Loading...
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
19struct rate_control_alg {
20 struct list_head list;
21 const struct rate_control_ops *ops;
22};
23
24static LIST_HEAD(rate_ctrl_algs);
25static DEFINE_MUTEX(rate_ctrl_mutex);
26
27static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
28module_param(ieee80211_default_rc_algo, charp, 0644);
29MODULE_PARM_DESC(ieee80211_default_rc_algo,
30 "Default rate control algorithm for mac80211 to use");
31
32void 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
64void 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
91int 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}
120EXPORT_SYMBOL(ieee80211_rate_control_register);
121
122void 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}
136EXPORT_SYMBOL(ieee80211_rate_control_unregister);
137
138static const struct rate_control_ops *
139ieee80211_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. */
159static const struct rate_control_ops *
160ieee80211_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
185static 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
195static const struct file_operations rcname_ops = {
196 .read = rcname_read,
197 .open = simple_open,
198 .llseek = default_llseek,
199};
200#endif
201
202static 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
227free:
228 kfree(ref);
229 return NULL;
230}
231
232static 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
244static 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
258static 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
280static 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
321bool 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}
357EXPORT_SYMBOL(rate_control_send_low);
358
359static 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
383static 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
420static 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
458static 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
543static 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
646static 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
684static 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
734static void
735rate_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
760static 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
799void 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}
828EXPORT_SYMBOL(ieee80211_get_tx_rates);
829
830void 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
870int 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}
895EXPORT_SYMBOL(rate_control_set_rates);
896
897int 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
929void 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
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
20struct rate_control_alg {
21 struct list_head list;
22 const struct rate_control_ops *ops;
23};
24
25static LIST_HEAD(rate_ctrl_algs);
26static DEFINE_MUTEX(rate_ctrl_mutex);
27
28static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
29module_param(ieee80211_default_rc_algo, charp, 0644);
30MODULE_PARM_DESC(ieee80211_default_rc_algo,
31 "Default rate control algorithm for mac80211 to use");
32
33void 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
65void 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
87void 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
114int 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}
143EXPORT_SYMBOL(ieee80211_rate_control_register);
144
145void 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}
159EXPORT_SYMBOL(ieee80211_rate_control_unregister);
160
161static const struct rate_control_ops *
162ieee80211_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. */
182static const struct rate_control_ops *
183ieee80211_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
210static 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
220static const struct file_operations rcname_ops = {
221 .read = rcname_read,
222 .open = simple_open,
223 .llseek = default_llseek,
224};
225#endif
226
227static 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
251free:
252 kfree(ref);
253 return NULL;
254}
255
256static 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
269void 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
295static 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
309static 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
331static 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
372bool 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}
408EXPORT_SYMBOL(rate_control_send_low);
409
410static 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
434static 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
471static 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
509static 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
594static 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
697static 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
735static 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
785static void
786rate_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
811static 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
850void 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}
879EXPORT_SYMBOL(ieee80211_get_tx_rates);
880
881void 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
921int 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}
950EXPORT_SYMBOL(rate_control_set_rates);
951
952int 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
984void 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}