in_gif.c revision 1.38
1 /* $NetBSD: in_gif.c,v 1.38 2005/02/01 12:56:30 he 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 1.38 2005/02/01 12:56:30 he 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 #if NBRIDGE > 0 103 struct etherip_header eiphdr; 104 #endif 105 int proto, error; 106 u_int8_t tos; 107 108 if (sin_src == NULL || sin_dst == NULL || 109 sin_src->sin_family != AF_INET || 110 sin_dst->sin_family != AF_INET) { 111 m_freem(m); 112 return EAFNOSUPPORT; 113 } 114 115 switch (family) { 116 #ifdef INET 117 case AF_INET: 118 { 119 struct ip *ip; 120 121 proto = IPPROTO_IPV4; 122 if (m->m_len < sizeof(*ip)) { 123 m = m_pullup(m, sizeof(*ip)); 124 if (!m) 125 return ENOBUFS; 126 } 127 ip = mtod(m, struct ip *); 128 tos = ip->ip_tos; 129 break; 130 } 131 #endif /* INET */ 132 #ifdef INET6 133 case AF_INET6: 134 { 135 struct ip6_hdr *ip6; 136 proto = IPPROTO_IPV6; 137 if (m->m_len < sizeof(*ip6)) { 138 m = m_pullup(m, sizeof(*ip6)); 139 if (!m) 140 return ENOBUFS; 141 } 142 ip6 = mtod(m, struct ip6_hdr *); 143 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 144 break; 145 } 146 #endif /* INET6 */ 147 #ifdef ISO 148 case AF_ISO: 149 proto = IPPROTO_EON; 150 tos = 0; 151 break; 152 #endif 153 #if NBRIDGE > 0 154 case AF_LINK: 155 proto = IPPROTO_ETHERIP; 156 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 157 eiphdr.eip_pad = 0; 158 /* prepend Ethernet-in-IP header */ 159 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 160 if (m && m->m_len < sizeof(struct etherip_header)) 161 m = m_pullup(m, sizeof(struct etherip_header)); 162 if (m == NULL) 163 return ENOBUFS; 164 bcopy(&eiphdr, mtod(m, struct etherip_header *), sizeof(struct etherip_header)); 165 break; 166 #endif 167 default: 168 #ifdef DEBUG 169 printf("in_gif_output: warning: unknown family %d passed\n", 170 family); 171 #endif 172 m_freem(m); 173 return EAFNOSUPPORT; 174 } 175 176 bzero(&iphdr, sizeof(iphdr)); 177 iphdr.ip_src = sin_src->sin_addr; 178 /* bidirectional configured tunnel mode */ 179 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 180 iphdr.ip_dst = sin_dst->sin_addr; 181 else { 182 m_freem(m); 183 return ENETUNREACH; 184 } 185 iphdr.ip_p = proto; 186 /* version will be set in ip_output() */ 187 iphdr.ip_ttl = ip_gif_ttl; 188 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 189 if (ifp->if_flags & IFF_LINK1) 190 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 191 else 192 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 193 194 /* prepend new IP header */ 195 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 196 if (m && m->m_len < sizeof(struct ip)) 197 m = m_pullup(m, sizeof(struct ip)); 198 if (m == NULL) 199 return ENOBUFS; 200 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 201 202 if (dst->sin_family != sin_dst->sin_family || 203 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 204 /* cache route doesn't match */ 205 bzero(dst, sizeof(*dst)); 206 dst->sin_family = sin_dst->sin_family; 207 dst->sin_len = sizeof(struct sockaddr_in); 208 dst->sin_addr = sin_dst->sin_addr; 209 if (sc->gif_ro.ro_rt) { 210 RTFREE(sc->gif_ro.ro_rt); 211 sc->gif_ro.ro_rt = NULL; 212 } 213 } 214 215 if (sc->gif_ro.ro_rt == NULL) { 216 rtalloc(&sc->gif_ro); 217 if (sc->gif_ro.ro_rt == NULL) { 218 m_freem(m); 219 return ENETUNREACH; 220 } 221 222 /* if it constitutes infinite encapsulation, punt. */ 223 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 224 m_freem(m); 225 return ENETUNREACH; /*XXX*/ 226 } 227 } 228 229 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 230 return (error); 231 } 232 233 void 234 in_gif_input(struct mbuf *m, ...) 235 { 236 int off, proto; 237 struct ifnet *gifp = NULL; 238 struct ip *ip; 239 va_list ap; 240 int af; 241 u_int8_t otos; 242 243 va_start(ap, m); 244 off = va_arg(ap, int); 245 proto = va_arg(ap, int); 246 va_end(ap); 247 248 ip = mtod(m, struct ip *); 249 250 gifp = (struct ifnet *)encap_getarg(m); 251 252 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 253 m_freem(m); 254 ipstat.ips_nogif++; 255 return; 256 } 257 #ifndef GIF_ENCAPCHECK 258 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 259 m_freem(m); 260 ipstat.ips_nogif++; 261 return; 262 } 263 #endif 264 265 otos = ip->ip_tos; 266 m_adj(m, off); 267 268 switch (proto) { 269 #ifdef INET 270 case IPPROTO_IPV4: 271 { 272 struct ip *ip; 273 af = AF_INET; 274 if (m->m_len < sizeof(*ip)) { 275 m = m_pullup(m, sizeof(*ip)); 276 if (!m) 277 return; 278 } 279 ip = mtod(m, struct ip *); 280 if (gifp->if_flags & IFF_LINK1) 281 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 282 else 283 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 284 break; 285 } 286 #endif 287 #ifdef INET6 288 case IPPROTO_IPV6: 289 { 290 struct ip6_hdr *ip6; 291 u_int8_t itos; 292 af = AF_INET6; 293 if (m->m_len < sizeof(*ip6)) { 294 m = m_pullup(m, sizeof(*ip6)); 295 if (!m) 296 return; 297 } 298 ip6 = mtod(m, struct ip6_hdr *); 299 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 300 if (gifp->if_flags & IFF_LINK1) 301 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 302 else 303 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 304 ip6->ip6_flow &= ~htonl(0xff << 20); 305 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 306 break; 307 } 308 #endif /* INET6 */ 309 #ifdef ISO 310 case IPPROTO_EON: 311 af = AF_ISO; 312 break; 313 #endif 314 #if NBRIDGE > 0 315 case IPPROTO_ETHERIP: 316 af = AF_LINK; 317 break; 318 #endif 319 default: 320 ipstat.ips_nogif++; 321 m_freem(m); 322 return; 323 } 324 gif_input(m, af, gifp); 325 return; 326 } 327 328 /* 329 * validate outer address. 330 */ 331 static int 332 gif_validate4(ip, sc, ifp) 333 const struct ip *ip; 334 struct gif_softc *sc; 335 struct ifnet *ifp; 336 { 337 struct sockaddr_in *src, *dst; 338 struct in_ifaddr *ia4; 339 340 src = (struct sockaddr_in *)sc->gif_psrc; 341 dst = (struct sockaddr_in *)sc->gif_pdst; 342 343 /* check for address match */ 344 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 345 dst->sin_addr.s_addr != ip->ip_src.s_addr) 346 return 0; 347 348 /* martian filters on outer source - NOT done in ip_input! */ 349 if (IN_MULTICAST(ip->ip_src.s_addr)) 350 return 0; 351 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 352 case 0: case 127: case 255: 353 return 0; 354 } 355 /* reject packets with broadcast on source */ 356 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 357 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 358 continue; 359 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 360 return 0; 361 } 362 363 /* ingress filters on outer source */ 364 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 365 struct sockaddr_in sin; 366 struct rtentry *rt; 367 368 bzero(&sin, sizeof(sin)); 369 sin.sin_family = AF_INET; 370 sin.sin_len = sizeof(struct sockaddr_in); 371 sin.sin_addr = ip->ip_src; 372 rt = rtalloc1((struct sockaddr *)&sin, 0); 373 if (!rt || rt->rt_ifp != ifp) { 374 #if 0 375 log(LOG_WARNING, "%s: packet from 0x%x dropped " 376 "due to ingress filter\n", if_name(&sc->gif_if), 377 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 378 #endif 379 if (rt) 380 rtfree(rt); 381 return 0; 382 } 383 rtfree(rt); 384 } 385 386 return 32 * 2; 387 } 388 389 #ifdef GIF_ENCAPCHECK 390 /* 391 * we know that we are in IFF_UP, outer address available, and outer family 392 * matched the physical addr family. see gif_encapcheck(). 393 */ 394 int 395 gif_encapcheck4(m, off, proto, arg) 396 const struct mbuf *m; 397 int off; 398 int proto; 399 void *arg; 400 { 401 struct ip ip; 402 struct gif_softc *sc; 403 struct ifnet *ifp; 404 405 /* sanity check done in caller */ 406 sc = (struct gif_softc *)arg; 407 408 /* LINTED const cast */ 409 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 410 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 411 412 return gif_validate4(&ip, sc, ifp); 413 } 414 #endif 415 416 int 417 in_gif_attach(sc) 418 struct gif_softc *sc; 419 { 420 #ifndef GIF_ENCAPCHECK 421 struct sockaddr_in mask4; 422 423 bzero(&mask4, sizeof(mask4)); 424 mask4.sin_len = sizeof(struct sockaddr_in); 425 mask4.sin_addr.s_addr = ~0; 426 427 if (!sc->gif_psrc || !sc->gif_pdst) 428 return EINVAL; 429 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 430 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 431 (struct protosw *)&in_gif_protosw, sc); 432 #else 433 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 434 &in_gif_protosw, sc); 435 #endif 436 if (sc->encap_cookie4 == NULL) 437 return EEXIST; 438 return 0; 439 } 440 441 int 442 in_gif_detach(sc) 443 struct gif_softc *sc; 444 { 445 int error; 446 447 error = encap_detach(sc->encap_cookie4); 448 if (error == 0) 449 sc->encap_cookie4 = NULL; 450 return error; 451 } 452
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