xref: /linux/net/mac80211/agg-rx.c (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
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 
22 static void ___ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
23 					    u16 initiator, u16 reason,
24 					    bool from_timer)
25 {
26 	struct ieee80211_local *local = sta->local;
27 	struct tid_ampdu_rx *tid_rx;
28 	int i;
29 
30 	spin_lock_bh(&sta->lock);
31 
32 	/* check if TID is in operational state */
33 	if (!sta->ampdu_mlme.tid_active_rx[tid]) {
34 		spin_unlock_bh(&sta->lock);
35 		return;
36 	}
37 
38 	sta->ampdu_mlme.tid_active_rx[tid] = false;
39 
40 	tid_rx = sta->ampdu_mlme.tid_rx[tid];
41 
42 #ifdef CONFIG_MAC80211_HT_DEBUG
43 	printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
44 	       sta->sta.addr, tid);
45 #endif /* CONFIG_MAC80211_HT_DEBUG */
46 
47 	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
48 			     &sta->sta, tid, NULL))
49 		printk(KERN_DEBUG "HW problem - can not stop rx "
50 				"aggregation for tid %d\n", tid);
51 
52 	/* check if this is a self generated aggregation halt */
53 	if (initiator == WLAN_BACK_RECIPIENT)
54 		ieee80211_send_delba(sta->sdata, sta->sta.addr,
55 				     tid, 0, reason);
56 
57 	/* free the reordering buffer */
58 	for (i = 0; i < tid_rx->buf_size; i++) {
59 		if (tid_rx->reorder_buf[i]) {
60 			/* release the reordered frames */
61 			dev_kfree_skb(tid_rx->reorder_buf[i]);
62 			tid_rx->stored_mpdu_num--;
63 			tid_rx->reorder_buf[i] = NULL;
64 		}
65 	}
66 
67 	/* free resources */
68 	kfree(tid_rx->reorder_buf);
69 	kfree(tid_rx->reorder_time);
70 	sta->ampdu_mlme.tid_rx[tid] = NULL;
71 
72 	spin_unlock_bh(&sta->lock);
73 
74 	if (!from_timer)
75 		del_timer_sync(&tid_rx->session_timer);
76 	kfree(tid_rx);
77 }
78 
79 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
80 				    u16 initiator, u16 reason)
81 {
82 	___ieee80211_stop_rx_ba_session(sta, tid, initiator, reason, false);
83 }
84 
85 /*
86  * After accepting the AddBA Request we activated a timer,
87  * resetting it after each frame that arrives from the originator.
88  */
89 static void sta_rx_agg_session_timer_expired(unsigned long data)
90 {
91 	/* not an elegant detour, but there is no choice as the timer passes
92 	 * only one argument, and various sta_info are needed here, so init
93 	 * flow in sta_info_create gives the TID as data, while the timer_to_id
94 	 * array gives the sta through container_of */
95 	u8 *ptid = (u8 *)data;
96 	u8 *timer_to_id = ptid - *ptid;
97 	struct sta_info *sta = container_of(timer_to_id, struct sta_info,
98 					 timer_to_tid[0]);
99 
100 #ifdef CONFIG_MAC80211_HT_DEBUG
101 	printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
102 #endif
103 	___ieee80211_stop_rx_ba_session(sta, *ptid, WLAN_BACK_RECIPIENT,
104 					WLAN_REASON_QSTA_TIMEOUT, true);
105 }
106 
107 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
108 				      u8 dialog_token, u16 status, u16 policy,
109 				      u16 buf_size, u16 timeout)
110 {
111 	struct ieee80211_local *local = sdata->local;
112 	struct sk_buff *skb;
113 	struct ieee80211_mgmt *mgmt;
114 	u16 capab;
115 
116 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
117 
118 	if (!skb) {
119 		printk(KERN_DEBUG "%s: failed to allocate buffer "
120 		       "for addba resp frame\n", sdata->name);
121 		return;
122 	}
123 
124 	skb_reserve(skb, local->hw.extra_tx_headroom);
125 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
126 	memset(mgmt, 0, 24);
127 	memcpy(mgmt->da, da, ETH_ALEN);
128 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
129 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
130 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
131 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
132 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
133 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
134 
135 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
136 					  IEEE80211_STYPE_ACTION);
137 
138 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
139 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
140 	mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
141 	mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
142 
143 	capab = (u16)(policy << 1);	/* bit 1 aggregation policy */
144 	capab |= (u16)(tid << 2); 	/* bit 5:2 TID number */
145 	capab |= (u16)(buf_size << 6);	/* bit 15:6 max size of aggregation */
146 
147 	mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
148 	mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
149 	mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
150 
151 	ieee80211_tx_skb(sdata, skb);
152 }
153 
154 void ieee80211_process_addba_request(struct ieee80211_local *local,
155 				     struct sta_info *sta,
156 				     struct ieee80211_mgmt *mgmt,
157 				     size_t len)
158 {
159 	struct ieee80211_hw *hw = &local->hw;
160 	struct ieee80211_conf *conf = &hw->conf;
161 	struct tid_ampdu_rx *tid_agg_rx;
162 	u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
163 	u8 dialog_token;
164 	int ret = -EOPNOTSUPP;
165 
166 	/* extract session parameters from addba request frame */
167 	dialog_token = mgmt->u.action.u.addba_req.dialog_token;
168 	timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
169 	start_seq_num =
170 		le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
171 
172 	capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
173 	ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
174 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
175 	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
176 
177 	status = WLAN_STATUS_REQUEST_DECLINED;
178 
179 	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA)) {
180 #ifdef CONFIG_MAC80211_HT_DEBUG
181 		printk(KERN_DEBUG "Suspend in progress. "
182 		       "Denying ADDBA request\n");
183 #endif
184 		goto end_no_lock;
185 	}
186 
187 	/* sanity check for incoming parameters:
188 	 * check if configuration can support the BA policy
189 	 * and if buffer size does not exceeds max value */
190 	/* XXX: check own ht delayed BA capability?? */
191 	if (((ba_policy != 1) &&
192 	     (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
193 	    (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
194 		status = WLAN_STATUS_INVALID_QOS_PARAM;
195 #ifdef CONFIG_MAC80211_HT_DEBUG
196 		if (net_ratelimit())
197 			printk(KERN_DEBUG "AddBA Req with bad params from "
198 				"%pM on tid %u. policy %d, buffer size %d\n",
199 				mgmt->sa, tid, ba_policy,
200 				buf_size);
201 #endif /* CONFIG_MAC80211_HT_DEBUG */
202 		goto end_no_lock;
203 	}
204 	/* determine default buffer size */
205 	if (buf_size == 0) {
206 		struct ieee80211_supported_band *sband;
207 
208 		sband = local->hw.wiphy->bands[conf->channel->band];
209 		buf_size = IEEE80211_MIN_AMPDU_BUF;
210 		buf_size = buf_size << sband->ht_cap.ampdu_factor;
211 	}
212 
213 
214 	/* examine state machine */
215 	spin_lock_bh(&sta->lock);
216 
217 	if (sta->ampdu_mlme.tid_active_rx[tid]) {
218 #ifdef CONFIG_MAC80211_HT_DEBUG
219 		if (net_ratelimit())
220 			printk(KERN_DEBUG "unexpected AddBA Req from "
221 				"%pM on tid %u\n",
222 				mgmt->sa, tid);
223 #endif /* CONFIG_MAC80211_HT_DEBUG */
224 		goto end;
225 	}
226 
227 	/* prepare A-MPDU MLME for Rx aggregation */
228 	sta->ampdu_mlme.tid_rx[tid] =
229 			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
230 	if (!sta->ampdu_mlme.tid_rx[tid]) {
231 #ifdef CONFIG_MAC80211_HT_DEBUG
232 		if (net_ratelimit())
233 			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
234 					tid);
235 #endif
236 		goto end;
237 	}
238 	/* rx timer */
239 	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
240 				sta_rx_agg_session_timer_expired;
241 	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
242 				(unsigned long)&sta->timer_to_tid[tid];
243 	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
244 
245 	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
246 
247 	/* prepare reordering buffer */
248 	tid_agg_rx->reorder_buf =
249 		kcalloc(buf_size, sizeof(struct sk_buff *), GFP_ATOMIC);
250 	tid_agg_rx->reorder_time =
251 		kcalloc(buf_size, sizeof(unsigned long), GFP_ATOMIC);
252 	if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
253 #ifdef CONFIG_MAC80211_HT_DEBUG
254 		if (net_ratelimit())
255 			printk(KERN_ERR "can not allocate reordering buffer "
256 			       "to tid %d\n", tid);
257 #endif
258 		kfree(tid_agg_rx->reorder_buf);
259 		kfree(tid_agg_rx->reorder_time);
260 		kfree(sta->ampdu_mlme.tid_rx[tid]);
261 		sta->ampdu_mlme.tid_rx[tid] = NULL;
262 		goto end;
263 	}
264 
265 	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
266 			       &sta->sta, tid, &start_seq_num);
267 #ifdef CONFIG_MAC80211_HT_DEBUG
268 	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
269 #endif /* CONFIG_MAC80211_HT_DEBUG */
270 
271 	if (ret) {
272 		kfree(tid_agg_rx->reorder_buf);
273 		kfree(tid_agg_rx);
274 		sta->ampdu_mlme.tid_rx[tid] = NULL;
275 		goto end;
276 	}
277 
278 	/* change state and send addba resp */
279 	sta->ampdu_mlme.tid_active_rx[tid] = true;
280 	tid_agg_rx->dialog_token = dialog_token;
281 	tid_agg_rx->ssn = start_seq_num;
282 	tid_agg_rx->head_seq_num = start_seq_num;
283 	tid_agg_rx->buf_size = buf_size;
284 	tid_agg_rx->timeout = timeout;
285 	tid_agg_rx->stored_mpdu_num = 0;
286 	status = WLAN_STATUS_SUCCESS;
287 end:
288 	spin_unlock_bh(&sta->lock);
289 
290 end_no_lock:
291 	ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
292 				  dialog_token, status, 1, buf_size, timeout);
293 }
294