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

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

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

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

if lsmod 2>/dev/null | grep -q ipchains ; then
    echo -n $"ipchains and $IPTABLES can not be used together."; warning; echo
    exit 0
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="no"

# Load firewall configuration.
[ -f "$IPTABLES_CONFIG" ] && . "$IPTABLES_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_IPTABLES_NAMES" ] || return 1

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

    echo -n $"Flushing firewall rules: "
    ret=0
    # For all tables
    for i in $tables; do
        # Flush firewall rules.
	$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 1

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

    echo -n $"Setting chains to policy $policy: "
    ret=0
    for i in $tables; do
	echo -n "$i "
	case "$i" in
	    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 1

    echo -n $"Applying $IPTABLES 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
    
    # Tuntap initialization

    if [ -z "$taps" -a -r /etc/planetlab/node_id ] ; then
        # If this node is not "virtually multi-homed", just bring up
        # the tap interface with a PLB private address. The PLB
        # convention is to assign a unique 10.x.y.0/24 network to each
        # node where x.y is the PlanetLab node ID of the machine in
        # host order:
        #
        # x = (node_id / 256) % 256
        # y = node_id % 256
        #
        node_id=$(cat /etc/planetlab/node_id)
        taps="tap0"
        tap0=$(printf 10.%d.%d.1 $((($node_id / 256) % 256)) $(($node_id % 256)))
        tapmask=255.0.0.0
    fi

    # Load additional modules (helpers)
    if [ -n "$IPTABLES_MODULES" ]; then
	echo -n $"Loading additional $IPTABLES 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

    for tap in $taps ; do
        # Configuration for this tap (address/proxy)
        eval cfg=\$$tap
        addr=${cfg%/*}
        proxy=${cfg#*/}

        # Set MAC address to something predictable
        mac=$(printf 00:FF:%X:%X:%X:%X $(echo $addr | sed -e 's/\./ /g'))

        # Bring up this interface. Optimize the MTU for the PlanetLab
        # Backbone (1500/Ethernet - 4/GRE - 8/UDP - 20/IP = 1468).
            ifconfig $tap down && \
            ifconfig $tap hw ether $mac mtu 1468 && \
            ifconfig $tap $addr ${proxy:+pointopoint $proxy} netmask ${tapmask:=255.255.255.255} up

        # Stuffing the proxy for this address in the pointopoint field
        # creates a static route to the proxy that we do not want
        # present.
        if [ -n "$proxy" -a "$proxy" != "$addr" ] ; then
                ip route del $proxy
        fi

        # Enable route through this interface
            ip route add default dev $tap tab 1 && \
            ip rule add from $addr tab 1
    done

    
    touch $VAR_SUBSYS_IPTABLES
    return $ret
}

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

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

    # Take down vnet interfaces
    for dev in $taps tap0 ; do
        action $"Shutting down interface $dev: " \
            ifconfig $dev 0.0.0.0 down
    done		

    rm -f $VAR_SUBSYS_IPTABLES
    return $ret
}

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

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

    echo -n $"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() {
    # Do not print status if lockfile is missing and iptables modules are not 
    # loaded.
    # Check if iptable module is loaded
    if [ ! -f "$VAR_SUBSYS_IPTABLES" ]; then
	echo $"Firewall is stopped."
	return 1
    fi

    # Check if firewall is configured (has tables)
    if [ ! -e "$PROC_IPTABLES_NAMES" ]; then
	echo $"Firewall is not configured. "
	return 1
    fi
    tables=`cat $PROC_IPTABLES_NAMES 2>/dev/null`
    if [ -z "$tables" ]; then
	echo $"Firewall is not configured. "
	return 1
    fi

    NUM=
    [ "x$IPTABLES_STATUS_NUMERIC" = "xyes" ] && NUM="-n"

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

    return 0
}

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

case "$1" in
    start)
	stop
	start
	RETVAL=$?
	;;
    stop)
	[ "x$IPTABLES_SAVE_ON_STOP" = "xyes" ] && save
	stop
	RETVAL=$?
	;;
    restart)
	restart
	RETVAL=$?
	;;
    condrestart)
	[ -e "$VAR_SUBSYS_IPTABLES" ] && 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