shorewall_code/Shorewall/functions

#!/bin/sh
#
# Shorewall 1.4 -- /usr/lib/shorewall/functions

#
# Suppress all output for a command
#
qt()
{
    "$@" >/dev/null 2>&1
}

#
# Find a File -- Look first in $SHOREWALL_DIR then in /etc/shorewall
#
find_file()
{
    if [ -n "$SHOREWALL_DIR" -a -f $SHOREWALL_DIR/$1 ]; then
    	echo $SHOREWALL_DIR/$1
    else
    	echo /etc/shorewall/$1
    fi
}

#
# Replace commas with spaces and echo the result
#
separate_list() {
    local list
    local part
    local newlist
    #
    # There's been whining about us not catching embedded white space in
    # comma-separated lists. This is an attempt to snag some of the cases.
    #
    # The 'terminator' function will be set by the 'firewall' script to
    # either 'startup_error' or 'fatal_error' depending on the command and
    # command phase
    #
    case "$@" in
	*,|,*|*,,*|*[[:space:]]*)
            [ -n "$terminator" ] && \
		$terminator "Invalid comma-separated list \"$@\""
            echo "Warning -- invalid comma-separated list \"$@\"" >&2
	    ;;
    esac

    list="$@"
    part="${list%%,*}"
    newlist="$part"

    while [ "x$part" != "x$list" ]; do
	list="${list#*,}";
	part="${list%%,*}";
	newlist="$newlist $part";
    done

    echo "$newlist"
}

#
# Find the zones
#
find_zones() # $1 = name of the zone file
{
    while read zone display comments; do
	[ -n "$zone" ] && case "$zone" in
	    \#*)
		;;
            $FW|multi)
	        echo "Reserved zone name \"$zone\" in zones file ignored" >&2
		;;
            *)
		echo $zone
		;;
        esac
    done < $1
}

find_display() # $1 = zone, $2 = name of the zone file
{
    grep ^$1 $2 | while read z display comments; do
	[ "x$1" = "x$z" ] && echo $display
    done
}
#
# This function assumes that the TMP_DIR variable is set and that
# its value named an existing directory.
#
determine_zones()
{
    local zonefile=`find_file zones`

    multi_display=Multi-zone
    strip_file zones $zonefile
    zones=`find_zones $TMP_DIR/zones`
    zones=`echo $zones` # Remove extra trash
    
    for zone in $zones; do
	dsply=`find_display $zone $TMP_DIR/zones`
	eval ${zone}_display=\$dsply
    done
}

#
# The following functions may be used by apps that wish to ensure that
# the state of Shorewall isn't changing
#
# This function loads the STATEDIR variable (directory where Shorewall is to
# store state files). If your application supports alternate Shorewall
# configurations then the name of the alternate configuration directory should
# be in $SHOREWALL_DIR at the time of the call.
#
# If the shorewall.conf file does not exist, this function does not return
#
get_statedir()
{
    MUTEX_TIMEOUT=

    local config=`find_file shorewall.conf`

    if [ -f $config ]; then
       . $config
    else
	echo "/etc/shorewall/shorewall.conf does not exist!" >&2
	exit 2
    fi

    [ -z "${STATEDIR}" ] && STATEDIR=/var/state/shorewall
}

#
# Call this function to assert MUTEX with Shorewall. If you invoke the
# /sbin/shorewall program while holding MUTEX, you should pass "nolock" as
# the first argument. Example "shorewall nolock refresh"
#
# This function uses the lockfile utility from procmail if it exists.
# Otherwise, it uses a somewhat race-prone algorithm to attempt to simulate the
# behavior of lockfile.
#
mutex_on()
{
    local try=0
    local lockf=$STATEDIR/lock

    MUTEX_TIMEOUT=${MUTEX_TIMEOUT:-60}

    if [ $MUTEX_TIMEOUT -gt 0 ]; then

	[ -d $STATEDIR ] || mkdir -p $STATEDIR

	if qt which lockfile; then
	    lockfile -${MUTEX_TIMEOUT} -r1 ${lockf}
	else
	    while [ -f ${lockf} -a ${try} -lt ${MUTEX_TIMEOUT} ] ; do
		sleep 1
		try=$((${try} + 1))
	    done

	    if  [ ${try} -lt ${MUTEX_TIMEOUT} ] ; then
	        # Create the lockfile
		echo $$ > ${lockf}
	    else
		echo "Giving up on lock file ${lockf}" >&2
	    fi
	fi
    fi
}

#
# Call this function to release MUTEX
#
mutex_off()
{
    rm -f $STATEDIR/lock
}

#
# Read a file and handle "INCLUDE" directives
#

read_file() # $1 = file name, $2 = nest count
{
    local first rest

    while read first rest; do
	if [ "x$first"  = "xINCLUDE" ]; then
	    if [ $2 -lt 4 ]; then
		read_file `find_file ${rest%#*}` $(($2 + 1))
	    else
		echo "   WARNING: INCLUDE in $1 ignored (nested too deeply)" >&2
	    fi
	else
	    echo "$first $rest"
	fi
    done < $1
}

#
# Function for including one file into another
#
INCLUDE() {
    . `find_file $@`
}

#
# Strip comments and blank lines from a file and place the result in the
# temporary directory
#
strip_file() # $1 = Base Name of the file, $2 = Full Name of File (optional)
{
    local fname

    [ $# = 1 ] && fname=`find_file $1` || fname=$2

    if [ -f $fname ]; then
	read_file $fname 0 | cut -d'#' -f1 | grep -v '^[[:space:]]*$' > $TMP_DIR/$1
    else
	> $TMP_DIR/$1
    fi
}