Commit fd17bf04 authored by Johannes Berg's avatar Johannes Berg
Browse files

wifi: mac80211: refactor elements parsing with parameter struct 



Refactor the element parsing into a version that has
a parameter struct so we can add more parameters more
easily in the future.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 5cd212cb

net/mac80211/ieee80211_i.h

+45 −5
Original line number Diff line number Diff line
@@ -2138,11 +2138,51 @@ static inline void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, 
	ieee80211_tx_skb_tid(sdata, skb, 7);

}



struct ieee802_11_elems *ieee802_11_parse_elems_crc(const u8 *start, size_t len,

						    bool action,

/**

 * struct ieee80211_elems_parse_params - element parsing parameters

 * @start: pointer to the elements

 * @len: length of the elements

 * @action: %true if the elements came from an action frame

 * @filter: bitmap of element IDs to filter out while calculating

 *	the element CRC

 * @crc: CRC starting value

 * @transmitter_bssid: transmitter BSSID to parse the multi-BSSID

 *	element

 * @bss_bssid: BSSID of the BSS we want to obtain elements for

 *	when parsing the multi-BSSID element

 */

struct ieee80211_elems_parse_params {

	const u8 *start;

	size_t len;

	bool action;

	u64 filter;

	u32 crc;

	const u8 *transmitter_bssid;

	const u8 *bss_bssid;

};



struct ieee802_11_elems *

ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params);



static inline struct ieee802_11_elems *

ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,

			   u64 filter, u32 crc,

			   const u8 *transmitter_bssid,

						    const u8 *bss_bssid);

			   const u8 *bss_bssid)

{

	struct ieee80211_elems_parse_params params = {

		.start = start,

		.len = len,

		.action = action,

		.filter = filter,

		.crc = crc,

		.transmitter_bssid = transmitter_bssid,

		.bss_bssid = bss_bssid,

	};



	return ieee802_11_parse_elems_full(&params);

}



static inline struct ieee802_11_elems *

ieee802_11_parse_elems(const u8 *start, size_t len, bool action,

		       const u8 *transmitter_bssid,

net/mac80211/util.c

+29 −29
Original line number Diff line number Diff line
@@ -1026,19 +1026,19 @@ static void ieee80211_parse_extension_element(u32 *crc, 
}



static u32

_ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,

_ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params,

			     struct ieee802_11_elems *elems,

			    u64 filter, u32 crc,

			     const struct element *check_inherit)

{

	const struct element *elem;

	bool calc_crc = filter != 0;

	bool calc_crc = params->filter != 0;

	DECLARE_BITMAP(seen_elems, 256);

	u32 crc = params->crc;

	const u8 *ie;



	bitmap_zero(seen_elems, 256);



	for_each_element(elem, start, len) {

	for_each_element(elem, params->start, params->len) {

		bool elem_parse_failed;

		u8 id = elem->id;

		u8 elen = elem->datalen;
@@ -1101,7 +1101,7 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, 
			break;

		}



		if (calc_crc && id < 64 && (filter & (1ULL << id)))

		if (calc_crc && id < 64 && (params->filter & (1ULL << id)))

			crc = crc32_be(crc, pos - 2, elen + 2);



		elem_parse_failed = false;
@@ -1282,7 +1282,7 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, 
			elems->mesh_chansw_params_ie = (void *)pos;

			break;

		case WLAN_EID_WIDE_BW_CHANNEL_SWITCH:

			if (!action ||

			if (!params->action ||

			    elen < sizeof(*elems->wide_bw_chansw_ie)) {

				elem_parse_failed = true;

				break;
@@ -1290,7 +1290,7 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, 
			elems->wide_bw_chansw_ie = (void *)pos;

			break;

		case WLAN_EID_CHANNEL_SWITCH_WRAPPER:

			if (action) {

			if (params->action) {

				elem_parse_failed = true;

				break;

			}
@@ -1417,7 +1417,7 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, 
			__set_bit(id, seen_elems);

	}



	if (!for_each_element_completed(elem, start, len))

	if (!for_each_element_completed(elem, params->start, params->len))

		elems->parse_error = true;



	return crc;
@@ -1491,11 +1491,8 @@ static size_t ieee802_11_find_bssid_profile(const u8 *start, size_t len, 
	return found ? profile_len : 0;

}



struct ieee802_11_elems *ieee802_11_parse_elems_crc(const u8 *start, size_t len,

						    bool action, u64 filter,

						    u32 crc,

						    const u8 *transmitter_bssid,

						    const u8 *bss_bssid)

struct ieee802_11_elems *

ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params)

{

	struct ieee802_11_elems *elems;

	const struct element *non_inherit = NULL;
@@ -1505,15 +1502,16 @@ struct ieee802_11_elems *ieee802_11_parse_elems_crc(const u8 *start, size_t len, 
	elems = kzalloc(sizeof(*elems), GFP_ATOMIC);

	if (!elems)

		return NULL;

	elems->ie_start = start;

	elems->total_len = len;

	elems->ie_start = params->start;

	elems->total_len = params->len;



	nontransmitted_profile = kmalloc(len, GFP_ATOMIC);

	nontransmitted_profile = kmalloc(params->len, GFP_ATOMIC);

	if (nontransmitted_profile) {

		nontransmitted_profile_len =

			ieee802_11_find_bssid_profile(start, len, elems,

						      transmitter_bssid,

						      bss_bssid,

			ieee802_11_find_bssid_profile(params->start, params->len,

						      elems,

						      params->transmitter_bssid,

						      params->bss_bssid,

						      nontransmitted_profile);

		non_inherit =

			cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE,
@@ -1521,14 +1519,18 @@ struct ieee802_11_elems *ieee802_11_parse_elems_crc(const u8 *start, size_t len, 
					       nontransmitted_profile_len);

	}



	crc = _ieee802_11_parse_elems_crc(start, len, action, elems, filter,

					  crc, non_inherit);

	elems->crc = _ieee802_11_parse_elems_full(params, elems, non_inherit);



	/* Override with nontransmitted profile, if found */

	if (nontransmitted_profile_len)

		_ieee802_11_parse_elems_crc(nontransmitted_profile,

					    nontransmitted_profile_len,

					    action, elems, 0, 0, NULL);

	if (nontransmitted_profile_len) {

		struct ieee80211_elems_parse_params sub = {

			.start = nontransmitted_profile,

			.len = nontransmitted_profile_len,

			.action = params->action,

		};



		_ieee802_11_parse_elems_full(&sub, elems, NULL);

	}



	if (elems->tim && !elems->parse_error) {

		const struct ieee80211_tim_ie *tim_ie = elems->tim;
@@ -1550,8 +1552,6 @@ struct ieee802_11_elems *ieee802_11_parse_elems_crc(const u8 *start, size_t len, 


	kfree(nontransmitted_profile);



	elems->crc = crc;



	return elems;

}