Searches the network database that is referenced by the
    TCPIP$NETWORK logical name for a network record with the
    specified address. If the network record is not found,
    this function may invoke the BIND resolver to search
    TCPIP$SYSTEM:NETWORKS.DAT.
    The $QIO equivalent is the IO$_ACPCONTROL function with the
    INETACP_FUNC$C_GETNETBYADDR subfunction code.
    Format
      #include  <netdb.h>
      struct netent *getnetbyaddr  ( long net, int type) ;