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 static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
  23                                   struct ieee80211_sta_ht_cap *ht_cap,
  24                                   u16 flag)
  25 {
  26         __le16 le_flag = cpu_to_le16(flag);
  27         if (sdata->u.mgd.ht_capa_mask.cap_info & le_flag) {
  28                 if (!(sdata->u.mgd.ht_capa.cap_info & le_flag))
  29                         ht_cap->cap &= ~flag;
  30         }
  31 }
  32
  33 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
  34                                      struct ieee80211_sta_ht_cap *ht_cap)
  35 {
  36         u8 *scaps = (u8 *)(&sdata->u.mgd.ht_capa.mcs.rx_mask);
  37         u8 *smask = (u8 *)(&sdata->u.mgd.ht_capa_mask.mcs.rx_mask);
  38         int i;
  39
  40         if (sdata->vif.type != NL80211_IFTYPE_STATION) {
  41                 /* AP interfaces call this code when adding new stations,
  42                  * so just silently ignore non station interfaces.
  43                  */
  44                 return;
  45         }
  46
  47         /* NOTE:  If you add more over-rides here, update register_hw
  48          * ht_capa_mod_msk logic in main.c as well.
  49          * And, if this method can ever change ht_cap.ht_supported, fix
  50          * the check in ieee80211_add_ht_ie.
  51          */
  52
  53         /* check for HT over-rides, MCS rates first. */
  54         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  55                 u8 m = smask[i];
  56                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  57                 /* Add back rates that are supported */
  58                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  59         }
  60
  61         /* Force removal of HT-40 capabilities? */
  62         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  63         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
  64
  65         /* Allow user to disable the max-AMSDU bit. */
  66         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
  67
  68         /* Allow user to decrease AMPDU factor */
  69         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  70             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  71                 u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
  72                         & IEEE80211_HT_AMPDU_PARM_FACTOR;
  73                 if (n < ht_cap->ampdu_factor)
  74                         ht_cap->ampdu_factor = n;
  75         }
  76
  77         /* Allow the user to increase AMPDU density. */
  78         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  79             IEEE80211_HT_AMPDU_PARM_DENSITY) {
  80                 u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
  81                         IEEE80211_HT_AMPDU_PARM_DENSITY)
  82                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
  83                 if (n > ht_cap->ampdu_density)
  84                         ht_cap->ampdu_density = n;
  85         }
  86 }
  87
  88
  89 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
  90                                        struct ieee80211_supported_band *sband,
  91                                        struct ieee80211_ht_cap *ht_cap_ie,
  92                                        struct ieee80211_sta_ht_cap *ht_cap)
  93 {
  94         u8 ampdu_info, tx_mcs_set_cap;
  95         int i, max_tx_streams;
  96
  97         BUG_ON(!ht_cap);
  98
  99         memset(ht_cap, 0, sizeof(*ht_cap));
 100
 101         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 102                 return;
 103
 104         ht_cap->ht_supported = true;
 105
 106         /*
 107          * The bits listed in this expression should be
 108          * the same for the peer and us, if the station
 109          * advertises more then we can't use those thus
 110          * we mask them out.
 111          */
 112         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
 113                 (sband->ht_cap.cap |
 114                  ~(IEEE80211_HT_CAP_LDPC_CODING |
 115                    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 116                    IEEE80211_HT_CAP_GRN_FLD |
 117                    IEEE80211_HT_CAP_SGI_20 |
 118                    IEEE80211_HT_CAP_SGI_40 |
 119                    IEEE80211_HT_CAP_DSSSCCK40));
 120         /*
 121          * The STBC bits are asymmetric -- if we don't have
 122          * TX then mask out the peer's RX and vice versa.
 123          */
 124         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 125                 ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
 126         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 127                 ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
 128
 129         ampdu_info = ht_cap_ie->ampdu_params_info;
 130         ht_cap->ampdu_factor =
 131                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 132         ht_cap->ampdu_density =
 133                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 134
 135         /* own MCS TX capabilities */
 136         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
 137
 138         /* Copy peer MCS TX capabilities, the driver might need them. */
 139         ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
 140
 141         /* can we TX with MCS rates? */
 142         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 143                 return;
 144
 145         /* Counting from 0, therefore +1 */
 146         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 147                 max_tx_streams =
 148                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 149                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 150         else
 151                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 152
 153         /*
 154          * 802.11n-2009 20.3.5 / 20.6 says:
 155          * - indices 0 to 7 and 32 are single spatial stream
 156          * - 8 to 31 are multiple spatial streams using equal modulation
 157          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 158          * - remainder are multiple spatial streams using unequal modulation
 159          */
 160         for (i = 0; i < max_tx_streams; i++)
 161                 ht_cap->mcs.rx_mask[i] =
 162                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 163
 164         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 165                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 166                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 167                         ht_cap->mcs.rx_mask[i] =
 168                                 sband->ht_cap.mcs.rx_mask[i] &
 169                                         ht_cap_ie->mcs.rx_mask[i];
 170
 171         /* handle MCS rate 32 too */
 172         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 173                 ht_cap->mcs.rx_mask[32/8] |= 1;
 174
 175         /*
 176          * If user has specified capability over-rides, take care
 177          * of that here.
 178          */
 179         ieee80211_apply_htcap_overrides(sdata, ht_cap);
 180 }
 181
 182 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
 183 {
 184         int i;
 185
 186         cancel_work_sync(&sta->ampdu_mlme.work);
 187
 188         for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
 189                 __ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
 190                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 191                                                WLAN_REASON_QSTA_LEAVE_QBSS, tx);
 192         }
 193 }
 194
 195 void ieee80211_ba_session_work(struct work_struct *work)
 196 {
 197         struct sta_info *sta =
 198                 container_of(work, struct sta_info, ampdu_mlme.work);
 199         struct tid_ampdu_tx *tid_tx;
 200         int tid;
 201
 202         /*
 203          * When this flag is set, new sessions should be
 204          * blocked, and existing sessions will be torn
 205          * down by the code that set the flag, so this
 206          * need not run.
 207          */
 208         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 209                 return;
 210
 211         mutex_lock(&sta->ampdu_mlme.mtx);
 212         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 213                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 214                         ___ieee80211_stop_rx_ba_session(
 215                                 sta, tid, WLAN_BACK_RECIPIENT,
 216                                 WLAN_REASON_QSTA_TIMEOUT, true);
 217
 218                 if (test_and_clear_bit(tid,
 219                                        sta->ampdu_mlme.tid_rx_stop_requested))
 220                         ___ieee80211_stop_rx_ba_session(
 221                                 sta, tid, WLAN_BACK_RECIPIENT,
 222                                 WLAN_REASON_UNSPECIFIED, true);
 223
 224                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 225                 if (tid_tx) {
 226                         /*
 227                          * Assign it over to the normal tid_tx array
 228                          * where it "goes live".
 229                          */
 230                         spin_lock_bh(&sta->lock);
 231
 232                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 233                         /* could there be a race? */
 234                         if (sta->ampdu_mlme.tid_tx[tid])
 235                                 kfree(tid_tx);
 236                         else
 237                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 238                         spin_unlock_bh(&sta->lock);
 239
 240                         ieee80211_tx_ba_session_handle_start(sta, tid);
 241                         continue;
 242                 }
 243
 244                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 245                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 246                                                  &tid_tx->state))
 247                         ___ieee80211_stop_tx_ba_session(sta, tid,
 248                                                         WLAN_BACK_INITIATOR,
 249                                                         true);
 250         }
 251         mutex_unlock(&sta->ampdu_mlme.mtx);
 252 }
 253
 254 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 255                           const u8 *da, u16 tid,
 256                           u16 initiator, u16 reason_code)
 257 {
 258         struct ieee80211_local *local = sdata->local;
 259         struct sk_buff *skb;
 260         struct ieee80211_mgmt *mgmt;
 261         u16 params;
 262
 263         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 264         if (!skb)
 265                 return;
 266
 267         skb_reserve(skb, local->hw.extra_tx_headroom);
 268         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 269         memset(mgmt, 0, 24);
 270         memcpy(mgmt->da, da, ETH_ALEN);
 271         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 272         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 273             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 274             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 275                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 276         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 277                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 278         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 279                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 280
 281         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 282                                           IEEE80211_STYPE_ACTION);
 283
 284         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 285
 286         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 287         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 288         params = (u16)(initiator << 11);        /* bit 11 initiator */
 289         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 290
 291         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 292         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 293
 294         ieee80211_tx_skb_tid(sdata, skb, tid);
 295 }
 296
 297 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 298                              struct sta_info *sta,
 299                              struct ieee80211_mgmt *mgmt, size_t len)
 300 {
 301         u16 tid, params;
 302         u16 initiator;
 303
 304         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 305         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 306         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 307
 308         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 309                            mgmt->sa, initiator ? "initiator" : "recipient",
 310                            tid,
 311                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 312
 313         if (initiator == WLAN_BACK_INITIATOR)
 314                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 315                                                true);
 316         else
 317                 __ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 318                                                true);
 319 }
 320
 321 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 322                                enum ieee80211_smps_mode smps, const u8 *da,
 323                                const u8 *bssid)
 324 {
 325         struct ieee80211_local *local = sdata->local;
 326         struct sk_buff *skb;
 327         struct ieee80211_mgmt *action_frame;
 328
 329         /* 27 = header + category + action + smps mode */
 330         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 331         if (!skb)
 332                 return -ENOMEM;
 333
 334         skb_reserve(skb, local->hw.extra_tx_headroom);
 335         action_frame = (void *)skb_put(skb, 27);
 336         memcpy(action_frame->da, da, ETH_ALEN);
 337         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 338         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 339         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 340                                                   IEEE80211_STYPE_ACTION);
 341         action_frame->u.action.category = WLAN_CATEGORY_HT;
 342         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 343         switch (smps) {
 344         case IEEE80211_SMPS_AUTOMATIC:
 345         case IEEE80211_SMPS_NUM_MODES:
 346                 WARN_ON(1);
 347         case IEEE80211_SMPS_OFF:
 348                 action_frame->u.action.u.ht_smps.smps_control =
 349                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 350                 break;
 351         case IEEE80211_SMPS_STATIC:
 352                 action_frame->u.action.u.ht_smps.smps_control =
 353                                 WLAN_HT_SMPS_CONTROL_STATIC;
 354                 break;
 355         case IEEE80211_SMPS_DYNAMIC:
 356                 action_frame->u.action.u.ht_smps.smps_control =
 357                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 358                 break;
 359         }
 360
 361         /* we'll do more on status of this frame */
 362         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 363         ieee80211_tx_skb(sdata, skb);
 364
 365         return 0;
 366 }
 367
 368 void ieee80211_request_smps_work(struct work_struct *work)
 369 {
 370         struct ieee80211_sub_if_data *sdata =
 371                 container_of(work, struct ieee80211_sub_if_data,
 372                              u.mgd.request_smps_work);
 373
 374         mutex_lock(&sdata->u.mgd.mtx);
 375         __ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 376         mutex_unlock(&sdata->u.mgd.mtx);
 377 }
 378
 379 void ieee80211_request_smps(struct ieee80211_vif *vif,
 380                             enum ieee80211_smps_mode smps_mode)
 381 {
 382         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 383
 384         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 385                 return;
 386
 387         if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 388                 smps_mode = IEEE80211_SMPS_AUTOMATIC;
 389
 390         sdata->u.mgd.driver_smps_mode = smps_mode;
 391
 392         ieee80211_queue_work(&sdata->local->hw,
 393                              &sdata->u.mgd.request_smps_work);
 394 }
 395 /* this might change ... don't want non-open drivers using it */
 396 EXPORT_SYMBOL_GPL(ieee80211_request_smps);