Portable Windows DLL stub generator. Currently supports Windows and Linux.

Inspired by https://www.codeproject.com/Articles/16541/Create-your-Proxy-DLLs-automatically (mainly the jump table method).

Installing (Linux)

git clone https://github.com/Francesco149/stubgen.git
cd stubgen
./build.sh

# I personally prefer to symlink it or have a local bin folder in
# my home directory, but this is the easiest way
sudo cp stubgen /usr/bin

Installing (Windows)

I'm gonna assume you already have visual studio installed, but if you don't you will need at least the compiler so install Visual C++ Build Tools 2015 or any other version: http://landinghub.visualstudio.com/visual-cpp-build-tools

Install git bash and

git clone https://github.com/Francesco149/stubgen.git

Open a visual studio command prompt and

cd C:\path\to\stubgen
build.bat

Now you can copy stubgen.exe to anywhere your system can find it, such as C:\Windows\System32 or SysWOW64 or simply add stubgen's path to your PATH by running the following in an administrator command prompt:

setx PATH "%PATH%;C:\path\to\stubgen" /M

Usage

Generating a stub:

mkdir mystub
cd mystub
stubgen /path/to/original.dll

You can now edit dllmain.c and trampolines.asm to hook functions as you please.

Run stubgen with no arguments to see a full documentation of all the available flags and parameters.

Here is a full example of a project generated with stubgen that hook a couple OpenGL functions: https://github.com/Francesco149/stubgen/tree/master/example

To hook a function, remove it from trampolines.asm and define it with the same name (if you change the name you will have to update exports.def) and and its proper signature in dllmain.c.

You can call the original functions by getting their pointers from hdll or more simply, casting the relevant pointer from the original_funcs array to the correct signature.

Don't forget to call wait_init() at the beginning of every hook, this will wait for the original_funcs table to be initialized.

You can also have stubgen use inline asm to have all the code in dllmain.c. While this makes editing easier, this only works for 32-bit DLLs (because msvc doesn't have x64 inline asm) and therefore isn't recommended. Pass the flag i to enable this.

Once you're done, you can compile from a visual studio prompt by running build.bat or build.bat 64 for 64-bit, just make sure the target architecture of the visual studio prompt is the desired one.

Why make it portable when it's a Windows-specific tool?

I run linux as my daily driver and I occasionally need to develop hacks or mods for windows stuff. Since I have a working VS2010 install running under wine, I can compile and work with windows code entirely from linux.

I didn't like running other stub generators (which are windows only) under wine, so I decided to make my own. This was quickly put together in a day or so, code quality might not be the best.

License

This code is public domain and comes with no warranty. You are free to do whatever you want with it. You can contact me at lolisamurai@tfwno.gf but don't expect any support.

I hope you will find the code useful or at least interesting to read. Have fun!