C++利用SIO_GET_INTERFACE_LIST查询网关

阳光穿透心脏的1/2处 2023-07-12 08:58 12阅读 0赞

本文提供利用SIO\_GET\_INTERFACE\_LIST实现本地网关查询的简单工具代码。

#include <iostream>
    #define WIN32_LEAN_AND_MEAN
    
    #include <windows.h>
    #include <winsock2.h>
    #include <ws2tcpip.h>
    #include <stdio.h>
    
    // Need to link with Ws2_32.lib
    #pragma comment(lib, "ws2_32.lib")
    
    using namespace std;
    
    int doit()
    { 
    	//创建套接字
        SOCKET sd = WSASocket(AF_INET, SOCK_DGRAM, 0, 0, 0, 0);
        if (sd == SOCKET_ERROR) { 
            cerr << "Failed to get a socket. Error " << WSAGetLastError() <<
                endl; return 1;
        }
    
    	//获取网关信息，保存在InterfancList中
        INTERFACE_INFO InterfaceList[20];
        unsigned long nBytesReturned;
        if (WSAIoctl(sd, SIO_GET_INTERFACE_LIST, 0, 0, &InterfaceList,
            sizeof(InterfaceList), &nBytesReturned, 0, 0) == SOCKET_ERROR) { 
            cerr << "Failed calling WSAIoctl: error " << WSAGetLastError() <<
                endl;
            return 1;
        }
    
    	//轮询读取信息并打印
        int nNumInterfaces = nBytesReturned / sizeof(INTERFACE_INFO);
        cout << "There are " << nNumInterfaces << " interfaces:" << endl;
        for (int i = 0; i < nNumInterfaces; ++i) { 
            cout << endl;
    
            char sendBuf[20] = {  '\0' };
            sockaddr_in *pAddress;
            pAddress = (sockaddr_in *)&(InterfaceList[i].iiAddress);
            cout << " " << inet_ntop(AF_INET, &pAddress->sin_addr, sendBuf, 16) << endl;
    
            pAddress = (sockaddr_in *)&(InterfaceList[i].iiBroadcastAddress);
            cout << " has bcast " << inet_ntop(AF_INET, &pAddress->sin_addr, sendBuf, 16) << endl;
    
            pAddress = (sockaddr_in *)&(InterfaceList[i].iiNetmask);
            cout << " and netmask " << inet_ntop(AF_INET, &pAddress->sin_addr, sendBuf, 16) << endl;
    
            cout << " Iface is ";
    
            u_long nFlags = InterfaceList[i].iiFlags;
            if (nFlags & IFF_UP) 
                cout << "up";
            else                 
                cout << "down";
    
            if (nFlags & IFF_POINTTOPOINT) 
                cout << ", is point-to-point";
    
            if (nFlags & IFF_LOOPBACK)     
                cout << ", is a loopback iface";
    
            cout << ", and can do: ";
    
            if (nFlags & IFF_BROADCAST) 
                cout << "bcast ";
    
            if (nFlags & IFF_MULTICAST) 
                cout << "multicast ";
    
            cout << endl;
        }
    
        return 0;
    }
    
    int main()
    { 
        WSADATA WinsockData;
        if (WSAStartup(MAKEWORD(2, 2), &WinsockData) != 0) { 
            cerr << "Failed to find Winsock 2.2!" << endl;
            return 2;
        }
    
        int nRetVal = doit();
    
        WSACleanup();
    
        return nRetVal;
    }