* Display a 6 byte device address (MAC) in a readable format.
*/
extern char *print_mac(char *buf, const unsigned char *addr);
+#define MAC_FMT "%02x:%02x:%02x:%02x:%02x:%02x"
#define MAC_BUF_SIZE 18
#define DECLARE_MAC_BUF(var) char var[MAC_BUF_SIZE] __maybe_unused