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 (!ht_cap->ht_supported)
  41                 return;
  42
  43         if (sdata->vif.type != NL80211_IFTYPE_STATION) {
  44                 /* AP interfaces call this code when adding new stations,
  45                  * so just silently ignore non station interfaces.
  46                  */
  47                 return;
  48         }
  49
  50         /* NOTE:  If you add more over-rides here, update register_hw
  51          * ht_capa_mod_msk logic in main.c as well.
  52          * And, if this method can ever change ht_cap.ht_supported, fix
  53          * the check in ieee80211_add_ht_ie.
  54          */
  55
  56         /* check for HT over-rides, MCS rates first. */
  57         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  58                 u8 m = smask[i];
  59                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  60                 /* Add back rates that are supported */
  61                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  62         }
  63
  64         /* Force removal of HT-40 capabilities? */
  65         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  66         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
  67
  68         /* Allow user to disable SGI-20 (SGI-40 is handled above) */
  69         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_20);
  70
  71         /* Allow user to disable the max-AMSDU bit. */
  72         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
  73
  74         /* Allow user to decrease AMPDU factor */
  75         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  76             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  77                 u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
  78                         & IEEE80211_HT_AMPDU_PARM_FACTOR;
  79                 if (n < ht_cap->ampdu_factor)
  80                         ht_cap->ampdu_factor = n;
  81         }
  82
  83         /* Allow the user to increase AMPDU density. */
  84         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  85             IEEE80211_HT_AMPDU_PARM_DENSITY) {
  86                 u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
  87                         IEEE80211_HT_AMPDU_PARM_DENSITY)
  88                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
  89                 if (n > ht_cap->ampdu_density)
  90                         ht_cap->ampdu_density = n;
  91         }
  92 }
  93
  94
  95 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
  96                                        struct ieee80211_supported_band *sband,
  97                                        struct ieee80211_ht_cap *ht_cap_ie,
  98                                        struct sta_info *sta)
  99 {
 100         struct ieee80211_sta_ht_cap ht_cap;
 101         u8 ampdu_info, tx_mcs_set_cap;
 102         int i, max_tx_streams;
 103         bool changed;
 104         enum ieee80211_sta_rx_bandwidth bw;
 105
 106         memset(&ht_cap, 0, sizeof(ht_cap));
 107
 108         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 109                 goto apply;
 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         /*
 129          * The STBC bits are asymmetric -- if we don't have
 130          * TX then mask out the peer's RX and vice versa.
 131          */
 132         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 133                 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
 134         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 135                 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
 136
 137         ampdu_info = ht_cap_ie->ampdu_params_info;
 138         ht_cap.ampdu_factor =
 139                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 140         ht_cap.ampdu_density =
 141                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 142
 143         /* own MCS TX capabilities */
 144         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
 145
 146         /* Copy peer MCS TX capabilities, the driver might need them. */
 147         ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
 148
 149         /* can we TX with MCS rates? */
 150         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 151                 goto apply;
 152
 153         /* Counting from 0, therefore +1 */
 154         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 155                 max_tx_streams =
 156                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 157                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 158         else
 159                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 160
 161         /*
 162          * 802.11n-2009 20.3.5 / 20.6 says:
 163          * - indices 0 to 7 and 32 are single spatial stream
 164          * - 8 to 31 are multiple spatial streams using equal modulation
 165          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 166          * - remainder are multiple spatial streams using unequal modulation
 167          */
 168         for (i = 0; i < max_tx_streams; i++)
 169                 ht_cap.mcs.rx_mask[i] =
 170                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 171
 172         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 173                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 174                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 175                         ht_cap.mcs.rx_mask[i] =
 176                                 sband->ht_cap.mcs.rx_mask[i] &
 177                                         ht_cap_ie->mcs.rx_mask[i];
 178
 179         /* handle MCS rate 32 too */
 180         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 181                 ht_cap.mcs.rx_mask[32/8] |= 1;
 182
 183  apply:
 184         /*
 185          * If user has specified capability over-rides, take care
 186          * of that here.
 187          */
 188         ieee80211_apply_htcap_overrides(sdata, &ht_cap);
 189
 190         changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 191
 192         memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 193
 194         switch (sdata->vif.bss_conf.chandef.width) {
 195         default:
 196                 WARN_ON_ONCE(1);
 197                 /* fall through */
 198         case NL80211_CHAN_WIDTH_20_NOHT:
 199         case NL80211_CHAN_WIDTH_20:
 200                 bw = IEEE80211_STA_RX_BW_20;
 201                 break;
 202         case NL80211_CHAN_WIDTH_40:
 203         case NL80211_CHAN_WIDTH_80:
 204         case NL80211_CHAN_WIDTH_80P80:
 205         case NL80211_CHAN_WIDTH_160:
 206                 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 207                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 208                 break;
 209         }
 210
 211         if (bw != sta->sta.bandwidth)
 212                 changed = true;
 213         sta->sta.bandwidth = bw;
 214
 215         sta->cur_max_bandwidth =
 216                 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 217                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 218
 219         return changed;
 220 }
 221
 222 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 223                                          enum ieee80211_agg_stop_reason reason)
 224 {
 225         int i;
 226
 227         cancel_work_sync(&sta->ampdu_mlme.work);
 228
 229         for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
 230                 __ieee80211_stop_tx_ba_session(sta, i, reason);
 231                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 232                                                WLAN_REASON_QSTA_LEAVE_QBSS,
 233                                                reason != AGG_STOP_DESTROY_STA &&
 234                                                reason != AGG_STOP_PEER_REQUEST);
 235         }
 236 }
 237
 238 void ieee80211_ba_session_work(struct work_struct *work)
 239 {
 240         struct sta_info *sta =
 241                 container_of(work, struct sta_info, ampdu_mlme.work);
 242         struct tid_ampdu_tx *tid_tx;
 243         int tid;
 244
 245         /*
 246          * When this flag is set, new sessions should be
 247          * blocked, and existing sessions will be torn
 248          * down by the code that set the flag, so this
 249          * need not run.
 250          */
 251         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 252                 return;
 253
 254         mutex_lock(&sta->ampdu_mlme.mtx);
 255         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 256                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 257                         ___ieee80211_stop_rx_ba_session(
 258                                 sta, tid, WLAN_BACK_RECIPIENT,
 259                                 WLAN_REASON_QSTA_TIMEOUT, true);
 260
 261                 if (test_and_clear_bit(tid,
 262                                        sta->ampdu_mlme.tid_rx_stop_requested))
 263                         ___ieee80211_stop_rx_ba_session(
 264                                 sta, tid, WLAN_BACK_RECIPIENT,
 265                                 WLAN_REASON_UNSPECIFIED, true);
 266
 267                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 268                 if (tid_tx) {
 269                         /*
 270                          * Assign it over to the normal tid_tx array
 271                          * where it "goes live".
 272                          */
 273                         spin_lock_bh(&sta->lock);
 274
 275                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 276                         /* could there be a race? */
 277                         if (sta->ampdu_mlme.tid_tx[tid])
 278                                 kfree(tid_tx);
 279                         else
 280                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 281                         spin_unlock_bh(&sta->lock);
 282
 283                         ieee80211_tx_ba_session_handle_start(sta, tid);
 284                         continue;
 285                 }
 286
 287                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 288                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 289                                                  &tid_tx->state))
 290                         ___ieee80211_stop_tx_ba_session(sta, tid,
 291                                                         AGG_STOP_LOCAL_REQUEST);
 292         }
 293         mutex_unlock(&sta->ampdu_mlme.mtx);
 294 }
 295
 296 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 297                           const u8 *da, u16 tid,
 298                           u16 initiator, u16 reason_code)
 299 {
 300         struct ieee80211_local *local = sdata->local;
 301         struct sk_buff *skb;
 302         struct ieee80211_mgmt *mgmt;
 303         u16 params;
 304
 305         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 306         if (!skb)
 307                 return;
 308
 309         skb_reserve(skb, local->hw.extra_tx_headroom);
 310         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 311         memset(mgmt, 0, 24);
 312         memcpy(mgmt->da, da, ETH_ALEN);
 313         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 314         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 315             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 316             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 317                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 318         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 319                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 320         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 321                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 322
 323         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 324                                           IEEE80211_STYPE_ACTION);
 325
 326         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 327
 328         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 329         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 330         params = (u16)(initiator << 11);        /* bit 11 initiator */
 331         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 332
 333         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 334         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 335
 336         ieee80211_tx_skb_tid(sdata, skb, tid);
 337 }
 338
 339 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 340                              struct sta_info *sta,
 341                              struct ieee80211_mgmt *mgmt, size_t len)
 342 {
 343         u16 tid, params;
 344         u16 initiator;
 345
 346         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 347         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 348         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 349
 350         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 351                            mgmt->sa, initiator ? "initiator" : "recipient",
 352                            tid,
 353                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 354
 355         if (initiator == WLAN_BACK_INITIATOR)
 356                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 357                                                true);
 358         else
 359                 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 360 }
 361
 362 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 363                                enum ieee80211_smps_mode smps, const u8 *da,
 364                                const u8 *bssid)
 365 {
 366         struct ieee80211_local *local = sdata->local;
 367         struct sk_buff *skb;
 368         struct ieee80211_mgmt *action_frame;
 369
 370         /* 27 = header + category + action + smps mode */
 371         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 372         if (!skb)
 373                 return -ENOMEM;
 374
 375         skb_reserve(skb, local->hw.extra_tx_headroom);
 376         action_frame = (void *)skb_put(skb, 27);
 377         memcpy(action_frame->da, da, ETH_ALEN);
 378         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 379         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 380         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 381                                                   IEEE80211_STYPE_ACTION);
 382         action_frame->u.action.category = WLAN_CATEGORY_HT;
 383         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 384         switch (smps) {
 385         case IEEE80211_SMPS_AUTOMATIC:
 386         case IEEE80211_SMPS_NUM_MODES:
 387                 WARN_ON(1);
 388         case IEEE80211_SMPS_OFF:
 389                 action_frame->u.action.u.ht_smps.smps_control =
 390                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 391                 break;
 392         case IEEE80211_SMPS_STATIC:
 393                 action_frame->u.action.u.ht_smps.smps_control =
 394                                 WLAN_HT_SMPS_CONTROL_STATIC;
 395                 break;
 396         case IEEE80211_SMPS_DYNAMIC:
 397                 action_frame->u.action.u.ht_smps.smps_control =
 398                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 399                 break;
 400         }
 401
 402         /* we'll do more on status of this frame */
 403         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 404         ieee80211_tx_skb(sdata, skb);
 405
 406         return 0;
 407 }
 408
 409 void ieee80211_request_smps_work(struct work_struct *work)
 410 {
 411         struct ieee80211_sub_if_data *sdata =
 412                 container_of(work, struct ieee80211_sub_if_data,
 413                              u.mgd.request_smps_work);
 414
 415         mutex_lock(&sdata->u.mgd.mtx);
 416         __ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 417         mutex_unlock(&sdata->u.mgd.mtx);
 418 }
 419
 420 void ieee80211_request_smps(struct ieee80211_vif *vif,
 421                             enum ieee80211_smps_mode smps_mode)
 422 {
 423         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 424
 425         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 426                 return;
 427
 428         if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 429                 smps_mode = IEEE80211_SMPS_AUTOMATIC;
 430
 431         if (sdata->u.mgd.driver_smps_mode == smps_mode)
 432                 return;
 433
 434         sdata->u.mgd.driver_smps_mode = smps_mode;
 435
 436         ieee80211_queue_work(&sdata->local->hw,
 437                              &sdata->u.mgd.request_smps_work);
 438 }
 439 /* this might change ... don't want non-open drivers using it */
 440 EXPORT_SYMBOL_GPL(ieee80211_request_smps);