fix up hostapd for mac80211
[openwrt/openwrt.git] / package / mac80211 / src / net / mac80211 / rc80211_simple.c
1 /*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/netdevice.h>
13 #include <linux/types.h>
14 #include <linux/slab.h>
15 #include <linux/skbuff.h>
16 #include <linux/compiler.h>
17
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "ieee80211_rate.h"
21 #include "debugfs.h"
22
23
24 /* This is a minimal implementation of TX rate controlling that can be used
25 * as the default when no improved mechanisms are available. */
26
27
28 #define RATE_CONTROL_EMERG_DEC 2
29 #define RATE_CONTROL_INTERVAL (HZ / 20)
30 #define RATE_CONTROL_MIN_TX 10
31
32 MODULE_ALIAS("rc80211_default");
33
34 static void rate_control_rate_inc(struct ieee80211_local *local,
35 struct sta_info *sta)
36 {
37 struct ieee80211_sub_if_data *sdata;
38 struct ieee80211_hw_mode *mode;
39 int i = sta->txrate;
40 int maxrate;
41
42 sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
43 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
44 /* forced unicast rate - do not change STA rate */
45 return;
46 }
47
48 mode = local->oper_hw_mode;
49 maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
50
51 if (i > mode->num_rates)
52 i = mode->num_rates - 2;
53
54 while (i + 1 < mode->num_rates) {
55 i++;
56 if (sta->supp_rates & BIT(i) &&
57 mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
58 (maxrate < 0 || i <= maxrate)) {
59 sta->txrate = i;
60 break;
61 }
62 }
63 }
64
65
66 static void rate_control_rate_dec(struct ieee80211_local *local,
67 struct sta_info *sta)
68 {
69 struct ieee80211_sub_if_data *sdata;
70 struct ieee80211_hw_mode *mode;
71 int i = sta->txrate;
72
73 sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
74 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
75 /* forced unicast rate - do not change STA rate */
76 return;
77 }
78
79 mode = local->oper_hw_mode;
80 if (i > mode->num_rates)
81 i = mode->num_rates;
82
83 while (i > 0) {
84 i--;
85 if (sta->supp_rates & BIT(i) &&
86 mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
87 sta->txrate = i;
88 break;
89 }
90 }
91 }
92
93
94 static struct ieee80211_rate *
95 rate_control_lowest_rate(struct ieee80211_local *local,
96 struct ieee80211_hw_mode *mode)
97 {
98 int i;
99
100 for (i = 0; i < mode->num_rates; i++) {
101 struct ieee80211_rate *rate = &mode->rates[i];
102
103 if (rate->flags & IEEE80211_RATE_SUPPORTED)
104 return rate;
105 }
106
107 printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
108 "found\n");
109 return &mode->rates[0];
110 }
111
112
113 struct global_rate_control {
114 int dummy;
115 };
116
117 struct sta_rate_control {
118 unsigned long last_rate_change;
119 u32 tx_num_failures;
120 u32 tx_num_xmit;
121
122 unsigned long avg_rate_update;
123 u32 tx_avg_rate_sum;
124 u32 tx_avg_rate_num;
125
126 #ifdef CONFIG_MAC80211_DEBUGFS
127 struct dentry *tx_avg_rate_sum_dentry;
128 struct dentry *tx_avg_rate_num_dentry;
129 #endif
130 };
131
132
133 static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
134 struct sk_buff *skb,
135 struct ieee80211_tx_status *status)
136 {
137 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
138 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
139 struct sta_info *sta;
140 struct sta_rate_control *srctrl;
141
142 sta = sta_info_get(local, hdr->addr1);
143
144 if (!sta)
145 return;
146
147 srctrl = sta->rate_ctrl_priv;
148 srctrl->tx_num_xmit++;
149 if (status->excessive_retries) {
150 srctrl->tx_num_failures++;
151 sta->tx_retry_failed++;
152 sta->tx_num_consecutive_failures++;
153 sta->tx_num_mpdu_fail++;
154 } else {
155 sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
156 sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
157 sta->last_ack_rssi[2] = status->ack_signal;
158 sta->tx_num_consecutive_failures = 0;
159 sta->tx_num_mpdu_ok++;
160 }
161 sta->tx_retry_count += status->retry_count;
162 sta->tx_num_mpdu_fail += status->retry_count;
163
164 if (time_after(jiffies,
165 srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
166 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
167 u32 per_failed;
168 srctrl->last_rate_change = jiffies;
169
170 per_failed = (100 * sta->tx_num_mpdu_fail) /
171 (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
172 /* TODO: calculate average per_failed to make adjusting
173 * parameters easier */
174 #if 0
175 if (net_ratelimit()) {
176 printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
177 sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
178 per_failed);
179 }
180 #endif
181
182 /*
183 * XXX: Make these configurable once we have an
184 * interface to the rate control algorithms
185 */
186 if (per_failed > RATE_CONTROL_NUM_DOWN) {
187 rate_control_rate_dec(local, sta);
188 } else if (per_failed < RATE_CONTROL_NUM_UP) {
189 rate_control_rate_inc(local, sta);
190 }
191 srctrl->tx_avg_rate_sum += status->control.rate->rate;
192 srctrl->tx_avg_rate_num++;
193 srctrl->tx_num_failures = 0;
194 srctrl->tx_num_xmit = 0;
195 } else if (sta->tx_num_consecutive_failures >=
196 RATE_CONTROL_EMERG_DEC) {
197 rate_control_rate_dec(local, sta);
198 }
199
200 if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
201 srctrl->avg_rate_update = jiffies;
202 if (srctrl->tx_avg_rate_num > 0) {
203 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
204 printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
205 "%d (%d/%d)\n",
206 dev->name, MAC_ARG(sta->addr),
207 srctrl->tx_avg_rate_sum /
208 srctrl->tx_avg_rate_num,
209 srctrl->tx_avg_rate_sum,
210 srctrl->tx_avg_rate_num);
211 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
212 srctrl->tx_avg_rate_sum = 0;
213 srctrl->tx_avg_rate_num = 0;
214 }
215 }
216
217 sta_info_put(sta);
218 }
219
220
221 static struct ieee80211_rate *
222 rate_control_simple_get_rate(void *priv, struct net_device *dev,
223 struct sk_buff *skb,
224 struct rate_control_extra *extra)
225 {
226 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
227 struct ieee80211_sub_if_data *sdata;
228 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
229 struct ieee80211_hw_mode *mode = extra->mode;
230 struct sta_info *sta;
231 int rateidx, nonerp_idx;
232 u16 fc;
233
234 memset(extra, 0, sizeof(*extra));
235
236 fc = le16_to_cpu(hdr->frame_control);
237 if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
238 (hdr->addr1[0] & 0x01)) {
239 /* Send management frames and broadcast/multicast data using
240 * lowest rate. */
241 /* TODO: this could probably be improved.. */
242 return rate_control_lowest_rate(local, mode);
243 }
244
245 sta = sta_info_get(local, hdr->addr1);
246
247 if (!sta)
248 return rate_control_lowest_rate(local, mode);
249
250 sdata = IEEE80211_DEV_TO_SUB_IF(dev);
251 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
252 sta->txrate = sdata->bss->force_unicast_rateidx;
253
254 rateidx = sta->txrate;
255
256 if (rateidx >= mode->num_rates)
257 rateidx = mode->num_rates - 1;
258
259 sta->last_txrate = rateidx;
260 nonerp_idx = rateidx;
261 while (nonerp_idx > 0 &&
262 ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
263 !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
264 !(sta->supp_rates & BIT(nonerp_idx))))
265 nonerp_idx--;
266 extra->nonerp = &mode->rates[nonerp_idx];
267
268 sta_info_put(sta);
269
270 return &mode->rates[rateidx];
271 }
272
273
274 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
275 struct ieee80211_local *local,
276 struct sta_info *sta)
277 {
278 struct ieee80211_hw_mode *mode;
279 int i;
280 sta->txrate = 0;
281 mode = local->oper_hw_mode;
282 /* TODO: This routine should consider using RSSI from previous packets
283 * as we need to have IEEE 802.1X auth succeed immediately after assoc..
284 * Until that method is implemented, we will use the lowest supported rate
285 * as a workaround, */
286 for (i = 0; i < mode->num_rates; i++) {
287 if ((sta->supp_rates & BIT(i)) &&
288 (mode->rates[i].flags & IEEE80211_RATE_SUPPORTED)) {
289 sta->txrate = i;
290 break;
291 }
292 }
293 }
294
295
296 static void * rate_control_simple_alloc(struct ieee80211_local *local)
297 {
298 struct global_rate_control *rctrl;
299
300 rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
301
302 return rctrl;
303 }
304
305
306 static void rate_control_simple_free(void *priv)
307 {
308 struct global_rate_control *rctrl = priv;
309 kfree(rctrl);
310 }
311
312
313 static void rate_control_simple_clear(void *priv)
314 {
315 }
316
317
318 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
319 {
320 struct sta_rate_control *rctrl;
321
322 rctrl = kzalloc(sizeof(*rctrl), gfp);
323
324 return rctrl;
325 }
326
327
328 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
329 {
330 struct sta_rate_control *rctrl = priv_sta;
331 kfree(rctrl);
332 }
333
334 #ifdef CONFIG_MAC80211_DEBUGFS
335
336 static int open_file_generic(struct inode *inode, struct file *file)
337 {
338 file->private_data = inode->i_private;
339 return 0;
340 }
341
342 static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
343 char __user *userbuf,
344 size_t count, loff_t *ppos)
345 {
346 struct sta_rate_control *srctrl = file->private_data;
347 char buf[20];
348
349 sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
350 return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
351 }
352
353 static const struct file_operations sta_tx_avg_rate_sum_ops = {
354 .read = sta_tx_avg_rate_sum_read,
355 .open = open_file_generic,
356 };
357
358 static ssize_t sta_tx_avg_rate_num_read(struct file *file,
359 char __user *userbuf,
360 size_t count, loff_t *ppos)
361 {
362 struct sta_rate_control *srctrl = file->private_data;
363 char buf[20];
364
365 sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
366 return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
367 }
368
369 static const struct file_operations sta_tx_avg_rate_num_ops = {
370 .read = sta_tx_avg_rate_num_read,
371 .open = open_file_generic,
372 };
373
374 static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
375 struct dentry *dir)
376 {
377 struct sta_rate_control *srctrl = priv_sta;
378
379 srctrl->tx_avg_rate_num_dentry =
380 debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
381 dir, srctrl, &sta_tx_avg_rate_num_ops);
382 srctrl->tx_avg_rate_sum_dentry =
383 debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
384 dir, srctrl, &sta_tx_avg_rate_sum_ops);
385 }
386
387 static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
388 {
389 struct sta_rate_control *srctrl = priv_sta;
390
391 debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
392 debugfs_remove(srctrl->tx_avg_rate_num_dentry);
393 }
394 #endif
395
396 static struct rate_control_ops rate_control_simple = {
397 .module = THIS_MODULE,
398 .name = "simple",
399 .tx_status = rate_control_simple_tx_status,
400 .get_rate = rate_control_simple_get_rate,
401 .rate_init = rate_control_simple_rate_init,
402 .clear = rate_control_simple_clear,
403 .alloc = rate_control_simple_alloc,
404 .free = rate_control_simple_free,
405 .alloc_sta = rate_control_simple_alloc_sta,
406 .free_sta = rate_control_simple_free_sta,
407 #ifdef CONFIG_MAC80211_DEBUGFS
408 .add_sta_debugfs = rate_control_simple_add_sta_debugfs,
409 .remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
410 #endif
411 };
412
413
414 static int __init rate_control_simple_init(void)
415 {
416 return ieee80211_rate_control_register(&rate_control_simple);
417 }
418
419
420 static void __exit rate_control_simple_exit(void)
421 {
422 ieee80211_rate_control_unregister(&rate_control_simple);
423 }
424
425
426 subsys_initcall(rate_control_simple_init);
427 module_exit(rate_control_simple_exit);
428
429 MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
430 MODULE_LICENSE("GPL");