gre: make encaplimit support configurable

Make inclusion of the destination option header containing the tunnel
encapsulation limit configurable for IPv6 GRE packets.
Setting the uci parameter encaplimit to ignore; allows to disable the
insertion of the destination option header in the IPv6 GRE packets.
Otherwise the tunnel encapsulation limit value can be set to a value
from 0 till 255 by setting the encaplimit uci parameter accordingly.

Signed-off-by: Hans Dedecker <[email protected]>

package/network/config/gre/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=gre
 PKG_VERSION:=1
-PKG_RELEASE:=8
+PKG_RELEASE:=9
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

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

@@ -39,6 +39,7 @@ gre_generic_setup() {
 	[ -n "$ocsum" ] && json_add_boolean ocsum "$ocsum"
 	[ -n "$iseqno" ] && json_add_boolean iseqno "$iseqno"
 	[ -n "$oseqno" ] && json_add_boolean oseqno "$oseqno"
+	[ -n "$encaplimit" ] && json_add_string encaplimit "$encaplimit"
 	json_close_object
 
 	proto_close_tunnel
@@ -133,7 +134,7 @@ grev6_setup() {
 	local remoteip6
 
 	local ip6addr peer6addr weakif
-	json_get_vars ip6addr peer6addr tunlink weakif
+	json_get_vars ip6addr peer6addr tunlink weakif encaplimit
 
 	[ -z "$peer6addr" ] && {
 		proto_notify_error "$cfg" "MISSING_PEER_ADDRESS"
@@ -274,6 +275,7 @@ proto_grev6_init_config() {
 	proto_config_add_string "ip6addr"
 	proto_config_add_string "peer6addr"
 	proto_config_add_string "weakif"
+	proto_config_add_string "encaplimit"
 }
 
 proto_grev6tap_init_config() {