tools.dnsregistry: For converting IANA DNS registry data to Lua table

1 files changed, 43 insertions, 0 deletions

diff --git a/tools/dnsregistry.lua b/tools/dnsregistry.lua
new file mode 100644
index 00000000..018eadb2
--- /dev/null
+++ b/tools/dnsregistry.lua
@@ -0,0 +1,43 @@
+-- Generate util/dnsregistry.lua from IANA HTTP status code registry
+local xml = require "util.xml";
+local registries = xml.parse(io.read("*a"));
+
+print("-- Source: https://www.iana.org/assignments/dns-parameters/dns-parameters.xml");
+print(os.date("-- Generated on %Y-%m-%d"))
+
+local registry_mapping = {
+	["dns-parameters-2"] = "classes";
+	["dns-parameters-4"] = "types";
+	["dns-parameters-6"] = "errors";
+};
+
+print("return {");
+for registry in registries:childtags("registry") do
+	local registry_name = registry_mapping[registry.attr.id];
+	if registry_name then
+		print("\t" .. registry_name .. " = {");
+		for record in registry:childtags("record") do
+			local record_name = record:get_child_text("name");
+			local record_type = record:get_child_text("type");
+			local record_desc = record:get_child_text("description");
+			local record_code = tonumber(record:get_child_text("value"));
+
+			if tostring(record):lower():match("reserved") or tostring(record):lower():match("reserved") then
+				record_code = nil;
+			end
+
+			if registry_name == "classes" and record_code then
+				record_type = record_desc and record_desc:match("%((%w+)%)$")
+				if record_type then
+					print(("\t\t[%q] = %d; [%d] = %q;"):format(record_type, record_code, record_code, record_type))
+				end
+			elseif registry_name == "types" and record_type and record_code then
+				print(("\t\t[%q] = %d; [%d] = %q;"):format(record_type, record_code, record_code, record_type))
+			elseif registry_name == "errors" and record_code and record_name then
+				print(("\t\t[%d] = %q; [%q] = %q;"):format(record_code, record_name, record_name, record_desc or record_name));
+			end
+		end
+		print("\t};");
+	end
+end
+print("};");