = mtod(m, struct ip *); 513 514 bzero(ip, sizeof(*ip)); 515 516 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 517 &ip->ip_src, sizeof(ip->ip_src)); 518 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 519 ip->ip_p = IPPROTO_IPV6; 520 ip->ip_ttl = ip_stf_ttl; 521 ip->ip_len = m->m_pkthdr.len; /*host order*/ 522 if (ifp->if_flags & IFF_LINK1) 523 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 524 else 525 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 526 527 if (!stf_route_cache) { 528 cached_route = NULL; 529 goto sendit; 530 } 531 532 /* 533 * Do we have a cached route? 534 */ 535 mtx_lock(&(sc)->sc_ro_mtx); 536 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 537 if (dst4->sin_family != AF_INET || 538 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 539 /* cache route doesn't match */ 540 dst4->sin_family = AF_INET; 541 dst4->sin_len = sizeof(struct sockaddr_in); 542 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 543 if (sc->sc_ro.ro_rt) { 544 RTFREE(sc->sc_ro.ro_rt); 545 sc->sc_ro.ro_rt = NULL; 546 } 547 } 548 549 if (sc->sc_ro.ro_rt == NULL) { 550 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 551 if (sc->sc_ro.ro_rt == NULL) { 552 m_freem(m); 553 mtx_unlock(&(sc)->sc_ro_mtx); 554 ifp->if_oerrors++; 555 return ENETUNREACH; 556 } 557 } 558 cached_route = &sc->sc_ro; 559 560sendit: 561 M_SETFIB(m, sc->sc_fibnum); 562 ifp->if_opackets++; 563 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 564 565 if (cached_route != NULL) 566 mtx_unlock(&(sc)->sc_ro_mtx); 567 return error; 568} 569 570static int 571isrfc1918addr(in) 572 struct in_addr *in; 573{ 574 /* 575 * returns 1 if private address range: 576 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 577 */ 578 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 579 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 580 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 581 return 1; 582 583 return 0; 584} 585 586static int 587stf_checkaddr4(sc, in, inifp) 588 struct stf_softc *sc; 589 struct in_addr *in; 590 struct ifnet *inifp; /* incoming interface */ 591{ 592 INIT_VNET_INET(curvnet); 593 struct in_ifaddr *ia4; 594 595 /* 596 * reject packets with the following address: 597 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 598 */ 599 if (IN_MULTICAST(ntohl(in->s_addr))) 600 return -1; 601 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 602 case 0: case 127: case 255: 603 return -1; 604 } 605 606 /* 607 * reject packets with private address range. 608 * (requirement from RFC3056 section 2 1st paragraph) 609 */ 610 if (isrfc1918addr(in)) 611 return -1; 612 613 /* 614 * reject packets with broadcast 615 */ 616 for (ia4 = TAILQ_FIRST(&V_in_ifaddrhead); 617 ia4; 618 ia4 = TAILQ_NEXT(ia4, ia_link)) 619 { 620 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 621 continue; 622 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 623 return -1; 624 } 625 626 /* 627 * perform ingress filter 628 */ 629 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 630 struct sockaddr_in sin; 631 struct rtentry *rt; 632 633 bzero(&sin, sizeof(sin)); 634 sin.sin_family = AF_INET; 635 sin.sin_len = sizeof(struct sockaddr_in); 636 sin.sin_addr = *in; 637 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 638 0UL, sc->sc_fibnum); 639 if (!rt || rt->rt_ifp != inifp) { 640#if 0 641 log(LOG_WARNING, "%s: packet from 0x%x dropped " 642 "due to ingress filter\n", if_name(STF2IFP(sc)), 643 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 644#endif 645 if (rt) 646 RTFREE_LOCKED(rt); 647 return -1; 648 } 649 RTFREE_LOCKED(rt); 650 } 651 652 return 0; 653} 654 655static int 656stf_checkaddr6(sc, in6, inifp) 657 struct stf_softc *sc; 658 struct in6_addr *in6; 659 struct ifnet *inifp; /* incoming interface */ 660{ 661 /* 662 * check 6to4 addresses 663 */ 664 if (IN6_IS_ADDR_6TO4(in6)) { 665 struct in_addr in4; 666 bcopy(GET_V4(in6), &in4, sizeof(in4)); 667 return stf_checkaddr4(sc, &in4, inifp); 668 } 669 670 /* 671 * reject anything that look suspicious. the test is implemented 672 * in ip6_input too, but we check here as well to 673 * (1) reject bad packets earlier, and 674 * (2) to be safe against future ip6_input change. 675 */ 676 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 677 return -1; 678 679 return 0; 680} 681 682void 683in_stf_input(m, off) 684 struct mbuf *m; 685 int off; 686{ 687 int proto; 688 struct stf_softc *sc; 689 struct ip *ip; 690 struct ip6_hdr *ip6; 691 u_int8_t otos, itos; 692 struct ifnet *ifp; 693 694 proto = mtod(m, struct ip *)->ip_p; 695 696 if (proto != IPPROTO_IPV6) { 697 m_freem(m); 698 return; 699 } 700 701 ip = mtod(m, struct ip *); 702 703 sc = (struct stf_softc *)encap_getarg(m); 704 705 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 706 m_freem(m); 707 return; 708 } 709 710 ifp = STF2IFP(sc); 711 712#ifdef MAC 713 mac_ifnet_create_mbuf(ifp, m); 714#endif 715 716 /* 717 * perform sanity check against outer src/dst. 718 * for source, perform ingress filter as well. 719 */ 720 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 721 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 722 m_freem(m); 723 return; 724 } 725 726 otos = ip->ip_tos; 727 m_adj(m, off); 728 729 if (m->m_len < sizeof(*ip6)) { 730 m = m_pullup(m, sizeof(*ip6)); 731 if (!m) 732 return; 733 } 734 ip6 = mtod(m, struct ip6_hdr *); 735 736 /* 737 * perform sanity check against inner src/dst. 738 * for source, perform ingress filter as well. 739 */ 740 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 741 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 742 m_freem(m); 743 return; 744 } 745 746 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 747 if ((ifp->if_flags & IFF_LINK1) != 0) 748 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 749 else 750 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 751 ip6->ip6_flow &= ~htonl(0xff << 20); 752 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 753 754 m->m_pkthdr.rcvif = ifp; 755 756 if (bpf_peers_present(ifp->if_bpf)) { 757 /* 758 * We need to prepend the address family as 759 * a four byte field. Cons up a dummy header 760 * to pacify bpf. This is safe because bpf 761 * will only read from the mbuf (i.e., it won't 762 * try to free it or keep a pointer a to it). 763 */ 764 u_int32_t af = AF_INET6; 765 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 766 } 767 768 /* 769 * Put the packet to the network layer input queue according to the 770 * specified address family. 771 * See net/if_gif.c for possible issues with packet processing 772 * reorder due to extra queueing. 773 */ 774 ifp->if_ipackets++; 775 ifp->if_ibytes += m->m_pkthdr.len; 776 netisr_dispatch(NETISR_IPV6, m); 777} 778 779/* ARGSUSED */ 780static void 781stf_rtrequest(cmd, rt, info) 782 int cmd; 783 struct rtentry *rt; 784 struct rt_addrinfo *info; 785{ 786 RT_LOCK_ASSERT(rt); 787 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 788} 789 790static int 791stf_ioctl(ifp, cmd, data) 792 struct ifnet *ifp; 793 u_long cmd; 794 caddr_t data; 795{ 796 struct ifaddr *ifa; 797 struct ifreq *ifr; 798 struct sockaddr_in6 *sin6; 799 struct in_addr addr; 800 int error; 801 802 error = 0; 803 switch (cmd) { 804 case SIOCSIFADDR: 805 ifa = (struct ifaddr *)data; 806 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 807 error = EAFNOSUPPORT; 808 break; 809 } 810 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 811 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 812 error = EINVAL; 813 break; 814 } 815 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 816 if (isrfc1918addr(&addr)) { 817 error = EINVAL; 818 break; 819 } 820 821 ifa->ifa_rtrequest = stf_rtrequest; 822 ifp->if_flags |= IFF_UP; 823 break; 824 825 case SIOCADDMULTI: 826 case SIOCDELMULTI: 827 ifr = (struct ifreq *)data; 828 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 829 ; 830 else 831 error = EAFNOSUPPORT; 832 break; 833 834 default: 835 error = EINVAL; 836 break; 837 } 838 839 return error; 840} 841