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sys/net/if_stf.c
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1 /* $FreeBSD: releng/9.2/sys/net/if_stf.c 248743 2013-03-26 18:57:25Z melifaro $ */ 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> 122 123 SYSCTL_DECL(_net_link); 124 static 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 static int stf_permit_rfc1918 = 0; 131 TUNABLE_INT("net.link.stf.permit_rfc1918", &stf_permit_rfc1918); 132 SYSCTL_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 STFNAME "stf" 136 #define STFUNIT 0 137 138 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 139 140 /* 141 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 142 * struct in_addr *; use bcopy() instead. 143 */ 144 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 145 146 struct stf_softc { 147 struct ifnet *sc_ifp; 148 union { 149 struct route __sc_ro4; 150 struct route_in6 __sc_ro6; /* just for safety */ 151 } __sc_ro46; 152 #define sc_ro __sc_ro46.__sc_ro4 153 struct mtx sc_ro_mtx; 154 u_int sc_fibnum; 155 const struct encaptab *encap_cookie; 156 }; 157 #define STF2IFP(sc) ((sc)->sc_ifp) 158 159 /* 160 * Note that mutable fields in the softc are not currently locked. 161 * We do lock sc_ro in stf_output though. 162 */ 163 static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 164 static const int ip_stf_ttl = 40; 165 166 extern struct domain inetdomain; 167 struct protosw in_stf_protosw = { 168 .pr_type = SOCK_RAW, 169 .pr_domain = &inetdomain, 170 .pr_protocol = IPPROTO_IPV6, 171 .pr_flags = PR_ATOMIC|PR_ADDR, 172 .pr_input = in_stf_input, 173 .pr_output = (pr_output_t *)rip_output, 174 .pr_ctloutput = rip_ctloutput, 175 .pr_usrreqs = &rip_usrreqs 176 }; 177 178 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 179 180 static int stfmodevent(module_t, int, void *); 181 static int stf_encapcheck(const struct mbuf *, int, int, void *); 182 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 183 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 184 struct route *); 185 static int isrfc1918addr(struct in_addr *); 186 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 187 struct ifnet *); 188 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 189 struct ifnet *); 190 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 191 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 192 193 static int stf_clone_match(struct if_clone *, const char *); 194 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 195 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 196 struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 197 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 198 199 static int 200 stf_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 } 211 212 static int 213 stf_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 = ifc->ifc_name; 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 } 265 266 static int 267 stf_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 } 284 285 static int 286 stfmodevent(mod, type, data) 287 module_t mod; 288 int type; 289 void *data; 290 { 291 292 switch (type) { 293 case MOD_LOAD: 294 if_clone_attach(&stf_cloner); 295 break; 296 case MOD_UNLOAD: 297 if_clone_detach(&stf_cloner); 298 break; 299 default: 300 return (EOPNOTSUPP); 301 } 302 303 return (0); 304 } 305 306 static moduledata_t stf_mod = { 307 "if_stf", 308 stfmodevent, 309 0 310 }; 311 312 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 313 314 static int 315 stf_encapcheck(m, off, proto, arg) 316 const struct mbuf *m; 317 int off; 318 int proto; 319 void *arg; 320 { 321 struct ip ip; 322 struct in6_ifaddr *ia6; 323 struct stf_softc *sc; 324 struct in_addr a, b, mask; 325 326 sc = (struct stf_softc *)arg; 327 if (sc == NULL) 328 return 0; 329 330 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 331 return 0; 332 333 /* IFF_LINK0 means "no decapsulation" */ 334 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 335 return 0; 336 337 if (proto != IPPROTO_IPV6) 338 return 0; 339 340 /* LINTED const cast */ 341 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 342 343 if (ip.ip_v != 4) 344 return 0; 345 346 ia6 = stf_getsrcifa6(STF2IFP(sc)); 347 if (ia6 == NULL) 348 return 0; 349 350 /* 351 * check if IPv4 dst matches the IPv4 address derived from the 352 * local 6to4 address. 353 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 354 */ 355 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 356 sizeof(ip.ip_dst)) != 0) { 357 ifa_free(&ia6->ia_ifa); 358 return 0; 359 } 360 361 /* 362 * check if IPv4 src matches the IPv4 address derived from the 363 * local 6to4 address masked by prefixmask. 364 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 365 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 366 */ 367 bzero(&a, sizeof(a)); 368 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 369 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 370 ifa_free(&ia6->ia_ifa); 371 a.s_addr &= mask.s_addr; 372 b = ip.ip_src; 373 b.s_addr &= mask.s_addr; 374 if (a.s_addr != b.s_addr) 375 return 0; 376 377 /* stf interface makes single side match only */ 378 return 32; 379 } 380 381 static struct in6_ifaddr * 382 stf_getsrcifa6(ifp) 383 struct ifnet *ifp; 384 { 385 struct ifaddr *ia; 386 struct in_ifaddr *ia4; 387 struct sockaddr_in6 *sin6; 388 struct in_addr in; 389 390 if_addr_rlock(ifp); 391 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 392 if (ia->ifa_addr->sa_family != AF_INET6) 393 continue; 394 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 395 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 396 continue; 397 398 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 399 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 400 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 401 break; 402 if (ia4 == NULL) 403 continue; 404 405 ifa_ref(ia); 406 if_addr_runlock(ifp); 407 return (struct in6_ifaddr *)ia; 408 } 409 if_addr_runlock(ifp); 410 411 return NULL; 412 } 413 414 static int 415 stf_output(ifp, m, dst, ro) 416 struct ifnet *ifp; 417 struct mbuf *m; 418 struct sockaddr *dst; 419 struct route *ro; 420 { 421 struct stf_softc *sc; 422 struct sockaddr_in6 *dst6; 423 struct route *cached_route; 424 struct in_addr in4; 425 caddr_t ptr; 426 struct sockaddr_in *dst4; 427 u_int8_t tos; 428 struct ip *ip; 429 struct ip6_hdr *ip6; 430 struct in6_ifaddr *ia6; 431 u_int32_t af; 432 int error; 433 434 #ifdef MAC 435 error = mac_ifnet_check_transmit(ifp, m); 436 if (error) { 437 m_freem(m); 438 return (error); 439 } 440 #endif 441 442 sc = ifp->if_softc; 443 dst6 = (struct sockaddr_in6 *)dst; 444 445 /* just in case */ 446 if ((ifp->if_flags & IFF_UP) == 0) { 447 m_freem(m); 448 ifp->if_oerrors++; 449 return ENETDOWN; 450 } 451 452 /* 453 * If we don't have an ip4 address that match my inner ip6 address, 454 * we shouldn't generate output. Without this check, we'll end up 455 * using wrong IPv4 source. 456 */ 457 ia6 = stf_getsrcifa6(ifp); 458 if (ia6 == NULL) { 459 m_freem(m); 460 ifp->if_oerrors++; 461 return ENETDOWN; 462 } 463 464 if (m->m_len < sizeof(*ip6)) { 465 m = m_pullup(m, sizeof(*ip6)); 466 if (!m) { 467 ifa_free(&ia6->ia_ifa); 468 ifp->if_oerrors++; 469 return ENOBUFS; 470 } 471 } 472 ip6 = mtod(m, struct ip6_hdr *); 473 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 474 475 /* 476 * BPF writes need to be handled specially. 477 * This is a null operation, nothing here checks dst->sa_family. 478 */ 479 if (dst->sa_family == AF_UNSPEC) { 480 bcopy(dst->sa_data, &af, sizeof(af)); 481 dst->sa_family = af; 482 } 483 484 /* 485 * Pickup the right outer dst addr from the list of candidates. 486 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 487 */ 488 ptr = NULL; 489 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 490 ptr = GET_V4(&ip6->ip6_dst); 491 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 492 ptr = GET_V4(&dst6->sin6_addr); 493 else { 494 ifa_free(&ia6->ia_ifa); 495 m_freem(m); 496 ifp->if_oerrors++; 497 return ENETUNREACH; 498 } 499 bcopy(ptr, &in4, sizeof(in4)); 500 501 if (bpf_peers_present(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 ifa_free(&ia6->ia_ifa); 518 ifp->if_oerrors++; 519 return ENOBUFS; 520 } 521 ip = mtod(m, struct ip *); 522 523 bzero(ip, sizeof(*ip)); 524 525 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 526 &ip->ip_src, sizeof(ip->ip_src)); 527 ifa_free(&ia6->ia_ifa); 528 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 529 ip->ip_p = IPPROTO_IPV6; 530 ip->ip_ttl = ip_stf_ttl; 531 ip->ip_len = m->m_pkthdr.len; /*host order*/ 532 if (ifp->if_flags & IFF_LINK1) 533 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 534 else 535 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 536 537 if (!stf_route_cache) { 538 cached_route = NULL; 539 goto sendit; 540 } 541 542 /* 543 * Do we have a cached route? 544 */ 545 mtx_lock(&(sc)->sc_ro_mtx); 546 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 547 if (dst4->sin_family != AF_INET || 548 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 549 /* cache route doesn't match */ 550 dst4->sin_family = AF_INET; 551 dst4->sin_len = sizeof(struct sockaddr_in); 552 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 553 if (sc->sc_ro.ro_rt) { 554 RTFREE(sc->sc_ro.ro_rt); 555 sc->sc_ro.ro_rt = NULL; 556 } 557 } 558 559 if (sc->sc_ro.ro_rt == NULL) { 560 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 561 if (sc->sc_ro.ro_rt == NULL) { 562 m_freem(m); 563 mtx_unlock(&(sc)->sc_ro_mtx); 564 ifp->if_oerrors++; 565 return ENETUNREACH; 566 } 567 } 568 cached_route = &sc->sc_ro; 569 570 sendit: 571 M_SETFIB(m, sc->sc_fibnum); 572 ifp->if_opackets++; 573 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 574 575 if (cached_route != NULL) 576 mtx_unlock(&(sc)->sc_ro_mtx); 577 return error; 578 } 579 580 static int 581 isrfc1918addr(in) 582 struct in_addr *in; 583 { 584 /* 585 * returns 1 if private address range: 586 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 587 */ 588 if (stf_permit_rfc1918 == 0 && ( 589 (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 590 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 591 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)) 592 return 1; 593 594 return 0; 595 } 596 597 static int 598 stf_checkaddr4(sc, in, inifp) 599 struct stf_softc *sc; 600 struct in_addr *in; 601 struct ifnet *inifp; /* incoming interface */ 602 { 603 struct in_ifaddr *ia4; 604 605 /* 606 * reject packets with the following address: 607 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 608 */ 609 if (IN_MULTICAST(ntohl(in->s_addr))) 610 return -1; 611 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 612 case 0: case 127: case 255: 613 return -1; 614 } 615 616 /* 617 * reject packets with private address range. 618 * (requirement from RFC3056 section 2 1st paragraph) 619 */ 620 if (isrfc1918addr(in)) 621 return -1; 622 623 /* 624 * reject packets with broadcast 625 */ 626 IN_IFADDR_RLOCK(); 627 for (ia4 = TAILQ_FIRST(&V_in_ifaddrhead); 628 ia4; 629 ia4 = TAILQ_NEXT(ia4, ia_link)) 630 { 631 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 632 continue; 633 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 634 IN_IFADDR_RUNLOCK(); 635 return -1; 636 } 637 } 638 IN_IFADDR_RUNLOCK(); 639 640 /* 641 * perform ingress filter 642 */ 643 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 644 struct sockaddr_in sin; 645 struct rtentry *rt; 646 647 bzero(&sin, sizeof(sin)); 648 sin.sin_family = AF_INET; 649 sin.sin_len = sizeof(struct sockaddr_in); 650 sin.sin_addr = *in; 651 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 652 0UL, sc->sc_fibnum); 653 if (!rt || rt->rt_ifp != inifp) { 654 #if 0 655 log(LOG_WARNING, "%s: packet from 0x%x dropped " 656 "due to ingress filter\n", if_name(STF2IFP(sc)), 657 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 658 #endif 659 if (rt) 660 RTFREE_LOCKED(rt); 661 return -1; 662 } 663 RTFREE_LOCKED(rt); 664 } 665 666 return 0; 667 } 668 669 static int 670 stf_checkaddr6(sc, in6, inifp) 671 struct stf_softc *sc; 672 struct in6_addr *in6; 673 struct ifnet *inifp; /* incoming interface */ 674 { 675 /* 676 * check 6to4 addresses 677 */ 678 if (IN6_IS_ADDR_6TO4(in6)) { 679 struct in_addr in4; 680 bcopy(GET_V4(in6), &in4, sizeof(in4)); 681 return stf_checkaddr4(sc, &in4, inifp); 682 } 683 684 /* 685 * reject anything that look suspicious. the test is implemented 686 * in ip6_input too, but we check here as well to 687 * (1) reject bad packets earlier, and 688 * (2) to be safe against future ip6_input change. 689 */ 690 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 691 return -1; 692 693 return 0; 694 } 695 696 void 697 in_stf_input(m, off) 698 struct mbuf *m; 699 int off; 700 { 701 int proto; 702 struct stf_softc *sc; 703 struct ip *ip; 704 struct ip6_hdr *ip6; 705 u_int8_t otos, itos; 706 struct ifnet *ifp; 707 708 proto = mtod(m, struct ip *)->ip_p; 709 710 if (proto != IPPROTO_IPV6) { 711 m_freem(m); 712 return; 713 } 714 715 ip = mtod(m, struct ip *); 716 717 sc = (struct stf_softc *)encap_getarg(m); 718 719 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 720 m_freem(m); 721 return; 722 } 723 724 ifp = STF2IFP(sc); 725 726 #ifdef MAC 727 mac_ifnet_create_mbuf(ifp, m); 728 #endif 729 730 /* 731 * perform sanity check against outer src/dst. 732 * for source, perform ingress filter as well. 733 */ 734 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 735 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 736 m_freem(m); 737 return; 738 } 739 740 otos = ip->ip_tos; 741 m_adj(m, off); 742 743 if (m->m_len < sizeof(*ip6)) { 744 m = m_pullup(m, sizeof(*ip6)); 745 if (!m) 746 return; 747 } 748 ip6 = mtod(m, struct ip6_hdr *); 749 750 /* 751 * perform sanity check against inner src/dst. 752 * for source, perform ingress filter as well. 753 */ 754 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 755 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 756 m_freem(m); 757 return; 758 } 759 760 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 761 if ((ifp->if_flags & IFF_LINK1) != 0) 762 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 763 else 764 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 765 ip6->ip6_flow &= ~htonl(0xff << 20); 766 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 767 768 m->m_pkthdr.rcvif = ifp; 769 770 if (bpf_peers_present(ifp->if_bpf)) { 771 /* 772 * We need to prepend the address family as 773 * a four byte field. Cons up a dummy header 774 * to pacify bpf. This is safe because bpf 775 * will only read from the mbuf (i.e., it won't 776 * try to free it or keep a pointer a to it). 777 */ 778 u_int32_t af = AF_INET6; 779 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 780 } 781 782 /* 783 * Put the packet to the network layer input queue according to the 784 * specified address family. 785 * See net/if_gif.c for possible issues with packet processing 786 * reorder due to extra queueing. 787 */ 788 ifp->if_ipackets++; 789 ifp->if_ibytes += m->m_pkthdr.len; 790 M_SETFIB(m, ifp->if_fib); 791 netisr_dispatch(NETISR_IPV6, m); 792 } 793 794 /* ARGSUSED */ 795 static void 796 stf_rtrequest(cmd, rt, info) 797 int cmd; 798 struct rtentry *rt; 799 struct rt_addrinfo *info; 800 { 801 RT_LOCK_ASSERT(rt); 802 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 803 } 804 805 static int 806 stf_ioctl(ifp, cmd, data) 807 struct ifnet *ifp; 808 u_long cmd; 809 caddr_t data; 810 { 811 struct ifaddr *ifa; 812 struct ifreq *ifr; 813 struct sockaddr_in6 *sin6; 814 struct in_addr addr; 815 int error, mtu; 816 817 error = 0; 818 switch (cmd) { 819 case SIOCSIFADDR: 820 ifa = (struct ifaddr *)data; 821 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 822 error = EAFNOSUPPORT; 823 break; 824 } 825 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 826 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 827 error = EINVAL; 828 break; 829 } 830 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 831 if (isrfc1918addr(&addr)) { 832 error = EINVAL; 833 break; 834 } 835 836 ifa->ifa_rtrequest = stf_rtrequest; 837 ifp->if_flags |= IFF_UP; 838 break; 839 840 case SIOCADDMULTI: 841 case SIOCDELMULTI: 842 ifr = (struct ifreq *)data; 843 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 844 ; 845 else 846 error = EAFNOSUPPORT; 847 break; 848 849 case SIOCGIFMTU: 850 break; 851 852 case SIOCSIFMTU: 853 ifr = (struct ifreq *)data; 854 mtu = ifr->ifr_mtu; 855 /* RFC 4213 3.2 ideal world MTU */ 856 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20) 857 return (EINVAL); 858 ifp->if_mtu = mtu; 859 break; 860 861 default: 862 error = EINVAL; 863 break; 864 } 865 866 return error; 867 }
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