};
/*
- * Minor number matches netdev->ifindex, so need a potentially
- * large value. This also makes it possible to split the
- * tap functionality out again in the future by offering it
- * from other drivers besides macvtap. As long as every device
- * only has one tap, the interface numbers assure that the
- * device nodes are unique.
+ * Variables for dealing with macvtaps device numbers.
*/
static dev_t macvtap_major;
-#define MACVTAP_NUM_DEVS 65536
+#define MACVTAP_NUM_DEVS (1U << MINORBITS)
+static DEFINE_MUTEX(minor_lock);
+static DEFINE_IDR(minor_idr);
+
#define GOODCOPY_LEN 128
static struct class *macvtap_class;
static struct cdev macvtap_cdev;
}
}
BUG_ON(vlan->numvtaps != 0);
+ /* guarantee that any future macvtap_set_queue will fail */
+ vlan->numvtaps = MAX_MACVTAP_QUEUES;
spin_unlock(&macvtap_lock);
synchronize_rcu();
return macvtap_forward(skb->dev, skb);
}
-static int macvtap_newlink(struct net *src_net,
- struct net_device *dev,
- struct nlattr *tb[],
- struct nlattr *data[])
+static int macvtap_get_minor(struct macvlan_dev *vlan)
{
- struct device *classdev;
- dev_t devt;
- int err;
+ int retval = -ENOMEM;
+ int id;
+
+ mutex_lock(&minor_lock);
+ if (idr_pre_get(&minor_idr, GFP_KERNEL) == 0)
+ goto exit;
+
+ retval = idr_get_new_above(&minor_idr, vlan, 1, &id);
+ if (retval < 0) {
+ if (retval == -EAGAIN)
+ retval = -ENOMEM;
+ goto exit;
+ }
+ if (id < MACVTAP_NUM_DEVS) {
+ vlan->minor = id;
+ } else {
+ printk(KERN_ERR "too many macvtap devices\n");
+ retval = -EINVAL;
+ idr_remove(&minor_idr, id);
+ }
+exit:
+ mutex_unlock(&minor_lock);
+ return retval;
+}
- err = macvlan_common_newlink(src_net, dev, tb, data,
- macvtap_receive, macvtap_forward);
- if (err)
- goto out;
+static void macvtap_free_minor(struct macvlan_dev *vlan)
+{
+ mutex_lock(&minor_lock);
+ if (vlan->minor) {
+ idr_remove(&minor_idr, vlan->minor);
+ vlan->minor = 0;
+ }
+ mutex_unlock(&minor_lock);
+}
- devt = MKDEV(MAJOR(macvtap_major), dev->ifindex);
+static struct net_device *dev_get_by_macvtap_minor(int minor)
+{
+ struct net_device *dev = NULL;
+ struct macvlan_dev *vlan;
- classdev = device_create(macvtap_class, &dev->dev, devt,
- dev, "tap%d", dev->ifindex);
- if (IS_ERR(classdev)) {
- err = PTR_ERR(classdev);
- macvtap_del_queues(dev);
+ mutex_lock(&minor_lock);
+ vlan = idr_find(&minor_idr, minor);
+ if (vlan) {
+ dev = vlan->dev;
+ dev_hold(dev);
}
+ mutex_unlock(&minor_lock);
+ return dev;
+}
-out:
- return err;
+static int macvtap_newlink(struct net *src_net,
+ struct net_device *dev,
+ struct nlattr *tb[],
+ struct nlattr *data[])
+{
+ /* Don't put anything that may fail after macvlan_common_newlink
+ * because we can't undo what it does.
+ */
+ return macvlan_common_newlink(src_net, dev, tb, data,
+ macvtap_receive, macvtap_forward);
}
static void macvtap_dellink(struct net_device *dev,
struct list_head *head)
{
- device_destroy(macvtap_class,
- MKDEV(MAJOR(macvtap_major), dev->ifindex));
-
macvtap_del_queues(dev);
macvlan_dellink(dev, head);
}
wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
}
+static void macvtap_sock_destruct(struct sock *sk)
+{
+ skb_queue_purge(&sk->sk_receive_queue);
+}
+
static int macvtap_open(struct inode *inode, struct file *file)
{
struct net *net = current->nsproxy->net_ns;
- struct net_device *dev = dev_get_by_index(net, iminor(inode));
- struct macvlan_dev *vlan = netdev_priv(dev);
+ struct net_device *dev = dev_get_by_macvtap_minor(iminor(inode));
struct macvtap_queue *q;
int err;
if (!dev)
goto out;
- /* check if this is a macvtap device */
- err = -EINVAL;
- if (dev->rtnl_link_ops != &macvtap_link_ops)
- goto out;
-
err = -ENOMEM;
q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
&macvtap_proto);
q->sock.ops = &macvtap_socket_ops;
sock_init_data(&q->sock, &q->sk);
q->sk.sk_write_space = macvtap_sock_write_space;
+ q->sk.sk_destruct = macvtap_sock_destruct;
q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
/*
* so far only KVM virtio_net uses macvtap, enable zero copy between
* guest kernel and host kernel when lower device supports zerocopy
+ *
+ * The macvlan supports zerocopy iff the lower device supports zero
+ * copy so we don't have to look at the lower device directly.
*/
- if (vlan) {
- if ((vlan->lowerdev->features & NETIF_F_HIGHDMA) &&
- (vlan->lowerdev->features & NETIF_F_SG))
- sock_set_flag(&q->sk, SOCK_ZEROCOPY);
- }
+ if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
+ sock_set_flag(&q->sk, SOCK_ZEROCOPY);
err = macvtap_set_queue(dev, file, q);
if (err)
int copy = skb_headlen(skb);
int size, offset1 = 0;
int i = 0;
- skb_frag_t *f;
/* Skip over from offset */
while (count && (offset >= from->iov_len)) {
skb->truesize += len;
atomic_add(len, &skb->sk->sk_wmem_alloc);
while (len) {
- f = &skb_shinfo(skb)->frags[i];
- f->page = page[i];
- f->page_offset = base & ~PAGE_MASK;
- f->size = min_t(int, len, PAGE_SIZE - f->page_offset);
+ int off = base & ~PAGE_MASK;
+ int size = min_t(int, len, PAGE_SIZE - off);
+ __skb_fill_page_desc(skb, i, page[i], off, size);
skb_shinfo(skb)->nr_frags++;
/* increase sk_wmem_alloc */
- base += f->size;
- len -= f->size;
+ base += size;
+ len -= size;
i++;
}
offset1 = 0;
}
EXPORT_SYMBOL_GPL(macvtap_get_socket);
+static int macvtap_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct macvlan_dev *vlan;
+ struct device *classdev;
+ dev_t devt;
+ int err;
+
+ if (dev->rtnl_link_ops != &macvtap_link_ops)
+ return NOTIFY_DONE;
+
+ vlan = netdev_priv(dev);
+
+ switch (event) {
+ case NETDEV_REGISTER:
+ /* Create the device node here after the network device has
+ * been registered but before register_netdevice has
+ * finished running.
+ */
+ err = macvtap_get_minor(vlan);
+ if (err)
+ return notifier_from_errno(err);
+
+ devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
+ classdev = device_create(macvtap_class, &dev->dev, devt,
+ dev, "tap%d", dev->ifindex);
+ if (IS_ERR(classdev)) {
+ macvtap_free_minor(vlan);
+ return notifier_from_errno(PTR_ERR(classdev));
+ }
+ break;
+ case NETDEV_UNREGISTER:
+ devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
+ device_destroy(macvtap_class, devt);
+ macvtap_free_minor(vlan);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block macvtap_notifier_block __read_mostly = {
+ .notifier_call = macvtap_device_event,
+};
+
static int macvtap_init(void)
{
int err;
goto out3;
}
- err = macvlan_link_register(&macvtap_link_ops);
+ err = register_netdevice_notifier(&macvtap_notifier_block);
if (err)
goto out4;
+ err = macvlan_link_register(&macvtap_link_ops);
+ if (err)
+ goto out5;
+
return 0;
+out5:
+ unregister_netdevice_notifier(&macvtap_notifier_block);
out4:
class_unregister(macvtap_class);
out3:
static void macvtap_exit(void)
{
rtnl_link_unregister(&macvtap_link_ops);
+ unregister_netdevice_notifier(&macvtap_notifier_block);
class_unregister(macvtap_class);
cdev_del(&macvtap_cdev);
unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
git.openpandora.org / pandora-kernel.git / blobdiff