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
ieee80211_free_tid_rx(struct rcu_head * h)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
___ieee80211_stop_rx_ba_session(struct sta_info * sta,u16 tid,u16 initiator,u16 reason,bool tx)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 = sta->ampdu_mlme.tid_rx[tid];
67
68 if (!tid_rx)
69 return;
70
71 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], NULL);
72
73 #ifdef CONFIG_MAC80211_HT_DEBUG
74 printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
75 sta->sta.addr, tid);
76 #endif /* CONFIG_MAC80211_HT_DEBUG */
77
78 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
79 &sta->sta, tid, NULL, 0))
80 printk(KERN_DEBUG "HW problem - can not stop rx "
81 "aggregation for tid %d\n", tid);
82
83 /* check if this is a self generated aggregation halt */
84 if (initiator == WLAN_BACK_RECIPIENT && tx)
85 ieee80211_send_delba(sta->sdata, sta->sta.addr,
86 tid, 0, reason);
87
88 del_timer_sync(&tid_rx->session_timer);
89 del_timer_sync(&tid_rx->reorder_timer);
90
91 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
92 }
93
__ieee80211_stop_rx_ba_session(struct sta_info * sta,u16 tid,u16 initiator,u16 reason,bool tx)94 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
95 u16 initiator, u16 reason, bool tx)
96 {
97 mutex_lock(&sta->ampdu_mlme.mtx);
98 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
99 mutex_unlock(&sta->ampdu_mlme.mtx);
100 }
101
102 /*
103 * After accepting the AddBA Request we activated a timer,
104 * resetting it after each frame that arrives from the originator.
105 */
sta_rx_agg_session_timer_expired(unsigned long data)106 static void sta_rx_agg_session_timer_expired(unsigned long data)
107 {
108 /* not an elegant detour, but there is no choice as the timer passes
109 * only one argument, and various sta_info are needed here, so init
110 * flow in sta_info_create gives the TID as data, while the timer_to_id
111 * array gives the sta through container_of */
112 u8 *ptid = (u8 *)data;
113 u8 *timer_to_id = ptid - *ptid;
114 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
115 timer_to_tid[0]);
116
117 #ifdef CONFIG_MAC80211_HT_DEBUG
118 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
119 #endif
120 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
121 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
122 }
123
sta_rx_agg_reorder_timer_expired(unsigned long data)124 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
125 {
126 u8 *ptid = (u8 *)data;
127 u8 *timer_to_id = ptid - *ptid;
128 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
129 timer_to_tid[0]);
130
131 rcu_read_lock();
132 ieee80211_release_reorder_timeout(sta, *ptid);
133 rcu_read_unlock();
134 }
135
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)136 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
137 u8 dialog_token, u16 status, u16 policy,
138 u16 buf_size, u16 timeout)
139 {
140 struct ieee80211_local *local = sdata->local;
141 struct sk_buff *skb;
142 struct ieee80211_mgmt *mgmt;
143 u16 capab;
144
145 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
146
147 if (!skb) {
148 printk(KERN_DEBUG "%s: failed to allocate buffer "
149 "for addba resp frame\n", sdata->name);
150 return;
151 }
152
153 skb_reserve(skb, local->hw.extra_tx_headroom);
154 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
155 memset(mgmt, 0, 24);
156 memcpy(mgmt->da, da, ETH_ALEN);
157 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
158 if (sdata->vif.type == NL80211_IFTYPE_AP ||
159 sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
160 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
161 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
162 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
163
164 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
165 IEEE80211_STYPE_ACTION);
166
167 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
168 mgmt->u.action.category = WLAN_CATEGORY_BACK;
169 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
170 mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
171
172 capab = (u16)(policy << 1); /* bit 1 aggregation policy */
173 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
174 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
175
176 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
177 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
178 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
179
180 ieee80211_tx_skb(sdata, skb);
181 }
182
ieee80211_process_addba_request(struct ieee80211_local * local,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)183 void ieee80211_process_addba_request(struct ieee80211_local *local,
184 struct sta_info *sta,
185 struct ieee80211_mgmt *mgmt,
186 size_t len)
187 {
188 struct tid_ampdu_rx *tid_agg_rx;
189 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
190 u8 dialog_token;
191 int ret = -EOPNOTSUPP;
192
193 /* extract session parameters from addba request frame */
194 dialog_token = mgmt->u.action.u.addba_req.dialog_token;
195 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
196 start_seq_num =
197 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
198
199 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
200 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
201 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
202 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
203
204 status = WLAN_STATUS_REQUEST_DECLINED;
205
206 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
207 #ifdef CONFIG_MAC80211_HT_DEBUG
208 printk(KERN_DEBUG "Suspend in progress. "
209 "Denying ADDBA request\n");
210 #endif
211 goto end_no_lock;
212 }
213
214 /* sanity check for incoming parameters:
215 * check if configuration can support the BA policy
216 * and if buffer size does not exceeds max value */
217 /* XXX: check own ht delayed BA capability?? */
218 if (((ba_policy != 1) &&
219 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
220 (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
221 status = WLAN_STATUS_INVALID_QOS_PARAM;
222 #ifdef CONFIG_MAC80211_HT_DEBUG
223 if (net_ratelimit())
224 printk(KERN_DEBUG "AddBA Req with bad params from "
225 "%pM on tid %u. policy %d, buffer size %d\n",
226 mgmt->sa, tid, ba_policy,
227 buf_size);
228 #endif /* CONFIG_MAC80211_HT_DEBUG */
229 goto end_no_lock;
230 }
231 /* determine default buffer size */
232 if (buf_size == 0)
233 buf_size = IEEE80211_MAX_AMPDU_BUF;
234
235 /* make sure the size doesn't exceed the maximum supported by the hw */
236 if (buf_size > local->hw.max_rx_aggregation_subframes)
237 buf_size = local->hw.max_rx_aggregation_subframes;
238
239 /* examine state machine */
240 mutex_lock(&sta->ampdu_mlme.mtx);
241
242 if (sta->ampdu_mlme.tid_rx[tid]) {
243 #ifdef CONFIG_MAC80211_HT_DEBUG
244 if (net_ratelimit())
245 printk(KERN_DEBUG "unexpected AddBA Req from "
246 "%pM on tid %u\n",
247 mgmt->sa, tid);
248 #endif /* CONFIG_MAC80211_HT_DEBUG */
249 goto end;
250 }
251
252 /* prepare A-MPDU MLME for Rx aggregation */
253 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
254 if (!tid_agg_rx) {
255 #ifdef CONFIG_MAC80211_HT_DEBUG
256 if (net_ratelimit())
257 printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
258 tid);
259 #endif
260 goto end;
261 }
262
263 spin_lock_init(&tid_agg_rx->reorder_lock);
264
265 /* rx timer */
266 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
267 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
268 init_timer(&tid_agg_rx->session_timer);
269
270 /* rx reorder timer */
271 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
272 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
273 init_timer(&tid_agg_rx->reorder_timer);
274
275 /* prepare reordering buffer */
276 tid_agg_rx->reorder_buf =
277 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
278 tid_agg_rx->reorder_time =
279 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
280 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
281 #ifdef CONFIG_MAC80211_HT_DEBUG
282 if (net_ratelimit())
283 printk(KERN_ERR "can not allocate reordering buffer "
284 "to tid %d\n", tid);
285 #endif
286 kfree(tid_agg_rx->reorder_buf);
287 kfree(tid_agg_rx->reorder_time);
288 kfree(tid_agg_rx);
289 goto end;
290 }
291
292 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
293 &sta->sta, tid, &start_seq_num, 0);
294 #ifdef CONFIG_MAC80211_HT_DEBUG
295 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
296 #endif /* CONFIG_MAC80211_HT_DEBUG */
297
298 if (ret) {
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 /* update data */
306 tid_agg_rx->dialog_token = dialog_token;
307 tid_agg_rx->ssn = start_seq_num;
308 tid_agg_rx->head_seq_num = start_seq_num;
309 tid_agg_rx->buf_size = buf_size;
310 tid_agg_rx->timeout = timeout;
311 tid_agg_rx->stored_mpdu_num = 0;
312 status = WLAN_STATUS_SUCCESS;
313
314 /* activate it for RX */
315 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
316
317 if (timeout)
318 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
319
320 end:
321 mutex_unlock(&sta->ampdu_mlme.mtx);
322
323 end_no_lock:
324 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
325 dialog_token, status, 1, buf_size, timeout);
326 }
327