linux/net/mac80211/rate.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright 2002-2005, Instant802 Networks, Inc.
   4 * Copyright 2005-2006, Devicescape Software, Inc.
   5 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
   6 * Copyright 2017       Intel Deutschland GmbH
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/rtnetlink.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
  13#include "rate.h"
  14#include "ieee80211_i.h"
  15#include "debugfs.h"
  16
  17struct rate_control_alg {
  18        struct list_head list;
  19        const struct rate_control_ops *ops;
  20};
  21
  22static LIST_HEAD(rate_ctrl_algs);
  23static DEFINE_MUTEX(rate_ctrl_mutex);
  24
  25static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  26module_param(ieee80211_default_rc_algo, charp, 0644);
  27MODULE_PARM_DESC(ieee80211_default_rc_algo,
  28                 "Default rate control algorithm for mac80211 to use");
  29
  30void rate_control_rate_init(struct sta_info *sta)
  31{
  32        struct ieee80211_local *local = sta->sdata->local;
  33        struct rate_control_ref *ref = sta->rate_ctrl;
  34        struct ieee80211_sta *ista = &sta->sta;
  35        void *priv_sta = sta->rate_ctrl_priv;
  36        struct ieee80211_supported_band *sband;
  37        struct ieee80211_chanctx_conf *chanctx_conf;
  38
  39        ieee80211_sta_set_rx_nss(sta);
  40
  41        if (!ref)
  42                return;
  43
  44        rcu_read_lock();
  45
  46        chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  47        if (WARN_ON(!chanctx_conf)) {
  48                rcu_read_unlock();
  49                return;
  50        }
  51
  52        sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  53
  54        /* TODO: check for minstrel_s1g ? */
  55        if (sband->band == NL80211_BAND_S1GHZ) {
  56                ieee80211_s1g_sta_rate_init(sta);
  57                rcu_read_unlock();
  58                return;
  59        }
  60
  61        spin_lock_bh(&sta->rate_ctrl_lock);
  62        ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  63                            priv_sta);
  64        spin_unlock_bh(&sta->rate_ctrl_lock);
  65        rcu_read_unlock();
  66        set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  67}
  68
  69void rate_control_tx_status(struct ieee80211_local *local,
  70                            struct ieee80211_supported_band *sband,
  71                            struct ieee80211_tx_status *st)
  72{
  73        struct rate_control_ref *ref = local->rate_ctrl;
  74        struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  75        void *priv_sta = sta->rate_ctrl_priv;
  76
  77        if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  78                return;
  79
  80        spin_lock_bh(&sta->rate_ctrl_lock);
  81        if (ref->ops->tx_status_ext)
  82                ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
  83        else if (st->skb)
  84                ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
  85        else
  86                WARN_ON_ONCE(1);
  87
  88        spin_unlock_bh(&sta->rate_ctrl_lock);
  89}
  90
  91void rate_control_rate_update(struct ieee80211_local *local,
  92                                    struct ieee80211_supported_band *sband,
  93                                    struct sta_info *sta, u32 changed)
  94{
  95        struct rate_control_ref *ref = local->rate_ctrl;
  96        struct ieee80211_sta *ista = &sta->sta;
  97        void *priv_sta = sta->rate_ctrl_priv;
  98        struct ieee80211_chanctx_conf *chanctx_conf;
  99
 100        if (ref && ref->ops->rate_update) {
 101                rcu_read_lock();
 102
 103                chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
 104                if (WARN_ON(!chanctx_conf)) {
 105                        rcu_read_unlock();
 106                        return;
 107                }
 108
 109                spin_lock_bh(&sta->rate_ctrl_lock);
 110                ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 111                                      ista, priv_sta, changed);
 112                spin_unlock_bh(&sta->rate_ctrl_lock);
 113                rcu_read_unlock();
 114        }
 115        drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 116}
 117
 118int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 119{
 120        struct rate_control_alg *alg;
 121
 122        if (!ops->name)
 123                return -EINVAL;
 124
 125        mutex_lock(&rate_ctrl_mutex);
 126        list_for_each_entry(alg, &rate_ctrl_algs, list) {
 127                if (!strcmp(alg->ops->name, ops->name)) {
 128                        /* don't register an algorithm twice */
 129                        WARN_ON(1);
 130                        mutex_unlock(&rate_ctrl_mutex);
 131                        return -EALREADY;
 132                }
 133        }
 134
 135        alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 136        if (alg == NULL) {
 137                mutex_unlock(&rate_ctrl_mutex);
 138                return -ENOMEM;
 139        }
 140        alg->ops = ops;
 141
 142        list_add_tail(&alg->list, &rate_ctrl_algs);
 143        mutex_unlock(&rate_ctrl_mutex);
 144
 145        return 0;
 146}
 147EXPORT_SYMBOL(ieee80211_rate_control_register);
 148
 149void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 150{
 151        struct rate_control_alg *alg;
 152
 153        mutex_lock(&rate_ctrl_mutex);
 154        list_for_each_entry(alg, &rate_ctrl_algs, list) {
 155                if (alg->ops == ops) {
 156                        list_del(&alg->list);
 157                        kfree(alg);
 158                        break;
 159                }
 160        }
 161        mutex_unlock(&rate_ctrl_mutex);
 162}
 163EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 164
 165static const struct rate_control_ops *
 166ieee80211_try_rate_control_ops_get(const char *name)
 167{
 168        struct rate_control_alg *alg;
 169        const struct rate_control_ops *ops = NULL;
 170
 171        if (!name)
 172                return NULL;
 173
 174        mutex_lock(&rate_ctrl_mutex);
 175        list_for_each_entry(alg, &rate_ctrl_algs, list) {
 176                if (!strcmp(alg->ops->name, name)) {
 177                        ops = alg->ops;
 178                        break;
 179                }
 180        }
 181        mutex_unlock(&rate_ctrl_mutex);
 182        return ops;
 183}
 184
 185/* Get the rate control algorithm. */
 186static const struct rate_control_ops *
 187ieee80211_rate_control_ops_get(const char *name)
 188{
 189        const struct rate_control_ops *ops;
 190        const char *alg_name;
 191
 192        kernel_param_lock(THIS_MODULE);
 193        if (!name)
 194                alg_name = ieee80211_default_rc_algo;
 195        else
 196                alg_name = name;
 197
 198        ops = ieee80211_try_rate_control_ops_get(alg_name);
 199        if (!ops && name)
 200                /* try default if specific alg requested but not found */
 201                ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 202
 203        /* Note: check for > 0 is intentional to avoid clang warning */
 204        if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 205                /* try built-in one if specific alg requested but not found */
 206                ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 207
 208        kernel_param_unlock(THIS_MODULE);
 209
 210        return ops;
 211}
 212
 213#ifdef CONFIG_MAC80211_DEBUGFS
 214static ssize_t rcname_read(struct file *file, char __user *userbuf,
 215                           size_t count, loff_t *ppos)
 216{
 217        struct rate_control_ref *ref = file->private_data;
 218        int len = strlen(ref->ops->name);
 219
 220        return simple_read_from_buffer(userbuf, count, ppos,
 221                                       ref->ops->name, len);
 222}
 223
 224const struct file_operations rcname_ops = {
 225        .read = rcname_read,
 226        .open = simple_open,
 227        .llseek = default_llseek,
 228};
 229#endif
 230
 231static struct rate_control_ref *
 232rate_control_alloc(const char *name, struct ieee80211_local *local)
 233{
 234        struct rate_control_ref *ref;
 235
 236        ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 237        if (!ref)
 238                return NULL;
 239        ref->ops = ieee80211_rate_control_ops_get(name);
 240        if (!ref->ops)
 241                goto free;
 242
 243        ref->priv = ref->ops->alloc(&local->hw);
 244        if (!ref->priv)
 245                goto free;
 246        return ref;
 247
 248free:
 249        kfree(ref);
 250        return NULL;
 251}
 252
 253static void rate_control_free(struct ieee80211_local *local,
 254                              struct rate_control_ref *ctrl_ref)
 255{
 256        ctrl_ref->ops->free(ctrl_ref->priv);
 257
 258#ifdef CONFIG_MAC80211_DEBUGFS
 259        debugfs_remove_recursive(local->debugfs.rcdir);
 260        local->debugfs.rcdir = NULL;
 261#endif
 262
 263        kfree(ctrl_ref);
 264}
 265
 266void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata)
 267{
 268        struct ieee80211_local *local = sdata->local;
 269        struct ieee80211_supported_band *sband;
 270        u32 user_mask, basic_rates = sdata->vif.bss_conf.basic_rates;
 271        enum nl80211_band band;
 272
 273        if (WARN_ON(!sdata->vif.bss_conf.chandef.chan))
 274                return;
 275
 276        band = sdata->vif.bss_conf.chandef.chan->band;
 277        if (band == NL80211_BAND_S1GHZ) {
 278                /* TODO */
 279                return;
 280        }
 281
 282        if (WARN_ON_ONCE(!basic_rates))
 283                return;
 284
 285        user_mask = sdata->rc_rateidx_mask[band];
 286        sband = local->hw.wiphy->bands[band];
 287
 288        if (user_mask & basic_rates)
 289                return;
 290
 291        sdata_dbg(sdata,
 292                  "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 293                  basic_rates, user_mask, band);
 294        sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 295}
 296
 297static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 298{
 299        struct sk_buff *skb = txrc->skb;
 300        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 301
 302        return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 303                               IEEE80211_TX_CTL_USE_MINRATE)) ||
 304                !ieee80211_is_tx_data(skb);
 305}
 306
 307static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 308                                  u32 basic_rates,
 309                                  struct ieee80211_supported_band *sband)
 310{
 311        u8 i;
 312
 313        if (sband->band == NL80211_BAND_S1GHZ) {
 314                /* TODO */
 315                rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 316                rate->idx = 0;
 317                return;
 318        }
 319
 320        if (basic_rates == 0)
 321                return; /* assume basic rates unknown and accept rate */
 322        if (rate->idx < 0)
 323                return;
 324        if (basic_rates & (1 << rate->idx))
 325                return; /* selected rate is a basic rate */
 326
 327        for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 328                if (basic_rates & (1 << i)) {
 329                        rate->idx = i;
 330                        return;
 331                }
 332        }
 333
 334        /* could not find a basic rate; use original selection */
 335}
 336
 337static void __rate_control_send_low(struct ieee80211_hw *hw,
 338                                    struct ieee80211_supported_band *sband,
 339                                    struct ieee80211_sta *sta,
 340                                    struct ieee80211_tx_info *info,
 341                                    u32 rate_mask)
 342{
 343        int i;
 344        u32 rate_flags =
 345                ieee80211_chandef_rate_flags(&hw->conf.chandef);
 346
 347        if (sband->band == NL80211_BAND_S1GHZ) {
 348                info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 349                info->control.rates[0].idx = 0;
 350                return;
 351        }
 352
 353        if ((sband->band == NL80211_BAND_2GHZ) &&
 354            (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 355                rate_flags |= IEEE80211_RATE_ERP_G;
 356
 357        info->control.rates[0].idx = 0;
 358        for (i = 0; i < sband->n_bitrates; i++) {
 359                if (!(rate_mask & BIT(i)))
 360                        continue;
 361
 362                if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 363                        continue;
 364
 365                if (!rate_supported(sta, sband->band, i))
 366                        continue;
 367
 368                info->control.rates[0].idx = i;
 369                break;
 370        }
 371        WARN_ONCE(i == sband->n_bitrates,
 372                  "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 373                  sta ? sta->addr : NULL,
 374                  sta ? sta->supp_rates[sband->band] : -1,
 375                  sband->band,
 376                  rate_mask, rate_flags);
 377
 378        info->control.rates[0].count =
 379                (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 380                1 : hw->max_rate_tries;
 381
 382        info->control.skip_table = 1;
 383}
 384
 385
 386static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 387                                  struct ieee80211_tx_rate_control *txrc)
 388{
 389        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 390        struct ieee80211_supported_band *sband = txrc->sband;
 391        struct sta_info *sta;
 392        int mcast_rate;
 393        bool use_basicrate = false;
 394
 395        if (ieee80211_is_tx_data(txrc->skb) &&
 396            info->flags & IEEE80211_TX_CTL_NO_ACK)
 397                return false;
 398
 399        if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 400                __rate_control_send_low(txrc->hw, sband, pubsta, info,
 401                                        txrc->rate_idx_mask);
 402
 403                if (!pubsta && txrc->bss) {
 404                        mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 405                        if (mcast_rate > 0) {
 406                                info->control.rates[0].idx = mcast_rate - 1;
 407                                return true;
 408                        }
 409                        use_basicrate = true;
 410                } else if (pubsta) {
 411                        sta = container_of(pubsta, struct sta_info, sta);
 412                        if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 413                                use_basicrate = true;
 414                }
 415
 416                if (use_basicrate)
 417                        rc_send_low_basicrate(&info->control.rates[0],
 418                                              txrc->bss_conf->basic_rates,
 419                                              sband);
 420
 421                return true;
 422        }
 423        return false;
 424}
 425
 426static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 427{
 428        int j;
 429
 430        /* See whether the selected rate or anything below it is allowed. */
 431        for (j = *rate_idx; j >= 0; j--) {
 432                if (mask & (1 << j)) {
 433                        /* Okay, found a suitable rate. Use it. */
 434                        *rate_idx = j;
 435                        return true;
 436                }
 437        }
 438
 439        /* Try to find a higher rate that would be allowed */
 440        for (j = *rate_idx + 1; j < n_bitrates; j++) {
 441                if (mask & (1 << j)) {
 442                        /* Okay, found a suitable rate. Use it. */
 443                        *rate_idx = j;
 444                        return true;
 445                }
 446        }
 447        return false;
 448}
 449
 450static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 451{
 452        int i, j;
 453        int ridx, rbit;
 454
 455        ridx = *rate_idx / 8;
 456        rbit = *rate_idx % 8;
 457
 458        /* sanity check */
 459        if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 460                return false;
 461
 462        /* See whether the selected rate or anything below it is allowed. */
 463        for (i = ridx; i >= 0; i--) {
 464                for (j = rbit; j >= 0; j--)
 465                        if (mcs_mask[i] & BIT(j)) {
 466                                *rate_idx = i * 8 + j;
 467                                return true;
 468                        }
 469                rbit = 7;
 470        }
 471
 472        /* Try to find a higher rate that would be allowed */
 473        ridx = (*rate_idx + 1) / 8;
 474        rbit = (*rate_idx + 1) % 8;
 475
 476        for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 477                for (j = rbit; j < 8; j++)
 478                        if (mcs_mask[i] & BIT(j)) {
 479                                *rate_idx = i * 8 + j;
 480                                return true;
 481                        }
 482                rbit = 0;
 483        }
 484        return false;
 485}
 486
 487static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 488{
 489        int i, j;
 490        int ridx, rbit;
 491
 492        ridx = *rate_idx >> 4;
 493        rbit = *rate_idx & 0xf;
 494
 495        if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 496                return false;
 497
 498        /* See whether the selected rate or anything below it is allowed. */
 499        for (i = ridx; i >= 0; i--) {
 500                for (j = rbit; j >= 0; j--) {
 501                        if (vht_mask[i] & BIT(j)) {
 502                                *rate_idx = (i << 4) | j;
 503                                return true;
 504                        }
 505                }
 506                rbit = 15;
 507        }
 508
 509        /* Try to find a higher rate that would be allowed */
 510        ridx = (*rate_idx + 1) >> 4;
 511        rbit = (*rate_idx + 1) & 0xf;
 512
 513        for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 514                for (j = rbit; j < 16; j++) {
 515                        if (vht_mask[i] & BIT(j)) {
 516                                *rate_idx = (i << 4) | j;
 517                                return true;
 518                        }
 519                }
 520                rbit = 0;
 521        }
 522        return false;
 523}
 524
 525static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 526                                struct ieee80211_supported_band *sband,
 527                                enum nl80211_chan_width chan_width,
 528                                u32 mask,
 529                                u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 530                                u16 vht_mask[NL80211_VHT_NSS_MAX])
 531{
 532        if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 533                /* handle VHT rates */
 534                if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 535                        return;
 536
 537                *rate_idx = 0;
 538                /* keep protection flags */
 539                *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 540                                IEEE80211_TX_RC_USE_CTS_PROTECT |
 541                                IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 542
 543                *rate_flags |= IEEE80211_TX_RC_MCS;
 544                if (chan_width == NL80211_CHAN_WIDTH_40)
 545                        *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 546
 547                if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 548                        return;
 549
 550                /* also try the legacy rates. */
 551                *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 552                                 IEEE80211_TX_RC_40_MHZ_WIDTH);
 553                if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 554                                               mask))
 555                        return;
 556        } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 557                /* handle HT rates */
 558                if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 559                        return;
 560
 561                /* also try the legacy rates. */
 562                *rate_idx = 0;
 563                /* keep protection flags */
 564                *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 565                                IEEE80211_TX_RC_USE_CTS_PROTECT |
 566                                IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 567                if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 568                                               mask))
 569                        return;
 570        } else {
 571                /* handle legacy rates */
 572                if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 573                                               mask))
 574                        return;
 575
 576                /* if HT BSS, and we handle a data frame, also try HT rates */
 577                switch (chan_width) {
 578                case NL80211_CHAN_WIDTH_20_NOHT:
 579                case NL80211_CHAN_WIDTH_5:
 580                case NL80211_CHAN_WIDTH_10:
 581                        return;
 582                default:
 583                        break;
 584                }
 585
 586                *rate_idx = 0;
 587                /* keep protection flags */
 588                *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 589                                IEEE80211_TX_RC_USE_CTS_PROTECT |
 590                                IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 591
 592                *rate_flags |= IEEE80211_TX_RC_MCS;
 593
 594                if (chan_width == NL80211_CHAN_WIDTH_40)
 595                        *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 596
 597                if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 598                        return;
 599        }
 600
 601        /*
 602         * Uh.. No suitable rate exists. This should not really happen with
 603         * sane TX rate mask configurations. However, should someone manage to
 604         * configure supported rates and TX rate mask in incompatible way,
 605         * allow the frame to be transmitted with whatever the rate control
 606         * selected.
 607         */
 608}
 609
 610static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 611                                struct ieee80211_supported_band *sband,
 612                                struct ieee80211_tx_info *info,
 613                                struct ieee80211_tx_rate *rates,
 614                                int max_rates)
 615{
 616        struct ieee80211_rate *rate;
 617        bool inval = false;
 618        int i;
 619
 620        /*
 621         * Set up the RTS/CTS rate as the fastest basic rate
 622         * that is not faster than the data rate unless there
 623         * is no basic rate slower than the data rate, in which
 624         * case we pick the slowest basic rate
 625         *
 626         * XXX: Should this check all retry rates?
 627         */
 628        if (!(rates[0].flags &
 629              (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 630                u32 basic_rates = vif->bss_conf.basic_rates;
 631                s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 632
 633                rate = &sband->bitrates[rates[0].idx];
 634
 635                for (i = 0; i < sband->n_bitrates; i++) {
 636                        /* must be a basic rate */
 637                        if (!(basic_rates & BIT(i)))
 638                                continue;
 639                        /* must not be faster than the data rate */
 640                        if (sband->bitrates[i].bitrate > rate->bitrate)
 641                                continue;
 642                        /* maximum */
 643                        if (sband->bitrates[baserate].bitrate <
 644                             sband->bitrates[i].bitrate)
 645                                baserate = i;
 646                }
 647
 648                info->control.rts_cts_rate_idx = baserate;
 649        }
 650
 651        for (i = 0; i < max_rates; i++) {
 652                /*
 653                 * make sure there's no valid rate following
 654                 * an invalid one, just in case drivers don't
 655                 * take the API seriously to stop at -1.
 656                 */
 657                if (inval) {
 658                        rates[i].idx = -1;
 659                        continue;
 660                }
 661                if (rates[i].idx < 0) {
 662                        inval = true;
 663                        continue;
 664                }
 665
 666                /*
 667                 * For now assume MCS is already set up correctly, this
 668                 * needs to be fixed.
 669                 */
 670                if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 671                        WARN_ON(rates[i].idx > 76);
 672
 673                        if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 674                            info->control.use_cts_prot)
 675                                rates[i].flags |=
 676                                        IEEE80211_TX_RC_USE_CTS_PROTECT;
 677                        continue;
 678                }
 679
 680                if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 681                        WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 682                        continue;
 683                }
 684
 685                /* set up RTS protection if desired */
 686                if (info->control.use_rts) {
 687                        rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 688                        info->control.use_cts_prot = false;
 689                }
 690
 691                /* RC is busted */
 692                if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 693                        rates[i].idx = -1;
 694                        continue;
 695                }
 696
 697                rate = &sband->bitrates[rates[i].idx];
 698
 699                /* set up short preamble */
 700                if (info->control.short_preamble &&
 701                    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 702                        rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 703
 704                /* set up G protection */
 705                if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 706                    info->control.use_cts_prot &&
 707                    rate->flags & IEEE80211_RATE_ERP_G)
 708                        rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 709        }
 710}
 711
 712
 713static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 714                                        struct ieee80211_tx_info *info,
 715                                        struct ieee80211_tx_rate *rates,
 716                                        int max_rates)
 717{
 718        struct ieee80211_sta_rates *ratetbl = NULL;
 719        int i;
 720
 721        if (sta && !info->control.skip_table)
 722                ratetbl = rcu_dereference(sta->rates);
 723
 724        /* Fill remaining rate slots with data from the sta rate table. */
 725        max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 726        for (i = 0; i < max_rates; i++) {
 727                if (i < ARRAY_SIZE(info->control.rates) &&
 728                    info->control.rates[i].idx >= 0 &&
 729                    info->control.rates[i].count) {
 730                        if (rates != info->control.rates)
 731                                rates[i] = info->control.rates[i];
 732                } else if (ratetbl) {
 733                        rates[i].idx = ratetbl->rate[i].idx;
 734                        rates[i].flags = ratetbl->rate[i].flags;
 735                        if (info->control.use_rts)
 736                                rates[i].count = ratetbl->rate[i].count_rts;
 737                        else if (info->control.use_cts_prot)
 738                                rates[i].count = ratetbl->rate[i].count_cts;
 739                        else
 740                                rates[i].count = ratetbl->rate[i].count;
 741                } else {
 742                        rates[i].idx = -1;
 743                        rates[i].count = 0;
 744                }
 745
 746                if (rates[i].idx < 0 || !rates[i].count)
 747                        break;
 748        }
 749}
 750
 751static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 752                                  struct ieee80211_supported_band *sband,
 753                                  struct ieee80211_sta *sta, u32 *mask,
 754                                  u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 755                                  u16 vht_mask[NL80211_VHT_NSS_MAX])
 756{
 757        u32 i, flags;
 758
 759        *mask = sdata->rc_rateidx_mask[sband->band];
 760        flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 761        for (i = 0; i < sband->n_bitrates; i++) {
 762                if ((flags & sband->bitrates[i].flags) != flags)
 763                        *mask &= ~BIT(i);
 764        }
 765
 766        if (*mask == (1 << sband->n_bitrates) - 1 &&
 767            !sdata->rc_has_mcs_mask[sband->band] &&
 768            !sdata->rc_has_vht_mcs_mask[sband->band])
 769                return false;
 770
 771        if (sdata->rc_has_mcs_mask[sband->band])
 772                memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 773                       IEEE80211_HT_MCS_MASK_LEN);
 774        else
 775                memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 776
 777        if (sdata->rc_has_vht_mcs_mask[sband->band])
 778                memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 779                       sizeof(u16) * NL80211_VHT_NSS_MAX);
 780        else
 781                memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 782
 783        if (sta) {
 784                __le16 sta_vht_cap;
 785                u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 786
 787                /* Filter out rates that the STA does not support */
 788                *mask &= sta->supp_rates[sband->band];
 789                for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 790                        mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 791
 792                sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
 793                ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 794                for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 795                        vht_mask[i] &= sta_vht_mask[i];
 796        }
 797
 798        return true;
 799}
 800
 801static void
 802rate_control_apply_mask_ratetbl(struct sta_info *sta,
 803                                struct ieee80211_supported_band *sband,
 804                                struct ieee80211_sta_rates *rates)
 805{
 806        int i;
 807        u32 mask;
 808        u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 809        u16 vht_mask[NL80211_VHT_NSS_MAX];
 810        enum nl80211_chan_width chan_width;
 811
 812        if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 813                                   mcs_mask, vht_mask))
 814                return;
 815
 816        chan_width = sta->sdata->vif.bss_conf.chandef.width;
 817        for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 818                if (rates->rate[i].idx < 0)
 819                        break;
 820
 821                rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 822                                    sband, chan_width, mask, mcs_mask,
 823                                    vht_mask);
 824        }
 825}
 826
 827static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 828                                    struct ieee80211_sta *sta,
 829                                    struct ieee80211_supported_band *sband,
 830                                    struct ieee80211_tx_rate *rates,
 831                                    int max_rates)
 832{
 833        enum nl80211_chan_width chan_width;
 834        u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 835        u32 mask;
 836        u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 837        int i;
 838
 839        /*
 840         * Try to enforce the rateidx mask the user wanted. skip this if the
 841         * default mask (allow all rates) is used to save some processing for
 842         * the common case.
 843         */
 844        if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 845                                   vht_mask))
 846                return;
 847
 848        /*
 849         * Make sure the rate index selected for each TX rate is
 850         * included in the configured mask and change the rate indexes
 851         * if needed.
 852         */
 853        chan_width = sdata->vif.bss_conf.chandef.width;
 854        for (i = 0; i < max_rates; i++) {
 855                /* Skip invalid rates */
 856                if (rates[i].idx < 0)
 857                        break;
 858
 859                rate_flags = rates[i].flags;
 860                rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 861                                    chan_width, mask, mcs_mask, vht_mask);
 862                rates[i].flags = rate_flags;
 863        }
 864}
 865
 866void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 867                            struct ieee80211_sta *sta,
 868                            struct sk_buff *skb,
 869                            struct ieee80211_tx_rate *dest,
 870                            int max_rates)
 871{
 872        struct ieee80211_sub_if_data *sdata;
 873        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 874        struct ieee80211_supported_band *sband;
 875
 876        rate_control_fill_sta_table(sta, info, dest, max_rates);
 877
 878        if (!vif)
 879                return;
 880
 881        sdata = vif_to_sdata(vif);
 882        sband = sdata->local->hw.wiphy->bands[info->band];
 883
 884        if (ieee80211_is_tx_data(skb))
 885                rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 886
 887        if (dest[0].idx < 0)
 888                __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 889                                        sdata->rc_rateidx_mask[info->band]);
 890
 891        if (sta)
 892                rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 893}
 894EXPORT_SYMBOL(ieee80211_get_tx_rates);
 895
 896void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 897                           struct sta_info *sta,
 898                           struct ieee80211_tx_rate_control *txrc)
 899{
 900        struct rate_control_ref *ref = sdata->local->rate_ctrl;
 901        void *priv_sta = NULL;
 902        struct ieee80211_sta *ista = NULL;
 903        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 904        int i;
 905
 906        for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 907                info->control.rates[i].idx = -1;
 908                info->control.rates[i].flags = 0;
 909                info->control.rates[i].count = 0;
 910        }
 911
 912        if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 913                return;
 914
 915        if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 916                return;
 917
 918        if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 919                ista = &sta->sta;
 920                priv_sta = sta->rate_ctrl_priv;
 921        }
 922
 923        if (ista) {
 924                spin_lock_bh(&sta->rate_ctrl_lock);
 925                ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 926                spin_unlock_bh(&sta->rate_ctrl_lock);
 927        } else {
 928                rate_control_send_low(NULL, txrc);
 929        }
 930
 931        if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 932                return;
 933
 934        ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 935                               info->control.rates,
 936                               ARRAY_SIZE(info->control.rates));
 937}
 938
 939int rate_control_set_rates(struct ieee80211_hw *hw,
 940                           struct ieee80211_sta *pubsta,
 941                           struct ieee80211_sta_rates *rates)
 942{
 943        struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 944        struct ieee80211_sta_rates *old;
 945        struct ieee80211_supported_band *sband;
 946
 947        sband = ieee80211_get_sband(sta->sdata);
 948        if (!sband)
 949                return -EINVAL;
 950        rate_control_apply_mask_ratetbl(sta, sband, rates);
 951        /*
 952         * mac80211 guarantees that this function will not be called
 953         * concurrently, so the following RCU access is safe, even without
 954         * extra locking. This can not be checked easily, so we just set
 955         * the condition to true.
 956         */
 957        old = rcu_dereference_protected(pubsta->rates, true);
 958        rcu_assign_pointer(pubsta->rates, rates);
 959        if (old)
 960                kfree_rcu(old, rcu_head);
 961
 962        if (sta->uploaded)
 963                drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 964
 965        ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
 966
 967        return 0;
 968}
 969EXPORT_SYMBOL(rate_control_set_rates);
 970
 971int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 972                                 const char *name)
 973{
 974        struct rate_control_ref *ref;
 975
 976        ASSERT_RTNL();
 977
 978        if (local->open_count)
 979                return -EBUSY;
 980
 981        if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 982                if (WARN_ON(!local->ops->set_rts_threshold))
 983                        return -EINVAL;
 984                return 0;
 985        }
 986
 987        ref = rate_control_alloc(name, local);
 988        if (!ref) {
 989                wiphy_warn(local->hw.wiphy,
 990                           "Failed to select rate control algorithm\n");
 991                return -ENOENT;
 992        }
 993
 994        WARN_ON(local->rate_ctrl);
 995        local->rate_ctrl = ref;
 996
 997        wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 998                    ref->ops->name);
 999
1000        return 0;
1001}
1002
1003void rate_control_deinitialize(struct ieee80211_local *local)
1004{
1005        struct rate_control_ref *ref;
1006
1007        ref = local->rate_ctrl;
1008
1009        if (!ref)
1010                return;
1011
1012        local->rate_ctrl = NULL;
1013        rate_control_free(local, ref);
1014}
1015