in_gif.c revision 1.86
1 /* $NetBSD: in_gif.c,v 1.86 2016/12/14 11:19:15 knakahara 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 1.86 2016/12/14 11:19:15 knakahara Exp $"); 35 36 #ifdef _KERNEL_OPT 37 #include "opt_inet.h" 38 #endif 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/mbuf.h> 45 #include <sys/errno.h> 46 #include <sys/ioctl.h> 47 #include <sys/syslog.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 <net/net_osdep.h> 69 70 static int gif_validate4(const struct ip *, struct gif_softc *, 71 struct ifnet *); 72 73 int ip_gif_ttl = GIF_TTL; 74 75 static const struct encapsw in_gif_encapsw = { 76 .encapsw4 = { 77 .pr_input = in_gif_input, 78 .pr_ctlinput = NULL, 79 } 80 }; 81 82 int 83 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 84 { 85 struct rtentry *rt; 86 struct route *ro; 87 struct gif_softc *sc = ifp->if_softc; 88 struct sockaddr_in *sin_src = satosin(sc->gif_psrc); 89 struct sockaddr_in *sin_dst = satosin(sc->gif_pdst); 90 struct ip iphdr; /* capsule IP header, host byte ordered */ 91 int proto, error; 92 u_int8_t tos; 93 union { 94 struct sockaddr dst; 95 struct sockaddr_in dst4; 96 } u; 97 98 if (sin_src == NULL || sin_dst == NULL || 99 sin_src->sin_family != AF_INET || 100 sin_dst->sin_family != AF_INET) { 101 m_freem(m); 102 return EAFNOSUPPORT; 103 } 104 105 switch (family) { 106 #ifdef INET 107 case AF_INET: 108 { 109 const struct ip *ip; 110 111 proto = IPPROTO_IPV4; 112 if (m->m_len < sizeof(*ip)) { 113 m = m_pullup(m, sizeof(*ip)); 114 if (m == NULL) 115 return ENOBUFS; 116 } 117 ip = mtod(m, const struct ip *); 118 tos = ip->ip_tos; 119 break; 120 } 121 #endif /* INET */ 122 #ifdef INET6 123 case AF_INET6: 124 { 125 const struct ip6_hdr *ip6; 126 proto = IPPROTO_IPV6; 127 if (m->m_len < sizeof(*ip6)) { 128 m = m_pullup(m, sizeof(*ip6)); 129 if (m == NULL) 130 return ENOBUFS; 131 } 132 ip6 = mtod(m, const struct ip6_hdr *); 133 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 134 break; 135 } 136 #endif /* INET6 */ 137 default: 138 #ifdef DEBUG 139 printf("in_gif_output: warning: unknown family %d passed\n", 140 family); 141 #endif 142 m_freem(m); 143 return EAFNOSUPPORT; 144 } 145 146 memset(&iphdr, 0, sizeof(iphdr)); 147 iphdr.ip_src = sin_src->sin_addr; 148 /* bidirectional configured tunnel mode */ 149 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 150 iphdr.ip_dst = sin_dst->sin_addr; 151 else { 152 m_freem(m); 153 return ENETUNREACH; 154 } 155 iphdr.ip_p = proto; 156 /* version will be set in ip_output() */ 157 iphdr.ip_ttl = ip_gif_ttl; 158 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 159 if (ifp->if_flags & IFF_LINK1) 160 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 161 else 162 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 163 164 /* prepend new IP header */ 165 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 166 /* XXX Is m_pullup really necessary after M_PREPEND? */ 167 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 168 m = m_pullup(m, sizeof(struct ip)); 169 if (m == NULL) 170 return ENOBUFS; 171 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 172 173 sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0); 174 175 ro = percpu_getref(sc->gif_ro_percpu); 176 if ((rt = rtcache_lookup(ro, &u.dst)) == NULL) { 177 percpu_putref(sc->gif_ro_percpu); 178 m_freem(m); 179 return ENETUNREACH; 180 } 181 182 /* If the route constitutes infinite encapsulation, punt. */ 183 if (rt->rt_ifp == ifp) { 184 rtcache_unref(rt, ro); 185 rtcache_free(ro); 186 percpu_putref(sc->gif_ro_percpu); 187 m_freem(m); 188 return ENETUNREACH; /*XXX*/ 189 } 190 rtcache_unref(rt, ro); 191 192 error = ip_output(m, NULL, ro, 0, NULL, NULL); 193 percpu_putref(sc->gif_ro_percpu); 194 return (error); 195 } 196 197 void 198 in_gif_input(struct mbuf *m, int off, int proto) 199 { 200 struct ifnet *gifp = NULL; 201 const struct ip *ip; 202 int af; 203 u_int8_t otos; 204 205 ip = mtod(m, const struct ip *); 206 207 gifp = (struct ifnet *)encap_getarg(m); 208 209 if (gifp == NULL || (gifp->if_flags & (IFF_UP|IFF_RUNNING)) 210 != (IFF_UP|IFF_RUNNING)) { 211 m_freem(m); 212 ip_statinc(IP_STAT_NOGIF); 213 return; 214 } 215 #ifndef GIF_ENCAPCHECK 216 struct gif_softc *sc = (struct gif_softc *)gifp->if_softc; 217 /* other CPU do delete_tunnel */ 218 if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { 219 m_freem(m); 220 ip_statinc(IP_STAT_NOGIF); 221 return; 222 } 223 224 struct ifnet *rcvif; 225 struct psref psref; 226 rcvif = m_get_rcvif_psref(m, &psref); 227 if (!gif_validate4(ip, sc, rcvif)) { 228 m_put_rcvif_psref(rcvif, &psref); 229 m_freem(m); 230 ip_statinc(IP_STAT_NOGIF); 231 return; 232 } 233 m_put_rcvif_psref(rcvif, &psref); 234 #endif 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 default: 278 ip_statinc(IP_STAT_NOGIF); 279 m_freem(m); 280 return; 281 } 282 gif_input(m, af, gifp); 283 return; 284 } 285 286 /* 287 * validate outer address. 288 */ 289 static int 290 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 291 { 292 struct sockaddr_in *src, *dst; 293 struct in_ifaddr *ia4; 294 int s; 295 296 src = satosin(sc->gif_psrc); 297 dst = satosin(sc->gif_pdst); 298 299 /* check for address match */ 300 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 301 dst->sin_addr.s_addr != ip->ip_src.s_addr) 302 return 0; 303 304 /* martian filters on outer source - NOT done in ip_input! */ 305 if (IN_MULTICAST(ip->ip_src.s_addr)) 306 return 0; 307 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 308 case 0: case 127: case 255: 309 return 0; 310 } 311 /* reject packets with broadcast on source */ 312 s = pserialize_read_enter(); 313 IN_ADDRLIST_READER_FOREACH(ia4) { 314 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 315 continue; 316 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 317 pserialize_read_exit(s); 318 return 0; 319 } 320 } 321 pserialize_read_exit(s); 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 rt_unref(rt); 341 return 0; 342 } 343 rt_unref(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 = NULL; 360 int r; 361 struct psref psref; 362 363 /* sanity check done in caller */ 364 sc = arg; 365 366 m_copydata(m, 0, sizeof(ip), &ip); 367 if ((m->m_flags & M_PKTHDR) != 0) 368 ifp = m_get_rcvif_psref(m, &psref); 369 370 r = gif_validate4(&ip, sc, ifp); 371 372 m_put_rcvif_psref(ifp, &psref); 373 return r; 374 } 375 #endif 376 377 int 378 in_gif_attach(struct gif_softc *sc) 379 { 380 #ifndef GIF_ENCAPCHECK 381 struct sockaddr_in mask4; 382 383 memset(&mask4, 0, sizeof(mask4)); 384 mask4.sin_len = sizeof(struct sockaddr_in); 385 mask4.sin_addr.s_addr = ~0; 386 387 if (!sc->gif_psrc || !sc->gif_pdst) 388 return EINVAL; 389 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 390 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 391 &in_gif_encapsw, sc); 392 #else 393 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 394 &in_gif_encapsw, sc); 395 #endif 396 if (sc->encap_cookie4 == NULL) 397 return EEXIST; 398 return 0; 399 } 400 401 int 402 in_gif_detach(struct gif_softc *sc) 403 { 404 int error; 405 406 error = in_gif_pause(sc); 407 408 percpu_foreach(sc->gif_ro_percpu, gif_rtcache_free_pc, NULL); 409 410 return error; 411 } 412 413 int 414 in_gif_pause(struct gif_softc *sc) 415 { 416 int error; 417 418 error = encap_detach(sc->encap_cookie4); 419 if (error == 0) 420 sc->encap_cookie4 = NULL; 421 422 return error; 423 } 424
Indexes created Mon Sep 29 03:10:08 GMT 2025