Forwarding calls to functions with the same name in multiple DLLs

[lowleveldesign]

I want to hook the DllGetClassObject and DllCanUnloadNow functions in the "COM" DLLs loaded by a given process. I already hooked LoadLibrary* functions, but I have difficulties creating DllGetClassObject hooks dynamically. The problem is that I want to call the original function in my hook function (let's call it myDllGetClassObject). As the myDllGetClassObject body is the same for all the created hooks, I need to find a way to pick the correct function to which I will forward the call.

The only idea that comes to my mind is to find the return address of myDllGetClassObject and move backward to find the trampoline address. The trampoline address uniquely identifies a given hook and will allow me to do the call. But it seems a bit complicated, and I'm not sure if it's portable between platforms. Could you please advise if there is maybe a better way?

[Dwedit]

Don't use the same replacement function for multiple different functions, then you won't have that problem.