Is there a way to get interface's MAC address via getifaddrs() ?
I already have this, to get IP addresses, but I have kinda missed MAC. Ive tried to look for the information in getifaddrs(), but there is nothing about MAC addresses
struct ifaddrs *iflist, *iface;
  if (getifaddrs(&iflist) < 0) 
  {
      perror("getifaddrs");
  }
  char addrp[INET6_ADDRSTRLEN];
  char macp[INET6_ADDRSTRLEN];
  int i=0;
  for (iface = iflist; iface; iface = iface->ifa_next) 
  {
    int af = iface->ifa_addr->sa_family;
    const void *addr;
    const void *mac;
      switch (af) 
      {
        case AF_INET:
          addr = &((struct sockaddr_in *)iface->ifa_addr)->sin_addr;
          break;
      //get mac address somehow?
        default:
          addr = NULL;
      }
      if (addr) 
      {
        if (inet_ntop(af, addr, addrp, sizeof addrp) == NULL)
        {
           perror("inet_ntop");
           continue;
        }
    if (inet_ntop(af, mac, macp, sizeof macp) == NULL) // this is already for MAC add
        {
           perror("inet_ntop");
           continue;
        }
    if (strcmp(addrp, "127.0.0.1") != 0) 
    {
       strcat(tableO[i].IPaddr, addrp);
       strcat(tableO[i].MACaddr, macp);
       i++;
    }
      }
Thanks
the file /sys/class/net/eth0/address carries your mac adress as simple string you can read with fopen() / fscanf() / fclose() . Nothing easier than that. And if you want to support other network interfaces than eth0 (and you probably want), then simply use opendir() / readdir() / closedir() on /sys/class/net/ .
The getifaddrs() function stores a reference to a linked list of ifaddrs structures, one structure per interface. The end of the linked list of structures is indicated by a structure with an ifa_next of NULL.
The getifaddrs() function creates a linked list of structures describing the network interfaces of the local system, and stores the address of the first item of the list in *ifap.
On Linux, you'd do something like this
 case AF_PACKET:  {
            struct sockaddr_ll *s = (struct sockaddr_ll*)iface->ifa_addr;
            int i;
            int len = 0;
            for(i = 0; i < 6; i++)
                len+=sprintf(macp+len,"%02X%s",s->sll_addr[i],i < 5 ? ":":"");
        }
Though, there might be more members of the struct sockaddr_ll you'd want to inspect, see here for a description.
getifaddrs() already provides the MAC address associated with each interface. On Linux, when you bump into a family == AF_PACKET that is the MAC address. Same thing on OSX / BSD but in that case the family will be AF_LINK.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With