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1 | /* | |
2 | * HT handling | |
3 | * | |
4 | * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> | |
5 | * Copyright 2002-2005, Instant802 Networks, Inc. | |
6 | * Copyright 2005-2006, Devicescape Software, Inc. | |
7 | * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> | |
8 | * Copyright 2007, Michael Wu <flamingice@sourmilk.net> | |
9 | * Copyright 2007-2010, Intel Corporation | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | */ | |
15 | ||
16 | #include <linux/ieee80211.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/export.h> | |
19 | #include <net/mac80211.h> | |
20 | #include "ieee80211_i.h" | |
21 | #include "driver-ops.h" | |
22 | #include "wme.h" | |
23 | ||
24 | /** | |
25 | * DOC: TX A-MPDU aggregation | |
26 | * | |
27 | * Aggregation on the TX side requires setting the hardware flag | |
28 | * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed | |
29 | * packets with a flag indicating A-MPDU aggregation. The driver | |
30 | * or device is responsible for actually aggregating the frames, | |
31 | * as well as deciding how many and which to aggregate. | |
32 | * | |
33 | * When TX aggregation is started by some subsystem (usually the rate | |
34 | * control algorithm would be appropriate) by calling the | |
35 | * ieee80211_start_tx_ba_session() function, the driver will be | |
36 | * notified via its @ampdu_action function, with the | |
37 | * %IEEE80211_AMPDU_TX_START action. | |
38 | * | |
39 | * In response to that, the driver is later required to call the | |
40 | * ieee80211_start_tx_ba_cb_irqsafe() function, which will really | |
41 | * start the aggregation session after the peer has also responded. | |
42 | * If the peer responds negatively, the session will be stopped | |
43 | * again right away. Note that it is possible for the aggregation | |
44 | * session to be stopped before the driver has indicated that it | |
45 | * is done setting it up, in which case it must not indicate the | |
46 | * setup completion. | |
47 | * | |
48 | * Also note that, since we also need to wait for a response from | |
49 | * the peer, the driver is notified of the completion of the | |
50 | * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the | |
51 | * @ampdu_action callback. | |
52 | * | |
53 | * Similarly, when the aggregation session is stopped by the peer | |
54 | * or something calling ieee80211_stop_tx_ba_session(), the driver's | |
55 | * @ampdu_action function will be called with the action | |
56 | * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, | |
57 | * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). | |
58 | * Note that the sta can get destroyed before the BA tear down is | |
59 | * complete. | |
60 | */ | |
61 | ||
62 | static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, | |
63 | const u8 *da, u16 tid, | |
64 | u8 dialog_token, u16 start_seq_num, | |
65 | u16 agg_size, u16 timeout) | |
66 | { | |
67 | struct ieee80211_local *local = sdata->local; | |
68 | struct sk_buff *skb; | |
69 | struct ieee80211_mgmt *mgmt; | |
70 | u16 capab; | |
71 | ||
72 | skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom); | |
73 | ||
74 | if (!skb) | |
75 | return; | |
76 | ||
77 | skb_reserve(skb, local->hw.extra_tx_headroom); | |
78 | mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24); | |
79 | memset(mgmt, 0, 24); | |
80 | memcpy(mgmt->da, da, ETH_ALEN); | |
81 | memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); | |
82 | if (sdata->vif.type == NL80211_IFTYPE_AP || | |
83 | sdata->vif.type == NL80211_IFTYPE_AP_VLAN || | |
84 | sdata->vif.type == NL80211_IFTYPE_MESH_POINT) | |
85 | memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); | |
86 | else if (sdata->vif.type == NL80211_IFTYPE_STATION) | |
87 | memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN); | |
88 | else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) | |
89 | memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN); | |
90 | ||
91 | mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | | |
92 | IEEE80211_STYPE_ACTION); | |
93 | ||
94 | skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req)); | |
95 | ||
96 | mgmt->u.action.category = WLAN_CATEGORY_BACK; | |
97 | mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ; | |
98 | ||
99 | mgmt->u.action.u.addba_req.dialog_token = dialog_token; | |
100 | capab = (u16)(1 << 1); /* bit 1 aggregation policy */ | |
101 | capab |= (u16)(tid << 2); /* bit 5:2 TID number */ | |
102 | capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */ | |
103 | ||
104 | mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab); | |
105 | ||
106 | mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout); | |
107 | mgmt->u.action.u.addba_req.start_seq_num = | |
108 | cpu_to_le16(start_seq_num << 4); | |
109 | ||
110 | ieee80211_tx_skb_tid(sdata, skb, tid); | |
111 | } | |
112 | ||
113 | void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn) | |
114 | { | |
115 | struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); | |
116 | struct ieee80211_local *local = sdata->local; | |
117 | struct sk_buff *skb; | |
118 | struct ieee80211_bar *bar; | |
119 | u16 bar_control = 0; | |
120 | ||
121 | skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom); | |
122 | if (!skb) | |
123 | return; | |
124 | ||
125 | skb_reserve(skb, local->hw.extra_tx_headroom); | |
126 | bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar)); | |
127 | memset(bar, 0, sizeof(*bar)); | |
128 | bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | | |
129 | IEEE80211_STYPE_BACK_REQ); | |
130 | memcpy(bar->ra, ra, ETH_ALEN); | |
131 | memcpy(bar->ta, sdata->vif.addr, ETH_ALEN); | |
132 | bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL; | |
133 | bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA; | |
134 | bar_control |= (u16)(tid << IEEE80211_BAR_CTRL_TID_INFO_SHIFT); | |
135 | bar->control = cpu_to_le16(bar_control); | |
136 | bar->start_seq_num = cpu_to_le16(ssn); | |
137 | ||
138 | IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT | | |
139 | IEEE80211_TX_CTL_REQ_TX_STATUS; | |
140 | ieee80211_tx_skb_tid(sdata, skb, tid); | |
141 | } | |
142 | EXPORT_SYMBOL(ieee80211_send_bar); | |
143 | ||
144 | void ieee80211_assign_tid_tx(struct sta_info *sta, int tid, | |
145 | struct tid_ampdu_tx *tid_tx) | |
146 | { | |
147 | lockdep_assert_held(&sta->ampdu_mlme.mtx); | |
148 | lockdep_assert_held(&sta->lock); | |
149 | rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx); | |
150 | } | |
151 | ||
152 | static inline int ieee80211_ac_from_tid(int tid) | |
153 | { | |
154 | return ieee802_1d_to_ac[tid & 7]; | |
155 | } | |
156 | ||
157 | /* | |
158 | * When multiple aggregation sessions on multiple stations | |
159 | * are being created/destroyed simultaneously, we need to | |
160 | * refcount the global queue stop caused by that in order | |
161 | * to not get into a situation where one of the aggregation | |
162 | * setup or teardown re-enables queues before the other is | |
163 | * ready to handle that. | |
164 | * | |
165 | * These two functions take care of this issue by keeping | |
166 | * a global "agg_queue_stop" refcount. | |
167 | */ | |
168 | static void __acquires(agg_queue) | |
169 | ieee80211_stop_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) | |
170 | { | |
171 | int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; | |
172 | ||
173 | if (atomic_inc_return(&sdata->local->agg_queue_stop[queue]) == 1) | |
174 | ieee80211_stop_queue_by_reason( | |
175 | &sdata->local->hw, queue, | |
176 | IEEE80211_QUEUE_STOP_REASON_AGGREGATION); | |
177 | __acquire(agg_queue); | |
178 | } | |
179 | ||
180 | static void __releases(agg_queue) | |
181 | ieee80211_wake_queue_agg(struct ieee80211_sub_if_data *sdata, int tid) | |
182 | { | |
183 | int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; | |
184 | ||
185 | if (atomic_dec_return(&sdata->local->agg_queue_stop[queue]) == 0) | |
186 | ieee80211_wake_queue_by_reason( | |
187 | &sdata->local->hw, queue, | |
188 | IEEE80211_QUEUE_STOP_REASON_AGGREGATION); | |
189 | __release(agg_queue); | |
190 | } | |
191 | ||
192 | /* | |
193 | * splice packets from the STA's pending to the local pending, | |
194 | * requires a call to ieee80211_agg_splice_finish later | |
195 | */ | |
196 | static void __acquires(agg_queue) | |
197 | ieee80211_agg_splice_packets(struct ieee80211_sub_if_data *sdata, | |
198 | struct tid_ampdu_tx *tid_tx, u16 tid) | |
199 | { | |
200 | struct ieee80211_local *local = sdata->local; | |
201 | int queue = sdata->vif.hw_queue[ieee80211_ac_from_tid(tid)]; | |
202 | unsigned long flags; | |
203 | ||
204 | ieee80211_stop_queue_agg(sdata, tid); | |
205 | ||
206 | if (WARN(!tid_tx, | |
207 | "TID %d gone but expected when splicing aggregates from the pending queue\n", | |
208 | tid)) | |
209 | return; | |
210 | ||
211 | if (!skb_queue_empty(&tid_tx->pending)) { | |
212 | spin_lock_irqsave(&local->queue_stop_reason_lock, flags); | |
213 | /* copy over remaining packets */ | |
214 | skb_queue_splice_tail_init(&tid_tx->pending, | |
215 | &local->pending[queue]); | |
216 | spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags); | |
217 | } | |
218 | } | |
219 | ||
220 | static void __releases(agg_queue) | |
221 | ieee80211_agg_splice_finish(struct ieee80211_sub_if_data *sdata, u16 tid) | |
222 | { | |
223 | ieee80211_wake_queue_agg(sdata, tid); | |
224 | } | |
225 | ||
226 | static void ieee80211_remove_tid_tx(struct sta_info *sta, int tid) | |
227 | { | |
228 | struct tid_ampdu_tx *tid_tx; | |
229 | ||
230 | lockdep_assert_held(&sta->ampdu_mlme.mtx); | |
231 | lockdep_assert_held(&sta->lock); | |
232 | ||
233 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
234 | ||
235 | /* | |
236 | * When we get here, the TX path will not be lockless any more wrt. | |
237 | * aggregation, since the OPERATIONAL bit has long been cleared. | |
238 | * Thus it will block on getting the lock, if it occurs. So if we | |
239 | * stop the queue now, we will not get any more packets, and any | |
240 | * that might be being processed will wait for us here, thereby | |
241 | * guaranteeing that no packets go to the tid_tx pending queue any | |
242 | * more. | |
243 | */ | |
244 | ||
245 | ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); | |
246 | ||
247 | /* future packets must not find the tid_tx struct any more */ | |
248 | ieee80211_assign_tid_tx(sta, tid, NULL); | |
249 | ||
250 | ieee80211_agg_splice_finish(sta->sdata, tid); | |
251 | ||
252 | kfree_rcu(tid_tx, rcu_head); | |
253 | } | |
254 | ||
255 | int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, | |
256 | enum ieee80211_agg_stop_reason reason) | |
257 | { | |
258 | struct ieee80211_local *local = sta->local; | |
259 | struct tid_ampdu_tx *tid_tx; | |
260 | enum ieee80211_ampdu_mlme_action action; | |
261 | int ret; | |
262 | ||
263 | lockdep_assert_held(&sta->ampdu_mlme.mtx); | |
264 | ||
265 | switch (reason) { | |
266 | case AGG_STOP_DECLINED: | |
267 | case AGG_STOP_LOCAL_REQUEST: | |
268 | case AGG_STOP_PEER_REQUEST: | |
269 | action = IEEE80211_AMPDU_TX_STOP_CONT; | |
270 | break; | |
271 | case AGG_STOP_DESTROY_STA: | |
272 | action = IEEE80211_AMPDU_TX_STOP_FLUSH; | |
273 | break; | |
274 | default: | |
275 | WARN_ON_ONCE(1); | |
276 | return -EINVAL; | |
277 | } | |
278 | ||
279 | spin_lock_bh(&sta->lock); | |
280 | ||
281 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
282 | if (!tid_tx) { | |
283 | spin_unlock_bh(&sta->lock); | |
284 | return -ENOENT; | |
285 | } | |
286 | ||
287 | /* | |
288 | * if we're already stopping ignore any new requests to stop | |
289 | * unless we're destroying it in which case notify the driver | |
290 | */ | |
291 | if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { | |
292 | spin_unlock_bh(&sta->lock); | |
293 | if (reason != AGG_STOP_DESTROY_STA) | |
294 | return -EALREADY; | |
295 | ret = drv_ampdu_action(local, sta->sdata, | |
296 | IEEE80211_AMPDU_TX_STOP_FLUSH_CONT, | |
297 | &sta->sta, tid, NULL, 0); | |
298 | WARN_ON_ONCE(ret); | |
299 | return 0; | |
300 | } | |
301 | ||
302 | if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) { | |
303 | /* not even started yet! */ | |
304 | ieee80211_assign_tid_tx(sta, tid, NULL); | |
305 | spin_unlock_bh(&sta->lock); | |
306 | kfree_rcu(tid_tx, rcu_head); | |
307 | return 0; | |
308 | } | |
309 | ||
310 | set_bit(HT_AGG_STATE_STOPPING, &tid_tx->state); | |
311 | ||
312 | spin_unlock_bh(&sta->lock); | |
313 | ||
314 | ht_dbg(sta->sdata, "Tx BA session stop requested for %pM tid %u\n", | |
315 | sta->sta.addr, tid); | |
316 | ||
317 | del_timer_sync(&tid_tx->addba_resp_timer); | |
318 | del_timer_sync(&tid_tx->session_timer); | |
319 | ||
320 | /* | |
321 | * After this packets are no longer handed right through | |
322 | * to the driver but are put onto tid_tx->pending instead, | |
323 | * with locking to ensure proper access. | |
324 | */ | |
325 | clear_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); | |
326 | ||
327 | /* | |
328 | * There might be a few packets being processed right now (on | |
329 | * another CPU) that have already gotten past the aggregation | |
330 | * check when it was still OPERATIONAL and consequently have | |
331 | * IEEE80211_TX_CTL_AMPDU set. In that case, this code might | |
332 | * call into the driver at the same time or even before the | |
333 | * TX paths calls into it, which could confuse the driver. | |
334 | * | |
335 | * Wait for all currently running TX paths to finish before | |
336 | * telling the driver. New packets will not go through since | |
337 | * the aggregation session is no longer OPERATIONAL. | |
338 | */ | |
339 | synchronize_net(); | |
340 | ||
341 | tid_tx->stop_initiator = reason == AGG_STOP_PEER_REQUEST ? | |
342 | WLAN_BACK_RECIPIENT : | |
343 | WLAN_BACK_INITIATOR; | |
344 | tid_tx->tx_stop = reason == AGG_STOP_LOCAL_REQUEST; | |
345 | ||
346 | ret = drv_ampdu_action(local, sta->sdata, action, | |
347 | &sta->sta, tid, NULL, 0); | |
348 | ||
349 | /* HW shall not deny going back to legacy */ | |
350 | if (WARN_ON(ret)) { | |
351 | /* | |
352 | * We may have pending packets get stuck in this case... | |
353 | * Not bothering with a workaround for now. | |
354 | */ | |
355 | } | |
356 | ||
357 | /* | |
358 | * In the case of AGG_STOP_DESTROY_STA, the driver won't | |
359 | * necessarily call ieee80211_stop_tx_ba_cb(), so this may | |
360 | * seem like we can leave the tid_tx data pending forever. | |
361 | * This is true, in a way, but "forever" is only until the | |
362 | * station struct is actually destroyed. In the meantime, | |
363 | * leaving it around ensures that we don't transmit packets | |
364 | * to the driver on this TID which might confuse it. | |
365 | */ | |
366 | ||
367 | return 0; | |
368 | } | |
369 | ||
370 | /* | |
371 | * After sending add Block Ack request we activated a timer until | |
372 | * add Block Ack response will arrive from the recipient. | |
373 | * If this timer expires sta_addba_resp_timer_expired will be executed. | |
374 | */ | |
375 | static void sta_addba_resp_timer_expired(unsigned long data) | |
376 | { | |
377 | /* not an elegant detour, but there is no choice as the timer passes | |
378 | * only one argument, and both sta_info and TID are needed, so init | |
379 | * flow in sta_info_create gives the TID as data, while the timer_to_id | |
380 | * array gives the sta through container_of */ | |
381 | u16 tid = *(u8 *)data; | |
382 | struct sta_info *sta = container_of((void *)data, | |
383 | struct sta_info, timer_to_tid[tid]); | |
384 | struct tid_ampdu_tx *tid_tx; | |
385 | ||
386 | /* check if the TID waits for addBA response */ | |
387 | rcu_read_lock(); | |
388 | tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[tid]); | |
389 | if (!tid_tx || | |
390 | test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) { | |
391 | rcu_read_unlock(); | |
392 | ht_dbg(sta->sdata, | |
393 | "timer expired on %pM tid %d but we are not (or no longer) expecting addBA response there\n", | |
394 | sta->sta.addr, tid); | |
395 | return; | |
396 | } | |
397 | ||
398 | ht_dbg(sta->sdata, "addBA response timer expired on %pM tid %d\n", | |
399 | sta->sta.addr, tid); | |
400 | ||
401 | ieee80211_stop_tx_ba_session(&sta->sta, tid); | |
402 | rcu_read_unlock(); | |
403 | } | |
404 | ||
405 | void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid) | |
406 | { | |
407 | struct tid_ampdu_tx *tid_tx; | |
408 | struct ieee80211_local *local = sta->local; | |
409 | struct ieee80211_sub_if_data *sdata = sta->sdata; | |
410 | u16 start_seq_num; | |
411 | int ret; | |
412 | ||
413 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
414 | ||
415 | /* | |
416 | * Start queuing up packets for this aggregation session. | |
417 | * We're going to release them once the driver is OK with | |
418 | * that. | |
419 | */ | |
420 | clear_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); | |
421 | ||
422 | /* | |
423 | * Make sure no packets are being processed. This ensures that | |
424 | * we have a valid starting sequence number and that in-flight | |
425 | * packets have been flushed out and no packets for this TID | |
426 | * will go into the driver during the ampdu_action call. | |
427 | */ | |
428 | synchronize_net(); | |
429 | ||
430 | start_seq_num = sta->tid_seq[tid] >> 4; | |
431 | ||
432 | ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START, | |
433 | &sta->sta, tid, &start_seq_num, 0); | |
434 | if (ret) { | |
435 | ht_dbg(sdata, | |
436 | "BA request denied - HW unavailable for %pM tid %d\n", | |
437 | sta->sta.addr, tid); | |
438 | spin_lock_bh(&sta->lock); | |
439 | ieee80211_agg_splice_packets(sdata, tid_tx, tid); | |
440 | ieee80211_assign_tid_tx(sta, tid, NULL); | |
441 | ieee80211_agg_splice_finish(sdata, tid); | |
442 | spin_unlock_bh(&sta->lock); | |
443 | ||
444 | kfree_rcu(tid_tx, rcu_head); | |
445 | return; | |
446 | } | |
447 | ||
448 | /* activate the timer for the recipient's addBA response */ | |
449 | mod_timer(&tid_tx->addba_resp_timer, jiffies + ADDBA_RESP_INTERVAL); | |
450 | ht_dbg(sdata, "activated addBA response timer on %pM tid %d\n", | |
451 | sta->sta.addr, tid); | |
452 | ||
453 | spin_lock_bh(&sta->lock); | |
454 | sta->ampdu_mlme.last_addba_req_time[tid] = jiffies; | |
455 | sta->ampdu_mlme.addba_req_num[tid]++; | |
456 | spin_unlock_bh(&sta->lock); | |
457 | ||
458 | /* send AddBA request */ | |
459 | ieee80211_send_addba_request(sdata, sta->sta.addr, tid, | |
460 | tid_tx->dialog_token, start_seq_num, | |
461 | local->hw.max_tx_aggregation_subframes, | |
462 | tid_tx->timeout); | |
463 | } | |
464 | ||
465 | /* | |
466 | * After accepting the AddBA Response we activated a timer, | |
467 | * resetting it after each frame that we send. | |
468 | */ | |
469 | static void sta_tx_agg_session_timer_expired(unsigned long data) | |
470 | { | |
471 | /* not an elegant detour, but there is no choice as the timer passes | |
472 | * only one argument, and various sta_info are needed here, so init | |
473 | * flow in sta_info_create gives the TID as data, while the timer_to_id | |
474 | * array gives the sta through container_of */ | |
475 | u8 *ptid = (u8 *)data; | |
476 | u8 *timer_to_id = ptid - *ptid; | |
477 | struct sta_info *sta = container_of(timer_to_id, struct sta_info, | |
478 | timer_to_tid[0]); | |
479 | struct tid_ampdu_tx *tid_tx; | |
480 | unsigned long timeout; | |
481 | ||
482 | rcu_read_lock(); | |
483 | tid_tx = rcu_dereference(sta->ampdu_mlme.tid_tx[*ptid]); | |
484 | if (!tid_tx || test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { | |
485 | rcu_read_unlock(); | |
486 | return; | |
487 | } | |
488 | ||
489 | timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); | |
490 | if (time_is_after_jiffies(timeout)) { | |
491 | mod_timer(&tid_tx->session_timer, timeout); | |
492 | rcu_read_unlock(); | |
493 | return; | |
494 | } | |
495 | ||
496 | rcu_read_unlock(); | |
497 | ||
498 | ht_dbg(sta->sdata, "tx session timer expired on %pM tid %d\n", | |
499 | sta->sta.addr, (u16)*ptid); | |
500 | ||
501 | ieee80211_stop_tx_ba_session(&sta->sta, *ptid); | |
502 | } | |
503 | ||
504 | int ieee80211_start_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid, | |
505 | u16 timeout) | |
506 | { | |
507 | struct sta_info *sta = container_of(pubsta, struct sta_info, sta); | |
508 | struct ieee80211_sub_if_data *sdata = sta->sdata; | |
509 | struct ieee80211_local *local = sdata->local; | |
510 | struct tid_ampdu_tx *tid_tx; | |
511 | int ret = 0; | |
512 | ||
513 | trace_api_start_tx_ba_session(pubsta, tid); | |
514 | ||
515 | if (WARN_ON_ONCE(!local->ops->ampdu_action)) | |
516 | return -EINVAL; | |
517 | ||
518 | if ((tid >= IEEE80211_NUM_TIDS) || | |
519 | !(local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION) || | |
520 | (local->hw.flags & IEEE80211_HW_TX_AMPDU_SETUP_IN_HW)) | |
521 | return -EINVAL; | |
522 | ||
523 | ht_dbg(sdata, "Open BA session requested for %pM tid %u\n", | |
524 | pubsta->addr, tid); | |
525 | ||
526 | if (sdata->vif.type != NL80211_IFTYPE_STATION && | |
527 | sdata->vif.type != NL80211_IFTYPE_MESH_POINT && | |
528 | sdata->vif.type != NL80211_IFTYPE_AP_VLAN && | |
529 | sdata->vif.type != NL80211_IFTYPE_AP && | |
530 | sdata->vif.type != NL80211_IFTYPE_ADHOC) | |
531 | return -EINVAL; | |
532 | ||
533 | if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) { | |
534 | ht_dbg(sdata, | |
535 | "BA sessions blocked - Denying BA session request %pM tid %d\n", | |
536 | sta->sta.addr, tid); | |
537 | return -EINVAL; | |
538 | } | |
539 | ||
540 | /* | |
541 | * 802.11n-2009 11.5.1.1: If the initiating STA is an HT STA, is a | |
542 | * member of an IBSS, and has no other existing Block Ack agreement | |
543 | * with the recipient STA, then the initiating STA shall transmit a | |
544 | * Probe Request frame to the recipient STA and shall not transmit an | |
545 | * ADDBA Request frame unless it receives a Probe Response frame | |
546 | * from the recipient within dot11ADDBAFailureTimeout. | |
547 | * | |
548 | * The probe request mechanism for ADDBA is currently not implemented, | |
549 | * but we only build up Block Ack session with HT STAs. This information | |
550 | * is set when we receive a bss info from a probe response or a beacon. | |
551 | */ | |
552 | if (sta->sdata->vif.type == NL80211_IFTYPE_ADHOC && | |
553 | !sta->sta.ht_cap.ht_supported) { | |
554 | ht_dbg(sdata, | |
555 | "BA request denied - IBSS STA %pM does not advertise HT support\n", | |
556 | pubsta->addr); | |
557 | return -EINVAL; | |
558 | } | |
559 | ||
560 | spin_lock_bh(&sta->lock); | |
561 | ||
562 | /* we have tried too many times, receiver does not want A-MPDU */ | |
563 | if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) { | |
564 | ret = -EBUSY; | |
565 | goto err_unlock_sta; | |
566 | } | |
567 | ||
568 | /* | |
569 | * if we have tried more than HT_AGG_BURST_RETRIES times we | |
570 | * will spread our requests in time to avoid stalling connection | |
571 | * for too long | |
572 | */ | |
573 | if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_BURST_RETRIES && | |
574 | time_before(jiffies, sta->ampdu_mlme.last_addba_req_time[tid] + | |
575 | HT_AGG_RETRIES_PERIOD)) { | |
576 | ht_dbg(sdata, | |
577 | "BA request denied - waiting a grace period after %d failed requests on %pM tid %u\n", | |
578 | sta->ampdu_mlme.addba_req_num[tid], sta->sta.addr, tid); | |
579 | ret = -EBUSY; | |
580 | goto err_unlock_sta; | |
581 | } | |
582 | ||
583 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
584 | /* check if the TID is not in aggregation flow already */ | |
585 | if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) { | |
586 | ht_dbg(sdata, | |
587 | "BA request denied - session is not idle on %pM tid %u\n", | |
588 | sta->sta.addr, tid); | |
589 | ret = -EAGAIN; | |
590 | goto err_unlock_sta; | |
591 | } | |
592 | ||
593 | /* prepare A-MPDU MLME for Tx aggregation */ | |
594 | tid_tx = kzalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC); | |
595 | if (!tid_tx) { | |
596 | ret = -ENOMEM; | |
597 | goto err_unlock_sta; | |
598 | } | |
599 | ||
600 | skb_queue_head_init(&tid_tx->pending); | |
601 | __set_bit(HT_AGG_STATE_WANT_START, &tid_tx->state); | |
602 | ||
603 | tid_tx->timeout = timeout; | |
604 | ||
605 | /* response timer */ | |
606 | tid_tx->addba_resp_timer.function = sta_addba_resp_timer_expired; | |
607 | tid_tx->addba_resp_timer.data = (unsigned long)&sta->timer_to_tid[tid]; | |
608 | init_timer(&tid_tx->addba_resp_timer); | |
609 | ||
610 | /* tx timer */ | |
611 | tid_tx->session_timer.function = sta_tx_agg_session_timer_expired; | |
612 | tid_tx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid]; | |
613 | init_timer_deferrable(&tid_tx->session_timer); | |
614 | ||
615 | /* assign a dialog token */ | |
616 | sta->ampdu_mlme.dialog_token_allocator++; | |
617 | tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator; | |
618 | ||
619 | /* | |
620 | * Finally, assign it to the start array; the work item will | |
621 | * collect it and move it to the normal array. | |
622 | */ | |
623 | sta->ampdu_mlme.tid_start_tx[tid] = tid_tx; | |
624 | ||
625 | ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); | |
626 | ||
627 | /* this flow continues off the work */ | |
628 | err_unlock_sta: | |
629 | spin_unlock_bh(&sta->lock); | |
630 | return ret; | |
631 | } | |
632 | EXPORT_SYMBOL(ieee80211_start_tx_ba_session); | |
633 | ||
634 | static void ieee80211_agg_tx_operational(struct ieee80211_local *local, | |
635 | struct sta_info *sta, u16 tid) | |
636 | { | |
637 | struct tid_ampdu_tx *tid_tx; | |
638 | ||
639 | lockdep_assert_held(&sta->ampdu_mlme.mtx); | |
640 | ||
641 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
642 | ||
643 | ht_dbg(sta->sdata, "Aggregation is on for %pM tid %d\n", | |
644 | sta->sta.addr, tid); | |
645 | ||
646 | drv_ampdu_action(local, sta->sdata, | |
647 | IEEE80211_AMPDU_TX_OPERATIONAL, | |
648 | &sta->sta, tid, NULL, tid_tx->buf_size); | |
649 | ||
650 | /* | |
651 | * synchronize with TX path, while splicing the TX path | |
652 | * should block so it won't put more packets onto pending. | |
653 | */ | |
654 | spin_lock_bh(&sta->lock); | |
655 | ||
656 | ieee80211_agg_splice_packets(sta->sdata, tid_tx, tid); | |
657 | /* | |
658 | * Now mark as operational. This will be visible | |
659 | * in the TX path, and lets it go lock-free in | |
660 | * the common case. | |
661 | */ | |
662 | set_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state); | |
663 | ieee80211_agg_splice_finish(sta->sdata, tid); | |
664 | ||
665 | spin_unlock_bh(&sta->lock); | |
666 | } | |
667 | ||
668 | void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) | |
669 | { | |
670 | struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); | |
671 | struct ieee80211_local *local = sdata->local; | |
672 | struct sta_info *sta; | |
673 | struct tid_ampdu_tx *tid_tx; | |
674 | ||
675 | trace_api_start_tx_ba_cb(sdata, ra, tid); | |
676 | ||
677 | if (tid >= IEEE80211_NUM_TIDS) { | |
678 | ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", | |
679 | tid, IEEE80211_NUM_TIDS); | |
680 | return; | |
681 | } | |
682 | ||
683 | mutex_lock(&local->sta_mtx); | |
684 | sta = sta_info_get_bss(sdata, ra); | |
685 | if (!sta) { | |
686 | mutex_unlock(&local->sta_mtx); | |
687 | ht_dbg(sdata, "Could not find station: %pM\n", ra); | |
688 | return; | |
689 | } | |
690 | ||
691 | mutex_lock(&sta->ampdu_mlme.mtx); | |
692 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
693 | ||
694 | if (WARN_ON(!tid_tx)) { | |
695 | ht_dbg(sdata, "addBA was not requested!\n"); | |
696 | goto unlock; | |
697 | } | |
698 | ||
699 | if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) | |
700 | goto unlock; | |
701 | ||
702 | if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) | |
703 | ieee80211_agg_tx_operational(local, sta, tid); | |
704 | ||
705 | unlock: | |
706 | mutex_unlock(&sta->ampdu_mlme.mtx); | |
707 | mutex_unlock(&local->sta_mtx); | |
708 | } | |
709 | ||
710 | void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, | |
711 | const u8 *ra, u16 tid) | |
712 | { | |
713 | struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); | |
714 | struct ieee80211_local *local = sdata->local; | |
715 | struct ieee80211_ra_tid *ra_tid; | |
716 | struct sk_buff *skb = dev_alloc_skb(0); | |
717 | ||
718 | if (unlikely(!skb)) | |
719 | return; | |
720 | ||
721 | ra_tid = (struct ieee80211_ra_tid *) &skb->cb; | |
722 | memcpy(&ra_tid->ra, ra, ETH_ALEN); | |
723 | ra_tid->tid = tid; | |
724 | ||
725 | skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; | |
726 | skb_queue_tail(&sdata->skb_queue, skb); | |
727 | ieee80211_queue_work(&local->hw, &sdata->work); | |
728 | } | |
729 | EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); | |
730 | ||
731 | int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, | |
732 | enum ieee80211_agg_stop_reason reason) | |
733 | { | |
734 | int ret; | |
735 | ||
736 | mutex_lock(&sta->ampdu_mlme.mtx); | |
737 | ||
738 | ret = ___ieee80211_stop_tx_ba_session(sta, tid, reason); | |
739 | ||
740 | mutex_unlock(&sta->ampdu_mlme.mtx); | |
741 | ||
742 | return ret; | |
743 | } | |
744 | ||
745 | int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) | |
746 | { | |
747 | struct sta_info *sta = container_of(pubsta, struct sta_info, sta); | |
748 | struct ieee80211_sub_if_data *sdata = sta->sdata; | |
749 | struct ieee80211_local *local = sdata->local; | |
750 | struct tid_ampdu_tx *tid_tx; | |
751 | int ret = 0; | |
752 | ||
753 | trace_api_stop_tx_ba_session(pubsta, tid); | |
754 | ||
755 | if (!local->ops->ampdu_action) | |
756 | return -EINVAL; | |
757 | ||
758 | if (tid >= IEEE80211_NUM_TIDS) | |
759 | return -EINVAL; | |
760 | ||
761 | spin_lock_bh(&sta->lock); | |
762 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
763 | ||
764 | if (!tid_tx) { | |
765 | ret = -ENOENT; | |
766 | goto unlock; | |
767 | } | |
768 | ||
769 | if (test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { | |
770 | /* already in progress stopping it */ | |
771 | ret = 0; | |
772 | goto unlock; | |
773 | } | |
774 | ||
775 | set_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state); | |
776 | ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); | |
777 | ||
778 | unlock: | |
779 | spin_unlock_bh(&sta->lock); | |
780 | return ret; | |
781 | } | |
782 | EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); | |
783 | ||
784 | void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) | |
785 | { | |
786 | struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); | |
787 | struct ieee80211_local *local = sdata->local; | |
788 | struct sta_info *sta; | |
789 | struct tid_ampdu_tx *tid_tx; | |
790 | ||
791 | trace_api_stop_tx_ba_cb(sdata, ra, tid); | |
792 | ||
793 | if (tid >= IEEE80211_NUM_TIDS) { | |
794 | ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", | |
795 | tid, IEEE80211_NUM_TIDS); | |
796 | return; | |
797 | } | |
798 | ||
799 | ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid); | |
800 | ||
801 | mutex_lock(&local->sta_mtx); | |
802 | ||
803 | sta = sta_info_get_bss(sdata, ra); | |
804 | if (!sta) { | |
805 | ht_dbg(sdata, "Could not find station: %pM\n", ra); | |
806 | goto unlock; | |
807 | } | |
808 | ||
809 | mutex_lock(&sta->ampdu_mlme.mtx); | |
810 | spin_lock_bh(&sta->lock); | |
811 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
812 | ||
813 | if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { | |
814 | ht_dbg(sdata, | |
815 | "unexpected callback to A-MPDU stop for %pM tid %d\n", | |
816 | sta->sta.addr, tid); | |
817 | goto unlock_sta; | |
818 | } | |
819 | ||
820 | if (tid_tx->stop_initiator == WLAN_BACK_INITIATOR && tid_tx->tx_stop) | |
821 | ieee80211_send_delba(sta->sdata, ra, tid, | |
822 | WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); | |
823 | ||
824 | ieee80211_remove_tid_tx(sta, tid); | |
825 | ||
826 | unlock_sta: | |
827 | spin_unlock_bh(&sta->lock); | |
828 | mutex_unlock(&sta->ampdu_mlme.mtx); | |
829 | unlock: | |
830 | mutex_unlock(&local->sta_mtx); | |
831 | } | |
832 | ||
833 | void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, | |
834 | const u8 *ra, u16 tid) | |
835 | { | |
836 | struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); | |
837 | struct ieee80211_local *local = sdata->local; | |
838 | struct ieee80211_ra_tid *ra_tid; | |
839 | struct sk_buff *skb = dev_alloc_skb(0); | |
840 | ||
841 | if (unlikely(!skb)) | |
842 | return; | |
843 | ||
844 | ra_tid = (struct ieee80211_ra_tid *) &skb->cb; | |
845 | memcpy(&ra_tid->ra, ra, ETH_ALEN); | |
846 | ra_tid->tid = tid; | |
847 | ||
848 | skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; | |
849 | skb_queue_tail(&sdata->skb_queue, skb); | |
850 | ieee80211_queue_work(&local->hw, &sdata->work); | |
851 | } | |
852 | EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); | |
853 | ||
854 | ||
855 | void ieee80211_process_addba_resp(struct ieee80211_local *local, | |
856 | struct sta_info *sta, | |
857 | struct ieee80211_mgmt *mgmt, | |
858 | size_t len) | |
859 | { | |
860 | struct tid_ampdu_tx *tid_tx; | |
861 | u16 capab, tid; | |
862 | u8 buf_size; | |
863 | ||
864 | capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab); | |
865 | tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2; | |
866 | buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6; | |
867 | ||
868 | mutex_lock(&sta->ampdu_mlme.mtx); | |
869 | ||
870 | tid_tx = rcu_dereference_protected_tid_tx(sta, tid); | |
871 | if (!tid_tx) | |
872 | goto out; | |
873 | ||
874 | if (mgmt->u.action.u.addba_resp.dialog_token != tid_tx->dialog_token) { | |
875 | ht_dbg(sta->sdata, "wrong addBA response token, %pM tid %d\n", | |
876 | sta->sta.addr, tid); | |
877 | goto out; | |
878 | } | |
879 | ||
880 | del_timer_sync(&tid_tx->addba_resp_timer); | |
881 | ||
882 | ht_dbg(sta->sdata, "switched off addBA timer for %pM tid %d\n", | |
883 | sta->sta.addr, tid); | |
884 | ||
885 | /* | |
886 | * addba_resp_timer may have fired before we got here, and | |
887 | * caused WANT_STOP to be set. If the stop then was already | |
888 | * processed further, STOPPING might be set. | |
889 | */ | |
890 | if (test_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state) || | |
891 | test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { | |
892 | ht_dbg(sta->sdata, | |
893 | "got addBA resp for %pM tid %d but we already gave up\n", | |
894 | sta->sta.addr, tid); | |
895 | goto out; | |
896 | } | |
897 | ||
898 | /* | |
899 | * IEEE 802.11-2007 7.3.1.14: | |
900 | * In an ADDBA Response frame, when the Status Code field | |
901 | * is set to 0, the Buffer Size subfield is set to a value | |
902 | * of at least 1. | |
903 | */ | |
904 | if (le16_to_cpu(mgmt->u.action.u.addba_resp.status) | |
905 | == WLAN_STATUS_SUCCESS && buf_size) { | |
906 | if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED, | |
907 | &tid_tx->state)) { | |
908 | /* ignore duplicate response */ | |
909 | goto out; | |
910 | } | |
911 | ||
912 | tid_tx->buf_size = buf_size; | |
913 | ||
914 | if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state)) | |
915 | ieee80211_agg_tx_operational(local, sta, tid); | |
916 | ||
917 | sta->ampdu_mlme.addba_req_num[tid] = 0; | |
918 | ||
919 | if (tid_tx->timeout) { | |
920 | mod_timer(&tid_tx->session_timer, | |
921 | TU_TO_EXP_TIME(tid_tx->timeout)); | |
922 | tid_tx->last_tx = jiffies; | |
923 | } | |
924 | ||
925 | } else { | |
926 | ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_DECLINED); | |
927 | } | |
928 | ||
929 | out: | |
930 | mutex_unlock(&sta->ampdu_mlme.mtx); | |
931 | } |