1 /* $NetBSD: in_gif.c,v 1.50 2006/07/28 17:34:13 dyoung 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 1.50 2006/07/28 17:34:13 dyoung 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 #include "bridge.h" 70 #include <net/if_ether.h> 71 72 #include <machine/stdarg.h> 73 74 #include <net/net_osdep.h> 75 76 static int gif_validate4(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 const struct protosw in_gif_protosw = 86 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 87 in_gif_input, rip_output, 0, rip_ctloutput, 88 rip_usrreq, 89 0, 0, 0, 0, 90 }; 91 92 int 93 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 94 { 95 struct gif_softc *sc = (struct gif_softc*)ifp; 96 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 97 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 98 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 99 struct ip iphdr; /* capsule IP header, host byte ordered */ 100 #if NBRIDGE > 0 101 struct etherip_header eiphdr; 102 #endif 103 int proto, error; 104 u_int8_t tos; 105 106 if (sin_src == NULL || sin_dst == NULL || 107 sin_src->sin_family != AF_INET || 108 sin_dst->sin_family != AF_INET) { 109 m_freem(m); 110 return EAFNOSUPPORT; 111 } 112 113 switch (family) { 114 #ifdef INET 115 case AF_INET: 116 { 117 const struct ip *ip; 118 119 proto = IPPROTO_IPV4; 120 if (m->m_len < sizeof(*ip)) { 121 m = m_pullup(m, sizeof(*ip)); 122 if (m == NULL) 123 return ENOBUFS; 124 } 125 ip = mtod(m, const struct ip *); 126 tos = ip->ip_tos; 127 break; 128 } 129 #endif /* INET */ 130 #ifdef INET6 131 case AF_INET6: 132 { 133 const struct ip6_hdr *ip6; 134 proto = IPPROTO_IPV6; 135 if (m->m_len < sizeof(*ip6)) { 136 m = m_pullup(m, sizeof(*ip6)); 137 if (!m) 138 return ENOBUFS; 139 } 140 ip6 = mtod(m, const struct ip6_hdr *); 141 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 142 break; 143 } 144 #endif /* INET6 */ 145 #ifdef ISO 146 case AF_ISO: 147 proto = IPPROTO_EON; 148 tos = 0; 149 break; 150 #endif 151 #if NBRIDGE > 0 152 case AF_LINK: 153 proto = IPPROTO_ETHERIP; 154 eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; 155 eiphdr.eip_pad = 0; 156 /* prepend Ethernet-in-IP header */ 157 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 158 if (m == NULL) 159 return ENOBUFS; 160 if (M_UNWRITABLE(m, sizeof(struct etherip_header))) { 161 m = m_pullup(m, sizeof(struct etherip_header)); 162 if (m == NULL) 163 return ENOBUFS; 164 } 165 bcopy(&eiphdr, mtod(m, struct etherip_header *), 166 sizeof(struct etherip_header)); 167 break; 168 #endif 169 default: 170 #ifdef DEBUG 171 printf("in_gif_output: warning: unknown family %d passed\n", 172 family); 173 #endif 174 m_freem(m); 175 return EAFNOSUPPORT; 176 } 177 178 bzero(&iphdr, sizeof(iphdr)); 179 iphdr.ip_src = sin_src->sin_addr; 180 /* bidirectional configured tunnel mode */ 181 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 182 iphdr.ip_dst = sin_dst->sin_addr; 183 else { 184 m_freem(m); 185 return ENETUNREACH; 186 } 187 iphdr.ip_p = proto; 188 /* version will be set in ip_output() */ 189 iphdr.ip_ttl = ip_gif_ttl; 190 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 191 if (ifp->if_flags & IFF_LINK1) 192 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 193 else 194 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 195 196 /* prepend new IP header */ 197 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 198 /* XXX Is m_pullup really necessary after M_PREPEND? */ 199 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 200 m = m_pullup(m, sizeof(struct ip)); 201 if (m == NULL) 202 return ENOBUFS; 203 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 204 205 if (sc->gif_route_expire - time_second <= 0 || 206 dst->sin_family != sin_dst->sin_family || 207 !in_hosteq(dst->sin_addr, sin_dst->sin_addr)) { 208 /* cache route doesn't match */ 209 bzero(dst, sizeof(*dst)); 210 dst->sin_family = sin_dst->sin_family; 211 dst->sin_len = sizeof(struct sockaddr_in); 212 dst->sin_addr = sin_dst->sin_addr; 213 if (sc->gif_ro.ro_rt) { 214 RTFREE(sc->gif_ro.ro_rt); 215 sc->gif_ro.ro_rt = NULL; 216 } 217 } 218 219 if (sc->gif_ro.ro_rt == NULL) { 220 rtalloc(&sc->gif_ro); 221 if (sc->gif_ro.ro_rt == NULL) { 222 m_freem(m); 223 return ENETUNREACH; 224 } 225 226 /* if it constitutes infinite encapsulation, punt. */ 227 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 228 m_freem(m); 229 return ENETUNREACH; /*XXX*/ 230 } 231 232 sc->gif_route_expire = time_second + GIF_ROUTE_TTL; 233 } 234 235 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 236 return (error); 237 } 238 239 void 240 in_gif_input(struct mbuf *m, ...) 241 { 242 int off, proto; 243 struct ifnet *gifp = NULL; 244 const struct ip *ip; 245 va_list ap; 246 int af; 247 u_int8_t otos; 248 249 va_start(ap, m); 250 off = va_arg(ap, int); 251 proto = va_arg(ap, int); 252 va_end(ap); 253 254 ip = mtod(m, const struct ip *); 255 256 gifp = (struct ifnet *)encap_getarg(m); 257 258 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 259 m_freem(m); 260 ipstat.ips_nogif++; 261 return; 262 } 263 #ifndef GIF_ENCAPCHECK 264 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 265 m_freem(m); 266 ipstat.ips_nogif++; 267 return; 268 } 269 #endif 270 271 otos = ip->ip_tos; 272 m_adj(m, off); 273 274 switch (proto) { 275 #ifdef INET 276 case IPPROTO_IPV4: 277 { 278 struct ip *xip; 279 af = AF_INET; 280 if (M_UNWRITABLE(m, sizeof(*xip))) { 281 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 282 return; 283 } 284 xip = mtod(m, struct ip *); 285 if (gifp->if_flags & IFF_LINK1) 286 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 287 else 288 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 289 break; 290 } 291 #endif 292 #ifdef INET6 293 case IPPROTO_IPV6: 294 { 295 struct ip6_hdr *ip6; 296 u_int8_t itos; 297 af = AF_INET6; 298 if (M_UNWRITABLE(m, sizeof(*ip6))) { 299 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 300 return; 301 } 302 ip6 = mtod(m, struct ip6_hdr *); 303 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 304 if (gifp->if_flags & IFF_LINK1) 305 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 306 else 307 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 308 ip6->ip6_flow &= ~htonl(0xff << 20); 309 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 310 break; 311 } 312 #endif /* INET6 */ 313 #ifdef ISO 314 case IPPROTO_EON: 315 af = AF_ISO; 316 break; 317 #endif 318 #if NBRIDGE > 0 319 case IPPROTO_ETHERIP: 320 af = AF_LINK; 321 break; 322 #endif 323 default: 324 ipstat.ips_nogif++; 325 m_freem(m); 326 return; 327 } 328 gif_input(m, af, gifp); 329 return; 330 } 331 332 /* 333 * validate outer address. 334 */ 335 static int 336 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 337 { 338 struct sockaddr_in *src, *dst; 339 struct in_ifaddr *ia4; 340 341 src = (struct sockaddr_in *)sc->gif_psrc; 342 dst = (struct sockaddr_in *)sc->gif_pdst; 343 344 /* check for address match */ 345 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 346 dst->sin_addr.s_addr != ip->ip_src.s_addr) 347 return 0; 348 349 /* martian filters on outer source - NOT done in ip_input! */ 350 if (IN_MULTICAST(ip->ip_src.s_addr)) 351 return 0; 352 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 353 case 0: case 127: case 255: 354 return 0; 355 } 356 /* reject packets with broadcast on source */ 357 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 358 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 359 continue; 360 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 361 return 0; 362 } 363 364 /* ingress filters on outer source */ 365 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 366 struct sockaddr_in sin; 367 struct rtentry *rt; 368 369 bzero(&sin, sizeof(sin)); 370 sin.sin_family = AF_INET; 371 sin.sin_len = sizeof(struct sockaddr_in); 372 sin.sin_addr = ip->ip_src; 373 rt = rtalloc1((struct sockaddr *)&sin, 0); 374 if (!rt || rt->rt_ifp != ifp) { 375 #if 0 376 log(LOG_WARNING, "%s: packet from 0x%x dropped " 377 "due to ingress filter\n", if_name(&sc->gif_if), 378 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 379 #endif 380 if (rt) 381 rtfree(rt); 382 return 0; 383 } 384 rtfree(rt); 385 } 386 387 return 32 * 2; 388 } 389 390 #ifdef GIF_ENCAPCHECK 391 /* 392 * we know that we are in IFF_UP, outer address available, and outer family 393 * matched the physical addr family. see gif_encapcheck(). 394 */ 395 int 396 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 397 { 398 struct ip ip; 399 struct gif_softc *sc; 400 struct ifnet *ifp; 401 402 /* sanity check done in caller */ 403 sc = (struct gif_softc *)arg; 404 405 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 406 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 407 408 return gif_validate4(&ip, sc, ifp); 409 } 410 #endif 411 412 int 413 in_gif_attach(struct gif_softc *sc) 414 { 415 #ifndef GIF_ENCAPCHECK 416 struct sockaddr_in mask4; 417 418 bzero(&mask4, sizeof(mask4)); 419 mask4.sin_len = sizeof(struct sockaddr_in); 420 mask4.sin_addr.s_addr = ~0; 421 422 if (!sc->gif_psrc || !sc->gif_pdst) 423 return EINVAL; 424 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 425 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 426 (const struct protosw *)&in_gif_protosw, sc); 427 #else 428 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 429 &in_gif_protosw, sc); 430 #endif 431 if (sc->encap_cookie4 == NULL) 432 return EEXIST; 433 return 0; 434 } 435 436 int 437 in_gif_detach(struct gif_softc *sc) 438 { 439 int error; 440 441 error = encap_detach(sc->encap_cookie4); 442 if (error == 0) 443 sc->encap_cookie4 = NULL; 444 445 if (sc->gif_ro.ro_rt) { 446 RTFREE(sc->gif_ro.ro_rt); 447 sc->gif_ro.ro_rt = NULL; 448 } 449 450 return error; 451 } 452