public async Task HandleClientConnectionAsync(IMqttChannelAdapter channelAdapter, CancellationToken cancellationToken)
{
MqttClient client = null;
try
{
var connectPacket = await ReceiveConnectPacket(channelAdapter, cancellationToken).ConfigureAwait(false);
if (connectPacket == null)
{
// Nothing was received in time etc.
return;
}
var validatingConnectionEventArgs = await ValidateConnection(connectPacket, channelAdapter).ConfigureAwait(false);
var connAckPacket = _packetFactories.ConnAck.Create(validatingConnectionEventArgs);
if (validatingConnectionEventArgs.ReasonCode != MqttConnectReasonCode.Success)
{
// Send failure response here without preparing a connection and session!
await channelAdapter.SendPacketAsync(connAckPacket, cancellationToken).ConfigureAwait(false);
return;
}
// Pass connAckPacket so that IsSessionPresent flag can be set if the client session already exists.
client = await CreateClientConnection(connectPacket, connAckPacket, channelAdapter, validatingConnectionEventArgs).ConfigureAwait(false);
await client.SendPacketAsync(connAckPacket, cancellationToken).ConfigureAwait(false);
if (_eventContainer.ClientConnectedEvent.HasHandlers)
{
var eventArgs = new ClientConnectedEventArgs
{
ClientId = connectPacket.ClientId,
UserName = connectPacket.Username,
ProtocolVersion = channelAdapter.PacketFormatterAdapter.ProtocolVersion,
Endpoint = channelAdapter.Endpoint
};
await _eventContainer.ClientConnectedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
}
await client.RunAsync().ConfigureAwait(false);
}
catch (OperationCanceledException)
{
}
catch (Exception exception)
{
_logger.Error(exception, exception.Message);
}
finally
{
if (client != null)
{
if (client.Id != null)
{
// in case it is a takeover _clientConnections already contains the new connection
if (!client.IsTakenOver)
{
lock (_clients)
{
_clients.Remove(client.Id);
}
if (!_options.EnablePersistentSessions || !client.Session.IsPersistent)
{
await DeleteSessionAsync(client.Id).ConfigureAwait(false);
}
}
}
var endpoint = client.Endpoint;
if (client.Id != null && !client.IsTakenOver && _eventContainer.ClientDisconnectedEvent.HasHandlers)
{
var eventArgs = new ClientDisconnectedEventArgs
{
ClientId = client.Id,
DisconnectType = client.IsCleanDisconnect ? MqttClientDisconnectType.Clean : MqttClientDisconnectType.NotClean,
Endpoint = endpoint
};
await _eventContainer.ClientDisconnectedEvent.InvokeAsync(eventArgs).ConfigureAwait(false);
}
}
using (var timeout = new CancellationTokenSource(_options.DefaultCommunicationTimeout))
{
await channelAdapter.DisconnectAsync(timeout.Token).ConfigureAwait(false);
}
}
}