//
// Constructor
//
public DataLinkProvider(String callSign, TNCChannel channel)
{
_localTncChannel = channel;
_localStationAddress = new StationAddress(callSign);
timerSegmenterHandler = new ElapsedEventHandler(timerSegmenter_Elapsed);
timerSegmenter = new Timer(timerSegmenterHandler, "UI Segmenter - " + _localStationAddress.stationIDString);
timerSegmenter.SetTime(1000 * 60 * 10); // 10 munite segmenter timeout
timerTestCommandTimeoutHandler = new ElapsedEventHandler(timerTestCommandTimeout_Elapsed);
timerTestCommandTimeout = new Timer(timerTestCommandTimeoutHandler, "TestCommandTimeout - " + _localStationAddress.stationIDString);
timerBeaconHandler = new ElapsedEventHandler(timerBeacon_Elapsed);
timerBeacon = new Timer(timerBeaconHandler, "Beacon for - " + _localStationAddress.stationIDString);
//
// Start processing
//
DataLinkThread = new Thread(ProcessDLPackets);
DataLinkThread.Name = "DataLinkProvider Packet Processing Thread for Station: " + _localStationAddress.stationIDString;
DataLinkThread.Start();
}
//
// Decode the received frame
//
Boolean Decode(out String packetFrame)
{
Int32 ptr = 0;
Boolean retVal = false;
StringBuilder s = new StringBuilder("|", 4096);
try
{
//
// Catch any exceptions during decode
//
ptr = staLink.destinationStation.Decode(inBuf, ptr);
ptr = staLink.sourceStation.Decode(inBuf, ptr);
s.Append("|" + staLink.sourceStation.stationIDString + "|ch=" + staLink.sourceStation.chBit.ToString());
s.Append("|" + staLink.destinationStation.stationIDString + "|ch=" + staLink.destinationStation.chBit.ToString());
if (staLink.sourceStation.extBit == 0)
{
ptr = staLink.relayStation1.Decode(inBuf, ptr);
s.Append("|" + staLink.relayStation1.stationIDString + "|ch=" + staLink.relayStation1.chBit.ToString());
if (staLink.relayStation1.extBit == 0)
{
ptr = staLink.relayStation2.Decode(inBuf, ptr);
s.Append("|" + staLink.relayStation2.stationIDString + "|ch=" + staLink.relayStation2.chBit.ToString());
if (staLink.relayStation2.extBit == 0)
{
StationAddress tmpR = new StationAddress();
s.Append("|r??:(");
do
{
ptr = tmpR.Decode(inBuf, ptr);
s.Append("\\" + tmpR.stationIDString + ":ch=" + tmpR.chBit.ToString());
} while (tmpR.extBit == 0);
s.Append(")");
//throw new Exception("Too many relay addresses");
}
else
{
s.Append("|");
}
}
else
{
s.Append("||");
}
}
else
{
s.Append("|||");
}
cmdOctetPtr = ptr;
if ((staLink.destinationStation.chBit == staLink.sourceStation.chBit))
{
//
// Old protocol version
//
version = ProtocolVersion.V20;
}
else
{
//
// New protocol version
//
version = ProtocolVersion.V22;
}
if (staLink.destinationStation.chBit == 0)
{
//
// Response type
//
cmdResp = PacketType.Response;
}
else
{
//
// Command type
//
cmdResp = PacketType.Command;
}
//
// Get frame type. I and S frame must be decoded later after we know whether we
// are using mod8 or mod128 sequence numbers.
//
Byte tmp = inBuf[ptr];
String t = "";
pfBit = (tmp >> 4) & 0x01; //ToDo change needed to support SABME
seqNumMode = SequenceNumberMode.Mod8;
//Frame.InformationFrame.Decode(this, rawBuf, ptr, out t);
if ((tmp & 0x01) == I)
{
//
// I frame
//
frameClass = FrameClasses.IClass;
frameType = FrameTypes.IType;
ptr = InformationFrame.Decode(this, inBuf, ptr, out t);
}
if ((tmp & 0x03) == S)
{
//
// S frame
//
frameClass = FrameClasses.SClass;
frameType = (FrameTypes)(tmp & 0x0f);
ptr = SupervisoryFrame.Decode(this, inBuf, ptr, out t);
}
if ((tmp & 0x03) == U)
{
//
// U frame. We can decode uFrames right away
//
frameClass = FrameClasses.UClass;
frameType = (FrameTypes)(tmp & 0xef);
ptr = UnnumberedFrame.Decode(this, inBuf, ptr, out t);
}
s.Append("|" + version.ToString() + "|" + frameType.ToString() + "|" + cmdResp.ToString() + "|pf=" + pfBit.ToString());
if (t.Length > 0)
{
s.Append(t);
}
s.Append(Support.DumpRawFrame(rawBuf));
retVal = true;
}
catch (Exception ex)
{
s.Append(ex.Message + CRLF);
Support.DbgPrint("Exception during frame decode:" + ex.Message + CRLF);
retVal = false;
}
finally
{
s.Append("]");
packetFrame = s.ToString();
}
return(retVal);
}
