summaryrefslogtreecommitdiff
path: root/include/linux
diff options
context:
space:
mode:
authorChia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>2026-01-31 23:25:09 +0100
committerPaolo Abeni <pabeni@redhat.com>2026-02-03 15:13:24 +0100
commitf326f1f17f3772dae4b37360c639ed6b76fe6354 (patch)
treef5630d5f39ee666b78b7e111ab0e6449be1ffaf4 /include/linux
parentf1eaea5585e4d193e007d671f0916f4371c72c0b (diff)
tcp: accecn: retransmit SYN/ACK without AccECN option or non-AccECN SYN/ACK
For Accurate ECN, the first SYN/ACK sent by the TCP server shall set the ACE flag (Table 1 of RFC9768) and the AccECN option to complete the capability negotiation. However, if the TCP server needs to retransmit such a SYN/ACK (for example, because it did not receive an ACK acknowledging its SYN/ACK, or received a second SYN requesting AccECN support), the TCP server retransmits the SYN/ACK without the AccECN option. This is because the SYN/ACK may be lost due to congestion, or a middlebox may block the AccECN option. Furthermore, if this retransmission also times out, to expedite connection establishment, the TCP server should retransmit the SYN/ACK with (AE,CWR,ECE) = (0,0,0) and without the AccECN option, while maintaining AccECN feedback mode. This complies with Section 3.2.3.2.2 of the AccECN spec RFC9768. Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260131222515.8485-10-chia-yu.chang@nokia-bell-labs.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/linux')
0 files changed, 0 insertions, 0 deletions