rtw_get_wps_attr_content
rtw_get_wps_attr_content(pmlmepriv->wps_beacon_ie, pmlmepriv->wps_beacon_ie_len, WPS_ATTR_SELECTED_REGISTRAR, &selected_registrar, NULL);
rtw_get_wps_attr_content(wps_ie, wps_ielen, WPS_ATTR_SELECTED_REGISTRAR, (u8 *)(&sr), NULL);
u8 *rtw_get_wps_attr_content(u8 *wps_ie, uint wps_ielen, u16 target_attr_id, u8 *buf_content, uint *len_content);
psr = rtw_get_wps_attr_content(wpsie, wpsielen, WPS_ATTR_SELECTED_REGISTRAR, (u8 *)(&sr), NULL);