hostapd: correct 802.11r options

> SHORT:

for an absolute minimal working IEEE 802.11r, `option ieee80211r '1'` and `mobility_domain` are all that are needed

everything else is optional

> LONG:

IEEE 802.11r has *many sub-options* inside it's hostapd block of options

in LEDE, we have a *UCI special option* (option ieee80211r '1') that is not present in hostapd.conf and it *enables* these hostapd.conf sub-options

hostapd.conf sub-options' default values do *not* enable a working IEEE 802.11r configuration

`ft_psk_generate_local 1` from man:

> This avoids use of PMK-R1 push/pull from other APs with FT-PSK networks as the required information (PSK and other session data) is already locally available.

---------------------------------------------------------------------------------

1) it would be logical, that *UCI special option* `option ieee80211r '1'` actually enables a *default working* IEEE 802.11r from the start, with minimal sub-options defined

2) if we agree on this logic, it would be best that we start with a default value of 1 in `ft_psk_generate_local 1`

if it's 0 (previous default), user anyway has to provide unique `r1_key_holder` `r0kh` and `r1kh` as they are not locally generated

if per BSS, `ft_psk_generate_local 1` is the new default value left unchanged by user,
previous default value of `r1_key_holder` is left unchanged by user and `r0kh` and `r1kh` are not provided by user, default configuration of `option ieee80211r '1'` is in a **non-working or kind of working** default state of IEEE 802.11r

3) then default values of these are not wanted/needed anymore (they can only break something):
`r0_key_lifetime 1000`
`r1_key_holder "00004f577274"`

4) also then, this value *wants* to be 0:
`pmk_r1_push 0`

5) also then lastly, these *want* to be left empty:
`r0kh`
`r1kh`

4) `nasid` is mandatory for a working IEEE 802.11r, so a check here would be nice.
nasid needs to be unique per AP, so it can atleast be made from hostname per AP

5) ALL this does NOT break behaviour in our `option ieee80211r '1'`, it only disables mistakes and supercharges it

Signed-off-by: Gospod Nassa <devianca@gmail.com>

package/network/services/hostapd/files/hostapd.sh

@@ -383,37 +383,42 @@ hostapd_set_bss_options() {
 	}
 
 	if [ "$wpa" -ge "1" ]; then
-		json_get_vars ieee80211r
+		json_get_vars ieee80211r mobility_domain
 		set_default ieee80211r 0
 
-		if [ "$ieee80211r" -gt "0" ]; then
-			json_get_vars mobility_domain r0_key_lifetime r1_key_holder \
-				reassociation_deadline pmk_r1_push ft_psk_generate_local ft_over_ds
-			json_get_values r0kh r0kh
-			json_get_values r1kh r1kh
-
-			set_default mobility_domain "4f57"
-			set_default r0_key_lifetime 10000
-			set_default r1_key_holder "00004f577274"
-			set_default reassociation_deadline 1000
-			set_default pmk_r1_push 0
-			set_default ft_psk_generate_local 0
+		if [ "$ieee80211r" -gt "0" ] && [ -n "$mobility_domain" ]; then
+			json_get_vars ft_psk_generate_local ft_over_ds reassociation_deadline
+
+			set_default ft_psk_generate_local 1
 			set_default ft_over_ds 1
+			set_default reassociation_deadline 1000
 
 			append bss_conf "mobility_domain=$mobility_domain" "$N"
-			append bss_conf "r0_key_lifetime=$r0_key_lifetime" "$N"
-			append bss_conf "r1_key_holder=$r1_key_holder" "$N"
-			append bss_conf "reassociation_deadline=$reassociation_deadline" "$N"
-			append bss_conf "pmk_r1_push=$pmk_r1_push" "$N"
 			append bss_conf "ft_psk_generate_local=$ft_psk_generate_local" "$N"
 			append bss_conf "ft_over_ds=$ft_over_ds" "$N"
-
-			for kh in $r0kh; do
-				append bss_conf "r0kh=${kh//,/ }" "$N"
-			done
-			for kh in $r1kh; do
-				append bss_conf "r1kh=${kh//,/ }" "$N"
-			done
+			append bss_conf "reassociation_deadline=$reassociation_deadline" "$N"
+			[ -n "$nasid" ] || append bss_conf "nas_identifier=$(uci get system.@system[0].hostname)" "$N"
+
+			if [ "$ft_psk_generate_local" -eq "0" ]; then
+				json_get_vars r0_key_lifetime r1_key_holder pmk_r1_push
+				json_get_values r0kh r0kh
+				json_get_values r1kh r1kh
+
+				set_default r0_key_lifetime 10000
+				set_default r1_key_holder "00004f577274"
+				set_default pmk_r1_push 0
+
+				append bss_conf "r0_key_lifetime=$r0_key_lifetime" "$N"
+				append bss_conf "r1_key_holder=$r1_key_holder" "$N"
+				append bss_conf "pmk_r1_push=$pmk_r1_push" "$N"
+
+				for kh in $r0kh; do
+					append bss_conf "r0kh=${kh//,/ }" "$N"
+				done
+				for kh in $r1kh; do
+					append bss_conf "r1kh=${kh//,/ }" "$N"
+				done
+			fi
 		fi
 
 		hostapd_append_wpa_key_mgmt