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  * Copyright 2013-2014  Intel Mobile Communications GmbH
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/export.h>
  14 #include <linux/etherdevice.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 (ieee80211_hw_check(&local->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_CTS_PROTECT)
 318                 txflags |= IEEE80211_RADIOTAP_F_TX_CTS;
 319         if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
 320                 txflags |= IEEE80211_RADIOTAP_F_TX_RTS;
 321
 322         put_unaligned_le16(txflags, pos);
 323         pos += 2;
 324
 325         /* IEEE80211_RADIOTAP_DATA_RETRIES */
 326         /* for now report the total retry_count */
 327         *pos = retry_count;
 328         pos++;
 329
 330         if (info->status.rates[0].idx < 0)
 331                 return;
 332
 333         /* IEEE80211_RADIOTAP_MCS
 334          * IEEE80211_RADIOTAP_VHT */
 335         if (info->status.rates[0].flags & IEEE80211_TX_RC_MCS) {
 336                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
 337                 pos[0] = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
 338                          IEEE80211_RADIOTAP_MCS_HAVE_GI |
 339                          IEEE80211_RADIOTAP_MCS_HAVE_BW;
 340                 if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
 341                         pos[1] |= IEEE80211_RADIOTAP_MCS_SGI;
 342                 if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 343                         pos[1] |= IEEE80211_RADIOTAP_MCS_BW_40;
 344                 if (info->status.rates[0].flags & IEEE80211_TX_RC_GREEN_FIELD)
 345                         pos[1] |= IEEE80211_RADIOTAP_MCS_FMT_GF;
 346                 pos[2] = info->status.rates[0].idx;
 347                 pos += 3;
 348         } else if (info->status.rates[0].flags & IEEE80211_TX_RC_VHT_MCS) {
 349                 u16 known = local->hw.radiotap_vht_details &
 350                         (IEEE80211_RADIOTAP_VHT_KNOWN_GI |
 351                          IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH);
 352
 353                 rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
 354
 355                 /* required alignment from rthdr */
 356                 pos = (u8 *)rthdr + ALIGN(pos - (u8 *)rthdr, 2);
 357
 358                 /* u16 known - IEEE80211_RADIOTAP_VHT_KNOWN_* */
 359                 put_unaligned_le16(known, pos);
 360                 pos += 2;
 361
 362                 /* u8 flags - IEEE80211_RADIOTAP_VHT_FLAG_* */
 363                 if (info->status.rates[0].flags & IEEE80211_TX_RC_SHORT_GI)
 364                         *pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
 365                 pos++;
 366
 367                 /* u8 bandwidth */
 368                 if (info->status.rates[0].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
 369                         *pos = 1;
 370                 else if (info->status.rates[0].flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
 371                         *pos = 4;
 372                 else if (info->status.rates[0].flags & IEEE80211_TX_RC_160_MHZ_WIDTH)
 373                         *pos = 11;
 374                 else /* IEEE80211_TX_RC_{20_MHZ_WIDTH,FIXME:DUP_DATA} */
 375                         *pos = 0;
 376                 pos++;
 377
 378                 /* u8 mcs_nss[4] */
 379                 *pos = (ieee80211_rate_get_vht_mcs(&info->status.rates[0]) << 4) |
 380                         ieee80211_rate_get_vht_nss(&info->status.rates[0]);
 381                 pos += 4;
 382
 383                 /* u8 coding */
 384                 pos++;
 385                 /* u8 group_id */
 386                 pos++;
 387                 /* u16 partial_aid */
 388                 pos += 2;
 389         }
 390 }
 391
 392 /*
 393  * Handles the tx for TDLS teardown frames.
 394  * If the frame wasn't ACKed by the peer - it will be re-sent through the AP
 395  */
 396 static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local,
 397                                         struct ieee80211_sub_if_data *sdata,
 398                                         struct sk_buff *skb, u32 flags)
 399 {
 400         struct sk_buff *teardown_skb;
 401         struct sk_buff *orig_teardown_skb;
 402         bool is_teardown = false;
 403
 404         /* Get the teardown data we need and free the lock */
 405         spin_lock(&sdata->u.mgd.teardown_lock);
 406         teardown_skb = sdata->u.mgd.teardown_skb;
 407         orig_teardown_skb = sdata->u.mgd.orig_teardown_skb;
 408         if ((skb == orig_teardown_skb) && teardown_skb) {
 409                 sdata->u.mgd.teardown_skb = NULL;
 410                 sdata->u.mgd.orig_teardown_skb = NULL;
 411                 is_teardown = true;
 412         }
 413         spin_unlock(&sdata->u.mgd.teardown_lock);
 414
 415         if (is_teardown) {
 416                 /* This mechanism relies on being able to get ACKs */
 417                 WARN_ON(!ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS));
 418
 419                 /* Check if peer has ACKed */
 420                 if (flags & IEEE80211_TX_STAT_ACK) {
 421                         dev_kfree_skb_any(teardown_skb);
 422                 } else {
 423                         tdls_dbg(sdata,
 424                                  "TDLS Resending teardown through AP\n");
 425
 426                         ieee80211_subif_start_xmit(teardown_skb, skb->dev);
 427                 }
 428         }
 429 }
 430
 431 static struct ieee80211_sub_if_data *
 432 ieee80211_sdata_from_skb(struct ieee80211_local *local, struct sk_buff *skb)
 433 {
 434         struct ieee80211_sub_if_data *sdata;
 435
 436         if (skb->dev) {
 437                 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 438                         if (!sdata->dev)
 439                                 continue;
 440
 441                         if (skb->dev == sdata->dev)
 442                                 return sdata;
 443                 }
 444
 445                 return NULL;
 446         }
 447
 448         return rcu_dereference(local->p2p_sdata);
 449 }
 450
 451 static void ieee80211_report_ack_skb(struct ieee80211_local *local,
 452                                      struct ieee80211_tx_info *info,
 453                                      bool acked, bool dropped)
 454 {
 455         struct sk_buff *skb;
 456         unsigned long flags;
 457
 458         spin_lock_irqsave(&local->ack_status_lock, flags);
 459         skb = idr_find(&local->ack_status_frames, info->ack_frame_id);
 460         if (skb)
 461                 idr_remove(&local->ack_status_frames, info->ack_frame_id);
 462         spin_unlock_irqrestore(&local->ack_status_lock, flags);
 463
 464         if (!skb)
 465                 return;
 466
 467         if (dropped) {
 468                 dev_kfree_skb_any(skb);
 469                 return;
 470         }
 471
 472         if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
 473                 u64 cookie = IEEE80211_SKB_CB(skb)->ack.cookie;
 474                 struct ieee80211_sub_if_data *sdata;
 475                 struct ieee80211_hdr *hdr = (void *)skb->data;
 476
 477                 rcu_read_lock();
 478                 sdata = ieee80211_sdata_from_skb(local, skb);
 479                 if (sdata) {
 480                         if (ieee80211_is_nullfunc(hdr->frame_control) ||
 481                             ieee80211_is_qos_nullfunc(hdr->frame_control))
 482                                 cfg80211_probe_status(sdata->dev, hdr->addr1,
 483                                                       cookie, acked,
 484                                                       GFP_ATOMIC);
 485                         else
 486                                 cfg80211_mgmt_tx_status(&sdata->wdev, cookie,
 487                                                         skb->data, skb->len,
 488                                                         acked, GFP_ATOMIC);
 489                 }
 490                 rcu_read_unlock();
 491
 492                 dev_kfree_skb_any(skb);
 493         } else {
 494                 /* consumes skb */
 495                 skb_complete_wifi_ack(skb, acked);
 496         }
 497 }
 498
 499 static void ieee80211_report_used_skb(struct ieee80211_local *local,
 500                                       struct sk_buff *skb, bool dropped)
 501 {
 502         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 503         struct ieee80211_hdr *hdr = (void *)skb->data;
 504         bool acked = info->flags & IEEE80211_TX_STAT_ACK;
 505
 506         if (dropped)
 507                 acked = false;
 508
 509         if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) {
 510                 struct ieee80211_sub_if_data *sdata;
 511
 512                 rcu_read_lock();
 513
 514                 sdata = ieee80211_sdata_from_skb(local, skb);
 515
 516                 if (!sdata) {
 517                         skb->dev = NULL;
 518                 } else {
 519                         unsigned int hdr_size =
 520                                 ieee80211_hdrlen(hdr->frame_control);
 521
 522                         /* Check to see if packet is a TDLS teardown packet */
 523                         if (ieee80211_is_data(hdr->frame_control) &&
 524                             (ieee80211_get_tdls_action(skb, hdr_size) ==
 525                              WLAN_TDLS_TEARDOWN))
 526                                 ieee80211_tdls_td_tx_handle(local, sdata, skb,
 527                                                             info->flags);
 528                         else
 529                                 ieee80211_mgd_conn_tx_status(sdata,
 530                                                              hdr->frame_control,
 531                                                              acked);
 532                 }
 533
 534                 rcu_read_unlock();
 535         } else if (info->ack_frame_id) {
 536                 ieee80211_report_ack_skb(local, info, acked, dropped);
 537         }
 538 }
 539
 540 /*
 541  * Use a static threshold for now, best value to be determined
 542  * by testing ...
 543  * Should it depend on:
 544  *  - on # of retransmissions
 545  *  - current throughput (higher value for higher tpt)?
 546  */
 547 #define STA_LOST_PKT_THRESHOLD  50
 548 #define STA_LOST_TDLS_PKT_THRESHOLD     10
 549 #define STA_LOST_TDLS_PKT_TIME          (10*HZ) /* 10secs since last ACK */
 550
 551 static void ieee80211_lost_packet(struct sta_info *sta,
 552                                   struct ieee80211_tx_info *info)
 553 {
 554         /* This packet was aggregated but doesn't carry status info */
 555         if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 556             !(info->flags & IEEE80211_TX_STAT_AMPDU))
 557                 return;
 558
 559         sta->lost_packets++;
 560         if (!sta->sta.tdls && sta->lost_packets < STA_LOST_PKT_THRESHOLD)
 561                 return;
 562
 563         /*
 564          * If we're in TDLS mode, make sure that all STA_LOST_TDLS_PKT_THRESHOLD
 565          * of the last packets were lost, and that no ACK was received in the
 566          * last STA_LOST_TDLS_PKT_TIME ms, before triggering the CQM packet-loss
 567          * mechanism.
 568          */
 569         if (sta->sta.tdls &&
 570             (sta->lost_packets < STA_LOST_TDLS_PKT_THRESHOLD ||
 571              time_before(jiffies,
 572                          sta->last_tdls_pkt_time + STA_LOST_TDLS_PKT_TIME)))
 573                 return;
 574
 575         cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
 576                                     sta->lost_packets, GFP_ATOMIC);
 577         sta->lost_packets = 0;
 578 }
 579
 580 static int ieee80211_tx_get_rates(struct ieee80211_hw *hw,
 581                                   struct ieee80211_tx_info *info,
 582                                   int *retry_count)
 583 {
 584         int rates_idx = -1;
 585         int count = -1;
 586         int i;
 587
 588         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 589                 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
 590                     !(info->flags & IEEE80211_TX_STAT_AMPDU)) {
 591                         /* just the first aggr frame carry status info */
 592                         info->status.rates[i].idx = -1;
 593                         info->status.rates[i].count = 0;
 594                         break;
 595                 } else if (info->status.rates[i].idx < 0) {
 596                         break;
 597                 } else if (i >= hw->max_report_rates) {
 598                         /* the HW cannot have attempted that rate */
 599                         info->status.rates[i].idx = -1;
 600                         info->status.rates[i].count = 0;
 601                         break;
 602                 }
 603
 604                 count += info->status.rates[i].count;
 605         }
 606         rates_idx = i - 1;
 607
 608         if (count < 0)
 609                 count = 0;
 610
 611         *retry_count = count;
 612         return rates_idx;
 613 }
 614
 615 void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
 616                                struct ieee80211_sta *pubsta,
 617                                struct ieee80211_tx_info *info)
 618 {
 619         struct ieee80211_local *local = hw_to_local(hw);
 620         struct ieee80211_supported_band *sband;
 621         int retry_count;
 622         int rates_idx;
 623         bool acked, noack_success;
 624
 625         rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
 626
 627         sband = hw->wiphy->bands[info->band];
 628
 629         acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
 630         noack_success = !!(info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED);
 631
 632         if (pubsta) {
 633                 struct sta_info *sta;
 634
 635                 sta = container_of(pubsta, struct sta_info, sta);
 636
 637                 if (!acked)
 638                         sta->tx_retry_failed++;
 639                 sta->tx_retry_count += retry_count;
 640
 641                 if (acked) {
 642                         sta->last_rx = jiffies;
 643
 644                         if (sta->lost_packets)
 645                                 sta->lost_packets = 0;
 646
 647                         /* Track when last TDLS packet was ACKed */
 648                         if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
 649                                 sta->last_tdls_pkt_time = jiffies;
 650                 } else {
 651                         ieee80211_lost_packet(sta, info);
 652                 }
 653
 654                 rate_control_tx_status_noskb(local, sband, sta, info);
 655         }
 656
 657         if (acked || noack_success) {
 658                 I802_DEBUG_INC(local->dot11TransmittedFrameCount);
 659                 if (!pubsta)
 660                         I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
 661                 if (retry_count > 0)
 662                         I802_DEBUG_INC(local->dot11RetryCount);
 663                 if (retry_count > 1)
 664                         I802_DEBUG_INC(local->dot11MultipleRetryCount);
 665         } else {
 666                 I802_DEBUG_INC(local->dot11FailedCount);
 667         }
 668 }
 669 EXPORT_SYMBOL(ieee80211_tx_status_noskb);
 670
 671 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 672 {
 673         struct sk_buff *skb2;
 674         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 675         struct ieee80211_local *local = hw_to_local(hw);
 676         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 677         __le16 fc;
 678         struct ieee80211_supported_band *sband;
 679         struct ieee80211_sub_if_data *sdata;
 680         struct net_device *prev_dev = NULL;
 681         struct sta_info *sta;
 682         struct rhash_head *tmp;
 683         int retry_count;
 684         int rates_idx;
 685         bool send_to_cooked;
 686         bool acked;
 687         struct ieee80211_bar *bar;
 688         int rtap_len;
 689         int shift = 0;
 690         int tid = IEEE80211_NUM_TIDS;
 691         const struct bucket_table *tbl;
 692
 693         rates_idx = ieee80211_tx_get_rates(hw, info, &retry_count);
 694
 695         rcu_read_lock();
 696
 697         sband = local->hw.wiphy->bands[info->band];
 698         fc = hdr->frame_control;
 699
 700         tbl = rht_dereference_rcu(local->sta_hash.tbl, &local->sta_hash);
 701
 702         for_each_sta_info(local, tbl, hdr->addr1, sta, tmp) {
 703                 /* skip wrong virtual interface */
 704                 if (!ether_addr_equal(hdr->addr2, sta->sdata->vif.addr))
 705                         continue;
 706
 707                 shift = ieee80211_vif_get_shift(&sta->sdata->vif);
 708
 709                 if (info->flags & IEEE80211_TX_STATUS_EOSP)
 710                         clear_sta_flag(sta, WLAN_STA_SP);
 711
 712                 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
 713                 if (!acked && test_sta_flag(sta, WLAN_STA_PS_STA)) {
 714                         /*
 715                          * The STA is in power save mode, so assume
 716                          * that this TX packet failed because of that.
 717                          */
 718                         ieee80211_handle_filtered_frame(local, sta, skb);
 719                         rcu_read_unlock();
 720                         return;
 721                 }
 722
 723                 /* mesh Peer Service Period support */
 724                 if (ieee80211_vif_is_mesh(&sta->sdata->vif) &&
 725                     ieee80211_is_data_qos(fc))
 726                         ieee80211_mpsp_trigger_process(
 727                                         ieee80211_get_qos_ctl(hdr),
 728                                         sta, true, acked);
 729
 730                 if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL) &&
 731                     (ieee80211_is_data(hdr->frame_control)) &&
 732                     (rates_idx != -1))
 733                         sta->last_tx_rate = info->status.rates[rates_idx];
 734
 735                 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
 736                     (ieee80211_is_data_qos(fc))) {
 737                         u16 ssn;
 738                         u8 *qc;
 739
 740                         qc = ieee80211_get_qos_ctl(hdr);
 741                         tid = qc[0] & 0xf;
 742                         ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
 743                                                 & IEEE80211_SCTL_SEQ);
 744                         ieee80211_send_bar(&sta->sdata->vif, hdr->addr1,
 745                                            tid, ssn);
 746                 } else if (ieee80211_is_data_qos(fc)) {
 747                         u8 *qc = ieee80211_get_qos_ctl(hdr);
 748
 749                         tid = qc[0] & 0xf;
 750                 }
 751
 752                 if (!acked && ieee80211_is_back_req(fc)) {
 753                         u16 control;
 754
 755                         /*
 756                          * BAR failed, store the last SSN and retry sending
 757                          * the BAR when the next unicast transmission on the
 758                          * same TID succeeds.
 759                          */
 760                         bar = (struct ieee80211_bar *) skb->data;
 761                         control = le16_to_cpu(bar->control);
 762                         if (!(control & IEEE80211_BAR_CTRL_MULTI_TID)) {
 763                                 u16 ssn = le16_to_cpu(bar->start_seq_num);
 764
 765                                 tid = (control &
 766                                        IEEE80211_BAR_CTRL_TID_INFO_MASK) >>
 767                                       IEEE80211_BAR_CTRL_TID_INFO_SHIFT;
 768
 769                                 ieee80211_set_bar_pending(sta, tid, ssn);
 770                         }
 771                 }
 772
 773                 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
 774                         ieee80211_handle_filtered_frame(local, sta, skb);
 775                         rcu_read_unlock();
 776                         return;
 777                 } else {
 778                         if (!acked)
 779                                 sta->tx_retry_failed++;
 780                         sta->tx_retry_count += retry_count;
 781
 782                         if (ieee80211_is_data_present(fc)) {
 783                                 if (!acked)
 784                                         sta->tx_msdu_failed[tid]++;
 785                                 sta->tx_msdu_retries[tid] += retry_count;
 786                         }
 787                 }
 788
 789                 rate_control_tx_status(local, sband, sta, skb);
 790                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 791                         ieee80211s_update_metric(local, sta, skb);
 792
 793                 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
 794                         ieee80211_frame_acked(sta, skb);
 795
 796                 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
 797                     ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS))
 798                         ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data,
 799                                                 acked, info->status.tx_time);
 800
 801                 if (ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS)) {
 802                         if (info->flags & IEEE80211_TX_STAT_ACK) {
 803                                 if (sta->lost_packets)
 804                                         sta->lost_packets = 0;
 805
 806                                 /* Track when last TDLS packet was ACKed */
 807                                 if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
 808                                         sta->last_tdls_pkt_time = jiffies;
 809                         } else {
 810                                 ieee80211_lost_packet(sta, info);
 811                         }
 812                 }
 813
 814                 if (acked)
 815                         sta->last_ack_signal = info->status.ack_signal;
 816         }
 817
 818         rcu_read_unlock();
 819
 820         ieee80211_led_tx(local);
 821
 822         /* SNMP counters
 823          * Fragments are passed to low-level drivers as separate skbs, so these
 824          * are actually fragments, not frames. Update frame counters only for
 825          * the first fragment of the frame. */
 826         if ((info->flags & IEEE80211_TX_STAT_ACK) ||
 827             (info->flags & IEEE80211_TX_STAT_NOACK_TRANSMITTED)) {
 828                 if (ieee80211_is_first_frag(hdr->seq_ctrl)) {
 829                         I802_DEBUG_INC(local->dot11TransmittedFrameCount);
 830                         if (is_multicast_ether_addr(ieee80211_get_DA(hdr)))
 831                                 I802_DEBUG_INC(local->dot11MulticastTransmittedFrameCount);
 832                         if (retry_count > 0)
 833                                 I802_DEBUG_INC(local->dot11RetryCount);
 834                         if (retry_count > 1)
 835                                 I802_DEBUG_INC(local->dot11MultipleRetryCount);
 836                 }
 837
 838                 /* This counter shall be incremented for an acknowledged MPDU
 839                  * with an individual address in the address 1 field or an MPDU
 840                  * with a multicast address in the address 1 field of type Data
 841                  * or Management. */
 842                 if (!is_multicast_ether_addr(hdr->addr1) ||
 843                     ieee80211_is_data(fc) ||
 844                     ieee80211_is_mgmt(fc))
 845                         I802_DEBUG_INC(local->dot11TransmittedFragmentCount);
 846         } else {
 847                 if (ieee80211_is_first_frag(hdr->seq_ctrl))
 848                         I802_DEBUG_INC(local->dot11FailedCount);
 849         }
 850
 851         if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
 852             ieee80211_hw_check(&local->hw, REPORTS_TX_ACK_STATUS) &&
 853             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 854             local->ps_sdata && !(local->scanning)) {
 855                 if (info->flags & IEEE80211_TX_STAT_ACK) {
 856                         local->ps_sdata->u.mgd.flags |=
 857                                         IEEE80211_STA_NULLFUNC_ACKED;
 858                 } else
 859                         mod_timer(&local->dynamic_ps_timer, jiffies +
 860                                         msecs_to_jiffies(10));
 861         }
 862
 863         ieee80211_report_used_skb(local, skb, false);
 864
 865         /* this was a transmitted frame, but now we want to reuse it */
 866         skb_orphan(skb);
 867
 868         /* Need to make a copy before skb->cb gets cleared */
 869         send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
 870                          !(ieee80211_is_data(fc));
 871
 872         /*
 873          * This is a bit racy but we can avoid a lot of work
 874          * with this test...
 875          */
 876         if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
 877                 dev_kfree_skb(skb);
 878                 return;
 879         }
 880
 881         /* send frame to monitor interfaces now */
 882         rtap_len = ieee80211_tx_radiotap_len(info);
 883         if (WARN_ON_ONCE(skb_headroom(skb) < rtap_len)) {
 884                 pr_err("ieee80211_tx_status: headroom too small\n");
 885                 dev_kfree_skb(skb);
 886                 return;
 887         }
 888         ieee80211_add_tx_radiotap_header(local, sband, skb, retry_count,
 889                                          rtap_len, shift);
 890
 891         /* XXX: is this sufficient for BPF? */
 892         skb_set_mac_header(skb, 0);
 893         skb->ip_summed = CHECKSUM_UNNECESSARY;
 894         skb->pkt_type = PACKET_OTHERHOST;
 895         skb->protocol = htons(ETH_P_802_2);
 896         memset(skb->cb, 0, sizeof(skb->cb));
 897
 898         rcu_read_lock();
 899         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 900                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
 901                         if (!ieee80211_sdata_running(sdata))
 902                                 continue;
 903
 904                         if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
 905                             !send_to_cooked)
 906                                 continue;
 907
 908                         if (prev_dev) {
 909                                 skb2 = skb_clone(skb, GFP_ATOMIC);
 910                                 if (skb2) {
 911                                         skb2->dev = prev_dev;
 912                                         netif_rx(skb2);
 913                                 }
 914                         }
 915
 916                         prev_dev = sdata->dev;
 917                 }
 918         }
 919         if (prev_dev) {
 920                 skb->dev = prev_dev;
 921                 netif_rx(skb);
 922                 skb = NULL;
 923         }
 924         rcu_read_unlock();
 925         dev_kfree_skb(skb);
 926 }
 927 EXPORT_SYMBOL(ieee80211_tx_status);
 928
 929 void ieee80211_report_low_ack(struct ieee80211_sta *pubsta, u32 num_packets)
 930 {
 931         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 932         cfg80211_cqm_pktloss_notify(sta->sdata->dev, sta->sta.addr,
 933                                     num_packets, GFP_ATOMIC);
 934 }
 935 EXPORT_SYMBOL(ieee80211_report_low_ack);
 936
 937 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb)
 938 {
 939         struct ieee80211_local *local = hw_to_local(hw);
 940
 941         ieee80211_report_used_skb(local, skb, true);
 942         dev_kfree_skb_any(skb);
 943 }
 944 EXPORT_SYMBOL(ieee80211_free_txskb);
 945
 946 void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
 947                               struct sk_buff_head *skbs)
 948 {
 949         struct sk_buff *skb;
 950
 951         while ((skb = __skb_dequeue(skbs)))
 952                 ieee80211_free_txskb(hw, skb);
 953 }