public DataChunk(byte flags, int length, ByteBuffer pkt) : base(ChunkType.DATA, flags, length, pkt)
{
//logger.LogDebug("read in chunk header " + length);
//logger.LogDebug("body remaining " + _body.remaining());
if (_body.remaining() >= 12)
{
_tsn = _body.GetUInt();
_streamId = _body.GetUShort();
_sSeqNo = _body.GetUShort();
_ppid = _body.GetInt();
//logger.LogDebug(" _tsn : " + _tsn
// + " _streamId : " + _streamId
// + " _sSeqNo : " + _sSeqNo
// + " _ppid : " + _ppid);
//logger.LogDebug("data size remaining " + _body.remaining());
switch (_ppid)
{
case WEBRTCCONTROL:
ByteBuffer bb = _body.slice();
try
{
_open = new DataChannelOpen(bb);
}
catch (InvalidDataChunkException ex)
{
_invalid = ex;
}
//logger.LogDebug("Got an DCEP " + _open);
break;
case WEBRTCstring:
// what format is a string ?
_data = new byte[_body.remaining()];
_body.GetBytes(_data, _data.Length);
_dataOffset = 0;
_dataLength = _data.Length;
//logger.LogDebug("string data is " + Encoding.ASCII.GetString(_data));
break;
case WEBRTCBINARY:
_data = new byte[_body.remaining()];
_body.GetBytes(_data, _data.Length);
_dataOffset = 0;
_dataLength = _data.Length;
//logger.LogDebug("data is " + Packet.getHex(_data));
break;
default:
logger.LogWarning($"Invalid payload protocol identifier Id in data chunk, ppid {_ppid}.");
_invalid = new InvalidDataChunkException(
$"Invalid payload protocol identifier in data chunk, ppid {_ppid}.");
break;
}
}
}
public static DataChunk mkDataChannelOpen(string label)
{
DataChunk open = new DataChunk();
DataChannelOpen dope = new DataChannelOpen(label);
open.setData(dope.getBytes());
open._ppid = WEBRTCCONTROL;
open.setFlags(SINGLEFLAG);
return(open);
}
public DataChunk mkAck(DataChannelOpen dcep)
{
DataChunk ack = new DataChunk();
ack.setData(dcep.mkAck());
ack._ppid = WEBRTCCONTROL;
ack.setFlags(SINGLEFLAG);
return(ack);
}
// todo should be in a behave block
// then we wouldn't be messing with stream seq numbers.
private Chunk[] dcepDeal(SCTPStream s, DataChunk dc, DataChannelOpen dcep)
{
Chunk[] rep = null;
//logger.LogDebug("dealing with a decp for stream " + dc.getDataAsString());
if (!dcep.isAck())
{
//logger.LogDebug("decp is not an ack... ");
SCTPStreamBehaviour behave = dcep.mkStreamBehaviour();
s.setBehave(behave);
s.setLabel(dcep.getLabel());
lock (s)
{
int seqIn = s.getNextMessageSeqIn();
s.setNextMessageSeqIn(seqIn + 1);
int seqOut = s.getNextMessageSeqOut();
s.setNextMessageSeqOut(seqOut + 1);
}
rep = new Chunk[1];
DataChunk ack = dc.mkAck(dcep);
s.outbound(ack);
ack.setTsn(_nearTSN++);
// check rollover - will break at maxint.
rep[0] = ack;
}
else
{
//logger.LogDebug("got a dcep ack for " + s.getLabel());
SCTPStreamBehaviour behave = dcep.mkStreamBehaviour();
s.setBehave(behave);
lock (s)
{
int seqIn = s.getNextMessageSeqIn();
s.setNextMessageSeqIn(seqIn + 1);
int seqOut = s.getNextMessageSeqOut();
s.setNextMessageSeqOut(seqOut + 1);
}
}
return(rep);
}
