Commit ca4fb892 authored by Yonglong Li's avatar Yonglong Li Committed by David S. Miller
Browse files

mptcp: add MSG_PEEK support 



This patch adds support for MSG_PEEK flag. Packets are not removed
from the receive_queue if MSG_PEEK set in recv() system call.

Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarYonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 987858e5

net/mptcp/protocol.c

+13 −9
Original line number Diff line number Diff line
@@ -1745,10 +1745,10 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, 
				struct msghdr *msg,

				size_t len, int flags)

{

	struct sk_buff *skb;

	struct sk_buff *skb, *tmp;

	int copied = 0;



	while ((skb = skb_peek(&msk->receive_queue)) != NULL) {

	skb_queue_walk_safe(&msk->receive_queue, skb, tmp) {

		u32 offset = MPTCP_SKB_CB(skb)->offset;

		u32 data_len = skb->len - offset;

		u32 count = min_t(size_t, len - copied, data_len);
@@ -1766,15 +1766,18 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, 
		copied += count;



		if (count < data_len) {

			if (!(flags & MSG_PEEK))

				MPTCP_SKB_CB(skb)->offset += count;

			break;

		}



		if (!(flags & MSG_PEEK)) {

			/* we will bulk release the skb memory later */

			skb->destructor = NULL;

			msk->rmem_released += skb->truesize;

			__skb_unlink(skb, &msk->receive_queue);

			__kfree_skb(skb);

		}



		if (copied >= len)

			break;
@@ -2053,6 +2056,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 
	pr_debug("msk=%p data_ready=%d rx queue empty=%d copied=%d",

		 msk, test_bit(MPTCP_DATA_READY, &msk->flags),

		 skb_queue_empty_lockless(&sk->sk_receive_queue), copied);

	if (!(flags & MSG_PEEK))

		mptcp_rcv_space_adjust(msk, copied);



	release_sock(sk);