#     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.header6
################################################################################
#
# Get all interface addresses with VLSMs
#

find_interface_full_addresses() # $1 = interface
{
    $IP -f inet6 addr show $1 2> /dev/null | grep 'inet6 ' | sed 's/\s*inet6 //;s/ scope.*//;s/ peer.*//'
}

#
# Normalize an IPv6 Address by compressing out consecutive zero elements
#
normalize_address() # $1 = valid IPv6 Address
{
    local address
    address=$1
    local j

    while true; do
	case $address in
	    ::*)
		address=0$address
		;;
	    *::*)
		list_count $(split $address)

		j=$?

		if [ $j -eq 7 ]; then
		    address=${address%::*}:0:${address#*::}
		elif [ $j -eq 8 ]; then
		    $address=${address%::*}:${address#*::}
		    break 2
		else
		    address=${address%::*}:0::${address#*::}
		fi
		;;
	    *)
		echo $address
		break 2
		;;
	esac
    done
}

#
# Reads correctly-formed and fully-qualified host and subnet addresses from STDIN. For each
# that defines a /120 or larger network, it sends to STDOUT:
#
#    The corresponding subnet-router anycast address (all host address bits are zero)
#    The corresponding anycast addresses defined by RFC 2526 (the last 128 addresses in the subnet)
#
convert_to_anycast() {
    local address
    local badress
    local vlsm
    local host
    local o
    local m
    m=
    local z
    z=65535
    local l

    while read address; do
	case $address in
	    2*|3*)
		vlsm=${address#*/}
		vlsm=${vlsm:=128}

		if [ $vlsm -le 120 ]; then
	            #
	            # Defines a viable subnet -- first get the subnet-router anycast address
	            #
		    host=$((128 - $vlsm))

		    address=$(normalize_address ${address%/*})

		    while [ $host -ge 16 ]; do
			address=${address%:*}
			host=$(($host - 16))
		    done

		    if [ $host -gt 0 ]; then
			#
			# VLSM is not a multiple of 16
			#
			host=$((16 - $host))
			o=$((0x${address##*:}))
			m=0
			while [ $host -gt 0 ]; do
			    m=$((($m >> 1) | 0x8000))
			    z=$(($z >> 1))
			    host=$(($host - 1))
			done

			o=$(($o & $m))

			badress=${address%:*}

			address=$badress:$(printf %04x $o)

			z=$(($o | $z))

			if [ $vlsm -gt 112 ]; then
			    z=$(($z & 0xff80))
			fi

			badress=$badress:$(printf %04x $z)
		    else
			badress=$address
		    fi
		    #
		    # Note: at this point $address and $badress are the same except possibly for
		    #       the contents of the last half-word
		    #
		    list_count $(split $address)

		    l=$?
		    #
		    # Now generate the anycast addresses defined by RFC 2526
		    #
		    if [ $l -lt 8 ]; then
			#
			# The subnet-router address
			#
			echo $address::

		    	while [ $l -lt 8 ]; do
			    badress=$badress:ffff
			    l=$(($l + 1 ))
			done
		    else
			#
			# The subnet-router address
			#
			echo $address
		    fi
		    #
		    # And the RFC 2526 addresses
		    #
		    echo $badress/121
		fi
		;;
	esac
    done
}

#
# Generate a list of anycast addresses for a given interface
#

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

    find_interface_full_addresses $1 | convert_to_anycast | sort -u
}

#
# Get a list of all configured anycast addresses on the system
#
get_all_acasts()
{
    find_interface_full_addresses | convert_to_anycast | sort -u
}

#
# Detect the gateway through an interface
#
detect_gateway() # $1 = interface
{
    local interface
    interface=$1
    #
    # First assume that this is some sort of point-to-point interface
    #
    gateway=$( find_peer $($IP -6 addr list $interface ) )
    #
    # Maybe there's a default route through this gateway already
    #
    [ -n "$gateway" ] || gateway=$(find_gateway $($IP -6 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
}

#
# Add an additional gateway to the default route
#
add_gateway() # $1 = Delta $2 = Table Number
{
    local route
    local weight
    local delta
    local dev
    
    run_ip route add default scope global table $2 $1
}

#
# 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 -6 -o route ls table $2 | grep ^default | sed 's/[\]//g'`
    gateway=$1
  
    dev=$(find_device $route)
    [ "$dev" = "$3" ] && run_ip route delete default table $2
}

#
# 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
}

#
# Clear Proxy NDP
#
delete_proxyndp() {
    if [ -f ${VARDIR}/proxyndp ]; then
	while read address interface external haveroute; do
	    qt $IP -6 neigh del proxy $address dev $external
	    [ -z "${haveroute}${g_noroutes}" ] && qt $IP -6 route del $address/128 dev $interface
	    f=/proc/sys/net/ipv6/conf/$interface/proxy_ndp
	    [ -f $f ] && echo 0 > $f
	done < ${VARDIR}/proxyndp

	rm -f ${VARDIR}/proxyndp
    fi
}

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

    setpolicy INPUT ACCEPT
    setpolicy FORWARD ACCEPT
    setpolicy OUTPUT ACCEPT

    run_iptables -F
    qt $IP6TABLES -t raw -F

    echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

    run_clear_exit

    set_state "Cleared"

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

#
# Run the .iptables_restore_input as a set of discrete iptables commands
#
debug_restore_input() {
    local first second rest table chain
    #
    # Clear the ruleset
    #
    qt1 $IP6TABLES -t mangle -F
    qt1 $IP6TABLES -t mangle -X

    for chain in PREROUTING INPUT FORWARD POSTROUTING; do
	qt1 $IP6TABLES -t mangle -P $chain ACCEPT
    done

    qt1 $IP6TABLES -t raw    -F
    qt1 $IP6TABLES -t raw    -X

    for chain in PREROUTING OUTPUT; do
	qt1 $IP6TABLES -t raw -P $chain ACCEPT
    done

    qt1 $IP6TABLES -t filter -F
    qt1 $IP6TABLES -t filter -X

    for chain in INPUT FORWARD OUTPUT; do
	qt1 $IP6TABLES -t filter -P $chain -P ACCEPT
    done

    while read first second rest; do
	case $first in
	    -*)
		#
		# We can't call run_iptables() here because the rules may contain quoted strings
		#
		eval $IP6TABLES -t $table $first $second $rest

		if [ $? -ne 0 ]; then
		    error_message "ERROR: Command \"$IP6TABLES $first $second $rest\" Failed"
		    stop_firewall
		    exit 2
		fi
		;;
	    :*)
		chain=${first#:}

		if [ "x$second" = x- ]; then
		    do_iptables -t $table -N $chain
		else
		    do_iptables -t $table -P $chain $second
		fi

		if [ $? -ne 0 ]; then
		    error_message "ERROR: Command \"$IP6TABLES $first $second $rest\" Failed"
		    stop_firewall
		    exit 2
		fi
		;;
	    #
	    # This grotesque hack with the table names works around a bug/feature with ash
	    #
	    '*'raw)
		table=raw
		;;
	    '*'rawpost)
		table=rawpost
		;;
	    '*'mangle)
		table=mangle
		;;
	    '*'nat)
		table=nat
		;;
	    '*'filter)
		table=filter
		;;
	esac
    done
}

################################################################################
# End of functions imported from /usr/share/shorewall/prog.header6
################################################################################