#!/bin/bash

#

# ipset      Start and stop ipset firewall sets

#

# config: /etc/ipset/ipset

#

IPSET=ipset

IPSET_BIN=/usr/sbin/${IPSET}

IPSET_DATA=/etc/${IPSET}/${IPSET}

IPTABLES_CONFIG=/etc/sysconfig/iptables-config

IP6TABLES_CONFIG=${IPTABLES_CONFIG/iptables/ip6tables}

TMP_FIFO=/tmp/${IPSET}.$$

if [[ ! -x ${IPSET_BIN} ]]; then

	echo "${IPSET_BIN} does not exist."

	exit 5

fi

CLEAN_FILES=TMP_FIFO

trap "rm -f \$CLEAN_FILES" EXIT

# Default ipset configuration:

[[ -z $IPSET_SAVE_ON_STOP ]] && IPSET_SAVE_ON_STOP=no		# Overridden by ip(6)tables IP(6)TABLES_SAVE_ON_STOP

[[ -z $IPSET_SAVE_ON_RESTART ]] && IPSET_SAVE_ON_RESTART=no	# Overridden by ip(6)tables IP(6)TABLES_SAVE_ON_RESTART

# Load iptables configuration(s)

[[ -f "$IPTABLES_CONFIG" ]] && . "$IPTABLES_CONFIG"

[[ -f "$IP6TABLES_CONFIG" ]] && . "$IP6TABLES_CONFIG"

# It doesn't make sense to save iptables config and not our config

[[ ${IPTABLES_SAVE_ON_STOP} = yes || ${IP6TABLES_SAVE_ON_STOP} = yes ]] && IPSET_SAVE_ON_STOP=yes

[[ ${IPTABLES_SAVE_ON_RESTART} = yes || ${IP6TABLES_SAVE_ON_RESTART} = yes ]] && IPSET_SAVE_ON_RESTART=yes

check_can_unload() {

    # If the xt_set module is loaded and can't be unloaded, then iptables is

    # using ipsets, so refuse to stop the service.

    if [[ -n $(lsmod | grep "^xt_set ") ]]; then

	rmmod xt_set 2>/dev/null

	[[ $? -ne 0 ]] && echo Current iptables configuration requires ipsets && return 1

    fi

    return 0

}

flush_n_delete() {

    local ret=0 set

    # Flush sets

    ${IPSET_BIN} flush

    let ret+=$?

    # Delete ipset sets. If we don't do them individually, then none

    # will be deleted unless they all can be.

    for set in $(${IPSET_BIN} list -name); do

	    ${IPSET_BIN} destroy 2>/dev/null

	    [[ $? -ne 0 ]] && ret=1

    done

    return $ret

}

start_clean()

{

    mkfifo -m go= "${TMP_FIFO}"

    [[ $? -ne 0 ]] && return 1

    # Get the lists of sets in current(old) config and new config

    old_sets="$(${IPSET_BIN} list -name | sort -u)"

    new_sets="$(grep ^create "${IPSET_DATA}" | cut -d " " -f 2 | sort -u)"

    # List of sets no longer wanted

    drop_sets="$( printf "%s\n" "${old_sets}" > "${TMP_FIFO}"  &

		  printf "%s\n" "${new_sets}" | comm -23 "${TMP_FIFO}" -

		)"

    # Get rid of sets no longer needed

    # Unfortunately -! doesn't work for destroy, so we have to do it a command at a time

    for dset in $drop_sets; do

	ipset destroy $dset 2>/dev/null

	# If it won't go - ? in use by iptables, just clear it

	[[ $? -ne 0 ]] && ipset flush $dset

    done

    # Now delete the set members no longer required

    ${IPSET_BIN} save | grep "^add " | sort >${TMP_FIFO} &

      grep "^add " ${IPSET_DATA} | sort | comm -23 ${TMP_FIFO} - | sed -e "s/^add /del /" \

      | ${IPSET_BIN} restore -!

    # At last we can add the set members we haven't got

    ipset restore -! <${IPSET_DATA}

    rm ${TMP_FIFO}

    return 0

}

start() {

    # Do not start if there is no config file.

    [[ ! -f "$IPSET_DATA" ]] && echo "Loaded with no configuration" && return 0

    # We can skip the first bit and do a simple load if

    # there is no current ipset configuration

    res=1

    if [[ -n $(${IPSET_BIN} list -name) ]]; then

	# The following may fail for some bizarre reason

	start_clean

	res=$?

	[[ $res -ne 0 ]] && echo "Some old configuration may remain"

    fi

    # res -ne 0 => either start_clean failed, or we didn't need to run it

    if [[ $res -ne 0 ]]; then

	# This is the easy way to start but would leave any old

	# entries still configured. Still, better than nothing -

	# but fine if we had no config

	${IPSET_BIN} restore -! <${IPSET_DATA}

	res=$?

    fi

    if [[ $res -ne 0 ]]; then

	return 1

    fi

    return 0

}

stop() {

    # Nothing to stop if ip_set module is not loaded.

    lsmod | grep -q "^ip_set "

    [[ $? -ne 0 ]] && return 6

    flush_n_delete

    [[ $? -ne 0 ]] && echo Warning: Not all sets were flushed/deleted

    return 0

}

save() {

    # Do not save if ip_set module is not loaded.

    lsmod | grep -q "^ip_set "

    [[ $? -ne 0 ]] && return 6

    [[ -z $(${IPSET_BIN} list -name) ]] && return 0

    ret=0

    TMP_FILE=$(/bin/mktemp -q /tmp/$IPSET.XXXXXX) \

	&& CLEAN_FILES+=" $TMP_FILE" \

	&& chmod 600 "$TMP_FILE" \

	&& ${IPSET_BIN} save > $TMP_FILE 2>/dev/null \

	&& [[ -s $TMP_FILE ]] \

	|| ret=1

    if [[ $ret -eq 0 ]]; then

	# No need to do anything if the files are the same

	if [[ ! -f $IPSET_DATA ]]; then

	    mv $TMP_FILE $IPSET_DATA && chmod 600 $IPSET_DATA || ret=1

	else

	    diff -q $TMP_FILE $IPSET_DATA >/dev/null

	    if [[ $? -ne 0 ]]; then

		if [[ -f $IPSET_DATA ]]; then

		    cp -f --preserve=timestamps $IPSET_DATA $IPSET_DATA.save \

			&& chmod 600 $IPSET_DATA.save \

			|| ret=1

		fi

		if [[ $ret -eq 0 ]]; then

		    cp -f --preserve=timestamps $TMP_FILE $IPSET_DATA \

			&& chmod 600 $IPSET_DATA \

			|| ret=1

		fi

	    fi

	fi

    fi

    rm -f $TMP_FILE

    return $ret

}

case "$1" in

    start)

	start

	RETVAL=$?

	;;

    stop)

	check_can_unload || exit 1

	[[ $IPSET_SAVE_ON_STOP = yes ]] && save

	stop

	RETVAL=$?

	[[ $RETVAL -eq 6 ]] && echo "${IPSET}: not running" && exit 0

	;;

    reload)

	[[ $IPSET_SAVE_ON_RESTART = yes ]] && save

	stop

	RETVAL=$?

	[[ $RETVAL -eq 6 ]] && echo "${IPSET}: not running" && exit 0

	start

	RETVAL=$?

	;;

    *)

	echo "Usage: $IPSET {start|stop|reload}" >&2

	exit 1

esac

exit $RETVAL