net/mac80211/sta_info.h - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2002-2005, Devicescape Software, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #ifndef STA_INFO_H
 #define STA_INFO_H

 #include <linux/list.h>
 #include <linux/types.h>
 #include <linux/if_ether.h>
 #include <linux/workqueue.h>
 #include <linux/average.h>
 #include "key.h"

 /**
  * enum ieee80211_sta_info_flags - Stations flags
  *
  * These flags are used with &struct sta_info's @flags member.
  *
  * @WLAN_STA_AUTH: Station is authenticated.
  * @WLAN_STA_ASSOC: Station is associated.
  * @WLAN_STA_PS_STA: Station is in power-save mode
  * @WLAN_STA_AUTHORIZED: Station is authorized to send/receive traffic.
  *	This bit is always checked so needs to be enabled for all stations
  *	when virtual port control is not in use.
  * @WLAN_STA_SHORT_PREAMBLE: Station is capable of receiving short-preamble
  *	frames.
  * @WLAN_STA_ASSOC_AP: We're associated to that station, it is an AP.
  * @WLAN_STA_WME: Station is a QoS-STA.
  * @WLAN_STA_WDS: Station is one of our WDS peers.
  * @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
  *	IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
  *	frame to this station is transmitted.
  * @WLAN_STA_MFP: Management frame protection is used with this STA.
  * @WLAN_STA_BLOCK_BA: Used to deny ADDBA requests (both TX and RX)
  *	during suspend/resume and station removal.
  * @WLAN_STA_PS_DRIVER: driver requires keeping this station in
  *	power-save mode logically to flush frames that might still
  *	be in the queues
  * @WLAN_STA_PSPOLL: Station sent PS-poll while driver was keeping
  *	station in power-save mode, reply when the driver unblocks.
  */
 enum ieee80211_sta_info_flags {
 	WLAN_STA_AUTH		= 1<<0,
 	WLAN_STA_ASSOC		= 1<<1,
 	WLAN_STA_PS_STA		= 1<<2,
 	WLAN_STA_AUTHORIZED	= 1<<3,
 	WLAN_STA_SHORT_PREAMBLE	= 1<<4,
 	WLAN_STA_ASSOC_AP	= 1<<5,
 	WLAN_STA_WME		= 1<<6,
 	WLAN_STA_WDS		= 1<<7,
 	WLAN_STA_CLEAR_PS_FILT	= 1<<9,
 	WLAN_STA_MFP		= 1<<10,
 	WLAN_STA_BLOCK_BA	= 1<<11,
 	WLAN_STA_PS_DRIVER	= 1<<12,
 	WLAN_STA_PSPOLL		= 1<<13,
 };

 #define STA_TID_NUM 16
 #define ADDBA_RESP_INTERVAL HZ
 #define HT_AGG_MAX_RETRIES		0x3

 #define HT_AGG_STATE_DRV_READY		0
 #define HT_AGG_STATE_RESPONSE_RECEIVED	1
 #define HT_AGG_STATE_OPERATIONAL	2
 #define HT_AGG_STATE_STOPPING		3
 #define HT_AGG_STATE_WANT_START		4
 #define HT_AGG_STATE_WANT_STOP		5

 /**
  * struct tid_ampdu_tx - TID aggregation information (Tx).
  *
  * @rcu_head: rcu head for freeing structure
  * @addba_resp_timer: timer for peer's response to addba request
  * @pending: pending frames queue -- use sta's spinlock to protect
  * @dialog_token: dialog token for aggregation session
  * @timeout: session timeout value to be filled in ADDBA requests
  * @state: session state (see above)
  * @stop_initiator: initiator of a session stop
  * @tx_stop: TX DelBA frame when stopping
  * @buf_size: reorder buffer size at receiver
  *
  * This structure's lifetime is managed by RCU, assignments to
  * the array holding it must hold the aggregation mutex.
  *
  * The TX path can access it under RCU lock-free if, and
  * only if, the state has the flag %HT_AGG_STATE_OPERATIONAL
  * set. Otherwise, the TX path must also acquire the spinlock
  * and re-check the state, see comments in the tx code
  * touching it.
  */
 struct tid_ampdu_tx {
 	struct rcu_head rcu_head;
 	struct timer_list addba_resp_timer;
 	struct sk_buff_head pending;
 	unsigned long state;
 	u16 timeout;
 	u8 dialog_token;
 	u8 stop_initiator;
 	bool tx_stop;
 	u8 buf_size;
 };

 /**
  * struct tid_ampdu_rx - TID aggregation information (Rx).
  *
  * @reorder_buf: buffer to reorder incoming aggregated MPDUs
  * @reorder_time: jiffies when skb was added
  * @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
  * @reorder_timer: releases expired frames from the reorder buffer.
  * @head_seq_num: head sequence number in reordering buffer.
  * @stored_mpdu_num: number of MPDUs in reordering buffer
  * @ssn: Starting Sequence Number expected to be aggregated.
  * @buf_size: buffer size for incoming A-MPDUs
  * @timeout: reset timer value (in TUs).
  * @dialog_token: dialog token for aggregation session
  * @rcu_head: RCU head used for freeing this struct
  * @reorder_lock: serializes access to reorder buffer, see below.
  *
  * This structure's lifetime is managed by RCU, assignments to
  * the array holding it must hold the aggregation mutex.
  *
  * The @reorder_lock is used to protect the members of this
  * struct, except for @timeout, @buf_size and @dialog_token,
  * which are constant across the lifetime of the struct (the
  * dialog token being used only for debugging).
  */
 struct tid_ampdu_rx {
 	struct rcu_head rcu_head;
 	spinlock_t reorder_lock;
 	struct sk_buff **reorder_buf;
 	unsigned long *reorder_time;
 	struct timer_list session_timer;
 	struct timer_list reorder_timer;
 	u16 head_seq_num;
 	u16 stored_mpdu_num;
 	u16 ssn;
 	u16 buf_size;
 	u16 timeout;
 	u8 dialog_token;
 };

 /**
  * struct sta_ampdu_mlme - STA aggregation information.
  *
  * @tid_rx: aggregation info for Rx per TID -- RCU protected
  * @tid_tx: aggregation info for Tx per TID
  * @addba_req_num: number of times addBA request has been sent.
  * @dialog_token_allocator: dialog token enumerator for each new session;
  * @work: work struct for starting/stopping aggregation
  * @tid_rx_timer_expired: bitmap indicating on which TIDs the
  *	RX timer expired until the work for it runs
  * @mtx: mutex to protect all TX data (except non-NULL assignments
  *	to tid_tx[idx], which are protected by the sta spinlock)
  */
 struct sta_ampdu_mlme {
 	struct mutex mtx;
 	/* rx */
 	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
 	unsigned long tid_rx_timer_expired[BITS_TO_LONGS(STA_TID_NUM)];
 	/* tx */
 	struct work_struct work;
 	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
 	u8 addba_req_num[STA_TID_NUM];
 	u8 dialog_token_allocator;
 };


 /**
  * enum plink_state - state of a mesh peer link finite state machine
  *
  * @PLINK_LISTEN: initial state, considered the implicit state of non existent
  * 	mesh peer links
  * @PLINK_OPN_SNT: mesh plink open frame has been sent to this mesh peer
  * @PLINK_OPN_RCVD: mesh plink open frame has been received from this mesh peer
  * @PLINK_CNF_RCVD: mesh plink confirm frame has been received from this mesh
  * 	peer
  * @PLINK_ESTAB: mesh peer link is established
  * @PLINK_HOLDING: mesh peer link is being closed or cancelled
  * @PLINK_BLOCKED: all frames transmitted from this mesh plink are discarded
  */
 enum plink_state {
 	PLINK_LISTEN,
 	PLINK_OPN_SNT,
 	PLINK_OPN_RCVD,
 	PLINK_CNF_RCVD,
 	PLINK_ESTAB,
 	PLINK_HOLDING,
 	PLINK_BLOCKED
 };

 /**
  * struct sta_info - STA information
  *
  * This structure collects information about a station that
  * mac80211 is communicating with.
  *
  * @list: global linked list entry
  * @hnext: hash table linked list pointer
  * @local: pointer to the global information
  * @sdata: virtual interface this station belongs to
  * @ptk: peer key negotiated with this station, if any
  * @gtk: group keys negotiated with this station, if any
  * @rate_ctrl: rate control algorithm reference
  * @rate_ctrl_priv: rate control private per-STA pointer
  * @last_tx_rate: rate used for last transmit, to report to userspace as
  *	"the" transmit rate
  * @last_rx_rate_idx: rx status rate index of the last data packet
  * @last_rx_rate_flag: rx status flag of the last data packet
  * @lock: used for locking all fields that require locking, see comments
  *	in the header file.
  * @flaglock: spinlock for flags accesses
  * @drv_unblock_wk: used for driver PS unblocking
  * @listen_interval: listen interval of this station, when we're acting as AP
  * @flags: STA flags, see &enum ieee80211_sta_info_flags
  * @ps_tx_buf: buffer of frames to transmit to this station
  *	when it leaves power saving state
  * @tx_filtered: buffer of frames we already tried to transmit
  *	but were filtered by hardware due to STA having entered
  *	power saving state
  * @rx_packets: Number of MSDUs received from this STA
  * @rx_bytes: Number of bytes received from this STA
  * @wep_weak_iv_count: number of weak WEP IVs received from this station
  * @last_rx: time (in jiffies) when last frame was received from this STA
  * @num_duplicates: number of duplicate frames received from this STA
  * @rx_fragments: number of received MPDUs
  * @rx_dropped: number of dropped MPDUs from this STA
  * @last_signal: signal of last received frame from this STA
  * @avg_signal: moving average of signal of received frames from this STA
  * @last_seq_ctrl: last received seq/frag number from this STA (per RX queue)
  * @tx_filtered_count: number of frames the hardware filtered for this STA
  * @tx_retry_failed: number of frames that failed retry
  * @tx_retry_count: total number of retries for frames to this STA
  * @fail_avg: moving percentage of failed MSDUs
  * @tx_packets: number of RX/TX MSDUs
  * @tx_bytes: number of bytes transmitted to this STA
  * @tx_fragments: number of transmitted MPDUs
  * @tid_seq: per-TID sequence numbers for sending to this STA
  * @ampdu_mlme: A-MPDU state machine state
  * @timer_to_tid: identity mapping to ID timers
  * @llid: Local link ID
  * @plid: Peer link ID
  * @reason: Cancel reason on PLINK_HOLDING state
  * @plink_retries: Retries in establishment
  * @ignore_plink_timer: ignore the peer-link timer (used internally)
  * @plink_state: peer link state
  * @plink_timeout: timeout of peer link
  * @plink_timer: peer link watch timer
  * @plink_timer_was_running: used by suspend/resume to restore timers
  * @debugfs: debug filesystem info
  * @sta: station information we share with the driver
  * @dead: set to true when sta is unlinked
  * @uploaded: set to true when sta is uploaded to the driver
  * @lost_packets: number of consecutive lost packets
  */
 struct sta_info {
 	/* General information, mostly static */
 	struct list_head list;
 	struct sta_info *hnext;
 	struct ieee80211_local *local;
 	struct ieee80211_sub_if_data *sdata;
 	struct ieee80211_key *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
 	struct ieee80211_key *ptk;
 	struct rate_control_ref *rate_ctrl;
 	void *rate_ctrl_priv;
 	spinlock_t lock;
 	spinlock_t flaglock;

 	struct work_struct drv_unblock_wk;

 	u16 listen_interval;

 	bool dead;

 	bool uploaded;

 	/*
 	 * frequently updated, locked with own spinlock (flaglock),
 	 * use the accessors defined below
 	 */
 	u32 flags;

 	/*
 	 * STA powersave frame queues, no more than the internal
 	 * locking required.
 	 */
 	struct sk_buff_head ps_tx_buf;
 	struct sk_buff_head tx_filtered;

 	/* Updated from RX path only, no locking requirements */
 	unsigned long rx_packets, rx_bytes;
 	unsigned long wep_weak_iv_count;
 	unsigned long last_rx;
 	unsigned long num_duplicates;
 	unsigned long rx_fragments;
 	unsigned long rx_dropped;
 	int last_signal;
 	struct ewma avg_signal;
 	__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];

 	/* Updated from TX status path only, no locking requirements */
 	unsigned long tx_filtered_count;
 	unsigned long tx_retry_failed, tx_retry_count;
 	/* moving percentage of failed MSDUs */
 	unsigned int fail_avg;

 	/* Updated from TX path only, no locking requirements */
 	unsigned long tx_packets;
 	unsigned long tx_bytes;
 	unsigned long tx_fragments;
 	struct ieee80211_tx_rate last_tx_rate;
 	int last_rx_rate_idx;
 	int last_rx_rate_flag;
 	u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];

 	/*
 	 * Aggregation information, locked with lock.
 	 */
 	struct sta_ampdu_mlme ampdu_mlme;
 	u8 timer_to_tid[STA_TID_NUM];

 #ifdef CONFIG_MAC80211_MESH
 	/*
 	 * Mesh peer link attributes
 	 * TODO: move to a sub-structure that is referenced with pointer?
 	 */
 	__le16 llid;
 	__le16 plid;
 	__le16 reason;
 	u8 plink_retries;
 	bool ignore_plink_timer;
 	bool plink_timer_was_running;
 	enum plink_state plink_state;
 	u32 plink_timeout;
 	struct timer_list plink_timer;
 #endif

 #ifdef CONFIG_MAC80211_DEBUGFS
 	struct sta_info_debugfsdentries {
 		struct dentry *dir;
 		bool add_has_run;
 	} debugfs;
 #endif

 	unsigned int lost_packets;

 	/* keep last! */
 	struct ieee80211_sta sta;
 };

 static inline enum plink_state sta_plink_state(struct sta_info *sta)
 {
 #ifdef CONFIG_MAC80211_MESH
 	return sta->plink_state;
 #endif
 	return PLINK_LISTEN;
 }

 static inline void set_sta_flags(struct sta_info *sta, const u32 flags)
 {
 	unsigned long irqfl;

 	spin_lock_irqsave(&sta->flaglock, irqfl);
 	sta->flags |= flags;
 	spin_unlock_irqrestore(&sta->flaglock, irqfl);
 }

 static inline void clear_sta_flags(struct sta_info *sta, const u32 flags)
 {
 	unsigned long irqfl;

 	spin_lock_irqsave(&sta->flaglock, irqfl);
 	sta->flags &= ~flags;
 	spin_unlock_irqrestore(&sta->flaglock, irqfl);
 }

 static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
 {
 	u32 ret;
 	unsigned long irqfl;

 	spin_lock_irqsave(&sta->flaglock, irqfl);
 	ret = sta->flags & flags;
 	spin_unlock_irqrestore(&sta->flaglock, irqfl);

 	return ret;
 }

 static inline u32 test_and_clear_sta_flags(struct sta_info *sta,
 					   const u32 flags)
 {
 	u32 ret;
 	unsigned long irqfl;

 	spin_lock_irqsave(&sta->flaglock, irqfl);
 	ret = sta->flags & flags;
 	sta->flags &= ~flags;
 	spin_unlock_irqrestore(&sta->flaglock, irqfl);

 	return ret;
 }

 static inline u32 get_sta_flags(struct sta_info *sta)
 {
 	u32 ret;
 	unsigned long irqfl;

 	spin_lock_irqsave(&sta->flaglock, irqfl);
 	ret = sta->flags;
 	spin_unlock_irqrestore(&sta->flaglock, irqfl);

 	return ret;
 }


 #define STA_HASH_SIZE 256
 #define STA_HASH(sta) (sta[5])


 /* Maximum number of frames to buffer per power saving station */
 #define STA_MAX_TX_BUFFER 128

 /* Minimum buffered frame expiry time. If STA uses listen interval that is
  * smaller than this value, the minimum value here is used instead. */
 #define STA_TX_BUFFER_EXPIRE (10 * HZ)

 /* How often station data is cleaned up (e.g., expiration of buffered frames)
  */
 #define STA_INFO_CLEANUP_INTERVAL (10 * HZ)

 /*
  * Get a STA info, must be under RCU read lock.
  */
 struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
 			      const u8 *addr);

 struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
 				  const u8 *addr);

 static inline
 void for_each_sta_info_type_check(struct ieee80211_local *local,
 				  const u8 *addr,
 				  struct sta_info *sta,
 				  struct sta_info *nxt)
 {
 }

 #define for_each_sta_info(local, _addr, _sta, nxt) 			\
 	for (	/* initialise loop */					\
 		_sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
 		nxt = _sta ? rcu_dereference(_sta->hnext) : NULL;	\
 		/* typecheck */						\
 		for_each_sta_info_type_check(local, (_addr), _sta, nxt),\
 		/* continue condition */				\
 		_sta;							\
 		/* advance loop */					\
 		_sta = nxt,						\
 		nxt = _sta ? rcu_dereference(_sta->hnext) : NULL	\
 	     )								\
 	/* compare address and run code only if it matches */		\
 	if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0)

 /*
  * Get STA info by index, BROKEN!
  */
 struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
 				     int idx);
 /*
  * Create a new STA info, caller owns returned structure
  * until sta_info_insert().
  */
 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 				u8 *addr, gfp_t gfp);
 /*
  * Insert STA info into hash table/list, returns zero or a
  * -EEXIST if (if the same MAC address is already present).
  *
  * Calling the non-rcu version makes the caller relinquish,
  * the _rcu version calls read_lock_rcu() and must be called
  * without it held.
  */
 int sta_info_insert(struct sta_info *sta);
 int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
 int sta_info_insert_atomic(struct sta_info *sta);

 int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
 			  const u8 *addr);
 int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
 			      const u8 *addr);

 void sta_info_set_tim_bit(struct sta_info *sta);
 void sta_info_clear_tim_bit(struct sta_info *sta);

 void sta_info_init(struct ieee80211_local *local);
 int sta_info_start(struct ieee80211_local *local);
 void sta_info_stop(struct ieee80211_local *local);
 int sta_info_flush(struct ieee80211_local *local,
 		   struct ieee80211_sub_if_data *sdata);
 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
 			  unsigned long exp_time);

 void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta);
 void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta);

 #endif /* STA_INFO_H */
	/*
	* Copyright 2002-2005, Devicescape Software, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#ifndef STA_INFO_H
	#define STA_INFO_H

	#include <linux/list.h>
	#include <linux/types.h>
	#include <linux/if_ether.h>
	#include <linux/workqueue.h>
	#include <linux/average.h>
	#include "key.h"

	/**
	* enum ieee80211_sta_info_flags - Stations flags
	*
	* These flags are used with &struct sta_info's @flags member.
	*
	* @WLAN_STA_AUTH: Station is authenticated.
	* @WLAN_STA_ASSOC: Station is associated.
	* @WLAN_STA_PS_STA: Station is in power-save mode
	* @WLAN_STA_AUTHORIZED: Station is authorized to send/receive traffic.
	* This bit is always checked so needs to be enabled for all stations
	* when virtual port control is not in use.
	* @WLAN_STA_SHORT_PREAMBLE: Station is capable of receiving short-preamble
	* frames.
	* @WLAN_STA_ASSOC_AP: We're associated to that station, it is an AP.
	* @WLAN_STA_WME: Station is a QoS-STA.
	* @WLAN_STA_WDS: Station is one of our WDS peers.
	* @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
	* IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
	* frame to this station is transmitted.
	* @WLAN_STA_MFP: Management frame protection is used with this STA.
	* @WLAN_STA_BLOCK_BA: Used to deny ADDBA requests (both TX and RX)
	* during suspend/resume and station removal.
	* @WLAN_STA_PS_DRIVER: driver requires keeping this station in
	* power-save mode logically to flush frames that might still
	* be in the queues
	* @WLAN_STA_PSPOLL: Station sent PS-poll while driver was keeping
	* station in power-save mode, reply when the driver unblocks.
	*/
	enum ieee80211_sta_info_flags {
	WLAN_STA_AUTH = 1<<0,
	WLAN_STA_ASSOC = 1<<1,
	WLAN_STA_PS_STA = 1<<2,
	WLAN_STA_AUTHORIZED = 1<<3,
	WLAN_STA_SHORT_PREAMBLE = 1<<4,
	WLAN_STA_ASSOC_AP = 1<<5,
	WLAN_STA_WME = 1<<6,
	WLAN_STA_WDS = 1<<7,
	WLAN_STA_CLEAR_PS_FILT = 1<<9,
	WLAN_STA_MFP = 1<<10,
	WLAN_STA_BLOCK_BA = 1<<11,
	WLAN_STA_PS_DRIVER = 1<<12,
	WLAN_STA_PSPOLL = 1<<13,
	};

	#define STA_TID_NUM 16
	#define ADDBA_RESP_INTERVAL HZ
	#define HT_AGG_MAX_RETRIES 0x3

	#define HT_AGG_STATE_DRV_READY 0
	#define HT_AGG_STATE_RESPONSE_RECEIVED 1
	#define HT_AGG_STATE_OPERATIONAL 2
	#define HT_AGG_STATE_STOPPING 3
	#define HT_AGG_STATE_WANT_START 4
	#define HT_AGG_STATE_WANT_STOP 5

	/**
	* struct tid_ampdu_tx - TID aggregation information (Tx).
	*
	* @rcu_head: rcu head for freeing structure
	* @addba_resp_timer: timer for peer's response to addba request
	* @pending: pending frames queue -- use sta's spinlock to protect
	* @dialog_token: dialog token for aggregation session
	* @timeout: session timeout value to be filled in ADDBA requests
	* @state: session state (see above)
	* @stop_initiator: initiator of a session stop
	* @tx_stop: TX DelBA frame when stopping
	* @buf_size: reorder buffer size at receiver
	*
	* This structure's lifetime is managed by RCU, assignments to
	* the array holding it must hold the aggregation mutex.
	*
	* The TX path can access it under RCU lock-free if, and
	* only if, the state has the flag %HT_AGG_STATE_OPERATIONAL
	* set. Otherwise, the TX path must also acquire the spinlock
	* and re-check the state, see comments in the tx code
	* touching it.
	*/
	struct tid_ampdu_tx {
	struct rcu_head rcu_head;
	struct timer_list addba_resp_timer;
	struct sk_buff_head pending;
	unsigned long state;
	u16 timeout;
	u8 dialog_token;
	u8 stop_initiator;
	bool tx_stop;
	u8 buf_size;
	};

	/**
	* struct tid_ampdu_rx - TID aggregation information (Rx).
	*
	* @reorder_buf: buffer to reorder incoming aggregated MPDUs
	* @reorder_time: jiffies when skb was added
	* @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
	* @reorder_timer: releases expired frames from the reorder buffer.
	* @head_seq_num: head sequence number in reordering buffer.
	* @stored_mpdu_num: number of MPDUs in reordering buffer
	* @ssn: Starting Sequence Number expected to be aggregated.
	* @buf_size: buffer size for incoming A-MPDUs
	* @timeout: reset timer value (in TUs).
	* @dialog_token: dialog token for aggregation session
	* @rcu_head: RCU head used for freeing this struct
	* @reorder_lock: serializes access to reorder buffer, see below.
	*
	* This structure's lifetime is managed by RCU, assignments to
	* the array holding it must hold the aggregation mutex.
	*
	* The @reorder_lock is used to protect the members of this
	* struct, except for @timeout, @buf_size and @dialog_token,
	* which are constant across the lifetime of the struct (the
	* dialog token being used only for debugging).
	*/
	struct tid_ampdu_rx {
	struct rcu_head rcu_head;
	spinlock_t reorder_lock;
	struct sk_buff **reorder_buf;
	unsigned long *reorder_time;
	struct timer_list session_timer;
	struct timer_list reorder_timer;
	u16 head_seq_num;
	u16 stored_mpdu_num;
	u16 ssn;
	u16 buf_size;
	u16 timeout;
	u8 dialog_token;
	};

	/**
	* struct sta_ampdu_mlme - STA aggregation information.
	*
	* @tid_rx: aggregation info for Rx per TID -- RCU protected
	* @tid_tx: aggregation info for Tx per TID
	* @addba_req_num: number of times addBA request has been sent.
	* @dialog_token_allocator: dialog token enumerator for each new session;
	* @work: work struct for starting/stopping aggregation
	* @tid_rx_timer_expired: bitmap indicating on which TIDs the
	* RX timer expired until the work for it runs
	* @mtx: mutex to protect all TX data (except non-NULL assignments
	* to tid_tx[idx], which are protected by the sta spinlock)
	*/
	struct sta_ampdu_mlme {
	struct mutex mtx;
	/* rx */
	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
	unsigned long tid_rx_timer_expired[BITS_TO_LONGS(STA_TID_NUM)];
	/* tx */
	struct work_struct work;
	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
	u8 addba_req_num[STA_TID_NUM];
	u8 dialog_token_allocator;
	};


	/**
	* enum plink_state - state of a mesh peer link finite state machine
	*
	* @PLINK_LISTEN: initial state, considered the implicit state of non existent
	* mesh peer links
	* @PLINK_OPN_SNT: mesh plink open frame has been sent to this mesh peer
	* @PLINK_OPN_RCVD: mesh plink open frame has been received from this mesh peer
	* @PLINK_CNF_RCVD: mesh plink confirm frame has been received from this mesh
	* peer
	* @PLINK_ESTAB: mesh peer link is established
	* @PLINK_HOLDING: mesh peer link is being closed or cancelled
	* @PLINK_BLOCKED: all frames transmitted from this mesh plink are discarded
	*/
	enum plink_state {
	PLINK_LISTEN,
	PLINK_OPN_SNT,
	PLINK_OPN_RCVD,
	PLINK_CNF_RCVD,
	PLINK_ESTAB,
	PLINK_HOLDING,
	PLINK_BLOCKED
	};

	/**
	* struct sta_info - STA information
	*
	* This structure collects information about a station that
	* mac80211 is communicating with.
	*
	* @list: global linked list entry
	* @hnext: hash table linked list pointer
	* @local: pointer to the global information
	* @sdata: virtual interface this station belongs to
	* @ptk: peer key negotiated with this station, if any
	* @gtk: group keys negotiated with this station, if any
	* @rate_ctrl: rate control algorithm reference
	* @rate_ctrl_priv: rate control private per-STA pointer
	* @last_tx_rate: rate used for last transmit, to report to userspace as
	* "the" transmit rate
	* @last_rx_rate_idx: rx status rate index of the last data packet
	* @last_rx_rate_flag: rx status flag of the last data packet
	* @lock: used for locking all fields that require locking, see comments
	* in the header file.
	* @flaglock: spinlock for flags accesses
	* @drv_unblock_wk: used for driver PS unblocking
	* @listen_interval: listen interval of this station, when we're acting as AP
	* @flags: STA flags, see &enum ieee80211_sta_info_flags
	* @ps_tx_buf: buffer of frames to transmit to this station
	* when it leaves power saving state
	* @tx_filtered: buffer of frames we already tried to transmit
	* but were filtered by hardware due to STA having entered
	* power saving state
	* @rx_packets: Number of MSDUs received from this STA
	* @rx_bytes: Number of bytes received from this STA
	* @wep_weak_iv_count: number of weak WEP IVs received from this station
	* @last_rx: time (in jiffies) when last frame was received from this STA
	* @num_duplicates: number of duplicate frames received from this STA
	* @rx_fragments: number of received MPDUs
	* @rx_dropped: number of dropped MPDUs from this STA
	* @last_signal: signal of last received frame from this STA
	* @avg_signal: moving average of signal of received frames from this STA
	* @last_seq_ctrl: last received seq/frag number from this STA (per RX queue)
	* @tx_filtered_count: number of frames the hardware filtered for this STA
	* @tx_retry_failed: number of frames that failed retry
	* @tx_retry_count: total number of retries for frames to this STA
	* @fail_avg: moving percentage of failed MSDUs
	* @tx_packets: number of RX/TX MSDUs
	* @tx_bytes: number of bytes transmitted to this STA
	* @tx_fragments: number of transmitted MPDUs
	* @tid_seq: per-TID sequence numbers for sending to this STA
	* @ampdu_mlme: A-MPDU state machine state
	* @timer_to_tid: identity mapping to ID timers
	* @llid: Local link ID
	* @plid: Peer link ID
	* @reason: Cancel reason on PLINK_HOLDING state
	* @plink_retries: Retries in establishment
	* @ignore_plink_timer: ignore the peer-link timer (used internally)
	* @plink_state: peer link state
	* @plink_timeout: timeout of peer link
	* @plink_timer: peer link watch timer
	* @plink_timer_was_running: used by suspend/resume to restore timers
	* @debugfs: debug filesystem info
	* @sta: station information we share with the driver
	* @dead: set to true when sta is unlinked
	* @uploaded: set to true when sta is uploaded to the driver
	* @lost_packets: number of consecutive lost packets
	*/
	struct sta_info {
	/* General information, mostly static */
	struct list_head list;
	struct sta_info *hnext;
	struct ieee80211_local *local;
	struct ieee80211_sub_if_data *sdata;
	struct ieee80211_key *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
	struct ieee80211_key *ptk;
	struct rate_control_ref *rate_ctrl;
	void *rate_ctrl_priv;
	spinlock_t lock;
	spinlock_t flaglock;

	struct work_struct drv_unblock_wk;

	u16 listen_interval;

	bool dead;

	bool uploaded;

	/*
	* frequently updated, locked with own spinlock (flaglock),
	* use the accessors defined below
	*/
	u32 flags;

	/*
	* STA powersave frame queues, no more than the internal
	* locking required.
	*/
	struct sk_buff_head ps_tx_buf;
	struct sk_buff_head tx_filtered;

	/* Updated from RX path only, no locking requirements */
	unsigned long rx_packets, rx_bytes;
	unsigned long wep_weak_iv_count;
	unsigned long last_rx;
	unsigned long num_duplicates;
	unsigned long rx_fragments;
	unsigned long rx_dropped;
	int last_signal;
	struct ewma avg_signal;
	__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];

	/* Updated from TX status path only, no locking requirements */
	unsigned long tx_filtered_count;
	unsigned long tx_retry_failed, tx_retry_count;
	/* moving percentage of failed MSDUs */
	unsigned int fail_avg;

	/* Updated from TX path only, no locking requirements */
	unsigned long tx_packets;
	unsigned long tx_bytes;
	unsigned long tx_fragments;
	struct ieee80211_tx_rate last_tx_rate;
	int last_rx_rate_idx;
	int last_rx_rate_flag;
	u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];

	/*
	* Aggregation information, locked with lock.
	*/
	struct sta_ampdu_mlme ampdu_mlme;
	u8 timer_to_tid[STA_TID_NUM];

	#ifdef CONFIG_MAC80211_MESH
	/*
	* Mesh peer link attributes
	* TODO: move to a sub-structure that is referenced with pointer?
	*/
	__le16 llid;
	__le16 plid;
	__le16 reason;
	u8 plink_retries;
	bool ignore_plink_timer;
	bool plink_timer_was_running;
	enum plink_state plink_state;
	u32 plink_timeout;
	struct timer_list plink_timer;
	#endif

	#ifdef CONFIG_MAC80211_DEBUGFS
	struct sta_info_debugfsdentries {
	struct dentry *dir;
	bool add_has_run;
	} debugfs;
	#endif

	unsigned int lost_packets;

	/* keep last! */
	struct ieee80211_sta sta;
	};

	static inline enum plink_state sta_plink_state(struct sta_info *sta)
	{
	#ifdef CONFIG_MAC80211_MESH
	return sta->plink_state;
	#endif
	return PLINK_LISTEN;
	}

	static inline void set_sta_flags(struct sta_info *sta, const u32 flags)
	{
	unsigned long irqfl;

	spin_lock_irqsave(&sta->flaglock, irqfl);
	sta->flags \|= flags;
	spin_unlock_irqrestore(&sta->flaglock, irqfl);
	}

	static inline void clear_sta_flags(struct sta_info *sta, const u32 flags)
	{
	unsigned long irqfl;

	spin_lock_irqsave(&sta->flaglock, irqfl);
	sta->flags &= ~flags;
	spin_unlock_irqrestore(&sta->flaglock, irqfl);
	}

	static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
	{
	u32 ret;
	unsigned long irqfl;

	spin_lock_irqsave(&sta->flaglock, irqfl);
	ret = sta->flags & flags;
	spin_unlock_irqrestore(&sta->flaglock, irqfl);

	return ret;
	}

	static inline u32 test_and_clear_sta_flags(struct sta_info *sta,
	const u32 flags)
	{
	u32 ret;
	unsigned long irqfl;

	spin_lock_irqsave(&sta->flaglock, irqfl);
	ret = sta->flags & flags;
	sta->flags &= ~flags;
	spin_unlock_irqrestore(&sta->flaglock, irqfl);

	return ret;
	}

	static inline u32 get_sta_flags(struct sta_info *sta)
	{
	u32 ret;
	unsigned long irqfl;

	spin_lock_irqsave(&sta->flaglock, irqfl);
	ret = sta->flags;
	spin_unlock_irqrestore(&sta->flaglock, irqfl);

	return ret;
	}



	#define STA_HASH_SIZE 256
	#define STA_HASH(sta) (sta[5])


	/* Maximum number of frames to buffer per power saving station */
	#define STA_MAX_TX_BUFFER 128

	/* Minimum buffered frame expiry time. If STA uses listen interval that is
	* smaller than this value, the minimum value here is used instead. */
	#define STA_TX_BUFFER_EXPIRE (10 * HZ)

	/* How often station data is cleaned up (e.g., expiration of buffered frames)
	*/
	#define STA_INFO_CLEANUP_INTERVAL (10 * HZ)

	/*
	* Get a STA info, must be under RCU read lock.
	*/
	struct sta_info sta_info_get(struct ieee80211_sub_if_data sdata,
	const u8 *addr);

	struct sta_info sta_info_get_bss(struct ieee80211_sub_if_data sdata,
	const u8 *addr);

	static inline
	void for_each_sta_info_type_check(struct ieee80211_local *local,
	const u8 *addr,
	struct sta_info *sta,
	struct sta_info *nxt)
	{
	}

	#define for_each_sta_info(local, _addr, _sta, nxt) \
	for ( /* initialise loop */ \
	_sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
	nxt = _sta ? rcu_dereference(_sta->hnext) : NULL; \
	/* typecheck */ \
	for_each_sta_info_type_check(local, (_addr), _sta, nxt),\
	/* continue condition */ \
	_sta; \
	/* advance loop */ \
	_sta = nxt, \
	nxt = _sta ? rcu_dereference(_sta->hnext) : NULL \
	) \
	/* compare address and run code only if it matches */ \
	if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0)

	/*
	* Get STA info by index, BROKEN!
	*/
	struct sta_info sta_info_get_by_idx(struct ieee80211_sub_if_data sdata,
	int idx);
	/*
	* Create a new STA info, caller owns returned structure
	* until sta_info_insert().
	*/
	struct sta_info sta_info_alloc(struct ieee80211_sub_if_data sdata,
	u8 *addr, gfp_t gfp);
	/*
	* Insert STA info into hash table/list, returns zero or a
	* -EEXIST if (if the same MAC address is already present).
	*
	* Calling the non-rcu version makes the caller relinquish,
	* the _rcu version calls read_lock_rcu() and must be called
	* without it held.
	*/
	int sta_info_insert(struct sta_info *sta);
	int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
	int sta_info_insert_atomic(struct sta_info *sta);

	int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
	const u8 *addr);
	int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
	const u8 *addr);

	void sta_info_set_tim_bit(struct sta_info *sta);
	void sta_info_clear_tim_bit(struct sta_info *sta);

	void sta_info_init(struct ieee80211_local *local);
	int sta_info_start(struct ieee80211_local *local);
	void sta_info_stop(struct ieee80211_local *local);
	int sta_info_flush(struct ieee80211_local *local,
	struct ieee80211_sub_if_data *sdata);
	void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
	unsigned long exp_time);

	void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta);
	void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta);

	#endif /* STA_INFO_H */