Commit 2e076f19 authored by Johannes Berg's avatar Johannes Berg Committed by Johannes Berg
Browse files

nl80211: add scan features for improved scan privacy 



Add the scan flags for randomized SN and minimized probe request
content for improved scan privacy.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
parent 45ad6834

include/uapi/linux/nl80211.h

+15 −0
Original line number Diff line number Diff line
@@ -5133,6 +5133,11 @@ enum nl80211_feature_flags { 
 *	support to nl80211.

 * @NL80211_EXT_FEATURE_TXQS: Driver supports FQ-CoDel-enabled intermediate

 *      TXQs.

 * @NL80211_EXT_FEATURE_SCAN_RANDOM_SN: Driver/device supports randomizing the

 *	SN in probe request frames if requested by %NL80211_SCAN_FLAG_RANDOM_SN.

 * @NL80211_EXT_FEATURE_SCAN_MIN_PREQ_CONTENT: Driver/device can omit all data

 *	except for supported rates from the probe request content if requested

 *	by the %NL80211_SCAN_FLAG_MIN_PREQ_CONTENT flag.

 *

 * @NUM_NL80211_EXT_FEATURES: number of extended features.

 * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
@@ -5167,6 +5172,8 @@ enum nl80211_ext_feature_index { 
	NL80211_EXT_FEATURE_CONTROL_PORT_OVER_NL80211,

	NL80211_EXT_FEATURE_DATA_ACK_SIGNAL_SUPPORT,

	NL80211_EXT_FEATURE_TXQS,

	NL80211_EXT_FEATURE_SCAN_RANDOM_SN,

	NL80211_EXT_FEATURE_SCAN_MIN_PREQ_CONTENT,



	/* add new features before the definition below */

	NUM_NL80211_EXT_FEATURES,
@@ -5272,6 +5279,12 @@ enum nl80211_timeout_reason { 
 *	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.

 * @NL80211_SCAN_FLAG_RANDOM_SN: randomize the sequence number in probe

 *	request frames from this scan to avoid correlation/tracking being

 *	possible.

 * @NL80211_SCAN_FLAG_MIN_PREQ_CONTENT: minimize probe request content to

 *	only have supported rates and no additional capabilities (unless

 *	added by userspace explicitly.)

 */

enum nl80211_scan_flags {

	NL80211_SCAN_FLAG_LOW_PRIORITY				= 1<<0,
@@ -5285,6 +5298,8 @@ enum nl80211_scan_flags { 
	NL80211_SCAN_FLAG_LOW_SPAN				= 1<<8,

	NL80211_SCAN_FLAG_LOW_POWER				= 1<<9,

	NL80211_SCAN_FLAG_HIGH_ACCURACY				= 1<<10,

	NL80211_SCAN_FLAG_RANDOM_SN				= 1<<11,

	NL80211_SCAN_FLAG_MIN_PREQ_CONTENT			= 1<<12,

};



/**

net/wireless/nl80211.c

+7 −1
Original line number Diff line number Diff line
@@ -6925,7 +6925,13 @@ nl80211_check_scan_flags(struct wiphy *wiphy, struct wireless_dev *wdev, 
				     NL80211_EXT_FEATURE_OCE_PROBE_REQ_DEFERRAL_SUPPRESSION) ||

	    !nl80211_check_scan_feat(wiphy, *flags,

				     NL80211_SCAN_FLAG_OCE_PROBE_REQ_HIGH_TX_RATE,

				     NL80211_EXT_FEATURE_OCE_PROBE_REQ_HIGH_TX_RATE))

				     NL80211_EXT_FEATURE_OCE_PROBE_REQ_HIGH_TX_RATE) ||

	    !nl80211_check_scan_feat(wiphy, *flags,

				     NL80211_SCAN_FLAG_RANDOM_SN,

				     NL80211_EXT_FEATURE_SCAN_RANDOM_SN) ||

	    !nl80211_check_scan_feat(wiphy, *flags,

				     NL80211_SCAN_FLAG_MIN_PREQ_CONTENT,

				     NL80211_EXT_FEATURE_SCAN_MIN_PREQ_CONTENT))

		return -EOPNOTSUPP;



	if (*flags & NL80211_SCAN_FLAG_RANDOM_ADDR) {