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

// SPDX-License-Identifier: GPL-2.0-or-later
/* L2TPv3 ethernet pseudowire driver
 *
 * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
 */

#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 netdev_tx_t 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);

	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 (!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_ct(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) {
		strscpy(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;
	}

	strscpy(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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
20dcb110	2	/* L2TPv3 ethernet pseudowire driver
d9e31d17 JC	3	*
d9e31d17 JC	4	* Copyright (c) 2008,2009,2010 Katalix Systems Ltd
d9e31d17 JC	5	*/
d9e31d17 JC	6
a4ca44fa JP	7	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a4ca44fa JP	8
d9e31d17 JC	9	#include <linux/module.h>
	10	#include <linux/skbuff.h>
	11	#include <linux/socket.h>
	12	#include <linux/hash.h>
	13	#include <linux/l2tp.h>
	14	#include <linux/in.h>
	15	#include <linux/etherdevice.h>
	16	#include <linux/spinlock.h>
	17	#include <net/sock.h>
	18	#include <net/ip.h>
	19	#include <net/icmp.h>
	20	#include <net/udp.h>
	21	#include <net/inet_common.h>
	22	#include <net/inet_hashtables.h>
	23	#include <net/tcp_states.h>
	24	#include <net/protocol.h>
	25	#include <net/xfrm.h>
	26	#include <net/net_namespace.h>
	27	#include <net/netns/generic.h>
b784e7eb P	28	#include <linux/ip.h>
	29	#include <linux/ipv6.h>
	30	#include <linux/udp.h>
d9e31d17 JC	31
	32	#include "l2tp_core.h"
	33
	34	/* Default device name. May be overridden by name specified by user */
	35	#define L2TP_ETH_DEV_NAME "l2tpeth%d"
	36
	37	/* via netdev_priv() */
	38	struct l2tp_eth {
d9e31d17	39	struct l2tp_session *session;
a2842a1e ED	40	atomic_long_t tx_bytes;
a2842a1e ED	41	atomic_long_t tx_packets;
b8c84307	42	atomic_long_t tx_dropped;
a2842a1e ED	43	atomic_long_t rx_bytes;
	44	atomic_long_t rx_packets;
	45	atomic_long_t rx_errors;
d9e31d17 JC	46	};
	47
	48	/* via l2tp_session_priv() */
	49	struct l2tp_eth_sess {
ee28de6b	50	struct net_device __rcu *dev;
d9e31d17 JC	51	};
d9e31d17 JC	52
d9e31d17 JC	53	static int l2tp_eth_dev_init(struct net_device *dev)
d9e31d17 JC	54	{
f2cedb63	55	eth_hw_addr_random(dev);
1cea7e2c	56	eth_broadcast_addr(dev->broadcast);
1a33e10e	57	netdev_lockdep_set_classes(dev);
f9eb8aea	58
d9e31d17 JC	59	return 0;
	60	}
	61
	62	static void l2tp_eth_dev_uninit(struct net_device *dev)
	63	{
ee28de6b GN	64	struct l2tp_eth *priv = netdev_priv(dev);
	65	struct l2tp_eth_sess *spriv;
	66
	67	spriv = l2tp_session_priv(priv->session);
	68	RCU_INIT_POINTER(spriv->dev, NULL);
	69	/* No need for synchronize_net() here. We're called by
	70	* unregister_netdev*(), which does the synchronisation for us.
	71	*/
d9e31d17 JC	72	}
d9e31d17 JC	73
433f17a9	74	static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff skb, struct net_device dev)
d9e31d17 JC	75	{
	76	struct l2tp_eth *priv = netdev_priv(dev);
	77	struct l2tp_session *session = priv->session;
b8c84307	78	unsigned int len = skb->len;
efe05278	79	int ret = l2tp_xmit_skb(session, skb);
b8c84307	80
a4cd0271	81	if (likely(ret == NET_XMIT_SUCCESS)) {
b8c84307 ED	82	atomic_long_add(len, &priv->tx_bytes);
	83	atomic_long_inc(&priv->tx_packets);
	84	} else {
	85	atomic_long_inc(&priv->tx_dropped);
	86	}
aa214de0	87	return NETDEV_TX_OK;
d9e31d17 JC	88	}
d9e31d17 JC	89
bc1f4470	90	static void l2tp_eth_get_stats64(struct net_device *dev,
bc1f4470	91	struct rtnl_link_stats64 *stats)
a2842a1e ED	92	{
	93	struct l2tp_eth *priv = netdev_priv(dev);
	94
b71a61cc TP	95	stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes);
	96	stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets);
	97	stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped);
	98	stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes);
	99	stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets);
	100	stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors);
a2842a1e ED	101	}
a2842a1e ED	102
eb94737d	103	static const struct net_device_ops l2tp_eth_netdev_ops = {
d9e31d17 JC	104	.ndo_init = l2tp_eth_dev_init,
	105	.ndo_uninit = l2tp_eth_dev_uninit,
	106	.ndo_start_xmit = l2tp_eth_dev_xmit,
a2842a1e	107	.ndo_get_stats64 = l2tp_eth_get_stats64,
fe159122	108	.ndo_set_mac_address = eth_mac_addr,
d9e31d17 JC	109	};
d9e31d17 JC	110
a485c2b8 GN	111	static struct device_type l2tpeth_type = {
	112	.name = "l2tpeth",
	113	};
	114
d9e31d17 JC	115	static void l2tp_eth_dev_setup(struct net_device *dev)
d9e31d17 JC	116	{
a485c2b8	117	SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
d9e31d17	118	ether_setup(dev);
a2842a1e ED	119	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
a2842a1e ED	120	dev->features \|= NETIF_F_LLTX;
d9e31d17	121	dev->netdev_ops = &l2tp_eth_netdev_ops;
cf124db5	122	dev->needs_free_netdev = true;
d9e31d17 JC	123	}
	124
	125	static void l2tp_eth_dev_recv(struct l2tp_session session, struct sk_buff skb, int data_len)
	126	{
	127	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	128	struct net_device *dev;
ee28de6b GN	129	struct l2tp_eth *priv;
d9e31d17	130
c0cc88a7	131	if (!pskb_may_pull(skb, ETH_HLEN))
d9e31d17 JC	132	goto error;
	133
	134	secpath_reset(skb);
	135
	136	/* checksums verified by L2TP */
	137	skb->ip_summed = CHECKSUM_NONE;
	138
	139	skb_dst_drop(skb);
895b5c9f	140	nf_reset_ct(skb);
d9e31d17	141
ee28de6b GN	142	rcu_read_lock();
	143	dev = rcu_dereference(spriv->dev);
	144	if (!dev)
	145	goto error_rcu;
	146
	147	priv = netdev_priv(dev);
d9e31d17	148	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
a2842a1e ED	149	atomic_long_inc(&priv->rx_packets);
	150	atomic_long_add(data_len, &priv->rx_bytes);
	151	} else {
	152	atomic_long_inc(&priv->rx_errors);
	153	}
ee28de6b GN	154	rcu_read_unlock();
ee28de6b GN	155
d9e31d17 JC	156	return;
d9e31d17 JC	157
ee28de6b GN	158	error_rcu:
ee28de6b GN	159	rcu_read_unlock();
d9e31d17	160	error:
d9e31d17 JC	161	kfree_skb(skb);
	162	}
	163
	164	static void l2tp_eth_delete(struct l2tp_session *session)
	165	{
	166	struct l2tp_eth_sess *spriv;
	167	struct net_device *dev;
	168
	169	if (session) {
	170	spriv = l2tp_session_priv(session);
ee28de6b GN	171
	172	rtnl_lock();
	173	dev = rtnl_dereference(spriv->dev);
d9e31d17	174	if (dev) {
ee28de6b GN	175	unregister_netdevice(dev);
ee28de6b GN	176	rtnl_unlock();
a06998b8	177	module_put(THIS_MODULE);
ee28de6b GN	178	} else {
ee28de6b GN	179	rtnl_unlock();
d9e31d17 JC	180	}
	181	}
	182	}
	183
0ad66140 JC	184	static void l2tp_eth_show(struct seq_file m, void arg)
	185	{
	186	struct l2tp_session *session = arg;
	187	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	188	struct net_device *dev;
	189
	190	rcu_read_lock();
	191	dev = rcu_dereference(spriv->dev);
	192	if (!dev) {
	193	rcu_read_unlock();
	194	return;
	195	}
	196	dev_hold(dev);
	197	rcu_read_unlock();
0ad66140 JC	198
0ad66140 JC	199	seq_printf(m, " interface %s\n", dev->name);
ee28de6b GN	200
ee28de6b GN	201	dev_put(dev);
0ad66140	202	}
0ad66140	203
b784e7eb P	204	static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
	205	struct l2tp_session *session,
	206	struct net_device *dev)
	207	{
	208	unsigned int overhead = 0;
b784e7eb	209	u32 l3_overhead = 0;
1f5cd2a0	210	u32 mtu;
b784e7eb P	211
	212	/* if the encap is UDP, account for UDP header size */
	213	if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
	214	overhead += sizeof(struct udphdr);
	215	dev->needed_headroom += sizeof(struct udphdr);
	216	}
e9697e2e	217
57240d00	218	lock_sock(tunnel->sock);
b784e7eb	219	l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
57240d00	220	release_sock(tunnel->sock);
e9697e2e	221
b784e7eb P	222	if (l3_overhead == 0) {
	223	/* L3 Overhead couldn't be identified, this could be
	224	* because tunnel->sock was NULL or the socket's
	225	* address family was not IPv4 or IPv6,
	226	* dev mtu stays at 1500.
	227	*/
	228	return;
	229	}
	230	/* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
	231	* UDP overhead, if any, was already factored in above.
	232	*/
	233	overhead += session->hdr_len + ETH_HLEN + l3_overhead;
	234
e9697e2e GN	235	mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
	236	if (mtu < dev->min_mtu \|\| mtu > dev->max_mtu)
	237	dev->mtu = ETH_DATA_LEN - overhead;
	238	else
1f5cd2a0	239	dev->mtu = mtu;
e9697e2e	240
b784e7eb P	241	dev->needed_headroom += session->hdr_len;
	242	}
	243
f026bc29 GN	244	static int l2tp_eth_create(struct net net, struct l2tp_tunnel tunnel,
	245	u32 session_id, u32 peer_session_id,
	246	struct l2tp_session_cfg *cfg)
d9e31d17	247	{
c39855fe	248	unsigned char name_assign_type;
d9e31d17 JC	249	struct net_device *dev;
d9e31d17 JC	250	char name[IFNAMSIZ];
d9e31d17 JC	251	struct l2tp_session *session;
	252	struct l2tp_eth *priv;
	253	struct l2tp_eth_sess *spriv;
	254	int rc;
d9e31d17	255
d9e31d17	256	if (cfg->ifname) {
a5afe530	257	strscpy(name, cfg->ifname, IFNAMSIZ);
c39855fe GN	258	name_assign_type = NET_NAME_USER;
c39855fe GN	259	} else {
d9e31d17	260	strcpy(name, L2TP_ETH_DEV_NAME);
c39855fe GN	261	name_assign_type = NET_NAME_ENUM;
c39855fe GN	262	}
d9e31d17 JC	263
	264	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
	265	peer_session_id, cfg);
dbdbc73b GN	266	if (IS_ERR(session)) {
dbdbc73b GN	267	rc = PTR_ERR(session);
ee28de6b	268	goto err;
3953ae7b GN	269	}
3953ae7b GN	270
c39855fe	271	dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
c835a677	272	l2tp_eth_dev_setup);
d9e31d17 JC	273	if (!dev) {
d9e31d17 JC	274	rc = -ENOMEM;
ee28de6b	275	goto err_sess;
d9e31d17 JC	276	}
	277
	278	dev_net_set(dev, net);
8b1efc0f JW	279	dev->min_mtu = 0;
8b1efc0f JW	280	dev->max_mtu = ETH_MAX_MTU;
b784e7eb	281	l2tp_eth_adjust_mtu(tunnel, session, dev);
d9e31d17 JC	282
d9e31d17 JC	283	priv = netdev_priv(dev);
d9e31d17	284	priv->session = session;
d9e31d17	285
d9e31d17 JC	286	session->recv_skb = l2tp_eth_dev_recv;
d9e31d17 JC	287	session->session_close = l2tp_eth_delete;
c2ebc256 AB	288	if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
c2ebc256 AB	289	session->show = l2tp_eth_show;
d9e31d17 JC	290
d9e31d17 JC	291	spriv = l2tp_session_priv(session);
d9e31d17	292
ee28de6b GN	293	l2tp_session_inc_refcount(session);
	294
	295	rtnl_lock();
	296
	297	/* Register both device and session while holding the rtnl lock. This
	298	* ensures that l2tp_eth_delete() will see that there's a device to
	299	* unregister, even if it happened to run before we assign spriv->dev.
	300	*/
	301	rc = l2tp_session_register(session, tunnel);
	302	if (rc < 0) {
	303	rtnl_unlock();
	304	goto err_sess_dev;
	305	}
	306
	307	rc = register_netdevice(dev);
	308	if (rc < 0) {
	309	rtnl_unlock();
	310	l2tp_session_delete(session);
	311	l2tp_session_dec_refcount(session);
	312	free_netdev(dev);
	313
	314	return rc;
	315	}
d9e31d17	316
a5afe530	317	strscpy(session->ifname, dev->name, IFNAMSIZ);
ee28de6b GN	318	rcu_assign_pointer(spriv->dev, dev);
	319
	320	rtnl_unlock();
	321
3953ae7b	322	l2tp_session_dec_refcount(session);
d9e31d17	323
ee28de6b	324	__module_get(THIS_MODULE);
d9e31d17 JC	325
	326	return 0;
	327
ee28de6b	328	err_sess_dev:
3953ae7b	329	l2tp_session_dec_refcount(session);
ee28de6b GN	330	free_netdev(dev);
	331	err_sess:
	332	kfree(session);
	333	err:
d9e31d17 JC	334	return rc;
	335	}
	336
d9e31d17 JC	337	static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
	338	.session_create = l2tp_eth_create,
	339	.session_delete = l2tp_session_delete,
	340	};
	341
d9e31d17 JC	342	static int __init l2tp_eth_init(void)
	343	{
	344	int err = 0;
	345
	346	err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
	347	if (err)
9f775ead	348	goto err;
d9e31d17	349
a4ca44fa	350	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
d9e31d17 JC	351
	352	return 0;
	353
9f775ead	354	err:
d9e31d17 JC	355	return err;
	356	}
	357
	358	static void __exit l2tp_eth_exit(void)
	359	{
d9e31d17 JC	360	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
	361	}
	362
	363	module_init(l2tp_eth_init);
	364	module_exit(l2tp_eth_exit);
	365
	366	MODULE_LICENSE("GPL");
	367	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	368	MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
	369	MODULE_VERSION("1.0");
f1f39f91	370	MODULE_ALIAS_L2TP_PWTYPE(5);