1 /* $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $ */ 2 3 /*- 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_mrouting.h" 36 #include "opt_inet.h" 37 #include "opt_inet6.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/kernel.h> 46 #include <sys/sysctl.h> 47 #include <sys/protosw.h> 48 #include <sys/malloc.h> 49 50 #include <net/if.h> 51 #include <net/if_var.h> 52 #include <net/route.h> 53 #include <net/vnet.h> 54 55 #include <netinet/in.h> 56 #include <netinet/in_systm.h> 57 #include <netinet/ip.h> 58 #include <netinet/ip_var.h> 59 #include <netinet/in_gif.h> 60 #include <netinet/in_var.h> 61 #include <netinet/ip_encap.h> 62 #include <netinet/ip_ecn.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #endif 67 68 #ifdef MROUTING 69 #include <netinet/ip_mroute.h> 70 #endif /* MROUTING */ 71 72 #include <net/if_gif.h> 73 74 static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77 extern struct domain inetdomain; 78 struct protosw in_gif_protosw = { 79 .pr_type = SOCK_RAW, 80 .pr_domain = &inetdomain, 81 .pr_protocol = 0/* IPPROTO_IPV[46] */, 82 .pr_flags = PR_ATOMIC|PR_ADDR, 83 .pr_input = in_gif_input, 84 .pr_output = (pr_output_t *)rip_output, 85 .pr_ctloutput = rip_ctloutput, 86 .pr_usrreqs = &rip_usrreqs 87 }; 88 89 VNET_DEFINE(int, ip_gif_ttl) = GIF_TTL; 90 #define V_ip_gif_ttl VNET(ip_gif_ttl) 91 SYSCTL_VNET_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW, 92 &VNET_NAME(ip_gif_ttl), 0, ""); 93 94 int 95 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 96 { 97 struct gif_softc *sc = ifp->if_softc; 98 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 99 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 100 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 101 struct ip iphdr; /* capsule IP header, host byte ordered */ 102 struct etherip_header eiphdr; 103 int error, len, proto; 104 u_int8_t tos; 105 106 GIF_LOCK_ASSERT(sc); 107 108 if (sin_src == NULL || sin_dst == NULL || 109 sin_src->sin_family != AF_INET || 110 sin_dst->sin_family != AF_INET) { 111 m_freem(m); 112 return EAFNOSUPPORT; 113 } 114 115 switch (family) { 116 #ifdef INET 117 case AF_INET: 118 { 119 struct ip *ip; 120 121 proto = IPPROTO_IPV4; 122 if (m->m_len < sizeof(*ip)) { 123 m = m_pullup(m, sizeof(*ip)); 124 if (!m) 125 return ENOBUFS; 126 } 127 ip = mtod(m, struct ip *); 128 tos = ip->ip_tos; 129 break; 130 } 131 #endif /* INET */ 132 #ifdef INET6 133 case AF_INET6: 134 { 135 struct ip6_hdr *ip6; 136 proto = IPPROTO_IPV6; 137 if (m->m_len < sizeof(*ip6)) { 138 m = m_pullup(m, sizeof(*ip6)); 139 if (!m) 140 return ENOBUFS; 141 } 142 ip6 = mtod(m, struct ip6_hdr *); 143 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 144 break; 145 } 146 #endif /* INET6 */ 147 case AF_LINK: 148 proto = IPPROTO_ETHERIP; 149 150 /* 151 * GIF_SEND_REVETHIP (disabled by default) intentionally 152 * sends an EtherIP packet with revered version field in 153 * the header. This is a knob for backward compatibility 154 * with FreeBSD 7.2R or prior. 155 */ 156 if ((sc->gif_options & GIF_SEND_REVETHIP)) { 157 eiphdr.eip_ver = 0; 158 eiphdr.eip_resvl = ETHERIP_VERSION; 159 eiphdr.eip_resvh = 0; 160 } else { 161 eiphdr.eip_ver = ETHERIP_VERSION; 162 eiphdr.eip_resvl = 0; 163 eiphdr.eip_resvh = 0; 164 } 165 /* prepend Ethernet-in-IP header */ 166 M_PREPEND(m, sizeof(struct etherip_header), M_NOWAIT); 167 if (m && m->m_len < sizeof(struct etherip_header)) 168 m = m_pullup(m, sizeof(struct etherip_header)); 169 if (m == NULL) 170 return ENOBUFS; 171 bcopy(&eiphdr, mtod(m, struct etherip_header *), 172 sizeof(struct etherip_header)); 173 tos = 0; 174 break; 175 176 default: 177 #ifdef DEBUG 178 printf("in_gif_output: warning: unknown family %d passed\n", 179 family); 180 #endif 181 m_freem(m); 182 return EAFNOSUPPORT; 183 } 184 185 bzero(&iphdr, sizeof(iphdr)); 186 iphdr.ip_src = sin_src->sin_addr; 187 /* bidirectional configured tunnel mode */ 188 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 189 iphdr.ip_dst = sin_dst->sin_addr; 190 else { 191 m_freem(m); 192 return ENETUNREACH; 193 } 194 iphdr.ip_p = proto; 195 /* version will be set in ip_output() */ 196 iphdr.ip_ttl = V_ip_gif_ttl; 197 iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip)); 198 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 199 &iphdr.ip_tos, &tos); 200 201 /* prepend new IP header */ 202 len = sizeof(struct ip); 203 #ifndef __NO_STRICT_ALIGNMENT 204 if (family == AF_LINK) 205 len += ETHERIP_ALIGN; 206 #endif 207 M_PREPEND(m, len, M_NOWAIT); 208 if (m != NULL && m->m_len < len) 209 m = m_pullup(m, len); 210 if (m == NULL) { 211 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 212 return ENOBUFS; 213 } 214 #ifndef __NO_STRICT_ALIGNMENT 215 if (family == AF_LINK) { 216 len = mtod(m, vm_offset_t) & 3; 217 KASSERT(len == 0 || len == ETHERIP_ALIGN, 218 ("in_gif_output: unexpected misalignment")); 219 m->m_data += len; 220 m->m_len -= ETHERIP_ALIGN; 221 } 222 #endif 223 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 224 225 M_SETFIB(m, sc->gif_fibnum); 226 227 if (dst->sin_family != sin_dst->sin_family || 228 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 229 /* cache route doesn't match */ 230 bzero(dst, sizeof(*dst)); 231 dst->sin_family = sin_dst->sin_family; 232 dst->sin_len = sizeof(struct sockaddr_in); 233 dst->sin_addr = sin_dst->sin_addr; 234 if (sc->gif_ro.ro_rt) { 235 RTFREE(sc->gif_ro.ro_rt); 236 sc->gif_ro.ro_rt = NULL; 237 } 238 #if 0 239 GIF2IFP(sc)->if_mtu = GIF_MTU; 240 #endif 241 } 242 243 if (sc->gif_ro.ro_rt == NULL) { 244 in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum); 245 if (sc->gif_ro.ro_rt == NULL) { 246 m_freem(m); 247 return ENETUNREACH; 248 } 249 250 /* if it constitutes infinite encapsulation, punt. */ 251 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 252 m_freem(m); 253 return ENETUNREACH; /* XXX */ 254 } 255 #if 0 256 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 257 - sizeof(struct ip); 258 #endif 259 } 260 261 m->m_flags &= ~(M_BCAST|M_MCAST); 262 error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL); 263 264 if (!(GIF2IFP(sc)->if_flags & IFF_LINK0) && 265 sc->gif_ro.ro_rt != NULL) { 266 RTFREE(sc->gif_ro.ro_rt); 267 sc->gif_ro.ro_rt = NULL; 268 } 269 270 return (error); 271 } 272 273 int 274 in_gif_input(struct mbuf **mp, int *offp, int proto) 275 { 276 struct mbuf *m; 277 struct ifnet *gifp = NULL; 278 struct gif_softc *sc; 279 struct ip *ip; 280 int af; 281 int off; 282 u_int8_t otos; 283 284 m = *mp; 285 ip = mtod(m, struct ip *); 286 off = *offp; 287 *mp = NULL; 288 289 sc = (struct gif_softc *)encap_getarg(m); 290 if (sc == NULL) { 291 m_freem(m); 292 KMOD_IPSTAT_INC(ips_nogif); 293 return (IPPROTO_DONE); 294 } 295 296 gifp = GIF2IFP(sc); 297 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 298 m_freem(m); 299 KMOD_IPSTAT_INC(ips_nogif); 300 return (IPPROTO_DONE); 301 } 302 303 otos = ip->ip_tos; 304 m_adj(m, off); 305 306 switch (proto) { 307 #ifdef INET 308 case IPPROTO_IPV4: 309 { 310 struct ip *ip; 311 af = AF_INET; 312 if (m->m_len < sizeof(*ip)) { 313 m = m_pullup(m, sizeof(*ip)); 314 if (!m) 315 return (IPPROTO_DONE); 316 } 317 ip = mtod(m, struct ip *); 318 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 319 ECN_ALLOWED : ECN_NOCARE, 320 &otos, &ip->ip_tos) == 0) { 321 m_freem(m); 322 return (IPPROTO_DONE); 323 } 324 break; 325 } 326 #endif 327 #ifdef INET6 328 case IPPROTO_IPV6: 329 { 330 struct ip6_hdr *ip6; 331 u_int8_t itos, oitos; 332 333 af = AF_INET6; 334 if (m->m_len < sizeof(*ip6)) { 335 m = m_pullup(m, sizeof(*ip6)); 336 if (!m) 337 return (IPPROTO_DONE); 338 } 339 ip6 = mtod(m, struct ip6_hdr *); 340 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 341 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 342 ECN_ALLOWED : ECN_NOCARE, 343 &otos, &itos) == 0) { 344 m_freem(m); 345 return (IPPROTO_DONE); 346 } 347 if (itos != oitos) { 348 ip6->ip6_flow &= ~htonl(0xff << 20); 349 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 350 } 351 break; 352 } 353 #endif /* INET6 */ 354 case IPPROTO_ETHERIP: 355 af = AF_LINK; 356 break; 357 358 default: 359 KMOD_IPSTAT_INC(ips_nogif); 360 m_freem(m); 361 return (IPPROTO_DONE); 362 } 363 gif_input(m, af, gifp); 364 return (IPPROTO_DONE); 365 } 366 367 /* 368 * validate outer address. 369 */ 370 static int 371 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 372 { 373 struct sockaddr_in *src, *dst; 374 struct in_ifaddr *ia4; 375 376 src = (struct sockaddr_in *)sc->gif_psrc; 377 dst = (struct sockaddr_in *)sc->gif_pdst; 378 379 /* check for address match */ 380 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 381 dst->sin_addr.s_addr != ip->ip_src.s_addr) 382 return 0; 383 384 /* martian filters on outer source - NOT done in ip_input! */ 385 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 386 return 0; 387 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 388 case 0: case 127: case 255: 389 return 0; 390 } 391 392 /* reject packets with broadcast on source */ 393 /* XXXRW: should use hash lists? */ 394 IN_IFADDR_RLOCK(); 395 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 396 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 397 continue; 398 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { 399 IN_IFADDR_RUNLOCK(); 400 return 0; 401 } 402 } 403 IN_IFADDR_RUNLOCK(); 404 405 /* ingress filters on outer source */ 406 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 407 struct sockaddr_in sin; 408 struct rtentry *rt; 409 410 bzero(&sin, sizeof(sin)); 411 sin.sin_family = AF_INET; 412 sin.sin_len = sizeof(struct sockaddr_in); 413 sin.sin_addr = ip->ip_src; 414 /* XXX MRT check for the interface we would use on output */ 415 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 416 0UL, sc->gif_fibnum); 417 if (!rt || rt->rt_ifp != ifp) { 418 #if 0 419 log(LOG_WARNING, "%s: packet from 0x%x dropped " 420 "due to ingress filter\n", if_name(GIF2IFP(sc)), 421 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 422 #endif 423 if (rt) 424 RTFREE_LOCKED(rt); 425 return 0; 426 } 427 RTFREE_LOCKED(rt); 428 } 429 430 return 32 * 2; 431 } 432 433 /* 434 * we know that we are in IFF_UP, outer address available, and outer family 435 * matched the physical addr family. see gif_encapcheck(). 436 */ 437 int 438 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 439 { 440 struct ip ip; 441 struct gif_softc *sc; 442 struct ifnet *ifp; 443 444 /* sanity check done in caller */ 445 sc = (struct gif_softc *)arg; 446 447 /* LINTED const cast */ 448 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 449 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 450 451 return gif_validate4(&ip, sc, ifp); 452 } 453 454 int 455 in_gif_attach(struct gif_softc *sc) 456 { 457 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 458 &in_gif_protosw, sc); 459 if (sc->encap_cookie4 == NULL) 460 return EEXIST; 461 return 0; 462 } 463 464 int 465 in_gif_detach(struct gif_softc *sc) 466 { 467 int error; 468 469 error = encap_detach(sc->encap_cookie4); 470 if (error == 0) 471 sc->encap_cookie4 = NULL; 472 return error; 473 } 474