zhangyang-libzt/docs/unity3d_osx_zt_sdk.md

Unity3D OSX + ZeroTier SDK

Welcome!

We want your Unity apps to talk directly over a flat, secure, no-config virtual network without sending everything into the "cloud". Thus, we introduce the ZeroTier-Unity3D integration!

Our implementation currently intends to be the bare minimum required to get your Unity application to talk over ZeroTier virtual networks. As a result, we've created an API that is very similar to the classic BSD-style sockets API. With this basic API it is possible to construct more abstracted network layers much like Unity's LLAPI and HLAPI.

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API

• Join(nwid): Joins a ZeroTier virtual network
• Leave(nwid): Leaves a ZeroTier virtual network
• Socket(family, type, protocol): Creates a ZeroTier-administered socket
• Bind(fd, addr, port): Binds to that socket on the address and port given
• Listen(fd, backlog): Puts a socket into a listening state
• Accept(fd): Accepts an incoming connection
• Connect(fd, addr, port): Connects to an endpoint associated with the given fd
• Write(fd, buf, len): Sends data to the endpoint associated with the given fd
• Read(fd, buf, len): Receives data from an endpoint associated with the given fd
• CLose(fd): Closes a connection with an endpoint

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Adding ZeroTier to your Unity app

Step 1: Create virtual ZeroTier virtual network

Step 2: Add plugin to Unity project

• Create folder Assets/Plugins
• Place ZeroTierSDK_Unity3D_OSX.bundle in folder

Step 3: Include wrapper class source

• Drag ZeroTierNetworkInterface.cs into your Assets folder.

Step 4: Create and use a ZeroTierNetworkInterface object

• See examples below for how to use it!

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Examples

Start by creating a ZeroTierNetworkInterface object and calling Calling ZeroTier.Init() will start the network service in a separate thread. You can check if the service is running by checking ZeroTier.IsRunning(). Then, connecting and sending data to another endpoint would look something like the following:

Using ZeroTier Sockets API

Server example

public class Example
{
	public ZeroTierNetworkInterface zt;

	public void example_server()
	{
		Thread connectThread = new Thread(() => { 
			// Create ZeroTier-administered socket
			int sock = zt.Socket ((int)AddressFamily.InterNetwork, (int)SocketType.Stream, (int)ProtocolType.Unspecified);
			zt.Bind(sock, "0.0.0.0", 8000);
			zt.Listen(sock, 1);

			// Accept() client connection
			int accept_sock = -1;
			while(accept_res < 0) {
				accept_sock = zt.Accept(sock);
			}

			// Read data from client
			char[] msg = new char[1024];
			int bytes_read = 0;
			while(bytes_read >= 0) { 
				bytes_read = zt.Read(accept_sock, ref msg, 80);
				string msgstr = new string(msg);
				Debug.Log("MSG (" + bytes_read + "):" + msgstr);
			}
		});
		connectThread.IsBackground = true;
		connectThread.Start();
	}
}

Client example

public class Example
{
	public ZeroTierNetworkInterface zt;

	public void example_client()
	{
		Thread connectThread = new Thread(() => {	
			// Create ZeroTier-administered socket		
			int sock = zt.Socket ((int)AddressFamily.InterNetwork, (int)SocketType.Stream, (int)ProtocolType.Unspecified);
			zt.Connect (sock, "0.0.0.0",8000);
			zt.Write(sock, "Welcome to the machine!", 24);
		});
		connectThread.IsBackground = true;
		connectThread.Start();
	}
}

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Design and structure of the ZeroTier Unity OSX Bundle

XCode: New XCode project Select Cocoa bundle as target Add C linkages to external functions Build as 64bit (not universal)

Unity: Select x86_64 build target in Build Settings In new C# script asset:

[DllImport ("ZeroTierUnity")]
private static extern int unity_start_service ();

Add asset to GameObject Start ZT service

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Future Roadmap

With the ZeroTier sockets API in place, higher-level functionality such as lobbies, chat, and object synchronization could easily be built on top.