mac80211.sh: fix deadlock on configuring multiple PHYs simultaneously

When hitting a timing window where ubus configuration calls are hitting hostapd
and wpa_supplicant simultaneously, they can deadlock waiting for each other.
Fix this by using a lock around the ubus calls.

Signed-off-by: Felix Fietkau <[email protected]>

package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh

@@ -19,6 +19,10 @@ wdev_tool() {
 	ucode /usr/share/hostap/wdev.uc "$@"
 }
 
+ubus_call() {
+	flock /var/run/hostapd.lock ubus call "$@"
+}
+
 drv_mac80211_init_device_config() {
 	hostapd_common_add_device_config
 
@@ -903,7 +907,7 @@ wpa_supplicant_set_config() {
 		ubus wait_for wpa_supplicant
 	}
 
-	local supplicant_res="$(ubus call wpa_supplicant config_set "$data")"
+	local supplicant_res="$(ubus_call wpa_supplicant config_set "$data")"
 	ret="$?"
 	[ "$ret" != 0 -o -z "$supplicant_res" ] && wireless_setup_vif_failed WPA_SUPPLICANT_FAILED
 
@@ -913,12 +917,12 @@ wpa_supplicant_set_config() {
 
 hostapd_set_config() {
 	[ -n "$hostapd_ctrl" ] || {
-		ubus call hostapd config_set '{ "phy": "'"$phy"'", "config": "", "prev_config": "'"${hostapd_conf_file}.prev"'" }' > /dev/null
+		ubus_call hostapd config_set '{ "phy": "'"$phy"'", "config": "", "prev_config": "'"${hostapd_conf_file}.prev"'" }' > /dev/null
 		return 0;
 	}
 
 	ubus wait_for hostapd
-	local hostapd_res="$(ubus call hostapd config_set "{ \"phy\": \"$phy\", \"config\":\"${hostapd_conf_file}\", \"prev_config\": \"${hostapd_conf_file}.prev\"}")"
+	local hostapd_res="$(ubus_call hostapd config_set "{ \"phy\": \"$phy\", \"config\":\"${hostapd_conf_file}\", \"prev_config\": \"${hostapd_conf_file}.prev\"}")"
 	ret="$?"
 	[ "$ret" != 0 -o -z "$hostapd_res" ] && {
 		wireless_setup_failed HOSTAPD_START_FAILED
@@ -933,7 +937,7 @@ wpa_supplicant_start() {
 
 	[ -n "$wpa_supp_init" ] || return 0
 
-	ubus call wpa_supplicant config_set '{ "phy": "'"$phy"'" }' > /dev/null
+	ubus_call wpa_supplicant config_set '{ "phy": "'"$phy"'" }' > /dev/null
 }
 
 mac80211_setup_supplicant() {
@@ -1041,8 +1045,8 @@ mac80211_reset_config() {
 	local phy="$1"
 
 	hostapd_conf_file="/var/run/hostapd-$phy.conf"
-	ubus call hostapd config_set '{ "phy": "'"$phy"'", "config": "", "prev_config": "'"$hostapd_conf_file"'" }' > /dev/null
-	ubus call wpa_supplicant config_set '{ "phy": "'"$phy"'", "config": [] }' > /dev/null
+	ubus_call hostapd config_set '{ "phy": "'"$phy"'", "config": "", "prev_config": "'"$hostapd_conf_file"'" }' > /dev/null
+	ubus_call wpa_supplicant config_set '{ "phy": "'"$phy"'", "config": [] }' > /dev/null
 	wdev_tool "$phy" set_config '{}'
 }