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                         -- to do some of the above, use timeout events or something what will called from outside
  10                         -- dont let garbagecollect eventcallbacks, as long they are running
  11                         -- when using luasec, there are 4 cases of timeout errors: wantread or wantwrite during reading or writing
  12
  13 --]]
  14
  15 local SCRIPT_NAME           = "server_event.lua"
  16 local SCRIPT_VERSION        = "0.05"
  17 local SCRIPT_AUTHOR         = "blastbeat"
  18 local LAST_MODIFIED         = "2009/11/20"
  19
  20 local cfg = {
  21         MAX_CONNECTIONS       = 100000,  -- max per server connections (use "ulimit -n" on *nix)
  22         MAX_HANDSHAKE_ATTEMPTS= 1000,  -- attempts to finish ssl handshake
  23         HANDSHAKE_TIMEOUT     = 60,  -- timeout in seconds per handshake attempt
  24         MAX_READ_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes allowed to read from sockets
  25         MAX_SEND_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes size of write buffer (for writing on sockets)
  26         ACCEPT_DELAY          = 10,  -- seconds to wait until the next attempt of a full server to accept
  27         READ_TIMEOUT          = 60 * 60 * 6,  -- timeout in seconds for read data from socket
  28         WRITE_TIMEOUT         = 180,  -- timeout in seconds for write data on socket
  29         CONNECT_TIMEOUT       = 20,  -- timeout in seconds for connection attempts
  30         CLEAR_DELAY           = 5,  -- seconds to wait for clearing interface list (and calling ondisconnect listeners)
  31         DEBUG                 = true,  -- show debug messages
  32 }
  33
  34 local function use(x) return rawget(_G, x); end
  35 local ipairs = use "ipairs"
  36 local string = use "string"
  37 local select = use "select"
  38 local require = use "require"
  39 local tostring = use "tostring"
  40 local coroutine = use "coroutine"
  41 local setmetatable = use "setmetatable"
  42
  43 local ssl = use "ssl"
  44 local socket = use "socket" or require "socket"
  45
  46 local log = require ("util.logger").init("socket")
  47
  48 local function debug(...)
  49         return log("debug", ("%s "):rep(select('#', ...)), ...)
  50 end
  51 local vdebug = debug;
  52
  53 local bitor = ( function( ) -- thx Rici Lake
  54         local hasbit = function( x, p )
  55                 return x % ( p + p ) >= p
  56         end
  57         return function( x, y )
  58                 local p = 1
  59                 local z = 0
  60                 local limit = x > y and x or y
  61                 while p <= limit do
  62                         if hasbit( x, p ) or hasbit( y, p ) then
  63                                 z = z + p
  64                         end
  65                         p = p + p
  66                 end
  67                 return z
  68         end
  69 end )( )
  70
  71 local event = require "luaevent.core"
  72 local base = event.new( )
  73 local EV_READ = event.EV_READ
  74 local EV_WRITE = event.EV_WRITE
  75 local EV_TIMEOUT = event.EV_TIMEOUT
  76 local EV_SIGNAL = event.EV_SIGNAL
  77
  78 local EV_READWRITE = bitor( EV_READ, EV_WRITE )
  79
  80 local interfacelist = ( function( )  -- holds the interfaces for sockets
  81         local array = { }
  82         local len = 0
  83         return function( method, arg )
  84                 if "add" == method then
  85                         len = len + 1
  86                         array[ len ] = arg
  87                         arg:_position( len )
  88                         return len
  89                 elseif "delete" == method then
  90                         if len <= 0 then
  91                                 return nil, "array is already empty"
  92                         end
  93                         local position = arg:_position()  -- get position in array
  94                         if position ~= len then
  95                                 local interface = array[ len ]  -- get last interface
  96                                 array[ position ] = interface  -- copy it into free position
  97                                 array[ len ] = nil  -- free last position
  98                                 interface:_position( position )  -- set new position in array
  99                         else  -- free last position
 100                                 array[ len ] = nil
 101                         end
 102                         len = len - 1
 103                         return len
 104                 else
 105                         return array
 106                 end
 107         end
 108 end )( )
 109
 110 -- Client interface methods
 111 local interface_mt
 112 do
 113         interface_mt = {}; interface_mt.__index = interface_mt;
 114
 115         local addevent = base.addevent
 116         local coroutine_wrap, coroutine_yield = coroutine.wrap,coroutine.yield
 117
 118         -- Private methods
 119         function interface_mt:_position(new_position)
 120                         self.position = new_position or self.position
 121                         return self.position;
 122         end
 123         function interface_mt:_close()
 124                 return self:_destroy();
 125         end
 126
 127         function interface_mt:_start_connection(plainssl) -- should be called from addclient
 128                         local callback = function( event )
 129                                 if EV_TIMEOUT == event then  -- timeout during connection
 130                                         self.fatalerror = "connection timeout"
 131                                         self:ontimeout()  -- call timeout listener
 132                                         self:_close()
 133                                         debug( "new connection failed. id:", self.id, "error:", self.fatalerror )
 134                                 else
 135                                         if plainssl and ssl then  -- start ssl session
 136                                                 self:starttls(self._sslctx, true)
 137                                         else  -- normal connection
 138                                                 self:_start_session(true)
 139                                         end
 140                                         debug( "new connection established. id:", self.id )
 141                                 end
 142                                 self.eventconnect = nil
 143                                 return -1
 144                         end
 145                         self.eventconnect = addevent( base, self.conn, EV_WRITE, callback, cfg.CONNECT_TIMEOUT )
 146                         return true
 147         end
 148         function interface_mt:_start_session(call_onconnect) -- new session, for example after startssl
 149                 if self.type == "client" then
 150                         local callback = function( )
 151                                 self:_lock( false,  false, false )
 152                                 --vdebug( "start listening on client socket with id:", self.id )
 153                                 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 154                                 if call_onconnect then
 155                                         self:onconnect()
 156                                 end
 157                                 self.eventsession = nil
 158                                 return -1
 159                         end
 160                         self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 161                 else
 162                         self:_lock( false )
 163                         --vdebug( "start listening on server socket with id:", self.id )
 164                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback )  -- register callback
 165                 end
 166                 return true
 167         end
 168         function interface_mt:_start_ssl(call_onconnect) -- old socket will be destroyed, therefore we have to close read/write events first
 169                         --vdebug( "starting ssl session with client id:", self.id )
 170                         local _
 171                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 172                         _ = self.eventwrite and self.eventwrite:close( )
 173                         self.eventread, self.eventwrite = nil, nil
 174                         local err
 175                         self.conn, err = ssl.wrap( self.conn, self._sslctx )
 176                         if err then
 177                                 self.fatalerror = err
 178                                 self.conn = nil  -- cannot be used anymore
 179                                 if call_onconnect then
 180                                         self.ondisconnect = nil  -- dont call this when client isnt really connected
 181                                 end
 182                                 self:_close()
 183                                 debug( "fatal error while ssl wrapping:", err )
 184                                 return false
 185                         end
 186                         self.conn:settimeout( 0 )  -- set non blocking
 187                         local handshakecallback = coroutine_wrap(
 188                                 function( event )
 189                                         local _, err
 190                                         local attempt = 0
 191                                         local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPTS
 192                                         while attempt < maxattempt do  -- no endless loop
 193                                                 attempt = attempt + 1
 194                                                 debug( "ssl handshake of client with id:"..tostring(self)..", attempt:"..attempt )
 195                                                 if attempt > maxattempt then
 196                                                         self.fatalerror = "max handshake attempts exceeded"
 197                                                 elseif EV_TIMEOUT == event then
 198                                                         self.fatalerror = "timeout during handshake"
 199                                                 else
 200                                                         _, err = self.conn:dohandshake( )
 201                                                         if not err then
 202                                                                 self:_lock( false, false, false )  -- unlock the interface; sending, closing etc allowed
 203                                                                 self.send = self.conn.send  -- caching table lookups with new client object
 204                                                                 self.receive = self.conn.receive
 205                                                                 if not call_onconnect then  -- trigger listener
 206                                                                         self:onstatus("ssl-handshake-complete");
 207                                                                 end
 208                                                                 self:_start_session( call_onconnect )
 209                                                                 debug( "ssl handshake done" )
 210                                                                 self.eventhandshake = nil
 211                                                                 return -1
 212                                                         end
 213                                                         if err == "wantwrite" then
 214                                                                 event = EV_WRITE
 215                                                         elseif err == "wantread" then
 216                                                                 event = EV_READ
 217                                                         else
 218                                                                 debug( "ssl handshake error:", err )
 219                                                                 self.fatalerror = err
 220                                                         end
 221                                                 end
 222                                                 if self.fatalerror then
 223                                                         if call_onconnect then
 224                                                                 self.ondisconnect = nil  -- dont call this when client isnt really connected
 225                                                         end
 226                                                         self:_close()
 227                                                         debug( "handshake failed because:", self.fatalerror )
 228                                                         self.eventhandshake = nil
 229                                                         return -1
 230                                                 end
 231                                                 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT )  -- yield this monster...
 232                                         end
 233                                 end
 234                         )
 235                         debug "starting handshake..."
 236                         self:_lock( false, true, true )  -- unlock read/write events, but keep interface locked
 237                         self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
 238                         return true
 239         end
 240         function interface_mt:_destroy()  -- close this interface + events and call last listener
 241                         debug( "closing client with id:", self.id, self.fatalerror )
 242                         self:_lock( true, true, true )  -- first of all, lock the interface to avoid further actions
 243                         local _
 244                         _ = self.eventread and self.eventread:close( )
 245                         if self.type == "client" then
 246                                 _ = self.eventwrite and self.eventwrite:close( )
 247                                 _ = self.eventhandshake and self.eventhandshake:close( )
 248                                 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
 249                                 _ = self.eventconnect and self.eventconnect:close( )
 250                                 _ = self.eventsession and self.eventsession:close( )
 251                                 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
 252                                 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
 253                                 _ = 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)
 254                                 _ = self.conn and self.conn:close( ) -- close connection
 255                                 _ = self._server and self._server:counter(-1);
 256                                 self.eventread, self.eventwrite = nil, nil
 257                                 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
 258                                 self.readcallback, self.writecallback = nil, nil
 259                         else
 260                                 self.conn:close( )
 261                                 self.eventread, self.eventclose = nil, nil
 262                                 self.interface, self.readcallback = nil, nil
 263                         end
 264                         interfacelist( "delete", self )
 265                         return true
 266         end
 267
 268         function interface_mt:_lock(nointerface, noreading, nowriting)  -- lock or unlock this interface or events
 269                         self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
 270                         return nointerface, noreading, nowriting
 271         end
 272
 273         --TODO: Deprecate
 274         function interface_mt:lock_read(switch)
 275                 if switch then
 276                         return self:pause();
 277                 else
 278                         return self:resume();
 279                 end
 280         end
 281
 282         function interface_mt:pause()
 283                 return self:_lock(self.nointerface, true, self.nowriting);
 284         end
 285
 286         function interface_mt:resume()
 287                 self:_lock(self.nointerface, false, self.nowriting);
 288                 if not self.eventread then
 289                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 290                 end
 291         end
 292
 293         function interface_mt:counter(c)
 294                 if c then
 295                         self._connections = self._connections + c
 296                 end
 297                 return self._connections
 298         end
 299
 300         -- Public methods
 301         function interface_mt:write(data)
 302                 if self.nowriting then return nil, "locked" end
 303                 --vdebug( "try to send data to client, id/data:", self.id, data )
 304                 data = tostring( data )
 305                 local len = #data
 306                 local total = len + self.writebufferlen
 307                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
 308                         local err = "send buffer exceeded"
 309                         debug( "error:", err )  -- to much, check your app
 310                         return nil, err
 311                 end
 312                 self.writebuffer = self.writebuffer .. data -- new buffer
 313                 self.writebufferlen = total
 314                 if not self.eventwrite then  -- register new write event
 315                         --vdebug( "register new write event" )
 316                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
 317                 end
 318                 return true
 319         end
 320         function interface_mt:close()
 321                 if self.nointerface then return nil, "locked"; end
 322                 debug( "try to close client connection with id:", self.id )
 323                 if self.type == "client" then
 324                         self.fatalerror = "client to close"
 325                         if self.eventwrite then -- 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                         else -- close now
 330                                 self:_lock( true, true, true )
 331                                 self:_close()
 332                                 return true
 333                         end
 334                 else
 335                         debug( "try to close server with id:", tostring(self.id))
 336                         self.fatalerror = "server to close"
 337                         self:_lock( true )
 338                         self:_close( 0 )
 339                         return true
 340                 end
 341         end
 342
 343         function interface_mt:socket()
 344                 return self.conn
 345         end
 346
 347         function interface_mt:server()
 348                 return self._server or self;
 349         end
 350
 351         function interface_mt:port()
 352                 return self._port
 353         end
 354
 355         function interface_mt:serverport()
 356                 return self._serverport
 357         end
 358
 359         function interface_mt:ip()
 360                 return self._ip
 361         end
 362
 363         function interface_mt:ssl()
 364                 return self._usingssl
 365         end
 366
 367         function interface_mt:type()
 368                 return self._type or "client"
 369         end
 370
 371         function interface_mt:connections()
 372                 return self._connections
 373         end
 374
 375         function interface_mt:address()
 376                 return self.addr
 377         end
 378
 379         function interface_mt:set_sslctx(sslctx)
 380                 self._sslctx = sslctx;
 381                 if sslctx then
 382                         self.starttls = nil; -- use starttls() of interface_mt
 383                 else
 384                         self.starttls = false; -- prevent starttls()
 385                 end
 386         end
 387
 388         function interface_mt:set_mode(pattern)
 389                 if pattern then
 390                         self._pattern = pattern;
 391                 end
 392                 return self._pattern;
 393         end
 394
 395         function interface_mt:set_send(new_send)
 396                 -- No-op, we always use the underlying connection's send
 397         end
 398
 399         function interface_mt:starttls(sslctx, call_onconnect)
 400                 debug( "try to start ssl at client id:", self.id )
 401                 local err
 402                 self._sslctx = sslctx;
 403                 if self._usingssl then  -- startssl was already called
 404                         err = "ssl already active"
 405                 end
 406                 if err then
 407                         debug( "error:", err )
 408                         return nil, err
 409                 end
 410                 self._usingssl = true
 411                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
 412                         self.startsslcallback = nil
 413                         self:_start_ssl(call_onconnect);
 414                         self.eventstarthandshake = nil
 415                         return -1
 416                 end
 417                 if not self.eventwrite then
 418                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
 419                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
 420                 else  -- wait until writebuffer is empty
 421                         self:_lock( true, true, false )
 422                         debug "ssl session delayed until writebuffer is empty..."
 423                 end
 424                 self.starttls = false;
 425                 return true
 426         end
 427
 428         function interface_mt:setoption(option, value)
 429                 if self.conn.setoption then
 430                         return self.conn:setoption(option, value);
 431                 end
 432                 return false, "setoption not implemented";
 433         end
 434
 435         function interface_mt:setlistener(listener)
 436                 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout, self.onstatus
 437                         = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout, listener.onstatus;
 438         end
 439
 440         -- Stub handlers
 441         function interface_mt:onconnect()
 442         end
 443         function interface_mt:onincoming()
 444         end
 445         function interface_mt:ondisconnect()
 446         end
 447         function interface_mt:ontimeout()
 448         end
 449         function interface_mt:ondrain()
 450         end
 451         function interface_mt:onstatus()
 452         end
 453 end
 454
 455 -- End of client interface methods
 456
 457 local handleclient;
 458 do
 459         local string_sub = string.sub  -- caching table lookups
 460         local string_len = string.len
 461         local addevent = base.addevent
 462         local socket_gettime = socket.gettime
 463         function handleclient( client, ip, port, server, pattern, listener, sslctx )  -- creates an client interface
 464                 --vdebug("creating client interfacce...")
 465                 local interface = {
 466                         type = "client";
 467                         conn = client;
 468                         currenttime = socket_gettime( );  -- safe the origin
 469                         writebuffer = "";  -- writebuffer
 470                         writebufferlen = 0;  -- length of writebuffer
 471                         send = client.send;  -- caching table lookups
 472                         receive = client.receive;
 473                         onconnect = listener.onconnect;  -- will be called when client disconnects
 474                         ondisconnect = listener.ondisconnect;  -- will be called when client disconnects
 475                         onincoming = listener.onincoming;  -- will be called when client sends data
 476                         ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
 477                         onstatus = listener.onstatus; -- called for status changes (e.g. of SSL/TLS)
 478                         eventread = false, eventwrite = false, eventclose = false,
 479                         eventhandshake = false, eventstarthandshake = false;  -- event handler
 480                         eventconnect = false, eventsession = false;  -- more event handler...
 481                         eventwritetimeout = false;  -- even more event handler...
 482                         eventreadtimeout = false;
 483                         fatalerror = false;  -- error message
 484                         writecallback = false;  -- will be called on write events
 485                         readcallback = false;  -- will be called on read events
 486                         nointerface = true;  -- lock/unlock parameter of this interface
 487                         noreading = false, nowriting = false;  -- locks of the read/writecallback
 488                         startsslcallback = false;  -- starting handshake callback
 489                         position = false;  -- position of client in interfacelist
 490
 491                         -- Properties
 492                         _ip = ip, _port = port, _server = server, _pattern = pattern,
 493                         _serverport = (server and server:port() or nil),
 494                         _sslctx = sslctx; -- parameters
 495                         _usingssl = false;  -- client is using ssl;
 496                 }
 497                 if not ssl then interface.starttls = false; end
 498                 interface.id = tostring(interface):match("%x+$");
 499                 interface.writecallback = function( event )  -- called on write events
 500                         --vdebug( "new client write event, id/ip/port:", interface, ip, port )
 501                         if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then  -- leave this event
 502                                 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
 503                                 interface.eventwrite = false
 504                                 return -1
 505                         end
 506                         if EV_TIMEOUT == event then  -- took too long to write some data to socket -> disconnect
 507                                 interface.fatalerror = "timeout during writing"
 508                                 debug( "writing failed:", interface.fatalerror )
 509                                 interface:_close()
 510                                 interface.eventwrite = false
 511                                 return -1
 512                         else  -- can write :)
 513                                 if interface._usingssl then  -- handle luasec
 514                                         if interface.eventreadtimeout then  -- we have to read first
 515                                                 local ret = interface.readcallback( )  -- call readcallback
 516                                                 --vdebug( "tried to read in writecallback, result:", ret )
 517                                         end
 518                                         if interface.eventwritetimeout then  -- luasec only
 519                                                 interface.eventwritetimeout:close( )  -- first we have to close timeout event which where regged after a wantread error
 520                                                 interface.eventwritetimeout = false
 521                                         end
 522                                 end
 523                                 local succ, err, byte = interface.conn:send( interface.writebuffer, 1, interface.writebufferlen )
 524                                 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
 525                                 if succ then  -- writing succesful
 526                                         interface.writebuffer = ""
 527                                         interface.writebufferlen = 0
 528                                         interface:ondrain();
 529                                         if interface.fatalerror then
 530                                                 debug "closing client after writing"
 531                                                 interface:_close()  -- close interface if needed
 532                                         elseif interface.startsslcallback then  -- start ssl connection if needed
 533                                                 debug "starting ssl handshake after writing"
 534                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
 535                                         elseif interface.eventreadtimeout then
 536                                                 return EV_WRITE, EV_TIMEOUT
 537                                         end
 538                                         interface.eventwrite = nil
 539                                         return -1
 540                                 elseif byte and (err == "timeout" or err == "wantwrite") then  -- want write again
 541                                         --vdebug( "writebuffer is not empty:", err )
 542                                         interface.writebuffer = string_sub( interface.writebuffer, byte + 1, interface.writebufferlen )  -- new buffer
 543                                         interface.writebufferlen = interface.writebufferlen - byte
 544                                         if "wantread" == err then  -- happens only with luasec
 545                                                 local callback = function( )
 546                                                         interface:_close()
 547                                                         interface.eventwritetimeout = nil
 548                                                         return -1;
 549                                                 end
 550                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
 551                                                 debug( "wantread during write attempt, reg it in readcallback but dont know what really happens next..." )
 552                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
 553                                                 return -1
 554                                         end
 555                                         return EV_WRITE, cfg.WRITE_TIMEOUT
 556                                 else  -- connection was closed during writing or fatal error
 557                                         interface.fatalerror = err or "fatal error"
 558                                         debug( "connection failed in write event:", interface.fatalerror )
 559                                         interface:_close()
 560                                         interface.eventwrite = nil
 561                                         return -1
 562                                 end
 563                         end
 564                 end
 565
 566                 interface.readcallback = function( event )  -- called on read events
 567                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
 568                         if interface.noreading or interface.fatalerror then  -- leave this event
 569                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
 570                                 interface.eventread = nil
 571                                 return -1
 572                         end
 573                         if EV_TIMEOUT == event then  -- took too long to get some data from client -> disconnect
 574                                 interface.fatalerror = "timeout during receiving"
 575                                 debug( "connection failed:", interface.fatalerror )
 576                                 interface:_close()
 577                                 interface.eventread = nil
 578                                 return -1
 579                         else -- can read
 580                                 if interface._usingssl then  -- handle luasec
 581                                         if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
 582                                                 local ret = interface.writecallback( )  -- call it
 583                                                 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
 584                                         end
 585                                         if interface.eventreadtimeout then
 586                                                 interface.eventreadtimeout:close( )
 587                                                 interface.eventreadtimeout = nil
 588                                         end
 589                                 end
 590                                 local buffer, err, part = interface.conn:receive( interface._pattern )  -- receive buffer with "pattern"
 591                                 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
 592                                 buffer = buffer or part
 593                                 if buffer and #buffer > cfg.MAX_READ_LENGTH then  -- check buffer length
 594                                         interface.fatalerror = "receive buffer exceeded"
 595                                         debug( "fatal error:", interface.fatalerror )
 596                                         interface:_close()
 597                                         interface.eventread = nil
 598                                         return -1
 599                                 end
 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 attempt, 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                                 else
 620                                         interface.onincoming( interface, buffer, err )  -- send new data to listener
 621                                 end
 622                                 if interface.noreading then
 623                                         interface.eventread = nil;
 624                                         return -1;
 625                                 end
 626                                 return EV_READ, cfg.READ_TIMEOUT
 627                         end
 628                 end
 629
 630                 client:settimeout( 0 )  -- set non blocking
 631                 setmetatable(interface, interface_mt)
 632                 interfacelist( "add", interface )  -- add to interfacelist
 633                 return interface
 634         end
 635 end
 636
 637 local handleserver
 638 do
 639         function handleserver( server, addr, port, pattern, listener, sslctx )  -- creates an server interface
 640                 debug "creating server interface..."
 641                 local interface = {
 642                         _connections = 0;
 643
 644                         conn = server;
 645                         onconnect = listener.onconnect;  -- will be called when new client connected
 646                         eventread = false;  -- read event handler
 647                         eventclose = false; -- close event handler
 648                         readcallback = false; -- read event callback
 649                         fatalerror = false; -- error message
 650                         nointerface = true;  -- lock/unlock parameter
 651
 652                         _ip = addr, _port = port, _pattern = pattern,
 653                         _sslctx = sslctx;
 654                 }
 655                 interface.id = tostring(interface):match("%x+$");
 656                 interface.readcallback = function( event )  -- server handler, called on incoming connections
 657                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
 658                         if interface.fatalerror then
 659                                 --vdebug( "leaving this event because:", self.fatalerror )
 660                                 interface.eventread = nil
 661                                 return -1
 662                         end
 663                         local delay = cfg.ACCEPT_DELAY
 664                         if EV_TIMEOUT == event then
 665                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
 666                                         debug( "to many connections, seconds to wait for next accept:", delay )
 667                                         return EV_TIMEOUT, delay  -- timeout...
 668                                 else
 669                                         return EV_READ  -- accept again
 670                                 end
 671                         end
 672                         --vdebug("max connection check ok, accepting...")
 673                         local client, err = server:accept()    -- try to accept; TODO: check err
 674                         while client do
 675                                 if interface._connections >= cfg.MAX_CONNECTIONS then
 676                                         client:close( )  -- refuse connection
 677                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
 678                                         return EV_TIMEOUT, delay  -- delay for next accept attempt
 679                                 end
 680                                 local client_ip, client_port = client:getpeername( )
 681                                 interface._connections = interface._connections + 1  -- increase connection count
 682                                 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, sslctx )
 683                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
 684                                 if ssl and sslctx then
 685                                         clientinterface:starttls(sslctx, true)
 686                                 else
 687                                         clientinterface:_start_session( true )
 688                                 end
 689                                 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
 690
 691                                 client, err = server:accept()    -- try to accept again
 692                         end
 693                         return EV_READ
 694                 end
 695
 696                 server:settimeout( 0 )
 697                 setmetatable(interface, interface_mt)
 698                 interfacelist( "add", interface )
 699                 interface:_start_session()
 700                 return interface
 701         end
 702 end
 703
 704 local addserver = ( function( )
 705         return function( addr, port, listener, pattern, sslcfg, startssl )  -- TODO: check arguments
 706                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
 707                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
 708                 if not server then
 709                         debug( "creating server socket on "..addr.." port "..port.." failed:", err )
 710                         return nil, err
 711                 end
 712                 local sslctx
 713                 if sslcfg then
 714                         if not ssl then
 715                                 debug "fatal error: luasec not found"
 716                                 return nil, "luasec not found"
 717                         end
 718                         sslctx, err = sslcfg
 719                         if err then
 720                                 debug( "error while creating new ssl context for server socket:", err )
 721                                 return nil, err
 722                         end
 723                 end
 724                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
 725                 debug( "new server created with id:", tostring(interface))
 726                 return interface
 727         end
 728 end )( )
 729
 730 local addclient, wrapclient
 731 do
 732         function wrapclient( client, ip, port, listeners, pattern, sslctx )
 733                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
 734                 interface:_start_connection(sslctx)
 735                 return interface, client
 736                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 737         end
 738
 739         function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
 740                 local client, err = socket.tcp()  -- creating new socket
 741                 if not client then
 742                         debug( "cannot create socket:", err )
 743                         return nil, err
 744                 end
 745                 client:settimeout( 0 )  -- set nonblocking
 746                 if localaddr then
 747                         local res, err = client:bind( localaddr, localport, -1 )
 748                         if not res then
 749                                 debug( "cannot bind client:", err )
 750                                 return nil, err
 751                         end
 752                 end
 753                 local sslctx
 754                 if sslcfg then  -- handle ssl/new context
 755                         if not ssl then
 756                                 debug "need luasec, but not available"
 757                                 return nil, "luasec not found"
 758                         end
 759                         sslctx, err = sslcfg
 760                         if err then
 761                                 debug( "cannot create new ssl context:", err )
 762                                 return nil, err
 763                         end
 764                 end
 765                 local res, err = client:connect( addr, serverport )  -- connect
 766                 if res or ( err == "timeout" ) then
 767                         local ip, port = client:getsockname( )
 768                         local interface = wrapclient( client, ip, serverport, listener, pattern, sslctx, startssl )
 769                         interface:_start_connection( startssl )
 770                         debug( "new connection id:", interface.id )
 771                         return interface, err
 772                 else
 773                         debug( "new connection failed:", err )
 774                         return nil, err
 775                 end
 776         end
 777 end
 778
 779
 780 local loop = function( )  -- starts the event loop
 781         base:loop( )
 782         return "quitting";
 783 end
 784
 785 local newevent = ( function( )
 786         local add = base.addevent
 787         return function( ... )
 788                 return add( base, ... )
 789         end
 790 end )( )
 791
 792 local closeallservers = function( arg )
 793         for _, item in ipairs( interfacelist( ) ) do
 794                 if item.type == "server" then
 795                         item:close( arg )
 796                 end
 797         end
 798 end
 799
 800 local function setquitting(yes)
 801         if yes then
 802                  -- Quit now
 803                  closeallservers();
 804                  base:loopexit();
 805         end
 806 end
 807
 808 local function get_backend()
 809         return base:method();
 810 end
 811
 812 -- We need to hold onto the events to stop them
 813 -- being garbage-collected
 814 local signal_events = {}; -- [signal_num] -> event object
 815 local function hook_signal(signal_num, handler)
 816         local function _handler(event)
 817                 local ret = handler();
 818                 if ret ~= false then -- Continue handling this signal?
 819                         return EV_SIGNAL; -- Yes
 820                 end
 821                 return -1; -- Close this event
 822         end
 823         signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
 824         return signal_events[signal_num];
 825 end
 826
 827 local function link(sender, receiver, buffersize)
 828         local sender_locked;
 829
 830         function receiver:ondrain()
 831                 if sender_locked then
 832                         sender:resume();
 833                         sender_locked = nil;
 834                 end
 835         end
 836
 837         function sender:onincoming(data)
 838                 receiver:write(data);
 839                 if receiver.writebufferlen >= buffersize then
 840                         sender_locked = true;
 841                         sender:pause();
 842                 end
 843         end
 844 end
 845
 846 return {
 847
 848         cfg = cfg,
 849         base = base,
 850         loop = loop,
 851         link = link,
 852         event = event,
 853         event_base = base,
 854         addevent = newevent,
 855         addserver = addserver,
 856         addclient = addclient,
 857         wrapclient = wrapclient,
 858         setquitting = setquitting,
 859         closeall = closeallservers,
 860         get_backend = get_backend,
 861         hook_signal = hook_signal,
 862
 863         __NAME = SCRIPT_NAME,
 864         __DATE = LAST_MODIFIED,
 865         __AUTHOR = SCRIPT_AUTHOR,
 866         __VERSION = SCRIPT_VERSION,
 867
 868 }