openwrt/package/firewall/files/lib/core_interface.sh

# Copyright (C) 2009-2010 OpenWrt.org

fw_configure_interface() {
	local iface=$1
	local action=$2
	local ifname=$3
	local aliasnet=$4

	[ "$action" == "add" ] && {
		local status=$(uci_get_state network "$iface" up 0)
		[ "$status" == 1 ] || [ -n "$aliasnet" ] || return 0
	}

	[ -n "$ifname" ] || ifname=$(uci_get_state network "$iface" ifname "$iface")
	[ "$ifname" == "lo" ] && return 0

	fw_callback pre interface

	fw__do_rules() {
		local action=$1
		local zone=$2
		local chain=zone_${zone}
		local ifname=$3
		local subnet=$4

		local inet onet
		local mode=$(fw_get_family_mode x $zone i)

		case "$mode/$subnet" in
			# Zone supports v6 only or dual, need v6
			6/*:*|i/*:*)
				inet="{ -s $subnet -d ::/0 }"
				onet="{ -s ::/0 -d $subnet }"
				mode=6
			;;

			# Zone supports v4 only or dual, need v4
			4/*.*.*.*|i/*.*.*.*)
				inet="{ -s $subnet -d 0.0.0.0/0 }"
				onet="{ -s 0.0.0.0/0 -d $subnet }"
				mode=4
			;;

			# Need v6 while zone is v4
			*/*:*) fw_log info "zone $zone does not support IPv6 address family, skipping"; return ;;

			# Need v4 while zone is v6
			*/*.*) fw_log info "zone $zone does not support IPv4 address family, skipping"; return ;;
		esac

		fw $action $mode f ${chain}_ACCEPT ACCEPT ^ $onet { -o "$ifname" }
		fw $action $mode f ${chain}_ACCEPT ACCEPT ^ $inet { -i "$ifname" }
		fw $action $mode f ${chain}_DROP   DROP   ^ $onet { -o "$ifname" }
		fw $action $mode f ${chain}_DROP   DROP   ^ $inet { -i "$ifname" }
		fw $action $mode f ${chain}_REJECT reject ^ $onet { -o "$ifname" }
		fw $action $mode f ${chain}_REJECT reject ^ $inet { -i "$ifname" }

		fw $action $mode n ${chain}_nat MASQUERADE ^ $onet { -o "$ifname" }
		fw $action $mode f ${chain}_MSSFIX TCPMSS  ^ $onet { -o "$ifname" -p tcp --tcp-flags SYN,RST SYN --clamp-mss-to-pmtu }

		fw $action $mode f input   ${chain}         $ $inet { -i "$ifname" }
		fw $action $mode f forward ${chain}_forward $ $inet { -i "$ifname" }
		fw $action $mode n PREROUTING ${chain}_prerouting ^ $inet { -i "$ifname" }
		fw $action $mode r PREROUTING ${chain}_notrack    ^ $inet { -i "$ifname" }
	}

	local old_zones old_ifname old_subnet
	config_get old_zones core "${iface}_zone"
	[ -n "$old_zones" ] && {
		config_get old_ifname core "${iface}_ifname"
		config_get old_subnet core "${iface}_subnet"

		local z
		for z in $old_zones; do
			fw_log info "removing $iface ($old_ifname${old_subnet:+ alias $old_subnet}) from zone $z"
			fw__do_rules del $z $old_ifname $old_subnet

			[ -n "$old_subnet" ] || ACTION=remove ZONE="$z" INTERFACE="$iface" DEVICE="$ifname" /sbin/hotplug-call firewall
		done

		local old_aliases
		config_get old_aliases core "${iface}_aliases"

		local a
		for a in $old_aliases; do
			fw_configure_interface "$a" del "$old_ifname"
		done

		uci_revert_state firewall core "${iface}_zone"
		uci_revert_state firewall core "${iface}_ifname"
		uci_revert_state firewall core "${iface}_subnet"
		uci_revert_state firewall core "${iface}_aliases"
	}

	[ "$action" == del ] && return

	local new_zones=
	load_zone() {
		fw_config_get_zone "$1"
		list_contains zone_network "$iface" || return

		fw_log info "adding $iface ($ifname${aliasnet:+ alias $aliasnet}) to zone $zone_name"
		fw__do_rules add ${zone_name} "$ifname" $aliasnet
		append new_zones $zone_name

		[ -n "$aliasnet" ] || ACTION=add ZONE="$zone_name" INTERFACE="$iface" DEVICE="$ifname" /sbin/hotplug-call firewall
	}
	config_foreach load_zone zone

	[ -z "$aliasnet" ] && {
		local aliases
		config_get aliases "$iface" aliases

		local a
		for a in $aliases; do
			local ipaddr netmask ip6addr
			config_get ipaddr "$a" ipaddr
			config_get netmask "$a" netmask
			config_get ip6addr "$a" ip6addr

			[ -n "$ipaddr" ] && fw_configure_interface "$a" add "$ifname" "$ipaddr${netmask:+/$netmask}"
			[ -n "$ip6addr" ] && fw_configure_interface "$a" add "$ifname" "$ip6addr"
		done

		fw_sysctl_interface $ifname
		fw_callback post interface

		uci_set_state firewall core "${iface}_aliases" "$aliases"
	}

	uci_set_state firewall core "${iface}_zone" "$new_zones"
	uci_set_state firewall core "${iface}_ifname" "$ifname"
	uci_set_state firewall core "${iface}_subnet" "$aliasnet"
}

fw_sysctl_interface() {
	local ifname=$1
	{
		sysctl -w net.ipv4.conf.${ifname}.accept_redirects=$FW_ACCEPT_REDIRECTS
		sysctl -w net.ipv6.conf.${ifname}.accept_redirects=$FW_ACCEPT_REDIRECTS
		sysctl -w net.ipv4.conf.${ifname}.accept_source_route=$FW_ACCEPT_SRC_ROUTE
		sysctl -w net.ipv6.conf.${ifname}.accept_source_route=$FW_ACCEPT_SRC_ROUTE
	} >/dev/null 2>/dev/null
}