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 <net/mac80211.h>
  13 #include "ieee80211_i.h"
  14 #include "rate.h"
  15 #include "mesh.h"
  16 #include "led.h"
  17
  18
  19 void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
  20                                  struct sk_buff *skb)
  21 {
  22         struct ieee80211_local *local = hw_to_local(hw);
  23         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  24         int tmp;
  25
  26         skb->pkt_type = IEEE80211_TX_STATUS_MSG;
  27         skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
  28                        &local->skb_queue : &local->skb_queue_unreliable, skb);
  29         tmp = skb_queue_len(&local->skb_queue) +
  30                 skb_queue_len(&local->skb_queue_unreliable);
  31         while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
  32                (skb = skb_dequeue(&local->skb_queue_unreliable))) {
  33                 dev_kfree_skb_irq(skb);
  34                 tmp--;
  35                 I802_DEBUG_INC(local->tx_status_drop);
  36         }
  37         tasklet_schedule(&local->tasklet);
  38 }
  39 EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
  40
  41 static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
  42                                             struct sta_info *sta,
  43                                             struct sk_buff *skb)
  44 {
  45         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
  46
  47         /*
  48          * This skb 'survived' a round-trip through the driver, and
  49          * hopefully the driver didn't mangle it too badly. However,
  50          * we can definitely not rely on the the control information
  51          * being correct. Clear it so we don't get junk there, and
  52          * indicate that it needs new processing, but must not be
  53          * modified/encrypted again.
  54          */
  55         memset(&info->control, 0, sizeof(info->control));
  56
  57         info->control.jiffies = jiffies;
  58         info->control.vif = &sta->sdata->vif;
  59         info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
  60                        IEEE80211_TX_INTFL_RETRANSMISSION;
  61
  62         sta->tx_filtered_count++;
  63
  64         /*
  65          * Clear the TX filter mask for this STA when sending the next
  66          * packet. If the STA went to power save mode, this will happen
  67          * when it wakes up for the next time.
  68          */
  69         set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);
  70
  71         /*
  72          * This code races in the following way:
  73          *
  74          *  (1) STA sends frame indicating it will go to sleep and does so
  75          *  (2) hardware/firmware adds STA to filter list, passes frame up
  76          *  (3) hardware/firmware processes TX fifo and suppresses a frame
  77          *  (4) we get TX status before having processed the frame and
  78          *      knowing that the STA has gone to sleep.
  79          *
  80          * This is actually quite unlikely even when both those events are
  81          * processed from interrupts coming in quickly after one another or
  82          * even at the same time because we queue both TX status events and
  83          * RX frames to be processed by a tasklet and process them in the
  84          * same order that they were received or TX status last. Hence, there
  85          * is no race as long as the frame RX is processed before the next TX
  86          * status, which drivers can ensure, see below.
  87          *
  88          * Note that this can only happen if the hardware or firmware can
  89          * actually add STAs to the filter list, if this is done by the
  90          * driver in response to set_tim() (which will only reduce the race
  91          * this whole filtering tries to solve, not completely solve it)
  92          * this situation cannot happen.
  93          *
  94          * To completely solve this race drivers need to make sure that they
  95          *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
  96          *      functions and
  97          *  (b) always process RX events before TX status events if ordering
  98          *      can be unknown, for example with different interrupt status
  99          *      bits.
 100          */
 101         if (test_sta_flags(sta, WLAN_STA_PS_STA) &&
 102             skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
 103                 skb_queue_tail(&sta->tx_filtered, skb);
 104                 return;
 105         }
 106
 107         if (!test_sta_flags(sta, WLAN_STA_PS_STA) &&
 108             !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
 109                 /* Software retry the packet once */
 110                 info->flags |= IEEE80211_TX_INTFL_RETRIED;
 111                 ieee80211_add_pending_skb(local, skb);
 112                 return;
 113         }
 114
 115 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 116         if (net_ratelimit())
 117                 printk(KERN_DEBUG "%s: dropped TX filtered frame, "
 118                        "queue_len=%d PS=%d @%lu\n",
 119                        wiphy_name(local->hw.wiphy),
 120                        skb_queue_len(&sta->tx_filtered),
 121                        !!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies);
 122 #endif
 123         dev_kfree_skb(skb);
 124 }
 125
 126 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
 127 {
 128         struct ieee80211_mgmt *mgmt = (void *) skb->data;
 129         struct ieee80211_local *local = sta->local;
 130         struct ieee80211_sub_if_data *sdata = sta->sdata;
 131
 132         if (ieee80211_is_action(mgmt->frame_control) &&
 133             sdata->vif.type == NL80211_IFTYPE_STATION &&
 134             mgmt->u.action.category == WLAN_CATEGORY_HT &&
 135             mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
 136                 /*
 137                  * This update looks racy, but isn't -- if we come
 138                  * here we've definitely got a station that we're
 139                  * talking to, and on a managed interface that can
 140                  * only be the AP. And the only other place updating
 141                  * this variable is before we're associated.
 142                  */
 143                 switch (mgmt->u.action.u.ht_smps.smps_control) {
 144                 case WLAN_HT_SMPS_CONTROL_DYNAMIC:
 145                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
 146                         break;
 147                 case WLAN_HT_SMPS_CONTROL_STATIC:
 148                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
 149                         break;
 150                 case WLAN_HT_SMPS_CONTROL_DISABLED:
 151                 default: /* shouldn't happen since we don't send that */
 152                         sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
 153                         break;
 154                 }
 155
 156                 ieee80211_queue_work(&local->hw, &local->recalc_smps);
 157         }
 158 }
 159
 160 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 161 {
 162         struct sk_buff *skb2;
 163         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 164         struct ieee80211_local *local = hw_to_local(hw);
 165         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 166         u16 frag, type;
 167         __le16 fc;
 168         struct ieee80211_supported_band *sband;
 169         struct ieee80211_tx_status_rtap_hdr *rthdr;
 170         struct ieee80211_sub_if_data *sdata;
 171         struct net_device *prev_dev = NULL;
 172         struct sta_info *sta, *tmp;
 173         int retry_count = -1, i;
 174         int rates_idx = -1;
 175         bool send_to_cooked;
 176
 177         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 178                 /* the HW cannot have attempted that rate */
 179                 if (i >= hw->max_rates) {
 180                         info->status.rates[i].idx = -1;
 181                         info->status.rates[i].count = 0;
 182                 } else if (info->status.rates[i].idx >= 0) {
 183                         rates_idx = i;
 184                 }
 185
 186                 retry_count += info->status.rates[i].count;
 187         }
 188         if (retry_count < 0)
 189                 retry_count = 0;
 190
 191         rcu_read_lock();
 192
 193         sband = local->hw.wiphy->bands[info->band];
 194         fc = hdr->frame_control;
 195
 196         for_each_sta_info(local, hdr->addr1, sta, tmp) {
 197                 /* skip wrong virtual interface */
 198                 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN))
 199                         continue;
 200
 201                 if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
 202                     test_sta_flags(sta, WLAN_STA_PS_STA)) {
 203                         /*
 204                          * The STA is in power save mode, so assume
 205                          * that this TX packet failed because of that.
 206                          */
 207                         ieee80211_handle_filtered_frame(local, sta, skb);
 208                         rcu_read_unlock();
 209                         return;
 210                 }
 211
 212                 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
 213                     (rates_idx != -1))
 214                         sta->last_tx_rate = info->status.rates[rates_idx];
 215
 216                 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
 217                     (ieee80211_is_data_qos(fc))) {
 218                         u16 tid, ssn;
 219                         u8 *qc;
 220
 221                         qc = ieee80211_get_qos_ctl(hdr);
 222                         tid = qc[0] & 0xf;
 223                         ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
 224                                                 & IEEE80211_SCTL_SEQ);
 225                         ieee80211_send_bar(sta->sdata, hdr->addr1,
 226                                            tid, ssn);
 227                 }
 228
 229                 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
 230                         ieee80211_handle_filtered_frame(local, sta, skb);
 231                         rcu_read_unlock();
 232                         return;
 233                 } else {
 234                         if (!(info->flags & IEEE80211_TX_STAT_ACK))
 235                                 sta->tx_retry_failed++;
 236                         sta->tx_retry_count += retry_count;
 237                 }
 238
 239                 rate_control_tx_status(local, sband, sta, skb);
 240                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 241                         ieee80211s_update_metric(local, sta, skb);
 242
 243                 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 244                     (info->flags & IEEE80211_TX_STAT_ACK))
 245                         ieee80211_frame_acked(sta, skb);
 246         }
 247
 248         rcu_read_unlock();
 249
 250         ieee80211_led_tx(local, 0);
 251
 252         /* SNMP counters
 253          * Fragments are passed to low-level drivers as separate skbs, so these
 254          * are actually fragments, not frames. Update frame counters only for
 255          * the first fragment of the frame. */
 256
 257         frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
 258         type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;
 259
 260         if (info->flags & IEEE80211_TX_STAT_ACK) {
 261                 if (frag == 0) {
 262                         local->dot11TransmittedFrameCount++;
 263                         if (is_multicast_ether_addr(hdr->addr1))
 264                                 local->dot11MulticastTransmittedFrameCount++;
 265                         if (retry_count > 0)
 266                                 local->dot11RetryCount++;
 267                         if (retry_count > 1)
 268                                 local->dot11MultipleRetryCount++;
 269                 }
 270
 271                 /* This counter shall be incremented for an acknowledged MPDU
 272                  * with an individual address in the address 1 field or an MPDU
 273                  * with a multicast address in the address 1 field of type Data
 274                  * or Management. */
 275                 if (!is_multicast_ether_addr(hdr->addr1) ||
 276                     type == IEEE80211_FTYPE_DATA ||
 277                     type == IEEE80211_FTYPE_MGMT)
 278                         local->dot11TransmittedFragmentCount++;
 279         } else {
 280                 if (frag == 0)
 281                         local->dot11FailedCount++;
 282         }
 283
 284         if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
 285             (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
 286             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 287             local->ps_sdata && !(local->scanning)) {
 288                 if (info->flags & IEEE80211_TX_STAT_ACK) {
 289                         local->ps_sdata->u.mgd.flags |=
 290                                         IEEE80211_STA_NULLFUNC_ACKED;
 291                         ieee80211_queue_work(&local->hw,
 292                                         &local->dynamic_ps_enable_work);
 293                 } else
 294                         mod_timer(&local->dynamic_ps_timer, jiffies +
 295                                         msecs_to_jiffies(10));
 296         }
 297
 298         if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX)
 299                 cfg80211_action_tx_status(
 300                         skb->dev, (unsigned long) skb, skb->data, skb->len,
 301                         !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC);
 302
 303         /* this was a transmitted frame, but now we want to reuse it */
 304         skb_orphan(skb);
 305
 306         /* Need to make a copy before skb->cb gets cleared */
 307         send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
 308                         (type != IEEE80211_FTYPE_DATA);
 309
 310         /*
 311          * This is a bit racy but we can avoid a lot of work
 312          * with this test...
 313          */
 314         if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
 315                 dev_kfree_skb(skb);
 316                 return;
 317         }
 318
 319         /* send frame to monitor interfaces now */
 320
 321         if (skb_headroom(skb) < sizeof(*rthdr)) {
 322                 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
 323                 dev_kfree_skb(skb);
 324                 return;
 325         }
 326
 327         rthdr = (struct ieee80211_tx_status_rtap_hdr *)
 328                                 skb_push(skb, sizeof(*rthdr));
 329
 330         memset(rthdr, 0, sizeof(*rthdr));
 331         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
 332         rthdr->hdr.it_present =
 333                 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
 334                             (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
 335                             (1 << IEEE80211_RADIOTAP_RATE));
 336
 337         if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
 338             !is_multicast_ether_addr(hdr->addr1))
 339                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);
 340
 341         /*
 342          * XXX: Once radiotap gets the bitmap reset thing the vendor
 343          *      extensions proposal contains, we can actually report
 344          *      the whole set of tries we did.
 345          */
 346         if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
 347             (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
 348                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
 349         else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
 350                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
 351         if (info->status.rates[0].idx >= 0 &&
 352             !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
 353                 rthdr->rate = sband->bitrates[
 354                                 info->status.rates[0].idx].bitrate / 5;
 355
 356         /* for now report the total retry_count */
 357         rthdr->data_retries = retry_count;
 358
 359         /* XXX: is this sufficient for BPF? */
 360         skb_set_mac_header(skb, 0);
 361         skb->ip_summed = CHECKSUM_UNNECESSARY;
 362         skb->pkt_type = PACKET_OTHERHOST;
 363         skb->protocol = htons(ETH_P_802_2);
 364         memset(skb->cb, 0, sizeof(skb->cb));
 365
 366         rcu_read_lock();
 367         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 368                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
 369                         if (!ieee80211_sdata_running(sdata))
 370                                 continue;
 371
 372                         if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
 373                             !send_to_cooked)
 374                                 continue;
 375
 376                         if (prev_dev) {
 377                                 skb2 = skb_clone(skb, GFP_ATOMIC);
 378                                 if (skb2) {
 379                                         skb2->dev = prev_dev;
 380                                         netif_rx(skb2);
 381                                 }
 382                         }
 383
 384                         prev_dev = sdata->dev;
 385                 }
 386         }
 387         if (prev_dev) {
 388                 skb->dev = prev_dev;
 389                 netif_rx(skb);
 390                 skb = NULL;
 391         }
 392         rcu_read_unlock();
 393         dev_kfree_skb(skb);
 394 }
 395 EXPORT_SYMBOL(ieee80211_tx_status);