xref: /linux/net/mac80211/ht.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
23 				  struct ieee80211_sta_ht_cap *ht_cap,
24 				  u16 flag)
25 {
26 	__le16 le_flag = cpu_to_le16(flag);
27 	if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
28 		if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
29 			ht_cap->cap &= ~flag;
30 	}
31 }
32 
33 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
34 				     struct ieee80211_sta_ht_cap *ht_cap)
35 {
36 	u8 *scaps = (u8 *)(&sdata->u.mgd.ht_capa.mcs.rx_mask);
37 	u8 *smask = (u8 *)(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
38 	int i;
39 
40 	if (sdata->vif.type != NL80211_IFTYPE_STATION) {
41 		/* AP interfaces call this code when adding new stations,
42 		 * so just silently ignore non station interfaces.
43 		 */
44 		return;
45 	}
46 
47 	/* NOTE:  If you add more over-rides here, update register_hw
48 	 * ht_capa_mod_msk logic in main.c as well.
49 	 * And, if this method can ever change ht_cap.ht_supported, fix
50 	 * the check in ieee80211_add_ht_ie.
51 	 */
52 
53 	/* check for HT over-rides, MCS rates first. */
54 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
55 		u8 m = smask[i];
56 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
57 		/* Add back rates that are supported */
58 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
59 	}
60 
61 	/* Force removal of HT-40 capabilities? */
62 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
63 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
64 
65 	/* Allow user to disable the max-AMSDU bit. */
66 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
67 
68 	/* Allow user to decrease AMPDU factor */
69 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
70 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
71 		u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
72 			& IEEE80211_HT_AMPDU_PARM_FACTOR;
73 		if (n < ht_cap->ampdu_factor)
74 			ht_cap->ampdu_factor = n;
75 	}
76 
77 	/* Allow the user to increase AMPDU density. */
78 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
79 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
80 		u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
81 			IEEE80211_HT_AMPDU_PARM_DENSITY)
82 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
83 		if (n > ht_cap->ampdu_density)
84 			ht_cap->ampdu_density = n;
85 	}
86 }
87 
88 
89 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
90 				       struct ieee80211_supported_band *sband,
91 				       struct ieee80211_ht_cap *ht_cap_ie,
92 				       struct ieee80211_sta_ht_cap *ht_cap)
93 {
94 	u8 ampdu_info, tx_mcs_set_cap;
95 	int i, max_tx_streams;
96 
97 	BUG_ON(!ht_cap);
98 
99 	memset(ht_cap, 0, sizeof(*ht_cap));
100 
101 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
102 		return;
103 
104 	ht_cap->ht_supported = true;
105 
106 	/*
107 	 * The bits listed in this expression should be
108 	 * the same for the peer and us, if the station
109 	 * advertises more then we can't use those thus
110 	 * we mask them out.
111 	 */
112 	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
113 		(sband->ht_cap.cap |
114 		 ~(IEEE80211_HT_CAP_LDPC_CODING |
115 		   IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
116 		   IEEE80211_HT_CAP_GRN_FLD |
117 		   IEEE80211_HT_CAP_SGI_20 |
118 		   IEEE80211_HT_CAP_SGI_40 |
119 		   IEEE80211_HT_CAP_DSSSCCK40));
120 	/*
121 	 * The STBC bits are asymmetric -- if we don't have
122 	 * TX then mask out the peer's RX and vice versa.
123 	 */
124 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
125 		ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
126 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
127 		ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
128 
129 	ampdu_info = ht_cap_ie->ampdu_params_info;
130 	ht_cap->ampdu_factor =
131 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
132 	ht_cap->ampdu_density =
133 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
134 
135 	/* own MCS TX capabilities */
136 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
137 
138 	/* Copy peer MCS TX capabilities, the driver might need them. */
139 	ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
140 
141 	/* can we TX with MCS rates? */
142 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
143 		return;
144 
145 	/* Counting from 0, therefore +1 */
146 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
147 		max_tx_streams =
148 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
149 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
150 	else
151 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
152 
153 	/*
154 	 * 802.11n-2009 20.3.5 / 20.6 says:
155 	 * - indices 0 to 7 and 32 are single spatial stream
156 	 * - 8 to 31 are multiple spatial streams using equal modulation
157 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
158 	 * - remainder are multiple spatial streams using unequal modulation
159 	 */
160 	for (i = 0; i < max_tx_streams; i++)
161 		ht_cap->mcs.rx_mask[i] =
162 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
163 
164 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
165 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
166 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
167 			ht_cap->mcs.rx_mask[i] =
168 				sband->ht_cap.mcs.rx_mask[i] &
169 					ht_cap_ie->mcs.rx_mask[i];
170 
171 	/* handle MCS rate 32 too */
172 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
173 		ht_cap->mcs.rx_mask[32/8] |= 1;
174 
175 	/*
176 	 * If user has specified capability over-rides, take care
177 	 * of that here.
178 	 */
179 	ieee80211_apply_htcap_overrides(sdata, ht_cap);
180 }
181 
182 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
183 {
184 	int i;
185 
186 	cancel_work_sync(&sta->ampdu_mlme.work);
187 
188 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
189 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
190 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
191 					       WLAN_REASON_QSTA_LEAVE_QBSS, tx);
192 	}
193 }
194 
195 void ieee80211_ba_session_work(struct work_struct *work)
196 {
197 	struct sta_info *sta =
198 		container_of(work, struct sta_info, ampdu_mlme.work);
199 	struct tid_ampdu_tx *tid_tx;
200 	int tid;
201 
202 	/*
203 	 * When this flag is set, new sessions should be
204 	 * blocked, and existing sessions will be torn
205 	 * down by the code that set the flag, so this
206 	 * need not run.
207 	 */
208 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
209 		return;
210 
211 	mutex_lock(&sta->ampdu_mlme.mtx);
212 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
213 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
214 			___ieee80211_stop_rx_ba_session(
215 				sta, tid, WLAN_BACK_RECIPIENT,
216 				WLAN_REASON_QSTA_TIMEOUT, true);
217 
218 		if (test_and_clear_bit(tid,
219 				       sta->ampdu_mlme.tid_rx_stop_requested))
220 			___ieee80211_stop_rx_ba_session(
221 				sta, tid, WLAN_BACK_RECIPIENT,
222 				WLAN_REASON_UNSPECIFIED, true);
223 
224 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
225 		if (tid_tx) {
226 			/*
227 			 * Assign it over to the normal tid_tx array
228 			 * where it "goes live".
229 			 */
230 			spin_lock_bh(&sta->lock);
231 
232 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
233 			/* could there be a race? */
234 			if (sta->ampdu_mlme.tid_tx[tid])
235 				kfree(tid_tx);
236 			else
237 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
238 			spin_unlock_bh(&sta->lock);
239 
240 			ieee80211_tx_ba_session_handle_start(sta, tid);
241 			continue;
242 		}
243 
244 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
245 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
246 						 &tid_tx->state))
247 			___ieee80211_stop_tx_ba_session(sta, tid,
248 							WLAN_BACK_INITIATOR,
249 							true);
250 	}
251 	mutex_unlock(&sta->ampdu_mlme.mtx);
252 }
253 
254 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
255 			  const u8 *da, u16 tid,
256 			  u16 initiator, u16 reason_code)
257 {
258 	struct ieee80211_local *local = sdata->local;
259 	struct sk_buff *skb;
260 	struct ieee80211_mgmt *mgmt;
261 	u16 params;
262 
263 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
264 	if (!skb)
265 		return;
266 
267 	skb_reserve(skb, local->hw.extra_tx_headroom);
268 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
269 	memset(mgmt, 0, 24);
270 	memcpy(mgmt->da, da, ETH_ALEN);
271 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
272 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
273 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
274 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
275 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
276 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
277 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
278 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
279 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
280 
281 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
282 					  IEEE80211_STYPE_ACTION);
283 
284 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
285 
286 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
287 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
288 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
289 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
290 
291 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
292 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
293 
294 	ieee80211_tx_skb_tid(sdata, skb, tid);
295 }
296 
297 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
298 			     struct sta_info *sta,
299 			     struct ieee80211_mgmt *mgmt, size_t len)
300 {
301 	u16 tid, params;
302 	u16 initiator;
303 
304 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
305 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
306 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
307 
308 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
309 			   mgmt->sa, initiator ? "initiator" : "recipient",
310 			   tid,
311 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
312 
313 	if (initiator == WLAN_BACK_INITIATOR)
314 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
315 					       true);
316 	else
317 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
318 					       true);
319 }
320 
321 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
322 			       enum ieee80211_smps_mode smps, const u8 *da,
323 			       const u8 *bssid)
324 {
325 	struct ieee80211_local *local = sdata->local;
326 	struct sk_buff *skb;
327 	struct ieee80211_mgmt *action_frame;
328 
329 	/* 27 = header + category + action + smps mode */
330 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
331 	if (!skb)
332 		return -ENOMEM;
333 
334 	skb_reserve(skb, local->hw.extra_tx_headroom);
335 	action_frame = (void *)skb_put(skb, 27);
336 	memcpy(action_frame->da, da, ETH_ALEN);
337 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
338 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
339 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
340 						  IEEE80211_STYPE_ACTION);
341 	action_frame->u.action.category = WLAN_CATEGORY_HT;
342 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
343 	switch (smps) {
344 	case IEEE80211_SMPS_AUTOMATIC:
345 	case IEEE80211_SMPS_NUM_MODES:
346 		WARN_ON(1);
347 	case IEEE80211_SMPS_OFF:
348 		action_frame->u.action.u.ht_smps.smps_control =
349 				WLAN_HT_SMPS_CONTROL_DISABLED;
350 		break;
351 	case IEEE80211_SMPS_STATIC:
352 		action_frame->u.action.u.ht_smps.smps_control =
353 				WLAN_HT_SMPS_CONTROL_STATIC;
354 		break;
355 	case IEEE80211_SMPS_DYNAMIC:
356 		action_frame->u.action.u.ht_smps.smps_control =
357 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
358 		break;
359 	}
360 
361 	/* we'll do more on status of this frame */
362 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
363 	ieee80211_tx_skb(sdata, skb);
364 
365 	return 0;
366 }
367 
368 void ieee80211_request_smps_work(struct work_struct *work)
369 {
370 	struct ieee80211_sub_if_data *sdata =
371 		container_of(work, struct ieee80211_sub_if_data,
372 			     u.mgd.request_smps_work);
373 
374 	mutex_lock(&sdata->u.mgd.mtx);
375 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
376 	mutex_unlock(&sdata->u.mgd.mtx);
377 }
378 
379 void ieee80211_request_smps(struct ieee80211_vif *vif,
380 			    enum ieee80211_smps_mode smps_mode)
381 {
382 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
383 
384 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
385 		return;
386 
387 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
388 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
389 
390 	sdata->u.mgd.driver_smps_mode = smps_mode;
391 
392 	ieee80211_queue_work(&sdata->local->hw,
393 			     &sdata->u.mgd.request_smps_work);
394 }
395 /* this might change ... don't want non-open drivers using it */
396 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
397