Welcome to the Forum.
What Linux are you using?
FreeCAD is is a full CAD/CAM program that runs on Linux. Requires to watch a few video tutorials to get started.
Makercam can also be run local, the link and tip to get it work are here Advice for Metric use of MakerCam, still flash has to be installed AND enabled:
https://helpx.adobe.com/flash-player/kb/flash-player-chromium.html