ppp: propagate master firewall zone to dynamic slave interface

Assign the virtual DHCPv6 interface the firewall zone of the parent interface
so fw3 knows the zone to which the virtual DHCPv6 interface belongs.
This guarantees the firewall settings are applied correctly for the virtual
DHCPv6 interface and allows to query the zone to which the virtual DHCPv6
interface belongs via the fw3 network option.

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

package/network/services/ppp/Makefile

@@ -10,7 +10,7 @@ include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=ppp
 PKG_VERSION:=2.4.7
-PKG_RELEASE:=11
+PKG_RELEASE:=12
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://download.samba.org/pub/ppp/

package/network/services/ppp/files/lib/netifd/ppp6-up

@@ -17,10 +17,13 @@ proto_send_update "$PPP_IPPARAM"
 }
 
 if [ -n "$AUTOIPV6" ]; then
+	ZONE=$(fw3 -q network $PPP_IPPARAM 2>/dev/null)
+
 	json_init
 	json_add_string name "${PPP_IPPARAM}_6"
 	json_add_string ifname "@$PPP_IPPARAM"
 	json_add_string proto "dhcpv6"
+	[ -n "$ZONE" ] && json_add_string zone "$ZONE"
 	[ -n "$EXTENDPREFIX" ] && json_add_string extendprefix 1
 	[ -n "$IP6TABLE" ] && json_add_string ip6table $IP6TABLE
 	[ -n "$PEERDNS" ] && json_add_boolean peerdns $PEERDNS