1 /* $FreeBSD$ */ 2 /* $KAME: in_gif.c,v 1.43 2000/06/20 19:45:00 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 46 #include <sys/malloc.h> 47 48 #include <net/if.h> 49 #include <net/route.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_systm.h> 53 #include <netinet/ip.h> 54 #include <netinet/ip_var.h> 55 #include <netinet/in_gif.h> 56 #include <netinet/in_var.h> 57 #include <netinet/ip_encap.h> 58 #include <netinet/ip_ecn.h> 59 60 #ifdef INET6 61 #include <netinet/ip6.h> 62 #endif 63 64 #ifdef MROUTING 65 #include <netinet/ip_mroute.h> 66 #endif /* MROUTING */ 67 68 #include <net/if_gif.h> 69 70 #include "gif.h" 71 72 #include <machine/stdarg.h> 73 74 #include <net/net_osdep.h> 75 76 #if NGIF > 0 77 int ip_gif_ttl = GIF_TTL; 78 #else 79 int ip_gif_ttl = 0; 80 #endif 81 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 82 &ip_gif_ttl, 0, ""); 83 84 #ifndef offsetof 85 #define offsetof(s, e) ((int)&((s *)0)->e) 86 #endif 87 88 int 89 in_gif_output(ifp, family, m, rt) 90 struct ifnet *ifp; 91 int family; 92 struct mbuf *m; 93 struct rtentry *rt; 94 { 95 register struct gif_softc *sc = (struct gif_softc*)ifp; 96 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 97 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 98 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 99 struct ip iphdr; /* capsule IP header, host byte ordered */ 100 int proto, error; 101 u_int8_t tos; 102 103 if (sin_src == NULL || sin_dst == NULL || 104 sin_src->sin_family != AF_INET || 105 sin_dst->sin_family != AF_INET) { 106 m_freem(m); 107 return EAFNOSUPPORT; 108 } 109 110 switch (family) { 111 #ifdef INET 112 case AF_INET: 113 { 114 struct ip *ip; 115 116 proto = IPPROTO_IPV4; 117 if (m->m_len < sizeof(*ip)) { 118 m = m_pullup(m, sizeof(*ip)); 119 if (!m) 120 return ENOBUFS; 121 } 122 ip = mtod(m, struct ip *); 123 tos = ip->ip_tos; 124 break; 125 } 126 #endif /*INET*/ 127 #ifdef INET6 128 case AF_INET6: 129 { 130 struct ip6_hdr *ip6; 131 proto = IPPROTO_IPV6; 132 if (m->m_len < sizeof(*ip6)) { 133 m = m_pullup(m, sizeof(*ip6)); 134 if (!m) 135 return ENOBUFS; 136 } 137 ip6 = mtod(m, struct ip6_hdr *); 138 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 139 break; 140 } 141 #endif /*INET6*/ 142 default: 143 #ifdef DEBUG 144 printf("in_gif_output: warning: unknown family %d passed\n", 145 family); 146 #endif 147 m_freem(m); 148 return EAFNOSUPPORT; 149 } 150 151 bzero(&iphdr, sizeof(iphdr)); 152 iphdr.ip_src = sin_src->sin_addr; 153 if (ifp->if_flags & IFF_LINK0) { 154 /* multi-destination mode */ 155 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 156 iphdr.ip_dst = sin_dst->sin_addr; 157 else if (rt) { 158 if (family != AF_INET) { 159 m_freem(m); 160 return EINVAL; /*XXX*/ 161 } 162 iphdr.ip_dst = ((struct sockaddr_in *) 163 (rt->rt_gateway))->sin_addr; 164 } else { 165 m_freem(m); 166 return ENETUNREACH; 167 } 168 } else { 169 /* bidirectional configured tunnel mode */ 170 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 171 iphdr.ip_dst = sin_dst->sin_addr; 172 else { 173 m_freem(m); 174 return ENETUNREACH; 175 } 176 } 177 iphdr.ip_p = proto; 178 /* version will be set in ip_output() */ 179 iphdr.ip_ttl = ip_gif_ttl; 180 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 181 if (ifp->if_flags & IFF_LINK1) 182 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 183 184 /* prepend new IP header */ 185 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 186 if (m && m->m_len < sizeof(struct ip)) 187 m = m_pullup(m, sizeof(struct ip)); 188 if (m == NULL) { 189 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 190 return ENOBUFS; 191 } 192 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 193 194 if (dst->sin_family != sin_dst->sin_family || 195 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 196 /* cache route doesn't match */ 197 dst->sin_family = sin_dst->sin_family; 198 dst->sin_len = sizeof(struct sockaddr_in); 199 dst->sin_addr = sin_dst->sin_addr; 200 if (sc->gif_ro.ro_rt) { 201 RTFREE(sc->gif_ro.ro_rt); 202 sc->gif_ro.ro_rt = NULL; 203 } 204 #if 0 205 sc->gif_if.if_mtu = GIF_MTU; 206 #endif 207 } 208 209 if (sc->gif_ro.ro_rt == NULL) { 210 rtalloc(&sc->gif_ro); 211 if (sc->gif_ro.ro_rt == NULL) { 212 m_freem(m); 213 return ENETUNREACH; 214 } 215 216 /* if it constitutes infinite encapsulation, punt. */ 217 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 218 m_freem(m); 219 return ENETUNREACH; /*XXX*/ 220 } 221 #if 0 222 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 223 - sizeof(struct ip); 224 #endif 225 } 226 227 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 228 return(error); 229 } 230 231 void 232 #if __STDC__ 233 in_gif_input(struct mbuf *m, ...) 234 #else 235 in_gif_input(m, va_alist) 236 struct mbuf *m; 237 va_dcl 238 #endif 239 { 240 int off, proto; 241 struct ifnet *gifp = NULL; 242 struct ip *ip; 243 va_list ap; 244 int af; 245 u_int8_t otos; 246 247 va_start(ap, m); 248 off = va_arg(ap, int); 249 proto = va_arg(ap, int); 250 va_end(ap); 251 252 ip = mtod(m, struct ip *); 253 254 gifp = (struct ifnet *)encap_getarg(m); 255 256 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 257 m_freem(m); 258 ipstat.ips_nogif++; 259 return; 260 } 261 262 otos = ip->ip_tos; 263 m_adj(m, off); 264 265 switch (proto) { 266 #ifdef INET 267 case IPPROTO_IPV4: 268 { 269 struct ip *ip; 270 af = AF_INET; 271 if (m->m_len < sizeof(*ip)) { 272 m = m_pullup(m, sizeof(*ip)); 273 if (!m) 274 return; 275 } 276 ip = mtod(m, struct ip *); 277 if (gifp->if_flags & IFF_LINK1) 278 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 279 break; 280 } 281 #endif 282 #ifdef INET6 283 case IPPROTO_IPV6: 284 { 285 struct ip6_hdr *ip6; 286 u_int8_t itos; 287 af = AF_INET6; 288 if (m->m_len < sizeof(*ip6)) { 289 m = m_pullup(m, sizeof(*ip6)); 290 if (!m) 291 return; 292 } 293 ip6 = mtod(m, struct ip6_hdr *); 294 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 295 if (gifp->if_flags & IFF_LINK1) 296 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 297 ip6->ip6_flow &= ~htonl(0xff << 20); 298 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 299 break; 300 } 301 #endif /* INET6 */ 302 default: 303 ipstat.ips_nogif++; 304 m_freem(m); 305 return; 306 } 307 gif_input(m, af, gifp); 308 return; 309 } 310 311 /* 312 * we know that we are in IFF_UP, outer address available, and outer family 313 * matched the physical addr family. see gif_encapcheck(). 314 */ 315 int 316 gif_encapcheck4(m, off, proto, arg) 317 const struct mbuf *m; 318 int off; 319 int proto; 320 void *arg; 321 { 322 struct ip ip; 323 struct gif_softc *sc; 324 struct sockaddr_in *src, *dst; 325 int addrmatch; 326 struct in_ifaddr *ia4; 327 328 /* sanity check done in caller */ 329 sc = (struct gif_softc *)arg; 330 src = (struct sockaddr_in *)sc->gif_psrc; 331 dst = (struct sockaddr_in *)sc->gif_pdst; 332 333 /* LINTED const cast */ 334 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 335 336 /* check for address match */ 337 addrmatch = 0; 338 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) 339 addrmatch |= 1; 340 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) 341 addrmatch |= 2; 342 else if ((sc->gif_if.if_flags & IFF_LINK0) != 0 && 343 dst->sin_addr.s_addr == INADDR_ANY) { 344 addrmatch |= 2; /* we accept any source */ 345 } 346 if (addrmatch != 3) 347 return 0; 348 349 /* martian filters on outer source - NOT done in ip_input! */ 350 if (IN_MULTICAST(ip.ip_src.s_addr)) 351 return 0; 352 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) { 353 case 0: case 127: case 255: 354 return 0; 355 } 356 /* reject packets with broadcast on source */ 357 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4; 358 ia4 = TAILQ_NEXT(ia4, ia_link)) 359 { 360 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 361 continue; 362 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 363 return 0; 364 } 365 366 /* ingress filters on outer source */ 367 if ((m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) { 368 struct sockaddr_in sin; 369 struct rtentry *rt; 370 371 bzero(&sin, sizeof(sin)); 372 sin.sin_family = AF_INET; 373 sin.sin_len = sizeof(struct sockaddr_in); 374 sin.sin_addr = ip.ip_src; 375 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 376 if (!rt) 377 return 0; 378 if (rt->rt_ifp != m->m_pkthdr.rcvif) { 379 rtfree(rt); 380 return 0; 381 } 382 rtfree(rt); 383 } 384 385 /* prioritize: IFF_LINK0 mode is less preferred */ 386 return (sc->gif_if.if_flags & IFF_LINK0) ? 32 : 32 * 2; 387 } 388