add NetworkException

src/libraries/Common/src/System/Net/NetworkErrorHelper.cs

@@ -0,0 +1,26 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Net.Sockets;
+
+namespace System.Net
+{
+    internal static class NetworkErrorHelper
+    {
+        internal static NetworkException MapSocketException(SocketException socketException)
+        {
+            NetworkError error = socketException.SocketErrorCode switch
+            {
+                SocketError.AddressAlreadyInUse => NetworkError.EndPointInUse,
+                SocketError.HostNotFound => NetworkError.HostNotFound,
+                SocketError.ConnectionRefused => NetworkError.ConnectionRefused,
+                SocketError.OperationAborted => NetworkError.OperationAborted,
+                SocketError.ConnectionAborted => NetworkError.ConnectionAborted,
+                SocketError.ConnectionReset => NetworkError.ConnectionReset,
+                _ => NetworkError.Unknown
+            };
+
+            return new NetworkException(error, socketException);
+        }
+    }
+}

src/libraries/System.Net.Http/src/System.Net.Http.csproj

@@ -109,6 +109,8 @@
              Link="Common\System\IO\StreamHelpers.CopyValidation.cs" />
     <Compile Include="$(CommonPath)System\Net\Security\SslClientAuthenticationOptionsExtensions.cs"
              Link="Common\System\Net\Security\SslClientAuthenticationOptionsExtensions.cs" />
+    <Compile Include="$(CommonPath)System\Net\NetworkErrorHelper.cs"
+             Link="Common\System\Net\NetworkErrorHelper.cs" />
     <Compile Include="$(CommonPath)System\IO\DelegatingStream.cs"
              Link="Common\System\IO\DelegatingStream.cs" />
     <Compile Include="$(CommonPath)System\IO\ReadOnlyMemoryStream.cs"

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Connections/SocketConnection.cs

@@ -3,23 +3,25 @@
 
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
+using System.Net.Http;
 using System.Net.Sockets;
+using System.Runtime.ExceptionServices;
 using System.Threading;
 using System.Threading.Tasks;
 
 namespace System.Net.Connections
 {
     internal sealed class SocketConnection : Connection, IConnectionProperties
     {
-        private readonly SocketConnectionNetworkStream _stream;
+        private readonly NetworkStream _stream;
 
         public override EndPoint? RemoteEndPoint => _stream.Socket.RemoteEndPoint;
         public override EndPoint? LocalEndPoint => _stream.Socket.LocalEndPoint;
         public override IConnectionProperties ConnectionProperties => this;
 
         public SocketConnection(Socket socket)
         {
-            _stream = new SocketConnectionNetworkStream(socket, this);
+            _stream = new NetworkStream(socket, ownsSocket: true);
         }
 
         protected override ValueTask CloseAsyncCore(ConnectionCloseMethod method, CancellationToken cancellationToken)
@@ -38,7 +40,11 @@ protected override ValueTask CloseAsyncCore(ConnectionCloseMethod method, Cancel
                     _stream.Socket.Dispose();
                 }
 
-                _stream.DisposeWithoutClosingConnection();
+                _stream.Dispose();
+            }
+            catch (SocketException socketException)
+            {
+                return ValueTask.FromException(ExceptionDispatchInfo.SetCurrentStackTrace(NetworkErrorHelper.MapSocketException(socketException)));
             }
             catch (Exception ex)
             {
@@ -61,41 +67,5 @@ bool IConnectionProperties.TryGet(Type propertyKey, [NotNullWhen(true)] out obje
             property = null;
             return false;
         }
-
-        // This is done to couple disposal of the SocketConnection and the NetworkStream.
-        private sealed class SocketConnectionNetworkStream : NetworkStream
-        {
-            private readonly SocketConnection _connection;
-
-            public SocketConnectionNetworkStream(Socket socket, SocketConnection connection) : base(socket, ownsSocket: true)
-            {
-                _connection = connection;
-            }
-
-            public void DisposeWithoutClosingConnection()
-            {
-                base.Dispose(true);
-            }
-
-            protected override void Dispose(bool disposing)
-            {
-                if (disposing)
-                {
-                    // This will call base.Dispose().
-                    _connection.Dispose();
-                }
-                else
-                {
-                    base.Dispose(disposing);
-                }
-            }
-
-            public override ValueTask DisposeAsync()
-            {
-                // This will call base.Dispose().
-                Dispose(true);
-                return default;
-            }
-        }
     }
 }

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/SocketsHttpConnectionFactory.cs

@@ -79,6 +79,11 @@ public virtual async ValueTask<Connection> EstablishConnectionAsync(HttpRequestM
                 socket.NoDelay = true;
                 return new SocketConnection(socket);
             }
+            catch (SocketException socketException)
+            {
+                socket.Dispose();
+                throw NetworkErrorHelper.MapSocketException(socketException);
+            }
             catch
             {
                 socket.Dispose();

src/libraries/System.Net.Http/tests/FunctionalTests/SocketsHttpHandlerTest.cs

@@ -160,7 +160,9 @@ public async Task CustomConnectionFactory_SyncRequest_Fails()
 
             using HttpClient client = CreateHttpClient(handler);
 
-            await Assert.ThrowsAnyAsync<HttpRequestException>(() => client.GetStringAsync($"http://{Guid.NewGuid():N}.com/foo"));
+            HttpRequestException e = await Assert.ThrowsAnyAsync<HttpRequestException>(() => client.GetStringAsync($"http://{Guid.NewGuid():N}.com/foo"));
+            NetworkException networkException = Assert.IsType<NetworkException>(e.InnerException);
+            Assert.Equal(NetworkError.HostNotFound, networkException.NetworkError);
         }
     }
 

src/libraries/System.Net.Primitives/ref/System.Net.Primitives.cs

@@ -323,6 +323,23 @@ public abstract partial class TransportContext
         protected TransportContext() { }
         public abstract System.Security.Authentication.ExtendedProtection.ChannelBinding? GetChannelBinding(System.Security.Authentication.ExtendedProtection.ChannelBindingKind kind);
     }
+    public enum NetworkError : int
+    {
+        Unknown = 0,
+        EndPointInUse,
+        HostNotFound,
+        ConnectionRefused,
+        OperationAborted,
+        ConnectionAborted,
+        ConnectionReset,
+    }
+    public class NetworkException : System.IO.IOException
+    {
+        public NetworkException(NetworkError error, Exception? innerException = null) { }
+        public NetworkException(string message, NetworkError error, Exception? innerException = null) { }
+        protected NetworkException(System.Runtime.Serialization.SerializationInfo serializationInfo, System.Runtime.Serialization.StreamingContext streamingContext) { }
+        public NetworkError NetworkError { get { throw null; } }
+    }
 }
 namespace System.Net.Cache
 {

src/libraries/System.Net.Primitives/src/Resources/Strings.resx

@@ -114,4 +114,25 @@
   <data name="bad_endpoint_string" xml:space="preserve">
     <value>An invalid IPEndPoint was specified.</value>
   </data>
+  <data name="networkerror_unknown" xml:space="preserve">
+    <value>An unknown network error occurred.</value>
+  </data>
+  <data name="networkerror_addressinuse" xml:space="preserve">
+    <value>The requested EndPoint is already in use.</value>
+  </data>
+  <data name="networkerror_connectionrefused" xml:space="preserve">
+    <value>No connection could be made because the remote host actively refused it.</value>
+  </data>
+  <data name="networkerror_hostnotfound" xml:space="preserve">
+    <value>No such host is known.</value>
+  </data>
+  <data name="networkerror_operationaborted" xml:space="preserve">
+    <value>The operation was aborted by the user.</value>
+  </data>
+  <data name="networkerror_connectionaborted" xml:space="preserve">
+    <value>The connection was aborted by the local host.</value>
+  </data>
+  <data name="networkerror_connectionreset" xml:space="preserve">
+    <value>The connection was forcibly closed by the remote host.</value>
+  </data>
 </root>

src/libraries/System.Net.Primitives/src/System.Net.Primitives.csproj

@@ -34,6 +34,8 @@
     <Compile Include="System\Net\IWebProxy.cs" />
     <Compile Include="System\Net\NetEventSource.Primitives.cs" />
     <Compile Include="System\Net\NetworkCredential.cs" />
+    <Compile Include="System\Net\NetworkException.cs" />
+    <Compile Include="System\Net\NetworkError.cs" />
     <Compile Include="System\Net\TransportContext.cs" />
     <Compile Include="System\Net\SocketException.cs" />
     <Compile Include="System\Net\SecureProtocols\NegotiateEnumTypes.cs" />

src/libraries/System.Net.Primitives/src/System/Net/NetworkError.cs

@@ -0,0 +1,30 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Net
+{
+    /// <summary>Defines a set of error codes for use with <see cref='System.Net.NetworkException'/>.</summary>
+    public enum NetworkError : int
+    {
+        /// <summary>An unknown network error occurred.</summary>
+        Unknown = 0,
+
+        /// <summary>The requested EndPoint is already in use.</summary>
+        EndPointInUse,
+
+        /// <summary>No such host is known.</summary>
+        HostNotFound,
+
+        /// <summary>No connection could be made because the remote host actively refused it.</summary>
+        ConnectionRefused,
+
+        /// <summary>The operation was aborted by the user.</summary>
+        OperationAborted,
+
+        /// <summary>The connection was aborted by the local host.</summary>
+        ConnectionAborted,
+
+        /// <summary>The connection was forcibly closed by the remote host.</summary>
+        ConnectionReset,
+    }
+}

src/libraries/System.Net.Primitives/src/System/Net/NetworkException.cs

@@ -0,0 +1,52 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.IO;
+using System.Runtime.Serialization;
+
+namespace System.Net
+{
+    /// <summary>Provides socket exceptions to the application.</summary>
+    [Serializable]
+    public class NetworkException : IOException
+    {
+        /// <summary>Creates a new instance of the <see cref='System.Net.NetworkException'/> class with the specified error code.</summary>
+        public NetworkException(NetworkError error, Exception? innerException = null)
+            : this(GetExceptionMessage(error), error, innerException) {}
+
+        /// <summary>Creates a new instance of the <see cref='System.Net.NetworkException'/> class with the specified error code and message.</summary>
+        public NetworkException(string message, NetworkError error, Exception? innerException = null)
+            : base(message, innerException)
+        {
+            NetworkError = error;
+        }
+
+        /// <summary>Creates a new instance of the <see cref='System.Net.NetworkException'/> from serialized data.</summary>
+        protected NetworkException(SerializationInfo serializationInfo, StreamingContext streamingContext)
+            : base(serializationInfo, streamingContext)
+        {
+            NetworkError = (NetworkError)serializationInfo.GetInt32("NetworkError");
+        }
+
+        /// <summary>Populates the serialization data for this object.</summary>
+        public override void GetObjectData(SerializationInfo serializationInfo, StreamingContext streamingContext)
+        {
+            base.GetObjectData(serializationInfo, streamingContext);
+            serializationInfo.AddValue("NetworkError", (int)NetworkError);
+        }
+
+        /// <summary>Returns the specific kind of error.</summary>
+        public NetworkError NetworkError { get; }
+
+        private static string GetExceptionMessage(NetworkError error) => error switch
+        {
+            NetworkError.EndPointInUse => SR.networkerror_addressinuse,
+            NetworkError.HostNotFound => SR.networkerror_hostnotfound,
+            NetworkError.ConnectionRefused => SR.networkerror_connectionrefused,
+            NetworkError.ConnectionAborted => SR.networkerror_connectionaborted,
+            NetworkError.ConnectionReset => SR.networkerror_connectionreset,
+            NetworkError.OperationAborted => SR.networkerror_operationaborted,
+            _ => SR.networkerror_unknown
+        };
+    }
+}

src/libraries/System.Net.Primitives/tests/FunctionalTests/NetworkExceptionTest.cs

@@ -0,0 +1,34 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Xunit;
+
+namespace System.Net.Primitives.Functional.Tests
+{
+    public static class NetworkExceptionTest
+    {
+        [Fact]
+        public static void Create_AllErrorCodes_Success()
+        {
+            foreach (NetworkError error in Enum.GetValues(typeof(NetworkError)))
+            {
+                NetworkException e = new NetworkException(error);
+                Assert.Equal(error, e.NetworkError);
+                Assert.Null(e.InnerException);
+                Assert.NotNull(e.Message);
+            }
+        }
+
+        [Fact]
+        public static void Create_InnerExceptionAndMessage_Success()
+        {
+            const string Message = "Hello";
+            Exception inner = new Exception();
+
+            NetworkException e = new NetworkException(Message, NetworkError.Unknown, inner);
+
+            Assert.Equal(inner, e.InnerException);
+            Assert.Equal(Message, e.Message);
+        }
+    }
+}

src/libraries/System.Net.Primitives/tests/FunctionalTests/System.Net.Primitives.Functional.Tests.csproj

@@ -20,6 +20,7 @@
     <Compile Include="IPEndPointParsing.cs" />
     <Compile Include="IPEndPointTest.cs" />
     <Compile Include="NetworkCredentialTest.cs" />
+    <Compile Include="NetworkExceptionTest.cs" />
     <Compile Include="SocketAddressTest.cs" />
     <Compile Include="LoggingTest.cs" />
     <Compile Include="RequestCachePolicyTest.cs" />

src/libraries/System.Net.Sockets/src/System.Net.Sockets.csproj

@@ -93,6 +93,8 @@
              Link="Common\System\Net\Sockets\ProtocolType.cs" />
     <Compile Include="$(CommonPath)System\Net\Sockets\SocketType.cs"
              Link="Common\System\Net\Sockets\SocketType.cs" />
+    <Compile Include="$(CommonPath)System\Net\NetworkErrorHelper.cs"
+             Link="Common\System\Net\NetworkErrorHelper.cs" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
     <!-- Windows: CoreCLR -->