summaryrefslogtreecommitdiffstats
path: root/net/mac80211/agg-rx.c
blob: 31bf2586fb84a59a0b8ce964c1717e2555a7ea65 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
/*
 * HT handling
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007-2010, Intel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/**
 * DOC: RX A-MPDU aggregation
 *
 * Aggregation on the RX side requires only implementing the
 * @ampdu_action callback that is invoked to start/stop any
 * block-ack sessions for RX aggregation.
 *
 * When RX aggregation is started by the peer, the driver is
 * notified via @ampdu_action function, with the
 * %IEEE80211_AMPDU_RX_START action, and may reject the request
 * in which case a negative response is sent to the peer, if it
 * accepts it a positive response is sent.
 *
 * While the session is active, the device/driver are required
 * to de-aggregate frames and pass them up one by one to mac80211,
 * which will handle the reorder buffer.
 *
 * When the aggregation session is stopped again by the peer or
 * ourselves, the driver's @ampdu_action function will be called
 * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
 * call must not fail.
 */

#include <linux/ieee80211.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"

static void ieee80211_free_tid_rx(struct rcu_head *h)
{
	struct tid_ampdu_rx *tid_rx =
		container_of(h, struct tid_ampdu_rx, rcu_head);
	int i;

	del_timer_sync(&tid_rx->reorder_timer);

	for (i = 0; i < tid_rx->buf_size; i++)
		dev_kfree_skb(tid_rx->reorder_buf[i]);
	kfree(tid_rx->reorder_buf);
	kfree(tid_rx->reorder_time);
	kfree(tid_rx);
}

void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
				     u16 initiator, u16 reason, bool tx)
{
	struct ieee80211_local *local = sta->local;
	struct tid_ampdu_rx *tid_rx;

	lockdep_assert_held(&sta->ampdu_mlme.mtx);

	tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
					lockdep_is_held(&sta->ampdu_mlme.mtx));

	if (!tid_rx)
		return;

	RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);

	ht_dbg(sta->sdata,
	       "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
	       sta->sta.addr, tid,
	       initiator == WLAN_BACK_RECIPIENT ? "recipient" : "inititator",
	       (int)reason);

	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
			     &sta->sta, tid, NULL, 0))
		sdata_info(sta->sdata,
			   "HW problem - can not stop rx aggregation for %pM tid %d\n",
			   sta->sta.addr, tid);

	/* check if this is a self generated aggregation halt */
	if (initiator == WLAN_BACK_RECIPIENT && tx)
		ieee80211_send_delba(sta->sdata, sta->sta.addr,
				     tid, WLAN_BACK_RECIPIENT, reason);

	del_timer_sync(&tid_rx->session_timer);

	call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
}

void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
				    u16 initiator, u16 reason, bool tx)
{
	mutex_lock(&sta->ampdu_mlme.mtx);
	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
	mutex_unlock(&sta->ampdu_mlme.mtx);
}

void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
				  const u8 *addr)
{
	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
	struct sta_info *sta;
	int i;

	rcu_read_lock();
	sta = sta_info_get_bss(sdata, addr);
	if (!sta) {
		rcu_read_unlock();
		return;
	}

	for (i = 0; i < IEEE80211_NUM_TIDS; i++)
		if (ba_rx_bitmap & BIT(i))
			set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);

	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
	rcu_read_unlock();
}
EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);

/*
 * After accepting the AddBA Request we activated a timer,
 * resetting it after each frame that arrives from the originator.
 */
static void sta_rx_agg_session_timer_expired(unsigned long data)
{
	/* not an elegant detour, but there is no choice as the timer passes
	 * only one argument, and various sta_info are needed here, so init
	 * flow in sta_info_create gives the TID as data, while the timer_to_id
	 * array gives the sta through container_of */
	u8 *ptid = (u8 *)data;
	u8 *timer_to_id = ptid - *ptid;
	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
					 timer_to_tid[0]);
	struct tid_ampdu_rx *tid_rx;
	unsigned long timeout;

	rcu_read_lock();
	tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[*ptid]);
	if (!tid_rx) {
		rcu_read_unlock();
		return;
	}

	timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
	if (time_is_after_jiffies(timeout)) {
		mod_timer(&tid_rx->session_timer, timeout);
		rcu_read_unlock();
		return;
	}
	rcu_read_unlock();

	ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
	       sta->sta.addr, (u16)*ptid);

	set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
	ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
}

static void sta_rx_agg_reorder_timer_expired(unsigned long data)
{
	u8 *ptid = (u8 *)data;
	u8 *timer_to_id = ptid - *ptid;
	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
			timer_to_tid[0]);

	rcu_read_lock();
	ieee80211_release_reorder_timeout(sta, *ptid);
	rcu_read_unlock();
}

static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
				      u8 dialog_token, u16 status, u16 policy,
				      u16 buf_size, u16 timeout)
{
	struct ieee80211_local *local = sdata->local;
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u16 capab;

	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
	if (!skb)
		return;

	skb_reserve(skb, local->hw.extra_tx_headroom);
	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
	memset(mgmt, 0, 24);
	memcpy(mgmt->da, da, ETH_ALEN);
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
	if (sdata->vif.type == NL80211_IFTYPE_AP ||
	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);

	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_ACTION);

	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
	mgmt->u.action.category = WLAN_CATEGORY_BACK;
	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;

	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */

	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);

	ieee80211_tx_skb(sdata, skb);
}

void ieee80211_process_addba_request(struct ieee80211_local *local,
				     struct sta_info *sta,
				     struct ieee80211_mgmt *mgmt,
				     size_t len)
{
	struct tid_ampdu_rx *tid_agg_rx;
	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
	u8 dialog_token;
	int ret = -EOPNOTSUPP;

	/* extract session parameters from addba request frame */
	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
	start_seq_num =
		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;

	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;

	status = WLAN_STATUS_REQUEST_DECLINED;

	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
		ht_dbg(sta->sdata,
		       "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
		       sta->sta.addr, tid);
		goto end_no_lock;
	}

	/* sanity check for incoming parameters:
	 * check if configuration can support the BA policy
	 * and if buffer size does not exceeds max value */
	/* XXX: check own ht delayed BA capability?? */
	if (((ba_policy != 1) &&
	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
		status = WLAN_STATUS_INVALID_QOS_PARAM;
		ht_dbg_ratelimited(sta->sdata,
				   "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
				   mgmt->sa, tid, ba_policy, buf_size);
		goto end_no_lock;
	}
	/* determine default buffer size */
	if (buf_size == 0)
		buf_size = IEEE80211_MAX_AMPDU_BUF;

	/* make sure the size doesn't exceed the maximum supported by the hw */
	if (buf_size > local->hw.max_rx_aggregation_subframes)
		buf_size = local->hw.max_rx_aggregation_subframes;

	/* examine state machine */
	mutex_lock(&sta->ampdu_mlme.mtx);

	if (sta->ampdu_mlme.tid_rx[tid]) {
		ht_dbg_ratelimited(sta->sdata,
				   "unexpected AddBA Req from %pM on tid %u\n",
				   mgmt->sa, tid);

		/* delete existing Rx BA session on the same tid */
		___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
						WLAN_STATUS_UNSPECIFIED_QOS,
						false);
	}

	/* prepare A-MPDU MLME for Rx aggregation */
	tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
	if (!tid_agg_rx)
		goto end;

	spin_lock_init(&tid_agg_rx->reorder_lock);

	/* rx timer */
	tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
	tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
	init_timer_deferrable(&tid_agg_rx->session_timer);

	/* rx reorder timer */
	tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
	tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
	init_timer(&tid_agg_rx->reorder_timer);

	/* prepare reordering buffer */
	tid_agg_rx->reorder_buf =
		kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
	tid_agg_rx->reorder_time =
		kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
		kfree(tid_agg_rx->reorder_buf);
		kfree(tid_agg_rx->reorder_time);
		kfree(tid_agg_rx);
		goto end;
	}

	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
			       &sta->sta, tid, &start_seq_num, 0);
	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
	       sta->sta.addr, tid, ret);
	if (ret) {
		kfree(tid_agg_rx->reorder_buf);
		kfree(tid_agg_rx->reorder_time);
		kfree(tid_agg_rx);
		goto end;
	}

	/* update data */
	tid_agg_rx->dialog_token = dialog_token;
	tid_agg_rx->ssn = start_seq_num;
	tid_agg_rx->head_seq_num = start_seq_num;
	tid_agg_rx->buf_size = buf_size;
	tid_agg_rx->timeout = timeout;
	tid_agg_rx->stored_mpdu_num = 0;
	status = WLAN_STATUS_SUCCESS;

	/* activate it for RX */
	rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);

	if (timeout) {
		mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
		tid_agg_rx->last_rx = jiffies;
	}

end:
	mutex_unlock(&sta->ampdu_mlme.mtx);

end_no_lock:
	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
				  dialog_token, status, 1, buf_size, timeout);
}
OpenPOWER on IntegriCloud