[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/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;
	}
	/* 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_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,
};

#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 |
			       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	/* don't change ip_summed == CHECKSUM_PARTIAL, as that
	121	* will cause bad checksum on forwarded packets
	122	*/
	123	if (skb->ip_summed == CHECKSUM_NONE &&
	124	rcv->features & NETIF_F_RXCSUM)
	125	skb->ip_summed = CHECKSUM_UNNECESSARY;
	126
	127	if (likely(dev_forward_skb(rcv, skb) == NET_RX_SUCCESS)) {
	128	struct pcpu_vstats *stats = this_cpu_ptr(dev->vstats);
	129
	130	u64_stats_update_begin(&stats->syncp);
	131	stats->bytes += length;
	132	stats->packets++;
	133	u64_stats_update_end(&stats->syncp);
	134	} else {
	135	drop:
	136	atomic64_inc(&priv->dropped);
	137	}
	138	rcu_read_unlock();
	139	return NETDEV_TX_OK;
	140	}
	141
	142	/*
	143	* general routines
	144	*/
	145
	146	static u64 veth_stats_one(struct pcpu_vstats result, struct net_device dev)
	147	{
	148	struct veth_priv *priv = netdev_priv(dev);
	149	int cpu;
	150
	151	result->packets = 0;
	152	result->bytes = 0;
	153	for_each_possible_cpu(cpu) {
	154	struct pcpu_vstats *stats = per_cpu_ptr(dev->vstats, cpu);
	155	u64 packets, bytes;
	156	unsigned int start;
	157
	158	do {
	159	start = u64_stats_fetch_begin_irq(&stats->syncp);
	160	packets = stats->packets;
	161	bytes = stats->bytes;
	162	} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
	163	result->packets += packets;
	164	result->bytes += bytes;
	165	}
	166	return atomic64_read(&priv->dropped);
	167	}
	168
	169	static struct rtnl_link_stats64 veth_get_stats64(struct net_device dev,
	170	struct rtnl_link_stats64 *tot)
	171	{
	172	struct veth_priv *priv = netdev_priv(dev);
	173	struct net_device *peer;
	174	struct pcpu_vstats one;
	175
	176	tot->tx_dropped = veth_stats_one(&one, dev);
	177	tot->tx_bytes = one.bytes;
	178	tot->tx_packets = one.packets;
	179
	180	rcu_read_lock();
	181	peer = rcu_dereference(priv->peer);
	182	if (peer) {
	183	tot->rx_dropped = veth_stats_one(&one, peer);
	184	tot->rx_bytes = one.bytes;
	185	tot->rx_packets = one.packets;
	186	}
	187	rcu_read_unlock();
	188
	189	return tot;
	190	}
	191
	192	/* fake multicast ability */
	193	static void veth_set_multicast_list(struct net_device *dev)
	194	{
	195	}
	196
	197	static int veth_open(struct net_device *dev)
	198	{
	199	struct veth_priv *priv = netdev_priv(dev);
	200	struct net_device *peer = rtnl_dereference(priv->peer);
	201
	202	if (!peer)
	203	return -ENOTCONN;
	204
	205	if (peer->flags & IFF_UP) {
	206	netif_carrier_on(dev);
	207	netif_carrier_on(peer);
	208	}
	209	return 0;
	210	}
	211
	212	static int veth_close(struct net_device *dev)
	213	{
	214	struct veth_priv *priv = netdev_priv(dev);
	215	struct net_device *peer = rtnl_dereference(priv->peer);
	216
	217	netif_carrier_off(dev);
	218	if (peer)
	219	netif_carrier_off(peer);
	220
	221	return 0;
	222	}
	223
	224	static int is_valid_veth_mtu(int new_mtu)
	225	{
	226	return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
	227	}
	228
	229	static int veth_change_mtu(struct net_device *dev, int new_mtu)
	230	{
	231	if (!is_valid_veth_mtu(new_mtu))
	232	return -EINVAL;
	233	dev->mtu = new_mtu;
	234	return 0;
	235	}
	236
	237	static int veth_dev_init(struct net_device *dev)
	238	{
	239	dev->vstats = netdev_alloc_pcpu_stats(struct pcpu_vstats);
	240	if (!dev->vstats)
	241	return -ENOMEM;
	242	return 0;
	243	}
	244
	245	static void veth_dev_free(struct net_device *dev)
	246	{
	247	free_percpu(dev->vstats);
	248	free_netdev(dev);
	249	}
	250
	251	#ifdef CONFIG_NET_POLL_CONTROLLER
	252	static void veth_poll_controller(struct net_device *dev)
	253	{
	254	/* veth only receives frames when its peer sends one
	255	* Since it's a synchronous operation, we are guaranteed
	256	* never to have pending data when we poll for it so
	257	* there is nothing to do here.
	258	*
	259	* We need this though so netpoll recognizes us as an interface that
	260	* supports polling, which enables bridge devices in virt setups to
	261	* still use netconsole
	262	*/
	263	}
	264	#endif /* CONFIG_NET_POLL_CONTROLLER */
	265
	266	static int veth_get_iflink(const struct net_device *dev)
	267	{
	268	struct veth_priv *priv = netdev_priv(dev);
	269	struct net_device *peer;
	270	int iflink;
	271
	272	rcu_read_lock();
	273	peer = rcu_dereference(priv->peer);
	274	iflink = peer ? peer->ifindex : 0;
	275	rcu_read_unlock();
	276
	277	return iflink;
	278	}
	279
	280	static const struct net_device_ops veth_netdev_ops = {
	281	.ndo_init = veth_dev_init,
	282	.ndo_open = veth_open,
	283	.ndo_stop = veth_close,
	284	.ndo_start_xmit = veth_xmit,
	285	.ndo_change_mtu = veth_change_mtu,
	286	.ndo_get_stats64 = veth_get_stats64,
	287	.ndo_set_rx_mode = veth_set_multicast_list,
	288	.ndo_set_mac_address = eth_mac_addr,
	289	#ifdef CONFIG_NET_POLL_CONTROLLER
	290	.ndo_poll_controller = veth_poll_controller,
	291	#endif
	292	.ndo_get_iflink = veth_get_iflink,
	293	};
	294
	295	#define VETH_FEATURES (NETIF_F_SG \| NETIF_F_FRAGLIST \| NETIF_F_ALL_TSO \| \
	296	NETIF_F_HW_CSUM \| NETIF_F_RXCSUM \| NETIF_F_HIGHDMA \| \
	297	NETIF_F_GSO_GRE \| NETIF_F_GSO_UDP_TUNNEL \| \
	298	NETIF_F_GSO_IPIP \| NETIF_F_GSO_SIT \| NETIF_F_UFO \| \
	299	NETIF_F_HW_VLAN_CTAG_TX \| NETIF_F_HW_VLAN_CTAG_RX \| \
	300	NETIF_F_HW_VLAN_STAG_TX \| NETIF_F_HW_VLAN_STAG_RX )
	301
	302	static void veth_setup(struct net_device *dev)
	303	{
	304	ether_setup(dev);
	305
	306	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
	307	dev->priv_flags \|= IFF_LIVE_ADDR_CHANGE;
	308
	309	dev->netdev_ops = &veth_netdev_ops;
	310	dev->ethtool_ops = &veth_ethtool_ops;
	311	dev->features \|= NETIF_F_LLTX;
	312	dev->features \|= VETH_FEATURES;
	313	dev->vlan_features = dev->features &
	314	~(NETIF_F_HW_VLAN_CTAG_TX \|
	315	NETIF_F_HW_VLAN_STAG_TX \|
	316	NETIF_F_HW_VLAN_CTAG_RX \|
	317	NETIF_F_HW_VLAN_STAG_RX);
	318	dev->destructor = veth_dev_free;
	319
	320	dev->hw_features = VETH_FEATURES;
	321	dev->hw_enc_features = VETH_FEATURES;
	322	}
	323
	324	/*
	325	* netlink interface
	326	*/
	327
	328	static int veth_validate(struct nlattr tb[], struct nlattr data[])
	329	{
	330	if (tb[IFLA_ADDRESS]) {
	331	if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
	332	return -EINVAL;
	333	if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
	334	return -EADDRNOTAVAIL;
	335	}
	336	if (tb[IFLA_MTU]) {
	337	if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
	338	return -EINVAL;
	339	}
	340	return 0;
	341	}
	342
	343	static struct rtnl_link_ops veth_link_ops;
	344
	345	static int veth_newlink(struct net src_net, struct net_device dev,
	346	struct nlattr tb[], struct nlattr data[])
	347	{
	348	int err;
	349	struct net_device *peer;
	350	struct veth_priv *priv;
	351	char ifname[IFNAMSIZ];
	352	struct nlattr peer_tb[IFLA_MAX + 1], *tbp;
	353	unsigned char name_assign_type;
	354	struct ifinfomsg *ifmp;
	355	struct net *net;
	356
	357	/*
	358	* create and register peer first
	359	*/
	360	if (data != NULL && data[VETH_INFO_PEER] != NULL) {
	361	struct nlattr *nla_peer;
	362
	363	nla_peer = data[VETH_INFO_PEER];
	364	ifmp = nla_data(nla_peer);
	365	err = rtnl_nla_parse_ifla(peer_tb,
	366	nla_data(nla_peer) + sizeof(struct ifinfomsg),
	367	nla_len(nla_peer) - sizeof(struct ifinfomsg));
	368	if (err < 0)
	369	return err;
	370
	371	err = veth_validate(peer_tb, NULL);
	372	if (err < 0)
	373	return err;
	374
	375	tbp = peer_tb;
	376	} else {
	377	ifmp = NULL;
	378	tbp = tb;
	379	}
	380
	381	if (tbp[IFLA_IFNAME]) {
	382	nla_strlcpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
	383	name_assign_type = NET_NAME_USER;
	384	} else {
	385	snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
	386	name_assign_type = NET_NAME_ENUM;
	387	}
	388
	389	net = rtnl_link_get_net(src_net, tbp);
	390	if (IS_ERR(net))
	391	return PTR_ERR(net);
	392
	393	peer = rtnl_create_link(net, ifname, name_assign_type,
	394	&veth_link_ops, tbp);
	395	if (IS_ERR(peer)) {
	396	put_net(net);
	397	return PTR_ERR(peer);
	398	}
	399
	400	if (tbp[IFLA_ADDRESS] == NULL)
	401	eth_hw_addr_random(peer);
	402
	403	if (ifmp && (dev->ifindex != 0))
	404	peer->ifindex = ifmp->ifi_index;
	405
	406	err = register_netdevice(peer);
	407	put_net(net);
	408	net = NULL;
	409	if (err < 0)
	410	goto err_register_peer;
	411
	412	netif_carrier_off(peer);
	413
	414	err = rtnl_configure_link(peer, ifmp);
	415	if (err < 0)
	416	goto err_configure_peer;
	417
	418	/*
	419	* register dev last
	420	*
	421	* note, that since we've registered new device the dev's name
	422	* should be re-allocated
	423	*/
	424
	425	if (tb[IFLA_ADDRESS] == NULL)
	426	eth_hw_addr_random(dev);
	427
	428	if (tb[IFLA_IFNAME])
	429	nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
	430	else
	431	snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
	432
	433	err = register_netdevice(dev);
	434	if (err < 0)
	435	goto err_register_dev;
	436
	437	netif_carrier_off(dev);
	438
	439	/*
	440	* tie the deviced together
	441	*/
	442
	443	priv = netdev_priv(dev);
	444	rcu_assign_pointer(priv->peer, peer);
	445
	446	priv = netdev_priv(peer);
	447	rcu_assign_pointer(priv->peer, dev);
	448	return 0;
	449
	450	err_register_dev:
	451	/* nothing to do */
	452	err_configure_peer:
	453	unregister_netdevice(peer);
	454	return err;
	455
	456	err_register_peer:
	457	free_netdev(peer);
	458	return err;
	459	}
	460
	461	static void veth_dellink(struct net_device dev, struct list_head head)
	462	{
	463	struct veth_priv *priv;
	464	struct net_device *peer;
	465
	466	priv = netdev_priv(dev);
	467	peer = rtnl_dereference(priv->peer);
	468
	469	/* Note : dellink() is called from default_device_exit_batch(),
	470	* before a rcu_synchronize() point. The devices are guaranteed
	471	* not being freed before one RCU grace period.
	472	*/
	473	RCU_INIT_POINTER(priv->peer, NULL);
	474	unregister_netdevice_queue(dev, head);
	475
	476	if (peer) {
	477	priv = netdev_priv(peer);
	478	RCU_INIT_POINTER(priv->peer, NULL);
	479	unregister_netdevice_queue(peer, head);
	480	}
	481	}
	482
	483	static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
	484	[VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
	485	};
	486
	487	static struct net veth_get_link_net(const struct net_device dev)
	488	{
	489	struct veth_priv *priv = netdev_priv(dev);
	490	struct net_device *peer = rtnl_dereference(priv->peer);
	491
	492	return peer ? dev_net(peer) : dev_net(dev);
	493	}
	494
	495	static struct rtnl_link_ops veth_link_ops = {
	496	.kind = DRV_NAME,
	497	.priv_size = sizeof(struct veth_priv),
	498	.setup = veth_setup,
	499	.validate = veth_validate,
	500	.newlink = veth_newlink,
	501	.dellink = veth_dellink,
	502	.policy = veth_policy,
	503	.maxtype = VETH_INFO_MAX,
	504	.get_link_net = veth_get_link_net,
	505	};
	506
	507	/*
	508	* init/fini
	509	*/
	510
	511	static __init int veth_init(void)
	512	{
	513	return rtnl_link_register(&veth_link_ops);
	514	}
	515
	516	static __exit void veth_exit(void)
	517	{
	518	rtnl_link_unregister(&veth_link_ops);
	519	}
	520
	521	module_init(veth_init);
	522	module_exit(veth_exit);
	523
	524	MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
	525	MODULE_LICENSE("GPL v2");
	526	MODULE_ALIAS_RTNL_LINK(DRV_NAME);