C# PCAP.NET how to send a valid TCP request?

问题:

I wil try using PCAP.NET to send TCP Request from my computer to my server but i don't see request into the server?

Send from my PC and showing in Wireshare here

But can't see this TCP Request on my server, please help.

here is my code

using System;
using System.Collections.Generic;
using PcapDotNet.Base;
using PcapDotNet.Core;
using PcapDotNet.Packets;
using PcapDotNet.Packets.Arp;
using PcapDotNet.Packets.Dns;
using PcapDotNet.Packets.Ethernet;
using PcapDotNet.Packets.Gre;
using PcapDotNet.Packets.Http;
using PcapDotNet.Packets.Icmp;
using PcapDotNet.Packets.Igmp;
using PcapDotNet.Packets.IpV4;
using PcapDotNet.Packets.Transport;
using System.Text;

namespace PcapTest
{
    class Program
    {
        static void Main(string[] args)
        {
            // Retrieve the device list from the local machine
            IList<LivePacketDevice> allDevices = LivePacketDevice.AllLocalMachine;

            if (allDevices.Count == 0)
            {
                Console.WriteLine("No interfaces found! Make sure WinPcap is installed.");
                return;
            }

            // Print the list
            for (int i = 0; i != allDevices.Count; ++i)
            {
                LivePacketDevice device = allDevices[i];
                Console.Write(String.Format("{0}. {1}", (i + 1), device.Name));
                if (device.Description != null)
                    Console.WriteLine(String.Format(" ({0})", device.Description));
                else
                    Console.WriteLine(" (No description available)");
            }

            int deviceIndex = 0;
            do
            {
                Console.WriteLine(String.Format("Enter the interface number (1-{0}):", allDevices.Count));
                string deviceIndexString = Console.ReadLine();
                if (!int.TryParse(deviceIndexString, out deviceIndex) ||
                    deviceIndex < 1 || deviceIndex > allDevices.Count)
                {
                    deviceIndex = 0;
                }
            } while (deviceIndex == 0);

            // Take the selected adapter
            PacketDevice selectedDevice = allDevices[deviceIndex - 1];

            // Open the output device
            using (PacketCommunicator communicator = selectedDevice.Open())
            {
                communicator.SendPacket(BuildTcpPacket());
            }
            Console.ReadKey();
        }

        private static Packet BuildTcpPacket()
        {
            EthernetLayer ethernetLayer =
                new EthernetLayer
                {
                    Source = new MacAddress("00:25:22:50:ef:74"),
                    Destination = new MacAddress("02:02:02:02:02:02"),
                    EtherType = EthernetType.None, // Will be filled automatically.
                };

            IpV4Layer ipV4Layer =
                new IpV4Layer
                {
                    Source = new IpV4Address("192.168.1.203"), // <- this is my LAN IP ADDRESS IS TRUE??
                    CurrentDestination = new IpV4Address("113.23.x.x"), // <-- THIS IS MY SERVER IPADDESS??
                    Fragmentation = IpV4Fragmentation.None,
                    HeaderChecksum = null, // Will be filled automatically.
                    Identification = 64,
                    Options = IpV4Options.None,
                    Protocol = null, // Will be filled automatically.
                    Ttl = 64,
                    TypeOfService = 0,
                };

            TcpLayer tcpLayer =
                new TcpLayer
                {
                    SourcePort = 9509,
                    DestinationPort = 80,
                    Checksum = null, // Will be filled automatically.
                    SequenceNumber = 100,
                    AcknowledgmentNumber = 50,
                    ControlBits = TcpControlBits.Acknowledgment,
                    Window = 100,
                    UrgentPointer = 0,
                    Options = TcpOptions.None,
                };

            PayloadLayer payloadLayer =
                new PayloadLayer
                {
                    Data = new Datagram(Encoding.ASCII.GetBytes("hello world")),
                };

            PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, tcpLayer);

            return builder.Build(DateTime.Now);
        }
    }
}

回答1:

I can't see that you are using your payloadLayer in the PacketBuilder.

According to a sample from Pcat.net, the payload should be included in the PacketBuilder constructor.

PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, tcpLayer, payloadLayer);

Tutorial sending packets