public Channel(ByteArraySegment bas)
{
bas.Length = valueLength;
value = BigEndianBitConverter.Big.ToInt32(bas.ActualBytes(), 0, true);
quality = new Quality(bas.EncapsulatedBytes(qualityLength));
bas.Length += qualityLength;
}
public TagFiled(ByteArraySegment bas)
{
// set Length not ready
Code = -1;
int len = 1;
bas.Length = len;
byte tag = bas.ActualBytes()[0];
Type = (TagType)(tag & TAG_TYPE_MASK);
IsConstructed = Convert.ToBoolean(tag & CONSTRUCTED_MASK);
Code = tag & TAG_CODE_MASK;
/*
* When Code == TAG_CODE_MASK, the tag is more
* than 1 byte, and the first byte change to a leading
* byte.
*/
if (Code == MAX_SINGLE_OCTET_TAG_CODE)
{
int code = 0;
byte succeedOctet;
bool hasNextOctet = false;
do
{
code <<= 7;
bas.Length++;
succeedOctet = bas.EncapsulatedBytes(bas.Length - 1).ActualBytes()[0];
code |= succeedOctet;
// If the highest bit == 0, it's the last succeed octet
hasNextOctet = Convert.ToBoolean(succeedOctet >> LAST_SUCCEED_OCTET_BIT);
} while (hasNextOctet);
Code = code;
}
bas.Length = this.BytesCount;
RawBytes = bas.ActualBytes();
}
public CotpPacket(ByteArraySegment bas, Packet parent)
{
this.ParentPacket = parent;
header = bas;
header.Length = BigEndianBitConverter.Big.ToInt8(new ByteArraySegment(bas.Bytes, bas.Offset, 1).ActualBytes(), 0) +
CotpFileds.LengthLength;
byte num_eot = header.ActualBytes()[CotpFileds.LengthLength + CotpFileds.PduTypeLength];
this.Type = (TpduType)(BigEndianBitConverter.Big.ToInt8(header.ActualBytes(), 1));
switch (Type)
{
case TpduType.ConnectioinRequest:
break;
case TpduType.ConnectionConfirm:
break;
case TpduType.DataTransfer:
TpduNumber = num_eot & TPDU_NUM_MASK;
LastDataUnit = Convert.ToBoolean(num_eot >> LAST_DU_BIT);
break;
case TpduType.DisconnectionRequest:
break;
case TpduType.ExpectedDataTransfer:
break;
default:
break;
}
var payload = header.EncapsulatedBytes();
payloadPacketOrData = new PacketOrByteArraySegment();
payloadPacketOrData.TheByteArraySegment = payload;
}
/// <summary>
/// For a frame with normal TPKT start and segments appended.
/// </summary>
/// <param name="payload">Actual payload of this frame</param>
/// <param name="length">The length that TPKT header indicate(header itself is exclude)</param>
private void BuildSegments(ByteArraySegment payload, int length)
{
HasSegments = true;
// Let the length of original TKPT payload without segments
// be input param length which indicate the TPKT's payload length.
int segLen = payload.Length - length;
payload.Length = length;
if (segLen > 0)
{
ByteArraySegment segs = payload.EncapsulatedBytes();
// The rest segments may be the next TPKT beginning which includes TPKT header.
// var potentialHeader = segs;// new ByteArraySegment(segs);
//segs.Length = TpktFileds.TpktHeaderLength;
// segs may contain multiple TPKT segments
byte[] headerRawBytes = segs.ActualBytes().Take(TpktFileds.HeaderLength).ToArray();
TcpPacketType type = (TcpPacketType)(BigEndianBitConverter.Big.ToInt16(headerRawBytes, 0));
switch (type)
{
case TcpPacketType.Tpkt:
// LastSegment = false;
int tpktLen = BigEndianBitConverter.Big.ToInt16(headerRawBytes,
TpktFileds.ReservedLength + TpktFileds.VersionLength
);
BuildSegments(segs, tpktLen, segLen);
break;
default:
break;
}
}
else
{
ByteArraySegment segs = new ByteArraySegment(payload.Bytes);
BuildSegments(segs, this.Length, segs.Length);
}
}
/// <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;
}
}
public Quality(ByteArraySegment bas) : this(bas.ActualBytes())
{
}