C#实现抓包，并过滤UDP

C#实现抓包，并过滤UDP

using PacketDotNet;
using SharpPcap;
using SharpPcap.LibPcap;
using System;
using System.Linq;
using System.Net.Sockets;
using System.Text;

namespace ConsoleAppSharppcap
{
    internal class Program
    {
        static void Main(string[] args)
        {

            LibPcapLiveDeviceList devices = LibPcapLiveDeviceList.Instance;

            string ToHex(byte[] data)
            {
                return BitConverter.ToString(data).Replace("-", string.Empty);
            }

            string GetRoomNumber(byte[] data)
            {
                return data[26].ToString() + data[27].ToString("D2");
            }
            bool IsSOS(byte[] data)
            {
                return (data[72] == 1);
            }

            void auto_msg_5e00(byte[] data)
            {
                if (ToHex(data.Take(2).ToArray()) != "5E00")
                {
                    return;
                }
                //bool bIsSOS = IsSOS(data);
                if (true)
                {
                    Console.WriteLine("{0},{1}", GetRoomNumber(data), data[72]);
                }
                Response.DataContractData rdata = new Response.DataContractData();
                rdata.Id = GetRoomNumber(data);
                rdata.IsSOS = data[72];
                byte[] data2 = Encoding.UTF8.GetBytes(JSON.Stringify(rdata));
                UdpClient udpClient = new UdpClient();
                udpClient.Send(data2, data2.Length, "172.19.19.0", 12388);
            }

            void Device_OnPacketArrival(object s, PacketCapture e)
            {
                RawCapture ePacket = e.GetPacket();
                Packet packet = Packet.ParsePacket(ePacket.LinkLayerType, ePacket.Data);
                if (packet is EthernetPacket ethernetPacket)
                {
                    if (ethernetPacket.PayloadPacket is IPPacket ipPacket)
                    {
                        //Console.WriteLine($"From {ipPacket.SourceAddress} To {ipPacket.DestinationAddress}");
                        if (ipPacket.PayloadPacket is UdpPacket udpPacket)
                        {
                            if (udpPacket.DestinationPort == 2388)
                            {
                                auto_msg_5e00(udpPacket.PayloadData);
                                return;
                                Console.WriteLine($"From {ipPacket.SourceAddress}:{udpPacket.SourcePort} To {ipPacket.DestinationAddress}:{udpPacket.DestinationPort}");
                                Console.WriteLine($"Packet Length: {udpPacket.PayloadData.Length} bytes");
                                Console.WriteLine();
                            }
                        }
                    }
                }
            }

            foreach (LibPcapLiveDevice device in devices)
            {
                device.Open();
                device.OnPacketArrival += Device_OnPacketArrival;
                device.StartCapture();
            }


            Console.ReadLine();
        }
    }
}