// ReSharper disable once ParameterOnlyUsedForPreconditionCheck.Local
private static void ThrowIfBodyIsEmpty(MqttPacketBodyReader body)
{
if (body == null || body.Length == 0)
{
throw new MqttProtocolViolationException("Data from the body is required but not present.");
}
}
private static MqttBasePacket DeserializePubAck(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
return(new MqttPubAckPacket
{
PacketIdentifier = body.ReadUInt16()
});
}
private static MqttBasePacket DeserializeSubAck(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
var packet = new MqttSubAckPacket
{
PacketIdentifier = body.ReadUInt16()
};
while (!body.EndOfStream)
{
packet.SubscribeReturnCodes.Add((MqttSubscribeReturnCode)body.ReadByte());
}
return(packet);
}
private static MqttBasePacket DeserializeUnsubscribe(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
var packet = new MqttUnsubscribePacket
{
PacketIdentifier = body.ReadUInt16(),
};
while (!body.EndOfStream)
{
packet.TopicFilters.Add(body.ReadStringWithLengthPrefix());
}
return(packet);
}
private MqttBasePacket DeserializeConnAck(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
var packet = new MqttConnAckPacket();
var acknowledgeFlags = body.ReadByte();
if (ProtocolVersion == MqttProtocolVersion.V311)
{
packet.IsSessionPresent = (acknowledgeFlags & 0x1) > 0;
}
packet.ConnectReturnCode = (MqttConnectReturnCode)body.ReadByte();
return(packet);
}
private static MqttBasePacket DeserializeSubscribe(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
var packet = new MqttSubscribePacket
{
PacketIdentifier = body.ReadUInt16()
};
while (!body.EndOfStream)
{
packet.TopicFilters.Add(new TopicFilter(
body.ReadStringWithLengthPrefix(),
(MqttQualityOfServiceLevel)body.ReadByte()));
}
return(packet);
}
private static MqttBasePacket DeserializeConnect(MqttPacketBodyReader body)
{
ThrowIfBodyIsEmpty(body);
var protocolName = body.ReadStringWithLengthPrefix();
MqttProtocolVersion protocolVersion;
if (protocolName == "MQTT")
{
var protocolLevel = body.ReadByte();
if (protocolLevel != 4)
{
throw new MqttProtocolViolationException($"Protocol level ({protocolLevel}) not supported for MQTT 3.1.1.");
}
protocolVersion = MqttProtocolVersion.V311;
}
else if (protocolName == "MQIsdp")
{
var protocolLevel = body.ReadByte();
if (protocolLevel != 3)
{
throw new MqttProtocolViolationException($"Protocol level ({protocolLevel}) not supported for MQTT 3.1.");
}
protocolVersion = MqttProtocolVersion.V310;
}
else
{
throw new MqttProtocolViolationException($"Protocol name ({protocolName}) is not supported.");
}
var connectFlags = body.ReadByte();
if ((connectFlags & 0x1) > 0)
{
throw new MqttProtocolViolationException("The first bit of the Connect Flags must be set to 0.");
}
var packet = new MqttConnectPacket
{
ProtocolVersion = protocolVersion,
CleanSession = (connectFlags & 0x2) > 0
};
var willFlag = (connectFlags & 0x4) > 0;
var willQoS = (connectFlags & 0x18) >> 3;
var willRetain = (connectFlags & 0x20) > 0;
var passwordFlag = (connectFlags & 0x40) > 0;
var usernameFlag = (connectFlags & 0x80) > 0;
packet.KeepAlivePeriod = body.ReadUInt16();
packet.ClientId = body.ReadStringWithLengthPrefix();
if (willFlag)
{
packet.WillMessage = new MqttApplicationMessage
{
Topic = body.ReadStringWithLengthPrefix(),
Payload = body.ReadWithLengthPrefix().ToArray(),
QualityOfServiceLevel = (MqttQualityOfServiceLevel)willQoS,
Retain = willRetain
};
}
if (usernameFlag)
{
packet.Username = body.ReadStringWithLengthPrefix();
}
if (passwordFlag)
{
packet.Password = body.ReadStringWithLengthPrefix();
}
ValidateConnectPacket(packet);
return(packet);
}