Bug 49161 - TCPClient ExclusiveAddressUse = false socket bind error
Summary: TCPClient ExclusiveAddressUse = false socket bind error
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: 4.8.0 (C9)
Hardware: Other Linux
: --- normal
Target Milestone: Untriaged
Assignee: Marek Safar
Depends on:
Reported: 2016-12-06 23:02 UTC by Phil
Modified: 2016-12-09 01:35 UTC (History)
3 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Phil 2016-12-06 23:02:44 UTC
I have a simple .Net test process that declares a new TcpClient on a local port and then tries to connect to it.  This compiles and runs on Windows but fails to run under Mono 4.6.2 on a Raspberry Pi 3.  The error is:

System.InvalidOperationException: Bind has already been called for this socket
  at System.Net.Sockets.Socket.set_ExclusiveAddressUse (System.Boolean value) [0x00011] in <bd46d4d4f7964dfa9beea098499ab597>:0
  at System.Net.Sockets.TcpClient.set_ExclusiveAddressUse (System.Boolean value) [0x00000] in <bd46d4d4f7964dfa9beea098499ab597>:0
  at Test.Module1.Main () [0x00008] in <73e78983e4964489ba5dd5feb2953471>:0

If I comment out the clientSocket.ExclusiveAddressUse = False line then it will run as expected however I need to set ExclusiveAddressUse = False as multiple sockets connect to this port.  My process is connecting to a server running locally on the same machine.

Test code to replicate this is:

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
static class Module1

	public static void Main()
		// Declare client socket and client stream to get data
		TcpClient clientSocket = new TcpClient();

		try {
			// Connect to socket
			clientSocket.ExclusiveAddressUse = false;
			clientSocket.LingerState.LingerTime = 0;
			clientSocket.Connect("", 30005);
		} catch (Exception ex) {



I wan't sure which component to assign this to hence my choice of misc.  Apologies if that is wrong.
Comment 1 Ludovic Henry 2016-12-07 16:08:54 UTC
I can reproduce it, but it is fixed on master. I will track down where it was fixed, to try to backport to 4.8
Comment 2 Ludovic Henry 2016-12-07 19:20:04 UTC
This is fixed in master because we imported TcpClient from referencesource, which is not in 4.8 and before.

The test case to reproduce is the following:

> using System;
> using System.Net.Sockets;
> class Driver
> {
> 	public static void Main ()
> 	{
> 		using (TcpClient client = new TcpClient ()) {
> 			client.ExclusiveAddressUse = false;
> 		}
> 	}
> }
Comment 3 Phil 2016-12-08 08:48:04 UTC
I've just installed 4.9.0 from the nightly build and can confirm that my test process works so this bug can be closed.  I couldn't find 4.8 to install.

Any idea how long it will be before 4.8 or 4.9 are released ?  Or is there a way to patch the current 4.6 version ?
Comment 4 Marek Safar 2016-12-09 01:35:30 UTC
Fixed in master.

We don't have plans to backport it to earlier versions