File

util/logger.lua @ 12181:783056b4e448 0.11 0.11.12

util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.
author Jonas Schäfer <jonas@wielicki.name>
date Mon, 10 Jan 2022 18:23:54 +0100
parent 8556:5800f0c7afd6
child 12394:86d6b069b892
line wrap: on
line source

-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
-- luacheck: ignore 213/level

local pairs = pairs;
local ipairs = ipairs;
local require = require;

local _ENV = nil;
-- luacheck: std none

local level_sinks = {};

local make_logger;

local function init(name)
	local log_debug = make_logger(name, "debug");
	local log_info = make_logger(name, "info");
	local log_warn = make_logger(name, "warn");
	local log_error = make_logger(name, "error");

	return function (level, message, ...)
			if level == "debug" then
				return log_debug(message, ...);
			elseif level == "info" then
				return log_info(message, ...);
			elseif level == "warn" then
				return log_warn(message, ...);
			elseif level == "error" then
				return log_error(message, ...);
			end
		end
end

function make_logger(source_name, level)
	local level_handlers = level_sinks[level];
	if not level_handlers then
		level_handlers = {};
		level_sinks[level] = level_handlers;
	end

	local logger = function (message, ...)
		for i = 1,#level_handlers do
			level_handlers[i](source_name, level, message, ...);
		end
	end

	return logger;
end

local function reset()
	for level, handler_list in pairs(level_sinks) do
		-- Clear all handlers for this level
		for i = 1, #handler_list do
			handler_list[i] = nil;
		end
	end
end

local function add_level_sink(level, sink_function)
	if not level_sinks[level] then
		level_sinks[level] = { sink_function };
	else
		level_sinks[level][#level_sinks[level] + 1 ] = sink_function;
	end
end

local function add_simple_sink(simple_sink_function, levels)
	local format = require "util.format".format;
	local function sink_function(name, level, msg, ...)
		return simple_sink_function(name, level, format(msg, ...));
	end
	for _, level in ipairs(levels or {"debug", "info", "warn", "error"}) do
		add_level_sink(level, sink_function);
	end
end

return {
	init = init;
	make_logger = make_logger;
	reset = reset;
	add_level_sink = add_level_sink;
	add_simple_sink = add_simple_sink;
	new = make_logger;
};