'IPC' between dropbear master and child processes

[Michael Wiedmann]

Hi,

I'm evaluating to use 'dropbear' as an SSH server (on Cygwin) for the following scenario:

Embedded devices contact the central dropbear server as clients requesting 'remote port forwarding' for two local ports (23 and 80) which are used to configure the embedded devices.

This works in general very well.

I need visualize all ssh connections in a Web application to let the 'admin' monitor/control them. Therefore I need some kind of list of all connections in the 'master' process. This list can be provided to the Web application (.NET) using some IPC  system (still has to be determined).

Now I'm looking for the easiest way to communicate from the forked child processes to the master process. The information needed from the child processes are mainly the chosen forwarded ports and the remote IP address (to be able to display a link in the web browser for any given embedded device).

I've seen the 'childpipes' but I'm not sure what are they used for. 

Can I use the 'childpipe' (which is passed to 'svr_session(...)' as an argument and stored in the 'struct serversession') to write back to the master server process
(I've seen the comment 'kept open until we successfully authenticate' in 'session.h')?

Another solution would be to use Unix domain sockets as IPC between the processes.

Any hints/remarks would be highly appreciated.

Cheers
Michael