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[linux-2.6/next.git] / net / mac80211 / agg-rx.c
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1 /*
2 * HT handling
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
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.
16 /**
17 * DOC: RX A-MPDU aggregation
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.
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.
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.
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.
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"
45 static void ieee80211_free_tid_rx(struct rcu_head *h)
47 struct tid_ampdu_rx *tid_rx =
48 container_of(h, struct tid_ampdu_rx, rcu_head);
49 int i;
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);
58 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
59 u16 initiator, u16 reason, bool tx)
61 struct ieee80211_local *local = sta->local;
62 struct tid_ampdu_rx *tid_rx;
64 lockdep_assert_held(&sta->ampdu_mlme.mtx);
66 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
67 lockdep_is_held(&sta->ampdu_mlme.mtx));
69 if (!tid_rx)
70 return;
72 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
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 */
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);
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);
89 del_timer_sync(&tid_rx->session_timer);
90 del_timer_sync(&tid_rx->reorder_timer);
92 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
95 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
96 u16 initiator, u16 reason, bool tx)
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);
104 * After accepting the AddBA Request we activated a timer,
105 * resetting it after each frame that arrives from the originator.
107 static void sta_rx_agg_session_timer_expired(unsigned long data)
109 /* not an elegant detour, but there is no choice as the timer passes
110 * only one argument, and various sta_info are needed here, so init
111 * flow in sta_info_create gives the TID as data, while the timer_to_id
112 * array gives the sta through container_of */
113 u8 *ptid = (u8 *)data;
114 u8 *timer_to_id = ptid - *ptid;
115 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
116 timer_to_tid[0]);
118 #ifdef CONFIG_MAC80211_HT_DEBUG
119 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
120 #endif
121 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
122 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
125 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
127 u8 *ptid = (u8 *)data;
128 u8 *timer_to_id = ptid - *ptid;
129 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
130 timer_to_tid[0]);
132 rcu_read_lock();
133 ieee80211_release_reorder_timeout(sta, *ptid);
134 rcu_read_unlock();
137 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
138 u8 dialog_token, u16 status, u16 policy,
139 u16 buf_size, u16 timeout)
141 struct ieee80211_local *local = sdata->local;
142 struct sk_buff *skb;
143 struct ieee80211_mgmt *mgmt;
144 u16 capab;
146 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
148 if (!skb) {
149 printk(KERN_DEBUG "%s: failed to allocate buffer "
150 "for addba resp frame\n", sdata->name);
151 return;
154 skb_reserve(skb, local->hw.extra_tx_headroom);
155 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
156 memset(mgmt, 0, 24);
157 memcpy(mgmt->da, da, ETH_ALEN);
158 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
159 if (sdata->vif.type == NL80211_IFTYPE_AP ||
160 sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
161 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
162 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
163 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
165 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
166 IEEE80211_STYPE_ACTION);
168 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
169 mgmt->u.action.category = WLAN_CATEGORY_BACK;
170 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
171 mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
173 capab = (u16)(policy << 1); /* bit 1 aggregation policy */
174 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
175 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
177 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
178 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
179 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
181 ieee80211_tx_skb(sdata, skb);
184 void ieee80211_process_addba_request(struct ieee80211_local *local,
185 struct sta_info *sta,
186 struct ieee80211_mgmt *mgmt,
187 size_t len)
189 struct tid_ampdu_rx *tid_agg_rx;
190 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
191 u8 dialog_token;
192 int ret = -EOPNOTSUPP;
194 /* extract session parameters from addba request frame */
195 dialog_token = mgmt->u.action.u.addba_req.dialog_token;
196 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
197 start_seq_num =
198 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
200 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
201 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
202 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
203 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
205 status = WLAN_STATUS_REQUEST_DECLINED;
207 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
208 #ifdef CONFIG_MAC80211_HT_DEBUG
209 printk(KERN_DEBUG "Suspend in progress. "
210 "Denying ADDBA request\n");
211 #endif
212 goto end_no_lock;
215 /* sanity check for incoming parameters:
216 * check if configuration can support the BA policy
217 * and if buffer size does not exceeds max value */
218 /* XXX: check own ht delayed BA capability?? */
219 if (((ba_policy != 1) &&
220 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
221 (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
222 status = WLAN_STATUS_INVALID_QOS_PARAM;
223 #ifdef CONFIG_MAC80211_HT_DEBUG
224 if (net_ratelimit())
225 printk(KERN_DEBUG "AddBA Req with bad params from "
226 "%pM on tid %u. policy %d, buffer size %d\n",
227 mgmt->sa, tid, ba_policy,
228 buf_size);
229 #endif /* CONFIG_MAC80211_HT_DEBUG */
230 goto end_no_lock;
232 /* determine default buffer size */
233 if (buf_size == 0)
234 buf_size = IEEE80211_MAX_AMPDU_BUF;
236 /* make sure the size doesn't exceed the maximum supported by the hw */
237 if (buf_size > local->hw.max_rx_aggregation_subframes)
238 buf_size = local->hw.max_rx_aggregation_subframes;
240 /* examine state machine */
241 mutex_lock(&sta->ampdu_mlme.mtx);
243 if (sta->ampdu_mlme.tid_rx[tid]) {
244 #ifdef CONFIG_MAC80211_HT_DEBUG
245 if (net_ratelimit())
246 printk(KERN_DEBUG "unexpected AddBA Req from "
247 "%pM on tid %u\n",
248 mgmt->sa, tid);
249 #endif /* CONFIG_MAC80211_HT_DEBUG */
250 goto end;
253 /* prepare A-MPDU MLME for Rx aggregation */
254 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
255 if (!tid_agg_rx) {
256 #ifdef CONFIG_MAC80211_HT_DEBUG
257 if (net_ratelimit())
258 printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
259 tid);
260 #endif
261 goto end;
264 spin_lock_init(&tid_agg_rx->reorder_lock);
266 /* rx timer */
267 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
268 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
269 init_timer(&tid_agg_rx->session_timer);
271 /* rx reorder timer */
272 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
273 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
274 init_timer(&tid_agg_rx->reorder_timer);
276 /* prepare reordering buffer */
277 tid_agg_rx->reorder_buf =
278 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
279 tid_agg_rx->reorder_time =
280 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
281 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
282 #ifdef CONFIG_MAC80211_HT_DEBUG
283 if (net_ratelimit())
284 printk(KERN_ERR "can not allocate reordering buffer "
285 "to tid %d\n", tid);
286 #endif
287 kfree(tid_agg_rx->reorder_buf);
288 kfree(tid_agg_rx->reorder_time);
289 kfree(tid_agg_rx);
290 goto end;
293 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
294 &sta->sta, tid, &start_seq_num, 0);
295 #ifdef CONFIG_MAC80211_HT_DEBUG
296 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
297 #endif /* CONFIG_MAC80211_HT_DEBUG */
299 if (ret) {
300 kfree(tid_agg_rx->reorder_buf);
301 kfree(tid_agg_rx->reorder_time);
302 kfree(tid_agg_rx);
303 goto end;
306 /* update data */
307 tid_agg_rx->dialog_token = dialog_token;
308 tid_agg_rx->ssn = start_seq_num;
309 tid_agg_rx->head_seq_num = start_seq_num;
310 tid_agg_rx->buf_size = buf_size;
311 tid_agg_rx->timeout = timeout;
312 tid_agg_rx->stored_mpdu_num = 0;
313 status = WLAN_STATUS_SUCCESS;
315 /* activate it for RX */
316 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
318 if (timeout)
319 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
321 end:
322 mutex_unlock(&sta->ampdu_mlme.mtx);
324 end_no_lock:
325 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
326 dialog_token, status, 1, buf_size, timeout);