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 * Copyright(c) 2015-2017 Intel Deutschland GmbH
11 * Copyright (C) 2018 Intel Corporation
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
16 */
17
18 /**
19 * DOC: RX A-MPDU aggregation
20 *
21 * Aggregation on the RX side requires only implementing the
22 * @ampdu_action callback that is invoked to start/stop any
23 * block-ack sessions for RX aggregation.
24 *
25 * When RX aggregation is started by the peer, the driver is
26 * notified via @ampdu_action function, with the
27 * %IEEE80211_AMPDU_RX_START action, and may reject the request
28 * in which case a negative response is sent to the peer, if it
29 * accepts it a positive response is sent.
30 *
31 * While the session is active, the device/driver are required
32 * to de-aggregate frames and pass them up one by one to mac80211,
33 * which will handle the reorder buffer.
34 *
35 * When the aggregation session is stopped again by the peer or
36 * ourselves, the driver's @ampdu_action function will be called
37 * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
38 * call must not fail.
39 */
40
41 #include <linux/ieee80211.h>
42 #include <linux/slab.h>
43 #include <linux/export.h>
44 #include <net/mac80211.h>
45 #include "ieee80211_i.h"
46 #include "driver-ops.h"
47
ieee80211_free_tid_rx(struct rcu_head * h)48 static void ieee80211_free_tid_rx(struct rcu_head *h)
49 {
50 struct tid_ampdu_rx *tid_rx =
51 container_of(h, struct tid_ampdu_rx, rcu_head);
52 int i;
53
54 for (i = 0; i < tid_rx->buf_size; i++)
55 __skb_queue_purge(&tid_rx->reorder_buf[i]);
56 kfree(tid_rx->reorder_buf);
57 kfree(tid_rx->reorder_time);
58 kfree(tid_rx);
59 }
60
___ieee80211_stop_rx_ba_session(struct sta_info * sta,u16 tid,u16 initiator,u16 reason,bool tx)61 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
62 u16 initiator, u16 reason, bool tx)
63 {
64 struct ieee80211_local *local = sta->local;
65 struct tid_ampdu_rx *tid_rx;
66 struct ieee80211_ampdu_params params = {
67 .sta = &sta->sta,
68 .action = IEEE80211_AMPDU_RX_STOP,
69 .tid = tid,
70 .amsdu = false,
71 .timeout = 0,
72 .ssn = 0,
73 };
74
75 lockdep_assert_held(&sta->ampdu_mlme.mtx);
76
77 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
78 lockdep_is_held(&sta->ampdu_mlme.mtx));
79
80 if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
81 return;
82
83 RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
84 __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
85
86 ht_dbg(sta->sdata,
87 "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
88 sta->sta.addr, tid,
89 initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
90 (int)reason);
91
92 if (drv_ampdu_action(local, sta->sdata, ¶ms))
93 sdata_info(sta->sdata,
94 "HW problem - can not stop rx aggregation for %pM tid %d\n",
95 sta->sta.addr, tid);
96
97 /* check if this is a self generated aggregation halt */
98 if (initiator == WLAN_BACK_RECIPIENT && tx)
99 ieee80211_send_delba(sta->sdata, sta->sta.addr,
100 tid, WLAN_BACK_RECIPIENT, reason);
101
102 /*
103 * return here in case tid_rx is not assigned - which will happen if
104 * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
105 */
106 if (!tid_rx)
107 return;
108
109 del_timer_sync(&tid_rx->session_timer);
110
111 /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
112 spin_lock_bh(&tid_rx->reorder_lock);
113 tid_rx->removed = true;
114 spin_unlock_bh(&tid_rx->reorder_lock);
115 del_timer_sync(&tid_rx->reorder_timer);
116
117 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
118 }
119
__ieee80211_stop_rx_ba_session(struct sta_info * sta,u16 tid,u16 initiator,u16 reason,bool tx)120 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
121 u16 initiator, u16 reason, bool tx)
122 {
123 mutex_lock(&sta->ampdu_mlme.mtx);
124 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
125 mutex_unlock(&sta->ampdu_mlme.mtx);
126 }
127
ieee80211_stop_rx_ba_session(struct ieee80211_vif * vif,u16 ba_rx_bitmap,const u8 * addr)128 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
129 const u8 *addr)
130 {
131 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
132 struct sta_info *sta;
133 int i;
134
135 rcu_read_lock();
136 sta = sta_info_get_bss(sdata, addr);
137 if (!sta) {
138 rcu_read_unlock();
139 return;
140 }
141
142 for (i = 0; i < IEEE80211_NUM_TIDS; i++)
143 if (ba_rx_bitmap & BIT(i))
144 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
145
146 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
147 rcu_read_unlock();
148 }
149 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
150
151 /*
152 * After accepting the AddBA Request we activated a timer,
153 * resetting it after each frame that arrives from the originator.
154 */
sta_rx_agg_session_timer_expired(unsigned long data)155 static void sta_rx_agg_session_timer_expired(unsigned long data)
156 {
157 /* not an elegant detour, but there is no choice as the timer passes
158 * only one argument, and various sta_info are needed here, so init
159 * flow in sta_info_create gives the TID as data, while the timer_to_id
160 * array gives the sta through container_of */
161 u8 *ptid = (u8 *)data;
162 u8 *timer_to_id = ptid - *ptid;
163 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
164 timer_to_tid[0]);
165 struct tid_ampdu_rx *tid_rx;
166 unsigned long timeout;
167
168 rcu_read_lock();
169 tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
170 if (!tid_rx) {
171 rcu_read_unlock();
172 return;
173 }
174
175 timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
176 if (time_is_after_jiffies(timeout)) {
177 mod_timer(&tid_rx->session_timer, timeout);
178 rcu_read_unlock();
179 return;
180 }
181 rcu_read_unlock();
182
183 ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
184 sta->sta.addr, (u16)*ptid);
185
186 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
187 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
188 }
189
sta_rx_agg_reorder_timer_expired(unsigned long data)190 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
191 {
192 u8 *ptid = (u8 *)data;
193 u8 *timer_to_id = ptid - *ptid;
194 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
195 timer_to_tid[0]);
196
197 rcu_read_lock();
198 ieee80211_release_reorder_timeout(sta, *ptid);
199 rcu_read_unlock();
200 }
201
ieee80211_send_addba_resp(struct ieee80211_sub_if_data * sdata,u8 * da,u16 tid,u8 dialog_token,u16 status,u16 policy,u16 buf_size,u16 timeout)202 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
203 u8 dialog_token, u16 status, u16 policy,
204 u16 buf_size, u16 timeout)
205 {
206 struct ieee80211_local *local = sdata->local;
207 struct sk_buff *skb;
208 struct ieee80211_mgmt *mgmt;
209 bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
210 u16 capab;
211
212 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
213 if (!skb)
214 return;
215
216 skb_reserve(skb, local->hw.extra_tx_headroom);
217 mgmt = skb_put_zero(skb, 24);
218 memcpy(mgmt->da, da, ETH_ALEN);
219 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
220 if (sdata->vif.type == NL80211_IFTYPE_AP ||
221 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
222 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
223 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
224 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
225 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
226 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
227 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
228
229 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
230 IEEE80211_STYPE_ACTION);
231
232 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
233 mgmt->u.action.category = WLAN_CATEGORY_BACK;
234 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
235 mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
236
237 capab = (u16)(amsdu << 0); /* bit 0 A-MSDU support */
238 capab |= (u16)(policy << 1); /* bit 1 aggregation policy */
239 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
240 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
241
242 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
243 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
244 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
245
246 ieee80211_tx_skb(sdata, skb);
247 }
248
___ieee80211_start_rx_ba_session(struct sta_info * sta,u8 dialog_token,u16 timeout,u16 start_seq_num,u16 ba_policy,u16 tid,u16 buf_size,bool tx,bool auto_seq)249 void ___ieee80211_start_rx_ba_session(struct sta_info *sta,
250 u8 dialog_token, u16 timeout,
251 u16 start_seq_num, u16 ba_policy, u16 tid,
252 u16 buf_size, bool tx, bool auto_seq)
253 {
254 struct ieee80211_local *local = sta->sdata->local;
255 struct tid_ampdu_rx *tid_agg_rx;
256 struct ieee80211_ampdu_params params = {
257 .sta = &sta->sta,
258 .action = IEEE80211_AMPDU_RX_START,
259 .tid = tid,
260 .amsdu = false,
261 .timeout = timeout,
262 .ssn = start_seq_num,
263 };
264 int i, ret = -EOPNOTSUPP;
265 u16 status = WLAN_STATUS_REQUEST_DECLINED;
266
267 if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
268 ht_dbg(sta->sdata,
269 "STA %pM requests BA session on unsupported tid %d\n",
270 sta->sta.addr, tid);
271 goto end;
272 }
273
274 if (!sta->sta.ht_cap.ht_supported) {
275 ht_dbg(sta->sdata,
276 "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
277 sta->sta.addr, tid);
278 /* send a response anyway, it's an error case if we get here */
279 goto end;
280 }
281
282 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
283 ht_dbg(sta->sdata,
284 "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
285 sta->sta.addr, tid);
286 goto end;
287 }
288
289 /* sanity check for incoming parameters:
290 * check if configuration can support the BA policy
291 * and if buffer size does not exceeds max value */
292 /* XXX: check own ht delayed BA capability?? */
293 if (((ba_policy != 1) &&
294 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
295 (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
296 status = WLAN_STATUS_INVALID_QOS_PARAM;
297 ht_dbg_ratelimited(sta->sdata,
298 "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
299 sta->sta.addr, tid, ba_policy, buf_size);
300 goto end;
301 }
302 /* determine default buffer size */
303 if (buf_size == 0)
304 buf_size = IEEE80211_MAX_AMPDU_BUF;
305
306 /* make sure the size doesn't exceed the maximum supported by the hw */
307 if (buf_size > sta->sta.max_rx_aggregation_subframes)
308 buf_size = sta->sta.max_rx_aggregation_subframes;
309 params.buf_size = buf_size;
310
311 ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
312 buf_size, sta->sta.addr);
313
314 /* examine state machine */
315 lockdep_assert_held(&sta->ampdu_mlme.mtx);
316
317 if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
318 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
319 ht_dbg_ratelimited(sta->sdata,
320 "updated AddBA Req from %pM on tid %u\n",
321 sta->sta.addr, tid);
322 /* We have no API to update the timeout value in the
323 * driver so reject the timeout update.
324 */
325 status = WLAN_STATUS_REQUEST_DECLINED;
326 goto end;
327 }
328
329 ht_dbg_ratelimited(sta->sdata,
330 "unexpected AddBA Req from %pM on tid %u\n",
331 sta->sta.addr, tid);
332
333 /* delete existing Rx BA session on the same tid */
334 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
335 WLAN_STATUS_UNSPECIFIED_QOS,
336 false);
337 }
338
339 if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
340 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
341 ht_dbg(sta->sdata,
342 "Rx A-MPDU request on %pM tid %d result %d\n",
343 sta->sta.addr, tid, ret);
344 if (!ret)
345 status = WLAN_STATUS_SUCCESS;
346 goto end;
347 }
348
349 /* prepare A-MPDU MLME for Rx aggregation */
350 tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
351 if (!tid_agg_rx)
352 goto end;
353
354 spin_lock_init(&tid_agg_rx->reorder_lock);
355
356 /* rx timer */
357 setup_deferrable_timer(&tid_agg_rx->session_timer,
358 sta_rx_agg_session_timer_expired,
359 (unsigned long)&sta->timer_to_tid[tid]);
360
361 /* rx reorder timer */
362 setup_timer(&tid_agg_rx->reorder_timer,
363 sta_rx_agg_reorder_timer_expired,
364 (unsigned long)&sta->timer_to_tid[tid]);
365
366 /* prepare reordering buffer */
367 tid_agg_rx->reorder_buf =
368 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
369 tid_agg_rx->reorder_time =
370 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
371 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
372 kfree(tid_agg_rx->reorder_buf);
373 kfree(tid_agg_rx->reorder_time);
374 kfree(tid_agg_rx);
375 goto end;
376 }
377
378 for (i = 0; i < buf_size; i++)
379 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
380
381 ret = drv_ampdu_action(local, sta->sdata, ¶ms);
382 ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
383 sta->sta.addr, tid, ret);
384 if (ret) {
385 kfree(tid_agg_rx->reorder_buf);
386 kfree(tid_agg_rx->reorder_time);
387 kfree(tid_agg_rx);
388 goto end;
389 }
390
391 /* update data */
392 tid_agg_rx->ssn = start_seq_num;
393 tid_agg_rx->head_seq_num = start_seq_num;
394 tid_agg_rx->buf_size = buf_size;
395 tid_agg_rx->timeout = timeout;
396 tid_agg_rx->stored_mpdu_num = 0;
397 tid_agg_rx->auto_seq = auto_seq;
398 tid_agg_rx->started = false;
399 tid_agg_rx->reorder_buf_filtered = 0;
400 status = WLAN_STATUS_SUCCESS;
401
402 /* activate it for RX */
403 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
404
405 if (timeout) {
406 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
407 tid_agg_rx->last_rx = jiffies;
408 }
409
410 end:
411 if (status == WLAN_STATUS_SUCCESS) {
412 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
413 __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
414 sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
415 }
416
417 if (tx)
418 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
419 dialog_token, status, 1, buf_size,
420 timeout);
421 }
422
__ieee80211_start_rx_ba_session(struct sta_info * sta,u8 dialog_token,u16 timeout,u16 start_seq_num,u16 ba_policy,u16 tid,u16 buf_size,bool tx,bool auto_seq)423 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
424 u8 dialog_token, u16 timeout,
425 u16 start_seq_num, u16 ba_policy, u16 tid,
426 u16 buf_size, bool tx, bool auto_seq)
427 {
428 mutex_lock(&sta->ampdu_mlme.mtx);
429 ___ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
430 start_seq_num, ba_policy, tid,
431 buf_size, tx, auto_seq);
432 mutex_unlock(&sta->ampdu_mlme.mtx);
433 }
434
ieee80211_process_addba_request(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)435 void ieee80211_process_addba_request(struct ieee80211_local *local,
436 struct sta_info *sta,
437 struct ieee80211_mgmt *mgmt,
438 size_t len)
439 {
440 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
441 u8 dialog_token;
442
443 /* extract session parameters from addba request frame */
444 dialog_token = mgmt->u.action.u.addba_req.dialog_token;
445 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
446 start_seq_num =
447 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
448
449 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
450 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
451 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
452 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
453
454 __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
455 start_seq_num, ba_policy, tid,
456 buf_size, true, false);
457 }
458
ieee80211_manage_rx_ba_offl(struct ieee80211_vif * vif,const u8 * addr,unsigned int bit)459 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
460 const u8 *addr, unsigned int bit)
461 {
462 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
463 struct ieee80211_local *local = sdata->local;
464 struct sta_info *sta;
465
466 rcu_read_lock();
467 sta = sta_info_get_bss(sdata, addr);
468 if (!sta)
469 goto unlock;
470
471 set_bit(bit, sta->ampdu_mlme.tid_rx_manage_offl);
472 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
473 unlock:
474 rcu_read_unlock();
475 }
476 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
477
ieee80211_rx_ba_timer_expired(struct ieee80211_vif * vif,const u8 * addr,unsigned int tid)478 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
479 const u8 *addr, unsigned int tid)
480 {
481 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
482 struct ieee80211_local *local = sdata->local;
483 struct sta_info *sta;
484
485 rcu_read_lock();
486 sta = sta_info_get_bss(sdata, addr);
487 if (!sta)
488 goto unlock;
489
490 set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
491 ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
492
493 unlock:
494 rcu_read_unlock();
495 }
496 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);
497