diff options
| author | Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> | 2026-01-31 23:25:12 +0100 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-02-03 15:13:25 +0100 |
| commit | 1247fb19cafee6f9fa350ae378e4e1e9965cc253 (patch) | |
| tree | 589132e1d1423ae8ee2ec9fd6d52c6182a161224 /include/linux | |
| parent | 2ed661248e2b920f53db61ddfc74bc68ed10c83d (diff) | |
tcp: accecn: detect loss ACK w/ AccECN option and add TCP_ACCECN_OPTION_PERSIST
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 <chia-yu.chang@nokia-bell-labs.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260131222515.8485-13-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/tcp.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index fbc514d582e7..f72eef31fa23 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -291,7 +291,8 @@ struct tcp_sock { u8 nonagle : 4,/* Disable Nagle algorithm? */ rate_app_limited:1; /* rate_{delivered,interval_us} limited? */ u8 received_ce_pending:4, /* Not yet transmit cnt of received_ce */ - unused2:4; + accecn_opt_sent_w_dsack:1,/* Sent ACCECN opt in previous ACK w/ D-SACK */ + unused2:3; u8 accecn_minlen:2,/* Minimum length of AccECN option sent */ est_ecnfield:2,/* ECN field for AccECN delivered estimates */ accecn_opt_demand:2,/* Demand AccECN option for n next ACKs */ |