On 17-11-2016 17:15, Dan Williams wrote:
> On Thu, 2016-11-17 at 11:39 +0000, Arend van Spriel wrote:
>> Add distance and its variance to the BSS structure so drivers
>> may provide RTT information for BSS instances found during
>> scanning.
>>
>> Reviewed-by: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx>
>> Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@xxxxxxxxxxx
>> m>
>> Reviewed-by: Franky Lin <franky.lin@xxxxxxxxxxxx>
>> Signed-off-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>
>> ---
>> include/net/cfg80211.h | 11 +++++++++++
>> include/uapi/linux/nl80211.h | 6 ++++++
>> net/wireless/nl80211.c | 8 ++++++++
>> net/wireless/scan.c | 2 ++
>> 4 files changed, 27 insertions(+)
>>
>> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
>> index 2019310..d1217da 100644
>> --- a/include/net/cfg80211.h
>> +++ b/include/net/cfg80211.h
>> @@ -1675,6 +1675,9 @@ enum cfg80211_signal_type {
>> * @scan_width: scan width that was used
>> * @signal: signal strength value, according to the wiphy's
>> * signal type
>> + * @distance: distance to AP with %parent_bssid in centimeters. Zero
>> + * value indicates this is undetermined.
>> + * @var_distance: variance of %distance indicating accurracy.
>
> "accuracy" without the second 'r'.
>
> Also, what unit is the variance in? Needs more documentation.
The term variance here is the standard statistical term. You can read
more info here [1]. As distance is in centimeters, the variance of the
distance is in square centimeters. I can add that.
Regards,
Arend
[1] http://www.mathsisfun.com/data/standard-deviation.html
> Dan
>
>> * @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
>> @@ -1691,6 +1694,8 @@ struct cfg80211_inform_bss {
>> struct ieee80211_channel *chan;
>> enum nl80211_bss_scan_width scan_width;
>> s32 signal;
>> + u32 distance;
>> + u32 var_distance;
>> u64 boottime_ns;
>> u64 parent_tsf;
>> u8 parent_bssid[ETH_ALEN] __aligned(2);
>> @@ -1737,6 +1742,9 @@ struct cfg80211_bss_ies {
>> * that holds the beacon data. @beacon_ies is still valid, of
>> course, and
>> * points to the same data as hidden_beacon_bss->beacon_ies
>> in that case.
>> * @signal: signal strength value (type depends on the wiphy's
>> signal_type)
>> + * @distance: distance to AP with %parent_bssid in centimeters. Zero
>> + * value indicates this is undetermined.
>> + * @var_distance: variance of %distance indicating accurracy.
>> * @priv: private area for driver use, has at least wiphy-
>>> bss_priv_size bytes
>> */
>> struct cfg80211_bss {
>> @@ -1756,6 +1764,9 @@ struct cfg80211_bss {
>>
>> u8 bssid[ETH_ALEN];
>>
>> + u32 distance;
>> + u32 var_distance;
>> +
>> u8 priv[0] __aligned(sizeof(void *));
>> };
>>
>> diff --git a/include/uapi/linux/nl80211.h
>> b/include/uapi/linux/nl80211.h
>> index 259c9c7..7e935f6 100644
>> --- a/include/uapi/linux/nl80211.h
>> +++ b/include/uapi/linux/nl80211.h
>> @@ -3651,6 +3651,10 @@ enum nl80211_bss_scan_width {
>> * @NL80211_BSS_PARENT_BSSID. (u64).
>> * @NL80211_BSS_PARENT_BSSID: the BSS according to which
>> @NL80211_BSS_PARENT_TSF
>> * is set.
>> + * @NL80211_BSS_DISTANCE: distance to AP with
>> @NL80211_BSS_PARENT_BSSID in
>> + * centimeters (u32).
>> + * @NL80211_BSS_VARIANCE_DISTANCE: variance of @NL80211_BSS_DISTANCE
>> value (u32).
>> + *
>> * @__NL80211_BSS_AFTER_LAST: internal
>> * @NL80211_BSS_MAX: highest BSS attribute
>> */
>> @@ -3674,6 +3678,8 @@ enum nl80211_bss {
>> NL80211_BSS_PAD,
>> NL80211_BSS_PARENT_TSF,
>> NL80211_BSS_PARENT_BSSID,
>> + NL80211_BSS_DISTANCE,
>> + NL80211_BSS_VARIANCE_DISTANCE,
>>
>> /* keep last */
>> __NL80211_BSS_AFTER_LAST,
>> diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
>> index 24ab199..ffce566 100644
>> --- a/net/wireless/nl80211.c
>> +++ b/net/wireless/nl80211.c
>> @@ -7515,6 +7515,14 @@ static int nl80211_send_bss(struct sk_buff
>> *msg, struct netlink_callback *cb,
>> intbss->ts_boottime, NL80211_BSS_PAD))
>> goto nla_put_failure;
>>
>> + if (res->distance && nla_put_u32(msg, NL80211_BSS_DISTANCE,
>> + res->distance))
>> + goto nla_put_failure;
>> +
>> + if (res->var_distance && nla_put_u32(msg,
>> NL80211_BSS_VARIANCE_DISTANCE,
>> + res->var_distance))
>> + 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))
>> diff --git a/net/wireless/scan.c b/net/wireless/scan.c
>> index b5bd58d..afda1f9 100644
>> --- a/net/wireless/scan.c
>> +++ b/net/wireless/scan.c
>> @@ -973,6 +973,8 @@ struct cfg80211_bss *
>> tmp.pub.signal = data->signal;
>> tmp.pub.beacon_interval = beacon_interval;
>> tmp.pub.capability = capability;
>> + tmp.pub.distance = data->distance;
>> + tmp.pub.var_distance = data->var_distance;
>> tmp.ts_boottime = data->boottime_ns;
>>
>> /*
