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