xref: /openbmc/linux/net/mac80211/ht.c (revision 615c36f5)
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 2007-2010, 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/export.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "rate.h"
21 
22 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
23 				       struct ieee80211_ht_cap *ht_cap_ie,
24 				       struct ieee80211_sta_ht_cap *ht_cap)
25 {
26 	u8 ampdu_info, tx_mcs_set_cap;
27 	int i, max_tx_streams;
28 
29 	BUG_ON(!ht_cap);
30 
31 	memset(ht_cap, 0, sizeof(*ht_cap));
32 
33 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
34 		return;
35 
36 	ht_cap->ht_supported = true;
37 
38 	/*
39 	 * The bits listed in this expression should be
40 	 * the same for the peer and us, if the station
41 	 * advertises more then we can't use those thus
42 	 * we mask them out.
43 	 */
44 	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
45 		(sband->ht_cap.cap |
46 		 ~(IEEE80211_HT_CAP_LDPC_CODING |
47 		   IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
48 		   IEEE80211_HT_CAP_GRN_FLD |
49 		   IEEE80211_HT_CAP_SGI_20 |
50 		   IEEE80211_HT_CAP_SGI_40 |
51 		   IEEE80211_HT_CAP_DSSSCCK40));
52 	/*
53 	 * The STBC bits are asymmetric -- if we don't have
54 	 * TX then mask out the peer's RX and vice versa.
55 	 */
56 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
57 		ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
58 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
59 		ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
60 
61 	ampdu_info = ht_cap_ie->ampdu_params_info;
62 	ht_cap->ampdu_factor =
63 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
64 	ht_cap->ampdu_density =
65 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
66 
67 	/* own MCS TX capabilities */
68 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
69 
70 	/* Copy peer MCS TX capabilities, the driver might need them. */
71 	ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
72 
73 	/* can we TX with MCS rates? */
74 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
75 		return;
76 
77 	/* Counting from 0, therefore +1 */
78 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
79 		max_tx_streams =
80 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
81 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
82 	else
83 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
84 
85 	/*
86 	 * 802.11n-2009 20.3.5 / 20.6 says:
87 	 * - indices 0 to 7 and 32 are single spatial stream
88 	 * - 8 to 31 are multiple spatial streams using equal modulation
89 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
90 	 * - remainder are multiple spatial streams using unequal modulation
91 	 */
92 	for (i = 0; i < max_tx_streams; i++)
93 		ht_cap->mcs.rx_mask[i] =
94 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
95 
96 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
97 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
98 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
99 			ht_cap->mcs.rx_mask[i] =
100 				sband->ht_cap.mcs.rx_mask[i] &
101 					ht_cap_ie->mcs.rx_mask[i];
102 
103 	/* handle MCS rate 32 too */
104 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
105 		ht_cap->mcs.rx_mask[32/8] |= 1;
106 }
107 
108 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
109 {
110 	int i;
111 
112 	cancel_work_sync(&sta->ampdu_mlme.work);
113 
114 	for (i = 0; i <  STA_TID_NUM; i++) {
115 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
116 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
117 					       WLAN_REASON_QSTA_LEAVE_QBSS, tx);
118 	}
119 }
120 
121 void ieee80211_ba_session_work(struct work_struct *work)
122 {
123 	struct sta_info *sta =
124 		container_of(work, struct sta_info, ampdu_mlme.work);
125 	struct tid_ampdu_tx *tid_tx;
126 	int tid;
127 
128 	/*
129 	 * When this flag is set, new sessions should be
130 	 * blocked, and existing sessions will be torn
131 	 * down by the code that set the flag, so this
132 	 * need not run.
133 	 */
134 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
135 		return;
136 
137 	mutex_lock(&sta->ampdu_mlme.mtx);
138 	for (tid = 0; tid < STA_TID_NUM; tid++) {
139 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
140 			___ieee80211_stop_rx_ba_session(
141 				sta, tid, WLAN_BACK_RECIPIENT,
142 				WLAN_REASON_QSTA_TIMEOUT, true);
143 
144 		if (test_and_clear_bit(tid,
145 				       sta->ampdu_mlme.tid_rx_stop_requested))
146 			___ieee80211_stop_rx_ba_session(
147 				sta, tid, WLAN_BACK_RECIPIENT,
148 				WLAN_REASON_UNSPECIFIED, true);
149 
150 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
151 		if (tid_tx) {
152 			/*
153 			 * Assign it over to the normal tid_tx array
154 			 * where it "goes live".
155 			 */
156 			spin_lock_bh(&sta->lock);
157 
158 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
159 			/* could there be a race? */
160 			if (sta->ampdu_mlme.tid_tx[tid])
161 				kfree(tid_tx);
162 			else
163 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
164 			spin_unlock_bh(&sta->lock);
165 
166 			ieee80211_tx_ba_session_handle_start(sta, tid);
167 			continue;
168 		}
169 
170 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
171 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
172 						 &tid_tx->state))
173 			___ieee80211_stop_tx_ba_session(sta, tid,
174 							WLAN_BACK_INITIATOR,
175 							true);
176 	}
177 	mutex_unlock(&sta->ampdu_mlme.mtx);
178 }
179 
180 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
181 			  const u8 *da, u16 tid,
182 			  u16 initiator, u16 reason_code)
183 {
184 	struct ieee80211_local *local = sdata->local;
185 	struct sk_buff *skb;
186 	struct ieee80211_mgmt *mgmt;
187 	u16 params;
188 
189 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
190 	if (!skb)
191 		return;
192 
193 	skb_reserve(skb, local->hw.extra_tx_headroom);
194 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
195 	memset(mgmt, 0, 24);
196 	memcpy(mgmt->da, da, ETH_ALEN);
197 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
198 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
199 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
200 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
201 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
202 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
203 
204 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
205 					  IEEE80211_STYPE_ACTION);
206 
207 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
208 
209 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
210 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
211 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
212 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
213 
214 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
215 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
216 
217 	ieee80211_tx_skb(sdata, skb);
218 }
219 
220 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
221 			     struct sta_info *sta,
222 			     struct ieee80211_mgmt *mgmt, size_t len)
223 {
224 	u16 tid, params;
225 	u16 initiator;
226 
227 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
228 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
229 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
230 
231 #ifdef CONFIG_MAC80211_HT_DEBUG
232 	if (net_ratelimit())
233 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
234 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
235 			le16_to_cpu(mgmt->u.action.u.delba.reason_code));
236 #endif /* CONFIG_MAC80211_HT_DEBUG */
237 
238 	if (initiator == WLAN_BACK_INITIATOR)
239 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
240 					       true);
241 	else
242 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
243 					       true);
244 }
245 
246 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
247 			       enum ieee80211_smps_mode smps, const u8 *da,
248 			       const u8 *bssid)
249 {
250 	struct ieee80211_local *local = sdata->local;
251 	struct sk_buff *skb;
252 	struct ieee80211_mgmt *action_frame;
253 
254 	/* 27 = header + category + action + smps mode */
255 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
256 	if (!skb)
257 		return -ENOMEM;
258 
259 	skb_reserve(skb, local->hw.extra_tx_headroom);
260 	action_frame = (void *)skb_put(skb, 27);
261 	memcpy(action_frame->da, da, ETH_ALEN);
262 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
263 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
264 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
265 						  IEEE80211_STYPE_ACTION);
266 	action_frame->u.action.category = WLAN_CATEGORY_HT;
267 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
268 	switch (smps) {
269 	case IEEE80211_SMPS_AUTOMATIC:
270 	case IEEE80211_SMPS_NUM_MODES:
271 		WARN_ON(1);
272 	case IEEE80211_SMPS_OFF:
273 		action_frame->u.action.u.ht_smps.smps_control =
274 				WLAN_HT_SMPS_CONTROL_DISABLED;
275 		break;
276 	case IEEE80211_SMPS_STATIC:
277 		action_frame->u.action.u.ht_smps.smps_control =
278 				WLAN_HT_SMPS_CONTROL_STATIC;
279 		break;
280 	case IEEE80211_SMPS_DYNAMIC:
281 		action_frame->u.action.u.ht_smps.smps_control =
282 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
283 		break;
284 	}
285 
286 	/* we'll do more on status of this frame */
287 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
288 	ieee80211_tx_skb(sdata, skb);
289 
290 	return 0;
291 }
292 
293 void ieee80211_request_smps_work(struct work_struct *work)
294 {
295 	struct ieee80211_sub_if_data *sdata =
296 		container_of(work, struct ieee80211_sub_if_data,
297 			     u.mgd.request_smps_work);
298 
299 	mutex_lock(&sdata->u.mgd.mtx);
300 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
301 	mutex_unlock(&sdata->u.mgd.mtx);
302 }
303 
304 void ieee80211_request_smps(struct ieee80211_vif *vif,
305 			    enum ieee80211_smps_mode smps_mode)
306 {
307 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
308 
309 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
310 		return;
311 
312 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
313 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
314 
315 	sdata->u.mgd.driver_smps_mode = smps_mode;
316 
317 	ieee80211_queue_work(&sdata->local->hw,
318 			     &sdata->u.mgd.request_smps_work);
319 }
320 /* this might change ... don't want non-open drivers using it */
321 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
322