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         nullfunc->seq_ctrl = 0;
  40         /* no address resolution for this frame -> set addr 1 immediately */
  41         memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
  42         memset(skb_put(skb, 2), 0, 2); /* append QoS control field */
  43         ieee80211_mps_set_frame_flags(sdata, sta, nullfunc);
  44
  45         return skb;
  46 }
  47
  48 /**
  49  * mps_qos_null_tx - send a QoS Null to indicate link-specific power mode
  50  */
  51 static void mps_qos_null_tx(struct sta_info *sta)
  52 {
  53         struct sk_buff *skb;
  54
  55         skb = mps_qos_null_get(sta);
  56         if (!skb)
  57                 return;
  58
  59         mps_dbg(sta->sdata, "announcing peer-specific power mode to %pM\n",
  60                 sta->sta.addr);
  61
  62         /* don't unintentionally start a MPSP */
  63         if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
  64                 u8 *qc = ieee80211_get_qos_ctl((void *) skb->data);
  65
  66                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
  67         }
  68
  69         ieee80211_tx_skb(sta->sdata, skb);
  70 }
  71
  72 /**
  73  * ieee80211_mps_local_status_update - track status of local link-specific PMs
  74  *
  75  * @sdata: local mesh subif
  76  *
  77  * sets the non-peer power mode and triggers the driver PS (re-)configuration
  78  * Return BSS_CHANGED_BEACON if a beacon update is necessary.
  79  */
  80 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
  81 {
  82         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  83         struct sta_info *sta;
  84         bool peering = false;
  85         int light_sleep_cnt = 0;
  86         int deep_sleep_cnt = 0;
  87         u32 changed = 0;
  88         enum nl80211_mesh_power_mode nonpeer_pm;
  89
  90         rcu_read_lock();
  91         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
  92                 if (sdata != sta->sdata)
  93                         continue;
  94
  95                 switch (sta->mesh->plink_state) {
  96                 case NL80211_PLINK_OPN_SNT:
  97                 case NL80211_PLINK_OPN_RCVD:
  98                 case NL80211_PLINK_CNF_RCVD:
  99                         peering = true;
 100                         break;
 101                 case NL80211_PLINK_ESTAB:
 102                         if (sta->mesh->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
 103                                 light_sleep_cnt++;
 104                         else if (sta->mesh->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
 105                                 deep_sleep_cnt++;
 106                         break;
 107                 default:
 108                         break;
 109                 }
 110         }
 111         rcu_read_unlock();
 112
 113         /*
 114          * Set non-peer mode to active during peering/scanning/authentication
 115          * (see IEEE802.11-2012 13.14.8.3). The non-peer mesh power mode is
 116          * deep sleep if the local STA is in light or deep sleep towards at
 117          * least one mesh peer (see 13.14.3.1). Otherwise, set it to the
 118          * user-configured default value.
 119          */
 120         if (peering) {
 121                 mps_dbg(sdata, "setting non-peer PM to active for peering\n");
 122                 nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
 123         } else if (light_sleep_cnt || deep_sleep_cnt) {
 124                 mps_dbg(sdata, "setting non-peer PM to deep sleep\n");
 125                 nonpeer_pm = NL80211_MESH_POWER_DEEP_SLEEP;
 126         } else {
 127                 mps_dbg(sdata, "setting non-peer PM to user value\n");
 128                 nonpeer_pm = ifmsh->mshcfg.power_mode;
 129         }
 130
 131         /* need update if sleep counts move between 0 and non-zero */
 132         if (ifmsh->nonpeer_pm != nonpeer_pm ||
 133             !ifmsh->ps_peers_light_sleep != !light_sleep_cnt ||
 134             !ifmsh->ps_peers_deep_sleep != !deep_sleep_cnt)
 135                 changed = BSS_CHANGED_BEACON;
 136
 137         ifmsh->nonpeer_pm = nonpeer_pm;
 138         ifmsh->ps_peers_light_sleep = light_sleep_cnt;
 139         ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;
 140
 141         return changed;
 142 }
 143
 144 /**
 145  * ieee80211_mps_set_sta_local_pm - set local PM towards a mesh STA
 146  *
 147  * @sta: mesh STA
 148  * @pm: the power mode to set
 149  * Return BSS_CHANGED_BEACON if a beacon update is in order.
 150  */
 151 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
 152                                    enum nl80211_mesh_power_mode pm)
 153 {
 154         struct ieee80211_sub_if_data *sdata = sta->sdata;
 155
 156         if (sta->mesh->local_pm == pm)
 157                 return 0;
 158
 159         mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
 160                 pm, sta->sta.addr);
 161
 162         sta->mesh->local_pm = pm;
 163
 164         /*
 165          * announce peer-specific power mode transition
 166          * (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
 167          */
 168         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 169                 mps_qos_null_tx(sta);
 170
 171         return ieee80211_mps_local_status_update(sdata);
 172 }
 173
 174 /**
 175  * ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
 176  *
 177  * @sdata: local mesh subif
 178  * @sta: mesh STA
 179  * @hdr: 802.11 frame header
 180  *
 181  * see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
 182  *
 183  * NOTE: sta must be given when an individually-addressed QoS frame header
 184  * is handled, for group-addressed and management frames it is not used
 185  */
 186 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
 187                                    struct sta_info *sta,
 188                                    struct ieee80211_hdr *hdr)
 189 {
 190         enum nl80211_mesh_power_mode pm;
 191         u8 *qc;
 192
 193         if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
 194                     ieee80211_is_data_qos(hdr->frame_control) &&
 195                     !sta))
 196                 return;
 197
 198         if (is_unicast_ether_addr(hdr->addr1) &&
 199             ieee80211_is_data_qos(hdr->frame_control) &&
 200             sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 201                 pm = sta->mesh->local_pm;
 202         else
 203                 pm = sdata->u.mesh.nonpeer_pm;
 204
 205         if (pm == NL80211_MESH_POWER_ACTIVE)
 206                 hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
 207         else
 208                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
 209
 210         if (!ieee80211_is_data_qos(hdr->frame_control))
 211                 return;
 212
 213         qc = ieee80211_get_qos_ctl(hdr);
 214
 215         if ((is_unicast_ether_addr(hdr->addr1) &&
 216              pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
 217             (is_multicast_ether_addr(hdr->addr1) &&
 218              sdata->u.mesh.ps_peers_deep_sleep > 0))
 219                 qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 220         else
 221                 qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
 222 }
 223
 224 /**
 225  * ieee80211_mps_sta_status_update - update buffering status of neighbor STA
 226  *
 227  * @sta: mesh STA
 228  *
 229  * called after change of peering status or non-peer/peer-specific power mode
 230  */
 231 void ieee80211_mps_sta_status_update(struct sta_info *sta)
 232 {
 233         enum nl80211_mesh_power_mode pm;
 234         bool do_buffer;
 235
 236         /* For non-assoc STA, prevent buffering or frame transmission */
 237         if (sta->sta_state < IEEE80211_STA_ASSOC)
 238                 return;
 239
 240         /*
 241          * use peer-specific power mode if peering is established and the
 242          * peer's power mode is known
 243          */
 244         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 245             sta->mesh->peer_pm != NL80211_MESH_POWER_UNKNOWN)
 246                 pm = sta->mesh->peer_pm;
 247         else
 248                 pm = sta->mesh->nonpeer_pm;
 249
 250         do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
 251
 252         /* clear the MPSP flags for non-peers or active STA */
 253         if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) {
 254                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 255                 clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 256         } else if (!do_buffer) {
 257                 clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 258         }
 259
 260         /* Don't let the same PS state be set twice */
 261         if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
 262                 return;
 263
 264         if (do_buffer) {
 265                 set_sta_flag(sta, WLAN_STA_PS_STA);
 266                 atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
 267                 mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
 268                         sta->sta.addr);
 269         } else {
 270                 ieee80211_sta_ps_deliver_wakeup(sta);
 271         }
 272 }
 273
 274 static void mps_set_sta_peer_pm(struct sta_info *sta,
 275                                 struct ieee80211_hdr *hdr)
 276 {
 277         enum nl80211_mesh_power_mode pm;
 278         u8 *qc = ieee80211_get_qos_ctl(hdr);
 279
 280         /*
 281          * Test Power Management field of frame control (PW) and
 282          * mesh power save level subfield of QoS control field (PSL)
 283          *
 284          * | PM | PSL| Mesh PM |
 285          * +----+----+---------+
 286          * | 0  |Rsrv|  Active |
 287          * | 1  | 0  |  Light  |
 288          * | 1  | 1  |  Deep   |
 289          */
 290         if (ieee80211_has_pm(hdr->frame_control)) {
 291                 if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
 292                         pm = NL80211_MESH_POWER_DEEP_SLEEP;
 293                 else
 294                         pm = NL80211_MESH_POWER_LIGHT_SLEEP;
 295         } else {
 296                 pm = NL80211_MESH_POWER_ACTIVE;
 297         }
 298
 299         if (sta->mesh->peer_pm == pm)
 300                 return;
 301
 302         mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
 303                 sta->sta.addr, pm);
 304
 305         sta->mesh->peer_pm = pm;
 306
 307         ieee80211_mps_sta_status_update(sta);
 308 }
 309
 310 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
 311                                    struct ieee80211_hdr *hdr)
 312 {
 313         enum nl80211_mesh_power_mode pm;
 314
 315         if (ieee80211_has_pm(hdr->frame_control))
 316                 pm = NL80211_MESH_POWER_DEEP_SLEEP;
 317         else
 318                 pm = NL80211_MESH_POWER_ACTIVE;
 319
 320         if (sta->mesh->nonpeer_pm == pm)
 321                 return;
 322
 323         mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
 324                 sta->sta.addr, pm);
 325
 326         sta->mesh->nonpeer_pm = pm;
 327
 328         ieee80211_mps_sta_status_update(sta);
 329 }
 330
 331 /**
 332  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
 333  *
 334  * @sta: STA info that transmitted the frame
 335  * @hdr: IEEE 802.11 (QoS) Header
 336  */
 337 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 338                                     struct ieee80211_hdr *hdr)
 339 {
 340         if (is_unicast_ether_addr(hdr->addr1) &&
 341             ieee80211_is_data_qos(hdr->frame_control)) {
 342                 /*
 343                  * individually addressed QoS Data/Null frames contain
 344                  * peer link-specific PS mode towards the local STA
 345                  */
 346                 mps_set_sta_peer_pm(sta, hdr);
 347
 348                 /* check for mesh Peer Service Period trigger frames */
 349                 ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
 350                                                sta, false, false);
 351         } else {
 352                 /*
 353                  * can only determine non-peer PS mode
 354                  * (see IEEE802.11-2012 8.2.4.1.7)
 355                  */
 356                 mps_set_sta_nonpeer_pm(sta, hdr);
 357         }
 358 }
 359
 360
 361 /* mesh PS frame release */
 362
 363 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
 364 {
 365         struct ieee80211_sub_if_data *sdata = sta->sdata;
 366         struct sk_buff *skb;
 367         struct ieee80211_hdr *nullfunc;
 368         struct ieee80211_tx_info *info;
 369         u8 *qc;
 370
 371         skb = mps_qos_null_get(sta);
 372         if (!skb)
 373                 return;
 374
 375         nullfunc = (struct ieee80211_hdr *) skb->data;
 376         if (!eosp)
 377                 nullfunc->frame_control |=
 378                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 379         /*
 380          * | RSPI | EOSP |  MPSP triggering   |
 381          * +------+------+--------------------+
 382          * |  0   |  0   | local STA is owner |
 383          * |  0   |  1   | no MPSP (MPSP end) |
 384          * |  1   |  0   | both STA are owner |
 385          * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
 386          */
 387         qc = ieee80211_get_qos_ctl(nullfunc);
 388         if (rspi)
 389                 qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
 390         if (eosp)
 391                 qc[0] |= IEEE80211_QOS_CTL_EOSP;
 392
 393         info = IEEE80211_SKB_CB(skb);
 394
 395         info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
 396                        IEEE80211_TX_CTL_REQ_TX_STATUS;
 397
 398         mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
 399                 rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
 400
 401         ieee80211_tx_skb(sdata, skb);
 402 }
 403
 404 /**
 405  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
 406  *
 407  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
 408  * flag in the QoS Control field. In case the current tailing frame is not a
 409  * QoS Data frame, append a QoS Null to carry the flag.
 410  */
 411 static void mpsp_qos_null_append(struct sta_info *sta,
 412                                  struct sk_buff_head *frames)
 413 {
 414         struct ieee80211_sub_if_data *sdata = sta->sdata;
 415         struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
 416         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 417         struct ieee80211_tx_info *info;
 418
 419         if (ieee80211_is_data_qos(hdr->frame_control))
 420                 return;
 421
 422         new_skb = mps_qos_null_get(sta);
 423         if (!new_skb)
 424                 return;
 425
 426         mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
 427                 sta->sta.addr);
 428         /*
 429          * This frame has to be transmitted last. Assign lowest priority to
 430          * make sure it cannot pass other frames when releasing multiple ACs.
 431          */
 432         new_skb->priority = 1;
 433         skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
 434         ieee80211_set_qos_hdr(sdata, new_skb);
 435
 436         info = IEEE80211_SKB_CB(new_skb);
 437         info->control.vif = &sdata->vif;
 438         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
 439
 440         __skb_queue_tail(frames, new_skb);
 441 }
 442
 443 /**
 444  * mps_frame_deliver - transmit frames during mesh powersave
 445  *
 446  * @sta: STA info to transmit to
 447  * @n_frames: number of frames to transmit. -1 for all
 448  */
 449 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
 450 {
 451         struct ieee80211_local *local = sta->sdata->local;
 452         int ac;
 453         struct sk_buff_head frames;
 454         struct sk_buff *skb;
 455         bool more_data = false;
 456
 457         skb_queue_head_init(&frames);
 458
 459         /* collect frame(s) from buffers */
 460         for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
 461                 while (n_frames != 0) {
 462                         skb = skb_dequeue(&sta->tx_filtered[ac]);
 463                         if (!skb) {
 464                                 skb = skb_dequeue(
 465                                         &sta->ps_tx_buf[ac]);
 466                                 if (skb)
 467                                         local->total_ps_buffered--;
 468                         }
 469                         if (!skb)
 470                                 break;
 471                         n_frames--;
 472                         __skb_queue_tail(&frames, skb);
 473                 }
 474
 475                 if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
 476                     !skb_queue_empty(&sta->ps_tx_buf[ac]))
 477                         more_data = true;
 478         }
 479
 480         /* nothing to send? -> EOSP */
 481         if (skb_queue_empty(&frames)) {
 482                 mpsp_trigger_send(sta, false, true);
 483                 return;
 484         }
 485
 486         /* in a MPSP make sure the last skb is a QoS Data frame */
 487         if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 488                 mpsp_qos_null_append(sta, &frames);
 489
 490         mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
 491                 skb_queue_len(&frames), sta->sta.addr);
 492
 493         /* prepare collected frames for transmission */
 494         skb_queue_walk(&frames, skb) {
 495                 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 496                 struct ieee80211_hdr *hdr = (void *) skb->data;
 497
 498                 /*
 499                  * Tell TX path to send this frame even though the
 500                  * STA may still remain is PS mode after this frame
 501                  * exchange.
 502                  */
 503                 info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
 504
 505                 if (more_data || !skb_queue_is_last(&frames, skb))
 506                         hdr->frame_control |=
 507                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 508                 else
 509                         hdr->frame_control &=
 510                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 511
 512                 if (skb_queue_is_last(&frames, skb) &&
 513                     ieee80211_is_data_qos(hdr->frame_control)) {
 514                         u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
 515
 516                         /* MPSP trigger frame ends service period */
 517                         *qoshdr |= IEEE80211_QOS_CTL_EOSP;
 518                         info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 519                 }
 520         }
 521
 522         ieee80211_add_pending_skbs(local, &frames);
 523         sta_info_recalc_tim(sta);
 524 }
 525
 526 /**
 527  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
 528  *
 529  * @qc: QoS Control field
 530  * @sta: peer to start a MPSP with
 531  * @tx: frame was transmitted by the local STA
 532  * @acked: frame has been transmitted successfully
 533  *
 534  * NOTE: active mode STA may only serve as MPSP owner
 535  */
 536 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 537                                     bool tx, bool acked)
 538 {
 539         u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
 540         u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
 541
 542         if (tx) {
 543                 if (rspi && acked)
 544                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 545
 546                 if (eosp)
 547                         clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
 548                 else if (acked &&
 549                          test_sta_flag(sta, WLAN_STA_PS_STA) &&
 550                          !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 551                         mps_frame_deliver(sta, -1);
 552         } else {
 553                 if (eosp)
 554                         clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 555                 else if (sta->mesh->local_pm != NL80211_MESH_POWER_ACTIVE)
 556                         set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
 557
 558                 if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 559                         mps_frame_deliver(sta, -1);
 560         }
 561 }
 562
 563 /**
 564  * ieee80211_mps_frame_release - release frames buffered due to mesh power save
 565  *
 566  * @sta: mesh STA
 567  * @elems: IEs of beacon or probe response
 568  *
 569  * For peers if we have individually-addressed frames buffered or the peer
 570  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
 571  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
 572  * trigger frames. If the neighbour STA is not a peer, only send single frames.
 573  */
 574 void ieee80211_mps_frame_release(struct sta_info *sta,
 575                                  struct ieee802_11_elems *elems)
 576 {
 577         int ac, buffer_local = 0;
 578         bool has_buffered = false;
 579
 580         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 581                 has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
 582                                                    sta->mesh->aid);
 583
 584         if (has_buffered)
 585                 mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
 586                         sta->sta.addr);
 587
 588         /* only transmit to PS STA with announced, non-zero awake window */
 589         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 590             (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
 591                 return;
 592
 593         if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
 594                 for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
 595                         buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
 596                                         skb_queue_len(&sta->tx_filtered[ac]);
 597
 598         if (!has_buffered && !buffer_local)
 599                 return;
 600
 601         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 602                 mpsp_trigger_send(sta, has_buffered, !buffer_local);
 603         else
 604                 mps_frame_deliver(sta, 1);
 605 }