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