net/server_event.lua

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