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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
32int ieee80211_rate_control_register(const struct rate_control_ops *ops)
33{
34 struct rate_control_alg *alg;
35
36 if (!ops->name)
37 return -EINVAL;
38
39 mutex_lock(&rate_ctrl_mutex);
40 list_for_each_entry(alg, &rate_ctrl_algs, list) {
41 if (!strcmp(alg->ops->name, ops->name)) {
42
43 WARN_ON(1);
44 mutex_unlock(&rate_ctrl_mutex);
45 return -EALREADY;
46 }
47 }
48
49 alg = kzalloc(sizeof(*alg), GFP_KERNEL);
50 if (alg == NULL) {
51 mutex_unlock(&rate_ctrl_mutex);
52 return -ENOMEM;
53 }
54 alg->ops = ops;
55
56 list_add_tail(&alg->list, &rate_ctrl_algs);
57 mutex_unlock(&rate_ctrl_mutex);
58
59 return 0;
60}
61EXPORT_SYMBOL(ieee80211_rate_control_register);
62
63void ieee80211_rate_control_unregister(const struct rate_control_ops *ops)
64{
65 struct rate_control_alg *alg;
66
67 mutex_lock(&rate_ctrl_mutex);
68 list_for_each_entry(alg, &rate_ctrl_algs, list) {
69 if (alg->ops == ops) {
70 list_del(&alg->list);
71 kfree(alg);
72 break;
73 }
74 }
75 mutex_unlock(&rate_ctrl_mutex);
76}
77EXPORT_SYMBOL(ieee80211_rate_control_unregister);
78
79static const struct rate_control_ops *
80ieee80211_try_rate_control_ops_get(const char *name)
81{
82 struct rate_control_alg *alg;
83 const struct rate_control_ops *ops = NULL;
84
85 if (!name)
86 return NULL;
87
88 mutex_lock(&rate_ctrl_mutex);
89 list_for_each_entry(alg, &rate_ctrl_algs, list) {
90 if (!strcmp(alg->ops->name, name)) {
91 ops = alg->ops;
92 break;
93 }
94 }
95 mutex_unlock(&rate_ctrl_mutex);
96 return ops;
97}
98
99
100static const struct rate_control_ops *
101ieee80211_rate_control_ops_get(const char *name)
102{
103 const struct rate_control_ops *ops;
104 const char *alg_name;
105
106 kparam_block_sysfs_write(ieee80211_default_rc_algo);
107 if (!name)
108 alg_name = ieee80211_default_rc_algo;
109 else
110 alg_name = name;
111
112 ops = ieee80211_try_rate_control_ops_get(alg_name);
113 if (!ops && name)
114
115 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
116
117
118 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
119 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
120 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
121
122 return ops;
123}
124
125#ifdef CONFIG_MAC80211_DEBUGFS
126static ssize_t rcname_read(struct file *file, char __user *userbuf,
127 size_t count, loff_t *ppos)
128{
129 struct rate_control_ref *ref = file->private_data;
130 int len = strlen(ref->ops->name);
131
132 return simple_read_from_buffer(userbuf, count, ppos,
133 ref->ops->name, len);
134}
135
136static const struct file_operations rcname_ops = {
137 .read = rcname_read,
138 .open = simple_open,
139 .llseek = default_llseek,
140};
141#endif
142
143static struct rate_control_ref *rate_control_alloc(const char *name,
144 struct ieee80211_local *local)
145{
146 struct dentry *debugfsdir = NULL;
147 struct rate_control_ref *ref;
148
149 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
150 if (!ref)
151 return NULL;
152 ref->local = local;
153 ref->ops = ieee80211_rate_control_ops_get(name);
154 if (!ref->ops)
155 goto free;
156
157#ifdef CONFIG_MAC80211_DEBUGFS
158 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
159 local->debugfs.rcdir = debugfsdir;
160 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
161#endif
162
163 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
164 if (!ref->priv)
165 goto free;
166 return ref;
167
168free:
169 kfree(ref);
170 return NULL;
171}
172
173static void rate_control_free(struct rate_control_ref *ctrl_ref)
174{
175 ctrl_ref->ops->free(ctrl_ref->priv);
176
177#ifdef CONFIG_MAC80211_DEBUGFS
178 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
179 ctrl_ref->local->debugfs.rcdir = NULL;
180#endif
181
182 kfree(ctrl_ref);
183}
184
185static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
186{
187 struct sk_buff *skb = txrc->skb;
188 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
189 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
190 __le16 fc;
191
192 fc = hdr->frame_control;
193
194 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
195 IEEE80211_TX_CTL_USE_MINRATE)) ||
196 !ieee80211_is_data(fc);
197}
198
199static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
200 struct ieee80211_supported_band *sband)
201{
202 u8 i;
203
204 if (basic_rates == 0)
205 return;
206 if (*idx < 0)
207 return;
208 if (basic_rates & (1 << *idx))
209 return;
210
211 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
212 if (basic_rates & (1 << i)) {
213 *idx = i;
214 return;
215 }
216 }
217
218
219}
220
221static void __rate_control_send_low(struct ieee80211_hw *hw,
222 struct ieee80211_supported_band *sband,
223 struct ieee80211_sta *sta,
224 struct ieee80211_tx_info *info,
225 u32 rate_mask)
226{
227 int i;
228 u32 rate_flags =
229 ieee80211_chandef_rate_flags(&hw->conf.chandef);
230
231 if ((sband->band == IEEE80211_BAND_2GHZ) &&
232 (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
233 rate_flags |= IEEE80211_RATE_ERP_G;
234
235 info->control.rates[0].idx = 0;
236 for (i = 0; i < sband->n_bitrates; i++) {
237 if (!(rate_mask & BIT(i)))
238 continue;
239
240 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
241 continue;
242
243 if (!rate_supported(sta, sband->band, i))
244 continue;
245
246 info->control.rates[0].idx = i;
247 break;
248 }
249 WARN_ON_ONCE(i == sband->n_bitrates);
250
251 info->control.rates[0].count =
252 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
253 1 : hw->max_rate_tries;
254
255 info->control.skip_table = 1;
256}
257
258
259bool rate_control_send_low(struct ieee80211_sta *pubsta,
260 void *priv_sta,
261 struct ieee80211_tx_rate_control *txrc)
262{
263 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
264 struct ieee80211_supported_band *sband = txrc->sband;
265 struct sta_info *sta;
266 int mcast_rate;
267 bool use_basicrate = false;
268
269 if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
270 __rate_control_send_low(txrc->hw, sband, pubsta, info,
271 txrc->rate_idx_mask);
272
273 if (!pubsta && txrc->bss) {
274 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
275 if (mcast_rate > 0) {
276 info->control.rates[0].idx = mcast_rate - 1;
277 return true;
278 }
279 use_basicrate = true;
280 } else if (pubsta) {
281 sta = container_of(pubsta, struct sta_info, sta);
282 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
283 use_basicrate = true;
284 }
285
286 if (use_basicrate)
287 rc_send_low_basicrate(&info->control.rates[0].idx,
288 txrc->bss_conf->basic_rates,
289 sband);
290
291 return true;
292 }
293 return false;
294}
295EXPORT_SYMBOL(rate_control_send_low);
296
297static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
298 int n_bitrates, u32 mask)
299{
300 int j;
301
302
303 for (j = rate->idx; j >= 0; j--) {
304 if (mask & (1 << j)) {
305
306 rate->idx = j;
307 return true;
308 }
309 }
310
311
312 for (j = rate->idx + 1; j < n_bitrates; j++) {
313 if (mask & (1 << j)) {
314
315 rate->idx = j;
316 return true;
317 }
318 }
319 return false;
320}
321
322static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
323 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
324{
325 int i, j;
326 int ridx, rbit;
327
328 ridx = rate->idx / 8;
329 rbit = rate->idx % 8;
330
331
332 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
333 return false;
334
335
336 for (i = ridx; i >= 0; i--) {
337 for (j = rbit; j >= 0; j--)
338 if (mcs_mask[i] & BIT(j)) {
339 rate->idx = i * 8 + j;
340 return true;
341 }
342 rbit = 7;
343 }
344
345
346 ridx = (rate->idx + 1) / 8;
347 rbit = (rate->idx + 1) % 8;
348
349 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
350 for (j = rbit; j < 8; j++)
351 if (mcs_mask[i] & BIT(j)) {
352 rate->idx = i * 8 + j;
353 return true;
354 }
355 rbit = 0;
356 }
357 return false;
358}
359
360
361
362static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
363 struct ieee80211_supported_band *sband,
364 enum nl80211_chan_width chan_width,
365 u32 mask,
366 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
367{
368 struct ieee80211_tx_rate alt_rate;
369
370
371 if (rate->flags & IEEE80211_TX_RC_MCS) {
372 if (rate_idx_match_mcs_mask(rate, mcs_mask))
373 return;
374
375
376 alt_rate.idx = 0;
377
378 alt_rate.flags = rate->flags &
379 (IEEE80211_TX_RC_USE_RTS_CTS |
380 IEEE80211_TX_RC_USE_CTS_PROTECT |
381 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
382 alt_rate.count = rate->count;
383 if (rate_idx_match_legacy_mask(&alt_rate,
384 sband->n_bitrates, mask)) {
385 *rate = alt_rate;
386 return;
387 }
388 } else {
389
390 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
391 return;
392
393
394 switch (chan_width) {
395 case NL80211_CHAN_WIDTH_20_NOHT:
396 case NL80211_CHAN_WIDTH_5:
397 case NL80211_CHAN_WIDTH_10:
398 return;
399 default:
400 break;
401 }
402
403 alt_rate.idx = 0;
404
405 alt_rate.flags = rate->flags &
406 (IEEE80211_TX_RC_USE_RTS_CTS |
407 IEEE80211_TX_RC_USE_CTS_PROTECT |
408 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
409 alt_rate.count = rate->count;
410
411 alt_rate.flags |= IEEE80211_TX_RC_MCS;
412
413 if (chan_width == NL80211_CHAN_WIDTH_40)
414 alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
415
416 if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
417 *rate = alt_rate;
418 return;
419 }
420 }
421
422
423
424
425
426
427
428
429}
430
431static void rate_fixup_ratelist(struct ieee80211_vif *vif,
432 struct ieee80211_supported_band *sband,
433 struct ieee80211_tx_info *info,
434 struct ieee80211_tx_rate *rates,
435 int max_rates)
436{
437 struct ieee80211_rate *rate;
438 bool inval = false;
439 int i;
440
441
442
443
444
445
446
447
448
449 if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) {
450 u32 basic_rates = vif->bss_conf.basic_rates;
451 s8 baserate = basic_rates ? ffs(basic_rates) - 1 : 0;
452
453 rate = &sband->bitrates[rates[0].idx];
454
455 for (i = 0; i < sband->n_bitrates; i++) {
456
457 if (!(basic_rates & BIT(i)))
458 continue;
459
460 if (sband->bitrates[i].bitrate > rate->bitrate)
461 continue;
462
463 if (sband->bitrates[baserate].bitrate <
464 sband->bitrates[i].bitrate)
465 baserate = i;
466 }
467
468 info->control.rts_cts_rate_idx = baserate;
469 }
470
471 for (i = 0; i < max_rates; i++) {
472
473
474
475
476
477 if (inval) {
478 rates[i].idx = -1;
479 continue;
480 }
481 if (rates[i].idx < 0) {
482 inval = true;
483 continue;
484 }
485
486
487
488
489
490 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
491 WARN_ON(rates[i].idx > 76);
492
493 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
494 info->control.use_cts_prot)
495 rates[i].flags |=
496 IEEE80211_TX_RC_USE_CTS_PROTECT;
497 continue;
498 }
499
500 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
501 WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
502 continue;
503 }
504
505
506 if (info->control.use_rts) {
507 rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
508 info->control.use_cts_prot = false;
509 }
510
511
512 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
513 rates[i].idx = -1;
514 continue;
515 }
516
517 rate = &sband->bitrates[rates[i].idx];
518
519
520 if (info->control.short_preamble &&
521 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
522 rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
523
524
525 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
526 info->control.use_cts_prot &&
527 rate->flags & IEEE80211_RATE_ERP_G)
528 rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
529 }
530}
531
532
533static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
534 struct ieee80211_tx_info *info,
535 struct ieee80211_tx_rate *rates,
536 int max_rates)
537{
538 struct ieee80211_sta_rates *ratetbl = NULL;
539 int i;
540
541 if (sta && !info->control.skip_table)
542 ratetbl = rcu_dereference(sta->rates);
543
544
545 max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
546 for (i = 0; i < max_rates; i++) {
547 if (i < ARRAY_SIZE(info->control.rates) &&
548 info->control.rates[i].idx >= 0 &&
549 info->control.rates[i].count) {
550 if (rates != info->control.rates)
551 rates[i] = info->control.rates[i];
552 } else if (ratetbl) {
553 rates[i].idx = ratetbl->rate[i].idx;
554 rates[i].flags = ratetbl->rate[i].flags;
555 if (info->control.use_rts)
556 rates[i].count = ratetbl->rate[i].count_rts;
557 else if (info->control.use_cts_prot)
558 rates[i].count = ratetbl->rate[i].count_cts;
559 else
560 rates[i].count = ratetbl->rate[i].count;
561 } else {
562 rates[i].idx = -1;
563 rates[i].count = 0;
564 }
565
566 if (rates[i].idx < 0 || !rates[i].count)
567 break;
568 }
569}
570
571static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
572 struct ieee80211_sta *sta,
573 struct ieee80211_supported_band *sband,
574 struct ieee80211_tx_info *info,
575 struct ieee80211_tx_rate *rates,
576 int max_rates)
577{
578 enum nl80211_chan_width chan_width;
579 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
580 bool has_mcs_mask;
581 u32 mask;
582 u32 rate_flags;
583 int i;
584
585
586
587
588
589
590 mask = sdata->rc_rateidx_mask[info->band];
591 has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
592 rate_flags =
593 ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
594 for (i = 0; i < sband->n_bitrates; i++)
595 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
596 mask &= ~BIT(i);
597
598 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
599 return;
600
601 if (has_mcs_mask)
602 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
603 sizeof(mcs_mask));
604 else
605 memset(mcs_mask, 0xff, sizeof(mcs_mask));
606
607 if (sta) {
608
609 mask &= sta->supp_rates[info->band];
610 for (i = 0; i < sizeof(mcs_mask); i++)
611 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
612 }
613
614
615
616
617
618
619 chan_width = sdata->vif.bss_conf.chandef.width;
620 for (i = 0; i < max_rates; i++) {
621
622 if (rates[i].idx < 0)
623 break;
624
625 rate_idx_match_mask(&rates[i], sband, chan_width, mask,
626 mcs_mask);
627 }
628}
629
630void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
631 struct ieee80211_sta *sta,
632 struct sk_buff *skb,
633 struct ieee80211_tx_rate *dest,
634 int max_rates)
635{
636 struct ieee80211_sub_if_data *sdata;
637 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
638 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
639 struct ieee80211_supported_band *sband;
640
641 rate_control_fill_sta_table(sta, info, dest, max_rates);
642
643 if (!vif)
644 return;
645
646 sdata = vif_to_sdata(vif);
647 sband = sdata->local->hw.wiphy->bands[info->band];
648
649 if (ieee80211_is_data(hdr->frame_control))
650 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
651
652 if (dest[0].idx < 0)
653 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
654 sdata->rc_rateidx_mask[info->band]);
655
656 if (sta)
657 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
658}
659EXPORT_SYMBOL(ieee80211_get_tx_rates);
660
661void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
662 struct sta_info *sta,
663 struct ieee80211_tx_rate_control *txrc)
664{
665 struct rate_control_ref *ref = sdata->local->rate_ctrl;
666 void *priv_sta = NULL;
667 struct ieee80211_sta *ista = NULL;
668 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
669 int i;
670
671 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
672 ista = &sta->sta;
673 priv_sta = sta->rate_ctrl_priv;
674 }
675
676 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
677 info->control.rates[i].idx = -1;
678 info->control.rates[i].flags = 0;
679 info->control.rates[i].count = 0;
680 }
681
682 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
683 return;
684
685 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
686
687 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
688 return;
689
690 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
691 info->control.rates,
692 ARRAY_SIZE(info->control.rates));
693}
694
695int rate_control_set_rates(struct ieee80211_hw *hw,
696 struct ieee80211_sta *pubsta,
697 struct ieee80211_sta_rates *rates)
698{
699 struct ieee80211_sta_rates *old;
700
701
702
703
704
705
706
707 old = rcu_dereference_protected(pubsta->rates, true);
708 rcu_assign_pointer(pubsta->rates, rates);
709 if (old)
710 kfree_rcu(old, rcu_head);
711
712 return 0;
713}
714EXPORT_SYMBOL(rate_control_set_rates);
715
716int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
717 const char *name)
718{
719 struct rate_control_ref *ref;
720
721 ASSERT_RTNL();
722
723 if (local->open_count)
724 return -EBUSY;
725
726 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
727 if (WARN_ON(!local->ops->set_rts_threshold))
728 return -EINVAL;
729 return 0;
730 }
731
732 ref = rate_control_alloc(name, local);
733 if (!ref) {
734 wiphy_warn(local->hw.wiphy,
735 "Failed to select rate control algorithm\n");
736 return -ENOENT;
737 }
738
739 WARN_ON(local->rate_ctrl);
740 local->rate_ctrl = ref;
741
742 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
743 ref->ops->name);
744
745 return 0;
746}
747
748void rate_control_deinitialize(struct ieee80211_local *local)
749{
750 struct rate_control_ref *ref;
751
752 ref = local->rate_ctrl;
753
754 if (!ref)
755 return;
756
757 local->rate_ctrl = NULL;
758 rate_control_free(ref);
759}
760
761