ioctl接口

ioctl接口

例: 取出网络接口信息

myioctl_net.c

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

unsigned char    g_eth_name[16];
unsigned char    g_macaddr[6];
unsigned int    g_subnetmask;
unsigned int    g_ipaddr;
unsigned int    g_broadcast_ipaddr;

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);


    if (ioctl(sock, SIOCGIFHWADDR, &ifr) < 0) {
        perror("ioctl");
    }
    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]);

    if (ioctl(sock, SIOCGIFADDR, &ifr) < 0) {
        perror("ioctl");
    }
    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));

    if (ioctl(sock, SIOCGIFBRDADDR, &ifr) < 0) {
        perror("ioctl");
    }
    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));

    if (ioctl(sock, SIOCGIFNETMASK, &ifr) < 0) {
        perror("ioctl");
    }
    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()
{
    init_net();

    return 0;
}

编译链接执行后, 输出网络信息如下: