As a side project I wish to modify an existing open source VNC application and modify it to attempt to initiate a reverse connection from the server (that the users have) to the single client that I will control. This will allow me to easily send out a single executable to friends and loved ones and when they run it, their vnc server will connect with me and I can help them fix their computer without messing with firewall settings or port forwarding.
In essence, I want to do a poor-mans Copilot. Except, instead of an intermediary server in between the helper and the helpee, I just want the helpee's server to attempt to repeatedly connect to the helper (therefore bypassing any firewalls/routers) in between the two. Obviously, the helper's client will be exposed to the internet.
Does anyone have any information or resources concerning writing a reverse-connection app and the act of tunneling traffic from the helpee to the helper? Will I be employing some form of ssh tunneling or some other form of tunneling? What about the code structure involved in having all the helpees (servers) attempting to connect to the helper (client) at a certain interval? Can you point me to any open source revese connection apps?
Any resources or tips are appreciated. I don't have a significant amount of network programming experience and this seems like it would be a fun project. I'm not looking for a commercial product.. I'm doing this for fun and experience.