#!/bin/sh
#
#     Generated by the Shoreline Firewall (Shorewall) Packet Filtering Firewall - V3.4
#
#     This program is under GPL [http://www.gnu.org/copyleft/gpl.htm]
#
#     (c) 2006 - Tom Eastep (teastep@shorewall.net)
#
#
#	Options are:
#
#	    -n				  Don't alter Routing
#	    -v and -q			  Standard Shorewall Verbosity control
#
#	Commands are:
#
#	   start			  Starts the firewall
#          refresh                        Refresh the firewall
#	   restart			  Restarts the firewall
#	   reload			  Reload the firewall
#	   clear			  Removes all firewall rules
#	   stop				  Stops the firewall
#	   status			  Displays firewall status
#	   version			  Displays the version of Shorewall that
#	   				  generated this program
#
#
# Message to stderr
#
error_message() # $* = Error Message
{
   echo "   $@" >&2
}

#
# Conditionally produce message
#
progress_message() # $* = Message
{
    local timestamp=

    if [ $VERBOSE -gt 1 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi
}

progress_message2() # $* = Message
{
    local timestamp=

    if [ $VERBOSE -gt 0 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi
}

progress_message3() # $* = Message
{
    local timestamp=

    if [ $VERBOSE -ge 0 ]; then
	[ -n "$TIMESTAMP" ] && timestamp="$(date +%H:%M:%S) "
	echo "${timestamp}$@"
    fi
}

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

#
# 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)
}

#
# Set a standard chain's policy
#
setpolicy() # $1 = name of chain, $2 = policy
{
    run_iptables -P $1 $2
}

#
# Set a standard chain to enable established and related connections
#
setcontinue() # $1 = name of chain
{
    run_iptables -A $1 -m state --state ESTABLISHED,RELATED -j ACCEPT
}

#
# Flush one of the NAT table chains
#
flushnat() # $1 = name of chain
{
    run_iptables -t nat -F $1
}

#
# Flush one of the Mangle table chains
#
flushmangle() # $1 = name of chain
{
    run_iptables -t mangle -F $1
}

#
# Flush and delete all user-defined chains in the filter table
#
deleteallchains() {
    run_iptables -F
    run_iptables -X
}

#
# 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=$1
    local modulefile
    local suffix

    if ! list_search $modulename $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=$MODULESDIR
    local directory
    local moduledirectories=
    local 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/ipv4/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter
    MODULES=$(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 $VARDIR
{
    local save_modules_dir=$MODULESDIR
    local directory
    local moduledirectories=
    local moduleloader=modprobe
    local 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/ipv4/netfilter:/lib/modules/$(uname -r)/kernel/net/netfilter

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

    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 arithmatic and
#        the IP address is 128.0.0.0 or 128.0.0.1.
#

LEFTSHIFT='<<'

#
# Validate an IP address
#
valid_address() {
    local x y
    local ifs=$IFS

    IFS=.

    for x in $1; do
	case $x in
	    [0-9]|[0-9][0-9]|[1-2][0-9][0-9])
		[ $x -lt 256 ] || { IFS=$ifs; return 2; }
                ;;
	    *)
	        IFS=$ifs
		return 2
		;;
	esac
    done
    
    IFS=$ifs

    return 0
}

#
# 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 32 ] && 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 << 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
}

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

#
# 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 'mtu' in the passed arguments then echo the next value
#

find_mtu() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xmtu ] && 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 the interface with the passed MAC address
#

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

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

#
# Determine if Interface is up
#
interface_is_up() {
    [ -n "$(ip link ls dev $1 2> /dev/null | grep -e '[<,]UP[,>]')" ]
}

#
# 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 inet addr show $1 2> /dev/null | grep 'inet .* global' | head -n1)
    #
    # If there wasn't one, bail out now
    #
    [ -n "$addr" ] || fatal_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 -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
}

#
# Determine if interface is usable from a Netfilter prespective
#
interface_is_usable() # $1 = interface
{
    interface_is_up $1 && [ "$(find_first_interface_address_if_any $1)" != 0.0.0.0 ]
}

#
# Find interface addresses--returns the set of addresses assigned to the passed
# device
#
find_interface_addresses() # $1 = interface
{
    ip -f inet addr show $1 2> /dev/null | grep inet\  | sed 's/\s*inet //;s/\/.*//;s/ peer.*//'
}

#
#  echo the list of networks routed out of a given interface
#
get_routed_networks() # $1 = interface name, $2-n = Fatal error message
{
    local address
    local rest

    ip route show dev $1 2> /dev/null |
	while read address rest; do
	    case "$address" in
		default)
		    if [ $# -gt 1 ]; then
			shift
			fatal_error "$@"
		    else
			echo "WARNING: default route ignored on interface $1" >&2
		    fi
		    ;;
		multicast|broadcast|prohibit|nat|throw|nexthop)
		    ;;
		*)
		    [ "$address" = "${address%/*}" ] && address="${address}/32"
		    echo $address
		    ;;
	    esac
        done
}

get_interface_bcasts() # $1 = interface
{
    local addresses=

    ip -f inet addr show dev $1 2> /dev/null | grep 'inet.*brd' | sed 's/inet.*brd //; s/scope.*//;' | sort -u 
}
	
#
# 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))" > ${VARDIR}/state
}

#
# Determine which optional facilities are supported by iptables/netfilter
#
determine_capabilities() {
    qt $IPTABLES -t nat    -L -n && NAT_ENABLED=Yes    || NAT_ENABLED=
    qt $IPTABLES -t mangle -L -n && MANGLE_ENABLED=Yes || MANGLE_ENABLED=

    CONNTRACK_MATCH=
    MULTIPORT=
    XMULTIPORT=
    POLICY_MATCH=
    PHYSDEV_MATCH=
    IPRANGE_MATCH=
    RECENT_MATCH=
    OWNER_MATCH=
    IPSET_MATCH=
    CONNMARK=
    XCONNMARK=
    CONNMARK_MATCH=
    XCONNMARK_MATCH=
    RAW_TABLE=
    IPP2P_MATCH=
    LENGTH_MATCH=
    CLASSIFY_TARGET=
    ENHANCED_REJECT=
    USEPKTTYPE=
    KLUDGEFREE=
    MARK=
    XMARK=
    MANGLE_FORWARD=
    COMMENTS=
    ADDRTYPE=
    TCPMSS_MATCH=

    qt $IPTABLES -N fooX1234
    qt $IPTABLES -A fooX1234 -m conntrack --ctorigdst 192.168.1.1 -j ACCEPT             && CONNTRACK_MATCH=Yes
    qt $IPTABLES -A fooX1234 -p tcp -m multiport --dports 21,22 -j ACCEPT               && MULTIPORT=Yes
    qt $IPTABLES -A fooX1234 -p tcp -m multiport --dports 21:22 -j ACCEPT               && XMULTIPORT=Yes
    qt $IPTABLES -A fooX1234 -m policy --pol ipsec --mode tunnel --dir in -j ACCEPT     && POLICY_MATCH=Yes

    if qt $IPTABLES -A fooX1234 -m physdev --physdev-out eth0 -j ACCEPT; then
	PHYSDEV_MATCH=Yes
    fi

    if qt $IPTABLES -A fooX1234 -m iprange --src-range 192.168.1.5-192.168.1.124 -j ACCEPT; then
	IPRANGE_MATCH=Yes
	if [ -z "${KLUDGEFREE}" ]; then
	    qt $IPTABLES -A fooX1234 -m iprange --src-range 192.168.1.5-192.168.1.124 -m iprange --dst-range 192.168.1.5-192.168.1.124 -j ACCEPT && KLUDGEFREE=Yes
	fi
    fi

    qt $IPTABLES -A fooX1234 -m recent --update -j ACCEPT     && RECENT_MATCH=Yes
    qt $IPTABLES -A fooX1234 -m owner --uid-owner 0 -j ACCEPT && OWNER_MATCH=Yes

    if qt $IPTABLES -A fooX1234 -m connmark --mark 2  -j ACCEPT; then
	CONNMARK_MATCH=Yes
	qt $IPTABLES -A fooX1234 -m connmark --mark 2/0xFF -j ACCEPT && XCONNMARK_MATCH=Yes
    fi

    qt $IPTABLES -A fooX1234 -p tcp -m ipp2p --ipp2p -j ACCEPT            && IPP2P_MATCH=Yes
    qt $IPTABLES -A fooX1234 -m length --length 10:20 -j ACCEPT           && LENGTH_MATCH=Yes
    qt $IPTABLES -A fooX1234 -j REJECT --reject-with icmp-host-prohibited && ENHANCED_REJECT=Yes

    qt $IPTABLES -A fooX1234 -j ACCEPT -m comment --comment "This is a comment" && COMMENTS=Yes

    if [ -n "$MANGLE_ENABLED" ]; then
	qt $IPTABLES -t mangle -N fooX1234

	if qt $IPTABLES -t mangle -A fooX1234 -j MARK --set-mark 1; then
	    MARK=Yes
	    qt $IPTABLES -t mangle -A fooX1234 -j MARK --and-mark 0xFF && XMARK=Yes
	fi

	if qt $IPTABLES -t mangle -A fooX1234 -j CONNMARK --save-mark; then
	    CONNMARK=Yes
	    qt $IPTABLES -t mangle -A fooX1234 -j CONNMARK --save-mark --mask 0xFF && XCONNMARK=Yes
	fi

	qt $IPTABLES -t mangle -A fooX1234 -j CLASSIFY --set-class 1:1 && CLASSIFY_TARGET=Yes
	qt $IPTABLES -t mangle -F fooX1234
	qt $IPTABLES -t mangle -X fooX1234
	qt $IPTABLES -t mangle -L FORWARD -n && MANGLE_FORWARD=Yes
    fi

    qt $IPTABLES -t raw	   -L -n && RAW_TABLE=Yes

    if qt mywhich ipset; then
	qt ipset -X fooX1234 # Just in case something went wrong the last time

	if qt ipset -N fooX1234 iphash ; then
	    if qt $IPTABLES -A fooX1234 -m set --set fooX1234 src -j ACCEPT; then
		qt $IPTABLES -D fooX1234 -m set --set fooX1234 src -j ACCEPT
		IPSET_MATCH=Yes
	    fi
	    qt ipset -X fooX1234
	fi
    fi

    qt $IPTABLES -A fooX1234 -m pkttype --pkt-type broadcast -j ACCEPT && USEPKTTYPE=Yes
    qt $IPTABLES -A fooX1234 -m addrtype --src-type BROADCAST -j ACCEPT && ADDRTYPE=Yes
    qt $IPTABLES -A fooX1234 -p tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1000:1500 -j ACCEPT && TCPMSS_MATCH=Yes

    qt $IPTABLES -F fooX1234
    qt $IPTABLES -X fooX1234

    CAPVERSION=$SHOREWALL_CAPVERSION
}

report_capabilities() {
    report_capability() # $1 = Capability Description , $2 Capability Setting (if any)
    {
	local setting=

	[ "x$2" = "xYes" ] && setting="Available" || setting="Not available"

	echo "  " $1: $setting
    }

    if [ $VERBOSE -gt 1 ]; then
	echo "Shorewall has detected the following iptables/netfilter capabilities:"
	report_capability "NAT" $NAT_ENABLED
	report_capability "Packet Mangling" $MANGLE_ENABLED
	report_capability "Multi-port Match" $MULTIPORT
	[ -n "$MULTIPORT" ] && report_capability "Extended Multi-port Match" $XMULTIPORT
	report_capability "Connection Tracking Match" $CONNTRACK_MATCH
	report_capability "Packet Type Match" $USEPKTTYPE
	report_capability "Policy Match" $POLICY_MATCH
	report_capability "Physdev Match" $PHYSDEV_MATCH
	report_capability "Packet length Match" $LENGTH_MATCH
	report_capability "IP range Match" $IPRANGE_MATCH
	report_capability "Recent Match" $RECENT_MATCH
	report_capability "Owner Match" $OWNER_MATCH
	report_capability "Ipset Match" $IPSET_MATCH
	report_capability "CONNMARK Target" $CONNMARK
	[ -n "$CONNMARK" ] && report_capability "Extended CONNMARK Target" $XCONNMARK
	report_capability "Connmark Match" $CONNMARK_MATCH
	[ -n "$CONNMARK_MATCH" ] && report_capability "Extended Connmark Match" $XCONNMARK_MATCH
	report_capability "Raw Table" $RAW_TABLE
	report_capability "IPP2P Match" $IPP2P_MATCH
	report_capability "CLASSIFY Target" $CLASSIFY_TARGET
	report_capability "Extended REJECT" $ENHANCED_REJECT
	report_capability "Repeat match" $KLUDGEFREE
	report_capability "MARK Target" $MARK
	[ -n "$MARK" ] && report_capability "Extended MARK Target" $XMARK
	report_capability "Mangle FORWARD Chain" $MANGLE_FORWARD
	report_capability "Comments" $COMMENTS
	report_capability "Address Type Match" $ADDRTYPE
	report_capability "TCPMSS Match" $TCPMSS_MATCH
    fi

    [ -n "$PKTTYPE" ] || USEPKTTYPE=

}

#
# Delete IP address
#
del_ip_addr() # $1 = address, $2 = interface
{
    [ $(find_first_interface_address_if_any $2) = $1 ] || qt ip addr del $1 dev $2
}

# Add IP Aliases
#
add_ip_aliases() # $* = List of addresses
{
    local addresses external interface inet cidr rest val arping=$(mywhich arping)

    address_details()
    {
	#
	# Folks feel uneasy if they don't see all of the same
	# decoration on these IP addresses that they see when their
	# distro's net config tool adds them. In an attempt to reduce
	# the anxiety level, we have the following code which sets
	# the VLSM and BRD from an existing address in the same networks
	#
	# Get all of the lines that contain inet addresses with broadcast
	#
	ip -f inet addr show $interface 2> /dev/null | grep 'inet.*brd' | while read inet cidr rest ; do
	    case $cidr in
		*/*)
		    if in_network $external $cidr; then
			echo "/${cidr#*/} brd $(broadcastaddress $cidr)"
			break
		    fi
		    ;;
	    esac
	done
    }

    do_one()
    {
	val=$(address_details)

	ip addr add ${external}${val} dev $interface $label
	[ -n "$arping" ] && qt $arping -U -c 2 -I $interface $external
	echo "$external $interface" >> $VARDIR/nat
	[ -n "$label" ] && label="with $label"
	progress_message "   IP Address $external added to interface $interface $label"
    }

    progress_message "Adding IP Addresses..."

    while [ $# -gt 0 ]; do
	external=$1
	interface=$2
	label=

	if [ "$interface" != "${interface%:*}" ]; then
	    label="${interface#*:}"
	    interface="${interface%:*}"
	    label="label $interface:$label"
	fi

	shift 2

	list_search $external $(find_interface_addresses $interface) || do_one
    done
}

detect_gateway() # $1 = interface
{
    local interface=$1
    #
    # First assume that this is some sort of point-to-point interface
    #
    gateway=$( find_peer $(ip addr ls $interface ) )
    #
    # Maybe there's a default route through this gateway already
    #
    [ -n "$gateway" ] || gateway=$(find_gateway $(ip route ls dev $interface))
    #
    # Last hope -- is there a load-balancing route through the interface?
    #
    [ -n "$gateway" ] || gateway=$(find_nexthop $interface)
    #
    # Be sure we found one
    #
    [ -n "$gateway" ] && echo $gateway
}

#
# Disable IPV6
#
disable_ipv6() {
    local foo="$(ip -f inet6 addr ls 2> /dev/null)"

    if [ -n "$foo" ]; then
	if qt mywhich ip6tables; then
	    ip6tables -P FORWARD DROP
	    ip6tables -P INPUT DROP
	    ip6tables -P OUTPUT DROP
	    ip6tables -F
	    ip6tables -X
	    ip6tables -A OUTPUT -o lo -j ACCEPT
	    ip6tables -A INPUT -i lo -j ACCEPT
	else
	    error_message "WARNING: DISABLE_IPV6=Yes in shorewall.conf but this system does not appear to have ip6tables"
	fi
    fi
}

# 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}
}

delete_tc1()
{
    clear_one_tc() {
        tc qdisc del dev $1 root 2> /dev/null
        tc qdisc del dev $1 ingress 2> /dev/null

    }

    run_user_exit tcclear

    run_ip link list | \
    while read inx interface details; do
        case $inx in
            [0-9]*)
                clear_one_tc ${interface%:}
                ;;
            *)
                ;;
        esac
    done
}

#
# Detect a device's MTU -- echos the passed device's MTU
#
get_device_mtu() # $1 = device
{
    local output="$(ip link ls dev $1 2> /dev/null)" # quotes required for /bin/ash

    if [ -n "$output" ]; then
	echo $(find_mtu $output)
    else
	echo 1500
    fi
}

#
# Version of the above that doesn't generate any output for MTU 1500.
# Generates 'mtu <mtu+>' otherwise, where <mtu+> is the device's MTU + 100
#
get_device_mtu1() # $1 = device
{
    local output="$(ip link ls dev $1 2> /dev/null)" # quotes required for /bin/ash
    local mtu

    if [ -n "$output" ]; then
	mtu=$(find_mtu $output)
	if [ -n "$mtu" ]; then
	    [ $mtu = 1500 ] || echo mtu $(($mtu + 100))
	fi
    fi

}

#
# Undo changes to routing
#
undo_routing() {

    if [ -z "$NOROUTES"  ]; then
	#
	# Restore rt_tables database
	#
	if [ -f ${VARDIR}/rt_tables ]; then
	    cp -f ${VARDIR}/rt_tables /etc/iproute2/ && progress_message "/etc/iproute2/rt_tables database restored"
	    rm -f ${VARDIR}/rt_tables
	fi
	#
	# Restore the rest of the routing table
	#
	if [ -f ${VARDIR}/undo_routing ]; then
	    . ${VARDIR}/undo_routing
	    progress_message "Shorewall-generated routing tables and routing rules removed"
	    rm -f ${VARDIR}/undo_routing
	fi
    fi

}

restore_default_route() {
    if [ -z "$NOROUTES" -a -f ${VARDIR}/default_route ]; then
	local default_route= route

	while read route ; do
	    case $route in
		default*)
		    if [ -n "$default_route" ]; then
			case "$default_route" in
			    *metric*)
		                #
		                # Don't restore a route with a metric -- we only replace the one with metric == 0
		                #
				qt ip route delete default metric 0 && \
				    progress_message "Default Route with metric 0 deleted"
				;;
			    *)
				qt ip route replace $default_route && \
				    progress_message "Default Route (${default_route# }) restored"
				;;
			esac

			break
		    fi

		    default_route="$default_route $route"
		    ;;
		*)
		    default_route="$default_route $route"
		    ;;
	    esac
	done < ${VARDIR}/default_route

	rm -f ${VARDIR}/default_route
    fi
}

#
# Determine how to do "echo -e"
#

find_echo() {
    local result

    result=$(echo "a\tb")
    [ ${#result} -eq 3 ] && { echo echo; return; }

    result=$(echo -e "a\tb")
    [ ${#result} -eq 3 ] && { echo "echo -e"; return; }

    result=$(which echo)
    [ -n "$result" ] && { echo "$result -e"; return; }

    echo echo 
}