1 /* 2 * $FreeBSD: src/sys/netinet/in_gif.c,v 1.5.2.11 2003/01/23 21:06:45 sam Exp $ 3 * $DragonFly: src/sys/netinet/in_gif.c,v 1.18 2008/10/27 02:56:30 sephe Exp $ 4 * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ 5 */ 6 /* 7 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the project nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/socket.h> 41 #include <sys/sockio.h> 42 #include <sys/mbuf.h> 43 #include <sys/errno.h> 44 #include <sys/kernel.h> 45 #include <sys/sysctl.h> 46 #include <sys/protosw.h> 47 48 #include <sys/malloc.h> 49 50 #include <machine/stdarg.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/ip.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in_gif.h> 60 #include <netinet/in_var.h> 61 #include <netinet/ip_encap.h> 62 #include <netinet/ip_ecn.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #endif 67 68 #include <net/gif/if_gif.h> 69 #include <net/net_osdep.h> 70 71 #include <sys/thread2.h> /* ipstat */ 72 73 #ifdef INET 74 static int gif_validate4 (const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77 extern struct domain inetdomain; 78 const struct protosw in_gif_protosw = 79 { 80 .pr_type = SOCK_RAW, 81 .pr_domain = &inetdomain, 82 .pr_protocol = 0 /*IPPROTO_IPV[46]*/, 83 .pr_flags = PR_ATOMIC|PR_ADDR, 84 85 .pr_input = in_gif_input, 86 .pr_output = rip_output, 87 .pr_ctlinput = NULL, 88 .pr_ctloutput = rip_ctloutput, 89 90 .pr_ctlport = NULL, 91 .pr_usrreqs = &rip_usrreqs 92 }; 93 94 int ip_gif_ttl = GIF_TTL; 95 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 96 &ip_gif_ttl, 0, "TTL of GIF packet"); 97 98 int 99 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 100 { 101 struct gif_softc *sc = (struct gif_softc*)ifp; 102 struct route *ro = &sc->gif_ro[mycpu->gd_cpuid]; 103 struct sockaddr_in *dst = (struct sockaddr_in *)&ro->ro_dst; 104 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 105 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 106 struct ip iphdr; /* capsule IP header, host byte ordered */ 107 int proto, error; 108 u_int8_t tos; 109 110 if (sin_src == NULL || sin_dst == NULL || 111 sin_src->sin_family != AF_INET || 112 sin_dst->sin_family != AF_INET) { 113 m_freem(m); 114 return EAFNOSUPPORT; 115 } 116 117 switch (family) { 118 #ifdef INET 119 case AF_INET: 120 { 121 struct ip *ip; 122 123 proto = IPPROTO_IPV4; 124 if (m->m_len < sizeof *ip) { 125 m = m_pullup(m, sizeof *ip); 126 if (!m) 127 return ENOBUFS; 128 } 129 ip = mtod(m, struct ip *); 130 tos = ip->ip_tos; 131 break; 132 } 133 #endif 134 #ifdef INET6 135 case AF_INET6: 136 { 137 struct ip6_hdr *ip6; 138 proto = IPPROTO_IPV6; 139 if (m->m_len < sizeof *ip6) { 140 m = m_pullup(m, sizeof *ip6); 141 if (!m) 142 return ENOBUFS; 143 } 144 ip6 = mtod(m, struct ip6_hdr *); 145 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 146 break; 147 } 148 #endif 149 default: 150 #ifdef DEBUG 151 kprintf("in_gif_output: warning: unknown family %d passed\n", 152 family); 153 #endif 154 m_freem(m); 155 return EAFNOSUPPORT; 156 } 157 158 bzero(&iphdr, sizeof iphdr); 159 iphdr.ip_src = sin_src->sin_addr; 160 /* bidirectional configured tunnel mode */ 161 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 162 iphdr.ip_dst = sin_dst->sin_addr; 163 else { 164 m_freem(m); 165 return ENETUNREACH; 166 } 167 iphdr.ip_p = proto; 168 /* version will be set in ip_output() */ 169 iphdr.ip_ttl = ip_gif_ttl; 170 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 171 if (ifp->if_flags & IFF_LINK1) 172 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 173 else 174 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 175 176 /* prepend new IP header */ 177 M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT); 178 if (m && m->m_len < sizeof(struct ip)) 179 m = m_pullup(m, sizeof(struct ip)); 180 if (m == NULL) { 181 kprintf("ENOBUFS in in_gif_output %d\n", __LINE__); 182 return ENOBUFS; 183 } 184 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 185 186 if (dst->sin_family != sin_dst->sin_family || 187 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 188 /* cache route doesn't match */ 189 dst->sin_family = sin_dst->sin_family; 190 dst->sin_len = sizeof(struct sockaddr_in); 191 dst->sin_addr = sin_dst->sin_addr; 192 if (ro->ro_rt != NULL) { 193 RTFREE(ro->ro_rt); 194 ro->ro_rt = NULL; 195 } 196 #if 0 197 sc->gif_if.if_mtu = GIF_MTU; 198 #endif 199 } 200 201 if (ro->ro_rt == NULL) { 202 rtalloc(ro); 203 if (ro->ro_rt == NULL) { 204 m_freem(m); 205 return ENETUNREACH; 206 } 207 208 /* if it constitutes infinite encapsulation, punt. */ 209 if (ro->ro_rt->rt_ifp == ifp) { 210 m_freem(m); 211 return ENETUNREACH; /* XXX */ 212 } 213 #if 0 214 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu - sizeof(struct ip); 215 #endif 216 } 217 218 error = ip_output(m, NULL, ro, 0, NULL, NULL); 219 return(error); 220 } 221 222 int 223 in_gif_input(struct mbuf **mp, int *offp, int proto) 224 { 225 struct mbuf *m = *mp; 226 struct ifnet *gifp = NULL; 227 struct ip *ip; 228 int af; 229 u_int8_t otos; 230 int off; 231 232 off = *offp; 233 *mp = NULL; 234 235 ip = mtod(m, struct ip *); 236 237 gifp = (struct ifnet *)encap_getarg(m); 238 239 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 240 m_freem(m); 241 ipstat.ips_nogif++; 242 return(IPPROTO_DONE); 243 } 244 245 otos = ip->ip_tos; 246 m_adj(m, off); 247 248 switch (proto) { 249 #ifdef INET 250 case IPPROTO_IPV4: 251 { 252 struct ip *ip; 253 af = AF_INET; 254 if (m->m_len < sizeof *ip) { 255 m = m_pullup(m, sizeof *ip); 256 if (!m) 257 return(IPPROTO_DONE); 258 } 259 ip = mtod(m, struct ip *); 260 if (gifp->if_flags & IFF_LINK1) 261 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 262 else 263 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 264 break; 265 } 266 #endif 267 #ifdef INET6 268 case IPPROTO_IPV6: 269 { 270 struct ip6_hdr *ip6; 271 u_int8_t itos; 272 af = AF_INET6; 273 if (m->m_len < sizeof *ip6) { 274 m = m_pullup(m, sizeof *ip6); 275 if (!m) 276 return(IPPROTO_DONE); 277 } 278 ip6 = mtod(m, struct ip6_hdr *); 279 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 280 if (gifp->if_flags & IFF_LINK1) 281 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 282 else 283 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 284 ip6->ip6_flow &= ~htonl(0xff << 20); 285 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 286 break; 287 } 288 #endif /* INET6 */ 289 default: 290 ipstat.ips_nogif++; 291 m_freem(m); 292 return(IPPROTO_DONE); 293 } 294 gif_input(m, af, gifp); 295 return(IPPROTO_DONE); 296 } 297 298 /* 299 * validate outer address. 300 */ 301 static int 302 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 303 { 304 struct sockaddr_in *src, *dst; 305 struct in_ifaddr_container *iac; 306 307 src = (struct sockaddr_in *)sc->gif_psrc; 308 dst = (struct sockaddr_in *)sc->gif_pdst; 309 310 /* check for address match */ 311 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 312 dst->sin_addr.s_addr != ip->ip_src.s_addr) 313 return 0; 314 315 /* martian filters on outer source - NOT done in ip_input! */ 316 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 317 return 0; 318 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 319 case 0: case 127: case 255: 320 return 0; 321 } 322 /* reject packets with broadcast on source */ 323 TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) { 324 struct in_ifaddr *ia4 = iac->ia; 325 326 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST)) 327 continue; 328 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 329 return 0; 330 } 331 332 /* ingress filters on outer source */ 333 if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) { 334 struct sockaddr_in sin; 335 struct rtentry *rt; 336 337 bzero(&sin, sizeof sin); 338 sin.sin_family = AF_INET; 339 sin.sin_len = sizeof(struct sockaddr_in); 340 sin.sin_addr = ip->ip_src; 341 rt = rtpurelookup((struct sockaddr *)&sin); 342 if (rt != NULL) 343 --rt->rt_refcnt; 344 if (rt == NULL || rt->rt_ifp != ifp) { 345 #if 0 346 log(LOG_WARNING, "%s: packet from 0x%x dropped " 347 "due to ingress filter\n", if_name(&sc->gif_if), 348 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 349 #endif 350 return 0; 351 } 352 } 353 354 return 32 * 2; 355 } 356 357 /* 358 * we know that we are in IFF_UP, outer address available, and outer family 359 * matched the physical addr family. see gif_encapcheck(). 360 */ 361 int 362 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 363 { 364 struct ip ip; 365 struct gif_softc *sc; 366 struct ifnet *ifp; 367 368 /* sanity check done in caller */ 369 sc = (struct gif_softc *)arg; 370 371 /* LINTED const cast */ 372 m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip); 373 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 374 375 return gif_validate4(&ip, sc, ifp); 376 } 377 378 int 379 in_gif_attach(struct gif_softc *sc) 380 { 381 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 382 &in_gif_protosw, sc); 383 if (sc->encap_cookie4 == NULL) 384 return EEXIST; 385 return 0; 386 } 387 388 int 389 in_gif_detach(struct gif_softc *sc) 390 { 391 int error; 392 393 error = encap_detach(sc->encap_cookie4); 394 if (error == 0) 395 sc->encap_cookie4 = NULL; 396 return error; 397 } 398 399 #endif /* INET */ 400