/**
* create the right type of control packet based on the packet data
* @param packetData
* @return
*/
public static ControlPacket CreateControlPacket(byte[] encodedData, int length)
{
ControlPacket packet = null;
int pktType = PacketUtil.DecodeType(encodedData, 0);
long additionalInfo = PacketUtil.Decode(encodedData, 4);
long timeStamp = PacketUtil.Decode(encodedData, 8);
long destID = PacketUtil.Decode(encodedData, 12);
byte[] controlInformation = new byte[length - 16];
Array.Copy(encodedData, 16, controlInformation, 0, controlInformation.Length);
//TYPE 0000:0
if ((int)ControlPacketType.CONNECTION_HANDSHAKE == pktType)
{
packet = new ConnectionHandshake(controlInformation);
}
//TYPE 0001:1
else if ((int)ControlPacketType.KEEP_ALIVE == pktType)
{
packet = new KeepAlive();
}
//TYPE 0010:2
else if ((int)ControlPacketType.ACK == pktType)
{
packet = new Acknowledgement(additionalInfo, controlInformation);
}
//TYPE 0011:3
else if ((int)ControlPacketType.NAK == pktType)
{
packet = new NegativeAcknowledgement(controlInformation);
}
//TYPE 0101:5
else if ((int)ControlPacketType.SHUTDOWN == pktType)
{
packet = new Shutdown();
}
//TYPE 0110:6
else if ((int)ControlPacketType.ACK2 == pktType)
{
packet = new Acknowledgment2(additionalInfo, controlInformation);
}
//TYPE 0111:7
else if ((int)ControlPacketType.MESSAGE_DROP_REQUEST == pktType)
{
packet = new MessageDropRequest(controlInformation);
}
//TYPE 1111:8
else if ((int)ControlPacketType.USER_DEFINED == pktType)
{
packet = new UserDefined(controlInformation);
}
if (packet != null)
{
packet.TimeStamp = timeStamp;
packet.DestinationID = destID;
}
return(packet);
}
void Decode(byte[] data)
{
udtVersion = PacketUtil.Decode(data, 0);
socketType = PacketUtil.Decode(data, 4);
initialSeqNo = PacketUtil.Decode(data, 8);
packetSize = PacketUtil.Decode(data, 12);
maxFlowWndSize = PacketUtil.Decode(data, 16);
connectionType = PacketUtil.Decode(data, 20);
socketID = PacketUtil.Decode(data, 24);
if (data.Length > 28)
{
cookie = PacketUtil.Decode(data, 28);
}
if (data.Length > 32)
{
//IP6
peerIP[0] = PacketUtil.Decode(data, 32);
peerIP[1] = PacketUtil.Decode(data, 36);
peerIP[2] = PacketUtil.Decode(data, 40);
peerIP[3] = PacketUtil.Decode(data, 44);
}
}
void Decode(byte[] encodedData, int length)
{
packetSequenceNumber = PacketUtil.Decode(encodedData, 0);
messageNumber = PacketUtil.Decode(encodedData, 4);
timeStamp = PacketUtil.Decode(encodedData, 8);
destinationID = PacketUtil.Decode(encodedData, 12);
data = new byte[length - 16];
Array.Copy(encodedData, 16, data, 0, data.Length);
}
void DecodeControlInformation(byte[] data)
{
ackNumber = PacketUtil.Decode(data, 0);
if (data.Length > 4)
{
roundTripTime = PacketUtil.Decode(data, 4);
roundTripTimeVariance = PacketUtil.Decode(data, 8);
bufferSize = PacketUtil.Decode(data, 12);
}
if (data.Length > 16)
{
pktArrivalSpeed = PacketUtil.Decode(data, 16);
estimatedLinkCapacity = PacketUtil.Decode(data, 20);
}
}
void decode(byte[] data)
{
msgFirstSeqNo = PacketUtil.Decode(data, 0);
msgLastSeqNo = PacketUtil.Decode(data, 4);
}