net/mac80211/ht.c

   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 }