I'm working on a server (CentOS 7) that will be connected to a serial device service. I also have 6 client machines. The SDS makes the devices show as actual devices in linux and can be controlled by udev. However different users will be using these clients at random times. I need a way to assign users to the devices based on who's logged in so that no one can interfere with each others devices. Is there some way to assign a user a device while they're logged in and then free it up for reassigning when they log out? Or is there a way to make it so any user from a particular client always goes the same device on the server?