b9bb5129a1dcdd398a810cbc067d102f47a3dd07
[prosody.git] / 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
17 local SCRIPT_NAME           = "server_event.lua"
18 local SCRIPT_VERSION        = "0.05"
19 local SCRIPT_AUTHOR         = "blastbeat"
20 local LAST_MODIFIED         = "2009/11/20"
21
22 local cfg = {
23         MAX_CONNECTIONS       = 100000,  -- max per server connections (use "ulimit -n" on *nix)
24         MAX_HANDSHAKE_ATTEMPS = 10,  -- attemps to finish ssl handshake
25         HANDSHAKE_TIMEOUT     = 1,  -- timout in seconds per handshake attemp
26         MAX_READ_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes allowed to read from sockets
27         MAX_SEND_LENGTH       = 1024 * 1024 * 1024 * 1024,  -- max bytes size of write buffer (for writing on sockets)
28         ACCEPT_DELAY          = 10,  -- seconds to wait until the next attemp of a full server to accept
29         READ_TIMEOUT          = 60 * 30,  -- timeout in seconds for read data from socket
30         WRITE_TIMEOUT         = 30,  -- timeout in seconds for write data on socket
31         CONNECT_TIMEOUT       = 10,  -- timeout in seconds for connection attemps
32         CLEAR_DELAY           = 5,  -- seconds to wait for clearing interface list (and calling ondisconnect listeners) 
33         DEBUG                 = true,  -- show debug messages
34 }
35
36 local function use(x) return rawget(_G, x); end
37 local print = use "print"
38 local pcall = use "pcall"
39 local ipairs = use "ipairs"
40 local string = use "string"
41 local select = use "select"
42 local require = use "require"
43 local tostring = use "tostring"
44 local coroutine = use "coroutine"
45 local setmetatable = use "setmetatable"
46
47 local ssl = use "ssl"
48 local socket = use "socket"
49
50 local log = require ("util.logger").init("socket")
51
52 local function debug(...)
53         return log("debug", ("%s "):rep(select('#', ...)), ...)
54 end
55 local vdebug = debug;
56
57 local bitor = ( function( ) -- thx Rici Lake
58         local hasbit = function( x, p )
59                 return x % ( p + p ) >= p
60         end
61         return function( x, y ) 
62                 local p = 1
63                 local z = 0
64                 local limit = x > y and x or y
65                 while p <= limit do 
66                         if hasbit( x, p ) or hasbit( y, p ) then
67                                 z = z + p
68                         end
69                         p = p + p
70                 end
71                 return z
72         end
73 end )( )
74
75 local event = require "luaevent.core"
76 local base = event.new( )
77 local EV_READ = event.EV_READ
78 local EV_WRITE = event.EV_WRITE
79 local EV_TIMEOUT = event.EV_TIMEOUT
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 then  -- start ssl session
146                                                 self:_start_ssl( self.listener.onconnect )
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 < 1000 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.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 "onconnect" == arg 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 )  -- 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         function interface_mt:counter(c)
285                 if c then
286                         self._connections = self._connections + c
287                 end
288                 return self._connections
289         end
290         
291         -- Public methods
292         function interface_mt:write(data)
293                 if self.nowriting then return nil, "locked" end
294                 --vdebug( "try to send data to client, id/data:", self.id, data )
295                 data = tostring( data )
296                 local len = string_len( data )
297                 local total = len + self.writebufferlen
298                 if total > cfg.MAX_SEND_LENGTH then  -- check buffer length
299                         local err = "send buffer exceeded"
300                         debug( "error:", err )  -- to much, check your app
301                         return nil, err
302                 end 
303                 self.writebuffer = self.writebuffer .. data -- new buffer
304                 self.writebufferlen = total
305                 if not self.eventwrite then  -- register new write event
306                         --vdebug( "register new write event" )
307                         self.eventwrite = addevent( base, self.conn, EV_WRITE, self.writecallback, cfg.WRITE_TIMEOUT )
308                 end
309                 return true
310         end
311         function interface_mt:close(now)
312                 if self.nointerface then return nil, "locked"; end
313                 debug( "try to close client connection with id:", self.id )
314                 if self.type == "client" then
315                         self.fatalerror = "client to close"
316                         if ( not self.eventwrite ) or now then  -- try to close immediately
317                                 self:_lock( true, true, true )
318                                 self:_close()
319                                 return true
320                         else  -- wait for incomplete write request
321                                 self:_lock( true, true, false )
322                                 debug "closing delayed until writebuffer is empty"
323                                 return nil, "writebuffer not empty, waiting"
324                         end
325                 else
326                         debug( "try to close server with id:", self.id, "args:", now )
327                         self.fatalerror = "server to close"
328                         self:_lock( true )
329                         local count = 0
330                         for _, item in ipairs( interfacelist( ) ) do
331                                 if ( item.type ~= "server" ) and ( item._server == self ) then  -- client/server match
332                                         if item:close( now ) then  -- writebuffer was empty
333                                                 count = count + 1
334                                         end
335                                 end
336                         end
337                         local timeout = 0  -- dont wait for unfinished writebuffers of clients...
338                         if not now then
339                                 timeout = cfg.WRITE_TIMEOUT  -- ...or wait for it
340                         end
341                         self:_close( timeout )  -- add new event to remove the server interface
342                         debug( "seconds remained until server is closed:", timeout )
343                         return count  -- returns finished clients with empty writebuffer
344                 end
345         end
346         
347         function interface_mt:server()
348                 return self._server or self;
349         end
350         
351         function interface_mt:port()
352                 return self._port
353         end
354         
355         function interface_mt:ip()
356                 return self._ip
357         end
358         
359         function interface_mt:ssl()
360                 return self._usingssl
361         end
362
363         function interface_mt:type()
364                 return self._type or "client"
365         end
366         
367         function interface_mt:connections()
368                 return self._connections
369         end
370         
371         function interface_mt:address()
372                 return self.addr
373         end
374         
375         function interface_mt:set_sslctx(sslctx)
376                 self._sslctx = sslctx;
377                 if sslctx then
378                         self.starttls = nil; -- use starttls() of interface_mt
379                 else
380                         self.starttls = false; -- prevent starttls()
381                 end
382         end
383         
384         function interface_mt:set_send(new_send)
385                 -- No-op, we always use the underlying connection's send
386         end
387         
388         function interface_mt:starttls()
389                 debug( "try to start ssl at client id:", self.id )
390                 local err
391                 if not self._sslctx then  -- no ssl available
392                         err = "no ssl context available"
393                 elseif self._usingssl then  -- startssl was already called
394                         err = "ssl already active"
395                 end
396                 if err then
397                         debug( "error:", err )
398                         return nil, err      
399                 end
400                 self._usingssl = true
401                 self.startsslcallback = function( )  -- we have to start the handshake outside of a read/write event
402                         self.startsslcallback = nil
403                         self:_start_ssl();
404                         self.eventstarthandshake = nil
405                         return -1
406                 end
407                 if not self.eventwrite then
408                         self:_lock( true, true, true )  -- lock the interface, to not disturb the handshake
409                         self.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, self.startsslcallback, 0 )  -- add event to start handshake
410                 else  -- wait until writebuffer is empty
411                         self:_lock( true, true, false )
412                         debug "ssl session delayed until writebuffer is empty..."
413                 end
414                 return true
415         end
416         
417         -- Stub handlers
418         function interface_mt:onconnect()
419         end
420         function interface_mt:onincoming()
421         end
422         function interface_mt:ondisconnect()
423         end
424         function interface_mt:ontimeout()
425         end
426 end                     
427
428 -- End of client interface methods
429
430 local handleclient;
431 do
432         local string_sub = string.sub  -- caching table lookups
433         local string_len = string.len
434         local addevent = base.addevent
435         local coroutine_wrap = coroutine.wrap
436         local socket_gettime = socket.gettime
437         local coroutine_yield = coroutine.yield
438         function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
439                 --vdebug("creating client interfacce...")
440                 local interface = {
441                         type = "client";
442                         conn = client;
443                         currenttime = socket_gettime( );  -- safe the origin
444                         writebuffer = "";  -- writebuffer
445                         writebufferlen = 0;  -- length of writebuffer
446                         send = client.send;  -- caching table lookups
447                         receive = client.receive;
448                         onconnect = listener.onconnect;  -- will be called when client disconnects
449                         ondisconnect = listener.ondisconnect;  -- will be called when client disconnects
450                         onincoming = listener.onincoming;  -- will be called when client sends data
451                         ontimeout = listener.ontimeout; -- called when fatal socket timeout occurs
452                         eventread = false, eventwrite = false, eventclose = false,
453                         eventhandshake = false, eventstarthandshake = false;  -- event handler
454                         eventconnect = false, eventsession = false;  -- more event handler...
455                         eventwritetimeout = false;  -- even more event handler...
456                         eventreadtimeout = false;
457                         fatalerror = false;  -- error message
458                         writecallback = false;  -- will be called on write events
459                         readcallback = false;  -- will be called on read events
460                         nointerface = true;  -- lock/unlock parameter of this interface
461                         noreading = false, nowriting = false;  -- locks of the read/writecallback
462                         startsslcallback = false;  -- starting handshake callback
463                         position = false;  -- position of client in interfacelist
464                         
465                         -- Properties
466                         _ip = ip, _port = port, _server = server, _pattern = pattern,
467                         _sslctx = sslctx; -- parameters
468                         _usingssl = false;  -- client is using ssl;
469                 }
470                 if not sslctx then
471                         interface.starttls = false -- don't allow TLS
472                 end
473                 interface.id = tostring(interface):match("%x+$");
474                 interface.writecallback = function( event )  -- called on write events
475                         --vdebug( "new client write event, id/ip/port:", interface, ip, port )
476                         if interface.nowriting or ( interface.fatalerror and ( "client to close" ~= interface.fatalerror ) ) then  -- leave this event
477                                 --vdebug( "leaving this event because:", interface.nowriting or interface.fatalerror )
478                                 interface.eventwrite = false
479                                 return -1
480                         end
481                         if EV_TIMEOUT == event then  -- took too long to write some data to socket -> disconnect
482                                 interface.fatalerror = "timeout during writing"
483                                 debug( "writing failed:", interface.fatalerror ) 
484                                 interface:_close()
485                                 interface.eventwrite = false
486                                 return -1
487                         else  -- can write :)
488                                 if interface._usingssl then  -- handle luasec
489                                         if interface.eventreadtimeout then  -- we have to read first
490                                                 local ret = interface.readcallback( )  -- call readcallback
491                                                 --vdebug( "tried to read in writecallback, result:", ret )
492                                         end
493                                         if interface.eventwritetimeout then  -- luasec only
494                                                 interface.eventwritetimeout:close( )  -- first we have to close timeout event which where regged after a wantread error
495                                                 interface.eventwritetimeout = false
496                                         end
497                                 end
498                                 local succ, err, byte = interface.conn:send( interface.writebuffer, 1, interface.writebufferlen )
499                                 --vdebug( "write data:", interface.writebuffer, "error:", err, "part:", byte )
500                                 if succ then  -- writing succesful
501                                         interface.writebuffer = ""
502                                         interface.writebufferlen = 0
503                                         if interface.fatalerror then
504                                                 debug "closing client after writing"
505                                                 interface:_close()  -- close interface if needed
506                                         elseif interface.startsslcallback then  -- start ssl connection if needed
507                                                 debug "starting ssl handshake after writing"
508                                                 interface.eventstarthandshake = addevent( base, nil, EV_TIMEOUT, interface.startsslcallback, 0 )
509                                         elseif interface.eventreadtimeout then
510                                                 return EV_WRITE, EV_TIMEOUT
511                                         end
512                                         interface.eventwrite = nil
513                                         return -1
514                                 elseif byte then  -- want write again
515                                         --vdebug( "writebuffer is not empty:", err )
516                                         interface.writebuffer = string_sub( interface.writebuffer, byte + 1, interface.writebufferlen )  -- new buffer
517                                         interface.writebufferlen = interface.writebufferlen - byte            
518                                         if "wantread" == err then  -- happens only with luasec
519                                                 local callback = function( )
520                                                         interface:_close()
521                                                         interface.eventwritetimeout = nil
522                                                         return evreturn, evtimeout
523                                                 end
524                                                 interface.eventwritetimeout = addevent( base, nil, EV_TIMEOUT, callback, cfg.WRITE_TIMEOUT )  -- reg a new timeout event
525                                                 debug( "wantread during write attemp, reg it in readcallback but dont know what really happens next..." )
526                                                 -- hopefully this works with luasec; its simply not possible to use 2 different write events on a socket in luaevent
527                                                 return -1
528                                         end
529                                         return EV_WRITE, cfg.WRITE_TIMEOUT 
530                                 else  -- connection was closed during writing or fatal error
531                                         interface.fatalerror = err or "fatal error"
532                                         debug( "connection failed in write event:", interface.fatalerror ) 
533                                         interface:_close()
534                                         interface.eventwrite = nil
535                                         return -1
536                                 end
537                         end
538                 end
539                 
540                 interface.readcallback = function( event )  -- called on read events
541                         --vdebug( "new client read event, id/ip/port:", tostring(interface.id), tostring(ip), tostring(port) )
542                         if interface.noreading or interface.fatalerror then  -- leave this event
543                                 --vdebug( "leaving this event because:", tostring(interface.noreading or interface.fatalerror) )
544                                 interface.eventread = nil
545                                 return -1
546                         end
547                         if EV_TIMEOUT == event then  -- took too long to get some data from client -> disconnect
548                                 interface.fatalerror = "timeout during receiving"
549                                 debug( "connection failed:", interface.fatalerror ) 
550                                 interface:_close()
551                                 interface.eventread = nil
552                                 return -1
553                         else -- can read
554                                 if interface._usingssl then  -- handle luasec
555                                         if interface.eventwritetimeout then  -- ok, in the past writecallback was regged
556                                                 local ret = interface.writecallback( )  -- call it
557                                                 --vdebug( "tried to write in readcallback, result:", tostring(ret) )
558                                         end
559                                         if interface.eventreadtimeout then
560                                                 interface.eventreadtimeout:close( )
561                                                 interface.eventreadtimeout = nil
562                                         end
563                                 end
564                                 local buffer, err, part = interface.conn:receive( pattern )  -- receive buffer with "pattern"
565                                 --vdebug( "read data:", tostring(buffer), "error:", tostring(err), "part:", tostring(part) )        
566                                 buffer = buffer or part or ""
567                                 local len = string_len( buffer )
568                                 if len > cfg.MAX_READ_LENGTH then  -- check buffer length
569                                         interface.fatalerror = "receive buffer exceeded"
570                                         debug( "fatal error:", interface.fatalerror )
571                                         interface:_close()
572                                         interface.eventread = nil
573                                         return -1
574                                 end
575                                 interface.onincoming( interface, buffer, err )  -- send new data to listener
576                                 if err and ( err ~= "timeout" and err ~= "wantread" ) then
577                                         if "wantwrite" == err then -- need to read on write event
578                                                 if not interface.eventwrite then  -- register new write event if needed
579                                                         interface.eventwrite = addevent( base, interface.conn, EV_WRITE, interface.writecallback, cfg.WRITE_TIMEOUT )
580                                                 end
581                                                 interface.eventreadtimeout = addevent( base, nil, EV_TIMEOUT,
582                                                         function( )
583                                                                 interface:_close()
584                                                         end, cfg.READ_TIMEOUT
585                                                 )             
586                                                 debug( "wantwrite during read attemp, reg it in writecallback but dont know what really happens next..." )
587                                                 -- to be honest i dont know what happens next, if it is allowed to first read, the write etc...
588                                         else  -- connection was closed or fatal error            
589                                                 interface.fatalerror = err
590                                                 debug( "connection failed in read event:", interface.fatalerror ) 
591                                                 interface:_close()
592                                                 interface.eventread = nil
593                                                 return -1
594                                         end
595                                 end
596                                 return EV_READ, cfg.READ_TIMEOUT
597                         end
598                 end
599
600                 client:settimeout( 0 )  -- set non blocking
601                 setmetatable(interface, interface_mt)
602                 interfacelist( "add", interface )  -- add to interfacelist
603                 return interface
604         end
605 end
606
607 local handleserver
608 do
609         function handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- creates an server interface
610                 debug "creating server interface..."
611                 local interface = {
612                         _connections = 0;
613                         
614                         conn = server;
615                         onconnect = listener.onconnect;  -- will be called when new client connected
616                         eventread = false;  -- read event handler
617                         eventclose = false; -- close event handler
618                         readcallback = false; -- read event callback
619                         fatalerror = false; -- error message
620                         nointerface = true;  -- lock/unlock parameter
621                 }
622                 interface.id = tostring(interface):match("%x+$");
623                 interface.readcallback = function( event )  -- server handler, called on incoming connections
624                         --vdebug( "server can accept, id/addr/port:", interface, addr, port )
625                         if interface.fatalerror then
626                                 --vdebug( "leaving this event because:", self.fatalerror )
627                                 interface.eventread = nil
628                                 return -1
629                         end
630                         local delay = cfg.ACCEPT_DELAY
631                         if EV_TIMEOUT == event then
632                                 if interface._connections >= cfg.MAX_CONNECTIONS then  -- check connection count
633                                         debug( "to many connections, seconds to wait for next accept:", delay )
634                                         return EV_TIMEOUT, delay  -- timeout...
635                                 else
636                                         return EV_READ  -- accept again
637                                 end
638                         end
639                         --vdebug("max connection check ok, accepting...")
640                         local client, err = server:accept()    -- try to accept; TODO: check err
641                         while client do
642                                 if interface._connections >= cfg.MAX_CONNECTIONS then
643                                         client:close( )  -- refuse connection
644                                         debug( "maximal connections reached, refuse client connection; accept delay:", delay )
645                                         return EV_TIMEOUT, delay  -- delay for next accept attemp
646                                 end
647                                 local ip, port = client:getpeername( )
648                                 interface._connections = interface._connections + 1  -- increase connection count
649                                 local clientinterface = handleclient( client, ip, port, interface, pattern, listener, nil, sslctx )
650                                 --vdebug( "client id:", clientinterface, "startssl:", startssl )
651                                 if startssl then
652                                         clientinterface:_start_ssl( clientinterface.onconnect )
653                                 else
654                                         clientinterface:_start_session( clientinterface.onconnect )
655                                 end
656                                 debug( "accepted incoming client connection from:", ip, port )
657                                 client, err = server:accept()    -- try to accept again
658                         end
659                         return EV_READ
660                 end
661                 
662                 server:settimeout( 0 )
663                 setmetatable(interface, interface_mt)
664                 interfacelist( "add", interface )
665                 interface:_start_session()
666                 return interface
667         end
668 end
669
670 local addserver = ( function( )
671         return function( addr, port, listener, pattern, sslcfg, startssl )  -- TODO: check arguments
672                 --vdebug( "creating new tcp server with following parameters:", addr or "nil", port or "nil", sslcfg or "nil", startssl or "nil")
673                 local server, err = socket.bind( addr, port, cfg.ACCEPT_QUEUE )  -- create server socket
674                 if not server then
675                         debug( "creating server socket failed because:", err )
676                         return nil, err
677                 end
678                 local sslctx
679                 if sslcfg then
680                         if not ssl then
681                                 debug "fatal error: luasec not found"
682                                 return nil, "luasec not found"
683                         end
684                         sslctx, err = ssl.newcontext( sslcfg )
685                         if err then
686                                 debug( "error while creating new ssl context for server socket:", err )
687                                 return nil, err
688                         end
689                 end      
690                 local interface = handleserver( server, addr, port, pattern, listener, sslctx, startssl )  -- new server handler
691                 debug( "new server created with id:", tostring(interface))
692                 return interface
693         end
694 end )( )
695
696 local addclient, wrapclient
697 do
698         function wrapclient( client, ip, port, listeners, pattern, sslctx, startssl )
699                 local interface = handleclient( client, ip, port, nil, pattern, listeners, sslctx )
700                 interface:_start_session()
701                 return interface
702                 --function handleclient( client, ip, port, server, pattern, listener, _, sslctx )  -- creates an client interface
703         end
704         
705         function addclient( addr, serverport, listener, pattern, localaddr, localport, sslcfg, startssl )
706                 local client, err = socket.tcp()  -- creating new socket
707                 if not client then
708                         debug( "cannot create socket:", err ) 
709                         return nil, err
710                 end
711                 client:settimeout( 0 )  -- set nonblocking
712                 if localaddr then
713                         local res, err = client:bind( localaddr, localport, -1 )
714                         if not res then
715                                 debug( "cannot bind client:", err )
716                                 return nil, err
717                         end
718                 end
719                 local sslctx
720                 if sslcfg then  -- handle ssl/new context
721                         if not ssl then
722                                 debug "need luasec, but not available" 
723                                 return nil, "luasec not found"
724                         end
725                         sslctx, err = ssl.newcontext( sslcfg )
726                         if err then
727                                 debug( "cannot create new ssl context:", err )
728                                 return nil, err
729                         end
730                 end
731                 local res, err = client:connect( addr, serverport )  -- connect
732                 if res or ( err == "timeout" ) then
733                         local ip, port = client:getsockname( )
734                         local server = function( )
735                                 return nil, "this is a dummy server interface"
736                         end
737                         local interface = wrapclient( client, ip, serverport, listeners, pattern, sslctx, startssl )
738                         interface:_start_connection( startssl )
739                         debug( "new connection id:", interface.id )
740                         return interface, err
741                 else
742                         debug( "new connection failed:", err )
743                         return nil, err
744                 end
745         end
746 end
747
748
749 local loop = function( )  -- starts the event loop
750         base:loop( )
751         return "quitting";
752 end
753
754 local newevent = ( function( )
755         local add = base.addevent
756         return function( ... )
757                 return add( base, ... )
758         end
759 end )( )
760
761 local closeallservers = function( arg )
762         for _, item in ipairs( interfacelist( ) ) do
763                 if item.type == "server" then
764                         item:close( arg )
765                 end
766         end
767 end
768
769 local function setquitting(yes)
770         if yes then
771                  -- Quit now
772                  closeallservers();
773                  base:loopexit();
774         end
775 end
776
777 return {
778
779         cfg = cfg,
780         base = base,
781         loop = loop,
782         event = event,
783         event_base = base,
784         addevent = newevent,
785         addserver = addserver,
786         addclient = addclient,
787         wrapclient = wrapclient,
788         setquitting = setquitting,
789         closeall = closeallservers,
790
791         __NAME = SCRIPT_NAME,
792         __DATE = LAST_MODIFIED,
793         __AUTHOR = SCRIPT_AUTHOR,
794         __VERSION = SCRIPT_VERSION,
795
796 }