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         mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
 156                 pm, sta->sta.addr);
 157
 158         sta->local_pm = pm;
 159
 160         /*
 161          * announce peer-specific power mode transition
 162          * (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
 163          */
 164         if (sta->plink_state == NL80211_PLINK_ESTAB)
 165                 mps_qos_null_tx(sta);
 166
 167         return ieee80211_mps_local_status_update(sdata);
 168 }
 169
 170 /**
 171  * ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
 172  *
 173  * @sdata: local mesh subif
 174  * @sta: mesh STA
 175  * @hdr: 802.11 frame header
 176  *
 177  * see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
 178  *
 179  * NOTE: sta must be given when an individually-addressed QoS frame header
 180  * is handled, for group-addressed and management frames it is not used
 181  */
 182 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
 183                                    struct sta_info *sta,
 184                                    struct ieee80211_hdr *hdr)
 185 {
 186         enum nl80211_mesh_power_mode pm;
 187         u8 *qc;
 188
 189         if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
 190                     ieee80211_is_data_qos(hdr->frame_control) &&
 191                     !sta))
 192                 return;
 193
 194         if (is_unicast_ether_addr(hdr->addr1) &&
 195             ieee80211_is_data_qos(hdr->frame_control) &&
 196             sta->plink_state == NL80211_PLINK_ESTAB)
 197                 pm = sta->local_pm;
 198         else
 199                 pm = sdata->u.mesh.nonpeer_pm;
 200
 201         if (pm == NL80211_MESH_POWER_ACTIVE)
 202                 hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
 203         else
 204                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
 205
 206         if (!ieee80211_is_data_qos(hdr->frame_control))
 207                 return;
 208
 209         qc = ieee80211_get_qos_ctl(hdr);
 210
 211         if ((is_unicast_ether_addr(hdr->addr1) &&
 212              pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
 213             (is_multicast_ether_addr(hdr->addr1) &&
 214              sdata->u.mesh.ps_peers_deep_sleep > 0))
 215                 qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 216         else
 217                 qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 218 }
 219
 220 /**
 221  * ieee80211_mps_sta_status_update - update buffering status of neighbor STA
 222  *
 223  * @sta: mesh STA
 224  *
 225  * called after change of peering status or non-peer/peer-specific power mode
 226  */
 227 void ieee80211_mps_sta_status_update(struct sta_info *sta)
 228 {
 229         enum nl80211_mesh_power_mode pm;
 230         bool do_buffer;
 231
 232         /*
 233          * use peer-specific power mode if peering is established and the
 234          * peer's power mode is known
 235          */
 236         if (sta->plink_state == NL80211_PLINK_ESTAB &&
 237             sta->peer_pm != NL80211_MESH_POWER_UNKNOWN)
 238                 pm = sta->peer_pm;
 239         else
 240                 pm = sta->nonpeer_pm;
 241
 242         do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
 243
 244         /* Don't let the same PS state be set twice */
 245         if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
 246                 return;
 247
 248         if (do_buffer) {
 249                 set_sta_flag(sta, WLAN_STA_PS_STA);
 250                 atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
 251                 mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
 252                         sta->sta.addr);
 253         } else {
 254                 ieee80211_sta_ps_deliver_wakeup(sta);
 255         }
 256
 257         /* clear the MPSP flags for non-peers or active STA */
 258         if (sta->plink_state != NL80211_PLINK_ESTAB) {
 259                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 260                 clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 261         } else if (!do_buffer) {
 262                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 263         }
 264 }
 265
 266 static void mps_set_sta_peer_pm(struct sta_info *sta,
 267                                 struct ieee80211_hdr *hdr)
 268 {
 269         enum nl80211_mesh_power_mode pm;
 270         u8 *qc = ieee80211_get_qos_ctl(hdr);
 271
 272         /*
 273          * Test Power Management field of frame control (PW) and
 274          * mesh power save level subfield of QoS control field (PSL)
 275          *
 276          * | PM | PSL| Mesh PM |
 277          * +----+----+---------+
 278          * | 0  |Rsrv|  Active |
 279          * | 1  | 0  |  Light  |
 280          * | 1  | 1  |  Deep   |
 281          */
 282         if (ieee80211_has_pm(hdr->frame_control)) {
 283                 if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
 284                         pm = NL80211_MESH_POWER_DEEP_SLEEP;
 285                 else
 286                         pm = NL80211_MESH_POWER_LIGHT_SLEEP;
 287         } else {
 288                 pm = NL80211_MESH_POWER_ACTIVE;
 289         }
 290
 291         if (sta->peer_pm == pm)
 292                 return;
 293
 294         mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
 295                 sta->sta.addr, pm);
 296
 297         sta->peer_pm = pm;
 298
 299         ieee80211_mps_sta_status_update(sta);
 300 }
 301
 302 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
 303                                    struct ieee80211_hdr *hdr)
 304 {
 305         enum nl80211_mesh_power_mode pm;
 306
 307         if (ieee80211_has_pm(hdr->frame_control))
 308                 pm = NL80211_MESH_POWER_DEEP_SLEEP;
 309         else
 310                 pm = NL80211_MESH_POWER_ACTIVE;
 311
 312         if (sta->nonpeer_pm == pm)
 313                 return;
 314
 315         mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
 316                 sta->sta.addr, pm);
 317
 318         sta->nonpeer_pm = pm;
 319
 320         ieee80211_mps_sta_status_update(sta);
 321 }
 322
 323 /**
 324  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
 325  *
 326  * @sta: STA info that transmitted the frame
 327  * @hdr: IEEE 802.11 (QoS) Header
 328  */
 329 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 330                                     struct ieee80211_hdr *hdr)
 331 {
 332         if (is_unicast_ether_addr(hdr->addr1) &&
 333             ieee80211_is_data_qos(hdr->frame_control)) {
 334                 /*
 335                  * individually addressed QoS Data/Null frames contain
 336                  * peer link-specific PS mode towards the local STA
 337                  */
 338                 mps_set_sta_peer_pm(sta, hdr);
 339
 340                 /* check for mesh Peer Service Period trigger frames */
 341                 ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
 342                                                sta, false, false);
 343         } else {
 344                 /*
 345                  * can only determine non-peer PS mode
 346                  * (see IEEE802.11-2012 8.2.4.1.7)
 347                  */
 348                 mps_set_sta_nonpeer_pm(sta, hdr);
 349         }
 350 }
 351
 352
 353 /* mesh PS frame release */
 354
 355 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
 356 {
 357         struct ieee80211_sub_if_data *sdata = sta->sdata;
 358         struct sk_buff *skb;
 359         struct ieee80211_hdr *nullfunc;
 360         struct ieee80211_tx_info *info;
 361         u8 *qc;
 362
 363         skb = mps_qos_null_get(sta);
 364         if (!skb)
 365                 return;
 366
 367         nullfunc = (struct ieee80211_hdr *) skb->data;
 368         if (!eosp)
 369                 nullfunc->frame_control |=
 370                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 371         /*
 372          * | RSPI | EOSP |  MPSP triggering   |
 373          * +------+------+--------------------+
 374          * |  0   |  0   | local STA is owner |
 375          * |  0   |  1   | no MPSP (MPSP end) |
 376          * |  1   |  0   | both STA are owner |
 377          * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
 378          */
 379         qc = ieee80211_get_qos_ctl(nullfunc);
 380         if (rspi)
 381                 qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
 382         if (eosp)
 383                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
 384
 385         info = IEEE80211_SKB_CB(skb);
 386
 387         info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
 388                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 389
 390         mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
 391                 rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
 392
 393         ieee80211_tx_skb(sdata, skb);
 394 }
 395
 396 /**
 397  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
 398  *
 399  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
 400  * flag in the QoS Control field. In case the current tailing frame is not a
 401  * QoS Data frame, append a QoS Null to carry the flag.
 402  */
 403 static void mpsp_qos_null_append(struct sta_info *sta,
 404                                  struct sk_buff_head *frames)
 405 {
 406         struct ieee80211_sub_if_data *sdata = sta->sdata;
 407         struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
 408         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 409         struct ieee80211_tx_info *info;
 410
 411         if (ieee80211_is_data_qos(hdr->frame_control))
 412                 return;
 413
 414         new_skb = mps_qos_null_get(sta);
 415         if (!new_skb)
 416                 return;
 417
 418         mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
 419                 sta->sta.addr);
 420         /*
 421          * This frame has to be transmitted last. Assign lowest priority to
 422          * make sure it cannot pass other frames when releasing multiple ACs.
 423          */
 424         new_skb->priority = 1;
 425         skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
 426         ieee80211_set_qos_hdr(sdata, new_skb);
 427
 428         info = IEEE80211_SKB_CB(new_skb);
 429         info->control.vif = &sdata->vif;
 430         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 431
 432         __skb_queue_tail(frames, new_skb);
 433 }
 434
 435 /**
 436  * mps_frame_deliver - transmit frames during mesh powersave
 437  *
 438  * @sta: STA info to transmit to
 439  * @n_frames: number of frames to transmit. -1 for all
 440  */
 441 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
 442 {
 443         struct ieee80211_sub_if_data *sdata = sta->sdata;
 444         struct ieee80211_local *local = sdata->local;
 445         int ac;
 446         struct sk_buff_head frames;
 447         struct sk_buff *skb;
 448         bool more_data = false;
 449
 450         skb_queue_head_init(&frames);
 451
 452         /* collect frame(s) from buffers */
 453         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
 454                 while (n_frames != 0) {
 455                         skb = skb_dequeue(&sta->tx_filtered[ac]);
 456                         if (!skb) {
 457                                 skb = skb_dequeue(
 458                                         &sta->ps_tx_buf[ac]);
 459                                 if (skb)
 460                                         local->total_ps_buffered--;
 461                         }
 462                         if (!skb)
 463                                 break;
 464                         n_frames--;
 465                         __skb_queue_tail(&frames, skb);
 466                 }
 467
 468                 if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
 469                     !skb_queue_empty(&sta->ps_tx_buf[ac]))
 470                         more_data = true;
 471         }
 472
 473         /* nothing to send? -> EOSP */
 474         if (skb_queue_empty(&frames)) {
 475                 mpsp_trigger_send(sta, false, true);
 476                 return;
 477         }
 478
 479         /* in a MPSP make sure the last skb is a QoS Data frame */
 480         if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 481                 mpsp_qos_null_append(sta, &frames);
 482
 483         mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
 484                 skb_queue_len(&frames), sta->sta.addr);
 485
 486         /* prepare collected frames for transmission */
 487         skb_queue_walk(&frames, skb) {
 488                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 489                 struct ieee80211_hdr *hdr = (void *) skb->data;
 490
 491                 /*
 492                  * Tell TX path to send this frame even though the
 493                  * STA may still remain is PS mode after this frame
 494                  * exchange.
 495                  */
 496                 info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
 497
 498                 if (more_data || !skb_queue_is_last(&frames, skb))
 499                         hdr->frame_control |=
 500                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 501                 else
 502                         hdr->frame_control &=
 503                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 504
 505                 if (skb_queue_is_last(&frames, skb) &&
 506                     ieee80211_is_data_qos(hdr->frame_control)) {
 507                         u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
 508
 509                         /* MPSP trigger frame ends service period */
 510                         *qoshdr |= IEEE80211_QOS_CTL_EOSP;
 511                         info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 512                 }
 513         }
 514
 515         ieee80211_add_pending_skbs(local, &frames);
 516         sta_info_recalc_tim(sta);
 517 }
 518
 519 /**
 520  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
 521  *
 522  * @qc: QoS Control field
 523  * @sta: peer to start a MPSP with
 524  * @tx: frame was transmitted by the local STA
 525  * @acked: frame has been transmitted successfully
 526  *
 527  * NOTE: active mode STA may only serve as MPSP owner
 528  */
 529 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 530                                     bool tx, bool acked)
 531 {
 532         u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
 533         u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
 534
 535         if (tx) {
 536                 if (rspi && acked)
 537                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 538
 539                 if (eosp)
 540                         clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 541                 else if (acked &&
 542                          test_sta_flag(sta, WLAN_STA_PS_STA) &&
 543                          !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 544                         mps_frame_deliver(sta, -1);
 545         } else {
 546                 if (eosp)
 547                         clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 548                 else if (sta->local_pm != NL80211_MESH_POWER_ACTIVE)
 549                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 550
 551                 if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 552                         mps_frame_deliver(sta, -1);
 553         }
 554 }
 555
 556 /**
 557  * ieee80211_mps_frame_release - release buffered frames in response to beacon
 558  *
 559  * @sta: mesh STA
 560  * @elems: beacon IEs
 561  *
 562  * For peers if we have individually-addressed frames buffered or the peer
 563  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
 564  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
 565  * trigger frames. If the neighbour STA is not a peer, only send single frames.
 566  */
 567 void ieee80211_mps_frame_release(struct sta_info *sta,
 568                                  struct ieee802_11_elems *elems)
 569 {
 570         int ac, buffer_local = 0;
 571         bool has_buffered = false;
 572
 573         /* TIM map only for LLID <= IEEE80211_MAX_AID */
 574         if (sta->plink_state == NL80211_PLINK_ESTAB)
 575                 has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
 576                                 le16_to_cpu(sta->llid) % IEEE80211_MAX_AID);
 577
 578         if (has_buffered)
 579                 mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
 580                         sta->sta.addr);
 581
 582         /* only transmit to PS STA with announced, non-zero awake window */
 583         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 584             (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
 585                 return;
 586
 587         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
 588                 buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
 589                                 skb_queue_len(&sta->tx_filtered[ac]);
 590
 591         if (!has_buffered && !buffer_local)
 592                 return;
 593
 594         if (sta->plink_state == NL80211_PLINK_ESTAB)
 595                 mpsp_trigger_send(sta, has_buffered, !buffer_local);
 596         else
 597                 mps_frame_deliver(sta, 1);
 598 }