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![Michael S. Tsirkin](/assets/img/avatar_default.png)
This adds TUNSETVNETHDRSZ/TUNGETVNETHDRSZ support to macvtap. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David S. Miller <davem@davemloft.net>
828 lines
20 KiB
C
828 lines
20 KiB
C
#include <linux/etherdevice.h>
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#include <linux/if_macvlan.h>
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#include <linux/interrupt.h>
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#include <linux/nsproxy.h>
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#include <linux/compat.h>
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#include <linux/if_tun.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/cache.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/cdev.h>
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#include <linux/fs.h>
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#include <net/net_namespace.h>
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#include <net/rtnetlink.h>
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#include <net/sock.h>
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#include <linux/virtio_net.h>
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/*
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* A macvtap queue is the central object of this driver, it connects
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* an open character device to a macvlan interface. There can be
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* multiple queues on one interface, which map back to queues
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* implemented in hardware on the underlying device.
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*
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* macvtap_proto is used to allocate queues through the sock allocation
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* mechanism.
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*
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* TODO: multiqueue support is currently not implemented, even though
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* macvtap is basically prepared for that. We will need to add this
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* here as well as in virtio-net and qemu to get line rate on 10gbit
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* adapters from a guest.
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*/
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struct macvtap_queue {
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struct sock sk;
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struct socket sock;
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struct socket_wq wq;
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int vnet_hdr_sz;
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struct macvlan_dev *vlan;
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struct file *file;
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unsigned int flags;
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};
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static struct proto macvtap_proto = {
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.name = "macvtap",
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.owner = THIS_MODULE,
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.obj_size = sizeof (struct macvtap_queue),
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};
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/*
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* Minor number matches netdev->ifindex, so need a potentially
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* large value. This also makes it possible to split the
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* tap functionality out again in the future by offering it
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* from other drivers besides macvtap. As long as every device
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* only has one tap, the interface numbers assure that the
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* device nodes are unique.
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*/
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static unsigned int macvtap_major;
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#define MACVTAP_NUM_DEVS 65536
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static struct class *macvtap_class;
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static struct cdev macvtap_cdev;
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static const struct proto_ops macvtap_socket_ops;
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/*
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* RCU usage:
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* The macvtap_queue and the macvlan_dev are loosely coupled, the
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* pointers from one to the other can only be read while rcu_read_lock
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* or macvtap_lock is held.
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*
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* Both the file and the macvlan_dev hold a reference on the macvtap_queue
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* through sock_hold(&q->sk). When the macvlan_dev goes away first,
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* q->vlan becomes inaccessible. When the files gets closed,
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* macvtap_get_queue() fails.
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*
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* There may still be references to the struct sock inside of the
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* queue from outbound SKBs, but these never reference back to the
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* file or the dev. The data structure is freed through __sk_free
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* when both our references and any pending SKBs are gone.
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*/
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static DEFINE_SPINLOCK(macvtap_lock);
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/*
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* Choose the next free queue, for now there is only one
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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 (rcu_dereference(vlan->tap))
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goto out;
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err = 0;
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rcu_assign_pointer(q->vlan, vlan);
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rcu_assign_pointer(vlan->tap, q);
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sock_hold(&q->sk);
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q->file = file;
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file->private_data = q;
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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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/*
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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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* one from the macvlan_dev if that still exists.
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*
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* Using the spinlock makes sure that we don't get
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* to the queue again after destroying it.
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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 macvlan_dev *vlan;
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spin_lock(&macvtap_lock);
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vlan = rcu_dereference(q->vlan);
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if (vlan) {
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rcu_assign_pointer(vlan->tap, NULL);
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rcu_assign_pointer(q->vlan, NULL);
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sock_put(&q->sk);
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}
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spin_unlock(&macvtap_lock);
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synchronize_rcu();
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sock_put(&q->sk);
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}
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/*
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* Since we only support one queue, just dereference the pointer.
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*/
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static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
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struct sk_buff *skb)
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{
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struct macvlan_dev *vlan = netdev_priv(dev);
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return rcu_dereference(vlan->tap);
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}
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/*
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* The net_device is going away, give up the reference
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* that it holds on the queue (all the queues one day)
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* and safely set the pointer from the queues to NULL.
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*/
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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;
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spin_lock(&macvtap_lock);
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q = rcu_dereference(vlan->tap);
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if (!q) {
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spin_unlock(&macvtap_lock);
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return;
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}
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rcu_assign_pointer(vlan->tap, NULL);
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rcu_assign_pointer(q->vlan, NULL);
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spin_unlock(&macvtap_lock);
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synchronize_rcu();
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sock_put(&q->sk);
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}
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/*
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* Forward happens for data that gets sent from one macvlan
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* endpoint to another one in bridge mode. We just take
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* the skb and put it into the receive queue.
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*/
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static int macvtap_forward(struct net_device *dev, struct sk_buff *skb)
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{
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struct macvtap_queue *q = macvtap_get_queue(dev, skb);
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if (!q)
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return -ENOLINK;
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skb_queue_tail(&q->sk.sk_receive_queue, skb);
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wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
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return 0;
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}
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/*
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* Receive is for data from the external interface (lowerdev),
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* in case of macvtap, we can treat that the same way as
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* forward, which macvlan cannot.
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*/
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static int macvtap_receive(struct sk_buff *skb)
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{
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skb_push(skb, ETH_HLEN);
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return macvtap_forward(skb->dev, skb);
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}
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static int macvtap_newlink(struct net *src_net,
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struct net_device *dev,
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struct nlattr *tb[],
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struct nlattr *data[])
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{
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struct device *classdev;
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dev_t devt;
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int err;
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err = macvlan_common_newlink(src_net, dev, tb, data,
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macvtap_receive, macvtap_forward);
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if (err)
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goto out;
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devt = MKDEV(MAJOR(macvtap_major), dev->ifindex);
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classdev = device_create(macvtap_class, &dev->dev, devt,
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dev, "tap%d", dev->ifindex);
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if (IS_ERR(classdev)) {
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err = PTR_ERR(classdev);
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macvtap_del_queues(dev);
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}
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out:
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return err;
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}
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static void macvtap_dellink(struct net_device *dev,
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struct list_head *head)
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{
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device_destroy(macvtap_class,
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MKDEV(MAJOR(macvtap_major), dev->ifindex));
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macvtap_del_queues(dev);
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macvlan_dellink(dev, head);
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}
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static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
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.kind = "macvtap",
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.newlink = macvtap_newlink,
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.dellink = macvtap_dellink,
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};
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static void macvtap_sock_write_space(struct sock *sk)
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{
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wait_queue_head_t *wqueue;
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if (!sock_writeable(sk) ||
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!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
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return;
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wqueue = sk_sleep(sk);
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if (wqueue && waitqueue_active(wqueue))
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wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
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}
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static int macvtap_open(struct inode *inode, struct file *file)
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{
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struct net *net = current->nsproxy->net_ns;
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struct net_device *dev = dev_get_by_index(net, iminor(inode));
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struct macvtap_queue *q;
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int err;
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err = -ENODEV;
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if (!dev)
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goto out;
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/* check if this is a macvtap device */
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err = -EINVAL;
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if (dev->rtnl_link_ops != &macvtap_link_ops)
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goto out;
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err = -ENOMEM;
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q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
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&macvtap_proto);
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if (!q)
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goto out;
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q->sock.wq = &q->wq;
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init_waitqueue_head(&q->wq.wait);
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q->sock.type = SOCK_RAW;
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q->sock.state = SS_CONNECTED;
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q->sock.file = file;
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q->sock.ops = &macvtap_socket_ops;
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sock_init_data(&q->sock, &q->sk);
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q->sk.sk_write_space = macvtap_sock_write_space;
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q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
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q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
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err = macvtap_set_queue(dev, file, q);
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if (err)
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sock_put(&q->sk);
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out:
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if (dev)
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dev_put(dev);
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return err;
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}
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static int macvtap_release(struct inode *inode, struct file *file)
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{
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struct macvtap_queue *q = file->private_data;
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macvtap_put_queue(q);
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return 0;
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}
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static unsigned int macvtap_poll(struct file *file, poll_table * wait)
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{
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struct macvtap_queue *q = file->private_data;
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unsigned int mask = POLLERR;
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if (!q)
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goto out;
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mask = 0;
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poll_wait(file, &q->wq.wait, wait);
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if (!skb_queue_empty(&q->sk.sk_receive_queue))
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mask |= POLLIN | POLLRDNORM;
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if (sock_writeable(&q->sk) ||
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(!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
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sock_writeable(&q->sk)))
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mask |= POLLOUT | POLLWRNORM;
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out:
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return mask;
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}
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static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
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size_t len, size_t linear,
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int noblock, int *err)
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{
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struct sk_buff *skb;
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/* Under a page? Don't bother with paged skb. */
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if (prepad + len < PAGE_SIZE || !linear)
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linear = len;
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skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
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err);
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if (!skb)
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return NULL;
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skb_reserve(skb, prepad);
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skb_put(skb, linear);
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skb->data_len = len - linear;
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skb->len += len - linear;
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return skb;
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}
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/*
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* macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
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* be shared with the tun/tap driver.
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*/
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static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
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struct virtio_net_hdr *vnet_hdr)
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{
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unsigned short gso_type = 0;
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if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
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switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
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case VIRTIO_NET_HDR_GSO_TCPV4:
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gso_type = SKB_GSO_TCPV4;
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break;
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case VIRTIO_NET_HDR_GSO_TCPV6:
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gso_type = SKB_GSO_TCPV6;
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break;
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case VIRTIO_NET_HDR_GSO_UDP:
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gso_type = SKB_GSO_UDP;
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break;
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default:
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return -EINVAL;
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}
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if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
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gso_type |= SKB_GSO_TCP_ECN;
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if (vnet_hdr->gso_size == 0)
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return -EINVAL;
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}
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if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
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if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
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vnet_hdr->csum_offset))
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return -EINVAL;
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}
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if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
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skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
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skb_shinfo(skb)->gso_type = gso_type;
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/* Header must be checked, and gso_segs computed. */
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skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
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skb_shinfo(skb)->gso_segs = 0;
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}
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return 0;
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}
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static int macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
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struct virtio_net_hdr *vnet_hdr)
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{
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memset(vnet_hdr, 0, sizeof(*vnet_hdr));
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if (skb_is_gso(skb)) {
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struct skb_shared_info *sinfo = skb_shinfo(skb);
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/* This is a hint as to how much should be linear. */
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vnet_hdr->hdr_len = skb_headlen(skb);
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vnet_hdr->gso_size = sinfo->gso_size;
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if (sinfo->gso_type & SKB_GSO_TCPV4)
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vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
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else if (sinfo->gso_type & SKB_GSO_TCPV6)
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vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
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else if (sinfo->gso_type & SKB_GSO_UDP)
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vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
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else
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BUG();
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if (sinfo->gso_type & SKB_GSO_TCP_ECN)
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vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
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} else
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vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
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|
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if (skb->ip_summed == CHECKSUM_PARTIAL) {
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vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
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vnet_hdr->csum_start = skb->csum_start -
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skb_headroom(skb);
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vnet_hdr->csum_offset = skb->csum_offset;
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} /* else everything is zero */
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|
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return 0;
|
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}
|
|
|
|
|
|
/* Get packet from user space buffer */
|
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static ssize_t macvtap_get_user(struct macvtap_queue *q,
|
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const struct iovec *iv, size_t count,
|
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int noblock)
|
|
{
|
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struct sk_buff *skb;
|
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struct macvlan_dev *vlan;
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size_t len = count;
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int err;
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struct virtio_net_hdr vnet_hdr = { 0 };
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|
int vnet_hdr_len = 0;
|
|
|
|
if (q->flags & IFF_VNET_HDR) {
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|
vnet_hdr_len = q->vnet_hdr_sz;
|
|
|
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err = -EINVAL;
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|
if ((len -= vnet_hdr_len) < 0)
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|
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)
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vnet_hdr.hdr_len = vnet_hdr.csum_start +
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vnet_hdr.csum_offset + 2;
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err = -EINVAL;
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|
if (vnet_hdr.hdr_len > len)
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goto err;
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|
}
|
|
|
|
err = -EINVAL;
|
|
if (unlikely(len < ETH_HLEN))
|
|
goto err;
|
|
|
|
skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, len, vnet_hdr.hdr_len,
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noblock, &err);
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if (!skb)
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goto err;
|
|
|
|
err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len, len);
|
|
if (err)
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|
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");
|