private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var mqttPacket = await _adapter.ReceivePacketAsync(TimeSpan.Zero);
MqttTrace.Information(nameof(MqttClient), $"Received <<< {mqttPacket}");
#pragma warning disable CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
Task.Run(() => ProcessReceivedPacketAsync(mqttPacket), cancellationToken);
#pragma warning restore CS4014 // Because this call is not awaited, execution of the current method continues before the call is completed
}
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while receiving packets.");
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
await DisconnectInternalAsync();
}
}
private async Task TrySendPendingPublishPacketAsync(MqttClientPublishPacketContext publishPacketContext)
{
try
{
if (_adapter == null)
{
return;
}
publishPacketContext.PublishPacket.Dup = publishPacketContext.SendTries > 0;
await _adapter.SendPacketAsync(publishPacketContext.PublishPacket, _options.DefaultCommunicationTimeout);
publishPacketContext.IsSent = true;
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClientMessageQueue), exception, "Sending publish packet failed.");
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClientMessageQueue), exception, "Sending publish packet failed.");
}
finally
{
publishPacketContext.SendTries++;
}
}
private Task ProcessReceivedPacketAsync(MqttBasePacket mqttPacket)
{
try
{
if (mqttPacket is MqttPingReqPacket)
{
return(SendAsync(new MqttPingRespPacket()));
}
if (mqttPacket is MqttDisconnectPacket)
{
return(DisconnectAsync());
}
var publishPacket = mqttPacket as MqttPublishPacket;
if (publishPacket != null)
{
return(ProcessReceivedPublishPacket(publishPacket));
}
var pubRelPacket = mqttPacket as MqttPubRelPacket;
if (pubRelPacket != null)
{
return(ProcessReceivedPubRelPacket(pubRelPacket));
}
_packetDispatcher.Dispatch(mqttPacket);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while processing received packet.");
}
return(Task.FromResult(0));
}
private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var mqttPacket = await _adapter.ReceivePacketAsync(TimeSpan.Zero);
MqttTrace.Information(nameof(MqttClient), $"Received <<< {mqttPacket}");
Task.Run(() => ProcessReceivedPacket(mqttPacket), cancellationToken).Forget();
}
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication error while receiving packets.");
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while receiving packets.");
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
await DisconnectInternalAsync();
}
}
private void AcceptDefaultEndpointConnectionsAsync(StreamSocketListener sender, StreamSocketListenerConnectionReceivedEventArgs args)
{
try
{
var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(args.Socket), new MqttV311PacketSerializer());
ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(args.Socket.Information.RemoteAddress.ToString(), clientAdapter));
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServerAdapter), exception, "Error while acceping connection at default endpoint.");
}
}
private void FireApplicationMessageReceivedEvent(MqttPublishPacket publishPacket)
{
try
{
var applicationMessage = publishPacket.ToApplicationMessage();
ApplicationMessageReceived?.Invoke(this, new MqttApplicationMessageReceivedEventArgs(applicationMessage));
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Unhandled exception while handling application message.");
}
}
private async Task AcceptDefaultEndpointConnectionsAsync(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var clientSocket = await Task.Factory.FromAsync(_defaultEndpointSocket.BeginAccept, _defaultEndpointSocket.EndAccept, null);
var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, null), new DefaultMqttV311PacketSerializer());
ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
}
catch (Exception exception) when(!(exception is ObjectDisposedException))
{
MqttTrace.Error(nameof(MqttServerAdapter), exception, "Error while acceping connection at default endpoint.");
}
}
}
public async Task RunAsync(string identifier, MqttApplicationMessage willApplicationMessage, IMqttCommunicationAdapter adapter)
{
if (adapter == null)
{
throw new ArgumentNullException(nameof(adapter));
}
_willApplicationMessage = willApplicationMessage;
try
{
_identifier = identifier;
Adapter = adapter;
_cancellationTokenSource = new CancellationTokenSource();
_messageQueue.Start(adapter);
while (!_cancellationTokenSource.IsCancellationRequested)
{
var packet = await adapter.ReceivePacketAsync(TimeSpan.Zero, _cancellationTokenSource.Token).ConfigureAwait(false);
await HandleIncomingPacketAsync(packet).ConfigureAwait(false);
}
}
catch (MqttCommunicationException)
{
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClientSession), exception, "Client '{0}': Unhandled exception while processing client packets.", _identifier);
}
finally
{
if (willApplicationMessage != null)
{
_publishPacketReceivedCallback(this, _willApplicationMessage.ToPublishPacket());
}
_messageQueue.Stop();
_cancellationTokenSource.Cancel();
Adapter = null;
MqttTrace.Information(nameof(MqttClientSession), "Client '{0}': Disconnected.", _identifier);
}
}
public async Task RunClientSessionAsync(MqttClientConnectedEventArgs eventArgs)
{
try
{
if (!(await eventArgs.ClientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout, CancellationToken.None).ConfigureAwait(false) is MqttConnectPacket connectPacket))
{
throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
}
// Switch to the required protocol version before sending any response.
eventArgs.ClientAdapter.PacketSerializer.ProtocolVersion = connectPacket.ProtocolVersion;
var connectReturnCode = ValidateConnection(connectPacket);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await eventArgs.ClientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
}).ConfigureAwait(false);
return;
}
var clientSession = GetOrCreateClientSession(connectPacket);
await eventArgs.ClientAdapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, CancellationToken.None, new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = clientSession.IsExistingSession
}).ConfigureAwait(false);
await clientSession.Session.RunAsync(eventArgs.Identifier, connectPacket.WillMessage, eventArgs.ClientAdapter).ConfigureAwait(false);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServer), exception, exception.Message);
}
finally
{
await eventArgs.ClientAdapter.DisconnectAsync(_options.DefaultCommunicationTimeout).ConfigureAwait(false);
}
}
private async Task AcceptTlsEndpointConnectionsAsync(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var clientSocket = await Task.Factory.FromAsync(_defaultEndpointSocket.BeginAccept, _defaultEndpointSocket.EndAccept, null);
var sslStream = new SslStream(new NetworkStream(clientSocket));
await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false);
var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, sslStream), new DefaultMqttV311PacketSerializer());
ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServerAdapter), exception, "Error while acceping connection at TLS endpoint.");
}
}
}
private async Task AcceptDefaultEndpointConnectionsAsync(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var clientSocket = await _defaultEndpointSocket.AcceptAsync().ConfigureAwait(false);
var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, null), new MqttPacketSerializer());
ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at default endpoint.");
//excessive CPU consumed if in endless loop of socket errors
await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
}
}
}
public void DispatchPublishPacket(MqttClientSession senderClientSession, MqttPublishPacket publishPacket)
{
try
{
var eventArgs = new MqttApplicationMessageReceivedEventArgs(senderClientSession?.ClientId, publishPacket.ToApplicationMessage());
ApplicationMessageReceived?.Invoke(this, eventArgs);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClientSessionsManager), exception, "Error while processing application message");
}
lock (_syncRoot)
{
foreach (var clientSession in _clientSessions.Values.ToList())
{
clientSession.EnqueuePublishPacket(publishPacket);
}
}
}
private async Task ReceivePackets(CancellationToken cancellationToken)
{
MqttTrace.Information(nameof(MqttClient), "Start receiving packets.");
try
{
while (!cancellationToken.IsCancellationRequested)
{
var packet = await _adapter.ReceivePacketAsync(TimeSpan.Zero, cancellationToken).ConfigureAwait(false);
if (cancellationToken.IsCancellationRequested)
{
return;
}
StartProcessReceivedPacket(packet, cancellationToken);
}
}
catch (TaskCanceledException)
{
}
catch (MqttCommunicationException exception)
{
if (cancellationToken.IsCancellationRequested)
{
return;
}
MqttTrace.Warning(nameof(MqttClient), exception, "MQTT communication exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Unhandled exception while receiving packets.");
await DisconnectInternalAsync().ConfigureAwait(false);
}
finally
{
MqttTrace.Information(nameof(MqttClient), "Stopped receiving packets.");
}
}
private async Task ProcessReceivedPacketAsync(MqttBasePacket packet)
{
try
{
MqttTrace.Information(nameof(MqttClient), "Received <<< {0}", packet);
if (packet is MqttPingReqPacket)
{
await SendAsync(new MqttPingRespPacket());
return;
}
if (packet is MqttDisconnectPacket)
{
await DisconnectAsync();
return;
}
if (packet is MqttPublishPacket publishPacket)
{
await ProcessReceivedPublishPacket(publishPacket);
return;
}
if (packet is MqttPubRelPacket pubRelPacket)
{
await ProcessReceivedPubRelPacket(pubRelPacket);
return;
}
_packetDispatcher.Dispatch(packet);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Unhandled exception while processing received packet.");
}
}
private async void ProcessReceivedPacket(MqttBasePacket mqttPacket)
{
try
{
if (mqttPacket is MqttPingReqPacket)
{
await SendAsync(new MqttPingRespPacket());
return;
}
if (mqttPacket is MqttDisconnectPacket)
{
await DisconnectAsync();
return;
}
var publishPacket = mqttPacket as MqttPublishPacket;
if (publishPacket != null)
{
await ProcessReceivedPublishPacket(publishPacket);
return;
}
var pubRelPacket = mqttPacket as MqttPubRelPacket;
if (pubRelPacket != null)
{
await ProcessReceivedPubRelPacket(pubRelPacket);
return;
}
_packetDispatcher.Dispatch(mqttPacket);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClient), exception, "Error while processing received packet.");
}
}
public async Task RunClientSessionAsync(MqttClientConnectedEventArgs eventArgs)
{
try
{
var connectPacket = await eventArgs.ClientAdapter.ReceivePacketAsync(_options.DefaultCommunicationTimeout) as MqttConnectPacket;
if (connectPacket == null)
{
throw new MqttProtocolViolationException("The first packet from a client must be a 'CONNECT' packet [MQTT-3.1.0-1].");
}
var connectReturnCode = ValidateConnection(connectPacket);
if (connectReturnCode != MqttConnectReturnCode.ConnectionAccepted)
{
await eventArgs.ClientAdapter.SendPacketAsync(new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode
}, _options.DefaultCommunicationTimeout);
return;
}
var clientSession = GetOrCreateClientSession(connectPacket);
await eventArgs.ClientAdapter.SendPacketAsync(new MqttConnAckPacket
{
ConnectReturnCode = connectReturnCode,
IsSessionPresent = clientSession.IsExistingSession
}, _options.DefaultCommunicationTimeout);
await clientSession.Session.RunAsync(eventArgs.Identifier, connectPacket.WillMessage, eventArgs.ClientAdapter);
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServer), exception, exception.Message);
}
finally
{
await eventArgs.ClientAdapter.DisconnectAsync();
}
}
private async Task SendPendingPublishPacketsAsync(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
await _gate.WaitOneAsync();
if (cancellationToken.IsCancellationRequested)
{
return;
}
if (_adapter == null)
{
continue;
}
List <MqttClientPublishPacketContext> pendingPublishPackets;
lock (_pendingPublishPackets)
{
pendingPublishPackets = _pendingPublishPackets.ToList();
}
foreach (var publishPacket in pendingPublishPackets)
{
await TrySendPendingPublishPacketAsync(publishPacket);
}
}
catch (Exception e)
{
MqttTrace.Error(nameof(MqttClientMessageQueue), e, "Error while sending pending publish packets.");
}
finally
{
Cleanup();
}
}
}
private async Task SendPendingPublishPacketsAsync(CancellationToken cancellationToken, IMqttCommunicationAdapter adapter)
{
var consumable = _pendingPublishPackets.GetConsumingEnumerable();
while (!cancellationToken.IsCancellationRequested)
{
if (_pendingPublishPackets.Count == 0)
{
await Task.Delay(TimeSpan.FromMilliseconds(5), cancellationToken).ConfigureAwait(false);
continue;
}
var packets = consumable.Take(_pendingPublishPackets.Count).ToList();
try
{
await adapter.SendPacketsAsync(_options.DefaultCommunicationTimeout, cancellationToken, packets).ConfigureAwait(false);
}
catch (MqttCommunicationException exception)
{
MqttTrace.Warning(nameof(MqttClientMessageQueue), exception, "Sending publish packet failed.");
foreach (var publishPacket in packets)
{
publishPacket.Dup = true;
_pendingPublishPackets.Add(publishPacket, cancellationToken);
}
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttClientMessageQueue), exception, "Sending publish packet failed.");
foreach (var publishPacket in packets)
{
publishPacket.Dup = true;
_pendingPublishPackets.Add(publishPacket, cancellationToken);
}
}
}
}
private async Task AcceptTlsEndpointConnectionsAsync(CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
var clientSocket = await _tlsEndpointSocket.AcceptAsync().ConfigureAwait(false);
var sslStream = new SslStream(new NetworkStream(clientSocket));
await sslStream.AuthenticateAsServerAsync(_tlsCertificate, false, SslProtocols.Tls12, false).ConfigureAwait(false);
var clientAdapter = new MqttChannelCommunicationAdapter(new MqttTcpChannel(clientSocket, sslStream), new MqttPacketSerializer());
ClientConnected?.Invoke(this, new MqttClientConnectedEventArgs(clientSocket.RemoteEndPoint.ToString(), clientAdapter));
}
catch (Exception exception)
{
MqttTrace.Error(nameof(MqttServerAdapter), exception, "Error while accepting connection at TLS endpoint.");
//excessive CPU consumed if in endless loop of socket errors
await Task.Delay(TimeSpan.FromSeconds(1), cancellationToken).ConfigureAwait(false);
}
}
}