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 2007-2010, 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
  22 bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata)
  23 {
  24         const __le16 flg = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  25         if ((sdata->u.mgd.ht_capa_mask.cap_info & flg) &&
  26             !(sdata->u.mgd.ht_capa.cap_info & flg))
  27                 return true;
  28         return false;
  29 }
  30
  31 void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
  32                            struct ieee80211_sta_ht_cap *ht_cap,
  33                            u16 flag)
  34 {
  35         __le16 le_flag = cpu_to_le16(flag);
  36         if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
  37                 if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
  38                         ht_cap->cap &= ~flag;
  39         }
  40 }
  41
  42 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
  43                                      struct ieee80211_sta_ht_cap *ht_cap)
  44 {
  45         u8 *scaps = (u8 *)(&sdata->u.mgd.ht_capa.mcs.rx_mask);
  46         u8 *smask = (u8 *)(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
  47         int i;
  48
  49         if (sdata->vif.type != NL80211_IFTYPE_STATION) {
  50                 WARN_ON_ONCE(sdata->vif.type != NL80211_IFTYPE_STATION);
  51                 return;
  52         }
  53
  54         /* NOTE:  If you add more over-rides here, update register_hw
  55          * ht_capa_mod_msk logic in main.c as well.
  56          * And, if this method can ever change ht_cap.ht_supported, fix
  57          * the check in ieee80211_add_ht_ie.
  58          */
  59
  60         /* check for HT over-rides, MCS rates first. */
  61         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  62                 u8 m = smask[i];
  63                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  64                 /* Add back rates that are supported */
  65                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  66         }
  67
  68         /* Force removal of HT-40 capabilities? */
  69         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  70         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
  71
  72         /* Allow user to disable the max-AMSDU bit. */
  73         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
  74
  75         /* Allow user to decrease AMPDU factor */
  76         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  77             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  78                 u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
  79                         & IEEE80211_HT_AMPDU_PARM_FACTOR;
  80                 if (n < ht_cap->ampdu_factor)
  81                         ht_cap->ampdu_factor = n;
  82         }
  83
  84         /* Allow the user to increase AMPDU density. */
  85         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  86             IEEE80211_HT_AMPDU_PARM_DENSITY) {
  87                 u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
  88                         IEEE80211_HT_AMPDU_PARM_DENSITY)
  89                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
  90                 if (n > ht_cap->ampdu_density)
  91                         ht_cap->ampdu_density = n;
  92         }
  93 }
  94
  95
  96 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
  97                                        struct ieee80211_supported_band *sband,
  98                                        struct ieee80211_ht_cap *ht_cap_ie,
  99                                        struct ieee80211_sta_ht_cap *ht_cap)
 100 {
 101         u8 ampdu_info, tx_mcs_set_cap;
 102         int i, max_tx_streams;
 103
 104         BUG_ON(!ht_cap);
 105
 106         memset(ht_cap, 0, sizeof(*ht_cap));
 107
 108         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 109                 return;
 110
 111         ht_cap->ht_supported = true;
 112
 113         /*
 114          * The bits listed in this expression should be
 115          * the same for the peer and us, if the station
 116          * advertises more then we can't use those thus
 117          * we mask them out.
 118          */
 119         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
 120                 (sband->ht_cap.cap |
 121                  ~(IEEE80211_HT_CAP_LDPC_CODING |
 122                    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 123                    IEEE80211_HT_CAP_GRN_FLD |
 124                    IEEE80211_HT_CAP_SGI_20 |
 125                    IEEE80211_HT_CAP_SGI_40 |
 126                    IEEE80211_HT_CAP_DSSSCCK40));
 127         /*
 128          * The STBC bits are asymmetric -- if we don't have
 129          * TX then mask out the peer's RX and vice versa.
 130          */
 131         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 132                 ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
 133         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 134                 ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
 135
 136         ampdu_info = ht_cap_ie->ampdu_params_info;
 137         ht_cap->ampdu_factor =
 138                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 139         ht_cap->ampdu_density =
 140                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 141
 142         /* own MCS TX capabilities */
 143         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
 144
 145         /* Copy peer MCS TX capabilities, the driver might need them. */
 146         ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
 147
 148         /* can we TX with MCS rates? */
 149         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 150                 return;
 151
 152         /* Counting from 0, therefore +1 */
 153         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 154                 max_tx_streams =
 155                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 156                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 157         else
 158                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 159
 160         /*
 161          * 802.11n-2009 20.3.5 / 20.6 says:
 162          * - indices 0 to 7 and 32 are single spatial stream
 163          * - 8 to 31 are multiple spatial streams using equal modulation
 164          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 165          * - remainder are multiple spatial streams using unequal modulation
 166          */
 167         for (i = 0; i < max_tx_streams; i++)
 168                 ht_cap->mcs.rx_mask[i] =
 169                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 170
 171         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 172                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 173                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 174                         ht_cap->mcs.rx_mask[i] =
 175                                 sband->ht_cap.mcs.rx_mask[i] &
 176                                         ht_cap_ie->mcs.rx_mask[i];
 177
 178         /* handle MCS rate 32 too */
 179         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 180                 ht_cap->mcs.rx_mask[32/8] |= 1;
 181
 182         /*
 183          * If user has specified capability over-rides, take care
 184          * of that here.
 185          */
 186         ieee80211_apply_htcap_overrides(sdata, ht_cap);
 187 }
 188
 189 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
 190 {
 191         int i;
 192
 193         cancel_work_sync(&sta->ampdu_mlme.work);
 194
 195         for (i = 0; i <  STA_TID_NUM; i++) {
 196                 __ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
 197                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 198                                                WLAN_REASON_QSTA_LEAVE_QBSS, tx);
 199         }
 200 }
 201
 202 void ieee80211_ba_session_work(struct work_struct *work)
 203 {
 204         struct sta_info *sta =
 205                 container_of(work, struct sta_info, ampdu_mlme.work);
 206         struct tid_ampdu_tx *tid_tx;
 207         int tid;
 208
 209         /*
 210          * When this flag is set, new sessions should be
 211          * blocked, and existing sessions will be torn
 212          * down by the code that set the flag, so this
 213          * need not run.
 214          */
 215         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 216                 return;
 217
 218         mutex_lock(&sta->ampdu_mlme.mtx);
 219         for (tid = 0; tid < STA_TID_NUM; tid++) {
 220                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 221                         ___ieee80211_stop_rx_ba_session(
 222                                 sta, tid, WLAN_BACK_RECIPIENT,
 223                                 WLAN_REASON_QSTA_TIMEOUT, true);
 224
 225                 if (test_and_clear_bit(tid,
 226                                        sta->ampdu_mlme.tid_rx_stop_requested))
 227                         ___ieee80211_stop_rx_ba_session(
 228                                 sta, tid, WLAN_BACK_RECIPIENT,
 229                                 WLAN_REASON_UNSPECIFIED, true);
 230
 231                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 232                 if (tid_tx) {
 233                         /*
 234                          * Assign it over to the normal tid_tx array
 235                          * where it "goes live".
 236                          */
 237                         spin_lock_bh(&sta->lock);
 238
 239                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 240                         /* could there be a race? */
 241                         if (sta->ampdu_mlme.tid_tx[tid])
 242                                 kfree(tid_tx);
 243                         else
 244                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 245                         spin_unlock_bh(&sta->lock);
 246
 247                         ieee80211_tx_ba_session_handle_start(sta, tid);
 248                         continue;
 249                 }
 250
 251                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 252                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 253                                                  &tid_tx->state))
 254                         ___ieee80211_stop_tx_ba_session(sta, tid,
 255                                                         WLAN_BACK_INITIATOR,
 256                                                         true);
 257         }
 258         mutex_unlock(&sta->ampdu_mlme.mtx);
 259 }
 260
 261 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 262                           const u8 *da, u16 tid,
 263                           u16 initiator, u16 reason_code)
 264 {
 265         struct ieee80211_local *local = sdata->local;
 266         struct sk_buff *skb;
 267         struct ieee80211_mgmt *mgmt;
 268         u16 params;
 269
 270         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 271         if (!skb)
 272                 return;
 273
 274         skb_reserve(skb, local->hw.extra_tx_headroom);
 275         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 276         memset(mgmt, 0, 24);
 277         memcpy(mgmt->da, da, ETH_ALEN);
 278         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 279         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 280             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 281             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 282                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 283         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 284                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 285
 286         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 287                                           IEEE80211_STYPE_ACTION);
 288
 289         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 290
 291         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 292         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 293         params = (u16)(initiator << 11);        /* bit 11 initiator */
 294         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 295
 296         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 297         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 298
 299         ieee80211_tx_skb(sdata, skb);
 300 }
 301
 302 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 303                              struct sta_info *sta,
 304                              struct ieee80211_mgmt *mgmt, size_t len)
 305 {
 306         u16 tid, params;
 307         u16 initiator;
 308
 309         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 310         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 311         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 312
 313 #ifdef CONFIG_MAC80211_HT_DEBUG
 314         if (net_ratelimit())
 315                 printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
 316                         mgmt->sa, initiator ? "initiator" : "recipient", tid,
 317                         le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 318 #endif /* CONFIG_MAC80211_HT_DEBUG */
 319
 320         if (initiator == WLAN_BACK_INITIATOR)
 321                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 322                                                true);
 323         else
 324                 __ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 325                                                true);
 326 }
 327
 328 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 329                                enum ieee80211_smps_mode smps, const u8 *da,
 330                                const u8 *bssid)
 331 {
 332         struct ieee80211_local *local = sdata->local;
 333         struct sk_buff *skb;
 334         struct ieee80211_mgmt *action_frame;
 335
 336         /* 27 = header + category + action + smps mode */
 337         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 338         if (!skb)
 339                 return -ENOMEM;
 340
 341         skb_reserve(skb, local->hw.extra_tx_headroom);
 342         action_frame = (void *)skb_put(skb, 27);
 343         memcpy(action_frame->da, da, ETH_ALEN);
 344         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 345         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 346         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 347                                                   IEEE80211_STYPE_ACTION);
 348         action_frame->u.action.category = WLAN_CATEGORY_HT;
 349         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 350         switch (smps) {
 351         case IEEE80211_SMPS_AUTOMATIC:
 352         case IEEE80211_SMPS_NUM_MODES:
 353                 WARN_ON(1);
 354         case IEEE80211_SMPS_OFF:
 355                 action_frame->u.action.u.ht_smps.smps_control =
 356                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 357                 break;
 358         case IEEE80211_SMPS_STATIC:
 359                 action_frame->u.action.u.ht_smps.smps_control =
 360                                 WLAN_HT_SMPS_CONTROL_STATIC;
 361                 break;
 362         case IEEE80211_SMPS_DYNAMIC:
 363                 action_frame->u.action.u.ht_smps.smps_control =
 364                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 365                 break;
 366         }
 367
 368         /* we'll do more on status of this frame */
 369         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 370         ieee80211_tx_skb(sdata, skb);
 371
 372         return 0;
 373 }
 374
 375 void ieee80211_request_smps_work(struct work_struct *work)
 376 {
 377         struct ieee80211_sub_if_data *sdata =
 378                 container_of(work, struct ieee80211_sub_if_data,
 379                              u.mgd.request_smps_work);
 380
 381         mutex_lock(&sdata->u.mgd.mtx);
 382         __ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 383         mutex_unlock(&sdata->u.mgd.mtx);
 384 }
 385
 386 void ieee80211_request_smps(struct ieee80211_vif *vif,
 387                             enum ieee80211_smps_mode smps_mode)
 388 {
 389         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 390
 391         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 392                 return;
 393
 394         if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 395                 smps_mode = IEEE80211_SMPS_AUTOMATIC;
 396
 397         sdata->u.mgd.driver_smps_mode = smps_mode;
 398
 399         ieee80211_queue_work(&sdata->local->hw,
 400                              &sdata->u.mgd.request_smps_work);
 401 }
 402 /* this might change ... don't want non-open drivers using it */
 403 EXPORT_SYMBOL_GPL(ieee80211_request_smps);