[PATCH v6 net-next 03/14] net: update commnets for SKB_GSO_TCP_ECN and SKB_GSO_TCP_ACCECN
From: <hidden>
Date: 2025-11-14 07:14:01
Also in:
bpf, linux-doc, linux-kselftest
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Chia-Yu Chang <redacted> No functional changes. Co-developed-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <redacted> --- v6: - Update comments. --- include/linux/skbuff.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index ff90281ddf90..e09455cee8e3 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -671,7 +671,13 @@ enum { /* This indicates the skb is from an untrusted source. */ SKB_GSO_DODGY = 1 << 1, - /* This indicates the tcp segment has CWR set. */ + /* For Tx, this indicates the first TCP segment has CWR set, and any + * subsequent segment in the same skb has CWR cleared. This is not + * used on Rx except for virtio_net. However, because the connection + * to which the segment belongs is not tracked to use RFC3168 or + * Accurate ECN, and using RFC3168 ECN offload may corrupt AccECN + * signal of AccECN segments. Therefore, this cannot be used on Rx. + */ SKB_GSO_TCP_ECN = 1 << 2, __SKB_GSO_TCP_FIXEDID = 1 << 3,
@@ -706,6 +712,12 @@ enum { SKB_GSO_FRAGLIST = 1 << 18, + /* For TX, this indicates the TCP segment uses the CWR flag as part of + * AccECN signal, and the CWR flag is not modified in the skb. This is + * not used on Rx except for virtio_net. For RX, any CWR flagged segment + * must use SKB_GSO_TCP_ACCECN to ensure CWR flag is not cleared by any + * RFC3168 ECN offload, and thus keeping AccECN signal of TCP segments. + */ SKB_GSO_TCP_ACCECN = 1 << 19, /* These indirectly map onto the same netdev feature.
--
2.34.1