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 #include "opt_mac.h" 80 81 #include <sys/param.h> 82 #include <sys/systm.h> 83 #include <sys/socket.h> 84 #include <sys/sockio.h> 85 #include <sys/mac.h> 86 #include <sys/mbuf.h> 87 #include <sys/errno.h> 88 #include <sys/kernel.h> 89 #include <sys/module.h> 90 #include <sys/protosw.h> 91 #include <sys/queue.h> 92 #include <machine/cpu.h> 93 94 #include <sys/malloc.h> 95 96 #include <net/if.h> 97 #include <net/if_clone.h> 98 #include <net/route.h> 99 #include <net/netisr.h> 100 #include <net/if_types.h> 101 #include <net/if_stf.h> 102 103 #include <netinet/in.h> 104 #include <netinet/in_systm.h> 105 #include <netinet/ip.h> 106 #include <netinet/ip_var.h> 107 #include <netinet/in_var.h> 108 109 #include <netinet/ip6.h> 110 #include <netinet6/ip6_var.h> 111 #include <netinet6/in6_var.h> 112 #include <netinet/ip_ecn.h> 113 114 #include <netinet/ip_encap.h> 115 116 #include <machine/stdarg.h> 117 118 #include <net/net_osdep.h> 119 120 #include <net/bpf.h> 121 122 #define STFNAME "stf" 123 #define STFUNIT 0 124 125 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 126 127 /* 128 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 129 * struct in_addr *; use bcopy() instead. 130 */ 131 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 132 133 struct stf_softc { 134 struct ifnet sc_if; /* common area */ 135 union { 136 struct route __sc_ro4; 137 struct route_in6 __sc_ro6; /* just for safety */ 138 } __sc_ro46; 139 #define sc_ro __sc_ro46.__sc_ro4 140 const struct encaptab *encap_cookie; 141 LIST_ENTRY(stf_softc) sc_list; /* all stf's are linked */ 142 }; 143 144 /* 145 * All mutable global variables in if_stf.c are protected by stf_mtx. 146 * XXXRW: Note that mutable fields in the softc are not currently locked: 147 * in particular, sc_ro needs to be protected from concurrent entrance 148 * of stf_output(). 149 */ 150 static struct mtx stf_mtx; 151 static LIST_HEAD(, stf_softc) stf_softc_list; 152 153 static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 154 static const int ip_stf_ttl = 40; 155 156 extern struct domain inetdomain; 157 struct protosw in_stf_protosw = 158 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 159 in_stf_input, (pr_output_t*)rip_output, 0, rip_ctloutput, 160 0, 161 0, 0, 0, 0, 162 &rip_usrreqs 163 }; 164 165 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 166 167 static int stfmodevent(module_t, int, void *); 168 static int stf_encapcheck(const struct mbuf *, int, int, void *); 169 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 170 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 171 struct rtentry *); 172 static int isrfc1918addr(struct in_addr *); 173 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 174 struct ifnet *); 175 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 176 struct ifnet *); 177 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 178 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 179 180 static int stf_clone_match(struct if_clone *, const char *); 181 static int stf_clone_create(struct if_clone *, char *, size_t); 182 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 183 struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 184 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 185 186 static int 187 stf_clone_match(struct if_clone *ifc, const char *name) 188 { 189 int i; 190 191 for(i = 0; stfnames[i] != NULL; i++) { 192 if (strcmp(stfnames[i], name) == 0) 193 return (1); 194 } 195 196 return (0); 197 } 198 199 static int 200 stf_clone_create(struct if_clone *ifc, char *name, size_t len) 201 { 202 int err, unit; 203 struct stf_softc *sc; 204 struct ifnet *ifp; 205 206 /* 207 * We can only have one unit, but since unit allocation is 208 * already locked, we use it to keep from allocating extra 209 * interfaces. 210 */ 211 unit = STFUNIT; 212 err = ifc_alloc_unit(ifc, &unit); 213 if (err != 0) 214 return (err); 215 216 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 217 ifp = &sc->sc_if; 218 /* 219 * Set the name manually rather then using if_initname because 220 * we don't conform to the default naming convention for interfaces. 221 */ 222 strlcpy(ifp->if_xname, name, IFNAMSIZ); 223 ifp->if_dname = ifc->ifc_name; 224 ifp->if_dunit = IF_DUNIT_NONE; 225 226 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 227 stf_encapcheck, &in_stf_protosw, sc); 228 if (sc->encap_cookie == NULL) { 229 if_printf(ifp, "attach failed\n"); 230 free(sc, M_STF); 231 ifc_free_unit(ifc, unit); 232 return (ENOMEM); 233 } 234 235 ifp->if_mtu = IPV6_MMTU; 236 ifp->if_ioctl = stf_ioctl; 237 ifp->if_output = stf_output; 238 ifp->if_type = IFT_STF; 239 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN; 240 if_attach(ifp); 241 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 242 mtx_lock(&stf_mtx); 243 LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list); 244 mtx_unlock(&stf_mtx); 245 return (0); 246 } 247 248 static void 249 stf_destroy(struct stf_softc *sc) 250 { 251 int err; 252 253 err = encap_detach(sc->encap_cookie); 254 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 255 bpfdetach(&sc->sc_if); 256 if_detach(&sc->sc_if); 257 258 free(sc, M_STF); 259 } 260 261 static int 262 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 263 { 264 struct stf_softc *sc = (void *) ifp; 265 266 mtx_lock(&stf_mtx); 267 LIST_REMOVE(sc, sc_list); 268 mtx_unlock(&stf_mtx); 269 270 stf_destroy(sc); 271 ifc_free_unit(ifc, STFUNIT); 272 273 return (0); 274 } 275 276 static int 277 stfmodevent(mod, type, data) 278 module_t mod; 279 int type; 280 void *data; 281 { 282 struct stf_softc *sc; 283 284 switch (type) { 285 case MOD_LOAD: 286 mtx_init(&stf_mtx, "stf_mtx", NULL, MTX_DEF); 287 LIST_INIT(&stf_softc_list); 288 if_clone_attach(&stf_cloner); 289 290 break; 291 case MOD_UNLOAD: 292 if_clone_detach(&stf_cloner); 293 294 mtx_lock(&stf_mtx); 295 while ((sc = LIST_FIRST(&stf_softc_list)) != NULL) { 296 LIST_REMOVE(sc, sc_list); 297 mtx_unlock(&stf_mtx); 298 stf_destroy(sc); 299 mtx_lock(&stf_mtx); 300 } 301 mtx_unlock(&stf_mtx); 302 mtx_destroy(&stf_mtx); 303 break; 304 } 305 306 return (0); 307 } 308 309 static moduledata_t stf_mod = { 310 "if_stf", 311 stfmodevent, 312 0 313 }; 314 315 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 316 317 static int 318 stf_encapcheck(m, off, proto, arg) 319 const struct mbuf *m; 320 int off; 321 int proto; 322 void *arg; 323 { 324 struct ip ip; 325 struct in6_ifaddr *ia6; 326 struct stf_softc *sc; 327 struct in_addr a, b, mask; 328 329 sc = (struct stf_softc *)arg; 330 if (sc == NULL) 331 return 0; 332 333 if ((sc->sc_if.if_flags & IFF_UP) == 0) 334 return 0; 335 336 /* IFF_LINK0 means "no decapsulation" */ 337 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 338 return 0; 339 340 if (proto != IPPROTO_IPV6) 341 return 0; 342 343 /* LINTED const cast */ 344 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 345 346 if (ip.ip_v != 4) 347 return 0; 348 349 ia6 = stf_getsrcifa6(&sc->sc_if); 350 if (ia6 == NULL) 351 return 0; 352 353 /* 354 * check if IPv4 dst matches the IPv4 address derived from the 355 * local 6to4 address. 356 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 357 */ 358 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 359 sizeof(ip.ip_dst)) != 0) 360 return 0; 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 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 for (ia = TAILQ_FIRST(&ifp->if_addrlist); 391 ia; 392 ia = TAILQ_NEXT(ia, ifa_list)) 393 { 394 if (ia->ifa_addr == NULL) 395 continue; 396 if (ia->ifa_addr->sa_family != AF_INET6) 397 continue; 398 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 399 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 400 continue; 401 402 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 403 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 404 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 405 break; 406 if (ia4 == NULL) 407 continue; 408 409 return (struct in6_ifaddr *)ia; 410 } 411 412 return NULL; 413 } 414 415 static int 416 stf_output(ifp, m, dst, rt) 417 struct ifnet *ifp; 418 struct mbuf *m; 419 struct sockaddr *dst; 420 struct rtentry *rt; 421 { 422 struct stf_softc *sc; 423 struct sockaddr_in6 *dst6; 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 #ifdef MAC 432 int error; 433 434 error = mac_check_ifnet_transmit(ifp, m); 435 if (error) { 436 m_freem(m); 437 return (error); 438 } 439 #endif 440 441 sc = (struct stf_softc*)ifp; 442 dst6 = (struct sockaddr_in6 *)dst; 443 444 /* just in case */ 445 if ((ifp->if_flags & IFF_UP) == 0) { 446 m_freem(m); 447 ifp->if_oerrors++; 448 return ENETDOWN; 449 } 450 451 /* 452 * If we don't have an ip4 address that match my inner ip6 address, 453 * we shouldn't generate output. Without this check, we'll end up 454 * using wrong IPv4 source. 455 */ 456 ia6 = stf_getsrcifa6(ifp); 457 if (ia6 == NULL) { 458 m_freem(m); 459 ifp->if_oerrors++; 460 return ENETDOWN; 461 } 462 463 if (m->m_len < sizeof(*ip6)) { 464 m = m_pullup(m, sizeof(*ip6)); 465 if (!m) { 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 m_freem(m); 484 ifp->if_oerrors++; 485 return ENETUNREACH; 486 } 487 bcopy(ptr, &in4, sizeof(in4)); 488 489 #if NBPFILTER > 0 490 if (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_int32_t af = AF_INET6; 499 #ifdef HAVE_OLD_BPF 500 struct mbuf m0; 501 502 m0.m_next = m; 503 m0.m_len = 4; 504 m0.m_data = (char *)⁡ 505 506 BPF_MTAP(ifp, &m0); 507 #else 508 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 509 #endif 510 } 511 #endif /*NBPFILTER > 0*/ 512 513 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 514 if (m && m->m_len < sizeof(struct ip)) 515 m = m_pullup(m, sizeof(struct ip)); 516 if (m == NULL) { 517 ifp->if_oerrors++; 518 return ENOBUFS; 519 } 520 ip = mtod(m, struct ip *); 521 522 bzero(ip, sizeof(*ip)); 523 524 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 525 &ip->ip_src, sizeof(ip->ip_src)); 526 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 527 ip->ip_p = IPPROTO_IPV6; 528 ip->ip_ttl = ip_stf_ttl; 529 ip->ip_len = m->m_pkthdr.len; /*host order*/ 530 if (ifp->if_flags & IFF_LINK1) 531 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 532 else 533 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 534 535 /* 536 * XXXRW: Locking of sc_ro required. 537 */ 538 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 539 if (dst4->sin_family != AF_INET || 540 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 541 /* cache route doesn't match */ 542 dst4->sin_family = AF_INET; 543 dst4->sin_len = sizeof(struct sockaddr_in); 544 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 545 if (sc->sc_ro.ro_rt) { 546 RTFREE(sc->sc_ro.ro_rt); 547 sc->sc_ro.ro_rt = NULL; 548 } 549 } 550 551 if (sc->sc_ro.ro_rt == NULL) { 552 rtalloc(&sc->sc_ro); 553 if (sc->sc_ro.ro_rt == NULL) { 554 m_freem(m); 555 ifp->if_oerrors++; 556 return ENETUNREACH; 557 } 558 } 559 560 ifp->if_opackets++; 561 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 562 } 563 564 static int 565 isrfc1918addr(in) 566 struct in_addr *in; 567 { 568 /* 569 * returns 1 if private address range: 570 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 571 */ 572 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 573 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 574 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 575 return 1; 576 577 return 0; 578 } 579 580 static int 581 stf_checkaddr4(sc, in, inifp) 582 struct stf_softc *sc; 583 struct in_addr *in; 584 struct ifnet *inifp; /* incoming interface */ 585 { 586 struct in_ifaddr *ia4; 587 588 /* 589 * reject packets with the following address: 590 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 591 */ 592 if (IN_MULTICAST(ntohl(in->s_addr))) 593 return -1; 594 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 595 case 0: case 127: case 255: 596 return -1; 597 } 598 599 /* 600 * reject packets with private address range. 601 * (requirement from RFC3056 section 2 1st paragraph) 602 */ 603 if (isrfc1918addr(in)) 604 return -1; 605 606 /* 607 * reject packets with broadcast 608 */ 609 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 610 ia4; 611 ia4 = TAILQ_NEXT(ia4, ia_link)) 612 { 613 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 614 continue; 615 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 616 return -1; 617 } 618 619 /* 620 * perform ingress filter 621 */ 622 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 623 struct sockaddr_in sin; 624 struct rtentry *rt; 625 626 bzero(&sin, sizeof(sin)); 627 sin.sin_family = AF_INET; 628 sin.sin_len = sizeof(struct sockaddr_in); 629 sin.sin_addr = *in; 630 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 631 if (!rt || rt->rt_ifp != inifp) { 632 #if 0 633 log(LOG_WARNING, "%s: packet from 0x%x dropped " 634 "due to ingress filter\n", if_name(&sc->sc_if), 635 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 636 #endif 637 if (rt) 638 rtfree(rt); 639 return -1; 640 } 641 rtfree(rt); 642 } 643 644 return 0; 645 } 646 647 static int 648 stf_checkaddr6(sc, in6, inifp) 649 struct stf_softc *sc; 650 struct in6_addr *in6; 651 struct ifnet *inifp; /* incoming interface */ 652 { 653 /* 654 * check 6to4 addresses 655 */ 656 if (IN6_IS_ADDR_6TO4(in6)) { 657 struct in_addr in4; 658 bcopy(GET_V4(in6), &in4, sizeof(in4)); 659 return stf_checkaddr4(sc, &in4, inifp); 660 } 661 662 /* 663 * reject anything that look suspicious. the test is implemented 664 * in ip6_input too, but we check here as well to 665 * (1) reject bad packets earlier, and 666 * (2) to be safe against future ip6_input change. 667 */ 668 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 669 return -1; 670 671 return 0; 672 } 673 674 void 675 in_stf_input(m, off) 676 struct mbuf *m; 677 int off; 678 { 679 int proto; 680 struct stf_softc *sc; 681 struct ip *ip; 682 struct ip6_hdr *ip6; 683 u_int8_t otos, itos; 684 struct ifnet *ifp; 685 686 proto = mtod(m, struct ip *)->ip_p; 687 688 if (proto != IPPROTO_IPV6) { 689 m_freem(m); 690 return; 691 } 692 693 ip = mtod(m, struct ip *); 694 695 sc = (struct stf_softc *)encap_getarg(m); 696 697 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 698 m_freem(m); 699 return; 700 } 701 702 ifp = &sc->sc_if; 703 704 #ifdef MAC 705 mac_create_mbuf_from_ifnet(ifp, m); 706 #endif 707 708 /* 709 * perform sanity check against outer src/dst. 710 * for source, perform ingress filter as well. 711 */ 712 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 713 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 714 m_freem(m); 715 return; 716 } 717 718 otos = ip->ip_tos; 719 m_adj(m, off); 720 721 if (m->m_len < sizeof(*ip6)) { 722 m = m_pullup(m, sizeof(*ip6)); 723 if (!m) 724 return; 725 } 726 ip6 = mtod(m, struct ip6_hdr *); 727 728 /* 729 * perform sanity check against inner src/dst. 730 * for source, perform ingress filter as well. 731 */ 732 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 733 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 734 m_freem(m); 735 return; 736 } 737 738 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 739 if ((ifp->if_flags & IFF_LINK1) != 0) 740 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 741 else 742 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 743 ip6->ip6_flow &= ~htonl(0xff << 20); 744 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 745 746 m->m_pkthdr.rcvif = ifp; 747 748 if (ifp->if_bpf) { 749 /* 750 * We need to prepend the address family as 751 * a four byte field. Cons up a dummy header 752 * to pacify bpf. This is safe because bpf 753 * will only read from the mbuf (i.e., it won't 754 * try to free it or keep a pointer a to it). 755 */ 756 u_int32_t af = AF_INET6; 757 #ifdef HAVE_OLD_BPF 758 struct mbuf m0; 759 760 m0.m_next = m; 761 m0.m_len = 4; 762 m0.m_data = (char *)⁡ 763 764 BPF_MTAP(ifp, &m0); 765 #else 766 bpf_mtap2(ifp->if_bpf, &af, sizeof(ah), m); 767 #endif 768 } 769 770 /* 771 * Put the packet to the network layer input queue according to the 772 * specified address family. 773 * See net/if_gif.c for possible issues with packet processing 774 * reorder due to extra queueing. 775 */ 776 ifp->if_ipackets++; 777 ifp->if_ibytes += m->m_pkthdr.len; 778 netisr_dispatch(NETISR_IPV6, m); 779 } 780 781 /* ARGSUSED */ 782 static void 783 stf_rtrequest(cmd, rt, info) 784 int cmd; 785 struct rtentry *rt; 786 struct rt_addrinfo *info; 787 { 788 RT_LOCK_ASSERT(rt); 789 790 if (rt) 791 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 792 } 793 794 static int 795 stf_ioctl(ifp, cmd, data) 796 struct ifnet *ifp; 797 u_long cmd; 798 caddr_t data; 799 { 800 struct ifaddr *ifa; 801 struct ifreq *ifr; 802 struct sockaddr_in6 *sin6; 803 struct in_addr addr; 804 int error; 805 806 error = 0; 807 switch (cmd) { 808 case SIOCSIFADDR: 809 ifa = (struct ifaddr *)data; 810 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 811 error = EAFNOSUPPORT; 812 break; 813 } 814 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 815 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 816 error = EINVAL; 817 break; 818 } 819 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 820 if (isrfc1918addr(&addr)) { 821 error = EINVAL; 822 break; 823 } 824 825 ifa->ifa_rtrequest = stf_rtrequest; 826 ifp->if_flags |= IFF_UP; 827 break; 828 829 case SIOCADDMULTI: 830 case SIOCDELMULTI: 831 ifr = (struct ifreq *)data; 832 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 833 ; 834 else 835 error = EAFNOSUPPORT; 836 break; 837 838 default: 839 error = EINVAL; 840 break; 841 } 842 843 return error; 844 } 845