gre: add ipv6 parameter to gre interfaces

IPv6 protocol is enabled on all gre interfaces, but gre(v6)tap
interfaces are usually added to a bridge interface, in which case
IPv6 should be enabled only on the bridge interface.

Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com> [PKG_RELEASE increase]

package/network/config/gre/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=gre
 PKG_VERSION:=1
-PKG_RELEASE:=11
+PKG_RELEASE:=12
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

package/network/config/gre/files/gre.sh

@@ -13,8 +13,8 @@ gre_generic_setup() {
 	local local="$3"
 	local remote="$4"
 	local link="$5"
-	local mtu ttl tos zone ikey okey icsum ocsum iseqno oseqno multicast
-	json_get_vars mtu ttl tos zone ikey okey icsum ocsum iseqno oseqno multicast
+	local mtu ipv6 ttl tos zone ikey okey icsum ocsum iseqno oseqno multicast
+	json_get_vars mtu ipv6 ttl tos zone ikey okey icsum ocsum iseqno oseqno multicast
 
 	[ -z "$multicast" ] && multicast=1
 
@@ -23,6 +23,7 @@ gre_generic_setup() {
 	proto_add_tunnel
 	json_add_string mode "$mode"
 	json_add_int mtu "${mtu:-1280}"
+	json_add_boolean ipv6 "${ipv6:-1}"
 	[ -n "$df" ] && json_add_boolean df "$df"
 	[ -n "$ttl" ] && json_add_int ttl "$ttl"
 	[ -n "$tos" ] && json_add_string tos "$tos"
@@ -248,6 +249,7 @@ gre_generic_init_config() {
 	available=1
 
 	proto_config_add_int "mtu"
+	proto_config_add_boolean "ipv6"
 	proto_config_add_int "ttl"
 	proto_config_add_string "tos"
 	proto_config_add_string "tunlink"