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Timeout in socket connection in UWP

I have this code which works fine for project type of Console App (.NET Core).
class Program
{
static void Main(string[] args)
{
var L = new TcpListener(IPAddress.Any, 4994);
L.Start();
using (var C = L.AcceptTcpClientAsync().Result)
{
var S = C.GetStream();
var BR = new BinaryReader(S);
var BW = new BinaryWriter(S);
BW.Write("This is from Console!!!");
Console.WriteLine(BR.ReadString());
}
}
}
But when I use this code in project type of Blank App (Universal Windows) like this:
public MainPage()
{
InitializeComponent();
ThreadPool.RunAsync(foo);
}
static void foo(IAsyncAction operation)
{
var L = new TcpListener(IPAddress.Any, 4994);
L.Start();
using (var C = L.AcceptTcpClientAsync().Result)
{
var S = C.GetStream();
var BR = new BinaryReader(S);
var BW = new BinaryWriter(S);
BW.Write("This is from UWP!!!");
Debug.Write(BR.ReadString());
}
}
It will listen to that port when I check it by netstat but when the client wants to connect this exception will be thrown.
System.Net.Sockets.SocketException: 'A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond'
The UWP App has Private Networks (Client & Server) and Internet (Client & Server) capabilities.
Turning firewall on and off didn't help.
Target Version: Windows 10 Creators Update (10.0; Build 15063)
Client Code which is a WPF application:
using (var C = new TcpClient("127.0.0.1", 4994))
{
var S = C.GetStream();
var BR = new BinaryReader(S);
var BW = new BinaryWriter(S);
BW.Write("This is a test");
MessageBox.Show(BR.ReadString());
}

Debugging UWP & TCP listeners from localhost has always been problematic. Your code is OK and it should work if you try to connect into it from an external computer. The issue you're seeing is quite likely a bug/hyper-v issue/networking problem in the network isolation.
You can check if the network isolation for your app is enabled (it is by default) running the following from command prompt:
CheckNetIsolation.exe LoopbackExempt -s
My recommendation is to use an external computer to make sure that your code is fine (it should be). After that you can try to fight with the network isolation but that can be frustrating.
Here's an another issue where this has been discussed: Unable to access TCP Server inside a Windows Universal Application

C# - Communicate with WinUSB device with LIBUSB

I am trying to communicate with a Nokia Lumia phone(RM-917), over USB using LIBUSING and C#. LIBUSB is able to see the device's information(pid,vid,etc). However, I am not able to successfully write to ANY endpoint, even sending the exact command as the Windows Device Recovery Tool.
According to WinUSB, the write endpoint is EP07, however, this endpoint just times out. I have tried every other endpoint, and all of these fail.
`
public void initDevice()
{
if(this.lumiaDevice == null)
{
throw new Exception("LumiaPhoneManager does not have a selected device");
}
UsbDeviceFinder MyUsbFinder = new UsbDeviceFinder(0x0421, 0x0661);
MyUsbDevice = UsbDevice.OpenUsbDevice(MyUsbFinder);
IUsbDevice wholeUsbDevice = MyUsbDevice as IUsbDevice;
if (!ReferenceEquals(wholeUsbDevice, null))
{
// This is a "whole" USB device. Before it can be used,
// the desired configuration and interface must be selected.
// Select config #1
wholeUsbDevice.SetConfiguration(1);
// Claim interface #0.
wholeUsbDevice.ClaimInterface(1);
}
if (this.writer == null)
{
writer = MyUsbDevice.OpenEndpointWriter(WriteEndpointID.Ep07);
}
}
public void readPCode()
{
currentID++;
var _x = new jsonPkt();
ErrorCode ec = ErrorCode.None;
int bytesWritten;
_x.id = this.currentID + 1;
_x.method = "ReadProductCode";
string value = #"{""jsonrpc"":""<JSONRPC>"",""id"":<ID>,""method"":""<METHOD>"",""params"":null}";
value = value.Replace("<JSONRPC>", "2.0");
value = value.Replace("<ID>", currentID.ToString());
value = value.Replace("<METHOD>", _x.method.ToString());
ec = writer.Write(Encoding.Default.GetBytes(value), 8000, out bytesWritten);
currentID++;
if (ec != ErrorCode.None) throw new Exception(UsbDevice.LastErrorString);
byte[] readBuffer = new byte[1024];
while (ec == ErrorCode.None)
{
int bytesRead;
// If the device hasn't sent data in the last 100 milliseconds,
// a timeout error (ec = IoTimedOut) will occur.
ec = reader.Read(readBuffer, 100, out bytesRead);
// if (bytesRead == 0) throw new Exception("No more bytes!");
// Write that output to the console.
this.rtb.Text += Encoding.Default.GetString(readBuffer, 0, bytesRead).ToString() + "\n";
}
}

Found the solution
Debugged the OEM software and found the program was using a different path to the USB device. After that I was getting access denied errors, which was solved by moving the project to a different drive. For reasons unknown, when the program runs on c drive, the CreateFile function fails with access denied

Its possible that to activate write, you need to send some class specific control request first. You mentioned that windows device recovery tool is able to write.
You can install USB packet sniffer software in your windows PC and then use the device manager to write some data to the device. Packet sniffer tool will be able to capture all the packets sent to the device.
This way you can see the exact device requests which are required to enable write operation.
Analyzer software - http://www.usblyzer.com/
Please try this way to resolve your problem.
PS- I am assuming you do not have a hardware USB packet analyzer like Lecroy advisor or Beagle. Software packet sniffer should be fine since the host is a PC.

UWP/C# - Issue with AQS and USB Devices

I have an issue with a UWP app that I am trying to write. I am connecting to a custom embedded USB Bulk device that I have programmed (it is actually an out of the box example from Cypress Semiconductor). I am using the WinUSB.sys driver using the embedded MS OS string in the device to allow the device to be used with out having to write a custom INF file to call the WinUSB.sys driver.
In my code, I am using the UsbDevice.GetDeviceSelector method to return an AQS that can then be passed into DeviceInformation.FindAllAsync to begin communicating with the device in my app. I have confirmed that the device shows up in the device manager without any issues, and I have checked in the registry to ensure that it has an Interface GUID. I have a screenshot from USBViewer to show the configuration of the device. This method for finding and connecting with USB devices is from this MSDN example found here.
When I use the UsbDevice.GetDeviceSelector method, it returns a GUID that is not associated with this device. The GUID that it returns is actually associated with Lumia Phones (DEE824EF-729B-4A0E-9C14-B7117D33A817). Because of this, it does not find my device connected to the system.
To troubleshoot, I have both called the DeviceInformation.FindAllAsync with out any arguments to see if my device is listed, and it does find the device (amongst over 1000 other devices that have been connected ever to my machine). I then wrote a custom AQS string without the help of the GetDeviceSelector method, starting with just the GUID. Doing this returned 27 devices, but when I tried to add the VID and PID to this AQS string, nothing returned.
I have also made sure that the device that I want to use is listed in the app manifest by its appropriate VID and PID as this is required for a device with a Custom Class of 0xFF. I have used the Custom USB UWP device example and it can find the device, though it uses a completely different method with a device picker, which I will go to if needed, but this is not my desire as it makes that part of the app not as clean of a solution.
I have posted this question over in the MSDN forums here with more information, but I have not gotten a lot of engagement there. Any help would be appreciated. I know that I must be missing something simple.
Adam
private async void button_Click(object sender, RoutedEventArgs e)
{
//UInt32 vid = 0x04B4;
//UInt32 pid = 0x00F0;
UInt32 vid = uint.Parse(textBox1.Text, System.Globalization.NumberStyles.HexNumber);
UInt32 pid = UInt32.Parse(textBox2.Text, System.Globalization.NumberStyles.HexNumber);
Guid winusbInterfaceGuid = new Guid("a5dcbf10-6530-11d2-901f-00c04fb951ed");
//string aqs = UsbDevice.GetDeviceSelector(vid, pid);
string aqs = UsbDevice.GetDeviceSelector(winusbInterfaceGuid);
var myDevices = await DeviceInformation.FindAllAsync(aqs, null);
//var myDevices = await DeviceInformation.FindAllAsync();
var myDevicesCount = myDevices.Count;
if (myDevicesCount >= 1)
{
textBlock2.Text = "Device Found";
} else
{
textBlock2.Text = "Searching";
await Task.Delay(1000);
textBlock2.Text = "looking for device";
}
}

just dropped you a mail asking about progress (I think, had to guess your mail address), but now it seems I found a solution myself. Please see my answer on UWP app cannot find/connect to USB device
In short, you have to create an inf for installing the winusb driver. I have no clue why, but that did the trick for me (and someone else, see Cannot create UsbDevice from DeviceInformation.Id)

The Guid DEE824EF-729B-4A0E-9C14-B7117D33A817 is actually the standard WinUSB Guid. I don't think it has anything to do with Lumia Phones. I don't know why it is not documented anywhere. I think that the Guid a5dcbf10-6530-11d2-901f-00c04fb951ed you specified is actually a red herring. I mistakenly used that as well, but it just led me down the garden path. It shows up USB interfaces, but I can't connect to them.
You might want to try this class https://github.com/MelbourneDeveloper/Device.Net/blob/master/src/Usb.Net.UWP/UWPUsbDevice.cs .
Here is how it gets the device:
public async Task<IEnumerable<DeviceDefinition>> GetConnectedDeviceDefinitions(uint? vendorId, uint? productId)
{
var aqsFilter = "System.Devices.InterfaceClassGuid:=\"{DEE824EF-729B-4A0E-9C14-B7117D33A817}\" AND System.Devices.InterfaceEnabled:=System.StructuredQueryType.Boolean#True AND " + $" System.DeviceInterface.WinUsb.UsbVendorId:={vendorId.Value} AND System.DeviceInterface.WinUsb.UsbProductId:={productId.Value}";
var deviceInformationCollection = await wde.DeviceInformation.FindAllAsync(aqsFilter).AsTask();
//TODO: return the vid/pid if we can get it from the properties. Also read/write buffer size
var deviceIds = deviceInformationCollection.Select(d => new DeviceDefinition { DeviceId = d.Id, DeviceType = DeviceType.Usb }).ToList();
return deviceIds;
}
This sample connects to a device and I think you'll be able to connect to the device in the same way:
private static async Task InitializeTrezor()
{
//Register the factory for creating Usb devices. This only needs to be done once.
UWPUsbDeviceFactory.Register();
//Register the factory for creating Usb devices. This only needs to be done once.
UWPHidDeviceFactory.Register();
//Note: other custom device types could be added here
//Define the types of devices to search for. This particular device can be connected to via USB, or Hid
var deviceDefinitions = new List<DeviceDefinition>
{
new DeviceDefinition{ DeviceType= DeviceType.Hid, VendorId= 0x534C, ProductId=0x0001, Label="Trezor One Firmware 1.6.x" },
new DeviceDefinition{ DeviceType= DeviceType.Usb, VendorId= 0x1209, ProductId=0x53C1, ReadBufferSize=64, WriteBufferSize=64, Label="Trezor One Firmware 1.7.x" },
new DeviceDefinition{ DeviceType= DeviceType.Usb, VendorId= 0x1209, ProductId=0x53C0, ReadBufferSize=64, WriteBufferSize=64, Label="Model T" }
};
//Get the first available device and connect to it
var devices = await DeviceManager.Current.GetDevices(deviceDefinitions);
var trezorDevice = devices.FirstOrDefault();
await trezorDevice.InitializeAsync();
//Create a buffer with 3 bytes (initialize)
var buffer = new byte[64];
buffer[0] = 0x3f;
buffer[1] = 0x23;
buffer[2] = 0x23;
//Write the data to the device
await trezorDevice.WriteAsync(buffer);
//Read the response
var readBuffer = await trezorDevice.ReadAsync();
}
If you connect to the device in this way, you'll get Windows classic, and Android support for free with Device.Net (https://github.com/MelbourneDeveloper/Device.Net)

With Device.net's DeviceManager.Current.GetDevices(deviceDefinitions) using .NET 5 I can't find any device connected to my win10, which can be easily selected by ManagementObjectSearcher:
public List<ManagementBaseObject> GetLogicalDevices()
{
List<ManagementBaseObject> devices = new List<ManagementBaseObject>();
ManagementObjectCollection collection;
ManagementObjectSearcher seacher = new ManagementObjectSearcher("root\\CIMV2", "SELECT * FROM CIM_LogicalDevice");
collection = seacher.Get();
foreach (var device in collection)
{
devices.Add(device);
}
return devices;
}

Bluetooth GUID in C#

I use C#.Net (feet32 lib) to build a bluetooth server/client tool. I follow the instruction from https://www.youtube.com/watch?v=Xxnpq6ePQMk, but I met a problem of Guid. After I input the Bluetooth Guid that accessed from my laptop ( Device manager -> double click your bluetooth device to open it's properties -> details -> Class Guid), it still cannot connect. I am not sure the method I obtain GUID is correct, or other problems ? Thanks!
Guid mUUID = new Guid("e0cbf06c-cd8b-4647-bb8a-263b43f0f974");
// Guid mUUID = new Guid("be5ef05c-288d-45d7-b786-eb8e0b0d67cc");
bool serverStarted = false;
public void ServerConnectThread()
{
serverStarted = true;
updateUI("server started, wait for client");
BluetoothListener blueListener = new BluetoothListener(mUUID);
blueListener.Start();
BluetoothClient conn = blueListener.AcceptBluetoothClient();
updateUI("Client has connected");
Stream mStream = conn.GetStream();
while (true)
{
//handle server connection
byte[] received = new byte[1024];
mStream.Read(received, 0, received.Length);
updateUI("Received:" + Encoding.ASCII.GetString(received));
}
}

The correct GUID is not class guid but rather its bluetooth service GUID and you would see it from the same list you saw the class GUID . Class GUID and bluetooth service GUID are different.

Guid mUUID = BluetoothService.SerialPort;
Try this instead

Search for WCF service in a LAN?

Is there a way to search for the existence of a given WCF service in any of the computer of a local Network?
For example, I am looking for the Math/Add2Numbers service and I want to know which machines on the LAN provide it, is there any way to do that?

Here is a super simple discovery example. It does not use a config file, it is all c# code, but you can probably port the concepts to a config file.
share this interface between host and client program (copy to each program for now)
[ServiceContract]
public interface IWcfPingTest
{
[OperationContract]
string Ping();
}
put this code in the host program
public class WcfPingTest : IWcfPingTest
{
public const string magicString = "djeut73bch58sb4"; // this is random, just to see if you get the right result
public string Ping() {return magicString;}
}
public void WcfTestHost_Open()
{
string hostname = System.Environment.MachineName;
var baseAddress = new UriBuilder("http", hostname, 7400, "WcfPing");
var h = new ServiceHost(typeof(WcfPingTest), baseAddress.Uri);
// enable processing of discovery messages. use UdpDiscoveryEndpoint to enable listening. use EndpointDiscoveryBehavior for fine control.
h.Description.Behaviors.Add(new ServiceDiscoveryBehavior());
h.AddServiceEndpoint(new UdpDiscoveryEndpoint());
// enable wsdl, so you can use the service from WcfStorm, or other tools.
var smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
smb.MetadataExporter.PolicyVersion = PolicyVersion.Policy15;
h.Description.Behaviors.Add(smb);
// create endpoint
var binding = new BasicHttpBinding(BasicHttpSecurityMode.None);
h.AddServiceEndpoint(typeof(IWcfPingTest) , binding, "");
h.Open();
Console.WriteLine("host open");
}
put this code in the client program
private IWcfPingTest channel;
public Uri WcfTestClient_DiscoverChannel()
{
var dc = new DiscoveryClient(new UdpDiscoveryEndpoint());
FindCriteria fc = new FindCriteria(typeof(IWcfPingTest));
fc.Duration = TimeSpan.FromSeconds(5);
FindResponse fr = dc.Find(fc);
foreach(EndpointDiscoveryMetadata edm in fr.Endpoints)
{
Console.WriteLine("uri found = " + edm.Address.Uri.ToString());
}
// here is the really nasty part
// i am just returning the first channel, but it may not work.
// you have to do some logic to decide which uri to use from the discovered uris
// for example, you may discover "127.0.0.1", but that one is obviously useless.
// also, catch exceptions when no endpoints are found and try again.
return fr.Endpoints[0].Address.Uri;
}
public void WcfTestClient_SetupChannel()
{
var binding = new BasicHttpBinding(BasicHttpSecurityMode.None);
var factory = new ChannelFactory<IWcfPingTest>(binding);
var uri = WcfTestClient_DiscoverChannel();
Console.WriteLine("creating channel to " + uri.ToString());
EndpointAddress ea = new EndpointAddress(uri);
channel = factory.CreateChannel(ea);
Console.WriteLine("channel created");
//Console.WriteLine("pinging host");
//string result = channel.Ping();
//Console.WriteLine("ping result = " + result);
}
public void WcfTestClient_Ping()
{
Console.WriteLine("pinging host");
string result = channel.Ping();
Console.WriteLine("ping result = " + result);
}
on the host, simply call the WcfTestHost_Open() function, then sleep forever or something.
on the client, run these functions. It takes a little while for a host to open, so there are several delays here.
System.Threading.Thread.Sleep(8000);
this.server.WcfTestClient_SetupChannel();
System.Threading.Thread.Sleep(2000);
this.server.WcfTestClient_Ping();
host output should look like
host open
client output should look like
uri found = http://wilkesvmdev:7400/WcfPing
creating channel to http://wilkesvmdev:7400/WcfPing
channel created
pinging host
ping result = djeut73bch58sb4
this is seriously the minimum I could come up with for a discovery example. This stuff gets pretty complex fast.

What you need is WS-Discovery, but unfortunately, this is not included as part of the ws-* extensions in WCF. There are some homegrown implementations of it. Here's a google search for that.
Otherwise, you can implement an enterprise UDDI or registry solution by a third party vendor (like IBM or Microsoft).

You could use UDDI to find it, but if there were multiple instances of the service, how would you decide which instance to use?