private static byte EncodeConnectPacket(MqttConnectPacket packet, IMqttPacketWriter packetWriter)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packetWriter == null)
{
throw new ArgumentNullException(nameof(packetWriter));
}
if (string.IsNullOrEmpty(packet.ClientId) && !packet.CleanSession)
{
throw new MqttProtocolViolationException("CleanSession must be set if ClientId is empty [MQTT-3.1.3-7].");
}
packetWriter.WriteWithLengthPrefix("MQTT");
packetWriter.Write(5); // [3.1.2.2 Protocol Version]
byte connectFlags = 0x0;
if (packet.CleanSession)
{
connectFlags |= 0x2;
}
if (packet.WillMessage != null)
{
connectFlags |= 0x4;
connectFlags |= (byte)((byte)packet.WillMessage.QualityOfServiceLevel << 3);
if (packet.WillMessage.Retain)
{
connectFlags |= 0x20;
}
}
if (packet.Password != null && packet.Username == null)
{
throw new MqttProtocolViolationException("If the User Name Flag is set to 0, the Password Flag MUST be set to 0 [MQTT-3.1.2-22].");
}
if (packet.Password != null)
{
connectFlags |= 0x40;
}
if (packet.Username != null)
{
connectFlags |= 0x80;
}
packetWriter.Write(connectFlags);
packetWriter.Write(packet.KeepAlivePeriod);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WriteSessionExpiryInterval(packet.Properties.SessionExpiryInterval);
propertiesWriter.WriteAuthenticationMethod(packet.Properties.AuthenticationMethod);
propertiesWriter.WriteAuthenticationData(packet.Properties.AuthenticationData);
propertiesWriter.WriteRequestProblemInformation(packet.Properties.RequestProblemInformation);
propertiesWriter.WriteRequestResponseInformation(packet.Properties.RequestResponseInformation);
propertiesWriter.WriteReceiveMaximum(packet.Properties.ReceiveMaximum);
propertiesWriter.WriteTopicAliasMaximum(packet.Properties.TopicAliasMaximum);
propertiesWriter.WriteMaximumPacketSize(packet.Properties.MaximumPacketSize);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
packetWriter.WriteWithLengthPrefix(packet.ClientId);
if (packet.WillMessage != null)
{
var willPropertiesWriter = new MqttV500PropertiesWriter();
willPropertiesWriter.WritePayloadFormatIndicator(packet.WillMessage.PayloadFormatIndicator);
willPropertiesWriter.WriteMessageExpiryInterval(packet.WillMessage.MessageExpiryInterval);
willPropertiesWriter.WriteTopicAlias(packet.WillMessage.TopicAlias);
willPropertiesWriter.WriteResponseTopic(packet.WillMessage.ResponseTopic);
willPropertiesWriter.WriteCorrelationData(packet.WillMessage.CorrelationData);
willPropertiesWriter.WriteSubscriptionIdentifiers(packet.WillMessage.SubscriptionIdentifiers);
willPropertiesWriter.WriteContentType(packet.WillMessage.ContentType);
willPropertiesWriter.WriteUserProperties(packet.WillMessage.UserProperties);
// This is a special case!
willPropertiesWriter.WriteWillDelayInterval(packet.Properties?.WillDelayInterval);
willPropertiesWriter.WriteTo(packetWriter);
packetWriter.WriteWithLengthPrefix(packet.WillMessage.Topic);
packetWriter.WriteWithLengthPrefix(packet.WillMessage.Payload);
}
if (packet.Username != null)
{
packetWriter.WriteWithLengthPrefix(packet.Username);
}
if (packet.Password != null)
{
packetWriter.WriteWithLengthPrefix(packet.Password);
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Connect));
}
private static byte EncodePublishPacket(MqttPublishPacket packet, IMqttPacketWriter packetWriter)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packetWriter == null)
{
throw new ArgumentNullException(nameof(packetWriter));
}
if (packet.QualityOfServiceLevel == 0 && packet.Dup)
{
throw new MqttProtocolViolationException("Dup flag must be false for QoS 0 packets [MQTT-3.3.1-2].");
}
packetWriter.WriteWithLengthPrefix(packet.Topic);
if (packet.QualityOfServiceLevel > MqttQualityOfServiceLevel.AtMostOnce)
{
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("Publish packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
}
else
{
if (packet.PacketIdentifier > 0)
{
throw new MqttProtocolViolationException("Packet identifier must be 0 if QoS == 0 [MQTT-2.3.1-5].");
}
}
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WritePayloadFormatIndicator(packet.Properties.PayloadFormatIndicator);
propertiesWriter.WriteMessageExpiryInterval(packet.Properties.MessageExpiryInterval);
propertiesWriter.WriteTopicAlias(packet.Properties.TopicAlias);
propertiesWriter.WriteResponseTopic(packet.Properties.ResponseTopic);
propertiesWriter.WriteCorrelationData(packet.Properties.CorrelationData);
propertiesWriter.WriteSubscriptionIdentifiers(packet.Properties.SubscriptionIdentifiers);
propertiesWriter.WriteContentType(packet.Properties.ContentType);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
if (packet.Payload?.Length > 0)
{
packetWriter.Write(packet.Payload, 0, packet.Payload.Length);
}
byte fixedHeader = 0;
if (packet.Retain)
{
fixedHeader |= 0x01;
}
fixedHeader |= (byte)((byte)packet.QualityOfServiceLevel << 1);
if (packet.Dup)
{
fixedHeader |= 0x08;
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Publish, fixedHeader));
}