in_gif.c revision 1.90
1 /* $NetBSD: in_gif.c,v 1.90 2017/11/27 05:02:22 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 1.90 2017/11/27 05:02:22 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_variant *, 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 static int 83 in_gif_output(struct gif_variant *var, int family, struct mbuf *m) 84 { 85 struct rtentry *rt; 86 struct route *ro; 87 struct gif_ro *gro; 88 struct gif_softc *sc; 89 struct sockaddr_in *sin_src; 90 struct sockaddr_in *sin_dst; 91 struct ifnet *ifp; 92 struct ip iphdr; /* capsule IP header, host byte ordered */ 93 int proto, error; 94 u_int8_t tos; 95 96 KASSERT(gif_heldref_variant(var)); 97 98 sin_src = satosin(var->gv_psrc); 99 sin_dst = satosin(var->gv_pdst); 100 ifp = &var->gv_softc->gif_if; 101 102 if (sin_src == NULL || sin_dst == NULL || 103 sin_src->sin_family != AF_INET || 104 sin_dst->sin_family != AF_INET) { 105 m_freem(m); 106 return EAFNOSUPPORT; 107 } 108 109 switch (family) { 110 #ifdef INET 111 case AF_INET: 112 { 113 const struct ip *ip; 114 115 proto = IPPROTO_IPV4; 116 if (m->m_len < sizeof(*ip)) { 117 m = m_pullup(m, sizeof(*ip)); 118 if (m == NULL) 119 return ENOBUFS; 120 } 121 ip = mtod(m, const struct ip *); 122 tos = ip->ip_tos; 123 break; 124 } 125 #endif /* INET */ 126 #ifdef INET6 127 case AF_INET6: 128 { 129 const struct ip6_hdr *ip6; 130 proto = IPPROTO_IPV6; 131 if (m->m_len < sizeof(*ip6)) { 132 m = m_pullup(m, sizeof(*ip6)); 133 if (m == NULL) 134 return ENOBUFS; 135 } 136 ip6 = mtod(m, const struct ip6_hdr *); 137 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 138 break; 139 } 140 #endif /* INET6 */ 141 default: 142 #ifdef DEBUG 143 printf("in_gif_output: warning: unknown family %d passed\n", 144 family); 145 #endif 146 m_freem(m); 147 return EAFNOSUPPORT; 148 } 149 150 memset(&iphdr, 0, sizeof(iphdr)); 151 iphdr.ip_src = sin_src->sin_addr; 152 /* bidirectional configured tunnel mode */ 153 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 154 iphdr.ip_dst = sin_dst->sin_addr; 155 else { 156 m_freem(m); 157 return ENETUNREACH; 158 } 159 iphdr.ip_p = proto; 160 /* version will be set in ip_output() */ 161 iphdr.ip_ttl = ip_gif_ttl; 162 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 163 if (ifp->if_flags & IFF_LINK1) 164 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos); 165 else 166 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos); 167 168 /* prepend new IP header */ 169 M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); 170 /* XXX Is m_pullup really necessary after M_PREPEND? */ 171 if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip))) 172 m = m_pullup(m, sizeof(struct ip)); 173 if (m == NULL) 174 return ENOBUFS; 175 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 176 177 sc = var->gv_softc; 178 gro = percpu_getref(sc->gif_ro_percpu); 179 mutex_enter(&gro->gr_lock); 180 ro = &gro->gr_ro; 181 if ((rt = rtcache_lookup(ro, var->gv_pdst)) == NULL) { 182 mutex_exit(&gro->gr_lock); 183 percpu_putref(sc->gif_ro_percpu); 184 m_freem(m); 185 return ENETUNREACH; 186 } 187 188 /* If the route constitutes infinite encapsulation, punt. */ 189 if (rt->rt_ifp == ifp) { 190 rtcache_unref(rt, ro); 191 rtcache_free(ro); 192 mutex_exit(&gro->gr_lock); 193 percpu_putref(sc->gif_ro_percpu); 194 m_freem(m); 195 return ENETUNREACH; /*XXX*/ 196 } 197 rtcache_unref(rt, ro); 198 199 error = ip_output(m, NULL, ro, 0, NULL, NULL); 200 mutex_exit(&gro->gr_lock); 201 percpu_putref(sc->gif_ro_percpu); 202 return (error); 203 } 204 205 void 206 in_gif_input(struct mbuf *m, int off, int proto, void *eparg) 207 { 208 struct gif_softc *sc = eparg; 209 struct ifnet *gifp = &sc->gif_if; 210 const struct ip *ip; 211 int af; 212 u_int8_t otos; 213 214 KASSERT(sc != NULL); 215 216 ip = mtod(m, const struct ip *); 217 218 gifp = &sc->gif_if; 219 if ((gifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) { 220 m_freem(m); 221 ip_statinc(IP_STAT_NOGIF); 222 return; 223 } 224 #ifndef GIF_ENCAPCHECK 225 struct psref psref_var; 226 struct gif_variant *var = gif_getref_variant(sc, &psref_var); 227 /* other CPU do delete_tunnel */ 228 if (var->gv_psrc == NULL || var->gv_pdst == NULL) { 229 gif_putref_variant(var, &psref_var); 230 m_freem(m); 231 ip_statinc(IP_STAT_NOGIF); 232 return; 233 } 234 235 struct ifnet *rcvif; 236 struct psref psref_rcvif; 237 rcvif = m_get_rcvif_psref(m, &psref_rcvif); 238 if (!gif_validate4(ip, var, rcvif)) { 239 m_put_rcvif_psref(rcvif, &psref_rcvif); 240 gif_putref_variant(var, &psref_var); 241 m_freem(m); 242 ip_statinc(IP_STAT_NOGIF); 243 return; 244 } 245 m_put_rcvif_psref(rcvif, &psref_rcvif); 246 gif_putref_variant(var, &psref_var); 247 #endif 248 otos = ip->ip_tos; 249 m_adj(m, off); 250 251 switch (proto) { 252 #ifdef INET 253 case IPPROTO_IPV4: 254 { 255 struct ip *xip; 256 af = AF_INET; 257 if (M_UNWRITABLE(m, sizeof(*xip))) { 258 if ((m = m_pullup(m, sizeof(*xip))) == NULL) 259 return; 260 } 261 xip = mtod(m, struct ip *); 262 if (gifp->if_flags & IFF_LINK1) 263 ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos); 264 else 265 ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos); 266 break; 267 } 268 #endif 269 #ifdef INET6 270 case IPPROTO_IPV6: 271 { 272 struct ip6_hdr *ip6; 273 u_int8_t itos; 274 af = AF_INET6; 275 if (M_UNWRITABLE(m, sizeof(*ip6))) { 276 if ((m = m_pullup(m, sizeof(*ip6))) == NULL) 277 return; 278 } 279 ip6 = mtod(m, struct ip6_hdr *); 280 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 281 if (gifp->if_flags & IFF_LINK1) 282 ip_ecn_egress(ECN_ALLOWED, &otos, &itos); 283 else 284 ip_ecn_egress(ECN_NOCARE, &otos, &itos); 285 ip6->ip6_flow &= ~htonl(0xff << 20); 286 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 287 break; 288 } 289 #endif /* INET6 */ 290 default: 291 ip_statinc(IP_STAT_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_variant *var, struct ifnet *ifp) 304 { 305 struct sockaddr_in *src, *dst; 306 struct in_ifaddr *ia4; 307 int s; 308 309 src = satosin(var->gv_psrc); 310 dst = satosin(var->gv_pdst); 311 312 /* check for address match */ 313 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 314 dst->sin_addr.s_addr != ip->ip_src.s_addr) 315 return 0; 316 317 /* martian filters on outer source - NOT done in ip_input! */ 318 if (IN_MULTICAST(ip->ip_src.s_addr)) 319 return 0; 320 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 321 case 0: case 127: case 255: 322 return 0; 323 } 324 /* reject packets with broadcast on source */ 325 s = pserialize_read_enter(); 326 IN_ADDRLIST_READER_FOREACH(ia4) { 327 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 328 continue; 329 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 330 pserialize_read_exit(s); 331 return 0; 332 } 333 } 334 pserialize_read_exit(s); 335 336 /* ingress filters on outer source */ 337 if ((var->gv_softc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) { 338 union { 339 struct sockaddr sa; 340 struct sockaddr_in sin; 341 } u; 342 struct rtentry *rt; 343 344 sockaddr_in_init(&u.sin, &ip->ip_src, 0); 345 rt = rtalloc1(&u.sa, 0); 346 if (rt == NULL || rt->rt_ifp != ifp) { 347 #if 0 348 log(LOG_WARNING, "%s: packet from 0x%x dropped " 349 "due to ingress filter\n", 350 if_name(&var->gv_softc->gif_if), 351 (u_int32_t)ntohl(u.sin.sin_addr.s_addr)); 352 #endif 353 if (rt != NULL) 354 rt_unref(rt); 355 return 0; 356 } 357 rt_unref(rt); 358 } 359 360 return 32 * 2; 361 } 362 363 #ifdef GIF_ENCAPCHECK 364 /* 365 * we know that we are in IFF_UP, outer address available, and outer family 366 * matched the physical addr family. see gif_encapcheck(). 367 */ 368 int 369 gif_encapcheck4(struct mbuf *m, int off, int proto, struct gif_variant *var) 370 { 371 struct ip ip; 372 373 struct ifnet *ifp = NULL; 374 int r; 375 struct psref psref; 376 377 m_copydata(m, 0, sizeof(ip), &ip); 378 if ((m->m_flags & M_PKTHDR) != 0) 379 ifp = m_get_rcvif_psref(m, &psref); 380 381 r = gif_validate4(&ip, var, ifp); 382 383 m_put_rcvif_psref(ifp, &psref); 384 return r; 385 } 386 #endif 387 388 int 389 in_gif_attach(struct gif_variant *var) 390 { 391 #ifndef GIF_ENCAPCHECK 392 struct sockaddr_in mask4; 393 394 memset(&mask4, 0, sizeof(mask4)); 395 mask4.sin_len = sizeof(struct sockaddr_in); 396 mask4.sin_addr.s_addr = ~0; 397 398 if (!var->gv_psrc || !var->gv_pdst) 399 return EINVAL; 400 var->gv_encap_cookie4 = encap_attach(AF_INET, -1, var->gv_psrc, 401 (struct sockaddr *)&mask4, var->gv_pdst, (struct sockaddr *)&mask4, 402 &in_gif_encapsw, var->gv_softc); 403 #else 404 var->gv_encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 405 &in_gif_encapsw, var->gv_softc); 406 #endif 407 if (var->gv_encap_cookie4 == NULL) 408 return EEXIST; 409 410 var->gv_output = in_gif_output; 411 return 0; 412 } 413 414 int 415 in_gif_detach(struct gif_variant *var) 416 { 417 int error; 418 struct gif_softc *sc = var->gv_softc; 419 420 error = encap_detach(var->gv_encap_cookie4); 421 if (error == 0) 422 var->gv_encap_cookie4 = NULL; 423 424 percpu_foreach(sc->gif_ro_percpu, gif_rtcache_free_pc, NULL); 425 426 return error; 427 } 428
Indexes created Sun Sep 28 16:09:52 GMT 2025