/// <summary>
/// Opens a handle to the driver.
/// </summary>
/// <returns></returns>
public static SafeFileHandle OpenDevice(
String deviceName,
bool useAsync
)
{
// Open the handle to the driver
SafeFileHandle device = Kernel32Import.CreateFile(deviceName,
Kernel32Import.GENERIC_READ | Kernel32Import.GENERIC_WRITE,
Kernel32Import.FILE_SHARE_READ | Kernel32Import.FILE_SHARE_WRITE,
IntPtr.Zero,
Kernel32Import.OPEN_EXISTING,
useAsync ? Kernel32Import.FILE_FLAG_OVERLAPPED : 0,
IntPtr.Zero
);
if (device.IsInvalid)
{
throw new Win32Exception();
}
// Bind the handle to the thread pool if performing asynchronous
// operation, for later completion
if (useAsync)
{
ThreadPool.BindHandle(device);
}
return(device);
}
/// <summary>
/// Method to initiate a SYNCHRONOUS control command to the driver.
///
/// The device handle MUST have been opened without the async option
/// set prior to calling this method.
///
/// This overload takes an int input and is used to query the driver
/// what the mesh role is for this device.
///
/// The main return value of this function is whether the
/// DeviceIoControl operation succeeded or not; therefore, to determine
/// if this device is a border router or not, the caller must verify
/// both the result and the isBorderRouter parameter.
/// </summary>
/// <param name="device"></param>
/// <param name="controlCode"></param>
public unsafe static bool SynchronousControl(
SafeFileHandle device,
int controlCode,
out bool isBorderRouter
)
{
uint meshRole = 0;
uint bytesReturned = 0; // don't care about this in synchronous I/O
bool result = Kernel32Import.DeviceIoControl(device,
controlCode,
0,
sizeof(uint),
ref meshRole,
sizeof(uint),
ref bytesReturned,
null
);
if (result)
{
// Record the answer from the driver
if (meshRole == 1)
{
isBorderRouter = true;
}
else
{
isBorderRouter = false;
}
}
else
{
isBorderRouter = false;
}
// Close the driver handle
Kernel32Import.CloseHandle(device);
return(result);
}
/// <summary>
/// Method to initiate a SYNCHRONOUS control command to the driver.
///
/// The device handle MUST have been opened without the async option
/// set prior to calling this method.
///
/// This overload does not take any input and is used only in the
/// list purge IOCTLs that have no input or output.
/// </summary>
/// <param name="device"></param>
/// <param name="controlCode"></param>
public unsafe static bool SynchronousControl(
SafeFileHandle device,
int controlCode
)
{
uint bytesReturned = 0; // don't care about this in synchronous I/O
bool result = Kernel32Import.DeviceIoControl(device,
controlCode,
new byte[0],
0,
new byte[0],
0,
ref bytesReturned,
null
);
// Close the driver handle
Kernel32Import.CloseHandle(device);
return(result);
}
/// <summary>
/// Method to initiate a SYNCHRONOUS control command to the driver.
///
/// The device handle MUST have been opened without the async option
/// set prior to calling this method.
///
/// This overload takes a string input and is used for list operations.
/// </summary>
/// <param name="device"></param>
/// <param name="controlCode"></param>
public unsafe static bool SynchronousControl(
SafeFileHandle device,
int controlCode,
String ipv6Address
)
{
uint bytesReturned = 0; // don't care about this in synchronous I/O
bool result = Kernel32Import.DeviceIoControl(device,
controlCode,
ipv6Address,
sizeof(char) * ipv6Address.Length,
null,
0,
ref bytesReturned,
null
);
// Close the driver handle
Kernel32Import.CloseHandle(device);
return(result);
}
/// <summary>
/// Helper method that actually sends the given IOCTL to the driver by
/// calling the native DeviceIOControl() function. Called by AsyncControl().
/// </summary>
private static unsafe void NativeAsyncControl(
SafeFileHandle device,
int controlCode,
SafePinnedObject outBuffer,
ref uint bytesReturned,
NativeOverlapped *nativeOverlapped
)
{
bool succeeded = Kernel32Import.DeviceIoControl(device,
controlCode,
null,
0,
outBuffer,
outBuffer.Size,
ref bytesReturned,
nativeOverlapped
);
// If DeviceIoControl returns TRUE, the operation completed
// synchronously
if (succeeded)
{
throw new InvalidOperationException($"Async call to DeviceIoControl completed synchronously.");
}
// DeviceIoControl is operating asynchronously; test the returned
// error code to see if it is pending or not
Int32 error = Marshal.GetLastWin32Error();
const Int32 cErrorIOPending = 997; // system-defined code for pending I/O
if (error == cErrorIOPending)
{
return;
}
// Throw an exception if DeviceIoControl fails altogether
throw new InvalidOperationException($"Control failed with error {error}");
}
