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                 sta->antenna_sel_tx = sta->antenna_sel_tx == 1 ? 2 : 1;
 151                 sta->antenna_sel_rx = sta->antenna_sel_rx == 1 ? 2 : 1;
 152                 if (local->sta_antenna_sel == STA_ANTENNA_SEL_SW_CTRL_DEBUG) {
 153                         printk(KERN_DEBUG "%s: " MAC_FMT " TX antenna --> %d "
 154                                "RX antenna --> %d (@%lu)\n",
 155                                dev->name, MAC_ARG(hdr->addr1),
 156                                sta->antenna_sel_tx, sta->antenna_sel_rx, jiffies);
 157                 }
 158                 srctrl->tx_num_failures++;
 159                 sta->tx_retry_failed++;
 160                 sta->tx_num_consecutive_failures++;
 161                 sta->tx_num_mpdu_fail++;
 162         } else {
 163                 sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
 164                 sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
 165                 sta->last_ack_rssi[2] = status->ack_signal;
 166                 sta->tx_num_consecutive_failures = 0;
 167                 sta->tx_num_mpdu_ok++;
 168         }
 169         sta->tx_retry_count += status->retry_count;
 170         sta->tx_num_mpdu_fail += status->retry_count;
 171
 172         if (time_after(jiffies,
 173                        srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
 174                 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
 175                 u32 per_failed;
 176                 srctrl->last_rate_change = jiffies;
 177
 178                 per_failed = (100 * sta->tx_num_mpdu_fail) /
 179                         (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
 180                 /* TODO: calculate average per_failed to make adjusting
 181                  * parameters easier */
 182 #if 0
 183                 if (net_ratelimit()) {
 184                         printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
 185                                sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
 186                                per_failed);
 187                 }
 188 #endif
 189
 190                 if (per_failed > local->rate_ctrl_num_down) {
 191                         rate_control_rate_dec(local, sta);
 192                 } else if (per_failed < local->rate_ctrl_num_up) {
 193                         rate_control_rate_inc(local, sta);
 194                 }
 195                 srctrl->tx_avg_rate_sum += status->control.rate->rate;
 196                 srctrl->tx_avg_rate_num++;
 197                 srctrl->tx_num_failures = 0;
 198                 srctrl->tx_num_xmit = 0;
 199         } else if (sta->tx_num_consecutive_failures >=
 200                    RATE_CONTROL_EMERG_DEC) {
 201                 rate_control_rate_dec(local, sta);
 202         }
 203
 204         if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
 205                 srctrl->avg_rate_update = jiffies;
 206                 if (srctrl->tx_avg_rate_num > 0) {
 207 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 208                         printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
 209                                "%d (%d/%d)\n",
 210                                dev->name, MAC_ARG(sta->addr),
 211                                srctrl->tx_avg_rate_sum /
 212                                srctrl->tx_avg_rate_num,
 213                                srctrl->tx_avg_rate_sum,
 214                                srctrl->tx_avg_rate_num);
 215 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 216                         srctrl->tx_avg_rate_sum = 0;
 217                         srctrl->tx_avg_rate_num = 0;
 218                 }
 219         }
 220
 221         sta_info_put(sta);
 222 }
 223
 224
 225 static struct ieee80211_rate *
 226 rate_control_simple_get_rate(void *priv, struct net_device *dev,
 227                              struct sk_buff *skb,
 228                              struct rate_control_extra *extra)
 229 {
 230         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 231         struct ieee80211_sub_if_data *sdata;
 232         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 233         struct ieee80211_hw_mode *mode = extra->mode;
 234         struct sta_info *sta;
 235         int rateidx, nonerp_idx;
 236         u16 fc;
 237
 238         memset(extra, 0, sizeof(*extra));
 239
 240         fc = le16_to_cpu(hdr->frame_control);
 241         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 242             (hdr->addr1[0] & 0x01)) {
 243                 /* Send management frames and broadcast/multicast data using
 244                  * lowest rate. */
 245                 /* TODO: this could probably be improved.. */
 246                 return rate_control_lowest_rate(local, mode);
 247         }
 248
 249         sta = sta_info_get(local, hdr->addr1);
 250
 251         if (!sta)
 252                 return rate_control_lowest_rate(local, mode);
 253
 254         sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 255         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
 256                 sta->txrate = sdata->bss->force_unicast_rateidx;
 257
 258         rateidx = sta->txrate;
 259
 260         if (rateidx >= mode->num_rates)
 261                 rateidx = mode->num_rates - 1;
 262
 263         sta->last_txrate = rateidx;
 264         nonerp_idx = rateidx;
 265         while (nonerp_idx > 0 &&
 266                ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
 267                 !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
 268                 !(sta->supp_rates & BIT(nonerp_idx))))
 269                 nonerp_idx--;
 270         extra->nonerp = &mode->rates[nonerp_idx];
 271
 272         sta_info_put(sta);
 273
 274         return &mode->rates[rateidx];
 275 }
 276
 277
 278 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
 279                                           struct ieee80211_local *local,
 280                                           struct sta_info *sta)
 281 {
 282         struct ieee80211_hw_mode *mode;
 283         int i;
 284         sta->txrate = 0;
 285         mode = local->oper_hw_mode;
 286         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 287          * the lowest or the highest rate.. Could consider using RSSI from
 288          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 289          * after assoc.. */
 290         for (i = 0; i < mode->num_rates; i++) {
 291                 if ((sta->supp_rates & BIT(i)) &&
 292                     (mode->rates[i].flags & IEEE80211_RATE_SUPPORTED))
 293                         sta->txrate = i;
 294         }
 295 }
 296
 297
 298 static void * rate_control_simple_alloc(struct ieee80211_local *local)
 299 {
 300         struct global_rate_control *rctrl;
 301
 302         rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
 303
 304         return rctrl;
 305 }
 306
 307
 308 static void rate_control_simple_free(void *priv)
 309 {
 310         struct global_rate_control *rctrl = priv;
 311         kfree(rctrl);
 312 }
 313
 314
 315 static void rate_control_simple_clear(void *priv)
 316 {
 317 }
 318
 319
 320 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
 321 {
 322         struct sta_rate_control *rctrl;
 323
 324         rctrl = kzalloc(sizeof(*rctrl), gfp);
 325
 326         return rctrl;
 327 }
 328
 329
 330 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
 331 {
 332         struct sta_rate_control *rctrl = priv_sta;
 333         kfree(rctrl);
 334 }
 335
 336 #ifdef CONFIG_MAC80211_DEBUGFS
 337
 338 static int open_file_generic(struct inode *inode, struct file *file)
 339 {
 340         file->private_data = inode->i_private;
 341         return 0;
 342 }
 343
 344 static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
 345                                         char __user *userbuf,
 346                                         size_t count, loff_t *ppos)
 347 {
 348         struct sta_rate_control *srctrl = file->private_data;
 349         char buf[20];
 350
 351         sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
 352         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 353 }
 354
 355 static const struct file_operations sta_tx_avg_rate_sum_ops = {
 356         .read = sta_tx_avg_rate_sum_read,
 357         .open = open_file_generic,
 358 };
 359
 360 static ssize_t sta_tx_avg_rate_num_read(struct file *file,
 361                                         char __user *userbuf,
 362                                         size_t count, loff_t *ppos)
 363 {
 364         struct sta_rate_control *srctrl = file->private_data;
 365         char buf[20];
 366
 367         sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
 368         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 369 }
 370
 371 static const struct file_operations sta_tx_avg_rate_num_ops = {
 372         .read = sta_tx_avg_rate_num_read,
 373         .open = open_file_generic,
 374 };
 375
 376 static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
 377                                                 struct dentry *dir)
 378 {
 379         struct sta_rate_control *srctrl = priv_sta;
 380
 381         srctrl->tx_avg_rate_num_dentry =
 382                 debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
 383                                     dir, srctrl, &sta_tx_avg_rate_num_ops);
 384         srctrl->tx_avg_rate_sum_dentry =
 385                 debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
 386                                     dir, srctrl, &sta_tx_avg_rate_sum_ops);
 387 }
 388
 389 static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
 390 {
 391         struct sta_rate_control *srctrl = priv_sta;
 392
 393         debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
 394         debugfs_remove(srctrl->tx_avg_rate_num_dentry);
 395 }
 396 #endif
 397
 398 static struct rate_control_ops rate_control_simple = {
 399         .module = THIS_MODULE,
 400         .name = "simple",
 401         .tx_status = rate_control_simple_tx_status,
 402         .get_rate = rate_control_simple_get_rate,
 403         .rate_init = rate_control_simple_rate_init,
 404         .clear = rate_control_simple_clear,
 405         .alloc = rate_control_simple_alloc,
 406         .free = rate_control_simple_free,
 407         .alloc_sta = rate_control_simple_alloc_sta,
 408         .free_sta = rate_control_simple_free_sta,
 409 #ifdef CONFIG_MAC80211_DEBUGFS
 410         .add_sta_debugfs = rate_control_simple_add_sta_debugfs,
 411         .remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
 412 #endif
 413 };
 414
 415
 416 static int __init rate_control_simple_init(void)
 417 {
 418         return ieee80211_rate_control_register(&rate_control_simple);
 419 }
 420
 421
 422 static void __exit rate_control_simple_exit(void)
 423 {
 424         ieee80211_rate_control_unregister(&rate_control_simple);
 425 }
 426
 427
 428 module_init(rate_control_simple_init);
 429 module_exit(rate_control_simple_exit);
 430
 431 MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
 432 MODULE_LICENSE("GPL");