[linux-2.6-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 <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.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 l2tp_session	*session;
	atomic_long_t		tx_bytes;
	atomic_long_t		tx_packets;
	atomic_long_t		tx_dropped;
	atomic_long_t		rx_bytes;
	atomic_long_t		rx_packets;
	atomic_long_t		rx_errors;
};

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


static int l2tp_eth_dev_init(struct net_device *dev)
{
	eth_hw_addr_random(dev);
	eth_broadcast_addr(dev->broadcast);
	netdev_lockdep_set_classes(dev);

	return 0;
}

static void l2tp_eth_dev_uninit(struct net_device *dev)
{
	struct l2tp_eth *priv = netdev_priv(dev);
	struct l2tp_eth_sess *spriv;

	spriv = l2tp_session_priv(priv->session);
	RCU_INIT_POINTER(spriv->dev, NULL);
	/* No need for synchronize_net() here. We're called by
	 * unregister_netdev*(), which does the synchronisation for us.
	 */
}

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;
	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);
	}
	return NETDEV_TX_OK;
}

static void l2tp_eth_get_stats64(struct net_device *dev,
				 struct rtnl_link_stats64 *stats)
{
	struct l2tp_eth *priv = netdev_priv(dev);

	stats->tx_bytes   = (unsigned long) atomic_long_read(&priv->tx_bytes);
	stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
	stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
	stats->rx_bytes   = (unsigned long) atomic_long_read(&priv->rx_bytes);
	stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
	stats->rx_errors  = (unsigned long) atomic_long_read(&priv->rx_errors);

}

static const 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,
	.ndo_get_stats64	= l2tp_eth_get_stats64,
	.ndo_set_mac_address	= eth_mac_addr,
};

static struct device_type l2tpeth_type = {
	.name = "l2tpeth",
};

static void l2tp_eth_dev_setup(struct net_device *dev)
{
	SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
	ether_setup(dev);
	dev->priv_flags		&= ~IFF_TX_SKB_SHARING;
	dev->features		|= NETIF_F_LLTX;
	dev->netdev_ops		= &l2tp_eth_netdev_ops;
	dev->needs_free_netdev	= true;
}

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;
	struct l2tp_eth *priv;

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

		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, skb->data, length);
	}

	if (!pskb_may_pull(skb, ETH_HLEN))
		goto error;

	secpath_reset(skb);

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

	skb_dst_drop(skb);
	nf_reset(skb);

	rcu_read_lock();
	dev = rcu_dereference(spriv->dev);
	if (!dev)
		goto error_rcu;

	priv = netdev_priv(dev);
	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
		atomic_long_inc(&priv->rx_packets);
		atomic_long_add(data_len, &priv->rx_bytes);
	} else {
		atomic_long_inc(&priv->rx_errors);
	}
	rcu_read_unlock();

	return;

error_rcu:
	rcu_read_unlock();
error:
	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);

		rtnl_lock();
		dev = rtnl_dereference(spriv->dev);
		if (dev) {
			unregister_netdevice(dev);
			rtnl_unlock();
			module_put(THIS_MODULE);
		} else {
			rtnl_unlock();
		}
	}
}

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;

	rcu_read_lock();
	dev = rcu_dereference(spriv->dev);
	if (!dev) {
		rcu_read_unlock();
		return;
	}
	dev_hold(dev);
	rcu_read_unlock();

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

	dev_put(dev);
}

static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
				struct l2tp_session *session,
				struct net_device *dev)
{
	unsigned int overhead = 0;
	u32 l3_overhead = 0;
	u32 mtu;

	/* if the encap is UDP, account for UDP header size */
	if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
		overhead += sizeof(struct udphdr);
		dev->needed_headroom += sizeof(struct udphdr);
	}

	lock_sock(tunnel->sock);
	l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
	release_sock(tunnel->sock);

	if (l3_overhead == 0) {
		/* L3 Overhead couldn't be identified, this could be
		 * because tunnel->sock was NULL or the socket's
		 * address family was not IPv4 or IPv6,
		 * dev mtu stays at 1500.
		 */
		return;
	}
	/* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
	 * UDP overhead, if any, was already factored in above.
	 */
	overhead += session->hdr_len + ETH_HLEN + l3_overhead;

	mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
	if (mtu < dev->min_mtu || mtu > dev->max_mtu)
		dev->mtu = ETH_DATA_LEN - overhead;
	else
		dev->mtu = mtu;

	dev->needed_headroom += session->hdr_len;
}

static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
			   u32 session_id, u32 peer_session_id,
			   struct l2tp_session_cfg *cfg)
{
	unsigned char name_assign_type;
	struct net_device *dev;
	char name[IFNAMSIZ];
	struct l2tp_session *session;
	struct l2tp_eth *priv;
	struct l2tp_eth_sess *spriv;
	int rc;

	if (cfg->ifname) {
		strlcpy(name, cfg->ifname, IFNAMSIZ);
		name_assign_type = NET_NAME_USER;
	} else {
		strcpy(name, L2TP_ETH_DEV_NAME);
		name_assign_type = NET_NAME_ENUM;
	}

	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
				      peer_session_id, cfg);
	if (IS_ERR(session)) {
		rc = PTR_ERR(session);
		goto err;
	}

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

	dev_net_set(dev, net);
	dev->min_mtu = 0;
	dev->max_mtu = ETH_MAX_MTU;
	l2tp_eth_adjust_mtu(tunnel, session, dev);

	priv = netdev_priv(dev);
	priv->session = session;

	session->recv_skb = l2tp_eth_dev_recv;
	session->session_close = l2tp_eth_delete;
	if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
		session->show = l2tp_eth_show;

	spriv = l2tp_session_priv(session);

	l2tp_session_inc_refcount(session);

	rtnl_lock();

	/* Register both device and session while holding the rtnl lock. This
	 * ensures that l2tp_eth_delete() will see that there's a device to
	 * unregister, even if it happened to run before we assign spriv->dev.
	 */
	rc = l2tp_session_register(session, tunnel);
	if (rc < 0) {
		rtnl_unlock();
		goto err_sess_dev;
	}

	rc = register_netdevice(dev);
	if (rc < 0) {
		rtnl_unlock();
		l2tp_session_delete(session);
		l2tp_session_dec_refcount(session);
		free_netdev(dev);

		return rc;
	}

	strlcpy(session->ifname, dev->name, IFNAMSIZ);
	rcu_assign_pointer(spriv->dev, dev);

	rtnl_unlock();

	l2tp_session_dec_refcount(session);

	__module_get(THIS_MODULE);

	return 0;

err_sess_dev:
	l2tp_session_dec_refcount(session);
	free_netdev(dev);
err_sess:
	kfree(session);
err:
	return rc;
}


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 err;

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

	return 0;

err:
	return err;
}

static void __exit l2tp_eth_exit(void)
{
	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");
MODULE_ALIAS_L2TP_PWTYPE(5);
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>
b784e7eb P	33	#include <linux/ip.h>
	34	#include <linux/ipv6.h>
	35	#include <linux/udp.h>
d9e31d17 JC	36
	37	#include "l2tp_core.h"
	38
	39	/* Default device name. May be overridden by name specified by user */
	40	#define L2TP_ETH_DEV_NAME "l2tpeth%d"
	41
	42	/* via netdev_priv() */
	43	struct l2tp_eth {
d9e31d17	44	struct l2tp_session *session;
a2842a1e ED	45	atomic_long_t tx_bytes;
a2842a1e ED	46	atomic_long_t tx_packets;
b8c84307	47	atomic_long_t tx_dropped;
a2842a1e ED	48	atomic_long_t rx_bytes;
	49	atomic_long_t rx_packets;
	50	atomic_long_t rx_errors;
d9e31d17 JC	51	};
	52
	53	/* via l2tp_session_priv() */
	54	struct l2tp_eth_sess {
ee28de6b	55	struct net_device __rcu *dev;
d9e31d17 JC	56	};
d9e31d17 JC	57
d9e31d17 JC	58
	59	static int l2tp_eth_dev_init(struct net_device *dev)
	60	{
f2cedb63	61	eth_hw_addr_random(dev);
1cea7e2c	62	eth_broadcast_addr(dev->broadcast);
d3fff6c4	63	netdev_lockdep_set_classes(dev);
f9eb8aea	64
d9e31d17 JC	65	return 0;
	66	}
	67
	68	static void l2tp_eth_dev_uninit(struct net_device *dev)
	69	{
ee28de6b GN	70	struct l2tp_eth *priv = netdev_priv(dev);
	71	struct l2tp_eth_sess *spriv;
	72
	73	spriv = l2tp_session_priv(priv->session);
	74	RCU_INIT_POINTER(spriv->dev, NULL);
	75	/* No need for synchronize_net() here. We're called by
	76	* unregister_netdev*(), which does the synchronisation for us.
	77	*/
d9e31d17 JC	78	}
	79
	80	static int l2tp_eth_dev_xmit(struct sk_buff skb, struct net_device dev)
	81	{
	82	struct l2tp_eth *priv = netdev_priv(dev);
	83	struct l2tp_session *session = priv->session;
b8c84307 ED	84	unsigned int len = skb->len;
	85	int ret = l2tp_xmit_skb(session, skb, session->hdr_len);
	86
a4cd0271	87	if (likely(ret == NET_XMIT_SUCCESS)) {
b8c84307 ED	88	atomic_long_add(len, &priv->tx_bytes);
	89	atomic_long_inc(&priv->tx_packets);
	90	} else {
	91	atomic_long_inc(&priv->tx_dropped);
	92	}
aa214de0	93	return NETDEV_TX_OK;
d9e31d17 JC	94	}
d9e31d17 JC	95
bc1f4470	96	static void l2tp_eth_get_stats64(struct net_device *dev,
bc1f4470	97	struct rtnl_link_stats64 *stats)
a2842a1e ED	98	{
	99	struct l2tp_eth *priv = netdev_priv(dev);
	100
9b3dc0a1 DH	101	stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes);
	102	stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
	103	stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
	104	stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes);
	105	stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
	106	stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors);
	107
a2842a1e ED	108	}
a2842a1e ED	109
eb94737d	110	static const struct net_device_ops l2tp_eth_netdev_ops = {
d9e31d17 JC	111	.ndo_init = l2tp_eth_dev_init,
	112	.ndo_uninit = l2tp_eth_dev_uninit,
	113	.ndo_start_xmit = l2tp_eth_dev_xmit,
a2842a1e	114	.ndo_get_stats64 = l2tp_eth_get_stats64,
fe159122	115	.ndo_set_mac_address = eth_mac_addr,
d9e31d17 JC	116	};
d9e31d17 JC	117
a485c2b8 GN	118	static struct device_type l2tpeth_type = {
	119	.name = "l2tpeth",
	120	};
	121
d9e31d17 JC	122	static void l2tp_eth_dev_setup(struct net_device *dev)
d9e31d17 JC	123	{
a485c2b8	124	SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
d9e31d17	125	ether_setup(dev);
a2842a1e ED	126	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
a2842a1e ED	127	dev->features \|= NETIF_F_LLTX;
d9e31d17	128	dev->netdev_ops = &l2tp_eth_netdev_ops;
cf124db5	129	dev->needs_free_netdev = true;
d9e31d17 JC	130	}
	131
	132	static void l2tp_eth_dev_recv(struct l2tp_session session, struct sk_buff skb, int data_len)
	133	{
	134	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	135	struct net_device *dev;
ee28de6b GN	136	struct l2tp_eth *priv;
d9e31d17 JC	137
	138	if (session->debug & L2TP_MSG_DATA) {
	139	unsigned int length;
d9e31d17 JC	140
	141	length = min(32u, skb->len);
	142	if (!pskb_may_pull(skb, length))
	143	goto error;
	144
a4ca44fa	145	pr_debug("%s: eth recv\n", session->name);
a2842a1e	146	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
d9e31d17 JC	147	}
d9e31d17 JC	148
c0cc88a7	149	if (!pskb_may_pull(skb, ETH_HLEN))
d9e31d17 JC	150	goto error;
	151
	152	secpath_reset(skb);
	153
	154	/* checksums verified by L2TP */
	155	skb->ip_summed = CHECKSUM_NONE;
	156
	157	skb_dst_drop(skb);
	158	nf_reset(skb);
	159
ee28de6b GN	160	rcu_read_lock();
	161	dev = rcu_dereference(spriv->dev);
	162	if (!dev)
	163	goto error_rcu;
	164
	165	priv = netdev_priv(dev);
d9e31d17	166	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
a2842a1e ED	167	atomic_long_inc(&priv->rx_packets);
	168	atomic_long_add(data_len, &priv->rx_bytes);
	169	} else {
	170	atomic_long_inc(&priv->rx_errors);
	171	}
ee28de6b GN	172	rcu_read_unlock();
ee28de6b GN	173
d9e31d17 JC	174	return;
d9e31d17 JC	175
ee28de6b GN	176	error_rcu:
ee28de6b GN	177	rcu_read_unlock();
d9e31d17	178	error:
d9e31d17 JC	179	kfree_skb(skb);
	180	}
	181
	182	static void l2tp_eth_delete(struct l2tp_session *session)
	183	{
	184	struct l2tp_eth_sess *spriv;
	185	struct net_device *dev;
	186
	187	if (session) {
	188	spriv = l2tp_session_priv(session);
ee28de6b GN	189
	190	rtnl_lock();
	191	dev = rtnl_dereference(spriv->dev);
d9e31d17	192	if (dev) {
ee28de6b GN	193	unregister_netdevice(dev);
ee28de6b GN	194	rtnl_unlock();
a06998b8	195	module_put(THIS_MODULE);
ee28de6b GN	196	} else {
ee28de6b GN	197	rtnl_unlock();
d9e31d17 JC	198	}
	199	}
	200	}
	201
0ad66140 JC	202	static void l2tp_eth_show(struct seq_file m, void arg)
	203	{
	204	struct l2tp_session *session = arg;
	205	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	206	struct net_device *dev;
	207
	208	rcu_read_lock();
	209	dev = rcu_dereference(spriv->dev);
	210	if (!dev) {
	211	rcu_read_unlock();
	212	return;
	213	}
	214	dev_hold(dev);
	215	rcu_read_unlock();
0ad66140 JC	216
0ad66140 JC	217	seq_printf(m, " interface %s\n", dev->name);
ee28de6b GN	218
ee28de6b GN	219	dev_put(dev);
0ad66140	220	}
0ad66140	221
b784e7eb P	222	static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
	223	struct l2tp_session *session,
	224	struct net_device *dev)
	225	{
	226	unsigned int overhead = 0;
b784e7eb	227	u32 l3_overhead = 0;
1f5cd2a0	228	u32 mtu;
b784e7eb P	229
	230	/* if the encap is UDP, account for UDP header size */
	231	if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
	232	overhead += sizeof(struct udphdr);
	233	dev->needed_headroom += sizeof(struct udphdr);
	234	}
e9697e2e	235
57240d00	236	lock_sock(tunnel->sock);
b784e7eb	237	l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
57240d00	238	release_sock(tunnel->sock);
e9697e2e	239
b784e7eb P	240	if (l3_overhead == 0) {
	241	/* L3 Overhead couldn't be identified, this could be
	242	* because tunnel->sock was NULL or the socket's
	243	* address family was not IPv4 or IPv6,
	244	* dev mtu stays at 1500.
	245	*/
	246	return;
	247	}
	248	/* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
	249	* UDP overhead, if any, was already factored in above.
	250	*/
	251	overhead += session->hdr_len + ETH_HLEN + l3_overhead;
	252
e9697e2e GN	253	mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
	254	if (mtu < dev->min_mtu \|\| mtu > dev->max_mtu)
	255	dev->mtu = ETH_DATA_LEN - overhead;
	256	else
1f5cd2a0	257	dev->mtu = mtu;
e9697e2e	258
b784e7eb P	259	dev->needed_headroom += session->hdr_len;
	260	}
	261
f026bc29 GN	262	static int l2tp_eth_create(struct net net, struct l2tp_tunnel tunnel,
	263	u32 session_id, u32 peer_session_id,
	264	struct l2tp_session_cfg *cfg)
d9e31d17	265	{
c39855fe	266	unsigned char name_assign_type;
d9e31d17 JC	267	struct net_device *dev;
d9e31d17 JC	268	char name[IFNAMSIZ];
d9e31d17 JC	269	struct l2tp_session *session;
	270	struct l2tp_eth *priv;
	271	struct l2tp_eth_sess *spriv;
	272	int rc;
d9e31d17	273
d9e31d17	274	if (cfg->ifname) {
d9e31d17	275	strlcpy(name, cfg->ifname, IFNAMSIZ);
c39855fe GN	276	name_assign_type = NET_NAME_USER;
c39855fe GN	277	} else {
d9e31d17	278	strcpy(name, L2TP_ETH_DEV_NAME);
c39855fe GN	279	name_assign_type = NET_NAME_ENUM;
c39855fe GN	280	}
d9e31d17 JC	281
	282	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
	283	peer_session_id, cfg);
dbdbc73b GN	284	if (IS_ERR(session)) {
dbdbc73b GN	285	rc = PTR_ERR(session);
ee28de6b	286	goto err;
3953ae7b GN	287	}
3953ae7b GN	288
c39855fe	289	dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
c835a677	290	l2tp_eth_dev_setup);
d9e31d17 JC	291	if (!dev) {
d9e31d17 JC	292	rc = -ENOMEM;
ee28de6b	293	goto err_sess;
d9e31d17 JC	294	}
	295
	296	dev_net_set(dev, net);
8b1efc0f JW	297	dev->min_mtu = 0;
8b1efc0f JW	298	dev->max_mtu = ETH_MAX_MTU;
b784e7eb	299	l2tp_eth_adjust_mtu(tunnel, session, dev);
d9e31d17 JC	300
d9e31d17 JC	301	priv = netdev_priv(dev);
d9e31d17	302	priv->session = session;
d9e31d17	303
d9e31d17 JC	304	session->recv_skb = l2tp_eth_dev_recv;
d9e31d17 JC	305	session->session_close = l2tp_eth_delete;
c2ebc256 AB	306	if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
c2ebc256 AB	307	session->show = l2tp_eth_show;
d9e31d17 JC	308
d9e31d17 JC	309	spriv = l2tp_session_priv(session);
d9e31d17	310
ee28de6b GN	311	l2tp_session_inc_refcount(session);
	312
	313	rtnl_lock();
	314
	315	/* Register both device and session while holding the rtnl lock. This
	316	* ensures that l2tp_eth_delete() will see that there's a device to
	317	* unregister, even if it happened to run before we assign spriv->dev.
	318	*/
	319	rc = l2tp_session_register(session, tunnel);
	320	if (rc < 0) {
	321	rtnl_unlock();
	322	goto err_sess_dev;
	323	}
	324
	325	rc = register_netdevice(dev);
	326	if (rc < 0) {
	327	rtnl_unlock();
	328	l2tp_session_delete(session);
	329	l2tp_session_dec_refcount(session);
	330	free_netdev(dev);
	331
	332	return rc;
	333	}
d9e31d17	334
d9e31d17	335	strlcpy(session->ifname, dev->name, IFNAMSIZ);
ee28de6b GN	336	rcu_assign_pointer(spriv->dev, dev);
	337
	338	rtnl_unlock();
	339
3953ae7b	340	l2tp_session_dec_refcount(session);
d9e31d17	341
ee28de6b	342	__module_get(THIS_MODULE);
d9e31d17 JC	343
	344	return 0;
	345
ee28de6b	346	err_sess_dev:
3953ae7b	347	l2tp_session_dec_refcount(session);
ee28de6b GN	348	free_netdev(dev);
	349	err_sess:
	350	kfree(session);
	351	err:
d9e31d17 JC	352	return rc;
	353	}
	354
d9e31d17 JC	355
	356	static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
	357	.session_create = l2tp_eth_create,
	358	.session_delete = l2tp_session_delete,
	359	};
	360
	361
	362	static int __init l2tp_eth_init(void)
	363	{
	364	int err = 0;
	365
	366	err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
	367	if (err)
9f775ead	368	goto err;
d9e31d17	369
a4ca44fa	370	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
d9e31d17 JC	371
	372	return 0;
	373
9f775ead	374	err:
d9e31d17 JC	375	return err;
	376	}
	377
	378	static void __exit l2tp_eth_exit(void)
	379	{
d9e31d17 JC	380	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
	381	}
	382
	383	module_init(l2tp_eth_init);
	384	module_exit(l2tp_eth_exit);
	385
	386	MODULE_LICENSE("GPL");
	387	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	388	MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
	389	MODULE_VERSION("1.0");
f1f39f91	390	MODULE_ALIAS_L2TP_PWTYPE(5);