xref: /openbmc/linux/net/mac80211/status.c (revision 8684014d)
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  * Copyright 2013-2014  Intel Mobile Communications GmbH
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12 
13 #include <linux/export.h>
14 #include <linux/etherdevice.h>
15 #include <linux/time.h>
16 #include <net/mac80211.h>
17 #include <asm/unaligned.h>
18 #include "ieee80211_i.h"
19 #include "rate.h"
20 #include "mesh.h"
21 #include "led.h"
22 #include "wme.h"
23 
24 
25 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
26 				 struct sk_buff *skb)
27 {
28 	struct ieee80211_local *local = hw_to_local(hw);
29 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
30 	int tmp;
31 
32 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
33 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
34 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
35 	tmp = skb_queue_len(&local->skb_queue) +
36 		skb_queue_len(&local->skb_queue_unreliable);
37 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
38 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
39 		ieee80211_free_txskb(hw, skb);
40 		tmp--;
41 		I802_DEBUG_INC(local->tx_status_drop);
42 	}
43 	tasklet_schedule(&local->tasklet);
44 }
45 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
46 
47 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
48 					    struct sta_info *sta,
49 					    struct sk_buff *skb)
50 {
51 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
52 	struct ieee80211_hdr *hdr = (void *)skb->data;
53 	int ac;
54 
55 	/*
56 	 * This skb 'survived' a round-trip through the driver, and
57 	 * hopefully the driver didn't mangle it too badly. However,
58 	 * we can definitely not rely on the control information
59 	 * being correct. Clear it so we don't get junk there, and
60 	 * indicate that it needs new processing, but must not be
61 	 * modified/encrypted again.
62 	 */
63 	memset(&info->control, 0, sizeof(info->control));
64 
65 	info->control.jiffies = jiffies;
66 	info->control.vif = &sta->sdata->vif;
67 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
68 		       IEEE80211_TX_INTFL_RETRANSMISSION;
69 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
70 
71 	sta->tx_filtered_count++;
72 
73 	/*
74 	 * Clear more-data bit on filtered frames, it might be set
75 	 * but later frames might time out so it might have to be
76 	 * clear again ... It's all rather unlikely (this frame
77 	 * should time out first, right?) but let's not confuse
78 	 * peers unnecessarily.
79 	 */
80 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
81 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
82 
83 	if (ieee80211_is_data_qos(hdr->frame_control)) {
84 		u8 *p = ieee80211_get_qos_ctl(hdr);
85 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
86 
87 		/*
88 		 * Clear EOSP if set, this could happen e.g.
89 		 * if an absence period (us being a P2P GO)
90 		 * shortens the SP.
91 		 */
92 		if (*p & IEEE80211_QOS_CTL_EOSP)
93 			*p &= ~IEEE80211_QOS_CTL_EOSP;
94 		ac = ieee802_1d_to_ac[tid & 7];
95 	} else {
96 		ac = IEEE80211_AC_BE;
97 	}
98 
99 	/*
100 	 * Clear the TX filter mask for this STA when sending the next
101 	 * packet. If the STA went to power save mode, this will happen
102 	 * when it wakes up for the next time.
103 	 */
104 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
105 
106 	/*
107 	 * This code races in the following way:
108 	 *
109 	 *  (1) STA sends frame indicating it will go to sleep and does so
110 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
111 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
112 	 *  (4) we get TX status before having processed the frame and
113 	 *	knowing that the STA has gone to sleep.
114 	 *
115 	 * This is actually quite unlikely even when both those events are
116 	 * processed from interrupts coming in quickly after one another or
117 	 * even at the same time because we queue both TX status events and
118 	 * RX frames to be processed by a tasklet and process them in the
119 	 * same order that they were received or TX status last. Hence, there
120 	 * is no race as long as the frame RX is processed before the next TX
121 	 * status, which drivers can ensure, see below.
122 	 *
123 	 * Note that this can only happen if the hardware or firmware can
124 	 * actually add STAs to the filter list, if this is done by the
125 	 * driver in response to set_tim() (which will only reduce the race
126 	 * this whole filtering tries to solve, not completely solve it)
127 	 * this situation cannot happen.
128 	 *
129 	 * To completely solve this race drivers need to make sure that they
130 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
131 	 *	functions and
132 	 *  (b) always process RX events before TX status events if ordering
133 	 *      can be unknown, for example with different interrupt status
134 	 *	bits.
135 	 *  (c) if PS mode transitions are manual (i.e. the flag
136 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
137 	 *      changes before calling TX status events if ordering can be
138 	 *	unknown.
139 	 */
140 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
141 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
142 		skb_queue_tail(&sta->tx_filtered[ac], skb);
143 		sta_info_recalc_tim(sta);
144 
145 		if (!timer_pending(&local->sta_cleanup))
146 			mod_timer(&local->sta_cleanup,
147 				  round_jiffies(jiffies +
148 						STA_INFO_CLEANUP_INTERVAL));
149 		return;
150 	}
151 
152 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
153 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
154 		/* Software retry the packet once */
155 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
156 		ieee80211_add_pending_skb(local, skb);
157 		return;
158 	}
159 
160 	ps_dbg_ratelimited(sta->sdata,
161 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
162 			   skb_queue_len(&sta->tx_filtered[ac]),
163 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
164 	ieee80211_free_txskb(&local->hw, skb);
165 }
166 
167 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
168 {
169 	struct tid_ampdu_tx *tid_tx;
170 
171 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
172 	if (!tid_tx || !tid_tx->bar_pending)
173 		return;
174 
175 	tid_tx->bar_pending = false;
176 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
177 }
178 
179 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
180 {
181 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
182 	struct ieee80211_local *local = sta->local;
183 	struct ieee80211_sub_if_data *sdata = sta->sdata;
184 
185 	if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
186 		sta->last_rx = jiffies;
187 
188 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
189 		struct ieee80211_hdr *hdr = (void *) skb->data;
190 		u8 *qc = ieee80211_get_qos_ctl(hdr);
191 		u16 tid = qc[0] & 0xf;
192 
193 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
194 	}
195 
196 	if (ieee80211_is_action(mgmt->frame_control) &&
197 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
198 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
199 	    ieee80211_sdata_running(sdata)) {
200 		enum ieee80211_smps_mode smps_mode;
201 
202 		switch (mgmt->u.action.u.ht_smps.smps_control) {
203 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
204 			smps_mode = IEEE80211_SMPS_DYNAMIC;
205 			break;
206 		case WLAN_HT_SMPS_CONTROL_STATIC:
207 			smps_mode = IEEE80211_SMPS_STATIC;
208 			break;
209 		case WLAN_HT_SMPS_CONTROL_DISABLED:
210 		default: /* shouldn't happen since we don't send that */
211 			smps_mode = IEEE80211_SMPS_OFF;
212 			break;
213 		}
214 
215 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
216 			/*
217 			 * This update looks racy, but isn't -- if we come
218 			 * here we've definitely got a station that we're
219 			 * talking to, and on a managed interface that can
220 			 * only be the AP. And the only other place updating
221 			 * this variable in managed mode is before association.
222 			 */
223 			sdata->smps_mode = smps_mode;
224 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
225 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
226 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
227 			sta->known_smps_mode = smps_mode;
228 		}
229 	}
230 }
231 
232 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
233 {
234 	struct tid_ampdu_tx *tid_tx;
235 
236 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
237 	if (!tid_tx)
238 		return;
239 
240 	tid_tx->failed_bar_ssn = ssn;
241 	tid_tx->bar_pending = true;
242 }
243 
244 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
245 {
246 	int len = sizeof(struct ieee80211_radiotap_header);
247 
248 	/* IEEE80211_RADIOTAP_RATE rate */
249 	if (info->status.rates[0].idx >= 0 &&
250 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
251 					     IEEE80211_TX_RC_VHT_MCS)))
252 		len += 2;
253 
254 	/* IEEE80211_RADIOTAP_TX_FLAGS */
255 	len += 2;
256 
257 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
258 	len += 1;
259 
260 	/* IEEE80211_RADIOTAP_MCS
261 	 * IEEE80211_RADIOTAP_VHT */
262 	if (info->status.rates[0].idx >= 0) {
263 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
264 			len += 3;
265 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
266 			len = ALIGN(len, 2) + 12;
267 	}
268 
269 	return len;
270 }
271 
272 static void
273 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
274 				 struct ieee80211_supported_band *sband,
275 				 struct sk_buff *skb, int retry_count,
276 				 int rtap_len, int shift)
277 {
278 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
279 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
280 	struct ieee80211_radiotap_header *rthdr;
281 	unsigned char *pos;
282 	u16 txflags;
283 
284 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
285 
286 	memset(rthdr, 0, rtap_len);
287 	rthdr->it_len = cpu_to_le16(rtap_len);
288 	rthdr->it_present =
289 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
290 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
291 	pos = (unsigned char *)(rthdr + 1);
292 
293 	/*
294 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
295 	 *	extensions proposal contains, we can actually report
296 	 *	the whole set of tries we did.
297 	 */
298 
299 	/* IEEE80211_RADIOTAP_RATE */
300 	if (info->status.rates[0].idx >= 0 &&
301 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
302 					     IEEE80211_TX_RC_VHT_MCS))) {
303 		u16 rate;
304 
305 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
306 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
307 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
308 		/* padding for tx flags */
309 		pos += 2;
310 	}
311 
312 	/* IEEE80211_RADIOTAP_TX_FLAGS */
313 	txflags = 0;
314 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
315 	    !is_multicast_ether_addr(hdr->addr1))
316 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
317 
318 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
319 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
320 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
321 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
322 
323 	put_unaligned_le16(txflags, pos);
324 	pos += 2;
325 
326 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
327 	/* for now report the total retry_count */
328 	*pos = retry_count;
329 	pos++;
330 
331 	if (info->status.rates[0].idx < 0)
332 		return;
333 
334 	/* IEEE80211_RADIOTAP_MCS
335 	 * IEEE80211_RADIOTAP_VHT */
336 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
337 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
338 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
339 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
340 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
341 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
342 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
343 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
344 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
345 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
346 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
347 		pos[2] = info->status.rates[0].idx;
348 		pos += 3;
349 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
350 		u16 known = local->hw.radiotap_vht_details &
351 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
352 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
353 
354 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
355 
356 		/* required alignment from rthdr */
357 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
358 
359 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
360 		put_unaligned_le16(known, pos);
361 		pos += 2;
362 
363 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
364 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
365 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
366 		pos++;
367 
368 		/* u8 bandwidth */
369 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
370 			*pos = 1;
371 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
372 			*pos = 4;
373 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
374 			*pos = 11;
375 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
376 			*pos = 0;
377 		pos++;
378 
379 		/* u8 mcs_nss[4] */
380 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
381 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
382 		pos += 4;
383 
384 		/* u8 coding */
385 		pos++;
386 		/* u8 group_id */
387 		pos++;
388 		/* u16 partial_aid */
389 		pos += 2;
390 	}
391 }
392 
393 /*
394  * Handles the tx for TDLS teardown frames.
395  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
396  */
397 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
398 					struct ieee80211_sub_if_data *sdata,
399 					struct sk_buff *skb, u32 flags)
400 {
401 	struct sk_buff *teardown_skb;
402 	struct sk_buff *orig_teardown_skb;
403 	bool is_teardown = false;
404 
405 	/* Get the teardown data we need and free the lock */
406 	spin_lock(&sdata->u.mgd.teardown_lock);
407 	teardown_skb = sdata->u.mgd.teardown_skb;
408 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
409 	if ((skb == orig_teardown_skb) && teardown_skb) {
410 		sdata->u.mgd.teardown_skb = NULL;
411 		sdata->u.mgd.orig_teardown_skb = NULL;
412 		is_teardown = true;
413 	}
414 	spin_unlock(&sdata->u.mgd.teardown_lock);
415 
416 	if (is_teardown) {
417 		/* This mechanism relies on being able to get ACKs */
418 		WARN_ON(!(local->hw.flags &
419 			  IEEE80211_HW_REPORTS_TX_ACK_STATUS));
420 
421 		/* Check if peer has ACKed */
422 		if (flags & IEEE80211_TX_STAT_ACK) {
423 			dev_kfree_skb_any(teardown_skb);
424 		} else {
425 			tdls_dbg(sdata,
426 				 "TDLS Resending teardown through AP\n");
427 
428 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
429 		}
430 	}
431 }
432 
433 static void ieee80211_report_used_skb(struct ieee80211_local *local,
434 				      struct sk_buff *skb, bool dropped)
435 {
436 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
437 	struct ieee80211_hdr *hdr = (void *)skb->data;
438 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
439 
440 	if (dropped)
441 		acked = false;
442 
443 	if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
444 			   IEEE80211_TX_INTFL_MLME_CONN_TX)) {
445 		struct ieee80211_sub_if_data *sdata = NULL;
446 		struct ieee80211_sub_if_data *iter_sdata;
447 		u64 cookie = (unsigned long)skb;
448 
449 		rcu_read_lock();
450 
451 		if (skb->dev) {
452 			list_for_each_entry_rcu(iter_sdata, &local->interfaces,
453 						list) {
454 				if (!iter_sdata->dev)
455 					continue;
456 
457 				if (skb->dev == iter_sdata->dev) {
458 					sdata = iter_sdata;
459 					break;
460 				}
461 			}
462 		} else {
463 			sdata = rcu_dereference(local->p2p_sdata);
464 		}
465 
466 		if (!sdata) {
467 			skb->dev = NULL;
468 		} else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
469 			unsigned int hdr_size =
470 				ieee80211_hdrlen(hdr->frame_control);
471 
472 			/* Check to see if packet is a TDLS teardown packet */
473 			if (ieee80211_is_data(hdr->frame_control) &&
474 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
475 			     WLAN_TDLS_TEARDOWN))
476 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
477 							    info->flags);
478 			else
479 				ieee80211_mgd_conn_tx_status(sdata,
480 							     hdr->frame_control,
481 							     acked);
482 		} else if (ieee80211_is_nullfunc(hdr->frame_control) ||
483 			   ieee80211_is_qos_nullfunc(hdr->frame_control)) {
484 			cfg80211_probe_status(sdata->dev, hdr->addr1,
485 					      cookie, acked, GFP_ATOMIC);
486 		} else {
487 			cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data,
488 						skb->len, acked, GFP_ATOMIC);
489 		}
490 
491 		rcu_read_unlock();
492 	}
493 
494 	if (unlikely(info->ack_frame_id)) {
495 		struct sk_buff *ack_skb;
496 		unsigned long flags;
497 
498 		spin_lock_irqsave(&local->ack_status_lock, flags);
499 		ack_skb = idr_find(&local->ack_status_frames,
500 				   info->ack_frame_id);
501 		if (ack_skb)
502 			idr_remove(&local->ack_status_frames,
503 				   info->ack_frame_id);
504 		spin_unlock_irqrestore(&local->ack_status_lock, flags);
505 
506 		if (ack_skb) {
507 			if (!dropped) {
508 				/* consumes ack_skb */
509 				skb_complete_wifi_ack(ack_skb, acked);
510 			} else {
511 				dev_kfree_skb_any(ack_skb);
512 			}
513 		}
514 	}
515 }
516 
517 /*
518  * Measure Tx frame completion and removal time for Tx latency statistics
519  * calculation. A single Tx frame latency should be measured from when it
520  * is entering the Kernel until we receive Tx complete confirmation indication
521  * and remove the skb.
522  */
523 static void ieee80211_tx_latency_end_msrmnt(struct ieee80211_local *local,
524 					    struct sk_buff *skb,
525 					    struct sta_info *sta,
526 					    struct ieee80211_hdr *hdr)
527 {
528 	u32 msrmnt;
529 	u16 tid;
530 	u8 *qc;
531 	int i, bin_range_count;
532 	u32 *bin_ranges;
533 	__le16 fc;
534 	struct ieee80211_tx_latency_stat *tx_lat;
535 	struct ieee80211_tx_latency_bin_ranges *tx_latency;
536 	ktime_t skb_arv = skb->tstamp;
537 
538 	tx_latency = rcu_dereference(local->tx_latency);
539 
540 	/* assert Tx latency stats are enabled & frame arrived when enabled */
541 	if (!tx_latency || !ktime_to_ns(skb_arv))
542 		return;
543 
544 	fc = hdr->frame_control;
545 
546 	if (!ieee80211_is_data(fc)) /* make sure it is a data frame */
547 		return;
548 
549 	/* get frame tid */
550 	if (ieee80211_is_data_qos(hdr->frame_control)) {
551 		qc = ieee80211_get_qos_ctl(hdr);
552 		tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
553 	} else {
554 		tid = 0;
555 	}
556 
557 	tx_lat = &sta->tx_lat[tid];
558 
559 	/* Calculate the latency */
560 	msrmnt = ktime_to_ms(ktime_sub(ktime_get(), skb_arv));
561 
562 	if (tx_lat->max < msrmnt) /* update stats */
563 		tx_lat->max = msrmnt;
564 	tx_lat->counter++;
565 	tx_lat->sum += msrmnt;
566 
567 	if (!tx_lat->bins) /* bins not activated */
568 		return;
569 
570 	/* count how many Tx frames transmitted with the appropriate latency */
571 	bin_range_count = tx_latency->n_ranges;
572 	bin_ranges = tx_latency->ranges;
573 
574 	for (i = 0; i < bin_range_count; i++) {
575 		if (msrmnt <= bin_ranges[i]) {
576 			tx_lat->bins[i]++;
577 			break;
578 		}
579 	}
580 	if (i == bin_range_count) /* msrmnt is bigger than the biggest range */
581 		tx_lat->bins[i]++;
582 }
583 
584 /*
585  * Use a static threshold for now, best value to be determined
586  * by testing ...
587  * Should it depend on:
588  *  - on # of retransmissions
589  *  - current throughput (higher value for higher tpt)?
590  */
591 #define STA_LOST_PKT_THRESHOLD	50
592 #define STA_LOST_TDLS_PKT_THRESHOLD	10
593 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
594 
595 static void ieee80211_lost_packet(struct sta_info *sta,
596 				  struct ieee80211_tx_info *info)
597 {
598 	/* This packet was aggregated but doesn't carry status info */
599 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
600 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
601 		return;
602 
603 	sta->lost_packets++;
604 	if (!sta->sta.tdls && sta->lost_packets < STA_LOST_PKT_THRESHOLD)
605 		return;
606 
607 	/*
608 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
609 	 * of the last packets were lost, and that no ACK was received in the
610 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
611 	 * mechanism.
612 	 */
613 	if (sta->sta.tdls &&
614 	    (sta->lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
615 	     time_before(jiffies,
616 			 sta->last_tdls_pkt_time + STA_LOST_TDLS_PKT_TIME)))
617 		return;
618 
619 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
620 				    sta->lost_packets, GFP_ATOMIC);
621 	sta->lost_packets = 0;
622 }
623 
624 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
625 				  struct ieee80211_tx_info *info,
626 				  int *retry_count)
627 {
628 	int rates_idx = -1;
629 	int count = -1;
630 	int i;
631 
632 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
633 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
634 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
635 			/* just the first aggr frame carry status info */
636 			info->status.rates[i].idx = -1;
637 			info->status.rates[i].count = 0;
638 			break;
639 		} else if (info->status.rates[i].idx < 0) {
640 			break;
641 		} else if (i >= hw->max_report_rates) {
642 			/* the HW cannot have attempted that rate */
643 			info->status.rates[i].idx = -1;
644 			info->status.rates[i].count = 0;
645 			break;
646 		}
647 
648 		count += info->status.rates[i].count;
649 	}
650 	rates_idx = i - 1;
651 
652 	if (count < 0)
653 		count = 0;
654 
655 	*retry_count = count;
656 	return rates_idx;
657 }
658 
659 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
660 			       struct ieee80211_sta *pubsta,
661 			       struct ieee80211_tx_info *info)
662 {
663 	struct ieee80211_local *local = hw_to_local(hw);
664 	struct ieee80211_supported_band *sband;
665 	int retry_count;
666 	int rates_idx;
667 	bool acked;
668 
669 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
670 
671 	sband = hw->wiphy->bands[info->band];
672 
673 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
674 	if (pubsta) {
675 		struct sta_info *sta;
676 
677 		sta = container_of(pubsta, struct sta_info, sta);
678 
679 		if (!acked)
680 			sta->tx_retry_failed++;
681 		sta->tx_retry_count += retry_count;
682 
683 		if (acked) {
684 			sta->last_rx = jiffies;
685 
686 			if (sta->lost_packets)
687 				sta->lost_packets = 0;
688 
689 			/* Track when last TDLS packet was ACKed */
690 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
691 				sta->last_tdls_pkt_time = jiffies;
692 		} else {
693 			ieee80211_lost_packet(sta, info);
694 		}
695 
696 		rate_control_tx_status_noskb(local, sband, sta, info);
697 	}
698 
699 	if (acked) {
700 		    local->dot11TransmittedFrameCount++;
701 		    if (!pubsta)
702 			    local->dot11MulticastTransmittedFrameCount++;
703 		    if (retry_count > 0)
704 			    local->dot11RetryCount++;
705 		    if (retry_count > 1)
706 			    local->dot11MultipleRetryCount++;
707 	} else {
708 		local->dot11FailedCount++;
709 	}
710 }
711 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
712 
713 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
714 {
715 	struct sk_buff *skb2;
716 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
717 	struct ieee80211_local *local = hw_to_local(hw);
718 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
719 	__le16 fc;
720 	struct ieee80211_supported_band *sband;
721 	struct ieee80211_sub_if_data *sdata;
722 	struct net_device *prev_dev = NULL;
723 	struct sta_info *sta, *tmp;
724 	int retry_count;
725 	int rates_idx;
726 	bool send_to_cooked;
727 	bool acked;
728 	struct ieee80211_bar *bar;
729 	int rtap_len;
730 	int shift = 0;
731 
732 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
733 
734 	rcu_read_lock();
735 
736 	sband = local->hw.wiphy->bands[info->band];
737 	fc = hdr->frame_control;
738 
739 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
740 		/* skip wrong virtual interface */
741 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
742 			continue;
743 
744 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
745 
746 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
747 			clear_sta_flag(sta, WLAN_STA_SP);
748 
749 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
750 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
751 			/*
752 			 * The STA is in power save mode, so assume
753 			 * that this TX packet failed because of that.
754 			 */
755 			ieee80211_handle_filtered_frame(local, sta, skb);
756 			rcu_read_unlock();
757 			return;
758 		}
759 
760 		/* mesh Peer Service Period support */
761 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
762 		    ieee80211_is_data_qos(fc))
763 			ieee80211_mpsp_trigger_process(
764 					ieee80211_get_qos_ctl(hdr),
765 					sta, true, acked);
766 
767 		if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
768 		    (ieee80211_is_data(hdr->frame_control)) &&
769 		    (rates_idx != -1))
770 			sta->last_tx_rate = info->status.rates[rates_idx];
771 
772 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
773 		    (ieee80211_is_data_qos(fc))) {
774 			u16 tid, ssn;
775 			u8 *qc;
776 
777 			qc = ieee80211_get_qos_ctl(hdr);
778 			tid = qc[0] & 0xf;
779 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
780 						& IEEE80211_SCTL_SEQ);
781 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
782 					   tid, ssn);
783 		}
784 
785 		if (!acked && ieee80211_is_back_req(fc)) {
786 			u16 tid, control;
787 
788 			/*
789 			 * BAR failed, store the last SSN and retry sending
790 			 * the BAR when the next unicast transmission on the
791 			 * same TID succeeds.
792 			 */
793 			bar = (struct ieee80211_bar *) skb->data;
794 			control = le16_to_cpu(bar->control);
795 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
796 				u16 ssn = le16_to_cpu(bar->start_seq_num);
797 
798 				tid = (control &
799 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
800 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
801 
802 				ieee80211_set_bar_pending(sta, tid, ssn);
803 			}
804 		}
805 
806 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
807 			ieee80211_handle_filtered_frame(local, sta, skb);
808 			rcu_read_unlock();
809 			return;
810 		} else {
811 			if (!acked)
812 				sta->tx_retry_failed++;
813 			sta->tx_retry_count += retry_count;
814 		}
815 
816 		rate_control_tx_status(local, sband, sta, skb);
817 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
818 			ieee80211s_update_metric(local, sta, skb);
819 
820 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
821 			ieee80211_frame_acked(sta, skb);
822 
823 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
824 		    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
825 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
826 						acked, info->status.tx_time);
827 
828 		if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
829 			if (info->flags & IEEE80211_TX_STAT_ACK) {
830 				if (sta->lost_packets)
831 					sta->lost_packets = 0;
832 
833 				/* Track when last TDLS packet was ACKed */
834 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
835 					sta->last_tdls_pkt_time = jiffies;
836 			} else {
837 				ieee80211_lost_packet(sta, info);
838 			}
839 		}
840 
841 		if (acked)
842 			sta->last_ack_signal = info->status.ack_signal;
843 
844 		/*
845 		 * Measure frame removal for tx latency
846 		 * statistics calculation
847 		 */
848 		ieee80211_tx_latency_end_msrmnt(local, skb, sta, hdr);
849 	}
850 
851 	rcu_read_unlock();
852 
853 	ieee80211_led_tx(local);
854 
855 	/* SNMP counters
856 	 * Fragments are passed to low-level drivers as separate skbs, so these
857 	 * are actually fragments, not frames. Update frame counters only for
858 	 * the first fragment of the frame. */
859 	if (info->flags & IEEE80211_TX_STAT_ACK) {
860 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
861 			local->dot11TransmittedFrameCount++;
862 			if (is_multicast_ether_addr(hdr->addr1))
863 				local->dot11MulticastTransmittedFrameCount++;
864 			if (retry_count > 0)
865 				local->dot11RetryCount++;
866 			if (retry_count > 1)
867 				local->dot11MultipleRetryCount++;
868 		}
869 
870 		/* This counter shall be incremented for an acknowledged MPDU
871 		 * with an individual address in the address 1 field or an MPDU
872 		 * with a multicast address in the address 1 field of type Data
873 		 * or Management. */
874 		if (!is_multicast_ether_addr(hdr->addr1) ||
875 		    ieee80211_is_data(fc) ||
876 		    ieee80211_is_mgmt(fc))
877 			local->dot11TransmittedFragmentCount++;
878 	} else {
879 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
880 			local->dot11FailedCount++;
881 	}
882 
883 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
884 	    (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
885 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
886 	    local->ps_sdata && !(local->scanning)) {
887 		if (info->flags & IEEE80211_TX_STAT_ACK) {
888 			local->ps_sdata->u.mgd.flags |=
889 					IEEE80211_STA_NULLFUNC_ACKED;
890 		} else
891 			mod_timer(&local->dynamic_ps_timer, jiffies +
892 					msecs_to_jiffies(10));
893 	}
894 
895 	ieee80211_report_used_skb(local, skb, false);
896 
897 	/* this was a transmitted frame, but now we want to reuse it */
898 	skb_orphan(skb);
899 
900 	/* Need to make a copy before skb->cb gets cleared */
901 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
902 			 !(ieee80211_is_data(fc));
903 
904 	/*
905 	 * This is a bit racy but we can avoid a lot of work
906 	 * with this test...
907 	 */
908 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
909 		dev_kfree_skb(skb);
910 		return;
911 	}
912 
913 	/* send frame to monitor interfaces now */
914 	rtap_len = ieee80211_tx_radiotap_len(info);
915 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
916 		pr_err("ieee80211_tx_status: headroom too small\n");
917 		dev_kfree_skb(skb);
918 		return;
919 	}
920 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
921 					 rtap_len, shift);
922 
923 	/* XXX: is this sufficient for BPF? */
924 	skb_set_mac_header(skb, 0);
925 	skb->ip_summed = CHECKSUM_UNNECESSARY;
926 	skb->pkt_type = PACKET_OTHERHOST;
927 	skb->protocol = htons(ETH_P_802_2);
928 	memset(skb->cb, 0, sizeof(skb->cb));
929 
930 	rcu_read_lock();
931 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
932 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
933 			if (!ieee80211_sdata_running(sdata))
934 				continue;
935 
936 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
937 			    !send_to_cooked)
938 				continue;
939 
940 			if (prev_dev) {
941 				skb2 = skb_clone(skb, GFP_ATOMIC);
942 				if (skb2) {
943 					skb2->dev = prev_dev;
944 					netif_rx(skb2);
945 				}
946 			}
947 
948 			prev_dev = sdata->dev;
949 		}
950 	}
951 	if (prev_dev) {
952 		skb->dev = prev_dev;
953 		netif_rx(skb);
954 		skb = NULL;
955 	}
956 	rcu_read_unlock();
957 	dev_kfree_skb(skb);
958 }
959 EXPORT_SYMBOL(ieee80211_tx_status);
960 
961 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
962 {
963 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
964 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
965 				    num_packets, GFP_ATOMIC);
966 }
967 EXPORT_SYMBOL(ieee80211_report_low_ack);
968 
969 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
970 {
971 	struct ieee80211_local *local = hw_to_local(hw);
972 
973 	ieee80211_report_used_skb(local, skb, true);
974 	dev_kfree_skb_any(skb);
975 }
976 EXPORT_SYMBOL(ieee80211_free_txskb);
977 
978 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
979 			      struct sk_buff_head *skbs)
980 {
981 	struct sk_buff *skb;
982 
983 	while ((skb = __skb_dequeue(skbs)))
984 		ieee80211_free_txskb(hw, skb);
985 }
986