/// <summary>
/// Processes a received packet for a UDP request using the identification field.
/// </summary>
/// <param name="ip">The IP packet.</param>
/// <param name="length">The data length.</param>
/// <param name="result">The result.</param>
private void ProcessPacketUdpIdentification(ProtoPacketIp ip, int length, MultipathTracerouteResult result)
{
ProtoPacketIcmp icmp;
// If the packet payload is ICMP.
if ((icmp = ip.Payload as ProtoPacketIcmp) != null)
{
if (icmp.Type == (byte)ProtoPacketIcmp.IcmpType.TimeExceeded)
{
// If the packet type is ICMP time exceeded.
ProtoPacketIcmpTimeExceeded icmpTimeExceeded = icmp as ProtoPacketIcmpTimeExceeded;
// Use the last bytes of the UDP ports to find the flow.
ushort flowId = (ushort)((icmpTimeExceeded.IpPayload[1] << 8) | icmpTimeExceeded.IpPayload[3]);
byte flow;
if (result.TryGetUdpFlow(flowId, out flow))
{
// Get the time-to-live.
byte ttl = (byte)(icmpTimeExceeded.IpHeader.Identification >> 8);
// Get the attempt.
byte attempt = (byte)(icmpTimeExceeded.IpHeader.Identification & 0xF);
// Add the result.
result.UdpDataResponseReceived(flow, ttl, attempt, MultipathTracerouteData.ResponseType.TimeExceeded, DateTime.Now, ip);
// Remove the corresponding request.
result.RemoveRequest(MultipathTracerouteResult.RequestType.Udp, flow, ttl, attempt);
}
}
else if (icmp.Type == (byte)ProtoPacketIcmp.IcmpType.DestinationUnreachable)
{
// If the packet type is ICMP destination unreachable.
ProtoPacketIcmpDestinationUnreachable icmpDestinationUnreachable = icmp as ProtoPacketIcmpDestinationUnreachable;
// Check the message is a port unreachable.
if (icmpDestinationUnreachable.Code == (byte)ProtoPacketIcmpDestinationUnreachable.DestinationUnreachableCode.PortUnreachable)
{
// Use the last bytes of the UDP ports to find the flow.
ushort flowId = (ushort)((icmpDestinationUnreachable.IpPayload[1] << 8) | icmpDestinationUnreachable.IpPayload[3]);
byte flow;
if (result.TryGetUdpFlow(flowId, out flow))
{
// Get the time-to-live.
byte ttl = (byte)(icmpDestinationUnreachable.IpHeader.Identification >> 8);
// Get the attempt.
byte attempt = (byte)(icmpDestinationUnreachable.IpHeader.Identification & 0xF);
// Add the result.
result.UdpDataResponseReceived(flow, ttl, attempt, MultipathTracerouteData.ResponseType.DestinationUnreachable, DateTime.Now, ip);
// Remove the corresponding request.
result.RemoveRequest(MultipathTracerouteResult.RequestType.Udp, flow, ttl, attempt);
}
}
}
}
}
///// <summary>
///// Processes a received packet.
///// </summary>
///// <param name="buffer">The data buffer.</param>
///// <param name="length">The data length.</param>
///// <param name="result">The result.</param>
//private void ProcessPacket(byte[] buffer, int length, MultipathTracerouteResult result)
//{
// // Set the buffer index.
// int index = 0;
// // The packets.
// ProtoPacketIp ip;
// // Try and parse the packet using the specified filter.
// if (ProtoPacketIp.ParseFilter(buffer, ref index, length, result.PacketFilters, out ip))
// {
// // Call the callback methods.
// result.Callback(MultipathTracerouteState.StateType.PacketCapture, ip);
// // Process the packet for the current protocol.
// lock (this.syncProcess)
// {
// if (null != this.processPacket) this.processPacket(ip, length, result);
// }
// }
//}
/// <summary>
/// Processes a received packet for an ICMP request.
/// </summary>
/// <param name="ip">The IP packet.</param>
/// <param name="length">The data length.</param>
/// <param name="result">The result.</param>
private void ProcessPacketIcmp(ProtoPacketIp ip, int length, MultipathTracerouteResult result)
{
ProtoPacketIcmp icmp;
// If the packet payload is ICMP.
if ((icmp = ip.Payload as ProtoPacketIcmp) != null)
{
if (icmp.Type == (byte)ProtoPacketIcmp.IcmpType.EchoReply)
{
// If the packet type is ICMP echo reply.
ProtoPacketIcmpEchoReply icmpEchoReply = icmp as ProtoPacketIcmpEchoReply;
// Use the reply identifier to find the flow.
byte flow;
if (result.TryGetIcmpFlow(icmpEchoReply.Identifier, out flow))
{
// Get the time-to-live.
byte ttl = (byte)(icmpEchoReply.Sequence >> 8);
// Get the attempt.
byte attempt = (byte)(icmpEchoReply.Sequence & 0xFF);
// Add the result.
result.IcmpDataResponseReceived(flow, ttl, attempt, MultipathTracerouteData.ResponseType.EchoReply, DateTime.Now, ip);
// Remove the corresponding request.
result.RemoveRequest(MultipathTracerouteResult.RequestType.Icmp, flow, ttl, attempt);
}
}
else if (icmp.Type == (byte)ProtoPacketIcmp.IcmpType.TimeExceeded)
{
// If the packet type is ICMP time exceeded.
ProtoPacketIcmpTimeExceeded icmpTimeExceeded = icmp as ProtoPacketIcmpTimeExceeded;
// Use the ICMP request identifier to find the flow.
ushort flowId = (ushort)((icmpTimeExceeded.IpPayload[4] << 8) | icmpTimeExceeded.IpPayload[5]);
byte flow;
if (result.TryGetIcmpFlow(flowId, out flow))
{
// Get the time-to-live.
byte ttl = icmpTimeExceeded.IpPayload[6];
// Get the attempt.
byte attempt = icmpTimeExceeded.IpPayload[7];
// Add the result.
result.IcmpDataResponseReceived(flow, ttl, attempt, MultipathTracerouteData.ResponseType.TimeExceeded, DateTime.Now, ip);
// Remove the corresponding request.
result.RemoveRequest(MultipathTracerouteResult.RequestType.Icmp, flow, ttl, attempt);
}
}
}
}
