xref: /openbmc/linux/net/mac80211/ht.c (revision 7fe2f639)
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 	/* 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 
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 
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_start_tx[tid];
144 		if (tid_tx) {
145 			/*
146 			 * Assign it over to the normal tid_tx array
147 			 * where it "goes live".
148 			 */
149 			spin_lock_bh(&sta->lock);
150 
151 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
152 			/* could there be a race? */
153 			if (sta->ampdu_mlme.tid_tx[tid])
154 				kfree(tid_tx);
155 			else
156 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
157 			spin_unlock_bh(&sta->lock);
158 
159 			ieee80211_tx_ba_session_handle_start(sta, tid);
160 			continue;
161 		}
162 
163 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
164 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
165 						 &tid_tx->state))
166 			___ieee80211_stop_tx_ba_session(sta, tid,
167 							WLAN_BACK_INITIATOR,
168 							true);
169 	}
170 	mutex_unlock(&sta->ampdu_mlme.mtx);
171 }
172 
173 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
174 			  const u8 *da, u16 tid,
175 			  u16 initiator, u16 reason_code)
176 {
177 	struct ieee80211_local *local = sdata->local;
178 	struct sk_buff *skb;
179 	struct ieee80211_mgmt *mgmt;
180 	u16 params;
181 
182 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
183 
184 	if (!skb) {
185 		printk(KERN_ERR "%s: failed to allocate buffer "
186 					"for delba frame\n", sdata->name);
187 		return;
188 	}
189 
190 	skb_reserve(skb, local->hw.extra_tx_headroom);
191 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
192 	memset(mgmt, 0, 24);
193 	memcpy(mgmt->da, da, ETH_ALEN);
194 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
195 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
196 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
197 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
198 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
199 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
200 
201 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
202 					  IEEE80211_STYPE_ACTION);
203 
204 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
205 
206 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
207 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
208 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
209 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
210 
211 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
212 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
213 
214 	ieee80211_tx_skb(sdata, skb);
215 }
216 
217 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
218 			     struct sta_info *sta,
219 			     struct ieee80211_mgmt *mgmt, size_t len)
220 {
221 	u16 tid, params;
222 	u16 initiator;
223 
224 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
225 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
226 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
227 
228 #ifdef CONFIG_MAC80211_HT_DEBUG
229 	if (net_ratelimit())
230 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
231 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
232 			le16_to_cpu(mgmt->u.action.u.delba.reason_code));
233 #endif /* CONFIG_MAC80211_HT_DEBUG */
234 
235 	if (initiator == WLAN_BACK_INITIATOR)
236 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
237 					       true);
238 	else
239 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
240 					       true);
241 }
242 
243 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
244 			       enum ieee80211_smps_mode smps, const u8 *da,
245 			       const u8 *bssid)
246 {
247 	struct ieee80211_local *local = sdata->local;
248 	struct sk_buff *skb;
249 	struct ieee80211_mgmt *action_frame;
250 
251 	/* 27 = header + category + action + smps mode */
252 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
253 	if (!skb)
254 		return -ENOMEM;
255 
256 	skb_reserve(skb, local->hw.extra_tx_headroom);
257 	action_frame = (void *)skb_put(skb, 27);
258 	memcpy(action_frame->da, da, ETH_ALEN);
259 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
260 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
261 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
262 						  IEEE80211_STYPE_ACTION);
263 	action_frame->u.action.category = WLAN_CATEGORY_HT;
264 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
265 	switch (smps) {
266 	case IEEE80211_SMPS_AUTOMATIC:
267 	case IEEE80211_SMPS_NUM_MODES:
268 		WARN_ON(1);
269 	case IEEE80211_SMPS_OFF:
270 		action_frame->u.action.u.ht_smps.smps_control =
271 				WLAN_HT_SMPS_CONTROL_DISABLED;
272 		break;
273 	case IEEE80211_SMPS_STATIC:
274 		action_frame->u.action.u.ht_smps.smps_control =
275 				WLAN_HT_SMPS_CONTROL_STATIC;
276 		break;
277 	case IEEE80211_SMPS_DYNAMIC:
278 		action_frame->u.action.u.ht_smps.smps_control =
279 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
280 		break;
281 	}
282 
283 	/* we'll do more on status of this frame */
284 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
285 	ieee80211_tx_skb(sdata, skb);
286 
287 	return 0;
288 }
289 
290 void ieee80211_request_smps_work(struct work_struct *work)
291 {
292 	struct ieee80211_sub_if_data *sdata =
293 		container_of(work, struct ieee80211_sub_if_data,
294 			     u.mgd.request_smps_work);
295 
296 	mutex_lock(&sdata->u.mgd.mtx);
297 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
298 	mutex_unlock(&sdata->u.mgd.mtx);
299 }
300 
301 void ieee80211_request_smps(struct ieee80211_vif *vif,
302 			    enum ieee80211_smps_mode smps_mode)
303 {
304 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
305 
306 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
307 		return;
308 
309 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
310 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
311 
312 	sdata->u.mgd.driver_smps_mode = smps_mode;
313 
314 	ieee80211_queue_work(&sdata->local->hw,
315 			     &sdata->u.mgd.request_smps_work);
316 }
317 /* this might change ... don't want non-open drivers using it */
318 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
319