net/mac80211/rate.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
   5  * Copyright 2017       Intel Deutschland GmbH
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/rtnetlink.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include "rate.h"
  17 #include "ieee80211_i.h"
  18 #include "debugfs.h"
  19
  20 struct rate_control_alg {
  21         struct list_head list;
  22         const struct rate_control_ops *ops;
  23 };
  24
  25 static LIST_HEAD(rate_ctrl_algs);
  26 static DEFINE_MUTEX(rate_ctrl_mutex);
  27
  28 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  29 module_param(ieee80211_default_rc_algo, charp, 0644);
  30 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  31                  "Default rate control algorithm for mac80211 to use");
  32
  33 void rate_control_rate_init(struct sta_info *sta)
  34 {
  35         struct ieee80211_local *local = sta->sdata->local;
  36         struct rate_control_ref *ref = sta->rate_ctrl;
  37         struct ieee80211_sta *ista = &sta->sta;
  38         void *priv_sta = sta->rate_ctrl_priv;
  39         struct ieee80211_supported_band *sband;
  40         struct ieee80211_chanctx_conf *chanctx_conf;
  41
  42         ieee80211_sta_set_rx_nss(sta);
  43
  44         if (!ref)
  45                 return;
  46
  47         rcu_read_lock();
  48
  49         chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  50         if (WARN_ON(!chanctx_conf)) {
  51                 rcu_read_unlock();
  52                 return;
  53         }
  54
  55         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  56
  57         spin_lock_bh(&sta->rate_ctrl_lock);
  58         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  59                             priv_sta);
  60         spin_unlock_bh(&sta->rate_ctrl_lock);
  61         rcu_read_unlock();
  62         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  63 }
  64
  65 void rate_control_tx_status(struct ieee80211_local *local,
  66                             struct ieee80211_supported_band *sband,
  67                             struct ieee80211_tx_status *st)
  68 {
  69         struct rate_control_ref *ref = local->rate_ctrl;
  70         struct sta_info *sta = container_of(st->sta, struct sta_info, sta);
  71         void *priv_sta = sta->rate_ctrl_priv;
  72
  73         if (!ref || !test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
  74                 return;
  75
  76         spin_lock_bh(&sta->rate_ctrl_lock);
  77         if (ref->ops->tx_status_ext)
  78                 ref->ops->tx_status_ext(ref->priv, sband, priv_sta, st);
  79         else if (st->skb)
  80                 ref->ops->tx_status(ref->priv, sband, st->sta, priv_sta, st->skb);
  81         else
  82                 WARN_ON_ONCE(1);
  83
  84         spin_unlock_bh(&sta->rate_ctrl_lock);
  85 }
  86
  87 void rate_control_rate_update(struct ieee80211_local *local,
  88                                     struct ieee80211_supported_band *sband,
  89                                     struct sta_info *sta, u32 changed)
  90 {
  91         struct rate_control_ref *ref = local->rate_ctrl;
  92         struct ieee80211_sta *ista = &sta->sta;
  93         void *priv_sta = sta->rate_ctrl_priv;
  94         struct ieee80211_chanctx_conf *chanctx_conf;
  95
  96         if (ref && ref->ops->rate_update) {
  97                 rcu_read_lock();
  98
  99                 chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
 100                 if (WARN_ON(!chanctx_conf)) {
 101                         rcu_read_unlock();
 102                         return;
 103                 }
 104
 105                 spin_lock_bh(&sta->rate_ctrl_lock);
 106                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
 107                                       ista, priv_sta, changed);
 108                 spin_unlock_bh(&sta->rate_ctrl_lock);
 109                 rcu_read_unlock();
 110         }
 111         drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
 112 }
 113
 114 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
 115 {
 116         struct rate_control_alg *alg;
 117
 118         if (!ops->name)
 119                 return -EINVAL;
 120
 121         mutex_lock(&rate_ctrl_mutex);
 122         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 123                 if (!strcmp(alg->ops->name, ops->name)) {
 124                         /* don't register an algorithm twice */
 125                         WARN_ON(1);
 126                         mutex_unlock(&rate_ctrl_mutex);
 127                         return -EALREADY;
 128                 }
 129         }
 130
 131         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 132         if (alg == NULL) {
 133                 mutex_unlock(&rate_ctrl_mutex);
 134                 return -ENOMEM;
 135         }
 136         alg->ops = ops;
 137
 138         list_add_tail(&alg->list, &rate_ctrl_algs);
 139         mutex_unlock(&rate_ctrl_mutex);
 140
 141         return 0;
 142 }
 143 EXPORT_SYMBOL(ieee80211_rate_control_register);
 144
 145 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 146 {
 147         struct rate_control_alg *alg;
 148
 149         mutex_lock(&rate_ctrl_mutex);
 150         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 151                 if (alg->ops == ops) {
 152                         list_del(&alg->list);
 153                         kfree(alg);
 154                         break;
 155                 }
 156         }
 157         mutex_unlock(&rate_ctrl_mutex);
 158 }
 159 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 160
 161 static const struct rate_control_ops *
 162 ieee80211_try_rate_control_ops_get(const char *name)
 163 {
 164         struct rate_control_alg *alg;
 165         const struct rate_control_ops *ops = NULL;
 166
 167         if (!name)
 168                 return NULL;
 169
 170         mutex_lock(&rate_ctrl_mutex);
 171         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 172                 if (!strcmp(alg->ops->name, name)) {
 173                         ops = alg->ops;
 174                         break;
 175                 }
 176         }
 177         mutex_unlock(&rate_ctrl_mutex);
 178         return ops;
 179 }
 180
 181 /* Get the rate control algorithm. */
 182 static const struct rate_control_ops *
 183 ieee80211_rate_control_ops_get(const char *name)
 184 {
 185         const struct rate_control_ops *ops;
 186         const char *alg_name;
 187
 188         kernel_param_lock(THIS_MODULE);
 189         if (!name)
 190                 alg_name = ieee80211_default_rc_algo;
 191         else
 192                 alg_name = name;
 193
 194         ops = ieee80211_try_rate_control_ops_get(alg_name);
 195         if (!ops && name)
 196                 /* try default if specific alg requested but not found */
 197                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 198
 199         /* Note: check for > 0 is intentional to avoid clang warning */
 200         if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
 201                 /* try built-in one if specific alg requested but not found */
 202                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 203
 204         kernel_param_unlock(THIS_MODULE);
 205
 206         return ops;
 207 }
 208
 209 #ifdef CONFIG_MAC80211_DEBUGFS
 210 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 211                            size_t count, loff_t *ppos)
 212 {
 213         struct rate_control_ref *ref = file->private_data;
 214         int len = strlen(ref->ops->name);
 215
 216         return simple_read_from_buffer(userbuf, count, ppos,
 217                                        ref->ops->name, len);
 218 }
 219
 220 static const struct file_operations rcname_ops = {
 221         .read = rcname_read,
 222         .open = simple_open,
 223         .llseek = default_llseek,
 224 };
 225 #endif
 226
 227 static struct rate_control_ref *rate_control_alloc(const char *name,
 228                                             struct ieee80211_local *local)
 229 {
 230         struct dentry *debugfsdir = NULL;
 231         struct rate_control_ref *ref;
 232
 233         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 234         if (!ref)
 235                 return NULL;
 236         ref->ops = ieee80211_rate_control_ops_get(name);
 237         if (!ref->ops)
 238                 goto free;
 239
 240 #ifdef CONFIG_MAC80211_DEBUGFS
 241         debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
 242         local->debugfs.rcdir = debugfsdir;
 243         debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
 244 #endif
 245
 246         ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
 247         if (!ref->priv)
 248                 goto free;
 249         return ref;
 250
 251 free:
 252         kfree(ref);
 253         return NULL;
 254 }
 255
 256 static void rate_control_free(struct ieee80211_local *local,
 257                               struct rate_control_ref *ctrl_ref)
 258 {
 259         ctrl_ref->ops->free(ctrl_ref->priv);
 260
 261 #ifdef CONFIG_MAC80211_DEBUGFS
 262         debugfs_remove_recursive(local->debugfs.rcdir);
 263         local->debugfs.rcdir = NULL;
 264 #endif
 265
 266         kfree(ctrl_ref);
 267 }
 268
 269 void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata)
 270 {
 271         struct ieee80211_local *local = sdata->local;
 272         struct ieee80211_supported_band *sband;
 273         u32 user_mask, basic_rates = sdata->vif.bss_conf.basic_rates;
 274         enum nl80211_band band;
 275
 276         if (WARN_ON(!sdata->vif.bss_conf.chandef.chan))
 277                 return;
 278
 279         if (WARN_ON_ONCE(!basic_rates))
 280                 return;
 281
 282         band = sdata->vif.bss_conf.chandef.chan->band;
 283         user_mask = sdata->rc_rateidx_mask[band];
 284         sband = local->hw.wiphy->bands[band];
 285
 286         if (user_mask & basic_rates)
 287                 return;
 288
 289         sdata_dbg(sdata,
 290                   "no overlap between basic rates (0x%x) and user mask (0x%x on band %d) - clearing the latter",
 291                   basic_rates, user_mask, band);
 292         sdata->rc_rateidx_mask[band] = (1 << sband->n_bitrates) - 1;
 293 }
 294
 295 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 296 {
 297         struct sk_buff *skb = txrc->skb;
 298         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 299         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 300         __le16 fc;
 301
 302         fc = hdr->frame_control;
 303
 304         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 305                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 306                 !ieee80211_is_data(fc);
 307 }
 308
 309 static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
 310                                   struct ieee80211_supported_band *sband)
 311 {
 312         u8 i;
 313
 314         if (basic_rates == 0)
 315                 return; /* assume basic rates unknown and accept rate */
 316         if (*idx < 0)
 317                 return;
 318         if (basic_rates & (1 << *idx))
 319                 return; /* selected rate is a basic rate */
 320
 321         for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 322                 if (basic_rates & (1 << i)) {
 323                         *idx = i;
 324                         return;
 325                 }
 326         }
 327
 328         /* could not find a basic rate; use original selection */
 329 }
 330
 331 static void __rate_control_send_low(struct ieee80211_hw *hw,
 332                                     struct ieee80211_supported_band *sband,
 333                                     struct ieee80211_sta *sta,
 334                                     struct ieee80211_tx_info *info,
 335                                     u32 rate_mask)
 336 {
 337         int i;
 338         u32 rate_flags =
 339                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 340
 341         if ((sband->band == NL80211_BAND_2GHZ) &&
 342             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 343                 rate_flags |= IEEE80211_RATE_ERP_G;
 344
 345         info->control.rates[0].idx = 0;
 346         for (i = 0; i < sband->n_bitrates; i++) {
 347                 if (!(rate_mask & BIT(i)))
 348                         continue;
 349
 350                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 351                         continue;
 352
 353                 if (!rate_supported(sta, sband->band, i))
 354                         continue;
 355
 356                 info->control.rates[0].idx = i;
 357                 break;
 358         }
 359         WARN_ONCE(i == sband->n_bitrates,
 360                   "no supported rates (0x%x) in rate_mask 0x%x with flags 0x%x\n",
 361                   sta ? sta->supp_rates[sband->band] : -1,
 362                   rate_mask, rate_flags);
 363
 364         info->control.rates[0].count =
 365                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 366                 1 : hw->max_rate_tries;
 367
 368         info->control.skip_table = 1;
 369 }
 370
 371
 372 bool rate_control_send_low(struct ieee80211_sta *pubsta,
 373                            void *priv_sta,
 374                            struct ieee80211_tx_rate_control *txrc)
 375 {
 376         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 377         struct ieee80211_supported_band *sband = txrc->sband;
 378         struct sta_info *sta;
 379         int mcast_rate;
 380         bool use_basicrate = false;
 381
 382         if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
 383                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 384                                         txrc->rate_idx_mask);
 385
 386                 if (!pubsta && txrc->bss) {
 387                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 388                         if (mcast_rate > 0) {
 389                                 info->control.rates[0].idx = mcast_rate - 1;
 390                                 return true;
 391                         }
 392                         use_basicrate = true;
 393                 } else if (pubsta) {
 394                         sta = container_of(pubsta, struct sta_info, sta);
 395                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 396                                 use_basicrate = true;
 397                 }
 398
 399                 if (use_basicrate)
 400                         rc_send_low_basicrate(&info->control.rates[0].idx,
 401                                               txrc->bss_conf->basic_rates,
 402                                               sband);
 403
 404                 return true;
 405         }
 406         return false;
 407 }
 408 EXPORT_SYMBOL(rate_control_send_low);
 409
 410 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 411 {
 412         int j;
 413
 414         /* See whether the selected rate or anything below it is allowed. */
 415         for (j = *rate_idx; j >= 0; j--) {
 416                 if (mask & (1 << j)) {
 417                         /* Okay, found a suitable rate. Use it. */
 418                         *rate_idx = j;
 419                         return true;
 420                 }
 421         }
 422
 423         /* Try to find a higher rate that would be allowed */
 424         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 425                 if (mask & (1 << j)) {
 426                         /* Okay, found a suitable rate. Use it. */
 427                         *rate_idx = j;
 428                         return true;
 429                 }
 430         }
 431         return false;
 432 }
 433
 434 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 435 {
 436         int i, j;
 437         int ridx, rbit;
 438
 439         ridx = *rate_idx / 8;
 440         rbit = *rate_idx % 8;
 441
 442         /* sanity check */
 443         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 444                 return false;
 445
 446         /* See whether the selected rate or anything below it is allowed. */
 447         for (i = ridx; i >= 0; i--) {
 448                 for (j = rbit; j >= 0; j--)
 449                         if (mcs_mask[i] & BIT(j)) {
 450                                 *rate_idx = i * 8 + j;
 451                                 return true;
 452                         }
 453                 rbit = 7;
 454         }
 455
 456         /* Try to find a higher rate that would be allowed */
 457         ridx = (*rate_idx + 1) / 8;
 458         rbit = (*rate_idx + 1) % 8;
 459
 460         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 461                 for (j = rbit; j < 8; j++)
 462                         if (mcs_mask[i] & BIT(j)) {
 463                                 *rate_idx = i * 8 + j;
 464                                 return true;
 465                         }
 466                 rbit = 0;
 467         }
 468         return false;
 469 }
 470
 471 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 472 {
 473         int i, j;
 474         int ridx, rbit;
 475
 476         ridx = *rate_idx >> 4;
 477         rbit = *rate_idx & 0xf;
 478
 479         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 480                 return false;
 481
 482         /* See whether the selected rate or anything below it is allowed. */
 483         for (i = ridx; i >= 0; i--) {
 484                 for (j = rbit; j >= 0; j--) {
 485                         if (vht_mask[i] & BIT(j)) {
 486                                 *rate_idx = (i << 4) | j;
 487                                 return true;
 488                         }
 489                 }
 490                 rbit = 15;
 491         }
 492
 493         /* Try to find a higher rate that would be allowed */
 494         ridx = (*rate_idx + 1) >> 4;
 495         rbit = (*rate_idx + 1) & 0xf;
 496
 497         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 498                 for (j = rbit; j < 16; j++) {
 499                         if (vht_mask[i] & BIT(j)) {
 500                                 *rate_idx = (i << 4) | j;
 501                                 return true;
 502                         }
 503                 }
 504                 rbit = 0;
 505         }
 506         return false;
 507 }
 508
 509 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 510                                 struct ieee80211_supported_band *sband,
 511                                 enum nl80211_chan_width chan_width,
 512                                 u32 mask,
 513                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 514                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 515 {
 516         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 517                 /* handle VHT rates */
 518                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 519                         return;
 520
 521                 *rate_idx = 0;
 522                 /* keep protection flags */
 523                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 524                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 525                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 526
 527                 *rate_flags |= IEEE80211_TX_RC_MCS;
 528                 if (chan_width == NL80211_CHAN_WIDTH_40)
 529                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 530
 531                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 532                         return;
 533
 534                 /* also try the legacy rates. */
 535                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 536                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 537                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 538                                                mask))
 539                         return;
 540         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 541                 /* handle HT rates */
 542                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 543                         return;
 544
 545                 /* also try the legacy rates. */
 546                 *rate_idx = 0;
 547                 /* keep protection flags */
 548                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 549                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 550                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 551                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 552                                                mask))
 553                         return;
 554         } else {
 555                 /* handle legacy rates */
 556                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 557                                                mask))
 558                         return;
 559
 560                 /* if HT BSS, and we handle a data frame, also try HT rates */
 561                 switch (chan_width) {
 562                 case NL80211_CHAN_WIDTH_20_NOHT:
 563                 case NL80211_CHAN_WIDTH_5:
 564                 case NL80211_CHAN_WIDTH_10:
 565                         return;
 566                 default:
 567                         break;
 568                 }
 569
 570                 *rate_idx = 0;
 571                 /* keep protection flags */
 572                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 573                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 574                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 575
 576                 *rate_flags |= IEEE80211_TX_RC_MCS;
 577
 578                 if (chan_width == NL80211_CHAN_WIDTH_40)
 579                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 580
 581                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 582                         return;
 583         }
 584
 585         /*
 586          * Uh.. No suitable rate exists. This should not really happen with
 587          * sane TX rate mask configurations. However, should someone manage to
 588          * configure supported rates and TX rate mask in incompatible way,
 589          * allow the frame to be transmitted with whatever the rate control
 590          * selected.
 591          */
 592 }
 593
 594 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 595                                 struct ieee80211_supported_band *sband,
 596                                 struct ieee80211_tx_info *info,
 597                                 struct ieee80211_tx_rate *rates,
 598                                 int max_rates)
 599 {
 600         struct ieee80211_rate *rate;
 601         bool inval = false;
 602         int i;
 603
 604         /*
 605          * Set up the RTS/CTS rate as the fastest basic rate
 606          * that is not faster than the data rate unless there
 607          * is no basic rate slower than the data rate, in which
 608          * case we pick the slowest basic rate
 609          *
 610          * XXX: Should this check all retry rates?
 611          */
 612         if (!(rates[0].flags &
 613               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 614                 u32 basic_rates = vif->bss_conf.basic_rates;
 615                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 616
 617                 rate = &sband->bitrates[rates[0].idx];
 618
 619                 for (i = 0; i < sband->n_bitrates; i++) {
 620                         /* must be a basic rate */
 621                         if (!(basic_rates & BIT(i)))
 622                                 continue;
 623                         /* must not be faster than the data rate */
 624                         if (sband->bitrates[i].bitrate > rate->bitrate)
 625                                 continue;
 626                         /* maximum */
 627                         if (sband->bitrates[baserate].bitrate <
 628                              sband->bitrates[i].bitrate)
 629                                 baserate = i;
 630                 }
 631
 632                 info->control.rts_cts_rate_idx = baserate;
 633         }
 634
 635         for (i = 0; i < max_rates; i++) {
 636                 /*
 637                  * make sure there's no valid rate following
 638                  * an invalid one, just in case drivers don't
 639                  * take the API seriously to stop at -1.
 640                  */
 641                 if (inval) {
 642                         rates[i].idx = -1;
 643                         continue;
 644                 }
 645                 if (rates[i].idx < 0) {
 646                         inval = true;
 647                         continue;
 648                 }
 649
 650                 /*
 651                  * For now assume MCS is already set up correctly, this
 652                  * needs to be fixed.
 653                  */
 654                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 655                         WARN_ON(rates[i].idx > 76);
 656
 657                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 658                             info->control.use_cts_prot)
 659                                 rates[i].flags |=
 660                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 661                         continue;
 662                 }
 663
 664                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 665                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 666                         continue;
 667                 }
 668
 669                 /* set up RTS protection if desired */
 670                 if (info->control.use_rts) {
 671                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 672                         info->control.use_cts_prot = false;
 673                 }
 674
 675                 /* RC is busted */
 676                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 677                         rates[i].idx = -1;
 678                         continue;
 679                 }
 680
 681                 rate = &sband->bitrates[rates[i].idx];
 682
 683                 /* set up short preamble */
 684                 if (info->control.short_preamble &&
 685                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 686                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 687
 688                 /* set up G protection */
 689                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 690                     info->control.use_cts_prot &&
 691                     rate->flags & IEEE80211_RATE_ERP_G)
 692                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 693         }
 694 }
 695
 696
 697 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 698                                         struct ieee80211_tx_info *info,
 699                                         struct ieee80211_tx_rate *rates,
 700                                         int max_rates)
 701 {
 702         struct ieee80211_sta_rates *ratetbl = NULL;
 703         int i;
 704
 705         if (sta && !info->control.skip_table)
 706                 ratetbl = rcu_dereference(sta->rates);
 707
 708         /* Fill remaining rate slots with data from the sta rate table. */
 709         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 710         for (i = 0; i < max_rates; i++) {
 711                 if (i < ARRAY_SIZE(info->control.rates) &&
 712                     info->control.rates[i].idx >= 0 &&
 713                     info->control.rates[i].count) {
 714                         if (rates != info->control.rates)
 715                                 rates[i] = info->control.rates[i];
 716                 } else if (ratetbl) {
 717                         rates[i].idx = ratetbl->rate[i].idx;
 718                         rates[i].flags = ratetbl->rate[i].flags;
 719                         if (info->control.use_rts)
 720                                 rates[i].count = ratetbl->rate[i].count_rts;
 721                         else if (info->control.use_cts_prot)
 722                                 rates[i].count = ratetbl->rate[i].count_cts;
 723                         else
 724                                 rates[i].count = ratetbl->rate[i].count;
 725                 } else {
 726                         rates[i].idx = -1;
 727                         rates[i].count = 0;
 728                 }
 729
 730                 if (rates[i].idx < 0 || !rates[i].count)
 731                         break;
 732         }
 733 }
 734
 735 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 736                                   struct ieee80211_supported_band *sband,
 737                                   struct ieee80211_sta *sta, u32 *mask,
 738                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 739                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 740 {
 741         u32 i, flags;
 742
 743         *mask = sdata->rc_rateidx_mask[sband->band];
 744         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 745         for (i = 0; i < sband->n_bitrates; i++) {
 746                 if ((flags & sband->bitrates[i].flags) != flags)
 747                         *mask &= ~BIT(i);
 748         }
 749
 750         if (*mask == (1 << sband->n_bitrates) - 1 &&
 751             !sdata->rc_has_mcs_mask[sband->band] &&
 752             !sdata->rc_has_vht_mcs_mask[sband->band])
 753                 return false;
 754
 755         if (sdata->rc_has_mcs_mask[sband->band])
 756                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 757                        IEEE80211_HT_MCS_MASK_LEN);
 758         else
 759                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 760
 761         if (sdata->rc_has_vht_mcs_mask[sband->band])
 762                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 763                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 764         else
 765                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 766
 767         if (sta) {
 768                 __le16 sta_vht_cap;
 769                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 770
 771                 /* Filter out rates that the STA does not support */
 772                 *mask &= sta->supp_rates[sband->band];
 773                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 774                         mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 775
 776                 sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
 777                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 778                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 779                         vht_mask[i] &= sta_vht_mask[i];
 780         }
 781
 782         return true;
 783 }
 784
 785 static void
 786 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 787                                 struct ieee80211_supported_band *sband,
 788                                 struct ieee80211_sta_rates *rates)
 789 {
 790         int i;
 791         u32 mask;
 792         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 793         u16 vht_mask[NL80211_VHT_NSS_MAX];
 794         enum nl80211_chan_width chan_width;
 795
 796         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 797                                    mcs_mask, vht_mask))
 798                 return;
 799
 800         chan_width = sta->sdata->vif.bss_conf.chandef.width;
 801         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 802                 if (rates->rate[i].idx < 0)
 803                         break;
 804
 805                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 806                                     sband, chan_width, mask, mcs_mask,
 807                                     vht_mask);
 808         }
 809 }
 810
 811 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 812                                     struct ieee80211_sta *sta,
 813                                     struct ieee80211_supported_band *sband,
 814                                     struct ieee80211_tx_rate *rates,
 815                                     int max_rates)
 816 {
 817         enum nl80211_chan_width chan_width;
 818         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 819         u32 mask;
 820         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 821         int i;
 822
 823         /*
 824          * Try to enforce the rateidx mask the user wanted. skip this if the
 825          * default mask (allow all rates) is used to save some processing for
 826          * the common case.
 827          */
 828         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 829                                    vht_mask))
 830                 return;
 831
 832         /*
 833          * Make sure the rate index selected for each TX rate is
 834          * included in the configured mask and change the rate indexes
 835          * if needed.
 836          */
 837         chan_width = sdata->vif.bss_conf.chandef.width;
 838         for (i = 0; i < max_rates; i++) {
 839                 /* Skip invalid rates */
 840                 if (rates[i].idx < 0)
 841                         break;
 842
 843                 rate_flags = rates[i].flags;
 844                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 845                                     chan_width, mask, mcs_mask, vht_mask);
 846                 rates[i].flags = rate_flags;
 847         }
 848 }
 849
 850 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 851                             struct ieee80211_sta *sta,
 852                             struct sk_buff *skb,
 853                             struct ieee80211_tx_rate *dest,
 854                             int max_rates)
 855 {
 856         struct ieee80211_sub_if_data *sdata;
 857         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 858         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 859         struct ieee80211_supported_band *sband;
 860
 861         rate_control_fill_sta_table(sta, info, dest, max_rates);
 862
 863         if (!vif)
 864                 return;
 865
 866         sdata = vif_to_sdata(vif);
 867         sband = sdata->local->hw.wiphy->bands[info->band];
 868
 869         if (ieee80211_is_data(hdr->frame_control))
 870                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 871
 872         if (dest[0].idx < 0)
 873                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 874                                         sdata->rc_rateidx_mask[info->band]);
 875
 876         if (sta)
 877                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 878 }
 879 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 880
 881 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 882                            struct sta_info *sta,
 883                            struct ieee80211_tx_rate_control *txrc)
 884 {
 885         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 886         void *priv_sta = NULL;
 887         struct ieee80211_sta *ista = NULL;
 888         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 889         int i;
 890
 891         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 892                 ista = &sta->sta;
 893                 priv_sta = sta->rate_ctrl_priv;
 894         }
 895
 896         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 897                 info->control.rates[i].idx = -1;
 898                 info->control.rates[i].flags = 0;
 899                 info->control.rates[i].count = 0;
 900         }
 901
 902         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 903                 return;
 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                 ref->ops->get_rate(ref->priv, NULL, 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 }