xref: /openbmc/linux/net/mac80211/status.c (revision 174cd4b1)
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_free_txskb(&local->hw, skb);
56 		return;
57 	}
58 
59 	/*
60 	 * This skb 'survived' a round-trip through the driver, and
61 	 * hopefully the driver didn't mangle it too badly. However,
62 	 * we can definitely not rely on the control information
63 	 * being correct. Clear it so we don't get junk there, and
64 	 * indicate that it needs new processing, but must not be
65 	 * modified/encrypted again.
66 	 */
67 	memset(&info->control, 0, sizeof(info->control));
68 
69 	info->control.jiffies = jiffies;
70 	info->control.vif = &sta->sdata->vif;
71 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
72 		       IEEE80211_TX_INTFL_RETRANSMISSION;
73 	info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
74 
75 	sta->status_stats.filtered++;
76 
77 	/*
78 	 * Clear more-data bit on filtered frames, it might be set
79 	 * but later frames might time out so it might have to be
80 	 * clear again ... It's all rather unlikely (this frame
81 	 * should time out first, right?) but let's not confuse
82 	 * peers unnecessarily.
83 	 */
84 	if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
85 		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
86 
87 	if (ieee80211_is_data_qos(hdr->frame_control)) {
88 		u8 *p = ieee80211_get_qos_ctl(hdr);
89 		int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
90 
91 		/*
92 		 * Clear EOSP if set, this could happen e.g.
93 		 * if an absence period (us being a P2P GO)
94 		 * shortens the SP.
95 		 */
96 		if (*p & IEEE80211_QOS_CTL_EOSP)
97 			*p &= ~IEEE80211_QOS_CTL_EOSP;
98 		ac = ieee80211_ac_from_tid(tid);
99 	} else {
100 		ac = IEEE80211_AC_BE;
101 	}
102 
103 	/*
104 	 * Clear the TX filter mask for this STA when sending the next
105 	 * packet. If the STA went to power save mode, this will happen
106 	 * when it wakes up for the next time.
107 	 */
108 	set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
109 	ieee80211_clear_fast_xmit(sta);
110 
111 	/*
112 	 * This code races in the following way:
113 	 *
114 	 *  (1) STA sends frame indicating it will go to sleep and does so
115 	 *  (2) hardware/firmware adds STA to filter list, passes frame up
116 	 *  (3) hardware/firmware processes TX fifo and suppresses a frame
117 	 *  (4) we get TX status before having processed the frame and
118 	 *	knowing that the STA has gone to sleep.
119 	 *
120 	 * This is actually quite unlikely even when both those events are
121 	 * processed from interrupts coming in quickly after one another or
122 	 * even at the same time because we queue both TX status events and
123 	 * RX frames to be processed by a tasklet and process them in the
124 	 * same order that they were received or TX status last. Hence, there
125 	 * is no race as long as the frame RX is processed before the next TX
126 	 * status, which drivers can ensure, see below.
127 	 *
128 	 * Note that this can only happen if the hardware or firmware can
129 	 * actually add STAs to the filter list, if this is done by the
130 	 * driver in response to set_tim() (which will only reduce the race
131 	 * this whole filtering tries to solve, not completely solve it)
132 	 * this situation cannot happen.
133 	 *
134 	 * To completely solve this race drivers need to make sure that they
135 	 *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
136 	 *	functions and
137 	 *  (b) always process RX events before TX status events if ordering
138 	 *      can be unknown, for example with different interrupt status
139 	 *	bits.
140 	 *  (c) if PS mode transitions are manual (i.e. the flag
141 	 *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
142 	 *      changes before calling TX status events if ordering can be
143 	 *	unknown.
144 	 */
145 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
146 	    skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
147 		skb_queue_tail(&sta->tx_filtered[ac], skb);
148 		sta_info_recalc_tim(sta);
149 
150 		if (!timer_pending(&local->sta_cleanup))
151 			mod_timer(&local->sta_cleanup,
152 				  round_jiffies(jiffies +
153 						STA_INFO_CLEANUP_INTERVAL));
154 		return;
155 	}
156 
157 	if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
158 	    !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
159 		/* Software retry the packet once */
160 		info->flags |= IEEE80211_TX_INTFL_RETRIED;
161 		ieee80211_add_pending_skb(local, skb);
162 		return;
163 	}
164 
165 	ps_dbg_ratelimited(sta->sdata,
166 			   "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
167 			   skb_queue_len(&sta->tx_filtered[ac]),
168 			   !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
169 	ieee80211_free_txskb(&local->hw, skb);
170 }
171 
172 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
173 {
174 	struct tid_ampdu_tx *tid_tx;
175 
176 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
177 	if (!tid_tx || !tid_tx->bar_pending)
178 		return;
179 
180 	tid_tx->bar_pending = false;
181 	ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
182 }
183 
184 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
185 {
186 	struct ieee80211_mgmt *mgmt = (void *) skb->data;
187 	struct ieee80211_local *local = sta->local;
188 	struct ieee80211_sub_if_data *sdata = sta->sdata;
189 
190 	if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
191 		sta->status_stats.last_ack = jiffies;
192 
193 	if (ieee80211_is_data_qos(mgmt->frame_control)) {
194 		struct ieee80211_hdr *hdr = (void *) skb->data;
195 		u8 *qc = ieee80211_get_qos_ctl(hdr);
196 		u16 tid = qc[0] & 0xf;
197 
198 		ieee80211_check_pending_bar(sta, hdr->addr1, tid);
199 	}
200 
201 	if (ieee80211_is_action(mgmt->frame_control) &&
202 	    mgmt->u.action.category == WLAN_CATEGORY_HT &&
203 	    mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
204 	    ieee80211_sdata_running(sdata)) {
205 		enum ieee80211_smps_mode smps_mode;
206 
207 		switch (mgmt->u.action.u.ht_smps.smps_control) {
208 		case WLAN_HT_SMPS_CONTROL_DYNAMIC:
209 			smps_mode = IEEE80211_SMPS_DYNAMIC;
210 			break;
211 		case WLAN_HT_SMPS_CONTROL_STATIC:
212 			smps_mode = IEEE80211_SMPS_STATIC;
213 			break;
214 		case WLAN_HT_SMPS_CONTROL_DISABLED:
215 		default: /* shouldn't happen since we don't send that */
216 			smps_mode = IEEE80211_SMPS_OFF;
217 			break;
218 		}
219 
220 		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
221 			/*
222 			 * This update looks racy, but isn't -- if we come
223 			 * here we've definitely got a station that we're
224 			 * talking to, and on a managed interface that can
225 			 * only be the AP. And the only other place updating
226 			 * this variable in managed mode is before association.
227 			 */
228 			sdata->smps_mode = smps_mode;
229 			ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
230 		} else if (sdata->vif.type == NL80211_IFTYPE_AP ||
231 			   sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
232 			sta->known_smps_mode = smps_mode;
233 		}
234 	}
235 }
236 
237 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
238 {
239 	struct tid_ampdu_tx *tid_tx;
240 
241 	tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
242 	if (!tid_tx)
243 		return;
244 
245 	tid_tx->failed_bar_ssn = ssn;
246 	tid_tx->bar_pending = true;
247 }
248 
249 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
250 {
251 	int len = sizeof(struct ieee80211_radiotap_header);
252 
253 	/* IEEE80211_RADIOTAP_RATE rate */
254 	if (info->status.rates[0].idx >= 0 &&
255 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
256 					     IEEE80211_TX_RC_VHT_MCS)))
257 		len += 2;
258 
259 	/* IEEE80211_RADIOTAP_TX_FLAGS */
260 	len += 2;
261 
262 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
263 	len += 1;
264 
265 	/* IEEE80211_RADIOTAP_MCS
266 	 * IEEE80211_RADIOTAP_VHT */
267 	if (info->status.rates[0].idx >= 0) {
268 		if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
269 			len += 3;
270 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
271 			len = ALIGN(len, 2) + 12;
272 	}
273 
274 	return len;
275 }
276 
277 static void
278 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
279 				 struct ieee80211_supported_band *sband,
280 				 struct sk_buff *skb, int retry_count,
281 				 int rtap_len, int shift)
282 {
283 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
284 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
285 	struct ieee80211_radiotap_header *rthdr;
286 	unsigned char *pos;
287 	u16 txflags;
288 
289 	rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
290 
291 	memset(rthdr, 0, rtap_len);
292 	rthdr->it_len = cpu_to_le16(rtap_len);
293 	rthdr->it_present =
294 		cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
295 			    (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
296 	pos = (unsigned char *)(rthdr + 1);
297 
298 	/*
299 	 * XXX: Once radiotap gets the bitmap reset thing the vendor
300 	 *	extensions proposal contains, we can actually report
301 	 *	the whole set of tries we did.
302 	 */
303 
304 	/* IEEE80211_RADIOTAP_RATE */
305 	if (info->status.rates[0].idx >= 0 &&
306 	    !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
307 					     IEEE80211_TX_RC_VHT_MCS))) {
308 		u16 rate;
309 
310 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
311 		rate = sband->bitrates[info->status.rates[0].idx].bitrate;
312 		*pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
313 		/* padding for tx flags */
314 		pos += 2;
315 	}
316 
317 	/* IEEE80211_RADIOTAP_TX_FLAGS */
318 	txflags = 0;
319 	if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
320 	    !is_multicast_ether_addr(hdr->addr1))
321 		txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
322 
323 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
324 		txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
325 	if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
326 		txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
327 
328 	put_unaligned_le16(txflags, pos);
329 	pos += 2;
330 
331 	/* IEEE80211_RADIOTAP_DATA_RETRIES */
332 	/* for now report the total retry_count */
333 	*pos = retry_count;
334 	pos++;
335 
336 	if (info->status.rates[0].idx < 0)
337 		return;
338 
339 	/* IEEE80211_RADIOTAP_MCS
340 	 * IEEE80211_RADIOTAP_VHT */
341 	if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
342 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
343 		pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
344 			 IEEE80211_RADIOTAP_MCS_HAVE_GI |
345 			 IEEE80211_RADIOTAP_MCS_HAVE_BW;
346 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
347 			pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
348 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
349 			pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
350 		if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
351 			pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
352 		pos[2] = info->status.rates[0].idx;
353 		pos += 3;
354 	} else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
355 		u16 known = local->hw.radiotap_vht_details &
356 			(IEEE80211_RADIOTAP_VHT_KNOWN_GI |
357 			 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
358 
359 		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
360 
361 		/* required alignment from rthdr */
362 		pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
363 
364 		/* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
365 		put_unaligned_le16(known, pos);
366 		pos += 2;
367 
368 		/* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
369 		if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
370 			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
371 		pos++;
372 
373 		/* u8 bandwidth */
374 		if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
375 			*pos = 1;
376 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
377 			*pos = 4;
378 		else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
379 			*pos = 11;
380 		else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
381 			*pos = 0;
382 		pos++;
383 
384 		/* u8 mcs_nss[4] */
385 		*pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
386 			ieee80211_rate_get_vht_nss(&info->status.rates[0]);
387 		pos += 4;
388 
389 		/* u8 coding */
390 		pos++;
391 		/* u8 group_id */
392 		pos++;
393 		/* u16 partial_aid */
394 		pos += 2;
395 	}
396 }
397 
398 /*
399  * Handles the tx for TDLS teardown frames.
400  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
401  */
402 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
403 					struct ieee80211_sub_if_data *sdata,
404 					struct sk_buff *skb, u32 flags)
405 {
406 	struct sk_buff *teardown_skb;
407 	struct sk_buff *orig_teardown_skb;
408 	bool is_teardown = false;
409 
410 	/* Get the teardown data we need and free the lock */
411 	spin_lock(&sdata->u.mgd.teardown_lock);
412 	teardown_skb = sdata->u.mgd.teardown_skb;
413 	orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
414 	if ((skb == orig_teardown_skb) && teardown_skb) {
415 		sdata->u.mgd.teardown_skb = NULL;
416 		sdata->u.mgd.orig_teardown_skb = NULL;
417 		is_teardown = true;
418 	}
419 	spin_unlock(&sdata->u.mgd.teardown_lock);
420 
421 	if (is_teardown) {
422 		/* This mechanism relies on being able to get ACKs */
423 		WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
424 
425 		/* Check if peer has ACKed */
426 		if (flags & IEEE80211_TX_STAT_ACK) {
427 			dev_kfree_skb_any(teardown_skb);
428 		} else {
429 			tdls_dbg(sdata,
430 				 "TDLS Resending teardown through AP\n");
431 
432 			ieee80211_subif_start_xmit(teardown_skb, skb->dev);
433 		}
434 	}
435 }
436 
437 static struct ieee80211_sub_if_data *
438 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
439 {
440 	struct ieee80211_sub_if_data *sdata;
441 
442 	if (skb->dev) {
443 		list_for_each_entry_rcu(sdata, &local->interfaces, list) {
444 			if (!sdata->dev)
445 				continue;
446 
447 			if (skb->dev == sdata->dev)
448 				return sdata;
449 		}
450 
451 		return NULL;
452 	}
453 
454 	return rcu_dereference(local->p2p_sdata);
455 }
456 
457 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
458 				     struct ieee80211_tx_info *info,
459 				     bool acked, bool dropped)
460 {
461 	struct sk_buff *skb;
462 	unsigned long flags;
463 
464 	spin_lock_irqsave(&local->ack_status_lock, flags);
465 	skb = idr_remove(&local->ack_status_frames, info->ack_frame_id);
466 	spin_unlock_irqrestore(&local->ack_status_lock, flags);
467 
468 	if (!skb)
469 		return;
470 
471 	if (dropped) {
472 		dev_kfree_skb_any(skb);
473 		return;
474 	}
475 
476 	if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
477 		u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
478 		struct ieee80211_sub_if_data *sdata;
479 		struct ieee80211_hdr *hdr = (void *)skb->data;
480 
481 		rcu_read_lock();
482 		sdata = ieee80211_sdata_from_skb(local, skb);
483 		if (sdata) {
484 			if (ieee80211_is_nullfunc(hdr->frame_control) ||
485 			    ieee80211_is_qos_nullfunc(hdr->frame_control))
486 				cfg80211_probe_status(sdata->dev, hdr->addr1,
487 						      cookie, acked,
488 						      GFP_ATOMIC);
489 			else
490 				cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
491 							skb->data, skb->len,
492 							acked, GFP_ATOMIC);
493 		}
494 		rcu_read_unlock();
495 
496 		dev_kfree_skb_any(skb);
497 	} else {
498 		/* consumes skb */
499 		skb_complete_wifi_ack(skb, acked);
500 	}
501 }
502 
503 static void ieee80211_report_used_skb(struct ieee80211_local *local,
504 				      struct sk_buff *skb, bool dropped)
505 {
506 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
507 	struct ieee80211_hdr *hdr = (void *)skb->data;
508 	bool acked = info->flags & IEEE80211_TX_STAT_ACK;
509 
510 	if (dropped)
511 		acked = false;
512 
513 	if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
514 		struct ieee80211_sub_if_data *sdata;
515 
516 		rcu_read_lock();
517 
518 		sdata = ieee80211_sdata_from_skb(local, skb);
519 
520 		if (!sdata) {
521 			skb->dev = NULL;
522 		} else {
523 			unsigned int hdr_size =
524 				ieee80211_hdrlen(hdr->frame_control);
525 
526 			/* Check to see if packet is a TDLS teardown packet */
527 			if (ieee80211_is_data(hdr->frame_control) &&
528 			    (ieee80211_get_tdls_action(skb, hdr_size) ==
529 			     WLAN_TDLS_TEARDOWN))
530 				ieee80211_tdls_td_tx_handle(local, sdata, skb,
531 							    info->flags);
532 			else
533 				ieee80211_mgd_conn_tx_status(sdata,
534 							     hdr->frame_control,
535 							     acked);
536 		}
537 
538 		rcu_read_unlock();
539 	} else if (info->ack_frame_id) {
540 		ieee80211_report_ack_skb(local, info, acked, dropped);
541 	}
542 
543 	if (!dropped && skb->destructor) {
544 		skb->wifi_acked_valid = 1;
545 		skb->wifi_acked = acked;
546 	}
547 }
548 
549 /*
550  * Use a static threshold for now, best value to be determined
551  * by testing ...
552  * Should it depend on:
553  *  - on # of retransmissions
554  *  - current throughput (higher value for higher tpt)?
555  */
556 #define STA_LOST_PKT_THRESHOLD	50
557 #define STA_LOST_TDLS_PKT_THRESHOLD	10
558 #define STA_LOST_TDLS_PKT_TIME		(10*HZ) /* 10secs since last ACK */
559 
560 static void ieee80211_lost_packet(struct sta_info *sta,
561 				  struct ieee80211_tx_info *info)
562 {
563 	/* If driver relies on its own algorithm for station kickout, skip
564 	 * mac80211 packet loss mechanism.
565 	 */
566 	if (ieee80211_hw_check(&sta->local->hw, REPORTS_LOW_ACK))
567 		return;
568 
569 	/* This packet was aggregated but doesn't carry status info */
570 	if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
571 	    !(info->flags & IEEE80211_TX_STAT_AMPDU))
572 		return;
573 
574 	sta->status_stats.lost_packets++;
575 	if (!sta->sta.tdls &&
576 	    sta->status_stats.lost_packets < STA_LOST_PKT_THRESHOLD)
577 		return;
578 
579 	/*
580 	 * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
581 	 * of the last packets were lost, and that no ACK was received in the
582 	 * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
583 	 * mechanism.
584 	 */
585 	if (sta->sta.tdls &&
586 	    (sta->status_stats.lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
587 	     time_before(jiffies,
588 			 sta->status_stats.last_tdls_pkt_time +
589 			 STA_LOST_TDLS_PKT_TIME)))
590 		return;
591 
592 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
593 				    sta->status_stats.lost_packets, GFP_ATOMIC);
594 	sta->status_stats.lost_packets = 0;
595 }
596 
597 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
598 				  struct ieee80211_tx_info *info,
599 				  int *retry_count)
600 {
601 	int rates_idx = -1;
602 	int count = -1;
603 	int i;
604 
605 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
606 		if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
607 		    !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
608 			/* just the first aggr frame carry status info */
609 			info->status.rates[i].idx = -1;
610 			info->status.rates[i].count = 0;
611 			break;
612 		} else if (info->status.rates[i].idx < 0) {
613 			break;
614 		} else if (i >= hw->max_report_rates) {
615 			/* the HW cannot have attempted that rate */
616 			info->status.rates[i].idx = -1;
617 			info->status.rates[i].count = 0;
618 			break;
619 		}
620 
621 		count += info->status.rates[i].count;
622 	}
623 	rates_idx = i - 1;
624 
625 	if (count < 0)
626 		count = 0;
627 
628 	*retry_count = count;
629 	return rates_idx;
630 }
631 
632 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
633 			       struct ieee80211_sta *pubsta,
634 			       struct ieee80211_tx_info *info)
635 {
636 	struct ieee80211_local *local = hw_to_local(hw);
637 	struct ieee80211_supported_band *sband;
638 	int retry_count;
639 	bool acked, noack_success;
640 
641 	ieee80211_tx_get_rates(hw, info, &retry_count);
642 
643 	sband = hw->wiphy->bands[info->band];
644 
645 	acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
646 	noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
647 
648 	if (pubsta) {
649 		struct sta_info *sta;
650 
651 		sta = container_of(pubsta, struct sta_info, sta);
652 
653 		if (!acked)
654 			sta->status_stats.retry_failed++;
655 		sta->status_stats.retry_count += retry_count;
656 
657 		if (acked) {
658 			sta->status_stats.last_ack = jiffies;
659 
660 			if (sta->status_stats.lost_packets)
661 				sta->status_stats.lost_packets = 0;
662 
663 			/* Track when last TDLS packet was ACKed */
664 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
665 				sta->status_stats.last_tdls_pkt_time = jiffies;
666 		} else {
667 			ieee80211_lost_packet(sta, info);
668 		}
669 
670 		rate_control_tx_status_noskb(local, sband, sta, info);
671 	}
672 
673 	if (acked || noack_success) {
674 		I802_DEBUG_INC(local->dot11TransmittedFrameCount);
675 		if (!pubsta)
676 			I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
677 		if (retry_count > 0)
678 			I802_DEBUG_INC(local->dot11RetryCount);
679 		if (retry_count > 1)
680 			I802_DEBUG_INC(local->dot11MultipleRetryCount);
681 	} else {
682 		I802_DEBUG_INC(local->dot11FailedCount);
683 	}
684 }
685 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
686 
687 void ieee80211_tx_monitor(struct ieee80211_local *local, struct sk_buff *skb,
688 			  struct ieee80211_supported_band *sband,
689 			  int retry_count, int shift, bool send_to_cooked)
690 {
691 	struct sk_buff *skb2;
692 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
693 	struct ieee80211_sub_if_data *sdata;
694 	struct net_device *prev_dev = NULL;
695 	int rtap_len;
696 
697 	/* send frame to monitor interfaces now */
698 	rtap_len = ieee80211_tx_radiotap_len(info);
699 	if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
700 		pr_err("ieee80211_tx_status: headroom too small\n");
701 		dev_kfree_skb(skb);
702 		return;
703 	}
704 	ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
705 					 rtap_len, shift);
706 
707 	/* XXX: is this sufficient for BPF? */
708 	skb_reset_mac_header(skb);
709 	skb->ip_summed = CHECKSUM_UNNECESSARY;
710 	skb->pkt_type = PACKET_OTHERHOST;
711 	skb->protocol = htons(ETH_P_802_2);
712 	memset(skb->cb, 0, sizeof(skb->cb));
713 
714 	rcu_read_lock();
715 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
716 		if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
717 			if (!ieee80211_sdata_running(sdata))
718 				continue;
719 
720 			if ((sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES) &&
721 			    !send_to_cooked)
722 				continue;
723 
724 			if (prev_dev) {
725 				skb2 = skb_clone(skb, GFP_ATOMIC);
726 				if (skb2) {
727 					skb2->dev = prev_dev;
728 					netif_rx(skb2);
729 				}
730 			}
731 
732 			prev_dev = sdata->dev;
733 		}
734 	}
735 	if (prev_dev) {
736 		skb->dev = prev_dev;
737 		netif_rx(skb);
738 		skb = NULL;
739 	}
740 	rcu_read_unlock();
741 	dev_kfree_skb(skb);
742 }
743 
744 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
745 {
746 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
747 	struct ieee80211_local *local = hw_to_local(hw);
748 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
749 	__le16 fc;
750 	struct ieee80211_supported_band *sband;
751 	struct rhlist_head *tmp;
752 	struct sta_info *sta;
753 	int retry_count;
754 	int rates_idx;
755 	bool send_to_cooked;
756 	bool acked;
757 	struct ieee80211_bar *bar;
758 	int shift = 0;
759 	int tid = IEEE80211_NUM_TIDS;
760 
761 	rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
762 
763 	rcu_read_lock();
764 
765 	sband = local->hw.wiphy->bands[info->band];
766 	fc = hdr->frame_control;
767 
768 	for_each_sta_info(local, hdr->addr1, sta, tmp) {
769 		/* skip wrong virtual interface */
770 		if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
771 			continue;
772 
773 		shift = ieee80211_vif_get_shift(&sta->sdata->vif);
774 
775 		if (info->flags & IEEE80211_TX_STATUS_EOSP)
776 			clear_sta_flag(sta, WLAN_STA_SP);
777 
778 		acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
779 
780 		/* mesh Peer Service Period support */
781 		if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
782 		    ieee80211_is_data_qos(fc))
783 			ieee80211_mpsp_trigger_process(
784 				ieee80211_get_qos_ctl(hdr), sta, true, acked);
785 
786 		if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
787 			/*
788 			 * The STA is in power save mode, so assume
789 			 * that this TX packet failed because of that.
790 			 */
791 			ieee80211_handle_filtered_frame(local, sta, skb);
792 			rcu_read_unlock();
793 			return;
794 		}
795 
796 		if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
797 		    (ieee80211_is_data(hdr->frame_control)) &&
798 		    (rates_idx != -1))
799 			sta->tx_stats.last_rate =
800 				info->status.rates[rates_idx];
801 
802 		if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
803 		    (ieee80211_is_data_qos(fc))) {
804 			u16 ssn;
805 			u8 *qc;
806 
807 			qc = ieee80211_get_qos_ctl(hdr);
808 			tid = qc[0] & 0xf;
809 			ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
810 						& IEEE80211_SCTL_SEQ);
811 			ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
812 					   tid, ssn);
813 		} else if (ieee80211_is_data_qos(fc)) {
814 			u8 *qc = ieee80211_get_qos_ctl(hdr);
815 
816 			tid = qc[0] & 0xf;
817 		}
818 
819 		if (!acked && ieee80211_is_back_req(fc)) {
820 			u16 control;
821 
822 			/*
823 			 * BAR failed, store the last SSN and retry sending
824 			 * the BAR when the next unicast transmission on the
825 			 * same TID succeeds.
826 			 */
827 			bar = (struct ieee80211_bar *) skb->data;
828 			control = le16_to_cpu(bar->control);
829 			if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
830 				u16 ssn = le16_to_cpu(bar->start_seq_num);
831 
832 				tid = (control &
833 				       IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
834 				      IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
835 
836 				ieee80211_set_bar_pending(sta, tid, ssn);
837 			}
838 		}
839 
840 		if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
841 			ieee80211_handle_filtered_frame(local, sta, skb);
842 			rcu_read_unlock();
843 			return;
844 		} else {
845 			if (!acked)
846 				sta->status_stats.retry_failed++;
847 			sta->status_stats.retry_count += retry_count;
848 
849 			if (ieee80211_is_data_present(fc)) {
850 				if (!acked)
851 					sta->status_stats.msdu_failed[tid]++;
852 
853 				sta->status_stats.msdu_retries[tid] +=
854 					retry_count;
855 			}
856 		}
857 
858 		rate_control_tx_status(local, sband, sta, skb);
859 		if (ieee80211_vif_is_mesh(&sta->sdata->vif))
860 			ieee80211s_update_metric(local, sta, skb);
861 
862 		if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
863 			ieee80211_frame_acked(sta, skb);
864 
865 		if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
866 		    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
867 			ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
868 						acked, info->status.tx_time);
869 
870 		if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
871 			if (info->flags & IEEE80211_TX_STAT_ACK) {
872 				if (sta->status_stats.lost_packets)
873 					sta->status_stats.lost_packets = 0;
874 
875 				/* Track when last TDLS packet was ACKed */
876 				if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
877 					sta->status_stats.last_tdls_pkt_time =
878 						jiffies;
879 			} else {
880 				ieee80211_lost_packet(sta, info);
881 			}
882 		}
883 	}
884 
885 	rcu_read_unlock();
886 
887 	ieee80211_led_tx(local);
888 
889 	/* SNMP counters
890 	 * Fragments are passed to low-level drivers as separate skbs, so these
891 	 * are actually fragments, not frames. Update frame counters only for
892 	 * the first fragment of the frame. */
893 	if ((info->flags & IEEE80211_TX_STAT_ACK) ||
894 	    (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
895 		if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
896 			I802_DEBUG_INC(local->dot11TransmittedFrameCount);
897 			if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
898 				I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
899 			if (retry_count > 0)
900 				I802_DEBUG_INC(local->dot11RetryCount);
901 			if (retry_count > 1)
902 				I802_DEBUG_INC(local->dot11MultipleRetryCount);
903 		}
904 
905 		/* This counter shall be incremented for an acknowledged MPDU
906 		 * with an individual address in the address 1 field or an MPDU
907 		 * with a multicast address in the address 1 field of type Data
908 		 * or Management. */
909 		if (!is_multicast_ether_addr(hdr->addr1) ||
910 		    ieee80211_is_data(fc) ||
911 		    ieee80211_is_mgmt(fc))
912 			I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
913 	} else {
914 		if (ieee80211_is_first_frag(hdr->seq_ctrl))
915 			I802_DEBUG_INC(local->dot11FailedCount);
916 	}
917 
918 	if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
919 	    ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
920 	    !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
921 	    local->ps_sdata && !(local->scanning)) {
922 		if (info->flags & IEEE80211_TX_STAT_ACK) {
923 			local->ps_sdata->u.mgd.flags |=
924 					IEEE80211_STA_NULLFUNC_ACKED;
925 		} else
926 			mod_timer(&local->dynamic_ps_timer, jiffies +
927 					msecs_to_jiffies(10));
928 	}
929 
930 	ieee80211_report_used_skb(local, skb, false);
931 
932 	/* this was a transmitted frame, but now we want to reuse it */
933 	skb_orphan(skb);
934 
935 	/* Need to make a copy before skb->cb gets cleared */
936 	send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
937 			 !(ieee80211_is_data(fc));
938 
939 	/*
940 	 * This is a bit racy but we can avoid a lot of work
941 	 * with this test...
942 	 */
943 	if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
944 		dev_kfree_skb(skb);
945 		return;
946 	}
947 
948 	/* send to monitor interfaces */
949 	ieee80211_tx_monitor(local, skb, sband, retry_count, shift, send_to_cooked);
950 }
951 EXPORT_SYMBOL(ieee80211_tx_status);
952 
953 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
954 {
955 	struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
956 	cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
957 				    num_packets, GFP_ATOMIC);
958 }
959 EXPORT_SYMBOL(ieee80211_report_low_ack);
960 
961 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
962 {
963 	struct ieee80211_local *local = hw_to_local(hw);
964 
965 	ieee80211_report_used_skb(local, skb, true);
966 	dev_kfree_skb_any(skb);
967 }
968 EXPORT_SYMBOL(ieee80211_free_txskb);
969 
970 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
971 			      struct sk_buff_head *skbs)
972 {
973 	struct sk_buff *skb;
974 
975 	while ((skb = __skb_dequeue(skbs)))
976 		ieee80211_free_txskb(hw, skb);
977 }
978