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 1.13 2005/01/07 05:42:59 hsu 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/ip_var.h> 103 #include <netinet/in_var.h> 104 105 #include <netinet/ip6.h> 106 #include <netinet6/ip6_var.h> 107 #include <netinet6/in6_var.h> 108 #include <netinet/ip_ecn.h> 109 110 #include <netinet/ip_encap.h> 111 112 #include <machine/stdarg.h> 113 114 #include <net/net_osdep.h> 115 116 #include <net/bpf.h> 117 118 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 119 #define GET_V4(x) ((struct in_addr *)(&(x)->s6_addr16[1])) 120 121 struct stf_softc { 122 struct ifnet sc_if; /* common area */ 123 union { 124 struct route __sc_ro4; 125 struct route_in6 __sc_ro6; /* just for safety */ 126 } __sc_ro46; 127 #define sc_ro __sc_ro46.__sc_ro4 128 const struct encaptab *encap_cookie; 129 }; 130 131 static struct stf_softc *stf; 132 133 static MALLOC_DEFINE(M_STF, "stf", "6to4 Tunnel Interface"); 134 static int ip_stf_ttl = 40; 135 136 extern struct domain inetdomain; 137 struct protosw in_stf_protosw = 138 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 139 in_stf_input, rip_output, 0, rip_ctloutput, 140 0, 141 0, 0, 0, 0, 142 &rip_usrreqs 143 }; 144 145 static int stfmodevent (module_t, int, void *); 146 static int stf_encapcheck (const struct mbuf *, int, int, void *); 147 static struct in6_ifaddr *stf_getsrcifa6 (struct ifnet *); 148 static int stf_output (struct ifnet *, struct mbuf *, struct sockaddr *, 149 struct rtentry *); 150 static int stf_checkaddr4 (struct stf_softc *, struct in_addr *, 151 struct ifnet *); 152 static int stf_checkaddr6 (struct stf_softc *, struct in6_addr *, 153 struct ifnet *); 154 static void stf_rtrequest (int, struct rtentry *, struct rt_addrinfo *); 155 static int stf_ioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 156 157 static int 158 stfmodevent(mod, type, data) 159 module_t mod; 160 int type; 161 void *data; 162 { 163 struct stf_softc *sc; 164 int err; 165 const struct encaptab *p; 166 167 switch (type) { 168 case MOD_LOAD: 169 stf = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK); 170 bzero(stf, sizeof(struct stf_softc)); 171 sc = stf; 172 173 bzero(sc, sizeof(*sc)); 174 if_initname(&(sc->sc_if), "stf", 0); 175 176 p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, 177 (void *)&in_stf_protosw, sc); 178 if (p == NULL) { 179 printf("%s: attach failed\n", if_name(&sc->sc_if)); 180 return (ENOMEM); 181 } 182 sc->encap_cookie = p; 183 184 sc->sc_if.if_mtu = IPV6_MMTU; 185 sc->sc_if.if_flags = 0; 186 sc->sc_if.if_ioctl = stf_ioctl; 187 sc->sc_if.if_output = stf_output; 188 sc->sc_if.if_type = IFT_STF; 189 #if 0 190 /* turn off ingress filter */ 191 sc->sc_if.if_flags |= IFF_LINK2; 192 #endif 193 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN; 194 if_attach(&sc->sc_if); 195 #ifdef HAVE_OLD_BPF 196 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 197 #else 198 bpfattach(&sc->sc_if.if_bpf, &sc->sc_if, DLT_NULL, sizeof(u_int)); 199 #endif 200 break; 201 case MOD_UNLOAD: 202 sc = stf; 203 bpfdetach(&sc->sc_if); 204 if_detach(&sc->sc_if); 205 err = encap_detach(sc->encap_cookie); 206 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 207 free(sc, M_STF); 208 break; 209 } 210 211 return (0); 212 } 213 214 static moduledata_t stf_mod = { 215 "if_stf", 216 stfmodevent, 217 0 218 }; 219 220 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 221 222 static int 223 stf_encapcheck(m, off, proto, arg) 224 const struct mbuf *m; 225 int off; 226 int proto; 227 void *arg; 228 { 229 struct ip ip; 230 struct in6_ifaddr *ia6; 231 struct stf_softc *sc; 232 struct in_addr a, b; 233 234 sc = (struct stf_softc *)arg; 235 if (sc == NULL) 236 return 0; 237 238 if ((sc->sc_if.if_flags & IFF_UP) == 0) 239 return 0; 240 241 /* IFF_LINK0 means "no decapsulation" */ 242 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 243 return 0; 244 245 if (proto != IPPROTO_IPV6) 246 return 0; 247 248 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 249 250 if (ip.ip_v != 4) 251 return 0; 252 253 ia6 = stf_getsrcifa6(&sc->sc_if); 254 if (ia6 == NULL) 255 return 0; 256 257 /* 258 * check if IPv4 dst matches the IPv4 address derived from the 259 * local 6to4 address. 260 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 261 */ 262 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 263 sizeof(ip.ip_dst)) != 0) 264 return 0; 265 266 /* 267 * check if IPv4 src matches the IPv4 address derived from the 268 * local 6to4 address masked by prefixmask. 269 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 270 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 271 */ 272 bzero(&a, sizeof(a)); 273 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 274 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 275 b = ip.ip_src; 276 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 277 if (a.s_addr != b.s_addr) 278 return 0; 279 280 /* stf interface makes single side match only */ 281 return 32; 282 } 283 284 static struct in6_ifaddr * 285 stf_getsrcifa6(ifp) 286 struct ifnet *ifp; 287 { 288 struct ifaddr *ia; 289 struct in_ifaddr *ia4; 290 struct sockaddr_in6 *sin6; 291 struct in_addr in; 292 293 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) { 294 if (ia->ifa_addr == NULL) 295 continue; 296 if (ia->ifa_addr->sa_family != AF_INET6) 297 continue; 298 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 299 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 300 continue; 301 302 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 303 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 304 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 305 break; 306 if (ia4 == NULL) 307 continue; 308 309 return (struct in6_ifaddr *)ia; 310 } 311 312 return NULL; 313 } 314 315 static int 316 stf_output(ifp, m, dst, rt) 317 struct ifnet *ifp; 318 struct mbuf *m; 319 struct sockaddr *dst; 320 struct rtentry *rt; 321 { 322 struct stf_softc *sc; 323 struct sockaddr_in6 *dst6; 324 struct in_addr *in4; 325 struct sockaddr_in *dst4; 326 u_int8_t tos; 327 struct ip *ip; 328 struct ip6_hdr *ip6; 329 struct in6_ifaddr *ia6; 330 331 sc = (struct stf_softc*)ifp; 332 dst6 = (struct sockaddr_in6 *)dst; 333 334 /* just in case */ 335 if ((ifp->if_flags & IFF_UP) == 0) { 336 m_freem(m); 337 return ENETDOWN; 338 } 339 340 /* 341 * If we don't have an ip4 address that match my inner ip6 address, 342 * we shouldn't generate output. Without this check, we'll end up 343 * using wrong IPv4 source. 344 */ 345 ia6 = stf_getsrcifa6(ifp); 346 if (ia6 == NULL) { 347 m_freem(m); 348 return ENETDOWN; 349 } 350 351 if (m->m_len < sizeof(*ip6)) { 352 m = m_pullup(m, sizeof(*ip6)); 353 if (!m) 354 return ENOBUFS; 355 } 356 ip6 = mtod(m, struct ip6_hdr *); 357 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 358 359 /* 360 * Pickup the right outer dst addr from the list of candidates. 361 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 362 */ 363 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 364 in4 = GET_V4(&ip6->ip6_dst); 365 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 366 in4 = GET_V4(&dst6->sin6_addr); 367 else { 368 m_freem(m); 369 return ENETUNREACH; 370 } 371 372 #if NBPFILTER > 0 373 if (ifp->if_bpf) { 374 /* 375 * We need to prepend the address family as 376 * a four byte field. Cons up a dummy header 377 * to pacify bpf. This is safe because bpf 378 * will only read from the mbuf (i.e., it won't 379 * try to free it or keep a pointer a to it). 380 */ 381 struct mbuf m0; 382 u_int32_t af = AF_INET6; 383 384 m0.m_next = m; 385 m0.m_len = 4; 386 m0.m_data = (char *)⁡ 387 388 #ifdef HAVE_OLD_BPF 389 bpf_mtap(ifp, &m0); 390 #else 391 bpf_mtap(ifp->if_bpf, &m0); 392 #endif 393 } 394 #endif /*NBPFILTER > 0*/ 395 396 M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT); 397 if (m && m->m_len < sizeof(struct ip)) 398 m = m_pullup(m, sizeof(struct ip)); 399 if (m == NULL) 400 return ENOBUFS; 401 ip = mtod(m, struct ip *); 402 403 bzero(ip, sizeof(*ip)); 404 405 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 406 &ip->ip_src, sizeof(ip->ip_src)); 407 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 408 ip->ip_p = IPPROTO_IPV6; 409 ip->ip_ttl = ip_stf_ttl; 410 ip->ip_len = m->m_pkthdr.len; /*host order*/ 411 if (ifp->if_flags & IFF_LINK1) 412 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 413 else 414 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 415 416 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 417 if (dst4->sin_family != AF_INET || 418 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 419 /* cache route doesn't match */ 420 dst4->sin_family = AF_INET; 421 dst4->sin_len = sizeof(struct sockaddr_in); 422 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 423 if (sc->sc_ro.ro_rt) { 424 RTFREE(sc->sc_ro.ro_rt); 425 sc->sc_ro.ro_rt = NULL; 426 } 427 } 428 429 if (sc->sc_ro.ro_rt == NULL) { 430 rtalloc(&sc->sc_ro); 431 if (sc->sc_ro.ro_rt == NULL) { 432 m_freem(m); 433 return ENETUNREACH; 434 } 435 } 436 437 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 438 } 439 440 static int 441 stf_checkaddr4(sc, in, inifp) 442 struct stf_softc *sc; 443 struct in_addr *in; 444 struct ifnet *inifp; /* incoming interface */ 445 { 446 struct in_ifaddr *ia4; 447 448 /* 449 * reject packets with the following address: 450 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 451 */ 452 if (IN_MULTICAST(ntohl(in->s_addr))) 453 return -1; 454 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 455 case 0: case 127: case 255: 456 return -1; 457 } 458 459 /* 460 * reject packets with broadcast 461 */ 462 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 463 ia4; 464 ia4 = TAILQ_NEXT(ia4, ia_link)) 465 { 466 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 467 continue; 468 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 469 return -1; 470 } 471 472 /* 473 * perform ingress filter 474 */ 475 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 476 struct sockaddr_in sin; 477 struct rtentry *rt; 478 479 bzero(&sin, sizeof(sin)); 480 sin.sin_family = AF_INET; 481 sin.sin_len = sizeof(struct sockaddr_in); 482 sin.sin_addr = *in; 483 rt = rtpurelookup((struct sockaddr *)&sin); 484 if (!rt || rt->rt_ifp != inifp) { 485 #if 0 486 log(LOG_WARNING, "%s: packet from 0x%x dropped " 487 "due to ingress filter\n", if_name(&sc->sc_if), 488 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 489 #endif 490 if (rt) 491 rtfree(rt); 492 return -1; 493 } 494 rtfree(rt); 495 } 496 497 return 0; 498 } 499 500 static int 501 stf_checkaddr6(sc, in6, inifp) 502 struct stf_softc *sc; 503 struct in6_addr *in6; 504 struct ifnet *inifp; /* incoming interface */ 505 { 506 /* 507 * check 6to4 addresses 508 */ 509 if (IN6_IS_ADDR_6TO4(in6)) 510 return stf_checkaddr4(sc, GET_V4(in6), inifp); 511 512 /* 513 * reject anything that look suspicious. the test is implemented 514 * in ip6_input too, but we check here as well to 515 * (1) reject bad packets earlier, and 516 * (2) to be safe against future ip6_input change. 517 */ 518 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 519 return -1; 520 521 return 0; 522 } 523 524 void 525 in_stf_input(struct mbuf *m, ...) 526 { 527 struct stf_softc *sc; 528 struct ip *ip; 529 struct ip6_hdr *ip6; 530 u_int8_t otos, itos; 531 struct ifnet *ifp; 532 int off, proto; 533 __va_list ap; 534 535 __va_start(ap, m); 536 off = __va_arg(ap, int); 537 proto = __va_arg(ap, int); 538 __va_end(ap); 539 540 if (proto != IPPROTO_IPV6) { 541 m_freem(m); 542 return; 543 } 544 545 ip = mtod(m, struct ip *); 546 547 sc = (struct stf_softc *)encap_getarg(m); 548 549 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 550 m_freem(m); 551 return; 552 } 553 554 ifp = &sc->sc_if; 555 556 /* 557 * perform sanity check against outer src/dst. 558 * for source, perform ingress filter as well. 559 */ 560 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 561 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 562 m_freem(m); 563 return; 564 } 565 566 otos = ip->ip_tos; 567 m_adj(m, off); 568 569 if (m->m_len < sizeof(*ip6)) { 570 m = m_pullup(m, sizeof(*ip6)); 571 if (!m) 572 return; 573 } 574 ip6 = mtod(m, struct ip6_hdr *); 575 576 /* 577 * perform sanity check against inner src/dst. 578 * for source, perform ingress filter as well. 579 */ 580 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 581 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 582 m_freem(m); 583 return; 584 } 585 586 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 587 if ((ifp->if_flags & IFF_LINK1) != 0) 588 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 589 else 590 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 591 ip6->ip6_flow &= ~htonl(0xff << 20); 592 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 593 594 m->m_pkthdr.rcvif = ifp; 595 596 if (ifp->if_bpf) { 597 /* 598 * We need to prepend the address family as 599 * a four byte field. Cons up a dummy header 600 * to pacify bpf. This is safe because bpf 601 * will only read from the mbuf (i.e., it won't 602 * try to free it or keep a pointer a to it). 603 */ 604 struct mbuf m0; 605 u_int32_t af = AF_INET6; 606 607 m0.m_next = m; 608 m0.m_len = 4; 609 m0.m_data = (char *)⁡ 610 611 #ifdef HAVE_OLD_BPF 612 bpf_mtap(ifp, &m0); 613 #else 614 bpf_mtap(ifp->if_bpf, &m0); 615 #endif 616 } 617 618 /* 619 * Put the packet to the network layer input queue according to the 620 * specified address family. 621 * See net/if_gif.c for possible issues with packet processing 622 * reorder due to extra queueing. 623 */ 624 ifp->if_ipackets++; 625 ifp->if_ibytes += m->m_pkthdr.len; 626 netisr_dispatch(NETISR_IPV6, m); 627 } 628 629 /* ARGSUSED */ 630 static void 631 stf_rtrequest(cmd, rt, info) 632 int cmd; 633 struct rtentry *rt; 634 struct rt_addrinfo *info; 635 { 636 637 if (rt) 638 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 639 } 640 641 static int 642 stf_ioctl(ifp, cmd, data, cr) 643 struct ifnet *ifp; 644 u_long cmd; 645 caddr_t data; 646 struct ucred *cr; 647 { 648 struct ifaddr *ifa; 649 struct ifreq *ifr; 650 struct sockaddr_in6 *sin6; 651 int error; 652 653 error = 0; 654 switch (cmd) { 655 case SIOCSIFADDR: 656 ifa = (struct ifaddr *)data; 657 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 658 error = EAFNOSUPPORT; 659 break; 660 } 661 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 662 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 663 ifa->ifa_rtrequest = stf_rtrequest; 664 ifp->if_flags |= IFF_UP; 665 } else 666 error = EINVAL; 667 break; 668 669 case SIOCADDMULTI: 670 case SIOCDELMULTI: 671 ifr = (struct ifreq *)data; 672 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 673 ; 674 else 675 error = EAFNOSUPPORT; 676 break; 677 678 default: 679 error = EINVAL; 680 break; 681 } 682 683 return error; 684 } 685