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 #include <netinet6/vinet6.h> 70 #endif 71 72 #include <net/if_gif.h> 73 74 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 75 struct ifnet *); 76 77 extern struct domain inet6domain; 78 struct ip6protosw in6_gif_protosw = { 79 .pr_type = SOCK_RAW, 80 .pr_domain = &inet6domain, 81 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 82 .pr_flags = PR_ATOMIC|PR_ADDR, 83 .pr_input = in6_gif_input, 84 .pr_output = rip6_output, 85 .pr_ctloutput = rip6_ctloutput, 86 .pr_usrreqs = &rip6_usrreqs 87 }; 88 89 int 90 in6_gif_output(struct ifnet *ifp, 91 int family, /* family of the packet to be encapsulate */ 92 struct mbuf *m) 93 { 94 INIT_VNET_GIF(ifp->if_vnet); 95 struct gif_softc *sc = ifp->if_softc; 96 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 97 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 98 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 99 struct ip6_hdr *ip6; 100 struct etherip_header eiphdr; 101 int proto, error; 102 u_int8_t itos, otos; 103 104 GIF_LOCK_ASSERT(sc); 105 106 if (sin6_src == NULL || sin6_dst == NULL || 107 sin6_src->sin6_family != AF_INET6 || 108 sin6_dst->sin6_family != AF_INET6) { 109 m_freem(m); 110 return EAFNOSUPPORT; 111 } 112 113 switch (family) { 114 #ifdef INET 115 case AF_INET: 116 { 117 struct ip *ip; 118 119 proto = IPPROTO_IPV4; 120 if (m->m_len < sizeof(*ip)) { 121 m = m_pullup(m, sizeof(*ip)); 122 if (!m) 123 return ENOBUFS; 124 } 125 ip = mtod(m, struct ip *); 126 itos = ip->ip_tos; 127 break; 128 } 129 #endif 130 #ifdef INET6 131 case AF_INET6: 132 { 133 struct ip6_hdr *ip6; 134 proto = IPPROTO_IPV6; 135 if (m->m_len < sizeof(*ip6)) { 136 m = m_pullup(m, sizeof(*ip6)); 137 if (!m) 138 return ENOBUFS; 139 } 140 ip6 = mtod(m, struct ip6_hdr *); 141 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 142 break; 143 } 144 #endif 145 case AF_LINK: 146 proto = IPPROTO_ETHERIP; 147 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 148 eiphdr.eip_pad = 0; 149 /* prepend Ethernet-in-IP header */ 150 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 151 if (m && m->m_len < sizeof(struct etherip_header)) 152 m = m_pullup(m, sizeof(struct etherip_header)); 153 if (m == NULL) 154 return ENOBUFS; 155 bcopy(&eiphdr, mtod(m, struct etherip_header *), 156 sizeof(struct etherip_header)); 157 break; 158 159 default: 160 #ifdef DEBUG 161 printf("in6_gif_output: warning: unknown family %d passed\n", 162 family); 163 #endif 164 m_freem(m); 165 return EAFNOSUPPORT; 166 } 167 168 /* prepend new IP header */ 169 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 170 if (m && m->m_len < sizeof(struct ip6_hdr)) 171 m = m_pullup(m, sizeof(struct ip6_hdr)); 172 if (m == NULL) { 173 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 174 return ENOBUFS; 175 } 176 177 ip6 = mtod(m, struct ip6_hdr *); 178 ip6->ip6_flow = 0; 179 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 180 ip6->ip6_vfc |= IPV6_VERSION; 181 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 182 ip6->ip6_nxt = proto; 183 ip6->ip6_hlim = V_ip6_gif_hlim; 184 ip6->ip6_src = sin6_src->sin6_addr; 185 /* bidirectional configured tunnel mode */ 186 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 187 ip6->ip6_dst = sin6_dst->sin6_addr; 188 else { 189 m_freem(m); 190 return ENETUNREACH; 191 } 192 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 193 &otos, &itos); 194 ip6->ip6_flow &= ~htonl(0xff << 20); 195 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 196 197 if (dst->sin6_family != sin6_dst->sin6_family || 198 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 199 /* cache route doesn't match */ 200 bzero(dst, sizeof(*dst)); 201 dst->sin6_family = sin6_dst->sin6_family; 202 dst->sin6_len = sizeof(struct sockaddr_in6); 203 dst->sin6_addr = sin6_dst->sin6_addr; 204 if (sc->gif_ro6.ro_rt) { 205 RTFREE(sc->gif_ro6.ro_rt); 206 sc->gif_ro6.ro_rt = NULL; 207 } 208 #if 0 209 GIF2IFP(sc)->if_mtu = GIF_MTU; 210 #endif 211 } 212 213 if (sc->gif_ro6.ro_rt == NULL) { 214 rtalloc((struct route *)&sc->gif_ro6); 215 if (sc->gif_ro6.ro_rt == NULL) { 216 m_freem(m); 217 return ENETUNREACH; 218 } 219 220 /* if it constitutes infinite encapsulation, punt. */ 221 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 222 m_freem(m); 223 return ENETUNREACH; /*XXX*/ 224 } 225 #if 0 226 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 227 - sizeof(struct ip6_hdr); 228 #endif 229 } 230 231 #ifdef IPV6_MINMTU 232 /* 233 * force fragmentation to minimum MTU, to avoid path MTU discovery. 234 * it is too painful to ask for resend of inner packet, to achieve 235 * path MTU discovery for encapsulated packets. 236 */ 237 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 238 #else 239 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 240 #endif 241 242 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 243 sc->gif_ro6.ro_rt != NULL) { 244 RTFREE(sc->gif_ro6.ro_rt); 245 sc->gif_ro6.ro_rt = NULL; 246 } 247 248 return (error); 249 } 250 251 int 252 in6_gif_input(struct mbuf **mp, int *offp, int proto) 253 { 254 INIT_VNET_INET6(curvnet); 255 struct mbuf *m = *mp; 256 struct ifnet *gifp = NULL; 257 struct gif_softc *sc; 258 struct ip6_hdr *ip6; 259 int af = 0; 260 u_int32_t otos; 261 262 ip6 = mtod(m, struct ip6_hdr *); 263 264 sc = (struct gif_softc *)encap_getarg(m); 265 if (sc == NULL) { 266 m_freem(m); 267 V_ip6stat.ip6s_nogif++; 268 return IPPROTO_DONE; 269 } 270 271 gifp = GIF2IFP(sc); 272 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 273 m_freem(m); 274 V_ip6stat.ip6s_nogif++; 275 return IPPROTO_DONE; 276 } 277 278 otos = ip6->ip6_flow; 279 m_adj(m, *offp); 280 281 switch (proto) { 282 #ifdef INET 283 case IPPROTO_IPV4: 284 { 285 struct ip *ip; 286 u_int8_t otos8; 287 af = AF_INET; 288 otos8 = (ntohl(otos) >> 20) & 0xff; 289 if (m->m_len < sizeof(*ip)) { 290 m = m_pullup(m, sizeof(*ip)); 291 if (!m) 292 return IPPROTO_DONE; 293 } 294 ip = mtod(m, struct ip *); 295 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 296 ECN_ALLOWED : ECN_NOCARE, 297 &otos8, &ip->ip_tos) == 0) { 298 m_freem(m); 299 return IPPROTO_DONE; 300 } 301 break; 302 } 303 #endif /* INET */ 304 #ifdef INET6 305 case IPPROTO_IPV6: 306 { 307 struct ip6_hdr *ip6; 308 af = AF_INET6; 309 if (m->m_len < sizeof(*ip6)) { 310 m = m_pullup(m, sizeof(*ip6)); 311 if (!m) 312 return IPPROTO_DONE; 313 } 314 ip6 = mtod(m, struct ip6_hdr *); 315 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 316 ECN_ALLOWED : ECN_NOCARE, 317 &otos, &ip6->ip6_flow) == 0) { 318 m_freem(m); 319 return IPPROTO_DONE; 320 } 321 break; 322 } 323 #endif 324 case IPPROTO_ETHERIP: 325 af = AF_LINK; 326 break; 327 328 default: 329 V_ip6stat.ip6s_nogif++; 330 m_freem(m); 331 return IPPROTO_DONE; 332 } 333 334 gif_input(m, af, gifp); 335 return IPPROTO_DONE; 336 } 337 338 /* 339 * validate outer address. 340 */ 341 static int 342 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 343 struct ifnet *ifp) 344 { 345 struct sockaddr_in6 *src, *dst; 346 347 src = (struct sockaddr_in6 *)sc->gif_psrc; 348 dst = (struct sockaddr_in6 *)sc->gif_pdst; 349 350 /* 351 * Check for address match. Note that the check is for an incoming 352 * packet. We should compare the *source* address in our configuration 353 * and the *destination* address of the packet, and vice versa. 354 */ 355 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 356 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 357 return 0; 358 359 /* martian filters on outer source - done in ip6_input */ 360 361 /* ingress filters on outer source */ 362 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 363 struct sockaddr_in6 sin6; 364 struct rtentry *rt; 365 366 bzero(&sin6, sizeof(sin6)); 367 sin6.sin6_family = AF_INET6; 368 sin6.sin6_len = sizeof(struct sockaddr_in6); 369 sin6.sin6_addr = ip6->ip6_src; 370 sin6.sin6_scope_id = 0; /* XXX */ 371 372 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 373 if (!rt || rt->rt_ifp != ifp) { 374 #if 0 375 char ip6buf[INET6_ADDRSTRLEN]; 376 log(LOG_WARNING, "%s: packet from %s dropped " 377 "due to ingress filter\n", if_name(GIF2IFP(sc)), 378 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 379 #endif 380 if (rt) 381 rtfree(rt); 382 return 0; 383 } 384 rtfree(rt); 385 } 386 387 return 128 * 2; 388 } 389 390 /* 391 * we know that we are in IFF_UP, outer address available, and outer family 392 * matched the physical addr family. see gif_encapcheck(). 393 * sanity check for arg should have been done in the caller. 394 */ 395 int 396 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 397 { 398 struct ip6_hdr ip6; 399 struct gif_softc *sc; 400 struct ifnet *ifp; 401 402 /* sanity check done in caller */ 403 sc = (struct gif_softc *)arg; 404 405 /* LINTED const cast */ 406 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 407 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 408 409 return gif_validate6(&ip6, sc, ifp); 410 } 411 412 int 413 in6_gif_attach(struct gif_softc *sc) 414 { 415 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 416 (void *)&in6_gif_protosw, sc); 417 if (sc->encap_cookie6 == NULL) 418 return EEXIST; 419 return 0; 420 } 421 422 int 423 in6_gif_detach(struct gif_softc *sc) 424 { 425 int error; 426 427 error = encap_detach(sc->encap_cookie6); 428 if (error == 0) 429 sc->encap_cookie6 = NULL; 430 return error; 431 } 432