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linux/drivers/net/wireless/iwlwifi/iwl-scan.c
Reinette Chatre bbcbb9ef97 iwlwifi: fix scan race 
There is a problem if an "internal short scan" is in progress when a
mac80211 requested scan arrives. If this new scan request arrives within
the "next_scan_jiffies" period then driver will immediately return success
and complete the scan. The problem here is that the scan has not been
fully initialized at this time (is_internal_short_scan is still set to true
because of the currently running scan), which results in the scan
completion never to be sent to mac80211. At this time also, evan though the
internal short scan is still running the state (is_internal_short_scan)
will be set to false, so when the internal scan does complete then mac80211
will receive a scan completion.

Fix this by checking right away if a scan is in progress when a scan
request arrives from mac80211.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
2010-02-11 10:26:40 -08:00

988 lines
28 KiB
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/******************************************************************************
*
* GPL LICENSE SUMMARY
*
* Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
* USA
*
* The full GNU General Public License is included in this distribution
* in the file called LICENSE.GPL.
*
* Contact Information:
* Intel Linux Wireless <ilw@linux.intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*****************************************************************************/
#include <linux/types.h>
#include <linux/etherdevice.h>
#include <net/mac80211.h>
#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-sta.h"
#include "iwl-io.h"
#include "iwl-helpers.h"
/* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
* sending probe req. This should be set long enough to hear probe responses
* from more than one AP. */
#define IWL_ACTIVE_DWELL_TIME_24 (30) /* all times in msec */
#define IWL_ACTIVE_DWELL_TIME_52 (20)
#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
/* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
* Must be set longer than active dwell time.
* For the most reliable scan, set > AP beacon interval (typically 100msec). */
#define IWL_PASSIVE_DWELL_TIME_24 (20) /* all times in msec */
#define IWL_PASSIVE_DWELL_TIME_52 (10)
#define IWL_PASSIVE_DWELL_BASE (100)
#define IWL_CHANNEL_TUNE_TIME 5
/**
* iwl_scan_cancel - Cancel any currently executing HW scan
*
* NOTE: priv->mutex is not required before calling this function
*/
int iwl_scan_cancel(struct iwl_priv *priv)
{
if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
clear_bit(STATUS_SCANNING, &priv->status);
return 0;
}
if (test_bit(STATUS_SCANNING, &priv->status)) {
if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
set_bit(STATUS_SCAN_ABORTING, &priv->status);
queue_work(priv->workqueue, &priv->abort_scan);
} else
IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
return test_bit(STATUS_SCANNING, &priv->status);
}
return 0;
}
EXPORT_SYMBOL(iwl_scan_cancel);
/**
* iwl_scan_cancel_timeout - Cancel any currently executing HW scan
* @ms: amount of time to wait (in milliseconds) for scan to abort
*
* NOTE: priv->mutex must be held before calling this function
*/
int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
{
unsigned long now = jiffies;
int ret;
ret = iwl_scan_cancel(priv);
if (ret && ms) {
mutex_unlock(&priv->mutex);
while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
test_bit(STATUS_SCANNING, &priv->status))
msleep(1);
mutex_lock(&priv->mutex);
return test_bit(STATUS_SCANNING, &priv->status);
}
return ret;
}
EXPORT_SYMBOL(iwl_scan_cancel_timeout);
static int iwl_send_scan_abort(struct iwl_priv *priv)
{
int ret = 0;
struct iwl_rx_packet *pkt;
struct iwl_host_cmd cmd = {
.id = REPLY_SCAN_ABORT_CMD,
.flags = CMD_WANT_SKB,
};
/* If there isn't a scan actively going on in the hardware
* then we are in between scan bands and not actually
* actively scanning, so don't send the abort command */
if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
clear_bit(STATUS_SCAN_ABORTING, &priv->status);
return 0;
}
ret = iwl_send_cmd_sync(priv, &cmd);
if (ret) {
clear_bit(STATUS_SCAN_ABORTING, &priv->status);
return ret;
}
pkt = (struct iwl_rx_packet *)cmd.reply_page;
if (pkt->u.status != CAN_ABORT_STATUS) {
/* The scan abort will return 1 for success or
* 2 for "failure". A failure condition can be
* due to simply not being in an active scan which
* can occur if we send the scan abort before we
* the microcode has notified us that a scan is
* completed. */
IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
clear_bit(STATUS_SCAN_ABORTING, &priv->status);
clear_bit(STATUS_SCAN_HW, &priv->status);
}
iwl_free_pages(priv, cmd.reply_page);
return ret;
}
/* Service response to REPLY_SCAN_CMD (0x80) */
static void iwl_rx_reply_scan(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_DEBUG
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_scanreq_notification *notif =
(struct iwl_scanreq_notification *)pkt->u.raw;
IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
#endif
}
/* Service SCAN_START_NOTIFICATION (0x82) */
static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_scanstart_notification *notif =
(struct iwl_scanstart_notification *)pkt->u.raw;
priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
IWL_DEBUG_SCAN(priv, "Scan start: "
"%d [802.11%s] "
"(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
notif->channel,
notif->band ? "bg" : "a",
le32_to_cpu(notif->tsf_high),
le32_to_cpu(notif->tsf_low),
notif->status, notif->beacon_timer);
}
/* Service SCAN_RESULTS_NOTIFICATION (0x83) */
static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_DEBUG
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_scanresults_notification *notif =
(struct iwl_scanresults_notification *)pkt->u.raw;
IWL_DEBUG_SCAN(priv, "Scan ch.res: "
"%d [802.11%s] "
"(TSF: 0x%08X:%08X) - %d "
"elapsed=%lu usec\n",
notif->channel,
notif->band ? "bg" : "a",
le32_to_cpu(notif->tsf_high),
le32_to_cpu(notif->tsf_low),
le32_to_cpu(notif->statistics[0]),
le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
#endif
if (!priv->is_internal_short_scan)
priv->next_scan_jiffies = 0;
}
/* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
struct iwl_rx_mem_buffer *rxb)
{
#ifdef CONFIG_IWLWIFI_DEBUG
struct iwl_rx_packet *pkt = rxb_addr(rxb);
struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
scan_notif->scanned_channels,
scan_notif->tsf_low,
scan_notif->tsf_high, scan_notif->status);
#endif
/* The HW is no longer scanning */
clear_bit(STATUS_SCAN_HW, &priv->status);
IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
(priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
"2.4" : "5.2",
jiffies_to_msecs(elapsed_jiffies
(priv->scan_pass_start, jiffies)));
/* Remove this scanned band from the list of pending
* bands to scan, band G precedes A in order of scanning
* as seen in iwl_bg_request_scan */
if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ))
priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
/* If a request to abort was given, or the scan did not succeed
* then we reset the scan state machine and terminate,
* re-queuing another scan if one has been requested */
if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
clear_bit(STATUS_SCAN_ABORTING, &priv->status);
} else {
/* If there are more bands on this scan pass reschedule */
if (priv->scan_bands)
goto reschedule;
}
if (!priv->is_internal_short_scan)
priv->next_scan_jiffies = 0;
IWL_DEBUG_INFO(priv, "Setting scan to off\n");
clear_bit(STATUS_SCANNING, &priv->status);
IWL_DEBUG_INFO(priv, "Scan took %dms\n",
jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
queue_work(priv->workqueue, &priv->scan_completed);
return;
reschedule:
priv->scan_pass_start = jiffies;
queue_work(priv->workqueue, &priv->request_scan);
}
void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
{
/* scan handlers */
priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
iwl_rx_scan_results_notif;
priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
iwl_rx_scan_complete_notif;
}
EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
enum ieee80211_band band,
u8 n_probes)
{
if (band == IEEE80211_BAND_5GHZ)
return IWL_ACTIVE_DWELL_TIME_52 +
IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
else
return IWL_ACTIVE_DWELL_TIME_24 +
IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
}
EXPORT_SYMBOL(iwl_get_active_dwell_time);
u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
enum ieee80211_band band)
{
u16 passive = (band == IEEE80211_BAND_2GHZ) ?
IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
if (iwl_is_associated(priv)) {
/* If we're associated, we clamp the maximum passive
* dwell time to be 98% of the beacon interval (minus
* 2 * channel tune time) */
passive = priv->beacon_int;
if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
passive = IWL_PASSIVE_DWELL_BASE;
passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
}
return passive;
}
EXPORT_SYMBOL(iwl_get_passive_dwell_time);
static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
enum ieee80211_band band,
struct iwl_scan_channel *scan_ch)
{
const struct ieee80211_supported_band *sband;
const struct iwl_channel_info *ch_info;
u16 passive_dwell = 0;
u16 active_dwell = 0;
int i, added = 0;
u16 channel = 0;
sband = iwl_get_hw_mode(priv, band);
if (!sband) {
IWL_ERR(priv, "invalid band\n");
return added;
}
active_dwell = iwl_get_active_dwell_time(priv, band, 0);
passive_dwell = iwl_get_passive_dwell_time(priv, band);
if (passive_dwell <= active_dwell)
passive_dwell = active_dwell + 1;
/* only scan single channel, good enough to reset the RF */
/* pick the first valid not in-use channel */
if (band == IEEE80211_BAND_5GHZ) {
for (i = 14; i < priv->channel_count; i++) {
if (priv->channel_info[i].channel !=
le16_to_cpu(priv->staging_rxon.channel)) {
channel = priv->channel_info[i].channel;
ch_info = iwl_get_channel_info(priv,
band, channel);
if (is_channel_valid(ch_info))
break;
}
}
} else {
for (i = 0; i < 14; i++) {
if (priv->channel_info[i].channel !=
le16_to_cpu(priv->staging_rxon.channel)) {
channel =
priv->channel_info[i].channel;
ch_info = iwl_get_channel_info(priv,
band, channel);
if (is_channel_valid(ch_info))
break;
}
}
}
if (channel) {
scan_ch->channel = cpu_to_le16(channel);
scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
scan_ch->active_dwell = cpu_to_le16(active_dwell);
scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
/* Set txpower levels to defaults */
scan_ch->dsp_atten = 110;
if (band == IEEE80211_BAND_5GHZ)
scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
else
scan_ch->tx_gain = ((1 << 5) | (5 << 3));
added++;
} else
IWL_ERR(priv, "no valid channel found\n");
return added;
}
static int iwl_get_channels_for_scan(struct iwl_priv *priv,
enum ieee80211_band band,
u8 is_active, u8 n_probes,
struct iwl_scan_channel *scan_ch)
{
struct ieee80211_channel *chan;
const struct ieee80211_supported_band *sband;
const struct iwl_channel_info *ch_info;
u16 passive_dwell = 0;
u16 active_dwell = 0;
int added, i;
u16 channel;
sband = iwl_get_hw_mode(priv, band);
if (!sband)
return 0;
active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
passive_dwell = iwl_get_passive_dwell_time(priv, band);
if (passive_dwell <= active_dwell)
passive_dwell = active_dwell + 1;
for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
chan = priv->scan_request->channels[i];
if (chan->band != band)
continue;
channel = ieee80211_frequency_to_channel(chan->center_freq);
scan_ch->channel = cpu_to_le16(channel);
ch_info = iwl_get_channel_info(priv, band, channel);
if (!is_channel_valid(ch_info)) {
IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
channel);
continue;
}
if (!is_active || is_channel_passive(ch_info) ||
(chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
else
scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
if (n_probes)
scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
scan_ch->active_dwell = cpu_to_le16(active_dwell);
scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
/* Set txpower levels to defaults */
scan_ch->dsp_atten = 110;
/* NOTE: if we were doing 6Mb OFDM for scans we'd use
* power level:
* scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
*/
if (band == IEEE80211_BAND_5GHZ)
scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
else
scan_ch->tx_gain = ((1 << 5) | (5 << 3));
IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
channel, le32_to_cpu(scan_ch->type),
(scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
"ACTIVE" : "PASSIVE",
(scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
active_dwell : passive_dwell);
scan_ch++;
added++;
}
IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
return added;
}
void iwl_init_scan_params(struct iwl_priv *priv)
{
u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
}
EXPORT_SYMBOL(iwl_init_scan_params);
static int iwl_scan_initiate(struct iwl_priv *priv)
{
IWL_DEBUG_INFO(priv, "Starting scan...\n");
set_bit(STATUS_SCANNING, &priv->status);
priv->is_internal_short_scan = false;
priv->scan_start = jiffies;
priv->scan_pass_start = priv->scan_start;
queue_work(priv->workqueue, &priv->request_scan);
return 0;
}
#define IWL_DELAY_NEXT_SCAN (HZ*2)
int iwl_mac_hw_scan(struct ieee80211_hw *hw,
struct cfg80211_scan_request *req)
{
unsigned long flags;
struct iwl_priv *priv = hw->priv;
int ret, i;
IWL_DEBUG_MAC80211(priv, "enter\n");
mutex_lock(&priv->mutex);
spin_lock_irqsave(&priv->lock, flags);
if (!iwl_is_ready_rf(priv)) {
ret = -EIO;
IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
goto out_unlock;
}
if (test_bit(STATUS_SCANNING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
ret = -EAGAIN;
goto out_unlock;
}
if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
ret = -EAGAIN;
goto out_unlock;
}
/* We don't schedule scan within next_scan_jiffies period.
* Avoid scanning during possible EAPOL exchange, return
* success immediately.
*/
if (priv->next_scan_jiffies &&
time_after(priv->next_scan_jiffies, jiffies)) {
IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
queue_work(priv->workqueue, &priv->scan_completed);
ret = 0;
goto out_unlock;
}
priv->scan_bands = 0;
for (i = 0; i < req->n_channels; i++)
priv->scan_bands |= BIT(req->channels[i]->band);
priv->scan_request = req;
ret = iwl_scan_initiate(priv);
IWL_DEBUG_MAC80211(priv, "leave\n");
out_unlock:
spin_unlock_irqrestore(&priv->lock, flags);
mutex_unlock(&priv->mutex);
return ret;
}
EXPORT_SYMBOL(iwl_mac_hw_scan);
/*
* internal short scan, this function should only been called while associated.
* It will reset and tune the radio to prevent possible RF related problem
*/
int iwl_internal_short_hw_scan(struct iwl_priv *priv)
{
int ret = 0;
if (!iwl_is_ready_rf(priv)) {
ret = -EIO;
IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
goto out;
}
if (test_bit(STATUS_SCANNING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
ret = -EAGAIN;
goto out;
}
if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
ret = -EAGAIN;
goto out;
}
priv->scan_bands = 0;
if (priv->band == IEEE80211_BAND_5GHZ)
priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
else
priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
set_bit(STATUS_SCANNING, &priv->status);
priv->is_internal_short_scan = true;
queue_work(priv->workqueue, &priv->request_scan);
out:
return ret;
}
EXPORT_SYMBOL(iwl_internal_short_hw_scan);
#define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
void iwl_bg_scan_check(struct work_struct *data)
{
struct iwl_priv *priv =
container_of(data, struct iwl_priv, scan_check.work);
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return;
mutex_lock(&priv->mutex);
if (test_bit(STATUS_SCANNING, &priv->status) ||
test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
"adapter (%dms)\n",
jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
iwl_send_scan_abort(priv);
}
mutex_unlock(&priv->mutex);
}
EXPORT_SYMBOL(iwl_bg_scan_check);
/**
* iwl_fill_probe_req - fill in all required fields and IE for probe request
*/
u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
const u8 *ies, int ie_len, int left)
{
int len = 0;
u8 *pos = NULL;
/* Make sure there is enough space for the probe request,
* two mandatory IEs and the data */
left -= 24;
if (left < 0)
return 0;
frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
frame->seq_ctrl = 0;
len += 24;
/* ...next IE... */
pos = &frame->u.probe_req.variable[0];
/* fill in our indirect SSID IE */
left -= 2;
if (left < 0)
return 0;
*pos++ = WLAN_EID_SSID;
if (!priv->is_internal_short_scan &&
priv->scan_request->n_ssids) {
struct cfg80211_ssid *ssid =
priv->scan_request->ssids;
/* Broadcast if ssid_len is 0 */
*pos++ = ssid->ssid_len;
memcpy(pos, ssid->ssid, ssid->ssid_len);
pos += ssid->ssid_len;
len += 2 + ssid->ssid_len;
} else {
*pos++ = 0;
len += 2;
}
if (WARN_ON(left < ie_len))
return len;
if (ies)
memcpy(pos, ies, ie_len);
len += ie_len;
left -= ie_len;
return (u16)len;
}
EXPORT_SYMBOL(iwl_fill_probe_req);
static void iwl_bg_request_scan(struct work_struct *data)
{
struct iwl_priv *priv =
container_of(data, struct iwl_priv, request_scan);
struct iwl_host_cmd cmd = {
.id = REPLY_SCAN_CMD,
.len = sizeof(struct iwl_scan_cmd),
.flags = CMD_SIZE_HUGE,
};
struct iwl_scan_cmd *scan;
struct ieee80211_conf *conf = NULL;
int ret = 0;
u32 rate_flags = 0;
u16 cmd_len;
u16 rx_chain = 0;
enum ieee80211_band band;
u8 n_probes = 0;
u8 rx_ant = priv->hw_params.valid_rx_ant;
u8 rate;
bool is_active = false;
int chan_mod;
u8 active_chains;
conf = ieee80211_get_hw_conf(priv->hw);
mutex_lock(&priv->mutex);
cancel_delayed_work(&priv->scan_check);
if (!iwl_is_ready(priv)) {
IWL_WARN(priv, "request scan called when driver not ready.\n");
goto done;
}
/* Make sure the scan wasn't canceled before this queued work
* was given the chance to run... */
if (!test_bit(STATUS_SCANNING, &priv->status))
goto done;
/* This should never be called or scheduled if there is currently
* a scan active in the hardware. */
if (test_bit(STATUS_SCAN_HW, &priv->status)) {
IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
"Ignoring second request.\n");
ret = -EIO;
goto done;
}
if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
goto done;
}
if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
IWL_DEBUG_HC(priv, "Scan request while abort pending. Queuing.\n");
goto done;
}
if (iwl_is_rfkill(priv)) {
IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
goto done;
}
if (!test_bit(STATUS_READY, &priv->status)) {
IWL_DEBUG_HC(priv, "Scan request while uninitialized. Queuing.\n");
goto done;
}
if (!priv->scan_bands) {
IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
goto done;
}
if (!priv->scan) {
priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
IWL_MAX_SCAN_SIZE, GFP_KERNEL);
if (!priv->scan) {
ret = -ENOMEM;
goto done;
}
}
scan = priv->scan;
memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
if (iwl_is_associated(priv)) {
u16 interval = 0;
u32 extra;
u32 suspend_time = 100;
u32 scan_suspend_time = 100;
unsigned long flags;
IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
spin_lock_irqsave(&priv->lock, flags);
interval = priv->beacon_int;
spin_unlock_irqrestore(&priv->lock, flags);
scan->suspend_time = 0;
scan->max_out_time = cpu_to_le32(200 * 1024);
if (!interval)
interval = suspend_time;
extra = (suspend_time / interval) << 22;
scan_suspend_time = (extra |
((suspend_time % interval) * 1024));
scan->suspend_time = cpu_to_le32(scan_suspend_time);
IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
scan_suspend_time, interval);
}
if (priv->is_internal_short_scan) {
IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
} else if (priv->scan_request->n_ssids) {
IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
/*
* The first SSID to scan is stuffed into the probe request
* template and the remaining ones are handled through the
* direct_scan array.
*/
if (priv->scan_request->n_ssids > 1) {
int i, p = 0;
for (i = 1; i < priv->scan_request->n_ssids; i++) {
if (!priv->scan_request->ssids[i].ssid_len)
continue;
scan->direct_scan[p].id = WLAN_EID_SSID;
scan->direct_scan[p].len =
priv->scan_request->ssids[i].ssid_len;
memcpy(scan->direct_scan[p].ssid,
priv->scan_request->ssids[i].ssid,
priv->scan_request->ssids[i].ssid_len);
n_probes++;
p++;
}
}
is_active = true;
} else
IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
band = IEEE80211_BAND_2GHZ;
scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
>> RXON_FLG_CHANNEL_MODE_POS;
if (chan_mod == CHANNEL_MODE_PURE_40) {
rate = IWL_RATE_6M_PLCP;
} else {
rate = IWL_RATE_1M_PLCP;
rate_flags = RATE_MCS_CCK_MSK;
}
scan->good_CRC_th = 0;
} else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
band = IEEE80211_BAND_5GHZ;
rate = IWL_RATE_6M_PLCP;
/*
* If active scaning is requested but a certain channel
* is marked passive, we can do active scanning if we
* detect transmissions.
*/
scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
/* Force use of chains B and C (0x6) for scan Rx for 4965
* Avoid A (0x1) because of its off-channel reception on A-band.
*/
if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
rx_ant = ANT_BC;
} else {
IWL_WARN(priv, "Invalid scan band count\n");
goto done;
}
priv->scan_tx_ant[band] =
iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
/* In power save mode use one chain, otherwise use all chains */
if (test_bit(STATUS_POWER_PMI, &priv->status)) {
/* rx_ant has been set to all valid chains previously */
active_chains = rx_ant &
((u8)(priv->chain_noise_data.active_chains));
if (!active_chains)
active_chains = rx_ant;
IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
priv->chain_noise_data.active_chains);
rx_ant = first_antenna(active_chains);
}
/* MIMO is not used here, but value is required */
rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
scan->rx_chain = cpu_to_le16(rx_chain);
if (!priv->is_internal_short_scan) {
cmd_len = iwl_fill_probe_req(priv,
(struct ieee80211_mgmt *)scan->data,
priv->scan_request->ie,
priv->scan_request->ie_len,
IWL_MAX_SCAN_SIZE - sizeof(*scan));
} else {
cmd_len = iwl_fill_probe_req(priv,
(struct ieee80211_mgmt *)scan->data,
NULL, 0,
IWL_MAX_SCAN_SIZE - sizeof(*scan));
}
scan->tx_cmd.len = cpu_to_le16(cmd_len);
if (iwl_is_monitor_mode(priv))
scan->filter_flags = RXON_FILTER_PROMISC_MSK;
scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
RXON_FILTER_BCON_AWARE_MSK);
if (priv->is_internal_short_scan) {
scan->channel_count =
iwl_get_single_channel_for_scan(priv, band,
(void *)&scan->data[le16_to_cpu(
scan->tx_cmd.len)]);
} else {
scan->channel_count =
iwl_get_channels_for_scan(priv, band,
is_active, n_probes,
(void *)&scan->data[le16_to_cpu(
scan->tx_cmd.len)]);
}
if (scan->channel_count == 0) {
IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
goto done;
}
cmd.len += le16_to_cpu(scan->tx_cmd.len) +
scan->channel_count * sizeof(struct iwl_scan_channel);
cmd.data = scan;
scan->len = cpu_to_le16(cmd.len);
set_bit(STATUS_SCAN_HW, &priv->status);
ret = iwl_send_cmd_sync(priv, &cmd);
if (ret)
goto done;
queue_delayed_work(priv->workqueue, &priv->scan_check,
IWL_SCAN_CHECK_WATCHDOG);
mutex_unlock(&priv->mutex);
return;
done:
/* Cannot perform scan. Make sure we clear scanning
* bits from status so next scan request can be performed.
* If we don't clear scanning status bit here all next scan
* will fail
*/
clear_bit(STATUS_SCAN_HW, &priv->status);
clear_bit(STATUS_SCANNING, &priv->status);
/* inform mac80211 scan aborted */
queue_work(priv->workqueue, &priv->scan_completed);
mutex_unlock(&priv->mutex);
}
void iwl_bg_abort_scan(struct work_struct *work)
{
struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
if (!test_bit(STATUS_READY, &priv->status) ||
!test_bit(STATUS_GEO_CONFIGURED, &priv->status))
return;
mutex_lock(&priv->mutex);
set_bit(STATUS_SCAN_ABORTING, &priv->status);
iwl_send_scan_abort(priv);
mutex_unlock(&priv->mutex);
}
EXPORT_SYMBOL(iwl_bg_abort_scan);
void iwl_bg_scan_completed(struct work_struct *work)
{
struct iwl_priv *priv =
container_of(work, struct iwl_priv, scan_completed);
IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
cancel_delayed_work(&priv->scan_check);
if (!priv->is_internal_short_scan)
ieee80211_scan_completed(priv->hw, false);
else {
priv->is_internal_short_scan = false;
IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
}
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return;
/* Since setting the TXPOWER may have been deferred while
* performing the scan, fire one off */
mutex_lock(&priv->mutex);
iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
mutex_unlock(&priv->mutex);
}
EXPORT_SYMBOL(iwl_bg_scan_completed);
void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
{
INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
}
EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
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