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/init.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/types.h>
  13 #include <linux/slab.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/compiler.h>
  16
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "ieee80211_rate.h"
  20 #include "debugfs.h"
  21
  22
  23 /* This is a minimal implementation of TX rate controlling that can be used
  24  * as the default when no improved mechanisms are available. */
  25
  26
  27 #define RATE_CONTROL_EMERG_DEC 2
  28 #define RATE_CONTROL_INTERVAL (HZ / 20)
  29 #define RATE_CONTROL_MIN_TX 10
  30
  31 static void rate_control_rate_inc(struct ieee80211_local *local,
  32                                   struct sta_info *sta)
  33 {
  34         struct ieee80211_sub_if_data *sdata;
  35         struct ieee80211_hw_mode *mode;
  36         int i = sta->txrate;
  37         int maxrate;
  38
  39         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
  40         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
  41                 /* forced unicast rate - do not change STA rate */
  42                 return;
  43         }
  44
  45         mode = local->oper_hw_mode;
  46         maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
  47
  48         if (i > mode->num_rates)
  49                 i = mode->num_rates - 2;
  50
  51         while (i + 1 < mode->num_rates) {
  52                 i++;
  53                 if (sta->supp_rates & BIT(i) &&
  54                     mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
  55                     (maxrate < 0 || i <= maxrate)) {
  56                         sta->txrate = i;
  57                         break;
  58                 }
  59         }
  60 }
  61
  62
  63 static void rate_control_rate_dec(struct ieee80211_local *local,
  64                                   struct sta_info *sta)
  65 {
  66         struct ieee80211_sub_if_data *sdata;
  67         struct ieee80211_hw_mode *mode;
  68         int i = sta->txrate;
  69
  70         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
  71         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
  72                 /* forced unicast rate - do not change STA rate */
  73                 return;
  74         }
  75
  76         mode = local->oper_hw_mode;
  77         if (i > mode->num_rates)
  78                 i = mode->num_rates;
  79
  80         while (i > 0) {
  81                 i--;
  82                 if (sta->supp_rates & BIT(i) &&
  83                     mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
  84                         sta->txrate = i;
  85                         break;
  86                 }
  87         }
  88 }
  89
  90
  91 static struct ieee80211_rate *
  92 rate_control_lowest_rate(struct ieee80211_local *local,
  93                          struct ieee80211_hw_mode *mode)
  94 {
  95         int i;
  96
  97         for (i = 0; i < mode->num_rates; i++) {
  98                 struct ieee80211_rate *rate = &mode->rates[i];
  99
 100                 if (rate->flags & IEEE80211_RATE_SUPPORTED)
 101                         return rate;
 102         }
 103
 104         printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
 105                "found\n");
 106         return &mode->rates[0];
 107 }
 108
 109
 110 struct global_rate_control {
 111         int dummy;
 112 };
 113
 114 struct sta_rate_control {
 115         unsigned long last_rate_change;
 116         u32 tx_num_failures;
 117         u32 tx_num_xmit;
 118
 119         unsigned long avg_rate_update;
 120         u32 tx_avg_rate_sum;
 121         u32 tx_avg_rate_num;
 122
 123 #ifdef CONFIG_MAC80211_DEBUGFS
 124         struct dentry *tx_avg_rate_sum_dentry;
 125         struct dentry *tx_avg_rate_num_dentry;
 126 #endif
 127 };
 128
 129
 130 static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
 131                                           struct sk_buff *skb,
 132                                           struct ieee80211_tx_status *status)
 133 {
 134         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 135         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 136         struct sta_info *sta;
 137         struct sta_rate_control *srctrl;
 138
 139         sta = sta_info_get(local, hdr->addr1);
 140
 141         if (!sta)
 142             return;
 143
 144         srctrl = sta->rate_ctrl_priv;
 145         srctrl->tx_num_xmit++;
 146         if (status->excessive_retries) {
 147                 srctrl->tx_num_failures++;
 148                 sta->tx_retry_failed++;
 149                 sta->tx_num_consecutive_failures++;
 150                 sta->tx_num_mpdu_fail++;
 151         } else {
 152                 sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
 153                 sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
 154                 sta->last_ack_rssi[2] = status->ack_signal;
 155                 sta->tx_num_consecutive_failures = 0;
 156                 sta->tx_num_mpdu_ok++;
 157         }
 158         sta->tx_retry_count += status->retry_count;
 159         sta->tx_num_mpdu_fail += status->retry_count;
 160
 161         if (time_after(jiffies,
 162                        srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
 163                 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
 164                 u32 per_failed;
 165                 srctrl->last_rate_change = jiffies;
 166
 167                 per_failed = (100 * sta->tx_num_mpdu_fail) /
 168                         (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
 169                 /* TODO: calculate average per_failed to make adjusting
 170                  * parameters easier */
 171 #if 0
 172                 if (net_ratelimit()) {
 173                         printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
 174                                sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
 175                                per_failed);
 176                 }
 177 #endif
 178
 179                 /*
 180                  * XXX: Make these configurable once we have an
 181                  * interface to the rate control algorithms
 182                  */
 183                 if (per_failed > RATE_CONTROL_NUM_DOWN) {
 184                         rate_control_rate_dec(local, sta);
 185                 } else if (per_failed < RATE_CONTROL_NUM_UP) {
 186                         rate_control_rate_inc(local, sta);
 187                 }
 188                 srctrl->tx_avg_rate_sum += status->control.rate->rate;
 189                 srctrl->tx_avg_rate_num++;
 190                 srctrl->tx_num_failures = 0;
 191                 srctrl->tx_num_xmit = 0;
 192         } else if (sta->tx_num_consecutive_failures >=
 193                    RATE_CONTROL_EMERG_DEC) {
 194                 rate_control_rate_dec(local, sta);
 195         }
 196
 197         if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
 198                 srctrl->avg_rate_update = jiffies;
 199                 if (srctrl->tx_avg_rate_num > 0) {
 200 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 201                         DECLARE_MAC_BUF(mac);
 202                         printk(KERN_DEBUG "%s: STA %s Average rate: "
 203                                "%d (%d/%d)\n",
 204                                dev->name, print_mac(mac, sta->addr),
 205                                srctrl->tx_avg_rate_sum /
 206                                srctrl->tx_avg_rate_num,
 207                                srctrl->tx_avg_rate_sum,
 208                                srctrl->tx_avg_rate_num);
 209 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 210                         srctrl->tx_avg_rate_sum = 0;
 211                         srctrl->tx_avg_rate_num = 0;
 212                 }
 213         }
 214
 215         sta_info_put(sta);
 216 }
 217
 218
 219 static struct ieee80211_rate *
 220 rate_control_simple_get_rate(void *priv, struct net_device *dev,
 221                              struct sk_buff *skb,
 222                              struct rate_control_extra *extra)
 223 {
 224         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 225         struct ieee80211_sub_if_data *sdata;
 226         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 227         struct ieee80211_hw_mode *mode = extra->mode;
 228         struct sta_info *sta;
 229         int rateidx, nonerp_idx;
 230         u16 fc;
 231
 232         memset(extra, 0, sizeof(*extra));
 233
 234         fc = le16_to_cpu(hdr->frame_control);
 235         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 236             (hdr->addr1[0] & 0x01)) {
 237                 /* Send management frames and broadcast/multicast data using
 238                  * lowest rate. */
 239                 /* TODO: this could probably be improved.. */
 240                 return rate_control_lowest_rate(local, mode);
 241         }
 242
 243         sta = sta_info_get(local, hdr->addr1);
 244
 245         if (!sta)
 246                 return rate_control_lowest_rate(local, mode);
 247
 248         sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 249         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
 250                 sta->txrate = sdata->bss->force_unicast_rateidx;
 251
 252         rateidx = sta->txrate;
 253
 254         if (rateidx >= mode->num_rates)
 255                 rateidx = mode->num_rates - 1;
 256
 257         sta->last_txrate = rateidx;
 258         nonerp_idx = rateidx;
 259         while (nonerp_idx > 0 &&
 260                ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
 261                 !(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
 262                 !(sta->supp_rates & BIT(nonerp_idx))))
 263                 nonerp_idx--;
 264         extra->nonerp = &mode->rates[nonerp_idx];
 265
 266         sta_info_put(sta);
 267
 268         return &mode->rates[rateidx];
 269 }
 270
 271
 272 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
 273                                           struct ieee80211_local *local,
 274                                           struct sta_info *sta)
 275 {
 276         struct ieee80211_hw_mode *mode;
 277         int i;
 278         sta->txrate = 0;
 279         mode = local->oper_hw_mode;
 280         /* TODO: This routine should consider using RSSI from previous packets
 281          * as we need to have IEEE 802.1X auth succeed immediately after assoc..
 282          * Until that method is implemented, we will use the lowest supported rate
 283          * as a workaround, */
 284         for (i = 0; i < mode->num_rates; i++) {
 285                 if ((sta->supp_rates & BIT(i)) &&
 286                     (mode->rates[i].flags & IEEE80211_RATE_SUPPORTED)) {
 287                         sta->txrate = i;
 288                         break;
 289                 }
 290         }
 291 }
 292
 293
 294 static void * rate_control_simple_alloc(struct ieee80211_local *local)
 295 {
 296         struct global_rate_control *rctrl;
 297
 298         rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
 299
 300         return rctrl;
 301 }
 302
 303
 304 static void rate_control_simple_free(void *priv)
 305 {
 306         struct global_rate_control *rctrl = priv;
 307         kfree(rctrl);
 308 }
 309
 310
 311 static void rate_control_simple_clear(void *priv)
 312 {
 313 }
 314
 315
 316 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
 317 {
 318         struct sta_rate_control *rctrl;
 319
 320         rctrl = kzalloc(sizeof(*rctrl), gfp);
 321
 322         return rctrl;
 323 }
 324
 325
 326 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
 327 {
 328         struct sta_rate_control *rctrl = priv_sta;
 329         kfree(rctrl);
 330 }
 331
 332 #ifdef CONFIG_MAC80211_DEBUGFS
 333
 334 static int open_file_generic(struct inode *inode, struct file *file)
 335 {
 336         file->private_data = inode->i_private;
 337         return 0;
 338 }
 339
 340 static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
 341                                         char __user *userbuf,
 342                                         size_t count, loff_t *ppos)
 343 {
 344         struct sta_rate_control *srctrl = file->private_data;
 345         char buf[20];
 346
 347         sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
 348         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 349 }
 350
 351 static const struct file_operations sta_tx_avg_rate_sum_ops = {
 352         .read = sta_tx_avg_rate_sum_read,
 353         .open = open_file_generic,
 354 };
 355
 356 static ssize_t sta_tx_avg_rate_num_read(struct file *file,
 357                                         char __user *userbuf,
 358                                         size_t count, loff_t *ppos)
 359 {
 360         struct sta_rate_control *srctrl = file->private_data;
 361         char buf[20];
 362
 363         sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
 364         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 365 }
 366
 367 static const struct file_operations sta_tx_avg_rate_num_ops = {
 368         .read = sta_tx_avg_rate_num_read,
 369         .open = open_file_generic,
 370 };
 371
 372 static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
 373                                                 struct dentry *dir)
 374 {
 375         struct sta_rate_control *srctrl = priv_sta;
 376
 377         srctrl->tx_avg_rate_num_dentry =
 378                 debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
 379                                     dir, srctrl, &sta_tx_avg_rate_num_ops);
 380         srctrl->tx_avg_rate_sum_dentry =
 381                 debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
 382                                     dir, srctrl, &sta_tx_avg_rate_sum_ops);
 383 }
 384
 385 static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
 386 {
 387         struct sta_rate_control *srctrl = priv_sta;
 388
 389         debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
 390         debugfs_remove(srctrl->tx_avg_rate_num_dentry);
 391 }
 392 #endif
 393
 394 struct rate_control_ops mac80211_rcsimple = {
 395         .name = "simple",
 396         .tx_status = rate_control_simple_tx_status,
 397         .get_rate = rate_control_simple_get_rate,
 398         .rate_init = rate_control_simple_rate_init,
 399         .clear = rate_control_simple_clear,
 400         .alloc = rate_control_simple_alloc,
 401         .free = rate_control_simple_free,
 402         .alloc_sta = rate_control_simple_alloc_sta,
 403         .free_sta = rate_control_simple_free_sta,
 404 #ifdef CONFIG_MAC80211_DEBUGFS
 405         .add_sta_debugfs = rate_control_simple_add_sta_debugfs,
 406         .remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
 407 #endif
 408 };