Re: [PATCH net 1/2] mptcp: only inc MPJoinAckHMacFailure for HMAC failures

[Simon Horman]

On Mon, Apr 07, 2025 at 08:26:32PM +0200, Matthieu Baerts (NGI0) wrote:
> Recently, during a debugging session using local MPTCP connections, I
> noticed MPJoinAckHMacFailure was not zero on the server side. The
> counter was in fact incremented when the PM rejected new subflows,
> because the 'subflow' limit was reached.
> 
> The fix is easy, simply dissociating the two cases: only the HMAC
> validation check should increase MPTCP_MIB_JOINACKMAC counter.
> 
> Fixes: 4cf8b7e48a09 ("subflow: introduce and use mptcp_can_accept_new_subflow()")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Geliang Tang <geliang@xxxxxxxxxx>
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>