1 /* 2 * $FreeBSD: src/sys/netinet/in_gif.c,v 1.5.2.11 2003/01/23 21:06:45 sam Exp $ 3 * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ 4 */ 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 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 <machine/stdarg.h> 50 51 #include <net/if.h> 52 #include <net/route.h> 53 54 #include <netinet/in.h> 55 #include <netinet/in_systm.h> 56 #include <netinet/ip.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/in_gif.h> 59 #include <netinet/in_var.h> 60 #include <netinet/ip_encap.h> 61 #include <netinet/ip_ecn.h> 62 63 #ifdef INET6 64 #include <netinet/ip6.h> 65 #endif 66 67 #include <net/gif/if_gif.h> 68 #include <net/net_osdep.h> 69 70 #ifdef INET 71 static int gif_validate4 (const struct ip *, struct gif_softc *, 72 struct ifnet *); 73 74 extern struct domain inetdomain; 75 const struct protosw in_gif_protosw = 76 { 77 .pr_type = SOCK_RAW, 78 .pr_domain = &inetdomain, 79 .pr_protocol = 0 /*IPPROTO_IPV[46]*/, 80 .pr_flags = PR_ATOMIC|PR_ADDR, 81 82 .pr_input = in_gif_input, 83 .pr_output = rip_output, 84 .pr_ctlinput = NULL, 85 .pr_ctloutput = rip_ctloutput, 86 87 .pr_ctlport = NULL, 88 .pr_usrreqs = &rip_usrreqs 89 }; 90 91 int ip_gif_ttl = GIF_TTL; 92 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 93 &ip_gif_ttl, 0, "TTL of GIF packet"); 94 95 int 96 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 97 { 98 struct gif_softc *sc = (struct gif_softc*)ifp; 99 struct route *ro = &sc->gif_ro[mycpu->gd_cpuid]; 100 struct sockaddr_in *dst = (struct sockaddr_in *)&ro->ro_dst; 101 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 102 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 103 struct ip iphdr; /* capsule IP header, host byte ordered */ 104 int proto, error; 105 u_int8_t tos; 106 107 if (sin_src == NULL || sin_dst == NULL || 108 sin_src->sin_family != AF_INET || 109 sin_dst->sin_family != AF_INET) { 110 m_freem(m); 111 return EAFNOSUPPORT; 112 } 113 114 switch (family) { 115 #ifdef INET 116 case AF_INET: 117 { 118 struct ip *ip; 119 120 proto = IPPROTO_IPV4; 121 if (m->m_len < sizeof *ip) { 122 m = m_pullup(m, sizeof *ip); 123 if (!m) 124 return ENOBUFS; 125 } 126 ip = mtod(m, struct ip *); 127 tos = ip->ip_tos; 128 break; 129 } 130 #endif 131 #ifdef INET6 132 case AF_INET6: 133 { 134 struct ip6_hdr *ip6; 135 proto = IPPROTO_IPV6; 136 if (m->m_len < sizeof *ip6) { 137 m = m_pullup(m, sizeof *ip6); 138 if (!m) 139 return ENOBUFS; 140 } 141 ip6 = mtod(m, struct ip6_hdr *); 142 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 143 break; 144 } 145 #endif 146 default: 147 #ifdef DEBUG 148 kprintf("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_NOWAIT); 175 if (m && m->m_len < sizeof(struct ip)) 176 m = m_pullup(m, sizeof(struct ip)); 177 if (m == NULL) { 178 kprintf("ENOBUFS in in_gif_output %d\n", __LINE__); 179 return ENOBUFS; 180 } 181 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 182 183 if (dst->sin_family != sin_dst->sin_family || 184 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 185 /* cache route doesn't match */ 186 dst->sin_family = sin_dst->sin_family; 187 dst->sin_len = sizeof(struct sockaddr_in); 188 dst->sin_addr = sin_dst->sin_addr; 189 if (ro->ro_rt != NULL) { 190 RTFREE(ro->ro_rt); 191 ro->ro_rt = NULL; 192 } 193 #if 0 194 sc->gif_if.if_mtu = GIF_MTU; 195 #endif 196 } 197 198 if (ro->ro_rt == NULL) { 199 rtalloc(ro); 200 if (ro->ro_rt == NULL) { 201 m_freem(m); 202 return ENETUNREACH; 203 } 204 205 /* if it constitutes infinite encapsulation, punt. */ 206 if (ro->ro_rt->rt_ifp == ifp) { 207 m_freem(m); 208 return ENETUNREACH; /* XXX */ 209 } 210 #if 0 211 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu - sizeof(struct ip); 212 #endif 213 } 214 215 error = ip_output(m, NULL, ro, 0, NULL, NULL); 216 return(error); 217 } 218 219 int 220 in_gif_input(struct mbuf **mp, int *offp, int proto) 221 { 222 struct mbuf *m = *mp; 223 struct ifnet *gifp = NULL; 224 struct ip *ip; 225 int af; 226 u_int8_t otos; 227 int off; 228 229 off = *offp; 230 *mp = NULL; 231 232 ip = mtod(m, struct ip *); 233 234 gifp = (struct ifnet *)encap_getarg(m); 235 236 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 237 m_freem(m); 238 ipstat.ips_nogif++; 239 return(IPPROTO_DONE); 240 } 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 *ip; 250 af = AF_INET; 251 if (m->m_len < sizeof *ip) { 252 m = m_pullup(m, sizeof *ip); 253 if (!m) 254 return(IPPROTO_DONE); 255 } 256 ip = mtod(m, struct ip *); 257 if (gifp->if_flags & IFF_LINK1) 258 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 259 else 260 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 261 break; 262 } 263 #endif 264 #ifdef INET6 265 case IPPROTO_IPV6: 266 { 267 struct ip6_hdr *ip6; 268 u_int8_t itos; 269 af = AF_INET6; 270 if (m->m_len < sizeof *ip6) { 271 m = m_pullup(m, sizeof *ip6); 272 if (!m) 273 return(IPPROTO_DONE); 274 } 275 ip6 = mtod(m, struct ip6_hdr *); 276 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 277 if (gifp->if_flags & IFF_LINK1) 278 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 279 else 280 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 281 ip6->ip6_flow &= ~htonl(0xff << 20); 282 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 283 break; 284 } 285 #endif /* INET6 */ 286 default: 287 ipstat.ips_nogif++; 288 m_freem(m); 289 return(IPPROTO_DONE); 290 } 291 gif_input(m, af, gifp); 292 return(IPPROTO_DONE); 293 } 294 295 /* 296 * validate outer address. 297 */ 298 static int 299 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 300 { 301 struct sockaddr_in *src, *dst; 302 struct in_ifaddr_container *iac; 303 304 src = (struct sockaddr_in *)sc->gif_psrc; 305 dst = (struct sockaddr_in *)sc->gif_pdst; 306 307 /* check for address match */ 308 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 309 dst->sin_addr.s_addr != ip->ip_src.s_addr) 310 return 0; 311 312 /* martian filters on outer source - NOT done in ip_input! */ 313 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 314 return 0; 315 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 316 case 0: case 127: case 255: 317 return 0; 318 } 319 /* reject packets with broadcast on source */ 320 TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) { 321 struct in_ifaddr *ia4 = iac->ia; 322 323 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST)) 324 continue; 325 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 326 return 0; 327 } 328 329 /* ingress filters on outer source */ 330 if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) { 331 struct sockaddr_in sin; 332 struct rtentry *rt; 333 334 bzero(&sin, sizeof sin); 335 sin.sin_family = AF_INET; 336 sin.sin_len = sizeof(struct sockaddr_in); 337 sin.sin_addr = ip->ip_src; 338 rt = rtpurelookup((struct sockaddr *)&sin); 339 if (rt != NULL) 340 --rt->rt_refcnt; 341 if (rt == NULL || rt->rt_ifp != ifp) { 342 #if 0 343 log(LOG_WARNING, "%s: packet from 0x%x dropped " 344 "due to ingress filter\n", if_name(&sc->gif_if), 345 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 346 #endif 347 return 0; 348 } 349 } 350 351 return 32 * 2; 352 } 353 354 /* 355 * we know that we are in IFF_UP, outer address available, and outer family 356 * matched the physical addr family. see gif_encapcheck(). 357 */ 358 int 359 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 360 { 361 struct ip ip; 362 struct gif_softc *sc; 363 struct ifnet *ifp; 364 365 /* sanity check done in caller */ 366 sc = (struct gif_softc *)arg; 367 368 /* LINTED const cast */ 369 m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, &ip); 370 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 371 372 return gif_validate4(&ip, sc, ifp); 373 } 374 375 int 376 in_gif_attach(struct gif_softc *sc) 377 { 378 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 379 &in_gif_protosw, sc); 380 if (sc->encap_cookie4 == NULL) 381 return EEXIST; 382 return 0; 383 } 384 385 int 386 in_gif_detach(struct gif_softc *sc) 387 { 388 int error; 389 390 error = encap_detach(sc->encap_cookie4); 391 if (error == 0) 392 sc->encap_cookie4 = NULL; 393 return error; 394 } 395 396 #endif /* INET */ 397