NPT Request & Implement "multi" session support in C

[gkc]

Is your feature request related to a problem? Please describe.

• Recently we added "multi" support in the Dart client, daemon and srv - allowing for client and daemon to co-ordinate in creating multiple socket pair connections via the rvd (which already supported this behaviour)

Describe the solution you'd like

• The C daemon and srv should also support this feature

Describe alternatives you've considered

No response

Additional context

See also an addition to the feature proposed in this ticket

[gkc]

Suggesting this as P3 as it is not needed for our first release of the C daemon/srv

[XavierChanth]

I don't forsee us doing / needing this in the near future, moving to backlog

[XavierChanth]

Making 8 SP, and moving to triage, let's discuss whether we focus on adding this now, or really focus on getting ssh_request more robust first (my guess is we will focus on the latter).

[XavierChanth]

@realvarx in C right now only _daemonSideSingle is implmented from https://github.com/atsign-foundation/noports/blob/trunk/packages/dart/noports_core/lib/src/srv/srv_impl.dart

To start, srv needs to add support for --multi, and use the _daemonSideMulti approach when --multi is enabled. This can be tested by building and running with the dart sshnpd.

You can test by running npt, npt requests use --multi.

Note that to test properly, sshnpd will need to run with your development C version of srv, but npt will need to run with the dart srv, since the C version of srv doesn't support features need for npt / sshnp.

[XavierChanth]

Then we have to add the npt request flow from dart sshnpd into C sshnpd, most of which should be similar to the ssh request which is already implemented in the C sshnpd.