ipv6,mcast: always hold idev->lock before mca_lock
[linux-3.10.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 <linux/export.h>
42 #include <net/mac80211.h>
43 #include "ieee80211_i.h"
44 #include "driver-ops.h"
45
46 static void ieee80211_free_tid_rx(struct rcu_head *h)
47 {
48         struct tid_ampdu_rx *tid_rx =
49                 container_of(h, struct tid_ampdu_rx, rcu_head);
50         int i;
51
52         del_timer_sync(&tid_rx->reorder_timer);
53
54         for (i = 0; i < tid_rx->buf_size; i++)
55                 dev_kfree_skb(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
67         lockdep_assert_held(&sta->ampdu_mlme.mtx);
68
69         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
70                                         lockdep_is_held(&sta->ampdu_mlme.mtx));
71
72         if (!tid_rx)
73                 return;
74
75         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
76
77         ht_dbg(sta->sdata,
78                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
79                sta->sta.addr, tid,
80                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
81                (int)reason);
82
83         if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
84                              &sta->sta, tid, NULL, 0))
85                 sdata_info(sta->sdata,
86                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
87                            sta->sta.addr, tid);
88
89         /* check if this is a self generated aggregation halt */
90         if (initiator == WLAN_BACK_RECIPIENT && tx)
91                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
92                                      tid, WLAN_BACK_RECIPIENT, reason);
93
94         del_timer_sync(&tid_rx->session_timer);
95
96         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
97 }
98
99 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
100                                     u16 initiator, u16 reason, bool tx)
101 {
102         mutex_lock(&sta->ampdu_mlme.mtx);
103         ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
104         mutex_unlock(&sta->ampdu_mlme.mtx);
105 }
106
107 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
108                                   const u8 *addr)
109 {
110         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
111         struct sta_info *sta;
112         int i;
113
114         rcu_read_lock();
115         sta = sta_info_get_bss(sdata, addr);
116         if (!sta) {
117                 rcu_read_unlock();
118                 return;
119         }
120
121         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
122                 if (ba_rx_bitmap & BIT(i))
123                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
124
125         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
126         rcu_read_unlock();
127 }
128 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
129
130 /*
131  * After accepting the AddBA Request we activated a timer,
132  * resetting it after each frame that arrives from the originator.
133  */
134 static void sta_rx_agg_session_timer_expired(unsigned long data)
135 {
136         /* not an elegant detour, but there is no choice as the timer passes
137          * only one argument, and various sta_info are needed here, so init
138          * flow in sta_info_create gives the TID as data, while the timer_to_id
139          * array gives the sta through container_of */
140         u8 *ptid = (u8 *)data;
141         u8 *timer_to_id = ptid - *ptid;
142         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
143                                          timer_to_tid[0]);
144         struct tid_ampdu_rx *tid_rx;
145         unsigned long timeout;
146
147         rcu_read_lock();
148         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
149         if (!tid_rx) {
150                 rcu_read_unlock();
151                 return;
152         }
153
154         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
155         if (time_is_after_jiffies(timeout)) {
156                 mod_timer(&tid_rx->session_timer, timeout);
157                 rcu_read_unlock();
158                 return;
159         }
160         rcu_read_unlock();
161
162         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
163                sta->sta.addr, (u16)*ptid);
164
165         set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
166         ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
167 }
168
169 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
170 {
171         u8 *ptid = (u8 *)data;
172         u8 *timer_to_id = ptid - *ptid;
173         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
174                         timer_to_tid[0]);
175
176         rcu_read_lock();
177         ieee80211_release_reorder_timeout(sta, *ptid);
178         rcu_read_unlock();
179 }
180
181 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
182                                       u8 dialog_token, u16 status, u16 policy,
183                                       u16 buf_size, u16 timeout)
184 {
185         struct ieee80211_local *local = sdata->local;
186         struct sk_buff *skb;
187         struct ieee80211_mgmt *mgmt;
188         u16 capab;
189
190         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
191         if (!skb)
192                 return;
193
194         skb_reserve(skb, local->hw.extra_tx_headroom);
195         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
196         memset(mgmt, 0, 24);
197         memcpy(mgmt->da, da, ETH_ALEN);
198         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
199         if (sdata->vif.type == NL80211_IFTYPE_AP ||
200             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
201             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
202                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
203         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
204                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
205         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
206                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
207
208         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
209                                           IEEE80211_STYPE_ACTION);
210
211         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
212         mgmt->u.action.category = WLAN_CATEGORY_BACK;
213         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
214         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
215
216         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
217         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
218         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
219
220         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
221         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
222         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
223
224         ieee80211_tx_skb(sdata, skb);
225 }
226
227 void ieee80211_process_addba_request(struct ieee80211_local *local,
228                                      struct sta_info *sta,
229                                      struct ieee80211_mgmt *mgmt,
230                                      size_t len)
231 {
232         struct tid_ampdu_rx *tid_agg_rx;
233         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
234         u8 dialog_token;
235         int ret = -EOPNOTSUPP;
236
237         /* extract session parameters from addba request frame */
238         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
239         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
240         start_seq_num =
241                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
242
243         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
244         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
245         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
246         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
247
248         status = WLAN_STATUS_REQUEST_DECLINED;
249
250         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
251                 ht_dbg(sta->sdata,
252                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
253                        sta->sta.addr, tid);
254                 goto end_no_lock;
255         }
256
257         /* sanity check for incoming parameters:
258          * check if configuration can support the BA policy
259          * and if buffer size does not exceeds max value */
260         /* XXX: check own ht delayed BA capability?? */
261         if (((ba_policy != 1) &&
262              (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
263             (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
264                 status = WLAN_STATUS_INVALID_QOS_PARAM;
265                 ht_dbg_ratelimited(sta->sdata,
266                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
267                                    mgmt->sa, tid, ba_policy, buf_size);
268                 goto end_no_lock;
269         }
270         /* determine default buffer size */
271         if (buf_size == 0)
272                 buf_size = IEEE80211_MAX_AMPDU_BUF;
273
274         /* make sure the size doesn't exceed the maximum supported by the hw */
275         if (buf_size > local->hw.max_rx_aggregation_subframes)
276                 buf_size = local->hw.max_rx_aggregation_subframes;
277
278         /* examine state machine */
279         mutex_lock(&sta->ampdu_mlme.mtx);
280
281         if (sta->ampdu_mlme.tid_rx[tid]) {
282                 ht_dbg_ratelimited(sta->sdata,
283                                    "unexpected AddBA Req from %pM on tid %u\n",
284                                    mgmt->sa, tid);
285
286                 /* delete existing Rx BA session on the same tid */
287                 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
288                                                 WLAN_STATUS_UNSPECIFIED_QOS,
289                                                 false);
290         }
291
292         /* prepare A-MPDU MLME for Rx aggregation */
293         tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
294         if (!tid_agg_rx)
295                 goto end;
296
297         spin_lock_init(&tid_agg_rx->reorder_lock);
298
299         /* rx timer */
300         tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
301         tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
302         init_timer_deferrable(&tid_agg_rx->session_timer);
303
304         /* rx reorder timer */
305         tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
306         tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
307         init_timer(&tid_agg_rx->reorder_timer);
308
309         /* prepare reordering buffer */
310         tid_agg_rx->reorder_buf =
311                 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
312         tid_agg_rx->reorder_time =
313                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
314         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
315                 kfree(tid_agg_rx->reorder_buf);
316                 kfree(tid_agg_rx->reorder_time);
317                 kfree(tid_agg_rx);
318                 goto end;
319         }
320
321         ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
322                                &sta->sta, tid, &start_seq_num, 0);
323         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
324                sta->sta.addr, tid, ret);
325         if (ret) {
326                 kfree(tid_agg_rx->reorder_buf);
327                 kfree(tid_agg_rx->reorder_time);
328                 kfree(tid_agg_rx);
329                 goto end;
330         }
331
332         /* update data */
333         tid_agg_rx->dialog_token = dialog_token;
334         tid_agg_rx->ssn = start_seq_num;
335         tid_agg_rx->head_seq_num = start_seq_num;
336         tid_agg_rx->buf_size = buf_size;
337         tid_agg_rx->timeout = timeout;
338         tid_agg_rx->stored_mpdu_num = 0;
339         status = WLAN_STATUS_SUCCESS;
340
341         /* activate it for RX */
342         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
343
344         if (timeout) {
345                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
346                 tid_agg_rx->last_rx = jiffies;
347         }
348
349 end:
350         mutex_unlock(&sta->ampdu_mlme.mtx);
351
352 end_no_lock:
353         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
354                                   dialog_token, status, 1, buf_size, timeout);
355 }