xref: /linux/net/mac80211/ht.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "rate.h"
20 
21 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
22 				       struct ieee80211_ht_cap *ht_cap_ie,
23 				       struct ieee80211_sta_ht_cap *ht_cap)
24 {
25 	u8 ampdu_info, tx_mcs_set_cap;
26 	int i, max_tx_streams;
27 
28 	BUG_ON(!ht_cap);
29 
30 	memset(ht_cap, 0, sizeof(*ht_cap));
31 
32 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
33 		return;
34 
35 	ht_cap->ht_supported = true;
36 
37 	/*
38 	 * The bits listed in this expression should be
39 	 * the same for the peer and us, if the station
40 	 * advertises more then we can't use those thus
41 	 * we mask them out.
42 	 */
43 	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
44 		(sband->ht_cap.cap |
45 		 ~(IEEE80211_HT_CAP_LDPC_CODING |
46 		   IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
47 		   IEEE80211_HT_CAP_GRN_FLD |
48 		   IEEE80211_HT_CAP_SGI_20 |
49 		   IEEE80211_HT_CAP_SGI_40 |
50 		   IEEE80211_HT_CAP_DSSSCCK40));
51 	/*
52 	 * The STBC bits are asymmetric -- if we don't have
53 	 * TX then mask out the peer's RX and vice versa.
54 	 */
55 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
56 		ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
57 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
58 		ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
59 
60 	ampdu_info = ht_cap_ie->ampdu_params_info;
61 	ht_cap->ampdu_factor =
62 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
63 	ht_cap->ampdu_density =
64 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
65 
66 	/* own MCS TX capabilities */
67 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
68 
69 	/* can we TX with MCS rates? */
70 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
71 		return;
72 
73 	/* Counting from 0, therefore +1 */
74 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
75 		max_tx_streams =
76 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
77 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
78 	else
79 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
80 
81 	/*
82 	 * 802.11n D5.0 20.3.5 / 20.6 says:
83 	 * - indices 0 to 7 and 32 are single spatial stream
84 	 * - 8 to 31 are multiple spatial streams using equal modulation
85 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
86 	 * - remainder are multiple spatial streams using unequal modulation
87 	 */
88 	for (i = 0; i < max_tx_streams; i++)
89 		ht_cap->mcs.rx_mask[i] =
90 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
91 
92 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
93 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
94 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
95 			ht_cap->mcs.rx_mask[i] =
96 				sband->ht_cap.mcs.rx_mask[i] &
97 					ht_cap_ie->mcs.rx_mask[i];
98 
99 	/* handle MCS rate 32 too */
100 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
101 		ht_cap->mcs.rx_mask[32/8] |= 1;
102 }
103 
104 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
105 {
106 	int i;
107 
108 	cancel_work_sync(&sta->ampdu_mlme.work);
109 
110 	for (i = 0; i <  STA_TID_NUM; i++) {
111 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
112 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
113 					       WLAN_REASON_QSTA_LEAVE_QBSS, tx);
114 	}
115 }
116 
117 void ieee80211_ba_session_work(struct work_struct *work)
118 {
119 	struct sta_info *sta =
120 		container_of(work, struct sta_info, ampdu_mlme.work);
121 	struct tid_ampdu_tx *tid_tx;
122 	int tid;
123 
124 	/*
125 	 * When this flag is set, new sessions should be
126 	 * blocked, and existing sessions will be torn
127 	 * down by the code that set the flag, so this
128 	 * need not run.
129 	 */
130 	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
131 		return;
132 
133 	mutex_lock(&sta->ampdu_mlme.mtx);
134 	for (tid = 0; tid < STA_TID_NUM; tid++) {
135 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
136 			___ieee80211_stop_rx_ba_session(
137 				sta, tid, WLAN_BACK_RECIPIENT,
138 				WLAN_REASON_QSTA_TIMEOUT, true);
139 
140 		tid_tx = sta->ampdu_mlme.tid_tx[tid];
141 		if (!tid_tx)
142 			continue;
143 
144 		if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state))
145 			ieee80211_tx_ba_session_handle_start(sta, tid);
146 		else if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
147 					    &tid_tx->state))
148 			___ieee80211_stop_tx_ba_session(sta, tid,
149 							WLAN_BACK_INITIATOR,
150 							true);
151 	}
152 	mutex_unlock(&sta->ampdu_mlme.mtx);
153 }
154 
155 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
156 			  const u8 *da, u16 tid,
157 			  u16 initiator, u16 reason_code)
158 {
159 	struct ieee80211_local *local = sdata->local;
160 	struct sk_buff *skb;
161 	struct ieee80211_mgmt *mgmt;
162 	u16 params;
163 
164 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
165 
166 	if (!skb) {
167 		printk(KERN_ERR "%s: failed to allocate buffer "
168 					"for delba frame\n", sdata->name);
169 		return;
170 	}
171 
172 	skb_reserve(skb, local->hw.extra_tx_headroom);
173 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
174 	memset(mgmt, 0, 24);
175 	memcpy(mgmt->da, da, ETH_ALEN);
176 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
177 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
178 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
179 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
180 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
181 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
182 
183 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
184 					  IEEE80211_STYPE_ACTION);
185 
186 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
187 
188 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
189 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
190 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
191 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
192 
193 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
194 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
195 
196 	ieee80211_tx_skb(sdata, skb);
197 }
198 
199 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
200 			     struct sta_info *sta,
201 			     struct ieee80211_mgmt *mgmt, size_t len)
202 {
203 	u16 tid, params;
204 	u16 initiator;
205 
206 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
207 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
208 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
209 
210 #ifdef CONFIG_MAC80211_HT_DEBUG
211 	if (net_ratelimit())
212 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
213 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
214 			le16_to_cpu(mgmt->u.action.u.delba.reason_code));
215 #endif /* CONFIG_MAC80211_HT_DEBUG */
216 
217 	if (initiator == WLAN_BACK_INITIATOR)
218 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
219 					       true);
220 	else
221 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
222 					       true);
223 }
224 
225 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
226 			       enum ieee80211_smps_mode smps, const u8 *da,
227 			       const u8 *bssid)
228 {
229 	struct ieee80211_local *local = sdata->local;
230 	struct sk_buff *skb;
231 	struct ieee80211_mgmt *action_frame;
232 
233 	/* 27 = header + category + action + smps mode */
234 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
235 	if (!skb)
236 		return -ENOMEM;
237 
238 	skb_reserve(skb, local->hw.extra_tx_headroom);
239 	action_frame = (void *)skb_put(skb, 27);
240 	memcpy(action_frame->da, da, ETH_ALEN);
241 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
242 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
243 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
244 						  IEEE80211_STYPE_ACTION);
245 	action_frame->u.action.category = WLAN_CATEGORY_HT;
246 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
247 	switch (smps) {
248 	case IEEE80211_SMPS_AUTOMATIC:
249 	case IEEE80211_SMPS_NUM_MODES:
250 		WARN_ON(1);
251 	case IEEE80211_SMPS_OFF:
252 		action_frame->u.action.u.ht_smps.smps_control =
253 				WLAN_HT_SMPS_CONTROL_DISABLED;
254 		break;
255 	case IEEE80211_SMPS_STATIC:
256 		action_frame->u.action.u.ht_smps.smps_control =
257 				WLAN_HT_SMPS_CONTROL_STATIC;
258 		break;
259 	case IEEE80211_SMPS_DYNAMIC:
260 		action_frame->u.action.u.ht_smps.smps_control =
261 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
262 		break;
263 	}
264 
265 	/* we'll do more on status of this frame */
266 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
267 	ieee80211_tx_skb(sdata, skb);
268 
269 	return 0;
270 }
271 
272 void ieee80211_request_smps_work(struct work_struct *work)
273 {
274 	struct ieee80211_sub_if_data *sdata =
275 		container_of(work, struct ieee80211_sub_if_data,
276 			     u.mgd.request_smps_work);
277 
278 	mutex_lock(&sdata->u.mgd.mtx);
279 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
280 	mutex_unlock(&sdata->u.mgd.mtx);
281 }
282 
283 void ieee80211_request_smps(struct ieee80211_vif *vif,
284 			    enum ieee80211_smps_mode smps_mode)
285 {
286 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
287 
288 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
289 		return;
290 
291 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
292 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
293 
294 	sdata->u.mgd.driver_smps_mode = smps_mode;
295 
296 	ieee80211_queue_work(&sdata->local->hw,
297 			     &sdata->u.mgd.request_smps_work);
298 }
299 /* this might change ... don't want non-open drivers using it */
300 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
301