xref: /openbmc/linux/net/mac80211/offchannel.c (revision b285d2ae)
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  */
25 static 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 
30 	local->offchannel_ps_enabled = false;
31 
32 	/* FIXME: what to do when local->pspolling is true? */
33 
34 	del_timer_sync(&local->dynamic_ps_timer);
35 	del_timer_sync(&ifmgd->bcn_mon_timer);
36 	del_timer_sync(&ifmgd->conn_mon_timer);
37 
38 	cancel_work_sync(&local->dynamic_ps_enable_work);
39 
40 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
41 		local->offchannel_ps_enabled = true;
42 		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
43 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
44 	}
45 
46 	if (!local->offchannel_ps_enabled ||
47 	    !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
48 		/*
49 		 * If power save was enabled, no need to send a nullfunc
50 		 * frame because AP knows that we are sleeping. But if the
51 		 * hardware is creating the nullfunc frame for power save
52 		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
53 		 * enabled) and power save was enabled, the firmware just
54 		 * sent a null frame with power save disabled. So we need
55 		 * to send a new nullfunc frame to inform the AP that we
56 		 * are again sleeping.
57 		 */
58 		ieee80211_send_nullfunc(local, sdata, true);
59 }
60 
61 /* inform AP that we are awake again, unless power save is enabled */
62 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
63 {
64 	struct ieee80211_local *local = sdata->local;
65 
66 	if (!local->ps_sdata)
67 		ieee80211_send_nullfunc(local, sdata, false);
68 	else if (local->offchannel_ps_enabled) {
69 		/*
70 		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
71 		 * will send a nullfunc frame with the powersave bit set
72 		 * even though the AP already knows that we are sleeping.
73 		 * This could be avoided by sending a null frame with power
74 		 * save bit disabled before enabling the power save, but
75 		 * this doesn't gain anything.
76 		 *
77 		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
78 		 * to send a nullfunc frame because AP already knows that
79 		 * we are sleeping, let's just enable power save mode in
80 		 * hardware.
81 		 */
82 		/* TODO:  Only set hardware if CONF_PS changed?
83 		 * TODO:  Should we set offchannel_ps_enabled to false?
84 		 */
85 		local->hw.conf.flags |= IEEE80211_CONF_PS;
86 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
87 	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
88 		/*
89 		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
90 		 * had been running before leaving the operating channel,
91 		 * restart the timer now and send a nullfunc frame to inform
92 		 * the AP that we are awake.
93 		 */
94 		ieee80211_send_nullfunc(local, sdata, false);
95 		mod_timer(&local->dynamic_ps_timer, jiffies +
96 			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
97 	}
98 
99 	ieee80211_sta_reset_beacon_monitor(sdata);
100 	ieee80211_sta_reset_conn_monitor(sdata);
101 }
102 
103 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
104 {
105 	struct ieee80211_sub_if_data *sdata;
106 
107 	if (WARN_ON(local->use_chanctx))
108 		return;
109 
110 	/*
111 	 * notify the AP about us leaving the channel and stop all
112 	 * STA interfaces.
113 	 */
114 
115 	/*
116 	 * Stop queues and transmit all frames queued by the driver
117 	 * before sending nullfunc to enable powersave at the AP.
118 	 */
119 	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
120 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
121 					false);
122 	ieee80211_flush_queues(local, NULL, false);
123 
124 	mutex_lock(&local->iflist_mtx);
125 	list_for_each_entry(sdata, &local->interfaces, list) {
126 		if (!ieee80211_sdata_running(sdata))
127 			continue;
128 
129 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
130 		    sdata->vif.type == NL80211_IFTYPE_NAN)
131 			continue;
132 
133 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
134 			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
135 
136 		/* Check to see if we should disable beaconing. */
137 		if (sdata->vif.bss_conf.enable_beacon) {
138 			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
139 				&sdata->state);
140 			sdata->vif.bss_conf.enable_beacon = false;
141 			ieee80211_bss_info_change_notify(
142 				sdata, BSS_CHANGED_BEACON_ENABLED);
143 		}
144 
145 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
146 		    sdata->u.mgd.associated)
147 			ieee80211_offchannel_ps_enable(sdata);
148 	}
149 	mutex_unlock(&local->iflist_mtx);
150 }
151 
152 void ieee80211_offchannel_return(struct ieee80211_local *local)
153 {
154 	struct ieee80211_sub_if_data *sdata;
155 
156 	if (WARN_ON(local->use_chanctx))
157 		return;
158 
159 	mutex_lock(&local->iflist_mtx);
160 	list_for_each_entry(sdata, &local->interfaces, list) {
161 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
162 			continue;
163 
164 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
165 			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
166 
167 		if (!ieee80211_sdata_running(sdata))
168 			continue;
169 
170 		/* Tell AP we're back */
171 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
172 		    sdata->u.mgd.associated)
173 			ieee80211_offchannel_ps_disable(sdata);
174 
175 		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
176 				       &sdata->state)) {
177 			sdata->vif.bss_conf.enable_beacon = true;
178 			ieee80211_bss_info_change_notify(
179 				sdata, BSS_CHANGED_BEACON_ENABLED);
180 		}
181 	}
182 	mutex_unlock(&local->iflist_mtx);
183 
184 	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
185 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
186 					false);
187 }
188 
189 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
190 {
191 	/* was never transmitted */
192 	if (roc->frame) {
193 		cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
194 					roc->frame->data, roc->frame->len,
195 					false, GFP_KERNEL);
196 		ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
197 	}
198 
199 	if (!roc->mgmt_tx_cookie)
200 		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
201 						   roc->cookie, roc->chan,
202 						   GFP_KERNEL);
203 	else
204 		cfg80211_tx_mgmt_expired(&roc->sdata->wdev,
205 					 roc->mgmt_tx_cookie,
206 					 roc->chan, GFP_KERNEL);
207 
208 	list_del(&roc->list);
209 	kfree(roc);
210 }
211 
212 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
213 						 unsigned long now)
214 {
215 	struct ieee80211_roc_work *roc, *tmp;
216 	long remaining_dur_min = LONG_MAX;
217 
218 	lockdep_assert_held(&local->mtx);
219 
220 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
221 		long remaining;
222 
223 		if (!roc->started)
224 			break;
225 
226 		remaining = roc->start_time +
227 			    msecs_to_jiffies(roc->duration) -
228 			    now;
229 
230 		/* In case of HW ROC, it is possible that the HW finished the
231 		 * ROC session before the actual requested time. In such a case
232 		 * end the ROC session (disregarding the remaining time).
233 		 */
234 		if (roc->abort || roc->hw_begun || remaining <= 0)
235 			ieee80211_roc_notify_destroy(roc);
236 		else
237 			remaining_dur_min = min(remaining_dur_min, remaining);
238 	}
239 
240 	return remaining_dur_min;
241 }
242 
243 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
244 				     unsigned long now)
245 {
246 	long dur = ieee80211_end_finished_rocs(local, now);
247 
248 	if (dur == LONG_MAX)
249 		return false;
250 
251 	mod_delayed_work(local->workqueue, &local->roc_work, dur);
252 	return true;
253 }
254 
255 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
256 					 unsigned long start_time)
257 {
258 	if (WARN_ON(roc->notified))
259 		return;
260 
261 	roc->start_time = start_time;
262 	roc->started = true;
263 
264 	if (roc->mgmt_tx_cookie) {
265 		if (!WARN_ON(!roc->frame)) {
266 			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
267 						  roc->chan->band);
268 			roc->frame = NULL;
269 		}
270 	} else {
271 		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
272 					  roc->chan, roc->req_duration,
273 					  GFP_KERNEL);
274 	}
275 
276 	roc->notified = true;
277 }
278 
279 static void ieee80211_hw_roc_start(struct work_struct *work)
280 {
281 	struct ieee80211_local *local =
282 		container_of(work, struct ieee80211_local, hw_roc_start);
283 	struct ieee80211_roc_work *roc;
284 
285 	mutex_lock(&local->mtx);
286 
287 	list_for_each_entry(roc, &local->roc_list, list) {
288 		if (!roc->started)
289 			break;
290 
291 		roc->hw_begun = true;
292 		ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
293 	}
294 
295 	mutex_unlock(&local->mtx);
296 }
297 
298 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
299 {
300 	struct ieee80211_local *local = hw_to_local(hw);
301 
302 	local->hw_roc_start_time = jiffies;
303 
304 	trace_api_ready_on_channel(local);
305 
306 	ieee80211_queue_work(hw, &local->hw_roc_start);
307 }
308 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
309 
310 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
311 {
312 	struct ieee80211_roc_work *roc, *tmp;
313 	enum ieee80211_roc_type type;
314 	u32 min_dur, max_dur;
315 
316 	lockdep_assert_held(&local->mtx);
317 
318 	if (WARN_ON(list_empty(&local->roc_list)))
319 		return;
320 
321 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
322 			       list);
323 
324 	if (WARN_ON(roc->started))
325 		return;
326 
327 	min_dur = roc->duration;
328 	max_dur = roc->duration;
329 	type = roc->type;
330 
331 	list_for_each_entry(tmp, &local->roc_list, list) {
332 		if (tmp == roc)
333 			continue;
334 		if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
335 			break;
336 		max_dur = max(tmp->duration, max_dur);
337 		min_dur = min(tmp->duration, min_dur);
338 		type = max(tmp->type, type);
339 	}
340 
341 	if (local->ops->remain_on_channel) {
342 		int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
343 						max_dur, type);
344 
345 		if (ret) {
346 			wiphy_warn(local->hw.wiphy,
347 				   "failed to start next HW ROC (%d)\n", ret);
348 			/*
349 			 * queue the work struct again to avoid recursion
350 			 * when multiple failures occur
351 			 */
352 			list_for_each_entry(tmp, &local->roc_list, list) {
353 				if (tmp->sdata != roc->sdata ||
354 				    tmp->chan != roc->chan)
355 					break;
356 				tmp->started = true;
357 				tmp->abort = true;
358 			}
359 			ieee80211_queue_work(&local->hw, &local->hw_roc_done);
360 			return;
361 		}
362 
363 		/* we'll notify about the start once the HW calls back */
364 		list_for_each_entry(tmp, &local->roc_list, list) {
365 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
366 				break;
367 			tmp->started = true;
368 		}
369 	} else {
370 		/* If actually operating on the desired channel (with at least
371 		 * 20 MHz channel width) don't stop all the operations but still
372 		 * treat it as though the ROC operation started properly, so
373 		 * other ROC operations won't interfere with this one.
374 		 */
375 		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
376 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
377 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
378 
379 		/* start this ROC */
380 		ieee80211_recalc_idle(local);
381 
382 		if (!roc->on_channel) {
383 			ieee80211_offchannel_stop_vifs(local);
384 
385 			local->tmp_channel = roc->chan;
386 			ieee80211_hw_config(local, 0);
387 		}
388 
389 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
390 					     msecs_to_jiffies(min_dur));
391 
392 		/* tell userspace or send frame(s) */
393 		list_for_each_entry(tmp, &local->roc_list, list) {
394 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
395 				break;
396 
397 			tmp->on_channel = roc->on_channel;
398 			ieee80211_handle_roc_started(tmp, jiffies);
399 		}
400 	}
401 }
402 
403 void ieee80211_start_next_roc(struct ieee80211_local *local)
404 {
405 	struct ieee80211_roc_work *roc;
406 
407 	lockdep_assert_held(&local->mtx);
408 
409 	if (list_empty(&local->roc_list)) {
410 		ieee80211_run_deferred_scan(local);
411 		return;
412 	}
413 
414 	/* defer roc if driver is not started (i.e. during reconfig) */
415 	if (local->in_reconfig)
416 		return;
417 
418 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
419 			       list);
420 
421 	if (WARN_ON_ONCE(roc->started))
422 		return;
423 
424 	if (local->ops->remain_on_channel) {
425 		_ieee80211_start_next_roc(local);
426 	} else {
427 		/* delay it a bit */
428 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
429 					     round_jiffies_relative(HZ/2));
430 	}
431 }
432 
433 static void __ieee80211_roc_work(struct ieee80211_local *local)
434 {
435 	struct ieee80211_roc_work *roc;
436 	bool on_channel;
437 
438 	lockdep_assert_held(&local->mtx);
439 
440 	if (WARN_ON(local->ops->remain_on_channel))
441 		return;
442 
443 	roc = list_first_entry_or_null(&local->roc_list,
444 				       struct ieee80211_roc_work, list);
445 	if (!roc)
446 		return;
447 
448 	if (!roc->started) {
449 		WARN_ON(local->use_chanctx);
450 		_ieee80211_start_next_roc(local);
451 	} else {
452 		on_channel = roc->on_channel;
453 		if (ieee80211_recalc_sw_work(local, jiffies))
454 			return;
455 
456 		/* careful - roc pointer became invalid during recalc */
457 
458 		if (!on_channel) {
459 			ieee80211_flush_queues(local, NULL, false);
460 
461 			local->tmp_channel = NULL;
462 			ieee80211_hw_config(local, 0);
463 
464 			ieee80211_offchannel_return(local);
465 		}
466 
467 		ieee80211_recalc_idle(local);
468 		ieee80211_start_next_roc(local);
469 	}
470 }
471 
472 static void ieee80211_roc_work(struct work_struct *work)
473 {
474 	struct ieee80211_local *local =
475 		container_of(work, struct ieee80211_local, roc_work.work);
476 
477 	mutex_lock(&local->mtx);
478 	__ieee80211_roc_work(local);
479 	mutex_unlock(&local->mtx);
480 }
481 
482 static void ieee80211_hw_roc_done(struct work_struct *work)
483 {
484 	struct ieee80211_local *local =
485 		container_of(work, struct ieee80211_local, hw_roc_done);
486 
487 	mutex_lock(&local->mtx);
488 
489 	ieee80211_end_finished_rocs(local, jiffies);
490 
491 	/* if there's another roc, start it now */
492 	ieee80211_start_next_roc(local);
493 
494 	mutex_unlock(&local->mtx);
495 }
496 
497 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
498 {
499 	struct ieee80211_local *local = hw_to_local(hw);
500 
501 	trace_api_remain_on_channel_expired(local);
502 
503 	ieee80211_queue_work(hw, &local->hw_roc_done);
504 }
505 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
506 
507 static bool
508 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
509 				  struct ieee80211_roc_work *new_roc,
510 				  struct ieee80211_roc_work *cur_roc)
511 {
512 	unsigned long now = jiffies;
513 	unsigned long remaining;
514 
515 	if (WARN_ON(!cur_roc->started))
516 		return false;
517 
518 	/* if it was scheduled in the hardware, but not started yet,
519 	 * we can only combine if the older one had a longer duration
520 	 */
521 	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
522 		return false;
523 
524 	remaining = cur_roc->start_time +
525 		    msecs_to_jiffies(cur_roc->duration) -
526 		    now;
527 
528 	/* if it doesn't fit entirely, schedule a new one */
529 	if (new_roc->duration > jiffies_to_msecs(remaining))
530 		return false;
531 
532 	/* add just after the current one so we combine their finish later */
533 	list_add(&new_roc->list, &cur_roc->list);
534 
535 	/* if the existing one has already begun then let this one also
536 	 * begin, otherwise they'll both be marked properly by the work
537 	 * struct that runs once the driver notifies us of the beginning
538 	 */
539 	if (cur_roc->hw_begun) {
540 		new_roc->hw_begun = true;
541 		ieee80211_handle_roc_started(new_roc, now);
542 	}
543 
544 	return true;
545 }
546 
547 static int ieee80211_start_roc_work(struct ieee80211_local *local,
548 				    struct ieee80211_sub_if_data *sdata,
549 				    struct ieee80211_channel *channel,
550 				    unsigned int duration, u64 *cookie,
551 				    struct sk_buff *txskb,
552 				    enum ieee80211_roc_type type)
553 {
554 	struct ieee80211_roc_work *roc, *tmp;
555 	bool queued = false, combine_started = true;
556 	int ret;
557 
558 	lockdep_assert_held(&local->mtx);
559 
560 	if (channel->freq_offset)
561 		/* this may work, but is untested */
562 		return -EOPNOTSUPP;
563 
564 	if (local->use_chanctx && !local->ops->remain_on_channel)
565 		return -EOPNOTSUPP;
566 
567 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
568 	if (!roc)
569 		return -ENOMEM;
570 
571 	/*
572 	 * If the duration is zero, then the driver
573 	 * wouldn't actually do anything. Set it to
574 	 * 10 for now.
575 	 *
576 	 * TODO: cancel the off-channel operation
577 	 *       when we get the SKB's TX status and
578 	 *       the wait time was zero before.
579 	 */
580 	if (!duration)
581 		duration = 10;
582 
583 	roc->chan = channel;
584 	roc->duration = duration;
585 	roc->req_duration = duration;
586 	roc->frame = txskb;
587 	roc->type = type;
588 	roc->sdata = sdata;
589 
590 	/*
591 	 * cookie is either the roc cookie (for normal roc)
592 	 * or the SKB (for mgmt TX)
593 	 */
594 	if (!txskb) {
595 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
596 		*cookie = roc->cookie;
597 	} else {
598 		roc->mgmt_tx_cookie = *cookie;
599 	}
600 
601 	/* if there's no need to queue, handle it immediately */
602 	if (list_empty(&local->roc_list) &&
603 	    !local->scanning && !ieee80211_is_radar_required(local)) {
604 		/* if not HW assist, just queue & schedule work */
605 		if (!local->ops->remain_on_channel) {
606 			list_add_tail(&roc->list, &local->roc_list);
607 			ieee80211_queue_delayed_work(&local->hw,
608 						     &local->roc_work, 0);
609 		} else {
610 			/* otherwise actually kick it off here
611 			 * (for error handling)
612 			 */
613 			ret = drv_remain_on_channel(local, sdata, channel,
614 						    duration, type);
615 			if (ret) {
616 				kfree(roc);
617 				return ret;
618 			}
619 			roc->started = true;
620 			list_add_tail(&roc->list, &local->roc_list);
621 		}
622 
623 		return 0;
624 	}
625 
626 	/* otherwise handle queueing */
627 
628 	list_for_each_entry(tmp, &local->roc_list, list) {
629 		if (tmp->chan != channel || tmp->sdata != sdata)
630 			continue;
631 
632 		/*
633 		 * Extend this ROC if possible: If it hasn't started, add
634 		 * just after the new one to combine.
635 		 */
636 		if (!tmp->started) {
637 			list_add(&roc->list, &tmp->list);
638 			queued = true;
639 			break;
640 		}
641 
642 		if (!combine_started)
643 			continue;
644 
645 		if (!local->ops->remain_on_channel) {
646 			/* If there's no hardware remain-on-channel, and
647 			 * doing so won't push us over the maximum r-o-c
648 			 * we allow, then we can just add the new one to
649 			 * the list and mark it as having started now.
650 			 * If it would push over the limit, don't try to
651 			 * combine with other started ones (that haven't
652 			 * been running as long) but potentially sort it
653 			 * with others that had the same fate.
654 			 */
655 			unsigned long now = jiffies;
656 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
657 			struct wiphy *wiphy = local->hw.wiphy;
658 			u32 max_roc = wiphy->max_remain_on_channel_duration;
659 
660 			if (elapsed + roc->duration > max_roc) {
661 				combine_started = false;
662 				continue;
663 			}
664 
665 			list_add(&roc->list, &tmp->list);
666 			queued = true;
667 			roc->on_channel = tmp->on_channel;
668 			ieee80211_handle_roc_started(roc, now);
669 			ieee80211_recalc_sw_work(local, now);
670 			break;
671 		}
672 
673 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
674 		if (queued)
675 			break;
676 		/* if it wasn't queued, perhaps it can be combined with
677 		 * another that also couldn't get combined previously,
678 		 * but no need to check for already started ones, since
679 		 * that can't work.
680 		 */
681 		combine_started = false;
682 	}
683 
684 	if (!queued)
685 		list_add_tail(&roc->list, &local->roc_list);
686 
687 	return 0;
688 }
689 
690 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
691 				struct ieee80211_channel *chan,
692 				unsigned int duration, u64 *cookie)
693 {
694 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
695 	struct ieee80211_local *local = sdata->local;
696 	int ret;
697 
698 	mutex_lock(&local->mtx);
699 	ret = ieee80211_start_roc_work(local, sdata, chan,
700 				       duration, cookie, NULL,
701 				       IEEE80211_ROC_TYPE_NORMAL);
702 	mutex_unlock(&local->mtx);
703 
704 	return ret;
705 }
706 
707 static int ieee80211_cancel_roc(struct ieee80211_local *local,
708 				u64 cookie, bool mgmt_tx)
709 {
710 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
711 	int ret;
712 
713 	if (!cookie)
714 		return -ENOENT;
715 
716 	flush_work(&local->hw_roc_start);
717 
718 	mutex_lock(&local->mtx);
719 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
720 		if (!mgmt_tx && roc->cookie != cookie)
721 			continue;
722 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
723 			continue;
724 
725 		found = roc;
726 		break;
727 	}
728 
729 	if (!found) {
730 		mutex_unlock(&local->mtx);
731 		return -ENOENT;
732 	}
733 
734 	if (!found->started) {
735 		ieee80211_roc_notify_destroy(found);
736 		goto out_unlock;
737 	}
738 
739 	if (local->ops->remain_on_channel) {
740 		ret = drv_cancel_remain_on_channel(local, roc->sdata);
741 		if (WARN_ON_ONCE(ret)) {
742 			mutex_unlock(&local->mtx);
743 			return ret;
744 		}
745 
746 		/* TODO:
747 		 * if multiple items were combined here then we really shouldn't
748 		 * cancel them all - we should wait for as much time as needed
749 		 * for the longest remaining one, and only then cancel ...
750 		 */
751 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
752 			if (!roc->started)
753 				break;
754 			if (roc == found)
755 				found = NULL;
756 			ieee80211_roc_notify_destroy(roc);
757 		}
758 
759 		/* that really must not happen - it was started */
760 		WARN_ON(found);
761 
762 		ieee80211_start_next_roc(local);
763 	} else {
764 		/* go through work struct to return to the operating channel */
765 		found->abort = true;
766 		mod_delayed_work(local->workqueue, &local->roc_work, 0);
767 	}
768 
769  out_unlock:
770 	mutex_unlock(&local->mtx);
771 
772 	return 0;
773 }
774 
775 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
776 				       struct wireless_dev *wdev, u64 cookie)
777 {
778 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
779 	struct ieee80211_local *local = sdata->local;
780 
781 	return ieee80211_cancel_roc(local, cookie, false);
782 }
783 
784 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
785 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
786 {
787 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
788 	struct ieee80211_local *local = sdata->local;
789 	struct sk_buff *skb;
790 	struct sta_info *sta;
791 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
792 	bool need_offchan = false;
793 	u32 flags;
794 	int ret;
795 	u8 *data;
796 
797 	if (params->dont_wait_for_ack)
798 		flags = IEEE80211_TX_CTL_NO_ACK;
799 	else
800 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
801 			IEEE80211_TX_CTL_REQ_TX_STATUS;
802 
803 	if (params->no_cck)
804 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
805 
806 	switch (sdata->vif.type) {
807 	case NL80211_IFTYPE_ADHOC:
808 		if (!sdata->vif.bss_conf.ibss_joined)
809 			need_offchan = true;
810 #ifdef CONFIG_MAC80211_MESH
811 		fallthrough;
812 	case NL80211_IFTYPE_MESH_POINT:
813 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
814 		    !sdata->u.mesh.mesh_id_len)
815 			need_offchan = true;
816 #endif
817 		fallthrough;
818 	case NL80211_IFTYPE_AP:
819 	case NL80211_IFTYPE_AP_VLAN:
820 	case NL80211_IFTYPE_P2P_GO:
821 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
822 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
823 		    !rcu_access_pointer(sdata->bss->beacon))
824 			need_offchan = true;
825 		if (!ieee80211_is_action(mgmt->frame_control) ||
826 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
827 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
828 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
829 			break;
830 		rcu_read_lock();
831 		sta = sta_info_get_bss(sdata, mgmt->da);
832 		rcu_read_unlock();
833 		if (!sta)
834 			return -ENOLINK;
835 		break;
836 	case NL80211_IFTYPE_STATION:
837 	case NL80211_IFTYPE_P2P_CLIENT:
838 		sdata_lock(sdata);
839 		if (!sdata->u.mgd.associated ||
840 		    (params->offchan && params->wait &&
841 		     local->ops->remain_on_channel &&
842 		     memcmp(sdata->u.mgd.associated->bssid,
843 			    mgmt->bssid, ETH_ALEN)))
844 			need_offchan = true;
845 		sdata_unlock(sdata);
846 		break;
847 	case NL80211_IFTYPE_P2P_DEVICE:
848 		need_offchan = true;
849 		break;
850 	case NL80211_IFTYPE_NAN:
851 	default:
852 		return -EOPNOTSUPP;
853 	}
854 
855 	/* configurations requiring offchan cannot work if no channel has been
856 	 * specified
857 	 */
858 	if (need_offchan && !params->chan)
859 		return -EINVAL;
860 
861 	mutex_lock(&local->mtx);
862 
863 	/* Check if the operating channel is the requested channel */
864 	if (!need_offchan) {
865 		struct ieee80211_chanctx_conf *chanctx_conf;
866 
867 		rcu_read_lock();
868 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
869 
870 		if (chanctx_conf) {
871 			need_offchan = params->chan &&
872 				       (params->chan !=
873 					chanctx_conf->def.chan);
874 		} else if (!params->chan) {
875 			ret = -EINVAL;
876 			rcu_read_unlock();
877 			goto out_unlock;
878 		} else {
879 			need_offchan = true;
880 		}
881 		rcu_read_unlock();
882 	}
883 
884 	if (need_offchan && !params->offchan) {
885 		ret = -EBUSY;
886 		goto out_unlock;
887 	}
888 
889 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
890 	if (!skb) {
891 		ret = -ENOMEM;
892 		goto out_unlock;
893 	}
894 	skb_reserve(skb, local->hw.extra_tx_headroom);
895 
896 	data = skb_put_data(skb, params->buf, params->len);
897 
898 	/* Update CSA counters */
899 	if (sdata->vif.csa_active &&
900 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
901 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
902 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
903 	    params->n_csa_offsets) {
904 		int i;
905 		struct beacon_data *beacon = NULL;
906 
907 		rcu_read_lock();
908 
909 		if (sdata->vif.type == NL80211_IFTYPE_AP)
910 			beacon = rcu_dereference(sdata->u.ap.beacon);
911 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
912 			beacon = rcu_dereference(sdata->u.ibss.presp);
913 		else if (ieee80211_vif_is_mesh(&sdata->vif))
914 			beacon = rcu_dereference(sdata->u.mesh.beacon);
915 
916 		if (beacon)
917 			for (i = 0; i < params->n_csa_offsets; i++)
918 				data[params->csa_offsets[i]] =
919 					beacon->csa_current_counter;
920 
921 		rcu_read_unlock();
922 	}
923 
924 	IEEE80211_SKB_CB(skb)->flags = flags;
925 
926 	skb->dev = sdata->dev;
927 
928 	if (!params->dont_wait_for_ack) {
929 		/* make a copy to preserve the frame contents
930 		 * in case of encryption.
931 		 */
932 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
933 		if (ret) {
934 			kfree_skb(skb);
935 			goto out_unlock;
936 		}
937 	} else {
938 		/* Assign a dummy non-zero cookie, it's not sent to
939 		 * userspace in this case but we rely on its value
940 		 * internally in the need_offchan case to distinguish
941 		 * mgmt-tx from remain-on-channel.
942 		 */
943 		*cookie = 0xffffffff;
944 	}
945 
946 	if (!need_offchan) {
947 		ieee80211_tx_skb(sdata, skb);
948 		ret = 0;
949 		goto out_unlock;
950 	}
951 
952 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
953 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
954 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
955 		IEEE80211_SKB_CB(skb)->hw_queue =
956 			local->hw.offchannel_tx_hw_queue;
957 
958 	/* This will handle all kinds of coalescing and immediate TX */
959 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
960 				       params->wait, cookie, skb,
961 				       IEEE80211_ROC_TYPE_MGMT_TX);
962 	if (ret)
963 		ieee80211_free_txskb(&local->hw, skb);
964  out_unlock:
965 	mutex_unlock(&local->mtx);
966 	return ret;
967 }
968 
969 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
970 				  struct wireless_dev *wdev, u64 cookie)
971 {
972 	struct ieee80211_local *local = wiphy_priv(wiphy);
973 
974 	return ieee80211_cancel_roc(local, cookie, true);
975 }
976 
977 void ieee80211_roc_setup(struct ieee80211_local *local)
978 {
979 	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
980 	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
981 	INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
982 	INIT_LIST_HEAD(&local->roc_list);
983 }
984 
985 void ieee80211_roc_purge(struct ieee80211_local *local,
986 			 struct ieee80211_sub_if_data *sdata)
987 {
988 	struct ieee80211_roc_work *roc, *tmp;
989 	bool work_to_do = false;
990 
991 	mutex_lock(&local->mtx);
992 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
993 		if (sdata && roc->sdata != sdata)
994 			continue;
995 
996 		if (roc->started) {
997 			if (local->ops->remain_on_channel) {
998 				/* can race, so ignore return value */
999 				drv_cancel_remain_on_channel(local, sdata);
1000 				ieee80211_roc_notify_destroy(roc);
1001 			} else {
1002 				roc->abort = true;
1003 				work_to_do = true;
1004 			}
1005 		} else {
1006 			ieee80211_roc_notify_destroy(roc);
1007 		}
1008 	}
1009 	if (work_to_do)
1010 		__ieee80211_roc_work(local);
1011 	mutex_unlock(&local->mtx);
1012 }
1013