kernel-fxtec-pro1x/net/mac80211/sta_info.h
Johannes Berg dd318575ff mac80211: fix RX aggregation locking
The RX aggregation locking documentation was
wrong, which led Christian to also code the
timer timeout handling for it somewhat wrongly.

Fix the documentation, the two places that
need to hold the reorder lock across accesses
to the structure, and the debugfs code that
should just use RCU.

Also, remove acquiring the sta->lock across
reorder timeouts since it isn't necessary, and
change a few places to GFP_KERNEL because the
code path here doesn't need atomic allocations
as I noticed when reviewing all this.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-11-29 15:30:30 -05:00

499 lines
16 KiB
C

/*
* Copyright 2002-2005, Devicescape Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef STA_INFO_H
#define STA_INFO_H
#include <linux/list.h>
#include <linux/types.h>
#include <linux/if_ether.h>
#include <linux/workqueue.h>
#include "key.h"
/**
* enum ieee80211_sta_info_flags - Stations flags
*
* These flags are used with &struct sta_info's @flags member.
*
* @WLAN_STA_AUTH: Station is authenticated.
* @WLAN_STA_ASSOC: Station is associated.
* @WLAN_STA_PS_STA: Station is in power-save mode
* @WLAN_STA_AUTHORIZED: Station is authorized to send/receive traffic.
* This bit is always checked so needs to be enabled for all stations
* when virtual port control is not in use.
* @WLAN_STA_SHORT_PREAMBLE: Station is capable of receiving short-preamble
* frames.
* @WLAN_STA_ASSOC_AP: We're associated to that station, it is an AP.
* @WLAN_STA_WME: Station is a QoS-STA.
* @WLAN_STA_WDS: Station is one of our WDS peers.
* @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
* IEEE80211_TX_CTL_CLEAR_PS_FILT control flag) when the next
* frame to this station is transmitted.
* @WLAN_STA_MFP: Management frame protection is used with this STA.
* @WLAN_STA_BLOCK_BA: Used to deny ADDBA requests (both TX and RX)
* during suspend/resume and station removal.
* @WLAN_STA_PS_DRIVER: driver requires keeping this station in
* power-save mode logically to flush frames that might still
* be in the queues
* @WLAN_STA_PSPOLL: Station sent PS-poll while driver was keeping
* station in power-save mode, reply when the driver unblocks.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH = 1<<0,
WLAN_STA_ASSOC = 1<<1,
WLAN_STA_PS_STA = 1<<2,
WLAN_STA_AUTHORIZED = 1<<3,
WLAN_STA_SHORT_PREAMBLE = 1<<4,
WLAN_STA_ASSOC_AP = 1<<5,
WLAN_STA_WME = 1<<6,
WLAN_STA_WDS = 1<<7,
WLAN_STA_CLEAR_PS_FILT = 1<<9,
WLAN_STA_MFP = 1<<10,
WLAN_STA_BLOCK_BA = 1<<11,
WLAN_STA_PS_DRIVER = 1<<12,
WLAN_STA_PSPOLL = 1<<13,
};
#define STA_TID_NUM 16
#define ADDBA_RESP_INTERVAL HZ
#define HT_AGG_MAX_RETRIES 0x3
#define HT_AGG_STATE_DRV_READY 0
#define HT_AGG_STATE_RESPONSE_RECEIVED 1
#define HT_AGG_STATE_OPERATIONAL 2
#define HT_AGG_STATE_STOPPING 3
#define HT_AGG_STATE_WANT_START 4
#define HT_AGG_STATE_WANT_STOP 5
/**
* struct tid_ampdu_tx - TID aggregation information (Tx).
*
* @rcu_head: rcu head for freeing structure
* @addba_resp_timer: timer for peer's response to addba request
* @pending: pending frames queue -- use sta's spinlock to protect
* @dialog_token: dialog token for aggregation session
* @state: session state (see above)
* @stop_initiator: initiator of a session stop
* @tx_stop: TX DelBA frame when stopping
*
* This structure's lifetime is managed by RCU, assignments to
* the array holding it must hold the aggregation mutex.
*
* The TX path can access it under RCU lock-free if, and
* only if, the state has the flag %HT_AGG_STATE_OPERATIONAL
* set. Otherwise, the TX path must also acquire the spinlock
* and re-check the state, see comments in the tx code
* touching it.
*/
struct tid_ampdu_tx {
struct rcu_head rcu_head;
struct timer_list addba_resp_timer;
struct sk_buff_head pending;
unsigned long state;
u8 dialog_token;
u8 stop_initiator;
bool tx_stop;
};
/**
* struct tid_ampdu_rx - TID aggregation information (Rx).
*
* @reorder_buf: buffer to reorder incoming aggregated MPDUs
* @reorder_time: jiffies when skb was added
* @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
* @reorder_timer: releases expired frames from the reorder buffer.
* @head_seq_num: head sequence number in reordering buffer.
* @stored_mpdu_num: number of MPDUs in reordering buffer
* @ssn: Starting Sequence Number expected to be aggregated.
* @buf_size: buffer size for incoming A-MPDUs
* @timeout: reset timer value (in TUs).
* @dialog_token: dialog token for aggregation session
* @rcu_head: RCU head used for freeing this struct
* @reorder_lock: serializes access to reorder buffer, see below.
*
* This structure's lifetime is managed by RCU, assignments to
* the array holding it must hold the aggregation mutex.
*
* The @reorder_lock is used to protect the members of this
* struct, except for @timeout, @buf_size and @dialog_token,
* which are constant across the lifetime of the struct (the
* dialog token being used only for debugging).
*/
struct tid_ampdu_rx {
struct rcu_head rcu_head;
spinlock_t reorder_lock;
struct sk_buff **reorder_buf;
unsigned long *reorder_time;
struct timer_list session_timer;
struct timer_list reorder_timer;
u16 head_seq_num;
u16 stored_mpdu_num;
u16 ssn;
u16 buf_size;
u16 timeout;
u8 dialog_token;
};
/**
* struct sta_ampdu_mlme - STA aggregation information.
*
* @tid_rx: aggregation info for Rx per TID -- RCU protected
* @tid_tx: aggregation info for Tx per TID
* @addba_req_num: number of times addBA request has been sent.
* @dialog_token_allocator: dialog token enumerator for each new session;
* @work: work struct for starting/stopping aggregation
* @tid_rx_timer_expired: bitmap indicating on which TIDs the
* RX timer expired until the work for it runs
* @mtx: mutex to protect all TX data (except non-NULL assignments
* to tid_tx[idx], which are protected by the sta spinlock)
*/
struct sta_ampdu_mlme {
struct mutex mtx;
/* rx */
struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
unsigned long tid_rx_timer_expired[BITS_TO_LONGS(STA_TID_NUM)];
/* tx */
struct work_struct work;
struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
u8 addba_req_num[STA_TID_NUM];
u8 dialog_token_allocator;
};
/**
* enum plink_state - state of a mesh peer link finite state machine
*
* @PLINK_LISTEN: initial state, considered the implicit state of non 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_info - STA information
*
* This structure collects information about a station that
* mac80211 is communicating with.
*
* @list: global linked list entry
* @hnext: hash table linked list pointer
* @local: pointer to the global information
* @sdata: virtual interface this station belongs to
* @ptk: peer key negotiated with this station, if any
* @gtk: group keys negotiated with this station, if any
* @rate_ctrl: rate control algorithm reference
* @rate_ctrl_priv: rate control private per-STA pointer
* @last_tx_rate: rate used for last transmit, to report to userspace as
* "the" transmit rate
* @lock: used for locking all fields that require locking, see comments
* in the header file.
* @flaglock: spinlock for flags accesses
* @drv_unblock_wk: used for driver PS unblocking
* @listen_interval: listen interval of this station, when we're acting as AP
* @flags: STA flags, see &enum ieee80211_sta_info_flags
* @ps_tx_buf: buffer of frames to transmit to this station
* when it leaves power saving state
* @tx_filtered: buffer of frames we already tried to transmit
* but were filtered by hardware due to STA having entered
* power saving state
* @rx_packets: Number of MSDUs received from this STA
* @rx_bytes: Number of bytes received from this STA
* @wep_weak_iv_count: number of weak WEP IVs received from this station
* @last_rx: time (in jiffies) when last frame was received from this STA
* @num_duplicates: number of duplicate frames received from this STA
* @rx_fragments: number of received MPDUs
* @rx_dropped: number of dropped MPDUs from this STA
* @last_signal: signal of last received frame from this STA
* @last_seq_ctrl: last received seq/frag number from this STA (per RX queue)
* @tx_filtered_count: number of frames the hardware filtered for this STA
* @tx_retry_failed: number of frames that failed retry
* @tx_retry_count: total number of retries for frames to this STA
* @fail_avg: moving percentage of failed MSDUs
* @tx_packets: number of RX/TX MSDUs
* @tx_bytes: number of bytes transmitted to this STA
* @tx_fragments: number of transmitted MPDUs
* @tid_seq: per-TID sequence numbers for sending to this STA
* @ampdu_mlme: A-MPDU state machine state
* @timer_to_tid: identity mapping to ID timers
* @llid: Local link ID
* @plid: Peer link ID
* @reason: Cancel reason on PLINK_HOLDING state
* @plink_retries: Retries in establishment
* @ignore_plink_timer: ignore the peer-link timer (used internally)
* @plink_state: peer link state
* @plink_timeout: timeout of peer link
* @plink_timer: peer link watch timer
* @plink_timer_was_running: used by suspend/resume to restore timers
* @debugfs: debug filesystem info
* @sta: station information we share with the driver
* @dead: set to true when sta is unlinked
* @uploaded: set to true when sta is uploaded to the driver
* @lost_packets: number of consecutive lost packets
*/
struct sta_info {
/* General information, mostly static */
struct list_head list;
struct sta_info *hnext;
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_key *gtk[NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS];
struct ieee80211_key *ptk;
struct rate_control_ref *rate_ctrl;
void *rate_ctrl_priv;
spinlock_t lock;
spinlock_t flaglock;
struct work_struct drv_unblock_wk;
u16 listen_interval;
bool dead;
bool uploaded;
/*
* frequently updated, locked with own spinlock (flaglock),
* use the accessors defined below
*/
u32 flags;
/*
* STA powersave frame queues, no more than the internal
* locking required.
*/
struct sk_buff_head ps_tx_buf;
struct sk_buff_head tx_filtered;
/* Updated from RX path only, no locking requirements */
unsigned long rx_packets, rx_bytes;
unsigned long wep_weak_iv_count;
unsigned long last_rx;
unsigned long num_duplicates;
unsigned long rx_fragments;
unsigned long rx_dropped;
int last_signal;
__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];
/* Updated from TX status path only, no locking requirements */
unsigned long tx_filtered_count;
unsigned long tx_retry_failed, tx_retry_count;
/* moving percentage of failed MSDUs */
unsigned int fail_avg;
/* Updated from TX path only, no locking requirements */
unsigned long tx_packets;
unsigned long tx_bytes;
unsigned long tx_fragments;
struct ieee80211_tx_rate last_tx_rate;
u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
/*
* Aggregation information, locked with lock.
*/
struct sta_ampdu_mlme ampdu_mlme;
u8 timer_to_tid[STA_TID_NUM];
#ifdef CONFIG_MAC80211_MESH
/*
* Mesh peer link attributes
* TODO: move to a sub-structure that is referenced with pointer?
*/
__le16 llid;
__le16 plid;
__le16 reason;
u8 plink_retries;
bool ignore_plink_timer;
bool plink_timer_was_running;
enum plink_state plink_state;
u32 plink_timeout;
struct timer_list plink_timer;
#endif
#ifdef CONFIG_MAC80211_DEBUGFS
struct sta_info_debugfsdentries {
struct dentry *dir;
bool add_has_run;
} debugfs;
#endif
unsigned int lost_packets;
/* keep last! */
struct ieee80211_sta sta;
};
static inline enum plink_state sta_plink_state(struct sta_info *sta)
{
#ifdef CONFIG_MAC80211_MESH
return sta->plink_state;
#endif
return PLINK_LISTEN;
}
static inline void set_sta_flags(struct sta_info *sta, const u32 flags)
{
unsigned long irqfl;
spin_lock_irqsave(&sta->flaglock, irqfl);
sta->flags |= flags;
spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
static inline void clear_sta_flags(struct sta_info *sta, const u32 flags)
{
unsigned long irqfl;
spin_lock_irqsave(&sta->flaglock, irqfl);
sta->flags &= ~flags;
spin_unlock_irqrestore(&sta->flaglock, irqfl);
}
static inline u32 test_sta_flags(struct sta_info *sta, const u32 flags)
{
u32 ret;
unsigned long irqfl;
spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags & flags;
spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}
static inline u32 test_and_clear_sta_flags(struct sta_info *sta,
const u32 flags)
{
u32 ret;
unsigned long irqfl;
spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags & flags;
sta->flags &= ~flags;
spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}
static inline u32 get_sta_flags(struct sta_info *sta)
{
u32 ret;
unsigned long irqfl;
spin_lock_irqsave(&sta->flaglock, irqfl);
ret = sta->flags;
spin_unlock_irqrestore(&sta->flaglock, irqfl);
return ret;
}
#define STA_HASH_SIZE 256
#define STA_HASH(sta) (sta[5])
/* Maximum number of frames to buffer per power saving station */
#define STA_MAX_TX_BUFFER 128
/* Minimum buffered frame expiry time. If STA uses listen interval that is
* smaller than this value, the minimum value here is used instead. */
#define STA_TX_BUFFER_EXPIRE (10 * HZ)
/* How often station data is cleaned up (e.g., expiration of buffered frames)
*/
#define STA_INFO_CLEANUP_INTERVAL (10 * HZ)
/*
* Get a STA info, must be under RCU read lock.
*/
struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
static inline
void for_each_sta_info_type_check(struct ieee80211_local *local,
const u8 *addr,
struct sta_info *sta,
struct sta_info *nxt)
{
}
#define for_each_sta_info(local, _addr, _sta, nxt) \
for ( /* initialise loop */ \
_sta = rcu_dereference(local->sta_hash[STA_HASH(_addr)]),\
nxt = _sta ? rcu_dereference(_sta->hnext) : NULL; \
/* typecheck */ \
for_each_sta_info_type_check(local, (_addr), _sta, nxt),\
/* continue condition */ \
_sta; \
/* advance loop */ \
_sta = nxt, \
nxt = _sta ? rcu_dereference(_sta->hnext) : NULL \
) \
/* compare address and run code only if it matches */ \
if (memcmp(_sta->sta.addr, (_addr), ETH_ALEN) == 0)
/*
* Get STA info by index, BROKEN!
*/
struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
int idx);
/*
* Create a new STA info, caller owns returned structure
* until sta_info_insert().
*/
struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
u8 *addr, gfp_t gfp);
/*
* Insert STA info into hash table/list, returns zero or a
* -EEXIST if (if the same MAC address is already present).
*
* Calling the non-rcu version makes the caller relinquish,
* the _rcu version calls read_lock_rcu() and must be called
* without it held.
*/
int sta_info_insert(struct sta_info *sta);
int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
int sta_info_insert_atomic(struct sta_info *sta);
int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
void sta_info_set_tim_bit(struct sta_info *sta);
void sta_info_clear_tim_bit(struct sta_info *sta);
void sta_info_init(struct ieee80211_local *local);
int sta_info_start(struct ieee80211_local *local);
void sta_info_stop(struct ieee80211_local *local);
int sta_info_flush(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata);
void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
unsigned long exp_time);
void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta);
void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta);
#endif /* STA_INFO_H */