xref: /linux/net/mac80211/offchannel.c (revision b693b51e0829b96a5c43f45c3fba3d11f6f09d2f)
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, 2022-2026 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 	timer_delete_sync(&local->dynamic_ps_timer);
34 	timer_delete_sync(&ifmgd->bcn_mon_timer);
35 	timer_delete_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, -1, 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->emulate_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->emulate_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 		 * Note: scan can't run, tmp_channel is what we use, so this
356 		 * must be the currently active channel.
357 		 */
358 		roc->on_channel = roc->chan == local->hw.conf.chandef.chan;
359 
360 		/* start this ROC */
361 		ieee80211_recalc_idle(local);
362 
363 		if (!roc->on_channel) {
364 			ieee80211_offchannel_stop_vifs(local);
365 
366 			local->tmp_channel = roc->chan;
367 			ieee80211_hw_conf_chan(local);
368 		}
369 
370 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work,
371 					 msecs_to_jiffies(min_dur));
372 
373 		/* tell userspace or send frame(s) */
374 		list_for_each_entry(tmp, &local->roc_list, list) {
375 			if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
376 				break;
377 
378 			tmp->on_channel = roc->on_channel;
379 			ieee80211_handle_roc_started(tmp, jiffies);
380 		}
381 	}
382 }
383 
384 void ieee80211_start_next_roc(struct ieee80211_local *local)
385 {
386 	struct ieee80211_roc_work *roc;
387 
388 	lockdep_assert_wiphy(local->hw.wiphy);
389 
390 	if (list_empty(&local->roc_list)) {
391 		ieee80211_run_deferred_scan(local);
392 		return;
393 	}
394 
395 	/* defer roc if driver is not started (i.e. during reconfig) */
396 	if (local->in_reconfig)
397 		return;
398 
399 	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
400 			       list);
401 
402 	if (WARN_ON_ONCE(roc->started))
403 		return;
404 
405 	if (local->ops->remain_on_channel) {
406 		_ieee80211_start_next_roc(local);
407 	} else {
408 		/* delay it a bit */
409 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work,
410 					 round_jiffies_relative(HZ / 2));
411 	}
412 }
413 
414 void ieee80211_reconfig_roc(struct ieee80211_local *local)
415 {
416 	struct ieee80211_roc_work *roc, *tmp;
417 
418 	/*
419 	 * In the software implementation can just continue with the
420 	 * interruption due to reconfig, roc_work is still queued if
421 	 * needed.
422 	 */
423 	if (!local->ops->remain_on_channel)
424 		return;
425 
426 	/* flush work so nothing from the driver is still pending */
427 	wiphy_work_flush(local->hw.wiphy, &local->hw_roc_start);
428 	wiphy_work_flush(local->hw.wiphy, &local->hw_roc_done);
429 
430 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
431 		if (!roc->started)
432 			break;
433 
434 		if (!roc->hw_begun) {
435 			/* it didn't start in HW yet, so we can restart it */
436 			roc->started = false;
437 			continue;
438 		}
439 
440 		/* otherwise destroy it and tell userspace */
441 		ieee80211_roc_notify_destroy(roc);
442 	}
443 
444 	ieee80211_start_next_roc(local);
445 }
446 
447 static void __ieee80211_roc_work(struct ieee80211_local *local)
448 {
449 	struct ieee80211_roc_work *roc;
450 	bool on_channel;
451 
452 	lockdep_assert_wiphy(local->hw.wiphy);
453 
454 	if (WARN_ON(local->ops->remain_on_channel))
455 		return;
456 
457 	roc = list_first_entry_or_null(&local->roc_list,
458 				       struct ieee80211_roc_work, list);
459 	if (!roc)
460 		return;
461 
462 	if (!roc->started) {
463 		WARN_ON(!local->emulate_chanctx);
464 		_ieee80211_start_next_roc(local);
465 	} else {
466 		on_channel = roc->on_channel;
467 		if (ieee80211_recalc_sw_work(local, jiffies))
468 			return;
469 
470 		/* careful - roc pointer became invalid during recalc */
471 
472 		if (!on_channel) {
473 			ieee80211_flush_queues(local, NULL, false);
474 
475 			local->tmp_channel = NULL;
476 			ieee80211_hw_conf_chan(local);
477 
478 			ieee80211_offchannel_return(local);
479 		}
480 
481 		ieee80211_recalc_idle(local);
482 		ieee80211_start_next_roc(local);
483 	}
484 }
485 
486 static void ieee80211_roc_work(struct wiphy *wiphy, struct wiphy_work *work)
487 {
488 	struct ieee80211_local *local =
489 		container_of(work, struct ieee80211_local, roc_work.work);
490 
491 	lockdep_assert_wiphy(local->hw.wiphy);
492 
493 	__ieee80211_roc_work(local);
494 }
495 
496 static void ieee80211_hw_roc_done(struct wiphy *wiphy, struct wiphy_work *work)
497 {
498 	struct ieee80211_local *local =
499 		container_of(work, struct ieee80211_local, hw_roc_done);
500 
501 	lockdep_assert_wiphy(local->hw.wiphy);
502 
503 	ieee80211_end_finished_rocs(local, jiffies);
504 
505 	/* if there's another roc, start it now */
506 	ieee80211_start_next_roc(local);
507 }
508 
509 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
510 {
511 	struct ieee80211_local *local = hw_to_local(hw);
512 
513 	trace_api_remain_on_channel_expired(local);
514 
515 	wiphy_work_queue(hw->wiphy, &local->hw_roc_done);
516 }
517 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
518 
519 static bool
520 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
521 				  struct ieee80211_roc_work *new_roc,
522 				  struct ieee80211_roc_work *cur_roc)
523 {
524 	unsigned long now = jiffies;
525 	unsigned long remaining;
526 
527 	if (WARN_ON(!cur_roc->started))
528 		return false;
529 
530 	/* if it was scheduled in the hardware, but not started yet,
531 	 * we can only combine if the older one had a longer duration
532 	 */
533 	if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
534 		return false;
535 
536 	remaining = cur_roc->start_time +
537 		    msecs_to_jiffies(cur_roc->duration) -
538 		    now;
539 
540 	/* if it doesn't fit entirely, schedule a new one */
541 	if (new_roc->duration > jiffies_to_msecs(remaining))
542 		return false;
543 
544 	/* add just after the current one so we combine their finish later */
545 	list_add(&new_roc->list, &cur_roc->list);
546 
547 	/* if the existing one has already begun then let this one also
548 	 * begin, otherwise they'll both be marked properly by the work
549 	 * struct that runs once the driver notifies us of the beginning
550 	 */
551 	if (cur_roc->hw_begun) {
552 		new_roc->hw_begun = true;
553 		ieee80211_handle_roc_started(new_roc, now);
554 	}
555 
556 	return true;
557 }
558 
559 static int ieee80211_start_roc_work(struct ieee80211_local *local,
560 				    struct ieee80211_sub_if_data *sdata,
561 				    struct ieee80211_channel *channel,
562 				    unsigned int duration, u64 *cookie,
563 				    struct sk_buff *txskb,
564 				    enum ieee80211_roc_type type)
565 {
566 	struct ieee80211_roc_work *roc, *tmp;
567 	bool queued = false, combine_started = true;
568 	struct cfg80211_scan_request *req;
569 	int ret;
570 
571 	lockdep_assert_wiphy(local->hw.wiphy);
572 
573 	if (channel->freq_offset)
574 		/* this may work, but is untested */
575 		return -EOPNOTSUPP;
576 
577 	if (!local->emulate_chanctx && !local->ops->remain_on_channel)
578 		return -EOPNOTSUPP;
579 
580 	roc = kzalloc_obj(*roc);
581 	if (!roc)
582 		return -ENOMEM;
583 
584 	/*
585 	 * If the duration is zero, then the driver
586 	 * wouldn't actually do anything. Set it to
587 	 * 10 for now.
588 	 *
589 	 * TODO: cancel the off-channel operation
590 	 *       when we get the SKB's TX status and
591 	 *       the wait time was zero before.
592 	 */
593 	if (!duration)
594 		duration = 10;
595 
596 	roc->chan = channel;
597 	roc->duration = duration;
598 	roc->req_duration = duration;
599 	roc->frame = txskb;
600 	roc->type = type;
601 	roc->sdata = sdata;
602 
603 	/*
604 	 * cookie is either the roc cookie (for normal roc)
605 	 * or the SKB (for mgmt TX)
606 	 */
607 	if (!txskb) {
608 		roc->cookie = ieee80211_mgmt_tx_cookie(local);
609 		*cookie = roc->cookie;
610 	} else {
611 		roc->mgmt_tx_cookie = *cookie;
612 	}
613 
614 	req = wiphy_dereference(local->hw.wiphy, local->scan_req);
615 
616 	/* if there's no need to queue, handle it immediately */
617 	if (list_empty(&local->roc_list) &&
618 	    !local->scanning && !ieee80211_is_radar_required(local, req)) {
619 		/* if not HW assist, just queue & schedule work */
620 		if (!local->ops->remain_on_channel) {
621 			list_add_tail(&roc->list, &local->roc_list);
622 			wiphy_delayed_work_queue(local->hw.wiphy,
623 						 &local->roc_work, 0);
624 		} else {
625 			/* otherwise actually kick it off here
626 			 * (for error handling)
627 			 */
628 			ret = drv_remain_on_channel(local, sdata, channel,
629 						    duration, type);
630 			if (ret) {
631 				kfree(roc);
632 				return ret;
633 			}
634 			roc->started = true;
635 			list_add_tail(&roc->list, &local->roc_list);
636 		}
637 
638 		return 0;
639 	}
640 
641 	/* otherwise handle queueing */
642 
643 	list_for_each_entry(tmp, &local->roc_list, list) {
644 		if (tmp->chan != channel || tmp->sdata != sdata)
645 			continue;
646 
647 		/*
648 		 * Extend this ROC if possible: If it hasn't started, add
649 		 * just after the new one to combine.
650 		 */
651 		if (!tmp->started) {
652 			list_add(&roc->list, &tmp->list);
653 			queued = true;
654 			break;
655 		}
656 
657 		if (!combine_started)
658 			continue;
659 
660 		if (!local->ops->remain_on_channel) {
661 			/* If there's no hardware remain-on-channel, and
662 			 * doing so won't push us over the maximum r-o-c
663 			 * we allow, then we can just add the new one to
664 			 * the list and mark it as having started now.
665 			 * If it would push over the limit, don't try to
666 			 * combine with other started ones (that haven't
667 			 * been running as long) but potentially sort it
668 			 * with others that had the same fate.
669 			 */
670 			unsigned long now = jiffies;
671 			u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
672 			struct wiphy *wiphy = local->hw.wiphy;
673 			u32 max_roc = wiphy->max_remain_on_channel_duration;
674 
675 			if (elapsed + roc->duration > max_roc) {
676 				combine_started = false;
677 				continue;
678 			}
679 
680 			list_add(&roc->list, &tmp->list);
681 			queued = true;
682 			roc->on_channel = tmp->on_channel;
683 			ieee80211_handle_roc_started(roc, now);
684 			ieee80211_recalc_sw_work(local, now);
685 			break;
686 		}
687 
688 		queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
689 		if (queued)
690 			break;
691 		/* if it wasn't queued, perhaps it can be combined with
692 		 * another that also couldn't get combined previously,
693 		 * but no need to check for already started ones, since
694 		 * that can't work.
695 		 */
696 		combine_started = false;
697 	}
698 
699 	if (!queued)
700 		list_add_tail(&roc->list, &local->roc_list);
701 
702 	return 0;
703 }
704 
705 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
706 				struct ieee80211_channel *chan,
707 				unsigned int duration, u64 *cookie,
708 				const u8 *rx_addr)
709 {
710 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
711 	struct ieee80211_local *local = sdata->local;
712 
713 	lockdep_assert_wiphy(local->hw.wiphy);
714 
715 	return ieee80211_start_roc_work(local, sdata, chan,
716 					duration, cookie, NULL,
717 					IEEE80211_ROC_TYPE_NORMAL);
718 }
719 
720 static int ieee80211_cancel_roc(struct ieee80211_local *local,
721 				u64 cookie, bool mgmt_tx)
722 {
723 	struct ieee80211_roc_work *roc, *tmp, *found = NULL;
724 	int ret;
725 
726 	lockdep_assert_wiphy(local->hw.wiphy);
727 
728 	if (!cookie)
729 		return -ENOENT;
730 
731 	wiphy_work_flush(local->hw.wiphy, &local->hw_roc_start);
732 
733 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
734 		if (!mgmt_tx && roc->cookie != cookie)
735 			continue;
736 		else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
737 			continue;
738 
739 		found = roc;
740 		break;
741 	}
742 
743 	if (!found) {
744 		return -ENOENT;
745 	}
746 
747 	if (!found->started) {
748 		ieee80211_roc_notify_destroy(found);
749 		goto out_unlock;
750 	}
751 
752 	if (local->ops->remain_on_channel) {
753 		ret = drv_cancel_remain_on_channel(local, roc->sdata);
754 		if (WARN_ON_ONCE(ret)) {
755 			return ret;
756 		}
757 
758 		/*
759 		 * We could be racing against the notification from the driver:
760 		 *  + driver is handling the notification on CPU0
761 		 *  + user space is cancelling the remain on channel and
762 		 *    schedules the hw_roc_done worker.
763 		 *
764 		 *  Now hw_roc_done might start to run after the next roc will
765 		 *  start and mac80211 will think that this second roc has
766 		 *  ended prematurely.
767 		 *  Cancel the work to make sure that all the pending workers
768 		 *  have completed execution.
769 		 *  Note that this assumes that by the time the driver returns
770 		 *  from drv_cancel_remain_on_channel, it has completed all
771 		 *  the processing of related notifications.
772 		 */
773 		wiphy_work_cancel(local->hw.wiphy, &local->hw_roc_done);
774 
775 		/* TODO:
776 		 * if multiple items were combined here then we really shouldn't
777 		 * cancel them all - we should wait for as much time as needed
778 		 * for the longest remaining one, and only then cancel ...
779 		 */
780 		list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
781 			if (!roc->started)
782 				break;
783 			if (roc == found)
784 				found = NULL;
785 			ieee80211_roc_notify_destroy(roc);
786 		}
787 
788 		/* that really must not happen - it was started */
789 		WARN_ON(found);
790 
791 		ieee80211_start_next_roc(local);
792 	} else {
793 		/* go through work struct to return to the operating channel */
794 		found->abort = true;
795 		wiphy_delayed_work_queue(local->hw.wiphy, &local->roc_work, 0);
796 	}
797 
798  out_unlock:
799 
800 	return 0;
801 }
802 
803 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
804 				       struct wireless_dev *wdev, u64 cookie)
805 {
806 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
807 	struct ieee80211_local *local = sdata->local;
808 
809 	return ieee80211_cancel_roc(local, cookie, false);
810 }
811 
812 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
813 		      struct cfg80211_mgmt_tx_params *params, u64 *cookie)
814 {
815 	struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
816 	struct ieee80211_local *local = sdata->local;
817 	struct sk_buff *skb;
818 	struct sta_info *sta = NULL;
819 	const struct ieee80211_mgmt *mgmt = (void *)params->buf;
820 	bool need_offchan = false;
821 	bool mlo_sta = false;
822 	int link_id = -1;
823 	u32 flags;
824 	int ret;
825 	u8 *data;
826 
827 	lockdep_assert_wiphy(local->hw.wiphy);
828 
829 	if (params->dont_wait_for_ack)
830 		flags = IEEE80211_TX_CTL_NO_ACK;
831 	else
832 		flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
833 			IEEE80211_TX_CTL_REQ_TX_STATUS;
834 
835 	if (params->no_cck)
836 		flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
837 
838 	switch (sdata->vif.type) {
839 	case NL80211_IFTYPE_ADHOC:
840 		if (!sdata->vif.cfg.ibss_joined)
841 			need_offchan = true;
842 #ifdef CONFIG_MAC80211_MESH
843 		fallthrough;
844 	case NL80211_IFTYPE_MESH_POINT:
845 		if (ieee80211_vif_is_mesh(&sdata->vif) &&
846 		    !sdata->u.mesh.mesh_id_len)
847 			need_offchan = true;
848 #endif
849 		fallthrough;
850 	case NL80211_IFTYPE_AP:
851 	case NL80211_IFTYPE_AP_VLAN:
852 	case NL80211_IFTYPE_P2P_GO:
853 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
854 		    !ieee80211_vif_is_mesh(&sdata->vif) &&
855 		    !sdata->bss->active)
856 			need_offchan = true;
857 
858 		rcu_read_lock();
859 		sta = sta_info_get_bss(sdata, mgmt->da);
860 		mlo_sta = sta && sta->sta.mlo;
861 
862 		if (!ieee80211_is_action(mgmt->frame_control) ||
863 		    mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
864 		    mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
865 		    mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT) {
866 			rcu_read_unlock();
867 			break;
868 		}
869 
870 		if (!sta) {
871 			rcu_read_unlock();
872 			return -ENOLINK;
873 		}
874 		if (params->link_id >= 0 &&
875 		    !(sta->sta.valid_links & BIT(params->link_id))) {
876 			rcu_read_unlock();
877 			return -ENOLINK;
878 		}
879 		link_id = params->link_id;
880 		rcu_read_unlock();
881 		break;
882 	case NL80211_IFTYPE_STATION:
883 	case NL80211_IFTYPE_P2P_CLIENT:
884 		if (!sdata->u.mgd.associated ||
885 		    (params->offchan && params->wait &&
886 		     local->ops->remain_on_channel &&
887 		     memcmp(sdata->vif.cfg.ap_addr, mgmt->bssid, ETH_ALEN))) {
888 			need_offchan = true;
889 		} else if (sdata->u.mgd.associated &&
890 			   ether_addr_equal(sdata->vif.cfg.ap_addr, mgmt->da)) {
891 			sta = sta_info_get_bss(sdata, mgmt->da);
892 			mlo_sta = sta && sta->sta.mlo;
893 		}
894 		break;
895 	case NL80211_IFTYPE_P2P_DEVICE:
896 	case NL80211_IFTYPE_PD:
897 		need_offchan = true;
898 		break;
899 	case NL80211_IFTYPE_NAN:
900 		break;
901 	case NL80211_IFTYPE_NAN_DATA:
902 		if (is_multicast_ether_addr(mgmt->da))
903 			return -EOPNOTSUPP;
904 		break;
905 	default:
906 		return -EOPNOTSUPP;
907 	}
908 
909 	/* configurations requiring offchan cannot work if no channel has been
910 	 * specified
911 	 */
912 	if (need_offchan && !params->chan)
913 		return -EINVAL;
914 
915 	/* Check if the operating channel is the requested channel */
916 	if (!params->chan && mlo_sta) {
917 		need_offchan = false;
918 	} else if (sdata->vif.type == NL80211_IFTYPE_NAN ||
919 		   sdata->vif.type == NL80211_IFTYPE_NAN_DATA) {
920 		/* Frames can be sent during NAN schedule */
921 	} else if (!need_offchan) {
922 		struct ieee80211_chanctx_conf *chanctx_conf = NULL;
923 		int i;
924 
925 		rcu_read_lock();
926 		/* Check all the links first */
927 		for (i = 0; i < ARRAY_SIZE(sdata->vif.link_conf); i++) {
928 			struct ieee80211_bss_conf *conf;
929 
930 			conf = rcu_dereference(sdata->vif.link_conf[i]);
931 			if (!conf)
932 				continue;
933 
934 			chanctx_conf = rcu_dereference(conf->chanctx_conf);
935 			if (!chanctx_conf)
936 				continue;
937 
938 			if (mlo_sta && params->chan == chanctx_conf->def.chan &&
939 			    ether_addr_equal(sdata->vif.addr, mgmt->sa)) {
940 				link_id = i;
941 				break;
942 			}
943 
944 			if (ether_addr_equal(conf->addr, mgmt->sa)) {
945 				/* If userspace requested Tx on a specific link
946 				 * use the same link id if the link bss is matching
947 				 * the requested chan.
948 				 */
949 				if (sdata->vif.valid_links &&
950 				    params->link_id >= 0 && params->link_id == i &&
951 				    params->chan == chanctx_conf->def.chan)
952 					link_id = i;
953 
954 				break;
955 			}
956 
957 			chanctx_conf = NULL;
958 		}
959 
960 		if (chanctx_conf) {
961 			need_offchan = params->chan &&
962 				       (params->chan !=
963 					chanctx_conf->def.chan);
964 		} else {
965 			need_offchan = true;
966 		}
967 		rcu_read_unlock();
968 	}
969 
970 	if (need_offchan && !params->offchan) {
971 		ret = -EBUSY;
972 		goto out_unlock;
973 	}
974 
975 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
976 	if (!skb) {
977 		ret = -ENOMEM;
978 		goto out_unlock;
979 	}
980 	skb_reserve(skb, local->hw.extra_tx_headroom);
981 
982 	data = skb_put_data(skb, params->buf, params->len);
983 
984 	/* Update CSA counters */
985 	if (sdata->vif.bss_conf.csa_active &&
986 	    (sdata->vif.type == NL80211_IFTYPE_AP ||
987 	     sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
988 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
989 	    params->n_csa_offsets) {
990 		int i;
991 		struct beacon_data *beacon = NULL;
992 
993 		rcu_read_lock();
994 
995 		if (sdata->vif.type == NL80211_IFTYPE_AP)
996 			beacon = rcu_dereference(sdata->deflink.u.ap.beacon);
997 		else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
998 			beacon = rcu_dereference(sdata->u.ibss.presp);
999 		else if (ieee80211_vif_is_mesh(&sdata->vif))
1000 			beacon = rcu_dereference(sdata->u.mesh.beacon);
1001 
1002 		if (beacon)
1003 			for (i = 0; i < params->n_csa_offsets; i++)
1004 				data[params->csa_offsets[i]] =
1005 					beacon->cntdwn_current_counter;
1006 
1007 		rcu_read_unlock();
1008 	}
1009 
1010 	IEEE80211_SKB_CB(skb)->flags = flags;
1011 	IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
1012 
1013 	skb->dev = sdata->dev;
1014 
1015 	if (!params->dont_wait_for_ack) {
1016 		/* make a copy to preserve the frame contents
1017 		 * in case of encryption.
1018 		 */
1019 		ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
1020 		if (ret) {
1021 			kfree_skb(skb);
1022 			goto out_unlock;
1023 		}
1024 	} else {
1025 		/* Assign a dummy non-zero cookie, it's not sent to
1026 		 * userspace in this case but we rely on its value
1027 		 * internally in the need_offchan case to distinguish
1028 		 * mgmt-tx from remain-on-channel.
1029 		 */
1030 		*cookie = 0xffffffff;
1031 	}
1032 
1033 	if (!need_offchan) {
1034 		ieee80211_tx_skb_tid(sdata, skb, 7, link_id);
1035 		ret = 0;
1036 		goto out_unlock;
1037 	}
1038 
1039 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
1040 					IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
1041 	if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
1042 		IEEE80211_SKB_CB(skb)->hw_queue =
1043 			local->hw.offchannel_tx_hw_queue;
1044 
1045 	/* This will handle all kinds of coalescing and immediate TX */
1046 	ret = ieee80211_start_roc_work(local, sdata, params->chan,
1047 				       params->wait, cookie, skb,
1048 				       IEEE80211_ROC_TYPE_MGMT_TX);
1049 	if (ret)
1050 		ieee80211_free_txskb(&local->hw, skb);
1051  out_unlock:
1052 	return ret;
1053 }
1054 
1055 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
1056 				  struct wireless_dev *wdev, u64 cookie)
1057 {
1058 	struct ieee80211_local *local = wiphy_priv(wiphy);
1059 
1060 	return ieee80211_cancel_roc(local, cookie, true);
1061 }
1062 
1063 void ieee80211_roc_setup(struct ieee80211_local *local)
1064 {
1065 	wiphy_work_init(&local->hw_roc_start, ieee80211_hw_roc_start);
1066 	wiphy_work_init(&local->hw_roc_done, ieee80211_hw_roc_done);
1067 	wiphy_delayed_work_init(&local->roc_work, ieee80211_roc_work);
1068 	INIT_LIST_HEAD(&local->roc_list);
1069 }
1070 
1071 void ieee80211_roc_purge(struct ieee80211_local *local,
1072 			 struct ieee80211_sub_if_data *sdata)
1073 {
1074 	struct ieee80211_roc_work *roc, *tmp;
1075 	bool work_to_do = false;
1076 
1077 	lockdep_assert_wiphy(local->hw.wiphy);
1078 
1079 	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
1080 		if (sdata && roc->sdata != sdata)
1081 			continue;
1082 
1083 		if (roc->started) {
1084 			if (local->ops->remain_on_channel) {
1085 				/* can race, so ignore return value */
1086 				drv_cancel_remain_on_channel(local, roc->sdata);
1087 				ieee80211_roc_notify_destroy(roc);
1088 			} else {
1089 				roc->abort = true;
1090 				work_to_do = true;
1091 			}
1092 		} else {
1093 			ieee80211_roc_notify_destroy(roc);
1094 		}
1095 	}
1096 	if (work_to_do)
1097 		__ieee80211_roc_work(local);
1098 }
1099