Merge pull request #399 from Pzixel/unspecified_socket_match_everything

Unspecified socket family matches any single IPAddress

Author: michaelklishin

projects/client/RabbitMQ.Client/src/client/impl/TcpClientAdapter.cs

@@ -26,8 +26,8 @@ public virtual async Task ConnectAsync(string host, int port)
         {
             AssertSocket();
             var adds = await Dns.GetHostAddressesAsync(host).ConfigureAwait(false);
-            var ep = adds.FirstOrDefault(a => a.AddressFamily == sock.AddressFamily);
-            if(ep == default(IPAddress))
+            var ep = TcpClientAdapterHelper.GetMatchingHost(adds, sock.AddressFamily);
+            if (ep == default(IPAddress))
             {
                 throw new ArgumentException("No ip address could be resolved for " + host);
             }

projects/client/RabbitMQ.Client/src/client/impl/TcpClientAdapterHelper.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Net.Sockets;
+
+namespace RabbitMQ.Client
+{
+    public static class TcpClientAdapterHelper
+    {
+        public static IPAddress GetMatchingHost(IReadOnlyCollection<IPAddress> addresses, AddressFamily addressFamily)
+        {
+            var ep = addresses.FirstOrDefault(a => a.AddressFamily == addressFamily);
+            if (ep == null && addresses.Count == 1 && addressFamily == AddressFamily.Unspecified)
+            {
+                return addresses.Single();
+            }
+            return ep;
+        }
+    }
+}

projects/client/Unit/src/unit/TestTcpClientAdapter.cs

@@ -40,6 +40,7 @@
 
 #if !NETFX_CORE
 using System;
+using System.Net;
 using System.Net.Sockets;
 using System.Threading;
 using NUnit.Framework;
@@ -52,14 +53,28 @@ namespace RabbitMQ.Client.Unit
     public class TestTcpClientAdapter
     {
         [Test]
-        public void ConnectAsyncThrowsArgumentExceptionWhenNoAddressForAddressFamilyCanBeFound()
+        public void TcpClientAdapterHelperGetMatchingHostReturnNoAddressIfFamilyDoesNotMatch()
         {
-            var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.IP);
-            var sut = new TcpClientAdapter(socket);
-            Assert.Throws<ArgumentException>(() =>
-            {
-                sut.ConnectAsync("localhost", 5672).GetAwaiter().GetResult();
-            });
+            var address = IPAddress.Parse("127.0.0.1");
+            var matchingAddress = TcpClientAdapterHelper.GetMatchingHost(new[] { address }, AddressFamily.InterNetworkV6);
+            Assert.IsNull(matchingAddress);
+        }
+
+        [Test]
+        public void TcpClientAdapterHelperGetMatchingHostReturnsSingleAddressIfFamilyIsUnspecified()
+        {
+            var address = IPAddress.Parse("1.1.1.1");
+            var matchingAddress = TcpClientAdapterHelper.GetMatchingHost(new[] { address }, AddressFamily.Unspecified);
+            Assert.AreEqual(address, matchingAddress);
+        }
+
+        [Test]
+        public void TcpClientAdapterHelperGetMatchingHostReturnNoAddressIfFamilyIsUnspecifiedAndThereIsNoSingleMatch()
+        {
+            var address = IPAddress.Parse("1.1.1.1");
+            var address2 = IPAddress.Parse("2.2.2.2");
+            var matchingAddress = TcpClientAdapterHelper.GetMatchingHost(new[] { address, address2 }, AddressFamily.Unspecified);
+            Assert.IsNull(matchingAddress);
         }
     }
 }