ht.c revision 8ffcc704c963b4157391bd87a4544cdfd18b574d 
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
34void 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
110bool 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
262void 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
278void 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
338void 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_tid(sdata, skb, tid);
379}
380
381void 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
404int 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
451void 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
462void 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
475void 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 (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
486			smps_mode = IEEE80211_SMPS_AUTOMATIC;
487		if (sdata->u.mgd.driver_smps_mode == smps_mode)
488			return;
489		sdata->u.mgd.driver_smps_mode = smps_mode;
490		ieee80211_queue_work(&sdata->local->hw,
491				     &sdata->u.mgd.request_smps_work);
492	} else {
493		/* AUTOMATIC is meaningless in AP mode */
494		if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
495			return;
496		if (sdata->u.ap.driver_smps_mode == smps_mode)
497			return;
498		sdata->u.ap.driver_smps_mode = smps_mode;
499		ieee80211_queue_work(&sdata->local->hw,
500				     &sdata->u.ap.request_smps_work);
501	}
502}
503/* this might change ... don't want non-open drivers using it */
504EXPORT_SYMBOL_GPL(ieee80211_request_smps);
505