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 static struct sta_info *__sta_info_find(struct ieee80211_local *local,
101 sta = rcu_dereference(local->sta_hash[STA_HASH(addr)]);
103 if (compare_ether_addr(sta->sta.addr, addr) == 0)
105 sta = rcu_dereference(sta->hnext);
110 struct sta_info *sta_info_get(struct ieee80211_local *local, u8 *addr)
112 return __sta_info_find(local, addr);
114 EXPORT_SYMBOL(sta_info_get);
116 struct sta_info *sta_info_get_by_idx(struct ieee80211_local *local, int idx,
117 struct net_device *dev)
119 struct sta_info *sta;
122 list_for_each_entry_rcu(sta, &local->sta_list, list) {
123 if (dev && dev != sta->sdata->dev)
136 * __sta_info_free - internal STA free helper
138 * @local: pointer to the global information
139 * @sta: STA info to free
141 * This function must undo everything done by sta_info_alloc()
142 * that may happen before sta_info_insert().
144 static void __sta_info_free(struct ieee80211_local *local,
145 struct sta_info *sta)
147 DECLARE_MAC_BUF(mbuf);
149 rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
150 rate_control_put(sta->rate_ctrl);
152 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
153 printk(KERN_DEBUG "%s: Destroyed STA %s\n",
154 wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->sta.addr));
155 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
160 void sta_info_destroy(struct sta_info *sta)
162 struct ieee80211_local *local;
173 rate_control_remove_sta_debugfs(sta);
174 ieee80211_sta_debugfs_remove(sta);
176 #ifdef CONFIG_MAC80211_MESH
177 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
178 mesh_plink_deactivate(sta);
182 * We have only unlinked the key, and actually destroying it
183 * may mean it is removed from hardware which requires that
184 * the key->sta pointer is still valid, so flush the key todo
187 * ieee80211_key_todo() will synchronize_rcu() so after this
188 * nothing can reference this sta struct any more.
190 ieee80211_key_todo();
192 #ifdef CONFIG_MAC80211_MESH
193 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
194 del_timer_sync(&sta->plink_timer);
197 while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
198 local->total_ps_buffered--;
199 dev_kfree_skb_any(skb);
202 while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL)
203 dev_kfree_skb_any(skb);
205 for (i = 0; i < STA_TID_NUM; i++) {
206 spin_lock_bh(&sta->lock);
207 if (sta->ampdu_mlme.tid_rx[i])
208 del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer);
209 if (sta->ampdu_mlme.tid_tx[i])
210 del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer);
211 spin_unlock_bh(&sta->lock);
214 __sta_info_free(local, sta);
218 /* Caller must hold local->sta_lock */
219 static void sta_info_hash_add(struct ieee80211_local *local,
220 struct sta_info *sta)
222 sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
223 rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
226 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
229 struct ieee80211_local *local = sdata->local;
230 struct sta_info *sta;
232 DECLARE_MAC_BUF(mbuf);
234 sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
238 spin_lock_init(&sta->lock);
239 spin_lock_init(&sta->flaglock);
241 memcpy(sta->sta.addr, addr, ETH_ALEN);
245 sta->rate_ctrl = rate_control_get(local->rate_ctrl);
246 sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
248 if (!sta->rate_ctrl_priv) {
249 rate_control_put(sta->rate_ctrl);
254 for (i = 0; i < STA_TID_NUM; i++) {
255 /* timer_to_tid must be initialized with identity mapping to
256 * enable session_timer's data differentiation. refer to
257 * sta_rx_agg_session_timer_expired for useage */
258 sta->timer_to_tid[i] = i;
259 /* tid to tx queue: initialize according to HW (0 is valid) */
260 sta->tid_to_tx_q[i] = ieee80211_num_queues(&local->hw);
262 sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE;
263 sta->ampdu_mlme.tid_rx[i] = NULL;
265 sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE;
266 sta->ampdu_mlme.tid_tx[i] = NULL;
267 sta->ampdu_mlme.addba_req_num[i] = 0;
269 skb_queue_head_init(&sta->ps_tx_buf);
270 skb_queue_head_init(&sta->tx_filtered);
272 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
273 printk(KERN_DEBUG "%s: Allocated STA %s\n",
274 wiphy_name(local->hw.wiphy), print_mac(mbuf, sta->sta.addr));
275 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
277 #ifdef CONFIG_MAC80211_MESH
278 sta->plink_state = PLINK_LISTEN;
279 init_timer(&sta->plink_timer);
285 int sta_info_insert(struct sta_info *sta)
287 struct ieee80211_local *local = sta->local;
288 struct ieee80211_sub_if_data *sdata = sta->sdata;
291 DECLARE_MAC_BUF(mac);
294 * Can't be a WARN_ON because it can be triggered through a race:
295 * something inserts a STA (on one CPU) without holding the RTNL
296 * and another CPU turns off the net device.
298 if (unlikely(!netif_running(sdata->dev))) {
303 if (WARN_ON(compare_ether_addr(sta->sta.addr, sdata->dev->dev_addr) == 0 ||
304 is_multicast_ether_addr(sta->sta.addr))) {
309 spin_lock_irqsave(&local->sta_lock, flags);
310 /* check if STA exists already */
311 if (__sta_info_find(local, sta->sta.addr)) {
312 spin_unlock_irqrestore(&local->sta_lock, flags);
316 list_add(&sta->list, &local->sta_list);
318 sta_info_hash_add(local, sta);
321 if (local->ops->sta_notify) {
322 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
323 sdata = container_of(sdata->bss,
324 struct ieee80211_sub_if_data,
327 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
328 STA_NOTIFY_ADD, &sta->sta);
331 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
332 printk(KERN_DEBUG "%s: Inserted STA %s\n",
333 wiphy_name(local->hw.wiphy), print_mac(mac, sta->sta.addr));
334 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
336 spin_unlock_irqrestore(&local->sta_lock, flags);
338 #ifdef CONFIG_MAC80211_DEBUGFS
340 * Debugfs entry adding might sleep, so schedule process
341 * context task for adding entry for STAs that do not yet
343 * NOTE: due to auto-freeing semantics this may only be done
344 * if the insertion is successful!
346 schedule_work(&local->sta_debugfs_add);
349 if (ieee80211_vif_is_mesh(&sdata->vif))
350 mesh_accept_plinks_update(sdata);
355 __sta_info_free(local, sta);
359 static inline void __bss_tim_set(struct ieee80211_if_ap *bss, u16 aid)
362 * This format has been mandated by the IEEE specifications,
363 * so this line may not be changed to use the __set_bit() format.
365 bss->tim[aid / 8] |= (1 << (aid % 8));
368 static inline void __bss_tim_clear(struct ieee80211_if_ap *bss, u16 aid)
371 * This format has been mandated by the IEEE specifications,
372 * so this line may not be changed to use the __clear_bit() format.
374 bss->tim[aid / 8] &= ~(1 << (aid % 8));
377 static void __sta_info_set_tim_bit(struct ieee80211_if_ap *bss,
378 struct sta_info *sta)
382 __bss_tim_set(bss, sta->sta.aid);
384 if (sta->local->ops->set_tim) {
385 sta->local->tim_in_locked_section = true;
386 sta->local->ops->set_tim(local_to_hw(sta->local),
388 sta->local->tim_in_locked_section = false;
392 void sta_info_set_tim_bit(struct sta_info *sta)
396 BUG_ON(!sta->sdata->bss);
398 spin_lock_irqsave(&sta->local->sta_lock, flags);
399 __sta_info_set_tim_bit(sta->sdata->bss, sta);
400 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
403 static void __sta_info_clear_tim_bit(struct ieee80211_if_ap *bss,
404 struct sta_info *sta)
408 __bss_tim_clear(bss, sta->sta.aid);
410 if (sta->local->ops->set_tim) {
411 sta->local->tim_in_locked_section = true;
412 sta->local->ops->set_tim(local_to_hw(sta->local),
414 sta->local->tim_in_locked_section = false;
418 void sta_info_clear_tim_bit(struct sta_info *sta)
422 BUG_ON(!sta->sdata->bss);
424 spin_lock_irqsave(&sta->local->sta_lock, flags);
425 __sta_info_clear_tim_bit(sta->sdata->bss, sta);
426 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
429 static void __sta_info_unlink(struct sta_info **sta)
431 struct ieee80211_local *local = (*sta)->local;
432 struct ieee80211_sub_if_data *sdata = (*sta)->sdata;
433 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
434 DECLARE_MAC_BUF(mbuf);
437 * pull caller's reference if we're already gone.
439 if (sta_info_hash_del(local, *sta)) {
445 ieee80211_key_free((*sta)->key);
446 WARN_ON((*sta)->key);
449 list_del(&(*sta)->list);
451 if (test_and_clear_sta_flags(*sta, WLAN_STA_PS)) {
454 atomic_dec(&sdata->bss->num_sta_ps);
455 __sta_info_clear_tim_bit(sdata->bss, *sta);
460 if (local->ops->sta_notify) {
461 if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
462 sdata = container_of(sdata->bss,
463 struct ieee80211_sub_if_data,
466 local->ops->sta_notify(local_to_hw(local), &sdata->vif,
467 STA_NOTIFY_REMOVE, &(*sta)->sta);
470 if (ieee80211_vif_is_mesh(&sdata->vif)) {
471 mesh_accept_plinks_update(sdata);
472 #ifdef CONFIG_MAC80211_MESH
473 del_timer(&(*sta)->plink_timer);
477 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
478 printk(KERN_DEBUG "%s: Removed STA %s\n",
479 wiphy_name(local->hw.wiphy), print_mac(mbuf, (*sta)->sta.addr));
480 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
483 * Finally, pull caller's reference if the STA is pinned by the
484 * task that is adding the debugfs entries. In that case, we
485 * leave the STA "to be freed".
487 * The rules are not trivial, but not too complex either:
488 * (1) pin_status is only modified under the sta_lock
489 * (2) STAs may only be pinned under the RTNL so that
490 * sta_info_flush() is guaranteed to actually destroy
491 * all STAs that are active for a given interface, this
492 * is required for correctness because otherwise we
493 * could notify a driver that an interface is going
494 * away and only after that (!) notify it about a STA
495 * on that interface going away.
496 * (3) sta_info_debugfs_add_work() will set the status
497 * to PINNED when it found an item that needs a new
498 * debugfs directory created. In that case, that item
499 * must not be freed although all *RCU* users are done
500 * with it. Hence, we tell the caller of _unlink()
501 * that the item is already gone (as can happen when
502 * two tasks try to unlink/destroy at the same time)
503 * (4) We set the pin_status to DESTROY here when we
505 * (5) sta_info_debugfs_add_work() will reset the pin_status
506 * from PINNED to NORMAL when it is done with the item,
507 * but will check for DESTROY before resetting it in
508 * which case it will free the item.
510 if ((*sta)->pin_status == STA_INFO_PIN_STAT_PINNED) {
511 (*sta)->pin_status = STA_INFO_PIN_STAT_DESTROY;
517 void sta_info_unlink(struct sta_info **sta)
519 struct ieee80211_local *local = (*sta)->local;
522 spin_lock_irqsave(&local->sta_lock, flags);
523 __sta_info_unlink(sta);
524 spin_unlock_irqrestore(&local->sta_lock, flags);
527 static inline int sta_info_buffer_expired(struct ieee80211_local *local,
528 struct sta_info *sta,
531 struct ieee80211_tx_info *info;
537 info = IEEE80211_SKB_CB(skb);
539 /* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
540 timeout = (sta->listen_interval * local->hw.conf.beacon_int * 32 /
542 if (timeout < STA_TX_BUFFER_EXPIRE)
543 timeout = STA_TX_BUFFER_EXPIRE;
544 return time_after(jiffies, info->control.jiffies + timeout);
548 static void sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
549 struct sta_info *sta)
553 struct ieee80211_sub_if_data *sdata;
554 DECLARE_MAC_BUF(mac);
556 if (skb_queue_empty(&sta->ps_tx_buf))
560 spin_lock_irqsave(&sta->ps_tx_buf.lock, flags);
561 skb = skb_peek(&sta->ps_tx_buf);
562 if (sta_info_buffer_expired(local, sta, skb))
563 skb = __skb_dequeue(&sta->ps_tx_buf);
566 spin_unlock_irqrestore(&sta->ps_tx_buf.lock, flags);
572 local->total_ps_buffered--;
573 #ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
574 printk(KERN_DEBUG "Buffered frame expired (STA "
575 "%s)\n", print_mac(mac, sta->sta.addr));
579 if (skb_queue_empty(&sta->ps_tx_buf))
580 sta_info_clear_tim_bit(sta);
585 static void sta_info_cleanup(unsigned long data)
587 struct ieee80211_local *local = (struct ieee80211_local *) data;
588 struct sta_info *sta;
591 list_for_each_entry_rcu(sta, &local->sta_list, list)
592 sta_info_cleanup_expire_buffered(local, sta);
595 local->sta_cleanup.expires =
596 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
597 add_timer(&local->sta_cleanup);
600 #ifdef CONFIG_MAC80211_DEBUGFS
602 * See comment in __sta_info_unlink,
603 * caller must hold local->sta_lock.
605 static void __sta_info_pin(struct sta_info *sta)
607 WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_NORMAL);
608 sta->pin_status = STA_INFO_PIN_STAT_PINNED;
612 * See comment in __sta_info_unlink, returns sta if it
613 * needs to be destroyed.
615 static struct sta_info *__sta_info_unpin(struct sta_info *sta)
617 struct sta_info *ret = NULL;
620 spin_lock_irqsave(&sta->local->sta_lock, flags);
621 WARN_ON(sta->pin_status != STA_INFO_PIN_STAT_DESTROY &&
622 sta->pin_status != STA_INFO_PIN_STAT_PINNED);
623 if (sta->pin_status == STA_INFO_PIN_STAT_DESTROY)
625 sta->pin_status = STA_INFO_PIN_STAT_NORMAL;
626 spin_unlock_irqrestore(&sta->local->sta_lock, flags);
631 static void sta_info_debugfs_add_work(struct work_struct *work)
633 struct ieee80211_local *local =
634 container_of(work, struct ieee80211_local, sta_debugfs_add);
635 struct sta_info *sta, *tmp;
638 /* We need to keep the RTNL across the whole pinned status. */
643 spin_lock_irqsave(&local->sta_lock, flags);
644 list_for_each_entry(tmp, &local->sta_list, list) {
645 if (!tmp->debugfs.dir) {
651 spin_unlock_irqrestore(&local->sta_lock, flags);
656 ieee80211_sta_debugfs_add(sta);
657 rate_control_add_sta_debugfs(sta);
659 sta = __sta_info_unpin(sta);
660 sta_info_destroy(sta);
666 static void __ieee80211_run_pending_flush(struct ieee80211_local *local)
668 struct sta_info *sta;
673 spin_lock_irqsave(&local->sta_lock, flags);
674 while (!list_empty(&local->sta_flush_list)) {
675 sta = list_first_entry(&local->sta_flush_list,
676 struct sta_info, list);
677 list_del(&sta->list);
678 spin_unlock_irqrestore(&local->sta_lock, flags);
679 sta_info_destroy(sta);
680 spin_lock_irqsave(&local->sta_lock, flags);
682 spin_unlock_irqrestore(&local->sta_lock, flags);
685 static void ieee80211_sta_flush_work(struct work_struct *work)
687 struct ieee80211_local *local =
688 container_of(work, struct ieee80211_local, sta_flush_work);
691 __ieee80211_run_pending_flush(local);
695 void sta_info_init(struct ieee80211_local *local)
697 spin_lock_init(&local->sta_lock);
698 INIT_LIST_HEAD(&local->sta_list);
699 INIT_LIST_HEAD(&local->sta_flush_list);
700 INIT_WORK(&local->sta_flush_work, ieee80211_sta_flush_work);
702 setup_timer(&local->sta_cleanup, sta_info_cleanup,
703 (unsigned long)local);
704 local->sta_cleanup.expires =
705 round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL);
707 #ifdef CONFIG_MAC80211_DEBUGFS
708 INIT_WORK(&local->sta_debugfs_add, sta_info_debugfs_add_work);
712 int sta_info_start(struct ieee80211_local *local)
714 add_timer(&local->sta_cleanup);
718 void sta_info_stop(struct ieee80211_local *local)
720 del_timer(&local->sta_cleanup);
721 cancel_work_sync(&local->sta_flush_work);
722 #ifdef CONFIG_MAC80211_DEBUGFS
724 * Make sure the debugfs adding work isn't pending after this
725 * because we're about to be destroyed. It doesn't matter
726 * whether it ran or not since we're going to flush all STAs
729 cancel_work_sync(&local->sta_debugfs_add);
733 sta_info_flush(local, NULL);
734 __ieee80211_run_pending_flush(local);
739 * sta_info_flush - flush matching STA entries from the STA table
741 * Returns the number of removed STA entries.
743 * @local: local interface data
744 * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
746 int sta_info_flush(struct ieee80211_local *local,
747 struct ieee80211_sub_if_data *sdata)
749 struct sta_info *sta, *tmp;
757 spin_lock_irqsave(&local->sta_lock, flags);
758 list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
759 if (!sdata || sdata == sta->sdata) {
760 __sta_info_unlink(&sta);
762 list_add_tail(&sta->list, &tmp_list);
767 spin_unlock_irqrestore(&local->sta_lock, flags);
769 list_for_each_entry_safe(sta, tmp, &tmp_list, list)
770 sta_info_destroy(sta);
776 * sta_info_flush_delayed - flush matching STA entries from the STA table
778 * This function unlinks all stations for a given interface and queues
779 * them for freeing. Note that the workqueue function scheduled here has
780 * to run before any new keys can be added to the system to avoid set_key()
781 * callback ordering issues.
783 * @sdata: the interface
785 void sta_info_flush_delayed(struct ieee80211_sub_if_data *sdata)
787 struct ieee80211_local *local = sdata->local;
788 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 == sta->sdata) {
795 __sta_info_unlink(&sta);
797 list_add_tail(&sta->list,
798 &local->sta_flush_list);
804 schedule_work(&local->sta_flush_work);
805 spin_unlock_irqrestore(&local->sta_lock, flags);
808 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
809 unsigned long exp_time)
811 struct ieee80211_local *local = sdata->local;
812 struct sta_info *sta, *tmp;
814 DECLARE_MAC_BUF(mac);
817 spin_lock_irqsave(&local->sta_lock, flags);
818 list_for_each_entry_safe(sta, tmp, &local->sta_list, list)
819 if (time_after(jiffies, sta->last_rx + exp_time)) {
820 #ifdef CONFIG_MAC80211_IBSS_DEBUG
821 printk(KERN_DEBUG "%s: expiring inactive STA %s\n",
822 sdata->dev->name, print_mac(mac, sta->sta.addr));
824 __sta_info_unlink(&sta);
826 list_add(&sta->list, &tmp_list);
828 spin_unlock_irqrestore(&local->sta_lock, flags);
830 list_for_each_entry_safe(sta, tmp, &tmp_list, list)
831 sta_info_destroy(sta);
834 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_hw *hw,
837 struct sta_info *sta = __sta_info_find(hw_to_local(hw), addr);
843 EXPORT_SYMBOL(ieee80211_find_sta);