1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* L2TPv3 IP encapsulation support 3 * 4 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #include <asm/ioctls.h> 10 #include <linux/icmp.h> 11 #include <linux/module.h> 12 #include <linux/skbuff.h> 13 #include <linux/random.h> 14 #include <linux/socket.h> 15 #include <linux/l2tp.h> 16 #include <linux/in.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 "l2tp_core.h" 29 30 /* per-net private data for this module */ 31 static unsigned int l2tp_ip_net_id; 32 struct l2tp_ip_net { 33 rwlock_t l2tp_ip_lock; 34 struct hlist_head l2tp_ip_table; 35 struct hlist_head l2tp_ip_bind_table; 36 }; 37 38 struct l2tp_ip_sock { 39 /* inet_sock has to be the first member of l2tp_ip_sock */ 40 struct inet_sock inet; 41 42 u32 conn_id; 43 u32 peer_conn_id; 44 }; 45 46 static struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) 47 { 48 return (struct l2tp_ip_sock *)sk; 49 } 50 51 static struct l2tp_ip_net *l2tp_ip_pernet(const struct net *net) 52 { 53 return net_generic(net, l2tp_ip_net_id); 54 } 55 56 static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr, 57 __be32 raddr, int dif, u32 tunnel_id) 58 { 59 struct l2tp_ip_net *pn = l2tp_ip_pernet(net); 60 struct sock *sk; 61 62 sk_for_each_bound(sk, &pn->l2tp_ip_bind_table) { 63 const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); 64 const struct inet_sock *inet = inet_sk(sk); 65 int bound_dev_if; 66 67 if (!net_eq(sock_net(sk), net)) 68 continue; 69 70 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 71 if (bound_dev_if && dif && bound_dev_if != dif) 72 continue; 73 74 if (inet->inet_rcv_saddr && laddr && 75 inet->inet_rcv_saddr != laddr) 76 continue; 77 78 if (inet->inet_daddr && raddr && inet->inet_daddr != raddr) 79 continue; 80 81 if (l2tp->conn_id != tunnel_id) 82 continue; 83 84 goto found; 85 } 86 87 sk = NULL; 88 found: 89 return sk; 90 } 91 92 /* When processing receive frames, there are two cases to 93 * consider. Data frames consist of a non-zero session-id and an 94 * optional cookie. Control frames consist of a regular L2TP header 95 * preceded by 32-bits of zeros. 96 * 97 * L2TPv3 Session Header Over IP 98 * 99 * 0 1 2 3 100 * 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 1 101 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 102 * | Session ID | 103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 104 * | Cookie (optional, maximum 64 bits)... 105 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 106 * | 107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 108 * 109 * L2TPv3 Control Message Header Over IP 110 * 111 * 0 1 2 3 112 * 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 1 113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 * | (32 bits of zeros) | 115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 * | Control Connection ID | 119 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 120 * | Ns | Nr | 121 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 122 * 123 * All control frames are passed to userspace. 124 */ 125 static int l2tp_ip_recv(struct sk_buff *skb) 126 { 127 struct net *net = dev_net(skb->dev); 128 struct l2tp_ip_net *pn; 129 struct sock *sk; 130 u32 session_id; 131 u32 tunnel_id; 132 unsigned char *ptr, *optr; 133 struct l2tp_session *session; 134 struct l2tp_tunnel *tunnel = NULL; 135 struct iphdr *iph; 136 137 pn = l2tp_ip_pernet(net); 138 139 if (!pskb_may_pull(skb, 4)) 140 goto discard; 141 142 /* Point to L2TP header */ 143 optr = skb->data; 144 ptr = skb->data; 145 session_id = ntohl(*((__be32 *)ptr)); 146 ptr += 4; 147 148 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 149 * the session_id. If it is 0, the packet is a L2TP control 150 * frame and the session_id value can be discarded. 151 */ 152 if (session_id == 0) { 153 __skb_pull(skb, 4); 154 goto pass_up; 155 } 156 157 /* Ok, this is a data packet. Lookup the session. */ 158 session = l2tp_v3_session_get(net, NULL, session_id); 159 if (!session) 160 goto discard; 161 162 tunnel = session->tunnel; 163 if (!tunnel) 164 goto discard_sess; 165 166 if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) 167 goto discard_sess; 168 169 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 170 l2tp_session_put(session); 171 172 return 0; 173 174 pass_up: 175 /* Get the tunnel_id from the L2TP header */ 176 if (!pskb_may_pull(skb, 12)) 177 goto discard; 178 179 if ((skb->data[0] & 0xc0) != 0xc0) 180 goto discard; 181 182 tunnel_id = ntohl(*(__be32 *)&skb->data[4]); 183 iph = (struct iphdr *)skb_network_header(skb); 184 185 read_lock_bh(&pn->l2tp_ip_lock); 186 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr, inet_iif(skb), 187 tunnel_id); 188 if (!sk) { 189 read_unlock_bh(&pn->l2tp_ip_lock); 190 goto discard; 191 } 192 sock_hold(sk); 193 read_unlock_bh(&pn->l2tp_ip_lock); 194 195 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 196 goto discard_put; 197 198 nf_reset_ct(skb); 199 200 return sk_receive_skb(sk, skb, 1); 201 202 discard_sess: 203 l2tp_session_put(session); 204 goto discard; 205 206 discard_put: 207 sock_put(sk); 208 209 discard: 210 kfree_skb(skb); 211 return 0; 212 } 213 214 static int l2tp_ip_hash(struct sock *sk) 215 { 216 struct l2tp_ip_net *pn = l2tp_ip_pernet(sock_net(sk)); 217 218 if (sk_unhashed(sk)) { 219 write_lock_bh(&pn->l2tp_ip_lock); 220 sk_add_node(sk, &pn->l2tp_ip_table); 221 write_unlock_bh(&pn->l2tp_ip_lock); 222 } 223 return 0; 224 } 225 226 static void l2tp_ip_unhash(struct sock *sk) 227 { 228 struct l2tp_ip_net *pn = l2tp_ip_pernet(sock_net(sk)); 229 230 if (sk_unhashed(sk)) 231 return; 232 write_lock_bh(&pn->l2tp_ip_lock); 233 sk_del_node_init(sk); 234 write_unlock_bh(&pn->l2tp_ip_lock); 235 } 236 237 static int l2tp_ip_open(struct sock *sk) 238 { 239 /* Prevent autobind. We don't have ports. */ 240 inet_sk(sk)->inet_num = IPPROTO_L2TP; 241 242 l2tp_ip_hash(sk); 243 return 0; 244 } 245 246 static void l2tp_ip_close(struct sock *sk, long timeout) 247 { 248 struct l2tp_ip_net *pn = l2tp_ip_pernet(sock_net(sk)); 249 250 write_lock_bh(&pn->l2tp_ip_lock); 251 hlist_del_init(&sk->sk_bind_node); 252 sk_del_node_init(sk); 253 write_unlock_bh(&pn->l2tp_ip_lock); 254 sk_common_release(sk); 255 } 256 257 static void l2tp_ip_destroy_sock(struct sock *sk) 258 { 259 struct l2tp_tunnel *tunnel; 260 261 __skb_queue_purge(&sk->sk_write_queue); 262 263 tunnel = l2tp_sk_to_tunnel(sk); 264 if (tunnel) { 265 l2tp_tunnel_delete(tunnel); 266 l2tp_tunnel_put(tunnel); 267 } 268 } 269 270 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 271 { 272 struct inet_sock *inet = inet_sk(sk); 273 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *)uaddr; 274 struct net *net = sock_net(sk); 275 struct l2tp_ip_net *pn; 276 int ret; 277 int chk_addr_ret; 278 279 if (addr_len < sizeof(struct sockaddr_l2tpip)) 280 return -EINVAL; 281 if (addr->l2tp_family != AF_INET) 282 return -EINVAL; 283 284 lock_sock(sk); 285 286 ret = -EINVAL; 287 if (!sock_flag(sk, SOCK_ZAPPED)) 288 goto out; 289 290 if (sk->sk_state != TCP_CLOSE) 291 goto out; 292 293 chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr); 294 ret = -EADDRNOTAVAIL; 295 if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && 296 chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) 297 goto out; 298 299 if (addr->l2tp_addr.s_addr) { 300 inet->inet_rcv_saddr = addr->l2tp_addr.s_addr; 301 inet->inet_saddr = addr->l2tp_addr.s_addr; 302 } 303 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) 304 inet->inet_saddr = 0; /* Use device */ 305 306 pn = l2tp_ip_pernet(net); 307 write_lock_bh(&pn->l2tp_ip_lock); 308 if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0, 309 sk->sk_bound_dev_if, addr->l2tp_conn_id)) { 310 write_unlock_bh(&pn->l2tp_ip_lock); 311 ret = -EADDRINUSE; 312 goto out; 313 } 314 315 sk_dst_reset(sk); 316 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; 317 318 sk_add_bind_node(sk, &pn->l2tp_ip_bind_table); 319 sk_del_node_init(sk); 320 write_unlock_bh(&pn->l2tp_ip_lock); 321 322 ret = 0; 323 sock_reset_flag(sk, SOCK_ZAPPED); 324 325 out: 326 release_sock(sk); 327 328 return ret; 329 } 330 331 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 332 { 333 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; 334 struct l2tp_ip_net *pn = l2tp_ip_pernet(sock_net(sk)); 335 int rc; 336 337 if (addr_len < sizeof(*lsa)) 338 return -EINVAL; 339 340 if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) 341 return -EINVAL; 342 343 lock_sock(sk); 344 345 /* Must bind first - autobinding does not work */ 346 if (sock_flag(sk, SOCK_ZAPPED)) { 347 rc = -EINVAL; 348 goto out_sk; 349 } 350 351 rc = __ip4_datagram_connect(sk, uaddr, addr_len); 352 if (rc < 0) 353 goto out_sk; 354 355 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 356 357 write_lock_bh(&pn->l2tp_ip_lock); 358 hlist_del_init(&sk->sk_bind_node); 359 sk_add_bind_node(sk, &pn->l2tp_ip_bind_table); 360 write_unlock_bh(&pn->l2tp_ip_lock); 361 362 out_sk: 363 release_sock(sk); 364 365 return rc; 366 } 367 368 static int l2tp_ip_disconnect(struct sock *sk, int flags) 369 { 370 if (sock_flag(sk, SOCK_ZAPPED)) 371 return 0; 372 373 return __udp_disconnect(sk, flags); 374 } 375 376 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, 377 int peer) 378 { 379 struct sock *sk = sock->sk; 380 struct inet_sock *inet = inet_sk(sk); 381 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); 382 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; 383 384 memset(lsa, 0, sizeof(*lsa)); 385 lsa->l2tp_family = AF_INET; 386 if (peer) { 387 if (!inet->inet_dport) 388 return -ENOTCONN; 389 lsa->l2tp_conn_id = lsk->peer_conn_id; 390 lsa->l2tp_addr.s_addr = inet->inet_daddr; 391 } else { 392 __be32 addr = inet->inet_rcv_saddr; 393 394 if (!addr) 395 addr = inet->inet_saddr; 396 lsa->l2tp_conn_id = lsk->conn_id; 397 lsa->l2tp_addr.s_addr = addr; 398 } 399 return sizeof(*lsa); 400 } 401 402 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) 403 { 404 int rc; 405 406 /* Charge it to the socket, dropping if the queue is full. */ 407 rc = sock_queue_rcv_skb(sk, skb); 408 if (rc < 0) 409 goto drop; 410 411 return 0; 412 413 drop: 414 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 415 kfree_skb(skb); 416 return 0; 417 } 418 419 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 420 * control frames. 421 */ 422 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 423 { 424 struct sk_buff *skb; 425 int rc; 426 struct inet_sock *inet = inet_sk(sk); 427 struct rtable *rt = NULL; 428 int connected = 0; 429 __be32 daddr; 430 431 lock_sock(sk); 432 433 rc = -ENOTCONN; 434 if (sock_flag(sk, SOCK_DEAD)) 435 goto out; 436 437 /* Get and verify the address. */ 438 if (msg->msg_name) { 439 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name); 440 441 rc = -EINVAL; 442 if (msg->msg_namelen < sizeof(*lip)) 443 goto out; 444 445 if (lip->l2tp_family != AF_INET) { 446 rc = -EAFNOSUPPORT; 447 if (lip->l2tp_family != AF_UNSPEC) 448 goto out; 449 } 450 451 daddr = lip->l2tp_addr.s_addr; 452 } else { 453 rc = -EDESTADDRREQ; 454 if (sk->sk_state != TCP_ESTABLISHED) 455 goto out; 456 457 connected = 1; 458 } 459 460 /* Allocate a socket buffer */ 461 rc = -ENOMEM; 462 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + 463 4 + len, 0, GFP_KERNEL); 464 if (!skb) 465 goto error; 466 467 /* Reserve space for headers, putting IP header on 4-byte boundary. */ 468 skb_reserve(skb, 2 + NET_SKB_PAD); 469 skb_reset_network_header(skb); 470 skb_reserve(skb, sizeof(struct iphdr)); 471 skb_reset_transport_header(skb); 472 473 /* Insert 0 session_id */ 474 *((__be32 *)skb_put(skb, 4)) = 0; 475 476 /* Copy user data into skb */ 477 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 478 if (rc < 0) { 479 kfree_skb(skb); 480 goto error; 481 } 482 483 if (connected) 484 rt = dst_rtable(__sk_dst_check(sk, 0)); 485 486 rcu_read_lock(); 487 if (!rt) { 488 struct flowi4 *fl4 = &inet->cork.fl.u.ip4; 489 490 inet_sk_init_flowi4(inet, fl4); 491 492 /* Overwrite ->daddr if msg->msg_name was provided */ 493 if (!connected) 494 fl4->daddr = daddr; 495 496 /* If this fails, retransmit mechanism of transport layer will 497 * keep trying until route appears or the connection times 498 * itself out. 499 */ 500 rt = ip_route_output_flow(sock_net(sk), fl4, sk); 501 if (IS_ERR(rt)) 502 goto no_route; 503 if (connected) { 504 sk_setup_caps(sk, &rt->dst); 505 } else { 506 skb_dst_set(skb, &rt->dst); 507 goto xmit; 508 } 509 } 510 511 /* We don't need to clone dst here, it is guaranteed to not disappear. 512 * __dev_xmit_skb() might force a refcount if needed. 513 */ 514 skb_dst_set_noref(skb, &rt->dst); 515 516 xmit: 517 /* Queue the packet to IP for output */ 518 rc = ip_queue_xmit(sk, skb, &inet->cork.fl); 519 rcu_read_unlock(); 520 521 error: 522 if (rc >= 0) 523 rc = len; 524 525 out: 526 release_sock(sk); 527 return rc; 528 529 no_route: 530 rcu_read_unlock(); 531 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 532 kfree_skb(skb); 533 rc = -EHOSTUNREACH; 534 goto out; 535 } 536 537 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg, 538 size_t len, int flags, int *addr_len) 539 { 540 struct inet_sock *inet = inet_sk(sk); 541 size_t copied = 0; 542 int err = -EOPNOTSUPP; 543 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 544 struct sk_buff *skb; 545 546 if (flags & MSG_OOB) 547 goto out; 548 549 skb = skb_recv_datagram(sk, flags, &err); 550 if (!skb) 551 goto out; 552 553 copied = skb->len; 554 if (len < copied) { 555 msg->msg_flags |= MSG_TRUNC; 556 copied = len; 557 } 558 559 err = skb_copy_datagram_msg(skb, 0, msg, copied); 560 if (err) 561 goto done; 562 563 sock_recv_timestamp(msg, sk, skb); 564 565 /* Copy the address. */ 566 if (sin) { 567 sin->sin_family = AF_INET; 568 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 569 sin->sin_port = 0; 570 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); 571 *addr_len = sizeof(*sin); 572 } 573 if (inet_cmsg_flags(inet)) 574 ip_cmsg_recv(msg, skb); 575 if (flags & MSG_TRUNC) 576 copied = skb->len; 577 done: 578 skb_free_datagram(sk, skb); 579 out: 580 return err ? err : copied; 581 } 582 583 int l2tp_ioctl(struct sock *sk, int cmd, int *karg) 584 { 585 struct sk_buff *skb; 586 587 switch (cmd) { 588 case SIOCOUTQ: 589 *karg = sk_wmem_alloc_get(sk); 590 break; 591 case SIOCINQ: 592 spin_lock_bh(&sk->sk_receive_queue.lock); 593 skb = skb_peek(&sk->sk_receive_queue); 594 *karg = skb ? skb->len : 0; 595 spin_unlock_bh(&sk->sk_receive_queue.lock); 596 break; 597 598 default: 599 return -ENOIOCTLCMD; 600 } 601 602 return 0; 603 } 604 EXPORT_SYMBOL_GPL(l2tp_ioctl); 605 606 static struct proto l2tp_ip_prot = { 607 .name = "L2TP/IP", 608 .owner = THIS_MODULE, 609 .init = l2tp_ip_open, 610 .close = l2tp_ip_close, 611 .bind = l2tp_ip_bind, 612 .connect = l2tp_ip_connect, 613 .disconnect = l2tp_ip_disconnect, 614 .ioctl = l2tp_ioctl, 615 .destroy = l2tp_ip_destroy_sock, 616 .setsockopt = ip_setsockopt, 617 .getsockopt = ip_getsockopt, 618 .sendmsg = l2tp_ip_sendmsg, 619 .recvmsg = l2tp_ip_recvmsg, 620 .backlog_rcv = l2tp_ip_backlog_recv, 621 .hash = l2tp_ip_hash, 622 .unhash = l2tp_ip_unhash, 623 .obj_size = sizeof(struct l2tp_ip_sock), 624 }; 625 626 static const struct proto_ops l2tp_ip_ops = { 627 .family = PF_INET, 628 .owner = THIS_MODULE, 629 .release = inet_release, 630 .bind = inet_bind, 631 .connect = inet_dgram_connect, 632 .socketpair = sock_no_socketpair, 633 .accept = sock_no_accept, 634 .getname = l2tp_ip_getname, 635 .poll = datagram_poll, 636 .ioctl = inet_ioctl, 637 .gettstamp = sock_gettstamp, 638 .listen = sock_no_listen, 639 .shutdown = inet_shutdown, 640 .setsockopt = sock_common_setsockopt, 641 .getsockopt = sock_common_getsockopt, 642 .sendmsg = inet_sendmsg, 643 .recvmsg = sock_common_recvmsg, 644 .mmap = sock_no_mmap, 645 }; 646 647 static struct inet_protosw l2tp_ip_protosw = { 648 .type = SOCK_DGRAM, 649 .protocol = IPPROTO_L2TP, 650 .prot = &l2tp_ip_prot, 651 .ops = &l2tp_ip_ops, 652 }; 653 654 static struct net_protocol l2tp_ip_protocol __read_mostly = { 655 .handler = l2tp_ip_recv, 656 }; 657 658 static __net_init int l2tp_ip_init_net(struct net *net) 659 { 660 struct l2tp_ip_net *pn = net_generic(net, l2tp_ip_net_id); 661 662 rwlock_init(&pn->l2tp_ip_lock); 663 INIT_HLIST_HEAD(&pn->l2tp_ip_table); 664 INIT_HLIST_HEAD(&pn->l2tp_ip_bind_table); 665 return 0; 666 } 667 668 static __net_exit void l2tp_ip_exit_net(struct net *net) 669 { 670 struct l2tp_ip_net *pn = l2tp_ip_pernet(net); 671 672 write_lock_bh(&pn->l2tp_ip_lock); 673 WARN_ON_ONCE(hlist_count_nodes(&pn->l2tp_ip_table) != 0); 674 WARN_ON_ONCE(hlist_count_nodes(&pn->l2tp_ip_bind_table) != 0); 675 write_unlock_bh(&pn->l2tp_ip_lock); 676 } 677 678 static struct pernet_operations l2tp_ip_net_ops = { 679 .init = l2tp_ip_init_net, 680 .exit = l2tp_ip_exit_net, 681 .id = &l2tp_ip_net_id, 682 .size = sizeof(struct l2tp_ip_net), 683 }; 684 685 static int __init l2tp_ip_init(void) 686 { 687 int err; 688 689 pr_info("L2TP IP encapsulation support (L2TPv3)\n"); 690 691 err = register_pernet_device(&l2tp_ip_net_ops); 692 if (err) 693 goto out; 694 695 err = proto_register(&l2tp_ip_prot, 1); 696 if (err != 0) 697 goto out1; 698 699 err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 700 if (err) 701 goto out2; 702 703 inet_register_protosw(&l2tp_ip_protosw); 704 return 0; 705 706 out2: 707 proto_unregister(&l2tp_ip_prot); 708 out1: 709 unregister_pernet_device(&l2tp_ip_net_ops); 710 out: 711 return err; 712 } 713 714 static void __exit l2tp_ip_exit(void) 715 { 716 inet_unregister_protosw(&l2tp_ip_protosw); 717 inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 718 proto_unregister(&l2tp_ip_prot); 719 unregister_pernet_device(&l2tp_ip_net_ops); 720 } 721 722 module_init(l2tp_ip_init); 723 module_exit(l2tp_ip_exit); 724 725 MODULE_LICENSE("GPL"); 726 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 727 MODULE_DESCRIPTION("L2TP over IP"); 728 MODULE_VERSION("1.0"); 729 730 /* Use the values of SOCK_DGRAM (2) as type and IPPROTO_L2TP (115) as protocol, 731 * because __stringify doesn't like enums 732 */ 733 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 115, 2); 734 MODULE_ALIAS_NET_PF_PROTO(PF_INET, 115); 735