1 /*- 2 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 33 #include <sys/param.h> 34 #include <sys/jail.h> 35 #include <sys/systm.h> 36 #include <sys/socket.h> 37 #include <sys/socketvar.h> 38 #include <sys/sockio.h> 39 #include <sys/mbuf.h> 40 #include <sys/errno.h> 41 #include <sys/kernel.h> 42 #include <sys/sysctl.h> 43 #include <sys/malloc.h> 44 #include <sys/proc.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/vnet.h> 49 50 #include <netinet/in.h> 51 #ifdef INET 52 #include <net/ethernet.h> 53 #include <netinet/ip.h> 54 #endif 55 #include <netinet/in_pcb.h> 56 #include <netinet/ip_encap.h> 57 #include <netinet/ip_var.h> 58 #include <netinet/ip6.h> 59 #include <netinet/udp.h> 60 #include <netinet/udp_var.h> 61 #include <netinet6/ip6_var.h> 62 #include <netinet6/in6_var.h> 63 #include <netinet6/scope6_var.h> 64 #include <net/if_gre.h> 65 66 VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM; 67 #define V_ip6_gre_hlim VNET(ip6_gre_hlim) 68 69 SYSCTL_DECL(_net_inet6_ip6); 70 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW, 71 &VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets"); 72 73 struct in6_gre_socket { 74 struct gre_socket base; 75 struct in6_addr addr; /* scope zone id is embedded */ 76 }; 77 VNET_DEFINE_STATIC(struct gre_sockets *, ipv6_sockets) = NULL; 78 VNET_DEFINE_STATIC(struct gre_list *, ipv6_hashtbl) = NULL; 79 VNET_DEFINE_STATIC(struct gre_list *, ipv6_srchashtbl) = NULL; 80 #define V_ipv6_sockets VNET(ipv6_sockets) 81 #define V_ipv6_hashtbl VNET(ipv6_hashtbl) 82 #define V_ipv6_srchashtbl VNET(ipv6_srchashtbl) 83 #define GRE_HASH(src, dst) (V_ipv6_hashtbl[\ 84 in6_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) 85 #define GRE_SRCHASH(src) (V_ipv6_srchashtbl[\ 86 fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)]) 87 #define GRE_SOCKHASH(src) (V_ipv6_sockets[\ 88 fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)]) 89 #define GRE_HASH_SC(sc) GRE_HASH(&(sc)->gre_oip6.ip6_src,\ 90 &(sc)->gre_oip6.ip6_dst) 91 92 static uint32_t 93 in6_gre_hashval(const struct in6_addr *src, const struct in6_addr *dst) 94 { 95 uint32_t ret; 96 97 ret = fnv_32_buf(src, sizeof(*src), FNV1_32_INIT); 98 return (fnv_32_buf(dst, sizeof(*dst), ret)); 99 } 100 101 static struct gre_socket* 102 in6_gre_lookup_socket(const struct in6_addr *addr) 103 { 104 struct gre_socket *gs; 105 struct in6_gre_socket *s; 106 107 CK_LIST_FOREACH(gs, &GRE_SOCKHASH(addr), chain) { 108 s = __containerof(gs, struct in6_gre_socket, base); 109 if (IN6_ARE_ADDR_EQUAL(&s->addr, addr)) 110 break; 111 } 112 return (gs); 113 } 114 115 static int 116 in6_gre_checkdup(const struct gre_softc *sc, const struct in6_addr *src, 117 const struct in6_addr *dst, uint32_t opts) 118 { 119 struct gre_list *head; 120 struct gre_softc *tmp; 121 struct gre_socket *gs; 122 123 if (sc->gre_family == AF_INET6 && 124 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, src) && 125 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, dst) && 126 (sc->gre_options & GRE_UDPENCAP) == (opts & GRE_UDPENCAP)) 127 return (EEXIST); 128 129 if (opts & GRE_UDPENCAP) { 130 gs = in6_gre_lookup_socket(src); 131 if (gs == NULL) 132 return (0); 133 head = &gs->list; 134 } else 135 head = &GRE_HASH(src, dst); 136 137 CK_LIST_FOREACH(tmp, head, chain) { 138 if (tmp == sc) 139 continue; 140 if (IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_src, src) && 141 IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_dst, dst)) 142 return (EADDRNOTAVAIL); 143 } 144 return (0); 145 } 146 147 static int 148 in6_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) 149 { 150 const struct ip6_hdr *ip6; 151 struct gre_softc *sc; 152 153 if (V_ipv6_hashtbl == NULL) 154 return (0); 155 156 NET_EPOCH_ASSERT(); 157 ip6 = mtod(m, const struct ip6_hdr *); 158 CK_LIST_FOREACH(sc, &GRE_HASH(&ip6->ip6_dst, &ip6->ip6_src), chain) { 159 /* 160 * This is an inbound packet, its ip6_dst is source address 161 * in softc. 162 */ 163 if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, 164 &ip6->ip6_dst) && 165 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, 166 &ip6->ip6_src)) { 167 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 168 return (0); 169 *arg = sc; 170 return (ENCAP_DRV_LOOKUP); 171 } 172 } 173 return (0); 174 } 175 176 /* 177 * Check that ingress address belongs to local host. 178 */ 179 static void 180 in6_gre_set_running(struct gre_softc *sc) 181 { 182 183 if (in6_localip(&sc->gre_oip6.ip6_src)) 184 GRE2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING; 185 else 186 GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING; 187 } 188 189 /* 190 * ifaddr_event handler. 191 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent 192 * source address spoofing. 193 */ 194 static void 195 in6_gre_srcaddr(void *arg __unused, const struct sockaddr *sa, 196 int event __unused) 197 { 198 const struct sockaddr_in6 *sin; 199 struct gre_softc *sc; 200 201 /* Check that VNET is ready */ 202 if (V_ipv6_hashtbl == NULL) 203 return; 204 205 NET_EPOCH_ASSERT(); 206 sin = (const struct sockaddr_in6 *)sa; 207 CK_LIST_FOREACH(sc, &GRE_SRCHASH(&sin->sin6_addr), srchash) { 208 if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, 209 &sin->sin6_addr) == 0) 210 continue; 211 in6_gre_set_running(sc); 212 } 213 } 214 215 static bool 216 in6_gre_udp_input(struct mbuf *m, int off, struct inpcb *inp, 217 const struct sockaddr *sa, void *ctx) 218 { 219 struct gre_socket *gs; 220 struct gre_softc *sc; 221 struct sockaddr_in6 dst; 222 223 NET_EPOCH_ASSERT(); 224 225 gs = (struct gre_socket *)ctx; 226 dst = *(const struct sockaddr_in6 *)sa; 227 if (sa6_embedscope(&dst, 0)) { 228 m_freem(m); 229 return (true); 230 } 231 CK_LIST_FOREACH(sc, &gs->list, chain) { 232 if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, &dst.sin6_addr)) 233 break; 234 } 235 if (sc != NULL && (GRE2IFP(sc)->if_flags & IFF_UP) != 0){ 236 gre_input(m, off + sizeof(struct udphdr), IPPROTO_UDP, sc); 237 return (true); 238 } 239 m_freem(m); 240 241 return (true); 242 } 243 244 static int 245 in6_gre_setup_socket(struct gre_softc *sc) 246 { 247 struct sockopt sopt; 248 struct sockaddr_in6 sin6; 249 struct in6_gre_socket *s; 250 struct gre_socket *gs; 251 int error, value; 252 253 /* 254 * NOTE: we are protected with gre_ioctl_sx lock. 255 * 256 * First check that socket is already configured. 257 * If so, check that source addres was not changed. 258 * If address is different, check that there are no other tunnels 259 * and close socket. 260 */ 261 gs = sc->gre_so; 262 if (gs != NULL) { 263 s = __containerof(gs, struct in6_gre_socket, base); 264 if (!IN6_ARE_ADDR_EQUAL(&s->addr, &sc->gre_oip6.ip6_src)) { 265 if (CK_LIST_EMPTY(&gs->list)) { 266 CK_LIST_REMOVE(gs, chain); 267 soclose(gs->so); 268 NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx); 269 } 270 gs = sc->gre_so = NULL; 271 } 272 } 273 274 if (gs == NULL) { 275 /* 276 * Check that socket for given address is already 277 * configured. 278 */ 279 gs = in6_gre_lookup_socket(&sc->gre_oip6.ip6_src); 280 if (gs == NULL) { 281 s = malloc(sizeof(*s), M_GRE, M_WAITOK | M_ZERO); 282 s->addr = sc->gre_oip6.ip6_src; 283 gs = &s->base; 284 285 error = socreate(sc->gre_family, &gs->so, 286 SOCK_DGRAM, IPPROTO_UDP, curthread->td_ucred, 287 curthread); 288 if (error != 0) { 289 if_printf(GRE2IFP(sc), 290 "cannot create socket: %d\n", error); 291 free(s, M_GRE); 292 return (error); 293 } 294 295 error = udp_set_kernel_tunneling(gs->so, 296 in6_gre_udp_input, NULL, gs); 297 if (error != 0) { 298 if_printf(GRE2IFP(sc), 299 "cannot set UDP tunneling: %d\n", error); 300 goto fail; 301 } 302 303 memset(&sopt, 0, sizeof(sopt)); 304 sopt.sopt_dir = SOPT_SET; 305 sopt.sopt_level = IPPROTO_IPV6; 306 sopt.sopt_name = IPV6_BINDANY; 307 sopt.sopt_val = &value; 308 sopt.sopt_valsize = sizeof(value); 309 value = 1; 310 error = sosetopt(gs->so, &sopt); 311 if (error != 0) { 312 if_printf(GRE2IFP(sc), 313 "cannot set IPV6_BINDANY opt: %d\n", 314 error); 315 goto fail; 316 } 317 318 memset(&sin6, 0, sizeof(sin6)); 319 sin6.sin6_family = AF_INET6; 320 sin6.sin6_len = sizeof(sin6); 321 sin6.sin6_addr = sc->gre_oip6.ip6_src; 322 sin6.sin6_port = htons(GRE_UDPPORT); 323 error = sa6_recoverscope(&sin6); 324 if (error != 0) { 325 if_printf(GRE2IFP(sc), 326 "cannot determine scope zone id: %d\n", 327 error); 328 goto fail; 329 } 330 error = sobind(gs->so, (struct sockaddr *)&sin6, 331 curthread); 332 if (error != 0) { 333 if_printf(GRE2IFP(sc), 334 "cannot bind socket: %d\n", error); 335 goto fail; 336 } 337 /* Add socket to the chain */ 338 CK_LIST_INSERT_HEAD( 339 &GRE_SOCKHASH(&sc->gre_oip6.ip6_src), gs, chain); 340 } 341 } 342 343 /* Add softc to the socket's list */ 344 CK_LIST_INSERT_HEAD(&gs->list, sc, chain); 345 sc->gre_so = gs; 346 return (0); 347 fail: 348 soclose(gs->so); 349 free(s, M_GRE); 350 return (error); 351 } 352 353 static int 354 in6_gre_attach(struct gre_softc *sc) 355 { 356 struct grehdr *gh; 357 int error; 358 359 if (sc->gre_options & GRE_UDPENCAP) { 360 sc->gre_csumflags = CSUM_UDP_IPV6; 361 sc->gre_hlen = sizeof(struct greudp6); 362 sc->gre_oip6.ip6_nxt = IPPROTO_UDP; 363 gh = &sc->gre_udp6hdr->gi6_gre; 364 gre_update_udphdr(sc, &sc->gre_udp6, 365 in6_cksum_pseudo(&sc->gre_oip6, 0, 0, 0)); 366 } else { 367 sc->gre_hlen = sizeof(struct greip6); 368 sc->gre_oip6.ip6_nxt = IPPROTO_GRE; 369 gh = &sc->gre_ip6hdr->gi6_gre; 370 } 371 sc->gre_oip6.ip6_vfc = IPV6_VERSION; 372 gre_update_hdr(sc, gh); 373 374 /* 375 * If we return error, this means that sc is not linked, 376 * and caller should reset gre_family and free(sc->gre_hdr). 377 */ 378 if (sc->gre_options & GRE_UDPENCAP) { 379 error = in6_gre_setup_socket(sc); 380 if (error != 0) 381 return (error); 382 } else 383 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); 384 CK_LIST_INSERT_HEAD(&GRE_SRCHASH(&sc->gre_oip6.ip6_src), sc, srchash); 385 386 /* Set IFF_DRV_RUNNING if interface is ready */ 387 in6_gre_set_running(sc); 388 return (0); 389 } 390 391 int 392 in6_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) 393 { 394 int error; 395 396 /* NOTE: we are protected with gre_ioctl_sx lock */ 397 MPASS(cmd == GRESKEY || cmd == GRESOPTS || cmd == GRESPORT); 398 MPASS(sc->gre_family == AF_INET6); 399 400 /* 401 * If we are going to change encapsulation protocol, do check 402 * for duplicate tunnels. Return EEXIST here to do not confuse 403 * user. 404 */ 405 if (cmd == GRESOPTS && 406 (sc->gre_options & GRE_UDPENCAP) != (value & GRE_UDPENCAP) && 407 in6_gre_checkdup(sc, &sc->gre_oip6.ip6_src, 408 &sc->gre_oip6.ip6_dst, value) == EADDRNOTAVAIL) 409 return (EEXIST); 410 411 CK_LIST_REMOVE(sc, chain); 412 CK_LIST_REMOVE(sc, srchash); 413 GRE_WAIT(); 414 switch (cmd) { 415 case GRESKEY: 416 sc->gre_key = value; 417 break; 418 case GRESOPTS: 419 sc->gre_options = value; 420 break; 421 case GRESPORT: 422 sc->gre_port = value; 423 break; 424 } 425 error = in6_gre_attach(sc); 426 if (error != 0) { 427 sc->gre_family = 0; 428 free(sc->gre_hdr, M_GRE); 429 } 430 return (error); 431 } 432 433 int 434 in6_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) 435 { 436 struct in6_ifreq *ifr = (struct in6_ifreq *)data; 437 struct sockaddr_in6 *dst, *src; 438 struct ip6_hdr *ip6; 439 int error; 440 441 /* NOTE: we are protected with gre_ioctl_sx lock */ 442 error = EINVAL; 443 switch (cmd) { 444 case SIOCSIFPHYADDR_IN6: 445 src = &((struct in6_aliasreq *)data)->ifra_addr; 446 dst = &((struct in6_aliasreq *)data)->ifra_dstaddr; 447 448 /* sanity checks */ 449 if (src->sin6_family != dst->sin6_family || 450 src->sin6_family != AF_INET6 || 451 src->sin6_len != dst->sin6_len || 452 src->sin6_len != sizeof(*src)) 453 break; 454 if (IN6_IS_ADDR_UNSPECIFIED(&src->sin6_addr) || 455 IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) { 456 error = EADDRNOTAVAIL; 457 break; 458 } 459 /* 460 * Check validity of the scope zone ID of the 461 * addresses, and convert it into the kernel 462 * internal form if necessary. 463 */ 464 if ((error = sa6_embedscope(src, 0)) != 0 || 465 (error = sa6_embedscope(dst, 0)) != 0) 466 break; 467 468 if (V_ipv6_hashtbl == NULL) { 469 V_ipv6_hashtbl = gre_hashinit(); 470 V_ipv6_srchashtbl = gre_hashinit(); 471 V_ipv6_sockets = (struct gre_sockets *)gre_hashinit(); 472 } 473 error = in6_gre_checkdup(sc, &src->sin6_addr, 474 &dst->sin6_addr, sc->gre_options); 475 if (error == EADDRNOTAVAIL) 476 break; 477 if (error == EEXIST) { 478 /* Addresses are the same. Just return. */ 479 error = 0; 480 break; 481 } 482 ip6 = malloc(sizeof(struct greudp6) + 3 * sizeof(uint32_t), 483 M_GRE, M_WAITOK | M_ZERO); 484 ip6->ip6_src = src->sin6_addr; 485 ip6->ip6_dst = dst->sin6_addr; 486 if (sc->gre_family != 0) { 487 /* Detach existing tunnel first */ 488 CK_LIST_REMOVE(sc, chain); 489 CK_LIST_REMOVE(sc, srchash); 490 GRE_WAIT(); 491 free(sc->gre_hdr, M_GRE); 492 /* XXX: should we notify about link state change? */ 493 } 494 sc->gre_family = AF_INET6; 495 sc->gre_hdr = ip6; 496 sc->gre_oseq = 0; 497 sc->gre_iseq = UINT32_MAX; 498 error = in6_gre_attach(sc); 499 if (error != 0) { 500 sc->gre_family = 0; 501 free(sc->gre_hdr, M_GRE); 502 } 503 break; 504 case SIOCGIFPSRCADDR_IN6: 505 case SIOCGIFPDSTADDR_IN6: 506 if (sc->gre_family != AF_INET6) { 507 error = EADDRNOTAVAIL; 508 break; 509 } 510 src = (struct sockaddr_in6 *)&ifr->ifr_addr; 511 memset(src, 0, sizeof(*src)); 512 src->sin6_family = AF_INET6; 513 src->sin6_len = sizeof(*src); 514 src->sin6_addr = (cmd == SIOCGIFPSRCADDR_IN6) ? 515 sc->gre_oip6.ip6_src: sc->gre_oip6.ip6_dst; 516 error = prison_if(curthread->td_ucred, (struct sockaddr *)src); 517 if (error == 0) 518 error = sa6_recoverscope(src); 519 if (error != 0) 520 memset(src, 0, sizeof(*src)); 521 break; 522 } 523 return (error); 524 } 525 526 int 527 in6_gre_output(struct mbuf *m, int af __unused, int hlen __unused, 528 uint32_t flowid) 529 { 530 struct greip6 *gi6; 531 532 gi6 = mtod(m, struct greip6 *); 533 gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim; 534 gi6->gi6_ip6.ip6_flow |= flowid & IPV6_FLOWLABEL_MASK; 535 return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL)); 536 } 537 538 static const struct srcaddrtab *ipv6_srcaddrtab = NULL; 539 static const struct encaptab *ecookie = NULL; 540 static const struct encap_config ipv6_encap_cfg = { 541 .proto = IPPROTO_GRE, 542 .min_length = sizeof(struct greip6) + 543 #ifdef INET 544 sizeof(struct ip), 545 #else 546 sizeof(struct ip6_hdr), 547 #endif 548 .exact_match = ENCAP_DRV_LOOKUP, 549 .lookup = in6_gre_lookup, 550 .input = gre_input 551 }; 552 553 void 554 in6_gre_init(void) 555 { 556 557 if (!IS_DEFAULT_VNET(curvnet)) 558 return; 559 ipv6_srcaddrtab = ip6_encap_register_srcaddr(in6_gre_srcaddr, 560 NULL, M_WAITOK); 561 ecookie = ip6_encap_attach(&ipv6_encap_cfg, NULL, M_WAITOK); 562 } 563 564 void 565 in6_gre_uninit(void) 566 { 567 568 if (IS_DEFAULT_VNET(curvnet)) { 569 ip6_encap_detach(ecookie); 570 ip6_encap_unregister_srcaddr(ipv6_srcaddrtab); 571 } 572 if (V_ipv6_hashtbl != NULL) { 573 gre_hashdestroy(V_ipv6_hashtbl); 574 V_ipv6_hashtbl = NULL; 575 GRE_WAIT(); 576 gre_hashdestroy(V_ipv6_srchashtbl); 577 gre_hashdestroy((struct gre_list *)V_ipv6_sockets); 578 } 579 } 580