On Mon, 27 Mar 2023 14:56:32 +1100 David Gibson <david(a)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 synThanks 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