tun2proxy

Tunnel TCP traffic through SOCKS5 or HTTP on Linux.

Error handling incomplete and too restrictive.

Build

Clone the repository and cd into the project folder. Then run the following:

cargo build --release

Setup

A standard setup, which would route all traffic from your system through the tunnel interface, could look as follows:

# The proxy type can be either SOCKS5 or HTTP.
PROXY_TYPE=SOCKS5
PROXY_IP=1.2.3.4
PROXY_PORT=1080

# Create a tunnel interface named tun0 which your user can bind to,
# so we don't need to run tun2proxy as root.
sudo ip tuntap add name tun0 mode tun user $USER
sudo ip link set tun0 up

# To prevent a routing loop, we add a route to the proxy server that behaves
# like the default route.
sudo ip route add "$PROXY_IP" $(ip route | grep '^default' | cut -d ' ' -f 2-)

# Route all your traffic through tun0 without interfering with the default route.
sudo ip route add 128.0.0.0/1 dev tun0
sudo ip route add 0.0.0.0/1 dev tun0

./target/release/tun2proxy --tun tun0 --proxy "$PROXY_TYPE://$PROXY_IP:$PROXY_PORT"

Note that if you paste these commands into a shell script, which you then run with sudo, you might want to replace $USER with $SUDO_USER.

For DNS to work, you might need an additional tool like dnsproxy that is configured to listen on a local UDP port and communicates with the upstream DNS server via TCP.

When you terminate this program and want to eliminate the impact caused by the above several commands, you can execute the following command. The routes will be automatically deleted with the tunnel device.

sudo ip link del tun0

CLI

Tunnel interface to proxy.

Usage: tun2proxy [OPTIONS] --proxy <URL>

Options:
  -t, --tun <name>   Name of the tun interface [default: tun0]
  -p, --proxy <URL>  The proxy URL in the form proto://[username[:password]@]host:port
  -h, --help         Print help
  -V, --version      Print version

Currently, tun2proxy supports two proxy protocols: HTTP and SOCKS5. A proxy is supplied to the --proxy argument in the URL format. For example, an HTTP proxy at 1.2.3.4:3128 with a username of john.doe and a password of secret is supplied as --proxy http://john.doe:secret@1.2.3.4:3128. This works analogously to curl's --proxy argument.

TODO

• UDP support for SOCKS
• Virtual DNS