1 files changed, 51 insertions, 0 deletions
diff --git a/VmtHook.cpp b/VmtHook.cpp
new file mode 100644
index 0000000..915e82f
--- /dev/null
+++ b/VmtHook.cpp
@@ -0,0 +1,51 @@
+#include "VmtHook.h"
+
+
+
+VmtHook::VmtHook(void** vmt)
+{
+	this->vmt = vmt;
+}
+
+void* VmtHook::Hook(int index, void* hookedFunction)
+{
+	hookedfuncs.insert(std::make_pair(index, vmt[index]));
+
+	//make page writeable
+	DWORD pageProtection;
+	VirtualProtect(&vmt[index], sizeof(BYTE*), PAGE_EXECUTE_READWRITE, &pageProtection);
+
+	//overwrite function pointer in VMT to hook function
+	vmt[index] = hookedFunction;
+
+	//restore page protection
+	VirtualProtect(&vmt[index], sizeof(BYTE*), pageProtection, &pageProtection);
+
+	return hookedfuncs[index];
+}
+
+//
+//Unhook a single hooked function
+bool VmtHook::Unhook(int index)
+{
+	auto entry = hookedfuncs.find(index);
+	if (entry != hookedfuncs.end())
+	{
+		vmt[entry->first] = entry->second;
+		return true;
+	}
+	return false;
+}
+
+//
+//Unhook the entire Vmt
+void VmtHook::Unhook()
+{
+	for (std::pair<int, void*> pair : hookedfuncs)
+	{
+		DWORD oldProtection;
+		VirtualProtect(&vmt[pair.first], sizeof(BYTE*), PAGE_EXECUTE_READWRITE, &oldProtection);
+		vmt[pair.first] = pair.second;
+		VirtualProtect(&vmt[pair.first], sizeof(BYTE*), oldProtection, &oldProtection);
+	}
+}
+\ No newline at end of file