Initial commit

1 files changed, 67 insertions, 0 deletions

diff --git a/source2-basehook/Utilities/VMTHook.hpp b/source2-basehook/Utilities/VMTHook.hpp
new file mode 100644
index 0000000..b25b2af
--- /dev/null
+++ b/source2-basehook/Utilities/VMTHook.hpp
@@ -0,0 +1,67 @@
+#pragma once
+#include "../Include.hpp"
+
+class VMTHook
+{
+public:
+	explicit VMTHook(void* ptr)
+	{
+		if (!ptr)
+			return;
+
+		pClass = reinterpret_cast<uintptr_t**>(ptr);
+		pOriginalVMT = *pClass;
+
+		const auto Size = Length();
+		pHookedVMT = std::make_unique<uint64_t[]>(Size + 1);
+
+		memcpy(&pHookedVMT.get()[1], pOriginalVMT, Size * sizeof uint64_t);
+
+		pHookedVMT.get()[0] = static_cast<uintptr_t>(pOriginalVMT[-1]);
+
+		PatchPtr(pHookedVMT.get());
+	}
+
+	~VMTHook()
+	{
+		PatchPtr(pOriginalVMT);
+	}
+
+	template<typename Function, typename Original>
+	Function HookFunction(uint64_t Index, Original _Function)
+	{
+		auto Old = pOriginalVMT[Index];
+		pHookedVMT.get()[Index + 1] = reinterpret_cast<uintptr_t>(_Function);
+		return reinterpret_cast<Function>(Old);
+	}
+
+private:
+
+	uint64_t Length() 
+	{
+		uint64_t Index = 0;
+		const auto VMT = pOriginalVMT;
+
+		for (Index = 0; VMT[Index]; Index++)
+			if (IS_INTRESOURCE(VMT[Index]))
+				break;
+
+		return Index;
+	}
+
+	void PatchPtr(uintptr_t* Replacement)
+	{
+		if (!pClass)
+			return;
+
+		DWORD Old;
+
+		VirtualProtect(pClass, sizeof uintptr_t, PAGE_READWRITE, &Old);
+		Replacement == pOriginalVMT ? *pClass = Replacement : *pClass = &Replacement[1];
+		VirtualProtect(pClass, sizeof uintptr_t, Old, &Old);
+	}
+
+	std::uintptr_t** pClass;
+	std::uintptr_t* pOriginalVMT;
+	std::unique_ptr<uint64_t[]> pHookedVMT;
+};
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