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 static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 72 struct ifnet *); 73 74 extern struct domain inet6domain; 75 struct ip6protosw in6_gif_protosw = 76 { SOCK_RAW, &inet6domain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 77 in6_gif_input, rip6_output, 0, rip6_ctloutput, 78 0, 79 0, 0, 0, 0, 80 &rip6_usrreqs 81 }; 82 83 int 84 in6_gif_output(struct ifnet *ifp, 85 int family, /* family of the packet to be encapsulate */ 86 struct mbuf *m) 87 { 88 struct gif_softc *sc = ifp->if_softc; 89 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 90 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 91 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 92 struct ip6_hdr *ip6; 93 struct etherip_header eiphdr; 94 int proto, error; 95 u_int8_t itos, otos; 96 97 GIF_LOCK_ASSERT(sc); 98 99 if (sin6_src == NULL || sin6_dst == NULL || 100 sin6_src->sin6_family != AF_INET6 || 101 sin6_dst->sin6_family != AF_INET6) { 102 m_freem(m); 103 return EAFNOSUPPORT; 104 } 105 106 switch (family) { 107 #ifdef INET 108 case AF_INET: 109 { 110 struct ip *ip; 111 112 proto = IPPROTO_IPV4; 113 if (m->m_len < sizeof(*ip)) { 114 m = m_pullup(m, sizeof(*ip)); 115 if (!m) 116 return ENOBUFS; 117 } 118 ip = mtod(m, struct ip *); 119 itos = ip->ip_tos; 120 break; 121 } 122 #endif 123 #ifdef INET6 124 case AF_INET6: 125 { 126 struct ip6_hdr *ip6; 127 proto = IPPROTO_IPV6; 128 if (m->m_len < sizeof(*ip6)) { 129 m = m_pullup(m, sizeof(*ip6)); 130 if (!m) 131 return ENOBUFS; 132 } 133 ip6 = mtod(m, struct ip6_hdr *); 134 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 135 break; 136 } 137 #endif 138 case AF_LINK: 139 proto = IPPROTO_ETHERIP; 140 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 141 eiphdr.eip_pad = 0; 142 /* prepend Ethernet-in-IP header */ 143 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 144 if (m && m->m_len < sizeof(struct etherip_header)) 145 m = m_pullup(m, sizeof(struct etherip_header)); 146 if (m == NULL) 147 return ENOBUFS; 148 bcopy(&eiphdr, mtod(m, struct etherip_header *), 149 sizeof(struct etherip_header)); 150 break; 151 152 default: 153 #ifdef DEBUG 154 printf("in6_gif_output: warning: unknown family %d passed\n", 155 family); 156 #endif 157 m_freem(m); 158 return EAFNOSUPPORT; 159 } 160 161 /* prepend new IP header */ 162 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 163 if (m && m->m_len < sizeof(struct ip6_hdr)) 164 m = m_pullup(m, sizeof(struct ip6_hdr)); 165 if (m == NULL) { 166 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 167 return ENOBUFS; 168 } 169 170 ip6 = mtod(m, struct ip6_hdr *); 171 ip6->ip6_flow = 0; 172 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 173 ip6->ip6_vfc |= IPV6_VERSION; 174 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 175 ip6->ip6_nxt = proto; 176 ip6->ip6_hlim = ip6_gif_hlim; 177 ip6->ip6_src = sin6_src->sin6_addr; 178 /* bidirectional configured tunnel mode */ 179 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 180 ip6->ip6_dst = sin6_dst->sin6_addr; 181 else { 182 m_freem(m); 183 return ENETUNREACH; 184 } 185 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 186 &otos, &itos); 187 ip6->ip6_flow &= ~htonl(0xff << 20); 188 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 189 190 if (dst->sin6_family != sin6_dst->sin6_family || 191 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 192 /* cache route doesn't match */ 193 bzero(dst, sizeof(*dst)); 194 dst->sin6_family = sin6_dst->sin6_family; 195 dst->sin6_len = sizeof(struct sockaddr_in6); 196 dst->sin6_addr = sin6_dst->sin6_addr; 197 if (sc->gif_ro6.ro_rt) { 198 RTFREE(sc->gif_ro6.ro_rt); 199 sc->gif_ro6.ro_rt = NULL; 200 } 201 #if 0 202 GIF2IFP(sc)->if_mtu = GIF_MTU; 203 #endif 204 } 205 206 if (sc->gif_ro6.ro_rt == NULL) { 207 rtalloc((struct route *)&sc->gif_ro6); 208 if (sc->gif_ro6.ro_rt == NULL) { 209 m_freem(m); 210 return ENETUNREACH; 211 } 212 213 /* if it constitutes infinite encapsulation, punt. */ 214 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 215 m_freem(m); 216 return ENETUNREACH; /*XXX*/ 217 } 218 #if 0 219 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 220 - sizeof(struct ip6_hdr); 221 #endif 222 } 223 224 #ifdef IPV6_MINMTU 225 /* 226 * force fragmentation to minimum MTU, to avoid path MTU discovery. 227 * it is too painful to ask for resend of inner packet, to achieve 228 * path MTU discovery for encapsulated packets. 229 */ 230 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 231 #else 232 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 233 #endif 234 235 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 236 sc->gif_ro6.ro_rt != NULL) { 237 RTFREE(sc->gif_ro6.ro_rt); 238 sc->gif_ro6.ro_rt = NULL; 239 } 240 241 return (error); 242 } 243 244 int 245 in6_gif_input(struct mbuf **mp, int *offp, int proto) 246 { 247 struct mbuf *m = *mp; 248 struct ifnet *gifp = NULL; 249 struct gif_softc *sc; 250 struct ip6_hdr *ip6; 251 int af = 0; 252 u_int32_t otos; 253 254 ip6 = mtod(m, struct ip6_hdr *); 255 256 sc = (struct gif_softc *)encap_getarg(m); 257 if (sc == NULL) { 258 m_freem(m); 259 ip6stat.ip6s_nogif++; 260 return IPPROTO_DONE; 261 } 262 263 gifp = GIF2IFP(sc); 264 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 265 m_freem(m); 266 ip6stat.ip6s_nogif++; 267 return IPPROTO_DONE; 268 } 269 270 otos = ip6->ip6_flow; 271 m_adj(m, *offp); 272 273 switch (proto) { 274 #ifdef INET 275 case IPPROTO_IPV4: 276 { 277 struct ip *ip; 278 u_int8_t otos8; 279 af = AF_INET; 280 otos8 = (ntohl(otos) >> 20) & 0xff; 281 if (m->m_len < sizeof(*ip)) { 282 m = m_pullup(m, sizeof(*ip)); 283 if (!m) 284 return IPPROTO_DONE; 285 } 286 ip = mtod(m, struct ip *); 287 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 288 ECN_ALLOWED : ECN_NOCARE, 289 &otos8, &ip->ip_tos) == 0) { 290 m_freem(m); 291 return IPPROTO_DONE; 292 } 293 break; 294 } 295 #endif /* INET */ 296 #ifdef INET6 297 case IPPROTO_IPV6: 298 { 299 struct ip6_hdr *ip6; 300 af = AF_INET6; 301 if (m->m_len < sizeof(*ip6)) { 302 m = m_pullup(m, sizeof(*ip6)); 303 if (!m) 304 return IPPROTO_DONE; 305 } 306 ip6 = mtod(m, struct ip6_hdr *); 307 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 308 ECN_ALLOWED : ECN_NOCARE, 309 &otos, &ip6->ip6_flow) == 0) { 310 m_freem(m); 311 return IPPROTO_DONE; 312 } 313 break; 314 } 315 #endif 316 case IPPROTO_ETHERIP: 317 af = AF_LINK; 318 break; 319 320 default: 321 ip6stat.ip6s_nogif++; 322 m_freem(m); 323 return IPPROTO_DONE; 324 } 325 326 gif_input(m, af, gifp); 327 return IPPROTO_DONE; 328 } 329 330 /* 331 * validate outer address. 332 */ 333 static int 334 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 335 struct ifnet *ifp) 336 { 337 struct sockaddr_in6 *src, *dst; 338 339 src = (struct sockaddr_in6 *)sc->gif_psrc; 340 dst = (struct sockaddr_in6 *)sc->gif_pdst; 341 342 /* 343 * Check for address match. Note that the check is for an incoming 344 * packet. We should compare the *source* address in our configuration 345 * and the *destination* address of the packet, and vice versa. 346 */ 347 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 348 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 349 return 0; 350 351 /* martian filters on outer source - done in ip6_input */ 352 353 /* ingress filters on outer source */ 354 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 355 struct sockaddr_in6 sin6; 356 struct rtentry *rt; 357 358 bzero(&sin6, sizeof(sin6)); 359 sin6.sin6_family = AF_INET6; 360 sin6.sin6_len = sizeof(struct sockaddr_in6); 361 sin6.sin6_addr = ip6->ip6_src; 362 sin6.sin6_scope_id = 0; /* XXX */ 363 364 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 365 if (!rt || rt->rt_ifp != ifp) { 366 #if 0 367 char ip6buf[INET6_ADDRSTRLEN]; 368 log(LOG_WARNING, "%s: packet from %s dropped " 369 "due to ingress filter\n", if_name(GIF2IFP(sc)), 370 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 371 #endif 372 if (rt) 373 rtfree(rt); 374 return 0; 375 } 376 rtfree(rt); 377 } 378 379 return 128 * 2; 380 } 381 382 /* 383 * we know that we are in IFF_UP, outer address available, and outer family 384 * matched the physical addr family. see gif_encapcheck(). 385 * sanity check for arg should have been done in the caller. 386 */ 387 int 388 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 389 { 390 struct ip6_hdr ip6; 391 struct gif_softc *sc; 392 struct ifnet *ifp; 393 394 /* sanity check done in caller */ 395 sc = (struct gif_softc *)arg; 396 397 /* LINTED const cast */ 398 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 399 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 400 401 return gif_validate6(&ip6, sc, ifp); 402 } 403 404 int 405 in6_gif_attach(struct gif_softc *sc) 406 { 407 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 408 (void *)&in6_gif_protosw, sc); 409 if (sc->encap_cookie6 == NULL) 410 return EEXIST; 411 return 0; 412 } 413 414 int 415 in6_gif_detach(struct gif_softc *sc) 416 { 417 int error; 418 419 error = encap_detach(sc->encap_cookie6); 420 if (error == 0) 421 sc->encap_cookie6 = NULL; 422 return error; 423 } 424