async Task <MqttPacket> InterceptPacketAsync(MqttPacket packet, CancellationToken cancellationToken)
{
if (!_eventContainer.InterceptingOutboundPacketEvent.HasHandlers)
{
return(packet);
}
var interceptingPacketEventArgs = new InterceptingPacketEventArgs
{
ClientId = Id,
Endpoint = Endpoint,
Packet = packet,
CancellationToken = cancellationToken
};
await _eventContainer.InterceptingOutboundPacketEvent.InvokeAsync(interceptingPacketEventArgs).ConfigureAwait(false);
if (!interceptingPacketEventArgs.ProcessPacket || packet == null)
{
return(null);
}
return(interceptingPacketEventArgs.Packet);
}
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)
{
return;
}
var processPacket = true;
if (_eventContainer.InterceptingInboundPacketEvent.HasHandlers)
{
var interceptingPacketEventArgs = new InterceptingPacketEventArgs
{
ClientId = Id,
Endpoint = Endpoint,
Packet = packet,
CancellationToken = cancellationToken
};
await _eventContainer.InterceptingInboundPacketEvent.InvokeAsync(interceptingPacketEventArgs).ConfigureAwait(false);
packet = interceptingPacketEventArgs.Packet;
processPacket = interceptingPacketEventArgs.ProcessPacket;
}
if (!processPacket || packet == null)
{
// Restart the receiving process to get the next packet ignoring the current one..
continue;
}
Statistics.HandleReceivedPacket(packet);
if (packet is MqttPublishPacket publishPacket)
{
await HandleIncomingPublishPacket(publishPacket, cancellationToken).ConfigureAwait(false);
}
else if (packet is MqttPubAckPacket pubAckPacket)
{
Session.AcknowledgePublishPacket(pubAckPacket.PacketIdentifier);
}
else if (packet is MqttPubCompPacket pubCompPacket)
{
Session.AcknowledgePublishPacket(pubCompPacket.PacketIdentifier);
}
else if (packet is MqttPubRecPacket pubRecPacket)
{
HandleIncomingPubRecPacket(pubRecPacket);
}
else if (packet is MqttPubRelPacket pubRelPacket)
{
HandleIncomingPubRelPacket(pubRelPacket);
}
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].
Session.EnqueueHealthPacket(new MqttPacketBusItem(MqttPingRespPacket.Instance));
}
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.", Id);
}
else
{
_logger.Error(exception, "Client '{0}': Error while receiving client packets.", Id);
}
}
}