aboutsummaryrefslogtreecommitdiffstats
path: root/net/server_epoll.lua
blob: 93a7a1a94231f1047fbb1fee5322095621b093c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
-- Prosody IM
-- Copyright (C) 2016 Kim Alvefur
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

-- server_epoll
--  Server backend based on https://luarocks.org/modules/zash/lua-epoll

local t_sort = table.sort;
local t_insert = table.insert;
local t_remove = table.remove;
local t_concat = table.concat;
local setmetatable = setmetatable;
local tostring = tostring;
local pcall = pcall;
local next = next;
local pairs = pairs;
local log = require "util.logger".init("server_epoll");
local epoll = require "epoll";
local socket = require "socket";
local luasec = require "ssl";
local gettime = require "util.time".now;
local createtable = require "util.table".create;
local _SOCKETINVALID = socket._SOCKETINVALID or -1;

assert(socket.tcp6 and socket.tcp4, "Incompatible LuaSocket version");

local _ENV = nil;

local default_config = { __index = {
	read_timeout = 900;
	write_timeout = 7;
	tcp_backlog = 128;
	accept_retry_interval = 10;
	read_retry_delay = 1e-06;
	connect_timeout = 20;
	handshake_timeout = 60;
	max_wait = 86400;
	min_wait = 1e-06;
}};
local cfg = default_config.__index;

local fds = createtable(10, 0); -- FD -> conn

-- Timer and scheduling --

local timers = {};

local function noop() end
local function closetimer(t)
	t[1] = 0;
	t[2] = noop;
end

-- Set to true when timers have changed
local resort_timers = false;

-- Add absolute timer
local function at(time, f)
	local timer = { time, f, close = closetimer };
	t_insert(timers, timer);
	resort_timers = true;
	return timer;
end

-- Add relative timer
local function addtimer(timeout, f)
	return at(gettime() + timeout, f);
end

-- Run callbacks of expired timers
-- Return time until next timeout
local function runtimers(next_delay, min_wait)
	-- Any timers at all?
	if not timers[1] then
		return next_delay;
	end

	if resort_timers then
		-- Sort earliest timers to the end
		t_sort(timers, function (a, b) return a[1] > b[1]; end);
		resort_timers = false;
	end

	-- Iterate from the end and remove completed timers
	for i = #timers, 1, -1 do
		local timer = timers[i];
		local t, f = timer[1], timer[2];
		-- Get time for every iteration to increase accuracy
		local now = gettime();
		if t > now then
			-- This timer should not fire yet
			local diff = t - now;
			if diff < next_delay then
				next_delay = diff;
			end
			break;
		end
		local new_timeout = f(now);
		if new_timeout then
			-- Schedule for 'delay' from the time actually scheduled,
			-- not from now, in order to prevent timer drift.
			timer[1] = t + new_timeout;
			resort_timers = true;
		else
			t_remove(timers, i);
		end
	end

	if resort_timers or next_delay < min_wait then
		-- Timers may be added from within a timer callback.
		-- Those would not be considered for next_delay,
		-- and we might sleep for too long, so instead
		-- we return a shorter timeout so we can
		-- properly sort all new timers.
		next_delay = min_wait;
	end

	return next_delay;
end

-- Socket handler interface

local interface = {};
local interface_mt = { __index = interface };

function interface_mt:__tostring()
	if self.sockname and self.peername then
		return ("FD %d (%s, %d, %s, %d)"):format(self:getfd(), self.peername, self.peerport, self.sockname, self.sockport);
	elseif self.sockname or self.peername then
		return ("FD %d (%s, %d)"):format(self:getfd(), self.sockname or self.peername, self.sockport or self.peerport);
	end
	return ("%s FD %d"):format(tostring(self.conn), self:getfd());
end

-- Replace the listener and tell the old one
function interface:setlistener(listeners)
	self:on("detach");
	self.listeners = listeners;
end

-- Call a listener callback
function interface:on(what, ...)
	if not self.listeners then
		log("error", "%s has no listeners", self);
		return;
	end
	local listener = self.listeners["on"..what];
	if not listener then
		-- log("debug", "Missing listener 'on%s'", what); -- uncomment for development and debugging
		return;
	end
	local ok, err = pcall(listener, self, ...);
	if not ok then
		log("error", "Error calling on%s: %s", what, err);
	end
	return err;
end

-- Return the file descriptor number
function interface:getfd()
	if self.conn then
		return self.conn:getfd();
	end
	return _SOCKETINVALID;
end

function interface:server()
	return self._server or self;
end

-- Get IP address
function interface:ip()
	return self.peername or self.sockname;
end

-- Get a port number, doesn't matter which
function interface:port()
	return self.sockport or self.peerport;
end

-- Get local port number
function interface:clientport()
	return self.sockport;
end

-- Get remote port
function interface:serverport()
	if self.sockport then
		return self.sockport;
	elseif self._server then
		self._server:port();
	end
end

-- Return underlying socket
function interface:socket()
	return self.conn;
end

function interface:set_mode(new_mode)
	self._pattern = new_mode;
end

function interface:setoption(k, v)
	-- LuaSec doesn't expose setoption :(
	if self.conn.setoption then
		self.conn:setoption(k, v);
	end
end

-- Timeout for detecting dead or idle sockets
function interface:setreadtimeout(t)
	if t == false then
		if self._readtimeout then
			self._readtimeout:close();
			self._readtimeout = nil;
		end
		return
	end
	t = t or cfg.read_timeout;
	if self._readtimeout then
		self._readtimeout[1] = gettime() + t;
		resort_timers = true;
	else
		self._readtimeout = addtimer(t, function ()
			if self:on("readtimeout") then
				return cfg.read_timeout;
			else
				self:on("disconnect", "read timeout");
				self:destroy();
			end
		end);
	end
end

-- Timeout for detecting dead sockets
function interface:setwritetimeout(t)
	if t == false then
		if self._writetimeout then
			self._writetimeout:close();
			self._writetimeout = nil;
		end
		return
	end
	t = t or cfg.write_timeout;
	if self._writetimeout then
		self._writetimeout[1] = gettime() + t;
		resort_timers = true;
	else
		self._writetimeout = addtimer(t, function ()
			self:on("disconnect", "write timeout");
			self:destroy();
		end);
	end
end

-- lua-epoll flag for currently requested poll state
function interface:flags()
	if self._wantread then
		if self._wantwrite then
			return "rw";
		end
		return "r";
	elseif self._wantwrite then
		return "w";
	end
end

-- Add or remove sockets or modify epoll flags
function interface:setflags(r, w)
	if r ~= nil then self._wantread = r; end
	if w ~= nil then self._wantwrite = w; end
	local flags = self:flags();
	local currentflags = self._flags;
	if flags == currentflags then
		return true;
	end
	local fd = self:getfd();
	if fd < 0 then
		self._wantread, self._wantwrite = nil, nil;
		return nil, "invalid fd";
	end
	local op = "mod";
	if not flags then
		op = "del";
	elseif not currentflags then
		op = "add";
	end
	local ok, err = epoll.ctl(op, fd, flags);
--	log("debug", "epoll_ctl(%q, %d, %q) -> %s" .. (err and ", %q" or ""),
--		op, fd, flags or "", tostring(ok), err);
	if not ok then return ok, err end
	if op == "add" then
		fds[fd] = self;
	elseif op == "del" then
		fds[fd] = nil;
	end
	self._flags = flags;
	return true;
end

-- Called when socket is readable
function interface:onreadable()
	local data, err, partial = self.conn:receive(self._pattern);
	if data then
		self:onconnect();
		self:on("incoming", data);
	else
		if partial and partial ~= "" then
			self:onconnect();
			self:on("incoming", partial, err);
		end
		if err == "wantread" then
			self:setflags(true, nil);
		elseif err == "wantwrite" then
			self:setflags(nil, true);
		elseif err ~= "timeout" then
			self:on("disconnect", err);
			self:destroy()
			return;
		end
	end
	if not self.conn then return; end
	if self.conn:dirty() then
		self:setreadtimeout(false);
		self:pausefor(cfg.read_retry_delay);
	else
		self:setreadtimeout();
	end
end

-- Called when socket is writable
function interface:onwriteable()
	local buffer = self.writebuffer;
	local data = t_concat(buffer);
	local ok, err, partial = self.conn:send(data);
	if ok then
		self:setflags(nil, false);
		for i = #buffer, 1, -1 do
			buffer[i] = nil;
		end
		self:setwritetimeout(false);
		self:ondrain(); -- Be aware of writes in ondrain
		self:onconnect();
		return;
	elseif partial then
		buffer[1] = data:sub(partial+1);
		for i = #buffer, 2, -1 do
			buffer[i] = nil;
		end
		self:setwritetimeout();
	end
	if err == "wantwrite" or err == "timeout" then
		self:setflags(nil, true);
	elseif err == "wantread" then
		self:setflags(true, nil);
	elseif err ~= "timeout" then
		self:on("disconnect", err);
		self:destroy();
	end
end

-- The write buffer has been successfully emptied
function interface:ondrain()
	return self:on("drain");
end

-- Add data to write buffer and set flag for wanting to write
function interface:write(data)
	local buffer = self.writebuffer;
	if buffer then
		t_insert(buffer, data);
	else
		self.writebuffer = { data };
	end
	self:setwritetimeout();
	self:setflags(nil, true);
	return #data;
end
interface.send = interface.write;

-- Close, possibly after writing is done
function interface:close()
	if self.writebuffer and self.writebuffer[1] then
		self:setflags(false, true); -- Flush final buffer contents
		self.write, self.send = noop, noop; -- No more writing
		log("debug", "Close %s after writing", tostring(self));
		self.ondrain = interface.close;
	else
		log("debug", "Close %s now", tostring(self));
		self.write, self.send = noop, noop;
		self.close = noop;
		self:on("disconnect");
		self:destroy();
	end
end

function interface:destroy()
	self:setflags(false, false);
	self:setwritetimeout(false);
	self:setreadtimeout(false);
	self.onreadable = noop;
	self.onwriteable = noop;
	self.destroy = noop;
	self.close = noop;
	self.on = noop;
	self.conn:close();
	self.conn = nil;
end

function interface:ssl()
	return self._tls;
end

function interface:starttls(ctx)
	if ctx then self.tls = ctx; end
	if self.writebuffer and self.writebuffer[1] then
		log("debug", "Start TLS on %s after write", tostring(self));
		self.ondrain = interface.starttls;
		self.starttls = false;
		self:setflags(nil, true); -- make sure wantwrite is set
	else
		log("debug", "Start TLS on %s now", tostring(self));
		self:setflags(false, false);
		local conn, err = luasec.wrap(self.conn, ctx or self.tls);
		if not conn then
			self:on("disconnect", err);
			self:destroy();
			return conn, err;
		end
		conn:settimeout(0);
		self.conn = conn;
		self.ondrain = nil;
		self.onwriteable = interface.tlshandskake;
		self.onreadable = interface.tlshandskake;
		self:setflags(true, true);
		self:setwritetimeout(cfg.handshake_timeout);
	end
end

function interface:tlshandskake()
	self:setwritetimeout(false);
	self:setreadtimeout(false);
	local ok, err = self.conn:dohandshake();
	if ok then
		log("debug", "TLS handshake on %s complete", tostring(self));
		self.onwriteable = nil;
		self.onreadable = nil;
		self._tls = true;
		self:on("status", "ssl-handshake-complete");
		self:init();
	elseif err == "wantread" then
		log("debug", "TLS handshake on %s to wait until readable", tostring(self));
		self:setflags(true, false);
		self:setreadtimeout(cfg.handshake_timeout);
	elseif err == "wantwrite" then
		log("debug", "TLS handshake on %s to wait until writable", tostring(self));
		self:setflags(false, true);
		self:setwritetimeout(cfg.handshake_timeout);
	else
		log("debug", "TLS handshake error on %s: %s", tostring(self), err);
		self:on("disconnect", err);
		self:destroy();
	end
end

local function wrapsocket(client, server, pattern, listeners, tls) -- luasocket object -> interface object
	client:settimeout(0);
	local conn = setmetatable({
		conn = client;
		_server = server;
		created = gettime();
		listeners = listeners;
		_pattern = pattern or (server and server._pattern);
		writebuffer = {};
		tls = tls;
	}, interface_mt);

	if client.getpeername then
		conn.peername, conn.peerport = client:getpeername();
	end
	if client.getsockname then
		conn.sockname, conn.sockport = client:getsockname();
	end
	return conn;
end

-- A server interface has new incoming connections waiting
-- This replaces the onreadable callback
function interface:onacceptable()
	local conn, err = self.conn:accept();
	if not conn then
		log("debug", "Error accepting new client: %s, server will be paused for %ds", err, cfg.accept_retry_interval);
		self:pausefor(cfg.accept_retry_interval);
		return;
	end
	local client = wrapsocket(conn, self, nil, self.listeners, self.tls);
	log("debug", "New connection %s", tostring(client));
	client:init();
end

-- Initialization
function interface:init()
	if self.tls and not self._tls then
		return self:starttls();
	else
		self:setwritetimeout();
		return self:setflags(true, true);
	end
end

function interface:pause()
	return self:setflags(false);
end

function interface:resume()
	return self:setflags(true);
end

-- Pause connection for some time
function interface:pausefor(t)
	if self._pausefor then
		self._pausefor:close();
	end
	if t == false then return; end
	self:setflags(false);
	self._pausefor = addtimer(t, function ()
		self._pausefor = nil;
		if self.conn and self.conn:dirty() then
			self:onreadable();
		end
		self:setflags(true);
	end);
end

-- Connected!
function interface:onconnect()
	self.onconnect = noop;
	self:on("connect");
end

local function addserver(addr, port, listeners, pattern, tls)
	local conn, err = socket.bind(addr, port, cfg.tcp_backlog);
	if not conn then return conn, err; end
	conn:settimeout(0);
	local server = setmetatable({
		conn = conn;
		created = gettime();
		listeners = listeners;
		_pattern = pattern;
		onreadable = interface.onacceptable;
		tls = tls;
		sockname = addr;
		sockport = port;
	}, interface_mt);
	server:setflags(true, false);
	return server;
end

-- COMPAT
local function wrapclient(conn, addr, port, listeners, pattern, tls)
	local client = wrapsocket(conn, nil, pattern, listeners, tls);
	if not client.peername then
		client.peername, client.peerport = addr, port;
	end
	client:init();
	return client;
end

-- New outgoing TCP connection
local function addclient(addr, port, listeners, pattern, tls)
	local conn, err = socket.tcp();
	if not conn then return conn, err; end
	conn:settimeout(0);
	conn:connect(addr, port);
	local client = wrapsocket(conn, nil, pattern, listeners, tls)
	client:init();
	return client, conn;
end

-- Dump all data from one connection into another
local function link(from, to)
	from.listeners = setmetatable({
		onincoming = function (_, data)
			from:pause();
			to:write(data);
		end,
	}, {__index=from.listeners});
	to.listeners = setmetatable({
		ondrain = function ()
			from:resume();
		end,
	}, {__index=to.listeners});
	from:setflags(true, nil);
	to:setflags(nil, true);
end

-- XXX What uses this?
-- net.adns
function interface:set_send(new_send)
	self.send = new_send;
end

-- Close all connections and servers
local function closeall()
	for fd, conn in pairs(fds) do -- luacheck: ignore 213/fd
		conn:close();
	end
end

local quitting = nil;

-- Signal main loop about shutdown via above upvalue
local function setquitting(quit)
	if quit then
		quitting = "quitting";
		closeall();
	else
		quitting = nil;
	end
end

-- Main loop
local function loop(once)
	repeat
		local t = runtimers(cfg.max_wait, cfg.min_wait);
		local fd, r, w = epoll.wait(t);
		if fd then
			local conn = fds[fd];
			if conn then
				if r then
					conn:onreadable();
				end
				if w then
					conn:onwriteable();
				end
			else
				log("debug", "Removing unknown fd %d", fd);
				epoll.ctl("del", fd);
			end
		elseif r ~= "timeout" then
			log("debug", "epoll_wait error: %s", tostring(r));
		end
	until once or (quitting and next(fds) == nil);
	return quitting;
end

return {
	get_backend = function () return "epoll"; end;
	addserver = addserver;
	addclient = addclient;
	add_task = addtimer;
	at = at;
	loop = loop;
	closeall = closeall;
	setquitting = setquitting;
	wrapclient = wrapclient;
	link = link;
	set_config = function (newconfig)
		cfg = setmetatable(newconfig, default_config);
	end;

	-- libevent emulation
	event = { EV_READ = "r", EV_WRITE = "w", EV_READWRITE = "rw", EV_LEAVE = -1 };
	addevent = function (fd, mode, callback)
		local function onevent(self)
			local ret = self:callback();
			if ret == -1 then
				self:setflags(false, false);
			elseif ret then
				self:setflags(mode == "r" or mode == "rw", mode == "w" or mode == "rw");
			end
		end

		local conn = setmetatable({
			getfd = function () return fd; end;
			callback = callback;
			onreadable = onevent;
			onwriteable = onevent;
			close = function (self)
				self:setflags(false, false);
				fds[fd] = nil;
			end;
		}, interface_mt);
		local ok, err = conn:setflags(mode == "r" or mode == "rw", mode == "w" or mode == "rw");
		if not ok then return ok, err; end
		return conn;
	end;
};