/// <summary>
/// Serlialize this routing option into something which
/// can be passed to an IpV4Packet class.
/// </summary>
/// <returns>
/// An IpV4Option class which can be passed to an IpV4Packet.
/// </returns>
public IpV4Option Serialize ()
{
IpV4Option newOption = new IpV4Option ();
// fill in basic fields
newOption.Class = IpV4OptionClass.DebuggingAndMeasurement;
newOption.OptionType = IpV4OptionNumber.InternetTimestamp;
newOption.IsCopied = false;
newOption.Length = (m_timestamps.Length * (m_type == IpV4TimestampType.TimestampAndAddress ? 8 : 4)) + 4;
newOption.Data = new byte[newOption.Length - 2];
// first copy in the pointer
newOption.Data[0] = (byte)m_pointer;
// then the overflow and type
newOption.Data[1] = (byte)(m_overflow << 4);
newOption.Data[1] |= (byte)m_type;
// loop through each field and add that
for (int i = 0; i < m_timestamps.Length; i++)
{
if (m_type == IpV4TimestampType.TimestampAndAddress)
{
Array.Copy (m_addressstamps[i].GetAddressBytes (), 0, newOption.Data, (i * 8) + 2, 4);
Array.Copy (BitConverter.GetBytes (m_timestamps[i]), 0, newOption.Data, (i * 8) + 6, 4);
}
else
{
Array.Copy (BitConverter.GetBytes (m_timestamps[i]), 0, newOption.Data, (i * 4) + 2, 4);
}
}
return newOption;
}
/// <summary>
/// Serlialize this routing option into something which
/// can be passed to an IpV4Packet class.
/// </summary>
/// <returns>
/// An IpV4Option class which can be passed to an IpV4Packet.
/// </returns>
public IpV4Option Serialize ()
{
IpV4Option newOption = new IpV4Option ();
// fill in basic fields
newOption.Class = IpV4OptionClass.Control;
newOption.OptionType = IpV4OptionNumber.StreamId;
newOption.IsCopied = true;
newOption.Length = 4;
newOption.Data = new byte[2];
// copy in the stream id
newOption.Data = BitConverter.GetBytes (m_id);
return newOption;
}
/// <summary>
/// Create a new time stamp option.
/// </summary>
/// <param name="option">
/// The option to parse.
/// </param>
/// <exception cref="ArgumentNullException">
/// The option argument is null.
/// </exception>
/// <exception cref="ArgumentException">
/// The option argument is not a timestamp option.
/// </exception>
public IpV4TimeStampOption (IpV4Option option)
{
if (option == null)
{
throw new ArgumentNullException ("option");
}
if (option.OptionType != IpV4OptionNumber.InternetTimestamp)
{
throw new ArgumentException ("The option passed was not compatible with this class. This class accepts timestamp options only", "option");
}
// extract the pointer
m_pointer = (byte)option.Data[0];
// extract the overflow field
m_overflow = (byte)((option.Data[1] & 0xf0) >> 4);
// extract the type
m_type = (IpV4TimestampType)(option.Data[1] & 0xf);
// calculate how many fields there are and allocate space
int numberStamps = (option.Data.Length - 2) / 4;
if (m_type == IpV4TimestampType.TimestampAndAddress)
{
numberStamps /= 2;
m_addressstamps = new IPAddress[numberStamps];
}
m_timestamps = new uint[numberStamps];
// extract the time stamps and addresses
for (int i = 0; i < numberStamps; i++)
{
if (m_type == IpV4TimestampType.TimestampAndAddress)
{
uint address = BitConverter.ToUInt32 (option.Data, (i * 8) + 2);
m_addressstamps[i] = new IPAddress ((long)address);
m_timestamps[i] = BitConverter.ToUInt32 (option.Data, (i * 8) + 6);
}
else
{
m_timestamps[i] = BitConverter.ToUInt32 (option.Data, (i * 4) + 2);
}
}
}
/// <summary>
/// Serlialize this routing option into something which
/// can be passed to an IpV4Packet class.
/// </summary>
/// <param name="optionType">
/// There are 3 types of routing option: loose source, strict source and record.
/// </param>
/// <returns>
/// An IpV4Option class which can be passed to an IpV4Packet.
/// </returns>
/// <exception cref="ArgumentException">
/// The option type is not a routing option.
/// </exception>
public IpV4Option Serialize (IpV4OptionNumber optionType)
{
IpV4Option newOption = new IpV4Option ();
if (optionType != IpV4OptionNumber.LooseSourceRouting &&
optionType != IpV4OptionNumber.StrictSourceRouting &&
optionType != IpV4OptionNumber.RecordRoute)
{
throw new ArgumentException ("The option type must be a routing option (strict source routing, loose source routing or record route", "option");
}
// fill in basic fields
newOption.Class = IpV4OptionClass.Control;
newOption.OptionType = optionType;
newOption.IsCopied = true;
newOption.Length = (m_routeData.Length * 4) + 3;
newOption.Data = new byte[(m_routeData.Length * 4) + 1];
// fill in the pointer
newOption.Data [0] = (byte)m_pointer;
// fill in the route data
for (int i = 0; i < m_routeData.Length; i++)
{
Array.Copy (m_routeData[i].GetAddressBytes (), 0, newOption.Data, (i * 4) + 1, 4);
}
return newOption;
}
/// <summary>
/// Create a new stream identifier option.
/// </summary>
/// <param name="option">
/// The option to parse.
/// </param>
public IpV4StreamIdentifierOption (IpV4Option option)
{
if (option == null)
{
throw new ArgumentNullException ("option");
}
if (option.OptionType != IpV4OptionNumber.StreamId)
{
throw new ArgumentException ("The option passed was not compatible with this class. This class accepts stream id options only", "option");
}
// extract the stream id
m_id = BitConverter.ToUInt16 (option.Data, 0);
}
/// <summary>
/// Create a new routing option.
/// </summary>
/// <param name="option">
/// The option to parse.
/// </param>
/// <exception cref="ArgumentNullException">
/// The option argument is null.
/// </exception>
/// <exception cref="ArgumentException">
/// The option argument is not a routing option.
/// </exception>
public IpV4RoutingOption (IpV4Option option)
{
if (option == null)
{
throw new ArgumentNullException ("option");
}
if (option.OptionType != IpV4OptionNumber.LooseSourceRouting &&
option.OptionType != IpV4OptionNumber.StrictSourceRouting &&
option.OptionType != IpV4OptionNumber.RecordRoute)
{
throw new ArgumentException ("The option passed was not compatible with this class. This class accepts routing options only", "option");
}
// read the pointer
m_pointer = (byte)option.Data[0];
// get the number of addresses in the route
// and allocate enough space
int routeSize = (option.Length - 3) / 4;
m_routeData = new IPAddress[routeSize];
// extract each address from the data
for (int i = 0; i < m_routeData.Length; i++)
{
uint address = BitConverter.ToUInt32 (option.Data, i * 4 + 1);
m_routeData[i] = new IPAddress ((long)address);
}
}
/// <summary>
/// Serlialize this routing option into something which
/// can be passed to an IpV4Packet class.
/// </summary>
/// <returns>
/// An IpV4Option class which can be passed to an IpV4Packet.
/// </returns>
public IpV4Option Serialize ()
{
IpV4Option newOption = new IpV4Option ();
// fill in basic fields
newOption.Class = IpV4OptionClass.Control;
newOption.OptionType = IpV4OptionNumber.Security;
newOption.IsCopied = true;
newOption.Length = 11;
newOption.Data = new byte[9];
// fill in the security bytes
newOption.Data[0] = (byte)((int)m_level & 0x00ff);
newOption.Data[1] = (byte)(((int)m_level & 0xff00) >> 8);
// fill in the compartment bytes
newOption.Data[2] = (byte)(m_compartment & 0x00ff);
newOption.Data[3] = (byte)((m_compartment & 0xff00) >> 8);
// fill in the handling bytes
newOption.Data[4] = (byte)(m_handling & 0x00ff);
newOption.Data[5] = (byte)((m_handling & 0xff00) >> 8);
// fill in the transmission control code bytes
newOption.Data[6] = (byte)((m_tcc & 0xff0000) >> 16);
newOption.Data[7] = (byte)((m_tcc & 0x00ff00) >> 8);
newOption.Data[8] = (byte)(m_tcc & 0x0000ff);
return newOption;
}
/// <summary>
/// Create a new security option.
/// </summary>
/// <param name="option">
/// The option to parse.
/// </param>
/// <exception cref="ArgumentNullException">
/// The option argument is null.
/// </exception>
/// <exception cref="ArgumentException">
/// The option argument is not a security option.
/// </exception>
public IpV4SecurityOption (IpV4Option option)
{
if (option == null)
{
throw new ArgumentNullException ("option");
}
if (option.OptionType != IpV4OptionNumber.Security)
{
throw new ArgumentException ("The option passed was not compatible with this class. This class accepts security options only", "option");
}
// extract the security level field
m_level = (IpV4SecurityLevelType) BitConverter.ToUInt16 (option.Data, 0);
// extract the compartment field
m_compartment = BitConverter.ToUInt16 (option.Data, 2);
// extract the handling restrictions field
m_handling = BitConverter.ToUInt16 (option.Data, 4);
// extract the 24 bits of the transmission control code
m_tcc = (uint)(option.Data[6] << 0x10);
m_tcc |= (uint)(option.Data[7] << 0x08);
m_tcc |= option.Data[8];
}
/// <summary>
/// The fragment method will turn this IP packet into several using fragmentation.
/// </summary>
/// <param name="maximumTransmissionUnit">
/// The maximum size of the data in each fragment. The maximum transmission unit must
/// be a multiple of 8. For example 8, 16, 24, 32 etc.
/// </param>
/// <returns>
/// This method returns an array of fragmented IP packets which can be sent over the
/// network.
/// </returns>
/// <exception cref="ArgumentException">
/// The MTU (maximum Transmission Unit) must be a multiple of 8 bytes
/// </exception>
public IpV4Packet[] Fragment (int maximumTransmissionUnit)
{
if (maximumTransmissionUnit % 8 != 0 && maximumTransmissionUnit > 0)
{
throw new ArgumentException ("The MTU (maximum Transmission Unit) must be a multiple of 8 bytes", "maximumTransmissionUnit");
}
// calculate how many fragments of the maximum transmission unit size we need
int fragmentCount = m_data.Length / maximumTransmissionUnit;
// and if the data doesn't exactly divide up into the maximum transmission unit
// size then add a new fragment for the bit on the end
if (m_data.Length % maximumTransmissionUnit != 0)
{
fragmentCount++;
}
// allocate space for the fragments
IpV4Packet[] fragments = new IpV4Packet[fragmentCount];
// build each fragment
for (int i = 0; i < fragments.Length; i++)
{
fragments[i] = new IpV4Packet ();
fragments[i].SourceAddress = m_sourceAddress;
fragments[i].DestinationAddress = m_destAddress;
fragments[i].Identification = m_id;
fragments[i].HeaderLength = 0x14;
fragments[i].TimeToLive = m_ttl;
fragments[i].TransportProtocol = m_protocol;
fragments[i].TypeOfService = m_tos;
fragments[i].Version = 0x04;
#region Add Options
// if there are options...
if (m_options != null)
{
int optionsLength = 0;
// if this is the first fragment, simply copy in all the options.
if (i == 0)
{
fragments[i].Options = new IpV4Option[m_options.Length];
m_options.CopyTo (fragments[i].Options, 0);
// calculate the size in bytes of the options field
for (int j = 0; j < m_options.Length; j++)
{
optionsLength += m_options[j].Length;
}
}
// if not, copy in the ones which have the copy flag set
else
{
for (int j = 0; j < m_options.Length; j++)
{
if (m_options[j].IsCopied)
{
if (fragments[i].Options == null)
{
fragments[i].Options = new IpV4Option[1];
}
else
{
// add this new option to the array
IpV4Option[] tempOptions = new IpV4Option[fragments[i].Options.Length];
Array.Copy (fragments[i].Options, 0, tempOptions, 0, fragments[i].Options.Length);
fragments[i].Options = new IpV4Option[fragments[i].Options.Length + 1];
Array.Copy (tempOptions, 0, fragments[i].Options, 0, tempOptions.Length);
}
fragments[i].Options[fragments[i].Options.Length - 1] = m_options[j];
// calculate the new size of the options
optionsLength += m_options[j].Length;
}
}
}
fragments[i].HeaderLength += (ushort)optionsLength;
// if we need padding to end the header on a 32 bit boundary
if (optionsLength % 4 != 0)
{
// then add padding!
fragments[i].Padding = new byte[4 - (optionsLength % 4)];
fragments[i].HeaderLength += (ushort)(4 - (optionsLength % 4));
}
}
#endregion
// calculate the offset
fragments[i].ControlFlags.Offset = (ushort)(i * maximumTransmissionUnit);
// set up the control flags
fragments[i].ControlFlags.MoreFragments = (i < fragments.Length - 1);
fragments[i].ControlFlags.DontFragment = false;
// copy the data into the buffer at the correct offset
if ((i < fragments.Length - 1) || m_data.Length % maximumTransmissionUnit == 0)
{
fragments[i].Data = new byte[maximumTransmissionUnit];
Array.Copy (m_data, fragments[i].ControlFlags.Offset, fragments[i].Data, 0, maximumTransmissionUnit);
}
else
{
fragments[i].Data = new byte[m_data.Length % maximumTransmissionUnit];
Array.Copy (m_data, fragments[i].ControlFlags.Offset, fragments[i].Data, 0, m_data.Length % maximumTransmissionUnit);
}
// and finally the total size
fragments[i].TotalLength = (ushort)(fragments[i].HeaderLength + fragments[i].Data.Length);
}
return fragments;
}
/// <summary>
/// Create a new IPv4 packet.
/// </summary>
/// <param name="data">
/// The byte array representing the IP packet.
/// </param>
public IpV4Packet (byte[] data)
{
int position = 0;
#region Basic Fields
// extract the version field from the first 4 bits of the packet
m_version = Convert.ToByte ((data[position] >> 4));
// extract the header length field from the next 4 bits. This is the number
// of 32 bit words so multiply by 4 to get the number of 8 bit words..i.e..bytes
m_headerLength = Convert.ToByte ((data[position] & 0x0f) * 4);
position++;
// extract the precedence from the next 3 bits
m_tos.Precedence = (IpV4PrecedenceType) (data[position] >> 5);
// then extract the delay, throughput and reliability bits
m_tos.Delay = (IpV4DelayType) ((data[position] & 0x10) >> 4);
m_tos.Throughput = (IpV4ThroughputType) ((data[position] & 0x8) >> 3);
m_tos.Reliability = (IpV4ReliabilityType) ((data[position] & 0x4) >> 2);
position++;
// get the total length (remembering to convert it to host order)
m_totalLength = (ushort)(IPAddress.NetworkToHostOrder (BitConverter.ToInt16 (data, position)));
position += 2;
// same with the identification field
m_id = (ushort)(IPAddress.NetworkToHostOrder (BitConverter.ToInt16 (data, position)));
position += 2;
// extract the internet control flags
m_icf.DontFragment = ((data[position] & 0x40) >> 6) == 1;
m_icf.MoreFragments = ((data[position] & 0x20) >> 5) == 1;
// and the fragmentation offsent (remember to convert to host order)
m_icf.Offset = (ushort)(IPAddress.NetworkToHostOrder ((Convert.ToInt16 (BitConverter.ToInt16 (data, position) & 0x1fff))) * 8);
position += 2;
// the time to live is just in a single byte
m_ttl = data[position];
position++;
// as is the protocol
m_protocol = (ProtocolType)(data[position]);
position++;
// the checksum
m_checksum = (ushort)(IPAddress.NetworkToHostOrder (BitConverter.ToInt16 (data, position)));
position += 2;
// now copy in the source address
m_sourceAddress = new IPAddress (BitConverter.ToUInt32 (data, position));
position += 4;
// and the destination address
m_destAddress = new IPAddress (BitConverter.ToUInt32 (data, position));
position += 4;
#endregion
#region Options and Padding
// check if there are any options (if the header length is greater than the
// smallest, 0x14 bytes)
if (m_headerLength > 0x14)
{
// create a new buffer of the correct size and copy the options into it
byte[] optionsAndPadding = new byte[m_headerLength - 0x14];
Array.Copy (data, position, optionsAndPadding, 0, optionsAndPadding.Length);
// go through each byte of the options
for (int i = 0; i < optionsAndPadding.Length;)
{
IpV4Option option = new IpV4Option ();
// fill in basic fields
option.OptionType = (IpV4OptionNumber)optionsAndPadding[i];
i++;
#region Fill in Basic Option Fields
if (option.OptionType == IpV4OptionNumber.EndOfOptions)
{
// copy the padding field out of the header
if (optionsAndPadding.Length - i > 0)
{
m_padding = new byte[optionsAndPadding.Length - i];
Array.Copy (optionsAndPadding, i, m_padding, 0, m_padding.Length);
}
// add this option to the array
option.Length = 1;
}
else if (option.OptionType != IpV4OptionNumber.NoOperation)
{
// copy out the length field
option.Length = (int)(optionsAndPadding[i]);
option.Data = new byte[option.Length - 2];
// copy the actual data out of the packet
i++;
Array.Copy (optionsAndPadding, i, option.Data, 0, option.Data.Length);
// add this new option to the array
i += option.Data.Length;
}
else
{
option.Length = 1;
}
#endregion
#region Add Option
if (m_options == null)
{
m_options = new IpV4Option[1];
}
else
{
IpV4Option[] tempOptions = new IpV4Option[m_options.Length];
Array.Copy (m_options, 0, tempOptions, 0, m_options.Length);
m_options = new IpV4Option[m_options.Length + 1];
Array.Copy (tempOptions, 0, m_options, 0, tempOptions.Length);
m_options[m_options.Length - 1] = option;
}
m_options[m_options.Length - 1] = option;
#endregion
if (option.OptionType == IpV4OptionNumber.EndOfOptions)
{
break;
}
}
position += optionsAndPadding.Length;
}
#endregion
// now check if there is any data (which there should be)
if (data.Length > m_headerLength)
{
// allocate a new buffer for it and copy the data in to the buffer
m_data = new byte[data.Length - m_headerLength];
Array.Copy (data, position, m_data, 0, m_data.Length);
}
}