mem.cpp

#include "mem.h"

//https://guidedhacking.com/threads/how-to-hack-any-game-first-internal-hack-dll-tutorial.12142/

void mem::Patch(BYTE* dst, BYTE* src, unsigned int size)
{
	DWORD oldprotect;
	VirtualProtect(dst, size, PAGE_EXECUTE_READWRITE, &oldprotect);

	memcpy(dst, src, size);
	VirtualProtect(dst, size, oldprotect, &oldprotect);
}


void mem::Nop(BYTE* dst, unsigned int size)
{
	DWORD oldprotect;
	VirtualProtect(dst, size, PAGE_EXECUTE_READWRITE, &oldprotect);
	memset(dst, 0x90, size);
	VirtualProtect(dst, size, oldprotect, &oldprotect);
}


uintptr_t mem::FindDMAAddy(uintptr_t ptr, std::vector<unsigned int> offsets)
{
	uintptr_t addr = ptr;
	for (unsigned int i = 0; i < offsets.size(); ++i)
	{
		addr = *(uintptr_t*)addr;
		addr += offsets[i];
	}
	return addr;
}


bool mem::Detour32(BYTE* src, BYTE* dst, const uintptr_t len)
{
	if (len < 5) return false;

	DWORD curProtection;
	VirtualProtect(src, len, PAGE_EXECUTE_READWRITE, &curProtection);

	uintptr_t relativeAdress = dst - src - 5;

	*src = 0xE9;

	*(uintptr_t*)(src + 1) = relativeAdress;

	VirtualProtect(src, len, curProtection, &curProtection);
	return true;
}
BYTE* mem::TrampHook32(BYTE* src, BYTE* dst, const uintptr_t len)
{
	if (len < 5) return 0;

	BYTE* gateway = (BYTE*)VirtualAlloc(0, len, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);

	memcpy_s(gateway, len, src, len);

	uintptr_t gatewayRealtiveAddr = src - gateway - 5;

	*(gateway + len) = 0xE9;

	*(uintptr_t*)((uintptr_t)gateway + len + 1) = gatewayRealtiveAddr;

	Detour32(src, dst, len);

	return gateway;
}