offchannel.c 13.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14
/*
 * 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.
 */
15
#include <linux/export.h>
16 17
#include <net/mac80211.h>
#include "ieee80211_i.h"
18
#include "driver-ops.h"
19 20

/*
21 22 23 24 25
 * 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.
26
 */
27
static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
28 29
{
	struct ieee80211_local *local = sdata->local;
30
	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
31 32 33 34 35 36

	local->offchannel_ps_enabled = false;

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

	del_timer_sync(&local->dynamic_ps_timer);
37
	del_timer_sync(&ifmgd->bcn_mon_timer);
38 39
	del_timer_sync(&ifmgd->conn_mon_timer);

40 41 42 43 44 45 46 47
	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);
	}

48 49
	if (!local->offchannel_ps_enabled ||
	    !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
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
		/*
		 * 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.
		 */
84 85 86
		/* TODO:  Only set hardware if CONF_PS changed?
		 * TODO:  Should we set offchannel_ps_enabled to false?
		 */
87 88 89 90 91 92 93 94 95 96 97 98 99
		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));
	}
100

101
	ieee80211_sta_reset_beacon_monitor(sdata);
102
	ieee80211_sta_reset_conn_monitor(sdata);
103 104
}

105
void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
106 107 108
{
	struct ieee80211_sub_if_data *sdata;

109 110 111
	if (WARN_ON(local->use_chanctx))
		return;

112 113 114 115
	/*
	 * notify the AP about us leaving the channel and stop all
	 * STA interfaces.
	 */
116

117 118 119 120
	/*
	 * Stop queues and transmit all frames queued by the driver
	 * before sending nullfunc to enable powersave at the AP.
	 */
121
	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
122 123
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
					false);
124
	ieee80211_flush_queues(local, NULL, false);
125

126 127 128 129 130
	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(sdata))
			continue;

131 132 133
		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
			continue;

134 135 136 137
		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
			set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);

		/* Check to see if we should disable beaconing. */
138 139 140 141
		if (sdata->vif.bss_conf.enable_beacon) {
			set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
				&sdata->state);
			sdata->vif.bss_conf.enable_beacon = false;
142 143
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);
144
		}
145

146 147 148
		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    sdata->u.mgd.associated)
			ieee80211_offchannel_ps_enable(sdata);
149 150 151 152
	}
	mutex_unlock(&local->iflist_mtx);
}

153
void ieee80211_offchannel_return(struct ieee80211_local *local)
154 155 156
{
	struct ieee80211_sub_if_data *sdata;

157 158 159
	if (WARN_ON(local->use_chanctx))
		return;

160 161
	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
162 163 164
		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
			continue;

165 166 167
		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
			clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);

168 169 170 171
		if (!ieee80211_sdata_running(sdata))
			continue;

		/* Tell AP we're back */
172 173 174
		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    sdata->u.mgd.associated)
			ieee80211_offchannel_ps_disable(sdata);
175

176 177 178
		if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
				       &sdata->state)) {
			sdata->vif.bss_conf.enable_beacon = true;
179 180
			ieee80211_bss_info_change_notify(
				sdata, BSS_CHANGED_BEACON_ENABLED);
181
		}
182 183
	}
	mutex_unlock(&local->iflist_mtx);
184

185
	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
186 187
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
					false);
188
}
189

190 191 192 193 194 195 196
void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
{
	if (roc->notified)
		return;

	if (roc->mgmt_tx_cookie) {
		if (!WARN_ON(!roc->frame)) {
J
Johannes Berg 已提交
197 198
			ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
						  roc->chan->band);
199 200 201
			roc->frame = NULL;
		}
	} else {
202
		cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
203 204
					  roc->chan, roc->req_duration,
					  GFP_KERNEL);
205 206 207 208 209
	}

	roc->notified = true;
}

210 211 212 213
static void ieee80211_hw_roc_start(struct work_struct *work)
{
	struct ieee80211_local *local =
		container_of(work, struct ieee80211_local, hw_roc_start);
214
	struct ieee80211_roc_work *roc, *dep, *tmp;
215 216 217

	mutex_lock(&local->mtx);

218 219
	if (list_empty(&local->roc_list))
		goto out_unlock;
220

221 222 223 224 225 226 227 228
	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;
229

230 231 232 233 234 235 236 237
	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;
238
			list_move(&dep->list, &roc->list);
239 240 241
		}
	}
 out_unlock:
242 243 244 245 246 247 248
	mutex_unlock(&local->mtx);
}

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

249 250
	local->hw_roc_start_time = jiffies;

251 252 253 254 255 256
	trace_api_ready_on_channel(local);

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

257
void ieee80211_start_next_roc(struct ieee80211_local *local)
258
{
259
	struct ieee80211_roc_work *roc;
260

261
	lockdep_assert_held(&local->mtx);
262

263 264
	if (list_empty(&local->roc_list)) {
		ieee80211_run_deferred_scan(local);
265 266 267
		return;
	}

268 269
	roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
			       list);
270

271 272 273
	if (WARN_ON_ONCE(roc->started))
		return;

274 275
	if (local->ops->remain_on_channel) {
		int ret, duration = roc->duration;
276

277 278 279
		/* XXX: duplicated, see ieee80211_start_roc_work() */
		if (!duration)
			duration = 10;
280

281
		ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
282
					    duration, roc->type);
283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301

		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));
	}
}

302
void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
303 304 305
{
	struct ieee80211_roc_work *dep, *tmp;

306 307 308
	if (WARN_ON(roc->to_be_freed))
		return;

309 310
	/* was never transmitted */
	if (roc->frame) {
311
		cfg80211_mgmt_tx_status(&roc->sdata->wdev,
312 313 314 315
					(unsigned long)roc->frame,
					roc->frame->data, roc->frame->len,
					false, GFP_KERNEL);
		kfree_skb(roc->frame);
316 317
	}

318
	if (!roc->mgmt_tx_cookie)
319
		cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
320
						   roc->cookie, roc->chan,
321
						   GFP_KERNEL);
322

323
	list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
324
		ieee80211_roc_notify_destroy(dep, true);
325

326 327 328 329
	if (free)
		kfree(roc);
	else
		roc->to_be_freed = true;
330 331 332 333 334 335 336 337
}

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;
338
	bool started, on_channel;
339 340 341

	mutex_lock(&local->mtx);

342 343 344
	if (roc->to_be_freed)
		goto out_unlock;

345 346 347 348 349 350 351 352 353 354 355 356 357 358
	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;

359 360 361 362 363 364 365 366 367 368
		WARN_ON(local->use_chanctx);

		/* If actually operating on the desired channel (with at least
		 * 20 MHz channel width) don't stop all the operations but still
		 * treat it as though the ROC operation started properly, so
		 * other ROC operations won't interfere with this one.
		 */
		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
369

370
		/* start this ROC */
371 372
		ieee80211_recalc_idle(local);

373 374 375 376 377 378
		if (!roc->on_channel) {
			ieee80211_offchannel_stop_vifs(local);

			local->tmp_channel = roc->chan;
			ieee80211_hw_config(local, 0);
		}
379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395

		/* 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);
A
Alan Cox 已提交
396
		started = roc->started;
397
		on_channel = roc->on_channel;
398
		ieee80211_roc_notify_destroy(roc, !roc->abort);
399

400
		if (started && !on_channel) {
401
			ieee80211_flush_queues(local, NULL, false);
402 403 404 405

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

406
			ieee80211_offchannel_return(local);
407 408 409 410
		}

		ieee80211_recalc_idle(local);

A
Alan Cox 已提交
411
		if (started)
412
			ieee80211_start_next_roc(local);
413 414
		else if (list_empty(&local->roc_list))
			ieee80211_run_deferred_scan(local);
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
	}

 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);

440
	ieee80211_roc_notify_destroy(roc, true);
441 442 443 444 445

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

 out_unlock:
446 447 448 449 450 451 452 453 454 455 456 457 458
	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);

459
void ieee80211_roc_setup(struct ieee80211_local *local)
460 461 462
{
	INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
	INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
463 464 465
	INIT_LIST_HEAD(&local->roc_list);
}

466 467
void ieee80211_roc_purge(struct ieee80211_local *local,
			 struct ieee80211_sub_if_data *sdata)
468 469 470 471 472 473
{
	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) {
474
		if (sdata && roc->sdata != sdata)
475 476 477 478 479 480 481 482 483 484 485 486 487 488 489
			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);
490
			ieee80211_roc_notify_destroy(roc, true);
491 492 493 494 495
		} else {
			ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);

			/* work will clean up etc */
			flush_delayed_work(&roc->work);
496 497
			WARN_ON(!roc->to_be_freed);
			kfree(roc);
498 499 500 501
		}
	}

	WARN_ON_ONCE(!list_empty(&tmp_list));
502
}