summaryrefslogtreecommitdiffstats
path: root/net/mac80211/offchannel.c
blob: 430bd254e49693bf7e62744843fff8c10a2acb9a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
/*
 * Off-channel operation helpers
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"

/*
 * Tell our hardware to disable PS.
 * Optionally inform AP that we will go to sleep so that it will buffer
 * the frames while we are doing off-channel work.  This is optional
 * because we *may* be doing work on-operating channel, and want our
 * hardware unconditionally awake, but still let the AP send us normal frames.
 */
static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;

	local->offchannel_ps_enabled = false;

	/* FIXME: what to do when local->pspolling is true? */

	del_timer_sync(&local->dynamic_ps_timer);
	del_timer_sync(&ifmgd->bcn_mon_timer);
	del_timer_sync(&ifmgd->conn_mon_timer);

	cancel_work_sync(&local->dynamic_ps_enable_work);

	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
		local->offchannel_ps_enabled = true;
		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	}

	if (!local->offchannel_ps_enabled ||
	    !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
		/*
		 * If power save was enabled, no need to send a nullfunc
		 * frame because AP knows that we are sleeping. But if the
		 * hardware is creating the nullfunc frame for power save
		 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
		 * enabled) and power save was enabled, the firmware just
		 * sent a null frame with power save disabled. So we need
		 * to send a new nullfunc frame to inform the AP that we
		 * are again sleeping.
		 */
		ieee80211_send_nullfunc(local, sdata, 1);
}

/* inform AP that we are awake again, unless power save is enabled */
static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;

	if (!local->ps_sdata)
		ieee80211_send_nullfunc(local, sdata, 0);
	else if (local->offchannel_ps_enabled) {
		/*
		 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
		 * will send a nullfunc frame with the powersave bit set
		 * even though the AP already knows that we are sleeping.
		 * This could be avoided by sending a null frame with power
		 * save bit disabled before enabling the power save, but
		 * this doesn't gain anything.
		 *
		 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
		 * to send a nullfunc frame because AP already knows that
		 * we are sleeping, let's just enable power save mode in
		 * hardware.
		 */
		/* TODO:  Only set hardware if CONF_PS changed?
		 * TODO:  Should we set offchannel_ps_enabled to false?
		 */
		local->hw.conf.flags |= IEEE80211_CONF_PS;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	} else if (local->hw.conf.dynamic_ps_timeout > 0) {
		/*
		 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
		 * had been running before leaving the operating channel,
		 * restart the timer now and send a nullfunc frame to inform
		 * the AP that we are awake.
		 */
		ieee80211_send_nullfunc(local, sdata, 0);
		mod_timer(&local->dynamic_ps_timer, jiffies +
			  msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
	}

	ieee80211_sta_reset_beacon_monitor(sdata);
	ieee80211_sta_reset_conn_monitor(sdata);
}

void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	if (WARN_ON(local->use_chanctx))
		return;

	/*
	 * notify the AP about us leaving the channel and stop all
	 * STA interfaces.
	 */

	/*
	 * Stop queues and transmit all frames queued by the driver
	 * before sending nullfunc to enable powersave at the AP.
	 */
	ieee80211_stop_queues_by_reason(&local->hw,
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL);
	drv_flush(local, false);

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(sdata))
			continue;

		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
			continue;

		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);

		/* Check to see if we should disable beaconing. */
		if (sdata->vif.bss_conf.enable_beacon) {
			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
				&sdata->state);
			sdata->vif.bss_conf.enable_beacon = false;
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);
		}

		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    sdata->u.mgd.associated)
			ieee80211_offchannel_ps_enable(sdata);
	}
	mutex_unlock(&local->iflist_mtx);
}

void ieee80211_offchannel_return(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	if (WARN_ON(local->use_chanctx))
		return;

	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
			continue;

		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);

		if (!ieee80211_sdata_running(sdata))
			continue;

		/* Tell AP we're back */
		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    sdata->u.mgd.associated)
			ieee80211_offchannel_ps_disable(sdata);

		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
				       &sdata->state)) {
			sdata->vif.bss_conf.enable_beacon = true;
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);
		}
	}
	mutex_unlock(&local->iflist_mtx);

	ieee80211_wake_queues_by_reason(&local->hw,
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL);
}

void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
{
	if (roc->notified)
		return;

	if (roc->mgmt_tx_cookie) {
		if (!WARN_ON(!roc->frame)) {
			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
						  roc->chan->band);
			roc->frame = NULL;
		}
	} else {
		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
					  roc->chan, roc->req_duration,
					  GFP_KERNEL);
	}

	roc->notified = true;
}

static void ieee80211_hw_roc_start(struct work_struct *work)
{
	struct ieee80211_local *local =
		container_of(work, struct ieee80211_local, hw_roc_start);
	struct ieee80211_roc_work *roc, *dep, *tmp;

	mutex_lock(&local->mtx);

	if (list_empty(&local->roc_list))
		goto out_unlock;

	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
			       list);

	if (!roc->started)
		goto out_unlock;

	roc->hw_begun = true;
	roc->hw_start_time = local->hw_roc_start_time;

	ieee80211_handle_roc_started(roc);
	list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
		ieee80211_handle_roc_started(dep);

		if (dep->duration > roc->duration) {
			u32 dur = dep->duration;
			dep->duration = dur - roc->duration;
			roc->duration = dur;
			list_move(&dep->list, &roc->list);
		}
	}
 out_unlock:
	mutex_unlock(&local->mtx);
}

void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
{
	struct ieee80211_local *local = hw_to_local(hw);

	local->hw_roc_start_time = jiffies;

	trace_api_ready_on_channel(local);

	ieee80211_queue_work(hw, &local->hw_roc_start);
}
EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);

void ieee80211_start_next_roc(struct ieee80211_local *local)
{
	struct ieee80211_roc_work *roc;

	lockdep_assert_held(&local->mtx);

	if (list_empty(&local->roc_list)) {
		ieee80211_run_deferred_scan(local);
		return;
	}

	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
			       list);

	if (WARN_ON_ONCE(roc->started))
		return;

	if (local->ops->remain_on_channel) {
		int ret, duration = roc->duration;

		/* XXX: duplicated, see ieee80211_start_roc_work() */
		if (!duration)
			duration = 10;

		ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
					    duration);

		roc->started = true;

		if (ret) {
			wiphy_warn(local->hw.wiphy,
				   "failed to start next HW ROC (%d)\n", ret);
			/*
			 * queue the work struct again to avoid recursion
			 * when multiple failures occur
			 */
			ieee80211_remain_on_channel_expired(&local->hw);
		}
	} else {
		/* delay it a bit */
		ieee80211_queue_delayed_work(&local->hw, &roc->work,
					     round_jiffies_relative(HZ/2));
	}
}

void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
{
	struct ieee80211_roc_work *dep, *tmp;

	if (WARN_ON(roc->to_be_freed))
		return;

	/* was never transmitted */
	if (roc->frame) {
		cfg80211_mgmt_tx_status(&roc->sdata->wdev,
					(unsigned long)roc->frame,
					roc->frame->data, roc->frame->len,
					false, GFP_KERNEL);
		kfree_skb(roc->frame);
	}

	if (!roc->mgmt_tx_cookie)
		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
						   roc->cookie, roc->chan,
						   GFP_KERNEL);

	list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
		ieee80211_roc_notify_destroy(dep, true);

	if (free)
		kfree(roc);
	else
		roc->to_be_freed = true;
}

void ieee80211_sw_roc_work(struct work_struct *work)
{
	struct ieee80211_roc_work *roc =
		container_of(work, struct ieee80211_roc_work, work.work);
	struct ieee80211_sub_if_data *sdata = roc->sdata;
	struct ieee80211_local *local = sdata->local;
	bool started;

	mutex_lock(&local->mtx);

	if (roc->to_be_freed)
		goto out_unlock;

	if (roc->abort)
		goto finish;

	if (WARN_ON(list_empty(&local->roc_list)))
		goto out_unlock;

	if (WARN_ON(roc != list_first_entry(&local->roc_list,
					    struct ieee80211_roc_work,
					    list)))
		goto out_unlock;

	if (!roc->started) {
		struct ieee80211_roc_work *dep;

		/* start this ROC */

		/* switch channel etc */
		ieee80211_recalc_idle(local);

		local->tmp_channel = roc->chan;
		ieee80211_hw_config(local, 0);

		/* tell userspace or send frame */
		ieee80211_handle_roc_started(roc);
		list_for_each_entry(dep, &roc->dependents, list)
			ieee80211_handle_roc_started(dep);

		/* if it was pure TX, just finish right away */
		if (!roc->duration)
			goto finish;

		roc->started = true;
		ieee80211_queue_delayed_work(&local->hw, &roc->work,
					     msecs_to_jiffies(roc->duration));
	} else {
		/* finish this ROC */
 finish:
		list_del(&roc->list);
		started = roc->started;
		ieee80211_roc_notify_destroy(roc, !roc->abort);

		if (started) {
			drv_flush(local, false);

			local->tmp_channel = NULL;
			ieee80211_hw_config(local, 0);

			ieee80211_offchannel_return(local);
		}

		ieee80211_recalc_idle(local);

		if (started)
			ieee80211_start_next_roc(local);
	}

 out_unlock:
	mutex_unlock(&local->mtx);
}

static void ieee80211_hw_roc_done(struct work_struct *work)
{
	struct ieee80211_local *local =
		container_of(work, struct ieee80211_local, hw_roc_done);
	struct ieee80211_roc_work *roc;

	mutex_lock(&local->mtx);

	if (list_empty(&local->roc_list))
		goto out_unlock;

	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
			       list);

	if (!roc->started)
		goto out_unlock;

	list_del(&roc->list);

	ieee80211_roc_notify_destroy(roc, true);

	/* if there's another roc, start it now */
	ieee80211_start_next_roc(local);

 out_unlock:
	mutex_unlock(&local->mtx);
}

void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
{
	struct ieee80211_local *local = hw_to_local(hw);

	trace_api_remain_on_channel_expired(local);

	ieee80211_queue_work(hw, &local->hw_roc_done);
}
EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);

void ieee80211_roc_setup(struct ieee80211_local *local)
{
	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
	INIT_LIST_HEAD(&local->roc_list);
}

void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_roc_work *roc, *tmp;
	LIST_HEAD(tmp_list);

	mutex_lock(&local->mtx);
	list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
		if (roc->sdata != sdata)
			continue;

		if (roc->started && local->ops->remain_on_channel) {
			/* can race, so ignore return value */
			drv_cancel_remain_on_channel(local);
		}

		list_move_tail(&roc->list, &tmp_list);
		roc->abort = true;
	}
	mutex_unlock(&local->mtx);

	list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
		if (local->ops->remain_on_channel) {
			list_del(&roc->list);
			ieee80211_roc_notify_destroy(roc, true);
		} else {
			ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);

			/* work will clean up etc */
			flush_delayed_work(&roc->work);
			WARN_ON(!roc->to_be_freed);
			kfree(roc);
		}
	}

	WARN_ON_ONCE(!list_empty(&tmp_list));
}