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 <linux/time.h>
  15 #include <net/mac80211.h>
  16 #include <asm/unaligned.h>
  17 #include "ieee80211_i.h"
  18 #include "rate.h"
  19 #include "mesh.h"
  20 #include "led.h"
  21 #include "wme.h"
  22
  23
  24 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
  25                                  struct sk_buff *skb)
  26 {
  27         struct ieee80211_local *local = hw_to_local(hw);
  28         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  29         int tmp;
  30
  31         skb->pkt_type = IEEE80211_TX_STATUS_MSG;
  32         skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
  33                        &local->skb_queue : &local->skb_queue_unreliable, skb);
  34         tmp = skb_queue_len(&local->skb_queue) +
  35                 skb_queue_len(&local->skb_queue_unreliable);
  36         while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
  37                (skb = skb_dequeue(&local->skb_queue_unreliable))) {
  38                 ieee80211_free_txskb(hw, skb);
  39                 tmp--;
  40                 I802_DEBUG_INC(local->tx_status_drop);
  41         }
  42         tasklet_schedule(&local->tasklet);
  43 }
  44 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
  45
  46 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
  47                                             struct sta_info *sta,
  48                                             struct sk_buff *skb)
  49 {
  50         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  51         struct ieee80211_hdr *hdr = (void *)skb->data;
  52         int ac;
  53
  54         /*
  55          * This skb 'survived' a round-trip through the driver, and
  56          * hopefully the driver didn't mangle it too badly. However,
  57          * we can definitely not rely on the control information
  58          * being correct. Clear it so we don't get junk there, and
  59          * indicate that it needs new processing, but must not be
  60          * modified/encrypted again.
  61          */
  62         memset(&info->control, 0, sizeof(info->control));
  63
  64         info->control.jiffies = jiffies;
  65         info->control.vif = &sta->sdata->vif;
  66         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
  67                        IEEE80211_TX_INTFL_RETRANSMISSION;
  68         info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
  69
  70         sta->tx_filtered_count++;
  71
  72         /*
  73          * Clear more-data bit on filtered frames, it might be set
  74          * but later frames might time out so it might have to be
  75          * clear again ... It's all rather unlikely (this frame
  76          * should time out first, right?) but let's not confuse
  77          * peers unnecessarily.
  78          */
  79         if (hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_MOREDATA))
  80                 hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_MOREDATA);
  81
  82         if (ieee80211_is_data_qos(hdr->frame_control)) {
  83                 u8 *p = ieee80211_get_qos_ctl(hdr);
  84                 int tid = *p & IEEE80211_QOS_CTL_TID_MASK;
  85
  86                 /*
  87                  * Clear EOSP if set, this could happen e.g.
  88                  * if an absence period (us being a P2P GO)
  89                  * shortens the SP.
  90                  */
  91                 if (*p & IEEE80211_QOS_CTL_EOSP)
  92                         *p &= ~IEEE80211_QOS_CTL_EOSP;
  93                 ac = ieee802_1d_to_ac[tid & 7];
  94         } else {
  95                 ac = IEEE80211_AC_BE;
  96         }
  97
  98         /*
  99          * Clear the TX filter mask for this STA when sending the next
 100          * packet. If the STA went to power save mode, this will happen
 101          * when it wakes up for the next time.
 102          */
 103         set_sta_flag(sta, WLAN_STA_CLEAR_PS_FILT);
 104
 105         /*
 106          * This code races in the following way:
 107          *
 108          *  (1) STA sends frame indicating it will go to sleep and does so
 109          *  (2) hardware/firmware adds STA to filter list, passes frame up
 110          *  (3) hardware/firmware processes TX fifo and suppresses a frame
 111          *  (4) we get TX status before having processed the frame and
 112          *      knowing that the STA has gone to sleep.
 113          *
 114          * This is actually quite unlikely even when both those events are
 115          * processed from interrupts coming in quickly after one another or
 116          * even at the same time because we queue both TX status events and
 117          * RX frames to be processed by a tasklet and process them in the
 118          * same order that they were received or TX status last. Hence, there
 119          * is no race as long as the frame RX is processed before the next TX
 120          * status, which drivers can ensure, see below.
 121          *
 122          * Note that this can only happen if the hardware or firmware can
 123          * actually add STAs to the filter list, if this is done by the
 124          * driver in response to set_tim() (which will only reduce the race
 125          * this whole filtering tries to solve, not completely solve it)
 126          * this situation cannot happen.
 127          *
 128          * To completely solve this race drivers need to make sure that they
 129          *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
 130          *      functions and
 131          *  (b) always process RX events before TX status events if ordering
 132          *      can be unknown, for example with different interrupt status
 133          *      bits.
 134          *  (c) if PS mode transitions are manual (i.e. the flag
 135          *      %IEEE80211_HW_AP_LINK_PS is set), always process PS state
 136          *      changes before calling TX status events if ordering can be
 137          *      unknown.
 138          */
 139         if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
 140             skb_queue_len(&sta->tx_filtered[ac]) < STA_MAX_TX_BUFFER) {
 141                 skb_queue_tail(&sta->tx_filtered[ac], skb);
 142                 sta_info_recalc_tim(sta);
 143
 144                 if (!timer_pending(&local->sta_cleanup))
 145                         mod_timer(&local->sta_cleanup,
 146                                   round_jiffies(jiffies +
 147                                                 STA_INFO_CLEANUP_INTERVAL));
 148                 return;
 149         }
 150
 151         if (!test_sta_flag(sta, WLAN_STA_PS_STA) &&
 152             !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
 153                 /* Software retry the packet once */
 154                 info->flags |= IEEE80211_TX_INTFL_RETRIED;
 155                 ieee80211_add_pending_skb(local, skb);
 156                 return;
 157         }
 158
 159         ps_dbg_ratelimited(sta->sdata,
 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         ieee80211_free_txskb(&local->hw, skb);
 164 }
 165
 166 static void ieee80211_check_pending_bar(struct sta_info *sta, u8 *addr, u8 tid)
 167 {
 168         struct tid_ampdu_tx *tid_tx;
 169
 170         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 171         if (!tid_tx || !tid_tx->bar_pending)
 172                 return;
 173
 174         tid_tx->bar_pending = false;
 175         ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
 176 }
 177
 178 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 179 {
 180         struct ieee80211_mgmt *mgmt = (void *) skb->data;
 181         struct ieee80211_local *local = sta->local;
 182         struct ieee80211_sub_if_data *sdata = sta->sdata;
 183
 184         if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)
 185                 sta->last_rx = jiffies;
 186
 187         if (ieee80211_is_data_qos(mgmt->frame_control)) {
 188                 struct ieee80211_hdr *hdr = (void *) skb->data;
 189                 u8 *qc = ieee80211_get_qos_ctl(hdr);
 190                 u16 tid = qc[0] & 0xf;
 191
 192                 ieee80211_check_pending_bar(sta, hdr->addr1, tid);
 193         }
 194
 195         if (ieee80211_is_action(mgmt->frame_control) &&
 196             mgmt->u.action.category == WLAN_CATEGORY_HT &&
 197             mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS &&
 198             ieee80211_sdata_running(sdata)) {
 199                 enum ieee80211_smps_mode smps_mode;
 200
 201                 switch (mgmt->u.action.u.ht_smps.smps_control) {
 202                 case WLAN_HT_SMPS_CONTROL_DYNAMIC:
 203                         smps_mode = IEEE80211_SMPS_DYNAMIC;
 204                         break;
 205                 case WLAN_HT_SMPS_CONTROL_STATIC:
 206                         smps_mode = IEEE80211_SMPS_STATIC;
 207                         break;
 208                 case WLAN_HT_SMPS_CONTROL_DISABLED:
 209                 default: /* shouldn't happen since we don't send that */
 210                         smps_mode = IEEE80211_SMPS_OFF;
 211                         break;
 212                 }
 213
 214                 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 215                         /*
 216                          * This update looks racy, but isn't -- if we come
 217                          * here we've definitely got a station that we're
 218                          * talking to, and on a managed interface that can
 219                          * only be the AP. And the only other place updating
 220                          * this variable in managed mode is before association.
 221                          */
 222                         sdata->smps_mode = smps_mode;
 223                         ieee80211_queue_work(&local->hw, &sdata->recalc_smps);
 224                 } else if (sdata->vif.type == NL80211_IFTYPE_AP ||
 225                            sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
 226                         sta->known_smps_mode = smps_mode;
 227                 }
 228         }
 229 }
 230
 231 static void ieee80211_set_bar_pending(struct sta_info *sta, u8 tid, u16 ssn)
 232 {
 233         struct tid_ampdu_tx *tid_tx;
 234
 235         tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]);
 236         if (!tid_tx)
 237                 return;
 238
 239         tid_tx->failed_bar_ssn = ssn;
 240         tid_tx->bar_pending = true;
 241 }
 242
 243 static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
 244 {
 245         int len = sizeof(struct ieee80211_radiotap_header);
 246
 247         /* IEEE80211_RADIOTAP_RATE rate */
 248         if (info->status.rates[0].idx >= 0 &&
 249             !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
 250                                              IEEE80211_TX_RC_VHT_MCS)))
 251                 len += 2;
 252
 253         /* IEEE80211_RADIOTAP_TX_FLAGS */
 254         len += 2;
 255
 256         /* IEEE80211_RADIOTAP_DATA_RETRIES */
 257         len += 1;
 258
 259         /* IEEE80211_RADIOTAP_MCS
 260          * IEEE80211_RADIOTAP_VHT */
 261         if (info->status.rates[0].idx >= 0) {
 262                 if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS)
 263                         len += 3;
 264                 else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS)
 265                         len = ALIGN(len, 2) + 12;
 266         }
 267
 268         return len;
 269 }
 270
 271 static void
 272 ieee80211_add_tx_radiotap_header(struct ieee80211_local *local,
 273                                  struct ieee80211_supported_band *sband,
 274                                  struct sk_buff *skb, int retry_count,
 275                                  int rtap_len, int shift)
 276 {
 277         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 278         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 279         struct ieee80211_radiotap_header *rthdr;
 280         unsigned char *pos;
 281         u16 txflags;
 282
 283         rthdr = (struct ieee80211_radiotap_header *) skb_push(skb, rtap_len);
 284
 285         memset(rthdr, 0, rtap_len);
 286         rthdr->it_len = cpu_to_le16(rtap_len);
 287         rthdr->it_present =
 288                 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
 289                             (1 << IEEE80211_RADIOTAP_DATA_RETRIES));
 290         pos = (unsigned char *)(rthdr + 1);
 291
 292         /*
 293          * XXX: Once radiotap gets the bitmap reset thing the vendor
 294          *      extensions proposal contains, we can actually report
 295          *      the whole set of tries we did.
 296          */
 297
 298         /* IEEE80211_RADIOTAP_RATE */
 299         if (info->status.rates[0].idx >= 0 &&
 300             !(info->status.rates[0].flags & (IEEE80211_TX_RC_MCS |
 301                                              IEEE80211_TX_RC_VHT_MCS))) {
 302                 u16 rate;
 303
 304                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
 305                 rate = sband->bitrates[info->status.rates[0].idx].bitrate;
 306                 *pos = DIV_ROUND_UP(rate, 5 * (1 << shift));
 307                 /* padding for tx flags */
 308                 pos += 2;
 309         }
 310
 311         /* IEEE80211_RADIOTAP_TX_FLAGS */
 312         txflags = 0;
 313         if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
 314             !is_multicast_ether_addr(hdr->addr1))
 315                 txflags |= IEEE80211_RADIOTAP_F_TX_FAIL;
 316
 317         if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
 318             (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
 319                 txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
 320         else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
 321                 txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
 322
 323         put_unaligned_le16(txflags, pos);
 324         pos += 2;
 325
 326         /* IEEE80211_RADIOTAP_DATA_RETRIES */
 327         /* for now report the total retry_count */
 328         *pos = retry_count;
 329         pos++;
 330
 331         if (info->status.rates[0].idx < 0)
 332                 return;
 333
 334         /* IEEE80211_RADIOTAP_MCS
 335          * IEEE80211_RADIOTAP_VHT */
 336         if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
 337                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 338                 pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 339                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 340                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 341                 if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
 342                         pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
 343                 if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 344                         pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
 345                 if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
 346                         pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
 347                 pos[2] = info->status.rates[0].idx;
 348                 pos += 3;
 349         } else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
 350                 u16 known = local->hw.radiotap_vht_details &
 351                         (IEEE80211_RADIOTAP_VHT_KNOWN_GI |
 352                          IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
 353
 354                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
 355
 356                 /* required alignment from rthdr */
 357                 pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
 358
 359                 /* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
 360                 put_unaligned_le16(known, pos);
 361                 pos += 2;
 362
 363                 /* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
 364                 if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
 365                         *pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
 366                 pos++;
 367
 368                 /* u8 bandwidth */
 369                 if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 370                         *pos = 1;
 371                 else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
 372                         *pos = 4;
 373                 else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
 374                         *pos = 11;
 375                 else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
 376                         *pos = 0;
 377                 pos++;
 378
 379                 /* u8 mcs_nss[4] */
 380                 *pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
 381                         ieee80211_rate_get_vht_nss(&info->status.rates[0]);
 382                 pos += 4;
 383
 384                 /* u8 coding */
 385                 pos++;
 386                 /* u8 group_id */
 387                 pos++;
 388                 /* u16 partial_aid */
 389                 pos += 2;
 390         }
 391 }
 392
 393 static void ieee80211_report_used_skb(struct ieee80211_local *local,
 394                                       struct sk_buff *skb, bool dropped)
 395 {
 396         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 397         struct ieee80211_hdr *hdr = (void *)skb->data;
 398         bool acked = info->flags & IEEE80211_TX_STAT_ACK;
 399
 400         if (dropped)
 401                 acked = false;
 402
 403         if (info->flags & (IEEE80211_TX_INTFL_NL80211_FRAME_TX |
 404                            IEEE80211_TX_INTFL_MLME_CONN_TX)) {
 405                 struct ieee80211_sub_if_data *sdata = NULL;
 406                 struct ieee80211_sub_if_data *iter_sdata;
 407                 u64 cookie = (unsigned long)skb;
 408
 409                 rcu_read_lock();
 410
 411                 if (skb->dev) {
 412                         list_for_each_entry_rcu(iter_sdata, &local->interfaces,
 413                                                 list) {
 414                                 if (!iter_sdata->dev)
 415                                         continue;
 416
 417                                 if (skb->dev == iter_sdata->dev) {
 418                                         sdata = iter_sdata;
 419                                         break;
 420                                 }
 421                         }
 422                 } else {
 423                         sdata = rcu_dereference(local->p2p_sdata);
 424                 }
 425
 426                 if (!sdata) {
 427                         skb->dev = NULL;
 428                 } else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
 429                         ieee80211_mgd_conn_tx_status(sdata, hdr->frame_control,
 430                                                      acked);
 431                 } else if (ieee80211_is_nullfunc(hdr->frame_control) ||
 432                            ieee80211_is_qos_nullfunc(hdr->frame_control)) {
 433                         cfg80211_probe_status(sdata->dev, hdr->addr1,
 434                                               cookie, acked, GFP_ATOMIC);
 435                 } else {
 436                         cfg80211_mgmt_tx_status(&sdata->wdev, cookie, skb->data,
 437                                                 skb->len, acked, GFP_ATOMIC);
 438                 }
 439
 440                 rcu_read_unlock();
 441         }
 442
 443         if (unlikely(info->ack_frame_id)) {
 444                 struct sk_buff *ack_skb;
 445                 unsigned long flags;
 446
 447                 spin_lock_irqsave(&local->ack_status_lock, flags);
 448                 ack_skb = idr_find(&local->ack_status_frames,
 449                                    info->ack_frame_id);
 450                 if (ack_skb)
 451                         idr_remove(&local->ack_status_frames,
 452                                    info->ack_frame_id);
 453                 spin_unlock_irqrestore(&local->ack_status_lock, flags);
 454
 455                 if (ack_skb) {
 456                         if (!dropped) {
 457                                 /* consumes ack_skb */
 458                                 skb_complete_wifi_ack(ack_skb, acked);
 459                         } else {
 460                                 dev_kfree_skb_any(ack_skb);
 461                         }
 462                 }
 463         }
 464 }
 465
 466 /*
 467  * Measure Tx frame completion and removal time for Tx latency statistics
 468  * calculation. A single Tx frame latency should be measured from when it
 469  * is entering the Kernel until we receive Tx complete confirmation indication
 470  * and remove the skb.
 471  */
 472 static void ieee80211_tx_latency_end_msrmnt(struct ieee80211_local *local,
 473                                             struct sk_buff *skb,
 474                                             struct sta_info *sta,
 475                                             struct ieee80211_hdr *hdr)
 476 {
 477         ktime_t skb_dprt;
 478         struct timespec dprt_time;
 479         u32 msrmnt;
 480         u16 tid;
 481         u8 *qc;
 482         int i, bin_range_count, bin_count;
 483         u32 *bin_ranges;
 484         __le16 fc;
 485         struct ieee80211_tx_latency_stat *tx_lat;
 486         struct ieee80211_tx_latency_bin_ranges *tx_latency;
 487         ktime_t skb_arv = skb->tstamp;
 488
 489         tx_latency = rcu_dereference(local->tx_latency);
 490
 491         /* assert Tx latency stats are enabled & frame arrived when enabled */
 492         if (!tx_latency || !ktime_to_ns(skb_arv))
 493                 return;
 494
 495         fc = hdr->frame_control;
 496
 497         if (!ieee80211_is_data(fc)) /* make sure it is a data frame */
 498                 return;
 499
 500         /* get frame tid */
 501         if (ieee80211_is_data_qos(hdr->frame_control)) {
 502                 qc = ieee80211_get_qos_ctl(hdr);
 503                 tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
 504         } else {
 505                 tid = 0;
 506         }
 507
 508         tx_lat = &sta->tx_lat[tid];
 509
 510         ktime_get_ts(&dprt_time); /* time stamp completion time */
 511         skb_dprt = ktime_set(dprt_time.tv_sec, dprt_time.tv_nsec);
 512         msrmnt = ktime_to_ms(ktime_sub(skb_dprt, skb_arv));
 513
 514         if (tx_lat->max < msrmnt) /* update stats */
 515                 tx_lat->max = msrmnt;
 516         tx_lat->counter++;
 517         tx_lat->sum += msrmnt;
 518
 519         if (!tx_lat->bins) /* bins not activated */
 520                 return;
 521
 522         /* count how many Tx frames transmitted with the appropriate latency */
 523         bin_range_count = tx_latency->n_ranges;
 524         bin_ranges = tx_latency->ranges;
 525         bin_count = tx_lat->bin_count;
 526
 527         for (i = 0; i < bin_range_count; i++) {
 528                 if (msrmnt <= bin_ranges[i]) {
 529                         tx_lat->bins[i]++;
 530                         break;
 531                 }
 532         }
 533         if (i == bin_range_count) /* msrmnt is bigger than the biggest range */
 534                 tx_lat->bins[i]++;
 535 }
 536
 537 /*
 538  * Use a static threshold for now, best value to be determined
 539  * by testing ...
 540  * Should it depend on:
 541  *  - on # of retransmissions
 542  *  - current throughput (higher value for higher tpt)?
 543  */
 544 #define STA_LOST_PKT_THRESHOLD  50
 545
 546 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 547 {
 548         struct sk_buff *skb2;
 549         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 550         struct ieee80211_local *local = hw_to_local(hw);
 551         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 552         __le16 fc;
 553         struct ieee80211_supported_band *sband;
 554         struct ieee80211_sub_if_data *sdata;
 555         struct net_device *prev_dev = NULL;
 556         struct sta_info *sta, *tmp;
 557         int retry_count = -1, i;
 558         int rates_idx = -1;
 559         bool send_to_cooked;
 560         bool acked;
 561         struct ieee80211_bar *bar;
 562         int rtap_len;
 563         int shift = 0;
 564
 565         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 566                 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 567                     !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
 568                         /* just the first aggr frame carry status info */
 569                         info->status.rates[i].idx = -1;
 570                         info->status.rates[i].count = 0;
 571                         break;
 572                 } else if (info->status.rates[i].idx < 0) {
 573                         break;
 574                 } else if (i >= hw->max_report_rates) {
 575                         /* the HW cannot have attempted that rate */
 576                         info->status.rates[i].idx = -1;
 577                         info->status.rates[i].count = 0;
 578                         break;
 579                 }
 580
 581                 retry_count += info->status.rates[i].count;
 582         }
 583         rates_idx = i - 1;
 584
 585         if (retry_count < 0)
 586                 retry_count = 0;
 587
 588         rcu_read_lock();
 589
 590         sband = local->hw.wiphy->bands[info->band];
 591         fc = hdr->frame_control;
 592
 593         for_each_sta_info(local, hdr->addr1, sta, tmp) {
 594                 /* skip wrong virtual interface */
 595                 if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
 596                         continue;
 597
 598                 shift = ieee80211_vif_get_shift(&sta->sdata->vif);
 599
 600                 if (info->flags & IEEE80211_TX_STATUS_EOSP)
 601                         clear_sta_flag(sta, WLAN_STA_SP);
 602
 603                 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
 604                 if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
 605                         /*
 606                          * The STA is in power save mode, so assume
 607                          * that this TX packet failed because of that.
 608                          */
 609                         ieee80211_handle_filtered_frame(local, sta, skb);
 610                         rcu_read_unlock();
 611                         return;
 612                 }
 613
 614                 /* mesh Peer Service Period support */
 615                 if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
 616                     ieee80211_is_data_qos(fc))
 617                         ieee80211_mpsp_trigger_process(
 618                                         ieee80211_get_qos_ctl(hdr),
 619                                         sta, true, acked);
 620
 621                 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
 622                     (rates_idx != -1))
 623                         sta->last_tx_rate = info->status.rates[rates_idx];
 624
 625                 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
 626                     (ieee80211_is_data_qos(fc))) {
 627                         u16 tid, ssn;
 628                         u8 *qc;
 629
 630                         qc = ieee80211_get_qos_ctl(hdr);
 631                         tid = qc[0] & 0xf;
 632                         ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
 633                                                 & IEEE80211_SCTL_SEQ);
 634                         ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
 635                                            tid, ssn);
 636                 }
 637
 638                 if (!acked && ieee80211_is_back_req(fc)) {
 639                         u16 tid, control;
 640
 641                         /*
 642                          * BAR failed, store the last SSN and retry sending
 643                          * the BAR when the next unicast transmission on the
 644                          * same TID succeeds.
 645                          */
 646                         bar = (struct ieee80211_bar *) skb->data;
 647                         control = le16_to_cpu(bar->control);
 648                         if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
 649                                 u16 ssn = le16_to_cpu(bar->start_seq_num);
 650
 651                                 tid = (control &
 652                                        IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
 653                                       IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
 654
 655                                 ieee80211_set_bar_pending(sta, tid, ssn);
 656                         }
 657                 }
 658
 659                 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
 660                         ieee80211_handle_filtered_frame(local, sta, skb);
 661                         rcu_read_unlock();
 662                         return;
 663                 } else {
 664                         if (!acked)
 665                                 sta->tx_retry_failed++;
 666                         sta->tx_retry_count += retry_count;
 667                 }
 668
 669                 rate_control_tx_status(local, sband, sta, skb);
 670                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 671                         ieee80211s_update_metric(local, sta, skb);
 672
 673                 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
 674                         ieee80211_frame_acked(sta, skb);
 675
 676                 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
 677                     (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
 678                         ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
 679
 680                 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
 681                         if (info->flags & IEEE80211_TX_STAT_ACK) {
 682                                 if (sta->lost_packets)
 683                                         sta->lost_packets = 0;
 684                         } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
 685                                 cfg80211_cqm_pktloss_notify(sta->sdata->dev,
 686                                                             sta->sta.addr,
 687                                                             sta->lost_packets,
 688                                                             GFP_ATOMIC);
 689                                 sta->lost_packets = 0;
 690                         }
 691                 }
 692
 693                 if (acked)
 694                         sta->last_ack_signal = info->status.ack_signal;
 695
 696                 /*
 697                  * Measure frame removal for tx latency
 698                  * statistics calculation
 699                  */
 700                 ieee80211_tx_latency_end_msrmnt(local, skb, sta, hdr);
 701         }
 702
 703         rcu_read_unlock();
 704
 705         ieee80211_led_tx(local);
 706
 707         /* SNMP counters
 708          * Fragments are passed to low-level drivers as separate skbs, so these
 709          * are actually fragments, not frames. Update frame counters only for
 710          * the first fragment of the frame. */
 711         if (info->flags & IEEE80211_TX_STAT_ACK) {
 712                 if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
 713                         local->dot11TransmittedFrameCount++;
 714                         if (is_multicast_ether_addr(hdr->addr1))
 715                                 local->dot11MulticastTransmittedFrameCount++;
 716                         if (retry_count > 0)
 717                                 local->dot11RetryCount++;
 718                         if (retry_count > 1)
 719                                 local->dot11MultipleRetryCount++;
 720                 }
 721
 722                 /* This counter shall be incremented for an acknowledged MPDU
 723                  * with an individual address in the address 1 field or an MPDU
 724                  * with a multicast address in the address 1 field of type Data
 725                  * or Management. */
 726                 if (!is_multicast_ether_addr(hdr->addr1) ||
 727                     ieee80211_is_data(fc) ||
 728                     ieee80211_is_mgmt(fc))
 729                         local->dot11TransmittedFragmentCount++;
 730         } else {
 731                 if (ieee80211_is_first_frag(hdr->seq_ctrl))
 732                         local->dot11FailedCount++;
 733         }
 734
 735         if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
 736             (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
 737             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 738             local->ps_sdata && !(local->scanning)) {
 739                 if (info->flags & IEEE80211_TX_STAT_ACK) {
 740                         local->ps_sdata->u.mgd.flags |=
 741                                         IEEE80211_STA_NULLFUNC_ACKED;
 742                 } else
 743                         mod_timer(&local->dynamic_ps_timer, jiffies +
 744                                         msecs_to_jiffies(10));
 745         }
 746
 747         ieee80211_report_used_skb(local, skb, false);
 748
 749         /* this was a transmitted frame, but now we want to reuse it */
 750         skb_orphan(skb);
 751
 752         /* Need to make a copy before skb->cb gets cleared */
 753         send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
 754                          !(ieee80211_is_data(fc));
 755
 756         /*
 757          * This is a bit racy but we can avoid a lot of work
 758          * with this test...
 759          */
 760         if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
 761                 dev_kfree_skb(skb);
 762                 return;
 763         }
 764
 765         /* send frame to monitor interfaces now */
 766         rtap_len = ieee80211_tx_radiotap_len(info);
 767         if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
 768                 pr_err("ieee80211_tx_status: headroom too small\n");
 769                 dev_kfree_skb(skb);
 770                 return;
 771         }
 772         ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
 773                                          rtap_len, shift);
 774
 775         /* XXX: is this sufficient for BPF? */
 776         skb_set_mac_header(skb, 0);
 777         skb->ip_summed = CHECKSUM_UNNECESSARY;
 778         skb->pkt_type = PACKET_OTHERHOST;
 779         skb->protocol = htons(ETH_P_802_2);
 780         memset(skb->cb, 0, sizeof(skb->cb));
 781
 782         rcu_read_lock();
 783         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 784                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
 785                         if (!ieee80211_sdata_running(sdata))
 786                                 continue;
 787
 788                         if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
 789                             !send_to_cooked)
 790                                 continue;
 791
 792                         if (prev_dev) {
 793                                 skb2 = skb_clone(skb, GFP_ATOMIC);
 794                                 if (skb2) {
 795                                         skb2->dev = prev_dev;
 796                                         netif_rx(skb2);
 797                                 }
 798                         }
 799
 800                         prev_dev = sdata->dev;
 801                 }
 802         }
 803         if (prev_dev) {
 804                 skb->dev = prev_dev;
 805                 netif_rx(skb);
 806                 skb = NULL;
 807         }
 808         rcu_read_unlock();
 809         dev_kfree_skb(skb);
 810 }
 811 EXPORT_SYMBOL(ieee80211_tx_status);
 812
 813 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
 814 {
 815         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 816         cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
 817                                     num_packets, GFP_ATOMIC);
 818 }
 819 EXPORT_SYMBOL(ieee80211_report_low_ack);
 820
 821 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
 822 {
 823         struct ieee80211_local *local = hw_to_local(hw);
 824
 825         ieee80211_report_used_skb(local, skb, true);
 826         dev_kfree_skb_any(skb);
 827 }
 828 EXPORT_SYMBOL(ieee80211_free_txskb);
 829
 830 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
 831                               struct sk_buff_head *skbs)
 832 {
 833         struct sk_buff *skb;
 834
 835         while ((skb = __skb_dequeue(skbs)))
 836                 ieee80211_free_txskb(hw, skb);
 837 }