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; 147 148 /* 149 * GIF_SEND_REVETHIP (disabled by default) intentionally 150 * sends an EtherIP packet with revered version field in 151 * the header. This is a knob for backward compatibility 152 * with FreeBSD 7.2R or prior. 153 */ 154 if ((sc->gif_options & GIF_SEND_REVETHIP)) { 155 eiphdr.eip_ver = 0; 156 eiphdr.eip_resvl = ETHERIP_VERSION; 157 eiphdr.eip_resvh = 0; 158 } else { 159 eiphdr.eip_ver = ETHERIP_VERSION; 160 eiphdr.eip_resvl = 0; 161 eiphdr.eip_resvh = 0; 162 } 163 /* prepend Ethernet-in-IP header */ 164 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 165 if (m && m->m_len < sizeof(struct etherip_header)) 166 m = m_pullup(m, sizeof(struct etherip_header)); 167 if (m == NULL) 168 return ENOBUFS; 169 bcopy(&eiphdr, mtod(m, struct etherip_header *), 170 sizeof(struct etherip_header)); 171 break; 172 173 default: 174 #ifdef DEBUG 175 printf("in6_gif_output: warning: unknown family %d passed\n", 176 family); 177 #endif 178 m_freem(m); 179 return EAFNOSUPPORT; 180 } 181 182 /* prepend new IP header */ 183 len = sizeof(struct ip6_hdr); 184 #ifndef __NO_STRICT_ALIGNMENT 185 if (family == AF_LINK) 186 len += ETHERIP_ALIGN; 187 #endif 188 M_PREPEND(m, len, M_DONTWAIT); 189 if (m != NULL && m->m_len < len) 190 m = m_pullup(m, len); 191 if (m == NULL) { 192 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 193 return ENOBUFS; 194 } 195 #ifndef __NO_STRICT_ALIGNMENT 196 if (family == AF_LINK) { 197 len = mtod(m, vm_offset_t) & 3; 198 KASSERT(len == 0 || len == ETHERIP_ALIGN, 199 ("in6_gif_output: unexpected misalignment")); 200 m->m_data += len; 201 m->m_len -= ETHERIP_ALIGN; 202 } 203 #endif 204 205 ip6 = mtod(m, struct ip6_hdr *); 206 ip6->ip6_flow = 0; 207 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 208 ip6->ip6_vfc |= IPV6_VERSION; 209 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 210 ip6->ip6_nxt = proto; 211 ip6->ip6_hlim = V_ip6_gif_hlim; 212 ip6->ip6_src = sin6_src->sin6_addr; 213 /* bidirectional configured tunnel mode */ 214 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 215 ip6->ip6_dst = sin6_dst->sin6_addr; 216 else { 217 m_freem(m); 218 return ENETUNREACH; 219 } 220 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 221 &otos, &itos); 222 ip6->ip6_flow &= ~htonl(0xff << 20); 223 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 224 225 if (dst->sin6_family != sin6_dst->sin6_family || 226 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 227 /* cache route doesn't match */ 228 bzero(dst, sizeof(*dst)); 229 dst->sin6_family = sin6_dst->sin6_family; 230 dst->sin6_len = sizeof(struct sockaddr_in6); 231 dst->sin6_addr = sin6_dst->sin6_addr; 232 if (sc->gif_ro6.ro_rt) { 233 RTFREE(sc->gif_ro6.ro_rt); 234 sc->gif_ro6.ro_rt = NULL; 235 } 236 #if 0 237 GIF2IFP(sc)->if_mtu = GIF_MTU; 238 #endif 239 } 240 241 if (sc->gif_ro6.ro_rt == NULL) { 242 rtalloc((struct route *)&sc->gif_ro6); 243 if (sc->gif_ro6.ro_rt == NULL) { 244 m_freem(m); 245 return ENETUNREACH; 246 } 247 248 /* if it constitutes infinite encapsulation, punt. */ 249 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 250 m_freem(m); 251 return ENETUNREACH; /*XXX*/ 252 } 253 #if 0 254 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 255 - sizeof(struct ip6_hdr); 256 #endif 257 } 258 259 #ifdef IPV6_MINMTU 260 /* 261 * force fragmentation to minimum MTU, to avoid path MTU discovery. 262 * it is too painful to ask for resend of inner packet, to achieve 263 * path MTU discovery for encapsulated packets. 264 */ 265 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 266 #else 267 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 268 #endif 269 270 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 271 sc->gif_ro6.ro_rt != NULL) { 272 RTFREE(sc->gif_ro6.ro_rt); 273 sc->gif_ro6.ro_rt = NULL; 274 } 275 276 return (error); 277 } 278 279 int 280 in6_gif_input(struct mbuf **mp, int *offp, int proto) 281 { 282 INIT_VNET_INET6(curvnet); 283 struct mbuf *m = *mp; 284 struct ifnet *gifp = NULL; 285 struct gif_softc *sc; 286 struct ip6_hdr *ip6; 287 int af = 0; 288 u_int32_t otos; 289 290 ip6 = mtod(m, struct ip6_hdr *); 291 292 sc = (struct gif_softc *)encap_getarg(m); 293 if (sc == NULL) { 294 m_freem(m); 295 V_ip6stat.ip6s_nogif++; 296 return IPPROTO_DONE; 297 } 298 299 gifp = GIF2IFP(sc); 300 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 301 m_freem(m); 302 V_ip6stat.ip6s_nogif++; 303 return IPPROTO_DONE; 304 } 305 306 otos = ip6->ip6_flow; 307 m_adj(m, *offp); 308 309 switch (proto) { 310 #ifdef INET 311 case IPPROTO_IPV4: 312 { 313 struct ip *ip; 314 u_int8_t otos8; 315 af = AF_INET; 316 otos8 = (ntohl(otos) >> 20) & 0xff; 317 if (m->m_len < sizeof(*ip)) { 318 m = m_pullup(m, sizeof(*ip)); 319 if (!m) 320 return IPPROTO_DONE; 321 } 322 ip = mtod(m, struct ip *); 323 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 324 ECN_ALLOWED : ECN_NOCARE, 325 &otos8, &ip->ip_tos) == 0) { 326 m_freem(m); 327 return IPPROTO_DONE; 328 } 329 break; 330 } 331 #endif /* INET */ 332 #ifdef INET6 333 case IPPROTO_IPV6: 334 { 335 struct ip6_hdr *ip6; 336 af = AF_INET6; 337 if (m->m_len < sizeof(*ip6)) { 338 m = m_pullup(m, sizeof(*ip6)); 339 if (!m) 340 return IPPROTO_DONE; 341 } 342 ip6 = mtod(m, struct ip6_hdr *); 343 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 344 ECN_ALLOWED : ECN_NOCARE, 345 &otos, &ip6->ip6_flow) == 0) { 346 m_freem(m); 347 return IPPROTO_DONE; 348 } 349 break; 350 } 351 #endif 352 case IPPROTO_ETHERIP: 353 af = AF_LINK; 354 break; 355 356 default: 357 V_ip6stat.ip6s_nogif++; 358 m_freem(m); 359 return IPPROTO_DONE; 360 } 361 362 gif_input(m, af, gifp); 363 return IPPROTO_DONE; 364 } 365 366 /* 367 * validate outer address. 368 */ 369 static int 370 gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 371 struct ifnet *ifp) 372 { 373 struct sockaddr_in6 *src, *dst; 374 375 src = (struct sockaddr_in6 *)sc->gif_psrc; 376 dst = (struct sockaddr_in6 *)sc->gif_pdst; 377 378 /* 379 * Check for address match. Note that the check is for an incoming 380 * packet. We should compare the *source* address in our configuration 381 * and the *destination* address of the packet, and vice versa. 382 */ 383 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 384 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 385 return 0; 386 387 /* martian filters on outer source - done in ip6_input */ 388 389 /* ingress filters on outer source */ 390 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 391 struct sockaddr_in6 sin6; 392 struct rtentry *rt; 393 394 bzero(&sin6, sizeof(sin6)); 395 sin6.sin6_family = AF_INET6; 396 sin6.sin6_len = sizeof(struct sockaddr_in6); 397 sin6.sin6_addr = ip6->ip6_src; 398 sin6.sin6_scope_id = 0; /* XXX */ 399 400 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 401 if (!rt || rt->rt_ifp != ifp) { 402 #if 0 403 char ip6buf[INET6_ADDRSTRLEN]; 404 log(LOG_WARNING, "%s: packet from %s dropped " 405 "due to ingress filter\n", if_name(GIF2IFP(sc)), 406 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 407 #endif 408 if (rt) 409 RTFREE_LOCKED(rt); 410 return 0; 411 } 412 RTFREE_LOCKED(rt); 413 } 414 415 return 128 * 2; 416 } 417 418 /* 419 * we know that we are in IFF_UP, outer address available, and outer family 420 * matched the physical addr family. see gif_encapcheck(). 421 * sanity check for arg should have been done in the caller. 422 */ 423 int 424 gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 425 { 426 struct ip6_hdr ip6; 427 struct gif_softc *sc; 428 struct ifnet *ifp; 429 430 /* sanity check done in caller */ 431 sc = (struct gif_softc *)arg; 432 433 /* LINTED const cast */ 434 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 435 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 436 437 return gif_validate6(&ip6, sc, ifp); 438 } 439 440 int 441 in6_gif_attach(struct gif_softc *sc) 442 { 443 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 444 (void *)&in6_gif_protosw, sc); 445 if (sc->encap_cookie6 == NULL) 446 return EEXIST; 447 return 0; 448 } 449 450 int 451 in6_gif_detach(struct gif_softc *sc) 452 { 453 int error; 454 455 error = encap_detach(sc->encap_cookie6); 456 if (error == 0) 457 sc->encap_cookie6 = NULL; 458 return error; 459 } 460