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 48 #include <sys/malloc.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 struct gif_softc *sc = ifp->if_softc; 91 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 92 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 93 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 94 struct ip6_hdr *ip6; 95 struct etherip_header eiphdr; 96 int proto, error; 97 u_int8_t itos, otos; 98 99 GIF_LOCK_ASSERT(sc); 100 101 if (sin6_src == NULL || sin6_dst == NULL || 102 sin6_src->sin6_family != AF_INET6 || 103 sin6_dst->sin6_family != AF_INET6) { 104 m_freem(m); 105 return EAFNOSUPPORT; 106 } 107 108 switch (family) { 109 #ifdef INET 110 case AF_INET: 111 { 112 struct ip *ip; 113 114 proto = IPPROTO_IPV4; 115 if (m->m_len < sizeof(*ip)) { 116 m = m_pullup(m, sizeof(*ip)); 117 if (!m) 118 return ENOBUFS; 119 } 120 ip = mtod(m, struct ip *); 121 itos = ip->ip_tos; 122 break; 123 } 124 #endif 125 #ifdef INET6 126 case AF_INET6: 127 { 128 struct ip6_hdr *ip6; 129 proto = IPPROTO_IPV6; 130 if (m->m_len < sizeof(*ip6)) { 131 m = m_pullup(m, sizeof(*ip6)); 132 if (!m) 133 return ENOBUFS; 134 } 135 ip6 = mtod(m, struct ip6_hdr *); 136 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 137 break; 138 } 139 #endif 140 case AF_LINK: 141 proto = IPPROTO_ETHERIP; 142 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 143 eiphdr.eip_pad = 0; 144 /* prepend Ethernet-in-IP header */ 145 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 146 if (m && m->m_len < sizeof(struct etherip_header)) 147 m = m_pullup(m, sizeof(struct etherip_header)); 148 if (m == NULL) 149 return ENOBUFS; 150 bcopy(&eiphdr, mtod(m, struct etherip_header *), 151 sizeof(struct etherip_header)); 152 break; 153 154 default: 155 #ifdef DEBUG 156 printf("in6_gif_output: warning: unknown family %d passed\n", 157 family); 158 #endif 159 m_freem(m); 160 return EAFNOSUPPORT; 161 } 162 163 /* prepend new IP header */ 164 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 165 if (m && m->m_len < sizeof(struct ip6_hdr)) 166 m = m_pullup(m, sizeof(struct ip6_hdr)); 167 if (m == NULL) { 168 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 169 return ENOBUFS; 170 } 171 172 ip6 = mtod(m, struct ip6_hdr *); 173 ip6->ip6_flow = 0; 174 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 175 ip6->ip6_vfc |= IPV6_VERSION; 176 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 177 ip6->ip6_nxt = proto; 178 ip6->ip6_hlim = ip6_gif_hlim; 179 ip6->ip6_src = sin6_src->sin6_addr; 180 /* bidirectional configured tunnel mode */ 181 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 182 ip6->ip6_dst = sin6_dst->sin6_addr; 183 else { 184 m_freem(m); 185 return ENETUNREACH; 186 } 187 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 188 &otos, &itos); 189 ip6->ip6_flow &= ~htonl(0xff << 20); 190 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 191 192 if (dst->sin6_family != sin6_dst->sin6_family || 193 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 194 /* cache route doesn't match */ 195 bzero(dst, sizeof(*dst)); 196 dst->sin6_family = sin6_dst->sin6_family; 197 dst->sin6_len = sizeof(struct sockaddr_in6); 198 dst->sin6_addr = sin6_dst->sin6_addr; 199 if (sc->gif_ro6.ro_rt) { 200 RTFREE(sc->gif_ro6.ro_rt); 201 sc->gif_ro6.ro_rt = NULL; 202 } 203 #if 0 204 GIF2IFP(sc)->if_mtu = GIF_MTU; 205 #endif 206 } 207 208 if (sc->gif_ro6.ro_rt == NULL) { 209 rtalloc((struct route *)&sc->gif_ro6); 210 if (sc->gif_ro6.ro_rt == NULL) { 211 m_freem(m); 212 return ENETUNREACH; 213 } 214 215 /* if it constitutes infinite encapsulation, punt. */ 216 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 217 m_freem(m); 218 return ENETUNREACH; /*XXX*/ 219 } 220 #if 0 221 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 222 - sizeof(struct ip6_hdr); 223 #endif 224 } 225 226 #ifdef IPV6_MINMTU 227 /* 228 * force fragmentation to minimum MTU, to avoid path MTU discovery. 229 * it is too painful to ask for resend of inner packet, to achieve 230 * path MTU discovery for encapsulated packets. 231 */ 232 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 233 #else 234 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 235 #endif 236 237 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 238 sc->gif_ro6.ro_rt != NULL) { 239 RTFREE(sc->gif_ro6.ro_rt); 240 sc->gif_ro6.ro_rt = NULL; 241 } 242 243 return (error); 244 } 245 246 int 247 in6_gif_input(struct mbuf **mp, int *offp, int proto) 248 { 249 struct mbuf *m = *mp; 250 struct ifnet *gifp = NULL; 251 struct gif_softc *sc; 252 struct ip6_hdr *ip6; 253 int af = 0; 254 u_int32_t otos; 255 256 ip6 = mtod(m, struct ip6_hdr *); 257 258 sc = (struct gif_softc *)encap_getarg(m); 259 if (sc == NULL) { 260 m_freem(m); 261 ip6stat.ip6s_nogif++; 262 return IPPROTO_DONE; 263 } 264 265 gifp = GIF2IFP(sc); 266 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 267 m_freem(m); 268 ip6stat.ip6s_nogif++; 269 return IPPROTO_DONE; 270 } 271 272 otos = ip6->ip6_flow; 273 m_adj(m, *offp); 274 275 switch (proto) { 276 #ifdef INET 277 case IPPROTO_IPV4: 278 { 279 struct ip *ip; 280 u_int8_t otos8; 281 af = AF_INET; 282 otos8 = (ntohl(otos) >> 20) & 0xff; 283 if (m->m_len < sizeof(*ip)) { 284 m = m_pullup(m, sizeof(*ip)); 285 if (!m) 286 return IPPROTO_DONE; 287 } 288 ip = mtod(m, struct ip *); 289 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 290 ECN_ALLOWED : ECN_NOCARE, 291 &otos8, &ip->ip_tos) == 0) { 292 m_freem(m); 293 return IPPROTO_DONE; 294 } 295 break; 296 } 297 #endif /* INET */ 298 #ifdef INET6 299 case IPPROTO_IPV6: 300 { 301 struct ip6_hdr *ip6; 302 af = AF_INET6; 303 if (m->m_len < sizeof(*ip6)) { 304 m = m_pullup(m, sizeof(*ip6)); 305 if (!m) 306 return IPPROTO_DONE; 307 } 308 ip6 = mtod(m, struct ip6_hdr *); 309 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 310 ECN_ALLOWED : ECN_NOCARE, 311 &otos, &ip6->ip6_flow) == 0) { 312 m_freem(m); 313 return IPPROTO_DONE; 314 } 315 break; 316 } 317 #endif 318 case IPPROTO_ETHERIP: 319 af = AF_LINK; 320 break; 321 322 default: 323 ip6stat.ip6s_nogif++; 324 m_freem(m); 325 return IPPROTO_DONE; 326 } 327 328 gif_input(m, af, gifp); 329 return IPPROTO_DONE; 330 } 331 332 /* 333 * validate outer address. 334 */ 335 static int 336 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 337 struct ifnet *ifp) 338 { 339 struct sockaddr_in6 *src, *dst; 340 341 src = (struct sockaddr_in6 *)sc->gif_psrc; 342 dst = (struct sockaddr_in6 *)sc->gif_pdst; 343 344 /* 345 * Check for address match. Note that the check is for an incoming 346 * packet. We should compare the *source* address in our configuration 347 * and the *destination* address of the packet, and vice versa. 348 */ 349 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 350 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 351 return 0; 352 353 /* martian filters on outer source - done in ip6_input */ 354 355 /* ingress filters on outer source */ 356 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 357 struct sockaddr_in6 sin6; 358 struct rtentry *rt; 359 360 bzero(&sin6, sizeof(sin6)); 361 sin6.sin6_family = AF_INET6; 362 sin6.sin6_len = sizeof(struct sockaddr_in6); 363 sin6.sin6_addr = ip6->ip6_src; 364 sin6.sin6_scope_id = 0; /* XXX */ 365 366 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 367 if (!rt || rt->rt_ifp != ifp) { 368 #if 0 369 char ip6buf[INET6_ADDRSTRLEN]; 370 log(LOG_WARNING, "%s: packet from %s dropped " 371 "due to ingress filter\n", if_name(GIF2IFP(sc)), 372 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 373 #endif 374 if (rt) 375 rtfree(rt); 376 return 0; 377 } 378 rtfree(rt); 379 } 380 381 return 128 * 2; 382 } 383 384 /* 385 * we know that we are in IFF_UP, outer address available, and outer family 386 * matched the physical addr family. see gif_encapcheck(). 387 * sanity check for arg should have been done in the caller. 388 */ 389 int 390 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 391 { 392 struct ip6_hdr ip6; 393 struct gif_softc *sc; 394 struct ifnet *ifp; 395 396 /* sanity check done in caller */ 397 sc = (struct gif_softc *)arg; 398 399 /* LINTED const cast */ 400 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 401 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 402 403 return gif_validate6(&ip6, sc, ifp); 404 } 405 406 int 407 in6_gif_attach(struct gif_softc *sc) 408 { 409 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 410 (void *)&in6_gif_protosw, sc); 411 if (sc->encap_cookie6 == NULL) 412 return EEXIST; 413 return 0; 414 } 415 416 int 417 in6_gif_detach(struct gif_softc *sc) 418 { 419 int error; 420 421 error = encap_detach(sc->encap_cookie6); 422 if (error == 0) 423 sc->encap_cookie6 = NULL; 424 return error; 425 } 426