Unix Domain Socket doesn't support on Windows

[reitowo]

Version

20.18.0

Platform

Microsoft Windows NT 10.0.26100.0 x64

Subsystem

No response

What steps will reproduce the bug?

Currently, Windows (at least .NET) supports connect to UnixDomainSocket, or listen to UnixDomainSocket in ASP.NET Core. But node's net module seems not support connect to a Windows local file.

public class UnixDomainSocketsConnectionFactory(EndPoint endPoint) {
   public async ValueTask<Stream> ConnectAsync(SocketsHttpConnectionContext _,
      CancellationToken cancellationToken = default) {
      var socket = new Socket(AddressFamily.Unix, SocketType.Stream, ProtocolType.Unspecified);

      try {
         await socket.ConnectAsync(endPoint, cancellationToken).ConfigureAwait(false);
         return new NetworkStream(socket, true);
      } catch {
         socket.Dispose();
         throw;
      }
   }

   public static GrpcChannel CreateChannel(string socketPath) {
      var udsEndPoint = new UnixDomainSocketEndPoint(socketPath);
      var connectionFactory = new UnixDomainSocketsConnectionFactory(udsEndPoint);
      var socketsHttpHandler = new SocketsHttpHandler {
         ConnectCallback = connectionFactory.ConnectAsync
      };

      return GrpcChannel.ForAddress("http://localhost", new GrpcChannelOptions {
         HttpHandler = socketsHttpHandler
      });
   }
}

   protected void Initialize(string token) {
      var builder = WebApplication.CreateBuilder();
      builder.WebHost.ConfigureKestrel(serverOptions => {
         if (!Directory.Exists(MetaBoxStatic.UnixSocketPath)) {
            Directory.CreateDirectory(MetaBoxStatic.UnixSocketPath);
         }

         var socketPath = Path.Combine(MetaBoxStatic.UnixSocketPath, $"MetaBox-{token}.tmp");
         serverOptions.ListenUnixSocket(socketPath);
         serverOptions.ConfigureEndpointDefaults(listenOptions => { listenOptions.Protocols = HttpProtocols.Http2; });
      });

      ConfigureBuilder(builder);
      builder.Services.PostConfigureAll<HostOptions>(opts => opts.ShutdownTimeout = TimeSpan.FromSeconds(1));

      WebApp = builder.Build();
      ConfigureApp(WebApp);
   }

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior? Why is that the expected behavior?

The net connects to the "Windows" UnixDomainSocket as it could.

What do you see instead?

EACCESS / ENOENT

Additional information

No response

[bnoordhuis]

OP is aware this needs to happen in libuv first, see https://github.com/libuv/libuv/issues/2537#issuecomment-2495828123 and note the unsubstantiated performance claim.

[reitowo]

About performance I'll leave some extra into there.