net/server_event.lua

   1 --[[
   2
   3
   4                         server.lua based on lua/libevent by blastbeat
   5
   6                         notes:
   7                         -- when using luaevent, never register 2 or more EV_READ at one socket, same for EV_WRITE
   8                         -- you cant even register a new EV_READ/EV_WRITE callback inside another one
   9                         -- to do some of the above, use timeout events or something what will called from outside
  10                         -- dont let garbagecollect eventcallbacks, as long they are running
  11                         -- when using luasec, there are 4 cases of timeout errors: wantread or wantwrite during reading or writing
  12
  13 --]]
  14
  15 local SCRIPT_NAME           = "server_event.lua"
  16 local SCRIPT_VERSION        = "0.05"
  17 local SCRIPT_AUTHOR         = "blastbeat"
  18 local LAST_MODIFIED         = "2009/11/20"
  19
  20 local cfg = {
  21         MAX_CONNECTIONS       = 100000,  -- max per server connections (use "ulimit -n" on *nix)
  22         MAX_HANDSHAKE_ATTEMPTS= 1000,  -- attempts to finish ssl handshake
  23         HANDSHAKE_TIMEOUT     = 60,  -- timeout in seconds per handshake attempt
  24         MAX_READ_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes allowed to read from sockets
  25         MAX_SEND_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes size of write buffer (for writing on sockets)
  26         ACCEPT_DELAY          = 10,  -- seconds to wait until the next attempt of a full server to accept
  27         READ_TIMEOUT          = 60 * 60 * 6,  -- timeout in seconds for read data from socket
  28         WRITE_TIMEOUT         = 180,  -- timeout in seconds for write data on socket
  29         CONNECT_TIMEOUT       = 20,  -- timeout in seconds for connection attempts
  30         CLEAR_DELAY           = 5,  -- seconds to wait for clearing interface list (and calling ondisconnect listeners)
  31         DEBUG                 = true,  -- show debug messages
  32 }
  33
  34 local function use(x) return rawget(_G, x); end
  35 local ipairs = use "ipairs"
  36 local string = use "string"
  37 local select = use "select"
  38 local require = use "require"
  39 local tostring = use "tostring"
  40 local coroutine = use "coroutine"
  41 local setmetatable = use "setmetatable"
  42
  43 local t_insert = table.insert
  44 local t_concat = table.concat
  45
  46 local ssl = use "ssl"
  47 local socket = use "socket" or require "socket"
  48
  49 local log = require ("util.logger").init("socket")
  50
  51 local function debug(...)
  52         return log("debug", ("%s "):rep(select('#', ...)), ...)
  53 end
  54 local vdebug = debug;
  55
  56 local bitor = ( function( ) -- thx Rici Lake
  57         local hasbit = function( x, p )
  58                 return x % ( p + p ) >= p
  59         end
  60         return function( x, y )
  61                 local p = 1
  62                 local z = 0
  63                 local limit = x > y and x or y
  64                 while p <= limit do
  65                         if hasbit( x, p ) or hasbit( y, p ) then
  66                                 z = z + p
  67                         end
  68                         p = p + p
  69                 end
  70                 return z
  71         end
  72 end )( )
  73
  74 local event = require "luaevent.core"
  75 local base = event.new( )
  76 local EV_READ = event.EV_READ
  77 local EV_WRITE = event.EV_WRITE
  78 local EV_TIMEOUT = event.EV_TIMEOUT
  79 local EV_SIGNAL = event.EV_SIGNAL
  80
  81 local EV_READWRITE = bitor( EV_READ, EV_WRITE )
  82
  83 local interfacelist = ( function( )  -- holds the interfaces for sockets
  84         local array = { }
  85         local len = 0
  86         return function( method, arg )
  87                 if "add" == method then
  88                         len = len + 1
  89                         array[ len ] = arg
  90                         arg:_position( len )
  91                         return len
  92                 elseif "delete" == method then
  93                         if len <= 0 then
  94                                 return nil, "array is already empty"
  95                         end
  96                         local position = arg:_position()  -- get position in array
  97                         if position ~= len then
  98                                 local interface = array[ len ]  -- get last interface
  99                                 array[ position ] = interface  -- copy it into free position
 100                                 array[ len ] = nil  -- free last position
 101                                 interface:_position( position )  -- set new position in array
 102                         else  -- free last position
 103                                 array[ len ] = nil
 104                         end
 105                         len = len - 1
 106                         return len
 107                 else
 108                         return array
 109                 end
 110         end
 111 end )( )
 112
 113 -- Client interface methods
 114 local interface_mt
 115 do
 116         interface_mt = {}; interface_mt.__index = interface_mt;
 117
 118         local addevent = base.addevent
 119         local coroutine_wrap, coroutine_yield = coroutine.wrap,coroutine.yield
 120
 121         -- Private methods
 122         function interface_mt:_position(new_position)
 123                         self.position = new_position or self.position
 124                         return self.position;
 125         end
 126         function interface_mt:_close()
 127                 return self:_destroy();
 128         end
 129
 130         function interface_mt:_start_connection(plainssl) -- should be called from addclient
 131                         local callback = function( event )
 132                                 if EV_TIMEOUT == event then  -- timeout during connection
 133                                         self.fatalerror = "connection timeout"
 134                                         self:ontimeout()  -- call timeout listener
 135                                         self:_close()
 136                                         debug( "new connection failed. id:", self.id, "error:", self.fatalerror )
 137                                 else
 138                                         if plainssl and ssl then  -- start ssl session
 139                                                 self:starttls(self._sslctx, true)
 140                                         else  -- normal connection
 141                                                 self:_start_session(true)
 142                                         end
 143                                         debug( "new connection established. id:", self.id )
 144                                 end
 145                                 self.eventconnect = nil
 146                                 return -1
 147                         end
 148                         self.eventconnect = addevent( base, self.conn, EV_WRITE, callback, cfg.CONNECT_TIMEOUT )
 149                         return true
 150         end
 151         function interface_mt:_start_session(call_onconnect) -- new session, for example after startssl
 152                 if self.type == "client" then
 153                         local callback = function( )
 154                                 self:_lock( false,  false, false )
 155                                 --vdebug( "start listening on client socket with id:", self.id )
 156                                 self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 157                                 if call_onconnect then
 158                                         self:onconnect()
 159                                 end
 160                                 self.eventsession = nil
 161                                 return -1
 162                         end
 163                         self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 164                 else
 165                         self:_lock( false )
 166                         --vdebug( "start listening on server socket with id:", self.id )
 167                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback )  -- register callback
 168                 end
 169                 return true
 170         end
 171         function interface_mt:_start_ssl(call_onconnect) -- old socket will be destroyed, therefore we have to close read/write events first
 172                         --vdebug( "starting ssl session with client id:", self.id )
 173                         local _
 174                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 175                         _ = self.eventwrite and self.eventwrite:close( )
 176                         self.eventread, self.eventwrite = nil, nil
 177                         local err
 178                         self.conn, err = ssl.wrap( self.conn, self._sslctx )
 179                         if err then
 180                                 self.fatalerror = err
 181                                 self.conn = nil  -- cannot be used anymore
 182                                 if call_onconnect then
 183                                         self.ondisconnect = nil  -- dont call this when client isnt really connected
 184                                 end
 185                                 self:_close()
 186                                 debug( "fatal error while ssl wrapping:", err )
 187                                 return false
 188                         end
 189                         self.conn:settimeout( 0 )  -- set non blocking
 190                         local handshakecallback = coroutine_wrap(
 191                                 function( event )
 192                                         local _, err
 193                                         local attempt = 0
 194                                         local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPTS
 195                                         while attempt < maxattempt do  -- no endless loop
 196                                                 attempt = attempt + 1
 197                                                 debug( "ssl handshake of client with id:"..tostring(self)..", attempt:"..attempt )
 198                                                 if attempt > maxattempt then
 199                                                         self.fatalerror = "max handshake attempts exceeded"
 200                                                 elseif EV_TIMEOUT == event then
 201                                                         self.fatalerror = "timeout during handshake"
 202                                                 else
 203                                                         _, err = self.conn:dohandshake( )
 204                                                         if not err then
 205                                                                 self:_lock( false, false, false )  -- unlock the interface; sending, closing etc allowed
 206                                                                 self.send = self.conn.send  -- caching table lookups with new client object
 207                                                                 self.receive = self.conn.receive
 208                                                                 if not call_onconnect then  -- trigger listener
 209                                                                         self:onstatus("ssl-handshake-complete");
 210                                                                 end
 211                                                                 self:_start_session( call_onconnect )
 212                                                                 debug( "ssl handshake done" )
 213                                                                 self.eventhandshake = nil
 214                                                                 return -1
 215                                                         end
 216                                                         if err == "wantwrite" then
 217                                                                 event = EV_WRITE
 218                                                         elseif err == "wantread" then
 219                                                                 event = EV_READ
 220                                                         else
 221                                                                 debug( "ssl handshake error:", err )
 222                                                                 self.fatalerror = err
 223                                                         end
 224                                                 end
 225                                                 if self.fatalerror then
 226                                                         if call_onconnect then
 227                                                                 self.ondisconnect = nil  -- dont call this when client isnt really connected
 228                                                         end
 229                                                         self:_close()
 230                                                         debug( "handshake failed because:", self.fatalerror )
 231                                                         self.eventhandshake = nil
 232                                                         return -1
 233                                                 end
 234                                                 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT )  -- yield this monster...
 235                                         end
 236                                 end
 237                         )
 238                         debug "starting handshake..."
 239                         self:_lock( false, true, true )  -- unlock read/write events, but keep interface locked
 240                         self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
 241                         return true
 242         end
 243         function interface_mt:_destroy()  -- close this interface + events and call last listener
 244                         debug( "closing client with id:", self.id, self.fatalerror )
 245                         self:_lock( true, true, true )  -- first of all, lock the interface to avoid further actions
 246                         local _
 247                         _ = self.eventread and self.eventread:close( )
 248                         if self.type == "client" then
 249                                 _ = self.eventwrite and self.eventwrite:close( )
 250                                 _ = self.eventhandshake and self.eventhandshake:close( )
 251                                 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
 252                                 _ = self.eventconnect and self.eventconnect:close( )
 253                                 _ = self.eventsession and self.eventsession:close( )
 254                                 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
 255                                 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
 256                                 _ = 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)
 257                                 _ = self.conn and self.conn:close( ) -- close connection
 258                                 _ = self._server and self._server:counter(-1);
 259                                 self.eventread, self.eventwrite = nil, nil
 260                                 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
 261                                 self.readcallback, self.writecallback = nil, nil
 262                         else
 263                                 self.conn:close( )
 264                                 self.eventread, self.eventclose = nil, nil
 265                                 self.interface, self.readcallback = nil, nil
 266                         end
 267                         interfacelist( "delete", self )
 268                         return true
 269         end
 270
 271         function interface_mt:_lock(nointerface, noreading, nowriting)  -- lock or unlock this interface or events
 272                         self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
 273                         return nointerface, noreading, nowriting
 274         end
 275
 276         --TODO: Deprecate
 277         function interface_mt:lock_read(switch)
 278                 if switch then
 279                         return self:pause();
 280                 else
 281                         return self:resume();
 282                 end
 283         end
 284
 285         function interface_mt:pause()
 286                 return self:_lock(self.nointerface, true, self.nowriting);
 287         end
 288
 289         function interface_mt:resume()
 290                 self:_lock(self.nointerface, false, self.nowriting);
 291                 if not self.eventread then
 292                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback, cfg.READ_TIMEOUT );  -- register callback
 293                 end
 294         end
 295
 296         function interface_mt:counter(c)
 297                 if c then
 298                         self._connections = self._connections + c
 299                 end
 300                 return self._connections
 301         end
 302
 303         -- Public methods
 304         function interface_mt:write(data)
 305                 if self.nowriting then return nil, "locked" end
 306                 --vdebug( "try to send data to client, id/data:", self.id, data )
 307                 data = tostring( data )
 308                 local len = #data
 309                 local total = len + self.writebufferlen
 310                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
 311                         local err = "send buffer exceeded"
 312                         debug( "error:", err )  -- to much, check your app
 313                         return nil, err
 314                 end
 315                 t_insert(self.writebuffer, data) -- new buffer
 316                 self.writebufferlen = total
 317                 if not self.eventwrite then  -- register new write event
 318                         --vdebug( "register new write event" )
 319                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
 320                 end
 321                 return true
 322         end
 323         function interface_mt:close()
 324                 if self.nointerface then return nil, "locked"; end
 325                 debug( "try to close client connection with id:", self.id )
 326                 if self.type == "client" then
 327                         self.fatalerror = "client to close"
 328                         if self.eventwrite then -- wait for incomplete write request
 329                                 self:_lock( true, true, false )
 330                                 debug "closing delayed until writebuffer is empty"
 331                                 return nil, "writebuffer not empty, waiting"
 332                         else -- close now
 333                                 self:_lock( true, true, true )
 334                                 self:_close()
 335                                 return true
 336                         end
 337                 else
 338                         debug( "try to close server with id:", tostring(self.id))
 339                         self.fatalerror = "server to close"
 340                         self:_lock( true )
 341                         self:_close( 0 )
 342                         return true
 343                 end
 344         end
 345
 346         function interface_mt:socket()
 347                 return self.conn
 348         end
 349
 350         function interface_mt:server()
 351                 return self._server or self;
 352         end
 353
 354         function interface_mt:port()
 355                 return self._port
 356         end
 357
 358         function interface_mt:serverport()
 359                 return self._serverport
 360         end
 361
 362         function interface_mt:ip()
 363                 return self._ip
 364         end
 365
 366         function interface_mt:ssl()
 367                 return self._usingssl
 368         end
 369
 370         function interface_mt:type()
 371                 return self._type or "client"
 372         end
 373
 374         function interface_mt:connections()
 375                 return self._connections
 376         end
 377
 378         function interface_mt:address()
 379                 return self.addr
 380         end
 381
 382         function interface_mt:set_sslctx(sslctx)
 383                 self._sslctx = sslctx;
 384                 if sslctx then
 385                         self.starttls = nil; -- use starttls() of interface_mt
 386                 else
 387                         self.starttls = false; -- prevent starttls()
 388                 end
 389         end
 390
 391         function interface_mt:set_mode(pattern)
 392                 if pattern then
 393                         self._pattern = pattern;
 394                 end
 395                 return self._pattern;
 396         end
 397
 398         function interface_mt:set_send(new_send)
 399                 -- No-op, we always use the underlying connection's send
 400         end
 401
 402         function interface_mt:starttls(sslctx, call_onconnect)
 403                 debug( "try to start ssl at client id:", self.id )
 404                 local err
 405                 self._sslctx = sslctx;
 406                 if self._usingssl then  -- startssl was already called
 407                         err = "ssl already active"
 408                 end
 409                 if err then
 410                         debug( "error:", err )
 411                         return nil, err
 412                 end
 413                 self._usingssl = true
 414                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
 415                         self.startsslcallback = nil
 416                         self:_start_ssl(call_onconnect);
 417                         self.eventstarthandshake = nil
 418                         return -1
 419                 end
 420                 if not self.eventwrite then
 421                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
 422                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
 423                 else  -- wait until writebuffer is empty
 424                         self:_lock( true, true, false )
 425                         debug "ssl session delayed until writebuffer is empty..."
 426                 end
 427                 self.starttls = false;
 428                 return true
 429         end
 430
 431         function interface_mt:setoption(option, value)
 432                 if self.conn.setoption then
 433                         return self.conn:setoption(option, value);
 434                 end
 435                 return false, "setoption not implemented";
 436         end
 437
 438         function interface_mt:setlistener(listener)
 439                 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout, self.onstatus
 440                         = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout, listener.onstatus;
 441         end
 442
 443         -- Stub handlers
 444         function interface_mt:onconnect()
 445         end
 446         function interface_mt:onincoming()
 447         end
 448         function interface_mt:ondisconnect()
 449         end
 450         function interface_mt:ontimeout()
 451         end
 452         function interface_mt:ondrain()
 453         end
 454         function interface_mt:onstatus()
 455         end
 456 end
 457
 458 -- End of client interface methods
 459
 460 local handleclient;
 461 do
 462         local string_sub = string.sub  -- caching table lookups
 463         local string_len = string.len
 464         local addevent = base.addevent
 465         local socket_gettime = socket.gettime
 466         function handleclient( client, ip, port, server, pattern, listener, sslctx )  -- creates an client interface
 467                 --vdebug("creating client interfacce...")
 468                 local interface = {
 469                         type = "client";
 470                         conn = client;
 471                         currenttime = socket_gettime( );  -- safe the origin
 472                         writebuffer = {};  -- writebuffer
 473                         writebufferlen = 0;  -- length of writebuffer
 474                         send = client.send;  -- caching table lookups
 475                         receive = client.receive;
 476                         onconnect = listener.onconnect;  -- will be called when client disconnects
 477                         ondisconnect = listener.ondisconnect;  -- will be called when client disconnects
 478                         onincoming = listener.onincoming;  -- will be called when client sends data
 479                         ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
 480                         onstatus = listener.onstatus; -- called for status changes (e.g. of SSL/TLS)
 481                         eventread = false, eventwrite = false, eventclose = false,
 482                         eventhandshake = false, eventstarthandshake = false;  -- event handler
 483                         eventconnect = false, eventsession = false;  -- more event handler...
 484                         eventwritetimeout = false;  -- even more event handler...
 485                         eventreadtimeout = false;
 486                         fatalerror = false;  -- error message
 487                         writecallback = false;  -- will be called on write events
 488                         readcallback = false;  -- will be called on read events
 489                         nointerface = true;  -- lock/unlock parameter of this interface
 490                         noreading = false, nowriting = false;  -- locks of the read/writecallback
 491                         startsslcallback = false;  -- starting handshake callback
 492                         position = false;  -- position of client in interfacelist
 493
 494                         -- Properties
 495                         _ip = ip, _port = port, _server = server, _pattern = pattern,
 496                         _serverport = (server and server:port() or nil),
 497                         _sslctx = sslctx; -- parameters
 498                         _usingssl = false;  -- client is using ssl;
 499                 }
 500                 if not ssl then interface.starttls = false; end
 501                 interface.id = tostring(interface):match("%x+$");
 502                 interface.writecallback = function( event )  -- called on write events
 503                         --vdebug( "new client write event, id/ip/port:", interface, ip, port )
 504                         if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then  -- leave this event
 505                                 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
 506                                 interface.eventwrite = false
 507                                 return -1
 508                         end
 509                         if EV_TIMEOUT == event then  -- took too long to write some data to socket -> disconnect
 510                                 interface.fatalerror = "timeout during writing"
 511                                 debug( "writing failed:", interface.fatalerror )
 512                                 interface:_close()
 513                                 interface.eventwrite = false
 514                                 return -1
 515                         else  -- can write :)
 516                                 if interface._usingssl then  -- handle luasec
 517                                         if interface.eventreadtimeout then  -- we have to read first
 518                                                 local ret = interface.readcallback( )  -- call readcallback
 519                                                 --vdebug( "tried to read in writecallback, result:", ret )
 520                                         end
 521                                         if interface.eventwritetimeout then  -- luasec only
 522                                                 interface.eventwritetimeout:close( )  -- first we have to close timeout event which where regged after a wantread error
 523                                                 interface.eventwritetimeout = false
 524                                         end
 525                                 end
 526                                 interface.writebuffer = { t_concat(interface.writebuffer) }
 527                                 local succ, err, byte = interface.conn:send( interface.writebuffer[1], 1, interface.writebufferlen )
 528                                 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
 529                                 if succ then  -- writing succesful
 530                                         interface.writebuffer[1] = nil
 531                                         interface.writebufferlen = 0
 532                                         interface:ondrain();
 533                                         if interface.fatalerror then
 534                                                 debug "closing client after writing"
 535                                                 interface:_close()  -- close interface if needed
 536                                         elseif interface.startsslcallback then  -- start ssl connection if needed
 537                                                 debug "starting ssl handshake after writing"
 538                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
 539                                         elseif interface.eventreadtimeout then
 540                                                 return EV_WRITE, EV_TIMEOUT
 541                                         end
 542                                         interface.eventwrite = nil
 543                                         return -1
 544                                 elseif byte and (err == "timeout" or err == "wantwrite") then  -- want write again
 545                                         --vdebug( "writebuffer is not empty:", err )
 546                                         interface.writebuffer[1] = string_sub( interface.writebuffer[1], byte + 1, interface.writebufferlen )  -- new buffer
 547                                         interface.writebufferlen = interface.writebufferlen - byte
 548                                         if "wantread" == err then  -- happens only with luasec
 549                                                 local callback = function( )
 550                                                         interface:_close()
 551                                                         interface.eventwritetimeout = nil
 552                                                         return -1;
 553                                                 end
 554                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
 555                                                 debug( "wantread during write attempt, reg it in readcallback but dont know what really happens next..." )
 556                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
 557                                                 return -1
 558                                         end
 559                                         return EV_WRITE, cfg.WRITE_TIMEOUT
 560                                 else  -- connection was closed during writing or fatal error
 561                                         interface.fatalerror = err or "fatal error"
 562                                         debug( "connection failed in write event:", interface.fatalerror )
 563                                         interface:_close()
 564                                         interface.eventwrite = nil
 565                                         return -1
 566                                 end
 567                         end
 568                 end
 569
 570                 interface.readcallback = function( event )  -- called on read events
 571                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
 572                         if interface.noreading or interface.fatalerror then  -- leave this event
 573                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
 574                                 interface.eventread = nil
 575                                 return -1
 576                         end
 577                         if EV_TIMEOUT == event then  -- took too long to get some data from client -> disconnect
 578                                 interface.fatalerror = "timeout during receiving"
 579                                 debug( "connection failed:", interface.fatalerror )
 580                                 interface:_close()
 581                                 interface.eventread = nil
 582                                 return -1
 583                         else -- can read
 584                                 if interface._usingssl then  -- handle luasec
 585                                         if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
 586                                                 local ret = interface.writecallback( )  -- call it
 587                                                 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
 588                                         end
 589                                         if interface.eventreadtimeout then
 590                                                 interface.eventreadtimeout:close( )
 591                                                 interface.eventreadtimeout = nil
 592                                         end
 593                                 end
 594                                 local buffer, err, part = interface.conn:receive( interface._pattern )  -- receive buffer with "pattern"
 595                                 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
 596                                 buffer = buffer or part
 597                                 if buffer and #buffer > cfg.MAX_READ_LENGTH then  -- check buffer length
 598                                         interface.fatalerror = "receive buffer exceeded"
 599                                         debug( "fatal error:", interface.fatalerror )
 600                                         interface:_close()
 601                                         interface.eventread = nil
 602                                         return -1
 603                                 end
 604                                 if err and ( err ~= "timeout" and err ~= "wantread" ) then
 605                                         if "wantwrite" == err then -- need to read on write event
 606                                                 if not interface.eventwrite then  -- register new write event if needed
 607                                                         interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
 608                                                 end
 609                                                 interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
 610                                                         function( )
 611                                                                 interface:_close()
 612                                                         end, cfg.READ_TIMEOUT
 613                                                 )
 614                                                 debug( "wantwrite during read attempt, reg it in writecallback but dont know what really happens next..." )
 615                                                 -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
 616                                         else  -- connection was closed or fatal error
 617                                                 interface.fatalerror = err
 618                                                 debug( "connection failed in read event:", interface.fatalerror )
 619                                                 interface:_close()
 620                                                 interface.eventread = nil
 621                                                 return -1
 622                                         end
 623                                 else
 624                                         interface.onincoming( interface, buffer, err )  -- send new data to listener
 625                                 end
 626                                 if interface.noreading then
 627                                         interface.eventread = nil;
 628                                         return -1;
 629                                 end
 630                                 return EV_READ, cfg.READ_TIMEOUT
 631                         end
 632                 end
 633
 634                 client:settimeout( 0 )  -- set non blocking
 635                 setmetatable(interface, interface_mt)
 636                 interfacelist( "add", interface )  -- add to interfacelist
 637                 return interface
 638         end
 639 end
 640
 641 local handleserver
 642 do
 643         function handleserver( server, addr, port, pattern, listener, sslctx )  -- creates an server interface
 644                 debug "creating server interface..."
 645                 local interface = {
 646                         _connections = 0;
 647
 648                         conn = server;
 649                         onconnect = listener.onconnect;  -- will be called when new client connected
 650                         eventread = false;  -- read event handler
 651                         eventclose = false; -- close event handler
 652                         readcallback = false; -- read event callback
 653                         fatalerror = false; -- error message
 654                         nointerface = true;  -- lock/unlock parameter
 655
 656                         _ip = addr, _port = port, _pattern = pattern,
 657                         _sslctx = sslctx;
 658                 }
 659                 interface.id = tostring(interface):match("%x+$");
 660                 interface.readcallback = function( event )  -- server handler, called on incoming connections
 661                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
 662                         if interface.fatalerror then
 663                                 --vdebug( "leaving this event because:", self.fatalerror )
 664                                 interface.eventread = nil
 665                                 return -1
 666                         end
 667                         local delay = cfg.ACCEPT_DELAY
 668                         if EV_TIMEOUT == event then
 669                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
 670                                         debug( "to many connections, seconds to wait for next accept:", delay )
 671                                         return EV_TIMEOUT, delay  -- timeout...
 672                                 else
 673                                         return EV_READ  -- accept again
 674                                 end
 675                         end
 676                         --vdebug("max connection check ok, accepting...")
 677                         local client, err = server:accept()    -- try to accept; TODO: check err
 678                         while client do
 679                                 if interface._connections >= cfg.MAX_CONNECTIONS then
 680                                         client:close( )  -- refuse connection
 681                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
 682                                         return EV_TIMEOUT, delay  -- delay for next accept attempt
 683                                 end
 684                                 local client_ip, client_port = client:getpeername( )
 685                                 interface._connections = interface._connections + 1  -- increase connection count
 686                                 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, sslctx )
 687                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
 688                                 if ssl and sslctx then
 689                                         clientinterface:starttls(sslctx, true)
 690                                 else
 691                                         clientinterface:_start_session( true )
 692                                 end
 693                                 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
 694
 695                                 client, err = server:accept()    -- try to accept again
 696                         end
 697                         return EV_READ
 698                 end
 699
 700                 server:settimeout( 0 )
 701                 setmetatable(interface, interface_mt)
 702                 interfacelist( "add", interface )
 703                 interface:_start_session()
 704                 return interface
 705         end
 706 end
 707
 708 local addserver = ( function( )
 709         return function( addr, port, listener, pattern, sslcfg, startssl )  -- TODO: check arguments
 710                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
 711                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
 712                 if not server then
 713                         debug( "creating server socket on "..addr.." port "..port.." failed:", err )
 714                         return nil, err
 715                 end
 716                 local sslctx
 717                 if sslcfg then
 718                         if not ssl then
 719                                 debug "fatal error: luasec not found"
 720                                 return nil, "luasec not found"
 721                         end
 722                         sslctx, err = sslcfg
 723                         if err then
 724                                 debug( "error while creating new ssl context for server socket:", err )
 725                                 return nil, err
 726                         end
 727                 end
 728                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
 729                 debug( "new server created with id:", tostring(interface))
 730                 return interface
 731         end
 732 end )( )
 733
 734 local addclient, wrapclient
 735 do
 736         function wrapclient( client, ip, port, listeners, pattern, sslctx )
 737                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
 738                 interface:_start_connection(sslctx)
 739                 return interface, client
 740                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 741         end
 742
 743         function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
 744                 local client, err = socket.tcp()  -- creating new socket
 745                 if not client then
 746                         debug( "cannot create socket:", err )
 747                         return nil, err
 748                 end
 749                 client:settimeout( 0 )  -- set nonblocking
 750                 if localaddr then
 751                         local res, err = client:bind( localaddr, localport, -1 )
 752                         if not res then
 753                                 debug( "cannot bind client:", err )
 754                                 return nil, err
 755                         end
 756                 end
 757                 local sslctx
 758                 if sslcfg then  -- handle ssl/new context
 759                         if not ssl then
 760                                 debug "need luasec, but not available"
 761                                 return nil, "luasec not found"
 762                         end
 763                         sslctx, err = sslcfg
 764                         if err then
 765                                 debug( "cannot create new ssl context:", err )
 766                                 return nil, err
 767                         end
 768                 end
 769                 local res, err = client:connect( addr, serverport )  -- connect
 770                 if res or ( err == "timeout" ) then
 771                         local ip, port = client:getsockname( )
 772                         local interface = wrapclient( client, ip, serverport, listener, pattern, sslctx, startssl )
 773                         interface:_start_connection( startssl )
 774                         debug( "new connection id:", interface.id )
 775                         return interface, err
 776                 else
 777                         debug( "new connection failed:", err )
 778                         return nil, err
 779                 end
 780         end
 781 end
 782
 783
 784 local loop = function( )  -- starts the event loop
 785         base:loop( )
 786         return "quitting";
 787 end
 788
 789 local newevent = ( function( )
 790         local add = base.addevent
 791         return function( ... )
 792                 return add( base, ... )
 793         end
 794 end )( )
 795
 796 local closeallservers = function( arg )
 797         for _, item in ipairs( interfacelist( ) ) do
 798                 if item.type == "server" then
 799                         item:close( arg )
 800                 end
 801         end
 802 end
 803
 804 local function setquitting(yes)
 805         if yes then
 806                  -- Quit now
 807                  closeallservers();
 808                  base:loopexit();
 809         end
 810 end
 811
 812 local function get_backend()
 813         return base:method();
 814 end
 815
 816 -- We need to hold onto the events to stop them
 817 -- being garbage-collected
 818 local signal_events = {}; -- [signal_num] -> event object
 819 local function hook_signal(signal_num, handler)
 820         local function _handler(event)
 821                 local ret = handler();
 822                 if ret ~= false then -- Continue handling this signal?
 823                         return EV_SIGNAL; -- Yes
 824                 end
 825                 return -1; -- Close this event
 826         end
 827         signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
 828         return signal_events[signal_num];
 829 end
 830
 831 local function link(sender, receiver, buffersize)
 832         local sender_locked;
 833
 834         function receiver:ondrain()
 835                 if sender_locked then
 836                         sender:resume();
 837                         sender_locked = nil;
 838                 end
 839         end
 840
 841         function sender:onincoming(data)
 842                 receiver:write(data);
 843                 if receiver.writebufferlen >= buffersize then
 844                         sender_locked = true;
 845                         sender:pause();
 846                 end
 847         end
 848 end
 849
 850 return {
 851
 852         cfg = cfg,
 853         base = base,
 854         loop = loop,
 855         link = link,
 856         event = event,
 857         event_base = base,
 858         addevent = newevent,
 859         addserver = addserver,
 860         addclient = addclient,
 861         wrapclient = wrapclient,
 862         setquitting = setquitting,
 863         closeall = closeallservers,
 864         get_backend = get_backend,
 865         hook_signal = hook_signal,
 866
 867         __NAME = SCRIPT_NAME,
 868         __DATE = LAST_MODIFIED,
 869         __AUTHOR = SCRIPT_AUTHOR,
 870         __VERSION = SCRIPT_VERSION,
 871
 872 }