if_stf.c revision 1.22
1 /* $NetBSD: if_stf.c,v 1.22 2001/11/13 00:49:35 lukem Exp $ */ 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 <sys/cdefs.h> 78 __KERNEL_RCSID(0, "$NetBSD: if_stf.c,v 1.22 2001/11/13 00:49:35 lukem Exp $"); 79 80 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 81 #include "opt_inet.h" 82 #include "opt_inet6.h" 83 #endif 84 #ifdef __NetBSD__ 85 #include "opt_inet.h" 86 #endif 87 88 #include <sys/param.h> 89 #include <sys/systm.h> 90 #include <sys/socket.h> 91 #include <sys/sockio.h> 92 #include <sys/mbuf.h> 93 #include <sys/errno.h> 94 #if !(defined(__FreeBSD__) && __FreeBSD__ >= 3) 95 #include <sys/ioctl.h> 96 #endif 97 #include <sys/protosw.h> 98 #ifdef __FreeBSD__ 99 #include <sys/kernel.h> 100 #endif 101 #include <sys/queue.h> 102 #include <sys/syslog.h> 103 #include <machine/cpu.h> 104 105 #if defined(__FreeBSD__) && __FreeBSD__ >= 3 106 #include <sys/malloc.h> 107 #endif 108 109 #include <net/if.h> 110 #include <net/route.h> 111 #include <net/netisr.h> 112 #include <net/if_types.h> 113 #include <net/if_stf.h> 114 115 #include <netinet/in.h> 116 #include <netinet/in_systm.h> 117 #include <netinet/ip.h> 118 #include <netinet/ip_var.h> 119 #include <netinet/in_var.h> 120 121 #include <netinet/ip6.h> 122 #include <netinet6/ip6_var.h> 123 #include <netinet6/in6_gif.h> 124 #include <netinet6/in6_var.h> 125 #include <netinet/ip_ecn.h> 126 127 #include <netinet/ip_encap.h> 128 129 #include <machine/stdarg.h> 130 131 #include <net/net_osdep.h> 132 133 #if defined(__FreeBSD__) && __FreeBSD__ >= 4 134 #include "bpf.h" 135 #define NBPFILTER NBPF 136 #else 137 #include "bpfilter.h" 138 #endif 139 #include "stf.h" 140 #include "gif.h" /*XXX*/ 141 142 #if NBPFILTER > 0 143 #include <net/bpf.h> 144 #endif 145 146 #if NGIF > 0 147 #include <net/if_gif.h> 148 #endif 149 150 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) 151 #define GET_V4(x) ((struct in_addr *)(&(x)->s6_addr16[1])) 152 153 struct stf_softc { 154 struct ifnet sc_if; /* common area */ 155 union { 156 struct route __sc_ro4; 157 struct route_in6 __sc_ro6; /* just for safety */ 158 } __sc_ro46; 159 #define sc_ro __sc_ro46.__sc_ro4 160 const struct encaptab *encap_cookie; 161 LIST_ENTRY(stf_softc) sc_list; 162 }; 163 164 LIST_HEAD(, stf_softc) stf_softc_list; 165 166 int stf_clone_create __P((struct if_clone *, int)); 167 void stf_clone_destroy __P((struct ifnet *)); 168 169 struct if_clone stf_cloner = 170 IF_CLONE_INITIALIZER("stf", stf_clone_create, stf_clone_destroy); 171 172 #if NGIF > 0 173 extern int ip_gif_ttl; /*XXX*/ 174 #else 175 static int ip_gif_ttl = 40; /*XXX*/ 176 #endif 177 178 extern struct protosw in_stf_protosw; 179 180 #ifdef __FreeBSD__ 181 void stfattach __P((void *)); 182 #else 183 void stfattach __P((int)); 184 #endif 185 static int stf_encapcheck __P((const struct mbuf *, int, int, void *)); 186 static struct in6_ifaddr *stf_getsrcifa6 __P((struct ifnet *)); 187 static int stf_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, 188 struct rtentry *)); 189 static int stf_checkaddr4 __P((struct stf_softc *, struct in_addr *, 190 struct ifnet *)); 191 static int stf_checkaddr6 __P((struct stf_softc *, struct in6_addr *, 192 struct ifnet *)); 193 static void stf_rtrequest __P((int, struct rtentry *, struct rt_addrinfo *)); 194 #if defined(__FreeBSD__) && __FreeBSD__ < 3 195 static int stf_ioctl __P((struct ifnet *, int, caddr_t)); 196 #else 197 static int stf_ioctl __P((struct ifnet *, u_long, caddr_t)); 198 #endif 199 200 /* ARGSUSED */ 201 void 202 stfattach(count) 203 int count; 204 { 205 206 LIST_INIT(&stf_softc_list); 207 if_clone_attach(&stf_cloner); 208 } 209 210 int 211 stf_clone_create(ifc, unit) 212 struct if_clone *ifc; 213 int unit; 214 { 215 struct stf_softc *sc; 216 217 if (LIST_FIRST(&stf_softc_list) != NULL) { 218 /* Only one stf interface is allowed. */ 219 return (EEXIST); 220 } 221 222 sc = malloc(sizeof(struct stf_softc), M_DEVBUF, M_WAIT); 223 memset(sc, 0, sizeof(struct stf_softc)); 224 225 sprintf(sc->sc_if.if_xname, "%s%d", ifc->ifc_name, unit); 226 227 sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, 228 stf_encapcheck, &in_stf_protosw, sc); 229 if (sc->encap_cookie == NULL) { 230 printf("%s: unable to attach encap\n", if_name(&sc->sc_if)); 231 free(sc, M_DEVBUF); 232 return (EIO); /* XXX */ 233 } 234 235 sc->sc_if.if_mtu = IPV6_MMTU; 236 sc->sc_if.if_flags = 0; 237 sc->sc_if.if_ioctl = stf_ioctl; 238 sc->sc_if.if_output = stf_output; 239 sc->sc_if.if_type = IFT_STF; 240 sc->sc_if.if_dlt = DLT_NULL; 241 #if defined(__FreeBSD__) && __FreeBSD__ >= 4 242 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN; 243 #endif 244 if_attach(&sc->sc_if); 245 if_alloc_sadl(&sc->sc_if); 246 #if NBPFILTER > 0 247 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 248 #endif 249 LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list); 250 return (0); 251 } 252 253 void 254 stf_clone_destroy(ifp) 255 struct ifnet *ifp; 256 { 257 struct stf_softc *sc = (void *) ifp; 258 259 LIST_REMOVE(sc, sc_list); 260 encap_detach(sc->encap_cookie); 261 #if NBPFILTER > 0 262 bpfdetach(ifp); 263 #endif 264 if_detach(ifp); 265 free(sc, M_DEVBUF); 266 } 267 268 #ifdef __FreeBSD__ 269 PSEUDO_SET(stfattach, if_stf); 270 #endif 271 272 static int 273 stf_encapcheck(m, off, proto, arg) 274 const struct mbuf *m; 275 int off; 276 int proto; 277 void *arg; 278 { 279 struct ip ip; 280 struct in6_ifaddr *ia6; 281 struct stf_softc *sc; 282 struct in_addr a, b; 283 284 sc = (struct stf_softc *)arg; 285 if (sc == NULL) 286 return 0; 287 288 if ((sc->sc_if.if_flags & IFF_UP) == 0) 289 return 0; 290 291 /* IFF_LINK0 means "no decapsulation" */ 292 if ((sc->sc_if.if_flags & IFF_LINK0) != 0) 293 return 0; 294 295 if (proto != IPPROTO_IPV6) 296 return 0; 297 298 /* LINTED const cast */ 299 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 300 301 if (ip.ip_v != 4) 302 return 0; 303 304 ia6 = stf_getsrcifa6(&sc->sc_if); 305 if (ia6 == NULL) 306 return 0; 307 308 /* 309 * check if IPv4 dst matches the IPv4 address derived from the 310 * local 6to4 address. 311 * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... 312 */ 313 if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, 314 sizeof(ip.ip_dst)) != 0) 315 return 0; 316 317 /* 318 * check if IPv4 src matches the IPv4 address derived from the 319 * local 6to4 address masked by prefixmask. 320 * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 321 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 322 */ 323 memset(&a, 0, sizeof(a)); 324 a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; 325 a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 326 b = ip.ip_src; 327 b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; 328 if (a.s_addr != b.s_addr) 329 return 0; 330 331 /* stf interface makes single side match only */ 332 return 32; 333 } 334 335 static struct in6_ifaddr * 336 stf_getsrcifa6(ifp) 337 struct ifnet *ifp; 338 { 339 struct ifaddr *ia; 340 struct in_ifaddr *ia4; 341 struct sockaddr_in6 *sin6; 342 struct in_addr in; 343 344 #if defined(__bsdi__) || (defined(__FreeBSD__) && __FreeBSD__ < 3) 345 for (ia = ifp->if_addrlist; ia; ia = ia->ifa_next) 346 #else 347 TAILQ_FOREACH(ia, &ifp->if_addrlist, ifa_list) 348 #endif 349 { 350 if (ia->ifa_addr == NULL) 351 continue; 352 if (ia->ifa_addr->sa_family != AF_INET6) 353 continue; 354 sin6 = (struct sockaddr_in6 *)ia->ifa_addr; 355 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) 356 continue; 357 358 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in)); 359 #ifdef __NetBSD__ 360 INADDR_TO_IA(in, ia4); 361 #else 362 #ifdef __OpenBSD__ 363 for (ia4 = TAILQ_FIRST(&in_ifaddr); 364 ia4; 365 ia4 = TAILQ_NEXT(ia4, ia_list)) 366 #elif defined(__FreeBSD__) && __FreeBSD__ >= 3 367 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 368 ia4; 369 ia4 = TAILQ_NEXT(ia4, ia_link)) 370 #else 371 for (ia4 = in_ifaddr; ia4 != NULL; ia4 = ia4->ia_next) 372 #endif 373 { 374 if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) 375 break; 376 } 377 #endif 378 if (ia4 == NULL) 379 continue; 380 381 return (struct in6_ifaddr *)ia; 382 } 383 384 return NULL; 385 } 386 387 static int 388 stf_output(ifp, m, dst, rt) 389 struct ifnet *ifp; 390 struct mbuf *m; 391 struct sockaddr *dst; 392 struct rtentry *rt; 393 { 394 struct stf_softc *sc; 395 struct sockaddr_in6 *dst6; 396 struct in_addr *in4; 397 struct sockaddr_in *dst4; 398 u_int8_t tos; 399 struct ip *ip; 400 struct ip6_hdr *ip6; 401 struct in6_ifaddr *ia6; 402 403 sc = (struct stf_softc*)ifp; 404 dst6 = (struct sockaddr_in6 *)dst; 405 406 /* just in case */ 407 if ((ifp->if_flags & IFF_UP) == 0) { 408 m_freem(m); 409 return ENETDOWN; 410 } 411 412 /* 413 * If we don't have an ip4 address that match my inner ip6 address, 414 * we shouldn't generate output. Without this check, we'll end up 415 * using wrong IPv4 source. 416 */ 417 ia6 = stf_getsrcifa6(ifp); 418 if (ia6 == NULL) { 419 m_freem(m); 420 return ENETDOWN; 421 } 422 423 if (m->m_len < sizeof(*ip6)) { 424 m = m_pullup(m, sizeof(*ip6)); 425 if (!m) 426 return ENOBUFS; 427 } 428 ip6 = mtod(m, struct ip6_hdr *); 429 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 430 431 /* 432 * Pickup the right outer dst addr from the list of candidates. 433 * ip6_dst has priority as it may be able to give us shorter IPv4 hops. 434 */ 435 if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) 436 in4 = GET_V4(&ip6->ip6_dst); 437 else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) 438 in4 = GET_V4(&dst6->sin6_addr); 439 else { 440 m_freem(m); 441 return ENETUNREACH; 442 } 443 444 #if NBPFILTER > 0 445 if (ifp->if_bpf) { 446 /* 447 * We need to prepend the address family as 448 * a four byte field. Cons up a dummy header 449 * to pacify bpf. This is safe because bpf 450 * will only read from the mbuf (i.e., it won't 451 * try to free it or keep a pointer a to it). 452 */ 453 struct mbuf m0; 454 u_int32_t af = AF_INET6; 455 456 m0.m_next = m; 457 m0.m_len = 4; 458 m0.m_data = (char *)⁡ 459 460 #ifdef HAVE_OLD_BPF 461 bpf_mtap(ifp, &m0); 462 #else 463 bpf_mtap(ifp->if_bpf, &m0); 464 #endif 465 } 466 #endif /*NBPFILTER > 0*/ 467 468 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 469 if (m && m->m_len < sizeof(struct ip)) 470 m = m_pullup(m, sizeof(struct ip)); 471 if (m == NULL) 472 return ENOBUFS; 473 ip = mtod(m, struct ip *); 474 475 memset(ip, 0, sizeof(*ip)); 476 477 bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), 478 &ip->ip_src, sizeof(ip->ip_src)); 479 bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst)); 480 ip->ip_p = IPPROTO_IPV6; 481 ip->ip_ttl = ip_gif_ttl; /*XXX*/ 482 ip->ip_len = m->m_pkthdr.len; /*host order*/ 483 if (ifp->if_flags & IFF_LINK1) 484 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); 485 else 486 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); 487 488 dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; 489 if (dst4->sin_family != AF_INET || 490 bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { 491 /* cache route doesn't match */ 492 dst4->sin_family = AF_INET; 493 dst4->sin_len = sizeof(struct sockaddr_in); 494 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); 495 if (sc->sc_ro.ro_rt) { 496 RTFREE(sc->sc_ro.ro_rt); 497 sc->sc_ro.ro_rt = NULL; 498 } 499 } 500 501 if (sc->sc_ro.ro_rt == NULL) { 502 rtalloc(&sc->sc_ro); 503 if (sc->sc_ro.ro_rt == NULL) { 504 m_freem(m); 505 return ENETUNREACH; 506 } 507 } 508 509 #ifndef __OpenBSD__ 510 return ip_output(m, NULL, &sc->sc_ro, 0, NULL); 511 #else 512 return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); 513 #endif 514 } 515 516 static int 517 stf_checkaddr4(sc, in, inifp) 518 struct stf_softc *sc; 519 struct in_addr *in; 520 struct ifnet *inifp; /* incoming interface */ 521 { 522 struct in_ifaddr *ia4; 523 524 /* 525 * reject packets with the following address: 526 * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 527 */ 528 if (IN_MULTICAST(in->s_addr)) 529 return -1; 530 switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { 531 case 0: case 127: case 255: 532 return -1; 533 } 534 535 /* 536 * reject packets with broadcast 537 */ 538 #if defined(__OpenBSD__) || defined(__NetBSD__) 539 TAILQ_FOREACH(ia4, &in_ifaddr, ia_list) 540 #elif defined(__FreeBSD__) && __FreeBSD__ >= 3 541 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); 542 ia4; 543 ia4 = TAILQ_NEXT(ia4, ia_link)) 544 #else 545 for (ia4 = in_ifaddr; ia4 != NULL; ia4 = ia4->ia_next) 546 #endif 547 { 548 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 549 continue; 550 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 551 return -1; 552 } 553 554 /* 555 * perform ingress filter 556 */ 557 if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { 558 struct sockaddr_in sin; 559 struct rtentry *rt; 560 561 memset(&sin, 0, sizeof(sin)); 562 sin.sin_family = AF_INET; 563 sin.sin_len = sizeof(struct sockaddr_in); 564 sin.sin_addr = *in; 565 #ifdef __FreeBSD__ 566 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 567 #else 568 rt = rtalloc1((struct sockaddr *)&sin, 0); 569 #endif 570 if (!rt || rt->rt_ifp != inifp) { 571 #if 0 572 log(LOG_WARNING, "%s: packet from 0x%x dropped " 573 "due to ingress filter\n", if_name(&sc->sc_if), 574 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 575 #endif 576 if (rt) 577 rtfree(rt); 578 return -1; 579 } 580 rtfree(rt); 581 } 582 583 return 0; 584 } 585 586 static int 587 stf_checkaddr6(sc, in6, inifp) 588 struct stf_softc *sc; 589 struct in6_addr *in6; 590 struct ifnet *inifp; /* incoming interface */ 591 { 592 /* 593 * check 6to4 addresses 594 */ 595 if (IN6_IS_ADDR_6TO4(in6)) 596 return stf_checkaddr4(sc, GET_V4(in6), inifp); 597 598 /* 599 * reject anything that look suspicious. the test is implemented 600 * in ip6_input too, but we check here as well to 601 * (1) reject bad packets earlier, and 602 * (2) to be safe against future ip6_input change. 603 */ 604 if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) 605 return -1; 606 607 return 0; 608 } 609 610 void 611 #if __STDC__ 612 in_stf_input(struct mbuf *m, ...) 613 #else 614 in_stf_input(m, va_alist) 615 struct mbuf *m; 616 #endif 617 { 618 int off, proto; 619 struct stf_softc *sc; 620 struct ip *ip; 621 struct ip6_hdr *ip6; 622 u_int8_t otos, itos; 623 int s, isr; 624 struct ifqueue *ifq = NULL; 625 struct ifnet *ifp; 626 va_list ap; 627 628 va_start(ap, m); 629 off = va_arg(ap, int); 630 proto = va_arg(ap, int); 631 va_end(ap); 632 633 if (proto != IPPROTO_IPV6) { 634 m_freem(m); 635 return; 636 } 637 638 ip = mtod(m, struct ip *); 639 640 sc = (struct stf_softc *)encap_getarg(m); 641 642 if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { 643 m_freem(m); 644 return; 645 } 646 647 ifp = &sc->sc_if; 648 649 /* 650 * perform sanity check against outer src/dst. 651 * for source, perform ingress filter as well. 652 */ 653 if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || 654 stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) { 655 m_freem(m); 656 return; 657 } 658 659 otos = ip->ip_tos; 660 m_adj(m, off); 661 662 if (m->m_len < sizeof(*ip6)) { 663 m = m_pullup(m, sizeof(*ip6)); 664 if (!m) 665 return; 666 } 667 ip6 = mtod(m, struct ip6_hdr *); 668 669 /* 670 * perform sanity check against inner src/dst. 671 * for source, perform ingress filter as well. 672 */ 673 if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || 674 stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { 675 m_freem(m); 676 return; 677 } 678 679 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 680 if ((ifp->if_flags & IFF_LINK1) != 0) 681 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 682 else 683 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 684 ip6->ip6_flow &= ~htonl(0xff << 20); 685 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 686 687 m->m_pkthdr.rcvif = ifp; 688 689 #if NBPFILTER > 0 690 if (ifp->if_bpf) { 691 /* 692 * We need to prepend the address family as 693 * a four byte field. Cons up a dummy header 694 * to pacify bpf. This is safe because bpf 695 * will only read from the mbuf (i.e., it won't 696 * try to free it or keep a pointer a to it). 697 */ 698 struct mbuf m0; 699 u_int32_t af = AF_INET6; 700 701 m0.m_next = m; 702 m0.m_len = 4; 703 m0.m_data = (char *)⁡ 704 705 #ifdef HAVE_OLD_BPF 706 bpf_mtap(ifp, &m0); 707 #else 708 bpf_mtap(ifp->if_bpf, &m0); 709 #endif 710 } 711 #endif /*NBPFILTER > 0*/ 712 713 /* 714 * Put the packet to the network layer input queue according to the 715 * specified address family. 716 * See net/if_gif.c for possible issues with packet processing 717 * reorder due to extra queueing. 718 */ 719 ifq = &ip6intrq; 720 isr = NETISR_IPV6; 721 722 s = splnet(); 723 if (IF_QFULL(ifq)) { 724 IF_DROP(ifq); /* update statistics */ 725 m_freem(m); 726 splx(s); 727 return; 728 } 729 IF_ENQUEUE(ifq, m); 730 schednetisr(isr); 731 ifp->if_ipackets++; 732 ifp->if_ibytes += m->m_pkthdr.len; 733 splx(s); 734 } 735 736 /* ARGSUSED */ 737 static void 738 stf_rtrequest(cmd, rt, info) 739 int cmd; 740 struct rtentry *rt; 741 struct rt_addrinfo *info; 742 { 743 744 if (rt) 745 rt->rt_rmx.rmx_mtu = IPV6_MMTU; 746 } 747 748 static int 749 stf_ioctl(ifp, cmd, data) 750 struct ifnet *ifp; 751 #if defined(__FreeBSD__) && __FreeBSD__ < 3 752 int cmd; 753 #else 754 u_long cmd; 755 #endif 756 caddr_t data; 757 { 758 struct ifaddr *ifa; 759 struct ifreq *ifr; 760 struct sockaddr_in6 *sin6; 761 int error; 762 763 error = 0; 764 switch (cmd) { 765 case SIOCSIFADDR: 766 ifa = (struct ifaddr *)data; 767 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { 768 error = EAFNOSUPPORT; 769 break; 770 } 771 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; 772 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { 773 ifa->ifa_rtrequest = stf_rtrequest; 774 ifp->if_flags |= IFF_UP; 775 } else 776 error = EINVAL; 777 break; 778 779 case SIOCADDMULTI: 780 case SIOCDELMULTI: 781 ifr = (struct ifreq *)data; 782 if (ifr && ifr->ifr_addr.sa_family == AF_INET6) 783 ; 784 else 785 error = EAFNOSUPPORT; 786 break; 787 788 default: 789 error = EINVAL; 790 break; 791 } 792 793 return error; 794 } 795
Indexes created Mon Oct 13 16:09:52 GMT 2025