c#如何拦截其他exe网络通讯数据包?
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windows下拦截网络数据封包的方法有四种:
第一种是将网卡设为混杂模式,这次就可以监视到局域网上所有的数据包,
第二种是HOOK目标进程的发送和接收的API函数,
第三种方法是自己实现一个代理的DLL
第四种方法是使用别人封装好的dll,直接调用
我们今天说说第四种方法,我们使用SharpPcap.dll来拦截数据包。
SharpPcap 是一个.NET 环境下的网络包捕获框架,基于著名的 pcap/WinPcap 库开发。提供了捕获、注入、分析和构建的功能,适用于 C# 和 VB NET 开发语言。 SharpPcap有两部分组成:1> SharpPcap.dll 负责数据的捕获 2> PacketDotNet.dll负责数据包的解析
github地址:https://github.com/dotpcap/sharppcap SharpPcap核心代码:
/// <summary> /// 开始捕捉 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnStart_Click(object sender, EventArgs e) { if (this.combDevice.SelectedIndex > -1) { StartCapture(this.combDevice.SelectedIndex); this.btnStart.Enabled = false; this.btnStop.Enabled = true; } else { MessageBox.Show(this,"请选择一个设备","提示",MessageBoxButtons.OK); } } /// <summary> /// 停止捕捉 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void btnStop_Click(object sender, EventArgs e) { Shutdown(); this.btnStop.Enabled = false; this.btnStart.Enabled = true; } private void StartCapture(int itemIndex) { packetCount = 0; device = CaptureDeviceList.Instance[itemIndex]; packetStrings = new Queue<PacketWrapper>(); bs = new BindingSource(); dgvData.DataSource = bs; LastStatisticsOutput = DateTime.Now; // start the background thread backgroundThreadStop = false; backgroundThread = new Thread(BackgroundThread); backgroundThread.Start(); // setup background capture device.OnPacketArrival += new PacketArrivalEventHandler(device_OnPacketArrival); device.OnCaptureStopped += new CaptureStoppedEventHandler(device_OnCaptureStopped); device.Open(); // tcpdump filter to capture only TCP/IP packets string filter = "ip and tcp"; device.Filter = filter; // force an initial statistics update captureStatistics = device.Statistics; UpdateCaptureStatistics(); // start the background capture device.StartCapture(); btnStop.Enabled = true; } /// <summary> /// 设备接收事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void device_OnPacketArrival(object sender, CaptureEventArgs e) { // print out periodic statistics about this device var Now = DateTime.Now; var interval = Now - LastStatisticsOutput; if (interval > new TimeSpan(0, 0, 2)) { Console.WriteLine("device_OnPacketArrival: " + e.Device.Statistics); captureStatistics = e.Device.Statistics; statisticsUiNeedsUpdate = true; LastStatisticsOutput = Now; } lock (QueueLock) { PacketQueue.Add(e.Packet); } } /// <summary> /// 设备停止事件 /// </summary> /// <param name="sender"></param> /// <param name="status"></param> private void device_OnCaptureStopped(object sender, CaptureStoppedEventStatus status) { if (status != CaptureStoppedEventStatus.CompletedWithoutError) { MessageBox.Show("Error stopping capture", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); } } private void UpdateCaptureStatistics() { tlblStatistic.Text = string.Format("接收包: {0}, 丢弃包: {1}, 接口丢弃包: {2}", captureStatistics.ReceivedPackets,captureStatistics.DroppedPackets, captureStatistics.InterfaceDroppedPackets); }