xref: /openbmc/linux/net/mac80211/ht.c (revision 5104d265)
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 (!ht_cap->ht_supported)
41 		return;
42 
43 	/* NOTE:  If you add more over-rides here, update register_hw
44 	 * ht_capa_mod_msk logic in main.c as well.
45 	 * And, if this method can ever change ht_cap.ht_supported, fix
46 	 * the check in ieee80211_add_ht_ie.
47 	 */
48 
49 	/* check for HT over-rides, MCS rates first. */
50 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
51 		u8 m = smask[i];
52 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
53 		/* Add back rates that are supported */
54 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
55 	}
56 
57 	/* Force removal of HT-40 capabilities? */
58 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
59 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
60 
61 	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
62 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_20);
63 
64 	/* Allow user to disable the max-AMSDU bit. */
65 	__check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
66 
67 	/* Allow user to decrease AMPDU factor */
68 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
69 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
70 		u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
71 			& IEEE80211_HT_AMPDU_PARM_FACTOR;
72 		if (n < ht_cap->ampdu_factor)
73 			ht_cap->ampdu_factor = n;
74 	}
75 
76 	/* Allow the user to increase AMPDU density. */
77 	if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
78 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
79 		u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
80 			IEEE80211_HT_AMPDU_PARM_DENSITY)
81 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
82 		if (n > ht_cap->ampdu_density)
83 			ht_cap->ampdu_density = n;
84 	}
85 }
86 
87 
88 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
89 				       struct ieee80211_supported_band *sband,
90 				       const struct ieee80211_ht_cap *ht_cap_ie,
91 				       struct sta_info *sta)
92 {
93 	struct ieee80211_sta_ht_cap ht_cap, own_cap;
94 	u8 ampdu_info, tx_mcs_set_cap;
95 	int i, max_tx_streams;
96 	bool changed;
97 	enum ieee80211_sta_rx_bandwidth bw;
98 	enum ieee80211_smps_mode smps_mode;
99 
100 	memset(&ht_cap, 0, sizeof(ht_cap));
101 
102 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
103 		goto apply;
104 
105 	ht_cap.ht_supported = true;
106 
107 	own_cap = sband->ht_cap;
108 
109 	/*
110 	 * If user has specified capability over-rides, take care
111 	 * of that if the station we're setting up is the AP that
112 	 * we advertised a restricted capability set to. Override
113 	 * our own capabilities and then use those below.
114 	 */
115 	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
116 	    !test_sta_flag(sta, WLAN_STA_TDLS_PEER))
117 		ieee80211_apply_htcap_overrides(sdata, &own_cap);
118 
119 	/*
120 	 * The bits listed in this expression should be
121 	 * the same for the peer and us, if the station
122 	 * advertises more then we can't use those thus
123 	 * we mask them out.
124 	 */
125 	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
126 		(own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
127 				 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
128 				 IEEE80211_HT_CAP_GRN_FLD |
129 				 IEEE80211_HT_CAP_SGI_20 |
130 				 IEEE80211_HT_CAP_SGI_40 |
131 				 IEEE80211_HT_CAP_DSSSCCK40));
132 
133 	/*
134 	 * The STBC bits are asymmetric -- if we don't have
135 	 * TX then mask out the peer's RX and vice versa.
136 	 */
137 	if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
138 		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
139 	if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
140 		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
141 
142 	ampdu_info = ht_cap_ie->ampdu_params_info;
143 	ht_cap.ampdu_factor =
144 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
145 	ht_cap.ampdu_density =
146 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
147 
148 	/* own MCS TX capabilities */
149 	tx_mcs_set_cap = own_cap.mcs.tx_params;
150 
151 	/* Copy peer MCS TX capabilities, the driver might need them. */
152 	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
153 
154 	/* can we TX with MCS rates? */
155 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
156 		goto apply;
157 
158 	/* Counting from 0, therefore +1 */
159 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
160 		max_tx_streams =
161 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
162 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
163 	else
164 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
165 
166 	/*
167 	 * 802.11n-2009 20.3.5 / 20.6 says:
168 	 * - indices 0 to 7 and 32 are single spatial stream
169 	 * - 8 to 31 are multiple spatial streams using equal modulation
170 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
171 	 * - remainder are multiple spatial streams using unequal modulation
172 	 */
173 	for (i = 0; i < max_tx_streams; i++)
174 		ht_cap.mcs.rx_mask[i] =
175 			own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
176 
177 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
178 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
179 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
180 			ht_cap.mcs.rx_mask[i] =
181 				own_cap.mcs.rx_mask[i] &
182 					ht_cap_ie->mcs.rx_mask[i];
183 
184 	/* handle MCS rate 32 too */
185 	if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
186 		ht_cap.mcs.rx_mask[32/8] |= 1;
187 
188  apply:
189 	changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
190 
191 	memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
192 
193 	switch (sdata->vif.bss_conf.chandef.width) {
194 	default:
195 		WARN_ON_ONCE(1);
196 		/* fall through */
197 	case NL80211_CHAN_WIDTH_20_NOHT:
198 	case NL80211_CHAN_WIDTH_20:
199 		bw = IEEE80211_STA_RX_BW_20;
200 		break;
201 	case NL80211_CHAN_WIDTH_40:
202 	case NL80211_CHAN_WIDTH_80:
203 	case NL80211_CHAN_WIDTH_80P80:
204 	case NL80211_CHAN_WIDTH_160:
205 		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
206 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
207 		break;
208 	}
209 
210 	if (bw != sta->sta.bandwidth)
211 		changed = true;
212 	sta->sta.bandwidth = bw;
213 
214 	sta->cur_max_bandwidth =
215 		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
216 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
217 
218 	switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
219 			>> IEEE80211_HT_CAP_SM_PS_SHIFT) {
220 	case WLAN_HT_CAP_SM_PS_INVALID:
221 	case WLAN_HT_CAP_SM_PS_STATIC:
222 		smps_mode = IEEE80211_SMPS_STATIC;
223 		break;
224 	case WLAN_HT_CAP_SM_PS_DYNAMIC:
225 		smps_mode = IEEE80211_SMPS_DYNAMIC;
226 		break;
227 	case WLAN_HT_CAP_SM_PS_DISABLED:
228 		smps_mode = IEEE80211_SMPS_OFF;
229 		break;
230 	}
231 
232 	if (smps_mode != sta->sta.smps_mode)
233 		changed = true;
234 	sta->sta.smps_mode = smps_mode;
235 
236 	return changed;
237 }
238 
239 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
240 					 enum ieee80211_agg_stop_reason reason)
241 {
242 	int i;
243 
244 	cancel_work_sync(&sta->ampdu_mlme.work);
245 
246 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
247 		__ieee80211_stop_tx_ba_session(sta, i, reason);
248 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
249 					       WLAN_REASON_QSTA_LEAVE_QBSS,
250 					       reason != AGG_STOP_DESTROY_STA &&
251 					       reason != AGG_STOP_PEER_REQUEST);
252 	}
253 }
254 
255 void ieee80211_ba_session_work(struct work_struct *work)
256 {
257 	struct sta_info *sta =
258 		container_of(work, struct sta_info, ampdu_mlme.work);
259 	struct tid_ampdu_tx *tid_tx;
260 	int tid;
261 
262 	/*
263 	 * When this flag is set, new sessions should be
264 	 * blocked, and existing sessions will be torn
265 	 * down by the code that set the flag, so this
266 	 * need not run.
267 	 */
268 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
269 		return;
270 
271 	mutex_lock(&sta->ampdu_mlme.mtx);
272 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
273 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
274 			___ieee80211_stop_rx_ba_session(
275 				sta, tid, WLAN_BACK_RECIPIENT,
276 				WLAN_REASON_QSTA_TIMEOUT, true);
277 
278 		if (test_and_clear_bit(tid,
279 				       sta->ampdu_mlme.tid_rx_stop_requested))
280 			___ieee80211_stop_rx_ba_session(
281 				sta, tid, WLAN_BACK_RECIPIENT,
282 				WLAN_REASON_UNSPECIFIED, true);
283 
284 		spin_lock_bh(&sta->lock);
285 
286 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
287 		if (tid_tx) {
288 			/*
289 			 * Assign it over to the normal tid_tx array
290 			 * where it "goes live".
291 			 */
292 
293 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
294 			/* could there be a race? */
295 			if (sta->ampdu_mlme.tid_tx[tid])
296 				kfree(tid_tx);
297 			else
298 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
299 			spin_unlock_bh(&sta->lock);
300 
301 			ieee80211_tx_ba_session_handle_start(sta, tid);
302 			continue;
303 		}
304 		spin_unlock_bh(&sta->lock);
305 
306 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
307 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
308 						 &tid_tx->state))
309 			___ieee80211_stop_tx_ba_session(sta, tid,
310 							AGG_STOP_LOCAL_REQUEST);
311 	}
312 	mutex_unlock(&sta->ampdu_mlme.mtx);
313 }
314 
315 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
316 			  const u8 *da, u16 tid,
317 			  u16 initiator, u16 reason_code)
318 {
319 	struct ieee80211_local *local = sdata->local;
320 	struct sk_buff *skb;
321 	struct ieee80211_mgmt *mgmt;
322 	u16 params;
323 
324 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
325 	if (!skb)
326 		return;
327 
328 	skb_reserve(skb, local->hw.extra_tx_headroom);
329 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
330 	memset(mgmt, 0, 24);
331 	memcpy(mgmt->da, da, ETH_ALEN);
332 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
333 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
334 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
335 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
336 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
337 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
338 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
339 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
340 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
341 
342 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
343 					  IEEE80211_STYPE_ACTION);
344 
345 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
346 
347 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
348 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
349 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
350 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
351 
352 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
353 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
354 
355 	ieee80211_tx_skb_tid(sdata, skb, tid);
356 }
357 
358 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
359 			     struct sta_info *sta,
360 			     struct ieee80211_mgmt *mgmt, size_t len)
361 {
362 	u16 tid, params;
363 	u16 initiator;
364 
365 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
366 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
367 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
368 
369 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
370 			   mgmt->sa, initiator ? "initiator" : "recipient",
371 			   tid,
372 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
373 
374 	if (initiator == WLAN_BACK_INITIATOR)
375 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
376 					       true);
377 	else
378 		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
379 }
380 
381 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
382 			       enum ieee80211_smps_mode smps, const u8 *da,
383 			       const u8 *bssid)
384 {
385 	struct ieee80211_local *local = sdata->local;
386 	struct sk_buff *skb;
387 	struct ieee80211_mgmt *action_frame;
388 
389 	/* 27 = header + category + action + smps mode */
390 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
391 	if (!skb)
392 		return -ENOMEM;
393 
394 	skb_reserve(skb, local->hw.extra_tx_headroom);
395 	action_frame = (void *)skb_put(skb, 27);
396 	memcpy(action_frame->da, da, ETH_ALEN);
397 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
398 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
399 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
400 						  IEEE80211_STYPE_ACTION);
401 	action_frame->u.action.category = WLAN_CATEGORY_HT;
402 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
403 	switch (smps) {
404 	case IEEE80211_SMPS_AUTOMATIC:
405 	case IEEE80211_SMPS_NUM_MODES:
406 		WARN_ON(1);
407 	case IEEE80211_SMPS_OFF:
408 		action_frame->u.action.u.ht_smps.smps_control =
409 				WLAN_HT_SMPS_CONTROL_DISABLED;
410 		break;
411 	case IEEE80211_SMPS_STATIC:
412 		action_frame->u.action.u.ht_smps.smps_control =
413 				WLAN_HT_SMPS_CONTROL_STATIC;
414 		break;
415 	case IEEE80211_SMPS_DYNAMIC:
416 		action_frame->u.action.u.ht_smps.smps_control =
417 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
418 		break;
419 	}
420 
421 	/* we'll do more on status of this frame */
422 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
423 	ieee80211_tx_skb(sdata, skb);
424 
425 	return 0;
426 }
427 
428 void ieee80211_request_smps_work(struct work_struct *work)
429 {
430 	struct ieee80211_sub_if_data *sdata =
431 		container_of(work, struct ieee80211_sub_if_data,
432 			     u.mgd.request_smps_work);
433 
434 	sdata_lock(sdata);
435 	__ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
436 	sdata_unlock(sdata);
437 }
438 
439 void ieee80211_request_smps(struct ieee80211_vif *vif,
440 			    enum ieee80211_smps_mode smps_mode)
441 {
442 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
443 
444 	if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
445 		return;
446 
447 	if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
448 		smps_mode = IEEE80211_SMPS_AUTOMATIC;
449 
450 	if (sdata->u.mgd.driver_smps_mode == smps_mode)
451 		return;
452 
453 	sdata->u.mgd.driver_smps_mode = smps_mode;
454 
455 	ieee80211_queue_work(&sdata->local->hw,
456 			     &sdata->u.mgd.request_smps_work);
457 }
458 /* this might change ... don't want non-open drivers using it */
459 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
460