Commit 5037a009 authored by Sunil Dutt's avatar Sunil Dutt Committed by Johannes Berg
Browse files

nl80211: Introduce scan flags to emphasize requested scan behavior 



This commit defines new scan flags (LOW_SPAN, LOW_POWER, HIGH_LATENCY)
to emphasize the requested scan behavior for the driver. These flags
are optional and are mutually exclusive. The implementation of the
respective functionality can be driver/hardware specific.

These flags can be used to control the compromise between how long
a scan takes, how much power it uses, and high accurate/complete
the scan is in finding the BSSs.

Signed-off-by: default avatarSunil Dutt <usdutt@qti.qualcomm.com>
Signed-off-by: default avatarJouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 6335698e

include/uapi/linux/nl80211.h

+27 −1
Original line number Diff line number Diff line
@@ -4945,6 +4945,9 @@ enum nl80211_feature_flags { 
 *	probe request tx deferral and suppression

 * @NL80211_EXT_FEATURE_MFP_OPTIONAL: Driver supports the %NL80211_MFP_OPTIONAL

 *	value in %NL80211_ATTR_USE_MFP.

 * @NL80211_EXT_FEATURE_LOW_SPAN_SCAN: Driver supports low span scan.

 * @NL80211_EXT_FEATURE_LOW_POWER_SCAN: Driver supports low power scan.

 * @NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN: Driver supports high accuracy scan.

 *

 * @NUM_NL80211_EXT_FEATURES: number of extended features.

 * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
@@ -4972,6 +4975,9 @@ enum nl80211_ext_feature_index { 
	NL80211_EXT_FEATURE_OCE_PROBE_REQ_HIGH_TX_RATE,

	NL80211_EXT_FEATURE_OCE_PROBE_REQ_DEFERRAL_SUPPRESSION,

	NL80211_EXT_FEATURE_MFP_OPTIONAL,

	NL80211_EXT_FEATURE_LOW_SPAN_SCAN,

	NL80211_EXT_FEATURE_LOW_POWER_SCAN,

	NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN,



	/* add new features before the definition below */

	NUM_NL80211_EXT_FEATURES,
@@ -5032,6 +5038,10 @@ enum nl80211_timeout_reason { 
 * of NL80211_CMD_TRIGGER_SCAN and NL80211_CMD_START_SCHED_SCAN

 * requests.

 *

 * NL80211_SCAN_FLAG_LOW_SPAN, NL80211_SCAN_FLAG_LOW_POWER, and

 * NL80211_SCAN_FLAG_HIGH_ACCURACY flags are exclusive of each other, i.e., only

 * one of them can be used in the request.

 *

 * @NL80211_SCAN_FLAG_LOW_PRIORITY: scan request has low priority

 * @NL80211_SCAN_FLAG_FLUSH: flush cache before scanning

 * @NL80211_SCAN_FLAG_AP: force a scan even if the interface is configured
@@ -5059,7 +5069,20 @@ enum nl80211_timeout_reason { 
 *	and suppression (if it has received a broadcast Probe Response frame,

 *	Beacon frame or FILS Discovery frame from an AP that the STA considers

 *	a suitable candidate for (re-)association - suitable in terms of

 *	SSID and/or RSSI

 *	SSID and/or RSSI.

 * @NL80211_SCAN_FLAG_LOW_SPAN: Span corresponds to the total time taken to

 *	accomplish the scan. Thus, this flag intends the driver to perform the

 *	scan request with lesser span/duration. It is specific to the driver

 *	implementations on how this is accomplished. Scan accuracy may get

 *	impacted with this flag.

 * @NL80211_SCAN_FLAG_LOW_POWER: This flag intends the scan attempts to consume

 *	optimal possible power. Drivers can resort to their specific means to

 *	optimize the power. Scan accuracy may get impacted with this flag.

 * @NL80211_SCAN_FLAG_HIGH_ACCURACY: Accuracy here intends to the extent of scan

 *	results obtained. Thus HIGH_ACCURACY scan flag aims to get maximum

 *	possible scan results. This flag hints the driver to use the best

 *	possible scan configuration to improve the accuracy in scanning.

 *	Latency and power use may get impacted with this flag.

 */

enum nl80211_scan_flags {

	NL80211_SCAN_FLAG_LOW_PRIORITY				= 1<<0,
@@ -5070,6 +5093,9 @@ enum nl80211_scan_flags { 
	NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP		= 1<<5,

	NL80211_SCAN_FLAG_OCE_PROBE_REQ_HIGH_TX_RATE		= 1<<6,

	NL80211_SCAN_FLAG_OCE_PROBE_REQ_DEFERRAL_SUPPRESSION	= 1<<7,

	NL80211_SCAN_FLAG_LOW_SPAN				= 1<<8,

	NL80211_SCAN_FLAG_LOW_POWER				= 1<<9,

	NL80211_SCAN_FLAG_HIGH_ACCURACY				= 1<<10,

};



/**

net/wireless/nl80211.c

+11 −2
Original line number Diff line number Diff line
@@ -6715,8 +6715,17 @@ nl80211_check_scan_flags(struct wiphy *wiphy, struct wireless_dev *wdev, 


	*flags = nla_get_u32(attrs[NL80211_ATTR_SCAN_FLAGS]);



	if ((*flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&

	    !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN))

	if (((*flags & NL80211_SCAN_FLAG_LOW_PRIORITY) &&

	     !(wiphy->features & NL80211_FEATURE_LOW_PRIORITY_SCAN)) ||

	    ((*flags & NL80211_SCAN_FLAG_LOW_SPAN) &&

	     !wiphy_ext_feature_isset(wiphy,

				      NL80211_EXT_FEATURE_LOW_SPAN_SCAN)) ||

	    ((*flags & NL80211_SCAN_FLAG_LOW_POWER) &&

	     !wiphy_ext_feature_isset(wiphy,

				      NL80211_EXT_FEATURE_LOW_POWER_SCAN)) ||

	    ((*flags & NL80211_SCAN_FLAG_HIGH_ACCURACY) &&

	     !wiphy_ext_feature_isset(wiphy,

				      NL80211_EXT_FEATURE_HIGH_ACCURACY_SCAN)))

		return -EOPNOTSUPP;



	if (*flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {

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