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 
ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data * sdata)22 bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata)
23 {
24 	const __le16 flg = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40);
25 	if ((sdata->u.mgd.ht_capa_mask.cap_info & flg) &&
26 	    !(sdata->u.mgd.ht_capa.cap_info & flg))
27 		return true;
28 	return false;
29 }
30 
__check_htcap_disable(struct ieee80211_sub_if_data * sdata,struct ieee80211_sta_ht_cap * ht_cap,u16 flag)31 static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
32 				  struct ieee80211_sta_ht_cap *ht_cap,
33 				  u16 flag)
34 {
35 	__le16 le_flag = cpu_to_le16(flag);
36 	if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
37 		if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
38 			ht_cap->cap &= ~flag;
39 	}
40 }
41 
ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data * sdata,struct ieee80211_sta_ht_cap * ht_cap)42 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
43 				     struct ieee80211_sta_ht_cap *ht_cap)
44 {
45 	u8 *scaps = (u8 *)(&sdata->u.mgd.ht_capa.mcs.rx_mask);
46 	u8 *smask = (u8 *)(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
47 	int i;
48 
49 	if (sdata->vif.type != NL80211_IFTYPE_STATION) {
50 		/* AP interfaces call this code when adding new stations,
51 		 * so just silently ignore non station interfaces.
52 		 */
53 		return;
54 	}
55 
56 	/* NOTE:  If you add more over-rides here, update register_hw
57 	 * ht_capa_mod_msk logic in main.c as well.
58 	 * And, if this method can ever change ht_cap.ht_supported, fix
59 	 * the check in ieee80211_add_ht_ie.
60 	 */
61 
62 	/* check for HT over-rides, MCS rates first. */
63 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
64 		u8 m = smask[i];
65 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
66 		/* Add back rates that are supported */
67 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
68 	}
69 
70 	/* Force removal of HT-40 capabilities? */
71 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
72 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
73 
74 	/* Allow user to disable the max-AMSDU bit. */
75 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
76 
77 	/* Allow user to decrease AMPDU factor */
78 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
79 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
80 		u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
81 			& IEEE80211_HT_AMPDU_PARM_FACTOR;
82 		if (n < ht_cap->ampdu_factor)
83 			ht_cap->ampdu_factor = n;
84 	}
85 
86 	/* Allow the user to increase AMPDU density. */
87 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
88 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
89 		u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
90 			IEEE80211_HT_AMPDU_PARM_DENSITY)
91 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
92 		if (n > ht_cap->ampdu_density)
93 			ht_cap->ampdu_density = n;
94 	}
95 }
96 
97 
ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data * sdata,struct ieee80211_supported_band * sband,struct ieee80211_ht_cap * ht_cap_ie,struct ieee80211_sta_ht_cap * ht_cap)98 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
99 				       struct ieee80211_supported_band *sband,
100 				       struct ieee80211_ht_cap *ht_cap_ie,
101 				       struct ieee80211_sta_ht_cap *ht_cap)
102 {
103 	u8 ampdu_info, tx_mcs_set_cap;
104 	int i, max_tx_streams;
105 
106 	BUG_ON(!ht_cap);
107 
108 	memset(ht_cap, 0, sizeof(*ht_cap));
109 
110 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
111 		return;
112 
113 	ht_cap->ht_supported = true;
114 
115 	/*
116 	 * The bits listed in this expression should be
117 	 * the same for the peer and us, if the station
118 	 * advertises more then we can't use those thus
119 	 * we mask them out.
120 	 */
121 	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
122 		(sband->ht_cap.cap |
123 		 ~(IEEE80211_HT_CAP_LDPC_CODING |
124 		   IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
125 		   IEEE80211_HT_CAP_GRN_FLD |
126 		   IEEE80211_HT_CAP_SGI_20 |
127 		   IEEE80211_HT_CAP_SGI_40 |
128 		   IEEE80211_HT_CAP_DSSSCCK40));
129 	/*
130 	 * The STBC bits are asymmetric -- if we don't have
131 	 * TX then mask out the peer's RX and vice versa.
132 	 */
133 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
134 		ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
135 	if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
136 		ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
137 
138 	ampdu_info = ht_cap_ie->ampdu_params_info;
139 	ht_cap->ampdu_factor =
140 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
141 	ht_cap->ampdu_density =
142 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
143 
144 	/* own MCS TX capabilities */
145 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
146 
147 	/* Copy peer MCS TX capabilities, the driver might need them. */
148 	ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
149 
150 	/* can we TX with MCS rates? */
151 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
152 		return;
153 
154 	/* Counting from 0, therefore +1 */
155 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
156 		max_tx_streams =
157 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
158 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
159 	else
160 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
161 
162 	/*
163 	 * 802.11n-2009 20.3.5 / 20.6 says:
164 	 * - indices 0 to 7 and 32 are single spatial stream
165 	 * - 8 to 31 are multiple spatial streams using equal modulation
166 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
167 	 * - remainder are multiple spatial streams using unequal modulation
168 	 */
169 	for (i = 0; i < max_tx_streams; i++)
170 		ht_cap->mcs.rx_mask[i] =
171 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
172 
173 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
174 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
175 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
176 			ht_cap->mcs.rx_mask[i] =
177 				sband->ht_cap.mcs.rx_mask[i] &
178 					ht_cap_ie->mcs.rx_mask[i];
179 
180 	/* handle MCS rate 32 too */
181 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
182 		ht_cap->mcs.rx_mask[32/8] |= 1;
183 
184 	/*
185 	 * If user has specified capability over-rides, take care
186 	 * of that here.
187 	 */
188 	ieee80211_apply_htcap_overrides(sdata, ht_cap);
189 }
190 
ieee80211_sta_tear_down_BA_sessions(struct sta_info * sta,bool tx)191 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
192 {
193 	int i;
194 
195 	cancel_work_sync(&sta->ampdu_mlme.work);
196 
197 	for (i = 0; i <  STA_TID_NUM; i++) {
198 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
199 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
200 					       WLAN_REASON_QSTA_LEAVE_QBSS, tx);
201 	}
202 }
203 
ieee80211_ba_session_work(struct work_struct * work)204 void ieee80211_ba_session_work(struct work_struct *work)
205 {
206 	struct sta_info *sta =
207 		container_of(work, struct sta_info, ampdu_mlme.work);
208 	struct tid_ampdu_tx *tid_tx;
209 	int tid;
210 
211 	/*
212 	 * When this flag is set, new sessions should be
213 	 * blocked, and existing sessions will be torn
214 	 * down by the code that set the flag, so this
215 	 * need not run.
216 	 */
217 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
218 		return;
219 
220 	mutex_lock(&sta->ampdu_mlme.mtx);
221 	for (tid = 0; tid < STA_TID_NUM; tid++) {
222 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
223 			___ieee80211_stop_rx_ba_session(
224 				sta, tid, WLAN_BACK_RECIPIENT,
225 				WLAN_REASON_QSTA_TIMEOUT, true);
226 
227 		if (test_and_clear_bit(tid,
228 				       sta->ampdu_mlme.tid_rx_stop_requested))
229 			___ieee80211_stop_rx_ba_session(
230 				sta, tid, WLAN_BACK_RECIPIENT,
231 				WLAN_REASON_UNSPECIFIED, true);
232 
233 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
234 		if (tid_tx) {
235 			/*
236 			 * Assign it over to the normal tid_tx array
237 			 * where it "goes live".
238 			 */
239 			spin_lock_bh(&sta->lock);
240 
241 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
242 			/* could there be a race? */
243 			if (sta->ampdu_mlme.tid_tx[tid])
244 				kfree(tid_tx);
245 			else
246 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
247 			spin_unlock_bh(&sta->lock);
248 
249 			ieee80211_tx_ba_session_handle_start(sta, tid);
250 			continue;
251 		}
252 
253 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
254 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
255 						 &tid_tx->state))
256 			___ieee80211_stop_tx_ba_session(sta, tid,
257 							WLAN_BACK_INITIATOR,
258 							true);
259 	}
260 	mutex_unlock(&sta->ampdu_mlme.mtx);
261 }
262 
ieee80211_send_delba(struct ieee80211_sub_if_data * sdata,const u8 * da,u16 tid,u16 initiator,u16 reason_code)263 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
264 			  const u8 *da, u16 tid,
265 			  u16 initiator, u16 reason_code)
266 {
267 	struct ieee80211_local *local = sdata->local;
268 	struct sk_buff *skb;
269 	struct ieee80211_mgmt *mgmt;
270 	u16 params;
271 
272 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
273 	if (!skb)
274 		return;
275 
276 	skb_reserve(skb, local->hw.extra_tx_headroom);
277 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
278 	memset(mgmt, 0, 24);
279 	memcpy(mgmt->da, da, ETH_ALEN);
280 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
281 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
282 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
283 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
284 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
285 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
286 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
287 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
288 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
289 
290 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
291 					  IEEE80211_STYPE_ACTION);
292 
293 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
294 
295 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
296 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
297 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
298 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
299 
300 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
301 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
302 
303 	ieee80211_tx_skb_tid(sdata, skb, tid);
304 }
305 
ieee80211_process_delba(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)306 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
307 			     struct sta_info *sta,
308 			     struct ieee80211_mgmt *mgmt, size_t len)
309 {
310 	u16 tid, params;
311 	u16 initiator;
312 
313 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
314 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
315 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
316 
317 #ifdef CONFIG_MAC80211_HT_DEBUG
318 	if (net_ratelimit())
319 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
320 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
321 			le16_to_cpu(mgmt->u.action.u.delba.reason_code));
322 #endif /* CONFIG_MAC80211_HT_DEBUG */
323 
324 	if (initiator == WLAN_BACK_INITIATOR)
325 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
326 					       true);
327 	else
328 		__ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
329 					       true);
330 }
331 
ieee80211_send_smps_action(struct ieee80211_sub_if_data * sdata,enum ieee80211_smps_mode smps,const u8 * da,const u8 * bssid)332 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
333 			       enum ieee80211_smps_mode smps, const u8 *da,
334 			       const u8 *bssid)
335 {
336 	struct ieee80211_local *local = sdata->local;
337 	struct sk_buff *skb;
338 	struct ieee80211_mgmt *action_frame;
339 
340 	/* 27 = header + category + action + smps mode */
341 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
342 	if (!skb)
343 		return -ENOMEM;
344 
345 	skb_reserve(skb, local->hw.extra_tx_headroom);
346 	action_frame = (void *)skb_put(skb, 27);
347 	memcpy(action_frame->da, da, ETH_ALEN);
348 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
349 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
350 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
351 						  IEEE80211_STYPE_ACTION);
352 	action_frame->u.action.category = WLAN_CATEGORY_HT;
353 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
354 	switch (smps) {
355 	case IEEE80211_SMPS_AUTOMATIC:
356 	case IEEE80211_SMPS_NUM_MODES:
357 		WARN_ON(1);
358 	case IEEE80211_SMPS_OFF:
359 		action_frame->u.action.u.ht_smps.smps_control =
360 				WLAN_HT_SMPS_CONTROL_DISABLED;
361 		break;
362 	case IEEE80211_SMPS_STATIC:
363 		action_frame->u.action.u.ht_smps.smps_control =
364 				WLAN_HT_SMPS_CONTROL_STATIC;
365 		break;
366 	case IEEE80211_SMPS_DYNAMIC:
367 		action_frame->u.action.u.ht_smps.smps_control =
368 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
369 		break;
370 	}
371 
372 	/* we'll do more on status of this frame */
373 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
374 	ieee80211_tx_skb(sdata, skb);
375 
376 	return 0;
377 }
378 
ieee80211_request_smps_work(struct work_struct * work)379 void ieee80211_request_smps_work(struct work_struct *work)
380 {
381 	struct ieee80211_sub_if_data *sdata =
382 		container_of(work, struct ieee80211_sub_if_data,
383 			     u.mgd.request_smps_work);
384 
385 	mutex_lock(&sdata->u.mgd.mtx);
386 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
387 	mutex_unlock(&sdata->u.mgd.mtx);
388 }
389 
ieee80211_request_smps(struct ieee80211_vif * vif,enum ieee80211_smps_mode smps_mode)390 void ieee80211_request_smps(struct ieee80211_vif *vif,
391 			    enum ieee80211_smps_mode smps_mode)
392 {
393 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
394 
395 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
396 		return;
397 
398 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
399 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
400 
401 	sdata->u.mgd.driver_smps_mode = smps_mode;
402 
403 	ieee80211_queue_work(&sdata->local->hw,
404 			     &sdata->u.mgd.request_smps_work);
405 }
406 /* this might change ... don't want non-open drivers using it */
407 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
408