1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/socket.h> 41 #include <sys/sockio.h> 42 #include <sys/mbuf.h> 43 #include <sys/errno.h> 44 #include <sys/queue.h> 45 #include <sys/syslog.h> 46 #include <sys/protosw.h> 47 #include <sys/malloc.h> 48 #include <sys/vimage.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 #ifdef INET 56 #include <netinet/ip.h> 57 #endif 58 #include <netinet/ip_encap.h> 59 #ifdef INET6 60 #include <netinet/ip6.h> 61 #include <netinet6/ip6_var.h> 62 #include <netinet6/in6_gif.h> 63 #include <netinet6/in6_var.h> 64 #endif 65 #include <netinet6/ip6protosw.h> 66 #include <netinet/ip_ecn.h> 67 #ifdef INET6 68 #include <netinet6/ip6_ecn.h> 69 #endif 70 71 #include <net/if_gif.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(struct ifnet *ifp, 87 int family, /* family of the packet to be encapsulate */ 88 struct mbuf *m) 89 { 90 INIT_VNET_GIF(ifp->if_vnet); 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 = V_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(struct mbuf **mp, int *offp, int proto) 249 { 250 INIT_VNET_INET6(curvnet); 251 struct mbuf *m = *mp; 252 struct ifnet *gifp = NULL; 253 struct gif_softc *sc; 254 struct ip6_hdr *ip6; 255 int af = 0; 256 u_int32_t otos; 257 258 ip6 = mtod(m, struct ip6_hdr *); 259 260 sc = (struct gif_softc *)encap_getarg(m); 261 if (sc == NULL) { 262 m_freem(m); 263 V_ip6stat.ip6s_nogif++; 264 return IPPROTO_DONE; 265 } 266 267 gifp = GIF2IFP(sc); 268 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 269 m_freem(m); 270 V_ip6stat.ip6s_nogif++; 271 return IPPROTO_DONE; 272 } 273 274 otos = ip6->ip6_flow; 275 m_adj(m, *offp); 276 277 switch (proto) { 278 #ifdef INET 279 case IPPROTO_IPV4: 280 { 281 struct ip *ip; 282 u_int8_t otos8; 283 af = AF_INET; 284 otos8 = (ntohl(otos) >> 20) & 0xff; 285 if (m->m_len < sizeof(*ip)) { 286 m = m_pullup(m, sizeof(*ip)); 287 if (!m) 288 return IPPROTO_DONE; 289 } 290 ip = mtod(m, struct ip *); 291 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 292 ECN_ALLOWED : ECN_NOCARE, 293 &otos8, &ip->ip_tos) == 0) { 294 m_freem(m); 295 return IPPROTO_DONE; 296 } 297 break; 298 } 299 #endif /* INET */ 300 #ifdef INET6 301 case IPPROTO_IPV6: 302 { 303 struct ip6_hdr *ip6; 304 af = AF_INET6; 305 if (m->m_len < sizeof(*ip6)) { 306 m = m_pullup(m, sizeof(*ip6)); 307 if (!m) 308 return IPPROTO_DONE; 309 } 310 ip6 = mtod(m, struct ip6_hdr *); 311 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 312 ECN_ALLOWED : ECN_NOCARE, 313 &otos, &ip6->ip6_flow) == 0) { 314 m_freem(m); 315 return IPPROTO_DONE; 316 } 317 break; 318 } 319 #endif 320 case IPPROTO_ETHERIP: 321 af = AF_LINK; 322 break; 323 324 default: 325 V_ip6stat.ip6s_nogif++; 326 m_freem(m); 327 return IPPROTO_DONE; 328 } 329 330 gif_input(m, af, gifp); 331 return IPPROTO_DONE; 332 } 333 334 /* 335 * validate outer address. 336 */ 337 static int 338 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 339 struct ifnet *ifp) 340 { 341 struct sockaddr_in6 *src, *dst; 342 343 src = (struct sockaddr_in6 *)sc->gif_psrc; 344 dst = (struct sockaddr_in6 *)sc->gif_pdst; 345 346 /* 347 * Check for address match. Note that the check is for an incoming 348 * packet. We should compare the *source* address in our configuration 349 * and the *destination* address of the packet, and vice versa. 350 */ 351 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 352 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 353 return 0; 354 355 /* martian filters on outer source - done in ip6_input */ 356 357 /* ingress filters on outer source */ 358 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 359 struct sockaddr_in6 sin6; 360 struct rtentry *rt; 361 362 bzero(&sin6, sizeof(sin6)); 363 sin6.sin6_family = AF_INET6; 364 sin6.sin6_len = sizeof(struct sockaddr_in6); 365 sin6.sin6_addr = ip6->ip6_src; 366 sin6.sin6_scope_id = 0; /* XXX */ 367 368 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 369 if (!rt || rt->rt_ifp != ifp) { 370 #if 0 371 char ip6buf[INET6_ADDRSTRLEN]; 372 log(LOG_WARNING, "%s: packet from %s dropped " 373 "due to ingress filter\n", if_name(GIF2IFP(sc)), 374 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 375 #endif 376 if (rt) 377 rtfree(rt); 378 return 0; 379 } 380 rtfree(rt); 381 } 382 383 return 128 * 2; 384 } 385 386 /* 387 * we know that we are in IFF_UP, outer address available, and outer family 388 * matched the physical addr family. see gif_encapcheck(). 389 * sanity check for arg should have been done in the caller. 390 */ 391 int 392 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 393 { 394 struct ip6_hdr ip6; 395 struct gif_softc *sc; 396 struct ifnet *ifp; 397 398 /* sanity check done in caller */ 399 sc = (struct gif_softc *)arg; 400 401 /* LINTED const cast */ 402 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 403 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 404 405 return gif_validate6(&ip6, sc, ifp); 406 } 407 408 int 409 in6_gif_attach(struct gif_softc *sc) 410 { 411 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 412 (void *)&in6_gif_protosw, sc); 413 if (sc->encap_cookie6 == NULL) 414 return EEXIST; 415 return 0; 416 } 417 418 int 419 in6_gif_detach(struct gif_softc *sc) 420 { 421 int error; 422 423 error = encap_detach(sc->encap_cookie6); 424 if (error == 0) 425 sc->encap_cookie6 = NULL; 426 return error; 427 } 428