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/mbuf.h> 86 #include <sys/errno.h> 87 #include <sys/kernel.h> 88 #include <sys/module.h> 89 #include <sys/protosw.h> 90 #include <sys/queue.h> 91 #include <machine/cpu.h> 92 93 #include <sys/malloc.h> 94 95 #include <net/if.h> 96 #include <net/if_clone.h> 97 #include <net/route.h> 98 #include <net/netisr.h> 99 #include <net/if_types.h> 100 #include <net/if_stf.h> 101 102 #include <netinet/in.h> 103 #include <netinet/in_systm.h> 104 #include <netinet/ip.h> 105 #include <netinet/ip_var.h> 106 #include <netinet/in_var.h> 107 108 #include <netinet/ip6.h> 109 #include <netinet6/ip6_var.h> 110 #include <netinet6/in6_var.h> 111 #include <netinet/ip_ecn.h> 112 113 #include <netinet/ip_encap.h> 114 115 #include <machine/stdarg.h> 116 117 #include <net/bpf.h> 118 119 #include <security/mac/mac_framework.h> 120 121 #define STFNAME "stf" 122 #define STFUNIT 0 123 124 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 125 126 /* 127 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 128 * struct in_addr *; use bcopy() instead. 129 */ 130 #define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 131 132 struct stf_softc { 133 struct ifnet *sc_ifp; 134 union { 135 struct route __sc_ro4; 136 struct route_in6 __sc_ro6; /* just for safety */ 137 } __sc_ro46; 138 #define sc_ro __sc_ro46.__sc_ro4 139 const struct encaptab *encap_cookie; 140 }; 141 #define STF2IFP(sc) ((sc)->sc_ifp) 142 143 /* 144 * XXXRW: Note that mutable fields in the softc are not currently locked: 145 * in particular, sc_ro needs to be protected from concurrent entrance 146 * of stf_output(). 147 */ 148 static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 149 static const int ip_stf_ttl = 40; 150 151 extern struct domain inetdomain; 152 struct protosw in_stf_protosw = { 153 .pr_type = SOCK_RAW, 154 .pr_domain = &inetdomain, 155 .pr_protocol = IPPROTO_IPV6, 156 .pr_flags = PR_ATOMIC|PR_ADDR, 157 .pr_input = in_stf_input, 158 .pr_output = (pr_output_t *)rip_output, 159 .pr_ctloutput = rip_ctloutput, 160 .pr_usrreqs = &rip_usrreqs 161 }; 162 163 static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 164 165 static int stfmodevent(module_t, int, void *); 166 static int stf_encapcheck(const struct mbuf *, int, int, void *); 167 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 168 static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 169 struct rtentry *); 170 static int isrfc1918addr(struct in_addr *); 171 static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 172 struct ifnet *); 173 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 174 struct ifnet *); 175 static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 176 static int stf_ioctl(struct ifnet *, u_long, caddr_t); 177 178 static int stf_clone_match(struct if_clone *, const char *); 179 static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 180 static int stf_clone_destroy(struct if_clone *, struct ifnet *); 181 struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 182 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 183 184 static int 185 stf_clone_match(struct if_clone *ifc, const char *name) 186 { 187 int i; 188 189 for(i = 0; stfnames[i] != NULL; i++) { 190 if (strcmp(stfnames[i], name) == 0) 191 return (1); 192 } 193 194 return (0); 195 } 196 197 static int 198 stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 199 { 200 int err, unit; 201 struct stf_softc *sc; 202 struct ifnet *ifp; 203 204 /* 205 * We can only have one unit, but since unit allocation is 206 * already locked, we use it to keep from allocating extra 207 * interfaces. 208 */ 209 unit = STFUNIT; 210 err = ifc_alloc_unit(ifc, &unit); 211 if (err != 0) 212 return (err); 213 214 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 215 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 216 if (ifp == NULL) { 217 free(sc, M_STF); 218 ifc_free_unit(ifc, unit); 219 return (ENOSPC); 220 } 221 ifp->if_softc = sc; 222 223 /* 224 * Set the name manually rather then using if_initname because 225 * we don't conform to the default naming convention for interfaces. 226 */ 227 strlcpy(ifp->if_xname, name, IFNAMSIZ); 228 ifp->if_dname = ifc->ifc_name; 229 ifp->if_dunit = IF_DUNIT_NONE; 230 231 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 232 stf_encapcheck, &in_stf_protosw, sc); 233 if (sc->encap_cookie == NULL) { 234 if_printf(ifp, "attach failed\n"); 235 free(sc, M_STF); 236 ifc_free_unit(ifc, unit); 237 return (ENOMEM); 238 } 239 240 ifp->if_mtu = IPV6_MMTU; 241 ifp->if_ioctl = stf_ioctl; 242 ifp->if_output = stf_output; 243 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN; 244 if_attach(ifp); 245 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 246 return (0); 247 } 248 249 static int 250 stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 251 { 252 struct stf_softc *sc = ifp->if_softc; 253 int err; 254 255 err = encap_detach(sc->encap_cookie); 256 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 257 bpfdetach(ifp); 258 if_detach(ifp); 259 if_free(ifp); 260 261 free(sc, M_STF); 262 ifc_free_unit(ifc, STFUNIT); 263 264 return (0); 265 } 266 267 static int 268 stfmodevent(mod, type, data) 269 module_t mod; 270 int type; 271 void *data; 272 { 273 274 switch (type) { 275 case MOD_LOAD: 276 if_clone_attach(&stf_cloner); 277 break; 278 case MOD_UNLOAD: 279 if_clone_detach(&stf_cloner); 280 break; 281 default: 282 return (EOPNOTSUPP); 283 } 284 285 return (0); 286 } 287 288 static moduledata_t stf_mod = { 289 "if_stf", 290 stfmodevent, 291 0 292 }; 293 294 DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 295 296 static int 297 stf_encapcheck(m, off, proto, arg) 298 const struct mbuf *m; 299 int off; 300 int proto; 301 void *arg; 302 { 303 struct ip ip; 304 struct in6_ifaddr *ia6; 305 struct stf_softc *sc; 306 struct in_addr a, b, mask; 307 308 sc = (struct stf_softc *)arg; 309 if (sc == NULL) 310 return 0; 311 312 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 313 return 0; 314 315 /* IFF_LINK0 means "no decapsulation" */ 316 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 317 return 0; 318 319 if (proto != IPPROTO_IPV6) 320 return 0; 321 322 /* LINTED const cast */ 323 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 324 325 if (ip.ip_v != 4) 326 return 0; 327 328 ia6 = stf_getsrcifa6(STF2IFP(sc)); 329 if (ia6 == NULL) 330 return 0; 331 332 /* 333 * check if IPv4 dst matches the IPv4 address derived from the 334 * local 6to4 address. 335 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 336 */ 337 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 338 sizeof(ip.ip_dst)) != 0) 339 return 0; 340 341 /* 342 * check if IPv4 src matches the IPv4 address derived from the 343 * local 6to4 address masked by prefixmask. 344 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 345 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 346 */ 347 bzero(&a, sizeof(a)); 348 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 349 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 350 a.s_addr &= mask.s_addr; 351 b = ip.ip_src; 352 b.s_addr &= mask.s_addr; 353 if (a.s_addr != b.s_addr) 354 return 0; 355 356 /* stf interface makes single side match only */ 357 return 32; 358 } 359 360 static struct in6_ifaddr * 361 stf_getsrcifa6(ifp) 362 struct ifnet *ifp; 363 { 364 struct ifaddr *ia; 365 struct in_ifaddr *ia4; 366 struct sockaddr_in6 *sin6; 367 struct in_addr in; 368 369 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) { 370 if (ia->ifa_addr->sa_family != AF_INET6) 371 continue; 372 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 373 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 374 continue; 375 376 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 377 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 378 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 379 break; 380 if (ia4 == NULL) 381 continue; 382 383 return (struct in6_ifaddr *)ia; 384 } 385 386 return NULL; 387 } 388 389 static int 390 stf_output(ifp, m, dst, rt) 391 struct ifnet *ifp; 392 struct mbuf *m; 393 struct sockaddr *dst; 394 struct rtentry *rt; 395 { 396 struct stf_softc *sc; 397 struct sockaddr_in6 *dst6; 398 struct in_addr in4; 399 caddr_t ptr; 400 struct sockaddr_in *dst4; 401 u_int8_t tos; 402 struct ip *ip; 403 struct ip6_hdr *ip6; 404 struct in6_ifaddr *ia6; 405 u_int32_t af; 406 #ifdef MAC 407 int error; 408 409 error = mac_ifnet_check_transmit(ifp, m); 410 if (error) { 411 m_freem(m); 412 return (error); 413 } 414 #endif 415 416 sc = ifp->if_softc; 417 dst6 = (struct sockaddr_in6 *)dst; 418 419 /* just in case */ 420 if ((ifp->if_flags & IFF_UP) == 0) { 421 m_freem(m); 422 ifp->if_oerrors++; 423 return ENETDOWN; 424 } 425 426 /* 427 * If we don't have an ip4 address that match my inner ip6 address, 428 * we shouldn't generate output. Without this check, we'll end up 429 * using wrong IPv4 source. 430 */ 431 ia6 = stf_getsrcifa6(ifp); 432 if (ia6 == NULL) { 433 m_freem(m); 434 ifp->if_oerrors++; 435 return ENETDOWN; 436 } 437 438 if (m->m_len < sizeof(*ip6)) { 439 m = m_pullup(m, sizeof(*ip6)); 440 if (!m) { 441 ifp->if_oerrors++; 442 return ENOBUFS; 443 } 444 } 445 ip6 = mtod(m, struct ip6_hdr *); 446 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 447 448 /* 449 * BPF writes need to be handled specially. 450 * This is a null operation, nothing here checks dst->sa_family. 451 */ 452 if (dst->sa_family == AF_UNSPEC) { 453 bcopy(dst->sa_data, &af, sizeof(af)); 454 dst->sa_family = af; 455 } 456 457 /* 458 * Pickup the right outer dst addr from the list of candidates. 459 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 460 */ 461 ptr = NULL; 462 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 463 ptr = GET_V4(&ip6->ip6_dst); 464 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 465 ptr = GET_V4(&dst6->sin6_addr); 466 else { 467 m_freem(m); 468 ifp->if_oerrors++; 469 return ENETUNREACH; 470 } 471 bcopy(ptr, &in4, sizeof(in4)); 472 473 if (bpf_peers_present(ifp->if_bpf)) { 474 /* 475 * We need to prepend the address family as 476 * a four byte field. Cons up a dummy header 477 * to pacify bpf. This is safe because bpf 478 * will only read from the mbuf (i.e., it won't 479 * try to free it or keep a pointer a to it). 480 */ 481 af = AF_INET6; 482 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 483 } 484 485 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 486 if (m && m->m_len < sizeof(struct ip)) 487 m = m_pullup(m, sizeof(struct ip)); 488 if (m == NULL) { 489 ifp->if_oerrors++; 490 return ENOBUFS; 491 } 492 ip = mtod(m, struct ip *); 493 494 bzero(ip, sizeof(*ip)); 495 496 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 497 &ip->ip_src, sizeof(ip->ip_src)); 498 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 499 ip->ip_p = IPPROTO_IPV6; 500 ip->ip_ttl = ip_stf_ttl; 501 ip->ip_len = m->m_pkthdr.len; /*host order*/ 502 if (ifp->if_flags & IFF_LINK1) 503 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 504 else 505 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 506 507 /* 508 * XXXRW: Locking of sc_ro required. 509 */ 510 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 511 if (dst4->sin_family != AF_INET || 512 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 513 /* cache route doesn't match */ 514 dst4->sin_family = AF_INET; 515 dst4->sin_len = sizeof(struct sockaddr_in); 516 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 517 if (sc->sc_ro.ro_rt) { 518 RTFREE(sc->sc_ro.ro_rt); 519 sc->sc_ro.ro_rt = NULL; 520 } 521 } 522 523 if (sc->sc_ro.ro_rt == NULL) { 524 rtalloc(&sc->sc_ro); 525 if (sc->sc_ro.ro_rt == NULL) { 526 m_freem(m); 527 ifp->if_oerrors++; 528 return ENETUNREACH; 529 } 530 } 531 532 ifp->if_opackets++; 533 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 534 } 535 536 static int 537 isrfc1918addr(in) 538 struct in_addr *in; 539 { 540 /* 541 * returns 1 if private address range: 542 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 543 */ 544 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 545 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 546 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 547 return 1; 548 549 return 0; 550 } 551 552 static int 553 stf_checkaddr4(sc, in, inifp) 554 struct stf_softc *sc; 555 struct in_addr *in; 556 struct ifnet *inifp; /* incoming interface */ 557 { 558 struct in_ifaddr *ia4; 559 560 /* 561 * reject packets with the following address: 562 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 563 */ 564 if (IN_MULTICAST(ntohl(in->s_addr))) 565 return -1; 566 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 567 case 0: case 127: case 255: 568 return -1; 569 } 570 571 /* 572 * reject packets with private address range. 573 * (requirement from RFC3056 section 2 1st paragraph) 574 */ 575 if (isrfc1918addr(in)) 576 return -1; 577 578 /* 579 * reject packets with broadcast 580 */ 581 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 582 ia4; 583 ia4 = TAILQ_NEXT(ia4, ia_link)) 584 { 585 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 586 continue; 587 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 588 return -1; 589 } 590 591 /* 592 * perform ingress filter 593 */ 594 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 595 struct sockaddr_in sin; 596 struct rtentry *rt; 597 598 bzero(&sin, sizeof(sin)); 599 sin.sin_family = AF_INET; 600 sin.sin_len = sizeof(struct sockaddr_in); 601 sin.sin_addr = *in; 602 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 603 if (!rt || rt->rt_ifp != inifp) { 604 #if 0 605 log(LOG_WARNING, "%s: packet from 0x%x dropped " 606 "due to ingress filter\n", if_name(STF2IFP(sc)), 607 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 608 #endif 609 if (rt) 610 RTFREE_LOCKED(rt); 611 return -1; 612 } 613 RTFREE_LOCKED(rt); 614 } 615 616 return 0; 617 } 618 619 static int 620 stf_checkaddr6(sc, in6, inifp) 621 struct stf_softc *sc; 622 struct in6_addr *in6; 623 struct ifnet *inifp; /* incoming interface */ 624 { 625 /* 626 * check 6to4 addresses 627 */ 628 if (IN6_IS_ADDR_6TO4(in6)) { 629 struct in_addr in4; 630 bcopy(GET_V4(in6), &in4, sizeof(in4)); 631 return stf_checkaddr4(sc, &in4, inifp); 632 } 633 634 /* 635 * reject anything that look suspicious. the test is implemented 636 * in ip6_input too, but we check here as well to 637 * (1) reject bad packets earlier, and 638 * (2) to be safe against future ip6_input change. 639 */ 640 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 641 return -1; 642 643 return 0; 644 } 645 646 void 647 in_stf_input(m, off) 648 struct mbuf *m; 649 int off; 650 { 651 int proto; 652 struct stf_softc *sc; 653 struct ip *ip; 654 struct ip6_hdr *ip6; 655 u_int8_t otos, itos; 656 struct ifnet *ifp; 657 658 proto = mtod(m, struct ip *)->ip_p; 659 660 if (proto != IPPROTO_IPV6) { 661 m_freem(m); 662 return; 663 } 664 665 ip = mtod(m, struct ip *); 666 667 sc = (struct stf_softc *)encap_getarg(m); 668 669 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 670 m_freem(m); 671 return; 672 } 673 674 ifp = STF2IFP(sc); 675 676 #ifdef MAC 677 mac_ifnet_create_mbuf(ifp, m); 678 #endif 679 680 /* 681 * perform sanity check against outer src/dst. 682 * for source, perform ingress filter as well. 683 */ 684 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 685 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 686 m_freem(m); 687 return; 688 } 689 690 otos = ip->ip_tos; 691 m_adj(m, off); 692 693 if (m->m_len < sizeof(*ip6)) { 694 m = m_pullup(m, sizeof(*ip6)); 695 if (!m) 696 return; 697 } 698 ip6 = mtod(m, struct ip6_hdr *); 699 700 /* 701 * perform sanity check against inner src/dst. 702 * for source, perform ingress filter as well. 703 */ 704 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 705 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 706 m_freem(m); 707 return; 708 } 709 710 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 711 if ((ifp->if_flags & IFF_LINK1) != 0) 712 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 713 else 714 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 715 ip6->ip6_flow &= ~htonl(0xff << 20); 716 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 717 718 m->m_pkthdr.rcvif = ifp; 719 720 if (bpf_peers_present(ifp->if_bpf)) { 721 /* 722 * We need to prepend the address family as 723 * a four byte field. Cons up a dummy header 724 * to pacify bpf. This is safe because bpf 725 * will only read from the mbuf (i.e., it won't 726 * try to free it or keep a pointer a to it). 727 */ 728 u_int32_t af = AF_INET6; 729 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 730 } 731 732 /* 733 * Put the packet to the network layer input queue according to the 734 * specified address family. 735 * See net/if_gif.c for possible issues with packet processing 736 * reorder due to extra queueing. 737 */ 738 ifp->if_ipackets++; 739 ifp->if_ibytes += m->m_pkthdr.len; 740 netisr_dispatch(NETISR_IPV6, m); 741 } 742 743 /* ARGSUSED */ 744 static void 745 stf_rtrequest(cmd, rt, info) 746 int cmd; 747 struct rtentry *rt; 748 struct rt_addrinfo *info; 749 { 750 RT_LOCK_ASSERT(rt); 751 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 752 } 753 754 static int 755 stf_ioctl(ifp, cmd, data) 756 struct ifnet *ifp; 757 u_long cmd; 758 caddr_t data; 759 { 760 struct ifaddr *ifa; 761 struct ifreq *ifr; 762 struct sockaddr_in6 *sin6; 763 struct in_addr addr; 764 int error; 765 766 error = 0; 767 switch (cmd) { 768 case SIOCSIFADDR: 769 ifa = (struct ifaddr *)data; 770 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 771 error = EAFNOSUPPORT; 772 break; 773 } 774 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 775 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 776 error = EINVAL; 777 break; 778 } 779 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 780 if (isrfc1918addr(&addr)) { 781 error = EINVAL; 782 break; 783 } 784 785 ifa->ifa_rtrequest = stf_rtrequest; 786 ifp->if_flags |= IFF_UP; 787 break; 788 789 case SIOCADDMULTI: 790 case SIOCDELMULTI: 791 ifr = (struct ifreq *)data; 792 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 793 ; 794 else 795 error = EAFNOSUPPORT; 796 break; 797 798 default: 799 error = EINVAL; 800 break; 801 } 802 803 return error; 804 } 805