in_gif.c revision 1.55
1 /* $NetBSD: in_gif.c,v 1.55 2007/03/04 06:03:20 christos 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 1.55 2007/03/04 06:03:20 christos 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 #include <sys/kernel.h> 49 50 #include <net/if.h> 51 #include <net/route.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_var.h> 57 #include <netinet/in_gif.h> 58 #include <netinet/in_var.h> 59 #include <netinet/ip_encap.h> 60 #include <netinet/ip_ecn.h> 61 62 #ifdef INET6 63 #include <netinet/ip6.h> 64 #endif 65 66 #include <net/if_gif.h> 67 68 #include "gif.h" 69 70 #include <machine/stdarg.h> 71 72 #include <net/net_osdep.h> 73 74 static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77 #if NGIF > 0 78 int ip_gif_ttl = GIF_TTL; 79 #else 80 int ip_gif_ttl = 0; 81 #endif 82 83 const 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(struct ifnet *ifp, int family, struct mbuf *m) 92 { 93 struct gif_softc *sc = (struct gif_softc*)ifp; 94 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 95 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 96 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 97 struct ip iphdr; /* capsule IP header, host byte ordered */ 98 int proto, error; 99 u_int8_t tos; 100 101 if (sin_src == NULL || sin_dst == NULL || 102 sin_src->sin_family != AF_INET || 103 sin_dst->sin_family != AF_INET) { 104 m_freem(m); 105 return EAFNOSUPPORT; 106 } 107 108 switch (family) { 109 #ifdef INET 110 case AF_INET: 111 { 112 const struct ip *ip; 113 114 proto = IPPROTO_IPV4; 115 if (m->m_len < sizeof(*ip)) { 116 m = m_pullup(m, sizeof(*ip)); 117 if (m == NULL) 118 return ENOBUFS; 119 } 120 ip = mtod(m, const struct ip *); 121 tos = ip->ip_tos; 122 break; 123 } 124 #endif /* INET */ 125 #ifdef INET6 126 case AF_INET6: 127 { 128 const struct ip6_hdr *ip6; 129 proto = IPPROTO_IPV6; 130 if (m->m_len < sizeof(*ip6)) { 131 m = m_pullup(m, sizeof(*ip6)); 132 if (!m) 133 return ENOBUFS; 134 } 135 ip6 = mtod(m, const struct ip6_hdr *); 136 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 137 break; 138 } 139 #endif /* INET6 */ 140 #ifdef ISO 141 case AF_ISO: 142 proto = IPPROTO_EON; 143 tos = 0; 144 break; 145 #endif 146 default: 147 #ifdef DEBUG 148 printf("in_gif_output: warning: unknown family %d passed\n", 149 family); 150 #endif 151 m_freem(m); 152 return EAFNOSUPPORT; 153 } 154 155 bzero(&iphdr, sizeof(iphdr)); 156 iphdr.ip_src = sin_src->sin_addr; 157 /* bidirectional configured tunnel mode */ 158 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 159 iphdr.ip_dst = sin_dst->sin_addr; 160 else { 161 m_freem(m); 162 return ENETUNREACH; 163 } 164 iphdr.ip_p = proto; 165 /* version will be set in ip_output() */ 166 iphdr.ip_ttl = ip_gif_ttl; 167 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 168 if (ifp->if_flags & IFF_LINK1) 169 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 170 else 171 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 172 173 /* prepend new IP header */ 174 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 175 /* XXX Is m_pullup really necessary after M_PREPEND? */ 176 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 177 m = m_pullup(m, sizeof(struct ip)); 178 if (m == NULL) 179 return ENOBUFS; 180 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 181 182 if (dst->sin_family != sin_dst->sin_family || 183 !in_hosteq(dst->sin_addr, sin_dst->sin_addr)) 184 rtcache_free(&sc->gif_ro); 185 else 186 rtcache_check(&sc->gif_ro); 187 if (sc->gif_ro.ro_rt == NULL) { 188 memset(dst, 0, sizeof(*dst)); 189 dst->sin_family = sin_dst->sin_family; 190 dst->sin_len = sizeof(struct sockaddr_in); 191 dst->sin_addr = sin_dst->sin_addr; 192 rtcache_init(&sc->gif_ro); 193 if (sc->gif_ro.ro_rt == NULL) { 194 m_freem(m); 195 return ENETUNREACH; 196 } 197 } 198 199 /* If the route constitutes infinite encapsulation, punt. */ 200 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 201 rtcache_free(&sc->gif_ro); 202 m_freem(m); 203 return ENETUNREACH; /*XXX*/ 204 } 205 206 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 207 return (error); 208 } 209 210 void 211 in_gif_input(struct mbuf *m, ...) 212 { 213 int off, proto; 214 struct ifnet *gifp = NULL; 215 const struct ip *ip; 216 va_list ap; 217 int af; 218 u_int8_t otos; 219 220 va_start(ap, m); 221 off = va_arg(ap, int); 222 proto = va_arg(ap, int); 223 va_end(ap); 224 225 ip = mtod(m, const struct ip *); 226 227 gifp = (struct ifnet *)encap_getarg(m); 228 229 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 230 m_freem(m); 231 ipstat.ips_nogif++; 232 return; 233 } 234 #ifndef GIF_ENCAPCHECK 235 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 236 m_freem(m); 237 ipstat.ips_nogif++; 238 return; 239 } 240 #endif 241 242 otos = ip->ip_tos; 243 m_adj(m, off); 244 245 switch (proto) { 246 #ifdef INET 247 case IPPROTO_IPV4: 248 { 249 struct ip *xip; 250 af = AF_INET; 251 if (M_UNWRITABLE(m, sizeof(*xip))) { 252 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 253 return; 254 } 255 xip = mtod(m, struct ip *); 256 if (gifp->if_flags & IFF_LINK1) 257 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 258 else 259 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 260 break; 261 } 262 #endif 263 #ifdef INET6 264 case IPPROTO_IPV6: 265 { 266 struct ip6_hdr *ip6; 267 u_int8_t itos; 268 af = AF_INET6; 269 if (M_UNWRITABLE(m, sizeof(*ip6))) { 270 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 271 return; 272 } 273 ip6 = mtod(m, struct ip6_hdr *); 274 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 275 if (gifp->if_flags & IFF_LINK1) 276 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 277 else 278 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 279 ip6->ip6_flow &= ~htonl(0xff << 20); 280 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 281 break; 282 } 283 #endif /* INET6 */ 284 #ifdef ISO 285 case IPPROTO_EON: 286 af = AF_ISO; 287 break; 288 #endif 289 default: 290 ipstat.ips_nogif++; 291 m_freem(m); 292 return; 293 } 294 gif_input(m, af, gifp); 295 return; 296 } 297 298 /* 299 * validate outer address. 300 */ 301 static int 302 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 303 { 304 struct sockaddr_in *src, *dst; 305 struct in_ifaddr *ia4; 306 307 src = (struct sockaddr_in *)sc->gif_psrc; 308 dst = (struct sockaddr_in *)sc->gif_pdst; 309 310 /* check for address match */ 311 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 312 dst->sin_addr.s_addr != ip->ip_src.s_addr) 313 return 0; 314 315 /* martian filters on outer source - NOT done in ip_input! */ 316 if (IN_MULTICAST(ip->ip_src.s_addr)) 317 return 0; 318 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 319 case 0: case 127: case 255: 320 return 0; 321 } 322 /* reject packets with broadcast on source */ 323 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 324 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 325 continue; 326 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 327 return 0; 328 } 329 330 /* ingress filters on outer source */ 331 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 332 struct sockaddr_in sin; 333 struct rtentry *rt; 334 335 bzero(&sin, sizeof(sin)); 336 sin.sin_family = AF_INET; 337 sin.sin_len = sizeof(struct sockaddr_in); 338 sin.sin_addr = ip->ip_src; 339 rt = rtalloc1((struct sockaddr *)&sin, 0); 340 if (!rt || rt->rt_ifp != ifp) { 341 #if 0 342 log(LOG_WARNING, "%s: packet from 0x%x dropped " 343 "due to ingress filter\n", if_name(&sc->gif_if), 344 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 345 #endif 346 if (rt) 347 rtfree(rt); 348 return 0; 349 } 350 rtfree(rt); 351 } 352 353 return 32 * 2; 354 } 355 356 #ifdef GIF_ENCAPCHECK 357 /* 358 * we know that we are in IFF_UP, outer address available, and outer family 359 * matched the physical addr family. see gif_encapcheck(). 360 */ 361 int 362 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 363 { 364 struct ip ip; 365 struct gif_softc *sc; 366 struct ifnet *ifp; 367 368 /* sanity check done in caller */ 369 sc = (struct gif_softc *)arg; 370 371 m_copydata(m, 0, sizeof(ip), (void *)&ip); 372 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 373 374 return gif_validate4(&ip, sc, ifp); 375 } 376 #endif 377 378 int 379 in_gif_attach(struct gif_softc *sc) 380 { 381 #ifndef GIF_ENCAPCHECK 382 struct sockaddr_in mask4; 383 384 bzero(&mask4, sizeof(mask4)); 385 mask4.sin_len = sizeof(struct sockaddr_in); 386 mask4.sin_addr.s_addr = ~0; 387 388 if (!sc->gif_psrc || !sc->gif_pdst) 389 return EINVAL; 390 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 391 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 392 (const struct protosw *)&in_gif_protosw, sc); 393 #else 394 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 395 &in_gif_protosw, sc); 396 #endif 397 if (sc->encap_cookie4 == NULL) 398 return EEXIST; 399 return 0; 400 } 401 402 int 403 in_gif_detach(struct gif_softc *sc) 404 { 405 int error; 406 407 error = encap_detach(sc->encap_cookie4); 408 if (error == 0) 409 sc->encap_cookie4 = NULL; 410 411 rtcache_free(&sc->gif_ro); 412 413 return error; 414 } 415
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