1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org> 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Heiko W.Rupp <hwr@pilhuhn.de> 10 * 11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 * 34 * $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_inet.h" 41 #include "opt_inet6.h" 42 43 #include <sys/param.h> 44 #include <sys/jail.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/libkern.h> 48 #include <sys/malloc.h> 49 #include <sys/module.h> 50 #include <sys/mbuf.h> 51 #include <sys/priv.h> 52 #include <sys/proc.h> 53 #include <sys/protosw.h> 54 #include <sys/rmlock.h> 55 #include <sys/socket.h> 56 #include <sys/sockio.h> 57 #include <sys/sx.h> 58 #include <sys/sysctl.h> 59 #include <sys/syslog.h> 60 #include <sys/systm.h> 61 62 #include <net/ethernet.h> 63 #include <net/if.h> 64 #include <net/if_var.h> 65 #include <net/if_clone.h> 66 #include <net/if_types.h> 67 #include <net/netisr.h> 68 #include <net/vnet.h> 69 #include <net/route.h> 70 71 #include <netinet/in.h> 72 #ifdef INET 73 #include <netinet/in_systm.h> 74 #include <netinet/in_var.h> 75 #include <netinet/ip.h> 76 #include <netinet/ip_var.h> 77 #endif 78 79 #ifdef INET6 80 #include <netinet/ip6.h> 81 #include <netinet6/in6_var.h> 82 #include <netinet6/ip6_var.h> 83 #include <netinet6/scope6_var.h> 84 #endif 85 86 #include <netinet/ip_encap.h> 87 #include <net/bpf.h> 88 #include <net/if_gre.h> 89 90 #include <machine/in_cksum.h> 91 #include <security/mac/mac_framework.h> 92 93 #define GREMTU 1476 94 static const char grename[] = "gre"; 95 static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation"); 96 static VNET_DEFINE(struct mtx, gre_mtx); 97 #define V_gre_mtx VNET(gre_mtx) 98 #define GRE_LIST_LOCK_INIT(x) mtx_init(&V_gre_mtx, "gre_mtx", NULL, \ 99 MTX_DEF) 100 #define GRE_LIST_LOCK_DESTROY(x) mtx_destroy(&V_gre_mtx) 101 #define GRE_LIST_LOCK(x) mtx_lock(&V_gre_mtx) 102 #define GRE_LIST_UNLOCK(x) mtx_unlock(&V_gre_mtx) 103 104 static VNET_DEFINE(LIST_HEAD(, gre_softc), gre_softc_list); 105 #define V_gre_softc_list VNET(gre_softc_list) 106 static struct sx gre_ioctl_sx; 107 SX_SYSINIT(gre_ioctl_sx, &gre_ioctl_sx, "gre_ioctl"); 108 109 static int gre_clone_create(struct if_clone *, int, caddr_t); 110 static void gre_clone_destroy(struct ifnet *); 111 static VNET_DEFINE(struct if_clone *, gre_cloner); 112 #define V_gre_cloner VNET(gre_cloner) 113 114 static void gre_qflush(struct ifnet *); 115 static int gre_transmit(struct ifnet *, struct mbuf *); 116 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 117 static int gre_output(struct ifnet *, struct mbuf *, 118 const struct sockaddr *, struct route *); 119 120 static void gre_updatehdr(struct gre_softc *); 121 static int gre_set_tunnel(struct ifnet *, struct sockaddr *, 122 struct sockaddr *); 123 static void gre_delete_tunnel(struct ifnet *); 124 125 SYSCTL_DECL(_net_link); 126 static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 127 "Generic Routing Encapsulation"); 128 #ifndef MAX_GRE_NEST 129 /* 130 * This macro controls the default upper limitation on nesting of gre tunnels. 131 * Since, setting a large value to this macro with a careless configuration 132 * may introduce system crash, we don't allow any nestings by default. 133 * If you need to configure nested gre tunnels, you can define this macro 134 * in your kernel configuration file. However, if you do so, please be 135 * careful to configure the tunnels so that it won't make a loop. 136 */ 137 #define MAX_GRE_NEST 1 138 #endif 139 140 static VNET_DEFINE(int, max_gre_nesting) = MAX_GRE_NEST; 141 #define V_max_gre_nesting VNET(max_gre_nesting) 142 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET, 143 &VNET_NAME(max_gre_nesting), 0, "Max nested tunnels"); 144 145 static void 146 vnet_gre_init(const void *unused __unused) 147 { 148 LIST_INIT(&V_gre_softc_list); 149 GRE_LIST_LOCK_INIT(); 150 V_gre_cloner = if_clone_simple(grename, gre_clone_create, 151 gre_clone_destroy, 0); 152 } 153 VNET_SYSINIT(vnet_gre_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 154 vnet_gre_init, NULL); 155 156 static void 157 vnet_gre_uninit(const void *unused __unused) 158 { 159 160 if_clone_detach(V_gre_cloner); 161 GRE_LIST_LOCK_DESTROY(); 162 } 163 VNET_SYSUNINIT(vnet_gre_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 164 vnet_gre_uninit, NULL); 165 166 static int 167 gre_clone_create(struct if_clone *ifc, int unit, caddr_t params) 168 { 169 struct gre_softc *sc; 170 171 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 172 sc->gre_fibnum = curthread->td_proc->p_fibnum; 173 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 174 GRE_LOCK_INIT(sc); 175 GRE2IFP(sc)->if_softc = sc; 176 if_initname(GRE2IFP(sc), grename, unit); 177 178 GRE2IFP(sc)->if_mtu = GREMTU; 179 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 180 GRE2IFP(sc)->if_output = gre_output; 181 GRE2IFP(sc)->if_ioctl = gre_ioctl; 182 GRE2IFP(sc)->if_transmit = gre_transmit; 183 GRE2IFP(sc)->if_qflush = gre_qflush; 184 GRE2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE; 185 GRE2IFP(sc)->if_capenable |= IFCAP_LINKSTATE; 186 if_attach(GRE2IFP(sc)); 187 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 188 GRE_LIST_LOCK(); 189 LIST_INSERT_HEAD(&V_gre_softc_list, sc, gre_list); 190 GRE_LIST_UNLOCK(); 191 return (0); 192 } 193 194 static void 195 gre_clone_destroy(struct ifnet *ifp) 196 { 197 struct gre_softc *sc; 198 199 sx_xlock(&gre_ioctl_sx); 200 sc = ifp->if_softc; 201 gre_delete_tunnel(ifp); 202 GRE_LIST_LOCK(); 203 LIST_REMOVE(sc, gre_list); 204 GRE_LIST_UNLOCK(); 205 bpfdetach(ifp); 206 if_detach(ifp); 207 ifp->if_softc = NULL; 208 sx_xunlock(&gre_ioctl_sx); 209 210 if_free(ifp); 211 GRE_LOCK_DESTROY(sc); 212 free(sc, M_GRE); 213 } 214 215 static int 216 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 217 { 218 GRE_RLOCK_TRACKER; 219 struct ifreq *ifr = (struct ifreq *)data; 220 struct sockaddr *src, *dst; 221 struct gre_softc *sc; 222 #ifdef INET 223 struct sockaddr_in *sin = NULL; 224 #endif 225 #ifdef INET6 226 struct sockaddr_in6 *sin6 = NULL; 227 #endif 228 uint32_t opt; 229 int error; 230 231 switch (cmd) { 232 case SIOCSIFMTU: 233 /* XXX: */ 234 if (ifr->ifr_mtu < 576) 235 return (EINVAL); 236 ifp->if_mtu = ifr->ifr_mtu; 237 return (0); 238 case SIOCSIFADDR: 239 ifp->if_flags |= IFF_UP; 240 case SIOCSIFFLAGS: 241 case SIOCADDMULTI: 242 case SIOCDELMULTI: 243 return (0); 244 case GRESADDRS: 245 case GRESADDRD: 246 case GREGADDRS: 247 case GREGADDRD: 248 case GRESPROTO: 249 case GREGPROTO: 250 return (EOPNOTSUPP); 251 } 252 src = dst = NULL; 253 sx_xlock(&gre_ioctl_sx); 254 sc = ifp->if_softc; 255 if (sc == NULL) { 256 error = ENXIO; 257 goto end; 258 } 259 error = 0; 260 switch (cmd) { 261 case SIOCSIFPHYADDR: 262 #ifdef INET6 263 case SIOCSIFPHYADDR_IN6: 264 #endif 265 error = EINVAL; 266 switch (cmd) { 267 #ifdef INET 268 case SIOCSIFPHYADDR: 269 src = (struct sockaddr *) 270 &(((struct in_aliasreq *)data)->ifra_addr); 271 dst = (struct sockaddr *) 272 &(((struct in_aliasreq *)data)->ifra_dstaddr); 273 break; 274 #endif 275 #ifdef INET6 276 case SIOCSIFPHYADDR_IN6: 277 src = (struct sockaddr *) 278 &(((struct in6_aliasreq *)data)->ifra_addr); 279 dst = (struct sockaddr *) 280 &(((struct in6_aliasreq *)data)->ifra_dstaddr); 281 break; 282 #endif 283 default: 284 error = EAFNOSUPPORT; 285 goto end; 286 } 287 /* sa_family must be equal */ 288 if (src->sa_family != dst->sa_family || 289 src->sa_len != dst->sa_len) 290 goto end; 291 292 /* validate sa_len */ 293 switch (src->sa_family) { 294 #ifdef INET 295 case AF_INET: 296 if (src->sa_len != sizeof(struct sockaddr_in)) 297 goto end; 298 break; 299 #endif 300 #ifdef INET6 301 case AF_INET6: 302 if (src->sa_len != sizeof(struct sockaddr_in6)) 303 goto end; 304 break; 305 #endif 306 default: 307 error = EAFNOSUPPORT; 308 goto end; 309 } 310 /* check sa_family looks sane for the cmd */ 311 error = EAFNOSUPPORT; 312 switch (cmd) { 313 #ifdef INET 314 case SIOCSIFPHYADDR: 315 if (src->sa_family == AF_INET) 316 break; 317 goto end; 318 #endif 319 #ifdef INET6 320 case SIOCSIFPHYADDR_IN6: 321 if (src->sa_family == AF_INET6) 322 break; 323 goto end; 324 #endif 325 } 326 error = EADDRNOTAVAIL; 327 switch (src->sa_family) { 328 #ifdef INET 329 case AF_INET: 330 if (satosin(src)->sin_addr.s_addr == INADDR_ANY || 331 satosin(dst)->sin_addr.s_addr == INADDR_ANY) 332 goto end; 333 break; 334 #endif 335 #ifdef INET6 336 case AF_INET6: 337 if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(src)->sin6_addr) 338 || 339 IN6_IS_ADDR_UNSPECIFIED(&satosin6(dst)->sin6_addr)) 340 goto end; 341 /* 342 * Check validity of the scope zone ID of the 343 * addresses, and convert it into the kernel 344 * internal form if necessary. 345 */ 346 error = sa6_embedscope(satosin6(src), 0); 347 if (error != 0) 348 goto end; 349 error = sa6_embedscope(satosin6(dst), 0); 350 if (error != 0) 351 goto end; 352 #endif 353 } 354 error = gre_set_tunnel(ifp, src, dst); 355 break; 356 case SIOCDIFPHYADDR: 357 gre_delete_tunnel(ifp); 358 break; 359 case SIOCGIFPSRCADDR: 360 case SIOCGIFPDSTADDR: 361 #ifdef INET6 362 case SIOCGIFPSRCADDR_IN6: 363 case SIOCGIFPDSTADDR_IN6: 364 #endif 365 if (sc->gre_family == 0) { 366 error = EADDRNOTAVAIL; 367 break; 368 } 369 GRE_RLOCK(sc); 370 switch (cmd) { 371 #ifdef INET 372 case SIOCGIFPSRCADDR: 373 case SIOCGIFPDSTADDR: 374 if (sc->gre_family != AF_INET) { 375 error = EADDRNOTAVAIL; 376 break; 377 } 378 sin = (struct sockaddr_in *)&ifr->ifr_addr; 379 memset(sin, 0, sizeof(*sin)); 380 sin->sin_family = AF_INET; 381 sin->sin_len = sizeof(*sin); 382 break; 383 #endif 384 #ifdef INET6 385 case SIOCGIFPSRCADDR_IN6: 386 case SIOCGIFPDSTADDR_IN6: 387 if (sc->gre_family != AF_INET6) { 388 error = EADDRNOTAVAIL; 389 break; 390 } 391 sin6 = (struct sockaddr_in6 *) 392 &(((struct in6_ifreq *)data)->ifr_addr); 393 memset(sin6, 0, sizeof(*sin6)); 394 sin6->sin6_family = AF_INET6; 395 sin6->sin6_len = sizeof(*sin6); 396 break; 397 #endif 398 } 399 if (error == 0) { 400 switch (cmd) { 401 #ifdef INET 402 case SIOCGIFPSRCADDR: 403 sin->sin_addr = sc->gre_oip.ip_src; 404 break; 405 case SIOCGIFPDSTADDR: 406 sin->sin_addr = sc->gre_oip.ip_dst; 407 break; 408 #endif 409 #ifdef INET6 410 case SIOCGIFPSRCADDR_IN6: 411 sin6->sin6_addr = sc->gre_oip6.ip6_src; 412 break; 413 case SIOCGIFPDSTADDR_IN6: 414 sin6->sin6_addr = sc->gre_oip6.ip6_dst; 415 break; 416 #endif 417 } 418 } 419 GRE_RUNLOCK(sc); 420 if (error != 0) 421 break; 422 switch (cmd) { 423 #ifdef INET 424 case SIOCGIFPSRCADDR: 425 case SIOCGIFPDSTADDR: 426 error = prison_if(curthread->td_ucred, 427 (struct sockaddr *)sin); 428 if (error != 0) 429 memset(sin, 0, sizeof(*sin)); 430 break; 431 #endif 432 #ifdef INET6 433 case SIOCGIFPSRCADDR_IN6: 434 case SIOCGIFPDSTADDR_IN6: 435 error = prison_if(curthread->td_ucred, 436 (struct sockaddr *)sin6); 437 if (error == 0) 438 error = sa6_recoverscope(sin6); 439 if (error != 0) 440 memset(sin6, 0, sizeof(*sin6)); 441 #endif 442 } 443 break; 444 case SIOCGTUNFIB: 445 ifr->ifr_fib = sc->gre_fibnum; 446 break; 447 case SIOCSTUNFIB: 448 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 449 break; 450 if (ifr->ifr_fib >= rt_numfibs) 451 error = EINVAL; 452 else 453 sc->gre_fibnum = ifr->ifr_fib; 454 break; 455 case GRESKEY: 456 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 457 break; 458 if ((error = copyin(ifr_data_get_ptr(ifr), &opt, 459 sizeof(opt))) != 0) 460 break; 461 if (sc->gre_key != opt) { 462 GRE_WLOCK(sc); 463 sc->gre_key = opt; 464 gre_updatehdr(sc); 465 GRE_WUNLOCK(sc); 466 } 467 break; 468 case GREGKEY: 469 error = copyout(&sc->gre_key, ifr_data_get_ptr(ifr), 470 sizeof(sc->gre_key)); 471 break; 472 case GRESOPTS: 473 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 474 break; 475 if ((error = copyin(ifr_data_get_ptr(ifr), &opt, 476 sizeof(opt))) != 0) 477 break; 478 if (opt & ~GRE_OPTMASK) 479 error = EINVAL; 480 else { 481 if (sc->gre_options != opt) { 482 GRE_WLOCK(sc); 483 sc->gre_options = opt; 484 gre_updatehdr(sc); 485 GRE_WUNLOCK(sc); 486 } 487 } 488 break; 489 490 case GREGOPTS: 491 error = copyout(&sc->gre_options, ifr_data_get_ptr(ifr), 492 sizeof(sc->gre_options)); 493 break; 494 default: 495 error = EINVAL; 496 break; 497 } 498 end: 499 sx_xunlock(&gre_ioctl_sx); 500 return (error); 501 } 502 503 static void 504 gre_updatehdr(struct gre_softc *sc) 505 { 506 struct grehdr *gh = NULL; 507 uint32_t *opts; 508 uint16_t flags; 509 510 GRE_WLOCK_ASSERT(sc); 511 switch (sc->gre_family) { 512 #ifdef INET 513 case AF_INET: 514 sc->gre_hlen = sizeof(struct greip); 515 sc->gre_oip.ip_v = IPPROTO_IPV4; 516 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2; 517 sc->gre_oip.ip_p = IPPROTO_GRE; 518 gh = &sc->gre_gihdr->gi_gre; 519 break; 520 #endif 521 #ifdef INET6 522 case AF_INET6: 523 sc->gre_hlen = sizeof(struct greip6); 524 sc->gre_oip6.ip6_vfc = IPV6_VERSION; 525 sc->gre_oip6.ip6_nxt = IPPROTO_GRE; 526 gh = &sc->gre_gi6hdr->gi6_gre; 527 break; 528 #endif 529 default: 530 return; 531 } 532 flags = 0; 533 opts = gh->gre_opts; 534 if (sc->gre_options & GRE_ENABLE_CSUM) { 535 flags |= GRE_FLAGS_CP; 536 sc->gre_hlen += 2 * sizeof(uint16_t); 537 *opts++ = 0; 538 } 539 if (sc->gre_key != 0) { 540 flags |= GRE_FLAGS_KP; 541 sc->gre_hlen += sizeof(uint32_t); 542 *opts++ = htonl(sc->gre_key); 543 } 544 if (sc->gre_options & GRE_ENABLE_SEQ) { 545 flags |= GRE_FLAGS_SP; 546 sc->gre_hlen += sizeof(uint32_t); 547 *opts++ = 0; 548 } else 549 sc->gre_oseq = 0; 550 gh->gre_flags = htons(flags); 551 } 552 553 static void 554 gre_detach(struct gre_softc *sc) 555 { 556 557 sx_assert(&gre_ioctl_sx, SA_XLOCKED); 558 if (sc->gre_ecookie != NULL) 559 encap_detach(sc->gre_ecookie); 560 sc->gre_ecookie = NULL; 561 } 562 563 static int 564 gre_set_tunnel(struct ifnet *ifp, struct sockaddr *src, 565 struct sockaddr *dst) 566 { 567 struct gre_softc *sc, *tsc; 568 #ifdef INET6 569 struct ip6_hdr *ip6; 570 #endif 571 #ifdef INET 572 struct ip *ip; 573 #endif 574 void *hdr; 575 int error; 576 577 sx_assert(&gre_ioctl_sx, SA_XLOCKED); 578 GRE_LIST_LOCK(); 579 sc = ifp->if_softc; 580 LIST_FOREACH(tsc, &V_gre_softc_list, gre_list) { 581 if (tsc == sc || tsc->gre_family != src->sa_family) 582 continue; 583 #ifdef INET 584 if (tsc->gre_family == AF_INET && 585 tsc->gre_oip.ip_src.s_addr == 586 satosin(src)->sin_addr.s_addr && 587 tsc->gre_oip.ip_dst.s_addr == 588 satosin(dst)->sin_addr.s_addr) { 589 GRE_LIST_UNLOCK(); 590 return (EADDRNOTAVAIL); 591 } 592 #endif 593 #ifdef INET6 594 if (tsc->gre_family == AF_INET6 && 595 IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_src, 596 &satosin6(src)->sin6_addr) && 597 IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_dst, 598 &satosin6(dst)->sin6_addr)) { 599 GRE_LIST_UNLOCK(); 600 return (EADDRNOTAVAIL); 601 } 602 #endif 603 } 604 GRE_LIST_UNLOCK(); 605 606 switch (src->sa_family) { 607 #ifdef INET 608 case AF_INET: 609 hdr = ip = malloc(sizeof(struct greip) + 610 3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO); 611 ip->ip_src = satosin(src)->sin_addr; 612 ip->ip_dst = satosin(dst)->sin_addr; 613 break; 614 #endif 615 #ifdef INET6 616 case AF_INET6: 617 hdr = ip6 = malloc(sizeof(struct greip6) + 618 3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO); 619 ip6->ip6_src = satosin6(src)->sin6_addr; 620 ip6->ip6_dst = satosin6(dst)->sin6_addr; 621 break; 622 #endif 623 default: 624 return (EAFNOSUPPORT); 625 } 626 if (sc->gre_family != 0) 627 gre_detach(sc); 628 GRE_WLOCK(sc); 629 if (sc->gre_family != 0) 630 free(sc->gre_hdr, M_GRE); 631 sc->gre_family = src->sa_family; 632 sc->gre_hdr = hdr; 633 sc->gre_oseq = 0; 634 sc->gre_iseq = UINT32_MAX; 635 gre_updatehdr(sc); 636 GRE_WUNLOCK(sc); 637 638 error = 0; 639 switch (src->sa_family) { 640 #ifdef INET 641 case AF_INET: 642 error = in_gre_attach(sc); 643 break; 644 #endif 645 #ifdef INET6 646 case AF_INET6: 647 error = in6_gre_attach(sc); 648 break; 649 #endif 650 } 651 if (error == 0) { 652 ifp->if_drv_flags |= IFF_DRV_RUNNING; 653 if_link_state_change(ifp, LINK_STATE_UP); 654 } 655 return (error); 656 } 657 658 static void 659 gre_delete_tunnel(struct ifnet *ifp) 660 { 661 struct gre_softc *sc = ifp->if_softc; 662 int family; 663 664 GRE_WLOCK(sc); 665 family = sc->gre_family; 666 sc->gre_family = 0; 667 GRE_WUNLOCK(sc); 668 if (family != 0) { 669 gre_detach(sc); 670 free(sc->gre_hdr, M_GRE); 671 } 672 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 673 if_link_state_change(ifp, LINK_STATE_DOWN); 674 } 675 676 int 677 gre_input(struct mbuf **mp, int *offp, int proto) 678 { 679 struct gre_softc *sc; 680 struct grehdr *gh; 681 struct ifnet *ifp; 682 struct mbuf *m; 683 uint32_t *opts; 684 #ifdef notyet 685 uint32_t key; 686 #endif 687 uint16_t flags; 688 int hlen, isr, af; 689 690 m = *mp; 691 sc = encap_getarg(m); 692 KASSERT(sc != NULL, ("encap_getarg returned NULL")); 693 694 ifp = GRE2IFP(sc); 695 hlen = *offp + sizeof(struct grehdr) + 4 * sizeof(uint32_t); 696 if (m->m_pkthdr.len < hlen) 697 goto drop; 698 if (m->m_len < hlen) { 699 m = m_pullup(m, hlen); 700 if (m == NULL) 701 goto drop; 702 } 703 gh = (struct grehdr *)mtodo(m, *offp); 704 flags = ntohs(gh->gre_flags); 705 if (flags & ~GRE_FLAGS_MASK) 706 goto drop; 707 opts = gh->gre_opts; 708 hlen = 2 * sizeof(uint16_t); 709 if (flags & GRE_FLAGS_CP) { 710 /* reserved1 field must be zero */ 711 if (((uint16_t *)opts)[1] != 0) 712 goto drop; 713 if (in_cksum_skip(m, m->m_pkthdr.len, *offp) != 0) 714 goto drop; 715 hlen += 2 * sizeof(uint16_t); 716 opts++; 717 } 718 if (flags & GRE_FLAGS_KP) { 719 #ifdef notyet 720 /* 721 * XXX: The current implementation uses the key only for outgoing 722 * packets. But we can check the key value here, or even in the 723 * encapcheck function. 724 */ 725 key = ntohl(*opts); 726 #endif 727 hlen += sizeof(uint32_t); 728 opts++; 729 } 730 #ifdef notyet 731 } else 732 key = 0; 733 734 if (sc->gre_key != 0 && (key != sc->gre_key || key != 0)) 735 goto drop; 736 #endif 737 if (flags & GRE_FLAGS_SP) { 738 #ifdef notyet 739 seq = ntohl(*opts); 740 #endif 741 hlen += sizeof(uint32_t); 742 } 743 switch (ntohs(gh->gre_proto)) { 744 case ETHERTYPE_WCCP: 745 /* 746 * For WCCP skip an additional 4 bytes if after GRE header 747 * doesn't follow an IP header. 748 */ 749 if (flags == 0 && (*(uint8_t *)gh->gre_opts & 0xF0) != 0x40) 750 hlen += sizeof(uint32_t); 751 /* FALLTHROUGH */ 752 case ETHERTYPE_IP: 753 isr = NETISR_IP; 754 af = AF_INET; 755 break; 756 case ETHERTYPE_IPV6: 757 isr = NETISR_IPV6; 758 af = AF_INET6; 759 break; 760 default: 761 goto drop; 762 } 763 m_adj(m, *offp + hlen); 764 m_clrprotoflags(m); 765 m->m_pkthdr.rcvif = ifp; 766 M_SETFIB(m, ifp->if_fib); 767 #ifdef MAC 768 mac_ifnet_create_mbuf(ifp, m); 769 #endif 770 BPF_MTAP2(ifp, &af, sizeof(af), m); 771 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 772 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 773 if ((ifp->if_flags & IFF_MONITOR) != 0) 774 m_freem(m); 775 else 776 netisr_dispatch(isr, m); 777 return (IPPROTO_DONE); 778 drop: 779 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); 780 m_freem(m); 781 return (IPPROTO_DONE); 782 } 783 784 #define MTAG_GRE 1307983903 785 static int 786 gre_check_nesting(struct ifnet *ifp, struct mbuf *m) 787 { 788 struct m_tag *mtag; 789 int count; 790 791 count = 1; 792 mtag = NULL; 793 while ((mtag = m_tag_locate(m, MTAG_GRE, 0, mtag)) != NULL) { 794 if (*(struct ifnet **)(mtag + 1) == ifp) { 795 log(LOG_NOTICE, "%s: loop detected\n", ifp->if_xname); 796 return (EIO); 797 } 798 count++; 799 } 800 if (count > V_max_gre_nesting) { 801 log(LOG_NOTICE, 802 "%s: if_output recursively called too many times(%d)\n", 803 ifp->if_xname, count); 804 return (EIO); 805 } 806 mtag = m_tag_alloc(MTAG_GRE, 0, sizeof(struct ifnet *), M_NOWAIT); 807 if (mtag == NULL) 808 return (ENOMEM); 809 *(struct ifnet **)(mtag + 1) = ifp; 810 m_tag_prepend(m, mtag); 811 return (0); 812 } 813 814 static int 815 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 816 struct route *ro) 817 { 818 uint32_t af; 819 int error; 820 821 #ifdef MAC 822 error = mac_ifnet_check_transmit(ifp, m); 823 if (error != 0) 824 goto drop; 825 #endif 826 if ((ifp->if_flags & IFF_MONITOR) != 0 || 827 (ifp->if_flags & IFF_UP) == 0) { 828 error = ENETDOWN; 829 goto drop; 830 } 831 832 error = gre_check_nesting(ifp, m); 833 if (error != 0) 834 goto drop; 835 836 m->m_flags &= ~(M_BCAST|M_MCAST); 837 if (dst->sa_family == AF_UNSPEC) 838 bcopy(dst->sa_data, &af, sizeof(af)); 839 else 840 af = dst->sa_family; 841 BPF_MTAP2(ifp, &af, sizeof(af), m); 842 m->m_pkthdr.csum_data = af; /* save af for if_transmit */ 843 return (ifp->if_transmit(ifp, m)); 844 drop: 845 m_freem(m); 846 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); 847 return (error); 848 } 849 850 static void 851 gre_setseqn(struct grehdr *gh, uint32_t seq) 852 { 853 uint32_t *opts; 854 uint16_t flags; 855 856 opts = gh->gre_opts; 857 flags = ntohs(gh->gre_flags); 858 KASSERT((flags & GRE_FLAGS_SP) != 0, 859 ("gre_setseqn called, but GRE_FLAGS_SP isn't set ")); 860 if (flags & GRE_FLAGS_CP) 861 opts++; 862 if (flags & GRE_FLAGS_KP) 863 opts++; 864 *opts = htonl(seq); 865 } 866 867 static int 868 gre_transmit(struct ifnet *ifp, struct mbuf *m) 869 { 870 GRE_RLOCK_TRACKER; 871 struct gre_softc *sc; 872 struct grehdr *gh; 873 uint32_t iaf, oaf, oseq; 874 int error, hlen, olen, plen; 875 int want_seq, want_csum; 876 877 plen = 0; 878 sc = ifp->if_softc; 879 if (sc == NULL) { 880 error = ENETDOWN; 881 m_freem(m); 882 goto drop; 883 } 884 GRE_RLOCK(sc); 885 if (sc->gre_family == 0) { 886 GRE_RUNLOCK(sc); 887 error = ENETDOWN; 888 m_freem(m); 889 goto drop; 890 } 891 iaf = m->m_pkthdr.csum_data; 892 oaf = sc->gre_family; 893 hlen = sc->gre_hlen; 894 want_seq = (sc->gre_options & GRE_ENABLE_SEQ) != 0; 895 if (want_seq) 896 oseq = sc->gre_oseq++; /* XXX */ 897 else 898 oseq = 0; /* Make compiler happy. */ 899 want_csum = (sc->gre_options & GRE_ENABLE_CSUM) != 0; 900 M_SETFIB(m, sc->gre_fibnum); 901 M_PREPEND(m, hlen, M_NOWAIT); 902 if (m == NULL) { 903 GRE_RUNLOCK(sc); 904 error = ENOBUFS; 905 goto drop; 906 } 907 bcopy(sc->gre_hdr, mtod(m, void *), hlen); 908 GRE_RUNLOCK(sc); 909 switch (oaf) { 910 #ifdef INET 911 case AF_INET: 912 olen = sizeof(struct ip); 913 break; 914 #endif 915 #ifdef INET6 916 case AF_INET6: 917 olen = sizeof(struct ip6_hdr); 918 break; 919 #endif 920 default: 921 error = ENETDOWN; 922 goto drop; 923 } 924 gh = (struct grehdr *)mtodo(m, olen); 925 switch (iaf) { 926 #ifdef INET 927 case AF_INET: 928 gh->gre_proto = htons(ETHERTYPE_IP); 929 break; 930 #endif 931 #ifdef INET6 932 case AF_INET6: 933 gh->gre_proto = htons(ETHERTYPE_IPV6); 934 break; 935 #endif 936 default: 937 error = ENETDOWN; 938 goto drop; 939 } 940 if (want_seq) 941 gre_setseqn(gh, oseq); 942 if (want_csum) { 943 *(uint16_t *)gh->gre_opts = in_cksum_skip(m, 944 m->m_pkthdr.len, olen); 945 } 946 plen = m->m_pkthdr.len - hlen; 947 switch (oaf) { 948 #ifdef INET 949 case AF_INET: 950 error = in_gre_output(m, iaf, hlen); 951 break; 952 #endif 953 #ifdef INET6 954 case AF_INET6: 955 error = in6_gre_output(m, iaf, hlen); 956 break; 957 #endif 958 default: 959 m_freem(m); 960 error = ENETDOWN; 961 } 962 drop: 963 if (error) 964 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); 965 else { 966 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 967 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen); 968 } 969 return (error); 970 } 971 972 static void 973 gre_qflush(struct ifnet *ifp __unused) 974 { 975 976 } 977 978 static int 979 gremodevent(module_t mod, int type, void *data) 980 { 981 982 switch (type) { 983 case MOD_LOAD: 984 case MOD_UNLOAD: 985 break; 986 default: 987 return (EOPNOTSUPP); 988 } 989 return (0); 990 } 991 992 static moduledata_t gre_mod = { 993 "if_gre", 994 gremodevent, 995 0 996 }; 997 998 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 999 MODULE_VERSION(if_gre, 1); 1000