1 files changed, 640 insertions, 235 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 0873cdc..2ac2164 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -68,7 +68,6 @@
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
 #include <net/sock.h>
-#include <net/cls_cgroup.h>
 
 #include <asm/uaccess.h>
 
@@ -110,16 +109,56 @@ struct tap_filter {
 	unsigned char	addr[FLT_EXACT_COUNT][ETH_ALEN];
 };
 
+/* 1024 is probably a high enough limit: modern hypervisors seem to support on
+ * the order of 100-200 CPUs so this leaves us some breathing space if we want
+ * to match a queue per guest CPU.
+ */
+#define MAX_TAP_QUEUES 1024
+
+#define TUN_FLOW_EXPIRE (3 * HZ)
+
+/* A tun_file connects an open character device to a tuntap netdevice. It
+ * also contains all socket related strctures (except sock_fprog and tap_filter)
+ * to serve as one transmit queue for tuntap device. The sock_fprog and
+ * tap_filter were kept in tun_struct since they were used for filtering for the
+ * netdevice not for a specific queue (at least I didn't see the requirement for
+ * this).
+ *
+ * RCU usage:
+ * The tun_file and tun_struct are loosely coupled, the pointer from one to the
+ * other can only be read while rcu_read_lock or rtnl_lock is held.
+ */
 struct tun_file {
-	atomic_t count;
-	struct tun_struct *tun;
+	struct sock sk;
+	struct socket socket;
+	struct socket_wq wq;
+	struct tun_struct __rcu *tun;
 	struct net *net;
+	struct fasync_struct *fasync;
+	/* only used for fasnyc */
+	unsigned int flags;
+	u16 queue_index;
+};
+
+struct tun_flow_entry {
+	struct hlist_node hash_link;
+	struct rcu_head rcu;
+	struct tun_struct *tun;
+
+	u32 rxhash;
+	int queue_index;
+	unsigned long updated;
 };
 
-struct tun_sock;
+#define TUN_NUM_FLOW_ENTRIES 1024
 
+/* Since the socket were moved to tun_file, to preserve the behavior of persist
+ * device, socket filter, sndbuf and vnet header size were restore when the
+ * file were attached to a persist device.
+ */
 struct tun_struct {
-	struct tun_file		*tfile;
+	struct tun_file __rcu	*tfiles[MAX_TAP_QUEUES];
+	unsigned int            numqueues;
 	unsigned int 		flags;
 	kuid_t			owner;
 	kgid_t			group;
@@ -128,88 +167,349 @@ struct tun_struct {
 	netdev_features_t	set_features;
 #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
 			  NETIF_F_TSO6|NETIF_F_UFO)
-	struct fasync_struct	*fasync;
-
-	struct tap_filter       txflt;
-	struct socket		socket;
-	struct socket_wq	wq;
 
 	int			vnet_hdr_sz;
-
+	int			sndbuf;
+	struct tap_filter	txflt;
+	struct sock_fprog	fprog;
+	/* protected by rtnl lock */
+	bool			filter_attached;
 #ifdef TUN_DEBUG
 	int debug;
 #endif
+	spinlock_t lock;
+	struct kmem_cache *flow_cache;
+	struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
+	struct timer_list flow_gc_timer;
+	unsigned long ageing_time;
 };
 
-struct tun_sock {
-	struct sock		sk;
-	struct tun_struct	*tun;
-};
+static inline u32 tun_hashfn(u32 rxhash)
+{
+	return rxhash & 0x3ff;
+}
 
-static inline struct tun_sock *tun_sk(struct sock *sk)
+static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
 {
-	return container_of(sk, struct tun_sock, sk);
+	struct tun_flow_entry *e;
+	struct hlist_node *n;
+
+	hlist_for_each_entry_rcu(e, n, head, hash_link) {
+		if (e->rxhash == rxhash)
+			return e;
+	}
+	return NULL;
 }
 
-static int tun_attach(struct tun_struct *tun, struct file *file)
+static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
+					      struct hlist_head *head,
+					      u32 rxhash, u16 queue_index)
 {
-	struct tun_file *tfile = file->private_data;
-	int err;
+	struct tun_flow_entry *e = kmem_cache_alloc(tun->flow_cache,
+						    GFP_ATOMIC);
+	if (e) {
+		tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
+			  rxhash, queue_index);
+		e->updated = jiffies;
+		e->rxhash = rxhash;
+		e->queue_index = queue_index;
+		e->tun = tun;
+		hlist_add_head_rcu(&e->hash_link, head);
+	}
+	return e;
+}
 
-	ASSERT_RTNL();
+static void tun_flow_free(struct rcu_head *head)
+{
+	struct tun_flow_entry *e
+		= container_of(head, struct tun_flow_entry, rcu);
+	kmem_cache_free(e->tun->flow_cache, e);
+}
 
-	netif_tx_lock_bh(tun->dev);
+static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
+{
+	tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
+		  e->rxhash, e->queue_index);
+	hlist_del_rcu(&e->hash_link);
+	call_rcu(&e->rcu, tun_flow_free);
+}
 
-	err = -EINVAL;
-	if (tfile->tun)
-		goto out;
+static void tun_flow_flush(struct tun_struct *tun)
+{
+	int i;
 
-	err = -EBUSY;
-	if (tun->tfile)
-		goto out;
+	spin_lock_bh(&tun->lock);
+	for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
+		struct tun_flow_entry *e;
+		struct hlist_node *h, *n;
 
-	err = 0;
-	tfile->tun = tun;
-	tun->tfile = tfile;
-	tun->socket.file = file;
-	netif_carrier_on(tun->dev);
-	dev_hold(tun->dev);
-	sock_hold(tun->socket.sk);
-	atomic_inc(&tfile->count);
+		hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link)
+			tun_flow_delete(tun, e);
+	}
+	spin_unlock_bh(&tun->lock);
+}
 
-out:
-	netif_tx_unlock_bh(tun->dev);
-	return err;
+static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
+{
+	int i;
+
+	spin_lock_bh(&tun->lock);
+	for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
+		struct tun_flow_entry *e;
+		struct hlist_node *h, *n;
+
+		hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
+			if (e->queue_index == queue_index)
+				tun_flow_delete(tun, e);
+		}
+	}
+	spin_unlock_bh(&tun->lock);
 }
 
-static void __tun_detach(struct tun_struct *tun)
+static void tun_flow_cleanup(unsigned long data)
 {
-	/* Detach from net device */
-	netif_tx_lock_bh(tun->dev);
-	netif_carrier_off(tun->dev);
-	tun->tfile = NULL;
-	netif_tx_unlock_bh(tun->dev);
+	struct tun_struct *tun = (struct tun_struct *)data;
+	unsigned long delay = tun->ageing_time;
+	unsigned long next_timer = jiffies + delay;
+	unsigned long count = 0;
+	int i;
 
-	/* Drop read queue */
-	skb_queue_purge(&tun->socket.sk->sk_receive_queue);
+	tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
+
+	spin_lock_bh(&tun->lock);
+	for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
+		struct tun_flow_entry *e;
+		struct hlist_node *h, *n;
+
+		hlist_for_each_entry_safe(e, h, n, &tun->flows[i], hash_link) {
+			unsigned long this_timer;
+			count++;
+			this_timer = e->updated + delay;
+			if (time_before_eq(this_timer, jiffies))
+				tun_flow_delete(tun, e);
+			else if (time_before(this_timer, next_timer))
+				next_timer = this_timer;
+		}
+	}
 
-	/* Drop the extra count on the net device */
-	dev_put(tun->dev);
+	if (count)
+		mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
+	spin_unlock_bh(&tun->lock);
 }
 
-static void tun_detach(struct tun_struct *tun)
+static void tun_flow_update(struct tun_struct *tun, struct sk_buff *skb,
+			    u16 queue_index)
+{
+	struct hlist_head *head;
+	struct tun_flow_entry *e;
+	unsigned long delay = tun->ageing_time;
+	u32 rxhash = skb_get_rxhash(skb);
+
+	if (!rxhash)
+		return;
+	else
+		head = &tun->flows[tun_hashfn(rxhash)];
+
+	rcu_read_lock();
+
+	if (tun->numqueues == 1)
+		goto unlock;
+
+	e = tun_flow_find(head, rxhash);
+	if (likely(e)) {
+		/* TODO: keep queueing to old queue until it's empty? */
+		e->queue_index = queue_index;
+		e->updated = jiffies;
+	} else {
+		spin_lock_bh(&tun->lock);
+		if (!tun_flow_find(head, rxhash))
+			tun_flow_create(tun, head, rxhash, queue_index);
+
+		if (!timer_pending(&tun->flow_gc_timer))
+			mod_timer(&tun->flow_gc_timer,
+				  round_jiffies_up(jiffies + delay));
+		spin_unlock_bh(&tun->lock);
+	}
+
+unlock:
+	rcu_read_unlock();
+}
+
+/* We try to identify a flow through its rxhash first. The reason that
+ * we do not check rxq no. is becuase some cards(e.g 82599), chooses
+ * the rxq based on the txq where the last packet of the flow comes. As
+ * the userspace application move between processors, we may get a
+ * different rxq no. here. If we could not get rxhash, then we would
+ * hope the rxq no. may help here.
+ */
+static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+	struct tun_flow_entry *e;
+	u32 txq = 0;
+	u32 numqueues = 0;
+
+	rcu_read_lock();
+	numqueues = tun->numqueues;
+
+	txq = skb_get_rxhash(skb);
+	if (txq) {
+		e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
+		if (e)
+			txq = e->queue_index;
+		else
+			/* use multiply and shift instead of expensive divide */
+			txq = ((u64)txq * numqueues) >> 32;
+	} else if (likely(skb_rx_queue_recorded(skb))) {
+		txq = skb_get_rx_queue(skb);
+		while (unlikely(txq >= numqueues))
+			txq -= numqueues;
+	}
+
+	rcu_read_unlock();
+	return txq;
+}
+
+static inline bool tun_not_capable(struct tun_struct *tun)
+{
+	const struct cred *cred = current_cred();
+	struct net *net = dev_net(tun->dev);
+
+	return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
+		  (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
+		!ns_capable(net->user_ns, CAP_NET_ADMIN);
+}
+
+static void tun_set_real_num_queues(struct tun_struct *tun)
+{
+	netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
+	netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
+}
+
+static void __tun_detach(struct tun_file *tfile, bool clean)
+{
+	struct tun_file *ntfile;
+	struct tun_struct *tun;
+	struct net_device *dev;
+
+	tun = rcu_dereference_protected(tfile->tun,
+					lockdep_rtnl_is_held());
+	if (tun) {
+		u16 index = tfile->queue_index;
+		BUG_ON(index >= tun->numqueues);
+		dev = tun->dev;
+
+		rcu_assign_pointer(tun->tfiles[index],
+				   tun->tfiles[tun->numqueues - 1]);
+		rcu_assign_pointer(tfile->tun, NULL);
+		ntfile = rcu_dereference_protected(tun->tfiles[index],
+						   lockdep_rtnl_is_held());
+		ntfile->queue_index = index;
+
+		--tun->numqueues;
+		sock_put(&tfile->sk);
+
+		synchronize_net();
+		tun_flow_delete_by_queue(tun, tun->numqueues + 1);
+		/* Drop read queue */
+		skb_queue_purge(&tfile->sk.sk_receive_queue);
+		tun_set_real_num_queues(tun);
+
+		if (tun->numqueues == 0 && !(tun->flags & TUN_PERSIST))
+			if (dev->reg_state == NETREG_REGISTERED)
+				unregister_netdevice(dev);
+	}
+
+	if (clean) {
+		BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED,
+				 &tfile->socket.flags));
+		sk_release_kernel(&tfile->sk);
+	}
+}
+
+static void tun_detach(struct tun_file *tfile, bool clean)
 {
 	rtnl_lock();
-	__tun_detach(tun);
+	__tun_detach(tfile, clean);
 	rtnl_unlock();
 }
 
+static void tun_detach_all(struct net_device *dev)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+	struct tun_file *tfile;
+	int i, n = tun->numqueues;
+
+	for (i = 0; i < n; i++) {
+		tfile = rcu_dereference_protected(tun->tfiles[i],
+						  lockdep_rtnl_is_held());
+		BUG_ON(!tfile);
+		wake_up_all(&tfile->wq.wait);
+		rcu_assign_pointer(tfile->tun, NULL);
+		--tun->numqueues;
+	}
+	BUG_ON(tun->numqueues != 0);
+
+	synchronize_net();
+	for (i = 0; i < n; i++) {
+		tfile = rcu_dereference_protected(tun->tfiles[i],
+						  lockdep_rtnl_is_held());
+		/* Drop read queue */
+		skb_queue_purge(&tfile->sk.sk_receive_queue);
+		sock_put(&tfile->sk);
+	}
+}
+
+static int tun_attach(struct tun_struct *tun, struct file *file)
+{
+	struct tun_file *tfile = file->private_data;
+	int err;
+
+	err = -EINVAL;
+	if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
+		goto out;
+
+	err = -EBUSY;
+	if (!(tun->flags & TUN_TAP_MQ) && tun->numqueues == 1)
+		goto out;
+
+	err = -E2BIG;
+	if (tun->numqueues == MAX_TAP_QUEUES)
+		goto out;
+
+	err = 0;
+
+	/* Re-attach the filter to presist device */
+	if (tun->filter_attached == true) {
+		err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+		if (!err)
+			goto out;
+	}
+	tfile->queue_index = tun->numqueues;
+	rcu_assign_pointer(tfile->tun, tun);
+	rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
+	sock_hold(&tfile->sk);
+	tun->numqueues++;
+
+	tun_set_real_num_queues(tun);
+
+	/* device is allowed to go away first, so no need to hold extra
+	 * refcnt.
+	 */
+
+out:
+	return err;
+}
+
 static struct tun_struct *__tun_get(struct tun_file *tfile)
 {
-	struct tun_struct *tun = NULL;
+	struct tun_struct *tun;
 
-	if (atomic_inc_not_zero(&tfile->count))
-		tun = tfile->tun;
+	rcu_read_lock();
+	tun = rcu_dereference(tfile->tun);
+	if (tun)
+		dev_hold(tun->dev);
+	rcu_read_unlock();
 
 	return tun;
 }
@@ -221,10 +521,7 @@ static struct tun_struct *tun_get(struct file *file)
 
 static void tun_put(struct tun_struct *tun)
 {
-	struct tun_file *tfile = tun->tfile;
-
-	if (atomic_dec_and_test(&tfile->count))
-		tun_detach(tfile->tun);
+	dev_put(tun->dev);
 }
 
 /* TAP filtering */
@@ -344,38 +641,20 @@ static const struct ethtool_ops tun_ethtool_ops;
 /* Net device detach from fd. */
 static void tun_net_uninit(struct net_device *dev)
 {
-	struct tun_struct *tun = netdev_priv(dev);
-	struct tun_file *tfile = tun->tfile;
-
-	/* Inform the methods they need to stop using the dev.
-	 */
-	if (tfile) {
-		wake_up_all(&tun->wq.wait);
-		if (atomic_dec_and_test(&tfile->count))
-			__tun_detach(tun);
-	}
-}
-
-static void tun_free_netdev(struct net_device *dev)
-{
-	struct tun_struct *tun = netdev_priv(dev);
-
-	BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags));
-
-	sk_release_kernel(tun->socket.sk);
+	tun_detach_all(dev);
 }
 
 /* Net device open. */
 static int tun_net_open(struct net_device *dev)
 {
-	netif_start_queue(dev);
+	netif_tx_start_all_queues(dev);
 	return 0;
 }
 
 /* Net device close. */
 static int tun_net_close(struct net_device *dev)
 {
-	netif_stop_queue(dev);
+	netif_tx_stop_all_queues(dev);
 	return 0;
 }
 
@@ -383,38 +662,36 @@ static int tun_net_close(struct net_device *dev)
 static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct tun_struct *tun = netdev_priv(dev);
+	int txq = skb->queue_mapping;
+	struct tun_file *tfile;
 
-	tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
+	rcu_read_lock();
+	tfile = rcu_dereference(tun->tfiles[txq]);
 
 	/* Drop packet if interface is not attached */
-	if (!tun->tfile)
+	if (txq >= tun->numqueues)
 		goto drop;
 
+	tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
+
+	BUG_ON(!tfile);
+
 	/* Drop if the filter does not like it.
 	 * This is a noop if the filter is disabled.
 	 * Filter can be enabled only for the TAP devices. */
 	if (!check_filter(&tun->txflt, skb))
 		goto drop;
 
-	if (tun->socket.sk->sk_filter &&
-	    sk_filter(tun->socket.sk, skb))
+	if (tfile->socket.sk->sk_filter &&
+	    sk_filter(tfile->socket.sk, skb))
 		goto drop;
 
-	if (skb_queue_len(&tun->socket.sk->sk_receive_queue) >= dev->tx_queue_len) {
-		if (!(tun->flags & TUN_ONE_QUEUE)) {
-			/* Normal queueing mode. */
-			/* Packet scheduler handles dropping of further packets. */
-			netif_stop_queue(dev);
-
-			/* We won't see all dropped packets individually, so overrun
-			 * error is more appropriate. */
-			dev->stats.tx_fifo_errors++;
-		} else {
-			/* Single queue mode.
-			 * Driver handles dropping of all packets itself. */
-			goto drop;
-		}
-	}
+	/* Limit the number of packets queued by dividing txq length with the
+	 * number of queues.
+	 */
+	if (skb_queue_len(&tfile->socket.sk->sk_receive_queue)
+			  >= dev->tx_queue_len / tun->numqueues)
+		goto drop;
 
 	/* Orphan the skb - required as we might hang on to it
 	 * for indefinite time. */
@@ -423,18 +700,22 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb_orphan(skb);
 
 	/* Enqueue packet */
-	skb_queue_tail(&tun->socket.sk->sk_receive_queue, skb);
+	skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);
 
 	/* Notify and wake up reader process */
-	if (tun->flags & TUN_FASYNC)
-		kill_fasync(&tun->fasync, SIGIO, POLL_IN);
-	wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
+	if (tfile->flags & TUN_FASYNC)
+		kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
+	wake_up_interruptible_poll(&tfile->wq.wait, POLLIN |
 				   POLLRDNORM | POLLRDBAND);
+
+	rcu_read_unlock();
 	return NETDEV_TX_OK;
 
 drop:
 	dev->stats.tx_dropped++;
+	skb_tx_error(skb);
 	kfree_skb(skb);
+	rcu_read_unlock();
 	return NETDEV_TX_OK;
 }
 
@@ -490,6 +771,7 @@ static const struct net_device_ops tun_netdev_ops = {
 	.ndo_start_xmit		= tun_net_xmit,
 	.ndo_change_mtu		= tun_net_change_mtu,
 	.ndo_fix_features	= tun_net_fix_features,
+	.ndo_select_queue	= tun_select_queue,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= tun_poll_controller,
 #endif
@@ -505,11 +787,43 @@ static const struct net_device_ops tap_netdev_ops = {
 	.ndo_set_rx_mode	= tun_net_mclist,
 	.ndo_set_mac_address	= eth_mac_addr,
 	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_select_queue	= tun_select_queue,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= tun_poll_controller,
 #endif
 };
 
+static int tun_flow_init(struct tun_struct *tun)
+{
+	int i;
+
+	tun->flow_cache = kmem_cache_create("tun_flow_cache",
+					    sizeof(struct tun_flow_entry), 0, 0,
+					    NULL);
+	if (!tun->flow_cache)
+		return -ENOMEM;
+
+	for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
+		INIT_HLIST_HEAD(&tun->flows[i]);
+
+	tun->ageing_time = TUN_FLOW_EXPIRE;
+	setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
+	mod_timer(&tun->flow_gc_timer,
+		  round_jiffies_up(jiffies + tun->ageing_time));
+
+	return 0;
+}
+
+static void tun_flow_uninit(struct tun_struct *tun)
+{
+	del_timer_sync(&tun->flow_gc_timer);
+	tun_flow_flush(tun);
+
+	/* Wait for completion of call_rcu()'s */
+	rcu_barrier();
+	kmem_cache_destroy(tun->flow_cache);
+}
+
 /* Initialize net device. */
 static void tun_net_init(struct net_device *dev)
 {
@@ -535,6 +849,7 @@ static void tun_net_init(struct net_device *dev)
 		/* Ethernet TAP Device */
 		ether_setup(dev);
 		dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+		dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
 
 		eth_hw_addr_random(dev);
 
@@ -546,7 +861,7 @@ static void tun_net_init(struct net_device *dev)
 /* Character device part */
 
 /* Poll */
-static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
+static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
 {
 	struct tun_file *tfile = file->private_data;
 	struct tun_struct *tun = __tun_get(tfile);
@@ -556,11 +871,11 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 	if (!tun)
 		return POLLERR;
 
-	sk = tun->socket.sk;
+	sk = tfile->socket.sk;
 
 	tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
 
-	poll_wait(file, &tun->wq.wait, wait);
+	poll_wait(file, &tfile->wq.wait, wait);
 
 	if (!skb_queue_empty(&sk->sk_receive_queue))
 		mask |= POLLIN | POLLRDNORM;
@@ -579,16 +894,14 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 
 /* prepad is the amount to reserve at front.  len is length after that.
  * linear is a hint as to how much to copy (usually headers). */
-static struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
+static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
 				     size_t prepad, size_t len,
 				     size_t linear, int noblock)
 {
-	struct sock *sk = tun->socket.sk;
+	struct sock *sk = tfile->socket.sk;
 	struct sk_buff *skb;
 	int err;
 
-	sock_update_classid(sk);
-
 	/* Under a page?  Don't bother with paged skb. */
 	if (prepad + len < PAGE_SIZE || !linear)
 		linear = len;
@@ -685,9 +998,9 @@ static int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *from,
 }
 
 /* Get packet from user space buffer */
-static ssize_t tun_get_user(struct tun_struct *tun, void *msg_control,
-			    const struct iovec *iv, size_t total_len,
-			    size_t count, int noblock)
+static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
+			    void *msg_control, const struct iovec *iv,
+			    size_t total_len, size_t count, int noblock)
 {
 	struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
 	struct sk_buff *skb;
@@ -757,7 +1070,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, void *msg_control,
 	} else
 		copylen = len;
 
-	skb = tun_alloc_skb(tun, align, copylen, gso.hdr_len, noblock);
+	skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
 	if (IS_ERR(skb)) {
 		if (PTR_ERR(skb) != -EAGAIN)
 			tun->dev->stats.rx_dropped++;
@@ -854,6 +1167,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, void *msg_control,
 	tun->dev->stats.rx_packets++;
 	tun->dev->stats.rx_bytes += len;
 
+	tun_flow_update(tun, skb, tfile->queue_index);
 	return total_len;
 }
 
@@ -862,6 +1176,7 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 {
 	struct file *file = iocb->ki_filp;
 	struct tun_struct *tun = tun_get(file);
+	struct tun_file *tfile = file->private_data;
 	ssize_t result;
 
 	if (!tun)
@@ -869,8 +1184,8 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 
 	tun_debug(KERN_INFO, tun, "tun_chr_write %ld\n", count);
 
-	result = tun_get_user(tun, NULL, iv, iov_length(iv, count), count,
-			      file->f_flags & O_NONBLOCK);
+	result = tun_get_user(tun, tfile, NULL, iv, iov_length(iv, count),
+			      count, file->f_flags & O_NONBLOCK);
 
 	tun_put(tun);
 	return result;
@@ -878,6 +1193,7 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 
 /* Put packet to the user space buffer */
 static ssize_t tun_put_user(struct tun_struct *tun,
+			    struct tun_file *tfile,
 			    struct sk_buff *skb,
 			    const struct iovec *iv, int len)
 {
@@ -957,7 +1273,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 	return total;
 }
 
-static ssize_t tun_do_read(struct tun_struct *tun,
+static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
 			   struct kiocb *iocb, const struct iovec *iv,
 			   ssize_t len, int noblock)
 {
@@ -965,15 +1281,15 @@ static ssize_t tun_do_read(struct tun_struct *tun,
 	struct sk_buff *skb;
 	ssize_t ret = 0;
 
-	tun_debug(KERN_INFO, tun, "tun_chr_read\n");
+	tun_debug(KERN_INFO, tun, "tun_do_read\n");
 
 	if (unlikely(!noblock))
-		add_wait_queue(&tun->wq.wait, &wait);
+		add_wait_queue(&tfile->wq.wait, &wait);
 	while (len) {
 		current->state = TASK_INTERRUPTIBLE;
 
 		/* Read frames from the queue */
-		if (!(skb=skb_dequeue(&tun->socket.sk->sk_receive_queue))) {
+		if (!(skb = skb_dequeue(&tfile->socket.sk->sk_receive_queue))) {
 			if (noblock) {
 				ret = -EAGAIN;
 				break;
@@ -991,16 +1307,15 @@ static ssize_t tun_do_read(struct tun_struct *tun,
 			schedule();
 			continue;
 		}
-		netif_wake_queue(tun->dev);
 
-		ret = tun_put_user(tun, skb, iv, len);
+		ret = tun_put_user(tun, tfile, skb, iv, len);
 		kfree_skb(skb);
 		break;
 	}
 
 	current->state = TASK_RUNNING;
 	if (unlikely(!noblock))
-		remove_wait_queue(&tun->wq.wait, &wait);
+		remove_wait_queue(&tfile->wq.wait, &wait);
 
 	return ret;
 }
@@ -1021,13 +1336,22 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
 		goto out;
 	}
 
-	ret = tun_do_read(tun, iocb, iv, len, file->f_flags & O_NONBLOCK);
+	ret = tun_do_read(tun, tfile, iocb, iv, len,
+			  file->f_flags & O_NONBLOCK);
 	ret = min_t(ssize_t, ret, len);
 out:
 	tun_put(tun);
 	return ret;
 }
 
+static void tun_free_netdev(struct net_device *dev)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+
+	tun_flow_uninit(tun);
+	free_netdev(dev);
+}
+
 static void tun_setup(struct net_device *dev)
 {
 	struct tun_struct *tun = netdev_priv(dev);
@@ -1056,7 +1380,7 @@ static struct rtnl_link_ops tun_link_ops __read_mostly = {
 
 static void tun_sock_write_space(struct sock *sk)
 {
-	struct tun_struct *tun;
+	struct tun_file *tfile;
 	wait_queue_head_t *wqueue;
 
 	if (!sock_writeable(sk))
@@ -1070,37 +1394,46 @@ static void tun_sock_write_space(struct sock *sk)
 		wake_up_interruptible_sync_poll(wqueue, POLLOUT |
 						POLLWRNORM | POLLWRBAND);
 
-	tun = tun_sk(sk)->tun;
-	kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
-}
-
-static void tun_sock_destruct(struct sock *sk)
-{
-	free_netdev(tun_sk(sk)->tun->dev);
+	tfile = container_of(sk, struct tun_file, sk);
+	kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
 }
 
 static int tun_sendmsg(struct kiocb *iocb, struct socket *sock,
 		       struct msghdr *m, size_t total_len)
 {
-	struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
-	return tun_get_user(tun, m->msg_control, m->msg_iov, total_len,
-			    m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
+	int ret;
+	struct tun_file *tfile = container_of(sock, struct tun_file, socket);
+	struct tun_struct *tun = __tun_get(tfile);
+
+	if (!tun)
+		return -EBADFD;
+	ret = tun_get_user(tun, tfile, m->msg_control, m->msg_iov, total_len,
+			   m->msg_iovlen, m->msg_flags & MSG_DONTWAIT);
+	tun_put(tun);
+	return ret;
 }
 
+
 static int tun_recvmsg(struct kiocb *iocb, struct socket *sock,
 		       struct msghdr *m, size_t total_len,
 		       int flags)
 {
-	struct tun_struct *tun = container_of(sock, struct tun_struct, socket);
+	struct tun_file *tfile = container_of(sock, struct tun_file, socket);
+	struct tun_struct *tun = __tun_get(tfile);
 	int ret;
+
+	if (!tun)
+		return -EBADFD;
+
 	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
 		return -EINVAL;
-	ret = tun_do_read(tun, iocb, m->msg_iov, total_len,
+	ret = tun_do_read(tun, tfile, iocb, m->msg_iov, total_len,
 			  flags & MSG_DONTWAIT);
 	if (ret > total_len) {
 		m->msg_flags |= MSG_TRUNC;
 		ret = flags & MSG_TRUNC ? ret : total_len;
 	}
+	tun_put(tun);
 	return ret;
 }
 
@@ -1121,7 +1454,7 @@ static const struct proto_ops tun_socket_ops = {
 static struct proto tun_proto = {
 	.name		= "tun",
 	.owner		= THIS_MODULE,
-	.obj_size	= sizeof(struct tun_sock),
+	.obj_size	= sizeof(struct tun_file),
 };
 
 static int tun_flags(struct tun_struct *tun)
@@ -1136,12 +1469,18 @@ static int tun_flags(struct tun_struct *tun)
 	if (tun->flags & TUN_NO_PI)
 		flags |= IFF_NO_PI;
 
+	/* This flag has no real effect.  We track the value for backwards
+	 * compatibility.
+	 */
 	if (tun->flags & TUN_ONE_QUEUE)
 		flags |= IFF_ONE_QUEUE;
 
 	if (tun->flags & TUN_VNET_HDR)
 		flags |= IFF_VNET_HDR;
 
+	if (tun->flags & TUN_TAP_MQ)
+		flags |= IFF_MULTI_QUEUE;
+
 	return flags;
 }
 
@@ -1178,15 +1517,13 @@ static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
 
 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 {
-	struct sock *sk;
 	struct tun_struct *tun;
+	struct tun_file *tfile = file->private_data;
 	struct net_device *dev;
 	int err;
 
 	dev = __dev_get_by_name(net, ifr->ifr_name);
 	if (dev) {
-		const struct cred *cred = current_cred();
-
 		if (ifr->ifr_flags & IFF_TUN_EXCL)
 			return -EBUSY;
 		if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
@@ -1196,11 +1533,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		else
 			return -EINVAL;
 
-		if (((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
-		     (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
-		    !capable(CAP_NET_ADMIN))
+		if (tun_not_capable(tun))
 			return -EPERM;
-		err = security_tun_dev_attach(tun->socket.sk);
+		err = security_tun_dev_attach(tfile->socket.sk);
 		if (err < 0)
 			return err;
 
@@ -1212,7 +1547,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		char *name;
 		unsigned long flags = 0;
 
-		if (!capable(CAP_NET_ADMIN))
+		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
 			return -EPERM;
 		err = security_tun_dev_create();
 		if (err < 0)
@@ -1233,8 +1568,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		if (*ifr->ifr_name)
 			name = ifr->ifr_name;
 
-		dev = alloc_netdev(sizeof(struct tun_struct), name,
-				   tun_setup);
+		dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
+				       tun_setup,
+				       MAX_TAP_QUEUES, MAX_TAP_QUEUES);
 		if (!dev)
 			return -ENOMEM;
 
@@ -1246,46 +1582,38 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		tun->flags = flags;
 		tun->txflt.count = 0;
 		tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
-		set_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags);
-
-		err = -ENOMEM;
-		sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
-		if (!sk)
-			goto err_free_dev;
 
-		sk_change_net(sk, net);
-		tun->socket.wq = &tun->wq;
-		init_waitqueue_head(&tun->wq.wait);
-		tun->socket.ops = &tun_socket_ops;
-		sock_init_data(&tun->socket, sk);
-		sk->sk_write_space = tun_sock_write_space;
-		sk->sk_sndbuf = INT_MAX;
-		sock_set_flag(sk, SOCK_ZEROCOPY);
+		tun->filter_attached = false;
+		tun->sndbuf = tfile->socket.sk->sk_sndbuf;
 
-		tun_sk(sk)->tun = tun;
+		spin_lock_init(&tun->lock);
 
-		security_tun_dev_post_create(sk);
+		security_tun_dev_post_create(&tfile->sk);
 
 		tun_net_init(dev);
 
+		err = tun_flow_init(tun);
+		if (err < 0)
+			goto err_free_dev;
+
 		dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
 			TUN_USER_FEATURES;
 		dev->features = dev->hw_features;
 
+		err = tun_attach(tun, file);
+		if (err < 0)
+			goto err_free_dev;
+
 		err = register_netdevice(tun->dev);
 		if (err < 0)
-			goto err_free_sk;
+			goto err_free_dev;
 
 		if (device_create_file(&tun->dev->dev, &dev_attr_tun_flags) ||
 		    device_create_file(&tun->dev->dev, &dev_attr_owner) ||
 		    device_create_file(&tun->dev->dev, &dev_attr_group))
 			pr_err("Failed to create tun sysfs files\n");
 
-		sk->sk_destruct = tun_sock_destruct;
-
-		err = tun_attach(tun, file);
-		if (err < 0)
-			goto failed;
+		netif_carrier_on(tun->dev);
 	}
 
 	tun_debug(KERN_INFO, tun, "tun_set_iff\n");
@@ -1295,6 +1623,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 	else
 		tun->flags &= ~TUN_NO_PI;
 
+	/* This flag has no real effect.  We track the value for backwards
+	 * compatibility.
+	 */
 	if (ifr->ifr_flags & IFF_ONE_QUEUE)
 		tun->flags |= TUN_ONE_QUEUE;
 	else
@@ -1305,24 +1636,26 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 	else
 		tun->flags &= ~TUN_VNET_HDR;
 
+	if (ifr->ifr_flags & IFF_MULTI_QUEUE)
+		tun->flags |= TUN_TAP_MQ;
+	else
+		tun->flags &= ~TUN_TAP_MQ;
+
 	/* Make sure persistent devices do not get stuck in
 	 * xoff state.
 	 */
 	if (netif_running(tun->dev))
-		netif_wake_queue(tun->dev);
+		netif_tx_wake_all_queues(tun->dev);
 
 	strcpy(ifr->ifr_name, tun->dev->name);
 	return 0;
 
- err_free_sk:
-	tun_free_netdev(dev);
  err_free_dev:
 	free_netdev(dev);
- failed:
 	return err;
 }
 
-static int tun_get_iff(struct net *net, struct tun_struct *tun,
+static void tun_get_iff(struct net *net, struct tun_struct *tun,
 		       struct ifreq *ifr)
 {
 	tun_debug(KERN_INFO, tun, "tun_get_iff\n");
@@ -1331,7 +1664,6 @@ static int tun_get_iff(struct net *net, struct tun_struct *tun,
 
 	ifr->ifr_flags = tun_flags(tun);
 
-	return 0;
 }
 
 /* This is like a cut-down ethtool ops, except done via tun fd so no
@@ -1373,13 +1705,91 @@ static int set_offload(struct tun_struct *tun, unsigned long arg)
 	return 0;
 }
 
+static void tun_detach_filter(struct tun_struct *tun, int n)
+{
+	int i;
+	struct tun_file *tfile;
+
+	for (i = 0; i < n; i++) {
+		tfile = rcu_dereference_protected(tun->tfiles[i],
+						  lockdep_rtnl_is_held());
+		sk_detach_filter(tfile->socket.sk);
+	}
+
+	tun->filter_attached = false;
+}
+
+static int tun_attach_filter(struct tun_struct *tun)
+{
+	int i, ret = 0;
+	struct tun_file *tfile;
+
+	for (i = 0; i < tun->numqueues; i++) {
+		tfile = rcu_dereference_protected(tun->tfiles[i],
+						  lockdep_rtnl_is_held());
+		ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+		if (ret) {
+			tun_detach_filter(tun, i);
+			return ret;
+		}
+	}
+
+	tun->filter_attached = true;
+	return ret;
+}
+
+static void tun_set_sndbuf(struct tun_struct *tun)
+{
+	struct tun_file *tfile;
+	int i;
+
+	for (i = 0; i < tun->numqueues; i++) {
+		tfile = rcu_dereference_protected(tun->tfiles[i],
+						lockdep_rtnl_is_held());
+		tfile->socket.sk->sk_sndbuf = tun->sndbuf;
+	}
+}
+
+static int tun_set_queue(struct file *file, struct ifreq *ifr)
+{
+	struct tun_file *tfile = file->private_data;
+	struct tun_struct *tun;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+
+	if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
+		dev = __dev_get_by_name(tfile->net, ifr->ifr_name);
+		if (!dev) {
+			ret = -EINVAL;
+			goto unlock;
+		}
+
+		tun = netdev_priv(dev);
+		if (dev->netdev_ops != &tap_netdev_ops &&
+			dev->netdev_ops != &tun_netdev_ops)
+			ret = -EINVAL;
+		else if (tun_not_capable(tun))
+			ret = -EPERM;
+		else
+			ret = tun_attach(tun, file);
+	} else if (ifr->ifr_flags & IFF_DETACH_QUEUE)
+		__tun_detach(tfile, false);
+	else
+		ret = -EINVAL;
+
+unlock:
+	rtnl_unlock();
+	return ret;
+}
+
 static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg, int ifreq_len)
 {
 	struct tun_file *tfile = file->private_data;
 	struct tun_struct *tun;
 	void __user* argp = (void __user*)arg;
-	struct sock_fprog fprog;
 	struct ifreq ifr;
 	kuid_t owner;
 	kgid_t group;
@@ -1387,7 +1797,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	int vnet_hdr_sz;
 	int ret;
 
-	if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {
+	if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
 		if (copy_from_user(&ifr, argp, ifreq_len))
 			return -EFAULT;
 	} else {
@@ -1398,10 +1808,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		 * This is needed because we never checked for invalid flags on
 		 * TUNSETIFF. */
 		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |
-				IFF_VNET_HDR,
+				IFF_VNET_HDR | IFF_MULTI_QUEUE,
 				(unsigned int __user*)argp);
-	}
+	} else if (cmd == TUNSETQUEUE)
+		return tun_set_queue(file, &ifr);
 
+	ret = 0;
 	rtnl_lock();
 
 	tun = __tun_get(tfile);
@@ -1422,14 +1834,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 	if (!tun)
 		goto unlock;
 
-	tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %d\n", cmd);
+	tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
 
 	ret = 0;
 	switch (cmd) {
 	case TUNGETIFF:
-		ret = tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
-		if (ret)
-			break;
+		tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
 
 		if (copy_to_user(argp, &ifr, ifreq_len))
 			ret = -EFAULT;
@@ -1444,11 +1854,16 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		break;
 
 	case TUNSETPERSIST:
-		/* Disable/Enable persist mode */
-		if (arg)
+		/* Disable/Enable persist mode. Keep an extra reference to the
+		 * module to prevent the module being unprobed.
+		 */
+		if (arg) {
 			tun->flags |= TUN_PERSIST;
-		else
+			__module_get(THIS_MODULE);
+		} else {
 			tun->flags &= ~TUN_PERSIST;
+			module_put(THIS_MODULE);
+		}
 
 		tun_debug(KERN_INFO, tun, "persist %s\n",
 			  arg ? "enabled" : "disabled");
@@ -1462,7 +1877,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 		tun->owner = owner;
-		tun_debug(KERN_INFO, tun, "owner set to %d\n",
+		tun_debug(KERN_INFO, tun, "owner set to %u\n",
 			  from_kuid(&init_user_ns, tun->owner));
 		break;
 
@@ -1474,7 +1889,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 		tun->group = group;
-		tun_debug(KERN_INFO, tun, "group set to %d\n",
+		tun_debug(KERN_INFO, tun, "group set to %u\n",
 			  from_kgid(&init_user_ns, tun->group));
 		break;
 
@@ -1526,7 +1941,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		break;
 
 	case TUNGETSNDBUF:
-		sndbuf = tun->socket.sk->sk_sndbuf;
+		sndbuf = tfile->socket.sk->sk_sndbuf;
 		if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
 			ret = -EFAULT;
 		break;
@@ -1537,7 +1952,8 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 			break;
 		}
 
-		tun->socket.sk->sk_sndbuf = sndbuf;
+		tun->sndbuf = sndbuf;
+		tun_set_sndbuf(tun);
 		break;
 
 	case TUNGETVNETHDRSZ:
@@ -1565,10 +1981,10 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
 			break;
 		ret = -EFAULT;
-		if (copy_from_user(&fprog, argp, sizeof(fprog)))
+		if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
 			break;
 
-		ret = sk_attach_filter(&fprog, tun->socket.sk);
+		ret = tun_attach_filter(tun);
 		break;
 
 	case TUNDETACHFILTER:
@@ -1576,7 +1992,8 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
 		ret = -EINVAL;
 		if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
 			break;
-		ret = sk_detach_filter(tun->socket.sk);
+		ret = 0;
+		tun_detach_filter(tun, tun->numqueues);
 		break;
 
 	default:
@@ -1628,27 +2045,21 @@ static long tun_chr_compat_ioctl(struct file *file,
 
 static int tun_chr_fasync(int fd, struct file *file, int on)
 {
-	struct tun_struct *tun = tun_get(file);
+	struct tun_file *tfile = file->private_data;
 	int ret;
 
-	if (!tun)
-		return -EBADFD;
-
-	tun_debug(KERN_INFO, tun, "tun_chr_fasync %d\n", on);
-
-	if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
+	if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
 		goto out;
 
 	if (on) {
 		ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0);
 		if (ret)
 			goto out;
-		tun->flags |= TUN_FASYNC;
+		tfile->flags |= TUN_FASYNC;
 	} else
-		tun->flags &= ~TUN_FASYNC;
+		tfile->flags &= ~TUN_FASYNC;
 	ret = 0;
 out:
-	tun_put(tun);
 	return ret;
 }
 
@@ -1658,44 +2069,39 @@ static int tun_chr_open(struct inode *inode, struct file * file)
 
 	DBG1(KERN_INFO, "tunX: tun_chr_open\n");
 
-	tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
+	tfile = (struct tun_file *)sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL,
+					    &tun_proto);
 	if (!tfile)
 		return -ENOMEM;
-	atomic_set(&tfile->count, 0);
-	tfile->tun = NULL;
+	rcu_assign_pointer(tfile->tun, NULL);
 	tfile->net = get_net(current->nsproxy->net_ns);
+	tfile->flags = 0;
+
+	rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
+	init_waitqueue_head(&tfile->wq.wait);
+
+	tfile->socket.file = file;
+	tfile->socket.ops = &tun_socket_ops;
+
+	sock_init_data(&tfile->socket, &tfile->sk);
+	sk_change_net(&tfile->sk, tfile->net);
+
+	tfile->sk.sk_write_space = tun_sock_write_space;
+	tfile->sk.sk_sndbuf = INT_MAX;
+
 	file->private_data = tfile;
+	set_bit(SOCK_EXTERNALLY_ALLOCATED, &tfile->socket.flags);
+
 	return 0;
 }
 
 static int tun_chr_close(struct inode *inode, struct file *file)
 {
 	struct tun_file *tfile = file->private_data;
-	struct tun_struct *tun;
-
-	tun = __tun_get(tfile);
-	if (tun) {
-		struct net_device *dev = tun->dev;
-
-		tun_debug(KERN_INFO, tun, "tun_chr_close\n");
-
-		__tun_detach(tun);
-
-		/* If desirable, unregister the netdevice. */
-		if (!(tun->flags & TUN_PERSIST)) {
-			rtnl_lock();
-			if (dev->reg_state == NETREG_REGISTERED)
-				unregister_netdevice(dev);
-			rtnl_unlock();
-		}
-	}
+	struct net *net = tfile->net;
 
-	tun = tfile->tun;
-	if (tun)
-		sock_put(tun->socket.sk);
-
-	put_net(tfile->net);
-	kfree(tfile);
+	tun_detach(tfile, true);
+	put_net(net);
 
 	return 0;
 }
@@ -1822,14 +2228,13 @@ static void tun_cleanup(void)
  * holding a reference to the file for as long as the socket is in use. */
 struct socket *tun_get_socket(struct file *file)
 {
-	struct tun_struct *tun;
+	struct tun_file *tfile;
 	if (file->f_op != &tun_fops)
 		return ERR_PTR(-EINVAL);
-	tun = tun_get(file);
-	if (!tun)
+	tfile = file->private_data;
+	if (!tfile)
 		return ERR_PTR(-EBADFD);
-	tun_put(tun);
-	return &tun->socket;
+	return &tfile->socket;
 }
 EXPORT_SYMBOL_GPL(tun_get_socket);