in_gif.c revision 1.33
1 /* $NetBSD: in_gif.c,v 1.33 2003/08/22 21:53:03 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 1.33 2003/08/22 21:53:03 itojun 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 69 #include <machine/stdarg.h> 70 71 #include <net/net_osdep.h> 72 73 static int gif_validate4 __P((const struct ip *, struct gif_softc *, 74 struct ifnet *)); 75 76 #if NGIF > 0 77 int ip_gif_ttl = GIF_TTL; 78 #else 79 int ip_gif_ttl = 0; 80 #endif 81 82 extern struct domain inetdomain; 83 struct protosw in_gif_protosw = 84 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 85 in_gif_input, rip_output, 0, rip_ctloutput, 86 rip_usrreq, 87 0, 0, 0, 0, 88 }; 89 90 int 91 in_gif_output(ifp, family, m) 92 struct ifnet *ifp; 93 int family; 94 struct mbuf *m; 95 { 96 struct gif_softc *sc = (struct gif_softc*)ifp; 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 int proto, error; 102 u_int8_t tos; 103 104 if (sin_src == NULL || sin_dst == NULL || 105 sin_src->sin_family != AF_INET || 106 sin_dst->sin_family != AF_INET) { 107 m_freem(m); 108 return EAFNOSUPPORT; 109 } 110 111 switch (family) { 112 #ifdef INET 113 case AF_INET: 114 { 115 struct ip *ip; 116 117 proto = IPPROTO_IPV4; 118 if (m->m_len < sizeof(*ip)) { 119 m = m_pullup(m, sizeof(*ip)); 120 if (!m) 121 return ENOBUFS; 122 } 123 ip = mtod(m, struct ip *); 124 tos = ip->ip_tos; 125 break; 126 } 127 #endif /* INET */ 128 #ifdef INET6 129 case AF_INET6: 130 { 131 struct ip6_hdr *ip6; 132 proto = IPPROTO_IPV6; 133 if (m->m_len < sizeof(*ip6)) { 134 m = m_pullup(m, sizeof(*ip6)); 135 if (!m) 136 return ENOBUFS; 137 } 138 ip6 = mtod(m, struct ip6_hdr *); 139 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 140 break; 141 } 142 #endif /* INET6 */ 143 #ifdef ISO 144 case AF_ISO: 145 proto = IPPROTO_EON; 146 tos = 0; 147 break; 148 #endif 149 default: 150 #ifdef DEBUG 151 printf("in_gif_output: warning: unknown family %d passed\n", 152 family); 153 #endif 154 m_freem(m); 155 return EAFNOSUPPORT; 156 } 157 158 bzero(&iphdr, sizeof(iphdr)); 159 iphdr.ip_src = sin_src->sin_addr; 160 /* bidirectional configured tunnel mode */ 161 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 162 iphdr.ip_dst = sin_dst->sin_addr; 163 else { 164 m_freem(m); 165 return ENETUNREACH; 166 } 167 iphdr.ip_p = proto; 168 /* version will be set in ip_output() */ 169 iphdr.ip_ttl = ip_gif_ttl; 170 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 171 if (ifp->if_flags & IFF_LINK1) 172 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 173 else 174 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 175 176 /* prepend new IP header */ 177 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 178 if (m && m->m_len < sizeof(struct ip)) 179 m = m_pullup(m, sizeof(struct ip)); 180 if (m == NULL) 181 return ENOBUFS; 182 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 183 184 if (dst->sin_family != sin_dst->sin_family || 185 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 186 /* cache route doesn't match */ 187 bzero(dst, sizeof(*dst)); 188 dst->sin_family = sin_dst->sin_family; 189 dst->sin_len = sizeof(struct sockaddr_in); 190 dst->sin_addr = sin_dst->sin_addr; 191 if (sc->gif_ro.ro_rt) { 192 RTFREE(sc->gif_ro.ro_rt); 193 sc->gif_ro.ro_rt = NULL; 194 } 195 } 196 197 if (sc->gif_ro.ro_rt == NULL) { 198 rtalloc(&sc->gif_ro); 199 if (sc->gif_ro.ro_rt == NULL) { 200 m_freem(m); 201 return ENETUNREACH; 202 } 203 204 /* if it constitutes infinite encapsulation, punt. */ 205 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 206 m_freem(m); 207 return ENETUNREACH; /*XXX*/ 208 } 209 } 210 211 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 212 return (error); 213 } 214 215 void 216 #if __STDC__ 217 in_gif_input(struct mbuf *m, ...) 218 #else 219 in_gif_input(m, va_alist) 220 struct mbuf *m; 221 va_dcl 222 #endif 223 { 224 int off, proto; 225 struct ifnet *gifp = NULL; 226 struct ip *ip; 227 va_list ap; 228 int af; 229 u_int8_t otos; 230 231 va_start(ap, m); 232 off = va_arg(ap, int); 233 proto = va_arg(ap, int); 234 va_end(ap); 235 236 ip = mtod(m, struct ip *); 237 238 gifp = (struct ifnet *)encap_getarg(m); 239 240 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 241 m_freem(m); 242 ipstat.ips_nogif++; 243 return; 244 } 245 #ifndef GIF_ENCAPCHECK 246 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 247 m_freem(m); 248 ipstat.ips_nogif++; 249 return; 250 } 251 #endif 252 253 otos = ip->ip_tos; 254 m_adj(m, off); 255 256 switch (proto) { 257 #ifdef INET 258 case IPPROTO_IPV4: 259 { 260 struct ip *ip; 261 af = AF_INET; 262 if (m->m_len < sizeof(*ip)) { 263 m = m_pullup(m, sizeof(*ip)); 264 if (!m) 265 return; 266 } 267 ip = mtod(m, struct ip *); 268 if (gifp->if_flags & IFF_LINK1) 269 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 270 else 271 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 272 break; 273 } 274 #endif 275 #ifdef INET6 276 case IPPROTO_IPV6: 277 { 278 struct ip6_hdr *ip6; 279 u_int8_t itos; 280 af = AF_INET6; 281 if (m->m_len < sizeof(*ip6)) { 282 m = m_pullup(m, sizeof(*ip6)); 283 if (!m) 284 return; 285 } 286 ip6 = mtod(m, struct ip6_hdr *); 287 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 288 if (gifp->if_flags & IFF_LINK1) 289 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 290 else 291 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 292 ip6->ip6_flow &= ~htonl(0xff << 20); 293 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 294 break; 295 } 296 #endif /* INET6 */ 297 #ifdef ISO 298 case IPPROTO_EON: 299 af = AF_ISO; 300 break; 301 #endif 302 default: 303 ipstat.ips_nogif++; 304 m_freem(m); 305 return; 306 } 307 gif_input(m, af, gifp); 308 return; 309 } 310 311 /* 312 * validate outer address. 313 */ 314 static int 315 gif_validate4(ip, sc, ifp) 316 const struct ip *ip; 317 struct gif_softc *sc; 318 struct ifnet *ifp; 319 { 320 struct sockaddr_in *src, *dst; 321 struct in_ifaddr *ia4; 322 323 src = (struct sockaddr_in *)sc->gif_psrc; 324 dst = (struct sockaddr_in *)sc->gif_pdst; 325 326 /* check for address match */ 327 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 328 dst->sin_addr.s_addr != ip->ip_src.s_addr) 329 return 0; 330 331 /* martian filters on outer source - NOT done in ip_input! */ 332 if (IN_MULTICAST(ip->ip_src.s_addr)) 333 return 0; 334 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 335 case 0: case 127: case 255: 336 return 0; 337 } 338 /* reject packets with broadcast on source */ 339 TAILQ_FOREACH(ia4, &in_ifaddr, ia_list) { 340 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 341 continue; 342 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 343 return 0; 344 } 345 346 /* ingress filters on outer source */ 347 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 348 struct sockaddr_in sin; 349 struct rtentry *rt; 350 351 bzero(&sin, sizeof(sin)); 352 sin.sin_family = AF_INET; 353 sin.sin_len = sizeof(struct sockaddr_in); 354 sin.sin_addr = ip->ip_src; 355 rt = rtalloc1((struct sockaddr *)&sin, 0); 356 if (!rt || rt->rt_ifp != ifp) { 357 #if 0 358 log(LOG_WARNING, "%s: packet from 0x%x dropped " 359 "due to ingress filter\n", if_name(&sc->gif_if), 360 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 361 #endif 362 if (rt) 363 rtfree(rt); 364 return 0; 365 } 366 rtfree(rt); 367 } 368 369 return 32 * 2; 370 } 371 372 #ifdef GIF_ENCAPCHECK 373 /* 374 * we know that we are in IFF_UP, outer address available, and outer family 375 * matched the physical addr family. see gif_encapcheck(). 376 */ 377 int 378 gif_encapcheck4(m, off, proto, arg) 379 const struct mbuf *m; 380 int off; 381 int proto; 382 void *arg; 383 { 384 struct ip ip; 385 struct gif_softc *sc; 386 struct ifnet *ifp; 387 388 /* sanity check done in caller */ 389 sc = (struct gif_softc *)arg; 390 391 /* LINTED const cast */ 392 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 393 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 394 395 return gif_validate4(&ip, sc, ifp); 396 } 397 #endif 398 399 int 400 in_gif_attach(sc) 401 struct gif_softc *sc; 402 { 403 #ifndef GIF_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
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