diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 762c7df4cd8..f210c4a0290 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1968,4 +1968,57 @@ static inline bool ieee80211_check_tim(struct ieee80211_tim_ie *tim, return !!(tim->virtual_map[index] & mask); } +struct element { + u8 id; + u8 datalen; + u8 data[]; +}; + +/* element iteration helpers */ +#define for_each_element(element, _data, _datalen) \ + for (element = (void *)(_data); \ + (u8 *)(_data) + (_datalen) - (u8 *)element >= \ + sizeof(*element) && \ + (u8 *)(_data) + (_datalen) - (u8 *)element >= \ + sizeof(*element) + element->datalen; \ + element = (void *)(element->data + element->datalen)) + +#define for_each_element_id(element, _id, data, datalen) \ + for_each_element(element, data, datalen) \ + if (element->id == (_id)) + +#define for_each_element_extid(element, extid, data, datalen) \ + for_each_element(element, data, datalen) \ + if (element->id == WLAN_EID_EXTENSION && \ + element->datalen > 0 && \ + element->data[0] == (extid)) + +#define for_each_subelement(sub, element) \ + for_each_element(sub, (element)->data, (element)->datalen) + +#define for_each_subelement_id(sub, id, element) \ + for_each_element_id(sub, id, (element)->data, (element)->datalen) + +#define for_each_subelement_extid(sub, extid, element) \ + for_each_element_extid(sub, extid, (element)->data, (element)->datalen) + +/** + * for_each_element_completed - determine if element parsing consumed all data + * @element: element pointer after for_each_element() or friends + * @data: same data pointer as passed to for_each_element() or friends + * @datalen: same data length as passed to for_each_element() or friends + * + * This function returns %true if all the data was parsed or considered + * while walking the elements. Only use this if your for_each_element() + * loop cannot be broken out of, otherwise it always returns %false. + * + * If some data was malformed, this returns %false since the last parsed + * element will not fill the whole remaining data. + */ +static inline bool for_each_element_completed(const struct element *element, + const void *data, size_t datalen) +{ + return (u8 *)element == (u8 *)data + datalen; +} + #endif /* LINUX_IEEE80211_H */