C语言获取本地所有网卡的ip地址及MAC信息

// demo01.c
#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];

//get all the information of interface
int sockfd;
struct ifconf ifconf;
struct ifreq *ifreq;
char buf[512];

ifconf.ifc_len=512;
ifconf.ifc_buf=buf;
if( (sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0 )
{
perror("socket");
exit(1);
}
ioctl(sockfd, SIOCGIFCONF, &ifconf);

ifreq = (struct ifreq*)ifconf.ifc_buf;
int i=0;
printf("                        local ip&mac information\n");
printf("=======================================================================\n");
printf("    name                     ip                        mac      \n");
for(i=(ifconf.ifc_len/sizeof(struct ifreq)); i>0; i--)
{
if(ifreq->ifr_flags == AF_INET)
{
get_local_mac(ifreq->ifr_name, mac);
get_local_ip(ifreq->ifr_name, ip);
printf("    %-10s           %-20s   %-20s \n",ifreq->ifr_name, ip, mac);
ifreq++;
}
}
printf("=======================================================================\n");

return 0;
}

// get the ip address by domain
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;
}

// get the local host mac address
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;
}

// get the local host ip address
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;
}

#This is the makefile of EpollTest
.PHONY:all
all:demo01
server:
gcc demo01.c -o demo01
clean:
rm -f demo01