mac80211.h 67.5 KB
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/*
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 * mac80211 <-> driver interface
 *
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 * Copyright 2002-2005, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
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 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
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 *
 * 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 MAC80211_H
#define MAC80211_H

#include <linux/kernel.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/wireless.h>
#include <linux/device.h>
#include <linux/ieee80211.h>
#include <net/wireless.h>
#include <net/cfg80211.h>

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/**
 * DOC: Introduction
 *
 * mac80211 is the Linux stack for 802.11 hardware that implements
 * only partial functionality in hard- or firmware. This document
 * defines the interface between mac80211 and low-level hardware
 * drivers.
 */

/**
 * DOC: Calling mac80211 from interrupts
 *
 * Only ieee80211_tx_status_irqsafe() and ieee80211_rx_irqsafe() can be
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 * called in hardware interrupt context. The low-level driver must not call any
 * other functions in hardware interrupt context. If there is a need for such
 * call, the low-level driver should first ACK the interrupt and perform the
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 * IEEE 802.11 code call after this, e.g. from a scheduled workqueue or even
 * tasklet function.
 *
 * NOTE: If the driver opts to use the _irqsafe() functions, it may not also
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 *	 use the non-IRQ-safe functions!
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 */

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/**
 * DOC: Warning
 *
 * If you're reading this document and not the header file itself, it will
 * be incomplete because not all documentation has been converted yet.
 */

/**
 * DOC: Frame format
 *
 * As a general rule, when frames are passed between mac80211 and the driver,
 * they start with the IEEE 802.11 header and include the same octets that are
 * sent over the air except for the FCS which should be calculated by the
 * hardware.
 *
 * There are, however, various exceptions to this rule for advanced features:
 *
 * The first exception is for hardware encryption and decryption offload
 * where the IV/ICV may or may not be generated in hardware.
 *
 * Secondly, when the hardware handles fragmentation, the frame handed to
 * the driver from mac80211 is the MSDU, not the MPDU.
 *
 * Finally, for received frames, the driver is able to indicate that it has
 * filled a radiotap header and put that in front of the frame; if it does
 * not do so then mac80211 may add this under certain circumstances.
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 */

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/**
 * enum ieee80211_notification_type - Low level driver notification
 * @IEEE80211_NOTIFY_RE_ASSOC: start the re-association sequence
 */
enum ieee80211_notification_types {
	IEEE80211_NOTIFY_RE_ASSOC,
};

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/**
 * struct ieee80211_ht_bss_info - describing BSS's HT characteristics
 *
 * This structure describes most essential parameters needed
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 * to describe 802.11n HT characteristics in a BSS.
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 *
 * @primary_channel: channel number of primery channel
 * @bss_cap: 802.11n's general BSS capabilities (e.g. channel width)
 * @bss_op_mode: 802.11n's BSS operation modes (e.g. HT protection)
 */
struct ieee80211_ht_bss_info {
	u8 primary_channel;
	u8 bss_cap;  /* use IEEE80211_HT_IE_CHA_ */
	u8 bss_op_mode; /* use IEEE80211_HT_IE_ */
};

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/**
 * enum ieee80211_max_queues - maximum number of queues
 *
 * @IEEE80211_MAX_QUEUES: Maximum number of regular device queues.
 * @IEEE80211_MAX_AMPDU_QUEUES: Maximum number of queues usable
 *	for A-MPDU operation.
 */
enum ieee80211_max_queues {
	IEEE80211_MAX_QUEUES =		16,
	IEEE80211_MAX_AMPDU_QUEUES =	16,
};

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/**
 * struct ieee80211_tx_queue_params - transmit queue configuration
 *
 * The information provided in this structure is required for QoS
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 * transmit queue configuration. Cf. IEEE 802.11 7.3.2.29.
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 *
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 * @aifs: arbitration interface space [0..255]
 * @cw_min: minimum contention window [a value of the form
 *	2^n-1 in the range 1..32767]
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 * @cw_max: maximum contention window [like @cw_min]
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 * @txop: maximum burst time in units of 32 usecs, 0 meaning disabled
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 */
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struct ieee80211_tx_queue_params {
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	u16 txop;
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	u16 cw_min;
	u16 cw_max;
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	u8 aifs;
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};

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/**
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 * struct ieee80211_tx_queue_stats - transmit queue statistics
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 *
 * @len: number of packets in queue
 * @limit: queue length limit
 * @count: number of frames sent
 */
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struct ieee80211_tx_queue_stats {
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	unsigned int len;
	unsigned int limit;
	unsigned int count;
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};

struct ieee80211_low_level_stats {
	unsigned int dot11ACKFailureCount;
	unsigned int dot11RTSFailureCount;
	unsigned int dot11FCSErrorCount;
	unsigned int dot11RTSSuccessCount;
};

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/**
 * enum ieee80211_bss_change - BSS change notification flags
 *
 * These flags are used with the bss_info_changed() callback
 * to indicate which BSS parameter changed.
 *
 * @BSS_CHANGED_ASSOC: association status changed (associated/disassociated),
 *	also implies a change in the AID.
 * @BSS_CHANGED_ERP_CTS_PROT: CTS protection changed
 * @BSS_CHANGED_ERP_PREAMBLE: preamble changed
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 * @BSS_CHANGED_ERP_SLOT: slot timing changed
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 * @BSS_CHANGED_HT: 802.11n parameters changed
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 * @BSS_CHANGED_BASIC_RATES: Basic rateset changed
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 */
enum ieee80211_bss_change {
	BSS_CHANGED_ASSOC		= 1<<0,
	BSS_CHANGED_ERP_CTS_PROT	= 1<<1,
	BSS_CHANGED_ERP_PREAMBLE	= 1<<2,
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	BSS_CHANGED_ERP_SLOT		= 1<<3,
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	BSS_CHANGED_HT                  = 1<<4,
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	BSS_CHANGED_BASIC_RATES		= 1<<5,
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};

/**
 * struct ieee80211_bss_conf - holds the BSS's changing parameters
 *
 * This structure keeps information about a BSS (and an association
 * to that BSS) that can change during the lifetime of the BSS.
 *
 * @assoc: association status
 * @aid: association ID number, valid only when @assoc is true
 * @use_cts_prot: use CTS protection
 * @use_short_preamble: use 802.11b short preamble
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 * @use_short_slot: use short slot time (only relevant for ERP)
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 * @dtim_period: num of beacons before the next DTIM, for PSM
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 * @timestamp: beacon timestamp
 * @beacon_int: beacon interval
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 * @assoc_capability: capabilities taken from assoc resp
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 * @assoc_ht: association in HT mode
 * @ht_conf: ht capabilities
 * @ht_bss_conf: ht extended capabilities
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 * @basic_rates: bitmap of basic rates, each bit stands for an
 *	index into the rate table configured by the driver in
 *	the current band.
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 */
struct ieee80211_bss_conf {
	/* association related data */
	bool assoc;
	u16 aid;
	/* erp related data */
	bool use_cts_prot;
	bool use_short_preamble;
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	bool use_short_slot;
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	u8 dtim_period;
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	u16 beacon_int;
	u16 assoc_capability;
	u64 timestamp;
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	u64 basic_rates;
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	/* ht related data */
	bool assoc_ht;
	struct ieee80211_ht_info *ht_conf;
	struct ieee80211_ht_bss_info *ht_bss_conf;
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};

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/**
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 * enum mac80211_tx_control_flags - flags to describe transmission information/status
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 *
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 * These flags are used with the @flags member of &ieee80211_tx_info.
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 *
 * @IEEE80211_TX_CTL_REQ_TX_STATUS: request TX status callback for this frame.
 * @IEEE80211_TX_CTL_USE_RTS_CTS: use RTS-CTS before sending frame
 * @IEEE80211_TX_CTL_USE_CTS_PROTECT: use CTS protection for the frame (e.g.,
 *	for combined 802.11g / 802.11b networks)
 * @IEEE80211_TX_CTL_NO_ACK: tell the low level not to wait for an ack
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 * @IEEE80211_TX_CTL_RATE_CTRL_PROBE: TBD
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 * @IEEE80211_TX_CTL_CLEAR_PS_FILT: clear powersave filter for destination
 *	station
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 * @IEEE80211_TX_CTL_REQUEUE: TBD
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 * @IEEE80211_TX_CTL_FIRST_FRAGMENT: this is a first fragment of the frame
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 * @IEEE80211_TX_CTL_SHORT_PREAMBLE: TBD
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 * @IEEE80211_TX_CTL_LONG_RETRY_LIMIT: this frame should be send using the
 *	through set_retry_limit configured long retry value
 * @IEEE80211_TX_CTL_SEND_AFTER_DTIM: send this frame after DTIM beacon
 * @IEEE80211_TX_CTL_AMPDU: this frame should be sent as part of an A-MPDU
 * @IEEE80211_TX_CTL_OFDM_HT: this frame can be sent in HT OFDM rates. number
 *	of streams when this flag is on can be extracted from antenna_sel_tx,
 *	so if 1 antenna is marked use SISO, 2 antennas marked use MIMO, n
 *	antennas marked use MIMO_n.
 * @IEEE80211_TX_CTL_GREEN_FIELD: use green field protection for this frame
 * @IEEE80211_TX_CTL_40_MHZ_WIDTH: send this frame using 40 Mhz channel width
 * @IEEE80211_TX_CTL_DUP_DATA: duplicate data frame on both 20 Mhz channels
 * @IEEE80211_TX_CTL_SHORT_GI: send this frame using short guard interval
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 * @IEEE80211_TX_CTL_INJECTED: TBD
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 * @IEEE80211_TX_STAT_TX_FILTERED: The frame was not transmitted
 *	because the destination STA was in powersave mode.
 * @IEEE80211_TX_STAT_ACK: Frame was acknowledged
 * @IEEE80211_TX_STAT_AMPDU: The frame was aggregated, so status
 * 	is for the whole aggregation.
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 * @IEEE80211_TX_STAT_AMPDU_NO_BACK: no block ack was returned,
 * 	so consider using block ack request (BAR).
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 * @IEEE80211_TX_CTL_ASSIGN_SEQ: The driver has to assign a sequence
 *	number to this frame, taking care of not overwriting the fragment
 *	number and increasing the sequence number only when the
 *	IEEE80211_TX_CTL_FIRST_FRAGMENT flags is set. mac80211 will properly
 *	assign sequence numbers to QoS-data frames but cannot do so correctly
 *	for non-QoS-data and management frames because beacons need them from
 *	that counter as well and mac80211 cannot guarantee proper sequencing.
 *	If this flag is set, the driver should instruct the hardware to
 *	assign a sequence number to the frame or assign one itself. Cf. IEEE
 *	802.11-2007 7.1.3.4.1 paragraph 3. This flag will always be set for
 *	beacons always be clear for frames without a sequence number field.
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 */
enum mac80211_tx_control_flags {
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	IEEE80211_TX_CTL_REQ_TX_STATUS		= BIT(0),
	IEEE80211_TX_CTL_USE_RTS_CTS		= BIT(2),
	IEEE80211_TX_CTL_USE_CTS_PROTECT	= BIT(3),
	IEEE80211_TX_CTL_NO_ACK			= BIT(4),
	IEEE80211_TX_CTL_RATE_CTRL_PROBE	= BIT(5),
	IEEE80211_TX_CTL_CLEAR_PS_FILT		= BIT(6),
	IEEE80211_TX_CTL_REQUEUE		= BIT(7),
	IEEE80211_TX_CTL_FIRST_FRAGMENT		= BIT(8),
	IEEE80211_TX_CTL_SHORT_PREAMBLE		= BIT(9),
	IEEE80211_TX_CTL_LONG_RETRY_LIMIT	= BIT(10),
	IEEE80211_TX_CTL_SEND_AFTER_DTIM	= BIT(12),
	IEEE80211_TX_CTL_AMPDU			= BIT(13),
	IEEE80211_TX_CTL_OFDM_HT		= BIT(14),
	IEEE80211_TX_CTL_GREEN_FIELD		= BIT(15),
	IEEE80211_TX_CTL_40_MHZ_WIDTH		= BIT(16),
	IEEE80211_TX_CTL_DUP_DATA		= BIT(17),
	IEEE80211_TX_CTL_SHORT_GI		= BIT(18),
	IEEE80211_TX_CTL_INJECTED		= BIT(19),
	IEEE80211_TX_STAT_TX_FILTERED		= BIT(20),
	IEEE80211_TX_STAT_ACK			= BIT(21),
	IEEE80211_TX_STAT_AMPDU			= BIT(22),
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	IEEE80211_TX_STAT_AMPDU_NO_BACK		= BIT(23),
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	IEEE80211_TX_CTL_ASSIGN_SEQ		= BIT(24),
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};

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#define IEEE80211_TX_INFO_DRIVER_DATA_SIZE \
	(sizeof(((struct sk_buff *)0)->cb) - 8)
#define IEEE80211_TX_INFO_DRIVER_DATA_PTRS \
	(IEEE80211_TX_INFO_DRIVER_DATA_SIZE / sizeof(void *))
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/* maximum number of alternate rate retry stages */
#define IEEE80211_TX_MAX_ALTRATE	3

/**
 * struct ieee80211_tx_altrate - alternate rate selection/status
 *
 * @rate_idx: rate index to attempt to send with
 * @limit: number of retries before fallback
 */
struct ieee80211_tx_altrate {
	s8 rate_idx;
	u8 limit;
};

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/**
 * struct ieee80211_tx_info - skb transmit information
 *
 * This structure is placed in skb->cb for three uses:
 *  (1) mac80211 TX control - mac80211 tells the driver what to do
 *  (2) driver internal use (if applicable)
 *  (3) TX status information - driver tells mac80211 what happened
 *
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 * The TX control's sta pointer is only valid during the ->tx call,
 * it may be NULL.
 *
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 * @flags: transmit info flags, defined above
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 * @band: TBD
 * @tx_rate_idx: TBD
 * @antenna_sel_tx: TBD
 * @control: union for control data
 * @status: union for status data
 * @driver_data: array of driver_data pointers
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 * @retry_count: number of retries
 * @excessive_retries: set to 1 if the frame was retried many times
 *	but not acknowledged
 * @ampdu_ack_len: number of aggregated frames.
 * 	relevant only if IEEE80211_TX_STATUS_AMPDU was set.
 * @ampdu_ack_map: block ack bit map for the aggregation.
 * 	relevant only if IEEE80211_TX_STATUS_AMPDU was set.
 * @ack_signal: signal strength of the ACK frame
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 */
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struct ieee80211_tx_info {
	/* common information */
	u32 flags;
	u8 band;
	s8 tx_rate_idx;
	u8 antenna_sel_tx;
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	/* 1 byte hole */
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	union {
		struct {
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			/* NB: vif can be NULL for injected frames */
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			struct ieee80211_vif *vif;
			struct ieee80211_key_conf *hw_key;
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			struct ieee80211_sta *sta;
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			unsigned long jiffies;
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			s8 rts_cts_rate_idx;
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			u8 retry_limit;
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			struct ieee80211_tx_altrate retries[IEEE80211_TX_MAX_ALTRATE];
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		} control;
		struct {
			u64 ampdu_ack_map;
			int ack_signal;
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			struct ieee80211_tx_altrate retries[IEEE80211_TX_MAX_ALTRATE + 1];
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			u8 retry_count;
			bool excessive_retries;
			u8 ampdu_ack_len;
		} status;
		void *driver_data[IEEE80211_TX_INFO_DRIVER_DATA_PTRS];
	};
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};

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static inline struct ieee80211_tx_info *IEEE80211_SKB_CB(struct sk_buff *skb)
{
	return (struct ieee80211_tx_info *)skb->cb;
}
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/**
 * enum mac80211_rx_flags - receive flags
 *
 * These flags are used with the @flag member of &struct ieee80211_rx_status.
 * @RX_FLAG_MMIC_ERROR: Michael MIC error was reported on this frame.
 *	Use together with %RX_FLAG_MMIC_STRIPPED.
 * @RX_FLAG_DECRYPTED: This frame was decrypted in hardware.
 * @RX_FLAG_RADIOTAP: This frame starts with a radiotap header.
 * @RX_FLAG_MMIC_STRIPPED: the Michael MIC is stripped off this frame,
 *	verification has been done by the hardware.
 * @RX_FLAG_IV_STRIPPED: The IV/ICV are stripped from this frame.
 *	If this flag is set, the stack cannot do any replay detection
 *	hence the driver or hardware will have to do that.
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 * @RX_FLAG_FAILED_FCS_CRC: Set this flag if the FCS check failed on
 *	the frame.
 * @RX_FLAG_FAILED_PLCP_CRC: Set this flag if the PCLP check failed on
 *	the frame.
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 * @RX_FLAG_TSFT: The timestamp passed in the RX status (@mactime field)
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 *	is valid. This is useful in monitor mode and necessary for beacon frames
 *	to enable IBSS merging.
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 * @RX_FLAG_SHORTPRE: Short preamble was used for this frame
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 */
enum mac80211_rx_flags {
	RX_FLAG_MMIC_ERROR	= 1<<0,
	RX_FLAG_DECRYPTED	= 1<<1,
	RX_FLAG_RADIOTAP	= 1<<2,
	RX_FLAG_MMIC_STRIPPED	= 1<<3,
	RX_FLAG_IV_STRIPPED	= 1<<4,
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	RX_FLAG_FAILED_FCS_CRC	= 1<<5,
	RX_FLAG_FAILED_PLCP_CRC = 1<<6,
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	RX_FLAG_TSFT		= 1<<7,
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	RX_FLAG_SHORTPRE	= 1<<8
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};

/**
 * struct ieee80211_rx_status - receive status
 *
 * The low-level driver should provide this information (the subset
 * supported by hardware) to the 802.11 code with each received
 * frame.
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 *
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 * @mactime: value in microseconds of the 64-bit Time Synchronization Function
 * 	(TSF) timer when the first data symbol (MPDU) arrived at the hardware.
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 * @band: the active band when this frame was received
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 * @freq: frequency the radio was tuned to when receiving this frame, in MHz
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 * @signal: signal strength when receiving this frame, either in dBm, in dB or
 *	unspecified depending on the hardware capabilities flags
 *	@IEEE80211_HW_SIGNAL_*
 * @noise: noise when receiving this frame, in dBm.
 * @qual: overall signal quality indication, in percent (0-100).
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 * @antenna: antenna used
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 * @rate_idx: index of data rate into band's supported rates
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 * @flag: %RX_FLAG_*
 */
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struct ieee80211_rx_status {
	u64 mactime;
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	enum ieee80211_band band;
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	int freq;
	int signal;
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	int noise;
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	int qual;
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	int antenna;
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	int rate_idx;
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	int flag;
};

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/**
 * enum ieee80211_conf_flags - configuration flags
 *
 * Flags to define PHY configuration options
 *
 * @IEEE80211_CONF_SHORT_SLOT_TIME: use 802.11g short slot time
 * @IEEE80211_CONF_RADIOTAP: add radiotap header at receive time (if supported)
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 * @IEEE80211_CONF_SUPPORT_HT_MODE: use 802.11n HT capabilities (if supported)
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 * @IEEE80211_CONF_PS: Enable 802.11 power save mode
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 */
enum ieee80211_conf_flags {
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	/*
	 * TODO: IEEE80211_CONF_SHORT_SLOT_TIME will be removed once drivers
	 * have been converted to use bss_info_changed() for slot time
	 * configuration
	 */
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	IEEE80211_CONF_SHORT_SLOT_TIME	= (1<<0),
	IEEE80211_CONF_RADIOTAP		= (1<<1),
	IEEE80211_CONF_SUPPORT_HT_MODE	= (1<<2),
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	IEEE80211_CONF_PS		= (1<<3),
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};
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/**
 * struct ieee80211_conf - configuration of the device
 *
 * This struct indicates how the driver shall configure the hardware.
 *
 * @radio_enabled: when zero, driver is required to switch off the radio.
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 *	TODO make a flag
 * @beacon_int: beacon interval (TODO make interface config)
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 * @listen_interval: listen interval in units of beacon interval
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 * @flags: configuration flags defined above
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 * @power_level: requested transmit power (in dBm)
 * @max_antenna_gain: maximum antenna gain (in dBi)
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 * @antenna_sel_tx: transmit antenna selection, 0: default/diversity,
 *	1/2: antenna 0/1
 * @antenna_sel_rx: receive antenna selection, like @antenna_sel_tx
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 * @ht_conf: describes current self configuration of 802.11n HT capabilies
 * @ht_bss_conf: describes current BSS configuration of 802.11n HT parameters
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 * @channel: the channel to tune to
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 */
struct ieee80211_conf {
	int radio_enabled;

	int beacon_int;
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	u16 listen_interval;
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	u32 flags;
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	int power_level;
	int max_antenna_gain;
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	u8 antenna_sel_tx;
	u8 antenna_sel_rx;
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	struct ieee80211_channel *channel;

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	struct ieee80211_ht_info ht_conf;
	struct ieee80211_ht_bss_info ht_bss_conf;
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};

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/**
 * struct ieee80211_vif - per-interface data
 *
 * Data in this structure is continually present for driver
 * use during the life of a virtual interface.
 *
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 * @type: type of this virtual interface
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 * @drv_priv: data area for driver use, will always be aligned to
 *	sizeof(void *).
 */
struct ieee80211_vif {
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	enum nl80211_iftype type;
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	/* must be last */
	u8 drv_priv[0] __attribute__((__aligned__(sizeof(void *))));
};

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static inline bool ieee80211_vif_is_mesh(struct ieee80211_vif *vif)
{
#ifdef CONFIG_MAC80211_MESH
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	return vif->type == NL80211_IFTYPE_MESH_POINT;
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#endif
	return false;
}

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/**
 * struct ieee80211_if_init_conf - initial configuration of an interface
 *
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 * @vif: pointer to a driver-use per-interface structure. The pointer
 *	itself is also used for various functions including
 *	ieee80211_beacon_get() and ieee80211_get_buffered_bc().
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 * @type: one of &enum nl80211_iftype constants. Determines the type of
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 *	added/removed interface.
 * @mac_addr: pointer to MAC address of the interface. This pointer is valid
 *	until the interface is removed (i.e. it cannot be used after
 *	remove_interface() callback was called for this interface).
 *
 * This structure is used in add_interface() and remove_interface()
 * callbacks of &struct ieee80211_hw.
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 *
 * When you allow multiple interfaces to be added to your PHY, take care
 * that the hardware can actually handle multiple MAC addresses. However,
 * also take care that when there's no interface left with mac_addr != %NULL
 * you remove the MAC address from the device to avoid acknowledging packets
 * in pure monitor mode.
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 */
struct ieee80211_if_init_conf {
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	enum nl80211_iftype type;
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	struct ieee80211_vif *vif;
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	void *mac_addr;
};

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/**
 * enum ieee80211_if_conf_change - interface config change flags
 *
 * @IEEE80211_IFCC_BSSID: The BSSID changed.
 * @IEEE80211_IFCC_SSID: The SSID changed.
 * @IEEE80211_IFCC_BEACON: The beacon for this interface changed
 *	(currently AP and MESH only), use ieee80211_beacon_get().
 */
enum ieee80211_if_conf_change {
	IEEE80211_IFCC_BSSID	= BIT(0),
	IEEE80211_IFCC_SSID	= BIT(1),
	IEEE80211_IFCC_BEACON	= BIT(2),
};

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/**
 * struct ieee80211_if_conf - configuration of an interface
 *
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 * @changed: parameters that have changed, see &enum ieee80211_if_conf_change.
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 * @bssid: BSSID of the network we are associated to/creating.
 * @ssid: used (together with @ssid_len) by drivers for hardware that
 *	generate beacons independently. The pointer is valid only during the
 *	config_interface() call, so copy the value somewhere if you need
 *	it.
 * @ssid_len: length of the @ssid field.
 *
 * This structure is passed to the config_interface() callback of
 * &struct ieee80211_hw.
 */
struct ieee80211_if_conf {
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	u32 changed;
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	u8 *bssid;
	u8 *ssid;
	size_t ssid_len;
};

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/**
 * enum ieee80211_key_alg - key algorithm
 * @ALG_WEP: WEP40 or WEP104
 * @ALG_TKIP: TKIP
 * @ALG_CCMP: CCMP (AES)
 */
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enum ieee80211_key_alg {
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	ALG_WEP,
	ALG_TKIP,
	ALG_CCMP,
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};
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/**
 * enum ieee80211_key_len - key length
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 * @LEN_WEP40: WEP 5-byte long key
 * @LEN_WEP104: WEP 13-byte long key
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 */
enum ieee80211_key_len {
	LEN_WEP40 = 5,
	LEN_WEP104 = 13,
};
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/**
 * enum ieee80211_key_flags - key flags
 *
 * These flags are used for communication about keys between the driver
 * and mac80211, with the @flags parameter of &struct ieee80211_key_conf.
 *
 * @IEEE80211_KEY_FLAG_WMM_STA: Set by mac80211, this flag indicates
 *	that the STA this key will be used with could be using QoS.
 * @IEEE80211_KEY_FLAG_GENERATE_IV: This flag should be set by the
 *	driver to indicate that it requires IV generation for this
 *	particular key.
 * @IEEE80211_KEY_FLAG_GENERATE_MMIC: This flag should be set by
 *	the driver for a TKIP key if it requires Michael MIC
 *	generation in software.
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 * @IEEE80211_KEY_FLAG_PAIRWISE: Set by mac80211, this flag indicates
 *	that the key is pairwise rather then a shared key.
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 */
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enum ieee80211_key_flags {
	IEEE80211_KEY_FLAG_WMM_STA	= 1<<0,
	IEEE80211_KEY_FLAG_GENERATE_IV	= 1<<1,
	IEEE80211_KEY_FLAG_GENERATE_MMIC= 1<<2,
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	IEEE80211_KEY_FLAG_PAIRWISE	= 1<<3,
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};
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/**
 * struct ieee80211_key_conf - key information
 *
 * This key information is given by mac80211 to the driver by
 * the set_key() callback in &struct ieee80211_ops.
 *
 * @hw_key_idx: To be set by the driver, this is the key index the driver
 *	wants to be given when a frame is transmitted and needs to be
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 *	encrypted in hardware.
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 * @alg: The key algorithm.
 * @flags: key flags, see &enum ieee80211_key_flags.
 * @keyidx: the key index (0-3)
 * @keylen: key material length
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 * @key: key material. For ALG_TKIP the key is encoded as a 256-bit (32 byte)
 * 	data block:
 * 	- Temporal Encryption Key (128 bits)
 * 	- Temporal Authenticator Tx MIC Key (64 bits)
 * 	- Temporal Authenticator Rx MIC Key (64 bits)
 *
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 */
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struct ieee80211_key_conf {
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	enum ieee80211_key_alg alg;
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	u8 icv_len;
	u8 iv_len;
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	u8 hw_key_idx;
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	u8 flags;
	s8 keyidx;
	u8 keylen;
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	u8 key[0];
};

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/**
 * enum set_key_cmd - key command
 *
 * Used with the set_key() callback in &struct ieee80211_ops, this
 * indicates whether a key is being removed or added.
 *
 * @SET_KEY: a key is set
 * @DISABLE_KEY: a key must be disabled
 */
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enum set_key_cmd {
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	SET_KEY, DISABLE_KEY,
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};
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/**
 * struct ieee80211_sta - station table entry
 *
 * A station table entry represents a station we are possibly
 * communicating with. Since stations are RCU-managed in
 * mac80211, any ieee80211_sta pointer you get access to must
 * either be protected by rcu_read_lock() explicitly or implicitly,
 * or you must take good care to not use such a pointer after a
 * call to your sta_notify callback that removed it.
 *
 * @addr: MAC address
 * @aid: AID we assigned to the station if we're an AP
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 * @supp_rates: Bitmap of supported rates (per band)
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 * @ht_info: HT capabilities of this STA
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 * @drv_priv: data area for driver use, will always be aligned to
 *	sizeof(void *), size is determined in hw information.
 */
struct ieee80211_sta {
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	u64 supp_rates[IEEE80211_NUM_BANDS];
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	u8 addr[ETH_ALEN];
	u16 aid;
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	struct ieee80211_ht_info ht_info;
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	/* must be last */
	u8 drv_priv[0] __attribute__((__aligned__(sizeof(void *))));
};

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/**
 * enum sta_notify_cmd - sta notify command
 *
 * Used with the sta_notify() callback in &struct ieee80211_ops, this
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 * indicates addition and removal of a station to station table.
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 *
 * @STA_NOTIFY_ADD: a station was added to the station table
 * @STA_NOTIFY_REMOVE: a station being removed from the station table
 */
enum sta_notify_cmd {
	STA_NOTIFY_ADD, STA_NOTIFY_REMOVE
};
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/**
 * enum ieee80211_tkip_key_type - get tkip key
 *
 * Used by drivers which need to get a tkip key for skb. Some drivers need a
 * phase 1 key, others need a phase 2 key. A single function allows the driver
 * to get the key, this enum indicates what type of key is required.
 *
 * @IEEE80211_TKIP_P1_KEY: the driver needs a phase 1 key
 * @IEEE80211_TKIP_P2_KEY: the driver needs a phase 2 key
 */
enum ieee80211_tkip_key_type {
	IEEE80211_TKIP_P1_KEY,
	IEEE80211_TKIP_P2_KEY,
};

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/**
 * enum ieee80211_hw_flags - hardware flags
 *
 * These flags are used to indicate hardware capabilities to
 * the stack. Generally, flags here should have their meaning
 * done in a way that the simplest hardware doesn't need setting
 * any particular flags. There are some exceptions to this rule,
 * however, so you are advised to review these flags carefully.
 *
 * @IEEE80211_HW_RX_INCLUDES_FCS:
 *	Indicates that received frames passed to the stack include
 *	the FCS at the end.
 *
 * @IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING:
 *	Some wireless LAN chipsets buffer broadcast/multicast frames
 *	for power saving stations in the hardware/firmware and others
 *	rely on the host system for such buffering. This option is used
 *	to configure the IEEE 802.11 upper layer to buffer broadcast and
 *	multicast frames when there are power saving stations so that
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 *	the driver can fetch them with ieee80211_get_buffered_bc().
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 *
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 * @IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE:
 *	Hardware is not capable of short slot operation on the 2.4 GHz band.
 *
 * @IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE:
 *	Hardware is not capable of receiving frames with short preamble on
 *	the 2.4 GHz band.
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 *
 * @IEEE80211_HW_SIGNAL_UNSPEC:
 *	Hardware can provide signal values but we don't know its units. We
 *	expect values between 0 and @max_signal.
 *	If possible please provide dB or dBm instead.
 *
 * @IEEE80211_HW_SIGNAL_DB:
 *	Hardware gives signal values in dB, decibel difference from an
 *	arbitrary, fixed reference. We expect values between 0 and @max_signal.
 *	If possible please provide dBm instead.
 *
 * @IEEE80211_HW_SIGNAL_DBM:
 *	Hardware gives signal values in dBm, decibel difference from
 *	one milliwatt. This is the preferred method since it is standardized
 *	between different devices. @max_signal does not need to be set.
 *
 * @IEEE80211_HW_NOISE_DBM:
 *	Hardware can provide noise (radio interference) values in units dBm,
 *      decibel difference from one milliwatt.
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 *
 * @IEEE80211_HW_SPECTRUM_MGMT:
 * 	Hardware supports spectrum management defined in 802.11h
 * 	Measurement, Channel Switch, Quieting, TPC
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 */
enum ieee80211_hw_flags {
	IEEE80211_HW_RX_INCLUDES_FCS			= 1<<1,
	IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING	= 1<<2,
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	IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE		= 1<<3,
	IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE	= 1<<4,
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	IEEE80211_HW_SIGNAL_UNSPEC			= 1<<5,
	IEEE80211_HW_SIGNAL_DB				= 1<<6,
	IEEE80211_HW_SIGNAL_DBM				= 1<<7,
	IEEE80211_HW_NOISE_DBM				= 1<<8,
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	IEEE80211_HW_SPECTRUM_MGMT			= 1<<9,
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};

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/**
 * struct ieee80211_hw - hardware information and state
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 *
 * This structure contains the configuration and hardware
 * information for an 802.11 PHY.
 *
 * @wiphy: This points to the &struct wiphy allocated for this
 *	802.11 PHY. You must fill in the @perm_addr and @dev
 *	members of this structure using SET_IEEE80211_DEV()
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 *	and SET_IEEE80211_PERM_ADDR(). Additionally, all supported
 *	bands (with channels, bitrates) are registered here.
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 *
 * @conf: &struct ieee80211_conf, device configuration, don't use.
 *
 * @workqueue: single threaded workqueue available for driver use,
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 *	allocated by mac80211 on registration and flushed when an
 *	interface is removed.
 *	NOTICE: All work performed on this workqueue should NEVER
 *	acquire the RTNL lock (i.e. Don't use the function
 *	ieee80211_iterate_active_interfaces())
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 *
 * @priv: pointer to private area that was allocated for driver use
 *	along with this structure.
 *
 * @flags: hardware flags, see &enum ieee80211_hw_flags.
 *
 * @extra_tx_headroom: headroom to reserve in each transmit skb
 *	for use by the driver (e.g. for transmit headers.)
 *
 * @channel_change_time: time (in microseconds) it takes to change channels.
 *
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 * @max_signal: Maximum value for signal (rssi) in RX information, used
 *     only when @IEEE80211_HW_SIGNAL_UNSPEC or @IEEE80211_HW_SIGNAL_DB
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 *
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 * @max_listen_interval: max listen interval in units of beacon interval
 *     that HW supports
 *
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 * @queues: number of available hardware transmit queues for
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Johannes Berg committed
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 *	data packets. WMM/QoS requires at least four, these
 *	queues need to have configurable access parameters.
 *
 * @ampdu_queues: number of available hardware transmit queues
 *	for A-MPDU packets, these have no access parameters
 *	because they're used only for A-MPDU frames. Note that
 *	mac80211 will not currently use any of the regular queues
 *	for aggregation.
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 *
 * @rate_control_algorithm: rate control algorithm for this hardware.
 *	If unset (NULL), the default algorithm will be used. Must be
 *	set before calling ieee80211_register_hw().
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 *
 * @vif_data_size: size (in bytes) of the drv_priv data area
 *	within &struct ieee80211_vif.
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 * @sta_data_size: size (in bytes) of the drv_priv data area
 *	within &struct ieee80211_sta.
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 *
 * @max_altrates: maximum number of alternate rate retry stages
 * @max_altrate_tries: maximum number of tries for each stage
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 */
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struct ieee80211_hw {
	struct ieee80211_conf conf;
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	struct wiphy *wiphy;
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	struct workqueue_struct *workqueue;
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	const char *rate_control_algorithm;
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	void *priv;
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	u32 flags;
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	unsigned int extra_tx_headroom;
	int channel_change_time;
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	int vif_data_size;
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	int sta_data_size;
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	u16 queues;
	u16 ampdu_queues;
	u16 max_listen_interval;
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	s8 max_signal;
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	u8 max_altrates;
	u8 max_altrate_tries;
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};

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struct ieee80211_hw *wiphy_to_hw(struct wiphy *wiphy);

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/**
 * SET_IEEE80211_DEV - set device for 802.11 hardware
 *
 * @hw: the &struct ieee80211_hw to set the device for
 * @dev: the &struct device of this 802.11 device
 */
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static inline void SET_IEEE80211_DEV(struct ieee80211_hw *hw, struct device *dev)
{
	set_wiphy_dev(hw->wiphy, dev);
}

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/**
 * SET_IEEE80211_PERM_ADDR - set the permanenet MAC address for 802.11 hardware
 *
 * @hw: the &struct ieee80211_hw to set the MAC address for
 * @addr: the address to set
 */
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static inline void SET_IEEE80211_PERM_ADDR(struct ieee80211_hw *hw, u8 *addr)
{
	memcpy(hw->wiphy->perm_addr, addr, ETH_ALEN);
}

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static inline int ieee80211_num_regular_queues(struct ieee80211_hw *hw)
{
	return hw->queues;
}

static inline int ieee80211_num_queues(struct ieee80211_hw *hw)
{
	return hw->queues + hw->ampdu_queues;
}

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static inline struct ieee80211_rate *
ieee80211_get_tx_rate(const struct ieee80211_hw *hw,
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		      const struct ieee80211_tx_info *c)
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{
	if (WARN_ON(c->tx_rate_idx < 0))
		return NULL;
	return &hw->wiphy->bands[c->band]->bitrates[c->tx_rate_idx];
}

static inline struct ieee80211_rate *
ieee80211_get_rts_cts_rate(const struct ieee80211_hw *hw,
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			   const struct ieee80211_tx_info *c)
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{
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	if (c->control.rts_cts_rate_idx < 0)
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		return NULL;
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	return &hw->wiphy->bands[c->band]->bitrates[c->control.rts_cts_rate_idx];
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}

static inline struct ieee80211_rate *
ieee80211_get_alt_retry_rate(const struct ieee80211_hw *hw,
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			     const struct ieee80211_tx_info *c, int idx)
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{
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	if (c->control.retries[idx].rate_idx < 0)
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		return NULL;
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	return &hw->wiphy->bands[c->band]->bitrates[c->control.retries[idx].rate_idx];
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}

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/**
 * DOC: Hardware crypto acceleration
 *
 * mac80211 is capable of taking advantage of many hardware
 * acceleration designs for encryption and decryption operations.
 *
 * The set_key() callback in the &struct ieee80211_ops for a given
 * device is called to enable hardware acceleration of encryption and
 * decryption. The callback takes an @address parameter that will be
 * the broadcast address for default keys, the other station's hardware
 * address for individual keys or the zero address for keys that will
 * be used only for transmission.
 * Multiple transmission keys with the same key index may be used when
 * VLANs are configured for an access point.
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 *
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 * The @local_address parameter will always be set to our own address,
 * this is only relevant if you support multiple local addresses.
 *
 * When transmitting, the TX control data will use the @hw_key_idx
 * selected by the driver by modifying the &struct ieee80211_key_conf
 * pointed to by the @key parameter to the set_key() function.
 *
 * The set_key() call for the %SET_KEY command should return 0 if
 * the key is now in use, -%EOPNOTSUPP or -%ENOSPC if it couldn't be
 * added; if you return 0 then hw_key_idx must be assigned to the
 * hardware key index, you are free to use the full u8 range.
 *
 * When the cmd is %DISABLE_KEY then it must succeed.
 *
 * Note that it is permissible to not decrypt a frame even if a key
 * for it has been uploaded to hardware, the stack will not make any
 * decision based on whether a key has been uploaded or not but rather
 * based on the receive flags.
 *
 * The &struct ieee80211_key_conf structure pointed to by the @key
 * parameter is guaranteed to be valid until another call to set_key()
 * removes it, but it can only be used as a cookie to differentiate
 * keys.
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 *
 * In TKIP some HW need to be provided a phase 1 key, for RX decryption
 * acceleration (i.e. iwlwifi). Those drivers should provide update_tkip_key
 * handler.
 * The update_tkip_key() call updates the driver with the new phase 1 key.
 * This happens everytime the iv16 wraps around (every 65536 packets). The
 * set_key() call will happen only once for each key (unless the AP did
 * rekeying), it will not include a valid phase 1 key. The valid phase 1 key is
 * provided by udpate_tkip_key only. The trigger that makes mac80211 call this
 * handler is software decryption with wrap around of iv16.
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 */
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/**
 * DOC: Frame filtering
 *
 * mac80211 requires to see many management frames for proper
 * operation, and users may want to see many more frames when
 * in monitor mode. However, for best CPU usage and power consumption,
 * having as few frames as possible percolate through the stack is
 * desirable. Hence, the hardware should filter as much as possible.
 *
 * To achieve this, mac80211 uses filter flags (see below) to tell
 * the driver's configure_filter() function which frames should be
 * passed to mac80211 and which should be filtered out.
 *
 * The configure_filter() callback is invoked with the parameters
 * @mc_count and @mc_list for the combined multicast address list
 * of all virtual interfaces, @changed_flags telling which flags
 * were changed and @total_flags with the new flag states.
 *
 * If your device has no multicast address filters your driver will
 * need to check both the %FIF_ALLMULTI flag and the @mc_count
 * parameter to see whether multicast frames should be accepted
 * or dropped.
 *
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 * All unsupported flags in @total_flags must be cleared.
 * Hardware does not support a flag if it is incapable of _passing_
 * the frame to the stack. Otherwise the driver must ignore
 * the flag, but not clear it.
 * You must _only_ clear the flag (announce no support for the
 * flag to mac80211) if you are not able to pass the packet type
 * to the stack (so the hardware always filters it).
 * So for example, you should clear @FIF_CONTROL, if your hardware
 * always filters control frames. If your hardware always passes
 * control frames to the kernel and is incapable of filtering them,
 * you do _not_ clear the @FIF_CONTROL flag.
 * This rule applies to all other FIF flags as well.
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 */
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/**
 * enum ieee80211_filter_flags - hardware filter flags
 *
 * These flags determine what the filter in hardware should be
 * programmed to let through and what should not be passed to the
 * stack. It is always safe to pass more frames than requested,
 * but this has negative impact on power consumption.
 *
 * @FIF_PROMISC_IN_BSS: promiscuous mode within your BSS,
 *	think of the BSS as your network segment and then this corresponds
 *	to the regular ethernet device promiscuous mode.
 *
 * @FIF_ALLMULTI: pass all multicast frames, this is used if requested
 *	by the user or if the hardware is not capable of filtering by
 *	multicast address.
 *
 * @FIF_FCSFAIL: pass frames with failed FCS (but you need to set the
 *	%RX_FLAG_FAILED_FCS_CRC for them)
 *
 * @FIF_PLCPFAIL: pass frames with failed PLCP CRC (but you need to set
 *	the %RX_FLAG_FAILED_PLCP_CRC for them
 *
 * @FIF_BCN_PRBRESP_PROMISC: This flag is set during scanning to indicate
 *	to the hardware that it should not filter beacons or probe responses
 *	by BSSID. Filtering them can greatly reduce the amount of processing
 *	mac80211 needs to do and the amount of CPU wakeups, so you should
 *	honour this flag if possible.
 *
 * @FIF_CONTROL: pass control frames, if PROMISC_IN_BSS is not set then
 *	only those addressed to this station
 *
 * @FIF_OTHER_BSS: pass frames destined to other BSSes
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 */
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enum ieee80211_filter_flags {
	FIF_PROMISC_IN_BSS	= 1<<0,
	FIF_ALLMULTI		= 1<<1,
	FIF_FCSFAIL		= 1<<2,
	FIF_PLCPFAIL		= 1<<3,
	FIF_BCN_PRBRESP_PROMISC	= 1<<4,
	FIF_CONTROL		= 1<<5,
	FIF_OTHER_BSS		= 1<<6,
};

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/**
 * enum ieee80211_ampdu_mlme_action - A-MPDU actions
 *
 * These flags are used with the ampdu_action() callback in
 * &struct ieee80211_ops to indicate which action is needed.
 * @IEEE80211_AMPDU_RX_START: start Rx aggregation
 * @IEEE80211_AMPDU_RX_STOP: stop Rx aggregation
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 * @IEEE80211_AMPDU_TX_START: start Tx aggregation
 * @IEEE80211_AMPDU_TX_STOP: stop Tx aggregation
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 */
enum ieee80211_ampdu_mlme_action {
	IEEE80211_AMPDU_RX_START,
	IEEE80211_AMPDU_RX_STOP,
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	IEEE80211_AMPDU_TX_START,
	IEEE80211_AMPDU_TX_STOP,
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};
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/**
 * struct ieee80211_ops - callbacks from mac80211 to the driver
 *
 * This structure contains various callbacks that the driver may
 * handle or, in some cases, must handle, for example to configure
 * the hardware to a new channel or to transmit a frame.
 *
 * @tx: Handler that 802.11 module calls for each transmitted frame.
 *	skb contains the buffer starting from the IEEE 802.11 header.
 *	The low-level driver should send the frame out based on
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 *	configuration in the TX control data. This handler should,
 *	preferably, never fail and stop queues appropriately, more
 *	importantly, however, it must never fail for A-MPDU-queues.
 *	Must be implemented and atomic.
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 *
 * @start: Called before the first netdevice attached to the hardware
 *	is enabled. This should turn on the hardware and must turn on
 *	frame reception (for possibly enabled monitor interfaces.)
 *	Returns negative error codes, these may be seen in userspace,
 *	or zero.
 *	When the device is started it should not have a MAC address
 *	to avoid acknowledging frames before a non-monitor device
 *	is added.
 *	Must be implemented.
 *
 * @stop: Called after last netdevice attached to the hardware
 *	is disabled. This should turn off the hardware (at least
 *	it must turn off frame reception.)
 *	May be called right after add_interface if that rejects
 *	an interface.
 *	Must be implemented.
 *
 * @add_interface: Called when a netdevice attached to the hardware is
 *	enabled. Because it is not called for monitor mode devices, @open
 *	and @stop must be implemented.
 *	The driver should perform any initialization it needs before
 *	the device can be enabled. The initial configuration for the
 *	interface is given in the conf parameter.
 *	The callback may refuse to add an interface by returning a
 *	negative error code (which will be seen in userspace.)
 *	Must be implemented.
 *
 * @remove_interface: Notifies a driver that an interface is going down.
 *	The @stop callback is called after this if it is the last interface
 *	and no monitor interfaces are present.
 *	When all interfaces are removed, the MAC address in the hardware
 *	must be cleared so the device no longer acknowledges packets,
 *	the mac_addr member of the conf structure is, however, set to the
 *	MAC address of the device going away.
 *	Hence, this callback must be implemented.
 *
 * @config: Handler for configuration requests. IEEE 802.11 code calls this
 *	function to change hardware configuration, e.g., channel.
 *
 * @config_interface: Handler for configuration requests related to interfaces
 *	(e.g. BSSID changes.)
 *
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 * @bss_info_changed: Handler for configuration requests related to BSS
 *	parameters that may vary during BSS's lifespan, and may affect low
 *	level driver (e.g. assoc/disassoc status, erp parameters).
 *	This function should not be used if no BSS has been set, unless
 *	for association indication. The @changed parameter indicates which
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 *	of the bss parameters has changed when a call is made.
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 *
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 * @configure_filter: Configure the device's RX filter.
 *	See the section "Frame filtering" for more information.
 *	This callback must be implemented and atomic.
 *
1146
 * @set_tim: Set TIM bit. mac80211 calls this function when a TIM bit
1147
 * 	must be set or cleared for a given STA. Must be atomic.
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 *
 * @set_key: See the section "Hardware crypto acceleration"
 *	This callback can sleep, and is only called between add_interface
 *	and remove_interface calls, i.e. while the interface with the
 *	given local_address is enabled.
 *
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 * @update_tkip_key: See the section "Hardware crypto acceleration"
 * 	This callback will be called in the context of Rx. Called for drivers
 * 	which set IEEE80211_KEY_FLAG_TKIP_REQ_RX_P1_KEY.
 *
1158
 * @hw_scan: Ask the hardware to service the scan request, no need to start
1159 1160
 *	the scan state machine in stack. The scan must honour the channel
 *	configuration done by the regulatory agent in the wiphy's registered
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 *	bands. When the scan finishes, ieee80211_scan_completed() must be
 *	called; note that it also must be called when the scan cannot finish
 *	because the hardware is turned off! Anything else is a bug!
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 *
 * @get_stats: return low-level statistics
 *
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 * @get_tkip_seq: If your device implements TKIP encryption in hardware this
 *	callback should be provided to read the TKIP transmit IVs (both IV32
 *	and IV16) for the given key from hardware.
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 *
 * @set_rts_threshold: Configuration of RTS threshold (if device needs it)
 *
 * @set_frag_threshold: Configuration of fragmentation threshold. Assign this if
 *	the device does fragmentation by itself; if this method is assigned then
 *	the stack will not do fragmentation.
 *
 * @set_retry_limit: Configuration of retry limits (if device needs it)
 *
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 * @sta_notify: Notifies low level driver about addition or removal
 *	of assocaited station or AP.
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 *
 * @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max),
1183
 *	bursting) for a hardware TX queue.
1184 1185 1186 1187
 *
 * @get_tx_stats: Get statistics of the current TX queue status. This is used
 *	to get number of currently queued packets (queue length), maximum queue
 *	size (limit), and total number of packets sent using each TX queue
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 *	(count). The 'stats' pointer points to an array that has hw->queues +
 *	hw->ampdu_queues items.
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 *
 * @get_tsf: Get the current TSF timer value from firmware/hardware. Currently,
 *	this is only used for IBSS mode debugging and, as such, is not a
 *	required function. Must be atomic.
 *
 * @reset_tsf: Reset the TSF timer and allow firmware/hardware to synchronize
 *	with other STAs in the IBSS. This is only used in IBSS mode. This
 *	function is optional if the firmware/hardware takes full care of
 *	TSF synchronization.
 *
 * @tx_last_beacon: Determine whether the last IBSS beacon was sent by us.
 *	This is needed only for IBSS mode and the result of this function is