1 files changed, 347 insertions, 0 deletions

diff --git a/package/d80211/src/ieee80211_scan.c b/package/d80211/src/ieee80211_scan.c
new file mode 100644
index 0000000000..6db66f0831
--- /dev/null
+++ b/package/d80211/src/ieee80211_scan.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright 2002-2004, Instant802 Networks, 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/netdevice.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+
+#include <net/d80211.h>
+#include "ieee80211_i.h"
+#include "ieee80211_rate.h"
+
+
+/* Maximum number of seconds to wait for the traffic load to get below
+ * threshold before forcing a passive scan. */
+#define MAX_SCAN_WAIT 60
+/* Threshold (pkts/sec TX or RX) for delaying passive scan */
+#define SCAN_TXRX_THRESHOLD 75
+
+static void get_channel_params(struct ieee80211_local *local, int channel,
+				struct ieee80211_hw_modes **mode,
+				struct ieee80211_channel **chan)
+{
+	int m;
+
+	for (m = 0; m < local->hw.num_modes; m++) {
+		*mode = &local->hw.modes[m];
+		if ((*mode)->mode == local->hw.conf.phymode)
+			break;
+	}
+	local->scan.mode_idx = m;
+	local->scan.chan_idx = 0;
+	do {
+		*chan = &(*mode)->channels[local->scan.chan_idx];
+		if ((*chan)->chan == channel) {
+			return;
+		}
+		local->scan.chan_idx++;
+	} while (local->scan.chan_idx < (*mode)->num_channels);
+	*chan = NULL;
+}
+
+
+static void next_chan_same_mode(struct ieee80211_local *local,
+				struct ieee80211_hw_modes **mode,
+				struct ieee80211_channel **chan)
+{
+	int m, prev;
+
+	for (m = 0; m < local->hw.num_modes; m++) {
+		*mode = &local->hw.modes[m];
+		if ((*mode)->mode == local->hw.conf.phymode)
+			break;
+	}
+	local->scan.mode_idx = m;
+
+	/* Select next channel - scan only channels marked with W_SCAN flag */
+	prev = local->scan.chan_idx;
+	do {
+		local->scan.chan_idx++;
+		if (local->scan.chan_idx >= (*mode)->num_channels)
+			local->scan.chan_idx = 0;
+		*chan = &(*mode)->channels[local->scan.chan_idx];
+		if ((*chan)->flag & IEEE80211_CHAN_W_SCAN)
+			break;
+	} while (local->scan.chan_idx != prev);
+}
+
+
+static void next_chan_all_modes(struct ieee80211_local *local,
+				struct ieee80211_hw_modes **mode,
+				struct ieee80211_channel **chan)
+{
+	int prev, prev_m;
+
+	if (local->scan.mode_idx >= local->hw.num_modes) {
+		local->scan.mode_idx = 0;
+		local->scan.chan_idx = 0;
+	}
+
+	/* Select next channel - scan only channels marked with W_SCAN flag */
+	prev = local->scan.chan_idx;
+	prev_m = local->scan.mode_idx;
+	do {
+		*mode = &local->hw.modes[local->scan.mode_idx];
+		local->scan.chan_idx++;
+		if (local->scan.chan_idx >= (*mode)->num_channels) {
+			local->scan.chan_idx = 0;
+			local->scan.mode_idx++;
+			if (local->scan.mode_idx >= local->hw.num_modes)
+				local->scan.mode_idx = 0;
+			*mode = &local->hw.modes[local->scan.mode_idx];
+		}
+		*chan = &(*mode)->channels[local->scan.chan_idx];
+		if ((*chan)->flag & IEEE80211_CHAN_W_SCAN)
+			break;
+	} while (local->scan.chan_idx != prev ||
+		 local->scan.mode_idx != prev_m);
+}
+
+
+static void ieee80211_scan_start(struct ieee80211_local *local,
+				 struct ieee80211_scan_conf *conf)
+{
+	int old_mode_idx = local->scan.mode_idx;
+	int old_chan_idx = local->scan.chan_idx;
+	struct ieee80211_hw_modes *mode = NULL;
+	struct ieee80211_channel *chan = NULL;
+	int ret;
+
+	if (!local->ops->passive_scan) {
+		printk(KERN_DEBUG "%s: Scan handler called, yet the hardware "
+		       "does not support passive scanning. Disabled.\n",
+		       local->mdev->name);
+		return;
+	}
+
+	if ((local->scan.tries < MAX_SCAN_WAIT &&
+	     local->scan.txrx_count > SCAN_TXRX_THRESHOLD)) {
+		local->scan.tries++;
+		/* Count TX/RX packets during one second interval and allow
+		 * scan to start only if the number of packets is below the
+		 * threshold. */
+		local->scan.txrx_count = 0;
+		local->scan.timer.expires = jiffies + HZ;
+		add_timer(&local->scan.timer);
+		return;
+	}
+
+	if (!local->scan.skb) {
+		printk(KERN_DEBUG "%s: Scan start called even though scan.skb "
+		       "is not set\n", local->mdev->name);
+	}
+
+	if (local->scan.our_mode_only) {
+		if (local->scan.channel > 0) {
+			get_channel_params(local, local->scan.channel, &mode,
+					   &chan);
+		} else
+			next_chan_same_mode(local, &mode, &chan);
+	}
+	else
+		next_chan_all_modes(local, &mode, &chan);
+
+	conf->scan_channel = chan->chan;
+	conf->scan_freq = chan->freq;
+	conf->scan_channel_val = chan->val;
+	conf->scan_phymode = mode->mode;
+	conf->scan_power_level = chan->power_level;
+	conf->scan_antenna_max = chan->antenna_max;
+	conf->scan_time = 2 * local->hw.channel_change_time +
+		local->scan.time; /* 10ms scan time+hardware changes */
+	conf->skb = local->scan.skb ?
+		skb_clone(local->scan.skb, GFP_ATOMIC) : NULL;
+	conf->tx_control = &local->scan.tx_control;
+#if 0
+	printk(KERN_DEBUG "%s: Doing scan on mode: %d freq: %d chan: %d "
+	       "for %d ms\n",
+	       local->mdev->name, conf->scan_phymode, conf->scan_freq,
+	       conf->scan_channel, conf->scan_time);
+#endif
+	local->scan.rx_packets = 0;
+	local->scan.rx_beacon = 0;
+	local->scan.freq = chan->freq;
+	local->scan.in_scan = 1;
+
+	ieee80211_netif_oper(local_to_hw(local), NETIF_STOP);
+
+	ret = local->ops->passive_scan(local_to_hw(local),
+				      IEEE80211_SCAN_START, conf);
+
+	if (ret == 0) {
+		long usec = local->hw.channel_change_time +
+			local->scan.time;
+		usec += 1000000L / HZ - 1;
+		usec /= 1000000L / HZ;
+		local->scan.timer.expires = jiffies + usec;
+	} else {
+		local->scan.in_scan = 0;
+		if (conf->skb)
+			dev_kfree_skb(conf->skb);
+		ieee80211_netif_oper(local_to_hw(local), NETIF_WAKE);
+		if (ret == -EAGAIN) {
+			local->scan.timer.expires = jiffies +
+				(local->scan.interval * HZ / 100);
+			local->scan.mode_idx = old_mode_idx;
+			local->scan.chan_idx = old_chan_idx;
+		} else {
+			printk(KERN_DEBUG "%s: Got unknown error from "
+			       "passive_scan %d\n", local->mdev->name, ret);
+			local->scan.timer.expires = jiffies +
+				(local->scan.interval * HZ);
+		}
+		local->scan.in_scan = 0;
+	}
+
+	add_timer(&local->scan.timer);
+}
+
+
+static void ieee80211_scan_stop(struct ieee80211_local *local,
+				struct ieee80211_scan_conf *conf)
+{
+	struct ieee80211_hw_modes *mode;
+	struct ieee80211_channel *chan;
+	int wait;
+
+	if (!local->ops->passive_scan)
+		return;
+
+	if (local->scan.mode_idx >= local->hw.num_modes) {
+		local->scan.mode_idx = 0;
+		local->scan.chan_idx = 0;
+	}
+
+	mode = &local->hw.modes[local->scan.mode_idx];
+
+	if (local->scan.chan_idx >= mode->num_channels) {
+		local->scan.chan_idx = 0;
+	}
+
+	chan = &mode->channels[local->scan.chan_idx];
+
+	local->ops->passive_scan(local_to_hw(local), IEEE80211_SCAN_END,
+				conf);
+
+#ifdef CONFIG_D80211_VERBOSE_DEBUG
+	printk(KERN_DEBUG "%s: Did scan on mode: %d freq: %d chan: %d "
+	       "GOT: %d Beacon: %d (%d)\n",
+	       local->mdev->name,
+	       mode->mode, chan->freq, chan->chan,
+	       local->scan.rx_packets, local->scan.rx_beacon,
+	       local->scan.tries);
+#endif /* CONFIG_D80211_VERBOSE_DEBUG */
+	local->scan.num_scans++;
+
+	local->scan.in_scan = 0;
+	ieee80211_netif_oper(local_to_hw(local), NETIF_WAKE);
+
+	local->scan.tries = 0;
+	/* Use random interval of scan.interval .. 2 * scan.interval */
+	wait = (local->scan.interval * HZ * ((net_random() & 127) + 128)) /
+		128;
+	local->scan.timer.expires = jiffies + wait;
+
+	add_timer(&local->scan.timer);
+}
+
+
+static void ieee80211_scan_handler(unsigned long ullocal)
+{
+	struct ieee80211_local *local = (struct ieee80211_local *) ullocal;
+	struct ieee80211_scan_conf conf;
+
+	if (local->scan.interval == 0 && !local->scan.in_scan) {
+		/* Passive scanning is disabled - keep the timer always
+		 * running to make code cleaner. */
+		local->scan.timer.expires = jiffies + 10 * HZ;
+		add_timer(&local->scan.timer);
+		return;
+	}
+
+	memset(&conf, 0, sizeof(struct ieee80211_scan_conf));
+	conf.running_freq = local->hw.conf.freq;
+	conf.running_channel = local->hw.conf.channel;
+        conf.running_phymode = local->hw.conf.phymode;
+	conf.running_channel_val = local->hw.conf.channel_val;
+        conf.running_power_level = local->hw.conf.power_level;
+        conf.running_antenna_max = local->hw.conf.antenna_max;
+
+	if (local->scan.in_scan == 0)
+		ieee80211_scan_start(local, &conf);
+	else
+		ieee80211_scan_stop(local, &conf);
+}
+
+
+void ieee80211_init_scan(struct ieee80211_local *local)
+{
+	struct ieee80211_hdr hdr;
+	u16 fc;
+	int len = 10;
+	struct rate_control_extra extra;
+
+	/* Only initialize passive scanning if the hardware supports it */
+	if (!local->ops->passive_scan) {
+		local->scan.skb = NULL;
+		memset(&local->scan.tx_control, 0,
+		       sizeof(local->scan.tx_control));
+		printk(KERN_DEBUG "%s: Does not support passive scan, "
+		       "disabled\n", local->mdev->name);
+		return;
+	}
+
+	local->scan.interval = 0;
+	local->scan.our_mode_only = 1;
+	local->scan.time = 10000;
+	local->scan.timer.function = ieee80211_scan_handler;
+	local->scan.timer.data = (unsigned long) local;
+	local->scan.timer.expires = jiffies + local->scan.interval * HZ;
+	add_timer(&local->scan.timer);
+
+	/* Create a CTS from for broadcasting before
+	 * the low level changes channels */
+	local->scan.skb = alloc_skb(len, GFP_KERNEL);
+	if (!local->scan.skb) {
+		printk(KERN_WARNING "%s: Failed to allocate CTS packet for "
+		       "passive scan\n", local->mdev->name);
+		return;
+	}
+
+	fc = IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS;
+	hdr.frame_control = cpu_to_le16(fc);
+	hdr.duration_id =
+		cpu_to_le16(2 * local->hw.channel_change_time +
+			    local->scan.time);
+	memcpy(hdr.addr1, local->mdev->dev_addr, ETH_ALEN); /* DA */
+	hdr.seq_ctrl = 0;
+
+	memcpy(skb_put(local->scan.skb, len), &hdr, len);
+
+	memset(&local->scan.tx_control, 0, sizeof(local->scan.tx_control));
+	local->scan.tx_control.key_idx = HW_KEY_IDX_INVALID;
+	local->scan.tx_control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+	memset(&extra, 0, sizeof(extra));
+	extra.endidx = local->num_curr_rates;
+	local->scan.tx_control.tx_rate =
+		rate_control_get_rate(local, local->mdev,
+				      local->scan.skb, &extra)->val;
+	local->scan.tx_control.flags |= IEEE80211_TXCTL_NO_ACK;
+}
+
+
+void ieee80211_stop_scan(struct ieee80211_local *local)
+{
+	if (local->ops->passive_scan) {
+		del_timer_sync(&local->scan.timer);
+		dev_kfree_skb(local->scan.skb);
+		local->scan.skb = NULL;
+	}
+}