1 /* $NetBSD: in_gif.c,v 1.46 2005/12/11 12:24:57 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 1.46 2005/12/11 12:24:57 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 #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 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) 123 return ENOBUFS; 124 } 125 ip = mtod(m, struct ip *); 126 tos = ip->ip_tos; 127 break; 128 } 129 #endif /* INET */ 130 #ifdef INET6 131 case AF_INET6: 132 { 133 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, 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 && m->m_len < sizeof(struct etherip_header)) 159 m = m_pullup(m, sizeof(struct etherip_header)); 160 if (m == NULL) 161 return ENOBUFS; 162 bcopy(&eiphdr, mtod(m, struct etherip_header *), sizeof(struct etherip_header)); 163 break; 164 #endif 165 default: 166 #ifdef DEBUG 167 printf("in_gif_output: warning: unknown family %d passed\n", 168 family); 169 #endif 170 m_freem(m); 171 return EAFNOSUPPORT; 172 } 173 174 bzero(&iphdr, sizeof(iphdr)); 175 iphdr.ip_src = sin_src->sin_addr; 176 /* bidirectional configured tunnel mode */ 177 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 178 iphdr.ip_dst = sin_dst->sin_addr; 179 else { 180 m_freem(m); 181 return ENETUNREACH; 182 } 183 iphdr.ip_p = proto; 184 /* version will be set in ip_output() */ 185 iphdr.ip_ttl = ip_gif_ttl; 186 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 187 if (ifp->if_flags & IFF_LINK1) 188 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 189 else 190 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 191 192 /* prepend new IP header */ 193 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 194 if (m && m->m_len < sizeof(struct ip)) 195 m = m_pullup(m, sizeof(struct ip)); 196 if (m == NULL) 197 return ENOBUFS; 198 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 199 200 if (sc->gif_route_expire - time.tv_sec <= 0 || 201 dst->sin_family != sin_dst->sin_family || 202 !in_hosteq(dst->sin_addr, sin_dst->sin_addr)) { 203 /* cache route doesn't match */ 204 bzero(dst, sizeof(*dst)); 205 dst->sin_family = sin_dst->sin_family; 206 dst->sin_len = sizeof(struct sockaddr_in); 207 dst->sin_addr = sin_dst->sin_addr; 208 if (sc->gif_ro.ro_rt) { 209 RTFREE(sc->gif_ro.ro_rt); 210 sc->gif_ro.ro_rt = NULL; 211 } 212 } 213 214 if (sc->gif_ro.ro_rt == NULL) { 215 rtalloc(&sc->gif_ro); 216 if (sc->gif_ro.ro_rt == NULL) { 217 m_freem(m); 218 return ENETUNREACH; 219 } 220 221 /* if it constitutes infinite encapsulation, punt. */ 222 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 223 m_freem(m); 224 return ENETUNREACH; /*XXX*/ 225 } 226 227 sc->gif_route_expire = time.tv_sec + GIF_ROUTE_TTL; 228 } 229 230 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 231 return (error); 232 } 233 234 void 235 in_gif_input(struct mbuf *m, ...) 236 { 237 int off, proto; 238 struct ifnet *gifp = NULL; 239 struct ip *ip; 240 va_list ap; 241 int af; 242 u_int8_t otos; 243 244 va_start(ap, m); 245 off = va_arg(ap, int); 246 proto = va_arg(ap, int); 247 va_end(ap); 248 249 ip = mtod(m, struct ip *); 250 251 gifp = (struct ifnet *)encap_getarg(m); 252 253 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 254 m_freem(m); 255 ipstat.ips_nogif++; 256 return; 257 } 258 #ifndef GIF_ENCAPCHECK 259 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 260 m_freem(m); 261 ipstat.ips_nogif++; 262 return; 263 } 264 #endif 265 266 otos = ip->ip_tos; 267 m_adj(m, off); 268 269 switch (proto) { 270 #ifdef INET 271 case IPPROTO_IPV4: 272 { 273 struct ip *xip; 274 af = AF_INET; 275 if (m->m_len < sizeof(*xip)) { 276 m = m_pullup(m, sizeof(*xip)); 277 if (!m) 278 return; 279 } 280 xip = mtod(m, struct ip *); 281 if (gifp->if_flags & IFF_LINK1) 282 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 283 else 284 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 285 break; 286 } 287 #endif 288 #ifdef INET6 289 case IPPROTO_IPV6: 290 { 291 struct ip6_hdr *ip6; 292 u_int8_t itos; 293 af = AF_INET6; 294 if (m->m_len < sizeof(*ip6)) { 295 m = m_pullup(m, sizeof(*ip6)); 296 if (!m) 297 return; 298 } 299 ip6 = mtod(m, struct ip6_hdr *); 300 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 301 if (gifp->if_flags & IFF_LINK1) 302 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 303 else 304 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 305 ip6->ip6_flow &= ~htonl(0xff << 20); 306 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 307 break; 308 } 309 #endif /* INET6 */ 310 #ifdef ISO 311 case IPPROTO_EON: 312 af = AF_ISO; 313 break; 314 #endif 315 #if NBRIDGE > 0 316 case IPPROTO_ETHERIP: 317 af = AF_LINK; 318 break; 319 #endif 320 default: 321 ipstat.ips_nogif++; 322 m_freem(m); 323 return; 324 } 325 gif_input(m, af, gifp); 326 return; 327 } 328 329 /* 330 * validate outer address. 331 */ 332 static int 333 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 334 { 335 struct sockaddr_in *src, *dst; 336 struct in_ifaddr *ia4; 337 338 src = (struct sockaddr_in *)sc->gif_psrc; 339 dst = (struct sockaddr_in *)sc->gif_pdst; 340 341 /* check for address match */ 342 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 343 dst->sin_addr.s_addr != ip->ip_src.s_addr) 344 return 0; 345 346 /* martian filters on outer source - NOT done in ip_input! */ 347 if (IN_MULTICAST(ip->ip_src.s_addr)) 348 return 0; 349 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 350 case 0: case 127: case 255: 351 return 0; 352 } 353 /* reject packets with broadcast on source */ 354 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 355 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 356 continue; 357 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 358 return 0; 359 } 360 361 /* ingress filters on outer source */ 362 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 363 struct sockaddr_in sin; 364 struct rtentry *rt; 365 366 bzero(&sin, sizeof(sin)); 367 sin.sin_family = AF_INET; 368 sin.sin_len = sizeof(struct sockaddr_in); 369 sin.sin_addr = ip->ip_src; 370 rt = rtalloc1((struct sockaddr *)&sin, 0); 371 if (!rt || rt->rt_ifp != ifp) { 372 #if 0 373 log(LOG_WARNING, "%s: packet from 0x%x dropped " 374 "due to ingress filter\n", if_name(&sc->gif_if), 375 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 376 #endif 377 if (rt) 378 rtfree(rt); 379 return 0; 380 } 381 rtfree(rt); 382 } 383 384 return 32 * 2; 385 } 386 387 #ifdef GIF_ENCAPCHECK 388 /* 389 * we know that we are in IFF_UP, outer address available, and outer family 390 * matched the physical addr family. see gif_encapcheck(). 391 */ 392 int 393 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 394 { 395 struct ip ip; 396 struct gif_softc *sc; 397 struct ifnet *ifp; 398 399 /* sanity check done in caller */ 400 sc = (struct gif_softc *)arg; 401 402 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 403 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 404 405 return gif_validate4(&ip, sc, ifp); 406 } 407 #endif 408 409 int 410 in_gif_attach(struct gif_softc *sc) 411 { 412 #ifndef GIF_ENCAPCHECK 413 struct sockaddr_in mask4; 414 415 bzero(&mask4, sizeof(mask4)); 416 mask4.sin_len = sizeof(struct sockaddr_in); 417 mask4.sin_addr.s_addr = ~0; 418 419 if (!sc->gif_psrc || !sc->gif_pdst) 420 return EINVAL; 421 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 422 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 423 (const struct protosw *)&in_gif_protosw, sc); 424 #else 425 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 426 &in_gif_protosw, sc); 427 #endif 428 if (sc->encap_cookie4 == NULL) 429 return EEXIST; 430 return 0; 431 } 432 433 int 434 in_gif_detach(struct gif_softc *sc) 435 { 436 int error; 437 438 error = encap_detach(sc->encap_cookie4); 439 if (error == 0) 440 sc->encap_cookie4 = NULL; 441 442 if (sc->gif_ro.ro_rt) { 443 RTFREE(sc->gif_ro.ro_rt); 444 sc->gif_ro.ro_rt = NULL; 445 } 446 447 return error; 448 } 449