How to limit traffic from mobile internet in ubuntu?

Question

linux

Good afternoon!
Ubuntu laptop - How to block all mobile traffic except firefox? and unlock back at will?
on the second laptop I work from the mobile Internet and in order not to waste traffic on my Macbook, Little Snitch is installed in which you can block traffic for a specific program. What is the equivalent for ubuntu?
If there is no simple solution in Ubuntu, then advise what OS is better to put on a laptop to work on the road while saving battery and traffic?

Answer 1

If the issue is saving mobile traffic, then it is enough to download updates not automatically, but by an explicit command. The rest of the applications, if they will spend your mobile Internet, then no more than 100KB per day, which is comparable to downloading one page.
If the question is paranoia, then only hardcore: a tinfoil hat, the absence of mobile Internet and a laptop in principle.

Answer 2

Well, with the help of iptables, this task cannot be solved directly. But there is a cool idea.
1. We set a proxy, for example squid , it works under its own user (also squid).
2. Now, using iptables and the owner module, you can a) allow outside access for the squid user b) deny outside access for everyone else.
3. In your browser, set up work through a local proxy.

Answer 3

If you have mobile Internet on a phone that is connected to a laptop, then instead of setting up ethernet over usb (or whatever it is called), install any socks server on your smartphone (Google gives out some kind of socks server ultimate, try or install ssh server on your phone and connect via adb redirects with the -D1080 key) and use adb to set up tcp port forwarding.
Then register the received port in firefox and get a working Internet only in it.
ps I know for sure, some especially smart applications, skype used to do it a long time ago until microsoft destroyed it, teamviewer can also do it, .. study the settings in browser profiles in search of proxy settings