C# + C++ Injection

[peterwurst]

Heya

I started to develop my program in pure C# with the managed_fasm library.
But while reading stuff and programming things I thought about writing the low level stuff in C++.

Now I'm a bit stuck and want to ask two questions:

1) I want to handle my stuff with EndScene detouring to my function.
First of all how do I find the "EndScene" offset through IDA, can't seem to find it.

2) After I inject my C++ .dll to WoW how do I call it functions with C#?
(Is there a way to check wether the function was called in process?)


Would a simple:

     [DllImport("MyLib")]
      static extern void Target(ulong guid);

be enough?

Thanks for your thoughts

[Shynd]

Do a google search on "Inter-process Communication." There are many ways of doing it: socket communication, named pipes, a shared memory region, etc. Using a named pipe is probably my favorite way of doing it, but it's entirely up to you.

[Cypher]

EndScene is a virtual function in a D3D device.

You have two choices, the easy, and the better:
Easy: Always make your loader launch WoW and hook D3DCreate9, from there you can hook CreateDevice, and from there you can hook EndScene.
Better: Create a custom device upon injection, pull out the EndScene function pointer from there, then discard it.

I say the former is easier because there's already copypaste code available. The latter isn't hard though, I got it working fairly quickly. I will probably be posting the class when I get time to finish cleaning it up.

[barthen]

You may want to take a look at the Wowsharp source code. They did what you want, inject a C++ dll and call its functions from C#.

[Cypher]

WoWSharp's implementation was pretty awful from memory. It was limited to a single instance because it used a shared segment in the DLL rather than something more robust like named pipes.

[Link_S]

2) After I inject my C++ .dll to WoW how do I call it functions with C#?
(Is there a way to check wether the function was called in process?)

Using COM Interopability you can call language to language.
C# in C++ - Through Dll
C++ in C# - Through Dll
VB in C++ - Through Dll

The only downside is that you have to register the path you're going to call your Dll from. Google COM Interop and I think you will find pretty useful threads and hints.