Commit 7ed90803 authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

mptcp: send explicit ack on delayed ack_seq incr 



When the worker moves some bytes from the OoO queue into
the receive queue, the msk->ask_seq is updated, the MPTCP-level
ack carrying that value needs to wait the next ingress packet,
possibly slowing down or hanging the peer

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6f8a612a

net/mptcp/protocol.c

+21 −13
Original line number Diff line number Diff line
@@ -407,13 +407,27 @@ static void mptcp_set_timeout(const struct sock *sk, const struct sock *ssk) 
	mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN;

}



static void mptcp_check_data_fin(struct sock *sk)

static void mptcp_send_ack(struct mptcp_sock *msk)

{

	struct mptcp_subflow_context *subflow;



	mptcp_for_each_subflow(msk, subflow) {

		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);



		lock_sock(ssk);

		tcp_send_ack(ssk);

		release_sock(ssk);

	}

}



static bool mptcp_check_data_fin(struct sock *sk)

{

	struct mptcp_sock *msk = mptcp_sk(sk);

	u64 rcv_data_fin_seq;

	bool ret = false;



	if (__mptcp_check_fallback(msk) || !msk->first)

		return;

		return ret;



	/* Need to ack a DATA_FIN received from a peer while this side

	 * of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2.
@@ -429,8 +443,6 @@ static void mptcp_check_data_fin(struct sock *sk) 
	 */



	if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) {

		struct mptcp_subflow_context *subflow;



		WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1);

		WRITE_ONCE(msk->rcv_data_fin, 0);
@@ -454,17 +466,12 @@ static void mptcp_check_data_fin(struct sock *sk) 
			break;

		}



		ret = true;

		mptcp_set_timeout(sk, NULL);

		mptcp_for_each_subflow(msk, subflow) {

			struct sock *ssk = mptcp_subflow_tcp_sock(subflow);



			lock_sock(ssk);

			tcp_send_ack(ssk);

			release_sock(ssk);

		}



		mptcp_send_ack(msk);

		mptcp_close_wake_up(sk);

	}

	return ret;

}



static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
@@ -1547,7 +1554,8 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) 
	} while (!done);



	if (mptcp_ofo_queue(msk) || moved > 0) {

		mptcp_check_data_fin((struct sock *)msk);

		if (!mptcp_check_data_fin((struct sock *)msk))

			mptcp_send_ack(msk);

		return true;

	}

	return false;

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