On Sat, Jan 31, 2026 at 11:26 PM <[email protected]> wrote: > > From: Chia-Yu Chang <[email protected]> > > Detect spurious retransmission of a previously sent ACK carrying the > AccECN option after the second retransmission. Since this might be caused > by the middlebox dropping ACK with options it does not recognize, disable > the sending of the AccECN option in all subsequent ACKs. This patch > follows Section 3.2.3.2.2 of AccECN spec (RFC9768), and a new field > (accecn_opt_sent_w_dsack) is added to indicate that an AccECN option was > sent with duplicate SACK info. > > Also, a new AccECN option sending mode is added to tcp_ecn_option sysctl: > (TCP_ECN_OPTION_PERSIST), which ignores the AccECN fallback policy and > persistently sends AccECN option once it fits into TCP option space. > > Signed-off-by: Chia-Yu Chang <[email protected]> > Acked-by: Paolo Abeni <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
