CoopAllTheThings/hook/src/dllmain.cpp

// coop_hook.dll -- injected into the target game by the host.
//
// On load it opens the host's shared-memory channel (named by this process's
// pid), hooks XInput so the game reads the forwarded controller state, and
// spoofs focus so the game keeps running while the tool holds the real OS focus.
// All real work happens on a worker thread; DllMain only kicks it off to stay
// clear of the loader lock.

#include <atomic>

#include <windows.h>

#include <objbase.h>

#include "audio_hook.hpp"
#include "coop/audio_ring.hpp"
#include "coop/shared_memory.hpp"
#include "debug_log.hpp"
#include "focus_spoof.hpp"
#include "ipc_client.hpp"
#include "xinput_hook.hpp"

namespace
{

coop::hook::IpcClient g_ipc;
std::atomic<bool> g_running{true};
coop::SharedMemory g_audio_shm; // the host's audio ring, opened when present

DWORD WINAPI worker_thread(LPVOID)
{
	coop::hook::logf("worker_thread: started");

	// The host creates the mapping around injection time; give it a few seconds.
	if (!g_ipc.connect(/*attempts=*/200, /*delay_ms=*/25))
	{
		coop::hook::logf("worker_thread: IPC connect FAILED (no host mapping); exiting");
		return 0;
	}
	coop::hook::logf("worker_thread: IPC connected");

	// The audio render-hook instantiates a COM enumerator on this thread.
	const bool com_ok = SUCCEEDED(CoInitializeEx(nullptr, COINIT_MULTITHREADED));
	coop::hook::logf("worker_thread: CoInitializeEx com_ok=%d", com_ok ? 1 : 0);

	bool xinput_installed = false;
	bool focus_installed = false;
	bool audio_installed = false;
	bool audio_ring_open = false;

	// Keep retrying the installs (XInput and the game window may both appear
	// lazily) and beat a heartbeat so the host can show the hook is alive.
	while (g_running.load(std::memory_order_relaxed))
	{
		if (!xinput_installed)
		{
			xinput_installed = coop::hook::install_xinput_hooks(g_ipc);
		}
		if (!focus_installed)
		{
			focus_installed = coop::hook::install_focus_spoof(g_ipc);
		}
		// Install the audio render-hook even before the host's ring exists, so
		// render streams are counted for the debug view regardless; attach the
		// ring (enabling capture+silence) once the host creates it.
		if (com_ok && !audio_installed)
		{
			audio_installed = coop::hook::install_audio_hooks(g_ipc, nullptr);
			if (audio_installed)
			{
				coop::hook::logf("worker_thread: audio hooks installed");
			}
		}
		if (audio_installed && !audio_ring_open)
		{
			const std::wstring name = coop::audio_ring_name(GetCurrentProcessId());
			if (g_audio_shm.open(name, coop::audio_ring_total_size(coop::kAudioRingCapacity)))
			{
				auto* ring = g_audio_shm.as<coop::AudioRingHeader>();
				if (coop::audio_ring_valid(*ring))
				{
					coop::hook::set_audio_ring(ring);
					audio_ring_open = true;
					coop::hook::logf("worker_thread: audio ring opened");
				}
				else
				{
					g_audio_shm.reset(); // present but not our contract; retry
				}
			}
		}
		coop::hook::update_input_diagnostics(g_ipc); // refreshes each tick; registrations can change
		g_ipc.heartbeat();
		Sleep(250);
	}

	if (com_ok)
	{
		CoUninitialize();
	}
	return 0;
}

} // namespace

BOOL APIENTRY DllMain(HMODULE module, DWORD reason, LPVOID reserved)
{
	switch (reason)
	{
	case DLL_PROCESS_ATTACH:
		DisableThreadLibraryCalls(module);
		if (HANDLE thread = CreateThread(nullptr, 0, &worker_thread, nullptr, 0, nullptr))
		{
			CloseHandle(thread);
		}
		break;
	case DLL_PROCESS_DETACH:
		// Skip cleanup when the process is tearing down (reserved != null): the
		// loader is already unwinding and touching other modules is unsafe.
		if (reserved == nullptr)
		{
			g_running.store(false, std::memory_order_relaxed);
			coop::hook::remove_focus_spoof();
			coop::hook::remove_xinput_hooks();
			coop::hook::remove_audio_hooks();
		}
		break;
	default:
		break;
	}
	return TRUE;
}