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         /* For non-assoc STA, prevent buffering or frame transmission */
 233         if (sta->sta_state < IEEE80211_STA_ASSOC)
 234                 return;
 235
 236         /*
 237          * use peer-specific power mode if peering is established and the
 238          * peer's power mode is known
 239          */
 240         if (sta->plink_state == NL80211_PLINK_ESTAB &&
 241             sta->peer_pm != NL80211_MESH_POWER_UNKNOWN)
 242                 pm = sta->peer_pm;
 243         else
 244                 pm = sta->nonpeer_pm;
 245
 246         do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
 247
 248         /* Don't let the same PS state be set twice */
 249         if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
 250                 return;
 251
 252         if (do_buffer) {
 253                 set_sta_flag(sta, WLAN_STA_PS_STA);
 254                 atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
 255                 mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
 256                         sta->sta.addr);
 257         } else {
 258                 ieee80211_sta_ps_deliver_wakeup(sta);
 259         }
 260
 261         /* clear the MPSP flags for non-peers or active STA */
 262         if (sta->plink_state != NL80211_PLINK_ESTAB) {
 263                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 264                 clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 265         } else if (!do_buffer) {
 266                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 267         }
 268 }
 269
 270 static void mps_set_sta_peer_pm(struct sta_info *sta,
 271                                 struct ieee80211_hdr *hdr)
 272 {
 273         enum nl80211_mesh_power_mode pm;
 274         u8 *qc = ieee80211_get_qos_ctl(hdr);
 275
 276         /*
 277          * Test Power Management field of frame control (PW) and
 278          * mesh power save level subfield of QoS control field (PSL)
 279          *
 280          * | PM | PSL| Mesh PM |
 281          * +----+----+---------+
 282          * | 0  |Rsrv|  Active |
 283          * | 1  | 0  |  Light  |
 284          * | 1  | 1  |  Deep   |
 285          */
 286         if (ieee80211_has_pm(hdr->frame_control)) {
 287                 if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
 288                         pm = NL80211_MESH_POWER_DEEP_SLEEP;
 289                 else
 290                         pm = NL80211_MESH_POWER_LIGHT_SLEEP;
 291         } else {
 292                 pm = NL80211_MESH_POWER_ACTIVE;
 293         }
 294
 295         if (sta->peer_pm == pm)
 296                 return;
 297
 298         mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
 299                 sta->sta.addr, pm);
 300
 301         sta->peer_pm = pm;
 302
 303         ieee80211_mps_sta_status_update(sta);
 304 }
 305
 306 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
 307                                    struct ieee80211_hdr *hdr)
 308 {
 309         enum nl80211_mesh_power_mode pm;
 310
 311         if (ieee80211_has_pm(hdr->frame_control))
 312                 pm = NL80211_MESH_POWER_DEEP_SLEEP;
 313         else
 314                 pm = NL80211_MESH_POWER_ACTIVE;
 315
 316         if (sta->nonpeer_pm == pm)
 317                 return;
 318
 319         mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
 320                 sta->sta.addr, pm);
 321
 322         sta->nonpeer_pm = pm;
 323
 324         ieee80211_mps_sta_status_update(sta);
 325 }
 326
 327 /**
 328  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
 329  *
 330  * @sta: STA info that transmitted the frame
 331  * @hdr: IEEE 802.11 (QoS) Header
 332  */
 333 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 334                                     struct ieee80211_hdr *hdr)
 335 {
 336         if (is_unicast_ether_addr(hdr->addr1) &&
 337             ieee80211_is_data_qos(hdr->frame_control)) {
 338                 /*
 339                  * individually addressed QoS Data/Null frames contain
 340                  * peer link-specific PS mode towards the local STA
 341                  */
 342                 mps_set_sta_peer_pm(sta, hdr);
 343
 344                 /* check for mesh Peer Service Period trigger frames */
 345                 ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
 346                                                sta, false, false);
 347         } else {
 348                 /*
 349                  * can only determine non-peer PS mode
 350                  * (see IEEE802.11-2012 8.2.4.1.7)
 351                  */
 352                 mps_set_sta_nonpeer_pm(sta, hdr);
 353         }
 354 }
 355
 356
 357 /* mesh PS frame release */
 358
 359 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
 360 {
 361         struct ieee80211_sub_if_data *sdata = sta->sdata;
 362         struct sk_buff *skb;
 363         struct ieee80211_hdr *nullfunc;
 364         struct ieee80211_tx_info *info;
 365         u8 *qc;
 366
 367         skb = mps_qos_null_get(sta);
 368         if (!skb)
 369                 return;
 370
 371         nullfunc = (struct ieee80211_hdr *) skb->data;
 372         if (!eosp)
 373                 nullfunc->frame_control |=
 374                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 375         /*
 376          * | RSPI | EOSP |  MPSP triggering   |
 377          * +------+------+--------------------+
 378          * |  0   |  0   | local STA is owner |
 379          * |  0   |  1   | no MPSP (MPSP end) |
 380          * |  1   |  0   | both STA are owner |
 381          * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
 382          */
 383         qc = ieee80211_get_qos_ctl(nullfunc);
 384         if (rspi)
 385                 qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
 386         if (eosp)
 387                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
 388
 389         info = IEEE80211_SKB_CB(skb);
 390
 391         info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
 392                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 393
 394         mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
 395                 rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
 396
 397         ieee80211_tx_skb(sdata, skb);
 398 }
 399
 400 /**
 401  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
 402  *
 403  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
 404  * flag in the QoS Control field. In case the current tailing frame is not a
 405  * QoS Data frame, append a QoS Null to carry the flag.
 406  */
 407 static void mpsp_qos_null_append(struct sta_info *sta,
 408                                  struct sk_buff_head *frames)
 409 {
 410         struct ieee80211_sub_if_data *sdata = sta->sdata;
 411         struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
 412         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 413         struct ieee80211_tx_info *info;
 414
 415         if (ieee80211_is_data_qos(hdr->frame_control))
 416                 return;
 417
 418         new_skb = mps_qos_null_get(sta);
 419         if (!new_skb)
 420                 return;
 421
 422         mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
 423                 sta->sta.addr);
 424         /*
 425          * This frame has to be transmitted last. Assign lowest priority to
 426          * make sure it cannot pass other frames when releasing multiple ACs.
 427          */
 428         new_skb->priority = 1;
 429         skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
 430         ieee80211_set_qos_hdr(sdata, new_skb);
 431
 432         info = IEEE80211_SKB_CB(new_skb);
 433         info->control.vif = &sdata->vif;
 434         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 435
 436         __skb_queue_tail(frames, new_skb);
 437 }
 438
 439 /**
 440  * mps_frame_deliver - transmit frames during mesh powersave
 441  *
 442  * @sta: STA info to transmit to
 443  * @n_frames: number of frames to transmit. -1 for all
 444  */
 445 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
 446 {
 447         struct ieee80211_sub_if_data *sdata = sta->sdata;
 448         struct ieee80211_local *local = sdata->local;
 449         int ac;
 450         struct sk_buff_head frames;
 451         struct sk_buff *skb;
 452         bool more_data = false;
 453
 454         skb_queue_head_init(&frames);
 455
 456         /* collect frame(s) from buffers */
 457         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
 458                 while (n_frames != 0) {
 459                         skb = skb_dequeue(&sta->tx_filtered[ac]);
 460                         if (!skb) {
 461                                 skb = skb_dequeue(
 462                                         &sta->ps_tx_buf[ac]);
 463                                 if (skb)
 464                                         local->total_ps_buffered--;
 465                         }
 466                         if (!skb)
 467                                 break;
 468                         n_frames--;
 469                         __skb_queue_tail(&frames, skb);
 470                 }
 471
 472                 if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
 473                     !skb_queue_empty(&sta->ps_tx_buf[ac]))
 474                         more_data = true;
 475         }
 476
 477         /* nothing to send? -> EOSP */
 478         if (skb_queue_empty(&frames)) {
 479                 mpsp_trigger_send(sta, false, true);
 480                 return;
 481         }
 482
 483         /* in a MPSP make sure the last skb is a QoS Data frame */
 484         if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 485                 mpsp_qos_null_append(sta, &frames);
 486
 487         mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
 488                 skb_queue_len(&frames), sta->sta.addr);
 489
 490         /* prepare collected frames for transmission */
 491         skb_queue_walk(&frames, skb) {
 492                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 493                 struct ieee80211_hdr *hdr = (void *) skb->data;
 494
 495                 /*
 496                  * Tell TX path to send this frame even though the
 497                  * STA may still remain is PS mode after this frame
 498                  * exchange.
 499                  */
 500                 info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
 501
 502                 if (more_data || !skb_queue_is_last(&frames, skb))
 503                         hdr->frame_control |=
 504                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 505                 else
 506                         hdr->frame_control &=
 507                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 508
 509                 if (skb_queue_is_last(&frames, skb) &&
 510                     ieee80211_is_data_qos(hdr->frame_control)) {
 511                         u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
 512
 513                         /* MPSP trigger frame ends service period */
 514                         *qoshdr |= IEEE80211_QOS_CTL_EOSP;
 515                         info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 516                 }
 517         }
 518
 519         ieee80211_add_pending_skbs(local, &frames);
 520         sta_info_recalc_tim(sta);
 521 }
 522
 523 /**
 524  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
 525  *
 526  * @qc: QoS Control field
 527  * @sta: peer to start a MPSP with
 528  * @tx: frame was transmitted by the local STA
 529  * @acked: frame has been transmitted successfully
 530  *
 531  * NOTE: active mode STA may only serve as MPSP owner
 532  */
 533 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 534                                     bool tx, bool acked)
 535 {
 536         u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
 537         u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
 538
 539         if (tx) {
 540                 if (rspi && acked)
 541                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 542
 543                 if (eosp)
 544                         clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 545                 else if (acked &&
 546                          test_sta_flag(sta, WLAN_STA_PS_STA) &&
 547                          !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 548                         mps_frame_deliver(sta, -1);
 549         } else {
 550                 if (eosp)
 551                         clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 552                 else if (sta->local_pm != NL80211_MESH_POWER_ACTIVE)
 553                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 554
 555                 if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 556                         mps_frame_deliver(sta, -1);
 557         }
 558 }
 559
 560 /**
 561  * ieee80211_mps_frame_release - release buffered frames in response to beacon
 562  *
 563  * @sta: mesh STA
 564  * @elems: beacon IEs
 565  *
 566  * For peers if we have individually-addressed frames buffered or the peer
 567  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
 568  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
 569  * trigger frames. If the neighbour STA is not a peer, only send single frames.
 570  */
 571 void ieee80211_mps_frame_release(struct sta_info *sta,
 572                                  struct ieee802_11_elems *elems)
 573 {
 574         int ac, buffer_local = 0;
 575         bool has_buffered = false;
 576
 577         /* TIM map only for LLID <= IEEE80211_MAX_AID */
 578         if (sta->plink_state == NL80211_PLINK_ESTAB)
 579                 has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
 580                                 le16_to_cpu(sta->llid) % IEEE80211_MAX_AID);
 581
 582         if (has_buffered)
 583                 mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
 584                         sta->sta.addr);
 585
 586         /* only transmit to PS STA with announced, non-zero awake window */
 587         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 588             (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
 589                 return;
 590
 591         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
 592                 buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
 593                                 skb_queue_len(&sta->tx_filtered[ac]);
 594
 595         if (!has_buffered && !buffer_local)
 596                 return;
 597
 598         if (sta->plink_state == NL80211_PLINK_ESTAB)
 599                 mpsp_trigger_send(sta, has_buffered, !buffer_local);
 600         else
 601                 mps_frame_deliver(sta, 1);
 602 }