linux/net/mac80211/sta_info.c
Johannes Berg 34e895075e mac80211: allow station add/remove to sleep
Many drivers would like to sleep during station
addition and removal, and currently have a high
complexity there from not being able to.

This introduces two new callbacks sta_add() and
sta_remove() that drivers can implement instead
of using sta_notify() and that can sleep, and
the new sta_add() callback is also allowed to
fail.

The reason we didn't do this previously is that
the IBSS code wants to insert stations from the
RX path, which is a tasklet, so cannot sleep.
This patch will keep the station allocation in
that path, but moves adding the station to the
driver out of line. Since the addition can now
fail, we can have IBSS peer structs the driver
rejected -- in that case we still talk to the
station but never tell the driver about it in
the control.sta pointer. If there will ever be
a driver that has a low limit on the number of
stations and that cannot talk to any stations
that are not known to it, we need to do come up
with a new strategy of handling larger IBSSs,
maybe quicker expiry or rejecting peers.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-02-08 16:50:53 -05:00

988 lines
25 KiB
C

/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
*
* 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/timer.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "rate.h"
#include "sta_info.h"
#include "debugfs_sta.h"
#include "mesh.h"
/**
* DOC: STA information lifetime rules
*
* STA info structures (&struct sta_info) are managed in a hash table
* for faster lookup and a list for iteration. They are managed using
* RCU, i.e. access to the list and hash table is protected by RCU.
*
* Upon allocating a STA info structure with sta_info_alloc(), the caller
* owns that structure. It must then insert it into the hash table using
* either sta_info_insert() or sta_info_insert_rcu(); only in the latter
* case (which acquires an rcu read section but must not be called from
* within one) will the pointer still be valid after the call. Note that
* the caller may not do much with the STA info before inserting it, in
* particular, it may not start any mesh peer link management or add
* encryption keys.
*
* When the insertion fails (sta_info_insert()) returns non-zero), the
* structure will have been freed by sta_info_insert()!
*
* Station entries are added by mac80211 when you establish a link with a
* peer. This means different things for the different type of interfaces
* we support. For a regular station this mean we add the AP sta when we
* receive an assocation response from the AP. For IBSS this occurs when
* get to know about a peer on the same IBSS. For WDS we add the sta for
* the peer imediately upon device open. When using AP mode we add stations
* for each respective station upon request from userspace through nl80211.
*
* In order to remove a STA info structure, various sta_info_destroy_*()
* calls are available.
*
* There is no concept of ownership on a STA entry, each structure is
* owned by the global hash table/list until it is removed. All users of
* the structure need to be RCU protected so that the structure won't be
* freed before they are done using it.
*/
/* Caller must hold local->sta_lock */
static int sta_info_hash_del(struct ieee80211_local *local,
struct sta_info *sta)
{
struct sta_info *s;
s = local->sta_hash[STA_HASH(sta->sta.addr)];
if (!s)
return -ENOENT;
if (s == sta) {
rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
s->hnext);
return 0;
}
while (s->hnext && s->hnext != sta)
s = s->hnext;
if (s->hnext) {
rcu_assign_pointer(s->hnext, sta->hnext);
return 0;
}
return -ENOENT;
}
/* protected by RCU */
struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
const u8 *addr)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]);
while (sta) {
if (sta->sdata == sdata &&
memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
break;
sta = rcu_dereference(sta->hnext);
}
return sta;
}
/*
* Get sta info either from the specified interface
* or from one of its vlans
*/
struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
const u8 *addr)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]);
while (sta) {
if ((sta->sdata == sdata ||
sta->sdata->bss == sdata->bss) &&
memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
break;
sta = rcu_dereference(sta->hnext);
}
return sta;
}
struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
int idx)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
int i = 0;
list_for_each_entry_rcu(sta, &local->sta_list, list) {
if (sdata != sta->sdata)
continue;
if (i < idx) {
++i;
continue;
}
return sta;
}
return NULL;
}
/**
* __sta_info_free - internal STA free helper
*
* @local: pointer to the global information
* @sta: STA info to free
*
* This function must undo everything done by sta_info_alloc()
* that may happen before sta_info_insert().
*/
static void __sta_info_free(struct ieee80211_local *local,
struct sta_info *sta)
{
if (sta->rate_ctrl) {
rate_control_free_sta(sta);
rate_control_put(sta->rate_ctrl);
}
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Destroyed STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
kfree(sta);
}
/* Caller must hold local->sta_lock */
static void sta_info_hash_add(struct ieee80211_local *local,
struct sta_info *sta)
{
sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
}
static void sta_unblock(struct work_struct *wk)
{
struct sta_info *sta;
sta = container_of(wk, struct sta_info, drv_unblock_wk);
if (sta->dead)
return;
if (!test_sta_flags(sta, WLAN_STA_PS_STA))
ieee80211_sta_ps_deliver_wakeup(sta);
else if (test_and_clear_sta_flags(sta, WLAN_STA_PSPOLL))
ieee80211_sta_ps_deliver_poll_response(sta);
}
static int sta_prepare_rate_control(struct ieee80211_local *local,
struct sta_info *sta, gfp_t gfp)
{
if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
return 0;
sta->rate_ctrl = rate_control_get(local->rate_ctrl);
sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
&sta->sta, gfp);
if (!sta->rate_ctrl_priv) {
rate_control_put(sta->rate_ctrl);
return -ENOMEM;
}
return 0;
}
struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
u8 *addr, gfp_t gfp)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta;
int i;
sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
if (!sta)
return NULL;
spin_lock_init(&sta->lock);
spin_lock_init(&sta->flaglock);
INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
memcpy(sta->sta.addr, addr, ETH_ALEN);
sta->local = local;
sta->sdata = sdata;
if (sta_prepare_rate_control(local, sta, gfp)) {
kfree(sta);
return NULL;
}
for (i = 0; i < STA_TID_NUM; i++) {
/* timer_to_tid must be initialized with identity mapping to
* enable session_timer's data differentiation. refer to
* sta_rx_agg_session_timer_expired for useage */
sta->timer_to_tid[i] = i;
/* rx */
sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE;
sta->ampdu_mlme.tid_rx[i] = NULL;
/* tx */
sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE;
sta->ampdu_mlme.tid_tx[i] = NULL;
sta->ampdu_mlme.addba_req_num[i] = 0;
}
skb_queue_head_init(&sta->ps_tx_buf);
skb_queue_head_init(&sta->tx_filtered);
for (i = 0; i < NUM_RX_DATA_QUEUES; i++)
sta->last_seq_ctrl[i] = cpu_to_le16(USHORT_MAX);
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Allocated STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
#ifdef CONFIG_MAC80211_MESH
sta->plink_state = PLINK_LISTEN;
init_timer(&sta->plink_timer);
#endif
return sta;
}
static int sta_info_finish_insert(struct sta_info *sta, bool async)
{
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct station_info sinfo;
unsigned long flags;
int err = 0;
WARN_ON(!mutex_is_locked(&local->sta_mtx));
/* notify driver */
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
sdata = container_of(sdata->bss,
struct ieee80211_sub_if_data,
u.ap);
err = drv_sta_add(local, sdata, &sta->sta);
if (err) {
if (!async)
return err;
printk(KERN_DEBUG "%s: failed to add IBSS STA %pM to driver (%d)"
" - keeping it anyway.\n",
sdata->name, sta->sta.addr, err);
} else {
sta->uploaded = true;
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (async)
printk(KERN_DEBUG "%s: Finished adding IBSS STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif
}
sdata = sta->sdata;
if (!async) {
local->num_sta++;
local->sta_generation++;
smp_mb();
/* make the station visible */
spin_lock_irqsave(&local->sta_lock, flags);
sta_info_hash_add(local, sta);
spin_unlock_irqrestore(&local->sta_lock, flags);
}
list_add(&sta->list, &local->sta_list);
ieee80211_sta_debugfs_add(sta);
rate_control_add_sta_debugfs(sta);
sinfo.filled = 0;
sinfo.generation = local->sta_generation;
cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);
return 0;
}
static void sta_info_finish_pending(struct ieee80211_local *local)
{
struct sta_info *sta;
unsigned long flags;
spin_lock_irqsave(&local->sta_lock, flags);
while (!list_empty(&local->sta_pending_list)) {
sta = list_first_entry(&local->sta_pending_list,
struct sta_info, list);
list_del(&sta->list);
spin_unlock_irqrestore(&local->sta_lock, flags);
sta_info_finish_insert(sta, true);
spin_lock_irqsave(&local->sta_lock, flags);
}
spin_unlock_irqrestore(&local->sta_lock, flags);
}
static void sta_info_finish_work(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, sta_finish_work);
mutex_lock(&local->sta_mtx);
sta_info_finish_pending(local);
mutex_unlock(&local->sta_mtx);
}
int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
{
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
unsigned long flags;
int err = 0;
/*
* Can't be a WARN_ON because it can be triggered through a race:
* something inserts a STA (on one CPU) without holding the RTNL
* and another CPU turns off the net device.
*/
if (unlikely(!ieee80211_sdata_running(sdata))) {
err = -ENETDOWN;
rcu_read_lock();
goto out_free;
}
if (WARN_ON(compare_ether_addr(sta->sta.addr, sdata->vif.addr) == 0 ||
is_multicast_ether_addr(sta->sta.addr))) {
err = -EINVAL;
rcu_read_lock();
goto out_free;
}
/*
* In ad-hoc mode, we sometimes need to insert stations
* from tasklet context from the RX path. To avoid races,
* always do so in that case -- see the comment below.
*/
if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
spin_lock_irqsave(&local->sta_lock, flags);
/* check if STA exists already */
if (sta_info_get_bss(sdata, sta->sta.addr)) {
spin_unlock_irqrestore(&local->sta_lock, flags);
rcu_read_lock();
err = -EEXIST;
goto out_free;
}
local->num_sta++;
local->sta_generation++;
smp_mb();
sta_info_hash_add(local, sta);
list_add_tail(&sta->list, &local->sta_pending_list);
rcu_read_lock();
spin_unlock_irqrestore(&local->sta_lock, flags);
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Added IBSS STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
ieee80211_queue_work(&local->hw, &local->sta_finish_work);
return 0;
}
/*
* On first glance, this will look racy, because the code
* below this point, which inserts a station with sleeping,
* unlocks the sta_lock between checking existence in the
* hash table and inserting into it.
*
* However, it is not racy against itself because it keeps
* the mutex locked. It still seems to race against the
* above code that atomically inserts the station... That,
* however, is not true because the above code can only
* be invoked for IBSS interfaces, and the below code will
* not be -- and the two do not race against each other as
* the hash table also keys off the interface.
*/
might_sleep();
mutex_lock(&local->sta_mtx);
spin_lock_irqsave(&local->sta_lock, flags);
/* check if STA exists already */
if (sta_info_get_bss(sdata, sta->sta.addr)) {
spin_unlock_irqrestore(&local->sta_lock, flags);
rcu_read_lock();
err = -EEXIST;
goto out_free;
}
spin_unlock_irqrestore(&local->sta_lock, flags);
err = sta_info_finish_insert(sta, false);
if (err) {
mutex_unlock(&local->sta_mtx);
rcu_read_lock();
goto out_free;
}
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Inserted STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
/* move reference to rcu-protected */
rcu_read_lock();
mutex_unlock(&local->sta_mtx);
if (ieee80211_vif_is_mesh(&sdata->vif))
mesh_accept_plinks_update(sdata);
return 0;
out_free:
BUG_ON(!err);
__sta_info_free(local, sta);
return err;
}
int sta_info_insert(struct sta_info *sta)
{
int err = sta_info_insert_rcu(sta);
rcu_read_unlock();
return err;
}
static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
{
/*
* This format has been mandated by the IEEE specifications,
* so this line may not be changed to use the __set_bit() format.
*/
bss->tim[aid / 8] |= (1 << (aid % 8));
}
static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
{
/*
* This format has been mandated by the IEEE specifications,
* so this line may not be changed to use the __clear_bit() format.
*/
bss->tim[aid / 8] &= ~(1 << (aid % 8));
}
static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss,
struct sta_info *sta)
{
BUG_ON(!bss);
__bss_tim_set(bss, sta->sta.aid);
if (sta->local->ops->set_tim) {
sta->local->tim_in_locked_section = true;
drv_set_tim(sta->local, &sta->sta, true);
sta->local->tim_in_locked_section = false;
}
}
void sta_info_set_tim_bit(struct sta_info *sta)
{
unsigned long flags;
BUG_ON(!sta->sdata->bss);
spin_lock_irqsave(&sta->local->sta_lock, flags);
__sta_info_set_tim_bit(sta->sdata->bss, sta);
spin_unlock_irqrestore(&sta->local->sta_lock, flags);
}
static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss,
struct sta_info *sta)
{
BUG_ON(!bss);
__bss_tim_clear(bss, sta->sta.aid);
if (sta->local->ops->set_tim) {
sta->local->tim_in_locked_section = true;
drv_set_tim(sta->local, &sta->sta, false);
sta->local->tim_in_locked_section = false;
}
}
void sta_info_clear_tim_bit(struct sta_info *sta)
{
unsigned long flags;
BUG_ON(!sta->sdata->bss);
spin_lock_irqsave(&sta->local->sta_lock, flags);
__sta_info_clear_tim_bit(sta->sdata->bss, sta);
spin_unlock_irqrestore(&sta->local->sta_lock, flags);
}
static int sta_info_buffer_expired(struct sta_info *sta,
struct sk_buff *skb)
{
struct ieee80211_tx_info *info;
int timeout;
if (!skb)
return 0;
info = IEEE80211_SKB_CB(skb);
/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
timeout = (sta->listen_interval *
sta->sdata->vif.bss_conf.beacon_int *
32 / 15625) * HZ;
if (timeout < STA_TX_BUFFER_EXPIRE)
timeout = STA_TX_BUFFER_EXPIRE;
return time_after(jiffies, info->control.jiffies + timeout);
}
static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
struct sta_info *sta)
{
unsigned long flags;
struct sk_buff *skb;
struct ieee80211_sub_if_data *sdata;
if (skb_queue_empty(&sta->ps_tx_buf))
return;
for (;;) {
spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
skb = skb_peek(&sta->ps_tx_buf);
if (sta_info_buffer_expired(sta, skb))
skb = __skb_dequeue(&sta->ps_tx_buf);
else
skb = NULL;
spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
if (!skb)
break;
sdata = sta->sdata;
local->total_ps_buffered--;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "Buffered frame expired (STA %pM)\n",
sta->sta.addr);
#endif
dev_kfree_skb(skb);
if (skb_queue_empty(&sta->ps_tx_buf))
sta_info_clear_tim_bit(sta);
}
}
static int __must_check __sta_info_destroy(struct sta_info *sta)
{
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
struct sk_buff *skb;
unsigned long flags;
int ret, i;
might_sleep();
if (!sta)
return -ENOENT;
local = sta->local;
sdata = sta->sdata;
spin_lock_irqsave(&local->sta_lock, flags);
ret = sta_info_hash_del(local, sta);
/* this might still be the pending list ... which is fine */
if (!ret)
list_del(&sta->list);
spin_unlock_irqrestore(&local->sta_lock, flags);
if (ret)
return ret;
if (sta->key) {
ieee80211_key_free(sta->key);
/*
* We have only unlinked the key, and actually destroying it
* may mean it is removed from hardware which requires that
* the key->sta pointer is still valid, so flush the key todo
* list here.
*
* ieee80211_key_todo() will synchronize_rcu() so after this
* nothing can reference this sta struct any more.
*/
ieee80211_key_todo();
WARN_ON(sta->key);
}
sta->dead = true;
if (test_and_clear_sta_flags(sta,
WLAN_STA_PS_STA | WLAN_STA_PS_DRIVER)) {
BUG_ON(!sdata->bss);
atomic_dec(&sdata->bss->num_sta_ps);
__sta_info_clear_tim_bit(sdata->bss, sta);
}
local->num_sta--;
local->sta_generation++;
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
rcu_assign_pointer(sdata->u.vlan.sta, NULL);
if (sta->uploaded) {
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
sdata = container_of(sdata->bss,
struct ieee80211_sub_if_data,
u.ap);
drv_sta_remove(local, sdata, &sta->sta);
sdata = sta->sdata;
}
#ifdef CONFIG_MAC80211_MESH
if (ieee80211_vif_is_mesh(&sdata->vif)) {
mesh_accept_plinks_update(sdata);
del_timer(&sta->plink_timer);
}
#endif
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: Removed STA %pM\n",
wiphy_name(local->hw.wiphy), sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
cancel_work_sync(&sta->drv_unblock_wk);
rate_control_remove_sta_debugfs(sta);
ieee80211_sta_debugfs_remove(sta);
#ifdef CONFIG_MAC80211_MESH
if (ieee80211_vif_is_mesh(&sta->sdata->vif)) {
mesh_plink_deactivate(sta);
del_timer_sync(&sta->plink_timer);
}
#endif
while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
local->total_ps_buffered--;
dev_kfree_skb_any(skb);
}
while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL)
dev_kfree_skb_any(skb);
for (i = 0; i < STA_TID_NUM; i++) {
struct tid_ampdu_rx *tid_rx;
struct tid_ampdu_tx *tid_tx;
spin_lock_bh(&sta->lock);
tid_rx = sta->ampdu_mlme.tid_rx[i];
/* Make sure timer won't free the tid_rx struct, see below */
if (tid_rx)
tid_rx->shutdown = true;
spin_unlock_bh(&sta->lock);
/*
* Outside spinlock - shutdown is true now so that the timer
* won't free tid_rx, we have to do that now. Can't let the
* timer do it because we have to sync the timer outside the
* lock that it takes itself.
*/
if (tid_rx) {
del_timer_sync(&tid_rx->session_timer);
kfree(tid_rx);
}
/*
* No need to do such complications for TX agg sessions, the
* path leading to freeing the tid_tx struct goes via a call
* from the driver, and thus needs to look up the sta struct
* again, which cannot be found when we get here. Hence, we
* just need to delete the timer and free the aggregation
* info; we won't be telling the peer about it then but that
* doesn't matter if we're not talking to it again anyway.
*/
tid_tx = sta->ampdu_mlme.tid_tx[i];
if (tid_tx) {
del_timer_sync(&tid_tx->addba_resp_timer);
/*
* STA removed while aggregation session being
* started? Bit odd, but purge frames anyway.
*/
skb_queue_purge(&tid_tx->pending);
kfree(tid_tx);
}
}
__sta_info_free(local, sta);
return 0;
}
int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr)
{
struct sta_info *sta;
int ret;
mutex_lock(&sdata->local->sta_mtx);
sta = sta_info_get(sdata, addr);
ret = __sta_info_destroy(sta);
mutex_unlock(&sdata->local->sta_mtx);
return ret;
}
int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
const u8 *addr)
{
struct sta_info *sta;
int ret;
mutex_lock(&sdata->local->sta_mtx);
sta = sta_info_get_bss(sdata, addr);
ret = __sta_info_destroy(sta);
mutex_unlock(&sdata->local->sta_mtx);
return ret;
}
static void sta_info_cleanup(unsigned long data)
{
struct ieee80211_local *local = (struct ieee80211_local *) data;
struct sta_info *sta;
rcu_read_lock();
list_for_each_entry_rcu(sta, &local->sta_list, list)
sta_info_cleanup_expire_buffered(local, sta);
rcu_read_unlock();
if (local->quiescing)
return;
local->sta_cleanup.expires =
round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
add_timer(&local->sta_cleanup);
}
void sta_info_init(struct ieee80211_local *local)
{
spin_lock_init(&local->sta_lock);
mutex_init(&local->sta_mtx);
INIT_LIST_HEAD(&local->sta_list);
INIT_LIST_HEAD(&local->sta_pending_list);
INIT_WORK(&local->sta_finish_work, sta_info_finish_work);
setup_timer(&local->sta_cleanup, sta_info_cleanup,
(unsigned long)local);
local->sta_cleanup.expires =
round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
}
int sta_info_start(struct ieee80211_local *local)
{
add_timer(&local->sta_cleanup);
return 0;
}
void sta_info_stop(struct ieee80211_local *local)
{
del_timer(&local->sta_cleanup);
sta_info_flush(local, NULL);
}
/**
* sta_info_flush - flush matching STA entries from the STA table
*
* Returns the number of removed STA entries.
*
* @local: local interface data
* @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
*/
int sta_info_flush(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata)
{
struct sta_info *sta, *tmp;
int ret = 0;
might_sleep();
mutex_lock(&local->sta_mtx);
sta_info_finish_pending(local);
list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
if (!sdata || sdata == sta->sdata)
WARN_ON(__sta_info_destroy(sta));
}
mutex_unlock(&local->sta_mtx);
return ret;
}
void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
unsigned long exp_time)
{
struct ieee80211_local *local = sdata->local;
struct sta_info *sta, *tmp;
mutex_lock(&local->sta_mtx);
list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
if (time_after(jiffies, sta->last_rx + exp_time)) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
printk(KERN_DEBUG "%s: expiring inactive STA %pM\n",
sdata->name, sta->sta.addr);
#endif
WARN_ON(__sta_info_destroy(sta));
}
mutex_unlock(&local->sta_mtx);
}
struct ieee80211_sta *ieee80211_find_sta_by_hw(struct ieee80211_hw *hw,
const u8 *addr)
{
struct sta_info *sta, *nxt;
/* Just return a random station ... first in list ... */
for_each_sta_info(hw_to_local(hw), addr, sta, nxt)
return &sta->sta;
return NULL;
}
EXPORT_SYMBOL_GPL(ieee80211_find_sta_by_hw);
struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif,
const u8 *addr)
{
struct ieee80211_sub_if_data *sdata;
if (!vif)
return NULL;
sdata = vif_to_sdata(vif);
return ieee80211_find_sta_by_hw(&sdata->local->hw, addr);
}
EXPORT_SYMBOL(ieee80211_find_sta);
/* powersave support code */
void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
int sent, buffered;
drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);
if (!skb_queue_empty(&sta->ps_tx_buf))
sta_info_clear_tim_bit(sta);
/* Send all buffered frames to the station */
sent = ieee80211_add_pending_skbs(local, &sta->tx_filtered);
buffered = ieee80211_add_pending_skbs(local, &sta->ps_tx_buf);
sent += buffered;
local->total_ps_buffered -= buffered;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "%s: STA %pM aid %d sending %d filtered/%d PS frames "
"since STA not sleeping anymore\n", sdata->name,
sta->sta.addr, sta->sta.aid, sent - buffered, buffered);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}
void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb;
int no_pending_pkts;
skb = skb_dequeue(&sta->tx_filtered);
if (!skb) {
skb = skb_dequeue(&sta->ps_tx_buf);
if (skb)
local->total_ps_buffered--;
}
no_pending_pkts = skb_queue_empty(&sta->tx_filtered) &&
skb_queue_empty(&sta->ps_tx_buf);
if (skb) {
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr =
(struct ieee80211_hdr *) skb->data;
/*
* Tell TX path to send this frame even though the STA may
* still remain is PS mode after this frame exchange.
*/
info->flags |= IEEE80211_TX_CTL_PSPOLL_RESPONSE;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
printk(KERN_DEBUG "STA %pM aid %d: PS Poll (entries after %d)\n",
sta->sta.addr, sta->sta.aid,
skb_queue_len(&sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
/* Use MoreData flag to indicate whether there are more
* buffered frames for this STA */
if (no_pending_pkts)
hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
else
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);
ieee80211_add_pending_skb(local, skb);
if (no_pending_pkts)
sta_info_clear_tim_bit(sta);
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
} else {
/*
* FIXME: This can be the result of a race condition between
* us expiring a frame and the station polling for it.
* Should we send it a null-func frame indicating we
* have nothing buffered for it?
*/
printk(KERN_DEBUG "%s: STA %pM sent PS Poll even "
"though there are no buffered frames for it\n",
sdata->name, sta->sta.addr);
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}
}
void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
struct ieee80211_sta *pubsta, bool block)
{
struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
if (block)
set_sta_flags(sta, WLAN_STA_PS_DRIVER);
else
ieee80211_queue_work(hw, &sta->drv_unblock_wk);
}
EXPORT_SYMBOL(ieee80211_sta_block_awake);