| 1 | /* $NetBSD: in_gif.c,v 1.83 2016/08/18 11:34:09 knakahara Exp $ */ |
| 2 | /* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 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: in_gif.c,v 1.83 2016/08/18 11:34:09 knakahara 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/syslog.h> |
| 48 | #include <sys/kernel.h> |
| 49 | |
| 50 | #include <net/if.h> |
| 51 | #include <net/route.h> |
| 52 | |
| 53 | #include <netinet/in.h> |
| 54 | #include <netinet/in_systm.h> |
| 55 | #include <netinet/ip.h> |
| 56 | #include <netinet/ip_var.h> |
| 57 | #include <netinet/in_gif.h> |
| 58 | #include <netinet/in_var.h> |
| 59 | #include <netinet/ip_encap.h> |
| 60 | #include <netinet/ip_ecn.h> |
| 61 | |
| 62 | #ifdef INET6 |
| 63 | #include <netinet/ip6.h> |
| 64 | #endif |
| 65 | |
| 66 | #include <net/if_gif.h> |
| 67 | |
| 68 | #include <net/net_osdep.h> |
| 69 | |
| 70 | static int gif_validate4(const struct ip *, struct gif_softc *, |
| 71 | struct ifnet *); |
| 72 | |
| 73 | int ip_gif_ttl = GIF_TTL; |
| 74 | |
| 75 | static const struct encapsw in_gif_encapsw = { |
| 76 | .encapsw4 = { |
| 77 | .pr_input = in_gif_input, |
| 78 | .pr_ctlinput = NULL, |
| 79 | } |
| 80 | }; |
| 81 | |
| 82 | int |
| 83 | in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) |
| 84 | { |
| 85 | struct rtentry *rt; |
| 86 | struct gif_softc *sc = ifp->if_softc; |
| 87 | struct sockaddr_in *sin_src = satosin(sc->gif_psrc); |
| 88 | struct sockaddr_in *sin_dst = satosin(sc->gif_pdst); |
| 89 | struct ip iphdr; /* capsule IP header, host byte ordered */ |
| 90 | int proto, error; |
| 91 | u_int8_t tos; |
| 92 | union { |
| 93 | struct sockaddr dst; |
| 94 | struct sockaddr_in dst4; |
| 95 | } u; |
| 96 | |
| 97 | if (sin_src == NULL || sin_dst == NULL || |
| 98 | sin_src->sin_family != AF_INET || |
| 99 | sin_dst->sin_family != AF_INET) { |
| 100 | m_freem(m); |
| 101 | return EAFNOSUPPORT; |
| 102 | } |
| 103 | |
| 104 | switch (family) { |
| 105 | #ifdef INET |
| 106 | case AF_INET: |
| 107 | { |
| 108 | const struct ip *ip; |
| 109 | |
| 110 | proto = IPPROTO_IPV4; |
| 111 | if (m->m_len < sizeof(*ip)) { |
| 112 | m = m_pullup(m, sizeof(*ip)); |
| 113 | if (m == NULL) |
| 114 | return ENOBUFS; |
| 115 | } |
| 116 | ip = mtod(m, const struct ip *); |
| 117 | tos = ip->ip_tos; |
| 118 | break; |
| 119 | } |
| 120 | #endif /* INET */ |
| 121 | #ifdef INET6 |
| 122 | case AF_INET6: |
| 123 | { |
| 124 | const struct ip6_hdr *ip6; |
| 125 | proto = IPPROTO_IPV6; |
| 126 | if (m->m_len < sizeof(*ip6)) { |
| 127 | m = m_pullup(m, sizeof(*ip6)); |
| 128 | if (m == NULL) |
| 129 | return ENOBUFS; |
| 130 | } |
| 131 | ip6 = mtod(m, const struct ip6_hdr *); |
| 132 | tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
| 133 | break; |
| 134 | } |
| 135 | #endif /* INET6 */ |
| 136 | default: |
| 137 | #ifdef DEBUG |
| 138 | printf("in_gif_output: warning: unknown family %d passed\n" , |
| 139 | family); |
| 140 | #endif |
| 141 | m_freem(m); |
| 142 | return EAFNOSUPPORT; |
| 143 | } |
| 144 | |
| 145 | memset(&iphdr, 0, sizeof(iphdr)); |
| 146 | iphdr.ip_src = sin_src->sin_addr; |
| 147 | /* bidirectional configured tunnel mode */ |
| 148 | if (sin_dst->sin_addr.s_addr != INADDR_ANY) |
| 149 | iphdr.ip_dst = sin_dst->sin_addr; |
| 150 | else { |
| 151 | m_freem(m); |
| 152 | return ENETUNREACH; |
| 153 | } |
| 154 | iphdr.ip_p = proto; |
| 155 | /* version will be set in ip_output() */ |
| 156 | iphdr.ip_ttl = ip_gif_ttl; |
| 157 | iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); |
| 158 | if (ifp->if_flags & IFF_LINK1) |
| 159 | ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); |
| 160 | else |
| 161 | ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); |
| 162 | |
| 163 | /* prepend new IP header */ |
| 164 | M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); |
| 165 | /* XXX Is m_pullup really necessary after M_PREPEND? */ |
| 166 | if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) |
| 167 | m = m_pullup(m, sizeof(struct ip)); |
| 168 | if (m == NULL) |
| 169 | return ENOBUFS; |
| 170 | bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); |
| 171 | |
| 172 | sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0); |
| 173 | if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) { |
| 174 | m_freem(m); |
| 175 | return ENETUNREACH; |
| 176 | } |
| 177 | |
| 178 | /* If the route constitutes infinite encapsulation, punt. */ |
| 179 | if (rt->rt_ifp == ifp) { |
| 180 | rtcache_free(&sc->gif_ro); |
| 181 | m_freem(m); |
| 182 | return ENETUNREACH; /*XXX*/ |
| 183 | } |
| 184 | |
| 185 | error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); |
| 186 | return (error); |
| 187 | } |
| 188 | |
| 189 | void |
| 190 | in_gif_input(struct mbuf *m, int off, int proto) |
| 191 | { |
| 192 | struct ifnet *gifp = NULL; |
| 193 | const struct ip *ip; |
| 194 | int af; |
| 195 | u_int8_t otos; |
| 196 | |
| 197 | ip = mtod(m, const struct ip *); |
| 198 | |
| 199 | gifp = (struct ifnet *)encap_getarg(m); |
| 200 | |
| 201 | if (gifp == NULL || (gifp->if_flags & (IFF_UP|IFF_RUNNING)) |
| 202 | != (IFF_UP|IFF_RUNNING)) { |
| 203 | m_freem(m); |
| 204 | ip_statinc(IP_STAT_NOGIF); |
| 205 | return; |
| 206 | } |
| 207 | #ifndef GIF_ENCAPCHECK |
| 208 | struct gif_softc *sc = (struct gif_softc *)gifp->if_softc; |
| 209 | /* other CPU do delete_tunnel */ |
| 210 | if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { |
| 211 | m_freem(m); |
| 212 | ip_statinc(IP_STAT_NOGIF); |
| 213 | return; |
| 214 | } |
| 215 | |
| 216 | struct ifnet *rcvif; |
| 217 | struct psref psref; |
| 218 | rcvif = m_get_rcvif_psref(m, &psref); |
| 219 | if (!gif_validate4(ip, sc, rcvif)) { |
| 220 | m_put_rcvif_psref(rcvif, &psref); |
| 221 | m_freem(m); |
| 222 | ip_statinc(IP_STAT_NOGIF); |
| 223 | return; |
| 224 | } |
| 225 | m_put_rcvif_psref(rcvif, &psref); |
| 226 | #endif |
| 227 | otos = ip->ip_tos; |
| 228 | m_adj(m, off); |
| 229 | |
| 230 | switch (proto) { |
| 231 | #ifdef INET |
| 232 | case IPPROTO_IPV4: |
| 233 | { |
| 234 | struct ip *xip; |
| 235 | af = AF_INET; |
| 236 | if (M_UNWRITABLE(m, sizeof(*xip))) { |
| 237 | if ((m = m_pullup(m, sizeof(*xip))) == NULL) |
| 238 | return; |
| 239 | } |
| 240 | xip = mtod(m, struct ip *); |
| 241 | if (gifp->if_flags & IFF_LINK1) |
| 242 | ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); |
| 243 | else |
| 244 | ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); |
| 245 | break; |
| 246 | } |
| 247 | #endif |
| 248 | #ifdef INET6 |
| 249 | case IPPROTO_IPV6: |
| 250 | { |
| 251 | struct ip6_hdr *ip6; |
| 252 | u_int8_t itos; |
| 253 | af = AF_INET6; |
| 254 | if (M_UNWRITABLE(m, sizeof(*ip6))) { |
| 255 | if ((m = m_pullup(m, sizeof(*ip6))) == NULL) |
| 256 | return; |
| 257 | } |
| 258 | ip6 = mtod(m, struct ip6_hdr *); |
| 259 | itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; |
| 260 | if (gifp->if_flags & IFF_LINK1) |
| 261 | ip_ecn_egress(ECN_ALLOWED, &otos, &itos); |
| 262 | else |
| 263 | ip_ecn_egress(ECN_NOCARE, &otos, &itos); |
| 264 | ip6->ip6_flow &= ~htonl(0xff << 20); |
| 265 | ip6->ip6_flow |= htonl((u_int32_t)itos << 20); |
| 266 | break; |
| 267 | } |
| 268 | #endif /* INET6 */ |
| 269 | default: |
| 270 | ip_statinc(IP_STAT_NOGIF); |
| 271 | m_freem(m); |
| 272 | return; |
| 273 | } |
| 274 | gif_input(m, af, gifp); |
| 275 | return; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * validate outer address. |
| 280 | */ |
| 281 | static int |
| 282 | gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) |
| 283 | { |
| 284 | struct sockaddr_in *src, *dst; |
| 285 | struct in_ifaddr *ia4; |
| 286 | int s; |
| 287 | |
| 288 | src = satosin(sc->gif_psrc); |
| 289 | dst = satosin(sc->gif_pdst); |
| 290 | |
| 291 | /* check for address match */ |
| 292 | if (src->sin_addr.s_addr != ip->ip_dst.s_addr || |
| 293 | dst->sin_addr.s_addr != ip->ip_src.s_addr) |
| 294 | return 0; |
| 295 | |
| 296 | /* martian filters on outer source - NOT done in ip_input! */ |
| 297 | if (IN_MULTICAST(ip->ip_src.s_addr)) |
| 298 | return 0; |
| 299 | switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { |
| 300 | case 0: case 127: case 255: |
| 301 | return 0; |
| 302 | } |
| 303 | /* reject packets with broadcast on source */ |
| 304 | s = pserialize_read_enter(); |
| 305 | IN_ADDRLIST_READER_FOREACH(ia4) { |
| 306 | if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) |
| 307 | continue; |
| 308 | if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { |
| 309 | pserialize_read_exit(s); |
| 310 | return 0; |
| 311 | } |
| 312 | } |
| 313 | pserialize_read_exit(s); |
| 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_in sin; |
| 320 | } u; |
| 321 | struct rtentry *rt; |
| 322 | |
| 323 | sockaddr_in_init(&u.sin, &ip->ip_src, 0); |
| 324 | rt = rtalloc1(&u.sa, 0); |
| 325 | if (rt == NULL || rt->rt_ifp != ifp) { |
| 326 | #if 0 |
| 327 | log(LOG_WARNING, "%s: packet from 0x%x dropped " |
| 328 | "due to ingress filter\n" , if_name(&sc->gif_if), |
| 329 | (u_int32_t)ntohl(u.sin.sin_addr.s_addr)); |
| 330 | #endif |
| 331 | if (rt != NULL) |
| 332 | rtfree(rt); |
| 333 | return 0; |
| 334 | } |
| 335 | rtfree(rt); |
| 336 | } |
| 337 | |
| 338 | return 32 * 2; |
| 339 | } |
| 340 | |
| 341 | #ifdef GIF_ENCAPCHECK |
| 342 | /* |
| 343 | * we know that we are in IFF_UP, outer address available, and outer family |
| 344 | * matched the physical addr family. see gif_encapcheck(). |
| 345 | */ |
| 346 | int |
| 347 | gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) |
| 348 | { |
| 349 | struct ip ip; |
| 350 | struct gif_softc *sc; |
| 351 | struct ifnet *ifp = NULL; |
| 352 | int r; |
| 353 | struct psref psref; |
| 354 | |
| 355 | /* sanity check done in caller */ |
| 356 | sc = arg; |
| 357 | |
| 358 | m_copydata(m, 0, sizeof(ip), &ip); |
| 359 | if ((m->m_flags & M_PKTHDR) != 0) |
| 360 | ifp = m_get_rcvif_psref(m, &psref); |
| 361 | |
| 362 | r = gif_validate4(&ip, sc, ifp); |
| 363 | |
| 364 | m_put_rcvif_psref(ifp, &psref); |
| 365 | return r; |
| 366 | } |
| 367 | #endif |
| 368 | |
| 369 | int |
| 370 | in_gif_attach(struct gif_softc *sc) |
| 371 | { |
| 372 | #ifndef GIF_ENCAPCHECK |
| 373 | struct sockaddr_in mask4; |
| 374 | |
| 375 | memset(&mask4, 0, sizeof(mask4)); |
| 376 | mask4.sin_len = sizeof(struct sockaddr_in); |
| 377 | mask4.sin_addr.s_addr = ~0; |
| 378 | |
| 379 | if (!sc->gif_psrc || !sc->gif_pdst) |
| 380 | return EINVAL; |
| 381 | sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, |
| 382 | (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, |
| 383 | &in_gif_encapsw, sc); |
| 384 | #else |
| 385 | sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, |
| 386 | &in_gif_encapsw, sc); |
| 387 | #endif |
| 388 | if (sc->encap_cookie4 == NULL) |
| 389 | return EEXIST; |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | int |
| 394 | in_gif_detach(struct gif_softc *sc) |
| 395 | { |
| 396 | int error; |
| 397 | |
| 398 | error = in_gif_pause(sc); |
| 399 | |
| 400 | rtcache_free(&sc->gif_ro); |
| 401 | |
| 402 | return error; |
| 403 | } |
| 404 | |
| 405 | int |
| 406 | in_gif_pause(struct gif_softc *sc) |
| 407 | { |
| 408 | int error; |
| 409 | |
| 410 | error = encap_detach(sc->encap_cookie4); |
| 411 | if (error == 0) |
| 412 | sc->encap_cookie4 = NULL; |
| 413 | |
| 414 | return error; |
| 415 | } |
| 416 | |