LINUX C: 获取本地指定网卡的IP地址

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include <unistd.h>

#include <netdb.h>

#include <net/if.h>

#include <arpa/inet.h>

#include <sys/ioctl.h>

#include <sys/types.h>

#include <sys/socket.h>

#define MAC_SIZE    18

#define IP_SIZE     16

// function declare

int get_ip_by_domain(const char *domain, char *ip); // 根据域名获取ip

int get_local_mac(const char *eth_inf, char *mac); // 获取本机mac

int get_local_ip(const char *eth_inf, char *ip); // 获取本机ip

/****** main test **********/

int main(void)

{

    char ip[IP_SIZE];

    char mac[MAC_SIZE];

    const char *test_domain = "www.baidu.com";

    const char *test_eth = "eth0";

    get_ip_by_domain(test_domain, ip);

    printf("%s ip: %s\n", test_domain, ip);

    get_local_mac(test_eth, mac);

    printf("local %s mac: %s\n", test_eth, mac);

    get_local_ip(test_eth, ip);

    printf("local %s ip: %s\n", test_eth, ip);

    return 0;

}

// 根据域名获取ip

int get_ip_by_domain(const char *domain, char *ip)

{

    char **pptr;

    struct hostent *hptr;

    hptr = gethostbyname(domain);

    if(NULL == hptr)

    {

        printf("gethostbyname error for host:%s/n", domain);

        return -1;

    }

    for(pptr = hptr->h_addr_list ; *pptr != NULL; pptr++)

    {

        if (NULL != inet_ntop(hptr->h_addrtype, *pptr, ip, IP_SIZE) )

        {

            return 0; // 只获取第一个 ip

        }

    }

    return -1;

}

// 获取本机mac

int get_local_mac(const char *eth_inf, char *mac)

{

    struct ifreq ifr;

    int sd;

    bzero(&ifr, sizeof(struct ifreq));

    if( (sd = socket(AF_INET, SOCK_STREAM, 0)) < 0)

    {

        printf("get %s mac address socket creat error\n", eth_inf);

        return -1;

    }

    strncpy(ifr.ifr_name, eth_inf, sizeof(ifr.ifr_name) - 1);

    if(ioctl(sd, SIOCGIFHWADDR, &ifr) < 0)

    {

        printf("get %s mac address error\n", eth_inf);

        close(sd);

        return -1;

    }

    snprintf(mac, MAC_SIZE, "%02x:%02x:%02x:%02x:%02x:%02x",

        (unsigned char)ifr.ifr_hwaddr.sa_data[0],

        (unsigned char)ifr.ifr_hwaddr.sa_data[1],

        (unsigned char)ifr.ifr_hwaddr.sa_data[2],

        (unsigned char)ifr.ifr_hwaddr.sa_data[3],

        (unsigned char)ifr.ifr_hwaddr.sa_data[4],

        (unsigned char)ifr.ifr_hwaddr.sa_data[5]);

    close(sd);

    return 0;

}

// 获取本机ip

int get_local_ip(const char *eth_inf, char *ip)

{

    int sd;

    struct sockaddr_in sin;

    struct ifreq ifr;

    sd = socket(AF_INET, SOCK_DGRAM, 0);

    if (-1 == sd)

    {

        printf("socket error: %s\n", strerror(errno));

        return -1;

    }

    strncpy(ifr.ifr_name, eth_inf, IFNAMSIZ);

    ifr.ifr_name[IFNAMSIZ - 1] = 0;

    // if error: No such device

    if (ioctl(sd, SIOCGIFADDR, &ifr) < 0)

    {

        printf("ioctl error: %s\n", strerror(errno));

        close(sd);

        return -1;

    }

    memcpy(&sin, &ifr.ifr_addr, sizeof(sin));

    snprintf(ip, IP_SIZE, "%s", inet_ntoa(sin.sin_addr));

    close(sd);

    return 0;

}
巴特西

LINUX C: 获取本地指定网卡的IP地址

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