/*
   * 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, but
   * only indirectly with set_sta_flag() and friends.

   *
   * @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_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.

   * @WLAN_STA_TDLS_PEER: Station is a TDLS peer.
   * @WLAN_STA_TDLS_PEER_AUTH: This TDLS peer is authorized to send direct
   *	packets. This means the link is enabled.

   * @WLAN_STA_UAPSD: Station requested unscheduled SP while driver was
   *	keeping station in power-save mode, reply when the driver
   *	unblocks the station.
   * @WLAN_STA_SP: Station is in a service period, so don't try to

   *	reply to other uAPSD trigger frames or PS-Poll.

   * @WLAN_STA_4ADDR_EVENT: 4-addr event was already sent for this frame.

   */
  enum ieee80211_sta_info_flags {

  	WLAN_STA_AUTH,
  	WLAN_STA_ASSOC,
  	WLAN_STA_PS_STA,
  	WLAN_STA_AUTHORIZED,
  	WLAN_STA_SHORT_PREAMBLE,

  	WLAN_STA_WME,
  	WLAN_STA_WDS,
  	WLAN_STA_CLEAR_PS_FILT,
  	WLAN_STA_MFP,
  	WLAN_STA_BLOCK_BA,
  	WLAN_STA_PS_DRIVER,
  	WLAN_STA_PSPOLL,
  	WLAN_STA_TDLS_PEER,
  	WLAN_STA_TDLS_PEER_AUTH,
  	WLAN_STA_UAPSD,
  	WLAN_STA_SP,

  	WLAN_STA_4ADDR_EVENT,

  };

  enum ieee80211_sta_state {
  	/* NOTE: These need to be ordered correctly! */
  	IEEE80211_STA_NONE,
  	IEEE80211_STA_AUTH,
  	IEEE80211_STA_ASSOC,
  	IEEE80211_STA_AUTHORIZED,
  };

  #define STA_TID_NUM 16
  #define ADDBA_RESP_INTERVAL HZ

  #define HT_AGG_MAX_RETRIES		15
  #define HT_AGG_BURST_RETRIES		3
  #define HT_AGG_RETRIES_PERIOD		(15 * HZ)

  #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

   * @session_timer: check if we keep Tx-ing on the TID (by timeout value)

   * @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

   * @failed_bar_ssn: ssn of the last failed BAR tx attempt
   * @bar_pending: BAR needs to be re-sent

   *

   * 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 session_timer;

  	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;

  
  	u16 failed_bar_ssn;
  	bool bar_pending;

  };

  
  /**
   * 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

   * @tid_start_tx: sessions where start was requested

   * @addba_req_num: number of times addBA request has been sent.

   * @last_addba_req_time: timestamp of the last addBA request.

   * @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

   * @tid_rx_stop_requested:  bitmap indicating which BA sessions per TID the
   *	driver requested to close 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 __rcu *tid_rx[STA_TID_NUM];

  	unsigned long tid_rx_timer_expired[BITS_TO_LONGS(STA_TID_NUM)];

  	unsigned long tid_rx_stop_requested[BITS_TO_LONGS(STA_TID_NUM)];

  	/* tx */

  	struct work_struct work;

  	struct tid_ampdu_tx __rcu *tid_tx[STA_TID_NUM];

  	struct tid_ampdu_tx *tid_start_tx[STA_TID_NUM];

  	unsigned long last_addba_req_time[STA_TID_NUM];

  	u8 addba_req_num[STA_TID_NUM];
  	u8 dialog_token_allocator;
  };
  
  
  /**

   * 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.

   * @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, do not use directly

   * @ps_tx_buf: buffers (per AC) of frames to transmit to this station
   *	when it leaves power saving state or polls
   * @tx_filtered: buffers (per AC) of frames we already tried to
   *	transmit but were filtered by hardware due to STA having
   *	entered power saving state, these are also delivered to
   *	the station when it leaves powersave or polls for frames
   * @driver_buffered_tids: bitmap of TIDs the driver has data buffered on

   * @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

   * @last_connected: time (in seconds) when a station got connected

   * @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

   * @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

   * @dummy: indicate a dummy station created for receiving
   *	EAP frames before association
   * @sta: station information we share with the driver

   * @sta_state: duplicates information about station state (for debug)

   * @beacon_loss_count: number of times beacon loss has triggered

   */

  struct sta_info {

  	/* General information, mostly static */

  	struct list_head list;

  	struct sta_info __rcu *hnext;

  	struct ieee80211_local *local;

  	struct ieee80211_sub_if_data *sdata;

  	struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
  	struct ieee80211_key __rcu *ptk;

  	struct rate_control_ref *rate_ctrl;
  	void *rate_ctrl_priv;

  	spinlock_t lock;

  	struct work_struct drv_unblock_wk;

  	u16 listen_interval;

  	bool dead;

  	bool uploaded;

  	enum ieee80211_sta_state sta_state;

  	/* use the accessors defined below */
  	unsigned long _flags;

  
  	/*
  	 * STA powersave frame queues, no more than the internal
  	 * locking required.
  	 */

  	struct sk_buff_head ps_tx_buf[IEEE80211_NUM_ACS];
  	struct sk_buff_head tx_filtered[IEEE80211_NUM_ACS];
  	unsigned long driver_buffered_tids;

  
  	/* Updated from RX path only, no locking requirements */
  	unsigned long rx_packets, rx_bytes;
  	unsigned long wep_weak_iv_count;
  	unsigned long last_rx;

  	long last_connected;

  	unsigned long num_duplicates;
  	unsigned long rx_fragments;
  	unsigned long rx_dropped;
  	int last_signal;

  	struct ewma avg_signal;

  	/* Plus 1 for non-QoS frames */
  	__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES + 1];

  
  	/* 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 nl80211_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;

  	unsigned int beacon_loss_count;

  	/* should be right in front of sta to be in the same cache line */
  	bool dummy;

  	/* keep last! */
  	struct ieee80211_sta sta;

  };

  static inline enum nl80211_plink_state sta_plink_state(struct sta_info *sta)

  {
  #ifdef CONFIG_MAC80211_MESH
  	return sta->plink_state;
  #endif

  	return NL80211_PLINK_LISTEN;

  }

  static inline void set_sta_flag(struct sta_info *sta,
  				enum ieee80211_sta_info_flags flag)

  {

  	WARN_ON(flag == WLAN_STA_AUTH ||
  		flag == WLAN_STA_ASSOC ||
  		flag == WLAN_STA_AUTHORIZED);

  	set_bit(flag, &sta->_flags);

  }

  static inline void clear_sta_flag(struct sta_info *sta,
  				  enum ieee80211_sta_info_flags flag)

  {

  	WARN_ON(flag == WLAN_STA_AUTH ||
  		flag == WLAN_STA_ASSOC ||
  		flag == WLAN_STA_AUTHORIZED);

  	clear_bit(flag, &sta->_flags);

  }

  static inline int test_sta_flag(struct sta_info *sta,
  				enum ieee80211_sta_info_flags flag)

  {

  	return test_bit(flag, &sta->_flags);

  }

  static inline int test_and_clear_sta_flag(struct sta_info *sta,
  					  enum ieee80211_sta_info_flags flag)

  {

  	WARN_ON(flag == WLAN_STA_AUTH ||
  		flag == WLAN_STA_ASSOC ||
  		flag == WLAN_STA_AUTHORIZED);

  	return test_and_clear_bit(flag, &sta->_flags);

  }

  static inline int test_and_set_sta_flag(struct sta_info *sta,
  					enum ieee80211_sta_info_flags flag)
  {

  	WARN_ON(flag == WLAN_STA_AUTH ||
  		flag == WLAN_STA_ASSOC ||
  		flag == WLAN_STA_AUTHORIZED);

  	return test_and_set_bit(flag, &sta->_flags);
  }

  int sta_info_move_state_checked(struct sta_info *sta,
  				enum ieee80211_sta_state new_state);
  
  static inline void sta_info_move_state(struct sta_info *sta,
  				       enum ieee80211_sta_state new_state)
  {
  	int ret = sta_info_move_state_checked(sta, new_state);
  	WARN_ON_ONCE(ret);
  }

  void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
  			     struct tid_ampdu_tx *tid_tx);

  static inline struct tid_ampdu_tx *
  rcu_dereference_protected_tid_tx(struct sta_info *sta, int tid)
  {
  	return rcu_dereference_protected(sta->ampdu_mlme.tid_tx[tid],
  					 lockdep_is_held(&sta->lock) ||
  					 lockdep_is_held(&sta->ampdu_mlme.mtx));
  }

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

  /* Maximum number of frames to buffer per power saving station per AC */
  #define STA_MAX_TX_BUFFER	64

  
  /* 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_rx(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);

  struct sta_info *sta_info_get_bss_rx(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	\

  	     )								\

  	/* run code only if address matches and it's not a dummy sta */	\
  	if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0 &&		\
  		!_sta->dummy)
  
  #define for_each_sta_info_rx(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,

  				const u8 *addr, gfp_t gfp);

  
  void sta_info_free(struct ieee80211_local *local, struct sta_info *sta);

  /*
   * 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_reinsert(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_recalc_tim(struct sta_info *sta);

  void sta_info_init(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);

  void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta);

  #endif /* STA_INFO_H */