NetworkStream now rejects non-stream sockets (#418)

***NO_CI***

Author: josesimoes

Tests/SocketTests/NetworkStreamTests.cs

@@ -0,0 +1,124 @@
+//
+// Copyright (c) .NET Foundation and Contributors
+// See LICENSE file in the project root for full license information.
+//
+
+using nanoFramework.TestFramework;
+using System;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+
+namespace NFUnitTestSocketTests
+{
+    [TestClass]
+    public class NetworkStreamTests
+    {
+        [Setup]
+        public void SetupConnectToEthernetTests()
+        {
+            // Comment next line to run the tests on a real hardware
+            Assert.SkipTest("Skipping tests using nanoCLR Win32 in a pipeline");
+        }
+
+        [TestMethod]
+        public void Ctor_NullSocket_ThrowsArgumentNullException()
+        {
+            Assert.ThrowsException(typeof(ArgumentNullException), () =>
+            {
+                _ = new NetworkStream(null);
+            });
+
+            Assert.ThrowsException(typeof(ArgumentNullException), () =>
+            {
+                _ = new NetworkStream(null, true);
+            });
+        }
+
+        [TestMethod]
+        public void Ctor_UnconnectedStreamSocket_ThrowsIOException()
+        {
+            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+
+            try
+            {
+                Assert.ThrowsException(typeof(IOException), () =>
+                {
+                    _ = new NetworkStream(socket);
+                });
+
+                Assert.ThrowsException(typeof(IOException), () =>
+                {
+                    _ = new NetworkStream(socket, false);
+                });
+            }
+            finally
+            {
+                socket.Close();
+            }
+        }
+
+        [TestMethod]
+        public void Ctor_ConnectedDgramSocket_ThrowsIOException()
+        {
+            SocketPair testSockets = new SocketPair(ProtocolType.Udp, SocketType.Dgram);
+
+            try
+            {
+                testSockets.Startup(0, 0);
+
+                // a connected datagram socket has a remote endpoint, so this exercises the socket type check
+                testSockets.socketClient.Connect(testSockets.epServer);
+
+                Assert.ThrowsException(typeof(IOException), () =>
+                {
+                    _ = new NetworkStream(testSockets.socketClient);
+                });
+
+                Assert.ThrowsException(typeof(IOException), () =>
+                {
+                    _ = new NetworkStream(testSockets.socketClient, false);
+                });
+            }
+            finally
+            {
+                testSockets.TearDown();
+            }
+        }
+
+        [TestMethod]
+        public void Ctor_ConnectedStreamSocket_Succeeds()
+        {
+            SocketPair testSockets = new SocketPair(ProtocolType.Tcp, SocketType.Stream);
+            Socket acceptedSocket = null;
+
+            try
+            {
+                testSockets.Startup(0, 0);
+                testSockets.socketServer.Listen(1);
+                testSockets.socketClient.Connect(testSockets.epServer);
+                acceptedSocket = testSockets.socketServer.Accept();
+
+                NetworkStream clientStream = new NetworkStream(testSockets.socketClient);
+                NetworkStream serverStream = new NetworkStream(acceptedSocket, true);
+
+                clientStream.Write(testSockets.bufSend, 0, testSockets.bufSend.Length);
+
+                int bytesRead = serverStream.Read(testSockets.bufReceive, 0, testSockets.bufReceive.Length);
+
+                testSockets.AssertDataReceived(bytesRead);
+
+                clientStream.Dispose();
+
+                // server stream owns the accepted socket, so disposing it closes the socket
+                serverStream.Dispose();
+                acceptedSocket = null;
+            }
+            finally
+            {
+                acceptedSocket?.Close();
+                testSockets.TearDown();
+            }
+        }
+    }
+}

Tests/SocketTests/SocketTests.nfproj

@@ -27,6 +27,7 @@
   <Import Project="$(NanoFrameworkProjectSystemPath)NFProjectSystem.props" Condition="Exists('$(NanoFrameworkProjectSystemPath)NFProjectSystem.props')" />
   <ItemGroup>
     <Compile Include="CompanionClient.cs" />
+    <Compile Include="NetworkStreamTests.cs" />
     <Compile Include="SocketOptionsTests.cs" />
     <Compile Include="SocketPair.cs" />
     <Compile Include="SocketExceptionsTests.cs" />

nanoFramework.System.Net/Security/SslStream.cs

@@ -47,18 +47,15 @@ public class SslStream : NetworkStream
         /// Initializes a new instance of the SslStream class using the specified Socket.
         /// </summary>
         /// <param name="socket">A valid socket that currently has a TCP connection.</param>
+        /// <exception cref="ArgumentNullException"><paramref name="socket"/> is <see langword="null"/>.</exception>
+        /// <exception cref="IOException"><paramref name="socket"/> is not connected. -or- The <see cref="Socket.SocketType"/> property of <paramref name="socket"/> is not <see cref="SocketType.Stream"/>.</exception>
         /// <remarks>
         /// The SslStream maintains the lifetime of the socket. When the SslStream object is disposed, 
         /// the underlying TCP socket will be closed.
         /// </remarks>
         public SslStream(Socket socket)
             : base(socket, false)
         {
-            if (SocketType.Stream != (SocketType)_socketType)
-            {
-                throw new NotSupportedException();
-            }
-
             _sslContext = -1;
             _isServer = false;