service.sh

#!/system/bin/sh
# Do NOT assume where your module will be located.
# ALWAYS use $MODDIR if you need to know where this script
# and module is placed.
# This will make sure your module will still work
# if Magisk change its mount point in the future
MODDIR=${0%/*}

# This script will be executed in late_start service mode
if [ -a /system/etc/resolv.conf ]; then
	mkdir -p $MODDIR/system/etc/
	printf "nameserver 8.8.8.8\nnameserver 8.8.4.4" >> $MODDIR/system/etc/resolv.conf
	chmod 644 $MODDIR/system/etc/resolv.conf
fi

iptables -t nat -A OUTPUT -p tcp --dport 53 -j DNAT --to-destination 8.8.8.8:53
iptables -t nat -A OUTPUT -p udp --dport 53 -j DNAT --to-destination 8.8.4.4:53
iptables -t nat -I OUTPUT -p tcp --dport 53 -j DNAT --to-destination 8.8.8.8:53
iptables -t nat -I OUTPUT -p udp --dport 53 -j DNAT --to-destination 8.8.4.4:53