#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ifaddrs.h>           /* getifaddrs() */
#include <netinet/ether.h>     /* ether_ntoa() */
#include <netpacket/packet.h>  /* struct sockaddr_ll */

char *generic_ntoa(struct sockaddr *sa)
{
  static char *str = 0;
  static size_t size = 0;
  struct sockaddr_ll *sll;

  if ( size )
  {
    free(str);
    str = 0;
    size = 0;
  }

  switch ( sa->sa_family )
  {
    case AF_INET:
      size = INET_ADDRSTRLEN;
      str = malloc(size);
      memset((void *)str, 0, size);
      inet_ntop(((struct sockaddr_in *)sa)->sin_family,
                &(((struct sockaddr_in *)sa)->sin_addr),
                str, size);
      break;
    case AF_INET6:
      size = INET6_ADDRSTRLEN;
      str = malloc(size);
      memset((void *)str, 0, size);
      inet_ntop(((struct sockaddr_in6 *)sa)->sin6_family,
                &(((struct sockaddr_in6 *)sa)->sin6_addr),
                str, size);
      break;
    case AF_PACKET:
      sll = (struct sockaddr_ll *)sa;
      switch (sll->sll_hatype)
      {
        case ARPHRD_LOOPBACK:
          /* loopback interfaces don't have a hardware address */
          break;
        case ARPHRD_ETHER:
          str = ether_ntoa((struct ether_addr *)(sll->sll_addr));
          break;
        default:
          size = 40;
          str = malloc(size);
          memset((void *)str, 0, size);
          snprintf(str, size,
                   "Can't decode raw packet type %d", sll->sll_hatype);
          break;
      }
      break;
    default:
      size = 30;
      str = malloc(size);
      memset((void *)str, 0, size);
      snprintf(str, size, "Can't decode family %d", sa->sa_family);
      break;
  }

  return str;
}

int main()
{
  struct ifaddrs *id;
  char *address_str;
  int val;

  val = getifaddrs(&id);

  for ( ; id != NULL ; id = id->ifa_next )
  {
    printf("Network Interface: %s\n", id->ifa_name);

    address_str = generic_ntoa(id->ifa_addr);
    if ( address_str )
    {
      printf("Address:           %s\n", address_str);
    }

    if ( id->ifa_netmask != NULL )
    {
      address_str = generic_ntoa(id->ifa_netmask);
      printf("Netmask:           %s\n", address_str);
    }

    printf("\n");
  }

  return 0;
}