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_var.h> 98 #include <net/if_clone.h> 99 #include <net/route.h> 100 #include <net/netisr.h> 101 #include <net/if_types.h> 102 #include <net/if_stf.h> 103 #include <net/vnet.h> 104 105 #include <netinet/in.h> 106 #include <netinet/in_systm.h> 107 #include <netinet/ip.h> 108 #include <netinet/ip_var.h> 109 #include <netinet/in_var.h> 110 111 #include <netinet/ip6.h> 112 #include <netinet6/ip6_var.h> 113 #include <netinet6/in6_var.h> 114 #include <netinet/ip_ecn.h> 115 116 #include <netinet/ip_encap.h> 117 118 #include <machine/stdarg.h> 119 120 #include <net/bpf.h> 121 122 #include <security/mac/mac_framework.h> 123 124 SYSCTL_DECL(_net_link); 125 static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface"); 126 127 static int stf_route_cache = 1; 128 SYSCTL_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW, 129 &stf_route_cache, 0, "Caching of IPv4 routes for 6to4 Output"); 130 131 static int stf_permit_rfc1918 = 0; 132 TUNABLE_INT("net.link.stf.permit_rfc1918", &stf_permit_rfc1918); 133 SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RW | CTLFLAG_TUN, 134 &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses"); 135 136 #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) (&(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 static const char stfname[] = "stf"; 160 161 /* 162 * Note that mutable fields in the softc are not currently locked. 163 * We do lock sc_ro in stf_output though. 164 */ 165 static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface"); 166 static const int ip_stf_ttl = 40; 167 168 extern struct domain inetdomain; 169 struct protosw in_stf_protosw = { 170 .pr_type = SOCK_RAW, 171 .pr_domain = &inetdomain, 172 .pr_protocol = IPPROTO_IPV6, 173 .pr_flags = PR_ATOMIC|PR_ADDR, 174 .pr_input = in_stf_input, 175 .pr_output = (pr_output_t *)rip_output, 176 .pr_ctloutput = rip_ctloutput, 177 .pr_usrreqs = &rip_usrreqs 178 }; 179 180 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 181 182 static int stfmodevent(module_t, int, void *); 183 static int stf_encapcheck(const struct mbuf *, int, int, void *); 184 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 185 static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *, 186 struct route *); 187 static int isrfc1918addr(struct in_addr *); 188 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 189 struct ifnet *); 190 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 191 struct ifnet *); 192 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 193 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 194 195 static int stf_clone_match(struct if_clone *, const char *); 196 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 197 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 198 static struct if_clone *stf_cloner; 199 200 static int 201 stf_clone_match(struct if_clone *ifc, const char *name) 202 { 203 int i; 204 205 for(i = 0; stfnames[i] != NULL; i++) { 206 if (strcmp(stfnames[i], name) == 0) 207 return (1); 208 } 209 210 return (0); 211 } 212 213 static int 214 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 215 { 216 int err, unit; 217 struct stf_softc *sc; 218 struct ifnet *ifp; 219 220 /* 221 * We can only have one unit, but since unit allocation is 222 * already locked, we use it to keep from allocating extra 223 * interfaces. 224 */ 225 unit = STFUNIT; 226 err = ifc_alloc_unit(ifc, &unit); 227 if (err != 0) 228 return (err); 229 230 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 231 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 232 if (ifp == NULL) { 233 free(sc, M_STF); 234 ifc_free_unit(ifc, unit); 235 return (ENOSPC); 236 } 237 ifp->if_softc = sc; 238 sc->sc_fibnum = curthread->td_proc->p_fibnum; 239 240 /* 241 * Set the name manually rather then using if_initname because 242 * we don't conform to the default naming convention for interfaces. 243 */ 244 strlcpy(ifp->if_xname, name, IFNAMSIZ); 245 ifp->if_dname = stfname; 246 ifp->if_dunit = IF_DUNIT_NONE; 247 248 mtx_init(&(sc)->sc_ro_mtx, "stf ro", NULL, MTX_DEF); 249 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 250 stf_encapcheck, &in_stf_protosw, sc); 251 if (sc->encap_cookie == NULL) { 252 if_printf(ifp, "attach failed\n"); 253 free(sc, M_STF); 254 ifc_free_unit(ifc, unit); 255 return (ENOMEM); 256 } 257 258 ifp->if_mtu = IPV6_MMTU; 259 ifp->if_ioctl = stf_ioctl; 260 ifp->if_output = stf_output; 261 ifp->if_snd.ifq_maxlen = ifqmaxlen; 262 if_attach(ifp); 263 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 264 return (0); 265 } 266 267 static int 268 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 269 { 270 struct stf_softc *sc = ifp->if_softc; 271 int err; 272 273 err = encap_detach(sc->encap_cookie); 274 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 275 mtx_destroy(&(sc)->sc_ro_mtx); 276 bpfdetach(ifp); 277 if_detach(ifp); 278 if_free(ifp); 279 280 free(sc, M_STF); 281 ifc_free_unit(ifc, STFUNIT); 282 283 return (0); 284 } 285 286 static int 287 stfmodevent(mod, type, data) 288 module_t mod; 289 int type; 290 void *data; 291 { 292 293 switch (type) { 294 case MOD_LOAD: 295 stf_cloner = if_clone_advanced(stfname, 0, stf_clone_match, 296 stf_clone_create, stf_clone_destroy); 297 break; 298 case MOD_UNLOAD: 299 if_clone_detach(stf_cloner); 300 break; 301 default: 302 return (EOPNOTSUPP); 303 } 304 305 return (0); 306 } 307 308 static moduledata_t stf_mod = { 309 "if_stf", 310 stfmodevent, 311 0 312 }; 313 314 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 315 316 static int 317 stf_encapcheck(m, off, proto, arg) 318 const struct mbuf *m; 319 int off; 320 int proto; 321 void *arg; 322 { 323 struct ip ip; 324 struct in6_ifaddr *ia6; 325 struct stf_softc *sc; 326 struct in_addr a, b, mask; 327 328 sc = (struct stf_softc *)arg; 329 if (sc == NULL) 330 return 0; 331 332 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 333 return 0; 334 335 /* IFF_LINK0 means "no decapsulation" */ 336 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 337 return 0; 338 339 if (proto != IPPROTO_IPV6) 340 return 0; 341 342 /* LINTED const cast */ 343 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 344 345 if (ip.ip_v != 4) 346 return 0; 347 348 ia6 = stf_getsrcifa6(STF2IFP(sc)); 349 if (ia6 == NULL) 350 return 0; 351 352 /* 353 * check if IPv4 dst matches the IPv4 address derived from the 354 * local 6to4 address. 355 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 356 */ 357 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 358 sizeof(ip.ip_dst)) != 0) { 359 ifa_free(&ia6->ia_ifa); 360 return 0; 361 } 362 363 /* 364 * check if IPv4 src matches the IPv4 address derived from the 365 * local 6to4 address masked by prefixmask. 366 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 367 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 368 */ 369 bzero(&a, sizeof(a)); 370 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 371 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 372 ifa_free(&ia6->ia_ifa); 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 } 382 383 static struct in6_ifaddr * 384 stf_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 if_addr_rlock(ifp); 393 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { 394 if (ia->ifa_addr->sa_family != AF_INET6) 395 continue; 396 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 397 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 398 continue; 399 400 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 401 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 402 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 403 break; 404 if (ia4 == NULL) 405 continue; 406 407 ifa_ref(ia); 408 if_addr_runlock(ifp); 409 return (struct in6_ifaddr *)ia; 410 } 411 if_addr_runlock(ifp); 412 413 return NULL; 414 } 415 416 static int 417 stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 418 struct route *ro) 419 { 420 struct stf_softc *sc; 421 const struct sockaddr_in6 *dst6; 422 struct route *cached_route; 423 struct in_addr in4; 424 const void *ptr; 425 struct sockaddr_in *dst4; 426 u_int8_t tos; 427 struct ip *ip; 428 struct ip6_hdr *ip6; 429 struct in6_ifaddr *ia6; 430 int error; 431 432 #ifdef MAC 433 error = mac_ifnet_check_transmit(ifp, m); 434 if (error) { 435 m_freem(m); 436 return (error); 437 } 438 #endif 439 440 sc = ifp->if_softc; 441 dst6 = (const struct sockaddr_in6 *)dst; 442 443 /* just in case */ 444 if ((ifp->if_flags & IFF_UP) == 0) { 445 m_freem(m); 446 ifp->if_oerrors++; 447 return ENETDOWN; 448 } 449 450 /* 451 * If we don't have an ip4 address that match my inner ip6 address, 452 * we shouldn't generate output. Without this check, we'll end up 453 * using wrong IPv4 source. 454 */ 455 ia6 = stf_getsrcifa6(ifp); 456 if (ia6 == NULL) { 457 m_freem(m); 458 ifp->if_oerrors++; 459 return ENETDOWN; 460 } 461 462 if (m->m_len < sizeof(*ip6)) { 463 m = m_pullup(m, sizeof(*ip6)); 464 if (!m) { 465 ifa_free(&ia6->ia_ifa); 466 ifp->if_oerrors++; 467 return ENOBUFS; 468 } 469 } 470 ip6 = mtod(m, struct ip6_hdr *); 471 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 472 473 /* 474 * Pickup the right outer dst addr from the list of candidates. 475 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 476 */ 477 ptr = NULL; 478 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 479 ptr = GET_V4(&ip6->ip6_dst); 480 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 481 ptr = GET_V4(&dst6->sin6_addr); 482 else { 483 ifa_free(&ia6->ia_ifa); 484 m_freem(m); 485 ifp->if_oerrors++; 486 return ENETUNREACH; 487 } 488 bcopy(ptr, &in4, sizeof(in4)); 489 490 if (bpf_peers_present(ifp->if_bpf)) { 491 /* 492 * We need to prepend the address family as 493 * a four byte field. Cons up a dummy header 494 * to pacify bpf. This is safe because bpf 495 * will only read from the mbuf (i.e., it won't 496 * try to free it or keep a pointer a to it). 497 */ 498 u_int af = AF_INET6; 499 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 500 } 501 502 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 503 if (m && m->m_len < sizeof(struct ip)) 504 m = m_pullup(m, sizeof(struct ip)); 505 if (m == NULL) { 506 ifa_free(&ia6->ia_ifa); 507 ifp->if_oerrors++; 508 return ENOBUFS; 509 } 510 ip = mtod(m, struct ip *); 511 512 bzero(ip, sizeof(*ip)); 513 514 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 515 &ip->ip_src, sizeof(ip->ip_src)); 516 ifa_free(&ia6->ia_ifa); 517 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 518 ip->ip_p = IPPROTO_IPV6; 519 ip->ip_ttl = ip_stf_ttl; 520 ip->ip_len = htons(m->m_pkthdr.len); 521 if (ifp->if_flags & IFF_LINK1) 522 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 523 else 524 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 525 526 if (!stf_route_cache) { 527 cached_route = NULL; 528 goto sendit; 529 } 530 531 /* 532 * Do we have a cached route? 533 */ 534 mtx_lock(&(sc)->sc_ro_mtx); 535 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 536 if (dst4->sin_family != AF_INET || 537 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 538 /* cache route doesn't match */ 539 dst4->sin_family = AF_INET; 540 dst4->sin_len = sizeof(struct sockaddr_in); 541 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 542 if (sc->sc_ro.ro_rt) { 543 RTFREE(sc->sc_ro.ro_rt); 544 sc->sc_ro.ro_rt = NULL; 545 } 546 } 547 548 if (sc->sc_ro.ro_rt == NULL) { 549 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 550 if (sc->sc_ro.ro_rt == NULL) { 551 m_freem(m); 552 mtx_unlock(&(sc)->sc_ro_mtx); 553 ifp->if_oerrors++; 554 return ENETUNREACH; 555 } 556 } 557 cached_route = &sc->sc_ro; 558 559 sendit: 560 M_SETFIB(m, sc->sc_fibnum); 561 ifp->if_opackets++; 562 error = ip_output(m, NULL, cached_route, 0, NULL, NULL); 563 564 if (cached_route != NULL) 565 mtx_unlock(&(sc)->sc_ro_mtx); 566 return error; 567 } 568 569 static int 570 isrfc1918addr(in) 571 struct in_addr *in; 572 { 573 /* 574 * returns 1 if private address range: 575 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 576 */ 577 if (stf_permit_rfc1918 == 0 && ( 578 (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 579 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 580 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)) 581 return 1; 582 583 return 0; 584 } 585 586 static int 587 stf_checkaddr4(sc, in, inifp) 588 struct stf_softc *sc; 589 struct in_addr *in; 590 struct ifnet *inifp; /* incoming interface */ 591 { 592 struct in_ifaddr *ia4; 593 594 /* 595 * reject packets with the following address: 596 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 597 */ 598 if (IN_MULTICAST(ntohl(in->s_addr))) 599 return -1; 600 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 601 case 0: case 127: case 255: 602 return -1; 603 } 604 605 /* 606 * reject packets with private address range. 607 * (requirement from RFC3056 section 2 1st paragraph) 608 */ 609 if (isrfc1918addr(in)) 610 return -1; 611 612 /* 613 * reject packets with broadcast 614 */ 615 IN_IFADDR_RLOCK(); 616 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 617 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 618 continue; 619 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 620 IN_IFADDR_RUNLOCK(); 621 return -1; 622 } 623 } 624 IN_IFADDR_RUNLOCK(); 625 626 /* 627 * perform ingress filter 628 */ 629 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 630 struct sockaddr_in sin; 631 struct rtentry *rt; 632 633 bzero(&sin, sizeof(sin)); 634 sin.sin_family = AF_INET; 635 sin.sin_len = sizeof(struct sockaddr_in); 636 sin.sin_addr = *in; 637 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 638 0UL, sc->sc_fibnum); 639 if (!rt || rt->rt_ifp != inifp) { 640 #if 0 641 log(LOG_WARNING, "%s: packet from 0x%x dropped " 642 "due to ingress filter\n", if_name(STF2IFP(sc)), 643 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 644 #endif 645 if (rt) 646 RTFREE_LOCKED(rt); 647 return -1; 648 } 649 RTFREE_LOCKED(rt); 650 } 651 652 return 0; 653 } 654 655 static int 656 stf_checkaddr6(sc, in6, inifp) 657 struct stf_softc *sc; 658 struct in6_addr *in6; 659 struct ifnet *inifp; /* incoming interface */ 660 { 661 /* 662 * check 6to4 addresses 663 */ 664 if (IN6_IS_ADDR_6TO4(in6)) { 665 struct in_addr in4; 666 bcopy(GET_V4(in6), &in4, sizeof(in4)); 667 return stf_checkaddr4(sc, &in4, inifp); 668 } 669 670 /* 671 * reject anything that look suspicious. the test is implemented 672 * in ip6_input too, but we check here as well to 673 * (1) reject bad packets earlier, and 674 * (2) to be safe against future ip6_input change. 675 */ 676 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 677 return -1; 678 679 return 0; 680 } 681 682 void 683 in_stf_input(m, off) 684 struct mbuf *m; 685 int off; 686 { 687 int proto; 688 struct stf_softc *sc; 689 struct ip *ip; 690 struct ip6_hdr *ip6; 691 u_int8_t otos, itos; 692 struct ifnet *ifp; 693 694 proto = mtod(m, struct ip *)->ip_p; 695 696 if (proto != IPPROTO_IPV6) { 697 m_freem(m); 698 return; 699 } 700 701 ip = mtod(m, struct ip *); 702 703 sc = (struct stf_softc *)encap_getarg(m); 704 705 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 706 m_freem(m); 707 return; 708 } 709 710 ifp = STF2IFP(sc); 711 712 #ifdef MAC 713 mac_ifnet_create_mbuf(ifp, m); 714 #endif 715 716 /* 717 * perform sanity check against outer src/dst. 718 * for source, perform ingress filter as well. 719 */ 720 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 721 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 722 m_freem(m); 723 return; 724 } 725 726 otos = ip->ip_tos; 727 m_adj(m, off); 728 729 if (m->m_len < sizeof(*ip6)) { 730 m = m_pullup(m, sizeof(*ip6)); 731 if (!m) 732 return; 733 } 734 ip6 = mtod(m, struct ip6_hdr *); 735 736 /* 737 * perform sanity check against inner src/dst. 738 * for source, perform ingress filter as well. 739 */ 740 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 741 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 742 m_freem(m); 743 return; 744 } 745 746 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 747 if ((ifp->if_flags & IFF_LINK1) != 0) 748 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 749 else 750 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 751 ip6->ip6_flow &= ~htonl(0xff << 20); 752 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 753 754 m->m_pkthdr.rcvif = ifp; 755 756 if (bpf_peers_present(ifp->if_bpf)) { 757 /* 758 * We need to prepend the address family as 759 * a four byte field. Cons up a dummy header 760 * to pacify bpf. This is safe because bpf 761 * will only read from the mbuf (i.e., it won't 762 * try to free it or keep a pointer a to it). 763 */ 764 u_int32_t af = AF_INET6; 765 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 766 } 767 768 /* 769 * Put the packet to the network layer input queue according to the 770 * specified address family. 771 * See net/if_gif.c for possible issues with packet processing 772 * reorder due to extra queueing. 773 */ 774 ifp->if_ipackets++; 775 ifp->if_ibytes += m->m_pkthdr.len; 776 M_SETFIB(m, ifp->if_fib); 777 netisr_dispatch(NETISR_IPV6, m); 778 } 779 780 /* ARGSUSED */ 781 static void 782 stf_rtrequest(cmd, rt, info) 783 int cmd; 784 struct rtentry *rt; 785 struct rt_addrinfo *info; 786 { 787 RT_LOCK_ASSERT(rt); 788 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 789 } 790 791 static int 792 stf_ioctl(ifp, cmd, data) 793 struct ifnet *ifp; 794 u_long cmd; 795 caddr_t data; 796 { 797 struct ifaddr *ifa; 798 struct ifreq *ifr; 799 struct sockaddr_in6 *sin6; 800 struct in_addr addr; 801 int error, mtu; 802 803 error = 0; 804 switch (cmd) { 805 case SIOCSIFADDR: 806 ifa = (struct ifaddr *)data; 807 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 808 error = EAFNOSUPPORT; 809 break; 810 } 811 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 812 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 813 error = EINVAL; 814 break; 815 } 816 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 817 if (isrfc1918addr(&addr)) { 818 error = EINVAL; 819 break; 820 } 821 822 ifa->ifa_rtrequest = stf_rtrequest; 823 ifp->if_flags |= IFF_UP; 824 break; 825 826 case SIOCADDMULTI: 827 case SIOCDELMULTI: 828 ifr = (struct ifreq *)data; 829 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 830 ; 831 else 832 error = EAFNOSUPPORT; 833 break; 834 835 case SIOCGIFMTU: 836 break; 837 838 case SIOCSIFMTU: 839 ifr = (struct ifreq *)data; 840 mtu = ifr->ifr_mtu; 841 /* RFC 4213 3.2 ideal world MTU */ 842 if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20) 843 return (EINVAL); 844 ifp->if_mtu = mtu; 845 break; 846 847 default: 848 error = EINVAL; 849 break; 850 } 851 852 return error; 853 } 854