/// <summary>
/// Send a new ping packet.
/// </summary>
/// <param name="destination">
/// The address to send the packet to.
/// </param>
/// <param name="payload">
/// The data to send in the ping.
/// </param>
/// <param name="async">
/// If this is true, SendPing will return immediately otherwise it will wait
/// </param>
/// <param name="timeOutTime">
/// The number of milliseconds before the reply times out.
/// </param>
/// <exception cref="ObjectDisposedException">
/// If the class has been disposed then an ObjectDisposedException will be thrown.
/// </exception>
/// <exception cref="Exception">
/// If the class is already waiting for a ping reply then an exception will be thrown.
/// Use the CancelPing method first.
/// </exception>
public void SendPing(IPAddress destination, byte[] payload, bool async, double timeOutTime)
{
if (m_disposed)
{
throw new ObjectDisposedException(this.ToString(), "This object has already been disposed");
}
// check if a ping is already in process
if (m_id != 0)
{
throw new Exception("A ping request is already in process. Either wait for the reply, or cancel the request first");
}
Random random = new Random();
IcmpEcho echo = new IcmpEcho();
// generate random identifier and sequence number
echo.Identifier = (ushort)random.Next(ushort.MaxValue);
echo.SequenceNumber = (ushort)random.Next(ushort.MaxValue);
m_id = echo.Identifier;
m_remoteAddress = destination;
m_timer.Interval = timeOutTime;
// store the payload
echo.Data = payload;
// build the icmp header
IcmpPacket icmpHeader = echo.Serialize(false);
// build the ip header
IpV4Packet ipHeader = new IpV4Packet();
ipHeader.TransportProtocol = ProtocolType.Icmp;
ipHeader.SourceAddress = m_networkInterface;
ipHeader.DestinationAddress = destination;
ipHeader.Data = icmpHeader.Serialize();
if (m_fragment)
{
IpV4Packet[] fragments = ipHeader.Fragment(8);
// send each fragment
for (int i = 0; i < fragments.Length; i++)
{
byte[] packet = fragments[i].Serialize();
m_socket.SendTo(packet, 0, packet.Length, SocketFlags.None, new IPEndPoint(fragments[i].DestinationAddress, 0));
}
}
else
{
// send the packet
byte[] packet = ipHeader.Serialize();
m_socket.SendTo(packet, 0, packet.Length, SocketFlags.None, new IPEndPoint(ipHeader.DestinationAddress, 0));
}
// save the time and start the timeout timer
m_start = Environment.TickCount;
m_timer.Enabled = true;
// wait for the reply
m_waitObject.Reset();
if (!async)
{
m_waitObject.WaitOne();
}
}
/// <summary>
/// Send the next request in order to find the next hop.
/// </summary>
private void SendRequest()
{
// generate a 32 byte payload
string data = new string ('x', 32);
byte[] payload = System.Text.ASCIIEncoding.ASCII.GetBytes(data);
// fill in ip header fields
IpV4Packet ipPacket = new IpV4Packet();
ipPacket.DestinationAddress = m_remoteAddress;
ipPacket.SourceAddress = m_localAddress;
ipPacket.TransportProtocol = ProtocolType.Icmp;
ipPacket.TimeToLive = m_ttl;
// save the identification
m_ipId = ipPacket.Identification;
// add routing options if any
if (m_route != null)
{
ipPacket.Options = new IpV4Option[2];
ipPacket.Options[0] = m_route.Serialize(m_strictRouting ? IpV4OptionNumber.StrictSourceRouting : IpV4OptionNumber.LooseSourceRouting);
ipPacket.Options[1] = new IpV4Option();
ipPacket.Options[1].OptionType = IpV4OptionNumber.EndOfOptions;
ipPacket.Options[1].IsCopied = false;
ipPacket.Options[1].Length = 1;
ipPacket.Options[1].Class = IpV4OptionClass.Control;
ipPacket.Options[1].Data = null;
}
// create a new echo packet
IcmpEcho echo = new IcmpEcho();
echo.Identifier = m_id;
echo.Data = payload;
// serialize the icmp packet
IcmpPacket icmpPacket = echo.Serialize(false);
ipPacket.Data = icmpPacket.Serialize();
if (m_fragment)
{
IpV4Packet[] fragments = ipPacket.Fragment(8);
// send each fragment
for (int i = 0; i < fragments.Length; i++)
{
byte[] packet = fragments[i].Serialize();
m_socket.SendTo(packet, 0, packet.Length, SocketFlags.None, new IPEndPoint(fragments[i].DestinationAddress, 0));
}
}
else
{
// send the ip packet
byte[] packet = ipPacket.Serialize();
m_socket.SendTo(packet, 0, packet.Length, SocketFlags.None, new IPEndPoint(ipPacket.DestinationAddress, 0));
}
// grab the current time
m_start = Environment.TickCount;
// start the timeout timer
m_timer.Enabled = true;
}