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 #include <sys/thread2.h> /* ipstat */ 71 72 #ifdef INET 73 static int gif_validate4 (const struct ip *, struct gif_softc *, 74 struct ifnet *); 75 76 extern struct domain inetdomain; 77 const struct protosw in_gif_protosw = 78 { 79 .pr_type = SOCK_RAW, 80 .pr_domain = &inetdomain, 81 .pr_protocol = 0 /*IPPROTO_IPV[46]*/, 82 .pr_flags = PR_ATOMIC|PR_ADDR, 83 84 .pr_input = in_gif_input, 85 .pr_output = rip_output, 86 .pr_ctlinput = NULL, 87 .pr_ctloutput = rip_ctloutput, 88 89 .pr_ctlport = NULL, 90 .pr_usrreqs = &rip_usrreqs 91 }; 92 93 int ip_gif_ttl = GIF_TTL; 94 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 95 &ip_gif_ttl, 0, "TTL of GIF packet"); 96 97 int 98 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 99 { 100 struct gif_softc *sc = (struct gif_softc*)ifp; 101 struct route *ro = &sc->gif_ro[mycpu->gd_cpuid]; 102 struct sockaddr_in *dst = (struct sockaddr_in *)&ro->ro_dst; 103 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 104 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 105 struct ip iphdr; /* capsule IP header, host byte ordered */ 106 int proto, error; 107 u_int8_t tos; 108 109 if (sin_src == NULL || sin_dst == NULL || 110 sin_src->sin_family != AF_INET || 111 sin_dst->sin_family != AF_INET) { 112 m_freem(m); 113 return EAFNOSUPPORT; 114 } 115 116 switch (family) { 117 #ifdef INET 118 case AF_INET: 119 { 120 struct ip *ip; 121 122 proto = IPPROTO_IPV4; 123 if (m->m_len < sizeof *ip) { 124 m = m_pullup(m, sizeof *ip); 125 if (!m) 126 return ENOBUFS; 127 } 128 ip = mtod(m, struct ip *); 129 tos = ip->ip_tos; 130 break; 131 } 132 #endif 133 #ifdef INET6 134 case AF_INET6: 135 { 136 struct ip6_hdr *ip6; 137 proto = IPPROTO_IPV6; 138 if (m->m_len < sizeof *ip6) { 139 m = m_pullup(m, sizeof *ip6); 140 if (!m) 141 return ENOBUFS; 142 } 143 ip6 = mtod(m, struct ip6_hdr *); 144 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 145 break; 146 } 147 #endif 148 default: 149 #ifdef DEBUG 150 kprintf("in_gif_output: warning: unknown family %d passed\n", 151 family); 152 #endif 153 m_freem(m); 154 return EAFNOSUPPORT; 155 } 156 157 bzero(&iphdr, sizeof iphdr); 158 iphdr.ip_src = sin_src->sin_addr; 159 /* bidirectional configured tunnel mode */ 160 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 161 iphdr.ip_dst = sin_dst->sin_addr; 162 else { 163 m_freem(m); 164 return ENETUNREACH; 165 } 166 iphdr.ip_p = proto; 167 /* version will be set in ip_output() */ 168 iphdr.ip_ttl = ip_gif_ttl; 169 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 170 if (ifp->if_flags & IFF_LINK1) 171 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 172 else 173 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 174 175 /* prepend new IP header */ 176 M_PREPEND(m, sizeof(struct ip), M_NOWAIT); 177 if (m && m->m_len < sizeof(struct ip)) 178 m = m_pullup(m, sizeof(struct ip)); 179 if (m == NULL) { 180 kprintf("ENOBUFS in in_gif_output %d\n", __LINE__); 181 return ENOBUFS; 182 } 183 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 184 185 if (dst->sin_family != sin_dst->sin_family || 186 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 187 /* cache route doesn't match */ 188 dst->sin_family = sin_dst->sin_family; 189 dst->sin_len = sizeof(struct sockaddr_in); 190 dst->sin_addr = sin_dst->sin_addr; 191 if (ro->ro_rt != NULL) { 192 RTFREE(ro->ro_rt); 193 ro->ro_rt = NULL; 194 } 195 #if 0 196 sc->gif_if.if_mtu = GIF_MTU; 197 #endif 198 } 199 200 if (ro->ro_rt == NULL) { 201 rtalloc(ro); 202 if (ro->ro_rt == NULL) { 203 m_freem(m); 204 return ENETUNREACH; 205 } 206 207 /* if it constitutes infinite encapsulation, punt. */ 208 if (ro->ro_rt->rt_ifp == ifp) { 209 m_freem(m); 210 return ENETUNREACH; /* XXX */ 211 } 212 #if 0 213 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu - sizeof(struct ip); 214 #endif 215 } 216 217 error = ip_output(m, NULL, ro, 0, NULL, NULL); 218 return(error); 219 } 220 221 int 222 in_gif_input(struct mbuf **mp, int *offp, int proto) 223 { 224 struct mbuf *m = *mp; 225 struct ifnet *gifp = NULL; 226 struct ip *ip; 227 int af; 228 u_int8_t otos; 229 int off; 230 231 off = *offp; 232 *mp = NULL; 233 234 ip = mtod(m, struct ip *); 235 236 gifp = (struct ifnet *)encap_getarg(m); 237 238 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 239 m_freem(m); 240 ipstat.ips_nogif++; 241 return(IPPROTO_DONE); 242 } 243 244 otos = ip->ip_tos; 245 m_adj(m, off); 246 247 switch (proto) { 248 #ifdef INET 249 case IPPROTO_IPV4: 250 { 251 struct ip *ip; 252 af = AF_INET; 253 if (m->m_len < sizeof *ip) { 254 m = m_pullup(m, sizeof *ip); 255 if (!m) 256 return(IPPROTO_DONE); 257 } 258 ip = mtod(m, struct ip *); 259 if (gifp->if_flags & IFF_LINK1) 260 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 261 else 262 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 263 break; 264 } 265 #endif 266 #ifdef INET6 267 case IPPROTO_IPV6: 268 { 269 struct ip6_hdr *ip6; 270 u_int8_t itos; 271 af = AF_INET6; 272 if (m->m_len < sizeof *ip6) { 273 m = m_pullup(m, sizeof *ip6); 274 if (!m) 275 return(IPPROTO_DONE); 276 } 277 ip6 = mtod(m, struct ip6_hdr *); 278 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 279 if (gifp->if_flags & IFF_LINK1) 280 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 281 else 282 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 283 ip6->ip6_flow &= ~htonl(0xff << 20); 284 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 285 break; 286 } 287 #endif /* INET6 */ 288 default: 289 ipstat.ips_nogif++; 290 m_freem(m); 291 return(IPPROTO_DONE); 292 } 293 gif_input(m, af, gifp); 294 return(IPPROTO_DONE); 295 } 296 297 /* 298 * validate outer address. 299 */ 300 static int 301 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 302 { 303 struct sockaddr_in *src, *dst; 304 struct in_ifaddr_container *iac; 305 306 src = (struct sockaddr_in *)sc->gif_psrc; 307 dst = (struct sockaddr_in *)sc->gif_pdst; 308 309 /* check for address match */ 310 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 311 dst->sin_addr.s_addr != ip->ip_src.s_addr) 312 return 0; 313 314 /* martian filters on outer source - NOT done in ip_input! */ 315 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 316 return 0; 317 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 318 case 0: case 127: case 255: 319 return 0; 320 } 321 /* reject packets with broadcast on source */ 322 TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) { 323 struct in_ifaddr *ia4 = iac->ia; 324 325 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST)) 326 continue; 327 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 328 return 0; 329 } 330 331 /* ingress filters on outer source */ 332 if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) { 333 struct sockaddr_in sin; 334 struct rtentry *rt; 335 336 bzero(&sin, sizeof sin); 337 sin.sin_family = AF_INET; 338 sin.sin_len = sizeof(struct sockaddr_in); 339 sin.sin_addr = ip->ip_src; 340 rt = rtpurelookup((struct sockaddr *)&sin); 341 if (rt != NULL) 342 --rt->rt_refcnt; 343 if (rt == NULL || rt->rt_ifp != ifp) { 344 #if 0 345 log(LOG_WARNING, "%s: packet from 0x%x dropped " 346 "due to ingress filter\n", if_name(&sc->gif_if), 347 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 348 #endif 349 return 0; 350 } 351 } 352 353 return 32 * 2; 354 } 355 356 /* 357 * we know that we are in IFF_UP, outer address available, and outer family 358 * matched the physical addr family. see gif_encapcheck(). 359 */ 360 int 361 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 362 { 363 struct ip ip; 364 struct gif_softc *sc; 365 struct ifnet *ifp; 366 367 /* sanity check done in caller */ 368 sc = (struct gif_softc *)arg; 369 370 /* LINTED const cast */ 371 m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip); 372 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 373 374 return gif_validate4(&ip, sc, ifp); 375 } 376 377 int 378 in_gif_attach(struct gif_softc *sc) 379 { 380 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 381 &in_gif_protosw, sc); 382 if (sc->encap_cookie4 == NULL) 383 return EEXIST; 384 return 0; 385 } 386 387 int 388 in_gif_detach(struct gif_softc *sc) 389 { 390 int error; 391 392 error = encap_detach(sc->encap_cookie4); 393 if (error == 0) 394 sc->encap_cookie4 = NULL; 395 return error; 396 } 397 398 #endif /* INET */ 399