tun: support receiving skb through msg_control

This patch makes tun_recvmsg() can receive from skb from its caller
through msg_control. Vhost_net will be the first user.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2017-05-17 12:14:43 +08:00 committed by David S. Miller
parent 49f96fd0cb
commit ac77cfd425

View file

@ -1510,9 +1510,8 @@ static struct sk_buff *tun_ring_recv(struct tun_file *tfile, int noblock,
static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
struct iov_iter *to,
int noblock)
int noblock, struct sk_buff *skb)
{
struct sk_buff *skb;
ssize_t ret;
int err;
@ -1521,10 +1520,12 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
if (!iov_iter_count(to))
return 0;
/* Read frames from ring */
skb = tun_ring_recv(tfile, noblock, &err);
if (!skb)
return err;
if (!skb) {
/* Read frames from ring */
skb = tun_ring_recv(tfile, noblock, &err);
if (!skb)
return err;
}
ret = tun_put_user(tun, tfile, skb, to);
if (unlikely(ret < 0))
@ -1544,7 +1545,7 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
if (!tun)
return -EBADFD;
ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK);
ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
@ -1646,7 +1647,8 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
SOL_PACKET, TUN_TX_TIMESTAMP);
goto out;
}
ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT);
ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT,
m->msg_control);
if (ret > (ssize_t)total_len) {
m->msg_flags |= MSG_TRUNC;
ret = flags & MSG_TRUNC ? ret : total_len;