[kwlug-disc] Question about ... sockets?

[Mikalai Birukou]

A need/want:

I want process to start some other process, giving it some way to 
communicate with creator process. This communication should be only 
between these two running processes, i.e. kernel help us here.


My currently limited understanding:

  - Everyone do something that sounds precisely like this, e.g. 
communication between Electron main and renderrer processes. It feels, 
that I am missing some fundamental understanding here.

  - When you grew out of user land, you encounter suggestions like 
socket on localhost:port and unix socket on some path. Localhost:port is 
not ok, cause everyone on the machine can connect. Unix socket has 
protection on path with privileges. But I want a connection between two 
specific processes only. In fact, if connection is dropped, created 
process should close as well. Hacking thought within this limited choice 
is make a path, start to listen, when created process connects, unlink 
that path. But can I pass an open connection, and only it?

  - How should process be started so that it isn't given implicitly any 
resources from initializing process, only passing explicitly particular 
open connection(s)? I head fork is making copies of descriptors :/ ? Is 
there other way? Can someone explain this, or give links to 
userland-parsable resources/docs?


Thank you.