1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
|
/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2008-2010 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
#include "led.h"
void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
struct sk_buff *skb)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
int tmp;
skb->pkt_type = IEEE80211_TX_STATUS_MSG;
skb_queue_tail(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS ?
&local->skb_queue : &local->skb_queue_unreliable, skb);
tmp = skb_queue_len(&local->skb_queue) +
skb_queue_len(&local->skb_queue_unreliable);
while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
(skb = skb_dequeue(&local->skb_queue_unreliable))) {
dev_kfree_skb_irq(skb);
tmp--;
I802_DEBUG_INC(local->tx_status_drop);
}
tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee80211_tx_status_irqsafe);
static void ieee80211_handle_filtered_frame(struct ieee80211_local *local,
struct sta_info *sta,
struct sk_buff *skb)
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
/*
* This skb 'survived' a round-trip through the driver, and
* hopefully the driver didn't mangle it too badly. However,
* we can definitely not rely on the control information
* being correct. Clear it so we don't get junk there, and
* indicate that it needs new processing, but must not be
* modified/encrypted again.
*/
memset(&info->control, 0, sizeof(info->control));
info->control.jiffies = jiffies;
info->control.vif = &sta->sdata->vif;
info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING |
IEEE80211_TX_INTFL_RETRANSMISSION;
sta->tx_filtered_count++;
/*
* Clear the TX filter mask for this STA when sending the next
* packet. If the STA went to power save mode, this will happen
* when it wakes up for the next time.
*/
set_sta_flags(sta, WLAN_STA_CLEAR_PS_FILT);
/*
* This code races in the following way:
*
* (1) STA sends frame indicating it will go to sleep and does so
* (2) hardware/firmware adds STA to filter list, passes frame up
* (3) hardware/firmware processes TX fifo and suppresses a frame
* (4) we get TX status before having processed the frame and
* knowing that the STA has gone to sleep.
*
* This is actually quite unlikely even when both those events are
* processed from interrupts coming in quickly after one another or
* even at the same time because we queue both TX status events and
* RX frames to be processed by a tasklet and process them in the
* same order that they were received or TX status last. Hence, there
* is no race as long as the frame RX is processed before the next TX
* status, which drivers can ensure, see below.
*
* Note that this can only happen if the hardware or firmware can
* actually add STAs to the filter list, if this is done by the
* driver in response to set_tim() (which will only reduce the race
* this whole filtering tries to solve, not completely solve it)
* this situation cannot happen.
*
* To completely solve this race drivers need to make sure that they
* (a) don't mix the irq-safe/not irq-safe TX status/RX processing
* functions and
* (b) always process RX events before TX status events if ordering
* can be unknown, for example with different interrupt status
* bits.
*/
if (test_sta_flags(sta, WLAN_STA_PS_STA) &&
skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
skb_queue_tail(&sta->tx_filtered, skb);
return;
}
if (!test_sta_flags(sta, WLAN_STA_PS_STA) &&
!(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
/* Software retry the packet once */
info->flags |= IEEE80211_TX_INTFL_RETRIED;
ieee80211_add_pending_skb(local, skb);
return;
}
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
if (net_ratelimit())
printk(KERN_DEBUG "%s: dropped TX filtered frame, "
"queue_len=%d PS=%d @%lu\n",
wiphy_name(local->hw.wiphy),
skb_queue_len(&sta->tx_filtered),
!!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies);
#endif
dev_kfree_skb(skb);
}
static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
{
struct ieee80211_mgmt *mgmt = (void *) skb->data;
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
if (ieee80211_is_action(mgmt->frame_control) &&
sdata->vif.type == NL80211_IFTYPE_STATION &&
mgmt->u.action.category == WLAN_CATEGORY_HT &&
mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
/*
* This update looks racy, but isn't -- if we come
* here we've definitely got a station that we're
* talking to, and on a managed interface that can
* only be the AP. And the only other place updating
* this variable is before we're associated.
*/
switch (mgmt->u.action.u.ht_smps.smps_control) {
case WLAN_HT_SMPS_CONTROL_DYNAMIC:
sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
break;
case WLAN_HT_SMPS_CONTROL_STATIC:
sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
break;
case WLAN_HT_SMPS_CONTROL_DISABLED:
default: /* shouldn't happen since we don't send that */
sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
break;
}
ieee80211_queue_work(&local->hw, &local->recalc_smps);
}
}
void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
{
struct sk_buff *skb2;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
u16 frag, type;
__le16 fc;
struct ieee80211_supported_band *sband;
struct ieee80211_tx_status_rtap_hdr *rthdr;
struct ieee80211_sub_if_data *sdata;
struct net_device *prev_dev = NULL;
struct sta_info *sta, *tmp;
int retry_count = -1, i;
int rates_idx = -1;
bool send_to_cooked;
for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
/* the HW cannot have attempted that rate */
if (i >= hw->max_rates) {
info->status.rates[i].idx = -1;
info->status.rates[i].count = 0;
} else if (info->status.rates[i].idx >= 0) {
rates_idx = i;
}
retry_count += info->status.rates[i].count;
}
if (retry_count < 0)
retry_count = 0;
rcu_read_lock();
sband = local->hw.wiphy->bands[info->band];
fc = hdr->frame_control;
for_each_sta_info(local, hdr->addr1, sta, tmp) {
/* skip wrong virtual interface */
if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN))
continue;
if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
test_sta_flags(sta, WLAN_STA_PS_STA)) {
/*
* The STA is in power save mode, so assume
* that this TX packet failed because of that.
*/
ieee80211_handle_filtered_frame(local, sta, skb);
rcu_read_unlock();
return;
}
if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
(rates_idx != -1))
sta->last_tx_rate = info->status.rates[rates_idx];
if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
(ieee80211_is_data_qos(fc))) {
u16 tid, ssn;
u8 *qc;
qc = ieee80211_get_qos_ctl(hdr);
tid = qc[0] & 0xf;
ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
& IEEE80211_SCTL_SEQ);
ieee80211_send_bar(sta->sdata, hdr->addr1,
tid, ssn);
}
if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
ieee80211_handle_filtered_frame(local, sta, skb);
rcu_read_unlock();
return;
} else {
if (!(info->flags & IEEE80211_TX_STAT_ACK))
sta->tx_retry_failed++;
sta->tx_retry_count += retry_count;
}
rate_control_tx_status(local, sband, sta, skb);
if (ieee80211_vif_is_mesh(&sta->sdata->vif))
ieee80211s_update_metric(local, sta, skb);
if (!(info->flags & IEEE80211_TX_CTL_INJECTED) &&
(info->flags & IEEE80211_TX_STAT_ACK))
ieee80211_frame_acked(sta, skb);
}
rcu_read_unlock();
ieee80211_led_tx(local, 0);
/* SNMP counters
* Fragments are passed to low-level drivers as separate skbs, so these
* are actually fragments, not frames. Update frame counters only for
* the first fragment of the frame. */
frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
type = le16_to_cpu(hdr->frame_control)
|