net/mac80211/offchannel.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Off-channel operation helpers
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2004, Instant802 Networks, Inc.
   7  * Copyright 2005, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2009       Johannes Berg <johannes@sipsolutions.net>
  11  */
  12 #include <linux/export.h>
  13 #include <net/mac80211.h>
  14 #include "ieee80211_i.h"
  15 #include "driver-ops.h"
  16
  17 /*
  18  * Tell our hardware to disable PS.
  19  * Optionally inform AP that we will go to sleep so that it will buffer
  20  * the frames while we are doing off-channel work.  This is optional
  21  * because we *may* be doing work on-operating channel, and want our
  22  * hardware unconditionally awake, but still let the AP send us normal frames.
  23  */
  24 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
  25 {
  26         struct ieee80211_local *local = sdata->local;
  27         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  28
  29         local->offchannel_ps_enabled = false;
  30
  31         /* FIXME: what to do when local->pspolling is true? */
  32
  33         del_timer_sync(&local->dynamic_ps_timer);
  34         del_timer_sync(&ifmgd->bcn_mon_timer);
  35         del_timer_sync(&ifmgd->conn_mon_timer);
  36
  37         cancel_work_sync(&local->dynamic_ps_enable_work);
  38
  39         if (local->hw.conf.flags & IEEE80211_CONF_PS) {
  40                 local->offchannel_ps_enabled = true;
  41                 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
  42                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
  43         }
  44
  45         if (!local->offchannel_ps_enabled ||
  46             !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
  47                 /*
  48                  * If power save was enabled, no need to send a nullfunc
  49                  * frame because AP knows that we are sleeping. But if the
  50                  * hardware is creating the nullfunc frame for power save
  51                  * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
  52                  * enabled) and power save was enabled, the firmware just
  53                  * sent a null frame with power save disabled. So we need
  54                  * to send a new nullfunc frame to inform the AP that we
  55                  * are again sleeping.
  56                  */
  57                 ieee80211_send_nullfunc(local, sdata, true);
  58 }
  59
  60 /* inform AP that we are awake again, unless power save is enabled */
  61 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
  62 {
  63         struct ieee80211_local *local = sdata->local;
  64
  65         if (!local->ps_sdata)
  66                 ieee80211_send_nullfunc(local, sdata, false);
  67         else if (local->offchannel_ps_enabled) {
  68                 /*
  69                  * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
  70                  * will send a nullfunc frame with the powersave bit set
  71                  * even though the AP already knows that we are sleeping.
  72                  * This could be avoided by sending a null frame with power
  73                  * save bit disabled before enabling the power save, but
  74                  * this doesn't gain anything.
  75                  *
  76                  * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
  77                  * to send a nullfunc frame because AP already knows that
  78                  * we are sleeping, let's just enable power save mode in
  79                  * hardware.
  80                  */
  81                 /* TODO:  Only set hardware if CONF_PS changed?
  82                  * TODO:  Should we set offchannel_ps_enabled to false?
  83                  */
  84                 local->hw.conf.flags |= IEEE80211_CONF_PS;
  85                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
  86         } else if (local->hw.conf.dynamic_ps_timeout > 0) {
  87                 /*
  88                  * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
  89                  * had been running before leaving the operating channel,
  90                  * restart the timer now and send a nullfunc frame to inform
  91                  * the AP that we are awake.
  92                  */
  93                 ieee80211_send_nullfunc(local, sdata, false);
  94                 mod_timer(&local->dynamic_ps_timer, jiffies +
  95                           msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
  96         }
  97
  98         ieee80211_sta_reset_beacon_monitor(sdata);
  99         ieee80211_sta_reset_conn_monitor(sdata);
 100 }
 101
 102 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
 103 {
 104         struct ieee80211_sub_if_data *sdata;
 105
 106         if (WARN_ON(local->use_chanctx))
 107                 return;
 108
 109         /*
 110          * notify the AP about us leaving the channel and stop all
 111          * STA interfaces.
 112          */
 113
 114         /*
 115          * Stop queues and transmit all frames queued by the driver
 116          * before sending nullfunc to enable powersave at the AP.
 117          */
 118         ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
 119                                         IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
 120                                         false);
 121         ieee80211_flush_queues(local, NULL, false);
 122
 123         mutex_lock(&local->iflist_mtx);
 124         list_for_each_entry(sdata, &local->interfaces, list) {
 125                 if (!ieee80211_sdata_running(sdata))
 126                         continue;
 127
 128                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
 129                     sdata->vif.type == NL80211_IFTYPE_NAN)
 130                         continue;
 131
 132                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 133                         set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 134
 135                 /* Check to see if we should disable beaconing. */
 136                 if (sdata->vif.bss_conf.enable_beacon) {
 137                         set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
 138                                 &sdata->state);
 139                         sdata->vif.bss_conf.enable_beacon = false;
 140                         ieee80211_bss_info_change_notify(
 141                                 sdata, BSS_CHANGED_BEACON_ENABLED);
 142                 }
 143
 144                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 145                     sdata->u.mgd.associated)
 146                         ieee80211_offchannel_ps_enable(sdata);
 147         }
 148         mutex_unlock(&local->iflist_mtx);
 149 }
 150
 151 void ieee80211_offchannel_return(struct ieee80211_local *local)
 152 {
 153         struct ieee80211_sub_if_data *sdata;
 154
 155         if (WARN_ON(local->use_chanctx))
 156                 return;
 157
 158         mutex_lock(&local->iflist_mtx);
 159         list_for_each_entry(sdata, &local->interfaces, list) {
 160                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
 161                         continue;
 162
 163                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 164                         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 165
 166                 if (!ieee80211_sdata_running(sdata))
 167                         continue;
 168
 169                 /* Tell AP we're back */
 170                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 171                     sdata->u.mgd.associated)
 172                         ieee80211_offchannel_ps_disable(sdata);
 173
 174                 if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
 175                                        &sdata->state)) {
 176                         sdata->vif.bss_conf.enable_beacon = true;
 177                         ieee80211_bss_info_change_notify(
 178                                 sdata, BSS_CHANGED_BEACON_ENABLED);
 179                 }
 180         }
 181         mutex_unlock(&local->iflist_mtx);
 182
 183         ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
 184                                         IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
 185                                         false);
 186 }
 187
 188 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
 189 {
 190         /* was never transmitted */
 191         if (roc->frame) {
 192                 cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
 193                                         roc->frame->data, roc->frame->len,
 194                                         false, GFP_KERNEL);
 195                 ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
 196         }
 197
 198         if (!roc->mgmt_tx_cookie)
 199                 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
 200                                                    roc->cookie, roc->chan,
 201                                                    GFP_KERNEL);
 202
 203         list_del(&roc->list);
 204         kfree(roc);
 205 }
 206
 207 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
 208                                                  unsigned long now)
 209 {
 210         struct ieee80211_roc_work *roc, *tmp;
 211         long remaining_dur_min = LONG_MAX;
 212
 213         lockdep_assert_held(&local->mtx);
 214
 215         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 216                 long remaining;
 217
 218                 if (!roc->started)
 219                         break;
 220
 221                 remaining = roc->start_time +
 222                             msecs_to_jiffies(roc->duration) -
 223                             now;
 224
 225                 /* In case of HW ROC, it is possible that the HW finished the
 226                  * ROC session before the actual requested time. In such a case
 227                  * end the ROC session (disregarding the remaining time).
 228                  */
 229                 if (roc->abort || roc->hw_begun || remaining <= 0)
 230                         ieee80211_roc_notify_destroy(roc);
 231                 else
 232                         remaining_dur_min = min(remaining_dur_min, remaining);
 233         }
 234
 235         return remaining_dur_min;
 236 }
 237
 238 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
 239                                      unsigned long now)
 240 {
 241         long dur = ieee80211_end_finished_rocs(local, now);
 242
 243         if (dur == LONG_MAX)
 244                 return false;
 245
 246         mod_delayed_work(local->workqueue, &local->roc_work, dur);
 247         return true;
 248 }
 249
 250 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
 251                                          unsigned long start_time)
 252 {
 253         if (WARN_ON(roc->notified))
 254                 return;
 255
 256         roc->start_time = start_time;
 257         roc->started = true;
 258
 259         if (roc->mgmt_tx_cookie) {
 260                 if (!WARN_ON(!roc->frame)) {
 261                         ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
 262                                                   roc->chan->band, 0);
 263                         roc->frame = NULL;
 264                 }
 265         } else {
 266                 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
 267                                           roc->chan, roc->req_duration,
 268                                           GFP_KERNEL);
 269         }
 270
 271         roc->notified = true;
 272 }
 273
 274 static void ieee80211_hw_roc_start(struct work_struct *work)
 275 {
 276         struct ieee80211_local *local =
 277                 container_of(work, struct ieee80211_local, hw_roc_start);
 278         struct ieee80211_roc_work *roc;
 279
 280         mutex_lock(&local->mtx);
 281
 282         list_for_each_entry(roc, &local->roc_list, list) {
 283                 if (!roc->started)
 284                         break;
 285
 286                 roc->hw_begun = true;
 287                 ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
 288         }
 289
 290         mutex_unlock(&local->mtx);
 291 }
 292
 293 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
 294 {
 295         struct ieee80211_local *local = hw_to_local(hw);
 296
 297         local->hw_roc_start_time = jiffies;
 298
 299         trace_api_ready_on_channel(local);
 300
 301         ieee80211_queue_work(hw, &local->hw_roc_start);
 302 }
 303 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
 304
 305 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
 306 {
 307         struct ieee80211_roc_work *roc, *tmp;
 308         enum ieee80211_roc_type type;
 309         u32 min_dur, max_dur;
 310
 311         lockdep_assert_held(&local->mtx);
 312
 313         if (WARN_ON(list_empty(&local->roc_list)))
 314                 return;
 315
 316         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 317                                list);
 318
 319         if (WARN_ON(roc->started))
 320                 return;
 321
 322         min_dur = roc->duration;
 323         max_dur = roc->duration;
 324         type = roc->type;
 325
 326         list_for_each_entry(tmp, &local->roc_list, list) {
 327                 if (tmp == roc)
 328                         continue;
 329                 if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 330                         break;
 331                 max_dur = max(tmp->duration, max_dur);
 332                 min_dur = min(tmp->duration, min_dur);
 333                 type = max(tmp->type, type);
 334         }
 335
 336         if (local->ops->remain_on_channel) {
 337                 int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
 338                                                 max_dur, type);
 339
 340                 if (ret) {
 341                         wiphy_warn(local->hw.wiphy,
 342                                    "failed to start next HW ROC (%d)\n", ret);
 343                         /*
 344                          * queue the work struct again to avoid recursion
 345                          * when multiple failures occur
 346                          */
 347                         list_for_each_entry(tmp, &local->roc_list, list) {
 348                                 if (tmp->sdata != roc->sdata ||
 349                                     tmp->chan != roc->chan)
 350                                         break;
 351                                 tmp->started = true;
 352                                 tmp->abort = true;
 353                         }
 354                         ieee80211_queue_work(&local->hw, &local->hw_roc_done);
 355                         return;
 356                 }
 357
 358                 /* we'll notify about the start once the HW calls back */
 359                 list_for_each_entry(tmp, &local->roc_list, list) {
 360                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 361                                 break;
 362                         tmp->started = true;
 363                 }
 364         } else {
 365                 /* If actually operating on the desired channel (with at least
 366                  * 20 MHz channel width) don't stop all the operations but still
 367                  * treat it as though the ROC operation started properly, so
 368                  * other ROC operations won't interfere with this one.
 369                  */
 370                 roc->on_channel = roc->chan == local->_oper_chandef.chan &&
 371                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
 372                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
 373
 374                 /* start this ROC */
 375                 ieee80211_recalc_idle(local);
 376
 377                 if (!roc->on_channel) {
 378                         ieee80211_offchannel_stop_vifs(local);
 379
 380                         local->tmp_channel = roc->chan;
 381                         ieee80211_hw_config(local, 0);
 382                 }
 383
 384                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 385                                              msecs_to_jiffies(min_dur));
 386
 387                 /* tell userspace or send frame(s) */
 388                 list_for_each_entry(tmp, &local->roc_list, list) {
 389                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 390                                 break;
 391
 392                         tmp->on_channel = roc->on_channel;
 393                         ieee80211_handle_roc_started(tmp, jiffies);
 394                 }
 395         }
 396 }
 397
 398 void ieee80211_start_next_roc(struct ieee80211_local *local)
 399 {
 400         struct ieee80211_roc_work *roc;
 401
 402         lockdep_assert_held(&local->mtx);
 403
 404         if (list_empty(&local->roc_list)) {
 405                 ieee80211_run_deferred_scan(local);
 406                 return;
 407         }
 408
 409         /* defer roc if driver is not started (i.e. during reconfig) */
 410         if (local->in_reconfig)
 411                 return;
 412
 413         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 414                                list);
 415
 416         if (WARN_ON_ONCE(roc->started))
 417                 return;
 418
 419         if (local->ops->remain_on_channel) {
 420                 _ieee80211_start_next_roc(local);
 421         } else {
 422                 /* delay it a bit */
 423                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 424                                              round_jiffies_relative(HZ/2));
 425         }
 426 }
 427
 428 static void __ieee80211_roc_work(struct ieee80211_local *local)
 429 {
 430         struct ieee80211_roc_work *roc;
 431         bool on_channel;
 432
 433         lockdep_assert_held(&local->mtx);
 434
 435         if (WARN_ON(local->ops->remain_on_channel))
 436                 return;
 437
 438         roc = list_first_entry_or_null(&local->roc_list,
 439                                        struct ieee80211_roc_work, list);
 440         if (!roc)
 441                 return;
 442
 443         if (!roc->started) {
 444                 WARN_ON(local->use_chanctx);
 445                 _ieee80211_start_next_roc(local);
 446         } else {
 447                 on_channel = roc->on_channel;
 448                 if (ieee80211_recalc_sw_work(local, jiffies))
 449                         return;
 450
 451                 /* careful - roc pointer became invalid during recalc */
 452
 453                 if (!on_channel) {
 454                         ieee80211_flush_queues(local, NULL, false);
 455
 456                         local->tmp_channel = NULL;
 457                         ieee80211_hw_config(local, 0);
 458
 459                         ieee80211_offchannel_return(local);
 460                 }
 461
 462                 ieee80211_recalc_idle(local);
 463                 ieee80211_start_next_roc(local);
 464         }
 465 }
 466
 467 static void ieee80211_roc_work(struct work_struct *work)
 468 {
 469         struct ieee80211_local *local =
 470                 container_of(work, struct ieee80211_local, roc_work.work);
 471
 472         mutex_lock(&local->mtx);
 473         __ieee80211_roc_work(local);
 474         mutex_unlock(&local->mtx);
 475 }
 476
 477 static void ieee80211_hw_roc_done(struct work_struct *work)
 478 {
 479         struct ieee80211_local *local =
 480                 container_of(work, struct ieee80211_local, hw_roc_done);
 481
 482         mutex_lock(&local->mtx);
 483
 484         ieee80211_end_finished_rocs(local, jiffies);
 485
 486         /* if there's another roc, start it now */
 487         ieee80211_start_next_roc(local);
 488
 489         mutex_unlock(&local->mtx);
 490 }
 491
 492 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
 493 {
 494         struct ieee80211_local *local = hw_to_local(hw);
 495
 496         trace_api_remain_on_channel_expired(local);
 497
 498         ieee80211_queue_work(hw, &local->hw_roc_done);
 499 }
 500 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
 501
 502 static bool
 503 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
 504                                   struct ieee80211_roc_work *new_roc,
 505                                   struct ieee80211_roc_work *cur_roc)
 506 {
 507         unsigned long now = jiffies;
 508         unsigned long remaining;
 509
 510         if (WARN_ON(!cur_roc->started))
 511                 return false;
 512
 513         /* if it was scheduled in the hardware, but not started yet,
 514          * we can only combine if the older one had a longer duration
 515          */
 516         if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
 517                 return false;
 518
 519         remaining = cur_roc->start_time +
 520                     msecs_to_jiffies(cur_roc->duration) -
 521                     now;
 522
 523         /* if it doesn't fit entirely, schedule a new one */
 524         if (new_roc->duration > jiffies_to_msecs(remaining))
 525                 return false;
 526
 527         /* add just after the current one so we combine their finish later */
 528         list_add(&new_roc->list, &cur_roc->list);
 529
 530         /* if the existing one has already begun then let this one also
 531          * begin, otherwise they'll both be marked properly by the work
 532          * struct that runs once the driver notifies us of the beginning
 533          */
 534         if (cur_roc->hw_begun) {
 535                 new_roc->hw_begun = true;
 536                 ieee80211_handle_roc_started(new_roc, now);
 537         }
 538
 539         return true;
 540 }
 541
 542 static int ieee80211_start_roc_work(struct ieee80211_local *local,
 543                                     struct ieee80211_sub_if_data *sdata,
 544                                     struct ieee80211_channel *channel,
 545                                     unsigned int duration, u64 *cookie,
 546                                     struct sk_buff *txskb,
 547                                     enum ieee80211_roc_type type)
 548 {
 549         struct ieee80211_roc_work *roc, *tmp;
 550         bool queued = false, combine_started = true;
 551         int ret;
 552
 553         lockdep_assert_held(&local->mtx);
 554
 555         if (local->use_chanctx && !local->ops->remain_on_channel)
 556                 return -EOPNOTSUPP;
 557
 558         roc = kzalloc(sizeof(*roc), GFP_KERNEL);
 559         if (!roc)
 560                 return -ENOMEM;
 561
 562         /*
 563          * If the duration is zero, then the driver
 564          * wouldn't actually do anything. Set it to
 565          * 10 for now.
 566          *
 567          * TODO: cancel the off-channel operation
 568          *       when we get the SKB's TX status and
 569          *       the wait time was zero before.
 570          */
 571         if (!duration)
 572                 duration = 10;
 573
 574         roc->chan = channel;
 575         roc->duration = duration;
 576         roc->req_duration = duration;
 577         roc->frame = txskb;
 578         roc->type = type;
 579         roc->sdata = sdata;
 580
 581         /*
 582          * cookie is either the roc cookie (for normal roc)
 583          * or the SKB (for mgmt TX)
 584          */
 585         if (!txskb) {
 586                 roc->cookie = ieee80211_mgmt_tx_cookie(local);
 587                 *cookie = roc->cookie;
 588         } else {
 589                 roc->mgmt_tx_cookie = *cookie;
 590         }
 591
 592         /* if there's no need to queue, handle it immediately */
 593         if (list_empty(&local->roc_list) &&
 594             !local->scanning && !ieee80211_is_radar_required(local)) {
 595                 /* if not HW assist, just queue & schedule work */
 596                 if (!local->ops->remain_on_channel) {
 597                         list_add_tail(&roc->list, &local->roc_list);
 598                         ieee80211_queue_delayed_work(&local->hw,
 599                                                      &local->roc_work, 0);
 600                 } else {
 601                         /* otherwise actually kick it off here
 602                          * (for error handling)
 603                          */
 604                         ret = drv_remain_on_channel(local, sdata, channel,
 605                                                     duration, type);
 606                         if (ret) {
 607                                 kfree(roc);
 608                                 return ret;
 609                         }
 610                         roc->started = true;
 611                         list_add_tail(&roc->list, &local->roc_list);
 612                 }
 613
 614                 return 0;
 615         }
 616
 617         /* otherwise handle queueing */
 618
 619         list_for_each_entry(tmp, &local->roc_list, list) {
 620                 if (tmp->chan != channel || tmp->sdata != sdata)
 621                         continue;
 622
 623                 /*
 624                  * Extend this ROC if possible: If it hasn't started, add
 625                  * just after the new one to combine.
 626                  */
 627                 if (!tmp->started) {
 628                         list_add(&roc->list, &tmp->list);
 629                         queued = true;
 630                         break;
 631                 }
 632
 633                 if (!combine_started)
 634                         continue;
 635
 636                 if (!local->ops->remain_on_channel) {
 637                         /* If there's no hardware remain-on-channel, and
 638                          * doing so won't push us over the maximum r-o-c
 639                          * we allow, then we can just add the new one to
 640                          * the list and mark it as having started now.
 641                          * If it would push over the limit, don't try to
 642                          * combine with other started ones (that haven't
 643                          * been running as long) but potentially sort it
 644                          * with others that had the same fate.
 645                          */
 646                         unsigned long now = jiffies;
 647                         u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
 648                         struct wiphy *wiphy = local->hw.wiphy;
 649                         u32 max_roc = wiphy->max_remain_on_channel_duration;
 650
 651                         if (elapsed + roc->duration > max_roc) {
 652                                 combine_started = false;
 653                                 continue;
 654                         }
 655
 656                         list_add(&roc->list, &tmp->list);
 657                         queued = true;
 658                         roc->on_channel = tmp->on_channel;
 659                         ieee80211_handle_roc_started(roc, now);
 660                         ieee80211_recalc_sw_work(local, 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         flush_work(&local->hw_roc_start);
 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 #ifdef CONFIG_MAC80211_MESH
 802                 /* fall through */
 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 #endif
 808                 /* fall through */
 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_bss(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         case NL80211_IFTYPE_NAN:
 842         default:
 843                 return -EOPNOTSUPP;
 844         }
 845
 846         /* configurations requiring offchan cannot work if no channel has been
 847          * specified
 848          */
 849         if (need_offchan && !params->chan)
 850                 return -EINVAL;
 851
 852         mutex_lock(&local->mtx);
 853
 854         /* Check if the operating channel is the requested channel */
 855         if (!need_offchan) {
 856                 struct ieee80211_chanctx_conf *chanctx_conf;
 857
 858                 rcu_read_lock();
 859                 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 860
 861                 if (chanctx_conf) {
 862                         need_offchan = params->chan &&
 863                                        (params->chan !=
 864                                         chanctx_conf->def.chan);
 865                 } else if (!params->chan) {
 866                         ret = -EINVAL;
 867                         rcu_read_unlock();
 868                         goto out_unlock;
 869                 } else {
 870                         need_offchan = true;
 871                 }
 872                 rcu_read_unlock();
 873         }
 874
 875         if (need_offchan && !params->offchan) {
 876                 ret = -EBUSY;
 877                 goto out_unlock;
 878         }
 879
 880         skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
 881         if (!skb) {
 882                 ret = -ENOMEM;
 883                 goto out_unlock;
 884         }
 885         skb_reserve(skb, local->hw.extra_tx_headroom);
 886
 887         data = skb_put_data(skb, 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 }