rc80211_simple.c
/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/compiler.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "debugfs.h"
/* This is a minimal implementation of TX rate controlling that can be used
* as the default when no improved mechanisms are available. */
#define RATE_CONTROL_EMERG_DEC 2
#define RATE_CONTROL_INTERVAL (HZ / 20)
#define RATE_CONTROL_MIN_TX 10
static void rate_control_rate_inc(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hw_mode *mode;
int i = sta->txrate;
int maxrate;
sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
/* forced unicast rate - do not change STA rate */
return;
}
mode = local->oper_hw_mode;
maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
if (i > mode->num_rates)
i = mode->num_rates - 2;
while (i + 1 < mode->num_rates) {
i++;
if (sta->supp_rates & BIT(i) &&
mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
(maxrate < 0 || i <= maxrate)) {
sta->txrate = i;
break;
}
}
}
static void rate_control_rate_dec(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hw_mode *mode;
int i = sta->txrate;
sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
/* forced unicast rate - do not change STA rate */
return;
}
mode = local->oper_hw_mode;
if (i > mode->num_rates)
i = mode->num_rates;
while (i > 0) {
i--;
if (sta->supp_rates & BIT(i) &&
mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
sta->txrate = i;
break;
}
}
}
static struct ieee80211_rate *
rate_control_lowest_rate(struct ieee80211_local *local,
struct ieee80211_hw_mode *mode)
{
int i;
for (i = 0; i < mode->num_rates; i++) {
struct ieee80211_rate *rate = &mode->rates[i];
if (rate->flags & IEEE80211_RATE_SUPPORTED)
return rate;
}
printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
"found\n");
return &mode->rates[0];
}
struct global_rate_control {
int dummy;
};
struct sta_rate_control {
unsigned long last_rate_change;
u32 tx_num_failures;
u32 tx_num_xmit;
unsigned long avg_rate_update;
u32 tx_avg_rate_sum;
u32 tx_avg_rate_num;
#ifdef CONFIG_MAC80211_DEBUGFS
struct dentry *tx_avg_rate_sum_dentry;
struct dentry *tx_avg_rate_num_dentry;
#endif
};
static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct ieee80211_tx_status *status)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct sta_info *sta;
struct sta_rate_control *srctrl;
sta = sta_info_get(local, hdr->addr1);
if (!sta)
return;
srctrl = sta->rate_ctrl_priv;
srctrl->tx_num_xmit++;
if (status->excessive_retries) {
srctrl->tx_num_failures++;
sta->tx_retry_failed++;
sta->tx_num_consecutive_failures++;
sta->tx_num_mpdu_fail++;
} else {
sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
sta->last_ack_rssi[2] = status->ack_signal;
sta->tx_num_consecutive_failures = 0;
sta->tx_num_mpdu_ok++;
}
sta->tx_retry_count += status->retry_count;
sta->tx_num_mpdu_fail += status->retry_count;
if (time_after(jiffies,
srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
u32 per_failed;
srctrl->last_rate_change = jiffies;
per_failed = (100 * sta->tx_num_mpdu_fail) /
(sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
/* TODO: calculate average per_failed to make adjusting
* parameters easier */
#if 0
if (net_ratelimit()) {
printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
per_failed);
}
#endif
/*
* XXX: Make these configurable once we have an
* interface to the rate control algorithms
*/
if (per_failed > RATE_CONTROL_NUM_DOWN) {
rate_control_rate_dec(local, sta);
} else if (per_failed < RATE_CONTROL_NUM_UP) {
rate_control_rate_inc(local, sta);
}
srctrl->tx_avg_rate_sum += status->control.rate->rate;
srctrl->tx_avg_rate_num++;
srctrl->tx_num_failures = 0;
srctrl->tx_num_xmit = 0;
} else if (sta->tx_num_consecutive_failures >=
RATE_CONTROL_EMERG_DEC) {
rate_control_rate_dec(local, sta);
}
if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
srctrl->avg_rate_update = jiffies;
if (srctrl->tx_avg_rate_num > 0) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
DECLARE_MAC_BUF(mac);
printk(KERN_DEBUG "%s: STA %s Average rate: "
"%d (%d/%d)\n",
dev->name, print_mac(mac, sta->addr),
srctrl->tx_avg_rate_sum /
srctrl->tx_avg_rate_num,
srctrl->tx_avg_rate_sum,
srctrl->tx_avg_rate_num);
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
srctrl->tx_avg_rate_sum = 0;
srctrl->tx_avg_rate_num = 0;
}
}
sta_info_put(sta);
}
static struct ieee80211_rate *
rate_control_simple_get_rate(void *priv, struct net_device *dev,
struct sk_buff *skb,
struct rate_control_extra *extra)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_sub_if_data *sdata;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_hw_mode *mode = extra->mode;
struct sta_info *sta;
int rateidx, nonerp_idx;
u16 fc;
memset(extra, 0, sizeof(*extra));
fc = le16_to_cpu(hdr->frame_control);
if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
(hdr->addr1[0] & 0x01)) {
/* Send management frames and broadcast/multicast data using
* lowest rate. */
/* TODO: this could probably be improved.. */
return rate_control_lowest_rate(local, mode);
}
sta = sta_info_get(local, hdr->addr1);
if (!sta)
return rate_control_lowest_rate(local, mode);
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
sta->txrate = sdata->bss->force_unicast_rateidx;
rateidx = sta->txrate;
if (rateidx >= mode->num_rates)
rateidx = mode->num_rates - 1;
sta->last_txrate = rateidx;
nonerp_idx = rateidx;
while (nonerp_idx > 0 &&
((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
!(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
!(sta->supp_rates & BIT(nonerp_idx))))
nonerp_idx--;
extra->nonerp = &mode->rates[nonerp_idx];
sta_info_put(sta);
return &mode->rates[rateidx];
}
static void rate_control_simple_rate_init(void *priv, void *priv_sta,
struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_hw_mode *mode;
int i;
sta->txrate = 0;
mode = local->oper_hw_mode;
/* TODO: This routine should consider using RSSI from previous packets
* as we need to have IEEE 802.1X auth succeed immediately after assoc..
* Until that method is implemented, we will use the lowest supported rate
* as a workaround, */
for (i = 0; i < mode->num_rates; i++) {
if ((sta->supp_rates & BIT(i)) &&
(mode->rates[i].flags & IEEE80211_RATE_SUPPORTED)) {
sta->txrate = i;
break;
}
}
}
static void * rate_control_simple_alloc(struct ieee80211_local *local)
{
struct global_rate_control *rctrl;
rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
return rctrl;
}
static void rate_control_simple_free(void *priv)
{
struct global_rate_control *rctrl = priv;
kfree(rctrl);
}
static void rate_control_simple_clear(void *priv)
{
}
static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
{
struct sta_rate_control *rctrl;
rctrl = kzalloc(sizeof(*rctrl), gfp);
return rctrl;
}
static void rate_control_simple_free_sta(void *priv, void *priv_sta)
{
struct sta_rate_control *rctrl = priv_sta;
kfree(rctrl);
}
#ifdef CONFIG_MAC80211_DEBUGFS
static int open_file_generic(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
char __user *userbuf,
size_t count, loff_t *ppos)
{
struct sta_rate_control *srctrl = file->private_data;
char buf[20];
sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
}
static const struct file_operations sta_tx_avg_rate_sum_ops = {
.read = sta_tx_avg_rate_sum_read,
.open = open_file_generic,
};
static ssize_t sta_tx_avg_rate_num_read(struct file *file,
char __user *userbuf,
size_t count, loff_t *ppos)
{
struct sta_rate_control *srctrl = file->private_data;
char buf[20];
sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
}
static const struct file_operations sta_tx_avg_rate_num_ops = {
.read = sta_tx_avg_rate_num_read,
.open = open_file_generic,
};
static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
struct dentry *dir)
{
struct sta_rate_control *srctrl = priv_sta;
srctrl->tx_avg_rate_num_dentry =
debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
dir, srctrl, &sta_tx_avg_rate_num_ops);
srctrl->tx_avg_rate_sum_dentry =
debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
dir, srctrl, &sta_tx_avg_rate_sum_ops);
}
static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
{
struct sta_rate_control *srctrl = priv_sta;
debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
debugfs_remove(srctrl->tx_avg_rate_num_dentry);
}
#endif
struct rate_control_ops mac80211_rcsimple = {
.name = "simple",
.tx_status = rate_control_simple_tx_status,
.get_rate = rate_control_simple_get_rate,
.rate_init = rate_control_simple_rate_init,
.clear = rate_control_simple_clear,
.alloc = rate_control_simple_alloc,
.free = rate_control_simple_free,
.alloc_sta = rate_control_simple_alloc_sta,
.free_sta = rate_control_simple_free_sta,
#ifdef CONFIG_MAC80211_DEBUGFS
.add_sta_debugfs = rate_control_simple_add_sta_debugfs,
.remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
#endif
};