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/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "rate.h"
  20
  21 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
  22                                        struct ieee80211_ht_cap *ht_cap_ie,
  23                                        struct ieee80211_sta_ht_cap *ht_cap)
  24 {
  25         u8 ampdu_info, tx_mcs_set_cap;
  26         int i, max_tx_streams;
  27
  28         BUG_ON(!ht_cap);
  29
  30         memset(ht_cap, 0, sizeof(*ht_cap));
  31
  32         if (!ht_cap_ie)
  33                 return;
  34
  35         ht_cap->ht_supported = true;
  36
  37         /*
  38          * The bits listed in this expression should be
  39          * the same for the peer and us, if the station
  40          * advertises more then we can't use those thus
  41          * we mask them out.
  42          */
  43         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
  44                 (sband->ht_cap.cap |
  45                  ~(IEEE80211_HT_CAP_LDPC_CODING |
  46                    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
  47                    IEEE80211_HT_CAP_GRN_FLD |
  48                    IEEE80211_HT_CAP_SGI_20 |
  49                    IEEE80211_HT_CAP_SGI_40 |
  50                    IEEE80211_HT_CAP_DSSSCCK40));
  51         /*
  52          * The STBC bits are asymmetric -- if we don't have
  53          * TX then mask out the peer's RX and vice versa.
  54          */
  55         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
  56                 ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
  57         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
  58                 ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
  59
  60         ampdu_info = ht_cap_ie->ampdu_params_info;
  61         ht_cap->ampdu_factor =
  62                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
  63         ht_cap->ampdu_density =
  64                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
  65
  66         /* own MCS TX capabilities */
  67         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
  68
  69         /* can we TX with MCS rates? */
  70         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
  71                 return;
  72
  73         /* Counting from 0, therefore +1 */
  74         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
  75                 max_tx_streams =
  76                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
  77                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
  78         else
  79                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
  80
  81         /*
  82          * 802.11n D5.0 20.3.5 / 20.6 says:
  83          * - indices 0 to 7 and 32 are single spatial stream
  84          * - 8 to 31 are multiple spatial streams using equal modulation
  85          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
  86          * - remainder are multiple spatial streams using unequal modulation
  87          */
  88         for (i = 0; i < max_tx_streams; i++)
  89                 ht_cap->mcs.rx_mask[i] =
  90                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
  91
  92         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
  93                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
  94                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
  95                         ht_cap->mcs.rx_mask[i] =
  96                                 sband->ht_cap.mcs.rx_mask[i] &
  97                                         ht_cap_ie->mcs.rx_mask[i];
  98
  99         /* handle MCS rate 32 too */
 100         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 101                 ht_cap->mcs.rx_mask[32/8] |= 1;
 102 }
 103
 104 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta)
 105 {
 106         int i;
 107
 108         for (i = 0; i <  STA_TID_NUM; i++) {
 109                 __ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR);
 110                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 111                                                WLAN_REASON_QSTA_LEAVE_QBSS);
 112         }
 113 }
 114
 115 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 116                           const u8 *da, u16 tid,
 117                           u16 initiator, u16 reason_code)
 118 {
 119         struct ieee80211_local *local = sdata->local;
 120         struct sk_buff *skb;
 121         struct ieee80211_mgmt *mgmt;
 122         u16 params;
 123
 124         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 125
 126         if (!skb) {
 127                 printk(KERN_ERR "%s: failed to allocate buffer "
 128                                         "for delba frame\n", sdata->dev->name);
 129                 return;
 130         }
 131
 132         skb_reserve(skb, local->hw.extra_tx_headroom);
 133         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 134         memset(mgmt, 0, 24);
 135         memcpy(mgmt->da, da, ETH_ALEN);
 136         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 137         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 138             sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
 139                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
 140         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 141                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 142
 143         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 144                                           IEEE80211_STYPE_ACTION);
 145
 146         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 147
 148         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 149         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 150         params = (u16)(initiator << 11);        /* bit 11 initiator */
 151         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 152
 153         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 154         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 155
 156         ieee80211_tx_skb(sdata, skb);
 157 }
 158
 159 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 160                              struct sta_info *sta,
 161                              struct ieee80211_mgmt *mgmt, size_t len)
 162 {
 163         u16 tid, params;
 164         u16 initiator;
 165
 166         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 167         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 168         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 169
 170 #ifdef CONFIG_MAC80211_HT_DEBUG
 171         if (net_ratelimit())
 172                 printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
 173                         mgmt->sa, initiator ? "initiator" : "recipient", tid,
 174                         le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 175 #endif /* CONFIG_MAC80211_HT_DEBUG */
 176
 177         if (initiator == WLAN_BACK_INITIATOR)
 178                 ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
 179                                                  WLAN_BACK_INITIATOR, 0);
 180         else { /* WLAN_BACK_RECIPIENT */
 181                 spin_lock_bh(&sta->lock);
 182                 if (sta->ampdu_mlme.tid_state_tx[tid] & HT_ADDBA_REQUESTED_MSK)
 183                         ___ieee80211_stop_tx_ba_session(sta, tid,
 184                                                         WLAN_BACK_RECIPIENT);
 185                 spin_unlock_bh(&sta->lock);
 186         }
 187 }