[PATCH 6.1 100/215] mptcp: continue marking the first subflow as UNCONNECTED

Greg Kroah-Hartman
2024-03-04T21:47:43Z

From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>

After the 'Fixes' commit mentioned below, which is a partial backport,
the MPTCP worker was no longer marking the first subflow as "UNCONNECTED"
when the socket was transitioning to TCP_CLOSE state.

As a result, in v6.1, it was no longer possible to reconnect to the just
disconnected socket. Continue to do that like before, only for the first
subflow.

A few refactoring have been done around the 'msk->subflow' in later
versions, and it looks like this is not needed to do that there, but
still needed in v6.1. Without that, the 'disconnect' tests from the
mptcp_connect.sh selftest fail: they repeat the transfer 3 times by
reconnecting to the server each time.

Fixes: 7857e35ef10e ("mptcp: get rid of msk->subflow")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mptcp/protocol.c | 2 ++
1 file changed, 2 insertions(+)

--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2440,6 +2440,8 @@ static void __mptcp_close_ssk(struct soc
need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
if (!dispose_it) {
__mptcp_subflow_disconnect(ssk, subflow, flags);
+ if (msk->subflow && ssk == msk->subflow->sk)
+ msk->subflow->state = SS_UNCONNECTED;
release_sock(ssk);

goto out;