mptcp: don't send RST for single subflow

When a bad checksum is detected and a single subflow is in use, don't
send RST + MP_FAIL, send data_ack + MP_FAIL instead.

So invoke tcp_send_active_reset() only when mptcp_has_another_subflow()
is true.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index aba260f..f217926 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1206,14 +1206,14 @@ fallback:
        /* RFC 8684 section 3.7. */
        if (subflow->send_mp_fail) {
                if (mptcp_has_another_subflow(ssk)) {
+                       ssk->sk_err = EBADMSG;
+                       tcp_set_state(ssk, TCP_CLOSE);
+                       subflow->reset_transient = 0;
+                       subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
+                       tcp_send_active_reset(ssk, GFP_ATOMIC);
                        while ((skb = skb_peek(&ssk->sk_receive_queue)))
                                sk_eat_skb(ssk, skb);
                }
-               ssk->sk_err = EBADMSG;
-               tcp_set_state(ssk, TCP_CLOSE);
-               subflow->reset_transient = 0;
-               subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
-               tcp_send_active_reset(ssk, GFP_ATOMIC);
                WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
                return true;
        }