init: inital commit

Program.cs

@@ -0,0 +1,56 @@
+using System.Text.Json.Serialization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.SignalR;
+
+WebApplicationBuilder builder = WebApplication.CreateSlimBuilder(args);
+
+builder.Services.AddSignalR();
+
+builder.Services.ConfigureHttpJsonOptions(options =>
+	options.SerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default)
+);
+builder.Services.Configure<JsonHubProtocolOptions>(options =>
+	options.PayloadSerializerOptions.TypeInfoResolverChain.Insert(0, AppJsonSerializerContext.Default)
+);
+
+builder.Services.AddCors(options =>
+{
+	options.AddDefaultPolicy(policy =>
+		policy
+			.SetIsOriginAllowed(_ => true)
+			.WithMethods(["POST"])
+			.WithHeaders(["x-requested-with", "x-signalr-user-agent"])
+			.AllowCredentials());
+});
+
+WebApplication app = builder.Build();
+
+app.UseCors();
+
+app.MapHub<WsHub>("/ws", options =>
+{
+	options.ApplicationMaxBufferSize = 1;       // 1B, virtually disabling ability for clients to send data
+});
+
+app.MapPost("/send",
+	static async (
+		[FromServices] IHubContext<WsHub> hubContext, [FromServices] ILogger<Program> logger,
+		[FromQuery] string id, [FromBody] string data
+	) =>
+	{
+		if (string.IsNullOrWhiteSpace(data) || data.Length > 66_560)
+			return Results.BadRequest();
+
+		logger.LogDebug("Received payload for connection '{id}' (package length: {len})", id, data.Length);
+		await hubContext.Clients.Client(id).SendAsync("ReceiveData", data);
+
+		return Results.Ok();
+	}
+);
+
+app.Run();
+
+class WsHub : Hub { }
+
+[JsonSerializable(typeof(string))]
+internal partial class AppJsonSerializerContext : JsonSerializerContext { }