xref: /openbmc/linux/net/mac80211/ht.c (revision 82ced6fd)
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 2007-2008, 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 <net/wireless.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "rate.h"
21 
22 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
23 				       struct ieee80211_ht_cap *ht_cap_ie,
24 				       struct ieee80211_sta_ht_cap *ht_cap)
25 {
26 	u8 ampdu_info, tx_mcs_set_cap;
27 	int i, max_tx_streams;
28 
29 	BUG_ON(!ht_cap);
30 
31 	memset(ht_cap, 0, sizeof(*ht_cap));
32 
33 	if (!ht_cap_ie)
34 		return;
35 
36 	ht_cap->ht_supported = true;
37 
38 	ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) & sband->ht_cap.cap;
39 	ht_cap->cap &= ~IEEE80211_HT_CAP_SM_PS;
40 	ht_cap->cap |= sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS;
41 
42 	ampdu_info = ht_cap_ie->ampdu_params_info;
43 	ht_cap->ampdu_factor =
44 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
45 	ht_cap->ampdu_density =
46 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
47 
48 	/* own MCS TX capabilities */
49 	tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
50 
51 	/* can we TX with MCS rates? */
52 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
53 		return;
54 
55 	/* Counting from 0, therefore +1 */
56 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
57 		max_tx_streams =
58 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
59 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
60 	else
61 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
62 
63 	/*
64 	 * 802.11n D5.0 20.3.5 / 20.6 says:
65 	 * - indices 0 to 7 and 32 are single spatial stream
66 	 * - 8 to 31 are multiple spatial streams using equal modulation
67 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
68 	 * - remainder are multiple spatial streams using unequal modulation
69 	 */
70 	for (i = 0; i < max_tx_streams; i++)
71 		ht_cap->mcs.rx_mask[i] =
72 			sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
73 
74 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
75 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
76 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
77 			ht_cap->mcs.rx_mask[i] =
78 				sband->ht_cap.mcs.rx_mask[i] &
79 					ht_cap_ie->mcs.rx_mask[i];
80 
81 	/* handle MCS rate 32 too */
82 	if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
83 		ht_cap->mcs.rx_mask[32/8] |= 1;
84 }
85 
86 /*
87  * ieee80211_enable_ht should be called only after the operating band
88  * has been determined as ht configuration depends on the hw's
89  * HT abilities for a specific band.
90  */
91 u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
92 			struct ieee80211_ht_info *hti,
93 			u16 ap_ht_cap_flags)
94 {
95 	struct ieee80211_local *local = sdata->local;
96 	struct ieee80211_supported_band *sband;
97 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
98 	struct ieee80211_bss_ht_conf ht;
99 	struct sta_info *sta;
100 	u32 changed = 0;
101 	bool enable_ht = true, ht_changed;
102 	enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
103 
104 	sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
105 
106 	memset(&ht, 0, sizeof(ht));
107 
108 	/* HT is not supported */
109 	if (!sband->ht_cap.ht_supported)
110 		enable_ht = false;
111 
112 	/* check that channel matches the right operating channel */
113 	if (local->hw.conf.channel->center_freq !=
114 	    ieee80211_channel_to_frequency(hti->control_chan))
115 		enable_ht = false;
116 
117 	if (enable_ht) {
118 		channel_type = NL80211_CHAN_HT20;
119 
120 		if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
121 		    (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
122 		    (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
123 			switch(hti->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
124 			case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
125 				channel_type = NL80211_CHAN_HT40PLUS;
126 				break;
127 			case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
128 				channel_type = NL80211_CHAN_HT40MINUS;
129 				break;
130 			}
131 		}
132 	}
133 
134 	ht_changed = conf_is_ht(&local->hw.conf) != enable_ht ||
135 		     channel_type != local->hw.conf.channel_type;
136 
137 	local->oper_channel_type = channel_type;
138 
139 	if (ht_changed) {
140                 /* channel_type change automatically detected */
141 		ieee80211_hw_config(local, 0);
142 
143 		rcu_read_lock();
144 
145 		sta = sta_info_get(local, ifmgd->bssid);
146 		if (sta)
147 			rate_control_rate_update(local, sband, sta,
148 						 IEEE80211_RC_HT_CHANGED);
149 
150 		rcu_read_unlock();
151 
152         }
153 
154 	/* disable HT */
155 	if (!enable_ht)
156 		return 0;
157 
158 	ht.operation_mode = le16_to_cpu(hti->operation_mode);
159 
160 	/* if bss configuration changed store the new one */
161 	if (memcmp(&sdata->vif.bss_conf.ht, &ht, sizeof(ht))) {
162 		changed |= BSS_CHANGED_HT;
163 		sdata->vif.bss_conf.ht = ht;
164 	}
165 
166 	return changed;
167 }
168 
169 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta)
170 {
171 	int i;
172 
173 	for (i = 0; i <  STA_TID_NUM; i++) {
174 		__ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR);
175 		__ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
176 					       WLAN_REASON_QSTA_LEAVE_QBSS);
177 	}
178 }
179 
180 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
181 			  const u8 *da, u16 tid,
182 			  u16 initiator, u16 reason_code)
183 {
184 	struct ieee80211_local *local = sdata->local;
185 	struct sk_buff *skb;
186 	struct ieee80211_mgmt *mgmt;
187 	u16 params;
188 
189 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
190 
191 	if (!skb) {
192 		printk(KERN_ERR "%s: failed to allocate buffer "
193 					"for delba frame\n", sdata->dev->name);
194 		return;
195 	}
196 
197 	skb_reserve(skb, local->hw.extra_tx_headroom);
198 	mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
199 	memset(mgmt, 0, 24);
200 	memcpy(mgmt->da, da, ETH_ALEN);
201 	memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
202 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
203 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
204 		memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
205 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
206 		memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
207 
208 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
209 					  IEEE80211_STYPE_ACTION);
210 
211 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
212 
213 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
214 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
215 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
216 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
217 
218 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
219 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
220 
221 	ieee80211_tx_skb(sdata, skb, 1);
222 }
223 
224 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
225 			     struct sta_info *sta,
226 			     struct ieee80211_mgmt *mgmt, size_t len)
227 {
228 	struct ieee80211_local *local = sdata->local;
229 	u16 tid, params;
230 	u16 initiator;
231 
232 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
233 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
234 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
235 
236 #ifdef CONFIG_MAC80211_HT_DEBUG
237 	if (net_ratelimit())
238 		printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
239 			mgmt->sa, initiator ? "initiator" : "recipient", tid,
240 			mgmt->u.action.u.delba.reason_code);
241 #endif /* CONFIG_MAC80211_HT_DEBUG */
242 
243 	if (initiator == WLAN_BACK_INITIATOR)
244 		ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
245 						 WLAN_BACK_INITIATOR, 0);
246 	else { /* WLAN_BACK_RECIPIENT */
247 		spin_lock_bh(&sta->lock);
248 		sta->ampdu_mlme.tid_state_tx[tid] =
249 				HT_AGG_STATE_OPERATIONAL;
250 		spin_unlock_bh(&sta->lock);
251 		ieee80211_stop_tx_ba_session(&local->hw, sta->sta.addr, tid,
252 					     WLAN_BACK_RECIPIENT);
253 	}
254 }
255