if_stf.c revision 151266
1/* $FreeBSD: head/sys/net/if_stf.c 151266 2005-10-12 19:52:16Z thompsa $ */ 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/mac.h> 86#include <sys/mbuf.h> 87#include <sys/errno.h> 88#include <sys/kernel.h> 89#include <sys/module.h> 90#include <sys/protosw.h> 91#include <sys/queue.h> 92#include <machine/cpu.h> 93 94#include <sys/malloc.h> 95 96#include <net/if.h> 97#include <net/if_clone.h> 98#include <net/route.h> 99#include <net/netisr.h> 100#include <net/if_types.h> 101#include <net/if_stf.h> 102 103#include <netinet/in.h> 104#include <netinet/in_systm.h> 105#include <netinet/ip.h> 106#include <netinet/ip_var.h> 107#include <netinet/in_var.h> 108 109#include <netinet/ip6.h> 110#include <netinet6/ip6_var.h> 111#include <netinet6/in6_var.h> 112#include <netinet/ip_ecn.h> 113 114#include <netinet/ip_encap.h> 115 116#include <machine/stdarg.h> 117 118#include <net/net_osdep.h> 119 120#include <net/bpf.h> 121 122#define STFNAME "stf" 123#define STFUNIT 0 124 125#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 126 127/* 128 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 129 * struct in_addr *; use bcopy() instead. 130 */ 131#define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 132 133struct stf_softc { 134 struct ifnet *sc_ifp; 135 union { 136 struct route __sc_ro4; 137 struct route_in6 __sc_ro6; /* just for safety */ 138 } __sc_ro46; 139#define sc_ro __sc_ro46.__sc_ro4 140 const struct encaptab *encap_cookie; 141 LIST_ENTRY(stf_softc) sc_list; /* all stf's are linked */ 142}; 143#define STF2IFP(sc) ((sc)->sc_ifp) 144 145/* 146 * All mutable global variables in if_stf.c are protected by stf_mtx. 147 * XXXRW: Note that mutable fields in the softc are not currently locked: 148 * in particular, sc_ro needs to be protected from concurrent entrance 149 * of stf_output(). 150 */ 151static struct mtx stf_mtx; 152static LIST_HEAD(, stf_softc) stf_softc_list; 153 154static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 155static const int ip_stf_ttl = 40; 156 157extern struct domain inetdomain; 158struct protosw in_stf_protosw = 159{ SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 160 in_stf_input, (pr_output_t*)rip_output, 0, rip_ctloutput, 161 0, 162 0, 0, 0, 0, 163 &rip_usrreqs 164}; 165 166static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 167 168static int stfmodevent(module_t, int, void *); 169static int stf_encapcheck(const struct mbuf *, int, int, void *); 170static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 171static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 172 struct rtentry *); 173static int isrfc1918addr(struct in_addr *); 174static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 175 struct ifnet *); 176static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 177 struct ifnet *); 178static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 179static int stf_ioctl(struct ifnet *, u_long, caddr_t); 180 181static int stf_clone_match(struct if_clone *, const char *); 182static int stf_clone_create(struct if_clone *, char *, size_t); 183static int stf_clone_destroy(struct if_clone *, struct ifnet *); 184struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 185 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 186 187static int 188stf_clone_match(struct if_clone *ifc, const char *name) 189{ 190 int i; 191 192 for(i = 0; stfnames[i] != NULL; i++) { 193 if (strcmp(stfnames[i], name) == 0) 194 return (1); 195 } 196 197 return (0); 198} 199 200static int 201stf_clone_create(struct if_clone *ifc, char *name, size_t len) 202{ 203 int err, unit; 204 struct stf_softc *sc; 205 struct ifnet *ifp; 206 207 /* 208 * We can only have one unit, but since unit allocation is 209 * already locked, we use it to keep from allocating extra 210 * interfaces. 211 */ 212 unit = STFUNIT; 213 err = ifc_alloc_unit(ifc, &unit); 214 if (err != 0) 215 return (err); 216 217 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 218 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 219 if (ifp == NULL) { 220 free(sc, M_STF); 221 ifc_free_unit(ifc, unit); 222 return (ENOSPC); 223 } 224 ifp->if_softc = sc; 225 226 /* 227 * Set the name manually rather then using if_initname because 228 * we don't conform to the default naming convention for interfaces. 229 */ 230 strlcpy(ifp->if_xname, name, IFNAMSIZ); 231 ifp->if_dname = ifc->ifc_name; 232 ifp->if_dunit = IF_DUNIT_NONE; 233 234 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 235 stf_encapcheck, &in_stf_protosw, sc); 236 if (sc->encap_cookie == NULL) { 237 if_printf(ifp, "attach failed\n"); 238 free(sc, M_STF); 239 ifc_free_unit(ifc, unit); 240 return (ENOMEM); 241 } 242 243 ifp->if_mtu = IPV6_MMTU; 244 ifp->if_ioctl = stf_ioctl; 245 ifp->if_output = stf_output; 246 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN; 247 if_attach(ifp); 248 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 249 mtx_lock(&stf_mtx); 250 LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list); 251 mtx_unlock(&stf_mtx); 252 return (0); 253} 254 255static int 256stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 257{ 258 struct stf_softc *sc = ifp->if_softc; 259 int err; 260 261 mtx_lock(&stf_mtx); 262 LIST_REMOVE(sc, sc_list); 263 mtx_unlock(&stf_mtx); 264 265 err = encap_detach(sc->encap_cookie); 266 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 267 bpfdetach(ifp); 268 if_detach(ifp); 269 if_free(ifp); 270 271 free(sc, M_STF); 272 ifc_free_unit(ifc, STFUNIT); 273 274 return (0); 275} 276 277static int 278stfmodevent(mod, type, data) 279 module_t mod; 280 int type; 281 void *data; 282{ 283 struct stf_softc *sc; 284 285 switch (type) { 286 case MOD_LOAD: 287 mtx_init(&stf_mtx, "stf_mtx", NULL, MTX_DEF); 288 LIST_INIT(&stf_softc_list); 289 if_clone_attach(&stf_cloner); 290 291 break; 292 case MOD_UNLOAD: 293 if_clone_detach(&stf_cloner); 294 295 mtx_lock(&stf_mtx); 296 while ((sc = LIST_FIRST(&stf_softc_list)) != NULL) { 297 mtx_unlock(&stf_mtx); 298 stf_clone_destroy(&stf_cloner, STF2IFP(sc)); 299 mtx_lock(&stf_mtx); 300 } 301 mtx_unlock(&stf_mtx); 302 mtx_destroy(&stf_mtx); 303 break; 304 default: 305 return (EOPNOTSUPP); 306 } 307 308 return (0); 309} 310 311static moduledata_t stf_mod = { 312 "if_stf", 313 stfmodevent, 314 0 315}; 316 317DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 318 319static int 320stf_encapcheck(m, off, proto, arg) 321 const struct mbuf *m; 322 int off; 323 int proto; 324 void *arg; 325{ 326 struct ip ip; 327 struct in6_ifaddr *ia6; 328 struct stf_softc *sc; 329 struct in_addr a, b, mask; 330 331 sc = (struct stf_softc *)arg; 332 if (sc == NULL) 333 return 0; 334 335 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 336 return 0; 337 338 /* IFF_LINK0 means "no decapsulation" */ 339 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 340 return 0; 341 342 if (proto != IPPROTO_IPV6) 343 return 0; 344 345 /* LINTED const cast */ 346 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 347 348 if (ip.ip_v != 4) 349 return 0; 350 351 ia6 = stf_getsrcifa6(STF2IFP(sc)); 352 if (ia6 == NULL) 353 return 0; 354 355 /* 356 * check if IPv4 dst matches the IPv4 address derived from the 357 * local 6to4 address. 358 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 359 */ 360 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 361 sizeof(ip.ip_dst)) != 0) 362 return 0; 363 364 /* 365 * check if IPv4 src matches the IPv4 address derived from the 366 * local 6to4 address masked by prefixmask. 367 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 368 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 369 */ 370 bzero(&a, sizeof(a)); 371 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 372 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 373 a.s_addr &= mask.s_addr; 374 b = ip.ip_src; 375 b.s_addr &= mask.s_addr; 376 if (a.s_addr != b.s_addr) 377 return 0; 378 379 /* stf interface makes single side match only */ 380 return 32; 381} 382 383static struct in6_ifaddr * 384stf_getsrcifa6(ifp) 385 struct ifnet *ifp; 386{ 387 struct ifaddr *ia; 388 struct in_ifaddr *ia4; 389 struct sockaddr_in6 *sin6; 390 struct in_addr in; 391 392 for (ia = TAILQ_FIRST(&ifp->if_addrlist); 393 ia; 394 ia = TAILQ_NEXT(ia, ifa_list)) 395 { 396 if (ia->ifa_addr == NULL) 397 continue; 398 if (ia->ifa_addr->sa_family != AF_INET6) 399 continue; 400 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 401 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 402 continue; 403 404 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 405 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 406 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 407 break; 408 if (ia4 == NULL) 409 continue; 410 411 return (struct in6_ifaddr *)ia; 412 } 413 414 return NULL; 415} 416 417static int 418stf_output(ifp, m, dst, rt) 419 struct ifnet *ifp; 420 struct mbuf *m; 421 struct sockaddr *dst; 422 struct rtentry *rt; 423{ 424 struct stf_softc *sc; 425 struct sockaddr_in6 *dst6; 426 struct in_addr in4; 427 caddr_t ptr; 428 struct sockaddr_in *dst4; 429 u_int8_t tos; 430 struct ip *ip; 431 struct ip6_hdr *ip6; 432 struct in6_ifaddr *ia6; 433 u_int32_t af; 434#ifdef MAC 435 int error; 436 437 error = mac_check_ifnet_transmit(ifp, m); 438 if (error) { 439 m_freem(m); 440 return (error); 441 } 442#endif 443 444 sc = ifp->if_softc; 445 dst6 = (struct sockaddr_in6 *)dst; 446 447 /* just in case */ 448 if ((ifp->if_flags & IFF_UP) == 0) { 449 m_freem(m); 450 ifp->if_oerrors++; 451 return ENETDOWN; 452 } 453 454 /* 455 * If we don't have an ip4 address that match my inner ip6 address, 456 * we shouldn't generate output. Without this check, we'll end up 457 * using wrong IPv4 source. 458 */ 459 ia6 = stf_getsrcifa6(ifp); 460 if (ia6 == NULL) { 461 m_freem(m); 462 ifp->if_oerrors++; 463 return ENETDOWN; 464 } 465 466 if (m->m_len < sizeof(*ip6)) { 467 m = m_pullup(m, sizeof(*ip6)); 468 if (!m) { 469 ifp->if_oerrors++; 470 return ENOBUFS; 471 } 472 } 473 ip6 = mtod(m, struct ip6_hdr *); 474 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 475 476 /* 477 * BPF writes need to be handled specially. 478 * This is a null operation, nothing here checks dst->sa_family. 479 */ 480 if (dst->sa_family == AF_UNSPEC) { 481 bcopy(dst->sa_data, &af, sizeof(af)); 482 dst->sa_family = af; 483 } 484 485 /* 486 * Pickup the right outer dst addr from the list of candidates. 487 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 488 */ 489 ptr = NULL; 490 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 491 ptr = GET_V4(&ip6->ip6_dst); 492 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 493 ptr = GET_V4(&dst6->sin6_addr); 494 else { 495 m_freem(m); 496 ifp->if_oerrors++; 497 return ENETUNREACH; 498 } 499 bcopy(ptr, &in4, sizeof(in4)); 500 501 if (ifp->if_bpf) { 502 /* 503 * We need to prepend the address family as 504 * a four byte field. Cons up a dummy header 505 * to pacify bpf. This is safe because bpf 506 * will only read from the mbuf (i.e., it won't 507 * try to free it or keep a pointer a to it). 508 */ 509 af = AF_INET6; 510 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 511 } 512 513 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 514 if (m && m->m_len < sizeof(struct ip)) 515 m = m_pullup(m, sizeof(struct ip)); 516 if (m == NULL) { 517 ifp->if_oerrors++; 518 return ENOBUFS; 519 } 520 ip = mtod(m, struct ip *); 521 522 bzero(ip, sizeof(*ip)); 523 524 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 525 &ip->ip_src, sizeof(ip->ip_src)); 526 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 527 ip->ip_p = IPPROTO_IPV6; 528 ip->ip_ttl = ip_stf_ttl; 529 ip->ip_len = m->m_pkthdr.len; /*host order*/ 530 if (ifp->if_flags & IFF_LINK1) 531 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 532 else 533 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 534 535 /* 536 * XXXRW: Locking of sc_ro required. 537 */ 538 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 539 if (dst4->sin_family != AF_INET || 540 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 541 /* cache route doesn't match */ 542 dst4->sin_family = AF_INET; 543 dst4->sin_len = sizeof(struct sockaddr_in); 544 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 545 if (sc->sc_ro.ro_rt) { 546 RTFREE(sc->sc_ro.ro_rt); 547 sc->sc_ro.ro_rt = NULL; 548 } 549 } 550 551 if (sc->sc_ro.ro_rt == NULL) { 552 rtalloc(&sc->sc_ro); 553 if (sc->sc_ro.ro_rt == NULL) { 554 m_freem(m); 555 ifp->if_oerrors++; 556 return ENETUNREACH; 557 } 558 } 559 560 ifp->if_opackets++; 561 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 562} 563 564static int 565isrfc1918addr(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 580static int 581stf_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((struct sockaddr *)&sin, 0, 0UL); 631 if (!rt || rt->rt_ifp != inifp) { 632#if 0 633 log(LOG_WARNING, "%s: packet from 0x%x dropped " 634 "due to ingress filter\n", if_name(STF2IFP(sc)), 635 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 636#endif 637 if (rt) 638 rtfree(rt); 639 return -1; 640 } 641 rtfree(rt); 642 } 643 644 return 0; 645} 646 647static int 648stf_checkaddr6(sc, in6, inifp) 649 struct stf_softc *sc; 650 struct in6_addr *in6; 651 struct ifnet *inifp; /* incoming interface */ 652{ 653 /* 654 * check 6to4 addresses 655 */ 656 if (IN6_IS_ADDR_6TO4(in6)) { 657 struct in_addr in4; 658 bcopy(GET_V4(in6), &in4, sizeof(in4)); 659 return stf_checkaddr4(sc, &in4, inifp); 660 } 661 662 /* 663 * reject anything that look suspicious. the test is implemented 664 * in ip6_input too, but we check here as well to 665 * (1) reject bad packets earlier, and 666 * (2) to be safe against future ip6_input change. 667 */ 668 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 669 return -1; 670 671 return 0; 672} 673 674void 675in_stf_input(m, off) 676 struct mbuf *m; 677 int off; 678{ 679 int proto; 680 struct stf_softc *sc; 681 struct ip *ip; 682 struct ip6_hdr *ip6; 683 u_int8_t otos, itos; 684 struct ifnet *ifp; 685 686 proto = mtod(m, struct ip *)->ip_p; 687 688 if (proto != IPPROTO_IPV6) { 689 m_freem(m); 690 return; 691 } 692 693 ip = mtod(m, struct ip *); 694 695 sc = (struct stf_softc *)encap_getarg(m); 696 697 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 698 m_freem(m); 699 return; 700 } 701 702 ifp = STF2IFP(sc); 703 704#ifdef MAC 705 mac_create_mbuf_from_ifnet(ifp, m); 706#endif 707 708 /* 709 * perform sanity check against outer src/dst. 710 * for source, perform ingress filter as well. 711 */ 712 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 713 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 714 m_freem(m); 715 return; 716 } 717 718 otos = ip->ip_tos; 719 m_adj(m, off); 720 721 if (m->m_len < sizeof(*ip6)) { 722 m = m_pullup(m, sizeof(*ip6)); 723 if (!m) 724 return; 725 } 726 ip6 = mtod(m, struct ip6_hdr *); 727 728 /* 729 * perform sanity check against inner src/dst. 730 * for source, perform ingress filter as well. 731 */ 732 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 733 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 734 m_freem(m); 735 return; 736 } 737 738 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 739 if ((ifp->if_flags & IFF_LINK1) != 0) 740 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 741 else 742 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 743 ip6->ip6_flow &= ~htonl(0xff << 20); 744 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 745 746 m->m_pkthdr.rcvif = ifp; 747 748 if (ifp->if_bpf) { 749 /* 750 * We need to prepend the address family as 751 * a four byte field. Cons up a dummy header 752 * to pacify bpf. This is safe because bpf 753 * will only read from the mbuf (i.e., it won't 754 * try to free it or keep a pointer a to it). 755 */ 756 u_int32_t af = AF_INET6; 757 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 758 } 759 760 /* 761 * Put the packet to the network layer input queue according to the 762 * specified address family. 763 * See net/if_gif.c for possible issues with packet processing 764 * reorder due to extra queueing. 765 */ 766 ifp->if_ipackets++; 767 ifp->if_ibytes += m->m_pkthdr.len; 768 netisr_dispatch(NETISR_IPV6, m); 769} 770 771/* ARGSUSED */ 772static void 773stf_rtrequest(cmd, rt, info) 774 int cmd; 775 struct rtentry *rt; 776 struct rt_addrinfo *info; 777{ 778 RT_LOCK_ASSERT(rt); 779 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 780} 781 782static int 783stf_ioctl(ifp, cmd, data) 784 struct ifnet *ifp; 785 u_long cmd; 786 caddr_t data; 787{ 788 struct ifaddr *ifa; 789 struct ifreq *ifr; 790 struct sockaddr_in6 *sin6; 791 struct in_addr addr; 792 int error; 793 794 error = 0; 795 switch (cmd) { 796 case SIOCSIFADDR: 797 ifa = (struct ifaddr *)data; 798 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 799 error = EAFNOSUPPORT; 800 break; 801 } 802 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 803 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 804 error = EINVAL; 805 break; 806 } 807 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 808 if (isrfc1918addr(&addr)) { 809 error = EINVAL; 810 break; 811 } 812 813 ifa->ifa_rtrequest = stf_rtrequest; 814 ifp->if_flags |= IFF_UP; 815 break; 816 817 case SIOCADDMULTI: 818 case SIOCDELMULTI: 819 ifr = (struct ifreq *)data; 820 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 821 ; 822 else 823 error = EAFNOSUPPORT; 824 break; 825 826 default: 827 error = EINVAL; 828 break; 829 } 830 831 return error; 832} 833