linux/net/mac80211/ht.c
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   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
  22static 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
  33void 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
  89void 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
 182void 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 <  STA_TID_NUM; 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
 195void 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 < STA_TID_NUM; 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
 254void 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
 297void 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
 321int 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
 368void 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
 379void 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 */
 396EXPORT_SYMBOL_GPL(ieee80211_request_smps);
 397
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