kernel-hacking-2024-linux-s.../net/mac80211/sta_info.h
Johannes Berg d0709a6518 mac80211: RCU-ify STA info structure access
This makes access to the STA hash table/list use RCU to protect
against freeing of items. However, it's not a true RCU, the
copy step is missing: whenever somebody changes a STA item it
is simply updated. This is an existing race condition that is
now somewhat understandable.

This patch also fixes the race key freeing vs. STA destruction
by making sure that sta_info_destroy() is always called under
RTNL and frees the key.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-03-06 15:30:46 -05:00

309 lines
9.1 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 "ieee80211_key.h"
/**
* enum ieee80211_sta_info_flags - Stations flags
*
* These flags are used with &struct sta_info's @flags member.
*
* @WLAN_STA_AUTH: Station is authenticated.
* @WLAN_STA_ASSOC: Station is associated.
* @WLAN_STA_PS: Station is in power-save mode
* @WLAN_STA_AUTHORIZED: Station is authorized to send/receive traffic.
* This bit is always checked so needs to be enabled for all stations
* when virtual port control is not in use.
* @WLAN_STA_SHORT_PREAMBLE: Station is capable of receiving short-preamble
* frames.
* @WLAN_STA_ASSOC_AP: We're associated to that station, it is an AP.
* @WLAN_STA_WME: Station is a QoS-STA.
* @WLAN_STA_WDS: Station is one of our WDS peers.
* @WLAN_STA_PSPOLL: Station has just PS-polled us.
* @WLAN_STA_CLEAR_PS_FILT: Clear PS filter in hardware (using the
* IEEE80211_TXCTL_CLEAR_PS_FILT control flag) when the next
* frame to this station is transmitted.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH = 1<<0,
WLAN_STA_ASSOC = 1<<1,
WLAN_STA_PS = 1<<2,
WLAN_STA_AUTHORIZED = 1<<3,
WLAN_STA_SHORT_PREAMBLE = 1<<4,
WLAN_STA_ASSOC_AP = 1<<5,
WLAN_STA_WME = 1<<6,
WLAN_STA_WDS = 1<<7,
WLAN_STA_PSPOLL = 1<<8,
WLAN_STA_CLEAR_PS_FILT = 1<<9,
};
#define STA_TID_NUM 16
#define ADDBA_RESP_INTERVAL HZ
#define HT_AGG_MAX_RETRIES (0x3)
#define HT_AGG_STATE_INITIATOR_SHIFT (4)
#define HT_ADDBA_REQUESTED_MSK BIT(0)
#define HT_ADDBA_DRV_READY_MSK BIT(1)
#define HT_ADDBA_RECEIVED_MSK BIT(2)
#define HT_AGG_STATE_REQ_STOP_BA_MSK BIT(3)
#define HT_AGG_STATE_INITIATOR_MSK BIT(HT_AGG_STATE_INITIATOR_SHIFT)
#define HT_AGG_STATE_IDLE (0x0)
#define HT_AGG_STATE_OPERATIONAL (HT_ADDBA_REQUESTED_MSK | \
HT_ADDBA_DRV_READY_MSK | \
HT_ADDBA_RECEIVED_MSK)
/**
* struct tid_ampdu_tx - TID aggregation information (Tx).
*
* @state: TID's state in session state machine.
* @dialog_token: dialog token for aggregation session
* @ssn: Starting Sequence Number expected to be aggregated.
* @addba_resp_timer: timer for peer's response to addba request
* @addba_req_num: number of times addBA request has been sent.
*/
struct tid_ampdu_tx {
u8 state;
u8 dialog_token;
u16 ssn;
struct timer_list addba_resp_timer;
u8 addba_req_num;
};
/**
* struct tid_ampdu_rx - TID aggregation information (Rx).
*
* @state: TID's state in session state machine.
* @dialog_token: dialog token for aggregation session
* @ssn: Starting Sequence Number expected to be aggregated.
* @buf_size: buffer size for incoming A-MPDUs
* @timeout: reset timer value.
* @head_seq_num: head sequence number in reordering buffer.
* @stored_mpdu_num: number of MPDUs in reordering buffer
* @reorder_buf: buffer to reorder incoming aggregated MPDUs
* @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
*/
struct tid_ampdu_rx {
u8 state;
u8 dialog_token;
u16 ssn;
u16 buf_size;
u16 timeout;
u16 head_seq_num;
u16 stored_mpdu_num;
struct sk_buff **reorder_buf;
struct timer_list session_timer;
};
enum plink_state {
LISTEN,
OPN_SNT,
OPN_RCVD,
CNF_RCVD,
ESTAB,
HOLDING,
BLOCKED
};
/**
* struct sta_ampdu_mlme - STA aggregation information.
*
* @tid_rx: aggregation info for Rx per TID
* @tid_tx: aggregation info for Tx per TID
* @ampdu_rx: for locking sections in aggregation Rx flow
* @ampdu_tx: for locking sectionsi in aggregation Tx flow
* @dialog_token_allocator: dialog token enumerator for each new session;
*/
struct sta_ampdu_mlme {
struct tid_ampdu_rx tid_rx[STA_TID_NUM];
struct tid_ampdu_tx tid_tx[STA_TID_NUM];
spinlock_t ampdu_rx;
spinlock_t ampdu_tx;
u8 dialog_token_allocator;
};
/* see __sta_info_unlink */
#define STA_INFO_PIN_STAT_NORMAL 0
#define STA_INFO_PIN_STAT_PINNED 1
#define STA_INFO_PIN_STAT_DESTROY 2
struct sta_info {
struct list_head list;
struct sta_info *hnext; /* next entry in hash table list */
struct ieee80211_local *local;
u8 addr[ETH_ALEN];
u16 aid; /* STA's unique AID (1..2007), 0 = not yet assigned */
u32 flags; /* WLAN_STA_ */
struct sk_buff_head ps_tx_buf; /* buffer of TX frames for station in
* power saving state */
struct sk_buff_head tx_filtered; /* buffer of TX frames that were
* already given to low-level driver,
* but were filtered */
unsigned long rx_packets, tx_packets; /* number of RX/TX MSDUs */
unsigned long rx_bytes, tx_bytes;
unsigned long tx_retry_failed, tx_retry_count;
unsigned long tx_filtered_count;
/* moving percentage of failed MSDUs */
unsigned int fail_avg;
unsigned int wep_weak_iv_count; /* number of RX frames with weak IV */
unsigned long last_rx;
/* bitmap of supported rates per band */
u64 supp_rates[IEEE80211_NUM_BANDS];
int txrate_idx;
/* last rates used to send a frame to this STA */
int last_txrate_idx, last_nonerp_txrate_idx;
/* sub_if_data this sta belongs to */
struct ieee80211_sub_if_data *sdata;
struct ieee80211_key *key;
u32 tx_num_consecutive_failures;
u32 tx_num_mpdu_ok;
u32 tx_num_mpdu_fail;
struct rate_control_ref *rate_ctrl;
void *rate_ctrl_priv;
/* last received seq/frag number from this STA (per RX queue) */
__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];
unsigned long num_duplicates; /* number of duplicate frames received
* from this STA */
unsigned long tx_fragments; /* number of transmitted MPDUs */
unsigned long rx_fragments; /* number of received MPDUs */
unsigned long rx_dropped; /* number of dropped MPDUs from this STA */
int last_rssi; /* RSSI of last received frame from this STA */
int last_signal; /* signal of last received frame from this STA */
int last_noise; /* noise of last received frame from this STA */
int channel_use;
int channel_use_raw;
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
unsigned int wme_rx_queue[NUM_RX_DATA_QUEUES];
unsigned int wme_tx_queue[NUM_RX_DATA_QUEUES];
#endif /* CONFIG_MAC80211_DEBUG_COUNTERS */
u16 listen_interval;
/*
* for use by the internal lifetime management,
* see __sta_info_unlink
*/
u8 pin_status;
struct ieee80211_ht_info ht_info; /* 802.11n HT capabilities
of this STA */
struct sta_ampdu_mlme ampdu_mlme;
u8 timer_to_tid[STA_TID_NUM]; /* convert timer id to tid */
u8 tid_to_tx_q[STA_TID_NUM]; /* map tid to tx queue */
#ifdef CONFIG_MAC80211_MESH
/* mesh peer link attributes */
__le16 llid; /* Local link ID */
__le16 plid; /* Peer link ID */
__le16 reason; /* Buffer for cancel reason on HOLDING state */
u8 plink_retries; /* Retries in establishment */
bool ignore_plink_timer;
enum plink_state plink_state;
u32 plink_timeout;
struct timer_list plink_timer;
spinlock_t plink_lock; /* For peer_state reads / updates and other
updates in the structure. Ensures robust
transitions for the peerlink FSM */
#endif
#ifdef CONFIG_MAC80211_DEBUGFS
struct sta_info_debugfsdentries {
struct dentry *dir;
struct dentry *flags;
struct dentry *num_ps_buf_frames;
struct dentry *inactive_ms;
struct dentry *last_seq_ctrl;
#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
struct dentry *wme_rx_queue;
struct dentry *wme_tx_queue;
#endif
struct dentry *agg_status;
} debugfs;
#endif
};
static inline enum plink_state sta_plink_state(struct sta_info *sta)
{
#ifdef CONFIG_MAC80211_MESH
return sta->plink_state;
#endif
return LISTEN;
}
/* Maximum number of concurrently registered stations */
#define MAX_STA_COUNT 2007
#define STA_HASH_SIZE 256
#define STA_HASH(sta) (sta[5])
/* Maximum number of frames to buffer per power saving station */
#define STA_MAX_TX_BUFFER 128
/* Minimum buffered frame expiry time. If STA uses listen interval that is
* smaller than this value, the minimum value here is used instead. */
#define STA_TX_BUFFER_EXPIRE (10 * HZ)
/* How often station data is cleaned up (e.g., expiration of buffered frames)
*/
#define STA_INFO_CLEANUP_INTERVAL (10 * HZ)
/*
* Get a STA info, must have be under RCU read lock.
*/
struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr);
/*
* Get STA info by index, BROKEN!
*/
struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx,
struct net_device *dev);
/*
* Add a new STA info, must be under RCU read lock
* because otherwise the returned reference isn't
* necessarily valid long enough.
*/
struct sta_info *sta_info_add(struct ieee80211_sub_if_data *sdata,
u8 *addr);
/*
* Unlink a STA info from the hash table/list.
* This can NULL the STA pointer if somebody else
* has already unlinked it.
*/
void sta_info_unlink(struct sta_info **sta);
void sta_info_destroy(struct sta_info *sta);
void sta_info_set_tim_bit(struct sta_info *sta);
void sta_info_clear_tim_bit(struct sta_info *sta);
void sta_info_init(struct ieee80211_local *local);
int sta_info_start(struct ieee80211_local *local);
void sta_info_stop(struct ieee80211_local *local);
void sta_info_flush(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata);
#endif /* STA_INFO_H */