linux/net/mac80211/ht.c
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   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
  22void 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 */
  91u32 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
 169void 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
 180void 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
 224void 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