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tap: support receiving skb from msg_control

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This patch makes tap_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 12:14:44 +08:00 committed by David S. Miller
parent ac77cfd425
commit 3b4ba04acc
1 changed files with 8 additions and 4 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

12
drivers/net/tap.c
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@ -824,15 +824,17 @@ static ssize_t tap_put_user(struct tap_queue *q,
static ssize_t tap_do_read(struct tap_queue *q,
struct iov_iter *to,
int noblock)
int noblock, struct sk_buff *skb)
{
DEFINE_WAIT(wait);
struct sk_buff *skb;
ssize_t ret = 0;
if (!iov_iter_count(to))
return 0;
if (skb)
goto put;
while (1) {
if (!noblock)
prepare_to_wait(sk_sleep(&q->sk), &wait,
@ -856,6 +858,7 @@ static ssize_t tap_do_read(struct tap_queue *q,
if (!noblock)
finish_wait(sk_sleep(&q->sk), &wait);
put:
if (skb) {
ret = tap_put_user(q, skb, to);
if (unlikely(ret < 0))
@ -872,7 +875,7 @@ static ssize_t tap_read_iter(struct kiocb *iocb, struct iov_iter *to)
struct tap_queue *q = file->private_data;
ssize_t len = iov_iter_count(to), ret;
ret = tap_do_read(q, to, file->f_flags & O_NONBLOCK);
ret = tap_do_read(q, to, file->f_flags & O_NONBLOCK, NULL);
ret = min_t(ssize_t, ret, len);
if (ret > 0)
iocb->ki_pos = ret;
@ -1155,7 +1158,8 @@ static int tap_recvmsg(struct socket *sock, struct msghdr *m,
int ret;
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
return -EINVAL;
ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT);
ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT,
m->msg_control);
if (ret > total_len) {
m->msg_flags |= MSG_TRUNC;
ret = flags & MSG_TRUNC ? ret : total_len;