Initial commit

src/common/asm_code.cpp

@@ -0,0 +1,13 @@
+#include <common/asm_code.h>
+#include <common/hooking.h>
+
+#include <Windows.h>
+
+void asm_code::build() {
+	m_code = reinterpret_cast<decltype(m_code)>(hooking::get_executable_memory(GetModuleHandle(nullptr), m_offset));
+	memcpy(m_code, m_buffer, m_offset);
+
+	for (auto addr : m_addresses) {
+		addr->build(m_code);
+	}
+}

src/common/config.cpp

@@ -0,0 +1,18 @@
+#include <common/config.h>
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <filesystem>
+
+config::config(token) {
+	m_json = new nlohmann::json();
+
+	if (std::filesystem::exists("d2tweaks.json")) {
+		const std::ifstream cfgFile("d2tweaks.json");
+		std::stringstream ss;
+		ss << cfgFile.rdbuf();
+
+		m_json->parse(ss.str());
+	}
+}

src/common/hooking.cpp

@@ -0,0 +1,88 @@
+#include <common/hooking.h>
+
+#include <MinHook.h>
+#include <cstdint>
+#include <spdlog/spdlog.h>
+
+// Size of each memory block. (= page size of VirtualAlloc)
+const size_t MEMORY_BLOCK_SIZE = 0x1000;
+
+static void* allocate_function_stub(void* origin, void* ptr, size_t size) {
+	static void* current_stub = nullptr;
+
+	if (!current_stub) {
+		current_stub =
+			VirtualAlloc(nullptr, MEMORY_BLOCK_SIZE, MEM_COMMIT | MEM_RESERVE,
+						 PAGE_EXECUTE_READWRITE);
+	}
+
+	if (!current_stub)
+		return nullptr;
+
+	const auto code = static_cast<char*>(current_stub);
+
+	DWORD old_protect;
+	VirtualProtect(code, size, PAGE_EXECUTE_READWRITE, &old_protect);
+
+	*reinterpret_cast<uint8_t*>(code) = 0xB8;
+	*reinterpret_cast<uintptr_t*>(code + 1) = reinterpret_cast<uintptr_t>(ptr);
+
+	*reinterpret_cast<uint16_t*>(code + 5) = 0xE0FF;
+
+	spdlog::debug("Created function stub at {0}", current_stub);
+
+	current_stub = reinterpret_cast<void*>(reinterpret_cast<uint64_t>(current_stub) + size);
+
+	return code;
+}
+
+hooking::mh_status_t hooking::details::hook(void* target, void* detour, void** original) {
+	mh_status_t result = static_cast<mh_status_t>(MH_CreateHook(target, detour, original));
+	MH_EnableHook(nullptr);
+	return result;
+}
+
+intptr_t hooking::get_executable_memory(void* origin, size_t size) {
+	const auto stub = reinterpret_cast<intptr_t>(allocate_function_stub(origin, nullptr, size));
+	memset(reinterpret_cast<void*>(stub), 0, size);
+	return stub;
+}
+
+void* hooking::set_call(void* address, void* function, size_t stubSize) {
+	const auto stub = reinterpret_cast<int32_t>(allocate_function_stub(address, function, stubSize));
+
+	DWORD old_protect;
+	VirtualProtect(address, 5, PAGE_EXECUTE_READWRITE, &old_protect);
+
+	*static_cast<unsigned char*>(address) = 0xE8;
+	*reinterpret_cast<int32_t*>(static_cast<char*>(address) + 1) = stub - reinterpret_cast<int32_t>(address) - 5;
+
+	VirtualProtect(address, 5, old_protect, &old_protect);
+
+	assert(get_call(address) == reinterpret_cast<void*>(stub));
+
+	return reinterpret_cast<void*>(stub);
+}
+
+void* hooking::set_jmp(void* address, void* function, size_t stubSize) {
+	const auto stub = reinterpret_cast<int32_t>(allocate_function_stub(address, function, stubSize));
+
+	DWORD old_protect;
+	VirtualProtect(address, 5, PAGE_EXECUTE_READWRITE, &old_protect);
+
+	*static_cast<unsigned char*>(address) = 0xE9;
+	*reinterpret_cast<int32_t*>(static_cast<char*>(address) + 1) = stub - reinterpret_cast<int32_t>(address) - 5;
+
+	VirtualProtect(address, 5, old_protect, &old_protect);
+
+	assert(get_call(address) == reinterpret_cast<void*>(stub));
+
+	return reinterpret_cast<void*>(stub);
+}
+
+void* hooking::get_call(void* address) {
+	auto target = *reinterpret_cast<int32_t*>(static_cast<char*>(address) + 1);
+	target += reinterpret_cast<intptr_t>(address) + 5;
+
+	return reinterpret_cast<void*>(target);
+}

src/common/string_utils.cpp

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+#include <common/string_utils.h>
+
+#include <Windows.h>
+
+std::wstring string_utils::string_to_wstring(const std::string& str) {
+	if (str.empty())
+		return std::wstring();
+
+	const auto sizeNeeded = MultiByteToWideChar(CP_ACP, 0, &str[0], static_cast<int>(str.size()), nullptr, 0);
+	std::wstring wstrTo(sizeNeeded, 0);
+	MultiByteToWideChar(CP_ACP, 0, &str[0], static_cast<int>(str.size()), &wstrTo[0], sizeNeeded);
+
+	return wstrTo;
+}