survey: implement Nl80211SurveyInfo

[Sh3Rm4n]

This adds the ability to trigger and parse the NL80211_ATTR_SURVEY_INFO similar to iw DEVICE survey dump.

I've added and example, which does dump the survey info. The device was set to AP mode via iw before

iw DEVICE set type __ap

The wifi chip I used is the Intel AX210NGW and the kernel loaded the firmware version 89. With this I was able to read out noise measurement values.

Depends on #23

[cathay4t]

This seems no fit for a crate.

[Sh3Rm4n]

Removed

[cathay4t]

This seems not ideal for crate

[Sh3Rm4n]

Removed.

[cathay4t]

Could you provide a script for me to try it out?

[Sh3Rm4n]

Could you provide a script for me to try it out?

Of course. As I've said, I'm using the Intel AX210 wifi card to obtain noise levels, but I'm sure there are other cards, which provide some detail in the survey info.

I've ran the script on a raspberry pi (kernel version 6.11 and iw version 6.9) setting it into AP mode with root privilages

# as wpa_supplicant is running by default on the raspberry pi stop it
systemctl stop wpa_supplicant
pkill wpa_supplicant
# now configure the Wifi Card (the Intel AX210 is enumrated as wlan1 for me)
ip link set wlan1 down
iw wlan set type __ap
ip link set wlan0 up
# this should now show the WLAN card in AP mode
iw wlan0 info

# now to trigger a scan to botain the survey info, run the nl80211_trigger_scan example (
cargo run --example nl80211_trigger_scan 4
# after that the dump survey should provide some info
cargo run --example dump_nl80211_survey 4

The iw approximate equivalent for the cargo examples would be

iw wlan1 scan passive
iw wlan1 survey dump

[Sh3Rm4n]

I've also added optional support for SurveyRadioStats in 10c1d6f similar to the --radio flag in iw.

For that I'd had to add the Nl80211Survey builder. Similar to scan the dump method can now receive all kinds of attributes instead of only the interface index and instead the builder is used to specify the correct attributes. I'm not sure if this is to open, but I've used scan as a reference.

[cathay4t]

Could you add a document line indicate even kernel said NL80211_SURVEY_INFO_NOISE is u8, the iw and real world still treat it as i8.

[cathay4t]

i8::cast_unsigned()

[Sh3Rm4n]

This seems to be a nightly feature https://doc.rust-lang.org/std/primitive.u8.html#method.cast_signed/, should I still use it? I'd prefer not to use nightly features, if no other nightly feature is used yet.

[Sh3Rm4n]

Actually, this was just stabilized, so I'll use it

[Sh3Rm4n]

I've used cast_signed and uncast_signed instead of the as cast in the latest revision.

[cathay4t]

Please also squash these commits into single one. Thanks.

[Sh3Rm4n]

I've squashed the commits and added the comment as you suggested.