1 /* $FreeBSD$ */ 2 /* $KAME: in_gif.c,v 1.44 2000/08/15 07:24:24 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 int 85 in_gif_output(ifp, family, m, rt) 86 struct ifnet *ifp; 87 int family; 88 struct mbuf *m; 89 struct rtentry *rt; 90 { 91 register struct gif_softc *sc = (struct gif_softc*)ifp; 92 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 93 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 94 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 95 struct ip iphdr; /* capsule IP header, host byte ordered */ 96 int proto, error; 97 u_int8_t tos; 98 99 if (sin_src == NULL || sin_dst == NULL || 100 sin_src->sin_family != AF_INET || 101 sin_dst->sin_family != AF_INET) { 102 m_freem(m); 103 return EAFNOSUPPORT; 104 } 105 106 switch (family) { 107 #ifdef INET 108 case AF_INET: 109 { 110 struct ip *ip; 111 112 proto = IPPROTO_IPV4; 113 if (m->m_len < sizeof(*ip)) { 114 m = m_pullup(m, sizeof(*ip)); 115 if (!m) 116 return ENOBUFS; 117 } 118 ip = mtod(m, struct ip *); 119 tos = ip->ip_tos; 120 break; 121 } 122 #endif /*INET*/ 123 #ifdef INET6 124 case AF_INET6: 125 { 126 struct ip6_hdr *ip6; 127 proto = IPPROTO_IPV6; 128 if (m->m_len < sizeof(*ip6)) { 129 m = m_pullup(m, sizeof(*ip6)); 130 if (!m) 131 return ENOBUFS; 132 } 133 ip6 = mtod(m, struct ip6_hdr *); 134 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 135 break; 136 } 137 #endif /*INET6*/ 138 default: 139 #ifdef DEBUG 140 printf("in_gif_output: warning: unknown family %d passed\n", 141 family); 142 #endif 143 m_freem(m); 144 return EAFNOSUPPORT; 145 } 146 147 bzero(&iphdr, sizeof(iphdr)); 148 iphdr.ip_src = sin_src->sin_addr; 149 if (ifp->if_flags & IFF_LINK0) { 150 /* multi-destination mode */ 151 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 152 iphdr.ip_dst = sin_dst->sin_addr; 153 else if (rt) { 154 if (family != AF_INET) { 155 m_freem(m); 156 return EINVAL; /*XXX*/ 157 } 158 iphdr.ip_dst = ((struct sockaddr_in *) 159 (rt->rt_gateway))->sin_addr; 160 } else { 161 m_freem(m); 162 return ENETUNREACH; 163 } 164 } else { 165 /* bidirectional configured tunnel mode */ 166 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 167 iphdr.ip_dst = sin_dst->sin_addr; 168 else { 169 m_freem(m); 170 return ENETUNREACH; 171 } 172 } 173 iphdr.ip_p = proto; 174 /* version will be set in ip_output() */ 175 iphdr.ip_ttl = ip_gif_ttl; 176 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 177 if (ifp->if_flags & IFF_LINK1) 178 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 179 180 /* prepend new IP header */ 181 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 182 if (m && m->m_len < sizeof(struct ip)) 183 m = m_pullup(m, sizeof(struct ip)); 184 if (m == NULL) { 185 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 186 return ENOBUFS; 187 } 188 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 189 190 if (dst->sin_family != sin_dst->sin_family || 191 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 192 /* cache route doesn't match */ 193 dst->sin_family = sin_dst->sin_family; 194 dst->sin_len = sizeof(struct sockaddr_in); 195 dst->sin_addr = sin_dst->sin_addr; 196 if (sc->gif_ro.ro_rt) { 197 RTFREE(sc->gif_ro.ro_rt); 198 sc->gif_ro.ro_rt = NULL; 199 } 200 #if 0 201 sc->gif_if.if_mtu = GIF_MTU; 202 #endif 203 } 204 205 if (sc->gif_ro.ro_rt == NULL) { 206 rtalloc(&sc->gif_ro); 207 if (sc->gif_ro.ro_rt == NULL) { 208 m_freem(m); 209 return ENETUNREACH; 210 } 211 212 /* if it constitutes infinite encapsulation, punt. */ 213 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 214 m_freem(m); 215 return ENETUNREACH; /*XXX*/ 216 } 217 #if 0 218 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 219 - sizeof(struct ip); 220 #endif 221 } 222 223 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 224 return(error); 225 } 226 227 void 228 #if __STDC__ 229 in_gif_input(struct mbuf *m, ...) 230 #else 231 in_gif_input(m, va_alist) 232 struct mbuf *m; 233 va_dcl 234 #endif 235 { 236 int off, proto; 237 struct ifnet *gifp = NULL; 238 struct ip *ip; 239 va_list ap; 240 int af; 241 u_int8_t otos; 242 243 va_start(ap, m); 244 off = va_arg(ap, int); 245 proto = va_arg(ap, int); 246 va_end(ap); 247 248 ip = mtod(m, struct ip *); 249 250 gifp = (struct ifnet *)encap_getarg(m); 251 252 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 253 m_freem(m); 254 ipstat.ips_nogif++; 255 return; 256 } 257 258 otos = ip->ip_tos; 259 m_adj(m, off); 260 261 switch (proto) { 262 #ifdef INET 263 case IPPROTO_IPV4: 264 { 265 struct ip *ip; 266 af = AF_INET; 267 if (m->m_len < sizeof(*ip)) { 268 m = m_pullup(m, sizeof(*ip)); 269 if (!m) 270 return; 271 } 272 ip = mtod(m, struct ip *); 273 if (gifp->if_flags & IFF_LINK1) 274 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 275 break; 276 } 277 #endif 278 #ifdef INET6 279 case IPPROTO_IPV6: 280 { 281 struct ip6_hdr *ip6; 282 u_int8_t itos; 283 af = AF_INET6; 284 if (m->m_len < sizeof(*ip6)) { 285 m = m_pullup(m, sizeof(*ip6)); 286 if (!m) 287 return; 288 } 289 ip6 = mtod(m, struct ip6_hdr *); 290 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 291 if (gifp->if_flags & IFF_LINK1) 292 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 293 ip6->ip6_flow &= ~htonl(0xff << 20); 294 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 295 break; 296 } 297 #endif /* INET6 */ 298 default: 299 ipstat.ips_nogif++; 300 m_freem(m); 301 return; 302 } 303 gif_input(m, af, gifp); 304 return; 305 } 306 307 /* 308 * we know that we are in IFF_UP, outer address available, and outer family 309 * matched the physical addr family. see gif_encapcheck(). 310 */ 311 int 312 gif_encapcheck4(m, off, proto, arg) 313 const struct mbuf *m; 314 int off; 315 int proto; 316 void *arg; 317 { 318 struct ip ip; 319 struct gif_softc *sc; 320 struct sockaddr_in *src, *dst; 321 int addrmatch; 322 struct in_ifaddr *ia4; 323 324 /* sanity check done in caller */ 325 sc = (struct gif_softc *)arg; 326 src = (struct sockaddr_in *)sc->gif_psrc; 327 dst = (struct sockaddr_in *)sc->gif_pdst; 328 329 /* LINTED const cast */ 330 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 331 332 /* check for address match */ 333 addrmatch = 0; 334 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) 335 addrmatch |= 1; 336 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) 337 addrmatch |= 2; 338 else if ((sc->gif_if.if_flags & IFF_LINK0) != 0 && 339 dst->sin_addr.s_addr == INADDR_ANY) { 340 addrmatch |= 2; /* we accept any source */ 341 } 342 if (addrmatch != 3) 343 return 0; 344 345 /* martian filters on outer source - NOT done in ip_input! */ 346 if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) 347 return 0; 348 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) { 349 case 0: case 127: case 255: 350 return 0; 351 } 352 /* reject packets with broadcast on source */ 353 for (ia4 = TAILQ_FIRST(&in_ifaddrhead); ia4; 354 ia4 = TAILQ_NEXT(ia4, ia_link)) 355 { 356 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 357 continue; 358 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 359 return 0; 360 } 361 362 /* ingress filters on outer source */ 363 if ((m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) { 364 struct sockaddr_in sin; 365 struct rtentry *rt; 366 367 bzero(&sin, sizeof(sin)); 368 sin.sin_family = AF_INET; 369 sin.sin_len = sizeof(struct sockaddr_in); 370 sin.sin_addr = ip.ip_src; 371 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 372 if (!rt) 373 return 0; 374 if (rt->rt_ifp != m->m_pkthdr.rcvif) { 375 rtfree(rt); 376 return 0; 377 } 378 rtfree(rt); 379 } 380 381 /* prioritize: IFF_LINK0 mode is less preferred */ 382 return (sc->gif_if.if_flags & IFF_LINK0) ? 32 : 32 * 2; 383 } 384