1 /* $NetBSD: in_gif.c,v 1.81 2016/07/06 08:42:34 ozaki-r 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 1.81 2016/07/06 08:42:34 ozaki-r 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 "gif.h" 69 70 #include <net/net_osdep.h> 71 72 static int gif_validate4(const struct ip *, struct gif_softc *, 73 struct ifnet *); 74 75 #if NGIF > 0 76 int ip_gif_ttl = GIF_TTL; 77 #else 78 int ip_gif_ttl = 0; 79 #endif 80 81 static const struct encapsw in_gif_encapsw = { 82 .encapsw4 = { 83 .pr_input = in_gif_input, 84 .pr_ctlinput = NULL, 85 } 86 }; 87 88 int 89 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 90 { 91 struct rtentry *rt; 92 struct gif_softc *sc = ifp->if_softc; 93 struct sockaddr_in *sin_src = satosin(sc->gif_psrc); 94 struct sockaddr_in *sin_dst = satosin(sc->gif_pdst); 95 struct ip iphdr; /* capsule IP header, host byte ordered */ 96 int proto, error; 97 u_int8_t tos; 98 union { 99 struct sockaddr dst; 100 struct sockaddr_in dst4; 101 } u; 102 103 if (sin_src == NULL || sin_dst == NULL || 104 sin_src->sin_family != AF_INET || 105 sin_dst->sin_family != AF_INET) { 106 m_freem(m); 107 return EAFNOSUPPORT; 108 } 109 110 switch (family) { 111 #ifdef INET 112 case AF_INET: 113 { 114 const struct ip *ip; 115 116 proto = IPPROTO_IPV4; 117 if (m->m_len < sizeof(*ip)) { 118 m = m_pullup(m, sizeof(*ip)); 119 if (m == NULL) 120 return ENOBUFS; 121 } 122 ip = mtod(m, const struct ip *); 123 tos = ip->ip_tos; 124 break; 125 } 126 #endif /* INET */ 127 #ifdef INET6 128 case AF_INET6: 129 { 130 const struct ip6_hdr *ip6; 131 proto = IPPROTO_IPV6; 132 if (m->m_len < sizeof(*ip6)) { 133 m = m_pullup(m, sizeof(*ip6)); 134 if (m == NULL) 135 return ENOBUFS; 136 } 137 ip6 = mtod(m, const struct ip6_hdr *); 138 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 139 break; 140 } 141 #endif /* INET6 */ 142 default: 143 #ifdef DEBUG 144 printf("in_gif_output: warning: unknown family %d passed\n", 145 family); 146 #endif 147 m_freem(m); 148 return EAFNOSUPPORT; 149 } 150 151 memset(&iphdr, 0, sizeof(iphdr)); 152 iphdr.ip_src = sin_src->sin_addr; 153 /* bidirectional configured tunnel mode */ 154 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 155 iphdr.ip_dst = sin_dst->sin_addr; 156 else { 157 m_freem(m); 158 return ENETUNREACH; 159 } 160 iphdr.ip_p = proto; 161 /* version will be set in ip_output() */ 162 iphdr.ip_ttl = ip_gif_ttl; 163 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 164 if (ifp->if_flags & IFF_LINK1) 165 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 166 else 167 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 168 169 /* prepend new IP header */ 170 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 171 /* XXX Is m_pullup really necessary after M_PREPEND? */ 172 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 173 m = m_pullup(m, sizeof(struct ip)); 174 if (m == NULL) 175 return ENOBUFS; 176 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 177 178 sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0); 179 if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) { 180 m_freem(m); 181 return ENETUNREACH; 182 } 183 184 /* If the route constitutes infinite encapsulation, punt. */ 185 if (rt->rt_ifp == ifp) { 186 rtcache_free(&sc->gif_ro); 187 m_freem(m); 188 return ENETUNREACH; /*XXX*/ 189 } 190 191 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 192 return (error); 193 } 194 195 void 196 in_gif_input(struct mbuf *m, int off, int proto) 197 { 198 struct ifnet *gifp = NULL; 199 const struct ip *ip; 200 int af; 201 u_int8_t otos; 202 203 ip = mtod(m, const struct ip *); 204 205 gifp = (struct ifnet *)encap_getarg(m); 206 207 if (gifp == NULL || (gifp->if_flags & (IFF_UP|IFF_RUNNING)) 208 != (IFF_UP|IFF_RUNNING)) { 209 m_freem(m); 210 ip_statinc(IP_STAT_NOGIF); 211 return; 212 } 213 #ifndef GIF_ENCAPCHECK 214 struct gif_softc *sc = (struct gif_softc *)gifp->if_softc; 215 /* other CPU do delete_tunnel */ 216 if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { 217 m_freem(m); 218 ip_statinc(IP_STAT_NOGIF); 219 return; 220 } 221 222 struct ifnet *rcvif; 223 struct psref psref; 224 rcvif = m_get_rcvif_psref(m, &psref); 225 if (!gif_validate4(ip, sc, rcvif)) { 226 m_put_rcvif_psref(rcvif, &psref); 227 m_freem(m); 228 ip_statinc(IP_STAT_NOGIF); 229 return; 230 } 231 m_put_rcvif_psref(rcvif, &psref); 232 #endif 233 otos = ip->ip_tos; 234 m_adj(m, off); 235 236 switch (proto) { 237 #ifdef INET 238 case IPPROTO_IPV4: 239 { 240 struct ip *xip; 241 af = AF_INET; 242 if (M_UNWRITABLE(m, sizeof(*xip))) { 243 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 244 return; 245 } 246 xip = mtod(m, struct ip *); 247 if (gifp->if_flags & IFF_LINK1) 248 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 249 else 250 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 251 break; 252 } 253 #endif 254 #ifdef INET6 255 case IPPROTO_IPV6: 256 { 257 struct ip6_hdr *ip6; 258 u_int8_t itos; 259 af = AF_INET6; 260 if (M_UNWRITABLE(m, sizeof(*ip6))) { 261 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 262 return; 263 } 264 ip6 = mtod(m, struct ip6_hdr *); 265 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 266 if (gifp->if_flags & IFF_LINK1) 267 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 268 else 269 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 270 ip6->ip6_flow &= ~htonl(0xff << 20); 271 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 272 break; 273 } 274 #endif /* INET6 */ 275 default: 276 ip_statinc(IP_STAT_NOGIF); 277 m_freem(m); 278 return; 279 } 280 gif_input(m, af, gifp); 281 return; 282 } 283 284 /* 285 * validate outer address. 286 */ 287 static int 288 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 289 { 290 struct sockaddr_in *src, *dst; 291 struct in_ifaddr *ia4; 292 293 src = satosin(sc->gif_psrc); 294 dst = satosin(sc->gif_pdst); 295 296 /* check for address match */ 297 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 298 dst->sin_addr.s_addr != ip->ip_src.s_addr) 299 return 0; 300 301 /* martian filters on outer source - NOT done in ip_input! */ 302 if (IN_MULTICAST(ip->ip_src.s_addr)) 303 return 0; 304 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 305 case 0: case 127: case 255: 306 return 0; 307 } 308 /* reject packets with broadcast on source */ 309 IN_ADDRLIST_READER_FOREACH(ia4) { 310 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 311 continue; 312 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 313 return 0; 314 } 315 316 /* ingress filters on outer source */ 317 if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 318 union { 319 struct sockaddr sa; 320 struct sockaddr_in sin; 321 } u; 322 struct rtentry *rt; 323 324 sockaddr_in_init(&u.sin, &ip->ip_src, 0); 325 rt = rtalloc1(&u.sa, 0); 326 if (rt == NULL || rt->rt_ifp != ifp) { 327 #if 0 328 log(LOG_WARNING, "%s: packet from 0x%x dropped " 329 "due to ingress filter\n", if_name(&sc->gif_if), 330 (u_int32_t)ntohl(u.sin.sin_addr.s_addr)); 331 #endif 332 if (rt != NULL) 333 rtfree(rt); 334 return 0; 335 } 336 rtfree(rt); 337 } 338 339 return 32 * 2; 340 } 341 342 #ifdef GIF_ENCAPCHECK 343 /* 344 * we know that we are in IFF_UP, outer address available, and outer family 345 * matched the physical addr family. see gif_encapcheck(). 346 */ 347 int 348 gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg) 349 { 350 struct ip ip; 351 struct gif_softc *sc; 352 struct ifnet *ifp = NULL; 353 int r; 354 struct psref psref; 355 356 /* sanity check done in caller */ 357 sc = arg; 358 359 m_copydata(m, 0, sizeof(ip), &ip); 360 if ((m->m_flags & M_PKTHDR) != 0) 361 ifp = m_get_rcvif_psref(m, &psref); 362 363 r = gif_validate4(&ip, sc, ifp); 364 365 m_put_rcvif_psref(ifp, &psref); 366 return r; 367 } 368 #endif 369 370 int 371 in_gif_attach(struct gif_softc *sc) 372 { 373 #ifndef GIF_ENCAPCHECK 374 struct sockaddr_in mask4; 375 376 memset(&mask4, 0, sizeof(mask4)); 377 mask4.sin_len = sizeof(struct sockaddr_in); 378 mask4.sin_addr.s_addr = ~0; 379 380 if (!sc->gif_psrc || !sc->gif_pdst) 381 return EINVAL; 382 sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc, 383 (struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4, 384 &in_gif_encapsw, sc); 385 #else 386 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 387 &in_gif_encapsw, sc); 388 #endif 389 if (sc->encap_cookie4 == NULL) 390 return EEXIST; 391 return 0; 392 } 393 394 int 395 in_gif_detach(struct gif_softc *sc) 396 { 397 int error; 398 399 error = in_gif_pause(sc); 400 401 rtcache_free(&sc->gif_ro); 402 403 return error; 404 } 405 406 int 407 in_gif_pause(struct gif_softc *sc) 408 { 409 int error; 410 411 error = encap_detach(sc->encap_cookie4); 412 if (error == 0) 413 sc->encap_cookie4 = NULL; 414 415 return error; 416 } 417