net/mac80211/mesh_ps.c

   1 /*
   2  * Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
   3  * Copyright 2012-2013, cozybit Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include "mesh.h"
  11 #include "wme.h"
  12
  13
  14 /* mesh PS management */
  15
  16 /**
  17  * mps_qos_null_get - create pre-addressed QoS Null frame for mesh powersave
  18  */
  19 static struct sk_buff *mps_qos_null_get(struct sta_info *sta)
  20 {
  21         struct ieee80211_sub_if_data *sdata = sta->sdata;
  22         struct ieee80211_local *local = sdata->local;
  23         struct ieee80211_hdr *nullfunc; /* use 4addr header */
  24         struct sk_buff *skb;
  25         int size = sizeof(*nullfunc);
  26         __le16 fc;
  27
  28         skb = dev_alloc_skb(local->hw.extra_tx_headroom + size + 2);
  29         if (!skb)
  30                 return NULL;
  31         skb_reserve(skb, local->hw.extra_tx_headroom);
  32
  33         nullfunc = (struct ieee80211_hdr *) skb_put(skb, size);
  34         fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_NULLFUNC);
  35         ieee80211_fill_mesh_addresses(nullfunc, &fc, sta->sta.addr,
  36                                       sdata->vif.addr);
  37         nullfunc->frame_control = fc;
  38         nullfunc->duration_id = 0;
  39         /* no address resolution for this frame -> set addr 1 immediately */
  40         memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
  41         memset(skb_put(skb, 2), 0, 2); /* append QoS control field */
  42         ieee80211_mps_set_frame_flags(sdata, sta, nullfunc);
  43
  44         return skb;
  45 }
  46
  47 /**
  48  * mps_qos_null_tx - send a QoS Null to indicate link-specific power mode
  49  */
  50 static void mps_qos_null_tx(struct sta_info *sta)
  51 {
  52         struct sk_buff *skb;
  53
  54         skb = mps_qos_null_get(sta);
  55         if (!skb)
  56                 return;
  57
  58         mps_dbg(sta->sdata, "announcing peer-specific power mode to %pM\n",
  59                 sta->sta.addr);
  60
  61         /* don't unintentionally start a MPSP */
  62         if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
  63                 u8 *qc = ieee80211_get_qos_ctl((void *) skb->data);
  64
  65                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
  66         }
  67
  68         ieee80211_tx_skb(sta->sdata, skb);
  69 }
  70
  71 /**
  72  * ieee80211_mps_local_status_update - track status of local link-specific PMs
  73  *
  74  * @sdata: local mesh subif
  75  *
  76  * sets the non-peer power mode and triggers the driver PS (re-)configuration
  77  * Return BSS_CHANGED_BEACON if a beacon update is necessary.
  78  */
  79 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
  80 {
  81         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  82         struct sta_info *sta;
  83         bool peering = false;
  84         int light_sleep_cnt = 0;
  85         int deep_sleep_cnt = 0;
  86         u32 changed = 0;
  87         enum nl80211_mesh_power_mode nonpeer_pm;
  88
  89         rcu_read_lock();
  90         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  91                 if (sdata != sta->sdata)
  92                         continue;
  93
  94                 switch (sta->plink_state) {
  95                 case NL80211_PLINK_OPN_SNT:
  96                 case NL80211_PLINK_OPN_RCVD:
  97                 case NL80211_PLINK_CNF_RCVD:
  98                         peering = true;
  99                         break;
 100                 case NL80211_PLINK_ESTAB:
 101                         if (sta->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
 102                                 light_sleep_cnt++;
 103                         else if (sta->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
 104                                 deep_sleep_cnt++;
 105                         break;
 106                 default:
 107                         break;
 108                 }
 109         }
 110         rcu_read_unlock();
 111
 112         /*
 113          * Set non-peer mode to active during peering/scanning/authentication
 114          * (see IEEE802.11-2012 13.14.8.3). The non-peer mesh power mode is
 115          * deep sleep if the local STA is in light or deep sleep towards at
 116          * least one mesh peer (see 13.14.3.1). Otherwise, set it to the
 117          * user-configured default value.
 118          */
 119         if (peering) {
 120                 mps_dbg(sdata, "setting non-peer PM to active for peering\n");
 121                 nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
 122         } else if (light_sleep_cnt || deep_sleep_cnt) {
 123                 mps_dbg(sdata, "setting non-peer PM to deep sleep\n");
 124                 nonpeer_pm = NL80211_MESH_POWER_DEEP_SLEEP;
 125         } else {
 126                 mps_dbg(sdata, "setting non-peer PM to user value\n");
 127                 nonpeer_pm = ifmsh->mshcfg.power_mode;
 128         }
 129
 130         /* need update if sleep counts move between 0 and non-zero */
 131         if (ifmsh->nonpeer_pm != nonpeer_pm ||
 132             !ifmsh->ps_peers_light_sleep != !light_sleep_cnt ||
 133             !ifmsh->ps_peers_deep_sleep != !deep_sleep_cnt)
 134                 changed = BSS_CHANGED_BEACON;
 135
 136         ifmsh->nonpeer_pm = nonpeer_pm;
 137         ifmsh->ps_peers_light_sleep = light_sleep_cnt;
 138         ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;
 139
 140         return changed;
 141 }
 142
 143 /**
 144  * ieee80211_mps_set_sta_local_pm - set local PM towards a mesh STA
 145  *
 146  * @sta: mesh STA
 147  * @pm: the power mode to set
 148  * Return BSS_CHANGED_BEACON if a beacon update is in order.
 149  */
 150 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
 151                                    enum nl80211_mesh_power_mode pm)
 152 {
 153         struct ieee80211_sub_if_data *sdata = sta->sdata;
 154
 155         if (sta->local_pm == pm)
 156                 return 0;
 157
 158         mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
 159                 pm, sta->sta.addr);
 160
 161         sta->local_pm = pm;
 162
 163         /*
 164          * announce peer-specific power mode transition
 165          * (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
 166          */
 167         if (sta->plink_state == NL80211_PLINK_ESTAB)
 168                 mps_qos_null_tx(sta);
 169
 170         return ieee80211_mps_local_status_update(sdata);
 171 }
 172
 173 /**
 174  * ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
 175  *
 176  * @sdata: local mesh subif
 177  * @sta: mesh STA
 178  * @hdr: 802.11 frame header
 179  *
 180  * see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
 181  *
 182  * NOTE: sta must be given when an individually-addressed QoS frame header
 183  * is handled, for group-addressed and management frames it is not used
 184  */
 185 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
 186                                    struct sta_info *sta,
 187                                    struct ieee80211_hdr *hdr)
 188 {
 189         enum nl80211_mesh_power_mode pm;
 190         u8 *qc;
 191
 192         if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
 193                     ieee80211_is_data_qos(hdr->frame_control) &&
 194                     !sta))
 195                 return;
 196
 197         if (is_unicast_ether_addr(hdr->addr1) &&
 198             ieee80211_is_data_qos(hdr->frame_control) &&
 199             sta->plink_state == NL80211_PLINK_ESTAB)
 200                 pm = sta->local_pm;
 201         else
 202                 pm = sdata->u.mesh.nonpeer_pm;
 203
 204         if (pm == NL80211_MESH_POWER_ACTIVE)
 205                 hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
 206         else
 207                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
 208
 209         if (!ieee80211_is_data_qos(hdr->frame_control))
 210                 return;
 211
 212         qc = ieee80211_get_qos_ctl(hdr);
 213
 214         if ((is_unicast_ether_addr(hdr->addr1) &&
 215              pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
 216             (is_multicast_ether_addr(hdr->addr1) &&
 217              sdata->u.mesh.ps_peers_deep_sleep > 0))
 218                 qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 219         else
 220                 qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 221 }
 222
 223 /**
 224  * ieee80211_mps_sta_status_update - update buffering status of neighbor STA
 225  *
 226  * @sta: mesh STA
 227  *
 228  * called after change of peering status or non-peer/peer-specific power mode
 229  */
 230 void ieee80211_mps_sta_status_update(struct sta_info *sta)
 231 {
 232         enum nl80211_mesh_power_mode pm;
 233         bool do_buffer;
 234
 235         /* For non-assoc STA, prevent buffering or frame transmission */
 236         if (sta->sta_state < IEEE80211_STA_ASSOC)
 237                 return;
 238
 239         /*
 240          * use peer-specific power mode if peering is established and the
 241          * peer's power mode is known
 242          */
 243         if (sta->plink_state == NL80211_PLINK_ESTAB &&
 244             sta->peer_pm != NL80211_MESH_POWER_UNKNOWN)
 245                 pm = sta->peer_pm;
 246         else
 247                 pm = sta->nonpeer_pm;
 248
 249         do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
 250
 251         /* clear the MPSP flags for non-peers or active STA */
 252         if (sta->plink_state != NL80211_PLINK_ESTAB) {
 253                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 254                 clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 255         } else if (!do_buffer) {
 256                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 257         }
 258
 259         /* Don't let the same PS state be set twice */
 260         if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
 261                 return;
 262
 263         if (do_buffer) {
 264                 set_sta_flag(sta, WLAN_STA_PS_STA);
 265                 atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
 266                 mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
 267                         sta->sta.addr);
 268         } else {
 269                 ieee80211_sta_ps_deliver_wakeup(sta);
 270         }
 271 }
 272
 273 static void mps_set_sta_peer_pm(struct sta_info *sta,
 274                                 struct ieee80211_hdr *hdr)
 275 {
 276         enum nl80211_mesh_power_mode pm;
 277         u8 *qc = ieee80211_get_qos_ctl(hdr);
 278
 279         /*
 280          * Test Power Management field of frame control (PW) and
 281          * mesh power save level subfield of QoS control field (PSL)
 282          *
 283          * | PM | PSL| Mesh PM |
 284          * +----+----+---------+
 285          * | 0  |Rsrv|  Active |
 286          * | 1  | 0  |  Light  |
 287          * | 1  | 1  |  Deep   |
 288          */
 289         if (ieee80211_has_pm(hdr->frame_control)) {
 290                 if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
 291                         pm = NL80211_MESH_POWER_DEEP_SLEEP;
 292                 else
 293                         pm = NL80211_MESH_POWER_LIGHT_SLEEP;
 294         } else {
 295                 pm = NL80211_MESH_POWER_ACTIVE;
 296         }
 297
 298         if (sta->peer_pm == pm)
 299                 return;
 300
 301         mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
 302                 sta->sta.addr, pm);
 303
 304         sta->peer_pm = pm;
 305
 306         ieee80211_mps_sta_status_update(sta);
 307 }
 308
 309 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
 310                                    struct ieee80211_hdr *hdr)
 311 {
 312         enum nl80211_mesh_power_mode pm;
 313
 314         if (ieee80211_has_pm(hdr->frame_control))
 315                 pm = NL80211_MESH_POWER_DEEP_SLEEP;
 316         else
 317                 pm = NL80211_MESH_POWER_ACTIVE;
 318
 319         if (sta->nonpeer_pm == pm)
 320                 return;
 321
 322         mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
 323                 sta->sta.addr, pm);
 324
 325         sta->nonpeer_pm = pm;
 326
 327         ieee80211_mps_sta_status_update(sta);
 328 }
 329
 330 /**
 331  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
 332  *
 333  * @sta: STA info that transmitted the frame
 334  * @hdr: IEEE 802.11 (QoS) Header
 335  */
 336 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 337                                     struct ieee80211_hdr *hdr)
 338 {
 339         if (is_unicast_ether_addr(hdr->addr1) &&
 340             ieee80211_is_data_qos(hdr->frame_control)) {
 341                 /*
 342                  * individually addressed QoS Data/Null frames contain
 343                  * peer link-specific PS mode towards the local STA
 344                  */
 345                 mps_set_sta_peer_pm(sta, hdr);
 346
 347                 /* check for mesh Peer Service Period trigger frames */
 348                 ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
 349                                                sta, false, false);
 350         } else {
 351                 /*
 352                  * can only determine non-peer PS mode
 353                  * (see IEEE802.11-2012 8.2.4.1.7)
 354                  */
 355                 mps_set_sta_nonpeer_pm(sta, hdr);
 356         }
 357 }
 358
 359
 360 /* mesh PS frame release */
 361
 362 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
 363 {
 364         struct ieee80211_sub_if_data *sdata = sta->sdata;
 365         struct sk_buff *skb;
 366         struct ieee80211_hdr *nullfunc;
 367         struct ieee80211_tx_info *info;
 368         u8 *qc;
 369
 370         skb = mps_qos_null_get(sta);
 371         if (!skb)
 372                 return;
 373
 374         nullfunc = (struct ieee80211_hdr *) skb->data;
 375         if (!eosp)
 376                 nullfunc->frame_control |=
 377                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 378         /*
 379          * | RSPI | EOSP |  MPSP triggering   |
 380          * +------+------+--------------------+
 381          * |  0   |  0   | local STA is owner |
 382          * |  0   |  1   | no MPSP (MPSP end) |
 383          * |  1   |  0   | both STA are owner |
 384          * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
 385          */
 386         qc = ieee80211_get_qos_ctl(nullfunc);
 387         if (rspi)
 388                 qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
 389         if (eosp)
 390                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
 391
 392         info = IEEE80211_SKB_CB(skb);
 393
 394         info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
 395                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 396
 397         mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
 398                 rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
 399
 400         ieee80211_tx_skb(sdata, skb);
 401 }
 402
 403 /**
 404  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
 405  *
 406  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
 407  * flag in the QoS Control field. In case the current tailing frame is not a
 408  * QoS Data frame, append a QoS Null to carry the flag.
 409  */
 410 static void mpsp_qos_null_append(struct sta_info *sta,
 411                                  struct sk_buff_head *frames)
 412 {
 413         struct ieee80211_sub_if_data *sdata = sta->sdata;
 414         struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
 415         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 416         struct ieee80211_tx_info *info;
 417
 418         if (ieee80211_is_data_qos(hdr->frame_control))
 419                 return;
 420
 421         new_skb = mps_qos_null_get(sta);
 422         if (!new_skb)
 423                 return;
 424
 425         mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
 426                 sta->sta.addr);
 427         /*
 428          * This frame has to be transmitted last. Assign lowest priority to
 429          * make sure it cannot pass other frames when releasing multiple ACs.
 430          */
 431         new_skb->priority = 1;
 432         skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
 433         ieee80211_set_qos_hdr(sdata, new_skb);
 434
 435         info = IEEE80211_SKB_CB(new_skb);
 436         info->control.vif = &sdata->vif;
 437         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 438
 439         __skb_queue_tail(frames, new_skb);
 440 }
 441
 442 /**
 443  * mps_frame_deliver - transmit frames during mesh powersave
 444  *
 445  * @sta: STA info to transmit to
 446  * @n_frames: number of frames to transmit. -1 for all
 447  */
 448 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
 449 {
 450         struct ieee80211_local *local = sta->sdata->local;
 451         int ac;
 452         struct sk_buff_head frames;
 453         struct sk_buff *skb;
 454         bool more_data = false;
 455
 456         skb_queue_head_init(&frames);
 457
 458         /* collect frame(s) from buffers */
 459         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
 460                 while (n_frames != 0) {
 461                         skb = skb_dequeue(&sta->tx_filtered[ac]);
 462                         if (!skb) {
 463                                 skb = skb_dequeue(
 464                                         &sta->ps_tx_buf[ac]);
 465                                 if (skb)
 466                                         local->total_ps_buffered--;
 467                         }
 468                         if (!skb)
 469                                 break;
 470                         n_frames--;
 471                         __skb_queue_tail(&frames, skb);
 472                 }
 473
 474                 if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
 475                     !skb_queue_empty(&sta->ps_tx_buf[ac]))
 476                         more_data = true;
 477         }
 478
 479         /* nothing to send? -> EOSP */
 480         if (skb_queue_empty(&frames)) {
 481                 mpsp_trigger_send(sta, false, true);
 482                 return;
 483         }
 484
 485         /* in a MPSP make sure the last skb is a QoS Data frame */
 486         if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 487                 mpsp_qos_null_append(sta, &frames);
 488
 489         mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
 490                 skb_queue_len(&frames), sta->sta.addr);
 491
 492         /* prepare collected frames for transmission */
 493         skb_queue_walk(&frames, skb) {
 494                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 495                 struct ieee80211_hdr *hdr = (void *) skb->data;
 496
 497                 /*
 498                  * Tell TX path to send this frame even though the
 499                  * STA may still remain is PS mode after this frame
 500                  * exchange.
 501                  */
 502                 info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
 503
 504                 if (more_data || !skb_queue_is_last(&frames, skb))
 505                         hdr->frame_control |=
 506                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 507                 else
 508                         hdr->frame_control &=
 509                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 510
 511                 if (skb_queue_is_last(&frames, skb) &&
 512                     ieee80211_is_data_qos(hdr->frame_control)) {
 513                         u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
 514
 515                         /* MPSP trigger frame ends service period */
 516                         *qoshdr |= IEEE80211_QOS_CTL_EOSP;
 517                         info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 518                 }
 519         }
 520
 521         ieee80211_add_pending_skbs(local, &frames);
 522         sta_info_recalc_tim(sta);
 523 }
 524
 525 /**
 526  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
 527  *
 528  * @qc: QoS Control field
 529  * @sta: peer to start a MPSP with
 530  * @tx: frame was transmitted by the local STA
 531  * @acked: frame has been transmitted successfully
 532  *
 533  * NOTE: active mode STA may only serve as MPSP owner
 534  */
 535 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 536                                     bool tx, bool acked)
 537 {
 538         u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
 539         u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
 540
 541         if (tx) {
 542                 if (rspi && acked)
 543                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 544
 545                 if (eosp)
 546                         clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 547                 else if (acked &&
 548                          test_sta_flag(sta, WLAN_STA_PS_STA) &&
 549                          !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 550                         mps_frame_deliver(sta, -1);
 551         } else {
 552                 if (eosp)
 553                         clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 554                 else if (sta->local_pm != NL80211_MESH_POWER_ACTIVE)
 555                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 556
 557                 if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 558                         mps_frame_deliver(sta, -1);
 559         }
 560 }
 561
 562 /**
 563  * ieee80211_mps_frame_release - release frames buffered due to mesh power save
 564  *
 565  * @sta: mesh STA
 566  * @elems: IEs of beacon or probe response
 567  *
 568  * For peers if we have individually-addressed frames buffered or the peer
 569  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
 570  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
 571  * trigger frames. If the neighbour STA is not a peer, only send single frames.
 572  */
 573 void ieee80211_mps_frame_release(struct sta_info *sta,
 574                                  struct ieee802_11_elems *elems)
 575 {
 576         int ac, buffer_local = 0;
 577         bool has_buffered = false;
 578
 579         if (sta->plink_state == NL80211_PLINK_ESTAB)
 580                 has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
 581                                                    sta->llid);
 582
 583         if (has_buffered)
 584                 mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
 585                         sta->sta.addr);
 586
 587         /* only transmit to PS STA with announced, non-zero awake window */
 588         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 589             (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
 590                 return;
 591
 592         if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 593                 for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
 594                         buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
 595                                         skb_queue_len(&sta->tx_filtered[ac]);
 596
 597         if (!has_buffered && !buffer_local)
 598                 return;
 599
 600         if (sta->plink_state == NL80211_PLINK_ESTAB)
 601                 mpsp_trigger_send(sta, has_buffered, !buffer_local);
 602         else
 603                 mps_frame_deliver(sta, 1);
 604 }