Commit 6e19bc4b authored by Dmitry Shmidt's avatar Dmitry Shmidt Committed by Johannes Berg
Browse files

nl80211: allow BSS data to include CLOCK_BOOTTIME timestamp 



For location and connectivity services, userspace would often like
to know the time when the BSS was last seen. The current "last seen"
value is calculated in a way that makes it less useful, especially
if the system suspended in the meantime.

Add the ability for the driver to report a real CLOCK_BOOTTIME stamp
that can then be reported to userspace (if present).

Drivers wishing to use this must be converted to the new API to call
cfg80211_inform_bss_data() or cfg80211_inform_bss_frame_data(). They
need to ensure the reported value is accurate enough even when the
frame might have been buffered in the device (e.g. firmware.)

Signed-off-by: default avatarDmitry Shmidt <dimitrysh@google.com>
[modified to use struct, inlines]
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 93f0490e

Documentation/DocBook/80211.tmpl

+3 −2
Original line number Diff line number Diff line
@@ -154,8 +154,9 @@ 
!Finclude/net/cfg80211.h cfg80211_scan_request

!Finclude/net/cfg80211.h cfg80211_scan_done

!Finclude/net/cfg80211.h cfg80211_bss

!Finclude/net/cfg80211.h cfg80211_inform_bss_width_frame

!Finclude/net/cfg80211.h cfg80211_inform_bss_width

!Finclude/net/cfg80211.h cfg80211_inform_bss

!Finclude/net/cfg80211.h cfg80211_inform_bss_frame_data

!Finclude/net/cfg80211.h cfg80211_inform_bss_data

!Finclude/net/cfg80211.h cfg80211_unlink_bss

!Finclude/net/cfg80211.h cfg80211_find_ie

!Finclude/net/cfg80211.h ieee80211_bss_get_ie

include/net/cfg80211.h

+76 −19
Original line number Diff line number Diff line
@@ -1575,6 +1575,26 @@ enum cfg80211_signal_type { 
	CFG80211_SIGNAL_TYPE_UNSPEC,

};



/**

 * struct cfg80211_inform_bss - BSS inform data

 * @chan: channel the frame was received on

 * @scan_width: scan width that was used

 * @signal: signal strength value, according to the wiphy's

 *	signal type

 * @boottime_ns: timestamp (CLOCK_BOOTTIME) when the information was

 *	received; should match the time when the frame was actually

 *	received by the device (not just by the host, in case it was

 *	buffered on the device) and be accurate to about 10ms.

 *	If the frame isn't buffered, just passing the return value of

 *	ktime_get_boot_ns() is likely appropriate.

 */

struct cfg80211_inform_bss {

	struct ieee80211_channel *chan;

	enum nl80211_bss_scan_width scan_width;

	s32 signal;

	u64 boottime_ns;

};



/**

 * struct cfg80211_bss_ie_data - BSS entry IE data

 * @tsf: TSF contained in the frame that carried these IEs
@@ -3958,14 +3978,11 @@ void cfg80211_sched_scan_stopped(struct wiphy *wiphy); 
void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy);



/**

 * cfg80211_inform_bss_width_frame - inform cfg80211 of a received BSS frame

 *

 * cfg80211_inform_bss_frame_data - inform cfg80211 of a received BSS frame

 * @wiphy: the wiphy reporting the BSS

 * @rx_channel: The channel the frame was received on

 * @scan_width: width of the control channel

 * @data: the BSS metadata

 * @mgmt: the management frame (probe response or beacon)

 * @len: length of the management frame

 * @signal: the signal strength, type depends on the wiphy's signal_type

 * @gfp: context flags

 *

 * This informs cfg80211 that BSS information was found and
@@ -3975,11 +3992,26 @@ void cfg80211_sched_scan_stopped_rtnl(struct wiphy *wiphy); 
 * Or %NULL on error.

 */

struct cfg80211_bss * __must_check

cfg80211_inform_bss_frame_data(struct wiphy *wiphy,

			       struct cfg80211_inform_bss *data,

			       struct ieee80211_mgmt *mgmt, size_t len,

			       gfp_t gfp);



static inline struct cfg80211_bss * __must_check

cfg80211_inform_bss_width_frame(struct wiphy *wiphy,

				struct ieee80211_channel *rx_channel,

				enum nl80211_bss_scan_width scan_width,

				struct ieee80211_mgmt *mgmt, size_t len,

				s32 signal, gfp_t gfp);

				s32 signal, gfp_t gfp)

{

	struct cfg80211_inform_bss data = {

		.chan = rx_channel,

		.scan_width = scan_width,

		.signal = signal,

	};



	return cfg80211_inform_bss_frame_data(wiphy, &data, mgmt, len, gfp);

}



static inline struct cfg80211_bss * __must_check

cfg80211_inform_bss_frame(struct wiphy *wiphy,
@@ -3987,9 +4019,13 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, 
			  struct ieee80211_mgmt *mgmt, size_t len,

			  s32 signal, gfp_t gfp)

{

	return cfg80211_inform_bss_width_frame(wiphy, rx_channel,

					       NL80211_BSS_CHAN_WIDTH_20,

					       mgmt, len, signal, gfp);

	struct cfg80211_inform_bss data = {

		.chan = rx_channel,

		.scan_width = NL80211_BSS_CHAN_WIDTH_20,

		.signal = signal,

	};



	return cfg80211_inform_bss_frame_data(wiphy, &data, mgmt, len, gfp);

}



/**
@@ -4006,11 +4042,10 @@ enum cfg80211_bss_frame_type { 
};



/**

 * cfg80211_inform_bss_width - inform cfg80211 of a new BSS

 * cfg80211_inform_bss_data - inform cfg80211 of a new BSS

 *

 * @wiphy: the wiphy reporting the BSS

 * @rx_channel: The channel the frame was received on

 * @scan_width: width of the control channel

 * @data: the BSS metadata

 * @ftype: frame type (if known)

 * @bssid: the BSSID of the BSS

 * @tsf: the TSF sent by the peer in the beacon/probe response (or 0)
@@ -4018,7 +4053,6 @@ enum cfg80211_bss_frame_type { 
 * @beacon_interval: the beacon interval announced by the peer

 * @ie: additional IEs sent by the peer

 * @ielen: length of the additional IEs

 * @signal: the signal strength, type depends on the wiphy's signal_type

 * @gfp: context flags

 *

 * This informs cfg80211 that BSS information was found and
@@ -4028,13 +4062,32 @@ enum cfg80211_bss_frame_type { 
 * Or %NULL on error.

 */

struct cfg80211_bss * __must_check

cfg80211_inform_bss_data(struct wiphy *wiphy,

			 struct cfg80211_inform_bss *data,

			 enum cfg80211_bss_frame_type ftype,

			 const u8 *bssid, u64 tsf, u16 capability,

			 u16 beacon_interval, const u8 *ie, size_t ielen,

			 gfp_t gfp);



static inline struct cfg80211_bss * __must_check

cfg80211_inform_bss_width(struct wiphy *wiphy,

			  struct ieee80211_channel *rx_channel,

			  enum nl80211_bss_scan_width scan_width,

			  enum cfg80211_bss_frame_type ftype,

			  const u8 *bssid, u64 tsf, u16 capability,

			  u16 beacon_interval, const u8 *ie, size_t ielen,

			  s32 signal, gfp_t gfp);

			  s32 signal, gfp_t gfp)

{

	struct cfg80211_inform_bss data = {

		.chan = rx_channel,

		.scan_width = scan_width,

		.signal = signal,

	};



	return cfg80211_inform_bss_data(wiphy, &data, ftype, bssid, tsf,

					capability, beacon_interval, ie, ielen,

					gfp);

}



static inline struct cfg80211_bss * __must_check

cfg80211_inform_bss(struct wiphy *wiphy,
@@ -4044,10 +4097,14 @@ cfg80211_inform_bss(struct wiphy *wiphy, 
		    u16 beacon_interval, const u8 *ie, size_t ielen,

		    s32 signal, gfp_t gfp)

{

	return cfg80211_inform_bss_width(wiphy, rx_channel,

					 NL80211_BSS_CHAN_WIDTH_20, ftype,

					 bssid, tsf, capability,

					 beacon_interval, ie, ielen, signal,

	struct cfg80211_inform_bss data = {

		.chan = rx_channel,

		.scan_width = NL80211_BSS_CHAN_WIDTH_20,

		.signal = signal,

	};



	return cfg80211_inform_bss_data(wiphy, &data, ftype, bssid, tsf,

					capability, beacon_interval, ie, ielen,

					gfp);

}

include/uapi/linux/nl80211.h

+4 −0
Original line number Diff line number Diff line
@@ -3364,6 +3364,9 @@ enum nl80211_bss_scan_width { 
 *	(not present if no beacon frame has been received yet)

 * @NL80211_BSS_PRESP_DATA: the data in @NL80211_BSS_INFORMATION_ELEMENTS and

 *	@NL80211_BSS_TSF is known to be from a probe response (flag attribute)

 * @NL80211_BSS_LAST_SEEN_BOOTTIME: CLOCK_BOOTTIME timestamp when this entry

 *	was last updated by a received frame. The value is expected to be

 *	accurate to about 10ms. (u64, nanoseconds)

 * @__NL80211_BSS_AFTER_LAST: internal

 * @NL80211_BSS_MAX: highest BSS attribute

 */
@@ -3383,6 +3386,7 @@ enum nl80211_bss { 
	NL80211_BSS_CHAN_WIDTH,

	NL80211_BSS_BEACON_TSF,

	NL80211_BSS_PRESP_DATA,

	NL80211_BSS_LAST_SEEN_BOOTTIME,



	/* keep last */

	__NL80211_BSS_AFTER_LAST,

net/wireless/core.h

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ struct cfg80211_internal_bss { 
	struct list_head list;

	struct list_head hidden_list;

	struct rb_node rbn;

	u64 ts_boottime;

	unsigned long ts;

	unsigned long refcount;

	atomic_t hold;

net/wireless/nl80211.c

+5 −0
Original line number Diff line number Diff line
@@ -6605,6 +6605,11 @@ static int nl80211_send_bss(struct sk_buff *msg, struct netlink_callback *cb, 
			jiffies_to_msecs(jiffies - intbss->ts)))

		goto nla_put_failure;



	if (intbss->ts_boottime &&

	    nla_put_u64(msg, NL80211_BSS_LAST_SEEN_BOOTTIME,

			intbss->ts_boottime))

		goto nla_put_failure;



	switch (rdev->wiphy.signal_type) {

	case CFG80211_SIGNAL_TYPE_MBM:

		if (nla_put_u32(msg, NL80211_BSS_SIGNAL_MBM, res->signal))

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