Question

我对C＃编程非常陌生，我正在开发一个使用TUN-TAP网络适配器的应用程序。

我收到system.IO.IOException错误：连接到系统的设备无法运行。

背景：我已经在我的系统上安装了Openvpn TAP-windows适配器。通过运行一个简单的应用程序，我想获取从同一台机器上运行的服务器出来的数据并以其他形式发送。

要将数据从服务器接收到我的应用程序，我的编码简单如下。

    public static void TunInterfaceThread()
    {            
        const string UsermodeDeviceSpace = "\\\\.\\Global\\";

        // Getting the device GUId
        string devGuid = GetDeviceGuid();
        Console.WriteLine("Device GUID: " + devGuid);

        Console.WriteLine(HumanName(devGuid));

        // Create a win32file for manipulating the TUN/TAP interface 
        IntPtr ptr = CreateFile(UsermodeDeviceSpace + devGuid + ".tap", FileAccess.ReadWrite,
            FileShare.ReadWrite, 0, FileMode.Open, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, IntPtr.Zero);

        // Have Windows consider the interface now connected
        int ioctl_len;
        IntPtr pstatus = Marshal.AllocHGlobal(4);
        Marshal.WriteInt32(pstatus, 1);
        DeviceIoControl(ptr, TAP_CONTROL_CODE(6, METHOD_BUFFERED) /* TAP_IOCTL_SET_MEDIA_STATUS */, pstatus, 4,
                pstatus, 4, out ioctl_len, IntPtr.Zero);

        // Configure with the right IP address + mask and switch to TUN mode (by default the interface runs in TAP mode)
        IntPtr ptun = Marshal.AllocHGlobal(12);
        Marshal.WriteInt32(ptun, 0, 0x0101a8c0);  //192.168.1.1: IP address of the TUN interface
        Marshal.WriteInt32(ptun, 4, 0x0001a8c0);  //192.168.1.0: IP address of the TUN interface's network
        Marshal.WriteInt32(ptun, 8, unchecked((int)0x00ffffff)); // 255.255.255.0: netmask of the TUN interface
        DeviceIoControl(ptr, TAP_CONTROL_CODE(10, METHOD_BUFFERED) /* TAP_IOCTL_CONFIG_TUN */, ptun, 12,
            ptun, 12, out ioctl_len, IntPtr.Zero);

        SafeFileHandle handleValue = null;
        handleValue = new SafeFileHandle(ptr, true);
        Tap = new FileStream(handleValue, FileAccess.ReadWrite, FILE_STREAM_SIZE, true);

        // A buffer used for storing packets as they come in
        // Since this is single threaded, we are handling only one packet at a time 
        byte[] TUNBuffer = new byte[BUFFER_SIZE];

        // Creating a state variable for reading and writing 
        object read_state = new int();
        object write_state = new int();

        // Creating event wait handles, one for reading and the other for writing
        // and initializing them to be signaled automatically 
        ReadWaitObject = new EventWaitHandle(false, EventResetMode.AutoReset);
        WriteWaitObject = new EventWaitHandle(false, EventResetMode.AutoReset);

        // Creating two asynchronous callback functions 
        AsyncCallback readCallback = new AsyncCallback(ReadDataCallback);
        AsyncCallback writeCallback = new AsyncCallback(WriteDataCallback);
        IAsyncResult read_res, write_res;

        int number_of_tun_msgs = 0;
        int number_of_tcpRecv_msgs = 0;
        while (true)
        {
            {
                // Begin an asynchronous read. The callback function readCallback() will be called 
                try
                {                   
                    read_res = Tap.BeginRead(TUNBuffer, 0, BUFFER_SIZE, readCallback, read_state);
                    // blocks the current thread until the read is complete and the event wait handle is signaled with ReadWaitObject.Set()
                    ReadWaitObject.WaitOne();
                }
                catch (Exception e)
                {
                    Console.WriteLine("Tap read exception " + e.ToString());
                    Console.WriteLine(e.Message);
                    Console.WriteLine(e.StackTrace);
                    Console.Read();
                }
            }
           Thread.Sleep(100);
        }
    }

收到数据后，我将其复制到缓冲区并进行其他处理。

这个方法有一段时间，在一段时间后我收到IO异常错误，我不得不重启我的应用程序才能工作。

请帮助我了解IO异常错误背后的主要原因是什么？是我的应用程序有问题还是在机器上运行的TAP-Adapter有一些问题。

FileStream BeginRead system.IO.IOExceptional错误：连接到系统的设备无法正常运行

0 个答案: