MUC: Add support for registering with a MUC, including reserving a nickname as per XEP-0045

plugins/muc/mod_muc.lua

@@ -81,6 +81,11 @@ room_mt.send_history = history.send;
 room_mt.get_historylength = history.get_length;
 room_mt.set_historylength = history.set_length;
 
+local register = module:require "muc/register";
+room_mt.get_registered_nick = register.get_registered_nick;
+room_mt.get_registered_jid = register.get_registered_jid;
+room_mt.handle_register_iq = register.handle_register_iq;
+
 local jid_split = require "util.jid".split;
 local jid_bare = require "util.jid".bare;
 local st = require "util.stanza";
@@ -401,6 +406,7 @@ for event_name, method in pairs {
 	["iq-get/bare/http://jabber.org/protocol/muc#owner:query"] = "handle_owner_query_get_to_room" ;
 	["message/bare"] = "handle_message_to_room" ;
 	["presence/bare"] = "handle_presence_to_room" ;
+	["iq/bare/jabber:iq:register:query"] = "handle_register_iq";
 	-- Host room
 	["iq-get/host/http://jabber.org/protocol/disco#info:query"] = "handle_disco_info_get_query" ;
 	["iq-get/host/http://jabber.org/protocol/disco#items:query"] = "handle_disco_items_get_query" ;

plugins/muc/register.lib.lua

@@ -0,0 +1,195 @@
+local jid_bare = require "util.jid".bare;
+local jid_resource = require "util.jid".resource;
+local resourceprep = require "util.encodings".stringprep.resourceprep;
+local st = require "util.stanza";
+local dataforms = require "util.dataforms";
+
+local allow_unaffiliated = module:get_option_boolean("allow_unaffiliated_register", false);
+
+local enforce_nick = module:get_option_boolean("enforce_registered_nickname", false);
+
+-- reserved_nicks[nick] = jid
+local function get_reserved_nicks(room)
+	if room._reserved_nicks then
+		return room._reserved_nicks;
+	end
+	module:log("debug", "Refreshing reserved nicks...");
+	local reserved_nicks = {};
+	for jid in room:each_affiliation() do
+		local data = room._affiliation_data[jid];
+		local nick = data and data.reserved_nickname;
+		module:log("debug", "Refreshed for %s: %s", jid, nick);
+		if nick then
+			reserved_nicks[nick] = jid;
+		end
+	end
+	room._reserved_nicks = reserved_nicks;
+	return reserved_nicks;
+end
+
+-- Returns the registered nick, if any, for a JID
+-- Note: this is just the *nick* part, i.e. the resource of the in-room JID
+local function get_registered_nick(room, jid)
+	local registered_data = room._affiliation_data[jid];
+	if not registered_data then
+		return;
+	end
+	return registered_data.reserved_nickname;
+end
+
+-- Returns the JID, if any, that registered a nick (not in-room JID)
+local function get_registered_jid(room, nick)
+	local reserved_nicks = get_reserved_nicks(room);
+	return reserved_nicks[nick];
+end
+
+module:hook("muc-set-affiliation", function (event)
+	-- Clear reserved nick cache
+	event.room._reserved_nicks = nil;
+end);
+
+module:add_feature("jabber:iq:register");
+
+module:hook("muc-disco#info", function (event)
+	event.reply:tag("feature", { var = "jabber:iq:register" }):up();
+end);
+
+local registration_form = dataforms.new {
+	{ name = "FORM_TYPE", type = "hidden", value = "http://jabber.org/protocol/muc#register" },
+	{ name = "muc#register_roomnick", type = "text-single", label = "Nickname"},
+};
+
+local function enforce_nick_policy(event)
+	local origin, stanza = event.origin, event.stanza;
+	local room = assert(event.room); -- FIXME
+	if not room then return; end
+
+	-- Check if the chosen nickname is reserved
+	local requested_nick = jid_resource(stanza.attr.to);
+	local reserved_by = get_registered_jid(room, requested_nick);
+	if reserved_by and reserved_by ~= jid_bare(stanza.attr.from) then
+		module:log("debug", "%s attempted to use nick %s reserved by %s", stanza.attr.from, requested_nick, reserved_by);
+		local reply = st.error_reply(stanza, "cancel", "conflict"):up();
+		origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
+		return true;
+	end
+
+	-- Check if the occupant has a reservation they must use
+	if enforce_nick then
+		local nick = get_registered_nick(room, jid_bare(stanza.attr.from));
+		if nick then
+			if event.occupant then
+				event.occupant.nick = jid_bare(event.occupant.nick) .. "/" .. nick;
+			elseif event.dest_occupant.nick ~= jid_bare(event.dest_occupant.nick) .. "/" .. nick then
+				module:log("debug", "Attempt by %s to join as %s, but their reserved nick is %s", stanza.attr.from, requested_nick, nick);
+				local reply = st.error_reply(stanza, "cancel", "not-acceptable"):up();
+				origin.send(reply:tag("x", {xmlns = "http://jabber.org/protocol/muc"}));
+				return true;
+			end
+		end
+	end
+end
+
+module:hook("muc-occupant-pre-join", enforce_nick_policy);
+module:hook("muc-occupant-pre-change", enforce_nick_policy);
+
+-- Discovering Reserved Room Nickname
+-- http://xmpp.org/extensions/xep-0045.html#reservednick
+module:hook("muc-disco#info/x-roomuser-item", function (event)
+	local nick = get_registered_nick(event.room, jid_bare(event.stanza.attr.from));
+	if nick then
+		event.reply:tag("identity", { category = "conference", type = "text", name = nick })
+	end
+end);
+
+local function handle_register_iq(room, origin, stanza)
+	local user_jid = jid_bare(stanza.attr.from)
+	local affiliation = room:get_affiliation(user_jid);
+	if affiliation == "outcast" then
+		origin.send(st.error_reply(stanza, "auth", "forbidden"));
+		return true;
+	elseif not (affiliation or allow_unaffiliated) then
+		origin.send(st.error_reply(stanza, "auth", "registration-required"));
+		return true;
+	end
+	local reply = st.reply(stanza);
+	local registered_nick = get_registered_nick(room, user_jid);
+	if stanza.attr.type == "get" then
+		reply:query("jabber:iq:register");
+		if registered_nick then
+			reply:tag("registered"):up();
+			reply:tag("username"):text(registered_nick);
+			origin.send(reply);
+			return true;
+		end
+		reply:add_child(registration_form:form());
+	else -- type == set -- handle registration form
+		local query = stanza.tags[1];
+		if query:get_child("remove") then
+			-- Remove "member" affiliation, but preserve if any other
+			local new_affiliation = affiliation ~= "member" and affiliation;
+			local ok, err_type, err_condition = room:set_affiliation(true, user_jid, new_affiliation, nil, false);
+			if not ok then
+				origin.send(st.error_reply(stanza, err_type, err_condition));
+				return true;
+			end
+			origin.send(reply);
+			return true;
+		end
+		local form_tag = query:get_child("x", "jabber:x:data");
+		local reg_data = form_tag and registration_form:data(form_tag);
+		if not reg_data then
+			origin.send(st.error_reply(stanza, "modify", "bad-request", "Error in form"));
+			return true;
+		end
+		-- Is the nickname valid?
+		local desired_nick = resourceprep(reg_data["muc#register_roomnick"]);
+		if not desired_nick then
+			origin.send(st.error_reply(stanza, "modify", "bad-request", "Invalid Nickname"));
+			return true;
+		end
+		-- Is the nickname currently in use by another user?
+		local current_occupant = room:get_occupant_by_nick(room.jid.."/"..desired_nick);
+		if current_occupant and current_occupant.bare_jid ~= user_jid then
+			origin.send(st.error_reply(stanza, "cancel", "conflict"));
+			return true;
+		end
+		-- Is the nickname currently reserved by another user?
+		local reserved_by = get_registered_jid(room, desired_nick);
+		if reserved_by and reserved_by ~= user_jid then
+			origin.send(st.error_reply(stanza, "cancel", "conflict"));
+			return true;
+		end
+
+		-- Kick any sessions that are not using this nick before we register it
+		if enforce_nick then
+			local required_room_nick = room.jid.."/"..desired_nick;
+			for room_nick, occupant in room:each_occupant() do
+				if occupant.bare_jid == user_jid and room_nick ~= required_room_nick then
+					room:set_role(true, room_nick, nil); -- Kick (TODO: would be nice to use 333 code)
+				end
+			end
+		end
+
+		-- Checks passed, save the registration
+		if registered_nick ~= desired_nick then
+			local registration_data = { reserved_nickname = desired_nick };
+			local ok, err_type, err_condition = room:set_affiliation(true, user_jid, "member", nil, registration_data);
+			if not ok then
+				origin.send(st.error_reply(stanza, err_type, err_condition));
+				return true;
+			end
+			module:log("debug", "Saved nick registration for %s: %s", user_jid, desired_nick);
+			origin.send(reply);
+			return true;
+		end
+	end
+	origin.send(reply);
+	return true;
+end
+
+return {
+	get_registered_nick = get_registered_nick;
+	get_registered_jid = get_registered_jid;
+	handle_register_iq = handle_register_iq;
+}