两种方法获取网卡地址

1.AF_INET方法获取 

#include <stdio.h> 
#include <sys/types.h> 
#include <sys/param.h> 
#include <sys/ioctl.h> 
#include <sys/socket.h> 
#include <net/if.h> 
#include <netinet/in.h> 
#include <net/if_arp.h> 

#define MAXINTERFACES 16 

int main(argc, argv) 
register int argc; 
register char *argv[]; 
{ 
    register int fd, intrface, retn = 0; 
    struct ifreq buf[MAXINTERFACES]; 
    struct arpreq arp; 
    struct ifconf ifc; 

    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) >= 0) { 
      ifc.ifc_len = sizeof buf; 
      ifc.ifc_buf = (caddr_t) buf; 
      if (!ioctl(fd, SIOCGIFCONF, (char *) &ifc)) { 
          intrface = ifc.ifc_len / sizeof(struct ifreq); 
          printf("interface num is intrface=%d/n/n/n", intrface); 
          while (intrface-- > 0) { 
            printf("net device %s/n", buf[intrface].ifr_name); 

/*Jugde whether the net card status is promisc*/ 
            if (!(ioctl(fd, SIOCGIFFLAGS, (char *) &buf[intrface]))) { 
                if (buf[intrface].ifr_flags & IFF_PROMISC) { 
                  puts("the interface is PROMISC"); 
                  retn++; 
                } 
            } else { 
                char str[256]; 

                sprintf(str, "cpm: ioctl device %s", 
                      buf[intrface].ifr_name); 
                perror(str); 
            } 

/*Jugde whether the net card status is up*/ 
            if (buf[intrface].ifr_flags & IFF_UP) { 
                puts("the interface status is UP"); 
            } else { 
                puts("the interface status is DOWN"); 
            } 

/*Get IP of the net card */ 
            if (!(ioctl(fd, SIOCGIFADDR, (char *) &buf[intrface]))) { 
                puts("IP address is:"); 
                puts(inet_ntoa 
                   (((struct sockaddr_in *) (&buf[intrface]. 
                                       ifr_addr))->sin_addr)); 
                puts(""); 
//puts (buf[intrface].ifr_addr.sa_data); 
            } else { 
                char str[256]; 

                sprintf(str, "cpm: ioctl device %s", 
                      buf[intrface].ifr_name); 
                perror(str); 
            } 

/*Get HW ADDRESS of the net card */ 
            if (!(ioctl(fd, SIOCGIFHWADDR, (char *) &buf[intrface]))) { 
                puts("HW address is:"); 

                printf("%02x:%02x:%02x:%02x:%02x:%02x/n", 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[0], 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[1], 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[2], 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[3], 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[4], 
                     (unsigned char) buf[intrface].ifr_hwaddr. 
                     sa_data[5]); 

                puts(""); 
                puts(""); 
            } 

            else { 
                char str[256]; 

                sprintf(str, "cpm: ioctl device %s", 
                      buf[intrface].ifr_name); 
                perror(str); 
            } 
          } 
      } else 
          perror("cpm: ioctl"); 

    } else 
      perror("cpm: socket"); 

    close(fd); 
    return retn; 
} 


2.PF_PACKET方法获取网卡地址 

/* Low level network programming in Linux using PF_PACKET 

* Need root privileges */ 

#include <stdio.h> 

#include <sys/socket.h> 

#include <sys/errno.h> 

#include <linux/if.h> 

#include <linux/if_ether.h> 

#include <linux/if_arp.h> 

#include <linux/sockios.h> 


int main(int argc, char **argv) 

{ 

    int i, sockfd; 

    static struct ifreq req; 

    struct sockaddr_ll inside_address; 


    /* Low level socket */ 

    sockfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); 

    if (sockfd < 0) { 

        perror("Unable to create low level socket: "); 

        exit(1); 

    } 

    memset(&inside_address, 0, sizeof(inside_address)); 

    inside_address.sll_family = AF_PACKET; 

    inside_address.sll_protocol = htons(ETH_P_ALL); 

    inside_address.sll_hatype = ARPOP_REQUEST; 

    inside_address.sll_pkttype = PACKET_BROADCAST; 

    inside_address.sll_halen = 6; 

    strcpy(req.ifr_name, "eth1"); 

    ioctl(sockfd, SIOCGIFINDEX, &req); 

    inside_address.sll_ifindex = req.ifr_ifindex; 

    ioctl(sockfd, SIOCGIFHWADDR, &req); 

    if (bind(sockfd, (struct sockaddr *) &inside_address, 

             sizeof(inside_address)) != 0) { 

        perror("Error:"); 

        exit(1); 

    } 

    for (i = 0; i < 6; i++) 

        inside_address.sll_addr[i] = 

            (unsigned char) req.ifr_hwaddr.sa_data[i]; 

    printf("%X/n", inside_address.sll_ifindex); 

    for (i = 0; i < 5; i++) { 

        printf("%02X", inside_address.sll_addr[i]); 

        printf(":"); 

    } 

    printf("%02X/n", inside_address.sll_addr[i]); 

    close(sockfd); 

    return 0; 

}