[PATCHv6 4/7] tap: Abstract type of virtual interface from tap implementation

From: Sainath Grandhi
Date: Fri Feb 10 2017 - 19:06:03 EST


macvlan object is re-structured to hold tap related elements in a separate
entity, tap_dev. Upon NETDEV_REGISTER device_event, tap_dev is registered with
idr and fetched again on tap_open. Few of the tap functions are modified to
accepted tap_dev as argument. tap_dev object includes callbacks to be used by
underlying virtual interface to take care of tx and rx accounting.

Signed-off-by: Sainath Grandhi <sainath.grandhi@xxxxxxxxx>
---
drivers/net/macvlan.c | 2 +-
drivers/net/macvtap_main.c | 71 +++++++++---
drivers/net/tap.c | 264 ++++++++++++++++++++-------------------------
include/linux/if_tap.h | 57 +++++++++-
4 files changed, 229 insertions(+), 165 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index cbfc1be..9261722 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -1525,7 +1525,6 @@ static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
int macvlan_link_register(struct rtnl_link_ops *ops)
{
/* common fields */
- ops->priv_size = sizeof(struct macvlan_dev);
ops->validate = macvlan_validate;
ops->maxtype = IFLA_MACVLAN_MAX;
ops->policy = macvlan_policy;
@@ -1548,6 +1547,7 @@ static struct rtnl_link_ops macvlan_link_ops = {
.newlink = macvlan_newlink,
.dellink = macvlan_dellink,
.get_link_net = macvlan_get_link_net,
+ .priv_size = sizeof(struct macvlan_dev),
};

static int macvlan_device_event(struct notifier_block *unused,
diff --git a/drivers/net/macvtap_main.c b/drivers/net/macvtap_main.c
index 215ab7a..0238df6 100644
--- a/drivers/net/macvtap_main.c
+++ b/drivers/net/macvtap_main.c
@@ -24,6 +24,11 @@
#include <linux/virtio_net.h>
#include <linux/skb_array.h>

+struct macvtap_dev {
+ struct macvlan_dev vlan;
+ struct tap_dev tap;
+};
+
/*
* Variables for dealing with macvtaps device numbers.
*/
@@ -46,22 +51,55 @@ static struct cdev macvtap_cdev;
#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
NETIF_F_TSO6 | NETIF_F_UFO)

+static void macvtap_count_tx_dropped(struct tap_dev *tap)
+{
+ struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
+ struct macvlan_dev *vlan = &vlantap->vlan;
+
+ this_cpu_inc(vlan->pcpu_stats->tx_dropped);
+}
+
+static void macvtap_count_rx_dropped(struct tap_dev *tap)
+{
+ struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
+ struct macvlan_dev *vlan = &vlantap->vlan;
+
+ macvlan_count_rx(vlan, 0, 0, 0);
+}
+
+static void macvtap_update_features(struct tap_dev *tap,
+ netdev_features_t features)
+{
+ struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
+ struct macvlan_dev *vlan = &vlantap->vlan;
+
+ vlan->set_features = features;
+ netdev_update_features(vlan->dev);
+}
+
static int macvtap_newlink(struct net *src_net,
struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[])
{
- struct macvlan_dev *vlan = netdev_priv(dev);
+ struct macvtap_dev *vlantap = netdev_priv(dev);
int err;

- INIT_LIST_HEAD(&vlan->queue_list);
+ INIT_LIST_HEAD(&vlantap->tap.queue_list);

/* Since macvlan supports all offloads by default, make
* tap support all offloads also.
*/
- vlan->tap_features = TUN_OFFLOADS;
+ vlantap->tap.tap_features = TUN_OFFLOADS;

- err = netdev_rx_handler_register(dev, tap_handle_frame, vlan);
+ /* Register callbacks for rx/tx drops accounting and updating
+ * net_device features
+ */
+ vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped;
+ vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped;
+ vlantap->tap.update_features = macvtap_update_features;
+
+ err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
if (err)
return err;

@@ -74,14 +112,18 @@ static int macvtap_newlink(struct net *src_net,
return err;
}

+ vlantap->tap.dev = vlantap->vlan.dev;
+
return 0;
}

static void macvtap_dellink(struct net_device *dev,
struct list_head *head)
{
+ struct macvtap_dev *vlantap = netdev_priv(dev);
+
netdev_rx_handler_unregister(dev);
- tap_del_queues(dev);
+ tap_del_queues(&vlantap->tap);
macvlan_dellink(dev, head);
}

@@ -96,13 +138,14 @@ static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
.setup = macvtap_setup,
.newlink = macvtap_newlink,
.dellink = macvtap_dellink,
+ .priv_size = sizeof(struct macvtap_dev),
};

static int macvtap_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct macvlan_dev *vlan;
+ struct macvtap_dev *vlantap;
struct device *classdev;
dev_t devt;
int err;
@@ -112,7 +155,7 @@ static int macvtap_device_event(struct notifier_block *unused,
return NOTIFY_DONE;

snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
- vlan = netdev_priv(dev);
+ vlantap = netdev_priv(dev);

switch (event) {
case NETDEV_REGISTER:
@@ -120,15 +163,15 @@ static int macvtap_device_event(struct notifier_block *unused,
* been registered but before register_netdevice has
* finished running.
*/
- err = tap_get_minor(vlan);
+ err = tap_get_minor(&vlantap->tap);
if (err)
return notifier_from_errno(err);

- devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
+ devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
classdev = device_create(&macvtap_class, &dev->dev, devt,
dev, tap_name);
if (IS_ERR(classdev)) {
- tap_free_minor(vlan);
+ tap_free_minor(&vlantap->tap);
return notifier_from_errno(PTR_ERR(classdev));
}
err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
@@ -138,15 +181,15 @@ static int macvtap_device_event(struct notifier_block *unused,
break;
case NETDEV_UNREGISTER:
/* vlan->minor == 0 if NETDEV_REGISTER above failed */
- if (vlan->minor == 0)
+ if (vlantap->tap.minor == 0)
break;
sysfs_remove_link(&dev->dev.kobj, tap_name);
- devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
+ devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
device_destroy(&macvtap_class, devt);
- tap_free_minor(vlan);
+ tap_free_minor(&vlantap->tap);
break;
case NETDEV_CHANGE_TX_QUEUE_LEN:
- if (tap_queue_resize(vlan))
+ if (tap_queue_resize(&vlantap->tap))
return NOTIFY_BAD;
break;
}
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 04ba978..7d3e8b1 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -1,5 +1,5 @@
#include <linux/etherdevice.h>
-#include <linux/if_macvlan.h>
+#include <linux/if_tap.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
@@ -23,30 +23,6 @@
#include <linux/virtio_net.h>
#include <linux/skb_array.h>

-/*
- * A tap queue is the central object of this driver, it connects
- * an open character device to a macvlan interface. There can be
- * multiple queues on one interface, which map back to queues
- * implemented in hardware on the underlying device.
- *
- * tap_proto is used to allocate queues through the sock allocation
- * mechanism.
- *
- */
-struct tap_queue {
- struct sock sk;
- struct socket sock;
- struct socket_wq wq;
- int vnet_hdr_sz;
- struct macvlan_dev __rcu *vlan;
- struct file *file;
- unsigned int flags;
- u16 queue_index;
- bool enabled;
- struct list_head next;
- struct skb_array skb_array;
-};
-
#define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)

#define TAP_VNET_LE 0x80000000
@@ -137,7 +113,7 @@ static const struct proto_ops tap_socket_ops;
#define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST)

-static struct macvlan_dev *tap_get_vlan_rcu(const struct net_device *dev)
+static struct tap_dev *tap_dev_get_rcu(const struct net_device *dev)
{
return rcu_dereference(dev->rx_handler_data);
}
@@ -159,10 +135,9 @@ static struct macvlan_dev *tap_get_vlan_rcu(const struct net_device *dev)
* when both our references and any pending SKBs are gone.
*/

-static int tap_enable_queue(struct net_device *dev, struct file *file,
+static int tap_enable_queue(struct tap_dev *tap, struct file *file,
struct tap_queue *q)
{
- struct macvlan_dev *vlan = netdev_priv(dev);
int err = -EINVAL;

ASSERT_RTNL();
@@ -171,62 +146,60 @@ static int tap_enable_queue(struct net_device *dev, struct file *file,
goto out;

err = 0;
- rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
- q->queue_index = vlan->numvtaps;
+ rcu_assign_pointer(tap->taps[tap->numvtaps], q);
+ q->queue_index = tap->numvtaps;
q->enabled = true;

- vlan->numvtaps++;
+ tap->numvtaps++;
out:
return err;
}

/* Requires RTNL */
-static int tap_set_queue(struct net_device *dev, struct file *file,
+static int tap_set_queue(struct tap_dev *tap, struct file *file,
struct tap_queue *q)
{
- struct macvlan_dev *vlan = netdev_priv(dev);
-
- if (vlan->numqueues == MAX_TAP_QUEUES)
+ if (tap->numqueues == MAX_TAP_QUEUES)
return -EBUSY;

- rcu_assign_pointer(q->vlan, vlan);
- rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
+ rcu_assign_pointer(q->tap, tap);
+ rcu_assign_pointer(tap->taps[tap->numvtaps], q);
sock_hold(&q->sk);

q->file = file;
- q->queue_index = vlan->numvtaps;
+ q->queue_index = tap->numvtaps;
q->enabled = true;
file->private_data = q;
- list_add_tail(&q->next, &vlan->queue_list);
+ list_add_tail(&q->next, &tap->queue_list);

- vlan->numvtaps++;
- vlan->numqueues++;
+ tap->numvtaps++;
+ tap->numqueues++;

return 0;
}

static int tap_disable_queue(struct tap_queue *q)
{
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
struct tap_queue *nq;

ASSERT_RTNL();
if (!q->enabled)
return -EINVAL;

- vlan = rtnl_dereference(q->vlan);
+ tap = rtnl_dereference(q->tap);

- if (vlan) {
+ if (tap) {
int index = q->queue_index;
- BUG_ON(index >= vlan->numvtaps);
- nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
+ BUG_ON(index >= tap->numvtaps);
+ nq = rtnl_dereference(tap->taps[tap->numvtaps - 1]);
nq->queue_index = index;

- rcu_assign_pointer(vlan->taps[index], nq);
- RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
+ rcu_assign_pointer(tap->taps[index], nq);
+ RCU_INIT_POINTER(tap->taps[tap->numvtaps - 1], NULL);
q->enabled = false;

- vlan->numvtaps--;
+ tap->numvtaps--;
}

return 0;
@@ -242,17 +215,17 @@ static int tap_disable_queue(struct tap_queue *q)
*/
static void tap_put_queue(struct tap_queue *q)
{
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;

rtnl_lock();
- vlan = rtnl_dereference(q->vlan);
+ tap = rtnl_dereference(q->tap);

- if (vlan) {
+ if (tap) {
if (q->enabled)
BUG_ON(tap_disable_queue(q));

- vlan->numqueues--;
- RCU_INIT_POINTER(q->vlan, NULL);
+ tap->numqueues--;
+ RCU_INIT_POINTER(q->tap, NULL);
sock_put(&q->sk);
list_del_init(&q->next);
}
@@ -270,17 +243,16 @@ static void tap_put_queue(struct tap_queue *q)
* Cache vlan->numvtaps since it can become zero during the execution
* of this function.
*/
-static struct tap_queue *tap_get_queue(struct net_device *dev,
+static struct tap_queue *tap_get_queue(struct tap_dev *tap,
struct sk_buff *skb)
{
- struct macvlan_dev *vlan = netdev_priv(dev);
- struct tap_queue *tap = NULL;
+ struct tap_queue *queue = NULL;
/* Access to taps array is protected by rcu, but access to numvtaps
* isn't. Below we use it to lookup a queue, but treat it as a hint
* and validate that the result isn't NULL - in case we are
* racing against queue removal.
*/
- int numvtaps = ACCESS_ONCE(vlan->numvtaps);
+ int numvtaps = ACCESS_ONCE(tap->numvtaps);
__u32 rxq;

if (!numvtaps)
@@ -292,7 +264,7 @@ static struct tap_queue *tap_get_queue(struct net_device *dev,
/* Check if we can use flow to select a queue */
rxq = skb_get_hash(skb);
if (rxq) {
- tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
+ queue = rcu_dereference(tap->taps[rxq % numvtaps]);
goto out;
}

@@ -302,14 +274,14 @@ static struct tap_queue *tap_get_queue(struct net_device *dev,
while (unlikely(rxq >= numvtaps))
rxq -= numvtaps;

- tap = rcu_dereference(vlan->taps[rxq]);
+ queue = rcu_dereference(tap->taps[rxq]);
goto out;
}

single:
- tap = rcu_dereference(vlan->taps[0]);
+ queue = rcu_dereference(tap->taps[0]);
out:
- return tap;
+ return queue;
}

/*
@@ -317,39 +289,38 @@ static struct tap_queue *tap_get_queue(struct net_device *dev,
* that it holds on all queues and safely set the pointer
* from the queues to NULL.
*/
-void tap_del_queues(struct net_device *dev)
+void tap_del_queues(struct tap_dev *tap)
{
- struct macvlan_dev *vlan = netdev_priv(dev);
struct tap_queue *q, *tmp;

ASSERT_RTNL();
- list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
+ list_for_each_entry_safe(q, tmp, &tap->queue_list, next) {
list_del_init(&q->next);
- RCU_INIT_POINTER(q->vlan, NULL);
+ RCU_INIT_POINTER(q->tap, NULL);
if (q->enabled)
- vlan->numvtaps--;
- vlan->numqueues--;
+ tap->numvtaps--;
+ tap->numqueues--;
sock_put(&q->sk);
}
- BUG_ON(vlan->numvtaps);
- BUG_ON(vlan->numqueues);
+ BUG_ON(tap->numvtaps);
+ BUG_ON(tap->numqueues);
/* guarantee that any future tap_set_queue will fail */
- vlan->numvtaps = MAX_TAP_QUEUES;
+ tap->numvtaps = MAX_TAP_QUEUES;
}

rx_handler_result_t tap_handle_frame(struct sk_buff **pskb)
{
struct sk_buff *skb = *pskb;
struct net_device *dev = skb->dev;
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
struct tap_queue *q;
netdev_features_t features = TAP_FEATURES;

- vlan = tap_get_vlan_rcu(dev);
- if (!vlan)
+ tap = tap_dev_get_rcu(dev);
+ if (!tap)
return RX_HANDLER_PASS;

- q = tap_get_queue(dev, skb);
+ q = tap_get_queue(tap, skb);
if (!q)
return RX_HANDLER_PASS;

@@ -363,7 +334,7 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb)
* enabled.
*/
if (q->flags & IFF_VNET_HDR)
- features |= vlan->tap_features;
+ features |= tap->tap_features;
if (netif_needs_gso(skb, features)) {
struct sk_buff *segs = __skb_gso_segment(skb, features, false);

@@ -408,50 +379,51 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb)

drop:
/* Count errors/drops only here, thus don't care about args. */
- macvlan_count_rx(vlan, 0, 0, 0);
+ if (tap->count_rx_dropped)
+ tap->count_rx_dropped(tap);
kfree_skb(skb);
return RX_HANDLER_CONSUMED;
}

-int tap_get_minor(struct macvlan_dev *vlan)
+int tap_get_minor(struct tap_dev *tap)
{
int retval = -ENOMEM;

mutex_lock(&macvtap_major.minor_lock);
- retval = idr_alloc(&macvtap_major.minor_idr, vlan, 1, TAP_NUM_DEVS, GFP_KERNEL);
+ retval = idr_alloc(&macvtap_major.minor_idr, tap, 1, TAP_NUM_DEVS, GFP_KERNEL);
if (retval >= 0) {
- vlan->minor = retval;
+ tap->minor = retval;
} else if (retval == -ENOSPC) {
- netdev_err(vlan->dev, "Too many tap devices\n");
+ netdev_err(tap->dev, "Too many tap devices\n");
retval = -EINVAL;
}
mutex_unlock(&macvtap_major.minor_lock);
return retval < 0 ? retval : 0;
}

-void tap_free_minor(struct macvlan_dev *vlan)
+void tap_free_minor(struct tap_dev *tap)
{
mutex_lock(&macvtap_major.minor_lock);
- if (vlan->minor) {
- idr_remove(&macvtap_major.minor_idr, vlan->minor);
- vlan->minor = 0;
+ if (tap->minor) {
+ idr_remove(&macvtap_major.minor_idr, tap->minor);
+ tap->minor = 0;
}
mutex_unlock(&macvtap_major.minor_lock);
}

-static struct net_device *dev_get_by_tap_minor(int minor)
+static struct tap_dev *dev_get_by_tap_minor(int minor)
{
struct net_device *dev = NULL;
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;

mutex_lock(&macvtap_major.minor_lock);
- vlan = idr_find(&macvtap_major.minor_idr, minor);
- if (vlan) {
- dev = vlan->dev;
+ tap = idr_find(&macvtap_major.minor_idr, minor);
+ if (tap) {
+ dev = tap->dev;
dev_hold(dev);
}
mutex_unlock(&macvtap_major.minor_lock);
- return dev;
+ return tap;
}

static void tap_sock_write_space(struct sock *sk)
@@ -477,13 +449,13 @@ static void tap_sock_destruct(struct sock *sk)
static int tap_open(struct inode *inode, struct file *file)
{
struct net *net = current->nsproxy->net_ns;
- struct net_device *dev;
+ struct tap_dev *tap;
struct tap_queue *q;
int err = -ENODEV;

rtnl_lock();
- dev = dev_get_by_tap_minor(iminor(inode));
- if (!dev)
+ tap = dev_get_by_tap_minor(iminor(inode));
+ if (!tap)
goto err;

err = -ENOMEM;
@@ -511,18 +483,18 @@ static int tap_open(struct inode *inode, struct file *file)
* The macvlan supports zerocopy iff the lower device supports zero
* copy so we don't have to look at the lower device directly.
*/
- if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
+ if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG))
sock_set_flag(&q->sk, SOCK_ZEROCOPY);

err = -ENOMEM;
- if (skb_array_init(&q->skb_array, dev->tx_queue_len, GFP_KERNEL))
+ if (skb_array_init(&q->skb_array, tap->dev->tx_queue_len, GFP_KERNEL))
goto err_array;

- err = tap_set_queue(dev, file, q);
+ err = tap_set_queue(tap, file, q);
if (err)
goto err_queue;

- dev_put(dev);
+ dev_put(tap->dev);

rtnl_unlock();
return err;
@@ -532,8 +504,8 @@ static int tap_open(struct inode *inode, struct file *file)
err_array:
sock_put(&q->sk);
err:
- if (dev)
- dev_put(dev);
+ if (tap)
+ dev_put(tap->dev);

rtnl_unlock();
return err;
@@ -601,7 +573,7 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
{
int good_linear = SKB_MAX_HEAD(TAP_RESERVE);
struct sk_buff *skb;
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
unsigned long total_len = iov_iter_count(from);
unsigned long len = total_len;
int err;
@@ -698,7 +670,7 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
skb_set_network_header(skb, depth);

rcu_read_lock();
- vlan = rcu_dereference(q->vlan);
+ tap = rcu_dereference(q->tap);
/* copy skb_ubuf_info for callback when skb has no error */
if (zerocopy) {
skb_shinfo(skb)->destructor_arg = m->msg_control;
@@ -709,8 +681,8 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,
uarg->callback(uarg, false);
}

- if (vlan) {
- skb->dev = vlan->dev;
+ if (tap) {
+ skb->dev = tap->dev;
dev_queue_xmit(skb);
} else {
kfree_skb(skb);
@@ -724,9 +696,9 @@ static ssize_t tap_get_user(struct tap_queue *q, struct msghdr *m,

err:
rcu_read_lock();
- vlan = rcu_dereference(q->vlan);
- if (vlan)
- this_cpu_inc(vlan->pcpu_stats->tx_dropped);
+ tap = rcu_dereference(q->tap);
+ if (tap && tap->count_tx_dropped)
+ tap->count_tx_dropped(tap);
rcu_read_unlock();

return err;
@@ -853,55 +825,55 @@ static ssize_t tap_read_iter(struct kiocb *iocb, struct iov_iter *to)
return ret;
}

-static struct macvlan_dev *tap_get_vlan(struct tap_queue *q)
+static struct tap_dev *tap_get_tap_dev(struct tap_queue *q)
{
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;

ASSERT_RTNL();
- vlan = rtnl_dereference(q->vlan);
- if (vlan)
- dev_hold(vlan->dev);
+ tap = rtnl_dereference(q->tap);
+ if (tap)
+ dev_hold(tap->dev);

- return vlan;
+ return tap;
}

-static void tap_put_vlan(struct macvlan_dev *vlan)
+static void tap_put_tap_dev(struct tap_dev *tap)
{
- dev_put(vlan->dev);
+ dev_put(tap->dev);
}

static int tap_ioctl_set_queue(struct file *file, unsigned int flags)
{
struct tap_queue *q = file->private_data;
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
int ret;

- vlan = tap_get_vlan(q);
- if (!vlan)
+ tap = tap_get_tap_dev(q);
+ if (!tap)
return -EINVAL;

if (flags & IFF_ATTACH_QUEUE)
- ret = tap_enable_queue(vlan->dev, file, q);
+ ret = tap_enable_queue(tap, file, q);
else if (flags & IFF_DETACH_QUEUE)
ret = tap_disable_queue(q);
else
ret = -EINVAL;

- tap_put_vlan(vlan);
+ tap_put_tap_dev(tap);
return ret;
}

static int set_offload(struct tap_queue *q, unsigned long arg)
{
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
netdev_features_t features;
netdev_features_t feature_mask = 0;

- vlan = rtnl_dereference(q->vlan);
- if (!vlan)
+ tap = rtnl_dereference(q->tap);
+ if (!tap)
return -ENOLINK;

- features = vlan->dev->features;
+ features = tap->dev->features;

if (arg & TUN_F_CSUM) {
feature_mask = NETIF_F_HW_CSUM;
@@ -935,9 +907,9 @@ static int set_offload(struct tap_queue *q, unsigned long arg)
/* tap_features are the same as features on tun/tap and
* reflect user expectations.
*/
- vlan->tap_features = feature_mask;
- vlan->set_features = features;
- netdev_update_features(vlan->dev);
+ tap->tap_features = feature_mask;
+ if (tap->update_features)
+ tap->update_features(tap, features);

return 0;
}
@@ -949,7 +921,7 @@ static long tap_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct tap_queue *q = file->private_data;
- struct macvlan_dev *vlan;
+ struct tap_dev *tap;
void __user *argp = (void __user *)arg;
struct ifreq __user *ifr = argp;
unsigned int __user *up = argp;
@@ -975,18 +947,18 @@ static long tap_ioctl(struct file *file, unsigned int cmd,

case TUNGETIFF:
rtnl_lock();
- vlan = tap_get_vlan(q);
- if (!vlan) {
+ tap = tap_get_tap_dev(q);
+ if (!tap) {
rtnl_unlock();
return -ENOLINK;
}

ret = 0;
u = q->flags;
- if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
+ if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) ||
put_user(u, &ifr->ifr_flags))
ret = -EFAULT;
- tap_put_vlan(vlan);
+ tap_put_tap_dev(tap);
rtnl_unlock();
return ret;

@@ -1059,18 +1031,18 @@ static long tap_ioctl(struct file *file, unsigned int cmd,

case SIOCGIFHWADDR:
rtnl_lock();
- vlan = tap_get_vlan(q);
- if (!vlan) {
+ tap = tap_get_tap_dev(q);
+ if (!tap) {
rtnl_unlock();
return -ENOLINK;
}
ret = 0;
- u = vlan->dev->type;
- if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
- copy_to_user(&ifr->ifr_hwaddr.sa_data, vlan->dev->dev_addr, ETH_ALEN) ||
+ u = tap->dev->type;
+ if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) ||
+ copy_to_user(&ifr->ifr_hwaddr.sa_data, tap->dev->dev_addr, ETH_ALEN) ||
put_user(u, &ifr->ifr_hwaddr.sa_family))
ret = -EFAULT;
- tap_put_vlan(vlan);
+ tap_put_tap_dev(tap);
rtnl_unlock();
return ret;

@@ -1078,13 +1050,13 @@ static long tap_ioctl(struct file *file, unsigned int cmd,
if (copy_from_user(&sa, &ifr->ifr_hwaddr, sizeof(sa)))
return -EFAULT;
rtnl_lock();
- vlan = tap_get_vlan(q);
- if (!vlan) {
+ tap = tap_get_tap_dev(q);
+ if (!tap) {
rtnl_unlock();
return -ENOLINK;
}
- ret = dev_set_mac_address(vlan->dev, &sa);
- tap_put_vlan(vlan);
+ ret = dev_set_mac_address(tap->dev, &sa);
+ tap_put_tap_dev(tap);
rtnl_unlock();
return ret;

@@ -1167,19 +1139,19 @@ struct socket *tap_get_socket(struct file *file)
}
EXPORT_SYMBOL_GPL(tap_get_socket);

-int tap_queue_resize(struct macvlan_dev *vlan)
+int tap_queue_resize(struct tap_dev *tap)
{
- struct net_device *dev = vlan->dev;
+ struct net_device *dev = tap->dev;
struct tap_queue *q;
struct skb_array **arrays;
- int n = vlan->numqueues;
+ int n = tap->numqueues;
int ret, i = 0;

arrays = kmalloc(sizeof *arrays * n, GFP_KERNEL);
if (!arrays)
return -ENOMEM;

- list_for_each_entry(q, &vlan->queue_list, next)
+ list_for_each_entry(q, &tap->queue_list, next)
arrays[i++] = &q->skb_array;

ret = skb_array_resize_multiple(arrays, n,
diff --git a/include/linux/if_tap.h b/include/linux/if_tap.h
index a2dfd90..75031e5 100644
--- a/include/linux/if_tap.h
+++ b/include/linux/if_tap.h
@@ -14,11 +14,60 @@ static inline struct socket *tap_get_socket(struct file *f)
}
#endif /* CONFIG_MACVTAP */

+#include <net/sock.h>
+#include <linux/skb_array.h>
+
+#define MAX_TAP_QUEUES 256
+
+struct tap_queue;
+
+struct tap_dev {
+ struct net_device *dev;
+ u16 flags;
+ /* This array tracks active taps. */
+ struct tap_queue __rcu *taps[MAX_TAP_QUEUES];
+ /* This list tracks all taps (both enabled and disabled) */
+ struct list_head queue_list;
+ int numvtaps;
+ int numqueues;
+ netdev_features_t tap_features;
+ int minor;
+
+ void (*update_features)(struct tap_dev *tap, netdev_features_t features);
+ void (*count_tx_dropped)(struct tap_dev *tap);
+ void (*count_rx_dropped)(struct tap_dev *tap);
+};
+
+/*
+ * A tap queue is the central object of tap module, it connects
+ * an open character device to virtual interface. There can be
+ * multiple queues on one interface, which map back to queues
+ * implemented in hardware on the underlying device.
+ *
+ * tap_proto is used to allocate queues through the sock allocation
+ * mechanism.
+ *
+ */
+
+struct tap_queue {
+ struct sock sk;
+ struct socket sock;
+ struct socket_wq wq;
+ int vnet_hdr_sz;
+ struct tap_dev __rcu *tap;
+ struct file *file;
+ unsigned int flags;
+ u16 queue_index;
+ bool enabled;
+ struct list_head next;
+ struct skb_array skb_array;
+};
+
rx_handler_result_t tap_handle_frame(struct sk_buff **pskb);
-void tap_del_queues(struct net_device *dev);
-int tap_get_minor(struct macvlan_dev *vlan);
-void tap_free_minor(struct macvlan_dev *vlan);
-int tap_queue_resize(struct macvlan_dev *vlan);
+void tap_del_queues(struct tap_dev *tap);
+int tap_get_minor(struct tap_dev *tap);
+void tap_free_minor(struct tap_dev *tap);
+int tap_queue_resize(struct tap_dev *tap);
int tap_create_cdev(struct cdev *tap_cdev,
dev_t *tap_major, const char *device_name);
void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev);
--
2.7.4