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