map: add a legacymap option

The legacy map version based on the IPv6 Interface Identifier in
draft-ietf-softwire-map-03 was typically used by uncommenting the LEGACY
variable in the map.sh file, which is not ideal. A proper configuration
option is needed instead.

The IPv6 Interface Identifier format described in the draft was
eventually changed in RFC7597, but is still used by some major ISPs,
including in Japan.

Signed-off-by: Remi NGUYEN VAN <[email protected]>
Signed-off-by: Hans Dedecker <[email protected]> [PKG_RELEASE increase]

package/network/ipv6/map/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=map
-PKG_RELEASE:=5
+PKG_RELEASE:=6
 PKG_LICENSE:=GPL-2.0
 
 include $(INCLUDE_DIR)/package.mk

package/network/ipv6/map/files/map.sh

@@ -25,12 +25,9 @@ proto_map_setup() {
 	local iface="$2"
 	local link="map-$cfg"
 
-	# uncomment for legacy MAP0 mode
-	#export LEGACY=1
-
-	local type mtu ttl tunlink zone encaplimit
+	local type legacymap mtu ttl tunlink zone encaplimit
 	local rule ipaddr ip4prefixlen ip6prefix ip6prefixlen peeraddr ealen psidlen psid offset
-	json_get_vars type mtu ttl tunlink zone encaplimit
+	json_get_vars type legacymap mtu ttl tunlink zone encaplimit
 	json_get_vars rule ipaddr ip4prefixlen ip6prefix ip6prefixlen peeraddr ealen psidlen psid offset
 
 	[ "$zone" = "-" ] && zone=""
@@ -56,7 +53,7 @@ proto_map_setup() {
 	fi
 
 	echo "rule=$rule" > /tmp/map-$cfg.rules
-	RULE_DATA=$(mapcalc ${tunlink:-\*} $rule)
+	RULE_DATA=$(LEGACY="$legacymap" mapcalc ${tunlink:-\*} $rule)
 	if [ "$?" != 0 ]; then
 		proto_notify_error "$cfg" "INVALID_MAP_RULE"
 		proto_block_restart "$cfg"
@@ -106,7 +103,7 @@ proto_map_setup() {
 	elif [ "$type" = "map-t" -a -f "/proc/net/nat46/control" ]; then
 		proto_init_update "$link" 1
 		local style="MAP"
-		[ "$LEGACY" = 1 ] && style="MAP0"
+		[ "$legacymap" = 1 ] && style="MAP0"
 
 		echo add $link > /proc/net/nat46/control
 		local cfgstr="local.style $style local.v4 $(eval "echo \$RULE_${k}_IPV4PREFIX")/$(eval "echo \$RULE_${k}_PREFIX4LEN")"
@@ -229,6 +226,7 @@ proto_map_init_config() {
 	proto_config_add_int "psidlen"
 	proto_config_add_int "psid"
 	proto_config_add_int "offset"
+	proto_config_add_boolean "legacymap"
 
 	proto_config_add_string "tunlink"
 	proto_config_add_int "mtu"