--- a/mod_unified_push/mod_unified_push.lua	Tue Jan 10 16:05:01 2023 +0100
+++ b/mod_unified_push/mod_unified_push.lua	Tue Jan 10 15:45:03 2023 +0000
@@ -3,6 +3,7 @@
 
 local base64 = require "util.encodings".base64;
 local datetime = require "util.datetime";
+local id = require "util.id";
 local jwt_sign, jwt_verify = require "util.jwt".init("HS256", unified_push_secret);
 local st = require "util.stanza";
 local urlencode = require "util.http".urlencode;
@@ -10,6 +11,9 @@
 local xmlns_up = "http://gultsch.de/xmpp/drafts/unified-push";
 
 module:depends("http");
+module:depends("disco");
+
+module:add_feature(xmlns_up);
 
 local function check_sha256(s)
 	if not s then return nil, "no value provided"; end
@@ -31,7 +35,7 @@
 		return st.error_reply(stanza, "modify", "bad-request", "application: "..application_err);
 	end
 	local expiry = os.time() + push_registration_ttl;
-	local url = module:http_url().."/"..urlencode(jwt_sign({
+	local url = module:http_url("push").."/"..urlencode(jwt_sign({
 		instance = instance;
 		application = application;
 		sub = stanza.attr.from;
@@ -49,27 +53,34 @@
 
 -- Handle incoming POST
 function handle_push(event, subpath)
-	local data, err = jwt_verify(subpath);
-	if not data then
-		module:log("debug", "Received push to unacceptable token (%s)", err);
+	module:log("debug", "Incoming push received!");
+	local ok, data = jwt_verify(subpath);
+	if not ok then
+		module:log("debug", "Received push to unacceptable token (%s)", data);
 		return 404;
 	end
 	local payload = event.request.body;
 	if not payload or payload == "" then
+		module:log("warn", "Missing or empty push payload");
 		return 400;
 	elseif #payload > 4096 then
+		module:log("warn", "Push payload too large");
 		return 413;
 	end
-	local push_iq = st.iq({ type = "set", to = data.sub, id = event.request.id })
+	local push_id = event.request.id or id.short();
+	module:log("debug", "Push notification received [%s], relaying to device...", push_id);
+	local push_iq = st.iq({ type = "set", to = data.sub, from = module.host, id = push_id })
 		:text_tag("push", base64.encode(payload), { instance = data.instance, application = data.application, xmlns = xmlns_up });
 	return module:send_iq(push_iq):next(function ()
+		module:log("debug", "Push notification delivered [%s]", push_id);
 		return 201;
 	end, function (error_event)
 		local e_type, e_cond, e_text = error_event.stanza:get_error();
 		if e_cond == "item-not-found" or e_cond == "feature-not-implemented" then
-			module:log("debug", "Push rejected");
+			module:log("debug", "Push rejected [%s]", push_id);
 			return 404;
 		elseif e_cond == "service-unavailable" or e_cond == "recipient-unavailable" then
+			module:log("debug", "Recipient temporarily unavailable [%s]", push_id);
 			return 503;
 		end
 		module:log("warn", "Unexpected push error response: %s/%s/%s", e_type, e_cond, e_text);