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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <asm/ioctls.h> 15 #include <linux/icmp.h> 16 #include <linux/module.h> 17 #include <linux/skbuff.h> 18 #include <linux/random.h> 19 #include <linux/socket.h> 20 #include <linux/l2tp.h> 21 #include <linux/in.h> 22 #include <net/sock.h> 23 #include <net/ip.h> 24 #include <net/icmp.h> 25 #include <net/udp.h> 26 #include <net/inet_common.h> 27 #include <net/inet_hashtables.h> 28 #include <net/tcp_states.h> 29 #include <net/protocol.h> 30 #include <net/xfrm.h> 31 32 #include "l2tp_core.h" 33 34 struct l2tp_ip_sock { 35 /* inet_sock has to be the first member of l2tp_ip_sock */ 36 struct inet_sock inet; 37 38 u32 conn_id; 39 u32 peer_conn_id; 40 }; 41 42 static DEFINE_RWLOCK(l2tp_ip_lock); 43 static struct hlist_head l2tp_ip_table; 44 static struct hlist_head l2tp_ip_bind_table; 45 46 static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) 47 { 48 return (struct l2tp_ip_sock *)sk; 49 } 50 51 static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr, 52 __be32 raddr, int dif, u32 tunnel_id) 53 { 54 struct sock *sk; 55 56 sk_for_each_bound(sk, &l2tp_ip_bind_table) { 57 const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); 58 const struct inet_sock *inet = inet_sk(sk); 59 60 if (!net_eq(sock_net(sk), net)) 61 continue; 62 63 if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif) 64 continue; 65 66 if (inet->inet_rcv_saddr && laddr && 67 inet->inet_rcv_saddr != laddr) 68 continue; 69 70 if (inet->inet_daddr && raddr && inet->inet_daddr != raddr) 71 continue; 72 73 if (l2tp->conn_id != tunnel_id) 74 continue; 75 76 goto found; 77 } 78 79 sk = NULL; 80 found: 81 return sk; 82 } 83 84 /* When processing receive frames, there are two cases to 85 * consider. Data frames consist of a non-zero session-id and an 86 * optional cookie. Control frames consist of a regular L2TP header 87 * preceded by 32-bits of zeros. 88 * 89 * L2TPv3 Session Header Over IP 90 * 91 * 0 1 2 3 92 * 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 93 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 94 * | Session ID | 95 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 96 * | Cookie (optional, maximum 64 bits)... 97 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 98 * | 99 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 100 * 101 * L2TPv3 Control Message Header Over IP 102 * 103 * 0 1 2 3 104 * 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 1 105 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 106 * | (32 bits of zeros) | 107 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 108 * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | 109 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 110 * | Control Connection ID | 111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 112 * | Ns | Nr | 113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 114 * 115 * All control frames are passed to userspace. 116 */ 117 static int l2tp_ip_recv(struct sk_buff *skb) 118 { 119 struct net *net = dev_net(skb->dev); 120 struct sock *sk; 121 u32 session_id; 122 u32 tunnel_id; 123 unsigned char *ptr, *optr; 124 struct l2tp_session *session; 125 struct l2tp_tunnel *tunnel = NULL; 126 struct iphdr *iph; 127 int length; 128 129 if (!pskb_may_pull(skb, 4)) 130 goto discard; 131 132 /* Point to L2TP header */ 133 optr = ptr = skb->data; 134 session_id = ntohl(*((__be32 *) ptr)); 135 ptr += 4; 136 137 /* RFC3931: L2TP/IP packets have the first 4 bytes containing 138 * the session_id. If it is 0, the packet is a L2TP control 139 * frame and the session_id value can be discarded. 140 */ 141 if (session_id == 0) { 142 __skb_pull(skb, 4); 143 goto pass_up; 144 } 145 146 /* Ok, this is a data packet. Lookup the session. */ 147 session = l2tp_session_get(net, session_id); 148 if (!session) 149 goto discard; 150 151 tunnel = session->tunnel; 152 if (!tunnel) 153 goto discard_sess; 154 155 /* Trace packet contents, if enabled */ 156 if (tunnel->debug & L2TP_MSG_DATA) { 157 length = min(32u, skb->len); 158 if (!pskb_may_pull(skb, length)) 159 goto discard_sess; 160 161 /* Point to L2TP header */ 162 optr = ptr = skb->data; 163 ptr += 4; 164 pr_debug("%s: ip recv\n", tunnel->name); 165 print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); 166 } 167 168 l2tp_recv_common(session, skb, ptr, optr, 0, skb->len); 169 l2tp_session_dec_refcount(session); 170 171 return 0; 172 173 pass_up: 174 /* Get the tunnel_id from the L2TP header */ 175 if (!pskb_may_pull(skb, 12)) 176 goto discard; 177 178 if ((skb->data[0] & 0xc0) != 0xc0) 179 goto discard; 180 181 tunnel_id = ntohl(*(__be32 *) &skb->data[4]); 182 iph = (struct iphdr *)skb_network_header(skb); 183 184 read_lock_bh(&l2tp_ip_lock); 185 sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr, inet_iif(skb), 186 tunnel_id); 187 if (!sk) { 188 read_unlock_bh(&l2tp_ip_lock); 189 goto discard; 190 } 191 sock_hold(sk); 192 read_unlock_bh(&l2tp_ip_lock); 193 194 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) 195 goto discard_put; 196 197 nf_reset(skb); 198 199 return sk_receive_skb(sk, skb, 1); 200 201 discard_sess: 202 l2tp_session_dec_refcount(session); 203 goto discard; 204 205 discard_put: 206 sock_put(sk); 207 208 discard: 209 kfree_skb(skb); 210 return 0; 211 } 212 213 static int l2tp_ip_open(struct sock *sk) 214 { 215 /* Prevent autobind. We don't have ports. */ 216 inet_sk(sk)->inet_num = IPPROTO_L2TP; 217 218 write_lock_bh(&l2tp_ip_lock); 219 sk_add_node(sk, &l2tp_ip_table); 220 write_unlock_bh(&l2tp_ip_lock); 221 222 return 0; 223 } 224 225 static void l2tp_ip_close(struct sock *sk, long timeout) 226 { 227 write_lock_bh(&l2tp_ip_lock); 228 hlist_del_init(&sk->sk_bind_node); 229 sk_del_node_init(sk); 230 write_unlock_bh(&l2tp_ip_lock); 231 sk_common_release(sk); 232 } 233 234 static void l2tp_ip_destroy_sock(struct sock *sk) 235 { 236 struct sk_buff *skb; 237 struct l2tp_tunnel *tunnel = sk->sk_user_data; 238 239 while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) 240 kfree_skb(skb); 241 242 if (tunnel) 243 l2tp_tunnel_delete(tunnel); 244 } 245 246 static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 247 { 248 struct inet_sock *inet = inet_sk(sk); 249 struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr; 250 struct net *net = sock_net(sk); 251 int ret; 252 int chk_addr_ret; 253 254 if (addr_len < sizeof(struct sockaddr_l2tpip)) 255 return -EINVAL; 256 if (addr->l2tp_family != AF_INET) 257 return -EINVAL; 258 259 lock_sock(sk); 260 261 ret = -EINVAL; 262 if (!sock_flag(sk, SOCK_ZAPPED)) 263 goto out; 264 265 if (sk->sk_state != TCP_CLOSE) 266 goto out; 267 268 chk_addr_ret = inet_addr_type(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 if (addr->l2tp_addr.s_addr) 275 inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; 276 if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) 277 inet->inet_saddr = 0; /* Use device */ 278 279 write_lock_bh(&l2tp_ip_lock); 280 if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0, 281 sk->sk_bound_dev_if, addr->l2tp_conn_id)) { 282 write_unlock_bh(&l2tp_ip_lock); 283 ret = -EADDRINUSE; 284 goto out; 285 } 286 287 sk_dst_reset(sk); 288 l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; 289 290 sk_add_bind_node(sk, &l2tp_ip_bind_table); 291 sk_del_node_init(sk); 292 write_unlock_bh(&l2tp_ip_lock); 293 294 ret = 0; 295 sock_reset_flag(sk, SOCK_ZAPPED); 296 297 out: 298 release_sock(sk); 299 300 return ret; 301 } 302 303 static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 304 { 305 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; 306 int rc; 307 308 if (addr_len < sizeof(*lsa)) 309 return -EINVAL; 310 311 if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) 312 return -EINVAL; 313 314 lock_sock(sk); 315 316 /* Must bind first - autobinding does not work */ 317 if (sock_flag(sk, SOCK_ZAPPED)) { 318 rc = -EINVAL; 319 goto out_sk; 320 } 321 322 rc = __ip4_datagram_connect(sk, uaddr, addr_len); 323 if (rc < 0) 324 goto out_sk; 325 326 l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; 327 328 write_lock_bh(&l2tp_ip_lock); 329 hlist_del_init(&sk->sk_bind_node); 330 sk_add_bind_node(sk, &l2tp_ip_bind_table); 331 write_unlock_bh(&l2tp_ip_lock); 332 333 out_sk: 334 release_sock(sk); 335 336 return rc; 337 } 338 339 static int l2tp_ip_disconnect(struct sock *sk, int flags) 340 { 341 if (sock_flag(sk, SOCK_ZAPPED)) 342 return 0; 343 344 return __udp_disconnect(sk, flags); 345 } 346 347 static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, 348 int peer) 349 { 350 struct sock *sk = sock->sk; 351 struct inet_sock *inet = inet_sk(sk); 352 struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); 353 struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; 354 355 memset(lsa, 0, sizeof(*lsa)); 356 lsa->l2tp_family = AF_INET; 357 if (peer) { 358 if (!inet->inet_dport) 359 return -ENOTCONN; 360 lsa->l2tp_conn_id = lsk->peer_conn_id; 361 lsa->l2tp_addr.s_addr = inet->inet_daddr; 362 } else { 363 __be32 addr = inet->inet_rcv_saddr; 364 if (!addr) 365 addr = inet->inet_saddr; 366 lsa->l2tp_conn_id = lsk->conn_id; 367 lsa->l2tp_addr.s_addr = addr; 368 } 369 return sizeof(*lsa); 370 } 371 372 static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) 373 { 374 int rc; 375 376 /* Charge it to the socket, dropping if the queue is full. */ 377 rc = sock_queue_rcv_skb(sk, skb); 378 if (rc < 0) 379 goto drop; 380 381 return 0; 382 383 drop: 384 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); 385 kfree_skb(skb); 386 return 0; 387 } 388 389 /* Userspace will call sendmsg() on the tunnel socket to send L2TP 390 * control frames. 391 */ 392 static int l2tp_ip_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 393 { 394 struct sk_buff *skb; 395 int rc; 396 struct inet_sock *inet = inet_sk(sk); 397 struct rtable *rt = NULL; 398 struct flowi4 *fl4; 399 int connected = 0; 400 __be32 daddr; 401 402 lock_sock(sk); 403 404 rc = -ENOTCONN; 405 if (sock_flag(sk, SOCK_DEAD)) 406 goto out; 407 408 /* Get and verify the address. */ 409 if (msg->msg_name) { 410 DECLARE_SOCKADDR(struct sockaddr_l2tpip *, lip, msg->msg_name); 411 rc = -EINVAL; 412 if (msg->msg_namelen < sizeof(*lip)) 413 goto out; 414 415 if (lip->l2tp_family != AF_INET) { 416 rc = -EAFNOSUPPORT; 417 if (lip->l2tp_family != AF_UNSPEC) 418 goto out; 419 } 420 421 daddr = lip->l2tp_addr.s_addr; 422 } else { 423 rc = -EDESTADDRREQ; 424 if (sk->sk_state != TCP_ESTABLISHED) 425 goto out; 426 427 daddr = inet->inet_daddr; 428 connected = 1; 429 } 430 431 /* Allocate a socket buffer */ 432 rc = -ENOMEM; 433 skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + 434 4 + len, 0, GFP_KERNEL); 435 if (!skb) 436 goto error; 437 438 /* Reserve space for headers, putting IP header on 4-byte boundary. */ 439 skb_reserve(skb, 2 + NET_SKB_PAD); 440 skb_reset_network_header(skb); 441 skb_reserve(skb, sizeof(struct iphdr)); 442 skb_reset_transport_header(skb); 443 444 /* Insert 0 session_id */ 445 *((__be32 *) skb_put(skb, 4)) = 0; 446 447 /* Copy user data into skb */ 448 rc = memcpy_from_msg(skb_put(skb, len), msg, len); 449 if (rc < 0) { 450 kfree_skb(skb); 451 goto error; 452 } 453 454 fl4 = &inet->cork.fl.u.ip4; 455 if (connected) 456 rt = (struct rtable *) __sk_dst_check(sk, 0); 457 458 rcu_read_lock(); 459 if (rt == NULL) { 460 const struct ip_options_rcu *inet_opt; 461 462 inet_opt = rcu_dereference(inet->inet_opt); 463 464 /* Use correct destination address if we have options. */ 465 if (inet_opt && inet_opt->opt.srr) 466 daddr = inet_opt->opt.faddr; 467 468 /* If this fails, retransmit mechanism of transport layer will 469 * keep trying until route appears or the connection times 470 * itself out. 471 */ 472 rt = ip_route_output_ports(sock_net(sk), fl4, sk, 473 daddr, inet->inet_saddr, 474 inet->inet_dport, inet->inet_sport, 475 sk->sk_protocol, RT_CONN_FLAGS(sk), 476 sk->sk_bound_dev_if); 477 if (IS_ERR(rt)) 478 goto no_route; 479 if (connected) { 480 sk_setup_caps(sk, &rt->dst); 481 } else { 482 skb_dst_set(skb, &rt->dst); 483 goto xmit; 484 } 485 } 486 487 /* We dont need to clone dst here, it is guaranteed to not disappear. 488 * __dev_xmit_skb() might force a refcount if needed. 489 */ 490 skb_dst_set_noref(skb, &rt->dst); 491 492 xmit: 493 /* Queue the packet to IP for output */ 494 rc = ip_queue_xmit(sk, skb, &inet->cork.fl); 495 rcu_read_unlock(); 496 497 error: 498 if (rc >= 0) 499 rc = len; 500 501 out: 502 release_sock(sk); 503 return rc; 504 505 no_route: 506 rcu_read_unlock(); 507 IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 508 kfree_skb(skb); 509 rc = -EHOSTUNREACH; 510 goto out; 511 } 512 513 static int l2tp_ip_recvmsg(struct sock *sk, struct msghdr *msg, 514 size_t len, int noblock, int flags, int *addr_len) 515 { 516 struct inet_sock *inet = inet_sk(sk); 517 size_t copied = 0; 518 int err = -EOPNOTSUPP; 519 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 520 struct sk_buff *skb; 521 522 if (flags & MSG_OOB) 523 goto out; 524 525 skb = skb_recv_datagram(sk, flags, noblock, &err); 526 if (!skb) 527 goto out; 528 529 copied = skb->len; 530 if (len < copied) { 531 msg->msg_flags |= MSG_TRUNC; 532 copied = len; 533 } 534 535 err = skb_copy_datagram_msg(skb, 0, msg, copied); 536 if (err) 537 goto done; 538 539 sock_recv_timestamp(msg, sk, skb); 540 541 /* Copy the address. */ 542 if (sin) { 543 sin->sin_family = AF_INET; 544 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 545 sin->sin_port = 0; 546 memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); 547 *addr_len = sizeof(*sin); 548 } 549 if (inet->cmsg_flags) 550 ip_cmsg_recv(msg, skb); 551 if (flags & MSG_TRUNC) 552 copied = skb->len; 553 done: 554 skb_free_datagram(sk, skb); 555 out: 556 return err ? err : copied; 557 } 558 559 int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg) 560 { 561 struct sk_buff *skb; 562 int amount; 563 564 switch (cmd) { 565 case SIOCOUTQ: 566 amount = sk_wmem_alloc_get(sk); 567 break; 568 case SIOCINQ: 569 spin_lock_bh(&sk->sk_receive_queue.lock); 570 skb = skb_peek(&sk->sk_receive_queue); 571 amount = skb ? skb->len : 0; 572 spin_unlock_bh(&sk->sk_receive_queue.lock); 573 break; 574 575 default: 576 return -ENOIOCTLCMD; 577 } 578 579 return put_user(amount, (int __user *)arg); 580 } 581 EXPORT_SYMBOL(l2tp_ioctl); 582 583 static struct proto l2tp_ip_prot = { 584 .name = "L2TP/IP", 585 .owner = THIS_MODULE, 586 .init = l2tp_ip_open, 587 .close = l2tp_ip_close, 588 .bind = l2tp_ip_bind, 589 .connect = l2tp_ip_connect, 590 .disconnect = l2tp_ip_disconnect, 591 .ioctl = l2tp_ioctl, 592 .destroy = l2tp_ip_destroy_sock, 593 .setsockopt = ip_setsockopt, 594 .getsockopt = ip_getsockopt, 595 .sendmsg = l2tp_ip_sendmsg, 596 .recvmsg = l2tp_ip_recvmsg, 597 .backlog_rcv = l2tp_ip_backlog_recv, 598 .hash = inet_hash, 599 .unhash = inet_unhash, 600 .obj_size = sizeof(struct l2tp_ip_sock), 601 #ifdef CONFIG_COMPAT 602 .compat_setsockopt = compat_ip_setsockopt, 603 .compat_getsockopt = compat_ip_getsockopt, 604 #endif 605 }; 606 607 static const struct proto_ops l2tp_ip_ops = { 608 .family = PF_INET, 609 .owner = THIS_MODULE, 610 .release = inet_release, 611 .bind = inet_bind, 612 .connect = inet_dgram_connect, 613 .socketpair = sock_no_socketpair, 614 .accept = sock_no_accept, 615 .getname = l2tp_ip_getname, 616 .poll = datagram_poll, 617 .ioctl = inet_ioctl, 618 .listen = sock_no_listen, 619 .shutdown = inet_shutdown, 620 .setsockopt = sock_common_setsockopt, 621 .getsockopt = sock_common_getsockopt, 622 .sendmsg = inet_sendmsg, 623 .recvmsg = sock_common_recvmsg, 624 .mmap = sock_no_mmap, 625 .sendpage = sock_no_sendpage, 626 #ifdef CONFIG_COMPAT 627 .compat_setsockopt = compat_sock_common_setsockopt, 628 .compat_getsockopt = compat_sock_common_getsockopt, 629 #endif 630 }; 631 632 static struct inet_protosw l2tp_ip_protosw = { 633 .type = SOCK_DGRAM, 634 .protocol = IPPROTO_L2TP, 635 .prot = &l2tp_ip_prot, 636 .ops = &l2tp_ip_ops, 637 }; 638 639 static struct net_protocol l2tp_ip_protocol __read_mostly = { 640 .handler = l2tp_ip_recv, 641 .netns_ok = 1, 642 }; 643 644 static int __init l2tp_ip_init(void) 645 { 646 int err; 647 648 pr_info("L2TP IP encapsulation support (L2TPv3)\n"); 649 650 err = proto_register(&l2tp_ip_prot, 1); 651 if (err != 0) 652 goto out; 653 654 err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 655 if (err) 656 goto out1; 657 658 inet_register_protosw(&l2tp_ip_protosw); 659 return 0; 660 661 out1: 662 proto_unregister(&l2tp_ip_prot); 663 out: 664 return err; 665 } 666 667 static void __exit l2tp_ip_exit(void) 668 { 669 inet_unregister_protosw(&l2tp_ip_protosw); 670 inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); 671 proto_unregister(&l2tp_ip_prot); 672 } 673 674 module_init(l2tp_ip_init); 675 module_exit(l2tp_ip_exit); 676 677 MODULE_LICENSE("GPL"); 678 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 679 MODULE_DESCRIPTION("L2TP over IP"); 680 MODULE_VERSION("1.0"); 681 682 /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like 683 * enums 684 */ 685 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP); 686 MODULE_ALIAS_NET_PF_PROTO(PF_INET, IPPROTO_L2TP); 687