l2tp_ip.c 15.8 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
/*
 * L2TPv3 IP encapsulation support
 *
 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

12
13
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
#include <linux/icmp.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/random.h>
#include <linux/socket.h>
#include <linux/l2tp.h>
#include <linux/in.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
#include <net/tcp_states.h>
#include <net/protocol.h>
#include <net/xfrm.h>

#include "l2tp_core.h"

struct l2tp_ip_sock {
	/* inet_sock has to be the first member of l2tp_ip_sock */
	struct inet_sock	inet;

37
38
	u32			conn_id;
	u32			peer_conn_id;
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
};

static DEFINE_RWLOCK(l2tp_ip_lock);
static struct hlist_head l2tp_ip_table;
static struct hlist_head l2tp_ip_bind_table;

static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
{
	return (struct l2tp_ip_sock *)sk;
}

static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
{
	struct hlist_node *node;
	struct sock *sk;

	sk_for_each_bound(sk, node, &l2tp_ip_bind_table) {
		struct inet_sock *inet = inet_sk(sk);
		struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);

		if (l2tp == NULL)
			continue;

		if ((l2tp->conn_id == tunnel_id) &&
Eric Dumazet's avatar
Eric Dumazet committed
63
		    net_eq(sock_net(sk), net) &&
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
		    !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
			goto found;
	}

	sk = NULL;
found:
	return sk;
}

static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
{
	struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
	if (sk)
		sock_hold(sk);

	return sk;
}

/* When processing receive frames, there are two cases to
 * consider. Data frames consist of a non-zero session-id and an
 * optional cookie. Control frames consist of a regular L2TP header
 * preceded by 32-bits of zeros.
 *
 * L2TPv3 Session Header Over IP
 *
 *  0                   1                   2                   3
 *  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
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                           Session ID                          |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |               Cookie (optional, maximum 64 bits)...
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *                                                                 |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * L2TPv3 Control Message Header Over IP
 *
 *  0                   1                   2                   3
 *  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
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                      (32 bits of zeros)                       |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                     Control Connection ID                     |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |               Ns              |               Nr              |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * All control frames are passed to userspace.
 */
static int l2tp_ip_recv(struct sk_buff *skb)
{
118
	struct net *net = dev_net(skb->dev);
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
	struct sock *sk;
	u32 session_id;
	u32 tunnel_id;
	unsigned char *ptr, *optr;
	struct l2tp_session *session;
	struct l2tp_tunnel *tunnel = NULL;
	int length;

	/* Point to L2TP header */
	optr = ptr = skb->data;

	if (!pskb_may_pull(skb, 4))
		goto discard;

	session_id = ntohl(*((__be32 *) ptr));
	ptr += 4;

	/* RFC3931: L2TP/IP packets have the first 4 bytes containing
	 * the session_id. If it is 0, the packet is a L2TP control
	 * frame and the session_id value can be discarded.
	 */
	if (session_id == 0) {
		__skb_pull(skb, 4);
		goto pass_up;
	}

	/* Ok, this is a data packet. Lookup the session. */
146
	session = l2tp_session_find(net, NULL, session_id);
147
148
149
150
151
152
153
154
155
156
157
158
159
	if (session == NULL)
		goto discard;

	tunnel = session->tunnel;
	if (tunnel == NULL)
		goto discard;

	/* Trace packet contents, if enabled */
	if (tunnel->debug & L2TP_MSG_DATA) {
		length = min(32u, skb->len);
		if (!pskb_may_pull(skb, length))
			goto discard;

160
161
		pr_debug("%s: ip recv\n", tunnel->name);
		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
	}

	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook);

	return 0;

pass_up:
	/* Get the tunnel_id from the L2TP header */
	if (!pskb_may_pull(skb, 12))
		goto discard;

	if ((skb->data[0] & 0xc0) != 0xc0)
		goto discard;

	tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
177
	tunnel = l2tp_tunnel_find(net, tunnel_id);
178
179
180
181
182
183
	if (tunnel != NULL)
		sk = tunnel->sock;
	else {
		struct iphdr *iph = (struct iphdr *) skb_network_header(skb);

		read_lock_bh(&l2tp_ip_lock);
184
		sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id);
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
		read_unlock_bh(&l2tp_ip_lock);
	}

	if (sk == NULL)
		goto discard;

	sock_hold(sk);

	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
		goto discard_put;

	nf_reset(skb);

	return sk_receive_skb(sk, skb, 1);

discard_put:
	sock_put(sk);

discard:
	kfree_skb(skb);
	return 0;
}

static int l2tp_ip_open(struct sock *sk)
{
	/* Prevent autobind. We don't have ports. */
	inet_sk(sk)->inet_num = IPPROTO_L2TP;

	write_lock_bh(&l2tp_ip_lock);
	sk_add_node(sk, &l2tp_ip_table);
	write_unlock_bh(&l2tp_ip_lock);

	return 0;
}

static void l2tp_ip_close(struct sock *sk, long timeout)
{
	write_lock_bh(&l2tp_ip_lock);
	hlist_del_init(&sk->sk_bind_node);
224
	sk_del_node_init(sk);
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
	write_unlock_bh(&l2tp_ip_lock);
	sk_common_release(sk);
}

static void l2tp_ip_destroy_sock(struct sock *sk)
{
	struct sk_buff *skb;

	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
		kfree_skb(skb);

	sk_refcnt_debug_dec(sk);
}

static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr;
243
	struct net *net = sock_net(sk);
244
	int ret;
245
246
	int chk_addr_ret;

247
248
249
250
251
252
253
	if (!sock_flag(sk, SOCK_ZAPPED))
		return -EINVAL;
	if (addr_len < sizeof(struct sockaddr_l2tpip))
		return -EINVAL;
	if (addr->l2tp_family != AF_INET)
		return -EINVAL;

254
255
	ret = -EADDRINUSE;
	read_lock_bh(&l2tp_ip_lock);
256
257
	if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,
				  sk->sk_bound_dev_if, addr->l2tp_conn_id))
258
259
260
261
262
263
264
265
		goto out_in_use;

	read_unlock_bh(&l2tp_ip_lock);

	lock_sock(sk);
	if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
		goto out;

266
	chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);
267
268
269
270
271
	ret = -EADDRNOTAVAIL;
	if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
	    chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
		goto out;

272
273
	if (addr->l2tp_addr.s_addr)
		inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr;
274
275
276
277
278
279
280
281
282
283
284
	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
		inet->inet_saddr = 0;  /* Use device */
	sk_dst_reset(sk);

	l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id;

	write_lock_bh(&l2tp_ip_lock);
	sk_add_bind_node(sk, &l2tp_ip_bind_table);
	sk_del_node_init(sk);
	write_unlock_bh(&l2tp_ip_lock);
	ret = 0;
285
286
	sock_reset_flag(sk, SOCK_ZAPPED);

287
288
289
290
291
292
293
294
295
296
297
298
299
300
out:
	release_sock(sk);

	return ret;

out_in_use:
	read_unlock_bh(&l2tp_ip_lock);

	return ret;
}

static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr;
301
	int rc;
302

303
304
305
	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
		return -EINVAL;

306
	if (addr_len < sizeof(*lsa))
307
		return -EINVAL;
308

309
	if (ipv4_is_multicast(lsa->l2tp_addr.s_addr))
310
		return -EINVAL;
311

312
313
314
	rc = ip4_datagram_connect(sk, uaddr, addr_len);
	if (rc < 0)
		return rc;
315

316
	lock_sock(sk);
317
318
319
320
321
322
323
324

	l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;

	write_lock_bh(&l2tp_ip_lock);
	hlist_del_init(&sk->sk_bind_node);
	sk_add_bind_node(sk, &l2tp_ip_bind_table);
	write_unlock_bh(&l2tp_ip_lock);

325
	release_sock(sk);
326
327
328
	return rc;
}

329
330
331
332
333
334
335
336
static int l2tp_ip_disconnect(struct sock *sk, int flags)
{
	if (sock_flag(sk, SOCK_ZAPPED))
		return 0;

	return udp_disconnect(sk, flags);
}

337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
			   int *uaddr_len, int peer)
{
	struct sock *sk		= sock->sk;
	struct inet_sock *inet	= inet_sk(sk);
	struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk);
	struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr;

	memset(lsa, 0, sizeof(*lsa));
	lsa->l2tp_family = AF_INET;
	if (peer) {
		if (!inet->inet_dport)
			return -ENOTCONN;
		lsa->l2tp_conn_id = lsk->peer_conn_id;
		lsa->l2tp_addr.s_addr = inet->inet_daddr;
	} else {
		__be32 addr = inet->inet_rcv_saddr;
		if (!addr)
			addr = inet->inet_saddr;
		lsa->l2tp_conn_id = lsk->conn_id;
		lsa->l2tp_addr.s_addr = addr;
	}
	*uaddr_len = sizeof(*lsa);
	return 0;
}

static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb)
{
	int rc;

	/* Charge it to the socket, dropping if the queue is full. */
	rc = sock_queue_rcv_skb(sk, skb);
	if (rc < 0)
		goto drop;

	return 0;

drop:
375
	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS);
376
377
378
379
380
381
382
383
384
385
386
387
388
	kfree_skb(skb);
	return -1;
}

/* Userspace will call sendmsg() on the tunnel socket to send L2TP
 * control frames.
 */
static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len)
{
	struct sk_buff *skb;
	int rc;
	struct inet_sock *inet = inet_sk(sk);
	struct rtable *rt = NULL;
389
	struct flowi4 *fl4;
390
391
392
	int connected = 0;
	__be32 daddr;

393
394
395
	lock_sock(sk);

	rc = -ENOTCONN;
396
	if (sock_flag(sk, SOCK_DEAD))
397
		goto out;
398
399
400
401

	/* Get and verify the address. */
	if (msg->msg_name) {
		struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name;
402
		rc = -EINVAL;
403
		if (msg->msg_namelen < sizeof(*lip))
404
			goto out;
405
406

		if (lip->l2tp_family != AF_INET) {
407
			rc = -EAFNOSUPPORT;
408
			if (lip->l2tp_family != AF_UNSPEC)
409
				goto out;
410
411
412
413
		}

		daddr = lip->l2tp_addr.s_addr;
	} else {
414
		rc = -EDESTADDRREQ;
415
		if (sk->sk_state != TCP_ESTABLISHED)
416
			goto out;
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444

		daddr = inet->inet_daddr;
		connected = 1;
	}

	/* Allocate a socket buffer */
	rc = -ENOMEM;
	skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) +
			   4 + len, 0, GFP_KERNEL);
	if (!skb)
		goto error;

	/* Reserve space for headers, putting IP header on 4-byte boundary. */
	skb_reserve(skb, 2 + NET_SKB_PAD);
	skb_reset_network_header(skb);
	skb_reserve(skb, sizeof(struct iphdr));
	skb_reset_transport_header(skb);

	/* Insert 0 session_id */
	*((__be32 *) skb_put(skb, 4)) = 0;

	/* Copy user data into skb */
	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
	if (rc < 0) {
		kfree_skb(skb);
		goto error;
	}

445
	fl4 = &inet->cork.fl.u.ip4;
446
447
448
	if (connected)
		rt = (struct rtable *) __sk_dst_check(sk, 0);

449
	rcu_read_lock();
450
	if (rt == NULL) {
451
		const struct ip_options_rcu *inet_opt;
452

453
		inet_opt = rcu_dereference(inet->inet_opt);
454

455
		/* Use correct destination address if we have options. */
456
457
		if (inet_opt && inet_opt->opt.srr)
			daddr = inet_opt->opt.faddr;
458

459
460
461
462
		/* If this fails, retransmit mechanism of transport layer will
		 * keep trying until route appears or the connection times
		 * itself out.
		 */
463
		rt = ip_route_output_ports(sock_net(sk), fl4, sk,
464
465
466
467
468
469
					   daddr, inet->inet_saddr,
					   inet->inet_dport, inet->inet_sport,
					   sk->sk_protocol, RT_CONN_FLAGS(sk),
					   sk->sk_bound_dev_if);
		if (IS_ERR(rt))
			goto no_route;
470
		if (connected) {
471
			sk_setup_caps(sk, &rt->dst);
472
473
474
475
		} else {
			skb_dst_set(skb, &rt->dst);
			goto xmit;
		}
476
	}
477
478
479
480
481

	/* We dont need to clone dst here, it is guaranteed to not disappear.
	 *  __dev_xmit_skb() might force a refcount if needed.
	 */
	skb_dst_set_noref(skb, &rt->dst);
482

483
xmit:
484
	/* Queue the packet to IP for output */
485
	rc = ip_queue_xmit(skb, &inet->cork.fl);
486
	rcu_read_unlock();
487
488

error:
489
	if (rc >= 0)
490
491
		rc = len;

492
493
out:
	release_sock(sk);
494
495
496
	return rc;

no_route:
497
	rcu_read_unlock();
498
499
	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
	kfree_skb(skb);
500
501
	rc = -EHOSTUNREACH;
	goto out;
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
}

static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
			   size_t len, int noblock, int flags, int *addr_len)
{
	struct inet_sock *inet = inet_sk(sk);
	size_t copied = 0;
	int err = -EOPNOTSUPP;
	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
	struct sk_buff *skb;

	if (flags & MSG_OOB)
		goto out;

	if (addr_len)
		*addr_len = sizeof(*sin);

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb)
		goto out;

	copied = skb->len;
	if (len < copied) {
		msg->msg_flags |= MSG_TRUNC;
		copied = len;
	}

	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
	if (err)
		goto done;

	sock_recv_timestamp(msg, sk, skb);

	/* Copy the address. */
	if (sin) {
		sin->sin_family = AF_INET;
		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
		sin->sin_port = 0;
		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
	}
	if (inet->cmsg_flags)
		ip_cmsg_recv(msg, skb);
	if (flags & MSG_TRUNC)
		copied = skb->len;
done:
	skb_free_datagram(sk, skb);
out:
549
	return err ? err : copied;
550
551
}

552
static struct proto l2tp_ip_prot = {
553
554
555
556
557
558
	.name		   = "L2TP/IP",
	.owner		   = THIS_MODULE,
	.init		   = l2tp_ip_open,
	.close		   = l2tp_ip_close,
	.bind		   = l2tp_ip_bind,
	.connect	   = l2tp_ip_connect,
559
	.disconnect	   = l2tp_ip_disconnect,
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
	.ioctl		   = udp_ioctl,
	.destroy	   = l2tp_ip_destroy_sock,
	.setsockopt	   = ip_setsockopt,
	.getsockopt	   = ip_getsockopt,
	.sendmsg	   = l2tp_ip_sendmsg,
	.recvmsg	   = l2tp_ip_recvmsg,
	.backlog_rcv	   = l2tp_ip_backlog_recv,
	.hash		   = inet_hash,
	.unhash		   = inet_unhash,
	.obj_size	   = sizeof(struct l2tp_ip_sock),
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_ip_setsockopt,
	.compat_getsockopt = compat_ip_getsockopt,
#endif
};

static const struct proto_ops l2tp_ip_ops = {
	.family		   = PF_INET,
	.owner		   = THIS_MODULE,
	.release	   = inet_release,
	.bind		   = inet_bind,
	.connect	   = inet_dgram_connect,
	.socketpair	   = sock_no_socketpair,
	.accept		   = sock_no_accept,
	.getname	   = l2tp_ip_getname,
	.poll		   = datagram_poll,
	.ioctl		   = inet_ioctl,
	.listen		   = sock_no_listen,
	.shutdown	   = inet_shutdown,
	.setsockopt	   = sock_common_setsockopt,
	.getsockopt	   = sock_common_getsockopt,
	.sendmsg	   = inet_sendmsg,
	.recvmsg	   = sock_common_recvmsg,
	.mmap		   = sock_no_mmap,
	.sendpage	   = sock_no_sendpage,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_sock_common_setsockopt,
	.compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

static struct inet_protosw l2tp_ip_protosw = {
	.type		= SOCK_DGRAM,
	.protocol	= IPPROTO_L2TP,
	.prot		= &l2tp_ip_prot,
	.ops		= &l2tp_ip_ops,
	.no_check	= 0,
};

static struct net_protocol l2tp_ip_protocol __read_mostly = {
	.handler	= l2tp_ip_recv,
611
	.netns_ok	= 1,
612
613
614
615
616
617
};

static int __init l2tp_ip_init(void)
{
	int err;

618
	pr_info("L2TP IP encapsulation support (L2TPv3)\n");
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650

	err = proto_register(&l2tp_ip_prot, 1);
	if (err != 0)
		goto out;

	err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
	if (err)
		goto out1;

	inet_register_protosw(&l2tp_ip_protosw);
	return 0;

out1:
	proto_unregister(&l2tp_ip_prot);
out:
	return err;
}

static void __exit l2tp_ip_exit(void)
{
	inet_unregister_protosw(&l2tp_ip_protosw);
	inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP);
	proto_unregister(&l2tp_ip_prot);
}

module_init(l2tp_ip_init);
module_exit(l2tp_ip_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("L2TP over IP");
MODULE_VERSION("1.0");
Michal Marek's avatar
Michal Marek committed
651

652
/* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
Michal Marek's avatar
Michal Marek committed
653
654
655
 * enums
 */
MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 2, IPPROTO_L2TP);