From 04c26b503ca88f47265416fe51f23f3b4a960b7d Mon Sep 17 00:00:00 2001
From: Elisha Riedlinger <elisha@novicemail.com>
Date: Fri, 26 Jan 2024 21:02:08 -0800
Subject: [PATCH] Hook GetDiskFreeSpaceA

---
 Dllmain/BuildNo.rc |  2 +-
 Utils/Utils.cpp    | 36 ++++++++++++++++++++++++++++++++++++
 Utils/Utils.h      |  2 ++
 ddraw/ddraw.cpp    |  2 ++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/Dllmain/BuildNo.rc b/Dllmain/BuildNo.rc
index 18d7bbf5..d82da207 100644
--- a/Dllmain/BuildNo.rc
+++ b/Dllmain/BuildNo.rc
@@ -1 +1 @@
-#define BUILD_NUMBER 6946 
+#define BUILD_NUMBER 6947 
diff --git a/Utils/Utils.cpp b/Utils/Utils.cpp
index 0f818fbc..e7082fbf 100644
--- a/Utils/Utils.cpp
+++ b/Utils/Utils.cpp
@@ -59,6 +59,7 @@ typedef DWORD(WINAPI* GetThreadIdProc)(HANDLE Thread);
 typedef FARPROC(WINAPI *GetProcAddressProc)(HMODULE, LPSTR);
 typedef DWORD(WINAPI *GetModuleFileNameAProc)(HMODULE, LPSTR, DWORD);
 typedef DWORD(WINAPI *GetModuleFileNameWProc)(HMODULE, LPWSTR, DWORD);
+typedef BOOL(WINAPI* GetDiskFreeSpaceAProc)(LPCSTR lpRootPathName, LPDWORD lpSectorsPerCluster, LPDWORD lpBytesPerSector, LPDWORD lpNumberOfFreeClusters, LPDWORD lpTotalNumberOfClusters);
 typedef BOOL(WINAPI *CreateProcessAFunc)(LPCSTR lpApplicationName, LPSTR lpCommandLine, LPSECURITY_ATTRIBUTES lpProcessAttributes, LPSECURITY_ATTRIBUTES lpThreadAttributes, BOOL bInheritHandles, DWORD dwCreationFlags,
 	LPVOID lpEnvironment, LPCSTR lpCurrentDirectory, LPSTARTUPINFOA lpStartupInfo, LPPROCESS_INFORMATION lpProcessInformation);
 typedef BOOL(WINAPI *CreateProcessWFunc)(LPCWSTR lpApplicationName, LPWSTR lpCommandLine, LPSECURITY_ATTRIBUTES lpProcessAttributes, LPSECURITY_ATTRIBUTES lpThreadAttributes, BOOL bInheritHandles, DWORD dwCreationFlags,
@@ -92,6 +93,7 @@ namespace Utils
 	INITIALIZE_OUT_WRAPPED_PROC(GetProcAddress, unused);
 	INITIALIZE_OUT_WRAPPED_PROC(GetModuleFileNameA, unused);
 	INITIALIZE_OUT_WRAPPED_PROC(GetModuleFileNameW, unused);
+	INITIALIZE_OUT_WRAPPED_PROC(GetDiskFreeSpaceA, unused);
 
 	FARPROC p_CreateProcessA = nullptr;
 	FARPROC p_CreateProcessW = nullptr;
@@ -334,6 +336,40 @@ DWORD WINAPI Utils::GetModuleFileNameWHandler(HMODULE hModule, LPWSTR lpFilename
 	return 0;
 }
 
+BOOL WINAPI Utils::kernel_GetDiskFreeSpaceA(LPCSTR lpRootPathName, LPDWORD lpSectorsPerCluster, LPDWORD lpBytesPerSector, LPDWORD lpNumberOfFreeClusters, LPDWORD lpTotalNumberOfClusters)
+{
+	Logging::LogDebug() << __FUNCTION__;
+
+	DEFINE_STATIC_PROC_ADDRESS(GetDiskFreeSpaceAProc, GetDiskFreeSpaceA, GetDiskFreeSpaceA_out);
+
+	if (!GetDiskFreeSpaceA)
+	{
+		return FALSE;
+	}
+
+	BOOL result = GetDiskFreeSpaceA(lpRootPathName, lpSectorsPerCluster, lpBytesPerSector, lpNumberOfFreeClusters, lpTotalNumberOfClusters);
+
+	// Limit the reported disk space
+	if (lpSectorsPerCluster)
+	{
+		*lpSectorsPerCluster = min(0x00000040, *lpSectorsPerCluster);
+	}
+	if (lpBytesPerSector)
+	{
+		*lpBytesPerSector = min(0x00000200, *lpBytesPerSector);
+	}
+	if (lpNumberOfFreeClusters)
+	{
+		*lpNumberOfFreeClusters = min(0x0000F000, *lpNumberOfFreeClusters);
+	}
+	if (lpTotalNumberOfClusters)
+	{
+		*lpTotalNumberOfClusters = min(0x0000FFF6, *lpTotalNumberOfClusters);
+	}
+
+	return result;
+}
+
 // Add HMODULE to vector
 void Utils::AddHandleToVector(HMODULE dll, const char *name)
 {
diff --git a/Utils/Utils.h b/Utils/Utils.h
index 13094050..74657c4e 100644
--- a/Utils/Utils.h
+++ b/Utils/Utils.h
@@ -12,6 +12,7 @@ namespace Utils
 	EXPORT_OUT_WRAPPED_PROC(GetProcAddress, unused);
 	EXPORT_OUT_WRAPPED_PROC(GetModuleFileNameA, unused);
 	EXPORT_OUT_WRAPPED_PROC(GetModuleFileNameW, unused);
+	EXPORT_OUT_WRAPPED_PROC(GetDiskFreeSpaceA, unused);
 
 	void Shell(const char*);
 	void DisableHighDPIScaling();
@@ -21,6 +22,7 @@ namespace Utils
 	FARPROC WINAPI GetProcAddressHandler(HMODULE hModule, LPSTR lpProcName);
 	DWORD WINAPI GetModuleFileNameAHandler(HMODULE hModule, LPSTR lpFilename, DWORD nSize);
 	DWORD WINAPI GetModuleFileNameWHandler(HMODULE hModule, LPWSTR lpFilename, DWORD nSize);
+	BOOL WINAPI kernel_GetDiskFreeSpaceA(LPCSTR lpRootPathName, LPDWORD lpSectorsPerCluster, LPDWORD lpBytesPerSector, LPDWORD lpNumberOfFreeClusters, LPDWORD lpTotalNumberOfClusters);
 	void HookExceptionHandler();
 	void UnHookExceptionHandler();
 	void AddHandleToVector(HMODULE dll, const char *name);
diff --git a/ddraw/ddraw.cpp b/ddraw/ddraw.cpp
index 7623197a..03198c52 100644
--- a/ddraw/ddraw.cpp
+++ b/ddraw/ddraw.cpp
@@ -25,6 +25,7 @@
 #include "Dllmain\Dllmain.h"
 #include "IClassFactory\IClassFactory.h"
 #include "d3d9\d3d9External.h"
+#include "Utils\Utils.h"
 #include "GDI\GDI.h"
 #include "External\Hooking\Hook.h"
 
@@ -70,6 +71,7 @@ void InitDDraw()
 		CreateWindowExW_out = (FARPROC)Hook::HotPatch(Hook::GetProcAddress(LoadLibrary("user32.dll"), "CreateWindowExW"), "CreateWindowExW", user_CreateWindowExW);
 		DestroyWindow_out = (FARPROC)Hook::HotPatch(Hook::GetProcAddress(LoadLibrary("user32.dll"), "DestroyWindow"), "DestroyWindow", user_DestroyWindow);
 		GetSystemMetrics_out = (FARPROC)Hook::HotPatch(Hook::GetProcAddress(LoadLibrary("user32.dll"), "GetSystemMetrics"), "GetSystemMetrics", user_GetSystemMetrics);
+		Utils::GetDiskFreeSpaceA_out = (FARPROC)Hook::HotPatch(Hook::GetProcAddress(LoadLibrary("kernel32.dll"), "GetDiskFreeSpaceA"), "GetDiskFreeSpaceA", Utils::kernel_GetDiskFreeSpaceA);
 		if (EnableWndProcHook)
 		{
 			SetWindowLongA_out = (FARPROC)Hook::HotPatch(Hook::GetProcAddress(LoadLibrary("user32.dll"), "SetWindowLongA"), "SetWindowLongA", user_SetWindowLongA);