Diff

plugins/mod_admin_shell.lua @ 10856:c99711eda0d1

mod_admin_shell: New module that implements the console interface over an admin socket
author Matthew Wild <mwild1@gmail.com>
date Mon, 01 Jun 2020 15:43:00 +0100
child 10859:8de0057b4279
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/mod_admin_shell.lua	Mon Jun 01 15:43:00 2020 +0100
@@ -0,0 +1,1637 @@
+-- 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 212/self
+
+module:set_global();
+module:depends("admin_socket");
+
+local hostmanager = require "core.hostmanager";
+local modulemanager = require "core.modulemanager";
+local s2smanager = require "core.s2smanager";
+local portmanager = require "core.portmanager";
+local helpers = require "util.helpers";
+local server = require "net.server";
+local st = require "util.stanza";
+
+local _G = _G;
+
+local prosody = _G.prosody;
+
+local unpack = table.unpack or unpack; -- luacheck: ignore 113
+local iterators = require "util.iterators";
+local keys, values = iterators.keys, iterators.values;
+local jid_bare, jid_split, jid_join = import("util.jid", "bare", "prepped_split", "join");
+local set, array = require "util.set", require "util.array";
+local cert_verify_identity = require "util.x509".verify_identity;
+local envload = require "util.envload".envload;
+local envloadfile = require "util.envload".envloadfile;
+local has_pposix, pposix = pcall(require, "util.pposix");
+local async = require "util.async";
+local serialization = require "util.serialization";
+local serialize_config = serialization.new ({ fatal = false, unquoted = true});
+local time = require "util.time";
+
+local commands = module:shared("commands")
+local def_env = module:shared("env");
+local default_env_mt = { __index = def_env };
+
+local function redirect_output(target, session)
+	local env = setmetatable({ print = session.print }, { __index = function (_, k) return rawget(target, k); end });
+	env.dofile = function(name)
+		local f, err = envloadfile(name, env);
+		if not f then return f, err; end
+		return f();
+	end;
+	return env;
+end
+
+console = {};
+
+local runner_callbacks = {};
+
+function runner_callbacks:error(err)
+	module:log("error", "Traceback[shell]: %s", err);
+
+	self.data.print("Fatal error while running command, it did not complete");
+	self.data.print("Error: "..tostring(err));
+end
+
+local function send_repl_result(session, line)
+	return session.send(st.stanza("repl-result"):text(tostring(line)));
+end
+
+function console:new_session(admin_session)
+	local session = {
+			send = function (t)
+				return send_repl_result(admin_session, t);
+			end;
+			print = function (...)
+				local t = {};
+				for i=1,select("#", ...) do
+					t[i] = tostring(select(i, ...));
+				end
+				return send_repl_result(admin_session, table.concat(t, "\t"));
+			end;
+			serialize = tostring;
+			disconnect = function () admin_session:close(); end;
+			};
+	session.env = setmetatable({}, default_env_mt);
+
+	session.thread = async.runner(function (line)
+		console:process_line(session, line);
+	end, runner_callbacks, session);
+
+	-- Load up environment with helper objects
+	for name, t in pairs(def_env) do
+		if type(t) == "table" then
+			session.env[name] = setmetatable({ session = session }, { __index = t });
+		end
+	end
+
+	session.env.output:configure();
+
+	return session;
+end
+
+local function handle_line(event)
+	local session = event.origin.shell_session;
+	if not session then
+		session = console:new_session(event.origin);
+		event.origin.shell_session = session;
+	end
+	local line = event.stanza:get_text();
+	local useglobalenv;
+
+
+		module:log("debug", "HELLO: %s", line)
+	if line:match("^>") then
+		line = line:gsub("^>", "");
+		useglobalenv = true;
+	else
+		local command = line:match("^%w+") or line:match("%p");
+		if commands[command] then
+			commands[command](session, line);
+			return;
+		end
+	end
+
+	session.env._ = line;
+
+	if not useglobalenv and commands[line:lower()] then
+		commands[line:lower()](session, line);
+		return;
+	end
+
+	local chunkname = "=console";
+	local env = (useglobalenv and redirect_output(_G, session)) or session.env or nil
+	-- luacheck: ignore 311/err
+	local chunk, err = envload("return "..line, chunkname, env);
+	if not chunk then
+		chunk, err = envload(line, chunkname, env);
+		if not chunk then
+			err = err:gsub("^%[string .-%]:%d+: ", "");
+			err = err:gsub("^:%d+: ", "");
+			err = err:gsub("'<eof>'", "the end of the line");
+			session.print("Sorry, I couldn't understand that... "..err);
+			return;
+		end
+	end
+
+	local taskok, message = chunk();
+
+	if not message then
+		if type(taskok) ~= "string" and useglobalenv then
+			taskok = session.serialize(taskok);
+		end
+		session.print("Result: "..tostring(taskok));
+		return;
+	elseif (not taskok) and message then
+		session.print("Command completed with a problem");
+		session.print("Message: "..tostring(message));
+		return;
+	end
+
+	session.print("OK: "..tostring(message));
+end
+
+module:hook("admin/repl-line", function (event)
+	local ok, err = pcall(handle_line, event);
+	if not ok then
+		event.origin.send(st.stanza("repl-result", { type = "error" }):text(err));
+	end
+end);
+
+-- Console commands --
+-- These are simple commands, not valid standalone in Lua
+
+function commands.help(session, data)
+	local print = session.print;
+	local section = data:match("^help (%w+)");
+	if not section then
+		print [[Commands are divided into multiple sections. For help on a particular section, ]]
+		print [[type: help SECTION (for example, 'help c2s'). Sections are: ]]
+		print [[]]
+		print [[c2s - Commands to manage local client-to-server sessions]]
+		print [[s2s - Commands to manage sessions between this server and others]]
+		print [[http - Commands to inspect HTTP services]] -- XXX plural but there is only one so far
+		print [[module - Commands to load/reload/unload modules/plugins]]
+		print [[host - Commands to activate, deactivate and list virtual hosts]]
+		print [[user - Commands to create and delete users, and change their passwords]]
+		print [[server - Uptime, version, shutting down, etc.]]
+		print [[port - Commands to manage ports the server is listening on]]
+		print [[dns - Commands to manage and inspect the internal DNS resolver]]
+		print [[xmpp - Commands for sending XMPP stanzas]]
+		print [[debug - Commands for debugging the server]]
+		print [[config - Reloading the configuration, etc.]]
+		print [[console - Help regarding the console itself]]
+	elseif section == "c2s" then
+		print [[c2s:show(jid) - Show all client sessions with the specified JID (or all if no JID given)]]
+		print [[c2s:show_insecure() - Show all unencrypted client connections]]
+		print [[c2s:show_secure() - Show all encrypted client connections]]
+		print [[c2s:show_tls() - Show TLS cipher info for encrypted sessions]]
+		print [[c2s:count() - Count sessions without listing them]]
+		print [[c2s:close(jid) - Close all sessions for the specified JID]]
+		print [[c2s:closeall() - Close all active c2s connections ]]
+	elseif section == "s2s" then
+		print [[s2s:show(domain) - Show all s2s connections for the given domain (or all if no domain given)]]
+		print [[s2s:show_tls(domain) - Show TLS cipher info for encrypted sessions]]
+		print [[s2s:close(from, to) - Close a connection from one domain to another]]
+		print [[s2s:closeall(host) - Close all the incoming/outgoing s2s sessions to specified host]]
+	elseif section == "http" then
+		print [[http:list(hosts) - Show HTTP endpoints]]
+	elseif section == "module" then
+		print [[module:load(module, host) - Load the specified module on the specified host (or all hosts if none given)]]
+		print [[module:reload(module, host) - The same, but unloads and loads the module (saving state if the module supports it)]]
+		print [[module:unload(module, host) - The same, but just unloads the module from memory]]
+		print [[module:list(host) - List the modules loaded on the specified host]]
+	elseif section == "host" then
+		print [[host:activate(hostname) - Activates the specified host]]
+		print [[host:deactivate(hostname) - Disconnects all clients on this host and deactivates]]
+		print [[host:list() - List the currently-activated hosts]]
+	elseif section == "user" then
+		print [[user:create(jid, password) - Create the specified user account]]
+		print [[user:password(jid, password) - Set the password for the specified user account]]
+		print [[user:delete(jid) - Permanently remove the specified user account]]
+		print [[user:list(hostname, pattern) - List users on the specified host, optionally filtering with a pattern]]
+	elseif section == "server" then
+		print [[server:version() - Show the server's version number]]
+		print [[server:uptime() - Show how long the server has been running]]
+		print [[server:memory() - Show details about the server's memory usage]]
+		print [[server:shutdown(reason) - Shut down the server, with an optional reason to be broadcast to all connections]]
+	elseif section == "port" then
+		print [[port:list() - Lists all network ports prosody currently listens on]]
+		print [[port:close(port, interface) - Close a port]]
+	elseif section == "dns" then
+		print [[dns:lookup(name, type, class) - Do a DNS lookup]]
+		print [[dns:addnameserver(nameserver) - Add a nameserver to the list]]
+		print [[dns:setnameserver(nameserver) - Replace the list of name servers with the supplied one]]
+		print [[dns:purge() - Clear the DNS cache]]
+		print [[dns:cache() - Show cached records]]
+	elseif section == "xmpp" then
+		print [[xmpp:ping(localhost, remotehost) -- Sends a ping to a remote XMPP server and reports the response]]
+	elseif section == "config" then
+		print [[config:reload() - Reload the server configuration. Modules may need to be reloaded for changes to take effect.]]
+		print [[config:get([host,] option) - Show the value of a config option.]]
+	elseif section == "stats" then -- luacheck: ignore 542
+		-- TODO describe how stats:show() works
+	elseif section == "debug" then
+		print [[debug:logevents(host) - Enable logging of fired events on host]]
+		print [[debug:events(host, event) - Show registered event handlers]]
+		print [[debug:timers() - Show information about scheduled timers]]
+	elseif section == "console" then
+		print [[Hey! Welcome to Prosody's admin console.]]
+		print [[First thing, if you're ever wondering how to get out, simply type 'quit'.]]
+		print [[Secondly, note that we don't support the full telnet protocol yet (it's coming)]]
+		print [[so you may have trouble using the arrow keys, etc. depending on your system.]]
+		print [[]]
+		print [[For now we offer a couple of handy shortcuts:]]
+		print [[!! - Repeat the last command]]
+		print [[!old!new! - repeat the last command, but with 'old' replaced by 'new']]
+		print [[]]
+		print [[For those well-versed in Prosody's internals, or taking instruction from those who are,]]
+		print [[you can prefix a command with > to escape the console sandbox, and access everything in]]
+		print [[the running server. Great fun, but be careful not to break anything :)]]
+	end
+	print [[]]
+end
+
+-- Session environment --
+-- Anything in def_env will be accessible within the session as a global variable
+
+--luacheck: ignore 212/self
+local serialize_defaults = module:get_option("console_prettyprint_settings", { fatal = false, unquoted = true, maxdepth = 2})
+
+def_env.output = {};
+function def_env.output:configure(opts)
+	if type(opts) ~= "table" then
+		opts = { preset = opts };
+	end
+	if not opts.fallback then
+		-- XXX Error message passed to fallback is lost, does it matter?
+		opts.fallback = tostring;
+	end
+	for k,v in pairs(serialize_defaults) do
+		if opts[k] == nil then
+			opts[k] = v;
+		end
+	end
+	self.session.serialize = serialization.new(opts);
+end
+
+def_env.server = {};
+
+function def_env.server:insane_reload()
+	prosody.unlock_globals();
+	dofile "prosody"
+	prosody = _G.prosody;
+	return true, "Server reloaded";
+end
+
+function def_env.server:version()
+	return true, tostring(prosody.version or "unknown");
+end
+
+function def_env.server:uptime()
+	local t = os.time()-prosody.start_time;
+	local seconds = t%60;
+	t = (t - seconds)/60;
+	local minutes = t%60;
+	t = (t - minutes)/60;
+	local hours = t%24;
+	t = (t - hours)/24;
+	local days = t;
+	return true, string.format("This server has been running for %d day%s, %d hour%s and %d minute%s (since %s)",
+		days, (days ~= 1 and "s") or "", hours, (hours ~= 1 and "s") or "",
+		minutes, (minutes ~= 1 and "s") or "", os.date("%c", prosody.start_time));
+end
+
+function def_env.server:shutdown(reason)
+	prosody.shutdown(reason);
+	return true, "Shutdown initiated";
+end
+
+local function human(kb)
+	local unit = "K";
+	if kb > 1024 then
+		kb, unit = kb/1024, "M";
+	end
+	return ("%0.2f%sB"):format(kb, unit);
+end
+
+function def_env.server:memory()
+	if not has_pposix or not pposix.meminfo then
+		return true, "Lua is using "..human(collectgarbage("count"));
+	end
+	local mem, lua_mem = pposix.meminfo(), collectgarbage("count");
+	local print = self.session.print;
+	print("Process: "..human((mem.allocated+mem.allocated_mmap)/1024));
+	print("   Used: "..human(mem.used/1024).." ("..human(lua_mem).." by Lua)");
+	print("   Free: "..human(mem.unused/1024).." ("..human(mem.returnable/1024).." returnable)");
+	return true, "OK";
+end
+
+def_env.module = {};
+
+local function get_hosts_set(hosts)
+	if type(hosts) == "table" then
+		if hosts[1] then
+			return set.new(hosts);
+		elseif hosts._items then
+			return hosts;
+		end
+	elseif type(hosts) == "string" then
+		return set.new { hosts };
+	elseif hosts == nil then
+		return set.new(array.collect(keys(prosody.hosts)));
+	end
+end
+
+-- Hosts with a module or all virtualhosts if no module given
+-- matching modules_enabled in the global section
+local function get_hosts_with_module(hosts, module)
+	local hosts_set = get_hosts_set(hosts)
+	/ function (host)
+			if module then
+				-- Module given, filter in hosts with this module loaded
+				if modulemanager.is_loaded(host, module) then
+					return host;
+				else
+					return nil;
+				end
+			end
+			if not hosts then
+				-- No hosts given, filter in VirtualHosts
+				if prosody.hosts[host].type == "local" then
+					return host;
+				else
+					return nil
+				end
+			end;
+			-- No module given, but hosts are, don't filter at all
+			return host;
+		end;
+	if module and modulemanager.get_module("*", module) then
+		hosts_set:add("*");
+	end
+	return hosts_set;
+end
+
+function def_env.module:load(name, hosts, config)
+	hosts = get_hosts_with_module(hosts);
+
+	-- Load the module for each host
+	local ok, err, count, mod = true, nil, 0;
+	for host in hosts do
+		if (not modulemanager.is_loaded(host, name)) then
+			mod, err = modulemanager.load(host, name, config);
+			if not mod then
+				ok = false;
+				if err == "global-module-already-loaded" then
+					if count > 0 then
+						ok, err, count = true, nil, 1;
+					end
+					break;
+				end
+				self.session.print(err or "Unknown error loading module");
+			else
+				count = count + 1;
+				self.session.print("Loaded for "..mod.module.host);
+			end
+		end
+	end
+
+	return ok, (ok and "Module loaded onto "..count.." host"..(count ~= 1 and "s" or "")) or ("Last error: "..tostring(err));
+end
+
+function def_env.module:unload(name, hosts)
+	hosts = get_hosts_with_module(hosts, name);
+
+	-- Unload the module for each host
+	local ok, err, count = true, nil, 0;
+	for host in hosts do
+		if modulemanager.is_loaded(host, name) then
+			ok, err = modulemanager.unload(host, name);
+			if not ok then
+				ok = false;
+				self.session.print(err or "Unknown error unloading module");
+			else
+				count = count + 1;
+				self.session.print("Unloaded from "..host);
+			end
+		end
+	end
+	return ok, (ok and "Module unloaded from "..count.." host"..(count ~= 1 and "s" or "")) or ("Last error: "..tostring(err));
+end
+
+local function _sort_hosts(a, b)
+	if a == "*" then return true
+	elseif b == "*" then return false
+	else return a:gsub("[^.]+", string.reverse):reverse() < b:gsub("[^.]+", string.reverse):reverse(); end
+end
+
+function def_env.module:reload(name, hosts)
+	hosts = array.collect(get_hosts_with_module(hosts, name)):sort(_sort_hosts)
+
+	-- Reload the module for each host
+	local ok, err, count = true, nil, 0;
+	for _, host in ipairs(hosts) do
+		if modulemanager.is_loaded(host, name) then
+			ok, err = modulemanager.reload(host, name);
+			if not ok then
+				ok = false;
+				self.session.print(err or "Unknown error reloading module");
+			else
+				count = count + 1;
+				if ok == nil then
+					ok = true;
+				end
+				self.session.print("Reloaded on "..host);
+			end
+		end
+	end
+	return ok, (ok and "Module reloaded on "..count.." host"..(count ~= 1 and "s" or "")) or ("Last error: "..tostring(err));
+end
+
+function def_env.module:list(hosts)
+	hosts = array.collect(set.new({ not hosts and "*" or nil }) + get_hosts_set(hosts)):sort(_sort_hosts);
+
+	local print = self.session.print;
+	for _, host in ipairs(hosts) do
+		print((host == "*" and "Global" or host)..":");
+		local modules = array.collect(keys(modulemanager.get_modules(host) or {})):sort();
+		if #modules == 0 then
+			if prosody.hosts[host] then
+				print("    No modules loaded");
+			else
+				print("    Host not found");
+			end
+		else
+			for _, name in ipairs(modules) do
+				local status, status_text = modulemanager.get_module(host, name).module:get_status();
+				local status_summary = "";
+				if status == "warn" or status == "error" then
+					status_summary = (" (%s: %s)"):format(status, status_text);
+				end
+				print(("    %s%s"):format(name, status_summary));
+			end
+		end
+	end
+end
+
+def_env.config = {};
+function def_env.config:load(filename, format)
+	local config_load = require "core.configmanager".load;
+	local ok, err = config_load(filename, format);
+	if not ok then
+		return false, err or "Unknown error loading config";
+	end
+	return true, "Config loaded";
+end
+
+function def_env.config:get(host, key)
+	if key == nil then
+		host, key = "*", host;
+	end
+	local config_get = require "core.configmanager".get
+	return true, serialize_config(config_get(host, key));
+end
+
+function def_env.config:reload()
+	local ok, err = prosody.reload_config();
+	return ok, (ok and "Config reloaded (you may need to reload modules to take effect)") or tostring(err);
+end
+
+local function common_info(session, line)
+	if session.id then
+		line[#line+1] = "["..session.id.."]"
+	else
+		line[#line+1] = "["..session.type..(tostring(session):match("%x*$")).."]"
+	end
+end
+
+local function session_flags(session, line)
+	line = line or {};
+	common_info(session, line);
+	if session.type == "c2s" then
+		local status, priority = "unavailable", tostring(session.priority or "-");
+		if session.presence then
+			status = session.presence:get_child_text("show") or "available";
+		end
+		line[#line+1] = status.."("..priority..")";
+	end
+	if session.cert_identity_status == "valid" then
+		line[#line+1] = "(authenticated)";
+	end
+	if session.dialback_key then
+		line[#line+1] = "(dialback)";
+	end
+	if session.external_auth then
+		line[#line+1] = "(SASL)";
+	end
+	if session.secure then
+		line[#line+1] = "(encrypted)";
+	end
+	if session.compressed then
+		line[#line+1] = "(compressed)";
+	end
+	if session.smacks then
+		line[#line+1] = "(sm)";
+	end
+	if session.ip and session.ip:match(":") then
+		line[#line+1] = "(IPv6)";
+	end
+	if session.remote then
+		line[#line+1] = "(remote)";
+	end
+	if session.incoming and session.outgoing then
+		line[#line+1] = "(bidi)";
+	elseif session.is_bidi or session.bidi_session then
+		line[#line+1] = "(bidi)";
+	end
+	if session.bosh_version then
+		line[#line+1] = "(bosh)";
+	end
+	if session.websocket_request then
+		line[#line+1] = "(websocket)";
+	end
+	return table.concat(line, " ");
+end
+
+local function tls_info(session, line)
+	line = line or {};
+	common_info(session, line);
+	if session.secure then
+		local sock = session.conn and session.conn.socket and session.conn:socket();
+		if sock then
+			local info = sock.info and sock:info();
+			if info then
+				line[#line+1] = ("(%s with %s)"):format(info.protocol, info.cipher);
+			else
+				-- TLS session might not be ready yet
+				line[#line+1] = "(cipher info unavailable)";
+			end
+			if sock.getsniname then
+				local name = sock:getsniname();
+				if name then
+					line[#line+1] = ("(SNI:%q)"):format(name);
+				end
+			end
+			if sock.getalpn then
+				local proto = sock:getalpn();
+				if proto then
+					line[#line+1] = ("(ALPN:%q)"):format(proto);
+				end
+			end
+		end
+	else
+		line[#line+1] = "(insecure)";
+	end
+	return table.concat(line, " ");
+end
+
+def_env.c2s = {};
+
+local function get_jid(session)
+	if session.username then
+		return session.full_jid or jid_join(session.username, session.host, session.resource);
+	end
+
+	local conn = session.conn;
+	local ip = session.ip or "?";
+	local clientport = conn and conn:clientport() or "?";
+	local serverip = conn and conn.server and conn:server():ip() or "?";
+	local serverport = conn and conn:serverport() or "?"
+	return jid_join("["..ip.."]:"..clientport, session.host or "["..serverip.."]:"..serverport);
+end
+
+local function get_c2s()
+	local c2s = array.collect(values(prosody.full_sessions));
+	c2s:append(array.collect(values(module:shared"/*/c2s/sessions")));
+	c2s:append(array.collect(values(module:shared"/*/bosh/sessions")));
+	c2s:unique();
+	return c2s;
+end
+
+local function show_c2s(callback)
+	get_c2s():sort(function(a, b)
+		if a.host == b.host then
+			if a.username == b.username then
+				return (a.resource or "") > (b.resource or "");
+			end
+			return (a.username or "") > (b.username or "");
+		end
+		return _sort_hosts(a.host or "", b.host or "");
+	end):map(function (session)
+		callback(get_jid(session), session)
+	end);
+end
+
+function def_env.c2s:count()
+	local c2s = get_c2s();
+	return true, "Total: "..  #c2s .." clients";
+end
+
+function def_env.c2s:show(match_jid, annotate)
+	local print, count = self.session.print, 0;
+	annotate = annotate or session_flags;
+	local curr_host = false;
+	show_c2s(function (jid, session)
+		if curr_host ~= session.host then
+			curr_host = session.host;
+			print(curr_host or "(not connected to any host yet)");
+		end
+		if (not match_jid) or jid:match(match_jid) then
+			count = count + 1;
+			print(annotate(session, { "  ", jid }));
+		end
+	end);
+	return true, "Total: "..count.." clients";
+end
+
+function def_env.c2s:show_insecure(match_jid)
+	local print, count = self.session.print, 0;
+	show_c2s(function (jid, session)
+		if ((not match_jid) or jid:match(match_jid)) and not session.secure then
+			count = count + 1;
+			print(jid);
+		end
+	end);
+	return true, "Total: "..count.." insecure client connections";
+end
+
+function def_env.c2s:show_secure(match_jid)
+	local print, count = self.session.print, 0;
+	show_c2s(function (jid, session)
+		if ((not match_jid) or jid:match(match_jid)) and session.secure then
+			count = count + 1;
+			print(jid);
+		end
+	end);
+	return true, "Total: "..count.." secure client connections";
+end
+
+function def_env.c2s:show_tls(match_jid)
+	return self:show(match_jid, tls_info);
+end
+
+local function build_reason(text, condition)
+	if text or condition then
+		return {
+			text = text,
+			condition = condition or "undefined-condition",
+		};
+	end
+end
+
+function def_env.c2s:close(match_jid, text, condition)
+	local count = 0;
+	show_c2s(function (jid, session)
+		if jid == match_jid or jid_bare(jid) == match_jid then
+			count = count + 1;
+			session:close(build_reason(text, condition));
+		end
+	end);
+	return true, "Total: "..count.." sessions closed";
+end
+
+function def_env.c2s:closeall(text, condition)
+	local count = 0;
+	--luacheck: ignore 212/jid
+	show_c2s(function (jid, session)
+		count = count + 1;
+		session:close(build_reason(text, condition));
+	end);
+	return true, "Total: "..count.." sessions closed";
+end
+
+
+def_env.s2s = {};
+function def_env.s2s:show(match_jid, annotate)
+	local print = self.session.print;
+	annotate = annotate or session_flags;
+
+	local count_in, count_out = 0,0;
+	local s2s_list = { };
+
+	local s2s_sessions = module:shared"/*/s2s/sessions";
+	for _, session in pairs(s2s_sessions) do
+		local remotehost, localhost, direction;
+		if session.direction == "outgoing" then
+			direction = "->";
+			count_out = count_out + 1;
+			remotehost, localhost = session.to_host or "?", session.from_host or "?";
+		else
+			direction = "<-";
+			count_in = count_in + 1;
+			remotehost, localhost = session.from_host or "?", session.to_host or "?";
+		end
+		local sess_lines = { l = localhost, r = remotehost,
+			annotate(session, { "", direction, remotehost or "?" })};
+
+		if (not match_jid) or remotehost:match(match_jid) or localhost:match(match_jid) then
+			table.insert(s2s_list, sess_lines);
+			-- luacheck: ignore 421/print
+			local print = function (s) table.insert(sess_lines, "        "..s); end
+			if session.sendq then
+				print("There are "..#session.sendq.." queued outgoing stanzas for this connection");
+			end
+			if session.type == "s2sout_unauthed" then
+				if session.connecting then
+					print("Connection not yet established");
+					if not session.srv_hosts then
+						if not session.conn then
+							print("We do not yet have a DNS answer for this host's SRV records");
+						else
+							print("This host has no SRV records, using A record instead");
+						end
+					elseif session.srv_choice then
+						print("We are on SRV record "..session.srv_choice.." of "..#session.srv_hosts);
+						local srv_choice = session.srv_hosts[session.srv_choice];
+						print("Using "..(srv_choice.target or ".")..":"..(srv_choice.port or 5269));
+					end
+				elseif session.notopen then
+					print("The <stream> has not yet been opened");
+				elseif not session.dialback_key then
+					print("Dialback has not been initiated yet");
+				elseif session.dialback_key then
+					print("Dialback has been requested, but no result received");
+				end
+			end
+			if session.type == "s2sin_unauthed" then
+				print("Connection not yet authenticated");
+			elseif session.type == "s2sin" then
+				for name in pairs(session.hosts) do
+					if name ~= session.from_host then
+						print("also hosts "..tostring(name));
+					end
+				end
+			end
+		end
+	end
+
+	-- Sort by local host, then remote host
+	table.sort(s2s_list, function(a,b)
+		if a.l == b.l then return _sort_hosts(a.r, b.r); end
+		return _sort_hosts(a.l, b.l);
+	end);
+	local lasthost;
+	for _, sess_lines in ipairs(s2s_list) do
+		if sess_lines.l ~= lasthost then print(sess_lines.l); lasthost=sess_lines.l end
+		for _, line in ipairs(sess_lines) do print(line); end
+	end
+	return true, "Total: "..count_out.." outgoing, "..count_in.." incoming connections";
+end
+
+function def_env.s2s:show_tls(match_jid)
+	return self:show(match_jid, tls_info);
+end
+
+local function print_subject(print, subject)
+	for _, entry in ipairs(subject) do
+		print(
+			("    %s: %q"):format(
+				entry.name or entry.oid,
+				entry.value:gsub("[\r\n%z%c]", " ")
+			)
+		);
+	end
+end
+
+-- As much as it pains me to use the 0-based depths that OpenSSL does,
+-- I think there's going to be more confusion among operators if we
+-- break from that.
+local function print_errors(print, errors)
+	for depth, t in pairs(errors) do
+		print(
+			("    %d: %s"):format(
+				depth-1,
+				table.concat(t, "\n|        ")
+			)
+		);
+	end
+end
+
+function def_env.s2s:showcert(domain)
+	local print = self.session.print;
+	local s2s_sessions = module:shared"/*/s2s/sessions";
+	local domain_sessions = set.new(array.collect(values(s2s_sessions)))
+		/function(session) return (session.to_host == domain or session.from_host == domain) and session or nil; end;
+	local cert_set = {};
+	for session in domain_sessions do
+		local conn = session.conn;
+		conn = conn and conn:socket();
+		if not conn.getpeerchain then
+			if conn.dohandshake then
+				error("This version of LuaSec does not support certificate viewing");
+			end
+		else
+			local cert = conn:getpeercertificate();
+			if cert then
+				local certs = conn:getpeerchain();
+				local digest = cert:digest("sha1");
+				if not cert_set[digest] then
+					local chain_valid, chain_errors = conn:getpeerverification();
+					cert_set[digest] = {
+						{
+						  from = session.from_host,
+						  to = session.to_host,
+						  direction = session.direction
+						};
+						chain_valid = chain_valid;
+						chain_errors = chain_errors;
+						certs = certs;
+					};
+				else
+					table.insert(cert_set[digest], {
+						from = session.from_host,
+						to = session.to_host,
+						direction = session.direction
+					});
+				end
+			end
+		end
+	end
+	local domain_certs = array.collect(values(cert_set));
+	-- Phew. We now have a array of unique certificates presented by domain.
+	local n_certs = #domain_certs;
+
+	if n_certs == 0 then
+		return "No certificates found for "..domain;
+	end
+
+	local function _capitalize_and_colon(byte)
+		return string.upper(byte)..":";
+	end
+	local function pretty_fingerprint(hash)
+		return hash:gsub("..", _capitalize_and_colon):sub(1, -2);
+	end
+
+	for cert_info in values(domain_certs) do
+		local certs = cert_info.certs;
+		local cert = certs[1];
+		print("---")
+		print("Fingerprint (SHA1): "..pretty_fingerprint(cert:digest("sha1")));
+		print("");
+		local n_streams = #cert_info;
+		print("Currently used on "..n_streams.." stream"..(n_streams==1 and "" or "s")..":");
+		for _, stream in ipairs(cert_info) do
+			if stream.direction == "incoming" then
+				print("    "..stream.to.." <- "..stream.from);
+			else
+				print("    "..stream.from.." -> "..stream.to);
+			end
+		end
+		print("");
+		local chain_valid, errors = cert_info.chain_valid, cert_info.chain_errors;
+		local valid_identity = cert_verify_identity(domain, "xmpp-server", cert);
+		if chain_valid then
+			print("Trusted certificate: Yes");
+		else
+			print("Trusted certificate: No");
+			print_errors(print, errors);
+		end
+		print("");
+		print("Issuer: ");
+		print_subject(print, cert:issuer());
+		print("");
+		print("Valid for "..domain..": "..(valid_identity and "Yes" or "No"));
+		print("Subject:");
+		print_subject(print, cert:subject());
+	end
+	print("---");
+	return ("Showing "..n_certs.." certificate"
+		..(n_certs==1 and "" or "s")
+		.." presented by "..domain..".");
+end
+
+function def_env.s2s:close(from, to, text, condition)
+	local print, count = self.session.print, 0;
+	local s2s_sessions = module:shared"/*/s2s/sessions";
+
+	local match_id;
+	if from and not to then
+		match_id, from = from, nil;
+	elseif not to then
+		return false, "Syntax: s2s:close('from', 'to') - Closes all s2s sessions from 'from' to 'to'";
+	elseif from == to then
+		return false, "Both from and to are the same... you can't do that :)";
+	end
+
+	for _, session in pairs(s2s_sessions) do
+		local id = session.id or (session.type..tostring(session):match("[a-f0-9]+$"));
+		if (match_id and match_id == id)
+		or (session.from_host == from and session.to_host == to) then
+			print(("Closing connection from %s to %s [%s]"):format(session.from_host, session.to_host, id));
+			(session.close or s2smanager.destroy_session)(session, build_reason(text, condition));
+			count = count + 1 ;
+		end
+	end
+	return true, "Closed "..count.." s2s session"..((count == 1 and "") or "s");
+end
+
+function def_env.s2s:closeall(host, text, condition)
+	local count = 0;
+	local s2s_sessions = module:shared"/*/s2s/sessions";
+	for _,session in pairs(s2s_sessions) do
+		if not host or session.from_host == host or session.to_host == host then
+			session:close(build_reason(text, condition));
+			count = count + 1;
+		end
+	end
+	if count == 0 then return false, "No sessions to close.";
+	else return true, "Closed "..count.." s2s session"..((count == 1 and "") or "s"); end
+end
+
+def_env.host = {}; def_env.hosts = def_env.host;
+
+function def_env.host:activate(hostname, config)
+	return hostmanager.activate(hostname, config);
+end
+function def_env.host:deactivate(hostname, reason)
+	return hostmanager.deactivate(hostname, reason);
+end
+
+function def_env.host:list()
+	local print = self.session.print;
+	local i = 0;
+	local type;
+	for host, host_session in iterators.sorted_pairs(prosody.hosts, _sort_hosts) do
+		i = i + 1;
+		type = host_session.type;
+		if type == "local" then
+			print(host);
+		else
+			type = module:context(host):get_option_string("component_module", type);
+			if type ~= "component" then
+				type = type .. " component";
+			end
+			print(("%s (%s)"):format(host, type));
+		end
+	end
+	return true, i.." hosts";
+end
+
+def_env.port = {};
+
+function def_env.port:list()
+	local print = self.session.print;
+	local services = portmanager.get_active_services().data;
+	local n_services, n_ports = 0, 0;
+	for service, interfaces in iterators.sorted_pairs(services) do
+		n_services = n_services + 1;
+		local ports_list = {};
+		for interface, ports in pairs(interfaces) do
+			for port in pairs(ports) do
+				table.insert(ports_list, "["..interface.."]:"..port);
+			end
+		end
+		n_ports = n_ports + #ports_list;
+		print(service..": "..table.concat(ports_list, ", "));
+	end
+	return true, n_services.." services listening on "..n_ports.." ports";
+end
+
+function def_env.port:close(close_port, close_interface)
+	close_port = assert(tonumber(close_port), "Invalid port number");
+	local n_closed = 0;
+	local services = portmanager.get_active_services().data;
+	for service, interfaces in pairs(services) do -- luacheck: ignore 213
+		for interface, ports in pairs(interfaces) do
+			if not close_interface or close_interface == interface then
+				if ports[close_port] then
+					self.session.print("Closing ["..interface.."]:"..close_port.."...");
+					local ok, err = portmanager.close(interface, close_port)
+					if not ok then
+						self.session.print("Failed to close "..interface.." "..close_port..": "..err);
+					else
+						n_closed = n_closed + 1;
+					end
+				end
+			end
+		end
+	end
+	return true, "Closed "..n_closed.." ports";
+end
+
+def_env.muc = {};
+
+local console_room_mt = {
+	__index = function (self, k) return self.room[k]; end;
+	__tostring = function (self)
+		return "MUC room <"..self.room.jid..">";
+	end;
+};
+
+local function check_muc(jid)
+	local room_name, host = jid_split(jid);
+	if not prosody.hosts[host] then
+		return nil, "No such host: "..host;
+	elseif not prosody.hosts[host].modules.muc then
+		return nil, "Host '"..host.."' is not a MUC service";
+	end
+	return room_name, host;
+end
+
+function def_env.muc:create(room_jid, config)
+	local room_name, host = check_muc(room_jid);
+	if not room_name then
+		return room_name, host;
+	end
+	if not room_name then return nil, host end
+	if config ~= nil and type(config) ~= "table" then return nil, "Config must be a table"; end
+	if prosody.hosts[host].modules.muc.get_room_from_jid(room_jid) then return nil, "Room exists already" end
+	return prosody.hosts[host].modules.muc.create_room(room_jid, config);
+end
+
+function def_env.muc:room(room_jid)
+	local room_name, host = check_muc(room_jid);
+	if not room_name then
+		return room_name, host;
+	end
+	local room_obj = prosody.hosts[host].modules.muc.get_room_from_jid(room_jid);
+	if not room_obj then
+		return nil, "No such room: "..room_jid;
+	end
+	return setmetatable({ room = room_obj }, console_room_mt);
+end
+
+function def_env.muc:list(host)
+	local host_session = prosody.hosts[host];
+	if not host_session or not host_session.modules.muc then
+		return nil, "Please supply the address of a local MUC component";
+	end
+	local print = self.session.print;
+	local c = 0;
+	for room in host_session.modules.muc.each_room() do
+		print(room.jid);
+		c = c + 1;
+	end
+	return true, c.." rooms";
+end
+
+local um = require"core.usermanager";
+
+def_env.user = {};
+function def_env.user:create(jid, password)
+	local username, host = jid_split(jid);
+	if not prosody.hosts[host] then
+		return nil, "No such host: "..host;
+	elseif um.user_exists(username, host) then
+		return nil, "User exists";
+	end
+	local ok, err = um.create_user(username, password, host);
+	if ok then
+		return true, "User created";
+	else
+		return nil, "Could not create user: "..err;
+	end
+end
+
+function def_env.user:delete(jid)
+	local username, host = jid_split(jid);
+	if not prosody.hosts[host] then
+		return nil, "No such host: "..host;
+	elseif not um.user_exists(username, host) then
+		return nil, "No such user";
+	end
+	local ok, err = um.delete_user(username, host);
+	if ok then
+		return true, "User deleted";
+	else
+		return nil, "Could not delete user: "..err;
+	end
+end
+
+function def_env.user:password(jid, password)
+	local username, host = jid_split(jid);
+	if not prosody.hosts[host] then
+		return nil, "No such host: "..host;
+	elseif not um.user_exists(username, host) then
+		return nil, "No such user";
+	end
+	local ok, err = um.set_password(username, password, host, nil);
+	if ok then
+		return true, "User password changed";
+	else
+		return nil, "Could not change password for user: "..err;
+	end
+end
+
+function def_env.user:list(host, pat)
+	if not host then
+		return nil, "No host given";
+	elseif not prosody.hosts[host] then
+		return nil, "No such host";
+	end
+	local print = self.session.print;
+	local total, matches = 0, 0;
+	for user in um.users(host) do
+		if not pat or user:match(pat) then
+			print(user.."@"..host);
+			matches = matches + 1;
+		end
+		total = total + 1;
+	end
+	return true, "Showing "..(pat and (matches.." of ") or "all " )..total.." users";
+end
+
+def_env.xmpp = {};
+
+local new_id = require "util.id".medium;
+function def_env.xmpp:ping(localhost, remotehost, timeout)
+	localhost = select(2, jid_split(localhost));
+	remotehost = select(2, jid_split(remotehost));
+	if not localhost then
+		return nil, "Invalid sender hostname";
+	elseif not prosody.hosts[localhost] then
+		return nil, "No such local host";
+	end
+	if not remotehost then
+		return nil, "Invalid destination hostname";
+	elseif prosody.hosts[remotehost] then
+		return nil, "Both hosts are local";
+	end
+	local iq = st.iq{ from=localhost, to=remotehost, type="get", id=new_id()}
+			:tag("ping", {xmlns="urn:xmpp:ping"});
+	local time_start = time.now();
+	local ret, err = async.wait(module:context(localhost):send_iq(iq, nil, timeout));
+	if ret then
+		return true, ("pong from %s in %gs"):format(ret.stanza.attr.from, time.now() - time_start);
+	else
+		return false, tostring(err);
+	end
+end
+
+def_env.dns = {};
+local adns = require"net.adns";
+
+local function get_resolver(session)
+	local resolver = session.dns_resolver;
+	if not resolver then
+		resolver = adns.resolver();
+		session.dns_resolver = resolver;
+	end
+	return resolver;
+end
+
+function def_env.dns:lookup(name, typ, class)
+	local resolver = get_resolver(self.session);
+	local ret, err = async.wait(resolver:lookup_promise(name, typ, class));
+	if ret then
+		return true, ret;
+	elseif err then
+		return false, err;
+	end
+end
+
+function def_env.dns:addnameserver(...)
+	local resolver = get_resolver(self.session);
+	resolver._resolver:addnameserver(...)
+	return true
+end
+
+function def_env.dns:setnameserver(...)
+	local resolver = get_resolver(self.session);
+	resolver._resolver:setnameserver(...)
+	return true
+end
+
+function def_env.dns:purge()
+	local resolver = get_resolver(self.session);
+	resolver._resolver:purge()
+	return true
+end
+
+function def_env.dns:cache()
+	local resolver = get_resolver(self.session);
+	return true, "Cache:\n"..tostring(resolver._resolver.cache)
+end
+
+def_env.http = {};
+
+function def_env.http:list(hosts)
+	local print = self.session.print;
+
+	for host in get_hosts_set(hosts) do
+		local http_apps = modulemanager.get_items("http-provider", host);
+		if #http_apps > 0 then
+			local http_host = module:context(host):get_option_string("http_host");
+			print("HTTP endpoints on "..host..(http_host and (" (using "..http_host.."):") or ":"));
+			for _, provider in ipairs(http_apps) do
+				local url = module:context(host):http_url(provider.name, provider.default_path);
+				print("", url);
+			end
+			print("");
+		end
+	end
+
+	local default_host = module:get_option_string("http_default_host");
+	if not default_host then
+		print("HTTP requests to unknown hosts will return 404 Not Found");
+	else
+		print("HTTP requests to unknown hosts will be handled by "..default_host);
+	end
+	return true;
+end
+
+def_env.debug = {};
+
+function def_env.debug:logevents(host)
+	helpers.log_host_events(host);
+	return true;
+end
+
+function def_env.debug:events(host, event)
+	local events_obj;
+	if host and host ~= "*" then
+		if host == "http" then
+			events_obj = require "net.http.server"._events;
+		elseif not prosody.hosts[host] then
+			return false, "Unknown host: "..host;
+		else
+			events_obj = prosody.hosts[host].events;
+		end
+	else
+		events_obj = prosody.events;
+	end
+	return true, helpers.show_events(events_obj, event);
+end
+
+function def_env.debug:timers()
+	local print = self.session.print;
+	local add_task = require"util.timer".add_task;
+	local h, params = add_task.h, add_task.params;
+	if h then
+		print("-- util.timer");
+		for i, id in ipairs(h.ids) do
+			if not params[id] then
+				print(os.date("%F %T", h.priorities[i]), h.items[id]);
+			elseif not params[id].callback then
+				print(os.date("%F %T", h.priorities[i]), h.items[id], unpack(params[id]));
+			else
+				print(os.date("%F %T", h.priorities[i]), params[id].callback, unpack(params[id]));
+			end
+		end
+	end
+	if server.event_base then
+		local count = 0;
+		for _, v in pairs(debug.getregistry()) do
+			if type(v) == "function" and v.callback and v.callback == add_task._on_timer then
+				count = count + 1;
+			end
+		end
+		print(count .. " libevent callbacks");
+	end
+	if h then
+		local next_time = h:peek();
+		if next_time then
+			return true, os.date("Next event at %F %T (in %%.6fs)", next_time):format(next_time - time.now());
+		end
+	end
+	return true;
+end
+
+-- COMPAT: debug:timers() was timer:info() for some time in trunk
+def_env.timer = { info = def_env.debug.timers };
+
+def_env.stats = {};
+
+local function format_stat(type, value, ref_value)
+	ref_value = ref_value or value;
+	--do return tostring(value) end
+	if type == "duration" then
+		if ref_value < 0.001 then
+			return ("%g µs"):format(value*1000000);
+		elseif ref_value < 0.9 then
+			return ("%0.2f ms"):format(value*1000);
+		end
+		return ("%0.2f"):format(value);
+	elseif type == "size" then
+		if ref_value > 1048576 then
+			return ("%d MB"):format(value/1048576);
+		elseif ref_value > 1024 then
+			return ("%d KB"):format(value/1024);
+		end
+		return ("%d bytes"):format(value);
+	elseif type == "rate" then
+		if ref_value < 0.9 then
+			return ("%0.2f/min"):format(value*60);
+		end
+		return ("%0.2f/sec"):format(value);
+	end
+	return tostring(value);
+end
+
+local stats_methods = {};
+function stats_methods:bounds(_lower, _upper)
+	for _, stat_info in ipairs(self) do
+		local data = stat_info[4];
+		if data then
+			local lower = _lower or data.min;
+			local upper = _upper or data.max;
+			local new_data = {
+				min = lower;
+				max = upper;
+				samples = {};
+				sample_count = 0;
+				count = data.count;
+				units = data.units;
+			};
+			local sum = 0;
+			for _, v in ipairs(data.samples) do
+				if v > upper then
+					break;
+				elseif v>=lower then
+					table.insert(new_data.samples, v);
+					sum = sum + v;
+				end
+			end
+			new_data.sample_count = #new_data.samples;
+			stat_info[4] = new_data;
+			stat_info[3] = sum/new_data.sample_count;
+		end
+	end
+	return self;
+end
+
+function stats_methods:trim(lower, upper)
+	upper = upper or (100-lower);
+	local statistics = require "util.statistics";
+	for _, stat_info in ipairs(self) do
+		-- Strip outliers
+		local data = stat_info[4];
+		if data then
+			local new_data = {
+				min = statistics.get_percentile(data, lower);
+				max = statistics.get_percentile(data, upper);
+				samples = {};
+				sample_count = 0;
+				count = data.count;
+				units = data.units;
+			};
+			local sum = 0;
+			for _, v in ipairs(data.samples) do
+				if v > new_data.max then
+					break;
+				elseif v>=new_data.min then
+					table.insert(new_data.samples, v);
+					sum = sum + v;
+				end
+			end
+			new_data.sample_count = #new_data.samples;
+			stat_info[4] = new_data;
+			stat_info[3] = sum/new_data.sample_count;
+		end
+	end
+	return self;
+end
+
+function stats_methods:max(upper)
+	return self:bounds(nil, upper);
+end
+
+function stats_methods:min(lower)
+	return self:bounds(lower, nil);
+end
+
+function stats_methods:summary()
+	local statistics = require "util.statistics";
+	for _, stat_info in ipairs(self) do
+		local type, value, data = stat_info[2], stat_info[3], stat_info[4];
+		if data and data.samples then
+			table.insert(stat_info.output, string.format("Count: %d (%d captured)",
+				data.count,
+				data.sample_count
+			));
+			table.insert(stat_info.output, string.format("Min: %s  Mean: %s  Max: %s",
+				format_stat(type, data.min),
+				format_stat(type, value),
+				format_stat(type, data.max)
+			));
+			table.insert(stat_info.output, string.format("Q1: %s  Median: %s  Q3: %s",
+				format_stat(type, statistics.get_percentile(data, 25)),
+				format_stat(type, statistics.get_percentile(data, 50)),
+				format_stat(type, statistics.get_percentile(data, 75))
+			));
+		end
+	end
+	return self;
+end
+
+function stats_methods:cfgraph()
+	for _, stat_info in ipairs(self) do
+		local name, type, value, data = unpack(stat_info, 1, 4); -- luacheck: ignore 211
+		local function print(s)
+			table.insert(stat_info.output, s);
+		end
+
+		if data and data.sample_count and data.sample_count > 0 then
+			local raw_histogram = require "util.statistics".get_histogram(data);
+
+			local graph_width, graph_height = 50, 10;
+			local eighth_chars = "   ▁▂▃▄▅▆▇█";
+
+			local range = data.max - data.min;
+
+			if range > 0 then
+				local x_scaling = #raw_histogram/graph_width;
+				local histogram = {};
+				for i = 1, graph_width do
+					histogram[i] = math.max(raw_histogram[i*x_scaling-1] or 0, raw_histogram[i*x_scaling] or 0);
+				end
+
+				print("");
+				print(("_"):rep(52)..format_stat(type, data.max));
+				for row = graph_height, 1, -1 do
+					local row_chars = {};
+					local min_eighths, max_eighths = 8, 0;
+					for i = 1, #histogram do
+						local char_eighths = math.ceil(math.max(math.min((graph_height/(data.max/histogram[i]))-(row-1), 1), 0)*8);
+						if char_eighths < min_eighths then
+							min_eighths = char_eighths;
+						end
+						if char_eighths > max_eighths then
+							max_eighths = char_eighths;
+						end
+						if char_eighths == 0 then
+							row_chars[i] = "-";
+						else
+							local char = eighth_chars:sub(char_eighths*3+1, char_eighths*3+3);
+							row_chars[i] = char;
+						end
+					end
+					print(table.concat(row_chars).."|-"..format_stat(type, data.max/(graph_height/(row-0.5))));
+				end
+				print(("\\    "):rep(11));
+				local x_labels = {};
+				for i = 1, 11 do
+					local s = ("%-4s"):format((i-1)*10);
+					if #s > 4 then
+						s = s:sub(1, 3).."…";
+					end
+					x_labels[i] = s;
+				end
+				print(" "..table.concat(x_labels, " "));
+				local units = "%";
+				local margin = math.floor((graph_width-#units)/2);
+				print((" "):rep(margin)..units);
+			else
+				print("[range too small to graph]");
+			end
+			print("");
+		end
+	end
+	return self;
+end
+
+function stats_methods:histogram()
+	for _, stat_info in ipairs(self) do
+		local name, type, value, data = unpack(stat_info, 1, 4); -- luacheck: ignore 211
+		local function print(s)
+			table.insert(stat_info.output, s);
+		end
+
+		if not data then
+			print("[no data]");
+			return self;
+		elseif not data.sample_count then
+			print("[not a sampled metric type]");
+			return self;
+		end
+
+		local graph_width, graph_height = 50, 10;
+		local eighth_chars = "   ▁▂▃▄▅▆▇█";
+
+		local range = data.max - data.min;
+
+		if range > 0 then
+			local n_buckets = graph_width;
+
+			local histogram = {};
+			for i = 1, n_buckets do
+				histogram[i] = 0;
+			end
+			local max_bin_samples = 0;
+			for _, d in ipairs(data.samples) do
+				local bucket = math.floor(1+(n_buckets-1)/(range/(d-data.min)));
+				histogram[bucket] = histogram[bucket] + 1;
+				if histogram[bucket] > max_bin_samples then
+					max_bin_samples = histogram[bucket];
+				end
+			end
+
+			print("");
+			print(("_"):rep(52)..max_bin_samples);
+			for row = graph_height, 1, -1 do
+				local row_chars = {};
+				local min_eighths, max_eighths = 8, 0;
+				for i = 1, #histogram do
+					local char_eighths = math.ceil(math.max(math.min((graph_height/(max_bin_samples/histogram[i]))-(row-1), 1), 0)*8);
+					if char_eighths < min_eighths then
+						min_eighths = char_eighths;
+					end
+					if char_eighths > max_eighths then
+						max_eighths = char_eighths;
+					end
+					if char_eighths == 0 then
+						row_chars[i] = "-";
+					else
+						local char = eighth_chars:sub(char_eighths*3+1, char_eighths*3+3);
+						row_chars[i] = char;
+					end
+				end
+				print(table.concat(row_chars).."|-"..math.ceil((max_bin_samples/graph_height)*(row-0.5)));
+			end
+			print(("\\    "):rep(11));
+			local x_labels = {};
+			for i = 1, 11 do
+				local s = ("%-4s"):format(format_stat(type, data.min+range*i/11, data.min):match("^%S+"));
+				if #s > 4 then
+					s = s:sub(1, 3).."…";
+				end
+				x_labels[i] = s;
+			end
+			print(" "..table.concat(x_labels, " "));
+			local units = format_stat(type, data.min):match("%s+(.+)$") or data.units or "";
+			local margin = math.floor((graph_width-#units)/2);
+			print((" "):rep(margin)..units);
+		else
+			print("[range too small to graph]");
+		end
+		print("");
+	end
+	return self;
+end
+
+local function stats_tostring(stats)
+	local print = stats.session.print;
+	for _, stat_info in ipairs(stats) do
+		if #stat_info.output > 0 then
+			print("\n#"..stat_info[1]);
+			print("");
+			for _, v in ipairs(stat_info.output) do
+				print(v);
+			end
+			print("");
+		else
+			print(("%-50s %s"):format(stat_info[1], format_stat(stat_info[2], stat_info[3])));
+		end
+	end
+	return #stats.." statistics displayed";
+end
+
+local stats_mt = {__index = stats_methods, __tostring = stats_tostring }
+local function new_stats_context(self)
+	return setmetatable({ session = self.session, stats = true }, stats_mt);
+end
+
+function def_env.stats:show(filter)
+	-- luacheck: ignore 211/changed
+	local stats, changed, extra = require "core.statsmanager".get_stats();
+	local available, displayed = 0, 0;
+	local displayed_stats = new_stats_context(self);
+	for name, value in iterators.sorted_pairs(stats) do
+		available = available + 1;
+		if not filter or name:match(filter) then
+			displayed = displayed + 1;
+			local type = name:match(":(%a+)$");
+			table.insert(displayed_stats, {
+				name, type, value, extra[name];
+				output = {};
+			});
+		end
+	end
+	return displayed_stats;
+end
+
+
+
+-------------
+
+function printbanner(session)
+	local option = module:get_option_string("console_banner", "full");
+	if option == "full" or option == "graphic" then
+		session.print [[
+                   ____                \   /     _
+                    |  _ \ _ __ ___  ___  _-_   __| |_   _
+                    | |_) | '__/ _ \/ __|/ _ \ / _` | | | |
+                    |  __/| | | (_) \__ \ |_| | (_| | |_| |
+                    |_|   |_|  \___/|___/\___/ \__,_|\__, |
+                    A study in simplicity            |___/
+
+]]
+	end
+	if option == "short" or option == "full" then
+	session.print("Welcome to the Prosody administration console. For a list of commands, type: help");
+	session.print("You may find more help on using this console in our online documentation at ");
+	session.print("https://prosody.im/doc/console\n");
+	end
+	if option ~= "short" and option ~= "full" and option ~= "graphic" then
+		session.print(option);
+	end
+end