#!/bin/sh
#
# ip6tables	Start ip6tables firewall
#
# chkconfig: 2345 08 92
# description:	Starts, stops and saves ip6tables firewall
#
# config: /etc/sysconfig/ip6tables
# config: /etc/sysconfig/ip6tables-config

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

IP6TABLES=ip6tables
IP6TABLES_DATA=/etc/sysconfig/$IP6TABLES
IP6TABLES_CONFIG=/etc/sysconfig/${IP6TABLES}-config
IPV=${IP6TABLES%tables} # ip for ipv4 | ip6 for ipv6
PROC_IP6TABLES_NAMES=/proc/net/${IPV}_tables_names
VAR_SUBSYS_IP6TABLES=/var/lock/subsys/$IP6TABLES

if [ ! -x /sbin/$IP6TABLES ]; then
    echo -n $"/sbin/$IP6TABLES does not exist."; warning; echo
    exit 0
fi

if lsmod 2>/dev/null | grep -q ipchains ; then
    echo -n $"ipchains and $IP6TABLES can not be used together."; warning; echo
    exit 1
fi

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

# Default firewall configuration:
IP6TABLES_MODULES=""
IP6TABLES_MODULES_UNLOAD="yes"
IP6TABLES_SAVE_ON_STOP="no"
IP6TABLES_SAVE_ON_RESTART="no"
IP6TABLES_SAVE_COUNTER="no"
IP6TABLES_STATUS_NUMERIC="yes"

# Load firewall configuration.
[ -f "$IP6TABLES_CONFIG" ] && . "$IP6TABLES_CONFIG"

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 $mod > /dev/null 2>&1
	let ret+=$?;
    fi

    return $ret
}

flush_n_delete() {
    # Flush firewall rules and delete chains.
    [ -e "$PROC_IP6TABLES_NAMES" ] || return 1

    # Check if firewall is configured (has tables)
    tables=`cat $PROC_IP6TABLES_NAMES 2>/dev/null`
    [ -z "$tables" ] && return 1

    echo -n $"Flushing firewall rules: "
    ret=0
    # For all tables
    for i in $tables; do
        # Flush firewall rules.
	$IP6TABLES -t $i -F;
	let ret+=$?;

        # Delete firewall chains.
	$IP6TABLES -t $i -X;
	let ret+=$?;

	# Set counter to zero.
	$IP6TABLES -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_IP6TABLES_NAMES" ] && return 1

    # Check if firewall is configured (has tables)
    tables=`cat $PROC_IP6TABLES_NAMES 2>/dev/null`
    [ -z "$tables" ] && return 1

    echo -n $"Setting chains to policy $policy: "
    ret=0
    for i in $tables; do
	echo -n "$i "
	case "$i" in
	    raw)
		$IP6TABLES -t raw -P PREROUTING $policy \
		    && $IP6TABLES -t raw -P OUTPUT $policy \
		    || let ret+=1
		;;
	    filter)
                $IP6TABLES -t filter -P INPUT $policy \
		    && $IP6TABLES -t filter -P OUTPUT $policy \
		    && $IP6TABLES -t filter -P FORWARD $policy \
		    || let ret+=1
		;;
	    nat)
		$IP6TABLES -t nat -P PREROUTING $policy \
		    && $IP6TABLES -t nat -P POSTROUTING $policy \
		    && $IP6TABLES -t nat -P OUTPUT $policy \
		    || let ret+=1
		;;
	    mangle)
	        $IP6TABLES -t mangle -P PREROUTING $policy \
		    && $IP6TABLES -t mangle -P POSTROUTING $policy \
		    && $IP6TABLES -t mangle -P INPUT $policy \
		    && $IP6TABLES -t mangle -P OUTPUT $policy \
		    && $IP6TABLES -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 "$IP6TABLES_DATA" ] || return 1

    echo -n $"Applying $IP6TABLES firewall rules: "

    OPT=
    [ "x$IP6TABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"

    $IP6TABLES-restore $OPT $IP6TABLES_DATA
    if [ $? -eq 0 ]; then
	success; echo
    else
	failure; echo; return 1
    fi
    
    # Load additional modules (helpers)
    if [ -n "$IP6TABLES_MODULES" ]; then
	echo -n $"Loading additional $IP6TABLES modules: "
	ret=0
	for mod in $IP6TABLES_MODULES; do
	    echo -n "$mod "
	    modprobe $mod > /dev/null 2>&1
	    let ret+=$?;
	done
	[ $ret -eq 0 ] && success || failure
	echo
    fi
    
    touch $VAR_SUBSYS_IP6TABLES
    return $ret
}

stop() {
    # Do not stop if ip6tables module is not loaded.
    [ -e "$PROC_IP6TABLES_NAMES" ] || return 1

    flush_n_delete
    set_policy ACCEPT
    
    if [ "x$IP6TABLES_MODULES_UNLOAD" = "xyes" ]; then
	echo -n $"Unloading $IP6TABLES modules: "
	ret=0
	rmmod_r ${IPV}_tables
	let ret+=$?;
	rmmod_r ${IPV}_conntrack
	let ret+=$?;
	[ $ret -eq 0 ] && success || failure
	echo
    fi
    
    rm -f $VAR_SUBSYS_IP6TABLES
    return $ret
}

save() {
    # Check if iptable module is loaded
    [ ! -e "$PROC_IP6TABLES_NAMES" ] && return 1

    # Check if firewall is configured (has tables)
    tables=`cat $PROC_IP6TABLES_NAMES 2>/dev/null`
    [ -z "$tables" ] && return 1

    echo -n $"Saving firewall rules to $IP6TABLES_DATA: "

    OPT=
    [ "x$IP6TABLES_SAVE_COUNTER" = "xyes" ] && OPT="-c"

    ret=0
    TMP_FILE=`/bin/mktemp -q /tmp/$IP6TABLES.XXXXXX` \
	&& chmod 600 "$TMP_FILE" \
	&& $IP6TABLES-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 $IP6TABLES_DATA ]; then
	    cp -f $IP6TABLES_DATA $IP6TABLES_DATA.save \
		&& chmod 600 $IP6TABLES_DATA.save \
		|| ret=1
	fi
	if [ $ret -eq 0 ]; then
	    cp -f $TMP_FILE $IP6TABLES_DATA \
		&& chmod 600 $IP6TABLES_DATA \
	        || ret=1
	fi
    fi
    [ $ret -eq 0 ] && success || failure
    echo
    rm -f $TMP_FILE
    return $ret
}

status() {
    tables=`cat $PROC_IP6TABLES_NAMES 2>/dev/null`

    # Do not print status if lockfile is missing and ip6tables modules are not 
    # loaded.
    # Check if iptable module is loaded
    if [ ! -f "$VAR_SUBSYS_IP6TABLES" -a -z "$tables" ]; then
	echo $"Firewall is stopped."
	return 1
    fi

    # Check if firewall is configured (has tables)
    if [ ! -e "$PROC_IP6TABLES_NAMES" ]; then
	echo $"Firewall is not configured. "
	return 1
    fi
    if [ -z "$tables" ]; then
	echo $"Firewall is not configured. "
	return 1
    fi

    NUM=
    [ "x$IP6TABLES_STATUS_NUMERIC" = "xyes" ] && NUM="-n"
    VERBOSE= 
    [ "x$IP6TABLES_STATUS_VERBOSE" = "xyes" ] && VERBOSE="--verbose"
    COUNT=
    [ "x$IP6TABLES_STATUS_LINENUMBERS" = "xyes" ] && COUNT="--line-numbers"

    for table in $tables; do
	echo $"Table: $table"
	$IP6TABLES -t $table --list $NUM $VERBOSE $COUNT && echo
    done

    return 0
}

restart() {
    [ "x$IP6TABLES_SAVE_ON_RESTART" = "xyes" ] && save
    stop
    start
}

case "$1" in
    start)
	stop
	start
	RETVAL=$?
	;;
    stop)
	[ "x$IP6TABLES_SAVE_ON_STOP" = "xyes" ] && save
	stop
	RETVAL=$?
	;;
    restart)
	restart
	RETVAL=$?
	;;
    condrestart)
	[ -e "$VAR_SUBSYS_IP6TABLES" ] && restart
	;;
    status)
	status
	RETVAL=$?
	;;
    panic)
	flush_n_delete
	set_policy DROP
	RETVAL=$?
        ;;
    save)
	save
	RETVAL=$?
	;;
    *)
	echo $"Usage: $0 {start|stop|restart|condrestart|status|panic|save}"
	exit 1
	;;
esac

exit $RETVAL