diff options
| author | Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> | 2026-01-31 23:25:05 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-02-26 15:01:10 -0800 |
| commit | 96d23737532feaa6bd00932cc5e8a7c6d6fb409f (patch) | |
| tree | 90cc4f146c599a8d20a19d2f5c6a3443bb128b48 /include/net/tcp.h | |
| parent | df64ca7b3849c95e9d0fcac33c3d9cb7a9b95191 (diff) | |
tcp: disable RFC3168 fallback identifier for CC modules
[ Upstream commit e68c28f22f46ecfdec3656ae785dd8ccbb4d557d ]
When AccECN is not successfully negociated for a TCP flow, it defaults
fallback to classic ECN (RFC3168). However, L4S service will fallback
to non-ECN.
This patch enables congestion control module to control whether it
should not fallback to classic ECN after unsuccessful AccECN negotiation.
A new CA module flag (TCP_CONG_NO_FALLBACK_RFC3168) identifies this
behavior expected by the CA.
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/20260131222515.8485-6-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: c5ff6b837159 ("tcp: accecn: handle unexpected AccECN negotiation feedback")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index c4c25f2e0c0d..e0a5cf2f7818 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1207,8 +1207,11 @@ enum tcp_ca_ack_event_flags { #define TCP_CONG_NEEDS_ACCECN BIT(2) /* Use ECT(1) instead of ECT(0) while the CA is uninitialized */ #define TCP_CONG_ECT_1_NEGOTIATION BIT(3) +/* Cannot fallback to RFC3168 during AccECN negotiation */ +#define TCP_CONG_NO_FALLBACK_RFC3168 BIT(4) #define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN | \ - TCP_CONG_NEEDS_ACCECN | TCP_CONG_ECT_1_NEGOTIATION) + TCP_CONG_NEEDS_ACCECN | TCP_CONG_ECT_1_NEGOTIATION | \ + TCP_CONG_NO_FALLBACK_RFC3168) union tcp_cc_info; @@ -1354,6 +1357,13 @@ static inline bool tcp_ca_ect_1_negotiation(const struct sock *sk) return icsk->icsk_ca_ops->flags & TCP_CONG_ECT_1_NEGOTIATION; } +static inline bool tcp_ca_no_fallback_rfc3168(const struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + return icsk->icsk_ca_ops->flags & TCP_CONG_NO_FALLBACK_RFC3168; +} + static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) { const struct inet_connection_sock *icsk = inet_csk(sk); |