xref: /linux/net/mac80211/offchannel.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * Off-channel operation helpers
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2004, Instant802 Networks, Inc.
6  * Copyright 2005, Devicescape Software, Inc.
7  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 #include <linux/export.h>
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "driver-ops.h"
19 
20 /*
21  * Tell our hardware to disable PS.
22  * Optionally inform AP that we will go to sleep so that it will buffer
23  * the frames while we are doing off-channel work.  This is optional
24  * because we *may* be doing work on-operating channel, and want our
25  * hardware unconditionally awake, but still let the AP send us normal frames.
26  */
27 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
28 {
29 	struct ieee80211_local *local = sdata->local;
30 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
31 
32 	local->offchannel_ps_enabled = false;
33 
34 	/* FIXME: what to do when local->pspolling is true? */
35 
36 	del_timer_sync(&local->dynamic_ps_timer);
37 	del_timer_sync(&ifmgd->bcn_mon_timer);
38 	del_timer_sync(&ifmgd->conn_mon_timer);
39 
40 	cancel_work_sync(&local->dynamic_ps_enable_work);
41 
42 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
43 		local->offchannel_ps_enabled = true;
44 		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
45 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
46 	}
47 
48 	if (!local->offchannel_ps_enabled ||
49 	    !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
50 		/*
51 		 * If power save was enabled, no need to send a nullfunc
52 		 * frame because AP knows that we are sleeping. But if the
53 		 * hardware is creating the nullfunc frame for power save
54 		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
55 		 * enabled) and power save was enabled, the firmware just
56 		 * sent a null frame with power save disabled. So we need
57 		 * to send a new nullfunc frame to inform the AP that we
58 		 * are again sleeping.
59 		 */
60 		ieee80211_send_nullfunc(local, sdata, true);
61 }
62 
63 /* inform AP that we are awake again, unless power save is enabled */
64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
65 {
66 	struct ieee80211_local *local = sdata->local;
67 
68 	if (!local->ps_sdata)
69 		ieee80211_send_nullfunc(local, sdata, false);
70 	else if (local->offchannel_ps_enabled) {
71 		/*
72 		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
73 		 * will send a nullfunc frame with the powersave bit set
74 		 * even though the AP already knows that we are sleeping.
75 		 * This could be avoided by sending a null frame with power
76 		 * save bit disabled before enabling the power save, but
77 		 * this doesn't gain anything.
78 		 *
79 		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
80 		 * to send a nullfunc frame because AP already knows that
81 		 * we are sleeping, let's just enable power save mode in
82 		 * hardware.
83 		 */
84 		/* TODO:  Only set hardware if CONF_PS changed?
85 		 * TODO:  Should we set offchannel_ps_enabled to false?
86 		 */
87 		local->hw.conf.flags |= IEEE80211_CONF_PS;
88 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
89 	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
90 		/*
91 		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
92 		 * had been running before leaving the operating channel,
93 		 * restart the timer now and send a nullfunc frame to inform
94 		 * the AP that we are awake.
95 		 */
96 		ieee80211_send_nullfunc(local, sdata, false);
97 		mod_timer(&local->dynamic_ps_timer, jiffies +
98 			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
99 	}
100 
101 	ieee80211_sta_reset_beacon_monitor(sdata);
102 	ieee80211_sta_reset_conn_monitor(sdata);
103 }
104 
105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
106 {
107 	struct ieee80211_sub_if_data *sdata;
108 
109 	if (WARN_ON(local->use_chanctx))
110 		return;
111 
112 	/*
113 	 * notify the AP about us leaving the channel and stop all
114 	 * STA interfaces.
115 	 */
116 
117 	/*
118 	 * Stop queues and transmit all frames queued by the driver
119 	 * before sending nullfunc to enable powersave at the AP.
120 	 */
121 	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
122 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
123 					false);
124 	ieee80211_flush_queues(local, NULL, false);
125 
126 	mutex_lock(&local->iflist_mtx);
127 	list_for_each_entry(sdata, &local->interfaces, list) {
128 		if (!ieee80211_sdata_running(sdata))
129 			continue;
130 
131 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
132 		    sdata->vif.type == NL80211_IFTYPE_NAN)
133 			continue;
134 
135 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
136 			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
137 
138 		/* Check to see if we should disable beaconing. */
139 		if (sdata->vif.bss_conf.enable_beacon) {
140 			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
141 				&sdata->state);
142 			sdata->vif.bss_conf.enable_beacon = false;
143 			ieee80211_bss_info_change_notify(
144 				sdata, BSS_CHANGED_BEACON_ENABLED);
145 		}
146 
147 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
148 		    sdata->u.mgd.associated)
149 			ieee80211_offchannel_ps_enable(sdata);
150 	}
151 	mutex_unlock(&local->iflist_mtx);
152 }
153 
154 void ieee80211_offchannel_return(struct ieee80211_local *local)
155 {
156 	struct ieee80211_sub_if_data *sdata;
157 
158 	if (WARN_ON(local->use_chanctx))
159 		return;
160 
161 	mutex_lock(&local->iflist_mtx);
162 	list_for_each_entry(sdata, &local->interfaces, list) {
163 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
164 			continue;
165 
166 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
167 			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
168 
169 		if (!ieee80211_sdata_running(sdata))
170 			continue;
171 
172 		/* Tell AP we're back */
173 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
174 		    sdata->u.mgd.associated)
175 			ieee80211_offchannel_ps_disable(sdata);
176 
177 		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
178 				       &sdata->state)) {
179 			sdata->vif.bss_conf.enable_beacon = true;
180 			ieee80211_bss_info_change_notify(
181 				sdata, BSS_CHANGED_BEACON_ENABLED);
182 		}
183 	}
184 	mutex_unlock(&local->iflist_mtx);
185 
186 	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
187 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
188 					false);
189 }
190 
191 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
192 {
193 	/* was never transmitted */
194 	if (roc->frame) {
195 		cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
196 					roc->frame->data, roc->frame->len,
197 					false, GFP_KERNEL);
198 		ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
199 	}
200 
201 	if (!roc->mgmt_tx_cookie)
202 		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
203 						   roc->cookie, roc->chan,
204 						   GFP_KERNEL);
205 
206 	list_del(&roc->list);
207 	kfree(roc);
208 }
209 
210 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
211 						 unsigned long now)
212 {
213 	struct ieee80211_roc_work *roc, *tmp;
214 	long remaining_dur_min = LONG_MAX;
215 
216 	lockdep_assert_held(&local->mtx);
217 
218 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
219 		long remaining;
220 
221 		if (!roc->started)
222 			break;
223 
224 		remaining = roc->start_time +
225 			    msecs_to_jiffies(roc->duration) -
226 			    now;
227 
228 		/* In case of HW ROC, it is possible that the HW finished the
229 		 * ROC session before the actual requested time. In such a case
230 		 * end the ROC session (disregarding the remaining time).
231 		 */
232 		if (roc->abort || roc->hw_begun || remaining <= 0)
233 			ieee80211_roc_notify_destroy(roc);
234 		else
235 			remaining_dur_min = min(remaining_dur_min, remaining);
236 	}
237 
238 	return remaining_dur_min;
239 }
240 
241 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
242 				     unsigned long now)
243 {
244 	long dur = ieee80211_end_finished_rocs(local, now);
245 
246 	if (dur == LONG_MAX)
247 		return false;
248 
249 	mod_delayed_work(local->workqueue, &local->roc_work, dur);
250 	return true;
251 }
252 
253 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
254 					 unsigned long start_time)
255 {
256 	if (WARN_ON(roc->notified))
257 		return;
258 
259 	roc->start_time = start_time;
260 	roc->started = true;
261 
262 	if (roc->mgmt_tx_cookie) {
263 		if (!WARN_ON(!roc->frame)) {
264 			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
265 						  roc->chan->band);
266 			roc->frame = NULL;
267 		}
268 	} else {
269 		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
270 					  roc->chan, roc->req_duration,
271 					  GFP_KERNEL);
272 	}
273 
274 	roc->notified = true;
275 }
276 
277 static void ieee80211_hw_roc_start(struct work_struct *work)
278 {
279 	struct ieee80211_local *local =
280 		container_of(work, struct ieee80211_local, hw_roc_start);
281 	struct ieee80211_roc_work *roc;
282 
283 	mutex_lock(&local->mtx);
284 
285 	list_for_each_entry(roc, &local->roc_list, list) {
286 		if (!roc->started)
287 			break;
288 
289 		roc->hw_begun = true;
290 		ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
291 	}
292 
293 	mutex_unlock(&local->mtx);
294 }
295 
296 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
297 {
298 	struct ieee80211_local *local = hw_to_local(hw);
299 
300 	local->hw_roc_start_time = jiffies;
301 
302 	trace_api_ready_on_channel(local);
303 
304 	ieee80211_queue_work(hw, &local->hw_roc_start);
305 }
306 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
307 
308 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
309 {
310 	struct ieee80211_roc_work *roc, *tmp;
311 	enum ieee80211_roc_type type;
312 	u32 min_dur, max_dur;
313 
314 	lockdep_assert_held(&local->mtx);
315 
316 	if (WARN_ON(list_empty(&local->roc_list)))
317 		return;
318 
319 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
320 			       list);
321 
322 	if (WARN_ON(roc->started))
323 		return;
324 
325 	min_dur = roc->duration;
326 	max_dur = roc->duration;
327 	type = roc->type;
328 
329 	list_for_each_entry(tmp, &local->roc_list, list) {
330 		if (tmp == roc)
331 			continue;
332 		if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
333 			break;
334 		max_dur = max(tmp->duration, max_dur);
335 		min_dur = min(tmp->duration, min_dur);
336 		type = max(tmp->type, type);
337 	}
338 
339 	if (local->ops->remain_on_channel) {
340 		int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
341 						max_dur, type);
342 
343 		if (ret) {
344 			wiphy_warn(local->hw.wiphy,
345 				   "failed to start next HW ROC (%d)\n", ret);
346 			/*
347 			 * queue the work struct again to avoid recursion
348 			 * when multiple failures occur
349 			 */
350 			list_for_each_entry(tmp, &local->roc_list, list) {
351 				if (tmp->sdata != roc->sdata ||
352 				    tmp->chan != roc->chan)
353 					break;
354 				tmp->started = true;
355 				tmp->abort = true;
356 			}
357 			ieee80211_queue_work(&local->hw, &local->hw_roc_done);
358 			return;
359 		}
360 
361 		/* we'll notify about the start once the HW calls back */
362 		list_for_each_entry(tmp, &local->roc_list, list) {
363 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
364 				break;
365 			tmp->started = true;
366 		}
367 	} else {
368 		/* If actually operating on the desired channel (with at least
369 		 * 20 MHz channel width) don't stop all the operations but still
370 		 * treat it as though the ROC operation started properly, so
371 		 * other ROC operations won't interfere with this one.
372 		 */
373 		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
374 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
375 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
376 
377 		/* start this ROC */
378 		ieee80211_recalc_idle(local);
379 
380 		if (!roc->on_channel) {
381 			ieee80211_offchannel_stop_vifs(local);
382 
383 			local->tmp_channel = roc->chan;
384 			ieee80211_hw_config(local, 0);
385 		}
386 
387 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
388 					     msecs_to_jiffies(min_dur));
389 
390 		/* tell userspace or send frame(s) */
391 		list_for_each_entry(tmp, &local->roc_list, list) {
392 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
393 				break;
394 
395 			tmp->on_channel = roc->on_channel;
396 			ieee80211_handle_roc_started(tmp, jiffies);
397 		}
398 	}
399 }
400 
401 void ieee80211_start_next_roc(struct ieee80211_local *local)
402 {
403 	struct ieee80211_roc_work *roc;
404 
405 	lockdep_assert_held(&local->mtx);
406 
407 	if (list_empty(&local->roc_list)) {
408 		ieee80211_run_deferred_scan(local);
409 		return;
410 	}
411 
412 	/* defer roc if driver is not started (i.e. during reconfig) */
413 	if (local->in_reconfig)
414 		return;
415 
416 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
417 			       list);
418 
419 	if (WARN_ON_ONCE(roc->started))
420 		return;
421 
422 	if (local->ops->remain_on_channel) {
423 		_ieee80211_start_next_roc(local);
424 	} else {
425 		/* delay it a bit */
426 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
427 					     round_jiffies_relative(HZ/2));
428 	}
429 }
430 
431 static void __ieee80211_roc_work(struct ieee80211_local *local)
432 {
433 	struct ieee80211_roc_work *roc;
434 	bool on_channel;
435 
436 	lockdep_assert_held(&local->mtx);
437 
438 	if (WARN_ON(local->ops->remain_on_channel))
439 		return;
440 
441 	roc = list_first_entry_or_null(&local->roc_list,
442 				       struct ieee80211_roc_work, list);
443 	if (!roc)
444 		return;
445 
446 	if (!roc->started) {
447 		WARN_ON(local->use_chanctx);
448 		_ieee80211_start_next_roc(local);
449 	} else {
450 		on_channel = roc->on_channel;
451 		if (ieee80211_recalc_sw_work(local, jiffies))
452 			return;
453 
454 		/* careful - roc pointer became invalid during recalc */
455 
456 		if (!on_channel) {
457 			ieee80211_flush_queues(local, NULL, false);
458 
459 			local->tmp_channel = NULL;
460 			ieee80211_hw_config(local, 0);
461 
462 			ieee80211_offchannel_return(local);
463 		}
464 
465 		ieee80211_recalc_idle(local);
466 		ieee80211_start_next_roc(local);
467 	}
468 }
469 
470 static void ieee80211_roc_work(struct work_struct *work)
471 {
472 	struct ieee80211_local *local =
473 		container_of(work, struct ieee80211_local, roc_work.work);
474 
475 	mutex_lock(&local->mtx);
476 	__ieee80211_roc_work(local);
477 	mutex_unlock(&local->mtx);
478 }
479 
480 static void ieee80211_hw_roc_done(struct work_struct *work)
481 {
482 	struct ieee80211_local *local =
483 		container_of(work, struct ieee80211_local, hw_roc_done);
484 
485 	mutex_lock(&local->mtx);
486 
487 	ieee80211_end_finished_rocs(local, jiffies);
488 
489 	/* if there's another roc, start it now */
490 	ieee80211_start_next_roc(local);
491 
492 	mutex_unlock(&local->mtx);
493 }
494 
495 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
496 {
497 	struct ieee80211_local *local = hw_to_local(hw);
498 
499 	trace_api_remain_on_channel_expired(local);
500 
501 	ieee80211_queue_work(hw, &local->hw_roc_done);
502 }
503 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
504 
505 static bool
506 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
507 				  struct ieee80211_roc_work *new_roc,
508 				  struct ieee80211_roc_work *cur_roc)
509 {
510 	unsigned long now = jiffies;
511 	unsigned long remaining;
512 
513 	if (WARN_ON(!cur_roc->started))
514 		return false;
515 
516 	/* if it was scheduled in the hardware, but not started yet,
517 	 * we can only combine if the older one had a longer duration
518 	 */
519 	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
520 		return false;
521 
522 	remaining = cur_roc->start_time +
523 		    msecs_to_jiffies(cur_roc->duration) -
524 		    now;
525 
526 	/* if it doesn't fit entirely, schedule a new one */
527 	if (new_roc->duration > jiffies_to_msecs(remaining))
528 		return false;
529 
530 	/* add just after the current one so we combine their finish later */
531 	list_add(&new_roc->list, &cur_roc->list);
532 
533 	/* if the existing one has already begun then let this one also
534 	 * begin, otherwise they'll both be marked properly by the work
535 	 * struct that runs once the driver notifies us of the beginning
536 	 */
537 	if (cur_roc->hw_begun) {
538 		new_roc->hw_begun = true;
539 		ieee80211_handle_roc_started(new_roc, now);
540 	}
541 
542 	return true;
543 }
544 
545 static int ieee80211_start_roc_work(struct ieee80211_local *local,
546 				    struct ieee80211_sub_if_data *sdata,
547 				    struct ieee80211_channel *channel,
548 				    unsigned int duration, u64 *cookie,
549 				    struct sk_buff *txskb,
550 				    enum ieee80211_roc_type type)
551 {
552 	struct ieee80211_roc_work *roc, *tmp;
553 	bool queued = false, combine_started = true;
554 	int ret;
555 
556 	lockdep_assert_held(&local->mtx);
557 
558 	if (local->use_chanctx && !local->ops->remain_on_channel)
559 		return -EOPNOTSUPP;
560 
561 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
562 	if (!roc)
563 		return -ENOMEM;
564 
565 	/*
566 	 * If the duration is zero, then the driver
567 	 * wouldn't actually do anything. Set it to
568 	 * 10 for now.
569 	 *
570 	 * TODO: cancel the off-channel operation
571 	 *       when we get the SKB's TX status and
572 	 *       the wait time was zero before.
573 	 */
574 	if (!duration)
575 		duration = 10;
576 
577 	roc->chan = channel;
578 	roc->duration = duration;
579 	roc->req_duration = duration;
580 	roc->frame = txskb;
581 	roc->type = type;
582 	roc->sdata = sdata;
583 
584 	/*
585 	 * cookie is either the roc cookie (for normal roc)
586 	 * or the SKB (for mgmt TX)
587 	 */
588 	if (!txskb) {
589 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
590 		*cookie = roc->cookie;
591 	} else {
592 		roc->mgmt_tx_cookie = *cookie;
593 	}
594 
595 	/* if there's no need to queue, handle it immediately */
596 	if (list_empty(&local->roc_list) &&
597 	    !local->scanning && !ieee80211_is_radar_required(local)) {
598 		/* if not HW assist, just queue & schedule work */
599 		if (!local->ops->remain_on_channel) {
600 			list_add_tail(&roc->list, &local->roc_list);
601 			ieee80211_queue_delayed_work(&local->hw,
602 						     &local->roc_work, 0);
603 		} else {
604 			/* otherwise actually kick it off here
605 			 * (for error handling)
606 			 */
607 			ret = drv_remain_on_channel(local, sdata, channel,
608 						    duration, type);
609 			if (ret) {
610 				kfree(roc);
611 				return ret;
612 			}
613 			roc->started = true;
614 			list_add_tail(&roc->list, &local->roc_list);
615 		}
616 
617 		return 0;
618 	}
619 
620 	/* otherwise handle queueing */
621 
622 	list_for_each_entry(tmp, &local->roc_list, list) {
623 		if (tmp->chan != channel || tmp->sdata != sdata)
624 			continue;
625 
626 		/*
627 		 * Extend this ROC if possible: If it hasn't started, add
628 		 * just after the new one to combine.
629 		 */
630 		if (!tmp->started) {
631 			list_add(&roc->list, &tmp->list);
632 			queued = true;
633 			break;
634 		}
635 
636 		if (!combine_started)
637 			continue;
638 
639 		if (!local->ops->remain_on_channel) {
640 			/* If there's no hardware remain-on-channel, and
641 			 * doing so won't push us over the maximum r-o-c
642 			 * we allow, then we can just add the new one to
643 			 * the list and mark it as having started now.
644 			 * If it would push over the limit, don't try to
645 			 * combine with other started ones (that haven't
646 			 * been running as long) but potentially sort it
647 			 * with others that had the same fate.
648 			 */
649 			unsigned long now = jiffies;
650 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
651 			struct wiphy *wiphy = local->hw.wiphy;
652 			u32 max_roc = wiphy->max_remain_on_channel_duration;
653 
654 			if (elapsed + roc->duration > max_roc) {
655 				combine_started = false;
656 				continue;
657 			}
658 
659 			list_add(&roc->list, &tmp->list);
660 			queued = true;
661 			roc->on_channel = tmp->on_channel;
662 			ieee80211_handle_roc_started(roc, now);
663 			ieee80211_recalc_sw_work(local, now);
664 			break;
665 		}
666 
667 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
668 		if (queued)
669 			break;
670 		/* if it wasn't queued, perhaps it can be combined with
671 		 * another that also couldn't get combined previously,
672 		 * but no need to check for already started ones, since
673 		 * that can't work.
674 		 */
675 		combine_started = false;
676 	}
677 
678 	if (!queued)
679 		list_add_tail(&roc->list, &local->roc_list);
680 
681 	return 0;
682 }
683 
684 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
685 				struct ieee80211_channel *chan,
686 				unsigned int duration, u64 *cookie)
687 {
688 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
689 	struct ieee80211_local *local = sdata->local;
690 	int ret;
691 
692 	mutex_lock(&local->mtx);
693 	ret = ieee80211_start_roc_work(local, sdata, chan,
694 				       duration, cookie, NULL,
695 				       IEEE80211_ROC_TYPE_NORMAL);
696 	mutex_unlock(&local->mtx);
697 
698 	return ret;
699 }
700 
701 static int ieee80211_cancel_roc(struct ieee80211_local *local,
702 				u64 cookie, bool mgmt_tx)
703 {
704 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
705 	int ret;
706 
707 	if (!cookie)
708 		return -ENOENT;
709 
710 	mutex_lock(&local->mtx);
711 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
712 		if (!mgmt_tx && roc->cookie != cookie)
713 			continue;
714 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
715 			continue;
716 
717 		found = roc;
718 		break;
719 	}
720 
721 	if (!found) {
722 		mutex_unlock(&local->mtx);
723 		return -ENOENT;
724 	}
725 
726 	if (!found->started) {
727 		ieee80211_roc_notify_destroy(found);
728 		goto out_unlock;
729 	}
730 
731 	if (local->ops->remain_on_channel) {
732 		ret = drv_cancel_remain_on_channel(local);
733 		if (WARN_ON_ONCE(ret)) {
734 			mutex_unlock(&local->mtx);
735 			return ret;
736 		}
737 
738 		/* TODO:
739 		 * if multiple items were combined here then we really shouldn't
740 		 * cancel them all - we should wait for as much time as needed
741 		 * for the longest remaining one, and only then cancel ...
742 		 */
743 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
744 			if (!roc->started)
745 				break;
746 			if (roc == found)
747 				found = NULL;
748 			ieee80211_roc_notify_destroy(roc);
749 		}
750 
751 		/* that really must not happen - it was started */
752 		WARN_ON(found);
753 
754 		ieee80211_start_next_roc(local);
755 	} else {
756 		/* go through work struct to return to the operating channel */
757 		found->abort = true;
758 		mod_delayed_work(local->workqueue, &local->roc_work, 0);
759 	}
760 
761  out_unlock:
762 	mutex_unlock(&local->mtx);
763 
764 	return 0;
765 }
766 
767 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
768 				       struct wireless_dev *wdev, u64 cookie)
769 {
770 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
771 	struct ieee80211_local *local = sdata->local;
772 
773 	return ieee80211_cancel_roc(local, cookie, false);
774 }
775 
776 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
777 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
778 {
779 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
780 	struct ieee80211_local *local = sdata->local;
781 	struct sk_buff *skb;
782 	struct sta_info *sta;
783 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
784 	bool need_offchan = false;
785 	u32 flags;
786 	int ret;
787 	u8 *data;
788 
789 	if (params->dont_wait_for_ack)
790 		flags = IEEE80211_TX_CTL_NO_ACK;
791 	else
792 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
793 			IEEE80211_TX_CTL_REQ_TX_STATUS;
794 
795 	if (params->no_cck)
796 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
797 
798 	switch (sdata->vif.type) {
799 	case NL80211_IFTYPE_ADHOC:
800 		if (!sdata->vif.bss_conf.ibss_joined)
801 			need_offchan = true;
802 		/* fall through */
803 #ifdef CONFIG_MAC80211_MESH
804 	case NL80211_IFTYPE_MESH_POINT:
805 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
806 		    !sdata->u.mesh.mesh_id_len)
807 			need_offchan = true;
808 		/* fall through */
809 #endif
810 	case NL80211_IFTYPE_AP:
811 	case NL80211_IFTYPE_AP_VLAN:
812 	case NL80211_IFTYPE_P2P_GO:
813 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
814 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
815 		    !rcu_access_pointer(sdata->bss->beacon))
816 			need_offchan = true;
817 		if (!ieee80211_is_action(mgmt->frame_control) ||
818 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
819 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
820 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
821 			break;
822 		rcu_read_lock();
823 		sta = sta_info_get_bss(sdata, mgmt->da);
824 		rcu_read_unlock();
825 		if (!sta)
826 			return -ENOLINK;
827 		break;
828 	case NL80211_IFTYPE_STATION:
829 	case NL80211_IFTYPE_P2P_CLIENT:
830 		sdata_lock(sdata);
831 		if (!sdata->u.mgd.associated ||
832 		    (params->offchan && params->wait &&
833 		     local->ops->remain_on_channel &&
834 		     memcmp(sdata->u.mgd.associated->bssid,
835 			    mgmt->bssid, ETH_ALEN)))
836 			need_offchan = true;
837 		sdata_unlock(sdata);
838 		break;
839 	case NL80211_IFTYPE_P2P_DEVICE:
840 		need_offchan = true;
841 		break;
842 	case NL80211_IFTYPE_NAN:
843 	default:
844 		return -EOPNOTSUPP;
845 	}
846 
847 	/* configurations requiring offchan cannot work if no channel has been
848 	 * specified
849 	 */
850 	if (need_offchan && !params->chan)
851 		return -EINVAL;
852 
853 	mutex_lock(&local->mtx);
854 
855 	/* Check if the operating channel is the requested channel */
856 	if (!need_offchan) {
857 		struct ieee80211_chanctx_conf *chanctx_conf;
858 
859 		rcu_read_lock();
860 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
861 
862 		if (chanctx_conf) {
863 			need_offchan = params->chan &&
864 				       (params->chan !=
865 					chanctx_conf->def.chan);
866 		} else if (!params->chan) {
867 			ret = -EINVAL;
868 			rcu_read_unlock();
869 			goto out_unlock;
870 		} else {
871 			need_offchan = true;
872 		}
873 		rcu_read_unlock();
874 	}
875 
876 	if (need_offchan && !params->offchan) {
877 		ret = -EBUSY;
878 		goto out_unlock;
879 	}
880 
881 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
882 	if (!skb) {
883 		ret = -ENOMEM;
884 		goto out_unlock;
885 	}
886 	skb_reserve(skb, local->hw.extra_tx_headroom);
887 
888 	data = skb_put(skb, params->len);
889 	memcpy(data, params->buf, params->len);
890 
891 	/* Update CSA counters */
892 	if (sdata->vif.csa_active &&
893 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
894 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
895 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
896 	    params->n_csa_offsets) {
897 		int i;
898 		struct beacon_data *beacon = NULL;
899 
900 		rcu_read_lock();
901 
902 		if (sdata->vif.type == NL80211_IFTYPE_AP)
903 			beacon = rcu_dereference(sdata->u.ap.beacon);
904 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
905 			beacon = rcu_dereference(sdata->u.ibss.presp);
906 		else if (ieee80211_vif_is_mesh(&sdata->vif))
907 			beacon = rcu_dereference(sdata->u.mesh.beacon);
908 
909 		if (beacon)
910 			for (i = 0; i < params->n_csa_offsets; i++)
911 				data[params->csa_offsets[i]] =
912 					beacon->csa_current_counter;
913 
914 		rcu_read_unlock();
915 	}
916 
917 	IEEE80211_SKB_CB(skb)->flags = flags;
918 
919 	skb->dev = sdata->dev;
920 
921 	if (!params->dont_wait_for_ack) {
922 		/* make a copy to preserve the frame contents
923 		 * in case of encryption.
924 		 */
925 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
926 		if (ret) {
927 			kfree_skb(skb);
928 			goto out_unlock;
929 		}
930 	} else {
931 		/* Assign a dummy non-zero cookie, it's not sent to
932 		 * userspace in this case but we rely on its value
933 		 * internally in the need_offchan case to distinguish
934 		 * mgmt-tx from remain-on-channel.
935 		 */
936 		*cookie = 0xffffffff;
937 	}
938 
939 	if (!need_offchan) {
940 		ieee80211_tx_skb(sdata, skb);
941 		ret = 0;
942 		goto out_unlock;
943 	}
944 
945 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
946 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
947 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
948 		IEEE80211_SKB_CB(skb)->hw_queue =
949 			local->hw.offchannel_tx_hw_queue;
950 
951 	/* This will handle all kinds of coalescing and immediate TX */
952 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
953 				       params->wait, cookie, skb,
954 				       IEEE80211_ROC_TYPE_MGMT_TX);
955 	if (ret)
956 		ieee80211_free_txskb(&local->hw, skb);
957  out_unlock:
958 	mutex_unlock(&local->mtx);
959 	return ret;
960 }
961 
962 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
963 				  struct wireless_dev *wdev, u64 cookie)
964 {
965 	struct ieee80211_local *local = wiphy_priv(wiphy);
966 
967 	return ieee80211_cancel_roc(local, cookie, true);
968 }
969 
970 void ieee80211_roc_setup(struct ieee80211_local *local)
971 {
972 	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
973 	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
974 	INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
975 	INIT_LIST_HEAD(&local->roc_list);
976 }
977 
978 void ieee80211_roc_purge(struct ieee80211_local *local,
979 			 struct ieee80211_sub_if_data *sdata)
980 {
981 	struct ieee80211_roc_work *roc, *tmp;
982 	bool work_to_do = false;
983 
984 	mutex_lock(&local->mtx);
985 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
986 		if (sdata && roc->sdata != sdata)
987 			continue;
988 
989 		if (roc->started) {
990 			if (local->ops->remain_on_channel) {
991 				/* can race, so ignore return value */
992 				drv_cancel_remain_on_channel(local);
993 				ieee80211_roc_notify_destroy(roc);
994 			} else {
995 				roc->abort = true;
996 				work_to_do = true;
997 			}
998 		} else {
999 			ieee80211_roc_notify_destroy(roc);
1000 		}
1001 	}
1002 	if (work_to_do)
1003 		__ieee80211_roc_work(local);
1004 	mutex_unlock(&local->mtx);
1005 }
1006