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  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/rtnetlink.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include "rate.h"
  16 #include "ieee80211_i.h"
  17 #include "debugfs.h"
  18
  19 struct rate_control_alg {
  20         struct list_head list;
  21         const struct rate_control_ops *ops;
  22 };
  23
  24 static LIST_HEAD(rate_ctrl_algs);
  25 static DEFINE_MUTEX(rate_ctrl_mutex);
  26
  27 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
  28 module_param(ieee80211_default_rc_algo, charp, 0644);
  29 MODULE_PARM_DESC(ieee80211_default_rc_algo,
  30                  "Default rate control algorithm for mac80211 to use");
  31
  32 void rate_control_rate_init(struct sta_info *sta)
  33 {
  34         struct ieee80211_local *local = sta->sdata->local;
  35         struct rate_control_ref *ref = sta->rate_ctrl;
  36         struct ieee80211_sta *ista = &sta->sta;
  37         void *priv_sta = sta->rate_ctrl_priv;
  38         struct ieee80211_supported_band *sband;
  39         struct ieee80211_chanctx_conf *chanctx_conf;
  40
  41         ieee80211_sta_set_rx_nss(sta);
  42
  43         if (!ref)
  44                 return;
  45
  46         rcu_read_lock();
  47
  48         chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  49         if (WARN_ON(!chanctx_conf)) {
  50                 rcu_read_unlock();
  51                 return;
  52         }
  53
  54         sband = local->hw.wiphy->bands[chanctx_conf->def.chan->band];
  55
  56         spin_lock_bh(&sta->rate_ctrl_lock);
  57         ref->ops->rate_init(ref->priv, sband, &chanctx_conf->def, ista,
  58                             priv_sta);
  59         spin_unlock_bh(&sta->rate_ctrl_lock);
  60         rcu_read_unlock();
  61         set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
  62 }
  63
  64 void rate_control_rate_update(struct ieee80211_local *local,
  65                                     struct ieee80211_supported_band *sband,
  66                                     struct sta_info *sta, u32 changed)
  67 {
  68         struct rate_control_ref *ref = local->rate_ctrl;
  69         struct ieee80211_sta *ista = &sta->sta;
  70         void *priv_sta = sta->rate_ctrl_priv;
  71         struct ieee80211_chanctx_conf *chanctx_conf;
  72
  73         if (ref && ref->ops->rate_update) {
  74                 rcu_read_lock();
  75
  76                 chanctx_conf = rcu_dereference(sta->sdata->vif.chanctx_conf);
  77                 if (WARN_ON(!chanctx_conf)) {
  78                         rcu_read_unlock();
  79                         return;
  80                 }
  81
  82                 spin_lock_bh(&sta->rate_ctrl_lock);
  83                 ref->ops->rate_update(ref->priv, sband, &chanctx_conf->def,
  84                                       ista, priv_sta, changed);
  85                 spin_unlock_bh(&sta->rate_ctrl_lock);
  86                 rcu_read_unlock();
  87         }
  88         drv_sta_rc_update(local, sta->sdata, &sta->sta, changed);
  89 }
  90
  91 int ieee80211_rate_control_register(const struct rate_control_ops *ops)
  92 {
  93         struct rate_control_alg *alg;
  94
  95         if (!ops->name)
  96                 return -EINVAL;
  97
  98         mutex_lock(&rate_ctrl_mutex);
  99         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 100                 if (!strcmp(alg->ops->name, ops->name)) {
 101                         /* don't register an algorithm twice */
 102                         WARN_ON(1);
 103                         mutex_unlock(&rate_ctrl_mutex);
 104                         return -EALREADY;
 105                 }
 106         }
 107
 108         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 109         if (alg == NULL) {
 110                 mutex_unlock(&rate_ctrl_mutex);
 111                 return -ENOMEM;
 112         }
 113         alg->ops = ops;
 114
 115         list_add_tail(&alg->list, &rate_ctrl_algs);
 116         mutex_unlock(&rate_ctrl_mutex);
 117
 118         return 0;
 119 }
 120 EXPORT_SYMBOL(ieee80211_rate_control_register);
 121
 122 void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
 123 {
 124         struct rate_control_alg *alg;
 125
 126         mutex_lock(&rate_ctrl_mutex);
 127         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 128                 if (alg->ops == ops) {
 129                         list_del(&alg->list);
 130                         kfree(alg);
 131                         break;
 132                 }
 133         }
 134         mutex_unlock(&rate_ctrl_mutex);
 135 }
 136 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
 137
 138 static const struct rate_control_ops *
 139 ieee80211_try_rate_control_ops_get(const char *name)
 140 {
 141         struct rate_control_alg *alg;
 142         const struct rate_control_ops *ops = NULL;
 143
 144         if (!name)
 145                 return NULL;
 146
 147         mutex_lock(&rate_ctrl_mutex);
 148         list_for_each_entry(alg, &rate_ctrl_algs, list) {
 149                 if (!strcmp(alg->ops->name, name)) {
 150                         ops = alg->ops;
 151                         break;
 152                 }
 153         }
 154         mutex_unlock(&rate_ctrl_mutex);
 155         return ops;
 156 }
 157
 158 /* Get the rate control algorithm. */
 159 static const struct rate_control_ops *
 160 ieee80211_rate_control_ops_get(const char *name)
 161 {
 162         const struct rate_control_ops *ops;
 163         const char *alg_name;
 164
 165         kernel_param_lock(THIS_MODULE);
 166         if (!name)
 167                 alg_name = ieee80211_default_rc_algo;
 168         else
 169                 alg_name = name;
 170
 171         ops = ieee80211_try_rate_control_ops_get(alg_name);
 172         if (!ops && name)
 173                 /* try default if specific alg requested but not found */
 174                 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 175
 176         /* try built-in one if specific alg requested but not found */
 177         if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
 178                 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 179         kernel_param_unlock(THIS_MODULE);
 180
 181         return ops;
 182 }
 183
 184 #ifdef CONFIG_MAC80211_DEBUGFS
 185 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 186                            size_t count, loff_t *ppos)
 187 {
 188         struct rate_control_ref *ref = file->private_data;
 189         int len = strlen(ref->ops->name);
 190
 191         return simple_read_from_buffer(userbuf, count, ppos,
 192                                        ref->ops->name, len);
 193 }
 194
 195 static const struct file_operations rcname_ops = {
 196         .read = rcname_read,
 197         .open = simple_open,
 198         .llseek = default_llseek,
 199 };
 200 #endif
 201
 202 static struct rate_control_ref *rate_control_alloc(const char *name,
 203                                             struct ieee80211_local *local)
 204 {
 205         struct dentry *debugfsdir = NULL;
 206         struct rate_control_ref *ref;
 207
 208         ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 209         if (!ref)
 210                 return NULL;
 211         ref->local = local;
 212         ref->ops = ieee80211_rate_control_ops_get(name);
 213         if (!ref->ops)
 214                 goto free;
 215
 216 #ifdef CONFIG_MAC80211_DEBUGFS
 217         debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
 218         local->debugfs.rcdir = debugfsdir;
 219         debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
 220 #endif
 221
 222         ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
 223         if (!ref->priv)
 224                 goto free;
 225         return ref;
 226
 227 free:
 228         kfree(ref);
 229         return NULL;
 230 }
 231
 232 static void rate_control_free(struct rate_control_ref *ctrl_ref)
 233 {
 234         ctrl_ref->ops->free(ctrl_ref->priv);
 235
 236 #ifdef CONFIG_MAC80211_DEBUGFS
 237         debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
 238         ctrl_ref->local->debugfs.rcdir = NULL;
 239 #endif
 240
 241         kfree(ctrl_ref);
 242 }
 243
 244 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 245 {
 246         struct sk_buff *skb = txrc->skb;
 247         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 248         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 249         __le16 fc;
 250
 251         fc = hdr->frame_control;
 252
 253         return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 254                                IEEE80211_TX_CTL_USE_MINRATE)) ||
 255                 !ieee80211_is_data(fc);
 256 }
 257
 258 static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
 259                                   struct ieee80211_supported_band *sband)
 260 {
 261         u8 i;
 262
 263         if (basic_rates == 0)
 264                 return; /* assume basic rates unknown and accept rate */
 265         if (*idx < 0)
 266                 return;
 267         if (basic_rates & (1 << *idx))
 268                 return; /* selected rate is a basic rate */
 269
 270         for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 271                 if (basic_rates & (1 << i)) {
 272                         *idx = i;
 273                         return;
 274                 }
 275         }
 276
 277         /* could not find a basic rate; use original selection */
 278 }
 279
 280 static void __rate_control_send_low(struct ieee80211_hw *hw,
 281                                     struct ieee80211_supported_band *sband,
 282                                     struct ieee80211_sta *sta,
 283                                     struct ieee80211_tx_info *info,
 284                                     u32 rate_mask)
 285 {
 286         int i;
 287         u32 rate_flags =
 288                 ieee80211_chandef_rate_flags(&hw->conf.chandef);
 289
 290         if ((sband->band == IEEE80211_BAND_2GHZ) &&
 291             (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 292                 rate_flags |= IEEE80211_RATE_ERP_G;
 293
 294         info->control.rates[0].idx = 0;
 295         for (i = 0; i < sband->n_bitrates; i++) {
 296                 if (!(rate_mask & BIT(i)))
 297                         continue;
 298
 299                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
 300                         continue;
 301
 302                 if (!rate_supported(sta, sband->band, i))
 303                         continue;
 304
 305                 info->control.rates[0].idx = i;
 306                 break;
 307         }
 308         WARN_ONCE(i == sband->n_bitrates,
 309                   "no supported rates (0x%x) in rate_mask 0x%x with flags 0x%x\n",
 310                   sta ? sta->supp_rates[sband->band] : -1,
 311                   rate_mask, rate_flags);
 312
 313         info->control.rates[0].count =
 314                 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 315                 1 : hw->max_rate_tries;
 316
 317         info->control.skip_table = 1;
 318 }
 319
 320
 321 bool rate_control_send_low(struct ieee80211_sta *pubsta,
 322                            void *priv_sta,
 323                            struct ieee80211_tx_rate_control *txrc)
 324 {
 325         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 326         struct ieee80211_supported_band *sband = txrc->sband;
 327         struct sta_info *sta;
 328         int mcast_rate;
 329         bool use_basicrate = false;
 330
 331         if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
 332                 __rate_control_send_low(txrc->hw, sband, pubsta, info,
 333                                         txrc->rate_idx_mask);
 334
 335                 if (!pubsta && txrc->bss) {
 336                         mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 337                         if (mcast_rate > 0) {
 338                                 info->control.rates[0].idx = mcast_rate - 1;
 339                                 return true;
 340                         }
 341                         use_basicrate = true;
 342                 } else if (pubsta) {
 343                         sta = container_of(pubsta, struct sta_info, sta);
 344                         if (ieee80211_vif_is_mesh(&sta->sdata->vif))
 345                                 use_basicrate = true;
 346                 }
 347
 348                 if (use_basicrate)
 349                         rc_send_low_basicrate(&info->control.rates[0].idx,
 350                                               txrc->bss_conf->basic_rates,
 351                                               sband);
 352
 353                 return true;
 354         }
 355         return false;
 356 }
 357 EXPORT_SYMBOL(rate_control_send_low);
 358
 359 static bool rate_idx_match_legacy_mask(s8 *rate_idx, int n_bitrates, u32 mask)
 360 {
 361         int j;
 362
 363         /* See whether the selected rate or anything below it is allowed. */
 364         for (j = *rate_idx; j >= 0; j--) {
 365                 if (mask & (1 << j)) {
 366                         /* Okay, found a suitable rate. Use it. */
 367                         *rate_idx = j;
 368                         return true;
 369                 }
 370         }
 371
 372         /* Try to find a higher rate that would be allowed */
 373         for (j = *rate_idx + 1; j < n_bitrates; j++) {
 374                 if (mask & (1 << j)) {
 375                         /* Okay, found a suitable rate. Use it. */
 376                         *rate_idx = j;
 377                         return true;
 378                 }
 379         }
 380         return false;
 381 }
 382
 383 static bool rate_idx_match_mcs_mask(s8 *rate_idx, u8 *mcs_mask)
 384 {
 385         int i, j;
 386         int ridx, rbit;
 387
 388         ridx = *rate_idx / 8;
 389         rbit = *rate_idx % 8;
 390
 391         /* sanity check */
 392         if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 393                 return false;
 394
 395         /* See whether the selected rate or anything below it is allowed. */
 396         for (i = ridx; i >= 0; i--) {
 397                 for (j = rbit; j >= 0; j--)
 398                         if (mcs_mask[i] & BIT(j)) {
 399                                 *rate_idx = i * 8 + j;
 400                                 return true;
 401                         }
 402                 rbit = 7;
 403         }
 404
 405         /* Try to find a higher rate that would be allowed */
 406         ridx = (*rate_idx + 1) / 8;
 407         rbit = (*rate_idx + 1) % 8;
 408
 409         for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 410                 for (j = rbit; j < 8; j++)
 411                         if (mcs_mask[i] & BIT(j)) {
 412                                 *rate_idx = i * 8 + j;
 413                                 return true;
 414                         }
 415                 rbit = 0;
 416         }
 417         return false;
 418 }
 419
 420 static bool rate_idx_match_vht_mcs_mask(s8 *rate_idx, u16 *vht_mask)
 421 {
 422         int i, j;
 423         int ridx, rbit;
 424
 425         ridx = *rate_idx >> 4;
 426         rbit = *rate_idx & 0xf;
 427
 428         if (ridx < 0 || ridx >= NL80211_VHT_NSS_MAX)
 429                 return false;
 430
 431         /* See whether the selected rate or anything below it is allowed. */
 432         for (i = ridx; i >= 0; i--) {
 433                 for (j = rbit; j >= 0; j--) {
 434                         if (vht_mask[i] & BIT(j)) {
 435                                 *rate_idx = (i << 4) | j;
 436                                 return true;
 437                         }
 438                 }
 439                 rbit = 15;
 440         }
 441
 442         /* Try to find a higher rate that would be allowed */
 443         ridx = (*rate_idx + 1) >> 4;
 444         rbit = (*rate_idx + 1) & 0xf;
 445
 446         for (i = ridx; i < NL80211_VHT_NSS_MAX; i++) {
 447                 for (j = rbit; j < 16; j++) {
 448                         if (vht_mask[i] & BIT(j)) {
 449                                 *rate_idx = (i << 4) | j;
 450                                 return true;
 451                         }
 452                 }
 453                 rbit = 0;
 454         }
 455         return false;
 456 }
 457
 458 static void rate_idx_match_mask(s8 *rate_idx, u16 *rate_flags,
 459                                 struct ieee80211_supported_band *sband,
 460                                 enum nl80211_chan_width chan_width,
 461                                 u32 mask,
 462                                 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 463                                 u16 vht_mask[NL80211_VHT_NSS_MAX])
 464 {
 465         if (*rate_flags & IEEE80211_TX_RC_VHT_MCS) {
 466                 /* handle VHT rates */
 467                 if (rate_idx_match_vht_mcs_mask(rate_idx, vht_mask))
 468                         return;
 469
 470                 *rate_idx = 0;
 471                 /* keep protection flags */
 472                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 473                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 474                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 475
 476                 *rate_flags |= IEEE80211_TX_RC_MCS;
 477                 if (chan_width == NL80211_CHAN_WIDTH_40)
 478                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 479
 480                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 481                         return;
 482
 483                 /* also try the legacy rates. */
 484                 *rate_flags &= ~(IEEE80211_TX_RC_MCS |
 485                                  IEEE80211_TX_RC_40_MHZ_WIDTH);
 486                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 487                                                mask))
 488                         return;
 489         } else if (*rate_flags & IEEE80211_TX_RC_MCS) {
 490                 /* handle HT rates */
 491                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 492                         return;
 493
 494                 /* also try the legacy rates. */
 495                 *rate_idx = 0;
 496                 /* keep protection flags */
 497                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 498                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 499                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 500                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 501                                                mask))
 502                         return;
 503         } else {
 504                 /* handle legacy rates */
 505                 if (rate_idx_match_legacy_mask(rate_idx, sband->n_bitrates,
 506                                                mask))
 507                         return;
 508
 509                 /* if HT BSS, and we handle a data frame, also try HT rates */
 510                 switch (chan_width) {
 511                 case NL80211_CHAN_WIDTH_20_NOHT:
 512                 case NL80211_CHAN_WIDTH_5:
 513                 case NL80211_CHAN_WIDTH_10:
 514                         return;
 515                 default:
 516                         break;
 517                 }
 518
 519                 *rate_idx = 0;
 520                 /* keep protection flags */
 521                 *rate_flags &= (IEEE80211_TX_RC_USE_RTS_CTS |
 522                                 IEEE80211_TX_RC_USE_CTS_PROTECT |
 523                                 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 524
 525                 *rate_flags |= IEEE80211_TX_RC_MCS;
 526
 527                 if (chan_width == NL80211_CHAN_WIDTH_40)
 528                         *rate_flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
 529
 530                 if (rate_idx_match_mcs_mask(rate_idx, mcs_mask))
 531                         return;
 532         }
 533
 534         /*
 535          * Uh.. No suitable rate exists. This should not really happen with
 536          * sane TX rate mask configurations. However, should someone manage to
 537          * configure supported rates and TX rate mask in incompatible way,
 538          * allow the frame to be transmitted with whatever the rate control
 539          * selected.
 540          */
 541 }
 542
 543 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
 544                                 struct ieee80211_supported_band *sband,
 545                                 struct ieee80211_tx_info *info,
 546                                 struct ieee80211_tx_rate *rates,
 547                                 int max_rates)
 548 {
 549         struct ieee80211_rate *rate;
 550         bool inval = false;
 551         int i;
 552
 553         /*
 554          * Set up the RTS/CTS rate as the fastest basic rate
 555          * that is not faster than the data rate unless there
 556          * is no basic rate slower than the data rate, in which
 557          * case we pick the slowest basic rate
 558          *
 559          * XXX: Should this check all retry rates?
 560          */
 561         if (!(rates[0].flags &
 562               (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))) {
 563                 u32 basic_rates = vif->bss_conf.basic_rates;
 564                 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
 565
 566                 rate = &sband->bitrates[rates[0].idx];
 567
 568                 for (i = 0; i < sband->n_bitrates; i++) {
 569                         /* must be a basic rate */
 570                         if (!(basic_rates & BIT(i)))
 571                                 continue;
 572                         /* must not be faster than the data rate */
 573                         if (sband->bitrates[i].bitrate > rate->bitrate)
 574                                 continue;
 575                         /* maximum */
 576                         if (sband->bitrates[baserate].bitrate <
 577                              sband->bitrates[i].bitrate)
 578                                 baserate = i;
 579                 }
 580
 581                 info->control.rts_cts_rate_idx = baserate;
 582         }
 583
 584         for (i = 0; i < max_rates; i++) {
 585                 /*
 586                  * make sure there's no valid rate following
 587                  * an invalid one, just in case drivers don't
 588                  * take the API seriously to stop at -1.
 589                  */
 590                 if (inval) {
 591                         rates[i].idx = -1;
 592                         continue;
 593                 }
 594                 if (rates[i].idx < 0) {
 595                         inval = true;
 596                         continue;
 597                 }
 598
 599                 /*
 600                  * For now assume MCS is already set up correctly, this
 601                  * needs to be fixed.
 602                  */
 603                 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
 604                         WARN_ON(rates[i].idx > 76);
 605
 606                         if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 607                             info->control.use_cts_prot)
 608                                 rates[i].flags |=
 609                                         IEEE80211_TX_RC_USE_CTS_PROTECT;
 610                         continue;
 611                 }
 612
 613                 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
 614                         WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
 615                         continue;
 616                 }
 617
 618                 /* set up RTS protection if desired */
 619                 if (info->control.use_rts) {
 620                         rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
 621                         info->control.use_cts_prot = false;
 622                 }
 623
 624                 /* RC is busted */
 625                 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
 626                         rates[i].idx = -1;
 627                         continue;
 628                 }
 629
 630                 rate = &sband->bitrates[rates[i].idx];
 631
 632                 /* set up short preamble */
 633                 if (info->control.short_preamble &&
 634                     rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 635                         rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 636
 637                 /* set up G protection */
 638                 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
 639                     info->control.use_cts_prot &&
 640                     rate->flags & IEEE80211_RATE_ERP_G)
 641                         rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
 642         }
 643 }
 644
 645
 646 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
 647                                         struct ieee80211_tx_info *info,
 648                                         struct ieee80211_tx_rate *rates,
 649                                         int max_rates)
 650 {
 651         struct ieee80211_sta_rates *ratetbl = NULL;
 652         int i;
 653
 654         if (sta && !info->control.skip_table)
 655                 ratetbl = rcu_dereference(sta->rates);
 656
 657         /* Fill remaining rate slots with data from the sta rate table. */
 658         max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
 659         for (i = 0; i < max_rates; i++) {
 660                 if (i < ARRAY_SIZE(info->control.rates) &&
 661                     info->control.rates[i].idx >= 0 &&
 662                     info->control.rates[i].count) {
 663                         if (rates != info->control.rates)
 664                                 rates[i] = info->control.rates[i];
 665                 } else if (ratetbl) {
 666                         rates[i].idx = ratetbl->rate[i].idx;
 667                         rates[i].flags = ratetbl->rate[i].flags;
 668                         if (info->control.use_rts)
 669                                 rates[i].count = ratetbl->rate[i].count_rts;
 670                         else if (info->control.use_cts_prot)
 671                                 rates[i].count = ratetbl->rate[i].count_cts;
 672                         else
 673                                 rates[i].count = ratetbl->rate[i].count;
 674                 } else {
 675                         rates[i].idx = -1;
 676                         rates[i].count = 0;
 677                 }
 678
 679                 if (rates[i].idx < 0 || !rates[i].count)
 680                         break;
 681         }
 682 }
 683
 684 static bool rate_control_cap_mask(struct ieee80211_sub_if_data *sdata,
 685                                   struct ieee80211_supported_band *sband,
 686                                   struct ieee80211_sta *sta, u32 *mask,
 687                                   u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN],
 688                                   u16 vht_mask[NL80211_VHT_NSS_MAX])
 689 {
 690         u32 i, flags;
 691
 692         *mask = sdata->rc_rateidx_mask[sband->band];
 693         flags = ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
 694         for (i = 0; i < sband->n_bitrates; i++) {
 695                 if ((flags & sband->bitrates[i].flags) != flags)
 696                         *mask &= ~BIT(i);
 697         }
 698
 699         if (*mask == (1 << sband->n_bitrates) - 1 &&
 700             !sdata->rc_has_mcs_mask[sband->band] &&
 701             !sdata->rc_has_vht_mcs_mask[sband->band])
 702                 return false;
 703
 704         if (sdata->rc_has_mcs_mask[sband->band])
 705                 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[sband->band],
 706                        IEEE80211_HT_MCS_MASK_LEN);
 707         else
 708                 memset(mcs_mask, 0xff, IEEE80211_HT_MCS_MASK_LEN);
 709
 710         if (sdata->rc_has_vht_mcs_mask[sband->band])
 711                 memcpy(vht_mask, sdata->rc_rateidx_vht_mcs_mask[sband->band],
 712                        sizeof(u16) * NL80211_VHT_NSS_MAX);
 713         else
 714                 memset(vht_mask, 0xff, sizeof(u16) * NL80211_VHT_NSS_MAX);
 715
 716         if (sta) {
 717                 __le16 sta_vht_cap;
 718                 u16 sta_vht_mask[NL80211_VHT_NSS_MAX];
 719
 720                 /* Filter out rates that the STA does not support */
 721                 *mask &= sta->supp_rates[sband->band];
 722                 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++)
 723                         mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
 724
 725                 sta_vht_cap = sta->vht_cap.vht_mcs.rx_mcs_map;
 726                 ieee80211_get_vht_mask_from_cap(sta_vht_cap, sta_vht_mask);
 727                 for (i = 0; i < NL80211_VHT_NSS_MAX; i++)
 728                         vht_mask[i] &= sta_vht_mask[i];
 729         }
 730
 731         return true;
 732 }
 733
 734 static void
 735 rate_control_apply_mask_ratetbl(struct sta_info *sta,
 736                                 struct ieee80211_supported_band *sband,
 737                                 struct ieee80211_sta_rates *rates)
 738 {
 739         int i;
 740         u32 mask;
 741         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 742         u16 vht_mask[NL80211_VHT_NSS_MAX];
 743         enum nl80211_chan_width chan_width;
 744
 745         if (!rate_control_cap_mask(sta->sdata, sband, &sta->sta, &mask,
 746                                    mcs_mask, vht_mask))
 747                 return;
 748
 749         chan_width = sta->sdata->vif.bss_conf.chandef.width;
 750         for (i = 0; i < IEEE80211_TX_RATE_TABLE_SIZE; i++) {
 751                 if (rates->rate[i].idx < 0)
 752                         break;
 753
 754                 rate_idx_match_mask(&rates->rate[i].idx, &rates->rate[i].flags,
 755                                     sband, chan_width, mask, mcs_mask,
 756                                     vht_mask);
 757         }
 758 }
 759
 760 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
 761                                     struct ieee80211_sta *sta,
 762                                     struct ieee80211_supported_band *sband,
 763                                     struct ieee80211_tx_rate *rates,
 764                                     int max_rates)
 765 {
 766         enum nl80211_chan_width chan_width;
 767         u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
 768         u32 mask;
 769         u16 rate_flags, vht_mask[NL80211_VHT_NSS_MAX];
 770         int i;
 771
 772         /*
 773          * Try to enforce the rateidx mask the user wanted. skip this if the
 774          * default mask (allow all rates) is used to save some processing for
 775          * the common case.
 776          */
 777         if (!rate_control_cap_mask(sdata, sband, sta, &mask, mcs_mask,
 778                                    vht_mask))
 779                 return;
 780
 781         /*
 782          * Make sure the rate index selected for each TX rate is
 783          * included in the configured mask and change the rate indexes
 784          * if needed.
 785          */
 786         chan_width = sdata->vif.bss_conf.chandef.width;
 787         for (i = 0; i < max_rates; i++) {
 788                 /* Skip invalid rates */
 789                 if (rates[i].idx < 0)
 790                         break;
 791
 792                 rate_flags = rates[i].flags;
 793                 rate_idx_match_mask(&rates[i].idx, &rate_flags, sband,
 794                                     chan_width, mask, mcs_mask, vht_mask);
 795                 rates[i].flags = rate_flags;
 796         }
 797 }
 798
 799 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
 800                             struct ieee80211_sta *sta,
 801                             struct sk_buff *skb,
 802                             struct ieee80211_tx_rate *dest,
 803                             int max_rates)
 804 {
 805         struct ieee80211_sub_if_data *sdata;
 806         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 807         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 808         struct ieee80211_supported_band *sband;
 809
 810         rate_control_fill_sta_table(sta, info, dest, max_rates);
 811
 812         if (!vif)
 813                 return;
 814
 815         sdata = vif_to_sdata(vif);
 816         sband = sdata->local->hw.wiphy->bands[info->band];
 817
 818         if (ieee80211_is_data(hdr->frame_control))
 819                 rate_control_apply_mask(sdata, sta, sband, dest, max_rates);
 820
 821         if (dest[0].idx < 0)
 822                 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
 823                                         sdata->rc_rateidx_mask[info->band]);
 824
 825         if (sta)
 826                 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
 827 }
 828 EXPORT_SYMBOL(ieee80211_get_tx_rates);
 829
 830 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 831                            struct sta_info *sta,
 832                            struct ieee80211_tx_rate_control *txrc)
 833 {
 834         struct rate_control_ref *ref = sdata->local->rate_ctrl;
 835         void *priv_sta = NULL;
 836         struct ieee80211_sta *ista = NULL;
 837         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 838         int i;
 839
 840         if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 841                 ista = &sta->sta;
 842                 priv_sta = sta->rate_ctrl_priv;
 843         }
 844
 845         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 846                 info->control.rates[i].idx = -1;
 847                 info->control.rates[i].flags = 0;
 848                 info->control.rates[i].count = 0;
 849         }
 850
 851         if (ieee80211_hw_check(&sdata->local->hw, HAS_RATE_CONTROL))
 852                 return;
 853
 854         if (ista) {
 855                 spin_lock_bh(&sta->rate_ctrl_lock);
 856                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
 857                 spin_unlock_bh(&sta->rate_ctrl_lock);
 858         } else {
 859                 ref->ops->get_rate(ref->priv, NULL, NULL, txrc);
 860         }
 861
 862         if (ieee80211_hw_check(&sdata->local->hw, SUPPORTS_RC_TABLE))
 863                 return;
 864
 865         ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
 866                                info->control.rates,
 867                                ARRAY_SIZE(info->control.rates));
 868 }
 869
 870 int rate_control_set_rates(struct ieee80211_hw *hw,
 871                            struct ieee80211_sta *pubsta,
 872                            struct ieee80211_sta_rates *rates)
 873 {
 874         struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
 875         struct ieee80211_sta_rates *old;
 876         struct ieee80211_supported_band *sband;
 877
 878         sband = hw->wiphy->bands[ieee80211_get_sdata_band(sta->sdata)];
 879         rate_control_apply_mask_ratetbl(sta, sband, rates);
 880         /*
 881          * mac80211 guarantees that this function will not be called
 882          * concurrently, so the following RCU access is safe, even without
 883          * extra locking. This can not be checked easily, so we just set
 884          * the condition to true.
 885          */
 886         old = rcu_dereference_protected(pubsta->rates, true);
 887         rcu_assign_pointer(pubsta->rates, rates);
 888         if (old)
 889                 kfree_rcu(old, rcu_head);
 890
 891         drv_sta_rate_tbl_update(hw_to_local(hw), sta->sdata, pubsta);
 892
 893         return 0;
 894 }
 895 EXPORT_SYMBOL(rate_control_set_rates);
 896
 897 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 898                                  const char *name)
 899 {
 900         struct rate_control_ref *ref;
 901
 902         ASSERT_RTNL();
 903
 904         if (local->open_count)
 905                 return -EBUSY;
 906
 907         if (ieee80211_hw_check(&local->hw, HAS_RATE_CONTROL)) {
 908                 if (WARN_ON(!local->ops->set_rts_threshold))
 909                         return -EINVAL;
 910                 return 0;
 911         }
 912
 913         ref = rate_control_alloc(name, local);
 914         if (!ref) {
 915                 wiphy_warn(local->hw.wiphy,
 916                            "Failed to select rate control algorithm\n");
 917                 return -ENOENT;
 918         }
 919
 920         WARN_ON(local->rate_ctrl);
 921         local->rate_ctrl = ref;
 922
 923         wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 924                     ref->ops->name);
 925
 926         return 0;
 927 }
 928
 929 void rate_control_deinitialize(struct ieee80211_local *local)
 930 {
 931         struct rate_control_ref *ref;
 932
 933         ref = local->rate_ctrl;
 934
 935         if (!ref)
 936                 return;
 937
 938         local->rate_ctrl = NULL;
 939         rate_control_free(ref);
 940 }
 941