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_QUEUE          = 128,  -- might influence the length of the pending sockets queue
  27         ACCEPT_DELAY          = 10,  -- seconds to wait until the next attempt of a full server to accept
  28         READ_TIMEOUT          = 60 * 60 * 6,  -- timeout in seconds for read data from socket
  29         WRITE_TIMEOUT         = 180,  -- timeout in seconds for write data on socket
  30         CONNECT_TIMEOUT       = 20,  -- timeout in seconds for connection attempts
  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 pairs = use "pairs"
  37 local string = use "string"
  38 local select = use "select"
  39 local require = use "require"
  40 local tostring = use "tostring"
  41 local coroutine = use "coroutine"
  42 local setmetatable = use "setmetatable"
  43
  44 local t_insert = table.insert
  45 local t_concat = table.concat
  46
  47 local has_luasec, ssl = pcall ( require , "ssl" )
  48 local socket = use "socket" or require "socket"
  49 local getaddrinfo = socket.dns.getaddrinfo
  50
  51 local log = require ("util.logger").init("socket")
  52
  53 local function debug(...)
  54         return log("debug", ("%s "):rep(select('#', ...)), ...)
  55 end
  56 local vdebug = debug;
  57
  58 local bitor = ( function( ) -- thx Rici Lake
  59         local hasbit = function( x, p )
  60                 return x % ( p + p ) >= p
  61         end
  62         return function( x, y )
  63                 local p = 1
  64                 local z = 0
  65                 local limit = x > y and x or y
  66                 while p <= limit do
  67                         if hasbit( x, p ) or hasbit( y, p ) then
  68                                 z = z + p
  69                         end
  70                         p = p + p
  71                 end
  72                 return z
  73         end
  74 end )( )
  75
  76 local event = require "luaevent.core"
  77 local base = event.new( )
  78 local EV_READ = event.EV_READ
  79 local EV_WRITE = event.EV_WRITE
  80 local EV_TIMEOUT = event.EV_TIMEOUT
  81 local EV_SIGNAL = event.EV_SIGNAL
  82
  83 local EV_READWRITE = bitor( EV_READ, EV_WRITE )
  84
  85 local interfacelist = { }
  86
  87 -- Client interface methods
  88 local interface_mt
  89 do
  90         interface_mt = {}; interface_mt.__index = interface_mt;
  91
  92         local addevent = base.addevent
  93         local coroutine_wrap, coroutine_yield = coroutine.wrap,coroutine.yield
  94
  95         -- Private methods
  96         function interface_mt:_close()
  97                 return self:_destroy();
  98         end
  99
 100         function interface_mt:_start_connection(plainssl) -- should be called from addclient
 101                         local callback = function( event )
 102                                 if EV_TIMEOUT == event then  -- timeout during connection
 103                                         self.fatalerror = "connection timeout"
 104                                         self:ontimeout()  -- call timeout listener
 105                                         self:_close()
 106                                         debug( "new connection failed. id:", self.id, "error:", self.fatalerror )
 107                                 else
 108                                         if plainssl and has_luasec then  -- start ssl session
 109                                                 self:starttls(self._sslctx, true)
 110                                         else  -- normal connection
 111                                                 self:_start_session(true)
 112                                         end
 113                                         debug( "new connection established. id:", self.id )
 114                                 end
 115                                 self.eventconnect = nil
 116                                 return -1
 117                         end
 118                         self.eventconnect = addevent( base, self.conn, EV_WRITE, callback, cfg.CONNECT_TIMEOUT )
 119                         return true
 120         end
 121         function interface_mt:_start_session(call_onconnect) -- new session, for example after startssl
 122                 if self.type == "client" then
 123                         local callback = function( )
 124                                 self:_lock( false,  false, false )
 125                                 --vdebug( "start listening on client socket with id:", self.id )
 126                                 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 127                                 if call_onconnect then
 128                                         self:onconnect()
 129                                 end
 130                                 self.eventsession = nil
 131                                 return -1
 132                         end
 133                         self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 134                 else
 135                         self:_lock( false )
 136                         --vdebug( "start listening on server socket with id:", self.id )
 137                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback )  -- register callback
 138                 end
 139                 return true
 140         end
 141         function interface_mt:_start_ssl(call_onconnect) -- old socket will be destroyed, therefore we have to close read/write events first
 142                         --vdebug( "starting ssl session with client id:", self.id )
 143                         local _
 144                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 145                         _ = self.eventwrite and self.eventwrite:close( )
 146                         self.eventread, self.eventwrite = nil, nil
 147                         local err
 148                         self.conn, err = ssl.wrap( self.conn, self._sslctx )
 149                         if err then
 150                                 self.fatalerror = err
 151                                 self.conn = nil  -- cannot be used anymore
 152                                 if call_onconnect then
 153                                         self.ondisconnect = nil  -- dont call this when client isnt really connected
 154                                 end
 155                                 self:_close()
 156                                 debug( "fatal error while ssl wrapping:", err )
 157                                 return false
 158                         end
 159                         self.conn:settimeout( 0 )  -- set non blocking
 160                         local handshakecallback = coroutine_wrap(
 161                                 function( event )
 162                                         local _, err
 163                                         local attempt = 0
 164                                         local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPTS
 165                                         while attempt < maxattempt do  -- no endless loop
 166                                                 attempt = attempt + 1
 167                                                 debug( "ssl handshake of client with id:"..tostring(self)..", attempt:"..attempt )
 168                                                 if attempt > maxattempt then
 169                                                         self.fatalerror = "max handshake attempts exceeded"
 170                                                 elseif EV_TIMEOUT == event then
 171                                                         self.fatalerror = "timeout during handshake"
 172                                                 else
 173                                                         _, err = self.conn:dohandshake( )
 174                                                         if not err then
 175                                                                 self:_lock( false, false, false )  -- unlock the interface; sending, closing etc allowed
 176                                                                 self.send = self.conn.send  -- caching table lookups with new client object
 177                                                                 self.receive = self.conn.receive
 178                                                                 if not call_onconnect then  -- trigger listener
 179                                                                         self:onstatus("ssl-handshake-complete");
 180                                                                 end
 181                                                                 self:_start_session( call_onconnect )
 182                                                                 debug( "ssl handshake done" )
 183                                                                 self.eventhandshake = nil
 184                                                                 return -1
 185                                                         end
 186                                                         if err == "wantwrite" then
 187                                                                 event = EV_WRITE
 188                                                         elseif err == "wantread" then
 189                                                                 event = EV_READ
 190                                                         else
 191                                                                 debug( "ssl handshake error:", err )
 192                                                                 self.fatalerror = err
 193                                                         end
 194                                                 end
 195                                                 if self.fatalerror then
 196                                                         if call_onconnect then
 197                                                                 self.ondisconnect = nil  -- dont call this when client isnt really connected
 198                                                         end
 199                                                         self:_close()
 200                                                         debug( "handshake failed because:", self.fatalerror )
 201                                                         self.eventhandshake = nil
 202                                                         return -1
 203                                                 end
 204                                                 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT )  -- yield this monster...
 205                                         end
 206                                 end
 207                         )
 208                         debug "starting handshake..."
 209                         self:_lock( false, true, true )  -- unlock read/write events, but keep interface locked
 210                         self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
 211                         return true
 212         end
 213         function interface_mt:_destroy()  -- close this interface + events and call last listener
 214                         debug( "closing client with id:", self.id, self.fatalerror )
 215                         self:_lock( true, true, true )  -- first of all, lock the interface to avoid further actions
 216                         local _
 217                         _ = self.eventread and self.eventread:close( )
 218                         if self.type == "client" then
 219                                 _ = self.eventwrite and self.eventwrite:close( )
 220                                 _ = self.eventhandshake and self.eventhandshake:close( )
 221                                 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
 222                                 _ = self.eventconnect and self.eventconnect:close( )
 223                                 _ = self.eventsession and self.eventsession:close( )
 224                                 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
 225                                 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
 226                                 _ = 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)
 227                                 _ = self.conn and self.conn:close( ) -- close connection
 228                                 _ = self._server and self._server:counter(-1);
 229                                 self.eventread, self.eventwrite = nil, nil
 230                                 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
 231                                 self.readcallback, self.writecallback = nil, nil
 232                         else
 233                                 self.conn:close( )
 234                                 self.eventread, self.eventclose = nil, nil
 235                                 self.interface, self.readcallback = nil, nil
 236                         end
 237                         interfacelist[ self ] = nil
 238                         return true
 239         end
 240
 241         function interface_mt:_lock(nointerface, noreading, nowriting)  -- lock or unlock this interface or events
 242                         self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
 243                         return nointerface, noreading, nowriting
 244         end
 245
 246         --TODO: Deprecate
 247         function interface_mt:lock_read(switch)
 248                 if switch then
 249                         return self:pause();
 250                 else
 251                         return self:resume();
 252                 end
 253         end
 254
 255         function interface_mt:pause()
 256                 return self:_lock(self.nointerface, true, self.nowriting);
 257         end
 258
 259         function interface_mt:resume()
 260                 self:_lock(self.nointerface, false, self.nowriting);
 261                 if not self.eventread then
 262                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 263                 end
 264         end
 265
 266         function interface_mt:counter(c)
 267                 if c then
 268                         self._connections = self._connections + c
 269                 end
 270                 return self._connections
 271         end
 272
 273         -- Public methods
 274         function interface_mt:write(data)
 275                 if self.nowriting then return nil, "locked" end
 276                 --vdebug( "try to send data to client, id/data:", self.id, data )
 277                 data = tostring( data )
 278                 local len = #data
 279                 local total = len + self.writebufferlen
 280                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
 281                         local err = "send buffer exceeded"
 282                         debug( "error:", err )  -- to much, check your app
 283                         return nil, err
 284                 end
 285                 t_insert(self.writebuffer, data) -- new buffer
 286                 self.writebufferlen = total
 287                 if not self.eventwrite then  -- register new write event
 288                         --vdebug( "register new write event" )
 289                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
 290                 end
 291                 return true
 292         end
 293         function interface_mt:close()
 294                 if self.nointerface then return nil, "locked"; end
 295                 debug( "try to close client connection with id:", self.id )
 296                 if self.type == "client" then
 297                         self.fatalerror = "client to close"
 298                         if self.eventwrite then -- wait for incomplete write request
 299                                 self:_lock( true, true, false )
 300                                 debug "closing delayed until writebuffer is empty"
 301                                 return nil, "writebuffer not empty, waiting"
 302                         else -- close now
 303                                 self:_lock( true, true, true )
 304                                 self:_close()
 305                                 return true
 306                         end
 307                 else
 308                         debug( "try to close server with id:", tostring(self.id))
 309                         self.fatalerror = "server to close"
 310                         self:_lock( true )
 311                         self:_close( 0 )
 312                         return true
 313                 end
 314         end
 315
 316         function interface_mt:socket()
 317                 return self.conn
 318         end
 319
 320         function interface_mt:server()
 321                 return self._server or self;
 322         end
 323
 324         function interface_mt:port()
 325                 return self._port
 326         end
 327
 328         function interface_mt:serverport()
 329                 return self._serverport
 330         end
 331
 332         function interface_mt:ip()
 333                 return self._ip
 334         end
 335
 336         function interface_mt:ssl()
 337                 return self._usingssl
 338         end
 339         interface_mt.clientport = interface_mt.port -- COMPAT server_select
 340
 341         function interface_mt:type()
 342                 return self._type or "client"
 343         end
 344
 345         function interface_mt:connections()
 346                 return self._connections
 347         end
 348
 349         function interface_mt:address()
 350                 return self.addr
 351         end
 352
 353         function interface_mt:set_sslctx(sslctx)
 354                 self._sslctx = sslctx;
 355                 if sslctx then
 356                         self.starttls = nil; -- use starttls() of interface_mt
 357                 else
 358                         self.starttls = false; -- prevent starttls()
 359                 end
 360         end
 361
 362         function interface_mt:set_mode(pattern)
 363                 if pattern then
 364                         self._pattern = pattern;
 365                 end
 366                 return self._pattern;
 367         end
 368
 369         function interface_mt:set_send(new_send)
 370                 -- No-op, we always use the underlying connection's send
 371         end
 372
 373         function interface_mt:starttls(sslctx, call_onconnect)
 374                 debug( "try to start ssl at client id:", self.id )
 375                 local err
 376                 self._sslctx = sslctx;
 377                 if self._usingssl then  -- startssl was already called
 378                         err = "ssl already active"
 379                 end
 380                 if err then
 381                         debug( "error:", err )
 382                         return nil, err
 383                 end
 384                 self._usingssl = true
 385                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
 386                         self.startsslcallback = nil
 387                         self:_start_ssl(call_onconnect);
 388                         self.eventstarthandshake = nil
 389                         return -1
 390                 end
 391                 if not self.eventwrite then
 392                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
 393                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
 394                 else  -- wait until writebuffer is empty
 395                         self:_lock( true, true, false )
 396                         debug "ssl session delayed until writebuffer is empty..."
 397                 end
 398                 self.starttls = false;
 399                 return true
 400         end
 401
 402         function interface_mt:setoption(option, value)
 403                 if self.conn.setoption then
 404                         return self.conn:setoption(option, value);
 405                 end
 406                 return false, "setoption not implemented";
 407         end
 408
 409         function interface_mt:setlistener(listener)
 410                 self:ondetach(); -- Notify listener that it is no longer responsible for this connection
 411                 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout,
 412                 self.onreadtimeout, self.onstatus, self.ondetach
 413                         = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout,
 414                           listener.onreadtimeout, listener.onstatus, listener.ondetach;
 415         end
 416
 417         -- Stub handlers
 418         function interface_mt:onconnect()
 419         end
 420         function interface_mt:onincoming()
 421         end
 422         function interface_mt:ondisconnect()
 423         end
 424         function interface_mt:ontimeout()
 425         end
 426         function interface_mt:onreadtimeout()
 427                 self.fatalerror = "timeout during receiving"
 428                 debug( "connection failed:", self.fatalerror )
 429                 self:_close()
 430                 self.eventread = nil
 431         end
 432         function interface_mt:ondrain()
 433         end
 434         function interface_mt:ondetach()
 435         end
 436         function interface_mt:onstatus()
 437         end
 438 end
 439
 440 -- End of client interface methods
 441
 442 local handleclient;
 443 do
 444         local string_sub = string.sub  -- caching table lookups
 445         local addevent = base.addevent
 446         local socket_gettime = socket.gettime
 447         function handleclient( client, ip, port, server, pattern, listener, sslctx )  -- creates an client interface
 448                 --vdebug("creating client interfacce...")
 449                 local interface = {
 450                         type = "client";
 451                         conn = client;
 452                         currenttime = socket_gettime( );  -- safe the origin
 453                         writebuffer = {};  -- writebuffer
 454                         writebufferlen = 0;  -- length of writebuffer
 455                         send = client.send;  -- caching table lookups
 456                         receive = client.receive;
 457                         onconnect = listener.onconnect;  -- will be called when client disconnects
 458                         ondisconnect = listener.ondisconnect;  -- will be called when client disconnects
 459                         onincoming = listener.onincoming;  -- will be called when client sends data
 460                         ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
 461                         onreadtimeout = listener.onreadtimeout; -- called when socket inactivity timeout occurs
 462                         ondrain = listener.ondrain; -- called when writebuffer is empty
 463                         ondetach = listener.ondetach; -- called when disassociating this listener from this connection
 464                         onstatus = listener.onstatus; -- called for status changes (e.g. of SSL/TLS)
 465                         eventread = false, eventwrite = false, eventclose = false,
 466                         eventhandshake = false, eventstarthandshake = false;  -- event handler
 467                         eventconnect = false, eventsession = false;  -- more event handler...
 468                         eventwritetimeout = false;  -- even more event handler...
 469                         eventreadtimeout = false;
 470                         fatalerror = false;  -- error message
 471                         writecallback = false;  -- will be called on write events
 472                         readcallback = false;  -- will be called on read events
 473                         nointerface = true;  -- lock/unlock parameter of this interface
 474                         noreading = false, nowriting = false;  -- locks of the read/writecallback
 475                         startsslcallback = false;  -- starting handshake callback
 476                         position = false;  -- position of client in interfacelist
 477
 478                         -- Properties
 479                         _ip = ip, _port = port, _server = server, _pattern = pattern,
 480                         _serverport = (server and server:port() or nil),
 481                         _sslctx = sslctx; -- parameters
 482                         _usingssl = false;  -- client is using ssl;
 483                 }
 484                 if not has_luasec then interface.starttls = false; end
 485                 interface.id = tostring(interface):match("%x+$");
 486                 interface.writecallback = function( event )  -- called on write events
 487                         --vdebug( "new client write event, id/ip/port:", interface, ip, port )
 488                         if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then  -- leave this event
 489                                 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
 490                                 interface.eventwrite = false
 491                                 return -1
 492                         end
 493                         if EV_TIMEOUT == event then  -- took too long to write some data to socket -> disconnect
 494                                 interface.fatalerror = "timeout during writing"
 495                                 debug( "writing failed:", interface.fatalerror )
 496                                 interface:_close()
 497                                 interface.eventwrite = false
 498                                 return -1
 499                         else  -- can write :)
 500                                 if interface._usingssl then  -- handle luasec
 501                                         if interface.eventreadtimeout then  -- we have to read first
 502                                                 local ret = interface.readcallback( )  -- call readcallback
 503                                                 --vdebug( "tried to read in writecallback, result:", ret )
 504                                         end
 505                                         if interface.eventwritetimeout then  -- luasec only
 506                                                 interface.eventwritetimeout:close( )  -- first we have to close timeout event which where regged after a wantread error
 507                                                 interface.eventwritetimeout = false
 508                                         end
 509                                 end
 510                                 interface.writebuffer = { t_concat(interface.writebuffer) }
 511                                 local succ, err, byte = interface.conn:send( interface.writebuffer[1], 1, interface.writebufferlen )
 512                                 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
 513                                 if succ then  -- writing succesful
 514                                         interface.writebuffer[1] = nil
 515                                         interface.writebufferlen = 0
 516                                         interface:ondrain();
 517                                         if interface.fatalerror then
 518                                                 debug "closing client after writing"
 519                                                 interface:_close()  -- close interface if needed
 520                                         elseif interface.startsslcallback then  -- start ssl connection if needed
 521                                                 debug "starting ssl handshake after writing"
 522                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
 523                                         elseif interface.eventreadtimeout then
 524                                                 return EV_WRITE, EV_TIMEOUT
 525                                         end
 526                                         interface.eventwrite = nil
 527                                         return -1
 528                                 elseif byte and (err == "timeout" or err == "wantwrite") then  -- want write again
 529                                         --vdebug( "writebuffer is not empty:", err )
 530                                         interface.writebuffer[1] = string_sub( interface.writebuffer[1], byte + 1, interface.writebufferlen )  -- new buffer
 531                                         interface.writebufferlen = interface.writebufferlen - byte
 532                                         if "wantread" == err then  -- happens only with luasec
 533                                                 local callback = function( )
 534                                                         interface:_close()
 535                                                         interface.eventwritetimeout = nil
 536                                                         return -1;
 537                                                 end
 538                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
 539                                                 debug( "wantread during write attempt, reg it in readcallback but dont know what really happens next..." )
 540                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
 541                                                 return -1
 542                                         end
 543                                         return EV_WRITE, cfg.WRITE_TIMEOUT
 544                                 else  -- connection was closed during writing or fatal error
 545                                         interface.fatalerror = err or "fatal error"
 546                                         debug( "connection failed in write event:", interface.fatalerror )
 547                                         interface:_close()
 548                                         interface.eventwrite = nil
 549                                         return -1
 550                                 end
 551                         end
 552                 end
 553
 554                 interface.readcallback = function( event )  -- called on read events
 555                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
 556                         if interface.noreading or interface.fatalerror then  -- leave this event
 557                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
 558                                 interface.eventread = nil
 559                                 return -1
 560                         end
 561                         if EV_TIMEOUT == event and interface:onreadtimeout() ~= true then
 562                                 return -1 -- took too long to get some data from client -> disconnect
 563                         end
 564                         if interface._usingssl then  -- handle luasec
 565                                 if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
 566                                         local ret = interface.writecallback( )  -- call it
 567                                         --vdebug( "tried to write in readcallback, result:", tostring(ret) )
 568                                 end
 569                                 if interface.eventreadtimeout then
 570                                         interface.eventreadtimeout:close( )
 571                                         interface.eventreadtimeout = nil
 572                                 end
 573                         end
 574                         local buffer, err, part = interface.conn:receive( interface._pattern )  -- receive buffer with "pattern"
 575                         --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
 576                         buffer = buffer or part
 577                         if buffer and #buffer > cfg.MAX_READ_LENGTH then  -- check buffer length
 578                                 interface.fatalerror = "receive buffer exceeded"
 579                                 debug( "fatal error:", interface.fatalerror )
 580                                 interface:_close()
 581                                 interface.eventread = nil
 582                                 return -1
 583                         end
 584                         if err and ( err ~= "timeout" and err ~= "wantread" ) then
 585                                 if "wantwrite" == err then -- need to read on write event
 586                                         if not interface.eventwrite then  -- register new write event if needed
 587                                                 interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
 588                                         end
 589                                         interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
 590                                                 function( )
 591                                                         interface:_close()
 592                                                 end, cfg.READ_TIMEOUT
 593                                         )
 594                                         debug( "wantwrite during read attempt, reg it in writecallback but dont know what really happens next..." )
 595                                         -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
 596                                 else  -- connection was closed or fatal error
 597                                         interface.fatalerror = err
 598                                         debug( "connection failed in read event:", interface.fatalerror )
 599                                         interface:_close()
 600                                         interface.eventread = nil
 601                                         return -1
 602                                 end
 603                         else
 604                                 interface.onincoming( interface, buffer, err )  -- send new data to listener
 605                         end
 606                         if interface.noreading then
 607                                 interface.eventread = nil;
 608                                 return -1;
 609                         end
 610                         return EV_READ, cfg.READ_TIMEOUT
 611                 end
 612
 613                 client:settimeout( 0 )  -- set non blocking
 614                 setmetatable(interface, interface_mt)
 615                 interfacelist[ interface ] = true  -- add to interfacelist
 616                 return interface
 617         end
 618 end
 619
 620 local handleserver
 621 do
 622         function handleserver( server, addr, port, pattern, listener, sslctx )  -- creates an server interface
 623                 debug "creating server interface..."
 624                 local interface = {
 625                         _connections = 0;
 626
 627                         conn = server;
 628                         onconnect = listener.onconnect;  -- will be called when new client connected
 629                         eventread = false;  -- read event handler
 630                         eventclose = false; -- close event handler
 631                         readcallback = false; -- read event callback
 632                         fatalerror = false; -- error message
 633                         nointerface = true;  -- lock/unlock parameter
 634
 635                         _ip = addr, _port = port, _pattern = pattern,
 636                         _sslctx = sslctx;
 637                 }
 638                 interface.id = tostring(interface):match("%x+$");
 639                 interface.readcallback = function( event )  -- server handler, called on incoming connections
 640                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
 641                         if interface.fatalerror then
 642                                 --vdebug( "leaving this event because:", self.fatalerror )
 643                                 interface.eventread = nil
 644                                 return -1
 645                         end
 646                         local delay = cfg.ACCEPT_DELAY
 647                         if EV_TIMEOUT == event then
 648                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
 649                                         debug( "to many connections, seconds to wait for next accept:", delay )
 650                                         return EV_TIMEOUT, delay  -- timeout...
 651                                 else
 652                                         return EV_READ  -- accept again
 653                                 end
 654                         end
 655                         --vdebug("max connection check ok, accepting...")
 656                         local client, err = server:accept()    -- try to accept; TODO: check err
 657                         while client do
 658                                 if interface._connections >= cfg.MAX_CONNECTIONS then
 659                                         client:close( )  -- refuse connection
 660                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
 661                                         return EV_TIMEOUT, delay  -- delay for next accept attempt
 662                                 end
 663                                 local client_ip, client_port = client:getpeername( )
 664                                 interface._connections = interface._connections + 1  -- increase connection count
 665                                 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, sslctx )
 666                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
 667                                 if has_luasec and sslctx then
 668                                         clientinterface:starttls(sslctx, true)
 669                                 else
 670                                         clientinterface:_start_session( true )
 671                                 end
 672                                 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
 673
 674                                 client, err = server:accept()    -- try to accept again
 675                         end
 676                         return EV_READ
 677                 end
 678
 679                 server:settimeout( 0 )
 680                 setmetatable(interface, interface_mt)
 681                 interfacelist[ interface ] = true
 682                 interface:_start_session()
 683                 return interface
 684         end
 685 end
 686
 687 local addserver = ( function( )
 688         return function( addr, port, listener, pattern, sslctx, startssl )  -- TODO: check arguments
 689                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslctx or "nil", startssl or "nil")
 690                 if sslctx and not has_luasec then
 691                         debug "fatal error: luasec not found"
 692                         return nil, "luasec not found"
 693                 end
 694                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
 695                 if not server then
 696                         debug( "creating server socket on "..addr.." port "..port.." failed:", err )
 697                         return nil, err
 698                 end
 699                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
 700                 debug( "new server created with id:", tostring(interface))
 701                 return interface
 702         end
 703 end )( )
 704
 705 local addclient, wrapclient
 706 do
 707         function wrapclient( client, ip, port, listeners, pattern, sslctx )
 708                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
 709                 interface:_start_connection(sslctx)
 710                 return interface, client
 711                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 712         end
 713
 714         function addclient( addr, serverport, listener, pattern, sslctx, typ )
 715                 if sslctx and not has_luasec then
 716                         debug "need luasec, but not available"
 717                         return nil, "luasec not found"
 718                 end
 719                 if not typ then
 720                         local addrinfo, err = getaddrinfo(addr)
 721                         if not addrinfo then return nil, err end
 722                         if addrinfo[1] and addrinfo[1].family == "inet6" then
 723                                 typ = "tcp6"
 724                         else
 725                                 typ = "tcp"
 726                         end
 727                 end
 728                 local create = socket[typ]
 729                 if type( create ) ~= "function"  then
 730                         return nil, "invalid socket type"
 731                 end
 732                 local client, err = create()  -- creating new socket
 733                 if not client then
 734                         debug( "cannot create socket:", err )
 735                         return nil, err
 736                 end
 737                 client:settimeout( 0 )  -- set nonblocking
 738                 local res, err = client:connect( addr, serverport )  -- connect
 739                 if res or ( err == "timeout" ) then
 740                         local ip, port = client:getsockname( )
 741                         local interface = wrapclient( client, ip, serverport, listener, pattern, sslctx )
 742                         interface:_start_connection( startssl )
 743                         debug( "new connection id:", interface.id )
 744                         return interface, err
 745                 else
 746                         debug( "new connection failed:", err )
 747                         return nil, err
 748                 end
 749         end
 750 end
 751
 752
 753 local loop = function( )  -- starts the event loop
 754         base:loop( )
 755         return "quitting";
 756 end
 757
 758 local newevent = ( function( )
 759         local add = base.addevent
 760         return function( ... )
 761                 return add( base, ... )
 762         end
 763 end )( )
 764
 765 local closeallservers = function( arg )
 766         for item in pairs( interfacelist ) do
 767                 if item.type == "server" then
 768                         item:close( arg )
 769                 end
 770         end
 771 end
 772
 773 local function setquitting(yes)
 774         if yes then
 775                  -- Quit now
 776                  closeallservers();
 777                  base:loopexit();
 778         end
 779 end
 780
 781 local function get_backend()
 782         return base:method();
 783 end
 784
 785 -- We need to hold onto the events to stop them
 786 -- being garbage-collected
 787 local signal_events = {}; -- [signal_num] -> event object
 788 local function hook_signal(signal_num, handler)
 789         local function _handler(event)
 790                 local ret = handler();
 791                 if ret ~= false then -- Continue handling this signal?
 792                         return EV_SIGNAL; -- Yes
 793                 end
 794                 return -1; -- Close this event
 795         end
 796         signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
 797         return signal_events[signal_num];
 798 end
 799
 800 local function link(sender, receiver, buffersize)
 801         local sender_locked;
 802
 803         function receiver:ondrain()
 804                 if sender_locked then
 805                         sender:resume();
 806                         sender_locked = nil;
 807                 end
 808         end
 809
 810         function sender:onincoming(data)
 811                 receiver:write(data);
 812                 if receiver.writebufferlen >= buffersize then
 813                         sender_locked = true;
 814                         sender:pause();
 815                 end
 816         end
 817         sender:set_mode("*a");
 818 end
 819
 820 return {
 821
 822         cfg = cfg,
 823         base = base,
 824         loop = loop,
 825         link = link,
 826         event = event,
 827         event_base = base,
 828         addevent = newevent,
 829         addserver = addserver,
 830         addclient = addclient,
 831         wrapclient = wrapclient,
 832         setquitting = setquitting,
 833         closeall = closeallservers,
 834         get_backend = get_backend,
 835         hook_signal = hook_signal,
 836
 837         __NAME = SCRIPT_NAME,
 838         __DATE = LAST_MODIFIED,
 839         __AUTHOR = SCRIPT_AUTHOR,
 840         __VERSION = SCRIPT_VERSION,
 841
 842 }