Zero dependency, small footprint, cross-platform I2P Java Router with simple tunnel controller and SAM interface

This project will run under Linux, and build native launchers for Linux, MacOS and Windows. The launchers will include the I2P router, a SAM listener and a minimal JVM.

Footprint

The zero-dependency distribution sizes are as follows:

OS	Uncompressed size (MB)	xz Compressed size (MB)
Linux	41.6	22.5
MacOS	29.5	17.5
Windows	33.6	20.1

Building the launchers

From a freshly installed Ubuntu system, first ensure git is installed:

sudo apt install git

Then, retrieve this project from git:

git clone https://github.com/knaccc/i2p-zero.git

Note that the current version of this script uses jdk-11.0.2. If this version of Java becomes no longer available for download, then update the references to jdk-11.0.2 in java-config.sh to the later version. To locate a recent JDK download URL, see https://jdk.java.net/11/

Also note that JDKs for Linux, MacOS and Windows will be downloaded, which will total several hundred megabytes.

Run the bin/build-all.sh script, which will in turn call the following scripts:

1. bin/import-packages.sh to retrieve the I2P Java sources, OpenJDK and the Ant build tool

2. bin/build-original-i2p.sh to build the I2P project retrieved from the I2P repository

3. build-launcher.sh to convert the I2P JARs to modules, compile the Java source code in this project, and then use the jlink tool to build zero-dependency platform-specific launchers.

Running the launchers

To run the Linux router, type:

dist/linux/router/bin/launch.sh

To run the MacOS router, type:

dist/mac/router/bin/launch.sh

For Windows, run:

dist/windows/router/bin/launch.bat

If it launches successfully, you'll see the message:

I2P router launched. SAM listening on port 7656.
Press Ctrl-C to gracefully shut down the router (or send the SIGINT signal to the process).

Check that the I2P router is running and that it is listening for SAM connections

fuser 7656/tcp

Tunnel control

Listen for i2p connections and forward them to the specified host and port. Returns a newly created destination public key.

dist/linux/router/bin/tunnel-control.sh server.create <host> <port>

Close the tunnel listening for connections on the specified port. Returns "OK".

dist/linux/router/bin/tunnel-control.sh server.destroy <i2p destination public key>

Create a tunnel that listens for connections on localhost and forwards connections over I2P to the specified destination public key. Returns a newly created localhost port number.

dist/linux/router/bin/tunnel-control.sh client.create <i2p destination public key>

Close the tunnel listening for connections on the specified port. Returns "OK".

dist/linux/router/bin/tunnel-control.sh client.destroy <port>

Create a socks tunnel, listening on the specified port

dist/linux/router/bin/tunnel-control.sh socks.create <port>

Destroy the socks tunnel listening on the specified port

dist/linux/router/bin/tunnel-control.sh socks.destroy <port>

Watch the I2P log for messages

tail -f dist/linux/router/i2p.config/wrapper.log