tree b355e804e53334d5930f34cfcca0beeb4465af63
parent 3d45296ab96c2ec8308226b3350a6d9e48379870
author Yuchung Cheng <ycheng@google.com> 1454109110 -0800
committer David S. Miller <davem@davemloft.net> 1454137436 -0800

tcp: avoid cwnd undo after receiving ECN

RFC 4015 section 3.4 says the TCP sender MUST refrain from
reversing the congestion control state when the ACK signals
congestion through the ECN-Echo flag. Currently we may not
always do that when prior_ssthresh is reset upon receiving
ACKs with ECE marks. This patch fixes that.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>