Filter outgoing connections per program

General Help
1

Hi,
I am looking for a tool to control the outgoing connections of programs installed on my system.
For example, I use Little Snitch on macOS, which meets this need. It complements the OS's default firewall. With each attempt at an outgoing connection, you can choose the desired behavior: block or allow the connection, restrict it to a set of ports or IPs, choose the duration for applying the setting, etc.
For Linux, I have identified https://safing.io/ and https://github.com/evilsocket/opensnitch. Have any of you used these tools? Or do you have other alternatives?

2

there's also the builtin firewall in zorin that you can use.

3

It seems that the builtin firewall can not prompt the user, when an app/program try to connect to an external IP, to ask if the user allow or block the connection. That's what I want to do.
It this feasible?

4

Have you tried OpenSnitch?

5

Yes, I tried to install it; it was my second suggestion in the original post. It seems very interesting. But I can't get it to work. The GUI launch fails, despite the changes made according to the doc (Opensnitch no longer starts on my machine · Issue #1214 · evilsocket/opensnitch · GitHub).
Has anyone managed to get it to work (I'm on ZorinOS 17.2 Pro)?
I have only been able to test Portmaster (safing.io) so far.

6

Choose one,

https://www.facebook.com/photo/?fbid=4206858326261304&set=ecnf.100008115349487

7

The easiest way ChatGPT told me is as follows:

sudo apt update
sudo apt install ufw

sudo ufw enable

(status confiramation)
sudo ufw status verbose

(making effective after re-start)
sudo systemctl enable ufw

8

I managed to miss spotting that...

What method did you use to install it?
If you used PIP, please run:

sudo pip3 install --user --upgrade --force-reinstall opensnitch-ui

Ensure that the UFW itself is not blocking the thing:

sudo ufw allow 50050/tcp

Then launch using terminal with - watching for any errors listed in terminal:

opensnitch-ui

Or

opensnitch-ui --debug

9

Thank you @Aravisian

I downloaded the packages and install it with this command:
sudo apt install ./opensnitch*.deb ./python3-opensnitch-ui*.deb

But I get the following warning at the end:

invalid python3-grpcio version installed
Installed python3-grpcio package (1.30.2-3build6) has a bug which makes opensnitch UI unresponsive.

Last time I executed the command to resolve this with the admin user.
This time I run the commands with my regular user:
pip3 install grpcio==1.41.0
pip3 install protobuf==3.20.0

Now it works when launching opensnitch-ui.

I can now try both Portmaster and Opensnitch to learn how to configure them and see if one really meets my needs.

2 Likes
10

I've used Portmaster before and it generally does a pretty good work. Unfortunately, I did run into other issues that entirely severed internet access and couldn't be fixed without a full OS installation. Or to be more accurate, that was the easiest fix to the problem.

I haven't tried it in quite a while and I'm sure it has gotten better. Keep in mind though that Portmaster aims to be more than just a packet filter, so it'll naturally be more complex. I still have to try Opensnitch but it looks very promising.