1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* L2TPv3 IP encapsulation support for IPv6 3 * 4 * Copyright (c) 2012 Katalix Systems Ltd 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #include <linux/icmp.h> 10 #include <linux/module.h> 11 #include <linux/skbuff.h> 12 #include <linux/random.h> 13 #include <linux/socket.h> 14 #include <linux/l2tp.h> 15 #include <linux/in.h> 16 #include <linux/in6.h> 17 #include <net/sock.h> 18 #include <net/ip.h> 19 #include <net/icmp.h> 20 #include <net/udp.h> 21 #include <net/inet_common.h> 22 #include <net/tcp_states.h> 23 #include <net/protocol.h> 24 #include <net/xfrm.h> 25 #include <net/net_namespace.h> 26 #include <net/netns/generic.h> 27 28 #include <net/transp_v6.h> 29 #include <net/addrconf.h> 30 #include <net/ip6_route.h> 31 32 #include "l2tp_core.h" 33 34 /* per-net private data for this module */ 35 static unsigned int l2tp_ip6_net_id; 36 struct l2tp_ip6_net { 37 rwlock_t l2tp_ip6_lock; 38 struct hlist_head l2tp_ip6_table; 39 struct hlist_head l2tp_ip6_bind_table; 40 }; 41 42 struct l2tp_ip6_sock { 43 /* inet_sock has to be the first member of l2tp_ip6_sock */ 44 struct inet_sock inet; 45 46 u32 conn_id; 47 u32 peer_conn_id; 48 49 struct ipv6_pinfo inet6; 50 }; 51 52 static struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) 53 { 54 return (struct l2tp_ip6_sock *)sk; 55 } 56 57 static struct l2tp_ip6_net *l2tp_ip6_pernet(const struct net *net) 58 { 59 return net_generic(net, l2tp_ip6_net_id); 60 } 61 62 static struct sock *__l2tp_ip6_bind_lookup(const struct net *net, 63 const struct in6_addr *laddr, 64 const struct in6_addr *raddr, 65 int dif, u32 tunnel_id) 66 { 67 struct l2tp_ip6_net *pn = l2tp_ip6_pernet(net); 68 struct sock *sk; 69 70 sk_for_each_bound(sk, &pn->l2tp_ip6_bind_table) { 71 const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk); 72 const struct in6_addr *sk_raddr = &sk->sk_v6_daddr; 73 const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); 74 int bound_dev_if; 75 76 if (!net_eq(sock_net(sk), net)) 77 continue; 78 79 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 80 if (bound_dev_if && dif && bound_dev_if != dif) 81 continue; 82 83 if (sk_laddr && !ipv6_addr_any(sk_laddr) && 84 !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr)) 85 continue; 86 87 if (!ipv6_addr_any(sk_raddr) && raddr && 88 !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr)) 89 continue; 90 91 if (l2tp->conn_id != tunnel_id) 92 continue; 93 94 goto found; 95 } 96 97 sk = NULL; 98 found: 99 return sk; 100 } 101 102 /* When processing receive frames, there are two cases to 103 * consider. Data frames consist of a non-zero session-id and an 104 * optional cookie. Control frames consist of a regular L2TP header 105 * preceded by 32-bits of zeros. 106 * 107 * L2TPv3 Session Header Over IP 108 * 109 * 0 1 2 3 110 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112 * | Session ID | 113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 * | Cookie (optional, maximum 64 bits)... 115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116 * | 117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 * 119 * L2TPv3 Control Message Header Over IP 120 * 121 * 0 1 2 3 122 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 124 * | (32 bits of zeros) | 125 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 126 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 127 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 128 * | Control Connection ID | 129 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 130 * | Ns | Nr | 131 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 132 * 133 * All control frames are passed to userspace. 134 */ 135 static int l2tp_ip6_recv(struct sk_buff *skb) 136 { 137 struct net *net = dev_net(skb->dev); 138 struct l2tp_ip6_net *pn; 139 struct sock *sk; 140 u32 session_id; 141 u32 tunnel_id; 142 unsigned char *ptr, *optr; 143 struct l2tp_session *session; 144 struct l2tp_tunnel *tunnel = NULL; 145 struct ipv6hdr *iph; 146 147 pn = l2tp_ip6_pernet(net); 148 149 if (!pskb_may_pull(skb, 4)) 150 goto discard; 151 152 /* Point to L2TP header */ 153 optr = skb->data; 154 ptr = skb->data; 155 session_id = ntohl(*((__be32 *)ptr)); 156 ptr += 4; 157 158 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 159 * the session_id. If it is 0, the packet is a L2TP control 160 * frame and the session_id value can be discarded. 161 */ 162 if (session_id == 0) { 163 __skb_pull(skb, 4); 164 goto pass_up; 165 } 166 167 /* Ok, this is a data packet. Lookup the session. */ 168 session = l2tp_v3_session_get(net, NULL, session_id); 169 if (!session) 170 goto discard; 171 172 tunnel = session->tunnel; 173 if (!tunnel) 174 goto discard_sess; 175 176 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 177 goto discard_sess; 178 179 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 180 l2tp_session_put(session); 181 182 return 0; 183 184 pass_up: 185 /* Get the tunnel_id from the L2TP header */ 186 if (!pskb_may_pull(skb, 12)) 187 goto discard; 188 189 if ((skb->data[0] & 0xc0) != 0xc0) 190 goto discard; 191 192 tunnel_id = ntohl(*(__be32 *)&skb->data[4]); 193 iph = ipv6_hdr(skb); 194 195 read_lock_bh(&pn->l2tp_ip6_lock); 196 sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr, 197 inet6_iif(skb), tunnel_id); 198 if (!sk) { 199 read_unlock_bh(&pn->l2tp_ip6_lock); 200 goto discard; 201 } 202 sock_hold(sk); 203 read_unlock_bh(&pn->l2tp_ip6_lock); 204 205 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 206 goto discard_put; 207 208 nf_reset_ct(skb); 209 210 return sk_receive_skb(sk, skb, 1); 211 212 discard_sess: 213 l2tp_session_put(session); 214 goto discard; 215 216 discard_put: 217 sock_put(sk); 218 219 discard: 220 kfree_skb(skb); 221 return 0; 222 } 223 224 static int l2tp_ip6_hash(struct sock *sk) 225 { 226 struct l2tp_ip6_net *pn = l2tp_ip6_pernet(sock_net(sk)); 227 228 if (sk_unhashed(sk)) { 229 write_lock_bh(&pn->l2tp_ip6_lock); 230 sk_add_node(sk, &pn->l2tp_ip6_table); 231 write_unlock_bh(&pn->l2tp_ip6_lock); 232 } 233 return 0; 234 } 235 236 static void l2tp_ip6_unhash(struct sock *sk) 237 { 238 struct l2tp_ip6_net *pn = l2tp_ip6_pernet(sock_net(sk)); 239 240 if (sk_unhashed(sk)) 241 return; 242 write_lock_bh(&pn->l2tp_ip6_lock); 243 sk_del_node_init(sk); 244 write_unlock_bh(&pn->l2tp_ip6_lock); 245 } 246 247 static int l2tp_ip6_open(struct sock *sk) 248 { 249 /* Prevent autobind. We don't have ports. */ 250 inet_sk(sk)->inet_num = IPPROTO_L2TP; 251 252 l2tp_ip6_hash(sk); 253 return 0; 254 } 255 256 static void l2tp_ip6_close(struct sock *sk, long timeout) 257 { 258 struct l2tp_ip6_net *pn = l2tp_ip6_pernet(sock_net(sk)); 259 260 write_lock_bh(&pn->l2tp_ip6_lock); 261 hlist_del_init(&sk->sk_bind_node); 262 sk_del_node_init(sk); 263 write_unlock_bh(&pn->l2tp_ip6_lock); 264 265 sk_common_release(sk); 266 } 267 268 static void l2tp_ip6_destroy_sock(struct sock *sk) 269 { 270 struct l2tp_tunnel *tunnel; 271 272 lock_sock(sk); 273 ip6_flush_pending_frames(sk); 274 release_sock(sk); 275 276 tunnel = l2tp_sk_to_tunnel(sk); 277 if (tunnel) { 278 l2tp_tunnel_delete(tunnel); 279 l2tp_tunnel_put(tunnel); 280 } 281 } 282 283 static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 284 { 285 struct inet_sock *inet = inet_sk(sk); 286 struct ipv6_pinfo *np = inet6_sk(sk); 287 struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *)uaddr; 288 struct net *net = sock_net(sk); 289 struct l2tp_ip6_net *pn; 290 __be32 v4addr = 0; 291 int bound_dev_if; 292 int addr_type; 293 int err; 294 295 pn = l2tp_ip6_pernet(net); 296 297 if (addr->l2tp_family != AF_INET6) 298 return -EINVAL; 299 if (addr_len < sizeof(*addr)) 300 return -EINVAL; 301 302 addr_type = ipv6_addr_type(&addr->l2tp_addr); 303 304 /* l2tp_ip6 sockets are IPv6 only */ 305 if (addr_type == IPV6_ADDR_MAPPED) 306 return -EADDRNOTAVAIL; 307 308 /* L2TP is point-point, not multicast */ 309 if (addr_type & IPV6_ADDR_MULTICAST) 310 return -EADDRNOTAVAIL; 311 312 lock_sock(sk); 313 314 err = -EINVAL; 315 if (!sock_flag(sk, SOCK_ZAPPED)) 316 goto out_unlock; 317 318 if (sk->sk_state != TCP_CLOSE) 319 goto out_unlock; 320 321 bound_dev_if = sk->sk_bound_dev_if; 322 323 /* Check if the address belongs to the host. */ 324 rcu_read_lock(); 325 if (addr_type != IPV6_ADDR_ANY) { 326 struct net_device *dev = NULL; 327 328 if (addr_type & IPV6_ADDR_LINKLOCAL) { 329 if (addr->l2tp_scope_id) 330 bound_dev_if = addr->l2tp_scope_id; 331 332 /* Binding to link-local address requires an 333 * interface. 334 */ 335 if (!bound_dev_if) 336 goto out_unlock_rcu; 337 338 err = -ENODEV; 339 dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); 340 if (!dev) 341 goto out_unlock_rcu; 342 } 343 344 /* ipv4 addr of the socket is invalid. Only the 345 * unspecified and mapped address have a v4 equivalent. 346 */ 347 v4addr = LOOPBACK4_IPV6; 348 err = -EADDRNOTAVAIL; 349 if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) 350 goto out_unlock_rcu; 351 } 352 rcu_read_unlock(); 353 354 write_lock_bh(&pn->l2tp_ip6_lock); 355 if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if, 356 addr->l2tp_conn_id)) { 357 write_unlock_bh(&pn->l2tp_ip6_lock); 358 err = -EADDRINUSE; 359 goto out_unlock; 360 } 361 362 inet->inet_saddr = v4addr; 363 inet->inet_rcv_saddr = v4addr; 364 sk->sk_bound_dev_if = bound_dev_if; 365 sk->sk_v6_rcv_saddr = addr->l2tp_addr; 366 np->saddr = addr->l2tp_addr; 367 368 l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; 369 370 sk_add_bind_node(sk, &pn->l2tp_ip6_bind_table); 371 sk_del_node_init(sk); 372 write_unlock_bh(&pn->l2tp_ip6_lock); 373 374 sock_reset_flag(sk, SOCK_ZAPPED); 375 release_sock(sk); 376 return 0; 377 378 out_unlock_rcu: 379 rcu_read_unlock(); 380 out_unlock: 381 release_sock(sk); 382 383 return err; 384 } 385 386 static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, 387 int addr_len) 388 { 389 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 390 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 391 struct in6_addr *daddr; 392 int addr_type; 393 int rc; 394 struct l2tp_ip6_net *pn; 395 396 if (addr_len < sizeof(*lsa)) 397 return -EINVAL; 398 399 if (usin->sin6_family != AF_INET6) 400 return -EINVAL; 401 402 addr_type = ipv6_addr_type(&usin->sin6_addr); 403 if (addr_type & IPV6_ADDR_MULTICAST) 404 return -EINVAL; 405 406 if (addr_type & IPV6_ADDR_MAPPED) { 407 daddr = &usin->sin6_addr; 408 if (ipv4_is_multicast(daddr->s6_addr32[3])) 409 return -EINVAL; 410 } 411 412 lock_sock(sk); 413 414 /* Must bind first - autobinding does not work */ 415 if (sock_flag(sk, SOCK_ZAPPED)) { 416 rc = -EINVAL; 417 goto out_sk; 418 } 419 420 rc = __ip6_datagram_connect(sk, uaddr, addr_len); 421 if (rc < 0) 422 goto out_sk; 423 424 l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 425 426 pn = l2tp_ip6_pernet(sock_net(sk)); 427 write_lock_bh(&pn->l2tp_ip6_lock); 428 hlist_del_init(&sk->sk_bind_node); 429 sk_add_bind_node(sk, &pn->l2tp_ip6_bind_table); 430 write_unlock_bh(&pn->l2tp_ip6_lock); 431 432 out_sk: 433 release_sock(sk); 434 435 return rc; 436 } 437 438 static int l2tp_ip6_disconnect(struct sock *sk, int flags) 439 { 440 if (sock_flag(sk, SOCK_ZAPPED)) 441 return 0; 442 443 return __udp_disconnect(sk, flags); 444 } 445 446 static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, 447 int peer) 448 { 449 struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; 450 struct sock *sk = sock->sk; 451 struct ipv6_pinfo *np = inet6_sk(sk); 452 struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); 453 454 lsa->l2tp_family = AF_INET6; 455 lsa->l2tp_flowinfo = 0; 456 lsa->l2tp_scope_id = 0; 457 lsa->l2tp_unused = 0; 458 if (peer) { 459 if (!lsk->peer_conn_id) 460 return -ENOTCONN; 461 lsa->l2tp_conn_id = lsk->peer_conn_id; 462 lsa->l2tp_addr = sk->sk_v6_daddr; 463 if (inet6_test_bit(SNDFLOW, sk)) 464 lsa->l2tp_flowinfo = np->flow_label; 465 } else { 466 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 467 lsa->l2tp_addr = np->saddr; 468 else 469 lsa->l2tp_addr = sk->sk_v6_rcv_saddr; 470 471 lsa->l2tp_conn_id = lsk->conn_id; 472 } 473 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 474 lsa->l2tp_scope_id = READ_ONCE(sk->sk_bound_dev_if); 475 return sizeof(*lsa); 476 } 477 478 static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) 479 { 480 int rc; 481 482 /* Charge it to the socket, dropping if the queue is full. */ 483 rc = sock_queue_rcv_skb(sk, skb); 484 if (rc < 0) 485 goto drop; 486 487 return 0; 488 489 drop: 490 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 491 kfree_skb(skb); 492 return -1; 493 } 494 495 static int l2tp_ip6_push_pending_frames(struct sock *sk) 496 { 497 struct sk_buff *skb; 498 __be32 *transhdr = NULL; 499 int err = 0; 500 501 skb = skb_peek(&sk->sk_write_queue); 502 if (!skb) 503 goto out; 504 505 transhdr = (__be32 *)skb_transport_header(skb); 506 *transhdr = 0; 507 508 err = ip6_push_pending_frames(sk); 509 510 out: 511 return err; 512 } 513 514 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 515 * control frames. 516 */ 517 static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 518 { 519 struct ipv6_txoptions opt_space; 520 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 521 struct in6_addr *daddr, *final_p, final; 522 struct ipv6_pinfo *np = inet6_sk(sk); 523 struct ipv6_txoptions *opt_to_free = NULL; 524 struct ipv6_txoptions *opt = NULL; 525 struct ip6_flowlabel *flowlabel = NULL; 526 struct dst_entry *dst = NULL; 527 struct flowi6 fl6; 528 struct ipcm6_cookie ipc6; 529 int addr_len = msg->msg_namelen; 530 int transhdrlen = 4; /* zero session-id */ 531 int ulen; 532 int err; 533 534 /* Rough check on arithmetic overflow, 535 * better check is made in ip6_append_data(). 536 */ 537 if (len > INT_MAX - transhdrlen) 538 return -EMSGSIZE; 539 540 /* Mirror BSD error message compatibility */ 541 if (msg->msg_flags & MSG_OOB) 542 return -EOPNOTSUPP; 543 544 /* Get and verify the address */ 545 memset(&fl6, 0, sizeof(fl6)); 546 547 fl6.flowi6_mark = READ_ONCE(sk->sk_mark); 548 fl6.flowi6_uid = sk->sk_uid; 549 550 ipcm6_init(&ipc6); 551 552 if (lsa) { 553 if (addr_len < SIN6_LEN_RFC2133) 554 return -EINVAL; 555 556 if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) 557 return -EAFNOSUPPORT; 558 559 daddr = &lsa->l2tp_addr; 560 if (inet6_test_bit(SNDFLOW, sk)) { 561 fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; 562 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 563 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 564 if (IS_ERR(flowlabel)) 565 return -EINVAL; 566 } 567 } 568 569 /* Otherwise it will be difficult to maintain 570 * sk->sk_dst_cache. 571 */ 572 if (sk->sk_state == TCP_ESTABLISHED && 573 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 574 daddr = &sk->sk_v6_daddr; 575 576 if (addr_len >= sizeof(struct sockaddr_in6) && 577 lsa->l2tp_scope_id && 578 ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) 579 fl6.flowi6_oif = lsa->l2tp_scope_id; 580 } else { 581 if (sk->sk_state != TCP_ESTABLISHED) 582 return -EDESTADDRREQ; 583 584 daddr = &sk->sk_v6_daddr; 585 fl6.flowlabel = np->flow_label; 586 } 587 588 if (fl6.flowi6_oif == 0) 589 fl6.flowi6_oif = READ_ONCE(sk->sk_bound_dev_if); 590 591 if (msg->msg_controllen) { 592 opt = &opt_space; 593 memset(opt, 0, sizeof(struct ipv6_txoptions)); 594 opt->tot_len = sizeof(struct ipv6_txoptions); 595 ipc6.opt = opt; 596 597 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6); 598 if (err < 0) { 599 fl6_sock_release(flowlabel); 600 return err; 601 } 602 if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { 603 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 604 if (IS_ERR(flowlabel)) 605 return -EINVAL; 606 } 607 if (!(opt->opt_nflen | opt->opt_flen)) 608 opt = NULL; 609 } 610 611 if (!opt) { 612 opt = txopt_get(np); 613 opt_to_free = opt; 614 } 615 if (flowlabel) 616 opt = fl6_merge_options(&opt_space, flowlabel, opt); 617 opt = ipv6_fixup_options(&opt_space, opt); 618 ipc6.opt = opt; 619 620 fl6.flowi6_proto = sk->sk_protocol; 621 if (!ipv6_addr_any(daddr)) 622 fl6.daddr = *daddr; 623 else 624 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 625 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 626 fl6.saddr = np->saddr; 627 628 final_p = fl6_update_dst(&fl6, opt, &final); 629 630 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) 631 fl6.flowi6_oif = READ_ONCE(np->mcast_oif); 632 else if (!fl6.flowi6_oif) 633 fl6.flowi6_oif = READ_ONCE(np->ucast_oif); 634 635 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); 636 637 if (ipc6.tclass < 0) 638 ipc6.tclass = np->tclass; 639 640 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 641 642 dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); 643 if (IS_ERR(dst)) { 644 err = PTR_ERR(dst); 645 goto out; 646 } 647 648 if (ipc6.hlimit < 0) 649 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 650 651 if (ipc6.dontfrag < 0) 652 ipc6.dontfrag = inet6_test_bit(DONTFRAG, sk); 653 654 if (msg->msg_flags & MSG_CONFIRM) 655 goto do_confirm; 656 657 back_from_confirm: 658 lock_sock(sk); 659 ulen = len + (skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0); 660 err = ip6_append_data(sk, ip_generic_getfrag, msg, 661 ulen, transhdrlen, &ipc6, 662 &fl6, dst_rt6_info(dst), 663 msg->msg_flags); 664 if (err) 665 ip6_flush_pending_frames(sk); 666 else if (!(msg->msg_flags & MSG_MORE)) 667 err = l2tp_ip6_push_pending_frames(sk); 668 release_sock(sk); 669 done: 670 dst_release(dst); 671 out: 672 fl6_sock_release(flowlabel); 673 txopt_put(opt_to_free); 674 675 return err < 0 ? err : len; 676 677 do_confirm: 678 if (msg->msg_flags & MSG_PROBE) 679 dst_confirm_neigh(dst, &fl6.daddr); 680 if (!(msg->msg_flags & MSG_PROBE) || len) 681 goto back_from_confirm; 682 err = 0; 683 goto done; 684 } 685 686 static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 687 int flags, int *addr_len) 688 { 689 struct ipv6_pinfo *np = inet6_sk(sk); 690 DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); 691 size_t copied = 0; 692 int err = -EOPNOTSUPP; 693 struct sk_buff *skb; 694 695 if (flags & MSG_OOB) 696 goto out; 697 698 if (flags & MSG_ERRQUEUE) 699 return ipv6_recv_error(sk, msg, len, addr_len); 700 701 skb = skb_recv_datagram(sk, flags, &err); 702 if (!skb) 703 goto out; 704 705 copied = skb->len; 706 if (len < copied) { 707 msg->msg_flags |= MSG_TRUNC; 708 copied = len; 709 } 710 711 err = skb_copy_datagram_msg(skb, 0, msg, copied); 712 if (err) 713 goto done; 714 715 sock_recv_timestamp(msg, sk, skb); 716 717 /* Copy the address. */ 718 if (lsa) { 719 lsa->l2tp_family = AF_INET6; 720 lsa->l2tp_unused = 0; 721 lsa->l2tp_addr = ipv6_hdr(skb)->saddr; 722 lsa->l2tp_flowinfo = 0; 723 lsa->l2tp_scope_id = 0; 724 lsa->l2tp_conn_id = 0; 725 if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) 726 lsa->l2tp_scope_id = inet6_iif(skb); 727 *addr_len = sizeof(*lsa); 728 } 729 730 if (np->rxopt.all) 731 ip6_datagram_recv_ctl(sk, msg, skb); 732 733 if (flags & MSG_TRUNC) 734 copied = skb->len; 735 done: 736 skb_free_datagram(sk, skb); 737 out: 738 return err ? err : copied; 739 } 740 741 static struct proto l2tp_ip6_prot = { 742 .name = "L2TP/IPv6", 743 .owner = THIS_MODULE, 744 .init = l2tp_ip6_open, 745 .close = l2tp_ip6_close, 746 .bind = l2tp_ip6_bind, 747 .connect = l2tp_ip6_connect, 748 .disconnect = l2tp_ip6_disconnect, 749 .ioctl = l2tp_ioctl, 750 .destroy = l2tp_ip6_destroy_sock, 751 .setsockopt = ipv6_setsockopt, 752 .getsockopt = ipv6_getsockopt, 753 .sendmsg = l2tp_ip6_sendmsg, 754 .recvmsg = l2tp_ip6_recvmsg, 755 .backlog_rcv = l2tp_ip6_backlog_recv, 756 .hash = l2tp_ip6_hash, 757 .unhash = l2tp_ip6_unhash, 758 .obj_size = sizeof(struct l2tp_ip6_sock), 759 .ipv6_pinfo_offset = offsetof(struct l2tp_ip6_sock, inet6), 760 }; 761 762 static const struct proto_ops l2tp_ip6_ops = { 763 .family = PF_INET6, 764 .owner = THIS_MODULE, 765 .release = inet6_release, 766 .bind = inet6_bind, 767 .connect = inet_dgram_connect, 768 .socketpair = sock_no_socketpair, 769 .accept = sock_no_accept, 770 .getname = l2tp_ip6_getname, 771 .poll = datagram_poll, 772 .ioctl = inet6_ioctl, 773 .gettstamp = sock_gettstamp, 774 .listen = sock_no_listen, 775 .shutdown = inet_shutdown, 776 .setsockopt = sock_common_setsockopt, 777 .getsockopt = sock_common_getsockopt, 778 .sendmsg = inet_sendmsg, 779 .recvmsg = sock_common_recvmsg, 780 .mmap = sock_no_mmap, 781 #ifdef CONFIG_COMPAT 782 .compat_ioctl = inet6_compat_ioctl, 783 #endif 784 }; 785 786 static struct inet_protosw l2tp_ip6_protosw = { 787 .type = SOCK_DGRAM, 788 .protocol = IPPROTO_L2TP, 789 .prot = &l2tp_ip6_prot, 790 .ops = &l2tp_ip6_ops, 791 }; 792 793 static struct inet6_protocol l2tp_ip6_protocol __read_mostly = { 794 .handler = l2tp_ip6_recv, 795 }; 796 797 static __net_init int l2tp_ip6_init_net(struct net *net) 798 { 799 struct l2tp_ip6_net *pn = net_generic(net, l2tp_ip6_net_id); 800 801 rwlock_init(&pn->l2tp_ip6_lock); 802 INIT_HLIST_HEAD(&pn->l2tp_ip6_table); 803 INIT_HLIST_HEAD(&pn->l2tp_ip6_bind_table); 804 return 0; 805 } 806 807 static __net_exit void l2tp_ip6_exit_net(struct net *net) 808 { 809 struct l2tp_ip6_net *pn = l2tp_ip6_pernet(net); 810 811 write_lock_bh(&pn->l2tp_ip6_lock); 812 WARN_ON_ONCE(hlist_count_nodes(&pn->l2tp_ip6_table) != 0); 813 WARN_ON_ONCE(hlist_count_nodes(&pn->l2tp_ip6_bind_table) != 0); 814 write_unlock_bh(&pn->l2tp_ip6_lock); 815 } 816 817 static struct pernet_operations l2tp_ip6_net_ops = { 818 .init = l2tp_ip6_init_net, 819 .exit = l2tp_ip6_exit_net, 820 .id = &l2tp_ip6_net_id, 821 .size = sizeof(struct l2tp_ip6_net), 822 }; 823 824 static int __init l2tp_ip6_init(void) 825 { 826 int err; 827 828 pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n"); 829 830 err = register_pernet_device(&l2tp_ip6_net_ops); 831 if (err) 832 goto out; 833 834 err = proto_register(&l2tp_ip6_prot, 1); 835 if (err != 0) 836 goto out1; 837 838 err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 839 if (err) 840 goto out2; 841 842 inet6_register_protosw(&l2tp_ip6_protosw); 843 return 0; 844 845 out2: 846 proto_unregister(&l2tp_ip6_prot); 847 out1: 848 unregister_pernet_device(&l2tp_ip6_net_ops); 849 out: 850 return err; 851 } 852 853 static void __exit l2tp_ip6_exit(void) 854 { 855 inet6_unregister_protosw(&l2tp_ip6_protosw); 856 inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP); 857 proto_unregister(&l2tp_ip6_prot); 858 unregister_pernet_device(&l2tp_ip6_net_ops); 859 } 860 861 module_init(l2tp_ip6_init); 862 module_exit(l2tp_ip6_exit); 863 864 MODULE_LICENSE("GPL"); 865 MODULE_AUTHOR("Chris Elston <celston@katalix.com>"); 866 MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6"); 867 MODULE_VERSION("1.0"); 868 869 /* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, 870 * because __stringify doesn't like enums 871 */ 872 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 115, 2); 873 MODULE_ALIAS_NET_PF_PROTO(PF_INET6, 115); 874