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 error, len, proto; 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 len = sizeof(struct ip6_hdr); 170 #ifndef __NO_STRICT_ALIGNMENT 171 if (family == AF_LINK) 172 len += ETHERIP_ALIGN; 173 #endif 174 M_PREPEND(m, len, M_DONTWAIT); 175 if (m != NULL && m->m_len < len) 176 m = m_pullup(m, len); 177 if (m == NULL) { 178 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 179 return ENOBUFS; 180 } 181 #ifndef __NO_STRICT_ALIGNMENT 182 if (family == AF_LINK) { 183 len = mtod(m, vm_offset_t) & 3; 184 KASSERT(len == 0 || len == ETHERIP_ALIGN, 185 ("in6_gif_output: unexpected misalignment")); 186 m->m_data += len; 187 m->m_len -= ETHERIP_ALIGN; 188 } 189 #endif 190 191 ip6 = mtod(m, struct ip6_hdr *); 192 ip6->ip6_flow = 0; 193 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 194 ip6->ip6_vfc |= IPV6_VERSION; 195 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 196 ip6->ip6_nxt = proto; 197 ip6->ip6_hlim = V_ip6_gif_hlim; 198 ip6->ip6_src = sin6_src->sin6_addr; 199 /* bidirectional configured tunnel mode */ 200 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 201 ip6->ip6_dst = sin6_dst->sin6_addr; 202 else { 203 m_freem(m); 204 return ENETUNREACH; 205 } 206 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 207 &otos, &itos); 208 ip6->ip6_flow &= ~htonl(0xff << 20); 209 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 210 211 if (dst->sin6_family != sin6_dst->sin6_family || 212 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 213 /* cache route doesn't match */ 214 bzero(dst, sizeof(*dst)); 215 dst->sin6_family = sin6_dst->sin6_family; 216 dst->sin6_len = sizeof(struct sockaddr_in6); 217 dst->sin6_addr = sin6_dst->sin6_addr; 218 if (sc->gif_ro6.ro_rt) { 219 RTFREE(sc->gif_ro6.ro_rt); 220 sc->gif_ro6.ro_rt = NULL; 221 } 222 #if 0 223 GIF2IFP(sc)->if_mtu = GIF_MTU; 224 #endif 225 } 226 227 if (sc->gif_ro6.ro_rt == NULL) { 228 rtalloc((struct route *)&sc->gif_ro6); 229 if (sc->gif_ro6.ro_rt == NULL) { 230 m_freem(m); 231 return ENETUNREACH; 232 } 233 234 /* if it constitutes infinite encapsulation, punt. */ 235 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 236 m_freem(m); 237 return ENETUNREACH; /*XXX*/ 238 } 239 #if 0 240 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 241 - sizeof(struct ip6_hdr); 242 #endif 243 } 244 245 #ifdef IPV6_MINMTU 246 /* 247 * force fragmentation to minimum MTU, to avoid path MTU discovery. 248 * it is too painful to ask for resend of inner packet, to achieve 249 * path MTU discovery for encapsulated packets. 250 */ 251 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 252 #else 253 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 254 #endif 255 256 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 257 sc->gif_ro6.ro_rt != NULL) { 258 RTFREE(sc->gif_ro6.ro_rt); 259 sc->gif_ro6.ro_rt = NULL; 260 } 261 262 return (error); 263 } 264 265 int 266 in6_gif_input(struct mbuf **mp, int *offp, int proto) 267 { 268 INIT_VNET_INET6(curvnet); 269 struct mbuf *m = *mp; 270 struct ifnet *gifp = NULL; 271 struct gif_softc *sc; 272 struct ip6_hdr *ip6; 273 int af = 0; 274 u_int32_t otos; 275 276 ip6 = mtod(m, struct ip6_hdr *); 277 278 sc = (struct gif_softc *)encap_getarg(m); 279 if (sc == NULL) { 280 m_freem(m); 281 V_ip6stat.ip6s_nogif++; 282 return IPPROTO_DONE; 283 } 284 285 gifp = GIF2IFP(sc); 286 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 287 m_freem(m); 288 V_ip6stat.ip6s_nogif++; 289 return IPPROTO_DONE; 290 } 291 292 otos = ip6->ip6_flow; 293 m_adj(m, *offp); 294 295 switch (proto) { 296 #ifdef INET 297 case IPPROTO_IPV4: 298 { 299 struct ip *ip; 300 u_int8_t otos8; 301 af = AF_INET; 302 otos8 = (ntohl(otos) >> 20) & 0xff; 303 if (m->m_len < sizeof(*ip)) { 304 m = m_pullup(m, sizeof(*ip)); 305 if (!m) 306 return IPPROTO_DONE; 307 } 308 ip = mtod(m, struct ip *); 309 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 310 ECN_ALLOWED : ECN_NOCARE, 311 &otos8, &ip->ip_tos) == 0) { 312 m_freem(m); 313 return IPPROTO_DONE; 314 } 315 break; 316 } 317 #endif /* INET */ 318 #ifdef INET6 319 case IPPROTO_IPV6: 320 { 321 struct ip6_hdr *ip6; 322 af = AF_INET6; 323 if (m->m_len < sizeof(*ip6)) { 324 m = m_pullup(m, sizeof(*ip6)); 325 if (!m) 326 return IPPROTO_DONE; 327 } 328 ip6 = mtod(m, struct ip6_hdr *); 329 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 330 ECN_ALLOWED : ECN_NOCARE, 331 &otos, &ip6->ip6_flow) == 0) { 332 m_freem(m); 333 return IPPROTO_DONE; 334 } 335 break; 336 } 337 #endif 338 case IPPROTO_ETHERIP: 339 af = AF_LINK; 340 break; 341 342 default: 343 V_ip6stat.ip6s_nogif++; 344 m_freem(m); 345 return IPPROTO_DONE; 346 } 347 348 gif_input(m, af, gifp); 349 return IPPROTO_DONE; 350 } 351 352 /* 353 * validate outer address. 354 */ 355 static int 356 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 357 struct ifnet *ifp) 358 { 359 struct sockaddr_in6 *src, *dst; 360 361 src = (struct sockaddr_in6 *)sc->gif_psrc; 362 dst = (struct sockaddr_in6 *)sc->gif_pdst; 363 364 /* 365 * Check for address match. Note that the check is for an incoming 366 * packet. We should compare the *source* address in our configuration 367 * and the *destination* address of the packet, and vice versa. 368 */ 369 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 370 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 371 return 0; 372 373 /* martian filters on outer source - done in ip6_input */ 374 375 /* ingress filters on outer source */ 376 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 377 struct sockaddr_in6 sin6; 378 struct rtentry *rt; 379 380 bzero(&sin6, sizeof(sin6)); 381 sin6.sin6_family = AF_INET6; 382 sin6.sin6_len = sizeof(struct sockaddr_in6); 383 sin6.sin6_addr = ip6->ip6_src; 384 sin6.sin6_scope_id = 0; /* XXX */ 385 386 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 387 if (!rt || rt->rt_ifp != ifp) { 388 #if 0 389 char ip6buf[INET6_ADDRSTRLEN]; 390 log(LOG_WARNING, "%s: packet from %s dropped " 391 "due to ingress filter\n", if_name(GIF2IFP(sc)), 392 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 393 #endif 394 if (rt) 395 RTFREE_LOCKED(rt); 396 return 0; 397 } 398 RTFREE_LOCKED(rt); 399 } 400 401 return 128 * 2; 402 } 403 404 /* 405 * we know that we are in IFF_UP, outer address available, and outer family 406 * matched the physical addr family. see gif_encapcheck(). 407 * sanity check for arg should have been done in the caller. 408 */ 409 int 410 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 411 { 412 struct ip6_hdr ip6; 413 struct gif_softc *sc; 414 struct ifnet *ifp; 415 416 /* sanity check done in caller */ 417 sc = (struct gif_softc *)arg; 418 419 /* LINTED const cast */ 420 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 421 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 422 423 return gif_validate6(&ip6, sc, ifp); 424 } 425 426 int 427 in6_gif_attach(struct gif_softc *sc) 428 { 429 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 430 (void *)&in6_gif_protosw, sc); 431 if (sc->encap_cookie6 == NULL) 432 return EEXIST; 433 return 0; 434 } 435 436 int 437 in6_gif_detach(struct gif_softc *sc) 438 { 439 int error; 440 441 error = encap_detach(sc->encap_cookie6); 442 if (error == 0) 443 sc->encap_cookie6 = NULL; 444 return error; 445 } 446