Guide CS: Source — Debugging CreateMove Hook with MinHook

[byte_corvus]

Dealing with the Source engine’s client.dll can be a headache if your offsets are even a byte off. You're trying to detour CreateMove using MinHook, but if the console isn't spitting out command numbers, your hook likely never placed or you're pointing at the wrong address.

The Technical Breakdown

In your snippet, you're using hardcoded offsets:

#define g_clientmode (uintptr_t)(GetModuleHandleA("client.dll")) + 0x69CFE8
#define CreateMoveAddr (uintptr_t)(GetModuleHandleA("client.dll")) + 0xF5290

Hardcoding offsets like this is the fastest way to break a project. Every time the game updates — even a minor steam overlay or security patch — those addresses shift. Beyond that, hooking CreateMove via a direct detour at a fixed offset is generally less stable than using VTable hooking on the IClientMode or CHLClient interfaces.

Common Points of Failure

1. Check MinHook Status: You aren't checking the return values of MH_Initialize or MH_CreateHook. If CreateMoveAddr is invalid, MH_CreateHook will return an error code. Wrap those in a simple check to see if it's actually succeeding.
2. Calling Convention: You're using __fastcall. In the Source engine, many CreateMove implementations (especially on IClientMode) expect specific stack handling. If the signature doesn't match the engine's expectation for your specific version of CSS, you'll BSOD or CTD instantly.
3. Pointer Validation: You are passing g_clientmode to the original function, but you're calculating it as a static offset. If that pointer is null or hasn't been initialized by the engine when your DllMain fires, the game will crash the moment it tries to call the original function.

Spoiler: Technical Advice

Instead of hunting offsets like it's 2012, use the game's exported CreateInterface function. Find the "VClient017" (or whatever version CSS is currently on) interface in client.dll, then get the pointer to IClientMode. It’s much more robust than static offset scanning.

Preventive Troubleshooting

If you're sticking with MinHook, make sure you're compiling for the correct architecture (x86 for CSS). Also, DisableThreadLibraryCalls is fine, but ensure your MainThread isn't being nuked by an anti-cheat heartbeat if you're testing on secured servers. Always test with -insecure in launch options to avoid an immediate VAC flag while debugging hooks.

Any of you guys still running static offsets for Source games, or have you all moved to signature scanning and interface regs?