public static bool Start(string device, IEmulationElement loggingParent)
{
#if !PLATFORM_LINUX
throw new RecoverableException("Video capture is supported on Linux only!");
#else
// stop any previous capturer
Stop();
VideoCapturer.loggingParent = loggingParent;
loggingParent.Log(LogLevel.Debug, "Opening device: {0}...", device);
fd = LibCWrapper.Open(device, O_RDWR);
if (fd == -1)
{
loggingParent.Log(LogLevel.Error, "Couldn't open device: {0}", device);
return(false);
}
if (!CheckImageFormat())
{
loggingParent.Log(LogLevel.Error, "Device does not support JPEG output: {0}", device);
LibCWrapper.Close(fd);
return(false);
}
started = true;
return(RequestBuffer());
#endif
}
private static int Open_TUNTAP(IntPtr dev, UInt16 flags, bool persistent)
{
var ifr = Marshal.AllocHGlobal(IFR_SIZE); // we need 40 bytes, but we allocate a bit more
var fd = LibCWrapper.Open("/dev/net/tun", O_RDWR);
if (fd < 0)
{
Console.Error.WriteLine("Could not open /dev/net/tun, error: {0}", Marshal.GetLastWin32Error());
return(fd);
}
var memory = new byte[IFR_SIZE];
Array.Clear(memory, 0, IFR_SIZE);
var bytes = BitConverter.GetBytes(flags);
Array.Copy(bytes, 0, memory, IFNAMSIZ, 2);
if (dev != IntPtr.Zero)
{
var devBytes = Encoding.ASCII.GetBytes(Marshal.PtrToStringAnsi(dev));
Array.Copy(devBytes, memory, Math.Min(devBytes.Length, IFNAMSIZ));
}
Marshal.Copy(memory, 0, ifr, IFR_SIZE);
int err = 0;
if ((err = LibCWrapper.Ioctl(fd, TUNSETIFF, ifr)) < 0)
{
Console.Error.WriteLine("Could not set TUNSETIFF, error: {0}", Marshal.GetLastWin32Error());
LibCWrapper.Close(fd);
return(err);
}
if (persistent)
{
if ((err = LibCWrapper.Ioctl(fd, TUNSETPERSIST, 1)) < 0)
{
Console.Error.WriteLine("Could not set TUNSETPERSIST, error: {0}", Marshal.GetLastWin32Error());
LibCWrapper.Close(fd);
return(err);
}
}
LibCWrapper.Strcpy(dev, ifr);
Marshal.FreeHGlobal(ifr);
return(fd);
}
public static void Stop()
{
#if !PLATFORM_LINUX
throw new RecoverableException("Video capture is supported on Linux only!");
#else
if (started)
{
started = false;
FreeBuffer();
LibCWrapper.Close(fd);
}
#endif
}
public void Dispose()
{
if (stream != null)
{
stream.Close();
}
if (tapFileDescriptor != -1)
{
LibCWrapper.Close(tapFileDescriptor);
tapFileDescriptor = -1;
}
}
private static bool DoIoctl(IoctlCode code, IntPtr data)
{
int err;
if ((err = LibCWrapper.Ioctl(fd, (int)code, data)) < 0)
{
var lastErrorCode = Marshal.GetLastWin32Error();
var lastErrorMessage = LibCWrapper.Strerror(lastErrorCode);
loggingParent.Log(LogLevel.Error, "There was an error when executing the {0} ioctl: {1} (0x{2:X})", Enum.GetName(typeof(IoctlCode), code), lastErrorMessage, lastErrorCode);
LibCWrapper.Close(fd);
return(false);
}
return(true);
}
public void ReceiveFrame(EthernetFrame frame)
{
// TODO: non blocking
if (stream == null)
{
return;
}
var handle = GCHandle.Alloc(frame.Bytes, GCHandleType.Pinned);
try
{
var result = LibCWrapper.Write(stream.Handle, handle.AddrOfPinnedObject(), frame.Bytes.Length);
if (!result)
{
this.Log(LogLevel.Error,
"Error while writing to TUN interface: {0}.", result);
}
}
finally
{
handle.Free();
}
}
private void TransmitLoop(CancellationToken token)
{
while (true)
{
byte[] buffer = null;
if (stream == null)
{
return;
}
try
{
buffer = LibCWrapper.Read(stream.Handle, MTU, 1000, () => token.IsCancellationRequested);
}
catch (ArgumentException)
{
// stream was closed
return;
}
catch (ObjectDisposedException)
{
return;
}
if (token.IsCancellationRequested)
{
return;
}
if (buffer == null || buffer.Length == 0)
{
continue;
}
if (Misc.TryCreateFrameOrLogWarning(this, buffer, out var frame, addCrc: true))
{
FrameReady?.Invoke(frame);
}
}
}
