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-rw-r--r--drivers/net/macvtap.c803
1 files changed, 803 insertions, 0 deletions
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
new file mode 100644
index 00000000000..55ceae09738
--- /dev/null
+++ b/drivers/net/macvtap.c
@@ -0,0 +1,803 @@
+#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/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 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)
+ return -ENOLINK;
+
+ skb_queue_tail(&q->sk.sk_receive_queue, skb);
+ wake_up_interruptible_poll(q->sk.sk_sleep, POLLIN | POLLRDNORM | POLLRDBAND);
+ return 0;
+}
+
+/*
+ * 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 struct rtnl_link_ops macvtap_link_ops __read_mostly = {
+ .kind = "macvtap",
+ .newlink = macvtap_newlink,
+ .dellink = macvtap_dellink,
+};
+
+
+static void macvtap_sock_write_space(struct sock *sk)
+{
+ if (!sock_writeable(sk) ||
+ !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
+ return;
+
+ if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+ wake_up_interruptible_poll(sk->sk_sleep, 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;
+
+ init_waitqueue_head(&q->sock.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;
+
+ 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->sock.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 = sizeof(vnet_hdr);
+
+ err = -EINVAL;
+ if ((len -= vnet_hdr_len) < 0)
+ goto err;
+
+ err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
+ vnet_hdr_len);
+ 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 = sizeof (vnet_hdr);
+ 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, vnet_hdr_len))
+ 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(q->sk.sk_sleep, &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(q->sk.sk_sleep, &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 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 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");