071ac95c4aa0faf64a3dcfb1c054d60b2af958fb
[linux-2.6.git] / 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 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         info->flags &= ~IEEE80211_TX_TEMPORARY_FLAGS;
62
63         sta->tx_filtered_count++;
64
65         /*
66          * Clear the TX filter mask for this STA when sending the next
67          * packet. If the STA went to power save mode, this will happen
68          * when it wakes up for the next time.
69          */
70         set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);
71
72         /*
73          * This code races in the following way:
74          *
75          *  (1) STA sends frame indicating it will go to sleep and does so
76          *  (2) hardware/firmware adds STA to filter list, passes frame up
77          *  (3) hardware/firmware processes TX fifo and suppresses a frame
78          *  (4) we get TX status before having processed the frame and
79          *      knowing that the STA has gone to sleep.
80          *
81          * This is actually quite unlikely even when both those events are
82          * processed from interrupts coming in quickly after one another or
83          * even at the same time because we queue both TX status events and
84          * RX frames to be processed by a tasklet and process them in the
85          * same order that they were received or TX status last. Hence, there
86          * is no race as long as the frame RX is processed before the next TX
87          * status, which drivers can ensure, see below.
88          *
89          * Note that this can only happen if the hardware or firmware can
90          * actually add STAs to the filter list, if this is done by the
91          * driver in response to set_tim() (which will only reduce the race
92          * this whole filtering tries to solve, not completely solve it)
93          * this situation cannot happen.
94          *
95          * To completely solve this race drivers need to make sure that they
96          *  (a) don't mix the irq-safe/not irq-safe TX status/RX processing
97          *      functions and
98          *  (b) always process RX events before TX status events if ordering
99          *      can be unknown, for example with different interrupt status
100          *      bits.
101          */
102         if (test_sta_flags(sta, WLAN_STA_PS_STA) &&
103             skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
104                 skb_queue_tail(&sta->tx_filtered, skb);
105                 return;
106         }
107
108         if (!test_sta_flags(sta, WLAN_STA_PS_STA) &&
109             !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
110                 /* Software retry the packet once */
111                 info->flags |= IEEE80211_TX_INTFL_RETRIED;
112                 ieee80211_add_pending_skb(local, skb);
113                 return;
114         }
115
116 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
117         if (net_ratelimit())
118                 wiphy_debug(local->hw.wiphy,
119                             "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
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 /*
161  * Use a static threshold for now, best value to be determined
162  * by testing ...
163  * Should it depend on:
164  *  - on # of retransmissions
165  *  - current throughput (higher value for higher tpt)?
166  */
167 #define STA_LOST_PKT_THRESHOLD  50
168
169 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
170 {
171         struct sk_buff *skb2;
172         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
173         struct ieee80211_local *local = hw_to_local(hw);
174         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
175         u16 frag, type;
176         __le16 fc;
177         struct ieee80211_supported_band *sband;
178         struct ieee80211_tx_status_rtap_hdr *rthdr;
179         struct ieee80211_sub_if_data *sdata;
180         struct net_device *prev_dev = NULL;
181         struct sta_info *sta, *tmp;
182         int retry_count = -1, i;
183         int rates_idx = -1;
184         bool send_to_cooked;
185         bool acked;
186
187         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
188                 /* the HW cannot have attempted that rate */
189                 if (i >= hw->max_report_rates) {
190                         info->status.rates[i].idx = -1;
191                         info->status.rates[i].count = 0;
192                 } else if (info->status.rates[i].idx >= 0) {
193                         rates_idx = i;
194                 }
195
196                 retry_count += info->status.rates[i].count;
197         }
198         if (retry_count < 0)
199                 retry_count = 0;
200
201         rcu_read_lock();
202
203         sband = local->hw.wiphy->bands[info->band];
204         fc = hdr->frame_control;
205
206         for_each_sta_info(local, hdr->addr1, sta, tmp) {
207                 /* skip wrong virtual interface */
208                 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN))
209                         continue;
210
211                 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
212                 if (!acked && test_sta_flags(sta, WLAN_STA_PS_STA)) {
213                         /*
214                          * The STA is in power save mode, so assume
215                          * that this TX packet failed because of that.
216                          */
217                         ieee80211_handle_filtered_frame(local, sta, skb);
218                         rcu_read_unlock();
219                         return;
220                 }
221
222                 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
223                     (rates_idx != -1))
224                         sta->last_tx_rate = info->status.rates[rates_idx];
225
226                 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
227                     (ieee80211_is_data_qos(fc))) {
228                         u16 tid, ssn;
229                         u8 *qc;
230
231                         qc = ieee80211_get_qos_ctl(hdr);
232                         tid = qc[0] & 0xf;
233                         ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
234                                                 & IEEE80211_SCTL_SEQ);
235                         ieee80211_send_bar(sta->sdata, hdr->addr1,
236                                            tid, ssn);
237                 }
238
239                 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
240                         ieee80211_handle_filtered_frame(local, sta, skb);
241                         rcu_read_unlock();
242                         return;
243                 } else {
244                         if (!acked)
245                                 sta->tx_retry_failed++;
246                         sta->tx_retry_count += retry_count;
247                 }
248
249                 rate_control_tx_status(local, sband, sta, skb);
250                 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
251                         ieee80211s_update_metric(local, sta, skb);
252
253                 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
254                         ieee80211_frame_acked(sta, skb);
255
256                 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
257                     (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
258                         ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
259
260                 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
261                         if (info->flags & IEEE80211_TX_STAT_ACK) {
262                                 if (sta->lost_packets)
263                                         sta->lost_packets = 0;
264                         } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
265                                 cfg80211_cqm_pktloss_notify(sta->sdata->dev,
266                                                             sta->sta.addr,
267                                                             sta->lost_packets,
268                                                             GFP_ATOMIC);
269                                 sta->lost_packets = 0;
270                         }
271                 }
272         }
273
274         rcu_read_unlock();
275
276         ieee80211_led_tx(local, 0);
277
278         /* SNMP counters
279          * Fragments are passed to low-level drivers as separate skbs, so these
280          * are actually fragments, not frames. Update frame counters only for
281          * the first fragment of the frame. */
282
283         frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
284         type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;
285
286         if (info->flags & IEEE80211_TX_STAT_ACK) {
287                 if (frag == 0) {
288                         local->dot11TransmittedFrameCount++;
289                         if (is_multicast_ether_addr(hdr->addr1))
290                                 local->dot11MulticastTransmittedFrameCount++;
291                         if (retry_count > 0)
292                                 local->dot11RetryCount++;
293                         if (retry_count > 1)
294                                 local->dot11MultipleRetryCount++;
295                 }
296
297                 /* This counter shall be incremented for an acknowledged MPDU
298                  * with an individual address in the address 1 field or an MPDU
299                  * with a multicast address in the address 1 field of type Data
300                  * or Management. */
301                 if (!is_multicast_ether_addr(hdr->addr1) ||
302                     type == IEEE80211_FTYPE_DATA ||
303                     type == IEEE80211_FTYPE_MGMT)
304                         local->dot11TransmittedFragmentCount++;
305         } else {
306                 if (frag == 0)
307                         local->dot11FailedCount++;
308         }
309
310         if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
311             (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
312             !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
313             local->ps_sdata && !(local->scanning)) {
314                 if (info->flags & IEEE80211_TX_STAT_ACK) {
315                         local->ps_sdata->u.mgd.flags |=
316                                         IEEE80211_STA_NULLFUNC_ACKED;
317                         ieee80211_queue_work(&local->hw,
318                                         &local->dynamic_ps_enable_work);
319                 } else
320                         mod_timer(&local->dynamic_ps_timer, jiffies +
321                                         msecs_to_jiffies(10));
322         }
323
324         if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
325                 struct ieee80211_work *wk;
326                 u64 cookie = (unsigned long)skb;
327
328                 rcu_read_lock();
329                 list_for_each_entry_rcu(wk, &local->work_list, list) {
330                         if (wk->type != IEEE80211_WORK_OFFCHANNEL_TX)
331                                 continue;
332                         if (wk->offchan_tx.frame != skb)
333                                 continue;
334                         wk->offchan_tx.frame = NULL;
335                         break;
336                 }
337                 rcu_read_unlock();
338                 if (local->hw_roc_skb_for_status == skb) {
339                         cookie = local->hw_roc_cookie ^ 2;
340                         local->hw_roc_skb_for_status = NULL;
341                 }
342                 cfg80211_mgmt_tx_status(
343                         skb->dev, cookie, skb->data, skb->len,
344                         !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC);
345         }
346
347         /* this was a transmitted frame, but now we want to reuse it */
348         skb_orphan(skb);
349
350         /* Need to make a copy before skb->cb gets cleared */
351         send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
352                         (type != IEEE80211_FTYPE_DATA);
353
354         /*
355          * This is a bit racy but we can avoid a lot of work
356          * with this test...
357          */
358         if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
359                 dev_kfree_skb(skb);
360                 return;
361         }
362
363         /* send frame to monitor interfaces now */
364
365         if (skb_headroom(skb) < sizeof(*rthdr)) {
366                 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
367                 dev_kfree_skb(skb);
368                 return;
369         }
370
371         rthdr = (struct ieee80211_tx_status_rtap_hdr *)
372                                 skb_push(skb, sizeof(*rthdr));
373
374         memset(rthdr, 0, sizeof(*rthdr));
375         rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
376         rthdr->hdr.it_present =
377                 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
378                             (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
379                             (1 << IEEE80211_RADIOTAP_RATE));
380
381         if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
382             !is_multicast_ether_addr(hdr->addr1))
383                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);
384
385         /*
386          * XXX: Once radiotap gets the bitmap reset thing the vendor
387          *      extensions proposal contains, we can actually report
388          *      the whole set of tries we did.
389          */
390         if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
391             (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
392                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
393         else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
394                 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
395         if (info->status.rates[0].idx >= 0 &&
396             !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
397                 rthdr->rate = sband->bitrates[
398                                 info->status.rates[0].idx].bitrate / 5;
399
400         /* for now report the total retry_count */
401         rthdr->data_retries = retry_count;
402
403         /* XXX: is this sufficient for BPF? */
404         skb_set_mac_header(skb, 0);
405         skb->ip_summed = CHECKSUM_UNNECESSARY;
406         skb->pkt_type = PACKET_OTHERHOST;
407         skb->protocol = htons(ETH_P_802_2);
408         memset(skb->cb, 0, sizeof(skb->cb));
409
410         rcu_read_lock();
411         list_for_each_entry_rcu(sdata, &local->interfaces, list) {
412                 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
413                         if (!ieee80211_sdata_running(sdata))
414                                 continue;
415
416                         if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
417                             !send_to_cooked)
418                                 continue;
419
420                         if (prev_dev) {
421                                 skb2 = skb_clone(skb, GFP_ATOMIC);
422                                 if (skb2) {
423                                         skb2->dev = prev_dev;
424                                         netif_rx(skb2);
425                                 }
426                         }
427
428                         prev_dev = sdata->dev;
429                 }
430         }
431         if (prev_dev) {
432                 skb->dev = prev_dev;
433                 netif_rx(skb);
434                 skb = NULL;
435         }
436         rcu_read_unlock();
437         dev_kfree_skb(skb);
438 }
439 EXPORT_SYMBOL(ieee80211_tx_status);