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
22static 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
34static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
35				  struct ieee80211_ht_cap *ht_capa_mask,
36				  struct ieee80211_sta_ht_cap *ht_cap,
37				  u16 flag)
38{
39	__le16 le_flag = cpu_to_le16(flag);
40
41	if ((ht_capa_mask->cap_info & le_flag) &&
42	    (ht_capa->cap_info & le_flag))
43		ht_cap->cap |= flag;
44}
45
46void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
47				     struct ieee80211_sta_ht_cap *ht_cap)
48{
49	struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
50	u8 *scaps, *smask;
51	int i;
52
53	if (!ht_cap->ht_supported)
54		return;
55
56	switch (sdata->vif.type) {
57	case NL80211_IFTYPE_STATION:
58		ht_capa = &sdata->u.mgd.ht_capa;
59		ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
60		break;
61	case NL80211_IFTYPE_ADHOC:
62		ht_capa = &sdata->u.ibss.ht_capa;
63		ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
64		break;
65	default:
66		WARN_ON_ONCE(1);
67		return;
68	}
69
70	scaps = (u8 *)(&ht_capa->mcs.rx_mask);
71	smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
72
73	/* NOTE:  If you add more over-rides here, update register_hw
74	 * ht_capa_mod_mask logic in main.c as well.
75	 * And, if this method can ever change ht_cap.ht_supported, fix
76	 * the check in ieee80211_add_ht_ie.
77	 */
78
79	/* check for HT over-rides, MCS rates first. */
80	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
81		u8 m = smask[i];
82		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
83		/* Add back rates that are supported */
84		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
85	}
86
87	/* Force removal of HT-40 capabilities? */
88	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
89			      IEEE80211_HT_CAP_SUP_WIDTH_20_40);
90	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
91			      IEEE80211_HT_CAP_SGI_40);
92
93	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
94	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
95			      IEEE80211_HT_CAP_SGI_20);
96
97	/* Allow user to disable the max-AMSDU bit. */
98	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
99			      IEEE80211_HT_CAP_MAX_AMSDU);
100
101	/* Allow user to disable LDPC */
102	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
103			      IEEE80211_HT_CAP_LDPC_CODING);
104
105	/* Allow user to enable 40 MHz intolerant bit. */
106	__check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
107			     IEEE80211_HT_CAP_40MHZ_INTOLERANT);
108
109	/* Allow user to decrease AMPDU factor */
110	if (ht_capa_mask->ampdu_params_info &
111	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
112		u8 n = ht_capa->ampdu_params_info &
113		       IEEE80211_HT_AMPDU_PARM_FACTOR;
114		if (n < ht_cap->ampdu_factor)
115			ht_cap->ampdu_factor = n;
116	}
117
118	/* Allow the user to increase AMPDU density. */
119	if (ht_capa_mask->ampdu_params_info &
120	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
121		u8 n = (ht_capa->ampdu_params_info &
122			IEEE80211_HT_AMPDU_PARM_DENSITY)
123			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
124		if (n > ht_cap->ampdu_density)
125			ht_cap->ampdu_density = n;
126	}
127}
128
129
130bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
131				       struct ieee80211_supported_band *sband,
132				       const struct ieee80211_ht_cap *ht_cap_ie,
133				       struct sta_info *sta)
134{
135	struct ieee80211_sta_ht_cap ht_cap, own_cap;
136	u8 ampdu_info, tx_mcs_set_cap;
137	int i, max_tx_streams;
138	bool changed;
139	enum ieee80211_sta_rx_bandwidth bw;
140	enum ieee80211_smps_mode smps_mode;
141
142	memset(&ht_cap, 0, sizeof(ht_cap));
143
144	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
145		goto apply;
146
147	ht_cap.ht_supported = true;
148
149	own_cap = sband->ht_cap;
150
151	/*
152	 * If user has specified capability over-rides, take care
153	 * of that if the station we're setting up is the AP or TDLS peer that
154	 * we advertised a restricted capability set to. Override
155	 * our own capabilities and then use those below.
156	 */
157	if (sdata->vif.type == NL80211_IFTYPE_STATION ||
158	    sdata->vif.type == NL80211_IFTYPE_ADHOC)
159		ieee80211_apply_htcap_overrides(sdata, &own_cap);
160
161	/*
162	 * The bits listed in this expression should be
163	 * the same for the peer and us, if the station
164	 * advertises more then we can't use those thus
165	 * we mask them out.
166	 */
167	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
168		(own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
169				 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
170				 IEEE80211_HT_CAP_GRN_FLD |
171				 IEEE80211_HT_CAP_SGI_20 |
172				 IEEE80211_HT_CAP_SGI_40 |
173				 IEEE80211_HT_CAP_DSSSCCK40));
174
175	/*
176	 * The STBC bits are asymmetric -- if we don't have
177	 * TX then mask out the peer's RX and vice versa.
178	 */
179	if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
180		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
181	if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
182		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
183
184	ampdu_info = ht_cap_ie->ampdu_params_info;
185	ht_cap.ampdu_factor =
186		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
187	ht_cap.ampdu_density =
188		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
189
190	/* own MCS TX capabilities */
191	tx_mcs_set_cap = own_cap.mcs.tx_params;
192
193	/* Copy peer MCS TX capabilities, the driver might need them. */
194	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
195
196	/* can we TX with MCS rates? */
197	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
198		goto apply;
199
200	/* Counting from 0, therefore +1 */
201	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
202		max_tx_streams =
203			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
204				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
205	else
206		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
207
208	/*
209	 * 802.11n-2009 20.3.5 / 20.6 says:
210	 * - indices 0 to 7 and 32 are single spatial stream
211	 * - 8 to 31 are multiple spatial streams using equal modulation
212	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
213	 * - remainder are multiple spatial streams using unequal modulation
214	 */
215	for (i = 0; i < max_tx_streams; i++)
216		ht_cap.mcs.rx_mask[i] =
217			own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
218
219	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
220		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
221		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
222			ht_cap.mcs.rx_mask[i] =
223				own_cap.mcs.rx_mask[i] &
224					ht_cap_ie->mcs.rx_mask[i];
225
226	/* handle MCS rate 32 too */
227	if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
228		ht_cap.mcs.rx_mask[32/8] |= 1;
229
230	/* set Rx highest rate */
231	ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
232
233 apply:
234	changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
235
236	memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
237
238	switch (sdata->vif.bss_conf.chandef.width) {
239	default:
240		WARN_ON_ONCE(1);
241		/* fall through */
242	case NL80211_CHAN_WIDTH_20_NOHT:
243	case NL80211_CHAN_WIDTH_20:
244		bw = IEEE80211_STA_RX_BW_20;
245		break;
246	case NL80211_CHAN_WIDTH_40:
247	case NL80211_CHAN_WIDTH_80:
248	case NL80211_CHAN_WIDTH_80P80:
249	case NL80211_CHAN_WIDTH_160:
250		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
251				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
252		break;
253	}
254
255	sta->sta.bandwidth = bw;
256
257	sta->cur_max_bandwidth =
258		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
259				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
260
261	switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
262			>> IEEE80211_HT_CAP_SM_PS_SHIFT) {
263	case WLAN_HT_CAP_SM_PS_INVALID:
264	case WLAN_HT_CAP_SM_PS_STATIC:
265		smps_mode = IEEE80211_SMPS_STATIC;
266		break;
267	case WLAN_HT_CAP_SM_PS_DYNAMIC:
268		smps_mode = IEEE80211_SMPS_DYNAMIC;
269		break;
270	case WLAN_HT_CAP_SM_PS_DISABLED:
271		smps_mode = IEEE80211_SMPS_OFF;
272		break;
273	}
274
275	if (smps_mode != sta->sta.smps_mode)
276		changed = true;
277	sta->sta.smps_mode = smps_mode;
278
279	return changed;
280}
281
282void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
283					 enum ieee80211_agg_stop_reason reason)
284{
285	int i;
286
287	cancel_work_sync(&sta->ampdu_mlme.work);
288
289	for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
290		__ieee80211_stop_tx_ba_session(sta, i, reason);
291		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
292					       WLAN_REASON_QSTA_LEAVE_QBSS,
293					       reason != AGG_STOP_DESTROY_STA &&
294					       reason != AGG_STOP_PEER_REQUEST);
295	}
296}
297
298void ieee80211_ba_session_work(struct work_struct *work)
299{
300	struct sta_info *sta =
301		container_of(work, struct sta_info, ampdu_mlme.work);
302	struct tid_ampdu_tx *tid_tx;
303	int tid;
304
305	/*
306	 * When this flag is set, new sessions should be
307	 * blocked, and existing sessions will be torn
308	 * down by the code that set the flag, so this
309	 * need not run.
310	 */
311	if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
312		return;
313
314	mutex_lock(&sta->ampdu_mlme.mtx);
315	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
316		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
317			___ieee80211_stop_rx_ba_session(
318				sta, tid, WLAN_BACK_RECIPIENT,
319				WLAN_REASON_QSTA_TIMEOUT, true);
320
321		if (test_and_clear_bit(tid,
322				       sta->ampdu_mlme.tid_rx_stop_requested))
323			___ieee80211_stop_rx_ba_session(
324				sta, tid, WLAN_BACK_RECIPIENT,
325				WLAN_REASON_UNSPECIFIED, true);
326
327		spin_lock_bh(&sta->lock);
328
329		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
330		if (tid_tx) {
331			/*
332			 * Assign it over to the normal tid_tx array
333			 * where it "goes live".
334			 */
335
336			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
337			/* could there be a race? */
338			if (sta->ampdu_mlme.tid_tx[tid])
339				kfree(tid_tx);
340			else
341				ieee80211_assign_tid_tx(sta, tid, tid_tx);
342			spin_unlock_bh(&sta->lock);
343
344			ieee80211_tx_ba_session_handle_start(sta, tid);
345			continue;
346		}
347		spin_unlock_bh(&sta->lock);
348
349		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
350		if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
351						 &tid_tx->state))
352			___ieee80211_stop_tx_ba_session(sta, tid,
353							AGG_STOP_LOCAL_REQUEST);
354	}
355	mutex_unlock(&sta->ampdu_mlme.mtx);
356}
357
358void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
359			  const u8 *da, u16 tid,
360			  u16 initiator, u16 reason_code)
361{
362	struct ieee80211_local *local = sdata->local;
363	struct sk_buff *skb;
364	struct ieee80211_mgmt *mgmt;
365	u16 params;
366
367	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
368	if (!skb)
369		return;
370
371	skb_reserve(skb, local->hw.extra_tx_headroom);
372	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
373	memset(mgmt, 0, 24);
374	memcpy(mgmt->da, da, ETH_ALEN);
375	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
376	if (sdata->vif.type == NL80211_IFTYPE_AP ||
377	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
378	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
379		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
380	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
381		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
382	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
383		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
384
385	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
386					  IEEE80211_STYPE_ACTION);
387
388	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
389
390	mgmt->u.action.category = WLAN_CATEGORY_BACK;
391	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
392	params = (u16)(initiator << 11); 	/* bit 11 initiator */
393	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
394
395	mgmt->u.action.u.delba.params = cpu_to_le16(params);
396	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
397
398	ieee80211_tx_skb(sdata, skb);
399}
400
401void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
402			     struct sta_info *sta,
403			     struct ieee80211_mgmt *mgmt, size_t len)
404{
405	u16 tid, params;
406	u16 initiator;
407
408	params = le16_to_cpu(mgmt->u.action.u.delba.params);
409	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
410	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
411
412	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
413			   mgmt->sa, initiator ? "initiator" : "recipient",
414			   tid,
415			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
416
417	if (initiator == WLAN_BACK_INITIATOR)
418		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
419					       true);
420	else
421		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
422}
423
424int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
425			       enum ieee80211_smps_mode smps, const u8 *da,
426			       const u8 *bssid)
427{
428	struct ieee80211_local *local = sdata->local;
429	struct sk_buff *skb;
430	struct ieee80211_mgmt *action_frame;
431
432	/* 27 = header + category + action + smps mode */
433	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
434	if (!skb)
435		return -ENOMEM;
436
437	skb_reserve(skb, local->hw.extra_tx_headroom);
438	action_frame = (void *)skb_put(skb, 27);
439	memcpy(action_frame->da, da, ETH_ALEN);
440	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
441	memcpy(action_frame->bssid, bssid, ETH_ALEN);
442	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
443						  IEEE80211_STYPE_ACTION);
444	action_frame->u.action.category = WLAN_CATEGORY_HT;
445	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
446	switch (smps) {
447	case IEEE80211_SMPS_AUTOMATIC:
448	case IEEE80211_SMPS_NUM_MODES:
449		WARN_ON(1);
450	case IEEE80211_SMPS_OFF:
451		action_frame->u.action.u.ht_smps.smps_control =
452				WLAN_HT_SMPS_CONTROL_DISABLED;
453		break;
454	case IEEE80211_SMPS_STATIC:
455		action_frame->u.action.u.ht_smps.smps_control =
456				WLAN_HT_SMPS_CONTROL_STATIC;
457		break;
458	case IEEE80211_SMPS_DYNAMIC:
459		action_frame->u.action.u.ht_smps.smps_control =
460				WLAN_HT_SMPS_CONTROL_DYNAMIC;
461		break;
462	}
463
464	/* we'll do more on status of this frame */
465	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
466	ieee80211_tx_skb(sdata, skb);
467
468	return 0;
469}
470
471void ieee80211_request_smps_mgd_work(struct work_struct *work)
472{
473	struct ieee80211_sub_if_data *sdata =
474		container_of(work, struct ieee80211_sub_if_data,
475			     u.mgd.request_smps_work);
476
477	sdata_lock(sdata);
478	__ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
479	sdata_unlock(sdata);
480}
481
482void ieee80211_request_smps_ap_work(struct work_struct *work)
483{
484	struct ieee80211_sub_if_data *sdata =
485		container_of(work, struct ieee80211_sub_if_data,
486			     u.ap.request_smps_work);
487
488	sdata_lock(sdata);
489	if (sdata_dereference(sdata->u.ap.beacon, sdata))
490		__ieee80211_request_smps_ap(sdata,
491					    sdata->u.ap.driver_smps_mode);
492	sdata_unlock(sdata);
493}
494
495void ieee80211_request_smps(struct ieee80211_vif *vif,
496			    enum ieee80211_smps_mode smps_mode)
497{
498	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
499
500	if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
501			 vif->type != NL80211_IFTYPE_AP))
502		return;
503
504	if (vif->type == NL80211_IFTYPE_STATION) {
505		if (sdata->u.mgd.driver_smps_mode == smps_mode)
506			return;
507		sdata->u.mgd.driver_smps_mode = smps_mode;
508		ieee80211_queue_work(&sdata->local->hw,
509				     &sdata->u.mgd.request_smps_work);
510	} else {
511		/* AUTOMATIC is meaningless in AP mode */
512		if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
513			return;
514		if (sdata->u.ap.driver_smps_mode == smps_mode)
515			return;
516		sdata->u.ap.driver_smps_mode = smps_mode;
517		ieee80211_queue_work(&sdata->local->hw,
518				     &sdata->u.ap.request_smps_work);
519	}
520}
521/* this might change ... don't want non-open drivers using it */
522EXPORT_SYMBOL_GPL(ieee80211_request_smps);
523