public ArraySegment <byte> Encode(MqttBasePacket packet)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
// Leave enough head space for max header size (fixed + 4 variable remaining length = 5 bytes)
_packetWriter.Reset(5);
_packetWriter.Seek(5);
var fixedHeader = EncodePacket(packet, _packetWriter);
var remainingLength = (uint)(_packetWriter.Length - 5);
var remainingLengthSize = MqttPacketWriter.GetLengthOfVariableInteger(remainingLength);
var headerSize = 1 + remainingLengthSize;
var headerOffset = 5 - headerSize;
// Position cursor on correct offset on beginning of array (has leading 0x0)
_packetWriter.Seek(headerOffset);
_packetWriter.Write(fixedHeader);
_packetWriter.WriteVariableLengthInteger(remainingLength);
var buffer = _packetWriter.GetBuffer();
return(new ArraySegment <byte>(buffer, headerOffset, _packetWriter.Length - headerOffset));
}
private static byte EncodeUnsubscribePacket(MqttUnsubscribePacket packet, IMqttPacketWriter packetWriter)
{
if (packet.TopicFilters?.Any() != true)
{
throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.10.3-2].");
}
ThrowIfPacketIdentifierIsInvalid(packet);
packetWriter.Write(packet.PacketIdentifier.Value);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
foreach (var topicFilter in packet.TopicFilters)
{
packetWriter.WriteWithLengthPrefix(topicFilter);
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Unsubscibe, 0x02));
}
static byte EncodePublishPacket(MqttPublishPacket packet, IMqttPacketWriter packetWriter)
{
ValidatePublishPacket(packet);
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 empty if QoS == 0 [MQTT-2.3.1-5].");
}
}
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));
}
static byte EncodeUnsubAckPacket(MqttUnsubAckPacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("UnsubAck packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.UnsubAck));
}
static byte EncodeSubAckPacket(MqttSubAckPacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("SubAck packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
if (packet.ReturnCodes?.Any() == true)
{
foreach (var packetSubscribeReturnCode in packet.ReturnCodes)
{
packetWriter.Write((byte)packetSubscribeReturnCode);
}
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.SubAck));
}
public void WriteTo(IMqttPacketWriter packetWriter)
{
if (packetWriter == null)
{
throw new ArgumentNullException(nameof(packetWriter));
}
packetWriter.WriteVariableLengthInteger((uint)_packetWriter.Length);
packetWriter.Write(_packetWriter);
}
private static byte EncodePubCompPacket(MqttPubCompPacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("PubComp packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.PubComp));
}
static byte EncodePubRecPacket(MqttPubRecPacket packet, IMqttPacketWriter packetWriter)
{
if (packet.PacketIdentifier == 0)
{
throw new MqttProtocolViolationException("PubRec packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier);
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.PubRec));
}
static byte EncodeSubscribePacket(MqttSubscribePacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.TopicFilters.Any())
{
throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.8.3-3].");
}
if (packet.PacketIdentifier == 0)
{
throw new MqttProtocolViolationException("Subscribe packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier);
if (packet.TopicFilters?.Count > 0)
{
foreach (var topicFilter in packet.TopicFilters)
{
if (topicFilter.NoLocal)
{
throw new MqttProtocolViolationException("NoLocal is not supported in 3.1.1.");
}
if (topicFilter.RetainAsPublished)
{
throw new MqttProtocolViolationException("RetainAsPublished is not supported in 3.1.1.");
}
if (topicFilter.RetainHandling != MqttRetainHandling.SendAtSubscribe)
{
throw new MqttProtocolViolationException("RetainHandling is not supported in 3.1.1.");
}
packetWriter.WriteWithLengthPrefix(topicFilter.Topic);
packetWriter.Write((byte)topicFilter.QualityOfServiceLevel);
}
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Subscribe, 0x02));
}
private static byte EncodePubAckPacket(MqttPubAckPacket packet, IMqttPacketWriter packetWriter)
{
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
if (packetWriter == null)
{
throw new ArgumentNullException(nameof(packetWriter));
}
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("PubAck packet has no packet identifier.");
}
if (!packet.ReasonCode.HasValue)
{
throw new MqttProtocolViolationException("PubAck packet must contain a reason code.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WriteReasonString(packet.Properties.ReasonString);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
if (packetWriter.Length > 0 || packet.ReasonCode.Value != MqttPubAckReasonCode.Success)
{
packetWriter.Write((byte)packet.ReasonCode.Value);
propertiesWriter.WriteTo(packetWriter);
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.PubAck));
}
private static byte EncodeAuthPacket(MqttAuthPacket packet, IMqttPacketWriter packetWriter)
{
packetWriter.Write((byte)packet.ReasonCode);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WriteAuthenticationMethod(packet.Properties.AuthenticationMethod);
propertiesWriter.WriteAuthenticationData(packet.Properties.AuthenticationData);
propertiesWriter.WriteReasonString(packet.Properties.ReasonString);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Auth));
}
private static byte EncodeDisconnectPacket(MqttDisconnectPacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.ReasonCode.HasValue)
{
ThrowReasonCodeNotSetException();
}
packetWriter.Write((byte)packet.ReasonCode.Value);
var propertiesWriter = new MqttV500PropertiesWriter();
if (packet.Properties != null)
{
propertiesWriter.WriteServerReference(packet.Properties.ServerReference);
propertiesWriter.WriteReasonString(packet.Properties.ReasonString);
propertiesWriter.WriteSessionExpiryInterval(packet.Properties.SessionExpiryInterval);
propertiesWriter.WriteUserProperties(packet.Properties.UserProperties);
}
propertiesWriter.WriteTo(packetWriter);
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Disconnect));
}
static byte EncodeUnsubscribePacket(MqttUnsubscribePacket packet, IMqttPacketWriter packetWriter)
{
if (!packet.TopicFilters.Any())
{
throw new MqttProtocolViolationException("At least one topic filter must be set [MQTT-3.10.3-2].");
}
if (!packet.PacketIdentifier.HasValue)
{
throw new MqttProtocolViolationException("Unsubscribe packet has no packet identifier.");
}
packetWriter.Write(packet.PacketIdentifier.Value);
if (packet.TopicFilters?.Any() == true)
{
foreach (var topicFilter in packet.TopicFilters)
{
packetWriter.WriteWithLengthPrefix(topicFilter);
}
}
return(MqttPacketWriter.BuildFixedHeader(MqttControlPacketType.Unsubscibe, 0x02));
}
protected virtual byte EncodeConnectPacket(MqttConnectPacket packet, IMqttPacketWriter packetWriter)
{
ValidateConnectPacket(packet);
packetWriter.WriteWithLengthPrefix("MQIsdp");
packetWriter.Write(3); // Protocol Level 3
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);
packetWriter.WriteWithLengthPrefix(packet.ClientId);
if (packet.WillMessage != null)
{
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 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));
}
