464xlat: don't set default firewall zone to wan

Don't set the default firewall zone to wan if not specified to keep the
behavior aligned with other tunnel protocols like gre and 6rd.
If the interface zone is not specified try to get it from the firewall config
when constructing the procd firewall rule.
While at it only add a procd inbound firewall rule if a zone is specified.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/ipv6/464xlat/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=464xlat
-PKG_VERSION:=11
+PKG_VERSION:=12
 
 PKG_SOURCE_DATE:=2018-01-16
 PKG_MAINTAINER:=Hans Dedecker <dedeckeh@gmail.com>

package/network/ipv6/464xlat/files/464xlat.sh

@@ -27,7 +27,7 @@ proto_464xlat_setup() {
 	local ip6addr ip6prefix tunlink zone
 	json_get_vars ip6addr ip6prefix tunlink zone
 
-	[ -z "$zone" ] && zone="wan"
+	[ "$zone" = "-" ] && zone=""
 
 	( proto_add_host_dependency "$cfg" "::" "$tunlink" )
 
@@ -53,25 +53,29 @@ proto_464xlat_setup() {
 	proto_add_ipv6_route $ip6addr 128 "" "" "" "" 128
 
 	proto_add_data
-	[ "$zone" != "-" ] && json_add_string zone "$zone"
+	[ -n "$zone" ] && json_add_string zone "$zone"
 
 	json_add_array firewall
+		[ -z "$zone" ] && zone=$(fw3 -q network $iface 2>/dev/null)
+
 		json_add_object ""
 			json_add_string type nat
 			json_add_string target SNAT
 			json_add_string family inet
 			json_add_string snat_ip 192.0.0.1
 		json_close_object
-		json_add_object ""
-			json_add_string type rule
-			json_add_string family inet6
-			json_add_string proto all
-			json_add_string direction in
-			json_add_string dest "$zone"
-			json_add_string src "$zone"
-			json_add_string src_ip $ip6addr
-			json_add_string target ACCEPT
-		json_close_object
+		[ -n "$zone" ] && {
+			json_add_object ""
+				json_add_string type rule
+				json_add_string family inet6
+				json_add_string proto all
+				json_add_string direction in
+				json_add_string dest "$zone"
+				json_add_string src "$zone"
+				json_add_string src_ip $ip6addr
+				json_add_string target ACCEPT
+			json_close_object
+		}
 	json_close_array
 	proto_close_data