shorewall_code/Shorewall/Perl/prog.header

#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 1999-2011 - Tom Eastep (teastep@shorewall.net)
#
#	Options are:
#
#	    -n				  Don't alter Routing
#	    -v and -q			  Standard Shorewall Verbosity control
#           -t                            Timestamp progress messages
#           -p                            Purge conntrack table
#           -r                            Recover from failed start/restart
#           -V <verbosity>                Set verbosity level explicitly
#           -R <restore>                  Overrides RESTOREFILE setting
#
#	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
#
################################################################################
# Functions imported from /usr/share/shorewall/prog.header
################################################################################
#
# Find the value 'weight' in the passed arguments then echo the next value
#

find_weight() {
    while [ $# -gt 1 ]; do
	[ "x$1" = xweight ] && 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 -4 route list | 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
}

#
# Echo the name of the interface(s) that will be used to send to the
# passed address
#

find_interface_by_address() {
    local dev
    dev="$(find_rt_interface $1)"
    local first
    local rest

    [ -z "$dev" ] && dev=$(find_default_interface)

    [ -n "$dev" ] && echo $dev
}

#
#  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 -4 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 the broadcast addresses associated with an interface
#
get_interface_bcasts() # $1 = interface
{
    local addresses
    addresses=

    $IP -f inet addr show dev $1 2> /dev/null | grep 'inet.*brd' | sed 's/inet.*brd //; s/scope.*//;' | sort -u
}

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

# Add IP Aliases
#
add_ip_aliases() # $* = List of addresses
{
    local local
    local addresses
    local external
    local interface
    local inet
    local cidr
    local rest
    local val
    local arping
    arping=$(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 the gateway through a PPP or DHCP-configured interface
#
detect_dynamic_gateway() { # $1 = interface
    local interface
    interface=$1
    local GATEWAYS
    GATEWAYS=
    local gateway

    gateway=$(run_findgw_exit $1);

    if [ -z "$gateway" ]; then
	gateway=$( find_peer $($IP addr list $interface ) )
    fi

    if [ -z "$gateway" -a -f /var/lib/dhcpcd/dhcpcd-${1}.info ]; then
	eval $(grep ^GATEWAYS=  /var/lib/dhcpcd/dhcpcd-${1}.info 2> /dev/null)
	[ -n "$GATEWAYS" ] && GATEWAYS=${GATEWAYS%,*} && gateway=$GATEWAYS
    fi

    if [ -z "$gateway" -a -f /var/lib/dhcp/dhclient-${1}.lease ]; then
	gateway=$(grep 'option routers' /var/lib/dhcp/dhclient-${1}.lease | tail -n 1 | while read j1 j2 gateway; do echo $gateway ; return 0; done)
    fi

    [ -n "$gateway" ] && echo $gateway
}

#
# Detect the gateway through an interface
#
detect_gateway() # $1 = interface
{
    local interface
    interface=$1
    local gateway
    #
    # First assume that this is some sort of dynamic interface
    #
    gateway=$( detect_dynamic_gateway $interface )
    #
    # Maybe there's a default route through this gateway already
    #
    [ -n "$gateway" ] || gateway=$(find_gateway $($IP -4 route list dev $interface | grep ^default))
    #
    # Last hope -- is there a load-balancing route through the interface?
    #
    [ -n "$gateway" ] || gateway=$(find_nexthop $interface)
    #
    # Be sure we found one
    #
    [ -n "$gateway" ] && echo $gateway
}

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

    if [ -n "$foo" ]; then
	if [ -x "$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
}

#
# Add an additional gateway to the default route
#
add_gateway() # $1 = Delta $2 = Table Number
{
    local route
    local weight
    local delta
    local dev
    
    route=`$IP -4 -o route ls table $2 | grep ^default | sed 's/default //; s/[\]//g'`

    if [ -z "$route" ]; then
	run_ip route add default scope global table $2 $1
    else
	delta=$1

	if ! echo $route | fgrep -q ' nexthop '; then
	    route=`echo $route | sed 's/via/nexthop via/'`
	    dev=$(find_device $route)
	    if [ -f ${VARDIR}/${dev}_weight ]; then
		weight=`cat ${VARDIR}/${dev}_weight`
		route="$route weight $weight"
	    fi
	fi

	run_ip route replace default scope global table $2 $route $delta
    fi
}

#
# Remove a gateway from the default route
#
delete_gateway() # $! = Description of the Gateway $2 = table number $3 = device
{
    local route
    local gateway
    local dev

    route=`$IP -4 -o route ls table $2 | grep ^default | sed 's/[\]//g'`
    gateway=$1
  
    if [ -n "$route" ]; then
	if echo $route | fgrep -q ' nexthop '; then
	    gateway="nexthop $gateway"
	    eval route=\`echo $route \| sed \'s/$gateway/ /\'\`
	    run_ip route replace table $2 $route
	else
	    dev=$(find_device $route)
	    [ "$dev" = "$3" ] && run_ip route delete default table $2
	fi
    fi
}

#
# Determine the MAC address of the passed IP through the passed interface
#
find_mac() # $1 = IP address, $2 = interface
{
    if interface_is_usable $2 ; then
	qt ping -nc 1 -t 2 -I $2 $1

	local result
	result=$($IP neigh list |  awk "/^$1 / {print \$5}")

	case $result in
	    \<*\>)
		;;
	    *)
		[ -n "$result" ] && echo $result
		;;
	esac
    fi
}

#
# Clear Proxy Arp
#
delete_proxyarp() {
    if [ -f ${VARDIR}/proxyarp ]; then
	while read address interface external haveroute; do
	    qtnoin $IP -4 neigh del proxy $address dev $external
	    [ -z "${haveroute}${g_noroutes}" ] && qtnoin $IP -4 route del $address/32 dev $interface
	    f=/proc/sys/net/ipv4/conf/$interface/proxy_arp
	    [ -f $f ] && echo 0 > $f
	done < ${VARDIR}/proxyarp

	rm -f ${VARDIR}/proxyarp
    fi
}

#
# Remove all Shorewall-added rules
#
clear_firewall() {
    stop_firewall

    setpolicy INPUT ACCEPT
    setpolicy FORWARD ACCEPT
    setpolicy OUTPUT ACCEPT

    run_iptables -F
    qt $IPTABLES -t raw -F

    echo 1 > /proc/sys/net/ipv4/ip_forward

    if [ -n "$DISABLE_IPV6" ]; then
	if [ -x $IP6TABLES ]; then
    	    $IP6TABLES -P INPUT   ACCEPT 2> /dev/null
	    $IP6TABLES -P OUTPUT  ACCEPT 2> /dev/null
	    $IP6TABLES -P FORWARD ACCEPT 2> /dev/null
	fi
    fi

    run_clear_exit

    set_state "Cleared"

    logger -p kern.info "$g_product Cleared"
}

#
# Get a list of all configured broadcast addresses on the system
#
get_all_bcasts()
{
    $IP -f inet addr show 2> /dev/null | grep 'inet.*brd' | grep -v '/32 ' | sed 's/inet.*brd //; s/scope.*//;' | sort -u
}

################################################################################
# End of functions in /usr/share/shorewall/prog.header
################################################################################