iptables/iptables.init

#!/bin/bash
#
# iptables	Start iptables firewall
#
# chkconfig: 2345 08 92
# description:	Starts, stops and saves iptables firewall
#
# config: /etc/sysconfig/iptables
# config: /etc/sysconfig/iptables-config
#
### BEGIN INIT INFO
# Provides: iptables
# Required-Start:
# Required-Stop:
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: start and stop iptables firewall
# Description: Start, stop and save iptables firewall
### END INIT INFO

# Source function library.
. /etc/init.d/functions

IPTABLES=iptables
IPTABLES_DATA=/etc/sysconfig/$IPTABLES
IPTABLES_CONFIG=/etc/sysconfig/${IPTABLES}-config
IPV=${IPTABLES%tables} # ip for ipv4 | ip6 for ipv6
[ "$IPV" = "ip" ] && _IPV="ipv4" || _IPV="ipv6"
PROC_IPTABLES_NAMES=/proc/net/${IPV}_tables_names
VAR_SUBSYS_IPTABLES=/var/lock/subsys/$IPTABLES

if [ ! -x /sbin/$IPTABLES ]; then
    echo -n $"${IPTABLES}: /sbin/$IPTABLES does not exist."; warning; echo
    exit 5
fi

# Old or new modutils
/sbin/modprobe --version 2>&1 | grep -q module-init-tools \
    && NEW_MODUTILS=1 \
    || NEW_MODUTILS=0

# Default firewall configuration:
IPTABLES_MODULES=""
IPTABLES_MODULES_UNLOAD="yes"
IPTABLES_SAVE_ON_STOP="no"
IPTABLES_SAVE_ON_RESTART="no"
IPTABLES_SAVE_COUNTER="no"
IPTABLES_STATUS_NUMERIC="yes"
IPTABLES_STATUS_VERBOSE="no"
IPTABLES_STATUS_LINENUMBERS="yes"

# Load firewall configuration.
[ -f "$IPTABLES_CONFIG" ] && . "$IPTABLES_CONFIG"

# Netfilter modules
NF_MODULES=($(lsmod | awk "/^${IPV}table_/ {print \$1}") ${IPV}_tables)
NF_MODULES_COMMON=(x_tables nf_nat nf_conntrack) # Used by netfilter v4 and v6

# Get active tables
NF_TABLES=$(cat "$PROC_IPTABLES_NAMES" 2>/dev/null)


rmmod_r() {
    # Unload module with all referring modules.
    # At first all referring modules will be unloaded, then the module itself.
    local mod=$1
    local ret=0
    local ref=

    # Get referring modules.
    # New modutils have another output format.
    [ $NEW_MODUTILS = 1 ] \
	&& ref=$(lsmod | awk "/^${mod}/ { print \$4; }" | tr ',' ' ') \
	|| ref=$(lsmod | grep ^${mod} | cut -d "[" -s -f 2 | cut -d "]" -s -f 1)

    # recursive call for all referring modules
    for i in $ref; do
	rmmod_r $i
	let ret+=$?;
    done

    # Unload module.
    # The extra test is for 2.6: The module might have autocleaned,
    # after all referring modules are unloaded.
    if grep -q "^${mod}" /proc/modules ; then
	modprobe -r $mod > /dev/null 2>&1
	res=$?
	[ $res -eq 0 ] || echo -n " $mod"
	let ret+=$res;
    fi

    return $ret
}

flush_n_delete() {
    # Flush firewall rules and delete chains.
    [ ! -e "$PROC_IPTABLES_NAMES" ] && return 0

    # Check if firewall is configured (has tables)
    [ -z "$NF_TABLES" ] && return 1

    echo -n $"${IPTABLES}: Flushing firewall rules: "
    ret=0
    # For all tables
    for i in $NF_TABLES; do
        # Flush firewall rules.
	$IPTABLES -t $i -F;
	let ret+=$?;

        # Delete firewall chains.
	$IPTABLES -t $i -X;
	let ret+=$?;

	# Set counter to zero.
	$IPTABLES -t $i -Z;
	let ret+=$?;
    done

    [ $ret -eq 0 ] && success || failure
    echo
    return $ret
}

set_policy() {
    # Set policy for configured tables.
    policy=$1

    # Check if iptable module is loaded
    [ ! -e "$PROC_IPTABLES_NAMES" ] && return 0

    # Check if firewall is configured (has tables)
    tables=$(cat "$PROC_IPTABLES_NAMES" 2>/dev/null)
    [ -z "$tables" ] && return 1

    echo -n $"${IPTABLES}: Setting chains to policy $policy: "
    ret=0
    for i in $tables; do
	echo -n "$i "
	case "$i" in
	    raw)
		$IPTABLES -t raw -P PREROUTING $policy \
		    && $IPTABLES -t raw -P OUTPUT $policy \
		    || let ret+=1
		;;
	    filter)
                $IPTABLES -t filter -P INPUT $policy \
		    && $IPTABLES -t filter -P OUTPUT $policy \
		    && $IPTABLES -t filter -P FORWARD $policy \
		    || let ret+=1
		;;
	    nat)
		$IPTABLES -t nat -P PREROUTING $policy \
		    && $IPTABLES -t nat -P POSTROUTING $policy \
		    && $IPTABLES -t nat -P OUTPUT $policy \
		    || let ret+=1
		;;
	    mangle)
	        $IPTABLES -t mangle -P PREROUTING $policy \
		    && $IPTABLES -t mangle -P POSTROUTING $policy \
		    && $IPTABLES -t mangle -P INPUT $policy \
		    && $IPTABLES -t mangle -P OUTPUT $policy \
		    && $IPTABLES -t mangle -P FORWARD $policy \
		    || let ret+=1
		;;
	    *)
	        let ret+=1
		;;
        esac
    done

    [ $ret -eq 0 ] && success || failure
    echo
    return $ret
}

start() {
    # Do not start if there is no config file.
    [ ! -f "$IPTABLES_DATA" ] && return 6

    # check if ipv6 module load is deactivated
    if [ "${_IPV}" = "ipv6" ] \
	&& grep -qIsE "^install[[:space:]]+${_IPV}[[:space:]]+/bin/(true|false)" /etc/modprobe.conf /etc/modprobe.d/* ; then
	echo $"${IPTABLES}: ${_IPV} is disabled."
	return 150
    fi

    echo -n $"${IPTABLES}: Applying firewall rules: "

    OPT=
    [ "x$IPTABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"

    $IPTABLES-restore $OPT $IPTABLES_DATA
    if [ $? -eq 0 ]; then
	success; echo
    else
	failure; echo; return 1
    fi
    
    # Load additional modules (helpers)
    if [ -n "$IPTABLES_MODULES" ]; then
	echo -n $"${IPTABLES}: Loading additional modules: "
	ret=0
	for mod in $IPTABLES_MODULES; do
	    echo -n "$mod "
	    modprobe $mod > /dev/null 2>&1
	    let ret+=$?;
	done
	[ $ret -eq 0 ] && success || failure
	echo
    fi
    
    touch $VAR_SUBSYS_IPTABLES
    return $ret
}

stop() {
    # Do not stop if iptables module is not loaded.
    [ ! -e "$PROC_IPTABLES_NAMES" ] && return 0

    # Set default chain policy to ACCEPT, in order to not break shutdown
    # on systems where the default policy is DROP and root device is
    # network-based (i.e.: iSCSI, NFS)
    set_policy ACCEPT
    
    # And then, flush the rules and delete chains
    flush_n_delete

    if [ "x$IPTABLES_MODULES_UNLOAD" = "xyes" ]; then
	echo -n $"${IPTABLES}: Unloading modules: "
	ret=0
	for mod in ${NF_MODULES[*]}; do
	    rmmod_r $mod
	    let ret+=$?;
	done
	# try to unload remaining netfilter modules used by ipv4 and ipv6 
	# netfilter
	for mod in ${NF_MODULES_COMMON[*]}; do
	    rmmod_r $mod >/dev/null
	done
	[ $ret -eq 0 ] && success || failure
	echo
    fi
    
    rm -f $VAR_SUBSYS_IPTABLES
    return $ret
}

save() {
    # Check if iptable module is loaded
    [ ! -e "$PROC_IPTABLES_NAMES" ] && return 0

    # Check if firewall is configured (has tables)
    [ -z "$NF_TABLES" ] && return 6

    echo -n $"${IPTABLES}: Saving firewall rules to $IPTABLES_DATA: "

    OPT=
    [ "x$IPTABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"

    ret=0
    TMP_FILE=$(/bin/mktemp -q /tmp/$IPTABLES.XXXXXX) \
	&& chmod 600 "$TMP_FILE" \
	&& $IPTABLES-save $OPT > $TMP_FILE 2>/dev/null \
	&& size=$(stat -c '%s' $TMP_FILE) && [ $size -gt 0 ] \
	|| ret=1
    if [ $ret -eq 0 ]; then
	if [ -e $IPTABLES_DATA ]; then
	    cp -f $IPTABLES_DATA $IPTABLES_DATA.save \
		&& chmod 600 $IPTABLES_DATA.save \
		|| ret=1
	fi
	if [ $ret -eq 0 ]; then
	    cp -f $TMP_FILE $IPTABLES_DATA \
		&& chmod 600 $IPTABLES_DATA \
	        || ret=1
	fi
    fi
    [ $ret -eq 0 ] && success || failure
    echo
    rm -f $TMP_FILE
    return $ret
}

status() {
    if [ ! -f "$VAR_SUBSYS_IPTABLES" -a -z "$NF_TABLES" ]; then
	echo $"${IPTABLES}: Firewall is not running."
	return 3
    fi

    # Do not print status if lockfile is missing and iptables modules are not 
    # loaded.
    # Check if iptable modules are loaded
    if [ ! -e "$PROC_IPTABLES_NAMES" ]; then
	echo $"${IPTABLES}: Firewall modules are not loaded."
	return 3
    fi

    # Check if firewall is configured (has tables)
    if [ -z "$NF_TABLES" ]; then
	echo $"${IPTABLES}: Firewall is not configured. "
	return 3
    fi

    NUM=
    [ "x$IPTABLES_STATUS_NUMERIC" = "xyes" ] && NUM="-n"
    VERBOSE= 
    [ "x$IPTABLES_STATUS_VERBOSE" = "xyes" ] && VERBOSE="--verbose"
    COUNT=
    [ "x$IPTABLES_STATUS_LINENUMBERS" = "xyes" ] && COUNT="--line-numbers"

    for table in $NF_TABLES; do
	echo $"Table: $table"
	$IPTABLES -t $table --list $NUM $VERBOSE $COUNT && echo
    done

    return 0
}

restart() {
    [ "x$IPTABLES_SAVE_ON_RESTART" = "xyes" ] && save
    stop
    start
}


case "$1" in
    start)
	[ -f "$VAR_SUBSYS_IPTABLES" ] && exit 0
	start
	RETVAL=$?
	;;
    stop)
	[ "x$IPTABLES_SAVE_ON_STOP" = "xyes" ] && save
	stop
	RETVAL=$?
	;;
    restart|force-reload)
	restart
	RETVAL=$?
	;;
    condrestart|try-restart)
	[ ! -e "$VAR_SUBSYS_IPTABLES" ] && exit 0
	restart
	RETVAL=$?
	;;
    status)
	status
	RETVAL=$?
	;;
    panic)
	flush_n_delete
	set_policy DROP
	RETVAL=$?
        ;;
    save)
	save
	RETVAL=$?
	;;
    *)
	echo $"Usage: ${IPTABLES} {start|stop|restart|condrestart|status|panic|save}"
	RETVAL=2
	;;
esac

exit $RETVAL