Update for Firehol's get-iana.sh script

I didn't notice very quickly but it was brought to my attention through the mailing list for firehol that the IANA Reserved IPs list formatting was updated. So I went through and did a little update to get it working again. This isn't 100% tested so use at your own risk.

#!/bin/bash

# $Id: get-iana.sh,v 1.11 2008/05/02 23:38:31 bdewong Exp $
#
# $Log: get-iana.sh,v $
#
# Revision 1.11 2008/05/02 23:38:31 bdewong
# Updated parsing of ipv4-address-space
#
# Revision 1.10  2007/05/05 23:38:31  ktsaou
# Added support for external definitions of:
#
# RESERVED_IPS
# PRIVATE_IPS
# MULTICAST_IPS
# UNROUTABLE_IPS
#
# in files under the same name in /etc/firehol/.
# Only RESERVED_IPS is mandatory (firehol will complain if it is not there,
# but it will still work without it), and is also the only file that firehol
# checks how old is it. If it is 90+ days old, firehol will complain again.
#
# Changed the supplied get-iana.sh script to generate the RESERVED_IPS file.
# FireHOL also instructs the user to use this script if the file is missing
# or is too old.
#
# Revision 1.9  2007/04/29 19:34:11  ktsaou
# *** empty log message ***
#
# Revision 1.8  2005/06/02 15:48:52  ktsaou
# Allowed 127.0.0.1 to be in RESERVED_IPS
#
# Revision 1.7  2005/05/08 23:27:23  ktsaou
# Updated RESERVED_IPS to current IANA reservations.
#
# Revision 1.6  2004/01/10 18:44:39  ktsaou
# Further optimized and reduced PRIVATE_IPS using:
# http://www.vergenet.net/linux/aggregate/
#
# The supplied get-iana.sh uses 'aggregate-flim' if it finds it in the path.
# (aggregate-flim is the name of this program when installed on Gentoo)
#
# Revision 1.5  2003/08/23 23:26:50  ktsaou
# Bug #793889:
# Change #!/bin/sh to #!/bin/bash to allow FireHOL run on systems that
# bash is not linked to /bin/sh.
#
# Revision 1.4  2002/10/27 12:44:42  ktsaou
# CVS test
#

#
# Program that downloads the IPv4 address space allocation by IANA
# and creates a list with all reserved address spaces.
#

IPV4_ADDRESS_SPACE_URL="http://www.iana.org/assignments/ipv4-address-space"
IANA_RESERVED="IANA\|Future use"

tempfile="/tmp/iana.$$.$RANDOM"

AGGREGATE="`which aggregate-flim 2>/dev/null`"
if [ -z "${AGGREGATE}" ]
then
       echo >&2
       echo >&2
       echo >&2 "WARNING"
       echo >&2 "Please install 'aggregate-flim' to shrink the list of IPs."
       echo >&2
       echo >&2
fi

echo >&2
echo >&2 "Fetching IANA IPv4 Address Space, from:"
echo >&2 "${IPV4_ADDRESS_SPACE_URL}"
echo >&2

wget -O - --proxy=off "${IPV4_ADDRESS_SPACE_URL}"       |\
       grep -e "${IANA_RESERVED}"                      |\
       cut -d ' ' -f 1                                 |\
(
       last=-1
       while IFS="/" read range net
       do
               range=`expr $range + 0`
               net=`expr $net + 0`

               if [ ! $net -eq 8 ]
               then
                       echo >&2 "Cannot handle network masks of $net bits ($range/$net)"
                       continue
               fi
               
               if [ $range -gt $last ]
               then
                       echo "$range.0.0.0/$net"
                       last=$range
               fi
       done
) | \
(
       if [ ! -z "${AGGREGATE}" -a -x "${AGGREGATE}" ]
       then
               "${AGGREGATE}"
       else
               cat
       fi
) >"${tempfile}"

echo >&2
echo >&2
echo >&2 "FOUND THE FOLLOWING RESERVED IP RANGES:"
printf "RESERVED_IPS=\""
i=0
for x in `cat ${tempfile}`
do
       i=$[i + 1]
       printf "${x} "
done
printf "\"\n"

if [ $i -eq 0 ]
then
       echo >&2
       echo >&2
       echo >&2 "Failed to find reserved IPs."
       echo >&2 "Possibly the file format has been changed, or I cannot fetch the URL."
       echo >&2

       rm -f ${tempfile}
       exit 1
fi
echo >&2
echo >&2
echo >&2 "Differences between the fetched list and the list installed in"
echo >&2 "/etc/firehol/RESERVED_IPS:"

echo >&2 "# diff /etc/firehol/RESERVED_IPS ${tempfile}"
diff /etc/firehol/RESERVED_IPS ${tempfile}

if [ $? -eq 0 ]
then
       echo >&2
       echo >&2 "No differences found."
       echo >&2

       rm -f ${tempfile}
       exit 0
fi

echo >&2
echo >&2
echo >&2 "Would you like to save this list to /etc/firehol/RESERVED_IPS"
echo >&2 "so that FireHOL will automatically use it from now on?"
echo >&2
while [ 1 = 1 ]
do
       printf >&2 "yes or no > "
       read x

       case "${x}" in
               yes)    cp -f /etc/firehol/RESERVED_IPS /etc/firehol/RESERVED_IPS.old 2>/dev/null
                       cat "${tempfile}" >/etc/firehol/RESERVED_IPS || exit 1
                       echo >&2 "New RESERVED_IPS written to '/etc/firehol/RESERVED_IPS'."
                       break
                       ;;

               no)
                       echo >&2 "Saved nothing."
                       break
                       ;;

               *)      echo >&2 "Cannot understand '${x}'."
                       ;;
       esac
done

rm -f ${tempfile}