| 1 | /* $NetBSD: if_stf.c,v 1.99 2016/08/18 11:38:58 knakahara 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 1.99 2016/08/18 11:38:58 knakahara Exp $" ); |
| 79 | |
| 80 | #ifdef _KERNEL_OPT |
| 81 | #include "opt_inet.h" |
| 82 | #include "stf.h" |
| 83 | #endif |
| 84 | |
| 85 | #ifndef INET6 |
| 86 | #error "pseudo-device stf requires options INET6" |
| 87 | #endif |
| 88 | |
| 89 | #include <sys/param.h> |
| 90 | #include <sys/systm.h> |
| 91 | #include <sys/socket.h> |
| 92 | #include <sys/sockio.h> |
| 93 | #include <sys/mbuf.h> |
| 94 | #include <sys/errno.h> |
| 95 | #include <sys/ioctl.h> |
| 96 | #include <sys/proc.h> |
| 97 | #include <sys/queue.h> |
| 98 | #include <sys/syslog.h> |
| 99 | #include <sys/device.h> |
| 100 | #include <sys/module.h> |
| 101 | |
| 102 | #include <sys/cpu.h> |
| 103 | |
| 104 | #include <net/if.h> |
| 105 | #include <net/route.h> |
| 106 | #include <net/netisr.h> |
| 107 | #include <net/if_types.h> |
| 108 | #include <net/if_stf.h> |
| 109 | |
| 110 | #include <netinet/in.h> |
| 111 | #include <netinet/in_systm.h> |
| 112 | #include <netinet/ip.h> |
| 113 | #include <netinet/ip_var.h> |
| 114 | #include <netinet/in_var.h> |
| 115 | |
| 116 | #include <netinet/ip6.h> |
| 117 | #include <netinet6/ip6_var.h> |
| 118 | #include <netinet6/in6_var.h> |
| 119 | #include <netinet/ip_ecn.h> |
| 120 | |
| 121 | #include <netinet/ip_encap.h> |
| 122 | |
| 123 | #include <net/net_osdep.h> |
| 124 | |
| 125 | #include <net/bpf.h> |
| 126 | |
| 127 | #include "ioconf.h" |
| 128 | |
| 129 | #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) |
| 130 | #define GET_V4(x) ((const struct in_addr *)(&(x)->s6_addr16[1])) |
| 131 | |
| 132 | struct stf_softc { |
| 133 | struct ifnet sc_if; /* common area */ |
| 134 | struct route sc_ro; |
| 135 | const struct encaptab *encap_cookie; |
| 136 | LIST_ENTRY(stf_softc) sc_list; |
| 137 | }; |
| 138 | |
| 139 | static LIST_HEAD(, stf_softc) stf_softc_list; |
| 140 | |
| 141 | static int stf_clone_create(struct if_clone *, int); |
| 142 | static int stf_clone_destroy(struct ifnet *); |
| 143 | |
| 144 | struct if_clone stf_cloner = |
| 145 | IF_CLONE_INITIALIZER("stf" , stf_clone_create, stf_clone_destroy); |
| 146 | |
| 147 | static int ip_stf_ttl = STF_TTL; |
| 148 | |
| 149 | extern struct domain inetdomain; |
| 150 | |
| 151 | static const struct encapsw in_stf_encapsw = |
| 152 | { |
| 153 | .encapsw4 = { |
| 154 | .pr_input = in_stf_input, |
| 155 | .pr_ctlinput = NULL, |
| 156 | } |
| 157 | }; |
| 158 | |
| 159 | static int stf_encapcheck(struct mbuf *, int, int, void *); |
| 160 | static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); |
| 161 | static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *, |
| 162 | const struct rtentry *); |
| 163 | static int isrfc1918addr(const struct in_addr *); |
| 164 | static int stf_checkaddr4(struct stf_softc *, const struct in_addr *, |
| 165 | struct ifnet *); |
| 166 | static int stf_checkaddr6(struct stf_softc *, const struct in6_addr *, |
| 167 | struct ifnet *); |
| 168 | static void stf_rtrequest(int, struct rtentry *, const struct rt_addrinfo *); |
| 169 | static int stf_ioctl(struct ifnet *, u_long, void *); |
| 170 | |
| 171 | /* ARGSUSED */ |
| 172 | void |
| 173 | stfattach(int count) |
| 174 | { |
| 175 | |
| 176 | /* |
| 177 | * Nothing to do here, initialization is handled by the |
| 178 | * module initialization code in stfinit() below). |
| 179 | */ |
| 180 | } |
| 181 | |
| 182 | static void |
| 183 | stfinit(void) |
| 184 | { |
| 185 | |
| 186 | LIST_INIT(&stf_softc_list); |
| 187 | if_clone_attach(&stf_cloner); |
| 188 | } |
| 189 | |
| 190 | static int |
| 191 | stfdetach(void) |
| 192 | { |
| 193 | int error = 0; |
| 194 | |
| 195 | if (!LIST_EMPTY(&stf_softc_list)) |
| 196 | error = EBUSY; |
| 197 | |
| 198 | if (error == 0) |
| 199 | if_clone_detach(&stf_cloner); |
| 200 | |
| 201 | return error; |
| 202 | } |
| 203 | |
| 204 | static int |
| 205 | stf_clone_create(struct if_clone *ifc, int unit) |
| 206 | { |
| 207 | struct stf_softc *sc; |
| 208 | int error; |
| 209 | |
| 210 | sc = malloc(sizeof(struct stf_softc), M_DEVBUF, M_WAIT|M_ZERO); |
| 211 | if_initname(&sc->sc_if, ifc->ifc_name, unit); |
| 212 | |
| 213 | error = encap_lock_enter(); |
| 214 | if (error) { |
| 215 | free(sc, M_DEVBUF); |
| 216 | return error; |
| 217 | } |
| 218 | |
| 219 | if (LIST_FIRST(&stf_softc_list) != NULL) { |
| 220 | /* Only one stf interface is allowed. */ |
| 221 | encap_lock_exit(); |
| 222 | free(sc, M_DEVBUF); |
| 223 | return (EEXIST); |
| 224 | } |
| 225 | |
| 226 | sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, |
| 227 | stf_encapcheck, &in_stf_encapsw, sc); |
| 228 | encap_lock_exit(); |
| 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 = STF_MTU; |
| 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_attach(&sc->sc_if); |
| 242 | if_alloc_sadl(&sc->sc_if); |
| 243 | bpf_attach(&sc->sc_if, DLT_NULL, sizeof(u_int)); |
| 244 | LIST_INSERT_HEAD(&stf_softc_list, sc, sc_list); |
| 245 | return (0); |
| 246 | } |
| 247 | |
| 248 | static int |
| 249 | stf_clone_destroy(struct ifnet *ifp) |
| 250 | { |
| 251 | struct stf_softc *sc = (void *) ifp; |
| 252 | |
| 253 | encap_lock_enter(); |
| 254 | LIST_REMOVE(sc, sc_list); |
| 255 | encap_detach(sc->encap_cookie); |
| 256 | encap_lock_exit(); |
| 257 | bpf_detach(ifp); |
| 258 | if_detach(ifp); |
| 259 | rtcache_free(&sc->sc_ro); |
| 260 | free(sc, M_DEVBUF); |
| 261 | |
| 262 | return (0); |
| 263 | } |
| 264 | |
| 265 | static int |
| 266 | stf_encapcheck(struct mbuf *m, int off, int proto, void *arg) |
| 267 | { |
| 268 | struct ip ip; |
| 269 | struct in6_ifaddr *ia6; |
| 270 | struct stf_softc *sc; |
| 271 | struct in_addr a, b; |
| 272 | |
| 273 | sc = (struct stf_softc *)arg; |
| 274 | if (sc == NULL) |
| 275 | return 0; |
| 276 | |
| 277 | if ((sc->sc_if.if_flags & IFF_UP) == 0) |
| 278 | return 0; |
| 279 | |
| 280 | /* IFF_LINK0 means "no decapsulation" */ |
| 281 | if ((sc->sc_if.if_flags & IFF_LINK0) != 0) |
| 282 | return 0; |
| 283 | |
| 284 | if (proto != IPPROTO_IPV6) |
| 285 | return 0; |
| 286 | |
| 287 | m_copydata(m, 0, sizeof(ip), (void *)&ip); |
| 288 | |
| 289 | if (ip.ip_v != 4) |
| 290 | return 0; |
| 291 | |
| 292 | ia6 = stf_getsrcifa6(&sc->sc_if); |
| 293 | if (ia6 == NULL) |
| 294 | return 0; |
| 295 | |
| 296 | /* |
| 297 | * check if IPv4 dst matches the IPv4 address derived from the |
| 298 | * local 6to4 address. |
| 299 | * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... |
| 300 | */ |
| 301 | if (memcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst, |
| 302 | sizeof(ip.ip_dst)) != 0) |
| 303 | return 0; |
| 304 | |
| 305 | /* |
| 306 | * check if IPv4 src matches the IPv4 address derived from the |
| 307 | * local 6to4 address masked by prefixmask. |
| 308 | * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 |
| 309 | * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 |
| 310 | */ |
| 311 | memset(&a, 0, sizeof(a)); |
| 312 | a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr; |
| 313 | a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
| 314 | b = ip.ip_src; |
| 315 | b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr; |
| 316 | if (a.s_addr != b.s_addr) |
| 317 | return 0; |
| 318 | |
| 319 | /* stf interface makes single side match only */ |
| 320 | return 32; |
| 321 | } |
| 322 | |
| 323 | static struct in6_ifaddr * |
| 324 | stf_getsrcifa6(struct ifnet *ifp) |
| 325 | { |
| 326 | struct ifaddr *ifa; |
| 327 | struct in_ifaddr *ia4; |
| 328 | struct sockaddr_in6 *sin6; |
| 329 | struct in_addr in; |
| 330 | int s; |
| 331 | |
| 332 | s = pserialize_read_enter(); |
| 333 | IFADDR_READER_FOREACH(ifa, ifp) { |
| 334 | if (ifa->ifa_addr->sa_family != AF_INET6) |
| 335 | continue; |
| 336 | sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; |
| 337 | if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) |
| 338 | continue; |
| 339 | |
| 340 | memcpy(&in, GET_V4(&sin6->sin6_addr), sizeof(in)); |
| 341 | ia4 = in_get_ia(in); |
| 342 | if (ia4 == NULL) |
| 343 | continue; |
| 344 | |
| 345 | pserialize_read_exit(s); |
| 346 | /* TODO NOMPSAFE */ |
| 347 | return (struct in6_ifaddr *)ifa; |
| 348 | } |
| 349 | pserialize_read_exit(s); |
| 350 | |
| 351 | return NULL; |
| 352 | } |
| 353 | |
| 354 | static int |
| 355 | stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, |
| 356 | const struct rtentry *rt0) |
| 357 | { |
| 358 | struct rtentry *rt; |
| 359 | struct stf_softc *sc; |
| 360 | const struct sockaddr_in6 *dst6; |
| 361 | const struct in_addr *in4; |
| 362 | uint8_t tos; |
| 363 | struct ip *ip; |
| 364 | struct ip6_hdr *ip6; |
| 365 | struct in6_ifaddr *ia6; |
| 366 | union { |
| 367 | struct sockaddr dst; |
| 368 | struct sockaddr_in dst4; |
| 369 | } u; |
| 370 | |
| 371 | sc = (struct stf_softc*)ifp; |
| 372 | dst6 = (const struct sockaddr_in6 *)dst; |
| 373 | |
| 374 | /* just in case */ |
| 375 | if ((ifp->if_flags & IFF_UP) == 0) { |
| 376 | m_freem(m); |
| 377 | return ENETDOWN; |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * If we don't have an ip4 address that match my inner ip6 address, |
| 382 | * we shouldn't generate output. Without this check, we'll end up |
| 383 | * using wrong IPv4 source. |
| 384 | */ |
| 385 | ia6 = stf_getsrcifa6(ifp); |
| 386 | if (ia6 == NULL) { |
| 387 | m_freem(m); |
| 388 | ifp->if_oerrors++; |
| 389 | return ENETDOWN; |
| 390 | } |
| 391 | |
| 392 | if (m->m_len < sizeof(*ip6)) { |
| 393 | m = m_pullup(m, sizeof(*ip6)); |
| 394 | if (m == NULL) { |
| 395 | ifp->if_oerrors++; |
| 396 | return ENOBUFS; |
| 397 | } |
| 398 | } |
| 399 | ip6 = mtod(m, struct ip6_hdr *); |
| 400 | tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
| 401 | |
| 402 | /* |
| 403 | * Pickup the right outer dst addr from the list of candidates. |
| 404 | * ip6_dst has priority as it may be able to give us shorter IPv4 hops. |
| 405 | */ |
| 406 | if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst)) |
| 407 | in4 = GET_V4(&ip6->ip6_dst); |
| 408 | else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr)) |
| 409 | in4 = GET_V4(&dst6->sin6_addr); |
| 410 | else { |
| 411 | m_freem(m); |
| 412 | ifp->if_oerrors++; |
| 413 | return ENETUNREACH; |
| 414 | } |
| 415 | |
| 416 | bpf_mtap_af(ifp, AF_INET6, m); |
| 417 | |
| 418 | M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); |
| 419 | if (m && m->m_len < sizeof(struct ip)) |
| 420 | m = m_pullup(m, sizeof(struct ip)); |
| 421 | if (m == NULL) { |
| 422 | ifp->if_oerrors++; |
| 423 | return ENOBUFS; |
| 424 | } |
| 425 | ip = mtod(m, struct ip *); |
| 426 | |
| 427 | memset(ip, 0, sizeof(*ip)); |
| 428 | |
| 429 | bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr), |
| 430 | &ip->ip_src, sizeof(ip->ip_src)); |
| 431 | memcpy(&ip->ip_dst, in4, sizeof(ip->ip_dst)); |
| 432 | ip->ip_p = IPPROTO_IPV6; |
| 433 | ip->ip_ttl = ip_stf_ttl; |
| 434 | ip->ip_len = htons(m->m_pkthdr.len); |
| 435 | if (ifp->if_flags & IFF_LINK1) |
| 436 | ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); |
| 437 | else |
| 438 | ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); |
| 439 | |
| 440 | sockaddr_in_init(&u.dst4, &ip->ip_dst, 0); |
| 441 | if ((rt = rtcache_lookup(&sc->sc_ro, &u.dst)) == NULL) { |
| 442 | m_freem(m); |
| 443 | ifp->if_oerrors++; |
| 444 | return ENETUNREACH; |
| 445 | } |
| 446 | |
| 447 | /* If the route constitutes infinite encapsulation, punt. */ |
| 448 | if (rt->rt_ifp == ifp) { |
| 449 | rtcache_free(&sc->sc_ro); |
| 450 | m_freem(m); |
| 451 | ifp->if_oerrors++; |
| 452 | return ENETUNREACH; |
| 453 | } |
| 454 | |
| 455 | ifp->if_opackets++; |
| 456 | ifp->if_obytes += m->m_pkthdr.len - sizeof(struct ip); |
| 457 | return ip_output(m, NULL, &sc->sc_ro, 0, NULL, NULL); |
| 458 | } |
| 459 | |
| 460 | static int |
| 461 | isrfc1918addr(const struct in_addr *in) |
| 462 | { |
| 463 | /* |
| 464 | * returns 1 if private address range: |
| 465 | * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 |
| 466 | */ |
| 467 | if ((ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || |
| 468 | (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || |
| 469 | (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168) |
| 470 | return 1; |
| 471 | |
| 472 | return 0; |
| 473 | } |
| 474 | |
| 475 | static int |
| 476 | stf_checkaddr4(struct stf_softc *sc, const struct in_addr *in, |
| 477 | struct ifnet *inifp /*incoming interface*/) |
| 478 | { |
| 479 | struct in_ifaddr *ia4; |
| 480 | |
| 481 | /* |
| 482 | * reject packets with the following address: |
| 483 | * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 |
| 484 | */ |
| 485 | if (IN_MULTICAST(in->s_addr)) |
| 486 | return -1; |
| 487 | switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { |
| 488 | case 0: case 127: case 255: |
| 489 | return -1; |
| 490 | } |
| 491 | |
| 492 | /* |
| 493 | * reject packets with private address range. |
| 494 | * (requirement from RFC3056 section 2 1st paragraph) |
| 495 | */ |
| 496 | if (isrfc1918addr(in)) |
| 497 | return -1; |
| 498 | |
| 499 | /* |
| 500 | * reject packet with IPv4 link-local (169.254.0.0/16), |
| 501 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
| 502 | */ |
| 503 | if (((ntohl(in->s_addr) & 0xff000000) >> 24) == 169 && |
| 504 | ((ntohl(in->s_addr) & 0x00ff0000) >> 16) == 254) |
| 505 | return -1; |
| 506 | |
| 507 | /* |
| 508 | * reject packets with broadcast |
| 509 | */ |
| 510 | IN_ADDRLIST_READER_FOREACH(ia4) { |
| 511 | if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) |
| 512 | continue; |
| 513 | if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) |
| 514 | return -1; |
| 515 | } |
| 516 | |
| 517 | /* |
| 518 | * perform ingress filter |
| 519 | */ |
| 520 | if (sc && (sc->sc_if.if_flags & IFF_LINK2) == 0 && inifp) { |
| 521 | struct sockaddr_in sin; |
| 522 | struct rtentry *rt; |
| 523 | |
| 524 | memset(&sin, 0, sizeof(sin)); |
| 525 | sin.sin_family = AF_INET; |
| 526 | sin.sin_len = sizeof(struct sockaddr_in); |
| 527 | sin.sin_addr = *in; |
| 528 | rt = rtalloc1((struct sockaddr *)&sin, 0); |
| 529 | if (!rt || rt->rt_ifp != inifp) { |
| 530 | #if 0 |
| 531 | log(LOG_WARNING, "%s: packet from 0x%x dropped " |
| 532 | "due to ingress filter\n" , if_name(&sc->sc_if), |
| 533 | (uint32_t)ntohl(sin.sin_addr.s_addr)); |
| 534 | #endif |
| 535 | if (rt) |
| 536 | rtfree(rt); |
| 537 | return -1; |
| 538 | } |
| 539 | rtfree(rt); |
| 540 | } |
| 541 | |
| 542 | return 0; |
| 543 | } |
| 544 | |
| 545 | static int |
| 546 | stf_checkaddr6(struct stf_softc *sc, const struct in6_addr *in6, |
| 547 | struct ifnet *inifp /*incoming interface*/) |
| 548 | { |
| 549 | |
| 550 | /* |
| 551 | * check 6to4 addresses |
| 552 | */ |
| 553 | if (IN6_IS_ADDR_6TO4(in6)) |
| 554 | return stf_checkaddr4(sc, GET_V4(in6), inifp); |
| 555 | |
| 556 | /* |
| 557 | * reject anything that look suspicious. the test is implemented |
| 558 | * in ip6_input too, but we check here as well to |
| 559 | * (1) reject bad packets earlier, and |
| 560 | * (2) to be safe against future ip6_input change. |
| 561 | */ |
| 562 | if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6)) |
| 563 | return -1; |
| 564 | |
| 565 | /* |
| 566 | * reject link-local and site-local unicast |
| 567 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
| 568 | */ |
| 569 | if (IN6_IS_ADDR_LINKLOCAL(in6) || IN6_IS_ADDR_SITELOCAL(in6)) |
| 570 | return -1; |
| 571 | |
| 572 | /* |
| 573 | * reject node-local and link-local multicast |
| 574 | * as suggested in draft-savola-v6ops-6to4-security-00.txt |
| 575 | */ |
| 576 | if (IN6_IS_ADDR_MC_NODELOCAL(in6) || IN6_IS_ADDR_MC_LINKLOCAL(in6)) |
| 577 | return -1; |
| 578 | |
| 579 | return 0; |
| 580 | } |
| 581 | |
| 582 | void |
| 583 | in_stf_input(struct mbuf *m, int off, int proto) |
| 584 | { |
| 585 | int s; |
| 586 | struct stf_softc *sc; |
| 587 | struct ip *ip; |
| 588 | struct ip6_hdr *ip6; |
| 589 | uint8_t otos, itos; |
| 590 | struct ifnet *ifp; |
| 591 | size_t pktlen; |
| 592 | |
| 593 | if (proto != IPPROTO_IPV6) { |
| 594 | m_freem(m); |
| 595 | return; |
| 596 | } |
| 597 | |
| 598 | ip = mtod(m, struct ip *); |
| 599 | |
| 600 | sc = (struct stf_softc *)encap_getarg(m); |
| 601 | |
| 602 | if (sc == NULL || (sc->sc_if.if_flags & IFF_UP) == 0) { |
| 603 | m_freem(m); |
| 604 | return; |
| 605 | } |
| 606 | |
| 607 | ifp = &sc->sc_if; |
| 608 | |
| 609 | /* |
| 610 | * perform sanity check against outer src/dst. |
| 611 | * for source, perform ingress filter as well. |
| 612 | */ |
| 613 | if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 || |
| 614 | stf_checkaddr4(sc, &ip->ip_src, m_get_rcvif_NOMPSAFE(m)) < 0) { |
| 615 | m_freem(m); |
| 616 | return; |
| 617 | } |
| 618 | |
| 619 | otos = ip->ip_tos; |
| 620 | m_adj(m, off); |
| 621 | |
| 622 | if (m->m_len < sizeof(*ip6)) { |
| 623 | m = m_pullup(m, sizeof(*ip6)); |
| 624 | if (!m) |
| 625 | return; |
| 626 | } |
| 627 | ip6 = mtod(m, struct ip6_hdr *); |
| 628 | |
| 629 | /* |
| 630 | * perform sanity check against inner src/dst. |
| 631 | * for source, perform ingress filter as well. |
| 632 | */ |
| 633 | if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || |
| 634 | stf_checkaddr6(sc, &ip6->ip6_src, m_get_rcvif_NOMPSAFE(m)) < 0) { |
| 635 | m_freem(m); |
| 636 | return; |
| 637 | } |
| 638 | |
| 639 | itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
| 640 | if ((ifp->if_flags & IFF_LINK1) != 0) |
| 641 | ip_ecn_egress(ECN_ALLOWED, &otos, &itos); |
| 642 | else |
| 643 | ip_ecn_egress(ECN_NOCARE, &otos, &itos); |
| 644 | ip6->ip6_flow &= ~htonl(0xff << 20); |
| 645 | ip6->ip6_flow |= htonl((uint32_t)itos << 20); |
| 646 | |
| 647 | pktlen = m->m_pkthdr.len; |
| 648 | m_set_rcvif(m, ifp); |
| 649 | |
| 650 | bpf_mtap_af(ifp, AF_INET6, m); |
| 651 | |
| 652 | /* |
| 653 | * Put the packet to the network layer input queue according to the |
| 654 | * specified address family. |
| 655 | * See net/if_gif.c for possible issues with packet processing |
| 656 | * reorder due to extra queueing. |
| 657 | */ |
| 658 | |
| 659 | s = splnet(); |
| 660 | if (__predict_true(pktq_enqueue(ip6_pktq, m, 0))) { |
| 661 | ifp->if_ipackets++; |
| 662 | ifp->if_ibytes += pktlen; |
| 663 | } else { |
| 664 | m_freem(m); |
| 665 | } |
| 666 | splx(s); |
| 667 | |
| 668 | return; |
| 669 | } |
| 670 | |
| 671 | /* ARGSUSED */ |
| 672 | static void |
| 673 | stf_rtrequest(int cmd, struct rtentry *rt, |
| 674 | const struct rt_addrinfo *info) |
| 675 | { |
| 676 | if (rt != NULL) { |
| 677 | struct stf_softc *sc; |
| 678 | |
| 679 | sc = LIST_FIRST(&stf_softc_list); |
| 680 | rt->rt_rmx.rmx_mtu = (sc != NULL) ? sc->sc_if.if_mtu : STF_MTU; |
| 681 | } |
| 682 | } |
| 683 | |
| 684 | static int |
| 685 | stf_ioctl(struct ifnet *ifp, u_long cmd, void *data) |
| 686 | { |
| 687 | struct ifaddr *ifa; |
| 688 | struct ifreq *ifr = data; |
| 689 | struct sockaddr_in6 *sin6; |
| 690 | int error; |
| 691 | |
| 692 | error = 0; |
| 693 | switch (cmd) { |
| 694 | case SIOCINITIFADDR: |
| 695 | ifa = (struct ifaddr *)data; |
| 696 | if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { |
| 697 | error = EAFNOSUPPORT; |
| 698 | break; |
| 699 | } |
| 700 | sin6 = (struct sockaddr_in6 *)ifa->ifa_addr; |
| 701 | if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr) && |
| 702 | !isrfc1918addr(GET_V4(&sin6->sin6_addr))) { |
| 703 | ifa->ifa_rtrequest = stf_rtrequest; |
| 704 | ifp->if_flags |= IFF_UP; |
| 705 | } else |
| 706 | error = EINVAL; |
| 707 | break; |
| 708 | |
| 709 | case SIOCADDMULTI: |
| 710 | case SIOCDELMULTI: |
| 711 | if (ifr != NULL && |
| 712 | ifreq_getaddr(cmd, ifr)->sa_family == AF_INET6) |
| 713 | ; |
| 714 | else |
| 715 | error = EAFNOSUPPORT; |
| 716 | break; |
| 717 | |
| 718 | case SIOCSIFMTU: |
| 719 | if (ifr->ifr_mtu < STF_MTU_MIN || ifr->ifr_mtu > STF_MTU_MAX) |
| 720 | return EINVAL; |
| 721 | else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) |
| 722 | error = 0; |
| 723 | break; |
| 724 | |
| 725 | default: |
| 726 | error = ifioctl_common(ifp, cmd, data); |
| 727 | break; |
| 728 | } |
| 729 | |
| 730 | return error; |
| 731 | } |
| 732 | |
| 733 | /* |
| 734 | * Module infrastructure |
| 735 | */ |
| 736 | #include "if_module.h" |
| 737 | |
| 738 | IF_MODULE(MODULE_CLASS_DRIVER, stf, "" ) |
| 739 | |