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_ht_cap *ht_capa,
  23                                   struct ieee80211_ht_cap *ht_capa_mask,
  24                                   struct ieee80211_sta_ht_cap *ht_cap,
  25                                   u16 flag)
  26 {
  27         __le16 le_flag = cpu_to_le16(flag);
  28         if (ht_capa_mask->cap_info & le_flag) {
  29                 if (!(ht_capa->cap_info & le_flag))
  30                         ht_cap->cap &= ~flag;
  31         }
  32 }
  33
  34 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
  35                                      struct ieee80211_sta_ht_cap *ht_cap)
  36 {
  37         struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
  38         u8 *scaps, *smask;
  39         int i;
  40
  41         if (!ht_cap->ht_supported)
  42                 return;
  43
  44         switch (sdata->vif.type) {
  45         case NL80211_IFTYPE_STATION:
  46                 ht_capa = &sdata->u.mgd.ht_capa;
  47                 ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
  48                 break;
  49         case NL80211_IFTYPE_ADHOC:
  50                 ht_capa = &sdata->u.ibss.ht_capa;
  51                 ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
  52                 break;
  53         default:
  54                 WARN_ON_ONCE(1);
  55                 return;
  56         }
  57
  58         scaps = (u8 *)(&ht_capa->mcs.rx_mask);
  59         smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
  60
  61         /* NOTE:  If you add more over-rides here, update register_hw
  62          * ht_capa_mod_msk logic in main.c as well.
  63          * And, if this method can ever change ht_cap.ht_supported, fix
  64          * the check in ieee80211_add_ht_ie.
  65          */
  66
  67         /* check for HT over-rides, MCS rates first. */
  68         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  69                 u8 m = smask[i];
  70                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  71                 /* Add back rates that are supported */
  72                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  73         }
  74
  75         /* Force removal of HT-40 capabilities? */
  76         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  77                               IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  78         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  79                               IEEE80211_HT_CAP_SGI_40);
  80
  81         /* Allow user to disable SGI-20 (SGI-40 is handled above) */
  82         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  83                               IEEE80211_HT_CAP_SGI_20);
  84
  85         /* Allow user to disable the max-AMSDU bit. */
  86         __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
  87                               IEEE80211_HT_CAP_MAX_AMSDU);
  88
  89         /* Allow user to decrease AMPDU factor */
  90         if (ht_capa_mask->ampdu_params_info &
  91             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  92                 u8 n = ht_capa->ampdu_params_info &
  93                        IEEE80211_HT_AMPDU_PARM_FACTOR;
  94                 if (n < ht_cap->ampdu_factor)
  95                         ht_cap->ampdu_factor = n;
  96         }
  97
  98         /* Allow the user to increase AMPDU density. */
  99         if (ht_capa_mask->ampdu_params_info &
 100             IEEE80211_HT_AMPDU_PARM_DENSITY) {
 101                 u8 n = (ht_capa->ampdu_params_info &
 102                         IEEE80211_HT_AMPDU_PARM_DENSITY)
 103                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
 104                 if (n > ht_cap->ampdu_density)
 105                         ht_cap->ampdu_density = n;
 106         }
 107 }
 108
 109
 110 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
 111                                        struct ieee80211_supported_band *sband,
 112                                        const struct ieee80211_ht_cap *ht_cap_ie,
 113                                        struct sta_info *sta)
 114 {
 115         struct ieee80211_sta_ht_cap ht_cap, own_cap;
 116         u8 ampdu_info, tx_mcs_set_cap;
 117         int i, max_tx_streams;
 118         bool changed;
 119         enum ieee80211_sta_rx_bandwidth bw;
 120         enum ieee80211_smps_mode smps_mode;
 121
 122         memset(&ht_cap, 0, sizeof(ht_cap));
 123
 124         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 125                 goto apply;
 126
 127         ht_cap.ht_supported = true;
 128
 129         own_cap = sband->ht_cap;
 130
 131         /*
 132          * If user has specified capability over-rides, take care
 133          * of that if the station we're setting up is the AP that
 134          * we advertised a restricted capability set to. Override
 135          * our own capabilities and then use those below.
 136          */
 137         if ((sdata->vif.type == NL80211_IFTYPE_STATION ||
 138              sdata->vif.type == NL80211_IFTYPE_ADHOC) &&
 139             !test_sta_flag(sta, WLAN_STA_TDLS_PEER))
 140                 ieee80211_apply_htcap_overrides(sdata, &own_cap);
 141
 142         /*
 143          * The bits listed in this expression should be
 144          * the same for the peer and us, if the station
 145          * advertises more then we can't use those thus
 146          * we mask them out.
 147          */
 148         ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
 149                 (own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
 150                                  IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 151                                  IEEE80211_HT_CAP_GRN_FLD |
 152                                  IEEE80211_HT_CAP_SGI_20 |
 153                                  IEEE80211_HT_CAP_SGI_40 |
 154                                  IEEE80211_HT_CAP_DSSSCCK40));
 155
 156         /*
 157          * The STBC bits are asymmetric -- if we don't have
 158          * TX then mask out the peer's RX and vice versa.
 159          */
 160         if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 161                 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
 162         if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 163                 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
 164
 165         ampdu_info = ht_cap_ie->ampdu_params_info;
 166         ht_cap.ampdu_factor =
 167                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 168         ht_cap.ampdu_density =
 169                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 170
 171         /* own MCS TX capabilities */
 172         tx_mcs_set_cap = own_cap.mcs.tx_params;
 173
 174         /* Copy peer MCS TX capabilities, the driver might need them. */
 175         ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
 176
 177         /* can we TX with MCS rates? */
 178         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 179                 goto apply;
 180
 181         /* Counting from 0, therefore +1 */
 182         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 183                 max_tx_streams =
 184                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 185                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 186         else
 187                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 188
 189         /*
 190          * 802.11n-2009 20.3.5 / 20.6 says:
 191          * - indices 0 to 7 and 32 are single spatial stream
 192          * - 8 to 31 are multiple spatial streams using equal modulation
 193          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 194          * - remainder are multiple spatial streams using unequal modulation
 195          */
 196         for (i = 0; i < max_tx_streams; i++)
 197                 ht_cap.mcs.rx_mask[i] =
 198                         own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 199
 200         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 201                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 202                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 203                         ht_cap.mcs.rx_mask[i] =
 204                                 own_cap.mcs.rx_mask[i] &
 205                                         ht_cap_ie->mcs.rx_mask[i];
 206
 207         /* handle MCS rate 32 too */
 208         if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 209                 ht_cap.mcs.rx_mask[32/8] |= 1;
 210
 211  apply:
 212         changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 213
 214         memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
 215
 216         switch (sdata->vif.bss_conf.chandef.width) {
 217         default:
 218                 WARN_ON_ONCE(1);
 219                 /* fall through */
 220         case NL80211_CHAN_WIDTH_20_NOHT:
 221         case NL80211_CHAN_WIDTH_20:
 222                 bw = IEEE80211_STA_RX_BW_20;
 223                 break;
 224         case NL80211_CHAN_WIDTH_40:
 225         case NL80211_CHAN_WIDTH_80:
 226         case NL80211_CHAN_WIDTH_80P80:
 227         case NL80211_CHAN_WIDTH_160:
 228                 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 229                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 230                 break;
 231         }
 232
 233         if (bw != sta->sta.bandwidth)
 234                 changed = true;
 235         sta->sta.bandwidth = bw;
 236
 237         sta->cur_max_bandwidth =
 238                 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 239                                 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
 240
 241         switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
 242                         >> IEEE80211_HT_CAP_SM_PS_SHIFT) {
 243         case WLAN_HT_CAP_SM_PS_INVALID:
 244         case WLAN_HT_CAP_SM_PS_STATIC:
 245                 smps_mode = IEEE80211_SMPS_STATIC;
 246                 break;
 247         case WLAN_HT_CAP_SM_PS_DYNAMIC:
 248                 smps_mode = IEEE80211_SMPS_DYNAMIC;
 249                 break;
 250         case WLAN_HT_CAP_SM_PS_DISABLED:
 251                 smps_mode = IEEE80211_SMPS_OFF;
 252                 break;
 253         }
 254
 255         if (smps_mode != sta->sta.smps_mode)
 256                 changed = true;
 257         sta->sta.smps_mode = smps_mode;
 258
 259         return changed;
 260 }
 261
 262 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 263                                          enum ieee80211_agg_stop_reason reason)
 264 {
 265         int i;
 266
 267         cancel_work_sync(&sta->ampdu_mlme.work);
 268
 269         for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
 270                 __ieee80211_stop_tx_ba_session(sta, i, reason);
 271                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 272                                                WLAN_REASON_QSTA_LEAVE_QBSS,
 273                                                reason != AGG_STOP_DESTROY_STA &&
 274                                                reason != AGG_STOP_PEER_REQUEST);
 275         }
 276 }
 277
 278 void ieee80211_ba_session_work(struct work_struct *work)
 279 {
 280         struct sta_info *sta =
 281                 container_of(work, struct sta_info, ampdu_mlme.work);
 282         struct tid_ampdu_tx *tid_tx;
 283         int tid;
 284
 285         /*
 286          * When this flag is set, new sessions should be
 287          * blocked, and existing sessions will be torn
 288          * down by the code that set the flag, so this
 289          * need not run.
 290          */
 291         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 292                 return;
 293
 294         mutex_lock(&sta->ampdu_mlme.mtx);
 295         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 296                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 297                         ___ieee80211_stop_rx_ba_session(
 298                                 sta, tid, WLAN_BACK_RECIPIENT,
 299                                 WLAN_REASON_QSTA_TIMEOUT, true);
 300
 301                 if (test_and_clear_bit(tid,
 302                                        sta->ampdu_mlme.tid_rx_stop_requested))
 303                         ___ieee80211_stop_rx_ba_session(
 304                                 sta, tid, WLAN_BACK_RECIPIENT,
 305                                 WLAN_REASON_UNSPECIFIED, true);
 306
 307                 spin_lock_bh(&sta->lock);
 308
 309                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 310                 if (tid_tx) {
 311                         /*
 312                          * Assign it over to the normal tid_tx array
 313                          * where it "goes live".
 314                          */
 315
 316                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 317                         /* could there be a race? */
 318                         if (sta->ampdu_mlme.tid_tx[tid])
 319                                 kfree(tid_tx);
 320                         else
 321                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 322                         spin_unlock_bh(&sta->lock);
 323
 324                         ieee80211_tx_ba_session_handle_start(sta, tid);
 325                         continue;
 326                 }
 327                 spin_unlock_bh(&sta->lock);
 328
 329                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 330                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 331                                                  &tid_tx->state))
 332                         ___ieee80211_stop_tx_ba_session(sta, tid,
 333                                                         AGG_STOP_LOCAL_REQUEST);
 334         }
 335         mutex_unlock(&sta->ampdu_mlme.mtx);
 336 }
 337
 338 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 339                           const u8 *da, u16 tid,
 340                           u16 initiator, u16 reason_code)
 341 {
 342         struct ieee80211_local *local = sdata->local;
 343         struct sk_buff *skb;
 344         struct ieee80211_mgmt *mgmt;
 345         u16 params;
 346
 347         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 348         if (!skb)
 349                 return;
 350
 351         skb_reserve(skb, local->hw.extra_tx_headroom);
 352         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 353         memset(mgmt, 0, 24);
 354         memcpy(mgmt->da, da, ETH_ALEN);
 355         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 356         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 357             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 358             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 359                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 360         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 361                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 362         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 363                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 364
 365         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 366                                           IEEE80211_STYPE_ACTION);
 367
 368         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 369
 370         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 371         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 372         params = (u16)(initiator << 11);        /* bit 11 initiator */
 373         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 374
 375         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 376         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 377
 378         ieee80211_tx_skb(sdata, skb);
 379 }
 380
 381 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 382                              struct sta_info *sta,
 383                              struct ieee80211_mgmt *mgmt, size_t len)
 384 {
 385         u16 tid, params;
 386         u16 initiator;
 387
 388         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 389         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 390         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 391
 392         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 393                            mgmt->sa, initiator ? "initiator" : "recipient",
 394                            tid,
 395                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 396
 397         if (initiator == WLAN_BACK_INITIATOR)
 398                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 399                                                true);
 400         else
 401                 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 402 }
 403
 404 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 405                                enum ieee80211_smps_mode smps, const u8 *da,
 406                                const u8 *bssid)
 407 {
 408         struct ieee80211_local *local = sdata->local;
 409         struct sk_buff *skb;
 410         struct ieee80211_mgmt *action_frame;
 411
 412         /* 27 = header + category + action + smps mode */
 413         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 414         if (!skb)
 415                 return -ENOMEM;
 416
 417         skb_reserve(skb, local->hw.extra_tx_headroom);
 418         action_frame = (void *)skb_put(skb, 27);
 419         memcpy(action_frame->da, da, ETH_ALEN);
 420         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 421         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 422         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 423                                                   IEEE80211_STYPE_ACTION);
 424         action_frame->u.action.category = WLAN_CATEGORY_HT;
 425         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 426         switch (smps) {
 427         case IEEE80211_SMPS_AUTOMATIC:
 428         case IEEE80211_SMPS_NUM_MODES:
 429                 WARN_ON(1);
 430         case IEEE80211_SMPS_OFF:
 431                 action_frame->u.action.u.ht_smps.smps_control =
 432                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 433                 break;
 434         case IEEE80211_SMPS_STATIC:
 435                 action_frame->u.action.u.ht_smps.smps_control =
 436                                 WLAN_HT_SMPS_CONTROL_STATIC;
 437                 break;
 438         case IEEE80211_SMPS_DYNAMIC:
 439                 action_frame->u.action.u.ht_smps.smps_control =
 440                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 441                 break;
 442         }
 443
 444         /* we'll do more on status of this frame */
 445         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 446         ieee80211_tx_skb(sdata, skb);
 447
 448         return 0;
 449 }
 450
 451 void ieee80211_request_smps_mgd_work(struct work_struct *work)
 452 {
 453         struct ieee80211_sub_if_data *sdata =
 454                 container_of(work, struct ieee80211_sub_if_data,
 455                              u.mgd.request_smps_work);
 456
 457         sdata_lock(sdata);
 458         __ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
 459         sdata_unlock(sdata);
 460 }
 461
 462 void ieee80211_request_smps_ap_work(struct work_struct *work)
 463 {
 464         struct ieee80211_sub_if_data *sdata =
 465                 container_of(work, struct ieee80211_sub_if_data,
 466                              u.ap.request_smps_work);
 467
 468         sdata_lock(sdata);
 469         if (sdata_dereference(sdata->u.ap.beacon, sdata))
 470                 __ieee80211_request_smps_ap(sdata,
 471                                             sdata->u.ap.driver_smps_mode);
 472         sdata_unlock(sdata);
 473 }
 474
 475 void ieee80211_request_smps(struct ieee80211_vif *vif,
 476                             enum ieee80211_smps_mode smps_mode)
 477 {
 478         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 479
 480         if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
 481                          vif->type != NL80211_IFTYPE_AP))
 482                 return;
 483
 484         if (vif->type == NL80211_IFTYPE_STATION) {
 485                 if (sdata->u.mgd.driver_smps_mode == smps_mode)
 486                         return;
 487                 sdata->u.mgd.driver_smps_mode = smps_mode;
 488                 ieee80211_queue_work(&sdata->local->hw,
 489                                      &sdata->u.mgd.request_smps_work);
 490         } else {
 491                 /* AUTOMATIC is meaningless in AP mode */
 492                 if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
 493                         return;
 494                 if (sdata->u.ap.driver_smps_mode == smps_mode)
 495                         return;
 496                 sdata->u.ap.driver_smps_mode = smps_mode;
 497                 ieee80211_queue_work(&sdata->local->hw,
 498                                      &sdata->u.ap.request_smps_work);
 499         }
 500 }
 501 /* this might change ... don't want non-open drivers using it */
 502 EXPORT_SYMBOL_GPL(ieee80211_request_smps);