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shorewall_code/Shorewall/functions
2005-07-31 17:15:37 +00:00

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#!/bin/sh
#
# Shorewall 2.6 -- /usr/share/shorewall/functions
# 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}
}
#
# Split a colon-separated list into a space-separated list
#
split() {
local ifs=$IFS
IFS=:
set -- $1
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=$1
while [ $# -gt 1 ]; do
shift
[ "x$e" = "x$1" ] && return 0
done
return 1
}
#
# Functions to count list elements
# - - - - - - - - - - - - - - - -
# Whitespace-separated list
#
list_count1() {
echo $#
}
#
# Comma-separated list
#
list_count() {
list_count1 $(separate_list $1)
}
#
# Conditionally produce message
#
progress_message() # $* = Message
{
[ -n "$QUIET" ] || echo "$@"
}
#
# Suppress all output for a command
#
qt()
{
"$@" >/dev/null 2>&1
}
#
# Perform variable substitution on the passed argument and echo the result
#
expand() # $@ = contents of variable which may be the name of another variable
{
eval echo \"$@\"
}
#
# Perform variable substitition on the values of the passed list of variables
#
expandv() # $* = list of variable names
{
local varval
while [ $# -gt 0 ]; do
eval varval=\$${1}
eval $1=\"$varval\"
shift
done
}
#
# Replace all leading "!" with "! " in the passed argument list
#
fix_bang() {
local i;
for i in $@; do
case $i in
!*)
echo "! ${i#!}"
;;
*)
echo $i
;;
esac
done
}
#
# Set default config path
#
ensure_config_path() {
local F=/usr/share/shorewall/configpath
if [ -z "$CONFIG_PATH" ]; then
[ -f $F ] || { echo " ERROR: $F does not exist"; exit 2; }
. $F
fi
}
#
# Find a File -- For relative file name, look first in $SHOREWALL_DIR then in /etc/shorewall
#
find_file()
{
local saveifs= directory
case $1 in
/*)
echo $1
;;
*)
if [ -n "$SHOREWALL_DIR" -a -f $SHOREWALL_DIR/$1 ]; then
echo $SHOREWALL_DIR/$1
else
saveifs=$IFS
IFS=:
for directory in $CONFIG_PATH; do
if [ -f $directory/$1 ]; then
echo $directory/$1
IFS=$saveifs
return
fi
done
IFS=$saveifs
echo /etc/shorewall/$1
fi
;;
esac
}
#
# Replace commas with spaces and echo the result
#
separate_list() {
local list="$@"
local part
local newlist
local firstpart
local lastpart
local enclosure
case "$list" in
*,|,*|*,,*|*[[:space:]]*)
#
# There's been whining about us not catching embedded white space in
# comma-separated lists. This is an attempt to snag some of the cases.
#
# The 'terminator' function will be set by the 'firewall' script to
# either 'startup_error' or 'fatal_error' depending on the command and
# command phase
#
[ -n "$terminator" ] && \
$terminator "Invalid comma-separated list \"$@\""
echo "WARNING -- invalid comma-separated list \"$@\"" >&2
;;
*\[*\]*)
#
# Where we need to embed comma-separated lists within lists, we enclose them
# within square brackets
#
firstpart=${list%%\[*}
lastpart=${list#*\[}
enclosure=${lastpart%%\]*}
lastpart=${lastpart#*\]}
case $lastpart in
\,*)
case $firstpart in
*\,)
echo "$(separate_list ${firstpart%,}) [$enclosure] $(separate_list ${lastpart#,})"
;;
*)
echo "$(separate_list $firstpart)[$enclosure] $(separate_list ${lastpart#,})"
;;
esac
;;
*)
case $firstpart in
*\,)
echo "$(separate_list ${firstpart%,}) [$enclosure]$(separate_list $lastpart)"
;;
*)
echo "$(separate_list $firstpart)[$enclosure]$(separate_list $lastpart)"
;;
esac
;;
esac
return
;;
esac
list="$@"
part="${list%%,*}"
newlist="$part"
while [ "x$part" != "x$list" ]; do
list="${list#*,}";
part="${list%%,*}";
newlist="$newlist $part";
done
echo "$newlist"
}
#
# Load a Kernel Module
#
loadmodule() # $1 = module name, $2 - * arguments
{
local modulename=$1
local modulefile
local suffix
moduleloader=modprobe
if ! qt mywhich modprobe; then
moduleloader=insmod
fi
if [ -z "$(lsmod | grep $modulename)" ]; then
shift
for suffix in $MODULE_SUFFIX ; do
modulefile=$MODULESDIR/${modulename}.${suffix}
if [ -f $modulefile ]; then
case $moduleloader in
insmod)
insmod $modulefile $*
;;
*)
modprobe $modulename $*
;;
esac
return
fi
done
fi
}
#
# Reload the Modules
#
reload_kernel_modules() {
[ -z "$MODULESDIR" ] && MODULESDIR=/lib/modules/$(uname -r)/kernel/net/ipv4/netfilter
while read command; do
eval $command
done
}
#
# Call this function to assert MUTEX with Shorewall. If you invoke the
# /sbin/shorewall program while holding MUTEX, you should pass "nolock" as
# the first argument. Example "shorewall nolock refresh"
#
# This function uses the lockfile utility from procmail if it exists.
# Otherwise, it uses a somewhat race-prone algorithm to attempt to simulate the
# behavior of lockfile.
#
mutex_on()
{
local try=0
local lockf=/var/lib/shorewall/lock
MUTEX_TIMEOUT=${MUTEX_TIMEOUT:-60}
if [ $MUTEX_TIMEOUT -gt 0 ]; then
[ -d /var/lib/shorewall ] || mkdir -p /var/lib/shorewall
if qt mywhich lockfile; then
lockfile -${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 $$ > ${lockf}
else
echo "Giving up on lock file ${lockf}" >&2
fi
fi
fi
}
#
# Call this function to release MUTEX
#
mutex_off()
{
rm -f /var/lib/shorewall/lock
}
#
# Determine which version of mktemp is present (if any) and set MKTEMP accortingly:
#
# None - No mktemp
# BSD - BSD mktemp (Mandrake)
# STD - mktemp.org mktemp
#
find_mktemp() {
local mktemp=`mywhich mktemp 2> /dev/null`
if [ -n "$mktemp" ]; then
if qt mktemp -V ; then
MKTEMP=STD
else
MKTEMP=BSD
fi
else
MKTEMP=None
fi
}
#
# create a temporary file. If a directory name is passed, the file will be created in
# that directory. Otherwise, it will be created in a temporary directory.
#
mktempfile() {
[ -z "$MKTEMP" ] && find_mktemp
if [ $# -gt 0 ]; then
case "$MKTEMP" in
BSD)
mktemp $1/shorewall.XXXXXX
;;
STD)
mktemp -p $1 shorewall.XXXXXX
;;
None)
> $1/shorewall-$$ && echo $1/shorewall-$$
;;
*)
echo " ERROR:Internal error in mktempfile" >&2
;;
esac
else
case "$MKTEMP" in
BSD)
mktemp /tmp/shorewall.XXXXXX
;;
STD)
mktemp -t shorewall.XXXXXX
;;
None)
rm -f /tmp/shorewall-$$
> /tmp/shorewall-$$ && echo /tmp/shorewall-$$
;;
*)
echo " ERROR:Internal error in mktempfile" >&2
;;
esac
fi
}
#
# create a temporary directory
#
mktempdir() {
[ -z "$MKTEMP" ] && find_mktemp
case "$MKTEMP" in
STD)
mktemp -td shorewall.XXXXXX
;;
None|BSD)
#
# Not all versions of the BSD mktemp support the -d option under Linux
#
mkdir /tmp/shorewall-$$ && chmod 700 /tmp/shorewall-$$ && echo /tmp/shorewall-$$
;;
*)
echo " ERROR:Internal error in mktempdir" >&2
;;
esac
}
#
# Read a file and handle "INCLUDE" directives
#
read_file() # $1 = file name, $2 = nest count
{
local first rest
if [ -f $1 ]; then
while read first rest; do
if [ "x$first" = "xINCLUDE" ]; then
if [ $2 -lt 4 ]; then
read_file $(find_file $(expand ${rest%#*})) $(($2 + 1))
else
echo " WARNING: INCLUDE in $1 ignored (nested too deeply)" >&2
fi
else
echo "$first $rest"
fi
done < $1
else
[ -n "$terminator" ] && $terminator "No such file: $1"
echo "WARNING -- No such file: $1"
fi
}
#
# Function for including one file into another
#
INCLUDE() {
. $(find_file $(expand $@))
}
#
# 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
}
#
# Note: The following set of IP address manipulation functions have anomalous
# behavior when the shell only supports 32-bit signed arithmatic and
# the IP address is 128.0.0.0 or 128.0.0.1.
#
#
# So that emacs doesn't get lost, we use $LEFTSHIFT rather than <<
#
LEFTSHIFT='<<'
#
# Convert an IP address in dot quad format to an integer
#
decodeaddr() {
local x
local temp=0
local ifs=$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=$1
local x
local y=$(($addr & 255))
for x in 1 2 3 ; do
addr=$(($addr >> 8))
y=$(($addr & 255)).$y
done
echo $y
}
#
# Enumerate the members of an IP range -- When using a shell supporting only
# 32-bit signed arithmetic, the range cannot span 128.0.0.0.
#
# Comes in two flavors:
#
# ip_range() - produces a mimimal list of network/host addresses that spans
# the range.
#
# ip_range_explicit() - explicitly enumerates the range.
#
ip_range() {
local first last l x y z vlsm
case $1 in
!*)
#
# Let iptables complain if it's a range
#
echo $1
return
;;
[0-9]*.*.*.*-*.*.*.*)
;;
*)
echo $1
return
;;
esac
first=$(decodeaddr ${1%-*})
last=$(decodeaddr ${1#*-})
if [ $first -gt $last ]; then
fatal_error "Invalid IP address range: $1"
fi
l=$(( $last + 1 ))
while [ $first -le $last ]; do
vlsm=
x=31
y=2
z=1
while [ $(( $first % $y )) -eq 0 -a $(( $first + $y )) -le $l ]; do
vlsm=/$x
x=$(( $x - 1 ))
z=$y
y=$(( $y * 2 ))
done
echo $(encodeaddr $first)$vlsm
first=$(($first + $z))
done
}
ip_range_explicit() {
local first last
case $1 in
[0-9]*.*.*.*-*.*.*.*)
;;
*)
echo $1
return
;;
esac
first=$(decodeaddr ${1%-*})
last=$(decodeaddr ${1#*-})
if [ $first -gt $last ]; then
fatal_error "Invalid IP address range: $1"
fi
while [ $first -le $last ]; do
echo $(encodeaddr $first)
first=$(($first + 1))
done
}
#
# Netmask from CIDR
#
ip_netmask() {
local vlsm=${1#*/}
[ $vlsm -eq 0 ] && echo 0 || echo $(( -1 $LEFTSHIFT $(( 32 - $vlsm )) ))
}
#
# Network address from CIDR
#
ip_network() {
local decodedaddr=$(decodeaddr ${1%/*})
local netmask=$(ip_netmask $1)
echo $(encodeaddr $(($decodedaddr & $netmask)))
}
#
# The following hack is supplied to compensate for the fact that many of
# the popular light-weight Bourne shell derivatives don't support XOR ("^").
#
ip_broadcast() {
local x=$(( 32 - ${1#*/} ))
[ $x -eq 0 ] && echo -1 || echo $(( $(( 1 $LEFTSHIFT $x )) - 1 ))
}
#
# Calculate broadcast address from CIDR
#
broadcastaddress() {
local decodedaddr=$(decodeaddr ${1%/*})
local netmask=$(ip_netmask $1)
local broadcast=$(ip_broadcast $1)
echo $(encodeaddr $(( $(($decodedaddr & $netmask)) | $broadcast )))
}
#
# Test for network membership
#
in_network() # $1 = IP address, $2 = CIDR network
{
local netmask=$(ip_netmask $2)
test $(( $(decodeaddr $1) & $netmask)) -eq $(( $(decodeaddr ${2%/*}) & $netmask ))
}
#
# Netmask to VLSM
#
ip_vlsm() {
local mask=$(decodeaddr $1)
local vlsm=0
local x=$(( 128 $LEFTSHIFT 24 )) # 0x80000000
while [ $(( $x & $mask )) -ne 0 ]; do
[ $mask -eq $x ] && mask=0 || mask=$(( $mask $LEFTSHIFT 1 )) # Not all shells shift 0x80000000 left properly.
vlsm=$(($vlsm + 1))
done
if [ $(( $mask & 2147483647 )) -ne 0 ]; then # 2147483647 = 0x7fffffff
echo "Invalid net mask: $1" >&2
else
echo $vlsm
fi
}
#
# Chain name base for an interface -- replace all periods with underscores in the passed name.
# The result is echoed (less trailing "+").
#
chain_base() #$1 = interface
{
local c=${1%%+}
while true; do
case $c in
*.*)
c="${c%.*}_${c##*.}"
;;
*-*)
c="${c%-*}_${c##*-}"
;;
*%*)
c="${c%\%*}_${c##*%}"
;;
*)
echo ${c:=common}
return
;;
esac
done
}
#
# Loosly Match the name of an interface
#
if_match() # $1 = Name in interfaces file - may end in "+"
# $2 = Full interface name - may also end in "+"
{
local pattern=${1%+}
case $1 in
*+)
test "x$(echo $2 | truncate ${#pattern} )" = "x${pattern}"
;;
*)
test "x$1" = "x$2"
;;
esac
}
#
# Find the value 'dev' in the passed arguments then echo the next value
#
find_device() {
while [ $# -gt 1 ]; do
[ "x$1" = xdev ] && echo $2 && return
shift
done
}
#
# Find the value 'via' in the passed arguments then echo the next value
#
find_gateway() {
while [ $# -gt 1 ]; do
[ "x$1" = xvia ] && echo $2 && return
shift
done
}
#
# Find the value 'peer' in the passed arguments then echo the next value up to
# "/"
#
find_peer() {
while [ $# -gt 1 ]; do
[ "x$1" = xpeer ] && echo ${2%/*} && return
shift
done
}
#
# Find the interfaces that have a route to the passed address - the default
# route is not used.
#
find_rt_interface() {
ip route ls | while read addr rest; do
case $addr in
*/*)
in_network ${1%/*} $addr && echo $(find_device $rest)
;;
default)
;;
*)
if [ "$addr" = "$1" -o "$addr/32" = "$1" ]; then
echo $(find_device $rest)
fi
;;
esac
done
}
#
# Try to find the gateway through an interface looking for 'nexthop'
find_nexthop() # $1 = interface
{
echo $(find_gateway `ip route ls | grep "[[:space:]]nexthop.* $1"`)
}
#
# Find the default route's interface
#
find_default_interface() {
ip route ls | while read first rest; do
[ "$first" = default ] && echo $(find_device $rest) && return
done
}
#
# Echo the name of the interface(s) that will be used to send to the
# passed address
#
find_interface_by_address() {
local dev="$(find_rt_interface $1)"
local first rest
[ -z "$dev" ] && dev=$(find_default_interface)
[ -n "$dev" ] && echo $dev
}
#
# Find interface addresses--returns the set of addresses assigned to the passed
# device
#
find_interface_addresses() # $1 = interface
{
ip -f inet addr show $1 | grep inet | sed 's/inet //;s/\/.*//;s/ peer.*//'
}
#
# 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
}
#
# Set the Shorewall state
#
set_state () # $1 = state
{
echo "$1 ($(date))" > /var/lib/shorewall/state
}