#!/bin/sh
# Make vnStat track this router's network devices without any hard-coded
# names: every netifd interface that is up (WAN, LAN, modem, VPN, ...) gets
# its L3 device added to the "interface" list in /etc/config/vnstat, which
# the vnstat2 init script feeds to "vnstat --add".
#
#   netstat-vnstat-track            add the devices of all interfaces that are up
#   netstat-vnstat-track <dev>...   add the given devices
#
# Set "option vnstat_autoadd '0'" in /etc/config/netstats to turn this off.

[ -x /usr/bin/vnstat ] || exit 0
[ "$(uci -q get netstats.@config[0].vnstat_autoadd)" = "0" ] && exit 0

valid_name() {
	case "$1" in
		""|lo|*[!A-Za-z0-9._-]*) return 1 ;;
	esac
	return 0
}

discover() {
	ubus call network.interface dump 2>/dev/null | \
		jsonfilter -e '@.interface[@.up=true].l3_device' 2>/dev/null
}

[ $# -gt 0 ] && devices="$*" || devices="$(discover)"
[ -n "$devices" ] || exit 0

lock /var/lock/netstat-vnstat-track

# vnstat2 ships "config vnstat" in /etc/config/vnstat; recreate it if missing.
touch /etc/config/vnstat
uci -q get vnstat.@vnstat[0] >/dev/null || uci -q add vnstat vnstat >/dev/null

tracked=" $(uci -q get vnstat.@vnstat[0].interface) "
changed=0
for dev in $devices; do
	valid_name "$dev" || continue
	case "$tracked" in *" $dev "*) continue ;; esac
	uci -q add_list vnstat.@vnstat[0].interface="$dev"
	tracked="$tracked$dev "
	changed=1
done

if [ "$changed" = 1 ]; then
	uci -q commit vnstat
	# reload runs "vnstat --add" for the list and sends SIGHUP so vnstatd
	# picks the new entries up straight away.
	if /etc/init.d/vnstat running 2>/dev/null; then
		/etc/init.d/vnstat reload >/dev/null 2>&1
	elif /etc/init.d/vnstat enabled 2>/dev/null; then
		/etc/init.d/vnstat start >/dev/null 2>&1
	fi
fi

lock -u /var/lock/netstat-vnstat-track
exit 0