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 49 #include <sys/malloc.h> 50 #include <sys/vimage.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/ip.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in_gif.h> 60 #include <netinet/in_var.h> 61 #include <netinet/ip_encap.h> 62 #include <netinet/ip_ecn.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #endif 67 68 #ifdef MROUTING 69 #include <netinet/ip_mroute.h> 70 #endif /* MROUTING */ 71 72 #include <net/if_gif.h> 73 74 static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77 extern struct domain inetdomain; 78 struct protosw in_gif_protosw = { 79 .pr_type = SOCK_RAW, 80 .pr_domain = &inetdomain, 81 .pr_protocol = 0/* IPPROTO_IPV[46] */, 82 .pr_flags = PR_ATOMIC|PR_ADDR, 83 .pr_input = in_gif_input, 84 .pr_output = (pr_output_t*)rip_output, 85 .pr_ctloutput = rip_ctloutput, 86 .pr_usrreqs = &rip_usrreqs 87 }; 88 89 static int ip_gif_ttl = GIF_TTL; 90 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 91 &ip_gif_ttl, 0, ""); 92 93 int 94 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 95 { 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 struct ifnet *gifp = NULL; 246 struct gif_softc *sc; 247 struct ip *ip; 248 int af; 249 u_int8_t otos; 250 int proto; 251 252 ip = mtod(m, struct ip *); 253 proto = ip->ip_p; 254 255 sc = (struct gif_softc *)encap_getarg(m); 256 if (sc == NULL) { 257 m_freem(m); 258 V_ipstat.ips_nogif++; 259 return; 260 } 261 262 gifp = GIF2IFP(sc); 263 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 264 m_freem(m); 265 V_ipstat.ips_nogif++; 266 return; 267 } 268 269 otos = ip->ip_tos; 270 m_adj(m, off); 271 272 switch (proto) { 273 #ifdef INET 274 case IPPROTO_IPV4: 275 { 276 struct ip *ip; 277 af = AF_INET; 278 if (m->m_len < sizeof(*ip)) { 279 m = m_pullup(m, sizeof(*ip)); 280 if (!m) 281 return; 282 } 283 ip = mtod(m, struct ip *); 284 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 285 ECN_ALLOWED : ECN_NOCARE, 286 &otos, &ip->ip_tos) == 0) { 287 m_freem(m); 288 return; 289 } 290 break; 291 } 292 #endif 293 #ifdef INET6 294 case IPPROTO_IPV6: 295 { 296 struct ip6_hdr *ip6; 297 u_int8_t itos, oitos; 298 299 af = AF_INET6; 300 if (m->m_len < sizeof(*ip6)) { 301 m = m_pullup(m, sizeof(*ip6)); 302 if (!m) 303 return; 304 } 305 ip6 = mtod(m, struct ip6_hdr *); 306 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 307 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 308 ECN_ALLOWED : ECN_NOCARE, 309 &otos, &itos) == 0) { 310 m_freem(m); 311 return; 312 } 313 if (itos != oitos) { 314 ip6->ip6_flow &= ~htonl(0xff << 20); 315 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 316 } 317 break; 318 } 319 #endif /* INET6 */ 320 case IPPROTO_ETHERIP: 321 af = AF_LINK; 322 break; 323 324 default: 325 V_ipstat.ips_nogif++; 326 m_freem(m); 327 return; 328 } 329 gif_input(m, af, gifp); 330 return; 331 } 332 333 /* 334 * validate outer address. 335 */ 336 static int 337 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 338 { 339 struct sockaddr_in *src, *dst; 340 struct in_ifaddr *ia4; 341 342 src = (struct sockaddr_in *)sc->gif_psrc; 343 dst = (struct sockaddr_in *)sc->gif_pdst; 344 345 /* check for address match */ 346 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 347 dst->sin_addr.s_addr != ip->ip_src.s_addr) 348 return 0; 349 350 /* martian filters on outer source - NOT done in ip_input! */ 351 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 352 return 0; 353 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 354 case 0: case 127: case 255: 355 return 0; 356 } 357 /* reject packets with broadcast on source */ 358 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 359 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 360 continue; 361 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 362 return 0; 363 } 364 365 /* ingress filters on outer source */ 366 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 367 struct sockaddr_in sin; 368 struct rtentry *rt; 369 370 bzero(&sin, sizeof(sin)); 371 sin.sin_family = AF_INET; 372 sin.sin_len = sizeof(struct sockaddr_in); 373 sin.sin_addr = ip->ip_src; 374 /* XXX MRT check for the interface we would use on output */ 375 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 376 0UL, sc->gif_fibnum); 377 if (!rt || rt->rt_ifp != ifp) { 378 #if 0 379 log(LOG_WARNING, "%s: packet from 0x%x dropped " 380 "due to ingress filter\n", if_name(GIF2IFP(sc)), 381 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 382 #endif 383 if (rt) 384 RTFREE_LOCKED(rt); 385 return 0; 386 } 387 RTFREE_LOCKED(rt); 388 } 389 390 return 32 * 2; 391 } 392 393 /* 394 * we know that we are in IFF_UP, outer address available, and outer family 395 * matched the physical addr family. see gif_encapcheck(). 396 */ 397 int 398 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 399 { 400 struct ip ip; 401 struct gif_softc *sc; 402 struct ifnet *ifp; 403 404 /* sanity check done in caller */ 405 sc = (struct gif_softc *)arg; 406 407 /* LINTED const cast */ 408 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 409 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 410 411 return gif_validate4(&ip, sc, ifp); 412 } 413 414 int 415 in_gif_attach(struct gif_softc *sc) 416 { 417 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 418 &in_gif_protosw, sc); 419 if (sc->encap_cookie4 == NULL) 420 return EEXIST; 421 return 0; 422 } 423 424 int 425 in_gif_detach(struct gif_softc *sc) 426 { 427 int error; 428 429 error = encap_detach(sc->encap_cookie4); 430 if (error == 0) 431 sc->encap_cookie4 = NULL; 432 return error; 433 } 434