[gnutls-help] [gnutls-devel] the problem about "stream usage" in dtls/sctp

[Nikos Mavrogiannopoulos]

On Sun, 2017-05-14 at 13:05 +0100, Jeremy Harris wrote:
> On 14/05/17 08:43, Nikos Mavrogiannopoulos wrote:
> > The API however was designed for TCP/UDP and although there are few
> > instructions at [1], I'm not happy with that. We need simpler
> > functions
> > to handle SCTP.
> 
> Somewhat related
> 
> - the equivalent of send( , , , MSG_MORE).  I could do it with a push
>   function, but that's just more hassle and I'd only be using it for
>   my application protocol startup sequence anyway.

You can use the gnutls_record_cork() and uncork functions for that.
Would that work for you, or did I miss the context?

> - would there be any benefit in a sendfile() equivalent?  I assume
> not
>   for a userland/cpu driven session encryption engine - but are there
>   any hardware engine implementations?

There is AF_KTLS [0] which can work with gnutls and can be used to
achieve sendfile-like functionality. However I do not know whether
something like that would ever reach mainline linux kernel. What
functionality/optimization do you have in mind?

[0]. https://github.com/ktls/af_ktls

regards,
Nikos