net/mac80211/rate.c

   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  * Copyright (C) 2022 Intel Corporation
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include "rate.h"
  15 #include "ieee80211_i.h"
  16 #include "debugfs.h"
  17
  18 struct rate_control_alg {
  19         struct list_head list;
  20         const struct rate_control_ops *ops;
  21 };
  22
  23 static LIST_HEAD(rate_ctrl_algs);
  24 static DEFINE_MUTEX(rate_ctrl_mutex);
  25
  26 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  27 module_param(ieee80211_default_rc_algo, charp, 0644);
  28 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  29                  "Default rate control algorithm for mac80211 to use");
  30
  31 void rate_control_rate_init(struct sta_info *sta)
  32 {
  33         struct ieee80211_local *local = sta->sdata->local;
  34         struct rate_control_ref *ref = sta->rate_ctrl;
  35         struct ieee80211_sta *ista = &sta->sta;
  36         void *priv_sta = sta->rate_ctrl_priv;
  37         struct ieee80211_supported_band *sband;
  38         struct ieee80211_chanctx_conf *chanctx_conf;
  39
  40         ieee80211_sta_set_rx_nss(sta);
  41
  42         if (!ref)
  43                 return;
  44
  45         rcu_read_lock();
  46
  47         chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
  48         if (WARN_ON(!chanctx_conf)) {
  49                 rcu_read_unlock();
  50                 return;
  51         }
  52
  53         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  54
  55         /* TODO: check for minstrel_s1g ? */
  56         if (sband->band == NL80211_BAND_S1GHZ) {
  57                 ieee80211_s1g_sta_rate_init(sta);
  58                 rcu_read_unlock();
  59                 return;
  60         }
  61
  62         spin_lock_bh(&sta->rate_ctrl_lock);
  63         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  64                             priv_sta);
  65         spin_unlock_bh(&sta->rate_ctrl_lock);
  66         rcu_read_unlock();
  67         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  68 }
  69
  70 void rate_control_tx_status(struct ieee80211_local *local,
  71                             struct ieee80211_supported_band *sband,
  72                             struct ieee80211_tx_status *st)
  73 {
  74         struct rate_control_ref *ref = local->rate_ctrl;
  75         struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  76         void *priv_sta = sta->rate_ctrl_priv;
  77
  78         if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  79                 return;
  80
  81         spin_lock_bh(&sta->rate_ctrl_lock);
  82         if (ref->ops->tx_status_ext)
  83                 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
  84         else if (st->skb)
  85                 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
  86         else
  87                 WARN_ON_ONCE(1);
  88
  89         spin_unlock_bh(&sta->rate_ctrl_lock);
  90 }
  91
  92 void rate_control_rate_update(struct ieee80211_local *local,
  93                                     struct ieee80211_supported_band *sband,
  94                                     struct sta_info *sta, u32 changed)
  95 {
  96         struct rate_control_ref *ref = local->rate_ctrl;
  97         struct ieee80211_sta *ista = &sta->sta;
  98         void *priv_sta = sta->rate_ctrl_priv;
  99         struct ieee80211_chanctx_conf *chanctx_conf;
 100
 101         if (ref && ref->ops->rate_update) {
 102                 rcu_read_lock();
 103
 104                 chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
 105                 if (WARN_ON(!chanctx_conf)) {
 106                         rcu_read_unlock();
 107                         return;
 108                 }
 109
 110                 spin_lock_bh(&sta->rate_ctrl_lock);
 111                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 112                                       ista, priv_sta, changed);
 113                 spin_unlock_bh(&sta->rate_ctrl_lock);
 114                 rcu_read_unlock();
 115         }
 116         drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 117 }
 118
 119 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 120 {
 121         struct rate_control_alg *alg;
 122
 123         if (!ops->name)
 124                 return -EINVAL;
 125
 126         mutex_lock(&rate_ctrl_mutex);
 127         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 128                 if (!strcmp(alg->ops->name, ops->name)) {
 129                         /* don't register an algorithm twice */
 130                         WARN_ON(1);
 131                         mutex_unlock(&rate_ctrl_mutex);
 132                         return -EALREADY;
 133                 }
 134         }
 135
 136         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 137         if (alg == NULL) {
 138                 mutex_unlock(&rate_ctrl_mutex);
 139                 return -ENOMEM;
 140         }
 141         alg->ops = ops;
 142
 143         list_add_tail(&alg->list, &rate_ctrl_algs);
 144         mutex_unlock(&rate_ctrl_mutex);
 145
 146         return 0;
 147 }
 148 EXPORT_SYMBOL(ieee80211_rate_control_register);
 149
 150 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 151 {
 152         struct rate_control_alg *alg;
 153
 154         mutex_lock(&rate_ctrl_mutex);
 155         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 156                 if (alg->ops == ops) {
 157                         list_del(&alg->list);
 158                         kfree(alg);
 159                         break;
 160                 }
 161         }
 162         mutex_unlock(&rate_ctrl_mutex);
 163 }
 164 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 165
 166 static const struct rate_control_ops *
 167 ieee80211_try_rate_control_ops_get(const char *name)
 168 {
 169         struct rate_control_alg *alg;
 170         const struct rate_control_ops *ops = NULL;
 171
 172         if (!name)
 173                 return NULL;
 174
 175         mutex_lock(&rate_ctrl_mutex);
 176         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 177                 if (!strcmp(alg->ops->name, name)) {
 178                         ops = alg->ops;
 179                         break;
 180                 }
 181         }
 182         mutex_unlock(&rate_ctrl_mutex);
 183         return ops;
 184 }
 185
 186 /* Get the rate control algorithm. */
 187 static const struct rate_control_ops *
 188 ieee80211_rate_control_ops_get(const char *name)
 189 {
 190         const struct rate_control_ops *ops;
 191         const char *alg_name;
 192
 193         kernel_param_lock(THIS_MODULE);
 194         if (!name)
 195                 alg_name = ieee80211_default_rc_algo;
 196         else
 197                 alg_name = name;
 198
 199         ops = ieee80211_try_rate_control_ops_get(alg_name);
 200         if (!ops && name)
 201                 /* try default if specific alg requested but not found */
 202                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 203
 204         /* Note: check for > 0 is intentional to avoid clang warning */
 205         if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 206                 /* try built-in one if specific alg requested but not found */
 207                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 208
 209         kernel_param_unlock(THIS_MODULE);
 210
 211         return ops;
 212 }
 213
 214 #ifdef CONFIG_MAC80211_DEBUGFS
 215 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 216                            size_t count, loff_t *ppos)
 217 {
 218         struct rate_control_ref *ref = file->private_data;
 219         int len = strlen(ref->ops->name);
 220
 221         return simple_read_from_buffer(userbuf, count, ppos,
 222                                        ref->ops->name, len);
 223 }
 224
 225 const struct file_operations rcname_ops = {
 226         .read = rcname_read,
 227         .open = simple_open,
 228         .llseek = default_llseek,
 229 };
 230 #endif
 231
 232 static struct rate_control_ref *
 233 rate_control_alloc(const char *name, struct ieee80211_local *local)
 234 {
 235         struct rate_control_ref *ref;
 236
 237         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 238         if (!ref)
 239                 return NULL;
 240         ref->ops = ieee80211_rate_control_ops_get(name);
 241         if (!ref->ops)
 242                 goto free;
 243
 244         ref->priv = ref->ops->alloc(&local->hw);
 245         if (!ref->priv)
 246                 goto free;
 247         return ref;
 248
 249 free:
 250         kfree(ref);
 251         return NULL;
 252 }
 253
 254 static void rate_control_free(struct ieee80211_local *local,
 255                               struct rate_control_ref *ctrl_ref)
 256 {
 257         ctrl_ref->ops->free(ctrl_ref->priv);
 258
 259 #ifdef CONFIG_MAC80211_DEBUGFS
 260         debugfs_remove_recursive(local->debugfs.rcdir);
 261         local->debugfs.rcdir = NULL;
 262 #endif
 263
 264         kfree(ctrl_ref);
 265 }
 266
 267 void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata)
 268 {
 269         struct ieee80211_local *local = sdata->local;
 270         struct ieee80211_supported_band *sband;
 271         u32 user_mask, basic_rates = sdata->vif.bss_conf.basic_rates;
 272         enum nl80211_band band;
 273
 274         if (WARN_ON(!sdata->vif.bss_conf.chandef.chan))
 275                 return;
 276
 277         band = sdata->vif.bss_conf.chandef.chan->band;
 278         if (band == NL80211_BAND_S1GHZ) {
 279                 /* TODO */
 280                 return;
 281         }
 282
 283         if (WARN_ON_ONCE(!basic_rates))
 284                 return;
 285
 286         user_mask = sdata->rc_rateidx_mask[band];
 287         sband = local->hw.wiphy->bands[band];
 288
 289         if (user_mask & basic_rates)
 290                 return;
 291
 292         sdata_dbg(sdata,
 293                   "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 294                   basic_rates, user_mask, band);
 295         sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 296 }
 297
 298 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 299 {
 300         struct sk_buff *skb = txrc->skb;
 301         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 302
 303         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 304                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 305                 !ieee80211_is_tx_data(skb);
 306 }
 307
 308 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 309                                   u32 basic_rates,
 310                                   struct ieee80211_supported_band *sband)
 311 {
 312         u8 i;
 313
 314         if (sband->band == NL80211_BAND_S1GHZ) {
 315                 /* TODO */
 316                 rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 317                 rate->idx = 0;
 318                 return;
 319         }
 320
 321         if (basic_rates == 0)
 322                 return; /* assume basic rates unknown and accept rate */
 323         if (rate->idx < 0)
 324                 return;
 325         if (basic_rates & (1 << rate->idx))
 326                 return; /* selected rate is a basic rate */
 327
 328         for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 329                 if (basic_rates & (1 << i)) {
 330                         rate->idx = i;
 331                         return;
 332                 }
 333         }
 334
 335         /* could not find a basic rate; use original selection */
 336 }
 337
 338 static void __rate_control_send_low(struct ieee80211_hw *hw,
 339                                     struct ieee80211_supported_band *sband,
 340                                     struct ieee80211_sta *sta,
 341                                     struct ieee80211_tx_info *info,
 342                                     u32 rate_mask)
 343 {
 344         int i;
 345         u32 rate_flags =
 346                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 347
 348         if (sband->band == NL80211_BAND_S1GHZ) {
 349                 info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 350                 info->control.rates[0].idx = 0;
 351                 return;
 352         }
 353
 354         if ((sband->band == NL80211_BAND_2GHZ) &&
 355             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 356                 rate_flags |= IEEE80211_RATE_ERP_G;
 357
 358         info->control.rates[0].idx = 0;
 359         for (i = 0; i < sband->n_bitrates; i++) {
 360                 if (!(rate_mask & BIT(i)))
 361                         continue;
 362
 363                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 364                         continue;
 365
 366                 if (!rate_supported(sta, sband->band, i))
 367                         continue;
 368
 369                 info->control.rates[0].idx = i;
 370                 break;
 371         }
 372         WARN_ONCE(i == sband->n_bitrates,
 373                   "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 374                   sta ? sta->addr : NULL,
 375                   sta ? sta->deflink.supp_rates[sband->band] : -1,
 376                   sband->band,
 377                   rate_mask, rate_flags);
 378
 379         info->control.rates[0].count =
 380                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 381                 1 : hw->max_rate_tries;
 382
 383         info->control.skip_table = 1;
 384 }
 385
 386
 387 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 388                                   struct ieee80211_tx_rate_control *txrc)
 389 {
 390         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 391         struct ieee80211_supported_band *sband = txrc->sband;
 392         struct sta_info *sta;
 393         int mcast_rate;
 394         bool use_basicrate = false;
 395
 396         if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 397                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 398                                         txrc->rate_idx_mask);
 399
 400                 if (!pubsta && txrc->bss) {
 401                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 402                         if (mcast_rate > 0) {
 403                                 info->control.rates[0].idx = mcast_rate - 1;
 404                                 return true;
 405                         }
 406                         use_basicrate = true;
 407                 } else if (pubsta) {
 408                         sta = container_of(pubsta, struct sta_info, sta);
 409                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 410                                 use_basicrate = true;
 411                 }
 412
 413                 if (use_basicrate)
 414                         rc_send_low_basicrate(&info->control.rates[0],
 415                                               txrc->bss_conf->basic_rates,
 416                                               sband);
 417
 418                 return true;
 419         }
 420         return false;
 421 }
 422
 423 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 424 {
 425         int j;
 426
 427         /* See whether the selected rate or anything below it is allowed. */
 428         for (j = *rate_idx; j >= 0; j--) {
 429                 if (mask & (1 << j)) {
 430                         /* Okay, found a suitable rate. Use it. */
 431                         *rate_idx = j;
 432                         return true;
 433                 }
 434         }
 435
 436         /* Try to find a higher rate that would be allowed */
 437         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 438                 if (mask & (1 << j)) {
 439                         /* Okay, found a suitable rate. Use it. */
 440                         *rate_idx = j;
 441                         return true;
 442                 }
 443         }
 444         return false;
 445 }
 446
 447 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 448 {
 449         int i, j;
 450         int ridx, rbit;
 451
 452         ridx = *rate_idx / 8;
 453         rbit = *rate_idx % 8;
 454
 455         /* sanity check */
 456         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 457                 return false;
 458
 459         /* See whether the selected rate or anything below it is allowed. */
 460         for (i = ridx; i >= 0; i--) {
 461                 for (j = rbit; j >= 0; j--)
 462                         if (mcs_mask[i] & BIT(j)) {
 463                                 *rate_idx = i * 8 + j;
 464                                 return true;
 465                         }
 466                 rbit = 7;
 467         }
 468
 469         /* Try to find a higher rate that would be allowed */
 470         ridx = (*rate_idx + 1) / 8;
 471         rbit = (*rate_idx + 1) % 8;
 472
 473         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 474                 for (j = rbit; j < 8; j++)
 475                         if (mcs_mask[i] & BIT(j)) {
 476                                 *rate_idx = i * 8 + j;
 477                                 return true;
 478                         }
 479                 rbit = 0;
 480         }
 481         return false;
 482 }
 483
 484 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 485 {
 486         int i, j;
 487         int ridx, rbit;
 488
 489         ridx = *rate_idx >> 4;
 490         rbit = *rate_idx & 0xf;
 491
 492         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 493                 return false;
 494
 495         /* See whether the selected rate or anything below it is allowed. */
 496         for (i = ridx; i >= 0; i--) {
 497                 for (j = rbit; j >= 0; j--) {
 498                         if (vht_mask[i] & BIT(j)) {
 499                                 *rate_idx = (i << 4) | j;
 500                                 return true;
 501                         }
 502                 }
 503                 rbit = 15;
 504         }
 505
 506         /* Try to find a higher rate that would be allowed */
 507         ridx = (*rate_idx + 1) >> 4;
 508         rbit = (*rate_idx + 1) & 0xf;
 509
 510         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 511                 for (j = rbit; j < 16; j++) {
 512                         if (vht_mask[i] & BIT(j)) {
 513                                 *rate_idx = (i << 4) | j;
 514                                 return true;
 515                         }
 516                 }
 517                 rbit = 0;
 518         }
 519         return false;
 520 }
 521
 522 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 523                                 struct ieee80211_supported_band *sband,
 524                                 enum nl80211_chan_width chan_width,
 525                                 u32 mask,
 526                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 527                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 528 {
 529         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 530                 /* handle VHT rates */
 531                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 532                         return;
 533
 534                 *rate_idx = 0;
 535                 /* keep protection flags */
 536                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 537                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 538                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 539
 540                 *rate_flags |= IEEE80211_TX_RC_MCS;
 541                 if (chan_width == NL80211_CHAN_WIDTH_40)
 542                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 543
 544                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 545                         return;
 546
 547                 /* also try the legacy rates. */
 548                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 549                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 550                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 551                                                mask))
 552                         return;
 553         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 554                 /* handle HT rates */
 555                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 556                         return;
 557
 558                 /* also try the legacy rates. */
 559                 *rate_idx = 0;
 560                 /* keep protection flags */
 561                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 562                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 563                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 564                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 565                                                mask))
 566                         return;
 567         } else {
 568                 /* handle legacy rates */
 569                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 570                                                mask))
 571                         return;
 572
 573                 /* if HT BSS, and we handle a data frame, also try HT rates */
 574                 switch (chan_width) {
 575                 case NL80211_CHAN_WIDTH_20_NOHT:
 576                 case NL80211_CHAN_WIDTH_5:
 577                 case NL80211_CHAN_WIDTH_10:
 578                         return;
 579                 default:
 580                         break;
 581                 }
 582
 583                 *rate_idx = 0;
 584                 /* keep protection flags */
 585                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 586                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 587                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 588
 589                 *rate_flags |= IEEE80211_TX_RC_MCS;
 590
 591                 if (chan_width == NL80211_CHAN_WIDTH_40)
 592                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 593
 594                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 595                         return;
 596         }
 597
 598         /*
 599          * Uh.. No suitable rate exists. This should not really happen with
 600          * sane TX rate mask configurations. However, should someone manage to
 601          * configure supported rates and TX rate mask in incompatible way,
 602          * allow the frame to be transmitted with whatever the rate control
 603          * selected.
 604          */
 605 }
 606
 607 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 608                                 struct ieee80211_supported_band *sband,
 609                                 struct ieee80211_tx_info *info,
 610                                 struct ieee80211_tx_rate *rates,
 611                                 int max_rates)
 612 {
 613         struct ieee80211_rate *rate;
 614         bool inval = false;
 615         int i;
 616
 617         /*
 618          * Set up the RTS/CTS rate as the fastest basic rate
 619          * that is not faster than the data rate unless there
 620          * is no basic rate slower than the data rate, in which
 621          * case we pick the slowest basic rate
 622          *
 623          * XXX: Should this check all retry rates?
 624          */
 625         if (!(rates[0].flags &
 626               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 627                 u32 basic_rates = vif->bss_conf.basic_rates;
 628                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 629
 630                 rate = &sband->bitrates[rates[0].idx];
 631
 632                 for (i = 0; i < sband->n_bitrates; i++) {
 633                         /* must be a basic rate */
 634                         if (!(basic_rates & BIT(i)))
 635                                 continue;
 636                         /* must not be faster than the data rate */
 637                         if (sband->bitrates[i].bitrate > rate->bitrate)
 638                                 continue;
 639                         /* maximum */
 640                         if (sband->bitrates[baserate].bitrate <
 641                              sband->bitrates[i].bitrate)
 642                                 baserate = i;
 643                 }
 644
 645                 info->control.rts_cts_rate_idx = baserate;
 646         }
 647
 648         for (i = 0; i < max_rates; i++) {
 649                 /*
 650                  * make sure there's no valid rate following
 651                  * an invalid one, just in case drivers don't
 652                  * take the API seriously to stop at -1.
 653                  */
 654                 if (inval) {
 655                         rates[i].idx = -1;
 656                         continue;
 657                 }
 658                 if (rates[i].idx < 0) {
 659                         inval = true;
 660                         continue;
 661                 }
 662
 663                 /*
 664                  * For now assume MCS is already set up correctly, this
 665                  * needs to be fixed.
 666                  */
 667                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 668                         WARN_ON(rates[i].idx > 76);
 669
 670                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 671                             info->control.use_cts_prot)
 672                                 rates[i].flags |=
 673                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 674                         continue;
 675                 }
 676
 677                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 678                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 679                         continue;
 680                 }
 681
 682                 /* set up RTS protection if desired */
 683                 if (info->control.use_rts) {
 684                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 685                         info->control.use_cts_prot = false;
 686                 }
 687
 688                 /* RC is busted */
 689                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 690                         rates[i].idx = -1;
 691                         continue;
 692                 }
 693
 694                 rate = &sband->bitrates[rates[i].idx];
 695
 696                 /* set up short preamble */
 697                 if (info->control.short_preamble &&
 698                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 699                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 700
 701                 /* set up G protection */
 702                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 703                     info->control.use_cts_prot &&
 704                     rate->flags & IEEE80211_RATE_ERP_G)
 705                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 706         }
 707 }
 708
 709
 710 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 711                                         struct ieee80211_tx_info *info,
 712                                         struct ieee80211_tx_rate *rates,
 713                                         int max_rates)
 714 {
 715         struct ieee80211_sta_rates *ratetbl = NULL;
 716         int i;
 717
 718         if (sta && !info->control.skip_table)
 719                 ratetbl = rcu_dereference(sta->rates);
 720
 721         /* Fill remaining rate slots with data from the sta rate table. */
 722         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 723         for (i = 0; i < max_rates; i++) {
 724                 if (i < ARRAY_SIZE(info->control.rates) &&
 725                     info->control.rates[i].idx >= 0 &&
 726                     info->control.rates[i].count) {
 727                         if (rates != info->control.rates)
 728                                 rates[i] = info->control.rates[i];
 729                 } else if (ratetbl) {
 730                         rates[i].idx = ratetbl->rate[i].idx;
 731                         rates[i].flags = ratetbl->rate[i].flags;
 732                         if (info->control.use_rts)
 733                                 rates[i].count = ratetbl->rate[i].count_rts;
 734                         else if (info->control.use_cts_prot)
 735                                 rates[i].count = ratetbl->rate[i].count_cts;
 736                         else
 737                                 rates[i].count = ratetbl->rate[i].count;
 738                 } else {
 739                         rates[i].idx = -1;
 740                         rates[i].count = 0;
 741                 }
 742
 743                 if (rates[i].idx < 0 || !rates[i].count)
 744                         break;
 745         }
 746 }
 747
 748 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 749                                   struct ieee80211_supported_band *sband,
 750                                   struct ieee80211_sta *sta, u32 *mask,
 751                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 752                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 753 {
 754         u32 i, flags;
 755
 756         *mask = sdata->rc_rateidx_mask[sband->band];
 757         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 758         for (i = 0; i < sband->n_bitrates; i++) {
 759                 if ((flags & sband->bitrates[i].flags) != flags)
 760                         *mask &= ~BIT(i);
 761         }
 762
 763         if (*mask == (1 << sband->n_bitrates) - 1 &&
 764             !sdata->rc_has_mcs_mask[sband->band] &&
 765             !sdata->rc_has_vht_mcs_mask[sband->band])
 766                 return false;
 767
 768         if (sdata->rc_has_mcs_mask[sband->band])
 769                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 770                        IEEE80211_HT_MCS_MASK_LEN);
 771         else
 772                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 773
 774         if (sdata->rc_has_vht_mcs_mask[sband->band])
 775                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 776                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 777         else
 778                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 779
 780         if (sta) {
 781                 __le16 sta_vht_cap;
 782                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 783
 784                 /* Filter out rates that the STA does not support */
 785                 *mask &= sta->deflink.supp_rates[sband->band];
 786                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 787                         mcs_mask[i] &= sta->deflink.ht_cap.mcs.rx_mask[i];
 788
 789                 sta_vht_cap = sta->deflink.vht_cap.vht_mcs.rx_mcs_map;
 790                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 791                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 792                         vht_mask[i] &= sta_vht_mask[i];
 793         }
 794
 795         return true;
 796 }
 797
 798 static void
 799 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 800                                 struct ieee80211_supported_band *sband,
 801                                 struct ieee80211_sta_rates *rates)
 802 {
 803         int i;
 804         u32 mask;
 805         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 806         u16 vht_mask[NL80211_VHT_NSS_MAX];
 807         enum nl80211_chan_width chan_width;
 808
 809         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 810                                    mcs_mask, vht_mask))
 811                 return;
 812
 813         chan_width = sta->sdata->vif.bss_conf.chandef.width;
 814         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 815                 if (rates->rate[i].idx < 0)
 816                         break;
 817
 818                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 819                                     sband, chan_width, mask, mcs_mask,
 820                                     vht_mask);
 821         }
 822 }
 823
 824 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 825                                     struct ieee80211_sta *sta,
 826                                     struct ieee80211_supported_band *sband,
 827                                     struct ieee80211_tx_rate *rates,
 828                                     int max_rates)
 829 {
 830         enum nl80211_chan_width chan_width;
 831         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 832         u32 mask;
 833         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 834         int i;
 835
 836         /*
 837          * Try to enforce the rateidx mask the user wanted. skip this if the
 838          * default mask (allow all rates) is used to save some processing for
 839          * the common case.
 840          */
 841         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 842                                    vht_mask))
 843                 return;
 844
 845         /*
 846          * Make sure the rate index selected for each TX rate is
 847          * included in the configured mask and change the rate indexes
 848          * if needed.
 849          */
 850         chan_width = sdata->vif.bss_conf.chandef.width;
 851         for (i = 0; i < max_rates; i++) {
 852                 /* Skip invalid rates */
 853                 if (rates[i].idx < 0)
 854                         break;
 855
 856                 rate_flags = rates[i].flags;
 857                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 858                                     chan_width, mask, mcs_mask, vht_mask);
 859                 rates[i].flags = rate_flags;
 860         }
 861 }
 862
 863 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 864                             struct ieee80211_sta *sta,
 865                             struct sk_buff *skb,
 866                             struct ieee80211_tx_rate *dest,
 867                             int max_rates)
 868 {
 869         struct ieee80211_sub_if_data *sdata;
 870         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 871         struct ieee80211_supported_band *sband;
 872
 873         rate_control_fill_sta_table(sta, info, dest, max_rates);
 874
 875         if (!vif)
 876                 return;
 877
 878         sdata = vif_to_sdata(vif);
 879         sband = sdata->local->hw.wiphy->bands[info->band];
 880
 881         if (ieee80211_is_tx_data(skb))
 882                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 883
 884         if (dest[0].idx < 0)
 885                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 886                                         sdata->rc_rateidx_mask[info->band]);
 887
 888         if (sta)
 889                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 890 }
 891 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 892
 893 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 894                            struct sta_info *sta,
 895                            struct ieee80211_tx_rate_control *txrc)
 896 {
 897         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 898         void *priv_sta = NULL;
 899         struct ieee80211_sta *ista = NULL;
 900         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 901         int i;
 902
 903         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 904                 info->control.rates[i].idx = -1;
 905                 info->control.rates[i].flags = 0;
 906                 info->control.rates[i].count = 0;
 907         }
 908
 909         if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 910                 return;
 911
 912         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 913                 return;
 914
 915         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 916                 ista = &sta->sta;
 917                 priv_sta = sta->rate_ctrl_priv;
 918         }
 919
 920         if (ista) {
 921                 spin_lock_bh(&sta->rate_ctrl_lock);
 922                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 923                 spin_unlock_bh(&sta->rate_ctrl_lock);
 924         } else {
 925                 rate_control_send_low(NULL, txrc);
 926         }
 927
 928         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 929                 return;
 930
 931         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 932                                info->control.rates,
 933                                ARRAY_SIZE(info->control.rates));
 934 }
 935
 936 int rate_control_set_rates(struct ieee80211_hw *hw,
 937                            struct ieee80211_sta *pubsta,
 938                            struct ieee80211_sta_rates *rates)
 939 {
 940         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 941         struct ieee80211_sta_rates *old;
 942         struct ieee80211_supported_band *sband;
 943
 944         sband = ieee80211_get_sband(sta->sdata);
 945         if (!sband)
 946                 return -EINVAL;
 947         rate_control_apply_mask_ratetbl(sta, sband, rates);
 948         /*
 949          * mac80211 guarantees that this function will not be called
 950          * concurrently, so the following RCU access is safe, even without
 951          * extra locking. This can not be checked easily, so we just set
 952          * the condition to true.
 953          */
 954         old = rcu_dereference_protected(pubsta->rates, true);
 955         rcu_assign_pointer(pubsta->rates, rates);
 956         if (old)
 957                 kfree_rcu(old, rcu_head);
 958
 959         if (sta->uploaded)
 960                 drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 961
 962         ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
 963
 964         return 0;
 965 }
 966 EXPORT_SYMBOL(rate_control_set_rates);
 967
 968 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 969                                  const char *name)
 970 {
 971         struct rate_control_ref *ref;
 972
 973         ASSERT_RTNL();
 974
 975         if (local->open_count)
 976                 return -EBUSY;
 977
 978         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 979                 if (WARN_ON(!local->ops->set_rts_threshold))
 980                         return -EINVAL;
 981                 return 0;
 982         }
 983
 984         ref = rate_control_alloc(name, local);
 985         if (!ref) {
 986                 wiphy_warn(local->hw.wiphy,
 987                            "Failed to select rate control algorithm\n");
 988                 return -ENOENT;
 989         }
 990
 991         WARN_ON(local->rate_ctrl);
 992         local->rate_ctrl = ref;
 993
 994         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 995                     ref->ops->name);
 996
 997         return 0;
 998 }
 999
1000 void rate_control_deinitialize(struct ieee80211_local *local)
1001 {
1002         struct rate_control_ref *ref;
1003
1004         ref = local->rate_ctrl;
1005
1006         if (!ref)
1007                 return;
1008
1009         local->rate_ctrl = NULL;
1010         rate_control_free(local, ref);
1011 }