1 /* $FreeBSD: src/sys/net/if_stf.c,v 1.1.2.11 2003/01/23 21:06:44 sam Exp $ */ 2 /* $DragonFly: src/sys/net/stf/if_stf.c,v 1.10 2004/06/03 18:30:03 joerg Exp $ */ 3 /* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */ 4 5 /* 6 * Copyright (C) 2000 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * 6to4 interface, based on RFC3056. 36 * 37 * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting. 38 * There is no address mapping defined from IPv6 multicast address to IPv4 39 * address. Therefore, we do not have IFF_MULTICAST on the interface. 40 * 41 * Due to the lack of address mapping for link-local addresses, we cannot 42 * throw packets toward link-local addresses (fe80::x). Also, we cannot throw 43 * packets to link-local multicast addresses (ff02::x). 44 * 45 * Here are interesting symptoms due to the lack of link-local address: 46 * 47 * Unicast routing exchange: 48 * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9, 49 * and link-local addresses as nexthop. 50 * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address 51 * assigned to the link, and makes use of them. Also, HELLO packets use 52 * link-local multicast addresses (ff02::5 and ff02::6). 53 * - BGP4+: Maybe. You can only use global address as nexthop, and global 54 * address as TCP endpoint address. 55 * 56 * Multicast routing protocols: 57 * - PIM: Hello packet cannot be used to discover adjacent PIM routers. 58 * Adjacent PIM routers must be configured manually (is it really spec-wise 59 * correct thing to do?). 60 * 61 * ICMPv6: 62 * - Redirects cannot be used due to the lack of link-local address. 63 * 64 * stf interface does not have, and will not need, a link-local address. 65 * It seems to have no real benefit and does not help the above symptoms much. 66 * Even if we assign link-locals to interface, we cannot really 67 * use link-local unicast/multicast on top of 6to4 cloud (since there's no 68 * encapsulation defined for link-local address), and the above analysis does 69 * not change. RFC3056 does not mandate the assignment of link-local address 70 * either. 71 * 72 * 6to4 interface has security issues. Refer to 73 * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt 74 * for details. The code tries to filter out some of malicious packets. 75 * Note that there is no way to be 100% secure. 76 */ 77 78 #include "opt_inet.h" 79 #include "opt_inet6.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/mbuf.h> 86 #include <sys/errno.h> 87 #include <sys/protosw.h> 88 #include <sys/kernel.h> 89 #include <machine/cpu.h> 90 91 #include <sys/malloc.h> 92 93 #include <net/if.h> 94 #include <net/route.h> 95 #include <net/netisr.h> 96 #include <net/if_types.h> 97 #include "if_stf.h" 98 99 #include <netinet/in.h> 100 #include <netinet/in_systm.h> 101 #include <netinet/ip.h> 102 #include <netinet/ipprotosw.h> 103 #include <netinet/ip_var.h> 104 #include <netinet/in_var.h> 105 106 #include <netinet/ip6.h> 107 #include <netinet6/ip6_var.h> 108 #include <netinet6/in6_var.h> 109 #include <netinet/ip_ecn.h> 110 111 #include <netinet/ip_encap.h> 112 113 #include <machine/stdarg.h> 114 115 #include <net/net_osdep.h> 116 117 #include <net/bpf.h> 118 119 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 120 #define GET_V4(x) ((struct in_addr *)(&(x)->s6_addr16[1])) 121 122 struct stf_softc { 123 struct ifnet sc_if; /* common area */ 124 union { 125 struct route __sc_ro4; 126 struct route_in6 __sc_ro6; /* just for safety */ 127 } __sc_ro46; 128 #define sc_ro __sc_ro46.__sc_ro4 129 const struct encaptab *encap_cookie; 130 }; 131 132 static struct stf_softc *stf; 133 134 static MALLOC_DEFINE(M_STF, "stf", "6to4 Tunnel Interface"); 135 static int ip_stf_ttl = 40; 136 137 extern struct domain inetdomain; 138 struct ipprotosw in_stf_protosw = 139 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 140 in_stf_input, rip_output, 0, rip_ctloutput, 141 0, 142 0, 0, 0, 0, 143 &rip_usrreqs 144 }; 145 146 static int stfmodevent (module_t, int, void *); 147 static int stf_encapcheck (const struct mbuf *, int, int, void *); 148 static struct in6_ifaddr *stf_getsrcifa6 (struct ifnet *); 149 static int stf_output (struct ifnet *, struct mbuf *, struct sockaddr *, 150 struct rtentry *); 151 static int stf_checkaddr4 (struct stf_softc *, struct in_addr *, 152 struct ifnet *); 153 static int stf_checkaddr6 (struct stf_softc *, struct in6_addr *, 154 struct ifnet *); 155 static void stf_rtrequest (int, struct rtentry *, struct rt_addrinfo *); 156 static int stf_ioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 157 158 static int 159 stfmodevent(mod, type, data) 160 module_t mod; 161 int type; 162 void *data; 163 { 164 struct stf_softc *sc; 165 int err; 166 const struct encaptab *p; 167 168 switch (type) { 169 case MOD_LOAD: 170 stf = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK); 171 bzero(stf, sizeof(struct stf_softc)); 172 sc = stf; 173 174 bzero(sc, sizeof(*sc)); 175 if_initname(&(sc->sc_if), "stf", 0); 176 177 p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, 178 (void *)&in_stf_protosw, sc); 179 if (p == NULL) { 180 printf("%s: attach failed\n", if_name(&sc->sc_if)); 181 return (ENOMEM); 182 } 183 sc->encap_cookie = p; 184 185 sc->sc_if.if_mtu = IPV6_MMTU; 186 sc->sc_if.if_flags = 0; 187 sc->sc_if.if_ioctl = stf_ioctl; 188 sc->sc_if.if_output = stf_output; 189 sc->sc_if.if_type = IFT_STF; 190 #if 0 191 /* turn off ingress filter */ 192 sc->sc_if.if_flags |= IFF_LINK2; 193 #endif 194 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN; 195 if_attach(&sc->sc_if); 196 #ifdef HAVE_OLD_BPF 197 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 198 #else 199 bpfattach(&sc->sc_if.if_bpf, &sc->sc_if, DLT_NULL, sizeof(u_int)); 200 #endif 201 break; 202 case MOD_UNLOAD: 203 sc = stf; 204 bpfdetach(&sc->sc_if); 205 if_detach(&sc->sc_if); 206 err = encap_detach(sc->encap_cookie); 207 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 208 free(sc, M_STF); 209 break; 210 } 211 212 return (0); 213 } 214 215 static moduledata_t stf_mod = { 216 "if_stf", 217 stfmodevent, 218 0 219 }; 220 221 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 222 223 static int 224 stf_encapcheck(m, off, proto, arg) 225 const struct mbuf *m; 226 int off; 227 int proto; 228 void *arg; 229 { 230 struct ip ip; 231 struct in6_ifaddr *ia6; 232 struct stf_softc *sc; 233 struct in_addr a, b; 234 235 sc = (struct stf_softc *)arg; 236 if (sc == NULL) 237 return 0; 238 239 if ((sc->sc_if.if_flags & IFF_UP) == 0) 240 return 0; 241 242 /* IFF_LINK0 means "no decapsulation" */ 243 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 244 return 0; 245 246 if (proto != IPPROTO_IPV6) 247 return 0; 248 249 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 250 251 if (ip.ip_v != 4) 252 return 0; 253 254 ia6 = stf_getsrcifa6(&sc->sc_if); 255 if (ia6 == NULL) 256 return 0; 257 258 /* 259 * check if IPv4 dst matches the IPv4 address derived from the 260 * local 6to4 address. 261 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 262 */ 263 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 264 sizeof(ip.ip_dst)) != 0) 265 return 0; 266 267 /* 268 * check if IPv4 src matches the IPv4 address derived from the 269 * local 6to4 address masked by prefixmask. 270 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 271 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 272 */ 273 bzero(&a, sizeof(a)); 274 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 275 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 276 b = ip.ip_src; 277 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 278 if (a.s_addr != b.s_addr) 279 return 0; 280 281 /* stf interface makes single side match only */ 282 return 32; 283 } 284 285 static struct in6_ifaddr * 286 stf_getsrcifa6(ifp) 287 struct ifnet *ifp; 288 { 289 struct ifaddr *ia; 290 struct in_ifaddr *ia4; 291 struct sockaddr_in6 *sin6; 292 struct in_addr in; 293 294 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) { 295 if (ia->ifa_addr == NULL) 296 continue; 297 if (ia->ifa_addr->sa_family != AF_INET6) 298 continue; 299 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 300 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 301 continue; 302 303 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 304 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 305 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 306 break; 307 if (ia4 == NULL) 308 continue; 309 310 return (struct in6_ifaddr *)ia; 311 } 312 313 return NULL; 314 } 315 316 static int 317 stf_output(ifp, m, dst, rt) 318 struct ifnet *ifp; 319 struct mbuf *m; 320 struct sockaddr *dst; 321 struct rtentry *rt; 322 { 323 struct stf_softc *sc; 324 struct sockaddr_in6 *dst6; 325 struct in_addr *in4; 326 struct sockaddr_in *dst4; 327 u_int8_t tos; 328 struct ip *ip; 329 struct ip6_hdr *ip6; 330 struct in6_ifaddr *ia6; 331 332 sc = (struct stf_softc*)ifp; 333 dst6 = (struct sockaddr_in6 *)dst; 334 335 /* just in case */ 336 if ((ifp->if_flags & IFF_UP) == 0) { 337 m_freem(m); 338 return ENETDOWN; 339 } 340 341 /* 342 * If we don't have an ip4 address that match my inner ip6 address, 343 * we shouldn't generate output. Without this check, we'll end up 344 * using wrong IPv4 source. 345 */ 346 ia6 = stf_getsrcifa6(ifp); 347 if (ia6 == NULL) { 348 m_freem(m); 349 return ENETDOWN; 350 } 351 352 if (m->m_len < sizeof(*ip6)) { 353 m = m_pullup(m, sizeof(*ip6)); 354 if (!m) 355 return ENOBUFS; 356 } 357 ip6 = mtod(m, struct ip6_hdr *); 358 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 359 360 /* 361 * Pickup the right outer dst addr from the list of candidates. 362 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 363 */ 364 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 365 in4 = GET_V4(&ip6->ip6_dst); 366 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 367 in4 = GET_V4(&dst6->sin6_addr); 368 else { 369 m_freem(m); 370 return ENETUNREACH; 371 } 372 373 #if NBPFILTER > 0 374 if (ifp->if_bpf) { 375 /* 376 * We need to prepend the address family as 377 * a four byte field. Cons up a dummy header 378 * to pacify bpf. This is safe because bpf 379 * will only read from the mbuf (i.e., it won't 380 * try to free it or keep a pointer a to it). 381 */ 382 struct mbuf m0; 383 u_int32_t af = AF_INET6; 384 385 m0.m_next = m; 386 m0.m_len = 4; 387 m0.m_data = (char *)⁡ 388 389 #ifdef HAVE_OLD_BPF 390 bpf_mtap(ifp, &m0); 391 #else 392 bpf_mtap(ifp->if_bpf, &m0); 393 #endif 394 } 395 #endif /*NBPFILTER > 0*/ 396 397 M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT); 398 if (m && m->m_len < sizeof(struct ip)) 399 m = m_pullup(m, sizeof(struct ip)); 400 if (m == NULL) 401 return ENOBUFS; 402 ip = mtod(m, struct ip *); 403 404 bzero(ip, sizeof(*ip)); 405 406 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 407 &ip->ip_src, sizeof(ip->ip_src)); 408 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 409 ip->ip_p = IPPROTO_IPV6; 410 ip->ip_ttl = ip_stf_ttl; 411 ip->ip_len = m->m_pkthdr.len; /*host order*/ 412 if (ifp->if_flags & IFF_LINK1) 413 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 414 else 415 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 416 417 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 418 if (dst4->sin_family != AF_INET || 419 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 420 /* cache route doesn't match */ 421 dst4->sin_family = AF_INET; 422 dst4->sin_len = sizeof(struct sockaddr_in); 423 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 424 if (sc->sc_ro.ro_rt) { 425 RTFREE(sc->sc_ro.ro_rt); 426 sc->sc_ro.ro_rt = NULL; 427 } 428 } 429 430 if (sc->sc_ro.ro_rt == NULL) { 431 rtalloc(&sc->sc_ro); 432 if (sc->sc_ro.ro_rt == NULL) { 433 m_freem(m); 434 return ENETUNREACH; 435 } 436 } 437 438 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 439 } 440 441 static int 442 stf_checkaddr4(sc, in, inifp) 443 struct stf_softc *sc; 444 struct in_addr *in; 445 struct ifnet *inifp; /* incoming interface */ 446 { 447 struct in_ifaddr *ia4; 448 449 /* 450 * reject packets with the following address: 451 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 452 */ 453 if (IN_MULTICAST(ntohl(in->s_addr))) 454 return -1; 455 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 456 case 0: case 127: case 255: 457 return -1; 458 } 459 460 /* 461 * reject packets with broadcast 462 */ 463 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 464 ia4; 465 ia4 = TAILQ_NEXT(ia4, ia_link)) 466 { 467 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 468 continue; 469 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 470 return -1; 471 } 472 473 /* 474 * perform ingress filter 475 */ 476 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 477 struct sockaddr_in sin; 478 struct rtentry *rt; 479 480 bzero(&sin, sizeof(sin)); 481 sin.sin_family = AF_INET; 482 sin.sin_len = sizeof(struct sockaddr_in); 483 sin.sin_addr = *in; 484 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 485 if (!rt || rt->rt_ifp != inifp) { 486 #if 0 487 log(LOG_WARNING, "%s: packet from 0x%x dropped " 488 "due to ingress filter\n", if_name(&sc->sc_if), 489 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 490 #endif 491 if (rt) 492 rtfree(rt); 493 return -1; 494 } 495 rtfree(rt); 496 } 497 498 return 0; 499 } 500 501 static int 502 stf_checkaddr6(sc, in6, inifp) 503 struct stf_softc *sc; 504 struct in6_addr *in6; 505 struct ifnet *inifp; /* incoming interface */ 506 { 507 /* 508 * check 6to4 addresses 509 */ 510 if (IN6_IS_ADDR_6TO4(in6)) 511 return stf_checkaddr4(sc, GET_V4(in6), inifp); 512 513 /* 514 * reject anything that look suspicious. the test is implemented 515 * in ip6_input too, but we check here as well to 516 * (1) reject bad packets earlier, and 517 * (2) to be safe against future ip6_input change. 518 */ 519 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 520 return -1; 521 522 return 0; 523 } 524 525 void 526 in_stf_input(struct mbuf *m, ...) 527 { 528 struct stf_softc *sc; 529 struct ip *ip; 530 struct ip6_hdr *ip6; 531 u_int8_t otos, itos; 532 struct ifnet *ifp; 533 int off, proto; 534 __va_list ap; 535 536 __va_start(ap, m); 537 off = __va_arg(ap, int); 538 proto = __va_arg(ap, int); 539 __va_end(ap); 540 541 if (proto != IPPROTO_IPV6) { 542 m_freem(m); 543 return; 544 } 545 546 ip = mtod(m, struct ip *); 547 548 sc = (struct stf_softc *)encap_getarg(m); 549 550 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 551 m_freem(m); 552 return; 553 } 554 555 ifp = &sc->sc_if; 556 557 /* 558 * perform sanity check against outer src/dst. 559 * for source, perform ingress filter as well. 560 */ 561 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 562 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 563 m_freem(m); 564 return; 565 } 566 567 otos = ip->ip_tos; 568 m_adj(m, off); 569 570 if (m->m_len < sizeof(*ip6)) { 571 m = m_pullup(m, sizeof(*ip6)); 572 if (!m) 573 return; 574 } 575 ip6 = mtod(m, struct ip6_hdr *); 576 577 /* 578 * perform sanity check against inner src/dst. 579 * for source, perform ingress filter as well. 580 */ 581 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 582 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 583 m_freem(m); 584 return; 585 } 586 587 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 588 if ((ifp->if_flags & IFF_LINK1) != 0) 589 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 590 else 591 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 592 ip6->ip6_flow &= ~htonl(0xff << 20); 593 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 594 595 m->m_pkthdr.rcvif = ifp; 596 597 if (ifp->if_bpf) { 598 /* 599 * We need to prepend the address family as 600 * a four byte field. Cons up a dummy header 601 * to pacify bpf. This is safe because bpf 602 * will only read from the mbuf (i.e., it won't 603 * try to free it or keep a pointer a to it). 604 */ 605 struct mbuf m0; 606 u_int32_t af = AF_INET6; 607 608 m0.m_next = m; 609 m0.m_len = 4; 610 m0.m_data = (char *)⁡ 611 612 #ifdef HAVE_OLD_BPF 613 bpf_mtap(ifp, &m0); 614 #else 615 bpf_mtap(ifp->if_bpf, &m0); 616 #endif 617 } 618 619 /* 620 * Put the packet to the network layer input queue according to the 621 * specified address family. 622 * See net/if_gif.c for possible issues with packet processing 623 * reorder due to extra queueing. 624 */ 625 ifp->if_ipackets++; 626 ifp->if_ibytes += m->m_pkthdr.len; 627 netisr_dispatch(NETISR_IPV6, m); 628 } 629 630 /* ARGSUSED */ 631 static void 632 stf_rtrequest(cmd, rt, info) 633 int cmd; 634 struct rtentry *rt; 635 struct rt_addrinfo *info; 636 { 637 638 if (rt) 639 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 640 } 641 642 static int 643 stf_ioctl(ifp, cmd, data, cr) 644 struct ifnet *ifp; 645 u_long cmd; 646 caddr_t data; 647 struct ucred *cr; 648 { 649 struct ifaddr *ifa; 650 struct ifreq *ifr; 651 struct sockaddr_in6 *sin6; 652 int error; 653 654 error = 0; 655 switch (cmd) { 656 case SIOCSIFADDR: 657 ifa = (struct ifaddr *)data; 658 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 659 error = EAFNOSUPPORT; 660 break; 661 } 662 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 663 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 664 ifa->ifa_rtrequest = stf_rtrequest; 665 ifp->if_flags |= IFF_UP; 666 } else 667 error = EINVAL; 668 break; 669 670 case SIOCADDMULTI: 671 case SIOCDELMULTI: 672 ifr = (struct ifreq *)data; 673 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 674 ; 675 else 676 error = EAFNOSUPPORT; 677 break; 678 679 default: 680 error = EINVAL; 681 break; 682 } 683 684 return error; 685 } 686