in6_gif.c revision 138619
1/* $FreeBSD: head/sys/netinet6/in6_gif.c 138619 2004-12-09 09:48:47Z glebius $ */ 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#include <net/net_osdep.h> 72 73static int gif_validate6(const struct ip6_hdr *, struct gif_softc *, 74 struct ifnet *); 75 76extern struct domain inet6domain; 77struct 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 85int 86in6_gif_output(ifp, family, m) 87 struct ifnet *ifp; 88 int family; /* family of the packet to be encapsulate. */ 89 struct mbuf *m; 90{ 91 struct gif_softc *sc = (struct gif_softc*)ifp; 92 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 93 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 94 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 95 struct ip6_hdr *ip6; 96 int proto, error; 97 u_int8_t itos, otos; 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 default: 139#ifdef DEBUG 140 printf("in6_gif_output: warning: unknown family %d passed\n", 141 family); 142#endif 143 m_freem(m); 144 return EAFNOSUPPORT; 145 } 146 147 /* prepend new IP header */ 148 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 149 if (m && m->m_len < sizeof(struct ip6_hdr)) 150 m = m_pullup(m, sizeof(struct ip6_hdr)); 151 if (m == NULL) { 152 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 153 return ENOBUFS; 154 } 155 156 ip6 = mtod(m, struct ip6_hdr *); 157 ip6->ip6_flow = 0; 158 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 159 ip6->ip6_vfc |= IPV6_VERSION; 160 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 161 ip6->ip6_nxt = proto; 162 ip6->ip6_hlim = ip6_gif_hlim; 163 ip6->ip6_src = sin6_src->sin6_addr; 164 /* bidirectional configured tunnel mode */ 165 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 166 ip6->ip6_dst = sin6_dst->sin6_addr; 167 else { 168 m_freem(m); 169 return ENETUNREACH; 170 } 171 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 172 &otos, &itos); 173 ip6->ip6_flow &= ~htonl(0xff << 20); 174 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 175 176 if (dst->sin6_family != sin6_dst->sin6_family || 177 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 178 /* cache route doesn't match */ 179 bzero(dst, sizeof(*dst)); 180 dst->sin6_family = sin6_dst->sin6_family; 181 dst->sin6_len = sizeof(struct sockaddr_in6); 182 dst->sin6_addr = sin6_dst->sin6_addr; 183 if (sc->gif_ro6.ro_rt) { 184 RTFREE(sc->gif_ro6.ro_rt); 185 sc->gif_ro6.ro_rt = NULL; 186 } 187#if 0 188 sc->gif_if.if_mtu = GIF_MTU; 189#endif 190 } 191 192 if (sc->gif_ro6.ro_rt == NULL) { 193 rtalloc((struct route *)&sc->gif_ro6); 194 if (sc->gif_ro6.ro_rt == NULL) { 195 m_freem(m); 196 return ENETUNREACH; 197 } 198 199 /* if it constitutes infinite encapsulation, punt. */ 200 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 201 m_freem(m); 202 return ENETUNREACH; /*XXX*/ 203 } 204#if 0 205 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 206 - sizeof(struct ip6_hdr); 207#endif 208 } 209 210#ifdef IPV6_MINMTU 211 /* 212 * force fragmentation to minimum MTU, to avoid path MTU discovery. 213 * it is too painful to ask for resend of inner packet, to achieve 214 * path MTU discovery for encapsulated packets. 215 */ 216 error = (ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL, NULL)); 217#else 218 error = (ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL, NULL)); 219#endif 220 221 if ((sc->gif_if.if_flags & IFF_LINK0) == 0) { 222 RTFREE(sc->gif_ro6.ro_rt); 223 sc->gif_ro6.ro_rt = NULL; 224 } 225 226 return (error); 227} 228 229int 230in6_gif_input(mp, offp, proto) 231 struct mbuf **mp; 232 int *offp, proto; 233{ 234 struct mbuf *m = *mp; 235 struct ifnet *gifp = NULL; 236 struct ip6_hdr *ip6; 237 int af = 0; 238 u_int32_t otos; 239 240 ip6 = mtod(m, struct ip6_hdr *); 241 242 gifp = (struct ifnet *)encap_getarg(m); 243 244 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 245 m_freem(m); 246 ip6stat.ip6s_nogif++; 247 return IPPROTO_DONE; 248 } 249 250 otos = ip6->ip6_flow; 251 m_adj(m, *offp); 252 253 switch (proto) { 254#ifdef INET 255 case IPPROTO_IPV4: 256 { 257 struct ip *ip; 258 u_int8_t otos8; 259 af = AF_INET; 260 otos8 = (ntohl(otos) >> 20) & 0xff; 261 if (m->m_len < sizeof(*ip)) { 262 m = m_pullup(m, sizeof(*ip)); 263 if (!m) 264 return IPPROTO_DONE; 265 } 266 ip = mtod(m, struct ip *); 267 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 268 ECN_ALLOWED : ECN_NOCARE, 269 &otos8, &ip->ip_tos) == 0) { 270 m_freem(m); 271 return IPPROTO_DONE; 272 } 273 break; 274 } 275#endif /* INET */ 276#ifdef INET6 277 case IPPROTO_IPV6: 278 { 279 struct ip6_hdr *ip6; 280 af = AF_INET6; 281 if (m->m_len < sizeof(*ip6)) { 282 m = m_pullup(m, sizeof(*ip6)); 283 if (!m) 284 return IPPROTO_DONE; 285 } 286 ip6 = mtod(m, struct ip6_hdr *); 287 if (ip6_ecn_egress((gifp->if_flags & IFF_LINK1) ? 288 ECN_ALLOWED : ECN_NOCARE, 289 &otos, &ip6->ip6_flow) == 0) { 290 m_freem(m); 291 return IPPROTO_DONE; 292 } 293 break; 294 } 295#endif 296 default: 297 ip6stat.ip6s_nogif++; 298 m_freem(m); 299 return IPPROTO_DONE; 300 } 301 302 gif_input(m, af, gifp); 303 return IPPROTO_DONE; 304} 305 306/* 307 * validate outer address. 308 */ 309static int 310gif_validate6(ip6, sc, ifp) 311 const struct ip6_hdr *ip6; 312 struct gif_softc *sc; 313 struct ifnet *ifp; 314{ 315 struct sockaddr_in6 *src, *dst; 316 317 src = (struct sockaddr_in6 *)sc->gif_psrc; 318 dst = (struct sockaddr_in6 *)sc->gif_pdst; 319 320 /* 321 * Check for address match. Note that the check is for an incoming 322 * packet. We should compare the *source* address in our configuration 323 * and the *destination* address of the packet, and vice versa. 324 */ 325 if (!IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6->ip6_dst) || 326 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_src)) 327 return 0; 328 329 /* martian filters on outer source - done in ip6_input */ 330 331 /* ingress filters on outer source */ 332 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 333 struct sockaddr_in6 sin6; 334 struct rtentry *rt; 335 336 bzero(&sin6, sizeof(sin6)); 337 sin6.sin6_family = AF_INET6; 338 sin6.sin6_len = sizeof(struct sockaddr_in6); 339 sin6.sin6_addr = ip6->ip6_src; 340 sin6.sin6_scope_id = 0; /* XXX */ 341 342 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 343 if (!rt || rt->rt_ifp != ifp) { 344#if 0 345 log(LOG_WARNING, "%s: packet from %s dropped " 346 "due to ingress filter\n", if_name(&sc->gif_if), 347 ip6_sprintf(&sin6.sin6_addr)); 348#endif 349 if (rt) 350 rtfree(rt); 351 return 0; 352 } 353 rtfree(rt); 354 } 355 356 return 128 * 2; 357} 358 359/* 360 * we know that we are in IFF_UP, outer address available, and outer family 361 * matched the physical addr family. see gif_encapcheck(). 362 * sanity check for arg should have been done in the caller. 363 */ 364int 365gif_encapcheck6(m, off, proto, arg) 366 const struct mbuf *m; 367 int off; 368 int proto; 369 void *arg; 370{ 371 struct ip6_hdr ip6; 372 struct gif_softc *sc; 373 struct ifnet *ifp; 374 375 /* sanity check done in caller */ 376 sc = (struct gif_softc *)arg; 377 378 /* LINTED const cast */ 379 m_copydata(m, 0, sizeof(ip6), (caddr_t)&ip6); 380 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 381 382 return gif_validate6(&ip6, sc, ifp); 383} 384 385int 386in6_gif_attach(sc) 387 struct gif_softc *sc; 388{ 389 sc->encap_cookie6 = encap_attach_func(AF_INET6, -1, gif_encapcheck, 390 (struct protosw *)&in6_gif_protosw, sc); 391 if (sc->encap_cookie6 == NULL) 392 return EEXIST; 393 return 0; 394} 395 396int 397in6_gif_detach(sc) 398 struct gif_softc *sc; 399{ 400 int error; 401 402 error = encap_detach(sc->encap_cookie6); 403 if (error == 0) 404 sc->encap_cookie6 = NULL; 405 return error; 406} 407