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>
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81static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 82 struct ifnet *); 83 84extern struct domain inet6domain; 85struct ip6protosw in6_gif_protosw = { 86 .pr_type = SOCK_RAW, 87 .pr_domain = &inet6domain, 88 .pr_protocol = 0, /* IPPROTO_IPV[46] */ 89 .pr_flags = PR_ATOMIC|PR_ADDR, 90 .pr_input = in6_gif_input, 91 .pr_output = rip6_output, 92 .pr_ctloutput = rip6_ctloutput, 93 .pr_usrreqs = &rip6_usrreqs 94}; 95 96int 97in6_gif_output(struct ifnet *ifp, 98 int family, /* family of the packet to be encapsulate */ 99 struct mbuf *m) 100{ 101 struct gif_softc *sc = ifp->if_softc; 102 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 103 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 104 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 105 struct ip6_hdr *ip6; 106 struct etherip_header eiphdr; 107 int error, len, proto; 108 u_int8_t itos, otos; 109 110 GIF_LOCK_ASSERT(sc); 111 112 if (sin6_src == NULL || sin6_dst == NULL || 113 sin6_src->sin6_family != AF_INET6 || 114 sin6_dst->sin6_family != AF_INET6) { 115 m_freem(m); 116 return EAFNOSUPPORT; 117 } 118 119 switch (family) { 120#ifdef INET 121 case AF_INET: 122 { 123 struct ip *ip; 124 125 proto = IPPROTO_IPV4; 126 if (m->m_len < sizeof(*ip)) { 127 m = m_pullup(m, sizeof(*ip)); 128 if (!m) 129 return ENOBUFS; 130 } 131 ip = mtod(m, struct ip *); 132 itos = ip->ip_tos; 133 break; 134 } 135#endif 136#ifdef INET6 137 case AF_INET6: 138 { 139 struct ip6_hdr *ip6; 140 proto = IPPROTO_IPV6; 141 if (m->m_len < sizeof(*ip6)) { 142 m = m_pullup(m, sizeof(*ip6)); 143 if (!m) 144 return ENOBUFS; 145 } 146 ip6 = mtod(m, struct ip6_hdr *); 147 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 148 break; 149 } 150#endif 151 case AF_LINK: 152 proto = IPPROTO_ETHERIP; 153 154 /* 155 * GIF_SEND_REVETHIP (disabled by default) intentionally 156 * sends an EtherIP packet with revered version field in 157 * the header. This is a knob for backward compatibility 158 * with FreeBSD 7.2R or prior. 159 */ 160 if ((sc->gif_options & GIF_SEND_REVETHIP)) { 161 eiphdr.eip_ver = 0; 162 eiphdr.eip_resvl = ETHERIP_VERSION; 163 eiphdr.eip_resvh = 0; 164 } else { 165 eiphdr.eip_ver = ETHERIP_VERSION; 166 eiphdr.eip_resvl = 0; 167 eiphdr.eip_resvh = 0; 168 } 169 /* prepend Ethernet-in-IP header */ 170 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 171 if (m && m->m_len < sizeof(struct etherip_header)) 172 m = m_pullup(m, sizeof(struct etherip_header)); 173 if (m == NULL) 174 return ENOBUFS; 175 bcopy(&eiphdr, mtod(m, struct etherip_header *), 176 sizeof(struct etherip_header)); 177 break; 178 179 default: 180#ifdef DEBUG 181 printf("in6_gif_output: warning: unknown family %d passed\n", 182 family); 183#endif 184 m_freem(m); 185 return EAFNOSUPPORT; 186 } 187 188 /* prepend new IP header */ 189 len = sizeof(struct ip6_hdr); 190#ifndef __NO_STRICT_ALIGNMENT 191 if (family == AF_LINK) 192 len += ETHERIP_ALIGN; 193#endif 194 M_PREPEND(m, len, M_DONTWAIT); 195 if (m != NULL && m->m_len < len) 196 m = m_pullup(m, len); 197 if (m == NULL) { 198 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 199 return ENOBUFS; 200 } 201#ifndef __NO_STRICT_ALIGNMENT 202 if (family == AF_LINK) { 203 len = mtod(m, vm_offset_t) & 3; 204 KASSERT(len == 0 || len == ETHERIP_ALIGN, 205 ("in6_gif_output: unexpected misalignment")); 206 m->m_data += len; 207 m->m_len -= ETHERIP_ALIGN; 208 } 209#endif 210 211 ip6 = mtod(m, struct ip6_hdr *); 212 ip6->ip6_flow = 0; 213 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 214 ip6->ip6_vfc |= IPV6_VERSION; 215 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 216 ip6->ip6_nxt = proto; 217 ip6->ip6_hlim = V_ip6_gif_hlim; 218 ip6->ip6_src = sin6_src->sin6_addr; 219 /* bidirectional configured tunnel mode */ 220 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 221 ip6->ip6_dst = sin6_dst->sin6_addr; 222 else { 223 m_freem(m); 224 return ENETUNREACH; 225 } 226 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 227 &otos, &itos); 228 ip6->ip6_flow &= ~htonl(0xff << 20); 229 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 230 231 if (dst->sin6_family != sin6_dst->sin6_family || 232 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 233 /* cache route doesn't match */ 234 bzero(dst, sizeof(*dst)); 235 dst->sin6_family = sin6_dst->sin6_family; 236 dst->sin6_len = sizeof(struct sockaddr_in6); 237 dst->sin6_addr = sin6_dst->sin6_addr; 238 if (sc->gif_ro6.ro_rt) { 239 RTFREE(sc->gif_ro6.ro_rt); 240 sc->gif_ro6.ro_rt = NULL; 241 } 242#if 0 243 GIF2IFP(sc)->if_mtu = GIF_MTU; 244#endif 245 } 246 247 if (sc->gif_ro6.ro_rt == NULL) { 248 rtalloc((struct route *)&sc->gif_ro6); 249 if (sc->gif_ro6.ro_rt == NULL) { 250 m_freem(m); 251 return ENETUNREACH; 252 } 253 254 /* if it constitutes infinite encapsulation, punt. */ 255 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 256 m_freem(m); 257 return ENETUNREACH; /*XXX*/ 258 } 259#if 0 260 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 261 - sizeof(struct ip6_hdr); 262#endif 263 } 264 265#ifdef IPV6_MINMTU 266 /* 267 * force fragmentation to minimum MTU, to avoid path MTU discovery. 268 * it is too painful to ask for resend of inner packet, to achieve 269 * path MTU discovery for encapsulated packets. 270 */ 271 error = ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL); 272#else 273 error = ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL); 274#endif 275 276 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 277 sc->gif_ro6.ro_rt != NULL) { 278 RTFREE(sc->gif_ro6.ro_rt); 279 sc->gif_ro6.ro_rt = NULL; 280 } 281 282 return (error); 283} 284 285int 286in6_gif_input(struct mbuf **mp, int *offp, int proto) 287{ 288 struct mbuf *m = *mp; 289 struct ifnet *gifp = NULL; 290 struct gif_softc *sc; 291 struct ip6_hdr *ip6; 292 int af = 0; 293 u_int32_t otos; 294 295 ip6 = mtod(m, struct ip6_hdr *); 296 297 sc = (struct gif_softc *)encap_getarg(m); 298 if (sc == NULL) { 299 m_freem(m); 300 V_ip6stat.ip6s_nogif++; 301 return IPPROTO_DONE; 302 } 303 304 gifp = GIF2IFP(sc); 305 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 306 m_freem(m); 307 V_ip6stat.ip6s_nogif++; 308 return IPPROTO_DONE; 309 } 310 311 otos = ip6->ip6_flow; 312 m_adj(m, *offp); 313 314 switch (proto) { 315#ifdef INET 316 case IPPROTO_IPV4: 317 { 318 struct ip *ip; 319 u_int8_t otos8; 320 af = AF_INET; 321 otos8 = (ntohl(otos) >> 20) & 0xff; 322 if (m->m_len < sizeof(*ip)) { 323 m = m_pullup(m, sizeof(*ip)); 324 if (!m) 325 return IPPROTO_DONE; 326 } 327 ip = mtod(m, struct ip *); 328 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 329 ECN_ALLOWED : ECN_NOCARE, 330 &otos8, &ip->ip_tos) == 0) { 331 m_freem(m); 332 return IPPROTO_DONE; 333 } 334 break; 335 } 336#endif /* INET */ 337#ifdef INET6 338 case IPPROTO_IPV6: 339 { 340 struct ip6_hdr *ip6; 341 af = AF_INET6; 342 if (m->m_len < sizeof(*ip6)) { 343 m = m_pullup(m, sizeof(*ip6)); 344 if (!m) 345 return IPPROTO_DONE; 346 } 347 ip6 = mtod(m, struct ip6_hdr *); 348 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 349 ECN_ALLOWED : ECN_NOCARE, 350 &otos, &ip6->ip6_flow) == 0) { 351 m_freem(m); 352 return IPPROTO_DONE; 353 } 354 break; 355 } 356#endif 357 case IPPROTO_ETHERIP: 358 af = AF_LINK; 359 break; 360 361 default: 362 V_ip6stat.ip6s_nogif++; 363 m_freem(m); 364 return IPPROTO_DONE; 365 } 366 367 gif_input(m, af, gifp); 368 return IPPROTO_DONE; 369} 370 371/* 372 * validate outer address. 373 */ 374static int 375gif_validate6(const struct ip6_hdr *ip6, struct gif_softc *sc, 376 struct ifnet *ifp) 377{ 378 struct sockaddr_in6 *src, *dst; 379 380 src = (struct sockaddr_in6 *)sc->gif_psrc; 381 dst = (struct sockaddr_in6 *)sc->gif_pdst; 382 383 /* 384 * Check for address match. Note that the check is for an incoming 385 * packet. We should compare the *source* address in our configuration 386 * and the *destination* address of the packet, and vice versa. 387 */ 388 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 389 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 390 return 0; 391 392 /* martian filters on outer source - done in ip6_input */ 393 394 /* ingress filters on outer source */ 395 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 396 struct sockaddr_in6 sin6; 397 struct rtentry *rt; 398 399 bzero(&sin6, sizeof(sin6)); 400 sin6.sin6_family = AF_INET6; 401 sin6.sin6_len = sizeof(struct sockaddr_in6); 402 sin6.sin6_addr = ip6->ip6_src; 403 sin6.sin6_scope_id = 0; /* XXX */ 404 405 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 406 if (!rt || rt->rt_ifp != ifp) { 407#if 0 408 char ip6buf[INET6_ADDRSTRLEN]; 409 log(LOG_WARNING, "%s: packet from %s dropped " 410 "due to ingress filter\n", if_name(GIF2IFP(sc)), 411 ip6_sprintf(ip6buf, &sin6.sin6_addr)); 412#endif 413 if (rt) 414 RTFREE_LOCKED(rt); 415 return 0; 416 } 417 RTFREE_LOCKED(rt); 418 } 419 420 return 128 * 2; 421} 422 423/* 424 * we know that we are in IFF_UP, outer address available, and outer family 425 * matched the physical addr family. see gif_encapcheck(). 426 * sanity check for arg should have been done in the caller. 427 */ 428int 429gif_encapcheck6(const struct mbuf *m, int off, int proto, void *arg) 430{ 431 struct ip6_hdr ip6; 432 struct gif_softc *sc; 433 struct ifnet *ifp; 434 435 /* sanity check done in caller */ 436 sc = (struct gif_softc *)arg; 437 438 /* LINTED const cast */ 439 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 440 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 441 442 return gif_validate6(&ip6, sc, ifp); 443} 444 445int 446in6_gif_attach(struct gif_softc *sc) 447{ 448 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 449 (void *)&in6_gif_protosw, sc); 450 if (sc->encap_cookie6 == NULL) 451 return EEXIST; 452 return 0; 453} 454 455int 456in6_gif_detach(struct gif_softc *sc) 457{ 458 int error; 459 460 error = encap_detach(sc->encap_cookie6); 461 if (error == 0) 462 sc->encap_cookie6 = NULL; 463 return error; 464}
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