in_gif.c revision 147503
1/* $FreeBSD: head/sys/netinet/in_gif.c 147503 2005-06-20 08:39:30Z bz $ */ 2/* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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 "opt_mrouting.h" 34#include "opt_inet.h" 35#include "opt_inet6.h" 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/socket.h> 40#include <sys/sockio.h> 41#include <sys/mbuf.h> 42#include <sys/errno.h> 43#include <sys/kernel.h> 44#include <sys/sysctl.h> 45#include <sys/protosw.h> 46 47#include <sys/malloc.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#ifdef MROUTING 66#include <netinet/ip_mroute.h> 67#endif /* MROUTING */ 68 69#include <net/if_gif.h> 70 71#include <net/net_osdep.h> 72 73static int gif_validate4(const struct ip *, struct gif_softc *, 74 struct ifnet *); 75 76extern struct domain inetdomain; 77struct protosw in_gif_protosw = 78{ SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 79 in_gif_input, (pr_output_t*)rip_output, 0, rip_ctloutput, 80 0, 81 0, 0, 0, 0, 82 &rip_usrreqs 83}; 84 85static int ip_gif_ttl = GIF_TTL; 86SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 87 &ip_gif_ttl, 0, ""); 88 89int 90in_gif_output(ifp, family, m) 91 struct ifnet *ifp; 92 int family; 93 struct mbuf *m; 94{ 95 struct gif_softc *sc = ifp->if_softc; 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 int proto, error; 101 u_int8_t tos; 102 103 if (sin_src == NULL || sin_dst == NULL || 104 sin_src->sin_family != AF_INET || 105 sin_dst->sin_family != AF_INET) { 106 m_freem(m); 107 return EAFNOSUPPORT; 108 } 109 110 switch (family) { 111#ifdef INET 112 case AF_INET: 113 { 114 struct ip *ip; 115 116 proto = IPPROTO_IPV4; 117 if (m->m_len < sizeof(*ip)) { 118 m = m_pullup(m, sizeof(*ip)); 119 if (!m) 120 return ENOBUFS; 121 } 122 ip = mtod(m, struct ip *); 123 tos = ip->ip_tos; 124 break; 125 } 126#endif /* INET */ 127#ifdef INET6 128 case AF_INET6: 129 { 130 struct ip6_hdr *ip6; 131 proto = IPPROTO_IPV6; 132 if (m->m_len < sizeof(*ip6)) { 133 m = m_pullup(m, sizeof(*ip6)); 134 if (!m) 135 return ENOBUFS; 136 } 137 ip6 = mtod(m, struct ip6_hdr *); 138 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 139 break; 140 } 141#endif /* INET6 */ 142 default: 143#ifdef DEBUG 144 printf("in_gif_output: warning: unknown family %d passed\n", 145 family); 146#endif 147 m_freem(m); 148 return EAFNOSUPPORT; 149 } 150 151 bzero(&iphdr, sizeof(iphdr)); 152 iphdr.ip_src = sin_src->sin_addr; 153 /* bidirectional configured tunnel mode */ 154 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 155 iphdr.ip_dst = sin_dst->sin_addr; 156 else { 157 m_freem(m); 158 return ENETUNREACH; 159 } 160 iphdr.ip_p = proto; 161 /* version will be set in ip_output() */ 162 iphdr.ip_ttl = ip_gif_ttl; 163 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 164 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 165 &iphdr.ip_tos, &tos); 166 167 /* prepend new IP header */ 168 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 169 if (m && m->m_len < sizeof(struct ip)) 170 m = m_pullup(m, sizeof(struct ip)); 171 if (m == NULL) { 172 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 173 return ENOBUFS; 174 } 175 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 176 177 if (dst->sin_family != sin_dst->sin_family || 178 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 179 /* cache route doesn't match */ 180 bzero(dst, sizeof(*dst)); 181 dst->sin_family = sin_dst->sin_family; 182 dst->sin_len = sizeof(struct sockaddr_in); 183 dst->sin_addr = sin_dst->sin_addr; 184 if (sc->gif_ro.ro_rt) { 185 RTFREE(sc->gif_ro.ro_rt); 186 sc->gif_ro.ro_rt = NULL; 187 } 188#if 0 189 GIF2IFP(sc)->if_mtu = GIF_MTU; 190#endif 191 } 192 193 if (sc->gif_ro.ro_rt == NULL) { 194 rtalloc_ign(&sc->gif_ro, 0); 195 if (sc->gif_ro.ro_rt == NULL) { 196 m_freem(m); 197 return ENETUNREACH; 198 } 199 200 /* if it constitutes infinite encapsulation, punt. */ 201 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 202 m_freem(m); 203 return ENETUNREACH; /* XXX */ 204 } 205#if 0 206 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 207 - sizeof(struct ip); 208#endif 209 } 210 211 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 212 213 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 214 sc->gif_ro.ro_rt != NULL) { 215 RTFREE(sc->gif_ro.ro_rt); 216 sc->gif_ro.ro_rt = NULL; 217 } 218 219 return (error); 220} 221 222void 223in_gif_input(m, off) 224 struct mbuf *m; 225 int off; 226{ 227 struct ifnet *gifp = NULL; 228 struct gif_softc *sc; 229 struct ip *ip; 230 int af; 231 u_int8_t otos; 232 int proto; 233 234 ip = mtod(m, struct ip *); 235 proto = ip->ip_p; 236 237 sc = (struct gif_softc *)encap_getarg(m); 238 if (sc == NULL) { 239 m_freem(m); 240 ipstat.ips_nogif++; 241 return; 242 } 243 244 gifp = GIF2IFP(sc); 245 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 246 m_freem(m); 247 ipstat.ips_nogif++; 248 return; 249 } 250 251 otos = ip->ip_tos; 252 m_adj(m, off); 253 254 switch (proto) { 255#ifdef INET 256 case IPPROTO_IPV4: 257 { 258 struct ip *ip; 259 af = AF_INET; 260 if (m->m_len < sizeof(*ip)) { 261 m = m_pullup(m, sizeof(*ip)); 262 if (!m) 263 return; 264 } 265 ip = mtod(m, struct ip *); 266 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 267 ECN_ALLOWED : ECN_NOCARE, 268 &otos, &ip->ip_tos) == 0) { 269 m_freem(m); 270 return; 271 } 272 break; 273 } 274#endif 275#ifdef INET6 276 case IPPROTO_IPV6: 277 { 278 struct ip6_hdr *ip6; 279 u_int8_t itos, oitos; 280 281 af = AF_INET6; 282 if (m->m_len < sizeof(*ip6)) { 283 m = m_pullup(m, sizeof(*ip6)); 284 if (!m) 285 return; 286 } 287 ip6 = mtod(m, struct ip6_hdr *); 288 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 289 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 290 ECN_ALLOWED : ECN_NOCARE, 291 &otos, &itos) == 0) { 292 m_freem(m); 293 return; 294 } 295 if (itos != oitos) { 296 ip6->ip6_flow &= ~htonl(0xff << 20); 297 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 298 } 299 break; 300 } 301#endif /* INET6 */ 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 */ 314static int 315gif_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(ntohl(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_ifaddrhead, ia_link) { 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 ((GIF2IFP(sc)->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, 0UL); 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(GIF2IFP(sc)), 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/* 373 * we know that we are in IFF_UP, outer address available, and outer family 374 * matched the physical addr family. see gif_encapcheck(). 375 */ 376int 377gif_encapcheck4(m, off, proto, arg) 378 const struct mbuf *m; 379 int off; 380 int proto; 381 void *arg; 382{ 383 struct ip ip; 384 struct gif_softc *sc; 385 struct ifnet *ifp; 386 387 /* sanity check done in caller */ 388 sc = (struct gif_softc *)arg; 389 390 /* LINTED const cast */ 391 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 392 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 393 394 return gif_validate4(&ip, sc, ifp); 395} 396 397int 398in_gif_attach(sc) 399 struct gif_softc *sc; 400{ 401 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 402 &in_gif_protosw, sc); 403 if (sc->encap_cookie4 == NULL) 404 return EEXIST; 405 return 0; 406} 407 408int 409in_gif_detach(sc) 410 struct gif_softc *sc; 411{ 412 int error; 413 414 error = encap_detach(sc->encap_cookie4); 415 if (error == 0) 416 sc->encap_cookie4 = NULL; 417 return error; 418} 419