/* * Copyright 2002-2005, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright (c) 2006 Jiri Benc * * 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 #include #include #include #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 = 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 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_free(struct rate_control_ref *ctrl_ref) { 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_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); }