xref: /linux/net/mac80211/status.c (revision d0b73b488c55df905ea8faaad079f8535629ed26)
1 /*
2  * Copyright 2002-2005, Instant802 Networks, Inc.
3  * Copyright 2005-2006, Devicescape Software, Inc.
4  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5  * Copyright 2008-2010	Johannes Berg <johannes@sipsolutions.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 
12 #include <linux/export.h>
13 #include <linux/etherdevice.h>
14 #include <net/mac80211.h>
15 #include <asm/unaligned.h>
16 #include "ieee80211_i.h"
17 #include "rate.h"
18 #include "mesh.h"
19 #include "led.h"
20 #include "wme.h"
21 
22 
23 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
24 				 struct sk_buff *skb)
25 {
26 	struct ieee80211_local *local = hw_to_local(hw);
27 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
28 	int tmp;
29 
30 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
31 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
32 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
33 	tmp = skb_queue_len(&local->skb_queue) +
34 		skb_queue_len(&local->skb_queue_unreliable);
35 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
36 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
37 		ieee80211_free_txskb(hw, skb);
38 		tmp--;
39 		I802_DEBUG_INC(local->tx_status_drop);
40 	}
41 	tasklet_schedule(&local->tasklet);
42 }
43 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
44 
45 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
46 					    struct sta_info *sta,
47 					    struct sk_buff *skb)
48 {
49 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
50 	struct ieee80211_hdr *hdr = (void *)skb->data;
51 	int ac;
52 
53 	/*
54 	 * This skb 'survived' a round-trip through the driver, and
55 	 * hopefully the driver didn't mangle it too badly. However,
56 	 * we can definitely not rely on the control information
57 	 * being correct. Clear it so we don't get junk there, and
58 	 * indicate that it needs new processing, but must not be
59 	 * modified/encrypted again.
60 	 */
61 	memset(&info->control, 0, sizeof(info->control));
62 
63 	info->control.jiffies = jiffies;
64 	info->control.vif = &sta->sdata->vif;
65 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
66 		       IEEE80211_TX_INTFL_RETRANSMISSION;
67 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
68 
69 	sta->tx_filtered_count++;
70 
71 	/*
72 	 * Clear more-data bit on filtered frames, it might be set
73 	 * but later frames might time out so it might have to be
74 	 * clear again ... It's all rather unlikely (this frame
75 	 * should time out first, right?) but let's not confuse
76 	 * peers unnecessarily.
77 	 */
78 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
79 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
80 
81 	if (ieee80211_is_data_qos(hdr->frame_control)) {
82 		u8 *p = ieee80211_get_qos_ctl(hdr);
83 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
84 
85 		/*
86 		 * Clear EOSP if set, this could happen e.g.
87 		 * if an absence period (us being a P2P GO)
88 		 * shortens the SP.
89 		 */
90 		if (*p & IEEE80211_QOS_CTL_EOSP)
91 			*p &= ~IEEE80211_QOS_CTL_EOSP;
92 		ac = ieee802_1d_to_ac[tid & 7];
93 	} else {
94 		ac = IEEE80211_AC_BE;
95 	}
96 
97 	/*
98 	 * Clear the TX filter mask for this STA when sending the next
99 	 * packet. If the STA went to power save mode, this will happen
100 	 * when it wakes up for the next time.
101 	 */
102 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
103 
104 	/*
105 	 * This code races in the following way:
106 	 *
107 	 *  (1) STA sends frame indicating it will go to sleep and does so
108 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
109 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
110 	 *  (4) we get TX status before having processed the frame and
111 	 *	knowing that the STA has gone to sleep.
112 	 *
113 	 * This is actually quite unlikely even when both those events are
114 	 * processed from interrupts coming in quickly after one another or
115 	 * even at the same time because we queue both TX status events and
116 	 * RX frames to be processed by a tasklet and process them in the
117 	 * same order that they were received or TX status last. Hence, there
118 	 * is no race as long as the frame RX is processed before the next TX
119 	 * status, which drivers can ensure, see below.
120 	 *
121 	 * Note that this can only happen if the hardware or firmware can
122 	 * actually add STAs to the filter list, if this is done by the
123 	 * driver in response to set_tim() (which will only reduce the race
124 	 * this whole filtering tries to solve, not completely solve it)
125 	 * this situation cannot happen.
126 	 *
127 	 * To completely solve this race drivers need to make sure that they
128 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
129 	 *	functions and
130 	 *  (b) always process RX events before TX status events if ordering
131 	 *      can be unknown, for example with different interrupt status
132 	 *	bits.
133 	 *  (c) if PS mode transitions are manual (i.e. the flag
134 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
135 	 *      changes before calling TX status events if ordering can be
136 	 *	unknown.
137 	 */
138 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
139 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
140 		skb_queue_tail(&sta->tx_filtered[ac], skb);
141 		sta_info_recalc_tim(sta);
142 
143 		if (!timer_pending(&local->sta_cleanup))
144 			mod_timer(&local->sta_cleanup,
145 				  round_jiffies(jiffies +
146 						STA_INFO_CLEANUP_INTERVAL));
147 		return;
148 	}
149 
150 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
151 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
152 		/* Software retry the packet once */
153 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
154 		ieee80211_add_pending_skb(local, skb);
155 		return;
156 	}
157 
158 	ps_dbg_ratelimited(sta->sdata,
159 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
160 			   skb_queue_len(&sta->tx_filtered[ac]),
161 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
162 	ieee80211_free_txskb(&local->hw, skb);
163 }
164 
165 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
166 {
167 	struct tid_ampdu_tx *tid_tx;
168 
169 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
170 	if (!tid_tx || !tid_tx->bar_pending)
171 		return;
172 
173 	tid_tx->bar_pending = false;
174 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
175 }
176 
177 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
178 {
179 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
180 	struct ieee80211_local *local = sta->local;
181 	struct ieee80211_sub_if_data *sdata = sta->sdata;
182 
183 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
184 		struct ieee80211_hdr *hdr = (void *) skb->data;
185 		u8 *qc = ieee80211_get_qos_ctl(hdr);
186 		u16 tid = qc[0] & 0xf;
187 
188 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
189 	}
190 
191 	if (ieee80211_is_action(mgmt->frame_control) &&
192 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
193 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
194 	    sdata->vif.type == NL80211_IFTYPE_STATION &&
195 	    ieee80211_sdata_running(sdata)) {
196 		/*
197 		 * This update looks racy, but isn't -- if we come
198 		 * here we've definitely got a station that we're
199 		 * talking to, and on a managed interface that can
200 		 * only be the AP. And the only other place updating
201 		 * this variable in managed mode is before association.
202 		 */
203 		switch (mgmt->u.action.u.ht_smps.smps_control) {
204 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
205 			sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
206 			break;
207 		case WLAN_HT_SMPS_CONTROL_STATIC:
208 			sdata->smps_mode = IEEE80211_SMPS_STATIC;
209 			break;
210 		case WLAN_HT_SMPS_CONTROL_DISABLED:
211 		default: /* shouldn't happen since we don't send that */
212 			sdata->smps_mode = IEEE80211_SMPS_OFF;
213 			break;
214 		}
215 
216 		ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
217 	}
218 }
219 
220 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
221 {
222 	struct tid_ampdu_tx *tid_tx;
223 
224 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
225 	if (!tid_tx)
226 		return;
227 
228 	tid_tx->failed_bar_ssn = ssn;
229 	tid_tx->bar_pending = true;
230 }
231 
232 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
233 {
234 	int len = sizeof(struct ieee80211_radiotap_header);
235 
236 	/* IEEE80211_RADIOTAP_RATE rate */
237 	if (info->status.rates[0].idx >= 0 &&
238 	    !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
239 		len += 2;
240 
241 	/* IEEE80211_RADIOTAP_TX_FLAGS */
242 	len += 2;
243 
244 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
245 	len += 1;
246 
247 	/* IEEE80211_TX_RC_MCS */
248 	if (info->status.rates[0].idx >= 0 &&
249 	    info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
250 		len += 3;
251 
252 	return len;
253 }
254 
255 static void ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band
256 					     *sband, struct sk_buff *skb,
257 					     int retry_count, int rtap_len)
258 {
259 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
260 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
261 	struct ieee80211_radiotap_header *rthdr;
262 	unsigned char *pos;
263 	u16 txflags;
264 
265 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
266 
267 	memset(rthdr, 0, rtap_len);
268 	rthdr->it_len = cpu_to_le16(rtap_len);
269 	rthdr->it_present =
270 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
271 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
272 	pos = (unsigned char *)(rthdr + 1);
273 
274 	/*
275 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
276 	 *	extensions proposal contains, we can actually report
277 	 *	the whole set of tries we did.
278 	 */
279 
280 	/* IEEE80211_RADIOTAP_RATE */
281 	if (info->status.rates[0].idx >= 0 &&
282 	    !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) {
283 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
284 		*pos = sband->bitrates[info->status.rates[0].idx].bitrate / 5;
285 		/* padding for tx flags */
286 		pos += 2;
287 	}
288 
289 	/* IEEE80211_RADIOTAP_TX_FLAGS */
290 	txflags = 0;
291 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
292 	    !is_multicast_ether_addr(hdr->addr1))
293 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
294 
295 	if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
296 	    (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
297 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
298 	else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
299 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
300 
301 	put_unaligned_le16(txflags, pos);
302 	pos += 2;
303 
304 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
305 	/* for now report the total retry_count */
306 	*pos = retry_count;
307 	pos++;
308 
309 	/* IEEE80211_TX_RC_MCS */
310 	if (info->status.rates[0].idx >= 0 &&
311 	    info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
312 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
313 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
314 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
315 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
316 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
317 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
318 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
319 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
320 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
321 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
322 		pos[2] = info->status.rates[0].idx;
323 		pos += 3;
324 	}
325 
326 }
327 
328 static void ieee80211_report_used_skb(struct ieee80211_local *local,
329 				      struct sk_buff *skb, bool dropped)
330 {
331 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
332 	struct ieee80211_hdr *hdr = (void *)skb->data;
333 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
334 
335 	if (dropped)
336 		acked = false;
337 
338 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
339 		struct ieee80211_sub_if_data *sdata = NULL;
340 		struct ieee80211_sub_if_data *iter_sdata;
341 		u64 cookie = (unsigned long)skb;
342 
343 		rcu_read_lock();
344 
345 		if (skb->dev) {
346 			list_for_each_entry_rcu(iter_sdata, &local->interfaces,
347 						list) {
348 				if (!iter_sdata->dev)
349 					continue;
350 
351 				if (skb->dev == iter_sdata->dev) {
352 					sdata = iter_sdata;
353 					break;
354 				}
355 			}
356 		} else {
357 			sdata = rcu_dereference(local->p2p_sdata);
358 		}
359 
360 		if (!sdata)
361 			skb->dev = NULL;
362 		else if (ieee80211_is_nullfunc(hdr->frame_control) ||
363 			 ieee80211_is_qos_nullfunc(hdr->frame_control)) {
364 			cfg80211_probe_status(sdata->dev, hdr->addr1,
365 					      cookie, acked, GFP_ATOMIC);
366 		} else {
367 			cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data,
368 						skb->len, acked, GFP_ATOMIC);
369 		}
370 
371 		rcu_read_unlock();
372 	}
373 
374 	if (unlikely(info->ack_frame_id)) {
375 		struct sk_buff *ack_skb;
376 		unsigned long flags;
377 
378 		spin_lock_irqsave(&local->ack_status_lock, flags);
379 		ack_skb = idr_find(&local->ack_status_frames,
380 				   info->ack_frame_id);
381 		if (ack_skb)
382 			idr_remove(&local->ack_status_frames,
383 				   info->ack_frame_id);
384 		spin_unlock_irqrestore(&local->ack_status_lock, flags);
385 
386 		if (ack_skb) {
387 			if (!dropped) {
388 				/* consumes ack_skb */
389 				skb_complete_wifi_ack(ack_skb, acked);
390 			} else {
391 				dev_kfree_skb_any(ack_skb);
392 			}
393 		}
394 	}
395 }
396 
397 /*
398  * Use a static threshold for now, best value to be determined
399  * by testing ...
400  * Should it depend on:
401  *  - on # of retransmissions
402  *  - current throughput (higher value for higher tpt)?
403  */
404 #define STA_LOST_PKT_THRESHOLD	50
405 
406 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
407 {
408 	struct sk_buff *skb2;
409 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
410 	struct ieee80211_local *local = hw_to_local(hw);
411 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
412 	__le16 fc;
413 	struct ieee80211_supported_band *sband;
414 	struct ieee80211_sub_if_data *sdata;
415 	struct net_device *prev_dev = NULL;
416 	struct sta_info *sta, *tmp;
417 	int retry_count = -1, i;
418 	int rates_idx = -1;
419 	bool send_to_cooked;
420 	bool acked;
421 	struct ieee80211_bar *bar;
422 	int rtap_len;
423 
424 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
425 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
426 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
427 			/* just the first aggr frame carry status info */
428 			info->status.rates[i].idx = -1;
429 			info->status.rates[i].count = 0;
430 			break;
431 		} else if (info->status.rates[i].idx < 0) {
432 			break;
433 		} else if (i >= hw->max_report_rates) {
434 			/* the HW cannot have attempted that rate */
435 			info->status.rates[i].idx = -1;
436 			info->status.rates[i].count = 0;
437 			break;
438 		}
439 
440 		retry_count += info->status.rates[i].count;
441 	}
442 	rates_idx = i - 1;
443 
444 	if (retry_count < 0)
445 		retry_count = 0;
446 
447 	rcu_read_lock();
448 
449 	sband = local->hw.wiphy->bands[info->band];
450 	fc = hdr->frame_control;
451 
452 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
453 		/* skip wrong virtual interface */
454 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
455 			continue;
456 
457 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
458 			clear_sta_flag(sta, WLAN_STA_SP);
459 
460 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
461 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
462 			/*
463 			 * The STA is in power save mode, so assume
464 			 * that this TX packet failed because of that.
465 			 */
466 			ieee80211_handle_filtered_frame(local, sta, skb);
467 			rcu_read_unlock();
468 			return;
469 		}
470 
471 		if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
472 		    (rates_idx != -1))
473 			sta->last_tx_rate = info->status.rates[rates_idx];
474 
475 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
476 		    (ieee80211_is_data_qos(fc))) {
477 			u16 tid, ssn;
478 			u8 *qc;
479 
480 			qc = ieee80211_get_qos_ctl(hdr);
481 			tid = qc[0] & 0xf;
482 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
483 						& IEEE80211_SCTL_SEQ);
484 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
485 					   tid, ssn);
486 		}
487 
488 		if (!acked && ieee80211_is_back_req(fc)) {
489 			u16 tid, control;
490 
491 			/*
492 			 * BAR failed, store the last SSN and retry sending
493 			 * the BAR when the next unicast transmission on the
494 			 * same TID succeeds.
495 			 */
496 			bar = (struct ieee80211_bar *) skb->data;
497 			control = le16_to_cpu(bar->control);
498 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
499 				u16 ssn = le16_to_cpu(bar->start_seq_num);
500 
501 				tid = (control &
502 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
503 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
504 
505 				if (local->hw.flags &
506 				    IEEE80211_HW_TEARDOWN_AGGR_ON_BAR_FAIL)
507 					ieee80211_stop_tx_ba_session(&sta->sta, tid);
508 				else
509 					ieee80211_set_bar_pending(sta, tid, ssn);
510 			}
511 		}
512 
513 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
514 			ieee80211_handle_filtered_frame(local, sta, skb);
515 			rcu_read_unlock();
516 			return;
517 		} else {
518 			if (!acked)
519 				sta->tx_retry_failed++;
520 			sta->tx_retry_count += retry_count;
521 		}
522 
523 		rate_control_tx_status(local, sband, sta, skb);
524 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
525 			ieee80211s_update_metric(local, sta, skb);
526 
527 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
528 			ieee80211_frame_acked(sta, skb);
529 
530 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
531 		    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
532 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
533 
534 		if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
535 			if (info->flags & IEEE80211_TX_STAT_ACK) {
536 				if (sta->lost_packets)
537 					sta->lost_packets = 0;
538 			} else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
539 				cfg80211_cqm_pktloss_notify(sta->sdata->dev,
540 							    sta->sta.addr,
541 							    sta->lost_packets,
542 							    GFP_ATOMIC);
543 				sta->lost_packets = 0;
544 			}
545 		}
546 
547 		if (acked)
548 			sta->last_ack_signal = info->status.ack_signal;
549 	}
550 
551 	rcu_read_unlock();
552 
553 	ieee80211_led_tx(local, 0);
554 
555 	/* SNMP counters
556 	 * Fragments are passed to low-level drivers as separate skbs, so these
557 	 * are actually fragments, not frames. Update frame counters only for
558 	 * the first fragment of the frame. */
559 	if (info->flags & IEEE80211_TX_STAT_ACK) {
560 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
561 			local->dot11TransmittedFrameCount++;
562 			if (is_multicast_ether_addr(hdr->addr1))
563 				local->dot11MulticastTransmittedFrameCount++;
564 			if (retry_count > 0)
565 				local->dot11RetryCount++;
566 			if (retry_count > 1)
567 				local->dot11MultipleRetryCount++;
568 		}
569 
570 		/* This counter shall be incremented for an acknowledged MPDU
571 		 * with an individual address in the address 1 field or an MPDU
572 		 * with a multicast address in the address 1 field of type Data
573 		 * or Management. */
574 		if (!is_multicast_ether_addr(hdr->addr1) ||
575 		    ieee80211_is_data(fc) ||
576 		    ieee80211_is_mgmt(fc))
577 			local->dot11TransmittedFragmentCount++;
578 	} else {
579 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
580 			local->dot11FailedCount++;
581 	}
582 
583 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
584 	    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
585 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
586 	    local->ps_sdata && !(local->scanning)) {
587 		if (info->flags & IEEE80211_TX_STAT_ACK) {
588 			local->ps_sdata->u.mgd.flags |=
589 					IEEE80211_STA_NULLFUNC_ACKED;
590 		} else
591 			mod_timer(&local->dynamic_ps_timer, jiffies +
592 					msecs_to_jiffies(10));
593 	}
594 
595 	ieee80211_report_used_skb(local, skb, false);
596 
597 	/* this was a transmitted frame, but now we want to reuse it */
598 	skb_orphan(skb);
599 
600 	/* Need to make a copy before skb->cb gets cleared */
601 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
602 			 !(ieee80211_is_data(fc));
603 
604 	/*
605 	 * This is a bit racy but we can avoid a lot of work
606 	 * with this test...
607 	 */
608 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
609 		dev_kfree_skb(skb);
610 		return;
611 	}
612 
613 	/* send frame to monitor interfaces now */
614 	rtap_len = ieee80211_tx_radiotap_len(info);
615 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
616 		pr_err("ieee80211_tx_status: headroom too small\n");
617 		dev_kfree_skb(skb);
618 		return;
619 	}
620 	ieee80211_add_tx_radiotap_header(sband, skb, retry_count, rtap_len);
621 
622 	/* XXX: is this sufficient for BPF? */
623 	skb_set_mac_header(skb, 0);
624 	skb->ip_summed = CHECKSUM_UNNECESSARY;
625 	skb->pkt_type = PACKET_OTHERHOST;
626 	skb->protocol = htons(ETH_P_802_2);
627 	memset(skb->cb, 0, sizeof(skb->cb));
628 
629 	rcu_read_lock();
630 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
631 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
632 			if (!ieee80211_sdata_running(sdata))
633 				continue;
634 
635 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
636 			    !send_to_cooked)
637 				continue;
638 
639 			if (prev_dev) {
640 				skb2 = skb_clone(skb, GFP_ATOMIC);
641 				if (skb2) {
642 					skb2->dev = prev_dev;
643 					netif_rx(skb2);
644 				}
645 			}
646 
647 			prev_dev = sdata->dev;
648 		}
649 	}
650 	if (prev_dev) {
651 		skb->dev = prev_dev;
652 		netif_rx(skb);
653 		skb = NULL;
654 	}
655 	rcu_read_unlock();
656 	dev_kfree_skb(skb);
657 }
658 EXPORT_SYMBOL(ieee80211_tx_status);
659 
660 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
661 {
662 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
663 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
664 				    num_packets, GFP_ATOMIC);
665 }
666 EXPORT_SYMBOL(ieee80211_report_low_ack);
667 
668 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
669 {
670 	struct ieee80211_local *local = hw_to_local(hw);
671 
672 	ieee80211_report_used_skb(local, skb, true);
673 	dev_kfree_skb_any(skb);
674 }
675 EXPORT_SYMBOL(ieee80211_free_txskb);
676 
677 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
678 			      struct sk_buff_head *skbs)
679 {
680 	struct sk_buff *skb;
681 
682 	while ((skb = __skb_dequeue(skbs)))
683 		ieee80211_free_txskb(hw, skb);
684 }
685