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  * Copyright (C) 2019 Intel Corporation
  12  */
  13 #include <linux/export.h>
  14 #include <net/mac80211.h>
  15 #include "ieee80211_i.h"
  16 #include "driver-ops.h"
  17
  18 /*
  19  * Tell our hardware to disable PS.
  20  * Optionally inform AP that we will go to sleep so that it will buffer
  21  * the frames while we are doing off-channel work.  This is optional
  22  * because we *may* be doing work on-operating channel, and want our
  23  * hardware unconditionally awake, but still let the AP send us normal frames.
  24  */
  25 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
  26 {
  27         struct ieee80211_local *local = sdata->local;
  28         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
  29
  30         local->offchannel_ps_enabled = false;
  31
  32         /* FIXME: what to do when local->pspolling is true? */
  33
  34         del_timer_sync(&local->dynamic_ps_timer);
  35         del_timer_sync(&ifmgd->bcn_mon_timer);
  36         del_timer_sync(&ifmgd->conn_mon_timer);
  37
  38         cancel_work_sync(&local->dynamic_ps_enable_work);
  39
  40         if (local->hw.conf.flags & IEEE80211_CONF_PS) {
  41                 local->offchannel_ps_enabled = true;
  42                 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
  43                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
  44         }
  45
  46         if (!local->offchannel_ps_enabled ||
  47             !ieee80211_hw_check(&local->hw, PS_NULLFUNC_STACK))
  48                 /*
  49                  * If power save was enabled, no need to send a nullfunc
  50                  * frame because AP knows that we are sleeping. But if the
  51                  * hardware is creating the nullfunc frame for power save
  52                  * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
  53                  * enabled) and power save was enabled, the firmware just
  54                  * sent a null frame with power save disabled. So we need
  55                  * to send a new nullfunc frame to inform the AP that we
  56                  * are again sleeping.
  57                  */
  58                 ieee80211_send_nullfunc(local, sdata, true);
  59 }
  60
  61 /* inform AP that we are awake again, unless power save is enabled */
  62 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
  63 {
  64         struct ieee80211_local *local = sdata->local;
  65
  66         if (!local->ps_sdata)
  67                 ieee80211_send_nullfunc(local, sdata, false);
  68         else if (local->offchannel_ps_enabled) {
  69                 /*
  70                  * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
  71                  * will send a nullfunc frame with the powersave bit set
  72                  * even though the AP already knows that we are sleeping.
  73                  * This could be avoided by sending a null frame with power
  74                  * save bit disabled before enabling the power save, but
  75                  * this doesn't gain anything.
  76                  *
  77                  * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
  78                  * to send a nullfunc frame because AP already knows that
  79                  * we are sleeping, let's just enable power save mode in
  80                  * hardware.
  81                  */
  82                 /* TODO:  Only set hardware if CONF_PS changed?
  83                  * TODO:  Should we set offchannel_ps_enabled to false?
  84                  */
  85                 local->hw.conf.flags |= IEEE80211_CONF_PS;
  86                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
  87         } else if (local->hw.conf.dynamic_ps_timeout > 0) {
  88                 /*
  89                  * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
  90                  * had been running before leaving the operating channel,
  91                  * restart the timer now and send a nullfunc frame to inform
  92                  * the AP that we are awake.
  93                  */
  94                 ieee80211_send_nullfunc(local, sdata, false);
  95                 mod_timer(&local->dynamic_ps_timer, jiffies +
  96                           msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
  97         }
  98
  99         ieee80211_sta_reset_beacon_monitor(sdata);
 100         ieee80211_sta_reset_conn_monitor(sdata);
 101 }
 102
 103 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
 104 {
 105         struct ieee80211_sub_if_data *sdata;
 106
 107         if (WARN_ON(local->use_chanctx))
 108                 return;
 109
 110         /*
 111          * notify the AP about us leaving the channel and stop all
 112          * STA interfaces.
 113          */
 114
 115         /*
 116          * Stop queues and transmit all frames queued by the driver
 117          * before sending nullfunc to enable powersave at the AP.
 118          */
 119         ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
 120                                         IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
 121                                         false);
 122         ieee80211_flush_queues(local, NULL, false);
 123
 124         mutex_lock(&local->iflist_mtx);
 125         list_for_each_entry(sdata, &local->interfaces, list) {
 126                 if (!ieee80211_sdata_running(sdata))
 127                         continue;
 128
 129                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
 130                     sdata->vif.type == NL80211_IFTYPE_NAN)
 131                         continue;
 132
 133                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 134                         set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 135
 136                 /* Check to see if we should disable beaconing. */
 137                 if (sdata->vif.bss_conf.enable_beacon) {
 138                         set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
 139                                 &sdata->state);
 140                         sdata->vif.bss_conf.enable_beacon = false;
 141                         ieee80211_bss_info_change_notify(
 142                                 sdata, BSS_CHANGED_BEACON_ENABLED);
 143                 }
 144
 145                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 146                     sdata->u.mgd.associated)
 147                         ieee80211_offchannel_ps_enable(sdata);
 148         }
 149         mutex_unlock(&local->iflist_mtx);
 150 }
 151
 152 void ieee80211_offchannel_return(struct ieee80211_local *local)
 153 {
 154         struct ieee80211_sub_if_data *sdata;
 155
 156         if (WARN_ON(local->use_chanctx))
 157                 return;
 158
 159         mutex_lock(&local->iflist_mtx);
 160         list_for_each_entry(sdata, &local->interfaces, list) {
 161                 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
 162                         continue;
 163
 164                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
 165                         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
 166
 167                 if (!ieee80211_sdata_running(sdata))
 168                         continue;
 169
 170                 /* Tell AP we're back */
 171                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 172                     sdata->u.mgd.associated)
 173                         ieee80211_offchannel_ps_disable(sdata);
 174
 175                 if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
 176                                        &sdata->state)) {
 177                         sdata->vif.bss_conf.enable_beacon = true;
 178                         ieee80211_bss_info_change_notify(
 179                                 sdata, BSS_CHANGED_BEACON_ENABLED);
 180                 }
 181         }
 182         mutex_unlock(&local->iflist_mtx);
 183
 184         ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
 185                                         IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
 186                                         false);
 187 }
 188
 189 static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
 190 {
 191         /* was never transmitted */
 192         if (roc->frame) {
 193                 cfg80211_mgmt_tx_status(&roc->sdata->wdev, roc->mgmt_tx_cookie,
 194                                         roc->frame->data, roc->frame->len,
 195                                         false, GFP_KERNEL);
 196                 ieee80211_free_txskb(&roc->sdata->local->hw, roc->frame);
 197         }
 198
 199         if (!roc->mgmt_tx_cookie)
 200                 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
 201                                                    roc->cookie, roc->chan,
 202                                                    GFP_KERNEL);
 203         else
 204                 cfg80211_tx_mgmt_expired(&roc->sdata->wdev,
 205                                          roc->mgmt_tx_cookie,
 206                                          roc->chan, GFP_KERNEL);
 207
 208         list_del(&roc->list);
 209         kfree(roc);
 210 }
 211
 212 static unsigned long ieee80211_end_finished_rocs(struct ieee80211_local *local,
 213                                                  unsigned long now)
 214 {
 215         struct ieee80211_roc_work *roc, *tmp;
 216         long remaining_dur_min = LONG_MAX;
 217
 218         lockdep_assert_held(&local->mtx);
 219
 220         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 221                 long remaining;
 222
 223                 if (!roc->started)
 224                         break;
 225
 226                 remaining = roc->start_time +
 227                             msecs_to_jiffies(roc->duration) -
 228                             now;
 229
 230                 /* In case of HW ROC, it is possible that the HW finished the
 231                  * ROC session before the actual requested time. In such a case
 232                  * end the ROC session (disregarding the remaining time).
 233                  */
 234                 if (roc->abort || roc->hw_begun || remaining <= 0)
 235                         ieee80211_roc_notify_destroy(roc);
 236                 else
 237                         remaining_dur_min = min(remaining_dur_min, remaining);
 238         }
 239
 240         return remaining_dur_min;
 241 }
 242
 243 static bool ieee80211_recalc_sw_work(struct ieee80211_local *local,
 244                                      unsigned long now)
 245 {
 246         long dur = ieee80211_end_finished_rocs(local, now);
 247
 248         if (dur == LONG_MAX)
 249                 return false;
 250
 251         mod_delayed_work(local->workqueue, &local->roc_work, dur);
 252         return true;
 253 }
 254
 255 static void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc,
 256                                          unsigned long start_time)
 257 {
 258         if (WARN_ON(roc->notified))
 259                 return;
 260
 261         roc->start_time = start_time;
 262         roc->started = 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
 279 static void ieee80211_hw_roc_start(struct work_struct *work)
 280 {
 281         struct ieee80211_local *local =
 282                 container_of(work, struct ieee80211_local, hw_roc_start);
 283         struct ieee80211_roc_work *roc;
 284
 285         mutex_lock(&local->mtx);
 286
 287         list_for_each_entry(roc, &local->roc_list, list) {
 288                 if (!roc->started)
 289                         break;
 290
 291                 roc->hw_begun = true;
 292                 ieee80211_handle_roc_started(roc, local->hw_roc_start_time);
 293         }
 294
 295         mutex_unlock(&local->mtx);
 296 }
 297
 298 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
 299 {
 300         struct ieee80211_local *local = hw_to_local(hw);
 301
 302         local->hw_roc_start_time = jiffies;
 303
 304         trace_api_ready_on_channel(local);
 305
 306         ieee80211_queue_work(hw, &local->hw_roc_start);
 307 }
 308 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
 309
 310 static void _ieee80211_start_next_roc(struct ieee80211_local *local)
 311 {
 312         struct ieee80211_roc_work *roc, *tmp;
 313         enum ieee80211_roc_type type;
 314         u32 min_dur, max_dur;
 315
 316         lockdep_assert_held(&local->mtx);
 317
 318         if (WARN_ON(list_empty(&local->roc_list)))
 319                 return;
 320
 321         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 322                                list);
 323
 324         if (WARN_ON(roc->started))
 325                 return;
 326
 327         min_dur = roc->duration;
 328         max_dur = roc->duration;
 329         type = roc->type;
 330
 331         list_for_each_entry(tmp, &local->roc_list, list) {
 332                 if (tmp == roc)
 333                         continue;
 334                 if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 335                         break;
 336                 max_dur = max(tmp->duration, max_dur);
 337                 min_dur = min(tmp->duration, min_dur);
 338                 type = max(tmp->type, type);
 339         }
 340
 341         if (local->ops->remain_on_channel) {
 342                 int ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
 343                                                 max_dur, type);
 344
 345                 if (ret) {
 346                         wiphy_warn(local->hw.wiphy,
 347                                    "failed to start next HW ROC (%d)\n", ret);
 348                         /*
 349                          * queue the work struct again to avoid recursion
 350                          * when multiple failures occur
 351                          */
 352                         list_for_each_entry(tmp, &local->roc_list, list) {
 353                                 if (tmp->sdata != roc->sdata ||
 354                                     tmp->chan != roc->chan)
 355                                         break;
 356                                 tmp->started = true;
 357                                 tmp->abort = true;
 358                         }
 359                         ieee80211_queue_work(&local->hw, &local->hw_roc_done);
 360                         return;
 361                 }
 362
 363                 /* we'll notify about the start once the HW calls back */
 364                 list_for_each_entry(tmp, &local->roc_list, list) {
 365                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 366                                 break;
 367                         tmp->started = true;
 368                 }
 369         } else {
 370                 /* If actually operating on the desired channel (with at least
 371                  * 20 MHz channel width) don't stop all the operations but still
 372                  * treat it as though the ROC operation started properly, so
 373                  * other ROC operations won't interfere with this one.
 374                  */
 375                 roc->on_channel = roc->chan == local->_oper_chandef.chan &&
 376                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
 377                                   local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
 378
 379                 /* start this ROC */
 380                 ieee80211_recalc_idle(local);
 381
 382                 if (!roc->on_channel) {
 383                         ieee80211_offchannel_stop_vifs(local);
 384
 385                         local->tmp_channel = roc->chan;
 386                         ieee80211_hw_config(local, 0);
 387                 }
 388
 389                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 390                                              msecs_to_jiffies(min_dur));
 391
 392                 /* tell userspace or send frame(s) */
 393                 list_for_each_entry(tmp, &local->roc_list, list) {
 394                         if (tmp->sdata != roc->sdata || tmp->chan != roc->chan)
 395                                 break;
 396
 397                         tmp->on_channel = roc->on_channel;
 398                         ieee80211_handle_roc_started(tmp, jiffies);
 399                 }
 400         }
 401 }
 402
 403 void ieee80211_start_next_roc(struct ieee80211_local *local)
 404 {
 405         struct ieee80211_roc_work *roc;
 406
 407         lockdep_assert_held(&local->mtx);
 408
 409         if (list_empty(&local->roc_list)) {
 410                 ieee80211_run_deferred_scan(local);
 411                 return;
 412         }
 413
 414         /* defer roc if driver is not started (i.e. during reconfig) */
 415         if (local->in_reconfig)
 416                 return;
 417
 418         roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
 419                                list);
 420
 421         if (WARN_ON_ONCE(roc->started))
 422                 return;
 423
 424         if (local->ops->remain_on_channel) {
 425                 _ieee80211_start_next_roc(local);
 426         } else {
 427                 /* delay it a bit */
 428                 ieee80211_queue_delayed_work(&local->hw, &local->roc_work,
 429                                              round_jiffies_relative(HZ/2));
 430         }
 431 }
 432
 433 static void __ieee80211_roc_work(struct ieee80211_local *local)
 434 {
 435         struct ieee80211_roc_work *roc;
 436         bool on_channel;
 437
 438         lockdep_assert_held(&local->mtx);
 439
 440         if (WARN_ON(local->ops->remain_on_channel))
 441                 return;
 442
 443         roc = list_first_entry_or_null(&local->roc_list,
 444                                        struct ieee80211_roc_work, list);
 445         if (!roc)
 446                 return;
 447
 448         if (!roc->started) {
 449                 WARN_ON(local->use_chanctx);
 450                 _ieee80211_start_next_roc(local);
 451         } else {
 452                 on_channel = roc->on_channel;
 453                 if (ieee80211_recalc_sw_work(local, jiffies))
 454                         return;
 455
 456                 /* careful - roc pointer became invalid during recalc */
 457
 458                 if (!on_channel) {
 459                         ieee80211_flush_queues(local, NULL, false);
 460
 461                         local->tmp_channel = NULL;
 462                         ieee80211_hw_config(local, 0);
 463
 464                         ieee80211_offchannel_return(local);
 465                 }
 466
 467                 ieee80211_recalc_idle(local);
 468                 ieee80211_start_next_roc(local);
 469         }
 470 }
 471
 472 static void ieee80211_roc_work(struct work_struct *work)
 473 {
 474         struct ieee80211_local *local =
 475                 container_of(work, struct ieee80211_local, roc_work.work);
 476
 477         mutex_lock(&local->mtx);
 478         __ieee80211_roc_work(local);
 479         mutex_unlock(&local->mtx);
 480 }
 481
 482 static void ieee80211_hw_roc_done(struct work_struct *work)
 483 {
 484         struct ieee80211_local *local =
 485                 container_of(work, struct ieee80211_local, hw_roc_done);
 486
 487         mutex_lock(&local->mtx);
 488
 489         ieee80211_end_finished_rocs(local, jiffies);
 490
 491         /* if there's another roc, start it now */
 492         ieee80211_start_next_roc(local);
 493
 494         mutex_unlock(&local->mtx);
 495 }
 496
 497 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
 498 {
 499         struct ieee80211_local *local = hw_to_local(hw);
 500
 501         trace_api_remain_on_channel_expired(local);
 502
 503         ieee80211_queue_work(hw, &local->hw_roc_done);
 504 }
 505 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
 506
 507 static bool
 508 ieee80211_coalesce_hw_started_roc(struct ieee80211_local *local,
 509                                   struct ieee80211_roc_work *new_roc,
 510                                   struct ieee80211_roc_work *cur_roc)
 511 {
 512         unsigned long now = jiffies;
 513         unsigned long remaining;
 514
 515         if (WARN_ON(!cur_roc->started))
 516                 return false;
 517
 518         /* if it was scheduled in the hardware, but not started yet,
 519          * we can only combine if the older one had a longer duration
 520          */
 521         if (!cur_roc->hw_begun && new_roc->duration > cur_roc->duration)
 522                 return false;
 523
 524         remaining = cur_roc->start_time +
 525                     msecs_to_jiffies(cur_roc->duration) -
 526                     now;
 527
 528         /* if it doesn't fit entirely, schedule a new one */
 529         if (new_roc->duration > jiffies_to_msecs(remaining))
 530                 return false;
 531
 532         /* add just after the current one so we combine their finish later */
 533         list_add(&new_roc->list, &cur_roc->list);
 534
 535         /* if the existing one has already begun then let this one also
 536          * begin, otherwise they'll both be marked properly by the work
 537          * struct that runs once the driver notifies us of the beginning
 538          */
 539         if (cur_roc->hw_begun) {
 540                 new_roc->hw_begun = true;
 541                 ieee80211_handle_roc_started(new_roc, now);
 542         }
 543
 544         return true;
 545 }
 546
 547 static int ieee80211_start_roc_work(struct ieee80211_local *local,
 548                                     struct ieee80211_sub_if_data *sdata,
 549                                     struct ieee80211_channel *channel,
 550                                     unsigned int duration, u64 *cookie,
 551                                     struct sk_buff *txskb,
 552                                     enum ieee80211_roc_type type)
 553 {
 554         struct ieee80211_roc_work *roc, *tmp;
 555         bool queued = false, combine_started = true;
 556         int ret;
 557
 558         lockdep_assert_held(&local->mtx);
 559
 560         if (channel->freq_offset)
 561                 /* this may work, but is untested */
 562                 return -EOPNOTSUPP;
 563
 564         if (local->use_chanctx && !local->ops->remain_on_channel)
 565                 return -EOPNOTSUPP;
 566
 567         roc = kzalloc(sizeof(*roc), GFP_KERNEL);
 568         if (!roc)
 569                 return -ENOMEM;
 570
 571         /*
 572          * If the duration is zero, then the driver
 573          * wouldn't actually do anything. Set it to
 574          * 10 for now.
 575          *
 576          * TODO: cancel the off-channel operation
 577          *       when we get the SKB's TX status and
 578          *       the wait time was zero before.
 579          */
 580         if (!duration)
 581                 duration = 10;
 582
 583         roc->chan = channel;
 584         roc->duration = duration;
 585         roc->req_duration = duration;
 586         roc->frame = txskb;
 587         roc->type = type;
 588         roc->sdata = sdata;
 589
 590         /*
 591          * cookie is either the roc cookie (for normal roc)
 592          * or the SKB (for mgmt TX)
 593          */
 594         if (!txskb) {
 595                 roc->cookie = ieee80211_mgmt_tx_cookie(local);
 596                 *cookie = roc->cookie;
 597         } else {
 598                 roc->mgmt_tx_cookie = *cookie;
 599         }
 600
 601         /* if there's no need to queue, handle it immediately */
 602         if (list_empty(&local->roc_list) &&
 603             !local->scanning && !ieee80211_is_radar_required(local)) {
 604                 /* if not HW assist, just queue & schedule work */
 605                 if (!local->ops->remain_on_channel) {
 606                         list_add_tail(&roc->list, &local->roc_list);
 607                         ieee80211_queue_delayed_work(&local->hw,
 608                                                      &local->roc_work, 0);
 609                 } else {
 610                         /* otherwise actually kick it off here
 611                          * (for error handling)
 612                          */
 613                         ret = drv_remain_on_channel(local, sdata, channel,
 614                                                     duration, type);
 615                         if (ret) {
 616                                 kfree(roc);
 617                                 return ret;
 618                         }
 619                         roc->started = true;
 620                         list_add_tail(&roc->list, &local->roc_list);
 621                 }
 622
 623                 return 0;
 624         }
 625
 626         /* otherwise handle queueing */
 627
 628         list_for_each_entry(tmp, &local->roc_list, list) {
 629                 if (tmp->chan != channel || tmp->sdata != sdata)
 630                         continue;
 631
 632                 /*
 633                  * Extend this ROC if possible: If it hasn't started, add
 634                  * just after the new one to combine.
 635                  */
 636                 if (!tmp->started) {
 637                         list_add(&roc->list, &tmp->list);
 638                         queued = true;
 639                         break;
 640                 }
 641
 642                 if (!combine_started)
 643                         continue;
 644
 645                 if (!local->ops->remain_on_channel) {
 646                         /* If there's no hardware remain-on-channel, and
 647                          * doing so won't push us over the maximum r-o-c
 648                          * we allow, then we can just add the new one to
 649                          * the list and mark it as having started now.
 650                          * If it would push over the limit, don't try to
 651                          * combine with other started ones (that haven't
 652                          * been running as long) but potentially sort it
 653                          * with others that had the same fate.
 654                          */
 655                         unsigned long now = jiffies;
 656                         u32 elapsed = jiffies_to_msecs(now - tmp->start_time);
 657                         struct wiphy *wiphy = local->hw.wiphy;
 658                         u32 max_roc = wiphy->max_remain_on_channel_duration;
 659
 660                         if (elapsed + roc->duration > max_roc) {
 661                                 combine_started = false;
 662                                 continue;
 663                         }
 664
 665                         list_add(&roc->list, &tmp->list);
 666                         queued = true;
 667                         roc->on_channel = tmp->on_channel;
 668                         ieee80211_handle_roc_started(roc, now);
 669                         ieee80211_recalc_sw_work(local, now);
 670                         break;
 671                 }
 672
 673                 queued = ieee80211_coalesce_hw_started_roc(local, roc, tmp);
 674                 if (queued)
 675                         break;
 676                 /* if it wasn't queued, perhaps it can be combined with
 677                  * another that also couldn't get combined previously,
 678                  * but no need to check for already started ones, since
 679                  * that can't work.
 680                  */
 681                 combine_started = false;
 682         }
 683
 684         if (!queued)
 685                 list_add_tail(&roc->list, &local->roc_list);
 686
 687         return 0;
 688 }
 689
 690 int ieee80211_remain_on_channel(struct wiphy *wiphy, struct wireless_dev *wdev,
 691                                 struct ieee80211_channel *chan,
 692                                 unsigned int duration, u64 *cookie)
 693 {
 694         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 695         struct ieee80211_local *local = sdata->local;
 696         int ret;
 697
 698         mutex_lock(&local->mtx);
 699         ret = ieee80211_start_roc_work(local, sdata, chan,
 700                                        duration, cookie, NULL,
 701                                        IEEE80211_ROC_TYPE_NORMAL);
 702         mutex_unlock(&local->mtx);
 703
 704         return ret;
 705 }
 706
 707 static int ieee80211_cancel_roc(struct ieee80211_local *local,
 708                                 u64 cookie, bool mgmt_tx)
 709 {
 710         struct ieee80211_roc_work *roc, *tmp, *found = NULL;
 711         int ret;
 712
 713         if (!cookie)
 714                 return -ENOENT;
 715
 716         flush_work(&local->hw_roc_start);
 717
 718         mutex_lock(&local->mtx);
 719         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 720                 if (!mgmt_tx && roc->cookie != cookie)
 721                         continue;
 722                 else if (mgmt_tx && roc->mgmt_tx_cookie != cookie)
 723                         continue;
 724
 725                 found = roc;
 726                 break;
 727         }
 728
 729         if (!found) {
 730                 mutex_unlock(&local->mtx);
 731                 return -ENOENT;
 732         }
 733
 734         if (!found->started) {
 735                 ieee80211_roc_notify_destroy(found);
 736                 goto out_unlock;
 737         }
 738
 739         if (local->ops->remain_on_channel) {
 740                 ret = drv_cancel_remain_on_channel(local, roc->sdata);
 741                 if (WARN_ON_ONCE(ret)) {
 742                         mutex_unlock(&local->mtx);
 743                         return ret;
 744                 }
 745
 746                 /* TODO:
 747                  * if multiple items were combined here then we really shouldn't
 748                  * cancel them all - we should wait for as much time as needed
 749                  * for the longest remaining one, and only then cancel ...
 750                  */
 751                 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 752                         if (!roc->started)
 753                                 break;
 754                         if (roc == found)
 755                                 found = NULL;
 756                         ieee80211_roc_notify_destroy(roc);
 757                 }
 758
 759                 /* that really must not happen - it was started */
 760                 WARN_ON(found);
 761
 762                 ieee80211_start_next_roc(local);
 763         } else {
 764                 /* go through work struct to return to the operating channel */
 765                 found->abort = true;
 766                 mod_delayed_work(local->workqueue, &local->roc_work, 0);
 767         }
 768
 769  out_unlock:
 770         mutex_unlock(&local->mtx);
 771
 772         return 0;
 773 }
 774
 775 int ieee80211_cancel_remain_on_channel(struct wiphy *wiphy,
 776                                        struct wireless_dev *wdev, u64 cookie)
 777 {
 778         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 779         struct ieee80211_local *local = sdata->local;
 780
 781         return ieee80211_cancel_roc(local, cookie, false);
 782 }
 783
 784 int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev,
 785                       struct cfg80211_mgmt_tx_params *params, u64 *cookie)
 786 {
 787         struct ieee80211_sub_if_data *sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 788         struct ieee80211_local *local = sdata->local;
 789         struct sk_buff *skb;
 790         struct sta_info *sta;
 791         const struct ieee80211_mgmt *mgmt = (void *)params->buf;
 792         bool need_offchan = false;
 793         u32 flags;
 794         int ret;
 795         u8 *data;
 796
 797         if (params->dont_wait_for_ack)
 798                 flags = IEEE80211_TX_CTL_NO_ACK;
 799         else
 800                 flags = IEEE80211_TX_INTFL_NL80211_FRAME_TX |
 801                         IEEE80211_TX_CTL_REQ_TX_STATUS;
 802
 803         if (params->no_cck)
 804                 flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 805
 806         switch (sdata->vif.type) {
 807         case NL80211_IFTYPE_ADHOC:
 808                 if (!sdata->vif.bss_conf.ibss_joined)
 809                         need_offchan = true;
 810 #ifdef CONFIG_MAC80211_MESH
 811                 fallthrough;
 812         case NL80211_IFTYPE_MESH_POINT:
 813                 if (ieee80211_vif_is_mesh(&sdata->vif) &&
 814                     !sdata->u.mesh.mesh_id_len)
 815                         need_offchan = true;
 816 #endif
 817                 fallthrough;
 818         case NL80211_IFTYPE_AP:
 819         case NL80211_IFTYPE_AP_VLAN:
 820         case NL80211_IFTYPE_P2P_GO:
 821                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 822                     !ieee80211_vif_is_mesh(&sdata->vif) &&
 823                     !rcu_access_pointer(sdata->bss->beacon))
 824                         need_offchan = true;
 825                 if (!ieee80211_is_action(mgmt->frame_control) ||
 826                     mgmt->u.action.category == WLAN_CATEGORY_PUBLIC ||
 827                     mgmt->u.action.category == WLAN_CATEGORY_SELF_PROTECTED ||
 828                     mgmt->u.action.category == WLAN_CATEGORY_SPECTRUM_MGMT)
 829                         break;
 830                 rcu_read_lock();
 831                 sta = sta_info_get_bss(sdata, mgmt->da);
 832                 rcu_read_unlock();
 833                 if (!sta)
 834                         return -ENOLINK;
 835                 break;
 836         case NL80211_IFTYPE_STATION:
 837         case NL80211_IFTYPE_P2P_CLIENT:
 838                 sdata_lock(sdata);
 839                 if (!sdata->u.mgd.associated ||
 840                     (params->offchan && params->wait &&
 841                      local->ops->remain_on_channel &&
 842                      memcmp(sdata->u.mgd.associated->bssid,
 843                             mgmt->bssid, ETH_ALEN)))
 844                         need_offchan = true;
 845                 sdata_unlock(sdata);
 846                 break;
 847         case NL80211_IFTYPE_P2P_DEVICE:
 848                 need_offchan = true;
 849                 break;
 850         case NL80211_IFTYPE_NAN:
 851         default:
 852                 return -EOPNOTSUPP;
 853         }
 854
 855         /* configurations requiring offchan cannot work if no channel has been
 856          * specified
 857          */
 858         if (need_offchan && !params->chan)
 859                 return -EINVAL;
 860
 861         mutex_lock(&local->mtx);
 862
 863         /* Check if the operating channel is the requested channel */
 864         if (!need_offchan) {
 865                 struct ieee80211_chanctx_conf *chanctx_conf;
 866
 867                 rcu_read_lock();
 868                 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 869
 870                 if (chanctx_conf) {
 871                         need_offchan = params->chan &&
 872                                        (params->chan !=
 873                                         chanctx_conf->def.chan);
 874                 } else if (!params->chan) {
 875                         ret = -EINVAL;
 876                         rcu_read_unlock();
 877                         goto out_unlock;
 878                 } else {
 879                         need_offchan = true;
 880                 }
 881                 rcu_read_unlock();
 882         }
 883
 884         if (need_offchan && !params->offchan) {
 885                 ret = -EBUSY;
 886                 goto out_unlock;
 887         }
 888
 889         skb = dev_alloc_skb(local->hw.extra_tx_headroom + params->len);
 890         if (!skb) {
 891                 ret = -ENOMEM;
 892                 goto out_unlock;
 893         }
 894         skb_reserve(skb, local->hw.extra_tx_headroom);
 895
 896         data = skb_put_data(skb, params->buf, params->len);
 897
 898         /* Update CSA counters */
 899         if (sdata->vif.csa_active &&
 900             (sdata->vif.type == NL80211_IFTYPE_AP ||
 901              sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
 902              sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
 903             params->n_csa_offsets) {
 904                 int i;
 905                 struct beacon_data *beacon = NULL;
 906
 907                 rcu_read_lock();
 908
 909                 if (sdata->vif.type == NL80211_IFTYPE_AP)
 910                         beacon = rcu_dereference(sdata->u.ap.beacon);
 911                 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 912                         beacon = rcu_dereference(sdata->u.ibss.presp);
 913                 else if (ieee80211_vif_is_mesh(&sdata->vif))
 914                         beacon = rcu_dereference(sdata->u.mesh.beacon);
 915
 916                 if (beacon)
 917                         for (i = 0; i < params->n_csa_offsets; i++)
 918                                 data[params->csa_offsets[i]] =
 919                                         beacon->csa_current_counter;
 920
 921                 rcu_read_unlock();
 922         }
 923
 924         IEEE80211_SKB_CB(skb)->flags = flags;
 925
 926         skb->dev = sdata->dev;
 927
 928         if (!params->dont_wait_for_ack) {
 929                 /* make a copy to preserve the frame contents
 930                  * in case of encryption.
 931                  */
 932                 ret = ieee80211_attach_ack_skb(local, skb, cookie, GFP_KERNEL);
 933                 if (ret) {
 934                         kfree_skb(skb);
 935                         goto out_unlock;
 936                 }
 937         } else {
 938                 /* Assign a dummy non-zero cookie, it's not sent to
 939                  * userspace in this case but we rely on its value
 940                  * internally in the need_offchan case to distinguish
 941                  * mgmt-tx from remain-on-channel.
 942                  */
 943                 *cookie = 0xffffffff;
 944         }
 945
 946         if (!need_offchan) {
 947                 ieee80211_tx_skb(sdata, skb);
 948                 ret = 0;
 949                 goto out_unlock;
 950         }
 951
 952         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN |
 953                                         IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 954         if (ieee80211_hw_check(&local->hw, QUEUE_CONTROL))
 955                 IEEE80211_SKB_CB(skb)->hw_queue =
 956                         local->hw.offchannel_tx_hw_queue;
 957
 958         /* This will handle all kinds of coalescing and immediate TX */
 959         ret = ieee80211_start_roc_work(local, sdata, params->chan,
 960                                        params->wait, cookie, skb,
 961                                        IEEE80211_ROC_TYPE_MGMT_TX);
 962         if (ret)
 963                 ieee80211_free_txskb(&local->hw, skb);
 964  out_unlock:
 965         mutex_unlock(&local->mtx);
 966         return ret;
 967 }
 968
 969 int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
 970                                   struct wireless_dev *wdev, u64 cookie)
 971 {
 972         struct ieee80211_local *local = wiphy_priv(wiphy);
 973
 974         return ieee80211_cancel_roc(local, cookie, true);
 975 }
 976
 977 void ieee80211_roc_setup(struct ieee80211_local *local)
 978 {
 979         INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
 980         INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
 981         INIT_DELAYED_WORK(&local->roc_work, ieee80211_roc_work);
 982         INIT_LIST_HEAD(&local->roc_list);
 983 }
 984
 985 void ieee80211_roc_purge(struct ieee80211_local *local,
 986                          struct ieee80211_sub_if_data *sdata)
 987 {
 988         struct ieee80211_roc_work *roc, *tmp;
 989         bool work_to_do = false;
 990
 991         mutex_lock(&local->mtx);
 992         list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
 993                 if (sdata && roc->sdata != sdata)
 994                         continue;
 995
 996                 if (roc->started) {
 997                         if (local->ops->remain_on_channel) {
 998                                 /* can race, so ignore return value */
 999                                 drv_cancel_remain_on_channel(local, sdata);
1000                                 ieee80211_roc_notify_destroy(roc);
1001                         } else {
1002                                 roc->abort = true;
1003                                 work_to_do = true;
1004                         }
1005                 } else {
1006                         ieee80211_roc_notify_destroy(roc);
1007                 }
1008         }
1009         if (work_to_do)
1010                 __ieee80211_roc_work(local);
1011         mutex_unlock(&local->mtx);
1012 }