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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
4  * Copyright 2012-2013, cozybit Inc.
5  * Copyright (C) 2021 Intel Corporation
6  */
7 
8 #include "mesh.h"
9 #include "wme.h"
10 
11 
12 /* mesh PS management */
13 
14 /**
15  * mps_qos_null_get - create pre-addressed QoS Null frame for mesh powersave
16  */
mps_qos_null_get(struct sta_info * sta)17 static struct sk_buff *mps_qos_null_get(struct sta_info *sta)
18 {
19 	struct ieee80211_sub_if_data *sdata = sta->sdata;
20 	struct ieee80211_local *local = sdata->local;
21 	struct ieee80211_hdr *nullfunc; /* use 4addr header */
22 	struct sk_buff *skb;
23 	int size = sizeof(*nullfunc);
24 	__le16 fc;
25 
26 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size + 2);
27 	if (!skb)
28 		return NULL;
29 	skb_reserve(skb, local->hw.extra_tx_headroom);
30 
31 	nullfunc = skb_put(skb, size);
32 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_NULLFUNC);
33 	ieee80211_fill_mesh_addresses(nullfunc, &fc, sta->sta.addr,
34 				      sdata->vif.addr);
35 	nullfunc->frame_control = fc;
36 	nullfunc->duration_id = 0;
37 	nullfunc->seq_ctrl = 0;
38 	/* no address resolution for this frame -> set addr 1 immediately */
39 	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
40 	skb_put_zero(skb, 2); /* append QoS control field */
41 	ieee80211_mps_set_frame_flags(sdata, sta, nullfunc);
42 
43 	return skb;
44 }
45 
46 /**
47  * mps_qos_null_tx - send a QoS Null to indicate link-specific power mode
48  */
mps_qos_null_tx(struct sta_info * sta)49 static void mps_qos_null_tx(struct sta_info *sta)
50 {
51 	struct sk_buff *skb;
52 
53 	skb = mps_qos_null_get(sta);
54 	if (!skb)
55 		return;
56 
57 	mps_dbg(sta->sdata, "announcing peer-specific power mode to %pM\n",
58 		sta->sta.addr);
59 
60 	/* don't unintentionally start a MPSP */
61 	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
62 		u8 *qc = ieee80211_get_qos_ctl((void *) skb->data);
63 
64 		qc[0] |= IEEE80211_QOS_CTL_EOSP;
65 	}
66 
67 	ieee80211_tx_skb(sta->sdata, skb);
68 }
69 
70 /**
71  * ieee80211_mps_local_status_update - track status of local link-specific PMs
72  *
73  * @sdata: local mesh subif
74  *
75  * sets the non-peer power mode and triggers the driver PS (re-)configuration
76  * Return BSS_CHANGED_BEACON if a beacon update is necessary.
77  */
ieee80211_mps_local_status_update(struct ieee80211_sub_if_data * sdata)78 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
79 {
80 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
81 	struct sta_info *sta;
82 	bool peering = false;
83 	int light_sleep_cnt = 0;
84 	int deep_sleep_cnt = 0;
85 	u32 changed = 0;
86 	enum nl80211_mesh_power_mode nonpeer_pm;
87 
88 	rcu_read_lock();
89 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
90 		if (sdata != sta->sdata)
91 			continue;
92 
93 		switch (sta->mesh->plink_state) {
94 		case NL80211_PLINK_OPN_SNT:
95 		case NL80211_PLINK_OPN_RCVD:
96 		case NL80211_PLINK_CNF_RCVD:
97 			peering = true;
98 			break;
99 		case NL80211_PLINK_ESTAB:
100 			if (sta->mesh->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
101 				light_sleep_cnt++;
102 			else if (sta->mesh->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
103 				deep_sleep_cnt++;
104 			break;
105 		default:
106 			break;
107 		}
108 	}
109 	rcu_read_unlock();
110 
111 	/*
112 	 * Set non-peer mode to active during peering/scanning/authentication
113 	 * (see IEEE802.11-2012 13.14.8.3). The non-peer mesh power mode is
114 	 * deep sleep if the local STA is in light or deep sleep towards at
115 	 * least one mesh peer (see 13.14.3.1). Otherwise, set it to the
116 	 * user-configured default value.
117 	 */
118 	if (peering) {
119 		mps_dbg(sdata, "setting non-peer PM to active for peering\n");
120 		nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
121 	} else if (light_sleep_cnt || deep_sleep_cnt) {
122 		mps_dbg(sdata, "setting non-peer PM to deep sleep\n");
123 		nonpeer_pm = NL80211_MESH_POWER_DEEP_SLEEP;
124 	} else {
125 		mps_dbg(sdata, "setting non-peer PM to user value\n");
126 		nonpeer_pm = ifmsh->mshcfg.power_mode;
127 	}
128 
129 	/* need update if sleep counts move between 0 and non-zero */
130 	if (ifmsh->nonpeer_pm != nonpeer_pm ||
131 	    !ifmsh->ps_peers_light_sleep != !light_sleep_cnt ||
132 	    !ifmsh->ps_peers_deep_sleep != !deep_sleep_cnt)
133 		changed = BSS_CHANGED_BEACON;
134 
135 	ifmsh->nonpeer_pm = nonpeer_pm;
136 	ifmsh->ps_peers_light_sleep = light_sleep_cnt;
137 	ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;
138 
139 	return changed;
140 }
141 
142 /**
143  * ieee80211_mps_set_sta_local_pm - set local PM towards a mesh STA
144  *
145  * @sta: mesh STA
146  * @pm: the power mode to set
147  * Return BSS_CHANGED_BEACON if a beacon update is in order.
148  */
ieee80211_mps_set_sta_local_pm(struct sta_info * sta,enum nl80211_mesh_power_mode pm)149 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
150 				   enum nl80211_mesh_power_mode pm)
151 {
152 	struct ieee80211_sub_if_data *sdata = sta->sdata;
153 
154 	if (sta->mesh->local_pm == pm)
155 		return 0;
156 
157 	mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
158 		pm, sta->sta.addr);
159 
160 	sta->mesh->local_pm = pm;
161 
162 	/*
163 	 * announce peer-specific power mode transition
164 	 * (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
165 	 */
166 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
167 		mps_qos_null_tx(sta);
168 
169 	return ieee80211_mps_local_status_update(sdata);
170 }
171 
172 /**
173  * ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
174  *
175  * @sdata: local mesh subif
176  * @sta: mesh STA
177  * @hdr: 802.11 frame header
178  *
179  * see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
180  *
181  * NOTE: sta must be given when an individually-addressed QoS frame header
182  * is handled, for group-addressed and management frames it is not used
183  */
ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee80211_hdr * hdr)184 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
185 				   struct sta_info *sta,
186 				   struct ieee80211_hdr *hdr)
187 {
188 	enum nl80211_mesh_power_mode pm;
189 	u8 *qc;
190 
191 	if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
192 		    ieee80211_is_data_qos(hdr->frame_control) &&
193 		    !sta))
194 		return;
195 
196 	if (is_unicast_ether_addr(hdr->addr1) &&
197 	    ieee80211_is_data_qos(hdr->frame_control) &&
198 	    sta->mesh->plink_state == NL80211_PLINK_ESTAB)
199 		pm = sta->mesh->local_pm;
200 	else
201 		pm = sdata->u.mesh.nonpeer_pm;
202 
203 	if (pm == NL80211_MESH_POWER_ACTIVE)
204 		hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
205 	else
206 		hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
207 
208 	if (!ieee80211_is_data_qos(hdr->frame_control))
209 		return;
210 
211 	qc = ieee80211_get_qos_ctl(hdr);
212 
213 	if ((is_unicast_ether_addr(hdr->addr1) &&
214 	     pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
215 	    (is_multicast_ether_addr(hdr->addr1) &&
216 	     sdata->u.mesh.ps_peers_deep_sleep > 0))
217 		qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
218 	else
219 		qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
220 }
221 
222 /**
223  * ieee80211_mps_sta_status_update - update buffering status of neighbor STA
224  *
225  * @sta: mesh STA
226  *
227  * called after change of peering status or non-peer/peer-specific power mode
228  */
ieee80211_mps_sta_status_update(struct sta_info * sta)229 void ieee80211_mps_sta_status_update(struct sta_info *sta)
230 {
231 	enum nl80211_mesh_power_mode pm;
232 	bool do_buffer;
233 
234 	/* For non-assoc STA, prevent buffering or frame transmission */
235 	if (sta->sta_state < IEEE80211_STA_ASSOC)
236 		return;
237 
238 	/*
239 	 * use peer-specific power mode if peering is established and the
240 	 * peer's power mode is known
241 	 */
242 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
243 	    sta->mesh->peer_pm != NL80211_MESH_POWER_UNKNOWN)
244 		pm = sta->mesh->peer_pm;
245 	else
246 		pm = sta->mesh->nonpeer_pm;
247 
248 	do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
249 
250 	/* clear the MPSP flags for non-peers or active STA */
251 	if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
252 		clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
253 		clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
254 	} else if (!do_buffer) {
255 		clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
256 	}
257 
258 	/* Don't let the same PS state be set twice */
259 	if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
260 		return;
261 
262 	if (do_buffer) {
263 		set_sta_flag(sta, WLAN_STA_PS_STA);
264 		atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
265 		mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
266 			sta->sta.addr);
267 	} else {
268 		ieee80211_sta_ps_deliver_wakeup(sta);
269 	}
270 }
271 
mps_set_sta_peer_pm(struct sta_info * sta,struct ieee80211_hdr * hdr)272 static void mps_set_sta_peer_pm(struct sta_info *sta,
273 				struct ieee80211_hdr *hdr)
274 {
275 	enum nl80211_mesh_power_mode pm;
276 	u8 *qc = ieee80211_get_qos_ctl(hdr);
277 
278 	/*
279 	 * Test Power Management field of frame control (PW) and
280 	 * mesh power save level subfield of QoS control field (PSL)
281 	 *
282 	 * | PM | PSL| Mesh PM |
283 	 * +----+----+---------+
284 	 * | 0  |Rsrv|  Active |
285 	 * | 1  | 0  |  Light  |
286 	 * | 1  | 1  |  Deep   |
287 	 */
288 	if (ieee80211_has_pm(hdr->frame_control)) {
289 		if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
290 			pm = NL80211_MESH_POWER_DEEP_SLEEP;
291 		else
292 			pm = NL80211_MESH_POWER_LIGHT_SLEEP;
293 	} else {
294 		pm = NL80211_MESH_POWER_ACTIVE;
295 	}
296 
297 	if (sta->mesh->peer_pm == pm)
298 		return;
299 
300 	mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
301 		sta->sta.addr, pm);
302 
303 	sta->mesh->peer_pm = pm;
304 
305 	ieee80211_mps_sta_status_update(sta);
306 }
307 
mps_set_sta_nonpeer_pm(struct sta_info * sta,struct ieee80211_hdr * hdr)308 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
309 				   struct ieee80211_hdr *hdr)
310 {
311 	enum nl80211_mesh_power_mode pm;
312 
313 	if (ieee80211_has_pm(hdr->frame_control))
314 		pm = NL80211_MESH_POWER_DEEP_SLEEP;
315 	else
316 		pm = NL80211_MESH_POWER_ACTIVE;
317 
318 	if (sta->mesh->nonpeer_pm == pm)
319 		return;
320 
321 	mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
322 		sta->sta.addr, pm);
323 
324 	sta->mesh->nonpeer_pm = pm;
325 
326 	ieee80211_mps_sta_status_update(sta);
327 }
328 
329 /**
330  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
331  *
332  * @sta: STA info that transmitted the frame
333  * @hdr: IEEE 802.11 (QoS) Header
334  */
ieee80211_mps_rx_h_sta_process(struct sta_info * sta,struct ieee80211_hdr * hdr)335 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
336 				    struct ieee80211_hdr *hdr)
337 {
338 	if (is_unicast_ether_addr(hdr->addr1) &&
339 	    ieee80211_is_data_qos(hdr->frame_control)) {
340 		/*
341 		 * individually addressed QoS Data/Null frames contain
342 		 * peer link-specific PS mode towards the local STA
343 		 */
344 		mps_set_sta_peer_pm(sta, hdr);
345 
346 		/* check for mesh Peer Service Period trigger frames */
347 		ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
348 					       sta, false, false);
349 	} else {
350 		/*
351 		 * can only determine non-peer PS mode
352 		 * (see IEEE802.11-2012 8.2.4.1.7)
353 		 */
354 		mps_set_sta_nonpeer_pm(sta, hdr);
355 	}
356 }
357 
358 
359 /* mesh PS frame release */
360 
mpsp_trigger_send(struct sta_info * sta,bool rspi,bool eosp)361 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
362 {
363 	struct ieee80211_sub_if_data *sdata = sta->sdata;
364 	struct sk_buff *skb;
365 	struct ieee80211_hdr *nullfunc;
366 	struct ieee80211_tx_info *info;
367 	u8 *qc;
368 
369 	skb = mps_qos_null_get(sta);
370 	if (!skb)
371 		return;
372 
373 	nullfunc = (struct ieee80211_hdr *) skb->data;
374 	if (!eosp)
375 		nullfunc->frame_control |=
376 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
377 	/*
378 	 * | RSPI | EOSP |  MPSP triggering   |
379 	 * +------+------+--------------------+
380 	 * |  0   |  0   | local STA is owner |
381 	 * |  0   |  1   | no MPSP (MPSP end) |
382 	 * |  1   |  0   | both STA are owner |
383 	 * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
384 	 */
385 	qc = ieee80211_get_qos_ctl(nullfunc);
386 	if (rspi)
387 		qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
388 	if (eosp)
389 		qc[0] |= IEEE80211_QOS_CTL_EOSP;
390 
391 	info = IEEE80211_SKB_CB(skb);
392 
393 	info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
394 		       IEEE80211_TX_CTL_REQ_TX_STATUS;
395 
396 	mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
397 		rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
398 
399 	ieee80211_tx_skb(sdata, skb);
400 }
401 
402 /**
403  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
404  *
405  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
406  * flag in the QoS Control field. In case the current tailing frame is not a
407  * QoS Data frame, append a QoS Null to carry the flag.
408  */
mpsp_qos_null_append(struct sta_info * sta,struct sk_buff_head * frames)409 static void mpsp_qos_null_append(struct sta_info *sta,
410 				 struct sk_buff_head *frames)
411 {
412 	struct ieee80211_sub_if_data *sdata = sta->sdata;
413 	struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
414 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
415 	struct ieee80211_tx_info *info;
416 
417 	if (ieee80211_is_data_qos(hdr->frame_control))
418 		return;
419 
420 	new_skb = mps_qos_null_get(sta);
421 	if (!new_skb)
422 		return;
423 
424 	mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
425 		sta->sta.addr);
426 	/*
427 	 * This frame has to be transmitted last. Assign lowest priority to
428 	 * make sure it cannot pass other frames when releasing multiple ACs.
429 	 */
430 	new_skb->priority = 1;
431 	skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
432 	ieee80211_set_qos_hdr(sdata, new_skb);
433 
434 	info = IEEE80211_SKB_CB(new_skb);
435 	info->control.vif = &sdata->vif;
436 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
437 
438 	__skb_queue_tail(frames, new_skb);
439 }
440 
441 /**
442  * mps_frame_deliver - transmit frames during mesh powersave
443  *
444  * @sta: STA info to transmit to
445  * @n_frames: number of frames to transmit. -1 for all
446  */
mps_frame_deliver(struct sta_info * sta,int n_frames)447 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
448 {
449 	struct ieee80211_local *local = sta->sdata->local;
450 	int ac;
451 	struct sk_buff_head frames;
452 	struct sk_buff *skb;
453 	bool more_data = false;
454 
455 	skb_queue_head_init(&frames);
456 
457 	/* collect frame(s) from buffers */
458 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
459 		while (n_frames != 0) {
460 			skb = skb_dequeue(&sta->tx_filtered[ac]);
461 			if (!skb) {
462 				skb = skb_dequeue(
463 					&sta->ps_tx_buf[ac]);
464 				if (skb)
465 					local->total_ps_buffered--;
466 			}
467 			if (!skb)
468 				break;
469 			n_frames--;
470 			__skb_queue_tail(&frames, skb);
471 		}
472 
473 		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
474 		    !skb_queue_empty(&sta->ps_tx_buf[ac]))
475 			more_data = true;
476 	}
477 
478 	/* nothing to send? -> EOSP */
479 	if (skb_queue_empty(&frames)) {
480 		mpsp_trigger_send(sta, false, true);
481 		return;
482 	}
483 
484 	/* in a MPSP make sure the last skb is a QoS Data frame */
485 	if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
486 		mpsp_qos_null_append(sta, &frames);
487 
488 	mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
489 		skb_queue_len(&frames), sta->sta.addr);
490 
491 	/* prepare collected frames for transmission */
492 	skb_queue_walk(&frames, skb) {
493 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
494 		struct ieee80211_hdr *hdr = (void *) skb->data;
495 
496 		/*
497 		 * Tell TX path to send this frame even though the
498 		 * STA may still remain is PS mode after this frame
499 		 * exchange.
500 		 */
501 		info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
502 
503 		if (more_data || !skb_queue_is_last(&frames, skb))
504 			hdr->frame_control |=
505 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
506 		else
507 			hdr->frame_control &=
508 				cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
509 
510 		if (skb_queue_is_last(&frames, skb) &&
511 		    ieee80211_is_data_qos(hdr->frame_control)) {
512 			u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
513 
514 			/* MPSP trigger frame ends service period */
515 			*qoshdr |= IEEE80211_QOS_CTL_EOSP;
516 			info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
517 		}
518 	}
519 
520 	ieee80211_add_pending_skbs(local, &frames);
521 	sta_info_recalc_tim(sta);
522 }
523 
524 /**
525  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
526  *
527  * @qc: QoS Control field
528  * @sta: peer to start a MPSP with
529  * @tx: frame was transmitted by the local STA
530  * @acked: frame has been transmitted successfully
531  *
532  * NOTE: active mode STA may only serve as MPSP owner
533  */
ieee80211_mpsp_trigger_process(u8 * qc,struct sta_info * sta,bool tx,bool acked)534 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
535 				    bool tx, bool acked)
536 {
537 	u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
538 	u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
539 
540 	if (tx) {
541 		if (rspi && acked)
542 			set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
543 
544 		if (eosp)
545 			clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
546 		else if (acked &&
547 			 test_sta_flag(sta, WLAN_STA_PS_STA) &&
548 			 !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
549 			mps_frame_deliver(sta, -1);
550 	} else {
551 		if (eosp)
552 			clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
553 		else if (sta->mesh->local_pm != NL80211_MESH_POWER_ACTIVE)
554 			set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
555 
556 		if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
557 			mps_frame_deliver(sta, -1);
558 	}
559 }
560 
561 /**
562  * ieee80211_mps_frame_release - release frames buffered due to mesh power save
563  *
564  * @sta: mesh STA
565  * @elems: IEs of beacon or probe response
566  *
567  * For peers if we have individually-addressed frames buffered or the peer
568  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
569  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
570  * trigger frames. If the neighbour STA is not a peer, only send single frames.
571  */
ieee80211_mps_frame_release(struct sta_info * sta,struct ieee802_11_elems * elems)572 void ieee80211_mps_frame_release(struct sta_info *sta,
573 				 struct ieee802_11_elems *elems)
574 {
575 	int ac, buffer_local = 0;
576 	bool has_buffered = false;
577 
578 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
579 		has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
580 						   sta->mesh->aid);
581 
582 	if (has_buffered)
583 		mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
584 			sta->sta.addr);
585 
586 	/* only transmit to PS STA with announced, non-zero awake window */
587 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
588 	    (!elems->awake_window || !get_unaligned_le16(elems->awake_window)))
589 		return;
590 
591 	if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
592 		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
593 			buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
594 					skb_queue_len(&sta->tx_filtered[ac]);
595 
596 	if (!has_buffered && !buffer_local)
597 		return;
598 
599 	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
600 		mpsp_trigger_send(sta, has_buffered, !buffer_local);
601 	else
602 		mps_frame_deliver(sta, 1);
603 }
604