1 /* $FreeBSD$ */ 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 #define STFUNIT 0 131 132 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 133 134 /* 135 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 136 * struct in_addr *; use bcopy() instead. 137 */ 138 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 139 140 struct stf_softc { 141 struct ifnet *sc_ifp; 142 union { 143 struct route __sc_ro4; 144 struct route_in6 __sc_ro6; /* just for safety */ 145 } __sc_ro46; 146 #define sc_ro __sc_ro46.__sc_ro4 147 struct mtx sc_ro_mtx; 148 u_int sc_fibnum; 149 const struct encaptab *encap_cookie; 150 }; 151 #define STF2IFP(sc) ((sc)->sc_ifp) 152 153 static const char stfname[] = "stf"; 154 155 /* 156 * Note that mutable fields in the softc are not currently locked. 157 * We do lock sc_ro in stf_output though. 158 */ 159 static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface"); 160 static const int ip_stf_ttl = 40; 161 162 extern struct domain inetdomain; 163 struct protosw in_stf_protosw = { 164 .pr_type = SOCK_RAW, 165 .pr_domain = &inetdomain, 166 .pr_protocol = IPPROTO_IPV6, 167 .pr_flags = PR_ATOMIC|PR_ADDR, 168 .pr_input = in_stf_input, 169 .pr_output = (pr_output_t *)rip_output, 170 .pr_ctloutput = rip_ctloutput, 171 .pr_usrreqs = &rip_usrreqs 172 }; 173 174 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 175 176 static int stfmodevent(module_t, int, void *); 177 static int stf_encapcheck(const struct mbuf *, int, int, void *); 178 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 179 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 180 struct route *); 181 static int isrfc1918addr(struct in_addr *); 182 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 183 struct ifnet *); 184 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 185 struct ifnet *); 186 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 187 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 188 189 static int stf_clone_match(struct if_clone *, const char *); 190 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 191 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 192 static struct if_clone *stf_cloner; 193 194 static int 195 stf_clone_match(struct if_clone *ifc, const char *name) 196 { 197 int i; 198 199 for(i = 0; stfnames[i] != NULL; i++) { 200 if (strcmp(stfnames[i], name) == 0) 201 return (1); 202 } 203 204 return (0); 205 } 206 207 static int 208 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 209 { 210 int err, unit; 211 struct stf_softc *sc; 212 struct ifnet *ifp; 213 214 /* 215 * We can only have one unit, but since unit allocation is 216 * already locked, we use it to keep from allocating extra 217 * interfaces. 218 */ 219 unit = STFUNIT; 220 err = ifc_alloc_unit(ifc, &unit); 221 if (err != 0) 222 return (err); 223 224 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 225 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 226 if (ifp == NULL) { 227 free(sc, M_STF); 228 ifc_free_unit(ifc, unit); 229 return (ENOSPC); 230 } 231 ifp->if_softc = sc; 232 sc->sc_fibnum = curthread->td_proc->p_fibnum; 233 234 /* 235 * Set the name manually rather then using if_initname because 236 * we don't conform to the default naming convention for interfaces. 237 */ 238 strlcpy(ifp->if_xname, name, IFNAMSIZ); 239 ifp->if_dname = stfname; 240 ifp->if_dunit = IF_DUNIT_NONE; 241 242 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF); 243 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 244 stf_encapcheck, &in_stf_protosw, sc); 245 if (sc->encap_cookie == NULL) { 246 if_printf(ifp, "attach failed\n"); 247 free(sc, M_STF); 248 ifc_free_unit(ifc, unit); 249 return (ENOMEM); 250 } 251 252 ifp->if_mtu = IPV6_MMTU; 253 ifp->if_ioctl = stf_ioctl; 254 ifp->if_output = stf_output; 255 ifp->if_snd.ifq_maxlen = ifqmaxlen; 256 if_attach(ifp); 257 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 258 return (0); 259 } 260 261 static int 262 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 263 { 264 struct stf_softc *sc = ifp->if_softc; 265 int err; 266 267 err = encap_detach(sc->encap_cookie); 268 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 269 mtx_destroy(&(sc)->sc_ro_mtx); 270 bpfdetach(ifp); 271 if_detach(ifp); 272 if_free(ifp); 273 274 free(sc, M_STF); 275 ifc_free_unit(ifc, STFUNIT); 276 277 return (0); 278 } 279 280 static int 281 stfmodevent(mod, type, data) 282 module_t mod; 283 int type; 284 void *data; 285 { 286 287 switch (type) { 288 case MOD_LOAD: 289 stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match, 290 stf_clone_create, stf_clone_destroy); 291 break; 292 case MOD_UNLOAD: 293 if_clone_detach(stf_cloner); 294 break; 295 default: 296 return (EOPNOTSUPP); 297 } 298 299 return (0); 300 } 301 302 static moduledata_t stf_mod = { 303 "if_stf", 304 stfmodevent, 305 0 306 }; 307 308 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 309 310 static int 311 stf_encapcheck(m, off, proto, arg) 312 const struct mbuf *m; 313 int off; 314 int proto; 315 void *arg; 316 { 317 struct ip ip; 318 struct in6_ifaddr *ia6; 319 struct stf_softc *sc; 320 struct in_addr a, b, mask; 321 322 sc = (struct stf_softc *)arg; 323 if (sc == NULL) 324 return 0; 325 326 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 327 return 0; 328 329 /* IFF_LINK0 means "no decapsulation" */ 330 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 331 return 0; 332 333 if (proto != IPPROTO_IPV6) 334 return 0; 335 336 /* LINTED const cast */ 337 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 338 339 if (ip.ip_v != 4) 340 return 0; 341 342 ia6 = stf_getsrcifa6(STF2IFP(sc)); 343 if (ia6 == NULL) 344 return 0; 345 346 /* 347 * check if IPv4 dst matches the IPv4 address derived from the 348 * local 6to4 address. 349 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 350 */ 351 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 352 sizeof(ip.ip_dst)) != 0) { 353 ifa_free(&ia6->ia_ifa); 354 return 0; 355 } 356 357 /* 358 * check if IPv4 src matches the IPv4 address derived from the 359 * local 6to4 address masked by prefixmask. 360 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 361 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 362 */ 363 bzero(&a, sizeof(a)); 364 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 365 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 366 ifa_free(&ia6->ia_ifa); 367 a.s_addr &= mask.s_addr; 368 b = ip.ip_src; 369 b.s_addr &= mask.s_addr; 370 if (a.s_addr != b.s_addr) 371 return 0; 372 373 /* stf interface makes single side match only */ 374 return 32; 375 } 376 377 static struct in6_ifaddr * 378 stf_getsrcifa6(ifp) 379 struct ifnet *ifp; 380 { 381 struct ifaddr *ia; 382 struct in_ifaddr *ia4; 383 struct sockaddr_in6 *sin6; 384 struct in_addr in; 385 386 if_addr_rlock(ifp); 387 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 388 if (ia->ifa_addr->sa_family != AF_INET6) 389 continue; 390 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 391 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 392 continue; 393 394 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 395 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 396 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 397 break; 398 if (ia4 == NULL) 399 continue; 400 401 ifa_ref(ia); 402 if_addr_runlock(ifp); 403 return (struct in6_ifaddr *)ia; 404 } 405 if_addr_runlock(ifp); 406 407 return NULL; 408 } 409 410 static int 411 stf_output(ifp, m, dst, ro) 412 struct ifnet *ifp; 413 struct mbuf *m; 414 struct sockaddr *dst; 415 struct route *ro; 416 { 417 struct stf_softc *sc; 418 struct sockaddr_in6 *dst6; 419 struct route *cached_route; 420 struct in_addr in4; 421 caddr_t ptr; 422 struct sockaddr_in *dst4; 423 u_int8_t tos; 424 struct ip *ip; 425 struct ip6_hdr *ip6; 426 struct in6_ifaddr *ia6; 427 u_int32_t af; 428 int error; 429 430 #ifdef MAC 431 error = mac_ifnet_check_transmit(ifp, m); 432 if (error) { 433 m_freem(m); 434 return (error); 435 } 436 #endif 437 438 sc = ifp->if_softc; 439 dst6 = (struct sockaddr_in6 *)dst; 440 441 /* just in case */ 442 if ((ifp->if_flags & IFF_UP) == 0) { 443 m_freem(m); 444 ifp->if_oerrors++; 445 return ENETDOWN; 446 } 447 448 /* 449 * If we don't have an ip4 address that match my inner ip6 address, 450 * we shouldn't generate output. Without this check, we'll end up 451 * using wrong IPv4 source. 452 */ 453 ia6 = stf_getsrcifa6(ifp); 454 if (ia6 == NULL) { 455 m_freem(m); 456 ifp->if_oerrors++; 457 return ENETDOWN; 458 } 459 460 if (m->m_len < sizeof(*ip6)) { 461 m = m_pullup(m, sizeof(*ip6)); 462 if (!m) { 463 ifa_free(&ia6->ia_ifa); 464 ifp->if_oerrors++; 465 return ENOBUFS; 466 } 467 } 468 ip6 = mtod(m, struct ip6_hdr *); 469 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 470 471 /* 472 * BPF writes need to be handled specially. 473 * This is a null operation, nothing here checks dst->sa_family. 474 */ 475 if (dst->sa_family == AF_UNSPEC) { 476 bcopy(dst->sa_data, &af, sizeof(af)); 477 dst->sa_family = af; 478 } 479 480 /* 481 * Pickup the right outer dst addr from the list of candidates. 482 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 483 */ 484 ptr = NULL; 485 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 486 ptr = GET_V4(&ip6->ip6_dst); 487 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 488 ptr = GET_V4(&dst6->sin6_addr); 489 else { 490 ifa_free(&ia6->ia_ifa); 491 m_freem(m); 492 ifp->if_oerrors++; 493 return ENETUNREACH; 494 } 495 bcopy(ptr, &in4, sizeof(in4)); 496 497 if (bpf_peers_present(ifp->if_bpf)) { 498 /* 499 * We need to prepend the address family as 500 * a four byte field. Cons up a dummy header 501 * to pacify bpf. This is safe because bpf 502 * will only read from the mbuf (i.e., it won't 503 * try to free it or keep a pointer a to it). 504 */ 505 af = AF_INET6; 506 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 507 } 508 509 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 510 if (m && m->m_len < sizeof(struct ip)) 511 m = m_pullup(m, sizeof(struct ip)); 512 if (m == NULL) { 513 ifa_free(&ia6->ia_ifa); 514 ifp->if_oerrors++; 515 return ENOBUFS; 516 } 517 ip = mtod(m, struct ip *); 518 519 bzero(ip, sizeof(*ip)); 520 521 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 522 &ip->ip_src, sizeof(ip->ip_src)); 523 ifa_free(&ia6->ia_ifa); 524 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 525 ip->ip_p = IPPROTO_IPV6; 526 ip->ip_ttl = ip_stf_ttl; 527 ip->ip_len = htons(m->m_pkthdr.len); 528 if (ifp->if_flags & IFF_LINK1) 529 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 530 else 531 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 532 533 if (!stf_route_cache) { 534 cached_route = NULL; 535 goto sendit; 536 } 537 538 /* 539 * Do we have a cached route? 540 */ 541 mtx_lock(&(sc)->sc_ro_mtx); 542 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 543 if (dst4->sin_family != AF_INET || 544 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 545 /* cache route doesn't match */ 546 dst4->sin_family = AF_INET; 547 dst4->sin_len = sizeof(struct sockaddr_in); 548 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 549 if (sc->sc_ro.ro_rt) { 550 RTFREE(sc->sc_ro.ro_rt); 551 sc->sc_ro.ro_rt = NULL; 552 } 553 } 554 555 if (sc->sc_ro.ro_rt == NULL) { 556 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 557 if (sc->sc_ro.ro_rt == NULL) { 558 m_freem(m); 559 mtx_unlock(&(sc)->sc_ro_mtx); 560 ifp->if_oerrors++; 561 return ENETUNREACH; 562 } 563 } 564 cached_route = &sc->sc_ro; 565 566 sendit: 567 M_SETFIB(m, sc->sc_fibnum); 568 ifp->if_opackets++; 569 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 570 571 if (cached_route != NULL) 572 mtx_unlock(&(sc)->sc_ro_mtx); 573 return error; 574 } 575 576 static int 577 isrfc1918addr(in) 578 struct in_addr *in; 579 { 580 /* 581 * returns 1 if private address range: 582 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 583 */ 584 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 585 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 586 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 587 return 1; 588 589 return 0; 590 } 591 592 static int 593 stf_checkaddr4(sc, in, inifp) 594 struct stf_softc *sc; 595 struct in_addr *in; 596 struct ifnet *inifp; /* incoming interface */ 597 { 598 struct in_ifaddr *ia4; 599 600 /* 601 * reject packets with the following address: 602 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 603 */ 604 if (IN_MULTICAST(ntohl(in->s_addr))) 605 return -1; 606 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 607 case 0: case 127: case 255: 608 return -1; 609 } 610 611 /* 612 * reject packets with private address range. 613 * (requirement from RFC3056 section 2 1st paragraph) 614 */ 615 if (isrfc1918addr(in)) 616 return -1; 617 618 /* 619 * reject packets with broadcast 620 */ 621 IN_IFADDR_RLOCK(); 622 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 623 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 624 continue; 625 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 626 IN_IFADDR_RUNLOCK(); 627 return -1; 628 } 629 } 630 IN_IFADDR_RUNLOCK(); 631 632 /* 633 * perform ingress filter 634 */ 635 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 636 struct sockaddr_in sin; 637 struct rtentry *rt; 638 639 bzero(&sin, sizeof(sin)); 640 sin.sin_family = AF_INET; 641 sin.sin_len = sizeof(struct sockaddr_in); 642 sin.sin_addr = *in; 643 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 644 0UL, sc->sc_fibnum); 645 if (!rt || rt->rt_ifp != inifp) { 646 #if 0 647 log(LOG_WARNING, "%s: packet from 0x%x dropped " 648 "due to ingress filter\n", if_name(STF2IFP(sc)), 649 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 650 #endif 651 if (rt) 652 RTFREE_LOCKED(rt); 653 return -1; 654 } 655 RTFREE_LOCKED(rt); 656 } 657 658 return 0; 659 } 660 661 static int 662 stf_checkaddr6(sc, in6, inifp) 663 struct stf_softc *sc; 664 struct in6_addr *in6; 665 struct ifnet *inifp; /* incoming interface */ 666 { 667 /* 668 * check 6to4 addresses 669 */ 670 if (IN6_IS_ADDR_6TO4(in6)) { 671 struct in_addr in4; 672 bcopy(GET_V4(in6), &in4, sizeof(in4)); 673 return stf_checkaddr4(sc, &in4, inifp); 674 } 675 676 /* 677 * reject anything that look suspicious. the test is implemented 678 * in ip6_input too, but we check here as well to 679 * (1) reject bad packets earlier, and 680 * (2) to be safe against future ip6_input change. 681 */ 682 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 683 return -1; 684 685 return 0; 686 } 687 688 void 689 in_stf_input(m, off) 690 struct mbuf *m; 691 int off; 692 { 693 int proto; 694 struct stf_softc *sc; 695 struct ip *ip; 696 struct ip6_hdr *ip6; 697 u_int8_t otos, itos; 698 struct ifnet *ifp; 699 700 proto = mtod(m, struct ip *)->ip_p; 701 702 if (proto != IPPROTO_IPV6) { 703 m_freem(m); 704 return; 705 } 706 707 ip = mtod(m, struct ip *); 708 709 sc = (struct stf_softc *)encap_getarg(m); 710 711 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 712 m_freem(m); 713 return; 714 } 715 716 ifp = STF2IFP(sc); 717 718 #ifdef MAC 719 mac_ifnet_create_mbuf(ifp, m); 720 #endif 721 722 /* 723 * perform sanity check against outer src/dst. 724 * for source, perform ingress filter as well. 725 */ 726 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 727 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 728 m_freem(m); 729 return; 730 } 731 732 otos = ip->ip_tos; 733 m_adj(m, off); 734 735 if (m->m_len < sizeof(*ip6)) { 736 m = m_pullup(m, sizeof(*ip6)); 737 if (!m) 738 return; 739 } 740 ip6 = mtod(m, struct ip6_hdr *); 741 742 /* 743 * perform sanity check against inner src/dst. 744 * for source, perform ingress filter as well. 745 */ 746 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 747 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 748 m_freem(m); 749 return; 750 } 751 752 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 753 if ((ifp->if_flags & IFF_LINK1) != 0) 754 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 755 else 756 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 757 ip6->ip6_flow &= ~htonl(0xff << 20); 758 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 759 760 m->m_pkthdr.rcvif = ifp; 761 762 if (bpf_peers_present(ifp->if_bpf)) { 763 /* 764 * We need to prepend the address family as 765 * a four byte field. Cons up a dummy header 766 * to pacify bpf. This is safe because bpf 767 * will only read from the mbuf (i.e., it won't 768 * try to free it or keep a pointer a to it). 769 */ 770 u_int32_t af = AF_INET6; 771 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 772 } 773 774 /* 775 * Put the packet to the network layer input queue according to the 776 * specified address family. 777 * See net/if_gif.c for possible issues with packet processing 778 * reorder due to extra queueing. 779 */ 780 ifp->if_ipackets++; 781 ifp->if_ibytes += m->m_pkthdr.len; 782 M_SETFIB(m, ifp->if_fib); 783 netisr_dispatch(NETISR_IPV6, m); 784 } 785 786 /* ARGSUSED */ 787 static void 788 stf_rtrequest(cmd, rt, info) 789 int cmd; 790 struct rtentry *rt; 791 struct rt_addrinfo *info; 792 { 793 RT_LOCK_ASSERT(rt); 794 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 795 } 796 797 static int 798 stf_ioctl(ifp, cmd, data) 799 struct ifnet *ifp; 800 u_long cmd; 801 caddr_t data; 802 { 803 struct ifaddr *ifa; 804 struct ifreq *ifr; 805 struct sockaddr_in6 *sin6; 806 struct in_addr addr; 807 int error, mtu; 808 809 error = 0; 810 switch (cmd) { 811 case SIOCSIFADDR: 812 ifa = (struct ifaddr *)data; 813 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 814 error = EAFNOSUPPORT; 815 break; 816 } 817 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 818 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 819 error = EINVAL; 820 break; 821 } 822 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 823 if (isrfc1918addr(&addr)) { 824 error = EINVAL; 825 break; 826 } 827 828 ifa->ifa_rtrequest = stf_rtrequest; 829 ifp->if_flags |= IFF_UP; 830 break; 831 832 case SIOCADDMULTI: 833 case SIOCDELMULTI: 834 ifr = (struct ifreq *)data; 835 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 836 ; 837 else 838 error = EAFNOSUPPORT; 839 break; 840 841 case SIOCGIFMTU: 842 break; 843 844 case SIOCSIFMTU: 845 ifr = (struct ifreq *)data; 846 mtu = ifr->ifr_mtu; 847 /* RFC 4213 3.2 ideal world MTU */ 848 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20) 849 return (EINVAL); 850 ifp->if_mtu = mtu; 851 break; 852 853 default: 854 error = EINVAL; 855 break; 856 } 857 858 return error; 859 } 860