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         spin_lock_bh(&sta->rate_ctrl_lock);
  55         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  56                             priv_sta);
  57         spin_unlock_bh(&sta->rate_ctrl_lock);
  58         rcu_read_unlock();
  59         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  60 }
  61
  62 void rate_control_tx_status(struct ieee80211_local *local,
  63                             struct ieee80211_supported_band *sband,
  64                             struct ieee80211_tx_status *st)
  65 {
  66         struct rate_control_ref *ref = local->rate_ctrl;
  67         struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  68         void *priv_sta = sta->rate_ctrl_priv;
  69
  70         if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  71                 return;
  72
  73         spin_lock_bh(&sta->rate_ctrl_lock);
  74         if (ref->ops->tx_status_ext)
  75                 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
  76         else if (st->skb)
  77                 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
  78         else
  79                 WARN_ON_ONCE(1);
  80
  81         spin_unlock_bh(&sta->rate_ctrl_lock);
  82 }
  83
  84 void rate_control_rate_update(struct ieee80211_local *local,
  85                                     struct ieee80211_supported_band *sband,
  86                                     struct sta_info *sta, u32 changed)
  87 {
  88         struct rate_control_ref *ref = local->rate_ctrl;
  89         struct ieee80211_sta *ista = &sta->sta;
  90         void *priv_sta = sta->rate_ctrl_priv;
  91         struct ieee80211_chanctx_conf *chanctx_conf;
  92
  93         if (ref && ref->ops->rate_update) {
  94                 rcu_read_lock();
  95
  96                 chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  97                 if (WARN_ON(!chanctx_conf)) {
  98                         rcu_read_unlock();
  99                         return;
 100                 }
 101
 102                 spin_lock_bh(&sta->rate_ctrl_lock);
 103                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 104                                       ista, priv_sta, changed);
 105                 spin_unlock_bh(&sta->rate_ctrl_lock);
 106                 rcu_read_unlock();
 107         }
 108         drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 109 }
 110
 111 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 112 {
 113         struct rate_control_alg *alg;
 114
 115         if (!ops->name)
 116                 return -EINVAL;
 117
 118         mutex_lock(&rate_ctrl_mutex);
 119         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 120                 if (!strcmp(alg->ops->name, ops->name)) {
 121                         /* don't register an algorithm twice */
 122                         WARN_ON(1);
 123                         mutex_unlock(&rate_ctrl_mutex);
 124                         return -EALREADY;
 125                 }
 126         }
 127
 128         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 129         if (alg == NULL) {
 130                 mutex_unlock(&rate_ctrl_mutex);
 131                 return -ENOMEM;
 132         }
 133         alg->ops = ops;
 134
 135         list_add_tail(&alg->list, &rate_ctrl_algs);
 136         mutex_unlock(&rate_ctrl_mutex);
 137
 138         return 0;
 139 }
 140 EXPORT_SYMBOL(ieee80211_rate_control_register);
 141
 142 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 143 {
 144         struct rate_control_alg *alg;
 145
 146         mutex_lock(&rate_ctrl_mutex);
 147         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 148                 if (alg->ops == ops) {
 149                         list_del(&alg->list);
 150                         kfree(alg);
 151                         break;
 152                 }
 153         }
 154         mutex_unlock(&rate_ctrl_mutex);
 155 }
 156 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 157
 158 static const struct rate_control_ops *
 159 ieee80211_try_rate_control_ops_get(const char *name)
 160 {
 161         struct rate_control_alg *alg;
 162         const struct rate_control_ops *ops = NULL;
 163
 164         if (!name)
 165                 return NULL;
 166
 167         mutex_lock(&rate_ctrl_mutex);
 168         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 169                 if (!strcmp(alg->ops->name, name)) {
 170                         ops = alg->ops;
 171                         break;
 172                 }
 173         }
 174         mutex_unlock(&rate_ctrl_mutex);
 175         return ops;
 176 }
 177
 178 /* Get the rate control algorithm. */
 179 static const struct rate_control_ops *
 180 ieee80211_rate_control_ops_get(const char *name)
 181 {
 182         const struct rate_control_ops *ops;
 183         const char *alg_name;
 184
 185         kernel_param_lock(THIS_MODULE);
 186         if (!name)
 187                 alg_name = ieee80211_default_rc_algo;
 188         else
 189                 alg_name = name;
 190
 191         ops = ieee80211_try_rate_control_ops_get(alg_name);
 192         if (!ops && name)
 193                 /* try default if specific alg requested but not found */
 194                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 195
 196         /* Note: check for > 0 is intentional to avoid clang warning */
 197         if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 198                 /* try built-in one if specific alg requested but not found */
 199                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 200
 201         kernel_param_unlock(THIS_MODULE);
 202
 203         return ops;
 204 }
 205
 206 #ifdef CONFIG_MAC80211_DEBUGFS
 207 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 208                            size_t count, loff_t *ppos)
 209 {
 210         struct rate_control_ref *ref = file->private_data;
 211         int len = strlen(ref->ops->name);
 212
 213         return simple_read_from_buffer(userbuf, count, ppos,
 214                                        ref->ops->name, len);
 215 }
 216
 217 static const struct file_operations rcname_ops = {
 218         .read = rcname_read,
 219         .open = simple_open,
 220         .llseek = default_llseek,
 221 };
 222 #endif
 223
 224 static struct rate_control_ref *rate_control_alloc(const char *name,
 225                                             struct ieee80211_local *local)
 226 {
 227         struct dentry *debugfsdir = NULL;
 228         struct rate_control_ref *ref;
 229
 230         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 231         if (!ref)
 232                 return NULL;
 233         ref->ops = ieee80211_rate_control_ops_get(name);
 234         if (!ref->ops)
 235                 goto free;
 236
 237 #ifdef CONFIG_MAC80211_DEBUGFS
 238         debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
 239         local->debugfs.rcdir = debugfsdir;
 240         debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
 241 #endif
 242
 243         ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
 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         if (WARN_ON_ONCE(!basic_rates))
 277                 return;
 278
 279         band = sdata->vif.bss_conf.chandef.chan->band;
 280         user_mask = sdata->rc_rateidx_mask[band];
 281         sband = local->hw.wiphy->bands[band];
 282
 283         if (user_mask & basic_rates)
 284                 return;
 285
 286         sdata_dbg(sdata,
 287                   "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 288                   basic_rates, user_mask, band);
 289         sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 290 }
 291
 292 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 293 {
 294         struct sk_buff *skb = txrc->skb;
 295         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 296         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 297         __le16 fc;
 298
 299         fc = hdr->frame_control;
 300
 301         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 302                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 303                 !ieee80211_is_data(fc);
 304 }
 305
 306 static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
 307                                   struct ieee80211_supported_band *sband)
 308 {
 309         u8 i;
 310
 311         if (basic_rates == 0)
 312                 return; /* assume basic rates unknown and accept rate */
 313         if (*idx < 0)
 314                 return;
 315         if (basic_rates & (1 << *idx))
 316                 return; /* selected rate is a basic rate */
 317
 318         for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 319                 if (basic_rates & (1 << i)) {
 320                         *idx = i;
 321                         return;
 322                 }
 323         }
 324
 325         /* could not find a basic rate; use original selection */
 326 }
 327
 328 static void __rate_control_send_low(struct ieee80211_hw *hw,
 329                                     struct ieee80211_supported_band *sband,
 330                                     struct ieee80211_sta *sta,
 331                                     struct ieee80211_tx_info *info,
 332                                     u32 rate_mask)
 333 {
 334         int i;
 335         u32 rate_flags =
 336                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 337
 338         if ((sband->band == NL80211_BAND_2GHZ) &&
 339             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 340                 rate_flags |= IEEE80211_RATE_ERP_G;
 341
 342         info->control.rates[0].idx = 0;
 343         for (i = 0; i < sband->n_bitrates; i++) {
 344                 if (!(rate_mask & BIT(i)))
 345                         continue;
 346
 347                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 348                         continue;
 349
 350                 if (!rate_supported(sta, sband->band, i))
 351                         continue;
 352
 353                 info->control.rates[0].idx = i;
 354                 break;
 355         }
 356         WARN_ONCE(i == sband->n_bitrates,
 357                   "no supported rates for sta %pM (0x%x, band %d) in rate_mask 0x%x with flags 0x%x\n",
 358                   sta ? sta->addr : NULL,
 359                   sta ? sta->supp_rates[sband->band] : -1,
 360                   sband->band,
 361                   rate_mask, rate_flags);
 362
 363         info->control.rates[0].count =
 364                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 365                 1 : hw->max_rate_tries;
 366
 367         info->control.skip_table = 1;
 368 }
 369
 370
 371 static bool rate_control_send_low(struct ieee80211_sta *pubsta,
 372                                   struct ieee80211_tx_rate_control *txrc)
 373 {
 374         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 375         struct ieee80211_supported_band *sband = txrc->sband;
 376         struct sta_info *sta;
 377         int mcast_rate;
 378         bool use_basicrate = false;
 379
 380         if (!pubsta || rc_no_data_or_no_ack_use_min(txrc)) {
 381                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 382                                         txrc->rate_idx_mask);
 383
 384                 if (!pubsta && txrc->bss) {
 385                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 386                         if (mcast_rate > 0) {
 387                                 info->control.rates[0].idx = mcast_rate - 1;
 388                                 return true;
 389                         }
 390                         use_basicrate = true;
 391                 } else if (pubsta) {
 392                         sta = container_of(pubsta, struct sta_info, sta);
 393                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 394                                 use_basicrate = true;
 395                 }
 396
 397                 if (use_basicrate)
 398                         rc_send_low_basicrate(&info->control.rates[0].idx,
 399                                               txrc->bss_conf->basic_rates,
 400                                               sband);
 401
 402                 return true;
 403         }
 404         return false;
 405 }
 406
 407 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 408 {
 409         int j;
 410
 411         /* See whether the selected rate or anything below it is allowed. */
 412         for (j = *rate_idx; j >= 0; j--) {
 413                 if (mask & (1 << j)) {
 414                         /* Okay, found a suitable rate. Use it. */
 415                         *rate_idx = j;
 416                         return true;
 417                 }
 418         }
 419
 420         /* Try to find a higher rate that would be allowed */
 421         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 422                 if (mask & (1 << j)) {
 423                         /* Okay, found a suitable rate. Use it. */
 424                         *rate_idx = j;
 425                         return true;
 426                 }
 427         }
 428         return false;
 429 }
 430
 431 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 432 {
 433         int i, j;
 434         int ridx, rbit;
 435
 436         ridx = *rate_idx / 8;
 437         rbit = *rate_idx % 8;
 438
 439         /* sanity check */
 440         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 441                 return false;
 442
 443         /* See whether the selected rate or anything below it is allowed. */
 444         for (i = ridx; i >= 0; i--) {
 445                 for (j = rbit; j >= 0; j--)
 446                         if (mcs_mask[i] & BIT(j)) {
 447                                 *rate_idx = i * 8 + j;
 448                                 return true;
 449                         }
 450                 rbit = 7;
 451         }
 452
 453         /* Try to find a higher rate that would be allowed */
 454         ridx = (*rate_idx + 1) / 8;
 455         rbit = (*rate_idx + 1) % 8;
 456
 457         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 458                 for (j = rbit; j < 8; j++)
 459                         if (mcs_mask[i] & BIT(j)) {
 460                                 *rate_idx = i * 8 + j;
 461                                 return true;
 462                         }
 463                 rbit = 0;
 464         }
 465         return false;
 466 }
 467
 468 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 469 {
 470         int i, j;
 471         int ridx, rbit;
 472
 473         ridx = *rate_idx >> 4;
 474         rbit = *rate_idx & 0xf;
 475
 476         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 477                 return false;
 478
 479         /* See whether the selected rate or anything below it is allowed. */
 480         for (i = ridx; i >= 0; i--) {
 481                 for (j = rbit; j >= 0; j--) {
 482                         if (vht_mask[i] & BIT(j)) {
 483                                 *rate_idx = (i << 4) | j;
 484                                 return true;
 485                         }
 486                 }
 487                 rbit = 15;
 488         }
 489
 490         /* Try to find a higher rate that would be allowed */
 491         ridx = (*rate_idx + 1) >> 4;
 492         rbit = (*rate_idx + 1) & 0xf;
 493
 494         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 495                 for (j = rbit; j < 16; j++) {
 496                         if (vht_mask[i] & BIT(j)) {
 497                                 *rate_idx = (i << 4) | j;
 498                                 return true;
 499                         }
 500                 }
 501                 rbit = 0;
 502         }
 503         return false;
 504 }
 505
 506 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 507                                 struct ieee80211_supported_band *sband,
 508                                 enum nl80211_chan_width chan_width,
 509                                 u32 mask,
 510                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 511                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 512 {
 513         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 514                 /* handle VHT rates */
 515                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 516                         return;
 517
 518                 *rate_idx = 0;
 519                 /* keep protection flags */
 520                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 521                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 522                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 523
 524                 *rate_flags |= IEEE80211_TX_RC_MCS;
 525                 if (chan_width == NL80211_CHAN_WIDTH_40)
 526                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 527
 528                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 529                         return;
 530
 531                 /* also try the legacy rates. */
 532                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 533                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 534                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 535                                                mask))
 536                         return;
 537         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 538                 /* handle HT rates */
 539                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 540                         return;
 541
 542                 /* also try the legacy rates. */
 543                 *rate_idx = 0;
 544                 /* keep protection flags */
 545                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 546                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 547                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 548                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 549                                                mask))
 550                         return;
 551         } else {
 552                 /* handle legacy rates */
 553                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 554                                                mask))
 555                         return;
 556
 557                 /* if HT BSS, and we handle a data frame, also try HT rates */
 558                 switch (chan_width) {
 559                 case NL80211_CHAN_WIDTH_20_NOHT:
 560                 case NL80211_CHAN_WIDTH_5:
 561                 case NL80211_CHAN_WIDTH_10:
 562                         return;
 563                 default:
 564                         break;
 565                 }
 566
 567                 *rate_idx = 0;
 568                 /* keep protection flags */
 569                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 570                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 571                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 572
 573                 *rate_flags |= IEEE80211_TX_RC_MCS;
 574
 575                 if (chan_width == NL80211_CHAN_WIDTH_40)
 576                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 577
 578                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 579                         return;
 580         }
 581
 582         /*
 583          * Uh.. No suitable rate exists. This should not really happen with
 584          * sane TX rate mask configurations. However, should someone manage to
 585          * configure supported rates and TX rate mask in incompatible way,
 586          * allow the frame to be transmitted with whatever the rate control
 587          * selected.
 588          */
 589 }
 590
 591 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 592                                 struct ieee80211_supported_band *sband,
 593                                 struct ieee80211_tx_info *info,
 594                                 struct ieee80211_tx_rate *rates,
 595                                 int max_rates)
 596 {
 597         struct ieee80211_rate *rate;
 598         bool inval = false;
 599         int i;
 600
 601         /*
 602          * Set up the RTS/CTS rate as the fastest basic rate
 603          * that is not faster than the data rate unless there
 604          * is no basic rate slower than the data rate, in which
 605          * case we pick the slowest basic rate
 606          *
 607          * XXX: Should this check all retry rates?
 608          */
 609         if (!(rates[0].flags &
 610               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 611                 u32 basic_rates = vif->bss_conf.basic_rates;
 612                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 613
 614                 rate = &sband->bitrates[rates[0].idx];
 615
 616                 for (i = 0; i < sband->n_bitrates; i++) {
 617                         /* must be a basic rate */
 618                         if (!(basic_rates & BIT(i)))
 619                                 continue;
 620                         /* must not be faster than the data rate */
 621                         if (sband->bitrates[i].bitrate > rate->bitrate)
 622                                 continue;
 623                         /* maximum */
 624                         if (sband->bitrates[baserate].bitrate <
 625                              sband->bitrates[i].bitrate)
 626                                 baserate = i;
 627                 }
 628
 629                 info->control.rts_cts_rate_idx = baserate;
 630         }
 631
 632         for (i = 0; i < max_rates; i++) {
 633                 /*
 634                  * make sure there's no valid rate following
 635                  * an invalid one, just in case drivers don't
 636                  * take the API seriously to stop at -1.
 637                  */
 638                 if (inval) {
 639                         rates[i].idx = -1;
 640                         continue;
 641                 }
 642                 if (rates[i].idx < 0) {
 643                         inval = true;
 644                         continue;
 645                 }
 646
 647                 /*
 648                  * For now assume MCS is already set up correctly, this
 649                  * needs to be fixed.
 650                  */
 651                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 652                         WARN_ON(rates[i].idx > 76);
 653
 654                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 655                             info->control.use_cts_prot)
 656                                 rates[i].flags |=
 657                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 658                         continue;
 659                 }
 660
 661                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 662                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 663                         continue;
 664                 }
 665
 666                 /* set up RTS protection if desired */
 667                 if (info->control.use_rts) {
 668                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 669                         info->control.use_cts_prot = false;
 670                 }
 671
 672                 /* RC is busted */
 673                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 674                         rates[i].idx = -1;
 675                         continue;
 676                 }
 677
 678                 rate = &sband->bitrates[rates[i].idx];
 679
 680                 /* set up short preamble */
 681                 if (info->control.short_preamble &&
 682                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 683                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 684
 685                 /* set up G protection */
 686                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 687                     info->control.use_cts_prot &&
 688                     rate->flags & IEEE80211_RATE_ERP_G)
 689                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 690         }
 691 }
 692
 693
 694 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 695                                         struct ieee80211_tx_info *info,
 696                                         struct ieee80211_tx_rate *rates,
 697                                         int max_rates)
 698 {
 699         struct ieee80211_sta_rates *ratetbl = NULL;
 700         int i;
 701
 702         if (sta && !info->control.skip_table)
 703                 ratetbl = rcu_dereference(sta->rates);
 704
 705         /* Fill remaining rate slots with data from the sta rate table. */
 706         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 707         for (i = 0; i < max_rates; i++) {
 708                 if (i < ARRAY_SIZE(info->control.rates) &&
 709                     info->control.rates[i].idx >= 0 &&
 710                     info->control.rates[i].count) {
 711                         if (rates != info->control.rates)
 712                                 rates[i] = info->control.rates[i];
 713                 } else if (ratetbl) {
 714                         rates[i].idx = ratetbl->rate[i].idx;
 715                         rates[i].flags = ratetbl->rate[i].flags;
 716                         if (info->control.use_rts)
 717                                 rates[i].count = ratetbl->rate[i].count_rts;
 718                         else if (info->control.use_cts_prot)
 719                                 rates[i].count = ratetbl->rate[i].count_cts;
 720                         else
 721                                 rates[i].count = ratetbl->rate[i].count;
 722                 } else {
 723                         rates[i].idx = -1;
 724                         rates[i].count = 0;
 725                 }
 726
 727                 if (rates[i].idx < 0 || !rates[i].count)
 728                         break;
 729         }
 730 }
 731
 732 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 733                                   struct ieee80211_supported_band *sband,
 734                                   struct ieee80211_sta *sta, u32 *mask,
 735                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 736                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 737 {
 738         u32 i, flags;
 739
 740         *mask = sdata->rc_rateidx_mask[sband->band];
 741         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 742         for (i = 0; i < sband->n_bitrates; i++) {
 743                 if ((flags & sband->bitrates[i].flags) != flags)
 744                         *mask &= ~BIT(i);
 745         }
 746
 747         if (*mask == (1 << sband->n_bitrates) - 1 &&
 748             !sdata->rc_has_mcs_mask[sband->band] &&
 749             !sdata->rc_has_vht_mcs_mask[sband->band])
 750                 return false;
 751
 752         if (sdata->rc_has_mcs_mask[sband->band])
 753                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 754                        IEEE80211_HT_MCS_MASK_LEN);
 755         else
 756                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 757
 758         if (sdata->rc_has_vht_mcs_mask[sband->band])
 759                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 760                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 761         else
 762                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 763
 764         if (sta) {
 765                 __le16 sta_vht_cap;
 766                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 767
 768                 /* Filter out rates that the STA does not support */
 769                 *mask &= sta->supp_rates[sband->band];
 770                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 771                         mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 772
 773                 sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
 774                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 775                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 776                         vht_mask[i] &= sta_vht_mask[i];
 777         }
 778
 779         return true;
 780 }
 781
 782 static void
 783 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 784                                 struct ieee80211_supported_band *sband,
 785                                 struct ieee80211_sta_rates *rates)
 786 {
 787         int i;
 788         u32 mask;
 789         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 790         u16 vht_mask[NL80211_VHT_NSS_MAX];
 791         enum nl80211_chan_width chan_width;
 792
 793         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 794                                    mcs_mask, vht_mask))
 795                 return;
 796
 797         chan_width = sta->sdata->vif.bss_conf.chandef.width;
 798         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 799                 if (rates->rate[i].idx < 0)
 800                         break;
 801
 802                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 803                                     sband, chan_width, mask, mcs_mask,
 804                                     vht_mask);
 805         }
 806 }
 807
 808 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 809                                     struct ieee80211_sta *sta,
 810                                     struct ieee80211_supported_band *sband,
 811                                     struct ieee80211_tx_rate *rates,
 812                                     int max_rates)
 813 {
 814         enum nl80211_chan_width chan_width;
 815         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 816         u32 mask;
 817         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 818         int i;
 819
 820         /*
 821          * Try to enforce the rateidx mask the user wanted. skip this if the
 822          * default mask (allow all rates) is used to save some processing for
 823          * the common case.
 824          */
 825         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 826                                    vht_mask))
 827                 return;
 828
 829         /*
 830          * Make sure the rate index selected for each TX rate is
 831          * included in the configured mask and change the rate indexes
 832          * if needed.
 833          */
 834         chan_width = sdata->vif.bss_conf.chandef.width;
 835         for (i = 0; i < max_rates; i++) {
 836                 /* Skip invalid rates */
 837                 if (rates[i].idx < 0)
 838                         break;
 839
 840                 rate_flags = rates[i].flags;
 841                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 842                                     chan_width, mask, mcs_mask, vht_mask);
 843                 rates[i].flags = rate_flags;
 844         }
 845 }
 846
 847 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 848                             struct ieee80211_sta *sta,
 849                             struct sk_buff *skb,
 850                             struct ieee80211_tx_rate *dest,
 851                             int max_rates)
 852 {
 853         struct ieee80211_sub_if_data *sdata;
 854         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 855         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 856         struct ieee80211_supported_band *sband;
 857
 858         rate_control_fill_sta_table(sta, info, dest, max_rates);
 859
 860         if (!vif)
 861                 return;
 862
 863         sdata = vif_to_sdata(vif);
 864         sband = sdata->local->hw.wiphy->bands[info->band];
 865
 866         if (ieee80211_is_data(hdr->frame_control))
 867                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 868
 869         if (dest[0].idx < 0)
 870                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 871                                         sdata->rc_rateidx_mask[info->band]);
 872
 873         if (sta)
 874                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 875 }
 876 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 877
 878 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 879                            struct sta_info *sta,
 880                            struct ieee80211_tx_rate_control *txrc)
 881 {
 882         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 883         void *priv_sta = NULL;
 884         struct ieee80211_sta *ista = NULL;
 885         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 886         int i;
 887
 888         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 889                 info->control.rates[i].idx = -1;
 890                 info->control.rates[i].flags = 0;
 891                 info->control.rates[i].count = 0;
 892         }
 893
 894         if (rate_control_send_low(sta ? &sta->sta : NULL, txrc))
 895                 return;
 896
 897         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 898                 return;
 899
 900         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 901                 ista = &sta->sta;
 902                 priv_sta = sta->rate_ctrl_priv;
 903         }
 904
 905         if (ista) {
 906                 spin_lock_bh(&sta->rate_ctrl_lock);
 907                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 908                 spin_unlock_bh(&sta->rate_ctrl_lock);
 909         } else {
 910                 rate_control_send_low(NULL, txrc);
 911         }
 912
 913         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 914                 return;
 915
 916         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 917                                info->control.rates,
 918                                ARRAY_SIZE(info->control.rates));
 919 }
 920
 921 int rate_control_set_rates(struct ieee80211_hw *hw,
 922                            struct ieee80211_sta *pubsta,
 923                            struct ieee80211_sta_rates *rates)
 924 {
 925         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 926         struct ieee80211_sta_rates *old;
 927         struct ieee80211_supported_band *sband;
 928
 929         sband = ieee80211_get_sband(sta->sdata);
 930         if (!sband)
 931                 return -EINVAL;
 932         rate_control_apply_mask_ratetbl(sta, sband, rates);
 933         /*
 934          * mac80211 guarantees that this function will not be called
 935          * concurrently, so the following RCU access is safe, even without
 936          * extra locking. This can not be checked easily, so we just set
 937          * the condition to true.
 938          */
 939         old = rcu_dereference_protected(pubsta->rates, true);
 940         rcu_assign_pointer(pubsta->rates, rates);
 941         if (old)
 942                 kfree_rcu(old, rcu_head);
 943
 944         drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 945
 946         ieee80211_sta_set_expected_throughput(pubsta, sta_get_expected_throughput(sta));
 947
 948         return 0;
 949 }
 950 EXPORT_SYMBOL(rate_control_set_rates);
 951
 952 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 953                                  const char *name)
 954 {
 955         struct rate_control_ref *ref;
 956
 957         ASSERT_RTNL();
 958
 959         if (local->open_count)
 960                 return -EBUSY;
 961
 962         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 963                 if (WARN_ON(!local->ops->set_rts_threshold))
 964                         return -EINVAL;
 965                 return 0;
 966         }
 967
 968         ref = rate_control_alloc(name, local);
 969         if (!ref) {
 970                 wiphy_warn(local->hw.wiphy,
 971                            "Failed to select rate control algorithm\n");
 972                 return -ENOENT;
 973         }
 974
 975         WARN_ON(local->rate_ctrl);
 976         local->rate_ctrl = ref;
 977
 978         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 979                     ref->ops->name);
 980
 981         return 0;
 982 }
 983
 984 void rate_control_deinitialize(struct ieee80211_local *local)
 985 {
 986         struct rate_control_ref *ref;
 987
 988         ref = local->rate_ctrl;
 989
 990         if (!ref)
 991                 return;
 992
 993         local->rate_ctrl = NULL;
 994         rate_control_free(local, ref);
 995 }