1 /* $NetBSD: in_gif.c,v 1.60 2008/11/07 00:20:18 dyoung Exp $ */ 2 /* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 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 <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: in_gif.c,v 1.60 2008/11/07 00:20:18 dyoung Exp $"); 35 36 #include "opt_inet.h" 37 #include "opt_iso.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/socket.h> 42 #include <sys/sockio.h> 43 #include <sys/mbuf.h> 44 #include <sys/errno.h> 45 #include <sys/ioctl.h> 46 #include <sys/syslog.h> 47 #include <sys/protosw.h> 48 #include <sys/kernel.h> 49 50 #include <net/if.h> 51 #include <net/route.h> 52 53 #include <netinet/in.h> 54 #include <netinet/in_systm.h> 55 #include <netinet/ip.h> 56 #include <netinet/ip_var.h> 57 #include <netinet/in_gif.h> 58 #include <netinet/in_var.h> 59 #include <netinet/ip_encap.h> 60 #include <netinet/ip_ecn.h> 61 62 #ifdef INET6 63 #include <netinet/ip6.h> 64 #endif 65 66 #include <net/if_gif.h> 67 68 #include "gif.h" 69 70 #include <machine/stdarg.h> 71 72 #include <net/net_osdep.h> 73 74 static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77 #if NGIF > 0 78 int ip_gif_ttl = GIF_TTL; 79 #else 80 int ip_gif_ttl = 0; 81 #endif 82 83 const struct protosw in_gif_protosw = 84 { SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR, 85 in_gif_input, rip_output, 0, rip_ctloutput, 86 rip_usrreq, 87 0, 0, 0, 0, 88 }; 89 90 int 91 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 92 { 93 struct rtentry *rt; 94 struct gif_softc *sc = ifp->if_softc; 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 union { 101 struct sockaddr dst; 102 struct sockaddr_in dst4; 103 } u; 104 105 if (sin_src == NULL || sin_dst == NULL || 106 sin_src->sin_family != AF_INET || 107 sin_dst->sin_family != AF_INET) { 108 m_freem(m); 109 return EAFNOSUPPORT; 110 } 111 112 switch (family) { 113 #ifdef INET 114 case AF_INET: 115 { 116 const struct ip *ip; 117 118 proto = IPPROTO_IPV4; 119 if (m->m_len < sizeof(*ip)) { 120 m = m_pullup(m, sizeof(*ip)); 121 if (m == NULL) 122 return ENOBUFS; 123 } 124 ip = mtod(m, const struct ip *); 125 tos = ip->ip_tos; 126 break; 127 } 128 #endif /* INET */ 129 #ifdef INET6 130 case AF_INET6: 131 { 132 const struct ip6_hdr *ip6; 133 proto = IPPROTO_IPV6; 134 if (m->m_len < sizeof(*ip6)) { 135 m = m_pullup(m, sizeof(*ip6)); 136 if (!m) 137 return ENOBUFS; 138 } 139 ip6 = mtod(m, const struct ip6_hdr *); 140 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 141 break; 142 } 143 #endif /* INET6 */ 144 #ifdef ISO 145 case AF_ISO: 146 proto = IPPROTO_EON; 147 tos = 0; 148 break; 149 #endif 150 default: 151 #ifdef DEBUG 152 printf("in_gif_output: warning: unknown family %d passed\n", 153 family); 154 #endif 155 m_freem(m); 156 return EAFNOSUPPORT; 157 } 158 159 memset(&iphdr, 0, sizeof(iphdr)); 160 iphdr.ip_src = sin_src->sin_addr; 161 /* bidirectional configured tunnel mode */ 162 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 163 iphdr.ip_dst = sin_dst->sin_addr; 164 else { 165 m_freem(m); 166 return ENETUNREACH; 167 } 168 iphdr.ip_p = proto; 169 /* version will be set in ip_output() */ 170 iphdr.ip_ttl = ip_gif_ttl; 171 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 172 if (ifp->if_flags & IFF_LINK1) 173 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 174 else 175 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 176 177 /* prepend new IP header */ 178 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 179 /* XXX Is m_pullup really necessary after M_PREPEND? */ 180 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 181 m = m_pullup(m, sizeof(struct ip)); 182 if (m == NULL) 183 return ENOBUFS; 184 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 185 186 sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0); 187 if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) { 188 m_freem(m); 189 return ENETUNREACH; 190 } 191 192 /* If the route constitutes infinite encapsulation, punt. */ 193 if (rt->rt_ifp == ifp) { 194 rtcache_free(&sc->gif_ro); 195 m_freem(m); 196 return ENETUNREACH; /*XXX*/ 197 } 198 199 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 200 return (error); 201 } 202 203 void 204 in_gif_input(struct mbuf *m, ...) 205 { 206 int off, proto; 207 struct ifnet *gifp = NULL; 208 const struct ip *ip; 209 va_list ap; 210 int af; 211 u_int8_t otos; 212 213 va_start(ap, m); 214 off = va_arg(ap, int); 215 proto = va_arg(ap, int); 216 va_end(ap); 217 218 ip = mtod(m, const struct ip *); 219 220 gifp = (struct ifnet *)encap_getarg(m); 221 222 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 223 m_freem(m); 224 ip_statinc(IP_STAT_NOGIF); 225 return; 226 } 227 #ifndef GIF_ENCAPCHECK 228 if (!gif_validate4(ip, gifp->if_softc, m->m_pkthdr.rcvif)) { 229 m_freem(m); 230 ip_statinc(IP_STAT_NOGIF); 231 return; 232 } 233 #endif 234 235 otos = ip->ip_tos; 236 m_adj(m, off); 237 238 switch (proto) { 239 #ifdef INET 240 case IPPROTO_IPV4: 241 { 242 struct ip *xip; 243 af = AF_INET; 244 if (M_UNWRITABLE(m, sizeof(*xip))) { 245 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 246 return; 247 } 248 xip = mtod(m, struct ip *); 249 if (gifp->if_flags & IFF_LINK1) 250 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 251 else 252 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 253 break; 254 } 255 #endif 256 #ifdef INET6 257 case IPPROTO_IPV6: 258 { 259 struct ip6_hdr *ip6; 260 u_int8_t itos; 261 af = AF_INET6; 262 if (M_UNWRITABLE(m, sizeof(*ip6))) { 263 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 264 return; 265 } 266 ip6 = mtod(m, struct ip6_hdr *); 267 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 268 if (gifp->if_flags & IFF_LINK1) 269 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 270 else 271 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 272 ip6->ip6_flow &= ~htonl(0xff << 20); 273 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 274 break; 275 } 276 #endif /* INET6 */ 277 #ifdef ISO 278 case IPPROTO_EON: 279 af = AF_ISO; 280 break; 281 #endif 282 default: 283 ip_statinc(IP_STAT_NOGIF); 284 m_freem(m); 285 return; 286 } 287 gif_input(m, af, gifp); 288 return; 289 } 290 291 /* 292 * validate outer address. 293 */ 294 static int 295 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 296 { 297 struct sockaddr_in *src, *dst; 298 struct in_ifaddr *ia4; 299 300 src = (struct sockaddr_in *)sc->gif_psrc; 301 dst = (struct sockaddr_in *)sc->gif_pdst; 302 303 /* check for address match */ 304 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 305 dst->sin_addr.s_addr != ip->ip_src.s_addr) 306 return 0; 307 308 /* martian filters on outer source - NOT done in ip_input! */ 309 if (IN_MULTICAST(ip->ip_src.s_addr)) 310 return 0; 311 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 312 case 0: case 127: case 255: 313 return 0; 314 } 315 /* reject packets with broadcast on source */ 316 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 317 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 318 continue; 319 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 320 return 0; 321 } 322 323 /* ingress filters on outer source */ 324 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 325 union { 326 struct sockaddr sa; 327 struct sockaddr_in sin; 328 } u; 329 struct rtentry *rt; 330 331 sockaddr_in_init(&u.sin, &ip->ip_src, 0); 332 rt = rtalloc1(&u.sa, 0); 333 if (rt == NULL || rt->rt_ifp != ifp) { 334 #if 0 335 log(LOG_WARNING, "%s: packet from 0x%x dropped " 336 "due to ingress filter\n", if_name(&sc->gif_if), 337 (u_int32_t)ntohl(u.sin.sin_addr.s_addr)); 338 #endif 339 if (rt != NULL) 340 rtfree(rt); 341 return 0; 342 } 343 rtfree(rt); 344 } 345 346 return 32 * 2; 347 } 348 349 #ifdef GIF_ENCAPCHECK 350 /* 351 * we know that we are in IFF_UP, outer address available, and outer family 352 * matched the physical addr family. see gif_encapcheck(). 353 */ 354 int 355 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 356 { 357 struct ip ip; 358 struct gif_softc *sc; 359 struct ifnet *ifp; 360 361 /* sanity check done in caller */ 362 sc = arg; 363 364 m_copydata(m, 0, sizeof(ip), &ip); 365 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 366 367 return gif_validate4(&ip, sc, ifp); 368 } 369 #endif 370 371 int 372 in_gif_attach(struct gif_softc *sc) 373 { 374 #ifndef GIF_ENCAPCHECK 375 struct sockaddr_in mask4; 376 377 memset(&mask4, 0, sizeof(mask4)); 378 mask4.sin_len = sizeof(struct sockaddr_in); 379 mask4.sin_addr.s_addr = ~0; 380 381 if (!sc->gif_psrc || !sc->gif_pdst) 382 return EINVAL; 383 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 384 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 385 (const struct protosw *)&in_gif_protosw, sc); 386 #else 387 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 388 &in_gif_protosw, sc); 389 #endif 390 if (sc->encap_cookie4 == NULL) 391 return EEXIST; 392 return 0; 393 } 394 395 int 396 in_gif_detach(struct gif_softc *sc) 397 { 398 int error; 399 400 error = encap_detach(sc->encap_cookie4); 401 if (error == 0) 402 sc->encap_cookie4 = NULL; 403 404 rtcache_free(&sc->gif_ro); 405 406 return error; 407 } 408