Add more walling to prevent bad input from reaching ProcessRawInput

Author: comintern

RetailCoder.VBE/Common/WinAPI/RawInput.cs

@@ -39,23 +39,41 @@ protected override void WndProc(ref Message message)
             switch ((WM)message.Msg)
             {
                 case WM.INPUT:
+                {
+                    if (message.LParam == IntPtr.Zero)
+                    {
+                        break;
+                    }
+                    InputData rawBuffer;
+                    var dwSize = 0;
+                    var res = User32.GetRawInputData(message.LParam, DataCommand.RID_INPUT, IntPtr.Zero, ref dwSize, Marshal.SizeOf(typeof(RawInputHeader)));
+                    if (res != 0)
+                    {
+                        var ex = new Win32Exception(Marshal.GetLastWin32Error());
+                        Logger.Error(ex, "Error sizing the rawinput buffer: {0}", ex.Message);
+                        break;                           
+                    }
+
+                    res = User32.GetRawInputData(message.LParam, DataCommand.RID_INPUT, out rawBuffer, ref dwSize, Marshal.SizeOf(typeof(RawInputHeader)));
+                    if (res == -1)
+                    {
+                        var ex = new Win32Exception(Marshal.GetLastWin32Error());
+                        Logger.Error(ex, "Error getting the rawinput buffer: {0}", ex.Message);
+                        break;
+                    }
+                    if (res == dwSize)
                     {
-                        InputData _rawBuffer;
-                        var dwSize = 0;
-                        User32.GetRawInputData(message.LParam, DataCommand.RID_INPUT, IntPtr.Zero, ref dwSize, Marshal.SizeOf(typeof(RawInputHeader)));
-                        int res = User32.GetRawInputData(message.LParam, DataCommand.RID_INPUT, out _rawBuffer, ref dwSize, Marshal.SizeOf(typeof(RawInputHeader)));
-                        if (dwSize != res)
-                        {
-                            var ex = new Win32Exception(Marshal.GetLastWin32Error());
-                            Logger.Error(ex, "Error getting the rawinput buffer: {0}", ex.Message);
-                            return;
-                        }
                         foreach (var device in _devices)
                         {
-                            device.ProcessRawInput(_rawBuffer);
+                            device.ProcessRawInput(rawBuffer);
                         }
                     }
-                    break;
+                    else
+                    {
+                        //Something is seriously f'd up with Windows - the number of bytes copied does not match the reported buffer size.
+                    }
+                }
+                break;
             }
             base.WndProc(ref message);
         }