xref: /openbmc/linux/net/mac80211/offchannel.c (revision e7253313)
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, 0);
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 (local->use_chanctx && !local->ops->remain_on_channel)
561 		return -EOPNOTSUPP;
562 
563 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
564 	if (!roc)
565 		return -ENOMEM;
566 
567 	/*
568 	 * If the duration is zero, then the driver
569 	 * wouldn't actually do anything. Set it to
570 	 * 10 for now.
571 	 *
572 	 * TODO: cancel the off-channel operation
573 	 *       when we get the SKB's TX status and
574 	 *       the wait time was zero before.
575 	 */
576 	if (!duration)
577 		duration = 10;
578 
579 	roc->chan = channel;
580 	roc->duration = duration;
581 	roc->req_duration = duration;
582 	roc->frame = txskb;
583 	roc->type = type;
584 	roc->sdata = sdata;
585 
586 	/*
587 	 * cookie is either the roc cookie (for normal roc)
588 	 * or the SKB (for mgmt TX)
589 	 */
590 	if (!txskb) {
591 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
592 		*cookie = roc->cookie;
593 	} else {
594 		roc->mgmt_tx_cookie = *cookie;
595 	}
596 
597 	/* if there's no need to queue, handle it immediately */
598 	if (list_empty(&local->roc_list) &&
599 	    !local->scanning && !ieee80211_is_radar_required(local)) {
600 		/* if not HW assist, just queue & schedule work */
601 		if (!local->ops->remain_on_channel) {
602 			list_add_tail(&roc->list, &local->roc_list);
603 			ieee80211_queue_delayed_work(&local->hw,
604 						     &local->roc_work, 0);
605 		} else {
606 			/* otherwise actually kick it off here
607 			 * (for error handling)
608 			 */
609 			ret = drv_remain_on_channel(local, sdata, channel,
610 						    duration, type);
611 			if (ret) {
612 				kfree(roc);
613 				return ret;
614 			}
615 			roc->started = true;
616 			list_add_tail(&roc->list, &local->roc_list);
617 		}
618 
619 		return 0;
620 	}
621 
622 	/* otherwise handle queueing */
623 
624 	list_for_each_entry(tmp, &local->roc_list, list) {
625 		if (tmp->chan != channel || tmp->sdata != sdata)
626 			continue;
627 
628 		/*
629 		 * Extend this ROC if possible: If it hasn't started, add
630 		 * just after the new one to combine.
631 		 */
632 		if (!tmp->started) {
633 			list_add(&roc->list, &tmp->list);
634 			queued = true;
635 			break;
636 		}
637 
638 		if (!combine_started)
639 			continue;
640 
641 		if (!local->ops->remain_on_channel) {
642 			/* If there's no hardware remain-on-channel, and
643 			 * doing so won't push us over the maximum r-o-c
644 			 * we allow, then we can just add the new one to
645 			 * the list and mark it as having started now.
646 			 * If it would push over the limit, don't try to
647 			 * combine with other started ones (that haven't
648 			 * been running as long) but potentially sort it
649 			 * with others that had the same fate.
650 			 */
651 			unsigned long now = jiffies;
652 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
653 			struct wiphy *wiphy = local->hw.wiphy;
654 			u32 max_roc = wiphy->max_remain_on_channel_duration;
655 
656 			if (elapsed + roc->duration > max_roc) {
657 				combine_started = false;
658 				continue;
659 			}
660 
661 			list_add(&roc->list, &tmp->list);
662 			queued = true;
663 			roc->on_channel = tmp->on_channel;
664 			ieee80211_handle_roc_started(roc, now);
665 			ieee80211_recalc_sw_work(local, now);
666 			break;
667 		}
668 
669 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
670 		if (queued)
671 			break;
672 		/* if it wasn't queued, perhaps it can be combined with
673 		 * another that also couldn't get combined previously,
674 		 * but no need to check for already started ones, since
675 		 * that can't work.
676 		 */
677 		combine_started = false;
678 	}
679 
680 	if (!queued)
681 		list_add_tail(&roc->list, &local->roc_list);
682 
683 	return 0;
684 }
685 
686 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
687 				struct ieee80211_channel *chan,
688 				unsigned int duration, u64 *cookie)
689 {
690 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
691 	struct ieee80211_local *local = sdata->local;
692 	int ret;
693 
694 	mutex_lock(&local->mtx);
695 	ret = ieee80211_start_roc_work(local, sdata, chan,
696 				       duration, cookie, NULL,
697 				       IEEE80211_ROC_TYPE_NORMAL);
698 	mutex_unlock(&local->mtx);
699 
700 	return ret;
701 }
702 
703 static int ieee80211_cancel_roc(struct ieee80211_local *local,
704 				u64 cookie, bool mgmt_tx)
705 {
706 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
707 	int ret;
708 
709 	if (!cookie)
710 		return -ENOENT;
711 
712 	flush_work(&local->hw_roc_start);
713 
714 	mutex_lock(&local->mtx);
715 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
716 		if (!mgmt_tx && roc->cookie != cookie)
717 			continue;
718 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
719 			continue;
720 
721 		found = roc;
722 		break;
723 	}
724 
725 	if (!found) {
726 		mutex_unlock(&local->mtx);
727 		return -ENOENT;
728 	}
729 
730 	if (!found->started) {
731 		ieee80211_roc_notify_destroy(found);
732 		goto out_unlock;
733 	}
734 
735 	if (local->ops->remain_on_channel) {
736 		ret = drv_cancel_remain_on_channel(local, roc->sdata);
737 		if (WARN_ON_ONCE(ret)) {
738 			mutex_unlock(&local->mtx);
739 			return ret;
740 		}
741 
742 		/* TODO:
743 		 * if multiple items were combined here then we really shouldn't
744 		 * cancel them all - we should wait for as much time as needed
745 		 * for the longest remaining one, and only then cancel ...
746 		 */
747 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
748 			if (!roc->started)
749 				break;
750 			if (roc == found)
751 				found = NULL;
752 			ieee80211_roc_notify_destroy(roc);
753 		}
754 
755 		/* that really must not happen - it was started */
756 		WARN_ON(found);
757 
758 		ieee80211_start_next_roc(local);
759 	} else {
760 		/* go through work struct to return to the operating channel */
761 		found->abort = true;
762 		mod_delayed_work(local->workqueue, &local->roc_work, 0);
763 	}
764 
765  out_unlock:
766 	mutex_unlock(&local->mtx);
767 
768 	return 0;
769 }
770 
771 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
772 				       struct wireless_dev *wdev, u64 cookie)
773 {
774 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
775 	struct ieee80211_local *local = sdata->local;
776 
777 	return ieee80211_cancel_roc(local, cookie, false);
778 }
779 
780 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
781 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
782 {
783 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
784 	struct ieee80211_local *local = sdata->local;
785 	struct sk_buff *skb;
786 	struct sta_info *sta;
787 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
788 	bool need_offchan = false;
789 	u32 flags;
790 	int ret;
791 	u8 *data;
792 
793 	if (params->dont_wait_for_ack)
794 		flags = IEEE80211_TX_CTL_NO_ACK;
795 	else
796 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
797 			IEEE80211_TX_CTL_REQ_TX_STATUS;
798 
799 	if (params->no_cck)
800 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
801 
802 	switch (sdata->vif.type) {
803 	case NL80211_IFTYPE_ADHOC:
804 		if (!sdata->vif.bss_conf.ibss_joined)
805 			need_offchan = true;
806 #ifdef CONFIG_MAC80211_MESH
807 		/* fall through */
808 	case NL80211_IFTYPE_MESH_POINT:
809 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
810 		    !sdata->u.mesh.mesh_id_len)
811 			need_offchan = true;
812 #endif
813 		/* fall through */
814 	case NL80211_IFTYPE_AP:
815 	case NL80211_IFTYPE_AP_VLAN:
816 	case NL80211_IFTYPE_P2P_GO:
817 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
818 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
819 		    !rcu_access_pointer(sdata->bss->beacon))
820 			need_offchan = true;
821 		if (!ieee80211_is_action(mgmt->frame_control) ||
822 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
823 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
824 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
825 			break;
826 		rcu_read_lock();
827 		sta = sta_info_get_bss(sdata, mgmt->da);
828 		rcu_read_unlock();
829 		if (!sta)
830 			return -ENOLINK;
831 		break;
832 	case NL80211_IFTYPE_STATION:
833 	case NL80211_IFTYPE_P2P_CLIENT:
834 		sdata_lock(sdata);
835 		if (!sdata->u.mgd.associated ||
836 		    (params->offchan && params->wait &&
837 		     local->ops->remain_on_channel &&
838 		     memcmp(sdata->u.mgd.associated->bssid,
839 			    mgmt->bssid, ETH_ALEN)))
840 			need_offchan = true;
841 		sdata_unlock(sdata);
842 		break;
843 	case NL80211_IFTYPE_P2P_DEVICE:
844 		need_offchan = true;
845 		break;
846 	case NL80211_IFTYPE_NAN:
847 	default:
848 		return -EOPNOTSUPP;
849 	}
850 
851 	/* configurations requiring offchan cannot work if no channel has been
852 	 * specified
853 	 */
854 	if (need_offchan && !params->chan)
855 		return -EINVAL;
856 
857 	mutex_lock(&local->mtx);
858 
859 	/* Check if the operating channel is the requested channel */
860 	if (!need_offchan) {
861 		struct ieee80211_chanctx_conf *chanctx_conf;
862 
863 		rcu_read_lock();
864 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
865 
866 		if (chanctx_conf) {
867 			need_offchan = params->chan &&
868 				       (params->chan !=
869 					chanctx_conf->def.chan);
870 		} else if (!params->chan) {
871 			ret = -EINVAL;
872 			rcu_read_unlock();
873 			goto out_unlock;
874 		} else {
875 			need_offchan = true;
876 		}
877 		rcu_read_unlock();
878 	}
879 
880 	if (need_offchan && !params->offchan) {
881 		ret = -EBUSY;
882 		goto out_unlock;
883 	}
884 
885 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
886 	if (!skb) {
887 		ret = -ENOMEM;
888 		goto out_unlock;
889 	}
890 	skb_reserve(skb, local->hw.extra_tx_headroom);
891 
892 	data = skb_put_data(skb, params->buf, params->len);
893 
894 	/* Update CSA counters */
895 	if (sdata->vif.csa_active &&
896 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
897 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
898 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
899 	    params->n_csa_offsets) {
900 		int i;
901 		struct beacon_data *beacon = NULL;
902 
903 		rcu_read_lock();
904 
905 		if (sdata->vif.type == NL80211_IFTYPE_AP)
906 			beacon = rcu_dereference(sdata->u.ap.beacon);
907 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
908 			beacon = rcu_dereference(sdata->u.ibss.presp);
909 		else if (ieee80211_vif_is_mesh(&sdata->vif))
910 			beacon = rcu_dereference(sdata->u.mesh.beacon);
911 
912 		if (beacon)
913 			for (i = 0; i < params->n_csa_offsets; i++)
914 				data[params->csa_offsets[i]] =
915 					beacon->csa_current_counter;
916 
917 		rcu_read_unlock();
918 	}
919 
920 	IEEE80211_SKB_CB(skb)->flags = flags;
921 
922 	skb->dev = sdata->dev;
923 
924 	if (!params->dont_wait_for_ack) {
925 		/* make a copy to preserve the frame contents
926 		 * in case of encryption.
927 		 */
928 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
929 		if (ret) {
930 			kfree_skb(skb);
931 			goto out_unlock;
932 		}
933 	} else {
934 		/* Assign a dummy non-zero cookie, it's not sent to
935 		 * userspace in this case but we rely on its value
936 		 * internally in the need_offchan case to distinguish
937 		 * mgmt-tx from remain-on-channel.
938 		 */
939 		*cookie = 0xffffffff;
940 	}
941 
942 	if (!need_offchan) {
943 		ieee80211_tx_skb(sdata, skb);
944 		ret = 0;
945 		goto out_unlock;
946 	}
947 
948 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
949 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
950 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
951 		IEEE80211_SKB_CB(skb)->hw_queue =
952 			local->hw.offchannel_tx_hw_queue;
953 
954 	/* This will handle all kinds of coalescing and immediate TX */
955 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
956 				       params->wait, cookie, skb,
957 				       IEEE80211_ROC_TYPE_MGMT_TX);
958 	if (ret)
959 		ieee80211_free_txskb(&local->hw, skb);
960  out_unlock:
961 	mutex_unlock(&local->mtx);
962 	return ret;
963 }
964 
965 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
966 				  struct wireless_dev *wdev, u64 cookie)
967 {
968 	struct ieee80211_local *local = wiphy_priv(wiphy);
969 
970 	return ieee80211_cancel_roc(local, cookie, true);
971 }
972 
973 void ieee80211_roc_setup(struct ieee80211_local *local)
974 {
975 	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
976 	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
977 	INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
978 	INIT_LIST_HEAD(&local->roc_list);
979 }
980 
981 void ieee80211_roc_purge(struct ieee80211_local *local,
982 			 struct ieee80211_sub_if_data *sdata)
983 {
984 	struct ieee80211_roc_work *roc, *tmp;
985 	bool work_to_do = false;
986 
987 	mutex_lock(&local->mtx);
988 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
989 		if (sdata && roc->sdata != sdata)
990 			continue;
991 
992 		if (roc->started) {
993 			if (local->ops->remain_on_channel) {
994 				/* can race, so ignore return value */
995 				drv_cancel_remain_on_channel(local, sdata);
996 				ieee80211_roc_notify_destroy(roc);
997 			} else {
998 				roc->abort = true;
999 				work_to_do = true;
1000 			}
1001 		} else {
1002 			ieee80211_roc_notify_destroy(roc);
1003 		}
1004 	}
1005 	if (work_to_do)
1006 		__ieee80211_roc_work(local);
1007 	mutex_unlock(&local->mtx);
1008 }
1009