in_gif.c revision 1.52
1 /* $NetBSD: in_gif.c,v 1.52 2006/12/09 05:33:04 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 1.52 2006/12/09 05:33:04 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 gif_softc *sc = (struct gif_softc*)ifp; 94 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 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; 100 101 if (sin_src == NULL || sin_dst == NULL || 102 sin_src->sin_family != AF_INET || 103 sin_dst->sin_family != AF_INET) { 104 m_freem(m); 105 return EAFNOSUPPORT; 106 } 107 108 switch (family) { 109 #ifdef INET 110 case AF_INET: 111 { 112 const struct ip *ip; 113 114 proto = IPPROTO_IPV4; 115 if (m->m_len < sizeof(*ip)) { 116 m = m_pullup(m, sizeof(*ip)); 117 if (m == NULL) 118 return ENOBUFS; 119 } 120 ip = mtod(m, const struct ip *); 121 tos = ip->ip_tos; 122 break; 123 } 124 #endif /* INET */ 125 #ifdef INET6 126 case AF_INET6: 127 { 128 const struct ip6_hdr *ip6; 129 proto = IPPROTO_IPV6; 130 if (m->m_len < sizeof(*ip6)) { 131 m = m_pullup(m, sizeof(*ip6)); 132 if (!m) 133 return ENOBUFS; 134 } 135 ip6 = mtod(m, const struct ip6_hdr *); 136 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 137 break; 138 } 139 #endif /* INET6 */ 140 #ifdef ISO 141 case AF_ISO: 142 proto = IPPROTO_EON; 143 tos = 0; 144 break; 145 #endif 146 default: 147 #ifdef DEBUG 148 printf("in_gif_output: warning: unknown family %d passed\n", 149 family); 150 #endif 151 m_freem(m); 152 return EAFNOSUPPORT; 153 } 154 155 bzero(&iphdr, sizeof(iphdr)); 156 iphdr.ip_src = sin_src->sin_addr; 157 /* bidirectional configured tunnel mode */ 158 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 159 iphdr.ip_dst = sin_dst->sin_addr; 160 else { 161 m_freem(m); 162 return ENETUNREACH; 163 } 164 iphdr.ip_p = proto; 165 /* version will be set in ip_output() */ 166 iphdr.ip_ttl = ip_gif_ttl; 167 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 168 if (ifp->if_flags & IFF_LINK1) 169 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 170 else 171 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 172 173 /* prepend new IP header */ 174 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 175 /* XXX Is m_pullup really necessary after M_PREPEND? */ 176 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 177 m = m_pullup(m, sizeof(struct ip)); 178 if (m == NULL) 179 return ENOBUFS; 180 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 181 182 if (dst->sin_family != sin_dst->sin_family || 183 !in_hosteq(dst->sin_addr, sin_dst->sin_addr)) { 184 /* cache route doesn't match */ 185 bzero(dst, sizeof(*dst)); 186 dst->sin_family = sin_dst->sin_family; 187 dst->sin_len = sizeof(struct sockaddr_in); 188 dst->sin_addr = sin_dst->sin_addr; 189 if (sc->gif_ro.ro_rt != NULL) 190 rtflush(&sc->gif_ro); 191 } 192 193 if (sc->gif_ro.ro_rt == NULL) { 194 rtalloc(&sc->gif_ro); 195 if (sc->gif_ro.ro_rt == NULL) { 196 m_freem(m); 197 return ENETUNREACH; 198 } 199 200 /* if it constitutes infinite encapsulation, punt. */ 201 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 202 m_freem(m); 203 return ENETUNREACH; /*XXX*/ 204 } 205 } 206 207 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 208 return (error); 209 } 210 211 void 212 in_gif_input(struct mbuf *m, ...) 213 { 214 int off, proto; 215 struct ifnet *gifp = NULL; 216 const struct ip *ip; 217 va_list ap; 218 int af; 219 u_int8_t otos; 220 221 va_start(ap, m); 222 off = va_arg(ap, int); 223 proto = va_arg(ap, int); 224 va_end(ap); 225 226 ip = mtod(m, const struct ip *); 227 228 gifp = (struct ifnet *)encap_getarg(m); 229 230 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 231 m_freem(m); 232 ipstat.ips_nogif++; 233 return; 234 } 235 #ifndef GIF_ENCAPCHECK 236 if (!gif_validate4(ip, (struct gif_softc *)gifp, m->m_pkthdr.rcvif)) { 237 m_freem(m); 238 ipstat.ips_nogif++; 239 return; 240 } 241 #endif 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 *xip; 251 af = AF_INET; 252 if (M_UNWRITABLE(m, sizeof(*xip))) { 253 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 254 return; 255 } 256 xip = mtod(m, struct ip *); 257 if (gifp->if_flags & IFF_LINK1) 258 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 259 else 260 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 261 break; 262 } 263 #endif 264 #ifdef INET6 265 case IPPROTO_IPV6: 266 { 267 struct ip6_hdr *ip6; 268 u_int8_t itos; 269 af = AF_INET6; 270 if (M_UNWRITABLE(m, sizeof(*ip6))) { 271 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 272 return; 273 } 274 ip6 = mtod(m, struct ip6_hdr *); 275 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 276 if (gifp->if_flags & IFF_LINK1) 277 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 278 else 279 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 280 ip6->ip6_flow &= ~htonl(0xff << 20); 281 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 282 break; 283 } 284 #endif /* INET6 */ 285 #ifdef ISO 286 case IPPROTO_EON: 287 af = AF_ISO; 288 break; 289 #endif 290 default: 291 ipstat.ips_nogif++; 292 m_freem(m); 293 return; 294 } 295 gif_input(m, af, gifp); 296 return; 297 } 298 299 /* 300 * validate outer address. 301 */ 302 static int 303 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 304 { 305 struct sockaddr_in *src, *dst; 306 struct in_ifaddr *ia4; 307 308 src = (struct sockaddr_in *)sc->gif_psrc; 309 dst = (struct sockaddr_in *)sc->gif_pdst; 310 311 /* check for address match */ 312 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 313 dst->sin_addr.s_addr != ip->ip_src.s_addr) 314 return 0; 315 316 /* martian filters on outer source - NOT done in ip_input! */ 317 if (IN_MULTICAST(ip->ip_src.s_addr)) 318 return 0; 319 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 320 case 0: case 127: case 255: 321 return 0; 322 } 323 /* reject packets with broadcast on source */ 324 TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) { 325 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 326 continue; 327 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 328 return 0; 329 } 330 331 /* ingress filters on outer source */ 332 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 333 struct sockaddr_in sin; 334 struct rtentry *rt; 335 336 bzero(&sin, sizeof(sin)); 337 sin.sin_family = AF_INET; 338 sin.sin_len = sizeof(struct sockaddr_in); 339 sin.sin_addr = ip->ip_src; 340 rt = rtalloc1((struct sockaddr *)&sin, 0); 341 if (!rt || rt->rt_ifp != ifp) { 342 #if 0 343 log(LOG_WARNING, "%s: packet from 0x%x dropped " 344 "due to ingress filter\n", if_name(&sc->gif_if), 345 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 346 #endif 347 if (rt) 348 rtfree(rt); 349 return 0; 350 } 351 rtfree(rt); 352 } 353 354 return 32 * 2; 355 } 356 357 #ifdef GIF_ENCAPCHECK 358 /* 359 * we know that we are in IFF_UP, outer address available, and outer family 360 * matched the physical addr family. see gif_encapcheck(). 361 */ 362 int 363 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 364 { 365 struct ip ip; 366 struct gif_softc *sc; 367 struct ifnet *ifp; 368 369 /* sanity check done in caller */ 370 sc = (struct gif_softc *)arg; 371 372 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 373 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 374 375 return gif_validate4(&ip, sc, ifp); 376 } 377 #endif 378 379 int 380 in_gif_attach(struct gif_softc *sc) 381 { 382 #ifndef GIF_ENCAPCHECK 383 struct sockaddr_in mask4; 384 385 bzero(&mask4, sizeof(mask4)); 386 mask4.sin_len = sizeof(struct sockaddr_in); 387 mask4.sin_addr.s_addr = ~0; 388 389 if (!sc->gif_psrc || !sc->gif_pdst) 390 return EINVAL; 391 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 392 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 393 (const struct protosw *)&in_gif_protosw, sc); 394 #else 395 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 396 &in_gif_protosw, sc); 397 #endif 398 if (sc->encap_cookie4 == NULL) 399 return EEXIST; 400 return 0; 401 } 402 403 int 404 in_gif_detach(struct gif_softc *sc) 405 { 406 int error; 407 408 error = encap_detach(sc->encap_cookie4); 409 if (error == 0) 410 sc->encap_cookie4 = NULL; 411 412 if (sc->gif_ro.ro_rt != NULL) 413 rtflush(&sc->gif_ro); 414 415 return error; 416 } 417
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