aboutsummaryrefslogtreecommitdiff
path: root/net/mac80211/chan.c
blob: 03e8d2e3270e23f0e97a58595513b33fcb048cb3 (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
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
/*
 * mac80211 - channel management
 */

#include <linux/nl80211.h>
#include <linux/export.h>
#include <linux/rtnetlink.h>
#include <net/cfg80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"

static void ieee80211_change_chanctx(struct ieee80211_local *local,
				     struct ieee80211_chanctx *ctx,
				     const struct cfg80211_chan_def *chandef)
{
	if (cfg80211_chandef_identical(&ctx->conf.def, chandef))
		return;

	WARN_ON(!cfg80211_chandef_compatible(&ctx->conf.def, chandef));

	ctx->conf.def = *chandef;
	drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_WIDTH);

	if (!local->use_chanctx) {
		local->_oper_chandef = *chandef;
		ieee80211_hw_config(local, 0);
	}
}

static struct ieee80211_chanctx *
ieee80211_find_chanctx(struct ieee80211_local *local,
		       const struct cfg80211_chan_def *chandef,
		       enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;

	lockdep_assert_held(&local->chanctx_mtx);

	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
		return NULL;

	list_for_each_entry(ctx, &local->chanctx_list, list) {
		const struct cfg80211_chan_def *compat;

		if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
			continue;

		compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef);
		if (!compat)
			continue;

		ieee80211_change_chanctx(local, ctx, compat);

		return ctx;
	}

	return NULL;
}

static bool ieee80211_is_radar_required(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		if (sdata->radar_required) {
			rcu_read_unlock();
			return true;
		}
	}
	rcu_read_unlock();

	return false;
}

static struct ieee80211_chanctx *
ieee80211_new_chanctx(struct ieee80211_local *local,
		      const struct cfg80211_chan_def *chandef,
		      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_chanctx *ctx;
	u32 changed;
	int err;

	lockdep_assert_held(&local->chanctx_mtx);

	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
	if (!ctx)
		return ERR_PTR(-ENOMEM);

	ctx->conf.def = *chandef;
	ctx->conf.rx_chains_static = 1;
	ctx->conf.rx_chains_dynamic = 1;
	ctx->mode = mode;
	ctx->conf.radar_enabled = ieee80211_is_radar_required(local);
	if (!local->use_chanctx)
		local->hw.conf.radar_enabled = ctx->conf.radar_enabled;

	/* acquire mutex to prevent idle from changing */
	mutex_lock(&local->mtx);
	/* turn idle off *before* setting channel -- some drivers need that */
	changed = ieee80211_idle_off(local);
	if (changed)
		ieee80211_hw_config(local, changed);

	if (!local->use_chanctx) {
		local->_oper_chandef = *chandef;
		ieee80211_hw_config(local, 0);
	} else {
		err = drv_add_chanctx(local, ctx);
		if (err) {
			kfree(ctx);
			ctx = ERR_PTR(err);

			ieee80211_recalc_idle(local);
			goto out;
		}
	}

	/* and keep the mutex held until the new chanctx is on the list */
	list_add_rcu(&ctx->list, &local->chanctx_list);

 out:
	mutex_unlock(&local->mtx);

	return ctx;
}

static void ieee80211_free_chanctx(struct ieee80211_local *local,
				   struct ieee80211_chanctx *ctx)
{
	bool check_single_channel = false;
	lockdep_assert_held(&local->chanctx_mtx);

	WARN_ON_ONCE(ctx->refcount != 0);

	if (!local->use_chanctx) {
		struct cfg80211_chan_def *chandef = &local->_oper_chandef;
		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
		chandef->center_freq1 = chandef->chan->center_freq;
		chandef->center_freq2 = 0;

		/* NOTE: Disabling radar is only valid here for
		 * single channel context. To be sure, check it ...
		 */
		if (local->hw.conf.radar_enabled)
			check_single_channel = true;
		local->hw.conf.radar_enabled = false;

		ieee80211_hw_config(local, 0);
	} else {
		drv_remove_chanctx(local, ctx);
	}

	list_del_rcu(&ctx->list);
	kfree_rcu(ctx, rcu_head);

	/* throw a warning if this wasn't the only channel context. */
	WARN_ON(check_single_channel && !list_empty(&local->chanctx_list));

	mutex_lock(&local->mtx);
	ieee80211_recalc_idle(local);
	mutex_unlock(&local->mtx);
}

static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_chanctx *ctx)
{
	struct ieee80211_local *local = sdata->local;
	int ret;

	lockdep_assert_held(&local->chanctx_mtx);

	ret = drv_assign_vif_chanctx(local, sdata, ctx);
	if (ret)
		return ret;

	rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
	ctx->refcount++;

	ieee80211_recalc_txpower(sdata);
	sdata->vif.bss_conf.idle = false;

	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);

	return 0;
}

static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
					      struct ieee80211_chanctx *ctx)
{
	struct ieee80211_chanctx_conf *conf = &ctx->conf;
	struct ieee80211_sub_if_data *sdata;
	const struct cfg80211_chan_def *compat = NULL;

	lockdep_assert_held(&local->chanctx_mtx);

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {

		if (!ieee80211_sdata_running(sdata))
			continue;
		if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
			continue;

		if (!compat)
			compat = &sdata->vif.bss_conf.chandef;

		compat = cfg80211_chandef_compatible(
				&sdata->vif.bss_conf.chandef, compat);
		if (!compat)
			break;
	}
	rcu_read_unlock();

	if (WARN_ON_ONCE(!compat))
		return;

	ieee80211_change_chanctx(local, ctx, compat);
}

static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
					   struct ieee80211_chanctx *ctx)
{
	struct ieee80211_local *local = sdata->local;

	lockdep_assert_held(&local->chanctx_mtx);

	ctx->refcount--;
	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);

	sdata->vif.bss_conf.idle = true;

	if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
	    sdata->vif.type != NL80211_IFTYPE_MONITOR)
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);

	drv_unassign_vif_chanctx(local, sdata, ctx);

	if (ctx->refcount > 0) {
		ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
		ieee80211_recalc_smps_chanctx(local, ctx);
		ieee80211_recalc_radar_chanctx(local, ctx);
	}
}

static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx_conf *conf;
	struct ieee80211_chanctx *ctx;

	lockdep_assert_held(&local->chanctx_mtx);

	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
					 lockdep_is_held(&local->chanctx_mtx));
	if (!conf)
		return;

	ctx = container_of(conf, struct ieee80211_chanctx, conf);

	ieee80211_unassign_vif_chanctx(sdata, ctx);
	if (ctx->refcount == 0)
		ieee80211_free_chanctx(local, ctx);
}

void ieee80211_recalc_radar_chanctx(struct ieee80211_local *local,
				    struct ieee80211_chanctx *chanctx)
{
	bool radar_enabled;

	lockdep_assert_held(&local->chanctx_mtx);

	radar_enabled = ieee80211_is_radar_required(local);

	if (radar_enabled == chanctx->conf.radar_enabled)
		return;

	chanctx->conf.radar_enabled = radar_enabled;
	local->radar_detect_enabled = chanctx->conf.radar_enabled;

	if (!local->use_chanctx) {
		local->hw.conf.radar_enabled = chanctx->conf.radar_enabled;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
	}

	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RADAR);
}

void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
				   struct ieee80211_chanctx *chanctx)
{
	struct ieee80211_sub_if_data *sdata;
	u8 rx_chains_static, rx_chains_dynamic;

	lockdep_assert_held(&local->chanctx_mtx);

	rx_chains_static = 1;
	rx_chains_dynamic = 1;

	rcu_read_lock();
	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
		u8 needed_static, needed_dynamic;

		if (!ieee80211_sdata_running(sdata))
			continue;

		if (rcu_access_pointer(sdata->vif.chanctx_conf) !=
						&chanctx->conf)
			continue;

		switch (sdata->vif.type) {
		case NL80211_IFTYPE_P2P_DEVICE:
			continue;
		case NL80211_IFTYPE_STATION:
			if (!sdata->u.mgd.associated)
				continue;
			break;
		case NL80211_IFTYPE_AP_VLAN:
			continue;
		case NL80211_IFTYPE_AP:
		case NL80211_IFTYPE_ADHOC:
		case NL80211_IFTYPE_WDS:
		case NL80211_IFTYPE_MESH_POINT:
			break;
		default:
			WARN_ON_ONCE(1);
		}

		switch (sdata->smps_mode) {
		default:
			WARN_ONCE(1, "Invalid SMPS mode %d\n",
				  sdata->smps_mode);
			/* fall through */
		case IEEE80211_SMPS_OFF:
			needed_static = sdata->needed_rx_chains;
			needed_dynamic = sdata->needed_rx_chains;
			break;
		case IEEE80211_SMPS_DYNAMIC:
			needed_static = 1;
			needed_dynamic = sdata->needed_rx_chains;
			break;
		case IEEE80211_SMPS_STATIC:
			needed_static = 1;
			needed_dynamic = 1;
			break;
		}

		rx_chains_static = max(rx_chains_static, needed_static);
		rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
	}
	rcu_read_unlock();

	if (!local->use_chanctx) {
		if (rx_chains_static > 1)
			local->smps_mode = IEEE80211_SMPS_OFF;
		else if (rx_chains_dynamic > 1)
			local->smps_mode = IEEE80211_SMPS_DYNAMIC;
		else
			local->smps_mode = IEEE80211_SMPS_STATIC;
		ieee80211_hw_config(local, 0);
	}

	if (rx_chains_static == chanctx->conf.rx_chains_static &&
	    rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
		return;

	chanctx->conf.rx_chains_static = rx_chains_static;
	chanctx->conf.rx_chains_dynamic = rx_chains_dynamic;
	drv_change_chanctx(local, chanctx, IEEE80211_CHANCTX_CHANGE_RX_CHAINS);
}

int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
			      const struct cfg80211_chan_def *chandef,
			      enum ieee80211_chanctx_mode mode)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx *ctx;
	int ret;

	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));

	mutex_lock(&local->chanctx_mtx);
	__ieee80211_vif_release_channel(sdata);

	ctx = ieee80211_find_chanctx(local, chandef, mode);
	if (!ctx)
		ctx = ieee80211_new_chanctx(local, chandef, mode);
	if (IS_ERR(ctx)) {
		ret = PTR_ERR(ctx);
		goto out;
	}

	sdata->vif.bss_conf.chandef = *chandef;

	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
	if (ret) {
		/* if assign fails refcount stays the same */
		if (ctx->refcount == 0)
			ieee80211_free_chanctx(local, ctx);
		goto out;
	}

	ieee80211_recalc_smps_chanctx(local, ctx);
	ieee80211_recalc_radar_chanctx(local, ctx);
 out:
	mutex_unlock(&local->chanctx_mtx);
	return ret;
}

int ieee80211_vif_change_bandwidth(struct ieee80211_sub_if_data *sdata,
				   const struct cfg80211_chan_def *chandef,
				   u32 *changed)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_chanctx_conf *conf;
	struct ieee80211_chanctx *ctx;
	int ret;

	if (!cfg80211_chandef_usable(sdata->local->hw.wiphy, chandef,
				     IEEE80211_CHAN_DISABLED))
		return -EINVAL;

	mutex_lock(&local->chanctx_mtx);
	if (cfg80211_chandef_identical(chandef, &sdata->vif.bss_conf.chandef)) {
		ret = 0;
		goto out;
	}

	if (chandef->width == NL80211_CHAN_WIDTH_20_NOHT ||
	    sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT) {
		ret = -EINVAL;
		goto out;
	}

	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
					 lockdep_is_held(&local->chanctx_mtx));
	if (!conf) {
		ret = -EINVAL;
		goto out;
	}

	ctx = container_of(conf, struct ieee80211_chanctx, conf);
	if (!cfg80211_chandef_compatible(&conf->def, chandef)) {
		ret = -EINVAL;
		goto out;
	}

	sdata->vif.bss_conf.chandef = *chandef;

	ieee80211_recalc_chanctx_chantype(local, ctx);

	*changed |= BSS_CHANGED_BANDWIDTH;
	ret = 0;
 out:
	mutex_unlock(&local->chanctx_mtx);
	return ret;
}

void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
{
	WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));

	mutex_lock(&sdata->local->chanctx_mtx);
	__ieee80211_vif_release_channel(sdata);
	mutex_unlock(&sdata->local->chanctx_mtx);
}

void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sub_if_data *ap;
	struct ieee80211_chanctx_conf *conf;

	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->bss))
		return;

	ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);

	mutex_lock(&local->chanctx_mtx);

	conf = rcu_dereference_protected(ap->vif.chanctx_conf,
					 lockdep_is_held(&local->chanctx_mtx));
	rcu_assign_pointer(sdata->vif.chanctx_conf, conf);
	mutex_unlock(&local->chanctx_mtx);
}

void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata,
					 bool clear)
{
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_sub_if_data *vlan;
	struct ieee80211_chanctx_conf *conf;

	ASSERT_RTNL();

	if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP))
		return;

	mutex_lock(&local->chanctx_mtx);

	/*
	 * Check that conf exists, even when clearing this function
	 * must be called with the AP's channel context still there
	 * as it would otherwise cause VLANs to have an invalid
	 * channel context pointer for a while, possibly pointing
	 * to a channel context that has already been freed.
	 */
	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
				lockdep_is_held(&local->chanctx_mtx));
	WARN_ON(!conf);

	if (clear)
		conf = NULL;

	list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
		rcu_assign_pointer(vlan->vif.chanctx_conf, conf);

	mutex_unlock(&local->chanctx_mtx);
}

void ieee80211_iter_chan_contexts_atomic(
	struct ieee80211_hw *hw,
	void (*iter)(struct ieee80211_hw *hw,
		     struct ieee80211_chanctx_conf *chanctx_conf,
		     void *data),
	void *iter_data)
{
	struct ieee80211_local *local = hw_to_local(hw);
	struct ieee80211_chanctx *ctx;

	rcu_read_lock();
	list_for_each_entry_rcu(ctx, &local->chanctx_list, list)
		if (ctx->driver_present)
			iter(hw, &ctx->conf, iter_data);
	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic);