File

mod_srvinjection/mod_srvinjection.lua @ 6254:b6e390a97c85

mod_dnsupdate: Improve handling of existing DNS records Previously it would print the final service denial record when the current DNS setup matched the config and no changes were necessary.
author Kim Alvefur <zash@zash.se>
date Mon, 12 May 2025 12:15:10 +0200
parent 1592:47fb4f36dacd
line wrap: on
line source


module:set_global();

local adns = require "net.adns";

local map_config = module:get_option("srvinjection") or {};
local map = module:shared "s2s_map"

for host, mapping in pairs(map_config) do
	if type(mapping) == "table" and type(mapping[1]) == "string" and (type(mapping[2]) == "number") then
		local connecthost, connectport = mapping[1], mapping[2] or 5269;
		map[host] = {{
			srv = {
				target = connecthost..".";
				port = connectport;
				priority = 1;
				weight = 0;
			};
		}};
	else
		module:log("warn", "Ignoring invalid SRV injection for host '%s'", host);
		map[host] = nil;
	end
end

local original_lookup = adns.lookup;
function adns.lookup(handler, qname, qtype, qclass)
	if qtype == "SRV" then
		local host = qname:match("^_xmpp%-server%._tcp%.(.*)%.$");
		local mapping = map[host] or map["*"];
		if mapping then
			handler(mapping);
			return;
		end
	elseif qtype == "A" then
		if (qname == "localhost." or qname == "127.0.0.1.") then
			handler({{ a = "127.0.0.1" }});
			return;
		end
		local ip = qname:match("^(%d+.%d+.%d+.%d+).$");
		if ip then
			handler({{ a = ip }});
			return;
		end
	end
	return original_lookup(handler, qname, qtype, qclass);
end

function module.unload()
	adns.lookup = original_lookup;
end