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 .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_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 90 &ip_gif_ttl, 0, ""); 91 92 int 93 in_gif_output(ifp, family, m) 94 struct ifnet *ifp; 95 int family; 96 struct mbuf *m; 97 { 98 struct gif_softc *sc = ifp->if_softc; 99 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 100 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 101 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 102 struct ip iphdr; /* capsule IP header, host byte ordered */ 103 struct etherip_header eiphdr; 104 int proto, error; 105 u_int8_t tos; 106 107 GIF_LOCK_ASSERT(sc); 108 109 if (sin_src == NULL || sin_dst == NULL || 110 sin_src->sin_family != AF_INET || 111 sin_dst->sin_family != AF_INET) { 112 m_freem(m); 113 return EAFNOSUPPORT; 114 } 115 116 switch (family) { 117 #ifdef INET 118 case AF_INET: 119 { 120 struct ip *ip; 121 122 proto = IPPROTO_IPV4; 123 if (m->m_len < sizeof(*ip)) { 124 m = m_pullup(m, sizeof(*ip)); 125 if (!m) 126 return ENOBUFS; 127 } 128 ip = mtod(m, struct ip *); 129 tos = ip->ip_tos; 130 break; 131 } 132 #endif /* INET */ 133 #ifdef INET6 134 case AF_INET6: 135 { 136 struct ip6_hdr *ip6; 137 proto = IPPROTO_IPV6; 138 if (m->m_len < sizeof(*ip6)) { 139 m = m_pullup(m, sizeof(*ip6)); 140 if (!m) 141 return ENOBUFS; 142 } 143 ip6 = mtod(m, struct ip6_hdr *); 144 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 145 break; 146 } 147 #endif /* INET6 */ 148 case AF_LINK: 149 proto = IPPROTO_ETHERIP; 150 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 151 eiphdr.eip_pad = 0; 152 /* prepend Ethernet-in-IP header */ 153 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 154 if (m && m->m_len < sizeof(struct etherip_header)) 155 m = m_pullup(m, sizeof(struct etherip_header)); 156 if (m == NULL) 157 return ENOBUFS; 158 bcopy(&eiphdr, mtod(m, struct etherip_header *), 159 sizeof(struct etherip_header)); 160 break; 161 162 default: 163 #ifdef DEBUG 164 printf("in_gif_output: warning: unknown family %d passed\n", 165 family); 166 #endif 167 m_freem(m); 168 return EAFNOSUPPORT; 169 } 170 171 bzero(&iphdr, sizeof(iphdr)); 172 iphdr.ip_src = sin_src->sin_addr; 173 /* bidirectional configured tunnel mode */ 174 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 175 iphdr.ip_dst = sin_dst->sin_addr; 176 else { 177 m_freem(m); 178 return ENETUNREACH; 179 } 180 iphdr.ip_p = proto; 181 /* version will be set in ip_output() */ 182 iphdr.ip_ttl = ip_gif_ttl; 183 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 184 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 185 &iphdr.ip_tos, &tos); 186 187 /* prepend new IP header */ 188 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 189 if (m && m->m_len < sizeof(struct ip)) 190 m = m_pullup(m, sizeof(struct ip)); 191 if (m == NULL) { 192 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 193 return ENOBUFS; 194 } 195 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 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 rtalloc_ign(&sc->gif_ro, 0); 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(m, off) 244 struct mbuf *m; 245 int off; 246 { 247 struct ifnet *gifp = NULL; 248 struct gif_softc *sc; 249 struct ip *ip; 250 int af; 251 u_int8_t otos; 252 int proto; 253 254 ip = mtod(m, struct ip *); 255 proto = ip->ip_p; 256 257 sc = (struct gif_softc *)encap_getarg(m); 258 if (sc == NULL) { 259 m_freem(m); 260 ipstat.ips_nogif++; 261 return; 262 } 263 264 gifp = GIF2IFP(sc); 265 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 266 m_freem(m); 267 ipstat.ips_nogif++; 268 return; 269 } 270 271 otos = ip->ip_tos; 272 m_adj(m, off); 273 274 switch (proto) { 275 #ifdef INET 276 case IPPROTO_IPV4: 277 { 278 struct ip *ip; 279 af = AF_INET; 280 if (m->m_len < sizeof(*ip)) { 281 m = m_pullup(m, sizeof(*ip)); 282 if (!m) 283 return; 284 } 285 ip = mtod(m, struct ip *); 286 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 287 ECN_ALLOWED : ECN_NOCARE, 288 &otos, &ip->ip_tos) == 0) { 289 m_freem(m); 290 return; 291 } 292 break; 293 } 294 #endif 295 #ifdef INET6 296 case IPPROTO_IPV6: 297 { 298 struct ip6_hdr *ip6; 299 u_int8_t itos, oitos; 300 301 af = AF_INET6; 302 if (m->m_len < sizeof(*ip6)) { 303 m = m_pullup(m, sizeof(*ip6)); 304 if (!m) 305 return; 306 } 307 ip6 = mtod(m, struct ip6_hdr *); 308 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 309 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 310 ECN_ALLOWED : ECN_NOCARE, 311 &otos, &itos) == 0) { 312 m_freem(m); 313 return; 314 } 315 if (itos != oitos) { 316 ip6->ip6_flow &= ~htonl(0xff << 20); 317 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 318 } 319 break; 320 } 321 #endif /* INET6 */ 322 case IPPROTO_ETHERIP: 323 af = AF_LINK; 324 break; 325 326 default: 327 ipstat.ips_nogif++; 328 m_freem(m); 329 return; 330 } 331 gif_input(m, af, gifp); 332 return; 333 } 334 335 /* 336 * validate outer address. 337 */ 338 static int 339 gif_validate4(ip, sc, ifp) 340 const struct ip *ip; 341 struct gif_softc *sc; 342 struct ifnet *ifp; 343 { 344 struct sockaddr_in *src, *dst; 345 struct in_ifaddr *ia4; 346 347 src = (struct sockaddr_in *)sc->gif_psrc; 348 dst = (struct sockaddr_in *)sc->gif_pdst; 349 350 /* check for address match */ 351 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 352 dst->sin_addr.s_addr != ip->ip_src.s_addr) 353 return 0; 354 355 /* martian filters on outer source - NOT done in ip_input! */ 356 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 357 return 0; 358 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 359 case 0: case 127: case 255: 360 return 0; 361 } 362 /* reject packets with broadcast on source */ 363 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) { 364 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 365 continue; 366 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 367 return 0; 368 } 369 370 /* ingress filters on outer source */ 371 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 372 struct sockaddr_in sin; 373 struct rtentry *rt; 374 375 bzero(&sin, sizeof(sin)); 376 sin.sin_family = AF_INET; 377 sin.sin_len = sizeof(struct sockaddr_in); 378 sin.sin_addr = ip->ip_src; 379 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 380 if (!rt || rt->rt_ifp != ifp) { 381 #if 0 382 log(LOG_WARNING, "%s: packet from 0x%x dropped " 383 "due to ingress filter\n", if_name(GIF2IFP(sc)), 384 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 385 #endif 386 if (rt) 387 rtfree(rt); 388 return 0; 389 } 390 rtfree(rt); 391 } 392 393 return 32 * 2; 394 } 395 396 /* 397 * we know that we are in IFF_UP, outer address available, and outer family 398 * matched the physical addr family. see gif_encapcheck(). 399 */ 400 int 401 gif_encapcheck4(m, off, proto, arg) 402 const struct mbuf *m; 403 int off; 404 int proto; 405 void *arg; 406 { 407 struct ip ip; 408 struct gif_softc *sc; 409 struct ifnet *ifp; 410 411 /* sanity check done in caller */ 412 sc = (struct gif_softc *)arg; 413 414 /* LINTED const cast */ 415 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 416 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 417 418 return gif_validate4(&ip, sc, ifp); 419 } 420 421 int 422 in_gif_attach(sc) 423 struct gif_softc *sc; 424 { 425 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 426 &in_gif_protosw, sc); 427 if (sc->encap_cookie4 == NULL) 428 return EEXIST; 429 return 0; 430 } 431 432 int 433 in_gif_detach(sc) 434 struct gif_softc *sc; 435 { 436 int error; 437 438 error = encap_detach(sc->encap_cookie4); 439 if (error == 0) 440 sc->encap_cookie4 = NULL; 441 return error; 442 } 443