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 
ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band * sband,struct ieee80211_ht_cap * ht_cap_ie,struct ieee80211_sta_ht_cap * ht_cap)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 	/* Copy peer MCS TX capabilities, the driver might need them. */
70 	ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
71 
72 	/* can we TX with MCS rates? */
73 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
74 		return;
75 
76 	/* Counting from 0, therefore +1 */
77 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
78 		max_tx_streams =
79 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
80 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
81 	else
82 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
83 
84 	/*
85 	 * 802.11n-2009 20.3.5 / 20.6 says:
86 	 * - indices 0 to 7 and 32 are single spatial stream
87 	 * - 8 to 31 are multiple spatial streams using equal modulation
88 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
89 	 * - remainder are multiple spatial streams using unequal modulation
90 	 */
91 	for (i = 0; i < max_tx_streams; i++)
92 		ht_cap->mcs.rx_mask[i] =
93 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
94 
95 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
96 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
97 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
98 			ht_cap->mcs.rx_mask[i] =
99 				sband->ht_cap.mcs.rx_mask[i] &
100 					ht_cap_ie->mcs.rx_mask[i];
101 
102 	/* handle MCS rate 32 too */
103 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
104 		ht_cap->mcs.rx_mask[32/8] |= 1;
105 }
106 
ieee80211_sta_tear_down_BA_sessions(struct sta_info * sta,bool tx)107 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
108 {
109 	int i;
110 
111 	cancel_work_sync(&sta->ampdu_mlme.work);
112 
113 	for (i = 0; i <  STA_TID_NUM; i++) {
114 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
115 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
116 					       WLAN_REASON_QSTA_LEAVE_QBSS, tx);
117 	}
118 }
119 
ieee80211_ba_session_work(struct work_struct * work)120 void ieee80211_ba_session_work(struct work_struct *work)
121 {
122 	struct sta_info *sta =
123 		container_of(work, struct sta_info, ampdu_mlme.work);
124 	struct tid_ampdu_tx *tid_tx;
125 	int tid;
126 
127 	/*
128 	 * When this flag is set, new sessions should be
129 	 * blocked, and existing sessions will be torn
130 	 * down by the code that set the flag, so this
131 	 * need not run.
132 	 */
133 	if (test_sta_flags(sta, WLAN_STA_BLOCK_BA))
134 		return;
135 
136 	mutex_lock(&sta->ampdu_mlme.mtx);
137 	for (tid = 0; tid < STA_TID_NUM; tid++) {
138 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
139 			___ieee80211_stop_rx_ba_session(
140 				sta, tid, WLAN_BACK_RECIPIENT,
141 				WLAN_REASON_QSTA_TIMEOUT, true);
142 
143 		tid_tx = sta->ampdu_mlme.tid_tx[tid];
144 		if (!tid_tx)
145 			continue;
146 
147 		if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state))
148 			ieee80211_tx_ba_session_handle_start(sta, tid);
149 		else if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
150 					    &tid_tx->state))
151 			___ieee80211_stop_tx_ba_session(sta, tid,
152 							WLAN_BACK_INITIATOR,
153 							true);
154 	}
155 	mutex_unlock(&sta->ampdu_mlme.mtx);
156 }
157 
ieee80211_send_delba(struct ieee80211_sub_if_data * sdata,const u8 * da,u16 tid,u16 initiator,u16 reason_code)158 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
159 			  const u8 *da, u16 tid,
160 			  u16 initiator, u16 reason_code)
161 {
162 	struct ieee80211_local *local = sdata->local;
163 	struct sk_buff *skb;
164 	struct ieee80211_mgmt *mgmt;
165 	u16 params;
166 
167 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
168 
169 	if (!skb) {
170 		printk(KERN_ERR "%s: failed to allocate buffer "
171 					"for delba frame\n", sdata->name);
172 		return;
173 	}
174 
175 	skb_reserve(skb, local->hw.extra_tx_headroom);
176 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
177 	memset(mgmt, 0, 24);
178 	memcpy(mgmt->da, da, ETH_ALEN);
179 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
180 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
181 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
182 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
183 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
184 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
185 
186 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
187 					  IEEE80211_STYPE_ACTION);
188 
189 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
190 
191 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
192 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
193 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
194 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
195 
196 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
197 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
198 
199 	ieee80211_tx_skb(sdata, skb);
200 }
201 
ieee80211_process_delba(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)202 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
203 			     struct sta_info *sta,
204 			     struct ieee80211_mgmt *mgmt, size_t len)
205 {
206 	u16 tid, params;
207 	u16 initiator;
208 
209 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
210 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
211 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
212 
213 #ifdef CONFIG_MAC80211_HT_DEBUG
214 	if (net_ratelimit())
215 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
216 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
217 			le16_to_cpu(mgmt->u.action.u.delba.reason_code));
218 #endif /* CONFIG_MAC80211_HT_DEBUG */
219 
220 	if (initiator == WLAN_BACK_INITIATOR)
221 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
222 					       true);
223 	else
224 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
225 					       true);
226 }
227 
ieee80211_send_smps_action(struct ieee80211_sub_if_data * sdata,enum ieee80211_smps_mode smps,const u8 * da,const u8 * bssid)228 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
229 			       enum ieee80211_smps_mode smps, const u8 *da,
230 			       const u8 *bssid)
231 {
232 	struct ieee80211_local *local = sdata->local;
233 	struct sk_buff *skb;
234 	struct ieee80211_mgmt *action_frame;
235 
236 	/* 27 = header + category + action + smps mode */
237 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
238 	if (!skb)
239 		return -ENOMEM;
240 
241 	skb_reserve(skb, local->hw.extra_tx_headroom);
242 	action_frame = (void *)skb_put(skb, 27);
243 	memcpy(action_frame->da, da, ETH_ALEN);
244 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
245 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
246 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
247 						  IEEE80211_STYPE_ACTION);
248 	action_frame->u.action.category = WLAN_CATEGORY_HT;
249 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
250 	switch (smps) {
251 	case IEEE80211_SMPS_AUTOMATIC:
252 	case IEEE80211_SMPS_NUM_MODES:
253 		WARN_ON(1);
254 	case IEEE80211_SMPS_OFF:
255 		action_frame->u.action.u.ht_smps.smps_control =
256 				WLAN_HT_SMPS_CONTROL_DISABLED;
257 		break;
258 	case IEEE80211_SMPS_STATIC:
259 		action_frame->u.action.u.ht_smps.smps_control =
260 				WLAN_HT_SMPS_CONTROL_STATIC;
261 		break;
262 	case IEEE80211_SMPS_DYNAMIC:
263 		action_frame->u.action.u.ht_smps.smps_control =
264 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
265 		break;
266 	}
267 
268 	/* we'll do more on status of this frame */
269 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
270 	ieee80211_tx_skb(sdata, skb);
271 
272 	return 0;
273 }
274 
ieee80211_request_smps_work(struct work_struct * work)275 void ieee80211_request_smps_work(struct work_struct *work)
276 {
277 	struct ieee80211_sub_if_data *sdata =
278 		container_of(work, struct ieee80211_sub_if_data,
279 			     u.mgd.request_smps_work);
280 
281 	mutex_lock(&sdata->u.mgd.mtx);
282 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
283 	mutex_unlock(&sdata->u.mgd.mtx);
284 }
285 
ieee80211_request_smps(struct ieee80211_vif * vif,enum ieee80211_smps_mode smps_mode)286 void ieee80211_request_smps(struct ieee80211_vif *vif,
287 			    enum ieee80211_smps_mode smps_mode)
288 {
289 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
290 
291 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
292 		return;
293 
294 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
295 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
296 
297 	sdata->u.mgd.driver_smps_mode = smps_mode;
298 
299 	ieee80211_queue_work(&sdata->local->hw,
300 			     &sdata->u.mgd.request_smps_work);
301 }
302 /* this might change ... don't want non-open drivers using it */
303 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
304