async Task <MqttConnectPacket> ReceiveConnectPacket(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
{
try
{
using (var timeoutToken = new CancellationTokenSource(_options.DefaultCommunicationTimeout))
using (var effectiveCancellationToken = CancellationTokenSource.CreateLinkedTokenSource(timeoutToken.Token, cancellationToken))
{
var firstPacket = await channelAdapter.ReceivePacketAsync(effectiveCancellationToken.Token).ConfigureAwait(false);
if (firstPacket is MqttConnectPacket connectPacket)
{
return(connectPacket);
}
}
}
catch (OperationCanceledException)
{
_logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
}
catch (MqttCommunicationTimedOutException)
{
_logger.Warning("Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
}
_logger.Warning("Client '{0}': First received packet was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.Endpoint);
return(null);
}
private async Task ReceivePacketsAsync(IMqttChannelAdapter adapter, CancellationToken cancellationToken)
{
try
{
while (!cancellationToken.IsCancellationRequested)
{
var packet = await adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
_lastPacketReceivedTracker.Restart();
if (!(packet is MqttPingReqPacket))
{
_lastNonKeepAlivePacketReceivedTracker.Restart();
}
await ProcessReceivedPacketAsync(adapter, packet, cancellationToken).ConfigureAwait(false);
}
}
catch (OperationCanceledException)
{
}
catch (MqttCommunicationException exception)
{
_logger.Warning <MqttClientSession>(exception, "Client '{0}': Communication exception while processing client packets.", ClientId);
await StopAsync().ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error <MqttClientSession>(exception, "Client '{0}': Unhandled exception while processing client packets.", ClientId);
await StopAsync().ConfigureAwait(false);
}
}
public async Task HandleClientConnectionAsync(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
{
try
{
MqttConnectPacket connectPacket;
try
{
using (var timeoutToken = new CancellationTokenSource(_options.DefaultCommunicationTimeout))
{
var firstPacket = await channelAdapter.ReceivePacketAsync(timeoutToken.Token).ConfigureAwait(false);
connectPacket = firstPacket as MqttConnectPacket;
if (connectPacket == null)
{
_logger.Warning(null,
"Client '{0}': First received packet was no 'CONNECT' packet [MQTT-3.1.0-1].",
channelAdapter.Endpoint);
return;
}
}
}
catch (OperationCanceledException)
{
_logger.Warning(null, "Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
return;
}
catch (MqttCommunicationTimedOutException)
{
_logger.Warning(null, "Client '{0}': Connected but did not sent a CONNECT packet.", channelAdapter.Endpoint);
return;
}
var connectionValidatorContext = await ValidateConnectionAsync(connectPacket, channelAdapter).ConfigureAwait(false);
if (connectionValidatorContext.ReasonCode != MqttConnectReasonCode.Success)
{
// Send failure response here without preparing a session. The result for a successful connect
// will be sent from the session itself.
var connAckPacket = channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnAckPacket(connectionValidatorContext);
await channelAdapter.SendPacketAsync(connAckPacket, cancellationToken).ConfigureAwait(false);
return;
}
var connection = await CreateClientConnectionAsync(connectPacket, connectionValidatorContext, channelAdapter).ConfigureAwait(false);
await _eventDispatcher.SafeNotifyClientConnectedAsync(connectPacket.ClientId).ConfigureAwait(false);
await connection.RunAsync().ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
}
async Task TryReceivePacketsAsync(CancellationToken cancellationToken)
{
try
{
_logger.Verbose("Start receiving packets.");
while (!cancellationToken.IsCancellationRequested)
{
var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (packet == null)
{
if (!DisconnectIsPending())
{
await DisconnectInternalAsync(_packetReceiverTask, null, null).ConfigureAwait(false);
}
return;
}
await TryProcessReceivedPacketAsync(packet, cancellationToken).ConfigureAwait(false);
}
}
catch (Exception exception)
{
if (_cleanDisconnectInitiated)
{
return;
}
if (exception is OperationCanceledException)
{
}
else if (exception is MqttCommunicationException)
{
_logger.Warning(exception, "Communication error while receiving packets.");
}
else
{
_logger.Error(exception, "Error while receiving packets.");
}
_packetDispatcher.Dispatch(exception);
if (!DisconnectIsPending())
{
await DisconnectInternalAsync(_packetReceiverTask, exception, null).ConfigureAwait(false);
}
}
finally
{
_logger.Verbose("Stopped receiving packets.");
}
}
private async Task OnClientConnectedAsync(IMqttChannelAdapter adapter)
{
while (true)
{
var packet = await adapter.ReceivePacketAsync(Timeout.InfiniteTimeSpan, default);
switch (packet)
{
case MqttConnectPacket connectPacket:
await adapter.SendPacketAsync(new MqttConnAckPacket
{
ReturnCode = MqttConnectReturnCode.ConnectionAccepted,
ReasonCode = MqttConnectReasonCode.Success,
IsSessionPresent = false
}, Timeout.InfiniteTimeSpan,
default);
break;
case MqttDisconnectPacket disconnectPacket:
break;
case MqttAuthPacket mqttAuthPacket:
break;
case MqttConnAckPacket connAckPacket:
break;
case MqttPublishPacket mqttPublishPacket:
break;
case MqttSubscribePacket mqttSubscribePacket:
var ack = new MqttSubAckPacket
{
PacketIdentifier = mqttSubscribePacket.PacketIdentifier,
ReturnCodes = new List <MqttSubscribeReturnCode> {
MqttSubscribeReturnCode.SuccessMaximumQoS0
}
};
ack.ReasonCodes.Add(MqttSubscribeReasonCode.GrantedQoS0);
await adapter.SendPacketAsync(ack, Timeout.InfiniteTimeSpan, default);
break;
default:
break;
}
}
}
private async Task ReceivePacketsAsync(CancellationToken cancellationToken)
{
_logger.Info <MqttClient>("Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
_isReceivingPackets = true;
var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
StartProcessReceivedPacket(packet, cancellationToken);
}
}
catch (OperationCanceledException)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
await DisconnectInternalAsync().ConfigureAwait(false);
}
catch (MqttCommunicationException exception)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
_logger.Warning <MqttClient>(exception, "MQTT communication exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error <MqttClient>(exception, "Unhandled exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
finally
{
_logger.Info <MqttClient>("Stopped receiving packets.");
}
}
private async Task ReceivePacketsAsync(CancellationToken cancellationToken)
{
try
{
_logger.Verbose("Start receiving packets.");
while (!cancellationToken.IsCancellationRequested)
{
var packet = await _adapter.ReceivePacketAsync(Options.CommunicationTimeout, cancellationToken)
.ConfigureAwait(false);
if (packet != null && !cancellationToken.IsCancellationRequested)
{
await ProcessReceivedPacketAsync(packet, cancellationToken).ConfigureAwait(false);
}
}
}
catch (Exception exception)
{
if (_cleanDisconnectInitiated)
{
return;
}
if (exception is OperationCanceledException)
{
}
else if (exception is MqttCommunicationException)
{
_logger.Warning(exception, "MQTT communication exception while receiving packets.");
}
else
{
_logger.Error(exception, "Unhandled exception while receiving packets.");
}
_packetDispatcher.Dispatch(exception);
if (!DisconnectIsPending())
{
await DisconnectInternalAsync(_packetReceiverTask, exception).ConfigureAwait(false);
}
}
finally
{
_logger.Verbose("Stopped receiving packets.");
}
}
public async Task <MqttBasePacket> ReceiveAsync(CancellationToken cancellationToken)
{
if (_adapter == null)
{
throw new InvalidOperationException("Low level MQTT client is not connected.");
}
try
{
return(await _adapter.ReceivePacketAsync(cancellationToken).ConfigureAwait(false));
}
catch (Exception)
{
await SafeDisconnect(cancellationToken).ConfigureAwait(false);
throw;
}
}
private async Task ReceivePacketsAsync()
{
_logger.Verbose <MqttClient>("Start receiving packets.");
try
{
while (!_cancellationTokenSource.Token.IsCancellationRequested)
{
_isReceivingPackets = true;
var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
if (_cancellationTokenSource.Token.IsCancellationRequested)
{
return;
}
StartProcessReceivedPacket(packet);
}
}
catch (Exception exception)
{
if (exception is OperationCanceledException)
{
}
else if (exception is MqttCommunicationException)
{
_logger.Warning <MqttClient>(exception, "MQTT communication exception while receiving packets.");
}
else
{
_logger.Error <MqttClient>(exception, "Unhandled exception while receiving packets.");
}
await DisconnectInternalAsync(_packetReceiverTask, exception).ConfigureAwait(false);
}
finally
{
_logger.Verbose <MqttClient>("Stopped receiving packets.");
}
}
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);
}
}
}
async Task RunInternalAsync(CancellationToken cancellationToken)
{
var disconnectType = MqttClientDisconnectType.NotClean;
try
{
_logger.Info("Client '{0}': Session started.", ClientId);
Session.WillMessage = ConnectPacket.WillMessage;
await SendAsync(_channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnAckPacket(_connectionValidatorContext), cancellationToken).ConfigureAwait(false);
Task.Run(() => SendPendingPacketsAsync(cancellationToken), cancellationToken).Forget(_logger);
Session.IsCleanSession = false;
while (!cancellationToken.IsCancellationRequested)
{
Status = MqttClientConnectionStatus.Running;
var packet = await _channelAdapter.ReceivePacketAsync(cancellationToken).ConfigureAwait(false);
if (packet == null)
{
// The client has closed the connection gracefully.
return;
}
Interlocked.Increment(ref _sentPacketsCount);
LastPacketReceivedTimestamp = DateTime.UtcNow;
if (!(packet is MqttPingReqPacket || packet is MqttPingRespPacket))
{
_lastNonKeepAlivePacketReceivedTimestamp = LastPacketReceivedTimestamp;
}
if (packet is MqttPublishPacket publishPacket)
{
await HandleIncomingPublishPacketAsync(publishPacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPubRelPacket pubRelPacket)
{
await HandleIncomingPubRelPacketAsync(pubRelPacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttSubscribePacket subscribePacket)
{
await HandleIncomingSubscribePacketAsync(subscribePacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttUnsubscribePacket unsubscribePacket)
{
await HandleIncomingUnsubscribePacketAsync(unsubscribePacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPingReqPacket)
{
await SendAsync(MqttPingRespPacket.Instance, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttDisconnectPacket)
{
Session.WillMessage = null;
disconnectType = MqttClientDisconnectType.Clean;
StopInternal();
return;
}
else
{
_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}': Error while receiving client packets.", ClientId);
}
StopInternal();
}
finally
{
if (_disconnectReason == MqttDisconnectReasonCode.SessionTakenOver)
{
disconnectType = MqttClientDisconnectType.Takeover;
}
if (Session.WillMessage != null)
{
_sessionsManager.DispatchApplicationMessage(Session.WillMessage, this);
Session.WillMessage = null;
}
_packetDispatcher.Cancel();
_logger.Info("Client '{0}': Connection stopped.", ClientId);
try
{
await _sessionsManager.CleanUpClient(ClientId, _channelAdapter, disconnectType);
}
catch (Exception e)
{
_logger.Error(e, "Client '{0}': Error while cleaning up", ClientId);
}
}
}
public async Task RunSessionAsync(IMqttChannelAdapter clientAdapter, CancellationToken cancellationToken)
{
var clientId = string.Empty;
MqttClientSession clientSession = null;
try
{
if (!(await clientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false) 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);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
}).ConfigureAwait(false);
return;
}
var result = await GetOrCreateClientSessionAsync(connectPacket).ConfigureAwait(false);
clientSession = result.Session;
await clientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = result.IsExistingSession
}).ConfigureAwait(false);
ClientConnectedCallback?.Invoke(new ConnectedMqttClient
{
ClientId = clientId,
ProtocolVersion = clientAdapter.PacketSerializer.ProtocolVersion
});
await clientSession.RunAsync(connectPacket, clientAdapter).ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error <MqttClientSessionsManager>(exception, exception.Message);
}
finally
{
try
{
await clientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout).ConfigureAwait(false);
}
catch (Exception)
{
// ignored
}
ClientDisconnectedCallback?.Invoke(new ConnectedMqttClient
{
ClientId = clientId,
ProtocolVersion = clientAdapter.PacketSerializer.ProtocolVersion,
PendingApplicationMessages = clientSession?.PendingMessagesQueue.Count ?? 0
});
}
}
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);
}
async Task RunInternalAsync()
{
var disconnectType = MqttClientDisconnectType.NotClean;
try
{
_logger.Info("Client '{0}': Session started.", ClientId);
_channelAdapter.ReadingPacketStartedCallback = OnAdapterReadingPacketStarted;
_channelAdapter.ReadingPacketCompletedCallback = OnAdapterReadingPacketCompleted;
Session.WillMessage = ConnectPacket.WillMessage;
Task.Run(() => SendPendingPacketsAsync(_cancellationToken.Token), _cancellationToken.Token).Forget(_logger);
// TODO: Change to single thread in SessionManager. Or use SessionManager and stats from KeepAliveMonitor.
_keepAliveMonitor.Start(ConnectPacket.KeepAlivePeriod, _cancellationToken.Token);
await SendAsync(_channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnAckPacket(_connectionValidatorContext)).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}': Error while receiving client packets.", ClientId);
}
StopInternal();
}
finally
{
if (_isTakeover)
{
disconnectType = MqttClientDisconnectType.Takeover;
}
if (Session.WillMessage != null)
{
_sessionsManager.DispatchApplicationMessage(Session.WillMessage, this);
Session.WillMessage = null;
}
_packetDispatcher.Reset();
_channelAdapter.ReadingPacketStartedCallback = null;
_channelAdapter.ReadingPacketCompletedCallback = null;
_packageReceiverTask = null;
if (_isTakeover)
{
try
{
// Don't use SendAsync here _cancellationToken is already cancelled.
await _channelAdapter.SendPacketAsync(new MqttDisconnectPacket
{
ReasonCode = MqttDisconnectReasonCode.SessionTakenOver
}, TimeSpan.Zero, CancellationToken.None).ConfigureAwait(false);
}
catch (Exception exception)
{
_logger.Error(exception, "Client '{0}': Error while sending DISCONNECT packet after takeover.", ClientId);
}
}
_logger.Info("Client '{0}': Connection stopped.", ClientId);
try
{
await _sessionsManager.CleanUpClient(ClientId, _channelAdapter, disconnectType);
}
catch (Exception e)
{
_logger.Error(e, "Client '{0}': Error while cleaning up", ClientId);
}
}
}
private async Task HandleClientAsync(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
{
var disconnectType = MqttClientDisconnectType.NotClean;
string clientId = null;
try
{
var firstPacket = await channelAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
if (!(firstPacket is MqttConnectPacket connectPacket))
{
_logger.Warning(null, "The first packet from client '{0}' was no 'CONNECT' packet [MQTT-3.1.0-1].", channelAdapter.Endpoint);
return;
}
clientId = connectPacket.ClientId;
var validatorContext = await ValidateConnectionAsync(connectPacket, channelAdapter).ConfigureAwait(false);
if (validatorContext.ReasonCode != MqttConnectReasonCode.Success)
{
// Send failure response here without preparing a session. The result for a successful connect
// will be sent from the session itself.
var connAckPacket = channelAdapter.PacketFormatterAdapter.DataConverter.CreateConnAckPacket(validatorContext);
await channelAdapter.SendPacketAsync(connAckPacket, _options.DefaultCommunicationTimeout, cancellationToken).ConfigureAwait(false);
return;
}
var connection = await CreateConnectionAsync(channelAdapter, connectPacket).ConfigureAwait(false);
await _eventDispatcher.HandleClientConnectedAsync(clientId).ConfigureAwait(false);
disconnectType = await connection.RunAsync().ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
finally
{
if (clientId != null)
{
_connections.TryRemove(clientId, out _);
if (!_options.EnablePersistentSessions)
{
await DeleteSessionAsync(clientId).ConfigureAwait(false);
}
}
await TryCleanupChannelAsync(channelAdapter).ConfigureAwait(false);
if (clientId != null)
{
await _eventDispatcher.TryHandleClientDisconnectedAsync(clientId, disconnectType).ConfigureAwait(false);
}
}
}
async Task ReceivePackagesLoop(CancellationToken cancellationToken)
{
try
{
// We do not listen for the cancellation token here because the internal buffer might still
// contain data to be read even if the TCP connection was already dropped. So we rely on an
// own exception in the reading loop!
while (!cancellationToken.IsCancellationRequested)
{
var packet = await _channelAdapter.ReceivePacketAsync(cancellationToken).ConfigureAwait(false);
if (packet == null)
{
// The client has closed the connection gracefully.
return;
}
Statistics.HandleReceivedPacket(packet);
if (packet is MqttPublishPacket publishPacket)
{
await HandleIncomingPublishPacket(publishPacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPubRelPacket pubRelPacket)
{
await HandleIncomingPubRelPacket(pubRelPacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttSubscribePacket subscribePacket)
{
await HandleIncomingSubscribePacket(subscribePacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttUnsubscribePacket unsubscribePacket)
{
await HandleIncomingUnsubscribePacket(unsubscribePacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPingReqPacket)
{
// See: The Server MUST send a PINGRESP packet in response to a PINGREQ packet [MQTT-3.12.4-1].
await SendPacketAsync(MqttPingRespPacket.Instance, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPingRespPacket)
{
throw new MqttProtocolViolationException("A PINGRESP Packet is sent by the Server to the Client in response to a PINGREQ Packet only.");
}
else if (packet is MqttDisconnectPacket)
{
IsCleanDisconnect = true;
return;
}
else
{
if (!_packetDispatcher.TryDispatch(packet))
{
throw new MqttProtocolViolationException($"Received packet '{packet}' at an unexpected time.");
}
}
}
}
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}': Error while receiving client packets.", ClientId);
}
}
}
private async Task RunInternalAsync(MqttConnectPacket connectPacket, IMqttChannelAdapter adapter)
{
if (connectPacket == null)
{
throw new ArgumentNullException(nameof(connectPacket));
}
if (adapter == null)
{
throw new ArgumentNullException(nameof(adapter));
}
try
{
if (_cancellationTokenSource != null)
{
Stop(MqttClientDisconnectType.Clean, true);
}
adapter.ReadingPacketStarted += OnAdapterReadingPacketStarted;
adapter.ReadingPacketCompleted += OnAdapterReadingPacketCompleted;
_cancellationTokenSource = new CancellationTokenSource();
//workaround for https://github.com/dotnet/corefx/issues/24430
#pragma warning disable 4014
_cleanupHandle = _cancellationTokenSource.Token.Register(async() =>
{
await TryDisconnectAdapterAsync(adapter).ConfigureAwait(false);
TryDisposeAdapter(adapter);
});
#pragma warning restore 4014
//end workaround
_wasCleanDisconnect = false;
_willMessage = connectPacket.WillMessage;
_pendingPacketsQueue.Start(adapter, _cancellationTokenSource.Token);
_keepAliveMonitor.Start(connectPacket.KeepAlivePeriod, _cancellationTokenSource.Token);
_adapterEndpoint = adapter.Endpoint;
_adapterProtocolVersion = adapter.PacketSerializer.ProtocolVersion;
while (!_cancellationTokenSource.IsCancellationRequested)
{
var packet = await adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
if (packet != null)
{
_keepAliveMonitor.PacketReceived(packet);
ProcessReceivedPacket(adapter, packet, _cancellationTokenSource.Token);
}
}
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
if (exception is MqttCommunicationException)
{
if (exception is MqttCommunicationClosedGracefullyException)
{
_logger.Verbose("Client '{0}': Connection closed gracefully.", ClientId);
}
else
{
_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);
}
Stop(MqttClientDisconnectType.NotClean, true);
}
finally
{
_adapterEndpoint = null;
_adapterProtocolVersion = null;
// Uncomment as soon as the workaround above is no longer needed.
//await TryDisconnectAdapterAsync(adapter).ConfigureAwait(false);
//TryDisposeAdapter(adapter);
_cleanupHandle?.Dispose();
_cleanupHandle = null;
_cancellationTokenSource?.Cancel(false);
_cancellationTokenSource?.Dispose();
_cancellationTokenSource = null;
}
}
public async Task <bool> RunAsync(MqttConnectPacket connectPacket, IMqttChannelAdapter adapter)
{
if (connectPacket == null)
{
throw new ArgumentNullException(nameof(connectPacket));
}
if (adapter == null)
{
throw new ArgumentNullException(nameof(adapter));
}
try
{
_adapter = adapter;
adapter.ReadingPacketStarted += OnAdapterReadingPacketStarted;
adapter.ReadingPacketCompleted += OnAdapterReadingPacketCompleted;
_cancellationTokenSource = new CancellationTokenSource();
_wasCleanDisconnect = false;
_willMessage = connectPacket.WillMessage;
_pendingPacketsQueue.Start(adapter, _cancellationTokenSource.Token);
_keepAliveMonitor.Start(connectPacket.KeepAlivePeriod, _cancellationTokenSource.Token);
while (!_cancellationTokenSource.IsCancellationRequested)
{
var packet = await adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
if (packet != null)
{
_keepAliveMonitor.PacketReceived(packet);
ProcessReceivedPacket(adapter, packet, _cancellationTokenSource.Token);
}
}
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
if (exception is MqttCommunicationException)
{
if (exception is MqttCommunicationClosedGracefullyException)
{
_logger.Verbose("Client '{0}': Connection closed gracefully.", ClientId);
}
else
{
_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);
}
Stop(MqttClientDisconnectType.NotClean);
}
finally
{
if (_adapter != null)
{
_adapter.ReadingPacketStarted -= OnAdapterReadingPacketStarted;
_adapter.ReadingPacketCompleted -= OnAdapterReadingPacketCompleted;
}
_adapter = null;
_cancellationTokenSource?.Dispose();
_cancellationTokenSource = null;
}
return(_wasCleanDisconnect);
}