[linux-block.git] / net / l2tp / l2tp_eth.c

/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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;
};

/* 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);
}

static int l2tp_eth_dev_init(struct net_device *dev)
{
	struct l2tp_eth *priv = netdev_priv(dev);

	priv->dev = dev;
	eth_hw_addr_random(dev);
	memset(&dev->broadcast[0], 0xff, 6);

	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;

	l2tp_xmit_skb(session, skb, session->hdr_len);

	dev->stats.tx_bytes += skb->len;
	dev->stats.tx_packets++;

	return 0;
}

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,
};

static void l2tp_eth_dev_setup(struct net_device *dev)
{
	ether_setup(dev);
	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	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;

	if (session->debug & L2TP_MSG_DATA) {
		unsigned int length;
		u8 *ptr = skb->data;

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

		pr_debug("%s: eth recv\n", session->name);
		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
	}

	if (!pskb_may_pull(skb, sizeof(ETH_HLEN)))
		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) {
		dev->stats.rx_packets++;
		dev->stats.rx_bytes += data_len;
	} else
		dev->stats.rx_errors++;

	return;

error:
	dev->stats.rx_errors++;
	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;
			module_put(THIS_MODULE);
		}
	}
}

#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
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

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;
#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
	session->show = l2tp_eth_show;
#endif

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

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

	__module_get(THIS_MODULE);
	/* 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);
out_del_session:
	l2tp_session_delete(session);
out:
	return rc;
}

static __net_init int l2tp_eth_init_net(struct net *net)
{
	struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);

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

	return 0;
}

static struct pernet_operations l2tp_eth_net_ops = {
	.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;

	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");

	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");
Commit	Line	Data
d9e31d17 JC	1	/*
	2	* L2TPv3 ethernet pseudowire driver
	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
a4ca44fa JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a4ca44fa JP	13
d9e31d17 JC	14	#include <linux/module.h>
	15	#include <linux/skbuff.h>
	16	#include <linux/socket.h>
	17	#include <linux/hash.h>
	18	#include <linux/l2tp.h>
	19	#include <linux/in.h>
	20	#include <linux/etherdevice.h>
	21	#include <linux/spinlock.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	#include <net/net_namespace.h>
	32	#include <net/netns/generic.h>
	33
	34	#include "l2tp_core.h"
	35
	36	/* Default device name. May be overridden by name specified by user */
	37	#define L2TP_ETH_DEV_NAME "l2tpeth%d"
	38
	39	/* via netdev_priv() */
	40	struct l2tp_eth {
	41	struct net_device *dev;
	42	struct sock *tunnel_sock;
	43	struct l2tp_session *session;
	44	struct list_head list;
	45	};
	46
	47	/* via l2tp_session_priv() */
	48	struct l2tp_eth_sess {
	49	struct net_device *dev;
	50	};
	51
	52	/* per-net private data for this module */
	53	static unsigned int l2tp_eth_net_id;
	54	struct l2tp_eth_net {
	55	struct list_head l2tp_eth_dev_list;
	56	spinlock_t l2tp_eth_lock;
	57	};
	58
	59	static inline struct l2tp_eth_net l2tp_eth_pernet(struct net net)
	60	{
	61	return net_generic(net, l2tp_eth_net_id);
	62	}
	63
	64	static int l2tp_eth_dev_init(struct net_device *dev)
	65	{
	66	struct l2tp_eth *priv = netdev_priv(dev);
	67
	68	priv->dev = dev;
f2cedb63	69	eth_hw_addr_random(dev);
d9e31d17 JC	70	memset(&dev->broadcast[0], 0xff, 6);
	71
	72	return 0;
	73	}
	74
	75	static void l2tp_eth_dev_uninit(struct net_device *dev)
	76	{
	77	struct l2tp_eth *priv = netdev_priv(dev);
	78	struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev));
	79
	80	spin_lock(&pn->l2tp_eth_lock);
	81	list_del_init(&priv->list);
	82	spin_unlock(&pn->l2tp_eth_lock);
	83	dev_put(dev);
	84	}
	85
	86	static int l2tp_eth_dev_xmit(struct sk_buff skb, struct net_device dev)
	87	{
	88	struct l2tp_eth *priv = netdev_priv(dev);
	89	struct l2tp_session *session = priv->session;
	90
	91	l2tp_xmit_skb(session, skb, session->hdr_len);
	92
	93	dev->stats.tx_bytes += skb->len;
	94	dev->stats.tx_packets++;
	95
	96	return 0;
	97	}
	98
	99	static struct net_device_ops l2tp_eth_netdev_ops = {
	100	.ndo_init = l2tp_eth_dev_init,
	101	.ndo_uninit = l2tp_eth_dev_uninit,
	102	.ndo_start_xmit = l2tp_eth_dev_xmit,
	103	};
	104
	105	static void l2tp_eth_dev_setup(struct net_device *dev)
	106	{
	107	ether_setup(dev);
550fd08c	108	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
d9e31d17 JC	109	dev->netdev_ops = &l2tp_eth_netdev_ops;
	110	dev->destructor = free_netdev;
	111	}
	112
	113	static void l2tp_eth_dev_recv(struct l2tp_session session, struct sk_buff skb, int data_len)
	114	{
	115	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
	116	struct net_device *dev = spriv->dev;
	117
	118	if (session->debug & L2TP_MSG_DATA) {
	119	unsigned int length;
d9e31d17 JC	120	u8 *ptr = skb->data;
	121
	122	length = min(32u, skb->len);
	123	if (!pskb_may_pull(skb, length))
	124	goto error;
	125
a4ca44fa JP	126	pr_debug("%s: eth recv\n", session->name);
a4ca44fa JP	127	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
d9e31d17 JC	128	}
d9e31d17 JC	129
bfc960a8	130	if (!pskb_may_pull(skb, sizeof(ETH_HLEN)))
d9e31d17 JC	131	goto error;
	132
	133	secpath_reset(skb);
	134
	135	/* checksums verified by L2TP */
	136	skb->ip_summed = CHECKSUM_NONE;
	137
	138	skb_dst_drop(skb);
	139	nf_reset(skb);
	140
	141	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
d9e31d17 JC	142	dev->stats.rx_packets++;
	143	dev->stats.rx_bytes += data_len;
	144	} else
	145	dev->stats.rx_errors++;
	146
	147	return;
	148
	149	error:
	150	dev->stats.rx_errors++;
	151	kfree_skb(skb);
	152	}
	153
	154	static void l2tp_eth_delete(struct l2tp_session *session)
	155	{
	156	struct l2tp_eth_sess *spriv;
	157	struct net_device *dev;
	158
	159	if (session) {
	160	spriv = l2tp_session_priv(session);
	161	dev = spriv->dev;
	162	if (dev) {
	163	unregister_netdev(dev);
	164	spriv->dev = NULL;
a06998b8	165	module_put(THIS_MODULE);
d9e31d17 JC	166	}
	167	}
	168	}
	169
f66ef2d0	170	#if defined(CONFIG_L2TP_DEBUGFS) \|\| defined(CONFIG_L2TP_DEBUGFS_MODULE)
0ad66140 JC	171	static void l2tp_eth_show(struct seq_file m, void arg)
	172	{
	173	struct l2tp_session *session = arg;
	174	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
	175	struct net_device *dev = spriv->dev;
	176
	177	seq_printf(m, " interface %s\n", dev->name);
	178	}
	179	#endif
	180
d9e31d17 JC	181	static int l2tp_eth_create(struct net net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg cfg)
	182	{
	183	struct net_device *dev;
	184	char name[IFNAMSIZ];
	185	struct l2tp_tunnel *tunnel;
	186	struct l2tp_session *session;
	187	struct l2tp_eth *priv;
	188	struct l2tp_eth_sess *spriv;
	189	int rc;
	190	struct l2tp_eth_net *pn;
	191
	192	tunnel = l2tp_tunnel_find(net, tunnel_id);
	193	if (!tunnel) {
	194	rc = -ENODEV;
	195	goto out;
	196	}
	197
	198	session = l2tp_session_find(net, tunnel, session_id);
	199	if (session) {
	200	rc = -EEXIST;
	201	goto out;
	202	}
	203
	204	if (cfg->ifname) {
	205	dev = dev_get_by_name(net, cfg->ifname);
	206	if (dev) {
	207	dev_put(dev);
	208	rc = -EEXIST;
	209	goto out;
	210	}
	211	strlcpy(name, cfg->ifname, IFNAMSIZ);
	212	} else
	213	strcpy(name, L2TP_ETH_DEV_NAME);
	214
	215	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
	216	peer_session_id, cfg);
	217	if (!session) {
	218	rc = -ENOMEM;
	219	goto out;
	220	}
	221
	222	dev = alloc_netdev(sizeof(*priv), name, l2tp_eth_dev_setup);
	223	if (!dev) {
	224	rc = -ENOMEM;
	225	goto out_del_session;
	226	}
	227
	228	dev_net_set(dev, net);
	229	if (session->mtu == 0)
	230	session->mtu = dev->mtu - session->hdr_len;
	231	dev->mtu = session->mtu;
	232	dev->needed_headroom += session->hdr_len;
	233
	234	priv = netdev_priv(dev);
	235	priv->dev = dev;
	236	priv->session = session;
	237	INIT_LIST_HEAD(&priv->list);
	238
	239	priv->tunnel_sock = tunnel->sock;
	240	session->recv_skb = l2tp_eth_dev_recv;
	241	session->session_close = l2tp_eth_delete;
f66ef2d0	242	#if defined(CONFIG_L2TP_DEBUGFS) \|\| defined(CONFIG_L2TP_DEBUGFS_MODULE)
0ad66140 JC	243	session->show = l2tp_eth_show;
0ad66140 JC	244	#endif
d9e31d17 JC	245
	246	spriv = l2tp_session_priv(session);
	247	spriv->dev = dev;
	248
	249	rc = register_netdev(dev);
	250	if (rc < 0)
	251	goto out_del_dev;
	252
a06998b8	253	__module_get(THIS_MODULE);
d9e31d17 JC	254	/* Must be done after register_netdev() */
	255	strlcpy(session->ifname, dev->name, IFNAMSIZ);
	256
	257	dev_hold(dev);
	258	pn = l2tp_eth_pernet(dev_net(dev));
	259	spin_lock(&pn->l2tp_eth_lock);
	260	list_add(&priv->list, &pn->l2tp_eth_dev_list);
	261	spin_unlock(&pn->l2tp_eth_lock);
	262
	263	return 0;
	264
	265	out_del_dev:
	266	free_netdev(dev);
	267	out_del_session:
	268	l2tp_session_delete(session);
	269	out:
	270	return rc;
	271	}
	272
	273	static __net_init int l2tp_eth_init_net(struct net *net)
	274	{
3a737028	275	struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id);
d9e31d17 JC	276
	277	INIT_LIST_HEAD(&pn->l2tp_eth_dev_list);
	278	spin_lock_init(&pn->l2tp_eth_lock);
	279
d9e31d17	280	return 0;
d9e31d17 JC	281	}
d9e31d17 JC	282
8aa525a9	283	static struct pernet_operations l2tp_eth_net_ops = {
d9e31d17	284	.init = l2tp_eth_init_net,
d9e31d17 JC	285	.id = &l2tp_eth_net_id,
	286	.size = sizeof(struct l2tp_eth_net),
	287	};
	288
	289
	290	static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
	291	.session_create = l2tp_eth_create,
	292	.session_delete = l2tp_session_delete,
	293	};
	294
	295
	296	static int __init l2tp_eth_init(void)
	297	{
	298	int err = 0;
	299
	300	err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
	301	if (err)
	302	goto out;
	303
	304	err = register_pernet_device(&l2tp_eth_net_ops);
	305	if (err)
	306	goto out_unreg;
	307
a4ca44fa	308	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
d9e31d17 JC	309
	310	return 0;
	311
	312	out_unreg:
	313	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
	314	out:
	315	return err;
	316	}
	317
	318	static void __exit l2tp_eth_exit(void)
	319	{
	320	unregister_pernet_device(&l2tp_eth_net_ops);
	321	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
	322	}
	323
	324	module_init(l2tp_eth_init);
	325	module_exit(l2tp_eth_exit);
	326
	327	MODULE_LICENSE("GPL");
	328	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	329	MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
	330	MODULE_VERSION("1.0");