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shorewall_code/Shorewall/lib.common

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#!/bin/sh
#
# Shorewall 4.4 -- /usr/share/shorewall/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.
#
# The purpose of this library is to hold those functions used by both the CLI and by the
# generated firewall scripts. To avoid versioning issues, it is copied into generated
# scripts rather than loaded at run-time.
#
#
# Get the Shorewall version of the passed script
#
get_script_version() { # $1 = script
local temp
local version
local ifs
local digits
local verbosity
verbosity="$VERBOSITY"
VERBOSITY=0
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 $version
VERBOSITY="$verbosity"
}
#
# Do required exports or 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" != Shorewall ]; then
#
# Shorewall Lite
#
export LOGFORMAT
export IPTABLES
fi
else
#
# 4.4.8 or later -- no additional exports required
#
if [ x$1 = xtrace -o x$1 = xdebug ]; then
options="$1 -"
shift;
else
options='-'
fi
[ -n "$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
}
#
# 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"
#
shorewall_is_started() {
qt $IPTABLES -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 $DONT_LOAD $MODULES; 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
local uname
if ! qt mywhich modprobe; then
moduleloader=insmod
fi
[ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]
[ -z "$MODULESDIR" ] && \
uname=$(uname -r) && \
MODULESDIR=/lib/modules/$uname/kernel/net/ipv4/netfilter:/lib/modules/$uname/kernel/net/netfilter:/lib/modules/$uname/kernel/net/sched:/lib/modules/$uname/extra:/lib/modules/$uname/extra/ipset
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=${1:-Yes} # So old compiled scripts still work
local uname
if ! qt mywhich modprobe; then
moduleloader=insmod
fi
[ -n "${MODULE_SUFFIX:=o gz ko o.gz ko.gz}" ]
[ -z "$MODULESDIR" ] && \
uname=$(uname -r) && \
MODULESDIR=/lib/modules/$uname/kernel/net/ipv4/netfilter:/lib/modules/$uname/kernel/net/netfilter:/lib/modules/$uname/kernel/net/sched:/lib/modules/$uname/extra:/lib/modules/$uname/extra/ipset
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
}
#
# Note: The following set of IP address manipulation functions have anomalous
# behavior when the shell only supports 32-bit signed arithmetic and
# the IP address is 128.0.0.0 or 128.0.0.1.
#
LEFTSHIFT='<<'
#
# Convert an IP address in dot quad format to an integer
#
decodeaddr() {
local x
local temp
temp=0
local ifs
ifs=$IFS
IFS=.
for x in $1; do
temp=$(( $(( $temp $LEFTSHIFT 8 )) | $x ))
done
echo $temp
IFS=$ifs
}
#
# convert an integer to dot quad format
#
encodeaddr() {
addr=$1
local x
local y
y=$(($addr & 255))
for x in 1 2 3 ; do
addr=$(($addr >> 8))
y=$(($addr & 255)).$y
done
echo $y
}
#
# Netmask from CIDR
#
ip_netmask() {
local vlsm
vlsm=${1#*/}
[ $vlsm -eq 0 ] && echo 0 || echo $(( -1 $LEFTSHIFT $(( 32 - $vlsm )) ))
}
#
# Network address from CIDR
#
ip_network() {
local decodedaddr
decodedaddr=$(decodeaddr ${1%/*})
local netmask
netmask=$(ip_netmask $1)
echo $(encodeaddr $(($decodedaddr & $netmask)))
}
#
# The following hack is supplied to compensate for the fact that many of
# the popular light-weight Bourne shell derivatives don't support XOR ("^").
#
ip_broadcast() {
local x
x=$(( 32 - ${1#*/} ))
[ $x -eq 32 ] && echo -1 || echo $(( $(( 1 $LEFTSHIFT $x )) - 1 ))
}
#
# Calculate broadcast address from CIDR
#
broadcastaddress() {
local decodedaddr
decodedaddr=$(decodeaddr ${1%/*})
local netmask
netmask=$(ip_netmask $1)
local broadcast
broadcast=$(ip_broadcast $1)
echo $(encodeaddr $(( $(($decodedaddr & $netmask)) | $broadcast )))
}
#
# Test for network membership
#
in_network() # $1 = IP address, $2 = CIDR network
{
local netmask
netmask=$(ip_netmask $2)
#
# Use string comparison to work around a broken BusyBox ash in OpenWRT
#
test $(( $(decodeaddr $1) & $netmask)) = $(( $(decodeaddr ${2%/*}) & $netmask ))
}
#
# 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:-ip} -f inet addr show $1 2> /dev/null | grep 'inet .* global' | head -n1)
#
# If there wasn't one, bail out now
#
[ -n "$addr" ] || startup_error "Can't determine the IP 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*inet //;s/\/.*//;s/ peer.*//'
}
find_first_interface_address_if_any() # $1 = interface
{
#
# get the line of output containing the first IP address
#
addr=$(${IP:-ip} -f inet addr show $1 2> /dev/null | grep 'inet .* global' | head -n1)
#
# Strip off the trailing VLSM mask (or the peer IP in case of a P-t-P link)
# along with everything else on the line
#
[ -n "$addr" ] && echo $addr | sed 's/\s*inet //;s/\/.*//;s/ peer.*//' || echo 0.0.0.0
}
#
# 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
}
#
# Query NetFilter about the existence of a filter chain
#
chain_exists() # $1 = chain name
{
qt1 $IPTABLES -L $1 -n
}
#
# 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 $2
{
if [ $# -gt 1 ]; then
echo "$1 ($(date)) from $2" > ${VARDIR}/state
else
echo "$1 ($(date))" > ${VARDIR}/state
fi
}
#
# 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}
}