1 files changed, 415 insertions, 0 deletions
diff --git a/net/mac80211/rate.c b/net/mac80211/rate.c
new file mode 100644
index 00000000..816590b0
--- /dev/null
+++ b/net/mac80211/rate.c
@@ -0,0 +1,415 @@
+/*
+ * 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,
+	.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;
+	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,
+				  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 */
+}
+
+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(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->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 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 = 0;
+	}
+
+	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++) {
+			/* Skip invalid rates */
+			if (info->control.rates[i].idx < 0)
+				break;
+			/* 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);
+}
+