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 <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);
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);
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));
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",
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,
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);
103 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
106 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
107 struct sta_info *sta = sta_info_get(sdata, addr);
110 for (i = 0; i < STA_TID_NUM; i++)
111 if (ba_rx_bitmap & BIT(i))
112 set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
114 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
116 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
119 * After accepting the AddBA Request we activated a timer,
120 * resetting it after each frame that arrives from the originator.
122 static void sta_rx_agg_session_timer_expired(unsigned long data)
124 /* not an elegant detour, but there is no choice as the timer passes
125 * only one argument, and various sta_info are needed here, so init
126 * flow in sta_info_create gives the TID as data, while the timer_to_id
127 * array gives the sta through container_of */
128 u8 *ptid = (u8 *)data;
129 u8 *timer_to_id = ptid - *ptid;
130 struct sta_info *sta = container_of(timer_to_id, struct sta_info,
133 #ifdef CONFIG_MAC80211_HT_DEBUG
134 printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
136 set_bit(*ptid, sta->ampdu_mlme.tid_rx_timer_expired);
137 ieee80211_queue_work(&sta->local->hw, &sta->ampdu_mlme.work);
140 static void sta_rx_agg_reorder_timer_expired(unsigned long data)
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,
148 ieee80211_release_reorder_timeout(sta, *ptid);
152 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
153 u8 dialog_token, u16 status, u16 policy,
154 u16 buf_size, u16 timeout)
156 struct ieee80211_local *local = sdata->local;
158 struct ieee80211_mgmt *mgmt;
161 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
164 printk(KERN_DEBUG "%s: failed to allocate buffer "
165 "for addba resp frame\n", sdata->name);
169 skb_reserve(skb, local->hw.extra_tx_headroom);
170 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
172 memcpy(mgmt->da, da, ETH_ALEN);
173 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
174 if (sdata->vif.type == NL80211_IFTYPE_AP ||
175 sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
176 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
177 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
178 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
180 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
181 IEEE80211_STYPE_ACTION);
183 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
184 mgmt->u.action.category = WLAN_CATEGORY_BACK;
185 mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
186 mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
188 capab = (u16)(policy << 1); /* bit 1 aggregation policy */
189 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
190 capab |= (u16)(buf_size << 6); /* bit 15:6 max size of aggregation */
192 mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
193 mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
194 mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
196 ieee80211_tx_skb(sdata, skb);
199 void ieee80211_process_addba_request(struct ieee80211_local *local,
200 struct sta_info *sta,
201 struct ieee80211_mgmt *mgmt,
204 struct tid_ampdu_rx *tid_agg_rx;
205 u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
207 int ret = -EOPNOTSUPP;
209 /* extract session parameters from addba request frame */
210 dialog_token = mgmt->u.action.u.addba_req.dialog_token;
211 timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
213 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
215 capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
216 ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
217 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
218 buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
220 status = WLAN_STATUS_REQUEST_DECLINED;
222 if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
223 #ifdef CONFIG_MAC80211_HT_DEBUG
224 printk(KERN_DEBUG "Suspend in progress. "
225 "Denying ADDBA request\n");
230 /* sanity check for incoming parameters:
231 * check if configuration can support the BA policy
232 * and if buffer size does not exceeds max value */
233 /* XXX: check own ht delayed BA capability?? */
234 if (((ba_policy != 1) &&
235 (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
236 (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
237 status = WLAN_STATUS_INVALID_QOS_PARAM;
238 #ifdef CONFIG_MAC80211_HT_DEBUG
240 printk(KERN_DEBUG "AddBA Req with bad params from "
241 "%pM on tid %u. policy %d, buffer size %d\n",
242 mgmt->sa, tid, ba_policy,
244 #endif /* CONFIG_MAC80211_HT_DEBUG */
247 /* determine default buffer size */
249 buf_size = IEEE80211_MAX_AMPDU_BUF;
251 /* make sure the size doesn't exceed the maximum supported by the hw */
252 if (buf_size > local->hw.max_rx_aggregation_subframes)
253 buf_size = local->hw.max_rx_aggregation_subframes;
255 /* examine state machine */
256 mutex_lock(&sta->ampdu_mlme.mtx);
258 if (sta->ampdu_mlme.tid_rx[tid]) {
259 #ifdef CONFIG_MAC80211_HT_DEBUG
261 printk(KERN_DEBUG "unexpected AddBA Req from "
264 #endif /* CONFIG_MAC80211_HT_DEBUG */
268 /* prepare A-MPDU MLME for Rx aggregation */
269 tid_agg_rx = kmalloc(sizeof(struct tid_ampdu_rx), GFP_KERNEL);
271 #ifdef CONFIG_MAC80211_HT_DEBUG
273 printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
279 spin_lock_init(&tid_agg_rx->reorder_lock);
282 tid_agg_rx->session_timer.function = sta_rx_agg_session_timer_expired;
283 tid_agg_rx->session_timer.data = (unsigned long)&sta->timer_to_tid[tid];
284 init_timer(&tid_agg_rx->session_timer);
286 /* rx reorder timer */
287 tid_agg_rx->reorder_timer.function = sta_rx_agg_reorder_timer_expired;
288 tid_agg_rx->reorder_timer.data = (unsigned long)&sta->timer_to_tid[tid];
289 init_timer(&tid_agg_rx->reorder_timer);
291 /* prepare reordering buffer */
292 tid_agg_rx->reorder_buf =
293 kcalloc(buf_size, sizeof(struct sk_buff *), GFP_KERNEL);
294 tid_agg_rx->reorder_time =
295 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
296 if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
297 #ifdef CONFIG_MAC80211_HT_DEBUG
299 printk(KERN_ERR "can not allocate reordering buffer "
302 kfree(tid_agg_rx->reorder_buf);
303 kfree(tid_agg_rx->reorder_time);
308 ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
309 &sta->sta, tid, &start_seq_num, 0);
310 #ifdef CONFIG_MAC80211_HT_DEBUG
311 printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
312 #endif /* CONFIG_MAC80211_HT_DEBUG */
315 kfree(tid_agg_rx->reorder_buf);
316 kfree(tid_agg_rx->reorder_time);
322 tid_agg_rx->dialog_token = dialog_token;
323 tid_agg_rx->ssn = start_seq_num;
324 tid_agg_rx->head_seq_num = start_seq_num;
325 tid_agg_rx->buf_size = buf_size;
326 tid_agg_rx->timeout = timeout;
327 tid_agg_rx->stored_mpdu_num = 0;
328 status = WLAN_STATUS_SUCCESS;
330 /* activate it for RX */
331 rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
334 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
337 mutex_unlock(&sta->ampdu_mlme.mtx);
340 ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
341 dialog_token, status, 1, buf_size, timeout);