Re: [lwip-devel] Re: [task #7040] Work on tcp_enqueue

[address@hidden]

Jakob Stoklund Olesen wrote:
> Right. Do you think my proposals for TCP are a detour from a unified
> solution? I think the requirements for TCP and UDP/UDPLite are different
> enough that little can be shared.
>
> I would probably make these functions:
>
> inet_chksum_pseudo_header(): inet_chksum_pseudo without payload.
> inet_chksum_memcpy(): Checksumming memcpy.
>
> They would be useful for UDP as well.
>
> For TCP, a checksum field in the pbuf is not really that useful. A
> data_csum field in tcp_seg might be, but it is not strictly necessary.

I guess that's OK. If we move on with patch #6253, we can still change 
the TCP code to use the saved checksum. We definitively would need a 
function/macro that adds 2 checksums to one and takes care of correct 
wraparound (I remember we had a bug there some time - better to have it 
only in one place).

Simon