MUC: Add per-room PM restriction functionality (thanks Wirlaburla)

Based on mod_muc_restrict_pm in prosody-modules d82c0383106a

plugins/muc/restrict_pm.lib.lua

@@ -0,0 +1,119 @@
+-- Based on code from mod_muc_restrict_pm in prosody-modules@d82c0383106a
+-- by Nicholas George <wirlaburla@worlio.com>
+
+local st = require "util.stanza";
+local muc_util = module:require "muc/util";
+local valid_roles = muc_util.valid_roles;
+
+-- COMPAT w/ prosody-modules allow_pm
+local compat_map = {
+	everyone = "visitor";
+	participants = "participant";
+	moderators = "moderator";
+	members = "affiliated";
+};
+
+local function get_allow_pm(room)
+	local val = room._data.allow_pm;
+	return compat_map[val] or val or "visitor";
+end
+
+local function set_allow_pm(room, val)
+	if get_allow_pm(room) == val then return false; end
+	room._data.allow_pm = val;
+	return true;
+end
+
+local function get_allow_modpm(room)
+	return room._data.allow_modpm or false;
+end
+
+local function set_allow_modpm(room, val)
+	if get_allow_modpm(room) == val then return false; end
+	room._data.allow_modpm = val;
+	return true;
+end
+
+module:hook("muc-config-form", function(event)
+	local pmval = get_allow_pm(event.room);
+	table.insert(event.form, {
+		name = 'muc#roomconfig_allowpm';
+		type = 'list-single';
+		label = 'Allow private messages from';
+		options = {
+			{ value = 'visitor', label = 'Everyone', default = pmval == 'visitor' };
+			{ value = 'participant', label = 'Participants', default = pmval == 'participant' };
+			{ value = 'moderator', label = 'Moderators', default = pmval == 'moderator' };
+			{ value = 'affiliated', label = "Members", default = pmval == "affiliated" };
+			{ value = 'none', label = 'No one', default = pmval == 'none' };
+		}
+	});
+	table.insert(event.form, {
+		name = '{xmpp:prosody.im}muc#allow_modpm';
+		type = 'boolean';
+		label = 'Always allow private messages to moderators';
+		value = get_allow_modpm(event.room)
+	});
+end);
+
+module:hook("muc-config-submitted/muc#roomconfig_allowpm", function(event)
+	if set_allow_pm(event.room, event.value) then
+		event.status_codes["104"] = true;
+	end
+end);
+
+module:hook("muc-config-submitted/{xmpp:prosody.im}muc#allow_modpm", function(event)
+	if set_allow_modpm(event.room, event.value) then
+		event.status_codes["104"] = true;
+	end
+end);
+
+local who_restricted = {
+	none = "in this group";
+	participant = "from guests";
+	moderator = "from non-moderators";
+	affiliated = "from non-members";
+};
+
+module:hook("muc-private-message", function(event)
+	local stanza, room = event.stanza, event.room;
+	local from_occupant = room:get_occupant_by_nick(stanza.attr.from);
+	local to_occupant = room:get_occupant_by_nick(stanza.attr.to);
+
+	-- To self is always okay
+	if to_occupant.bare_jid == from_occupant.bare_jid then return; end
+
+	if get_allow_modpm(room) then
+		if to_occupant and to_occupant.role == 'moderator'
+		or from_occupant and from_occupant.role == "moderator" then
+			return; -- Allow to/from moderators
+		end
+	end
+
+	local pmval = get_allow_pm(room);
+
+	if pmval ~= "none" then
+		if pmval == "affiliated" and room:get_affiliation(from_occupant.bare_jid) then
+			return; -- Allow from affiliated users
+		elseif valid_roles[from_occupant.role] >= valid_roles[pmval] then
+			module:log("debug", "Allowing PM: %s(%d) >= %s(%d)", from_occupant.role, valid_roles[from_occupant.role], pmval, valid_roles[pmval]);
+			return; -- Allow from a permitted role
+		end
+	end
+
+	local msg = ("Private messages are restricted %s"):format(who_restricted[pmval]);
+	module:log("debug", "Blocking PM from %s %s: %s", from_occupant.role, stanza.attr.from, msg);
+
+	room:route_to_occupant(
+		from_occupant,
+		st.error_reply(stanza, "cancel", "policy-violation", msg, room.jid)
+	);
+	return false;
+end, 1);
+
+return {
+	get_allow_pm = get_allow_pm;
+	set_allow_pm = set_allow_pm;
+	get_allow_modpm = get_allow_modpm;
+	set_allow_modpm = set_allow_modpm;
+};