net/macvtap: add vhost support
This adds support for passing a macvtap file descriptor into
vhost-net, much like we already do for tun/tap.
Most of the new code is taken from the respective patch
in the tun driver and may get consolidated in the future.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 7050997..e354501 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -58,6 +58,8 @@
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
@@ -176,7 +178,7 @@
return -ENOLINK;
skb_queue_tail(&q->sk.sk_receive_queue, skb);
- wake_up(q->sk.sk_sleep);
+ wake_up_interruptible_poll(q->sk.sk_sleep, POLLIN | POLLRDNORM | POLLRDBAND);
return 0;
}
@@ -242,7 +244,7 @@
return;
if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
- wake_up_interruptible_sync(sk->sk_sleep);
+ wake_up_interruptible_poll(sk->sk_sleep, POLLOUT | POLLWRNORM | POLLWRBAND);
}
static int macvtap_open(struct inode *inode, struct file *file)
@@ -270,6 +272,8 @@
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;
@@ -387,32 +391,20 @@
rcu_read_lock_bh();
vlan = rcu_dereference(q->vlan);
- macvlan_count_rx(vlan, len, ret == 0, 0);
+ if (vlan)
+ macvlan_count_rx(vlan, len, ret == 0, 0);
rcu_read_unlock_bh();
return ret ? ret : len;
}
-static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
- unsigned long count, loff_t pos)
+static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,
+ const struct iovec *iv, unsigned long len,
+ int noblock)
{
- struct file *file = iocb->ki_filp;
- struct macvtap_queue *q = file->private_data;
-
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
- ssize_t len, ret = 0;
-
- if (!q) {
- ret = -ENOLINK;
- goto out;
- }
-
- len = iov_length(iv, count);
- if (len < 0) {
- ret = -EINVAL;
- goto out;
- }
+ ssize_t ret = 0;
add_wait_queue(q->sk.sk_sleep, &wait);
while (len) {
@@ -421,7 +413,7 @@
/* Read frames from the queue */
skb = skb_dequeue(&q->sk.sk_receive_queue);
if (!skb) {
- if (file->f_flags & O_NONBLOCK) {
+ if (noblock) {
ret = -EAGAIN;
break;
}
@@ -440,7 +432,24 @@
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;
}
@@ -538,6 +547,53 @@
#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;