#dns_adblock.sh - poor man's adblock
# (c)2015 sorin@toXX.guru
#replace add servers with a local blank page
#this script works faster/better/cleaner if you have apache httpd configured to serve a null page in case of page not found
#just create an empty file 'touch /var/www/html/null.html', then in /etc/httpd/httpd.conf add/modify the line 'ErrorDocument 404 /null.html'
#define local variables
target=/var/named/data/blacklist
nullzone=/var/named/null.zone.file
namedconf=/etc/named.conf
whitelisted=/var/named/data/whitelisted.personal
blacklisted=/var/named/data/blacklisted.personal
namesrv=192.168.18.100
# if it's the first time we run this, add the right info into bind's configuration
if [ ! -f $nullzone ]; then
echo "\$TTL 86400 ; one day
@ IN SOA ads.nodomain. root. (
2015021505 ; serial
28800 ; refresh
7200 ; retry
864000 ; expiry
86400 ) ; minimum
NS nameserver
A $namesrv
@ IN A $namesrv
* IN A $namesrv" > $nullzone
fi
if ! grep -q $target $namedconf ; then
echo "conf not found"
echo " include \"$target\";" >> $namedconf
fi
# get the list of known adservers from yoyo.org, sanitize it and make it compatible with bind9
wget -q -O - 'http://pgl.yoyo.org/as/serverlist.php?hostformat=bindconfig&showintro=0' | tail -n+29 | head -n -6 | sed -e 's/{/IN {/g' -e '/_/d' > $target-new
# get a second list from mvps.org, sanitize it and add only the hostnames that were not given by yoyo.org
while read adhost; do
if ! grep -q $adhost $target-new ; then
echo "zone \"$adhost\" IN { type master; notify no; file \"null.zone.file\"; };" >> $target-new
fi
done < <(wget -q -O - http://www.mvps.org/winhelp2002/hosts.txt | sed -e '/^ *#/d;s/#.*//' -e '/^[[:space:]]*$/d' -e '/localhost/d' -e '/_/d' -e '/[\r\n]/d' | cut -d" " -f2 )
# add personal blacklist
blhost="nothing"
sed '/^ *#/d;s/#.*//' $blacklisted | while read blhost; do
if ! grep -q $blhost $target-new ; then
echo "zone \"$blhost\" IN { type master; notify no; file \"null.zone.file\"; };" >> $target-new
fi
done
# remove whitelisted domains. ($wlisted variable have to be defined, otherwise sed might remove everything)
wlisted="nothingatall"
sed '/^ *#/d;s/#.*//' $whitelisted | while read wlisted; do
sed -i /"$wlisted"'/d' $target-new done
#remove duplicates, named is intolerant to multiple definitions for the same host
cat $target-new | sort -u > $target
#cleanup line containing "empty" domain
sed -i '/\"\"/d' $target
# cleanup the last remanents of bad lines reported by named-checkconf
if [ ! $(/usr/sbin/named-checkconf -t /var/lib/named -z /etc/named.conf >/dev/null 2>&1; echo $?) = 0 ]; then
badlines=$(/usr/sbin/named-checkconf -t /var/lib/named -z /etc/named.conf | cut -d: -f2 | sed -e 's/$/d;/' | tr -d '\n')
sed -i "$badlines" $target
fi
rm -f $target-new
# reload bind
/bin/systemctl reload named.service