macvtap: add TUNSETQUEUE ioctl
This patch adds TUNSETQUEUE ioctl to let userspace can temporarily disable or enable a queue of macvtap. This is used to be compatible at API layer of tuntap to simplify the userspace to manage the queues. This is done through introducing a linked list to track all taps while using vlan->taps array to only track active taps. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang
David S. Miller
Родитель
376b1aabe1
Коммит
815f236d62
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@ -45,6 +45,8 @@ struct macvtap_queue {
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struct file *file;
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unsigned int flags;
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u16 queue_index;
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bool enabled;
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struct list_head next;
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};
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static struct proto macvtap_proto = {
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@ -85,14 +87,36 @@ static const struct proto_ops macvtap_socket_ops;
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*/
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static DEFINE_SPINLOCK(macvtap_lock);
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static int macvtap_set_queue(struct net_device *dev, struct file *file,
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static int macvtap_enable_queue(struct net_device *dev, struct file *file,
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struct macvtap_queue *q)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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int err = -EINVAL;
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spin_lock(&macvtap_lock);
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if (q->enabled)
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goto out;
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err = 0;
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rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
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q->queue_index = vlan->numvtaps;
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q->enabled = true;
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vlan->numvtaps++;
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out:
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spin_unlock(&macvtap_lock);
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return err;
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}
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static int macvtap_set_queue(struct net_device *dev, struct file *file,
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struct macvtap_queue *q)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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int err = -EBUSY;
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spin_lock(&macvtap_lock);
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if (vlan->numvtaps == MAX_MACVTAP_QUEUES)
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if (vlan->numqueues == MAX_MACVTAP_QUEUES)
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goto out;
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err = 0;
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@ -102,15 +126,57 @@ static int macvtap_set_queue(struct net_device *dev, struct file *file,
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q->file = file;
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q->queue_index = vlan->numvtaps;
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q->enabled = true;
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file->private_data = q;
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list_add_tail(&q->next, &vlan->queue_list);
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vlan->numvtaps++;
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vlan->numqueues++;
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out:
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spin_unlock(&macvtap_lock);
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return err;
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}
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static int __macvtap_disable_queue(struct macvtap_queue *q)
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{
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struct macvlan_dev *vlan;
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struct macvtap_queue *nq;
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vlan = rcu_dereference_protected(q->vlan,
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lockdep_is_held(&macvtap_lock));
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if (!q->enabled)
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return -EINVAL;
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if (vlan) {
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int index = q->queue_index;
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BUG_ON(index >= vlan->numvtaps);
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nq = rcu_dereference_protected(vlan->taps[vlan->numvtaps - 1],
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lockdep_is_held(&macvtap_lock));
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nq->queue_index = index;
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rcu_assign_pointer(vlan->taps[index], nq);
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RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
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q->enabled = false;
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vlan->numvtaps--;
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}
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return 0;
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}
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static int macvtap_disable_queue(struct macvtap_queue *q)
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{
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int err;
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spin_lock(&macvtap_lock);
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err = __macvtap_disable_queue(q);
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spin_unlock(&macvtap_lock);
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return err;
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}
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/*
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* The file owning the queue got closed, give up both
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* the reference that the files holds as well as the
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@ -121,25 +187,19 @@ out:
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*/
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static void macvtap_put_queue(struct macvtap_queue *q)
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{
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struct macvtap_queue *nq;
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struct macvlan_dev *vlan;
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spin_lock(&macvtap_lock);
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vlan = rcu_dereference_protected(q->vlan,
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lockdep_is_held(&macvtap_lock));
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if (vlan) {
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int index = q->queue_index;
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BUG_ON(index >= vlan->numvtaps);
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if (q->enabled)
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BUG_ON(__macvtap_disable_queue(q));
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nq = rcu_dereference_protected(vlan->taps[vlan->numvtaps - 1],
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lockdep_is_held(&macvtap_lock));
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rcu_assign_pointer(vlan->taps[index], nq);
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nq->queue_index = index;
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RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
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vlan->numqueues--;
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RCU_INIT_POINTER(q->vlan, NULL);
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sock_put(&q->sk);
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--vlan->numvtaps;
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list_del_init(&q->next);
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}
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spin_unlock(&macvtap_lock);
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@ -160,6 +220,11 @@ static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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struct macvtap_queue *tap = NULL;
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/* Access to taps array is protected by rcu, but access to numvtaps
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* isn't. Below we use it to lookup a queue, but treat it as a hint
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* and validate that the result isn't NULL - in case we are
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* racing against queue removal.
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*/
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int numvtaps = ACCESS_ONCE(vlan->numvtaps);
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__u32 rxq;
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@ -196,18 +261,22 @@ out:
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static void macvtap_del_queues(struct net_device *dev)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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struct macvtap_queue *q, *qlist[MAX_MACVTAP_QUEUES];
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struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES];
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int i, j = 0;
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spin_lock(&macvtap_lock);
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for (i = 0; i < vlan->numvtaps; i++) {
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q = rcu_dereference_protected(vlan->taps[i],
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lockdep_is_held(&macvtap_lock));
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BUG_ON(q == NULL);
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list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
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list_del_init(&q->next);
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qlist[j++] = q;
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RCU_INIT_POINTER(vlan->taps[i], NULL);
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RCU_INIT_POINTER(q->vlan, NULL);
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if (q->enabled)
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vlan->numvtaps--;
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vlan->numqueues--;
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}
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for (i = 0; i < vlan->numvtaps; i++)
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RCU_INIT_POINTER(vlan->taps[i], NULL);
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BUG_ON(vlan->numvtaps);
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BUG_ON(vlan->numqueues);
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/* guarantee that any future macvtap_set_queue will fail */
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vlan->numvtaps = MAX_MACVTAP_QUEUES;
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spin_unlock(&macvtap_lock);
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@ -298,6 +367,9 @@ static int macvtap_newlink(struct net *src_net,
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struct nlattr *tb[],
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struct nlattr *data[])
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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INIT_LIST_HEAD(&vlan->queue_list);
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/* Don't put anything that may fail after macvlan_common_newlink
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* because we can't undo what it does.
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*/
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@ -887,6 +959,25 @@ static void macvtap_put_vlan(struct macvlan_dev *vlan)
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dev_put(vlan->dev);
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}
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static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags)
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{
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struct macvtap_queue *q = file->private_data;
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struct macvlan_dev *vlan;
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int ret;
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vlan = macvtap_get_vlan(q);
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if (!vlan)
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return -EINVAL;
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if (flags & IFF_ATTACH_QUEUE)
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ret = macvtap_enable_queue(vlan->dev, file, q);
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else if (flags & IFF_DETACH_QUEUE)
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ret = macvtap_disable_queue(q);
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macvtap_put_vlan(vlan);
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return ret;
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}
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/*
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* provide compatibility with generic tun/tap interface
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*/
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@ -910,7 +1001,8 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
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return -EFAULT;
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ret = 0;
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if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
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if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
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(IFF_NO_PI | IFF_TAP))
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ret = -EINVAL;
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else
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q->flags = u;
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@ -929,6 +1021,11 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
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macvtap_put_vlan(vlan);
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return ret;
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case TUNSETQUEUE:
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if (get_user(u, &ifr->ifr_flags))
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return -EFAULT;
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return macvtap_ioctl_set_queue(file, u);
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case TUNGETFEATURES:
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if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR, up))
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return -EFAULT;
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@ -69,8 +69,12 @@ struct macvlan_dev {
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u16 flags;
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int (*receive)(struct sk_buff *skb);
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int (*forward)(struct net_device *dev, struct sk_buff *skb);
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/* This array tracks active taps. */
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struct macvtap_queue *taps[MAX_MACVTAP_QUEUES];
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/* This list tracks all taps (both enabled and disabled) */
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struct list_head queue_list;
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int numvtaps;
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int numqueues;
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int minor;
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};
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