1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Off-channel operation helpers
4 *
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
11 * Copyright (C) 2019 Intel Corporation
12 */
13#include <linux/export.h>
14#include <net/mac80211.h>
15#include "ieee80211_i.h"
16#include "driver-ops.h"
17
18/*
19 * Tell our hardware to disable PS.
20 * Optionally inform AP that we will go to sleep so that it will buffer
21 * the frames while we are doing off-channel work.  This is optional
22 * because we *may* be doing work on-operating channel, and want our
23 * hardware unconditionally awake, but still let the AP send us normal frames.
24 */
25static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
26{
27	struct ieee80211_local *local = sdata->local;
28	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
29	bool offchannel_ps_enabled = false;
30
31	/* FIXME: what to do when local->pspolling is true? */
32
33	del_timer_sync(&local->dynamic_ps_timer);
34	del_timer_sync(&ifmgd->bcn_mon_timer);
35	del_timer_sync(&ifmgd->conn_mon_timer);
36
37	cancel_work_sync(&local->dynamic_ps_enable_work);
38
39	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
40		offchannel_ps_enabled = true;
41		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
42		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
43	}
44
45	if (!offchannel_ps_enabled ||
46	    !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
47		/*
48		 * If power save was enabled, no need to send a nullfunc
49		 * frame because AP knows that we are sleeping. But if the
50		 * hardware is creating the nullfunc frame for power save
51		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
52		 * enabled) and power save was enabled, the firmware just
53		 * sent a null frame with power save disabled. So we need
54		 * to send a new nullfunc frame to inform the AP that we
55		 * are again sleeping.
56		 */
57		ieee80211_send_nullfunc(local, sdata, true);
58}
59
60/* inform AP that we are awake again */
61static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
62{
63	struct ieee80211_local *local = sdata->local;
64
65	if (!local->ps_sdata)
66		ieee80211_send_nullfunc(local, sdata, false);
67	else if (local->hw.conf.dynamic_ps_timeout > 0) {
68		/*
69		 * the dynamic_ps_timer had been running before leaving the
70		 * operating channel, restart the timer now and send a nullfunc
71		 * frame to inform the AP that we are awake so that AP sends
72		 * the buffered packets (if any).
73		 */
74		ieee80211_send_nullfunc(local, sdata, false);
75		mod_timer(&local->dynamic_ps_timer, jiffies +
76			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
77	}
78
79	ieee80211_sta_reset_beacon_monitor(sdata);
80	ieee80211_sta_reset_conn_monitor(sdata);
81}
82
83void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
84{
85	struct ieee80211_sub_if_data *sdata;
86
87	if (WARN_ON(local->use_chanctx))
88		return;
89
90	/*
91	 * notify the AP about us leaving the channel and stop all
92	 * STA interfaces.
93	 */
94
95	/*
96	 * Stop queues and transmit all frames queued by the driver
97	 * before sending nullfunc to enable powersave at the AP.
98	 */
99	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
100					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
101					false);
102	ieee80211_flush_queues(local, NULL, false);
103
104	mutex_lock(&local->iflist_mtx);
105	list_for_each_entry(sdata, &local->interfaces, list) {
106		if (!ieee80211_sdata_running(sdata))
107			continue;
108
109		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
110		    sdata->vif.type == NL80211_IFTYPE_NAN)
111			continue;
112
113		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
114			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
115
116		/* Check to see if we should disable beaconing. */
117		if (sdata->vif.bss_conf.enable_beacon) {
118			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
119				&sdata->state);
120			sdata->vif.bss_conf.enable_beacon = false;
121			ieee80211_bss_info_change_notify(
122				sdata, BSS_CHANGED_BEACON_ENABLED);
123		}
124
125		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
126		    sdata->u.mgd.associated)
127			ieee80211_offchannel_ps_enable(sdata);
128	}
129	mutex_unlock(&local->iflist_mtx);
130}
131
132void ieee80211_offchannel_return(struct ieee80211_local *local)
133{
134	struct ieee80211_sub_if_data *sdata;
135
136	if (WARN_ON(local->use_chanctx))
137		return;
138
139	mutex_lock(&local->iflist_mtx);
140	list_for_each_entry(sdata, &local->interfaces, list) {
141		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
142			continue;
143
144		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
145			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
146
147		if (!ieee80211_sdata_running(sdata))
148			continue;
149
150		/* Tell AP we're back */
151		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
152		    sdata->u.mgd.associated)
153			ieee80211_offchannel_ps_disable(sdata);
154
155		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
156				       &sdata->state)) {
157			sdata->vif.bss_conf.enable_beacon = true;
158			ieee80211_bss_info_change_notify(
159				sdata, BSS_CHANGED_BEACON_ENABLED);
160		}
161	}
162	mutex_unlock(&local->iflist_mtx);
163
164	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
165					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
166					false);
167}
168
169static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
170{
171	/* was never transmitted */
172	if (roc->frame) {
173		cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
174					roc->frame->data, roc->frame->len,
175					false, GFP_KERNEL);
176		ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
177	}
178
179	if (!roc->mgmt_tx_cookie)
180		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
181						   roc->cookie, roc->chan,
182						   GFP_KERNEL);
183	else
184		cfg80211_tx_mgmt_expired(&roc->sdata->wdev,
185					 roc->mgmt_tx_cookie,
186					 roc->chan, GFP_KERNEL);
187
188	list_del(&roc->list);
189	kfree(roc);
190}
191
192static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
193						 unsigned long now)
194{
195	struct ieee80211_roc_work *roc, *tmp;
196	long remaining_dur_min = LONG_MAX;
197
198	lockdep_assert_held(&local->mtx);
199
200	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
201		long remaining;
202
203		if (!roc->started)
204			break;
205
206		remaining = roc->start_time +
207			    msecs_to_jiffies(roc->duration) -
208			    now;
209
210		/* In case of HW ROC, it is possible that the HW finished the
211		 * ROC session before the actual requested time. In such a case
212		 * end the ROC session (disregarding the remaining time).
213		 */
214		if (roc->abort || roc->hw_begun || remaining <= 0)
215			ieee80211_roc_notify_destroy(roc);
216		else
217			remaining_dur_min = min(remaining_dur_min, remaining);
218	}
219
220	return remaining_dur_min;
221}
222
223static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
224				     unsigned long now)
225{
226	long dur = ieee80211_end_finished_rocs(local, now);
227
228	if (dur == LONG_MAX)
229		return false;
230
231	mod_delayed_work(local->workqueue, &local->roc_work, dur);
232	return true;
233}
234
235static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
236					 unsigned long start_time)
237{
238	if (WARN_ON(roc->notified))
239		return;
240
241	roc->start_time = start_time;
242	roc->started = true;
243
244	if (roc->mgmt_tx_cookie) {
245		if (!WARN_ON(!roc->frame)) {
246			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
247						  roc->chan->band);
248			roc->frame = NULL;
249		}
250	} else {
251		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
252					  roc->chan, roc->req_duration,
253					  GFP_KERNEL);
254	}
255
256	roc->notified = true;
257}
258
259static void ieee80211_hw_roc_start(struct work_struct *work)
260{
261	struct ieee80211_local *local =
262		container_of(work, struct ieee80211_local, hw_roc_start);
263	struct ieee80211_roc_work *roc;
264
265	mutex_lock(&local->mtx);
266
267	list_for_each_entry(roc, &local->roc_list, list) {
268		if (!roc->started)
269			break;
270
271		roc->hw_begun = true;
272		ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
273	}
274
275	mutex_unlock(&local->mtx);
276}
277
278void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
279{
280	struct ieee80211_local *local = hw_to_local(hw);
281
282	local->hw_roc_start_time = jiffies;
283
284	trace_api_ready_on_channel(local);
285
286	ieee80211_queue_work(hw, &local->hw_roc_start);
287}
288EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
289
290static void _ieee80211_start_next_roc(struct ieee80211_local *local)
291{
292	struct ieee80211_roc_work *roc, *tmp;
293	enum ieee80211_roc_type type;
294	u32 min_dur, max_dur;
295
296	lockdep_assert_held(&local->mtx);
297
298	if (WARN_ON(list_empty(&local->roc_list)))
299		return;
300
301	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
302			       list);
303
304	if (WARN_ON(roc->started))
305		return;
306
307	min_dur = roc->duration;
308	max_dur = roc->duration;
309	type = roc->type;
310
311	list_for_each_entry(tmp, &local->roc_list, list) {
312		if (tmp == roc)
313			continue;
314		if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
315			break;
316		max_dur = max(tmp->duration, max_dur);
317		min_dur = min(tmp->duration, min_dur);
318		type = max(tmp->type, type);
319	}
320
321	if (local->ops->remain_on_channel) {
322		int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
323						max_dur, type);
324
325		if (ret) {
326			wiphy_warn(local->hw.wiphy,
327				   "failed to start next HW ROC (%d)\n", ret);
328			/*
329			 * queue the work struct again to avoid recursion
330			 * when multiple failures occur
331			 */
332			list_for_each_entry(tmp, &local->roc_list, list) {
333				if (tmp->sdata != roc->sdata ||
334				    tmp->chan != roc->chan)
335					break;
336				tmp->started = true;
337				tmp->abort = true;
338			}
339			ieee80211_queue_work(&local->hw, &local->hw_roc_done);
340			return;
341		}
342
343		/* we'll notify about the start once the HW calls back */
344		list_for_each_entry(tmp, &local->roc_list, list) {
345			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
346				break;
347			tmp->started = true;
348		}
349	} else {
350		/* If actually operating on the desired channel (with at least
351		 * 20 MHz channel width) don't stop all the operations but still
352		 * treat it as though the ROC operation started properly, so
353		 * other ROC operations won't interfere with this one.
354		 */
355		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
356				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
357				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
358
359		/* start this ROC */
360		ieee80211_recalc_idle(local);
361
362		if (!roc->on_channel) {
363			ieee80211_offchannel_stop_vifs(local);
364
365			local->tmp_channel = roc->chan;
366			ieee80211_hw_config(local, 0);
367		}
368
369		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
370					     msecs_to_jiffies(min_dur));
371
372		/* tell userspace or send frame(s) */
373		list_for_each_entry(tmp, &local->roc_list, list) {
374			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
375				break;
376
377			tmp->on_channel = roc->on_channel;
378			ieee80211_handle_roc_started(tmp, jiffies);
379		}
380	}
381}
382
383void ieee80211_start_next_roc(struct ieee80211_local *local)
384{
385	struct ieee80211_roc_work *roc;
386
387	lockdep_assert_held(&local->mtx);
388
389	if (list_empty(&local->roc_list)) {
390		ieee80211_run_deferred_scan(local);
391		return;
392	}
393
394	/* defer roc if driver is not started (i.e. during reconfig) */
395	if (local->in_reconfig)
396		return;
397
398	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
399			       list);
400
401	if (WARN_ON_ONCE(roc->started))
402		return;
403
404	if (local->ops->remain_on_channel) {
405		_ieee80211_start_next_roc(local);
406	} else {
407		/* delay it a bit */
408		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
409					     round_jiffies_relative(HZ/2));
410	}
411}
412
413static void __ieee80211_roc_work(struct ieee80211_local *local)
414{
415	struct ieee80211_roc_work *roc;
416	bool on_channel;
417
418	lockdep_assert_held(&local->mtx);
419
420	if (WARN_ON(local->ops->remain_on_channel))
421		return;
422
423	roc = list_first_entry_or_null(&local->roc_list,
424				       struct ieee80211_roc_work, list);
425	if (!roc)
426		return;
427
428	if (!roc->started) {
429		WARN_ON(local->use_chanctx);
430		_ieee80211_start_next_roc(local);
431	} else {
432		on_channel = roc->on_channel;
433		if (ieee80211_recalc_sw_work(local, jiffies))
434			return;
435
436		/* careful - roc pointer became invalid during recalc */
437
438		if (!on_channel) {
439			ieee80211_flush_queues(local, NULL, false);
440
441			local->tmp_channel = NULL;
442			ieee80211_hw_config(local, 0);
443
444			ieee80211_offchannel_return(local);
445		}
446
447		ieee80211_recalc_idle(local);
448		ieee80211_start_next_roc(local);
449	}
450}
451
452static void ieee80211_roc_work(struct work_struct *work)
453{
454	struct ieee80211_local *local =
455		container_of(work, struct ieee80211_local, roc_work.work);
456
457	mutex_lock(&local->mtx);
458	__ieee80211_roc_work(local);
459	mutex_unlock(&local->mtx);
460}
461
462static void ieee80211_hw_roc_done(struct work_struct *work)
463{
464	struct ieee80211_local *local =
465		container_of(work, struct ieee80211_local, hw_roc_done);
466
467	mutex_lock(&local->mtx);
468
469	ieee80211_end_finished_rocs(local, jiffies);
470
471	/* if there's another roc, start it now */
472	ieee80211_start_next_roc(local);
473
474	mutex_unlock(&local->mtx);
475}
476
477void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
478{
479	struct ieee80211_local *local = hw_to_local(hw);
480
481	trace_api_remain_on_channel_expired(local);
482
483	ieee80211_queue_work(hw, &local->hw_roc_done);
484}
485EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
486
487static bool
488ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
489				  struct ieee80211_roc_work *new_roc,
490				  struct ieee80211_roc_work *cur_roc)
491{
492	unsigned long now = jiffies;
493	unsigned long remaining;
494
495	if (WARN_ON(!cur_roc->started))
496		return false;
497
498	/* if it was scheduled in the hardware, but not started yet,
499	 * we can only combine if the older one had a longer duration
500	 */
501	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
502		return false;
503
504	remaining = cur_roc->start_time +
505		    msecs_to_jiffies(cur_roc->duration) -
506		    now;
507
508	/* if it doesn't fit entirely, schedule a new one */
509	if (new_roc->duration > jiffies_to_msecs(remaining))
510		return false;
511
512	/* add just after the current one so we combine their finish later */
513	list_add(&new_roc->list, &cur_roc->list);
514
515	/* if the existing one has already begun then let this one also
516	 * begin, otherwise they'll both be marked properly by the work
517	 * struct that runs once the driver notifies us of the beginning
518	 */
519	if (cur_roc->hw_begun) {
520		new_roc->hw_begun = true;
521		ieee80211_handle_roc_started(new_roc, now);
522	}
523
524	return true;
525}
526
527static int ieee80211_start_roc_work(struct ieee80211_local *local,
528				    struct ieee80211_sub_if_data *sdata,
529				    struct ieee80211_channel *channel,
530				    unsigned int duration, u64 *cookie,
531				    struct sk_buff *txskb,
532				    enum ieee80211_roc_type type)
533{
534	struct ieee80211_roc_work *roc, *tmp;
535	bool queued = false, combine_started = true;
536	int ret;
537
538	lockdep_assert_held(&local->mtx);
539
540	if (channel->freq_offset)
541		/* this may work, but is untested */
542		return -EOPNOTSUPP;
543
544	if (local->use_chanctx && !local->ops->remain_on_channel)
545		return -EOPNOTSUPP;
546
547	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
548	if (!roc)
549		return -ENOMEM;
550
551	/*
552	 * If the duration is zero, then the driver
553	 * wouldn't actually do anything. Set it to
554	 * 10 for now.
555	 *
556	 * TODO: cancel the off-channel operation
557	 *       when we get the SKB's TX status and
558	 *       the wait time was zero before.
559	 */
560	if (!duration)
561		duration = 10;
562
563	roc->chan = channel;
564	roc->duration = duration;
565	roc->req_duration = duration;
566	roc->frame = txskb;
567	roc->type = type;
568	roc->sdata = sdata;
569
570	/*
571	 * cookie is either the roc cookie (for normal roc)
572	 * or the SKB (for mgmt TX)
573	 */
574	if (!txskb) {
575		roc->cookie = ieee80211_mgmt_tx_cookie(local);
576		*cookie = roc->cookie;
577	} else {
578		roc->mgmt_tx_cookie = *cookie;
579	}
580
581	/* if there's no need to queue, handle it immediately */
582	if (list_empty(&local->roc_list) &&
583	    !local->scanning && !ieee80211_is_radar_required(local)) {
584		/* if not HW assist, just queue & schedule work */
585		if (!local->ops->remain_on_channel) {
586			list_add_tail(&roc->list, &local->roc_list);
587			ieee80211_queue_delayed_work(&local->hw,
588						     &local->roc_work, 0);
589		} else {
590			/* otherwise actually kick it off here
591			 * (for error handling)
592			 */
593			ret = drv_remain_on_channel(local, sdata, channel,
594						    duration, type);
595			if (ret) {
596				kfree(roc);
597				return ret;
598			}
599			roc->started = true;
600			list_add_tail(&roc->list, &local->roc_list);
601		}
602
603		return 0;
604	}
605
606	/* otherwise handle queueing */
607
608	list_for_each_entry(tmp, &local->roc_list, list) {
609		if (tmp->chan != channel || tmp->sdata != sdata)
610			continue;
611
612		/*
613		 * Extend this ROC if possible: If it hasn't started, add
614		 * just after the new one to combine.
615		 */
616		if (!tmp->started) {
617			list_add(&roc->list, &tmp->list);
618			queued = true;
619			break;
620		}
621
622		if (!combine_started)
623			continue;
624
625		if (!local->ops->remain_on_channel) {
626			/* If there's no hardware remain-on-channel, and
627			 * doing so won't push us over the maximum r-o-c
628			 * we allow, then we can just add the new one to
629			 * the list and mark it as having started now.
630			 * If it would push over the limit, don't try to
631			 * combine with other started ones (that haven't
632			 * been running as long) but potentially sort it
633			 * with others that had the same fate.
634			 */
635			unsigned long now = jiffies;
636			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
637			struct wiphy *wiphy = local->hw.wiphy;
638			u32 max_roc = wiphy->max_remain_on_channel_duration;
639
640			if (elapsed + roc->duration > max_roc) {
641				combine_started = false;
642				continue;
643			}
644
645			list_add(&roc->list, &tmp->list);
646			queued = true;
647			roc->on_channel = tmp->on_channel;
648			ieee80211_handle_roc_started(roc, now);
649			ieee80211_recalc_sw_work(local, now);
650			break;
651		}
652
653		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
654		if (queued)
655			break;
656		/* if it wasn't queued, perhaps it can be combined with
657		 * another that also couldn't get combined previously,
658		 * but no need to check for already started ones, since
659		 * that can't work.
660		 */
661		combine_started = false;
662	}
663
664	if (!queued)
665		list_add_tail(&roc->list, &local->roc_list);
666
667	return 0;
668}
669
670int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
671				struct ieee80211_channel *chan,
672				unsigned int duration, u64 *cookie)
673{
674	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
675	struct ieee80211_local *local = sdata->local;
676	int ret;
677
678	mutex_lock(&local->mtx);
679	ret = ieee80211_start_roc_work(local, sdata, chan,
680				       duration, cookie, NULL,
681				       IEEE80211_ROC_TYPE_NORMAL);
682	mutex_unlock(&local->mtx);
683
684	return ret;
685}
686
687static int ieee80211_cancel_roc(struct ieee80211_local *local,
688				u64 cookie, bool mgmt_tx)
689{
690	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
691	int ret;
692
693	if (!cookie)
694		return -ENOENT;
695
696	flush_work(&local->hw_roc_start);
697
698	mutex_lock(&local->mtx);
699	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
700		if (!mgmt_tx && roc->cookie != cookie)
701			continue;
702		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
703			continue;
704
705		found = roc;
706		break;
707	}
708
709	if (!found) {
710		mutex_unlock(&local->mtx);
711		return -ENOENT;
712	}
713
714	if (!found->started) {
715		ieee80211_roc_notify_destroy(found);
716		goto out_unlock;
717	}
718
719	if (local->ops->remain_on_channel) {
720		ret = drv_cancel_remain_on_channel(local, roc->sdata);
721		if (WARN_ON_ONCE(ret)) {
722			mutex_unlock(&local->mtx);
723			return ret;
724		}
725
726		/* TODO:
727		 * if multiple items were combined here then we really shouldn't
728		 * cancel them all - we should wait for as much time as needed
729		 * for the longest remaining one, and only then cancel ...
730		 */
731		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
732			if (!roc->started)
733				break;
734			if (roc == found)
735				found = NULL;
736			ieee80211_roc_notify_destroy(roc);
737		}
738
739		/* that really must not happen - it was started */
740		WARN_ON(found);
741
742		ieee80211_start_next_roc(local);
743	} else {
744		/* go through work struct to return to the operating channel */
745		found->abort = true;
746		mod_delayed_work(local->workqueue, &local->roc_work, 0);
747	}
748
749 out_unlock:
750	mutex_unlock(&local->mtx);
751
752	return 0;
753}
754
755int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
756				       struct wireless_dev *wdev, u64 cookie)
757{
758	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
759	struct ieee80211_local *local = sdata->local;
760
761	return ieee80211_cancel_roc(local, cookie, false);
762}
763
764int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
765		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
766{
767	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
768	struct ieee80211_local *local = sdata->local;
769	struct sk_buff *skb;
770	struct sta_info *sta;
771	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
772	bool need_offchan = false;
773	u32 flags;
774	int ret;
775	u8 *data;
776
777	if (params->dont_wait_for_ack)
778		flags = IEEE80211_TX_CTL_NO_ACK;
779	else
780		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
781			IEEE80211_TX_CTL_REQ_TX_STATUS;
782
783	if (params->no_cck)
784		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
785
786	switch (sdata->vif.type) {
787	case NL80211_IFTYPE_ADHOC:
788		if (!sdata->vif.bss_conf.ibss_joined)
789			need_offchan = true;
790#ifdef CONFIG_MAC80211_MESH
791		fallthrough;
792	case NL80211_IFTYPE_MESH_POINT:
793		if (ieee80211_vif_is_mesh(&sdata->vif) &&
794		    !sdata->u.mesh.mesh_id_len)
795			need_offchan = true;
796#endif
797		fallthrough;
798	case NL80211_IFTYPE_AP:
799	case NL80211_IFTYPE_AP_VLAN:
800	case NL80211_IFTYPE_P2P_GO:
801		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
802		    !ieee80211_vif_is_mesh(&sdata->vif) &&
803		    !rcu_access_pointer(sdata->bss->beacon))
804			need_offchan = true;
805		if (!ieee80211_is_action(mgmt->frame_control) ||
806		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
807		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
808		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
809			break;
810		rcu_read_lock();
811		sta = sta_info_get_bss(sdata, mgmt->da);
812		rcu_read_unlock();
813		if (!sta)
814			return -ENOLINK;
815		break;
816	case NL80211_IFTYPE_STATION:
817	case NL80211_IFTYPE_P2P_CLIENT:
818		sdata_lock(sdata);
819		if (!sdata->u.mgd.associated ||
820		    (params->offchan && params->wait &&
821		     local->ops->remain_on_channel &&
822		     memcmp(sdata->u.mgd.associated->bssid,
823			    mgmt->bssid, ETH_ALEN)))
824			need_offchan = true;
825		sdata_unlock(sdata);
826		break;
827	case NL80211_IFTYPE_P2P_DEVICE:
828		need_offchan = true;
829		break;
830	case NL80211_IFTYPE_NAN:
831	default:
832		return -EOPNOTSUPP;
833	}
834
835	/* configurations requiring offchan cannot work if no channel has been
836	 * specified
837	 */
838	if (need_offchan && !params->chan)
839		return -EINVAL;
840
841	mutex_lock(&local->mtx);
842
843	/* Check if the operating channel is the requested channel */
844	if (!need_offchan) {
845		struct ieee80211_chanctx_conf *chanctx_conf;
846
847		rcu_read_lock();
848		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
849
850		if (chanctx_conf) {
851			need_offchan = params->chan &&
852				       (params->chan !=
853					chanctx_conf->def.chan);
854		} else if (!params->chan) {
855			ret = -EINVAL;
856			rcu_read_unlock();
857			goto out_unlock;
858		} else {
859			need_offchan = true;
860		}
861		rcu_read_unlock();
862	}
863
864	if (need_offchan && !params->offchan) {
865		ret = -EBUSY;
866		goto out_unlock;
867	}
868
869	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
870	if (!skb) {
871		ret = -ENOMEM;
872		goto out_unlock;
873	}
874	skb_reserve(skb, local->hw.extra_tx_headroom);
875
876	data = skb_put_data(skb, params->buf, params->len);
877
878	/* Update CSA counters */
879	if (sdata->vif.csa_active &&
880	    (sdata->vif.type == NL80211_IFTYPE_AP ||
881	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
882	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
883	    params->n_csa_offsets) {
884		int i;
885		struct beacon_data *beacon = NULL;
886
887		rcu_read_lock();
888
889		if (sdata->vif.type == NL80211_IFTYPE_AP)
890			beacon = rcu_dereference(sdata->u.ap.beacon);
891		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
892			beacon = rcu_dereference(sdata->u.ibss.presp);
893		else if (ieee80211_vif_is_mesh(&sdata->vif))
894			beacon = rcu_dereference(sdata->u.mesh.beacon);
895
896		if (beacon)
897			for (i = 0; i < params->n_csa_offsets; i++)
898				data[params->csa_offsets[i]] =
899					beacon->cntdwn_current_counter;
900
901		rcu_read_unlock();
902	}
903
904	IEEE80211_SKB_CB(skb)->flags = flags;
905
906	skb->dev = sdata->dev;
907
908	if (!params->dont_wait_for_ack) {
909		/* make a copy to preserve the frame contents
910		 * in case of encryption.
911		 */
912		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
913		if (ret) {
914			kfree_skb(skb);
915			goto out_unlock;
916		}
917	} else {
918		/* Assign a dummy non-zero cookie, it's not sent to
919		 * userspace in this case but we rely on its value
920		 * internally in the need_offchan case to distinguish
921		 * mgmt-tx from remain-on-channel.
922		 */
923		*cookie = 0xffffffff;
924	}
925
926	if (!need_offchan) {
927		ieee80211_tx_skb(sdata, skb);
928		ret = 0;
929		goto out_unlock;
930	}
931
932	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
933					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
934	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
935		IEEE80211_SKB_CB(skb)->hw_queue =
936			local->hw.offchannel_tx_hw_queue;
937
938	/* This will handle all kinds of coalescing and immediate TX */
939	ret = ieee80211_start_roc_work(local, sdata, params->chan,
940				       params->wait, cookie, skb,
941				       IEEE80211_ROC_TYPE_MGMT_TX);
942	if (ret)
943		ieee80211_free_txskb(&local->hw, skb);
944 out_unlock:
945	mutex_unlock(&local->mtx);
946	return ret;
947}
948
949int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
950				  struct wireless_dev *wdev, u64 cookie)
951{
952	struct ieee80211_local *local = wiphy_priv(wiphy);
953
954	return ieee80211_cancel_roc(local, cookie, true);
955}
956
957void ieee80211_roc_setup(struct ieee80211_local *local)
958{
959	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
960	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
961	INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
962	INIT_LIST_HEAD(&local->roc_list);
963}
964
965void ieee80211_roc_purge(struct ieee80211_local *local,
966			 struct ieee80211_sub_if_data *sdata)
967{
968	struct ieee80211_roc_work *roc, *tmp;
969	bool work_to_do = false;
970
971	mutex_lock(&local->mtx);
972	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
973		if (sdata && roc->sdata != sdata)
974			continue;
975
976		if (roc->started) {
977			if (local->ops->remain_on_channel) {
978				/* can race, so ignore return value */
979				drv_cancel_remain_on_channel(local, sdata);
980				ieee80211_roc_notify_destroy(roc);
981			} else {
982				roc->abort = true;
983				work_to_do = true;
984			}
985		} else {
986			ieee80211_roc_notify_destroy(roc);
987		}
988	}
989	if (work_to_do)
990		__ieee80211_roc_work(local);
991	mutex_unlock(&local->mtx);
992}
993