/// <summary>
/// Primitive patching. Inserts a jump to 'target' at 'site'. Works even if both methods'
/// callers have already been compiled.
/// </summary>
/// <param name="site"></param>
/// <param name="target"></param>
private static RedirectCallsState PatchJumpTo(IntPtr site, IntPtr target)
{
var state = new RedirectCallsState();
// R11 is volatile.
unsafe
{
var sitePtr = (byte*) site.ToPointer();
state.a = *sitePtr;
state.b = *(sitePtr + 1);
state.c = *(sitePtr + 10);
state.d = *(sitePtr + 11);
state.e = *(sitePtr + 12);
state.f = *(ulong*) (sitePtr + 2);
*sitePtr = 0x49; // mov r11, target
*(sitePtr + 1) = 0xBB;
*(ulong*) (sitePtr + 2) = (ulong) target.ToInt64();
*(sitePtr + 10) = 0x41; // jmp r11
*(sitePtr + 11) = 0xFF;
*(sitePtr + 12) = 0xE3;
}
return state;
}
public static void Deploy()
{
Debug.Log("Detouring Input Methods");
if (_isPressedOriginal == null)
{
throw new NullReferenceException("Original IsPressed method not found");
}
if (_isKeyUpOriginal == null)
{
throw new NullReferenceException("Original IsKeyUp method not found");
}
if (_isPressedReplacement == null)
{
throw new NullReferenceException("New IsPressed method not found");
}
if (_isKeyUpReplacement == null)
{
throw new NullReferenceException("New IsKeyUp method not found");
}
_revertState1 = RedirectionHelper.RedirectCalls(_isPressedOriginal, _isPressedReplacement);
_revertState2 = RedirectionHelper.RedirectCalls(_isKeyUpOriginal, _isKeyUpReplacement);
}
public static void Deploy()
{
if (_isDeployed)
return;
_snapDirectionRevertState = RedirectionHelper.RedirectCalls(SnapDirectionOriginalMethodInfo, SnapDirectionOverrideMethodInfo);
_snapRevertState = RedirectionHelper.RedirectCalls(SnapOriginalMethodInfo, SnapOverrideMethodInfo);
_isDeployed = true;
}
public static void Deploy()
{
if (_originalGetLengthSnapMethodInfo == null) {
throw new NullReferenceException("Original GetLengthSnap method not found");
}
if (_newGetLengthSnapMethodInfo == null) {
throw new NullReferenceException("New GetLengthSnap method not found");
}
_revertState = RedirectionHelper.RedirectCalls(_originalGetLengthSnapMethodInfo,
_newGetLengthSnapMethodInfo);
}
private static void RevertJumpTo(IntPtr site, RedirectCallsState state)
{
unsafe
{
var sitePtr = (byte*) site.ToPointer();
*sitePtr = state.a; // mov r11, target
*(sitePtr + 1) = state.b;
*(ulong*) (sitePtr + 2) = state.f;
*(sitePtr + 10) = state.c; // jmp r11
*(sitePtr + 11) = state.d;
*(sitePtr + 12) = state.e;
}
}
public static void RevertRedirect(MethodInfo from, RedirectCallsState state)
{
var fptr1 = from.MethodHandle.GetFunctionPointer();
RevertJumpTo(fptr1, state);
}
