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 static 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                 /* AP interfaces call this code when adding new stations,
  51                  * so just silently ignore non station interfaces.
  52                  */
  53                 return;
  54         }
  55
  56         /* NOTE:  If you add more over-rides here, update register_hw
  57          * ht_capa_mod_msk logic in main.c as well.
  58          * And, if this method can ever change ht_cap.ht_supported, fix
  59          * the check in ieee80211_add_ht_ie.
  60          */
  61
  62         /* check for HT over-rides, MCS rates first. */
  63         for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
  64                 u8 m = smask[i];
  65                 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
  66                 /* Add back rates that are supported */
  67                 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
  68         }
  69
  70         /* Force removal of HT-40 capabilities? */
  71         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SUP_WIDTH_20_40);
  72         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_SGI_40);
  73
  74         /* Allow user to disable the max-AMSDU bit. */
  75         __check_htcap_disable(sdata, ht_cap, IEEE80211_HT_CAP_MAX_AMSDU);
  76
  77         /* Allow user to decrease AMPDU factor */
  78         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  79             IEEE80211_HT_AMPDU_PARM_FACTOR) {
  80                 u8 n = sdata->u.mgd.ht_capa.ampdu_params_info
  81                         & IEEE80211_HT_AMPDU_PARM_FACTOR;
  82                 if (n < ht_cap->ampdu_factor)
  83                         ht_cap->ampdu_factor = n;
  84         }
  85
  86         /* Allow the user to increase AMPDU density. */
  87         if (sdata->u.mgd.ht_capa_mask.ampdu_params_info &
  88             IEEE80211_HT_AMPDU_PARM_DENSITY) {
  89                 u8 n = (sdata->u.mgd.ht_capa.ampdu_params_info &
  90                         IEEE80211_HT_AMPDU_PARM_DENSITY)
  91                         >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
  92                 if (n > ht_cap->ampdu_density)
  93                         ht_cap->ampdu_density = n;
  94         }
  95 }
  96
  97
  98 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
  99                                        struct ieee80211_supported_band *sband,
 100                                        struct ieee80211_ht_cap *ht_cap_ie,
 101                                        struct ieee80211_sta_ht_cap *ht_cap)
 102 {
 103         u8 ampdu_info, tx_mcs_set_cap;
 104         int i, max_tx_streams;
 105
 106         BUG_ON(!ht_cap);
 107
 108         memset(ht_cap, 0, sizeof(*ht_cap));
 109
 110         if (!ht_cap_ie || !sband->ht_cap.ht_supported)
 111                 return;
 112
 113         ht_cap->ht_supported = true;
 114
 115         /*
 116          * The bits listed in this expression should be
 117          * the same for the peer and us, if the station
 118          * advertises more then we can't use those thus
 119          * we mask them out.
 120          */
 121         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) &
 122                 (sband->ht_cap.cap |
 123                  ~(IEEE80211_HT_CAP_LDPC_CODING |
 124                    IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
 125                    IEEE80211_HT_CAP_GRN_FLD |
 126                    IEEE80211_HT_CAP_SGI_20 |
 127                    IEEE80211_HT_CAP_SGI_40 |
 128                    IEEE80211_HT_CAP_DSSSCCK40));
 129         /*
 130          * The STBC bits are asymmetric -- if we don't have
 131          * TX then mask out the peer's RX and vice versa.
 132          */
 133         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_TX_STBC))
 134                 ht_cap->cap &= ~IEEE80211_HT_CAP_RX_STBC;
 135         if (!(sband->ht_cap.cap & IEEE80211_HT_CAP_RX_STBC))
 136                 ht_cap->cap &= ~IEEE80211_HT_CAP_TX_STBC;
 137
 138         ampdu_info = ht_cap_ie->ampdu_params_info;
 139         ht_cap->ampdu_factor =
 140                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
 141         ht_cap->ampdu_density =
 142                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
 143
 144         /* own MCS TX capabilities */
 145         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
 146
 147         /* Copy peer MCS TX capabilities, the driver might need them. */
 148         ht_cap->mcs.tx_params = ht_cap_ie->mcs.tx_params;
 149
 150         /* can we TX with MCS rates? */
 151         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
 152                 return;
 153
 154         /* Counting from 0, therefore +1 */
 155         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
 156                 max_tx_streams =
 157                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
 158                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
 159         else
 160                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
 161
 162         /*
 163          * 802.11n-2009 20.3.5 / 20.6 says:
 164          * - indices 0 to 7 and 32 are single spatial stream
 165          * - 8 to 31 are multiple spatial streams using equal modulation
 166          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
 167          * - remainder are multiple spatial streams using unequal modulation
 168          */
 169         for (i = 0; i < max_tx_streams; i++)
 170                 ht_cap->mcs.rx_mask[i] =
 171                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
 172
 173         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
 174                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
 175                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
 176                         ht_cap->mcs.rx_mask[i] =
 177                                 sband->ht_cap.mcs.rx_mask[i] &
 178                                         ht_cap_ie->mcs.rx_mask[i];
 179
 180         /* handle MCS rate 32 too */
 181         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
 182                 ht_cap->mcs.rx_mask[32/8] |= 1;
 183
 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
 191 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, bool tx)
 192 {
 193         int i;
 194
 195         cancel_work_sync(&sta->ampdu_mlme.work);
 196
 197         for (i = 0; i <  STA_TID_NUM; i++) {
 198                 __ieee80211_stop_tx_ba_session(sta, i, WLAN_BACK_INITIATOR, tx);
 199                 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
 200                                                WLAN_REASON_QSTA_LEAVE_QBSS, tx);
 201         }
 202 }
 203
 204 void ieee80211_ba_session_work(struct work_struct *work)
 205 {
 206         struct sta_info *sta =
 207                 container_of(work, struct sta_info, ampdu_mlme.work);
 208         struct tid_ampdu_tx *tid_tx;
 209         int tid;
 210
 211         /*
 212          * When this flag is set, new sessions should be
 213          * blocked, and existing sessions will be torn
 214          * down by the code that set the flag, so this
 215          * need not run.
 216          */
 217         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
 218                 return;
 219
 220         mutex_lock(&sta->ampdu_mlme.mtx);
 221         for (tid = 0; tid < STA_TID_NUM; tid++) {
 222                 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
 223                         ___ieee80211_stop_rx_ba_session(
 224                                 sta, tid, WLAN_BACK_RECIPIENT,
 225                                 WLAN_REASON_QSTA_TIMEOUT, true);
 226
 227                 if (test_and_clear_bit(tid,
 228                                        sta->ampdu_mlme.tid_rx_stop_requested))
 229                         ___ieee80211_stop_rx_ba_session(
 230                                 sta, tid, WLAN_BACK_RECIPIENT,
 231                                 WLAN_REASON_UNSPECIFIED, true);
 232
 233                 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
 234                 if (tid_tx) {
 235                         /*
 236                          * Assign it over to the normal tid_tx array
 237                          * where it "goes live".
 238                          */
 239                         spin_lock_bh(&sta->lock);
 240
 241                         sta->ampdu_mlme.tid_start_tx[tid] = NULL;
 242                         /* could there be a race? */
 243                         if (sta->ampdu_mlme.tid_tx[tid])
 244                                 kfree(tid_tx);
 245                         else
 246                                 ieee80211_assign_tid_tx(sta, tid, tid_tx);
 247                         spin_unlock_bh(&sta->lock);
 248
 249                         ieee80211_tx_ba_session_handle_start(sta, tid);
 250                         continue;
 251                 }
 252
 253                 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
 254                 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
 255                                                  &tid_tx->state))
 256                         ___ieee80211_stop_tx_ba_session(sta, tid,
 257                                                         WLAN_BACK_INITIATOR,
 258                                                         true);
 259         }
 260         mutex_unlock(&sta->ampdu_mlme.mtx);
 261 }
 262
 263 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
 264                           const u8 *da, u16 tid,
 265                           u16 initiator, u16 reason_code)
 266 {
 267         struct ieee80211_local *local = sdata->local;
 268         struct sk_buff *skb;
 269         struct ieee80211_mgmt *mgmt;
 270         u16 params;
 271
 272         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
 273         if (!skb)
 274                 return;
 275
 276         skb_reserve(skb, local->hw.extra_tx_headroom);
 277         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
 278         memset(mgmt, 0, 24);
 279         memcpy(mgmt->da, da, ETH_ALEN);
 280         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 281         if (sdata->vif.type == NL80211_IFTYPE_AP ||
 282             sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
 283             sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 284                 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 285         else if (sdata->vif.type == NL80211_IFTYPE_STATION)
 286                 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 287         else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 288                 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
 289
 290         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 291                                           IEEE80211_STYPE_ACTION);
 292
 293         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
 294
 295         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 296         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
 297         params = (u16)(initiator << 11);        /* bit 11 initiator */
 298         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
 299
 300         mgmt->u.action.u.delba.params = cpu_to_le16(params);
 301         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
 302
 303         ieee80211_tx_skb(sdata, skb);
 304 }
 305
 306 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
 307                              struct sta_info *sta,
 308                              struct ieee80211_mgmt *mgmt, size_t len)
 309 {
 310         u16 tid, params;
 311         u16 initiator;
 312
 313         params = le16_to_cpu(mgmt->u.action.u.delba.params);
 314         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
 315         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
 316
 317 #ifdef CONFIG_MAC80211_HT_DEBUG
 318         if (net_ratelimit())
 319                 printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
 320                         mgmt->sa, initiator ? "initiator" : "recipient", tid,
 321                         le16_to_cpu(mgmt->u.action.u.delba.reason_code));
 322 #endif /* CONFIG_MAC80211_HT_DEBUG */
 323
 324         if (initiator == WLAN_BACK_INITIATOR)
 325                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
 326                                                true);
 327         else
 328                 __ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 329                                                true);
 330 }
 331
 332 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
 333                                enum ieee80211_smps_mode smps, const u8 *da,
 334                                const u8 *bssid)
 335 {
 336         struct ieee80211_local *local = sdata->local;
 337         struct sk_buff *skb;
 338         struct ieee80211_mgmt *action_frame;
 339
 340         /* 27 = header + category + action + smps mode */
 341         skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
 342         if (!skb)
 343                 return -ENOMEM;
 344
 345         skb_reserve(skb, local->hw.extra_tx_headroom);
 346         action_frame = (void *)skb_put(skb, 27);
 347         memcpy(action_frame->da, da, ETH_ALEN);
 348         memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
 349         memcpy(action_frame->bssid, bssid, ETH_ALEN);
 350         action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 351                                                   IEEE80211_STYPE_ACTION);
 352         action_frame->u.action.category = WLAN_CATEGORY_HT;
 353         action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
 354         switch (smps) {
 355         case IEEE80211_SMPS_AUTOMATIC:
 356         case IEEE80211_SMPS_NUM_MODES:
 357                 WARN_ON(1);
 358         case IEEE80211_SMPS_OFF:
 359                 action_frame->u.action.u.ht_smps.smps_control =
 360                                 WLAN_HT_SMPS_CONTROL_DISABLED;
 361                 break;
 362         case IEEE80211_SMPS_STATIC:
 363                 action_frame->u.action.u.ht_smps.smps_control =
 364                                 WLAN_HT_SMPS_CONTROL_STATIC;
 365                 break;
 366         case IEEE80211_SMPS_DYNAMIC:
 367                 action_frame->u.action.u.ht_smps.smps_control =
 368                                 WLAN_HT_SMPS_CONTROL_DYNAMIC;
 369                 break;
 370         }
 371
 372         /* we'll do more on status of this frame */
 373         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
 374         ieee80211_tx_skb(sdata, skb);
 375
 376         return 0;
 377 }
 378
 379 void ieee80211_request_smps_work(struct work_struct *work)
 380 {
 381         struct ieee80211_sub_if_data *sdata =
 382                 container_of(work, struct ieee80211_sub_if_data,
 383                              u.mgd.request_smps_work);
 384
 385         mutex_lock(&sdata->u.mgd.mtx);
 386         __ieee80211_request_smps(sdata, sdata->u.mgd.driver_smps_mode);
 387         mutex_unlock(&sdata->u.mgd.mtx);
 388 }
 389
 390 void ieee80211_request_smps(struct ieee80211_vif *vif,
 391                             enum ieee80211_smps_mode smps_mode)
 392 {
 393         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 394
 395         if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
 396                 return;
 397
 398         if (WARN_ON(smps_mode == IEEE80211_SMPS_OFF))
 399                 smps_mode = IEEE80211_SMPS_AUTOMATIC;
 400
 401         sdata->u.mgd.driver_smps_mode = smps_mode;
 402
 403         ieee80211_queue_work(&sdata->local->hw,
 404                              &sdata->u.mgd.request_smps_work);
 405 }
 406 /* this might change ... don't want non-open drivers using it */
 407 EXPORT_SYMBOL_GPL(ieee80211_request_smps);