in_gif.c revision 1.26
1 /* $NetBSD: in_gif.c,v 1.26 2001/12/21 03:21:51 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 1.26 2001/12/21 03:21:51 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 = 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 dst->sin_family = sin_dst->sin_family; 191 dst->sin_len = sizeof(struct sockaddr_in); 192 dst->sin_addr = sin_dst->sin_addr; 193 if (sc->gif_ro.ro_rt) { 194 RTFREE(sc->gif_ro.ro_rt); 195 sc->gif_ro.ro_rt = NULL; 196 } 197 } 198 199 if (sc->gif_ro.ro_rt == NULL) { 200 rtalloc(&sc->gif_ro); 201 if (sc->gif_ro.ro_rt == NULL) { 202 m_freem(m); 203 return ENETUNREACH; 204 } 205 206 /* if it constitutes infinite encapsulation, punt. */ 207 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 208 m_freem(m); 209 return ENETUNREACH; /*XXX*/ 210 } 211 } 212 213 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 214 return(error); 215 } 216 217 void 218 #if __STDC__ 219 in_gif_input(struct mbuf *m, ...) 220 #else 221 in_gif_input(m, va_alist) 222 struct mbuf *m; 223 va_dcl 224 #endif 225 { 226 int off, proto; 227 struct ifnet *gifp = NULL; 228 struct ip *ip; 229 va_list ap; 230 int af; 231 u_int8_t otos; 232 233 va_start(ap, m); 234 off = va_arg(ap, int); 235 proto = va_arg(ap, int); 236 va_end(ap); 237 238 ip = mtod(m, struct ip *); 239 240 gifp = (struct ifnet *)encap_getarg(m); 241 242 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 243 m_freem(m); 244 ipstat.ips_nogif++; 245 return; 246 } 247 #ifndef USE_ENCAPCHECK 248 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 249 m_freem(m); 250 ipstat.ips_nogif++; 251 return; 252 } 253 #endif 254 255 otos = ip->ip_tos; 256 m_adj(m, off); 257 258 switch (proto) { 259 #ifdef INET 260 case IPPROTO_IPV4: 261 { 262 struct ip *ip; 263 af = AF_INET; 264 if (m->m_len < sizeof(*ip)) { 265 m = m_pullup(m, sizeof(*ip)); 266 if (!m) 267 return; 268 } 269 ip = mtod(m, struct ip *); 270 if (gifp->if_flags & IFF_LINK1) 271 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 272 else 273 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 274 break; 275 } 276 #endif 277 #ifdef INET6 278 case IPPROTO_IPV6: 279 { 280 struct ip6_hdr *ip6; 281 u_int8_t itos; 282 af = AF_INET6; 283 if (m->m_len < sizeof(*ip6)) { 284 m = m_pullup(m, sizeof(*ip6)); 285 if (!m) 286 return; 287 } 288 ip6 = mtod(m, struct ip6_hdr *); 289 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 290 if (gifp->if_flags & IFF_LINK1) 291 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 292 else 293 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 294 ip6->ip6_flow &= ~htonl(0xff << 20); 295 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 296 break; 297 } 298 #endif /* INET6 */ 299 #ifdef ISO 300 case IPPROTO_EON: 301 af = AF_ISO; 302 break; 303 #endif 304 default: 305 ipstat.ips_nogif++; 306 m_freem(m); 307 return; 308 } 309 gif_input(m, af, gifp); 310 return; 311 } 312 313 /* 314 * validate outer address. 315 */ 316 static int 317 gif_validate4(ip, sc, ifp) 318 const struct ip *ip; 319 struct gif_softc *sc; 320 struct ifnet *ifp; 321 { 322 struct sockaddr_in *src, *dst; 323 struct in_ifaddr *ia4; 324 325 src = (struct sockaddr_in *)sc->gif_psrc; 326 dst = (struct sockaddr_in *)sc->gif_pdst; 327 328 /* check for address match */ 329 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 330 dst->sin_addr.s_addr != ip->ip_src.s_addr) 331 return 0; 332 333 /* martian filters on outer source - NOT done in ip_input! */ 334 if (IN_MULTICAST(ip->ip_src.s_addr)) 335 return 0; 336 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 337 case 0: case 127: case 255: 338 return 0; 339 } 340 /* reject packets with broadcast on source */ 341 TAILQ_FOREACH(ia4, &in_ifaddr, ia_list) { 342 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 343 continue; 344 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 345 return 0; 346 } 347 348 /* ingress filters on outer source */ 349 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 350 struct sockaddr_in sin; 351 struct rtentry *rt; 352 353 bzero(&sin, sizeof(sin)); 354 sin.sin_family = AF_INET; 355 sin.sin_len = sizeof(struct sockaddr_in); 356 sin.sin_addr = ip->ip_src; 357 rt = rtalloc1((struct sockaddr *)&sin, 0); 358 if (!rt || rt->rt_ifp != ifp) { 359 #if 0 360 log(LOG_WARNING, "%s: packet from 0x%x dropped " 361 "due to ingress filter\n", if_name(&sc->gif_if), 362 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 363 #endif 364 if (rt) 365 rtfree(rt); 366 return 0; 367 } 368 rtfree(rt); 369 } 370 371 return 32 * 2; 372 } 373 374 /* 375 * we know that we are in IFF_UP, outer address available, and outer family 376 * matched the physical addr family. see gif_encapcheck(). 377 */ 378 int 379 gif_encapcheck4(m, off, proto, arg) 380 const struct mbuf *m; 381 int off; 382 int proto; 383 void *arg; 384 { 385 struct ip ip; 386 struct gif_softc *sc; 387 struct ifnet *ifp; 388 389 /* sanity check done in caller */ 390 sc = (struct gif_softc *)arg; 391 392 /* LINTED const cast */ 393 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 394 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 395 396 return gif_validate4(&ip, sc, ifp); 397 } 398 399 int 400 in_gif_attach(sc) 401 struct gif_softc *sc; 402 { 403 #ifndef USE_ENCAPCHECK 404 struct sockaddr_in mask4; 405 406 bzero(&mask4, sizeof(mask4)); 407 mask4.sin_len = sizeof(struct sockaddr_in); 408 mask4.sin_addr.s_addr = ~0; 409 410 if (!sc->gif_psrc || !sc->gif_pdst) 411 return EINVAL; 412 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 413 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 414 (struct protosw *)&in_gif_protosw, sc); 415 #else 416 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 417 &in_gif_protosw, sc); 418 #endif 419 if (sc->encap_cookie4 == NULL) 420 return EEXIST; 421 return 0; 422 } 423 424 int 425 in_gif_detach(sc) 426 struct gif_softc *sc; 427 { 428 int error; 429 430 error = encap_detach(sc->encap_cookie4); 431 if (error == 0) 432 sc->encap_cookie4 = NULL; 433 return error; 434 } 435
Indexes created Wed Sep 24 15:09:51 GMT 2025