1 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */ 2 3 /*- 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_mrouting.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/socket.h> 42 #include <sys/sockio.h> 43 #include <sys/mbuf.h> 44 #include <sys/errno.h> 45 #include <sys/kernel.h> 46 #include <sys/sysctl.h> 47 #include <sys/protosw.h> 48 #include <sys/malloc.h> 49 #include <sys/vimage.h> 50 51 #include <net/if.h> 52 #include <net/route.h> 53 54 #include <netinet/in.h> 55 #include <netinet/in_systm.h> 56 #include <netinet/ip.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/in_gif.h> 59 #include <netinet/in_var.h> 60 #include <netinet/ip_encap.h> 61 #include <netinet/ip_ecn.h> 62 63 #ifdef INET6 64 #include <netinet/ip6.h> 65 #endif 66 67 #ifdef MROUTING 68 #include <netinet/ip_mroute.h> 69 #endif /* MROUTING */ 70 71 #include <net/if_gif.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 .pr_type = SOCK_RAW, 79 .pr_domain = &inetdomain, 80 .pr_protocol = 0/* IPPROTO_IPV[46] */, 81 .pr_flags = PR_ATOMIC|PR_ADDR, 82 .pr_input = in_gif_input, 83 .pr_output = (pr_output_t*)rip_output, 84 .pr_ctloutput = rip_ctloutput, 85 .pr_usrreqs = &rip_usrreqs 86 }; 87 88 static int ip_gif_ttl = GIF_TTL; 89 SYSCTL_V_INT(V_NET, vnet_gif, _net_inet_ip, IPCTL_GIF_TTL, gifttl, 90 CTLFLAG_RW, ip_gif_ttl, 0, ""); 91 92 int 93 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 94 { 95 INIT_VNET_GIF(ifp->if_vnet); 96 struct gif_softc *sc = ifp->if_softc; 97 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 98 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 99 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 100 struct ip iphdr; /* capsule IP header, host byte ordered */ 101 struct etherip_header eiphdr; 102 int proto, error; 103 u_int8_t tos; 104 105 GIF_LOCK_ASSERT(sc); 106 107 if (sin_src == NULL || sin_dst == NULL || 108 sin_src->sin_family != AF_INET || 109 sin_dst->sin_family != AF_INET) { 110 m_freem(m); 111 return EAFNOSUPPORT; 112 } 113 114 switch (family) { 115 #ifdef INET 116 case AF_INET: 117 { 118 struct ip *ip; 119 120 proto = IPPROTO_IPV4; 121 if (m->m_len < sizeof(*ip)) { 122 m = m_pullup(m, sizeof(*ip)); 123 if (!m) 124 return ENOBUFS; 125 } 126 ip = mtod(m, struct ip *); 127 tos = ip->ip_tos; 128 break; 129 } 130 #endif /* INET */ 131 #ifdef INET6 132 case AF_INET6: 133 { 134 struct ip6_hdr *ip6; 135 proto = IPPROTO_IPV6; 136 if (m->m_len < sizeof(*ip6)) { 137 m = m_pullup(m, sizeof(*ip6)); 138 if (!m) 139 return ENOBUFS; 140 } 141 ip6 = mtod(m, struct ip6_hdr *); 142 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 143 break; 144 } 145 #endif /* INET6 */ 146 case AF_LINK: 147 proto = IPPROTO_ETHERIP; 148 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 149 eiphdr.eip_pad = 0; 150 /* prepend Ethernet-in-IP header */ 151 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 152 if (m && m->m_len < sizeof(struct etherip_header)) 153 m = m_pullup(m, sizeof(struct etherip_header)); 154 if (m == NULL) 155 return ENOBUFS; 156 bcopy(&eiphdr, mtod(m, struct etherip_header *), 157 sizeof(struct etherip_header)); 158 break; 159 160 default: 161 #ifdef DEBUG 162 printf("in_gif_output: warning: unknown family %d passed\n", 163 family); 164 #endif 165 m_freem(m); 166 return EAFNOSUPPORT; 167 } 168 169 bzero(&iphdr, sizeof(iphdr)); 170 iphdr.ip_src = sin_src->sin_addr; 171 /* bidirectional configured tunnel mode */ 172 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 173 iphdr.ip_dst = sin_dst->sin_addr; 174 else { 175 m_freem(m); 176 return ENETUNREACH; 177 } 178 iphdr.ip_p = proto; 179 /* version will be set in ip_output() */ 180 iphdr.ip_ttl = V_ip_gif_ttl; 181 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 182 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 183 &iphdr.ip_tos, &tos); 184 185 /* prepend new IP header */ 186 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 187 if (m && m->m_len < sizeof(struct ip)) 188 m = m_pullup(m, sizeof(struct ip)); 189 if (m == NULL) { 190 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 191 return ENOBUFS; 192 } 193 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 194 195 M_SETFIB(m, sc->gif_fibnum); 196 197 if (dst->sin_family != sin_dst->sin_family || 198 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 199 /* cache route doesn't match */ 200 bzero(dst, sizeof(*dst)); 201 dst->sin_family = sin_dst->sin_family; 202 dst->sin_len = sizeof(struct sockaddr_in); 203 dst->sin_addr = sin_dst->sin_addr; 204 if (sc->gif_ro.ro_rt) { 205 RTFREE(sc->gif_ro.ro_rt); 206 sc->gif_ro.ro_rt = NULL; 207 } 208 #if 0 209 GIF2IFP(sc)->if_mtu = GIF_MTU; 210 #endif 211 } 212 213 if (sc->gif_ro.ro_rt == NULL) { 214 in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum); 215 if (sc->gif_ro.ro_rt == NULL) { 216 m_freem(m); 217 return ENETUNREACH; 218 } 219 220 /* if it constitutes infinite encapsulation, punt. */ 221 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 222 m_freem(m); 223 return ENETUNREACH; /* XXX */ 224 } 225 #if 0 226 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 227 - sizeof(struct ip); 228 #endif 229 } 230 231 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 232 233 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 234 sc->gif_ro.ro_rt != NULL) { 235 RTFREE(sc->gif_ro.ro_rt); 236 sc->gif_ro.ro_rt = NULL; 237 } 238 239 return (error); 240 } 241 242 void 243 in_gif_input(struct mbuf *m, int off) 244 { 245 INIT_VNET_INET(curvnet); 246 struct ifnet *gifp = NULL; 247 struct gif_softc *sc; 248 struct ip *ip; 249 int af; 250 u_int8_t otos; 251 int proto; 252 253 ip = mtod(m, struct ip *); 254 proto = ip->ip_p; 255 256 sc = (struct gif_softc *)encap_getarg(m); 257 if (sc == NULL) { 258 m_freem(m); 259 V_ipstat.ips_nogif++; 260 return; 261 } 262 263 gifp = GIF2IFP(sc); 264 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 265 m_freem(m); 266 V_ipstat.ips_nogif++; 267 return; 268 } 269 270 otos = ip->ip_tos; 271 m_adj(m, off); 272 273 switch (proto) { 274 #ifdef INET 275 case IPPROTO_IPV4: 276 { 277 struct ip *ip; 278 af = AF_INET; 279 if (m->m_len < sizeof(*ip)) { 280 m = m_pullup(m, sizeof(*ip)); 281 if (!m) 282 return; 283 } 284 ip = mtod(m, struct ip *); 285 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 286 ECN_ALLOWED : ECN_NOCARE, 287 &otos, &ip->ip_tos) == 0) { 288 m_freem(m); 289 return; 290 } 291 break; 292 } 293 #endif 294 #ifdef INET6 295 case IPPROTO_IPV6: 296 { 297 struct ip6_hdr *ip6; 298 u_int8_t itos, oitos; 299 300 af = AF_INET6; 301 if (m->m_len < sizeof(*ip6)) { 302 m = m_pullup(m, sizeof(*ip6)); 303 if (!m) 304 return; 305 } 306 ip6 = mtod(m, struct ip6_hdr *); 307 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 308 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 309 ECN_ALLOWED : ECN_NOCARE, 310 &otos, &itos) == 0) { 311 m_freem(m); 312 return; 313 } 314 if (itos != oitos) { 315 ip6->ip6_flow &= ~htonl(0xff << 20); 316 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 317 } 318 break; 319 } 320 #endif /* INET6 */ 321 case IPPROTO_ETHERIP: 322 af = AF_LINK; 323 break; 324 325 default: 326 V_ipstat.ips_nogif++; 327 m_freem(m); 328 return; 329 } 330 gif_input(m, af, gifp); 331 return; 332 } 333 334 /* 335 * validate outer address. 336 */ 337 static int 338 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 339 { 340 INIT_VNET_INET(curvnet); 341 struct sockaddr_in *src, *dst; 342 struct in_ifaddr *ia4; 343 344 src = (struct sockaddr_in *)sc->gif_psrc; 345 dst = (struct sockaddr_in *)sc->gif_pdst; 346 347 /* check for address match */ 348 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 349 dst->sin_addr.s_addr != ip->ip_src.s_addr) 350 return 0; 351 352 /* martian filters on outer source - NOT done in ip_input! */ 353 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 354 return 0; 355 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 356 case 0: case 127: case 255: 357 return 0; 358 } 359 /* reject packets with broadcast on source */ 360 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 361 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 362 continue; 363 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 364 return 0; 365 } 366 367 /* ingress filters on outer source */ 368 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 369 struct sockaddr_in sin; 370 struct rtentry *rt; 371 372 bzero(&sin, sizeof(sin)); 373 sin.sin_family = AF_INET; 374 sin.sin_len = sizeof(struct sockaddr_in); 375 sin.sin_addr = ip->ip_src; 376 /* XXX MRT check for the interface we would use on output */ 377 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 378 0UL, sc->gif_fibnum); 379 if (!rt || rt->rt_ifp != ifp) { 380 #if 0 381 log(LOG_WARNING, "%s: packet from 0x%x dropped " 382 "due to ingress filter\n", if_name(GIF2IFP(sc)), 383 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 384 #endif 385 if (rt) 386 RTFREE_LOCKED(rt); 387 return 0; 388 } 389 RTFREE_LOCKED(rt); 390 } 391 392 return 32 * 2; 393 } 394 395 /* 396 * we know that we are in IFF_UP, outer address available, and outer family 397 * matched the physical addr family. see gif_encapcheck(). 398 */ 399 int 400 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 401 { 402 struct ip ip; 403 struct gif_softc *sc; 404 struct ifnet *ifp; 405 406 /* sanity check done in caller */ 407 sc = (struct gif_softc *)arg; 408 409 /* LINTED const cast */ 410 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 411 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 412 413 return gif_validate4(&ip, sc, ifp); 414 } 415 416 int 417 in_gif_attach(struct gif_softc *sc) 418 { 419 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 420 &in_gif_protosw, sc); 421 if (sc->encap_cookie4 == NULL) 422 return EEXIST; 423 return 0; 424 } 425 426 int 427 in_gif_detach(struct gif_softc *sc) 428 { 429 int error; 430 431 error = encap_detach(sc->encap_cookie4); 432 if (error == 0) 433 sc->encap_cookie4 = NULL; 434 return error; 435 } 436