xref: /linux/net/mac80211/sta_info.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
4  *
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.
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/etherdevice.h>
13 #include <linux/netdevice.h>
14 #include <linux/types.h>
15 #include <linux/slab.h>
16 #include <linux/skbuff.h>
17 #include <linux/if_arp.h>
18 #include <linux/timer.h>
19 #include <linux/rtnetlink.h>
20 
21 #include <net/mac80211.h>
22 #include "ieee80211_i.h"
23 #include "driver-ops.h"
24 #include "rate.h"
25 #include "sta_info.h"
26 #include "debugfs_sta.h"
27 #include "mesh.h"
28 #include "wme.h"
29 
30 /**
31  * DOC: STA information lifetime rules
32  *
33  * STA info structures (&struct sta_info) are managed in a hash table
34  * for faster lookup and a list for iteration. They are managed using
35  * RCU, i.e. access to the list and hash table is protected by RCU.
36  *
37  * Upon allocating a STA info structure with sta_info_alloc(), the caller
38  * owns that structure. It must then insert it into the hash table using
39  * either sta_info_insert() or sta_info_insert_rcu(); only in the latter
40  * case (which acquires an rcu read section but must not be called from
41  * within one) will the pointer still be valid after the call. Note that
42  * the caller may not do much with the STA info before inserting it, in
43  * particular, it may not start any mesh peer link management or add
44  * encryption keys.
45  *
46  * When the insertion fails (sta_info_insert()) returns non-zero), the
47  * structure will have been freed by sta_info_insert()!
48  *
49  * Station entries are added by mac80211 when you establish a link with a
50  * peer. This means different things for the different type of interfaces
51  * we support. For a regular station this mean we add the AP sta when we
52  * receive an association response from the AP. For IBSS this occurs when
53  * get to know about a peer on the same IBSS. For WDS we add the sta for
54  * the peer immediately upon device open. When using AP mode we add stations
55  * for each respective station upon request from userspace through nl80211.
56  *
57  * In order to remove a STA info structure, various sta_info_destroy_*()
58  * calls are available.
59  *
60  * There is no concept of ownership on a STA entry, each structure is
61  * owned by the global hash table/list until it is removed. All users of
62  * the structure need to be RCU protected so that the structure won't be
63  * freed before they are done using it.
64  */
65 
66 /* Caller must hold local->sta_mtx */
67 static int sta_info_hash_del(struct ieee80211_local *local,
68 			     struct sta_info *sta)
69 {
70 	struct sta_info *s;
71 
72 	s = rcu_dereference_protected(local->sta_hash[STA_HASH(sta->sta.addr)],
73 				      lockdep_is_held(&local->sta_mtx));
74 	if (!s)
75 		return -ENOENT;
76 	if (s == sta) {
77 		rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)],
78 				   s->hnext);
79 		return 0;
80 	}
81 
82 	while (rcu_access_pointer(s->hnext) &&
83 	       rcu_access_pointer(s->hnext) != sta)
84 		s = rcu_dereference_protected(s->hnext,
85 					lockdep_is_held(&local->sta_mtx));
86 	if (rcu_access_pointer(s->hnext)) {
87 		rcu_assign_pointer(s->hnext, sta->hnext);
88 		return 0;
89 	}
90 
91 	return -ENOENT;
92 }
93 
94 static void free_sta_work(struct work_struct *wk)
95 {
96 	struct sta_info *sta = container_of(wk, struct sta_info, free_sta_wk);
97 	int ac, i;
98 	struct tid_ampdu_tx *tid_tx;
99 	struct ieee80211_sub_if_data *sdata = sta->sdata;
100 	struct ieee80211_local *local = sdata->local;
101 	struct ps_data *ps;
102 
103 	/*
104 	 * At this point, when being called as call_rcu callback,
105 	 * neither mac80211 nor the driver can reference this
106 	 * sta struct any more except by still existing timers
107 	 * associated with this station that we clean up below.
108 	 */
109 
110 	if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
111 		if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
112 		    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
113 			ps = &sdata->bss->ps;
114 		else
115 			return;
116 
117 		clear_sta_flag(sta, WLAN_STA_PS_STA);
118 
119 		atomic_dec(&ps->num_sta_ps);
120 		sta_info_recalc_tim(sta);
121 	}
122 
123 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
124 		local->total_ps_buffered -= skb_queue_len(&sta->ps_tx_buf[ac]);
125 		ieee80211_purge_tx_queue(&local->hw, &sta->ps_tx_buf[ac]);
126 		ieee80211_purge_tx_queue(&local->hw, &sta->tx_filtered[ac]);
127 	}
128 
129 #ifdef CONFIG_MAC80211_MESH
130 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
131 		mesh_accept_plinks_update(sdata);
132 		mesh_plink_deactivate(sta);
133 		del_timer_sync(&sta->plink_timer);
134 	}
135 #endif
136 
137 	cancel_work_sync(&sta->drv_unblock_wk);
138 
139 	/*
140 	 * Destroy aggregation state here. It would be nice to wait for the
141 	 * driver to finish aggregation stop and then clean up, but for now
142 	 * drivers have to handle aggregation stop being requested, followed
143 	 * directly by station destruction.
144 	 */
145 	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
146 		tid_tx = rcu_dereference_raw(sta->ampdu_mlme.tid_tx[i]);
147 		if (!tid_tx)
148 			continue;
149 		ieee80211_purge_tx_queue(&local->hw, &tid_tx->pending);
150 		kfree(tid_tx);
151 	}
152 
153 	sta_info_free(local, sta);
154 }
155 
156 static void free_sta_rcu(struct rcu_head *h)
157 {
158 	struct sta_info *sta = container_of(h, struct sta_info, rcu_head);
159 
160 	ieee80211_queue_work(&sta->local->hw, &sta->free_sta_wk);
161 }
162 
163 /* protected by RCU */
164 struct sta_info *sta_info_get(struct ieee80211_sub_if_data *sdata,
165 			      const u8 *addr)
166 {
167 	struct ieee80211_local *local = sdata->local;
168 	struct sta_info *sta;
169 
170 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
171 				    lockdep_is_held(&local->sta_mtx));
172 	while (sta) {
173 		if (sta->sdata == sdata &&
174 		    ether_addr_equal(sta->sta.addr, addr))
175 			break;
176 		sta = rcu_dereference_check(sta->hnext,
177 					    lockdep_is_held(&local->sta_mtx));
178 	}
179 	return sta;
180 }
181 
182 /*
183  * Get sta info either from the specified interface
184  * or from one of its vlans
185  */
186 struct sta_info *sta_info_get_bss(struct ieee80211_sub_if_data *sdata,
187 				  const u8 *addr)
188 {
189 	struct ieee80211_local *local = sdata->local;
190 	struct sta_info *sta;
191 
192 	sta = rcu_dereference_check(local->sta_hash[STA_HASH(addr)],
193 				    lockdep_is_held(&local->sta_mtx));
194 	while (sta) {
195 		if ((sta->sdata == sdata ||
196 		     (sta->sdata->bss && sta->sdata->bss == sdata->bss)) &&
197 		    ether_addr_equal(sta->sta.addr, addr))
198 			break;
199 		sta = rcu_dereference_check(sta->hnext,
200 					    lockdep_is_held(&local->sta_mtx));
201 	}
202 	return sta;
203 }
204 
205 struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata,
206 				     int idx)
207 {
208 	struct ieee80211_local *local = sdata->local;
209 	struct sta_info *sta;
210 	int i = 0;
211 
212 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
213 		if (sdata != sta->sdata)
214 			continue;
215 		if (i < idx) {
216 			++i;
217 			continue;
218 		}
219 		return sta;
220 	}
221 
222 	return NULL;
223 }
224 
225 /**
226  * sta_info_free - free STA
227  *
228  * @local: pointer to the global information
229  * @sta: STA info to free
230  *
231  * This function must undo everything done by sta_info_alloc()
232  * that may happen before sta_info_insert(). It may only be
233  * called when sta_info_insert() has not been attempted (and
234  * if that fails, the station is freed anyway.)
235  */
236 void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
237 {
238 	if (sta->rate_ctrl)
239 		rate_control_free_sta(sta);
240 
241 	sta_dbg(sta->sdata, "Destroyed STA %pM\n", sta->sta.addr);
242 
243 	kfree(sta);
244 }
245 
246 /* Caller must hold local->sta_mtx */
247 static void sta_info_hash_add(struct ieee80211_local *local,
248 			      struct sta_info *sta)
249 {
250 	lockdep_assert_held(&local->sta_mtx);
251 	sta->hnext = local->sta_hash[STA_HASH(sta->sta.addr)];
252 	rcu_assign_pointer(local->sta_hash[STA_HASH(sta->sta.addr)], sta);
253 }
254 
255 static void sta_unblock(struct work_struct *wk)
256 {
257 	struct sta_info *sta;
258 
259 	sta = container_of(wk, struct sta_info, drv_unblock_wk);
260 
261 	if (sta->dead)
262 		return;
263 
264 	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
265 		local_bh_disable();
266 		ieee80211_sta_ps_deliver_wakeup(sta);
267 		local_bh_enable();
268 	} else if (test_and_clear_sta_flag(sta, WLAN_STA_PSPOLL)) {
269 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
270 
271 		local_bh_disable();
272 		ieee80211_sta_ps_deliver_poll_response(sta);
273 		local_bh_enable();
274 	} else if (test_and_clear_sta_flag(sta, WLAN_STA_UAPSD)) {
275 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
276 
277 		local_bh_disable();
278 		ieee80211_sta_ps_deliver_uapsd(sta);
279 		local_bh_enable();
280 	} else
281 		clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
282 }
283 
284 static int sta_prepare_rate_control(struct ieee80211_local *local,
285 				    struct sta_info *sta, gfp_t gfp)
286 {
287 	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
288 		return 0;
289 
290 	sta->rate_ctrl = local->rate_ctrl;
291 	sta->rate_ctrl_priv = rate_control_alloc_sta(sta->rate_ctrl,
292 						     &sta->sta, gfp);
293 	if (!sta->rate_ctrl_priv)
294 		return -ENOMEM;
295 
296 	return 0;
297 }
298 
299 struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
300 				const u8 *addr, gfp_t gfp)
301 {
302 	struct ieee80211_local *local = sdata->local;
303 	struct sta_info *sta;
304 	struct timespec uptime;
305 	int i;
306 
307 	sta = kzalloc(sizeof(*sta) + local->hw.sta_data_size, gfp);
308 	if (!sta)
309 		return NULL;
310 
311 	spin_lock_init(&sta->lock);
312 	INIT_WORK(&sta->drv_unblock_wk, sta_unblock);
313 	INIT_WORK(&sta->free_sta_wk, free_sta_work);
314 	INIT_WORK(&sta->ampdu_mlme.work, ieee80211_ba_session_work);
315 	mutex_init(&sta->ampdu_mlme.mtx);
316 
317 	memcpy(sta->sta.addr, addr, ETH_ALEN);
318 	sta->local = local;
319 	sta->sdata = sdata;
320 	sta->last_rx = jiffies;
321 
322 	sta->sta_state = IEEE80211_STA_NONE;
323 
324 	do_posix_clock_monotonic_gettime(&uptime);
325 	sta->last_connected = uptime.tv_sec;
326 	ewma_init(&sta->avg_signal, 1024, 8);
327 
328 	if (sta_prepare_rate_control(local, sta, gfp)) {
329 		kfree(sta);
330 		return NULL;
331 	}
332 
333 	for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
334 		/*
335 		 * timer_to_tid must be initialized with identity mapping
336 		 * to enable session_timer's data differentiation. See
337 		 * sta_rx_agg_session_timer_expired for usage.
338 		 */
339 		sta->timer_to_tid[i] = i;
340 	}
341 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
342 		skb_queue_head_init(&sta->ps_tx_buf[i]);
343 		skb_queue_head_init(&sta->tx_filtered[i]);
344 	}
345 
346 	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
347 		sta->last_seq_ctrl[i] = cpu_to_le16(USHRT_MAX);
348 
349 	sta_dbg(sdata, "Allocated STA %pM\n", sta->sta.addr);
350 
351 #ifdef CONFIG_MAC80211_MESH
352 	sta->plink_state = NL80211_PLINK_LISTEN;
353 	init_timer(&sta->plink_timer);
354 #endif
355 
356 	return sta;
357 }
358 
359 static int sta_info_insert_check(struct sta_info *sta)
360 {
361 	struct ieee80211_sub_if_data *sdata = sta->sdata;
362 
363 	/*
364 	 * Can't be a WARN_ON because it can be triggered through a race:
365 	 * something inserts a STA (on one CPU) without holding the RTNL
366 	 * and another CPU turns off the net device.
367 	 */
368 	if (unlikely(!ieee80211_sdata_running(sdata)))
369 		return -ENETDOWN;
370 
371 	if (WARN_ON(ether_addr_equal(sta->sta.addr, sdata->vif.addr) ||
372 		    is_multicast_ether_addr(sta->sta.addr)))
373 		return -EINVAL;
374 
375 	return 0;
376 }
377 
378 static int sta_info_insert_drv_state(struct ieee80211_local *local,
379 				     struct ieee80211_sub_if_data *sdata,
380 				     struct sta_info *sta)
381 {
382 	enum ieee80211_sta_state state;
383 	int err = 0;
384 
385 	for (state = IEEE80211_STA_NOTEXIST; state < sta->sta_state; state++) {
386 		err = drv_sta_state(local, sdata, sta, state, state + 1);
387 		if (err)
388 			break;
389 	}
390 
391 	if (!err) {
392 		/*
393 		 * Drivers using legacy sta_add/sta_remove callbacks only
394 		 * get uploaded set to true after sta_add is called.
395 		 */
396 		if (!local->ops->sta_add)
397 			sta->uploaded = true;
398 		return 0;
399 	}
400 
401 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
402 		sdata_info(sdata,
403 			   "failed to move IBSS STA %pM to state %d (%d) - keeping it anyway\n",
404 			   sta->sta.addr, state + 1, err);
405 		err = 0;
406 	}
407 
408 	/* unwind on error */
409 	for (; state > IEEE80211_STA_NOTEXIST; state--)
410 		WARN_ON(drv_sta_state(local, sdata, sta, state, state - 1));
411 
412 	return err;
413 }
414 
415 /*
416  * should be called with sta_mtx locked
417  * this function replaces the mutex lock
418  * with a RCU lock
419  */
420 static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
421 {
422 	struct ieee80211_local *local = sta->local;
423 	struct ieee80211_sub_if_data *sdata = sta->sdata;
424 	struct station_info sinfo;
425 	int err = 0;
426 
427 	lockdep_assert_held(&local->sta_mtx);
428 
429 	/* check if STA exists already */
430 	if (sta_info_get_bss(sdata, sta->sta.addr)) {
431 		err = -EEXIST;
432 		goto out_err;
433 	}
434 
435 	/* notify driver */
436 	err = sta_info_insert_drv_state(local, sdata, sta);
437 	if (err)
438 		goto out_err;
439 
440 	local->num_sta++;
441 	local->sta_generation++;
442 	smp_mb();
443 
444 	/* make the station visible */
445 	sta_info_hash_add(local, sta);
446 
447 	list_add_rcu(&sta->list, &local->sta_list);
448 
449 	set_sta_flag(sta, WLAN_STA_INSERTED);
450 
451 	ieee80211_sta_debugfs_add(sta);
452 	rate_control_add_sta_debugfs(sta);
453 
454 	memset(&sinfo, 0, sizeof(sinfo));
455 	sinfo.filled = 0;
456 	sinfo.generation = local->sta_generation;
457 	cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);
458 
459 	sta_dbg(sdata, "Inserted STA %pM\n", sta->sta.addr);
460 
461 	/* move reference to rcu-protected */
462 	rcu_read_lock();
463 	mutex_unlock(&local->sta_mtx);
464 
465 	if (ieee80211_vif_is_mesh(&sdata->vif))
466 		mesh_accept_plinks_update(sdata);
467 
468 	return 0;
469  out_err:
470 	mutex_unlock(&local->sta_mtx);
471 	rcu_read_lock();
472 	return err;
473 }
474 
475 int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU)
476 {
477 	struct ieee80211_local *local = sta->local;
478 	int err = 0;
479 
480 	might_sleep();
481 
482 	err = sta_info_insert_check(sta);
483 	if (err) {
484 		rcu_read_lock();
485 		goto out_free;
486 	}
487 
488 	mutex_lock(&local->sta_mtx);
489 
490 	err = sta_info_insert_finish(sta);
491 	if (err)
492 		goto out_free;
493 
494 	return 0;
495  out_free:
496 	BUG_ON(!err);
497 	sta_info_free(local, sta);
498 	return err;
499 }
500 
501 int sta_info_insert(struct sta_info *sta)
502 {
503 	int err = sta_info_insert_rcu(sta);
504 
505 	rcu_read_unlock();
506 
507 	return err;
508 }
509 
510 static inline void __bss_tim_set(u8 *tim, u16 id)
511 {
512 	/*
513 	 * This format has been mandated by the IEEE specifications,
514 	 * so this line may not be changed to use the __set_bit() format.
515 	 */
516 	tim[id / 8] |= (1 << (id % 8));
517 }
518 
519 static inline void __bss_tim_clear(u8 *tim, u16 id)
520 {
521 	/*
522 	 * This format has been mandated by the IEEE specifications,
523 	 * so this line may not be changed to use the __clear_bit() format.
524 	 */
525 	tim[id / 8] &= ~(1 << (id % 8));
526 }
527 
528 static unsigned long ieee80211_tids_for_ac(int ac)
529 {
530 	/* If we ever support TIDs > 7, this obviously needs to be adjusted */
531 	switch (ac) {
532 	case IEEE80211_AC_VO:
533 		return BIT(6) | BIT(7);
534 	case IEEE80211_AC_VI:
535 		return BIT(4) | BIT(5);
536 	case IEEE80211_AC_BE:
537 		return BIT(0) | BIT(3);
538 	case IEEE80211_AC_BK:
539 		return BIT(1) | BIT(2);
540 	default:
541 		WARN_ON(1);
542 		return 0;
543 	}
544 }
545 
546 void sta_info_recalc_tim(struct sta_info *sta)
547 {
548 	struct ieee80211_local *local = sta->local;
549 	struct ps_data *ps;
550 	unsigned long flags;
551 	bool indicate_tim = false;
552 	u8 ignore_for_tim = sta->sta.uapsd_queues;
553 	int ac;
554 	u16 id;
555 
556 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
557 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
558 		if (WARN_ON_ONCE(!sta->sdata->bss))
559 			return;
560 
561 		ps = &sta->sdata->bss->ps;
562 		id = sta->sta.aid;
563 	} else {
564 		return;
565 	}
566 
567 	/* No need to do anything if the driver does all */
568 	if (local->hw.flags & IEEE80211_HW_AP_LINK_PS)
569 		return;
570 
571 	if (sta->dead)
572 		goto done;
573 
574 	/*
575 	 * If all ACs are delivery-enabled then we should build
576 	 * the TIM bit for all ACs anyway; if only some are then
577 	 * we ignore those and build the TIM bit using only the
578 	 * non-enabled ones.
579 	 */
580 	if (ignore_for_tim == BIT(IEEE80211_NUM_ACS) - 1)
581 		ignore_for_tim = 0;
582 
583 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
584 		unsigned long tids;
585 
586 		if (ignore_for_tim & BIT(ac))
587 			continue;
588 
589 		indicate_tim |= !skb_queue_empty(&sta->tx_filtered[ac]) ||
590 				!skb_queue_empty(&sta->ps_tx_buf[ac]);
591 		if (indicate_tim)
592 			break;
593 
594 		tids = ieee80211_tids_for_ac(ac);
595 
596 		indicate_tim |=
597 			sta->driver_buffered_tids & tids;
598 	}
599 
600  done:
601 	spin_lock_irqsave(&local->tim_lock, flags);
602 
603 	if (indicate_tim)
604 		__bss_tim_set(ps->tim, id);
605 	else
606 		__bss_tim_clear(ps->tim, id);
607 
608 	if (local->ops->set_tim) {
609 		local->tim_in_locked_section = true;
610 		drv_set_tim(local, &sta->sta, indicate_tim);
611 		local->tim_in_locked_section = false;
612 	}
613 
614 	spin_unlock_irqrestore(&local->tim_lock, flags);
615 }
616 
617 static bool sta_info_buffer_expired(struct sta_info *sta, struct sk_buff *skb)
618 {
619 	struct ieee80211_tx_info *info;
620 	int timeout;
621 
622 	if (!skb)
623 		return false;
624 
625 	info = IEEE80211_SKB_CB(skb);
626 
627 	/* Timeout: (2 * listen_interval * beacon_int * 1024 / 1000000) sec */
628 	timeout = (sta->listen_interval *
629 		   sta->sdata->vif.bss_conf.beacon_int *
630 		   32 / 15625) * HZ;
631 	if (timeout < STA_TX_BUFFER_EXPIRE)
632 		timeout = STA_TX_BUFFER_EXPIRE;
633 	return time_after(jiffies, info->control.jiffies + timeout);
634 }
635 
636 
637 static bool sta_info_cleanup_expire_buffered_ac(struct ieee80211_local *local,
638 						struct sta_info *sta, int ac)
639 {
640 	unsigned long flags;
641 	struct sk_buff *skb;
642 
643 	/*
644 	 * First check for frames that should expire on the filtered
645 	 * queue. Frames here were rejected by the driver and are on
646 	 * a separate queue to avoid reordering with normal PS-buffered
647 	 * frames. They also aren't accounted for right now in the
648 	 * total_ps_buffered counter.
649 	 */
650 	for (;;) {
651 		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
652 		skb = skb_peek(&sta->tx_filtered[ac]);
653 		if (sta_info_buffer_expired(sta, skb))
654 			skb = __skb_dequeue(&sta->tx_filtered[ac]);
655 		else
656 			skb = NULL;
657 		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
658 
659 		/*
660 		 * Frames are queued in order, so if this one
661 		 * hasn't expired yet we can stop testing. If
662 		 * we actually reached the end of the queue we
663 		 * also need to stop, of course.
664 		 */
665 		if (!skb)
666 			break;
667 		ieee80211_free_txskb(&local->hw, skb);
668 	}
669 
670 	/*
671 	 * Now also check the normal PS-buffered queue, this will
672 	 * only find something if the filtered queue was emptied
673 	 * since the filtered frames are all before the normal PS
674 	 * buffered frames.
675 	 */
676 	for (;;) {
677 		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
678 		skb = skb_peek(&sta->ps_tx_buf[ac]);
679 		if (sta_info_buffer_expired(sta, skb))
680 			skb = __skb_dequeue(&sta->ps_tx_buf[ac]);
681 		else
682 			skb = NULL;
683 		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
684 
685 		/*
686 		 * frames are queued in order, so if this one
687 		 * hasn't expired yet (or we reached the end of
688 		 * the queue) we can stop testing
689 		 */
690 		if (!skb)
691 			break;
692 
693 		local->total_ps_buffered--;
694 		ps_dbg(sta->sdata, "Buffered frame expired (STA %pM)\n",
695 		       sta->sta.addr);
696 		ieee80211_free_txskb(&local->hw, skb);
697 	}
698 
699 	/*
700 	 * Finally, recalculate the TIM bit for this station -- it might
701 	 * now be clear because the station was too slow to retrieve its
702 	 * frames.
703 	 */
704 	sta_info_recalc_tim(sta);
705 
706 	/*
707 	 * Return whether there are any frames still buffered, this is
708 	 * used to check whether the cleanup timer still needs to run,
709 	 * if there are no frames we don't need to rearm the timer.
710 	 */
711 	return !(skb_queue_empty(&sta->ps_tx_buf[ac]) &&
712 		 skb_queue_empty(&sta->tx_filtered[ac]));
713 }
714 
715 static bool sta_info_cleanup_expire_buffered(struct ieee80211_local *local,
716 					     struct sta_info *sta)
717 {
718 	bool have_buffered = false;
719 	int ac;
720 
721 	/* This is only necessary for stations on BSS interfaces */
722 	if (!sta->sdata->bss)
723 		return false;
724 
725 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
726 		have_buffered |=
727 			sta_info_cleanup_expire_buffered_ac(local, sta, ac);
728 
729 	return have_buffered;
730 }
731 
732 int __must_check __sta_info_destroy(struct sta_info *sta)
733 {
734 	struct ieee80211_local *local;
735 	struct ieee80211_sub_if_data *sdata;
736 	int ret, i;
737 
738 	might_sleep();
739 
740 	if (!sta)
741 		return -ENOENT;
742 
743 	local = sta->local;
744 	sdata = sta->sdata;
745 
746 	lockdep_assert_held(&local->sta_mtx);
747 
748 	/*
749 	 * Before removing the station from the driver and
750 	 * rate control, it might still start new aggregation
751 	 * sessions -- block that to make sure the tear-down
752 	 * will be sufficient.
753 	 */
754 	set_sta_flag(sta, WLAN_STA_BLOCK_BA);
755 	ieee80211_sta_tear_down_BA_sessions(sta, false);
756 
757 	ret = sta_info_hash_del(local, sta);
758 	if (ret)
759 		return ret;
760 
761 	list_del_rcu(&sta->list);
762 
763 	mutex_lock(&local->key_mtx);
764 	for (i = 0; i < NUM_DEFAULT_KEYS; i++)
765 		__ieee80211_key_free(key_mtx_dereference(local, sta->gtk[i]));
766 	if (sta->ptk)
767 		__ieee80211_key_free(key_mtx_dereference(local, sta->ptk));
768 	mutex_unlock(&local->key_mtx);
769 
770 	sta->dead = true;
771 
772 	local->num_sta--;
773 	local->sta_generation++;
774 
775 	if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
776 		RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
777 
778 	while (sta->sta_state > IEEE80211_STA_NONE) {
779 		ret = sta_info_move_state(sta, sta->sta_state - 1);
780 		if (ret) {
781 			WARN_ON_ONCE(1);
782 			break;
783 		}
784 	}
785 
786 	if (sta->uploaded) {
787 		ret = drv_sta_state(local, sdata, sta, IEEE80211_STA_NONE,
788 				    IEEE80211_STA_NOTEXIST);
789 		WARN_ON_ONCE(ret != 0);
790 	}
791 
792 	sta_dbg(sdata, "Removed STA %pM\n", sta->sta.addr);
793 
794 	cfg80211_del_sta(sdata->dev, sta->sta.addr, GFP_KERNEL);
795 
796 	rate_control_remove_sta_debugfs(sta);
797 	ieee80211_sta_debugfs_remove(sta);
798 
799 	call_rcu(&sta->rcu_head, free_sta_rcu);
800 
801 	return 0;
802 }
803 
804 int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata, const u8 *addr)
805 {
806 	struct sta_info *sta;
807 	int ret;
808 
809 	mutex_lock(&sdata->local->sta_mtx);
810 	sta = sta_info_get(sdata, addr);
811 	ret = __sta_info_destroy(sta);
812 	mutex_unlock(&sdata->local->sta_mtx);
813 
814 	return ret;
815 }
816 
817 int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
818 			      const u8 *addr)
819 {
820 	struct sta_info *sta;
821 	int ret;
822 
823 	mutex_lock(&sdata->local->sta_mtx);
824 	sta = sta_info_get_bss(sdata, addr);
825 	ret = __sta_info_destroy(sta);
826 	mutex_unlock(&sdata->local->sta_mtx);
827 
828 	return ret;
829 }
830 
831 static void sta_info_cleanup(unsigned long data)
832 {
833 	struct ieee80211_local *local = (struct ieee80211_local *) data;
834 	struct sta_info *sta;
835 	bool timer_needed = false;
836 
837 	rcu_read_lock();
838 	list_for_each_entry_rcu(sta, &local->sta_list, list)
839 		if (sta_info_cleanup_expire_buffered(local, sta))
840 			timer_needed = true;
841 	rcu_read_unlock();
842 
843 	if (local->quiescing)
844 		return;
845 
846 	if (!timer_needed)
847 		return;
848 
849 	mod_timer(&local->sta_cleanup,
850 		  round_jiffies(jiffies + STA_INFO_CLEANUP_INTERVAL));
851 }
852 
853 void sta_info_init(struct ieee80211_local *local)
854 {
855 	spin_lock_init(&local->tim_lock);
856 	mutex_init(&local->sta_mtx);
857 	INIT_LIST_HEAD(&local->sta_list);
858 
859 	setup_timer(&local->sta_cleanup, sta_info_cleanup,
860 		    (unsigned long)local);
861 }
862 
863 void sta_info_stop(struct ieee80211_local *local)
864 {
865 	del_timer(&local->sta_cleanup);
866 	sta_info_flush(local, NULL);
867 }
868 
869 /**
870  * sta_info_flush - flush matching STA entries from the STA table
871  *
872  * Returns the number of removed STA entries.
873  *
874  * @local: local interface data
875  * @sdata: matching rule for the net device (sta->dev) or %NULL to match all STAs
876  */
877 int sta_info_flush(struct ieee80211_local *local,
878 		   struct ieee80211_sub_if_data *sdata)
879 {
880 	struct sta_info *sta, *tmp;
881 	int ret = 0;
882 
883 	might_sleep();
884 
885 	mutex_lock(&local->sta_mtx);
886 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
887 		if (!sdata || sdata == sta->sdata) {
888 			WARN_ON(__sta_info_destroy(sta));
889 			ret++;
890 		}
891 	}
892 	mutex_unlock(&local->sta_mtx);
893 
894 	return ret;
895 }
896 
897 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
898 			  unsigned long exp_time)
899 {
900 	struct ieee80211_local *local = sdata->local;
901 	struct sta_info *sta, *tmp;
902 
903 	mutex_lock(&local->sta_mtx);
904 
905 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
906 		if (sdata != sta->sdata)
907 			continue;
908 
909 		if (time_after(jiffies, sta->last_rx + exp_time)) {
910 			sta_dbg(sta->sdata, "expiring inactive STA %pM\n",
911 				sta->sta.addr);
912 			WARN_ON(__sta_info_destroy(sta));
913 		}
914 	}
915 
916 	mutex_unlock(&local->sta_mtx);
917 }
918 
919 struct ieee80211_sta *ieee80211_find_sta_by_ifaddr(struct ieee80211_hw *hw,
920 					       const u8 *addr,
921 					       const u8 *localaddr)
922 {
923 	struct sta_info *sta, *nxt;
924 
925 	/*
926 	 * Just return a random station if localaddr is NULL
927 	 * ... first in list.
928 	 */
929 	for_each_sta_info(hw_to_local(hw), addr, sta, nxt) {
930 		if (localaddr &&
931 		    !ether_addr_equal(sta->sdata->vif.addr, localaddr))
932 			continue;
933 		if (!sta->uploaded)
934 			return NULL;
935 		return &sta->sta;
936 	}
937 
938 	return NULL;
939 }
940 EXPORT_SYMBOL_GPL(ieee80211_find_sta_by_ifaddr);
941 
942 struct ieee80211_sta *ieee80211_find_sta(struct ieee80211_vif *vif,
943 					 const u8 *addr)
944 {
945 	struct sta_info *sta;
946 
947 	if (!vif)
948 		return NULL;
949 
950 	sta = sta_info_get_bss(vif_to_sdata(vif), addr);
951 	if (!sta)
952 		return NULL;
953 
954 	if (!sta->uploaded)
955 		return NULL;
956 
957 	return &sta->sta;
958 }
959 EXPORT_SYMBOL(ieee80211_find_sta);
960 
961 static void clear_sta_ps_flags(void *_sta)
962 {
963 	struct sta_info *sta = _sta;
964 	struct ieee80211_sub_if_data *sdata = sta->sdata;
965 	struct ps_data *ps;
966 
967 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
968 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
969 		ps = &sdata->bss->ps;
970 	else
971 		return;
972 
973 	clear_sta_flag(sta, WLAN_STA_PS_DRIVER);
974 	if (test_and_clear_sta_flag(sta, WLAN_STA_PS_STA))
975 		atomic_dec(&ps->num_sta_ps);
976 }
977 
978 /* powersave support code */
979 void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
980 {
981 	struct ieee80211_sub_if_data *sdata = sta->sdata;
982 	struct ieee80211_local *local = sdata->local;
983 	struct sk_buff_head pending;
984 	int filtered = 0, buffered = 0, ac;
985 	unsigned long flags;
986 
987 	clear_sta_flag(sta, WLAN_STA_SP);
988 
989 	BUILD_BUG_ON(BITS_TO_LONGS(IEEE80211_NUM_TIDS) > 1);
990 	sta->driver_buffered_tids = 0;
991 
992 	if (!(local->hw.flags & IEEE80211_HW_AP_LINK_PS))
993 		drv_sta_notify(local, sdata, STA_NOTIFY_AWAKE, &sta->sta);
994 
995 	skb_queue_head_init(&pending);
996 
997 	/* Send all buffered frames to the station */
998 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
999 		int count = skb_queue_len(&pending), tmp;
1000 
1001 		spin_lock_irqsave(&sta->tx_filtered[ac].lock, flags);
1002 		skb_queue_splice_tail_init(&sta->tx_filtered[ac], &pending);
1003 		spin_unlock_irqrestore(&sta->tx_filtered[ac].lock, flags);
1004 		tmp = skb_queue_len(&pending);
1005 		filtered += tmp - count;
1006 		count = tmp;
1007 
1008 		spin_lock_irqsave(&sta->ps_tx_buf[ac].lock, flags);
1009 		skb_queue_splice_tail_init(&sta->ps_tx_buf[ac], &pending);
1010 		spin_unlock_irqrestore(&sta->ps_tx_buf[ac].lock, flags);
1011 		tmp = skb_queue_len(&pending);
1012 		buffered += tmp - count;
1013 	}
1014 
1015 	ieee80211_add_pending_skbs_fn(local, &pending, clear_sta_ps_flags, sta);
1016 
1017 	local->total_ps_buffered -= buffered;
1018 
1019 	sta_info_recalc_tim(sta);
1020 
1021 	ps_dbg(sdata,
1022 	       "STA %pM aid %d sending %d filtered/%d PS frames since STA not sleeping anymore\n",
1023 	       sta->sta.addr, sta->sta.aid, filtered, buffered);
1024 }
1025 
1026 static void ieee80211_send_null_response(struct ieee80211_sub_if_data *sdata,
1027 					 struct sta_info *sta, int tid,
1028 					 enum ieee80211_frame_release_type reason)
1029 {
1030 	struct ieee80211_local *local = sdata->local;
1031 	struct ieee80211_qos_hdr *nullfunc;
1032 	struct sk_buff *skb;
1033 	int size = sizeof(*nullfunc);
1034 	__le16 fc;
1035 	bool qos = test_sta_flag(sta, WLAN_STA_WME);
1036 	struct ieee80211_tx_info *info;
1037 	struct ieee80211_chanctx_conf *chanctx_conf;
1038 
1039 	if (qos) {
1040 		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
1041 				 IEEE80211_STYPE_QOS_NULLFUNC |
1042 				 IEEE80211_FCTL_FROMDS);
1043 	} else {
1044 		size -= 2;
1045 		fc = cpu_to_le16(IEEE80211_FTYPE_DATA |
1046 				 IEEE80211_STYPE_NULLFUNC |
1047 				 IEEE80211_FCTL_FROMDS);
1048 	}
1049 
1050 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size);
1051 	if (!skb)
1052 		return;
1053 
1054 	skb_reserve(skb, local->hw.extra_tx_headroom);
1055 
1056 	nullfunc = (void *) skb_put(skb, size);
1057 	nullfunc->frame_control = fc;
1058 	nullfunc->duration_id = 0;
1059 	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
1060 	memcpy(nullfunc->addr2, sdata->vif.addr, ETH_ALEN);
1061 	memcpy(nullfunc->addr3, sdata->vif.addr, ETH_ALEN);
1062 
1063 	skb->priority = tid;
1064 	skb_set_queue_mapping(skb, ieee802_1d_to_ac[tid]);
1065 	if (qos) {
1066 		nullfunc->qos_ctrl = cpu_to_le16(tid);
1067 
1068 		if (reason == IEEE80211_FRAME_RELEASE_UAPSD)
1069 			nullfunc->qos_ctrl |=
1070 				cpu_to_le16(IEEE80211_QOS_CTL_EOSP);
1071 	}
1072 
1073 	info = IEEE80211_SKB_CB(skb);
1074 
1075 	/*
1076 	 * Tell TX path to send this frame even though the
1077 	 * STA may still remain is PS mode after this frame
1078 	 * exchange. Also set EOSP to indicate this packet
1079 	 * ends the poll/service period.
1080 	 */
1081 	info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
1082 		       IEEE80211_TX_STATUS_EOSP |
1083 		       IEEE80211_TX_CTL_REQ_TX_STATUS;
1084 
1085 	drv_allow_buffered_frames(local, sta, BIT(tid), 1, reason, false);
1086 
1087 	rcu_read_lock();
1088 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1089 	if (WARN_ON(!chanctx_conf)) {
1090 		rcu_read_unlock();
1091 		kfree_skb(skb);
1092 		return;
1093 	}
1094 
1095 	ieee80211_xmit(sdata, skb, chanctx_conf->def.chan->band);
1096 	rcu_read_unlock();
1097 }
1098 
1099 static void
1100 ieee80211_sta_ps_deliver_response(struct sta_info *sta,
1101 				  int n_frames, u8 ignored_acs,
1102 				  enum ieee80211_frame_release_type reason)
1103 {
1104 	struct ieee80211_sub_if_data *sdata = sta->sdata;
1105 	struct ieee80211_local *local = sdata->local;
1106 	bool found = false;
1107 	bool more_data = false;
1108 	int ac;
1109 	unsigned long driver_release_tids = 0;
1110 	struct sk_buff_head frames;
1111 
1112 	/* Service or PS-Poll period starts */
1113 	set_sta_flag(sta, WLAN_STA_SP);
1114 
1115 	__skb_queue_head_init(&frames);
1116 
1117 	/*
1118 	 * Get response frame(s) and more data bit for it.
1119 	 */
1120 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
1121 		unsigned long tids;
1122 
1123 		if (ignored_acs & BIT(ac))
1124 			continue;
1125 
1126 		tids = ieee80211_tids_for_ac(ac);
1127 
1128 		if (!found) {
1129 			driver_release_tids = sta->driver_buffered_tids & tids;
1130 			if (driver_release_tids) {
1131 				found = true;
1132 			} else {
1133 				struct sk_buff *skb;
1134 
1135 				while (n_frames > 0) {
1136 					skb = skb_dequeue(&sta->tx_filtered[ac]);
1137 					if (!skb) {
1138 						skb = skb_dequeue(
1139 							&sta->ps_tx_buf[ac]);
1140 						if (skb)
1141 							local->total_ps_buffered--;
1142 					}
1143 					if (!skb)
1144 						break;
1145 					n_frames--;
1146 					found = true;
1147 					__skb_queue_tail(&frames, skb);
1148 				}
1149 			}
1150 
1151 			/*
1152 			 * If the driver has data on more than one TID then
1153 			 * certainly there's more data if we release just a
1154 			 * single frame now (from a single TID).
1155 			 */
1156 			if (reason == IEEE80211_FRAME_RELEASE_PSPOLL &&
1157 			    hweight16(driver_release_tids) > 1) {
1158 				more_data = true;
1159 				driver_release_tids =
1160 					BIT(ffs(driver_release_tids) - 1);
1161 				break;
1162 			}
1163 		}
1164 
1165 		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
1166 		    !skb_queue_empty(&sta->ps_tx_buf[ac])) {
1167 			more_data = true;
1168 			break;
1169 		}
1170 	}
1171 
1172 	if (!found) {
1173 		int tid;
1174 
1175 		/*
1176 		 * For PS-Poll, this can only happen due to a race condition
1177 		 * when we set the TIM bit and the station notices it, but
1178 		 * before it can poll for the frame we expire it.
1179 		 *
1180 		 * For uAPSD, this is said in the standard (11.2.1.5 h):
1181 		 *	At each unscheduled SP for a non-AP STA, the AP shall
1182 		 *	attempt to transmit at least one MSDU or MMPDU, but no
1183 		 *	more than the value specified in the Max SP Length field
1184 		 *	in the QoS Capability element from delivery-enabled ACs,
1185 		 *	that are destined for the non-AP STA.
1186 		 *
1187 		 * Since we have no other MSDU/MMPDU, transmit a QoS null frame.
1188 		 */
1189 
1190 		/* This will evaluate to 1, 3, 5 or 7. */
1191 		tid = 7 - ((ffs(~ignored_acs) - 1) << 1);
1192 
1193 		ieee80211_send_null_response(sdata, sta, tid, reason);
1194 		return;
1195 	}
1196 
1197 	if (!driver_release_tids) {
1198 		struct sk_buff_head pending;
1199 		struct sk_buff *skb;
1200 		int num = 0;
1201 		u16 tids = 0;
1202 
1203 		skb_queue_head_init(&pending);
1204 
1205 		while ((skb = __skb_dequeue(&frames))) {
1206 			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1207 			struct ieee80211_hdr *hdr = (void *) skb->data;
1208 			u8 *qoshdr = NULL;
1209 
1210 			num++;
1211 
1212 			/*
1213 			 * Tell TX path to send this frame even though the
1214 			 * STA may still remain is PS mode after this frame
1215 			 * exchange.
1216 			 */
1217 			info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
1218 
1219 			/*
1220 			 * Use MoreData flag to indicate whether there are
1221 			 * more buffered frames for this STA
1222 			 */
1223 			if (more_data || !skb_queue_empty(&frames))
1224 				hdr->frame_control |=
1225 					cpu_to_le16(IEEE80211_FCTL_MOREDATA);
1226 			else
1227 				hdr->frame_control &=
1228 					cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1229 
1230 			if (ieee80211_is_data_qos(hdr->frame_control) ||
1231 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
1232 				qoshdr = ieee80211_get_qos_ctl(hdr);
1233 
1234 			/* end service period after last frame */
1235 			if (skb_queue_empty(&frames)) {
1236 				if (reason == IEEE80211_FRAME_RELEASE_UAPSD &&
1237 				    qoshdr)
1238 					*qoshdr |= IEEE80211_QOS_CTL_EOSP;
1239 
1240 				info->flags |= IEEE80211_TX_STATUS_EOSP |
1241 					       IEEE80211_TX_CTL_REQ_TX_STATUS;
1242 			}
1243 
1244 			if (qoshdr)
1245 				tids |= BIT(*qoshdr & IEEE80211_QOS_CTL_TID_MASK);
1246 			else
1247 				tids |= BIT(0);
1248 
1249 			__skb_queue_tail(&pending, skb);
1250 		}
1251 
1252 		drv_allow_buffered_frames(local, sta, tids, num,
1253 					  reason, more_data);
1254 
1255 		ieee80211_add_pending_skbs(local, &pending);
1256 
1257 		sta_info_recalc_tim(sta);
1258 	} else {
1259 		/*
1260 		 * We need to release a frame that is buffered somewhere in the
1261 		 * driver ... it'll have to handle that.
1262 		 * Note that, as per the comment above, it'll also have to see
1263 		 * if there is more than just one frame on the specific TID that
1264 		 * we're releasing from, and it needs to set the more-data bit
1265 		 * accordingly if we tell it that there's no more data. If we do
1266 		 * tell it there's more data, then of course the more-data bit
1267 		 * needs to be set anyway.
1268 		 */
1269 		drv_release_buffered_frames(local, sta, driver_release_tids,
1270 					    n_frames, reason, more_data);
1271 
1272 		/*
1273 		 * Note that we don't recalculate the TIM bit here as it would
1274 		 * most likely have no effect at all unless the driver told us
1275 		 * that the TID became empty before returning here from the
1276 		 * release function.
1277 		 * Either way, however, when the driver tells us that the TID
1278 		 * became empty we'll do the TIM recalculation.
1279 		 */
1280 	}
1281 }
1282 
1283 void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta)
1284 {
1285 	u8 ignore_for_response = sta->sta.uapsd_queues;
1286 
1287 	/*
1288 	 * If all ACs are delivery-enabled then we should reply
1289 	 * from any of them, if only some are enabled we reply
1290 	 * only from the non-enabled ones.
1291 	 */
1292 	if (ignore_for_response == BIT(IEEE80211_NUM_ACS) - 1)
1293 		ignore_for_response = 0;
1294 
1295 	ieee80211_sta_ps_deliver_response(sta, 1, ignore_for_response,
1296 					  IEEE80211_FRAME_RELEASE_PSPOLL);
1297 }
1298 
1299 void ieee80211_sta_ps_deliver_uapsd(struct sta_info *sta)
1300 {
1301 	int n_frames = sta->sta.max_sp;
1302 	u8 delivery_enabled = sta->sta.uapsd_queues;
1303 
1304 	/*
1305 	 * If we ever grow support for TSPEC this might happen if
1306 	 * the TSPEC update from hostapd comes in between a trigger
1307 	 * frame setting WLAN_STA_UAPSD in the RX path and this
1308 	 * actually getting called.
1309 	 */
1310 	if (!delivery_enabled)
1311 		return;
1312 
1313 	switch (sta->sta.max_sp) {
1314 	case 1:
1315 		n_frames = 2;
1316 		break;
1317 	case 2:
1318 		n_frames = 4;
1319 		break;
1320 	case 3:
1321 		n_frames = 6;
1322 		break;
1323 	case 0:
1324 		/* XXX: what is a good value? */
1325 		n_frames = 8;
1326 		break;
1327 	}
1328 
1329 	ieee80211_sta_ps_deliver_response(sta, n_frames, ~delivery_enabled,
1330 					  IEEE80211_FRAME_RELEASE_UAPSD);
1331 }
1332 
1333 void ieee80211_sta_block_awake(struct ieee80211_hw *hw,
1334 			       struct ieee80211_sta *pubsta, bool block)
1335 {
1336 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1337 
1338 	trace_api_sta_block_awake(sta->local, pubsta, block);
1339 
1340 	if (block)
1341 		set_sta_flag(sta, WLAN_STA_PS_DRIVER);
1342 	else if (test_sta_flag(sta, WLAN_STA_PS_DRIVER))
1343 		ieee80211_queue_work(hw, &sta->drv_unblock_wk);
1344 }
1345 EXPORT_SYMBOL(ieee80211_sta_block_awake);
1346 
1347 void ieee80211_sta_eosp_irqsafe(struct ieee80211_sta *pubsta)
1348 {
1349 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1350 	struct ieee80211_local *local = sta->local;
1351 	struct sk_buff *skb;
1352 	struct skb_eosp_msg_data *data;
1353 
1354 	trace_api_eosp(local, pubsta);
1355 
1356 	skb = alloc_skb(0, GFP_ATOMIC);
1357 	if (!skb) {
1358 		/* too bad ... but race is better than loss */
1359 		clear_sta_flag(sta, WLAN_STA_SP);
1360 		return;
1361 	}
1362 
1363 	data = (void *)skb->cb;
1364 	memcpy(data->sta, pubsta->addr, ETH_ALEN);
1365 	memcpy(data->iface, sta->sdata->vif.addr, ETH_ALEN);
1366 	skb->pkt_type = IEEE80211_EOSP_MSG;
1367 	skb_queue_tail(&local->skb_queue, skb);
1368 	tasklet_schedule(&local->tasklet);
1369 }
1370 EXPORT_SYMBOL(ieee80211_sta_eosp_irqsafe);
1371 
1372 void ieee80211_sta_set_buffered(struct ieee80211_sta *pubsta,
1373 				u8 tid, bool buffered)
1374 {
1375 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1376 
1377 	if (WARN_ON(tid >= IEEE80211_NUM_TIDS))
1378 		return;
1379 
1380 	if (buffered)
1381 		set_bit(tid, &sta->driver_buffered_tids);
1382 	else
1383 		clear_bit(tid, &sta->driver_buffered_tids);
1384 
1385 	sta_info_recalc_tim(sta);
1386 }
1387 EXPORT_SYMBOL(ieee80211_sta_set_buffered);
1388 
1389 int sta_info_move_state(struct sta_info *sta,
1390 			enum ieee80211_sta_state new_state)
1391 {
1392 	might_sleep();
1393 
1394 	if (sta->sta_state == new_state)
1395 		return 0;
1396 
1397 	/* check allowed transitions first */
1398 
1399 	switch (new_state) {
1400 	case IEEE80211_STA_NONE:
1401 		if (sta->sta_state != IEEE80211_STA_AUTH)
1402 			return -EINVAL;
1403 		break;
1404 	case IEEE80211_STA_AUTH:
1405 		if (sta->sta_state != IEEE80211_STA_NONE &&
1406 		    sta->sta_state != IEEE80211_STA_ASSOC)
1407 			return -EINVAL;
1408 		break;
1409 	case IEEE80211_STA_ASSOC:
1410 		if (sta->sta_state != IEEE80211_STA_AUTH &&
1411 		    sta->sta_state != IEEE80211_STA_AUTHORIZED)
1412 			return -EINVAL;
1413 		break;
1414 	case IEEE80211_STA_AUTHORIZED:
1415 		if (sta->sta_state != IEEE80211_STA_ASSOC)
1416 			return -EINVAL;
1417 		break;
1418 	default:
1419 		WARN(1, "invalid state %d", new_state);
1420 		return -EINVAL;
1421 	}
1422 
1423 	sta_dbg(sta->sdata, "moving STA %pM to state %d\n",
1424 		sta->sta.addr, new_state);
1425 
1426 	/*
1427 	 * notify the driver before the actual changes so it can
1428 	 * fail the transition
1429 	 */
1430 	if (test_sta_flag(sta, WLAN_STA_INSERTED)) {
1431 		int err = drv_sta_state(sta->local, sta->sdata, sta,
1432 					sta->sta_state, new_state);
1433 		if (err)
1434 			return err;
1435 	}
1436 
1437 	/* reflect the change in all state variables */
1438 
1439 	switch (new_state) {
1440 	case IEEE80211_STA_NONE:
1441 		if (sta->sta_state == IEEE80211_STA_AUTH)
1442 			clear_bit(WLAN_STA_AUTH, &sta->_flags);
1443 		break;
1444 	case IEEE80211_STA_AUTH:
1445 		if (sta->sta_state == IEEE80211_STA_NONE)
1446 			set_bit(WLAN_STA_AUTH, &sta->_flags);
1447 		else if (sta->sta_state == IEEE80211_STA_ASSOC)
1448 			clear_bit(WLAN_STA_ASSOC, &sta->_flags);
1449 		break;
1450 	case IEEE80211_STA_ASSOC:
1451 		if (sta->sta_state == IEEE80211_STA_AUTH) {
1452 			set_bit(WLAN_STA_ASSOC, &sta->_flags);
1453 		} else if (sta->sta_state == IEEE80211_STA_AUTHORIZED) {
1454 			if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1455 			    (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1456 			     !sta->sdata->u.vlan.sta))
1457 				atomic_dec(&sta->sdata->bss->num_mcast_sta);
1458 			clear_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
1459 		}
1460 		break;
1461 	case IEEE80211_STA_AUTHORIZED:
1462 		if (sta->sta_state == IEEE80211_STA_ASSOC) {
1463 			if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
1464 			    (sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN &&
1465 			     !sta->sdata->u.vlan.sta))
1466 				atomic_inc(&sta->sdata->bss->num_mcast_sta);
1467 			set_bit(WLAN_STA_AUTHORIZED, &sta->_flags);
1468 		}
1469 		break;
1470 	default:
1471 		break;
1472 	}
1473 
1474 	sta->sta_state = new_state;
1475 
1476 	return 0;
1477 }
1478