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.
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
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"
46 static void ieee80211_free_tid_rx(struct rcu_head *h)
48 struct tid_ampdu_rx *tid_rx =
49 container_of(h, struct tid_ampdu_rx, rcu_head);
52 for (i = 0; i < tid_rx->buf_size; i++)
53 dev_kfree_skb(tid_rx->reorder_buf[i]);
54 kfree(tid_rx->reorder_buf);
55 kfree(tid_rx->reorder_time);
59 void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
60 u16 initiator, u16 reason, bool tx)
62 struct ieee80211_local *local = sta->local;
63 struct tid_ampdu_rx *tid_rx;
65 lockdep_assert_held(&sta->ampdu_mlme.mtx);
67 tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
68 lockdep_is_held(&sta->ampdu_mlme.mtx));
73 RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
75 #ifdef CONFIG_MAC80211_HT_DEBUG
76 printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
78 #endif /* CONFIG_MAC80211_HT_DEBUG */
80 if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
81 &sta->sta, tid, NULL, 0))
82 printk(KERN_DEBUG "HW problem - can not stop rx "
83 "aggregation for tid %d\n", tid);
85 /* check if this is a self generated aggregation halt */
86 if (initiator == WLAN_BACK_RECIPIENT && tx)
87 ieee80211_send_delba(sta->sdata, sta->sta.addr,
90 del_timer_sync(&tid_rx->session_timer);
92 /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
93 spin_lock_bh(&tid_rx->reorder_lock);
94 tid_rx->removed = true;
95 spin_unlock_bh(&tid_rx->reorder_lock);
96 del_timer_sync(&tid_rx->reorder_timer);
98 call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
101 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
102 u16 initiator, u16 reason, bool tx)
104 mutex_lock(&sta->ampdu_mlme.mtx);
105 ___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, tx);
106 mutex_unlock(&sta->ampdu_mlme.mtx);
109 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
112 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
113 struct sta_info *sta;
117 sta = sta_info_get(sdata, addr);
123 for (i = 0; i < STA_TID_NUM; i++)
124 if (ba_rx_bitmap & BIT(i))
125 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
127 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
130 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
133 * After accepting the AddBA Request we activated a timer,
134 * resetting it after each frame that arrives from the originator.
136 static void sta_rx_agg_session_timer_expired(unsigned long data)
138 /* not an elegant detour, but there is no choice as the timer passes
139 * only one argument, and various sta_info are needed here, so init
140 * flow in sta_info_create gives the TID as data, while the timer_to_id
141 * array gives the sta through container_of */
142 u8 *ptid = (u8 *)data;
143 u8 *timer_to_id = ptid - *ptid;
144 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
147 #ifdef CONFIG_MAC80211_HT_DEBUG
148 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
150 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
151 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
154 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
156 u8 *ptid = (u8 *)data;
157 u8 *timer_to_id = ptid - *ptid;
158 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
162 ieee80211_release_reorder_timeout(sta, *ptid);
166 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
167 u8 dialog_token, u16 status, u16 policy,
168 u16 buf_size, u16 timeout)
170 struct ieee80211_local *local = sdata->local;
172 struct ieee80211_mgmt *mgmt;
175 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
179 skb_reserve(skb, local->hw.extra_tx_headroom);
180 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
182 memcpy(mgmt->da, da, ETH_ALEN);
183 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
184 if (sdata->vif.type == NL80211_IFTYPE_AP ||
185 sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
186 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
187 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
188 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
190 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
191 IEEE80211_STYPE_ACTION);
193 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
194 mgmt->u.action.category = WLAN_CATEGORY_BACK;
195 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
196 mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
198 capab = (u16)(policy << 1); /* bit 1 aggregation policy */
199 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
200 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
202 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
203 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
204 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
206 ieee80211_tx_skb(sdata, skb);
209 void ieee80211_process_addba_request(struct ieee80211_local *local,
210 struct sta_info *sta,
211 struct ieee80211_mgmt *mgmt,
214 struct tid_ampdu_rx *tid_agg_rx;
215 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
217 int ret = -EOPNOTSUPP;
219 /* extract session parameters from addba request frame */
220 dialog_token = mgmt->u.action.u.addba_req.dialog_token;
221 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
223 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
225 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
226 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
227 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
228 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
230 status = WLAN_STATUS_REQUEST_DECLINED;
232 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
233 #ifdef CONFIG_MAC80211_HT_DEBUG
234 printk(KERN_DEBUG "Suspend in progress. "
235 "Denying ADDBA request\n");
240 /* sanity check for incoming parameters:
241 * check if configuration can support the BA policy
242 * and if buffer size does not exceeds max value */
243 /* XXX: check own ht delayed BA capability?? */
244 if (((ba_policy != 1) &&
245 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
246 (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
247 status = WLAN_STATUS_INVALID_QOS_PARAM;
248 #ifdef CONFIG_MAC80211_HT_DEBUG
250 printk(KERN_DEBUG "AddBA Req with bad params from "
251 "%pM on tid %u. policy %d, buffer size %d\n",
252 mgmt->sa, tid, ba_policy,
254 #endif /* CONFIG_MAC80211_HT_DEBUG */
257 /* determine default buffer size */
259 buf_size = IEEE80211_MAX_AMPDU_BUF;
261 /* make sure the size doesn't exceed the maximum supported by the hw */
262 if (buf_size > local->hw.max_rx_aggregation_subframes)
263 buf_size = local->hw.max_rx_aggregation_subframes;
265 /* examine state machine */
266 mutex_lock(&sta->ampdu_mlme.mtx);
268 if (sta->ampdu_mlme.tid_rx[tid]) {
269 #ifdef CONFIG_MAC80211_HT_DEBUG
271 printk(KERN_DEBUG "unexpected AddBA Req from "
274 #endif /* CONFIG_MAC80211_HT_DEBUG */
276 /* delete existing Rx BA session on the same tid */
277 ___ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
278 WLAN_STATUS_UNSPECIFIED_QOS,
282 /* prepare A-MPDU MLME for Rx aggregation */
283 tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
287 spin_lock_init(&tid_agg_rx->reorder_lock);
290 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
291 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
292 init_timer(&tid_agg_rx->session_timer);
294 /* rx reorder timer */
295 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
296 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
297 init_timer(&tid_agg_rx->reorder_timer);
299 /* prepare reordering buffer */
300 tid_agg_rx->reorder_buf =
301 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
302 tid_agg_rx->reorder_time =
303 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
304 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
305 kfree(tid_agg_rx->reorder_buf);
306 kfree(tid_agg_rx->reorder_time);
311 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
312 &sta->sta, tid, &start_seq_num, 0);
313 #ifdef CONFIG_MAC80211_HT_DEBUG
314 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
315 #endif /* CONFIG_MAC80211_HT_DEBUG */
318 kfree(tid_agg_rx->reorder_buf);
319 kfree(tid_agg_rx->reorder_time);
325 tid_agg_rx->dialog_token = dialog_token;
326 tid_agg_rx->ssn = start_seq_num;
327 tid_agg_rx->head_seq_num = start_seq_num;
328 tid_agg_rx->buf_size = buf_size;
329 tid_agg_rx->timeout = timeout;
330 tid_agg_rx->stored_mpdu_num = 0;
331 status = WLAN_STATUS_SUCCESS;
333 /* activate it for RX */
334 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
337 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
340 mutex_unlock(&sta->ampdu_mlme.mtx);
343 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
344 dialog_token, status, 1, buf_size, timeout);