[linux-2.6-block.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/rtnetlink.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_irq(&stats->syncp);
			packets = stats->packets;
			bytes = stats->bytes;
		} while (u64_stats_fetch_retry_irq(&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)
{
	dev->vstats = netdev_alloc_pcpu_stats(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);
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void veth_poll_controller(struct net_device *dev)
{
	/* veth only receives frames when its peer sends one
	 * Since it's a synchronous operation, we are guaranteed
	 * never to have pending data when we poll for it so
	 * there is nothing to do here.
	 *
	 * We need this though so netpoll recognizes us as an interface that
	 * supports polling, which enables bridge devices in virt setups to
	 * still use netconsole
	 */
}
#endif	/* CONFIG_NET_POLL_CONTROLLER */

static int veth_get_iflink(const struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer;
	int iflink;

	rcu_read_lock();
	peer = rcu_dereference(priv->peer);
	iflink = peer ? peer->ifindex : 0;
	rcu_read_unlock();

	return iflink;
}

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,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller	= veth_poll_controller,
#endif
	.ndo_get_iflink		= veth_get_iflink,
	.ndo_features_check	= passthru_features_check,
};

#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->priv_flags |= IFF_NO_QUEUE;

	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 |
			       NETIF_F_HW_VLAN_CTAG_RX |
			       NETIF_F_HW_VLAN_STAG_RX);
	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;
	unsigned char name_assign_type;
	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 = rtnl_nla_parse_ifla(peer_tb,
					  nla_data(nla_peer) + sizeof(struct ifinfomsg),
					  nla_len(nla_peer) - sizeof(struct ifinfomsg));
		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);
		name_assign_type = NET_NAME_USER;
	} else {
		snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
		name_assign_type = NET_NAME_ENUM;
	}

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

	peer = rtnl_create_link(net, ifname, name_assign_type,
				&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 net *veth_get_link_net(const struct net_device *dev)
{
	struct veth_priv *priv = netdev_priv(dev);
	struct net_device *peer = rtnl_dereference(priv->peer);

	return peer ? dev_net(peer) : dev_net(dev);
}

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,
	.get_link_net	= veth_get_link_net,
};

/*
 * 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/rtnetlink.h>
	18	#include <net/dst.h>
	19	#include <net/xfrm.h>
	20	#include <linux/veth.h>
	21	#include <linux/module.h>
	22
	23	#define DRV_NAME "veth"
	24	#define DRV_VERSION "1.0"
	25
	26	#define MIN_MTU 68 /* Min L3 MTU */
	27	#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */
	28
	29	struct pcpu_vstats {
	30	u64 packets;
	31	u64 bytes;
	32	struct u64_stats_sync syncp;
	33	};
	34
	35	struct veth_priv {
	36	struct net_device __rcu *peer;
	37	atomic64_t dropped;
	38	};
	39
	40	/*
	41	* ethtool interface
	42	*/
	43
	44	static struct {
	45	const char string[ETH_GSTRING_LEN];
	46	} ethtool_stats_keys[] = {
	47	{ "peer_ifindex" },
	48	};
	49
	50	static int veth_get_settings(struct net_device dev, struct ethtool_cmd cmd)
	51	{
	52	cmd->supported = 0;
	53	cmd->advertising = 0;
	54	ethtool_cmd_speed_set(cmd, SPEED_10000);
	55	cmd->duplex = DUPLEX_FULL;
	56	cmd->port = PORT_TP;
	57	cmd->phy_address = 0;
	58	cmd->transceiver = XCVR_INTERNAL;
	59	cmd->autoneg = AUTONEG_DISABLE;
	60	cmd->maxtxpkt = 0;
	61	cmd->maxrxpkt = 0;
	62	return 0;
	63	}
	64
	65	static void veth_get_drvinfo(struct net_device dev, struct ethtool_drvinfo info)
	66	{
	67	strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
	68	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
	69	}
	70
	71	static void veth_get_strings(struct net_device dev, u32 stringset, u8 buf)
	72	{
	73	switch(stringset) {
	74	case ETH_SS_STATS:
	75	memcpy(buf, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
	76	break;
	77	}
	78	}
	79
	80	static int veth_get_sset_count(struct net_device *dev, int sset)
	81	{
	82	switch (sset) {
	83	case ETH_SS_STATS:
	84	return ARRAY_SIZE(ethtool_stats_keys);
	85	default:
	86	return -EOPNOTSUPP;
	87	}
	88	}
	89
	90	static void veth_get_ethtool_stats(struct net_device *dev,
	91	struct ethtool_stats stats, u64 data)
	92	{
	93	struct veth_priv *priv = netdev_priv(dev);
	94	struct net_device *peer = rtnl_dereference(priv->peer);
	95
	96	data[0] = peer ? peer->ifindex : 0;
	97	}
	98
	99	static const struct ethtool_ops veth_ethtool_ops = {
	100	.get_settings = veth_get_settings,
	101	.get_drvinfo = veth_get_drvinfo,
	102	.get_link = ethtool_op_get_link,
	103	.get_strings = veth_get_strings,
	104	.get_sset_count = veth_get_sset_count,
	105	.get_ethtool_stats = veth_get_ethtool_stats,
	106	};
	107
	108	static netdev_tx_t veth_xmit(struct sk_buff skb, struct net_device dev)
	109	{
	110	struct veth_priv *priv = netdev_priv(dev);
	111	struct net_device *rcv;
	112	int length = skb->len;
	113
	114	rcu_read_lock();
	115	rcv = rcu_dereference(priv->peer);
	116	if (unlikely(!rcv)) {
	117	kfree_skb(skb);
	118	goto drop;
	119	}
	120
	121	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
	122	struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
	123
	124	u64_stats_update_begin(&stats->syncp);
	125	stats->bytes += length;
	126	stats->packets++;
	127	u64_stats_update_end(&stats->syncp);
	128	} else {
	129	drop:
	130	atomic64_inc(&priv->dropped);
	131	}
	132	rcu_read_unlock();
	133	return NETDEV_TX_OK;
	134	}
	135
	136	/*
	137	* general routines
	138	*/
	139
	140	static u64 veth_stats_one(struct pcpu_vstats result, struct net_device dev)
	141	{
	142	struct veth_priv *priv = netdev_priv(dev);
	143	int cpu;
	144
	145	result->packets = 0;
	146	result->bytes = 0;
	147	for_each_possible_cpu(cpu) {
	148	struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
	149	u64 packets, bytes;
	150	unsigned int start;
	151
	152	do {
	153	start = u64_stats_fetch_begin_irq(&stats->syncp);
	154	packets = stats->packets;
	155	bytes = stats->bytes;
	156	} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
	157	result->packets += packets;
	158	result->bytes += bytes;
	159	}
	160	return atomic64_read(&priv->dropped);
	161	}
	162
	163	static struct rtnl_link_stats64 veth_get_stats64(struct net_device dev,
	164	struct rtnl_link_stats64 *tot)
	165	{
	166	struct veth_priv *priv = netdev_priv(dev);
	167	struct net_device *peer;
	168	struct pcpu_vstats one;
	169
	170	tot->tx_dropped = veth_stats_one(&one, dev);
	171	tot->tx_bytes = one.bytes;
	172	tot->tx_packets = one.packets;
	173
	174	rcu_read_lock();
	175	peer = rcu_dereference(priv->peer);
	176	if (peer) {
	177	tot->rx_dropped = veth_stats_one(&one, peer);
	178	tot->rx_bytes = one.bytes;
	179	tot->rx_packets = one.packets;
	180	}
	181	rcu_read_unlock();
	182
	183	return tot;
	184	}
	185
	186	/* fake multicast ability */
	187	static void veth_set_multicast_list(struct net_device *dev)
	188	{
	189	}
	190
	191	static int veth_open(struct net_device *dev)
	192	{
	193	struct veth_priv *priv = netdev_priv(dev);
	194	struct net_device *peer = rtnl_dereference(priv->peer);
	195
	196	if (!peer)
	197	return -ENOTCONN;
	198
	199	if (peer->flags & IFF_UP) {
	200	netif_carrier_on(dev);
	201	netif_carrier_on(peer);
	202	}
	203	return 0;
	204	}
	205
	206	static int veth_close(struct net_device *dev)
	207	{
	208	struct veth_priv *priv = netdev_priv(dev);
	209	struct net_device *peer = rtnl_dereference(priv->peer);
	210
	211	netif_carrier_off(dev);
	212	if (peer)
	213	netif_carrier_off(peer);
	214
	215	return 0;
	216	}
	217
	218	static int is_valid_veth_mtu(int new_mtu)
	219	{
	220	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
	221	}
	222
	223	static int veth_change_mtu(struct net_device *dev, int new_mtu)
	224	{
	225	if (!is_valid_veth_mtu(new_mtu))
	226	return -EINVAL;
	227	dev->mtu = new_mtu;
	228	return 0;
	229	}
	230
	231	static int veth_dev_init(struct net_device *dev)
	232	{
	233	dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
	234	if (!dev->vstats)
	235	return -ENOMEM;
	236	return 0;
	237	}
	238
	239	static void veth_dev_free(struct net_device *dev)
	240	{
	241	free_percpu(dev->vstats);
	242	free_netdev(dev);
	243	}
	244
	245	#ifdef CONFIG_NET_POLL_CONTROLLER
	246	static void veth_poll_controller(struct net_device *dev)
	247	{
	248	/* veth only receives frames when its peer sends one
	249	* Since it's a synchronous operation, we are guaranteed
	250	* never to have pending data when we poll for it so
	251	* there is nothing to do here.
	252	*
	253	* We need this though so netpoll recognizes us as an interface that
	254	* supports polling, which enables bridge devices in virt setups to
	255	* still use netconsole
	256	*/
	257	}
	258	#endif /* CONFIG_NET_POLL_CONTROLLER */
	259
	260	static int veth_get_iflink(const struct net_device *dev)
	261	{
	262	struct veth_priv *priv = netdev_priv(dev);
	263	struct net_device *peer;
	264	int iflink;
	265
	266	rcu_read_lock();
	267	peer = rcu_dereference(priv->peer);
	268	iflink = peer ? peer->ifindex : 0;
	269	rcu_read_unlock();
	270
	271	return iflink;
	272	}
	273
	274	static const struct net_device_ops veth_netdev_ops = {
	275	.ndo_init = veth_dev_init,
	276	.ndo_open = veth_open,
	277	.ndo_stop = veth_close,
	278	.ndo_start_xmit = veth_xmit,
	279	.ndo_change_mtu = veth_change_mtu,
	280	.ndo_get_stats64 = veth_get_stats64,
	281	.ndo_set_rx_mode = veth_set_multicast_list,
	282	.ndo_set_mac_address = eth_mac_addr,
	283	#ifdef CONFIG_NET_POLL_CONTROLLER
	284	.ndo_poll_controller = veth_poll_controller,
	285	#endif
	286	.ndo_get_iflink = veth_get_iflink,
	287	.ndo_features_check = passthru_features_check,
	288	};
	289
	290	#define VETH_FEATURES (NETIF_F_SG \| NETIF_F_FRAGLIST \| NETIF_F_ALL_TSO \| \
	291	NETIF_F_HW_CSUM \| NETIF_F_RXCSUM \| NETIF_F_HIGHDMA \| \
	292	NETIF_F_GSO_GRE \| NETIF_F_GSO_UDP_TUNNEL \| \
	293	NETIF_F_GSO_IPIP \| NETIF_F_GSO_SIT \| NETIF_F_UFO \| \
	294	NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_CTAG_RX \| \
	295	NETIF_F_HW_VLAN_STAG_TX \| NETIF_F_HW_VLAN_STAG_RX )
	296
	297	static void veth_setup(struct net_device *dev)
	298	{
	299	ether_setup(dev);
	300
	301	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	302	dev->priv_flags \|= IFF_LIVE_ADDR_CHANGE;
	303	dev->priv_flags \|= IFF_NO_QUEUE;
	304
	305	dev->netdev_ops = &veth_netdev_ops;
	306	dev->ethtool_ops = &veth_ethtool_ops;
	307	dev->features \|= NETIF_F_LLTX;
	308	dev->features \|= VETH_FEATURES;
	309	dev->vlan_features = dev->features &
	310	~(NETIF_F_HW_VLAN_CTAG_TX \|
	311	NETIF_F_HW_VLAN_STAG_TX \|
	312	NETIF_F_HW_VLAN_CTAG_RX \|
	313	NETIF_F_HW_VLAN_STAG_RX);
	314	dev->destructor = veth_dev_free;
	315
	316	dev->hw_features = VETH_FEATURES;
	317	dev->hw_enc_features = VETH_FEATURES;
	318	}
	319
	320	/*
	321	* netlink interface
	322	*/
	323
	324	static int veth_validate(struct nlattr tb[], struct nlattr data[])
	325	{
	326	if (tb[IFLA_ADDRESS]) {
	327	if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
	328	return -EINVAL;
	329	if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
	330	return -EADDRNOTAVAIL;
	331	}
	332	if (tb[IFLA_MTU]) {
	333	if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
	334	return -EINVAL;
	335	}
	336	return 0;
	337	}
	338
	339	static struct rtnl_link_ops veth_link_ops;
	340
	341	static int veth_newlink(struct net src_net, struct net_device dev,
	342	struct nlattr tb[], struct nlattr data[])
	343	{
	344	int err;
	345	struct net_device *peer;
	346	struct veth_priv *priv;
	347	char ifname[IFNAMSIZ];
	348	struct nlattr peer_tb[IFLA_MAX + 1], *tbp;
	349	unsigned char name_assign_type;
	350	struct ifinfomsg *ifmp;
	351	struct net *net;
	352
	353	/*
	354	* create and register peer first
	355	*/
	356	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
	357	struct nlattr *nla_peer;
	358
	359	nla_peer = data[VETH_INFO_PEER];
	360	ifmp = nla_data(nla_peer);
	361	err = rtnl_nla_parse_ifla(peer_tb,
	362	nla_data(nla_peer) + sizeof(struct ifinfomsg),
	363	nla_len(nla_peer) - sizeof(struct ifinfomsg));
	364	if (err < 0)
	365	return err;
	366
	367	err = veth_validate(peer_tb, NULL);
	368	if (err < 0)
	369	return err;
	370
	371	tbp = peer_tb;
	372	} else {
	373	ifmp = NULL;
	374	tbp = tb;
	375	}
	376
	377	if (tbp[IFLA_IFNAME]) {
	378	nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
	379	name_assign_type = NET_NAME_USER;
	380	} else {
	381	snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
	382	name_assign_type = NET_NAME_ENUM;
	383	}
	384
	385	net = rtnl_link_get_net(src_net, tbp);
	386	if (IS_ERR(net))
	387	return PTR_ERR(net);
	388
	389	peer = rtnl_create_link(net, ifname, name_assign_type,
	390	&veth_link_ops, tbp);
	391	if (IS_ERR(peer)) {
	392	put_net(net);
	393	return PTR_ERR(peer);
	394	}
	395
	396	if (tbp[IFLA_ADDRESS] == NULL)
	397	eth_hw_addr_random(peer);
	398
	399	if (ifmp && (dev->ifindex != 0))
	400	peer->ifindex = ifmp->ifi_index;
	401
	402	err = register_netdevice(peer);
	403	put_net(net);
	404	net = NULL;
	405	if (err < 0)
	406	goto err_register_peer;
	407
	408	netif_carrier_off(peer);
	409
	410	err = rtnl_configure_link(peer, ifmp);
	411	if (err < 0)
	412	goto err_configure_peer;
	413
	414	/*
	415	* register dev last
	416	*
	417	* note, that since we've registered new device the dev's name
	418	* should be re-allocated
	419	*/
	420
	421	if (tb[IFLA_ADDRESS] == NULL)
	422	eth_hw_addr_random(dev);
	423
	424	if (tb[IFLA_IFNAME])
	425	nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
	426	else
	427	snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
	428
	429	err = register_netdevice(dev);
	430	if (err < 0)
	431	goto err_register_dev;
	432
	433	netif_carrier_off(dev);
	434
	435	/*
	436	* tie the deviced together
	437	*/
	438
	439	priv = netdev_priv(dev);
	440	rcu_assign_pointer(priv->peer, peer);
	441
	442	priv = netdev_priv(peer);
	443	rcu_assign_pointer(priv->peer, dev);
	444	return 0;
	445
	446	err_register_dev:
	447	/* nothing to do */
	448	err_configure_peer:
	449	unregister_netdevice(peer);
	450	return err;
	451
	452	err_register_peer:
	453	free_netdev(peer);
	454	return err;
	455	}
	456
	457	static void veth_dellink(struct net_device dev, struct list_head head)
	458	{
	459	struct veth_priv *priv;
	460	struct net_device *peer;
	461
	462	priv = netdev_priv(dev);
	463	peer = rtnl_dereference(priv->peer);
	464
	465	/* Note : dellink() is called from default_device_exit_batch(),
	466	* before a rcu_synchronize() point. The devices are guaranteed
	467	* not being freed before one RCU grace period.
	468	*/
	469	RCU_INIT_POINTER(priv->peer, NULL);
	470	unregister_netdevice_queue(dev, head);
	471
	472	if (peer) {
	473	priv = netdev_priv(peer);
	474	RCU_INIT_POINTER(priv->peer, NULL);
	475	unregister_netdevice_queue(peer, head);
	476	}
	477	}
	478
	479	static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
	480	[VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
	481	};
	482
	483	static struct net veth_get_link_net(const struct net_device dev)
	484	{
	485	struct veth_priv *priv = netdev_priv(dev);
	486	struct net_device *peer = rtnl_dereference(priv->peer);
	487
	488	return peer ? dev_net(peer) : dev_net(dev);
	489	}
	490
	491	static struct rtnl_link_ops veth_link_ops = {
	492	.kind = DRV_NAME,
	493	.priv_size = sizeof(struct veth_priv),
	494	.setup = veth_setup,
	495	.validate = veth_validate,
	496	.newlink = veth_newlink,
	497	.dellink = veth_dellink,
	498	.policy = veth_policy,
	499	.maxtype = VETH_INFO_MAX,
	500	.get_link_net = veth_get_link_net,
	501	};
	502
	503	/*
	504	* init/fini
	505	*/
	506
	507	static __init int veth_init(void)
	508	{
	509	return rtnl_link_register(&veth_link_ops);
	510	}
	511
	512	static __exit void veth_exit(void)
	513	{
	514	rtnl_link_unregister(&veth_link_ops);
	515	}
	516
	517	module_init(veth_init);
	518	module_exit(veth_exit);
	519
	520	MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
	521	MODULE_LICENSE("GPL v2");
	522	MODULE_ALIAS_RTNL_LINK(DRV_NAME);