From 3b4ba04acca8f98a62fd014a0826ea10bc93cde3 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 17 May 2017 12:14:44 +0800 Subject: tap: support receiving skb from msg_control 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 Signed-off-by: David S. Miller --- drivers/net/tap.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'drivers/net/tap.c') diff --git a/drivers/net/tap.c b/drivers/net/tap.c index abdaf867774d..9af3239d6ad5 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -824,15 +824,17 @@ done: 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; -- cgit v1.2.3-59-g8ed1b