public async Task StartAsync(IMqttServerOptions options)
{
Options = options ?? throw new ArgumentNullException(nameof(options));
if (_cancellationTokenSource != null)
{
throw new InvalidOperationException("The server is already started.");
}
_cancellationTokenSource = new CancellationTokenSource();
_retainedMessagesManager = new MqttRetainedMessagesManager(Options, _logger);
await _retainedMessagesManager.LoadMessagesAsync().ConfigureAwait(false);
_clientSessionsManager = new MqttClientSessionsManager(Options, _retainedMessagesManager, _cancellationTokenSource.Token, _eventDispatcher, _logger);
_clientSessionsManager.Start();
foreach (var adapter in _adapters)
{
adapter.ClientAccepted += OnClientAccepted;
await adapter.StartAsync(Options).ConfigureAwait(false);
}
_logger.Info("Started.");
Started?.Invoke(this, EventArgs.Empty);
}
public async Task <MqttClientConnectResult> ConnectAsync(IMqttClientOptions options)
{
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
if (options.ChannelOptions == null)
{
throw new ArgumentException("ChannelOptions are not set.");
}
ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");
try
{
Options = options;
_packetIdentifierProvider.Reset();
_packetDispatcher.Reset();
_cancellationTokenSource = new CancellationTokenSource();
_disconnectGate = 0;
_adapter = _adapterFactory.CreateClientAdapter(options, _logger);
_logger.Verbose($"Trying to connect with server ({Options.ChannelOptions}).");
await _adapter.ConnectAsync(Options.CommunicationTimeout, _cancellationTokenSource.Token).ConfigureAwait(false);
_logger.Verbose("Connection with server established.");
StartReceivingPackets(_cancellationTokenSource.Token);
var connectResponse = await AuthenticateAsync(options.WillMessage, _cancellationTokenSource.Token).ConfigureAwait(false);
_logger.Verbose("MQTT connection with server established.");
_sendTracker.Restart();
if (Options.KeepAlivePeriod != TimeSpan.Zero)
{
StartSendingKeepAliveMessages(_cancellationTokenSource.Token);
}
IsConnected = true;
Connected?.Invoke(this, new MqttClientConnectedEventArgs(connectResponse.IsSessionPresent));
_logger.Info("Connected.");
return(new MqttClientConnectResult(connectResponse.IsSessionPresent));
}
catch (Exception exception)
{
_logger.Error(exception, "Error while connecting with server.");
if (!DisconnectIsPending())
{
await DisconnectInternalAsync(null, exception).ConfigureAwait(false);
}
throw;
}
}
private void Stop(MqttClientDisconnectType type, bool isInsideSession)
{
try
{
var cts = _cancellationTokenSource;
if (cts == null || cts.IsCancellationRequested)
{
return;
}
_cancellationTokenSource?.Cancel(false);
_wasCleanDisconnect = type == MqttClientDisconnectType.Clean;
if (_willMessage != null && !_wasCleanDisconnect)
{
_sessionsManager.EnqueueApplicationMessage(this, _willMessage.ToPublishPacket());
}
_willMessage = null;
if (!isInsideSession)
{
_workerTask?.GetAwaiter().GetResult();
}
}
finally
{
_logger.Info("Client '{0}': Disconnected (clean={1}).", ClientId, _wasCleanDisconnect);
_eventDispatcher.OnClientDisconnected(ClientId, _wasCleanDisconnect);
}
}
public bool Start(bool treatErrorsAsWarning, CancellationToken cancellationToken)
{
try
{
var boundIp = _options.BoundInterNetworkAddress;
if (_addressFamily == AddressFamily.InterNetworkV6)
{
boundIp = _options.BoundInterNetworkV6Address;
}
_localEndPoint = new IPEndPoint(boundIp, _options.Port);
_logger.Info($"Starting TCP listener for {_localEndPoint} TLS={_tlsCertificate != null}.");
_socket = new Socket(_addressFamily, SocketType.Stream, ProtocolType.Tcp);
_socket.Bind(_localEndPoint);
_socket.Listen(_options.ConnectionBacklog);
Task.Run(() => AcceptClientConnectionsAsync(cancellationToken), cancellationToken).Forget(_logger);
return(true);
}
catch (Exception exception)
{
if (!treatErrorsAsWarning)
{
throw;
}
_logger.Warning(exception, "Error while creating listener socket for local end point '{0}'.", _localEndPoint);
return(false);
}
}
public void Stop(MqttClientDisconnectType type)
{
try
{
var cts = _cancellationTokenSource;
if (cts == null || cts.IsCancellationRequested)
{
return;
}
_wasCleanDisconnect = type == MqttClientDisconnectType.Clean;
_cancellationTokenSource?.Cancel(false);
if (_willMessage != null && !_wasCleanDisconnect)
{
_sessionsManager.EnqueueApplicationMessage(this, _willMessage.ToPublishPacket());
}
_willMessage = null;
}
finally
{
_logger.Info("Client '{0}': Session stopped.", ClientId);
}
}
private async Task HandleMessageInternalAsync(string clientId, MqttApplicationMessage applicationMessage)
{
var saveIsRequired = false;
lock (_messages)
{
if (applicationMessage.Payload?.Length == 0)
{
saveIsRequired = _messages.Remove(applicationMessage.Topic);
_logger.Info("Client '{0}' cleared retained message for topic '{1}'.", clientId, applicationMessage.Topic);
}
else
{
if (!_messages.TryGetValue(applicationMessage.Topic, out var existingMessage))
{
_messages[applicationMessage.Topic] = applicationMessage;
saveIsRequired = true;
}
else
{
if (existingMessage.QualityOfServiceLevel != applicationMessage.QualityOfServiceLevel || !existingMessage.Payload.SequenceEqual(applicationMessage.Payload ?? new byte[0]))
{
_messages[applicationMessage.Topic] = applicationMessage;
saveIsRequired = true;
}
}
_logger.Info("Client '{0}' set retained message for topic '{1}'.", clientId, applicationMessage.Topic);
}
}
if (!saveIsRequired)
{
_logger.Verbose("Skipped saving retained messages because no changes were detected.");
}
if (saveIsRequired && _options.Storage != null)
{
List <MqttApplicationMessage> messages;
lock (_messages)
{
messages = _messages.Values.ToList();
}
await _options.Storage.SaveRetainedMessagesAsync(messages).ConfigureAwait(false);
}
}
public async Task StartAsync(IMqttManagedClientOptions options)
{
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
if (options.ClientOptions == null)
{
throw new ArgumentException("The client options are not set.", nameof(options));
}
if (!options.ClientOptions.CleanSession)
{
throw new NotSupportedException("The managed client does not support existing sessions.");
}
if (_connectionCancellationToken != null)
{
throw new InvalidOperationException("The managed client is already started.");
}
Options = options;
if (Options.Storage != null)
{
_storageManager = new MqttManagedClientStorageManager(Options.Storage);
var messages = await _storageManager.LoadQueuedMessagesAsync().ConfigureAwait(false);
foreach (var message in messages)
{
_messageQueue.Enqueue(message);
}
}
_connectionCancellationToken = new CancellationTokenSource();
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
Task.Run(() => MaintainConnectionAsync(_connectionCancellationToken.Token), _connectionCancellationToken.Token);
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
_logger.Info("Started");
}
public void Start()
{
var boundIp = _options.BoundInterNetworkAddress;
if (_addressFamily == AddressFamily.InterNetworkV6)
{
boundIp = _options.BoundInterNetworkV6Address;
}
_socket = new Socket(_addressFamily, SocketType.Stream, ProtocolType.Tcp);
_socket.Bind(new IPEndPoint(boundIp, _options.Port));
_logger.Info($"Starting TCP listener for {_socket.LocalEndPoint} TLS={_tlsCertificate != null}.");
_socket.Listen(_options.ConnectionBacklog);
Task.Run(AcceptClientConnectionsAsync, _cancellationToken);
}
public bool Start(bool treatErrorsAsWarning, CancellationToken cancellationToken)
{
try
{
var boundIp = _options.BoundInterNetworkAddress;
if (_addressFamily == AddressFamily.InterNetworkV6)
{
boundIp = _options.BoundInterNetworkV6Address;
}
_localEndPoint = new IPEndPoint(boundIp, _options.Port);
_logger.Info($"Starting TCP listener for {_localEndPoint} TLS={_tlsCertificate != null}.");
_socket = new Socket(_addressFamily, SocketType.Stream, ProtocolType.Tcp);
// Usage of socket options is described here: https://docs.microsoft.com/en-us/dotnet/api/system.net.sockets.socket.setsocketoption?view=netcore-2.2
if (_options.ReuseAddress)
{
_socket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
}
if (_options.NoDelay)
{
_socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.NoDelay, true);
}
_socket.Bind(_localEndPoint);
_socket.Listen(_options.ConnectionBacklog);
Task.Run(() => AcceptClientConnectionsAsync(cancellationToken), cancellationToken).Forget(_logger);
return(true);
}
catch (Exception exception)
{
if (!treatErrorsAsWarning)
{
throw;
}
_logger.Warning(exception, "Error while creating listener socket for local end point '{0}'.", _localEndPoint);
return(false);
}
}
private async Task RunSessionAsync(IMqttChannelAdapter clientAdapter, CancellationToken cancellationToken)
{
var clientId = string.Empty;
try
{
var firstPacket = await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
if (firstPacket == null)
{
return;
}
if (!(firstPacket is MqttConnectPacket connectPacket))
{
throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
}
clientId = connectPacket.ClientId;
// Switch to the required protocol version before sending any response.
clientAdapter.PacketSerializer.ProtocolVersion = connectPacket.ProtocolVersion;
var connectReturnCode = ValidateConnection(connectPacket, clientAdapter);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await clientAdapter.SendPacketAsync(
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
},
cancellationToken).ConfigureAwait(false);
return;
}
var result = PrepareClientSession(connectPacket);
await clientAdapter.SendPacketAsync(
new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = result.IsExistingSession
},
cancellationToken).ConfigureAwait(false);
_logger.Info("Client '{0}': Connected.", clientId);
_eventDispatcher.OnClientConnected(clientId);
await result.Session.RunAsync(connectPacket, clientAdapter).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
finally
{
if (!_options.EnablePersistentSessions)
{
DeleteSession(clientId);
}
}
}
private async Task <MqttClientDisconnectType> RunInternalAsync()
{
var disconnectType = MqttClientDisconnectType.NotClean;
try
{
_logger.Info("Client '{0}': Session started.", ClientId);
_channelAdapter.ReadingPacketStartedCallback = OnAdapterReadingPacketStarted;
_channelAdapter.ReadingPacketCompletedCallback = OnAdapterReadingPacketCompleted;
Session.WillMessage = _connectPacket.WillMessage;
#pragma warning disable 4014
Task.Run(() => SendPendingPacketsAsync(_cancellationToken.Token), _cancellationToken.Token);
#pragma warning restore 4014
// TODO: Change to single thread in SessionManager. Or use SessionManager and stats from KeepAliveMonitor.
_keepAliveMonitor.Start(_connectPacket.KeepAlivePeriod, _cancellationToken.Token);
await SendAsync(
new MqttConnAckPacket
{
ReturnCode = MqttConnectReturnCode.ConnectionAccepted,
ReasonCode = MqttConnectReasonCode.Success,
IsSessionPresent = !Session.IsCleanSession
}).ConfigureAwait(false);
Session.IsCleanSession = false;
while (!_cancellationToken.IsCancellationRequested)
{
var packet = await _channelAdapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationToken.Token).ConfigureAwait(false);
if (packet == null)
{
// The client has closed the connection gracefully.
break;
}
Interlocked.Increment(ref _sentPacketsCount);
_lastPacketReceivedTimestamp = DateTime.UtcNow;
if (!(packet is MqttPingReqPacket || packet is MqttPingRespPacket))
{
_lastNonKeepAlivePacketReceivedTimestamp = _lastPacketReceivedTimestamp;
}
_keepAliveMonitor.PacketReceived();
if (packet is MqttPublishPacket publishPacket)
{
await HandleIncomingPublishPacketAsync(publishPacket).ConfigureAwait(false);
continue;
}
if (packet is MqttPubRelPacket pubRelPacket)
{
var pubCompPacket = new MqttPubCompPacket
{
PacketIdentifier = pubRelPacket.PacketIdentifier,
ReasonCode = MqttPubCompReasonCode.Success
};
await SendAsync(pubCompPacket).ConfigureAwait(false);
continue;
}
if (packet is MqttSubscribePacket subscribePacket)
{
await HandleIncomingSubscribePacketAsync(subscribePacket).ConfigureAwait(false);
continue;
}
if (packet is MqttUnsubscribePacket unsubscribePacket)
{
await HandleIncomingUnsubscribePacketAsync(unsubscribePacket).ConfigureAwait(false);
continue;
}
if (packet is MqttPingReqPacket)
{
await SendAsync(new MqttPingRespPacket()).ConfigureAwait(false);
continue;
}
if (packet is MqttDisconnectPacket)
{
Session.WillMessage = null;
disconnectType = MqttClientDisconnectType.Clean;
StopInternal();
break;
}
_packetDispatcher.Dispatch(packet);
}
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
if (exception is MqttCommunicationException)
{
_logger.Warning(exception, "Client '{0}': Communication exception while receiving client packets.", ClientId);
}
else
{
_logger.Error(exception, "Client '{0}': Unhandled exception while receiving client packets.", ClientId);
}
StopInternal();
}
finally
{
if (Session.WillMessage != null)
{
_sessionsManager.DispatchApplicationMessage(Session.WillMessage, this);
Session.WillMessage = null;
}
_packetDispatcher.Reset();
_channelAdapter.ReadingPacketStartedCallback = null;
_channelAdapter.ReadingPacketCompletedCallback = null;
_logger.Info("Client '{0}': Session stopped.", ClientId);
_packageReceiverTask = null;
}
return(disconnectType);
}
public async Task <MqttClientAuthenticateResult> ConnectAsync(IMqttClientOptions options, CancellationToken cancellationToken)
{
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
if (options.ChannelOptions == null)
{
throw new ArgumentException("ChannelOptions are not set.");
}
ThrowIfConnected("It is not allowed to connect with a server after the connection is established.");
ThrowIfDisposed();
MqttClientAuthenticateResult authenticateResult = null;
try
{
Options = options;
_packetIdentifierProvider.Reset();
_packetDispatcher.Reset();
_backgroundCancellationTokenSource = new CancellationTokenSource();
var backgroundCancellationToken = _backgroundCancellationTokenSource.Token;
_disconnectGate = 0;
var adapter = _adapterFactory.CreateClientAdapter(options, _logger);
_adapter = adapter;
using (var combined = CancellationTokenSource.CreateLinkedTokenSource(backgroundCancellationToken, cancellationToken))
{
_logger.Verbose($"Trying to connect with server '{options.ChannelOptions}' (Timeout={options.CommunicationTimeout}).");
await _adapter.ConnectAsync(options.CommunicationTimeout, combined.Token).ConfigureAwait(false);
_logger.Verbose("Connection with server established.");
_packetReceiverTask = Task.Run(() => TryReceivePacketsAsync(backgroundCancellationToken), backgroundCancellationToken);
authenticateResult = await AuthenticateAsync(adapter, options.WillMessage, combined.Token).ConfigureAwait(false);
}
_sendTracker.Restart();
_receiveTracker.Restart();
if (Options.KeepAlivePeriod != TimeSpan.Zero)
{
_keepAlivePacketsSenderTask = Task.Run(() => TrySendKeepAliveMessagesAsync(backgroundCancellationToken), backgroundCancellationToken);
}
IsConnected = true;
_logger.Info("Connected.");
var connectedHandler = ConnectedHandler;
if (connectedHandler != null)
{
await connectedHandler.HandleConnectedAsync(new MqttClientConnectedEventArgs(authenticateResult)).ConfigureAwait(false);
}
return(authenticateResult);
}
catch (Exception exception)
{
_logger.Error(exception, "Error while connecting with server.");
if (!DisconnectIsPending())
{
await DisconnectInternalAsync(null, exception, authenticateResult).ConfigureAwait(false);
}
throw;
}
}