xref: /openbmc/linux/net/mac80211/agg-rx.c (revision b6dcefde)
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 <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "driver-ops.h"
20 
21 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
22 				    u16 initiator, u16 reason)
23 {
24 	struct ieee80211_local *local = sta->local;
25 	int i;
26 
27 	/* check if TID is in operational state */
28 	spin_lock_bh(&sta->lock);
29 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL) {
30 		spin_unlock_bh(&sta->lock);
31 		return;
32 	}
33 
34 	sta->ampdu_mlme.tid_state_rx[tid] =
35 		HT_AGG_STATE_REQ_STOP_BA_MSK |
36 		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
37 	spin_unlock_bh(&sta->lock);
38 
39 #ifdef CONFIG_MAC80211_HT_DEBUG
40 	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
41 	       sta->sta.addr, tid);
42 #endif /* CONFIG_MAC80211_HT_DEBUG */
43 
44 	if (drv_ampdu_action(local, &sta->sdata->vif,
45 			     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 
83 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
84 					u16 initiator, u16 reason)
85 {
86 	struct ieee80211_local *local = sdata->local;
87 	struct sta_info *sta;
88 
89 	rcu_read_lock();
90 
91 	sta = sta_info_get(local, ra);
92 	if (!sta) {
93 		rcu_read_unlock();
94 		return;
95 	}
96 
97 	__ieee80211_stop_rx_ba_session(sta, tid, initiator, reason);
98 
99 	rcu_read_unlock();
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  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
106  */
107 static void sta_rx_agg_session_timer_expired(unsigned long data)
108 {
109 	/* not an elegant detour, but there is no choice as the timer passes
110 	 * only one argument, and various sta_info are needed here, so init
111 	 * flow in sta_info_create gives the TID as data, while the timer_to_id
112 	 * array gives the sta through container_of */
113 	u8 *ptid = (u8 *)data;
114 	u8 *timer_to_id = ptid - *ptid;
115 	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
116 					 timer_to_tid[0]);
117 
118 #ifdef CONFIG_MAC80211_HT_DEBUG
119 	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
120 #endif
121 	ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
122 					 (u16)*ptid, WLAN_BACK_TIMER,
123 					 WLAN_REASON_QSTA_TIMEOUT);
124 }
125 
126 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
127 				      u8 dialog_token, u16 status, u16 policy,
128 				      u16 buf_size, u16 timeout)
129 {
130 	struct ieee80211_local *local = sdata->local;
131 	struct sk_buff *skb;
132 	struct ieee80211_mgmt *mgmt;
133 	u16 capab;
134 
135 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
136 
137 	if (!skb) {
138 		printk(KERN_DEBUG "%s: failed to allocate buffer "
139 		       "for addba resp frame\n", sdata->dev->name);
140 		return;
141 	}
142 
143 	skb_reserve(skb, local->hw.extra_tx_headroom);
144 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
145 	memset(mgmt, 0, 24);
146 	memcpy(mgmt->da, da, ETH_ALEN);
147 	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
148 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
149 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
150 		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
151 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
152 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
153 
154 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
155 					  IEEE80211_STYPE_ACTION);
156 
157 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
158 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
159 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
160 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
161 
162 	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
163 	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
164 	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
165 
166 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
167 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
168 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
169 
170 	ieee80211_tx_skb(sdata, skb);
171 }
172 
173 void ieee80211_process_addba_request(struct ieee80211_local *local,
174 				     struct sta_info *sta,
175 				     struct ieee80211_mgmt *mgmt,
176 				     size_t len)
177 {
178 	struct ieee80211_hw *hw = &local->hw;
179 	struct ieee80211_conf *conf = &hw->conf;
180 	struct tid_ampdu_rx *tid_agg_rx;
181 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
182 	u8 dialog_token;
183 	int ret = -EOPNOTSUPP;
184 
185 	/* extract session parameters from addba request frame */
186 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
187 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
188 	start_seq_num =
189 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
190 
191 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
192 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
193 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
194 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
195 
196 	status = WLAN_STATUS_REQUEST_DECLINED;
197 
198 	if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
199 #ifdef CONFIG_MAC80211_HT_DEBUG
200 		printk(KERN_DEBUG "Suspend in progress. "
201 		       "Denying ADDBA request\n");
202 #endif
203 		goto end_no_lock;
204 	}
205 
206 	/* sanity check for incoming parameters:
207 	 * check if configuration can support the BA policy
208 	 * and if buffer size does not exceeds max value */
209 	/* XXX: check own ht delayed BA capability?? */
210 	if (((ba_policy != 1) &&
211 	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
212 	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
213 		status = WLAN_STATUS_INVALID_QOS_PARAM;
214 #ifdef CONFIG_MAC80211_HT_DEBUG
215 		if (net_ratelimit())
216 			printk(KERN_DEBUG "AddBA Req with bad params from "
217 				"%pM on tid %u. policy %d, buffer size %d\n",
218 				mgmt->sa, tid, ba_policy,
219 				buf_size);
220 #endif /* CONFIG_MAC80211_HT_DEBUG */
221 		goto end_no_lock;
222 	}
223 	/* determine default buffer size */
224 	if (buf_size == 0) {
225 		struct ieee80211_supported_band *sband;
226 
227 		sband = local->hw.wiphy->bands[conf->channel->band];
228 		buf_size = IEEE80211_MIN_AMPDU_BUF;
229 		buf_size = buf_size << sband->ht_cap.ampdu_factor;
230 	}
231 
232 
233 	/* examine state machine */
234 	spin_lock_bh(&sta->lock);
235 
236 	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
237 #ifdef CONFIG_MAC80211_HT_DEBUG
238 		if (net_ratelimit())
239 			printk(KERN_DEBUG "unexpected AddBA Req from "
240 				"%pM on tid %u\n",
241 				mgmt->sa, tid);
242 #endif /* CONFIG_MAC80211_HT_DEBUG */
243 		goto end;
244 	}
245 
246 	/* prepare A-MPDU MLME for Rx aggregation */
247 	sta->ampdu_mlme.tid_rx[tid] =
248 			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
249 	if (!sta->ampdu_mlme.tid_rx[tid]) {
250 #ifdef CONFIG_MAC80211_HT_DEBUG
251 		if (net_ratelimit())
252 			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
253 					tid);
254 #endif
255 		goto end;
256 	}
257 	/* rx timer */
258 	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
259 				sta_rx_agg_session_timer_expired;
260 	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
261 				(unsigned long)&sta->timer_to_tid[tid];
262 	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
263 
264 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
265 
266 	/* prepare reordering buffer */
267 	tid_agg_rx->reorder_buf =
268 		kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
269 	tid_agg_rx->reorder_time =
270 		kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
271 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
272 #ifdef CONFIG_MAC80211_HT_DEBUG
273 		if (net_ratelimit())
274 			printk(KERN_ERR "can not allocate reordering buffer "
275 			       "to tid %d\n", tid);
276 #endif
277 		kfree(tid_agg_rx->reorder_buf);
278 		kfree(tid_agg_rx->reorder_time);
279 		kfree(sta->ampdu_mlme.tid_rx[tid]);
280 		sta->ampdu_mlme.tid_rx[tid] = NULL;
281 		goto end;
282 	}
283 
284 	ret = drv_ampdu_action(local, &sta->sdata->vif,
285 			       IEEE80211_AMPDU_RX_START,
286 			       &sta->sta, tid, &start_seq_num);
287 #ifdef CONFIG_MAC80211_HT_DEBUG
288 	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
289 #endif /* CONFIG_MAC80211_HT_DEBUG */
290 
291 	if (ret) {
292 		kfree(tid_agg_rx->reorder_buf);
293 		kfree(tid_agg_rx);
294 		sta->ampdu_mlme.tid_rx[tid] = NULL;
295 		goto end;
296 	}
297 
298 	/* change state and send addba resp */
299 	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
300 	tid_agg_rx->dialog_token = dialog_token;
301 	tid_agg_rx->ssn = start_seq_num;
302 	tid_agg_rx->head_seq_num = start_seq_num;
303 	tid_agg_rx->buf_size = buf_size;
304 	tid_agg_rx->timeout = timeout;
305 	tid_agg_rx->stored_mpdu_num = 0;
306 	status = WLAN_STATUS_SUCCESS;
307 end:
308 	spin_unlock_bh(&sta->lock);
309 
310 end_no_lock:
311 	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
312 				  dialog_token, status, 1, buf_size, timeout);
313 }
314