#!/bin/bash

# Export the path
PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin
export PATH

# Set the time / date locale to kernel default
export LC_TIME=C

# Set some variables
CNT=0
FILE=""
LASTMOD=""
#PROXY="http://Your_Proxy_Here:Your_Proxy_Port_Here/"
TMPDATE=$(date +%s)
URL=""
ZONE="Your_Zone_Here"
ZONEFILE="Your_Zone_File_Here"


getlastmod()
{
	# Does the file exist
	if [ -f $FILE ]
	then
	        # Figure out file date and convert to HTTP Last-Modified date
	        LASTMOD=$(date -u +"%a, %d %b %Y %H:%M:%S GMT" \
	        --date="$(ls -l --time-style=+"%a, %d %b %Y %H:%M:%S %z" $FILE | \
	        awk '{print $6 " " $7 " " $8 " " $9 " " $10 " " $11}' | \
	        head -n1)")
	else
	        # Use epoch zero
	        LASTMOD="Thu, 01 Jan 1970 00:00:00 GMT"
	fi
	echo "Current lastmod: ${LASTMOD}"
}

getfile()
{
	# Get the file if newer then LASTMOD
	TMP="/tmp/${FILE}-${TMPDATE}-${$}"
	if ( curl -f -H "If-Modified-Since: ${LASTMOD}" -o "${TMP}" -R "${URL}" )
	then
		# No errors
		if [ -s "${TMP}" ]
		then
			# Non zero
			rm "${FILE}.old"
			mv "${FILE}" "${FILE}.old"
			mv "${TMP}" "${FILE}"
			chown root:staff "${FILE}"
			let CNT+=1
			echo "New ${FILE}"
		else
			rm "${TMP}"
			echo "${FILE} not modified"
		fi
	else
		echo "Error fetching ${URL}"
	fi
}

if [ -d /var/local/lib/bind/ ]
then
	cd /var/local/lib/bind/
else
	echo "Create /var/local/lib/bind/"
	exit 1
fi

#FILE="drop.lasso"
#URL="https://www.spamhaus.org/drop/drop.lasso"
FILE="drop.txt"
URL="https://www.spamhaus.org/drop/drop.txt"
getlastmod
getfile

FILE="edrop.txt"
URL="https://www.spamhaus.org/drop/edrop.txt"
getlastmod
getfile

FILE="dropv6.txt"
URL="https://www.spamhaus.org/drop/dropv6.txt"
getlastmod
getfile

if [ $CNT -eq 0 ]
then
	# No changes
	echo "No change in ${ZONEFILE}"
	exit 0
fi

DATE=$( date +%Y%m%d01 )

rm "${ZONEFILE}.old"
mv "${ZONEFILE}" "${ZONEFILE}.old"
cat /etc/bind/local-rbl-head | sed -e "s/SERIAL/${DATE}/g" > "${ZONEFILE}"
#cat drop.lasso | procdrop >> "${ZONEFILE}"
cat drop.txt | procdrop >> "${ZONEFILE}"
echo "" >> "${ZONEFILE}"
cat edrop.txt  | procdrop >> "${ZONEFILE}"
echo "" >> "${ZONEFILE}"
cat dropv6.txt | procdrop >> "${ZONEFILE}"
echo "" >> "${ZONEFILE}"

if ( named-checkzone "${ZONE}" "${ZONEFILE}" > /dev/null )
then
	if ( diff "${ZONEFILE}" "/etc/bind/${ZONEFILE}" > /dev/null )
	then
		echo "No change in ${ZONEFILE}"
	else
		cp "${ZONEFILE}" /etc/bind/
		echo "New version of ${ZONEFILE}"
		echo "${CNT} new files"
	fi
fi