535 lines
13 KiB
C
535 lines
13 KiB
C
/*
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* Copyright 2002-2005, Instant802 Networks, Inc.
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* Copyright 2005-2006, Devicescape Software, Inc.
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* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/rtnetlink.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include "rate.h"
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#include "ieee80211_i.h"
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#include "debugfs.h"
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struct rate_control_alg {
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struct list_head list;
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struct rate_control_ops *ops;
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};
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static LIST_HEAD(rate_ctrl_algs);
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static DEFINE_MUTEX(rate_ctrl_mutex);
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static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
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module_param(ieee80211_default_rc_algo, charp, 0644);
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MODULE_PARM_DESC(ieee80211_default_rc_algo,
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"Default rate control algorithm for mac80211 to use");
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int ieee80211_rate_control_register(struct rate_control_ops *ops)
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{
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struct rate_control_alg *alg;
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if (!ops->name)
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return -EINVAL;
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mutex_lock(&rate_ctrl_mutex);
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list_for_each_entry(alg, &rate_ctrl_algs, list) {
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if (!strcmp(alg->ops->name, ops->name)) {
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/* don't register an algorithm twice */
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WARN_ON(1);
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mutex_unlock(&rate_ctrl_mutex);
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return -EALREADY;
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}
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}
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alg = kzalloc(sizeof(*alg), GFP_KERNEL);
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if (alg == NULL) {
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mutex_unlock(&rate_ctrl_mutex);
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return -ENOMEM;
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}
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alg->ops = ops;
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list_add_tail(&alg->list, &rate_ctrl_algs);
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mutex_unlock(&rate_ctrl_mutex);
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return 0;
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}
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EXPORT_SYMBOL(ieee80211_rate_control_register);
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void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
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{
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struct rate_control_alg *alg;
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mutex_lock(&rate_ctrl_mutex);
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list_for_each_entry(alg, &rate_ctrl_algs, list) {
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if (alg->ops == ops) {
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list_del(&alg->list);
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kfree(alg);
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break;
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}
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}
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mutex_unlock(&rate_ctrl_mutex);
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}
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EXPORT_SYMBOL(ieee80211_rate_control_unregister);
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static struct rate_control_ops *
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ieee80211_try_rate_control_ops_get(const char *name)
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{
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struct rate_control_alg *alg;
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struct rate_control_ops *ops = NULL;
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if (!name)
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return NULL;
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mutex_lock(&rate_ctrl_mutex);
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list_for_each_entry(alg, &rate_ctrl_algs, list) {
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if (!strcmp(alg->ops->name, name))
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if (try_module_get(alg->ops->module)) {
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ops = alg->ops;
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break;
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}
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}
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mutex_unlock(&rate_ctrl_mutex);
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return ops;
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}
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/* Get the rate control algorithm. */
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static struct rate_control_ops *
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ieee80211_rate_control_ops_get(const char *name)
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{
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struct rate_control_ops *ops;
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const char *alg_name;
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kparam_block_sysfs_write(ieee80211_default_rc_algo);
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if (!name)
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alg_name = ieee80211_default_rc_algo;
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else
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alg_name = name;
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ops = ieee80211_try_rate_control_ops_get(alg_name);
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if (!ops) {
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request_module("rc80211_%s", alg_name);
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ops = ieee80211_try_rate_control_ops_get(alg_name);
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}
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if (!ops && name)
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/* try default if specific alg requested but not found */
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ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
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/* try built-in one if specific alg requested but not found */
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if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
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ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
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kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
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return ops;
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}
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static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
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{
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module_put(ops->module);
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}
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#ifdef CONFIG_MAC80211_DEBUGFS
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static ssize_t rcname_read(struct file *file, char __user *userbuf,
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size_t count, loff_t *ppos)
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{
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struct rate_control_ref *ref = file->private_data;
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int len = strlen(ref->ops->name);
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return simple_read_from_buffer(userbuf, count, ppos,
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ref->ops->name, len);
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}
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static const struct file_operations rcname_ops = {
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.read = rcname_read,
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.open = simple_open,
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.llseek = default_llseek,
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};
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#endif
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static struct rate_control_ref *rate_control_alloc(const char *name,
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struct ieee80211_local *local)
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{
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struct dentry *debugfsdir = NULL;
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struct rate_control_ref *ref;
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ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
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if (!ref)
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goto fail_ref;
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ref->local = local;
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ref->ops = ieee80211_rate_control_ops_get(name);
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if (!ref->ops)
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goto fail_ops;
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#ifdef CONFIG_MAC80211_DEBUGFS
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debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
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local->debugfs.rcdir = debugfsdir;
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debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
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#endif
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ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
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if (!ref->priv)
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goto fail_priv;
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return ref;
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fail_priv:
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ieee80211_rate_control_ops_put(ref->ops);
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fail_ops:
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kfree(ref);
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fail_ref:
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return NULL;
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}
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static void rate_control_free(struct rate_control_ref *ctrl_ref)
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{
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ctrl_ref->ops->free(ctrl_ref->priv);
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#ifdef CONFIG_MAC80211_DEBUGFS
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debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
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ctrl_ref->local->debugfs.rcdir = NULL;
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#endif
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ieee80211_rate_control_ops_put(ctrl_ref->ops);
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kfree(ctrl_ref);
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}
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static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
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{
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struct sk_buff *skb = txrc->skb;
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
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__le16 fc;
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fc = hdr->frame_control;
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return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
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IEEE80211_TX_CTL_USE_MINRATE)) ||
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!ieee80211_is_data(fc);
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}
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static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
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struct ieee80211_supported_band *sband)
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{
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u8 i;
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if (basic_rates == 0)
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return; /* assume basic rates unknown and accept rate */
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if (*idx < 0)
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return;
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if (basic_rates & (1 << *idx))
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return; /* selected rate is a basic rate */
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for (i = *idx + 1; i <= sband->n_bitrates; i++) {
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if (basic_rates & (1 << i)) {
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*idx = i;
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return;
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}
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}
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/* could not find a basic rate; use original selection */
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}
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static inline s8
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rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
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struct ieee80211_sta *sta)
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{
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int i;
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for (i = 0; i < sband->n_bitrates; i++) {
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struct ieee80211_rate *srate = &sband->bitrates[i];
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if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
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(srate->bitrate == 55) || (srate->bitrate == 110))
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continue;
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if (rate_supported(sta, sband->band, i))
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return i;
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}
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/* No matching rate found */
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return 0;
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}
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bool rate_control_send_low(struct ieee80211_sta *sta,
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void *priv_sta,
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struct ieee80211_tx_rate_control *txrc)
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{
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struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
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struct ieee80211_supported_band *sband = txrc->sband;
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int mcast_rate;
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if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
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if ((sband->band != IEEE80211_BAND_2GHZ) ||
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!(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
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info->control.rates[0].idx =
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rate_lowest_index(txrc->sband, sta);
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else
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info->control.rates[0].idx =
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rate_lowest_non_cck_index(txrc->sband, sta);
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info->control.rates[0].count =
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(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
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1 : txrc->hw->max_rate_tries;
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if (!sta && txrc->bss) {
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mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
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if (mcast_rate > 0) {
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info->control.rates[0].idx = mcast_rate - 1;
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return true;
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}
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rc_send_low_broadcast(&info->control.rates[0].idx,
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txrc->bss_conf->basic_rates,
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sband);
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}
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return true;
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}
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return false;
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}
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EXPORT_SYMBOL(rate_control_send_low);
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static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
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int n_bitrates, u32 mask)
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{
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int j;
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/* See whether the selected rate or anything below it is allowed. */
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for (j = rate->idx; j >= 0; j--) {
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if (mask & (1 << j)) {
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/* Okay, found a suitable rate. Use it. */
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rate->idx = j;
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return true;
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}
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}
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/* Try to find a higher rate that would be allowed */
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for (j = rate->idx + 1; j < n_bitrates; j++) {
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if (mask & (1 << j)) {
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/* Okay, found a suitable rate. Use it. */
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rate->idx = j;
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return true;
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}
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}
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return false;
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}
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static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
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u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
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{
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int i, j;
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int ridx, rbit;
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ridx = rate->idx / 8;
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rbit = rate->idx % 8;
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/* sanity check */
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if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
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return false;
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/* See whether the selected rate or anything below it is allowed. */
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for (i = ridx; i >= 0; i--) {
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for (j = rbit; j >= 0; j--)
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if (mcs_mask[i] & BIT(j)) {
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rate->idx = i * 8 + j;
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return true;
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}
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rbit = 7;
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}
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/* Try to find a higher rate that would be allowed */
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ridx = (rate->idx + 1) / 8;
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rbit = (rate->idx + 1) % 8;
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for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
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for (j = rbit; j < 8; j++)
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if (mcs_mask[i] & BIT(j)) {
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rate->idx = i * 8 + j;
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return true;
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}
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rbit = 0;
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}
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return false;
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}
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static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
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struct ieee80211_tx_rate_control *txrc,
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u32 mask,
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u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
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{
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struct ieee80211_tx_rate alt_rate;
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/* handle HT rates */
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if (rate->flags & IEEE80211_TX_RC_MCS) {
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if (rate_idx_match_mcs_mask(rate, mcs_mask))
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return;
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/* also try the legacy rates. */
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alt_rate.idx = 0;
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/* keep protection flags */
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alt_rate.flags = rate->flags &
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(IEEE80211_TX_RC_USE_RTS_CTS |
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IEEE80211_TX_RC_USE_CTS_PROTECT |
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IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
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alt_rate.count = rate->count;
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if (rate_idx_match_legacy_mask(&alt_rate,
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txrc->sband->n_bitrates,
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mask)) {
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*rate = alt_rate;
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return;
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}
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} else {
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struct sk_buff *skb = txrc->skb;
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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__le16 fc;
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/* handle legacy rates */
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if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
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mask))
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return;
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/* if HT BSS, and we handle a data frame, also try HT rates */
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if (txrc->bss_conf->channel_type == NL80211_CHAN_NO_HT)
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return;
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fc = hdr->frame_control;
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if (!ieee80211_is_data(fc))
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return;
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alt_rate.idx = 0;
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/* keep protection flags */
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alt_rate.flags = rate->flags &
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(IEEE80211_TX_RC_USE_RTS_CTS |
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IEEE80211_TX_RC_USE_CTS_PROTECT |
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IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
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alt_rate.count = rate->count;
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alt_rate.flags |= IEEE80211_TX_RC_MCS;
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if ((txrc->bss_conf->channel_type == NL80211_CHAN_HT40MINUS) ||
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(txrc->bss_conf->channel_type == NL80211_CHAN_HT40PLUS))
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alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
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if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
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*rate = alt_rate;
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return;
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}
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}
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/*
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* Uh.. No suitable rate exists. This should not really happen with
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* sane TX rate mask configurations. However, should someone manage to
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* configure supported rates and TX rate mask in incompatible way,
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* allow the frame to be transmitted with whatever the rate control
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* selected.
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*/
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}
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void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
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struct sta_info *sta,
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struct ieee80211_tx_rate_control *txrc)
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{
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struct rate_control_ref *ref = sdata->local->rate_ctrl;
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void *priv_sta = NULL;
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struct ieee80211_sta *ista = NULL;
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struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
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int i;
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u32 mask;
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u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
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if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
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ista = &sta->sta;
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priv_sta = sta->rate_ctrl_priv;
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}
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for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
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info->control.rates[i].idx = -1;
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info->control.rates[i].flags = 0;
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info->control.rates[i].count = 0;
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}
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if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
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return;
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ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
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/*
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* Try to enforce the rateidx mask the user wanted. skip this if the
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* default mask (allow all rates) is used to save some processing for
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* the common case.
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*/
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mask = sdata->rc_rateidx_mask[info->band];
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memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
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sizeof(mcs_mask));
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if (mask != (1 << txrc->sband->n_bitrates) - 1) {
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if (sta) {
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/* Filter out rates that the STA does not support */
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mask &= sta->sta.supp_rates[info->band];
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for (i = 0; i < sizeof(mcs_mask); i++)
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mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
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}
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/*
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* Make sure the rate index selected for each TX rate is
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* included in the configured mask and change the rate indexes
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* if needed.
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*/
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for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
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/* Skip invalid rates */
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if (info->control.rates[i].idx < 0)
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break;
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rate_idx_match_mask(&info->control.rates[i], txrc,
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mask, mcs_mask);
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}
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}
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BUG_ON(info->control.rates[0].idx < 0);
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}
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int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
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const char *name)
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{
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struct rate_control_ref *ref;
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ASSERT_RTNL();
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if (local->open_count)
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return -EBUSY;
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if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
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if (WARN_ON(!local->ops->set_rts_threshold))
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return -EINVAL;
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return 0;
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}
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ref = rate_control_alloc(name, local);
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if (!ref) {
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wiphy_warn(local->hw.wiphy,
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"Failed to select rate control algorithm\n");
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return -ENOENT;
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}
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WARN_ON(local->rate_ctrl);
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local->rate_ctrl = ref;
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wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
|
|
ref->ops->name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void rate_control_deinitialize(struct ieee80211_local *local)
|
|
{
|
|
struct rate_control_ref *ref;
|
|
|
|
ref = local->rate_ctrl;
|
|
|
|
if (!ref)
|
|
return;
|
|
|
|
local->rate_ctrl = NULL;
|
|
rate_control_free(ref);
|
|
}
|
|
|