2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/netdevice.h>
13 #include <linux/types.h>
14 #include <linux/slab.h>
15 #include <linux/skbuff.h>
16 #include <linux/if_arp.h>
17 #include <linux/timer.h>
18 #include <linux/rtnetlink.h>
20 #include <net/mac80211.h>
21 #include "ieee80211_i.h"
24 #include "debugfs_sta.h"
28 * DOC: STA information lifetime rules
30 * STA info structures (&struct sta_info) are managed in a hash table
31 * for faster lookup and a list for iteration. They are managed using
32 * RCU, i.e. access to the list and hash table is protected by RCU.
34 * Upon allocating a STA info structure with sta_info_alloc(), the caller owns
35 * that structure. It must then either destroy it using sta_info_destroy()
36 * (which is pretty useless) or insert it into the hash table using
37 * sta_info_insert() which demotes the reference from ownership to a regular
38 * RCU-protected reference; if the function is called without protection by an
39 * RCU critical section the reference is instantly invalidated. Note that the
40 * caller may not do much with the STA info before inserting it, in particular,
41 * it may not start any mesh peer link management or add encryption keys.
43 * When the insertion fails (sta_info_insert()) returns non-zero), the
44 * structure will have been freed by sta_info_insert()!
46 * Because there are debugfs entries for each station, and adding those
47 * must be able to sleep, it is also possible to "pin" a station entry,
48 * that means it can be removed from the hash table but not be freed.
49 * See the comment in __sta_info_unlink() for more information, this is
50 * an internal capability only.
52 * In order to remove a STA info structure, the caller needs to first
53 * unlink it (sta_info_unlink()) from the list and hash tables and
54 * then destroy it; sta_info_destroy() will wait for an RCU grace period
55 * to elapse before actually freeing it. Due to the pinning and the
56 * possibility of multiple callers trying to remove the same STA info at
57 * the same time, sta_info_unlink() can clear the STA info pointer it is
58 * passed to indicate that the STA info is owned by somebody else now.
60 * If sta_info_unlink() did not clear the pointer then the caller owns
61 * the STA info structure now and is responsible of destroying it with
62 * a call to sta_info_destroy().
64 * In all other cases, there is no concept of ownership on a STA entry,
65 * each structure is owned by the global hash table/list until it is
66 * removed. All users of the structure need to be RCU protected so that
67 * the structure won't be freed before they are done using it.
70 /* Caller must hold local->sta_lock */
71 static int sta_info_hash_del(struct ieee80211_local *local,
76 s = local->sta_hash[STA_HASH(sta->sta.addr)];
80 rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
85 while (s->hnext && s->hnext != sta)
88 rcu_assign_pointer(s->hnext, sta->hnext);
95 /* protected by RCU */
96 struct sta_info *sta_info_get(struct ieee80211_local *local, const u8 *addr)
100 sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]);
102 if (memcmp(sta->sta.addr, addr, ETH_ALEN) == 0)
104 sta = rcu_dereference(sta->hnext);
109 struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx,
110 struct net_device *dev)
112 struct sta_info *sta;
115 list_for_each_entry_rcu(sta, &local->sta_list, list) {
116 if (dev && dev != sta->sdata->dev)
129 * __sta_info_free - internal STA free helper
131 * @local: pointer to the global information
132 * @sta: STA info to free
134 * This function must undo everything done by sta_info_alloc()
135 * that may happen before sta_info_insert().
137 static void __sta_info_free(struct ieee80211_local *local,
138 struct sta_info *sta)
140 rate_control_free_sta(sta);
141 rate_control_put(sta->rate_ctrl);
143 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
144 printk(KERN_DEBUG "%s: Destroyed STA %pM\n",
145 wiphy_name(local->hw.wiphy), sta->sta.addr);
146 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
151 void sta_info_destroy(struct sta_info *sta)
153 struct ieee80211_local *local;
164 rate_control_remove_sta_debugfs(sta);
165 ieee80211_sta_debugfs_remove(sta);
167 #ifdef CONFIG_MAC80211_MESH
168 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
169 mesh_plink_deactivate(sta);
173 * We have only unlinked the key, and actually destroying it
174 * may mean it is removed from hardware which requires that
175 * the key->sta pointer is still valid, so flush the key todo
178 * ieee80211_key_todo() will synchronize_rcu() so after this
179 * nothing can reference this sta struct any more.
181 ieee80211_key_todo();
183 #ifdef CONFIG_MAC80211_MESH
184 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
185 del_timer_sync(&sta->plink_timer);
188 while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
189 local->total_ps_buffered--;
190 dev_kfree_skb_any(skb);
193 while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL)
194 dev_kfree_skb_any(skb);
196 for (i = 0; i < STA_TID_NUM; i++) {
197 struct tid_ampdu_rx *tid_rx;
198 struct tid_ampdu_tx *tid_tx;
200 spin_lock_bh(&sta->lock);
201 tid_rx = sta->ampdu_mlme.tid_rx[i];
202 /* Make sure timer won't free the tid_rx struct, see below */
204 tid_rx->shutdown = true;
207 * The stop callback cannot find this station any more, but
208 * it didn't complete its work -- start the queue if necessary
210 if (sta->ampdu_mlme.tid_state_tx[i] & HT_AGG_STATE_INITIATOR_MSK &&
211 sta->ampdu_mlme.tid_state_tx[i] & HT_AGG_STATE_REQ_STOP_BA_MSK &&
212 local->hw.ampdu_queues)
213 ieee80211_wake_queue_by_reason(&local->hw,
214 local->hw.queues + sta->tid_to_tx_q[i],
215 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
217 spin_unlock_bh(&sta->lock);
220 * Outside spinlock - shutdown is true now so that the timer
221 * won't free tid_rx, we have to do that now. Can't let the
222 * timer do it because we have to sync the timer outside the
223 * lock that it takes itself.
226 del_timer_sync(&tid_rx->session_timer);
231 * No need to do such complications for TX agg sessions, the
232 * path leading to freeing the tid_tx struct goes via a call
233 * from the driver, and thus needs to look up the sta struct
234 * again, which cannot be found when we get here. Hence, we
235 * just need to delete the timer and free the aggregation
236 * info; we won't be telling the peer about it then but that
237 * doesn't matter if we're not talking to it again anyway.
239 tid_tx = sta->ampdu_mlme.tid_tx[i];
241 del_timer_sync(&tid_tx->addba_resp_timer);
243 * STA removed while aggregation session being
244 * started? Bit odd, but purge frames anyway.
246 skb_queue_purge(&tid_tx->pending);
251 __sta_info_free(local, sta);
255 /* Caller must hold local->sta_lock */
256 static void sta_info_hash_add(struct ieee80211_local *local,
257 struct sta_info *sta)
259 sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
260 rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
263 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
266 struct ieee80211_local *local = sdata->local;
267 struct sta_info *sta;
270 sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
274 spin_lock_init(&sta->lock);
275 spin_lock_init(&sta->flaglock);
277 memcpy(sta->sta.addr, addr, ETH_ALEN);
281 sta->rate_ctrl = rate_control_get(local->rate_ctrl);
282 sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
284 if (!sta->rate_ctrl_priv) {
285 rate_control_put(sta->rate_ctrl);
290 for (i = 0; i < STA_TID_NUM; i++) {
291 /* timer_to_tid must be initialized with identity mapping to
292 * enable session_timer's data differentiation. refer to
293 * sta_rx_agg_session_timer_expired for useage */
294 sta->timer_to_tid[i] = i;
295 sta->tid_to_tx_q[i] = -1;
297 sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE;
298 sta->ampdu_mlme.tid_rx[i] = NULL;
300 sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE;
301 sta->ampdu_mlme.tid_tx[i] = NULL;
302 sta->ampdu_mlme.addba_req_num[i] = 0;
304 skb_queue_head_init(&sta->ps_tx_buf);
305 skb_queue_head_init(&sta->tx_filtered);
307 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
308 printk(KERN_DEBUG "%s: Allocated STA %pM\n",
309 wiphy_name(local->hw.wiphy), sta->sta.addr);
310 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
312 #ifdef CONFIG_MAC80211_MESH
313 sta->plink_state = PLINK_LISTEN;
314 init_timer(&sta->plink_timer);
320 int sta_info_insert(struct sta_info *sta)
322 struct ieee80211_local *local = sta->local;
323 struct ieee80211_sub_if_data *sdata = sta->sdata;
328 * Can't be a WARN_ON because it can be triggered through a race:
329 * something inserts a STA (on one CPU) without holding the RTNL
330 * and another CPU turns off the net device.
332 if (unlikely(!netif_running(sdata->dev))) {
337 if (WARN_ON(compare_ether_addr(sta->sta.addr, sdata->dev->dev_addr) == 0 ||
338 is_multicast_ether_addr(sta->sta.addr))) {
343 spin_lock_irqsave(&local->sta_lock, flags);
344 /* check if STA exists already */
345 if (sta_info_get(local, sta->sta.addr)) {
346 spin_unlock_irqrestore(&local->sta_lock, flags);
350 list_add(&sta->list, &local->sta_list);
352 sta_info_hash_add(local, sta);
355 if (local->ops->sta_notify) {
356 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
357 sdata = container_of(sdata->bss,
358 struct ieee80211_sub_if_data,
361 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
362 STA_NOTIFY_ADD, &sta->sta);
365 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
366 printk(KERN_DEBUG "%s: Inserted STA %pM\n",
367 wiphy_name(local->hw.wiphy), sta->sta.addr);
368 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
370 spin_unlock_irqrestore(&local->sta_lock, flags);
372 #ifdef CONFIG_MAC80211_DEBUGFS
374 * Debugfs entry adding might sleep, so schedule process
375 * context task for adding entry for STAs that do not yet
377 * NOTE: due to auto-freeing semantics this may only be done
378 * if the insertion is successful!
380 schedule_work(&local->sta_debugfs_add);
383 if (ieee80211_vif_is_mesh(&sdata->vif))
384 mesh_accept_plinks_update(sdata);
389 __sta_info_free(local, sta);
393 static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
396 * This format has been mandated by the IEEE specifications,
397 * so this line may not be changed to use the __set_bit() format.
399 bss->tim[aid / 8] |= (1 << (aid % 8));
402 static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
405 * This format has been mandated by the IEEE specifications,
406 * so this line may not be changed to use the __clear_bit() format.
408 bss->tim[aid / 8] &= ~(1 << (aid % 8));
411 static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss,
412 struct sta_info *sta)
416 __bss_tim_set(bss, sta->sta.aid);
418 if (sta->local->ops->set_tim) {
419 sta->local->tim_in_locked_section = true;
420 sta->local->ops->set_tim(local_to_hw(sta->local),
422 sta->local->tim_in_locked_section = false;
426 void sta_info_set_tim_bit(struct sta_info *sta)
430 BUG_ON(!sta->sdata->bss);
432 spin_lock_irqsave(&sta->local->sta_lock, flags);
433 __sta_info_set_tim_bit(sta->sdata->bss, sta);
434 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
437 static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss,
438 struct sta_info *sta)
442 __bss_tim_clear(bss, sta->sta.aid);
444 if (sta->local->ops->set_tim) {
445 sta->local->tim_in_locked_section = true;
446 sta->local->ops->set_tim(local_to_hw(sta->local),
448 sta->local->tim_in_locked_section = false;
452 void sta_info_clear_tim_bit(struct sta_info *sta)
456 BUG_ON(!sta->sdata->bss);
458 spin_lock_irqsave(&sta->local->sta_lock, flags);
459 __sta_info_clear_tim_bit(sta->sdata->bss, sta);
460 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
463 static void __sta_info_unlink(struct sta_info **sta)
465 struct ieee80211_local *local = (*sta)->local;
466 struct ieee80211_sub_if_data *sdata = (*sta)->sdata;
468 * pull caller's reference if we're already gone.
470 if (sta_info_hash_del(local, *sta)) {
476 ieee80211_key_free((*sta)->key);
477 WARN_ON((*sta)->key);
480 list_del(&(*sta)->list);
482 if (test_and_clear_sta_flags(*sta, WLAN_STA_PS)) {
485 atomic_dec(&sdata->bss->num_sta_ps);
486 __sta_info_clear_tim_bit(sdata->bss, *sta);
491 if (local->ops->sta_notify) {
492 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
493 sdata = container_of(sdata->bss,
494 struct ieee80211_sub_if_data,
497 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
498 STA_NOTIFY_REMOVE, &(*sta)->sta);
501 if (ieee80211_vif_is_mesh(&sdata->vif)) {
502 mesh_accept_plinks_update(sdata);
503 #ifdef CONFIG_MAC80211_MESH
504 del_timer(&(*sta)->plink_timer);
508 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
509 printk(KERN_DEBUG "%s: Removed STA %pM\n",
510 wiphy_name(local->hw.wiphy), (*sta)->sta.addr);
511 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
514 * Finally, pull caller's reference if the STA is pinned by the
515 * task that is adding the debugfs entries. In that case, we
516 * leave the STA "to be freed".
518 * The rules are not trivial, but not too complex either:
519 * (1) pin_status is only modified under the sta_lock
520 * (2) STAs may only be pinned under the RTNL so that
521 * sta_info_flush() is guaranteed to actually destroy
522 * all STAs that are active for a given interface, this
523 * is required for correctness because otherwise we
524 * could notify a driver that an interface is going
525 * away and only after that (!) notify it about a STA
526 * on that interface going away.
527 * (3) sta_info_debugfs_add_work() will set the status
528 * to PINNED when it found an item that needs a new
529 * debugfs directory created. In that case, that item
530 * must not be freed although all *RCU* users are done
531 * with it. Hence, we tell the caller of _unlink()
532 * that the item is already gone (as can happen when
533 * two tasks try to unlink/destroy at the same time)
534 * (4) We set the pin_status to DESTROY here when we
536 * (5) sta_info_debugfs_add_work() will reset the pin_status
537 * from PINNED to NORMAL when it is done with the item,
538 * but will check for DESTROY before resetting it in
539 * which case it will free the item.
541 if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) {
542 (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY;
548 void sta_info_unlink(struct sta_info **sta)
550 struct ieee80211_local *local = (*sta)->local;
553 spin_lock_irqsave(&local->sta_lock, flags);
554 __sta_info_unlink(sta);
555 spin_unlock_irqrestore(&local->sta_lock, flags);
558 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
559 struct sta_info *sta,
562 struct ieee80211_tx_info *info;
568 info = IEEE80211_SKB_CB(skb);
570 /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
571 timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
573 if (timeout < STA_TX_BUFFER_EXPIRE)
574 timeout = STA_TX_BUFFER_EXPIRE;
575 return time_after(jiffies, info->control.jiffies + timeout);
579 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
580 struct sta_info *sta)
584 struct ieee80211_sub_if_data *sdata;
586 if (skb_queue_empty(&sta->ps_tx_buf))
590 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
591 skb = skb_peek(&sta->ps_tx_buf);
592 if (sta_info_buffer_expired(local, sta, skb))
593 skb = __skb_dequeue(&sta->ps_tx_buf);
596 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
602 local->total_ps_buffered--;
603 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
604 printk(KERN_DEBUG "Buffered frame expired (STA %pM)\n",
609 if (skb_queue_empty(&sta->ps_tx_buf))
610 sta_info_clear_tim_bit(sta);
615 static void sta_info_cleanup(unsigned long data)
617 struct ieee80211_local *local = (struct ieee80211_local *) data;
618 struct sta_info *sta;
621 list_for_each_entry_rcu(sta, &local->sta_list, list)
622 sta_info_cleanup_expire_buffered(local, sta);
625 local->sta_cleanup.expires =
626 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
627 add_timer(&local->sta_cleanup);
630 #ifdef CONFIG_MAC80211_DEBUGFS
632 * See comment in __sta_info_unlink,
633 * caller must hold local->sta_lock.
635 static void __sta_info_pin(struct sta_info *sta)
637 WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL);
638 sta->pin_status = STA_INFO_PIN_STAT_PINNED;
642 * See comment in __sta_info_unlink, returns sta if it
643 * needs to be destroyed.
645 static struct sta_info *__sta_info_unpin(struct sta_info *sta)
647 struct sta_info *ret = NULL;
650 spin_lock_irqsave(&sta->local->sta_lock, flags);
651 WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY &&
652 sta->pin_status != STA_INFO_PIN_STAT_PINNED);
653 if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY)
655 sta->pin_status = STA_INFO_PIN_STAT_NORMAL;
656 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
661 static void sta_info_debugfs_add_work(struct work_struct *work)
663 struct ieee80211_local *local =
664 container_of(work, struct ieee80211_local, sta_debugfs_add);
665 struct sta_info *sta, *tmp;
668 /* We need to keep the RTNL across the whole pinned status. */
673 spin_lock_irqsave(&local->sta_lock, flags);
674 list_for_each_entry(tmp, &local->sta_list, list) {
676 * debugfs.add_has_run will be set by
677 * ieee80211_sta_debugfs_add regardless
678 * of what else it does.
680 if (!tmp->debugfs.add_has_run) {
686 spin_unlock_irqrestore(&local->sta_lock, flags);
691 ieee80211_sta_debugfs_add(sta);
692 rate_control_add_sta_debugfs(sta);
694 sta = __sta_info_unpin(sta);
695 sta_info_destroy(sta);
701 static void __ieee80211_run_pending_flush(struct ieee80211_local *local)
703 struct sta_info *sta;
708 spin_lock_irqsave(&local->sta_lock, flags);
709 while (!list_empty(&local->sta_flush_list)) {
710 sta = list_first_entry(&local->sta_flush_list,
711 struct sta_info, list);
712 list_del(&sta->list);
713 spin_unlock_irqrestore(&local->sta_lock, flags);
714 sta_info_destroy(sta);
715 spin_lock_irqsave(&local->sta_lock, flags);
717 spin_unlock_irqrestore(&local->sta_lock, flags);
720 static void ieee80211_sta_flush_work(struct work_struct *work)
722 struct ieee80211_local *local =
723 container_of(work, struct ieee80211_local, sta_flush_work);
726 __ieee80211_run_pending_flush(local);
730 void sta_info_init(struct ieee80211_local *local)
732 spin_lock_init(&local->sta_lock);
733 INIT_LIST_HEAD(&local->sta_list);
734 INIT_LIST_HEAD(&local->sta_flush_list);
735 INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work);
737 setup_timer(&local->sta_cleanup, sta_info_cleanup,
738 (unsigned long)local);
739 local->sta_cleanup.expires =
740 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
742 #ifdef CONFIG_MAC80211_DEBUGFS
743 INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_work);
747 int sta_info_start(struct ieee80211_local *local)
749 add_timer(&local->sta_cleanup);
753 void sta_info_stop(struct ieee80211_local *local)
755 del_timer(&local->sta_cleanup);
756 cancel_work_sync(&local->sta_flush_work);
757 #ifdef CONFIG_MAC80211_DEBUGFS
759 * Make sure the debugfs adding work isn't pending after this
760 * because we're about to be destroyed. It doesn't matter
761 * whether it ran or not since we're going to flush all STAs
764 cancel_work_sync(&local->sta_debugfs_add);
768 sta_info_flush(local, NULL);
769 __ieee80211_run_pending_flush(local);
774 * sta_info_flush - flush matching STA entries from the STA table
776 * Returns the number of removed STA entries.
778 * @local: local interface data
779 * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
781 int sta_info_flush(struct ieee80211_local *local,
782 struct ieee80211_sub_if_data *sdata)
784 struct sta_info *sta, *tmp;
792 spin_lock_irqsave(&local->sta_lock, flags);
793 list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
794 if (!sdata || sdata == sta->sdata) {
795 __sta_info_unlink(&sta);
797 list_add_tail(&sta->list, &tmp_list);
802 spin_unlock_irqrestore(&local->sta_lock, flags);
804 list_for_each_entry_safe(sta, tmp, &tmp_list, list)
805 sta_info_destroy(sta);
811 * sta_info_flush_delayed - flush matching STA entries from the STA table
813 * This function unlinks all stations for a given interface and queues
814 * them for freeing. Note that the workqueue function scheduled here has
815 * to run before any new keys can be added to the system to avoid set_key()
816 * callback ordering issues.
818 * @sdata: the interface
820 void sta_info_flush_delayed(struct ieee80211_sub_if_data *sdata)
822 struct ieee80211_local *local = sdata->local;
823 struct sta_info *sta, *tmp;
827 spin_lock_irqsave(&local->sta_lock, flags);
828 list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
829 if (sdata == sta->sdata) {
830 __sta_info_unlink(&sta);
832 list_add_tail(&sta->list,
833 &local->sta_flush_list);
839 schedule_work(&local->sta_flush_work);
840 spin_unlock_irqrestore(&local->sta_lock, flags);
843 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
844 unsigned long exp_time)
846 struct ieee80211_local *local = sdata->local;
847 struct sta_info *sta, *tmp;
851 spin_lock_irqsave(&local->sta_lock, flags);
852 list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
853 if (time_after(jiffies, sta->last_rx + exp_time)) {
854 #ifdef CONFIG_MAC80211_IBSS_DEBUG
855 printk(KERN_DEBUG "%s: expiring inactive STA %pM\n",
856 sdata->dev->name, sta->sta.addr);
858 __sta_info_unlink(&sta);
860 list_add(&sta->list, &tmp_list);
862 spin_unlock_irqrestore(&local->sta_lock, flags);
864 list_for_each_entry_safe(sta, tmp, &tmp_list, list)
865 sta_info_destroy(sta);
868 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_hw *hw,
871 struct sta_info *sta = sta_info_get(hw_to_local(hw), addr);
877 EXPORT_SYMBOL(ieee80211_find_sta);