1 /* $FreeBSD: src/sys/net/if_stf.c,v 1.1.2.11 2003/01/23 21:06:44 sam Exp $ */ 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/protosw.h> 87 #include <sys/kernel.h> 88 #include <machine/cpu.h> 89 90 #include <sys/malloc.h> 91 92 #include <net/if.h> 93 #include <net/route.h> 94 #include <net/netisr.h> 95 #include <net/if_types.h> 96 #include <net/ifq_var.h> 97 #include <net/netisr2.h> 98 #include "if_stf.h" 99 100 #include <netinet/in.h> 101 #include <netinet/in_systm.h> 102 #include <netinet/ip.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 struct route *route_pcpu; 125 const struct encaptab *encap_cookie; 126 }; 127 128 static struct stf_softc *stf; 129 130 static MALLOC_DEFINE(M_STF, "stf", "6to4 Tunnel Interface"); 131 static int ip_stf_ttl = 40; 132 133 extern struct domain inetdomain; 134 struct protosw in_stf_protosw = 135 { 136 .pr_type = SOCK_RAW, 137 .pr_domain = &inetdomain, 138 .pr_protocol = IPPROTO_IPV6, 139 .pr_flags = PR_ATOMIC|PR_ADDR, 140 141 .pr_input = in_stf_input, 142 .pr_output = rip_output, 143 .pr_ctlinput = NULL, 144 .pr_ctloutput = rip_ctloutput, 145 146 .pr_usrreqs = &rip_usrreqs 147 }; 148 149 static int stfmodevent (module_t, int, void *); 150 static int stf_encapcheck (const struct mbuf *, int, int, void *); 151 static struct in6_ifaddr *stf_getsrcifa6 (struct ifnet *); 152 static int stf_output (struct ifnet *, struct mbuf *, struct sockaddr *, 153 struct rtentry *); 154 static int stf_checkaddr4 (struct stf_softc *, struct in_addr *, 155 struct ifnet *); 156 static int stf_checkaddr6 (struct stf_softc *, struct in6_addr *, 157 struct ifnet *); 158 static void stf_rtrequest (int, struct rtentry *); 159 static int stf_ioctl (struct ifnet *, u_long, caddr_t, struct ucred *); 160 161 static int 162 stfmodevent(module_t mod, int type, void *data) 163 { 164 struct stf_softc *sc; 165 int err, cpu; 166 const struct encaptab *p; 167 168 switch (type) { 169 case MOD_LOAD: 170 stf = kmalloc(sizeof(struct stf_softc), M_STF, 171 M_WAITOK | M_ZERO); 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 kprintf("%s: attach failed\n", if_name(&sc->sc_if)); 181 return (ENOMEM); 182 } 183 sc->encap_cookie = p; 184 sc->route_pcpu = kmalloc(netisr_ncpus * sizeof(struct route), 185 M_STF, M_WAITOK | M_ZERO); 186 187 sc->sc_if.if_mtu = IPV6_MMTU; 188 sc->sc_if.if_flags = 0; 189 sc->sc_if.if_ioctl = stf_ioctl; 190 sc->sc_if.if_output = stf_output; 191 sc->sc_if.if_type = IFT_STF; 192 #if 0 193 /* turn off ingress filter */ 194 sc->sc_if.if_flags |= IFF_LINK2; 195 #endif 196 ifq_set_maxlen(&sc->sc_if.if_snd, IFQ_MAXLEN); 197 if_attach(&sc->sc_if, NULL); 198 bpfattach(&sc->sc_if, DLT_NULL, sizeof(uint32_t)); 199 break; 200 case MOD_UNLOAD: 201 sc = stf; 202 bpfdetach(&sc->sc_if); 203 if_detach(&sc->sc_if); 204 err = encap_detach(sc->encap_cookie); 205 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 206 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 207 if (sc->route_pcpu[cpu].ro_rt != NULL) { 208 rtfree_async(sc->route_pcpu[cpu].ro_rt); 209 sc->route_pcpu[cpu].ro_rt = NULL; 210 } 211 } 212 kfree(sc->route_pcpu, M_STF); 213 kfree(sc, M_STF); 214 break; 215 } 216 217 return (0); 218 } 219 220 static moduledata_t stf_mod = { 221 "if_stf", 222 stfmodevent, 223 0 224 }; 225 226 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 227 228 static int 229 stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 230 { 231 struct ip ip; 232 struct in6_ifaddr *ia6; 233 struct stf_softc *sc; 234 struct in_addr a, b; 235 236 sc = (struct stf_softc *)arg; 237 if (sc == NULL) 238 return 0; 239 240 if ((sc->sc_if.if_flags & IFF_UP) == 0) 241 return 0; 242 243 /* IFF_LINK0 means "no decapsulation" */ 244 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 245 return 0; 246 247 if (proto != IPPROTO_IPV6) 248 return 0; 249 250 m_copydata(m, 0, sizeof(ip), &ip); 251 252 if (ip.ip_v != 4) 253 return 0; 254 255 ia6 = stf_getsrcifa6(&sc->sc_if); 256 if (ia6 == NULL) 257 return 0; 258 259 /* 260 * check if IPv4 dst matches the IPv4 address derived from the 261 * local 6to4 address. 262 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 263 */ 264 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 265 sizeof(ip.ip_dst)) != 0) 266 return 0; 267 268 /* 269 * check if IPv4 src matches the IPv4 address derived from the 270 * local 6to4 address masked by prefixmask. 271 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 272 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 273 */ 274 bzero(&a, sizeof(a)); 275 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 276 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 277 b = ip.ip_src; 278 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 279 if (a.s_addr != b.s_addr) 280 return 0; 281 282 /* stf interface makes single side match only */ 283 return 32; 284 } 285 286 static struct in6_ifaddr * 287 stf_getsrcifa6(struct ifnet *ifp) 288 { 289 struct ifaddr_container *ifac; 290 struct sockaddr_in6 *sin6; 291 struct in_addr in; 292 293 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) { 294 struct ifaddr *ia = ifac->ifa; 295 struct in_ifaddr_container *iac; 296 297 if (ia->ifa_addr == NULL) 298 continue; 299 if (ia->ifa_addr->sa_family != AF_INET6) 300 continue; 301 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 302 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 303 continue; 304 305 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 306 LIST_FOREACH(iac, INADDR_HASH(in.s_addr), ia_hash) { 307 if (iac->ia->ia_addr.sin_addr.s_addr == in.s_addr) 308 break; 309 } 310 if (iac == NULL) 311 continue; 312 313 return (struct in6_ifaddr *)ia; 314 } 315 316 return NULL; 317 } 318 319 static int 320 stf_output_serialized(struct ifnet *ifp, struct mbuf *m, 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 struct route *ro; 332 static const uint32_t af = AF_INET6; 333 334 ASSERT_NETISR_NCPUS(mycpuid); 335 336 sc = (struct stf_softc*)ifp; 337 dst6 = (struct sockaddr_in6 *)dst; 338 339 /* just in case */ 340 if ((ifp->if_flags & IFF_UP) == 0) { 341 m_freem(m); 342 return ENETDOWN; 343 } 344 345 /* 346 * If we don't have an ip4 address that match my inner ip6 address, 347 * we shouldn't generate output. Without this check, we'll end up 348 * using wrong IPv4 source. 349 */ 350 ia6 = stf_getsrcifa6(ifp); 351 if (ia6 == NULL) { 352 m_freem(m); 353 return ENETDOWN; 354 } 355 356 if (m->m_len < sizeof(*ip6)) { 357 m = m_pullup(m, sizeof(*ip6)); 358 if (!m) 359 return ENOBUFS; 360 } 361 ip6 = mtod(m, struct ip6_hdr *); 362 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 363 364 /* 365 * Pickup the right outer dst addr from the list of candidates. 366 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 367 */ 368 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 369 in4 = GET_V4(&ip6->ip6_dst); 370 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 371 in4 = GET_V4(&dst6->sin6_addr); 372 else { 373 m_freem(m); 374 return ENETUNREACH; 375 } 376 377 if (ifp->if_bpf) { 378 bpf_gettoken(); 379 if (ifp->if_bpf) 380 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af)); 381 bpf_reltoken(); 382 } 383 384 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 385 if (m && m->m_len < sizeof(struct ip)) 386 m = m_pullup(m, sizeof(struct ip)); 387 if (m == NULL) 388 return ENOBUFS; 389 ip = mtod(m, struct ip *); 390 391 bzero(ip, sizeof(*ip)); 392 393 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 394 &ip->ip_src, sizeof(ip->ip_src)); 395 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 396 ip->ip_p = IPPROTO_IPV6; 397 ip->ip_ttl = ip_stf_ttl; 398 ip->ip_len = htons(m->m_pkthdr.len); /* network order */ 399 if (ifp->if_flags & IFF_LINK1) 400 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 401 else 402 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 403 404 ro = &sc->route_pcpu[mycpuid]; 405 dst4 = (struct sockaddr_in *)&ro->ro_dst; 406 if (dst4->sin_family != AF_INET || 407 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 408 /* cache route doesn't match */ 409 dst4->sin_family = AF_INET; 410 dst4->sin_len = sizeof(struct sockaddr_in); 411 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 412 if (ro->ro_rt) { 413 RTFREE(ro->ro_rt); 414 ro->ro_rt = NULL; 415 } 416 } 417 if (ro->ro_rt != NULL && (ro->ro_rt->rt_flags & RTF_UP) == 0) { 418 RTFREE(ro->ro_rt); 419 ro->ro_rt = NULL; 420 } 421 422 if (ro->ro_rt == NULL) { 423 rtalloc(ro); 424 if (ro->ro_rt == NULL) { 425 m_freem(m); 426 return ENETUNREACH; 427 } 428 } 429 430 return ip_output(m, NULL, ro, IP_DEBUGROUTE, NULL, NULL); 431 } 432 433 static int 434 stf_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 435 struct rtentry *rt) 436 { 437 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 438 int error; 439 440 ifsq_serialize_hw(ifsq); 441 error = stf_output_serialized(ifp, m, dst, rt); 442 ifsq_deserialize_hw(ifsq); 443 444 return error; 445 } 446 447 /* 448 * Parameters: 449 * inifp: incoming interface 450 */ 451 static int 452 stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp) 453 { 454 struct in_ifaddr_container *iac; 455 456 /* 457 * reject packets with the following address: 458 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 459 */ 460 if (IN_MULTICAST(ntohl(in->s_addr))) 461 return -1; 462 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 463 case 0: case 127: case 255: 464 return -1; 465 } 466 467 /* 468 * reject packets with broadcast 469 */ 470 TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) { 471 struct in_ifaddr *ia4 = iac->ia; 472 473 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 474 continue; 475 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 476 return -1; 477 } 478 479 /* 480 * perform ingress filter 481 */ 482 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 483 struct sockaddr_in sin; 484 struct rtentry *rt; 485 486 bzero(&sin, sizeof(sin)); 487 sin.sin_family = AF_INET; 488 sin.sin_len = sizeof(struct sockaddr_in); 489 sin.sin_addr = *in; 490 rt = rtpurelookup((struct sockaddr *)&sin); 491 if (!rt || rt->rt_ifp != inifp) { 492 #if 0 493 log(LOG_WARNING, "%s: packet from 0x%x dropped " 494 "due to ingress filter\n", if_name(&sc->sc_if), 495 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 496 #endif 497 if (rt) 498 rtfree(rt); 499 return -1; 500 } 501 rtfree(rt); 502 } 503 504 return 0; 505 } 506 507 /* 508 * Parameters: 509 * inifp: incoming interface 510 */ 511 static int 512 stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp) 513 { 514 /* 515 * check 6to4 addresses 516 */ 517 if (IN6_IS_ADDR_6TO4(in6)) 518 return stf_checkaddr4(sc, GET_V4(in6), inifp); 519 520 /* 521 * reject anything that look suspicious. the test is implemented 522 * in ip6_input too, but we check here as well to 523 * (1) reject bad packets earlier, and 524 * (2) to be safe against future ip6_input change. 525 */ 526 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 527 return -1; 528 529 return 0; 530 } 531 532 int 533 in_stf_input(struct mbuf **mp, int *offp, int proto) 534 { 535 struct mbuf *m; 536 struct stf_softc *sc; 537 struct ip *ip; 538 struct ip6_hdr *ip6; 539 u_int8_t otos, itos; 540 struct ifnet *ifp; 541 int off; 542 static const uint32_t af = AF_INET6; 543 544 m = *mp; 545 off = *offp; 546 547 if (proto != IPPROTO_IPV6) { 548 m_freem(m); 549 return(IPPROTO_DONE); 550 } 551 552 ip = mtod(m, struct ip *); 553 554 sc = (struct stf_softc *)encap_getarg(m); 555 556 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 557 m_freem(m); 558 return(IPPROTO_DONE); 559 } 560 561 ifp = &sc->sc_if; 562 563 /* 564 * perform sanity check against outer src/dst. 565 * for source, perform ingress filter as well. 566 */ 567 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 568 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 569 m_freem(m); 570 return(IPPROTO_DONE); 571 } 572 573 otos = ip->ip_tos; 574 m_adj(m, off); 575 576 if (m->m_len < sizeof(*ip6)) { 577 m = m_pullup(m, sizeof(*ip6)); 578 if (!m) 579 return(IPPROTO_DONE); 580 } 581 ip6 = mtod(m, struct ip6_hdr *); 582 583 /* 584 * perform sanity check against inner src/dst. 585 * for source, perform ingress filter as well. 586 */ 587 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 588 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 589 m_freem(m); 590 return(IPPROTO_DONE); 591 } 592 593 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 594 if ((ifp->if_flags & IFF_LINK1) != 0) 595 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 596 else 597 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 598 ip6->ip6_flow &= ~htonl(0xff << 20); 599 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 600 601 m->m_pkthdr.rcvif = ifp; 602 603 if (ifp->if_bpf) { 604 bpf_gettoken(); 605 if (ifp->if_bpf) 606 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af)); 607 bpf_reltoken(); 608 } 609 610 /* 611 * Put the packet to the network layer input queue according to the 612 * specified address family. 613 * See net/if_gif.c for possible issues with packet processing 614 * reorder due to extra queueing. 615 */ 616 IFNET_STAT_INC(ifp, ipackets, 1); 617 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 618 m->m_flags &= ~M_HASH; 619 netisr_queue(NETISR_IPV6, m); 620 return(IPPROTO_DONE); 621 } 622 623 /* ARGSUSED */ 624 static void 625 stf_rtrequest(int cmd, struct rtentry *rt) 626 { 627 628 if (rt) 629 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 630 } 631 632 static int 633 stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 634 { 635 struct ifaddr *ifa; 636 struct ifreq *ifr; 637 struct sockaddr_in6 *sin6; 638 int error; 639 640 error = 0; 641 switch (cmd) { 642 case SIOCSIFADDR: 643 ifa = (struct ifaddr *)data; 644 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 645 error = EAFNOSUPPORT; 646 break; 647 } 648 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 649 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 650 ifa->ifa_rtrequest = stf_rtrequest; 651 ifp->if_flags |= IFF_UP; 652 } else 653 error = EINVAL; 654 break; 655 656 case SIOCADDMULTI: 657 case SIOCDELMULTI: 658 ifr = (struct ifreq *)data; 659 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 660 ; 661 else 662 error = EAFNOSUPPORT; 663 break; 664 665 default: 666 error = EINVAL; 667 break; 668 } 669 670 return error; 671 } 672