Merge with 0.4
[prosody.git] / net / server.lua
index 68fa5be341d1ebf77610b1ec597fc23429b47455..9e42b8ff8006fe2d9b5d7c991b71dae905a4c20e 100644 (file)
---[[
-
-               server.lua by blastbeat of the luadch project
-               
-               re-used here under the MIT/X Consortium License
-               
-               Modifications (C) 2008 Matthew Wild, Waqas Hussain
-]]--
-
-----------------------------------// DECLARATION //--
-
---// constants //--
-
-local STAT_UNIT = 1 / ( 1024 * 1024 )    -- mb
-
---// lua functions //--
-
-local function use( what ) return _G[ what ] end
-
-local type = use "type"
-local pairs = use "pairs"
-local ipairs = use "ipairs"
-local tostring = use "tostring"
-local collectgarbage = use "collectgarbage"
-
---// lua libs //--
-
-local table = use "table"
-local coroutine = use "coroutine"
-
---// lua lib methods //--
-
-local table_concat = table.concat
-local table_remove = table.remove
-local string_sub = use'string'.sub
-local coroutine_wrap = coroutine.wrap
-local coroutine_yield = coroutine.yield
-local print = print;
-local out_put = function () end --print;
-local out_put = print;
-local out_error = print;
-
---// extern libs //--
-
-local luasec = select(2, pcall(require, "ssl"))
-local luasocket = require "socket"
-
---// extern lib methods //--
-
-local ssl_wrap = ( luasec and luasec.wrap )
-local socket_bind = luasocket.bind
-local socket_select = luasocket.select
-local ssl_newcontext = ( luasec and luasec.newcontext )
-
---// functions //--
-
-local loop
-local stats
-local addtimer
-local closeall
-local addserver
-local firetimer
-local closesocket
-local removesocket
-local wrapserver
-local wraptcpclient
-local wrapsslclient
-
---// tables //--
-
-local listener
-local readlist
-local writelist
-local socketlist
-local timelistener
-
---// simple data types //--
-
-local _
-local readlen = 0    -- length of readlist
-local writelen = 0    -- lenght of writelist
-
-local sendstat= 0
-local receivestat = 0
-
-----------------------------------// DEFINITION //--
-
-listener = { }    -- key = port, value = table
-readlist = { }    -- array with sockets to read from
-writelist = { }    -- arrary with sockets to write to
-socketlist = { }    -- key = socket, value = wrapped socket
-timelistener = { }
-
-stats = function( )
-       return receivestat, sendstat
-end
-
-wrapserver = function( listener, socket, ip, serverport, mode, sslctx )    -- this function wraps a server
-
-       local dispatch, disconnect = listener.listener, listener.disconnect    -- dangerous
-
-       local wrapclient, err
-
-       out_put("Starting a new server on "..tostring(serverport).." with ssl: "..tostring(sslctx));
-       
-       if sslctx then
-               if not ssl_newcontext then
-                       return nil, "luasec not found"
-               end
-               if type( sslctx ) ~= "table" then
-                       out_error "server.lua: wrong server sslctx"
-                       return nil, "wrong server sslctx"
-               end
-               sslctx, err = ssl_newcontext( sslctx )
-               if not sslctx then
-                       err = err or "wrong sslctx parameters"
-                       out_error( "server.lua: ", err )
-                       return nil, err
-               end
-               wrapclient = wrapsslclient
-               wrapclient = wraptlsclient
-       else
-               wrapclient = wraptcpclient
-       end
-
-       local accept = socket.accept
-       local close = socket.close
-
-       --// public methods of the object //--    
-
-       local handler = { }
-
-       handler.shutdown = function( ) end
-
-       --[[handler.listener = function( data, err )
-               return ondata( handler, data, err )
-       end]]
-       handler.ssl = function( )
-               return sslctx and true or false
-       end
-       handler.close = function( closed )
-               _ = not closed and close( socket )
-               writelen = removesocket( writelist, socket, writelen )
-               readlen = removesocket( readlist, socket, readlen )
-               socketlist[ socket ] = nil
-               handler = nil
-       end
-       handler.ip = function( )
-               return ip
-       end
-       handler.serverport = function( )
-               return serverport
-       end
-       handler.socket = function( )
-               return socket
-       end
-       handler.receivedata = function( )
-               local client, err = accept( socket )    -- try to accept
-               if client then
-                       local ip, clientport = client:getpeername( )
-                       client:settimeout( 0 )
-                       local handler, client, err = wrapclient( listener, client, ip, serverport, clientport, mode, sslctx )    -- wrap new client socket
-                       if err then    -- error while wrapping ssl socket
-                               return false
-                       end
-                       out_put( "server.lua: accepted new client connection from ", ip, ":", clientport )
-                       return dispatch( handler )
-               elseif err then    -- maybe timeout or something else
-                       out_put( "server.lua: error with new client connection: ", err )
-                       return false
-               end
-       end
-       return handler
-end
-
-wrapsslclient = function( listener, socket, ip, serverport, clientport, mode, sslctx )    -- this function wraps a ssl cleint
-
-       local dispatch, disconnect = listener.listener, listener.disconnect
-
-       --// transform socket to ssl object //--
-
-       local err
-       socket, err = ssl_wrap( socket, sslctx )    -- wrap socket
-       if err then
-               out_put( "server.lua: ssl error: ", err )
-               return nil, nil, err    -- fatal error
-       end
-       socket:settimeout( 0 )
-
-       --// private closures of the object //--
-
-       local writequeue = { }    -- buffer for messages to send
-
-       local eol, fatal_send_error, wants_closing
-
-       local sstat, rstat = 0, 0
-
-       --// local import of socket methods //--
-
-       local send = socket.send
-       local receive = socket.receive
-       local close = socket.close
-       --local shutdown = socket.shutdown
-
-       --// public methods of the object //--
-
-       local handler = { }
-
-       handler.getstats = function( )
-               return rstat, sstat
-       end
-
-       handler.listener = function( data, err )
-               return listener( handler, data, err )
-       end
-       handler.ssl = function( )
-               return true
-       end
-       handler.send = function( _, data, i, j )
-                       return send( socket, data, i, j )
-       end
-       handler.receive = function( pattern, prefix )
-                       return receive( socket, pattern, prefix )
-       end
-       handler.shutdown = function( pattern )
-               --return shutdown( socket, pattern )
-       end
-       handler.close = function( closed )
-               if eol and not fatal_send_error then
-                       -- There is data in the buffer, and we haven't experienced
-                       -- an error trying to send yet, so we'll flush the buffer now
-                       handler._dispatchdata();
-                       if eol then
-                               -- and there is *still* data in the buffer
-                               -- we'll give up for now, and close later
-                               wants_closing = true;
-                               return;
-                       end
-               end
-               close( socket )
-               writelen = ( eol and removesocket( writelist, socket, writelen ) ) or writelen
-               readlen = removesocket( readlist, socket, readlen )
-               socketlist[ socket ] = nil
-               out_put "server.lua: closed handler and removed socket from list"
-       end
-       handler.ip = function( )
-               return ip
-       end
-       handler.serverport = function( )
-               return serverport
-       end
-       handler.clientport = function( ) 
-               return clientport
-       end
-
-       handler.write = function( data )
-               if not eol then
-                       writelen = writelen + 1
-                       writelist[ writelen ] = socket
-                       eol = 0
-               end
-               eol = eol + 1
-               writequeue[ eol ] = data
-       end
-       handler.writequeue = function( )
-               return writequeue
-       end
-       handler.socket = function( )
-               return socket
-       end
-       handler.mode = function( )
-               return mode
-       end
-       handler._receivedata = function( )
-               local data, err, part = receive( socket, mode )    -- receive data in "mode"
-               if not err or ( err == "timeout" or err == "wantread" ) then    -- received something
-                       local data = data or part or ""
-                       local count = #data * STAT_UNIT
-                       rstat = rstat + count
-                       receivestat = receivestat + count
-                       --out_put( "server.lua: read data '", data, "', error: ", err )
-                       return dispatch( handler, data, err )
-               else    -- connections was closed or fatal error
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-       handler._dispatchdata = function( )    -- this function writes data to handlers
-               local buffer = table_concat( writequeue, "", 1, eol )
-               local succ, err, byte = send( socket, buffer )
-               local count = ( succ or 0 ) * STAT_UNIT
-               sstat = sstat + count
-               sendstat = sendstat + count
-               out_put( "server.lua: sended '", buffer, "', bytes: ", succ, ", error: ", err, ", part: ", byte, ", to: ", ip, ":", clientport )
-               if succ then    -- sending succesful
-                       --writequeue = { }
-                       eol = nil
-                       writelen = removesocket( writelist, socket, writelen )    -- delete socket from writelist
-                       if wants_closing then
-                               handler.close();
-                       end
-                       return true
-               elseif byte and ( err == "timeout" or err == "wantwrite" ) then    -- want write
-                       buffer = string_sub( buffer, byte + 1, -1 )    -- new buffer
-                       writequeue[ 1 ] = buffer    -- insert new buffer in queue
-                       eol = 1
-                       return true
-               else    -- connection was closed during sending or fatal error
-                       fatal_send_error = true;
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-
-       -- // COMPAT // --
-
-       handler.getIp = handler.ip
-       handler.getPort = handler.clientport
-
-       --// handshake //--
-
-       local wrote
-
-       handler.handshake = coroutine_wrap( function( client )
-                       local err
-                       for i = 1, 10 do    -- 10 handshake attemps
-                               _, err = client:dohandshake( )
-                               if not err then
-                                       out_put( "server.lua: ssl handshake done" )
-                                       writelen = ( wrote and removesocket( writelist, socket, writelen ) ) or writelen
-                                       handler.receivedata = handler._receivedata    -- when handshake is done, replace the handshake function with regular functions
-                                       handler.dispatchdata = handler._dispatchdata
-                                       return dispatch( handler )
-                               else
-                                       out_put( "server.lua: error during ssl handshake: ", err )
-                                       if err == "wantwrite" then
-                                               if wrote == nil then
-                                                       writelen = writelen + 1
-                                                       writelist[ writelen ] = client
-                                                       wrote = true
-                                               end
-                                       end
-                                       coroutine_yield( handler, nil, err )    -- handshake not finished
-                               end
-                       end
-                       _ = err ~= "closed" and close( socket )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false    -- handshake failed
-               end
-       )
-       handler.receivedata = handler.handshake
-       handler.dispatchdata = handler.handshake
-
-       handler.handshake( socket )    -- do handshake
-
-       socketlist[ socket ] = handler
-       readlen = readlen + 1
-       readlist[ readlen ] = socket
-
-       return handler, socket
-end
-
-wraptlsclient = function( listener, socket, ip, serverport, clientport, mode, sslctx )    -- this function wraps a tls cleint
-
-       local dispatch, disconnect = listener.listener, listener.disconnect
-
-       --// transform socket to ssl object //--
-
-       local err
-
-       socket:settimeout( 0 )
-       --// private closures of the object //--
-
-       local writequeue = { }    -- buffer for messages to send
-
-       local eol, fatal_send_error, wants_closing
-
-       local sstat, rstat = 0, 0
-
-       --// local import of socket methods //--
-
-       local send = socket.send
-       local receive = socket.receive
-       local close = socket.close
-       --local shutdown = socket.shutdown
-
-       --// public methods of the object //--
-
-       local handler = { }
-
-       handler.getstats = function( )
-               return rstat, sstat
-       end
-
-       handler.listener = function( data, err )
-               return listener( handler, data, err )
-       end
-       handler.ssl = function( )
-               return false
-       end
-       handler.send = function( _, data, i, j )
-                       return send( socket, data, i, j )
-       end
-       handler.receive = function( pattern, prefix )
-                       return receive( socket, pattern, prefix )
-       end
-       handler.shutdown = function( pattern )
-               --return shutdown( socket, pattern )
-       end
-       handler.close = function( closed )
-               if eol and not fatal_send_error then
-                       -- There is data in the buffer, and we haven't experienced
-                       -- an error trying to send yet, so we'll flush the buffer now
-                       handler._dispatchdata();
-                       if eol then
-                               -- and there is *still* data in the buffer
-                               -- we'll give up for now, and close later
-                               wants_closing = true;
-                               return;
-                       end
-               end
-               close( socket )
-               writelen = ( eol and removesocket( writelist, socket, writelen ) ) or writelen
-               readlen = removesocket( readlist, socket, readlen )
-               socketlist[ socket ] = nil
-               out_put "server.lua: closed handler and removed socket from list"
-       end
-       handler.ip = function( )
-               return ip
-       end
-       handler.serverport = function( )
-               return serverport
-       end
-       handler.clientport = function( ) 
-               return clientport
-       end
-
-       handler.write = function( data )
-               if not eol then
-                       writelen = writelen + 1
-                       writelist[ writelen ] = socket
-                       eol = 0
-               end
-               eol = eol + 1
-               writequeue[ eol ] = data
-       end
-       handler.writequeue = function( )
-               return writequeue
-       end
-       handler.socket = function( )
-               return socket
-       end
-       handler.mode = function( )
-               return mode
-       end
-       handler._receivedata = function( )
-               local data, err, part = receive( socket, mode )    -- receive data in "mode"
-               if not err or ( err == "timeout" or err == "wantread" ) then    -- received something
-                       local data = data or part or ""
-                       local count = #data * STAT_UNIT
-                       rstat = rstat + count
-                       receivestat = receivestat + count
-                       --out_put( "server.lua: read data '", data, "', error: ", err )
-                       return dispatch( handler, data, err )
-               else    -- connections was closed or fatal error
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-       handler._dispatchdata = function( )    -- this function writes data to handlers
-               local buffer = table_concat( writequeue, "", 1, eol )
-               local succ, err, byte = send( socket, buffer )
-               local count = ( succ or 0 ) * STAT_UNIT
-               sstat = sstat + count
-               sendstat = sendstat + count
-               out_put( "server.lua: sended '", buffer, "', bytes: ", succ, ", error: ", err, ", part: ", byte, ", to: ", ip, ":", clientport )
-               if succ then    -- sending succesful
-                       --writequeue = { }
-                       eol = nil
-                       writelen = removesocket( writelist, socket, writelen )    -- delete socket from writelist
-                       if handler.need_tls then
-                               out_put("server.lua: connection is ready for tls handshake");
-                               handler.starttls(true);
-                       end
-                       if wants_closing then
-                               handler.close();
-                       end
-                       return true
-               elseif byte and ( err == "timeout" or err == "wantwrite" ) then    -- want write
-                       buffer = string_sub( buffer, byte + 1, -1 )    -- new buffer
-                       writequeue[ 1 ] = buffer    -- insert new buffer in queue
-                       eol = 1
-                       return true
-               else    -- connection was closed during sending or fatal error
-                       fatal_send_error = true; -- :(
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-
-       handler.receivedata, handler.dispatchdata = handler._receivedata, handler._dispatchdata;
-       -- // COMPAT // --
-
-       handler.getIp = handler.ip
-       handler.getPort = handler.clientport
-
-       --// handshake //--
-
-       local wrote, read
-       
-       handler.starttls = function (now)
-               if not now then out_put("server.lua: we need to do tls, but delaying until later"); handler.need_tls = true; return; end
-               out_put( "server.lua: attempting to start tls on "..tostring(socket) )
-               local oldsocket = socket;
-               socket, err = ssl_wrap( socket, sslctx )    -- wrap socket
-               out_put("sslwrapped socket is "..tostring(socket));
-               if err then
-                       out_put( "server.lua: ssl error: ", err )
-                       return nil, nil, err    -- fatal error
-               end
-               socket:settimeout(0);
-               
-               -- Add the new socket to our system
-               socketlist[ socket ] = handler
-               readlen = readlen + 1
-               readlist[ readlen ] = socket
-               
-               -- Remove traces of the old socket
-               readlen = removesocket( readlist, oldsocket, readlen )
-               socketlist [ oldsocket ] = nil;
-               
-               send = socket.send
-               receive = socket.receive
-               close = socket.close
-               handler.ssl = function( )
-                       return true
-               end
-               handler.send = function( _, data, i, j )
-                       return send( socket, data, i, j )
-               end
-               handler.receive = function( pattern, prefix )
-                       return receive( socket, pattern, prefix )
-               end
-               
-               handler.starttls = nil;
-               handler.need_tls = nil
-               
-                       handler.handshake = coroutine_wrap( function( client )
-                                       local err
-                                       for i = 1, 10 do    -- 10 handshake attemps
-                                               _, err = client:dohandshake( )
-                                               if not err then
-                                                       out_put( "server.lua: ssl handshake done" )
-                                                       writelen = ( wrote and removesocket( writelist, socket, writelen ) ) or writelen
-                                                       handler.receivedata = handler._receivedata    -- when handshake is done, replace the handshake function with regular functions
-                                                       handler.dispatchdata = handler._dispatchdata;
-                                                       return true;
-                                               else
-                                                       out_put( "server.lua: error during ssl handshake: ", err )
-                                                       if err == "wantwrite" then
-                                                               if wrote == nil then
-                                                                       writelen = writelen + 1
-                                                                       writelist[ writelen ] = client
-                                                                       wrote = true
-                                                               end
-                                                       end
-                                                       coroutine_yield( handler, nil, err )    -- handshake not finished
-                                               end
-                                       end
-                                       _ = err ~= "closed" and close( socket )
-                                       handler.close( )
-                                       disconnect( handler, err )
-                                       writequeue = nil
-                                       handler = nil
-                                       return false    -- handshake failed
-                               end
-                       )
-                       handler.receivedata = handler.handshake
-                       handler.dispatchdata = handler.handshake
-                       
-                       handler.handshake( socket )    -- do handshake
-               end
-       socketlist[ socket ] = handler
-       readlen = readlen + 1
-       readlist[ readlen ] = socket
-
-       return handler, socket
-end
-
-wraptcpclient = function( listener, socket, ip, serverport, clientport, mode )    -- this function wraps a socket
-
-       local dispatch, disconnect = listener.listener, listener.disconnect
-
-       --// private closures of the object //--
-
-       local writequeue = { }    -- list for messages to send
-
-       local eol, fatal_send_error, wants_closing
-
-       socket:settimeout(0);
-       
-       local rstat, sstat = 0, 0
-
-       --// local import of socket methods //--
-
-       local send = socket.send
-       local receive = socket.receive
-       local close = socket.close
-       local shutdown = socket.shutdown
-
-       --// public methods of the object //--
-
-       local handler = { }
-
-       handler.getstats = function( )
-               return rstat, sstat
-       end
-
-       handler.listener = function( data, err )
-               return listener( handler, data, err )
-       end
-       handler.ssl = function( )
-               return false
-       end
-       handler.send = function( _, data, i, j )
-                       return send( socket, data, i, j )
-       end
-       handler.receive = function( pattern, prefix )
-                       return receive( socket, pattern, prefix )
-       end
-       handler.shutdown = function( pattern )
-               return shutdown( socket, pattern )
-       end
-       handler.close = function( closed )
-               if eol and not fatal_send_error then
-                       -- There is data in the buffer, and we haven't experienced
-                       -- an error trying to send yet, so we'll flush the buffer now
-                       handler.dispatchdata();
-                       if eol then
-                               -- and there is *still* data in the buffer
-                               -- we'll give up for now, and close later
-                               wants_closing = true;
-                               return;
-                       end
-               end
-               _ = not closed and shutdown( socket )
-               _ = not closed and close( socket )
-               writelen = ( eol and removesocket( writelist, socket, writelen ) ) or writelen
-               readlen = removesocket( readlist, socket, readlen )
-               socketlist[ socket ] = nil
-               out_put "server.lua: closed handler and removed socket from list"
-       end
-       handler.ip = function( )
-               return ip
-       end
-       handler.serverport = function( )
-               return serverport
-       end
-       handler.clientport = function( ) 
-               return clientport
-       end
-       handler.write = function( data )
-               if not eol then
-                       writelen = writelen + 1
-                       writelist[ writelen ] = socket
-                       eol = 0
-               end
-               eol = eol + 1
-               writequeue[ eol ] = data
-       end
-       handler.writequeue = function( )
-               return writequeue
-       end
-       handler.socket = function( )
-               return socket
-       end
-       handler.mode = function( )
-               return mode
-       end
-       
-       handler.receivedata = function( )
-               local data, err, part = receive( socket, mode )    -- receive data in "mode"
-               if not err or ( err == "timeout" or err == "wantread" ) then    -- received something
-                       local data = data or part or ""
-                       local count = #data * STAT_UNIT
-                       rstat = rstat + count
-                       receivestat = receivestat + count
-                       --out_put( "server.lua: read data '", data, "', error: ", err )
-                       return dispatch( handler, data, err )
-               else    -- connections was closed or fatal error
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-       
-       handler.dispatchdata = function( )    -- this function writes data to handlers
-               local buffer = table_concat( writequeue, "", 1, eol )
-               local succ, err, byte = send( socket, buffer )
-               local count = ( succ or 0 ) * STAT_UNIT
-               sstat = sstat + count
-               sendstat = sendstat + count
-               out_put( "server.lua: sended '", buffer, "', bytes: ", succ, ", error: ", err, ", part: ", byte, ", to: ", ip, ":", clientport )
-               if succ then    -- sending succesful
-                       --writequeue = { }
-                       eol = nil
-                       writelen = removesocket( writelist, socket, writelen )    -- delete socket from writelist
-                       if wants_closing then
-                               handler.close();
-                       end
-                       return true
-               elseif byte and ( err == "timeout" or err == "wantwrite" ) then    -- want write
-                       buffer = string_sub( buffer, byte + 1, -1 )    -- new buffer
-                       writequeue[ 1 ] = buffer    -- insert new buffer in queue
-                       eol = 1
-                       return true
-               else    -- connection was closed during sending or fatal error
-                       fatal_send_error = true; -- :'-(
-                       out_put( "server.lua: client ", ip, ":", clientport, " error: ", err )
-                       handler.close( )
-                       disconnect( handler, err )
-                       writequeue = nil
-                       handler = nil
-                       return false
-               end
-       end
-
-       -- // COMPAT // --
-
-       handler.getIp = handler.ip
-       handler.getPort = handler.clientport
-
-       socketlist[ socket ] = handler
-       readlen = readlen + 1
-       readlist[ readlen ] = socket
-
-       return handler, socket
-end
-
-addtimer = function( listener )
-       timelistener[ #timelistener + 1 ] = listener
-end
-
-firetimer = function( listener )
-       for i, listener in ipairs( timelistener ) do
-               listener( )
-       end
-end
-
-addserver = function( listeners, port, addr, mode, sslctx )    -- this function provides a way for other scripts to reg a server
-       local err
-       if type( listeners ) ~= "table" then
-               err = "invalid listener table"
-       else
-               for name, func in pairs( listeners ) do
-                       if type( func ) ~= "function" then
-                               --err = "invalid listener function"
-                               break
-                       end
-               end
-       end
-       if not type( port ) == "number" or not ( port >= 0 and port <= 65535 ) then
-               err = "invalid port"
-       elseif listener[ port ] then
-               err=  "listeners on port '" .. port .. "' already exist"
-       elseif sslctx and not luasec then
-               err = "luasec not found"
-       end
-       if err then
-               out_error( "server.lua: ", err )
-               return nil, err
-       end
-       addr = addr or "*"
-       local server, err = socket_bind( addr, port )
-       if err then
-               out_error( "server.lua: ", err )
-               return nil, err
-       end
-       local handler, err = wrapserver( listeners, server, addr, port, mode, sslctx )    -- wrap new server socket
-       if not handler then
-               server:close( )
-               return nil, err
-       end
-       server:settimeout( 0 )
-       readlen = readlen + 1
-       readlist[ readlen ] = server
-       listener[ port ] = listeners
-       socketlist[ server ] = handler
-       out_put( "server.lua: new server listener on ", addr, ":", port )
-       return true
-end
-
-removesocket = function( tbl, socket, len )    -- this function removes sockets from a list
-       for i, target in ipairs( tbl ) do
-               if target == socket then
-                       len = len - 1
-                       table_remove( tbl, i )
-                       return len
-               end
-       end
-       return len
-end
-
-closeall = function( )
-       for sock, handler in pairs( socketlist ) do
-               handler.shutdown( )
-               handler.close( )
-               socketlist[ sock ] = nil
-       end
-       writelist, readlist, socketlist = { }, { }, { }
-end
-
-closesocket = function( socket )
-       writelen = removesocket( writelist, socket, writelen )
-       readlen = removesocket( readlist, socket, readlen )
-       socketlist[ socket ] = nil
-       socket:close( )
-end
-
-loop = function( )    -- this is the main loop of the program
-       --signal_set( "hub", "run" )
-       repeat
-               local read, write, err = socket_select( readlist, writelist, 1 )    -- 1 sec timeout, nice for timers
-               for i, socket in ipairs( write ) do    -- send data waiting in writequeues
-                       local handler = socketlist[ socket ]
-                       if handler then
-                               handler.dispatchdata( )
-                       else
-                               closesocket( socket )
-                               out_put "server.lua: found no handler and closed socket (writelist)"    -- this should not happen
-                       end
-               end
-               for i, socket in ipairs( read ) do    -- receive data
-                       local handler = socketlist[ socket ]
-                       if handler then
-                               handler.receivedata( )
-                       else
-                               closesocket( socket )
-                               out_put "server.lua: found no handler and closed socket (readlist)"    -- this can happen
-                       end
-               end
-               firetimer( )
-       until false
-       return
-end
-
-----------------------------------// BEGIN //--
-
-----------------------------------// PUBLIC INTERFACE //--
-
-return {
-
-       add = addserver,
-       loop = loop,
-       stats = stats,
-       closeall = closeall,
-       addtimer = addtimer,
-       wraptcpclient = wraptcpclient,
-       wraptlsclient = wraptlsclient,
-}
+--[[\r
+\r
+        server.lua by blastbeat\r
+\r
+        - this script contains the server loop of the program\r
+        - other scripts can reg a server here\r
+\r
+]]--\r
+\r
+-- // wrapping luadch stuff // --\r
+\r
+local use = function( what )\r
+    return _G[ what ]\r
+end\r
+local clean = function( tbl )\r
+    for i, k in pairs( tbl ) do\r
+        tbl[ i ] = nil\r
+    end\r
+end\r
+\r
+local log, table_concat = require ("util.logger").init("socket"), table.concat;\r
+local out_put = function (...) return log("debug", table_concat{...}); end\r
+local out_error = function (...) return log("warn", table_concat{...}); end\r
+local mem_free = collectgarbage\r
+\r
+----------------------------------// DECLARATION //--\r
+\r
+--// constants //--\r
+\r
+local STAT_UNIT = 1    -- byte\r
+\r
+--// lua functions //--\r
+\r
+local type = use "type"\r
+local pairs = use "pairs"\r
+local ipairs = use "ipairs"\r
+local tostring = use "tostring"\r
+local collectgarbage = use "collectgarbage"\r
+\r
+--// lua libs //--\r
+\r
+local os = use "os"\r
+local table = use "table"\r
+local string = use "string"\r
+local coroutine = use "coroutine"\r
+\r
+--// lua lib methods //--\r
+\r
+local os_time = os.time\r
+local os_difftime = os.difftime\r
+local table_concat = table.concat\r
+local table_remove = table.remove\r
+local string_len = string.len\r
+local string_sub = string.sub\r
+local coroutine_wrap = coroutine.wrap\r
+local coroutine_yield = coroutine.yield\r
+\r
+--// extern libs //--\r
+\r
+local luasec = select( 2, pcall( require, "ssl" ) )\r
+local luasocket = require "socket"\r
+\r
+--// extern lib methods //--\r
+\r
+local ssl_wrap = ( luasec and luasec.wrap )\r
+local socket_bind = luasocket.bind\r
+local socket_sleep = luasocket.sleep\r
+local socket_select = luasocket.select\r
+local ssl_newcontext = ( luasec and luasec.newcontext )\r
+\r
+--// functions //--\r
+\r
+local id\r
+local loop\r
+local stats\r
+local idfalse\r
+local addtimer\r
+local closeall\r
+local addserver\r
+local getserver\r
+local wrapserver\r
+local getsettings\r
+local closesocket\r
+local removesocket\r
+local removeserver\r
+local changetimeout\r
+local wrapconnection\r
+local changesettings\r
+\r
+--// tables //--\r
+\r
+local _server\r
+local _readlist\r
+local _timerlist\r
+local _sendlist\r
+local _socketlist\r
+local _closelist\r
+local _readtimes\r
+local _writetimes\r
+\r
+--// simple data types //--\r
+\r
+local _\r
+local _readlistlen\r
+local _sendlistlen\r
+local _timerlistlen\r
+\r
+local _sendtraffic\r
+local _readtraffic\r
+\r
+local _selecttimeout\r
+local _sleeptime\r
+\r
+local _starttime\r
+local _currenttime\r
+\r
+local _maxsendlen\r
+local _maxreadlen\r
+\r
+local _checkinterval\r
+local _sendtimeout\r
+local _readtimeout\r
+\r
+local _cleanqueue\r
+\r
+local _timer\r
+\r
+local _maxclientsperserver\r
+\r
+----------------------------------// DEFINITION //--\r
+\r
+_server = { }    -- key = port, value = table; list of listening servers\r
+_readlist = { }    -- array with sockets to read from\r
+_sendlist = { }    -- arrary with sockets to write to\r
+_timerlist = { }    -- array of timer functions\r
+_socketlist = { }    -- key = socket, value = wrapped socket (handlers)\r
+_readtimes = { }   -- key = handler, value = timestamp of last data reading\r
+_writetimes = { }   -- key = handler, value = timestamp of last data writing/sending\r
+_closelist = { }    -- handlers to close\r
+\r
+_readlistlen = 0    -- length of readlist\r
+_sendlistlen = 0    -- length of sendlist\r
+_timerlistlen = 0    -- lenght of timerlist\r
+\r
+_sendtraffic = 0    -- some stats\r
+_readtraffic = 0\r
+\r
+_selecttimeout = 1    -- timeout of socket.select\r
+_sleeptime = 0    -- time to wait at the end of every loop\r
+\r
+_maxsendlen = 51000 * 1024    -- max len of send buffer\r
+_maxreadlen = 25000 * 1024    -- max len of read buffer\r
+\r
+_checkinterval = 1200000    -- interval in secs to check idle clients\r
+_sendtimeout = 60000    -- allowed send idle time in secs\r
+_readtimeout = 6 * 60 * 60    -- allowed read idle time in secs\r
+\r
+_cleanqueue = false    -- clean bufferqueue after using\r
+\r
+_maxclientsperserver = 1000\r
+\r
+----------------------------------// PRIVATE //--\r
+\r
+wrapserver = function( listeners, socket, ip, serverport, pattern, sslctx, maxconnections, startssl )    -- this function wraps a server\r
+\r
+    maxconnections = maxconnections or _maxclientsperserver\r
+\r
+    local connections = 0\r
+\r
+    local dispatch, disconnect = listeners.incoming or listeners.listener, listeners.disconnect\r
+\r
+    local err\r
+\r
+    local ssl = false\r
+\r
+    if sslctx then\r
+        if not ssl_newcontext then\r
+            return nil, "luasec not found"\r
+        end\r
+        if type( sslctx ) ~= "table" then\r
+            out_error "server.lua: wrong server sslctx"\r
+            return nil, "wrong server sslctx"\r
+        end\r
+        sslctx, err = ssl_newcontext( sslctx )\r
+        if not sslctx then\r
+            err = err or "wrong sslctx parameters"\r
+            out_error( "server.lua: ", err )\r
+            return nil, err\r
+        end\r
+        ssl = true\r
+    else\r
+       out_put("server.lua: ", "ssl not enabled on ", serverport);\r
+    end\r
+\r
+    local accept = socket.accept\r
+\r
+    --// public methods of the object //--\r
+\r
+    local handler = { }\r
+\r
+    handler.shutdown = function( ) end\r
+\r
+    handler.ssl = function( )\r
+        return ssl\r
+    end\r
+    handler.remove = function( )\r
+        connections = connections - 1\r
+    end\r
+    handler.close = function( )\r
+        for _, handler in pairs( _socketlist ) do\r
+            if handler.serverport == serverport then\r
+                handler.disconnect( handler, "server closed" )\r
+                handler.close( true )\r
+            end\r
+        end\r
+        socket:close( )\r
+        _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )\r
+        _readlistlen = removesocket( _readlist, socket, _readlistlen )\r
+        _socketlist[ socket ] = nil\r
+        handler = nil\r
+        socket = nil\r
+        mem_free( )\r
+        out_put "server.lua: closed server handler and removed sockets from list"\r
+    end\r
+    handler.ip = function( )\r
+        return ip\r
+    end\r
+    handler.serverport = function( )\r
+        return serverport\r
+    end\r
+    handler.socket = function( )\r
+        return socket\r
+    end\r
+    handler.readbuffer = function( )\r
+        if connections > maxconnections then\r
+            out_put( "server.lua: refused new client connection: server full" )\r
+            return false\r
+        end\r
+        local client, err = accept( socket )    -- try to accept\r
+        if client then\r
+            local ip, clientport = client:getpeername( )\r
+            client:settimeout( 0 )\r
+            local handler, client, err = wrapconnection( handler, listeners, client, ip, serverport, clientport, pattern, sslctx, startssl )    -- wrap new client socket\r
+            if err then    -- error while wrapping ssl socket\r
+                return false\r
+            end\r
+            connections = connections + 1\r
+            out_put( "server.lua: accepted new client connection from ", tostring(ip), ":", tostring(clientport), " to ", tostring(serverport))\r
+            return dispatch( handler )\r
+        elseif err then    -- maybe timeout or something else\r
+            out_put( "server.lua: error with new client connection: ", tostring(err) )\r
+            return false\r
+        end\r
+    end\r
+    return handler\r
+end\r
+\r
+wrapconnection = function( server, listeners, socket, ip, serverport, clientport, pattern, sslctx, startssl )    -- this function wraps a client to a handler object\r
+\r
+    socket:settimeout( 0 )\r
+\r
+    --// local import of socket methods //--\r
+\r
+    local send\r
+    local receive\r
+    local shutdown\r
+\r
+    --// private closures of the object //--\r
+\r
+    local ssl\r
+\r
+    local dispatch = listeners.incoming or listeners.listener\r
+    local disconnect = listeners.disconnect\r
+\r
+    local bufferqueue = { }    -- buffer array\r
+    local bufferqueuelen = 0    -- end of buffer array\r
+\r
+    local toclose\r
+    local fatalerror\r
+    local needtls\r
+\r
+    local bufferlen = 0\r
+\r
+    local noread = false\r
+    local nosend = false\r
+\r
+    local sendtraffic, readtraffic = 0, 0\r
+\r
+    local maxsendlen = _maxsendlen\r
+    local maxreadlen = _maxreadlen\r
+\r
+    --// public methods of the object //--\r
+\r
+    local handler = bufferqueue    -- saves a table ^_^\r
+\r
+    handler.dispatch = function( )\r
+        return dispatch\r
+    end\r
+    handler.disconnect = function( )\r
+        return disconnect\r
+    end\r
+    handler.setlistener = function( listeners )\r
+        dispatch = listeners.incoming\r
+        disconnect = listeners.disconnect\r
+    end\r
+    handler.getstats = function( )\r
+        return readtraffic, sendtraffic\r
+    end\r
+    handler.ssl = function( )\r
+        return ssl\r
+    end\r
+    handler.send = function( _, data, i, j )\r
+        return send( socket, data, i, j )\r
+    end\r
+    handler.receive = function( pattern, prefix )\r
+        return receive( socket, pattern, prefix )\r
+    end\r
+    handler.shutdown = function( pattern )\r
+        return shutdown( socket, pattern )\r
+    end\r
+    handler.close = function( forced )\r
+        if not handler then return true; end\r
+        _readlistlen = removesocket( _readlist, socket, _readlistlen )\r
+        _readtimes[ handler ] = nil\r
+        if bufferqueuelen ~= 0 then\r
+            if not ( forced or fatalerror ) then\r
+                handler.sendbuffer( )\r
+                if bufferqueuelen ~= 0 then   -- try again...\r
+                    if handler then\r
+                        handler.write = nil    -- ... but no further writing allowed\r
+                    end\r
+                    toclose = true\r
+                    return false\r
+                end\r
+            else\r
+                send( socket, table_concat( bufferqueue, "", 1, bufferqueuelen ), 1, bufferlen )    -- forced send\r
+            end\r
+        end\r
+        _ = shutdown and shutdown( socket )\r
+        socket:close( )\r
+        _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )\r
+        _socketlist[ socket ] = nil\r
+        if handler then\r
+            _writetimes[ handler ] = nil\r
+            _closelist[ handler ] = nil\r
+            handler = nil\r
+        end\r
+        socket = nil\r
+        mem_free( )\r
+       if server then\r
+               server.remove( )\r
+       end\r
+        out_put "server.lua: closed client handler and removed socket from list"\r
+        return true\r
+    end\r
+    handler.ip = function( )\r
+        return ip\r
+    end\r
+    handler.serverport = function( )\r
+        return serverport\r
+    end\r
+    handler.clientport = function( )\r
+        return clientport\r
+    end\r
+    local write = function( data )\r
+        bufferlen = bufferlen + string_len( data )\r
+        if bufferlen > maxsendlen then\r
+            _closelist[ handler ] = "send buffer exceeded"   -- cannot close the client at the moment, have to wait to the end of the cycle\r
+            handler.write = idfalse    -- dont write anymore\r
+            return false\r
+        elseif socket and not _sendlist[ socket ] then\r
+            _sendlistlen = _sendlistlen + 1\r
+            _sendlist[ _sendlistlen ] = socket\r
+            _sendlist[ socket ] = _sendlistlen\r
+        end\r
+        bufferqueuelen = bufferqueuelen + 1\r
+        bufferqueue[ bufferqueuelen ] = data\r
+        if handler then\r
+               _writetimes[ handler ] = _writetimes[ handler ] or _currenttime\r
+        end\r
+        return true\r
+    end\r
+    handler.write = write\r
+    handler.bufferqueue = function( )\r
+        return bufferqueue\r
+    end\r
+    handler.socket = function( )\r
+        return socket\r
+    end\r
+    handler.pattern = function( new )\r
+        pattern = new or pattern\r
+        return pattern\r
+    end\r
+    handler.setsend = function ( newsend )\r
+        send = newsend or send\r
+        return send\r
+    end\r
+    handler.bufferlen = function( readlen, sendlen )\r
+        maxsendlen = sendlen or maxsendlen\r
+        maxreadlen = readlen or maxreadlen\r
+        return maxreadlen, maxsendlen\r
+    end\r
+    handler.lock = function( switch )\r
+        if switch == true then\r
+            handler.write = idfalse\r
+            local tmp = _sendlistlen\r
+            _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )\r
+            _writetimes[ handler ] = nil\r
+            if _sendlistlen ~= tmp then\r
+                nosend = true\r
+            end\r
+            tmp = _readlistlen\r
+            _readlistlen = removesocket( _readlist, socket, _readlistlen )\r
+            _readtimes[ handler ] = nil\r
+            if _readlistlen ~= tmp then\r
+                noread = true\r
+            end\r
+        elseif switch == false then\r
+            handler.write = write\r
+            if noread then\r
+                noread = false\r
+                _readlistlen = _readlistlen + 1\r
+                _readlist[ socket ] = _readlistlen\r
+                _readlist[ _readlistlen ] = socket\r
+                _readtimes[ handler ] = _currenttime\r
+            end\r
+            if nosend then\r
+                nosend = false\r
+                write( "" )\r
+            end\r
+        end\r
+        return noread, nosend\r
+    end\r
+    local _readbuffer = function( )    -- this function reads data\r
+        local buffer, err, part = receive( socket, pattern )    -- receive buffer with "pattern"\r
+        if not err or ( err == "timeout" or err == "wantread" ) then    -- received something\r
+            local buffer = buffer or part or ""\r
+            local len = string_len( buffer )\r
+            if len > maxreadlen then\r
+                disconnect( handler, "receive buffer exceeded" )\r
+                handler.close( true )\r
+                return false\r
+            end\r
+            local count = len * STAT_UNIT\r
+            readtraffic = readtraffic + count\r
+            _readtraffic = _readtraffic + count\r
+            _readtimes[ handler ] = _currenttime\r
+            --out_put( "server.lua: read data '", buffer, "', error: ", err )\r
+            return dispatch( handler, buffer, err )\r
+        else    -- connections was closed or fatal error\r
+            out_put( "server.lua: client ", tostring(ip), ":", tostring(clientport), " error: ", tostring(err) )\r
+            fatalerror = true\r
+            disconnect( handler, err )\r
+           _ = handler and handler.close( )\r
+            return false\r
+        end\r
+    end\r
+    local _sendbuffer = function( )    -- this function sends data\r
+        local buffer = table_concat( bufferqueue, "", 1, bufferqueuelen )\r
+        local succ, err, byte = send( socket, buffer, 1, bufferlen )\r
+        local count = ( succ or byte or 0 ) * STAT_UNIT\r
+        sendtraffic = sendtraffic + count\r
+        _sendtraffic = _sendtraffic + count\r
+        _ = _cleanqueue and clean( bufferqueue )\r
+        --out_put( "server.lua: sended '", buffer, "', bytes: ", tostring(succ), ", error: ", tostring(err), ", part: ", tostring(byte), ", to: ", tostring(ip), ":", tostring(clientport) )\r
+        if succ then    -- sending succesful\r
+            bufferqueuelen = 0\r
+            bufferlen = 0\r
+            _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )    -- delete socket from writelist\r
+            _ = needtls and handler.starttls(true)\r
+            _writetimes[ handler ] = nil\r
+           _ = toclose and handler.close( )\r
+            return true\r
+        elseif byte and ( err == "timeout" or err == "wantwrite" ) then    -- want write\r
+            buffer = string_sub( buffer, byte + 1, bufferlen )    -- new buffer\r
+            bufferqueue[ 1 ] = buffer    -- insert new buffer in queue\r
+            bufferqueuelen = 1\r
+            bufferlen = bufferlen - byte\r
+            _writetimes[ handler ] = _currenttime\r
+            return true\r
+        else    -- connection was closed during sending or fatal error\r
+            out_put( "server.lua: client ", tostring(ip), ":", tostring(clientport), " error: ", tostring(err) )\r
+            fatalerror = true\r
+            disconnect( handler, err )\r
+            _ = handler and handler.close( )\r
+            return false\r
+        end\r
+    end\r
+\r
+    if sslctx then    -- ssl?\r
+        ssl = true\r
+        local wrote\r
+        local read\r
+        local handshake = coroutine_wrap( function( client )    -- create handshake coroutine\r
+                local err\r
+                for i = 1, 10 do    -- 10 handshake attemps\r
+                    _sendlistlen = ( wrote and removesocket( _sendlist, socket, _sendlistlen ) ) or _sendlistlen\r
+                    _readlistlen = ( read and removesocket( _readlist, socket, _readlistlen ) ) or _readlistlen\r
+                    read, wrote = nil, nil\r
+                    _, err = client:dohandshake( )\r
+                    if not err then\r
+                        out_put( "server.lua: ssl handshake done" )\r
+                        handler.readbuffer = _readbuffer    -- when handshake is done, replace the handshake function with regular functions\r
+                        handler.sendbuffer = _sendbuffer\r
+                        -- return dispatch( handler )\r
+                        return true\r
+                    else\r
+                        out_put( "server.lua: error during ssl handshake: ", tostring(err) )\r
+                        if err == "wantwrite" and not wrote then\r
+                            _sendlistlen = _sendlistlen + 1\r
+                            _sendlist[ _sendlistlen ] = client\r
+                            wrote = true\r
+                        elseif err == "wantread" and not read then\r
+                                _readlistlen = _readlistlen + 1\r
+                                _readlist [ _readlistlen ] = client\r
+                                read = true\r
+                        else\r
+                               break;\r
+                        end\r
+                        --coroutine_yield( handler, nil, err )    -- handshake not finished\r
+                        coroutine_yield( )\r
+                    end\r
+                end\r
+                disconnect( handler, "ssl handshake failed" )\r
+                handler.close( true )    -- forced disconnect\r
+                return false    -- handshake failed\r
+            end\r
+        )\r
+        if startssl then    -- ssl now?\r
+            --out_put("server.lua: ", "starting ssl handshake")\r
+           local err\r
+            socket, err = ssl_wrap( socket, sslctx )    -- wrap socket\r
+            if err then\r
+                out_put( "server.lua: ssl error: ", tostring(err) )\r
+                mem_free( )\r
+                return nil, nil, err    -- fatal error\r
+            end\r
+            socket:settimeout( 0 )\r
+            handler.readbuffer = handshake\r
+            handler.sendbuffer = handshake\r
+            handshake( socket )    -- do handshake\r
+        else\r
+            handler.starttls = function( now )\r
+                if not now then\r
+                    --out_put "server.lua: we need to do tls, but delaying until later"\r
+                    needtls = true\r
+                    return\r
+                end\r
+                --out_put( "server.lua: attempting to start tls on " .. tostring( socket ) )\r
+                local oldsocket, err = socket\r
+                socket, err = ssl_wrap( socket, sslctx )    -- wrap socket\r
+                --out_put( "server.lua: sslwrapped socket is " .. tostring( socket ) )\r
+                if err then\r
+                    out_put( "server.lua: error while starting tls on client: ", tostring(err) )\r
+                    return nil, err    -- fatal error\r
+                end\r
+\r
+                socket:settimeout( 0 )\r
+\r
+                -- add the new socket to our system\r
+\r
+                send = socket.send\r
+                receive = socket.receive\r
+                shutdown = id\r
+\r
+                _socketlist[ socket ] = handler\r
+                _readlistlen = _readlistlen + 1\r
+                _readlist[ _readlistlen ] = socket\r
+                _readlist[ socket ] = _readlistlen\r
+\r
+                -- remove traces of the old socket\r
+\r
+                _readlistlen = removesocket( _readlist, oldsocket, _readlistlen )\r
+                _sendlistlen = removesocket( _sendlist, oldsocket, _sendlistlen )\r
+                _socketlist[ oldsocket ] = nil\r
+\r
+                handler.starttls = nil\r
+                needtls = nil\r
+\r
+                handler.readbuffer = handshake\r
+                handler.sendbuffer = handshake\r
+                handshake( socket )    -- do handshake\r
+            end\r
+            handler.readbuffer = _readbuffer\r
+            handler.sendbuffer = _sendbuffer\r
+        end\r
+    else    -- normal connection\r
+        ssl = false\r
+        handler.readbuffer = _readbuffer\r
+        handler.sendbuffer = _sendbuffer\r
+    end\r
+\r
+    send = socket.send\r
+    receive = socket.receive\r
+    shutdown = ( ssl and id ) or socket.shutdown\r
+\r
+    _socketlist[ socket ] = handler\r
+    _readlistlen = _readlistlen + 1\r
+    _readlist[ _readlistlen ] = socket\r
+    _readlist[ socket ] = _readlistlen\r
+\r
+    return handler, socket\r
+end\r
+\r
+id = function( )\r
+end\r
+\r
+idfalse = function( )\r
+    return false\r
+end\r
+\r
+removesocket = function( list, socket, len )    -- this function removes sockets from a list ( copied from copas )\r
+    local pos = list[ socket ]\r
+    if pos then\r
+        list[ socket ] = nil\r
+        local last = list[ len ]\r
+        list[ len ] = nil\r
+        if last ~= socket then\r
+            list[ last ] = pos\r
+            list[ pos ] = last\r
+        end\r
+        return len - 1\r
+    end\r
+    return len\r
+end\r
+\r
+closesocket = function( socket )\r
+    _sendlistlen = removesocket( _sendlist, socket, _sendlistlen )\r
+    _readlistlen = removesocket( _readlist, socket, _readlistlen )\r
+    _socketlist[ socket ] = nil\r
+    socket:close( )\r
+    mem_free( )\r
+end\r
+\r
+----------------------------------// PUBLIC //--\r
+\r
+addserver = function( listeners, port, addr, pattern, sslctx, maxconnections, startssl )    -- this function provides a way for other scripts to reg a server\r
+    local err\r
+    --out_put("server.lua: autossl on ", port, " is ", startssl)\r
+    if type( listeners ) ~= "table" then\r
+        err = "invalid listener table"\r
+    end\r
+    if not type( port ) == "number" or not ( port >= 0 and port <= 65535 ) then\r
+        err = "invalid port"\r
+    elseif _server[ port ] then\r
+        err =  "listeners on port '" .. port .. "' already exist"\r
+    elseif sslctx and not luasec then\r
+        err = "luasec not found"\r
+    end\r
+    if err then\r
+        out_error( "server.lua: ", err )\r
+        return nil, err\r
+    end\r
+    addr = addr or "*"\r
+    local server, err = socket_bind( addr, port )\r
+    if err then\r
+        out_error( "server.lua: ", err )\r
+        return nil, err\r
+    end\r
+    local handler, err = wrapserver( listeners, server, addr, port, pattern, sslctx, maxconnections, startssl )    -- wrap new server socket\r
+    if not handler then\r
+        server:close( )\r
+        return nil, err\r
+    end\r
+    server:settimeout( 0 )\r
+    _readlistlen = _readlistlen + 1\r
+    _readlist[ _readlistlen ] = server\r
+    _server[ port ] = handler\r
+    _socketlist[ server ] = handler\r
+    out_put( "server.lua: new server listener on '", addr, ":", port, "'" )\r
+    return handler\r
+end\r
+\r
+getserver = function ( port )\r
+       return _server[ port ];\r
+end\r
+\r
+removeserver = function( port )\r
+    local handler = _server[ port ]\r
+    if not handler then\r
+        return nil, "no server found on port '" .. tostring( port ) "'"\r
+    end\r
+    handler.close( )\r
+    return true\r
+end\r
+\r
+closeall = function( )\r
+    for _, handler in pairs( _socketlist ) do\r
+        handler.close( )\r
+        _socketlist[ _ ] = nil\r
+    end\r
+    _readlistlen = 0\r
+    _sendlistlen = 0\r
+    _timerlistlen = 0\r
+    _server = { }\r
+    _readlist = { }\r
+    _sendlist = { }\r
+    _timerlist = { }\r
+    _socketlist = { }\r
+    mem_free( )\r
+end\r
+\r
+getsettings = function( )\r
+    return  _selecttimeout, _sleeptime, _maxsendlen, _maxreadlen, _checkinterval, _sendtimeout, _readtimeout, _cleanqueue, _maxclientsperserver\r
+end\r
+\r
+changesettings = function( new )\r
+    if type( new ) ~= "table" then\r
+        return nil, "invalid settings table"\r
+    end\r
+    _selecttimeout = tonumber( new.timeout ) or _selecttimeout\r
+    _sleeptime = tonumber( new.sleeptime ) or _sleeptime\r
+    _maxsendlen = tonumber( new.maxsendlen ) or _maxsendlen\r
+    _maxreadlen = tonumber( new.maxreadlen ) or _maxreadlen\r
+    _checkinterval = tonumber( new.checkinterval ) or _checkinterval\r
+    _sendtimeout = tonumber( new.sendtimeout ) or _sendtimeout\r
+    _readtimeout = tonumber( new.readtimeout ) or _readtimeout\r
+    _cleanqueue = new.cleanqueue\r
+    _maxclientsperserver = new._maxclientsperserver or _maxclientsperserver\r
+    return true\r
+end\r
+\r
+addtimer = function( listener )\r
+    if type( listener ) ~= "function" then\r
+        return nil, "invalid listener function"\r
+    end\r
+    _timerlistlen = _timerlistlen + 1\r
+    _timerlist[ _timerlistlen ] = listener\r
+    return true\r
+end\r
+\r
+stats = function( )\r
+    return _readtraffic, _sendtraffic, _readlistlen, _sendlistlen, _timerlistlen\r
+end\r
+\r
+local dontstop = true; -- thinking about tomorrow, ...\r
+\r
+setquitting = function (quit)\r
+       dontstop = not quit;\r
+       return;\r
+end\r
+\r
+loop = function( )    -- this is the main loop of the program\r
+    while dontstop do\r
+        local read, write, err = socket_select( _readlist, _sendlist, _selecttimeout )\r
+        for i, socket in ipairs( write ) do    -- send data waiting in writequeues\r
+            local handler = _socketlist[ socket ]\r
+            if handler then\r
+                handler.sendbuffer( )\r
+            else\r
+                closesocket( socket )\r
+                out_put "server.lua: found no handler and closed socket (writelist)"    -- this should not happen\r
+            end\r
+        end\r
+        for i, socket in ipairs( read ) do    -- receive data\r
+            local handler = _socketlist[ socket ]\r
+            if handler then\r
+                handler.readbuffer( )\r
+            else\r
+                closesocket( socket )\r
+                out_put "server.lua: found no handler and closed socket (readlist)"    -- this can happen\r
+            end\r
+        end\r
+        for handler, err in pairs( _closelist ) do\r
+            handler.disconnect( )( handler, err )\r
+            handler.close( true )    -- forced disconnect\r
+        end\r
+        clean( _closelist )\r
+        _currenttime = os_time( )\r
+        if os_difftime( _currenttime - _timer ) >= 1 then\r
+            for i = 1, _timerlistlen do\r
+                _timerlist[ i ]( )    -- fire timers\r
+            end\r
+            _timer = _currenttime\r
+        end\r
+        socket_sleep( _sleeptime )    -- wait some time\r
+        --collectgarbage( )\r
+    end\r
+    return "quitting"\r
+end\r
+\r
+--// EXPERIMENTAL //--\r
+\r
+local wrapclient = function( socket, ip, serverport, listeners, pattern, sslctx, startssl )\r
+    local handler = wrapconnection( nil, listeners, socket, ip, serverport, "clientport", pattern, sslctx, startssl )\r
+    _socketlist[ socket ] = handler\r
+    _sendlistlen = _sendlistlen + 1\r
+    _sendlist[ _sendlistlen ] = socket\r
+    _sendlist[ socket ] = _sendlistlen\r
+    return handler, socket\r
+end\r
+\r
+local addclient = function( address, port, listeners, pattern, sslctx, startssl )\r
+    local client, err = luasocket.tcp( )\r
+    if err then\r
+        return nil, err\r
+    end\r
+    client:settimeout( 0 )\r
+    _, err = client:connect( address, port )\r
+    if err then    -- try again\r
+        local handler = wrapclient( client, address, port, listeners )\r
+    else\r
+        wrapconnection( nil, listeners, client, address, port, "clientport", pattern, sslctx, startssl )\r
+    end\r
+end\r
+\r
+--// EXPERIMENTAL //--\r
+\r
+----------------------------------// BEGIN //--\r
+\r
+use "setmetatable" ( _socketlist, { __mode = "k" } )\r
+use "setmetatable" ( _readtimes, { __mode = "k" } )\r
+use "setmetatable" ( _writetimes, { __mode = "k" } )\r
+\r
+_timer = os_time( )\r
+_starttime = os_time( )\r
+\r
+addtimer( function( )\r
+        local difftime = os_difftime( _currenttime - _starttime )\r
+        if difftime > _checkinterval then\r
+            _starttime = _currenttime\r
+            for handler, timestamp in pairs( _writetimes ) do\r
+                if os_difftime( _currenttime - timestamp ) > _sendtimeout then\r
+                    --_writetimes[ handler ] = nil\r
+                    handler.disconnect( )( handler, "send timeout" )\r
+                    handler.close( true )    -- forced disconnect\r
+                end\r
+            end\r
+            for handler, timestamp in pairs( _readtimes ) do\r
+                if os_difftime( _currenttime - timestamp ) > _readtimeout then\r
+                    --_readtimes[ handler ] = nil\r
+                    handler.disconnect( )( handler, "read timeout" )\r
+                    handler.close( )    -- forced disconnect?\r
+                end\r
+            end\r
+        end\r
+    end\r
+)\r
+\r
+----------------------------------// PUBLIC INTERFACE //--\r
+\r
+return {\r
+\r
+    addclient = addclient,\r
+    wrapclient = wrapclient,\r
+    \r
+    loop = loop,\r
+    stats = stats,\r
+    closeall = closeall,\r
+    addtimer = addtimer,\r
+    addserver = addserver,\r
+    getserver = getserver,\r
+    getsettings = getsettings,\r
+    setquitting = setquitting,\r
+    removeserver = removeserver,\r
+    changesettings = changesettings,\r
+}\r