1 /* 2 * L2TPv3 IP encapsulation support 3 * 4 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/icmp.h> 13 #include <linux/module.h> 14 #include <linux/skbuff.h> 15 #include <linux/random.h> 16 #include <linux/socket.h> 17 #include <linux/l2tp.h> 18 #include <linux/in.h> 19 #include <net/sock.h> 20 #include <net/ip.h> 21 #include <net/icmp.h> 22 #include <net/udp.h> 23 #include <net/inet_common.h> 24 #include <net/inet_hashtables.h> 25 #include <net/tcp_states.h> 26 #include <net/protocol.h> 27 #include <net/xfrm.h> 28 29 #include "l2tp_core.h" 30 31 struct l2tp_ip_sock { 32 /* inet_sock has to be the first member of l2tp_ip_sock */ 33 struct inet_sock inet; 34 35 __u32 conn_id; 36 __u32 peer_conn_id; 37 38 __u64 tx_packets; 39 __u64 tx_bytes; 40 __u64 tx_errors; 41 __u64 rx_packets; 42 __u64 rx_bytes; 43 __u64 rx_errors; 44 }; 45 46 static DEFINE_RWLOCK(l2tp_ip_lock); 47 static struct hlist_head l2tp_ip_table; 48 static struct hlist_head l2tp_ip_bind_table; 49 50 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) 51 { 52 return (struct l2tp_ip_sock *)sk; 53 } 54 55 static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) 56 { 57 struct hlist_node *node; 58 struct sock *sk; 59 60 sk_for_each_bound(sk, node, &l2tp_ip_bind_table) { 61 struct inet_sock *inet = inet_sk(sk); 62 struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); 63 64 if (l2tp == NULL) 65 continue; 66 67 if ((l2tp->conn_id == tunnel_id) && 68 net_eq(sock_net(sk), net) && 69 !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) && 70 !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) 71 goto found; 72 } 73 74 sk = NULL; 75 found: 76 return sk; 77 } 78 79 static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) 80 { 81 struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id); 82 if (sk) 83 sock_hold(sk); 84 85 return sk; 86 } 87 88 /* When processing receive frames, there are two cases to 89 * consider. Data frames consist of a non-zero session-id and an 90 * optional cookie. Control frames consist of a regular L2TP header 91 * preceded by 32-bits of zeros. 92 * 93 * L2TPv3 Session Header Over IP 94 * 95 * 0 1 2 3 96 * 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 97 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 98 * | Session ID | 99 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 100 * | Cookie (optional, maximum 64 bits)... 101 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 102 * | 103 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 104 * 105 * L2TPv3 Control Message Header Over IP 106 * 107 * 0 1 2 3 108 * 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 1 109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 110 * | (32 bits of zeros) | 111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 * | Control Connection ID | 115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 116 * | Ns | Nr | 117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 118 * 119 * All control frames are passed to userspace. 120 */ 121 static int l2tp_ip_recv(struct sk_buff *skb) 122 { 123 struct sock *sk; 124 u32 session_id; 125 u32 tunnel_id; 126 unsigned char *ptr, *optr; 127 struct l2tp_session *session; 128 struct l2tp_tunnel *tunnel = NULL; 129 int length; 130 int offset; 131 132 /* Point to L2TP header */ 133 optr = ptr = skb->data; 134 135 if (!pskb_may_pull(skb, 4)) 136 goto discard; 137 138 session_id = ntohl(*((__be32 *) ptr)); 139 ptr += 4; 140 141 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 142 * the session_id. If it is 0, the packet is a L2TP control 143 * frame and the session_id value can be discarded. 144 */ 145 if (session_id == 0) { 146 __skb_pull(skb, 4); 147 goto pass_up; 148 } 149 150 /* Ok, this is a data packet. Lookup the session. */ 151 session = l2tp_session_find(&init_net, NULL, session_id); 152 if (session == NULL) 153 goto discard; 154 155 tunnel = session->tunnel; 156 if (tunnel == NULL) 157 goto discard; 158 159 /* Trace packet contents, if enabled */ 160 if (tunnel->debug & L2TP_MSG_DATA) { 161 length = min(32u, skb->len); 162 if (!pskb_may_pull(skb, length)) 163 goto discard; 164 165 printk(KERN_DEBUG "%s: ip recv: ", tunnel->name); 166 167 offset = 0; 168 do { 169 printk(" %02X", ptr[offset]); 170 } while (++offset < length); 171 172 printk("\n"); 173 } 174 175 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); 176 177 return 0; 178 179 pass_up: 180 /* Get the tunnel_id from the L2TP header */ 181 if (!pskb_may_pull(skb, 12)) 182 goto discard; 183 184 if ((skb->data[0] & 0xc0) != 0xc0) 185 goto discard; 186 187 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 188 tunnel = l2tp_tunnel_find(&init_net, tunnel_id); 189 if (tunnel != NULL) 190 sk = tunnel->sock; 191 else { 192 struct iphdr *iph = (struct iphdr *) skb_network_header(skb); 193 194 read_lock_bh(&l2tp_ip_lock); 195 sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id); 196 read_unlock_bh(&l2tp_ip_lock); 197 } 198 199 if (sk == NULL) 200 goto discard; 201 202 sock_hold(sk); 203 204 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 205 goto discard_put; 206 207 nf_reset(skb); 208 209 return sk_receive_skb(sk, skb, 1); 210 211 discard_put: 212 sock_put(sk); 213 214 discard: 215 kfree_skb(skb); 216 return 0; 217 } 218 219 static int l2tp_ip_open(struct sock *sk) 220 { 221 /* Prevent autobind. We don't have ports. */ 222 inet_sk(sk)->inet_num = IPPROTO_L2TP; 223 224 write_lock_bh(&l2tp_ip_lock); 225 sk_add_node(sk, &l2tp_ip_table); 226 write_unlock_bh(&l2tp_ip_lock); 227 228 return 0; 229 } 230 231 static void l2tp_ip_close(struct sock *sk, long timeout) 232 { 233 write_lock_bh(&l2tp_ip_lock); 234 hlist_del_init(&sk->sk_bind_node); 235 hlist_del_init(&sk->sk_node); 236 write_unlock_bh(&l2tp_ip_lock); 237 sk_common_release(sk); 238 } 239 240 static void l2tp_ip_destroy_sock(struct sock *sk) 241 { 242 struct sk_buff *skb; 243 244 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 245 kfree_skb(skb); 246 247 sk_refcnt_debug_dec(sk); 248 } 249 250 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 251 { 252 struct inet_sock *inet = inet_sk(sk); 253 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr; 254 int ret = -EINVAL; 255 int chk_addr_ret; 256 257 ret = -EADDRINUSE; 258 read_lock_bh(&l2tp_ip_lock); 259 if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id)) 260 goto out_in_use; 261 262 read_unlock_bh(&l2tp_ip_lock); 263 264 lock_sock(sk); 265 if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip)) 266 goto out; 267 268 chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr); 269 ret = -EADDRNOTAVAIL; 270 if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && 271 chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) 272 goto out; 273 274 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; 275 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) 276 inet->inet_saddr = 0; /* Use device */ 277 sk_dst_reset(sk); 278 279 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; 280 281 write_lock_bh(&l2tp_ip_lock); 282 sk_add_bind_node(sk, &l2tp_ip_bind_table); 283 sk_del_node_init(sk); 284 write_unlock_bh(&l2tp_ip_lock); 285 ret = 0; 286 out: 287 release_sock(sk); 288 289 return ret; 290 291 out_in_use: 292 read_unlock_bh(&l2tp_ip_lock); 293 294 return ret; 295 } 296 297 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 298 { 299 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; 300 struct inet_sock *inet = inet_sk(sk); 301 struct flowi4 *fl4; 302 struct rtable *rt; 303 __be32 saddr; 304 int oif, rc; 305 306 rc = -EINVAL; 307 if (addr_len < sizeof(*lsa)) 308 goto out; 309 310 rc = -EAFNOSUPPORT; 311 if (lsa->l2tp_family != AF_INET) 312 goto out; 313 314 lock_sock(sk); 315 316 sk_dst_reset(sk); 317 318 oif = sk->sk_bound_dev_if; 319 saddr = inet->inet_saddr; 320 321 rc = -EINVAL; 322 if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) 323 goto out; 324 325 fl4 = &inet->cork.fl.u.ip4; 326 rt = ip_route_connect(fl4, lsa->l2tp_addr.s_addr, saddr, 327 RT_CONN_FLAGS(sk), oif, 328 IPPROTO_L2TP, 329 0, 0, sk, true); 330 if (IS_ERR(rt)) { 331 rc = PTR_ERR(rt); 332 if (rc == -ENETUNREACH) 333 IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES); 334 goto out; 335 } 336 337 rc = -ENETUNREACH; 338 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { 339 ip_rt_put(rt); 340 goto out; 341 } 342 343 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 344 345 if (!inet->inet_saddr) 346 inet->inet_saddr = fl4->saddr; 347 if (!inet->inet_rcv_saddr) 348 inet->inet_rcv_saddr = fl4->saddr; 349 inet->inet_daddr = fl4->daddr; 350 sk->sk_state = TCP_ESTABLISHED; 351 inet->inet_id = jiffies; 352 353 sk_dst_set(sk, &rt->dst); 354 355 write_lock_bh(&l2tp_ip_lock); 356 hlist_del_init(&sk->sk_bind_node); 357 sk_add_bind_node(sk, &l2tp_ip_bind_table); 358 write_unlock_bh(&l2tp_ip_lock); 359 360 rc = 0; 361 out: 362 release_sock(sk); 363 return rc; 364 } 365 366 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, 367 int *uaddr_len, int peer) 368 { 369 struct sock *sk = sock->sk; 370 struct inet_sock *inet = inet_sk(sk); 371 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); 372 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; 373 374 memset(lsa, 0, sizeof(*lsa)); 375 lsa->l2tp_family = AF_INET; 376 if (peer) { 377 if (!inet->inet_dport) 378 return -ENOTCONN; 379 lsa->l2tp_conn_id = lsk->peer_conn_id; 380 lsa->l2tp_addr.s_addr = inet->inet_daddr; 381 } else { 382 __be32 addr = inet->inet_rcv_saddr; 383 if (!addr) 384 addr = inet->inet_saddr; 385 lsa->l2tp_conn_id = lsk->conn_id; 386 lsa->l2tp_addr.s_addr = addr; 387 } 388 *uaddr_len = sizeof(*lsa); 389 return 0; 390 } 391 392 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) 393 { 394 int rc; 395 396 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 397 goto drop; 398 399 nf_reset(skb); 400 401 /* Charge it to the socket, dropping if the queue is full. */ 402 rc = sock_queue_rcv_skb(sk, skb); 403 if (rc < 0) 404 goto drop; 405 406 return 0; 407 408 drop: 409 IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); 410 kfree_skb(skb); 411 return -1; 412 } 413 414 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 415 * control frames. 416 */ 417 static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len) 418 { 419 struct sk_buff *skb; 420 int rc; 421 struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk); 422 struct inet_sock *inet = inet_sk(sk); 423 struct rtable *rt = NULL; 424 struct flowi4 *fl4; 425 int connected = 0; 426 __be32 daddr; 427 428 lock_sock(sk); 429 430 rc = -ENOTCONN; 431 if (sock_flag(sk, SOCK_DEAD)) 432 goto out; 433 434 /* Get and verify the address. */ 435 if (msg->msg_name) { 436 struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name; 437 rc = -EINVAL; 438 if (msg->msg_namelen < sizeof(*lip)) 439 goto out; 440 441 if (lip->l2tp_family != AF_INET) { 442 rc = -EAFNOSUPPORT; 443 if (lip->l2tp_family != AF_UNSPEC) 444 goto out; 445 } 446 447 daddr = lip->l2tp_addr.s_addr; 448 } else { 449 if (sk->sk_state != TCP_ESTABLISHED) 450 return -EDESTADDRREQ; 451 452 daddr = inet->inet_daddr; 453 connected = 1; 454 } 455 456 /* Allocate a socket buffer */ 457 rc = -ENOMEM; 458 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + 459 4 + len, 0, GFP_KERNEL); 460 if (!skb) 461 goto error; 462 463 /* Reserve space for headers, putting IP header on 4-byte boundary. */ 464 skb_reserve(skb, 2 + NET_SKB_PAD); 465 skb_reset_network_header(skb); 466 skb_reserve(skb, sizeof(struct iphdr)); 467 skb_reset_transport_header(skb); 468 469 /* Insert 0 session_id */ 470 *((__be32 *) skb_put(skb, 4)) = 0; 471 472 /* Copy user data into skb */ 473 rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 474 if (rc < 0) { 475 kfree_skb(skb); 476 goto error; 477 } 478 479 fl4 = &inet->cork.fl.u.ip4; 480 if (connected) 481 rt = (struct rtable *) __sk_dst_check(sk, 0); 482 483 if (rt == NULL) { 484 struct ip_options_rcu *inet_opt; 485 486 rcu_read_lock(); 487 inet_opt = rcu_dereference(inet->inet_opt); 488 489 /* Use correct destination address if we have options. */ 490 if (inet_opt && inet_opt->opt.srr) 491 daddr = inet_opt->opt.faddr; 492 493 rcu_read_unlock(); 494 495 /* If this fails, retransmit mechanism of transport layer will 496 * keep trying until route appears or the connection times 497 * itself out. 498 */ 499 rt = ip_route_output_ports(sock_net(sk), fl4, sk, 500 daddr, inet->inet_saddr, 501 inet->inet_dport, inet->inet_sport, 502 sk->sk_protocol, RT_CONN_FLAGS(sk), 503 sk->sk_bound_dev_if); 504 if (IS_ERR(rt)) 505 goto no_route; 506 sk_setup_caps(sk, &rt->dst); 507 } 508 skb_dst_set(skb, dst_clone(&rt->dst)); 509 510 /* Queue the packet to IP for output */ 511 rc = ip_queue_xmit(skb, &inet->cork.fl); 512 513 error: 514 /* Update stats */ 515 if (rc >= 0) { 516 lsa->tx_packets++; 517 lsa->tx_bytes += len; 518 rc = len; 519 } else { 520 lsa->tx_errors++; 521 } 522 523 out: 524 release_sock(sk); 525 return rc; 526 527 no_route: 528 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 529 kfree_skb(skb); 530 rc = -EHOSTUNREACH; 531 goto out; 532 } 533 534 static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 535 size_t len, int noblock, int flags, int *addr_len) 536 { 537 struct inet_sock *inet = inet_sk(sk); 538 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); 539 size_t copied = 0; 540 int err = -EOPNOTSUPP; 541 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 542 struct sk_buff *skb; 543 544 if (flags & MSG_OOB) 545 goto out; 546 547 if (addr_len) 548 *addr_len = sizeof(*sin); 549 550 skb = skb_recv_datagram(sk, flags, noblock, &err); 551 if (!skb) 552 goto out; 553 554 copied = skb->len; 555 if (len < copied) { 556 msg->msg_flags |= MSG_TRUNC; 557 copied = len; 558 } 559 560 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 561 if (err) 562 goto done; 563 564 sock_recv_timestamp(msg, sk, skb); 565 566 /* Copy the address. */ 567 if (sin) { 568 sin->sin_family = AF_INET; 569 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 570 sin->sin_port = 0; 571 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); 572 } 573 if (inet->cmsg_flags) 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 if (err) { 581 lsk->rx_errors++; 582 return err; 583 } 584 585 lsk->rx_packets++; 586 lsk->rx_bytes += copied; 587 588 return copied; 589 } 590 591 static struct proto l2tp_ip_prot = { 592 .name = "L2TP/IP", 593 .owner = THIS_MODULE, 594 .init = l2tp_ip_open, 595 .close = l2tp_ip_close, 596 .bind = l2tp_ip_bind, 597 .connect = l2tp_ip_connect, 598 .disconnect = udp_disconnect, 599 .ioctl = udp_ioctl, 600 .destroy = l2tp_ip_destroy_sock, 601 .setsockopt = ip_setsockopt, 602 .getsockopt = ip_getsockopt, 603 .sendmsg = l2tp_ip_sendmsg, 604 .recvmsg = l2tp_ip_recvmsg, 605 .backlog_rcv = l2tp_ip_backlog_recv, 606 .hash = inet_hash, 607 .unhash = inet_unhash, 608 .obj_size = sizeof(struct l2tp_ip_sock), 609 #ifdef CONFIG_COMPAT 610 .compat_setsockopt = compat_ip_setsockopt, 611 .compat_getsockopt = compat_ip_getsockopt, 612 #endif 613 }; 614 615 static const struct proto_ops l2tp_ip_ops = { 616 .family = PF_INET, 617 .owner = THIS_MODULE, 618 .release = inet_release, 619 .bind = inet_bind, 620 .connect = inet_dgram_connect, 621 .socketpair = sock_no_socketpair, 622 .accept = sock_no_accept, 623 .getname = l2tp_ip_getname, 624 .poll = datagram_poll, 625 .ioctl = inet_ioctl, 626 .listen = sock_no_listen, 627 .shutdown = inet_shutdown, 628 .setsockopt = sock_common_setsockopt, 629 .getsockopt = sock_common_getsockopt, 630 .sendmsg = inet_sendmsg, 631 .recvmsg = sock_common_recvmsg, 632 .mmap = sock_no_mmap, 633 .sendpage = sock_no_sendpage, 634 #ifdef CONFIG_COMPAT 635 .compat_setsockopt = compat_sock_common_setsockopt, 636 .compat_getsockopt = compat_sock_common_getsockopt, 637 #endif 638 }; 639 640 static struct inet_protosw l2tp_ip_protosw = { 641 .type = SOCK_DGRAM, 642 .protocol = IPPROTO_L2TP, 643 .prot = &l2tp_ip_prot, 644 .ops = &l2tp_ip_ops, 645 .no_check = 0, 646 }; 647 648 static struct net_protocol l2tp_ip_protocol __read_mostly = { 649 .handler = l2tp_ip_recv, 650 }; 651 652 static int __init l2tp_ip_init(void) 653 { 654 int err; 655 656 printk(KERN_INFO "L2TP IP encapsulation support (L2TPv3)\n"); 657 658 err = proto_register(&l2tp_ip_prot, 1); 659 if (err != 0) 660 goto out; 661 662 err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 663 if (err) 664 goto out1; 665 666 inet_register_protosw(&l2tp_ip_protosw); 667 return 0; 668 669 out1: 670 proto_unregister(&l2tp_ip_prot); 671 out: 672 return err; 673 } 674 675 static void __exit l2tp_ip_exit(void) 676 { 677 inet_unregister_protosw(&l2tp_ip_protosw); 678 inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 679 proto_unregister(&l2tp_ip_prot); 680 } 681 682 module_init(l2tp_ip_init); 683 module_exit(l2tp_ip_exit); 684 685 MODULE_LICENSE("GPL"); 686 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 687 MODULE_DESCRIPTION("L2TP over IP"); 688 MODULE_VERSION("1.0"); 689 690 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 691 * enums 692 */ 693 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP); 694