in_gif.c revision 152242
1/* $FreeBSD: head/sys/netinet/in_gif.c 152242 2005-11-09 13:29:16Z ru $ */ 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 .pr_type = SOCK_RAW, 79 .pr_domain = &inetdomain, 80 .pr_protocol = 0/* IPPROTO_IPV[46] */, 81 .pr_flags = PR_ATOMIC|PR_ADDR, 82 .pr_input = in_gif_input, 83 .pr_output = (pr_output_t*)rip_output, 84 .pr_ctloutput = rip_ctloutput, 85 .pr_usrreqs = &rip_usrreqs 86}; 87 88static int ip_gif_ttl = GIF_TTL; 89SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 90 &ip_gif_ttl, 0, ""); 91 92int 93in_gif_output(ifp, family, m) 94 struct ifnet *ifp; 95 int family; 96 struct mbuf *m; 97{ 98 struct gif_softc *sc = ifp->if_softc; 99 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 100 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 101 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 102 struct ip iphdr; /* capsule IP header, host byte ordered */ 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 default: 146#ifdef DEBUG 147 printf("in_gif_output: warning: unknown family %d passed\n", 148 family); 149#endif 150 m_freem(m); 151 return EAFNOSUPPORT; 152 } 153 154 bzero(&iphdr, sizeof(iphdr)); 155 iphdr.ip_src = sin_src->sin_addr; 156 /* bidirectional configured tunnel mode */ 157 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 158 iphdr.ip_dst = sin_dst->sin_addr; 159 else { 160 m_freem(m); 161 return ENETUNREACH; 162 } 163 iphdr.ip_p = proto; 164 /* version will be set in ip_output() */ 165 iphdr.ip_ttl = ip_gif_ttl; 166 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 167 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 168 &iphdr.ip_tos, &tos); 169 170 /* prepend new IP header */ 171 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 172 if (m && m->m_len < sizeof(struct ip)) 173 m = m_pullup(m, sizeof(struct ip)); 174 if (m == NULL) { 175 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 176 return ENOBUFS; 177 } 178 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 179 180 if (dst->sin_family != sin_dst->sin_family || 181 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 182 /* cache route doesn't match */ 183 bzero(dst, sizeof(*dst)); 184 dst->sin_family = sin_dst->sin_family; 185 dst->sin_len = sizeof(struct sockaddr_in); 186 dst->sin_addr = sin_dst->sin_addr; 187 if (sc->gif_ro.ro_rt) { 188 RTFREE(sc->gif_ro.ro_rt); 189 sc->gif_ro.ro_rt = NULL; 190 } 191#if 0 192 GIF2IFP(sc)->if_mtu = GIF_MTU; 193#endif 194 } 195 196 if (sc->gif_ro.ro_rt == NULL) { 197 rtalloc_ign(&sc->gif_ro, 0); 198 if (sc->gif_ro.ro_rt == NULL) { 199 m_freem(m); 200 return ENETUNREACH; 201 } 202 203 /* if it constitutes infinite encapsulation, punt. */ 204 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 205 m_freem(m); 206 return ENETUNREACH; /* XXX */ 207 } 208#if 0 209 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 210 - sizeof(struct ip); 211#endif 212 } 213 214 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 215 216 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 217 sc->gif_ro.ro_rt != NULL) { 218 RTFREE(sc->gif_ro.ro_rt); 219 sc->gif_ro.ro_rt = NULL; 220 } 221 222 return (error); 223} 224 225void 226in_gif_input(m, off) 227 struct mbuf *m; 228 int off; 229{ 230 struct ifnet *gifp = NULL; 231 struct gif_softc *sc; 232 struct ip *ip; 233 int af; 234 u_int8_t otos; 235 int proto; 236 237 ip = mtod(m, struct ip *); 238 proto = ip->ip_p; 239 240 sc = (struct gif_softc *)encap_getarg(m); 241 if (sc == NULL) { 242 m_freem(m); 243 ipstat.ips_nogif++; 244 return; 245 } 246 247 gifp = GIF2IFP(sc); 248 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 249 m_freem(m); 250 ipstat.ips_nogif++; 251 return; 252 } 253 254 otos = ip->ip_tos; 255 m_adj(m, off); 256 257 switch (proto) { 258#ifdef INET 259 case IPPROTO_IPV4: 260 { 261 struct ip *ip; 262 af = AF_INET; 263 if (m->m_len < sizeof(*ip)) { 264 m = m_pullup(m, sizeof(*ip)); 265 if (!m) 266 return; 267 } 268 ip = mtod(m, struct ip *); 269 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 270 ECN_ALLOWED : ECN_NOCARE, 271 &otos, &ip->ip_tos) == 0) { 272 m_freem(m); 273 return; 274 } 275 break; 276 } 277#endif 278#ifdef INET6 279 case IPPROTO_IPV6: 280 { 281 struct ip6_hdr *ip6; 282 u_int8_t itos, oitos; 283 284 af = AF_INET6; 285 if (m->m_len < sizeof(*ip6)) { 286 m = m_pullup(m, sizeof(*ip6)); 287 if (!m) 288 return; 289 } 290 ip6 = mtod(m, struct ip6_hdr *); 291 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 292 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 293 ECN_ALLOWED : ECN_NOCARE, 294 &otos, &itos) == 0) { 295 m_freem(m); 296 return; 297 } 298 if (itos != oitos) { 299 ip6->ip6_flow &= ~htonl(0xff << 20); 300 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 301 } 302 break; 303 } 304#endif /* INET6 */ 305 default: 306 ipstat.ips_nogif++; 307 m_freem(m); 308 return; 309 } 310 gif_input(m, af, gifp); 311 return; 312} 313 314/* 315 * validate outer address. 316 */ 317static int 318gif_validate4(ip, sc, ifp) 319 const struct ip *ip; 320 struct gif_softc *sc; 321 struct ifnet *ifp; 322{ 323 struct sockaddr_in *src, *dst; 324 struct in_ifaddr *ia4; 325 326 src = (struct sockaddr_in *)sc->gif_psrc; 327 dst = (struct sockaddr_in *)sc->gif_pdst; 328 329 /* check for address match */ 330 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 331 dst->sin_addr.s_addr != ip->ip_src.s_addr) 332 return 0; 333 334 /* martian filters on outer source - NOT done in ip_input! */ 335 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 336 return 0; 337 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 338 case 0: case 127: case 255: 339 return 0; 340 } 341 /* reject packets with broadcast on source */ 342 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) { 343 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 344 continue; 345 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 346 return 0; 347 } 348 349 /* ingress filters on outer source */ 350 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 351 struct sockaddr_in sin; 352 struct rtentry *rt; 353 354 bzero(&sin, sizeof(sin)); 355 sin.sin_family = AF_INET; 356 sin.sin_len = sizeof(struct sockaddr_in); 357 sin.sin_addr = ip->ip_src; 358 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 359 if (!rt || rt->rt_ifp != ifp) { 360#if 0 361 log(LOG_WARNING, "%s: packet from 0x%x dropped " 362 "due to ingress filter\n", if_name(GIF2IFP(sc)), 363 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 364#endif 365 if (rt) 366 rtfree(rt); 367 return 0; 368 } 369 rtfree(rt); 370 } 371 372 return 32 * 2; 373} 374 375/* 376 * we know that we are in IFF_UP, outer address available, and outer family 377 * matched the physical addr family. see gif_encapcheck(). 378 */ 379int 380gif_encapcheck4(m, off, proto, arg) 381 const struct mbuf *m; 382 int off; 383 int proto; 384 void *arg; 385{ 386 struct ip ip; 387 struct gif_softc *sc; 388 struct ifnet *ifp; 389 390 /* sanity check done in caller */ 391 sc = (struct gif_softc *)arg; 392 393 /* LINTED const cast */ 394 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 395 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 396 397 return gif_validate4(&ip, sc, ifp); 398} 399 400int 401in_gif_attach(sc) 402 struct gif_softc *sc; 403{ 404 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 405 &in_gif_protosw, sc); 406 if (sc->encap_cookie4 == NULL) 407 return EEXIST; 408 return 0; 409} 410 411int 412in_gif_detach(sc) 413 struct gif_softc *sc; 414{ 415 int error; 416 417 error = encap_detach(sc->encap_cookie4); 418 if (error == 0) 419 sc->encap_cookie4 = NULL; 420 return error; 421} 422