File

plugins/mod_posix.lua @ 12642:9061f9621330

Switch to a new role-based authorization framework, removing is_admin() We began moving away from simple "is this user an admin?" permission checks before 0.12, with the introduction of mod_authz_internal and the ability to dynamically change the roles of individual users. The approach in 0.12 still had various limitations however, and apart from the introduction of roles other than "admin" and the ability to pull that info from storage, not much actually changed. This new framework shakes things up a lot, though aims to maintain the same functionality and behaviour on the surface for a default Prosody configuration. That is, if you don't take advantage of any of the new features, you shouldn't notice any change. The biggest change visible to developers is that usermanager.is_admin() (and the auth provider is_admin() method) have been removed. Gone. Completely. Permission checks should now be performed using a new module API method: module:may(action_name, context) This method accepts an action name, followed by either a JID (string) or (preferably) a table containing 'origin'/'session' and 'stanza' fields (e.g. the standard object passed to most events). It will return true if the action should be permitted, or false/nil otherwise. Modules should no longer perform permission checks based on the role name. E.g. a lot of code previously checked if the user's role was prosody:admin before permitting some action. Since many roles might now exist with similar permissions, and the permissions of prosody:admin may be redefined dynamically, it is no longer suitable to use this method for permission checks. Use module:may(). If you start an action name with ':' (recommended) then the current module's name will automatically be used as a prefix. To define a new permission, use the new module API: module:default_permission(role_name, action_name) module:default_permissions(role_name, { action_name[, action_name...] }) This grants the specified role permission to execute the named action(s) by default. This may be overridden via other mechanisms external to your module. The built-in roles that developers should use are: - prosody:user (normal user) - prosody:admin (host admin) - prosody:operator (global admin) The new prosody:operator role is intended for server-wide actions (such as shutting down Prosody). Finally, all usage of is_admin() in modules has been fixed by this commit. Some of these changes were trickier than others, but no change is expected to break existing deployments. EXCEPT: mod_auth_ldap no longer supports the ldap_admin_filter option. It's very possible nobody is using this, but if someone is then we can later update it to pull roles from LDAP somehow.
author Matthew Wild <mwild1@gmail.com>
date Wed, 15 Jun 2022 12:15:01 +0100
parent 12297:249eb306f668
child 12977:74b9e05af71e
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-- 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.
--


local want_pposix_version = "0.4.0";

local pposix = assert(require "util.pposix");
if pposix._VERSION ~= want_pposix_version then
	module:log("warn", "Unknown version (%s) of binary pposix module, expected %s."
		.. "Perhaps you need to recompile?", tostring(pposix._VERSION), want_pposix_version);
end

local have_signal, signal = pcall(require, "util.signal");
if not have_signal then
	module:log("warn", "Couldn't load signal library, won't respond to SIGTERM");
end

local lfs = require "lfs";
local stat = lfs.attributes;

local prosody = _G.prosody;

module:set_global(); -- we're a global module

local umask = module:get_option_string("umask", "027");
pposix.umask(umask);

-- Don't even think about it!
if not prosody.start_time then -- server-starting
	if pposix.getuid() == 0 and not module:get_option_boolean("run_as_root") then
		module:log("error", "Danger, Will Robinson! Prosody doesn't need to be run as root, so don't do it!");
		module:log("error", "For more information on running Prosody as root, see https://prosody.im/doc/root");
		prosody.shutdown("Refusing to run as root", 1);
	end
end

local pidfile;
local pidfile_handle;

local function remove_pidfile()
	if pidfile_handle then
		pidfile_handle:close();
		os.remove(pidfile);
		pidfile, pidfile_handle = nil, nil;
	end
end

local function write_pidfile()
	if pidfile_handle then
		remove_pidfile();
	end
	pidfile = module:get_option_path("pidfile", nil, "data");
	if pidfile then
		local err;
		local mode = stat(pidfile) and "r+" or "w+";
		pidfile_handle, err = io.open(pidfile, mode);
		if not pidfile_handle then
			module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
			prosody.shutdown("Couldn't write pidfile", 1);
		else
			if not lfs.lock(pidfile_handle, "w") then -- Exclusive lock
				local other_pid = pidfile_handle:read("*a");
				module:log("error", "Another Prosody instance seems to be running with PID %s, quitting", other_pid);
				pidfile_handle = nil;
				prosody.shutdown("Prosody already running", 1);
			else
				pidfile_handle:close();
				pidfile_handle, err = io.open(pidfile, "w+");
				if not pidfile_handle then
					module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
					prosody.shutdown("Couldn't write pidfile", 1);
				else
					if lfs.lock(pidfile_handle, "w") then
						pidfile_handle:write(tostring(pposix.getpid()));
						pidfile_handle:flush();
					end
				end
			end
		end
	end
end

local daemonize = prosody.opts.daemonize;

if daemonize == nil then
	-- Fall back to config file if not specified on command-line
	daemonize = module:get_option_boolean("daemonize", nil);
	if daemonize ~= nil then
		module:log("warn", "The 'daemonize' option has been deprecated, specify -D or -F on the command line instead.");
		-- TODO: Write some docs and include a link in the warning.
	end
end

local function remove_log_sinks()
	local lm = require "core.loggingmanager";
	lm.register_sink_type("console", nil);
	lm.register_sink_type("stdout", nil);
	lm.reload_logging();
end

if daemonize then
	local function daemonize_server()
		module:log("info", "Prosody is about to detach from the console, disabling further console output");
		remove_log_sinks();
		local ok, ret = pposix.daemonize();
		if not ok then
			module:log("error", "Failed to daemonize: %s", ret);
		elseif ret and ret > 0 then
			os.exit(0);
		else
			module:log("info", "Successfully daemonized to PID %d", pposix.getpid());
			write_pidfile();
		end
	end
	module:hook("server-started", daemonize_server)
else
	-- Not going to daemonize, so write the pid of this process
	write_pidfile();
end

module:hook("server-stopped", remove_pidfile);

-- Set signal handlers
if have_signal then
	module:add_timer(0, function ()
		signal.signal("SIGTERM", function ()
			module:log("warn", "Received SIGTERM");
			prosody.main_thread:run(function ()
				prosody.unlock_globals();
				prosody.shutdown("Received SIGTERM");
				prosody.lock_globals();
			end);
		end);

		signal.signal("SIGHUP", function ()
			module:log("info", "Received SIGHUP");
			prosody.main_thread:run(function ()
				prosody.reload_config();
			end);
			-- this also reloads logging
		end);

		signal.signal("SIGINT", function ()
			module:log("info", "Received SIGINT");
			prosody.main_thread:run(function ()
				prosody.unlock_globals();
				prosody.shutdown("Received SIGINT");
				prosody.lock_globals();
			end);
		end);

		signal.signal("SIGUSR1", function ()
			module:log("info", "Received SIGUSR1");
			module:fire_event("signal/SIGUSR1");
		end);

		signal.signal("SIGUSR2", function ()
			module:log("info", "Received SIGUSR2");
			module:fire_event("signal/SIGUSR2");
		end);
	end);
end

-- For other modules to reference
features = {
	signal_events = true;
};