net/server_event.lua

   1 --[[
   2
   3
   4                         server.lua based on lua/libevent by blastbeat
   5
   6                         notes:
   7                         -- when using luaevent, never register 2 or more EV_READ at one socket, same for EV_WRITE
   8                         -- you cant even register a new EV_READ/EV_WRITE callback inside another one
   9                         -- never call eventcallback:close( ) from inside eventcallback
  10                         -- to do some of the above, use timeout events or something what will called from outside
  11                         -- dont let garbagecollect eventcallbacks, as long they are running
  12                         -- when using luasec, there are 4 cases of timeout errors: wantread or wantwrite during reading or writing
  13
  14 --]]
  15
  16 local SCRIPT_NAME           = "server_event.lua"
  17 local SCRIPT_VERSION        = "0.05"
  18 local SCRIPT_AUTHOR         = "blastbeat"
  19 local LAST_MODIFIED         = "2009/11/20"
  20
  21 local cfg = {
  22         MAX_CONNECTIONS       = 100000,  -- max per server connections (use "ulimit -n" on *nix)
  23         MAX_HANDSHAKE_ATTEMPS = 1000,  -- attemps to finish ssl handshake
  24         HANDSHAKE_TIMEOUT     = 30,  -- timout in seconds per handshake attemp
  25         MAX_READ_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes allowed to read from sockets
  26         MAX_SEND_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes size of write buffer (for writing on sockets)
  27         ACCEPT_DELAY          = 10,  -- seconds to wait until the next attemp of a full server to accept
  28         READ_TIMEOUT          = 60 * 30,  -- timeout in seconds for read data from socket
  29         WRITE_TIMEOUT         = 30,  -- timeout in seconds for write data on socket
  30         CONNECT_TIMEOUT       = 20,  -- timeout in seconds for connection attemps
  31         CLEAR_DELAY           = 5,  -- seconds to wait for clearing interface list (and calling ondisconnect listeners)
  32         DEBUG                 = true,  -- show debug messages
  33 }
  34
  35 local function use(x) return rawget(_G, x); end
  36 local print = use "print"
  37 local pcall = use "pcall"
  38 local ipairs = use "ipairs"
  39 local string = use "string"
  40 local select = use "select"
  41 local require = use "require"
  42 local tostring = use "tostring"
  43 local coroutine = use "coroutine"
  44 local setmetatable = use "setmetatable"
  45
  46 local ssl = use "ssl"
  47 local socket = use "socket" or require "socket"
  48
  49 local log = require ("util.logger").init("socket")
  50
  51 local function debug(...)
  52         return log("debug", ("%s "):rep(select('#', ...)), ...)
  53 end
  54 local vdebug = debug;
  55
  56 local bitor = ( function( ) -- thx Rici Lake
  57         local hasbit = function( x, p )
  58                 return x % ( p + p ) >= p
  59         end
  60         return function( x, y )
  61                 local p = 1
  62                 local z = 0
  63                 local limit = x > y and x or y
  64                 while p <= limit do
  65                         if hasbit( x, p ) or hasbit( y, p ) then
  66                                 z = z + p
  67                         end
  68                         p = p + p
  69                 end
  70                 return z
  71         end
  72 end )( )
  73
  74 local event = require "luaevent.core"
  75 local base = event.new( )
  76 local EV_READ = event.EV_READ
  77 local EV_WRITE = event.EV_WRITE
  78 local EV_TIMEOUT = event.EV_TIMEOUT
  79 local EV_SIGNAL = event.EV_SIGNAL
  80
  81 local EV_READWRITE = bitor( EV_READ, EV_WRITE )
  82
  83 local interfacelist = ( function( )  -- holds the interfaces for sockets
  84         local array = { }
  85         local len = 0
  86         return function( method, arg )
  87                 if "add" == method then
  88                         len = len + 1
  89                         array[ len ] = arg
  90                         arg:_position( len )
  91                         return len
  92                 elseif "delete" == method then
  93                         if len <= 0 then
  94                                 return nil, "array is already empty"
  95                         end
  96                         local position = arg:_position()  -- get position in array
  97                         if position ~= len then
  98                                 local interface = array[ len ]  -- get last interface
  99                                 array[ position ] = interface  -- copy it into free position
 100                                 array[ len ] = nil  -- free last position
 101                                 interface:_position( position )  -- set new position in array
 102                         else  -- free last position
 103                                 array[ len ] = nil
 104                         end
 105                         len = len - 1
 106                         return len
 107                 else
 108                         return array
 109                 end
 110         end
 111 end )( )
 112
 113 -- Client interface methods
 114 local interface_mt
 115 do
 116         interface_mt = {}; interface_mt.__index = interface_mt;
 117
 118         local addevent = base.addevent
 119         local coroutine_wrap, coroutine_yield = coroutine.wrap,coroutine.yield
 120         local string_len = string.len
 121
 122         -- Private methods
 123         function interface_mt:_position(new_position)
 124                         self.position = new_position or self.position
 125                         return self.position;
 126         end
 127         function interface_mt:_close() -- regs event to start self:_destroy()
 128                         local callback = function( )
 129                                 self:_destroy();
 130                                 self.eventclose = nil
 131                                 return -1
 132                         end
 133                         self.eventclose = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 134                         return true
 135         end
 136
 137         function interface_mt:_start_connection(plainssl) -- should be called from addclient
 138                         local callback = function( event )
 139                                 if EV_TIMEOUT == event then  -- timout during connection
 140                                         self.fatalerror = "connection timeout"
 141                                         self:ontimeout()  -- call timeout listener
 142                                         self:_close()
 143                                         debug( "new connection failed. id:", self.id, "error:", self.fatalerror )
 144                                 else
 145                                         if plainssl and ssl then  -- start ssl session
 146                                                 self:starttls()
 147                                         else  -- normal connection
 148                                                 self:_start_session( self.listener.onconnect )
 149                                         end
 150                                         debug( "new connection established. id:", self.id )
 151                                 end
 152                                 self.eventconnect = nil
 153                                 return -1
 154                         end
 155                         self.eventconnect = addevent( base, self.conn, EV_WRITE, callback, cfg.CONNECT_TIMEOUT )
 156                         return true
 157         end
 158         function interface_mt:_start_session(onconnect) -- new session, for example after startssl
 159                 if self.type == "client" then
 160                         local callback = function( )
 161                                 self:_lock( false,  false, false )
 162                                 --vdebug( "start listening on client socket with id:", self.id )
 163                                 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT )  -- register callback
 164                                 self:onincoming()
 165                                 self.eventsession = nil
 166                                 return -1
 167                         end
 168                         self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 169                 else
 170                         self:_lock( false )
 171                         --vdebug( "start listening on server socket with id:", self.id )
 172                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback )  -- register callback
 173                 end
 174                 return true
 175         end
 176         function interface_mt:_start_ssl(arg) -- old socket will be destroyed, therefore we have to close read/write events first
 177                         --vdebug( "starting ssl session with client id:", self.id )
 178                         local _
 179                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 180                         _ = self.eventwrite and self.eventwrite:close( )
 181                         self.eventread, self.eventwrite = nil, nil
 182                         local err
 183                         self.conn, err = ssl.wrap( self.conn, self._sslctx )
 184                         if err then
 185                                 self.fatalerror = err
 186                                 self.conn = nil  -- cannot be used anymore
 187                                 if "onconnect" == arg then
 188                                         self.ondisconnect = nil  -- dont call this when client isnt really connected
 189                                 end
 190                                 self:_close()
 191                                 debug( "fatal error while ssl wrapping:", err )
 192                                 return false
 193                         end
 194                         self.conn:settimeout( 0 )  -- set non blocking
 195                         local handshakecallback = coroutine_wrap(
 196                                 function( event )
 197                                         local _, err
 198                                         local attempt = 0
 199                                         local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPS
 200                                         while attempt < maxattempt do  -- no endless loop
 201                                                 attempt = attempt + 1
 202                                                 debug( "ssl handshake of client with id:"..tostring(self).."attemp:"..attempt )
 203                                                 if attempt > maxattempt then
 204                                                         self.fatalerror = "max handshake attemps exceeded"
 205                                                 elseif EV_TIMEOUT == event then
 206                                                         self.fatalerror = "timeout during handshake"
 207                                                 else
 208                                                         _, err = self.conn:dohandshake( )
 209                                                         if not err then
 210                                                                 self:_lock( false, false, false )  -- unlock the interface; sending, closing etc allowed
 211                                                                 self.send = self.conn.send  -- caching table lookups with new client object
 212                                                                 self.receive = self.conn.receive
 213                                                                 local onsomething
 214                                                                 if "onconnect" == arg then  -- trigger listener
 215                                                                         onsomething = self.onconnect
 216                                                                 else
 217                                                                         onsomething = self.onsslconnection
 218                                                                 end
 219                                                                 self:_start_session( onsomething )
 220                                                                 debug( "ssl handshake done" )
 221                                                                 self:onstatus("ssl-handshake-complete");
 222                                                                 self.eventhandshake = nil
 223                                                                 return -1
 224                                                         end
 225                                                         debug( "error during ssl handshake:", err )
 226                                                         if err == "wantwrite" then
 227                                                                 event = EV_WRITE
 228                                                         elseif err == "wantread" then
 229                                                                 event = EV_READ
 230                                                         else
 231                                                                 self.fatalerror = err
 232                                                         end
 233                                                 end
 234                                                 if self.fatalerror then
 235                                                         if "onconnect" == arg then
 236                                                                 self.ondisconnect = nil  -- dont call this when client isnt really connected
 237                                                         end
 238                                                         self:_close()
 239                                                         debug( "handshake failed because:", self.fatalerror )
 240                                                         self.eventhandshake = nil
 241                                                         return -1
 242                                                 end
 243                                                 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT )  -- yield this monster...
 244                                         end
 245                                 end
 246                         )
 247                         debug "starting handshake..."
 248                         self:_lock( false, true, true )  -- unlock read/write events, but keep interface locked
 249                         self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
 250                         return true
 251         end
 252         function interface_mt:_destroy()  -- close this interface + events and call last listener
 253                         debug( "closing client with id:", self.id )
 254                         self:_lock( true, true, true )  -- first of all, lock the interface to avoid further actions
 255                         local _
 256                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 257                         if self.type == "client" then
 258                                 _ = self.eventwrite and self.eventwrite:close( )
 259                                 _ = self.eventhandshake and self.eventhandshake:close( )
 260                                 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
 261                                 _ = self.eventconnect and self.eventconnect:close( )
 262                                 _ = self.eventsession and self.eventsession:close( )
 263                                 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
 264                                 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
 265                                 _ = self.ondisconnect and self:ondisconnect( self.fatalerror ~= "client to close" and self.fatalerror)  -- call ondisconnect listener (wont be the case if handshake failed on connect)
 266                                 _ = self.conn and self.conn:close( ) -- close connection, must also be called outside of any socket registered events!
 267                                 _ = self._server and self._server:counter(-1);
 268                                 self.eventread, self.eventwrite = nil, nil
 269                                 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
 270                                 self.readcallback, self.writecallback = nil, nil
 271                         else
 272                                 self.conn:close( )
 273                                 self.eventread, self.eventclose = nil, nil
 274                                 self.interface, self.readcallback = nil, nil
 275                         end
 276                         interfacelist( "delete", self )
 277                         return true
 278         end
 279
 280         function interface_mt:_lock(nointerface, noreading, nowriting)  -- lock or unlock this interface or events
 281                         self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
 282                         return nointerface, noreading, nowriting
 283         end
 284
 285         function interface_mt:lock_read(switch)
 286                 return self:_lock(self.nointerface, switch, self.nowriting);
 287         end
 288
 289         function interface_mt:counter(c)
 290                 if c then
 291                         self._connections = self._connections + c
 292                 end
 293                 return self._connections
 294         end
 295
 296         -- Public methods
 297         function interface_mt:write(data)
 298                 if self.nowriting then return nil, "locked" end
 299                 --vdebug( "try to send data to client, id/data:", self.id, data )
 300                 data = tostring( data )
 301                 local len = string_len( data )
 302                 local total = len + self.writebufferlen
 303                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
 304                         local err = "send buffer exceeded"
 305                         debug( "error:", err )  -- to much, check your app
 306                         return nil, err
 307                 end
 308                 self.writebuffer = self.writebuffer .. data -- new buffer
 309                 self.writebufferlen = total
 310                 if not self.eventwrite then  -- register new write event
 311                         --vdebug( "register new write event" )
 312                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
 313                 end
 314                 return true
 315         end
 316         function interface_mt:close(now)
 317                 if self.nointerface then return nil, "locked"; end
 318                 debug( "try to close client connection with id:", self.id )
 319                 if self.type == "client" then
 320                         self.fatalerror = "client to close"
 321                         if ( not self.eventwrite ) or now then  -- try to close immediately
 322                                 self:_lock( true, true, true )
 323                                 self:_close()
 324                                 return true
 325                         else  -- wait for incomplete write request
 326                                 self:_lock( true, true, false )
 327                                 debug "closing delayed until writebuffer is empty"
 328                                 return nil, "writebuffer not empty, waiting"
 329                         end
 330                 else
 331                         debug( "try to close server with id:", self.id, "args:", now )
 332                         self.fatalerror = "server to close"
 333                         self:_lock( true )
 334                         local count = 0
 335                         for _, item in ipairs( interfacelist( ) ) do
 336                                 if ( item.type ~= "server" ) and ( item._server == self ) then  -- client/server match
 337                                         if item:close( now ) then  -- writebuffer was empty
 338                                                 count = count + 1
 339                                         end
 340                                 end
 341                         end
 342                         local timeout = 0  -- dont wait for unfinished writebuffers of clients...
 343                         if not now then
 344                                 timeout = cfg.WRITE_TIMEOUT  -- ...or wait for it
 345                         end
 346                         self:_close( timeout )  -- add new event to remove the server interface
 347                         debug( "seconds remained until server is closed:", timeout )
 348                         return count  -- returns finished clients with empty writebuffer
 349                 end
 350         end
 351
 352         function interface_mt:server()
 353                 return self._server or self;
 354         end
 355
 356         function interface_mt:port()
 357                 return self._port
 358         end
 359
 360         function interface_mt:serverport()
 361                 return self._serverport
 362         end
 363
 364         function interface_mt:ip()
 365                 return self._ip
 366         end
 367
 368         function interface_mt:ssl()
 369                 return self._usingssl
 370         end
 371
 372         function interface_mt:type()
 373                 return self._type or "client"
 374         end
 375
 376         function interface_mt:connections()
 377                 return self._connections
 378         end
 379
 380         function interface_mt:address()
 381                 return self.addr
 382         end
 383
 384         function interface_mt:set_sslctx(sslctx)
 385                 self._sslctx = sslctx;
 386                 if sslctx then
 387                         self.starttls = nil; -- use starttls() of interface_mt
 388                 else
 389                         self.starttls = false; -- prevent starttls()
 390                 end
 391         end
 392
 393         function interface_mt:set_send(new_send)
 394                 -- No-op, we always use the underlying connection's send
 395         end
 396
 397         function interface_mt:starttls(sslctx)
 398                 debug( "try to start ssl at client id:", self.id )
 399                 local err
 400                 self._sslctx = sslctx;
 401                 if self._usingssl then  -- startssl was already called
 402                         err = "ssl already active"
 403                 end
 404                 if err then
 405                         debug( "error:", err )
 406                         return nil, err
 407                 end
 408                 self._usingssl = true
 409                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
 410                         self.startsslcallback = nil
 411                         self:_start_ssl();
 412                         self.eventstarthandshake = nil
 413                         return -1
 414                 end
 415                 if not self.eventwrite then
 416                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
 417                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
 418                 else  -- wait until writebuffer is empty
 419                         self:_lock( true, true, false )
 420                         debug "ssl session delayed until writebuffer is empty..."
 421                 end
 422                 self.starttls = false;
 423                 return true
 424         end
 425
 426         function interface_mt:setoption(option, value)
 427                 if self.conn.setoption then
 428                         return self.conn:setoption(option, value);
 429                 end
 430                 return false, "setoption not implemented";
 431         end
 432
 433         function interface_mt:setlistener(listener)
 434                 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout, self.onstatus
 435                         = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout, listener.onstatus;
 436         end
 437
 438         -- Stub handlers
 439         function interface_mt:onconnect()
 440         end
 441         function interface_mt:onincoming()
 442         end
 443         function interface_mt:ondisconnect()
 444         end
 445         function interface_mt:ontimeout()
 446         end
 447         function interface_mt:onstatus()
 448                 debug("server.lua: Dummy onstatus()")
 449         end
 450 end
 451
 452 -- End of client interface methods
 453
 454 local handleclient;
 455 do
 456         local string_sub = string.sub  -- caching table lookups
 457         local string_len = string.len
 458         local addevent = base.addevent
 459         local coroutine_wrap = coroutine.wrap
 460         local socket_gettime = socket.gettime
 461         local coroutine_yield = coroutine.yield
 462         function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 463                 --vdebug("creating client interfacce...")
 464                 local interface = {
 465                         type = "client";
 466                         conn = client;
 467                         currenttime = socket_gettime( );  -- safe the origin
 468                         writebuffer = "";  -- writebuffer
 469                         writebufferlen = 0;  -- length of writebuffer
 470                         send = client.send;  -- caching table lookups
 471                         receive = client.receive;
 472                         onconnect = listener.onconnect;  -- will be called when client disconnects
 473                         ondisconnect = listener.ondisconnect;  -- will be called when client disconnects
 474                         onincoming = listener.onincoming;  -- will be called when client sends data
 475                         ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
 476                         onstatus = listener.onstatus; -- called for status changes (e.g. of SSL/TLS)
 477                         eventread = false, eventwrite = false, eventclose = false,
 478                         eventhandshake = false, eventstarthandshake = false;  -- event handler
 479                         eventconnect = false, eventsession = false;  -- more event handler...
 480                         eventwritetimeout = false;  -- even more event handler...
 481                         eventreadtimeout = false;
 482                         fatalerror = false;  -- error message
 483                         writecallback = false;  -- will be called on write events
 484                         readcallback = false;  -- will be called on read events
 485                         nointerface = true;  -- lock/unlock parameter of this interface
 486                         noreading = false, nowriting = false;  -- locks of the read/writecallback
 487                         startsslcallback = false;  -- starting handshake callback
 488                         position = false;  -- position of client in interfacelist
 489
 490                         -- Properties
 491                         _ip = ip, _port = port, _server = server, _pattern = pattern,
 492                         _serverport = (server and server:port() or nil),
 493                         _sslctx = sslctx; -- parameters
 494                         _usingssl = false;  -- client is using ssl;
 495                 }
 496                 if not ssl then interface.starttls = false; end
 497                 interface.id = tostring(interface):match("%x+$");
 498                 interface.writecallback = function( event )  -- called on write events
 499                         --vdebug( "new client write event, id/ip/port:", interface, ip, port )
 500                         if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then  -- leave this event
 501                                 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
 502                                 interface.eventwrite = false
 503                                 return -1
 504                         end
 505                         if EV_TIMEOUT == event then  -- took too long to write some data to socket -> disconnect
 506                                 interface.fatalerror = "timeout during writing"
 507                                 debug( "writing failed:", interface.fatalerror )
 508                                 interface:_close()
 509                                 interface.eventwrite = false
 510                                 return -1
 511                         else  -- can write :)
 512                                 if interface._usingssl then  -- handle luasec
 513                                         if interface.eventreadtimeout then  -- we have to read first
 514                                                 local ret = interface.readcallback( )  -- call readcallback
 515                                                 --vdebug( "tried to read in writecallback, result:", ret )
 516                                         end
 517                                         if interface.eventwritetimeout then  -- luasec only
 518                                                 interface.eventwritetimeout:close( )  -- first we have to close timeout event which where regged after a wantread error
 519                                                 interface.eventwritetimeout = false
 520                                         end
 521                                 end
 522                                 local succ, err, byte = interface.conn:send( interface.writebuffer, 1, interface.writebufferlen )
 523                                 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
 524                                 if succ then  -- writing succesful
 525                                         interface.writebuffer = ""
 526                                         interface.writebufferlen = 0
 527                                         if interface.fatalerror then
 528                                                 debug "closing client after writing"
 529                                                 interface:_close()  -- close interface if needed
 530                                         elseif interface.startsslcallback then  -- start ssl connection if needed
 531                                                 debug "starting ssl handshake after writing"
 532                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
 533                                         elseif interface.eventreadtimeout then
 534                                                 return EV_WRITE, EV_TIMEOUT
 535                                         end
 536                                         interface.eventwrite = nil
 537                                         return -1
 538                                 elseif byte then  -- want write again
 539                                         --vdebug( "writebuffer is not empty:", err )
 540                                         interface.writebuffer = string_sub( interface.writebuffer, byte + 1, interface.writebufferlen )  -- new buffer
 541                                         interface.writebufferlen = interface.writebufferlen - byte
 542                                         if "wantread" == err then  -- happens only with luasec
 543                                                 local callback = function( )
 544                                                         interface:_close()
 545                                                         interface.eventwritetimeout = nil
 546                                                         return evreturn, evtimeout
 547                                                 end
 548                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
 549                                                 debug( "wantread during write attemp, reg it in readcallback but dont know what really happens next..." )
 550                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
 551                                                 return -1
 552                                         end
 553                                         return EV_WRITE, cfg.WRITE_TIMEOUT
 554                                 else  -- connection was closed during writing or fatal error
 555                                         interface.fatalerror = err or "fatal error"
 556                                         debug( "connection failed in write event:", interface.fatalerror )
 557                                         interface:_close()
 558                                         interface.eventwrite = nil
 559                                         return -1
 560                                 end
 561                         end
 562                 end
 563
 564                 interface.readcallback = function( event )  -- called on read events
 565                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
 566                         if interface.noreading or interface.fatalerror then  -- leave this event
 567                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
 568                                 interface.eventread = nil
 569                                 return -1
 570                         end
 571                         if EV_TIMEOUT == event then  -- took too long to get some data from client -> disconnect
 572                                 interface.fatalerror = "timeout during receiving"
 573                                 debug( "connection failed:", interface.fatalerror )
 574                                 interface:_close()
 575                                 interface.eventread = nil
 576                                 return -1
 577                         else -- can read
 578                                 if interface._usingssl then  -- handle luasec
 579                                         if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
 580                                                 local ret = interface.writecallback( )  -- call it
 581                                                 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
 582                                         end
 583                                         if interface.eventreadtimeout then
 584                                                 interface.eventreadtimeout:close( )
 585                                                 interface.eventreadtimeout = nil
 586                                         end
 587                                 end
 588                                 local buffer, err, part = interface.conn:receive( pattern )  -- receive buffer with "pattern"
 589                                 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
 590                                 buffer = buffer or part or ""
 591                                 local len = string_len( buffer )
 592                                 if len > cfg.MAX_READ_LENGTH then  -- check buffer length
 593                                         interface.fatalerror = "receive buffer exceeded"
 594                                         debug( "fatal error:", interface.fatalerror )
 595                                         interface:_close()
 596                                         interface.eventread = nil
 597                                         return -1
 598                                 end
 599                                 interface.onincoming( interface, buffer, err )  -- send new data to listener
 600                                 if err and ( err ~= "timeout" and err ~= "wantread" ) then
 601                                         if "wantwrite" == err then -- need to read on write event
 602                                                 if not interface.eventwrite then  -- register new write event if needed
 603                                                         interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
 604                                                 end
 605                                                 interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
 606                                                         function( )
 607                                                                 interface:_close()
 608                                                         end, cfg.READ_TIMEOUT
 609                                                 )
 610                                                 debug( "wantwrite during read attemp, reg it in writecallback but dont know what really happens next..." )
 611                                                 -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
 612                                         else  -- connection was closed or fatal error
 613                                                 interface.fatalerror = err
 614                                                 debug( "connection failed in read event:", interface.fatalerror )
 615                                                 interface:_close()
 616                                                 interface.eventread = nil
 617                                                 return -1
 618                                         end
 619                                 end
 620                                 return EV_READ, cfg.READ_TIMEOUT
 621                         end
 622                 end
 623
 624                 client:settimeout( 0 )  -- set non blocking
 625                 setmetatable(interface, interface_mt)
 626                 interfacelist( "add", interface )  -- add to interfacelist
 627                 return interface
 628         end
 629 end
 630
 631 local handleserver
 632 do
 633         function handleserver( server, addr, port, pattern, listener, sslctx )  -- creates an server interface
 634                 debug "creating server interface..."
 635                 local interface = {
 636                         _connections = 0;
 637
 638                         conn = server;
 639                         onconnect = listener.onconnect;  -- will be called when new client connected
 640                         eventread = false;  -- read event handler
 641                         eventclose = false; -- close event handler
 642                         readcallback = false; -- read event callback
 643                         fatalerror = false; -- error message
 644                         nointerface = true;  -- lock/unlock parameter
 645
 646                         _ip = addr, _port = port, _pattern = pattern,
 647                         _sslctx = sslctx;
 648                 }
 649                 interface.id = tostring(interface):match("%x+$");
 650                 interface.readcallback = function( event )  -- server handler, called on incoming connections
 651                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
 652                         if interface.fatalerror then
 653                                 --vdebug( "leaving this event because:", self.fatalerror )
 654                                 interface.eventread = nil
 655                                 return -1
 656                         end
 657                         local delay = cfg.ACCEPT_DELAY
 658                         if EV_TIMEOUT == event then
 659                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
 660                                         debug( "to many connections, seconds to wait for next accept:", delay )
 661                                         return EV_TIMEOUT, delay  -- timeout...
 662                                 else
 663                                         return EV_READ  -- accept again
 664                                 end
 665                         end
 666                         --vdebug("max connection check ok, accepting...")
 667                         local client, err = server:accept()    -- try to accept; TODO: check err
 668                         while client do
 669                                 if interface._connections >= cfg.MAX_CONNECTIONS then
 670                                         client:close( )  -- refuse connection
 671                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
 672                                         return EV_TIMEOUT, delay  -- delay for next accept attemp
 673                                 end
 674                                 local client_ip, client_port = client:getpeername( )
 675                                 interface._connections = interface._connections + 1  -- increase connection count
 676                                 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, nil, sslctx )
 677                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
 678                                 if ssl and sslctx then
 679                                         clientinterface:starttls(sslctx)
 680                                 else
 681                                         clientinterface:_start_session( clientinterface.onconnect )
 682                                 end
 683                                 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
 684
 685                                 client, err = server:accept()    -- try to accept again
 686                         end
 687                         return EV_READ
 688                 end
 689
 690                 server:settimeout( 0 )
 691                 setmetatable(interface, interface_mt)
 692                 interfacelist( "add", interface )
 693                 interface:_start_session()
 694                 return interface
 695         end
 696 end
 697
 698 local addserver = ( function( )
 699         return function( addr, port, listener, pattern, sslcfg, startssl )  -- TODO: check arguments
 700                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
 701                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
 702                 if not server then
 703                         debug( "creating server socket failed because:", err )
 704                         return nil, err
 705                 end
 706                 local sslctx
 707                 if sslcfg then
 708                         if not ssl then
 709                                 debug "fatal error: luasec not found"
 710                                 return nil, "luasec not found"
 711                         end
 712                         sslctx, err = sslcfg
 713                         if err then
 714                                 debug( "error while creating new ssl context for server socket:", err )
 715                                 return nil, err
 716                         end
 717                 end
 718                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
 719                 debug( "new server created with id:", tostring(interface))
 720                 return interface
 721         end
 722 end )( )
 723
 724 local addclient, wrapclient
 725 do
 726         function wrapclient( client, ip, port, listeners, pattern, sslctx, startssl )
 727                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
 728                 interface:_start_session()
 729                 return interface
 730                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 731         end
 732
 733         function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
 734                 local client, err = socket.tcp()  -- creating new socket
 735                 if not client then
 736                         debug( "cannot create socket:", err )
 737                         return nil, err
 738                 end
 739                 client:settimeout( 0 )  -- set nonblocking
 740                 if localaddr then
 741                         local res, err = client:bind( localaddr, localport, -1 )
 742                         if not res then
 743                                 debug( "cannot bind client:", err )
 744                                 return nil, err
 745                         end
 746                 end
 747                 local sslctx
 748                 if sslcfg then  -- handle ssl/new context
 749                         if not ssl then
 750                                 debug "need luasec, but not available"
 751                                 return nil, "luasec not found"
 752                         end
 753                         sslctx, err = sslcfg
 754                         if err then
 755                                 debug( "cannot create new ssl context:", err )
 756                                 return nil, err
 757                         end
 758                 end
 759                 local res, err = client:connect( addr, serverport )  -- connect
 760                 if res or ( err == "timeout" ) then
 761                         local ip, port = client:getsockname( )
 762                         local server = function( )
 763                                 return nil, "this is a dummy server interface"
 764                         end
 765                         local interface = wrapclient( client, ip, serverport, listeners, pattern, sslctx, startssl )
 766                         interface:_start_connection( startssl )
 767                         debug( "new connection id:", interface.id )
 768                         return interface, err
 769                 else
 770                         debug( "new connection failed:", err )
 771                         return nil, err
 772                 end
 773         end
 774 end
 775
 776
 777 local loop = function( )  -- starts the event loop
 778         base:loop( )
 779         return "quitting";
 780 end
 781
 782 local newevent = ( function( )
 783         local add = base.addevent
 784         return function( ... )
 785                 return add( base, ... )
 786         end
 787 end )( )
 788
 789 local closeallservers = function( arg )
 790         for _, item in ipairs( interfacelist( ) ) do
 791                 if item.type == "server" then
 792                         item:close( arg )
 793                 end
 794         end
 795 end
 796
 797 local function setquitting(yes)
 798         if yes then
 799                  -- Quit now
 800                  closeallservers();
 801                  base:loopexit();
 802         end
 803 end
 804
 805 function get_backend()
 806         return base:method();
 807 end
 808
 809 -- We need to hold onto the events to stop them
 810 -- being garbage-collected
 811 local signal_events = {}; -- [signal_num] -> event object
 812 function hook_signal(signal_num, handler)
 813         local function _handler(event)
 814                 local ret = handler();
 815                 if ret ~= false then -- Continue handling this signal?
 816                         return EV_SIGNAL; -- Yes
 817                 end
 818                 return -1; -- Close this event
 819         end
 820         signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
 821         return signal_events[signal_num];
 822 end
 823
 824 return {
 825
 826         cfg = cfg,
 827         base = base,
 828         loop = loop,
 829         event = event,
 830         event_base = base,
 831         addevent = newevent,
 832         addserver = addserver,
 833         addclient = addclient,
 834         wrapclient = wrapclient,
 835         setquitting = setquitting,
 836         closeall = closeallservers,
 837         get_backend = get_backend,
 838         hook_signal = hook_signal,
 839
 840         __NAME = SCRIPT_NAME,
 841         __DATE = LAST_MODIFIED,
 842         __AUTHOR = SCRIPT_AUTHOR,
 843         __VERSION = SCRIPT_VERSION,
 844
 845 }