#include <net/mac80211.h>
#include "ieee80211_i.h"
-#include "ieee80211_rate.h"
+#include "rate.h"
#include "sta_info.h"
#include "debugfs_sta.h"
#include "mesh.h"
* (which is pretty useless) or insert it into the hash table using
* sta_info_insert() which demotes the reference from ownership to a regular
* RCU-protected reference; if the function is called without protection by an
- * RCU critical section the reference is instantly invalidated.
+ * RCU critical section the reference is instantly invalidated. 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()!
*
* Because there are debugfs entries for each station, and adding those
* must be able to sleep, it is also possible to "pin" a station entry,
* that means it can be removed from the hash table but not be freed.
- * See the comment in __sta_info_unlink() for more information.
+ * See the comment in __sta_info_unlink() for more information, this is
+ * an internal capability only.
*
* In order to remove a STA info structure, the caller needs to first
* unlink it (sta_info_unlink()) from the list and hash tables and
- * then wait for an RCU synchronisation before it can be freed. Due to
- * the pinning and the possibility of multiple callers trying to remove
- * the same STA info at the same time, sta_info_unlink() can clear the
- * STA info pointer it is passed to indicate that the STA info is owned
- * by somebody else now.
+ * then destroy it; sta_info_destroy() will wait for an RCU grace period
+ * to elapse before actually freeing it. Due to the pinning and the
+ * possibility of multiple callers trying to remove the same STA info at
+ * the same time, sta_info_unlink() can clear the STA info pointer it is
+ * passed to indicate that the STA info is owned by somebody else now.
*
* If sta_info_unlink() did not clear the pointer then the caller owns
* the STA info structure now and is responsible of destroying it with
- * a call to sta_info_destroy(), not before RCU synchronisation, of
- * course. Note that sta_info_destroy() must be protected by the RTNL.
+ * a call to sta_info_destroy().
*
* In all other cases, there is no concept of ownership on a STA entry,
* each structure is owned by the global hash table/list until it is
int i = 0;
list_for_each_entry_rcu(sta, &local->sta_list, list) {
+ if (dev && dev != sta->sdata->dev)
+ continue;
if (i < idx) {
++i;
continue;
- } else if (!dev || dev == sta->sdata->dev) {
- return sta;
}
+ return sta;
}
return NULL;
}
+/**
+ * __sta_info_free - internal STA free helper
+ *
+ * @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)
+{
+ DECLARE_MAC_BUF(mbuf);
+
+ rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
+ rate_control_put(sta->rate_ctrl);
+
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+ printk(KERN_DEBUG "%s: Destroyed STA %s\n",
+ wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr));
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+
+ kfree(sta);
+}
+
void sta_info_destroy(struct sta_info *sta)
{
- struct ieee80211_local *local = sta->local;
+ struct ieee80211_local *local;
struct sk_buff *skb;
int i;
- DECLARE_MAC_BUF(mbuf);
+
+ might_sleep();
if (!sta)
return;
- ASSERT_RTNL();
- might_sleep();
+ local = sta->local;
rate_control_remove_sta_debugfs(sta);
ieee80211_sta_debugfs_remove(sta);
#endif
/*
- * NOTE: This will call synchronize_rcu() internally to
- * make sure no key references can be in use. We rely on
- * that here for the mesh code!
+ * 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_free(sta->key);
- WARN_ON(sta->key);
+ ieee80211_key_todo();
#ifdef CONFIG_MAC80211_MESH
if (ieee80211_vif_is_mesh(&sta->sdata->vif))
dev_kfree_skb_any(skb);
for (i = 0; i < STA_TID_NUM; i++) {
- del_timer_sync(&sta->ampdu_mlme.tid_rx[i].session_timer);
- del_timer_sync(&sta->ampdu_mlme.tid_tx[i].addba_resp_timer);
+ spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
+ if (sta->ampdu_mlme.tid_rx[i])
+ del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer);
+ spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
+ spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+ if (sta->ampdu_mlme.tid_tx[i])
+ del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer);
+ spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
}
- rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
- rate_control_put(sta->rate_ctrl);
-
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
- printk(KERN_DEBUG "%s: Destroyed STA %s\n",
- wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->addr));
-#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
- kfree(sta);
+ __sta_info_free(local, sta);
}
sta->timer_to_tid[i] = i;
/* tid to tx queue: initialize according to HW (0 is valid) */
sta->tid_to_tx_q[i] = local->hw.queues;
- /* rx timers */
- sta->ampdu_mlme.tid_rx[i].session_timer.function =
- sta_rx_agg_session_timer_expired;
- sta->ampdu_mlme.tid_rx[i].session_timer.data =
- (unsigned long)&sta->timer_to_tid[i];
- init_timer(&sta->ampdu_mlme.tid_rx[i].session_timer);
- /* tx timers */
- sta->ampdu_mlme.tid_tx[i].addba_resp_timer.function =
- sta_addba_resp_timer_expired;
- sta->ampdu_mlme.tid_tx[i].addba_resp_timer.data =
- (unsigned long)&sta->timer_to_tid[i];
- init_timer(&sta->ampdu_mlme.tid_tx[i].addba_resp_timer);
+ /* 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);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
#ifdef CONFIG_MAC80211_MESH
- sta->plink_state = LISTEN;
+ sta->plink_state = PLINK_LISTEN;
spin_lock_init(&sta->plink_lock);
init_timer(&sta->plink_timer);
#endif
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
unsigned long flags;
+ int err = 0;
DECLARE_MAC_BUF(mac);
/*
* something inserts a STA (on one CPU) without holding the RTNL
* and another CPU turns off the net device.
*/
- if (unlikely(!netif_running(sdata->dev)))
- return -ENETDOWN;
-
- if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0))
- return -EINVAL;
+ if (unlikely(!netif_running(sdata->dev))) {
+ err = -ENETDOWN;
+ goto out_free;
+ }
- if (WARN_ON(is_multicast_ether_addr(sta->addr)))
- return -EINVAL;
+ if (WARN_ON(compare_ether_addr(sta->addr, sdata->dev->dev_addr) == 0 ||
+ is_multicast_ether_addr(sta->addr))) {
+ err = -EINVAL;
+ goto out_free;
+ }
spin_lock_irqsave(&local->sta_lock, flags);
/* check if STA exists already */
if (__sta_info_find(local, sta->addr)) {
spin_unlock_irqrestore(&local->sta_lock, flags);
- return -EEXIST;
+ err = -EEXIST;
+ goto out_free;
}
list_add(&sta->list, &local->sta_list);
local->num_sta++;
spin_unlock_irqrestore(&local->sta_lock, flags);
#ifdef CONFIG_MAC80211_DEBUGFS
- /* debugfs entry adding might sleep, so schedule process
+ /*
+ * Debugfs entry adding might sleep, so schedule process
* context task for adding entry for STAs that do not yet
- * have one. */
- queue_work(local->hw.workqueue, &local->sta_debugfs_add);
+ * have one.
+ * NOTE: due to auto-freeing semantics this may only be done
+ * if the insertion is successful!
+ */
+ schedule_work(&local->sta_debugfs_add);
#endif
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;
}
static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
spin_unlock_irqrestore(&sta->local->sta_lock, flags);
}
-/*
- * See comment in __sta_info_unlink,
- * caller must hold local->sta_lock.
- */
-static void __sta_info_pin(struct sta_info *sta)
-{
- WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL);
- sta->pin_status = STA_INFO_PIN_STAT_PINNED;
-}
-
-/*
- * See comment in __sta_info_unlink, returns sta if it
- * needs to be destroyed.
- */
-static struct sta_info *__sta_info_unpin(struct sta_info *sta)
-{
- struct sta_info *ret = NULL;
- unsigned long flags;
-
- spin_lock_irqsave(&sta->local->sta_lock, flags);
- WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY &&
- sta->pin_status != STA_INFO_PIN_STAT_PINNED);
- if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY)
- ret = sta;
- sta->pin_status = STA_INFO_PIN_STAT_NORMAL;
- spin_unlock_irqrestore(&sta->local->sta_lock, flags);
-
- return ret;
-}
-
-static void __sta_info_unlink(struct sta_info **sta)
+void __sta_info_unlink(struct sta_info **sta)
{
struct ieee80211_local *local = (*sta)->local;
struct ieee80211_sub_if_data *sdata = (*sta)->sdata;
return;
}
- /*
- * Also pull caller's reference if the STA is pinned by the
- * task that is adding the debugfs entries. In that case, we
- * leave the STA "to be freed".
- *
- * The rules are not trivial, but not too complex either:
- * (1) pin_status is only modified under the sta_lock
- * (2) sta_info_debugfs_add_work() will set the status
- * to PINNED when it found an item that needs a new
- * debugfs directory created. In that case, that item
- * must not be freed although all *RCU* users are done
- * with it. Hence, we tell the caller of _unlink()
- * that the item is already gone (as can happen when
- * two tasks try to unlink/destroy at the same time)
- * (3) We set the pin_status to DESTROY here when we
- * find such an item.
- * (4) sta_info_debugfs_add_work() will reset the pin_status
- * from PINNED to NORMAL when it is done with the item,
- * but will check for DESTROY before resetting it in
- * which case it will free the item.
- */
- if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) {
- (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY;
- *sta = NULL;
- return;
+ if ((*sta)->key) {
+ ieee80211_key_free((*sta)->key);
+ WARN_ON((*sta)->key);
}
list_del(&(*sta)->list);
printk(KERN_DEBUG "%s: Removed STA %s\n",
wiphy_name(local->hw.wiphy), print_mac(mbuf, (*sta)->addr));
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+
+ /*
+ * Finally, pull caller's reference if the STA is pinned by the
+ * task that is adding the debugfs entries. In that case, we
+ * leave the STA "to be freed".
+ *
+ * The rules are not trivial, but not too complex either:
+ * (1) pin_status is only modified under the sta_lock
+ * (2) STAs may only be pinned under the RTNL so that
+ * sta_info_flush() is guaranteed to actually destroy
+ * all STAs that are active for a given interface, this
+ * is required for correctness because otherwise we
+ * could notify a driver that an interface is going
+ * away and only after that (!) notify it about a STA
+ * on that interface going away.
+ * (3) sta_info_debugfs_add_work() will set the status
+ * to PINNED when it found an item that needs a new
+ * debugfs directory created. In that case, that item
+ * must not be freed although all *RCU* users are done
+ * with it. Hence, we tell the caller of _unlink()
+ * that the item is already gone (as can happen when
+ * two tasks try to unlink/destroy at the same time)
+ * (4) We set the pin_status to DESTROY here when we
+ * find such an item.
+ * (5) sta_info_debugfs_add_work() will reset the pin_status
+ * from PINNED to NORMAL when it is done with the item,
+ * but will check for DESTROY before resetting it in
+ * which case it will free the item.
+ */
+ if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) {
+ (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY;
+ *sta = NULL;
+ return;
+ }
}
void sta_info_unlink(struct sta_info **sta)
}
#ifdef CONFIG_MAC80211_DEBUGFS
+/*
+ * See comment in __sta_info_unlink,
+ * caller must hold local->sta_lock.
+ */
+static void __sta_info_pin(struct sta_info *sta)
+{
+ WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL);
+ sta->pin_status = STA_INFO_PIN_STAT_PINNED;
+}
+
+/*
+ * See comment in __sta_info_unlink, returns sta if it
+ * needs to be destroyed.
+ */
+static struct sta_info *__sta_info_unpin(struct sta_info *sta)
+{
+ struct sta_info *ret = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sta->local->sta_lock, flags);
+ WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY &&
+ sta->pin_status != STA_INFO_PIN_STAT_PINNED);
+ if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY)
+ ret = sta;
+ sta->pin_status = STA_INFO_PIN_STAT_NORMAL;
+ spin_unlock_irqrestore(&sta->local->sta_lock, flags);
+
+ return ret;
+}
+
static void sta_info_debugfs_add_work(struct work_struct *work)
{
struct ieee80211_local *local =
struct sta_info *sta, *tmp;
unsigned long flags;
+ /* We need to keep the RTNL across the whole pinned status. */
+ rtnl_lock();
while (1) {
sta = NULL;
rate_control_add_sta_debugfs(sta);
sta = __sta_info_unpin(sta);
-
- if (sta) {
- synchronize_rcu();
- sta_info_destroy(sta);
- }
+ sta_info_destroy(sta);
}
+ rtnl_unlock();
}
#endif
+static void __ieee80211_run_pending_flush(struct ieee80211_local *local)
+{
+ struct sta_info *sta;
+ unsigned long flags;
+
+ ASSERT_RTNL();
+
+ spin_lock_irqsave(&local->sta_lock, flags);
+ while (!list_empty(&local->sta_flush_list)) {
+ sta = list_first_entry(&local->sta_flush_list,
+ struct sta_info, list);
+ list_del(&sta->list);
+ spin_unlock_irqrestore(&local->sta_lock, flags);
+ sta_info_destroy(sta);
+ spin_lock_irqsave(&local->sta_lock, flags);
+ }
+ spin_unlock_irqrestore(&local->sta_lock, flags);
+}
+
+static void ieee80211_sta_flush_work(struct work_struct *work)
+{
+ struct ieee80211_local *local =
+ container_of(work, struct ieee80211_local, sta_flush_work);
+
+ rtnl_lock();
+ __ieee80211_run_pending_flush(local);
+ rtnl_unlock();
+}
+
void sta_info_init(struct ieee80211_local *local)
{
spin_lock_init(&local->sta_lock);
INIT_LIST_HEAD(&local->sta_list);
+ INIT_LIST_HEAD(&local->sta_flush_list);
+ INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work);
setup_timer(&local->sta_cleanup, sta_info_cleanup,
(unsigned long)local);
void sta_info_stop(struct ieee80211_local *local)
{
del_timer(&local->sta_cleanup);
+ cancel_work_sync(&local->sta_flush_work);
+#ifdef CONFIG_MAC80211_DEBUGFS
+ /*
+ * Make sure the debugfs adding work isn't pending after this
+ * because we're about to be destroyed. It doesn't matter
+ * whether it ran or not since we're going to flush all STAs
+ * anyway.
+ */
+ cancel_work_sync(&local->sta_debugfs_add);
+#endif
+
+ rtnl_lock();
sta_info_flush(local, NULL);
+ __ieee80211_run_pending_flush(local);
+ rtnl_unlock();
}
/**
unsigned long flags;
might_sleep();
+ ASSERT_RTNL();
spin_lock_irqsave(&local->sta_lock, flags);
list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
}
spin_unlock_irqrestore(&local->sta_lock, flags);
- synchronize_rcu();
-
list_for_each_entry_safe(sta, tmp, &tmp_list, list)
sta_info_destroy(sta);
return ret;
}
+
+/**
+ * sta_info_flush_delayed - flush matching STA entries from the STA table
+ *
+ * This function unlinks all stations for a given interface and queues
+ * them for freeing. Note that the workqueue function scheduled here has
+ * to run before any new keys can be added to the system to avoid set_key()
+ * callback ordering issues.
+ *
+ * @sdata: the interface
+ */
+void sta_info_flush_delayed(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta, *tmp;
+ unsigned long flags;
+ bool work = false;
+
+ spin_lock_irqsave(&local->sta_lock, flags);
+ list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
+ if (sdata == sta->sdata) {
+ __sta_info_unlink(&sta);
+ if (sta) {
+ list_add_tail(&sta->list,
+ &local->sta_flush_list);
+ work = true;
+ }
+ }
+ }
+ if (work)
+ schedule_work(&local->sta_flush_work);
+ spin_unlock_irqrestore(&local->sta_lock, flags);
+}
git.openpandora.org / pandora-kernel.git / blobdiff