dnsomatic

#!/bin/sh
#shellcheck disable=SC2018
#shellcheck disable=SC2019
#shellcheck source=/dev/null
#DNS-O-MATIC updater by maghuro 2020
APPNAME="DNSOMatic"
APPNAMEnorm="$(echo $APPNAME | tr 'A-Z' 'a-z')"
CFGdir="/jffs/addons/$APPNAMEnorm.d"
CFG="${CFGdir}/settings.cfg"
SCRIPTPATH="$(cd "$(dirname "$0")" >/dev/null 2>&1 || exit ; pwd -P)"
readonly CRIT="\\e[41m"
readonly ERR="\\e[31m"
readonly WARN="\\e[33m"
readonly PASS="\\e[32m"

#set -x

[ -f "/opt/bin/$APPNAMEnorm" ] || ln -s "$SCRIPTPATH/$0" "/opt/bin/$APPNAMEnorm" >/dev/null 2>&1

if [ ! -f "$CFG" ]; then
	if [ ! -d "$CFGdir" ]; then
		mkdir "$CFGdir"
		chmod 777 "$CFGdir"
	fi
	printf "" > "$CFG"
fi
. "$CFG"

# $1 = message to print, $2 = log level \\\ Thanks JackYaz
Print_Output(){
	logger -t "$APPNAME" "$1"
	printf "\\e[1m$2%s: $1\\e[0m\\n" "$APPNAME"
}

#set vars / $1 = var name, $2 = value
setvar(){
	grep -q "$1=" < "$CFG" || printf "%s=\"\"\n" "$1" >> "$CFG"
	sed -i "s/^$1=.*$/$1=\"$(echo "$2" | tr -d " ")\"/" "$CFG"
	. "$CFG"
}

if [ "$1" = "config" ]; then
	cat "$CFG"
	exit 0
fi

if [ "$1" = "set" ]; then
	if [ -n "$2" ] && [ -n "$3" ]; then
		var="$(echo $2 | tr 'a-z' 'A-Z')"
		setvar "$var" "$3"
		Print_Output "Setting \"$(echo "$var" | tr -d " ")=$(echo "$3" | tr -d " ")\"..."
		exit 0
	else
		echo "Missing args"
		exit 1
	fi
fi

if [ "$1" = "cron" ]; then
		if [ -z "$2" ] && [ -z "$RUNEACH" ]; then
			Print_Output "Please use \"$APPNAMEnorm cron X\" where X is the number in minutes for cronjob" "$ERR"
			exit 1
		elif [ -n "$2" ]; then
			setvar RUNEACH "$2"
		fi
	cru a "$APPNAME" "*/$RUNEACH * * * * $0"
	Print_Output "Creating cronjob to run every $RUNEACH minutes..." "$WARN"
	#shift 2
	cru a ${APPNAME}_first "$(date -D '%s' +'%M %H %d %m %a' -d $(($(date +%s)+200))) $0"
	exit 0
fi

if [ "$ABUSE" = "1" ]; then
	setvar ABUSE 2
	Print_Output "Last update was abusive, skipping this one..."
	exit 0
elif [ "$ABUSE" = "2" ]; then
	setvar ABUSE 0
	Print_Output "Last update was abusive, skipping this one also..."
	exit 0
fi

missing=0
for vars in USERNAME PASSWORD HOSTNAME; do
	if ! grep -q "$vars=" < "$CFG"; then
		missing=1
		Print_Output "Please use \"$APPNAMEnorm set $vars your_$(echo $vars | tr 'A-Z' 'a-z')\" before first run" "$CRIT"
	fi
done

[ "$missing" = 1 ] && exit 1

#check if curl (for the sake of...) and jq exists
FAILOVER=0
for app in curl jq; do
	if ! (which "$app" >/dev/null 2>&1); then
		Print_Output "$app not found, installing..." "$CRIT"
		opkg install "$app" >/dev/null 2>&1
		if ! (which "$app" >/dev/null 2>&1); then
			Print_Output "Can't download $app, exiting as it is required..." "$CRIT"
			which jq >/dev/null 2>&1 || FAILOVER=1
		fi
	fi
done

if [ "$1" = "init" ]; then
	Print_Output "Waiting 30 sec for first check..." "$WARN"
	sleep 30s
fi

if [ "$1" = "force" ]; then
	setvar CURRENTIP ""
	setvar CURRENTCOUNTRY ""
fi

which curl >/dev/null 2>&1 || exit 1

if [ -n "$2" ]; then
	NEWIP="$2"
	NEWCOUNTRY="$(echo "$3" | tr 'a-z' 'A-Z')"
elif [ "$FAILOVER" != 1 ]; then
	AIRVPN="$(curl -fs4 --retry 1 https://airvpn.org/api/whatismyip/)"
	NEWIP="$(jq -n "$AIRVPN" | jq -j .ip)"
	NEWCOUNTRY="$(jq -n "$AIRVPN" | jq -j .geo.code | tr 'a-z' 'A-Z')"
fi

[ -z "$NEWCOUNTRY" ] && NEWCOUNTRY="EARTH"

if [ -z "$NEWIP" ] || [ "$NEWIP" = "null" ]; then
	Print_Output "Can't retrieve IP Address from main source, trying failover..." "$ERR"
	NEWIP="$(curl -fs4 -- retry 1 https://api4.my-ip.io/ip)" #failover
	NEWCOUNTRY="FAILOVER"
fi
if [ -z "$NEWIP" ] || [ "$NEWIP" = "null" ]; then
	setvar CURRENTIP ""
	setvar CURRENTCOUNTRY ""
	Print_Output "Can't retrieve IP Address, stopping..." "$ERR"
	exit 1
else
	if [ "$NEWIP" != "$CURRENTIP" ]; then
		UPDATE="$(curl -fs4 --retry 8 -u "$USERNAME":"$PASSWORD" https://updates.dnsomatic.com/nic/update?hostname="$HOSTNAME"\&wildcard=NOCHG\&mx=NOCHG\&backmx=NOCHG\&myip="$NEWIP")"
		#if you need to curl another url to update another service, you can do it here, for example:
    #curl -fs4 --retry 8 "https://link-ip.nextdns.io/confid/presharedkey" -o /dev/null #NextDNS linked IP
		####
		if [ "$UPDATE" = "good $NEWIP" ] || [ "$UPDATE" = "nochg $NEWIP" ]; then
			if [ "$1" = "force" ]; then
				Print_Output "Forcing IP update to $NEWIP/$NEWCOUNTRY" "$PASS"
			elif [ -z "$CURRENTIP" ]; then
				Print_Output "Updating IP to $NEWIP/$NEWCOUNTRY" "$PASS"
			else
				Print_Output "Updating IP from $CURRENTIP/$CURRENTCOUNTRY to $NEWIP/$NEWCOUNTRY" "$PASS"
			fi
			setvar CURRENTIP "$NEWIP"
			setvar CURRENTCOUNTRY "$NEWCOUNTRY"
		elif [ "$UPDATE" = "abuse" ]; then
			setvar CURRENTIP ""
			setvar CURRENTCOUNTRY ""
			setvar ABUSE 1
			Print_Output "Abusing! Nothing updated. Next two crons will be skipped and next update forced" "$ERR"
		else
			setvar CURRENTIP ""
			setvar CURRENTCOUNTRY ""
			Print_Output "Error while updating: \"$UPDATE\". Next update will be forced" "$ERR"
		fi
	else
		[ "$PRINTNOTH" = 1 ] && Print_Output "Nothing to update. Current IP: $CURRENTIP/$CURRENTCOUNTRY" "$PASS"
	fi
fi

exit 0