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11#include <linux/kernel.h>
12#include <linux/rtnetlink.h>
13#include <linux/slab.h>
14#include <linux/module.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 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(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(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 struct rate_control_ops *
80ieee80211_try_rate_control_ops_get(const char *name)
81{
82 struct rate_control_alg *alg;
83 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 if (try_module_get(alg->ops->module)) {
92 ops = alg->ops;
93 break;
94 }
95 }
96 mutex_unlock(&rate_ctrl_mutex);
97 return ops;
98}
99
100
101static struct rate_control_ops *
102ieee80211_rate_control_ops_get(const char *name)
103{
104 struct rate_control_ops *ops;
105 const char *alg_name;
106
107 kparam_block_sysfs_write(ieee80211_default_rc_algo);
108 if (!name)
109 alg_name = ieee80211_default_rc_algo;
110 else
111 alg_name = name;
112
113 ops = ieee80211_try_rate_control_ops_get(alg_name);
114 if (!ops) {
115 request_module("rc80211_%s", alg_name);
116 ops = ieee80211_try_rate_control_ops_get(alg_name);
117 }
118 if (!ops && name)
119
120 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
121
122
123 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
124 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
125 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
126
127 return ops;
128}
129
130static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
131{
132 module_put(ops->module);
133}
134
135#ifdef CONFIG_MAC80211_DEBUGFS
136static ssize_t rcname_read(struct file *file, char __user *userbuf,
137 size_t count, loff_t *ppos)
138{
139 struct rate_control_ref *ref = file->private_data;
140 int len = strlen(ref->ops->name);
141
142 return simple_read_from_buffer(userbuf, count, ppos,
143 ref->ops->name, len);
144}
145
146static const struct file_operations rcname_ops = {
147 .read = rcname_read,
148 .open = simple_open,
149 .llseek = default_llseek,
150};
151#endif
152
153static struct rate_control_ref *rate_control_alloc(const char *name,
154 struct ieee80211_local *local)
155{
156 struct dentry *debugfsdir = NULL;
157 struct rate_control_ref *ref;
158
159 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
160 if (!ref)
161 goto fail_ref;
162 ref->local = local;
163 ref->ops = ieee80211_rate_control_ops_get(name);
164 if (!ref->ops)
165 goto fail_ops;
166
167#ifdef CONFIG_MAC80211_DEBUGFS
168 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
169 local->debugfs.rcdir = debugfsdir;
170 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
171#endif
172
173 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
174 if (!ref->priv)
175 goto fail_priv;
176 return ref;
177
178fail_priv:
179 ieee80211_rate_control_ops_put(ref->ops);
180fail_ops:
181 kfree(ref);
182fail_ref:
183 return NULL;
184}
185
186static void rate_control_free(struct rate_control_ref *ctrl_ref)
187{
188 ctrl_ref->ops->free(ctrl_ref->priv);
189
190#ifdef CONFIG_MAC80211_DEBUGFS
191 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
192 ctrl_ref->local->debugfs.rcdir = NULL;
193#endif
194
195 ieee80211_rate_control_ops_put(ctrl_ref->ops);
196 kfree(ctrl_ref);
197}
198
199static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
200{
201 struct sk_buff *skb = txrc->skb;
202 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
203 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
204 __le16 fc;
205
206 fc = hdr->frame_control;
207
208 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
209 IEEE80211_TX_CTL_USE_MINRATE)) ||
210 !ieee80211_is_data(fc);
211}
212
213static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
214 struct ieee80211_supported_band *sband)
215{
216 u8 i;
217
218 if (basic_rates == 0)
219 return;
220 if (*idx < 0)
221 return;
222 if (basic_rates & (1 << *idx))
223 return;
224
225 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
226 if (basic_rates & (1 << i)) {
227 *idx = i;
228 return;
229 }
230 }
231
232
233}
234
235static inline s8
236rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
237 struct ieee80211_sta *sta)
238{
239 int i;
240
241 for (i = 0; i < sband->n_bitrates; i++) {
242 struct ieee80211_rate *srate = &sband->bitrates[i];
243 if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
244 (srate->bitrate == 55) || (srate->bitrate == 110))
245 continue;
246
247 if (rate_supported(sta, sband->band, i))
248 return i;
249 }
250
251
252 return 0;
253}
254
255static void __rate_control_send_low(struct ieee80211_hw *hw,
256 struct ieee80211_supported_band *sband,
257 struct ieee80211_sta *sta,
258 struct ieee80211_tx_info *info)
259{
260 if ((sband->band != IEEE80211_BAND_2GHZ) ||
261 !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
262 info->control.rates[0].idx = rate_lowest_index(sband, sta);
263 else
264 info->control.rates[0].idx =
265 rate_lowest_non_cck_index(sband, sta);
266
267 info->control.rates[0].count =
268 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
269 1 : hw->max_rate_tries;
270
271 info->control.skip_table = 1;
272}
273
274
275bool rate_control_send_low(struct ieee80211_sta *sta,
276 void *priv_sta,
277 struct ieee80211_tx_rate_control *txrc)
278{
279 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
280 struct ieee80211_supported_band *sband = txrc->sband;
281 int mcast_rate;
282
283 if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
284 __rate_control_send_low(txrc->hw, sband, sta, info);
285
286 if (!sta && txrc->bss) {
287 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
288 if (mcast_rate > 0) {
289 info->control.rates[0].idx = mcast_rate - 1;
290 return true;
291 }
292
293 rc_send_low_broadcast(&info->control.rates[0].idx,
294 txrc->bss_conf->basic_rates,
295 sband);
296 }
297 return true;
298 }
299 return false;
300}
301EXPORT_SYMBOL(rate_control_send_low);
302
303static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
304 int n_bitrates, u32 mask)
305{
306 int j;
307
308
309 for (j = rate->idx; j >= 0; j--) {
310 if (mask & (1 << j)) {
311
312 rate->idx = j;
313 return true;
314 }
315 }
316
317
318 for (j = rate->idx + 1; j < n_bitrates; j++) {
319 if (mask & (1 << j)) {
320
321 rate->idx = j;
322 return true;
323 }
324 }
325 return false;
326}
327
328static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
329 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
330{
331 int i, j;
332 int ridx, rbit;
333
334 ridx = rate->idx / 8;
335 rbit = rate->idx % 8;
336
337
338 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
339 return false;
340
341
342 for (i = ridx; i >= 0; i--) {
343 for (j = rbit; j >= 0; j--)
344 if (mcs_mask[i] & BIT(j)) {
345 rate->idx = i * 8 + j;
346 return true;
347 }
348 rbit = 7;
349 }
350
351
352 ridx = (rate->idx + 1) / 8;
353 rbit = (rate->idx + 1) % 8;
354
355 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
356 for (j = rbit; j < 8; j++)
357 if (mcs_mask[i] & BIT(j)) {
358 rate->idx = i * 8 + j;
359 return true;
360 }
361 rbit = 0;
362 }
363 return false;
364}
365
366
367
368static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
369 struct ieee80211_supported_band *sband,
370 enum nl80211_chan_width chan_width,
371 u32 mask,
372 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
373{
374 struct ieee80211_tx_rate alt_rate;
375
376
377 if (rate->flags & IEEE80211_TX_RC_MCS) {
378 if (rate_idx_match_mcs_mask(rate, mcs_mask))
379 return;
380
381
382 alt_rate.idx = 0;
383
384 alt_rate.flags = rate->flags &
385 (IEEE80211_TX_RC_USE_RTS_CTS |
386 IEEE80211_TX_RC_USE_CTS_PROTECT |
387 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
388 alt_rate.count = rate->count;
389 if (rate_idx_match_legacy_mask(&alt_rate,
390 sband->n_bitrates, mask)) {
391 *rate = alt_rate;
392 return;
393 }
394 } else {
395
396 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
397 return;
398
399
400 if (chan_width == NL80211_CHAN_WIDTH_20_NOHT)
401 return;
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 int i;
583
584
585
586
587
588
589 mask = sdata->rc_rateidx_mask[info->band];
590 has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
591 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
592 return;
593
594 if (has_mcs_mask)
595 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
596 sizeof(mcs_mask));
597 else
598 memset(mcs_mask, 0xff, sizeof(mcs_mask));
599
600 if (sta) {
601
602 mask &= sta->supp_rates[info->band];
603 for (i = 0; i < sizeof(mcs_mask); i++)
604 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
605 }
606
607
608
609
610
611
612 chan_width = sdata->vif.bss_conf.chandef.width;
613 for (i = 0; i < max_rates; i++) {
614
615 if (rates[i].idx < 0)
616 break;
617
618 rate_idx_match_mask(&rates[i], sband, chan_width, mask,
619 mcs_mask);
620 }
621}
622
623void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
624 struct ieee80211_sta *sta,
625 struct sk_buff *skb,
626 struct ieee80211_tx_rate *dest,
627 int max_rates)
628{
629 struct ieee80211_sub_if_data *sdata;
630 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
631 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
632 struct ieee80211_supported_band *sband;
633
634 rate_control_fill_sta_table(sta, info, dest, max_rates);
635
636 if (!vif)
637 return;
638
639 sdata = vif_to_sdata(vif);
640 sband = sdata->local->hw.wiphy->bands[info->band];
641
642 if (ieee80211_is_data(hdr->frame_control))
643 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
644
645 if (dest[0].idx < 0)
646 __rate_control_send_low(&sdata->local->hw, sband, sta, info);
647
648 if (sta)
649 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
650}
651EXPORT_SYMBOL(ieee80211_get_tx_rates);
652
653void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
654 struct sta_info *sta,
655 struct ieee80211_tx_rate_control *txrc)
656{
657 struct rate_control_ref *ref = sdata->local->rate_ctrl;
658 void *priv_sta = NULL;
659 struct ieee80211_sta *ista = NULL;
660 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
661 int i;
662
663 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
664 ista = &sta->sta;
665 priv_sta = sta->rate_ctrl_priv;
666 }
667
668 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
669 info->control.rates[i].idx = -1;
670 info->control.rates[i].flags = 0;
671 info->control.rates[i].count = 0;
672 }
673
674 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
675 return;
676
677 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
678
679 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
680 return;
681
682 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
683 info->control.rates,
684 ARRAY_SIZE(info->control.rates));
685}
686
687int rate_control_set_rates(struct ieee80211_hw *hw,
688 struct ieee80211_sta *pubsta,
689 struct ieee80211_sta_rates *rates)
690{
691 struct ieee80211_sta_rates *old;
692
693
694
695
696
697
698
699 old = rcu_dereference_protected(pubsta->rates, true);
700 rcu_assign_pointer(pubsta->rates, rates);
701 if (old)
702 kfree_rcu(old, rcu_head);
703
704 return 0;
705}
706EXPORT_SYMBOL(rate_control_set_rates);
707
708int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
709 const char *name)
710{
711 struct rate_control_ref *ref;
712
713 ASSERT_RTNL();
714
715 if (local->open_count)
716 return -EBUSY;
717
718 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
719 if (WARN_ON(!local->ops->set_rts_threshold))
720 return -EINVAL;
721 return 0;
722 }
723
724 ref = rate_control_alloc(name, local);
725 if (!ref) {
726 wiphy_warn(local->hw.wiphy,
727 "Failed to select rate control algorithm\n");
728 return -ENOENT;
729 }
730
731 WARN_ON(local->rate_ctrl);
732 local->rate_ctrl = ref;
733
734 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
735 ref->ops->name);
736
737 return 0;
738}
739
740void rate_control_deinitialize(struct ieee80211_local *local)
741{
742 struct rate_control_ref *ref;
743
744 ref = local->rate_ctrl;
745
746 if (!ref)
747 return;
748
749 local->rate_ctrl = NULL;
750 rate_control_free(ref);
751}
752
753