Fix HTTP/3 ALPN (#56215)

* Fix HTTP/3 ALPN

* Add tests

src/libraries/Common/tests/System/Net/Http/Http3LoopbackServer.cs

@@ -34,9 +34,7 @@ public Http3LoopbackServer(QuicImplementationProvider quicImplementationProvider
                     EnabledSslProtocols = options.SslProtocols,
                     ApplicationProtocols = new List<SslApplicationProtocol>
                     {
-                        new SslApplicationProtocol("h3-31"),
-                        new SslApplicationProtocol("h3-30"),
-                        new SslApplicationProtocol("h3-29")
+                        new SslApplicationProtocol(options.Alpn)
                     },
                     ServerCertificate = _cert,
                     ClientCertificateRequired = false
@@ -122,13 +120,17 @@ private static Http3Options CreateOptions(GenericLoopbackOptions options)
     }
     public class Http3Options : GenericLoopbackOptions
     {
-        public int MaxUnidirectionalStreams {get; set; }
+        public int MaxUnidirectionalStreams { get; set; }
+
+        public int MaxBidirectionalStreams { get; set; }
+
+        public string Alpn { get; set; }
 
-        public int MaxBidirectionalStreams {get; set; }
         public Http3Options()
         {
             MaxUnidirectionalStreams = 100;
             MaxBidirectionalStreams = 100;
+            Alpn = "h3";
         }
     }
 }

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3Connection.cs

@@ -21,9 +21,7 @@ namespace System.Net.Http
     internal sealed class Http3Connection : HttpConnectionBase
     {
         // TODO: once HTTP/3 is standardized, create APIs for this.
-        public static readonly SslApplicationProtocol Http3ApplicationProtocol29 = new SslApplicationProtocol("h3-29");
-        public static readonly SslApplicationProtocol Http3ApplicationProtocol30 = new SslApplicationProtocol("h3-30");
-        public static readonly SslApplicationProtocol Http3ApplicationProtocol31 = new SslApplicationProtocol("h3-31");
+        public static readonly SslApplicationProtocol Http3ApplicationProtocol = new SslApplicationProtocol("h3");
 
         private readonly HttpConnectionPool _pool;
         private readonly HttpAuthority? _origin;

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

@@ -304,7 +304,7 @@ private static List<SslApplicationProtocol> CreateHttp3ApplicationProtocols()
             if (IsHttp3Supported())
             {
                 // TODO: Once the HTTP/3 versions are part of SslApplicationProtocol, see https://github.com/dotnet/runtime/issues/1293, move this back to field initialization.
-                return new List<SslApplicationProtocol>() { Http3Connection.Http3ApplicationProtocol31, Http3Connection.Http3ApplicationProtocol30, Http3Connection.Http3ApplicationProtocol29 };
+                return new List<SslApplicationProtocol>() { Http3Connection.Http3ApplicationProtocol };
             }
 
             return null!;

src/libraries/System.Net.Http/tests/FunctionalTests/HttpClientHandlerTest.Http3.cs

@@ -10,6 +10,7 @@
 using System.Net.Quic;
 using System.Net.Security;
 using System.Net.Test.Common;
+using System.Reflection;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -633,6 +634,128 @@ private static async Task SendDataForever(Http3LoopbackStream stream)
             }
         }
 
+        [ConditionalFact(nameof(IsMsQuicSupported))]
+        public async Task Alpn_H3_Success()
+        {
+            // Mock doesn't use ALPN.
+            if (UseQuicImplementationProvider == QuicImplementationProviders.Mock)
+            {
+                return;
+            }
+
+            var options = new Http3Options() { Alpn = "h3" };
+            using Http3LoopbackServer server = CreateHttp3LoopbackServer(options);
+
+            using var clientDone = new SemaphoreSlim(0);
+            using var serverDone = new SemaphoreSlim(0);
+
+            Task serverTask = Task.Run(async () =>
+            {
+                using Http3LoopbackConnection connection = (Http3LoopbackConnection)await server.EstablishGenericConnectionAsync();
+
+                SslApplicationProtocol negotiatedAlpn = ExtractMsQuicNegotiatedAlpn(connection);
+                Assert.Equal(new SslApplicationProtocol("h3"), negotiatedAlpn);
+
+                using Http3LoopbackStream stream = await connection.AcceptRequestStreamAsync();
+                await stream.HandleRequestAsync();
+
+                serverDone.Release();
+                await clientDone.WaitAsync();
+            });
+
+            Task clientTask = Task.Run(async () =>
+            {
+                using HttpClient client = CreateHttpClient();
+
+                using HttpRequestMessage request = new()
+                    {
+                        Method = HttpMethod.Get,
+                        RequestUri = server.Address,
+                        Version = HttpVersion30,
+                        VersionPolicy = HttpVersionPolicy.RequestVersionExact
+                    };
+                HttpResponseMessage response = await client.SendAsync(request).WaitAsync(TimeSpan.FromSeconds(10));
+
+                response.EnsureSuccessStatusCode();
+                Assert.Equal(HttpVersion.Version30, response.Version);
+
+                clientDone.Release();
+                await serverDone.WaitAsync();
+            });
+
+            await new[] { clientTask, serverTask }.WhenAllOrAnyFailed(200_000);
+        }
+
+        [ConditionalFact(nameof(IsMsQuicSupported))]
+        public async Task Alpn_NonH3_NegotiationFailure()
+        {
+            // Mock doesn't use ALPN.
+            if (UseQuicImplementationProvider == QuicImplementationProviders.Mock)
+            {
+                return;
+            }
+
+            var options = new Http3Options() { Alpn = "h3-29" }; // anything other than "h3"
+            using Http3LoopbackServer server = CreateHttp3LoopbackServer(options);
+
+            using var clientDone = new SemaphoreSlim(0);
+
+            Task serverTask = Task.Run(async () =>
+            {
+                // ALPN handshake handled by transport, app level will not get any notification
+                await clientDone.WaitAsync();
+            });
+
+            Task clientTask = Task.Run(async () =>
+            {
+                using HttpClient client = CreateHttpClient();
+
+                using HttpRequestMessage request = new()
+                    {
+                        Method = HttpMethod.Get,
+                        RequestUri = server.Address,
+                        Version = HttpVersion30,
+                        VersionPolicy = HttpVersionPolicy.RequestVersionExact
+                    };
+
+                HttpRequestException ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request).WaitAsync(TimeSpan.FromSeconds(10)));
+                Assert.Contains("ALPN_NEG_FAILURE", ex.Message);
+
+                clientDone.Release();
+            });
+
+            await new[] { clientTask, serverTask }.WhenAllOrAnyFailed(200_000);
+        }
+
+        private SslApplicationProtocol ExtractMsQuicNegotiatedAlpn(Http3LoopbackConnection loopbackConnection)
+        {
+            // TODO: rewrite after object structure change
+            // current structure:
+            // Http3LoopbackConnection -> private QuicConnection _connection
+            // QuicConnection -> private QuicConnectionProvider _provider (= MsQuicConnection)
+            // MsQuicConnection -> private SslApplicationProtocol _negotiatedAlpnProtocol
+
+            FieldInfo quicConnectionField = loopbackConnection.GetType().GetField("_connection", BindingFlags.Instance | BindingFlags.NonPublic);
+            Assert.NotNull(quicConnectionField);
+            object quicConnection = quicConnectionField.GetValue(loopbackConnection);
+            Assert.NotNull(quicConnection);
+            Assert.Equal("QuicConnection", quicConnection.GetType().Name);
+
+            FieldInfo msQuicConnectionField = quicConnection.GetType().GetField("_provider", BindingFlags.Instance | BindingFlags.NonPublic);
+            Assert.NotNull(msQuicConnectionField);
+            object msQuicConnection = msQuicConnectionField.GetValue(quicConnection);
+            Assert.NotNull(msQuicConnection);
+            Assert.Equal("MsQuicConnection", msQuicConnection.GetType().Name);
+
+            FieldInfo alpnField = msQuicConnection.GetType().GetField("_negotiatedAlpnProtocol", BindingFlags.Instance | BindingFlags.NonPublic);
+            Assert.NotNull(alpnField);
+            object alpn = alpnField.GetValue(msQuicConnection);
+            Assert.NotNull(alpn);
+            Assert.IsType<SslApplicationProtocol>(alpn);
+
+            return (SslApplicationProtocol)alpn;
+        }
+
         /// <summary>
         /// These are public interop test servers for various QUIC and HTTP/3 implementations,
         /// taken from https://github.com/quicwg/base-drafts/wiki/Implementations

src/libraries/System.Net.Http/tests/StressTests/HttpStress/StressServer.cs

@@ -127,7 +127,7 @@ void ConfigureListenOptions(ListenOptions listenOptions)
                 {
                     host = host.UseQuic(options =>
                     {
-                        options.Alpn = "h3-29";
+                        options.Alpn = "h3";
                         options.IdleTimeout = TimeSpan.FromMinutes(1);
                     });
                 }