#!/bin/sh
# in brmode & extmode, this script is used to monitor wireless link

. /lib/cfgmgr/cfgmgr.sh

brmode_wlg_linked() {
	[ "$(awk 'NR==3' /proc/sys/net/ath1/status)" = "RUN" ]
}

brmode_wla_linked() {
	[ "$(awk 'NR==3' /proc/sys/net/ath0/status)" = "RUN" ]
}

extmode_wlg_linked() {
	[ "$(awk 'NR==3' /proc/sys/net/ath1/status)" = "RUN" ]
}

extmode_wla_linked() {
	[ "$(awk 'NR==3' /proc/sys/net/ath0/status)" = "RUN" ]
}

extmode_wlg_fixup()
{
	oc echo "unable to estabilish extmode 2.4G wireless link !"
	local extchannel=$(/usr/sbin/extkit 2g scan | awk -v ssid=$(config get wlg_ext_ssid) '
	BEGIN {var = "\x22" ssid "\x22"}
	{ if ($1 == var) { print $2; exit } }
	')

	[ -n ${extchannel} -a "${extchannel}" != "$($CONFIG get wlg_ext_channel)" ] && {
		oc echo "new 2.4G ext channel : $extchannel !"
		$CONFIG set wlg_ext_channel="$extchannel" && $CONFIG commit
		/etc/init.d/wlan-common restart
	}
}

brmode_wlg_fixup() { oc echo "unable to estabilish brmode 2.4G wireless link !"; }
brmode_wla_fixup() { oc echo "unable to estabilish brmode 5G wireless link !"; }
extmode_wlg_fixup() { oc echo "unable to estabilish extmode 2.4G wireless link !"; }
extmode_wla_fixup() { oc echo "unable to estabilish extmode 5G wireless link !"; }

get_hostname() {
	cat /proc/sys/kernel/hostname
}

udhcpc_existed() {
	[ "x$(pidof udhcpc)" != "x" ]
}

# global variables : g_wl_linked means judge wireless link success or fail funtion.
# g_wl_fixup means wireless link failed. 
setup_global_variables_or_exit()
{
	case "$($CONFIG get i_opmode)" in
	brmode)
		if [ "$($CONFIG get bridge_band_choose)" = "5g" ]; then
			g_wl_linked=brmode_wla_linked
			g_wl_fixup=brmode_wla_fixup
		else
			g_wl_linked=brmode_wlg_linked
			g_wl_fixup=brmode_wlg_fixup
		fi
		;;
	extmode)
		if [ "x$($CONFIG get wla_ext_enabled)" = "x1" ]; then
			g_wl_linked=extmode_wla_linked
			g_wl_fixup=extmode_wla_fixup
		else
			g_wl_linked=extmode_wlg_linked
			g_wl_fixup=extmode_wlg_fixup
		fi
		;;
	*)
		echo "only for brmode or extmode !"
		exit
		;;
	esac
}

setup_global_variables_or_exit
g_udhcpc_h_arg="-h $(get_hostname)"
g_udhcpc_r_arg="-r $($CONFIG get ap_dhcp_ipaddr)"
oc echo "g_wl_linked=$g_wl_linked, g_wl_fixup=$g_wl_fixup"
oc echo "g_udhcpc_h_arg=$g_udhcpc_h_arg, g_udhcpc_r_arg=$g_udhcpc_r_arg"

tmp_on_time=0
tmp_off_time=0
newlinkstate=off
unlink_time=0
linkstate=off
while true; do
	#oc echo "xxxxxx on=$tmp_on_time, off=$tmp_off_time, s=$linkstate, ult=$unlink_time xxxxxx"
	sleep 5
	udhcpc_existed || udhcpc -a -b -i br0 "$g_udhcpc_h_arg" "$g_udhcpc_r_arg" &

	#Check if wireless link success and keep more than 20 sec then judge it final stable.
	if eval $g_wl_linked; then
		tmp_off_time=0; tmp_on_time=$(($tmp_on_time + 5))
		[ $tmp_on_time -ge 20 ] && tmp_on_time=0 && newlinkstate=on
	else
		tmp_on_time=0; tmp_off_time=$(($tmp_off_time + 5))
		[ $tmp_off_time -ge 10 ] && tmp_off_time=0 && newlinkstate=off
	fi

	if [ "$newlinkstate" = "on" ]; then
		[ "$linkstate" = "off" ] && linkstate=on && unlink_time=0 && killall -SIGUSR1 udhcpc
	else
		[ "$linkstate" = "on" ] && linkstate=off && killall -SIGUSR2 udhcpc
		unlink_time=$(( $unlink_time + 5 ))
		[ $unlink_time -ge 60 ] && unlink_time=0 && eval $g_wl_fixup
	fi
done