xref: /openbmc/linux/net/mac80211/status.c (revision b9b77222)
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 <net/mac80211.h>
16 #include <asm/unaligned.h>
17 #include "ieee80211_i.h"
18 #include "rate.h"
19 #include "mesh.h"
20 #include "led.h"
21 #include "wme.h"
22 
23 
24 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
25 				 struct sk_buff *skb)
26 {
27 	struct ieee80211_local *local = hw_to_local(hw);
28 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
29 	int tmp;
30 
31 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
32 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
33 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
34 	tmp = skb_queue_len(&local->skb_queue) +
35 		skb_queue_len(&local->skb_queue_unreliable);
36 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
37 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
38 		ieee80211_free_txskb(hw, skb);
39 		tmp--;
40 		I802_DEBUG_INC(local->tx_status_drop);
41 	}
42 	tasklet_schedule(&local->tasklet);
43 }
44 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
45 
46 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
47 					    struct sta_info *sta,
48 					    struct sk_buff *skb)
49 {
50 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
51 	struct ieee80211_hdr *hdr = (void *)skb->data;
52 	int ac;
53 
54 	if (info->flags & (IEEE80211_TX_CTL_NO_PS_BUFFER |
55 			   IEEE80211_TX_CTL_AMPDU)) {
56 		ieee80211_free_txskb(&local->hw, skb);
57 		return;
58 	}
59 
60 	/*
61 	 * This skb 'survived' a round-trip through the driver, and
62 	 * hopefully the driver didn't mangle it too badly. However,
63 	 * we can definitely not rely on the control information
64 	 * being correct. Clear it so we don't get junk there, and
65 	 * indicate that it needs new processing, but must not be
66 	 * modified/encrypted again.
67 	 */
68 	memset(&info->control, 0, sizeof(info->control));
69 
70 	info->control.jiffies = jiffies;
71 	info->control.vif = &sta->sdata->vif;
72 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
73 		       IEEE80211_TX_INTFL_RETRANSMISSION;
74 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
75 
76 	sta->status_stats.filtered++;
77 
78 	/*
79 	 * Clear more-data bit on filtered frames, it might be set
80 	 * but later frames might time out so it might have to be
81 	 * clear again ... It's all rather unlikely (this frame
82 	 * should time out first, right?) but let's not confuse
83 	 * peers unnecessarily.
84 	 */
85 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
86 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
87 
88 	if (ieee80211_is_data_qos(hdr->frame_control)) {
89 		u8 *p = ieee80211_get_qos_ctl(hdr);
90 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
91 
92 		/*
93 		 * Clear EOSP if set, this could happen e.g.
94 		 * if an absence period (us being a P2P GO)
95 		 * shortens the SP.
96 		 */
97 		if (*p & IEEE80211_QOS_CTL_EOSP)
98 			*p &= ~IEEE80211_QOS_CTL_EOSP;
99 		ac = ieee80211_ac_from_tid(tid);
100 	} else {
101 		ac = IEEE80211_AC_BE;
102 	}
103 
104 	/*
105 	 * Clear the TX filter mask for this STA when sending the next
106 	 * packet. If the STA went to power save mode, this will happen
107 	 * when it wakes up for the next time.
108 	 */
109 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
110 	ieee80211_clear_fast_xmit(sta);
111 
112 	/*
113 	 * This code races in the following way:
114 	 *
115 	 *  (1) STA sends frame indicating it will go to sleep and does so
116 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
117 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
118 	 *  (4) we get TX status before having processed the frame and
119 	 *	knowing that the STA has gone to sleep.
120 	 *
121 	 * This is actually quite unlikely even when both those events are
122 	 * processed from interrupts coming in quickly after one another or
123 	 * even at the same time because we queue both TX status events and
124 	 * RX frames to be processed by a tasklet and process them in the
125 	 * same order that they were received or TX status last. Hence, there
126 	 * is no race as long as the frame RX is processed before the next TX
127 	 * status, which drivers can ensure, see below.
128 	 *
129 	 * Note that this can only happen if the hardware or firmware can
130 	 * actually add STAs to the filter list, if this is done by the
131 	 * driver in response to set_tim() (which will only reduce the race
132 	 * this whole filtering tries to solve, not completely solve it)
133 	 * this situation cannot happen.
134 	 *
135 	 * To completely solve this race drivers need to make sure that they
136 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
137 	 *	functions and
138 	 *  (b) always process RX events before TX status events if ordering
139 	 *      can be unknown, for example with different interrupt status
140 	 *	bits.
141 	 *  (c) if PS mode transitions are manual (i.e. the flag
142 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
143 	 *      changes before calling TX status events if ordering can be
144 	 *	unknown.
145 	 */
146 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
147 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
148 		skb_queue_tail(&sta->tx_filtered[ac], skb);
149 		sta_info_recalc_tim(sta);
150 
151 		if (!timer_pending(&local->sta_cleanup))
152 			mod_timer(&local->sta_cleanup,
153 				  round_jiffies(jiffies +
154 						STA_INFO_CLEANUP_INTERVAL));
155 		return;
156 	}
157 
158 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
159 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
160 		/* Software retry the packet once */
161 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
162 		ieee80211_add_pending_skb(local, skb);
163 		return;
164 	}
165 
166 	ps_dbg_ratelimited(sta->sdata,
167 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
168 			   skb_queue_len(&sta->tx_filtered[ac]),
169 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
170 	ieee80211_free_txskb(&local->hw, skb);
171 }
172 
173 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
174 {
175 	struct tid_ampdu_tx *tid_tx;
176 
177 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
178 	if (!tid_tx || !tid_tx->bar_pending)
179 		return;
180 
181 	tid_tx->bar_pending = false;
182 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
183 }
184 
185 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
186 {
187 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
188 	struct ieee80211_local *local = sta->local;
189 	struct ieee80211_sub_if_data *sdata = sta->sdata;
190 	struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
191 
192 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
193 		sta->status_stats.last_ack = jiffies;
194 		if (txinfo->status.is_valid_ack_signal) {
195 			sta->status_stats.last_ack_signal =
196 					 (s8)txinfo->status.ack_signal;
197 			sta->status_stats.ack_signal_filled = true;
198 			ewma_avg_signal_add(&sta->status_stats.avg_ack_signal,
199 					    -txinfo->status.ack_signal);
200 		}
201 	}
202 
203 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
204 		struct ieee80211_hdr *hdr = (void *) skb->data;
205 		u8 *qc = ieee80211_get_qos_ctl(hdr);
206 		u16 tid = qc[0] & 0xf;
207 
208 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
209 	}
210 
211 	if (ieee80211_is_action(mgmt->frame_control) &&
212 	    !ieee80211_has_protected(mgmt->frame_control) &&
213 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
214 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
215 	    ieee80211_sdata_running(sdata)) {
216 		enum ieee80211_smps_mode smps_mode;
217 
218 		switch (mgmt->u.action.u.ht_smps.smps_control) {
219 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
220 			smps_mode = IEEE80211_SMPS_DYNAMIC;
221 			break;
222 		case WLAN_HT_SMPS_CONTROL_STATIC:
223 			smps_mode = IEEE80211_SMPS_STATIC;
224 			break;
225 		case WLAN_HT_SMPS_CONTROL_DISABLED:
226 		default: /* shouldn't happen since we don't send that */
227 			smps_mode = IEEE80211_SMPS_OFF;
228 			break;
229 		}
230 
231 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
232 			/*
233 			 * This update looks racy, but isn't -- if we come
234 			 * here we've definitely got a station that we're
235 			 * talking to, and on a managed interface that can
236 			 * only be the AP. And the only other place updating
237 			 * this variable in managed mode is before association.
238 			 */
239 			sdata->smps_mode = smps_mode;
240 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
241 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
242 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
243 			sta->known_smps_mode = smps_mode;
244 		}
245 	}
246 }
247 
248 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
249 {
250 	struct tid_ampdu_tx *tid_tx;
251 
252 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
253 	if (!tid_tx)
254 		return;
255 
256 	tid_tx->failed_bar_ssn = ssn;
257 	tid_tx->bar_pending = true;
258 }
259 
260 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
261 {
262 	int len = sizeof(struct ieee80211_radiotap_header);
263 
264 	/* IEEE80211_RADIOTAP_RATE rate */
265 	if (info->status.rates[0].idx >= 0 &&
266 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
267 					     IEEE80211_TX_RC_VHT_MCS)))
268 		len += 2;
269 
270 	/* IEEE80211_RADIOTAP_TX_FLAGS */
271 	len += 2;
272 
273 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
274 	len += 1;
275 
276 	/* IEEE80211_RADIOTAP_MCS
277 	 * IEEE80211_RADIOTAP_VHT */
278 	if (info->status.rates[0].idx >= 0) {
279 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
280 			len += 3;
281 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
282 			len = ALIGN(len, 2) + 12;
283 	}
284 
285 	return len;
286 }
287 
288 static void
289 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
290 				 struct ieee80211_supported_band *sband,
291 				 struct sk_buff *skb, int retry_count,
292 				 int rtap_len, int shift)
293 {
294 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
295 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
296 	struct ieee80211_radiotap_header *rthdr;
297 	unsigned char *pos;
298 	u16 txflags;
299 
300 	rthdr = skb_push(skb, rtap_len);
301 
302 	memset(rthdr, 0, rtap_len);
303 	rthdr->it_len = cpu_to_le16(rtap_len);
304 	rthdr->it_present =
305 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
306 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
307 	pos = (unsigned char *)(rthdr + 1);
308 
309 	/*
310 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
311 	 *	extensions proposal contains, we can actually report
312 	 *	the whole set of tries we did.
313 	 */
314 
315 	/* IEEE80211_RADIOTAP_RATE */
316 	if (info->status.rates[0].idx >= 0 &&
317 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
318 					     IEEE80211_TX_RC_VHT_MCS))) {
319 		u16 rate;
320 
321 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
322 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
323 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
324 		/* padding for tx flags */
325 		pos += 2;
326 	}
327 
328 	/* IEEE80211_RADIOTAP_TX_FLAGS */
329 	txflags = 0;
330 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
331 	    !is_multicast_ether_addr(hdr->addr1))
332 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
333 
334 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
335 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
336 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
337 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
338 
339 	put_unaligned_le16(txflags, pos);
340 	pos += 2;
341 
342 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
343 	/* for now report the total retry_count */
344 	*pos = retry_count;
345 	pos++;
346 
347 	if (info->status.rates[0].idx < 0)
348 		return;
349 
350 	/* IEEE80211_RADIOTAP_MCS
351 	 * IEEE80211_RADIOTAP_VHT */
352 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
353 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
354 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
355 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
356 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
357 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
358 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
359 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
360 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
361 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
362 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
363 		pos[2] = info->status.rates[0].idx;
364 		pos += 3;
365 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
366 		u16 known = local->hw.radiotap_vht_details &
367 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
368 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
369 
370 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
371 
372 		/* required alignment from rthdr */
373 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
374 
375 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
376 		put_unaligned_le16(known, pos);
377 		pos += 2;
378 
379 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
380 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
381 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
382 		pos++;
383 
384 		/* u8 bandwidth */
385 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
386 			*pos = 1;
387 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
388 			*pos = 4;
389 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
390 			*pos = 11;
391 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
392 			*pos = 0;
393 		pos++;
394 
395 		/* u8 mcs_nss[4] */
396 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
397 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
398 		pos += 4;
399 
400 		/* u8 coding */
401 		pos++;
402 		/* u8 group_id */
403 		pos++;
404 		/* u16 partial_aid */
405 		pos += 2;
406 	}
407 }
408 
409 /*
410  * Handles the tx for TDLS teardown frames.
411  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
412  */
413 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
414 					struct ieee80211_sub_if_data *sdata,
415 					struct sk_buff *skb, u32 flags)
416 {
417 	struct sk_buff *teardown_skb;
418 	struct sk_buff *orig_teardown_skb;
419 	bool is_teardown = false;
420 
421 	/* Get the teardown data we need and free the lock */
422 	spin_lock(&sdata->u.mgd.teardown_lock);
423 	teardown_skb = sdata->u.mgd.teardown_skb;
424 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
425 	if ((skb == orig_teardown_skb) && teardown_skb) {
426 		sdata->u.mgd.teardown_skb = NULL;
427 		sdata->u.mgd.orig_teardown_skb = NULL;
428 		is_teardown = true;
429 	}
430 	spin_unlock(&sdata->u.mgd.teardown_lock);
431 
432 	if (is_teardown) {
433 		/* This mechanism relies on being able to get ACKs */
434 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
435 
436 		/* Check if peer has ACKed */
437 		if (flags & IEEE80211_TX_STAT_ACK) {
438 			dev_kfree_skb_any(teardown_skb);
439 		} else {
440 			tdls_dbg(sdata,
441 				 "TDLS Resending teardown through AP\n");
442 
443 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
444 		}
445 	}
446 }
447 
448 static struct ieee80211_sub_if_data *
449 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
450 {
451 	struct ieee80211_sub_if_data *sdata;
452 
453 	if (skb->dev) {
454 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
455 			if (!sdata->dev)
456 				continue;
457 
458 			if (skb->dev == sdata->dev)
459 				return sdata;
460 		}
461 
462 		return NULL;
463 	}
464 
465 	return rcu_dereference(local->p2p_sdata);
466 }
467 
468 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
469 				     struct ieee80211_tx_info *info,
470 				     bool acked, bool dropped)
471 {
472 	struct sk_buff *skb;
473 	unsigned long flags;
474 
475 	spin_lock_irqsave(&local->ack_status_lock, flags);
476 	skb = idr_remove(&local->ack_status_frames, info->ack_frame_id);
477 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
478 
479 	if (!skb)
480 		return;
481 
482 	if (dropped) {
483 		dev_kfree_skb_any(skb);
484 		return;
485 	}
486 
487 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
488 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
489 		struct ieee80211_sub_if_data *sdata;
490 		struct ieee80211_hdr *hdr = (void *)skb->data;
491 
492 		rcu_read_lock();
493 		sdata = ieee80211_sdata_from_skb(local, skb);
494 		if (sdata) {
495 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
496 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
497 				cfg80211_probe_status(sdata->dev, hdr->addr1,
498 						      cookie, acked,
499 						      info->status.ack_signal,
500 						      info->status.is_valid_ack_signal,
501 						      GFP_ATOMIC);
502 			else
503 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
504 							skb->data, skb->len,
505 							acked, GFP_ATOMIC);
506 		}
507 		rcu_read_unlock();
508 
509 		dev_kfree_skb_any(skb);
510 	} else {
511 		/* consumes skb */
512 		skb_complete_wifi_ack(skb, acked);
513 	}
514 }
515 
516 static void ieee80211_report_used_skb(struct ieee80211_local *local,
517 				      struct sk_buff *skb, bool dropped)
518 {
519 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
520 	struct ieee80211_hdr *hdr = (void *)skb->data;
521 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
522 
523 	if (dropped)
524 		acked = false;
525 
526 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
527 		struct ieee80211_sub_if_data *sdata;
528 
529 		rcu_read_lock();
530 
531 		sdata = ieee80211_sdata_from_skb(local, skb);
532 
533 		if (!sdata) {
534 			skb->dev = NULL;
535 		} else {
536 			unsigned int hdr_size =
537 				ieee80211_hdrlen(hdr->frame_control);
538 
539 			/* Check to see if packet is a TDLS teardown packet */
540 			if (ieee80211_is_data(hdr->frame_control) &&
541 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
542 			     WLAN_TDLS_TEARDOWN))
543 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
544 							    info->flags);
545 			else
546 				ieee80211_mgd_conn_tx_status(sdata,
547 							     hdr->frame_control,
548 							     acked);
549 		}
550 
551 		rcu_read_unlock();
552 	} else if (info->ack_frame_id) {
553 		ieee80211_report_ack_skb(local, info, acked, dropped);
554 	}
555 
556 	if (!dropped && skb->destructor) {
557 		skb->wifi_acked_valid = 1;
558 		skb->wifi_acked = acked;
559 	}
560 
561 	ieee80211_led_tx(local);
562 }
563 
564 /*
565  * Use a static threshold for now, best value to be determined
566  * by testing ...
567  * Should it depend on:
568  *  - on # of retransmissions
569  *  - current throughput (higher value for higher tpt)?
570  */
571 #define STA_LOST_PKT_THRESHOLD	50
572 #define STA_LOST_TDLS_PKT_THRESHOLD	10
573 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
574 
575 static void ieee80211_lost_packet(struct sta_info *sta,
576 				  struct ieee80211_tx_info *info)
577 {
578 	/* If driver relies on its own algorithm for station kickout, skip
579 	 * mac80211 packet loss mechanism.
580 	 */
581 	if (ieee80211_hw_check(&sta->local->hw, REPORTS_LOW_ACK))
582 		return;
583 
584 	/* This packet was aggregated but doesn't carry status info */
585 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
586 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
587 		return;
588 
589 	sta->status_stats.lost_packets++;
590 	if (!sta->sta.tdls &&
591 	    sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD)
592 		return;
593 
594 	/*
595 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
596 	 * of the last packets were lost, and that no ACK was received in the
597 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
598 	 * mechanism.
599 	 */
600 	if (sta->sta.tdls &&
601 	    (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
602 	     time_before(jiffies,
603 			 sta->status_stats.last_tdls_pkt_time +
604 			 STA_LOST_TDLS_PKT_TIME)))
605 		return;
606 
607 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
608 				    sta->status_stats.lost_packets, GFP_ATOMIC);
609 	sta->status_stats.lost_packets = 0;
610 }
611 
612 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
613 				  struct ieee80211_tx_info *info,
614 				  int *retry_count)
615 {
616 	int rates_idx = -1;
617 	int count = -1;
618 	int i;
619 
620 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
621 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
622 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
623 			/* just the first aggr frame carry status info */
624 			info->status.rates[i].idx = -1;
625 			info->status.rates[i].count = 0;
626 			break;
627 		} else if (info->status.rates[i].idx < 0) {
628 			break;
629 		} else if (i >= hw->max_report_rates) {
630 			/* the HW cannot have attempted that rate */
631 			info->status.rates[i].idx = -1;
632 			info->status.rates[i].count = 0;
633 			break;
634 		}
635 
636 		count += info->status.rates[i].count;
637 	}
638 	rates_idx = i - 1;
639 
640 	if (count < 0)
641 		count = 0;
642 
643 	*retry_count = count;
644 	return rates_idx;
645 }
646 
647 void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
648 			  struct ieee80211_supported_band *sband,
649 			  int retry_count, int shift, bool send_to_cooked)
650 {
651 	struct sk_buff *skb2;
652 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
653 	struct ieee80211_sub_if_data *sdata;
654 	struct net_device *prev_dev = NULL;
655 	int rtap_len;
656 
657 	/* send frame to monitor interfaces now */
658 	rtap_len = ieee80211_tx_radiotap_len(info);
659 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
660 		pr_err("ieee80211_tx_status: headroom too small\n");
661 		dev_kfree_skb(skb);
662 		return;
663 	}
664 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
665 					 rtap_len, shift);
666 
667 	/* XXX: is this sufficient for BPF? */
668 	skb_reset_mac_header(skb);
669 	skb->ip_summed = CHECKSUM_UNNECESSARY;
670 	skb->pkt_type = PACKET_OTHERHOST;
671 	skb->protocol = htons(ETH_P_802_2);
672 	memset(skb->cb, 0, sizeof(skb->cb));
673 
674 	rcu_read_lock();
675 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
676 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
677 			if (!ieee80211_sdata_running(sdata))
678 				continue;
679 
680 			if ((sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES) &&
681 			    !send_to_cooked)
682 				continue;
683 
684 			if (prev_dev) {
685 				skb2 = skb_clone(skb, GFP_ATOMIC);
686 				if (skb2) {
687 					skb2->dev = prev_dev;
688 					netif_rx(skb2);
689 				}
690 			}
691 
692 			prev_dev = sdata->dev;
693 		}
694 	}
695 	if (prev_dev) {
696 		skb->dev = prev_dev;
697 		netif_rx(skb);
698 		skb = NULL;
699 	}
700 	rcu_read_unlock();
701 	dev_kfree_skb(skb);
702 }
703 
704 static void __ieee80211_tx_status(struct ieee80211_hw *hw,
705 				  struct ieee80211_tx_status *status)
706 {
707 	struct sk_buff *skb = status->skb;
708 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
709 	struct ieee80211_local *local = hw_to_local(hw);
710 	struct ieee80211_tx_info *info = status->info;
711 	struct sta_info *sta;
712 	__le16 fc;
713 	struct ieee80211_supported_band *sband;
714 	int retry_count;
715 	int rates_idx;
716 	bool send_to_cooked;
717 	bool acked;
718 	struct ieee80211_bar *bar;
719 	int shift = 0;
720 	int tid = IEEE80211_NUM_TIDS;
721 
722 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
723 
724 	sband = local->hw.wiphy->bands[info->band];
725 	fc = hdr->frame_control;
726 
727 	if (status->sta) {
728 		sta = container_of(status->sta, struct sta_info, sta);
729 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
730 
731 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
732 			clear_sta_flag(sta, WLAN_STA_SP);
733 
734 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
735 
736 		/* mesh Peer Service Period support */
737 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
738 		    ieee80211_is_data_qos(fc))
739 			ieee80211_mpsp_trigger_process(
740 				ieee80211_get_qos_ctl(hdr), sta, true, acked);
741 
742 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
743 			/*
744 			 * The STA is in power save mode, so assume
745 			 * that this TX packet failed because of that.
746 			 */
747 			ieee80211_handle_filtered_frame(local, sta, skb);
748 			return;
749 		}
750 
751 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
752 		    (ieee80211_is_data(hdr->frame_control)) &&
753 		    (rates_idx != -1))
754 			sta->tx_stats.last_rate =
755 				info->status.rates[rates_idx];
756 
757 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
758 		    (ieee80211_is_data_qos(fc))) {
759 			u16 ssn;
760 			u8 *qc;
761 
762 			qc = ieee80211_get_qos_ctl(hdr);
763 			tid = qc[0] & 0xf;
764 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
765 						& IEEE80211_SCTL_SEQ);
766 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
767 					   tid, ssn);
768 		} else if (ieee80211_is_data_qos(fc)) {
769 			u8 *qc = ieee80211_get_qos_ctl(hdr);
770 
771 			tid = qc[0] & 0xf;
772 		}
773 
774 		if (!acked && ieee80211_is_back_req(fc)) {
775 			u16 control;
776 
777 			/*
778 			 * BAR failed, store the last SSN and retry sending
779 			 * the BAR when the next unicast transmission on the
780 			 * same TID succeeds.
781 			 */
782 			bar = (struct ieee80211_bar *) skb->data;
783 			control = le16_to_cpu(bar->control);
784 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
785 				u16 ssn = le16_to_cpu(bar->start_seq_num);
786 
787 				tid = (control &
788 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
789 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
790 
791 				ieee80211_set_bar_pending(sta, tid, ssn);
792 			}
793 		}
794 
795 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
796 			ieee80211_handle_filtered_frame(local, sta, skb);
797 			return;
798 		} else {
799 			if (!acked)
800 				sta->status_stats.retry_failed++;
801 			sta->status_stats.retry_count += retry_count;
802 
803 			if (ieee80211_is_data_present(fc)) {
804 				if (!acked)
805 					sta->status_stats.msdu_failed[tid]++;
806 
807 				sta->status_stats.msdu_retries[tid] +=
808 					retry_count;
809 			}
810 		}
811 
812 		rate_control_tx_status(local, sband, status);
813 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
814 			ieee80211s_update_metric(local, sta, skb);
815 
816 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
817 			ieee80211_frame_acked(sta, skb);
818 
819 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
820 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
821 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
822 						acked, info->status.tx_time);
823 
824 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
825 			if (info->flags & IEEE80211_TX_STAT_ACK) {
826 				if (sta->status_stats.lost_packets)
827 					sta->status_stats.lost_packets = 0;
828 
829 				/* Track when last TDLS packet was ACKed */
830 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
831 					sta->status_stats.last_tdls_pkt_time =
832 						jiffies;
833 			} else {
834 				ieee80211_lost_packet(sta, info);
835 			}
836 		}
837 	}
838 
839 	/* SNMP counters
840 	 * Fragments are passed to low-level drivers as separate skbs, so these
841 	 * are actually fragments, not frames. Update frame counters only for
842 	 * the first fragment of the frame. */
843 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
844 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
845 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
846 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
847 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
848 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
849 			if (retry_count > 0)
850 				I802_DEBUG_INC(local->dot11RetryCount);
851 			if (retry_count > 1)
852 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
853 		}
854 
855 		/* This counter shall be incremented for an acknowledged MPDU
856 		 * with an individual address in the address 1 field or an MPDU
857 		 * with a multicast address in the address 1 field of type Data
858 		 * or Management. */
859 		if (!is_multicast_ether_addr(hdr->addr1) ||
860 		    ieee80211_is_data(fc) ||
861 		    ieee80211_is_mgmt(fc))
862 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
863 	} else {
864 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
865 			I802_DEBUG_INC(local->dot11FailedCount);
866 	}
867 
868 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
869 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
870 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
871 	    local->ps_sdata && !(local->scanning)) {
872 		if (info->flags & IEEE80211_TX_STAT_ACK) {
873 			local->ps_sdata->u.mgd.flags |=
874 					IEEE80211_STA_NULLFUNC_ACKED;
875 		} else
876 			mod_timer(&local->dynamic_ps_timer, jiffies +
877 					msecs_to_jiffies(10));
878 	}
879 
880 	ieee80211_report_used_skb(local, skb, false);
881 
882 	/* this was a transmitted frame, but now we want to reuse it */
883 	skb_orphan(skb);
884 
885 	/* Need to make a copy before skb->cb gets cleared */
886 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
887 			 !(ieee80211_is_data(fc));
888 
889 	/*
890 	 * This is a bit racy but we can avoid a lot of work
891 	 * with this test...
892 	 */
893 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
894 		dev_kfree_skb(skb);
895 		return;
896 	}
897 
898 	/* send to monitor interfaces */
899 	ieee80211_tx_monitor(local, skb, sband, retry_count, shift, send_to_cooked);
900 }
901 
902 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
903 {
904 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
905 	struct ieee80211_local *local = hw_to_local(hw);
906 	struct ieee80211_tx_status status = {
907 		.skb = skb,
908 		.info = IEEE80211_SKB_CB(skb),
909 	};
910 	struct rhlist_head *tmp;
911 	struct sta_info *sta;
912 
913 	rcu_read_lock();
914 
915 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
916 		/* skip wrong virtual interface */
917 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
918 			continue;
919 
920 		status.sta = &sta->sta;
921 		break;
922 	}
923 
924 	__ieee80211_tx_status(hw, &status);
925 	rcu_read_unlock();
926 }
927 EXPORT_SYMBOL(ieee80211_tx_status);
928 
929 void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
930 			     struct ieee80211_tx_status *status)
931 {
932 	struct ieee80211_local *local = hw_to_local(hw);
933 	struct ieee80211_tx_info *info = status->info;
934 	struct ieee80211_sta *pubsta = status->sta;
935 	struct ieee80211_supported_band *sband;
936 	int retry_count;
937 	bool acked, noack_success;
938 
939 	if (status->skb)
940 		return __ieee80211_tx_status(hw, status);
941 
942 	if (!status->sta)
943 		return;
944 
945 	ieee80211_tx_get_rates(hw, info, &retry_count);
946 
947 	sband = hw->wiphy->bands[info->band];
948 
949 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
950 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
951 
952 	if (pubsta) {
953 		struct sta_info *sta;
954 
955 		sta = container_of(pubsta, struct sta_info, sta);
956 
957 		if (!acked)
958 			sta->status_stats.retry_failed++;
959 		sta->status_stats.retry_count += retry_count;
960 
961 		if (acked) {
962 			sta->status_stats.last_ack = jiffies;
963 
964 			if (sta->status_stats.lost_packets)
965 				sta->status_stats.lost_packets = 0;
966 
967 			/* Track when last TDLS packet was ACKed */
968 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
969 				sta->status_stats.last_tdls_pkt_time = jiffies;
970 		} else {
971 			ieee80211_lost_packet(sta, info);
972 		}
973 
974 		rate_control_tx_status(local, sband, status);
975 	}
976 
977 	if (acked || noack_success) {
978 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
979 		if (!pubsta)
980 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
981 		if (retry_count > 0)
982 			I802_DEBUG_INC(local->dot11RetryCount);
983 		if (retry_count > 1)
984 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
985 	} else {
986 		I802_DEBUG_INC(local->dot11FailedCount);
987 	}
988 }
989 EXPORT_SYMBOL(ieee80211_tx_status_ext);
990 
991 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
992 {
993 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
994 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
995 				    num_packets, GFP_ATOMIC);
996 }
997 EXPORT_SYMBOL(ieee80211_report_low_ack);
998 
999 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
1000 {
1001 	struct ieee80211_local *local = hw_to_local(hw);
1002 
1003 	ieee80211_report_used_skb(local, skb, true);
1004 	dev_kfree_skb_any(skb);
1005 }
1006 EXPORT_SYMBOL(ieee80211_free_txskb);
1007 
1008 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
1009 			      struct sk_buff_head *skbs)
1010 {
1011 	struct sk_buff *skb;
1012 
1013 	while ((skb = __skb_dequeue(skbs)))
1014 		ieee80211_free_txskb(hw, skb);
1015 }
1016