private byte[] GetHeaderBytes()
{
//TODO - the following things don't work (because of endianism)
// Identification + Flags + Fragment Offset
// Header Checksum
List <byte> bytes = new List <byte>();
List <UInt32> fields = new List <UInt32>();
//Add the packetsections together into 32-bit words
//UInt32 field1 = 0;
UInt32 xVersion = (UInt32)(this.Version << 28);
UInt32 xHeaderLength = (UInt32)(this.HeaderLength << 24);
UInt32 xTypeOfService = (UInt32)(this.TypeOfService << 16);
UInt32 xTotalLength = (UInt32)(this.TotalLength << 0);
//field1 = ;
fields.Add(HostToNetwork(xVersion + xHeaderLength + xTypeOfService + xTotalLength));
//UInt32 field2 = (UInt32)((this.Identification << 16) | ((byte)(this.FragmentFlags)) << 12 | (this.FragmentOffset << 1));
UInt32 field2 = 0;
UInt32 Identity = (UInt32)(this.Identification << 16);
UInt32 Flags = (UInt32)((byte)(this.FragmentFlags)) << 14;
UInt32 Offset = (UInt32)((this.FragmentOffset) & (UInt16)0xFF);
field2 = Identity + Flags + Offset;
fields.Add(HostToNetwork(field2));
//UInt32 field3 = (UInt32)((this.TimeToLive << 0) | (((byte)(this.Protocol)) << 8) | (UInt16)(this.HeaderChecksum << 16));
UInt32 xTimeToLive = (UInt32)(this.TimeToLive << 24);
UInt32 xProtocol = (UInt32)((byte)this.Protocol << 16);
UInt32 xHeaderChecksum = (UInt32)(this.HeaderChecksum << 0);
//Console.WriteLine("Field3: " + field3.ToBinary(32));
fields.Add(HostToNetwork(xTimeToLive + xProtocol + xHeaderChecksum));
//Split the 32-bit words into bytes
for (int i = 0; i < fields.Count; i++)
{
bytes.Add((byte)(fields[i] >> 0));
bytes.Add((byte)(fields[i] >> 8));
bytes.Add((byte)(fields[i] >> 16));
bytes.Add((byte)(fields[i] >> 24));
}
//Source and Destination
foreach (byte b in SourceAddress.ToByteArray())
{
bytes.Add(b);
}
foreach (byte b in DestinationAddress.ToByteArray())
{
bytes.Add(b);
}
//TODO - Options field
return(bytes.ToArray());
}