/*
 * 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 "ieee80211_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: 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_PSPOLL: Station has just PS-polled us.
 * @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
 *	IEEE80211_TXCTL_CLEAR_PS_FILT control flag) when the next
 *	frame to this station is transmitted.
 */
enum ieee80211_sta_info_flags {
	WLAN_STA_AUTH		= 1<<0,
	WLAN_STA_ASSOC		= 1<<1,
	WLAN_STA_PS		= 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_PSPOLL		= 1<<8,
	WLAN_STA_CLEAR_PS_FILT	= 1<<9,
};

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

#define HT_AGG_STATE_INITIATOR_SHIFT	(4)

#define HT_ADDBA_REQUESTED_MSK		BIT(0)
#define HT_ADDBA_DRV_READY_MSK		BIT(1)
#define HT_ADDBA_RECEIVED_MSK		BIT(2)
#define HT_AGG_STATE_REQ_STOP_BA_MSK	BIT(3)
#define HT_AGG_STATE_INITIATOR_MSK      BIT(HT_AGG_STATE_INITIATOR_SHIFT)
#define HT_AGG_STATE_IDLE		(0x0)
#define HT_AGG_STATE_OPERATIONAL	(HT_ADDBA_REQUESTED_MSK |	\
					 HT_ADDBA_DRV_READY_MSK |	\
					 HT_ADDBA_RECEIVED_MSK)
#define HT_AGG_STATE_DEBUGFS_CTL	BIT(7)

/**
 * struct tid_ampdu_tx - TID aggregation information (Tx).
 *
 * @addba_resp_timer: timer for peer's response to addba request
 * @ssn: Starting Sequence Number expected to be aggregated.
 * @dialog_token: dialog token for aggregation session
 */
struct tid_ampdu_tx {
	struct timer_list addba_resp_timer;
	u16 ssn;
	u8 dialog_token;
};

/**
 * struct tid_ampdu_rx - TID aggregation information (Rx).
 *
 * @head_seq_num: head sequence number in reordering buffer.
 * @stored_mpdu_num: number of MPDUs in reordering buffer
 * @reorder_buf: buffer to reorder incoming aggregated MPDUs
 * @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
 * @ssn: Starting Sequence Number expected to be aggregated.
 * @buf_size: buffer size for incoming A-MPDUs
 * @timeout: reset timer value.
 * @dialog_token: dialog token for aggregation session
 */
struct tid_ampdu_rx {
	u16 head_seq_num;
	u16 stored_mpdu_num;
	struct sk_buff **reorder_buf;
	struct timer_list session_timer;
	u16 ssn;
	u16 buf_size;
	u16 timeout;
	u8 dialog_token;
};

/**
 * enum plink_state - state of a mesh peer link finite state machine
 *
 * @PLINK_LISTEN: initial state, considered the implicit state of non existant
 * 	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_ampdu_mlme - STA aggregation information.
 *
 * @tid_state_rx: TID's state in Rx session state machine.
 * @tid_rx: aggregation info for Rx per TID
 * @ampdu_rx: for locking sections in aggregation Rx flow
 * @tid_state_tx: TID's state in Tx session state machine.
 * @tid_tx: aggregation info for Tx per TID
 * @addba_req_num: number of times addBA request has been sent.
 * @ampdu_tx: for locking sectionsi in aggregation Tx flow
 * @dialog_token_allocator: dialog token enumerator for each new session;
 */
struct sta_ampdu_mlme {
	/* rx */
	u8 tid_state_rx[STA_TID_NUM];
	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
	spinlock_t ampdu_rx;
	/* tx */
	u8 tid_state_tx[STA_TID_NUM];
	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
	u8 addba_req_num[STA_TID_NUM];
	spinlock_t ampdu_tx;
	u8 dialog_token_allocator;
};


/* see __sta_info_unlink */
#define STA_INFO_PIN_STAT_NORMAL	0
#define STA_INFO_PIN_STAT_PINNED	1
#define STA_INFO_PIN_STAT_DESTROY	2

/**
 * 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
 * @addr: MAC address of this STA
 * @aid: STA's unique AID (1..2007, 0 = not assigned yet),
 *	only used in AP (and IBSS?) mode
 * @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
 * @supp_rates: Bitmap of supported rates (per band)
 * @ht_info: HT capabilities of this STA
 */
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 *key;
	struct rate_control_ref *rate_ctrl;
	void *rate_ctrl_priv;
	struct ieee80211_ht_info ht_info;
	u64 supp_rates[IEEE80211_NUM_BANDS];
	u8 addr[ETH_ALEN];
	u16 aid;
	u16 listen_interval;

	/*
	 * for use by the internal lifetime management,
	 * see __sta_info_unlink
	 */
	u8 pin_status;

	/* frequently updated information, needs locking? */
	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; /* number of duplicate frames received
				       * from this STA */
	unsigned long rx_fragments; /* number of received MPDUs */
	unsigned long rx_dropped; /* number of dropped MPDUs from this STA */
	int last_rssi; /* RSSI of last received frame from this STA */
	int last_signal; /* signal of last received frame from this STA */
	int last_noise; /* noise of last received frame from this STA */
	/* last received seq/frag number from this STA (per RX queue) */
	__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
	unsigned int wme_rx_queue[NUM_RX_DATA_QUEUES];
#endif

	/* Updated from TX status path only, no locking requirements */
	unsigned long tx_filtered_count;
	unsigned long tx_retry_failed, tx_retry_count;
	/* TODO: update in generic code not rate control? */
	u32 tx_num_consecutive_failures;
	u32 tx_num_mpdu_ok;
	u32 tx_num_mpdu_fail;
	/* moving percentage of failed MSDUs */
	unsigned int fail_avg;

	/* Updated from TX path only, no locking requirements */
	unsigned long tx_packets; /* number of RX/TX MSDUs */
	unsigned long tx_bytes;
	unsigned long tx_fragments; /* number of transmitted MPDUs */
	int txrate_idx;
	int last_txrate_idx;
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
	unsigned int wme_tx_queue[NUM_RX_DATA_QUEUES];
#endif

	/* Debug counters, no locking doesn't matter */
	int channel_use;
	int channel_use_raw;

	/*
	 * Aggregation information, comes with own locking.
	 */
	struct sta_ampdu_mlme ampdu_mlme;
	u8 timer_to_tid[STA_TID_NUM];	/* identity mapping to ID timers */
	u8 tid_to_tx_q[STA_TID_NUM];	/* map tid to tx queue */

#ifdef CONFIG_MAC80211_MESH
	/*
	 * Mesh peer link attributes
	 * TODO: move to a sub-structure that is referenced with pointer?
	 */
	__le16 llid;		/* Local link ID */
	__le16 plid;		/* Peer link ID */
	__le16 reason;		/* Cancel reason on PLINK_HOLDING state */
	u8 plink_retries;	/* Retries in establishment */
	bool ignore_plink_timer;
	enum plink_state plink_state;
	u32 plink_timeout;
	struct timer_list plink_timer;
	spinlock_t plink_lock;	/* For peer_state reads / updates and other
				   updates in the structure. Ensures robust
				   transitions for the peerlink FSM */
#endif

#ifdef CONFIG_MAC80211_DEBUGFS
	struct sta_info_debugfsdentries {
		struct dentry *dir;
		struct dentry *flags;
		struct dentry *num_ps_buf_frames;
		struct dentry *inactive_ms;
		struct dentry *last_seq_ctrl;
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
		struct dentry *wme_rx_queue;
		struct dentry *wme_tx_queue;
#endif
		struct dentry *agg_status;
	} debugfs;
#endif
};

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


/* Maximum number of concurrently registered stations */
#define MAX_STA_COUNT 2007

#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 have be under RCU read lock.
 */
struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr);
/*
 * Get STA info by index, BROKEN!
 */
struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx,
				      struct net_device *dev);
/*
 * 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 this without RCU protection makes the caller
 * relinquish its reference to @sta.
 */
int sta_info_insert(struct sta_info *sta);
/*
 * Unlink a STA info from the hash table/list.
 * This can NULL the STA pointer if somebody else
 * has already unlinked it.
 */
void sta_info_unlink(struct sta_info **sta);

void sta_info_destroy(struct sta_info *sta);
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);

#endif /* STA_INFO_H */