MQTTnet/Source/MQTTnet.Tests/Server/Connection_Tests.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Net;
using System.Net.Sockets;
using MQTTnet.Implementations;
using MQTTnet.Server;

namespace MQTTnet.Tests.Server;

// ReSharper disable InconsistentNaming
[TestClass]
public sealed class Connection_Tests : BaseTestClass
{
    [TestMethod]
    public async Task Close_Idle_Connection_On_Connect()
    {
        using var testEnvironment = CreateTestEnvironment();
        await testEnvironment.StartServer(new MqttServerOptionsBuilder().WithDefaultCommunicationTimeout(TimeSpan.FromSeconds(1)));

        var client = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
        await client.ConnectAsync(new DnsEndPoint("localhost", testEnvironment.ServerPort), CancellationToken.None);

        // Don't send anything. The server should close the connection.
        await Task.Delay(TimeSpan.FromSeconds(3));

        try
        {
            var receivedBytes = await client.ReceiveAsync(new ArraySegment<byte>(new byte[10]), SocketFlags.Partial);
            if (receivedBytes == 0)
            {
                return;
            }

            Assert.Fail("Receive should throw an exception.");
        }
        catch (SocketException)
        {
        }
    }

    [TestMethod]
    public async Task Send_Garbage()
    {
        using var testEnvironment = CreateTestEnvironment();
        await testEnvironment.StartServer(new MqttServerOptionsBuilder().WithDefaultCommunicationTimeout(TimeSpan.FromSeconds(1)));

        // Send an invalid packet and ensure that the server will close the connection and stay in a waiting state
        // forever. This is security related.
        var client = new CrossPlatformSocket(AddressFamily.InterNetwork, ProtocolType.Tcp);
        await client.ConnectAsync(new DnsEndPoint("localhost", testEnvironment.ServerPort), CancellationToken.None);

        var buffer = "Garbage"u8.ToArray();
        await client.SendAsync(new ArraySegment<byte>(buffer), SocketFlags.None);

        await Task.Delay(TimeSpan.FromSeconds(3));

        try
        {
            var receivedBytes = await client.ReceiveAsync(new ArraySegment<byte>(new byte[10]), SocketFlags.Partial);
            if (receivedBytes == 0)
            {
                return;
            }

            Assert.Fail("Receive should throw an exception.");
        }
        catch (SocketException)
        {
        }
    }
}