if_stf.c revision 249925
1/* $FreeBSD: head/sys/net/if_stf.c 249925 2013-04-26 12:50:32Z glebius $ */ 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 80#include <sys/param.h> 81#include <sys/systm.h> 82#include <sys/socket.h> 83#include <sys/sockio.h> 84#include <sys/mbuf.h> 85#include <sys/errno.h> 86#include <sys/kernel.h> 87#include <sys/module.h> 88#include <sys/protosw.h> 89#include <sys/proc.h> 90#include <sys/queue.h> 91#include <sys/sysctl.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#include <net/vnet.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 123SYSCTL_DECL(_net_link); 124static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface"); 125 126static int stf_route_cache = 1; 127SYSCTL_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW, 128 &stf_route_cache, 0, "Caching of IPv4 routes for 6to4 Output"); 129 130static int stf_permit_rfc1918 = 0; 131TUNABLE_INT("net.link.stf.permit_rfc1918", &stf_permit_rfc1918); 132SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RW | CTLFLAG_TUN, 133 &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses"); 134 135#define STFUNIT 0 136 137#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 138 139/* 140 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 141 * struct in_addr *; use bcopy() instead. 142 */ 143#define GET_V4(x) (&(x)->s6_addr16[1]) 144 145struct stf_softc { 146 struct ifnet *sc_ifp; 147 union { 148 struct route __sc_ro4; 149 struct route_in6 __sc_ro6; /* just for safety */ 150 } __sc_ro46; 151#define sc_ro __sc_ro46.__sc_ro4 152 struct mtx sc_ro_mtx; 153 u_int sc_fibnum; 154 const struct encaptab *encap_cookie; 155}; 156#define STF2IFP(sc) ((sc)->sc_ifp) 157 158static const char stfname[] = "stf"; 159 160/* 161 * Note that mutable fields in the softc are not currently locked. 162 * We do lock sc_ro in stf_output though. 163 */ 164static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface"); 165static const int ip_stf_ttl = 40; 166 167extern struct domain inetdomain; 168struct protosw in_stf_protosw = { 169 .pr_type = SOCK_RAW, 170 .pr_domain = &inetdomain, 171 .pr_protocol = IPPROTO_IPV6, 172 .pr_flags = PR_ATOMIC|PR_ADDR, 173 .pr_input = in_stf_input, 174 .pr_output = (pr_output_t *)rip_output, 175 .pr_ctloutput = rip_ctloutput, 176 .pr_usrreqs = &rip_usrreqs 177}; 178 179static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 180 181static int stfmodevent(module_t, int, void *); 182static int stf_encapcheck(const struct mbuf *, int, int, void *); 183static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 184static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *, 185 struct route *); 186static int isrfc1918addr(struct in_addr *); 187static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 188 struct ifnet *); 189static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 190 struct ifnet *); 191static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 192static int stf_ioctl(struct ifnet *, u_long, caddr_t); 193 194static int stf_clone_match(struct if_clone *, const char *); 195static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 196static int stf_clone_destroy(struct if_clone *, struct ifnet *); 197static struct if_clone *stf_cloner; 198 199static int 200stf_clone_match(struct if_clone *ifc, const char *name) 201{ 202 int i; 203 204 for(i = 0; stfnames[i] != NULL; i++) { 205 if (strcmp(stfnames[i], name) == 0) 206 return (1); 207 } 208 209 return (0); 210} 211 212static int 213stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 214{ 215 int err, unit; 216 struct stf_softc *sc; 217 struct ifnet *ifp; 218 219 /* 220 * We can only have one unit, but since unit allocation is 221 * already locked, we use it to keep from allocating extra 222 * interfaces. 223 */ 224 unit = STFUNIT; 225 err = ifc_alloc_unit(ifc, &unit); 226 if (err != 0) 227 return (err); 228 229 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 230 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 231 if (ifp == NULL) { 232 free(sc, M_STF); 233 ifc_free_unit(ifc, unit); 234 return (ENOSPC); 235 } 236 ifp->if_softc = sc; 237 sc->sc_fibnum = curthread->td_proc->p_fibnum; 238 239 /* 240 * Set the name manually rather then using if_initname because 241 * we don't conform to the default naming convention for interfaces. 242 */ 243 strlcpy(ifp->if_xname, name, IFNAMSIZ); 244 ifp->if_dname = stfname; 245 ifp->if_dunit = IF_DUNIT_NONE; 246 247 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF); 248 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 249 stf_encapcheck, &in_stf_protosw, sc); 250 if (sc->encap_cookie == NULL) { 251 if_printf(ifp, "attach failed\n"); 252 free(sc, M_STF); 253 ifc_free_unit(ifc, unit); 254 return (ENOMEM); 255 } 256 257 ifp->if_mtu = IPV6_MMTU; 258 ifp->if_ioctl = stf_ioctl; 259 ifp->if_output = stf_output; 260 ifp->if_snd.ifq_maxlen = ifqmaxlen; 261 if_attach(ifp); 262 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 263 return (0); 264} 265 266static int 267stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 268{ 269 struct stf_softc *sc = ifp->if_softc; 270 int err; 271 272 err = encap_detach(sc->encap_cookie); 273 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 274 mtx_destroy(&(sc)->sc_ro_mtx); 275 bpfdetach(ifp); 276 if_detach(ifp); 277 if_free(ifp); 278 279 free(sc, M_STF); 280 ifc_free_unit(ifc, STFUNIT); 281 282 return (0); 283} 284 285static int 286stfmodevent(mod, type, data) 287 module_t mod; 288 int type; 289 void *data; 290{ 291 292 switch (type) { 293 case MOD_LOAD: 294 stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match, 295 stf_clone_create, stf_clone_destroy); 296 break; 297 case MOD_UNLOAD: 298 if_clone_detach(stf_cloner); 299 break; 300 default: 301 return (EOPNOTSUPP); 302 } 303 304 return (0); 305} 306 307static moduledata_t stf_mod = { 308 "if_stf", 309 stfmodevent, 310 0 311}; 312 313DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 314 315static int 316stf_encapcheck(m, off, proto, arg) 317 const struct mbuf *m; 318 int off; 319 int proto; 320 void *arg; 321{ 322 struct ip ip; 323 struct in6_ifaddr *ia6; 324 struct stf_softc *sc; 325 struct in_addr a, b, mask; 326 327 sc = (struct stf_softc *)arg; 328 if (sc == NULL) 329 return 0; 330 331 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 332 return 0; 333 334 /* IFF_LINK0 means "no decapsulation" */ 335 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 336 return 0; 337 338 if (proto != IPPROTO_IPV6) 339 return 0; 340 341 /* LINTED const cast */ 342 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 343 344 if (ip.ip_v != 4) 345 return 0; 346 347 ia6 = stf_getsrcifa6(STF2IFP(sc)); 348 if (ia6 == NULL) 349 return 0; 350 351 /* 352 * check if IPv4 dst matches the IPv4 address derived from the 353 * local 6to4 address. 354 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 355 */ 356 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 357 sizeof(ip.ip_dst)) != 0) { 358 ifa_free(&ia6->ia_ifa); 359 return 0; 360 } 361 362 /* 363 * check if IPv4 src matches the IPv4 address derived from the 364 * local 6to4 address masked by prefixmask. 365 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 366 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 367 */ 368 bzero(&a, sizeof(a)); 369 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 370 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 371 ifa_free(&ia6->ia_ifa); 372 a.s_addr &= mask.s_addr; 373 b = ip.ip_src; 374 b.s_addr &= mask.s_addr; 375 if (a.s_addr != b.s_addr) 376 return 0; 377 378 /* stf interface makes single side match only */ 379 return 32; 380} 381 382static struct in6_ifaddr * 383stf_getsrcifa6(ifp) 384 struct ifnet *ifp; 385{ 386 struct ifaddr *ia; 387 struct in_ifaddr *ia4; 388 struct sockaddr_in6 *sin6; 389 struct in_addr in; 390 391 if_addr_rlock(ifp); 392 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 393 if (ia->ifa_addr->sa_family != AF_INET6) 394 continue; 395 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 396 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 397 continue; 398 399 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 400 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 401 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 402 break; 403 if (ia4 == NULL) 404 continue; 405 406 ifa_ref(ia); 407 if_addr_runlock(ifp); 408 return (struct in6_ifaddr *)ia; 409 } 410 if_addr_runlock(ifp); 411 412 return NULL; 413} 414 415static int 416stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 417 struct route *ro) 418{ 419 struct stf_softc *sc; 420 const struct sockaddr_in6 *dst6; 421 struct route *cached_route; 422 struct in_addr in4; 423 const void *ptr; 424 struct sockaddr_in *dst4; 425 u_int8_t tos; 426 struct ip *ip; 427 struct ip6_hdr *ip6; 428 struct in6_ifaddr *ia6; 429 int error; 430 431#ifdef MAC 432 error = mac_ifnet_check_transmit(ifp, m); 433 if (error) { 434 m_freem(m); 435 return (error); 436 } 437#endif 438 439 sc = ifp->if_softc; 440 dst6 = (const struct sockaddr_in6 *)dst; 441 442 /* just in case */ 443 if ((ifp->if_flags & IFF_UP) == 0) { 444 m_freem(m); 445 ifp->if_oerrors++; 446 return ENETDOWN; 447 } 448 449 /* 450 * If we don't have an ip4 address that match my inner ip6 address, 451 * we shouldn't generate output. Without this check, we'll end up 452 * using wrong IPv4 source. 453 */ 454 ia6 = stf_getsrcifa6(ifp); 455 if (ia6 == NULL) { 456 m_freem(m); 457 ifp->if_oerrors++; 458 return ENETDOWN; 459 } 460 461 if (m->m_len < sizeof(*ip6)) { 462 m = m_pullup(m, sizeof(*ip6)); 463 if (!m) { 464 ifa_free(&ia6->ia_ifa); 465 ifp->if_oerrors++; 466 return ENOBUFS; 467 } 468 } 469 ip6 = mtod(m, struct ip6_hdr *); 470 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 471 472 /* 473 * Pickup the right outer dst addr from the list of candidates. 474 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 475 */ 476 ptr = NULL; 477 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 478 ptr = GET_V4(&ip6->ip6_dst); 479 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 480 ptr = GET_V4(&dst6->sin6_addr); 481 else { 482 ifa_free(&ia6->ia_ifa); 483 m_freem(m); 484 ifp->if_oerrors++; 485 return ENETUNREACH; 486 } 487 bcopy(ptr, &in4, sizeof(in4)); 488 489 if (bpf_peers_present(ifp->if_bpf)) { 490 /* 491 * We need to prepend the address family as 492 * a four byte field. Cons up a dummy header 493 * to pacify bpf. This is safe because bpf 494 * will only read from the mbuf (i.e., it won't 495 * try to free it or keep a pointer a to it). 496 */ 497 u_int af = AF_INET6; 498 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 499 } 500 501 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 502 if (m && m->m_len < sizeof(struct ip)) 503 m = m_pullup(m, sizeof(struct ip)); 504 if (m == NULL) { 505 ifa_free(&ia6->ia_ifa); 506 ifp->if_oerrors++; 507 return ENOBUFS; 508 } 509 ip = mtod(m, struct ip *); 510 511 bzero(ip, sizeof(*ip)); 512 513 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 514 &ip->ip_src, sizeof(ip->ip_src)); 515 ifa_free(&ia6->ia_ifa); 516 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 517 ip->ip_p = IPPROTO_IPV6; 518 ip->ip_ttl = ip_stf_ttl; 519 ip->ip_len = htons(m->m_pkthdr.len); 520 if (ifp->if_flags & IFF_LINK1) 521 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 522 else 523 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 524 525 if (!stf_route_cache) { 526 cached_route = NULL; 527 goto sendit; 528 } 529 530 /* 531 * Do we have a cached route? 532 */ 533 mtx_lock(&(sc)->sc_ro_mtx); 534 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 535 if (dst4->sin_family != AF_INET || 536 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 537 /* cache route doesn't match */ 538 dst4->sin_family = AF_INET; 539 dst4->sin_len = sizeof(struct sockaddr_in); 540 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 541 if (sc->sc_ro.ro_rt) { 542 RTFREE(sc->sc_ro.ro_rt); 543 sc->sc_ro.ro_rt = NULL; 544 } 545 } 546 547 if (sc->sc_ro.ro_rt == NULL) { 548 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 549 if (sc->sc_ro.ro_rt == NULL) { 550 m_freem(m); 551 mtx_unlock(&(sc)->sc_ro_mtx); 552 ifp->if_oerrors++; 553 return ENETUNREACH; 554 } 555 } 556 cached_route = &sc->sc_ro; 557 558sendit: 559 M_SETFIB(m, sc->sc_fibnum); 560 ifp->if_opackets++; 561 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 562 563 if (cached_route != NULL) 564 mtx_unlock(&(sc)->sc_ro_mtx); 565 return error; 566} 567 568static int 569isrfc1918addr(in) 570 struct in_addr *in; 571{ 572 /* 573 * returns 1 if private address range: 574 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 575 */ 576 if (stf_permit_rfc1918 == 0 && ( 577 (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 578 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 579 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)) 580 return 1; 581 582 return 0; 583} 584 585static int 586stf_checkaddr4(sc, in, inifp) 587 struct stf_softc *sc; 588 struct in_addr *in; 589 struct ifnet *inifp; /* incoming interface */ 590{ 591 struct in_ifaddr *ia4; 592 593 /* 594 * reject packets with the following address: 595 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 596 */ 597 if (IN_MULTICAST(ntohl(in->s_addr))) 598 return -1; 599 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 600 case 0: case 127: case 255: 601 return -1; 602 } 603 604 /* 605 * reject packets with private address range. 606 * (requirement from RFC3056 section 2 1st paragraph) 607 */ 608 if (isrfc1918addr(in)) 609 return -1; 610 611 /* 612 * reject packets with broadcast 613 */ 614 IN_IFADDR_RLOCK(); 615 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 616 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 617 continue; 618 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 619 IN_IFADDR_RUNLOCK(); 620 return -1; 621 } 622 } 623 IN_IFADDR_RUNLOCK(); 624 625 /* 626 * perform ingress filter 627 */ 628 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 629 struct sockaddr_in sin; 630 struct rtentry *rt; 631 632 bzero(&sin, sizeof(sin)); 633 sin.sin_family = AF_INET; 634 sin.sin_len = sizeof(struct sockaddr_in); 635 sin.sin_addr = *in; 636 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 637 0UL, sc->sc_fibnum); 638 if (!rt || rt->rt_ifp != inifp) { 639#if 0 640 log(LOG_WARNING, "%s: packet from 0x%x dropped " 641 "due to ingress filter\n", if_name(STF2IFP(sc)), 642 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 643#endif 644 if (rt) 645 RTFREE_LOCKED(rt); 646 return -1; 647 } 648 RTFREE_LOCKED(rt); 649 } 650 651 return 0; 652} 653 654static int 655stf_checkaddr6(sc, in6, inifp) 656 struct stf_softc *sc; 657 struct in6_addr *in6; 658 struct ifnet *inifp; /* incoming interface */ 659{ 660 /* 661 * check 6to4 addresses 662 */ 663 if (IN6_IS_ADDR_6TO4(in6)) { 664 struct in_addr in4; 665 bcopy(GET_V4(in6), &in4, sizeof(in4)); 666 return stf_checkaddr4(sc, &in4, inifp); 667 } 668 669 /* 670 * reject anything that look suspicious. the test is implemented 671 * in ip6_input too, but we check here as well to 672 * (1) reject bad packets earlier, and 673 * (2) to be safe against future ip6_input change. 674 */ 675 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 676 return -1; 677 678 return 0; 679} 680 681void 682in_stf_input(m, off) 683 struct mbuf *m; 684 int off; 685{ 686 int proto; 687 struct stf_softc *sc; 688 struct ip *ip; 689 struct ip6_hdr *ip6; 690 u_int8_t otos, itos; 691 struct ifnet *ifp; 692 693 proto = mtod(m, struct ip *)->ip_p; 694 695 if (proto != IPPROTO_IPV6) { 696 m_freem(m); 697 return; 698 } 699 700 ip = mtod(m, struct ip *); 701 702 sc = (struct stf_softc *)encap_getarg(m); 703 704 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 705 m_freem(m); 706 return; 707 } 708 709 ifp = STF2IFP(sc); 710 711#ifdef MAC 712 mac_ifnet_create_mbuf(ifp, m); 713#endif 714 715 /* 716 * perform sanity check against outer src/dst. 717 * for source, perform ingress filter as well. 718 */ 719 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 720 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 721 m_freem(m); 722 return; 723 } 724 725 otos = ip->ip_tos; 726 m_adj(m, off); 727 728 if (m->m_len < sizeof(*ip6)) { 729 m = m_pullup(m, sizeof(*ip6)); 730 if (!m) 731 return; 732 } 733 ip6 = mtod(m, struct ip6_hdr *); 734 735 /* 736 * perform sanity check against inner src/dst. 737 * for source, perform ingress filter as well. 738 */ 739 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 740 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 741 m_freem(m); 742 return; 743 } 744 745 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 746 if ((ifp->if_flags & IFF_LINK1) != 0) 747 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 748 else 749 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 750 ip6->ip6_flow &= ~htonl(0xff << 20); 751 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 752 753 m->m_pkthdr.rcvif = ifp; 754 755 if (bpf_peers_present(ifp->if_bpf)) { 756 /* 757 * We need to prepend the address family as 758 * a four byte field. Cons up a dummy header 759 * to pacify bpf. This is safe because bpf 760 * will only read from the mbuf (i.e., it won't 761 * try to free it or keep a pointer a to it). 762 */ 763 u_int32_t af = AF_INET6; 764 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 765 } 766 767 /* 768 * Put the packet to the network layer input queue according to the 769 * specified address family. 770 * See net/if_gif.c for possible issues with packet processing 771 * reorder due to extra queueing. 772 */ 773 ifp->if_ipackets++; 774 ifp->if_ibytes += m->m_pkthdr.len; 775 M_SETFIB(m, ifp->if_fib); 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 = rt->rt_ifp->if_mtu; 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, mtu; 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 case SIOCGIFMTU: 835 break; 836 837 case SIOCSIFMTU: 838 ifr = (struct ifreq *)data; 839 mtu = ifr->ifr_mtu; 840 /* RFC 4213 3.2 ideal world MTU */ 841 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20) 842 return (EINVAL); 843 ifp->if_mtu = mtu; 844 break; 845 846 default: 847 error = EINVAL; 848 break; 849 } 850 851 return error; 852} 853