EnginePK Source

void* DetourFunc(BYTE *src, const BYTE *dst, const int len)
{
	BYTE *jmp = (BYTE*)VirtualAlloc(NULL, len+5, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
	DWORD dwback, dwback2;

	VirtualProtect(src, len, PAGE_READWRITE, &dwback);
	VirtualProtect(jmp, len+5, PAGE_READWRITE, &dwback2);

	memcpy(jmp, src, len);	jmp += len;

	jmp[0] = 0xE9;
	*(DWORD*)(jmp+1) = (DWORD)(src+len - jmp) - 5;

	src[0] = 0xE9;
	*(DWORD*)(src+1) = (DWORD)(dst - src) - 5;

	VirtualProtect(jmp, len+5, dwback2, &dwback2);
	VirtualProtect(src, len, dwback, &dwback);

	return (jmp-len);
}