--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_auto156/mod_auto156.lua Sat Jul 03 20:18:21 2021 +0200
@@ -0,0 +1,52 @@
+-- Synthesize XEP-0156 JSON from DNS
+local array = require "util.array";
+local encodings = require "util.encodings";
+local json = require "util.json";
+local promise = require "util.promise";
+
+local dns = require"net.adns".resolver();
+
+local function check_dns(domain)
+ return dns:lookup_promise("_xmppconnect." .. domain, "TXT");
+end
+
+local function check_domain(domain)
+ return promise.resolve(domain):next(encodings.stringprep.nameprep):next(encodings.idna.to_ascii):next(
+ function(domain_A)
+ if not domain_A then
+ return promise.reject(400);
+ else
+ return domain_A;
+ end
+ end):next(check_dns):next(function(txt)
+ local uris = array();
+ for _, cm in ipairs(txt) do
+ local kind, uri = tostring(cm.txt):match("^_xmpp%-client%-(%w+)=([hpstw]+s?://.*)");
+ if kind then
+ uris:push({rel = "urn:xmpp:alt-connections:" .. kind, href = uri});
+ end
+ end
+ if #uris == 0 then
+ return promise.reject(404);
+ end
+ return uris;
+ end);
+end
+
+module:depends("http");
+module:provides("http", {
+ route = {
+ ["GET /*"] = function(_, domain)
+ return check_domain(domain):next(function(uris)
+ return {headers = {content_type = "application/json"}, body = json.encode({links = uris})};
+ end);
+ end,
+ },
+});
+
+function module.command(args)
+ local async = require "util.async";
+ for _, domain in ipairs(args) do
+ print(assert(async.wait_for(check_domain(domain):next(json.encode))));
+ end
+end