[MAC80211]: Add mac80211 wireless stack.

Add mac80211, the IEEE 802.11 software MAC layer.

Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 361 insertions, 0 deletions

diff --git a/net/mac80211/rc80211_simple.c b/net/mac80211/rc80211_simple.c
new file mode 100644
index 00000000000..68bddaeee00
--- /dev/null
+++ b/net/mac80211/rc80211_simple.c
@@ -0,0 +1,361 @@
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ *
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+#include <linux/compiler.h>
+
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "ieee80211_rate.h"
+
+
+/* This is a minimal implementation of TX rate controlling that can be used
+ * as the default when no improved mechanisms are available. */
+
+
+#define RATE_CONTROL_EMERG_DEC 2
+#define RATE_CONTROL_INTERVAL (HZ / 20)
+#define RATE_CONTROL_MIN_TX 10
+
+MODULE_ALIAS("rc80211_default");
+
+static void rate_control_rate_inc(struct ieee80211_local *local,
+				  struct sta_info *sta)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_hw_mode *mode;
+	int i = sta->txrate;
+	int maxrate;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+	if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
+		/* forced unicast rate - do not change STA rate */
+		return;
+	}
+
+	mode = local->oper_hw_mode;
+	maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
+
+	if (i > mode->num_rates)
+		i = mode->num_rates - 2;
+
+	while (i + 1 < mode->num_rates) {
+		i++;
+		if (sta->supp_rates & BIT(i) &&
+		    mode->rates[i].flags & IEEE80211_RATE_SUPPORTED &&
+		    (maxrate < 0 || i <= maxrate)) {
+			sta->txrate = i;
+			break;
+		}
+	}
+}
+
+
+static void rate_control_rate_dec(struct ieee80211_local *local,
+				  struct sta_info *sta)
+{
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_hw_mode *mode;
+	int i = sta->txrate;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+	if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
+		/* forced unicast rate - do not change STA rate */
+		return;
+	}
+
+	mode = local->oper_hw_mode;
+	if (i > mode->num_rates)
+		i = mode->num_rates;
+
+	while (i > 0) {
+		i--;
+		if (sta->supp_rates & BIT(i) &&
+		    mode->rates[i].flags & IEEE80211_RATE_SUPPORTED) {
+			sta->txrate = i;
+			break;
+		}
+	}
+}
+
+
+static struct ieee80211_rate *
+rate_control_lowest_rate(struct ieee80211_local *local,
+			 struct ieee80211_hw_mode *mode)
+{
+	int i;
+
+	for (i = 0; i < mode->num_rates; i++) {
+		struct ieee80211_rate *rate = &mode->rates[i];
+
+		if (rate->flags & IEEE80211_RATE_SUPPORTED)
+			return rate;
+	}
+
+	printk(KERN_DEBUG "rate_control_lowest_rate - no supported rates "
+	       "found\n");
+	return &mode->rates[0];
+}
+
+
+struct global_rate_control {
+	int dummy;
+};
+
+struct sta_rate_control {
+	unsigned long last_rate_change;
+	u32 tx_num_failures;
+	u32 tx_num_xmit;
+
+	unsigned long avg_rate_update;
+	u32 tx_avg_rate_sum;
+	u32 tx_avg_rate_num;
+};
+
+
+static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
+					  struct sk_buff *skb,
+					  struct ieee80211_tx_status *status)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct sta_info *sta;
+	struct sta_rate_control *srctrl;
+
+	sta = sta_info_get(local, hdr->addr1);
+
+	if (!sta)
+	    return;
+
+	srctrl = sta->rate_ctrl_priv;
+	srctrl->tx_num_xmit++;
+	if (status->excessive_retries) {
+		sta->antenna_sel_tx = sta->antenna_sel_tx == 1 ? 2 : 1;
+		sta->antenna_sel_rx = sta->antenna_sel_rx == 1 ? 2 : 1;
+		if (local->sta_antenna_sel == STA_ANTENNA_SEL_SW_CTRL_DEBUG) {
+			printk(KERN_DEBUG "%s: " MAC_FMT " TX antenna --> %d "
+			       "RX antenna --> %d (@%lu)\n",
+			       dev->name, MAC_ARG(hdr->addr1),
+			       sta->antenna_sel_tx, sta->antenna_sel_rx, jiffies);
+		}
+		srctrl->tx_num_failures++;
+		sta->tx_retry_failed++;
+		sta->tx_num_consecutive_failures++;
+		sta->tx_num_mpdu_fail++;
+	} else {
+		sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
+		sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
+		sta->last_ack_rssi[2] = status->ack_signal;
+		sta->tx_num_consecutive_failures = 0;
+		sta->tx_num_mpdu_ok++;
+	}
+	sta->tx_retry_count += status->retry_count;
+	sta->tx_num_mpdu_fail += status->retry_count;
+
+	if (time_after(jiffies,
+		       srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
+		srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
+		u32 per_failed;
+		srctrl->last_rate_change = jiffies;
+
+		per_failed = (100 * sta->tx_num_mpdu_fail) /
+			(sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
+		/* TODO: calculate average per_failed to make adjusting
+		 * parameters easier */
+#if 0
+		if (net_ratelimit()) {
+			printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
+			       sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
+			       per_failed);
+		}
+#endif
+
+		if (per_failed > local->rate_ctrl_num_down) {
+			rate_control_rate_dec(local, sta);
+		} else if (per_failed < local->rate_ctrl_num_up) {
+			rate_control_rate_inc(local, sta);
+		}
+		srctrl->tx_avg_rate_sum += status->control.rate->rate;
+		srctrl->tx_avg_rate_num++;
+		srctrl->tx_num_failures = 0;
+		srctrl->tx_num_xmit = 0;
+	} else if (sta->tx_num_consecutive_failures >=
+		   RATE_CONTROL_EMERG_DEC) {
+		rate_control_rate_dec(local, sta);
+	}
+
+	if (srctrl->avg_rate_update + 60 * HZ < jiffies) {
+		srctrl->avg_rate_update = jiffies;
+		if (srctrl->tx_avg_rate_num > 0) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+			printk(KERN_DEBUG "%s: STA " MAC_FMT " Average rate: "
+			       "%d (%d/%d)\n",
+			       dev->name, MAC_ARG(sta->addr),
+			       srctrl->tx_avg_rate_sum /
+			       srctrl->tx_avg_rate_num,
+			       srctrl->tx_avg_rate_sum,
+			       srctrl->tx_avg_rate_num);
+#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
+			srctrl->tx_avg_rate_sum = 0;
+			srctrl->tx_avg_rate_num = 0;
+		}
+	}
+
+	sta_info_put(sta);
+}
+
+
+static struct ieee80211_rate *
+rate_control_simple_get_rate(void *priv, struct net_device *dev,
+			     struct sk_buff *skb,
+			     struct rate_control_extra *extra)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct ieee80211_sub_if_data *sdata;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+	struct ieee80211_hw_mode *mode = extra->mode;
+	struct sta_info *sta;
+	int rateidx, nonerp_idx;
+	u16 fc;
+
+	memset(extra, 0, sizeof(*extra));
+
+	fc = le16_to_cpu(hdr->frame_control);
+	if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
+	    (hdr->addr1[0] & 0x01)) {
+		/* Send management frames and broadcast/multicast data using
+		 * lowest rate. */
+		/* TODO: this could probably be improved.. */
+		return rate_control_lowest_rate(local, mode);
+	}
+
+	sta = sta_info_get(local, hdr->addr1);
+
+	if (!sta)
+		return rate_control_lowest_rate(local, mode);
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
+		sta->txrate = sdata->bss->force_unicast_rateidx;
+
+	rateidx = sta->txrate;
+
+	if (rateidx >= mode->num_rates)
+		rateidx = mode->num_rates - 1;
+
+	sta->last_txrate = rateidx;
+	nonerp_idx = rateidx;
+	while (nonerp_idx > 0 &&
+	       ((mode->rates[nonerp_idx].flags & IEEE80211_RATE_ERP) ||
+		!(mode->rates[nonerp_idx].flags & IEEE80211_RATE_SUPPORTED) ||
+		!(sta->supp_rates & BIT(nonerp_idx))))
+		nonerp_idx--;
+	extra->nonerp = &mode->rates[nonerp_idx];
+
+	sta_info_put(sta);
+
+	return &mode->rates[rateidx];
+}
+
+
+static void rate_control_simple_rate_init(void *priv, void *priv_sta,
+					  struct ieee80211_local *local,
+					  struct sta_info *sta)
+{
+	struct ieee80211_hw_mode *mode;
+	int i;
+	sta->txrate = 0;
+	mode = local->oper_hw_mode;
+	/* TODO: what is a good starting rate for STA? About middle? Maybe not
+	 * the lowest or the highest rate.. Could consider using RSSI from
+	 * previous packets? Need to have IEEE 802.1X auth succeed immediately
+	 * after assoc.. */
+	for (i = 0; i < mode->num_rates; i++) {
+		if ((sta->supp_rates & BIT(i)) &&
+		    (mode->rates[i].flags & IEEE80211_RATE_SUPPORTED))
+			sta->txrate = i;
+	}
+}
+
+
+static void * rate_control_simple_alloc(struct ieee80211_local *local)
+{
+	struct global_rate_control *rctrl;
+
+	rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
+
+	return rctrl;
+}
+
+
+static void rate_control_simple_free(void *priv)
+{
+	struct global_rate_control *rctrl = priv;
+	kfree(rctrl);
+}
+
+
+static void rate_control_simple_clear(void *priv)
+{
+}
+
+
+static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
+{
+	struct sta_rate_control *rctrl;
+
+	rctrl = kzalloc(sizeof(*rctrl), gfp);
+
+	return rctrl;
+}
+
+
+static void rate_control_simple_free_sta(void *priv, void *priv_sta)
+{
+	struct sta_rate_control *rctrl = priv_sta;
+	kfree(rctrl);
+}
+
+
+static struct rate_control_ops rate_control_simple = {
+	.module = THIS_MODULE,
+	.name = "simple",
+	.tx_status = rate_control_simple_tx_status,
+	.get_rate = rate_control_simple_get_rate,
+	.rate_init = rate_control_simple_rate_init,
+	.clear = rate_control_simple_clear,
+	.alloc = rate_control_simple_alloc,
+	.free = rate_control_simple_free,
+	.alloc_sta = rate_control_simple_alloc_sta,
+	.free_sta = rate_control_simple_free_sta,
+};
+
+
+static int __init rate_control_simple_init(void)
+{
+	return ieee80211_rate_control_register(&rate_control_simple);
+}
+
+
+static void __exit rate_control_simple_exit(void)
+{
+	ieee80211_rate_control_unregister(&rate_control_simple);
+}
+
+
+module_init(rate_control_simple_init);
+module_exit(rate_control_simple_exit);
+
+MODULE_DESCRIPTION("Simple rate control algorithm for ieee80211");
+MODULE_LICENSE("GPL");