From: Eric Dumazet <eric.duma...@gmail.com> Date: Tue, 23 May 2017 15:24:46 -0700
> Add a FLAG_NO_CHALLENGE_ACK so that tcp_rcv_state_process() > can choose to send a challenge ACK and discard the packet instead > of wrongly change socket state. Applied, but the tests end up being double-negatives so it might have been easier to understand if the flag was a positive rather than a negative value.
