odhcp6c: make ds-lite/map tunnel encapsulation limit support configurable (FS#1501)

Be compatible with ISPs which don't support the destination option header containing
the tunnel encapsulation limit as reported in FS#1501 for dynamic created ds-lite/map
interfaces.
Setting the uci parameter encaplimit_dslite/map to ignore; allows to disable the insertion
of the destination option header for the dynamic created ds-lite/map interface.
Otherwise the tunnel encapsulation limit value can be set to a value from 0 till 255
by setting the encaplimit_dslite/map uci parameter accordingly.

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

package/network/ipv6/odhcp6c/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=odhcp6c
-PKG_RELEASE:=11
+PKG_RELEASE:=12
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/odhcp6c.git

package/network/ipv6/odhcp6c/files/dhcpv6.script

@@ -170,6 +170,7 @@ setup_interface () {
 		json_add_string tunlink "$INTERFACE"
 		[ -n "$ZONE_MAP" ] || ZONE_MAP=$ZONE
 		[ -n "$ZONE_MAP" ] && json_add_string zone "$ZONE_MAP"
+		[ -n "$ENCAPLIMIT_MAP" ] && json_add_string encaplimit "$ENCAPLIMIT_MAP"
 		[ -n "$IFACE_MAP_DELEGATE" ] && json_add_boolean delegate "$IFACE_MAP_DELEGATE"
 		json_close_object
 		ubus call network add_dynamic "$(json_dump)"
@@ -183,6 +184,7 @@ setup_interface () {
 		json_add_string tunlink "$INTERFACE"
 		[ -n "$ZONE_DSLITE" ] || ZONE_DSLITE=$ZONE
 		[ -n "$ZONE_DSLITE" ] && json_add_string zone "$ZONE_DSLITE"
+		[ -n "$ENCAPLIMIT_DSLITE" ] && json_add_string encaplimit "$ENCAPLIMIT_DSLITE"
 		[ -n "$IFACE_DSLITE_DELEGATE" ] && json_add_boolean delegate "$IFACE_DSLITE_DELEGATE"
 		json_close_object
 		ubus call network add_dynamic "$(json_dump)"

package/network/ipv6/odhcp6c/files/dhcpv6.sh

@@ -19,8 +19,10 @@ proto_dhcpv6_init_config() {
 	proto_config_add_array 'ip6prefix:list(ip6addr)'
 	proto_config_add_string iface_dslite
 	proto_config_add_string zone_dslite
+	proto_config_add_string encaplimit_dslite
 	proto_config_add_string iface_map
 	proto_config_add_string zone_map
+	proto_config_add_string encaplimit_map
 	proto_config_add_string iface_464xlat
 	proto_config_add_string zone_464xlat
 	proto_config_add_string zone
@@ -48,8 +50,8 @@ proto_dhcpv6_setup() {
 	local config="$1"
 	local iface="$2"
 
-	local reqaddress reqprefix clientid reqopts defaultreqopts noslaaconly forceprefix extendprefix norelease ip6prefix ip6prefixes iface_dslite iface_map iface_464xlat ifaceid userclass vendorclass sendopts delegate zone_dslite zone_map zone_464xlat zone soltimeout fakeroutes sourcefilter keep_ra_dnslifetime ra_holdoff
-	json_get_vars reqaddress reqprefix clientid reqopts defaultreqopts noslaaconly forceprefix extendprefix norelease iface_dslite iface_map iface_464xlat ifaceid userclass vendorclass delegate zone_dslite zone_map zone_464xlat zone soltimeout fakeroutes sourcefilter keep_ra_dnslifetime ra_holdoff
+	local reqaddress reqprefix clientid reqopts defaultreqopts noslaaconly forceprefix extendprefix norelease ip6prefix ip6prefixes iface_dslite iface_map iface_464xlat ifaceid userclass vendorclass sendopts delegate zone_dslite zone_map zone_464xlat zone encaplimit_dslite encaplimit_map soltimeout fakeroutes sourcefilter keep_ra_dnslifetime ra_holdoff
+	json_get_vars reqaddress reqprefix clientid reqopts defaultreqopts noslaaconly forceprefix extendprefix norelease iface_dslite iface_map iface_464xlat ifaceid userclass vendorclass delegate zone_dslite zone_map zone_464xlat zone encaplimit_dslite encaplimit_map soltimeout fakeroutes sourcefilter keep_ra_dnslifetime ra_holdoff
 	json_for_each_item proto_dhcpv6_add_prefix ip6prefix ip6prefixes
 
 	# Configure
@@ -98,6 +100,8 @@ proto_dhcpv6_setup() {
 	[ -n "$zone_map" ] && proto_export "ZONE_MAP=$zone_map"
 	[ -n "$zone_464xlat" ] && proto_export "ZONE_464XLAT=$zone_464xlat"
 	[ -n "$zone" ] && proto_export "ZONE=$zone"
+	[ -n "$encaplimit_dslite" ] && proto_export "ENCAPLIMIT_DSLITE=$encaplimit_dslite"
+	[ -n "$encaplimit_map" ] && proto_export "ENCAPLIMIT_MAP=$encaplimit_map"
 	[ "$fakeroutes" != "0" ] && proto_export "FAKE_ROUTES=1"
 	[ "$sourcefilter" = "0" ] && proto_export "NOSOURCEFILTER=1"
 	[ "$extendprefix" = "1" ] && proto_export "EXTENDPREFIX=1"