GNU Linux-libre 4.14.266-gnu1
[releases.git] / net / mac80211 / agg-rx.c
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
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
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, &params))
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
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
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  */
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
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
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
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, &params);
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, &params);
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
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
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
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
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);