File Coverage

get_mac_linux.c

Criterion	Covered	Total	%
statement	12	23	52.1
branch	4	8	50.0
condition			n/a
subroutine			n/a
pod			n/a
total	16	31	51.6

/*
Perl ARP Extension
Get the MAC address of an interface
Linux code

Programmed by Bastian Ballmann
Last update: 11.05.2022

This program is free software; you can redistribute
it and/or modify it under the terms of the
GNU General Public License version 2 as published
by the Free Software Foundation.

This program is distributed in the hope that it will
be useful, but WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
*/

#include
#include
#include
#include
#include
#include
#include
#include
#include "arp.h"

int get_mac_linux(const char *dev, char *mac)
{
  int    sock;
  struct ifreq iface;

  if ( !strlen(mac) || !strlen(dev) )
    return -1;

  /* Set hardware address as unknown */
  strncpy(mac,"unknown", HEX_HW_ADDR_LEN);
  mac[HEX_HW_ADDR_LEN - 1] = '\0';

  /* Copy device name into the ifreq strcture so that we can look for its
   * hardware address through an ioctl request */
  strncpy(iface.ifr_name, dev, IFNAMSIZ);
  iface.ifr_name[IFNAMSIZ - 1] = '\0';

  // Open a socket
  if((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
  {
    perror("socket");
    return -1;
  }
  else
  {
    // Get the interface hardware address
    if((ioctl(sock, SIOCGIFHWADDR, &iface)) < 0)
	  {
	    perror("ioctl SIOCGIFHWADDR");
	    close(sock);
	    return -1;
	  }
    else
	  {
	    sprintf(mac,"%02x:%02x:%02x:%02x:%02x:%02x",
		          iface.ifr_hwaddr.sa_data[0] & 0xff,
		          iface.ifr_hwaddr.sa_data[1] & 0xff,
		          iface.ifr_hwaddr.sa_data[2] & 0xff,
              iface.ifr_hwaddr.sa_data[3] & 0xff,
              iface.ifr_hwaddr.sa_data[4] & 0xff,
              iface.ifr_hwaddr.sa_data[5] & 0xff);
	  }
  }

  close(sock);
  return 0;
}