[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / net / veth.c

/*
 *  drivers/net/veth.c
 *
 *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
 *
 * Author: Pavel Emelianov <xemul@openvz.org>
 * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
 *
 */

#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/ethtool.h>
#include <linux/etherdevice.h>
#include <linux/u64_stats_sync.h>

#include <net/dst.h>
#include <net/xfrm.h>
#include <linux/veth.h>
#include <linux/module.h>

#define DRV_NAME	"veth"
#define DRV_VERSION	"1.0"

#define MIN_MTU 68		/* Min L3 MTU */
#define MAX_MTU 65535		/* Max L3 MTU (arbitrary) */

struct pcpu_vstats {
	u64			packets;
	u64			bytes;
	struct u64_stats_sync	syncp;
};

struct veth_priv {
	struct net_device __rcu	*peer;
	atomic64_t		dropped;
};

/*
 * ethtool interface
 */

static struct {
	const char string[ETH_GSTRING_LEN];
} ethtool_stats_keys[] = {
	{ "peer_ifindex" },
};

static int veth_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
	cmd->supported		= 0;
	cmd->advertising	= 0;
	ethtool_cmd_speed_set(cmd, SPEED_10000);
	cmd->duplex		= DUPLEX_FULL;
	cmd->port		= PORT_TP;
	cmd->phy_address	= 0;
	cmd->transceiver	= XCVR_INTERNAL;
	cmd->autoneg		= AUTONEG_DISABLE;
	cmd->maxtxpkt		= 0;
	cmd->maxrxpkt		= 0;
	return 0;
}

static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
}

static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
{
	switch(stringset) {
	case ETH_SS_STATS:
		memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
		break;
	}
}

static int veth_get_sset_count(struct net_device *dev, int sset)
{
	switch (sset) {
	case ETH_SS_STATS:
		return ARRAY_SIZE(ethtool_stats_keys);
	default:
		return -EOPNOTSUPP;
	}
}

static void veth_get_ethtool_stats(struct net_device *dev,
		struct ethtool_stats *stats, u64 *data)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer = rtnl_dereference(priv->peer);

	data[0] = peer ? peer->ifindex : 0;
}

static const struct ethtool_ops veth_ethtool_ops = {
	.get_settings		= veth_get_settings,
	.get_drvinfo		= veth_get_drvinfo,
	.get_link		= ethtool_op_get_link,
	.get_strings		= veth_get_strings,
	.get_sset_count		= veth_get_sset_count,
	.get_ethtool_stats	= veth_get_ethtool_stats,
};

static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *rcv;
	int length = skb->len;

	rcu_read_lock();
	rcv = rcu_dereference(priv->peer);
	if (unlikely(!rcv)) {
		kfree_skb(skb);
		goto drop;
	}

	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
		struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);

		u64_stats_update_begin(&stats->syncp);
		stats->bytes += length;
		stats->packets++;
		u64_stats_update_end(&stats->syncp);
	} else {
drop:
		atomic64_inc(&priv->dropped);
	}
	rcu_read_unlock();
	return NETDEV_TX_OK;
}

/*
 * general routines
 */

static u64 veth_stats_one(struct pcpu_vstats *result, struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	int cpu;

	result->packets = 0;
	result->bytes = 0;
	for_each_possible_cpu(cpu) {
		struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
		u64 packets, bytes;
		unsigned int start;

		do {
			start = u64_stats_fetch_begin_bh(&stats->syncp);
			packets = stats->packets;
			bytes = stats->bytes;
		} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
		result->packets += packets;
		result->bytes += bytes;
	}
	return atomic64_read(&priv->dropped);
}

static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
						  struct rtnl_link_stats64 *tot)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer;
	struct pcpu_vstats one;

	tot->tx_dropped = veth_stats_one(&one, dev);
	tot->tx_bytes = one.bytes;
	tot->tx_packets = one.packets;

	rcu_read_lock();
	peer = rcu_dereference(priv->peer);
	if (peer) {
		tot->rx_dropped = veth_stats_one(&one, peer);
		tot->rx_bytes = one.bytes;
		tot->rx_packets = one.packets;
	}
	rcu_read_unlock();

	return tot;
}

static int veth_open(struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer = rtnl_dereference(priv->peer);

	if (!peer)
		return -ENOTCONN;

	if (peer->flags & IFF_UP) {
		netif_carrier_on(dev);
		netif_carrier_on(peer);
	}
	return 0;
}

static int veth_close(struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer = rtnl_dereference(priv->peer);

	netif_carrier_off(dev);
	if (peer)
		netif_carrier_off(peer);

	return 0;
}

static int is_valid_veth_mtu(int new_mtu)
{
	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
}

static int veth_change_mtu(struct net_device *dev, int new_mtu)
{
	if (!is_valid_veth_mtu(new_mtu))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

static int veth_dev_init(struct net_device *dev)
{
	dev->vstats = alloc_percpu(struct pcpu_vstats);
	if (!dev->vstats)
		return -ENOMEM;

	return 0;
}

static void veth_dev_free(struct net_device *dev)
{
	free_percpu(dev->vstats);
	free_netdev(dev);
}

static const struct net_device_ops veth_netdev_ops = {
	.ndo_init            = veth_dev_init,
	.ndo_open            = veth_open,
	.ndo_stop            = veth_close,
	.ndo_start_xmit      = veth_xmit,
	.ndo_change_mtu      = veth_change_mtu,
	.ndo_get_stats64     = veth_get_stats64,
	.ndo_set_mac_address = eth_mac_addr,
};

#define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_ALL_TSO |    \
		       NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_HIGHDMA | \
		       NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
		       NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )

static void veth_setup(struct net_device *dev)
{
	ether_setup(dev);

	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;

	dev->netdev_ops = &veth_netdev_ops;
	dev->ethtool_ops = &veth_ethtool_ops;
	dev->features |= NETIF_F_LLTX;
	dev->features |= VETH_FEATURES;
	dev->destructor = veth_dev_free;

	dev->hw_features = VETH_FEATURES;
}

/*
 * netlink interface
 */

static int veth_validate(struct nlattr *tb[], struct nlattr *data[])
{
	if (tb[IFLA_ADDRESS]) {
		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
			return -EINVAL;
		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
			return -EADDRNOTAVAIL;
	}
	if (tb[IFLA_MTU]) {
		if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
			return -EINVAL;
	}
	return 0;
}

static struct rtnl_link_ops veth_link_ops;

static int veth_newlink(struct net *src_net, struct net_device *dev,
			 struct nlattr *tb[], struct nlattr *data[])
{
	int err;
	struct net_device *peer;
	struct veth_priv *priv;
	char ifname[IFNAMSIZ];
	struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
	struct ifinfomsg *ifmp;
	struct net *net;

	/*
	 * create and register peer first
	 */
	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
		struct nlattr *nla_peer;

		nla_peer = data[VETH_INFO_PEER];
		ifmp = nla_data(nla_peer);
		err = nla_parse(peer_tb, IFLA_MAX,
				nla_data(nla_peer) + sizeof(struct ifinfomsg),
				nla_len(nla_peer) - sizeof(struct ifinfomsg),
				ifla_policy);
		if (err < 0)
			return err;

		err = veth_validate(peer_tb, NULL);
		if (err < 0)
			return err;

		tbp = peer_tb;
	} else {
		ifmp = NULL;
		tbp = tb;
	}

	if (tbp[IFLA_IFNAME])
		nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
	else
		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");

	net = rtnl_link_get_net(src_net, tbp);
	if (IS_ERR(net))
		return PTR_ERR(net);

	peer = rtnl_create_link(net, ifname, &veth_link_ops, tbp);
	if (IS_ERR(peer)) {
		put_net(net);
		return PTR_ERR(peer);
	}

	if (tbp[IFLA_ADDRESS] == NULL)
		eth_hw_addr_random(peer);

	if (ifmp && (dev->ifindex != 0))
		peer->ifindex = ifmp->ifi_index;

	err = register_netdevice(peer);
	put_net(net);
	net = NULL;
	if (err < 0)
		goto err_register_peer;

	netif_carrier_off(peer);

	err = rtnl_configure_link(peer, ifmp);
	if (err < 0)
		goto err_configure_peer;

	/*
	 * register dev last
	 *
	 * note, that since we've registered new device the dev's name
	 * should be re-allocated
	 */

	if (tb[IFLA_ADDRESS] == NULL)
		eth_hw_addr_random(dev);

	if (tb[IFLA_IFNAME])
		nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
	else
		snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");

	if (strchr(dev->name, '%')) {
		err = dev_alloc_name(dev, dev->name);
		if (err < 0)
			goto err_alloc_name;
	}

	err = register_netdevice(dev);
	if (err < 0)
		goto err_register_dev;

	netif_carrier_off(dev);

	/*
	 * tie the deviced together
	 */

	priv = netdev_priv(dev);
	rcu_assign_pointer(priv->peer, peer);

	priv = netdev_priv(peer);
	rcu_assign_pointer(priv->peer, dev);
	return 0;

err_register_dev:
	/* nothing to do */
err_alloc_name:
err_configure_peer:
	unregister_netdevice(peer);
	return err;

err_register_peer:
	free_netdev(peer);
	return err;
}

static void veth_dellink(struct net_device *dev, struct list_head *head)
{
	struct veth_priv *priv;
	struct net_device *peer;

	priv = netdev_priv(dev);
	peer = rtnl_dereference(priv->peer);

	/* Note : dellink() is called from default_device_exit_batch(),
	 * before a rcu_synchronize() point. The devices are guaranteed
	 * not being freed before one RCU grace period.
	 */
	RCU_INIT_POINTER(priv->peer, NULL);
	unregister_netdevice_queue(dev, head);

	if (peer) {
		priv = netdev_priv(peer);
		RCU_INIT_POINTER(priv->peer, NULL);
		unregister_netdevice_queue(peer, head);
	}
}

static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },
};

static struct rtnl_link_ops veth_link_ops = {
	.kind		= DRV_NAME,
	.priv_size	= sizeof(struct veth_priv),
	.setup		= veth_setup,
	.validate	= veth_validate,
	.newlink	= veth_newlink,
	.dellink	= veth_dellink,
	.policy		= veth_policy,
	.maxtype	= VETH_INFO_MAX,
};

/*
 * init/fini
 */

static __init int veth_init(void)
{
	return rtnl_link_register(&veth_link_ops);
}

static __exit void veth_exit(void)
{
	rtnl_link_unregister(&veth_link_ops);
}

module_init(veth_init);
module_exit(veth_exit);

MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_RTNL_LINK(DRV_NAME);
Commit	Line	Data
	1	/*
	2	* drivers/net/veth.c
	3	*
	4	* Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
	5	*
	6	* Author: Pavel Emelianov <xemul@openvz.org>
	7	* Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
	8	*
	9	*/
	10
	11	#include <linux/netdevice.h>
	12	#include <linux/slab.h>
	13	#include <linux/ethtool.h>
	14	#include <linux/etherdevice.h>
	15	#include <linux/u64_stats_sync.h>
	16
	17	#include <net/dst.h>
	18	#include <net/xfrm.h>
	19	#include <linux/veth.h>
	20	#include <linux/module.h>
	21
	22	#define DRV_NAME "veth"
	23	#define DRV_VERSION "1.0"
	24
	25	#define MIN_MTU 68 /* Min L3 MTU */
	26	#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */
	27
	28	struct pcpu_vstats {
	29	u64 packets;
	30	u64 bytes;
	31	struct u64_stats_sync syncp;
	32	};
	33
	34	struct veth_priv {
	35	struct net_device __rcu *peer;
	36	atomic64_t dropped;
	37	};
	38
	39	/*
	40	* ethtool interface
	41	*/
	42
	43	static struct {
	44	const char string[ETH_GSTRING_LEN];
	45	} ethtool_stats_keys[] = {
	46	{ "peer_ifindex" },
	47	};
	48
	49	static int veth_get_settings(struct net_device dev, struct ethtool_cmd cmd)
	50	{
	51	cmd->supported = 0;
	52	cmd->advertising = 0;
	53	ethtool_cmd_speed_set(cmd, SPEED_10000);
	54	cmd->duplex = DUPLEX_FULL;
	55	cmd->port = PORT_TP;
	56	cmd->phy_address = 0;
	57	cmd->transceiver = XCVR_INTERNAL;
	58	cmd->autoneg = AUTONEG_DISABLE;
	59	cmd->maxtxpkt = 0;
	60	cmd->maxrxpkt = 0;
	61	return 0;
	62	}
	63
	64	static void veth_get_drvinfo(struct net_device dev, struct ethtool_drvinfo info)
	65	{
	66	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
	67	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
	68	}
	69
	70	static void veth_get_strings(struct net_device dev, u32 stringset, u8 buf)
	71	{
	72	switch(stringset) {
	73	case ETH_SS_STATS:
	74	memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
	75	break;
	76	}
	77	}
	78
	79	static int veth_get_sset_count(struct net_device *dev, int sset)
	80	{
	81	switch (sset) {
	82	case ETH_SS_STATS:
	83	return ARRAY_SIZE(ethtool_stats_keys);
	84	default:
	85	return -EOPNOTSUPP;
	86	}
	87	}
	88
	89	static void veth_get_ethtool_stats(struct net_device *dev,
	90	struct ethtool_stats stats, u64 data)
	91	{
	92	struct veth_priv *priv = netdev_priv(dev);
	93	struct net_device *peer = rtnl_dereference(priv->peer);
	94
	95	data[0] = peer ? peer->ifindex : 0;
	96	}
	97
	98	static const struct ethtool_ops veth_ethtool_ops = {
	99	.get_settings = veth_get_settings,
	100	.get_drvinfo = veth_get_drvinfo,
	101	.get_link = ethtool_op_get_link,
	102	.get_strings = veth_get_strings,
	103	.get_sset_count = veth_get_sset_count,
	104	.get_ethtool_stats = veth_get_ethtool_stats,
	105	};
	106
	107	static netdev_tx_t veth_xmit(struct sk_buff skb, struct net_device dev)
	108	{
	109	struct veth_priv *priv = netdev_priv(dev);
	110	struct net_device *rcv;
	111	int length = skb->len;
	112
	113	rcu_read_lock();
	114	rcv = rcu_dereference(priv->peer);
	115	if (unlikely(!rcv)) {
	116	kfree_skb(skb);
	117	goto drop;
	118	}
	119
	120	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
	121	struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
	122
	123	u64_stats_update_begin(&stats->syncp);
	124	stats->bytes += length;
	125	stats->packets++;
	126	u64_stats_update_end(&stats->syncp);
	127	} else {
	128	drop:
	129	atomic64_inc(&priv->dropped);
	130	}
	131	rcu_read_unlock();
	132	return NETDEV_TX_OK;
	133	}
	134
	135	/*
	136	* general routines
	137	*/
	138
	139	static u64 veth_stats_one(struct pcpu_vstats result, struct net_device dev)
	140	{
	141	struct veth_priv *priv = netdev_priv(dev);
	142	int cpu;
	143
	144	result->packets = 0;
	145	result->bytes = 0;
	146	for_each_possible_cpu(cpu) {
	147	struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
	148	u64 packets, bytes;
	149	unsigned int start;
	150
	151	do {
	152	start = u64_stats_fetch_begin_bh(&stats->syncp);
	153	packets = stats->packets;
	154	bytes = stats->bytes;
	155	} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
	156	result->packets += packets;
	157	result->bytes += bytes;
	158	}
	159	return atomic64_read(&priv->dropped);
	160	}
	161
	162	static struct rtnl_link_stats64 veth_get_stats64(struct net_device dev,
	163	struct rtnl_link_stats64 *tot)
	164	{
	165	struct veth_priv *priv = netdev_priv(dev);
	166	struct net_device *peer;
	167	struct pcpu_vstats one;
	168
	169	tot->tx_dropped = veth_stats_one(&one, dev);
	170	tot->tx_bytes = one.bytes;
	171	tot->tx_packets = one.packets;
	172
	173	rcu_read_lock();
	174	peer = rcu_dereference(priv->peer);
	175	if (peer) {
	176	tot->rx_dropped = veth_stats_one(&one, peer);
	177	tot->rx_bytes = one.bytes;
	178	tot->rx_packets = one.packets;
	179	}
	180	rcu_read_unlock();
	181
	182	return tot;
	183	}
	184
	185	static int veth_open(struct net_device *dev)
	186	{
	187	struct veth_priv *priv = netdev_priv(dev);
	188	struct net_device *peer = rtnl_dereference(priv->peer);
	189
	190	if (!peer)
	191	return -ENOTCONN;
	192
	193	if (peer->flags & IFF_UP) {
	194	netif_carrier_on(dev);
	195	netif_carrier_on(peer);
	196	}
	197	return 0;
	198	}
	199
	200	static int veth_close(struct net_device *dev)
	201	{
	202	struct veth_priv *priv = netdev_priv(dev);
	203	struct net_device *peer = rtnl_dereference(priv->peer);
	204
	205	netif_carrier_off(dev);
	206	if (peer)
	207	netif_carrier_off(peer);
	208
	209	return 0;
	210	}
	211
	212	static int is_valid_veth_mtu(int new_mtu)
	213	{
	214	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
	215	}
	216
	217	static int veth_change_mtu(struct net_device *dev, int new_mtu)
	218	{
	219	if (!is_valid_veth_mtu(new_mtu))
	220	return -EINVAL;
	221	dev->mtu = new_mtu;
	222	return 0;
	223	}
	224
	225	static int veth_dev_init(struct net_device *dev)
	226	{
	227	dev->vstats = alloc_percpu(struct pcpu_vstats);
	228	if (!dev->vstats)
	229	return -ENOMEM;
	230
	231	return 0;
	232	}
	233
	234	static void veth_dev_free(struct net_device *dev)
	235	{
	236	free_percpu(dev->vstats);
	237	free_netdev(dev);
	238	}
	239
	240	static const struct net_device_ops veth_netdev_ops = {
	241	.ndo_init = veth_dev_init,
	242	.ndo_open = veth_open,
	243	.ndo_stop = veth_close,
	244	.ndo_start_xmit = veth_xmit,
	245	.ndo_change_mtu = veth_change_mtu,
	246	.ndo_get_stats64 = veth_get_stats64,
	247	.ndo_set_mac_address = eth_mac_addr,
	248	};
	249
	250	#define VETH_FEATURES (NETIF_F_SG \| NETIF_F_FRAGLIST \| NETIF_F_ALL_TSO \| \
	251	NETIF_F_HW_CSUM \| NETIF_F_RXCSUM \| NETIF_F_HIGHDMA \| \
	252	NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_CTAG_RX \| \
	253	NETIF_F_HW_VLAN_STAG_TX \| NETIF_F_HW_VLAN_STAG_RX )
	254
	255	static void veth_setup(struct net_device *dev)
	256	{
	257	ether_setup(dev);
	258
	259	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	260	dev->priv_flags \|= IFF_LIVE_ADDR_CHANGE;
	261
	262	dev->netdev_ops = &veth_netdev_ops;
	263	dev->ethtool_ops = &veth_ethtool_ops;
	264	dev->features \|= NETIF_F_LLTX;
	265	dev->features \|= VETH_FEATURES;
	266	dev->destructor = veth_dev_free;
	267
	268	dev->hw_features = VETH_FEATURES;
	269	}
	270
	271	/*
	272	* netlink interface
	273	*/
	274
	275	static int veth_validate(struct nlattr tb[], struct nlattr data[])
	276	{
	277	if (tb[IFLA_ADDRESS]) {
	278	if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
	279	return -EINVAL;
	280	if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
	281	return -EADDRNOTAVAIL;
	282	}
	283	if (tb[IFLA_MTU]) {
	284	if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
	285	return -EINVAL;
	286	}
	287	return 0;
	288	}
	289
	290	static struct rtnl_link_ops veth_link_ops;
	291
	292	static int veth_newlink(struct net src_net, struct net_device dev,
	293	struct nlattr tb[], struct nlattr data[])
	294	{
	295	int err;
	296	struct net_device *peer;
	297	struct veth_priv *priv;
	298	char ifname[IFNAMSIZ];
	299	struct nlattr peer_tb[IFLA_MAX + 1], *tbp;
	300	struct ifinfomsg *ifmp;
	301	struct net *net;
	302
	303	/*
	304	* create and register peer first
	305	*/
	306	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
	307	struct nlattr *nla_peer;
	308
	309	nla_peer = data[VETH_INFO_PEER];
	310	ifmp = nla_data(nla_peer);
	311	err = nla_parse(peer_tb, IFLA_MAX,
	312	nla_data(nla_peer) + sizeof(struct ifinfomsg),
	313	nla_len(nla_peer) - sizeof(struct ifinfomsg),
	314	ifla_policy);
	315	if (err < 0)
	316	return err;
	317
	318	err = veth_validate(peer_tb, NULL);
	319	if (err < 0)
	320	return err;
	321
	322	tbp = peer_tb;
	323	} else {
	324	ifmp = NULL;
	325	tbp = tb;
	326	}
	327
	328	if (tbp[IFLA_IFNAME])
	329	nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
	330	else
	331	snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
	332
	333	net = rtnl_link_get_net(src_net, tbp);
	334	if (IS_ERR(net))
	335	return PTR_ERR(net);
	336
	337	peer = rtnl_create_link(net, ifname, &veth_link_ops, tbp);
	338	if (IS_ERR(peer)) {
	339	put_net(net);
	340	return PTR_ERR(peer);
	341	}
	342
	343	if (tbp[IFLA_ADDRESS] == NULL)
	344	eth_hw_addr_random(peer);
	345
	346	if (ifmp && (dev->ifindex != 0))
	347	peer->ifindex = ifmp->ifi_index;
	348
	349	err = register_netdevice(peer);
	350	put_net(net);
	351	net = NULL;
	352	if (err < 0)
	353	goto err_register_peer;
	354
	355	netif_carrier_off(peer);
	356
	357	err = rtnl_configure_link(peer, ifmp);
	358	if (err < 0)
	359	goto err_configure_peer;
	360
	361	/*
	362	* register dev last
	363	*
	364	* note, that since we've registered new device the dev's name
	365	* should be re-allocated
	366	*/
	367
	368	if (tb[IFLA_ADDRESS] == NULL)
	369	eth_hw_addr_random(dev);
	370
	371	if (tb[IFLA_IFNAME])
	372	nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
	373	else
	374	snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
	375
	376	if (strchr(dev->name, '%')) {
	377	err = dev_alloc_name(dev, dev->name);
	378	if (err < 0)
	379	goto err_alloc_name;
	380	}
	381
	382	err = register_netdevice(dev);
	383	if (err < 0)
	384	goto err_register_dev;
	385
	386	netif_carrier_off(dev);
	387
	388	/*
	389	* tie the deviced together
	390	*/
	391
	392	priv = netdev_priv(dev);
	393	rcu_assign_pointer(priv->peer, peer);
	394
	395	priv = netdev_priv(peer);
	396	rcu_assign_pointer(priv->peer, dev);
	397	return 0;
	398
	399	err_register_dev:
	400	/* nothing to do */
	401	err_alloc_name:
	402	err_configure_peer:
	403	unregister_netdevice(peer);
	404	return err;
	405
	406	err_register_peer:
	407	free_netdev(peer);
	408	return err;
	409	}
	410
	411	static void veth_dellink(struct net_device dev, struct list_head head)
	412	{
	413	struct veth_priv *priv;
	414	struct net_device *peer;
	415
	416	priv = netdev_priv(dev);
	417	peer = rtnl_dereference(priv->peer);
	418
	419	/* Note : dellink() is called from default_device_exit_batch(),
	420	* before a rcu_synchronize() point. The devices are guaranteed
	421	* not being freed before one RCU grace period.
	422	*/
	423	RCU_INIT_POINTER(priv->peer, NULL);
	424	unregister_netdevice_queue(dev, head);
	425
	426	if (peer) {
	427	priv = netdev_priv(peer);
	428	RCU_INIT_POINTER(priv->peer, NULL);
	429	unregister_netdevice_queue(peer, head);
	430	}
	431	}
	432
	433	static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
	434	[VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
	435	};
	436
	437	static struct rtnl_link_ops veth_link_ops = {
	438	.kind = DRV_NAME,
	439	.priv_size = sizeof(struct veth_priv),
	440	.setup = veth_setup,
	441	.validate = veth_validate,
	442	.newlink = veth_newlink,
	443	.dellink = veth_dellink,
	444	.policy = veth_policy,
	445	.maxtype = VETH_INFO_MAX,
	446	};
	447
	448	/*
	449	* init/fini
	450	*/
	451
	452	static __init int veth_init(void)
	453	{
	454	return rtnl_link_register(&veth_link_ops);
	455	}
	456
	457	static __exit void veth_exit(void)
	458	{
	459	rtnl_link_unregister(&veth_link_ops);
	460	}
	461
	462	module_init(veth_init);
	463	module_exit(veth_exit);
	464
	465	MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
	466	MODULE_LICENSE("GPL v2");
	467	MODULE_ALIAS_RTNL_LINK(DRV_NAME);