#!/bin/sh
#
# Shorewall 4.4 -- /usr/share/shorewall6/lib.common.
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 2010 - Tom Eastep (teastep@shorewall.net)
#
#	Complete documentation is available at http://shorewall.net
#
#	This program is free software; you can redistribute it and/or modify
#	it under the terms of Version 2 of the GNU General Public License
#	as published by the Free Software Foundation.
#
#	This program is distributed in the hope that it will be useful,
#	but WITHOUT ANY WARRANTY; without even the implied warranty of
#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
#	GNU General Public License for more details.
#
#	You should have received a copy of the GNU General Public License
#	along with this program; if not, write to the Free Software
#	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# This library contains the wrapper code for running a generated script.
#

#
# Get the Shorewall version of the passed script
#
get_script_version() { # $1 = script
    local temp
    local version
    local ifs
    local digits

    temp=$( $SHOREWALL_SHELL $1 version | sed 's/-.*//' )

    if [ $? -ne 0 ]; then
	version=0
    else
	ifs=$IFS
	IFS=.
	temp=$(echo $temp)
	IFS=$ifs
	digits=0
	
	for temp in $temp; do
	    version=${version}$(printf '%02d' $temp)
	    digits=$(($digits + 1))
	    [ $digits -eq 3 ] && break
	done
    fi
    
    echo $version
}
  
#
# Do required exports and create the required option string and run the passed script using
# $SHOREWALL_SHELL
#
run_it() {
    local script
    local options
    local version

    export VARDIR
	
    script=$1
    shift

    version=$(get_script_version $script)

    if [ $version -lt 040408 ]; then
	#
	# Old script that doesn't understand 4.4.8 script options
	#
	export RESTOREFILE=
	export VERBOSITY
	export NOROUTES=$g_noroutes
	export PURGE=$g_purge
	export TIMESTAMP=$g_timestamp
	export RECOVERING=$g_recovering

	if [ "$g_product" != Shorewall6 ]; then
	    #
	    # Shorewall6 Lite
	    #
	    export LOGFORMAT
	    export IP6TABLES
	fi
    else
	#
	# 4.4.8 or later -- no additional exports required
	#
	options='-'

	[ -n "$g_noroutes" ]   && options=${options}n
	[ -n "$g_timestamp" ]  && options=${options}t
	[ -n "$g_purge" ]      && options=${options}p
	[ -n "$g_recovering" ] && options=${options}r

	options="${options}V $VERBOSITY"

	[ -n "$RESTOREFILE" ] && options="${options} -R $RESTOREFILE"
    fi

    $SHOREWALL_SHELL $script $options $@
}

#
# Message to stderr
#
error_message() # $* = Error Message
{
   echo "   $@" >&2
}

#
# Split a colon-separated list into a space-separated list
#
split() {
    local ifs
    ifs=$IFS
    IFS=:
    echo $*
    IFS=$ifs
}

#
# Undo the effect of 'split()'
#
join()
{
    local f
    local o
    o=

    for f in $* ; do
        o="${o:+$o:}$f"
    done

    echo $o
}

#
# Return the number of elements in a list
#
list_count() # $* = list
{
    return $#
}

#
# Search a list looking for a match -- returns zero if a match found
# 1 otherwise
#
list_search() # $1 = element to search for , $2-$n = list
{
    local e
    e=$1

    while [ $# -gt 1 ]; do
	shift
	[ "x$e" = "x$1" ] && return 0
    done

    return 1
}

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

qt1()
{
    local status

    while [ 1 ]; do
	"$@" >/dev/null 2>&1
	status=$?
	[ $status -ne 4 ] && return $status
    done
}

#
# Determine if Shorewall is "running"
#
shorewall6_is_started() {
    qt1 $IP6TABLES -L shorewall -n
}

#
# Echos the fully-qualified name of the calling shell program
#
my_pathname() {
    cd $(dirname $0)
    echo $PWD/$(basename $0)
}

#
# Source a user exit file if it exists
#
run_user_exit() # $1 = file name
{
    local user_exit
    user_exit=$(find_file $1)

    if [ -f $user_exit ]; then
	progress_message "Processing $user_exit ..."
	. $user_exit
    fi
}

#
# Load a Kernel Module -- assumes that the variable 'moduledirectories' contains
#                         a space-separated list of directories to search for
#                         the module and that 'moduleloader' contains the
#                         module loader command.
#
loadmodule() # $1 = module name, $2 - * arguments
{
    local modulename
    modulename=$1
    local modulefile
    local suffix

    if ! list_search $modulename $MODULES $DONT_LOAD ; then
	shift

	for suffix in $MODULE_SUFFIX ; do
	    for directory in $moduledirectories; do
		modulefile=$directory/${modulename}.${suffix}

		if [ -f $modulefile ]; then
		    case $moduleloader in
			insmod)
			    insmod $modulefile $*
			    ;;
			*)
			    modprobe $modulename $*
			    ;;
		    esac
		    break 2
		fi
	    done
	done
    fi
}

#
# Reload the Modules
#
reload_kernel_modules() {

    local save_modules_dir
    save_modules_dir=$MODULESDIR
    local directory
    local moduledirectories
    moduledirectories=
    local moduleloader
    moduleloader=modprobe

    if ! qt mywhich modprobe; then
	moduleloader=insmod
    fi

    [ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]

    [ -z "$MODULESDIR" ] && MODULESDIR=/lib/modules/$(uname -r)/kernel/net/ipv6/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter:/lib/modules/$(uname -r)/kernel/net/sched
    MODULES=$(lsmod | cut -d ' ' -f1)

    for directory in $(split $MODULESDIR); do
	[ -d $directory ] && moduledirectories="$moduledirectories $directory"
    done

    [ -n "$moduledirectories" ] && while read command; do
	eval $command
    done

    MODULESDIR=$save_modules_dir
}

#
# Load kernel modules required for Shorewall
#
load_kernel_modules() # $1 = Yes, if we are to save moduleinfo in $VARDIR
{
    local save_modules_dir
    save_modules_dir=$MODULESDIR
    local directory
    local moduledirectories
    moduledirectories=
    local moduleloader
    moduleloader=modprobe
    local savemoduleinfo
    savemoduleinfo=${1:-Yes} # So old compiled scripts still work

    if ! qt mywhich modprobe; then
	moduleloader=insmod
    fi

    [ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]

    [ -z "$MODULESDIR" ] && \
	MODULESDIR=/lib/modules/$(uname -r)/kernel/net/ipv6/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter:/lib/modules/$(uname -r)/kernel/net/sched

    for directory in $(split $MODULESDIR); do
	[ -d $directory ] && moduledirectories="$moduledirectories $directory"
    done

    [ -n "$LOAD_HELPERS_ONLY" ] && modules=$(find_file helpers) || modules=$(find_file modules)

    if [ -f $modules -a -n "$moduledirectories" ]; then
	MODULES=$(lsmod | cut -d ' ' -f1)
	progress_message "Loading Modules..."
	. $modules
	if [ $savemoduleinfo = Yes ]; then
	    [ -d ${VARDIR} ] || mkdir -p ${VARDIR}
	    echo MODULESDIR="$MODULESDIR" > ${VARDIR}/.modulesdir
	    cp -f $modules ${VARDIR}/.modules
	fi
    elif [ $savemoduleinfo = Yes ]; then
	[ -d ${VARDIR} ] || mkdir -p ${VARDIR}
	> ${VARDIR}/.modulesdir	
	> ${VARDIR}/.modules
    fi

    MODULESDIR=$save_modules_dir
}

#
# Query NetFilter about the existence of a filter chain
#
chain_exists() # $1 = chain name
{
    qt1 $IP6TABLES -L $1 -n
}

#
# Find the interface with the passed MAC address
#

find_interface_by_mac() {
    local mac
    mac=$1
    local first
    local second
    local rest
    local dev

    $IP link list | while read first second rest; do
	case $first in
	    *:)
                dev=$second
		;;
	    *)
	        if [ "$second" = $mac ]; then
		    echo ${dev%:}
		    return
		fi
	esac
    done
}

#
# Find interface address--returns the first IP address assigned to the passed
# device
#
find_first_interface_address() # $1 = interface
{
    #
    # get the line of output containing the first IP address
    #
    addr=$($IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 .* global' | head -n1)
    #
    # If there wasn't one, bail out now
    #
    [ -n "$addr" ] || startup_error "Can't determine the IPv6 address of $1"
    #
    # Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
    # along with everything else on the line
    #
    echo $addr | sed 's/\s*inet6 //;s/\/.*//;s/ peer.*//'
}

find_first_interface_address_if_any() # $1 = interface
{
    #
    # get the line of output containing the first IP address
    #
    addr=$($IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 2.* global' | head -n1)
    #
    # Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
    # along with everything else on the line
    #
    [ -n "$addr" ] && echo $addr | sed 's/\s*inet6 //;s/\/.*//;s/ peer.*//' || echo ::
}

#
# Internal version of 'which'
#
mywhich() {
    local dir

    for dir in $(split $PATH); do
	if [ -x $dir/$1 ]; then
	    echo $dir/$1
	    return 0
	fi
    done

    return 2
}

#
# Find a File -- For relative file name, look in each ${CONFIG_PATH} then ${CONFDIR}
#
find_file()
{
    local saveifs
    saveifs=
    local directory

    case $1 in
	/*)
	    echo $1
	    ;;
	*)
	    for directory in $(split $CONFIG_PATH); do
		if [ -f $directory/$1 ]; then
		    echo $directory/$1
		    return
		fi
	    done

	    echo ${CONFDIR}/$1
	    ;;
    esac
}

#
# Set the Shorewall state
#
set_state () # $1 = state
{
    echo "$1 ($(date))" > ${VARDIR}/state
}

#
# Perform variable substitution on the passed argument and echo the result
#
expand() # $@ = contents of variable which may be the name of another variable
{
    eval echo \"$@\"
}

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

# Function to truncate a string -- It uses 'cut -b -<n>'
# rather than ${v:first:last} because light-weight shells like ash and
# dash do not support that form of expansion.
#

truncate() # $1 = length
{
    cut -b -${1}
}