Proxy-NS — Linux App Proxifier

Dependencies

• tun2socks
• nsenter

How does it work?

app-proxifier.sh creates a new network namespace and starts tun2socks inside it.

It then:

• Connects this namespace to the host using a veth pair
• Routes all tun2socks traffic to your SOCKS5 proxy running in the host namespace

Setup

You can either:

• Manually configure app-proxifier.sh
  or
• Use environment variables

Environment Variables

# Your username
USER="USER"

# Path to tun2socks
TUN2SOCKS="/opt/tun2socks/tun2socks"

# Your SOCKS5 proxy port
SOCKS_PORT="1080"

• Optionally run it as a systemd service

⚠️ MAKE SURE YOUR SOCKS PROXY LISTENS ON 0.0.0.0 OR INCLUDES THE VETH PAIR ADDRESS ⚠️

Running an App Through the Proxy

Lazy way:

sudo -E nsenter --net=/run/netns/proxy sudo -Eu USERNAME EXECUTABLE

I’ve added a simple bash script for running Discord.
You can use that as an example for your own app and optionally save it in your $PATH for easier access.

Notes

• Using nested sudo is not good practice. You can implement your own method — just make sure:

  • The correct environment variables are passed
  • Privileges are properly dropped/elevated where needed

• This method does not work with .desktop files. Terminal only.

• Rootless namespaces might be better suited for this purpose.
  Maybe I’ll look into them in the future.