Merge branch 'for-linus' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.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 Intel Deutschland GmbH
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16
17 /**
18  * DOC: RX A-MPDU aggregation
19  *
20  * Aggregation on the RX side requires only implementing the
21  * @ampdu_action callback that is invoked to start/stop any
22  * block-ack sessions for RX aggregation.
23  *
24  * When RX aggregation is started by the peer, the driver is
25  * notified via @ampdu_action function, with the
26  * %IEEE80211_AMPDU_RX_START action, and may reject the request
27  * in which case a negative response is sent to the peer, if it
28  * accepts it a positive response is sent.
29  *
30  * While the session is active, the device/driver are required
31  * to de-aggregate frames and pass them up one by one to mac80211,
32  * which will handle the reorder buffer.
33  *
34  * When the aggregation session is stopped again by the peer or
35  * ourselves, the driver's @ampdu_action function will be called
36  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
37  * call must not fail.
38  */
39
40 #include <linux/ieee80211.h>
41 #include <linux/slab.h>
42 #include <linux/export.h>
43 #include <net/mac80211.h>
44 #include "ieee80211_i.h"
45 #include "driver-ops.h"
46
47 static void ieee80211_free_tid_rx(struct rcu_head *h)
48 {
49         struct tid_ampdu_rx *tid_rx =
50                 container_of(h, struct tid_ampdu_rx, rcu_head);
51         int i;
52
53         for (i = 0; i < tid_rx->buf_size; i++)
54                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
55         kfree(tid_rx->reorder_buf);
56         kfree(tid_rx->reorder_time);
57         kfree(tid_rx);
58 }
59
60 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
61                                      u16 initiator, u16 reason, bool tx)
62 {
63         struct ieee80211_local *local = sta->local;
64         struct tid_ampdu_rx *tid_rx;
65         struct ieee80211_ampdu_params params = {
66                 .sta = &sta->sta,
67                 .action = IEEE80211_AMPDU_RX_STOP,
68                 .tid = tid,
69                 .amsdu = false,
70                 .timeout = 0,
71                 .ssn = 0,
72         };
73
74         lockdep_assert_held(&sta->ampdu_mlme.mtx);
75
76         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
77                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
78
79         if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
80                 return;
81
82         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
83         __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
84
85         ht_dbg(sta->sdata,
86                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
87                sta->sta.addr, tid,
88                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
89                (int)reason);
90
91         if (drv_ampdu_action(local, sta->sdata, &params))
92                 sdata_info(sta->sdata,
93                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
94                            sta->sta.addr, tid);
95
96         /* check if this is a self generated aggregation halt */
97         if (initiator == WLAN_BACK_RECIPIENT && tx)
98                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
99                                      tid, WLAN_BACK_RECIPIENT, reason);
100
101         /*
102          * return here in case tid_rx is not assigned - which will happen if
103          * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
104          */
105         if (!tid_rx)
106                 return;
107
108         del_timer_sync(&tid_rx->session_timer);
109
110         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
111         spin_lock_bh(&tid_rx->reorder_lock);
112         tid_rx->removed = true;
113         spin_unlock_bh(&tid_rx->reorder_lock);
114         del_timer_sync(&tid_rx->reorder_timer);
115
116         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
117 }
118
119 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
120                                     u16 initiator, u16 reason, bool tx)
121 {
122         mutex_lock(&sta->ampdu_mlme.mtx);
123         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
124         mutex_unlock(&sta->ampdu_mlme.mtx);
125 }
126
127 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
128                                   const u8 *addr)
129 {
130         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
131         struct sta_info *sta;
132         int i;
133
134         rcu_read_lock();
135         sta = sta_info_get_bss(sdata, addr);
136         if (!sta) {
137                 rcu_read_unlock();
138                 return;
139         }
140
141         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
142                 if (ba_rx_bitmap & BIT(i))
143                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
144
145         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
146         rcu_read_unlock();
147 }
148 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
149
150 /*
151  * After accepting the AddBA Request we activated a timer,
152  * resetting it after each frame that arrives from the originator.
153  */
154 static void sta_rx_agg_session_timer_expired(unsigned long data)
155 {
156         /* not an elegant detour, but there is no choice as the timer passes
157          * only one argument, and various sta_info are needed here, so init
158          * flow in sta_info_create gives the TID as data, while the timer_to_id
159          * array gives the sta through container_of */
160         u8 *ptid = (u8 *)data;
161         u8 *timer_to_id = ptid - *ptid;
162         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
163                                          timer_to_tid[0]);
164         struct tid_ampdu_rx *tid_rx;
165         unsigned long timeout;
166
167         rcu_read_lock();
168         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
169         if (!tid_rx) {
170                 rcu_read_unlock();
171                 return;
172         }
173
174         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
175         if (time_is_after_jiffies(timeout)) {
176                 mod_timer(&tid_rx->session_timer, timeout);
177                 rcu_read_unlock();
178                 return;
179         }
180         rcu_read_unlock();
181
182         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
183                sta->sta.addr, (u16)*ptid);
184
185         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
186         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
187 }
188
189 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
190 {
191         u8 *ptid = (u8 *)data;
192         u8 *timer_to_id = ptid - *ptid;
193         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
194                         timer_to_tid[0]);
195
196         rcu_read_lock();
197         ieee80211_release_reorder_timeout(sta, *ptid);
198         rcu_read_unlock();
199 }
200
201 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
202                                       u8 dialog_token, u16 status, u16 policy,
203                                       u16 buf_size, u16 timeout)
204 {
205         struct ieee80211_local *local = sdata->local;
206         struct sk_buff *skb;
207         struct ieee80211_mgmt *mgmt;
208         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
209         u16 capab;
210
211         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
212         if (!skb)
213                 return;
214
215         skb_reserve(skb, local->hw.extra_tx_headroom);
216         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
217         memset(mgmt, 0, 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
265         int i, ret = -EOPNOTSUPP;
266         u16 status = WLAN_STATUS_REQUEST_DECLINED;
267
268         if (!sta->sta.ht_cap.ht_supported) {
269                 ht_dbg(sta->sdata,
270                        "STA %pM erroneously requests BA session on tid %d w/o QoS\n",
271                        sta->sta.addr, tid);
272                 /* send a response anyway, it's an error case if we get here */
273                 goto end_no_lock;
274         }
275
276         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
277                 ht_dbg(sta->sdata,
278                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
279                        sta->sta.addr, tid);
280                 goto end_no_lock;
281         }
282
283         /* sanity check for incoming parameters:
284          * check if configuration can support the BA policy
285          * and if buffer size does not exceeds max value */
286         /* XXX: check own ht delayed BA capability?? */
287         if (((ba_policy != 1) &&
288              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
289             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
290                 status = WLAN_STATUS_INVALID_QOS_PARAM;
291                 ht_dbg_ratelimited(sta->sdata,
292                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
293                                    sta->sta.addr, tid, ba_policy, buf_size);
294                 goto end_no_lock;
295         }
296         /* determine default buffer size */
297         if (buf_size == 0)
298                 buf_size = IEEE80211_MAX_AMPDU_BUF;
299
300         /* make sure the size doesn't exceed the maximum supported by the hw */
301         if (buf_size > local->hw.max_rx_aggregation_subframes)
302                 buf_size = local->hw.max_rx_aggregation_subframes;
303         params.buf_size = buf_size;
304
305         /* examine state machine */
306         mutex_lock(&sta->ampdu_mlme.mtx);
307
308         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
309                 ht_dbg_ratelimited(sta->sdata,
310                                    "unexpected AddBA Req from %pM on tid %u\n",
311                                    sta->sta.addr, tid);
312
313                 /* delete existing Rx BA session on the same tid */
314                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
315                                                 WLAN_STATUS_UNSPECIFIED_QOS,
316                                                 false);
317         }
318
319         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
320                 ret = drv_ampdu_action(local, sta->sdata, &params);
321                 ht_dbg(sta->sdata,
322                        "Rx A-MPDU request on %pM tid %d result %d\n",
323                        sta->sta.addr, tid, ret);
324                 if (!ret)
325                         status = WLAN_STATUS_SUCCESS;
326                 goto end;
327         }
328
329         /* prepare A-MPDU MLME for Rx aggregation */
330         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
331         if (!tid_agg_rx)
332                 goto end;
333
334         spin_lock_init(&tid_agg_rx->reorder_lock);
335
336         /* rx timer */
337         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
338         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
339         init_timer_deferrable(&tid_agg_rx->session_timer);
340
341         /* rx reorder timer */
342         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
343         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
344         init_timer(&tid_agg_rx->reorder_timer);
345
346         /* prepare reordering buffer */
347         tid_agg_rx->reorder_buf =
348                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
349         tid_agg_rx->reorder_time =
350                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
351         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
352                 kfree(tid_agg_rx->reorder_buf);
353                 kfree(tid_agg_rx->reorder_time);
354                 kfree(tid_agg_rx);
355                 goto end;
356         }
357
358         for (i = 0; i < buf_size; i++)
359                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
360
361         ret = drv_ampdu_action(local, sta->sdata, &params);
362         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
363                sta->sta.addr, tid, ret);
364         if (ret) {
365                 kfree(tid_agg_rx->reorder_buf);
366                 kfree(tid_agg_rx->reorder_time);
367                 kfree(tid_agg_rx);
368                 goto end;
369         }
370
371         /* update data */
372         tid_agg_rx->dialog_token = dialog_token;
373         tid_agg_rx->ssn = start_seq_num;
374         tid_agg_rx->head_seq_num = start_seq_num;
375         tid_agg_rx->buf_size = buf_size;
376         tid_agg_rx->timeout = timeout;
377         tid_agg_rx->stored_mpdu_num = 0;
378         tid_agg_rx->auto_seq = auto_seq;
379         tid_agg_rx->reorder_buf_filtered = 0;
380         status = WLAN_STATUS_SUCCESS;
381
382         /* activate it for RX */
383         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
384
385         if (timeout) {
386                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
387                 tid_agg_rx->last_rx = jiffies;
388         }
389
390 end:
391         if (status == WLAN_STATUS_SUCCESS)
392                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
393         mutex_unlock(&sta->ampdu_mlme.mtx);
394
395 end_no_lock:
396         if (tx)
397                 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
398                                           dialog_token, status, 1, buf_size,
399                                           timeout);
400 }
401
402 void ieee80211_process_addba_request(struct ieee80211_local *local,
403                                      struct sta_info *sta,
404                                      struct ieee80211_mgmt *mgmt,
405                                      size_t len)
406 {
407         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
408         u8 dialog_token;
409
410         /* extract session parameters from addba request frame */
411         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
412         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
413         start_seq_num =
414                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
415
416         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
417         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
418         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
419         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
420
421         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
422                                         start_seq_num, ba_policy, tid,
423                                         buf_size, true, false);
424 }
425
426 void ieee80211_start_rx_ba_session_offl(struct ieee80211_vif *vif,
427                                         const u8 *addr, u16 tid)
428 {
429         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
430         struct ieee80211_local *local = sdata->local;
431         struct ieee80211_rx_agg *rx_agg;
432         struct sk_buff *skb = dev_alloc_skb(0);
433
434         if (unlikely(!skb))
435                 return;
436
437         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
438         memcpy(&rx_agg->addr, addr, ETH_ALEN);
439         rx_agg->tid = tid;
440
441         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_START;
442         skb_queue_tail(&sdata->skb_queue, skb);
443         ieee80211_queue_work(&local->hw, &sdata->work);
444 }
445 EXPORT_SYMBOL(ieee80211_start_rx_ba_session_offl);
446
447 void ieee80211_stop_rx_ba_session_offl(struct ieee80211_vif *vif,
448                                        const u8 *addr, u16 tid)
449 {
450         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
451         struct ieee80211_local *local = sdata->local;
452         struct ieee80211_rx_agg *rx_agg;
453         struct sk_buff *skb = dev_alloc_skb(0);
454
455         if (unlikely(!skb))
456                 return;
457
458         rx_agg = (struct ieee80211_rx_agg *) &skb->cb;
459         memcpy(&rx_agg->addr, addr, ETH_ALEN);
460         rx_agg->tid = tid;
461
462         skb->pkt_type = IEEE80211_SDATA_QUEUE_RX_AGG_STOP;
463         skb_queue_tail(&sdata->skb_queue, skb);
464         ieee80211_queue_work(&local->hw, &sdata->work);
465 }
466 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session_offl);