1 /* $FreeBSD$ */ 2 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 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 <net/net_osdep.h> 71 72 int ip_gif_ttl = GIF_TTL; 73 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 74 &ip_gif_ttl, 0, ""); 75 76 int 77 in_gif_output(ifp, family, m, rt) 78 struct ifnet *ifp; 79 int family; 80 struct mbuf *m; 81 struct rtentry *rt; 82 { 83 struct gif_softc *sc = (struct gif_softc*)ifp; 84 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 85 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 86 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 87 struct ip iphdr; /* capsule IP header, host byte ordered */ 88 int proto, error; 89 u_int8_t tos; 90 91 if (sin_src == NULL || sin_dst == NULL || 92 sin_src->sin_family != AF_INET || 93 sin_dst->sin_family != AF_INET) { 94 m_freem(m); 95 return EAFNOSUPPORT; 96 } 97 98 switch (family) { 99 #ifdef INET 100 case AF_INET: 101 { 102 struct ip *ip; 103 104 proto = IPPROTO_IPV4; 105 if (m->m_len < sizeof(*ip)) { 106 m = m_pullup(m, sizeof(*ip)); 107 if (!m) 108 return ENOBUFS; 109 } 110 ip = mtod(m, struct ip *); 111 tos = ip->ip_tos; 112 break; 113 } 114 #endif /*INET*/ 115 #ifdef INET6 116 case AF_INET6: 117 { 118 struct ip6_hdr *ip6; 119 proto = IPPROTO_IPV6; 120 if (m->m_len < sizeof(*ip6)) { 121 m = m_pullup(m, sizeof(*ip6)); 122 if (!m) 123 return ENOBUFS; 124 } 125 ip6 = mtod(m, struct ip6_hdr *); 126 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 127 break; 128 } 129 #endif /*INET6*/ 130 default: 131 #ifdef DEBUG 132 printf("in_gif_output: warning: unknown family %d passed\n", 133 family); 134 #endif 135 m_freem(m); 136 return EAFNOSUPPORT; 137 } 138 139 bzero(&iphdr, sizeof(iphdr)); 140 iphdr.ip_src = sin_src->sin_addr; 141 /* bidirectional configured tunnel mode */ 142 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 143 iphdr.ip_dst = sin_dst->sin_addr; 144 else { 145 m_freem(m); 146 return ENETUNREACH; 147 } 148 iphdr.ip_p = proto; 149 /* version will be set in ip_output() */ 150 iphdr.ip_ttl = ip_gif_ttl; 151 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 152 if (ifp->if_flags & IFF_LINK1) 153 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 154 else 155 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 156 157 /* prepend new IP header */ 158 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 159 if (m && m->m_len < sizeof(struct ip)) 160 m = m_pullup(m, sizeof(struct ip)); 161 if (m == NULL) { 162 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 163 return ENOBUFS; 164 } 165 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 166 167 if (dst->sin_family != sin_dst->sin_family || 168 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 169 /* cache route doesn't match */ 170 dst->sin_family = sin_dst->sin_family; 171 dst->sin_len = sizeof(struct sockaddr_in); 172 dst->sin_addr = sin_dst->sin_addr; 173 if (sc->gif_ro.ro_rt) { 174 RTFREE(sc->gif_ro.ro_rt); 175 sc->gif_ro.ro_rt = NULL; 176 } 177 #if 0 178 sc->gif_if.if_mtu = GIF_MTU; 179 #endif 180 } 181 182 if (sc->gif_ro.ro_rt == NULL) { 183 rtalloc(&sc->gif_ro); 184 if (sc->gif_ro.ro_rt == NULL) { 185 m_freem(m); 186 return ENETUNREACH; 187 } 188 189 /* if it constitutes infinite encapsulation, punt. */ 190 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 191 m_freem(m); 192 return ENETUNREACH; /*XXX*/ 193 } 194 #if 0 195 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 196 - sizeof(struct ip); 197 #endif 198 } 199 200 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 201 return(error); 202 } 203 204 void 205 in_gif_input(m, off) 206 struct mbuf *m; 207 int off; 208 { 209 struct ifnet *gifp = NULL; 210 struct ip *ip; 211 int af; 212 u_int8_t otos; 213 int proto; 214 215 ip = mtod(m, struct ip *); 216 proto = ip->ip_p; 217 218 gifp = (struct ifnet *)encap_getarg(m); 219 220 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 221 m_freem(m); 222 ipstat.ips_nogif++; 223 return; 224 } 225 226 otos = ip->ip_tos; 227 m_adj(m, off); 228 229 switch (proto) { 230 #ifdef INET 231 case IPPROTO_IPV4: 232 { 233 struct ip *ip; 234 af = AF_INET; 235 if (m->m_len < sizeof(*ip)) { 236 m = m_pullup(m, sizeof(*ip)); 237 if (!m) 238 return; 239 } 240 ip = mtod(m, struct ip *); 241 if (gifp->if_flags & IFF_LINK1) 242 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 243 else 244 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 245 break; 246 } 247 #endif 248 #ifdef INET6 249 case IPPROTO_IPV6: 250 { 251 struct ip6_hdr *ip6; 252 u_int8_t itos; 253 af = AF_INET6; 254 if (m->m_len < sizeof(*ip6)) { 255 m = m_pullup(m, sizeof(*ip6)); 256 if (!m) 257 return; 258 } 259 ip6 = mtod(m, struct ip6_hdr *); 260 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 261 if (gifp->if_flags & IFF_LINK1) 262 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 263 else 264 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 265 ip6->ip6_flow &= ~htonl(0xff << 20); 266 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 267 break; 268 } 269 #endif /* INET6 */ 270 default: 271 ipstat.ips_nogif++; 272 m_freem(m); 273 return; 274 } 275 gif_input(m, af, gifp); 276 return; 277 } 278 279 /* 280 * we know that we are in IFF_UP, outer address available, and outer family 281 * matched the physical addr family. see gif_encapcheck(). 282 */ 283 int 284 gif_encapcheck4(m, off, proto, arg) 285 const struct mbuf *m; 286 int off; 287 int proto; 288 void *arg; 289 { 290 struct ip ip; 291 struct gif_softc *sc; 292 struct sockaddr_in *src, *dst; 293 int addrmatch; 294 struct in_ifaddr *ia4; 295 296 /* sanity check done in caller */ 297 sc = (struct gif_softc *)arg; 298 src = (struct sockaddr_in *)sc->gif_psrc; 299 dst = (struct sockaddr_in *)sc->gif_pdst; 300 301 /* LINTED const cast */ 302 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 303 304 /* check for address match */ 305 addrmatch = 0; 306 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) 307 addrmatch |= 1; 308 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) 309 addrmatch |= 2; 310 if (addrmatch != 3) 311 return 0; 312 313 /* martian filters on outer source - NOT done in ip_input! */ 314 if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) 315 return 0; 316 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) { 317 case 0: case 127: case 255: 318 return 0; 319 } 320 /* reject packets with broadcast on source */ 321 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) 322 { 323 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 324 continue; 325 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 326 return 0; 327 } 328 329 /* ingress filters on outer source */ 330 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && 331 (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) { 332 struct sockaddr_in sin; 333 struct rtentry *rt; 334 335 bzero(&sin, sizeof(sin)); 336 sin.sin_family = AF_INET; 337 sin.sin_len = sizeof(struct sockaddr_in); 338 sin.sin_addr = ip.ip_src; 339 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 340 if (!rt || rt->rt_ifp != m->m_pkthdr.rcvif) { 341 #if 0 342 log(LOG_WARNING, "%s: packet from 0x%x dropped " 343 "due to ingress filter\n", if_name(&sc->gif_if), 344 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 345 #endif 346 if (rt) 347 rtfree(rt); 348 return 0; 349 } 350 rtfree(rt); 351 } 352 353 return 32 * 2; 354 } 355