get arp type

gistfile1.txt

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/ethtool.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <string.h>
#include <errno.h>
#include <net/if_arp.h>


static int arptype(const char *device)
{
    struct ifreq ifr;

    memset(&ifr, 0, sizeof(ifr));
    strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));

    int fd = socket(PF_PACKET, SOCK_DGRAM, 0);
    if (fd == -1) {
        perror("get raw socket fail");
        return -1;
    }

    if (ioctl(fd, SIOCGIFHWADDR, &ifr) == -1) {
        perror("ioctl SIOCGIFHWADDR fail");
        return -1;
    }

    return ifr.ifr_hwaddr.sa_family;
}

int main()
{
    const char *device = "eth0";
    int arp_type = arptype(device);
    switch (arp_type) {
        case ARPHRD_ETHER:
            printf("device %s's arptype is ARPHRD_ETHER'\n", device);
            break;
        default:
            printf("device %s's arptype is %d'\n", device, arp_type);
    }
    if (arp_type == -1) {
        fprintf(stderr, "fail to get arp type\n");
    }    

    return 0;
}