多线程端口扫描

最新推荐文章于 2021-05-01 07:55:31 发布

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最新推荐文章于 2021-05-01 07:55:31 发布

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分类专栏： .Net 文章标签：多线程 thread string null action network

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本文介绍了一种使用多线程技术进行端口扫描的方法，并针对初始代码存在的问题进行了优化改进，包括解决重复扫描的问题及提高扫描速度。

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今天在论坛发了一个帖子：【200分】多线程问题

最后我把代码封装了一下：

public class PortScan { public static void ScanOpenedPorts(int count, string host, int start, int end, Action<int> portReady, Action completed) { Thread[] threads = new Thread[count]; int current = start; for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(host, cur); if (portReady != null) portReady(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } Thread th = new Thread(() => { for (int i = 0; i < count; i++) threads[i].Join(); if (completed != null) completed(); }); th.IsBackground = true; th.Start(); } public static List<int> GetOpenedPorts(int count, string host, int start, int end) { Thread[] threads = new Thread[count]; int current = start; List<int> ports = new List<int>(); for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(host, cur); ports.Add(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } for (int i = 0; i < count; i++) threads[i].Join(); return ports; } private int count; private string host; private int start; private int end; public PortScan(int count, string host, int start, int end) { this.count = count; this.host = host; this.start = start; this.end = end; } public event Action<int> PortReady { add { PortScan.ScanOpenedPorts(count, host, start, end, value, null); } remove { } } public event Action Completed { add { PortScan.ScanOpenedPorts(count, host, start, end, null, value); } remove { } } }

昨天那个代码有点问题，如果两个事件都订阅处理程序，会扫描两次，所以又改了下。为了跟WinForm一致，写了两个虚方法来引发事件，实际上没有这个必要。

public class PortScan { public static void ScanOpenedPorts(int count, string host, int start, int end, Action<int> portReady, Action completed) { Thread[] threads = new Thread[count]; int current = start; for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(host, cur); if (portReady != null) portReady(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } Thread th = new Thread(() => { for (int i = 0; i < count; i++) threads[i].Join(); if (completed != null) try { completed(); } catch { } }); th.IsBackground = true; th.Start(); } public void ScanOpenedPorts(int count, string host, int start, int end) { ScanOpenedPorts(count, host, start, end, OnPortReady, OnCompleted); } public static List<int> GetOpenedPorts(int count, string host, int start, int end) { Thread[] threads = new Thread[count]; int current = start; List<int> ports = new List<int>(); for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(host, cur); ports.Add(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } for (int i = 0; i < count; i++) threads[i].Join(); return ports; } public event Action<int> PortReady; public event Action Completed; protected virtual void OnPortReady(int port) { if (PortReady != null) PortReady(port); } protected virtual void OnCompleted() { if (Completed != null) Completed(); } }

尝试对www.sina.com.cn进行扫描，结果非常慢，于是对代码进行了优化，解决了这个问题：

public class PortScan { public static void ScanOpenedPorts(int count, string host, int start, int end, Action<int> portReady, Action completed) { Network net = new Network(); if (!net.Ping(host)) throw new Exception("无法连接到主机:" + host); IPAddress ip = Dns.GetHostByName(host).AddressList[0]; Thread[] threads = new Thread[count]; int current = start; for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(ip,cur); if (portReady != null) portReady(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } Thread th = new Thread(() => { for (int i = 0; i < count; i++) threads[i].Join(); if (completed != null) try { completed(); } catch { } }); th.IsBackground = true; th.Start(); } public void ScanOpenedPorts(int count, string host, int start, int end) { ScanOpenedPorts(count, host, start, end, OnPortReady, OnCompleted); } public static List<int> GetOpenedPorts(int count, string host, int start, int end) { Network net = new Network(); if (!net.Ping(host)) throw new Exception("无法连接到主机:" + host); IPAddress ip = Dns.GetHostByName(host).AddressList[0]; Thread[] threads = new Thread[count]; int current = start; List<int> ports = new List<int>(); for (int i = 0; i < count; i++) { threads[i] = new Thread(() => { while (current++ <= end) { int cur = current; try { TcpClient tc = new TcpClient(); tc.Connect(ip, cur); ports.Add(cur); } catch { } } }); threads[i].IsBackground = true; threads[i].Start(); } for (int i = 0; i < count; i++) threads[i].Join(); return ports; } public event Action<int> PortReady; public event Action Completed; protected virtual void OnPortReady(int port) { if (PortReady != null) PortReady(port); } protected virtual void OnCompleted() { if (Completed != null) Completed(); } }