[Client] Fix endpoint handling (#1999)

* Fix endpoint handling

* Fix different behavior for Mono framework.

* Restore old properties to avoid breaking changes

.github/workflows/ReleaseNotes.md

@@ -1,3 +1,4 @@
+* [Client] Fix _None of the discovered or specified addresses match the socket address family._ (#1997).
 * [Client] Remove the obsolete attribute from the _WithConnectionUri_ methods (#1979).
 
 * All nuget packages are now signed.

Source/MQTTnet.Tests/Internal/CrossPlatformSocket_Tests.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Net.Sockets;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -17,7 +18,7 @@ namespace MQTTnet.Tests.Internal
         [TestMethod]
         public async Task Connect_Send_Receive()
         {
-            var crossPlatformSocket = new CrossPlatformSocket();
+            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
             await crossPlatformSocket.ConnectAsync("www.google.de", 80, CancellationToken.None);
 
             var requestBuffer = Encoding.UTF8.GetBytes("GET / HTTP/1.1\r\nHost: www.google.de\r\n\r\n");
@@ -36,7 +37,7 @@ namespace MQTTnet.Tests.Internal
         [ExpectedException(typeof(OperationCanceledException))]
         public async Task Try_Connect_Invalid_Host()
         {
-            var crossPlatformSocket = new CrossPlatformSocket();
+            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
 
             var cancellationToken = new CancellationTokenSource(TimeSpan.FromSeconds(5));
             cancellationToken.Token.Register(() => crossPlatformSocket.Dispose());
@@ -65,7 +66,7 @@ namespace MQTTnet.Tests.Internal
         [TestMethod]
         public void Set_Options()
         {
-            var crossPlatformSocket = new CrossPlatformSocket();
+            var crossPlatformSocket = new CrossPlatformSocket(ProtocolType.Tcp);
 
             Assert.IsFalse(crossPlatformSocket.ReuseAddress);
             crossPlatformSocket.ReuseAddress = true;

Source/MQTTnet/Client/Options/MqttClientOptionsBuilder.cs

@@ -79,11 +79,26 @@ namespace MQTTnet.Client
                     {
                         if (_port.HasValue)
                         {
-                            _remoteEndPoint = new DnsEndPoint(dns.Host, _port.Value);
+                            _remoteEndPoint = new DnsEndPoint(dns.Host, _port.Value, dns.AddressFamily);
                         }
                         else
                         {
-                            _remoteEndPoint = new DnsEndPoint(dns.Host, tlsOptions?.UseTls == false ? MqttPorts.Default : MqttPorts.Secure);
+                            _remoteEndPoint = new DnsEndPoint(dns.Host, tlsOptions?.UseTls == false ? MqttPorts.Default : MqttPorts.Secure, dns.AddressFamily);
+                        }
+                    }
+                }
+
+                if (_remoteEndPoint is IPEndPoint ip)
+                {
+                    if (ip.Port == 0)
+                    {
+                        if (_port.HasValue)
+                        {
+                            _remoteEndPoint = new IPEndPoint(ip.Address, _port.Value);
+                        }
+                        else
+                        {
+                            _remoteEndPoint = new IPEndPoint(ip.Address, tlsOptions?.UseTls == false ? MqttPorts.Default : MqttPorts.Secure);
                         }
                     }
                 }
@@ -352,13 +367,18 @@ namespace MQTTnet.Client
             return this;
         }
 
-        public MqttClientOptionsBuilder WithTcpServer(string server, int? port = null)
+        public MqttClientOptionsBuilder WithTcpServer(string host, int? port = null, AddressFamily addressFamily = AddressFamily.Unspecified)
         {
+            if (host == null)
+            {
+                throw new ArgumentNullException(nameof(host));
+            }
+
             _tcpOptions = new MqttClientTcpOptions();
 
             // The value 0 will be updated when building the options.
             // This a backward compatibility feature.
-            _remoteEndPoint = new DnsEndPoint(server, port ?? 0);
+            _remoteEndPoint = new DnsEndPoint(host, port ?? 0, addressFamily);
             _port = port;
 
             return this;

Source/MQTTnet/Client/Options/MqttClientTcpOptions.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using System.Net;
 using System.Net.Sockets;
 
@@ -20,6 +21,12 @@ namespace MQTTnet.Client
         /// </summary>
         public bool? DualMode { get; set; }
 
+        [Obsolete("Use RemoteEndpoint or MqttClientOptionsBuilder instead.")]
+        public int? Port { get; set; }
+
+        [Obsolete("Use RemoteEndpoint or MqttClientOptionsBuilder instead.")]
+        public string Server { get; set; }
+
         public LingerOption LingerState { get; set; } = new LingerOption(true, 0);
 
         /// <summary>

Source/MQTTnet/Implementations/CrossPlatformSocket.cs

@@ -31,11 +31,11 @@ namespace MQTTnet.Implementations
 #endif
         }
 
-        public CrossPlatformSocket()
+        public CrossPlatformSocket(ProtocolType protocolType)
         {
             // Having this constructor is important because avoiding the address family as parameter
             // will make use of dual mode in the .net framework.
-            _socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
+            _socket = new Socket(SocketType.Stream, protocolType);
 
 #if !NET5_0_OR_GREATER
             _socketDisposeAction = _socket.Dispose;
@@ -202,9 +202,28 @@ namespace MQTTnet.Implementations
                 using (cancellationToken.Register(_socketDisposeAction))
                 {
 #if NET452 || NET461
-                    await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, endPoint, null).ConfigureAwait(false);
+                    // This is a fix for Mono which behaves differently than dotnet.
+                    // The connection will not be established when the DNS endpoint is used.
+                    if (endPoint is DnsEndPoint dns && dns.AddressFamily == AddressFamily.Unspecified)
+                    {
+                        await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, dns.Host, dns.Port, null).ConfigureAwait(false);
+                    }
+                    else
+                    {
+                        await Task.Factory.FromAsync(_socket.BeginConnect, _socket.EndConnect, endPoint, null).ConfigureAwait(false);
+                    }
 #else
-                    await _socket.ConnectAsync(endPoint).ConfigureAwait(false);
+
+                    // This is a fix for Mono which behaves differently than dotnet.
+                    // The connection will not be established when the DNS endpoint is used.
+                    if (endPoint is DnsEndPoint dns && dns.AddressFamily == AddressFamily.Unspecified)
+                    {
+                        await _socket.ConnectAsync(dns.Host, dns.Port).ConfigureAwait(false);
+                    }
+                    else
+                    {
+                        await _socket.ConnectAsync(endPoint).ConfigureAwait(false);
+                    }
 #endif
                 }
 #endif

Source/MQTTnet/Implementations/MqttTcpChannel.cs

@@ -16,6 +16,7 @@ using MQTTnet.Channel;
 using MQTTnet.Client;
 using MQTTnet.Exceptions;
 using MQTTnet.Internal;
+using MQTTnet.Protocol;
 
 namespace MQTTnet.Implementations
 {
@@ -63,7 +64,7 @@ namespace MQTTnet.Implementations
             {
                 if (_tcpOptions.AddressFamily == AddressFamily.Unspecified)
                 {
-                    socket = new CrossPlatformSocket();
+                    socket = new CrossPlatformSocket(_tcpOptions.ProtocolType);
                 }
                 else
                 {
@@ -98,6 +99,29 @@ namespace MQTTnet.Implementations
                     socket.DualMode = _tcpOptions.DualMode.Value;
                 }
 
+                // This block is only for backward compatibility.
+                if (_tcpOptions.RemoteEndpoint == null && !string.IsNullOrEmpty(_tcpOptions.Server))
+                {
+                    int port;
+                    if (_tcpOptions.Port.HasValue)
+                    {
+                        port = _tcpOptions.Port.Value;
+                    }
+                    else
+                    {
+                        if (_tcpOptions.TlsOptions?.UseTls == true)
+                        {
+                            port = MqttPorts.Secure;
+                        }
+                        else
+                        {
+                            port = MqttPorts.Default;
+                        }
+                    }
+
+                    _tcpOptions.RemoteEndpoint = new DnsEndPoint(_tcpOptions.Server, port, AddressFamily.Unspecified);
+                }
+
                 await socket.ConnectAsync(_tcpOptions.RemoteEndpoint, cancellationToken).ConfigureAwait(false);
 
                 cancellationToken.ThrowIfCancellationRequested();