File

mod_dnsupdate/mod_dnsupdate.lua @ 4764:a754f7e380b2

mod_dnsupdate: Rewrite port config vs DNS comparison code I'm not sure if it was correct, which means it was hard to understand and thus needed to be simplified. Hope this accomplishes that.
author Kim Alvefur <zash@zash.se>
date Mon, 08 Nov 2021 23:03:14 +0100
parent 4763:91077c928c57
child 4765:3632836f35b0
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module:set_global();

local config = require "core.configmanager";
local argparse = require "util.argparse";
local dns = require"net.adns".resolver();
local async = require "util.async";
local set = require "util.set";
local nameprep = require"util.encodings".stringprep.nameprep;
local idna_to_ascii = require"util.encodings".idna.to_ascii;

local services = { "xmpp-client"; "xmpps-client"; "xmpp-server"; "xmpps-server" }

local function validate_dnsname_option(options, option_name, default)
	local host = options[option_name];
	if host == nil then return default end
	local normalized = nameprep(host);
	if not normalized then
		module:log("error", "--%s %q fails normalization");
		return;
	end
	local alabel = idna_to_ascii(normalized);
	if not alabel then
		module:log("error", "--%s %q fails IDNA");
		return;
	end
	return alabel;
end

function module.command(arg)
	local opts = argparse.parse(arg, {
		short_params = { d = "domain"; p = "primary"; t = "target"; l = "ttl"; h = "help"; ["?"] = "help" };
		value_params = { domain = true; primary = true; target = true; ttl = true };
	});

	if not arg[1] or arg[2] or not opts or opts.help or not opts.domain then
		local out = opts.help and io.stdout or io.stderr;
		out:write("prosodyctl mod_dnsupdate [options] virtualhost\n");
		out:write("\t-d --domain\tbase domain name *required*\n");
		out:write("\t-p --primary\tprimary DNS name server\n");
		out:write("\t-t --target\ttarget hostname for SRV\n");
		out:write("\t-l --ttl\tTTL to use\n");
		out:write("\t--each\tremove and replace individual SRV records\n");
		out:write("\t--reset\tremove and replace all SRV records\n");
		return opts and opts.help and 0 or 1;
	end

	local vhost = nameprep(arg[1]); -- TODO loop over arg[]?
	if not vhost then
		module:log("error", "Host %q fails normalization", arg[1]);
		return 1;
	end
	local ihost = idna_to_ascii(vhost);
	if not ihost then
		module:log("error", "Host %q falis IDNA", vhost);
		return 1;
	end
	if not config.get(vhost, "defined") then
		module:log("error", "Host %q is not defined in the config", vhost);
		return 1;
	end

	local domain = validate_dnsname_option(opts, "domain");
	if not domain then
		module:log("error", "--domain is required");
		return 1;
	end
	local primary = validate_dnsname_option(opts, "primary")
		or async.wait_for(dns:lookup_promise(domain, "SOA"):next(function(ret) return ret[1].soa.mname; end));
	if not primary then
		module:log("error", "Could not discover primary name server, specify it with --primary");
		return 1;
	end
	local target = validate_dnsname_option(opts, "target", module:context(vhost):get_option_string("xmpp_host", ihost));
	-- TODO validate that target has A/AAAA

	local configured_ports = {
		["xmpp-client"] = module:get_option_array("c2s_ports", { 5222 });
		["xmpp-server"] = module:get_option_array("s2s_ports", { 5269 });
		["xmpps-client"] = module:get_option_array("c2s_direct_tls_ports", {});
		["xmpps-server"] = module:get_option_array("s2s_direct_tls_ports", {});
	};

	if opts.multiplex then
		for opt, ports in pairs(configured_ports) do
			ports:append(module:get_option_array(opt:sub(1, 5) == "xmpps" and "ssl_ports" or "ports", {}));
		end
	end

	local existing_srv = {};
	for _, service in ipairs(services) do
		existing_srv[service] = dns:lookup_promise(("_%s._tcp.%s"):format(service, ihost), "SRV");
	end

	print("zone", domain);
	print("server", primary);
	print("ttl " .. tostring(opts.ttl or 60 * 60));

	for _, service in ipairs(services) do
		local ports = set.new(configured_ports[service]);
		local records = (async.wait_for(existing_srv[service]));
		if opts.reset then
			print(("del _%s._tcp.%s IN SRV"):format(service, ihost));
		else
			for _, rr in ipairs(records) do
				if ports:contains(rr.srv.port) and target == nameprep(rr.srv.target):gsub("%.$", "") then
					ports:remove(rr.srv.port)
				else
					print(("del _%s._tcp.%s IN SRV %s"):format(service, ihost, rr));
				end
			end
		end
		for port in ports do print(("add _%s._tcp.%s IN SRV 1 1 %d %s"):format(service, ihost, port, target)); end
	end

	print("show");
	print("send");
	print("answer");
end