net/mac80211/status.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2008-2010  Johannes Berg <johannes@sipsolutions.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/export.h>
  13 #include <linux/etherdevice.h>
  14 #include <net/mac80211.h>
  15 #include <asm/unaligned.h>
  16 #include "ieee80211_i.h"
  17 #include "rate.h"
  18 #include "mesh.h"
  19 #include "led.h"
  20 #include "wme.h"
  21
  22
  23 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
  24                                  struct sk_buff *skb)
  25 {
  26         struct ieee80211_local *local = hw_to_local(hw);
  27         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  28         int tmp;
  29
  30         skb->pkt_type = IEEE80211_TX_STATUS_MSG;
  31         skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
  32                        &local->skb_queue : &local->skb_queue_unreliable, skb);
  33         tmp = skb_queue_len(&local->skb_queue) +
  34                 skb_queue_len(&local->skb_queue_unreliable);
  35         while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
  36                (skb = skb_dequeue(&local->skb_queue_unreliable))) {
  37                 dev_kfree_skb_irq(skb);
  38                 tmp--;
  39                 I802_DEBUG_INC(local->tx_status_drop);
  40         }
  41         tasklet_schedule(&local->tasklet);
  42 }
  43 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
  44
  45 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
  46                                             struct sta_info *sta,
  47                                             struct sk_buff *skb)
  48 {
  49         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  50         struct ieee80211_hdr *hdr = (void *)skb->data;
  51         int ac;
  52
  53         /*
  54          * This skb 'survived' a round-trip through the driver, and
  55          * hopefully the driver didn't mangle it too badly. However,
  56          * we can definitely not rely on the control information
  57          * being correct. Clear it so we don't get junk there, and
  58          * indicate that it needs new processing, but must not be
  59          * modified/encrypted again.
  60          */
  61         memset(&info->control, 0, sizeof(info->control));
  62
  63         info->control.jiffies = jiffies;
  64         info->control.vif = &sta->sdata->vif;
  65         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
  66                        IEEE80211_TX_INTFL_RETRANSMISSION;
  67         info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
  68
  69         sta->tx_filtered_count++;
  70
  71         /*
  72          * Clear more-data bit on filtered frames, it might be set
  73          * but later frames might time out so it might have to be
  74          * clear again ... It's all rather unlikely (this frame
  75          * should time out first, right?) but let's not confuse
  76          * peers unnecessarily.
  77          */
  78         if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
  79                 hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
  80
  81         if (ieee80211_is_data_qos(hdr->frame_control)) {
  82                 u8 *p = ieee80211_get_qos_ctl(hdr);
  83                 int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
  84
  85                 /*
  86                  * Clear EOSP if set, this could happen e.g.
  87                  * if an absence period (us being a P2P GO)
  88                  * shortens the SP.
  89                  */
  90                 if (*p & IEEE80211_QOS_CTL_EOSP)
  91                         *p &= ~IEEE80211_QOS_CTL_EOSP;
  92                 ac = ieee802_1d_to_ac[tid & 7];
  93         } else {
  94                 ac = IEEE80211_AC_BE;
  95         }
  96
  97         /*
  98          * Clear the TX filter mask for this STA when sending the next
  99          * packet. If the STA went to power save mode, this will happen
 100          * when it wakes up for the next time.
 101          */
 102         set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
 103
 104         /*
 105          * This code races in the following way:
 106          *
 107          *  (1) STA sends frame indicating it will go to sleep and does so
 108          *  (2) hardware/firmware adds STA to filter list, passes frame up
 109          *  (3) hardware/firmware processes TX fifo and suppresses a frame
 110          *  (4) we get TX status before having processed the frame and
 111          *      knowing that the STA has gone to sleep.
 112          *
 113          * This is actually quite unlikely even when both those events are
 114          * processed from interrupts coming in quickly after one another or
 115          * even at the same time because we queue both TX status events and
 116          * RX frames to be processed by a tasklet and process them in the
 117          * same order that they were received or TX status last. Hence, there
 118          * is no race as long as the frame RX is processed before the next TX
 119          * status, which drivers can ensure, see below.
 120          *
 121          * Note that this can only happen if the hardware or firmware can
 122          * actually add STAs to the filter list, if this is done by the
 123          * driver in response to set_tim() (which will only reduce the race
 124          * this whole filtering tries to solve, not completely solve it)
 125          * this situation cannot happen.
 126          *
 127          * To completely solve this race drivers need to make sure that they
 128          *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
 129          *      functions and
 130          *  (b) always process RX events before TX status events if ordering
 131          *      can be unknown, for example with different interrupt status
 132          *      bits.
 133          *  (c) if PS mode transitions are manual (i.e. the flag
 134          *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
 135          *      changes before calling TX status events if ordering can be
 136          *      unknown.
 137          */
 138         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 139             skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
 140                 skb_queue_tail(&sta->tx_filtered[ac], skb);
 141                 sta_info_recalc_tim(sta);
 142
 143                 if (!timer_pending(&local->sta_cleanup))
 144                         mod_timer(&local->sta_cleanup,
 145                                   round_jiffies(jiffies +
 146                                                 STA_INFO_CLEANUP_INTERVAL));
 147                 return;
 148         }
 149
 150         if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
 151             !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
 152                 /* Software retry the packet once */
 153                 info->flags |= IEEE80211_TX_INTFL_RETRIED;
 154                 ieee80211_add_pending_skb(local, skb);
 155                 return;
 156         }
 157
 158 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 159         if (net_ratelimit())
 160                 wiphy_debug(local->hw.wiphy,
 161                             "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
 162                             skb_queue_len(&sta->tx_filtered[ac]),
 163                             !!test_sta_flag(sta, WLAN_STA_PS_STA), jiffies);
 164 #endif
 165         dev_kfree_skb(skb);
 166 }
 167
 168 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
 169 {
 170         struct tid_ampdu_tx *tid_tx;
 171
 172         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 173         if (!tid_tx || !tid_tx->bar_pending)
 174                 return;
 175
 176         tid_tx->bar_pending = false;
 177         ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
 178 }
 179
 180 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 181 {
 182         struct ieee80211_mgmt *mgmt = (void *) skb->data;
 183         struct ieee80211_local *local = sta->local;
 184         struct ieee80211_sub_if_data *sdata = sta->sdata;
 185
 186         if (ieee80211_is_data_qos(mgmt->frame_control)) {
 187                 struct ieee80211_hdr *hdr = (void *) skb->data;
 188                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 189                 u16 tid = qc[0] & 0xf;
 190
 191                 ieee80211_check_pending_bar(sta, hdr->addr1, tid);
 192         }
 193
 194         if (ieee80211_is_action(mgmt->frame_control) &&
 195             sdata->vif.type == NL80211_IFTYPE_STATION &&
 196             mgmt->u.action.category == WLAN_CATEGORY_HT &&
 197             mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
 198                 /*
 199                  * This update looks racy, but isn't -- if we come
 200                  * here we've definitely got a station that we're
 201                  * talking to, and on a managed interface that can
 202                  * only be the AP. And the only other place updating
 203                  * this variable is before we're associated.
 204                  */
 205                 switch (mgmt->u.action.u.ht_smps.smps_control) {
 206                 case WLAN_HT_SMPS_CONTROL_DYNAMIC:
 207                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
 208                         break;
 209                 case WLAN_HT_SMPS_CONTROL_STATIC:
 210                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
 211                         break;
 212                 case WLAN_HT_SMPS_CONTROL_DISABLED:
 213                 default: /* shouldn't happen since we don't send that */
 214                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
 215                         break;
 216                 }
 217
 218                 ieee80211_queue_work(&local->hw, &local->recalc_smps);
 219         }
 220 }
 221
 222 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
 223 {
 224         struct tid_ampdu_tx *tid_tx;
 225
 226         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 227         if (!tid_tx)
 228                 return;
 229
 230         tid_tx->failed_bar_ssn = ssn;
 231         tid_tx->bar_pending = true;
 232 }
 233
 234 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
 235 {
 236         int len = sizeof(struct ieee80211_radiotap_header);
 237
 238         /* IEEE80211_RADIOTAP_RATE rate */
 239         if (info->status.rates[0].idx >= 0 &&
 240             !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
 241                 len += 2;
 242
 243         /* IEEE80211_RADIOTAP_TX_FLAGS */
 244         len += 2;
 245
 246         /* IEEE80211_RADIOTAP_DATA_RETRIES */
 247         len += 1;
 248
 249         /* IEEE80211_TX_RC_MCS */
 250         if (info->status.rates[0].idx >= 0 &&
 251             info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
 252                 len += 3;
 253
 254         return len;
 255 }
 256
 257 static void ieee80211_add_tx_radiotap_header(struct ieee80211_supported_band
 258                                              *sband, struct sk_buff *skb,
 259                                              int retry_count, int rtap_len)
 260 {
 261         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 262         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 263         struct ieee80211_radiotap_header *rthdr;
 264         unsigned char *pos;
 265         u16 txflags;
 266
 267         rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
 268
 269         memset(rthdr, 0, rtap_len);
 270         rthdr->it_len = cpu_to_le16(rtap_len);
 271         rthdr->it_present =
 272                 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
 273                             (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
 274         pos = (unsigned char *)(rthdr + 1);
 275
 276         /*
 277          * XXX: Once radiotap gets the bitmap reset thing the vendor
 278          *      extensions proposal contains, we can actually report
 279          *      the whole set of tries we did.
 280          */
 281
 282         /* IEEE80211_RADIOTAP_RATE */
 283         if (info->status.rates[0].idx >= 0 &&
 284             !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS)) {
 285                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 286                 *pos = sband->bitrates[info->status.rates[0].idx].bitrate / 5;
 287                 /* padding for tx flags */
 288                 pos += 2;
 289         }
 290
 291         /* IEEE80211_RADIOTAP_TX_FLAGS */
 292         txflags = 0;
 293         if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
 294             !is_multicast_ether_addr(hdr->addr1))
 295                 txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
 296
 297         if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
 298             (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
 299                 txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
 300         else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
 301                 txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
 302
 303         put_unaligned_le16(txflags, pos);
 304         pos += 2;
 305
 306         /* IEEE80211_RADIOTAP_DATA_RETRIES */
 307         /* for now report the total retry_count */
 308         *pos = retry_count;
 309         pos++;
 310
 311         /* IEEE80211_TX_RC_MCS */
 312         if (info->status.rates[0].idx >= 0 &&
 313             info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
 314                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 315                 pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 316                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 317                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 318                 if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
 319                         pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
 320                 if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 321                         pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
 322                 if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
 323                         pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
 324                 pos[2] = info->status.rates[0].idx;
 325                 pos += 3;
 326         }
 327
 328 }
 329
 330 /*
 331  * Use a static threshold for now, best value to be determined
 332  * by testing ...
 333  * Should it depend on:
 334  *  - on # of retransmissions
 335  *  - current throughput (higher value for higher tpt)?
 336  */
 337 #define STA_LOST_PKT_THRESHOLD  50
 338
 339 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 340 {
 341         struct sk_buff *skb2;
 342         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 343         struct ieee80211_local *local = hw_to_local(hw);
 344         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 345         __le16 fc;
 346         struct ieee80211_supported_band *sband;
 347         struct ieee80211_sub_if_data *sdata;
 348         struct net_device *prev_dev = NULL;
 349         struct sta_info *sta, *tmp;
 350         int retry_count = -1, i;
 351         int rates_idx = -1;
 352         bool send_to_cooked;
 353         bool acked;
 354         struct ieee80211_bar *bar;
 355         int rtap_len;
 356
 357         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 358                 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 359                     !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
 360                         /* just the first aggr frame carry status info */
 361                         info->status.rates[i].idx = -1;
 362                         info->status.rates[i].count = 0;
 363                         break;
 364                 } else if (info->status.rates[i].idx < 0) {
 365                         break;
 366                 } else if (i >= hw->max_report_rates) {
 367                         /* the HW cannot have attempted that rate */
 368                         info->status.rates[i].idx = -1;
 369                         info->status.rates[i].count = 0;
 370                         break;
 371                 }
 372
 373                 retry_count += info->status.rates[i].count;
 374         }
 375         rates_idx = i - 1;
 376
 377         if (retry_count < 0)
 378                 retry_count = 0;
 379
 380         rcu_read_lock();
 381
 382         sband = local->hw.wiphy->bands[info->band];
 383         fc = hdr->frame_control;
 384
 385         for_each_sta_info(local, hdr->addr1, sta, tmp) {
 386                 /* skip wrong virtual interface */
 387                 if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
 388                         continue;
 389
 390                 if (info->flags & IEEE80211_TX_STATUS_EOSP)
 391                         clear_sta_flag(sta, WLAN_STA_SP);
 392
 393                 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
 394                 if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
 395                         /*
 396                          * The STA is in power save mode, so assume
 397                          * that this TX packet failed because of that.
 398                          */
 399                         ieee80211_handle_filtered_frame(local, sta, skb);
 400                         rcu_read_unlock();
 401                         return;
 402                 }
 403
 404                 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
 405                     (rates_idx != -1))
 406                         sta->last_tx_rate = info->status.rates[rates_idx];
 407
 408                 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
 409                     (ieee80211_is_data_qos(fc))) {
 410                         u16 tid, ssn;
 411                         u8 *qc;
 412
 413                         qc = ieee80211_get_qos_ctl(hdr);
 414                         tid = qc[0] & 0xf;
 415                         ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
 416                                                 & IEEE80211_SCTL_SEQ);
 417                         ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
 418                                            tid, ssn);
 419                 }
 420
 421                 if (!acked && ieee80211_is_back_req(fc)) {
 422                         u16 tid, control;
 423
 424                         /*
 425                          * BAR failed, store the last SSN and retry sending
 426                          * the BAR when the next unicast transmission on the
 427                          * same TID succeeds.
 428                          */
 429                         bar = (struct ieee80211_bar *) skb->data;
 430                         control = le16_to_cpu(bar->control);
 431                         if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
 432                                 u16 ssn = le16_to_cpu(bar->start_seq_num);
 433
 434                                 tid = (control &
 435                                        IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
 436                                       IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
 437
 438                                 ieee80211_set_bar_pending(sta, tid, ssn);
 439                         }
 440                 }
 441
 442                 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
 443                         ieee80211_handle_filtered_frame(local, sta, skb);
 444                         rcu_read_unlock();
 445                         return;
 446                 } else {
 447                         if (!acked)
 448                                 sta->tx_retry_failed++;
 449                         sta->tx_retry_count += retry_count;
 450                 }
 451
 452                 rate_control_tx_status(local, sband, sta, skb);
 453                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 454                         ieee80211s_update_metric(local, sta, skb);
 455
 456                 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
 457                         ieee80211_frame_acked(sta, skb);
 458
 459                 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
 460                     (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
 461                         ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
 462
 463                 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
 464                         if (info->flags & IEEE80211_TX_STAT_ACK) {
 465                                 if (sta->lost_packets)
 466                                         sta->lost_packets = 0;
 467                         } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
 468                                 cfg80211_cqm_pktloss_notify(sta->sdata->dev,
 469                                                             sta->sta.addr,
 470                                                             sta->lost_packets,
 471                                                             GFP_ATOMIC);
 472                                 sta->lost_packets = 0;
 473                         }
 474                 }
 475         }
 476
 477         rcu_read_unlock();
 478
 479         ieee80211_led_tx(local, 0);
 480
 481         /* SNMP counters
 482          * Fragments are passed to low-level drivers as separate skbs, so these
 483          * are actually fragments, not frames. Update frame counters only for
 484          * the first fragment of the frame. */
 485         if (info->flags & IEEE80211_TX_STAT_ACK) {
 486                 if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
 487                         local->dot11TransmittedFrameCount++;
 488                         if (is_multicast_ether_addr(hdr->addr1))
 489                                 local->dot11MulticastTransmittedFrameCount++;
 490                         if (retry_count > 0)
 491                                 local->dot11RetryCount++;
 492                         if (retry_count > 1)
 493                                 local->dot11MultipleRetryCount++;
 494                 }
 495
 496                 /* This counter shall be incremented for an acknowledged MPDU
 497                  * with an individual address in the address 1 field or an MPDU
 498                  * with a multicast address in the address 1 field of type Data
 499                  * or Management. */
 500                 if (!is_multicast_ether_addr(hdr->addr1) ||
 501                     ieee80211_is_data(fc) ||
 502                     ieee80211_is_mgmt(fc))
 503                         local->dot11TransmittedFragmentCount++;
 504         } else {
 505                 if (ieee80211_is_first_frag(hdr->seq_ctrl))
 506                         local->dot11FailedCount++;
 507         }
 508
 509         if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
 510             (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
 511             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 512             local->ps_sdata && !(local->scanning)) {
 513                 if (info->flags & IEEE80211_TX_STAT_ACK) {
 514                         local->ps_sdata->u.mgd.flags |=
 515                                         IEEE80211_STA_NULLFUNC_ACKED;
 516                 } else
 517                         mod_timer(&local->dynamic_ps_timer, jiffies +
 518                                         msecs_to_jiffies(10));
 519         }
 520
 521         if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
 522                 u64 cookie = (unsigned long)skb;
 523
 524                 if (ieee80211_is_nullfunc(hdr->frame_control) ||
 525                     ieee80211_is_qos_nullfunc(hdr->frame_control)) {
 526                         acked = info->flags & IEEE80211_TX_STAT_ACK;
 527
 528                         cfg80211_probe_status(skb->dev, hdr->addr1,
 529                                               cookie, acked, GFP_ATOMIC);
 530                 } else {
 531                         struct ieee80211_work *wk;
 532
 533                         rcu_read_lock();
 534                         list_for_each_entry_rcu(wk, &local->work_list, list) {
 535                                 if (wk->type != IEEE80211_WORK_OFFCHANNEL_TX)
 536                                         continue;
 537                                 if (wk->offchan_tx.frame != skb)
 538                                         continue;
 539                                 wk->offchan_tx.status = true;
 540                                 break;
 541                         }
 542                         rcu_read_unlock();
 543                         if (local->hw_roc_skb_for_status == skb) {
 544                                 cookie = local->hw_roc_cookie ^ 2;
 545                                 local->hw_roc_skb_for_status = NULL;
 546                         }
 547
 548                         cfg80211_mgmt_tx_status(
 549                                 skb->dev, cookie, skb->data, skb->len,
 550                                 !!(info->flags & IEEE80211_TX_STAT_ACK),
 551                                 GFP_ATOMIC);
 552                 }
 553         }
 554
 555         if (unlikely(info->ack_frame_id)) {
 556                 struct sk_buff *ack_skb;
 557                 unsigned long flags;
 558
 559                 spin_lock_irqsave(&local->ack_status_lock, flags);
 560                 ack_skb = idr_find(&local->ack_status_frames,
 561                                    info->ack_frame_id);
 562                 if (ack_skb)
 563                         idr_remove(&local->ack_status_frames,
 564                                    info->ack_frame_id);
 565                 spin_unlock_irqrestore(&local->ack_status_lock, flags);
 566
 567                 /* consumes ack_skb */
 568                 if (ack_skb)
 569                         skb_complete_wifi_ack(ack_skb,
 570                                 info->flags & IEEE80211_TX_STAT_ACK);
 571         }
 572
 573         /* this was a transmitted frame, but now we want to reuse it */
 574         skb_orphan(skb);
 575
 576         /* Need to make a copy before skb->cb gets cleared */
 577         send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
 578                          !(ieee80211_is_data(fc));
 579
 580         /*
 581          * This is a bit racy but we can avoid a lot of work
 582          * with this test...
 583          */
 584         if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
 585                 dev_kfree_skb(skb);
 586                 return;
 587         }
 588
 589         /* send frame to monitor interfaces now */
 590         rtap_len = ieee80211_tx_radiotap_len(info);
 591         if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
 592                 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
 593                 dev_kfree_skb(skb);
 594                 return;
 595         }
 596         ieee80211_add_tx_radiotap_header(sband, skb, retry_count, rtap_len);
 597
 598         /* XXX: is this sufficient for BPF? */
 599         skb_set_mac_header(skb, 0);
 600         skb->ip_summed = CHECKSUM_UNNECESSARY;
 601         skb->pkt_type = PACKET_OTHERHOST;
 602         skb->protocol = htons(ETH_P_802_2);
 603         memset(skb->cb, 0, sizeof(skb->cb));
 604
 605         rcu_read_lock();
 606         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 607                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
 608                         if (!ieee80211_sdata_running(sdata))
 609                                 continue;
 610
 611                         if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
 612                             !send_to_cooked)
 613                                 continue;
 614
 615                         if (prev_dev) {
 616                                 skb2 = skb_clone(skb, GFP_ATOMIC);
 617                                 if (skb2) {
 618                                         skb2->dev = prev_dev;
 619                                         netif_rx(skb2);
 620                                 }
 621                         }
 622
 623                         prev_dev = sdata->dev;
 624                 }
 625         }
 626         if (prev_dev) {
 627                 skb->dev = prev_dev;
 628                 netif_rx(skb);
 629                 skb = NULL;
 630         }
 631         rcu_read_unlock();
 632         dev_kfree_skb(skb);
 633 }
 634 EXPORT_SYMBOL(ieee80211_tx_status);
 635
 636 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
 637 {
 638         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 639         cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
 640                                     num_packets, GFP_ATOMIC);
 641 }
 642 EXPORT_SYMBOL(ieee80211_report_low_ack);
 643
 644 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
 645 {
 646         struct ieee80211_local *local = hw_to_local(hw);
 647         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 648
 649         if (unlikely(info->ack_frame_id)) {
 650                 struct sk_buff *ack_skb;
 651                 unsigned long flags;
 652
 653                 spin_lock_irqsave(&local->ack_status_lock, flags);
 654                 ack_skb = idr_find(&local->ack_status_frames,
 655                                    info->ack_frame_id);
 656                 if (ack_skb)
 657                         idr_remove(&local->ack_status_frames,
 658                                    info->ack_frame_id);
 659                 spin_unlock_irqrestore(&local->ack_status_lock, flags);
 660
 661                 /* consumes ack_skb */
 662                 if (ack_skb)
 663                         dev_kfree_skb_any(ack_skb);
 664         }
 665
 666         dev_kfree_skb_any(skb);
 667 }
 668 EXPORT_SYMBOL(ieee80211_free_txskb);