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_ATTEMPTS= 1000,  -- attempts to finish ssl handshake
  24         HANDSHAKE_TIMEOUT     = 60,  -- timeout 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  -- timeout 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(nil, true)
 147                                         else  -- normal connection
 148                                                 self:_start_session(true)
 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(call_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                                 if call_onconnect then
 165                                         self:onconnect()
 166                                 end
 167                                 self.eventsession = nil
 168                                 return -1
 169                         end
 170                         self.eventsession = addevent( base, nil, EV_TIMEOUT, callback, 0 )
 171                 else
 172                         self:_lock( false )
 173                         --vdebug( "start listening on server socket with id:", self.id )
 174                         self.eventread = addevent( base, self.conn, EV_READ, self.readcallback )  -- register callback
 175                 end
 176                 return true
 177         end
 178         function interface_mt:_start_ssl(call_onconnect) -- old socket will be destroyed, therefore we have to close read/write events first
 179                         --vdebug( "starting ssl session with client id:", self.id )
 180                         local _
 181                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 182                         _ = self.eventwrite and self.eventwrite:close( )
 183                         self.eventread, self.eventwrite = nil, nil
 184                         local err
 185                         self.conn, err = ssl.wrap( self.conn, self._sslctx )
 186                         if err then
 187                                 self.fatalerror = err
 188                                 self.conn = nil  -- cannot be used anymore
 189                                 if call_onconnect then
 190                                         self.ondisconnect = nil  -- dont call this when client isnt really connected
 191                                 end
 192                                 self:_close()
 193                                 debug( "fatal error while ssl wrapping:", err )
 194                                 return false
 195                         end
 196                         self.conn:settimeout( 0 )  -- set non blocking
 197                         local handshakecallback = coroutine_wrap(
 198                                 function( event )
 199                                         local _, err
 200                                         local attempt = 0
 201                                         local maxattempt = cfg.MAX_HANDSHAKE_ATTEMPTS
 202                                         while attempt < maxattempt do  -- no endless loop
 203                                                 attempt = attempt + 1
 204                                                 debug( "ssl handshake of client with id:"..tostring(self)..", attempt:"..attempt )
 205                                                 if attempt > maxattempt then
 206                                                         self.fatalerror = "max handshake attempts exceeded"
 207                                                 elseif EV_TIMEOUT == event then
 208                                                         self.fatalerror = "timeout during handshake"
 209                                                 else
 210                                                         _, err = self.conn:dohandshake( )
 211                                                         if not err then
 212                                                                 self:_lock( false, false, false )  -- unlock the interface; sending, closing etc allowed
 213                                                                 self.send = self.conn.send  -- caching table lookups with new client object
 214                                                                 self.receive = self.conn.receive
 215                                                                 local onsomething
 216                                                                 if not call_onconnect then  -- trigger listener
 217                                                                         self:onstatus("ssl-handshake-complete");
 218                                                                 end
 219                                                                 self:_start_session( call_onconnect )
 220                                                                 debug( "ssl handshake done" )
 221                                                                 self.eventhandshake = nil
 222                                                                 return -1
 223                                                         end
 224                                                         debug( "error during ssl handshake:", err )
 225                                                         if err == "wantwrite" then
 226                                                                 event = EV_WRITE
 227                                                         elseif err == "wantread" then
 228                                                                 event = EV_READ
 229                                                         else
 230                                                                 self.fatalerror = err
 231                                                         end
 232                                                 end
 233                                                 if self.fatalerror then
 234                                                         if call_onconnect then
 235                                                                 self.ondisconnect = nil  -- dont call this when client isnt really connected
 236                                                         end
 237                                                         self:_close()
 238                                                         debug( "handshake failed because:", self.fatalerror )
 239                                                         self.eventhandshake = nil
 240                                                         return -1
 241                                                 end
 242                                                 event = coroutine_yield( event, cfg.HANDSHAKE_TIMEOUT )  -- yield this monster...
 243                                         end
 244                                 end
 245                         )
 246                         debug "starting handshake..."
 247                         self:_lock( false, true, true )  -- unlock read/write events, but keep interface locked
 248                         self.eventhandshake = addevent( base, self.conn, EV_READWRITE, handshakecallback, cfg.HANDSHAKE_TIMEOUT )
 249                         return true
 250         end
 251         function interface_mt:_destroy()  -- close this interface + events and call last listener
 252                         debug( "closing client with id:", self.id )
 253                         self:_lock( true, true, true )  -- first of all, lock the interface to avoid further actions
 254                         local _
 255                         _ = self.eventread and self.eventread:close( )  -- close events; this must be called outside of the event callbacks!
 256                         if self.type == "client" then
 257                                 _ = self.eventwrite and self.eventwrite:close( )
 258                                 _ = self.eventhandshake and self.eventhandshake:close( )
 259                                 _ = self.eventstarthandshake and self.eventstarthandshake:close( )
 260                                 _ = self.eventconnect and self.eventconnect:close( )
 261                                 _ = self.eventsession and self.eventsession:close( )
 262                                 _ = self.eventwritetimeout and self.eventwritetimeout:close( )
 263                                 _ = self.eventreadtimeout and self.eventreadtimeout:close( )
 264                                 _ = 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)
 265                                 _ = self.conn and self.conn:close( ) -- close connection, must also be called outside of any socket registered events!
 266                                 _ = self._server and self._server:counter(-1);
 267                                 self.eventread, self.eventwrite = nil, nil
 268                                 self.eventstarthandshake, self.eventhandshake, self.eventclose = nil, nil, nil
 269                                 self.readcallback, self.writecallback = nil, nil
 270                         else
 271                                 self.conn:close( )
 272                                 self.eventread, self.eventclose = nil, nil
 273                                 self.interface, self.readcallback = nil, nil
 274                         end
 275                         interfacelist( "delete", self )
 276                         return true
 277         end
 278
 279         function interface_mt:_lock(nointerface, noreading, nowriting)  -- lock or unlock this interface or events
 280                         self.nointerface, self.noreading, self.nowriting = nointerface, noreading, nowriting
 281                         return nointerface, noreading, nowriting
 282         end
 283
 284         --TODO: Deprecate
 285         function interface_mt:lock_read(switch)
 286                 if switch then
 287                         return self:pause();
 288                 else
 289                         return self:resume();
 290                 end
 291         end
 292
 293         function interface_mt:pause()
 294                 return self:_lock(self.nointerface, true, self.nowriting);
 295         end
 296
 297         function interface_mt:resume()
 298                 return self:_lock(self.nointerface, false, self.nowriting);
 299         end
 300
 301         function interface_mt:counter(c)
 302                 if c then
 303                         self._connections = self._connections + c
 304                 end
 305                 return self._connections
 306         end
 307
 308         -- Public methods
 309         function interface_mt:write(data)
 310                 if self.nowriting then return nil, "locked" end
 311                 --vdebug( "try to send data to client, id/data:", self.id, data )
 312                 data = tostring( data )
 313                 local len = string_len( data )
 314                 local total = len + self.writebufferlen
 315                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
 316                         local err = "send buffer exceeded"
 317                         debug( "error:", err )  -- to much, check your app
 318                         return nil, err
 319                 end
 320                 self.writebuffer = self.writebuffer .. data -- new buffer
 321                 self.writebufferlen = total
 322                 if not self.eventwrite then  -- register new write event
 323                         --vdebug( "register new write event" )
 324                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
 325                 end
 326                 return true
 327         end
 328         function interface_mt:close(now)
 329                 if self.nointerface then return nil, "locked"; end
 330                 debug( "try to close client connection with id:", self.id )
 331                 if self.type == "client" then
 332                         self.fatalerror = "client to close"
 333                         if ( not self.eventwrite ) or now then  -- try to close immediately
 334                                 self:_lock( true, true, true )
 335                                 self:_close()
 336                                 return true
 337                         else  -- wait for incomplete write request
 338                                 self:_lock( true, true, false )
 339                                 debug "closing delayed until writebuffer is empty"
 340                                 return nil, "writebuffer not empty, waiting"
 341                         end
 342                 else
 343                         debug( "try to close server with id:", self.id, "args:", now )
 344                         self.fatalerror = "server to close"
 345                         self:_lock( true )
 346                         local count = 0
 347                         for _, item in ipairs( interfacelist( ) ) do
 348                                 if ( item.type ~= "server" ) and ( item._server == self ) then  -- client/server match
 349                                         if item:close( now ) then  -- writebuffer was empty
 350                                                 count = count + 1
 351                                         end
 352                                 end
 353                         end
 354                         local timeout = 0  -- dont wait for unfinished writebuffers of clients...
 355                         if not now then
 356                                 timeout = cfg.WRITE_TIMEOUT  -- ...or wait for it
 357                         end
 358                         self:_close( timeout )  -- add new event to remove the server interface
 359                         debug( "seconds remained until server is closed:", timeout )
 360                         return count  -- returns finished clients with empty writebuffer
 361                 end
 362         end
 363
 364         function interface_mt:server()
 365                 return self._server or self;
 366         end
 367
 368         function interface_mt:port()
 369                 return self._port
 370         end
 371
 372         function interface_mt:serverport()
 373                 return self._serverport
 374         end
 375
 376         function interface_mt:ip()
 377                 return self._ip
 378         end
 379
 380         function interface_mt:ssl()
 381                 return self._usingssl
 382         end
 383
 384         function interface_mt:type()
 385                 return self._type or "client"
 386         end
 387
 388         function interface_mt:connections()
 389                 return self._connections
 390         end
 391
 392         function interface_mt:address()
 393                 return self.addr
 394         end
 395
 396         function interface_mt:set_sslctx(sslctx)
 397                 self._sslctx = sslctx;
 398                 if sslctx then
 399                         self.starttls = nil; -- use starttls() of interface_mt
 400                 else
 401                         self.starttls = false; -- prevent starttls()
 402                 end
 403         end
 404
 405         function interface_mt:set_mode(pattern)
 406                 if pattern then
 407                         self._pattern = pattern;
 408                 end
 409                 return self._pattern;
 410         end
 411
 412         function interface_mt:set_send(new_send)
 413                 -- No-op, we always use the underlying connection's send
 414         end
 415
 416         function interface_mt:starttls(sslctx, call_onconnect)
 417                 debug( "try to start ssl at client id:", self.id )
 418                 local err
 419                 self._sslctx = sslctx;
 420                 if self._usingssl then  -- startssl was already called
 421                         err = "ssl already active"
 422                 end
 423                 if err then
 424                         debug( "error:", err )
 425                         return nil, err
 426                 end
 427                 self._usingssl = true
 428                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
 429                         self.startsslcallback = nil
 430                         self:_start_ssl(call_onconnect);
 431                         self.eventstarthandshake = nil
 432                         return -1
 433                 end
 434                 if not self.eventwrite then
 435                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
 436                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
 437                 else  -- wait until writebuffer is empty
 438                         self:_lock( true, true, false )
 439                         debug "ssl session delayed until writebuffer is empty..."
 440                 end
 441                 self.starttls = false;
 442                 return true
 443         end
 444
 445         function interface_mt:setoption(option, value)
 446                 if self.conn.setoption then
 447                         return self.conn:setoption(option, value);
 448                 end
 449                 return false, "setoption not implemented";
 450         end
 451
 452         function interface_mt:setlistener(listener)
 453                 self.onconnect, self.ondisconnect, self.onincoming, self.ontimeout, self.onstatus
 454                         = listener.onconnect, listener.ondisconnect, listener.onincoming, listener.ontimeout, listener.onstatus;
 455         end
 456
 457         -- Stub handlers
 458         function interface_mt:onconnect()
 459                 return self:onincoming(nil);
 460         end
 461         function interface_mt:onincoming()
 462         end
 463         function interface_mt:ondisconnect()
 464         end
 465         function interface_mt:ontimeout()
 466         end
 467         function interface_mt:ondrain()
 468         end
 469         function interface_mt: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                                         interface:ondrain();
 549                                         if interface.fatalerror then
 550                                                 debug "closing client after writing"
 551                                                 interface:_close()  -- close interface if needed
 552                                         elseif interface.startsslcallback then  -- start ssl connection if needed
 553                                                 debug "starting ssl handshake after writing"
 554                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
 555                                         elseif interface.eventreadtimeout then
 556                                                 return EV_WRITE, EV_TIMEOUT
 557                                         end
 558                                         interface.eventwrite = nil
 559                                         return -1
 560                                 elseif byte and (err == "timeout" or err == "wantwrite") then  -- want write again
 561                                         --vdebug( "writebuffer is not empty:", err )
 562                                         interface.writebuffer = string_sub( interface.writebuffer, byte + 1, interface.writebufferlen )  -- new buffer
 563                                         interface.writebufferlen = interface.writebufferlen - byte
 564                                         if "wantread" == err then  -- happens only with luasec
 565                                                 local callback = function( )
 566                                                         interface:_close()
 567                                                         interface.eventwritetimeout = nil
 568                                                         return -1;
 569                                                 end
 570                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
 571                                                 debug( "wantread during write attempt, reg it in readcallback but dont know what really happens next..." )
 572                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
 573                                                 return -1
 574                                         end
 575                                         return EV_WRITE, cfg.WRITE_TIMEOUT
 576                                 else  -- connection was closed during writing or fatal error
 577                                         interface.fatalerror = err or "fatal error"
 578                                         debug( "connection failed in write event:", interface.fatalerror )
 579                                         interface:_close()
 580                                         interface.eventwrite = nil
 581                                         return -1
 582                                 end
 583                         end
 584                 end
 585
 586                 interface.readcallback = function( event )  -- called on read events
 587                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
 588                         if interface.noreading or interface.fatalerror then  -- leave this event
 589                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
 590                                 interface.eventread = nil
 591                                 return -1
 592                         end
 593                         if EV_TIMEOUT == event then  -- took too long to get some data from client -> disconnect
 594                                 interface.fatalerror = "timeout during receiving"
 595                                 debug( "connection failed:", interface.fatalerror )
 596                                 interface:_close()
 597                                 interface.eventread = nil
 598                                 return -1
 599                         else -- can read
 600                                 if interface._usingssl then  -- handle luasec
 601                                         if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
 602                                                 local ret = interface.writecallback( )  -- call it
 603                                                 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
 604                                         end
 605                                         if interface.eventreadtimeout then
 606                                                 interface.eventreadtimeout:close( )
 607                                                 interface.eventreadtimeout = nil
 608                                         end
 609                                 end
 610                                 local buffer, err, part = interface.conn:receive( interface._pattern )  -- receive buffer with "pattern"
 611                                 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )
 612                                 buffer = buffer or part or ""
 613                                 local len = string_len( buffer )
 614                                 if len > cfg.MAX_READ_LENGTH then  -- check buffer length
 615                                         interface.fatalerror = "receive buffer exceeded"
 616                                         debug( "fatal error:", interface.fatalerror )
 617                                         interface:_close()
 618                                         interface.eventread = nil
 619                                         return -1
 620                                 end
 621                                 interface.onincoming( interface, buffer, err )  -- send new data to listener
 622                                 if err and ( err ~= "timeout" and err ~= "wantread" ) then
 623                                         if "wantwrite" == err then -- need to read on write event
 624                                                 if not interface.eventwrite then  -- register new write event if needed
 625                                                         interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
 626                                                 end
 627                                                 interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
 628                                                         function( )
 629                                                                 interface:_close()
 630                                                         end, cfg.READ_TIMEOUT
 631                                                 )
 632                                                 debug( "wantwrite during read attempt, reg it in writecallback but dont know what really happens next..." )
 633                                                 -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
 634                                         else  -- connection was closed or fatal error
 635                                                 interface.fatalerror = err
 636                                                 debug( "connection failed in read event:", interface.fatalerror )
 637                                                 interface:_close()
 638                                                 interface.eventread = nil
 639                                                 return -1
 640                                         end
 641                                 end
 642                                 return EV_READ, cfg.READ_TIMEOUT
 643                         end
 644                 end
 645
 646                 client:settimeout( 0 )  -- set non blocking
 647                 setmetatable(interface, interface_mt)
 648                 interfacelist( "add", interface )  -- add to interfacelist
 649                 return interface
 650         end
 651 end
 652
 653 local handleserver
 654 do
 655         function handleserver( server, addr, port, pattern, listener, sslctx )  -- creates an server interface
 656                 debug "creating server interface..."
 657                 local interface = {
 658                         _connections = 0;
 659
 660                         conn = server;
 661                         onconnect = listener.onconnect;  -- will be called when new client connected
 662                         eventread = false;  -- read event handler
 663                         eventclose = false; -- close event handler
 664                         readcallback = false; -- read event callback
 665                         fatalerror = false; -- error message
 666                         nointerface = true;  -- lock/unlock parameter
 667
 668                         _ip = addr, _port = port, _pattern = pattern,
 669                         _sslctx = sslctx;
 670                 }
 671                 interface.id = tostring(interface):match("%x+$");
 672                 interface.readcallback = function( event )  -- server handler, called on incoming connections
 673                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
 674                         if interface.fatalerror then
 675                                 --vdebug( "leaving this event because:", self.fatalerror )
 676                                 interface.eventread = nil
 677                                 return -1
 678                         end
 679                         local delay = cfg.ACCEPT_DELAY
 680                         if EV_TIMEOUT == event then
 681                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
 682                                         debug( "to many connections, seconds to wait for next accept:", delay )
 683                                         return EV_TIMEOUT, delay  -- timeout...
 684                                 else
 685                                         return EV_READ  -- accept again
 686                                 end
 687                         end
 688                         --vdebug("max connection check ok, accepting...")
 689                         local client, err = server:accept()    -- try to accept; TODO: check err
 690                         while client do
 691                                 if interface._connections >= cfg.MAX_CONNECTIONS then
 692                                         client:close( )  -- refuse connection
 693                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
 694                                         return EV_TIMEOUT, delay  -- delay for next accept attempt
 695                                 end
 696                                 local client_ip, client_port = client:getpeername( )
 697                                 interface._connections = interface._connections + 1  -- increase connection count
 698                                 local clientinterface = handleclient( client, client_ip, client_port, interface, pattern, listener, nil, sslctx )
 699                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
 700                                 if ssl and sslctx then
 701                                         clientinterface:starttls(sslctx, true)
 702                                 else
 703                                         clientinterface:_start_session( true )
 704                                 end
 705                                 debug( "accepted incoming client connection from:", client_ip or "<unknown IP>", client_port or "<unknown port>", "to", port or "<unknown port>");
 706
 707                                 client, err = server:accept()    -- try to accept again
 708                         end
 709                         return EV_READ
 710                 end
 711
 712                 server:settimeout( 0 )
 713                 setmetatable(interface, interface_mt)
 714                 interfacelist( "add", interface )
 715                 interface:_start_session()
 716                 return interface
 717         end
 718 end
 719
 720 local addserver = ( function( )
 721         return function( addr, port, listener, pattern, sslcfg, startssl )  -- TODO: check arguments
 722                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
 723                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
 724                 if not server then
 725                         debug( "creating server socket failed because:", err )
 726                         return nil, err
 727                 end
 728                 local sslctx
 729                 if sslcfg then
 730                         if not ssl then
 731                                 debug "fatal error: luasec not found"
 732                                 return nil, "luasec not found"
 733                         end
 734                         sslctx, err = sslcfg
 735                         if err then
 736                                 debug( "error while creating new ssl context for server socket:", err )
 737                                 return nil, err
 738                         end
 739                 end
 740                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
 741                 debug( "new server created with id:", tostring(interface))
 742                 return interface
 743         end
 744 end )( )
 745
 746 local addclient, wrapclient
 747 do
 748         function wrapclient( client, ip, port, listeners, pattern, sslctx, startssl )
 749                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
 750                 interface:_start_session()
 751                 return interface, client
 752                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
 753         end
 754
 755         function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
 756                 local client, err = socket.tcp()  -- creating new socket
 757                 if not client then
 758                         debug( "cannot create socket:", err )
 759                         return nil, err
 760                 end
 761                 client:settimeout( 0 )  -- set nonblocking
 762                 if localaddr then
 763                         local res, err = client:bind( localaddr, localport, -1 )
 764                         if not res then
 765                                 debug( "cannot bind client:", err )
 766                                 return nil, err
 767                         end
 768                 end
 769                 local sslctx
 770                 if sslcfg then  -- handle ssl/new context
 771                         if not ssl then
 772                                 debug "need luasec, but not available"
 773                                 return nil, "luasec not found"
 774                         end
 775                         sslctx, err = sslcfg
 776                         if err then
 777                                 debug( "cannot create new ssl context:", err )
 778                                 return nil, err
 779                         end
 780                 end
 781                 local res, err = client:connect( addr, serverport )  -- connect
 782                 if res or ( err == "timeout" ) then
 783                         local ip, port = client:getsockname( )
 784                         local server = function( )
 785                                 return nil, "this is a dummy server interface"
 786                         end
 787                         local interface = wrapclient( client, ip, serverport, listener, pattern, sslctx, startssl )
 788                         interface:_start_connection( startssl )
 789                         debug( "new connection id:", interface.id )
 790                         return interface, err
 791                 else
 792                         debug( "new connection failed:", err )
 793                         return nil, err
 794                 end
 795         end
 796 end
 797
 798
 799 local loop = function( )  -- starts the event loop
 800         base:loop( )
 801         return "quitting";
 802 end
 803
 804 local newevent = ( function( )
 805         local add = base.addevent
 806         return function( ... )
 807                 return add( base, ... )
 808         end
 809 end )( )
 810
 811 local closeallservers = function( arg )
 812         for _, item in ipairs( interfacelist( ) ) do
 813                 if item.type == "server" then
 814                         item:close( arg )
 815                 end
 816         end
 817 end
 818
 819 local function setquitting(yes)
 820         if yes then
 821                  -- Quit now
 822                  closeallservers();
 823                  base:loopexit();
 824         end
 825 end
 826
 827 function get_backend()
 828         return base:method();
 829 end
 830
 831 -- We need to hold onto the events to stop them
 832 -- being garbage-collected
 833 local signal_events = {}; -- [signal_num] -> event object
 834 function hook_signal(signal_num, handler)
 835         local function _handler(event)
 836                 local ret = handler();
 837                 if ret ~= false then -- Continue handling this signal?
 838                         return EV_SIGNAL; -- Yes
 839                 end
 840                 return -1; -- Close this event
 841         end
 842         signal_events[signal_num] = base:addevent(signal_num, EV_SIGNAL, _handler);
 843         return signal_events[signal_num];
 844 end
 845
 846 local function link(sender, receiver, buffersize)
 847         local sender_locked;
 848
 849         function receiver:ondrain()
 850                 if sender_locked then
 851                         sender:resume();
 852                         sender_locked = nil;
 853                 end
 854         end
 855
 856         function sender:onincoming(data)
 857                 receiver:write(data);
 858                 if receiver.writebufferlen >= buffersize then
 859                         sender_locked = true;
 860                         sender:pause();
 861                 end
 862         end
 863 end
 864
 865 return {
 866
 867         cfg = cfg,
 868         base = base,
 869         loop = loop,
 870         link = link,
 871         event = event,
 872         event_base = base,
 873         addevent = newevent,
 874         addserver = addserver,
 875         addclient = addclient,
 876         wrapclient = wrapclient,
 877         setquitting = setquitting,
 878         closeall = closeallservers,
 879         get_backend = get_backend,
 880         hook_signal = hook_signal,
 881
 882         __NAME = SCRIPT_NAME,
 883         __DATE = LAST_MODIFIED,
 884         __AUTHOR = SCRIPT_AUTHOR,
 885         __VERSION = SCRIPT_VERSION,
 886
 887 }