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 default: 305 return (EOPNOTSUPP); 306 } 307 308 return (0); 309 } 310 311 static moduledata_t stf_mod = { 312 "if_stf", 313 stfmodevent, 314 0 315 }; 316 317 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 318 319 static int 320 stf_encapcheck(m, off, proto, arg) 321 const struct mbuf *m; 322 int off; 323 int proto; 324 void *arg; 325 { 326 struct ip ip; 327 struct in6_ifaddr *ia6; 328 struct stf_softc *sc; 329 struct in_addr a, b, mask; 330 331 sc = (struct stf_softc *)arg; 332 if (sc == NULL) 333 return 0; 334 335 if ((sc->sc_if.if_flags & IFF_UP) == 0) 336 return 0; 337 338 /* IFF_LINK0 means "no decapsulation" */ 339 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 340 return 0; 341 342 if (proto != IPPROTO_IPV6) 343 return 0; 344 345 /* LINTED const cast */ 346 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 347 348 if (ip.ip_v != 4) 349 return 0; 350 351 ia6 = stf_getsrcifa6(&sc->sc_if); 352 if (ia6 == NULL) 353 return 0; 354 355 /* 356 * check if IPv4 dst matches the IPv4 address derived from the 357 * local 6to4 address. 358 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 359 */ 360 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 361 sizeof(ip.ip_dst)) != 0) 362 return 0; 363 364 /* 365 * check if IPv4 src matches the IPv4 address derived from the 366 * local 6to4 address masked by prefixmask. 367 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 368 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 369 */ 370 bzero(&a, sizeof(a)); 371 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 372 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 373 a.s_addr &= mask.s_addr; 374 b = ip.ip_src; 375 b.s_addr &= mask.s_addr; 376 if (a.s_addr != b.s_addr) 377 return 0; 378 379 /* stf interface makes single side match only */ 380 return 32; 381 } 382 383 static struct in6_ifaddr * 384 stf_getsrcifa6(ifp) 385 struct ifnet *ifp; 386 { 387 struct ifaddr *ia; 388 struct in_ifaddr *ia4; 389 struct sockaddr_in6 *sin6; 390 struct in_addr in; 391 392 for (ia = TAILQ_FIRST(&ifp->if_addrlist); 393 ia; 394 ia = TAILQ_NEXT(ia, ifa_list)) 395 { 396 if (ia->ifa_addr == NULL) 397 continue; 398 if (ia->ifa_addr->sa_family != AF_INET6) 399 continue; 400 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 401 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 402 continue; 403 404 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 405 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 406 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 407 break; 408 if (ia4 == NULL) 409 continue; 410 411 return (struct in6_ifaddr *)ia; 412 } 413 414 return NULL; 415 } 416 417 static int 418 stf_output(ifp, m, dst, rt) 419 struct ifnet *ifp; 420 struct mbuf *m; 421 struct sockaddr *dst; 422 struct rtentry *rt; 423 { 424 struct stf_softc *sc; 425 struct sockaddr_in6 *dst6; 426 struct in_addr in4; 427 caddr_t ptr; 428 struct sockaddr_in *dst4; 429 u_int8_t tos; 430 struct ip *ip; 431 struct ip6_hdr *ip6; 432 struct in6_ifaddr *ia6; 433 #ifdef MAC 434 int error; 435 436 error = mac_check_ifnet_transmit(ifp, m); 437 if (error) { 438 m_freem(m); 439 return (error); 440 } 441 #endif 442 443 sc = (struct stf_softc*)ifp; 444 dst6 = (struct sockaddr_in6 *)dst; 445 446 /* just in case */ 447 if ((ifp->if_flags & IFF_UP) == 0) { 448 m_freem(m); 449 ifp->if_oerrors++; 450 return ENETDOWN; 451 } 452 453 /* 454 * If we don't have an ip4 address that match my inner ip6 address, 455 * we shouldn't generate output. Without this check, we'll end up 456 * using wrong IPv4 source. 457 */ 458 ia6 = stf_getsrcifa6(ifp); 459 if (ia6 == NULL) { 460 m_freem(m); 461 ifp->if_oerrors++; 462 return ENETDOWN; 463 } 464 465 if (m->m_len < sizeof(*ip6)) { 466 m = m_pullup(m, sizeof(*ip6)); 467 if (!m) { 468 ifp->if_oerrors++; 469 return ENOBUFS; 470 } 471 } 472 ip6 = mtod(m, struct ip6_hdr *); 473 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 474 475 /* 476 * Pickup the right outer dst addr from the list of candidates. 477 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 478 */ 479 ptr = NULL; 480 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 481 ptr = GET_V4(&ip6->ip6_dst); 482 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 483 ptr = GET_V4(&dst6->sin6_addr); 484 else { 485 m_freem(m); 486 ifp->if_oerrors++; 487 return ENETUNREACH; 488 } 489 bcopy(ptr, &in4, sizeof(in4)); 490 491 if (ifp->if_bpf) { 492 /* 493 * We need to prepend the address family as 494 * a four byte field. Cons up a dummy header 495 * to pacify bpf. This is safe because bpf 496 * will only read from the mbuf (i.e., it won't 497 * try to free it or keep a pointer a to it). 498 */ 499 u_int32_t af = AF_INET6; 500 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 501 } 502 503 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 504 if (m && m->m_len < sizeof(struct ip)) 505 m = m_pullup(m, sizeof(struct ip)); 506 if (m == NULL) { 507 ifp->if_oerrors++; 508 return ENOBUFS; 509 } 510 ip = mtod(m, struct ip *); 511 512 bzero(ip, sizeof(*ip)); 513 514 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 515 &ip->ip_src, sizeof(ip->ip_src)); 516 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 517 ip->ip_p = IPPROTO_IPV6; 518 ip->ip_ttl = ip_stf_ttl; 519 ip->ip_len = m->m_pkthdr.len; /*host order*/ 520 if (ifp->if_flags & IFF_LINK1) 521 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 522 else 523 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 524 525 /* 526 * XXXRW: Locking of sc_ro required. 527 */ 528 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 529 if (dst4->sin_family != AF_INET || 530 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 531 /* cache route doesn't match */ 532 dst4->sin_family = AF_INET; 533 dst4->sin_len = sizeof(struct sockaddr_in); 534 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 535 if (sc->sc_ro.ro_rt) { 536 RTFREE(sc->sc_ro.ro_rt); 537 sc->sc_ro.ro_rt = NULL; 538 } 539 } 540 541 if (sc->sc_ro.ro_rt == NULL) { 542 rtalloc(&sc->sc_ro); 543 if (sc->sc_ro.ro_rt == NULL) { 544 m_freem(m); 545 ifp->if_oerrors++; 546 return ENETUNREACH; 547 } 548 } 549 550 ifp->if_opackets++; 551 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 552 } 553 554 static int 555 isrfc1918addr(in) 556 struct in_addr *in; 557 { 558 /* 559 * returns 1 if private address range: 560 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 561 */ 562 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 563 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 564 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 565 return 1; 566 567 return 0; 568 } 569 570 static int 571 stf_checkaddr4(sc, in, inifp) 572 struct stf_softc *sc; 573 struct in_addr *in; 574 struct ifnet *inifp; /* incoming interface */ 575 { 576 struct in_ifaddr *ia4; 577 578 /* 579 * reject packets with the following address: 580 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 581 */ 582 if (IN_MULTICAST(ntohl(in->s_addr))) 583 return -1; 584 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 585 case 0: case 127: case 255: 586 return -1; 587 } 588 589 /* 590 * reject packets with private address range. 591 * (requirement from RFC3056 section 2 1st paragraph) 592 */ 593 if (isrfc1918addr(in)) 594 return -1; 595 596 /* 597 * reject packets with broadcast 598 */ 599 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 600 ia4; 601 ia4 = TAILQ_NEXT(ia4, ia_link)) 602 { 603 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 604 continue; 605 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 606 return -1; 607 } 608 609 /* 610 * perform ingress filter 611 */ 612 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 613 struct sockaddr_in sin; 614 struct rtentry *rt; 615 616 bzero(&sin, sizeof(sin)); 617 sin.sin_family = AF_INET; 618 sin.sin_len = sizeof(struct sockaddr_in); 619 sin.sin_addr = *in; 620 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 621 if (!rt || rt->rt_ifp != inifp) { 622 #if 0 623 log(LOG_WARNING, "%s: packet from 0x%x dropped " 624 "due to ingress filter\n", if_name(&sc->sc_if), 625 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 626 #endif 627 if (rt) 628 rtfree(rt); 629 return -1; 630 } 631 rtfree(rt); 632 } 633 634 return 0; 635 } 636 637 static int 638 stf_checkaddr6(sc, in6, inifp) 639 struct stf_softc *sc; 640 struct in6_addr *in6; 641 struct ifnet *inifp; /* incoming interface */ 642 { 643 /* 644 * check 6to4 addresses 645 */ 646 if (IN6_IS_ADDR_6TO4(in6)) { 647 struct in_addr in4; 648 bcopy(GET_V4(in6), &in4, sizeof(in4)); 649 return stf_checkaddr4(sc, &in4, inifp); 650 } 651 652 /* 653 * reject anything that look suspicious. the test is implemented 654 * in ip6_input too, but we check here as well to 655 * (1) reject bad packets earlier, and 656 * (2) to be safe against future ip6_input change. 657 */ 658 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 659 return -1; 660 661 return 0; 662 } 663 664 void 665 in_stf_input(m, off) 666 struct mbuf *m; 667 int off; 668 { 669 int proto; 670 struct stf_softc *sc; 671 struct ip *ip; 672 struct ip6_hdr *ip6; 673 u_int8_t otos, itos; 674 struct ifnet *ifp; 675 676 proto = mtod(m, struct ip *)->ip_p; 677 678 if (proto != IPPROTO_IPV6) { 679 m_freem(m); 680 return; 681 } 682 683 ip = mtod(m, struct ip *); 684 685 sc = (struct stf_softc *)encap_getarg(m); 686 687 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 688 m_freem(m); 689 return; 690 } 691 692 ifp = &sc->sc_if; 693 694 #ifdef MAC 695 mac_create_mbuf_from_ifnet(ifp, m); 696 #endif 697 698 /* 699 * perform sanity check against outer src/dst. 700 * for source, perform ingress filter as well. 701 */ 702 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 703 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 704 m_freem(m); 705 return; 706 } 707 708 otos = ip->ip_tos; 709 m_adj(m, off); 710 711 if (m->m_len < sizeof(*ip6)) { 712 m = m_pullup(m, sizeof(*ip6)); 713 if (!m) 714 return; 715 } 716 ip6 = mtod(m, struct ip6_hdr *); 717 718 /* 719 * perform sanity check against inner src/dst. 720 * for source, perform ingress filter as well. 721 */ 722 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 723 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 724 m_freem(m); 725 return; 726 } 727 728 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 729 if ((ifp->if_flags & IFF_LINK1) != 0) 730 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 731 else 732 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 733 ip6->ip6_flow &= ~htonl(0xff << 20); 734 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 735 736 m->m_pkthdr.rcvif = ifp; 737 738 if (ifp->if_bpf) { 739 /* 740 * We need to prepend the address family as 741 * a four byte field. Cons up a dummy header 742 * to pacify bpf. This is safe because bpf 743 * will only read from the mbuf (i.e., it won't 744 * try to free it or keep a pointer a to it). 745 */ 746 u_int32_t af = AF_INET6; 747 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 748 } 749 750 /* 751 * Put the packet to the network layer input queue according to the 752 * specified address family. 753 * See net/if_gif.c for possible issues with packet processing 754 * reorder due to extra queueing. 755 */ 756 ifp->if_ipackets++; 757 ifp->if_ibytes += m->m_pkthdr.len; 758 netisr_dispatch(NETISR_IPV6, m); 759 } 760 761 /* ARGSUSED */ 762 static void 763 stf_rtrequest(cmd, rt, info) 764 int cmd; 765 struct rtentry *rt; 766 struct rt_addrinfo *info; 767 { 768 RT_LOCK_ASSERT(rt); 769 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 770 } 771 772 static int 773 stf_ioctl(ifp, cmd, data) 774 struct ifnet *ifp; 775 u_long cmd; 776 caddr_t data; 777 { 778 struct ifaddr *ifa; 779 struct ifreq *ifr; 780 struct sockaddr_in6 *sin6; 781 struct in_addr addr; 782 int error; 783 784 error = 0; 785 switch (cmd) { 786 case SIOCSIFADDR: 787 ifa = (struct ifaddr *)data; 788 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 789 error = EAFNOSUPPORT; 790 break; 791 } 792 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 793 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 794 error = EINVAL; 795 break; 796 } 797 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 798 if (isrfc1918addr(&addr)) { 799 error = EINVAL; 800 break; 801 } 802 803 ifa->ifa_rtrequest = stf_rtrequest; 804 ifp->if_flags |= IFF_UP; 805 break; 806 807 case SIOCADDMULTI: 808 case SIOCDELMULTI: 809 ifr = (struct ifreq *)data; 810 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 811 ; 812 else 813 error = EAFNOSUPPORT; 814 break; 815 816 default: 817 error = EINVAL; 818 break; 819 } 820 821 return error; 822 } 823