RPC wire format

Good day,

I would like to write some third-party tools (in Python most likely) to interact with a running Unity3D game (standalone Windows). I think one of the simplest solutions would be to use the RPC mechanism built into Unity3D.

Is the wire format for the RPC known, or based on some existing standards that I can program to?

Thank you,
Tyler

 

Excellent. Thank you for the link to the RakNet library. I browsed through it a bit, and it looks pretty reasonable.

So that I do not have to use a packet analyzer, can you tell me whether you use the AutoRPC or the RPC3 module? I am not yet sure if the wire format varies between these two, but if I could focus on studying just one of them, that would be a big help.

The other bit I would need to know is if there are any special ways that Unity uses the RakNet library. That is, are the uniqueIdentifiers for the RPC calls mangled in any way, etc.

Thank you,
Tyler

 

Updated information wrt my research on this. I downloaded the latest RakNet source (3.7 I think) for reference. That is, to see what the expected wire format is for the AutoRPC and RPC3 protocols.

I also created a very simple Unity3D 'server' and Unity3D 'client' and used the Networking built into Unity3D (Network.InitializeServer and the OnServerInitialized and OnPlayerConnected functions) to connect the client and server.

Using wireshark to capture all the network packets, I was able to see quite a bit of conversation when the client does a simple connection. The problem is that I could only align the first two packets: Connection Request and Connection Reply.

After those first two packets, I cannot match anything with the message types within RakNet. So I suspect that there is a bunch of Unity3D specific messaging going on.

So I am left with more questions that answers:

1. Is there a specific version of RakNet I ought to be looking at (a different message on the forum mentioned that perhaps 3.0 is what Unity 2.6.1 is using).

2. Is Unity3D using the AutoRPC or RPC3 functionality built into RakNet, or neither.

3. Is the Unity wire format compatible with the 'vanilla' RakNet? That is, do we expect that a standard RakNet client (C++, Python RakNet wrapper, etc.) can be compatible enough to call RPC functions in a Unity3D application?

Thank you,
Tyler