in_gif.c revision 193664
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: head/sys/netinet/in_gif.c 193664 2009-06-07 23:00:40Z hrs $"); 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#include <sys/vimage.h> 50 51#include <net/if.h> 52#include <net/route.h> 53 54#include <netinet/in.h> 55#include <netinet/in_systm.h> 56#include <netinet/ip.h> 57#include <netinet/ip_var.h> 58#include <netinet/in_gif.h> 59#include <netinet/in_var.h> 60#include <netinet/ip_encap.h> 61#include <netinet/ip_ecn.h> 62#include <netinet/vinet.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 74static int gif_validate4(const struct ip *, struct gif_softc *, 75 struct ifnet *); 76 77extern struct domain inetdomain; 78struct 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#ifdef VIMAGE_GLOBALS 90extern int ip_gif_ttl; 91#endif 92SYSCTL_V_INT(V_NET, vnet_gif, _net_inet_ip, IPCTL_GIF_TTL, gifttl, 93 CTLFLAG_RW, ip_gif_ttl, 0, ""); 94 95int 96in_gif_output(struct ifnet *ifp, int family, struct mbuf *m) 97{ 98 INIT_VNET_GIF(ifp->if_vnet); 99 struct gif_softc *sc = ifp->if_softc; 100 struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst; 101 struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc; 102 struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst; 103 struct ip iphdr; /* capsule IP header, host byte ordered */ 104 struct etherip_header eiphdr; 105 int error, len, proto; 106 u_int8_t tos; 107 108 GIF_LOCK_ASSERT(sc); 109 110 if (sin_src == NULL || sin_dst == NULL || 111 sin_src->sin_family != AF_INET || 112 sin_dst->sin_family != AF_INET) { 113 m_freem(m); 114 return EAFNOSUPPORT; 115 } 116 117 switch (family) { 118#ifdef INET 119 case AF_INET: 120 { 121 struct ip *ip; 122 123 proto = IPPROTO_IPV4; 124 if (m->m_len < sizeof(*ip)) { 125 m = m_pullup(m, sizeof(*ip)); 126 if (!m) 127 return ENOBUFS; 128 } 129 ip = mtod(m, struct ip *); 130 tos = ip->ip_tos; 131 break; 132 } 133#endif /* INET */ 134#ifdef INET6 135 case AF_INET6: 136 { 137 struct ip6_hdr *ip6; 138 proto = IPPROTO_IPV6; 139 if (m->m_len < sizeof(*ip6)) { 140 m = m_pullup(m, sizeof(*ip6)); 141 if (!m) 142 return ENOBUFS; 143 } 144 ip6 = mtod(m, struct ip6_hdr *); 145 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 146 break; 147 } 148#endif /* INET6 */ 149 case AF_LINK: 150 proto = IPPROTO_ETHERIP; 151 152 /* 153 * GIF_SEND_REVETHIP (disabled by default) intentionally 154 * sends an EtherIP packet with revered version field in 155 * the header. This is a knob for backward compatibility 156 * with FreeBSD 7.2R or prior. 157 */ 158 if ((sc->gif_options & GIF_SEND_REVETHIP)) { 159 eiphdr.eip_ver = 0; 160 eiphdr.eip_resvl = ETHERIP_VERSION; 161 eiphdr.eip_resvh = 0; 162 } else { 163 eiphdr.eip_ver = ETHERIP_VERSION; 164 eiphdr.eip_resvl = 0; 165 eiphdr.eip_resvh = 0; 166 } 167 /* prepend Ethernet-in-IP header */ 168 M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); 169 if (m && m->m_len < sizeof(struct etherip_header)) 170 m = m_pullup(m, sizeof(struct etherip_header)); 171 if (m == NULL) 172 return ENOBUFS; 173 bcopy(&eiphdr, mtod(m, struct etherip_header *), 174 sizeof(struct etherip_header)); 175 break; 176 177 default: 178#ifdef DEBUG 179 printf("in_gif_output: warning: unknown family %d passed\n", 180 family); 181#endif 182 m_freem(m); 183 return EAFNOSUPPORT; 184 } 185 186 bzero(&iphdr, sizeof(iphdr)); 187 iphdr.ip_src = sin_src->sin_addr; 188 /* bidirectional configured tunnel mode */ 189 if (sin_dst->sin_addr.s_addr != INADDR_ANY) 190 iphdr.ip_dst = sin_dst->sin_addr; 191 else { 192 m_freem(m); 193 return ENETUNREACH; 194 } 195 iphdr.ip_p = proto; 196 /* version will be set in ip_output() */ 197 iphdr.ip_ttl = V_ip_gif_ttl; 198 iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip); 199 ip_ecn_ingress((ifp->if_flags & IFF_LINK1) ? ECN_ALLOWED : ECN_NOCARE, 200 &iphdr.ip_tos, &tos); 201 202 /* prepend new IP header */ 203 len = sizeof(struct ip); 204#ifndef __NO_STRICT_ALIGNMENT 205 if (family == AF_LINK) 206 len += ETHERIP_ALIGN; 207#endif 208 M_PREPEND(m, len, M_DONTWAIT); 209 if (m != NULL && m->m_len < len) 210 m = m_pullup(m, len); 211 if (m == NULL) { 212 printf("ENOBUFS in in_gif_output %d\n", __LINE__); 213 return ENOBUFS; 214 } 215#ifndef __NO_STRICT_ALIGNMENT 216 if (family == AF_LINK) { 217 len = mtod(m, vm_offset_t) & 3; 218 KASSERT(len == 0 || len == ETHERIP_ALIGN, 219 ("in_gif_output: unexpected misalignment")); 220 m->m_data += len; 221 m->m_len -= ETHERIP_ALIGN; 222 } 223#endif 224 bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip)); 225 226 M_SETFIB(m, sc->gif_fibnum); 227 228 if (dst->sin_family != sin_dst->sin_family || 229 dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) { 230 /* cache route doesn't match */ 231 bzero(dst, sizeof(*dst)); 232 dst->sin_family = sin_dst->sin_family; 233 dst->sin_len = sizeof(struct sockaddr_in); 234 dst->sin_addr = sin_dst->sin_addr; 235 if (sc->gif_ro.ro_rt) { 236 RTFREE(sc->gif_ro.ro_rt); 237 sc->gif_ro.ro_rt = NULL; 238 } 239#if 0 240 GIF2IFP(sc)->if_mtu = GIF_MTU; 241#endif 242 } 243 244 if (sc->gif_ro.ro_rt == NULL) { 245 in_rtalloc_ign(&sc->gif_ro, 0, sc->gif_fibnum); 246 if (sc->gif_ro.ro_rt == NULL) { 247 m_freem(m); 248 return ENETUNREACH; 249 } 250 251 /* if it constitutes infinite encapsulation, punt. */ 252 if (sc->gif_ro.ro_rt->rt_ifp == ifp) { 253 m_freem(m); 254 return ENETUNREACH; /* XXX */ 255 } 256#if 0 257 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu 258 - sizeof(struct ip); 259#endif 260 } 261 262 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 273void 274in_gif_input(struct mbuf *m, int off) 275{ 276 INIT_VNET_INET(curvnet); 277 struct ifnet *gifp = NULL; 278 struct gif_softc *sc; 279 struct ip *ip; 280 int af; 281 u_int8_t otos; 282 int proto; 283 284 ip = mtod(m, struct ip *); 285 proto = ip->ip_p; 286 287 sc = (struct gif_softc *)encap_getarg(m); 288 if (sc == NULL) { 289 m_freem(m); 290 IPSTAT_INC(ips_nogif); 291 return; 292 } 293 294 gifp = GIF2IFP(sc); 295 if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) { 296 m_freem(m); 297 IPSTAT_INC(ips_nogif); 298 return; 299 } 300 301 otos = ip->ip_tos; 302 m_adj(m, off); 303 304 switch (proto) { 305#ifdef INET 306 case IPPROTO_IPV4: 307 { 308 struct ip *ip; 309 af = AF_INET; 310 if (m->m_len < sizeof(*ip)) { 311 m = m_pullup(m, sizeof(*ip)); 312 if (!m) 313 return; 314 } 315 ip = mtod(m, struct ip *); 316 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 317 ECN_ALLOWED : ECN_NOCARE, 318 &otos, &ip->ip_tos) == 0) { 319 m_freem(m); 320 return; 321 } 322 break; 323 } 324#endif 325#ifdef INET6 326 case IPPROTO_IPV6: 327 { 328 struct ip6_hdr *ip6; 329 u_int8_t itos, oitos; 330 331 af = AF_INET6; 332 if (m->m_len < sizeof(*ip6)) { 333 m = m_pullup(m, sizeof(*ip6)); 334 if (!m) 335 return; 336 } 337 ip6 = mtod(m, struct ip6_hdr *); 338 itos = oitos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 339 if (ip_ecn_egress((gifp->if_flags & IFF_LINK1) ? 340 ECN_ALLOWED : ECN_NOCARE, 341 &otos, &itos) == 0) { 342 m_freem(m); 343 return; 344 } 345 if (itos != oitos) { 346 ip6->ip6_flow &= ~htonl(0xff << 20); 347 ip6->ip6_flow |= htonl((u_int32_t)itos << 20); 348 } 349 break; 350 } 351#endif /* INET6 */ 352 case IPPROTO_ETHERIP: 353 af = AF_LINK; 354 break; 355 356 default: 357 IPSTAT_INC(ips_nogif); 358 m_freem(m); 359 return; 360 } 361 gif_input(m, af, gifp); 362 return; 363} 364 365/* 366 * validate outer address. 367 */ 368static int 369gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp) 370{ 371 INIT_VNET_INET(curvnet); 372 struct sockaddr_in *src, *dst; 373 struct in_ifaddr *ia4; 374 375 src = (struct sockaddr_in *)sc->gif_psrc; 376 dst = (struct sockaddr_in *)sc->gif_pdst; 377 378 /* check for address match */ 379 if (src->sin_addr.s_addr != ip->ip_dst.s_addr || 380 dst->sin_addr.s_addr != ip->ip_src.s_addr) 381 return 0; 382 383 /* martian filters on outer source - NOT done in ip_input! */ 384 if (IN_MULTICAST(ntohl(ip->ip_src.s_addr))) 385 return 0; 386 switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) { 387 case 0: case 127: case 255: 388 return 0; 389 } 390 /* reject packets with broadcast on source */ 391 TAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { 392 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) 393 continue; 394 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr) 395 return 0; 396 } 397 398 /* ingress filters on outer source */ 399 if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0 && ifp) { 400 struct sockaddr_in sin; 401 struct rtentry *rt; 402 403 bzero(&sin, sizeof(sin)); 404 sin.sin_family = AF_INET; 405 sin.sin_len = sizeof(struct sockaddr_in); 406 sin.sin_addr = ip->ip_src; 407 /* XXX MRT check for the interface we would use on output */ 408 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 409 0UL, sc->gif_fibnum); 410 if (!rt || rt->rt_ifp != ifp) { 411#if 0 412 log(LOG_WARNING, "%s: packet from 0x%x dropped " 413 "due to ingress filter\n", if_name(GIF2IFP(sc)), 414 (u_int32_t)ntohl(sin.sin_addr.s_addr)); 415#endif 416 if (rt) 417 RTFREE_LOCKED(rt); 418 return 0; 419 } 420 RTFREE_LOCKED(rt); 421 } 422 423 return 32 * 2; 424} 425 426/* 427 * we know that we are in IFF_UP, outer address available, and outer family 428 * matched the physical addr family. see gif_encapcheck(). 429 */ 430int 431gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg) 432{ 433 struct ip ip; 434 struct gif_softc *sc; 435 struct ifnet *ifp; 436 437 /* sanity check done in caller */ 438 sc = (struct gif_softc *)arg; 439 440 /* LINTED const cast */ 441 m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); 442 ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL; 443 444 return gif_validate4(&ip, sc, ifp); 445} 446 447int 448in_gif_attach(struct gif_softc *sc) 449{ 450 sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck, 451 &in_gif_protosw, sc); 452 if (sc->encap_cookie4 == NULL) 453 return EEXIST; 454 return 0; 455} 456 457int 458in_gif_detach(struct gif_softc *sc) 459{ 460 int error; 461 462 error = encap_detach(sc->encap_cookie4); 463 if (error == 0) 464 sc->encap_cookie4 = NULL; 465 return error; 466} 467