[deliverable/linux.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;
	}
	/* 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;

	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;
}

/* fake multicast ability */
static void veth_set_multicast_list(struct net_device *dev)
{
}

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)
{
	int i;

	dev->vstats = alloc_percpu(struct pcpu_vstats);
	if (!dev->vstats)
		return -ENOMEM;

	for_each_possible_cpu(i) {
		struct pcpu_vstats *veth_stats;
		veth_stats = per_cpu_ptr(dev->vstats, i);
		u64_stats_init(&veth_stats->syncp);
	}

	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_rx_mode     = veth_set_multicast_list,
	.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_GSO_GRE | NETIF_F_GSO_UDP_TUNNEL |	    \
		       NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT | NETIF_F_UFO	|   \
		       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->vlan_features = dev->features &
			     ~(NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX);
	dev->destructor = veth_dev_free;

	dev->hw_features = VETH_FEATURES;
	dev->hw_enc_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");

	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_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	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
	120	* will cause bad checksum on forwarded packets
	121	*/
	122	if (skb->ip_summed == CHECKSUM_NONE &&
	123	rcv->features & NETIF_F_RXCSUM)
	124	skb->ip_summed = CHECKSUM_UNNECESSARY;
	125
	126	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
	127	struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
	128
	129	u64_stats_update_begin(&stats->syncp);
	130	stats->bytes += length;
	131	stats->packets++;
	132	u64_stats_update_end(&stats->syncp);
	133	} else {
	134	drop:
	135	atomic64_inc(&priv->dropped);
	136	}
	137	rcu_read_unlock();
	138	return NETDEV_TX_OK;
	139	}
	140
	141	/*
	142	* general routines
	143	*/
	144
	145	static u64 veth_stats_one(struct pcpu_vstats result, struct net_device dev)
	146	{
	147	struct veth_priv *priv = netdev_priv(dev);
	148	int cpu;
	149
	150	result->packets = 0;
	151	result->bytes = 0;
	152	for_each_possible_cpu(cpu) {
	153	struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
	154	u64 packets, bytes;
	155	unsigned int start;
	156
	157	do {
	158	start = u64_stats_fetch_begin_bh(&stats->syncp);
	159	packets = stats->packets;
	160	bytes = stats->bytes;
	161	} while (u64_stats_fetch_retry_bh(&stats->syncp, start));
	162	result->packets += packets;
	163	result->bytes += bytes;
	164	}
	165	return atomic64_read(&priv->dropped);
	166	}
	167
	168	static struct rtnl_link_stats64 veth_get_stats64(struct net_device dev,
	169	struct rtnl_link_stats64 *tot)
	170	{
	171	struct veth_priv *priv = netdev_priv(dev);
	172	struct net_device *peer;
	173	struct pcpu_vstats one;
	174
	175	tot->tx_dropped = veth_stats_one(&one, dev);
	176	tot->tx_bytes = one.bytes;
	177	tot->tx_packets = one.packets;
	178
	179	rcu_read_lock();
	180	peer = rcu_dereference(priv->peer);
	181	if (peer) {
	182	tot->rx_dropped = veth_stats_one(&one, peer);
	183	tot->rx_bytes = one.bytes;
	184	tot->rx_packets = one.packets;
	185	}
	186	rcu_read_unlock();
	187
	188	return tot;
	189	}
	190
	191	/* fake multicast ability */
	192	static void veth_set_multicast_list(struct net_device *dev)
	193	{
	194	}
	195
	196	static int veth_open(struct net_device *dev)
	197	{
	198	struct veth_priv *priv = netdev_priv(dev);
	199	struct net_device *peer = rtnl_dereference(priv->peer);
	200
	201	if (!peer)
	202	return -ENOTCONN;
	203
	204	if (peer->flags & IFF_UP) {
	205	netif_carrier_on(dev);
	206	netif_carrier_on(peer);
	207	}
	208	return 0;
	209	}
	210
	211	static int veth_close(struct net_device *dev)
	212	{
	213	struct veth_priv *priv = netdev_priv(dev);
	214	struct net_device *peer = rtnl_dereference(priv->peer);
	215
	216	netif_carrier_off(dev);
	217	if (peer)
	218	netif_carrier_off(peer);
	219
	220	return 0;
	221	}
	222
	223	static int is_valid_veth_mtu(int new_mtu)
	224	{
	225	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
	226	}
	227
	228	static int veth_change_mtu(struct net_device *dev, int new_mtu)
	229	{
	230	if (!is_valid_veth_mtu(new_mtu))
	231	return -EINVAL;
	232	dev->mtu = new_mtu;
	233	return 0;
	234	}
	235
	236	static int veth_dev_init(struct net_device *dev)
	237	{
	238	int i;
	239
	240	dev->vstats = alloc_percpu(struct pcpu_vstats);
	241	if (!dev->vstats)
	242	return -ENOMEM;
	243
	244	for_each_possible_cpu(i) {
	245	struct pcpu_vstats *veth_stats;
	246	veth_stats = per_cpu_ptr(dev->vstats, i);
	247	u64_stats_init(&veth_stats->syncp);
	248	}
	249
	250	return 0;
	251	}
	252
	253	static void veth_dev_free(struct net_device *dev)
	254	{
	255	free_percpu(dev->vstats);
	256	free_netdev(dev);
	257	}
	258
	259	static const struct net_device_ops veth_netdev_ops = {
	260	.ndo_init = veth_dev_init,
	261	.ndo_open = veth_open,
	262	.ndo_stop = veth_close,
	263	.ndo_start_xmit = veth_xmit,
	264	.ndo_change_mtu = veth_change_mtu,
	265	.ndo_get_stats64 = veth_get_stats64,
	266	.ndo_set_rx_mode = veth_set_multicast_list,
	267	.ndo_set_mac_address = eth_mac_addr,
	268	};
	269
	270	#define VETH_FEATURES (NETIF_F_SG \| NETIF_F_FRAGLIST \| NETIF_F_ALL_TSO \| \
	271	NETIF_F_HW_CSUM \| NETIF_F_RXCSUM \| NETIF_F_HIGHDMA \| \
	272	NETIF_F_GSO_GRE \| NETIF_F_GSO_UDP_TUNNEL \| \
	273	NETIF_F_GSO_IPIP \| NETIF_F_GSO_SIT \| NETIF_F_UFO \| \
	274	NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_CTAG_RX \| \
	275	NETIF_F_HW_VLAN_STAG_TX \| NETIF_F_HW_VLAN_STAG_RX )
	276
	277	static void veth_setup(struct net_device *dev)
	278	{
	279	ether_setup(dev);
	280
	281	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	282	dev->priv_flags \|= IFF_LIVE_ADDR_CHANGE;
	283
	284	dev->netdev_ops = &veth_netdev_ops;
	285	dev->ethtool_ops = &veth_ethtool_ops;
	286	dev->features \|= NETIF_F_LLTX;
	287	dev->features \|= VETH_FEATURES;
	288	dev->vlan_features = dev->features &
	289	~(NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_STAG_TX);
	290	dev->destructor = veth_dev_free;
	291
	292	dev->hw_features = VETH_FEATURES;
	293	dev->hw_enc_features = VETH_FEATURES;
	294	}
	295
	296	/*
	297	* netlink interface
	298	*/
	299
	300	static int veth_validate(struct nlattr tb[], struct nlattr data[])
	301	{
	302	if (tb[IFLA_ADDRESS]) {
	303	if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
	304	return -EINVAL;
	305	if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
	306	return -EADDRNOTAVAIL;
	307	}
	308	if (tb[IFLA_MTU]) {
	309	if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
	310	return -EINVAL;
	311	}
	312	return 0;
	313	}
	314
	315	static struct rtnl_link_ops veth_link_ops;
	316
	317	static int veth_newlink(struct net src_net, struct net_device dev,
	318	struct nlattr tb[], struct nlattr data[])
	319	{
	320	int err;
	321	struct net_device *peer;
	322	struct veth_priv *priv;
	323	char ifname[IFNAMSIZ];
	324	struct nlattr peer_tb[IFLA_MAX + 1], *tbp;
	325	struct ifinfomsg *ifmp;
	326	struct net *net;
	327
	328	/*
	329	* create and register peer first
	330	*/
	331	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
	332	struct nlattr *nla_peer;
	333
	334	nla_peer = data[VETH_INFO_PEER];
	335	ifmp = nla_data(nla_peer);
	336	err = nla_parse(peer_tb, IFLA_MAX,
	337	nla_data(nla_peer) + sizeof(struct ifinfomsg),
	338	nla_len(nla_peer) - sizeof(struct ifinfomsg),
	339	ifla_policy);
	340	if (err < 0)
	341	return err;
	342
	343	err = veth_validate(peer_tb, NULL);
	344	if (err < 0)
	345	return err;
	346
	347	tbp = peer_tb;
	348	} else {
	349	ifmp = NULL;
	350	tbp = tb;
	351	}
	352
	353	if (tbp[IFLA_IFNAME])
	354	nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
	355	else
	356	snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
	357
	358	net = rtnl_link_get_net(src_net, tbp);
	359	if (IS_ERR(net))
	360	return PTR_ERR(net);
	361
	362	peer = rtnl_create_link(net, ifname, &veth_link_ops, tbp);
	363	if (IS_ERR(peer)) {
	364	put_net(net);
	365	return PTR_ERR(peer);
	366	}
	367
	368	if (tbp[IFLA_ADDRESS] == NULL)
	369	eth_hw_addr_random(peer);
	370
	371	if (ifmp && (dev->ifindex != 0))
	372	peer->ifindex = ifmp->ifi_index;
	373
	374	err = register_netdevice(peer);
	375	put_net(net);
	376	net = NULL;
	377	if (err < 0)
	378	goto err_register_peer;
	379
	380	netif_carrier_off(peer);
	381
	382	err = rtnl_configure_link(peer, ifmp);
	383	if (err < 0)
	384	goto err_configure_peer;
	385
	386	/*
	387	* register dev last
	388	*
	389	* note, that since we've registered new device the dev's name
	390	* should be re-allocated
	391	*/
	392
	393	if (tb[IFLA_ADDRESS] == NULL)
	394	eth_hw_addr_random(dev);
	395
	396	if (tb[IFLA_IFNAME])
	397	nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
	398	else
	399	snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
	400
	401	err = register_netdevice(dev);
	402	if (err < 0)
	403	goto err_register_dev;
	404
	405	netif_carrier_off(dev);
	406
	407	/*
	408	* tie the deviced together
	409	*/
	410
	411	priv = netdev_priv(dev);
	412	rcu_assign_pointer(priv->peer, peer);
	413
	414	priv = netdev_priv(peer);
	415	rcu_assign_pointer(priv->peer, dev);
	416	return 0;
	417
	418	err_register_dev:
	419	/* nothing to do */
	420	err_configure_peer:
	421	unregister_netdevice(peer);
	422	return err;
	423
	424	err_register_peer:
	425	free_netdev(peer);
	426	return err;
	427	}
	428
	429	static void veth_dellink(struct net_device dev, struct list_head head)
	430	{
	431	struct veth_priv *priv;
	432	struct net_device *peer;
	433
	434	priv = netdev_priv(dev);
	435	peer = rtnl_dereference(priv->peer);
	436
	437	/* Note : dellink() is called from default_device_exit_batch(),
	438	* before a rcu_synchronize() point. The devices are guaranteed
	439	* not being freed before one RCU grace period.
	440	*/
	441	RCU_INIT_POINTER(priv->peer, NULL);
	442	unregister_netdevice_queue(dev, head);
	443
	444	if (peer) {
	445	priv = netdev_priv(peer);
	446	RCU_INIT_POINTER(priv->peer, NULL);
	447	unregister_netdevice_queue(peer, head);
	448	}
	449	}
	450
	451	static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
	452	[VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
	453	};
	454
	455	static struct rtnl_link_ops veth_link_ops = {
	456	.kind = DRV_NAME,
	457	.priv_size = sizeof(struct veth_priv),
	458	.setup = veth_setup,
	459	.validate = veth_validate,
	460	.newlink = veth_newlink,
	461	.dellink = veth_dellink,
	462	.policy = veth_policy,
	463	.maxtype = VETH_INFO_MAX,
	464	};
	465
	466	/*
	467	* init/fini
	468	*/
	469
	470	static __init int veth_init(void)
	471	{
	472	return rtnl_link_register(&veth_link_ops);
	473	}
	474
	475	static __exit void veth_exit(void)
	476	{
	477	rtnl_link_unregister(&veth_link_ops);
	478	}
	479
	480	module_init(veth_init);
	481	module_exit(veth_exit);
	482
	483	MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
	484	MODULE_LICENSE("GPL v2");
	485	MODULE_ALIAS_RTNL_LINK(DRV_NAME);