| /* |
| * Copyright 2002-2005, Instant802 Networks, Inc. |
| * Copyright 2005-2006, Devicescape Software, Inc. |
| * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz> |
| * |
| * 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/kernel.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/slab.h> |
| #include "rate.h" |
| #include "ieee80211_i.h" |
| #include "debugfs.h" |
| |
| struct rate_control_alg { |
| struct list_head list; |
| struct rate_control_ops *ops; |
| }; |
| |
| static LIST_HEAD(rate_ctrl_algs); |
| static DEFINE_MUTEX(rate_ctrl_mutex); |
| |
| static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; |
| module_param(ieee80211_default_rc_algo, charp, 0644); |
| MODULE_PARM_DESC(ieee80211_default_rc_algo, |
| "Default rate control algorithm for mac80211 to use"); |
| |
| int ieee80211_rate_control_register(struct rate_control_ops *ops) |
| { |
| struct rate_control_alg *alg; |
| |
| if (!ops->name) |
| return -EINVAL; |
| |
| mutex_lock(&rate_ctrl_mutex); |
| list_for_each_entry(alg, &rate_ctrl_algs, list) { |
| if (!strcmp(alg->ops->name, ops->name)) { |
| /* don't register an algorithm twice */ |
| WARN_ON(1); |
| mutex_unlock(&rate_ctrl_mutex); |
| return -EALREADY; |
| } |
| } |
| |
| alg = kzalloc(sizeof(*alg), GFP_KERNEL); |
| if (alg == NULL) { |
| mutex_unlock(&rate_ctrl_mutex); |
| return -ENOMEM; |
| } |
| alg->ops = ops; |
| |
| list_add_tail(&alg->list, &rate_ctrl_algs); |
| mutex_unlock(&rate_ctrl_mutex); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(ieee80211_rate_control_register); |
| |
| void ieee80211_rate_control_unregister(struct rate_control_ops *ops) |
| { |
| struct rate_control_alg *alg; |
| |
| mutex_lock(&rate_ctrl_mutex); |
| list_for_each_entry(alg, &rate_ctrl_algs, list) { |
| if (alg->ops == ops) { |
| list_del(&alg->list); |
| kfree(alg); |
| break; |
| } |
| } |
| mutex_unlock(&rate_ctrl_mutex); |
| } |
| EXPORT_SYMBOL(ieee80211_rate_control_unregister); |
| |
| static struct rate_control_ops * |
| ieee80211_try_rate_control_ops_get(const char *name) |
| { |
| struct rate_control_alg *alg; |
| struct rate_control_ops *ops = NULL; |
| |
| if (!name) |
| return NULL; |
| |
| mutex_lock(&rate_ctrl_mutex); |
| list_for_each_entry(alg, &rate_ctrl_algs, list) { |
| if (!strcmp(alg->ops->name, name)) |
| if (try_module_get(alg->ops->module)) { |
| ops = alg->ops; |
| break; |
| } |
| } |
| mutex_unlock(&rate_ctrl_mutex); |
| return ops; |
| } |
| |
| /* Get the rate control algorithm. */ |
| static struct rate_control_ops * |
| ieee80211_rate_control_ops_get(const char *name) |
| { |
| struct rate_control_ops *ops; |
| const char *alg_name; |
| |
| kparam_block_sysfs_write(ieee80211_default_rc_algo); |
| if (!name) |
| alg_name = ieee80211_default_rc_algo; |
| else |
| alg_name = name; |
| |
| ops = ieee80211_try_rate_control_ops_get(alg_name); |
| if (!ops) { |
| request_module("rc80211_%s", alg_name); |
| ops = ieee80211_try_rate_control_ops_get(alg_name); |
| } |
| if (!ops && name) |
| /* try default if specific alg requested but not found */ |
| ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); |
| |
| /* try built-in one if specific alg requested but not found */ |
| if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) |
| ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); |
| kparam_unblock_sysfs_write(ieee80211_default_rc_algo); |
| |
| return ops; |
| } |
| |
| static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) |
| { |
| module_put(ops->module); |
| } |
| |
| #ifdef CONFIG_MAC80211_DEBUGFS |
| static ssize_t rcname_read(struct file *file, char __user *userbuf, |
| size_t count, loff_t *ppos) |
| { |
| struct rate_control_ref *ref = file->private_data; |
| int len = strlen(ref->ops->name); |
| |
| return simple_read_from_buffer(userbuf, count, ppos, |
| ref->ops->name, len); |
| } |
| |
| static const struct file_operations rcname_ops = { |
| .read = rcname_read, |
| .open = mac80211_open_file_generic, |
| }; |
| #endif |
| |
| static struct rate_control_ref *rate_control_alloc(const char *name, |
| struct ieee80211_local *local) |
| { |
| struct dentry *debugfsdir = NULL; |
| struct rate_control_ref *ref; |
| |
| ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); |
| if (!ref) |
| goto fail_ref; |
| kref_init(&ref->kref); |
| ref->local = local; |
| ref->ops = ieee80211_rate_control_ops_get(name); |
| if (!ref->ops) |
| goto fail_ops; |
| |
| #ifdef CONFIG_MAC80211_DEBUGFS |
| debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); |
| local->debugfs.rcdir = debugfsdir; |
| debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); |
| #endif |
| |
| ref->priv = ref->ops->alloc(&local->hw, debugfsdir); |
| if (!ref->priv) |
| goto fail_priv; |
| return ref; |
| |
| fail_priv: |
| ieee80211_rate_control_ops_put(ref->ops); |
| fail_ops: |
| kfree(ref); |
| fail_ref: |
| return NULL; |
| } |
| |
| static void rate_control_release(struct kref *kref) |
| { |
| struct rate_control_ref *ctrl_ref; |
| |
| ctrl_ref = container_of(kref, struct rate_control_ref, kref); |
| ctrl_ref->ops->free(ctrl_ref->priv); |
| |
| #ifdef CONFIG_MAC80211_DEBUGFS |
| debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); |
| ctrl_ref->local->debugfs.rcdir = NULL; |
| #endif |
| |
| ieee80211_rate_control_ops_put(ctrl_ref->ops); |
| kfree(ctrl_ref); |
| } |
| |
| static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc) |
| { |
| struct sk_buff *skb = txrc->skb; |
| struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; |
| struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
| __le16 fc; |
| |
| fc = hdr->frame_control; |
| |
| return (info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc); |
| } |
| |
| static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx) |
| { |
| u8 i; |
| |
| if (basic_rates == 0) |
| return; /* assume basic rates unknown and accept rate */ |
| if (*idx < 0) |
| return; |
| if (basic_rates & (1 << *idx)) |
| return; /* selected rate is a basic rate */ |
| |
| for (i = *idx + 1; i <= max_rate_idx; i++) { |
| if (basic_rates & (1 << i)) { |
| *idx = i; |
| return; |
| } |
| } |
| |
| /* could not find a basic rate; use original selection */ |
| } |
| |
| bool rate_control_send_low(struct ieee80211_sta *sta, |
| void *priv_sta, |
| struct ieee80211_tx_rate_control *txrc) |
| { |
| struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
| |
| if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) { |
| info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta); |
| info->control.rates[0].count = |
| (info->flags & IEEE80211_TX_CTL_NO_ACK) ? |
| 1 : txrc->hw->max_rate_tries; |
| if (!sta && txrc->ap) |
| rc_send_low_broadcast(&info->control.rates[0].idx, |
| txrc->bss_conf->basic_rates, |
| txrc->sband->n_bitrates); |
| return true; |
| } |
| return false; |
| } |
| EXPORT_SYMBOL(rate_control_send_low); |
| |
| static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, |
| int n_bitrates, u32 mask) |
| { |
| int j; |
| |
| /* See whether the selected rate or anything below it is allowed. */ |
| for (j = rate->idx; j >= 0; j--) { |
| if (mask & (1 << j)) { |
| /* Okay, found a suitable rate. Use it. */ |
| rate->idx = j; |
| return; |
| } |
| } |
| |
| /* Try to find a higher rate that would be allowed */ |
| for (j = rate->idx + 1; j < n_bitrates; j++) { |
| if (mask & (1 << j)) { |
| /* Okay, found a suitable rate. Use it. */ |
| rate->idx = j; |
| return; |
| } |
| } |
| |
| /* |
| * Uh.. No suitable rate exists. This should not really happen with |
| * sane TX rate mask configurations. However, should someone manage to |
| * configure supported rates and TX rate mask in incompatible way, |
| * allow the frame to be transmitted with whatever the rate control |
| * selected. |
| */ |
| } |
| |
| void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, |
| struct sta_info *sta, |
| struct ieee80211_tx_rate_control *txrc) |
| { |
| struct rate_control_ref *ref = sdata->local->rate_ctrl; |
| void *priv_sta = NULL; |
| struct ieee80211_sta *ista = NULL; |
| struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
| int i; |
| u32 mask; |
| |
| if (sta) { |
| ista = &sta->sta; |
| priv_sta = sta->rate_ctrl_priv; |
| } |
| |
| for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
| info->control.rates[i].idx = -1; |
| info->control.rates[i].flags = 0; |
| info->control.rates[i].count = 1; |
| } |
| |
| if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) |
| return; |
| |
| ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); |
| |
| /* |
| * Try to enforce the rateidx mask the user wanted. skip this if the |
| * default mask (allow all rates) is used to save some processing for |
| * the common case. |
| */ |
| mask = sdata->rc_rateidx_mask[info->band]; |
| if (mask != (1 << txrc->sband->n_bitrates) - 1) { |
| if (sta) { |
| /* Filter out rates that the STA does not support */ |
| mask &= sta->sta.supp_rates[info->band]; |
| } |
| /* |
| * Make sure the rate index selected for each TX rate is |
| * included in the configured mask and change the rate indexes |
| * if needed. |
| */ |
| for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
| /* Rate masking supports only legacy rates for now */ |
| if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) |
| continue; |
| rate_idx_match_mask(&info->control.rates[i], |
| txrc->sband->n_bitrates, mask); |
| } |
| } |
| |
| BUG_ON(info->control.rates[0].idx < 0); |
| } |
| |
| struct rate_control_ref *rate_control_get(struct rate_control_ref *ref) |
| { |
| kref_get(&ref->kref); |
| return ref; |
| } |
| |
| void rate_control_put(struct rate_control_ref *ref) |
| { |
| kref_put(&ref->kref, rate_control_release); |
| } |
| |
| int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, |
| const char *name) |
| { |
| struct rate_control_ref *ref, *old; |
| |
| ASSERT_RTNL(); |
| |
| if (local->open_count) |
| return -EBUSY; |
| |
| if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { |
| if (WARN_ON(!local->ops->set_rts_threshold)) |
| return -EINVAL; |
| return 0; |
| } |
| |
| ref = rate_control_alloc(name, local); |
| if (!ref) { |
| wiphy_warn(local->hw.wiphy, |
| "Failed to select rate control algorithm\n"); |
| return -ENOENT; |
| } |
| |
| old = local->rate_ctrl; |
| local->rate_ctrl = ref; |
| if (old) { |
| rate_control_put(old); |
| sta_info_flush(local, NULL); |
| } |
| |
| 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_put(ref); |
| } |
| |