/// <summary>
/// Should always be invoked by other overload method.
/// </summary>
/// <param name="segs"></param>
/// <param name="tpktLen"></param>
/// <param name="segLen"></param>
private void BuildSegments(ByteArraySegment segs, int tpktLen, int segLen)
{
if (tpktLen > segLen)
{
// The begin of next frame packet tcp payload is a successor of THIS segment.
NextFrameSegmentLength = tpktLen - segLen;
LastSegment = false;
segs.Length = segLen;
TpktSegments.Add(new TpktSegment(segs, true));
}
else if (tpktLen == segLen)
{
// This packet contains the last segment, it's ready for reasseble
NextFrameSegmentLength = 0;
LastSegment = true; // The last segment of this frame is the last part of an integreted tpkt packet.
segs.Length = segLen;
TpktSegments.Add(new TpktSegment(segs, true));
}
else // if (tpktLen < segLen)
{
// Contains a integral TPKT and another one or more segment(s) succeed
segs.Length = tpktLen;
TpktSegments.Add(new TpktSegment(segs, true));
BuildSegments(segs.EncapsulatedBytes(), false);
}
}
/// <summary>
/// For a frame with leading segment.
/// </summary>
/// <param name="segs">The segment without the leading segments</param>
private void BuildSegments(ByteArraySegment segs, bool referFileds)
{
HasSegments = true;
TcpPacketType type;
int segLen = segs.Length;
if (referFileds)
{
segs.Length = fileds.LeadingSegmentLength;
TpktSegments.Add(new TpktSegment(this.header.ActualBytes(), false)); // possible some refactoring here
segs = segs.EncapsulatedBytes();
// refresh the length value
segLen = segs.Length; // When succssor's payload has only one segment, it will crash. see X.X.0.115 No.7322, 7325
}
if (segLen > 0)
{
byte[] potentialHeader = segs.ActualBytes().Take(TpktFileds.HeaderLength).ToArray();
type = (TcpPacketType)(BigEndianBitConverter.Big.ToInt16(potentialHeader, 0));
switch (type)
{
case TcpPacketType.Tpkt:
int tpktLen = BigEndianBitConverter.Big.ToInt16(potentialHeader,
TpktFileds.ReservedLength + TpktFileds.VersionLength
);
// refresh the length value
// segs.Length = segLen;
BuildSegments(segs, tpktLen, segLen);
break;
default:
break;
}
}
else
{
LastSegment = true;
}
}
