Feat/vmt hook (#34)

* Refactor: Replace uintptr_t addresses with uint8_t*
This fixes instances where unsigned integer overflow could occur when calculating new displacements and uint8_t*'s are generally just easier to work with.

* Fix: Improve memory store safety by avoiding unaligned stores

* VmtHook: Initial unittest concept

* VmtHook: Start stubbing out the implementation

* VmtHook: Initial MVP

* VmtHook: Use a concept for function pointers
NOTE: 32-bit MSVC doesn't like static __thiscall function pointers

* VmtHook: Maintain RTTI information when hooked

* VmtHook: Have hooks inherit from their targets

* VmtHook: Use a shared Allocation to improve safety

* VmtHook: Add apply & remove to hook/unhook other object instances

* VmtHook: Improve virtual method counting

* Utility: Add is_executable utility to replace IsBadCodePtr

* VmtHook: Add easy API for hooking methods

* VmtHook: Add documentation

CMakeLists.txt

@@ -93,6 +93,8 @@ set(safetyhook_SOURCES
 	"src/inline_hook.cpp"
 	"src/mid_hook.cpp"
 	"src/thread_freezer.cpp"
+	"src/utility.cpp"
+	"src/vmt_hook.cpp"
 	cmake.toml
 )
 
@@ -489,6 +491,7 @@ if(SAFETYHOOK_BUILD_TESTS) # build-tests
 		"unittest/inline_hook.cpp"
 		"unittest/inline_hook.x86_64.cpp"
 		"unittest/mid_hook.cpp"
+		"unittest/vmt_hook.cpp"
 		cmake.toml
 	)
 
@@ -557,6 +560,7 @@ if(SAFETYHOOK_BUILD_TESTS) # build-tests
 			"unittest/inline_hook.cpp"
 			"unittest/inline_hook.x86_64.cpp"
 			"unittest/mid_hook.cpp"
+			"unittest/vmt_hook.cpp"
 			"amalgamated-dist/safetyhook.cpp"
 			cmake.toml
 		)

include/safetyhook.hpp

@@ -4,9 +4,12 @@
 #include <safetyhook/inline_hook.hpp>
 #include <safetyhook/mid_hook.hpp>
 #include <safetyhook/thread_freezer.hpp>
+#include <safetyhook/vmt_hook.hpp>
 
 using SafetyHookContext = safetyhook::Context;
 using SafetyHookInline = safetyhook::InlineHook;
 using SafetyHookMid = safetyhook::MidHook;
 using SafetyInlineHook [[deprecated("Use SafetyHookInline instead.")]] = safetyhook::InlineHook;
 using SafetyMidHook [[deprecated("Use SafetyHookMid instead.")]] = safetyhook::MidHook;
+using SafetyHookVmt = safetyhook::VmtHook;
+using SafetyHookVm = safetyhook::VmHook;

include/safetyhook/allocator.hpp

@@ -124,4 +124,4 @@ class Allocator final : public std::enable_shared_from_this<Allocator> {
     [[nodiscard]] static bool in_range(
         uint8_t* address, const std::vector<uint8_t*>& desired_addresses, size_t max_distance);
 };
-} // namespace safetyhook
+} // namespace safetyhook

include/safetyhook/easy.hpp

@@ -5,6 +5,8 @@
 
 #include <safetyhook/inline_hook.hpp>
 #include <safetyhook/mid_hook.hpp>
+#include <safetyhook/utility.hpp>
+#include <safetyhook/vmt_hook.hpp>
 
 namespace safetyhook {
 /// @brief Easy to use API for creating an InlineHook.
@@ -14,13 +16,10 @@ namespace safetyhook {
 [[nodiscard]] InlineHook create_inline(void* target, void* destination);
 
 /// @brief Easy to use API for creating an InlineHook.
-/// @tparam T The type of the function to hook.
 /// @param target The address of the function to hook.
 /// @param destination The address of the destination function.
 /// @return The InlineHook object.
-template <typename T>
-    requires std::is_function_v<T>
-[[nodiscard]] InlineHook create_inline(T* target, T* destination) {
+[[nodiscard]] InlineHook create_inline(FnPtr auto target, FnPtr auto destination) {
     return create_inline(reinterpret_cast<void*>(target), reinterpret_cast<void*>(destination));
 }
 
@@ -31,13 +30,29 @@ template <typename T>
 [[nodiscard]] MidHook create_mid(void* target, MidHookFn destination);
 
 /// @brief Easy to use API for creating a MidHook.
-/// @tparam T The type of the function to hook.
 /// @param target the address of the function to hook.
 /// @param destination The destination function.
 /// @return The MidHook object.
-template <typename T>
-    requires std::is_function_v<T>
-[[nodiscard]] MidHook create_mid(T* target, MidHookFn destination) {
+[[nodiscard]] MidHook create_mid(FnPtr auto target, MidHookFn destination) {
     return create_mid(reinterpret_cast<void*>(target), destination);
 }
+
+/// @brief Easy to use API for creating a VmtHook.
+/// @param object The object to hook.
+/// @return The VmtHook object.
+[[nodiscard]] VmtHook create_vmt(void* object);
+
+/// @brief Easy to use API for creating a VmHook.
+/// @param vmt The VmtHook to use to create the VmHook.
+/// @param index The index of the method to hook.
+/// @param destination The destination function.
+/// @return The VmHook object.
+[[nodiscard]] VmHook create_vm(VmtHook& vmt, size_t index, FnPtr auto destination) {
+    if (auto hook = vmt.hook_method(index, destination)) {
+        return std::move(*hook);
+    } else {
+        return {};
+    }
+}
+
 } // namespace safetyhook

include/safetyhook/inline_hook.hpp

@@ -11,6 +11,7 @@
 #include <vector>
 
 #include <safetyhook/allocator.hpp>
+#include <safetyhook/utility.hpp>
 
 namespace safetyhook {
 /// @brief An inline hook.
@@ -78,15 +79,12 @@ class InlineHook final {
     [[nodiscard]] static std::expected<InlineHook, Error> create(void* target, void* destination);
 
     /// @brief Create an inline hook.
-    /// @tparam T The type of the function to hook.
     /// @param target The address of the function to hook.
     /// @param destination The destination address.
     /// @return The InlineHook or an InlineHook::Error if an error occurred.
     /// @note This will use the default global Allocator.
     /// @note If you don't care about error handling, use the easy API (safetyhook::create_inline).
-    template <typename T>
-        requires std::is_function_v<T>
-    [[nodiscard]] static std::expected<InlineHook, Error> create(T* target, T* destination) {
+    [[nodiscard]] static std::expected<InlineHook, Error> create(FnPtr auto target, FnPtr auto destination) {
         return create(reinterpret_cast<void*>(target), reinterpret_cast<void*>(destination));
     }
 
@@ -100,16 +98,13 @@ class InlineHook final {
         const std::shared_ptr<Allocator>& allocator, void* target, void* destination);
 
     /// @brief Create an inline hook with a given Allocator.
-    /// @tparam T The type of the function to hook.
     /// @param allocator The allocator to use.
     /// @param target The address of the function to hook.
     /// @param destination The destination address.
     /// @return The InlineHook or an InlineHook::Error if an error occurred.
     /// @note If you don't care about error handling, use the easy API (safetyhook::create_inline).
-    template <typename T>
-        requires std::is_function_v<T>
     [[nodiscard]] static std::expected<InlineHook, Error> create(
-        const std::shared_ptr<Allocator>& allocator, T* target, T* destination) {
+        const std::shared_ptr<Allocator>& allocator, FnPtr auto target, FnPtr auto destination) {
         return create(allocator, reinterpret_cast<void*>(target), reinterpret_cast<void*>(destination));
     }
 
@@ -216,7 +211,7 @@ class InlineHook final {
     /// @return The result of calling the original function.
     /// @note This function will use the default calling convention set by your compiler.
     /// @note This function is unsafe because it doesn't lock the mutex. Only use this if you don't care about unhook
-    // safety or are worried about the performance cost of locking the mutex.
+    /// safety or are worried about the performance cost of locking the mutex.
     template <typename RetT = void, typename... Args> RetT unsafe_call(Args... args) {
         return original<RetT (*)(Args...)>()(args...);
     }
@@ -228,7 +223,7 @@ class InlineHook final {
     /// @return The result of calling the original function.
     /// @note This function will use the __cdecl calling convention.
     /// @note This function is unsafe because it doesn't lock the mutex. Only use this if you don't care about unhook
-    // safety or are worried about the performance cost of locking the mutex.
+    /// safety or are worried about the performance cost of locking the mutex.
     template <typename RetT = void, typename... Args> RetT unsafe_ccall(Args... args) {
         return original<RetT(__cdecl*)(Args...)>()(args...);
     }
@@ -240,7 +235,7 @@ class InlineHook final {
     /// @return The result of calling the original function.
     /// @note This function will use the __thiscall calling convention.
     /// @note This function is unsafe because it doesn't lock the mutex. Only use this if you don't care about unhook
-    // safety or are worried about the performance cost of locking the mutex.
+    /// safety or are worried about the performance cost of locking the mutex.
     template <typename RetT = void, typename... Args> RetT unsafe_thiscall(Args... args) {
         return original<RetT(__thiscall*)(Args...)>()(args...);
     }
@@ -252,7 +247,7 @@ class InlineHook final {
     /// @return The result of calling the original function.
     /// @note This function will use the __stdcall calling convention.
     /// @note This function is unsafe because it doesn't lock the mutex. Only use this if you don't care about unhook
-    // safety or are worried about the performance cost of locking the mutex.
+    /// safety or are worried about the performance cost of locking the mutex.
     template <typename RetT = void, typename... Args> RetT unsafe_stdcall(Args... args) {
         return original<RetT(__stdcall*)(Args...)>()(args...);
     }
@@ -264,7 +259,7 @@ class InlineHook final {
     /// @return The result of calling the original function.
     /// @note This function will use the __fastcall calling convention.
     /// @note This function is unsafe because it doesn't lock the mutex. Only use this if you don't care about unhook
-    // safety or are worried about the performance cost of locking the mutex.
+    /// safety or are worried about the performance cost of locking the mutex.
     template <typename RetT = void, typename... Args> RetT unsafe_fastcall(Args... args) {
         return original<RetT(__fastcall*)(Args...)>()(args...);
     }
@@ -287,4 +282,4 @@ class InlineHook final {
 
     void destroy();
 };
-} // namespace safetyhook
+} // namespace safetyhook

include/safetyhook/mid_hook.hpp

@@ -9,6 +9,7 @@
 #include <safetyhook/allocator.hpp>
 #include <safetyhook/context.hpp>
 #include <safetyhook/inline_hook.hpp>
+#include <safetyhook/utility.hpp>
 
 namespace safetyhook {
 
@@ -56,15 +57,12 @@ class MidHook final {
     [[nodiscard]] static std::expected<MidHook, Error> create(void* target, MidHookFn destination);
 
     /// @brief Creates a new MidHook object.
-    /// @tparam T The type of the function to hook.
     /// @param target The address of the function to hook.
     /// @param destination The destination function.
     /// @return The MidHook object or a MidHook::Error if an error occurred.
     /// @note This will use the default global Allocator.
     /// @note If you don't care about error handling, use the easy API (safetyhook::create_mid).
-    template <typename T>
-        requires std::is_function_v<T>
-    [[nodiscard]] static std::expected<MidHook, Error> create(T* target, MidHookFn destination) {
+    [[nodiscard]] static std::expected<MidHook, Error> create(FnPtr auto target, MidHookFn destination) {
         return create(reinterpret_cast<void*>(target), destination);
     }
 
@@ -84,10 +82,8 @@ class MidHook final {
     /// @param destination The destination function.
     /// @return The MidHook object or a MidHook::Error if an error occurred.
     /// @note If you don't care about error handling, use the easy API (safetyhook::create_mid).
-    template <typename T>
-        requires std::is_function_v<T>
     [[nodiscard]] static std::expected<MidHook, Error> create(
-        const std::shared_ptr<Allocator>& allocator, T* target, MidHookFn destination) {
+        const std::shared_ptr<Allocator>& allocator, FnPtr auto target, MidHookFn destination) {
         return create(allocator, reinterpret_cast<void*>(target), destination);
     }
 
@@ -128,4 +124,4 @@ class MidHook final {
     std::expected<void, Error> setup(
         const std::shared_ptr<Allocator>& allocator, uint8_t* target, MidHookFn destination);
 };
-} // namespace safetyhook
+} // namespace safetyhook

include/safetyhook/thread_freezer.hpp

@@ -5,7 +5,6 @@
 
 #include <cstdint>
 #include <functional>
-#include <vector>
 
 #include <Windows.h>
 

include/safetyhook/utility.hpp

@@ -2,9 +2,15 @@
 
 #include <algorithm>
 #include <cstdint>
+#include <type_traits>
 
 namespace safetyhook {
 template <typename T> constexpr void store(uint8_t* address, const T& value) {
     std::copy_n(reinterpret_cast<const uint8_t*>(&value), sizeof(T), address);
 }
-} // namespace safetyhook
+
+template <typename T>
+concept FnPtr = requires(T f) { std::is_pointer_v<T>&& std::is_function_v<std::remove_pointer_t<T>>; };
+
+bool is_executable(uint8_t* address);
+} // namespace safetyhook