public TCPHeader(ByteBuffer buffer)
{
this.sourcePort = BitUtils.GetUnsignedShort(buffer.Short);
this.destinationPort = BitUtils.GetUnsignedShort(buffer.Short);
this.sequenceNumber = BitUtils.GetUnsignedInt(buffer.Int);
this.acknowledgementNumber = BitUtils.GetUnsignedInt(buffer.Int);
this.dataOffsetAndReserved = (byte)buffer.Get();
this.headerLength = (this.dataOffsetAndReserved & 0xF0) >> 2;
this.flags = (byte)buffer.Get();
this.window = BitUtils.GetUnsignedShort(buffer.Short);
this.checksum = BitUtils.GetUnsignedShort(buffer.Short);
this.urgentPointer = BitUtils.GetUnsignedShort(buffer.Short);
int optionsLength = this.headerLength - TCP_HEADER_SIZE;
if (optionsLength > 0)
{
optionsAndPadding = new byte[optionsLength];
buffer.Get(optionsAndPadding, 0, optionsLength);
}
}