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 1.15 2005/03/04 03:48:25 hsu 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 { SOCK_RAW, &inetdomain, 0/*IPPROTO_IPV[46]*/, PR_ATOMIC|PR_ADDR, 80 in_gif_input, rip_output, 0, rip_ctloutput, 81 cpu0_soport, 82 0, 0, 0, 0, 83 &rip_usrreqs 84 }; 85 86 int ip_gif_ttl = GIF_TTL; 87 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 88 &ip_gif_ttl, 0, ""); 89 90 int 91 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 92 { 93 struct gif_softc *sc = (struct gif_softc*)ifp; 94 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 95 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 96 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 97 struct ip iphdr; /* capsule IP header, host byte ordered */ 98 int proto, error; 99 u_int8_t tos; 100 101 if (sin_src == NULL || sin_dst == NULL || 102 sin_src->sin_family != AF_INET || 103 sin_dst->sin_family != AF_INET) { 104 m_freem(m); 105 return EAFNOSUPPORT; 106 } 107 108 switch (family) { 109 #ifdef INET 110 case AF_INET: 111 { 112 struct ip *ip; 113 114 proto = IPPROTO_IPV4; 115 if (m->m_len < sizeof *ip) { 116 m = m_pullup(m, sizeof *ip); 117 if (!m) 118 return ENOBUFS; 119 } 120 ip = mtod(m, struct ip *); 121 tos = ip->ip_tos; 122 break; 123 } 124 #endif 125 #ifdef INET6 126 case AF_INET6: 127 { 128 struct ip6_hdr *ip6; 129 proto = IPPROTO_IPV6; 130 if (m->m_len < sizeof *ip6) { 131 m = m_pullup(m, sizeof *ip6); 132 if (!m) 133 return ENOBUFS; 134 } 135 ip6 = mtod(m, struct ip6_hdr *); 136 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 137 break; 138 } 139 #endif 140 default: 141 #ifdef DEBUG 142 printf("in_gif_output: warning: unknown family %d passed\n", 143 family); 144 #endif 145 m_freem(m); 146 return EAFNOSUPPORT; 147 } 148 149 bzero(&iphdr, sizeof iphdr); 150 iphdr.ip_src = sin_src->sin_addr; 151 /* bidirectional configured tunnel mode */ 152 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 153 iphdr.ip_dst = sin_dst->sin_addr; 154 else { 155 m_freem(m); 156 return ENETUNREACH; 157 } 158 iphdr.ip_p = proto; 159 /* version will be set in ip_output() */ 160 iphdr.ip_ttl = ip_gif_ttl; 161 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 162 if (ifp->if_flags & IFF_LINK1) 163 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 164 else 165 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 166 167 /* prepend new IP header */ 168 M_PREPEND(m, sizeof(struct ip), MB_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 dst->sin_family = sin_dst->sin_family; 181 dst->sin_len = sizeof(struct sockaddr_in); 182 dst->sin_addr = sin_dst->sin_addr; 183 if (sc->gif_ro.ro_rt != NULL) { 184 RTFREE(sc->gif_ro.ro_rt); 185 sc->gif_ro.ro_rt = NULL; 186 } 187 #if 0 188 sc->gif_if.if_mtu = GIF_MTU; 189 #endif 190 } 191 192 if (sc->gif_ro.ro_rt == NULL) { 193 rtalloc(&sc->gif_ro); 194 if (sc->gif_ro.ro_rt == NULL) { 195 m_freem(m); 196 return ENETUNREACH; 197 } 198 199 /* if it constitutes infinite encapsulation, punt. */ 200 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 201 m_freem(m); 202 return ENETUNREACH; /* XXX */ 203 } 204 #if 0 205 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu - 206 sizeof(struct ip); 207 #endif 208 } 209 210 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 211 return(error); 212 } 213 214 void 215 in_gif_input(struct mbuf *m, ...) 216 { 217 struct ifnet *gifp = NULL; 218 struct ip *ip; 219 int af; 220 u_int8_t otos; 221 int off, proto; 222 __va_list ap; 223 224 __va_start(ap, m); 225 off = __va_arg(ap, int); 226 proto = __va_arg(ap, int); 227 __va_end(ap); 228 229 ip = mtod(m, struct ip *); 230 231 gifp = (struct ifnet *)encap_getarg(m); 232 233 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 234 m_freem(m); 235 ipstat.ips_nogif++; 236 return; 237 } 238 239 otos = ip->ip_tos; 240 m_adj(m, off); 241 242 switch (proto) { 243 #ifdef INET 244 case IPPROTO_IPV4: 245 { 246 struct ip *ip; 247 af = AF_INET; 248 if (m->m_len < sizeof *ip) { 249 m = m_pullup(m, sizeof *ip); 250 if (!m) 251 return; 252 } 253 ip = mtod(m, struct ip *); 254 if (gifp->if_flags & IFF_LINK1) 255 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 256 else 257 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 258 break; 259 } 260 #endif 261 #ifdef INET6 262 case IPPROTO_IPV6: 263 { 264 struct ip6_hdr *ip6; 265 u_int8_t itos; 266 af = AF_INET6; 267 if (m->m_len < sizeof *ip6) { 268 m = m_pullup(m, sizeof *ip6); 269 if (!m) 270 return; 271 } 272 ip6 = mtod(m, struct ip6_hdr *); 273 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 274 if (gifp->if_flags & IFF_LINK1) 275 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 276 else 277 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 278 ip6->ip6_flow &= ~htonl(0xff << 20); 279 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 280 break; 281 } 282 #endif /* INET6 */ 283 default: 284 ipstat.ips_nogif++; 285 m_freem(m); 286 return; 287 } 288 gif_input(m, af, gifp); 289 return; 290 } 291 292 /* 293 * validate outer address. 294 */ 295 static int 296 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 297 { 298 struct sockaddr_in *src, *dst; 299 struct in_ifaddr *ia4; 300 301 src = (struct sockaddr_in *)sc->gif_psrc; 302 dst = (struct sockaddr_in *)sc->gif_pdst; 303 304 /* check for address match */ 305 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 306 dst->sin_addr.s_addr != ip->ip_src.s_addr) 307 return 0; 308 309 /* martian filters on outer source - NOT done in ip_input! */ 310 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 311 return 0; 312 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 313 case 0: case 127: case 255: 314 return 0; 315 } 316 /* reject packets with broadcast on source */ 317 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) { 318 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST)) 319 continue; 320 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 321 return 0; 322 } 323 324 /* ingress filters on outer source */ 325 if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) { 326 struct sockaddr_in sin; 327 struct rtentry *rt; 328 329 bzero(&sin, sizeof sin); 330 sin.sin_family = AF_INET; 331 sin.sin_len = sizeof(struct sockaddr_in); 332 sin.sin_addr = ip->ip_src; 333 rt = rtpurelookup((struct sockaddr *)&sin); 334 if (rt != NULL) 335 --rt->rt_refcnt; 336 if (rt == NULL || rt->rt_ifp != ifp) { 337 #if 0 338 log(LOG_WARNING, "%s: packet from 0x%x dropped " 339 "due to ingress filter\n", if_name(&sc->gif_if), 340 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 341 #endif 342 return 0; 343 } 344 } 345 346 return 32 * 2; 347 } 348 349 /* 350 * we know that we are in IFF_UP, outer address available, and outer family 351 * matched the physical addr family. see gif_encapcheck(). 352 */ 353 int 354 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 355 { 356 struct ip ip; 357 struct gif_softc *sc; 358 struct ifnet *ifp; 359 360 /* sanity check done in caller */ 361 sc = (struct gif_softc *)arg; 362 363 /* LINTED const cast */ 364 m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip); 365 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 366 367 return gif_validate4(&ip, sc, ifp); 368 } 369 370 int 371 in_gif_attach(struct gif_softc *sc) 372 { 373 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 374 &in_gif_protosw, sc); 375 if (sc->encap_cookie4 == NULL) 376 return EEXIST; 377 return 0; 378 } 379 380 int 381 in_gif_detach(struct gif_softc *sc) 382 { 383 int error; 384 385 error = encap_detach(sc->encap_cookie4); 386 if (error == 0) 387 sc->encap_cookie4 = NULL; 388 return error; 389 } 390 391 #endif /* INET */ 392