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[mirror_ubuntu-zesty-kernel.git] / net / mac80211 / offchannel.c
1 /*
2 * Off-channel operation helpers
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15 #include <linux/export.h>
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "driver-ops.h"
19
20 /*
21 * Tell our hardware to disable PS.
22 * Optionally inform AP that we will go to sleep so that it will buffer
23 * the frames while we are doing off-channel work. This is optional
24 * because we *may* be doing work on-operating channel, and want our
25 * 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 local->offchannel_ps_enabled = false;
33
34 /* FIXME: what to do when local->pspolling is true? */
35
36 del_timer_sync(&local->dynamic_ps_timer);
37 del_timer_sync(&ifmgd->bcn_mon_timer);
38 del_timer_sync(&ifmgd->conn_mon_timer);
39
40 cancel_work_sync(&local->dynamic_ps_enable_work);
41
42 if (local->hw.conf.flags & IEEE80211_CONF_PS) {
43 local->offchannel_ps_enabled = true;
44 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
45 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
46 }
47
48 if (!local->offchannel_ps_enabled ||
49 !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
50 /*
51 * If power save was enabled, no need to send a nullfunc
52 * frame because AP knows that we are sleeping. But if the
53 * hardware is creating the nullfunc frame for power save
54 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
55 * enabled) and power save was enabled, the firmware just
56 * sent a null frame with power save disabled. So we need
57 * to send a new nullfunc frame to inform the AP that we
58 * are again sleeping.
59 */
60 ieee80211_send_nullfunc(local, sdata, true);
61 }
62
63 /* inform AP that we are awake again, unless power save is enabled */
64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
65 {
66 struct ieee80211_local *local = sdata->local;
67
68 if (!local->ps_sdata)
69 ieee80211_send_nullfunc(local, sdata, false);
70 else if (local->offchannel_ps_enabled) {
71 /*
72 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
73 * will send a nullfunc frame with the powersave bit set
74 * even though the AP already knows that we are sleeping.
75 * This could be avoided by sending a null frame with power
76 * save bit disabled before enabling the power save, but
77 * this doesn't gain anything.
78 *
79 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
80 * to send a nullfunc frame because AP already knows that
81 * we are sleeping, let's just enable power save mode in
82 * hardware.
83 */
84 /* TODO: Only set hardware if CONF_PS changed?
85 * TODO: Should we set offchannel_ps_enabled to false?
86 */
87 local->hw.conf.flags |= IEEE80211_CONF_PS;
88 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
89 } else if (local->hw.conf.dynamic_ps_timeout > 0) {
90 /*
91 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
92 * had been running before leaving the operating channel,
93 * restart the timer now and send a nullfunc frame to inform
94 * the AP that we are awake.
95 */
96 ieee80211_send_nullfunc(local, sdata, false);
97 mod_timer(&local->dynamic_ps_timer, jiffies +
98 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
99 }
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 struct ieee80211_sub_if_data *sdata;
108
109 if (WARN_ON(local->use_chanctx))
110 return;
111
112 /*
113 * notify the AP about us leaving the channel and stop all
114 * STA interfaces.
115 */
116
117 /*
118 * Stop queues and transmit all frames queued by the driver
119 * before sending nullfunc to enable powersave at the AP.
120 */
121 ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
122 IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
123 false);
124 ieee80211_flush_queues(local, NULL, false);
125
126 mutex_lock(&local->iflist_mtx);
127 list_for_each_entry(sdata, &local->interfaces, list) {
128 if (!ieee80211_sdata_running(sdata))
129 continue;
130
131 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
132 continue;
133
134 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
135 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
136
137 /* Check to see if we should disable beaconing. */
138 if (sdata->vif.bss_conf.enable_beacon) {
139 set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
140 &sdata->state);
141 sdata->vif.bss_conf.enable_beacon = false;
142 ieee80211_bss_info_change_notify(
143 sdata, BSS_CHANGED_BEACON_ENABLED);
144 }
145
146 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
147 sdata->u.mgd.associated)
148 ieee80211_offchannel_ps_enable(sdata);
149 }
150 mutex_unlock(&local->iflist_mtx);
151 }
152
153 void ieee80211_offchannel_return(struct ieee80211_local *local)
154 {
155 struct ieee80211_sub_if_data *sdata;
156
157 if (WARN_ON(local->use_chanctx))
158 return;
159
160 mutex_lock(&local->iflist_mtx);
161 list_for_each_entry(sdata, &local->interfaces, list) {
162 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
163 continue;
164
165 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
166 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
167
168 if (!ieee80211_sdata_running(sdata))
169 continue;
170
171 /* Tell AP we're back */
172 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
173 sdata->u.mgd.associated)
174 ieee80211_offchannel_ps_disable(sdata);
175
176 if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
177 &sdata->state)) {
178 sdata->vif.bss_conf.enable_beacon = true;
179 ieee80211_bss_info_change_notify(
180 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 IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
187 false);
188 }
189
190 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
191 {
192 if (roc->notified)
193 return;
194
195 if (roc->mgmt_tx_cookie) {
196 if (!WARN_ON(!roc->frame)) {
197 ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
198 roc->chan->band);
199 roc->frame = NULL;
200 }
201 } else {
202 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
203 roc->chan, roc->req_duration,
204 GFP_KERNEL);
205 }
206
207 roc->notified = true;
208 }
209
210 static void ieee80211_hw_roc_start(struct work_struct *work)
211 {
212 struct ieee80211_local *local =
213 container_of(work, struct ieee80211_local, hw_roc_start);
214 struct ieee80211_roc_work *roc, *dep, *tmp;
215
216 mutex_lock(&local->mtx);
217
218 if (list_empty(&local->roc_list))
219 goto out_unlock;
220
221 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
222 list);
223
224 if (!roc->started)
225 goto out_unlock;
226
227 roc->hw_begun = true;
228 roc->hw_start_time = local->hw_roc_start_time;
229
230 ieee80211_handle_roc_started(roc);
231 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
232 ieee80211_handle_roc_started(dep);
233
234 if (dep->duration > roc->duration) {
235 u32 dur = dep->duration;
236 dep->duration = dur - roc->duration;
237 roc->duration = dur;
238 list_move(&dep->list, &roc->list);
239 }
240 }
241 out_unlock:
242 mutex_unlock(&local->mtx);
243 }
244
245 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
246 {
247 struct ieee80211_local *local = hw_to_local(hw);
248
249 local->hw_roc_start_time = jiffies;
250
251 trace_api_ready_on_channel(local);
252
253 ieee80211_queue_work(hw, &local->hw_roc_start);
254 }
255 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
256
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 if (list_empty(&local->roc_list)) {
264 ieee80211_run_deferred_scan(local);
265 return;
266 }
267
268 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
269 list);
270
271 if (WARN_ON_ONCE(roc->started))
272 return;
273
274 if (local->ops->remain_on_channel) {
275 int ret, duration = roc->duration;
276
277 /* XXX: duplicated, see ieee80211_start_roc_work() */
278 if (!duration)
279 duration = 10;
280
281 ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
282 duration, roc->type);
283
284 roc->started = true;
285
286 if (ret) {
287 wiphy_warn(local->hw.wiphy,
288 "failed to start next HW ROC (%d)\n", ret);
289 /*
290 * queue the work struct again to avoid recursion
291 * when multiple failures occur
292 */
293 ieee80211_remain_on_channel_expired(&local->hw);
294 }
295 } else {
296 /* delay it a bit */
297 ieee80211_queue_delayed_work(&local->hw, &roc->work,
298 round_jiffies_relative(HZ/2));
299 }
300 }
301
302 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc, bool free)
303 {
304 struct ieee80211_roc_work *dep, *tmp;
305
306 if (WARN_ON(roc->to_be_freed))
307 return;
308
309 /* was never transmitted */
310 if (roc->frame) {
311 cfg80211_mgmt_tx_status(&roc->sdata->wdev,
312 (unsigned long)roc->frame,
313 roc->frame->data, roc->frame->len,
314 false, GFP_KERNEL);
315 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 if (free)
327 kfree(roc);
328 else
329 roc->to_be_freed = true;
330 }
331
332 void ieee80211_sw_roc_work(struct work_struct *work)
333 {
334 struct ieee80211_roc_work *roc =
335 container_of(work, struct ieee80211_roc_work, work.work);
336 struct ieee80211_sub_if_data *sdata = roc->sdata;
337 struct ieee80211_local *local = sdata->local;
338 bool started, on_channel;
339
340 mutex_lock(&local->mtx);
341
342 if (roc->to_be_freed)
343 goto out_unlock;
344
345 if (roc->abort)
346 goto finish;
347
348 if (WARN_ON(list_empty(&local->roc_list)))
349 goto out_unlock;
350
351 if (WARN_ON(roc != list_first_entry(&local->roc_list,
352 struct ieee80211_roc_work,
353 list)))
354 goto out_unlock;
355
356 if (!roc->started) {
357 struct ieee80211_roc_work *dep;
358
359 WARN_ON(local->use_chanctx);
360
361 /* If actually operating on the desired channel (with at least
362 * 20 MHz channel width) don't stop all the operations but still
363 * treat it as though the ROC operation started properly, so
364 * other ROC operations won't interfere with this one.
365 */
366 roc->on_channel = roc->chan == local->_oper_chandef.chan &&
367 local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
368 local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
369
370 /* start this ROC */
371 ieee80211_recalc_idle(local);
372
373 if (!roc->on_channel) {
374 ieee80211_offchannel_stop_vifs(local);
375
376 local->tmp_channel = roc->chan;
377 ieee80211_hw_config(local, 0);
378 }
379
380 /* tell userspace or send frame */
381 ieee80211_handle_roc_started(roc);
382 list_for_each_entry(dep, &roc->dependents, list)
383 ieee80211_handle_roc_started(dep);
384
385 /* if it was pure TX, just finish right away */
386 if (!roc->duration)
387 goto finish;
388
389 roc->started = true;
390 ieee80211_queue_delayed_work(&local->hw, &roc->work,
391 msecs_to_jiffies(roc->duration));
392 } else {
393 /* finish this ROC */
394 finish:
395 list_del(&roc->list);
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 local->tmp_channel = NULL;
404 ieee80211_hw_config(local, 0);
405
406 ieee80211_offchannel_return(local);
407 }
408
409 ieee80211_recalc_idle(local);
410
411 if (started)
412 ieee80211_start_next_roc(local);
413 else if (list_empty(&local->roc_list))
414 ieee80211_run_deferred_scan(local);
415 }
416
417 out_unlock:
418 mutex_unlock(&local->mtx);
419 }
420
421 static void ieee80211_hw_roc_done(struct work_struct *work)
422 {
423 struct ieee80211_local *local =
424 container_of(work, struct ieee80211_local, hw_roc_done);
425 struct ieee80211_roc_work *roc;
426
427 mutex_lock(&local->mtx);
428
429 if (list_empty(&local->roc_list))
430 goto out_unlock;
431
432 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
433 list);
434
435 if (!roc->started)
436 goto out_unlock;
437
438 list_del(&roc->list);
439
440 ieee80211_roc_notify_destroy(roc, true);
441
442 /* if there's another roc, start it now */
443 ieee80211_start_next_roc(local);
444
445 out_unlock:
446 mutex_unlock(&local->mtx);
447 }
448
449 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
450 {
451 struct ieee80211_local *local = hw_to_local(hw);
452
453 trace_api_remain_on_channel_expired(local);
454
455 ieee80211_queue_work(hw, &local->hw_roc_done);
456 }
457 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
458
459 void ieee80211_roc_setup(struct ieee80211_local *local)
460 {
461 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
462 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
463 INIT_LIST_HEAD(&local->roc_list);
464 }
465
466 void ieee80211_roc_purge(struct ieee80211_local *local,
467 struct ieee80211_sub_if_data *sdata)
468 {
469 struct ieee80211_roc_work *roc, *tmp;
470 LIST_HEAD(tmp_list);
471
472 mutex_lock(&local->mtx);
473 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
474 if (sdata && roc->sdata != sdata)
475 continue;
476
477 if (roc->started && local->ops->remain_on_channel) {
478 /* can race, so ignore return value */
479 drv_cancel_remain_on_channel(local);
480 }
481
482 list_move_tail(&roc->list, &tmp_list);
483 roc->abort = true;
484 }
485 mutex_unlock(&local->mtx);
486
487 list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
488 if (local->ops->remain_on_channel) {
489 list_del(&roc->list);
490 ieee80211_roc_notify_destroy(roc, true);
491 } else {
492 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
493
494 /* work will clean up etc */
495 flush_delayed_work(&roc->work);
496 WARN_ON(!roc->to_be_freed);
497 kfree(roc);
498 }
499 }
500
501 WARN_ON_ONCE(!list_empty(&tmp_list));
502 }