1 /* $FreeBSD$ */ 2 /* $KAME: in6_gif.c,v 1.37 2000/06/17 20:34:25 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 /* 34 * in6_gif.c 35 */ 36 37 #include "opt_inet.h" 38 #include "opt_inet6.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/mbuf.h> 45 #include <sys/errno.h> 46 47 #include <net/if.h> 48 #include <net/route.h> 49 50 #include <netinet/in.h> 51 #include <netinet/in_systm.h> 52 #ifdef INET 53 #include <netinet/ip.h> 54 #endif 55 #include <netinet/ip_encap.h> 56 #ifdef INET6 57 #include <netinet/ip6.h> 58 #include <netinet6/ip6_var.h> 59 #include <netinet6/in6_gif.h> 60 #include <netinet6/in6_var.h> 61 #endif 62 #include <netinet/ip_ecn.h> 63 #ifdef INET6 64 #include <netinet6/ip6_ecn.h> 65 #endif 66 67 #include <net/if_gif.h> 68 69 #include <net/net_osdep.h> 70 71 #ifndef offsetof 72 #define offsetof(s, e) ((int)&((s *)0)->e) 73 #endif 74 75 int 76 in6_gif_output(ifp, family, m, rt) 77 struct ifnet *ifp; 78 int family; /* family of the packet to be encapsulate. */ 79 struct mbuf *m; 80 struct rtentry *rt; 81 { 82 struct gif_softc *sc = (struct gif_softc*)ifp; 83 struct sockaddr_in6 *dst = (struct sockaddr_in6 *)&sc->gif_ro6.ro_dst; 84 struct sockaddr_in6 *sin6_src = (struct sockaddr_in6 *)sc->gif_psrc; 85 struct sockaddr_in6 *sin6_dst = (struct sockaddr_in6 *)sc->gif_pdst; 86 struct ip6_hdr *ip6; 87 int proto; 88 u_int8_t itos, otos; 89 90 if (sin6_src == NULL || sin6_dst == NULL || 91 sin6_src->sin6_family != AF_INET6 || 92 sin6_dst->sin6_family != AF_INET6) { 93 m_freem(m); 94 return EAFNOSUPPORT; 95 } 96 97 switch (family) { 98 #ifdef INET 99 case AF_INET: 100 { 101 struct ip *ip; 102 103 proto = IPPROTO_IPV4; 104 if (m->m_len < sizeof(*ip)) { 105 m = m_pullup(m, sizeof(*ip)); 106 if (!m) 107 return ENOBUFS; 108 } 109 ip = mtod(m, struct ip *); 110 itos = ip->ip_tos; 111 break; 112 } 113 #endif 114 #ifdef INET6 115 case AF_INET6: 116 { 117 struct ip6_hdr *ip6; 118 proto = IPPROTO_IPV6; 119 if (m->m_len < sizeof(*ip6)) { 120 m = m_pullup(m, sizeof(*ip6)); 121 if (!m) 122 return ENOBUFS; 123 } 124 ip6 = mtod(m, struct ip6_hdr *); 125 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 126 break; 127 } 128 #endif 129 default: 130 #ifdef DEBUG 131 printf("in6_gif_output: warning: unknown family %d passed\n", 132 family); 133 #endif 134 m_freem(m); 135 return EAFNOSUPPORT; 136 } 137 138 /* prepend new IP header */ 139 M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT); 140 if (m && m->m_len < sizeof(struct ip6_hdr)) 141 m = m_pullup(m, sizeof(struct ip6_hdr)); 142 if (m == NULL) { 143 printf("ENOBUFS in in6_gif_output %d\n", __LINE__); 144 return ENOBUFS; 145 } 146 147 ip6 = mtod(m, struct ip6_hdr *); 148 ip6->ip6_flow = 0; 149 ip6->ip6_vfc &= ~IPV6_VERSION_MASK; 150 ip6->ip6_vfc |= IPV6_VERSION; 151 ip6->ip6_plen = htons((u_short)m->m_pkthdr.len); 152 ip6->ip6_nxt = proto; 153 ip6->ip6_hlim = ip6_gif_hlim; 154 ip6->ip6_src = sin6_src->sin6_addr; 155 if (ifp->if_flags & IFF_LINK0) { 156 /* multi-destination mode */ 157 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 158 ip6->ip6_dst = sin6_dst->sin6_addr; 159 else if (rt) { 160 if (family != AF_INET6) { 161 m_freem(m); 162 return EINVAL; /*XXX*/ 163 } 164 ip6->ip6_dst = ((struct sockaddr_in6 *)(rt->rt_gateway))->sin6_addr; 165 } else { 166 m_freem(m); 167 return ENETUNREACH; 168 } 169 } else { 170 /* bidirectional configured tunnel mode */ 171 if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) 172 ip6->ip6_dst = sin6_dst->sin6_addr; 173 else { 174 m_freem(m); 175 return ENETUNREACH; 176 } 177 } 178 if (ifp->if_flags & IFF_LINK1) { 179 otos = 0; 180 ip_ecn_ingress(ECN_ALLOWED, &otos, &itos); 181 ip6->ip6_flow |= htonl((u_int32_t)otos << 20); 182 } 183 184 if (dst->sin6_family != sin6_dst->sin6_family || 185 !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &sin6_dst->sin6_addr)) { 186 /* cache route doesn't match */ 187 bzero(dst, sizeof(*dst)); 188 dst->sin6_family = sin6_dst->sin6_family; 189 dst->sin6_len = sizeof(struct sockaddr_in6); 190 dst->sin6_addr = sin6_dst->sin6_addr; 191 if (sc->gif_ro6.ro_rt) { 192 RTFREE(sc->gif_ro6.ro_rt); 193 sc->gif_ro6.ro_rt = NULL; 194 } 195 #if 0 196 sc->gif_if.if_mtu = GIF_MTU; 197 #endif 198 } 199 200 if (sc->gif_ro6.ro_rt == NULL) { 201 rtalloc((struct route *)&sc->gif_ro6); 202 if (sc->gif_ro6.ro_rt == NULL) { 203 m_freem(m); 204 return ENETUNREACH; 205 } 206 207 /* if it constitutes infinite encapsulation, punt. */ 208 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 209 m_freem(m); 210 return ENETUNREACH; /*XXX*/ 211 } 212 #if 0 213 ifp->if_mtu = sc->gif_ro6.ro_rt->rt_ifp->if_mtu 214 - sizeof(struct ip6_hdr); 215 #endif 216 } 217 218 #ifdef IPV6_MINMTU 219 /* 220 * force fragmentation to minimum MTU, to avoid path MTU discovery. 221 * it is too painful to ask for resend of inner packet, to achieve 222 * path MTU discovery for encapsulated packets. 223 */ 224 return(ip6_output(m, 0, &sc->gif_ro6, IPV6_MINMTU, 0, NULL)); 225 #else 226 return(ip6_output(m, 0, &sc->gif_ro6, 0, 0, NULL)); 227 #endif 228 } 229 230 int in6_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 (gifp->if_flags & IFF_LINK1) 268 ip_ecn_egress(ECN_ALLOWED, &otos8, &ip->ip_tos); 269 break; 270 } 271 #endif /* INET */ 272 #ifdef INET6 273 case IPPROTO_IPV6: 274 { 275 struct ip6_hdr *ip6; 276 af = AF_INET6; 277 if (m->m_len < sizeof(*ip6)) { 278 m = m_pullup(m, sizeof(*ip6)); 279 if (!m) 280 return IPPROTO_DONE; 281 } 282 ip6 = mtod(m, struct ip6_hdr *); 283 if (gifp->if_flags & IFF_LINK1) 284 ip6_ecn_egress(ECN_ALLOWED, &otos, &ip6->ip6_flow); 285 break; 286 } 287 #endif 288 default: 289 ip6stat.ip6s_nogif++; 290 m_freem(m); 291 return IPPROTO_DONE; 292 } 293 294 gif_input(m, af, gifp); 295 return IPPROTO_DONE; 296 } 297 298 /* 299 * we know that we are in IFF_UP, outer address available, and outer family 300 * matched the physical addr family. see gif_encapcheck(). 301 */ 302 int 303 gif_encapcheck6(m, off, proto, arg) 304 const struct mbuf *m; 305 int off; 306 int proto; 307 void *arg; 308 { 309 struct ip6_hdr ip6; 310 struct gif_softc *sc; 311 struct sockaddr_in6 *src, *dst; 312 int addrmatch; 313 314 /* sanity check done in caller */ 315 sc = (struct gif_softc *)arg; 316 src = (struct sockaddr_in6 *)sc->gif_psrc; 317 dst = (struct sockaddr_in6 *)sc->gif_pdst; 318 319 /* LINTED const cast */ 320 m_copydata((struct mbuf *)m, 0, sizeof(ip6), (caddr_t)&ip6); 321 322 /* check for address match */ 323 addrmatch = 0; 324 if (IN6_ARE_ADDR_EQUAL(&src->sin6_addr, &ip6.ip6_dst)) 325 addrmatch |= 1; 326 if (IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6.ip6_src)) 327 addrmatch |= 2; 328 else if ((sc->gif_if.if_flags & IFF_LINK0) != 0 && 329 IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) { 330 addrmatch |= 2; /* we accept any source */ 331 } 332 if (addrmatch != 3) 333 return 0; 334 335 /* martian filters on outer source - done in ip6_input */ 336 337 /* ingress filters on outer source */ 338 if ((m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) { 339 struct sockaddr_in6 sin6; 340 struct rtentry *rt; 341 342 bzero(&sin6, sizeof(sin6)); 343 sin6.sin6_family = AF_INET6; 344 sin6.sin6_len = sizeof(struct sockaddr_in6); 345 sin6.sin6_addr = ip6.ip6_src; 346 /* XXX scopeid */ 347 rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL); 348 if (!rt) 349 return 0; 350 if (rt->rt_ifp != m->m_pkthdr.rcvif) { 351 rtfree(rt); 352 return 0; 353 } 354 rtfree(rt); 355 } 356 357 /* prioritize: IFF_LINK0 mode is less preferred */ 358 return (sc->gif_if.if_flags & IFF_LINK0) ? 128 : 128 * 2; 359 } 360