xref: /linux/net/mac80211/status.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 	/*
55 	 * This skb 'survived' a round-trip through the driver, and
56 	 * hopefully the driver didn't mangle it too badly. However,
57 	 * we can definitely not rely on the control information
58 	 * being correct. Clear it so we don't get junk there, and
59 	 * indicate that it needs new processing, but must not be
60 	 * modified/encrypted again.
61 	 */
62 	memset(&info->control, 0, sizeof(info->control));
63 
64 	info->control.jiffies = jiffies;
65 	info->control.vif = &sta->sdata->vif;
66 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
67 		       IEEE80211_TX_INTFL_RETRANSMISSION;
68 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
69 
70 	sta->tx_filtered_count++;
71 
72 	/*
73 	 * Clear more-data bit on filtered frames, it might be set
74 	 * but later frames might time out so it might have to be
75 	 * clear again ... It's all rather unlikely (this frame
76 	 * should time out first, right?) but let's not confuse
77 	 * peers unnecessarily.
78 	 */
79 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
80 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
81 
82 	if (ieee80211_is_data_qos(hdr->frame_control)) {
83 		u8 *p = ieee80211_get_qos_ctl(hdr);
84 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
85 
86 		/*
87 		 * Clear EOSP if set, this could happen e.g.
88 		 * if an absence period (us being a P2P GO)
89 		 * shortens the SP.
90 		 */
91 		if (*p & IEEE80211_QOS_CTL_EOSP)
92 			*p &= ~IEEE80211_QOS_CTL_EOSP;
93 		ac = ieee802_1d_to_ac[tid & 7];
94 	} else {
95 		ac = IEEE80211_AC_BE;
96 	}
97 
98 	/*
99 	 * Clear the TX filter mask for this STA when sending the next
100 	 * packet. If the STA went to power save mode, this will happen
101 	 * when it wakes up for the next time.
102 	 */
103 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
104 	ieee80211_clear_fast_xmit(sta);
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 (ieee80211_hw_check(&local->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(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
419 
420 		/* Check if peer has ACKed */
421 		if (flags & IEEE80211_TX_STAT_ACK) {
422 			dev_kfree_skb_any(teardown_skb);
423 		} else {
424 			tdls_dbg(sdata,
425 				 "TDLS Resending teardown through AP\n");
426 
427 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
428 		}
429 	}
430 }
431 
432 static struct ieee80211_sub_if_data *
433 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
434 {
435 	struct ieee80211_sub_if_data *sdata;
436 
437 	if (skb->dev) {
438 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
439 			if (!sdata->dev)
440 				continue;
441 
442 			if (skb->dev == sdata->dev)
443 				return sdata;
444 		}
445 
446 		return NULL;
447 	}
448 
449 	return rcu_dereference(local->p2p_sdata);
450 }
451 
452 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
453 				     struct ieee80211_tx_info *info,
454 				     bool acked, bool dropped)
455 {
456 	struct sk_buff *skb;
457 	unsigned long flags;
458 
459 	spin_lock_irqsave(&local->ack_status_lock, flags);
460 	skb = idr_find(&local->ack_status_frames, info->ack_frame_id);
461 	if (skb)
462 		idr_remove(&local->ack_status_frames, info->ack_frame_id);
463 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
464 
465 	if (!skb)
466 		return;
467 
468 	if (dropped) {
469 		dev_kfree_skb_any(skb);
470 		return;
471 	}
472 
473 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
474 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
475 		struct ieee80211_sub_if_data *sdata;
476 		struct ieee80211_hdr *hdr = (void *)skb->data;
477 
478 		rcu_read_lock();
479 		sdata = ieee80211_sdata_from_skb(local, skb);
480 		if (sdata) {
481 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
482 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
483 				cfg80211_probe_status(sdata->dev, hdr->addr1,
484 						      cookie, acked,
485 						      GFP_ATOMIC);
486 			else
487 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
488 							skb->data, skb->len,
489 							acked, GFP_ATOMIC);
490 		}
491 		rcu_read_unlock();
492 
493 		dev_kfree_skb_any(skb);
494 	} else {
495 		/* consumes skb */
496 		skb_complete_wifi_ack(skb, acked);
497 	}
498 }
499 
500 static void ieee80211_report_used_skb(struct ieee80211_local *local,
501 				      struct sk_buff *skb, bool dropped)
502 {
503 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
504 	struct ieee80211_hdr *hdr = (void *)skb->data;
505 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
506 
507 	if (dropped)
508 		acked = false;
509 
510 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
511 		struct ieee80211_sub_if_data *sdata;
512 
513 		rcu_read_lock();
514 
515 		sdata = ieee80211_sdata_from_skb(local, skb);
516 
517 		if (!sdata) {
518 			skb->dev = NULL;
519 		} else {
520 			unsigned int hdr_size =
521 				ieee80211_hdrlen(hdr->frame_control);
522 
523 			/* Check to see if packet is a TDLS teardown packet */
524 			if (ieee80211_is_data(hdr->frame_control) &&
525 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
526 			     WLAN_TDLS_TEARDOWN))
527 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
528 							    info->flags);
529 			else
530 				ieee80211_mgd_conn_tx_status(sdata,
531 							     hdr->frame_control,
532 							     acked);
533 		}
534 
535 		rcu_read_unlock();
536 	} else if (info->ack_frame_id) {
537 		ieee80211_report_ack_skb(local, info, acked, dropped);
538 	}
539 }
540 
541 /*
542  * Use a static threshold for now, best value to be determined
543  * by testing ...
544  * Should it depend on:
545  *  - on # of retransmissions
546  *  - current throughput (higher value for higher tpt)?
547  */
548 #define STA_LOST_PKT_THRESHOLD	50
549 #define STA_LOST_TDLS_PKT_THRESHOLD	10
550 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
551 
552 static void ieee80211_lost_packet(struct sta_info *sta,
553 				  struct ieee80211_tx_info *info)
554 {
555 	/* This packet was aggregated but doesn't carry status info */
556 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
557 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
558 		return;
559 
560 	sta->lost_packets++;
561 	if (!sta->sta.tdls && sta->lost_packets < STA_LOST_PKT_THRESHOLD)
562 		return;
563 
564 	/*
565 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
566 	 * of the last packets were lost, and that no ACK was received in the
567 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
568 	 * mechanism.
569 	 */
570 	if (sta->sta.tdls &&
571 	    (sta->lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
572 	     time_before(jiffies,
573 			 sta->last_tdls_pkt_time + STA_LOST_TDLS_PKT_TIME)))
574 		return;
575 
576 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
577 				    sta->lost_packets, GFP_ATOMIC);
578 	sta->lost_packets = 0;
579 }
580 
581 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
582 				  struct ieee80211_tx_info *info,
583 				  int *retry_count)
584 {
585 	int rates_idx = -1;
586 	int count = -1;
587 	int i;
588 
589 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
590 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
591 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
592 			/* just the first aggr frame carry status info */
593 			info->status.rates[i].idx = -1;
594 			info->status.rates[i].count = 0;
595 			break;
596 		} else if (info->status.rates[i].idx < 0) {
597 			break;
598 		} else if (i >= hw->max_report_rates) {
599 			/* the HW cannot have attempted that rate */
600 			info->status.rates[i].idx = -1;
601 			info->status.rates[i].count = 0;
602 			break;
603 		}
604 
605 		count += info->status.rates[i].count;
606 	}
607 	rates_idx = i - 1;
608 
609 	if (count < 0)
610 		count = 0;
611 
612 	*retry_count = count;
613 	return rates_idx;
614 }
615 
616 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
617 			       struct ieee80211_sta *pubsta,
618 			       struct ieee80211_tx_info *info)
619 {
620 	struct ieee80211_local *local = hw_to_local(hw);
621 	struct ieee80211_supported_band *sband;
622 	int retry_count;
623 	int rates_idx;
624 	bool acked, noack_success;
625 
626 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
627 
628 	sband = hw->wiphy->bands[info->band];
629 
630 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
631 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
632 
633 	if (pubsta) {
634 		struct sta_info *sta;
635 
636 		sta = container_of(pubsta, struct sta_info, sta);
637 
638 		if (!acked)
639 			sta->tx_retry_failed++;
640 		sta->tx_retry_count += retry_count;
641 
642 		if (acked) {
643 			sta->last_rx = jiffies;
644 
645 			if (sta->lost_packets)
646 				sta->lost_packets = 0;
647 
648 			/* Track when last TDLS packet was ACKed */
649 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
650 				sta->last_tdls_pkt_time = jiffies;
651 		} else {
652 			ieee80211_lost_packet(sta, info);
653 		}
654 
655 		rate_control_tx_status_noskb(local, sband, sta, info);
656 	}
657 
658 	if (acked || noack_success) {
659 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
660 		if (!pubsta)
661 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
662 		if (retry_count > 0)
663 			I802_DEBUG_INC(local->dot11RetryCount);
664 		if (retry_count > 1)
665 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
666 	} else {
667 		I802_DEBUG_INC(local->dot11FailedCount);
668 	}
669 }
670 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
671 
672 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
673 {
674 	struct sk_buff *skb2;
675 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
676 	struct ieee80211_local *local = hw_to_local(hw);
677 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
678 	__le16 fc;
679 	struct ieee80211_supported_band *sband;
680 	struct ieee80211_sub_if_data *sdata;
681 	struct net_device *prev_dev = NULL;
682 	struct sta_info *sta;
683 	struct rhash_head *tmp;
684 	int retry_count;
685 	int rates_idx;
686 	bool send_to_cooked;
687 	bool acked;
688 	struct ieee80211_bar *bar;
689 	int rtap_len;
690 	int shift = 0;
691 	int tid = IEEE80211_NUM_TIDS;
692 	const struct bucket_table *tbl;
693 
694 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
695 
696 	rcu_read_lock();
697 
698 	sband = local->hw.wiphy->bands[info->band];
699 	fc = hdr->frame_control;
700 
701 	tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
702 
703 	for_each_sta_info(local, tbl, hdr->addr1, sta, tmp) {
704 		/* skip wrong virtual interface */
705 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
706 			continue;
707 
708 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
709 
710 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
711 			clear_sta_flag(sta, WLAN_STA_SP);
712 
713 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
714 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
715 			/*
716 			 * The STA is in power save mode, so assume
717 			 * that this TX packet failed because of that.
718 			 */
719 			ieee80211_handle_filtered_frame(local, sta, skb);
720 			rcu_read_unlock();
721 			return;
722 		}
723 
724 		/* mesh Peer Service Period support */
725 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
726 		    ieee80211_is_data_qos(fc))
727 			ieee80211_mpsp_trigger_process(
728 					ieee80211_get_qos_ctl(hdr),
729 					sta, true, acked);
730 
731 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
732 		    (ieee80211_is_data(hdr->frame_control)) &&
733 		    (rates_idx != -1))
734 			sta->last_tx_rate = info->status.rates[rates_idx];
735 
736 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
737 		    (ieee80211_is_data_qos(fc))) {
738 			u16 ssn;
739 			u8 *qc;
740 
741 			qc = ieee80211_get_qos_ctl(hdr);
742 			tid = qc[0] & 0xf;
743 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
744 						& IEEE80211_SCTL_SEQ);
745 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
746 					   tid, ssn);
747 		} else if (ieee80211_is_data_qos(fc)) {
748 			u8 *qc = ieee80211_get_qos_ctl(hdr);
749 
750 			tid = qc[0] & 0xf;
751 		}
752 
753 		if (!acked && ieee80211_is_back_req(fc)) {
754 			u16 control;
755 
756 			/*
757 			 * BAR failed, store the last SSN and retry sending
758 			 * the BAR when the next unicast transmission on the
759 			 * same TID succeeds.
760 			 */
761 			bar = (struct ieee80211_bar *) skb->data;
762 			control = le16_to_cpu(bar->control);
763 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
764 				u16 ssn = le16_to_cpu(bar->start_seq_num);
765 
766 				tid = (control &
767 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
768 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
769 
770 				ieee80211_set_bar_pending(sta, tid, ssn);
771 			}
772 		}
773 
774 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
775 			ieee80211_handle_filtered_frame(local, sta, skb);
776 			rcu_read_unlock();
777 			return;
778 		} else {
779 			if (!acked)
780 				sta->tx_retry_failed++;
781 			sta->tx_retry_count += retry_count;
782 
783 			if (ieee80211_is_data_present(fc)) {
784 				if (!acked)
785 					sta->tx_msdu_failed[tid]++;
786 				sta->tx_msdu_retries[tid] += retry_count;
787 			}
788 		}
789 
790 		rate_control_tx_status(local, sband, sta, skb);
791 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
792 			ieee80211s_update_metric(local, sta, skb);
793 
794 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
795 			ieee80211_frame_acked(sta, skb);
796 
797 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
798 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
799 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
800 						acked, info->status.tx_time);
801 
802 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
803 			if (info->flags & IEEE80211_TX_STAT_ACK) {
804 				if (sta->lost_packets)
805 					sta->lost_packets = 0;
806 
807 				/* Track when last TDLS packet was ACKed */
808 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
809 					sta->last_tdls_pkt_time = jiffies;
810 			} else {
811 				ieee80211_lost_packet(sta, info);
812 			}
813 		}
814 
815 		if (acked)
816 			sta->last_ack_signal = info->status.ack_signal;
817 	}
818 
819 	rcu_read_unlock();
820 
821 	ieee80211_led_tx(local);
822 
823 	/* SNMP counters
824 	 * Fragments are passed to low-level drivers as separate skbs, so these
825 	 * are actually fragments, not frames. Update frame counters only for
826 	 * the first fragment of the frame. */
827 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
828 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
829 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
830 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
831 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
832 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
833 			if (retry_count > 0)
834 				I802_DEBUG_INC(local->dot11RetryCount);
835 			if (retry_count > 1)
836 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
837 		}
838 
839 		/* This counter shall be incremented for an acknowledged MPDU
840 		 * with an individual address in the address 1 field or an MPDU
841 		 * with a multicast address in the address 1 field of type Data
842 		 * or Management. */
843 		if (!is_multicast_ether_addr(hdr->addr1) ||
844 		    ieee80211_is_data(fc) ||
845 		    ieee80211_is_mgmt(fc))
846 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
847 	} else {
848 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
849 			I802_DEBUG_INC(local->dot11FailedCount);
850 	}
851 
852 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
853 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
854 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
855 	    local->ps_sdata && !(local->scanning)) {
856 		if (info->flags & IEEE80211_TX_STAT_ACK) {
857 			local->ps_sdata->u.mgd.flags |=
858 					IEEE80211_STA_NULLFUNC_ACKED;
859 		} else
860 			mod_timer(&local->dynamic_ps_timer, jiffies +
861 					msecs_to_jiffies(10));
862 	}
863 
864 	ieee80211_report_used_skb(local, skb, false);
865 
866 	/* this was a transmitted frame, but now we want to reuse it */
867 	skb_orphan(skb);
868 
869 	/* Need to make a copy before skb->cb gets cleared */
870 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
871 			 !(ieee80211_is_data(fc));
872 
873 	/*
874 	 * This is a bit racy but we can avoid a lot of work
875 	 * with this test...
876 	 */
877 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
878 		dev_kfree_skb(skb);
879 		return;
880 	}
881 
882 	/* send frame to monitor interfaces now */
883 	rtap_len = ieee80211_tx_radiotap_len(info);
884 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
885 		pr_err("ieee80211_tx_status: headroom too small\n");
886 		dev_kfree_skb(skb);
887 		return;
888 	}
889 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
890 					 rtap_len, shift);
891 
892 	/* XXX: is this sufficient for BPF? */
893 	skb_set_mac_header(skb, 0);
894 	skb->ip_summed = CHECKSUM_UNNECESSARY;
895 	skb->pkt_type = PACKET_OTHERHOST;
896 	skb->protocol = htons(ETH_P_802_2);
897 	memset(skb->cb, 0, sizeof(skb->cb));
898 
899 	rcu_read_lock();
900 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
901 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
902 			if (!ieee80211_sdata_running(sdata))
903 				continue;
904 
905 			if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
906 			    !send_to_cooked)
907 				continue;
908 
909 			if (prev_dev) {
910 				skb2 = skb_clone(skb, GFP_ATOMIC);
911 				if (skb2) {
912 					skb2->dev = prev_dev;
913 					netif_rx(skb2);
914 				}
915 			}
916 
917 			prev_dev = sdata->dev;
918 		}
919 	}
920 	if (prev_dev) {
921 		skb->dev = prev_dev;
922 		netif_rx(skb);
923 		skb = NULL;
924 	}
925 	rcu_read_unlock();
926 	dev_kfree_skb(skb);
927 }
928 EXPORT_SYMBOL(ieee80211_tx_status);
929 
930 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
931 {
932 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
933 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
934 				    num_packets, GFP_ATOMIC);
935 }
936 EXPORT_SYMBOL(ieee80211_report_low_ack);
937 
938 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
939 {
940 	struct ieee80211_local *local = hw_to_local(hw);
941 
942 	ieee80211_report_used_skb(local, skb, true);
943 	dev_kfree_skb_any(skb);
944 }
945 EXPORT_SYMBOL(ieee80211_free_txskb);
946 
947 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
948 			      struct sk_buff_head *skbs)
949 {
950 	struct sk_buff *skb;
951 
952 	while ((skb = __skb_dequeue(skbs)))
953 		ieee80211_free_txskb(hw, skb);
954 }
955