bind_reverse_generator

#!/bin/ksh
##Potaje6
##Script used in a much simpler way in my old times working in the barcelona public transport project generating the zones for each environment
##now expanded with some features to adapt it to more situations
##This generates reverse zones very raw, check everything before putting it to production or restarting bind, headings and configs might need some tweaks, the records part can be ignored, never gave me any problem
##Feel free to add some constraints to dont process CNAMEs more effectively



SERIAL=$(echo $(date  +%Y%m%d)01)
#DOMAIN=$1
MASTERS=dns
OCTET=3
DOMAIN=area51.gov
EXEC_DIR=$(dirname $0)
EXEC_NAME=$(basename $0)
EXEC_FULL=${EXEC_DIR}/${EXEC_NAME}
EXEC_TEMP_DIR=${EXEC_DIR}/${EXEC_NAME}.dir
TEMPFILE=${EXEC_FULL}.tmp
#TEMPFILE2=${EXEC_FULL}.tmp2

clean(){
        rm -f $EXEC_TEMP_DIR/*
        rmdir $EXEC_TEMP_DIR
}

print_uso(){
cat <<EOF
Script to generate reverse zones from bind direct zones
Usage:
./bind_reverse_generator [-d domain ] [-m masters] [-o octets] file
-d domain. Default: $DOMAIN
-m name of the master servers, for example, localdns would be printed as localdns1 and localdns2 in the authoritative servers. Default $MASTERS
-o the number of octets that you want to be cutted, 3 = splitted in zones with just the last octet in each. Default $OCTET
--help show this message
EOF
exit
}



gen_heading(){
cat <<EOF
;/var/named/db.$1.in-addr.arpa.zone
;\$TTL 14400
\$TTL 300
@      IN      SOA      ${MASTERS}1.${DOMAIN}. ${MASTERS}2.${DOMAIN}. (
                        $SERIAL
                        300
                        7200
                        1209600
                        86400 )
;

EOF
}

if [ $# -eq 0 ]; then
        print_uso
fi

while [ $# -gt 1 ];
do
        case $1 in
        "-d") DOMAIN=$2
        shift
        shift
;;
        "-m") MASTERS=$2
		shift
        shift
;;
        "-o") OCTET=$2
                shift
                shift
;;
        "--help") print_uso
;;
        *)
        shift
esac
done

if [ "$1" == "-h" ] || [ "$1" == "--help" ];then
        print_uso
fi


if [ "$OCTET" -gt 3 ] || [ "$OCTET" -lt 1 ]; then
        echo "Invalid octet selection, must be between 1 and 3"
        print_uso
fi


##Spaghuetti code because fuck optimization and absurd complex stuff
octet1(){
FIELDS=1
}
generator1(){
awk -v DOM="$DOMAIN"  {'print $(NF-2)"."$(NF-1)"."$NF"\tIN\tPTR\t"$1"."DOM"."'}
}
reverse1(){
awk -F "." {'print $1'}
}

octet2(){
FIELDS=1,2
}
generator2(){
awk -v DOM="$DOMAIN"  {'print $(NF-1)"."$NF"\tIN\tPTR\t"$1"."DOM"."'}
}
reverse2(){
awk -F "." {'print $2"."$1'}
}

octet3(){
FIELDS=1,2,3
}
generator3(){
awk -v DOM="$DOMAIN"  {'print $NF"\tIN\tPTR\t"$1"."DOM"."'}
}
reverse3(){
awk -F "." {'print $3"."$2"."$1'}
}

octet$OCTET


ZONE_FILE=$1

test -f $ZONE_FILE || (echo "$ZONE_FILE doesn't exist, exiting..."; exit)


##And this my friends, is what i call a autentica puta mierda, but it works
#If zones dont have the format "$HOST IN A $IP" "grep -f 4" should be changed to 3 
cat $ZONE_FILE \
| grep -v ^\; \
| tr -s "\t" " " \
| cut -f 4 -d " " \
| grep ^[0-9] \
| grep \\. \
| cut -f $FIELDS -d . \
| sort -u \
| while read range ; do REVERSED_RANGE=$(echo $range | cut -f $FIELDS -d . | reverse$OCTET);

gen_heading $range \
| tee ${REVERSED_RANGE}.in-addr.arpa.zone.db;  grep $range $ZONE_FILE \
| sed 's/\./ /g' > $TEMPFILE; cat $TEMPFILE \
| generator${OCTET} \
| grep -v ^\; \
| tee -a ${REVERSED_RANGE}.in-addr.arpa.zone.db;  done

##Lazyness protocol ENGAGED
#If zones dont have the format "$HOST IN A $IP" "grep -f 4" should be changed to 3 
echo
echo "##this is a sample of what would look like the config for the zones generated in your master, tweak it to your environment"
echo
cat $ZONE_FILE \
| grep -v ^\; \
| tr -s "\t" " " \
| cut -f 4 -d " " \
| grep ^[0-9] \
| grep \\. \
| cut -f $FIELDS -d . \
| sort -u \
| reverse$OCTET \
| while read range; do

cat <<EOF
zone "$range.in-addr.arpa" in {
type master;
file "$range.in-addr.arpa.zone.db";
};
EOF
done

test -f $TEMPFILE && rm $TEMPFILE