net/mac80211/sta_info.h

   1 /*
   2  * Copyright 2002-2005, Devicescape Software, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #ifndef STA_INFO_H
  10 #define STA_INFO_H
  11
  12 #include <linux/list.h>
  13 #include <linux/types.h>
  14 #include <linux/if_ether.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/average.h>
  17 #include <linux/etherdevice.h>
  18 #include "key.h"
  19
  20 /**
  21  * enum ieee80211_sta_info_flags - Stations flags
  22  *
  23  * These flags are used with &struct sta_info's @flags member, but
  24  * only indirectly with set_sta_flag() and friends.
  25  *
  26  * @WLAN_STA_AUTH: Station is authenticated.
  27  * @WLAN_STA_ASSOC: Station is associated.
  28  * @WLAN_STA_PS_STA: Station is in power-save mode
  29  * @WLAN_STA_AUTHORIZED: Station is authorized to send/receive traffic.
  30  *      This bit is always checked so needs to be enabled for all stations
  31  *      when virtual port control is not in use.
  32  * @WLAN_STA_SHORT_PREAMBLE: Station is capable of receiving short-preamble
  33  *      frames.
  34  * @WLAN_STA_WME: Station is a QoS-STA.
  35  * @WLAN_STA_WDS: Station is one of our WDS peers.
  36  * @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
  37  *      IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
  38  *      frame to this station is transmitted.
  39  * @WLAN_STA_MFP: Management frame protection is used with this STA.
  40  * @WLAN_STA_BLOCK_BA: Used to deny ADDBA requests (both TX and RX)
  41  *      during suspend/resume and station removal.
  42  * @WLAN_STA_PS_DRIVER: driver requires keeping this station in
  43  *      power-save mode logically to flush frames that might still
  44  *      be in the queues
  45  * @WLAN_STA_PSPOLL: Station sent PS-poll while driver was keeping
  46  *      station in power-save mode, reply when the driver unblocks.
  47  * @WLAN_STA_TDLS_PEER: Station is a TDLS peer.
  48  * @WLAN_STA_TDLS_PEER_AUTH: This TDLS peer is authorized to send direct
  49  *      packets. This means the link is enabled.
  50  * @WLAN_STA_UAPSD: Station requested unscheduled SP while driver was
  51  *      keeping station in power-save mode, reply when the driver
  52  *      unblocks the station.
  53  * @WLAN_STA_SP: Station is in a service period, so don't try to
  54  *      reply to other uAPSD trigger frames or PS-Poll.
  55  * @WLAN_STA_4ADDR_EVENT: 4-addr event was already sent for this frame.
  56  * @WLAN_STA_INSERTED: This station is inserted into the hash table.
  57  * @WLAN_STA_RATE_CONTROL: rate control was initialized for this station.
  58  * @WLAN_STA_TOFFSET_KNOWN: toffset calculated for this station is valid.
  59  * @WLAN_STA_MPSP_OWNER: local STA is owner of a mesh Peer Service Period.
  60  * @WLAN_STA_MPSP_RECIPIENT: local STA is recipient of a MPSP.
  61  */
  62 enum ieee80211_sta_info_flags {
  63         WLAN_STA_AUTH,
  64         WLAN_STA_ASSOC,
  65         WLAN_STA_PS_STA,
  66         WLAN_STA_AUTHORIZED,
  67         WLAN_STA_SHORT_PREAMBLE,
  68         WLAN_STA_WME,
  69         WLAN_STA_WDS,
  70         WLAN_STA_CLEAR_PS_FILT,
  71         WLAN_STA_MFP,
  72         WLAN_STA_BLOCK_BA,
  73         WLAN_STA_PS_DRIVER,
  74         WLAN_STA_PSPOLL,
  75         WLAN_STA_TDLS_PEER,
  76         WLAN_STA_TDLS_PEER_AUTH,
  77         WLAN_STA_UAPSD,
  78         WLAN_STA_SP,
  79         WLAN_STA_4ADDR_EVENT,
  80         WLAN_STA_INSERTED,
  81         WLAN_STA_RATE_CONTROL,
  82         WLAN_STA_TOFFSET_KNOWN,
  83         WLAN_STA_MPSP_OWNER,
  84         WLAN_STA_MPSP_RECIPIENT,
  85 };
  86
  87 #define ADDBA_RESP_INTERVAL HZ
  88 #define HT_AGG_MAX_RETRIES              15
  89 #define HT_AGG_BURST_RETRIES            3
  90 #define HT_AGG_RETRIES_PERIOD           (15 * HZ)
  91
  92 #define HT_AGG_STATE_DRV_READY          0
  93 #define HT_AGG_STATE_RESPONSE_RECEIVED  1
  94 #define HT_AGG_STATE_OPERATIONAL        2
  95 #define HT_AGG_STATE_STOPPING           3
  96 #define HT_AGG_STATE_WANT_START         4
  97 #define HT_AGG_STATE_WANT_STOP          5
  98
  99 enum ieee80211_agg_stop_reason {
 100         AGG_STOP_DECLINED,
 101         AGG_STOP_LOCAL_REQUEST,
 102         AGG_STOP_PEER_REQUEST,
 103         AGG_STOP_DESTROY_STA,
 104 };
 105
 106 /**
 107  * struct tid_ampdu_tx - TID aggregation information (Tx).
 108  *
 109  * @rcu_head: rcu head for freeing structure
 110  * @session_timer: check if we keep Tx-ing on the TID (by timeout value)
 111  * @addba_resp_timer: timer for peer's response to addba request
 112  * @pending: pending frames queue -- use sta's spinlock to protect
 113  * @dialog_token: dialog token for aggregation session
 114  * @timeout: session timeout value to be filled in ADDBA requests
 115  * @state: session state (see above)
 116  * @last_tx: jiffies of last tx activity
 117  * @stop_initiator: initiator of a session stop
 118  * @tx_stop: TX DelBA frame when stopping
 119  * @buf_size: reorder buffer size at receiver
 120  * @failed_bar_ssn: ssn of the last failed BAR tx attempt
 121  * @bar_pending: BAR needs to be re-sent
 122  *
 123  * This structure's lifetime is managed by RCU, assignments to
 124  * the array holding it must hold the aggregation mutex.
 125  *
 126  * The TX path can access it under RCU lock-free if, and
 127  * only if, the state has the flag %HT_AGG_STATE_OPERATIONAL
 128  * set. Otherwise, the TX path must also acquire the spinlock
 129  * and re-check the state, see comments in the tx code
 130  * touching it.
 131  */
 132 struct tid_ampdu_tx {
 133         struct rcu_head rcu_head;
 134         struct timer_list session_timer;
 135         struct timer_list addba_resp_timer;
 136         struct sk_buff_head pending;
 137         unsigned long state;
 138         unsigned long last_tx;
 139         u16 timeout;
 140         u8 dialog_token;
 141         u8 stop_initiator;
 142         bool tx_stop;
 143         u8 buf_size;
 144
 145         u16 failed_bar_ssn;
 146         bool bar_pending;
 147 };
 148
 149 /**
 150  * struct tid_ampdu_rx - TID aggregation information (Rx).
 151  *
 152  * @reorder_buf: buffer to reorder incoming aggregated MPDUs
 153  * @reorder_time: jiffies when skb was added
 154  * @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
 155  * @reorder_timer: releases expired frames from the reorder buffer.
 156  * @last_rx: jiffies of last rx activity
 157  * @head_seq_num: head sequence number in reordering buffer.
 158  * @stored_mpdu_num: number of MPDUs in reordering buffer
 159  * @ssn: Starting Sequence Number expected to be aggregated.
 160  * @buf_size: buffer size for incoming A-MPDUs
 161  * @timeout: reset timer value (in TUs).
 162  * @dialog_token: dialog token for aggregation session
 163  * @rcu_head: RCU head used for freeing this struct
 164  * @reorder_lock: serializes access to reorder buffer, see below.
 165  *
 166  * This structure's lifetime is managed by RCU, assignments to
 167  * the array holding it must hold the aggregation mutex.
 168  *
 169  * The @reorder_lock is used to protect the members of this
 170  * struct, except for @timeout, @buf_size and @dialog_token,
 171  * which are constant across the lifetime of the struct (the
 172  * dialog token being used only for debugging).
 173  */
 174 struct tid_ampdu_rx {
 175         struct rcu_head rcu_head;
 176         spinlock_t reorder_lock;
 177         struct sk_buff **reorder_buf;
 178         unsigned long *reorder_time;
 179         struct timer_list session_timer;
 180         struct timer_list reorder_timer;
 181         unsigned long last_rx;
 182         u16 head_seq_num;
 183         u16 stored_mpdu_num;
 184         u16 ssn;
 185         u16 buf_size;
 186         u16 timeout;
 187         u8 dialog_token;
 188 };
 189
 190 /**
 191  * struct sta_ampdu_mlme - STA aggregation information.
 192  *
 193  * @tid_rx: aggregation info for Rx per TID -- RCU protected
 194  * @tid_tx: aggregation info for Tx per TID
 195  * @tid_start_tx: sessions where start was requested
 196  * @addba_req_num: number of times addBA request has been sent.
 197  * @last_addba_req_time: timestamp of the last addBA request.
 198  * @dialog_token_allocator: dialog token enumerator for each new session;
 199  * @work: work struct for starting/stopping aggregation
 200  * @tid_rx_timer_expired: bitmap indicating on which TIDs the
 201  *      RX timer expired until the work for it runs
 202  * @tid_rx_stop_requested:  bitmap indicating which BA sessions per TID the
 203  *      driver requested to close until the work for it runs
 204  * @mtx: mutex to protect all TX data (except non-NULL assignments
 205  *      to tid_tx[idx], which are protected by the sta spinlock)
 206  *      tid_start_tx is also protected by sta->lock.
 207  */
 208 struct sta_ampdu_mlme {
 209         struct mutex mtx;
 210         /* rx */
 211         struct tid_ampdu_rx __rcu *tid_rx[IEEE80211_NUM_TIDS];
 212         unsigned long tid_rx_timer_expired[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
 213         unsigned long tid_rx_stop_requested[BITS_TO_LONGS(IEEE80211_NUM_TIDS)];
 214         /* tx */
 215         struct work_struct work;
 216         struct tid_ampdu_tx __rcu *tid_tx[IEEE80211_NUM_TIDS];
 217         struct tid_ampdu_tx *tid_start_tx[IEEE80211_NUM_TIDS];
 218         unsigned long last_addba_req_time[IEEE80211_NUM_TIDS];
 219         u8 addba_req_num[IEEE80211_NUM_TIDS];
 220         u8 dialog_token_allocator;
 221 };
 222
 223
 224 /**
 225  * struct sta_info - STA information
 226  *
 227  * This structure collects information about a station that
 228  * mac80211 is communicating with.
 229  *
 230  * @list: global linked list entry
 231  * @hnext: hash table linked list pointer
 232  * @local: pointer to the global information
 233  * @sdata: virtual interface this station belongs to
 234  * @ptk: peer key negotiated with this station, if any
 235  * @gtk: group keys negotiated with this station, if any
 236  * @rate_ctrl: rate control algorithm reference
 237  * @rate_ctrl_priv: rate control private per-STA pointer
 238  * @last_tx_rate: rate used for last transmit, to report to userspace as
 239  *      "the" transmit rate
 240  * @last_rx_rate_idx: rx status rate index of the last data packet
 241  * @last_rx_rate_flag: rx status flag of the last data packet
 242  * @last_rx_rate_vht_nss: rx status nss of last data packet
 243  * @lock: used for locking all fields that require locking, see comments
 244  *      in the header file.
 245  * @drv_unblock_wk: used for driver PS unblocking
 246  * @listen_interval: listen interval of this station, when we're acting as AP
 247  * @_flags: STA flags, see &enum ieee80211_sta_info_flags, do not use directly
 248  * @ps_tx_buf: buffers (per AC) of frames to transmit to this station
 249  *      when it leaves power saving state or polls
 250  * @tx_filtered: buffers (per AC) of frames we already tried to
 251  *      transmit but were filtered by hardware due to STA having
 252  *      entered power saving state, these are also delivered to
 253  *      the station when it leaves powersave or polls for frames
 254  * @driver_buffered_tids: bitmap of TIDs the driver has data buffered on
 255  * @rx_packets: Number of MSDUs received from this STA
 256  * @rx_bytes: Number of bytes received from this STA
 257  * @wep_weak_iv_count: number of weak WEP IVs received from this station
 258  * @last_rx: time (in jiffies) when last frame was received from this STA
 259  * @last_connected: time (in seconds) when a station got connected
 260  * @num_duplicates: number of duplicate frames received from this STA
 261  * @rx_fragments: number of received MPDUs
 262  * @rx_dropped: number of dropped MPDUs from this STA
 263  * @last_signal: signal of last received frame from this STA
 264  * @avg_signal: moving average of signal of received frames from this STA
 265  * @last_ack_signal: signal of last received Ack frame from this STA
 266  * @last_seq_ctrl: last received seq/frag number from this STA (per RX queue)
 267  * @tx_filtered_count: number of frames the hardware filtered for this STA
 268  * @tx_retry_failed: number of frames that failed retry
 269  * @tx_retry_count: total number of retries for frames to this STA
 270  * @fail_avg: moving percentage of failed MSDUs
 271  * @tx_packets: number of RX/TX MSDUs
 272  * @tx_bytes: number of bytes transmitted to this STA
 273  * @tx_fragments: number of transmitted MPDUs
 274  * @tid_seq: per-TID sequence numbers for sending to this STA
 275  * @ampdu_mlme: A-MPDU state machine state
 276  * @timer_to_tid: identity mapping to ID timers
 277  * @llid: Local link ID
 278  * @plid: Peer link ID
 279  * @reason: Cancel reason on PLINK_HOLDING state
 280  * @plink_retries: Retries in establishment
 281  * @ignore_plink_timer: ignore the peer-link timer (used internally)
 282  * @plink_state: peer link state
 283  * @plink_timeout: timeout of peer link
 284  * @plink_timer: peer link watch timer
 285  * @t_offset: timing offset relative to this host
 286  * @t_offset_setpoint: reference timing offset of this sta to be used when
 287  *      calculating clockdrift
 288  * @local_pm: local link-specific power save mode
 289  * @peer_pm: peer-specific power save mode towards local STA
 290  * @nonpeer_pm: STA power save mode towards non-peer neighbors
 291  * @debugfs: debug filesystem info
 292  * @dead: set to true when sta is unlinked
 293  * @uploaded: set to true when sta is uploaded to the driver
 294  * @lost_packets: number of consecutive lost packets
 295  * @sta: station information we share with the driver
 296  * @sta_state: duplicates information about station state (for debug)
 297  * @beacon_loss_count: number of times beacon loss has triggered
 298  * @rcu_head: RCU head used for freeing this station struct
 299  * @cur_max_bandwidth: maximum bandwidth to use for TX to the station,
 300  *      taken from HT/VHT capabilities or VHT operating mode notification
 301  * @chains: chains ever used for RX from this station
 302  * @chain_signal_last: last signal (per chain)
 303  * @chain_signal_avg: signal average (per chain)
 304  * @known_smps_mode: the smps_mode the client thinks we are in. Relevant for
 305  *      AP only.
 306  */
 307 struct sta_info {
 308         /* General information, mostly static */
 309         struct list_head list;
 310         struct rcu_head rcu_head;
 311         struct sta_info __rcu *hnext;
 312         struct ieee80211_local *local;
 313         struct ieee80211_sub_if_data *sdata;
 314         struct ieee80211_key __rcu *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
 315         struct ieee80211_key __rcu *ptk;
 316         struct rate_control_ref *rate_ctrl;
 317         void *rate_ctrl_priv;
 318         spinlock_t lock;
 319
 320         struct work_struct drv_unblock_wk;
 321
 322         u16 listen_interval;
 323
 324         bool dead;
 325
 326         bool uploaded;
 327
 328         enum ieee80211_sta_state sta_state;
 329
 330         /* use the accessors defined below */
 331         unsigned long _flags;
 332
 333         /*
 334          * STA powersave frame queues, no more than the internal
 335          * locking required.
 336          */
 337         struct sk_buff_head ps_tx_buf[IEEE80211_NUM_ACS];
 338         struct sk_buff_head tx_filtered[IEEE80211_NUM_ACS];
 339         unsigned long driver_buffered_tids;
 340
 341         /* Updated from RX path only, no locking requirements */
 342         unsigned long rx_packets;
 343         u64 rx_bytes;
 344         unsigned long wep_weak_iv_count;
 345         unsigned long last_rx;
 346         long last_connected;
 347         unsigned long num_duplicates;
 348         unsigned long rx_fragments;
 349         unsigned long rx_dropped;
 350         int last_signal;
 351         struct ewma avg_signal;
 352         int last_ack_signal;
 353
 354         u8 chains;
 355         s8 chain_signal_last[IEEE80211_MAX_CHAINS];
 356         struct ewma chain_signal_avg[IEEE80211_MAX_CHAINS];
 357
 358         /* Plus 1 for non-QoS frames */
 359         __le16 last_seq_ctrl[IEEE80211_NUM_TIDS + 1];
 360
 361         /* Updated from TX status path only, no locking requirements */
 362         unsigned long tx_filtered_count;
 363         unsigned long tx_retry_failed, tx_retry_count;
 364         /* moving percentage of failed MSDUs */
 365         unsigned int fail_avg;
 366
 367         /* Updated from TX path only, no locking requirements */
 368         u32 tx_fragments;
 369         u64 tx_packets[IEEE80211_NUM_ACS];
 370         u64 tx_bytes[IEEE80211_NUM_ACS];
 371         struct ieee80211_tx_rate last_tx_rate;
 372         int last_rx_rate_idx;
 373         u32 last_rx_rate_flag;
 374         u8 last_rx_rate_vht_nss;
 375         u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
 376
 377         /*
 378          * Aggregation information, locked with lock.
 379          */
 380         struct sta_ampdu_mlme ampdu_mlme;
 381         u8 timer_to_tid[IEEE80211_NUM_TIDS];
 382
 383 #ifdef CONFIG_MAC80211_MESH
 384         /*
 385          * Mesh peer link attributes
 386          * TODO: move to a sub-structure that is referenced with pointer?
 387          */
 388         __le16 llid;
 389         __le16 plid;
 390         __le16 reason;
 391         u8 plink_retries;
 392         bool ignore_plink_timer;
 393         enum nl80211_plink_state plink_state;
 394         u32 plink_timeout;
 395         struct timer_list plink_timer;
 396         s64 t_offset;
 397         s64 t_offset_setpoint;
 398         /* mesh power save */
 399         enum nl80211_mesh_power_mode local_pm;
 400         enum nl80211_mesh_power_mode peer_pm;
 401         enum nl80211_mesh_power_mode nonpeer_pm;
 402 #endif
 403
 404 #ifdef CONFIG_MAC80211_DEBUGFS
 405         struct sta_info_debugfsdentries {
 406                 struct dentry *dir;
 407                 bool add_has_run;
 408         } debugfs;
 409 #endif
 410
 411         enum ieee80211_sta_rx_bandwidth cur_max_bandwidth;
 412
 413         unsigned int lost_packets;
 414         unsigned int beacon_loss_count;
 415
 416         enum ieee80211_smps_mode known_smps_mode;
 417
 418         /* keep last! */
 419         struct ieee80211_sta sta;
 420 };
 421
 422 static inline enum nl80211_plink_state sta_plink_state(struct sta_info *sta)
 423 {
 424 #ifdef CONFIG_MAC80211_MESH
 425         return sta->plink_state;
 426 #endif
 427         return NL80211_PLINK_LISTEN;
 428 }
 429
 430 static inline void set_sta_flag(struct sta_info *sta,
 431                                 enum ieee80211_sta_info_flags flag)
 432 {
 433         WARN_ON(flag == WLAN_STA_AUTH ||
 434                 flag == WLAN_STA_ASSOC ||
 435                 flag == WLAN_STA_AUTHORIZED);
 436         set_bit(flag, &sta->_flags);
 437 }
 438
 439 static inline void clear_sta_flag(struct sta_info *sta,
 440                                   enum ieee80211_sta_info_flags flag)
 441 {
 442         WARN_ON(flag == WLAN_STA_AUTH ||
 443                 flag == WLAN_STA_ASSOC ||
 444                 flag == WLAN_STA_AUTHORIZED);
 445         clear_bit(flag, &sta->_flags);
 446 }
 447
 448 static inline int test_sta_flag(struct sta_info *sta,
 449                                 enum ieee80211_sta_info_flags flag)
 450 {
 451         return test_bit(flag, &sta->_flags);
 452 }
 453
 454 static inline int test_and_clear_sta_flag(struct sta_info *sta,
 455                                           enum ieee80211_sta_info_flags flag)
 456 {
 457         WARN_ON(flag == WLAN_STA_AUTH ||
 458                 flag == WLAN_STA_ASSOC ||
 459                 flag == WLAN_STA_AUTHORIZED);
 460         return test_and_clear_bit(flag, &sta->_flags);
 461 }
 462
 463 static inline int test_and_set_sta_flag(struct sta_info *sta,
 464                                         enum ieee80211_sta_info_flags flag)
 465 {
 466         WARN_ON(flag == WLAN_STA_AUTH ||
 467                 flag == WLAN_STA_ASSOC ||
 468                 flag == WLAN_STA_AUTHORIZED);
 469         return test_and_set_bit(flag, &sta->_flags);
 470 }
 471
 472 int sta_info_move_state(struct sta_info *sta,
 473                         enum ieee80211_sta_state new_state);
 474
 475 static inline void sta_info_pre_move_state(struct sta_info *sta,
 476                                            enum ieee80211_sta_state new_state)
 477 {
 478         int ret;
 479
 480         WARN_ON_ONCE(test_sta_flag(sta, WLAN_STA_INSERTED));
 481
 482         ret = sta_info_move_state(sta, new_state);
 483         WARN_ON_ONCE(ret);
 484 }
 485
 486
 487 void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
 488                              struct tid_ampdu_tx *tid_tx);
 489
 490 static inline struct tid_ampdu_tx *
 491 rcu_dereference_protected_tid_tx(struct sta_info *sta, int tid)
 492 {
 493         return rcu_dereference_protected(sta->ampdu_mlme.tid_tx[tid],
 494                                          lockdep_is_held(&sta->lock) ||
 495                                          lockdep_is_held(&sta->ampdu_mlme.mtx));
 496 }
 497
 498 #define STA_HASH_SIZE 256
 499 #define STA_HASH(sta) (sta[5])
 500
 501
 502 /* Maximum number of frames to buffer per power saving station per AC */
 503 #define STA_MAX_TX_BUFFER       64
 504
 505 /* Minimum buffered frame expiry time. If STA uses listen interval that is
 506  * smaller than this value, the minimum value here is used instead. */
 507 #define STA_TX_BUFFER_EXPIRE (10 * HZ)
 508
 509 /* How often station data is cleaned up (e.g., expiration of buffered frames)
 510  */
 511 #define STA_INFO_CLEANUP_INTERVAL (10 * HZ)
 512
 513 /*
 514  * Get a STA info, must be under RCU read lock.
 515  */
 516 struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
 517                               const u8 *addr);
 518
 519 struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
 520                                   const u8 *addr);
 521
 522 static inline
 523 void for_each_sta_info_type_check(struct ieee80211_local *local,
 524                                   const u8 *addr,
 525                                   struct sta_info *sta,
 526                                   struct sta_info *nxt)
 527 {
 528 }
 529
 530 #define for_each_sta_info(local, _addr, _sta, nxt)                      \
 531         for (   /* initialise loop */                                   \
 532                 _sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
 533                 nxt = _sta ? rcu_dereference(_sta->hnext) : NULL;       \
 534                 /* typecheck */                                         \
 535                 for_each_sta_info_type_check(local, (_addr), _sta, nxt),\
 536                 /* continue condition */                                \
 537                 _sta;                                                   \
 538                 /* advance loop */                                      \
 539                 _sta = nxt,                                             \
 540                 nxt = _sta ? rcu_dereference(_sta->hnext) : NULL        \
 541              )                                                          \
 542         /* compare address and run code only if it matches */           \
 543         if (ether_addr_equal(_sta->sta.addr, (_addr)))
 544
 545 /*
 546  * Get STA info by index, BROKEN!
 547  */
 548 struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
 549                                      int idx);
 550 /*
 551  * Create a new STA info, caller owns returned structure
 552  * until sta_info_insert().
 553  */
 554 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 555                                 const u8 *addr, gfp_t gfp);
 556
 557 void sta_info_free(struct ieee80211_local *local, struct sta_info *sta);
 558
 559 /*
 560  * Insert STA info into hash table/list, returns zero or a
 561  * -EEXIST if (if the same MAC address is already present).
 562  *
 563  * Calling the non-rcu version makes the caller relinquish,
 564  * the _rcu version calls read_lock_rcu() and must be called
 565  * without it held.
 566  */
 567 int sta_info_insert(struct sta_info *sta);
 568 int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
 569
 570 int __must_check __sta_info_destroy(struct sta_info *sta);
 571 int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
 572                           const u8 *addr);
 573 int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
 574                               const u8 *addr);
 575
 576 void sta_info_recalc_tim(struct sta_info *sta);
 577
 578 void sta_info_init(struct ieee80211_local *local);
 579 void sta_info_stop(struct ieee80211_local *local);
 580 int sta_info_flush_defer(struct ieee80211_sub_if_data *sdata);
 581
 582 /**
 583  * sta_info_flush_cleanup - flush the sta_info cleanup queue
 584  * @sdata: the interface
 585  *
 586  * Flushes the sta_info cleanup queue for a given interface;
 587  * this is necessary before the interface is removed or, for
 588  * AP/mesh interfaces, before it is deconfigured.
 589  *
 590  * Note an rcu_barrier() must precede the function, after all
 591  * stations have been flushed/removed to ensure the call_rcu()
 592  * calls that add stations to the cleanup queue have completed.
 593  */
 594 void sta_info_flush_cleanup(struct ieee80211_sub_if_data *sdata);
 595
 596 /**
 597  * sta_info_flush - flush matching STA entries from the STA table
 598  *
 599  * Returns the number of removed STA entries.
 600  *
 601  * @sdata: sdata to remove all stations from
 602  */
 603 static inline int sta_info_flush(struct ieee80211_sub_if_data *sdata)
 604 {
 605         int ret = sta_info_flush_defer(sdata);
 606
 607         rcu_barrier();
 608         sta_info_flush_cleanup(sdata);
 609
 610         return ret;
 611 }
 612
 613 void sta_set_rate_info_tx(struct sta_info *sta,
 614                           const struct ieee80211_tx_rate *rate,
 615                           struct rate_info *rinfo);
 616 void sta_set_rate_info_rx(struct sta_info *sta,
 617                           struct rate_info *rinfo);
 618 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
 619                           unsigned long exp_time);
 620 u8 sta_info_tx_streams(struct sta_info *sta);
 621
 622 void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta);
 623 void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta);
 624 void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta);
 625
 626 void ieee80211_cleanup_sdata_stas(struct ieee80211_sub_if_data *sdata);
 627
 628 #endif /* STA_INFO_H */