drivers/net/veth.c - kernel/msm-5.4 - Gitiles

 /*
  *  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 veth_net_stats {
 	u64			rx_packets;
 	u64			rx_bytes;
 	u64			tx_packets;
 	u64			tx_bytes;
 	u64			rx_dropped;
 	struct u64_stats_sync	syncp;
 };

 struct veth_priv {
 	struct net_device *peer;
 	struct veth_net_stats __percpu *stats;
 };

 /*
  * 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));
 	strlcpy(info->fw_version, "N/A", sizeof(info->fw_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;

 	priv = netdev_priv(dev);
 	data[0] = priv->peer->ifindex;
 }

 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,
 };

 /*
  * xmit
  */

 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_device *rcv = NULL;
 	struct veth_priv *priv, *rcv_priv;
 	struct veth_net_stats *stats, *rcv_stats;
 	int length;

 	priv = netdev_priv(dev);
 	rcv = priv->peer;
 	rcv_priv = netdev_priv(rcv);

 	stats = this_cpu_ptr(priv->stats);
 	rcv_stats = this_cpu_ptr(rcv_priv->stats);

 	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
 	   will cause bad checksum on forwarded packets */
 	if (skb->ip_summed == CHECKSUM_NONE &&
 	    rcv->features & NETIF_F_RXCSUM)
 		skb->ip_summed = CHECKSUM_UNNECESSARY;

 	length = skb->len;
 	if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
 		goto rx_drop;

 	u64_stats_update_begin(&stats->syncp);
 	stats->tx_bytes += length;
 	stats->tx_packets++;
 	u64_stats_update_end(&stats->syncp);

 	u64_stats_update_begin(&rcv_stats->syncp);
 	rcv_stats->rx_bytes += length;
 	rcv_stats->rx_packets++;
 	u64_stats_update_end(&rcv_stats->syncp);

 	return NETDEV_TX_OK;

 rx_drop:
 	u64_stats_update_begin(&rcv_stats->syncp);
 	rcv_stats->rx_dropped++;
 	u64_stats_update_end(&rcv_stats->syncp);
 	return NETDEV_TX_OK;
 }

 /*
  * general routines
  */

 static struct rtnl_link_stats64 *veth_get_stats64(struct net_device *dev,
 						  struct rtnl_link_stats64 *tot)
 {
 	struct veth_priv *priv = netdev_priv(dev);
 	int cpu;

 	for_each_possible_cpu(cpu) {
 		struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
 		u64 rx_packets, rx_bytes, rx_dropped;
 		u64 tx_packets, tx_bytes;
 		unsigned int start;

 		do {
 			start = u64_stats_fetch_begin_bh(&stats->syncp);
 			rx_packets = stats->rx_packets;
 			tx_packets = stats->tx_packets;
 			rx_bytes = stats->rx_bytes;
 			tx_bytes = stats->tx_bytes;
 			rx_dropped = stats->rx_dropped;
 		} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
 		tot->rx_packets += rx_packets;
 		tot->tx_packets += tx_packets;
 		tot->rx_bytes   += rx_bytes;
 		tot->tx_bytes   += tx_bytes;
 		tot->rx_dropped += rx_dropped;
 	}

 	return tot;
 }

 static int veth_open(struct net_device *dev)
 {
 	struct veth_priv *priv;

 	priv = netdev_priv(dev);
 	if (priv->peer == NULL)
 		return -ENOTCONN;

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

 static int veth_close(struct net_device *dev)
 {
 	struct veth_priv *priv = netdev_priv(dev);

 	netif_carrier_off(dev);
 	netif_carrier_off(priv->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)
 {
 	struct veth_net_stats __percpu *stats;
 	struct veth_priv *priv;

 	stats = alloc_percpu(struct veth_net_stats);
 	if (stats == NULL)
 		return -ENOMEM;

 	priv = netdev_priv(dev);
 	priv->stats = stats;
 	return 0;
 }

 static void veth_dev_free(struct net_device *dev)
 {
 	struct veth_priv *priv;

 	priv = netdev_priv(dev);
 	free_percpu(priv->stats);
 	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,
 };

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

 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;

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

 	dev->hw_features = NETIF_F_HW_CSUM | NETIF_F_SG | NETIF_F_RXCSUM;
 }

 /*
  * 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(src_net, net, ifname, &veth_link_ops, tbp);
 	if (IS_ERR(peer)) {
 		put_net(net);
 		return PTR_ERR(peer);
 	}

 	if (tbp[IFLA_ADDRESS] == NULL)
 		random_ether_addr(peer->dev_addr);

 	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)
 		random_ether_addr(dev->dev_addr);

 	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);
 	priv->peer = peer;

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

 	unregister_netdevice_queue(dev, head);
 	unregister_netdevice_queue(peer, head);
 }

 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];

 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);
	/*
	* 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 veth_net_stats {
	u64 rx_packets;
	u64 rx_bytes;
	u64 tx_packets;
	u64 tx_bytes;
	u64 rx_dropped;
	struct u64_stats_sync syncp;
	};

	struct veth_priv {
	struct net_device *peer;
	struct veth_net_stats __percpu *stats;
	};

	/*
	* 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));
	strlcpy(info->fw_version, "N/A", sizeof(info->fw_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;

	priv = netdev_priv(dev);
	data[0] = priv->peer->ifindex;
	}

	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,
	};

	/*
	* xmit
	*/

	static netdev_tx_t veth_xmit(struct sk_buff skb, struct net_device dev)
	{
	struct net_device *rcv = NULL;
	struct veth_priv priv, rcv_priv;
	struct veth_net_stats stats, rcv_stats;
	int length;

	priv = netdev_priv(dev);
	rcv = priv->peer;
	rcv_priv = netdev_priv(rcv);

	stats = this_cpu_ptr(priv->stats);
	rcv_stats = this_cpu_ptr(rcv_priv->stats);

	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
	will cause bad checksum on forwarded packets */
	if (skb->ip_summed == CHECKSUM_NONE &&
	rcv->features & NETIF_F_RXCSUM)
	skb->ip_summed = CHECKSUM_UNNECESSARY;

	length = skb->len;
	if (dev_forward_skb(rcv, skb) != NET_RX_SUCCESS)
	goto rx_drop;

	u64_stats_update_begin(&stats->syncp);
	stats->tx_bytes += length;
	stats->tx_packets++;
	u64_stats_update_end(&stats->syncp);

	u64_stats_update_begin(&rcv_stats->syncp);
	rcv_stats->rx_bytes += length;
	rcv_stats->rx_packets++;
	u64_stats_update_end(&rcv_stats->syncp);

	return NETDEV_TX_OK;

	rx_drop:
	u64_stats_update_begin(&rcv_stats->syncp);
	rcv_stats->rx_dropped++;
	u64_stats_update_end(&rcv_stats->syncp);
	return NETDEV_TX_OK;
	}

	/*
	* general routines
	*/

	static struct rtnl_link_stats64 veth_get_stats64(struct net_device dev,
	struct rtnl_link_stats64 *tot)
	{
	struct veth_priv *priv = netdev_priv(dev);
	int cpu;

	for_each_possible_cpu(cpu) {
	struct veth_net_stats *stats = per_cpu_ptr(priv->stats, cpu);
	u64 rx_packets, rx_bytes, rx_dropped;
	u64 tx_packets, tx_bytes;
	unsigned int start;

	do {
	start = u64_stats_fetch_begin_bh(&stats->syncp);
	rx_packets = stats->rx_packets;
	tx_packets = stats->tx_packets;
	rx_bytes = stats->rx_bytes;
	tx_bytes = stats->tx_bytes;
	rx_dropped = stats->rx_dropped;
	} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
	tot->rx_packets += rx_packets;
	tot->tx_packets += tx_packets;
	tot->rx_bytes += rx_bytes;
	tot->tx_bytes += tx_bytes;
	tot->rx_dropped += rx_dropped;
	}

	return tot;
	}

	static int veth_open(struct net_device *dev)
	{
	struct veth_priv *priv;

	priv = netdev_priv(dev);
	if (priv->peer == NULL)
	return -ENOTCONN;

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

	static int veth_close(struct net_device *dev)
	{
	struct veth_priv *priv = netdev_priv(dev);

	netif_carrier_off(dev);
	netif_carrier_off(priv->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)
	{
	struct veth_net_stats __percpu *stats;
	struct veth_priv *priv;

	stats = alloc_percpu(struct veth_net_stats);
	if (stats == NULL)
	return -ENOMEM;

	priv = netdev_priv(dev);
	priv->stats = stats;
	return 0;
	}

	static void veth_dev_free(struct net_device *dev)
	{
	struct veth_priv *priv;

	priv = netdev_priv(dev);
	free_percpu(priv->stats);
	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,
	};

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

	dev->priv_flags &= ~IFF_TX_SKB_SHARING;

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

	dev->hw_features = NETIF_F_HW_CSUM \| NETIF_F_SG \| NETIF_F_RXCSUM;
	}

	/*
	* 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(src_net, net, ifname, &veth_link_ops, tbp);
	if (IS_ERR(peer)) {
	put_net(net);
	return PTR_ERR(peer);
	}

	if (tbp[IFLA_ADDRESS] == NULL)
	random_ether_addr(peer->dev_addr);

	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)
	random_ether_addr(dev->dev_addr);

	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);
	priv->peer = peer;

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

	unregister_netdevice_queue(dev, head);
	unregister_netdevice_queue(peer, head);
	}

	static const struct nla_policy veth_policy[VETH_INFO_MAX + 1];

	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);