1 /* $FreeBSD$ */ 2 /* $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun 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/if_stf.h> 97 98 #include <netinet/in.h> 99 #include <netinet/in_systm.h> 100 #include <netinet/ip.h> 101 #include <netinet/ip_var.h> 102 #include <netinet/in_var.h> 103 104 #include <netinet/ip6.h> 105 #include <netinet6/ip6_var.h> 106 #include <netinet6/in6_var.h> 107 #include <netinet/ip_ecn.h> 108 109 #include <netinet/ip_encap.h> 110 111 #include <machine/stdarg.h> 112 113 #include <net/net_osdep.h> 114 115 #include <net/bpf.h> 116 117 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 118 #define GET_V4(x) ((struct in_addr *)(&(x)->s6_addr16[1])) 119 120 struct stf_softc { 121 struct ifnet sc_if; /* common area */ 122 union { 123 struct route __sc_ro4; 124 struct route_in6 __sc_ro6; /* just for safety */ 125 } __sc_ro46; 126 #define sc_ro __sc_ro46.__sc_ro4 127 const struct encaptab *encap_cookie; 128 }; 129 130 static struct stf_softc *stf; 131 132 static MALLOC_DEFINE(M_STF, "stf", "6to4 Tunnel Interface"); 133 static int ip_stf_ttl = 40; 134 135 extern struct domain inetdomain; 136 struct protosw in_stf_protosw = 137 { SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR, 138 in_stf_input, rip_output, 0, rip_ctloutput, 139 0, 140 0, 0, 0, 0, 141 &rip_usrreqs 142 }; 143 144 static int stfmodevent __P((module_t, int, void *)); 145 static int stf_encapcheck __P((const struct mbuf *, int, int, void *)); 146 static struct in6_ifaddr *stf_getsrcifa6 __P((struct ifnet *)); 147 static int stf_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 148 struct rtentry *)); 149 static int stf_checkaddr4 __P((struct stf_softc *, struct in_addr *, 150 struct ifnet *)); 151 static int stf_checkaddr6 __P((struct stf_softc *, struct in6_addr *, 152 struct ifnet *)); 153 static void stf_rtrequest __P((int, struct rtentry *, struct sockaddr *)); 154 static int stf_ioctl __P((struct ifnet *, u_long, caddr_t)); 155 156 static int 157 stfmodevent(mod, type, data) 158 module_t mod; 159 int type; 160 void *data; 161 { 162 struct stf_softc *sc; 163 int err; 164 const struct encaptab *p; 165 166 switch (type) { 167 case MOD_LOAD: 168 stf = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK); 169 bzero(stf, sizeof(struct stf_softc)); 170 sc = stf; 171 172 bzero(sc, sizeof(*sc)); 173 sc->sc_if.if_name = "stf"; 174 sc->sc_if.if_unit = 0; 175 176 p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, 177 &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 /* LINTED const cast */ 249 m_copydata((struct mbuf *)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 for (ia = TAILQ_FIRST(&ifp->if_addrlist); 295 ia; 296 ia = TAILQ_NEXT(ia, ifa_list)) 297 { 298 if (ia->ifa_addr == NULL) 299 continue; 300 if (ia->ifa_addr->sa_family != AF_INET6) 301 continue; 302 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 303 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 304 continue; 305 306 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 307 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 308 ia4; 309 ia4 = TAILQ_NEXT(ia4, ia_link)) 310 { 311 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 312 break; 313 } 314 if (ia4 == NULL) 315 continue; 316 317 return (struct in6_ifaddr *)ia; 318 } 319 320 return NULL; 321 } 322 323 static int 324 stf_output(ifp, m, dst, rt) 325 struct ifnet *ifp; 326 struct mbuf *m; 327 struct sockaddr *dst; 328 struct rtentry *rt; 329 { 330 struct stf_softc *sc; 331 struct sockaddr_in6 *dst6; 332 struct in_addr *in4; 333 struct sockaddr_in *dst4; 334 u_int8_t tos; 335 struct ip *ip; 336 struct ip6_hdr *ip6; 337 struct in6_ifaddr *ia6; 338 339 sc = (struct stf_softc*)ifp; 340 dst6 = (struct sockaddr_in6 *)dst; 341 342 /* just in case */ 343 if ((ifp->if_flags & IFF_UP) == 0) { 344 m_freem(m); 345 return ENETDOWN; 346 } 347 348 /* 349 * If we don't have an ip4 address that match my inner ip6 address, 350 * we shouldn't generate output. Without this check, we'll end up 351 * using wrong IPv4 source. 352 */ 353 ia6 = stf_getsrcifa6(ifp); 354 if (ia6 == NULL) { 355 m_freem(m); 356 return ENETDOWN; 357 } 358 359 if (m->m_len < sizeof(*ip6)) { 360 m = m_pullup(m, sizeof(*ip6)); 361 if (!m) 362 return ENOBUFS; 363 } 364 ip6 = mtod(m, struct ip6_hdr *); 365 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 366 367 /* 368 * Pickup the right outer dst addr from the list of candidates. 369 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 370 */ 371 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 372 in4 = GET_V4(&ip6->ip6_dst); 373 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 374 in4 = GET_V4(&dst6->sin6_addr); 375 else { 376 m_freem(m); 377 return ENETUNREACH; 378 } 379 380 #if NBPFILTER > 0 381 if (ifp->if_bpf) { 382 /* 383 * We need to prepend the address family as 384 * a four byte field. Cons up a dummy header 385 * to pacify bpf. This is safe because bpf 386 * will only read from the mbuf (i.e., it won't 387 * try to free it or keep a pointer a to it). 388 */ 389 struct mbuf m0; 390 u_int32_t af = AF_INET6; 391 392 m0.m_next = m; 393 m0.m_len = 4; 394 m0.m_data = (char *)⁡ 395 396 #ifdef HAVE_OLD_BPF 397 bpf_mtap(ifp, &m0); 398 #else 399 bpf_mtap(ifp->if_bpf, &m0); 400 #endif 401 } 402 #endif /*NBPFILTER > 0*/ 403 404 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 405 if (m && m->m_len < sizeof(struct ip)) 406 m = m_pullup(m, sizeof(struct ip)); 407 if (m == NULL) 408 return ENOBUFS; 409 ip = mtod(m, struct ip *); 410 411 bzero(ip, sizeof(*ip)); 412 413 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 414 &ip->ip_src, sizeof(ip->ip_src)); 415 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 416 ip->ip_p = IPPROTO_IPV6; 417 ip->ip_ttl = ip_stf_ttl; 418 ip->ip_len = m->m_pkthdr.len; /*host order*/ 419 if (ifp->if_flags & IFF_LINK1) 420 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 421 else 422 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 423 424 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 425 if (dst4->sin_family != AF_INET || 426 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 427 /* cache route doesn't match */ 428 dst4->sin_family = AF_INET; 429 dst4->sin_len = sizeof(struct sockaddr_in); 430 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 431 if (sc->sc_ro.ro_rt) { 432 RTFREE(sc->sc_ro.ro_rt); 433 sc->sc_ro.ro_rt = NULL; 434 } 435 } 436 437 if (sc->sc_ro.ro_rt == NULL) { 438 rtalloc(&sc->sc_ro); 439 if (sc->sc_ro.ro_rt == NULL) { 440 m_freem(m); 441 return ENETUNREACH; 442 } 443 } 444 445 return ip_output(m, NULL, &sc->sc_ro, 0, NULL); 446 } 447 448 static int 449 stf_checkaddr4(sc, in, inifp) 450 struct stf_softc *sc; 451 struct in_addr *in; 452 struct ifnet *inifp; /* incoming interface */ 453 { 454 struct in_ifaddr *ia4; 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 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 471 ia4; 472 ia4 = TAILQ_NEXT(ia4, ia_link)) 473 { 474 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 475 continue; 476 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 477 return -1; 478 } 479 480 /* 481 * perform ingress filter 482 */ 483 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 484 struct sockaddr_in sin; 485 struct rtentry *rt; 486 487 bzero(&sin, sizeof(sin)); 488 sin.sin_family = AF_INET; 489 sin.sin_len = sizeof(struct sockaddr_in); 490 sin.sin_addr = *in; 491 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 492 if (!rt || rt->rt_ifp != inifp) { 493 #if 0 494 log(LOG_WARNING, "%s: packet from 0x%x dropped " 495 "due to ingress filter\n", if_name(&sc->sc_if), 496 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 497 #endif 498 if (rt) 499 rtfree(rt); 500 return -1; 501 } 502 rtfree(rt); 503 } 504 505 return 0; 506 } 507 508 static int 509 stf_checkaddr6(sc, in6, inifp) 510 struct stf_softc *sc; 511 struct in6_addr *in6; 512 struct ifnet *inifp; /* incoming interface */ 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 void 533 in_stf_input(m, off) 534 struct mbuf *m; 535 int off; 536 { 537 int proto; 538 struct stf_softc *sc; 539 struct ip *ip; 540 struct ip6_hdr *ip6; 541 u_int8_t otos, itos; 542 int len, isr; 543 struct ifqueue *ifq = NULL; 544 struct ifnet *ifp; 545 546 proto = mtod(m, struct ip *)->ip_p; 547 548 if (proto != IPPROTO_IPV6) { 549 m_freem(m); 550 return; 551 } 552 553 ip = mtod(m, struct ip *); 554 555 sc = (struct stf_softc *)encap_getarg(m); 556 557 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 558 m_freem(m); 559 return; 560 } 561 562 ifp = &sc->sc_if; 563 564 /* 565 * perform sanity check against outer src/dst. 566 * for source, perform ingress filter as well. 567 */ 568 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 569 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 570 m_freem(m); 571 return; 572 } 573 574 otos = ip->ip_tos; 575 m_adj(m, off); 576 577 if (m->m_len < sizeof(*ip6)) { 578 m = m_pullup(m, sizeof(*ip6)); 579 if (!m) 580 return; 581 } 582 ip6 = mtod(m, struct ip6_hdr *); 583 584 /* 585 * perform sanity check against inner src/dst. 586 * for source, perform ingress filter as well. 587 */ 588 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 589 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 590 m_freem(m); 591 return; 592 } 593 594 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 595 if ((ifp->if_flags & IFF_LINK1) != 0) 596 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 597 else 598 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 599 ip6->ip6_flow &= ~htonl(0xff << 20); 600 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 601 602 m->m_pkthdr.rcvif = ifp; 603 604 if (ifp->if_bpf) { 605 /* 606 * We need to prepend the address family as 607 * a four byte field. Cons up a dummy header 608 * to pacify bpf. This is safe because bpf 609 * will only read from the mbuf (i.e., it won't 610 * try to free it or keep a pointer a to it). 611 */ 612 struct mbuf m0; 613 u_int32_t af = AF_INET6; 614 615 m0.m_next = m; 616 m0.m_len = 4; 617 m0.m_data = (char *)⁡ 618 619 #ifdef HAVE_OLD_BPF 620 bpf_mtap(ifp, &m0); 621 #else 622 bpf_mtap(ifp->if_bpf, &m0); 623 #endif 624 } 625 626 /* 627 * Put the packet to the network layer input queue according to the 628 * specified address family. 629 * See net/if_gif.c for possible issues with packet processing 630 * reorder due to extra queueing. 631 */ 632 ifq = &ip6intrq; 633 isr = NETISR_IPV6; 634 635 len = m->m_pkthdr.len; 636 if (! IF_HANDOFF(ifq, m, NULL)) 637 return; 638 schednetisr(isr); 639 ifp->if_ipackets++; 640 ifp->if_ibytes += len; 641 } 642 643 /* ARGSUSED */ 644 static void 645 stf_rtrequest(cmd, rt, sa) 646 int cmd; 647 struct rtentry *rt; 648 struct sockaddr *sa; 649 { 650 651 if (rt) 652 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 653 } 654 655 static int 656 stf_ioctl(ifp, cmd, data) 657 struct ifnet *ifp; 658 u_long cmd; 659 caddr_t data; 660 { 661 struct ifaddr *ifa; 662 struct ifreq *ifr; 663 struct sockaddr_in6 *sin6; 664 int error; 665 666 error = 0; 667 switch (cmd) { 668 case SIOCSIFADDR: 669 ifa = (struct ifaddr *)data; 670 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 671 error = EAFNOSUPPORT; 672 break; 673 } 674 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 675 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 676 ifa->ifa_rtrequest = stf_rtrequest; 677 ifp->if_flags |= IFF_UP; 678 } else 679 error = EINVAL; 680 break; 681 682 case SIOCADDMULTI: 683 case SIOCDELMULTI: 684 ifr = (struct ifreq *)data; 685 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 686 ; 687 else 688 error = EAFNOSUPPORT; 689 break; 690 691 default: 692 error = EINVAL; 693 break; 694 } 695 696 return error; 697 } 698