[PATCH net 4/4] mptcp: pm: do not remove closing subflows

From: Matthieu Baerts (NGI0)
Date: Tue Oct 08 2024 - 07:10:02 EST


In a previous fix, the in-kernel path-manager has been modified not to
retrigger the removal of a subflow if it was already closed, e.g. when
the initial subflow is removed, but kept in the subflows list.

To be complete, this fix should also skip the subflows that are in any
closing state: mptcp_close_ssk() will initiate the closure, but the
switch to the TCP_CLOSE state depends on the other peer.

Fixes: 58e1b66b4e4b ("mptcp: pm: do not remove already closed subflows")
Cc: stable@xxxxxxxxxxxxxxx
Suggested-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Acked-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>
---
net/mptcp/pm_netlink.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 64fe0e7d87d7323583ef9ee5909c833a78e727c2..f6f0a38a0750f82bc909f02a75beec980d951f1f 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -860,7 +860,8 @@ static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
u8 id = subflow_get_local_id(subflow);

- if (inet_sk_state_load(ssk) == TCP_CLOSE)
+ if ((1 << inet_sk_state_load(ssk)) &
+ (TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING | TCPF_CLOSE))
continue;
if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
continue;

--
2.45.2