#!/bin/sh
#
# Shorewall 4.1 -- /usr/share/shorewall/lib.providers
#
#     This program is under GPL [http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt]
#
#     (c) 1999,2000,2001,2002,2003,2004,2005,2006,2007 - 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.
#
# This library is loaded by /usr/share/shorewall/compiler when the providers file is
# non-empty.
#

#
# Process the providers file
#
setup_providers()
{
    local table
    local number
    local mark
    local duplicate
    local interface
    local gateway
    local options
    local provider
    local address
    local copy
    local route
    local loose
    local addresses
    local rulenum
    local rulebase
    local balance
    local save_indent
    save_indent="$INDENT"
    local mask
    mask=
    local first
    first=Yes
    local save_indent1
    save_indent1=

    copy_table() {
	    indent >&3 << __EOF__
ip route show table $duplicate | while read net route; do
    case \$net in
        default|nexthop)
            ;;
        *)
            run_ip route add table $number \$net \$route
            ;;
    esac
done
__EOF__
    }

    copy_and_edit_table() {
	indent >&3 << __EOF__
ip route show table $duplicate | while read net route; do
    case \$net in
        default|nexthop)
            ;;
        *)
            case \$(find_device \$route) in
                `echo $copy\) | sed 's/ /|/g'`
                    run_ip route add table $number \$net \$route
                    ;;
            esac
            ;;
    esac
done

__EOF__
    }

    balance_default_route() # $1 = weight
    {
	balance=yes

	save_command
	if [ -n "$first" ]; then
	    if [ -n "$gateway" ] ; then
		save_command "DEFAULT_ROUTE=\"nexthop via $gateway dev $interface weight $1\""
	    else
		save_command "DEFAULT_ROUTE=\"nexthop dev $interface weight $1\""
	    fi

	    first=
	else
	    if [ -n "$gateway" ] ; then
		save_command "DEFAULT_ROUTE=\"\$DEFAULT_ROUTE nexthop via $gateway dev $interface weight $1\""
	    else
		save_command "DEFAULT_ROUTE=\"\$DEFAULT_ROUTE nexthop dev $interface weight $1\""
	    fi
	fi
    }

    add_a_provider() {
	local t
	local n
	local iface
	local option
	local optional
	optional=

	[ -n "$MANGLE_ENABLED" ] || fatal_error "Providers require mangle support in your kernel and iptables"

	for t in $PROVIDERS local main default unspec; do
	    if [ "$t" = "$table" ]; then
		fatal_error "Duplicate Provider: $table, provider: \"$provider\""
	    fi

	    eval n=\$${t}_number
	    #
	    # The following is because the %$#@ shell doesn't accept hex numbers in '-eq' tests
	    #
	    if [ $(($n)) -eq $(($number)) ]; then
		fatal_error "Duplicate Provider number: $number, provider: \"$provider\""
	    fi
	done

	eval ${table}_number=$number

	indent >&3 << __EOF__
#
# Add Provider $table ($number)
#
__EOF__
	save_command "if interface_is_usable $interface; then"
	save_indent1="$INDENT"
	INDENT="$INDENT    "

	iface=$(chain_base $interface)

	save_command "${iface}_up=Yes"

	save_command "qt ip route flush table $number"

	indent >&3 << __EOF__
echo "qt ip route flush table $number" >> \${VARDIR}/undo_routing
__EOF__

	if [ "x${duplicate:=-}" != x- ]; then
	    if [ "x${copy:=-}" != "x-" ]; then
		if [ "x${copy}" = xnone ]; then
		    copy=$interface
		else
		    copy="$interface $(separate_list $copy)"
		fi
		copy_and_edit_table
	    else
		copy_table
	    fi
	elif [ "x${copy:=-}" != x- ]; then
	    fatal_error "A non-empty COPY column requires that a routing table be specified in the DUPLICATE column" 
	fi

	if [ "x$gateway" = xdetect ] ; then
	    gateway='$gateway'
	    indent >&3 << __EOF__
gateway=\$(detect_gateway $interface)

if [ -n "\$gateway" ]; then
    run_ip route replace \$gateway src \$(find_first_interface_address $interface) dev $interface table $number
    run_ip route add default via \$gateway dev $interface table $number
else
    fatal_error "Unable to detect the gateway through interface $interface"
fi

__EOF__
	elif [ "x$gateway" != "x-" -a -n "$gateway" ]; then
	    indent >&3 << __EOF__
run_ip route replace $gateway src \$(find_first_interface_address $interface) dev $interface table $number
run_ip route add default via $gateway dev $interface table $number
__EOF__
	else
	    gateway=
	    save_command "run_ip route add default dev $interface table $number"
	fi

	if [ x${mark} != x- ]; then
	    verify_mark $mark

	    if [ $(($mark)) -lt 256 ]; then
		if [ -n "$HIGH_ROUTE_MARKS" ]; then
		    fatal_error "Invalid Mark Value ($mark) with HIGH_ROUTE_MARKS=Yes"
		fi
	    elif [ -z "$HIGH_ROUTE_MARKS" ]; then
		fatal_error "Invalid Mark Value ($mark) with HIGH_ROUTE_MARKS=No"
	    fi

	    eval ${table}_mark=$mark

	    [ -n "$DELETE_THEN_ADD" ] && qt ip rule del fwmark $mark
	    indent >&3 << __EOF__
run_ip rule add fwmark $mark pref $((10000 + $mark)) table $number
echo "qt ip rule del fwmark $mark" >> \${VARDIR}/undo_routing
__EOF__
	fi

	loose=

	for option in $(separate_list $options); do
	    case $option in
		-)
		    ;;
		track)
		    list_search $interface $ROUTEMARK_INTERFACES && \
			fatal_error "Interface $interface is tracked through an earlier provider"
		    [ x${mark} = x- ] && fatal_error "The 'track' option requires a numeric value in the MARK column - Provider \"$provider\""
		    eval ${iface}_routemark=$mark
		    ROUTEMARK_INTERFACES="$ROUTEMARK_INTERFACES $interface"
		    ;;
		balance=*)
		    balance_default_route ${option#*=}
		    ;;
		balance)
		    balance_default_route 1
		    ;;
		loose)
		    loose=Yes
		    ;;
		optional)
		    optional=Yes
		    ;;
		*)
		    error_message "WARNING: Invalid option ($option) ignored in provider \"$provider\""
		    ;;
	    esac
	done

	rulenum=0

	if [ -z "$loose" ]; then
	    rulebase=$(( 20000 + ( 256 * ($number-1) ) ))
	    indent >&3 << __EOF__

rulenum=0

find_interface_addresses $interface | while read address; do
__EOF__

	    [ -n "$DELETE_THEN_ADD" ] && save_command "    qt ip rule del from \$address"

	    indent >&3 << __EOF__
    run_ip rule add from \$address pref \$(( $rulebase + \$rulenum )) table $number
    echo "qt ip rule del from \$address" >> \${VARDIR}/undo_routing
    rulenum=\$((\$rulenum + 1))
done
__EOF__
	elif [ -n "$DELETE_THEN_ADD" ]; then
	    indent >&3 << __EOF__

find_interface_addresses $interface | while read address; do
    qt ip rule del from \$address
done
__EOF__
	    [ -n "$balance" ] && error_message "WARNING: 'balance' and 'loose' should not be specified together - Provider \"$provider\""
	fi
     

    indent >&3 << __EOF__

progress_message "   Provider $table ($number) Added"

__EOF__

    INDENT="$save_indent1"
    save_command else

    if [ -n "$optional" ]; then
	save_command "    error_message \"WARNING: Interface $interface is not configured -- Provider $table ($number) not Added\""
	save_command "    ${iface}_up="
    else
	save_command "    fatal_error \"ERROR: Interface $interface is not configured -- Provider $table ($number) Cannot be Added\""
    fi

    save_command fi
    save_command

    }

    verify_provider()
    {
	local p
	local n

	for p in $PROVIDERS main; do
	    [ "$p" = "$1" ] && return 0
	    eval n=\$${p}_number
	    [ "$n" = "$1" ] && return 0
	done

	fatal_error "Unknown provider $1 in route rule \"$rule\""
    }

    add_an_rtrule()
    {
	verify_provider $provider

	[ "x$source"   = x- ] && source=
	[ "x$dest"     = x- ] && dest= || dest="to $dest"

	[ -n "${source}${dest}" ] || fatal_error "You must specify either the source or destination in an rt rule: \"$rule\""

	[ -n "${dest:=to 0.0.0.0/0}" ]

	if [ -n "$source" ]; then
	    case $source in
		*:*)
		    source="iif ${source%:*} from ${source#*:}"
		    ;;
		*.*.*)
		    source="from $source"
		    ;;
		*)
		    source="iif $source"
		    ;;
	    esac
	else
	    source='from 0.0.0.0/0'
	fi

	case "$priority" in
	    [0-9][0-9][0-9][0-9]|[0-9][0-9][0-9][0-9][0-9])
		;;
	    *)
		fatal_error "Invalid priority ($priority) in rule \"$rule\""
		;;
	esac

	priority="priority $priority"

	[ -n "$DELETE_THEN_ADD" ] && save_command "qt ip rule del $source $dest $priority"
	save_command "run_ip rule add $source $dest $priority table $provider"
	indent >&3 << __EOF__
echo "qt ip rule del $source $dest $priority" >> \${VARDIR}/undo_routing
__EOF__
	progress_message "Routing rule \"$rule\" $DONE"
    }
    #
    #  E x e c u t i o n    B e g i n s    H e r e
    #
    local_number=255
    main_number=254
    default_number=253
    unspec_number=0
    balance=

    progress_message2 "$DOING $1..."
    save_command
    save_command "if [ -z \"\$NOROUTES\" ]; then"
    INDENT="$INDENT    "
    indent >&3 << __EOF__
#
# Undo any changes made since the last time that we [re]started -- this will not restore the default route
#
undo_routing
#
# Save current routing table database so that it can be restored later
#
cp /etc/iproute2/rt_tables \${VARDIR}/
#
# Capture the default route(s) if we don't have it (them) already.
#
[ -f \${VARDIR}/default_route ] || ip route list | grep -E '^\s*(default |nexthop )' > \${VARDIR}/default_route
#
# Initialize the file that holds 'undo' commands
#
> \${VARDIR}/undo_routing
__EOF__
    save_progress_message "Adding Providers..."
    save_command "DEFAULT_ROUTE="

    while read table number mark duplicate interface gateway options copy; do
	provider="$table $number $mark $duplicate $interface $gateway $options $copy"
	add_a_provider
	PROVIDERS="$PROVIDERS $table"
	progress_message "Provider $provider $DONE"
    done < $TMP_DIR/providers

    if [ -n "$PROVIDERS" ]; then
	if [ -n "$balance" ]; then
	    save_command "if [ -n \"\$DEFAULT_ROUTE\" ]; then"
	    save_command "    run_ip route replace default scope global \$DEFAULT_ROUTE"
	    save_command "    progress_message \"Default route '\$(echo \$DEFAULT_ROUTE | sed 's/\$\\s*//')' Added\""
	    save_command "else"
	    save_command "    error_message \"WARNING: No Default route added (all 'balance' providers are down)\""
	    save_command "    restore_default_route"
	    save_command "fi"
	    save_command
	else
	    save_command "#"
	    save_command "# We don't have any 'balance' providers so we retore any default route that we've saved"
	    save_command "#"
	    save_command restore_default_route
	fi

	save_command "if [ -w /etc/iproute2/rt_tables ]; then"
	
	cat >&3 << __EOF__
${INDENT}    cat > /etc/iproute2/rt_tables <<EOF
#
# reserved values
#
255     local
254     main
253     default
0       unspec
#
# local
#
EOF

${INDENT}    echocommand=\$(find_echo)
__EOF__
        for table in $PROVIDERS; do
	    eval number=\$${table}_number
	    indent >&3 << __EOF__
    \$echocommand "$number\t$table" >>  /etc/iproute2/rt_tables
__EOF__
	done

	save_command "fi"
	save_command

	if [ -s $TMP_DIR/route_rules ]; then
	    progress_message2 "$DOING $(find_file route_rules)..."

	    save_command

	    while read source dest provider priority; do
		rule="$source $dest $priority $provider"
		add_an_rtrule
	    done < $TMP_DIR/route_rules
	fi
    fi

    save_command
    save_command "run_ip route flush cache"
    INDENT="$save_indent"
    save_command "fi"
    save_command
}

#
# Set up Route marking (Only called if $ROUTEMARK_INTERFACES is non-empty)
#
setup_route_marking()
{
    local mask
    mask=0xFF
    local save_indent
    save_indent="$INDENT"

    [ -n "$HIGH_ROUTE_MARKS" ] && mask=0xFF00

    run_iptables -t mangle -A PREROUTING -m connmark ! --mark 0/$mask -j CONNMARK --restore-mark --mask $mask
    run_iptables -t mangle -A OUTPUT     -m connmark ! --mark 0/$mask -j CONNMARK --restore-mark --mask $mask
    createmanglechain routemark

    for interface in $ROUTEMARK_INTERFACES ; do
	iface=$(chain_base $interface)
	eval mark_value=\$${iface}_routemark

	save_command
	save_command "if [ -n \"\$${iface}_up\" ]; then"
	INDENT="$INDENT    "
	run_iptables -t mangle -A PREROUTING -i $interface -m mark --mark 0/$mask -j routemark
	run_iptables -t mangle -A routemark  -i $interface                        -j MARK --set-mark $mark_value
	INDENT="$save_indent"
	save_command "fi"
    done

    save_command

    run_iptables -t mangle -A routemark -m mark ! --mark 0/$mask -j CONNMARK --save-mark --mask $mask

}