Socket.ReceiveFromAsync - Sender EndPoint doesn't work

Unity Engine
1

Hello,

For my next online game, I’m developing my network logic out of Unity (as the servers won’t be Unity-based and I want to re-use this work on non-Unity project). In my Visual Studio test project everything work perfectly, but I have a problem when calling my DLL from Unity :

private void ReceiveFunction(object sender, SocketAsyncEventArgs e)
{
	// UDP error -> Event
	if (e.SocketError != SocketError.Success || e.BytesTransferred == 0)
	{
		if (Server.Crash != null) Server.Crash(e);
		return;
	}

	// Client identification
	IPEndPoint Address = (IPEndPoint) e.RemoteEndPoint;
	Client Sender;
	lock (Server.Children)
	{
		if (Server.Children.ContainsKey(Address) == false)
		{
			// Keep track of the new client
			Server.Children.Add(Address, new Client());
		}
		Sender = Server.Children[Address];
	}

	// Read and answer the message
	Server.WorkOnThatMessage(Server.ReceiveBuffer, e.BytesTransferred, Sender);

	// Can receive more UDP message now
	e.RemoteEndPoint = new IPEndPoint(IPAddress.Any, 0);	// Receive from anyone
	if (Server.Socket.ReceiveFromAsync(e) == false)
	{
		Server.ReceiveFunction(null, e);	//In case of synchronous completion
	}
}

When using Socket.ReceiveFromAsync in Unity, SocketAsyncEventArgs.RemoteEndPoint return “0.0.0.0:0” (IPAddress.Any) instead of the sender’s address. This is really problematic as I have no other mean of getting this information, and thus can’t answer any client’s request.

Socket.ReceiveAsync (TCP communication) work fine in Unity …
Socket.BeginReceive (with “ref EndPoint”) work fine in Unity too …
… but I really want to avoid using TCP (the game will be a First Person Shooter and TCP will be too slow) or the Begin/EndReceive methods (as they create a lot of work for the garbage collector).

Thanks for your help.

2

You cant use SocketAsyncEventArgs in Unity, the API is there but it doesn’t work properly.

3

Urgh …
That’s a really bad new. Do you know if the Unity team is working on it ?

Thanks for the fast answer anyway.

4

Not sure if they’ve released a patch to fix this recently but it works now if you change the ‘API compatability level’ to .NET 2.0 from .NET 2.0 subset in player settings.

Spent about a month coding a server using saea so I’m thrilled it was fixed…