l2tp_eth.c 8.3 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
/*
 * L2TPv3 ethernet pseudowire driver
 *
 * 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
37
38
39
40
41
42
43
44
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/hash.h>
#include <linux/l2tp.h>
#include <linux/in.h>
#include <linux/etherdevice.h>
#include <linux/spinlock.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 <net/net_namespace.h>
#include <net/netns/generic.h>

#include "l2tp_core.h"

/* Default device name. May be overridden by name specified by user */
#define L2TP_ETH_DEV_NAME	"l2tpeth%d"

/* via netdev_priv() */
struct l2tp_eth {
	struct net_device	*dev;
	struct sock		*tunnel_sock;
	struct l2tp_session	*session;
	struct list_head	list;
45
46
	atomic_long_t		tx_bytes;
	atomic_long_t		tx_packets;
47
	atomic_long_t		tx_dropped;
48
49
50
	atomic_long_t		rx_bytes;
	atomic_long_t		rx_packets;
	atomic_long_t		rx_errors;
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
};

/* via l2tp_session_priv() */
struct l2tp_eth_sess {
	struct net_device	*dev;
};

/* per-net private data for this module */
static unsigned int l2tp_eth_net_id;
struct l2tp_eth_net {
	struct list_head l2tp_eth_dev_list;
	spinlock_t l2tp_eth_lock;
};

static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net)
{
	return net_generic(net, l2tp_eth_net_id);
}

70
static struct lock_class_key l2tp_eth_tx_busylock;
71
72
73
74
75
static int l2tp_eth_dev_init(struct net_device *dev)
{
	struct l2tp_eth *priv = netdev_priv(dev);

	priv->dev = dev;
76
	eth_hw_addr_random(dev);
77
	memset(&dev->broadcast[0], 0xff, 6);
78
	dev->qdisc_tx_busylock = &l2tp_eth_tx_busylock;
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
	return 0;
}

static void l2tp_eth_dev_uninit(struct net_device *dev)
{
	struct l2tp_eth *priv = netdev_priv(dev);
	struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));

	spin_lock(&pn->l2tp_eth_lock);
	list_del_init(&priv->list);
	spin_unlock(&pn->l2tp_eth_lock);
	dev_put(dev);
}

static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct l2tp_eth *priv = netdev_priv(dev);
	struct l2tp_session *session = priv->session;
97
98
99
100
101
102
103
104
105
	unsigned int len = skb->len;
	int ret = l2tp_xmit_skb(session, skb, session->hdr_len);

	if (likely(ret == NET_XMIT_SUCCESS)) {
		atomic_long_add(len, &priv->tx_bytes);
		atomic_long_inc(&priv->tx_packets);
	} else {
		atomic_long_inc(&priv->tx_dropped);
	}
106
	return NETDEV_TX_OK;
107
108
}

109
110
111
112
113
114
115
static struct rtnl_link_stats64 *l2tp_eth_get_stats64(struct net_device *dev,
						      struct rtnl_link_stats64 *stats)
{
	struct l2tp_eth *priv = netdev_priv(dev);

	stats->tx_bytes   = atomic_long_read(&priv->tx_bytes);
	stats->tx_packets = atomic_long_read(&priv->tx_packets);
116
	stats->tx_dropped = atomic_long_read(&priv->tx_dropped);
117
118
119
120
121
122
123
	stats->rx_bytes   = atomic_long_read(&priv->rx_bytes);
	stats->rx_packets = atomic_long_read(&priv->rx_packets);
	stats->rx_errors  = atomic_long_read(&priv->rx_errors);
	return stats;
}


124
125
126
127
static struct net_device_ops l2tp_eth_netdev_ops = {
	.ndo_init		= l2tp_eth_dev_init,
	.ndo_uninit		= l2tp_eth_dev_uninit,
	.ndo_start_xmit		= l2tp_eth_dev_xmit,
128
	.ndo_get_stats64	= l2tp_eth_get_stats64,
129
130
131
132
133
};

static void l2tp_eth_dev_setup(struct net_device *dev)
{
	ether_setup(dev);
134
135
	dev->priv_flags		&= ~IFF_TX_SKB_SHARING;
	dev->features		|= NETIF_F_LLTX;
136
137
138
139
140
141
142
143
	dev->netdev_ops		= &l2tp_eth_netdev_ops;
	dev->destructor		= free_netdev;
}

static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
{
	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
	struct net_device *dev = spriv->dev;
144
	struct l2tp_eth *priv = netdev_priv(dev);
145
146
147
148
149
150
151
152

	if (session->debug & L2TP_MSG_DATA) {
		unsigned int length;

		length = min(32u, skb->len);
		if (!pskb_may_pull(skb, length))
			goto error;

153
		pr_debug("%s: eth recv\n", session->name);
154
		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
155
156
	}

157
	if (!pskb_may_pull(skb, ETH_HLEN))
158
159
160
161
162
163
164
165
166
167
168
		goto error;

	secpath_reset(skb);

	/* checksums verified by L2TP */
	skb->ip_summed = CHECKSUM_NONE;

	skb_dst_drop(skb);
	nf_reset(skb);

	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
169
170
171
172
173
		atomic_long_inc(&priv->rx_packets);
		atomic_long_add(data_len, &priv->rx_bytes);
	} else {
		atomic_long_inc(&priv->rx_errors);
	}
174
175
176
	return;

error:
177
	atomic_long_inc(&priv->rx_errors);
178
179
180
181
182
183
184
185
186
187
188
189
190
191
	kfree_skb(skb);
}

static void l2tp_eth_delete(struct l2tp_session *session)
{
	struct l2tp_eth_sess *spriv;
	struct net_device *dev;

	if (session) {
		spriv = l2tp_session_priv(session);
		dev = spriv->dev;
		if (dev) {
			unregister_netdev(dev);
			spriv->dev = NULL;
192
			module_put(THIS_MODULE);
193
194
195
196
		}
	}
}

197
#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
198
199
200
201
202
203
204
205
206
207
static void l2tp_eth_show(struct seq_file *m, void *arg)
{
	struct l2tp_session *session = arg;
	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
	struct net_device *dev = spriv->dev;

	seq_printf(m, "   interface %s\n", dev->name);
}
#endif

208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
{
	struct net_device *dev;
	char name[IFNAMSIZ];
	struct l2tp_tunnel *tunnel;
	struct l2tp_session *session;
	struct l2tp_eth *priv;
	struct l2tp_eth_sess *spriv;
	int rc;
	struct l2tp_eth_net *pn;

	tunnel = l2tp_tunnel_find(net, tunnel_id);
	if (!tunnel) {
		rc = -ENODEV;
		goto out;
	}

	session = l2tp_session_find(net, tunnel, session_id);
	if (session) {
		rc = -EEXIST;
		goto out;
	}

	if (cfg->ifname) {
		dev = dev_get_by_name(net, cfg->ifname);
		if (dev) {
			dev_put(dev);
			rc = -EEXIST;
			goto out;
		}
		strlcpy(name, cfg->ifname, IFNAMSIZ);
	} else
		strcpy(name, L2TP_ETH_DEV_NAME);

	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
				      peer_session_id, cfg);
	if (!session) {
		rc = -ENOMEM;
		goto out;
	}

	dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup);
	if (!dev) {
		rc = -ENOMEM;
		goto out_del_session;
	}

	dev_net_set(dev, net);
	if (session->mtu == 0)
		session->mtu = dev->mtu - session->hdr_len;
	dev->mtu = session->mtu;
	dev->needed_headroom += session->hdr_len;

	priv = netdev_priv(dev);
	priv->dev = dev;
	priv->session = session;
	INIT_LIST_HEAD(&priv->list);

	priv->tunnel_sock = tunnel->sock;
	session->recv_skb = l2tp_eth_dev_recv;
	session->session_close = l2tp_eth_delete;
269
#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
270
271
	session->show = l2tp_eth_show;
#endif
272
273
274
275
276
277
278
279

	spriv = l2tp_session_priv(session);
	spriv->dev = dev;

	rc = register_netdev(dev);
	if (rc < 0)
		goto out_del_dev;

280
	__module_get(THIS_MODULE);
281
282
283
284
285
286
287
288
289
290
291
292
293
	/* Must be done after register_netdev() */
	strlcpy(session->ifname, dev->name, IFNAMSIZ);

	dev_hold(dev);
	pn = l2tp_eth_pernet(dev_net(dev));
	spin_lock(&pn->l2tp_eth_lock);
	list_add(&priv->list, &pn->l2tp_eth_dev_list);
	spin_unlock(&pn->l2tp_eth_lock);

	return 0;

out_del_dev:
	free_netdev(dev);
294
	spriv->dev = NULL;
295
296
297
298
299
300
301
302
out_del_session:
	l2tp_session_delete(session);
out:
	return rc;
}

static __net_init int l2tp_eth_init_net(struct net *net)
{
Jiri Pirko's avatar
Jiri Pirko committed
303
	struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
304
305
306
307
308
309
310

	INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
	spin_lock_init(&pn->l2tp_eth_lock);

	return 0;
}

311
static struct pernet_operations l2tp_eth_net_ops = {
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
	.init = l2tp_eth_init_net,
	.id   = &l2tp_eth_net_id,
	.size = sizeof(struct l2tp_eth_net),
};


static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
	.session_create	= l2tp_eth_create,
	.session_delete	= l2tp_session_delete,
};


static int __init l2tp_eth_init(void)
{
	int err = 0;

	err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
	if (err)
		goto out;

	err = register_pernet_device(&l2tp_eth_net_ops);
	if (err)
		goto out_unreg;

336
	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358

	return 0;

out_unreg:
	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
out:
	return err;
}

static void __exit l2tp_eth_exit(void)
{
	unregister_pernet_device(&l2tp_eth_net_ops);
	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
}

module_init(l2tp_eth_init);
module_exit(l2tp_eth_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
MODULE_VERSION("1.0");