xref: /linux/net/mac80211/status.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2002-2005, Instant802 Networks, Inc.
4  * Copyright 2005-2006, Devicescape Software, Inc.
5  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
6  * Copyright 2008-2010	Johannes Berg <johannes@sipsolutions.net>
7  * Copyright 2013-2014  Intel Mobile Communications GmbH
8  */
9 
10 #include <linux/export.h>
11 #include <linux/etherdevice.h>
12 #include <net/mac80211.h>
13 #include <asm/unaligned.h>
14 #include "ieee80211_i.h"
15 #include "rate.h"
16 #include "mesh.h"
17 #include "led.h"
18 #include "wme.h"
19 
20 
21 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
22 				 struct sk_buff *skb)
23 {
24 	struct ieee80211_local *local = hw_to_local(hw);
25 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
26 	int tmp;
27 
28 	skb->pkt_type = IEEE80211_TX_STATUS_MSG;
29 	skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
30 		       &local->skb_queue : &local->skb_queue_unreliable, skb);
31 	tmp = skb_queue_len(&local->skb_queue) +
32 		skb_queue_len(&local->skb_queue_unreliable);
33 	while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
34 	       (skb = skb_dequeue(&local->skb_queue_unreliable))) {
35 		ieee80211_free_txskb(hw, skb);
36 		tmp--;
37 		I802_DEBUG_INC(local->tx_status_drop);
38 	}
39 	tasklet_schedule(&local->tasklet);
40 }
41 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
42 
43 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
44 					    struct sta_info *sta,
45 					    struct sk_buff *skb)
46 {
47 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
48 	struct ieee80211_hdr *hdr = (void *)skb->data;
49 	int ac;
50 
51 	if (info->flags & (IEEE80211_TX_CTL_NO_PS_BUFFER |
52 			   IEEE80211_TX_CTL_AMPDU)) {
53 		ieee80211_free_txskb(&local->hw, skb);
54 		return;
55 	}
56 
57 	/*
58 	 * This skb 'survived' a round-trip through the driver, and
59 	 * hopefully the driver didn't mangle it too badly. However,
60 	 * we can definitely not rely on the control information
61 	 * being correct. Clear it so we don't get junk there, and
62 	 * indicate that it needs new processing, but must not be
63 	 * modified/encrypted again.
64 	 */
65 	memset(&info->control, 0, sizeof(info->control));
66 
67 	info->control.jiffies = jiffies;
68 	info->control.vif = &sta->sdata->vif;
69 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
70 		       IEEE80211_TX_INTFL_RETRANSMISSION;
71 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
72 
73 	sta->status_stats.filtered++;
74 
75 	/*
76 	 * Clear more-data bit on filtered frames, it might be set
77 	 * but later frames might time out so it might have to be
78 	 * clear again ... It's all rather unlikely (this frame
79 	 * should time out first, right?) but let's not confuse
80 	 * peers unnecessarily.
81 	 */
82 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
83 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
84 
85 	if (ieee80211_is_data_qos(hdr->frame_control)) {
86 		u8 *p = ieee80211_get_qos_ctl(hdr);
87 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
88 
89 		/*
90 		 * Clear EOSP if set, this could happen e.g.
91 		 * if an absence period (us being a P2P GO)
92 		 * shortens the SP.
93 		 */
94 		if (*p & IEEE80211_QOS_CTL_EOSP)
95 			*p &= ~IEEE80211_QOS_CTL_EOSP;
96 		ac = ieee80211_ac_from_tid(tid);
97 	} else {
98 		ac = IEEE80211_AC_BE;
99 	}
100 
101 	/*
102 	 * Clear the TX filter mask for this STA when sending the next
103 	 * packet. If the STA went to power save mode, this will happen
104 	 * when it wakes up for the next time.
105 	 */
106 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
107 	ieee80211_clear_fast_xmit(sta);
108 
109 	/*
110 	 * This code races in the following way:
111 	 *
112 	 *  (1) STA sends frame indicating it will go to sleep and does so
113 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
114 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
115 	 *  (4) we get TX status before having processed the frame and
116 	 *	knowing that the STA has gone to sleep.
117 	 *
118 	 * This is actually quite unlikely even when both those events are
119 	 * processed from interrupts coming in quickly after one another or
120 	 * even at the same time because we queue both TX status events and
121 	 * RX frames to be processed by a tasklet and process them in the
122 	 * same order that they were received or TX status last. Hence, there
123 	 * is no race as long as the frame RX is processed before the next TX
124 	 * status, which drivers can ensure, see below.
125 	 *
126 	 * Note that this can only happen if the hardware or firmware can
127 	 * actually add STAs to the filter list, if this is done by the
128 	 * driver in response to set_tim() (which will only reduce the race
129 	 * this whole filtering tries to solve, not completely solve it)
130 	 * this situation cannot happen.
131 	 *
132 	 * To completely solve this race drivers need to make sure that they
133 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
134 	 *	functions and
135 	 *  (b) always process RX events before TX status events if ordering
136 	 *      can be unknown, for example with different interrupt status
137 	 *	bits.
138 	 *  (c) if PS mode transitions are manual (i.e. the flag
139 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
140 	 *      changes before calling TX status events if ordering can be
141 	 *	unknown.
142 	 */
143 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
144 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
145 		skb_queue_tail(&sta->tx_filtered[ac], skb);
146 		sta_info_recalc_tim(sta);
147 
148 		if (!timer_pending(&local->sta_cleanup))
149 			mod_timer(&local->sta_cleanup,
150 				  round_jiffies(jiffies +
151 						STA_INFO_CLEANUP_INTERVAL));
152 		return;
153 	}
154 
155 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
156 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
157 		/* Software retry the packet once */
158 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
159 		ieee80211_add_pending_skb(local, skb);
160 		return;
161 	}
162 
163 	ps_dbg_ratelimited(sta->sdata,
164 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
165 			   skb_queue_len(&sta->tx_filtered[ac]),
166 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
167 	ieee80211_free_txskb(&local->hw, skb);
168 }
169 
170 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
171 {
172 	struct tid_ampdu_tx *tid_tx;
173 
174 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
175 	if (!tid_tx || !tid_tx->bar_pending)
176 		return;
177 
178 	tid_tx->bar_pending = false;
179 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
180 }
181 
182 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
183 {
184 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
185 	struct ieee80211_local *local = sta->local;
186 	struct ieee80211_sub_if_data *sdata = sta->sdata;
187 	struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
188 
189 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
190 		sta->status_stats.last_ack = jiffies;
191 		if (txinfo->status.is_valid_ack_signal) {
192 			sta->status_stats.last_ack_signal =
193 					 (s8)txinfo->status.ack_signal;
194 			sta->status_stats.ack_signal_filled = true;
195 			ewma_avg_signal_add(&sta->status_stats.avg_ack_signal,
196 					    -txinfo->status.ack_signal);
197 		}
198 	}
199 
200 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
201 		struct ieee80211_hdr *hdr = (void *) skb->data;
202 		u8 *qc = ieee80211_get_qos_ctl(hdr);
203 		u16 tid = qc[0] & 0xf;
204 
205 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
206 	}
207 
208 	if (ieee80211_is_action(mgmt->frame_control) &&
209 	    !ieee80211_has_protected(mgmt->frame_control) &&
210 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
211 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
212 	    ieee80211_sdata_running(sdata)) {
213 		enum ieee80211_smps_mode smps_mode;
214 
215 		switch (mgmt->u.action.u.ht_smps.smps_control) {
216 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
217 			smps_mode = IEEE80211_SMPS_DYNAMIC;
218 			break;
219 		case WLAN_HT_SMPS_CONTROL_STATIC:
220 			smps_mode = IEEE80211_SMPS_STATIC;
221 			break;
222 		case WLAN_HT_SMPS_CONTROL_DISABLED:
223 		default: /* shouldn't happen since we don't send that */
224 			smps_mode = IEEE80211_SMPS_OFF;
225 			break;
226 		}
227 
228 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
229 			/*
230 			 * This update looks racy, but isn't -- if we come
231 			 * here we've definitely got a station that we're
232 			 * talking to, and on a managed interface that can
233 			 * only be the AP. And the only other place updating
234 			 * this variable in managed mode is before association.
235 			 */
236 			sdata->smps_mode = smps_mode;
237 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
238 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
239 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
240 			sta->known_smps_mode = smps_mode;
241 		}
242 	}
243 }
244 
245 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
246 {
247 	struct tid_ampdu_tx *tid_tx;
248 
249 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
250 	if (!tid_tx)
251 		return;
252 
253 	tid_tx->failed_bar_ssn = ssn;
254 	tid_tx->bar_pending = true;
255 }
256 
257 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
258 {
259 	int len = sizeof(struct ieee80211_radiotap_header);
260 
261 	/* IEEE80211_RADIOTAP_RATE rate */
262 	if (info->status.rates[0].idx >= 0 &&
263 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
264 					     IEEE80211_TX_RC_VHT_MCS)))
265 		len += 2;
266 
267 	/* IEEE80211_RADIOTAP_TX_FLAGS */
268 	len += 2;
269 
270 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
271 	len += 1;
272 
273 	/* IEEE80211_RADIOTAP_MCS
274 	 * IEEE80211_RADIOTAP_VHT */
275 	if (info->status.rates[0].idx >= 0) {
276 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
277 			len += 3;
278 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
279 			len = ALIGN(len, 2) + 12;
280 	}
281 
282 	return len;
283 }
284 
285 static void
286 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
287 				 struct ieee80211_supported_band *sband,
288 				 struct sk_buff *skb, int retry_count,
289 				 int rtap_len, int shift)
290 {
291 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
292 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
293 	struct ieee80211_radiotap_header *rthdr;
294 	unsigned char *pos;
295 	u16 txflags;
296 
297 	rthdr = skb_push(skb, rtap_len);
298 
299 	memset(rthdr, 0, rtap_len);
300 	rthdr->it_len = cpu_to_le16(rtap_len);
301 	rthdr->it_present =
302 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
303 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
304 	pos = (unsigned char *)(rthdr + 1);
305 
306 	/*
307 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
308 	 *	extensions proposal contains, we can actually report
309 	 *	the whole set of tries we did.
310 	 */
311 
312 	/* IEEE80211_RADIOTAP_RATE */
313 	if (info->status.rates[0].idx >= 0 &&
314 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
315 					     IEEE80211_TX_RC_VHT_MCS))) {
316 		u16 rate;
317 
318 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
319 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
320 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
321 		/* padding for tx flags */
322 		pos += 2;
323 	}
324 
325 	/* IEEE80211_RADIOTAP_TX_FLAGS */
326 	txflags = 0;
327 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
328 	    !is_multicast_ether_addr(hdr->addr1))
329 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
330 
331 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
332 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
333 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
334 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
335 
336 	put_unaligned_le16(txflags, pos);
337 	pos += 2;
338 
339 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
340 	/* for now report the total retry_count */
341 	*pos = retry_count;
342 	pos++;
343 
344 	if (info->status.rates[0].idx < 0)
345 		return;
346 
347 	/* IEEE80211_RADIOTAP_MCS
348 	 * IEEE80211_RADIOTAP_VHT */
349 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
350 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
351 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
352 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
353 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
354 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
355 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
356 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
357 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
358 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
359 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
360 		pos[2] = info->status.rates[0].idx;
361 		pos += 3;
362 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
363 		u16 known = local->hw.radiotap_vht_details &
364 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
365 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
366 
367 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
368 
369 		/* required alignment from rthdr */
370 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
371 
372 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
373 		put_unaligned_le16(known, pos);
374 		pos += 2;
375 
376 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
377 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
378 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
379 		pos++;
380 
381 		/* u8 bandwidth */
382 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
383 			*pos = 1;
384 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
385 			*pos = 4;
386 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
387 			*pos = 11;
388 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
389 			*pos = 0;
390 		pos++;
391 
392 		/* u8 mcs_nss[4] */
393 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
394 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
395 		pos += 4;
396 
397 		/* u8 coding */
398 		pos++;
399 		/* u8 group_id */
400 		pos++;
401 		/* u16 partial_aid */
402 		pos += 2;
403 	}
404 }
405 
406 /*
407  * Handles the tx for TDLS teardown frames.
408  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
409  */
410 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
411 					struct ieee80211_sub_if_data *sdata,
412 					struct sk_buff *skb, u32 flags)
413 {
414 	struct sk_buff *teardown_skb;
415 	struct sk_buff *orig_teardown_skb;
416 	bool is_teardown = false;
417 
418 	/* Get the teardown data we need and free the lock */
419 	spin_lock(&sdata->u.mgd.teardown_lock);
420 	teardown_skb = sdata->u.mgd.teardown_skb;
421 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
422 	if ((skb == orig_teardown_skb) && teardown_skb) {
423 		sdata->u.mgd.teardown_skb = NULL;
424 		sdata->u.mgd.orig_teardown_skb = NULL;
425 		is_teardown = true;
426 	}
427 	spin_unlock(&sdata->u.mgd.teardown_lock);
428 
429 	if (is_teardown) {
430 		/* This mechanism relies on being able to get ACKs */
431 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
432 
433 		/* Check if peer has ACKed */
434 		if (flags & IEEE80211_TX_STAT_ACK) {
435 			dev_kfree_skb_any(teardown_skb);
436 		} else {
437 			tdls_dbg(sdata,
438 				 "TDLS Resending teardown through AP\n");
439 
440 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
441 		}
442 	}
443 }
444 
445 static struct ieee80211_sub_if_data *
446 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
447 {
448 	struct ieee80211_sub_if_data *sdata;
449 
450 	if (skb->dev) {
451 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
452 			if (!sdata->dev)
453 				continue;
454 
455 			if (skb->dev == sdata->dev)
456 				return sdata;
457 		}
458 
459 		return NULL;
460 	}
461 
462 	return rcu_dereference(local->p2p_sdata);
463 }
464 
465 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
466 				     struct ieee80211_tx_info *info,
467 				     bool acked, bool dropped)
468 {
469 	struct sk_buff *skb;
470 	unsigned long flags;
471 
472 	spin_lock_irqsave(&local->ack_status_lock, flags);
473 	skb = idr_remove(&local->ack_status_frames, info->ack_frame_id);
474 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
475 
476 	if (!skb)
477 		return;
478 
479 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
480 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
481 		struct ieee80211_sub_if_data *sdata;
482 		struct ieee80211_hdr *hdr = (void *)skb->data;
483 
484 		rcu_read_lock();
485 		sdata = ieee80211_sdata_from_skb(local, skb);
486 		if (sdata) {
487 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
488 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
489 				cfg80211_probe_status(sdata->dev, hdr->addr1,
490 						      cookie, acked,
491 						      info->status.ack_signal,
492 						      info->status.is_valid_ack_signal,
493 						      GFP_ATOMIC);
494 			else
495 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
496 							skb->data, skb->len,
497 							acked, GFP_ATOMIC);
498 		}
499 		rcu_read_unlock();
500 
501 		dev_kfree_skb_any(skb);
502 	} else if (dropped) {
503 		dev_kfree_skb_any(skb);
504 	} else {
505 		/* consumes skb */
506 		skb_complete_wifi_ack(skb, acked);
507 	}
508 }
509 
510 static void ieee80211_report_used_skb(struct ieee80211_local *local,
511 				      struct sk_buff *skb, bool dropped)
512 {
513 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
514 	struct ieee80211_hdr *hdr = (void *)skb->data;
515 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
516 
517 	if (dropped)
518 		acked = false;
519 
520 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
521 		struct ieee80211_sub_if_data *sdata;
522 
523 		rcu_read_lock();
524 
525 		sdata = ieee80211_sdata_from_skb(local, skb);
526 
527 		if (!sdata) {
528 			skb->dev = NULL;
529 		} else {
530 			unsigned int hdr_size =
531 				ieee80211_hdrlen(hdr->frame_control);
532 
533 			/* Check to see if packet is a TDLS teardown packet */
534 			if (ieee80211_is_data(hdr->frame_control) &&
535 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
536 			     WLAN_TDLS_TEARDOWN))
537 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
538 							    info->flags);
539 			else
540 				ieee80211_mgd_conn_tx_status(sdata,
541 							     hdr->frame_control,
542 							     acked);
543 		}
544 
545 		rcu_read_unlock();
546 	} else if (info->ack_frame_id) {
547 		ieee80211_report_ack_skb(local, info, acked, dropped);
548 	}
549 
550 	if (!dropped && skb->destructor) {
551 		skb->wifi_acked_valid = 1;
552 		skb->wifi_acked = acked;
553 	}
554 
555 	ieee80211_led_tx(local);
556 
557 	if (skb_has_frag_list(skb)) {
558 		kfree_skb_list(skb_shinfo(skb)->frag_list);
559 		skb_shinfo(skb)->frag_list = NULL;
560 	}
561 }
562 
563 /*
564  * Use a static threshold for now, best value to be determined
565  * by testing ...
566  * Should it depend on:
567  *  - on # of retransmissions
568  *  - current throughput (higher value for higher tpt)?
569  */
570 #define STA_LOST_PKT_THRESHOLD	50
571 #define STA_LOST_TDLS_PKT_THRESHOLD	10
572 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
573 
574 static void ieee80211_lost_packet(struct sta_info *sta,
575 				  struct ieee80211_tx_info *info)
576 {
577 	/* If driver relies on its own algorithm for station kickout, skip
578 	 * mac80211 packet loss mechanism.
579 	 */
580 	if (ieee80211_hw_check(&sta->local->hw, REPORTS_LOW_ACK))
581 		return;
582 
583 	/* This packet was aggregated but doesn't carry status info */
584 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
585 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
586 		return;
587 
588 	sta->status_stats.lost_packets++;
589 	if (!sta->sta.tdls &&
590 	    sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD)
591 		return;
592 
593 	/*
594 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
595 	 * of the last packets were lost, and that no ACK was received in the
596 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
597 	 * mechanism.
598 	 */
599 	if (sta->sta.tdls &&
600 	    (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
601 	     time_before(jiffies,
602 			 sta->status_stats.last_tdls_pkt_time +
603 			 STA_LOST_TDLS_PKT_TIME)))
604 		return;
605 
606 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
607 				    sta->status_stats.lost_packets, GFP_ATOMIC);
608 	sta->status_stats.lost_packets = 0;
609 }
610 
611 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
612 				  struct ieee80211_tx_info *info,
613 				  int *retry_count)
614 {
615 	int rates_idx = -1;
616 	int count = -1;
617 	int i;
618 
619 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
620 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
621 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
622 			/* just the first aggr frame carry status info */
623 			info->status.rates[i].idx = -1;
624 			info->status.rates[i].count = 0;
625 			break;
626 		} else if (info->status.rates[i].idx < 0) {
627 			break;
628 		} else if (i >= hw->max_report_rates) {
629 			/* the HW cannot have attempted that rate */
630 			info->status.rates[i].idx = -1;
631 			info->status.rates[i].count = 0;
632 			break;
633 		}
634 
635 		count += info->status.rates[i].count;
636 	}
637 	rates_idx = i - 1;
638 
639 	if (count < 0)
640 		count = 0;
641 
642 	*retry_count = count;
643 	return rates_idx;
644 }
645 
646 void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
647 			  struct ieee80211_supported_band *sband,
648 			  int retry_count, int shift, bool send_to_cooked)
649 {
650 	struct sk_buff *skb2;
651 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
652 	struct ieee80211_sub_if_data *sdata;
653 	struct net_device *prev_dev = NULL;
654 	int rtap_len;
655 
656 	/* send frame to monitor interfaces now */
657 	rtap_len = ieee80211_tx_radiotap_len(info);
658 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
659 		pr_err("ieee80211_tx_status: headroom too small\n");
660 		dev_kfree_skb(skb);
661 		return;
662 	}
663 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
664 					 rtap_len, shift);
665 
666 	/* XXX: is this sufficient for BPF? */
667 	skb_reset_mac_header(skb);
668 	skb->ip_summed = CHECKSUM_UNNECESSARY;
669 	skb->pkt_type = PACKET_OTHERHOST;
670 	skb->protocol = htons(ETH_P_802_2);
671 	memset(skb->cb, 0, sizeof(skb->cb));
672 
673 	rcu_read_lock();
674 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
675 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
676 			if (!ieee80211_sdata_running(sdata))
677 				continue;
678 
679 			if ((sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES) &&
680 			    !send_to_cooked)
681 				continue;
682 
683 			if (prev_dev) {
684 				skb2 = skb_clone(skb, GFP_ATOMIC);
685 				if (skb2) {
686 					skb2->dev = prev_dev;
687 					netif_rx(skb2);
688 				}
689 			}
690 
691 			prev_dev = sdata->dev;
692 		}
693 	}
694 	if (prev_dev) {
695 		skb->dev = prev_dev;
696 		netif_rx(skb);
697 		skb = NULL;
698 	}
699 	rcu_read_unlock();
700 	dev_kfree_skb(skb);
701 }
702 
703 static void __ieee80211_tx_status(struct ieee80211_hw *hw,
704 				  struct ieee80211_tx_status *status)
705 {
706 	struct sk_buff *skb = status->skb;
707 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
708 	struct ieee80211_local *local = hw_to_local(hw);
709 	struct ieee80211_tx_info *info = status->info;
710 	struct sta_info *sta;
711 	__le16 fc;
712 	struct ieee80211_supported_band *sband;
713 	int retry_count;
714 	int rates_idx;
715 	bool send_to_cooked;
716 	bool acked;
717 	struct ieee80211_bar *bar;
718 	int shift = 0;
719 	int tid = IEEE80211_NUM_TIDS;
720 
721 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
722 
723 	sband = local->hw.wiphy->bands[info->band];
724 	fc = hdr->frame_control;
725 
726 	if (status->sta) {
727 		sta = container_of(status->sta, struct sta_info, sta);
728 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
729 
730 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
731 			clear_sta_flag(sta, WLAN_STA_SP);
732 
733 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
734 
735 		/* mesh Peer Service Period support */
736 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
737 		    ieee80211_is_data_qos(fc))
738 			ieee80211_mpsp_trigger_process(
739 				ieee80211_get_qos_ctl(hdr), sta, true, acked);
740 
741 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
742 			/*
743 			 * The STA is in power save mode, so assume
744 			 * that this TX packet failed because of that.
745 			 */
746 			ieee80211_handle_filtered_frame(local, sta, skb);
747 			return;
748 		}
749 
750 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
751 		    (ieee80211_is_data(hdr->frame_control)) &&
752 		    (rates_idx != -1))
753 			sta->tx_stats.last_rate =
754 				info->status.rates[rates_idx];
755 
756 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
757 		    (ieee80211_is_data_qos(fc))) {
758 			u16 ssn;
759 			u8 *qc;
760 
761 			qc = ieee80211_get_qos_ctl(hdr);
762 			tid = qc[0] & 0xf;
763 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
764 						& IEEE80211_SCTL_SEQ);
765 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
766 					   tid, ssn);
767 		} else if (ieee80211_is_data_qos(fc)) {
768 			u8 *qc = ieee80211_get_qos_ctl(hdr);
769 
770 			tid = qc[0] & 0xf;
771 		}
772 
773 		if (!acked && ieee80211_is_back_req(fc)) {
774 			u16 control;
775 
776 			/*
777 			 * BAR failed, store the last SSN and retry sending
778 			 * the BAR when the next unicast transmission on the
779 			 * same TID succeeds.
780 			 */
781 			bar = (struct ieee80211_bar *) skb->data;
782 			control = le16_to_cpu(bar->control);
783 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
784 				u16 ssn = le16_to_cpu(bar->start_seq_num);
785 
786 				tid = (control &
787 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
788 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
789 
790 				ieee80211_set_bar_pending(sta, tid, ssn);
791 			}
792 		}
793 
794 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
795 			ieee80211_handle_filtered_frame(local, sta, skb);
796 			return;
797 		} else {
798 			if (!acked)
799 				sta->status_stats.retry_failed++;
800 			sta->status_stats.retry_count += retry_count;
801 
802 			if (ieee80211_is_data_present(fc)) {
803 				if (!acked)
804 					sta->status_stats.msdu_failed[tid]++;
805 
806 				sta->status_stats.msdu_retries[tid] +=
807 					retry_count;
808 			}
809 		}
810 
811 		rate_control_tx_status(local, sband, status);
812 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
813 			ieee80211s_update_metric(local, sta, status);
814 
815 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
816 			ieee80211_frame_acked(sta, skb);
817 
818 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
819 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
820 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
821 						acked, info->status.tx_time);
822 
823 		if (info->status.tx_time &&
824 		    wiphy_ext_feature_isset(local->hw.wiphy,
825 					    NL80211_EXT_FEATURE_AIRTIME_FAIRNESS))
826 			ieee80211_sta_register_airtime(&sta->sta, tid,
827 						       info->status.tx_time, 0);
828 
829 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
830 			if (info->flags & IEEE80211_TX_STAT_ACK) {
831 				if (sta->status_stats.lost_packets)
832 					sta->status_stats.lost_packets = 0;
833 
834 				/* Track when last TDLS packet was ACKed */
835 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
836 					sta->status_stats.last_tdls_pkt_time =
837 						jiffies;
838 			} else {
839 				ieee80211_lost_packet(sta, info);
840 			}
841 		}
842 	}
843 
844 	/* SNMP counters
845 	 * Fragments are passed to low-level drivers as separate skbs, so these
846 	 * are actually fragments, not frames. Update frame counters only for
847 	 * the first fragment of the frame. */
848 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
849 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
850 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
851 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
852 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
853 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
854 			if (retry_count > 0)
855 				I802_DEBUG_INC(local->dot11RetryCount);
856 			if (retry_count > 1)
857 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
858 		}
859 
860 		/* This counter shall be incremented for an acknowledged MPDU
861 		 * with an individual address in the address 1 field or an MPDU
862 		 * with a multicast address in the address 1 field of type Data
863 		 * or Management. */
864 		if (!is_multicast_ether_addr(hdr->addr1) ||
865 		    ieee80211_is_data(fc) ||
866 		    ieee80211_is_mgmt(fc))
867 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
868 	} else {
869 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
870 			I802_DEBUG_INC(local->dot11FailedCount);
871 	}
872 
873 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
874 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
875 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
876 	    local->ps_sdata && !(local->scanning)) {
877 		if (info->flags & IEEE80211_TX_STAT_ACK) {
878 			local->ps_sdata->u.mgd.flags |=
879 					IEEE80211_STA_NULLFUNC_ACKED;
880 		} else
881 			mod_timer(&local->dynamic_ps_timer, jiffies +
882 					msecs_to_jiffies(10));
883 	}
884 
885 	ieee80211_report_used_skb(local, skb, false);
886 
887 	/* this was a transmitted frame, but now we want to reuse it */
888 	skb_orphan(skb);
889 
890 	/* Need to make a copy before skb->cb gets cleared */
891 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
892 			 !(ieee80211_is_data(fc));
893 
894 	/*
895 	 * This is a bit racy but we can avoid a lot of work
896 	 * with this test...
897 	 */
898 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
899 		dev_kfree_skb(skb);
900 		return;
901 	}
902 
903 	/* send to monitor interfaces */
904 	ieee80211_tx_monitor(local, skb, sband, retry_count, shift, send_to_cooked);
905 }
906 
907 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
908 {
909 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
910 	struct ieee80211_local *local = hw_to_local(hw);
911 	struct ieee80211_tx_status status = {
912 		.skb = skb,
913 		.info = IEEE80211_SKB_CB(skb),
914 	};
915 	struct rhlist_head *tmp;
916 	struct sta_info *sta;
917 
918 	rcu_read_lock();
919 
920 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
921 		/* skip wrong virtual interface */
922 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
923 			continue;
924 
925 		status.sta = &sta->sta;
926 		break;
927 	}
928 
929 	__ieee80211_tx_status(hw, &status);
930 	rcu_read_unlock();
931 }
932 EXPORT_SYMBOL(ieee80211_tx_status);
933 
934 void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
935 			     struct ieee80211_tx_status *status)
936 {
937 	struct ieee80211_local *local = hw_to_local(hw);
938 	struct ieee80211_tx_info *info = status->info;
939 	struct ieee80211_sta *pubsta = status->sta;
940 	struct ieee80211_supported_band *sband;
941 	int retry_count;
942 	bool acked, noack_success;
943 
944 	if (status->skb)
945 		return __ieee80211_tx_status(hw, status);
946 
947 	if (!status->sta)
948 		return;
949 
950 	ieee80211_tx_get_rates(hw, info, &retry_count);
951 
952 	sband = hw->wiphy->bands[info->band];
953 
954 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
955 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
956 
957 	if (pubsta) {
958 		struct sta_info *sta;
959 
960 		sta = container_of(pubsta, struct sta_info, sta);
961 
962 		if (!acked)
963 			sta->status_stats.retry_failed++;
964 		sta->status_stats.retry_count += retry_count;
965 
966 		if (acked) {
967 			sta->status_stats.last_ack = jiffies;
968 
969 			if (sta->status_stats.lost_packets)
970 				sta->status_stats.lost_packets = 0;
971 
972 			/* Track when last TDLS packet was ACKed */
973 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
974 				sta->status_stats.last_tdls_pkt_time = jiffies;
975 		} else if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
976 			return;
977 		} else {
978 			ieee80211_lost_packet(sta, info);
979 		}
980 
981 		rate_control_tx_status(local, sband, status);
982 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
983 			ieee80211s_update_metric(local, sta, status);
984 	}
985 
986 	if (acked || noack_success) {
987 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
988 		if (!pubsta)
989 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
990 		if (retry_count > 0)
991 			I802_DEBUG_INC(local->dot11RetryCount);
992 		if (retry_count > 1)
993 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
994 	} else {
995 		I802_DEBUG_INC(local->dot11FailedCount);
996 	}
997 }
998 EXPORT_SYMBOL(ieee80211_tx_status_ext);
999 
1000 void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
1001 			      struct ieee80211_sta *pubsta,
1002 			      struct ieee80211_tx_info *info)
1003 {
1004 	struct ieee80211_local *local = hw_to_local(hw);
1005 	struct ieee80211_supported_band *sband = hw->wiphy->bands[info->band];
1006 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1007 	struct ieee80211_tx_status status = {
1008 		.info = info,
1009 		.sta = pubsta,
1010 	};
1011 
1012 	rate_control_tx_status(local, sband, &status);
1013 
1014 	if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL))
1015 		sta->tx_stats.last_rate = info->status.rates[0];
1016 }
1017 EXPORT_SYMBOL(ieee80211_tx_rate_update);
1018 
1019 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
1020 {
1021 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1022 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
1023 				    num_packets, GFP_ATOMIC);
1024 }
1025 EXPORT_SYMBOL(ieee80211_report_low_ack);
1026 
1027 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
1028 {
1029 	struct ieee80211_local *local = hw_to_local(hw);
1030 
1031 	ieee80211_report_used_skb(local, skb, true);
1032 	dev_kfree_skb_any(skb);
1033 }
1034 EXPORT_SYMBOL(ieee80211_free_txskb);
1035 
1036 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
1037 			      struct sk_buff_head *skbs)
1038 {
1039 	struct sk_buff *skb;
1040 
1041 	while ((skb = __skb_dequeue(skbs)))
1042 		ieee80211_free_txskb(hw, skb);
1043 }
1044