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
ieee80211_tx_status_irqsafe(struct ieee80211_hw * hw,struct sk_buff * skb)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
ieee80211_handle_filtered_frame(struct ieee80211_local * local,struct sta_info * sta,struct sk_buff * skb)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 * (c) if PS mode transitions are manual (i.e. the flag
102 * %IEEE80211_HW_AP_LINK_PS is set), always process PS state
103 * changes before calling TX status events if ordering can be
104 * unknown.
105 */
106 if (test_sta_flags(sta, WLAN_STA_PS_STA) &&
107 skb_queue_len(&sta->tx_filtered) < STA_MAX_TX_BUFFER) {
108 skb_queue_tail(&sta->tx_filtered, skb);
109 return;
110 }
111
112 if (!test_sta_flags(sta, WLAN_STA_PS_STA) &&
113 !(info->flags & IEEE80211_TX_INTFL_RETRIED)) {
114 /* Software retry the packet once */
115 info->flags |= IEEE80211_TX_INTFL_RETRIED;
116 ieee80211_add_pending_skb(local, skb);
117 return;
118 }
119
120 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
121 if (net_ratelimit())
122 wiphy_debug(local->hw.wiphy,
123 "dropped TX filtered frame, queue_len=%d PS=%d @%lu\n",
124 skb_queue_len(&sta->tx_filtered),
125 !!test_sta_flags(sta, WLAN_STA_PS_STA), jiffies);
126 #endif
127 dev_kfree_skb(skb);
128 }
129
ieee80211_frame_acked(struct sta_info * sta,struct sk_buff * skb)130 static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
131 {
132 struct ieee80211_mgmt *mgmt = (void *) skb->data;
133 struct ieee80211_local *local = sta->local;
134 struct ieee80211_sub_if_data *sdata = sta->sdata;
135
136 if (ieee80211_is_action(mgmt->frame_control) &&
137 sdata->vif.type == NL80211_IFTYPE_STATION &&
138 mgmt->u.action.category == WLAN_CATEGORY_HT &&
139 mgmt->u.action.u.ht_smps.action == WLAN_HT_ACTION_SMPS) {
140 /*
141 * This update looks racy, but isn't -- if we come
142 * here we've definitely got a station that we're
143 * talking to, and on a managed interface that can
144 * only be the AP. And the only other place updating
145 * this variable is before we're associated.
146 */
147 switch (mgmt->u.action.u.ht_smps.smps_control) {
148 case WLAN_HT_SMPS_CONTROL_DYNAMIC:
149 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_DYNAMIC;
150 break;
151 case WLAN_HT_SMPS_CONTROL_STATIC:
152 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_STATIC;
153 break;
154 case WLAN_HT_SMPS_CONTROL_DISABLED:
155 default: /* shouldn't happen since we don't send that */
156 sta->sdata->u.mgd.ap_smps = IEEE80211_SMPS_OFF;
157 break;
158 }
159
160 ieee80211_queue_work(&local->hw, &local->recalc_smps);
161 }
162 }
163
164 /*
165 * Use a static threshold for now, best value to be determined
166 * by testing ...
167 * Should it depend on:
168 * - on # of retransmissions
169 * - current throughput (higher value for higher tpt)?
170 */
171 #define STA_LOST_PKT_THRESHOLD 50
172
ieee80211_tx_status(struct ieee80211_hw * hw,struct sk_buff * skb)173 void ieee80211_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
174 {
175 struct sk_buff *skb2;
176 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
177 struct ieee80211_local *local = hw_to_local(hw);
178 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
179 u16 frag, type;
180 __le16 fc;
181 struct ieee80211_supported_band *sband;
182 struct ieee80211_tx_status_rtap_hdr *rthdr;
183 struct ieee80211_sub_if_data *sdata;
184 struct net_device *prev_dev = NULL;
185 struct sta_info *sta, *tmp;
186 int retry_count = -1, i;
187 int rates_idx = -1;
188 bool send_to_cooked;
189 bool acked;
190
191 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
192 /* the HW cannot have attempted that rate */
193 if (i >= hw->max_report_rates) {
194 info->status.rates[i].idx = -1;
195 info->status.rates[i].count = 0;
196 } else if (info->status.rates[i].idx >= 0) {
197 rates_idx = i;
198 }
199
200 retry_count += info->status.rates[i].count;
201 }
202 if (retry_count < 0)
203 retry_count = 0;
204
205 rcu_read_lock();
206
207 sband = local->hw.wiphy->bands[info->band];
208 fc = hdr->frame_control;
209
210 for_each_sta_info(local, hdr->addr1, sta, tmp) {
211 /* skip wrong virtual interface */
212 if (memcmp(hdr->addr2, sta->sdata->vif.addr, ETH_ALEN))
213 continue;
214
215 acked = !!(info->flags & IEEE80211_TX_STAT_ACK);
216 if (!acked && test_sta_flags(sta, WLAN_STA_PS_STA)) {
217 /*
218 * The STA is in power save mode, so assume
219 * that this TX packet failed because of that.
220 */
221 ieee80211_handle_filtered_frame(local, sta, skb);
222 rcu_read_unlock();
223 return;
224 }
225
226 if ((local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) &&
227 (rates_idx != -1))
228 sta->last_tx_rate = info->status.rates[rates_idx];
229
230 if ((info->flags & IEEE80211_TX_STAT_AMPDU_NO_BACK) &&
231 (ieee80211_is_data_qos(fc))) {
232 u16 tid, ssn;
233 u8 *qc;
234
235 qc = ieee80211_get_qos_ctl(hdr);
236 tid = qc[0] & 0xf;
237 ssn = ((le16_to_cpu(hdr->seq_ctrl) + 0x10)
238 & IEEE80211_SCTL_SEQ);
239 ieee80211_send_bar(sta->sdata, hdr->addr1,
240 tid, ssn);
241 }
242
243 if (info->flags & IEEE80211_TX_STAT_TX_FILTERED) {
244 ieee80211_handle_filtered_frame(local, sta, skb);
245 rcu_read_unlock();
246 return;
247 } else {
248 if (!acked)
249 sta->tx_retry_failed++;
250 sta->tx_retry_count += retry_count;
251 }
252
253 rate_control_tx_status(local, sband, sta, skb);
254 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
255 ieee80211s_update_metric(local, sta, skb);
256
257 if (!(info->flags & IEEE80211_TX_CTL_INJECTED) && acked)
258 ieee80211_frame_acked(sta, skb);
259
260 if ((sta->sdata->vif.type == NL80211_IFTYPE_STATION) &&
261 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS))
262 ieee80211_sta_tx_notify(sta->sdata, (void *) skb->data, acked);
263
264 if (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) {
265 if (info->flags & IEEE80211_TX_STAT_ACK) {
266 if (sta->lost_packets)
267 sta->lost_packets = 0;
268 } else if (++sta->lost_packets >= STA_LOST_PKT_THRESHOLD) {
269 cfg80211_cqm_pktloss_notify(sta->sdata->dev,
270 sta->sta.addr,
271 sta->lost_packets,
272 GFP_ATOMIC);
273 sta->lost_packets = 0;
274 }
275 }
276 }
277
278 rcu_read_unlock();
279
280 ieee80211_led_tx(local, 0);
281
282 /* SNMP counters
283 * Fragments are passed to low-level drivers as separate skbs, so these
284 * are actually fragments, not frames. Update frame counters only for
285 * the first fragment of the frame. */
286
287 frag = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
288 type = le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_FTYPE;
289
290 if (info->flags & IEEE80211_TX_STAT_ACK) {
291 if (frag == 0) {
292 local->dot11TransmittedFrameCount++;
293 if (is_multicast_ether_addr(hdr->addr1))
294 local->dot11MulticastTransmittedFrameCount++;
295 if (retry_count > 0)
296 local->dot11RetryCount++;
297 if (retry_count > 1)
298 local->dot11MultipleRetryCount++;
299 }
300
301 /* This counter shall be incremented for an acknowledged MPDU
302 * with an individual address in the address 1 field or an MPDU
303 * with a multicast address in the address 1 field of type Data
304 * or Management. */
305 if (!is_multicast_ether_addr(hdr->addr1) ||
306 type == IEEE80211_FTYPE_DATA ||
307 type == IEEE80211_FTYPE_MGMT)
308 local->dot11TransmittedFragmentCount++;
309 } else {
310 if (frag == 0)
311 local->dot11FailedCount++;
312 }
313
314 if (ieee80211_is_nullfunc(fc) && ieee80211_has_pm(fc) &&
315 (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS) &&
316 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
317 local->ps_sdata && !(local->scanning)) {
318 if (info->flags & IEEE80211_TX_STAT_ACK) {
319 local->ps_sdata->u.mgd.flags |=
320 IEEE80211_STA_NULLFUNC_ACKED;
321 } else
322 mod_timer(&local->dynamic_ps_timer, jiffies +
323 msecs_to_jiffies(10));
324 }
325
326 if (info->flags & IEEE80211_TX_INTFL_NL80211_FRAME_TX) {
327 struct ieee80211_work *wk;
328 u64 cookie = (unsigned long)skb;
329
330 rcu_read_lock();
331 list_for_each_entry_rcu(wk, &local->work_list, list) {
332 if (wk->type != IEEE80211_WORK_OFFCHANNEL_TX)
333 continue;
334 if (wk->offchan_tx.frame != skb)
335 continue;
336 wk->offchan_tx.frame = NULL;
337 break;
338 }
339 rcu_read_unlock();
340 if (local->hw_roc_skb_for_status == skb) {
341 cookie = local->hw_roc_cookie ^ 2;
342 local->hw_roc_skb_for_status = NULL;
343 }
344
345 if (cookie == local->hw_offchan_tx_cookie)
346 local->hw_offchan_tx_cookie = 0;
347
348 cfg80211_mgmt_tx_status(
349 skb->dev, cookie, skb->data, skb->len,
350 !!(info->flags & IEEE80211_TX_STAT_ACK), GFP_ATOMIC);
351 }
352
353 /* this was a transmitted frame, but now we want to reuse it */
354 skb_orphan(skb);
355
356 /* Need to make a copy before skb->cb gets cleared */
357 send_to_cooked = !!(info->flags & IEEE80211_TX_CTL_INJECTED) ||
358 (type != IEEE80211_FTYPE_DATA);
359
360 /*
361 * This is a bit racy but we can avoid a lot of work
362 * with this test...
363 */
364 if (!local->monitors && (!send_to_cooked || !local->cooked_mntrs)) {
365 dev_kfree_skb(skb);
366 return;
367 }
368
369 /* send frame to monitor interfaces now */
370
371 if (skb_headroom(skb) < sizeof(*rthdr)) {
372 printk(KERN_ERR "ieee80211_tx_status: headroom too small\n");
373 dev_kfree_skb(skb);
374 return;
375 }
376
377 rthdr = (struct ieee80211_tx_status_rtap_hdr *)
378 skb_push(skb, sizeof(*rthdr));
379
380 memset(rthdr, 0, sizeof(*rthdr));
381 rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
382 rthdr->hdr.it_present =
383 cpu_to_le32((1 << IEEE80211_RADIOTAP_TX_FLAGS) |
384 (1 << IEEE80211_RADIOTAP_DATA_RETRIES) |
385 (1 << IEEE80211_RADIOTAP_RATE));
386
387 if (!(info->flags & IEEE80211_TX_STAT_ACK) &&
388 !is_multicast_ether_addr(hdr->addr1))
389 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_FAIL);
390
391 /*
392 * XXX: Once radiotap gets the bitmap reset thing the vendor
393 * extensions proposal contains, we can actually report
394 * the whole set of tries we did.
395 */
396 if ((info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) ||
397 (info->status.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
398 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_CTS);
399 else if (info->status.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS)
400 rthdr->tx_flags |= cpu_to_le16(IEEE80211_RADIOTAP_F_TX_RTS);
401 if (info->status.rates[0].idx >= 0 &&
402 !(info->status.rates[0].flags & IEEE80211_TX_RC_MCS))
403 rthdr->rate = sband->bitrates[
404 info->status.rates[0].idx].bitrate / 5;
405
406 /* for now report the total retry_count */
407 rthdr->data_retries = retry_count;
408
409 /* XXX: is this sufficient for BPF? */
410 skb_set_mac_header(skb, 0);
411 skb->ip_summed = CHECKSUM_UNNECESSARY;
412 skb->pkt_type = PACKET_OTHERHOST;
413 skb->protocol = htons(ETH_P_802_2);
414 memset(skb->cb, 0, sizeof(skb->cb));
415
416 rcu_read_lock();
417 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
418 if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
419 if (!ieee80211_sdata_running(sdata))
420 continue;
421
422 if ((sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES) &&
423 !send_to_cooked)
424 continue;
425
426 if (prev_dev) {
427 skb2 = skb_clone(skb, GFP_ATOMIC);
428 if (skb2) {
429 skb2->dev = prev_dev;
430 netif_rx(skb2);
431 }
432 }
433
434 prev_dev = sdata->dev;
435 }
436 }
437 if (prev_dev) {
438 skb->dev = prev_dev;
439 netif_rx(skb);
440 skb = NULL;
441 }
442 rcu_read_unlock();
443 dev_kfree_skb(skb);
444 }
445 EXPORT_SYMBOL(ieee80211_tx_status);
446