in_gif.c revision 1.29
1 /* $NetBSD: in_gif.c,v 1.29 2002/08/14 00:23:29 itojun 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 1.29 2002/08/14 00:23:29 itojun Exp $"); 35 36 #include "opt_inet.h" 37 #include "opt_iso.h" 38 39 /* define it if you want to use encap_attach_func (it helps *BSD merge) */ 40 #define USE_ENCAPCHECK 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/socket.h> 45 #include <sys/sockio.h> 46 #include <sys/mbuf.h> 47 #include <sys/errno.h> 48 #include <sys/ioctl.h> 49 #include <sys/syslog.h> 50 #include <sys/protosw.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 #include <net/if_gif.h> 69 70 #include "gif.h" 71 72 #include <machine/stdarg.h> 73 74 #include <net/net_osdep.h> 75 76 static int gif_validate4 __P((const struct ip *, struct gif_softc *, 77 struct ifnet *)); 78 79 #if NGIF > 0 80 int ip_gif_ttl = GIF_TTL; 81 #else 82 int ip_gif_ttl = 0; 83 #endif 84 85 extern struct domain inetdomain; 86 struct protosw in_gif_protosw = 87 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 88 in_gif_input, rip_output, 0, rip_ctloutput, 89 rip_usrreq, 90 0, 0, 0, 0, 91 }; 92 93 int 94 in_gif_output(ifp, family, m) 95 struct ifnet *ifp; 96 int family; 97 struct mbuf *m; 98 { 99 struct gif_softc *sc = (struct gif_softc*)ifp; 100 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 101 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 102 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 103 struct ip iphdr; /* capsule IP header, host byte ordered */ 104 int proto, error; 105 u_int8_t tos; 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 #ifdef ISO 147 case AF_ISO: 148 proto = IPPROTO_EON; 149 tos = 0; 150 break; 151 #endif 152 default: 153 #ifdef DEBUG 154 printf("in_gif_output: warning: unknown family %d passed\n", 155 family); 156 #endif 157 m_freem(m); 158 return EAFNOSUPPORT; 159 } 160 161 bzero(&iphdr, sizeof(iphdr)); 162 iphdr.ip_src = sin_src->sin_addr; 163 /* bidirectional configured tunnel mode */ 164 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 165 iphdr.ip_dst = sin_dst->sin_addr; 166 else { 167 m_freem(m); 168 return ENETUNREACH; 169 } 170 iphdr.ip_p = proto; 171 /* version will be set in ip_output() */ 172 iphdr.ip_ttl = ip_gif_ttl; 173 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 174 if (ifp->if_flags & IFF_LINK1) 175 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 176 else 177 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 178 179 /* prepend new IP header */ 180 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 181 if (m && m->m_len < sizeof(struct ip)) 182 m = m_pullup(m, sizeof(struct ip)); 183 if (m == NULL) 184 return ENOBUFS; 185 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 186 187 if (dst->sin_family != sin_dst->sin_family || 188 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 189 /* cache route doesn't match */ 190 bzero(dst, sizeof(*dst)); 191 dst->sin_family = sin_dst->sin_family; 192 dst->sin_len = sizeof(struct sockaddr_in); 193 dst->sin_addr = sin_dst->sin_addr; 194 if (sc->gif_ro.ro_rt) { 195 RTFREE(sc->gif_ro.ro_rt); 196 sc->gif_ro.ro_rt = NULL; 197 } 198 } 199 200 if (sc->gif_ro.ro_rt == NULL) { 201 rtalloc(&sc->gif_ro); 202 if (sc->gif_ro.ro_rt == NULL) { 203 m_freem(m); 204 return ENETUNREACH; 205 } 206 207 /* if it constitutes infinite encapsulation, punt. */ 208 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 209 m_freem(m); 210 return ENETUNREACH; /*XXX*/ 211 } 212 } 213 214 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 215 return(error); 216 } 217 218 void 219 #if __STDC__ 220 in_gif_input(struct mbuf *m, ...) 221 #else 222 in_gif_input(m, va_alist) 223 struct mbuf *m; 224 va_dcl 225 #endif 226 { 227 int off, proto; 228 struct ifnet *gifp = NULL; 229 struct ip *ip; 230 va_list ap; 231 int af; 232 u_int8_t otos; 233 234 va_start(ap, m); 235 off = va_arg(ap, int); 236 proto = va_arg(ap, int); 237 va_end(ap); 238 239 ip = mtod(m, struct ip *); 240 241 gifp = (struct ifnet *)encap_getarg(m); 242 243 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 244 m_freem(m); 245 ipstat.ips_nogif++; 246 return; 247 } 248 #ifndef USE_ENCAPCHECK 249 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 250 m_freem(m); 251 ipstat.ips_nogif++; 252 return; 253 } 254 #endif 255 256 otos = ip->ip_tos; 257 m_adj(m, off); 258 259 switch (proto) { 260 #ifdef INET 261 case IPPROTO_IPV4: 262 { 263 struct ip *ip; 264 af = AF_INET; 265 if (m->m_len < sizeof(*ip)) { 266 m = m_pullup(m, sizeof(*ip)); 267 if (!m) 268 return; 269 } 270 ip = mtod(m, struct ip *); 271 if (gifp->if_flags & IFF_LINK1) 272 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 273 else 274 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 275 break; 276 } 277 #endif 278 #ifdef INET6 279 case IPPROTO_IPV6: 280 { 281 struct ip6_hdr *ip6; 282 u_int8_t itos; 283 af = AF_INET6; 284 if (m->m_len < sizeof(*ip6)) { 285 m = m_pullup(m, sizeof(*ip6)); 286 if (!m) 287 return; 288 } 289 ip6 = mtod(m, struct ip6_hdr *); 290 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 291 if (gifp->if_flags & IFF_LINK1) 292 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 293 else 294 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 295 ip6->ip6_flow &= ~htonl(0xff << 20); 296 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 297 break; 298 } 299 #endif /* INET6 */ 300 #ifdef ISO 301 case IPPROTO_EON: 302 af = AF_ISO; 303 break; 304 #endif 305 default: 306 ipstat.ips_nogif++; 307 m_freem(m); 308 return; 309 } 310 gif_input(m, af, gifp); 311 return; 312 } 313 314 /* 315 * validate outer address. 316 */ 317 static int 318 gif_validate4(ip, sc, ifp) 319 const struct ip *ip; 320 struct gif_softc *sc; 321 struct ifnet *ifp; 322 { 323 struct sockaddr_in *src, *dst; 324 struct in_ifaddr *ia4; 325 326 src = (struct sockaddr_in *)sc->gif_psrc; 327 dst = (struct sockaddr_in *)sc->gif_pdst; 328 329 /* check for address match */ 330 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 331 dst->sin_addr.s_addr != ip->ip_src.s_addr) 332 return 0; 333 334 /* martian filters on outer source - NOT done in ip_input! */ 335 if (IN_MULTICAST(ip->ip_src.s_addr)) 336 return 0; 337 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 338 case 0: case 127: case 255: 339 return 0; 340 } 341 /* reject packets with broadcast on source */ 342 TAILQ_FOREACH(ia4, &in_ifaddr, ia_list) { 343 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 344 continue; 345 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 346 return 0; 347 } 348 349 /* ingress filters on outer source */ 350 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 351 struct sockaddr_in sin; 352 struct rtentry *rt; 353 354 bzero(&sin, sizeof(sin)); 355 sin.sin_family = AF_INET; 356 sin.sin_len = sizeof(struct sockaddr_in); 357 sin.sin_addr = ip->ip_src; 358 rt = rtalloc1((struct sockaddr *)&sin, 0); 359 if (!rt || rt->rt_ifp != ifp) { 360 #if 0 361 log(LOG_WARNING, "%s: packet from 0x%x dropped " 362 "due to ingress filter\n", if_name(&sc->gif_if), 363 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 364 #endif 365 if (rt) 366 rtfree(rt); 367 return 0; 368 } 369 rtfree(rt); 370 } 371 372 return 32 * 2; 373 } 374 375 /* 376 * we know that we are in IFF_UP, outer address available, and outer family 377 * matched the physical addr family. see gif_encapcheck(). 378 */ 379 int 380 gif_encapcheck4(m, off, proto, arg) 381 const struct mbuf *m; 382 int off; 383 int proto; 384 void *arg; 385 { 386 struct ip ip; 387 struct gif_softc *sc; 388 struct ifnet *ifp; 389 390 /* sanity check done in caller */ 391 sc = (struct gif_softc *)arg; 392 393 /* LINTED const cast */ 394 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 395 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 396 397 return gif_validate4(&ip, sc, ifp); 398 } 399 400 int 401 in_gif_attach(sc) 402 struct gif_softc *sc; 403 { 404 #ifndef USE_ENCAPCHECK 405 struct sockaddr_in mask4; 406 407 bzero(&mask4, sizeof(mask4)); 408 mask4.sin_len = sizeof(struct sockaddr_in); 409 mask4.sin_addr.s_addr = ~0; 410 411 if (!sc->gif_psrc || !sc->gif_pdst) 412 return EINVAL; 413 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 414 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 415 (struct protosw *)&in_gif_protosw, sc); 416 #else 417 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 418 &in_gif_protosw, sc); 419 #endif 420 if (sc->encap_cookie4 == NULL) 421 return EEXIST; 422 return 0; 423 } 424 425 int 426 in_gif_detach(sc) 427 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
Indexes created Sat Sep 27 14:09:57 GMT 2025