linux/drivers/net/macvtap.c
Herbert Xu 8a35747a5d macvtap: Limit packet queue length
Mark Wagner reported OOM symptoms when sending UDP traffic over
a macvtap link to a kvm receiver.

This appears to be caused by the fact that macvtap packet queues
are unlimited in length.  This means that if the receiver can't
keep up with the rate of flow, then we will hit OOM. Of course
it gets worse if the OOM killer then decides to kill the receiver.

This patch imposes a cap on the packet queue length, in the same
way as the tuntap driver, using the device TX queue length.

Please note that macvtap currently has no way of giving congestion
notification, that means the software device TX queue cannot be
used and packets will always be dropped once the macvtap driver
queue fills up.

This shouldn't be a great problem for the scenario where macvtap
is used to feed a kvm receiver, as the traffic is most likely
external in origin so congestion notification can't be applied
anyway.

Of course, if anybody decides to complain about guest-to-guest
UDP packet loss down the track, then we may have to revisit this.

Incidentally, this patch also fixes a real memory leak when
macvtap_get_queue fails.

Chris Wright noticed that for this patch to work, we need a
non-zero TX queue length.  This patch includes his work to change
the default macvtap TX queue length to 500.

Reported-by: Mark Wagner <mwagner@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-22 13:08:56 -07:00

842 lines
20 KiB
C

#include <linux/etherdevice.h>
#include <linux/if_macvlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
#include <linux/compat.h>
#include <linux/if_tun.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/cache.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <net/net_namespace.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <linux/virtio_net.h>
/*
* A macvtap 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.
*
* macvtap_proto is used to allocate queues through the sock allocation
* mechanism.
*
* TODO: multiqueue support is currently not implemented, even though
* macvtap is basically prepared for that. We will need to add this
* here as well as in virtio-net and qemu to get line rate on 10gbit
* adapters from a guest.
*/
struct macvtap_queue {
struct sock sk;
struct socket sock;
struct socket_wq wq;
int vnet_hdr_sz;
struct macvlan_dev *vlan;
struct file *file;
unsigned int flags;
};
static struct proto macvtap_proto = {
.name = "macvtap",
.owner = THIS_MODULE,
.obj_size = sizeof (struct macvtap_queue),
};
/*
* 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.
*/
static unsigned int macvtap_major;
#define MACVTAP_NUM_DEVS 65536
static struct class *macvtap_class;
static struct cdev macvtap_cdev;
static const struct proto_ops macvtap_socket_ops;
/*
* RCU usage:
* The macvtap_queue and the macvlan_dev are loosely coupled, the
* pointers from one to the other can only be read while rcu_read_lock
* or macvtap_lock is held.
*
* Both the file and the macvlan_dev hold a reference on the macvtap_queue
* through sock_hold(&q->sk). When the macvlan_dev goes away first,
* q->vlan becomes inaccessible. When the files gets closed,
* macvtap_get_queue() fails.
*
* There may still be references to the struct sock inside of the
* queue from outbound SKBs, but these never reference back to the
* file or the dev. The data structure is freed through __sk_free
* when both our references and any pending SKBs are gone.
*/
static DEFINE_SPINLOCK(macvtap_lock);
/*
* Choose the next free queue, for now there is only one
*/
static int macvtap_set_queue(struct net_device *dev, struct file *file,
struct macvtap_queue *q)
{
struct macvlan_dev *vlan = netdev_priv(dev);
int err = -EBUSY;
spin_lock(&macvtap_lock);
if (rcu_dereference(vlan->tap))
goto out;
err = 0;
rcu_assign_pointer(q->vlan, vlan);
rcu_assign_pointer(vlan->tap, q);
sock_hold(&q->sk);
q->file = file;
file->private_data = q;
out:
spin_unlock(&macvtap_lock);
return err;
}
/*
* The file owning the queue got closed, give up both
* the reference that the files holds as well as the
* one from the macvlan_dev if that still exists.
*
* Using the spinlock makes sure that we don't get
* to the queue again after destroying it.
*/
static void macvtap_put_queue(struct macvtap_queue *q)
{
struct macvlan_dev *vlan;
spin_lock(&macvtap_lock);
vlan = rcu_dereference(q->vlan);
if (vlan) {
rcu_assign_pointer(vlan->tap, NULL);
rcu_assign_pointer(q->vlan, NULL);
sock_put(&q->sk);
}
spin_unlock(&macvtap_lock);
synchronize_rcu();
sock_put(&q->sk);
}
/*
* Since we only support one queue, just dereference the pointer.
*/
static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
struct sk_buff *skb)
{
struct macvlan_dev *vlan = netdev_priv(dev);
return rcu_dereference(vlan->tap);
}
/*
* The net_device is going away, give up the reference
* that it holds on the queue (all the queues one day)
* and safely set the pointer from the queues to NULL.
*/
static void macvtap_del_queues(struct net_device *dev)
{
struct macvlan_dev *vlan = netdev_priv(dev);
struct macvtap_queue *q;
spin_lock(&macvtap_lock);
q = rcu_dereference(vlan->tap);
if (!q) {
spin_unlock(&macvtap_lock);
return;
}
rcu_assign_pointer(vlan->tap, NULL);
rcu_assign_pointer(q->vlan, NULL);
spin_unlock(&macvtap_lock);
synchronize_rcu();
sock_put(&q->sk);
}
/*
* Forward happens for data that gets sent from one macvlan
* endpoint to another one in bridge mode. We just take
* the skb and put it into the receive queue.
*/
static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
{
struct macvtap_queue *q = macvtap_get_queue(dev, skb);
if (!q)
goto drop;
if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len)
goto drop;
skb_queue_tail(&q->sk.sk_receive_queue, skb);
wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
return NET_RX_SUCCESS;
drop:
kfree_skb(skb);
return NET_RX_DROP;
}
/*
* Receive is for data from the external interface (lowerdev),
* in case of macvtap, we can treat that the same way as
* forward, which macvlan cannot.
*/
static int macvtap_receive(struct sk_buff *skb)
{
skb_push(skb, ETH_HLEN);
return macvtap_forward(skb->dev, skb);
}
static int macvtap_newlink(struct net *src_net,
struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[])
{
struct device *classdev;
dev_t devt;
int err;
err = macvlan_common_newlink(src_net, dev, tb, data,
macvtap_receive, macvtap_forward);
if (err)
goto out;
devt = MKDEV(MAJOR(macvtap_major), dev->ifindex);
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);
}
out:
return err;
}
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);
}
static void macvtap_setup(struct net_device *dev)
{
macvlan_common_setup(dev);
dev->tx_queue_len = TUN_READQ_SIZE;
}
static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
.kind = "macvtap",
.setup = macvtap_setup,
.newlink = macvtap_newlink,
.dellink = macvtap_dellink,
};
static void macvtap_sock_write_space(struct sock *sk)
{
wait_queue_head_t *wqueue;
if (!sock_writeable(sk) ||
!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
return;
wqueue = sk_sleep(sk);
if (wqueue && waitqueue_active(wqueue))
wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
}
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 macvtap_queue *q;
int err;
err = -ENODEV;
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);
if (!q)
goto out;
q->sock.wq = &q->wq;
init_waitqueue_head(&q->wq.wait);
q->sock.type = SOCK_RAW;
q->sock.state = SS_CONNECTED;
q->sock.file = file;
q->sock.ops = &macvtap_socket_ops;
sock_init_data(&q->sock, &q->sk);
q->sk.sk_write_space = macvtap_sock_write_space;
q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
err = macvtap_set_queue(dev, file, q);
if (err)
sock_put(&q->sk);
out:
if (dev)
dev_put(dev);
return err;
}
static int macvtap_release(struct inode *inode, struct file *file)
{
struct macvtap_queue *q = file->private_data;
macvtap_put_queue(q);
return 0;
}
static unsigned int macvtap_poll(struct file *file, poll_table * wait)
{
struct macvtap_queue *q = file->private_data;
unsigned int mask = POLLERR;
if (!q)
goto out;
mask = 0;
poll_wait(file, &q->wq.wait, wait);
if (!skb_queue_empty(&q->sk.sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
if (sock_writeable(&q->sk) ||
(!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
sock_writeable(&q->sk)))
mask |= POLLOUT | POLLWRNORM;
out:
return mask;
}
static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
size_t len, size_t linear,
int noblock, int *err)
{
struct sk_buff *skb;
/* Under a page? Don't bother with paged skb. */
if (prepad + len < PAGE_SIZE || !linear)
linear = len;
skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
err);
if (!skb)
return NULL;
skb_reserve(skb, prepad);
skb_put(skb, linear);
skb->data_len = len - linear;
skb->len += len - linear;
return skb;
}
/*
* macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
* be shared with the tun/tap driver.
*/
static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
struct virtio_net_hdr *vnet_hdr)
{
unsigned short gso_type = 0;
if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
case VIRTIO_NET_HDR_GSO_TCPV4:
gso_type = SKB_GSO_TCPV4;
break;
case VIRTIO_NET_HDR_GSO_TCPV6:
gso_type = SKB_GSO_TCPV6;
break;
case VIRTIO_NET_HDR_GSO_UDP:
gso_type = SKB_GSO_UDP;
break;
default:
return -EINVAL;
}
if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
gso_type |= SKB_GSO_TCP_ECN;
if (vnet_hdr->gso_size == 0)
return -EINVAL;
}
if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
vnet_hdr->csum_offset))
return -EINVAL;
}
if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
skb_shinfo(skb)->gso_type = gso_type;
/* Header must be checked, and gso_segs computed. */
skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
skb_shinfo(skb)->gso_segs = 0;
}
return 0;
}
static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
struct virtio_net_hdr *vnet_hdr)
{
memset(vnet_hdr, 0, sizeof(*vnet_hdr));
if (skb_is_gso(skb)) {
struct skb_shared_info *sinfo = skb_shinfo(skb);
/* This is a hint as to how much should be linear. */
vnet_hdr->hdr_len = skb_headlen(skb);
vnet_hdr->gso_size = sinfo->gso_size;
if (sinfo->gso_type & SKB_GSO_TCPV4)
vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (sinfo->gso_type & SKB_GSO_TCPV6)
vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
else if (sinfo->gso_type & SKB_GSO_UDP)
vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
else
BUG();
if (sinfo->gso_type & SKB_GSO_TCP_ECN)
vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
} else
vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
vnet_hdr->csum_start = skb->csum_start -
skb_headroom(skb);
vnet_hdr->csum_offset = skb->csum_offset;
} /* else everything is zero */
return 0;
}
/* Get packet from user space buffer */
static ssize_t macvtap_get_user(struct macvtap_queue *q,
const struct iovec *iv, size_t count,
int noblock)
{
struct sk_buff *skb;
struct macvlan_dev *vlan;
size_t len = count;
int err;
struct virtio_net_hdr vnet_hdr = { 0 };
int vnet_hdr_len = 0;
if (q->flags & IFF_VNET_HDR) {
vnet_hdr_len = q->vnet_hdr_sz;
err = -EINVAL;
if ((len -= vnet_hdr_len) < 0)
goto err;
err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
sizeof(vnet_hdr));
if (err < 0)
goto err;
if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
vnet_hdr.hdr_len)
vnet_hdr.hdr_len = vnet_hdr.csum_start +
vnet_hdr.csum_offset + 2;
err = -EINVAL;
if (vnet_hdr.hdr_len > len)
goto err;
}
err = -EINVAL;
if (unlikely(len < ETH_HLEN))
goto err;
skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len,
noblock, &err);
if (!skb)
goto err;
err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len);
if (err)
goto err_kfree;
skb_set_network_header(skb, ETH_HLEN);
skb_reset_mac_header(skb);
skb->protocol = eth_hdr(skb)->h_proto;
if (vnet_hdr_len) {
err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
if (err)
goto err_kfree;
}
rcu_read_lock_bh();
vlan = rcu_dereference(q->vlan);
if (vlan)
macvlan_start_xmit(skb, vlan->dev);
else
kfree_skb(skb);
rcu_read_unlock_bh();
return count;
err_kfree:
kfree_skb(skb);
err:
rcu_read_lock_bh();
vlan = rcu_dereference(q->vlan);
if (vlan)
netdev_get_tx_queue(vlan->dev, 0)->tx_dropped++;
rcu_read_unlock_bh();
return err;
}
static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct file *file = iocb->ki_filp;
ssize_t result = -ENOLINK;
struct macvtap_queue *q = file->private_data;
result = macvtap_get_user(q, iv, iov_length(iv, count),
file->f_flags & O_NONBLOCK);
return result;
}
/* Put packet to the user space buffer */
static ssize_t macvtap_put_user(struct macvtap_queue *q,
const struct sk_buff *skb,
const struct iovec *iv, int len)
{
struct macvlan_dev *vlan;
int ret;
int vnet_hdr_len = 0;
if (q->flags & IFF_VNET_HDR) {
struct virtio_net_hdr vnet_hdr;
vnet_hdr_len = q->vnet_hdr_sz;
if ((len -= vnet_hdr_len) < 0)
return -EINVAL;
ret = macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
if (ret)
return ret;
if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
return -EFAULT;
}
len = min_t(int, skb->len, len);
ret = skb_copy_datagram_const_iovec(skb, 0, iv, vnet_hdr_len, len);
rcu_read_lock_bh();
vlan = rcu_dereference(q->vlan);
if (vlan)
macvlan_count_rx(vlan, len, ret == 0, 0);
rcu_read_unlock_bh();
return ret ? ret : (len + vnet_hdr_len);
}
static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
const struct iovec *iv, unsigned long len,
int noblock)
{
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t ret = 0;
add_wait_queue(sk_sleep(&q->sk), &wait);
while (len) {
current->state = TASK_INTERRUPTIBLE;
/* Read frames from the queue */
skb = skb_dequeue(&q->sk.sk_receive_queue);
if (!skb) {
if (noblock) {
ret = -EAGAIN;
break;
}
if (signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
/* Nothing to read, let's sleep */
schedule();
continue;
}
ret = macvtap_put_user(q, skb, iv, len);
kfree_skb(skb);
break;
}
current->state = TASK_RUNNING;
remove_wait_queue(sk_sleep(&q->sk), &wait);
return ret;
}
static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct macvtap_queue *q = file->private_data;
ssize_t len, ret = 0;
len = iov_length(iv, count);
if (len < 0) {
ret = -EINVAL;
goto out;
}
ret = macvtap_do_read(q, iocb, iv, len, file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len); /* XXX copied from tun.c. Why? */
out:
return ret;
}
/*
* provide compatibility with generic tun/tap interface
*/
static long macvtap_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct macvtap_queue *q = file->private_data;
struct macvlan_dev *vlan;
void __user *argp = (void __user *)arg;
struct ifreq __user *ifr = argp;
unsigned int __user *up = argp;
unsigned int u;
int __user *sp = argp;
int s;
int ret;
switch (cmd) {
case TUNSETIFF:
/* ignore the name, just look at flags */
if (get_user(u, &ifr->ifr_flags))
return -EFAULT;
ret = 0;
if ((u & ~IFF_VNET_HDR) != (IFF_NO_PI | IFF_TAP))
ret = -EINVAL;
else
q->flags = u;
return ret;
case TUNGETIFF:
rcu_read_lock_bh();
vlan = rcu_dereference(q->vlan);
if (vlan)
dev_hold(vlan->dev);
rcu_read_unlock_bh();
if (!vlan)
return -ENOLINK;
ret = 0;
if (copy_to_user(&ifr->ifr_name, q->vlan->dev->name, IFNAMSIZ) ||
put_user(q->flags, &ifr->ifr_flags))
ret = -EFAULT;
dev_put(vlan->dev);
return ret;
case TUNGETFEATURES:
if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR, up))
return -EFAULT;
return 0;
case TUNSETSNDBUF:
if (get_user(u, up))
return -EFAULT;
q->sk.sk_sndbuf = u;
return 0;
case TUNGETVNETHDRSZ:
s = q->vnet_hdr_sz;
if (put_user(s, sp))
return -EFAULT;
return 0;
case TUNSETVNETHDRSZ:
if (get_user(s, sp))
return -EFAULT;
if (s < (int)sizeof(struct virtio_net_hdr))
return -EINVAL;
q->vnet_hdr_sz = s;
return 0;
case TUNSETOFFLOAD:
/* let the user check for future flags */
if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
TUN_F_TSO_ECN | TUN_F_UFO))
return -EINVAL;
/* TODO: only accept frames with the features that
got enabled for forwarded frames */
if (!(q->flags & IFF_VNET_HDR))
return -EINVAL;
return 0;
default:
return -EINVAL;
}
}
#ifdef CONFIG_COMPAT
static long macvtap_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static const struct file_operations macvtap_fops = {
.owner = THIS_MODULE,
.open = macvtap_open,
.release = macvtap_release,
.aio_read = macvtap_aio_read,
.aio_write = macvtap_aio_write,
.poll = macvtap_poll,
.llseek = no_llseek,
.unlocked_ioctl = macvtap_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = macvtap_compat_ioctl,
#endif
};
static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
return macvtap_get_user(q, m->msg_iov, total_len,
m->msg_flags & MSG_DONTWAIT);
}
static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len,
int flags)
{
struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
int ret;
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
return -EINVAL;
ret = macvtap_do_read(q, 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;
}
return ret;
}
/* Ops structure to mimic raw sockets with tun */
static const struct proto_ops macvtap_socket_ops = {
.sendmsg = macvtap_sendmsg,
.recvmsg = macvtap_recvmsg,
};
/* Get an underlying socket object from tun file. Returns error unless file is
* attached to a device. The returned object works like a packet socket, it
* can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
* holding a reference to the file for as long as the socket is in use. */
struct socket *macvtap_get_socket(struct file *file)
{
struct macvtap_queue *q;
if (file->f_op != &macvtap_fops)
return ERR_PTR(-EINVAL);
q = file->private_data;
if (!q)
return ERR_PTR(-EBADFD);
return &q->sock;
}
EXPORT_SYMBOL_GPL(macvtap_get_socket);
static int macvtap_init(void)
{
int err;
err = alloc_chrdev_region(&macvtap_major, 0,
MACVTAP_NUM_DEVS, "macvtap");
if (err)
goto out1;
cdev_init(&macvtap_cdev, &macvtap_fops);
err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS);
if (err)
goto out2;
macvtap_class = class_create(THIS_MODULE, "macvtap");
if (IS_ERR(macvtap_class)) {
err = PTR_ERR(macvtap_class);
goto out3;
}
err = macvlan_link_register(&macvtap_link_ops);
if (err)
goto out4;
return 0;
out4:
class_unregister(macvtap_class);
out3:
cdev_del(&macvtap_cdev);
out2:
unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
out1:
return err;
}
module_init(macvtap_init);
static void macvtap_exit(void)
{
rtnl_link_unregister(&macvtap_link_ops);
class_unregister(macvtap_class);
cdev_del(&macvtap_cdev);
unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
}
module_exit(macvtap_exit);
MODULE_ALIAS_RTNL_LINK("macvtap");
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");