ioctl()获取本地网卡设备信息

获得eth0接口所有信息:

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <string.h>

unsigned char g_eth_name[16];
unsigned char g_macaddr[16];
unsigned int g_subnetmask;
unsigned int g_ipaddr;
unsigned int g_broadcast_ipaddr;

//初始化网络，获取当前网络设备信息
void init_net(void)
{
    int i ;
    int sock;
    struct sockaddr_in sin;
    struct ifreq ifr;

    sock=socket(AF_INET, SOCK_DGRAM, 0);
    if(sock==-1)
        perror("socket");
    strcpy(g_eth_name, "eth0");
    strcpy(ifr.ifr_name, g_eth_name);
    printf("eth name:\t%s\n", g_eth_name);

    //获取并打印网卡地址
    if(ioctl(sock, SIOCGIFHWADDR, &ifr) <0 )
        perror("ioctl error\n");
    memcpy(g_macaddr, ifr.ifr_hwaddr.sa_data, 6);
    printf("local mac:\t");
    for(i=0;i<5;i++)
        printf("%.2x:", g_macaddr[i]);
    printf("%.2x\n", g_macaddr[i]);

    //获取并打印IP地址
    if(ioctl(sock, SIOCGIFADDR, &ifr)<0)
        perror("ioctl error\n");
    memcpy(&sin, &ifr.ifr_addr, sizeof(sin));
    g_ipaddr = sin.sin_addr.s_addr;
    printf("local eth0:\t%s\n", inet_ntoa(sin.sin_addr));

    //获取并打印广播地址
    if(ioctl(sock, SIOCGIFBRDADDR, &ifr)<0)
        perror("ioctl error\n");
    memcpy(&sin, &ifr.ifr_addr, sizeof(sin));
    g_broadcast_ipaddr = sin.sin_addr.s_addr;
    printf("broadcast:\t%s\n", inet_ntoa(sin.sin_addr));

    //获取并打印子网掩码
    if(ioctl(sock,SIOCGIFNETMASK,&ifr)<0)
        perror("ioctl error\n");
    memcpy(&sin, &ifr.ifr_addr, sizeof(sin));
    g_subnetmask = sin.sin_addr.s_addr;
    printf("subnetmask:\t%s\n", inet_ntoa(sin.sin_addr));

    close(sock);
}

int main()
{
    //initialize
    init_net();
    //do something
    //....
    return 0;
}

获取所有IP:

#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <stdio.h>
#include <linux/if.h>
#include <arpa/inet.h>

int main()
{
    int i=0;
    int sockfd;
    struct ifconf ifconf;
    unsigned char buf[512];
    struct ifreq *ifreq;
    //初始化ifconf
    ifconf.ifc_len = 512;
    ifconf.ifc_buf = buf;

    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    {
        perror("socket open failure!\n" );
        exit(1);
    }

    ioctl(sockfd, SIOCGIFCONF, &ifconf); //获取所有接口信息
    //接下来一个一个的获取IP地址
    ifreq = (struct ifreq*)buf;
    for (i=(ifconf.ifc_len/sizeof (struct ifreq)); i>0; i--)
    {
        if(ifreq->ifr_flags == AF_INET)
        {
            printf("name = [%s]  " , ifreq->ifr_name);
            printf("local addr = [%s]",
                inet_ntoa(((struct sockaddr_in*)&(ifreq->ifr_addr))->sin_addr));
            printf();
        ifreq++;
        }
    }
    return 0;
}

获取本机的IP和MAC地址:

/* 得到本机的mac地址和ip地址 */
int GetLocalMac ( const char *device,char *mac,char *ip )
{
    int sockfd;
    struct ifreq req;
    struct sockaddr_in * sin;

    if ( ( sockfd = socket ( PF_INET,SOCK_DGRAM,0 ) ) ==-1 )
    {
        fprintf ( stderr,"Sock Error:%s\n\a",strerror ( errno ) );
        return ( -1 );
    }

    memset ( &req,0,sizeof ( req ) );
    strcpy ( req.ifr_name,device );
    if ( ioctl ( sockfd,SIOCGIFHWADDR, ( char * ) &req ) ==-1 )
    {
        fprintf ( stderr,"ioctl SIOCGIFHWADDR:%s\n\a",strerror ( errno ) );
        close ( sockfd );
        return ( -1 );
    }
    memcpy ( mac,req.ifr_hwaddr.sa_data,6 );

    req.ifr_addr.sa_family = PF_INET;
    if ( ioctl ( sockfd,SIOCGIFADDR, ( char * ) &req ) ==-1 )
    {
        fprintf ( stderr,"ioctl SIOCGIFADDR:%s\n\a",strerror ( errno ) );
        close ( sockfd );
        return ( -1 );
    }
    sin = ( struct sockaddr_in * ) &req.ifr_addr;
    memcpy ( ip, ( char * ) &sin->sin_addr,4 );

    return ( 0 );
}