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 "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 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 /* bidirectional configured tunnel mode */ 150 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 151 iphdr.ip_dst = sin_dst->sin_addr; 152 else { 153 m_freem(m); 154 return ENETUNREACH; 155 } 156 iphdr.ip_p = proto; 157 /* version will be set in ip_output() */ 158 iphdr.ip_ttl = ip_gif_ttl; 159 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 160 if (ifp->if_flags & IFF_LINK1) 161 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 162 else 163 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 164 165 /* prepend new IP header */ 166 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 167 if (m && m->m_len < sizeof(struct ip)) 168 m = m_pullup(m, sizeof(struct ip)); 169 if (m == NULL) { 170 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 171 return ENOBUFS; 172 } 173 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 174 175 if (dst->sin_family != sin_dst->sin_family || 176 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 177 /* cache route doesn't match */ 178 dst->sin_family = sin_dst->sin_family; 179 dst->sin_len = sizeof(struct sockaddr_in); 180 dst->sin_addr = sin_dst->sin_addr; 181 if (sc->gif_ro.ro_rt) { 182 RTFREE(sc->gif_ro.ro_rt); 183 sc->gif_ro.ro_rt = NULL; 184 } 185 #if 0 186 sc->gif_if.if_mtu = GIF_MTU; 187 #endif 188 } 189 190 if (sc->gif_ro.ro_rt == NULL) { 191 rtalloc(&sc->gif_ro); 192 if (sc->gif_ro.ro_rt == NULL) { 193 m_freem(m); 194 return ENETUNREACH; 195 } 196 197 /* if it constitutes infinite encapsulation, punt. */ 198 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 199 m_freem(m); 200 return ENETUNREACH; /*XXX*/ 201 } 202 #if 0 203 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 204 - sizeof(struct ip); 205 #endif 206 } 207 208 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL); 209 return(error); 210 } 211 212 void 213 #if __STDC__ 214 in_gif_input(struct mbuf *m, ...) 215 #else 216 in_gif_input(m, va_alist) 217 struct mbuf *m; 218 va_dcl 219 #endif 220 { 221 int off, proto; 222 struct ifnet *gifp = NULL; 223 struct ip *ip; 224 va_list ap; 225 int af; 226 u_int8_t otos; 227 228 va_start(ap, m); 229 off = va_arg(ap, int); 230 proto = va_arg(ap, int); 231 va_end(ap); 232 233 ip = mtod(m, struct ip *); 234 235 gifp = (struct ifnet *)encap_getarg(m); 236 237 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 238 m_freem(m); 239 ipstat.ips_nogif++; 240 return; 241 } 242 243 otos = ip->ip_tos; 244 m_adj(m, off); 245 246 switch (proto) { 247 #ifdef INET 248 case IPPROTO_IPV4: 249 { 250 struct ip *ip; 251 af = AF_INET; 252 if (m->m_len < sizeof(*ip)) { 253 m = m_pullup(m, sizeof(*ip)); 254 if (!m) 255 return; 256 } 257 ip = mtod(m, struct ip *); 258 if (gifp->if_flags & IFF_LINK1) 259 ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos); 260 else 261 ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos); 262 break; 263 } 264 #endif 265 #ifdef INET6 266 case IPPROTO_IPV6: 267 { 268 struct ip6_hdr *ip6; 269 u_int8_t itos; 270 af = AF_INET6; 271 if (m->m_len < sizeof(*ip6)) { 272 m = m_pullup(m, sizeof(*ip6)); 273 if (!m) 274 return; 275 } 276 ip6 = mtod(m, struct ip6_hdr *); 277 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 278 if (gifp->if_flags & IFF_LINK1) 279 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 280 else 281 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 282 ip6->ip6_flow &= ~htonl(0xff << 20); 283 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 284 break; 285 } 286 #endif /* INET6 */ 287 default: 288 ipstat.ips_nogif++; 289 m_freem(m); 290 return; 291 } 292 gif_input(m, af, gifp); 293 return; 294 } 295 296 /* 297 * we know that we are in IFF_UP, outer address available, and outer family 298 * matched the physical addr family. see gif_encapcheck(). 299 */ 300 int 301 gif_encapcheck4(m, off, proto, arg) 302 const struct mbuf *m; 303 int off; 304 int proto; 305 void *arg; 306 { 307 struct ip ip; 308 struct gif_softc *sc; 309 struct sockaddr_in *src, *dst; 310 int addrmatch; 311 struct in_ifaddr *ia4; 312 313 /* sanity check done in caller */ 314 sc = (struct gif_softc *)arg; 315 src = (struct sockaddr_in *)sc->gif_psrc; 316 dst = (struct sockaddr_in *)sc->gif_pdst; 317 318 /* LINTED const cast */ 319 m_copydata((struct mbuf *)m, 0, sizeof(ip), (caddr_t)&ip); 320 321 /* check for address match */ 322 addrmatch = 0; 323 if (src->sin_addr.s_addr == ip.ip_dst.s_addr) 324 addrmatch |= 1; 325 if (dst->sin_addr.s_addr == ip.ip_src.s_addr) 326 addrmatch |= 2; 327 if (addrmatch != 3) 328 return 0; 329 330 /* martian filters on outer source - NOT done in ip_input! */ 331 if (IN_MULTICAST(ntohl(ip.ip_src.s_addr))) 332 return 0; 333 switch ((ntohl(ip.ip_src.s_addr) & 0xff000000) >> 24) { 334 case 0: case 127: case 255: 335 return 0; 336 } 337 /* reject packets with broadcast on source */ 338 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) 339 { 340 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 341 continue; 342 if (ip.ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 343 return 0; 344 } 345 346 /* ingress filters on outer source */ 347 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && 348 (m->m_flags & M_PKTHDR) != 0 && m->m_pkthdr.rcvif) { 349 struct sockaddr_in sin; 350 struct rtentry *rt; 351 352 bzero(&sin, sizeof(sin)); 353 sin.sin_family = AF_INET; 354 sin.sin_len = sizeof(struct sockaddr_in); 355 sin.sin_addr = ip.ip_src; 356 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 357 if (!rt || rt->rt_ifp != m->m_pkthdr.rcvif) { 358 #if 0 359 log(LOG_WARNING, "%s: packet from 0x%x dropped " 360 "due to ingress filter\n", if_name(&sc->gif_if), 361 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 362 #endif 363 if (rt) 364 rtfree(rt); 365 return 0; 366 } 367 rtfree(rt); 368 } 369 370 return 32 * 2; 371 } 372