2 -- server.lua by blastbeat of the luadch project
3 -- Re-used here under the MIT/X Consortium License
5 -- Modifications (C) 2008-2010 Matthew Wild, Waqas Hussain
8 -- // wrapping luadch stuff // --
10 local use = function( what )
14 local log, table_concat = require ("util.logger").init("socket"), table.concat;
15 local out_put = function (...) return log("debug", table_concat{...}); end
16 local out_error = function (...) return log("warn", table_concat{...}); end
18 ----------------------------------// DECLARATION //--
22 local STAT_UNIT = 1 -- byte
24 --// lua functions //--
26 local type = use "type"
27 local pairs = use "pairs"
28 local ipairs = use "ipairs"
29 local tonumber = use "tonumber"
30 local tostring = use "tostring"
35 local table = use "table"
36 local string = use "string"
37 local coroutine = use "coroutine"
39 --// lua lib methods //--
41 local os_difftime = os.difftime
42 local math_min = math.min
43 local math_huge = math.huge
44 local table_concat = table.concat
45 local string_sub = string.sub
46 local coroutine_wrap = coroutine.wrap
47 local coroutine_yield = coroutine.yield
51 local luasec = use "ssl"
52 local luasocket = use "socket" or require "socket"
53 local luasocket_gettime = luasocket.gettime
55 --// extern lib methods //--
57 local ssl_wrap = ( luasec and luasec.wrap )
58 local socket_bind = luasocket.bind
59 local socket_sleep = luasocket.sleep
60 local socket_select = luasocket.select
92 --// simple data types //--
121 local _maxsslhandshake
123 ----------------------------------// DEFINITION //--
125 _server = { } -- key = port, value = table; list of listening servers
126 _readlist = { } -- array with sockets to read from
127 _sendlist = { } -- arrary with sockets to write to
128 _timerlist = { } -- array of timer functions
129 _socketlist = { } -- key = socket, value = wrapped socket (handlers)
130 _readtimes = { } -- key = handler, value = timestamp of last data reading
131 _writetimes = { } -- key = handler, value = timestamp of last data writing/sending
132 _closelist = { } -- handlers to close
134 _readlistlen = 0 -- length of readlist
135 _sendlistlen = 0 -- length of sendlist
136 _timerlistlen = 0 -- lenght of timerlist
138 _sendtraffic = 0 -- some stats
141 _selecttimeout = 1 -- timeout of socket.select
142 _sleeptime = 0 -- time to wait at the end of every loop
143 _tcpbacklog = 128 -- some kind of hint to the OS
145 _maxsendlen = 51000 * 1024 -- max len of send buffer
146 _maxreadlen = 25000 * 1024 -- max len of read buffer
148 _checkinterval = 30 -- interval in secs to check idle clients
149 _sendtimeout = 60000 -- allowed send idle time in secs
150 _readtimeout = 6 * 60 * 60 -- allowed read idle time in secs
152 local is_windows = package.config:sub(1,1) == "\\" -- check the directory separator, to detemine whether this is Windows
153 _maxfd = luasocket._SETSIZE or (is_windows and math.huge) or 1024 -- max fd number, limit to 1024 by default to prevent glibc buffer overflow, but not on Windows
154 _maxselectlen = luasocket._SETSIZE or 1024 -- But this still applies on Windows
156 _maxsslhandshake = 30 -- max handshake round-trips
158 ----------------------------------// PRIVATE //--
160 wrapserver = function( listeners, socket, ip, serverport, pattern, sslctx ) -- this function wraps a server -- FIXME Make sure FD < _maxfd
162 if socket:getfd() >= _maxfd then
163 out_error("server.lua: Disallowed FD number: "..socket:getfd())
165 return nil, "fd-too-large"
168 local connections = 0
170 local dispatch, disconnect = listeners.onconnect, listeners.ondisconnect
172 local accept = socket.accept
174 --// public methods of the object //--
178 handler.shutdown = function( ) end
180 handler.ssl = function( )
183 handler.sslctx = function( )
186 handler.remove = function( )
187 connections = connections - 1
192 handler.close = function()
194 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )
195 _readlistlen = removesocket( _readlist, socket, _readlistlen )
196 _server[ip..":"..serverport] = nil;
197 _socketlist[ socket ] = nil
201 out_put "server.lua: closed server handler and removed sockets from list"
203 handler.pause = function( hard )
204 if not handler.paused then
205 _readlistlen = removesocket( _readlist, socket, _readlistlen )
207 _socketlist[ socket ] = nil
211 handler.paused = true;
214 handler.resume = function( )
215 if handler.paused then
217 socket = socket_bind( ip, serverport, _tcpbacklog );
218 socket:settimeout( 0 )
220 _readlistlen = addsocket(_readlist, socket, _readlistlen)
221 _socketlist[ socket ] = handler
222 handler.paused = false;
225 handler.ip = function( )
228 handler.serverport = function( )
231 handler.socket = function( )
234 handler.readbuffer = function( )
235 if _readlistlen >= _maxselectlen or _sendlistlen >= _maxselectlen then
237 out_put( "server.lua: refused new client connection: server full" )
240 local client, err = accept( socket ) -- try to accept
242 local ip, clientport = client:getpeername( )
243 local handler, client, err = wrapconnection( handler, listeners, client, ip, serverport, clientport, pattern, sslctx ) -- wrap new client socket
244 if err then -- error while wrapping ssl socket
247 connections = connections + 1
248 out_put( "server.lua: accepted new client connection from ", tostring(ip), ":", tostring(clientport), " to ", tostring(serverport))
249 if dispatch and not sslctx then -- SSL connections will notify onconnect when handshake completes
250 return dispatch( handler );
253 elseif err then -- maybe timeout or something else
254 out_put( "server.lua: error with new client connection: ", tostring(err) )
261 wrapconnection = function( server, listeners, socket, ip, serverport, clientport, pattern, sslctx ) -- this function wraps a client to a handler object
263 if socket:getfd() >= _maxfd then
264 out_error("server.lua: Disallowed FD number: "..socket:getfd()) -- PROTIP: Switch to libevent
265 socket:close( ) -- Should we send some kind of error here?
267 return nil, nil, "fd-too-large"
269 socket:settimeout( 0 )
271 --// local import of socket methods //--
277 --// private closures of the object //--
281 local dispatch = listeners.onincoming
282 local status = listeners.onstatus
283 local disconnect = listeners.ondisconnect
284 local drain = listeners.ondrain
286 local bufferqueue = { } -- buffer array
287 local bufferqueuelen = 0 -- end of buffer array
298 local sendtraffic, readtraffic = 0, 0
300 local maxsendlen = _maxsendlen
301 local maxreadlen = _maxreadlen
303 --// public methods of the object //--
305 local handler = bufferqueue -- saves a table ^_^
307 handler.dispatch = function( )
310 handler.disconnect = function( )
313 handler.setlistener = function( self, listeners )
314 dispatch = listeners.onincoming
315 disconnect = listeners.ondisconnect
316 status = listeners.onstatus
317 drain = listeners.ondrain
319 handler.getstats = function( )
320 return readtraffic, sendtraffic
322 handler.ssl = function( )
325 handler.sslctx = function ( )
328 handler.send = function( _, data, i, j )
329 return send( socket, data, i, j )
331 handler.receive = function( pattern, prefix )
332 return receive( socket, pattern, prefix )
334 handler.shutdown = function( pattern )
335 return shutdown( socket, pattern )
337 handler.setoption = function (self, option, value)
338 if socket.setoption then
339 return socket:setoption(option, value);
341 return false, "setoption not implemented";
343 handler.force_close = function ( self, err )
344 if bufferqueuelen ~= 0 then
345 out_put("server.lua: discarding unwritten data for ", tostring(ip), ":", tostring(clientport))
348 return self:close(err);
350 handler.close = function( self, err )
351 if not handler then return true; end
352 _readlistlen = removesocket( _readlist, socket, _readlistlen )
353 _readtimes[ handler ] = nil
354 if bufferqueuelen ~= 0 then
355 handler.sendbuffer() -- Try now to send any outstanding data
356 if bufferqueuelen ~= 0 then -- Still not empty, so we'll try again later
358 handler.write = nil -- ... but no further writing allowed
365 _ = shutdown and shutdown( socket )
367 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )
368 _socketlist[ socket ] = nil
371 out_put "server.lua: socket already closed"
374 _writetimes[ handler ] = nil
375 _closelist[ handler ] = nil
376 local _handler = handler;
379 disconnect(_handler, err or false);
386 out_put "server.lua: closed client handler and removed socket from list"
389 handler.ip = function( )
392 handler.serverport = function( )
395 handler.clientport = function( )
398 local write = function( self, data )
399 bufferlen = bufferlen + #data
400 if bufferlen > maxsendlen then
401 _closelist[ handler ] = "send buffer exceeded" -- cannot close the client at the moment, have to wait to the end of the cycle
402 handler.write = idfalse -- dont write anymore
404 elseif socket and not _sendlist[ socket ] then
405 _sendlistlen = addsocket(_sendlist, socket, _sendlistlen)
407 bufferqueuelen = bufferqueuelen + 1
408 bufferqueue[ bufferqueuelen ] = data
410 _writetimes[ handler ] = _writetimes[ handler ] or _currenttime
414 handler.write = write
415 handler.bufferqueue = function( self )
418 handler.socket = function( self )
421 handler.set_mode = function( self, new )
422 pattern = new or pattern
425 handler.set_send = function ( self, newsend )
426 send = newsend or send
429 handler.bufferlen = function( self, readlen, sendlen )
430 maxsendlen = sendlen or maxsendlen
431 maxreadlen = readlen or maxreadlen
432 return bufferlen, maxreadlen, maxsendlen
435 handler.lock_read = function (self, switch)
436 if switch == true then
437 local tmp = _readlistlen
438 _readlistlen = removesocket( _readlist, socket, _readlistlen )
439 _readtimes[ handler ] = nil
440 if _readlistlen ~= tmp then
443 elseif switch == false then
446 _readlistlen = addsocket(_readlist, socket, _readlistlen)
447 _readtimes[ handler ] = _currenttime
452 handler.pause = function (self)
453 return self:lock_read(true);
455 handler.resume = function (self)
456 return self:lock_read(false);
458 handler.lock = function( self, switch )
459 handler.lock_read (switch)
460 if switch == true then
461 handler.write = idfalse
462 local tmp = _sendlistlen
463 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )
464 _writetimes[ handler ] = nil
465 if _sendlistlen ~= tmp then
468 elseif switch == false then
469 handler.write = write
475 return noread, nosend
477 local _readbuffer = function( ) -- this function reads data
478 local buffer, err, part = receive( socket, pattern ) -- receive buffer with "pattern"
479 if not err or (err == "wantread" or err == "timeout") then -- received something
480 local buffer = buffer or part or ""
482 if len > maxreadlen then
483 handler:close( "receive buffer exceeded" )
486 local count = len * STAT_UNIT
487 readtraffic = readtraffic + count
488 _readtraffic = _readtraffic + count
489 _readtimes[ handler ] = _currenttime
490 --out_put( "server.lua: read data '", buffer:gsub("[^%w%p ]", "."), "', error: ", err )
491 return dispatch( handler, buffer, err )
492 else -- connections was closed or fatal error
493 out_put( "server.lua: client ", tostring(ip), ":", tostring(clientport), " read error: ", tostring(err) )
495 _ = handler and handler:force_close( err )
499 local _sendbuffer = function( ) -- this function sends data
500 local succ, err, byte, buffer, count;
502 buffer = table_concat( bufferqueue, "", 1, bufferqueuelen )
503 succ, err, byte = send( socket, buffer, 1, bufferlen )
504 count = ( succ or byte or 0 ) * STAT_UNIT
505 sendtraffic = sendtraffic + count
506 _sendtraffic = _sendtraffic + count
507 for i = bufferqueuelen,1,-1 do
508 bufferqueue[ i ] = nil
510 --out_put( "server.lua: sended '", buffer, "', bytes: ", tostring(succ), ", error: ", tostring(err), ", part: ", tostring(byte), ", to: ", tostring(ip), ":", tostring(clientport) )
512 succ, err, count = false, "unexpected close", 0;
514 if succ then -- sending succesful
517 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen ) -- delete socket from writelist
518 _writetimes[ handler ] = nil
522 _ = needtls and handler:starttls(nil)
523 _ = toclose and handler:force_close( )
525 elseif byte and ( err == "timeout" or err == "wantwrite" ) then -- want write
526 buffer = string_sub( buffer, byte + 1, bufferlen ) -- new buffer
527 bufferqueue[ 1 ] = buffer -- insert new buffer in queue
529 bufferlen = bufferlen - byte
530 _writetimes[ handler ] = _currenttime
532 else -- connection was closed during sending or fatal error
533 out_put( "server.lua: client ", tostring(ip), ":", tostring(clientport), " write error: ", tostring(err) )
535 _ = handler and handler:force_close( err )
542 function handler.set_sslctx(self, new_sslctx)
545 handshake = coroutine_wrap( function( client ) -- create handshake coroutine
547 for i = 1, _maxsslhandshake do
548 _sendlistlen = ( wrote and removesocket( _sendlist, client, _sendlistlen ) ) or _sendlistlen
549 _readlistlen = ( read and removesocket( _readlist, client, _readlistlen ) ) or _readlistlen
550 read, wrote = nil, nil
551 _, err = client:dohandshake( )
553 out_put( "server.lua: ssl handshake done" )
554 handler.readbuffer = _readbuffer -- when handshake is done, replace the handshake function with regular functions
555 handler.sendbuffer = _sendbuffer
556 _ = status and status( handler, "ssl-handshake-complete" )
557 if self.autostart_ssl and listeners.onconnect then
558 listeners.onconnect(self);
560 _readlistlen = addsocket(_readlist, client, _readlistlen)
563 if err == "wantwrite" then
564 _sendlistlen = addsocket(_sendlist, client, _sendlistlen)
566 elseif err == "wantread" then
567 _readlistlen = addsocket(_readlist, client, _readlistlen)
573 coroutine_yield( ) -- handshake not finished
576 out_put( "server.lua: ssl handshake error: ", tostring(err or "handshake too long") )
577 _ = handler and handler:force_close("ssl handshake failed")
578 return false, err -- handshake failed
583 handler.starttls = function( self, _sslctx)
585 handler:set_sslctx(_sslctx);
587 if bufferqueuelen > 0 then
588 out_put "server.lua: we need to do tls, but delaying until send buffer empty"
592 out_put( "server.lua: attempting to start tls on " .. tostring( socket ) )
593 local oldsocket, err = socket
594 socket, err = ssl_wrap( socket, sslctx ) -- wrap socket
596 out_put( "server.lua: error while starting tls on client: ", tostring(err or "unknown error") )
597 return nil, err -- fatal error
600 socket:settimeout( 0 )
602 -- add the new socket to our system
604 receive = socket.receive
606 _socketlist[ socket ] = handler
607 _readlistlen = addsocket(_readlist, socket, _readlistlen)
609 -- remove traces of the old socket
610 _readlistlen = removesocket( _readlist, oldsocket, _readlistlen )
611 _sendlistlen = removesocket( _sendlist, oldsocket, _sendlistlen )
612 _socketlist[ oldsocket ] = nil
614 handler.starttls = nil
617 -- Secure now (if handshake fails connection will close)
620 handler.readbuffer = handshake
621 handler.sendbuffer = handshake
622 return handshake( socket ) -- do handshake
626 handler.readbuffer = _readbuffer
627 handler.sendbuffer = _sendbuffer
629 receive = socket.receive
630 shutdown = ( ssl and id ) or socket.shutdown
632 _socketlist[ socket ] = handler
633 _readlistlen = addsocket(_readlist, socket, _readlistlen)
635 if sslctx and luasec then
636 out_put "server.lua: auto-starting ssl negotiation..."
637 handler.autostart_ssl = true;
638 local ok, err = handler:starttls(sslctx);
644 return handler, socket
650 idfalse = function( )
654 addsocket = function( list, socket, len )
655 if not list[ socket ] then
663 removesocket = function( list, socket, len ) -- this function removes sockets from a list ( copied from copas )
664 local pos = list[ socket ]
667 local last = list[ len ]
669 if last ~= socket then
678 closesocket = function( socket )
679 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )
680 _readlistlen = removesocket( _readlist, socket, _readlistlen )
681 _socketlist[ socket ] = nil
686 local function link(sender, receiver, buffersize)
688 local _sendbuffer = receiver.sendbuffer;
689 function receiver.sendbuffer()
691 if sender_locked and receiver.bufferlen() < buffersize then
692 sender:lock_read(false); -- Unlock now
697 local _readbuffer = sender.readbuffer;
698 function sender.readbuffer()
700 if not sender_locked and receiver.bufferlen() >= buffersize then
701 sender_locked = true;
702 sender:lock_read(true);
707 ----------------------------------// PUBLIC //--
709 addserver = function( addr, port, listeners, pattern, sslctx ) -- this function provides a way for other scripts to reg a server
711 if type( listeners ) ~= "table" then
712 err = "invalid listener table"
714 if type( port ) ~= "number" or not ( port >= 0 and port <= 65535 ) then
716 elseif _server[ addr..":"..port ] then
717 err = "listeners on '[" .. addr .. "]:" .. port .. "' already exist"
718 elseif sslctx and not luasec then
719 err = "luasec not found"
722 out_error( "server.lua, [", addr, "]:", port, ": ", err )
726 local server, err = socket_bind( addr, port, _tcpbacklog )
728 out_error( "server.lua, [", addr, "]:", port, ": ", err )
731 local handler, err = wrapserver( listeners, server, addr, port, pattern, sslctx ) -- wrap new server socket
736 server:settimeout( 0 )
737 _readlistlen = addsocket(_readlist, server, _readlistlen)
738 _server[ addr..":"..port ] = handler
739 _socketlist[ server ] = handler
740 out_put( "server.lua: new "..(sslctx and "ssl " or "").."server listener on '[", addr, "]:", port, "'" )
744 getserver = function ( addr, port )
745 return _server[ addr..":"..port ];
748 removeserver = function( addr, port )
749 local handler = _server[ addr..":"..port ]
751 return nil, "no server found on '[" .. addr .. "]:" .. tostring( port ) .. "'"
754 _server[ addr..":"..port ] = nil
758 closeall = function( )
759 for _, handler in pairs( _socketlist ) do
761 _socketlist[ _ ] = nil
774 getsettings = function( )
776 select_timeout = _selecttimeout;
777 select_sleep_time = _sleeptime;
778 tcp_backlog = _tcpbacklog;
779 max_send_buffer_size = _maxsendlen;
780 max_receive_buffer_size = _maxreadlen;
781 select_idle_check_interval = _checkinterval;
782 send_timeout = _sendtimeout;
783 read_timeout = _readtimeout;
784 max_connections = _maxselectlen;
785 max_ssl_handshake_roundtrips = _maxsslhandshake;
786 highest_allowed_fd = _maxfd;
790 changesettings = function( new )
791 if type( new ) ~= "table" then
792 return nil, "invalid settings table"
794 _selecttimeout = tonumber( new.select_timeout ) or _selecttimeout
795 _sleeptime = tonumber( new.select_sleep_time ) or _sleeptime
796 _maxsendlen = tonumber( new.max_send_buffer_size ) or _maxsendlen
797 _maxreadlen = tonumber( new.max_receive_buffer_size ) or _maxreadlen
798 _checkinterval = tonumber( new.select_idle_check_interval ) or _checkinterval
799 _tcpbacklog = tonumber( new.tcp_backlog ) or _tcpbacklog
800 _sendtimeout = tonumber( new.send_timeout ) or _sendtimeout
801 _readtimeout = tonumber( new.read_timeout ) or _readtimeout
802 _maxselectlen = new.max_connections or _maxselectlen
803 _maxsslhandshake = new.max_ssl_handshake_roundtrips or _maxsslhandshake
804 _maxfd = new.highest_allowed_fd or _maxfd
808 addtimer = function( listener )
809 if type( listener ) ~= "function" then
810 return nil, "invalid listener function"
812 _timerlistlen = _timerlistlen + 1
813 _timerlist[ _timerlistlen ] = listener
818 return _readtraffic, _sendtraffic, _readlistlen, _sendlistlen, _timerlistlen
823 local function setquitting(quit)
824 quitting = not not quit;
827 loop = function(once) -- this is the main loop of the program
828 if quitting then return "quitting"; end
829 if once then quitting = "once"; end
830 local next_timer_time = math_huge;
832 local read, write, err = socket_select( _readlist, _sendlist, math_min(_selecttimeout, next_timer_time) )
833 for i, socket in ipairs( write ) do -- send data waiting in writequeues
834 local handler = _socketlist[ socket ]
836 handler.sendbuffer( )
838 closesocket( socket )
839 out_put "server.lua: found no handler and closed socket (writelist)" -- this should not happen
842 for i, socket in ipairs( read ) do -- receive data
843 local handler = _socketlist[ socket ]
845 handler.readbuffer( )
847 closesocket( socket )
848 out_put "server.lua: found no handler and closed socket (readlist)" -- this can happen
851 for handler, err in pairs( _closelist ) do
852 handler.disconnect( )( handler, err )
853 handler:force_close() -- forced disconnect
854 _closelist[ handler ] = nil;
856 _currenttime = luasocket_gettime( )
858 -- Check for socket timeouts
859 local difftime = os_difftime( _currenttime - _starttime )
860 if difftime > _checkinterval then
861 _starttime = _currenttime
862 for handler, timestamp in pairs( _writetimes ) do
863 if os_difftime( _currenttime - timestamp ) > _sendtimeout then
864 handler.disconnect( )( handler, "send timeout" )
865 handler:force_close() -- forced disconnect
868 for handler, timestamp in pairs( _readtimes ) do
869 if os_difftime( _currenttime - timestamp ) > _readtimeout then
870 if not(handler.onreadtimeout) or handler:onreadtimeout() ~= true then
871 handler.disconnect( )( handler, "read timeout" )
872 handler:close( ) -- forced disconnect?
879 if _currenttime - _timer >= math_min(next_timer_time, 1) then
880 next_timer_time = math_huge;
881 for i = 1, _timerlistlen do
882 local t = _timerlist[ i ]( _currenttime ) -- fire timers
883 if t then next_timer_time = math_min(next_timer_time, t); end
885 _timer = _currenttime
887 next_timer_time = next_timer_time - (_currenttime - _timer);
890 -- wait some time (0 by default)
891 socket_sleep( _sleeptime )
893 if once and quitting == "once" then quitting = nil; return; end
897 local function step()
901 local function get_backend()
905 --// EXPERIMENTAL //--
907 local wrapclient = function( socket, ip, serverport, listeners, pattern, sslctx )
908 local handler, socket, err = wrapconnection( nil, listeners, socket, ip, serverport, "clientport", pattern, sslctx )
909 if not handler then return nil, err end
910 _socketlist[ socket ] = handler
912 _sendlistlen = addsocket(_sendlist, socket, _sendlistlen)
913 if listeners.onconnect then
914 -- When socket is writeable, call onconnect
915 local _sendbuffer = handler.sendbuffer;
916 handler.sendbuffer = function ()
917 _sendlistlen = removesocket( _sendlist, socket, _sendlistlen );
918 handler.sendbuffer = _sendbuffer;
919 listeners.onconnect(handler);
920 -- If there was data with the incoming packet, handle it now.
921 if #handler:bufferqueue() > 0 then
922 return _sendbuffer();
927 return handler, socket
930 local addclient = function( address, port, listeners, pattern, sslctx )
931 local client, err = luasocket.tcp( )
935 client:settimeout( 0 )
936 _, err = client:connect( address, port )
937 if err then -- try again
938 local handler = wrapclient( client, address, port, listeners )
940 wrapconnection( nil, listeners, client, address, port, "clientport", pattern, sslctx )
944 --// EXPERIMENTAL //--
946 ----------------------------------// BEGIN //--
948 use "setmetatable" ( _socketlist, { __mode = "k" } )
949 use "setmetatable" ( _readtimes, { __mode = "k" } )
950 use "setmetatable" ( _writetimes, { __mode = "k" } )
952 _timer = luasocket_gettime( )
953 _starttime = luasocket_gettime( )
955 local function setlogger(new_logger)
956 local old_logger = log;
963 ----------------------------------// PUBLIC INTERFACE //--
966 _addtimer = addtimer,
968 addclient = addclient,
969 wrapclient = wrapclient,
976 addserver = addserver,
977 getserver = getserver,
978 setlogger = setlogger,
979 getsettings = getsettings,
980 setquitting = setquitting,
981 removeserver = removeserver,
982 get_backend = get_backend,
983 changesettings = changesettings,