GL.iNet ddns update script [will associate your wan IP to puXXXXX.gl-inet.com where XXXXX are the latest 5 bytes of the mac address]

glddnsupdater.sh

#!/bin/sh

# OpenWRT support libs
. /lib/functions.sh
. /lib/functions/network.sh
. /usr/share/libubox/jshn.sh

ip_regex="[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}"
ddns=
code=
model=$(awk 'BEGIN{FS="-"} /machine/ {print tolower($2)}' /proc/cpuinfo)
if [ "$model" = "connect inet v1" ]; then
	model="6416"
	ddns=$(dd if=/dev/mtd0 bs=1 skip=$((0x1fc10)) count=7 2>/dev/null)
	code=$(dd if=/dev/mtd0 bs=1 skip=$((0x1fc20)) count=16 2>/dev/null)
elif [ "$model" = "ar150" -o "$model" = "ar300" -o "$model" = "mifi" ]; then
	ddns=$(dd if=/dev/mtd6 bs=1 skip=$((0x10)) count=7 2>/dev/null)
	code=$(dd if=/dev/mtd6 bs=1 skip=$((0x20)) count=16 2>/dev/null)
elif [ "$model" = "ar300m" ]; then
	ddns=$(dd if=/dev/mtd3 bs=1 skip=$((0x10)) count=7 2>/dev/null)
	code=$(dd if=/dev/mtd3 bs=1 skip=$((0x20)) count=16 2>/dev/null)
elif [ "$model" = "mt300a" -o "$model" = "mt300n" -o "$model" = "mt750" ]; then
	ddns=$(dd if=/dev/mtd2 bs=1 skip=$((0x4010)) count=7 2>/dev/null)
	code=$(dd if=/dev/mtd2 bs=1 skip=$((0x4020)) count=16 2>/dev/null)
fi

letter=$(printf "%x" "'${ddns:5:1}")
if [ "$letter" = "ff" ]; then
	ddns=${ddns:0:5}
else
	ddns=${ddns:0:7}
fi

port=$(uci get glconfig.general.port)
lastport=$port

monotonic_time()
{
	local uptime
	read uptime < /proc/uptime
	echo "${uptime%%.*}"
}
get_current_ip(){
	current_ip=$(wget -O - http://checkip.dyndns.org 2>/dev/null | grep -m 1 -o "$ip_regex")
	if [ -z "$current_ip" ]; then
		current_ip=$(wget -O - http://myip.com.tw/ 2>/dev/null | grep -m 1 -o "$ip_regex")
	fi
	echo "$current_ip"
}

verbose_echo()
{
	echo $1
}

get_wan_ip(){
	status=$(ifstatus wan)
	if [ "$status" = "Interface wan not found" ]; then
		status=$(ifstatus wwan)
	fi
	json_load "$status"
	json_select "ipv4_address"
	json_select 1
	json_get_var wan_ip "address"
	echo "$wan_ip"
}

#kill old process
if [ -d /var/run/dynamic_dns ]
then
	if [ -e "/var/run/dynamic_dns/gl.pid" ]
	then
		old_pid=$(cat /var/run/dynamic_dns/gl.pid)
		test_match=$(ps | grep "^[\t ]*$old_pid")
		verbose_echo "old process id exist"
		if [ -n "$test_match" ]
		then
			kill -9 $old_pid
		fi
	fi
else
	mkdir /var/run/dynamic_dns
fi
echo $$ > /var/run/dynamic_dns/gl.pid

#determine when the last update was
force_interval_seconds=$((24*60*60))
current_time=$(monotonic_time)
last_update=$(( $current_time - (2*$force_interval_seconds) ))
if [ -e "/var/run/dynamic_dns/gl.update" ]
then
	last_update=$(cat /var/run/dynamic_dns/gl.update)
fi
time_since_update=$(($current_time - $last_update))
verbose_echo "time_since_update = $human_time_since_update hours"

while [ true ]
do
	#please be note user may stop updating ddns in the middle
	config_load "glconfig"
	config_get ddns_enabled ddns enabled
	config_get lastip ddns lastip
	config_get port general port
	#if not eabled ddns, we will recheck 10 minutes later
	if [ "$ddns_enabled" != "1" ]
	then
		sleep $((10*60))
		continue
	fi
	registered_ip=$lastip

	current_ip=$(get_current_ip)
	wanip=$(get_wan_ip)
	if [ -z "$current_ip" ]; then
		sleep 10
		continue
	fi

	#if the router is not directly exposed to internet, request upnp
	if [ "$current_ip" != "$wanip" ]; then
		echo "not exposed to internet directly, need to update UPNP"
		/usr/bin/glupnpc nocheckip&
	else
		echo "exposed to internet directly, no need to update UPNP"
	fi

	current_time=$(monotonic_time)
	time_since_update=$(($current_time - $last_update))

	verbose_echo "current system ip = $current_ip"
	verbose_echo "registered domain ip = $registered_ip"

	if [ "$current_ip" != "$registered_ip" ] || [ "$lastport" != "$port" ] || [ $force_interval_seconds -lt $time_since_update ] || [ "$1" = "--force"  ]
	then
		verbose_echo "update necessary, performing update ..."
		final_url="http://www.gl-inet.com/ddnsregister.php?ddns=$ddns&code=$code&ip=$current_ip&port=$port&wanip=$wanip&model=$model"
		verbose_echo $final_url
		update_output=$(wget -O - "$final_url" 2>/dev/null)
		if [ "$update_output" != "Update Done:$current_ip" ]
		then
			verbose_echo "update faild, sleeping"
			sleep 300
			continue
		fi
		verbose_echo "Update Output:"
		verbose_echo "$update_output"
		verbose_echo ""

		current_time=$(monotonic_time)
		last_update=$current_time
		lastport=$port
		time_since_update='0'
		human_time=$(date)
		verbose_echo "update complete, time is: $human_time"

		echo "$last_update" > "/var/run/dynamic_dns/gl.update"
		$(uci set glconfig.ddns.lastip="$current_ip")
		$(uci set glconfig.ddns.updatetime="$human_time")
		$(uci commit glconfig)

	else
		human_time=$(date)
		human_time_since_update=$(( $time_since_update / ( 60 * 60 ) ))
		verbose_echo "update unnecessary"
		verbose_echo "time since last update = $human_time_since_update hours"
		verbose_echo "the time is now $human_time"
	fi

	sleep $((10*60))
done

return 0