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f0706e82 JB |
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> | |
ff688089 | 12 | #include <linux/rtnetlink.h> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
2c8dccc7 | 14 | #include "rate.h" |
f0706e82 | 15 | #include "ieee80211_i.h" |
4b7679a5 | 16 | #include "debugfs.h" |
f0706e82 JB |
17 | |
18 | struct rate_control_alg { | |
19 | struct list_head list; | |
20 | struct rate_control_ops *ops; | |
21 | }; | |
22 | ||
23 | static LIST_HEAD(rate_ctrl_algs); | |
24 | static DEFINE_MUTEX(rate_ctrl_mutex); | |
25 | ||
c21b39ac SB |
26 | static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; |
27 | module_param(ieee80211_default_rc_algo, charp, 0644); | |
28 | MODULE_PARM_DESC(ieee80211_default_rc_algo, | |
29 | "Default rate control algorithm for mac80211 to use"); | |
30 | ||
f0706e82 JB |
31 | int ieee80211_rate_control_register(struct rate_control_ops *ops) |
32 | { | |
33 | struct rate_control_alg *alg; | |
34 | ||
ac71c691 JB |
35 | if (!ops->name) |
36 | return -EINVAL; | |
37 | ||
999acd9c JB |
38 | mutex_lock(&rate_ctrl_mutex); |
39 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
40 | if (!strcmp(alg->ops->name, ops->name)) { | |
41 | /* don't register an algorithm twice */ | |
42 | WARN_ON(1); | |
b808ab16 | 43 | mutex_unlock(&rate_ctrl_mutex); |
999acd9c JB |
44 | return -EALREADY; |
45 | } | |
46 | } | |
47 | ||
dd00cc48 | 48 | alg = kzalloc(sizeof(*alg), GFP_KERNEL); |
f0706e82 | 49 | if (alg == NULL) { |
999acd9c | 50 | mutex_unlock(&rate_ctrl_mutex); |
f0706e82 JB |
51 | return -ENOMEM; |
52 | } | |
f0706e82 JB |
53 | alg->ops = ops; |
54 | ||
f0706e82 JB |
55 | list_add_tail(&alg->list, &rate_ctrl_algs); |
56 | mutex_unlock(&rate_ctrl_mutex); | |
57 | ||
58 | return 0; | |
59 | } | |
60 | EXPORT_SYMBOL(ieee80211_rate_control_register); | |
61 | ||
62 | void ieee80211_rate_control_unregister(struct rate_control_ops *ops) | |
63 | { | |
64 | struct rate_control_alg *alg; | |
65 | ||
66 | mutex_lock(&rate_ctrl_mutex); | |
67 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
68 | if (alg->ops == ops) { | |
69 | list_del(&alg->list); | |
20880e89 | 70 | kfree(alg); |
f0706e82 JB |
71 | break; |
72 | } | |
73 | } | |
74 | mutex_unlock(&rate_ctrl_mutex); | |
f0706e82 JB |
75 | } |
76 | EXPORT_SYMBOL(ieee80211_rate_control_unregister); | |
77 | ||
78 | static struct rate_control_ops * | |
79 | ieee80211_try_rate_control_ops_get(const char *name) | |
80 | { | |
81 | struct rate_control_alg *alg; | |
82 | struct rate_control_ops *ops = NULL; | |
83 | ||
ac71c691 JB |
84 | if (!name) |
85 | return NULL; | |
86 | ||
f0706e82 JB |
87 | mutex_lock(&rate_ctrl_mutex); |
88 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
ac71c691 | 89 | if (!strcmp(alg->ops->name, name)) |
f0706e82 JB |
90 | if (try_module_get(alg->ops->module)) { |
91 | ops = alg->ops; | |
92 | break; | |
93 | } | |
94 | } | |
95 | mutex_unlock(&rate_ctrl_mutex); | |
96 | return ops; | |
97 | } | |
98 | ||
c21b39ac | 99 | /* Get the rate control algorithm. */ |
f0706e82 JB |
100 | static struct rate_control_ops * |
101 | ieee80211_rate_control_ops_get(const char *name) | |
102 | { | |
103 | struct rate_control_ops *ops; | |
c21b39ac | 104 | const char *alg_name; |
f0706e82 | 105 | |
d6d1b650 | 106 | kparam_block_sysfs_write(ieee80211_default_rc_algo); |
ac71c691 | 107 | if (!name) |
c21b39ac SB |
108 | alg_name = ieee80211_default_rc_algo; |
109 | else | |
110 | alg_name = name; | |
ac71c691 | 111 | |
c21b39ac | 112 | ops = ieee80211_try_rate_control_ops_get(alg_name); |
f0706e82 | 113 | if (!ops) { |
c21b39ac SB |
114 | request_module("rc80211_%s", alg_name); |
115 | ops = ieee80211_try_rate_control_ops_get(alg_name); | |
f0706e82 | 116 | } |
c21b39ac SB |
117 | if (!ops && name) |
118 | /* try default if specific alg requested but not found */ | |
119 | ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); | |
120 | ||
4b475898 JB |
121 | /* try built-in one if specific alg requested but not found */ |
122 | if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) | |
123 | ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); | |
d6d1b650 | 124 | kparam_unblock_sysfs_write(ieee80211_default_rc_algo); |
4b475898 | 125 | |
f0706e82 JB |
126 | return ops; |
127 | } | |
128 | ||
129 | static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) | |
130 | { | |
131 | module_put(ops->module); | |
132 | } | |
133 | ||
4b7679a5 JB |
134 | #ifdef CONFIG_MAC80211_DEBUGFS |
135 | static ssize_t rcname_read(struct file *file, char __user *userbuf, | |
136 | size_t count, loff_t *ppos) | |
137 | { | |
138 | struct rate_control_ref *ref = file->private_data; | |
139 | int len = strlen(ref->ops->name); | |
140 | ||
141 | return simple_read_from_buffer(userbuf, count, ppos, | |
142 | ref->ops->name, len); | |
143 | } | |
144 | ||
145 | static const struct file_operations rcname_ops = { | |
146 | .read = rcname_read, | |
147 | .open = mac80211_open_file_generic, | |
6038f373 | 148 | .llseek = default_llseek, |
4b7679a5 JB |
149 | }; |
150 | #endif | |
151 | ||
209c671d | 152 | static struct rate_control_ref *rate_control_alloc(const char *name, |
f0706e82 JB |
153 | struct ieee80211_local *local) |
154 | { | |
4b7679a5 | 155 | struct dentry *debugfsdir = NULL; |
f0706e82 JB |
156 | struct rate_control_ref *ref; |
157 | ||
158 | ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); | |
159 | if (!ref) | |
160 | goto fail_ref; | |
161 | kref_init(&ref->kref); | |
4b7679a5 | 162 | ref->local = local; |
f0706e82 JB |
163 | ref->ops = ieee80211_rate_control_ops_get(name); |
164 | if (!ref->ops) | |
165 | goto fail_ops; | |
4b7679a5 JB |
166 | |
167 | #ifdef CONFIG_MAC80211_DEBUGFS | |
168 | debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); | |
169 | local->debugfs.rcdir = debugfsdir; | |
7bcfaf2f | 170 | debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); |
4b7679a5 JB |
171 | #endif |
172 | ||
173 | ref->priv = ref->ops->alloc(&local->hw, debugfsdir); | |
f0706e82 JB |
174 | if (!ref->priv) |
175 | goto fail_priv; | |
176 | return ref; | |
177 | ||
178 | fail_priv: | |
179 | ieee80211_rate_control_ops_put(ref->ops); | |
180 | fail_ops: | |
181 | kfree(ref); | |
182 | fail_ref: | |
183 | return NULL; | |
184 | } | |
185 | ||
186 | static void rate_control_release(struct kref *kref) | |
187 | { | |
188 | struct rate_control_ref *ctrl_ref; | |
189 | ||
190 | ctrl_ref = container_of(kref, struct rate_control_ref, kref); | |
191 | ctrl_ref->ops->free(ctrl_ref->priv); | |
4b7679a5 JB |
192 | |
193 | #ifdef CONFIG_MAC80211_DEBUGFS | |
7bcfaf2f | 194 | debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); |
4b7679a5 JB |
195 | ctrl_ref->local->debugfs.rcdir = NULL; |
196 | #endif | |
197 | ||
f0706e82 JB |
198 | ieee80211_rate_control_ops_put(ctrl_ref->ops); |
199 | kfree(ctrl_ref); | |
200 | } | |
201 | ||
4c6d4f5c LR |
202 | static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc) |
203 | { | |
204 | struct sk_buff *skb = txrc->skb; | |
205 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
206 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
207 | __le16 fc; | |
208 | ||
209 | fc = hdr->frame_control; | |
210 | ||
a02cec21 | 211 | return (info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc); |
4c6d4f5c LR |
212 | } |
213 | ||
dd5b4cc7 | 214 | static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, |
8f0729b1 | 215 | struct ieee80211_supported_band *sband) |
e00cfce0 JM |
216 | { |
217 | u8 i; | |
218 | ||
219 | if (basic_rates == 0) | |
220 | return; /* assume basic rates unknown and accept rate */ | |
221 | if (*idx < 0) | |
222 | return; | |
223 | if (basic_rates & (1 << *idx)) | |
224 | return; /* selected rate is a basic rate */ | |
225 | ||
8f0729b1 | 226 | for (i = *idx + 1; i <= sband->n_bitrates; i++) { |
e00cfce0 JM |
227 | if (basic_rates & (1 << i)) { |
228 | *idx = i; | |
229 | return; | |
230 | } | |
231 | } | |
232 | ||
233 | /* could not find a basic rate; use original selection */ | |
234 | } | |
235 | ||
4c6d4f5c LR |
236 | bool rate_control_send_low(struct ieee80211_sta *sta, |
237 | void *priv_sta, | |
238 | struct ieee80211_tx_rate_control *txrc) | |
239 | { | |
240 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); | |
dd5b4cc7 FF |
241 | struct ieee80211_supported_band *sband = txrc->sband; |
242 | int mcast_rate; | |
4c6d4f5c LR |
243 | |
244 | if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) { | |
245 | info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta); | |
246 | info->control.rates[0].count = | |
247 | (info->flags & IEEE80211_TX_CTL_NO_ACK) ? | |
248 | 1 : txrc->hw->max_rate_tries; | |
dd5b4cc7 FF |
249 | if (!sta && txrc->bss) { |
250 | mcast_rate = txrc->bss_conf->mcast_rate[sband->band]; | |
251 | if (mcast_rate > 0) { | |
252 | info->control.rates[0].idx = mcast_rate - 1; | |
253 | return true; | |
254 | } | |
255 | ||
e00cfce0 JM |
256 | rc_send_low_broadcast(&info->control.rates[0].idx, |
257 | txrc->bss_conf->basic_rates, | |
dd5b4cc7 FF |
258 | sband); |
259 | } | |
4c6d4f5c LR |
260 | return true; |
261 | } | |
262 | return false; | |
263 | } | |
264 | EXPORT_SYMBOL(rate_control_send_low); | |
265 | ||
37eb0b16 JM |
266 | static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, |
267 | int n_bitrates, u32 mask) | |
268 | { | |
269 | int j; | |
270 | ||
271 | /* See whether the selected rate or anything below it is allowed. */ | |
272 | for (j = rate->idx; j >= 0; j--) { | |
273 | if (mask & (1 << j)) { | |
274 | /* Okay, found a suitable rate. Use it. */ | |
275 | rate->idx = j; | |
276 | return; | |
277 | } | |
278 | } | |
279 | ||
280 | /* Try to find a higher rate that would be allowed */ | |
281 | for (j = rate->idx + 1; j < n_bitrates; j++) { | |
282 | if (mask & (1 << j)) { | |
283 | /* Okay, found a suitable rate. Use it. */ | |
284 | rate->idx = j; | |
285 | return; | |
286 | } | |
287 | } | |
288 | ||
289 | /* | |
290 | * Uh.. No suitable rate exists. This should not really happen with | |
291 | * sane TX rate mask configurations. However, should someone manage to | |
292 | * configure supported rates and TX rate mask in incompatible way, | |
293 | * allow the frame to be transmitted with whatever the rate control | |
294 | * selected. | |
295 | */ | |
296 | } | |
297 | ||
4b7679a5 | 298 | void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, |
e6a9854b JB |
299 | struct sta_info *sta, |
300 | struct ieee80211_tx_rate_control *txrc) | |
1abbe498 | 301 | { |
4b7679a5 JB |
302 | struct rate_control_ref *ref = sdata->local->rate_ctrl; |
303 | void *priv_sta = NULL; | |
304 | struct ieee80211_sta *ista = NULL; | |
e6a9854b | 305 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
1abbe498 | 306 | int i; |
37eb0b16 | 307 | u32 mask; |
1abbe498 | 308 | |
4b7679a5 JB |
309 | if (sta) { |
310 | ista = &sta->sta; | |
311 | priv_sta = sta->rate_ctrl_priv; | |
312 | } | |
313 | ||
e6a9854b JB |
314 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
315 | info->control.rates[i].idx = -1; | |
316 | info->control.rates[i].flags = 0; | |
317 | info->control.rates[i].count = 1; | |
318 | } | |
319 | ||
5affcd6b JO |
320 | if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) |
321 | return; | |
322 | ||
37eb0b16 | 323 | ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); |
e6a9854b JB |
324 | |
325 | /* | |
37eb0b16 JM |
326 | * Try to enforce the rateidx mask the user wanted. skip this if the |
327 | * default mask (allow all rates) is used to save some processing for | |
328 | * the common case. | |
e6a9854b | 329 | */ |
37eb0b16 JM |
330 | mask = sdata->rc_rateidx_mask[info->band]; |
331 | if (mask != (1 << txrc->sband->n_bitrates) - 1) { | |
332 | if (sta) { | |
333 | /* Filter out rates that the STA does not support */ | |
334 | mask &= sta->sta.supp_rates[info->band]; | |
335 | } | |
336 | /* | |
337 | * Make sure the rate index selected for each TX rate is | |
338 | * included in the configured mask and change the rate indexes | |
339 | * if needed. | |
340 | */ | |
e6a9854b | 341 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
5f4e6b2d CL |
342 | /* Skip invalid rates */ |
343 | if (info->control.rates[i].idx < 0) | |
344 | break; | |
37eb0b16 | 345 | /* Rate masking supports only legacy rates for now */ |
e6a9854b JB |
346 | if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) |
347 | continue; | |
37eb0b16 JM |
348 | rate_idx_match_mask(&info->control.rates[i], |
349 | txrc->sband->n_bitrates, mask); | |
350 | } | |
1abbe498 | 351 | } |
e6a9854b JB |
352 | |
353 | BUG_ON(info->control.rates[0].idx < 0); | |
1abbe498 MN |
354 | } |
355 | ||
f0706e82 JB |
356 | struct rate_control_ref *rate_control_get(struct rate_control_ref *ref) |
357 | { | |
358 | kref_get(&ref->kref); | |
359 | return ref; | |
360 | } | |
361 | ||
362 | void rate_control_put(struct rate_control_ref *ref) | |
363 | { | |
364 | kref_put(&ref->kref, rate_control_release); | |
365 | } | |
ff688089 JB |
366 | |
367 | int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, | |
368 | const char *name) | |
369 | { | |
370 | struct rate_control_ref *ref, *old; | |
371 | ||
372 | ASSERT_RTNL(); | |
af65cd96 | 373 | |
3b8d81e0 | 374 | if (local->open_count) |
ff688089 JB |
375 | return -EBUSY; |
376 | ||
af65cd96 JB |
377 | if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { |
378 | if (WARN_ON(!local->ops->set_rts_threshold)) | |
379 | return -EINVAL; | |
380 | return 0; | |
381 | } | |
382 | ||
ff688089 JB |
383 | ref = rate_control_alloc(name, local); |
384 | if (!ref) { | |
0fb9a9ec JP |
385 | wiphy_warn(local->hw.wiphy, |
386 | "Failed to select rate control algorithm\n"); | |
ff688089 JB |
387 | return -ENOENT; |
388 | } | |
389 | ||
390 | old = local->rate_ctrl; | |
391 | local->rate_ctrl = ref; | |
392 | if (old) { | |
393 | rate_control_put(old); | |
394 | sta_info_flush(local, NULL); | |
395 | } | |
396 | ||
0fb9a9ec JP |
397 | wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n", |
398 | ref->ops->name); | |
ff688089 | 399 | |
ff688089 JB |
400 | return 0; |
401 | } | |
402 | ||
403 | void rate_control_deinitialize(struct ieee80211_local *local) | |
404 | { | |
405 | struct rate_control_ref *ref; | |
406 | ||
407 | ref = local->rate_ctrl; | |
af65cd96 JB |
408 | |
409 | if (!ref) | |
410 | return; | |
411 | ||
ff688089 JB |
412 | local->rate_ctrl = NULL; |
413 | rate_control_put(ref); | |
414 | } | |
c21b39ac | 415 |