NAME

  tst_if_index_to_name_bad - Return a NULL pointer if ifindex is not an interface index


PURPOSE

  To check if ifindex is not an interface index then the function
  shall return a NULL pointer and set errno to indicate the error.


SYNOPSIS

  ./tst_if_index_to_name_bad [-tooloption ...]
    -tooloption : v6api tool option


TEST PROCEDURE

  1. The argument ifindex 0 is not an interface index, shall return a NULL pointer
  2. The argument ifindex 10000 is the interface index, shall return a NULL pointer


NOTE

  None


REFERENCE

  RFC 3493
  4.2 Index-to-Name
    The second function maps an interface index into its corresponding
    name.
      #include <net/if.h>
      char  *if_indextoname(unsigned int ifindex, char *ifname);
    When this function is called, the ifname argument shall point to a
    buffer of at least IF_NAMESIZE bytes.  The function shall place in
    this buffer the name of the interface with index ifindex.
    (IF_NAMESIZE is also defined in <net/if.h> and its value includes a
    terminating null byte at the end of the interface name.)  If ifindex
    is an interface index, then the function shall return the value
    supplied in ifname, which points to a buffer now containing the
    interface name.  Otherwise, the function shall return a NULL pointer
    and set errno to indicate the error.  If there is no interface
    corresponding to the specified index, errno is set to ENXIO.  If
    there was a system error (such as running out of memory), errno would
    be set to the proper value (e.g., ENOMEM).