if_stf.c revision 181803
1/* $FreeBSD: head/sys/net/if_stf.c 181803 2008-08-17 23:27:27Z bz $ */ 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/proc.h> 91#include <sys/queue.h> 92#include <machine/cpu.h> 93 94#include <sys/malloc.h> 95#include <sys/vimage.h> 96 97#include <net/if.h> 98#include <net/if_clone.h> 99#include <net/route.h> 100#include <net/netisr.h> 101#include <net/if_types.h> 102#include <net/if_stf.h> 103 104#include <netinet/in.h> 105#include <netinet/in_systm.h> 106#include <netinet/ip.h> 107#include <netinet/ip_var.h> 108#include <netinet/in_var.h> 109 110#include <netinet/ip6.h> 111#include <netinet6/ip6_var.h> 112#include <netinet6/in6_var.h> 113#include <netinet/ip_ecn.h> 114 115#include <netinet/ip_encap.h> 116 117#include <machine/stdarg.h> 118 119#include <net/bpf.h> 120 121#include <security/mac/mac_framework.h> 122 123#define STFNAME "stf" 124#define STFUNIT 0 125 126#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 127 128/* 129 * XXX: Return a pointer with 16-bit aligned. Don't cast it to 130 * struct in_addr *; use bcopy() instead. 131 */ 132#define GET_V4(x) ((caddr_t)(&(x)->s6_addr16[1])) 133 134struct stf_softc { 135 struct ifnet *sc_ifp; 136 union { 137 struct route __sc_ro4; 138 struct route_in6 __sc_ro6; /* just for safety */ 139 } __sc_ro46; 140#define sc_ro __sc_ro46.__sc_ro4 141 u_int sc_fibnum; 142 const struct encaptab *encap_cookie; 143}; 144#define STF2IFP(sc) ((sc)->sc_ifp) 145 146/* 147 * XXXRW: Note that mutable fields in the softc are not currently locked: 148 * in particular, sc_ro needs to be protected from concurrent entrance 149 * of stf_output(). 150 */ 151static MALLOC_DEFINE(M_STF, STFNAME, "6to4 Tunnel Interface"); 152static const int ip_stf_ttl = 40; 153 154extern struct domain inetdomain; 155struct protosw in_stf_protosw = { 156 .pr_type = SOCK_RAW, 157 .pr_domain = &inetdomain, 158 .pr_protocol = IPPROTO_IPV6, 159 .pr_flags = PR_ATOMIC|PR_ADDR, 160 .pr_input = in_stf_input, 161 .pr_output = (pr_output_t *)rip_output, 162 .pr_ctloutput = rip_ctloutput, 163 .pr_usrreqs = &rip_usrreqs 164}; 165 166static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; 167 168static int stfmodevent(module_t, int, void *); 169static int stf_encapcheck(const struct mbuf *, int, int, void *); 170static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 171static int stf_output(struct ifnet *, struct mbuf *, struct sockaddr *, 172 struct rtentry *); 173static int isrfc1918addr(struct in_addr *); 174static int stf_checkaddr4(struct stf_softc *, struct in_addr *, 175 struct ifnet *); 176static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, 177 struct ifnet *); 178static void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 179static int stf_ioctl(struct ifnet *, u_long, caddr_t); 180 181static int stf_clone_match(struct if_clone *, const char *); 182static int stf_clone_create(struct if_clone *, char *, size_t, caddr_t); 183static int stf_clone_destroy(struct if_clone *, struct ifnet *); 184struct if_clone stf_cloner = IFC_CLONE_INITIALIZER(STFNAME, NULL, 0, 185 NULL, stf_clone_match, stf_clone_create, stf_clone_destroy); 186 187static int 188stf_clone_match(struct if_clone *ifc, const char *name) 189{ 190 int i; 191 192 for(i = 0; stfnames[i] != NULL; i++) { 193 if (strcmp(stfnames[i], name) == 0) 194 return (1); 195 } 196 197 return (0); 198} 199 200static int 201stf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) 202{ 203 int err, unit; 204 struct stf_softc *sc; 205 struct ifnet *ifp; 206 207 /* 208 * We can only have one unit, but since unit allocation is 209 * already locked, we use it to keep from allocating extra 210 * interfaces. 211 */ 212 unit = STFUNIT; 213 err = ifc_alloc_unit(ifc, &unit); 214 if (err != 0) 215 return (err); 216 217 sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); 218 ifp = STF2IFP(sc) = if_alloc(IFT_STF); 219 if (ifp == NULL) { 220 free(sc, M_STF); 221 ifc_free_unit(ifc, unit); 222 return (ENOSPC); 223 } 224 ifp->if_softc = sc; 225 sc->sc_fibnum = curthread->td_proc->p_fibnum; 226 227 /* 228 * Set the name manually rather then using if_initname because 229 * we don't conform to the default naming convention for interfaces. 230 */ 231 strlcpy(ifp->if_xname, name, IFNAMSIZ); 232 ifp->if_dname = ifc->ifc_name; 233 ifp->if_dunit = IF_DUNIT_NONE; 234 235 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 236 stf_encapcheck, &in_stf_protosw, sc); 237 if (sc->encap_cookie == NULL) { 238 if_printf(ifp, "attach failed\n"); 239 free(sc, M_STF); 240 ifc_free_unit(ifc, unit); 241 return (ENOMEM); 242 } 243 244 ifp->if_mtu = IPV6_MMTU; 245 ifp->if_ioctl = stf_ioctl; 246 ifp->if_output = stf_output; 247 ifp->if_snd.ifq_maxlen = IFQ_MAXLEN; 248 if_attach(ifp); 249 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 250 return (0); 251} 252 253static int 254stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp) 255{ 256 struct stf_softc *sc = ifp->if_softc; 257 int err; 258 259 err = encap_detach(sc->encap_cookie); 260 KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); 261 bpfdetach(ifp); 262 if_detach(ifp); 263 if_free(ifp); 264 265 free(sc, M_STF); 266 ifc_free_unit(ifc, STFUNIT); 267 268 return (0); 269} 270 271static int 272stfmodevent(mod, type, data) 273 module_t mod; 274 int type; 275 void *data; 276{ 277 278 switch (type) { 279 case MOD_LOAD: 280 if_clone_attach(&stf_cloner); 281 break; 282 case MOD_UNLOAD: 283 if_clone_detach(&stf_cloner); 284 break; 285 default: 286 return (EOPNOTSUPP); 287 } 288 289 return (0); 290} 291 292static moduledata_t stf_mod = { 293 "if_stf", 294 stfmodevent, 295 0 296}; 297 298DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 299 300static int 301stf_encapcheck(m, off, proto, arg) 302 const struct mbuf *m; 303 int off; 304 int proto; 305 void *arg; 306{ 307 struct ip ip; 308 struct in6_ifaddr *ia6; 309 struct stf_softc *sc; 310 struct in_addr a, b, mask; 311 312 sc = (struct stf_softc *)arg; 313 if (sc == NULL) 314 return 0; 315 316 if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) 317 return 0; 318 319 /* IFF_LINK0 means "no decapsulation" */ 320 if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) 321 return 0; 322 323 if (proto != IPPROTO_IPV6) 324 return 0; 325 326 /* LINTED const cast */ 327 m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); 328 329 if (ip.ip_v != 4) 330 return 0; 331 332 ia6 = stf_getsrcifa6(STF2IFP(sc)); 333 if (ia6 == NULL) 334 return 0; 335 336 /* 337 * check if IPv4 dst matches the IPv4 address derived from the 338 * local 6to4 address. 339 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 340 */ 341 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 342 sizeof(ip.ip_dst)) != 0) 343 return 0; 344 345 /* 346 * check if IPv4 src matches the IPv4 address derived from the 347 * local 6to4 address masked by prefixmask. 348 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 349 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 350 */ 351 bzero(&a, sizeof(a)); 352 bcopy(GET_V4(&ia6->ia_addr.sin6_addr), &a, sizeof(a)); 353 bcopy(GET_V4(&ia6->ia_prefixmask.sin6_addr), &mask, sizeof(mask)); 354 a.s_addr &= mask.s_addr; 355 b = ip.ip_src; 356 b.s_addr &= mask.s_addr; 357 if (a.s_addr != b.s_addr) 358 return 0; 359 360 /* stf interface makes single side match only */ 361 return 32; 362} 363 364static struct in6_ifaddr * 365stf_getsrcifa6(ifp) 366 struct ifnet *ifp; 367{ 368 struct ifaddr *ia; 369 struct in_ifaddr *ia4; 370 struct sockaddr_in6 *sin6; 371 struct in_addr in; 372 373 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) { 374 if (ia->ifa_addr->sa_family != AF_INET6) 375 continue; 376 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 377 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 378 continue; 379 380 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 381 LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) 382 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 383 break; 384 if (ia4 == NULL) 385 continue; 386 387 return (struct in6_ifaddr *)ia; 388 } 389 390 return NULL; 391} 392 393static int 394stf_output(ifp, m, dst, rt) 395 struct ifnet *ifp; 396 struct mbuf *m; 397 struct sockaddr *dst; 398 struct rtentry *rt; 399{ 400 struct stf_softc *sc; 401 struct sockaddr_in6 *dst6; 402 struct in_addr in4; 403 caddr_t ptr; 404 struct sockaddr_in *dst4; 405 u_int8_t tos; 406 struct ip *ip; 407 struct ip6_hdr *ip6; 408 struct in6_ifaddr *ia6; 409 u_int32_t af; 410#ifdef MAC 411 int error; 412 413 error = mac_ifnet_check_transmit(ifp, m); 414 if (error) { 415 m_freem(m); 416 return (error); 417 } 418#endif 419 420 sc = ifp->if_softc; 421 dst6 = (struct sockaddr_in6 *)dst; 422 423 /* just in case */ 424 if ((ifp->if_flags & IFF_UP) == 0) { 425 m_freem(m); 426 ifp->if_oerrors++; 427 return ENETDOWN; 428 } 429 430 /* 431 * If we don't have an ip4 address that match my inner ip6 address, 432 * we shouldn't generate output. Without this check, we'll end up 433 * using wrong IPv4 source. 434 */ 435 ia6 = stf_getsrcifa6(ifp); 436 if (ia6 == NULL) { 437 m_freem(m); 438 ifp->if_oerrors++; 439 return ENETDOWN; 440 } 441 442 if (m->m_len < sizeof(*ip6)) { 443 m = m_pullup(m, sizeof(*ip6)); 444 if (!m) { 445 ifp->if_oerrors++; 446 return ENOBUFS; 447 } 448 } 449 ip6 = mtod(m, struct ip6_hdr *); 450 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 451 452 /* 453 * BPF writes need to be handled specially. 454 * This is a null operation, nothing here checks dst->sa_family. 455 */ 456 if (dst->sa_family == AF_UNSPEC) { 457 bcopy(dst->sa_data, &af, sizeof(af)); 458 dst->sa_family = af; 459 } 460 461 /* 462 * Pickup the right outer dst addr from the list of candidates. 463 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 464 */ 465 ptr = NULL; 466 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 467 ptr = GET_V4(&ip6->ip6_dst); 468 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 469 ptr = GET_V4(&dst6->sin6_addr); 470 else { 471 m_freem(m); 472 ifp->if_oerrors++; 473 return ENETUNREACH; 474 } 475 bcopy(ptr, &in4, sizeof(in4)); 476 477 if (bpf_peers_present(ifp->if_bpf)) { 478 /* 479 * We need to prepend the address family as 480 * a four byte field. Cons up a dummy header 481 * to pacify bpf. This is safe because bpf 482 * will only read from the mbuf (i.e., it won't 483 * try to free it or keep a pointer a to it). 484 */ 485 af = AF_INET6; 486 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 487 } 488 489 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 490 if (m && m->m_len < sizeof(struct ip)) 491 m = m_pullup(m, sizeof(struct ip)); 492 if (m == NULL) { 493 ifp->if_oerrors++; 494 return ENOBUFS; 495 } 496 ip = mtod(m, struct ip *); 497 498 bzero(ip, sizeof(*ip)); 499 500 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 501 &ip->ip_src, sizeof(ip->ip_src)); 502 bcopy(&in4, &ip->ip_dst, sizeof(ip->ip_dst)); 503 ip->ip_p = IPPROTO_IPV6; 504 ip->ip_ttl = ip_stf_ttl; 505 ip->ip_len = m->m_pkthdr.len; /*host order*/ 506 if (ifp->if_flags & IFF_LINK1) 507 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 508 else 509 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 510 511 /* 512 * XXXRW: Locking of sc_ro required. 513 */ 514 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 515 if (dst4->sin_family != AF_INET || 516 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 517 /* cache route doesn't match */ 518 dst4->sin_family = AF_INET; 519 dst4->sin_len = sizeof(struct sockaddr_in); 520 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 521 if (sc->sc_ro.ro_rt) { 522 RTFREE(sc->sc_ro.ro_rt); 523 sc->sc_ro.ro_rt = NULL; 524 } 525 } 526 527 if (sc->sc_ro.ro_rt == NULL) { 528 rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); 529 if (sc->sc_ro.ro_rt == NULL) { 530 m_freem(m); 531 ifp->if_oerrors++; 532 return ENETUNREACH; 533 } 534 } 535 536 M_SETFIB(m, sc->sc_fibnum); 537 ifp->if_opackets++; 538 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 539} 540 541static int 542isrfc1918addr(in) 543 struct in_addr *in; 544{ 545 /* 546 * returns 1 if private address range: 547 * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 548 */ 549 if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || 550 (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || 551 (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) 552 return 1; 553 554 return 0; 555} 556 557static int 558stf_checkaddr4(sc, in, inifp) 559 struct stf_softc *sc; 560 struct in_addr *in; 561 struct ifnet *inifp; /* incoming interface */ 562{ 563 struct in_ifaddr *ia4; 564 565 /* 566 * reject packets with the following address: 567 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 568 */ 569 if (IN_MULTICAST(ntohl(in->s_addr))) 570 return -1; 571 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 572 case 0: case 127: case 255: 573 return -1; 574 } 575 576 /* 577 * reject packets with private address range. 578 * (requirement from RFC3056 section 2 1st paragraph) 579 */ 580 if (isrfc1918addr(in)) 581 return -1; 582 583 /* 584 * reject packets with broadcast 585 */ 586 for (ia4 = TAILQ_FIRST(&V_in_ifaddrhead); 587 ia4; 588 ia4 = TAILQ_NEXT(ia4, ia_link)) 589 { 590 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 591 continue; 592 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 593 return -1; 594 } 595 596 /* 597 * perform ingress filter 598 */ 599 if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { 600 struct sockaddr_in sin; 601 struct rtentry *rt; 602 603 bzero(&sin, sizeof(sin)); 604 sin.sin_family = AF_INET; 605 sin.sin_len = sizeof(struct sockaddr_in); 606 sin.sin_addr = *in; 607 rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 608 0UL, sc->sc_fibnum); 609 if (!rt || rt->rt_ifp != inifp) { 610#if 0 611 log(LOG_WARNING, "%s: packet from 0x%x dropped " 612 "due to ingress filter\n", if_name(STF2IFP(sc)), 613 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 614#endif 615 if (rt) 616 RTFREE_LOCKED(rt); 617 return -1; 618 } 619 RTFREE_LOCKED(rt); 620 } 621 622 return 0; 623} 624 625static int 626stf_checkaddr6(sc, in6, inifp) 627 struct stf_softc *sc; 628 struct in6_addr *in6; 629 struct ifnet *inifp; /* incoming interface */ 630{ 631 /* 632 * check 6to4 addresses 633 */ 634 if (IN6_IS_ADDR_6TO4(in6)) { 635 struct in_addr in4; 636 bcopy(GET_V4(in6), &in4, sizeof(in4)); 637 return stf_checkaddr4(sc, &in4, inifp); 638 } 639 640 /* 641 * reject anything that look suspicious. the test is implemented 642 * in ip6_input too, but we check here as well to 643 * (1) reject bad packets earlier, and 644 * (2) to be safe against future ip6_input change. 645 */ 646 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 647 return -1; 648 649 return 0; 650} 651 652void 653in_stf_input(m, off) 654 struct mbuf *m; 655 int off; 656{ 657 int proto; 658 struct stf_softc *sc; 659 struct ip *ip; 660 struct ip6_hdr *ip6; 661 u_int8_t otos, itos; 662 struct ifnet *ifp; 663 664 proto = mtod(m, struct ip *)->ip_p; 665 666 if (proto != IPPROTO_IPV6) { 667 m_freem(m); 668 return; 669 } 670 671 ip = mtod(m, struct ip *); 672 673 sc = (struct stf_softc *)encap_getarg(m); 674 675 if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { 676 m_freem(m); 677 return; 678 } 679 680 ifp = STF2IFP(sc); 681 682#ifdef MAC 683 mac_ifnet_create_mbuf(ifp, m); 684#endif 685 686 /* 687 * perform sanity check against outer src/dst. 688 * for source, perform ingress filter as well. 689 */ 690 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 691 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 692 m_freem(m); 693 return; 694 } 695 696 otos = ip->ip_tos; 697 m_adj(m, off); 698 699 if (m->m_len < sizeof(*ip6)) { 700 m = m_pullup(m, sizeof(*ip6)); 701 if (!m) 702 return; 703 } 704 ip6 = mtod(m, struct ip6_hdr *); 705 706 /* 707 * perform sanity check against inner src/dst. 708 * for source, perform ingress filter as well. 709 */ 710 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 711 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 712 m_freem(m); 713 return; 714 } 715 716 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 717 if ((ifp->if_flags & IFF_LINK1) != 0) 718 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 719 else 720 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 721 ip6->ip6_flow &= ~htonl(0xff << 20); 722 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 723 724 m->m_pkthdr.rcvif = ifp; 725 726 if (bpf_peers_present(ifp->if_bpf)) { 727 /* 728 * We need to prepend the address family as 729 * a four byte field. Cons up a dummy header 730 * to pacify bpf. This is safe because bpf 731 * will only read from the mbuf (i.e., it won't 732 * try to free it or keep a pointer a to it). 733 */ 734 u_int32_t af = AF_INET6; 735 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 736 } 737 738 /* 739 * Put the packet to the network layer input queue according to the 740 * specified address family. 741 * See net/if_gif.c for possible issues with packet processing 742 * reorder due to extra queueing. 743 */ 744 ifp->if_ipackets++; 745 ifp->if_ibytes += m->m_pkthdr.len; 746 netisr_dispatch(NETISR_IPV6, m); 747} 748 749/* ARGSUSED */ 750static void 751stf_rtrequest(cmd, rt, info) 752 int cmd; 753 struct rtentry *rt; 754 struct rt_addrinfo *info; 755{ 756 RT_LOCK_ASSERT(rt); 757 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 758} 759 760static int 761stf_ioctl(ifp, cmd, data) 762 struct ifnet *ifp; 763 u_long cmd; 764 caddr_t data; 765{ 766 struct ifaddr *ifa; 767 struct ifreq *ifr; 768 struct sockaddr_in6 *sin6; 769 struct in_addr addr; 770 int error; 771 772 error = 0; 773 switch (cmd) { 774 case SIOCSIFADDR: 775 ifa = (struct ifaddr *)data; 776 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 777 error = EAFNOSUPPORT; 778 break; 779 } 780 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 781 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 782 error = EINVAL; 783 break; 784 } 785 bcopy(GET_V4(&sin6->sin6_addr), &addr, sizeof(addr)); 786 if (isrfc1918addr(&addr)) { 787 error = EINVAL; 788 break; 789 } 790 791 ifa->ifa_rtrequest = stf_rtrequest; 792 ifp->if_flags |= IFF_UP; 793 break; 794 795 case SIOCADDMULTI: 796 case SIOCDELMULTI: 797 ifr = (struct ifreq *)data; 798 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 799 ; 800 else 801 error = EAFNOSUPPORT; 802 break; 803 804 default: 805 error = EINVAL; 806 break; 807 } 808 809 return error; 810} 811