Win32 API function to programmatically enable/disable device
I am writing a small C# app to disable a device (my laptop touchpad) whenever another mouse device is detected, and enable the touchpad again if a mouse is not detected. I am not even able to disable the touchpad in device manager (it is running on the default mouse class driver).
I am getting into device driver development so I thought maybe I could write a little filter driver that would just accept IOCTLs to enable and disable passing mouse event messages up the device stack, and get messages from user mode via a raw PDO. However, I asked that question and somebody has suggested that I can do this in usermode via the SetupDi.. functions. That would be really good, because this raw PDO communication method is a PITA to work with.
I have only used SetupDiGetClassDevs before, and there are so many of them, can someone with more experience with this part of the Win32 API just tell me quickly what one I should call to stop/disable a mouse device or its interface or if there is something somewhere in the dark corners of the framework that will do this (maybe in WMI?).
Update (24/9/09) I figured out how to do this with a filter driver and posted how I did it on my original question. I still want to know if it is possible to enable or disable devices directly from Win32 and if so, how - so I will leave this question open.
Answer
You can enable/disable devices from Win32 (and hence from C# via P/Invoke) using the SetupDi APIs but not all devices are "disable-able" in this way.
The problem you'll run into trying to disable your touchpad from Win32 (or WMI or any other API which calls down into the SetupDi* family of functions) is that the default mouse driver which is in most laptops with a touchpad ("PS/2 compatible mouse") doesn't support being disabled using SetupDi API's. I suspect this may be because actual old mice using PS/2 connectors can't be hot-detached without hosing the hardware.
To verify that you can't disable, go into Device Manager and right-click on your mouse driver. If you see a disable option, you can use SetupDi to disable it. If no disable option, you're out of luck... welcome to IOCTL-land!
If you do see a disable option, then the code below (ported to C# from a VB sample I found here) should let you disable and re-enable the device.
Here's the code to call the library:
public static void EnableMouse(bool enable)
{
// every type of device has a hard-coded GUID, this is the one for mice
Guid mouseGuid = new Guid("{4d36e96f-e325-11ce-bfc1-08002be10318}");
// get this from the properties dialog box of this device in Device Manager
string instancePath = @"ACPI\PNP0F03\4&3688D3F&0";
DeviceHelper.SetDeviceEnabled(mouseGuid, instancePath, enable);
}
Here's the library itself, adapted from here.
using System;
using System.Text;
using System.Collections.Generic;
using DisableDevice;
using System.Runtime.InteropServices;
using System.ComponentModel;
using Microsoft.Win32.SafeHandles;
using System.Security;
using System.Runtime.ConstrainedExecution;
using System.Management;
namespace DisableDevice
{
[Flags()]
internal enum SetupDiGetClassDevsFlags
{
Default = 1,
Present = 2,
AllClasses = 4,
Profile = 8,
DeviceInterface = (int)0x10
}
internal enum DiFunction
{
SelectDevice = 1,
InstallDevice = 2,
AssignResources = 3,
Properties = 4,
Remove = 5,
FirstTimeSetup = 6,
FoundDevice = 7,
SelectClassDrivers = 8,
ValidateClassDrivers = 9,
InstallClassDrivers = (int)0xa,
CalcDiskSpace = (int)0xb,
DestroyPrivateData = (int)0xc,
ValidateDriver = (int)0xd,
Detect = (int)0xf,
InstallWizard = (int)0x10,
DestroyWizardData = (int)0x11,
PropertyChange = (int)0x12,
EnableClass = (int)0x13,
DetectVerify = (int)0x14,
InstallDeviceFiles = (int)0x15,
UnRemove = (int)0x16,
SelectBestCompatDrv = (int)0x17,
AllowInstall = (int)0x18,
RegisterDevice = (int)0x19,
NewDeviceWizardPreSelect = (int)0x1a,
NewDeviceWizardSelect = (int)0x1b,
NewDeviceWizardPreAnalyze = (int)0x1c,
NewDeviceWizardPostAnalyze = (int)0x1d,
NewDeviceWizardFinishInstall = (int)0x1e,
Unused1 = (int)0x1f,
InstallInterfaces = (int)0x20,
DetectCancel = (int)0x21,
RegisterCoInstallers = (int)0x22,
AddPropertyPageAdvanced = (int)0x23,
AddPropertyPageBasic = (int)0x24,
Reserved1 = (int)0x25,
Troubleshooter = (int)0x26,
PowerMessageWake = (int)0x27,
AddRemotePropertyPageAdvanced = (int)0x28,
UpdateDriverUI = (int)0x29,
Reserved2 = (int)0x30
}
internal enum StateChangeAction
{
Enable = 1,
Disable = 2,
PropChange = 3,
Start = 4,
Stop = 5
}
[Flags()]
internal enum Scopes
{
Global = 1,
ConfigSpecific = 2,
ConfigGeneral = 4
}
internal enum SetupApiError
{
NoAssociatedClass = unchecked((int)0xe0000200),
ClassMismatch = unchecked((int)0xe0000201),
DuplicateFound = unchecked((int)0xe0000202),
NoDriverSelected = unchecked((int)0xe0000203),
KeyDoesNotExist = unchecked((int)0xe0000204),
InvalidDevinstName = unchecked((int)0xe0000205),
InvalidClass = unchecked((int)0xe0000206),
DevinstAlreadyExists = unchecked((int)0xe0000207),
DevinfoNotRegistered = unchecked((int)0xe0000208),
InvalidRegProperty = unchecked((int)0xe0000209),
NoInf = unchecked((int)0xe000020a),
NoSuchHDevinst = unchecked((int)0xe000020b),
CantLoadClassIcon = unchecked((int)0xe000020c),
InvalidClassInstaller = unchecked((int)0xe000020d),
DiDoDefault = unchecked((int)0xe000020e),
DiNoFileCopy = unchecked((int)0xe000020f),
InvalidHwProfile = unchecked((int)0xe0000210),
NoDeviceSelected = unchecked((int)0xe0000211),
DevinfolistLocked = unchecked((int)0xe0000212),
DevinfodataLocked = unchecked((int)0xe0000213),
DiBadPath = unchecked((int)0xe0000214),
NoClassInstallParams = unchecked((int)0xe0000215),
FileQueueLocked = unchecked((int)0xe0000216),
BadServiceInstallSect = unchecked((int)0xe0000217),
NoClassDriverList = unchecked((int)0xe0000218),
NoAssociatedService = unchecked((int)0xe0000219),
NoDefaultDeviceInterface = unchecked((int)0xe000021a),
DeviceInterfaceActive = unchecked((int)0xe000021b),
DeviceInterfaceRemoved = unchecked((int)0xe000021c),
BadInterfaceInstallSect = unchecked((int)0xe000021d),
NoSuchInterfaceClass = unchecked((int)0xe000021e),
InvalidReferenceString = unchecked((int)0xe000021f),
InvalidMachineName = unchecked((int)0xe0000220),
RemoteCommFailure = unchecked((int)0xe0000221),
MachineUnavailable = unchecked((int)0xe0000222),
NoConfigMgrServices = unchecked((int)0xe0000223),
InvalidPropPageProvider = unchecked((int)0xe0000224),
NoSuchDeviceInterface = unchecked((int)0xe0000225),
DiPostProcessingRequired = unchecked((int)0xe0000226),
InvalidCOInstaller = unchecked((int)0xe0000227),
NoCompatDrivers = unchecked((int)0xe0000228),
NoDeviceIcon = unchecked((int)0xe0000229),
InvalidInfLogConfig = unchecked((int)0xe000022a),
DiDontInstall = unchecked((int)0xe000022b),
InvalidFilterDriver = unchecked((int)0xe000022c),
NonWindowsNTDriver = unchecked((int)0xe000022d),
NonWindowsDriver = unchecked((int)0xe000022e),
NoCatalogForOemInf = unchecked((int)0xe000022f),
DevInstallQueueNonNative = unchecked((int)0xe0000230),
NotDisableable = unchecked((int)0xe0000231),
CantRemoveDevinst = unchecked((int)0xe0000232),
InvalidTarget = unchecked((int)0xe0000233),
DriverNonNative = unchecked((int)0xe0000234),
InWow64 = unchecked((int)0xe0000235),
SetSystemRestorePoint = unchecked((int)0xe0000236),
IncorrectlyCopiedInf = unchecked((int)0xe0000237),
SceDisabled = unchecked((int)0xe0000238),
UnknownException = unchecked((int)0xe0000239),
PnpRegistryError = unchecked((int)0xe000023a),
RemoteRequestUnsupported = unchecked((int)0xe000023b),
NotAnInstalledOemInf = unchecked((int)0xe000023c),
InfInUseByDevices = unchecked((int)0xe000023d),
DiFunctionObsolete = unchecked((int)0xe000023e),
NoAuthenticodeCatalog = unchecked((int)0xe000023f),
AuthenticodeDisallowed = unchecked((int)0xe0000240),
AuthenticodeTrustedPublisher = unchecked((int)0xe0000241),
AuthenticodeTrustNotEstablished = unchecked((int)0xe0000242),
AuthenticodePublisherNotTrusted = unchecked((int)0xe0000243),
SignatureOSAttributeMismatch = unchecked((int)0xe0000244),
OnlyValidateViaAuthenticode = unchecked((int)0xe0000245)
}
[StructLayout(LayoutKind.Sequential)]
internal struct DeviceInfoData
{
public int Size;
public Guid ClassGuid;
public int DevInst;
public IntPtr Reserved;
}
[StructLayout(LayoutKind.Sequential)]
internal struct PropertyChangeParameters
{
public int Size;
// part of header. It's flattened out into 1 structure.
public DiFunction DiFunction;
public StateChangeAction StateChange;
public Scopes Scope;
public int HwProfile;
}
internal class NativeMethods
{
private const string setupapi = "setupapi.dll";
private NativeMethods()
{
}
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiCallClassInstaller(DiFunction installFunction, SafeDeviceInfoSetHandle deviceInfoSet, [In()]
ref DeviceInfoData deviceInfoData);
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiEnumDeviceInfo(SafeDeviceInfoSetHandle deviceInfoSet, int memberIndex, ref DeviceInfoData deviceInfoData);
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode, SetLastError = true)]
public static extern SafeDeviceInfoSetHandle SetupDiGetClassDevs([In()]
ref Guid classGuid, [MarshalAs(UnmanagedType.LPWStr)]
string enumerator, IntPtr hwndParent, SetupDiGetClassDevsFlags flags);
/*
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiGetDeviceInstanceId(SafeDeviceInfoSetHandle deviceInfoSet, [In()]
ref DeviceInfoData did, [MarshalAs(UnmanagedType.LPTStr)]
StringBuilder deviceInstanceId, int deviceInstanceIdSize, [Out()]
ref int requiredSize);
*/
[DllImport("setupapi.dll", SetLastError = true, CharSet = CharSet.Auto)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiGetDeviceInstanceId(
IntPtr DeviceInfoSet,
ref DeviceInfoData did,
[MarshalAs(UnmanagedType.LPTStr)] StringBuilder DeviceInstanceId,
int DeviceInstanceIdSize,
out int RequiredSize
);
[SuppressUnmanagedCodeSecurity()]
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiDestroyDeviceInfoList(IntPtr deviceInfoSet);
[DllImport(setupapi, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetupDiSetClassInstallParams(SafeDeviceInfoSetHandle deviceInfoSet, [In()]
ref DeviceInfoData deviceInfoData, [In()]
ref PropertyChangeParameters classInstallParams, int classInstallParamsSize);
}
internal class SafeDeviceInfoSetHandle : SafeHandleZeroOrMinusOneIsInvalid
{
public SafeDeviceInfoSetHandle()
: base(true)
{
}
protected override bool ReleaseHandle()
{
return NativeMethods.SetupDiDestroyDeviceInfoList(this.handle);
}
}
public sealed class DeviceHelper
{
private DeviceHelper()
{
}
/// <summary>
/// Enable or disable a device.
/// </summary>
/// <param name="classGuid">The class guid of the device. Available in the device manager.</param>
/// <param name="instanceId">The device instance id of the device. Available in the device manager.</param>
/// <param name="enable">True to enable, False to disable.</param>
/// <remarks>Will throw an exception if the device is not Disableable.</remarks>
public static void SetDeviceEnabled(Guid classGuid, string instanceId, bool enable)
{
SafeDeviceInfoSetHandle diSetHandle = null;
try
{
// Get the handle to a device information set for all devices matching classGuid that are present on the
// system.
diSetHandle = NativeMethods.SetupDiGetClassDevs(ref classGuid, null, IntPtr.Zero, SetupDiGetClassDevsFlags.Present);
// Get the device information data for each matching device.
DeviceInfoData[] diData = GetDeviceInfoData(diSetHandle);
// Find the index of our instance. i.e. the touchpad mouse - I have 3 mice attached...
int index = GetIndexOfInstance(diSetHandle, diData, instanceId);
// Disable...
EnableDevice(diSetHandle, diData[index], enable);
}
finally
{
if (diSetHandle != null)
{
if (diSetHandle.IsClosed == false)
{
diSetHandle.Close();
}
diSetHandle.Dispose();
}
}
}
private static DeviceInfoData[] GetDeviceInfoData(SafeDeviceInfoSetHandle handle)
{
List<DeviceInfoData> data = new List<DeviceInfoData>();
DeviceInfoData did = new DeviceInfoData();
int didSize = Marshal.SizeOf(did);
did.Size = didSize;
int index = 0;
while (NativeMethods.SetupDiEnumDeviceInfo(handle, index, ref did))
{
data.Add(did);
index += 1;
did = new DeviceInfoData();
did.Size = didSize;
}
return data.ToArray();
}
// Find the index of the particular DeviceInfoData for the instanceId.
private static int GetIndexOfInstance(SafeDeviceInfoSetHandle handle, DeviceInfoData[] diData, string instanceId)
{
const int ERROR_INSUFFICIENT_BUFFER = 122;
for (int index = 0; index <= diData.Length - 1; index++)
{
StringBuilder sb = new StringBuilder(1);
int requiredSize = 0;
bool result = NativeMethods.SetupDiGetDeviceInstanceId(handle.DangerousGetHandle(), ref diData[index], sb, sb.Capacity, out requiredSize);
if (result == false && Marshal.GetLastWin32Error() == ERROR_INSUFFICIENT_BUFFER)
{
sb.Capacity = requiredSize;
result = NativeMethods.SetupDiGetDeviceInstanceId(handle.DangerousGetHandle(), ref diData[index], sb, sb.Capacity, out requiredSize);
}
if (result == false)
throw new Win32Exception();
if (instanceId.Equals(sb.ToString()))
{
return index;
}
}
// not found
return -1;
}
// enable/disable...
private static void EnableDevice(SafeDeviceInfoSetHandle handle, DeviceInfoData diData, bool enable)
{
PropertyChangeParameters @params = new PropertyChangeParameters();
// The size is just the size of the header, but we've flattened the structure.
// The header comprises the first two fields, both integer.
@params.Size = 8;
@params.DiFunction = DiFunction.PropertyChange;
@params.Scope = Scopes.Global;
if (enable)
{
@params.StateChange = StateChangeAction.Enable;
}
else
{
@params.StateChange = StateChangeAction.Disable;
}
bool result = NativeMethods.SetupDiSetClassInstallParams(handle, ref diData, ref @params, Marshal.SizeOf(@params));
if (result == false) throw new Win32Exception();
result = NativeMethods.SetupDiCallClassInstaller(DiFunction.PropertyChange, handle, ref diData);
if (result == false)
{
int err = Marshal.GetLastWin32Error();
if (err == (int)SetupApiError.NotDisableable)
throw new ArgumentException("Device can't be disabled (programmatically or in Device Manager).");
else if (err >= (int)SetupApiError.NoAssociatedClass && err <= (int)SetupApiError.OnlyValidateViaAuthenticode)
throw new Win32Exception("SetupAPI error: " + ((SetupApiError)err).ToString());
else
throw new Win32Exception();
}
}
}
}
Note that when you get an Index-Out-Of-Bounds exception on the line int index = GetIndexOfInstance(diSetHandle, diData, instanceId);, you might have used the wrong classGuid for the device or the wrong instanceId.
Also note that when you run this code on a 64-bit Windows platform, you should target the 64-bit platform when you build your application. Otherwise - i.e. when running your application as a 32-bit process on a 64-bit Windows platform - you will get an SetupAPI error InWow64 (ERROR_IN_WOW64).
When targetting a 64-bit Windows platform, you might also have to make changes to other parts of your application, e.g. when doing pointer arithmetic, in order to prevent overflows.