#!/bin/bash
#
# Startup script handle the initialisation of LVS
# chkconfig: - 28 72
# description: Initialise the Linux Virtual Server
# config: /etc/sysconfig/ipvsadm
#
### BEGIN INIT INFO
# Provides: ipvsadm
# Required-Start: $local_fs $network $named
# Required-Stop: $local_fs $remote_fs $network
# Short-Description: Initialise the Linux Virtual Server
# Description: The Linux Virtual Server is a highly scalable and highly
#   available server built on a cluster of real servers, with the load
#   balancer running on Linux.
### END INIT INFO

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

IPVSADM=ipvsadm
IPVSADMRESTORE=${IPVSADM}-restore
IPVSADMSAVE=${IPVSADM}-save
# Saved IPVS data
IPVSADM_DATA=/etc/sysconfig/$IPVSADM
# Configuration
IPVSADM_CONFIG=/etc/sysconfig/${IPVSADM}-config
IPVS=ip_vs
PROC_IPVS=/proc/net/$IPVS
VAR_SUBSYS_IPVSADM=/var/lock/subsys/$IPVSADM

if [ ! -x /sbin/$IPVSADM ]; then
    echo -n $"${IPVSADM}: /sbin/$IPVSADM 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 IPVSADM configuration:
IPVS_MODULES_UNLOAD="yes"
IPVS_SAVE_ON_STOP="no"
IPVS_SAVE_ON_RESTART="no"
IPVS_STATUS_NUMERIC="yes"

# Load IPVSADM configuration.
[ -f "$IPVSADM_CONFIG" ] && . "$IPVSADM_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 "/^${mod}[[:space:]]/ { print \$4; }" | tr ',' ' ') \
        || ref=$(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
}

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

    # If we don't clear these first, we might be adding to pre-existing rules.
    action $"${IPVSADM}: Clearing the current IPVS table:" $IPVSADM -C

    echo -n $"${IPVSADM}: Applying IPVS configuration: "
    $IPVSADMRESTORE < ${IPVSADM_DATA}
    if [ $? -eq 0 ];then success; echo; else failure; echo; return 1;fi

    touch $VAR_SUBSYS_IPVSADM
}

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

    action $"${IPVSADM}: Clearing the current IPVS table:" $IPVSADM -C

    ret=0

    if [ "x$IPVS_MODULES_UNLOAD" = "xyes" ]; then
        action $"${IPVSADM}: Unloading modules:" rmmod_r $IPVS
        [ $? -ne 0 ] && ret=1
    fi

    rm -f $VAR_SUBSYS_IPVSADM

    return $ret
}

status() {
    # Do not print status if lockfile is missing and ipvs modules are not
    # loaded.
    if [ ! -f "$VAR_SUBSYS_IPVSADM" -a ! -e "$PROC_IPVS" ]; then
        echo $"${IPVSADM}: IPVS is not running."
        return 3
    fi

    # Do show status if ipvs module is not loaded.
    if [ ! -e "$PROC_IPVS" ];then
        echo $"${IPVSADM}: IPVS module is not loaded."
        return 3
    fi

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

    $IPVSADM -L $NUM && echo
}

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

    echo -n $"${IPVSADM}: Saving IPVS table to ${IPVSADM_DATA}: "
    $IPVSADMSAVE -n > ${IPVSADM_DATA} 2>/dev/null
    if [ $? -eq 0 ];then success; echo; else failure; echo; return 1;fi

    return 0
}

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

# See how we were called.
case "$1" in
    start)
        [ -f "$VAR_SUBSYS_IPVSADM" ] && exit 0

        # If we have no configuration, save the current one
        [ -f ${IPVSADM_DATA} ] || save
        start
        RETVAL=$?
        ;;
    stop)
        [ "x$IPVS_SAVE_ON_STOP" = "xyes" ] && save
        stop
        RETVAL=$?
        ;;
    restart|force-reload)
        restart
        RETVAL=$?
        ;;
    reload)
        # Start will flush everything, so it counts as a reload
        start
        RETVAL=$?
        ;;
    status)
        status
        RETVAL=$?
        ;;
    save)
        save
        RETVAL=$?
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|force-reload|reload|status|save}"
        RETVAL=2
esac

exit $RETVAL