1 /* $FreeBSD$ */ 2 /* $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 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 "opt_inet.h" 34 #include "opt_inet6.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/socket.h> 39 #include <sys/sockio.h> 40 #include <sys/mbuf.h> 41 #include <sys/errno.h> 42 #include <sys/queue.h> 43 #include <sys/syslog.h> 44 #include <sys/protosw.h> 45 46 #include <sys/malloc.h> 47 48 #include <net/if.h> 49 #include <net/route.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_systm.h> 53 #ifdef INET 54 #include <netinet/ip.h> 55 #endif 56 #include <netinet/ip_encap.h> 57 #ifdef INET6 58 #include <netinet/ip6.h> 59 #include <netinet6/ip6_var.h> 60 #include <netinet6/in6_gif.h> 61 #include <netinet6/in6_var.h> 62 #endif 63 #include <netinet6/ip6protosw.h> 64 #include <netinet/ip_ecn.h> 65 #ifdef INET6 66 #include <netinet6/ip6_ecn.h> 67 #endif 68 69 #include <net/if_gif.h> 70 71 #include <net/net_osdep.h> 72 73 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 74 struct ifnet *); 75 76 extern struct domain inet6domain; 77 struct ip6protosw in6_gif_protosw = 78 { SOCK_RAW, &inet6domain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 79 in6_gif_input, rip6_output, 0, rip6_ctloutput, 80 0, 81 0, 0, 0, 0, 82 &rip6_usrreqs 83 }; 84 85 int 86 in6_gif_output(ifp, family, m) 87 struct ifnet *ifp; 88 int family; /* family of the packet to be encapsulate. */ 89 struct mbuf *m; 90 { 91 struct gif_softc *sc = ifp->if_softc; 92 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 93 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 94 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 95 struct ip6_hdr *ip6; 96 struct etherip_header eiphdr; 97 int proto, error; 98 u_int8_t itos, otos; 99 100 GIF_LOCK_ASSERT(sc); 101 102 if (sin6_src == NULL || sin6_dst == NULL || 103 sin6_src->sin6_family != AF_INET6 || 104 sin6_dst->sin6_family != AF_INET6) { 105 m_freem(m); 106 return EAFNOSUPPORT; 107 } 108 109 switch (family) { 110 #ifdef INET 111 case AF_INET: 112 { 113 struct ip *ip; 114 115 proto = IPPROTO_IPV4; 116 if (m->m_len < sizeof(*ip)) { 117 m = m_pullup(m, sizeof(*ip)); 118 if (!m) 119 return ENOBUFS; 120 } 121 ip = mtod(m, struct ip *); 122 itos = ip->ip_tos; 123 break; 124 } 125 #endif 126 #ifdef INET6 127 case AF_INET6: 128 { 129 struct ip6_hdr *ip6; 130 proto = IPPROTO_IPV6; 131 if (m->m_len < sizeof(*ip6)) { 132 m = m_pullup(m, sizeof(*ip6)); 133 if (!m) 134 return ENOBUFS; 135 } 136 ip6 = mtod(m, struct ip6_hdr *); 137 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 138 break; 139 } 140 #endif 141 case AF_LINK: 142 proto = IPPROTO_ETHERIP; 143 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 144 eiphdr.eip_pad = 0; 145 /* prepend Ethernet-in-IP header */ 146 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 147 if (m && m->m_len < sizeof(struct etherip_header)) 148 m = m_pullup(m, sizeof(struct etherip_header)); 149 if (m == NULL) 150 return ENOBUFS; 151 bcopy(&eiphdr, mtod(m, struct etherip_header *), 152 sizeof(struct etherip_header)); 153 break; 154 155 default: 156 #ifdef DEBUG 157 printf("in6_gif_output: warning: unknown family %d passed\n", 158 family); 159 #endif 160 m_freem(m); 161 return EAFNOSUPPORT; 162 } 163 164 /* prepend new IP header */ 165 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 166 if (m && m->m_len < sizeof(struct ip6_hdr)) 167 m = m_pullup(m, sizeof(struct ip6_hdr)); 168 if (m == NULL) { 169 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 170 return ENOBUFS; 171 } 172 173 ip6 = mtod(m, struct ip6_hdr *); 174 ip6->ip6_flow = 0; 175 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 176 ip6->ip6_vfc |= IPV6_VERSION; 177 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 178 ip6->ip6_nxt = proto; 179 ip6->ip6_hlim = ip6_gif_hlim; 180 ip6->ip6_src = sin6_src->sin6_addr; 181 /* bidirectional configured tunnel mode */ 182 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 183 ip6->ip6_dst = sin6_dst->sin6_addr; 184 else { 185 m_freem(m); 186 return ENETUNREACH; 187 } 188 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 189 &otos, &itos); 190 ip6->ip6_flow &= ~htonl(0xff << 20); 191 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 192 193 if (dst->sin6_family != sin6_dst->sin6_family || 194 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 195 /* cache route doesn't match */ 196 bzero(dst, sizeof(*dst)); 197 dst->sin6_family = sin6_dst->sin6_family; 198 dst->sin6_len = sizeof(struct sockaddr_in6); 199 dst->sin6_addr = sin6_dst->sin6_addr; 200 if (sc->gif_ro6.ro_rt) { 201 RTFREE(sc->gif_ro6.ro_rt); 202 sc->gif_ro6.ro_rt = NULL; 203 } 204 #if 0 205 GIF2IFP(sc)->if_mtu = GIF_MTU; 206 #endif 207 } 208 209 if (sc->gif_ro6.ro_rt == NULL) { 210 rtalloc((struct route *)&sc->gif_ro6); 211 if (sc->gif_ro6.ro_rt == NULL) { 212 m_freem(m); 213 return ENETUNREACH; 214 } 215 216 /* if it constitutes infinite encapsulation, punt. */ 217 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 218 m_freem(m); 219 return ENETUNREACH; /*XXX*/ 220 } 221 #if 0 222 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 223 - sizeof(struct ip6_hdr); 224 #endif 225 } 226 227 #ifdef IPV6_MINMTU 228 /* 229 * force fragmentation to minimum MTU, to avoid path MTU discovery. 230 * it is too painful to ask for resend of inner packet, to achieve 231 * path MTU discovery for encapsulated packets. 232 */ 233 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 234 #else 235 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 236 #endif 237 238 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 239 sc->gif_ro6.ro_rt != NULL) { 240 RTFREE(sc->gif_ro6.ro_rt); 241 sc->gif_ro6.ro_rt = NULL; 242 } 243 244 return (error); 245 } 246 247 int 248 in6_gif_input(mp, offp, proto) 249 struct mbuf **mp; 250 int *offp, proto; 251 { 252 struct mbuf *m = *mp; 253 struct ifnet *gifp = NULL; 254 struct gif_softc *sc; 255 struct ip6_hdr *ip6; 256 int af = 0; 257 u_int32_t otos; 258 259 ip6 = mtod(m, struct ip6_hdr *); 260 261 sc = (struct gif_softc *)encap_getarg(m); 262 if (sc == NULL) { 263 m_freem(m); 264 ip6stat.ip6s_nogif++; 265 return IPPROTO_DONE; 266 } 267 268 gifp = GIF2IFP(sc); 269 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 270 m_freem(m); 271 ip6stat.ip6s_nogif++; 272 return IPPROTO_DONE; 273 } 274 275 otos = ip6->ip6_flow; 276 m_adj(m, *offp); 277 278 switch (proto) { 279 #ifdef INET 280 case IPPROTO_IPV4: 281 { 282 struct ip *ip; 283 u_int8_t otos8; 284 af = AF_INET; 285 otos8 = (ntohl(otos) >> 20) & 0xff; 286 if (m->m_len < sizeof(*ip)) { 287 m = m_pullup(m, sizeof(*ip)); 288 if (!m) 289 return IPPROTO_DONE; 290 } 291 ip = mtod(m, struct ip *); 292 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 293 ECN_ALLOWED : ECN_NOCARE, 294 &otos8, &ip->ip_tos) == 0) { 295 m_freem(m); 296 return IPPROTO_DONE; 297 } 298 break; 299 } 300 #endif /* INET */ 301 #ifdef INET6 302 case IPPROTO_IPV6: 303 { 304 struct ip6_hdr *ip6; 305 af = AF_INET6; 306 if (m->m_len < sizeof(*ip6)) { 307 m = m_pullup(m, sizeof(*ip6)); 308 if (!m) 309 return IPPROTO_DONE; 310 } 311 ip6 = mtod(m, struct ip6_hdr *); 312 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 313 ECN_ALLOWED : ECN_NOCARE, 314 &otos, &ip6->ip6_flow) == 0) { 315 m_freem(m); 316 return IPPROTO_DONE; 317 } 318 break; 319 } 320 #endif 321 case IPPROTO_ETHERIP: 322 af = AF_LINK; 323 break; 324 325 default: 326 ip6stat.ip6s_nogif++; 327 m_freem(m); 328 return IPPROTO_DONE; 329 } 330 331 gif_input(m, af, gifp); 332 return IPPROTO_DONE; 333 } 334 335 /* 336 * validate outer address. 337 */ 338 static int 339 gif_validate6(ip6, sc, ifp) 340 const struct ip6_hdr *ip6; 341 struct gif_softc *sc; 342 struct ifnet *ifp; 343 { 344 struct sockaddr_in6 *src, *dst; 345 346 src = (struct sockaddr_in6 *)sc->gif_psrc; 347 dst = (struct sockaddr_in6 *)sc->gif_pdst; 348 349 /* 350 * Check for address match. Note that the check is for an incoming 351 * packet. We should compare the *source* address in our configuration 352 * and the *destination* address of the packet, and vice versa. 353 */ 354 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 355 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 356 return 0; 357 358 /* martian filters on outer source - done in ip6_input */ 359 360 /* ingress filters on outer source */ 361 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 362 struct sockaddr_in6 sin6; 363 struct rtentry *rt; 364 365 bzero(&sin6, sizeof(sin6)); 366 sin6.sin6_family = AF_INET6; 367 sin6.sin6_len = sizeof(struct sockaddr_in6); 368 sin6.sin6_addr = ip6->ip6_src; 369 sin6.sin6_scope_id = 0; /* XXX */ 370 371 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 372 if (!rt || rt->rt_ifp != ifp) { 373 #if 0 374 log(LOG_WARNING, "%s: packet from %s dropped " 375 "due to ingress filter\n", if_name(GIF2IFP(sc)), 376 ip6_sprintf(&sin6.sin6_addr)); 377 #endif 378 if (rt) 379 rtfree(rt); 380 return 0; 381 } 382 rtfree(rt); 383 } 384 385 return 128 * 2; 386 } 387 388 /* 389 * we know that we are in IFF_UP, outer address available, and outer family 390 * matched the physical addr family. see gif_encapcheck(). 391 * sanity check for arg should have been done in the caller. 392 */ 393 int 394 gif_encapcheck6(m, off, proto, arg) 395 const struct mbuf *m; 396 int off; 397 int proto; 398 void *arg; 399 { 400 struct ip6_hdr ip6; 401 struct gif_softc *sc; 402 struct ifnet *ifp; 403 404 /* sanity check done in caller */ 405 sc = (struct gif_softc *)arg; 406 407 /* LINTED const cast */ 408 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 409 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 410 411 return gif_validate6(&ip6, sc, ifp); 412 } 413 414 int 415 in6_gif_attach(sc) 416 struct gif_softc *sc; 417 { 418 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 419 (void *)&in6_gif_protosw, sc); 420 if (sc->encap_cookie6 == NULL) 421 return EEXIST; 422 return 0; 423 } 424 425 int 426 in6_gif_detach(sc) 427 struct gif_softc *sc; 428 { 429 int error; 430 431 error = encap_detach(sc->encap_cookie6); 432 if (error == 0) 433 sc->encap_cookie6 = NULL; 434 return error; 435 } 436