Respect offset in Socket.ReceiveMessageFrom(saea) on Windows (dotnet#…

…47642) Fixes dotnet#47637, and adds ReceiveSent_UDP_Success test to both ReceiveFrom and ReceiveMessageFrom
Nisden · Feb 2, 2021 · f47c1b5 · f47c1b5
1 parent 9104f3c
commit f47c1b5
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Showing 3 changed files with 46 additions and 4 deletions.
diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEventArgs.Windows.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEventArgs.Windows.cs
@@ -563,7 +563,7 @@ internal unsafe SocketError DoOperationReceiveMessageFrom(Socket socket, SafeSoc
                     Debug.Assert(_singleBufferHandleState == SingleBufferHandleState.None);
                     _singleBufferHandleState = SingleBufferHandleState.InProcess;
 
-                    _wsaRecvMsgWSABufferArrayPinned[0].Pointer = (IntPtr)bufferPtr;
+                    _wsaRecvMsgWSABufferArrayPinned[0].Pointer = (IntPtr)bufferPtr + _offset;
                     _wsaRecvMsgWSABufferArrayPinned[0].Length = _count;
                     wsaRecvMsgWSABufferArray = _wsaRecvMsgWSABufferArrayPinned;
                     wsaRecvMsgWSABufferCount = 1;

diff --git a/src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveFrom.cs b/src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveFrom.cs
@@ -83,6 +83,48 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
             }
         }
 
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public async Task ReceiveSent_UDP_Success(bool ipv4)
+        {
+            const int Offset = 10;
+            const int DatagramSize = 256;
+            const int DatagramsToSend = 16;
+
+            IPAddress address = ipv4 ? IPAddress.Loopback : IPAddress.IPv6Loopback;
+            using Socket receiver = new Socket(address.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
+            using Socket sender = new Socket(address.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
+
+            ConfigureNonBlocking(sender);
+            ConfigureNonBlocking(receiver);
+
+            receiver.BindToAnonymousPort(address);
+            sender.BindToAnonymousPort(address);
+
+            byte[] sendBuffer = new byte[DatagramSize];
+            var receiveInternalBuffer = new byte[DatagramSize + Offset];
+            var emptyBuffer = new byte[Offset];
+            ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
+
+            Random rnd = new Random(0);
+
+            IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);
+
+            for (int i = 0; i < DatagramsToSend; i++)
+            {
+                rnd.NextBytes(sendBuffer);
+                sender.SendTo(sendBuffer, receiver.LocalEndPoint);
+
+                SocketReceiveFromResult result = await ReceiveFromAsync(receiver, receiveBuffer, remoteEp);
+
+                Assert.Equal(DatagramSize, result.ReceivedBytes);
+                AssertExtensions.SequenceEqual(emptyBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, 0, Offset));
+                AssertExtensions.SequenceEqual(sendBuffer, new ReadOnlySpan<byte>(receiveInternalBuffer, Offset, DatagramSize));
+                Assert.Equal(sender.LocalEndPoint, result.RemoteEndPoint);
+            }
+        }
+
         [Theory]
         [InlineData(true)]
         [InlineData(false)]

diff --git a/src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs b/src/libraries/System.Net.Sockets/tests/FunctionalTests/ReceiveMessageFrom.cs
@@ -52,10 +52,9 @@ public async Task ReceiveSent_TCP_Success(bool ipv6)
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
-        public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
+        public async Task ReceiveSent_UDP_Success(bool ipv4)
         {
-            // [ActiveIssue("https://github.com/dotnet/runtime/issues/47637")]
-            int Offset = UsesSync || !PlatformDetection.IsWindows ? 10 : 0;
+            const int Offset = 10;
             const int DatagramSize = 256;
             const int DatagramsToSend = 16;
 
@@ -74,6 +73,7 @@ public async Task ReceiveSentMessages_UDP_Success(bool ipv4)
             var receiveInternalBuffer = new byte[DatagramSize + Offset];
             var emptyBuffer = new byte[Offset];
             ArraySegment<byte> receiveBuffer = new ArraySegment<byte>(receiveInternalBuffer, Offset, DatagramSize);
+
             Random rnd = new Random(0);
 
             IPEndPoint remoteEp = new IPEndPoint(ipv4 ? IPAddress.Any : IPAddress.IPv6Any, 0);