xref: /linux/net/mac80211/ht.c (revision 2a2c74b2efcb1a0ca3fdcb5fbb96ad8de6a29177)
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_ht_cap *ht_capa,
23 				  struct ieee80211_ht_cap *ht_capa_mask,
24 				  struct ieee80211_sta_ht_cap *ht_cap,
25 				  u16 flag)
26 {
27 	__le16 le_flag = cpu_to_le16(flag);
28 	if (ht_capa_mask->cap_info & le_flag) {
29 		if (!(ht_capa->cap_info & le_flag))
30 			ht_cap->cap &= ~flag;
31 	}
32 }
33 
34 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
35 				     struct ieee80211_sta_ht_cap *ht_cap)
36 {
37 	struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
38 	u8 *scaps, *smask;
39 	int i;
40 
41 	if (!ht_cap->ht_supported)
42 		return;
43 
44 	switch (sdata->vif.type) {
45 	case NL80211_IFTYPE_STATION:
46 		ht_capa = &sdata->u.mgd.ht_capa;
47 		ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
48 		break;
49 	case NL80211_IFTYPE_ADHOC:
50 		ht_capa = &sdata->u.ibss.ht_capa;
51 		ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
52 		break;
53 	default:
54 		WARN_ON_ONCE(1);
55 		return;
56 	}
57 
58 	scaps = (u8 *)(&ht_capa->mcs.rx_mask);
59 	smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
60 
61 	/* NOTE:  If you add more over-rides here, update register_hw
62 	 * ht_capa_mod_msk logic in main.c as well.
63 	 * And, if this method can ever change ht_cap.ht_supported, fix
64 	 * the check in ieee80211_add_ht_ie.
65 	 */
66 
67 	/* check for HT over-rides, MCS rates first. */
68 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
69 		u8 m = smask[i];
70 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
71 		/* Add back rates that are supported */
72 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
73 	}
74 
75 	/* Force removal of HT-40 capabilities? */
76 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
77 			      IEEE80211_HT_CAP_SUP_WIDTH_20_40);
78 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
79 			      IEEE80211_HT_CAP_SGI_40);
80 
81 	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
82 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
83 			      IEEE80211_HT_CAP_SGI_20);
84 
85 	/* Allow user to disable the max-AMSDU bit. */
86 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
87 			      IEEE80211_HT_CAP_MAX_AMSDU);
88 
89 	/* Allow user to decrease AMPDU factor */
90 	if (ht_capa_mask->ampdu_params_info &
91 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
92 		u8 n = ht_capa->ampdu_params_info &
93 		       IEEE80211_HT_AMPDU_PARM_FACTOR;
94 		if (n < ht_cap->ampdu_factor)
95 			ht_cap->ampdu_factor = n;
96 	}
97 
98 	/* Allow the user to increase AMPDU density. */
99 	if (ht_capa_mask->ampdu_params_info &
100 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
101 		u8 n = (ht_capa->ampdu_params_info &
102 			IEEE80211_HT_AMPDU_PARM_DENSITY)
103 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
104 		if (n > ht_cap->ampdu_density)
105 			ht_cap->ampdu_density = n;
106 	}
107 }
108 
109 
110 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
111 				       struct ieee80211_supported_band *sband,
112 				       const struct ieee80211_ht_cap *ht_cap_ie,
113 				       struct sta_info *sta)
114 {
115 	struct ieee80211_sta_ht_cap ht_cap, own_cap;
116 	u8 ampdu_info, tx_mcs_set_cap;
117 	int i, max_tx_streams;
118 	bool changed;
119 	enum ieee80211_sta_rx_bandwidth bw;
120 	enum ieee80211_smps_mode smps_mode;
121 
122 	memset(&ht_cap, 0, sizeof(ht_cap));
123 
124 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
125 		goto apply;
126 
127 	ht_cap.ht_supported = true;
128 
129 	own_cap = sband->ht_cap;
130 
131 	/*
132 	 * If user has specified capability over-rides, take care
133 	 * of that if the station we're setting up is the AP that
134 	 * we advertised a restricted capability set to. Override
135 	 * our own capabilities and then use those below.
136 	 */
137 	if ((sdata->vif.type == NL80211_IFTYPE_STATION ||
138 	     sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
139 	    !test_sta_flag(sta, WLAN_STA_TDLS_PEER))
140 		ieee80211_apply_htcap_overrides(sdata, &own_cap);
141 
142 	/*
143 	 * The bits listed in this expression should be
144 	 * the same for the peer and us, if the station
145 	 * advertises more then we can't use those thus
146 	 * we mask them out.
147 	 */
148 	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
149 		(own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
150 				 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
151 				 IEEE80211_HT_CAP_GRN_FLD |
152 				 IEEE80211_HT_CAP_SGI_20 |
153 				 IEEE80211_HT_CAP_SGI_40 |
154 				 IEEE80211_HT_CAP_DSSSCCK40));
155 
156 	/*
157 	 * The STBC bits are asymmetric -- if we don't have
158 	 * TX then mask out the peer's RX and vice versa.
159 	 */
160 	if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
161 		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
162 	if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
163 		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
164 
165 	ampdu_info = ht_cap_ie->ampdu_params_info;
166 	ht_cap.ampdu_factor =
167 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
168 	ht_cap.ampdu_density =
169 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
170 
171 	/* own MCS TX capabilities */
172 	tx_mcs_set_cap = own_cap.mcs.tx_params;
173 
174 	/* Copy peer MCS TX capabilities, the driver might need them. */
175 	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
176 
177 	/* can we TX with MCS rates? */
178 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
179 		goto apply;
180 
181 	/* Counting from 0, therefore +1 */
182 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
183 		max_tx_streams =
184 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
185 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
186 	else
187 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
188 
189 	/*
190 	 * 802.11n-2009 20.3.5 / 20.6 says:
191 	 * - indices 0 to 7 and 32 are single spatial stream
192 	 * - 8 to 31 are multiple spatial streams using equal modulation
193 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
194 	 * - remainder are multiple spatial streams using unequal modulation
195 	 */
196 	for (i = 0; i < max_tx_streams; i++)
197 		ht_cap.mcs.rx_mask[i] =
198 			own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
199 
200 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
201 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
202 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
203 			ht_cap.mcs.rx_mask[i] =
204 				own_cap.mcs.rx_mask[i] &
205 					ht_cap_ie->mcs.rx_mask[i];
206 
207 	/* handle MCS rate 32 too */
208 	if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
209 		ht_cap.mcs.rx_mask[32/8] |= 1;
210 
211  apply:
212 	changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
213 
214 	memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
215 
216 	switch (sdata->vif.bss_conf.chandef.width) {
217 	default:
218 		WARN_ON_ONCE(1);
219 		/* fall through */
220 	case NL80211_CHAN_WIDTH_20_NOHT:
221 	case NL80211_CHAN_WIDTH_20:
222 		bw = IEEE80211_STA_RX_BW_20;
223 		break;
224 	case NL80211_CHAN_WIDTH_40:
225 	case NL80211_CHAN_WIDTH_80:
226 	case NL80211_CHAN_WIDTH_80P80:
227 	case NL80211_CHAN_WIDTH_160:
228 		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
229 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
230 		break;
231 	}
232 
233 	if (bw != sta->sta.bandwidth)
234 		changed = true;
235 	sta->sta.bandwidth = bw;
236 
237 	sta->cur_max_bandwidth =
238 		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
239 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
240 
241 	switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
242 			>> IEEE80211_HT_CAP_SM_PS_SHIFT) {
243 	case WLAN_HT_CAP_SM_PS_INVALID:
244 	case WLAN_HT_CAP_SM_PS_STATIC:
245 		smps_mode = IEEE80211_SMPS_STATIC;
246 		break;
247 	case WLAN_HT_CAP_SM_PS_DYNAMIC:
248 		smps_mode = IEEE80211_SMPS_DYNAMIC;
249 		break;
250 	case WLAN_HT_CAP_SM_PS_DISABLED:
251 		smps_mode = IEEE80211_SMPS_OFF;
252 		break;
253 	}
254 
255 	if (smps_mode != sta->sta.smps_mode)
256 		changed = true;
257 	sta->sta.smps_mode = smps_mode;
258 
259 	return changed;
260 }
261 
262 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
263 					 enum ieee80211_agg_stop_reason reason)
264 {
265 	int i;
266 
267 	cancel_work_sync(&sta->ampdu_mlme.work);
268 
269 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
270 		__ieee80211_stop_tx_ba_session(sta, i, reason);
271 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
272 					       WLAN_REASON_QSTA_LEAVE_QBSS,
273 					       reason != AGG_STOP_DESTROY_STA &&
274 					       reason != AGG_STOP_PEER_REQUEST);
275 	}
276 }
277 
278 void ieee80211_ba_session_work(struct work_struct *work)
279 {
280 	struct sta_info *sta =
281 		container_of(work, struct sta_info, ampdu_mlme.work);
282 	struct tid_ampdu_tx *tid_tx;
283 	int tid;
284 
285 	/*
286 	 * When this flag is set, new sessions should be
287 	 * blocked, and existing sessions will be torn
288 	 * down by the code that set the flag, so this
289 	 * need not run.
290 	 */
291 	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
292 		return;
293 
294 	mutex_lock(&sta->ampdu_mlme.mtx);
295 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
296 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
297 			___ieee80211_stop_rx_ba_session(
298 				sta, tid, WLAN_BACK_RECIPIENT,
299 				WLAN_REASON_QSTA_TIMEOUT, true);
300 
301 		if (test_and_clear_bit(tid,
302 				       sta->ampdu_mlme.tid_rx_stop_requested))
303 			___ieee80211_stop_rx_ba_session(
304 				sta, tid, WLAN_BACK_RECIPIENT,
305 				WLAN_REASON_UNSPECIFIED, true);
306 
307 		spin_lock_bh(&sta->lock);
308 
309 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
310 		if (tid_tx) {
311 			/*
312 			 * Assign it over to the normal tid_tx array
313 			 * where it "goes live".
314 			 */
315 
316 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
317 			/* could there be a race? */
318 			if (sta->ampdu_mlme.tid_tx[tid])
319 				kfree(tid_tx);
320 			else
321 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
322 			spin_unlock_bh(&sta->lock);
323 
324 			ieee80211_tx_ba_session_handle_start(sta, tid);
325 			continue;
326 		}
327 		spin_unlock_bh(&sta->lock);
328 
329 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
330 		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
331 						 &tid_tx->state))
332 			___ieee80211_stop_tx_ba_session(sta, tid,
333 							AGG_STOP_LOCAL_REQUEST);
334 	}
335 	mutex_unlock(&sta->ampdu_mlme.mtx);
336 }
337 
338 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
339 			  const u8 *da, u16 tid,
340 			  u16 initiator, u16 reason_code)
341 {
342 	struct ieee80211_local *local = sdata->local;
343 	struct sk_buff *skb;
344 	struct ieee80211_mgmt *mgmt;
345 	u16 params;
346 
347 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
348 	if (!skb)
349 		return;
350 
351 	skb_reserve(skb, local->hw.extra_tx_headroom);
352 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
353 	memset(mgmt, 0, 24);
354 	memcpy(mgmt->da, da, ETH_ALEN);
355 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
356 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
357 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
358 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
359 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
360 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
361 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
362 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
363 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
364 
365 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
366 					  IEEE80211_STYPE_ACTION);
367 
368 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
369 
370 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
371 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
372 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
373 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
374 
375 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
376 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
377 
378 	ieee80211_tx_skb(sdata, skb);
379 }
380 
381 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
382 			     struct sta_info *sta,
383 			     struct ieee80211_mgmt *mgmt, size_t len)
384 {
385 	u16 tid, params;
386 	u16 initiator;
387 
388 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
389 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
390 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
391 
392 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
393 			   mgmt->sa, initiator ? "initiator" : "recipient",
394 			   tid,
395 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
396 
397 	if (initiator == WLAN_BACK_INITIATOR)
398 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
399 					       true);
400 	else
401 		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
402 }
403 
404 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
405 			       enum ieee80211_smps_mode smps, const u8 *da,
406 			       const u8 *bssid)
407 {
408 	struct ieee80211_local *local = sdata->local;
409 	struct sk_buff *skb;
410 	struct ieee80211_mgmt *action_frame;
411 
412 	/* 27 = header + category + action + smps mode */
413 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
414 	if (!skb)
415 		return -ENOMEM;
416 
417 	skb_reserve(skb, local->hw.extra_tx_headroom);
418 	action_frame = (void *)skb_put(skb, 27);
419 	memcpy(action_frame->da, da, ETH_ALEN);
420 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
421 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
422 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
423 						  IEEE80211_STYPE_ACTION);
424 	action_frame->u.action.category = WLAN_CATEGORY_HT;
425 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
426 	switch (smps) {
427 	case IEEE80211_SMPS_AUTOMATIC:
428 	case IEEE80211_SMPS_NUM_MODES:
429 		WARN_ON(1);
430 	case IEEE80211_SMPS_OFF:
431 		action_frame->u.action.u.ht_smps.smps_control =
432 				WLAN_HT_SMPS_CONTROL_DISABLED;
433 		break;
434 	case IEEE80211_SMPS_STATIC:
435 		action_frame->u.action.u.ht_smps.smps_control =
436 				WLAN_HT_SMPS_CONTROL_STATIC;
437 		break;
438 	case IEEE80211_SMPS_DYNAMIC:
439 		action_frame->u.action.u.ht_smps.smps_control =
440 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
441 		break;
442 	}
443 
444 	/* we'll do more on status of this frame */
445 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
446 	ieee80211_tx_skb(sdata, skb);
447 
448 	return 0;
449 }
450 
451 void ieee80211_request_smps_mgd_work(struct work_struct *work)
452 {
453 	struct ieee80211_sub_if_data *sdata =
454 		container_of(work, struct ieee80211_sub_if_data,
455 			     u.mgd.request_smps_work);
456 
457 	sdata_lock(sdata);
458 	__ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
459 	sdata_unlock(sdata);
460 }
461 
462 void ieee80211_request_smps_ap_work(struct work_struct *work)
463 {
464 	struct ieee80211_sub_if_data *sdata =
465 		container_of(work, struct ieee80211_sub_if_data,
466 			     u.ap.request_smps_work);
467 
468 	sdata_lock(sdata);
469 	if (sdata_dereference(sdata->u.ap.beacon, sdata))
470 		__ieee80211_request_smps_ap(sdata,
471 					    sdata->u.ap.driver_smps_mode);
472 	sdata_unlock(sdata);
473 }
474 
475 void ieee80211_request_smps(struct ieee80211_vif *vif,
476 			    enum ieee80211_smps_mode smps_mode)
477 {
478 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
479 
480 	if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
481 			 vif->type != NL80211_IFTYPE_AP))
482 		return;
483 
484 	if (vif->type == NL80211_IFTYPE_STATION) {
485 		if (sdata->u.mgd.driver_smps_mode == smps_mode)
486 			return;
487 		sdata->u.mgd.driver_smps_mode = smps_mode;
488 		ieee80211_queue_work(&sdata->local->hw,
489 				     &sdata->u.mgd.request_smps_work);
490 	} else {
491 		/* AUTOMATIC is meaningless in AP mode */
492 		if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
493 			return;
494 		if (sdata->u.ap.driver_smps_mode == smps_mode)
495 			return;
496 		sdata->u.ap.driver_smps_mode = smps_mode;
497 		ieee80211_queue_work(&sdata->local->hw,
498 				     &sdata->u.ap.request_smps_work);
499 	}
500 }
501 /* this might change ... don't want non-open drivers using it */
502 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
503