1 files changed, 120 insertions, 0 deletions
diff --git a/src/Jellyfin.Networking/HappyEyeballs/HttpClientExtension.cs b/src/Jellyfin.Networking/HappyEyeballs/HttpClientExtension.cs
new file mode 100644
index 000000000..d59e4e5e3
--- /dev/null
+++ b/src/Jellyfin.Networking/HappyEyeballs/HttpClientExtension.cs
@@ -0,0 +1,120 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) .NET Foundation and Contributors
+
+All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+using System.IO;
+using System.Net.Http;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Jellyfin.Networking.HappyEyeballs
+{
+    /// <summary>
+    /// Defines the <see cref="HttpClientExtension"/> class.
+    ///
+    /// Implementation taken from https://github.com/ppy/osu-framework/pull/4191 .
+    /// </summary>
+    public static class HttpClientExtension
+    {
+        /// <summary>
+        /// Gets or sets a value indicating whether the client should use IPv6.
+        /// </summary>
+        public static bool UseIPv6 { get; set; } = true;
+
+        /// <summary>
+        /// Implements the httpclient callback method.
+        /// </summary>
+        /// <param name="context">The <see cref="SocketsHttpConnectionContext"/> instance.</param>
+        /// <param name="cancellationToken">The <see cref="CancellationToken"/> instance.</param>
+        /// <returns>The http steam.</returns>
+        public static async ValueTask<Stream> OnConnect(SocketsHttpConnectionContext context, CancellationToken cancellationToken)
+        {
+            if (!UseIPv6)
+            {
+                return await AttemptConnection(AddressFamily.InterNetwork, context, cancellationToken).ConfigureAwait(false);
+            }
+
+            using var cancelIPv6 = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            var tryConnectAsyncIPv6 = AttemptConnection(AddressFamily.InterNetworkV6, context, cancelIPv6.Token);
+
+            // GetAwaiter().GetResult() is used instead of .Result as this results in improved exception handling.
+            // The tasks have already been completed.
+            // See https://github.com/dotnet/corefx/pull/29792/files#r189415885 for more details.
+            if (await Task.WhenAny(tryConnectAsyncIPv6, Task.Delay(200, cancelIPv6.Token)).ConfigureAwait(false) == tryConnectAsyncIPv6 && tryConnectAsyncIPv6.IsCompletedSuccessfully)
+            {
+                await cancelIPv6.CancelAsync().ConfigureAwait(false);
+                return tryConnectAsyncIPv6.GetAwaiter().GetResult();
+            }
+
+            using var cancelIPv4 = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+            var tryConnectAsyncIPv4 = AttemptConnection(AddressFamily.InterNetwork, context, cancelIPv4.Token);
+
+            if (await Task.WhenAny(tryConnectAsyncIPv6, tryConnectAsyncIPv4).ConfigureAwait(false) == tryConnectAsyncIPv6)
+            {
+                if (tryConnectAsyncIPv6.IsCompletedSuccessfully)
+                {
+                    await cancelIPv4.CancelAsync().ConfigureAwait(false);
+                    return tryConnectAsyncIPv6.GetAwaiter().GetResult();
+                }
+
+                return tryConnectAsyncIPv4.GetAwaiter().GetResult();
+            }
+            else
+            {
+                if (tryConnectAsyncIPv4.IsCompletedSuccessfully)
+                {
+                    await cancelIPv6.CancelAsync().ConfigureAwait(false);
+                    return tryConnectAsyncIPv4.GetAwaiter().GetResult();
+                }
+
+                return tryConnectAsyncIPv6.GetAwaiter().GetResult();
+            }
+        }
+
+        private static async Task<Stream> AttemptConnection(AddressFamily addressFamily, SocketsHttpConnectionContext context, CancellationToken cancellationToken)
+        {
+            // The following socket constructor will create a dual-mode socket on systems where IPV6 is available.
+            var socket = new Socket(addressFamily, SocketType.Stream, ProtocolType.Tcp)
+            {
+                // Turn off Nagle's algorithm since it degrades performance in most HttpClient scenarios.
+                NoDelay = true
+            };
+
+            try
+            {
+                await socket.ConnectAsync(context.DnsEndPoint, cancellationToken).ConfigureAwait(false);
+                // The stream should take the ownership of the underlying socket,
+                // closing it when it's disposed.
+                return new NetworkStream(socket, ownsSocket: true);
+            }
+            catch
+            {
+                socket.Dispose();
+                throw;
+            }
+        }
+    }
+}