linux/net/mac80211/scan.c

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/*
* Scanning implementation
*
* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
* Copyright 2004, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
*
* 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/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/pm_qos.h>
#include <net/sch_generic.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "mesh.h"
#define IEEE80211_PROBE_DELAY (HZ / 33)
#define IEEE80211_CHANNEL_TIME (HZ / 33)
mac80211: improve latency and throughput while software scanning Patch vastly improve latency while scanning. Slight throughput improvements were observed as well. Is intended for improve performance of voice and video applications, when scan is periodically requested by user space (i.e. default NetworkManager behaviour). Patch remove latency requirement based on PM_QOS_NETWORK_LATENCY, this value is 2000 seconds by default (i.e. approximately 0.5 hour !?!). Also remove listen interval requirement, which based on beaconing and depending on BSS parameters. It can make we stay off-channel for a second or more. Instead try to offer the best latency that we could, i.e. be off-channel no longer than PASSIVE channel scan time: 125 ms. That mean we will scan two ACTIVE channels and go back to on-channel, and one PASSIVE channel, and go back to on-channel. Patch also decrease PASSIVE channel scan time to about 110 ms. As drawback patch increase overall scan time. On my tests, when scanning both 2GHz and 5GHz bands, scanning time increase from 5 seconds up to 10 seconds. Since that increase happen only when we are associated, I think it can be acceptable. If eventually better scan time is needed for situations when we lose signal and quickly need to decide to which AP roam, additional scan flag or parameter can be introduced. I tested patch by doing: while true; do iw dev wlan0 scan; sleep 3; done > /dev/null and ping -i0.2 -c 1000 HOST on remote and local machine, results are as below: * Ping from local periodically scanning machine to AP: Unpatched: rtt min/avg/max/mdev = 0.928/24.946/182.135/36.873 ms Patched: rtt min/avg/max/mdev = 0.928/19.678/150.845/33.130 ms * Ping from remote machine to periodically scanning machine: Unpatched: rtt min/avg/max/mdev = 1.637/120.683/709.139/164.337 ms Patched: rtt min/avg/max/mdev = 1.807/26.893/201.435/40.284 ms Throughput measured by scp show following results. * Upload to periodically scanning machine: Unpatched: 3.9MB/s 03:15 Patched: 4.3MB/s 02:58 * Download from periodically scanning machine: Unpatched: 5.5MB/s 02:17 Patched: 6.2MB/s 02:02 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-23 11:32:45 +00:00
#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
void ieee80211_rx_bss_put(struct ieee80211_local *local,
struct ieee80211_bss *bss)
{
if (!bss)
return;
cfg80211_put_bss(local->hw.wiphy,
container_of((void *)bss, struct cfg80211_bss, priv));
}
static bool is_uapsd_supported(struct ieee802_11_elems *elems)
{
u8 qos_info;
if (elems->wmm_info && elems->wmm_info_len == 7
&& elems->wmm_info[5] == 1)
qos_info = elems->wmm_info[6];
else if (elems->wmm_param && elems->wmm_param_len == 24
&& elems->wmm_param[5] == 1)
qos_info = elems->wmm_param[6];
else
/* no valid wmm information or parameter element found */
return false;
return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
}
struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local *local,
struct ieee80211_rx_status *rx_status,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee802_11_elems *elems,
struct ieee80211_channel *channel)
{
bool beacon = ieee80211_is_beacon(mgmt->frame_control);
struct cfg80211_bss *cbss;
struct ieee80211_bss *bss;
int clen, srlen;
enum nl80211_bss_scan_width scan_width;
s32 signal = 0;
if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
signal = rx_status->signal * 100;
else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
signal = (rx_status->signal * 100) / local->hw.max_signal;
scan_width = NL80211_BSS_CHAN_WIDTH_20;
if (rx_status->flag & RX_FLAG_5MHZ)
scan_width = NL80211_BSS_CHAN_WIDTH_5;
if (rx_status->flag & RX_FLAG_10MHZ)
scan_width = NL80211_BSS_CHAN_WIDTH_10;
cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel,
scan_width, mgmt, len, signal,
GFP_ATOMIC);
if (!cbss)
return NULL;
bss = (void *)cbss->priv;
if (beacon)
bss->device_ts_beacon = rx_status->device_timestamp;
else
bss->device_ts_presp = rx_status->device_timestamp;
mac80211: Filter duplicate IE ids mac80211 is lenient with respect to reception of corrupted beacons. Even if the frame is corrupted as a whole, the available IE elements are still passed back and accepted, sometimes replacing legitimate data. It is unknown to what extent this "feature" is made use of, but it is clear that in some cases, this is detrimental. One such case is reported in http://crosbug.com/26832 where an AP corrupts its beacons but not its probe responses. One approach would be to completely reject frames with invaid data (for example, if the last tag extends beyond the end of the enclosing PDU). The enclosed approach is much more conservative: we simply prevent later IEs from overwriting the state from previous ones. This approach hopes that there might be some salient data in the IE stream before the corruption, and seeks to at least prevent that data from being overwritten. This approach will fix the case above. Further, we flag element structures that contain data we think might be corrupted, so that as we fill the mac80211 BSS structure, we try not to replace data from an un-corrupted probe response with that of a corrupted beacon, for example. Short of any statistics gathering in the various forms of AP breakage, it's not possible to ascertain the side effects of more stringent discarding of data. Signed-off-by: Paul Stewart <pstew@chromium.org> Cc: Sam Leffler <sleffler@chromium.org> Cc: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-24 01:59:53 +00:00
if (elems->parse_error) {
if (beacon)
bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
else
bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
} else {
if (beacon)
bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
else
bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
}
/* save the ERP value so that it is available at association time */
if (elems->erp_info && (!elems->parse_error ||
!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
bss->erp_value = elems->erp_info[0];
bss->has_erp_value = true;
mac80211: Filter duplicate IE ids mac80211 is lenient with respect to reception of corrupted beacons. Even if the frame is corrupted as a whole, the available IE elements are still passed back and accepted, sometimes replacing legitimate data. It is unknown to what extent this "feature" is made use of, but it is clear that in some cases, this is detrimental. One such case is reported in http://crosbug.com/26832 where an AP corrupts its beacons but not its probe responses. One approach would be to completely reject frames with invaid data (for example, if the last tag extends beyond the end of the enclosing PDU). The enclosed approach is much more conservative: we simply prevent later IEs from overwriting the state from previous ones. This approach hopes that there might be some salient data in the IE stream before the corruption, and seeks to at least prevent that data from being overwritten. This approach will fix the case above. Further, we flag element structures that contain data we think might be corrupted, so that as we fill the mac80211 BSS structure, we try not to replace data from an un-corrupted probe response with that of a corrupted beacon, for example. Short of any statistics gathering in the various forms of AP breakage, it's not possible to ascertain the side effects of more stringent discarding of data. Signed-off-by: Paul Stewart <pstew@chromium.org> Cc: Sam Leffler <sleffler@chromium.org> Cc: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-24 01:59:53 +00:00
if (!elems->parse_error)
bss->valid_data |= IEEE80211_BSS_VALID_ERP;
}
/* replace old supported rates if we get new values */
mac80211: Filter duplicate IE ids mac80211 is lenient with respect to reception of corrupted beacons. Even if the frame is corrupted as a whole, the available IE elements are still passed back and accepted, sometimes replacing legitimate data. It is unknown to what extent this "feature" is made use of, but it is clear that in some cases, this is detrimental. One such case is reported in http://crosbug.com/26832 where an AP corrupts its beacons but not its probe responses. One approach would be to completely reject frames with invaid data (for example, if the last tag extends beyond the end of the enclosing PDU). The enclosed approach is much more conservative: we simply prevent later IEs from overwriting the state from previous ones. This approach hopes that there might be some salient data in the IE stream before the corruption, and seeks to at least prevent that data from being overwritten. This approach will fix the case above. Further, we flag element structures that contain data we think might be corrupted, so that as we fill the mac80211 BSS structure, we try not to replace data from an un-corrupted probe response with that of a corrupted beacon, for example. Short of any statistics gathering in the various forms of AP breakage, it's not possible to ascertain the side effects of more stringent discarding of data. Signed-off-by: Paul Stewart <pstew@chromium.org> Cc: Sam Leffler <sleffler@chromium.org> Cc: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-24 01:59:53 +00:00
if (!elems->parse_error ||
!(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
srlen = 0;
if (elems->supp_rates) {
clen = IEEE80211_MAX_SUPP_RATES;
if (clen > elems->supp_rates_len)
clen = elems->supp_rates_len;
memcpy(bss->supp_rates, elems->supp_rates, clen);
srlen += clen;
}
if (elems->ext_supp_rates) {
clen = IEEE80211_MAX_SUPP_RATES - srlen;
if (clen > elems->ext_supp_rates_len)
clen = elems->ext_supp_rates_len;
memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
clen);
srlen += clen;
}
if (srlen) {
bss->supp_rates_len = srlen;
if (!elems->parse_error)
bss->valid_data |= IEEE80211_BSS_VALID_RATES;
}
}
mac80211: Filter duplicate IE ids mac80211 is lenient with respect to reception of corrupted beacons. Even if the frame is corrupted as a whole, the available IE elements are still passed back and accepted, sometimes replacing legitimate data. It is unknown to what extent this "feature" is made use of, but it is clear that in some cases, this is detrimental. One such case is reported in http://crosbug.com/26832 where an AP corrupts its beacons but not its probe responses. One approach would be to completely reject frames with invaid data (for example, if the last tag extends beyond the end of the enclosing PDU). The enclosed approach is much more conservative: we simply prevent later IEs from overwriting the state from previous ones. This approach hopes that there might be some salient data in the IE stream before the corruption, and seeks to at least prevent that data from being overwritten. This approach will fix the case above. Further, we flag element structures that contain data we think might be corrupted, so that as we fill the mac80211 BSS structure, we try not to replace data from an un-corrupted probe response with that of a corrupted beacon, for example. Short of any statistics gathering in the various forms of AP breakage, it's not possible to ascertain the side effects of more stringent discarding of data. Signed-off-by: Paul Stewart <pstew@chromium.org> Cc: Sam Leffler <sleffler@chromium.org> Cc: Eliad Peller <eliad@wizery.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-24 01:59:53 +00:00
if (!elems->parse_error ||
!(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
bss->wmm_used = elems->wmm_param || elems->wmm_info;
bss->uapsd_supported = is_uapsd_supported(elems);
if (!elems->parse_error)
bss->valid_data |= IEEE80211_BSS_VALID_WMM;
}
if (beacon) {
struct ieee80211_supported_band *sband =
local->hw.wiphy->bands[rx_status->band];
if (!(rx_status->flag & RX_FLAG_HT) &&
!(rx_status->flag & RX_FLAG_VHT))
bss->beacon_rate =
&sband->bitrates[rx_status->rate_idx];
}
return bss;
}
void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
{
struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
struct ieee80211_sub_if_data *sdata1, *sdata2;
struct ieee80211_mgmt *mgmt = (void *)skb->data;
struct ieee80211_bss *bss;
u8 *elements;
struct ieee80211_channel *channel;
size_t baselen;
struct ieee802_11_elems elems;
if (skb->len < 24 ||
(!ieee80211_is_probe_resp(mgmt->frame_control) &&
!ieee80211_is_beacon(mgmt->frame_control)))
return;
sdata1 = rcu_dereference(local->scan_sdata);
sdata2 = rcu_dereference(local->sched_scan_sdata);
if (likely(!sdata1 && !sdata2))
return;
if (ieee80211_is_probe_resp(mgmt->frame_control)) {
/* ignore ProbeResp to foreign address */
if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
(!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
return;
elements = mgmt->u.probe_resp.variable;
baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
} else {
baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
elements = mgmt->u.beacon.variable;
}
if (baselen > skb->len)
return;
ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
return;
bss = ieee80211_bss_info_update(local, rx_status,
mgmt, skb->len, &elems,
channel);
if (bss)
ieee80211_rx_bss_put(local, bss);
}
static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
enum nl80211_bss_scan_width scan_width)
{
memset(chandef, 0, sizeof(*chandef));
switch (scan_width) {
case NL80211_BSS_CHAN_WIDTH_5:
chandef->width = NL80211_CHAN_WIDTH_5;
break;
case NL80211_BSS_CHAN_WIDTH_10:
chandef->width = NL80211_CHAN_WIDTH_10;
break;
default:
chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
break;
}
}
/* return false if no more work */
static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
{
struct cfg80211_scan_request *req = local->scan_req;
struct cfg80211_chan_def chandef;
enum ieee80211_band band;
int i, ielen, n_chans;
if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
return false;
do {
if (local->hw_scan_band == IEEE80211_NUM_BANDS)
return false;
band = local->hw_scan_band;
n_chans = 0;
for (i = 0; i < req->n_channels; i++) {
if (req->channels[i]->band == band) {
local->hw_scan_req->channels[n_chans] =
req->channels[i];
n_chans++;
}
}
local->hw_scan_band++;
} while (!n_chans);
local->hw_scan_req->n_channels = n_chans;
ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
local->hw_scan_ies_bufsize,
req->ie, req->ie_len, band,
req->rates[band], &chandef);
local->hw_scan_req->ie_len = ielen;
local->hw_scan_req->no_cck = req->no_cck;
return true;
}
static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
{
struct ieee80211_local *local = hw_to_local(hw);
bool hw_scan = local->ops->hw_scan;
bool was_scanning = local->scanning;
lockdep_assert_held(&local->mtx);
/*
* It's ok to abort a not-yet-running scan (that
* we have one at all will be verified by checking
* local->scan_req next), but not to complete it
* successfully.
*/
if (WARN_ON(!local->scanning && !aborted))
aborted = true;
if (WARN_ON(!local->scan_req))
return;
if (hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
int rc;
rc = drv_hw_scan(local,
rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx)),
local->hw_scan_req);
if (rc == 0)
return;
}
kfree(local->hw_scan_req);
local->hw_scan_req = NULL;
if (local->scan_req != local->int_scan_req)
cfg80211_scan_done(local->scan_req, aborted);
local->scan_req = NULL;
rcu_assign_pointer(local->scan_sdata, NULL);
local->scanning = 0;
local->scan_chandef.chan = NULL;
/* Set power back to normal operating levels. */
ieee80211_hw_config(local, 0);
if (!hw_scan) {
ieee80211_configure_filter(local);
drv_sw_scan_complete(local);
ieee80211_offchannel_return(local);
}
mac80211: tell driver when idle When we aren't doing anything in mac80211, we can turn off much of the hardware, depending on the driver/hw. Not doing anything, aka being idle, means: * no monitor interfaces * no AP/mesh/wds interfaces * any station interfaces are in DISABLED state * any IBSS interfaces aren't trying to be in a network * we aren't trying to scan By creating a new function that verifies these conditions and calling it at strategic points where the states of those conditions change, we can easily make mac80211 tell the driver when we are idle to save power. Additionally, this fixes a small quirk where a recalculated powersave state is passed to the driver even if the hardware is about to stopped completely. This patch intentionally doesn't touch radio_enabled because that is currently implemented to be a soft rfkill which is inappropriate here when we need to be able to wake up with low latency. One thing I'm not entirely sure about is this: phy0: device no longer idle - in use wlan0: direct probe to AP 00:11:24:91:07:4d try 1 wlan0 direct probe responded wlan0: authenticate with AP 00:11:24:91:07:4d wlan0: authenticated > phy0: device now idle > phy0: device no longer idle - in use wlan0: associate with AP 00:11:24:91:07:4d wlan0: RX AssocResp from 00:11:24:91:07:4d (capab=0x401 status=0 aid=1) wlan0: associated Is it appropriate to go into idle state for a short time when we have just authenticated, but not associated yet? This happens only with the userspace SME, because we cannot really know how long it will wait before asking us to associate. Would going idle after a short timeout be more appropriate? We may need to revisit this, depending on what happens. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-04-29 10:26:17 +00:00
ieee80211_recalc_idle(local);
ieee80211_mlme_notify_scan_completed(local);
ieee80211_ibss_notify_scan_completed(local);
ieee80211_mesh_notify_scan_completed(local);
if (was_scanning)
ieee80211_start_next_roc(local);
}
void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
{
struct ieee80211_local *local = hw_to_local(hw);
trace_api_scan_completed(local, aborted);
set_bit(SCAN_COMPLETED, &local->scanning);
if (aborted)
set_bit(SCAN_ABORTED, &local->scanning);
ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
}
EXPORT_SYMBOL(ieee80211_scan_completed);
static int ieee80211_start_sw_scan(struct ieee80211_local *local)
{
/* Software scan is not supported in multi-channel cases */
if (local->use_chanctx)
return -EOPNOTSUPP;
/*
* Hardware/driver doesn't support hw_scan, so use software
* scanning instead. First send a nullfunc frame with power save
* bit on so that AP will buffer the frames for us while we are not
* listening, then send probe requests to each channel and wait for
* the responses. After all channels are scanned, tune back to the
* original channel and send a nullfunc frame with power save bit
* off to trigger the AP to send us all the buffered frames.
*
* Note that while local->sw_scanning is true everything else but
* nullfunc frames and probe requests will be dropped in
* ieee80211_tx_h_check_assoc().
*/
drv_sw_scan_start(local);
local->leave_oper_channel_time = jiffies;
local->next_scan_state = SCAN_DECISION;
local->scan_channel_idx = 0;
ieee80211_offchannel_stop_vifs(local);
/* ensure nullfunc is transmitted before leaving operating channel */
ieee80211_flush_queues(local, NULL);
ieee80211_configure_filter(local);
/* We need to set power level at maximum rate for scanning. */
ieee80211_hw_config(local, 0);
ieee80211_queue_delayed_work(&local->hw,
&local->scan_work, 0);
return 0;
}
static bool ieee80211_can_scan(struct ieee80211_local *local,
struct ieee80211_sub_if_data *sdata)
{
if (local->radar_detect_enabled)
return false;
if (!list_empty(&local->roc_list))
return false;
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
return false;
return true;
}
void ieee80211_run_deferred_scan(struct ieee80211_local *local)
{
lockdep_assert_held(&local->mtx);
if (!local->scan_req || local->scanning)
return;
if (!ieee80211_can_scan(local,
rcu_dereference_protected(
local->scan_sdata,
lockdep_is_held(&local->mtx))))
return;
ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
round_jiffies_relative(0));
}
static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
unsigned long *next_delay)
{
int i;
struct ieee80211_sub_if_data *sdata;
enum ieee80211_band band = local->hw.conf.chandef.chan->band;
u32 tx_flags;
tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
if (local->scan_req->no_cck)
tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
sdata = rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx));
for (i = 0; i < local->scan_req->n_ssids; i++)
ieee80211_send_probe_req(
sdata, NULL,
local->scan_req->ssids[i].ssid,
local->scan_req->ssids[i].ssid_len,
local->scan_req->ie, local->scan_req->ie_len,
local->scan_req->rates[band], false,
tx_flags, local->hw.conf.chandef.chan, true);
/*
* After sending probe requests, wait for probe responses
* on the channel.
*/
*next_delay = IEEE80211_CHANNEL_TIME;
local->next_scan_state = SCAN_DECISION;
}
static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
struct cfg80211_scan_request *req)
{
struct ieee80211_local *local = sdata->local;
int rc;
lockdep_assert_held(&local->mtx);
if (local->scan_req)
return -EBUSY;
if (!ieee80211_can_scan(local, sdata)) {
/* wait for the work to finish/time out */
local->scan_req = req;
rcu_assign_pointer(local->scan_sdata, sdata);
return 0;
}
if (local->ops->hw_scan) {
u8 *ies;
local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN +
local->scan_ies_len +
req->ie_len;
local->hw_scan_req = kmalloc(
sizeof(*local->hw_scan_req) +
req->n_channels * sizeof(req->channels[0]) +
local->hw_scan_ies_bufsize, GFP_KERNEL);
if (!local->hw_scan_req)
return -ENOMEM;
local->hw_scan_req->ssids = req->ssids;
local->hw_scan_req->n_ssids = req->n_ssids;
ies = (u8 *)local->hw_scan_req +
sizeof(*local->hw_scan_req) +
req->n_channels * sizeof(req->channels[0]);
local->hw_scan_req->ie = ies;
local->hw_scan_req->flags = req->flags;
local->hw_scan_band = 0;
/*
* After allocating local->hw_scan_req, we must
* go through until ieee80211_prep_hw_scan(), so
* anything that might be changed here and leave
* this function early must not go after this
* allocation.
*/
}
local->scan_req = req;
rcu_assign_pointer(local->scan_sdata, sdata);
if (local->ops->hw_scan) {
__set_bit(SCAN_HW_SCANNING, &local->scanning);
} else if ((req->n_channels == 1) &&
(req->channels[0] == local->_oper_chandef.chan)) {
/*
* If we are scanning only on the operating channel
* then we do not need to stop normal activities
*/
unsigned long next_delay;
__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
ieee80211_recalc_idle(local);
/* Notify driver scan is starting, keep order of operations
* same as normal software scan, in case that matters. */
drv_sw_scan_start(local);
ieee80211_configure_filter(local); /* accept probe-responses */
/* We need to ensure power level is at max for scanning. */
ieee80211_hw_config(local, 0);
if ((req->channels[0]->flags &
IEEE80211_CHAN_NO_IR) ||
!local->scan_req->n_ssids) {
next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
} else {
ieee80211_scan_state_send_probe(local, &next_delay);
next_delay = IEEE80211_CHANNEL_TIME;
}
/* Now, just wait a bit and we are all done! */
ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
next_delay);
return 0;
} else {
/* Do normal software scan */
__set_bit(SCAN_SW_SCANNING, &local->scanning);
}
mac80211: tell driver when idle When we aren't doing anything in mac80211, we can turn off much of the hardware, depending on the driver/hw. Not doing anything, aka being idle, means: * no monitor interfaces * no AP/mesh/wds interfaces * any station interfaces are in DISABLED state * any IBSS interfaces aren't trying to be in a network * we aren't trying to scan By creating a new function that verifies these conditions and calling it at strategic points where the states of those conditions change, we can easily make mac80211 tell the driver when we are idle to save power. Additionally, this fixes a small quirk where a recalculated powersave state is passed to the driver even if the hardware is about to stopped completely. This patch intentionally doesn't touch radio_enabled because that is currently implemented to be a soft rfkill which is inappropriate here when we need to be able to wake up with low latency. One thing I'm not entirely sure about is this: phy0: device no longer idle - in use wlan0: direct probe to AP 00:11:24:91:07:4d try 1 wlan0 direct probe responded wlan0: authenticate with AP 00:11:24:91:07:4d wlan0: authenticated > phy0: device now idle > phy0: device no longer idle - in use wlan0: associate with AP 00:11:24:91:07:4d wlan0: RX AssocResp from 00:11:24:91:07:4d (capab=0x401 status=0 aid=1) wlan0: associated Is it appropriate to go into idle state for a short time when we have just authenticated, but not associated yet? This happens only with the userspace SME, because we cannot really know how long it will wait before asking us to associate. Would going idle after a short timeout be more appropriate? We may need to revisit this, depending on what happens. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-04-29 10:26:17 +00:00
ieee80211_recalc_idle(local);
if (local->ops->hw_scan) {
WARN_ON(!ieee80211_prep_hw_scan(local));
rc = drv_hw_scan(local, sdata, local->hw_scan_req);
} else
rc = ieee80211_start_sw_scan(local);
if (rc) {
kfree(local->hw_scan_req);
local->hw_scan_req = NULL;
local->scanning = 0;
mac80211: tell driver when idle When we aren't doing anything in mac80211, we can turn off much of the hardware, depending on the driver/hw. Not doing anything, aka being idle, means: * no monitor interfaces * no AP/mesh/wds interfaces * any station interfaces are in DISABLED state * any IBSS interfaces aren't trying to be in a network * we aren't trying to scan By creating a new function that verifies these conditions and calling it at strategic points where the states of those conditions change, we can easily make mac80211 tell the driver when we are idle to save power. Additionally, this fixes a small quirk where a recalculated powersave state is passed to the driver even if the hardware is about to stopped completely. This patch intentionally doesn't touch radio_enabled because that is currently implemented to be a soft rfkill which is inappropriate here when we need to be able to wake up with low latency. One thing I'm not entirely sure about is this: phy0: device no longer idle - in use wlan0: direct probe to AP 00:11:24:91:07:4d try 1 wlan0 direct probe responded wlan0: authenticate with AP 00:11:24:91:07:4d wlan0: authenticated > phy0: device now idle > phy0: device no longer idle - in use wlan0: associate with AP 00:11:24:91:07:4d wlan0: RX AssocResp from 00:11:24:91:07:4d (capab=0x401 status=0 aid=1) wlan0: associated Is it appropriate to go into idle state for a short time when we have just authenticated, but not associated yet? This happens only with the userspace SME, because we cannot really know how long it will wait before asking us to associate. Would going idle after a short timeout be more appropriate? We may need to revisit this, depending on what happens. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-04-29 10:26:17 +00:00
ieee80211_recalc_idle(local);
local->scan_req = NULL;
rcu_assign_pointer(local->scan_sdata, NULL);
}
return rc;
}
static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
{
/*
* TODO: channel switching also consumes quite some time,
* add that delay as well to get a better estimation
*/
if (chan->flags & IEEE80211_CHAN_NO_IR)
return IEEE80211_PASSIVE_CHANNEL_TIME;
return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
}
static void ieee80211_scan_state_decision(struct ieee80211_local *local,
unsigned long *next_delay)
{
bool associated = false;
bool tx_empty = true;
bool bad_latency;
struct ieee80211_sub_if_data *sdata;
struct ieee80211_channel *next_chan;
enum mac80211_scan_state next_scan_state;
/*
* check if at least one STA interface is associated,
* check if at least one STA interface has pending tx frames
* and grab the lowest used beacon interval
*/
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
if (sdata->vif.type == NL80211_IFTYPE_STATION) {
if (sdata->u.mgd.associated) {
associated = true;
if (!qdisc_all_tx_empty(sdata->dev)) {
tx_empty = false;
break;
}
}
}
}
mutex_unlock(&local->iflist_mtx);
next_chan = local->scan_req->channels[local->scan_channel_idx];
/*
* we're currently scanning a different channel, let's
* see if we can scan another channel without interfering
* with the current traffic situation.
*
mac80211: improve latency and throughput while software scanning Patch vastly improve latency while scanning. Slight throughput improvements were observed as well. Is intended for improve performance of voice and video applications, when scan is periodically requested by user space (i.e. default NetworkManager behaviour). Patch remove latency requirement based on PM_QOS_NETWORK_LATENCY, this value is 2000 seconds by default (i.e. approximately 0.5 hour !?!). Also remove listen interval requirement, which based on beaconing and depending on BSS parameters. It can make we stay off-channel for a second or more. Instead try to offer the best latency that we could, i.e. be off-channel no longer than PASSIVE channel scan time: 125 ms. That mean we will scan two ACTIVE channels and go back to on-channel, and one PASSIVE channel, and go back to on-channel. Patch also decrease PASSIVE channel scan time to about 110 ms. As drawback patch increase overall scan time. On my tests, when scanning both 2GHz and 5GHz bands, scanning time increase from 5 seconds up to 10 seconds. Since that increase happen only when we are associated, I think it can be acceptable. If eventually better scan time is needed for situations when we lose signal and quickly need to decide to which AP roam, additional scan flag or parameter can be introduced. I tested patch by doing: while true; do iw dev wlan0 scan; sleep 3; done > /dev/null and ping -i0.2 -c 1000 HOST on remote and local machine, results are as below: * Ping from local periodically scanning machine to AP: Unpatched: rtt min/avg/max/mdev = 0.928/24.946/182.135/36.873 ms Patched: rtt min/avg/max/mdev = 0.928/19.678/150.845/33.130 ms * Ping from remote machine to periodically scanning machine: Unpatched: rtt min/avg/max/mdev = 1.637/120.683/709.139/164.337 ms Patched: rtt min/avg/max/mdev = 1.807/26.893/201.435/40.284 ms Throughput measured by scp show following results. * Upload to periodically scanning machine: Unpatched: 3.9MB/s 03:15 Patched: 4.3MB/s 02:58 * Download from periodically scanning machine: Unpatched: 5.5MB/s 02:17 Patched: 6.2MB/s 02:02 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-23 11:32:45 +00:00
* Keep good latency, do not stay off-channel more than 125 ms.
*/
bad_latency = time_after(jiffies +
mac80211: improve latency and throughput while software scanning Patch vastly improve latency while scanning. Slight throughput improvements were observed as well. Is intended for improve performance of voice and video applications, when scan is periodically requested by user space (i.e. default NetworkManager behaviour). Patch remove latency requirement based on PM_QOS_NETWORK_LATENCY, this value is 2000 seconds by default (i.e. approximately 0.5 hour !?!). Also remove listen interval requirement, which based on beaconing and depending on BSS parameters. It can make we stay off-channel for a second or more. Instead try to offer the best latency that we could, i.e. be off-channel no longer than PASSIVE channel scan time: 125 ms. That mean we will scan two ACTIVE channels and go back to on-channel, and one PASSIVE channel, and go back to on-channel. Patch also decrease PASSIVE channel scan time to about 110 ms. As drawback patch increase overall scan time. On my tests, when scanning both 2GHz and 5GHz bands, scanning time increase from 5 seconds up to 10 seconds. Since that increase happen only when we are associated, I think it can be acceptable. If eventually better scan time is needed for situations when we lose signal and quickly need to decide to which AP roam, additional scan flag or parameter can be introduced. I tested patch by doing: while true; do iw dev wlan0 scan; sleep 3; done > /dev/null and ping -i0.2 -c 1000 HOST on remote and local machine, results are as below: * Ping from local periodically scanning machine to AP: Unpatched: rtt min/avg/max/mdev = 0.928/24.946/182.135/36.873 ms Patched: rtt min/avg/max/mdev = 0.928/19.678/150.845/33.130 ms * Ping from remote machine to periodically scanning machine: Unpatched: rtt min/avg/max/mdev = 1.637/120.683/709.139/164.337 ms Patched: rtt min/avg/max/mdev = 1.807/26.893/201.435/40.284 ms Throughput measured by scp show following results. * Upload to periodically scanning machine: Unpatched: 3.9MB/s 03:15 Patched: 4.3MB/s 02:58 * Download from periodically scanning machine: Unpatched: 5.5MB/s 02:17 Patched: 6.2MB/s 02:02 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-23 11:32:45 +00:00
ieee80211_scan_get_channel_time(next_chan),
local->leave_oper_channel_time + HZ / 8);
if (associated && !tx_empty) {
if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
next_scan_state = SCAN_ABORT;
else
next_scan_state = SCAN_SUSPEND;
mac80211: improve latency and throughput while software scanning Patch vastly improve latency while scanning. Slight throughput improvements were observed as well. Is intended for improve performance of voice and video applications, when scan is periodically requested by user space (i.e. default NetworkManager behaviour). Patch remove latency requirement based on PM_QOS_NETWORK_LATENCY, this value is 2000 seconds by default (i.e. approximately 0.5 hour !?!). Also remove listen interval requirement, which based on beaconing and depending on BSS parameters. It can make we stay off-channel for a second or more. Instead try to offer the best latency that we could, i.e. be off-channel no longer than PASSIVE channel scan time: 125 ms. That mean we will scan two ACTIVE channels and go back to on-channel, and one PASSIVE channel, and go back to on-channel. Patch also decrease PASSIVE channel scan time to about 110 ms. As drawback patch increase overall scan time. On my tests, when scanning both 2GHz and 5GHz bands, scanning time increase from 5 seconds up to 10 seconds. Since that increase happen only when we are associated, I think it can be acceptable. If eventually better scan time is needed for situations when we lose signal and quickly need to decide to which AP roam, additional scan flag or parameter can be introduced. I tested patch by doing: while true; do iw dev wlan0 scan; sleep 3; done > /dev/null and ping -i0.2 -c 1000 HOST on remote and local machine, results are as below: * Ping from local periodically scanning machine to AP: Unpatched: rtt min/avg/max/mdev = 0.928/24.946/182.135/36.873 ms Patched: rtt min/avg/max/mdev = 0.928/19.678/150.845/33.130 ms * Ping from remote machine to periodically scanning machine: Unpatched: rtt min/avg/max/mdev = 1.637/120.683/709.139/164.337 ms Patched: rtt min/avg/max/mdev = 1.807/26.893/201.435/40.284 ms Throughput measured by scp show following results. * Upload to periodically scanning machine: Unpatched: 3.9MB/s 03:15 Patched: 4.3MB/s 02:58 * Download from periodically scanning machine: Unpatched: 5.5MB/s 02:17 Patched: 6.2MB/s 02:02 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-23 11:32:45 +00:00
} else if (associated && bad_latency) {
next_scan_state = SCAN_SUSPEND;
} else {
next_scan_state = SCAN_SET_CHANNEL;
}
local->next_scan_state = next_scan_state;
*next_delay = 0;
}
static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
unsigned long *next_delay)
{
int skip;
struct ieee80211_channel *chan;
enum nl80211_bss_scan_width oper_scan_width;
skip = 0;
chan = local->scan_req->channels[local->scan_channel_idx];
local->scan_chandef.chan = chan;
local->scan_chandef.center_freq1 = chan->center_freq;
local->scan_chandef.center_freq2 = 0;
switch (local->scan_req->scan_width) {
case NL80211_BSS_CHAN_WIDTH_5:
local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
break;
case NL80211_BSS_CHAN_WIDTH_10:
local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
break;
case NL80211_BSS_CHAN_WIDTH_20:
/* If scanning on oper channel, use whatever channel-type
* is currently in use.
*/
oper_scan_width = cfg80211_chandef_to_scan_width(
&local->_oper_chandef);
if (chan == local->_oper_chandef.chan &&
oper_scan_width == local->scan_req->scan_width)
local->scan_chandef = local->_oper_chandef;
else
local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
break;
}
if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
skip = 1;
/* advance state machine to next channel/band */
local->scan_channel_idx++;
if (skip) {
/* if we skip this channel return to the decision state */
local->next_scan_state = SCAN_DECISION;
return;
}
/*
* Probe delay is used to update the NAV, cf. 11.1.3.2.2
* (which unfortunately doesn't say _why_ step a) is done,
* but it waits for the probe delay or until a frame is
* received - and the received frame would update the NAV).
* For now, we do not support waiting until a frame is
* received.
*
* In any case, it is not necessary for a passive scan.
*/
if (chan->flags & IEEE80211_CHAN_NO_IR ||
!local->scan_req->n_ssids) {
*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
local->next_scan_state = SCAN_DECISION;
return;
}
/* active scan, send probes */
*next_delay = IEEE80211_PROBE_DELAY;
local->next_scan_state = SCAN_SEND_PROBE;
}
static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
unsigned long *next_delay)
{
/* switch back to the operating channel */
local->scan_chandef.chan = NULL;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
/* disable PS */
ieee80211_offchannel_return(local);
*next_delay = HZ / 5;
/* afterwards, resume scan & go to next channel */
local->next_scan_state = SCAN_RESUME;
}
static void ieee80211_scan_state_resume(struct ieee80211_local *local,
unsigned long *next_delay)
{
ieee80211_offchannel_stop_vifs(local);
if (local->ops->flush) {
ieee80211_flush_queues(local, NULL);
*next_delay = 0;
} else
*next_delay = HZ / 10;
/* remember when we left the operating channel */
local->leave_oper_channel_time = jiffies;
/* advance to the next channel to be scanned */
local->next_scan_state = SCAN_SET_CHANNEL;
}
void ieee80211_scan_work(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, scan_work.work);
struct ieee80211_sub_if_data *sdata;
unsigned long next_delay = 0;
bool aborted;
mutex_lock(&local->mtx);
sdata = rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx));
/* When scanning on-channel, the first-callback means completed. */
if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
goto out_complete;
}
if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
goto out_complete;
}
if (!sdata || !local->scan_req)
goto out;
if (local->scan_req && !local->scanning) {
struct cfg80211_scan_request *req = local->scan_req;
int rc;
local->scan_req = NULL;
rcu_assign_pointer(local->scan_sdata, NULL);
rc = __ieee80211_start_scan(sdata, req);
if (rc) {
/* need to complete scan in cfg80211 */
local->scan_req = req;
aborted = true;
goto out_complete;
} else
goto out;
}
/*
* as long as no delay is required advance immediately
* without scheduling a new work
*/
do {
if (!ieee80211_sdata_running(sdata)) {
aborted = true;
goto out_complete;
}
switch (local->next_scan_state) {
case SCAN_DECISION:
/* if no more bands/channels left, complete scan */
if (local->scan_channel_idx >= local->scan_req->n_channels) {
aborted = false;
goto out_complete;
}
ieee80211_scan_state_decision(local, &next_delay);
break;
case SCAN_SET_CHANNEL:
ieee80211_scan_state_set_channel(local, &next_delay);
break;
case SCAN_SEND_PROBE:
ieee80211_scan_state_send_probe(local, &next_delay);
break;
case SCAN_SUSPEND:
ieee80211_scan_state_suspend(local, &next_delay);
break;
case SCAN_RESUME:
ieee80211_scan_state_resume(local, &next_delay);
break;
case SCAN_ABORT:
aborted = true;
goto out_complete;
}
} while (next_delay == 0);
ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
goto out;
out_complete:
__ieee80211_scan_completed(&local->hw, aborted);
out:
mutex_unlock(&local->mtx);
}
int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
struct cfg80211_scan_request *req)
{
int res;
mutex_lock(&sdata->local->mtx);
res = __ieee80211_start_scan(sdata, req);
mutex_unlock(&sdata->local->mtx);
return res;
}
int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
const u8 *ssid, u8 ssid_len,
struct ieee80211_channel *chan,
enum nl80211_bss_scan_width scan_width)
{
struct ieee80211_local *local = sdata->local;
int ret = -EBUSY;
enum ieee80211_band band;
mutex_lock(&local->mtx);
/* busy scanning */
if (local->scan_req)
goto unlock;
/* fill internal scan request */
if (!chan) {
int i, max_n;
int n_ch = 0;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
if (!local->hw.wiphy->bands[band])
continue;
max_n = local->hw.wiphy->bands[band]->n_channels;
for (i = 0; i < max_n; i++) {
struct ieee80211_channel *tmp_ch =
&local->hw.wiphy->bands[band]->channels[i];
if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
IEEE80211_CHAN_DISABLED))
continue;
local->int_scan_req->channels[n_ch] = tmp_ch;
n_ch++;
}
}
if (WARN_ON_ONCE(n_ch == 0))
goto unlock;
local->int_scan_req->n_channels = n_ch;
} else {
if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
IEEE80211_CHAN_DISABLED)))
goto unlock;
local->int_scan_req->channels[0] = chan;
local->int_scan_req->n_channels = 1;
}
local->int_scan_req->ssids = &local->scan_ssid;
local->int_scan_req->n_ssids = 1;
local->int_scan_req->scan_width = scan_width;
memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
local->int_scan_req->ssids[0].ssid_len = ssid_len;
ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
unlock:
mutex_unlock(&local->mtx);
return ret;
}
/*
* Only call this function when a scan can't be queued -- under RTNL.
*/
void ieee80211_scan_cancel(struct ieee80211_local *local)
{
/*
* We are canceling software scan, or deferred scan that was not
* yet really started (see __ieee80211_start_scan ).
*
* Regarding hardware scan:
* - we can not call __ieee80211_scan_completed() as when
* SCAN_HW_SCANNING bit is set this function change
* local->hw_scan_req to operate on 5G band, what race with
* driver which can use local->hw_scan_req
*
* - we can not cancel scan_work since driver can schedule it
* by ieee80211_scan_completed(..., true) to finish scan
*
* Hence we only call the cancel_hw_scan() callback, but the low-level
* driver is still responsible for calling ieee80211_scan_completed()
* after the scan was completed/aborted.
*/
mutex_lock(&local->mtx);
if (!local->scan_req)
goto out;
/*
* We have a scan running and the driver already reported completion,
* but the worker hasn't run yet or is stuck on the mutex - mark it as
* cancelled.
*/
if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
test_bit(SCAN_COMPLETED, &local->scanning)) {
set_bit(SCAN_HW_CANCELLED, &local->scanning);
goto out;
}
if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
/*
* Make sure that __ieee80211_scan_completed doesn't trigger a
* scan on another band.
*/
set_bit(SCAN_HW_CANCELLED, &local->scanning);
if (local->ops->cancel_hw_scan)
drv_cancel_hw_scan(local,
rcu_dereference_protected(local->scan_sdata,
lockdep_is_held(&local->mtx)));
goto out;
}
/*
* If the work is currently running, it must be blocked on
* the mutex, but we'll set scan_sdata = NULL and it'll
* simply exit once it acquires the mutex.
*/
cancel_delayed_work(&local->scan_work);
/* and clean up */
__ieee80211_scan_completed(&local->hw, true);
out:
mutex_unlock(&local->mtx);
}
int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
struct cfg80211_sched_scan_request *req)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_sched_scan_ies sched_scan_ies = {};
struct cfg80211_chan_def chandef;
int ret, i, iebufsz;
iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
local->scan_ies_len + req->ie_len;
lockdep_assert_held(&local->mtx);
if (!local->ops->sched_scan_start)
return -ENOTSUPP;
for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
if (!local->hw.wiphy->bands[i])
continue;
sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
if (!sched_scan_ies.ie[i]) {
ret = -ENOMEM;
goto out_free;
}
ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
sched_scan_ies.len[i] =
ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
iebufsz, req->ie, req->ie_len,
i, (u32) -1, &chandef);
}
ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
if (ret == 0) {
rcu_assign_pointer(local->sched_scan_sdata, sdata);
local->sched_scan_req = req;
}
out_free:
while (i > 0)
kfree(sched_scan_ies.ie[--i]);
if (ret) {
/* Clean in case of failure after HW restart or upon resume. */
rcu_assign_pointer(local->sched_scan_sdata, NULL);
local->sched_scan_req = NULL;
}
return ret;
}
int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
struct cfg80211_sched_scan_request *req)
{
struct ieee80211_local *local = sdata->local;
int ret;
mutex_lock(&local->mtx);
if (rcu_access_pointer(local->sched_scan_sdata)) {
mutex_unlock(&local->mtx);
return -EBUSY;
}
ret = __ieee80211_request_sched_scan_start(sdata, req);
mutex_unlock(&local->mtx);
return ret;
}
int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
int ret = 0;
mutex_lock(&local->mtx);
if (!local->ops->sched_scan_stop) {
ret = -ENOTSUPP;
goto out;
}
/* We don't want to restart sched scan anymore. */
local->sched_scan_req = NULL;
if (rcu_access_pointer(local->sched_scan_sdata))
drv_sched_scan_stop(local, sdata);
out:
mutex_unlock(&local->mtx);
return ret;
}
void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
trace_api_sched_scan_results(local);
cfg80211_sched_scan_results(hw->wiphy);
}
EXPORT_SYMBOL(ieee80211_sched_scan_results);
void ieee80211_sched_scan_stopped_work(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local,
sched_scan_stopped_work);
mutex_lock(&local->mtx);
if (!rcu_access_pointer(local->sched_scan_sdata)) {
mutex_unlock(&local->mtx);
return;
}
rcu_assign_pointer(local->sched_scan_sdata, NULL);
/* If sched scan was aborted by the driver. */
local->sched_scan_req = NULL;
mutex_unlock(&local->mtx);
cfg80211_sched_scan_stopped(local->hw.wiphy);
}
void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
trace_api_sched_scan_stopped(local);
schedule_work(&local->sched_scan_stopped_work);
}
EXPORT_SYMBOL(ieee80211_sched_scan_stopped);