RIP BASED SOFTWARE ROUTER FOR WINDOWS

Question

Good day everyone,

I am working on a project and I am having a few issues.

Project detail

1. Am trying to simulate a RIP based router in Windows

2. I am developing this in C#

3. Am using Winpcap and SharpCap

4. So far I have figured out what my routing table would look like

My issues are as follows

1. Initially when RIP starts it sends a request packet out all RIP enabled interfaces

on IP address 255.255.255.255

I have tried to simulate this directly but decided to let .NET manage the packet 

header creation, so what i have done is simply to send "Type 1 message" as 

the payload and when the receiving router sees this it knows it should send its routes.

This is not how it should be done, but i guess i can work with this for now, as I can't

seem to be able to create my own packet header in C# easily.

Any suggestions on how best I can create a packet without doing low level stuffs would be

appreciated or any library i can simply reference that just accepts port number, ip addresses, 

payload and returns a packet as response?

2. After sending I should wait for response from other Routers.

These received packets are called Response Packets and contain the responding routers'

routes.

To do this i have decided that after the Request is sent out all interfaces, I would wait for about

25sec for responses. 

Issue: I do not know how best to implement this, I have tried editting the Sample Codes in sharpCap

and also tried socket.listen method

but I can't tell if anything is coming in or not.

3. I installed WireShark to help me detect if I am even sending anything out the interfaces in the first place

and it appears am not, as wireshark does not report anything. And yes I selected the right interface.

So any help please.

Below is a cut out of my code so far

...

ArrayList ripIntefaces;

public void start(int[] deviceIndex)

        {

            //get list of intefaces again

            var devices = LivePcapDeviceList.Instance;

            //send request out all RIP enabled interfaces

            for (int k = 0; k < deviceIndex.Length; k++)

                sendRequestsInitial(devices[deviceIndex[k]]);

            //wait 4 response

            while (true)

            {

                //1st time around dont run infinitively, just capture n close

                for (int k = 0; k < deviceIndex.Length; k++)

                    receiveResponse(ripIntefaces, deviceIndex);     //this should be threaded 4 listening on each interface

            }

        }

....

  private void sendRequestsInitial(LivePcapDevice enabledIntf)

        {

            string nxtHop = enabledIntf.Addresses[1].Addr.ipAddress.ToString(); //should be but I cant bind ip add "255.255.255.255"; 

            int portNo = 520;

            Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

            sock.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);

            IPAddress sendTo = IPAddress.Parse(nxtHop);

            IPEndPoint sEndPoint = new IPEndPoint(sendTo, portNo);

            EndPoint sendEndPoint = (EndPoint)sEndPoint;

            sock.Bind(sendEndPoint);

            //create packet to send

            byte[] pktContent = packetProcessor.makeRequestPacket();

                        

            sock.SendTo(pktContent,sendEndPoint);

        }

....

 private void receiveResponse(ArrayList ripNetworks, int[] deviceIndex)

        {

            //monitor all ripInterfaces

            //start new thread 4 each - WORK ON

            var devices = LivePcapDeviceList.Instance;

            LivePcapDevice device = devices[deviceIndex[0]];    //testing 4 1 device 1st, others with thread

            device.OnPacketArrival += new PacketArrivalEventHandler(device_OnPacketArrival);

            int readTimeoutMilliseconds = 25000;

            device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);

            device.StartCapture();

            //device.Close();

            

        } 

...

  private static void device_OnPacketArrival(object sender, CaptureEventArgs e)

        {

        //    myPacket tempPacket = new myPacket();

            var packet = PacketDotNet.Packet.ParsePacket(e.Packet);

            var ip = PacketDotNet.IpPacket.GetEncapsulated(packet);

            var udp = PacketDotNet.UdpPacket.GetEncapsulated(packet);

            string result = string.Empty;

                if(ip != null)

                    {          

                        if (udp != null)

                        {

                            result = Encoding.UTF8.GetString(udp.PayloadData);         

                        }

                }

                Console.WriteLine(result);

        }

....................

class packetProcessor

    {

        static byte[] packet;

        public static byte[] makeRequestPacket()

        {

            string content = "Type 1 Message, Request";

            packet = Encoding.ASCII.GetBytes(content);

            return packet;

        }

    }

So any inputs??