[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);

	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_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) {
		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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
d9e31d17 JC	2	/*
	3	* L2TPv3 ethernet pseudowire driver
	4	*
	5	* Copyright (c) 2008,2009,2010 Katalix Systems Ltd
d9e31d17 JC	6	*/
d9e31d17 JC	7
a4ca44fa JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a4ca44fa JP	9
d9e31d17 JC	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
	12	#include <linux/socket.h>
	13	#include <linux/hash.h>
	14	#include <linux/l2tp.h>
	15	#include <linux/in.h>
	16	#include <linux/etherdevice.h>
	17	#include <linux/spinlock.h>
	18	#include <net/sock.h>
	19	#include <net/ip.h>
	20	#include <net/icmp.h>
	21	#include <net/udp.h>
	22	#include <net/inet_common.h>
	23	#include <net/inet_hashtables.h>
	24	#include <net/tcp_states.h>
	25	#include <net/protocol.h>
	26	#include <net/xfrm.h>
	27	#include <net/net_namespace.h>
	28	#include <net/netns/generic.h>
b784e7eb P	29	#include <linux/ip.h>
	30	#include <linux/ipv6.h>
	31	#include <linux/udp.h>
d9e31d17 JC	32
	33	#include "l2tp_core.h"
	34
	35	/* Default device name. May be overridden by name specified by user */
	36	#define L2TP_ETH_DEV_NAME "l2tpeth%d"
	37
	38	/* via netdev_priv() */
	39	struct l2tp_eth {
d9e31d17	40	struct l2tp_session *session;
a2842a1e ED	41	atomic_long_t tx_bytes;
a2842a1e ED	42	atomic_long_t tx_packets;
b8c84307	43	atomic_long_t tx_dropped;
a2842a1e ED	44	atomic_long_t rx_bytes;
	45	atomic_long_t rx_packets;
	46	atomic_long_t rx_errors;
d9e31d17 JC	47	};
	48
	49	/* via l2tp_session_priv() */
	50	struct l2tp_eth_sess {
ee28de6b	51	struct net_device __rcu *dev;
d9e31d17 JC	52	};
d9e31d17 JC	53
d9e31d17 JC	54
	55	static int l2tp_eth_dev_init(struct net_device *dev)
	56	{
f2cedb63	57	eth_hw_addr_random(dev);
1cea7e2c	58	eth_broadcast_addr(dev->broadcast);
f9eb8aea	59
d9e31d17 JC	60	return 0;
	61	}
	62
	63	static void l2tp_eth_dev_uninit(struct net_device *dev)
	64	{
ee28de6b GN	65	struct l2tp_eth *priv = netdev_priv(dev);
	66	struct l2tp_eth_sess *spriv;
	67
	68	spriv = l2tp_session_priv(priv->session);
	69	RCU_INIT_POINTER(spriv->dev, NULL);
	70	/* No need for synchronize_net() here. We're called by
	71	* unregister_netdev*(), which does the synchronisation for us.
	72	*/
d9e31d17 JC	73	}
	74
	75	static int l2tp_eth_dev_xmit(struct sk_buff skb, struct net_device dev)
	76	{
	77	struct l2tp_eth *priv = netdev_priv(dev);
	78	struct l2tp_session *session = priv->session;
b8c84307 ED	79	unsigned int len = skb->len;
	80	int ret = l2tp_xmit_skb(session, skb, session->hdr_len);
	81
a4cd0271	82	if (likely(ret == NET_XMIT_SUCCESS)) {
b8c84307 ED	83	atomic_long_add(len, &priv->tx_bytes);
	84	atomic_long_inc(&priv->tx_packets);
	85	} else {
	86	atomic_long_inc(&priv->tx_dropped);
	87	}
aa214de0	88	return NETDEV_TX_OK;
d9e31d17 JC	89	}
d9e31d17 JC	90
bc1f4470	91	static void l2tp_eth_get_stats64(struct net_device *dev,
bc1f4470	92	struct rtnl_link_stats64 *stats)
a2842a1e ED	93	{
	94	struct l2tp_eth *priv = netdev_priv(dev);
	95
9b3dc0a1 DH	96	stats->tx_bytes = (unsigned long) atomic_long_read(&priv->tx_bytes);
	97	stats->tx_packets = (unsigned long) atomic_long_read(&priv->tx_packets);
	98	stats->tx_dropped = (unsigned long) atomic_long_read(&priv->tx_dropped);
	99	stats->rx_bytes = (unsigned long) atomic_long_read(&priv->rx_bytes);
	100	stats->rx_packets = (unsigned long) atomic_long_read(&priv->rx_packets);
	101	stats->rx_errors = (unsigned long) atomic_long_read(&priv->rx_errors);
	102
a2842a1e ED	103	}
a2842a1e ED	104
eb94737d	105	static const struct net_device_ops l2tp_eth_netdev_ops = {
d9e31d17 JC	106	.ndo_init = l2tp_eth_dev_init,
	107	.ndo_uninit = l2tp_eth_dev_uninit,
	108	.ndo_start_xmit = l2tp_eth_dev_xmit,
a2842a1e	109	.ndo_get_stats64 = l2tp_eth_get_stats64,
fe159122	110	.ndo_set_mac_address = eth_mac_addr,
d9e31d17 JC	111	};
d9e31d17 JC	112
a485c2b8 GN	113	static struct device_type l2tpeth_type = {
	114	.name = "l2tpeth",
	115	};
	116
d9e31d17 JC	117	static void l2tp_eth_dev_setup(struct net_device *dev)
d9e31d17 JC	118	{
a485c2b8	119	SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
d9e31d17	120	ether_setup(dev);
a2842a1e ED	121	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
a2842a1e ED	122	dev->features \|= NETIF_F_LLTX;
d9e31d17	123	dev->netdev_ops = &l2tp_eth_netdev_ops;
cf124db5	124	dev->needs_free_netdev = true;
d9e31d17 JC	125	}
	126
	127	static void l2tp_eth_dev_recv(struct l2tp_session session, struct sk_buff skb, int data_len)
	128	{
	129	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	130	struct net_device *dev;
ee28de6b GN	131	struct l2tp_eth *priv;
d9e31d17 JC	132
	133	if (session->debug & L2TP_MSG_DATA) {
	134	unsigned int length;
d9e31d17 JC	135
	136	length = min(32u, skb->len);
	137	if (!pskb_may_pull(skb, length))
	138	goto error;
	139
a4ca44fa	140	pr_debug("%s: eth recv\n", session->name);
a2842a1e	141	print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
d9e31d17 JC	142	}
d9e31d17 JC	143
c0cc88a7	144	if (!pskb_may_pull(skb, ETH_HLEN))
d9e31d17 JC	145	goto error;
	146
	147	secpath_reset(skb);
	148
	149	/* checksums verified by L2TP */
	150	skb->ip_summed = CHECKSUM_NONE;
	151
	152	skb_dst_drop(skb);
895b5c9f	153	nf_reset_ct(skb);
d9e31d17	154
ee28de6b GN	155	rcu_read_lock();
	156	dev = rcu_dereference(spriv->dev);
	157	if (!dev)
	158	goto error_rcu;
	159
	160	priv = netdev_priv(dev);
d9e31d17	161	if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
a2842a1e ED	162	atomic_long_inc(&priv->rx_packets);
	163	atomic_long_add(data_len, &priv->rx_bytes);
	164	} else {
	165	atomic_long_inc(&priv->rx_errors);
	166	}
ee28de6b GN	167	rcu_read_unlock();
ee28de6b GN	168
d9e31d17 JC	169	return;
d9e31d17 JC	170
ee28de6b GN	171	error_rcu:
ee28de6b GN	172	rcu_read_unlock();
d9e31d17	173	error:
d9e31d17 JC	174	kfree_skb(skb);
	175	}
	176
	177	static void l2tp_eth_delete(struct l2tp_session *session)
	178	{
	179	struct l2tp_eth_sess *spriv;
	180	struct net_device *dev;
	181
	182	if (session) {
	183	spriv = l2tp_session_priv(session);
ee28de6b GN	184
	185	rtnl_lock();
	186	dev = rtnl_dereference(spriv->dev);
d9e31d17	187	if (dev) {
ee28de6b GN	188	unregister_netdevice(dev);
ee28de6b GN	189	rtnl_unlock();
a06998b8	190	module_put(THIS_MODULE);
ee28de6b GN	191	} else {
ee28de6b GN	192	rtnl_unlock();
d9e31d17 JC	193	}
	194	}
	195	}
	196
0ad66140 JC	197	static void l2tp_eth_show(struct seq_file m, void arg)
	198	{
	199	struct l2tp_session *session = arg;
	200	struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
ee28de6b GN	201	struct net_device *dev;
	202
	203	rcu_read_lock();
	204	dev = rcu_dereference(spriv->dev);
	205	if (!dev) {
	206	rcu_read_unlock();
	207	return;
	208	}
	209	dev_hold(dev);
	210	rcu_read_unlock();
0ad66140 JC	211
0ad66140 JC	212	seq_printf(m, " interface %s\n", dev->name);
ee28de6b GN	213
ee28de6b GN	214	dev_put(dev);
0ad66140	215	}
0ad66140	216
b784e7eb P	217	static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
	218	struct l2tp_session *session,
	219	struct net_device *dev)
	220	{
	221	unsigned int overhead = 0;
b784e7eb	222	u32 l3_overhead = 0;
1f5cd2a0	223	u32 mtu;
b784e7eb P	224
	225	/* if the encap is UDP, account for UDP header size */
	226	if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
	227	overhead += sizeof(struct udphdr);
	228	dev->needed_headroom += sizeof(struct udphdr);
	229	}
e9697e2e	230
57240d00	231	lock_sock(tunnel->sock);
b784e7eb	232	l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
57240d00	233	release_sock(tunnel->sock);
e9697e2e	234
b784e7eb P	235	if (l3_overhead == 0) {
	236	/* L3 Overhead couldn't be identified, this could be
	237	* because tunnel->sock was NULL or the socket's
	238	* address family was not IPv4 or IPv6,
	239	* dev mtu stays at 1500.
	240	*/
	241	return;
	242	}
	243	/* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
	244	* UDP overhead, if any, was already factored in above.
	245	*/
	246	overhead += session->hdr_len + ETH_HLEN + l3_overhead;
	247
e9697e2e GN	248	mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
	249	if (mtu < dev->min_mtu \|\| mtu > dev->max_mtu)
	250	dev->mtu = ETH_DATA_LEN - overhead;
	251	else
1f5cd2a0	252	dev->mtu = mtu;
e9697e2e	253
b784e7eb P	254	dev->needed_headroom += session->hdr_len;
	255	}
	256
f026bc29 GN	257	static int l2tp_eth_create(struct net net, struct l2tp_tunnel tunnel,
	258	u32 session_id, u32 peer_session_id,
	259	struct l2tp_session_cfg *cfg)
d9e31d17	260	{
c39855fe	261	unsigned char name_assign_type;
d9e31d17 JC	262	struct net_device *dev;
d9e31d17 JC	263	char name[IFNAMSIZ];
d9e31d17 JC	264	struct l2tp_session *session;
	265	struct l2tp_eth *priv;
	266	struct l2tp_eth_sess *spriv;
	267	int rc;
d9e31d17	268
d9e31d17	269	if (cfg->ifname) {
d9e31d17	270	strlcpy(name, cfg->ifname, IFNAMSIZ);
c39855fe GN	271	name_assign_type = NET_NAME_USER;
c39855fe GN	272	} else {
d9e31d17	273	strcpy(name, L2TP_ETH_DEV_NAME);
c39855fe GN	274	name_assign_type = NET_NAME_ENUM;
c39855fe GN	275	}
d9e31d17 JC	276
	277	session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
	278	peer_session_id, cfg);
dbdbc73b GN	279	if (IS_ERR(session)) {
dbdbc73b GN	280	rc = PTR_ERR(session);
ee28de6b	281	goto err;
3953ae7b GN	282	}
3953ae7b GN	283
c39855fe	284	dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
c835a677	285	l2tp_eth_dev_setup);
d9e31d17 JC	286	if (!dev) {
d9e31d17 JC	287	rc = -ENOMEM;
ee28de6b	288	goto err_sess;
d9e31d17 JC	289	}
	290
	291	dev_net_set(dev, net);
8b1efc0f JW	292	dev->min_mtu = 0;
8b1efc0f JW	293	dev->max_mtu = ETH_MAX_MTU;
b784e7eb	294	l2tp_eth_adjust_mtu(tunnel, session, dev);
d9e31d17 JC	295
d9e31d17 JC	296	priv = netdev_priv(dev);
d9e31d17	297	priv->session = session;
d9e31d17	298
d9e31d17 JC	299	session->recv_skb = l2tp_eth_dev_recv;
d9e31d17 JC	300	session->session_close = l2tp_eth_delete;
c2ebc256 AB	301	if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
c2ebc256 AB	302	session->show = l2tp_eth_show;
d9e31d17 JC	303
d9e31d17 JC	304	spriv = l2tp_session_priv(session);
d9e31d17	305
ee28de6b GN	306	l2tp_session_inc_refcount(session);
	307
	308	rtnl_lock();
	309
	310	/* Register both device and session while holding the rtnl lock. This
	311	* ensures that l2tp_eth_delete() will see that there's a device to
	312	* unregister, even if it happened to run before we assign spriv->dev.
	313	*/
	314	rc = l2tp_session_register(session, tunnel);
	315	if (rc < 0) {
	316	rtnl_unlock();
	317	goto err_sess_dev;
	318	}
	319
	320	rc = register_netdevice(dev);
	321	if (rc < 0) {
	322	rtnl_unlock();
	323	l2tp_session_delete(session);
	324	l2tp_session_dec_refcount(session);
	325	free_netdev(dev);
	326
	327	return rc;
	328	}
d9e31d17	329
d9e31d17	330	strlcpy(session->ifname, dev->name, IFNAMSIZ);
ee28de6b GN	331	rcu_assign_pointer(spriv->dev, dev);
	332
	333	rtnl_unlock();
	334
3953ae7b	335	l2tp_session_dec_refcount(session);
d9e31d17	336
ee28de6b	337	__module_get(THIS_MODULE);
d9e31d17 JC	338
	339	return 0;
	340
ee28de6b	341	err_sess_dev:
3953ae7b	342	l2tp_session_dec_refcount(session);
ee28de6b GN	343	free_netdev(dev);
	344	err_sess:
	345	kfree(session);
	346	err:
d9e31d17 JC	347	return rc;
	348	}
	349
d9e31d17 JC	350
	351	static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
	352	.session_create = l2tp_eth_create,
	353	.session_delete = l2tp_session_delete,
	354	};
	355
	356
	357	static int __init l2tp_eth_init(void)
	358	{
	359	int err = 0;
	360
	361	err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
	362	if (err)
9f775ead	363	goto err;
d9e31d17	364
a4ca44fa	365	pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
d9e31d17 JC	366
	367	return 0;
	368
9f775ead	369	err:
d9e31d17 JC	370	return err;
	371	}
	372
	373	static void __exit l2tp_eth_exit(void)
	374	{
d9e31d17 JC	375	l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
	376	}
	377
	378	module_init(l2tp_eth_init);
	379	module_exit(l2tp_eth_exit);
	380
	381	MODULE_LICENSE("GPL");
	382	MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
	383	MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
	384	MODULE_VERSION("1.0");
f1f39f91	385	MODULE_ALIAS_L2TP_PWTYPE(5);