| 1 | /* $NetBSD: in6_gif.c,v 1.79 2016/07/15 07:40:09 ozaki-r Exp $ */ |
| 2 | /* $KAME: in6_gif.c,v 1.62 2001/07/29 04:27:25 itojun Exp $ */ |
| 3 | |
| 4 | /* |
| 5 | * Copyright (C) 1995, 1996, 1997, and 1998 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 | #include <sys/cdefs.h> |
| 34 | __KERNEL_RCSID(0, "$NetBSD: in6_gif.c,v 1.79 2016/07/15 07:40:09 ozaki-r Exp $" ); |
| 35 | |
| 36 | #ifdef _KERNEL_OPT |
| 37 | #include "opt_inet.h" |
| 38 | #endif |
| 39 | |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/systm.h> |
| 42 | #include <sys/socket.h> |
| 43 | #include <sys/sockio.h> |
| 44 | #include <sys/mbuf.h> |
| 45 | #include <sys/errno.h> |
| 46 | #include <sys/ioctl.h> |
| 47 | #include <sys/queue.h> |
| 48 | #include <sys/syslog.h> |
| 49 | #include <sys/kernel.h> |
| 50 | |
| 51 | #include <net/if.h> |
| 52 | #include <net/route.h> |
| 53 | |
| 54 | #include <netinet/in.h> |
| 55 | #include <netinet/in_systm.h> |
| 56 | #ifdef INET |
| 57 | #include <netinet/ip.h> |
| 58 | #endif |
| 59 | #include <netinet/ip_encap.h> |
| 60 | #ifdef INET6 |
| 61 | #include <netinet/ip6.h> |
| 62 | #include <netinet6/ip6_var.h> |
| 63 | #include <netinet6/ip6_private.h> |
| 64 | #include <netinet6/in6_gif.h> |
| 65 | #include <netinet6/in6_var.h> |
| 66 | #endif |
| 67 | #include <netinet6/ip6protosw.h> /* for struct ip6ctlparam */ |
| 68 | #include <netinet/ip_ecn.h> |
| 69 | |
| 70 | #include <net/if_gif.h> |
| 71 | |
| 72 | #include <net/net_osdep.h> |
| 73 | |
| 74 | static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, |
| 75 | struct ifnet *); |
| 76 | |
| 77 | int ip6_gif_hlim = GIF_HLIM; |
| 78 | |
| 79 | static const struct encapsw in6_gif_encapsw; |
| 80 | |
| 81 | /* |
| 82 | * family - family of the packet to be encapsulate. |
| 83 | */ |
| 84 | |
| 85 | int |
| 86 | in6_gif_output(struct ifnet *ifp, int family, struct mbuf *m) |
| 87 | { |
| 88 | struct rtentry *rt; |
| 89 | struct gif_softc *sc = ifp->if_softc; |
| 90 | struct sockaddr_in6 *sin6_src = satosin6(sc->gif_psrc); |
| 91 | struct sockaddr_in6 *sin6_dst = satosin6(sc->gif_pdst); |
| 92 | struct ip6_hdr *ip6; |
| 93 | int proto, error; |
| 94 | u_int8_t itos, otos; |
| 95 | union { |
| 96 | struct sockaddr dst; |
| 97 | struct sockaddr_in6 dst6; |
| 98 | } u; |
| 99 | |
| 100 | if (sin6_src == NULL || sin6_dst == NULL || |
| 101 | sin6_src->sin6_family != AF_INET6 || |
| 102 | sin6_dst->sin6_family != AF_INET6) { |
| 103 | m_freem(m); |
| 104 | return EAFNOSUPPORT; |
| 105 | } |
| 106 | |
| 107 | switch (family) { |
| 108 | #ifdef INET |
| 109 | case AF_INET: |
| 110 | { |
| 111 | struct ip *ip; |
| 112 | |
| 113 | proto = IPPROTO_IPV4; |
| 114 | if (m->m_len < sizeof(*ip)) { |
| 115 | m = m_pullup(m, sizeof(*ip)); |
| 116 | if (!m) |
| 117 | return ENOBUFS; |
| 118 | } |
| 119 | ip = mtod(m, struct ip *); |
| 120 | itos = ip->ip_tos; |
| 121 | break; |
| 122 | } |
| 123 | #endif |
| 124 | #ifdef INET6 |
| 125 | case AF_INET6: |
| 126 | { |
| 127 | proto = IPPROTO_IPV6; |
| 128 | if (m->m_len < sizeof(*ip6)) { |
| 129 | m = m_pullup(m, sizeof(*ip6)); |
| 130 | if (!m) |
| 131 | return ENOBUFS; |
| 132 | } |
| 133 | ip6 = mtod(m, struct ip6_hdr *); |
| 134 | itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
| 135 | break; |
| 136 | } |
| 137 | #endif |
| 138 | default: |
| 139 | #ifdef DEBUG |
| 140 | printf("in6_gif_output: warning: unknown family %d passed\n" , |
| 141 | family); |
| 142 | #endif |
| 143 | m_freem(m); |
| 144 | return EAFNOSUPPORT; |
| 145 | } |
| 146 | |
| 147 | /* prepend new IP header */ |
| 148 | M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); |
| 149 | if (m && m->m_len < sizeof(struct ip6_hdr)) |
| 150 | m = m_pullup(m, sizeof(struct ip6_hdr)); |
| 151 | if (m == NULL) |
| 152 | return ENOBUFS; |
| 153 | |
| 154 | ip6 = mtod(m, struct ip6_hdr *); |
| 155 | ip6->ip6_flow = 0; |
| 156 | ip6->ip6_vfc &= ~IPV6_VERSION_MASK; |
| 157 | ip6->ip6_vfc |= IPV6_VERSION; |
| 158 | #if 0 /* ip6->ip6_plen will be filled by ip6_output */ |
| 159 | ip6->ip6_plen = htons((u_int16_t)m->m_pkthdr.len); |
| 160 | #endif |
| 161 | ip6->ip6_nxt = proto; |
| 162 | ip6->ip6_hlim = ip6_gif_hlim; |
| 163 | ip6->ip6_src = sin6_src->sin6_addr; |
| 164 | /* bidirectional configured tunnel mode */ |
| 165 | if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) |
| 166 | ip6->ip6_dst = sin6_dst->sin6_addr; |
| 167 | else { |
| 168 | m_freem(m); |
| 169 | return ENETUNREACH; |
| 170 | } |
| 171 | if (ifp->if_flags & IFF_LINK1) |
| 172 | ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); |
| 173 | else |
| 174 | ip_ecn_ingress(ECN_NOCARE, &otos, &itos); |
| 175 | ip6->ip6_flow &= ~ntohl(0xff00000); |
| 176 | ip6->ip6_flow |= htonl((u_int32_t)otos << 20); |
| 177 | |
| 178 | sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0); |
| 179 | if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) { |
| 180 | m_freem(m); |
| 181 | return ENETUNREACH; |
| 182 | } |
| 183 | |
| 184 | /* If the route constitutes infinite encapsulation, punt. */ |
| 185 | if (rt->rt_ifp == ifp) { |
| 186 | rtcache_free(&sc->gif_ro); |
| 187 | m_freem(m); |
| 188 | return ENETUNREACH; /* XXX */ |
| 189 | } |
| 190 | |
| 191 | #ifdef IPV6_MINMTU |
| 192 | /* |
| 193 | * force fragmentation to minimum MTU, to avoid path MTU discovery. |
| 194 | * it is too painful to ask for resend of inner packet, to achieve |
| 195 | * path MTU discovery for encapsulated packets. |
| 196 | */ |
| 197 | error = ip6_output(m, 0, &sc->gif_ro, IPV6_MINMTU, NULL, NULL, NULL); |
| 198 | #else |
| 199 | error = ip6_output(m, 0, &sc->gif_ro, 0, NULL, NULL, NULL); |
| 200 | #endif |
| 201 | |
| 202 | return (error); |
| 203 | } |
| 204 | |
| 205 | int |
| 206 | in6_gif_input(struct mbuf **mp, int *offp, int proto) |
| 207 | { |
| 208 | struct mbuf *m = *mp; |
| 209 | struct ifnet *gifp = NULL; |
| 210 | struct ip6_hdr *ip6; |
| 211 | int af = 0; |
| 212 | u_int32_t otos; |
| 213 | |
| 214 | ip6 = mtod(m, struct ip6_hdr *); |
| 215 | |
| 216 | gifp = (struct ifnet *)encap_getarg(m); |
| 217 | |
| 218 | if (gifp == NULL || (gifp->if_flags & (IFF_UP|IFF_RUNNING)) |
| 219 | != (IFF_UP|IFF_RUNNING)) { |
| 220 | m_freem(m); |
| 221 | IP6_STATINC(IP6_STAT_NOGIF); |
| 222 | return IPPROTO_DONE; |
| 223 | } |
| 224 | #ifndef GIF_ENCAPCHECK |
| 225 | struct gif_softc *sc = (struct gif_softc *)gifp->if_softc; |
| 226 | /* other CPU do delete_tunnel */ |
| 227 | if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { |
| 228 | m_freem(m); |
| 229 | IP6_STATINC(IP6_STAT_NOGIF); |
| 230 | return IPPROTO_DONE; |
| 231 | } |
| 232 | |
| 233 | struct psref psref; |
| 234 | struct ifnet *rcvif = m_get_rcvif_psref(m, &psref); |
| 235 | if (rcvif == NULL || !gif_validate6(ip6, sc, rcvif)) { |
| 236 | m_put_rcvif_psref(rcvif, &psref); |
| 237 | m_freem(m); |
| 238 | IP6_STATINC(IP6_STAT_NOGIF); |
| 239 | return IPPROTO_DONE; |
| 240 | } |
| 241 | m_put_rcvif_psref(rcvif, &psref); |
| 242 | #endif |
| 243 | |
| 244 | otos = ip6->ip6_flow; |
| 245 | m_adj(m, *offp); |
| 246 | |
| 247 | switch (proto) { |
| 248 | #ifdef INET |
| 249 | case IPPROTO_IPV4: |
| 250 | { |
| 251 | struct ip *ip; |
| 252 | u_int8_t otos8; |
| 253 | af = AF_INET; |
| 254 | otos8 = (ntohl(otos) >> 20) & 0xff; |
| 255 | if (m->m_len < sizeof(*ip)) { |
| 256 | m = m_pullup(m, sizeof(*ip)); |
| 257 | if (!m) |
| 258 | return IPPROTO_DONE; |
| 259 | } |
| 260 | ip = mtod(m, struct ip *); |
| 261 | if (gifp->if_flags & IFF_LINK1) |
| 262 | ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos); |
| 263 | else |
| 264 | ip_ecn_egress(ECN_NOCARE, &otos8, &ip->ip_tos); |
| 265 | break; |
| 266 | } |
| 267 | #endif /* INET */ |
| 268 | #ifdef INET6 |
| 269 | case IPPROTO_IPV6: |
| 270 | { |
| 271 | struct ip6_hdr *ip6x; |
| 272 | af = AF_INET6; |
| 273 | if (m->m_len < sizeof(*ip6x)) { |
| 274 | m = m_pullup(m, sizeof(*ip6x)); |
| 275 | if (!m) |
| 276 | return IPPROTO_DONE; |
| 277 | } |
| 278 | ip6x = mtod(m, struct ip6_hdr *); |
| 279 | if (gifp->if_flags & IFF_LINK1) |
| 280 | ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6x->ip6_flow); |
| 281 | else |
| 282 | ip6_ecn_egress(ECN_NOCARE, &otos, &ip6x->ip6_flow); |
| 283 | break; |
| 284 | } |
| 285 | #endif |
| 286 | default: |
| 287 | IP6_STATINC(IP6_STAT_NOGIF); |
| 288 | m_freem(m); |
| 289 | return IPPROTO_DONE; |
| 290 | } |
| 291 | |
| 292 | gif_input(m, af, gifp); |
| 293 | return IPPROTO_DONE; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * validate outer address. |
| 298 | */ |
| 299 | static int |
| 300 | gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, |
| 301 | struct ifnet *ifp) |
| 302 | { |
| 303 | const struct sockaddr_in6 *src, *dst; |
| 304 | |
| 305 | src = satosin6(sc->gif_psrc); |
| 306 | dst = satosin6(sc->gif_pdst); |
| 307 | |
| 308 | /* check for address match */ |
| 309 | if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || |
| 310 | !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) |
| 311 | return 0; |
| 312 | |
| 313 | /* martian filters on outer source - done in ip6_input */ |
| 314 | |
| 315 | /* ingress filters on outer source */ |
| 316 | if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { |
| 317 | union { |
| 318 | struct sockaddr sa; |
| 319 | struct sockaddr_in6 sin6; |
| 320 | } u; |
| 321 | struct rtentry *rt; |
| 322 | |
| 323 | /* XXX scopeid */ |
| 324 | sockaddr_in6_init(&u.sin6, &ip6->ip6_src, 0, 0, 0); |
| 325 | rt = rtalloc1(&u.sa, 0); |
| 326 | if (rt == NULL || rt->rt_ifp != ifp) { |
| 327 | #if 0 |
| 328 | log(LOG_WARNING, "%s: packet from %s dropped " |
| 329 | "due to ingress filter\n" , if_name(&sc->gif_if), |
| 330 | ip6_sprintf(&u.sin6.sin6_addr)); |
| 331 | #endif |
| 332 | if (rt != NULL) |
| 333 | rtfree(rt); |
| 334 | return 0; |
| 335 | } |
| 336 | rtfree(rt); |
| 337 | } |
| 338 | |
| 339 | return 128 * 2; |
| 340 | } |
| 341 | |
| 342 | #ifdef GIF_ENCAPCHECK |
| 343 | /* |
| 344 | * we know that we are in IFF_UP, outer address available, and outer family |
| 345 | * matched the physical addr family. see gif_encapcheck(). |
| 346 | */ |
| 347 | int |
| 348 | gif_encapcheck6(struct mbuf *m, int off, int proto, void *arg) |
| 349 | { |
| 350 | struct ip6_hdr ip6; |
| 351 | struct gif_softc *sc; |
| 352 | struct ifnet *ifp = NULL; |
| 353 | int r; |
| 354 | struct psref psref; |
| 355 | |
| 356 | /* sanity check done in caller */ |
| 357 | sc = arg; |
| 358 | |
| 359 | m_copydata(m, 0, sizeof(ip6), (void *)&ip6); |
| 360 | if ((m->m_flags & M_PKTHDR) != 0) |
| 361 | ifp = m_get_rcvif_psref(m, &psref); |
| 362 | |
| 363 | r = gif_validate6(&ip6, sc, ifp); |
| 364 | |
| 365 | m_put_rcvif_psref(ifp, &psref); |
| 366 | return r; |
| 367 | } |
| 368 | #endif |
| 369 | |
| 370 | int |
| 371 | in6_gif_attach(struct gif_softc *sc) |
| 372 | { |
| 373 | #ifndef GIF_ENCAPCHECK |
| 374 | struct sockaddr_in6 mask6; |
| 375 | |
| 376 | memset(&mask6, 0, sizeof(mask6)); |
| 377 | mask6.sin6_len = sizeof(struct sockaddr_in6); |
| 378 | mask6.sin6_addr.s6_addr32[0] = mask6.sin6_addr.s6_addr32[1] = |
| 379 | mask6.sin6_addr.s6_addr32[2] = mask6.sin6_addr.s6_addr32[3] = ~0; |
| 380 | |
| 381 | if (!sc->gif_psrc || !sc->gif_pdst) |
| 382 | return EINVAL; |
| 383 | sc->encap_cookie6 = encap_attach(AF_INET6, -1, sc->gif_psrc, |
| 384 | sin6tosa(&mask6), sc->gif_pdst, sin6tosa(&mask6), |
| 385 | (const void *)&in6_gif_encapsw, sc); |
| 386 | #else |
| 387 | sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, |
| 388 | &in6_gif_encapsw, sc); |
| 389 | #endif |
| 390 | if (sc->encap_cookie6 == NULL) |
| 391 | return EEXIST; |
| 392 | return 0; |
| 393 | } |
| 394 | |
| 395 | int |
| 396 | in6_gif_detach(struct gif_softc *sc) |
| 397 | { |
| 398 | int error; |
| 399 | |
| 400 | error = in6_gif_pause(sc); |
| 401 | |
| 402 | rtcache_free(&sc->gif_ro); |
| 403 | |
| 404 | return error; |
| 405 | } |
| 406 | |
| 407 | int |
| 408 | in6_gif_pause(struct gif_softc *sc) |
| 409 | { |
| 410 | int error; |
| 411 | |
| 412 | error = encap_detach(sc->encap_cookie6); |
| 413 | if (error == 0) |
| 414 | sc->encap_cookie6 = NULL; |
| 415 | |
| 416 | return error; |
| 417 | } |
| 418 | |
| 419 | void * |
| 420 | in6_gif_ctlinput(int cmd, const struct sockaddr *sa, void *d, void *eparg) |
| 421 | { |
| 422 | struct gif_softc *sc = eparg; |
| 423 | struct ip6ctlparam *ip6cp = NULL; |
| 424 | struct ip6_hdr *ip6; |
| 425 | const struct sockaddr_in6 *dst6; |
| 426 | |
| 427 | if (sa->sa_family != AF_INET6 || |
| 428 | sa->sa_len != sizeof(struct sockaddr_in6)) |
| 429 | return NULL; |
| 430 | |
| 431 | if ((unsigned)cmd >= PRC_NCMDS) |
| 432 | return NULL; |
| 433 | if (cmd == PRC_HOSTDEAD) |
| 434 | d = NULL; |
| 435 | else if (inet6ctlerrmap[cmd] == 0) |
| 436 | return NULL; |
| 437 | |
| 438 | /* if the parameter is from icmp6, decode it. */ |
| 439 | if (d != NULL) { |
| 440 | ip6cp = (struct ip6ctlparam *)d; |
| 441 | ip6 = ip6cp->ip6c_ip6; |
| 442 | } else { |
| 443 | ip6 = NULL; |
| 444 | } |
| 445 | |
| 446 | if (!ip6) |
| 447 | return NULL; |
| 448 | |
| 449 | if ((sc->gif_if.if_flags & IFF_RUNNING) == 0) |
| 450 | return NULL; |
| 451 | if (sc->gif_psrc->sa_family != AF_INET6) |
| 452 | return NULL; |
| 453 | |
| 454 | dst6 = satocsin6(rtcache_getdst(&sc->gif_ro)); |
| 455 | /* XXX scope */ |
| 456 | if (dst6 == NULL) |
| 457 | ; |
| 458 | else if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst6->sin6_addr)) |
| 459 | rtcache_free(&sc->gif_ro); |
| 460 | |
| 461 | return NULL; |
| 462 | } |
| 463 | |
| 464 | ENCAP_PR_WRAP_CTLINPUT(in6_gif_ctlinput) |
| 465 | #define in6_gif_ctlinput in6_gif_ctlinput_wrapper |
| 466 | |
| 467 | static const struct encapsw in6_gif_encapsw = { |
| 468 | .encapsw6 = { |
| 469 | .pr_input = in6_gif_input, |
| 470 | .pr_ctlinput = in6_gif_ctlinput, |
| 471 | } |
| 472 | }; |
| 473 | |