fix(wireless): Fix undefined behavior when wireless radio is 6g band capable

Falling back on 5g band when the radio is configured by default for 6g band.
6g band is restricted to indoor uses in most places, and require wpa3.

Author: VGDSpehar

packages/lime-system/files/usr/lib/lua/lime/wireless.lua

@@ -67,6 +67,29 @@ function wireless.is5Ghz(radio)
 	return devModes and (devModes.a or devModes.ac)
 end
 
+function wireless.is6Ghz(radio)
+	local config = require("lime.config")
+	local uci = config.get_uci_cursor()
+	wifi_band = uci:get('wireless', radio, 'band')
+	if wifi_band then return wifi_band=='6g' end
+	return false
+end
+
+function wireless.getRadioBand(radioName)
+	if wireless.is5Ghz(radioName) then
+		return '5ghz'
+	end
+	if wireless.is6Ghz(radioName) then
+		--! currently untested and reserved for indoor use
+		-- let's default to 5ghz for now
+		-- TODO: test 6g band and decide a path forward with
+		local uci = config.get_uci_cursor()
+		uci:set("wireless", radioName, "band", "5g") 
+		return '5ghz'
+	end
+	return '2ghz'
+end
+
 wireless.availableModes = { adhoc=true, ap=true, apname=true, apbb=true, ieee80211s=true }
 function wireless.isMode(m)
 	return wireless.availableModes[m]
@@ -165,7 +188,7 @@ function wireless.configure()
 	local allRadios = wireless.scandevices()
 	for _,radio in pairs(allRadios) do
 		local radioName = radio[".name"]
-		local radioBand = wireless.is5Ghz(radioName) and '5ghz' or '2ghz'
+		local radioBand = wireless.getRadioBand(radioName) 
 		local radioOptions = specificRadios[radioName] or {}
 		local bandOptions = config.get_all(radioBand) or {}
 		local options = config.get_all("wifi")