File

util/prosodyctl/shell.lua @ 13652:a08065207ef0

net.server_epoll: Call :shutdown() on TLS sockets when supported Comment from Matthew: This fixes a potential issue where the Prosody process gets blocked on sockets waiting for them to close. Unlike non-TLS sockets, closing a TLS socket sends layer 7 data, and this can cause problems for sockets which are in the process of being cleaned up. This depends on LuaSec changes which are not yet upstream. From Martijn's original email: So first my analysis of luasec. in ssl.c the socket is put into blocking mode right before calling SSL_shutdown() inside meth_destroy(). My best guess to why this is is because meth_destroy is linked to the __close and __gc methods, which can't exactly be called multiple times and luasec does want to make sure that a tls session is shutdown as clean as possible. I can't say I disagree with this reasoning and don't want to change this behaviour. My solution to this without changing the current behaviour is to introduce a shutdown() method. I am aware that this overlaps in a conflicting way with tcp's shutdown method, but it stays close to the OpenSSL name. This method calls SSL_shutdown() in the current (non)blocking mode of the underlying socket and returns a boolean whether or not the shutdown is completed (matching SSL_shutdown()'s 0 or 1 return values), and returns the familiar ssl_ioerror() strings on error with a false for completion. This error can then be used to determine if we have wantread/wantwrite to finalize things. Once meth_shutdown() has been called once a shutdown flag will be set, which indicates to meth_destroy() that the SSL_shutdown() has been handled by the application and it shouldn't be needed to set the socket to blocking mode. I've left the SSL_shutdown() call in the LSEC_STATE_CONNECTED to prevent TOCTOU if the application reaches a timeout for the shutdown code, which might allow SSL_shutdown() to clean up anyway at the last possible moment. Another thing I've changed to luasec is the call to socket_setblocking() right before calling close(2) in socket_destroy() in usocket.c. According to the latest POSIX[0]: Note that the requirement for close() on a socket to block for up to the current linger interval is not conditional on the O_NONBLOCK setting. Which I read to mean that removing O_NONBLOCK on the socket before close doesn't impact the behaviour and only causes noise in system call tracers. I didn't touch the windows bits of this, since I don't do windows. For the prosody side of things I've made the TLS shutdown bits resemble interface:onwritable(), and put it under a combined guard of self._tls and self.conn.shutdown. The self._tls bit is there to prevent getting stuck on this condition, and self.conn.shutdown is there to prevent the code being called by instances where the patched luasec isn't deployed. The destroy() method can be called from various places and is read by me as the "we give up" error path. To accommodate for these unexpected entrypoints I've added a single call to self.conn:shutdown() to prevent the socket being put into blocking mode. I have no expectations that there is any other use here. Same as previous, the self.conn.shutdown check is there to make sure it's not called on unpatched luasec deployments and self._tls is there to make sure we don't call shutdown() on tcp sockets. I wouldn't recommend logging of the conn:shutdown() error inside close(), since a lot of clients simply close the connection before SSL_shutdown() is done.
author Martijn van Duren <martijn@openbsd.org>
date Thu, 06 Feb 2025 15:04:38 +0000
parent 13643:e5f62871e6a5
child 13732:1465b1e305df
line wrap: on
line source

local config = require "prosody.core.configmanager";
local human_io = require "prosody.util.human.io";
local server = require "prosody.net.server";
local st = require "prosody.util.stanza";
local path = require "prosody.util.paths";
local parse_args = require "prosody.util.argparse".parse;
local tc = require "prosody.util.termcolours";
local isatty = require "prosody.util.pposix".isatty;
local term_width = require"prosody.util.human.io".term_width;

local have_readline, readline = pcall(require, "readline");

local adminstream = require "prosody.util.adminstream";

if have_readline then
	readline.set_readline_name("prosody");
	readline.set_options({
			histfile = path.join(prosody.paths.data, ".shell_history");
			ignoredups = true;
		});
end

local function read_line(prompt_string)
	if have_readline then
		return readline.readline(prompt_string);
	else
		io.write(prompt_string);
		return io.read("*line");
	end
end

local function send_line(client, line)
	client.send(st.stanza("repl-input", { width = tostring(term_width()) }):text(line));
end

local function repl(client)
	local line = read_line(client.prompt_string or "prosody> ");
	if not line or line == "quit" or line == "exit" or line == "bye" then
		if not line then
			print("");
		end
		if have_readline then
			readline.save_history();
		end
		os.exit(0, true);
	end
	send_line(client, line);
end

local function printbanner()
	local banner = config.get("*", "console_banner");
	if banner then return print(banner); end
	print([[
                     ____                \   /     _
                    |  _ \ _ __ ___  ___  _-_   __| |_   _
                    | |_) | '__/ _ \/ __|/ _ \ / _` | | | |
                    |  __/| | | (_) \__ \ |_| | (_| | |_| |
                    |_|   |_|  \___/|___/\___/ \__,_|\__, |
                    A study in simplicity            |___/

]]);
	print("Welcome to the Prosody administration console. For a list of commands, type: help");
	print("You may find more help on using this console in our online documentation at ");
	print("https://prosody.im/doc/console\n");
end

local function check()
	local lfs = require "lfs";
	local socket_path = path.resolve_relative_path(prosody.paths.data, config.get("*", "admin_socket") or "prosody.sock");
	local state = lfs.attributes(socket_path, "mode");
	return state == "socket";
end

local function start(arg) --luacheck: ignore 212/arg
	local client = adminstream.client();
	local opts, err, where = parse_args(arg);
	local ttyout = isatty(io.stdout);

	if not opts then
		if err == "param-not-found" then
			print("Unknown command-line option: "..tostring(where));
		elseif err == "missing-value" then
			print("Expected a value to follow command-line option: "..where);
		end
		os.exit(1);
	end

	if arg[1] then
		if arg[2] then
			local fmt = { "%s"; ":%s("; ")" };
			for i = 3, #arg do
				if arg[i]:sub(1, 1) == ":" then
					table.insert(fmt, i, ")%s(");
				elseif i > 3 and fmt[i - 1]:match("%%q$") then
					table.insert(fmt, i, ", %q");
				else
					table.insert(fmt, i, "%q");
				end
			end
			arg[1] = string.format(table.concat(fmt), table.unpack(arg));
		end

		client.events.add_handler("connected", function()
			send_line(client, arg[1]);
			return true;
		end, 1);

		local errors = 0; -- TODO This is weird, but works for now.
		client.events.add_handler("received", function(stanza)
			if stanza.name == "repl-output" or stanza.name == "repl-result" then
				local dest = io.stdout;
				if stanza.attr.type == "error" then
					errors = errors + 1;
					dest = io.stderr;
				end
				if stanza.attr.eol == "0" then
					dest:write(stanza:get_text());
				else
					dest:write(stanza:get_text(), "\n");
				end
			end
			if stanza.name == "repl-result" then
				os.exit(errors);
			end
			return true;
		end, 1);
	end

	client.events.add_handler("connected", function ()
		if not opts.quiet then
			printbanner();
		end
		repl(client);
	end);

	client.events.add_handler("disconnected", function ()
		print("--- session closed ---");
		os.exit(0, true);
	end);

	client.events.add_handler("received", function (stanza)
		if stanza.name ~= "repl-request-input" then
			return;
		end
		if stanza.attr.type == "password" then
			local password = human_io.read_password();
			client.send(st.stanza("repl-requested-input", { type = stanza.attr.type, id = stanza.attr.id }):text(password));
		else
			io.stderr:write("Internal error - unexpected input request type "..tostring(stanza.attr.type).."\n");
			os.exit(1);
		end
		return true;
	end, 2);


	client.events.add_handler("received", function (stanza)
		if stanza.name == "repl-output" or stanza.name == "repl-result" then
			local result_prefix = stanza.attr.type == "error" and "!" or "|";
			local out = result_prefix.." "..stanza:get_text();
			if ttyout and stanza.attr.type == "error" then
				out = tc.getstring(tc.getstyle("red"), out);
			end
			print(out);
		end
		if stanza.name == "repl-result" then
			repl(client);
		end
	end);

	client.prompt_string = config.get("*", "admin_shell_prompt");

	local socket_path = path.resolve_relative_path(prosody.paths.data, opts.socket or config.get("*", "admin_socket") or "prosody.sock");
	local conn = adminstream.connection(socket_path, client.listeners);
	local ok, err = conn:connect();
	if not ok then
		if err == "no unix socket support" then
			print("** LuaSocket unix socket support not available or incompatible, ensure your");
			print("** version is up to date.");
		else
			print("** Unable to connect to server - is it running? Is mod_admin_shell enabled?");
			print("** Connection error: "..err);
		end
		os.exit(1);
	end
	server.loop();
end

return {
	shell = start;
	available = check;
};