1 /* $FreeBSD$ */ 2 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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_mrouting.h" 34 #include "opt_inet.h" 35 #include "opt_inet6.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/socket.h> 40 #include <sys/sockio.h> 41 #include <sys/mbuf.h> 42 #include <sys/errno.h> 43 #include <sys/kernel.h> 44 #include <sys/sysctl.h> 45 #include <sys/protosw.h> 46 47 #include <sys/malloc.h> 48 49 #include <net/if.h> 50 #include <net/route.h> 51 52 #include <netinet/in.h> 53 #include <netinet/in_systm.h> 54 #include <netinet/ip.h> 55 #include <netinet/ip_var.h> 56 #include <netinet/in_gif.h> 57 #include <netinet/in_var.h> 58 #include <netinet/ip_encap.h> 59 #include <netinet/ip_ecn.h> 60 61 #ifdef INET6 62 #include <netinet/ip6.h> 63 #endif 64 65 #ifdef MROUTING 66 #include <netinet/ip_mroute.h> 67 #endif /* MROUTING */ 68 69 #include <net/if_gif.h> 70 71 #include <net/net_osdep.h> 72 73 static int gif_validate4(const struct ip *, struct gif_softc *, 74 struct ifnet *); 75 76 extern struct domain inetdomain; 77 struct protosw in_gif_protosw = 78 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 79 in_gif_input, (pr_output_t*)rip_output, 0, rip_ctloutput, 80 0, 81 0, 0, 0, 0, 82 &rip_usrreqs 83 }; 84 85 static int ip_gif_ttl = GIF_TTL; 86 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 87 &ip_gif_ttl, 0, ""); 88 89 int 90 in_gif_output(ifp, family, m) 91 struct ifnet *ifp; 92 int family; 93 struct mbuf *m; 94 { 95 struct gif_softc *sc = (struct gif_softc*)ifp; 96 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 97 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 98 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 99 struct ip iphdr; /* capsule IP header, host byte ordered */ 100 int proto, error; 101 u_int8_t tos; 102 103 if (sin_src == NULL || sin_dst == NULL || 104 sin_src->sin_family != AF_INET || 105 sin_dst->sin_family != AF_INET) { 106 m_freem(m); 107 return EAFNOSUPPORT; 108 } 109 110 switch (family) { 111 #ifdef INET 112 case AF_INET: 113 { 114 struct ip *ip; 115 116 proto = IPPROTO_IPV4; 117 if (m->m_len < sizeof(*ip)) { 118 m = m_pullup(m, sizeof(*ip)); 119 if (!m) 120 return ENOBUFS; 121 } 122 ip = mtod(m, struct ip *); 123 tos = ip->ip_tos; 124 break; 125 } 126 #endif /* INET */ 127 #ifdef INET6 128 case AF_INET6: 129 { 130 struct ip6_hdr *ip6; 131 proto = IPPROTO_IPV6; 132 if (m->m_len < sizeof(*ip6)) { 133 m = m_pullup(m, sizeof(*ip6)); 134 if (!m) 135 return ENOBUFS; 136 } 137 ip6 = mtod(m, struct ip6_hdr *); 138 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 139 break; 140 } 141 #endif /* INET6 */ 142 default: 143 #ifdef DEBUG 144 printf("in_gif_output: warning: unknown family %d passed\n", 145 family); 146 #endif 147 m_freem(m); 148 return EAFNOSUPPORT; 149 } 150 151 bzero(&iphdr, sizeof(iphdr)); 152 iphdr.ip_src = sin_src->sin_addr; 153 /* bidirectional configured tunnel mode */ 154 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 155 iphdr.ip_dst = sin_dst->sin_addr; 156 else { 157 m_freem(m); 158 return ENETUNREACH; 159 } 160 iphdr.ip_p = proto; 161 /* version will be set in ip_output() */ 162 iphdr.ip_ttl = ip_gif_ttl; 163 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 164 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 165 &iphdr.ip_tos, &tos); 166 167 /* prepend new IP header */ 168 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 169 if (m && m->m_len < sizeof(struct ip)) 170 m = m_pullup(m, sizeof(struct ip)); 171 if (m == NULL) { 172 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 173 return ENOBUFS; 174 } 175 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 176 177 if (dst->sin_family != sin_dst->sin_family || 178 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 179 /* cache route doesn't match */ 180 bzero(dst, sizeof(*dst)); 181 dst->sin_family = sin_dst->sin_family; 182 dst->sin_len = sizeof(struct sockaddr_in); 183 dst->sin_addr = sin_dst->sin_addr; 184 if (sc->gif_ro.ro_rt) { 185 RTFREE(sc->gif_ro.ro_rt); 186 sc->gif_ro.ro_rt = NULL; 187 } 188 #if 0 189 sc->gif_if.if_mtu = GIF_MTU; 190 #endif 191 } 192 193 if (sc->gif_ro.ro_rt == NULL) { 194 rtalloc_ign(&sc->gif_ro, 0); 195 if (sc->gif_ro.ro_rt == NULL) { 196 m_freem(m); 197 return ENETUNREACH; 198 } 199 200 /* if it constitutes infinite encapsulation, punt. */ 201 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 202 m_freem(m); 203 return ENETUNREACH; /* XXX */ 204 } 205 #if 0 206 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 207 - sizeof(struct ip); 208 #endif 209 } 210 211 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 212 return (error); 213 } 214 215 void 216 in_gif_input(m, off) 217 struct mbuf *m; 218 int off; 219 { 220 struct ifnet *gifp = NULL; 221 struct ip *ip; 222 int af; 223 u_int8_t otos; 224 int proto; 225 226 ip = mtod(m, struct ip *); 227 proto = ip->ip_p; 228 229 gifp = (struct ifnet *)encap_getarg(m); 230 231 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 232 m_freem(m); 233 ipstat.ips_nogif++; 234 return; 235 } 236 237 otos = ip->ip_tos; 238 m_adj(m, off); 239 240 switch (proto) { 241 #ifdef INET 242 case IPPROTO_IPV4: 243 { 244 struct ip *ip; 245 af = AF_INET; 246 if (m->m_len < sizeof(*ip)) { 247 m = m_pullup(m, sizeof(*ip)); 248 if (!m) 249 return; 250 } 251 ip = mtod(m, struct ip *); 252 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 253 ECN_ALLOWED : ECN_NOCARE, 254 &otos, &ip->ip_tos) == 0) { 255 m_freem(m); 256 return; 257 } 258 break; 259 } 260 #endif 261 #ifdef INET6 262 case IPPROTO_IPV6: 263 { 264 struct ip6_hdr *ip6; 265 u_int8_t itos, oitos; 266 267 af = AF_INET6; 268 if (m->m_len < sizeof(*ip6)) { 269 m = m_pullup(m, sizeof(*ip6)); 270 if (!m) 271 return; 272 } 273 ip6 = mtod(m, struct ip6_hdr *); 274 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 275 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 276 ECN_ALLOWED : ECN_NOCARE, 277 &otos, &itos) == 0) { 278 m_freem(m); 279 return; 280 } 281 if (itos != oitos) { 282 ip6->ip6_flow &= ~htonl(0xff << 20); 283 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 284 } 285 break; 286 } 287 #endif /* INET6 */ 288 default: 289 ipstat.ips_nogif++; 290 m_freem(m); 291 return; 292 } 293 gif_input(m, af, gifp); 294 return; 295 } 296 297 /* 298 * validate outer address. 299 */ 300 static int 301 gif_validate4(ip, sc, ifp) 302 const struct ip *ip; 303 struct gif_softc *sc; 304 struct ifnet *ifp; 305 { 306 struct sockaddr_in *src, *dst; 307 struct in_ifaddr *ia4; 308 309 src = (struct sockaddr_in *)sc->gif_psrc; 310 dst = (struct sockaddr_in *)sc->gif_pdst; 311 312 /* check for address match */ 313 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 314 dst->sin_addr.s_addr != ip->ip_src.s_addr) 315 return 0; 316 317 /* martian filters on outer source - NOT done in ip_input! */ 318 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 319 return 0; 320 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 321 case 0: case 127: case 255: 322 return 0; 323 } 324 /* reject packets with broadcast on source */ 325 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) { 326 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 327 continue; 328 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 329 return 0; 330 } 331 332 /* ingress filters on outer source */ 333 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 334 struct sockaddr_in sin; 335 struct rtentry *rt; 336 337 bzero(&sin, sizeof(sin)); 338 sin.sin_family = AF_INET; 339 sin.sin_len = sizeof(struct sockaddr_in); 340 sin.sin_addr = ip->ip_src; 341 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 342 if (!rt || rt->rt_ifp != ifp) { 343 #if 0 344 log(LOG_WARNING, "%s: packet from 0x%x dropped " 345 "due to ingress filter\n", if_name(&sc->gif_if), 346 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 347 #endif 348 if (rt) 349 rtfree(rt); 350 return 0; 351 } 352 rtfree(rt); 353 } 354 355 return 32 * 2; 356 } 357 358 /* 359 * we know that we are in IFF_UP, outer address available, and outer family 360 * matched the physical addr family. see gif_encapcheck(). 361 */ 362 int 363 gif_encapcheck4(m, off, proto, arg) 364 const struct mbuf *m; 365 int off; 366 int proto; 367 void *arg; 368 { 369 struct ip ip; 370 struct gif_softc *sc; 371 struct ifnet *ifp; 372 373 /* sanity check done in caller */ 374 sc = (struct gif_softc *)arg; 375 376 /* LINTED const cast */ 377 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 378 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 379 380 return gif_validate4(&ip, sc, ifp); 381 } 382 383 int 384 in_gif_attach(sc) 385 struct gif_softc *sc; 386 { 387 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 388 &in_gif_protosw, sc); 389 if (sc->encap_cookie4 == NULL) 390 return EEXIST; 391 return 0; 392 } 393 394 int 395 in_gif_detach(sc) 396 struct gif_softc *sc; 397 { 398 int error; 399 400 error = encap_detach(sc->encap_cookie4); 401 if (error == 0) 402 sc->encap_cookie4 = NULL; 403 return error; 404 } 405