From 50fb354983432abd6a7ef9a6c509d6a0045a3bbe Mon Sep 17 00:00:00 2001
From: slayercio <slayer.github@gmail.com>
Date: Tue, 18 Nov 2025 20:01:46 +0100
Subject: [PATCH] feat: added inline hook manager

---
 src/detail/hooking.hpp |  31 ++++++++++++
 src/impl/hooking.cpp   | 105 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 src/detail/hooking.hpp
 create mode 100644 src/impl/hooking.cpp

diff --git a/src/detail/hooking.hpp b/src/detail/hooking.hpp
new file mode 100644
index 0000000..3f240db
--- /dev/null
+++ b/src/detail/hooking.hpp
@@ -0,0 +1,31 @@
+#pragma once
+#include <cstddef>
+#include <vector>
+
+namespace fxn
+{
+    struct HookInfo
+    {
+        void* targetFunction;
+        void* hookFunction;
+        std::vector<std::byte> originalBytes;
+    };
+
+    class HookingManager
+    {
+    private:
+        std::vector<HookInfo> m_Hooks;
+
+    protected:
+        HookingManager();
+        ~HookingManager();
+
+    public:
+        static HookingManager& GetInstance();
+        static void Destroy();
+
+    public:
+        bool InstallHook(void* targetFunction, void* hookFunction);
+        bool RemoveHook(void* targetFunction);
+    };
+}
\ No newline at end of file
diff --git a/src/impl/hooking.cpp b/src/impl/hooking.cpp
new file mode 100644
index 0000000..c844540
--- /dev/null
+++ b/src/impl/hooking.cpp
@@ -0,0 +1,105 @@
+#include <array>
+#include <Windows.h>
+
+#include <detail/hooking.hpp>
+
+namespace fxn
+{
+    namespace
+    {
+        HookingManager* g_HookingManager = nullptr;
+    }
+
+    HookingManager::HookingManager()
+    {
+    }
+
+    HookingManager::~HookingManager()
+    {
+        for (const auto& hook : m_Hooks)
+        {
+            RemoveHook(hook.targetFunction);
+        }
+
+        m_Hooks.clear();
+    }
+
+    HookingManager& HookingManager::GetInstance()
+    {
+        if (!g_HookingManager)
+        {
+            g_HookingManager = new HookingManager();
+        }
+
+        return *g_HookingManager;
+    }
+
+    void HookingManager::Destroy()
+    {
+        if (g_HookingManager)
+        {
+            delete g_HookingManager;
+        }
+     
+        g_HookingManager = nullptr;
+    }
+
+    bool HookingManager::InstallHook(void* targetFunction, void* hookFunction)
+    {
+        /*
+            mov rax, <hookFunction>
+            jmp rax
+        */
+        constexpr auto HOOK_SIZE = 12;
+        constexpr auto HOOK_INSTRUCTION = std::array<std::uint8_t, HOOK_SIZE>
+        {
+            0x48, 0xB8,
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+            0xFF, 0xE0
+        };
+
+        auto hookBytes = HOOK_INSTRUCTION;
+        *reinterpret_cast<std::uintptr_t*>(&hookBytes[2]) = reinterpret_cast<std::uintptr_t>(hookFunction);
+
+        DWORD oldProtect;
+        if (!VirtualProtect(targetFunction, HOOK_SIZE, PAGE_EXECUTE_READWRITE, &oldProtect))
+        {
+            return false;
+        }
+
+        HookInfo hookInfo;
+        hookInfo.targetFunction = targetFunction;
+        hookInfo.hookFunction = hookFunction;
+        hookInfo.originalBytes.resize(HOOK_SIZE);
+        std::memcpy(hookInfo.originalBytes.data(), targetFunction, HOOK_SIZE);
+
+        std::memcpy(targetFunction, hookBytes.data(), HOOK_SIZE);
+        VirtualProtect(targetFunction, HOOK_SIZE, oldProtect, &oldProtect);
+
+        m_Hooks.push_back(std::move(hookInfo));
+        return true;
+    }
+
+    bool HookingManager::RemoveHook(void* targetFunction)
+    {
+        auto it = std::find_if(m_Hooks.begin(), m_Hooks.end(),
+            [targetFunction](const HookInfo& hook) { return hook.targetFunction == targetFunction; });
+
+        if (it == m_Hooks.end())
+        {
+            return false;
+        }
+
+        DWORD oldProtect;
+        if (!VirtualProtect(targetFunction, it->originalBytes.size(), PAGE_EXECUTE_READWRITE, &oldProtect))
+        {
+            return false;
+        }
+
+        std::memcpy(targetFunction, it->originalBytes.data(), it->originalBytes.size());
+        VirtualProtect(targetFunction, it->originalBytes.size(), oldProtect, &oldProtect);
+
+        m_Hooks.erase(it);
+        return true;
+    }
+}
\ No newline at end of file