On Thu, 26 Sep 2024 16:04:14 +0200 Laurent Vivier <lvivier(a)redhat.com> wrote:TCP header and payload are supposed to be in the same buffer, and tcp_update_check_tcp4()/tcp_update_check_tcp6() compute the checksum from the base address of the header using the length of the IP payload. In the future (for vhost-user) we need to dispatch the TCP header and the TCP payload through several buffers. To be able to manage that, we provide an iovec array that points to the data of the TCP frame. We provide also an offset to be able to provide an array that contains the TCP frame embedded in an lower level frame, and this offset points to the TCP header inside the iovec array. Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>It looks like you missed David's comments from: ZvS8wXSMfoexsqXr(a)zatzit.fritz.box https://archives.passt.top/passt-dev/ZvS8wXSMfoexsqXr@zatzit.fritz.box/ Other than those, this looks good to me. -- Stefano