Merge branch 'master' of ssh://infradead/~/public_git/wireless-next into for-davem
[linux-2.6.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  *
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 /**
17  * DOC: RX A-MPDU aggregation
18  *
19  * Aggregation on the RX side requires only implementing the
20  * @ampdu_action callback that is invoked to start/stop any
21  * block-ack sessions for RX aggregation.
22  *
23  * When RX aggregation is started by the peer, the driver is
24  * notified via @ampdu_action function, with the
25  * %IEEE80211_AMPDU_RX_START action, and may reject the request
26  * in which case a negative response is sent to the peer, if it
27  * accepts it a positive response is sent.
28  *
29  * While the session is active, the device/driver are required
30  * to de-aggregate frames and pass them up one by one to mac80211,
31  * which will handle the reorder buffer.
32  *
33  * When the aggregation session is stopped again by the peer or
34  * ourselves, the driver's @ampdu_action function will be called
35  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
36  * call must not fail.
37  */
38
39 #include <linux/ieee80211.h>
40 #include <linux/slab.h>
41 #include <net/mac80211.h>
42 #include "ieee80211_i.h"
43 #include "driver-ops.h"
44
45 static void ieee80211_free_tid_rx(struct rcu_head *h)
46 {
47         struct tid_ampdu_rx *tid_rx =
48                 container_of(h, struct tid_ampdu_rx, rcu_head);
49         int i;
50
51         for (i = 0; i < tid_rx->buf_size; i++)
52                 dev_kfree_skb(tid_rx->reorder_buf[i]);
53         kfree(tid_rx->reorder_buf);
54         kfree(tid_rx->reorder_time);
55         kfree(tid_rx);
56 }
57
58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
59                                      u16 initiator, u16 reason, bool tx)
60 {
61         struct ieee80211_local *local = sta->local;
62         struct tid_ampdu_rx *tid_rx;
63
64         lockdep_assert_held(&sta->ampdu_mlme.mtx);
65
66         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
67                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
68
69         if (!tid_rx)
70                 return;
71
72         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
73
74 #ifdef CONFIG_MAC80211_HT_DEBUG
75         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
76                sta->sta.addr, tid);
77 #endif /* CONFIG_MAC80211_HT_DEBUG */
78
79         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
80                              &sta->sta, tid, NULL, 0))
81                 printk(KERN_DEBUG "HW problem - can not stop rx "
82                                 "aggregation for tid %d\n", tid);
83
84         /* check if this is a self generated aggregation halt */
85         if (initiator == WLAN_BACK_RECIPIENT && tx)
86                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
87                                      tid, 0, reason);
88
89         del_timer_sync(&tid_rx->session_timer);
90         del_timer_sync(&tid_rx->reorder_timer);
91
92         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
93 }
94
95 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
96                                     u16 initiator, u16 reason, bool tx)
97 {
98         mutex_lock(&sta->ampdu_mlme.mtx);
99         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
100         mutex_unlock(&sta->ampdu_mlme.mtx);
101 }
102
103 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
104                                   const u8 *addr)
105 {
106         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
107         struct sta_info *sta;
108         int i;
109
110         rcu_read_lock();
111         sta = sta_info_get(sdata, addr);
112         if (!sta) {
113                 rcu_read_unlock();
114                 return;
115         }
116
117         for (i = 0; i < STA_TID_NUM; i++)
118                 if (ba_rx_bitmap & BIT(i))
119                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
120
121         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
122         rcu_read_unlock();
123 }
124 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
125
126 /*
127  * After accepting the AddBA Request we activated a timer,
128  * resetting it after each frame that arrives from the originator.
129  */
130 static void sta_rx_agg_session_timer_expired(unsigned long data)
131 {
132         /* not an elegant detour, but there is no choice as the timer passes
133          * only one argument, and various sta_info are needed here, so init
134          * flow in sta_info_create gives the TID as data, while the timer_to_id
135          * array gives the sta through container_of */
136         u8 *ptid = (u8 *)data;
137         u8 *timer_to_id = ptid - *ptid;
138         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
139                                          timer_to_tid[0]);
140
141 #ifdef CONFIG_MAC80211_HT_DEBUG
142         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
143 #endif
144         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
145         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
146 }
147
148 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
149 {
150         u8 *ptid = (u8 *)data;
151         u8 *timer_to_id = ptid - *ptid;
152         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
153                         timer_to_tid[0]);
154
155         rcu_read_lock();
156         ieee80211_release_reorder_timeout(sta, *ptid);
157         rcu_read_unlock();
158 }
159
160 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
161                                       u8 dialog_token, u16 status, u16 policy,
162                                       u16 buf_size, u16 timeout)
163 {
164         struct ieee80211_local *local = sdata->local;
165         struct sk_buff *skb;
166         struct ieee80211_mgmt *mgmt;
167         u16 capab;
168
169         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
170         if (!skb)
171                 return;
172
173         skb_reserve(skb, local->hw.extra_tx_headroom);
174         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
175         memset(mgmt, 0, 24);
176         memcpy(mgmt->da, da, ETH_ALEN);
177         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
178         if (sdata->vif.type == NL80211_IFTYPE_AP ||
179             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
180                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
181         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
182                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
183
184         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
185                                           IEEE80211_STYPE_ACTION);
186
187         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
188         mgmt->u.action.category = WLAN_CATEGORY_BACK;
189         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
190         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
191
192         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
193         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
194         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
195
196         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
197         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
198         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
199
200         ieee80211_tx_skb(sdata, skb);
201 }
202
203 void ieee80211_process_addba_request(struct ieee80211_local *local,
204                                      struct sta_info *sta,
205                                      struct ieee80211_mgmt *mgmt,
206                                      size_t len)
207 {
208         struct tid_ampdu_rx *tid_agg_rx;
209         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
210         u8 dialog_token;
211         int ret = -EOPNOTSUPP;
212
213         /* extract session parameters from addba request frame */
214         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
215         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
216         start_seq_num =
217                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
218
219         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
220         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
221         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
222         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
223
224         status = WLAN_STATUS_REQUEST_DECLINED;
225
226         if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
227 #ifdef CONFIG_MAC80211_HT_DEBUG
228                 printk(KERN_DEBUG "Suspend in progress. "
229                        "Denying ADDBA request\n");
230 #endif
231                 goto end_no_lock;
232         }
233
234         /* sanity check for incoming parameters:
235          * check if configuration can support the BA policy
236          * and if buffer size does not exceeds max value */
237         /* XXX: check own ht delayed BA capability?? */
238         if (((ba_policy != 1) &&
239              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
240             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
241                 status = WLAN_STATUS_INVALID_QOS_PARAM;
242 #ifdef CONFIG_MAC80211_HT_DEBUG
243                 if (net_ratelimit())
244                         printk(KERN_DEBUG "AddBA Req with bad params from "
245                                 "%pM on tid %u. policy %d, buffer size %d\n",
246                                 mgmt->sa, tid, ba_policy,
247                                 buf_size);
248 #endif /* CONFIG_MAC80211_HT_DEBUG */
249                 goto end_no_lock;
250         }
251         /* determine default buffer size */
252         if (buf_size == 0)
253                 buf_size = IEEE80211_MAX_AMPDU_BUF;
254
255         /* make sure the size doesn't exceed the maximum supported by the hw */
256         if (buf_size > local->hw.max_rx_aggregation_subframes)
257                 buf_size = local->hw.max_rx_aggregation_subframes;
258
259         /* examine state machine */
260         mutex_lock(&sta->ampdu_mlme.mtx);
261
262         if (sta->ampdu_mlme.tid_rx[tid]) {
263 #ifdef CONFIG_MAC80211_HT_DEBUG
264                 if (net_ratelimit())
265                         printk(KERN_DEBUG "unexpected AddBA Req from "
266                                 "%pM on tid %u\n",
267                                 mgmt->sa, tid);
268 #endif /* CONFIG_MAC80211_HT_DEBUG */
269
270                 /* delete existing Rx BA session on the same tid */
271                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
272                                                 WLAN_STATUS_UNSPECIFIED_QOS,
273                                                 false);
274         }
275
276         /* prepare A-MPDU MLME for Rx aggregation */
277         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
278         if (!tid_agg_rx)
279                 goto end;
280
281         spin_lock_init(&tid_agg_rx->reorder_lock);
282
283         /* rx timer */
284         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
285         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
286         init_timer(&tid_agg_rx->session_timer);
287
288         /* rx reorder timer */
289         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
290         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
291         init_timer(&tid_agg_rx->reorder_timer);
292
293         /* prepare reordering buffer */
294         tid_agg_rx->reorder_buf =
295                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
296         tid_agg_rx->reorder_time =
297                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
298         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
299                 kfree(tid_agg_rx->reorder_buf);
300                 kfree(tid_agg_rx->reorder_time);
301                 kfree(tid_agg_rx);
302                 goto end;
303         }
304
305         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
306                                &sta->sta, tid, &start_seq_num, 0);
307 #ifdef CONFIG_MAC80211_HT_DEBUG
308         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
309 #endif /* CONFIG_MAC80211_HT_DEBUG */
310
311         if (ret) {
312                 kfree(tid_agg_rx->reorder_buf);
313                 kfree(tid_agg_rx->reorder_time);
314                 kfree(tid_agg_rx);
315                 goto end;
316         }
317
318         /* update data */
319         tid_agg_rx->dialog_token = dialog_token;
320         tid_agg_rx->ssn = start_seq_num;
321         tid_agg_rx->head_seq_num = start_seq_num;
322         tid_agg_rx->buf_size = buf_size;
323         tid_agg_rx->timeout = timeout;
324         tid_agg_rx->stored_mpdu_num = 0;
325         status = WLAN_STATUS_SUCCESS;
326
327         /* activate it for RX */
328         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
329
330         if (timeout)
331                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
332
333 end:
334         mutex_unlock(&sta->ampdu_mlme.mtx);
335
336 end_no_lock:
337         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
338                                   dialog_token, status, 1, buf_size, timeout);
339 }