+++ /dev/null
-/*
- * 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/config.h>
-#include <linux/version.h>
-#include <linux/module.h>
-#include <linux/netdevice.h>
-#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/skbuff.h>
-
-#include <net/ieee80211.h>
-#include "ieee80211_i.h"
-#include "rate_control.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->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->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 net_device *dev,
- struct ieee80211_scan_conf *conf)
-{
- struct ieee80211_local *local = dev->priv;
- 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->hw->passive_scan == 0) {
- printk(KERN_DEBUG "%s: Scan handler called, yet the hardware "
- "does not support passive scanning. Disabled.\n",
- dev->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 == NULL) {
- printk(KERN_DEBUG "%s: Scan start called even though scan.skb "
- "is not set\n", dev->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",
- dev->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(dev, NETIF_STOP);
-
- ret = local->hw->passive_scan(dev, 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(dev, 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", dev->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 net_device *dev,
- struct ieee80211_scan_conf *conf)
-{
- struct ieee80211_local *local = dev->priv;
- struct ieee80211_hw_modes *mode;
- struct ieee80211_channel *chan;
- int wait;
-
- if (local->hw->passive_scan == NULL)
- 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->hw->passive_scan(dev, IEEE80211_SCAN_END, conf);
-
-#ifdef CONFIG_IEEE80211_VERBOSE_DEBUG
- printk(KERN_DEBUG "%s: Did scan on mode: %d freq: %d chan: %d "
- "GOT: %d Beacon: %d (%d)\n",
- dev->name,
- mode->mode, chan->freq, chan->chan,
- local->scan.rx_packets, local->scan.rx_beacon,
- local->scan.tries);
-#endif /* CONFIG_IEEE80211_VERBOSE_DEBUG */
- local->scan.num_scans++;
-
- local->scan.in_scan = 0;
- ieee80211_netif_oper(dev, 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 uldev)
-{
- struct net_device *dev = (struct net_device *) uldev;
- struct ieee80211_local *local = dev->priv;
- 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->conf.freq;
- conf.running_channel = local->conf.channel;
- conf.running_phymode = local->conf.phymode;
- conf.running_channel_val = local->conf.channel_val;
- conf.running_power_level = local->conf.power_level;
- conf.running_antenna_max = local->conf.antenna_max;
-
- if (local->scan.in_scan == 0)
- ieee80211_scan_start(dev, &conf);
- else
- ieee80211_scan_stop(dev, &conf);
-}
-
-
-void ieee80211_init_scan(struct net_device *dev)
-{
- struct ieee80211_local *local = dev->priv;
- 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->hw->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", dev->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) dev;
- 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 == NULL) {
- printk(KERN_WARNING "%s: Failed to allocate CTS packet for "
- "passive scan\n", dev->name);
- return;
- }
-
- fc = (WLAN_FC_TYPE_CTRL << 2) | (WLAN_FC_STYPE_CTS << 4);
- 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, dev->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.do_not_encrypt = 1;
- memset(&extra, 0, sizeof(extra));
- extra.endidx = local->num_curr_rates;
- local->scan.tx_control.tx_rate =
- rate_control_get_rate(dev, local->scan.skb, &extra)->val;
- local->scan.tx_control.no_ack = 1;
-}
-
-
-void ieee80211_stop_scan(struct net_device *dev)
-{
- struct ieee80211_local *local = dev->priv;
-
- if (local->hw->passive_scan != 0) {
- del_timer_sync(&local->scan.timer);
- dev_kfree_skb(local->scan.skb);
- local->scan.skb = NULL;
- }
-}
projects / openwrt / svn-archive / archive.git / blobdiff