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