static void DecodeConnAckPacket(DataReader buffer, FbnsConnAckPacket packet, ref int remainingLength)
{
packet.ConnAckFlags = buffer.ReadByte();
packet.ReturnCode = (ConnectReturnCode)buffer.ReadByte();
remainingLength -= 2;
if (remainingLength > 0)
{
var authSize = buffer.ReadUInt16();
packet.Authentication = buffer.ReadString(authSize);
remainingLength -= authSize + 2;
if (remainingLength > 0)
{
Debug.WriteLine($"{nameof(StandalonePacketDecoder)} Unhandled data in the buffer. Length of remaining data = {remainingLength}");
}
}
}
public static Packet DecodePacket(DataReader reader)
{
reader.ByteOrder = ByteOrder.BigEndian;
int signature = reader.ReadByte();
int remainingLength = DecodeRemainingLength(reader);
if (Signatures.IsPublish(signature))
{
var qualityOfService =
(QualityOfService)((signature >> 1) &
0x3); // take bits #1 and #2 ONLY and convert them into QoS value
if (qualityOfService == QualityOfService.Reserved)
{
throw new Exception(
$"Unexpected QoS value of {(int)qualityOfService} for {PacketType.PUBLISH} packet.");
}
bool duplicate = (signature & 0x8) == 0x8; // test bit#3
bool retain = (signature & 0x1) != 0; // test bit#0
var packet = new PublishPacket(qualityOfService, duplicate, retain);
DecodePublishPacket(reader, packet, ref remainingLength);
return(packet);
}
switch (signature & 240) // We don't care about flags for these packets
{
// case Signatures.Subscribe & 240:
// var subscribePacket = new SubscribePacket();
// DecodePacketIdVariableHeader(reader, subscribePacket, ref remainingLength);
// DecodeSubscribePayload(buffer, subscribePacket, ref remainingLength);
// return subscribePacket;
case Signatures.Connect:
var connectPacket = new ConnectPacket();
DecodeConnectPacket(reader, connectPacket, ref remainingLength);
return(connectPacket);
case Signatures.PubAck:
var pubAckPacket = new PubAckPacket();
DecodePacketIdVariableHeader(reader, pubAckPacket, ref remainingLength);
return(pubAckPacket);
case Signatures.ConnAck:
var connAckPacket = new FbnsConnAckPacket();
DecodeConnAckPacket(reader, connAckPacket, ref remainingLength);
return(connAckPacket);
case Signatures.SubAck:
var subAckPacket = new SubAckPacket();
DecodePacketIdVariableHeader(reader, subAckPacket, ref remainingLength);
DecodeSubAckPayload(reader, subAckPacket, ref remainingLength);
return(subAckPacket);
case Signatures.UnsubAck:
var unsubAckPacket = new UnsubAckPacket();
DecodePacketIdVariableHeader(reader, unsubAckPacket, ref remainingLength);
return(unsubAckPacket);
case Signatures.PingResp:
return(PingRespPacket.Instance);
default:
throw new Exception($"Packet type {signature} not supported");
}
}