xref: /openbmc/linux/net/mac80211/offchannel.c (revision 2127c01b)
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  */
12 #include <linux/export.h>
13 #include <net/mac80211.h>
14 #include "ieee80211_i.h"
15 #include "driver-ops.h"
16 
17 /*
18  * Tell our hardware to disable PS.
19  * Optionally inform AP that we will go to sleep so that it will buffer
20  * the frames while we are doing off-channel work.  This is optional
21  * because we *may* be doing work on-operating channel, and want our
22  * hardware unconditionally awake, but still let the AP send us normal frames.
23  */
24 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
25 {
26 	struct ieee80211_local *local = sdata->local;
27 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
28 
29 	local->offchannel_ps_enabled = false;
30 
31 	/* FIXME: what to do when local->pspolling is true? */
32 
33 	del_timer_sync(&local->dynamic_ps_timer);
34 	del_timer_sync(&ifmgd->bcn_mon_timer);
35 	del_timer_sync(&ifmgd->conn_mon_timer);
36 
37 	cancel_work_sync(&local->dynamic_ps_enable_work);
38 
39 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
40 		local->offchannel_ps_enabled = true;
41 		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
42 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
43 	}
44 
45 	if (!local->offchannel_ps_enabled ||
46 	    !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
47 		/*
48 		 * If power save was enabled, no need to send a nullfunc
49 		 * frame because AP knows that we are sleeping. But if the
50 		 * hardware is creating the nullfunc frame for power save
51 		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
52 		 * enabled) and power save was enabled, the firmware just
53 		 * sent a null frame with power save disabled. So we need
54 		 * to send a new nullfunc frame to inform the AP that we
55 		 * are again sleeping.
56 		 */
57 		ieee80211_send_nullfunc(local, sdata, true);
58 }
59 
60 /* inform AP that we are awake again, unless power save is enabled */
61 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
62 {
63 	struct ieee80211_local *local = sdata->local;
64 
65 	if (!local->ps_sdata)
66 		ieee80211_send_nullfunc(local, sdata, false);
67 	else if (local->offchannel_ps_enabled) {
68 		/*
69 		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
70 		 * will send a nullfunc frame with the powersave bit set
71 		 * even though the AP already knows that we are sleeping.
72 		 * This could be avoided by sending a null frame with power
73 		 * save bit disabled before enabling the power save, but
74 		 * this doesn't gain anything.
75 		 *
76 		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
77 		 * to send a nullfunc frame because AP already knows that
78 		 * we are sleeping, let's just enable power save mode in
79 		 * hardware.
80 		 */
81 		/* TODO:  Only set hardware if CONF_PS changed?
82 		 * TODO:  Should we set offchannel_ps_enabled to false?
83 		 */
84 		local->hw.conf.flags |= IEEE80211_CONF_PS;
85 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
86 	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
87 		/*
88 		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
89 		 * had been running before leaving the operating channel,
90 		 * restart the timer now and send a nullfunc frame to inform
91 		 * the AP that we are awake.
92 		 */
93 		ieee80211_send_nullfunc(local, sdata, false);
94 		mod_timer(&local->dynamic_ps_timer, jiffies +
95 			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
96 	}
97 
98 	ieee80211_sta_reset_beacon_monitor(sdata);
99 	ieee80211_sta_reset_conn_monitor(sdata);
100 }
101 
102 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
103 {
104 	struct ieee80211_sub_if_data *sdata;
105 
106 	if (WARN_ON(local->use_chanctx))
107 		return;
108 
109 	/*
110 	 * notify the AP about us leaving the channel and stop all
111 	 * STA interfaces.
112 	 */
113 
114 	/*
115 	 * Stop queues and transmit all frames queued by the driver
116 	 * before sending nullfunc to enable powersave at the AP.
117 	 */
118 	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
119 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
120 					false);
121 	ieee80211_flush_queues(local, NULL, false);
122 
123 	mutex_lock(&local->iflist_mtx);
124 	list_for_each_entry(sdata, &local->interfaces, list) {
125 		if (!ieee80211_sdata_running(sdata))
126 			continue;
127 
128 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
129 		    sdata->vif.type == NL80211_IFTYPE_NAN)
130 			continue;
131 
132 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
133 			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
134 
135 		/* Check to see if we should disable beaconing. */
136 		if (sdata->vif.bss_conf.enable_beacon) {
137 			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
138 				&sdata->state);
139 			sdata->vif.bss_conf.enable_beacon = false;
140 			ieee80211_bss_info_change_notify(
141 				sdata, BSS_CHANGED_BEACON_ENABLED);
142 		}
143 
144 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
145 		    sdata->u.mgd.associated)
146 			ieee80211_offchannel_ps_enable(sdata);
147 	}
148 	mutex_unlock(&local->iflist_mtx);
149 }
150 
151 void ieee80211_offchannel_return(struct ieee80211_local *local)
152 {
153 	struct ieee80211_sub_if_data *sdata;
154 
155 	if (WARN_ON(local->use_chanctx))
156 		return;
157 
158 	mutex_lock(&local->iflist_mtx);
159 	list_for_each_entry(sdata, &local->interfaces, list) {
160 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
161 			continue;
162 
163 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
164 			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
165 
166 		if (!ieee80211_sdata_running(sdata))
167 			continue;
168 
169 		/* Tell AP we're back */
170 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
171 		    sdata->u.mgd.associated)
172 			ieee80211_offchannel_ps_disable(sdata);
173 
174 		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
175 				       &sdata->state)) {
176 			sdata->vif.bss_conf.enable_beacon = true;
177 			ieee80211_bss_info_change_notify(
178 				sdata, BSS_CHANGED_BEACON_ENABLED);
179 		}
180 	}
181 	mutex_unlock(&local->iflist_mtx);
182 
183 	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
184 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
185 					false);
186 }
187 
188 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
189 {
190 	/* was never transmitted */
191 	if (roc->frame) {
192 		cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
193 					roc->frame->data, roc->frame->len,
194 					false, GFP_KERNEL);
195 		ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
196 	}
197 
198 	if (!roc->mgmt_tx_cookie)
199 		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
200 						   roc->cookie, roc->chan,
201 						   GFP_KERNEL);
202 	else
203 		cfg80211_tx_mgmt_expired(&roc->sdata->wdev,
204 					 roc->mgmt_tx_cookie,
205 					 roc->chan, GFP_KERNEL);
206 
207 	list_del(&roc->list);
208 	kfree(roc);
209 }
210 
211 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
212 						 unsigned long now)
213 {
214 	struct ieee80211_roc_work *roc, *tmp;
215 	long remaining_dur_min = LONG_MAX;
216 
217 	lockdep_assert_held(&local->mtx);
218 
219 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
220 		long remaining;
221 
222 		if (!roc->started)
223 			break;
224 
225 		remaining = roc->start_time +
226 			    msecs_to_jiffies(roc->duration) -
227 			    now;
228 
229 		/* In case of HW ROC, it is possible that the HW finished the
230 		 * ROC session before the actual requested time. In such a case
231 		 * end the ROC session (disregarding the remaining time).
232 		 */
233 		if (roc->abort || roc->hw_begun || remaining <= 0)
234 			ieee80211_roc_notify_destroy(roc);
235 		else
236 			remaining_dur_min = min(remaining_dur_min, remaining);
237 	}
238 
239 	return remaining_dur_min;
240 }
241 
242 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
243 				     unsigned long now)
244 {
245 	long dur = ieee80211_end_finished_rocs(local, now);
246 
247 	if (dur == LONG_MAX)
248 		return false;
249 
250 	mod_delayed_work(local->workqueue, &local->roc_work, dur);
251 	return true;
252 }
253 
254 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
255 					 unsigned long start_time)
256 {
257 	if (WARN_ON(roc->notified))
258 		return;
259 
260 	roc->start_time = start_time;
261 	roc->started = true;
262 
263 	if (roc->mgmt_tx_cookie) {
264 		if (!WARN_ON(!roc->frame)) {
265 			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
266 						  roc->chan->band, 0);
267 			roc->frame = NULL;
268 		}
269 	} else {
270 		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
271 					  roc->chan, roc->req_duration,
272 					  GFP_KERNEL);
273 	}
274 
275 	roc->notified = true;
276 }
277 
278 static void ieee80211_hw_roc_start(struct work_struct *work)
279 {
280 	struct ieee80211_local *local =
281 		container_of(work, struct ieee80211_local, hw_roc_start);
282 	struct ieee80211_roc_work *roc;
283 
284 	mutex_lock(&local->mtx);
285 
286 	list_for_each_entry(roc, &local->roc_list, list) {
287 		if (!roc->started)
288 			break;
289 
290 		roc->hw_begun = true;
291 		ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
292 	}
293 
294 	mutex_unlock(&local->mtx);
295 }
296 
297 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
298 {
299 	struct ieee80211_local *local = hw_to_local(hw);
300 
301 	local->hw_roc_start_time = jiffies;
302 
303 	trace_api_ready_on_channel(local);
304 
305 	ieee80211_queue_work(hw, &local->hw_roc_start);
306 }
307 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
308 
309 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
310 {
311 	struct ieee80211_roc_work *roc, *tmp;
312 	enum ieee80211_roc_type type;
313 	u32 min_dur, max_dur;
314 
315 	lockdep_assert_held(&local->mtx);
316 
317 	if (WARN_ON(list_empty(&local->roc_list)))
318 		return;
319 
320 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
321 			       list);
322 
323 	if (WARN_ON(roc->started))
324 		return;
325 
326 	min_dur = roc->duration;
327 	max_dur = roc->duration;
328 	type = roc->type;
329 
330 	list_for_each_entry(tmp, &local->roc_list, list) {
331 		if (tmp == roc)
332 			continue;
333 		if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
334 			break;
335 		max_dur = max(tmp->duration, max_dur);
336 		min_dur = min(tmp->duration, min_dur);
337 		type = max(tmp->type, type);
338 	}
339 
340 	if (local->ops->remain_on_channel) {
341 		int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
342 						max_dur, type);
343 
344 		if (ret) {
345 			wiphy_warn(local->hw.wiphy,
346 				   "failed to start next HW ROC (%d)\n", ret);
347 			/*
348 			 * queue the work struct again to avoid recursion
349 			 * when multiple failures occur
350 			 */
351 			list_for_each_entry(tmp, &local->roc_list, list) {
352 				if (tmp->sdata != roc->sdata ||
353 				    tmp->chan != roc->chan)
354 					break;
355 				tmp->started = true;
356 				tmp->abort = true;
357 			}
358 			ieee80211_queue_work(&local->hw, &local->hw_roc_done);
359 			return;
360 		}
361 
362 		/* we'll notify about the start once the HW calls back */
363 		list_for_each_entry(tmp, &local->roc_list, list) {
364 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
365 				break;
366 			tmp->started = true;
367 		}
368 	} else {
369 		/* If actually operating on the desired channel (with at least
370 		 * 20 MHz channel width) don't stop all the operations but still
371 		 * treat it as though the ROC operation started properly, so
372 		 * other ROC operations won't interfere with this one.
373 		 */
374 		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
375 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
376 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
377 
378 		/* start this ROC */
379 		ieee80211_recalc_idle(local);
380 
381 		if (!roc->on_channel) {
382 			ieee80211_offchannel_stop_vifs(local);
383 
384 			local->tmp_channel = roc->chan;
385 			ieee80211_hw_config(local, 0);
386 		}
387 
388 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
389 					     msecs_to_jiffies(min_dur));
390 
391 		/* tell userspace or send frame(s) */
392 		list_for_each_entry(tmp, &local->roc_list, list) {
393 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
394 				break;
395 
396 			tmp->on_channel = roc->on_channel;
397 			ieee80211_handle_roc_started(tmp, jiffies);
398 		}
399 	}
400 }
401 
402 void ieee80211_start_next_roc(struct ieee80211_local *local)
403 {
404 	struct ieee80211_roc_work *roc;
405 
406 	lockdep_assert_held(&local->mtx);
407 
408 	if (list_empty(&local->roc_list)) {
409 		ieee80211_run_deferred_scan(local);
410 		return;
411 	}
412 
413 	/* defer roc if driver is not started (i.e. during reconfig) */
414 	if (local->in_reconfig)
415 		return;
416 
417 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
418 			       list);
419 
420 	if (WARN_ON_ONCE(roc->started))
421 		return;
422 
423 	if (local->ops->remain_on_channel) {
424 		_ieee80211_start_next_roc(local);
425 	} else {
426 		/* delay it a bit */
427 		ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
428 					     round_jiffies_relative(HZ/2));
429 	}
430 }
431 
432 static void __ieee80211_roc_work(struct ieee80211_local *local)
433 {
434 	struct ieee80211_roc_work *roc;
435 	bool on_channel;
436 
437 	lockdep_assert_held(&local->mtx);
438 
439 	if (WARN_ON(local->ops->remain_on_channel))
440 		return;
441 
442 	roc = list_first_entry_or_null(&local->roc_list,
443 				       struct ieee80211_roc_work, list);
444 	if (!roc)
445 		return;
446 
447 	if (!roc->started) {
448 		WARN_ON(local->use_chanctx);
449 		_ieee80211_start_next_roc(local);
450 	} else {
451 		on_channel = roc->on_channel;
452 		if (ieee80211_recalc_sw_work(local, jiffies))
453 			return;
454 
455 		/* careful - roc pointer became invalid during recalc */
456 
457 		if (!on_channel) {
458 			ieee80211_flush_queues(local, NULL, false);
459 
460 			local->tmp_channel = NULL;
461 			ieee80211_hw_config(local, 0);
462 
463 			ieee80211_offchannel_return(local);
464 		}
465 
466 		ieee80211_recalc_idle(local);
467 		ieee80211_start_next_roc(local);
468 	}
469 }
470 
471 static void ieee80211_roc_work(struct work_struct *work)
472 {
473 	struct ieee80211_local *local =
474 		container_of(work, struct ieee80211_local, roc_work.work);
475 
476 	mutex_lock(&local->mtx);
477 	__ieee80211_roc_work(local);
478 	mutex_unlock(&local->mtx);
479 }
480 
481 static void ieee80211_hw_roc_done(struct work_struct *work)
482 {
483 	struct ieee80211_local *local =
484 		container_of(work, struct ieee80211_local, hw_roc_done);
485 
486 	mutex_lock(&local->mtx);
487 
488 	ieee80211_end_finished_rocs(local, jiffies);
489 
490 	/* if there's another roc, start it now */
491 	ieee80211_start_next_roc(local);
492 
493 	mutex_unlock(&local->mtx);
494 }
495 
496 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
497 {
498 	struct ieee80211_local *local = hw_to_local(hw);
499 
500 	trace_api_remain_on_channel_expired(local);
501 
502 	ieee80211_queue_work(hw, &local->hw_roc_done);
503 }
504 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
505 
506 static bool
507 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
508 				  struct ieee80211_roc_work *new_roc,
509 				  struct ieee80211_roc_work *cur_roc)
510 {
511 	unsigned long now = jiffies;
512 	unsigned long remaining;
513 
514 	if (WARN_ON(!cur_roc->started))
515 		return false;
516 
517 	/* if it was scheduled in the hardware, but not started yet,
518 	 * we can only combine if the older one had a longer duration
519 	 */
520 	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
521 		return false;
522 
523 	remaining = cur_roc->start_time +
524 		    msecs_to_jiffies(cur_roc->duration) -
525 		    now;
526 
527 	/* if it doesn't fit entirely, schedule a new one */
528 	if (new_roc->duration > jiffies_to_msecs(remaining))
529 		return false;
530 
531 	/* add just after the current one so we combine their finish later */
532 	list_add(&new_roc->list, &cur_roc->list);
533 
534 	/* if the existing one has already begun then let this one also
535 	 * begin, otherwise they'll both be marked properly by the work
536 	 * struct that runs once the driver notifies us of the beginning
537 	 */
538 	if (cur_roc->hw_begun) {
539 		new_roc->hw_begun = true;
540 		ieee80211_handle_roc_started(new_roc, now);
541 	}
542 
543 	return true;
544 }
545 
546 static int ieee80211_start_roc_work(struct ieee80211_local *local,
547 				    struct ieee80211_sub_if_data *sdata,
548 				    struct ieee80211_channel *channel,
549 				    unsigned int duration, u64 *cookie,
550 				    struct sk_buff *txskb,
551 				    enum ieee80211_roc_type type)
552 {
553 	struct ieee80211_roc_work *roc, *tmp;
554 	bool queued = false, combine_started = true;
555 	int ret;
556 
557 	lockdep_assert_held(&local->mtx);
558 
559 	if (local->use_chanctx && !local->ops->remain_on_channel)
560 		return -EOPNOTSUPP;
561 
562 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
563 	if (!roc)
564 		return -ENOMEM;
565 
566 	/*
567 	 * If the duration is zero, then the driver
568 	 * wouldn't actually do anything. Set it to
569 	 * 10 for now.
570 	 *
571 	 * TODO: cancel the off-channel operation
572 	 *       when we get the SKB's TX status and
573 	 *       the wait time was zero before.
574 	 */
575 	if (!duration)
576 		duration = 10;
577 
578 	roc->chan = channel;
579 	roc->duration = duration;
580 	roc->req_duration = duration;
581 	roc->frame = txskb;
582 	roc->type = type;
583 	roc->sdata = sdata;
584 
585 	/*
586 	 * cookie is either the roc cookie (for normal roc)
587 	 * or the SKB (for mgmt TX)
588 	 */
589 	if (!txskb) {
590 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
591 		*cookie = roc->cookie;
592 	} else {
593 		roc->mgmt_tx_cookie = *cookie;
594 	}
595 
596 	/* if there's no need to queue, handle it immediately */
597 	if (list_empty(&local->roc_list) &&
598 	    !local->scanning && !ieee80211_is_radar_required(local)) {
599 		/* if not HW assist, just queue & schedule work */
600 		if (!local->ops->remain_on_channel) {
601 			list_add_tail(&roc->list, &local->roc_list);
602 			ieee80211_queue_delayed_work(&local->hw,
603 						     &local->roc_work, 0);
604 		} else {
605 			/* otherwise actually kick it off here
606 			 * (for error handling)
607 			 */
608 			ret = drv_remain_on_channel(local, sdata, channel,
609 						    duration, type);
610 			if (ret) {
611 				kfree(roc);
612 				return ret;
613 			}
614 			roc->started = true;
615 			list_add_tail(&roc->list, &local->roc_list);
616 		}
617 
618 		return 0;
619 	}
620 
621 	/* otherwise handle queueing */
622 
623 	list_for_each_entry(tmp, &local->roc_list, list) {
624 		if (tmp->chan != channel || tmp->sdata != sdata)
625 			continue;
626 
627 		/*
628 		 * Extend this ROC if possible: If it hasn't started, add
629 		 * just after the new one to combine.
630 		 */
631 		if (!tmp->started) {
632 			list_add(&roc->list, &tmp->list);
633 			queued = true;
634 			break;
635 		}
636 
637 		if (!combine_started)
638 			continue;
639 
640 		if (!local->ops->remain_on_channel) {
641 			/* If there's no hardware remain-on-channel, and
642 			 * doing so won't push us over the maximum r-o-c
643 			 * we allow, then we can just add the new one to
644 			 * the list and mark it as having started now.
645 			 * If it would push over the limit, don't try to
646 			 * combine with other started ones (that haven't
647 			 * been running as long) but potentially sort it
648 			 * with others that had the same fate.
649 			 */
650 			unsigned long now = jiffies;
651 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
652 			struct wiphy *wiphy = local->hw.wiphy;
653 			u32 max_roc = wiphy->max_remain_on_channel_duration;
654 
655 			if (elapsed + roc->duration > max_roc) {
656 				combine_started = false;
657 				continue;
658 			}
659 
660 			list_add(&roc->list, &tmp->list);
661 			queued = true;
662 			roc->on_channel = tmp->on_channel;
663 			ieee80211_handle_roc_started(roc, now);
664 			ieee80211_recalc_sw_work(local, now);
665 			break;
666 		}
667 
668 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
669 		if (queued)
670 			break;
671 		/* if it wasn't queued, perhaps it can be combined with
672 		 * another that also couldn't get combined previously,
673 		 * but no need to check for already started ones, since
674 		 * that can't work.
675 		 */
676 		combine_started = false;
677 	}
678 
679 	if (!queued)
680 		list_add_tail(&roc->list, &local->roc_list);
681 
682 	return 0;
683 }
684 
685 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
686 				struct ieee80211_channel *chan,
687 				unsigned int duration, u64 *cookie)
688 {
689 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
690 	struct ieee80211_local *local = sdata->local;
691 	int ret;
692 
693 	mutex_lock(&local->mtx);
694 	ret = ieee80211_start_roc_work(local, sdata, chan,
695 				       duration, cookie, NULL,
696 				       IEEE80211_ROC_TYPE_NORMAL);
697 	mutex_unlock(&local->mtx);
698 
699 	return ret;
700 }
701 
702 static int ieee80211_cancel_roc(struct ieee80211_local *local,
703 				u64 cookie, bool mgmt_tx)
704 {
705 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
706 	int ret;
707 
708 	if (!cookie)
709 		return -ENOENT;
710 
711 	flush_work(&local->hw_roc_start);
712 
713 	mutex_lock(&local->mtx);
714 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
715 		if (!mgmt_tx && roc->cookie != cookie)
716 			continue;
717 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
718 			continue;
719 
720 		found = roc;
721 		break;
722 	}
723 
724 	if (!found) {
725 		mutex_unlock(&local->mtx);
726 		return -ENOENT;
727 	}
728 
729 	if (!found->started) {
730 		ieee80211_roc_notify_destroy(found);
731 		goto out_unlock;
732 	}
733 
734 	if (local->ops->remain_on_channel) {
735 		ret = drv_cancel_remain_on_channel(local);
736 		if (WARN_ON_ONCE(ret)) {
737 			mutex_unlock(&local->mtx);
738 			return ret;
739 		}
740 
741 		/* TODO:
742 		 * if multiple items were combined here then we really shouldn't
743 		 * cancel them all - we should wait for as much time as needed
744 		 * for the longest remaining one, and only then cancel ...
745 		 */
746 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
747 			if (!roc->started)
748 				break;
749 			if (roc == found)
750 				found = NULL;
751 			ieee80211_roc_notify_destroy(roc);
752 		}
753 
754 		/* that really must not happen - it was started */
755 		WARN_ON(found);
756 
757 		ieee80211_start_next_roc(local);
758 	} else {
759 		/* go through work struct to return to the operating channel */
760 		found->abort = true;
761 		mod_delayed_work(local->workqueue, &local->roc_work, 0);
762 	}
763 
764  out_unlock:
765 	mutex_unlock(&local->mtx);
766 
767 	return 0;
768 }
769 
770 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
771 				       struct wireless_dev *wdev, u64 cookie)
772 {
773 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
774 	struct ieee80211_local *local = sdata->local;
775 
776 	return ieee80211_cancel_roc(local, cookie, false);
777 }
778 
779 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
780 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
781 {
782 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
783 	struct ieee80211_local *local = sdata->local;
784 	struct sk_buff *skb;
785 	struct sta_info *sta;
786 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
787 	bool need_offchan = false;
788 	u32 flags;
789 	int ret;
790 	u8 *data;
791 
792 	if (params->dont_wait_for_ack)
793 		flags = IEEE80211_TX_CTL_NO_ACK;
794 	else
795 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
796 			IEEE80211_TX_CTL_REQ_TX_STATUS;
797 
798 	if (params->no_cck)
799 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
800 
801 	switch (sdata->vif.type) {
802 	case NL80211_IFTYPE_ADHOC:
803 		if (!sdata->vif.bss_conf.ibss_joined)
804 			need_offchan = true;
805 #ifdef CONFIG_MAC80211_MESH
806 		/* fall through */
807 	case NL80211_IFTYPE_MESH_POINT:
808 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
809 		    !sdata->u.mesh.mesh_id_len)
810 			need_offchan = true;
811 #endif
812 		/* fall through */
813 	case NL80211_IFTYPE_AP:
814 	case NL80211_IFTYPE_AP_VLAN:
815 	case NL80211_IFTYPE_P2P_GO:
816 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
817 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
818 		    !rcu_access_pointer(sdata->bss->beacon))
819 			need_offchan = true;
820 		if (!ieee80211_is_action(mgmt->frame_control) ||
821 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
822 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
823 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
824 			break;
825 		rcu_read_lock();
826 		sta = sta_info_get_bss(sdata, mgmt->da);
827 		rcu_read_unlock();
828 		if (!sta)
829 			return -ENOLINK;
830 		break;
831 	case NL80211_IFTYPE_STATION:
832 	case NL80211_IFTYPE_P2P_CLIENT:
833 		sdata_lock(sdata);
834 		if (!sdata->u.mgd.associated ||
835 		    (params->offchan && params->wait &&
836 		     local->ops->remain_on_channel &&
837 		     memcmp(sdata->u.mgd.associated->bssid,
838 			    mgmt->bssid, ETH_ALEN)))
839 			need_offchan = true;
840 		sdata_unlock(sdata);
841 		break;
842 	case NL80211_IFTYPE_P2P_DEVICE:
843 		need_offchan = true;
844 		break;
845 	case NL80211_IFTYPE_NAN:
846 	default:
847 		return -EOPNOTSUPP;
848 	}
849 
850 	/* configurations requiring offchan cannot work if no channel has been
851 	 * specified
852 	 */
853 	if (need_offchan && !params->chan)
854 		return -EINVAL;
855 
856 	mutex_lock(&local->mtx);
857 
858 	/* Check if the operating channel is the requested channel */
859 	if (!need_offchan) {
860 		struct ieee80211_chanctx_conf *chanctx_conf;
861 
862 		rcu_read_lock();
863 		chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
864 
865 		if (chanctx_conf) {
866 			need_offchan = params->chan &&
867 				       (params->chan !=
868 					chanctx_conf->def.chan);
869 		} else if (!params->chan) {
870 			ret = -EINVAL;
871 			rcu_read_unlock();
872 			goto out_unlock;
873 		} else {
874 			need_offchan = true;
875 		}
876 		rcu_read_unlock();
877 	}
878 
879 	if (need_offchan && !params->offchan) {
880 		ret = -EBUSY;
881 		goto out_unlock;
882 	}
883 
884 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
885 	if (!skb) {
886 		ret = -ENOMEM;
887 		goto out_unlock;
888 	}
889 	skb_reserve(skb, local->hw.extra_tx_headroom);
890 
891 	data = skb_put_data(skb, params->buf, params->len);
892 
893 	/* Update CSA counters */
894 	if (sdata->vif.csa_active &&
895 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
896 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
897 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
898 	    params->n_csa_offsets) {
899 		int i;
900 		struct beacon_data *beacon = NULL;
901 
902 		rcu_read_lock();
903 
904 		if (sdata->vif.type == NL80211_IFTYPE_AP)
905 			beacon = rcu_dereference(sdata->u.ap.beacon);
906 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
907 			beacon = rcu_dereference(sdata->u.ibss.presp);
908 		else if (ieee80211_vif_is_mesh(&sdata->vif))
909 			beacon = rcu_dereference(sdata->u.mesh.beacon);
910 
911 		if (beacon)
912 			for (i = 0; i < params->n_csa_offsets; i++)
913 				data[params->csa_offsets[i]] =
914 					beacon->csa_current_counter;
915 
916 		rcu_read_unlock();
917 	}
918 
919 	IEEE80211_SKB_CB(skb)->flags = flags;
920 
921 	skb->dev = sdata->dev;
922 
923 	if (!params->dont_wait_for_ack) {
924 		/* make a copy to preserve the frame contents
925 		 * in case of encryption.
926 		 */
927 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
928 		if (ret) {
929 			kfree_skb(skb);
930 			goto out_unlock;
931 		}
932 	} else {
933 		/* Assign a dummy non-zero cookie, it's not sent to
934 		 * userspace in this case but we rely on its value
935 		 * internally in the need_offchan case to distinguish
936 		 * mgmt-tx from remain-on-channel.
937 		 */
938 		*cookie = 0xffffffff;
939 	}
940 
941 	if (!need_offchan) {
942 		ieee80211_tx_skb(sdata, skb);
943 		ret = 0;
944 		goto out_unlock;
945 	}
946 
947 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
948 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
949 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
950 		IEEE80211_SKB_CB(skb)->hw_queue =
951 			local->hw.offchannel_tx_hw_queue;
952 
953 	/* This will handle all kinds of coalescing and immediate TX */
954 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
955 				       params->wait, cookie, skb,
956 				       IEEE80211_ROC_TYPE_MGMT_TX);
957 	if (ret)
958 		ieee80211_free_txskb(&local->hw, skb);
959  out_unlock:
960 	mutex_unlock(&local->mtx);
961 	return ret;
962 }
963 
964 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
965 				  struct wireless_dev *wdev, u64 cookie)
966 {
967 	struct ieee80211_local *local = wiphy_priv(wiphy);
968 
969 	return ieee80211_cancel_roc(local, cookie, true);
970 }
971 
972 void ieee80211_roc_setup(struct ieee80211_local *local)
973 {
974 	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
975 	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
976 	INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
977 	INIT_LIST_HEAD(&local->roc_list);
978 }
979 
980 void ieee80211_roc_purge(struct ieee80211_local *local,
981 			 struct ieee80211_sub_if_data *sdata)
982 {
983 	struct ieee80211_roc_work *roc, *tmp;
984 	bool work_to_do = false;
985 
986 	mutex_lock(&local->mtx);
987 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
988 		if (sdata && roc->sdata != sdata)
989 			continue;
990 
991 		if (roc->started) {
992 			if (local->ops->remain_on_channel) {
993 				/* can race, so ignore return value */
994 				drv_cancel_remain_on_channel(local);
995 				ieee80211_roc_notify_destroy(roc);
996 			} else {
997 				roc->abort = true;
998 				work_to_do = true;
999 			}
1000 		} else {
1001 			ieee80211_roc_notify_destroy(roc);
1002 		}
1003 	}
1004 	if (work_to_do)
1005 		__ieee80211_roc_work(local);
1006 	mutex_unlock(&local->mtx);
1007 }
1008