The ldap_get_entry_controls() function is used to extract LDAP
    controls from an entry.

      int ldap_get_entry_controls(
              LDAP                                    *ld,
              LDAPMessage                             *entry,
              LDAPControl                             ***serverctrlsp
      );

    Parameters are as follows:

    ld             The session handle.
    entry          The entry to extract controls from, as returned by
                   ldap_first_entry() or ldap_next_entry().
    serverctrlsp   This result parameter will be filled in with an
                   allocated array of controls copied out of entry.
                   The control array should be freed by calling
                   ldap_controls_free(). If serverctrlsp is NULL,
                   no controls are returned.

    The ldap_get_entry_controls() function returns an LDAP error code
    that indicates whether the reference could be successfully parsed
    (LDAP_SUCCESS if all goes well).