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/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 #include <linux/module.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 #define RATE_CONTROL_NUM_DOWN 20
  28 #define RATE_CONTROL_NUM_UP   15
  29
  30 #define RATE_CONTROL_EMERG_DEC 2
  31 #define RATE_CONTROL_INTERVAL (HZ / 20)
  32 #define RATE_CONTROL_MIN_TX 10
  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_supported_band *sband;
  39         int i = sta->txrate_idx;
  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         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  49         maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
  50
  51         if (i > sband->n_bitrates)
  52                 i = sband->n_bitrates - 2;
  53
  54         while (i + 1 < sband->n_bitrates) {
  55                 i++;
  56                 if (rate_supported(sta, sband->band, i) &&
  57                     (maxrate < 0 || i <= maxrate)) {
  58                         sta->txrate_idx = i;
  59                         break;
  60                 }
  61         }
  62 }
  63
  64
  65 static void rate_control_rate_dec(struct ieee80211_local *local,
  66                                   struct sta_info *sta)
  67 {
  68         struct ieee80211_sub_if_data *sdata;
  69         struct ieee80211_supported_band *sband;
  70         int i = sta->txrate_idx;
  71
  72         sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
  73         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
  74                 /* forced unicast rate - do not change STA rate */
  75                 return;
  76         }
  77
  78         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
  79         if (i > sband->n_bitrates)
  80                 i = sband->n_bitrates;
  81
  82         while (i > 0) {
  83                 i--;
  84                 if (rate_supported(sta, sband->band, i)) {
  85                         sta->txrate_idx = i;
  86                         break;
  87                 }
  88         }
  89 }
  90
  91 struct global_rate_control {
  92         int dummy;
  93 };
  94
  95 struct sta_rate_control {
  96         unsigned long last_rate_change;
  97         u32 tx_num_failures;
  98         u32 tx_num_xmit;
  99
 100         unsigned long avg_rate_update;
 101         u32 tx_avg_rate_sum;
 102         u32 tx_avg_rate_num;
 103
 104 #ifdef CONFIG_MAC80211_DEBUGFS
 105         struct dentry *tx_avg_rate_sum_dentry;
 106         struct dentry *tx_avg_rate_num_dentry;
 107 #endif
 108 };
 109
 110
 111 static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
 112                                           struct sk_buff *skb,
 113                                           struct ieee80211_tx_status *status)
 114 {
 115         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 116         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 117         struct sta_info *sta;
 118         struct sta_rate_control *srctrl;
 119
 120         sta = sta_info_get(local, hdr->addr1);
 121
 122         if (!sta)
 123             return;
 124
 125         srctrl = sta->rate_ctrl_priv;
 126         srctrl->tx_num_xmit++;
 127         if (status->excessive_retries) {
 128                 srctrl->tx_num_failures++;
 129                 sta->tx_retry_failed++;
 130                 sta->tx_num_consecutive_failures++;
 131                 sta->tx_num_mpdu_fail++;
 132         } else {
 133                 sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
 134                 sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
 135                 sta->last_ack_rssi[2] = status->ack_signal;
 136                 sta->tx_num_consecutive_failures = 0;
 137                 sta->tx_num_mpdu_ok++;
 138         }
 139         sta->tx_retry_count += status->retry_count;
 140         sta->tx_num_mpdu_fail += status->retry_count;
 141
 142         if (time_after(jiffies,
 143                        srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
 144                 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
 145                 u32 per_failed;
 146                 srctrl->last_rate_change = jiffies;
 147
 148                 per_failed = (100 * sta->tx_num_mpdu_fail) /
 149                         (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
 150                 /* TODO: calculate average per_failed to make adjusting
 151                  * parameters easier */
 152 #if 0
 153                 if (net_ratelimit()) {
 154                         printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
 155                                sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
 156                                per_failed);
 157                 }
 158 #endif
 159
 160                 /*
 161                  * XXX: Make these configurable once we have an
 162                  * interface to the rate control algorithms
 163                  */
 164                 if (per_failed > RATE_CONTROL_NUM_DOWN) {
 165                         rate_control_rate_dec(local, sta);
 166                 } else if (per_failed < RATE_CONTROL_NUM_UP) {
 167                         rate_control_rate_inc(local, sta);
 168                 }
 169                 srctrl->tx_avg_rate_sum += status->control.tx_rate->bitrate;
 170                 srctrl->tx_avg_rate_num++;
 171                 srctrl->tx_num_failures = 0;
 172                 srctrl->tx_num_xmit = 0;
 173         } else if (sta->tx_num_consecutive_failures >=
 174                    RATE_CONTROL_EMERG_DEC) {
 175                 rate_control_rate_dec(local, sta);
 176         }
 177
 178         if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
 179                 srctrl->avg_rate_update = jiffies;
 180                 if (srctrl->tx_avg_rate_num > 0) {
 181 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 182                         DECLARE_MAC_BUF(mac);
 183                         printk(KERN_DEBUG "%s: STA %s Average rate: "
 184                                "%d (%d/%d)\n",
 185                                dev->name, print_mac(mac, sta->addr),
 186                                srctrl->tx_avg_rate_sum /
 187                                srctrl->tx_avg_rate_num,
 188                                srctrl->tx_avg_rate_sum,
 189                                srctrl->tx_avg_rate_num);
 190 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 191                         srctrl->tx_avg_rate_sum = 0;
 192                         srctrl->tx_avg_rate_num = 0;
 193                 }
 194         }
 195
 196         sta_info_put(sta);
 197 }
 198
 199
 200 static void
 201 rate_control_simple_get_rate(void *priv, struct net_device *dev,
 202                              struct ieee80211_supported_band *sband,
 203                              struct sk_buff *skb,
 204                              struct rate_selection *sel)
 205 {
 206         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 207         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 208         struct ieee80211_sub_if_data *sdata;
 209         struct sta_info *sta;
 210         int rateidx;
 211         u16 fc;
 212
 213         sta = sta_info_get(local, hdr->addr1);
 214
 215         /* Send management frames and broadcast/multicast data using lowest
 216          * rate. */
 217         fc = le16_to_cpu(hdr->frame_control);
 218         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 219             is_multicast_ether_addr(hdr->addr1) || !sta) {
 220                 sel->rate = rate_lowest(local, sband, sta);
 221                 if (sta)
 222                         sta_info_put(sta);
 223                 return;
 224         }
 225
 226         /* If a forced rate is in effect, select it. */
 227         sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 228         if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
 229                 sta->txrate_idx = sdata->bss->force_unicast_rateidx;
 230
 231         rateidx = sta->txrate_idx;
 232
 233         if (rateidx >= sband->n_bitrates)
 234                 rateidx = sband->n_bitrates - 1;
 235
 236         sta->last_txrate_idx = rateidx;
 237
 238         sta_info_put(sta);
 239
 240         sel->rate = &sband->bitrates[rateidx];
 241 }
 242
 243
 244 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
 245                                           struct ieee80211_local *local,
 246                                           struct sta_info *sta)
 247 {
 248         struct ieee80211_supported_band *sband;
 249
 250         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 251
 252         /* TODO: This routine should consider using RSSI from previous packets
 253          * as we need to have IEEE 802.1X auth succeed immediately after assoc..
 254          * Until that method is implemented, we will use the lowest supported rate
 255          * as a workaround, */
 256         sta->txrate_idx = rate_lowest_index(local, sband, sta);
 257 }
 258
 259
 260 static void * rate_control_simple_alloc(struct ieee80211_local *local)
 261 {
 262         struct global_rate_control *rctrl;
 263
 264         rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
 265
 266         return rctrl;
 267 }
 268
 269
 270 static void rate_control_simple_free(void *priv)
 271 {
 272         struct global_rate_control *rctrl = priv;
 273         kfree(rctrl);
 274 }
 275
 276
 277 static void rate_control_simple_clear(void *priv)
 278 {
 279 }
 280
 281
 282 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
 283 {
 284         struct sta_rate_control *rctrl;
 285
 286         rctrl = kzalloc(sizeof(*rctrl), gfp);
 287
 288         return rctrl;
 289 }
 290
 291
 292 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
 293 {
 294         struct sta_rate_control *rctrl = priv_sta;
 295         kfree(rctrl);
 296 }
 297
 298 #ifdef CONFIG_MAC80211_DEBUGFS
 299
 300 static int open_file_generic(struct inode *inode, struct file *file)
 301 {
 302         file->private_data = inode->i_private;
 303         return 0;
 304 }
 305
 306 static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
 307                                         char __user *userbuf,
 308                                         size_t count, loff_t *ppos)
 309 {
 310         struct sta_rate_control *srctrl = file->private_data;
 311         char buf[20];
 312
 313         sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
 314         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 315 }
 316
 317 static const struct file_operations sta_tx_avg_rate_sum_ops = {
 318         .read = sta_tx_avg_rate_sum_read,
 319         .open = open_file_generic,
 320 };
 321
 322 static ssize_t sta_tx_avg_rate_num_read(struct file *file,
 323                                         char __user *userbuf,
 324                                         size_t count, loff_t *ppos)
 325 {
 326         struct sta_rate_control *srctrl = file->private_data;
 327         char buf[20];
 328
 329         sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
 330         return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
 331 }
 332
 333 static const struct file_operations sta_tx_avg_rate_num_ops = {
 334         .read = sta_tx_avg_rate_num_read,
 335         .open = open_file_generic,
 336 };
 337
 338 static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
 339                                                 struct dentry *dir)
 340 {
 341         struct sta_rate_control *srctrl = priv_sta;
 342
 343         srctrl->tx_avg_rate_num_dentry =
 344                 debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
 345                                     dir, srctrl, &sta_tx_avg_rate_num_ops);
 346         srctrl->tx_avg_rate_sum_dentry =
 347                 debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
 348                                     dir, srctrl, &sta_tx_avg_rate_sum_ops);
 349 }
 350
 351 static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
 352 {
 353         struct sta_rate_control *srctrl = priv_sta;
 354
 355         debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
 356         debugfs_remove(srctrl->tx_avg_rate_num_dentry);
 357 }
 358 #endif
 359
 360 static struct rate_control_ops mac80211_rcsimple = {
 361         .name = "simple",
 362         .tx_status = rate_control_simple_tx_status,
 363         .get_rate = rate_control_simple_get_rate,
 364         .rate_init = rate_control_simple_rate_init,
 365         .clear = rate_control_simple_clear,
 366         .alloc = rate_control_simple_alloc,
 367         .free = rate_control_simple_free,
 368         .alloc_sta = rate_control_simple_alloc_sta,
 369         .free_sta = rate_control_simple_free_sta,
 370 #ifdef CONFIG_MAC80211_DEBUGFS
 371         .add_sta_debugfs = rate_control_simple_add_sta_debugfs,
 372         .remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
 373 #endif
 374 };
 375
 376 MODULE_LICENSE("GPL");
 377 MODULE_DESCRIPTION("Simple rate control algorithm");
 378
 379 int __init rc80211_simple_init(void)
 380 {
 381         return ieee80211_rate_control_register(&mac80211_rcsimple);
 382 }
 383
 384 void rc80211_simple_exit(void)
 385 {
 386         ieee80211_rate_control_unregister(&mac80211_rcsimple);
 387 }
 388
 389 #ifdef CONFIG_MAC80211_RC_SIMPLE_MODULE
 390 module_init(rc80211_simple_init);
 391 module_exit(rc80211_simple_exit);
 392 #endif