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  */
   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
  17 struct rate_control_alg {
  18         struct list_head list;
  19         const struct rate_control_ops *ops;
  20 };
  21
  22 static LIST_HEAD(rate_ctrl_algs);
  23 static DEFINE_MUTEX(rate_ctrl_mutex);
  24
  25 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  26 module_param(ieee80211_default_rc_algo, charp, 0644);
  27 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  28                  "Default rate control algorithm for mac80211 to use");
  29
  30 void 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
  69 void 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
  91 void 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
 118 int 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 }
 147 EXPORT_SYMBOL(ieee80211_rate_control_register);
 148
 149 void 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 }
 163 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 164
 165 static const struct rate_control_ops *
 166 ieee80211_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. */
 186 static const struct rate_control_ops *
 187 ieee80211_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
 214 static 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
 224 const struct file_operations rcname_ops = {
 225         .read = rcname_read,
 226         .open = simple_open,
 227         .llseek = default_llseek,
 228 };
 229 #endif
 230
 231 static struct rate_control_ref *
 232 rate_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
 248 free:
 249         kfree(ref);
 250         return NULL;
 251 }
 252
 253 static 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
 266 void 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
 297 static 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_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 301         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 302         __le16 fc;
 303
 304         fc = hdr->frame_control;
 305
 306         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 307                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 308                 !ieee80211_is_data(fc);
 309 }
 310
 311 static void rc_send_low_basicrate(struct ieee80211_tx_rate *rate,
 312                                   u32 basic_rates,
 313                                   struct ieee80211_supported_band *sband)
 314 {
 315         u8 i;
 316
 317         if (sband->band == NL80211_BAND_S1GHZ) {
 318                 /* TODO */
 319                 rate->flags |= IEEE80211_TX_RC_S1G_MCS;
 320                 rate->idx = 0;
 321                 return;
 322         }
 323
 324         if (basic_rates == 0)
 325                 return; /* assume basic rates unknown and accept rate */
 326         if (rate->idx < 0)
 327                 return;
 328         if (basic_rates & (1 << rate->idx))
 329                 return; /* selected rate is a basic rate */
 330
 331         for (i = rate->idx + 1; i <= sband->n_bitrates; i++) {
 332                 if (basic_rates & (1 << i)) {
 333                         rate->idx = i;
 334                         return;
 335                 }
 336         }
 337
 338         /* could not find a basic rate; use original selection */
 339 }
 340
 341 static void __rate_control_send_low(struct ieee80211_hw *hw,
 342                                     struct ieee80211_supported_band *sband,
 343                                     struct ieee80211_sta *sta,
 344                                     struct ieee80211_tx_info *info,
 345                                     u32 rate_mask)
 346 {
 347         int i;
 348         u32 rate_flags =
 349                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 350
 351         if (sband->band == NL80211_BAND_S1GHZ) {
 352                 info->control.rates[0].flags |= IEEE80211_TX_RC_S1G_MCS;
 353                 info->control.rates[0].idx = 0;
 354                 return;
 355         }
 356
 357         if ((sband->band == NL80211_BAND_2GHZ) &&
 358             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 359                 rate_flags |= IEEE80211_RATE_ERP_G;
 360
 361         info->control.rates[0].idx = 0;
 362         for (i = 0; i < sband->n_bitrates; i++) {
 363                 if (!(rate_mask & BIT(i)))
 364                         continue;
 365
 366                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 367                         continue;
 368
 369                 if (!rate_supported(sta, sband->band, i))
 370                         continue;
 371
 372                 info->control.rates[0].idx = i;
 373                 break;
 374         }
 375         WARN_ONCE(i == sband->n_bitrates,
 376                   "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 377                   sta ? sta->addr : NULL,
 378                   sta ? sta->supp_rates[sband->band] : -1,
 379                   sband->band,
 380                   rate_mask, rate_flags);
 381
 382         info->control.rates[0].count =
 383                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 384                 1 : hw->max_rate_tries;
 385
 386         info->control.skip_table = 1;
 387 }
 388
 389
 390 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 391                                   struct ieee80211_tx_rate_control *txrc)
 392 {
 393         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 394         struct ieee80211_supported_band *sband = txrc->sband;
 395         struct sta_info *sta;
 396         int mcast_rate;
 397         bool use_basicrate = 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
 426 static 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
 450 static 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
 487 static 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
 525 static 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
 610 static 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
 713 static 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
 751 static 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
 801 static void
 802 rate_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
 827 static 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
 866 void 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_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 874         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 875         struct ieee80211_supported_band *sband;
 876
 877         rate_control_fill_sta_table(sta, info, dest, max_rates);
 878
 879         if (!vif)
 880                 return;
 881
 882         sdata = vif_to_sdata(vif);
 883         sband = sdata->local->hw.wiphy->bands[info->band];
 884
 885         if (ieee80211_is_data(hdr->frame_control))
 886                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 887
 888         if (dest[0].idx < 0)
 889                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 890                                         sdata->rc_rateidx_mask[info->band]);
 891
 892         if (sta)
 893                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 894 }
 895 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 896
 897 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 898                            struct sta_info *sta,
 899                            struct ieee80211_tx_rate_control *txrc)
 900 {
 901         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 902         void *priv_sta = NULL;
 903         struct ieee80211_sta *ista = NULL;
 904         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 905         int i;
 906
 907         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 908                 info->control.rates[i].idx = -1;
 909                 info->control.rates[i].flags = 0;
 910                 info->control.rates[i].count = 0;
 911         }
 912
 913         if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 914                 return;
 915
 916         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 917                 return;
 918
 919         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 920                 ista = &sta->sta;
 921                 priv_sta = sta->rate_ctrl_priv;
 922         }
 923
 924         if (ista) {
 925                 spin_lock_bh(&sta->rate_ctrl_lock);
 926                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 927                 spin_unlock_bh(&sta->rate_ctrl_lock);
 928         } else {
 929                 rate_control_send_low(NULL, txrc);
 930         }
 931
 932         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 933                 return;
 934
 935         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 936                                info->control.rates,
 937                                ARRAY_SIZE(info->control.rates));
 938 }
 939
 940 int rate_control_set_rates(struct ieee80211_hw *hw,
 941                            struct ieee80211_sta *pubsta,
 942                            struct ieee80211_sta_rates *rates)
 943 {
 944         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 945         struct ieee80211_sta_rates *old;
 946         struct ieee80211_supported_band *sband;
 947
 948         sband = ieee80211_get_sband(sta->sdata);
 949         if (!sband)
 950                 return -EINVAL;
 951         rate_control_apply_mask_ratetbl(sta, sband, rates);
 952         /*
 953          * mac80211 guarantees that this function will not be called
 954          * concurrently, so the following RCU access is safe, even without
 955          * extra locking. This can not be checked easily, so we just set
 956          * the condition to true.
 957          */
 958         old = rcu_dereference_protected(pubsta->rates, true);
 959         rcu_assign_pointer(pubsta->rates, rates);
 960         if (old)
 961                 kfree_rcu(old, rcu_head);
 962
 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 }
 969 EXPORT_SYMBOL(rate_control_set_rates);
 970
 971 int 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
1003 void 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 }