in_gif.c revision 1.37
1 /* $NetBSD: in_gif.c,v 1.37 2005/01/31 23:49:36 kim Exp $ */ 2 /* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 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 <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: in_gif.c,v 1.37 2005/01/31 23:49:36 kim Exp $"); 35 36 #include "opt_inet.h" 37 #include "opt_iso.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/ioctl.h> 46 #include <sys/syslog.h> 47 #include <sys/protosw.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 #include <net/if_gif.h> 66 67 #include "gif.h" 68 #include "bridge.h" 69 #include <net/if_ether.h> 70 71 #include <machine/stdarg.h> 72 73 #include <net/net_osdep.h> 74 75 static int gif_validate4 __P((const struct ip *, struct gif_softc *, 76 struct ifnet *)); 77 78 #if NGIF > 0 79 int ip_gif_ttl = GIF_TTL; 80 #else 81 int ip_gif_ttl = 0; 82 #endif 83 84 const struct protosw in_gif_protosw = 85 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 86 in_gif_input, rip_output, 0, rip_ctloutput, 87 rip_usrreq, 88 0, 0, 0, 0, 89 }; 90 91 int 92 in_gif_output(ifp, family, m) 93 struct ifnet *ifp; 94 int family; 95 struct mbuf *m; 96 { 97 struct gif_softc *sc = (struct gif_softc*)ifp; 98 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 99 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 100 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 101 struct ip iphdr; /* capsule IP header, host byte ordered */ 102 struct etherip_header eiphdr; 103 int proto, error; 104 u_int8_t tos; 105 106 if (sin_src == NULL || sin_dst == NULL || 107 sin_src->sin_family != AF_INET || 108 sin_dst->sin_family != AF_INET) { 109 m_freem(m); 110 return EAFNOSUPPORT; 111 } 112 113 switch (family) { 114 #ifdef INET 115 case AF_INET: 116 { 117 struct ip *ip; 118 119 proto = IPPROTO_IPV4; 120 if (m->m_len < sizeof(*ip)) { 121 m = m_pullup(m, sizeof(*ip)); 122 if (!m) 123 return ENOBUFS; 124 } 125 ip = mtod(m, struct ip *); 126 tos = ip->ip_tos; 127 break; 128 } 129 #endif /* INET */ 130 #ifdef INET6 131 case AF_INET6: 132 { 133 struct ip6_hdr *ip6; 134 proto = IPPROTO_IPV6; 135 if (m->m_len < sizeof(*ip6)) { 136 m = m_pullup(m, sizeof(*ip6)); 137 if (!m) 138 return ENOBUFS; 139 } 140 ip6 = mtod(m, struct ip6_hdr *); 141 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 142 break; 143 } 144 #endif /* INET6 */ 145 #ifdef ISO 146 case AF_ISO: 147 proto = IPPROTO_EON; 148 tos = 0; 149 break; 150 #endif 151 #if NBRIDGE > 0 152 case AF_LINK: 153 proto = IPPROTO_ETHERIP; 154 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 155 eiphdr.eip_pad = 0; 156 /* prepend Ethernet-in-IP header */ 157 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 158 if (m && m->m_len < sizeof(struct etherip_header)) 159 m = m_pullup(m, sizeof(struct etherip_header)); 160 if (m == NULL) 161 return ENOBUFS; 162 bcopy(&eiphdr, mtod(m, struct etherip_header *), sizeof(struct etherip_header)); 163 break; 164 #endif 165 default: 166 #ifdef DEBUG 167 printf("in_gif_output: warning: unknown family %d passed\n", 168 family); 169 #endif 170 m_freem(m); 171 return EAFNOSUPPORT; 172 } 173 174 bzero(&iphdr, sizeof(iphdr)); 175 iphdr.ip_src = sin_src->sin_addr; 176 /* bidirectional configured tunnel mode */ 177 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 178 iphdr.ip_dst = sin_dst->sin_addr; 179 else { 180 m_freem(m); 181 return ENETUNREACH; 182 } 183 iphdr.ip_p = proto; 184 /* version will be set in ip_output() */ 185 iphdr.ip_ttl = ip_gif_ttl; 186 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 187 if (ifp->if_flags & IFF_LINK1) 188 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 189 else 190 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 191 192 /* prepend new IP header */ 193 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 194 if (m && m->m_len < sizeof(struct ip)) 195 m = m_pullup(m, sizeof(struct ip)); 196 if (m == NULL) 197 return ENOBUFS; 198 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 199 200 if (dst->sin_family != sin_dst->sin_family || 201 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 202 /* cache route doesn't match */ 203 bzero(dst, sizeof(*dst)); 204 dst->sin_family = sin_dst->sin_family; 205 dst->sin_len = sizeof(struct sockaddr_in); 206 dst->sin_addr = sin_dst->sin_addr; 207 if (sc->gif_ro.ro_rt) { 208 RTFREE(sc->gif_ro.ro_rt); 209 sc->gif_ro.ro_rt = NULL; 210 } 211 } 212 213 if (sc->gif_ro.ro_rt == NULL) { 214 rtalloc(&sc->gif_ro); 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 } 226 227 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 228 return (error); 229 } 230 231 void 232 in_gif_input(struct mbuf *m, ...) 233 { 234 int off, proto; 235 struct ifnet *gifp = NULL; 236 struct ip *ip; 237 va_list ap; 238 int af; 239 u_int8_t otos; 240 241 va_start(ap, m); 242 off = va_arg(ap, int); 243 proto = va_arg(ap, int); 244 va_end(ap); 245 246 ip = mtod(m, struct ip *); 247 248 gifp = (struct ifnet *)encap_getarg(m); 249 250 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 251 m_freem(m); 252 ipstat.ips_nogif++; 253 return; 254 } 255 #ifndef GIF_ENCAPCHECK 256 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 257 m_freem(m); 258 ipstat.ips_nogif++; 259 return; 260 } 261 #endif 262 263 otos = ip->ip_tos; 264 m_adj(m, off); 265 266 switch (proto) { 267 #ifdef INET 268 case IPPROTO_IPV4: 269 { 270 struct ip *ip; 271 af = AF_INET; 272 if (m->m_len < sizeof(*ip)) { 273 m = m_pullup(m, sizeof(*ip)); 274 if (!m) 275 return; 276 } 277 ip = mtod(m, struct ip *); 278 if (gifp->if_flags & IFF_LINK1) 279 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 280 else 281 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 282 break; 283 } 284 #endif 285 #ifdef INET6 286 case IPPROTO_IPV6: 287 { 288 struct ip6_hdr *ip6; 289 u_int8_t itos; 290 af = AF_INET6; 291 if (m->m_len < sizeof(*ip6)) { 292 m = m_pullup(m, sizeof(*ip6)); 293 if (!m) 294 return; 295 } 296 ip6 = mtod(m, struct ip6_hdr *); 297 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 298 if (gifp->if_flags & IFF_LINK1) 299 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 300 else 301 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 302 ip6->ip6_flow &= ~htonl(0xff << 20); 303 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 304 break; 305 } 306 #endif /* INET6 */ 307 #ifdef ISO 308 case IPPROTO_EON: 309 af = AF_ISO; 310 break; 311 #endif 312 #if NBRIDGE > 0 313 case IPPROTO_ETHERIP: 314 af = AF_LINK; 315 break; 316 #endif 317 default: 318 ipstat.ips_nogif++; 319 m_freem(m); 320 return; 321 } 322 gif_input(m, af, gifp); 323 return; 324 } 325 326 /* 327 * validate outer address. 328 */ 329 static int 330 gif_validate4(ip, sc, ifp) 331 const struct ip *ip; 332 struct gif_softc *sc; 333 struct ifnet *ifp; 334 { 335 struct sockaddr_in *src, *dst; 336 struct in_ifaddr *ia4; 337 338 src = (struct sockaddr_in *)sc->gif_psrc; 339 dst = (struct sockaddr_in *)sc->gif_pdst; 340 341 /* check for address match */ 342 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 343 dst->sin_addr.s_addr != ip->ip_src.s_addr) 344 return 0; 345 346 /* martian filters on outer source - NOT done in ip_input! */ 347 if (IN_MULTICAST(ip->ip_src.s_addr)) 348 return 0; 349 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 350 case 0: case 127: case 255: 351 return 0; 352 } 353 /* reject packets with broadcast on source */ 354 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 355 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 356 continue; 357 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 358 return 0; 359 } 360 361 /* ingress filters on outer source */ 362 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 363 struct sockaddr_in sin; 364 struct rtentry *rt; 365 366 bzero(&sin, sizeof(sin)); 367 sin.sin_family = AF_INET; 368 sin.sin_len = sizeof(struct sockaddr_in); 369 sin.sin_addr = ip->ip_src; 370 rt = rtalloc1((struct sockaddr *)&sin, 0); 371 if (!rt || rt->rt_ifp != ifp) { 372 #if 0 373 log(LOG_WARNING, "%s: packet from 0x%x dropped " 374 "due to ingress filter\n", if_name(&sc->gif_if), 375 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 376 #endif 377 if (rt) 378 rtfree(rt); 379 return 0; 380 } 381 rtfree(rt); 382 } 383 384 return 32 * 2; 385 } 386 387 #ifdef GIF_ENCAPCHECK 388 /* 389 * we know that we are in IFF_UP, outer address available, and outer family 390 * matched the physical addr family. see gif_encapcheck(). 391 */ 392 int 393 gif_encapcheck4(m, off, proto, arg) 394 const struct mbuf *m; 395 int off; 396 int proto; 397 void *arg; 398 { 399 struct ip ip; 400 struct gif_softc *sc; 401 struct ifnet *ifp; 402 403 /* sanity check done in caller */ 404 sc = (struct gif_softc *)arg; 405 406 /* LINTED const cast */ 407 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 408 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 409 410 return gif_validate4(&ip, sc, ifp); 411 } 412 #endif 413 414 int 415 in_gif_attach(sc) 416 struct gif_softc *sc; 417 { 418 #ifndef GIF_ENCAPCHECK 419 struct sockaddr_in mask4; 420 421 bzero(&mask4, sizeof(mask4)); 422 mask4.sin_len = sizeof(struct sockaddr_in); 423 mask4.sin_addr.s_addr = ~0; 424 425 if (!sc->gif_psrc || !sc->gif_pdst) 426 return EINVAL; 427 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 428 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 429 (struct protosw *)&in_gif_protosw, sc); 430 #else 431 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 432 &in_gif_protosw, sc); 433 #endif 434 if (sc->encap_cookie4 == NULL) 435 return EEXIST; 436 return 0; 437 } 438 439 int 440 in_gif_detach(sc) 441 struct gif_softc *sc; 442 { 443 int error; 444 445 error = encap_detach(sc->encap_cookie4); 446 if (error == 0) 447 sc->encap_cookie4 = NULL; 448 return error; 449 } 450
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