C#如何實現(xiàn)抓包

// 獲取連接列表
CaptureDeviceList devices = CaptureDeviceList.Instance;

// 無連接
if (devices.Count < 1)
{
  Console.WriteLine("No devices were found on this machine");
  return;
}

Console.WriteLine("\n以下為本機連接：");
Console.WriteLine("--------------\n");

int j=0;
string temp = "";
Regex r = new Regex("FriendlyName: .*\n"); //匹配連接的FriendlyName
Match m;
// 打印連接設(shè)備
foreach (ICaptureDevice dev in devices)
{
  temp = dev.ToString();
  m = r.Match(temp);
  Console.WriteLine("{0}：{1}\n", j++, m.ToString());
}
Console.Write("輸入設(shè)備號");
string input = Console.ReadLine();
int i = 0;
try
{
  i = Int32.Parse(input);
}
catch (Exception e)
{
  Console.WriteLine("非法輸入！"+e.Message);
  return;
}
if (devices.Count < 1 || i == -1)
{
  Console.WriteLine("變量非法！");
  return;
}
// 得到指定連接設(shè)備
ICaptureDevice device = devices[i];

// 定義“包到達”事件
device.OnPacketArrival +=new SharpPcap.PacketArrivalEventHandler(device_OnPacketArrival);

// 打開連接
int readTimeoutMilliseconds = 1000;
device.Open(DeviceMode.Promiscuous, readTimeoutMilliseconds);

// 設(shè)置僅獲取目標(biāo)端口為1234的tcp包
string filter = "tcp dst port 1234";
device.Filter = filter;

// 開始無限期捕獲包
device.Capture();

private static void device_OnPacketArrival(object sender, CaptureEventArgs e)
{
  //獲取以太網(wǎng)（Ethernet）的幀
  var ent = PacketDotNet.EthernetPacket.ParsePacket(LinkLayers.Ethernet, e.Packet.Data);
  //獲取ip包
  var ip = ent.PayloadPacket;
  //獲取tcp包
  var tcp = ip.PayloadPacket;
  //格式化tcp包，可直接讀取tcp包中的相應(yīng)值
  var tcp_packet = new TcpPacket(new ByteArraySegment(tcp.Bytes));
  if (tcp != null)
  {
    DateTime time = e.Packet.Timeval.Date;
    if (tcp.PayloadData != null)
    {
      //根據(jù)需要，獲取tcp的data數(shù)據(jù)
      string str = BitConverter.ToString(tcp.PayloadData);
      /*
      *
      其他數(shù)據(jù)處理
      *
      */
    }
  }
}