[PATCH 5.18 72/88] mptcp: dont send RST for single subflow

From: Greg Kroah-Hartman
Date: Mon Aug 01 2022 - 08:17:26 EST


From: Geliang Tang <geliang.tang@xxxxxxxx>

[ Upstream commit 1761fed2567807f26fbd53032ff622f55978c7a9 ]

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@xxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/mptcp/subflow.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 7919e259175d..ccae50eba664 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1221,14 +1221,14 @@ static bool subflow_check_data_avail(struct sock *ssk)
/* 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;
}
--
2.35.1