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 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
 191 {
 192         /* was never transmitted */
 193         if (roc->frame) {
 194                 cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
 195                                         roc->frame->data, roc->frame->len,
 196                                         false, GFP_KERNEL);
 197                 ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
 198         }
 199
 200         if (!roc->mgmt_tx_cookie)
 201                 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
 202                                                    roc->cookie, roc->chan,
 203                                                    GFP_KERNEL);
 204
 205         list_del(&roc->list);
 206         kfree(roc);
 207 }
 208
 209 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
 210                                                  unsigned long now)
 211 {
 212         struct ieee80211_roc_work *roc, *tmp;
 213         long remaining_dur_min = LONG_MAX;
 214
 215         lockdep_assert_held(&local->mtx);
 216
 217         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 218                 long remaining;
 219
 220                 if (!roc->started)
 221                         break;
 222
 223                 remaining = roc->start_time +
 224                             msecs_to_jiffies(roc->duration) -
 225                             now;
 226
 227                 /* In case of HW ROC, it is possible that the HW finished the
 228                  * ROC session before the actual requested time. In such a case
 229                  * end the ROC session (disregarding the remaining time).
 230                  */
 231                 if (roc->abort || roc->hw_begun || remaining <= 0)
 232                         ieee80211_roc_notify_destroy(roc);
 233                 else
 234                         remaining_dur_min = min(remaining_dur_min, remaining);
 235         }
 236
 237         return remaining_dur_min;
 238 }
 239
 240 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
 241                                      unsigned long now)
 242 {
 243         long dur = ieee80211_end_finished_rocs(local, now);
 244
 245         if (dur == LONG_MAX)
 246                 return false;
 247
 248         mod_delayed_work(local->workqueue, &local->roc_work, dur);
 249         return true;
 250 }
 251
 252 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
 253                                          unsigned long start_time)
 254 {
 255         if (WARN_ON(roc->notified))
 256                 return;
 257
 258         roc->start_time = start_time;
 259         roc->started = true;
 260
 261         if (roc->mgmt_tx_cookie) {
 262                 if (!WARN_ON(!roc->frame)) {
 263                         ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
 264                                                   roc->chan->band);
 265                         roc->frame = NULL;
 266                 }
 267         } else {
 268                 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
 269                                           roc->chan, roc->req_duration,
 270                                           GFP_KERNEL);
 271         }
 272
 273         roc->notified = true;
 274 }
 275
 276 static void ieee80211_hw_roc_start(struct work_struct *work)
 277 {
 278         struct ieee80211_local *local =
 279                 container_of(work, struct ieee80211_local, hw_roc_start);
 280         struct ieee80211_roc_work *roc;
 281
 282         mutex_lock(&local->mtx);
 283
 284         list_for_each_entry(roc, &local->roc_list, list) {
 285                 if (!roc->started)
 286                         break;
 287
 288                 roc->hw_begun = true;
 289                 ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
 290         }
 291
 292         mutex_unlock(&local->mtx);
 293 }
 294
 295 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
 296 {
 297         struct ieee80211_local *local = hw_to_local(hw);
 298
 299         local->hw_roc_start_time = jiffies;
 300
 301         trace_api_ready_on_channel(local);
 302
 303         ieee80211_queue_work(hw, &local->hw_roc_start);
 304 }
 305 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
 306
 307 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
 308 {
 309         struct ieee80211_roc_work *roc, *tmp;
 310         enum ieee80211_roc_type type;
 311         u32 min_dur, max_dur;
 312
 313         lockdep_assert_held(&local->mtx);
 314
 315         if (WARN_ON(list_empty(&local->roc_list)))
 316                 return;
 317
 318         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 319                                list);
 320
 321         if (WARN_ON(roc->started))
 322                 return;
 323
 324         min_dur = roc->duration;
 325         max_dur = roc->duration;
 326         type = roc->type;
 327
 328         list_for_each_entry(tmp, &local->roc_list, list) {
 329                 if (tmp == roc)
 330                         continue;
 331                 if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 332                         break;
 333                 max_dur = max(tmp->duration, max_dur);
 334                 min_dur = min(tmp->duration, min_dur);
 335                 type = max(tmp->type, type);
 336         }
 337
 338         if (local->ops->remain_on_channel) {
 339                 int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
 340                                                 max_dur, type);
 341
 342                 if (ret) {
 343                         wiphy_warn(local->hw.wiphy,
 344                                    "failed to start next HW ROC (%d)\n", ret);
 345                         /*
 346                          * queue the work struct again to avoid recursion
 347                          * when multiple failures occur
 348                          */
 349                         list_for_each_entry(tmp, &local->roc_list, list) {
 350                                 if (tmp->sdata != roc->sdata ||
 351                                     tmp->chan != roc->chan)
 352                                         break;
 353                                 tmp->started = true;
 354                                 tmp->abort = true;
 355                         }
 356                         ieee80211_queue_work(&local->hw, &local->hw_roc_done);
 357                         return;
 358                 }
 359
 360                 /* we'll notify about the start once the HW calls back */
 361                 list_for_each_entry(tmp, &local->roc_list, list) {
 362                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 363                                 break;
 364                         tmp->started = true;
 365                 }
 366         } else {
 367                 /* If actually operating on the desired channel (with at least
 368                  * 20 MHz channel width) don't stop all the operations but still
 369                  * treat it as though the ROC operation started properly, so
 370                  * other ROC operations won't interfere with this one.
 371                  */
 372                 roc->on_channel = roc->chan == local->_oper_chandef.chan &&
 373                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
 374                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
 375
 376                 /* start this ROC */
 377                 ieee80211_recalc_idle(local);
 378
 379                 if (!roc->on_channel) {
 380                         ieee80211_offchannel_stop_vifs(local);
 381
 382                         local->tmp_channel = roc->chan;
 383                         ieee80211_hw_config(local, 0);
 384                 }
 385
 386                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 387                                              msecs_to_jiffies(min_dur));
 388
 389                 /* tell userspace or send frame(s) */
 390                 list_for_each_entry(tmp, &local->roc_list, list) {
 391                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 392                                 break;
 393
 394                         tmp->on_channel = roc->on_channel;
 395                         ieee80211_handle_roc_started(tmp, jiffies);
 396                 }
 397         }
 398 }
 399
 400 void ieee80211_start_next_roc(struct ieee80211_local *local)
 401 {
 402         struct ieee80211_roc_work *roc;
 403
 404         lockdep_assert_held(&local->mtx);
 405
 406         if (list_empty(&local->roc_list)) {
 407                 ieee80211_run_deferred_scan(local);
 408                 return;
 409         }
 410
 411         /* defer roc if driver is not started (i.e. during reconfig) */
 412         if (local->in_reconfig)
 413                 return;
 414
 415         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 416                                list);
 417
 418         if (WARN_ON_ONCE(roc->started))
 419                 return;
 420
 421         if (local->ops->remain_on_channel) {
 422                 _ieee80211_start_next_roc(local);
 423         } else {
 424                 /* delay it a bit */
 425                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 426                                              round_jiffies_relative(HZ/2));
 427         }
 428 }
 429
 430 static void __ieee80211_roc_work(struct ieee80211_local *local)
 431 {
 432         struct ieee80211_roc_work *roc;
 433         bool on_channel;
 434
 435         lockdep_assert_held(&local->mtx);
 436
 437         if (WARN_ON(local->ops->remain_on_channel))
 438                 return;
 439
 440         roc = list_first_entry_or_null(&local->roc_list,
 441                                        struct ieee80211_roc_work, list);
 442         if (!roc)
 443                 return;
 444
 445         if (!roc->started) {
 446                 WARN_ON(local->use_chanctx);
 447                 _ieee80211_start_next_roc(local);
 448         } else {
 449                 on_channel = roc->on_channel;
 450                 if (ieee80211_recalc_sw_work(local, jiffies))
 451                         return;
 452
 453                 /* careful - roc pointer became invalid during recalc */
 454
 455                 if (!on_channel) {
 456                         ieee80211_flush_queues(local, NULL, false);
 457
 458                         local->tmp_channel = NULL;
 459                         ieee80211_hw_config(local, 0);
 460
 461                         ieee80211_offchannel_return(local);
 462                 }
 463
 464                 ieee80211_recalc_idle(local);
 465                 ieee80211_start_next_roc(local);
 466         }
 467 }
 468
 469 static void ieee80211_roc_work(struct work_struct *work)
 470 {
 471         struct ieee80211_local *local =
 472                 container_of(work, struct ieee80211_local, roc_work.work);
 473
 474         mutex_lock(&local->mtx);
 475         __ieee80211_roc_work(local);
 476         mutex_unlock(&local->mtx);
 477 }
 478
 479 static void ieee80211_hw_roc_done(struct work_struct *work)
 480 {
 481         struct ieee80211_local *local =
 482                 container_of(work, struct ieee80211_local, hw_roc_done);
 483
 484         mutex_lock(&local->mtx);
 485
 486         ieee80211_end_finished_rocs(local, jiffies);
 487
 488         /* if there's another roc, start it now */
 489         ieee80211_start_next_roc(local);
 490
 491         mutex_unlock(&local->mtx);
 492 }
 493
 494 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
 495 {
 496         struct ieee80211_local *local = hw_to_local(hw);
 497
 498         trace_api_remain_on_channel_expired(local);
 499
 500         ieee80211_queue_work(hw, &local->hw_roc_done);
 501 }
 502 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
 503
 504 static bool
 505 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
 506                                   struct ieee80211_roc_work *new_roc,
 507                                   struct ieee80211_roc_work *cur_roc)
 508 {
 509         unsigned long now = jiffies;
 510         unsigned long remaining;
 511
 512         if (WARN_ON(!cur_roc->started))
 513                 return false;
 514
 515         /* if it was scheduled in the hardware, but not started yet,
 516          * we can only combine if the older one had a longer duration
 517          */
 518         if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
 519                 return false;
 520
 521         remaining = cur_roc->start_time +
 522                     msecs_to_jiffies(cur_roc->duration) -
 523                     now;
 524
 525         /* if it doesn't fit entirely, schedule a new one */
 526         if (new_roc->duration > jiffies_to_msecs(remaining))
 527                 return false;
 528
 529         /* add just after the current one so we combine their finish later */
 530         list_add(&new_roc->list, &cur_roc->list);
 531
 532         /* if the existing one has already begun then let this one also
 533          * begin, otherwise they'll both be marked properly by the work
 534          * struct that runs once the driver notifies us of the beginning
 535          */
 536         if (cur_roc->hw_begun) {
 537                 new_roc->hw_begun = true;
 538                 ieee80211_handle_roc_started(new_roc, now);
 539         }
 540
 541         return true;
 542 }
 543
 544 static int ieee80211_start_roc_work(struct ieee80211_local *local,
 545                                     struct ieee80211_sub_if_data *sdata,
 546                                     struct ieee80211_channel *channel,
 547                                     unsigned int duration, u64 *cookie,
 548                                     struct sk_buff *txskb,
 549                                     enum ieee80211_roc_type type)
 550 {
 551         struct ieee80211_roc_work *roc, *tmp;
 552         bool queued = false, combine_started = true;
 553         int ret;
 554
 555         lockdep_assert_held(&local->mtx);
 556
 557         if (local->use_chanctx && !local->ops->remain_on_channel)
 558                 return -EOPNOTSUPP;
 559
 560         roc = kzalloc(sizeof(*roc), GFP_KERNEL);
 561         if (!roc)
 562                 return -ENOMEM;
 563
 564         /*
 565          * If the duration is zero, then the driver
 566          * wouldn't actually do anything. Set it to
 567          * 10 for now.
 568          *
 569          * TODO: cancel the off-channel operation
 570          *       when we get the SKB's TX status and
 571          *       the wait time was zero before.
 572          */
 573         if (!duration)
 574                 duration = 10;
 575
 576         roc->chan = channel;
 577         roc->duration = duration;
 578         roc->req_duration = duration;
 579         roc->frame = txskb;
 580         roc->type = type;
 581         roc->sdata = sdata;
 582
 583         /*
 584          * cookie is either the roc cookie (for normal roc)
 585          * or the SKB (for mgmt TX)
 586          */
 587         if (!txskb) {
 588                 roc->cookie = ieee80211_mgmt_tx_cookie(local);
 589                 *cookie = roc->cookie;
 590         } else {
 591                 roc->mgmt_tx_cookie = *cookie;
 592         }
 593
 594         /* if there's no need to queue, handle it immediately */
 595         if (list_empty(&local->roc_list) &&
 596             !local->scanning && !ieee80211_is_radar_required(local)) {
 597                 /* if not HW assist, just queue & schedule work */
 598                 if (!local->ops->remain_on_channel) {
 599                         list_add_tail(&roc->list, &local->roc_list);
 600                         ieee80211_queue_delayed_work(&local->hw,
 601                                                      &local->roc_work, 0);
 602                 } else {
 603                         /* otherwise actually kick it off here
 604                          * (for error handling)
 605                          */
 606                         ret = drv_remain_on_channel(local, sdata, channel,
 607                                                     duration, type);
 608                         if (ret) {
 609                                 kfree(roc);
 610                                 return ret;
 611                         }
 612                         roc->started = true;
 613                         list_add_tail(&roc->list, &local->roc_list);
 614                 }
 615
 616                 return 0;
 617         }
 618
 619         /* otherwise handle queueing */
 620
 621         list_for_each_entry(tmp, &local->roc_list, list) {
 622                 if (tmp->chan != channel || tmp->sdata != sdata)
 623                         continue;
 624
 625                 /*
 626                  * Extend this ROC if possible: If it hasn't started, add
 627                  * just after the new one to combine.
 628                  */
 629                 if (!tmp->started) {
 630                         list_add(&roc->list, &tmp->list);
 631                         queued = true;
 632                         break;
 633                 }
 634
 635                 if (!combine_started)
 636                         continue;
 637
 638                 if (!local->ops->remain_on_channel) {
 639                         /* If there's no hardware remain-on-channel, and
 640                          * doing so won't push us over the maximum r-o-c
 641                          * we allow, then we can just add the new one to
 642                          * the list and mark it as having started now.
 643                          * If it would push over the limit, don't try to
 644                          * combine with other started ones (that haven't
 645                          * been running as long) but potentially sort it
 646                          * with others that had the same fate.
 647                          */
 648                         unsigned long now = jiffies;
 649                         u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
 650                         struct wiphy *wiphy = local->hw.wiphy;
 651                         u32 max_roc = wiphy->max_remain_on_channel_duration;
 652
 653                         if (elapsed + roc->duration > max_roc) {
 654                                 combine_started = false;
 655                                 continue;
 656                         }
 657
 658                         list_add(&roc->list, &tmp->list);
 659                         queued = true;
 660                         roc->on_channel = tmp->on_channel;
 661                         ieee80211_handle_roc_started(roc, now);
 662                         ieee80211_recalc_sw_work(local, now);
 663                         break;
 664                 }
 665
 666                 queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
 667                 if (queued)
 668                         break;
 669                 /* if it wasn't queued, perhaps it can be combined with
 670                  * another that also couldn't get combined previously,
 671                  * but no need to check for already started ones, since
 672                  * that can't work.
 673                  */
 674                 combine_started = false;
 675         }
 676
 677         if (!queued)
 678                 list_add_tail(&roc->list, &local->roc_list);
 679
 680         return 0;
 681 }
 682
 683 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
 684                                 struct ieee80211_channel *chan,
 685                                 unsigned int duration, u64 *cookie)
 686 {
 687         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 688         struct ieee80211_local *local = sdata->local;
 689         int ret;
 690
 691         mutex_lock(&local->mtx);
 692         ret = ieee80211_start_roc_work(local, sdata, chan,
 693                                        duration, cookie, NULL,
 694                                        IEEE80211_ROC_TYPE_NORMAL);
 695         mutex_unlock(&local->mtx);
 696
 697         return ret;
 698 }
 699
 700 static int ieee80211_cancel_roc(struct ieee80211_local *local,
 701                                 u64 cookie, bool mgmt_tx)
 702 {
 703         struct ieee80211_roc_work *roc, *tmp, *found = NULL;
 704         int ret;
 705
 706         if (!cookie)
 707                 return -ENOENT;
 708
 709         mutex_lock(&local->mtx);
 710         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 711                 if (!mgmt_tx && roc->cookie != cookie)
 712                         continue;
 713                 else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
 714                         continue;
 715
 716                 found = roc;
 717                 break;
 718         }
 719
 720         if (!found) {
 721                 mutex_unlock(&local->mtx);
 722                 return -ENOENT;
 723         }
 724
 725         if (!found->started) {
 726                 ieee80211_roc_notify_destroy(found);
 727                 goto out_unlock;
 728         }
 729
 730         if (local->ops->remain_on_channel) {
 731                 ret = drv_cancel_remain_on_channel(local);
 732                 if (WARN_ON_ONCE(ret)) {
 733                         mutex_unlock(&local->mtx);
 734                         return ret;
 735                 }
 736
 737                 /* TODO:
 738                  * if multiple items were combined here then we really shouldn't
 739                  * cancel them all - we should wait for as much time as needed
 740                  * for the longest remaining one, and only then cancel ...
 741                  */
 742                 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 743                         if (!roc->started)
 744                                 break;
 745                         if (roc == found)
 746                                 found = NULL;
 747                         ieee80211_roc_notify_destroy(roc);
 748                 }
 749
 750                 /* that really must not happen - it was started */
 751                 WARN_ON(found);
 752
 753                 ieee80211_start_next_roc(local);
 754         } else {
 755                 /* go through work struct to return to the operating channel */
 756                 found->abort = true;
 757                 mod_delayed_work(local->workqueue, &local->roc_work, 0);
 758         }
 759
 760  out_unlock:
 761         mutex_unlock(&local->mtx);
 762
 763         return 0;
 764 }
 765
 766 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
 767                                        struct wireless_dev *wdev, u64 cookie)
 768 {
 769         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 770         struct ieee80211_local *local = sdata->local;
 771
 772         return ieee80211_cancel_roc(local, cookie, false);
 773 }
 774
 775 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 776                       struct cfg80211_mgmt_tx_params *params, u64 *cookie)
 777 {
 778         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 779         struct ieee80211_local *local = sdata->local;
 780         struct sk_buff *skb;
 781         struct sta_info *sta;
 782         const struct ieee80211_mgmt *mgmt = (void *)params->buf;
 783         bool need_offchan = false;
 784         u32 flags;
 785         int ret;
 786         u8 *data;
 787
 788         if (params->dont_wait_for_ack)
 789                 flags = IEEE80211_TX_CTL_NO_ACK;
 790         else
 791                 flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
 792                         IEEE80211_TX_CTL_REQ_TX_STATUS;
 793
 794         if (params->no_cck)
 795                 flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 796
 797         switch (sdata->vif.type) {
 798         case NL80211_IFTYPE_ADHOC:
 799                 if (!sdata->vif.bss_conf.ibss_joined)
 800                         need_offchan = true;
 801                 /* fall through */
 802 #ifdef CONFIG_MAC80211_MESH
 803         case NL80211_IFTYPE_MESH_POINT:
 804                 if (ieee80211_vif_is_mesh(&sdata->vif) &&
 805                     !sdata->u.mesh.mesh_id_len)
 806                         need_offchan = true;
 807                 /* fall through */
 808 #endif
 809         case NL80211_IFTYPE_AP:
 810         case NL80211_IFTYPE_AP_VLAN:
 811         case NL80211_IFTYPE_P2P_GO:
 812                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 813                     !ieee80211_vif_is_mesh(&sdata->vif) &&
 814                     !rcu_access_pointer(sdata->bss->beacon))
 815                         need_offchan = true;
 816                 if (!ieee80211_is_action(mgmt->frame_control) ||
 817                     mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
 818                     mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
 819                     mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
 820                         break;
 821                 rcu_read_lock();
 822                 sta = sta_info_get(sdata, mgmt->da);
 823                 rcu_read_unlock();
 824                 if (!sta)
 825                         return -ENOLINK;
 826                 break;
 827         case NL80211_IFTYPE_STATION:
 828         case NL80211_IFTYPE_P2P_CLIENT:
 829                 sdata_lock(sdata);
 830                 if (!sdata->u.mgd.associated ||
 831                     (params->offchan && params->wait &&
 832                      local->ops->remain_on_channel &&
 833                      memcmp(sdata->u.mgd.associated->bssid,
 834                             mgmt->bssid, ETH_ALEN)))
 835                         need_offchan = true;
 836                 sdata_unlock(sdata);
 837                 break;
 838         case NL80211_IFTYPE_P2P_DEVICE:
 839                 need_offchan = true;
 840                 break;
 841         default:
 842                 return -EOPNOTSUPP;
 843         }
 844
 845         /* configurations requiring offchan cannot work if no channel has been
 846          * specified
 847          */
 848         if (need_offchan && !params->chan)
 849                 return -EINVAL;
 850
 851         mutex_lock(&local->mtx);
 852
 853         /* Check if the operating channel is the requested channel */
 854         if (!need_offchan) {
 855                 struct ieee80211_chanctx_conf *chanctx_conf;
 856
 857                 rcu_read_lock();
 858                 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 859
 860                 if (chanctx_conf) {
 861                         need_offchan = params->chan &&
 862                                        (params->chan !=
 863                                         chanctx_conf->def.chan);
 864                 } else if (!params->chan) {
 865                         ret = -EINVAL;
 866                         rcu_read_unlock();
 867                         goto out_unlock;
 868                 } else {
 869                         need_offchan = true;
 870                 }
 871                 rcu_read_unlock();
 872         }
 873
 874         if (need_offchan && !params->offchan) {
 875                 ret = -EBUSY;
 876                 goto out_unlock;
 877         }
 878
 879         skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
 880         if (!skb) {
 881                 ret = -ENOMEM;
 882                 goto out_unlock;
 883         }
 884         skb_reserve(skb, local->hw.extra_tx_headroom);
 885
 886         data = skb_put(skb, params->len);
 887         memcpy(data, params->buf, params->len);
 888
 889         /* Update CSA counters */
 890         if (sdata->vif.csa_active &&
 891             (sdata->vif.type == NL80211_IFTYPE_AP ||
 892              sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
 893              sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
 894             params->n_csa_offsets) {
 895                 int i;
 896                 struct beacon_data *beacon = NULL;
 897
 898                 rcu_read_lock();
 899
 900                 if (sdata->vif.type == NL80211_IFTYPE_AP)
 901                         beacon = rcu_dereference(sdata->u.ap.beacon);
 902                 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 903                         beacon = rcu_dereference(sdata->u.ibss.presp);
 904                 else if (ieee80211_vif_is_mesh(&sdata->vif))
 905                         beacon = rcu_dereference(sdata->u.mesh.beacon);
 906
 907                 if (beacon)
 908                         for (i = 0; i < params->n_csa_offsets; i++)
 909                                 data[params->csa_offsets[i]] =
 910                                         beacon->csa_current_counter;
 911
 912                 rcu_read_unlock();
 913         }
 914
 915         IEEE80211_SKB_CB(skb)->flags = flags;
 916
 917         skb->dev = sdata->dev;
 918
 919         if (!params->dont_wait_for_ack) {
 920                 /* make a copy to preserve the frame contents
 921                  * in case of encryption.
 922                  */
 923                 ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
 924                 if (ret) {
 925                         kfree_skb(skb);
 926                         goto out_unlock;
 927                 }
 928         } else {
 929                 /* Assign a dummy non-zero cookie, it's not sent to
 930                  * userspace in this case but we rely on its value
 931                  * internally in the need_offchan case to distinguish
 932                  * mgmt-tx from remain-on-channel.
 933                  */
 934                 *cookie = 0xffffffff;
 935         }
 936
 937         if (!need_offchan) {
 938                 ieee80211_tx_skb(sdata, skb);
 939                 ret = 0;
 940                 goto out_unlock;
 941         }
 942
 943         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
 944                                         IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 945         if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
 946                 IEEE80211_SKB_CB(skb)->hw_queue =
 947                         local->hw.offchannel_tx_hw_queue;
 948
 949         /* This will handle all kinds of coalescing and immediate TX */
 950         ret = ieee80211_start_roc_work(local, sdata, params->chan,
 951                                        params->wait, cookie, skb,
 952                                        IEEE80211_ROC_TYPE_MGMT_TX);
 953         if (ret)
 954                 ieee80211_free_txskb(&local->hw, skb);
 955  out_unlock:
 956         mutex_unlock(&local->mtx);
 957         return ret;
 958 }
 959
 960 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
 961                                   struct wireless_dev *wdev, u64 cookie)
 962 {
 963         struct ieee80211_local *local = wiphy_priv(wiphy);
 964
 965         return ieee80211_cancel_roc(local, cookie, true);
 966 }
 967
 968 void ieee80211_roc_setup(struct ieee80211_local *local)
 969 {
 970         INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
 971         INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
 972         INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
 973         INIT_LIST_HEAD(&local->roc_list);
 974 }
 975
 976 void ieee80211_roc_purge(struct ieee80211_local *local,
 977                          struct ieee80211_sub_if_data *sdata)
 978 {
 979         struct ieee80211_roc_work *roc, *tmp;
 980         bool work_to_do = false;
 981
 982         mutex_lock(&local->mtx);
 983         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 984                 if (sdata && roc->sdata != sdata)
 985                         continue;
 986
 987                 if (roc->started) {
 988                         if (local->ops->remain_on_channel) {
 989                                 /* can race, so ignore return value */
 990                                 drv_cancel_remain_on_channel(local);
 991                                 ieee80211_roc_notify_destroy(roc);
 992                         } else {
 993                                 roc->abort = true;
 994                                 work_to_do = true;
 995                         }
 996                 } else {
 997                         ieee80211_roc_notify_destroy(roc);
 998                 }
 999         }
1000         if (work_to_do)
1001                 __ieee80211_roc_work(local);
1002         mutex_unlock(&local->mtx);
1003 }