#!/bin/sh
#
# @Author LI Zhuohuan <zixia@zixia.net>
# @Date 3/10/2015
#
# This script fix lost AP signal when STA fail.
# it runs background, loop & check.
# if STA fail, it disable STA and re-enable AP.
#
# I believe when wifi radio in both AP & STA(client) mode,
# the driver need to know which channel to use first.
# so AP will not functional until STA established the link.
# after STA link connect, AP will know and use the same channel that STA use.
# so AP have to wait, and there will no AP at all if STA setting error.
#

DEBUG=1
TIMEOUT=30
SLEEP=2

disable_sta() {
	n=`uci show wireless.@wifi-iface[99] 2>/dev/null | grep @wifi-iface | grep -v =wifi-iface | cut -d. -f2 | uniq | cut -d[ -f2 | cut -d] -f1 | sort | tail -1`
	[ $DEBUG -gt 0 ] && echo "disable_sta: found $n ifaces"

	ap=0
	while [ $n -ge 0 ]; do
		mode=`uci get wireless.@wifi-iface[$n].mode`
		echo "iface[$n] mode[$mode]"
	 	if [ X$mode == Xsta ]; then
	  		echo "deleting wifi-iface[$n] for it's in sta mode"
	  		uci delete wireless.@wifi-iface[$n]
	  		uci commit wireless
	 	elif [ X$mode == Xap ]; then
	  		echo "found wifi-iface[$n] in ap mode."
	  		ap=1
	 	fi
	 		let n=n-1
		done

	if [ $ap -eq 0 ]; then
	 	echo "adding wifi default ap..."
	 	uci add wireless wifi-iface
	 	uci set wireless.@wifi-iface[-1].device='radio0'
	 	uci set wireless.@wifi-iface[-1].network='lan'
	 	uci set wireless.@wifi-iface[-1].mode='ap'
	 	uci set wireless.@wifi-iface[-1].ssid='VoCore'
	 	uci set wireless.@wifi-iface[-1].encryption='none'
	 	uci commit wireless
	fi

	wifi up
}

sta_err=0

while [ 1 -gt 0 ]; do

	ifnames=`ubus call network.wireless status | grep ifname | cut -d\" -f4`

	for ifname in $ifnames ; do
		[ $DEBUG -gt 0 ] && echo "checking $ifname after sleep $SLEEP seconds..."
		iftype=`iw dev $ifname info | grep type | cut -d' ' -f2`
		[ $DEBUG -gt 0 ] && echo "checking $ifname 's type: $iftype"
		if [ X$iftype == Xmanaged ]; then
			ssid=`iw dev $ifname link | grep SSID | cut -d' ' -f 2`
			echo "ifname $ifname is STA mode, ssid[$ssid]"
			if [ X$ssid == "X" ]; then # AP mode disabled
				let sta_err=$sta_err+1
				echo "ifname $ifname not connected. err counter: $sta_err"
			else
				sta_err=0
			fi
		fi
	done

	sleep $SLEEP;

	let err_time=$sta_err*$SLEEP
	[ $DEBUG -gt 0 ] && [ $err_time -gt 0 ] && echo "err_time: $err_time"

	if [ $err_time -gt $TIMEOUT ]; then
		echo "*** STA connect timeout[$err_time]. disable STA mode now... ***"
		sleep 1
		disable_sta
		sta_err=0
	fi

done