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 SGI-20 (SGI-40 is handled above) */
  66         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_20);
  67
  68         /* Allow user to disable the max-AMSDU bit. */
  69         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
  70
  71         /* Allow user to decrease AMPDU factor */
  72         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  73             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  74                 u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
  75                         & IEEE80211_HT_AMPDU_PARM_FACTOR;
  76                 if (n < ht_cap->ampdu_factor)
  77                         ht_cap->ampdu_factor = n;
  78         }
  79
  80         /* Allow the user to increase AMPDU density. */
  81         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  82             IEEE80211_HT_AMPDU_PARM_DENSITY) {
  83                 u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
  84                         IEEE80211_HT_AMPDU_PARM_DENSITY)
  85                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
  86                 if (n > ht_cap->ampdu_density)
  87                         ht_cap->ampdu_density = n;
  88         }
  89 }
  90
  91
  92 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
  93                                        struct ieee80211_supported_band *sband,
  94                                        struct ieee80211_ht_cap *ht_cap_ie,
  95                                        struct ieee80211_sta_ht_cap *ht_cap)
  96 {
  97         u8 ampdu_info, tx_mcs_set_cap;
  98         int i, max_tx_streams;
  99
 100         BUG_ON(!ht_cap);
 101
 102         memset(ht_cap, 0, sizeof(*ht_cap));
 103
 104         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 105                 return;
 106
 107         ht_cap->ht_supported = true;
 108
 109         /*
 110          * The bits listed in this expression should be
 111          * the same for the peer and us, if the station
 112          * advertises more then we can't use those thus
 113          * we mask them out.
 114          */
 115         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
 116                 (sband->ht_cap.cap |
 117                  ~(IEEE80211_HT_CAP_LDPC_CODING |
 118                    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 119                    IEEE80211_HT_CAP_GRN_FLD |
 120                    IEEE80211_HT_CAP_SGI_20 |
 121                    IEEE80211_HT_CAP_SGI_40 |
 122                    IEEE80211_HT_CAP_DSSSCCK40));
 123         /*
 124          * The STBC bits are asymmetric -- if we don't have
 125          * TX then mask out the peer's RX and vice versa.
 126          */
 127         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 128                 ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
 129         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 130                 ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
 131
 132         ampdu_info = ht_cap_ie->ampdu_params_info;
 133         ht_cap->ampdu_factor =
 134                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 135         ht_cap->ampdu_density =
 136                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 137
 138         /* own MCS TX capabilities */
 139         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
 140
 141         /* Copy peer MCS TX capabilities, the driver might need them. */
 142         ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
 143
 144         /* can we TX with MCS rates? */
 145         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 146                 return;
 147
 148         /* Counting from 0, therefore +1 */
 149         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 150                 max_tx_streams =
 151                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 152                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 153         else
 154                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 155
 156         /*
 157          * 802.11n-2009 20.3.5 / 20.6 says:
 158          * - indices 0 to 7 and 32 are single spatial stream
 159          * - 8 to 31 are multiple spatial streams using equal modulation
 160          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 161          * - remainder are multiple spatial streams using unequal modulation
 162          */
 163         for (i = 0; i < max_tx_streams; i++)
 164                 ht_cap->mcs.rx_mask[i] =
 165                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 166
 167         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 168                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 169                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 170                         ht_cap->mcs.rx_mask[i] =
 171                                 sband->ht_cap.mcs.rx_mask[i] &
 172                                         ht_cap_ie->mcs.rx_mask[i];
 173
 174         /* handle MCS rate 32 too */
 175         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 176                 ht_cap->mcs.rx_mask[32/8] |= 1;
 177
 178         /*
 179          * If user has specified capability over-rides, take care
 180          * of that here.
 181          */
 182         ieee80211_apply_htcap_overrides(sdata, ht_cap);
 183 }
 184
 185 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
 186                                          enum ieee80211_agg_stop_reason reason)
 187 {
 188         int i;
 189
 190         cancel_work_sync(&sta->ampdu_mlme.work);
 191
 192         for (i = 0; i <  IEEE80211_NUM_TIDS; i++) {
 193                 __ieee80211_stop_tx_ba_session(sta, i, reason);
 194                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 195                                                WLAN_REASON_QSTA_LEAVE_QBSS,
 196                                                reason != AGG_STOP_DESTROY_STA &&
 197                                                reason != AGG_STOP_PEER_REQUEST);
 198         }
 199 }
 200
 201 void ieee80211_ba_session_work(struct work_struct *work)
 202 {
 203         struct sta_info *sta =
 204                 container_of(work, struct sta_info, ampdu_mlme.work);
 205         struct tid_ampdu_tx *tid_tx;
 206         int tid;
 207
 208         /*
 209          * When this flag is set, new sessions should be
 210          * blocked, and existing sessions will be torn
 211          * down by the code that set the flag, so this
 212          * need not run.
 213          */
 214         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 215                 return;
 216
 217         mutex_lock(&sta->ampdu_mlme.mtx);
 218         for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
 219                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 220                         ___ieee80211_stop_rx_ba_session(
 221                                 sta, tid, WLAN_BACK_RECIPIENT,
 222                                 WLAN_REASON_QSTA_TIMEOUT, true);
 223
 224                 if (test_and_clear_bit(tid,
 225                                        sta->ampdu_mlme.tid_rx_stop_requested))
 226                         ___ieee80211_stop_rx_ba_session(
 227                                 sta, tid, WLAN_BACK_RECIPIENT,
 228                                 WLAN_REASON_UNSPECIFIED, true);
 229
 230                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 231                 if (tid_tx) {
 232                         /*
 233                          * Assign it over to the normal tid_tx array
 234                          * where it "goes live".
 235                          */
 236                         spin_lock_bh(&sta->lock);
 237
 238                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 239                         /* could there be a race? */
 240                         if (sta->ampdu_mlme.tid_tx[tid])
 241                                 kfree(tid_tx);
 242                         else
 243                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 244                         spin_unlock_bh(&sta->lock);
 245
 246                         ieee80211_tx_ba_session_handle_start(sta, tid);
 247                         continue;
 248                 }
 249
 250                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 251                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 252                                                  &tid_tx->state))
 253                         ___ieee80211_stop_tx_ba_session(sta, tid,
 254                                                         AGG_STOP_LOCAL_REQUEST);
 255         }
 256         mutex_unlock(&sta->ampdu_mlme.mtx);
 257 }
 258
 259 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 260                           const u8 *da, u16 tid,
 261                           u16 initiator, u16 reason_code)
 262 {
 263         struct ieee80211_local *local = sdata->local;
 264         struct sk_buff *skb;
 265         struct ieee80211_mgmt *mgmt;
 266         u16 params;
 267
 268         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 269         if (!skb)
 270                 return;
 271
 272         skb_reserve(skb, local->hw.extra_tx_headroom);
 273         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 274         memset(mgmt, 0, 24);
 275         memcpy(mgmt->da, da, ETH_ALEN);
 276         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 277         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 278             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 279             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 280                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 281         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 282                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 283         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 284                 memcpy(mgmt->bssid, sdata->u.ibss.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_tid(sdata, skb, tid);
 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         ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
 314                            mgmt->sa, initiator ? "initiator" : "recipient",
 315                            tid,
 316                            le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 317
 318         if (initiator == WLAN_BACK_INITIATOR)
 319                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 320                                                true);
 321         else
 322                 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
 323 }
 324
 325 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 326                                enum ieee80211_smps_mode smps, const u8 *da,
 327                                const u8 *bssid)
 328 {
 329         struct ieee80211_local *local = sdata->local;
 330         struct sk_buff *skb;
 331         struct ieee80211_mgmt *action_frame;
 332
 333         /* 27 = header + category + action + smps mode */
 334         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 335         if (!skb)
 336                 return -ENOMEM;
 337
 338         skb_reserve(skb, local->hw.extra_tx_headroom);
 339         action_frame = (void *)skb_put(skb, 27);
 340         memcpy(action_frame->da, da, ETH_ALEN);
 341         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 342         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 343         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 344                                                   IEEE80211_STYPE_ACTION);
 345         action_frame->u.action.category = WLAN_CATEGORY_HT;
 346         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 347         switch (smps) {
 348         case IEEE80211_SMPS_AUTOMATIC:
 349         case IEEE80211_SMPS_NUM_MODES:
 350                 WARN_ON(1);
 351         case IEEE80211_SMPS_OFF:
 352                 action_frame->u.action.u.ht_smps.smps_control =
 353                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 354                 break;
 355         case IEEE80211_SMPS_STATIC:
 356                 action_frame->u.action.u.ht_smps.smps_control =
 357                                 WLAN_HT_SMPS_CONTROL_STATIC;
 358                 break;
 359         case IEEE80211_SMPS_DYNAMIC:
 360                 action_frame->u.action.u.ht_smps.smps_control =
 361                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 362                 break;
 363         }
 364
 365         /* we'll do more on status of this frame */
 366         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 367         ieee80211_tx_skb(sdata, skb);
 368
 369         return 0;
 370 }
 371
 372 void ieee80211_request_smps_work(struct work_struct *work)
 373 {
 374         struct ieee80211_sub_if_data *sdata =
 375                 container_of(work, struct ieee80211_sub_if_data,
 376                              u.mgd.request_smps_work);
 377
 378         mutex_lock(&sdata->u.mgd.mtx);
 379         __ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 380         mutex_unlock(&sdata->u.mgd.mtx);
 381 }
 382
 383 void ieee80211_request_smps(struct ieee80211_vif *vif,
 384                             enum ieee80211_smps_mode smps_mode)
 385 {
 386         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 387
 388         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 389                 return;
 390
 391         if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 392                 smps_mode = IEEE80211_SMPS_AUTOMATIC;
 393
 394         sdata->u.mgd.driver_smps_mode = smps_mode;
 395
 396         ieee80211_queue_work(&sdata->local->hw,
 397                              &sdata->u.mgd.request_smps_work);
 398 }
 399 /* this might change ... don't want non-open drivers using it */
 400 EXPORT_SYMBOL_GPL(ieee80211_request_smps);