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函数原型参考https://msdn.microsoft.com/zh-cn/library/windows/desktop/aa366033(v=vs.85)
本文主要使用windows系统提供的GetUdpTable函数来获得指定端口是否被UDP使用，TCP端口使用情况类似，GetTcpTable函数可以实现。
// PortMonitoring.h: interface for the CPortMonitoring class.////#if !defined(AFX_PORTMONITORING_H__A8CBE1A3_0489_4DA0_862F_F3CDFFE4AB9C__INCLUDED_)#define AFX_PORTMONITORING_H__A8CBE1A3_0489_4DA0_862F_F3CDFFE4AB9C__INCLUDED_#if _MSC_VER > 1000#pragma once#endif // _MSC_VER > 1000typedef unsigned long DWORD;class CPortMonitoring{public: CPortMonitoring(); virtual ~CPortMonitoring(); //检测端口是否被占用 static bool CheckUdpPort(unsigned int nPort);};#endif // !defined(AFX_PORTMONITORING_H__A8CBE1A3_0489_4DA0_862F_F3CDFFE4AB9C__INCLUDED_) // PortMonitoring.cpp: implementation of the CPortMonitoring class.////#include#include "windows.h"#include "PortMonitoring.h"#define ANY_SIZE 120#ifdef _DEBUG#undef THIS_FILEstatic char THIS_FILE[] = __FILE__;//#define new DEBUG_NEW //DEBUG_NEW可以定位内存泄露#endif//// Construction/Destruction//CPortMonitoring::CPortMonitoring(){}CPortMonitoring::~CPortMonitoring(){}连接信息结构体typedef struct _MIB_UDPROW{ DWORD dwLocalAddr; // 本地计算机地址 DWORD dwLocalPort; // 本地计算机端口 //int dwProcessId; //进程id} MIB_UDPROW, *PMIB_UDPROW;TCP连接表typedef struct _MIB_UDPTABLE{ DWORD dwNumEntries; //当前包含MIB_UDPROW类型的总数 MIB_UDPROW table[ANY_SIZE]; //存放每个UDP连接的端口和IP} MIB_UDPTABLE, *PMIB_UDPTABLE;//检测端口是否被占用bool CPortMonitoring::CheckUdpPort(unsigned int nPort){ if (nPort < 1024 || nPort > 65000) return false; PMIB_UDPTABLE pudptable = NULL; DWORD dwSize = 0; HINSTANCE hInst; //动态链接库模块句柄 hInst = LoadLibraryA("iphlpapi.dll"); //动态加载iphlpapi.dll //定义函数指针类型 typedef long(__stdcall *ADDPROC) (PMIB_UDPTABLE pUdpTable, PDWORD pdwSize, BOOL bOrder); //获取iphlpapi.dll导出函数 ADDPROC GetUdpTable = (ADDPROC)GetProcAddress(hInst, "GetUdpTable"); if (GetUdpTable(pudptable, &dwSize, TRUE) == ERROR_INSUFFICIENT_BUFFER) //pTcpTable空间不足 { pudptable = new MIB_UDPTABLE[dwSize]; //为pUdpTable申请足够的空间 if (GetUdpTable(pudptable, &dwSize, TRUE) == NO_ERROR) //GetTcpTable调用成功 { //检测端口nPort是否在 for (UINT i = 0; i < pudptable->dwNumEntries; i++) { if (nPort != ntohs(pudptable->table[i].dwLocalPort)) continue; //释放资源 delete[] pudptable; FreeLibrary((HMODULE)hInst); return FALSE; } } } //释放资源 delete[] pudptable; FreeLibrary((HMODULE)hInst); return TRUE;}
下面是加上TCP检测的：
#include#include "windows.h"#include "port_detect_interface.h"#pragma comment(lib, "ws2_32.lib")PortDetectImpl::PortDetectImpl(){}PortDetectImpl::~PortDetectImpl(){}/*** 检测UDP端口是否被占用** @param [in] port 待检测端口号** @return bool: 0 未占用，1 占用*/bool PortDetectImpl::CheckUdpPort(unsigned int port){ if (port < 1024 || port > 65535) return TRUE; PMIB_UDPTABLE pudptable = NULL; DWORD dwSize = 0; HINSTANCE hInst; //动态链接库模块句柄 hInst = LoadLibraryA("iphlpapi.dll"); //动态加载iphlpapi.dll //定义函数指针类型 typedef long(__stdcall *ADDPROC) (PMIB_UDPTABLE pUdpTable, PDWORD pdwSize, BOOL bOrder); //获取iphlpapi.dll导出函数 ADDPROC GetUdpTable = (ADDPROC)GetProcAddress(hInst, "GetUdpTable"); if (GetUdpTable(pudptable, &dwSize, TRUE) == ERROR_INSUFFICIENT_BUFFER) //pTcpTable空间不足 { pudptable = new MIB_UDPTABLE[dwSize]; //为pTcpTable申请足够的空间 if (GetUdpTable(pudptable, &dwSize, TRUE) == NO_ERROR) //GetTcpTable调用成功 { //检测端口nPort是否在 for (UINT i = 0; i < pudptable->dwNumEntries; i++) { if (port != ntohs(pudptable->table[i].dwLocalPort)) continue; //释放资源 delete[] pudptable; FreeLibrary((HMODULE)hInst); return TRUE; } } } //释放资源 delete[] pudptable; FreeLibrary((HMODULE)hInst); return FALSE;}/*** 检测TCP端口是否被占用** @param [in] port 待检测端口号** @return bool: 0 未占用，1 占用*/bool PortDetectImpl::CheckTcpPort(unsigned int port){ if (port < 1024 || port > 65535) { return TRUE; } PMIB_TCPTABLE ptcptable = NULL; DWORD dwSize = 0; HINSTANCE hInst; //动态链接库模块句柄 hInst = LoadLibraryA("iphlpapi.dll"); //动态加载iphlpapi.dll //定义函数指针类型 typedef long(__stdcall *ADDPROC) (PMIB_TCPTABLE pTcpTable, PDWORD pdwSize, BOOL bOrder); //获取iphlpapi.dll导出函数 ADDPROC GetTcpTable = (ADDPROC)GetProcAddress(hInst, "GetTcpTable"); if (GetTcpTable(ptcptable, &dwSize, TRUE) == ERROR_INSUFFICIENT_BUFFER) //pTcpTable空间不足 { ptcptable = new MIB_TCPTABLE[dwSize]; //为pTcpTable申请足够的空间 if (GetTcpTable(ptcptable, &dwSize, TRUE) == NO_ERROR) //GetTcpTable调用成功 { //检测端口nPort是否在 for (UINT i = 0; i < ptcptable->dwNumEntries; i++) { if (port != ntohs(ptcptable->table[i].dwLocalPort)) continue; //释放资源 delete[] ptcptable; FreeLibrary((HMODULE)hInst); return TRUE; } } } //释放资源 delete[] ptcptable; FreeLibrary((HMODULE)hInst); return FALSE;}
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