xref: /linux/net/mac80211/offchannel.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
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, 2022-2023 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 	bool offchannel_ps_enabled = false;
30 
31 	/* FIXME: what to do when local->pspolling is true? */
32 
33 	del_timer_sync(&local->dynamic_ps_timer);
34 	del_timer_sync(&ifmgd->bcn_mon_timer);
35 	del_timer_sync(&ifmgd->conn_mon_timer);
36 
37 	wiphy_work_cancel(local->hw.wiphy, &local->dynamic_ps_enable_work);
38 
39 	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
40 		offchannel_ps_enabled = true;
41 		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
42 		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
43 	}
44 
45 	if (!offchannel_ps_enabled ||
46 	    !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
47 		/*
48 		 * If power save was enabled, no need to send a nullfunc
49 		 * frame because AP knows that we are sleeping. But if the
50 		 * hardware is creating the nullfunc frame for power save
51 		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
52 		 * enabled) and power save was enabled, the firmware just
53 		 * sent a null frame with power save disabled. So we need
54 		 * to send a new nullfunc frame to inform the AP that we
55 		 * are again sleeping.
56 		 */
57 		ieee80211_send_nullfunc(local, sdata, true);
58 }
59 
60 /* inform AP that we are awake again */
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->hw.conf.dynamic_ps_timeout > 0) {
68 		/*
69 		 * the dynamic_ps_timer had been running before leaving the
70 		 * operating channel, restart the timer now and send a nullfunc
71 		 * frame to inform the AP that we are awake so that AP sends
72 		 * the buffered packets (if any).
73 		 */
74 		ieee80211_send_nullfunc(local, sdata, false);
75 		mod_timer(&local->dynamic_ps_timer, jiffies +
76 			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
77 	}
78 
79 	ieee80211_sta_reset_beacon_monitor(sdata);
80 	ieee80211_sta_reset_conn_monitor(sdata);
81 }
82 
83 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
84 {
85 	struct ieee80211_sub_if_data *sdata;
86 
87 	lockdep_assert_wiphy(local->hw.wiphy);
88 
89 	if (WARN_ON(local->use_chanctx))
90 		return;
91 
92 	/*
93 	 * notify the AP about us leaving the channel and stop all
94 	 * STA interfaces.
95 	 */
96 
97 	/*
98 	 * Stop queues and transmit all frames queued by the driver
99 	 * before sending nullfunc to enable powersave at the AP.
100 	 */
101 	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
102 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
103 					false);
104 	ieee80211_flush_queues(local, NULL, false);
105 
106 	list_for_each_entry(sdata, &local->interfaces, list) {
107 		if (!ieee80211_sdata_running(sdata))
108 			continue;
109 
110 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
111 		    sdata->vif.type == NL80211_IFTYPE_NAN)
112 			continue;
113 
114 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
115 			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
116 
117 		/* Check to see if we should disable beaconing. */
118 		if (sdata->vif.bss_conf.enable_beacon) {
119 			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
120 				&sdata->state);
121 			sdata->vif.bss_conf.enable_beacon = false;
122 			ieee80211_link_info_change_notify(
123 				sdata, &sdata->deflink,
124 				BSS_CHANGED_BEACON_ENABLED);
125 		}
126 
127 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
128 		    sdata->u.mgd.associated)
129 			ieee80211_offchannel_ps_enable(sdata);
130 	}
131 }
132 
133 void ieee80211_offchannel_return(struct ieee80211_local *local)
134 {
135 	struct ieee80211_sub_if_data *sdata;
136 
137 	lockdep_assert_wiphy(local->hw.wiphy);
138 
139 	if (WARN_ON(local->use_chanctx))
140 		return;
141 
142 	list_for_each_entry(sdata, &local->interfaces, list) {
143 		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
144 			continue;
145 
146 		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
147 			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
148 
149 		if (!ieee80211_sdata_running(sdata))
150 			continue;
151 
152 		/* Tell AP we're back */
153 		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
154 		    sdata->u.mgd.associated)
155 			ieee80211_offchannel_ps_disable(sdata);
156 
157 		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
158 				       &sdata->state)) {
159 			sdata->vif.bss_conf.enable_beacon = true;
160 			ieee80211_link_info_change_notify(
161 				sdata, &sdata->deflink,
162 				BSS_CHANGED_BEACON_ENABLED);
163 		}
164 	}
165 
166 	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
167 					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
168 					false);
169 }
170 
171 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
172 {
173 	/* was never transmitted */
174 	if (roc->frame) {
175 		cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
176 					roc->frame->data, roc->frame->len,
177 					false, GFP_KERNEL);
178 		ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
179 	}
180 
181 	if (!roc->mgmt_tx_cookie)
182 		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
183 						   roc->cookie, roc->chan,
184 						   GFP_KERNEL);
185 	else
186 		cfg80211_tx_mgmt_expired(&roc->sdata->wdev,
187 					 roc->mgmt_tx_cookie,
188 					 roc->chan, GFP_KERNEL);
189 
190 	list_del(&roc->list);
191 	kfree(roc);
192 }
193 
194 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
195 						 unsigned long now)
196 {
197 	struct ieee80211_roc_work *roc, *tmp;
198 	long remaining_dur_min = LONG_MAX;
199 
200 	lockdep_assert_wiphy(local->hw.wiphy);
201 
202 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
203 		long remaining;
204 
205 		if (!roc->started)
206 			break;
207 
208 		remaining = roc->start_time +
209 			    msecs_to_jiffies(roc->duration) -
210 			    now;
211 
212 		/* In case of HW ROC, it is possible that the HW finished the
213 		 * ROC session before the actual requested time. In such a case
214 		 * end the ROC session (disregarding the remaining time).
215 		 */
216 		if (roc->abort || roc->hw_begun || remaining <= 0)
217 			ieee80211_roc_notify_destroy(roc);
218 		else
219 			remaining_dur_min = min(remaining_dur_min, remaining);
220 	}
221 
222 	return remaining_dur_min;
223 }
224 
225 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
226 				     unsigned long now)
227 {
228 	long dur = ieee80211_end_finished_rocs(local, now);
229 
230 	if (dur == LONG_MAX)
231 		return false;
232 
233 	wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work, dur);
234 	return true;
235 }
236 
237 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
238 					 unsigned long start_time)
239 {
240 	if (WARN_ON(roc->notified))
241 		return;
242 
243 	roc->start_time = start_time;
244 	roc->started = true;
245 
246 	if (roc->mgmt_tx_cookie) {
247 		if (!WARN_ON(!roc->frame)) {
248 			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
249 						  roc->chan->band);
250 			roc->frame = NULL;
251 		}
252 	} else {
253 		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
254 					  roc->chan, roc->req_duration,
255 					  GFP_KERNEL);
256 	}
257 
258 	roc->notified = true;
259 }
260 
261 static void ieee80211_hw_roc_start(struct wiphy *wiphy, struct wiphy_work *work)
262 {
263 	struct ieee80211_local *local =
264 		container_of(work, struct ieee80211_local, hw_roc_start);
265 	struct ieee80211_roc_work *roc;
266 
267 	lockdep_assert_wiphy(local->hw.wiphy);
268 
269 	list_for_each_entry(roc, &local->roc_list, list) {
270 		if (!roc->started)
271 			break;
272 
273 		roc->hw_begun = true;
274 		ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
275 	}
276 }
277 
278 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
279 {
280 	struct ieee80211_local *local = hw_to_local(hw);
281 
282 	local->hw_roc_start_time = jiffies;
283 
284 	trace_api_ready_on_channel(local);
285 
286 	wiphy_work_queue(hw->wiphy, &local->hw_roc_start);
287 }
288 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
289 
290 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
291 {
292 	struct ieee80211_roc_work *roc, *tmp;
293 	enum ieee80211_roc_type type;
294 	u32 min_dur, max_dur;
295 
296 	lockdep_assert_wiphy(local->hw.wiphy);
297 
298 	if (WARN_ON(list_empty(&local->roc_list)))
299 		return;
300 
301 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
302 			       list);
303 
304 	if (WARN_ON(roc->started))
305 		return;
306 
307 	min_dur = roc->duration;
308 	max_dur = roc->duration;
309 	type = roc->type;
310 
311 	list_for_each_entry(tmp, &local->roc_list, list) {
312 		if (tmp == roc)
313 			continue;
314 		if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
315 			break;
316 		max_dur = max(tmp->duration, max_dur);
317 		min_dur = min(tmp->duration, min_dur);
318 		type = max(tmp->type, type);
319 	}
320 
321 	if (local->ops->remain_on_channel) {
322 		int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
323 						max_dur, type);
324 
325 		if (ret) {
326 			wiphy_warn(local->hw.wiphy,
327 				   "failed to start next HW ROC (%d)\n", ret);
328 			/*
329 			 * queue the work struct again to avoid recursion
330 			 * when multiple failures occur
331 			 */
332 			list_for_each_entry(tmp, &local->roc_list, list) {
333 				if (tmp->sdata != roc->sdata ||
334 				    tmp->chan != roc->chan)
335 					break;
336 				tmp->started = true;
337 				tmp->abort = true;
338 			}
339 			wiphy_work_queue(local->hw.wiphy, &local->hw_roc_done);
340 			return;
341 		}
342 
343 		/* we'll notify about the start once the HW calls back */
344 		list_for_each_entry(tmp, &local->roc_list, list) {
345 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
346 				break;
347 			tmp->started = true;
348 		}
349 	} else {
350 		/* If actually operating on the desired channel (with at least
351 		 * 20 MHz channel width) don't stop all the operations but still
352 		 * treat it as though the ROC operation started properly, so
353 		 * other ROC operations won't interfere with this one.
354 		 */
355 		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
356 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
357 				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
358 
359 		/* start this ROC */
360 		ieee80211_recalc_idle(local);
361 
362 		if (!roc->on_channel) {
363 			ieee80211_offchannel_stop_vifs(local);
364 
365 			local->tmp_channel = roc->chan;
366 			ieee80211_hw_config(local, 0);
367 		}
368 
369 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work,
370 					 msecs_to_jiffies(min_dur));
371 
372 		/* tell userspace or send frame(s) */
373 		list_for_each_entry(tmp, &local->roc_list, list) {
374 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
375 				break;
376 
377 			tmp->on_channel = roc->on_channel;
378 			ieee80211_handle_roc_started(tmp, jiffies);
379 		}
380 	}
381 }
382 
383 void ieee80211_start_next_roc(struct ieee80211_local *local)
384 {
385 	struct ieee80211_roc_work *roc;
386 
387 	lockdep_assert_wiphy(local->hw.wiphy);
388 
389 	if (list_empty(&local->roc_list)) {
390 		ieee80211_run_deferred_scan(local);
391 		return;
392 	}
393 
394 	/* defer roc if driver is not started (i.e. during reconfig) */
395 	if (local->in_reconfig)
396 		return;
397 
398 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
399 			       list);
400 
401 	if (WARN_ON_ONCE(roc->started))
402 		return;
403 
404 	if (local->ops->remain_on_channel) {
405 		_ieee80211_start_next_roc(local);
406 	} else {
407 		/* delay it a bit */
408 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work,
409 					 round_jiffies_relative(HZ / 2));
410 	}
411 }
412 
413 static void __ieee80211_roc_work(struct ieee80211_local *local)
414 {
415 	struct ieee80211_roc_work *roc;
416 	bool on_channel;
417 
418 	lockdep_assert_wiphy(local->hw.wiphy);
419 
420 	if (WARN_ON(local->ops->remain_on_channel))
421 		return;
422 
423 	roc = list_first_entry_or_null(&local->roc_list,
424 				       struct ieee80211_roc_work, list);
425 	if (!roc)
426 		return;
427 
428 	if (!roc->started) {
429 		WARN_ON(local->use_chanctx);
430 		_ieee80211_start_next_roc(local);
431 	} else {
432 		on_channel = roc->on_channel;
433 		if (ieee80211_recalc_sw_work(local, jiffies))
434 			return;
435 
436 		/* careful - roc pointer became invalid during recalc */
437 
438 		if (!on_channel) {
439 			ieee80211_flush_queues(local, NULL, false);
440 
441 			local->tmp_channel = NULL;
442 			ieee80211_hw_config(local, 0);
443 
444 			ieee80211_offchannel_return(local);
445 		}
446 
447 		ieee80211_recalc_idle(local);
448 		ieee80211_start_next_roc(local);
449 	}
450 }
451 
452 static void ieee80211_roc_work(struct wiphy *wiphy, struct wiphy_work *work)
453 {
454 	struct ieee80211_local *local =
455 		container_of(work, struct ieee80211_local, roc_work.work);
456 
457 	lockdep_assert_wiphy(local->hw.wiphy);
458 
459 	__ieee80211_roc_work(local);
460 }
461 
462 static void ieee80211_hw_roc_done(struct wiphy *wiphy, struct wiphy_work *work)
463 {
464 	struct ieee80211_local *local =
465 		container_of(work, struct ieee80211_local, hw_roc_done);
466 
467 	lockdep_assert_wiphy(local->hw.wiphy);
468 
469 	ieee80211_end_finished_rocs(local, jiffies);
470 
471 	/* if there's another roc, start it now */
472 	ieee80211_start_next_roc(local);
473 }
474 
475 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
476 {
477 	struct ieee80211_local *local = hw_to_local(hw);
478 
479 	trace_api_remain_on_channel_expired(local);
480 
481 	wiphy_work_queue(hw->wiphy, &local->hw_roc_done);
482 }
483 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
484 
485 static bool
486 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
487 				  struct ieee80211_roc_work *new_roc,
488 				  struct ieee80211_roc_work *cur_roc)
489 {
490 	unsigned long now = jiffies;
491 	unsigned long remaining;
492 
493 	if (WARN_ON(!cur_roc->started))
494 		return false;
495 
496 	/* if it was scheduled in the hardware, but not started yet,
497 	 * we can only combine if the older one had a longer duration
498 	 */
499 	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
500 		return false;
501 
502 	remaining = cur_roc->start_time +
503 		    msecs_to_jiffies(cur_roc->duration) -
504 		    now;
505 
506 	/* if it doesn't fit entirely, schedule a new one */
507 	if (new_roc->duration > jiffies_to_msecs(remaining))
508 		return false;
509 
510 	/* add just after the current one so we combine their finish later */
511 	list_add(&new_roc->list, &cur_roc->list);
512 
513 	/* if the existing one has already begun then let this one also
514 	 * begin, otherwise they'll both be marked properly by the work
515 	 * struct that runs once the driver notifies us of the beginning
516 	 */
517 	if (cur_roc->hw_begun) {
518 		new_roc->hw_begun = true;
519 		ieee80211_handle_roc_started(new_roc, now);
520 	}
521 
522 	return true;
523 }
524 
525 static int ieee80211_start_roc_work(struct ieee80211_local *local,
526 				    struct ieee80211_sub_if_data *sdata,
527 				    struct ieee80211_channel *channel,
528 				    unsigned int duration, u64 *cookie,
529 				    struct sk_buff *txskb,
530 				    enum ieee80211_roc_type type)
531 {
532 	struct ieee80211_roc_work *roc, *tmp;
533 	bool queued = false, combine_started = true;
534 	int ret;
535 
536 	lockdep_assert_wiphy(local->hw.wiphy);
537 
538 	if (channel->freq_offset)
539 		/* this may work, but is untested */
540 		return -EOPNOTSUPP;
541 
542 	if (local->use_chanctx && !local->ops->remain_on_channel)
543 		return -EOPNOTSUPP;
544 
545 	roc = kzalloc(sizeof(*roc), GFP_KERNEL);
546 	if (!roc)
547 		return -ENOMEM;
548 
549 	/*
550 	 * If the duration is zero, then the driver
551 	 * wouldn't actually do anything. Set it to
552 	 * 10 for now.
553 	 *
554 	 * TODO: cancel the off-channel operation
555 	 *       when we get the SKB's TX status and
556 	 *       the wait time was zero before.
557 	 */
558 	if (!duration)
559 		duration = 10;
560 
561 	roc->chan = channel;
562 	roc->duration = duration;
563 	roc->req_duration = duration;
564 	roc->frame = txskb;
565 	roc->type = type;
566 	roc->sdata = sdata;
567 
568 	/*
569 	 * cookie is either the roc cookie (for normal roc)
570 	 * or the SKB (for mgmt TX)
571 	 */
572 	if (!txskb) {
573 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
574 		*cookie = roc->cookie;
575 	} else {
576 		roc->mgmt_tx_cookie = *cookie;
577 	}
578 
579 	/* if there's no need to queue, handle it immediately */
580 	if (list_empty(&local->roc_list) &&
581 	    !local->scanning && !ieee80211_is_radar_required(local)) {
582 		/* if not HW assist, just queue & schedule work */
583 		if (!local->ops->remain_on_channel) {
584 			list_add_tail(&roc->list, &local->roc_list);
585 			wiphy_delayed_work_queue(local->hw.wiphy,
586 						 &local->roc_work, 0);
587 		} else {
588 			/* otherwise actually kick it off here
589 			 * (for error handling)
590 			 */
591 			ret = drv_remain_on_channel(local, sdata, channel,
592 						    duration, type);
593 			if (ret) {
594 				kfree(roc);
595 				return ret;
596 			}
597 			roc->started = true;
598 			list_add_tail(&roc->list, &local->roc_list);
599 		}
600 
601 		return 0;
602 	}
603 
604 	/* otherwise handle queueing */
605 
606 	list_for_each_entry(tmp, &local->roc_list, list) {
607 		if (tmp->chan != channel || tmp->sdata != sdata)
608 			continue;
609 
610 		/*
611 		 * Extend this ROC if possible: If it hasn't started, add
612 		 * just after the new one to combine.
613 		 */
614 		if (!tmp->started) {
615 			list_add(&roc->list, &tmp->list);
616 			queued = true;
617 			break;
618 		}
619 
620 		if (!combine_started)
621 			continue;
622 
623 		if (!local->ops->remain_on_channel) {
624 			/* If there's no hardware remain-on-channel, and
625 			 * doing so won't push us over the maximum r-o-c
626 			 * we allow, then we can just add the new one to
627 			 * the list and mark it as having started now.
628 			 * If it would push over the limit, don't try to
629 			 * combine with other started ones (that haven't
630 			 * been running as long) but potentially sort it
631 			 * with others that had the same fate.
632 			 */
633 			unsigned long now = jiffies;
634 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
635 			struct wiphy *wiphy = local->hw.wiphy;
636 			u32 max_roc = wiphy->max_remain_on_channel_duration;
637 
638 			if (elapsed + roc->duration > max_roc) {
639 				combine_started = false;
640 				continue;
641 			}
642 
643 			list_add(&roc->list, &tmp->list);
644 			queued = true;
645 			roc->on_channel = tmp->on_channel;
646 			ieee80211_handle_roc_started(roc, now);
647 			ieee80211_recalc_sw_work(local, now);
648 			break;
649 		}
650 
651 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
652 		if (queued)
653 			break;
654 		/* if it wasn't queued, perhaps it can be combined with
655 		 * another that also couldn't get combined previously,
656 		 * but no need to check for already started ones, since
657 		 * that can't work.
658 		 */
659 		combine_started = false;
660 	}
661 
662 	if (!queued)
663 		list_add_tail(&roc->list, &local->roc_list);
664 
665 	return 0;
666 }
667 
668 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
669 				struct ieee80211_channel *chan,
670 				unsigned int duration, u64 *cookie)
671 {
672 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
673 	struct ieee80211_local *local = sdata->local;
674 
675 	lockdep_assert_wiphy(local->hw.wiphy);
676 
677 	return ieee80211_start_roc_work(local, sdata, chan,
678 					duration, cookie, NULL,
679 					IEEE80211_ROC_TYPE_NORMAL);
680 }
681 
682 static int ieee80211_cancel_roc(struct ieee80211_local *local,
683 				u64 cookie, bool mgmt_tx)
684 {
685 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
686 	int ret;
687 
688 	lockdep_assert_wiphy(local->hw.wiphy);
689 
690 	if (!cookie)
691 		return -ENOENT;
692 
693 	wiphy_work_flush(local->hw.wiphy, &local->hw_roc_start);
694 
695 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
696 		if (!mgmt_tx && roc->cookie != cookie)
697 			continue;
698 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
699 			continue;
700 
701 		found = roc;
702 		break;
703 	}
704 
705 	if (!found) {
706 		return -ENOENT;
707 	}
708 
709 	if (!found->started) {
710 		ieee80211_roc_notify_destroy(found);
711 		goto out_unlock;
712 	}
713 
714 	if (local->ops->remain_on_channel) {
715 		ret = drv_cancel_remain_on_channel(local, roc->sdata);
716 		if (WARN_ON_ONCE(ret)) {
717 			return ret;
718 		}
719 
720 		/*
721 		 * We could be racing against the notification from the driver:
722 		 *  + driver is handling the notification on CPU0
723 		 *  + user space is cancelling the remain on channel and
724 		 *    schedules the hw_roc_done worker.
725 		 *
726 		 *  Now hw_roc_done might start to run after the next roc will
727 		 *  start and mac80211 will think that this second roc has
728 		 *  ended prematurely.
729 		 *  Cancel the work to make sure that all the pending workers
730 		 *  have completed execution.
731 		 *  Note that this assumes that by the time the driver returns
732 		 *  from drv_cancel_remain_on_channel, it has completed all
733 		 *  the processing of related notifications.
734 		 */
735 		wiphy_work_cancel(local->hw.wiphy, &local->hw_roc_done);
736 
737 		/* TODO:
738 		 * if multiple items were combined here then we really shouldn't
739 		 * cancel them all - we should wait for as much time as needed
740 		 * for the longest remaining one, and only then cancel ...
741 		 */
742 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
743 			if (!roc->started)
744 				break;
745 			if (roc == found)
746 				found = NULL;
747 			ieee80211_roc_notify_destroy(roc);
748 		}
749 
750 		/* that really must not happen - it was started */
751 		WARN_ON(found);
752 
753 		ieee80211_start_next_roc(local);
754 	} else {
755 		/* go through work struct to return to the operating channel */
756 		found->abort = true;
757 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work, 0);
758 	}
759 
760  out_unlock:
761 
762 	return 0;
763 }
764 
765 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
766 				       struct wireless_dev *wdev, u64 cookie)
767 {
768 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
769 	struct ieee80211_local *local = sdata->local;
770 
771 	return ieee80211_cancel_roc(local, cookie, false);
772 }
773 
774 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
775 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
776 {
777 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
778 	struct ieee80211_local *local = sdata->local;
779 	struct sk_buff *skb;
780 	struct sta_info *sta = NULL;
781 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
782 	bool need_offchan = false;
783 	bool mlo_sta = false;
784 	int link_id = -1;
785 	u32 flags;
786 	int ret;
787 	u8 *data;
788 
789 	lockdep_assert_wiphy(local->hw.wiphy);
790 
791 	if (params->dont_wait_for_ack)
792 		flags = IEEE80211_TX_CTL_NO_ACK;
793 	else
794 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
795 			IEEE80211_TX_CTL_REQ_TX_STATUS;
796 
797 	if (params->no_cck)
798 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
799 
800 	switch (sdata->vif.type) {
801 	case NL80211_IFTYPE_ADHOC:
802 		if (!sdata->vif.cfg.ibss_joined)
803 			need_offchan = true;
804 #ifdef CONFIG_MAC80211_MESH
805 		fallthrough;
806 	case NL80211_IFTYPE_MESH_POINT:
807 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
808 		    !sdata->u.mesh.mesh_id_len)
809 			need_offchan = true;
810 #endif
811 		fallthrough;
812 	case NL80211_IFTYPE_AP:
813 	case NL80211_IFTYPE_AP_VLAN:
814 	case NL80211_IFTYPE_P2P_GO:
815 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
816 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
817 		    !sdata->bss->active)
818 			need_offchan = true;
819 
820 		rcu_read_lock();
821 		sta = sta_info_get_bss(sdata, mgmt->da);
822 		mlo_sta = sta && sta->sta.mlo;
823 
824 		if (!ieee80211_is_action(mgmt->frame_control) ||
825 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
826 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
827 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
828 			rcu_read_unlock();
829 			break;
830 		}
831 
832 		if (!sta) {
833 			rcu_read_unlock();
834 			return -ENOLINK;
835 		}
836 		if (params->link_id >= 0 &&
837 		    !(sta->sta.valid_links & BIT(params->link_id))) {
838 			rcu_read_unlock();
839 			return -ENOLINK;
840 		}
841 		link_id = params->link_id;
842 		rcu_read_unlock();
843 		break;
844 	case NL80211_IFTYPE_STATION:
845 	case NL80211_IFTYPE_P2P_CLIENT:
846 		if (!sdata->u.mgd.associated ||
847 		    (params->offchan && params->wait &&
848 		     local->ops->remain_on_channel &&
849 		     memcmp(sdata->vif.cfg.ap_addr, mgmt->bssid, ETH_ALEN))) {
850 			need_offchan = true;
851 		} else if (sdata->u.mgd.associated &&
852 			   ether_addr_equal(sdata->vif.cfg.ap_addr, mgmt->da)) {
853 			sta = sta_info_get_bss(sdata, mgmt->da);
854 			mlo_sta = sta && sta->sta.mlo;
855 		}
856 		break;
857 	case NL80211_IFTYPE_P2P_DEVICE:
858 		need_offchan = true;
859 		break;
860 	case NL80211_IFTYPE_NAN:
861 	default:
862 		return -EOPNOTSUPP;
863 	}
864 
865 	/* configurations requiring offchan cannot work if no channel has been
866 	 * specified
867 	 */
868 	if (need_offchan && !params->chan)
869 		return -EINVAL;
870 
871 	/* Check if the operating channel is the requested channel */
872 	if (!params->chan && mlo_sta) {
873 		need_offchan = false;
874 	} else if (!need_offchan) {
875 		struct ieee80211_chanctx_conf *chanctx_conf = NULL;
876 		int i;
877 
878 		rcu_read_lock();
879 		/* Check all the links first */
880 		for (i = 0; i < ARRAY_SIZE(sdata->vif.link_conf); i++) {
881 			struct ieee80211_bss_conf *conf;
882 
883 			conf = rcu_dereference(sdata->vif.link_conf[i]);
884 			if (!conf)
885 				continue;
886 
887 			chanctx_conf = rcu_dereference(conf->chanctx_conf);
888 			if (!chanctx_conf)
889 				continue;
890 
891 			if (mlo_sta && params->chan == chanctx_conf->def.chan &&
892 			    ether_addr_equal(sdata->vif.addr, mgmt->sa)) {
893 				link_id = i;
894 				break;
895 			}
896 
897 			if (ether_addr_equal(conf->addr, mgmt->sa))
898 				break;
899 
900 			chanctx_conf = NULL;
901 		}
902 
903 		if (chanctx_conf) {
904 			need_offchan = params->chan &&
905 				       (params->chan !=
906 					chanctx_conf->def.chan);
907 		} else {
908 			need_offchan = true;
909 		}
910 		rcu_read_unlock();
911 	}
912 
913 	if (need_offchan && !params->offchan) {
914 		ret = -EBUSY;
915 		goto out_unlock;
916 	}
917 
918 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
919 	if (!skb) {
920 		ret = -ENOMEM;
921 		goto out_unlock;
922 	}
923 	skb_reserve(skb, local->hw.extra_tx_headroom);
924 
925 	data = skb_put_data(skb, params->buf, params->len);
926 
927 	/* Update CSA counters */
928 	if (sdata->vif.bss_conf.csa_active &&
929 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
930 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
931 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
932 	    params->n_csa_offsets) {
933 		int i;
934 		struct beacon_data *beacon = NULL;
935 
936 		rcu_read_lock();
937 
938 		if (sdata->vif.type == NL80211_IFTYPE_AP)
939 			beacon = rcu_dereference(sdata->deflink.u.ap.beacon);
940 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
941 			beacon = rcu_dereference(sdata->u.ibss.presp);
942 		else if (ieee80211_vif_is_mesh(&sdata->vif))
943 			beacon = rcu_dereference(sdata->u.mesh.beacon);
944 
945 		if (beacon)
946 			for (i = 0; i < params->n_csa_offsets; i++)
947 				data[params->csa_offsets[i]] =
948 					beacon->cntdwn_current_counter;
949 
950 		rcu_read_unlock();
951 	}
952 
953 	IEEE80211_SKB_CB(skb)->flags = flags;
954 
955 	skb->dev = sdata->dev;
956 
957 	if (!params->dont_wait_for_ack) {
958 		/* make a copy to preserve the frame contents
959 		 * in case of encryption.
960 		 */
961 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
962 		if (ret) {
963 			kfree_skb(skb);
964 			goto out_unlock;
965 		}
966 	} else {
967 		/* Assign a dummy non-zero cookie, it's not sent to
968 		 * userspace in this case but we rely on its value
969 		 * internally in the need_offchan case to distinguish
970 		 * mgmt-tx from remain-on-channel.
971 		 */
972 		*cookie = 0xffffffff;
973 	}
974 
975 	if (!need_offchan) {
976 		ieee80211_tx_skb_tid(sdata, skb, 7, link_id);
977 		ret = 0;
978 		goto out_unlock;
979 	}
980 
981 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
982 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
983 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
984 		IEEE80211_SKB_CB(skb)->hw_queue =
985 			local->hw.offchannel_tx_hw_queue;
986 
987 	/* This will handle all kinds of coalescing and immediate TX */
988 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
989 				       params->wait, cookie, skb,
990 				       IEEE80211_ROC_TYPE_MGMT_TX);
991 	if (ret)
992 		ieee80211_free_txskb(&local->hw, skb);
993  out_unlock:
994 	return ret;
995 }
996 
997 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
998 				  struct wireless_dev *wdev, u64 cookie)
999 {
1000 	struct ieee80211_local *local = wiphy_priv(wiphy);
1001 
1002 	return ieee80211_cancel_roc(local, cookie, true);
1003 }
1004 
1005 void ieee80211_roc_setup(struct ieee80211_local *local)
1006 {
1007 	wiphy_work_init(&local->hw_roc_start, ieee80211_hw_roc_start);
1008 	wiphy_work_init(&local->hw_roc_done, ieee80211_hw_roc_done);
1009 	wiphy_delayed_work_init(&local->roc_work, ieee80211_roc_work);
1010 	INIT_LIST_HEAD(&local->roc_list);
1011 }
1012 
1013 void ieee80211_roc_purge(struct ieee80211_local *local,
1014 			 struct ieee80211_sub_if_data *sdata)
1015 {
1016 	struct ieee80211_roc_work *roc, *tmp;
1017 	bool work_to_do = false;
1018 
1019 	lockdep_assert_wiphy(local->hw.wiphy);
1020 
1021 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
1022 		if (sdata && roc->sdata != sdata)
1023 			continue;
1024 
1025 		if (roc->started) {
1026 			if (local->ops->remain_on_channel) {
1027 				/* can race, so ignore return value */
1028 				drv_cancel_remain_on_channel(local, roc->sdata);
1029 				ieee80211_roc_notify_destroy(roc);
1030 			} else {
1031 				roc->abort = true;
1032 				work_to_do = true;
1033 			}
1034 		} else {
1035 			ieee80211_roc_notify_destroy(roc);
1036 		}
1037 	}
1038 	if (work_to_do)
1039 		__ieee80211_roc_work(local);
1040 }
1041