/net/mac80211/agg-rx.c

  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 2007-2008, 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#include <linux/ieee80211.h>
 17#include <linux/slab.h>
 18#include <net/mac80211.h>
 19#include "ieee80211_i.h"
 20#include "driver-ops.h"
 21
 22void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
 23				    u16 initiator, u16 reason)
 24{
 25	struct ieee80211_local *local = sta->local;
 26	int i;
 27
 28	/* check if TID is in operational state */
 29	spin_lock_bh(&sta->lock);
 30	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL) {
 31		spin_unlock_bh(&sta->lock);
 32		return;
 33	}
 34
 35	sta->ampdu_mlme.tid_state_rx[tid] =
 36		HT_AGG_STATE_REQ_STOP_BA_MSK |
 37		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 38	spin_unlock_bh(&sta->lock);
 39
 40#ifdef CONFIG_MAC80211_HT_DEBUG
 41	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
 42	       sta->sta.addr, tid);
 43#endif /* CONFIG_MAC80211_HT_DEBUG */
 44
 45	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
 46			     &sta->sta, tid, NULL))
 47		printk(KERN_DEBUG "HW problem - can not stop rx "
 48				"aggregation for tid %d\n", tid);
 49
 50	/* shutdown timer has not expired */
 51	if (initiator != WLAN_BACK_TIMER)
 52		del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 53
 54	/* check if this is a self generated aggregation halt */
 55	if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
 56		ieee80211_send_delba(sta->sdata, sta->sta.addr,
 57				     tid, 0, reason);
 58
 59	/* free the reordering buffer */
 60	for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
 61		if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
 62			/* release the reordered frames */
 63			dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
 64			sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
 65			sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
 66		}
 67	}
 68
 69	spin_lock_bh(&sta->lock);
 70	/* free resources */
 71	kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
 72	kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_time);
 73
 74	if (!sta->ampdu_mlme.tid_rx[tid]->shutdown) {
 75		kfree(sta->ampdu_mlme.tid_rx[tid]);
 76		sta->ampdu_mlme.tid_rx[tid] = NULL;
 77	}
 78
 79	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
 80	spin_unlock_bh(&sta->lock);
 81}
 82
 83void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
 84					u16 initiator, u16 reason)
 85{
 86	struct sta_info *sta;
 87
 88	rcu_read_lock();
 89
 90	sta = sta_info_get(sdata, ra);
 91	if (!sta) {
 92		rcu_read_unlock();
 93		return;
 94	}
 95
 96	__ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
 97
 98	rcu_read_unlock();
 99}
100
101/*
102 * After accepting the AddBA Request we activated a timer,
103 * resetting it after each frame that arrives from the originator.
104 * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
105 */
106static 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	ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
121					 (u16)*ptid, WLAN_BACK_TIMER,
122					 WLAN_REASON_QSTA_TIMEOUT);
123}
124
125static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
126				      u8 dialog_token, u16 status, u16 policy,
127				      u16 buf_size, u16 timeout)
128{
129	struct ieee80211_local *local = sdata->local;
130	struct sk_buff *skb;
131	struct ieee80211_mgmt *mgmt;
132	u16 capab;
133
134	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
135
136	if (!skb) {
137		printk(KERN_DEBUG "%s: failed to allocate buffer "
138		       "for addba resp frame\n", sdata->name);
139		return;
140	}
141
142	skb_reserve(skb, local->hw.extra_tx_headroom);
143	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
144	memset(mgmt, 0, 24);
145	memcpy(mgmt->da, da, ETH_ALEN);
146	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
147	if (sdata->vif.type == NL80211_IFTYPE_AP ||
148	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
149		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
150	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
151		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
152
153	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
154					  IEEE80211_STYPE_ACTION);
155
156	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
157	mgmt->u.action.category = WLAN_CATEGORY_BACK;
158	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
159	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
160
161	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
162	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
163	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
164
165	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
166	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
167	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
168
169	ieee80211_tx_skb(sdata, skb);
170}
171
172void ieee80211_process_addba_request(struct ieee80211_local *local,
173				     struct sta_info *sta,
174				     struct ieee80211_mgmt *mgmt,
175				     size_t len)
176{
177	struct ieee80211_hw *hw = &local->hw;
178	struct ieee80211_conf *conf = &hw->conf;
179	struct tid_ampdu_rx *tid_agg_rx;
180	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
181	u8 dialog_token;
182	int ret = -EOPNOTSUPP;
183
184	/* extract session parameters from addba request frame */
185	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
186	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
187	start_seq_num =
188		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
189
190	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
191	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
192	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
193	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
194
195	status = WLAN_STATUS_REQUEST_DECLINED;
196
197	if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
198#ifdef CONFIG_MAC80211_HT_DEBUG
199		printk(KERN_DEBUG "Suspend in progress. "
200		       "Denying ADDBA request\n");
201#endif
202		goto end_no_lock;
203	}
204
205	/* sanity check for incoming parameters:
206	 * check if configuration can support the BA policy
207	 * and if buffer size does not exceeds max value */
208	/* XXX: check own ht delayed BA capability?? */
209	if (((ba_policy != 1) &&
210	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
211	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
212		status = WLAN_STATUS_INVALID_QOS_PARAM;
213#ifdef CONFIG_MAC80211_HT_DEBUG
214		if (net_ratelimit())
215			printk(KERN_DEBUG "AddBA Req with bad params from "
216				"%pM on tid %u. policy %d, buffer size %d\n",
217				mgmt->sa, tid, ba_policy,
218				buf_size);
219#endif /* CONFIG_MAC80211_HT_DEBUG */
220		goto end_no_lock;
221	}
222	/* determine default buffer size */
223	if (buf_size == 0) {
224		struct ieee80211_supported_band *sband;
225
226		sband = local->hw.wiphy->bands[conf->channel->band];
227		buf_size = IEEE80211_MIN_AMPDU_BUF;
228		buf_size = buf_size << sband->ht_cap.ampdu_factor;
229	}
230
231
232	/* examine state machine */
233	spin_lock_bh(&sta->lock);
234
235	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
236#ifdef CONFIG_MAC80211_HT_DEBUG
237		if (net_ratelimit())
238			printk(KERN_DEBUG "unexpected AddBA Req from "
239				"%pM on tid %u\n",
240				mgmt->sa, tid);
241#endif /* CONFIG_MAC80211_HT_DEBUG */
242		goto end;
243	}
244
245	/* prepare A-MPDU MLME for Rx aggregation */
246	sta->ampdu_mlme.tid_rx[tid] =
247			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
248	if (!sta->ampdu_mlme.tid_rx[tid]) {
249#ifdef CONFIG_MAC80211_HT_DEBUG
250		if (net_ratelimit())
251			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
252					tid);
253#endif
254		goto end;
255	}
256	/* rx timer */
257	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
258				sta_rx_agg_session_timer_expired;
259	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
260				(unsigned long)&sta->timer_to_tid[tid];
261	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
262
263	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
264
265	/* prepare reordering buffer */
266	tid_agg_rx->reorder_buf =
267		kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
268	tid_agg_rx->reorder_time =
269		kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
270	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
271#ifdef CONFIG_MAC80211_HT_DEBUG
272		if (net_ratelimit())
273			printk(KERN_ERR "can not allocate reordering buffer "
274			       "to tid %d\n", tid);
275#endif
276		kfree(tid_agg_rx->reorder_buf);
277		kfree(tid_agg_rx->reorder_time);
278		kfree(sta->ampdu_mlme.tid_rx[tid]);
279		sta->ampdu_mlme.tid_rx[tid] = NULL;
280		goto end;
281	}
282
283	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
284			       &sta->sta, tid, &start_seq_num);
285#ifdef CONFIG_MAC80211_HT_DEBUG
286	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
287#endif /* CONFIG_MAC80211_HT_DEBUG */
288
289	if (ret) {
290		kfree(tid_agg_rx->reorder_buf);
291		kfree(tid_agg_rx);
292		sta->ampdu_mlme.tid_rx[tid] = NULL;
293		goto end;
294	}
295
296	/* change state and send addba resp */
297	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
298	tid_agg_rx->dialog_token = dialog_token;
299	tid_agg_rx->ssn = start_seq_num;
300	tid_agg_rx->head_seq_num = start_seq_num;
301	tid_agg_rx->buf_size = buf_size;
302	tid_agg_rx->timeout = timeout;
303	tid_agg_rx->stored_mpdu_num = 0;
304	status = WLAN_STATUS_SUCCESS;
305end:
306	spin_unlock_bh(&sta->lock);
307
308end_no_lock:
309	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
310				  dialog_token, status, 1, buf_size, timeout);
311}