Re: [PATCH 0/2] tcp: Correct handling of first ACK (or SYN-ACK) packet

[Stefano Brivio <sbrivio@redhat.com>]

On Mon, 27 Mar 2023 14:56:32 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> We have a subtle problem in the handling of the very first ack-flagged
> packet (either the SYN-ACK or ACK from the three way handshake).
> Stefano has posted a couple of versions of a patch addressing this,
> however I think this is a better approach.  From the TCP logical point
> of view, that first ACK does advance the sequence number, and if we
> treat it as doing so, then the logic we already had in
> tcp_update_seqack_from_tap() is correct.
> 
> David Gibson (2):
>   tcp: Clarify allowed state for tcp_data_from_tap()
>   tcp: Don't special case the handling of the ack of a syn

Thanks for fixing this, the series looks good to me.

I'm wondering if we should still apply the v2 of the patch I sent, with
an adjusted commit message, because resetting ACK_FROM_TAP_DUE only on
SEQ_GT(seq, conn->seq_ack_from_tap) doesn't really follow any logic,
even though it wouldn't be a problem at this point.

-- 
Stefano