diff options
Diffstat (limited to 'net/mac80211/rate.c')
| -rw-r--r-- | net/mac80211/rate.c | 752 |
1 files changed, 752 insertions, 0 deletions
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c new file mode 100644 index 0000000..ab000ff --- /dev/null +++ b/net/mac80211/rate.c @@ -0,0 +1,752 @@ +/* + * 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 <linux/module.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 = CPTCFG_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(CPTCFG_MAC80211_RC_DEFAULT)) + ops = ieee80211_try_rate_control_ops_get(CPTCFG_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 CPTCFG_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 = simple_open, + .llseek = default_llseek, +}; +#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; + ref->local = local; + ref->ops = ieee80211_rate_control_ops_get(name); + if (!ref->ops) + goto fail_ops; + +#ifdef CPTCFG_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_free(struct rate_control_ref *ctrl_ref) +{ + ctrl_ref->ops->free(ctrl_ref->priv); + +#ifdef CPTCFG_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_use_min(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_TX_CTL_USE_MINRATE)) || + !ieee80211_is_data(fc); +} + +static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, + struct ieee80211_supported_band *sband) +{ + 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 <= sband->n_bitrates; i++) { + if (basic_rates & (1 << i)) { + *idx = i; + return; + } + } + + /* could not find a basic rate; use original selection */ +} + +static inline s8 +rate_lowest_non_cck_index(struct ieee80211_supported_band *sband, + struct ieee80211_sta *sta) +{ + int i; + + for (i = 0; i < sband->n_bitrates; i++) { + struct ieee80211_rate *srate = &sband->bitrates[i]; + if ((srate->bitrate == 10) || (srate->bitrate == 20) || + (srate->bitrate == 55) || (srate->bitrate == 110)) + continue; + + if (rate_supported(sta, sband->band, i)) + return i; + } + + /* No matching rate found */ + return 0; +} + +static void __rate_control_send_low(struct ieee80211_hw *hw, + struct ieee80211_supported_band *sband, + struct ieee80211_sta *sta, + struct ieee80211_tx_info *info) +{ + if ((sband->band != IEEE80211_BAND_2GHZ) || + !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE)) + info->control.rates[0].idx = rate_lowest_index(sband, sta); + else + info->control.rates[0].idx = + rate_lowest_non_cck_index(sband, sta); + + info->control.rates[0].count = + (info->flags & IEEE80211_TX_CTL_NO_ACK) ? + 1 : hw->max_rate_tries; + + info->control.skip_table = 1; +} + + +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); + struct ieee80211_supported_band *sband = txrc->sband; + int mcast_rate; + + if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) { + __rate_control_send_low(txrc->hw, sband, sta, info); + + if (!sta && txrc->bss) { + mcast_rate = txrc->bss_conf->mcast_rate[sband->band]; + if (mcast_rate > 0) { + info->control.rates[0].idx = mcast_rate - 1; + return true; + } + + rc_send_low_broadcast(&info->control.rates[0].idx, + txrc->bss_conf->basic_rates, + sband); + } + return true; + } + return false; +} +EXPORT_SYMBOL(rate_control_send_low); + +static bool rate_idx_match_legacy_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 true; + } + } + + /* 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 true; + } + } + return false; +} + +static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate, + u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) +{ + int i, j; + int ridx, rbit; + + ridx = rate->idx / 8; + rbit = rate->idx % 8; + + /* sanity check */ + if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN) + return false; + + /* See whether the selected rate or anything below it is allowed. */ + for (i = ridx; i >= 0; i--) { + for (j = rbit; j >= 0; j--) + if (mcs_mask[i] & BIT(j)) { + rate->idx = i * 8 + j; + return true; + } + rbit = 7; + } + + /* Try to find a higher rate that would be allowed */ + ridx = (rate->idx + 1) / 8; + rbit = (rate->idx + 1) % 8; + + for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) { + for (j = rbit; j < 8; j++) + if (mcs_mask[i] & BIT(j)) { + rate->idx = i * 8 + j; + return true; + } + rbit = 0; + } + return false; +} + + + +static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, + struct ieee80211_supported_band *sband, + enum nl80211_chan_width chan_width, + u32 mask, + u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]) +{ + struct ieee80211_tx_rate alt_rate; + + /* handle HT rates */ + if (rate->flags & IEEE80211_TX_RC_MCS) { + if (rate_idx_match_mcs_mask(rate, mcs_mask)) + return; + + /* also try the legacy rates. */ + alt_rate.idx = 0; + /* keep protection flags */ + alt_rate.flags = rate->flags & + (IEEE80211_TX_RC_USE_RTS_CTS | + IEEE80211_TX_RC_USE_CTS_PROTECT | + IEEE80211_TX_RC_USE_SHORT_PREAMBLE); + alt_rate.count = rate->count; + if (rate_idx_match_legacy_mask(&alt_rate, + sband->n_bitrates, mask)) { + *rate = alt_rate; + return; + } + } else { + /* handle legacy rates */ + if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask)) + return; + + /* if HT BSS, and we handle a data frame, also try HT rates */ + if (chan_width == NL80211_CHAN_WIDTH_20_NOHT) + return; + + alt_rate.idx = 0; + /* keep protection flags */ + alt_rate.flags = rate->flags & + (IEEE80211_TX_RC_USE_RTS_CTS | + IEEE80211_TX_RC_USE_CTS_PROTECT | + IEEE80211_TX_RC_USE_SHORT_PREAMBLE); + alt_rate.count = rate->count; + + alt_rate.flags |= IEEE80211_TX_RC_MCS; + + if (chan_width == NL80211_CHAN_WIDTH_40) + alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH; + + if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) { + *rate = alt_rate; + 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. + */ +} + +static void rate_fixup_ratelist(struct ieee80211_vif *vif, + struct ieee80211_supported_band *sband, + struct ieee80211_tx_info *info, + struct ieee80211_tx_rate *rates, + int max_rates) +{ + struct ieee80211_rate *rate; + bool inval = false; + int i; + + /* + * Set up the RTS/CTS rate as the fastest basic rate + * that is not faster than the data rate unless there + * is no basic rate slower than the data rate, in which + * case we pick the slowest basic rate + * + * XXX: Should this check all retry rates? + */ + if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) { + u32 basic_rates = vif->bss_conf.basic_rates; + s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0; + + rate = &sband->bitrates[rates[0].idx]; + + for (i = 0; i < sband->n_bitrates; i++) { + /* must be a basic rate */ + if (!(basic_rates & BIT(i))) + continue; + /* must not be faster than the data rate */ + if (sband->bitrates[i].bitrate > rate->bitrate) + continue; + /* maximum */ + if (sband->bitrates[baserate].bitrate < + sband->bitrates[i].bitrate) + baserate = i; + } + + info->control.rts_cts_rate_idx = baserate; + } + + for (i = 0; i < max_rates; i++) { + /* + * make sure there's no valid rate following + * an invalid one, just in case drivers don't + * take the API seriously to stop at -1. + */ + if (inval) { + rates[i].idx = -1; + continue; + } + if (rates[i].idx < 0) { + inval = true; + continue; + } + + /* + * For now assume MCS is already set up correctly, this + * needs to be fixed. + */ + if (rates[i].flags & IEEE80211_TX_RC_MCS) { + WARN_ON(rates[i].idx > 76); + + if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) && + info->control.use_cts_prot) + rates[i].flags |= + IEEE80211_TX_RC_USE_CTS_PROTECT; + continue; + } + + if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) { + WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9); + continue; + } + + /* set up RTS protection if desired */ + if (info->control.use_rts) { + rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS; + info->control.use_cts_prot = false; + } + + /* RC is busted */ + if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) { + rates[i].idx = -1; + continue; + } + + rate = &sband->bitrates[rates[i].idx]; + + /* set up short preamble */ + if (info->control.short_preamble && + rate->flags & IEEE80211_RATE_SHORT_PREAMBLE) + rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE; + + /* set up G protection */ + if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) && + info->control.use_cts_prot && + rate->flags & IEEE80211_RATE_ERP_G) + rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT; + } +} + + +static void rate_control_fill_sta_table(struct ieee80211_sta *sta, + struct ieee80211_tx_info *info, + struct ieee80211_tx_rate *rates, + int max_rates) +{ + struct ieee80211_sta_rates *ratetbl = NULL; + int i; + + if (sta && !info->control.skip_table) + ratetbl = rcu_dereference(sta->rates); + + /* Fill remaining rate slots with data from the sta rate table. */ + max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE); + for (i = 0; i < max_rates; i++) { + if (i < ARRAY_SIZE(info->control.rates) && + info->control.rates[i].idx >= 0 && + info->control.rates[i].count) { + if (rates != info->control.rates) + rates[i] = info->control.rates[i]; + } else if (ratetbl) { + rates[i].idx = ratetbl->rate[i].idx; + rates[i].flags = ratetbl->rate[i].flags; + if (info->control.use_rts) + rates[i].count = ratetbl->rate[i].count_rts; + else if (info->control.use_cts_prot) + rates[i].count = ratetbl->rate[i].count_cts; + else + rates[i].count = ratetbl->rate[i].count; + } else { + rates[i].idx = -1; + rates[i].count = 0; + } + + if (rates[i].idx < 0 || !rates[i].count) + break; + } +} + +static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata, + struct ieee80211_sta *sta, + struct ieee80211_supported_band *sband, + struct ieee80211_tx_info *info, + struct ieee80211_tx_rate *rates, + int max_rates) +{ + enum nl80211_chan_width chan_width; + u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN]; + bool has_mcs_mask; + u32 mask; + int i; + + /* + * 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]; + has_mcs_mask = sdata->rc_has_mcs_mask[info->band]; + if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask) + return; + + if (has_mcs_mask) + memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band], + sizeof(mcs_mask)); + else + memset(mcs_mask, 0xff, sizeof(mcs_mask)); + + if (sta) { + /* Filter out rates that the STA does not support */ + mask &= sta->supp_rates[info->band]; + for (i = 0; i < sizeof(mcs_mask); i++) + mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i]; + } + + /* + * Make sure the rate index selected for each TX rate is + * included in the configured mask and change the rate indexes + * if needed. + */ + chan_width = sdata->vif.bss_conf.chandef.width; + for (i = 0; i < max_rates; i++) { + /* Skip invalid rates */ + if (rates[i].idx < 0) + break; + + rate_idx_match_mask(&rates[i], sband, chan_width, mask, + mcs_mask); + } +} + +void ieee80211_get_tx_rates(struct ieee80211_vif *vif, + struct ieee80211_sta *sta, + struct sk_buff *skb, + struct ieee80211_tx_rate *dest, + int max_rates) +{ + struct ieee80211_sub_if_data *sdata; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_supported_band *sband; + + rate_control_fill_sta_table(sta, info, dest, max_rates); + + if (!vif) + return; + + sdata = vif_to_sdata(vif); + sband = sdata->local->hw.wiphy->bands[info->band]; + + if (ieee80211_is_data(hdr->frame_control)) + rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates); + + if (dest[0].idx < 0) + __rate_control_send_low(&sdata->local->hw, sband, sta, info); + + if (sta) + rate_fixup_ratelist(vif, sband, info, dest, max_rates); +} +EXPORT_SYMBOL(ieee80211_get_tx_rates); + +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; + + if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) { + 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 = 0; + } + + if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) + return; + + ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); + + if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE) + return; + + ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb, + info->control.rates, + ARRAY_SIZE(info->control.rates)); +} + +int rate_control_set_rates(struct ieee80211_hw *hw, + struct ieee80211_sta *pubsta, + struct ieee80211_sta_rates *rates) +{ + struct ieee80211_sta_rates *old; + + /* + * mac80211 guarantees that this function will not be called + * concurrently, so the following RCU access is safe, even without + * extra locking. This can not be checked easily, so we just set + * the condition to true. + */ + old = rcu_dereference_protected(pubsta->rates, true); + rcu_assign_pointer(pubsta->rates, rates); + if (old) + kfree_rcu(old, rcu_head); + + return 0; +} +EXPORT_SYMBOL(rate_control_set_rates); + +int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, + const char *name) +{ + struct rate_control_ref *ref; + + 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; + } + + WARN_ON(local->rate_ctrl); + local->rate_ctrl = ref; + + 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); +} + |