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