获取网卡IP地址信息——UDP套接字版

一时失言乱红尘 2021-09-19 01:02 347阅读 0赞

**一 代码**

#include <string.h> 
 #include <sys/socket.h> 
 #include <sys/ioctl.h> 
 #include <net/if.h> 
 #include <stdio.h> 
 #include <netinet/in.h> 
 #include <arpa/inet.h> 
 int main() 
 { 
 int inet_sock; 
 struct ifreq ifr; //定义网口请求结构体
 inet_sock = socket(AF_INET, SOCK_DGRAM, 0); 
 
 strcpy(ifr.ifr_name, "enp0s3"); 
 //SIOCGIFADDR标志代表获取接口地址 
 if (ioctl(inet_sock, SIOCGIFADDR, &ifr) < 0) 
 perror("ioctl"); 
 printf("%s\n", inet_ntoa(((struct sockaddr_in*)&(ifr.ifr_addr))->sin_addr)); 
 return 0; 
 }

**二 运行**

[root@localhost test]# g++ test.cpp -o test
    [root@localhost test]# ./test
    192.168.0.110

**三 说明**

1 ifreq结构体定义

Struct ifreq{
    Char ifr_name[IFNAMSIZ];
    Union{
        Struct  sockaddr  ifru_addr;
        Struct  sockaddr  ifru_dstaddr;
        Struct  sockaddr  ifru_broadaddr;
        Struct  sockaddr  ifru_netmask;
        Struct  sockaddr  ifru_hwaddr;
        Short  ifru_flags;
        Int     ifru_metric;
        Caddr_t ifru_data;
    }ifr_ifru;
    };
    #define ifr_addr        ifr_ifru.ifru_addr
    #define ifr_broadaddr   ifr_ifru.ifru_broadadd
    #define ifr_hwaddr      ifr_ifru_hwaddr

2 网络相关的ioctl请求的request参数及arg地址必须指向的数据类型如下表所示

<table style="width:600px;"> 
 <tbody> 
 <tr> 
 <td> 接口 </td> 
 <td> SIOCGIFCONF SIOCSIFADDR SIOCGIFADDR SIOCSIFBRDADDR SIOCGIFBRDADDR SIOCSIFNETMASK SIOCGIFNETMASK </td> 
 <td> 获取所有接口列表 设置接口地址 获取接口地址 设置广播地址 获取广播地址 设置子网掩码 获取子网掩码 </td> 
 <td> Struct &nbsp;ifconf Struct &nbsp;ifreq Struct &nbsp;ifreq Struct &nbsp;ifreq Struct &nbsp;ifreq Struct &nbsp;ifreq Struct &nbsp;ifreq </td> 
 </tr> 
 </tbody> 
</table>

**四 参考**

[https://blog.csdn.net/q\_l\_s/article/details/52716730][https_blog.csdn.net_q_l_s_article_details_52716730]

[https_blog.csdn.net_q_l_s_article_details_52716730]: https://blog.csdn.net/q_l_s/article/details/52716730