private void ProcessAndPush(PacketBuffer Buffer, MemoryStream PacketStream)
{
int hdrLen = DtmPacketStruct.GetHeaderSize();
int pktLen = 0;
// get the header
DtmPacketStruct pktHdr = new DtmPacketStruct(PacketStream);
PacketStream.Seek(0, SeekOrigin.Begin);
// track high sequence number
if (pktHdr.Sequence > _seqCounter)
{
_seqCounter = pktHdr.Sequence;
}
// out of sync, possible packet loss
if (_seqCounter - _rcvSequence > _bufferCount / 4)
{
// request a retransmission
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, _rcvSequence + 1);
}
// packet aligned
if (pktHdr.PayloadLength + hdrLen == PacketStream.Length)
{
// resend was already processed
if (pktHdr.Sequence < _rcvSequence)
{
return;
}
// push onto buffer
Buffer.Push(pktHdr.Sequence, PacketStream);
}
// more than one packet
else if (pktHdr.PayloadLength + hdrLen < PacketStream.Length)
{
byte[] buffer;
long pos = 0;
do
{
// get packet position and size
pos = PacketStream.Position;
if (PacketStream.Length - pos < DtmPacketStruct.GetHeaderSize())
{
// next packet corrupted, request a retransmission and exit
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
pktHdr = new DtmPacketStruct(PacketStream);
pktLen = (int)(hdrLen + pktHdr.PayloadLength);
if (pktLen > MAXRCVBUFFER || pktLen < 0 || PacketStream.Length - pos < pktLen)
{
// packet corrupted, request a retransmission and exit
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
return;
}
else
{
// create the buffer
buffer = new byte[pktLen];
PacketStream.Seek(pos, SeekOrigin.Begin);
PacketStream.Read(buffer, 0, (int)pktLen);
// push onto buffer
Buffer.Push(pktHdr.Sequence, new MemoryStream(buffer));
}
} while (PacketStream.Position < PacketStream.Length);
}
// malformed packet, send retransmit request
else if (pktHdr.PayloadLength > MAXRCVBUFFER || pktHdr.PayloadLength < 0 || pktHdr.PayloadLength + hdrLen > PacketStream.Length)
{
// packet corrupted, request a retransmission of last in queue + 1
Transmit(DtmPacketFlags.Service, (short)DtmServiceFlags.Resend, Buffer.GetHighKey() + 1);
}
}