aboutsummaryrefslogtreecommitdiffstats
path: root/net/server_epoll.lua
blob: f4ec54f66ae080f291fe0f515e9e582e1e0b8d0b (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
-- 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 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 _ENV = nil;

local cfg = {
	read_timeout = 900;
	write_timeout = 7;
	tcp_backlog = 128;
	accept_retry_interval = 10;
	read_retry_delay = 1e-06;
};

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

	--[[ Is it worth it to skip the noop calls?
	for i = #timers, 1, -1 do
		if timers[i][2] == noop then
			timers[i] = nil;
		else
			break;
		end
	end
	--]]

	local next_delay = 86400;

	-- 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];
		local now = gettime(); -- inside or before the loop?
		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
			timer[1] = t + new_timeout;
			resort_timers = true;
		else
			t_remove(timers, i);
		end
	end
	if resort_timers or next_delay < 1e-6 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 = 1e-6;
	end
	return next_delay;
end

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

function interface:setlistener(listeners)
	self.listeners = listeners;
end

-- Call callback
function interface:on(what, ...)
	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

function interface:getfd()
	return self.conn:getfd();
end

function interface:ip()
	return self.peername or self.sockname;
end

function interface:port()
	return self.sockport or self.peerport;
end

function interface:clientport()
	return self.sockport;
end

function interface:serverport()
	if self.sockport then
		return self.sockport;
	elseif self.server then
		self.server:port();
	end
end

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

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

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

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

function interface:flags()
	if self._wantread then
		if self._wantwrite then
			return "rw";
		end
		return "r";
	elseif self._wantwrite then
		return "w";
	end
end

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();
	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
	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 or partial then
		self:on("incoming", data or partial, err);
	end
	if err == "wantread" then
		self:setflags(true, nil);
	elseif err == "wantwrite" then
		self:setflags(nil, true);
	elseif not data and err ~= "timeout" then
		self:on("disconnect", err);
		self:destroy()
		return;
	end
	self:setreadtimeout();
	if self.conn:dirty() then
		self:pausefor(cfg.read_retry_delay);
	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
		for i = #buffer, 1, -1 do
			buffer[i] = nil;
		end
		self:setflags(nil, false);
		self:setwritetimeout(false);
		self:ondrain(); -- Be aware of writes in ondrain
	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 and err ~= "timeout" then
		self:on("disconnect", err);
		self:destroy();
	end
end

function interface:ondrain()
	self:on("drain");
	if self._starttls then
		self:starttls();
	elseif self._toclose then
		self:close();
	end
end

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;

function interface:close()
	if self._wantwrite then
		log("debug", "Close %s after writing", tostring(self));
		self._toclose = true;
	else
		log("debug", "Close %s", tostring(self));
		self.close = noop;
		self:on("disconnect");
		self:destroy();
	end
end

function interface:destroy()
	self:setflags(false, false);
	self:setwritetimeout(false);
	self:setreadtimeout(false);
	fds[self:getfd()] = nil;
	return self.conn:close();
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
		self._starttls = true;
	else
		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();
		end
		conn:settimeout(0);
		self.conn = conn;
		self._starttls = nil;
		self.onwriteable = interface.tlshandskake;
		self.onreadable = interface.tlshandskake;
		self:setflags(true, true);
	end
end

function interface:tlshandskake()
	local ok, err = self.conn:dohandshake();
	if ok then
		self.onwriteable = nil;
		self.onreadable = nil;
		self:setflags(true, true);
		local old = self._tls;
		self._tls = true;
		self.starttls = false;
		if old == false then
			self:on("connect");
		else
			self:on("status", "ssl-handshake-complete");
		end
	elseif err == "wantread" then
		self:setflags(true, false);
		self:setwritetimeout(false);
		self:setreadtimeout(cfg.handshake_timeout);
	elseif err == "wantwrite" then
		self:setflags(false, true);
		self:setreadtimeout(false);
		self:setwritetimeout(cfg.handshake_timeout);
	else
		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._pattern;
		onwriteable = interface.onconnect;
		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

	fds[conn:getfd()] = conn;
	return conn;
end

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);
	if self.tls then
		client._tls = false;
		client:starttls();
	else
		client:setflags(false, true);
	end
	client:setreadtimeout();
end

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

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

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;
		self:setflags(true);
		if self.conn:dirty() then
			self:onreadable();
		end
	end);
end

function interface:onconnect()
	self.onwriteable = nil;
	self:on("connect");
	self:setflags(true);
	return self:onwriteable();
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);
	fds[server:getfd()] = server;
	return server;
end

-- COMPAT
local function wrapclient(conn, addr, port, listeners, pattern, tls)
	local client = setmetatable({
		conn = conn;
		created = gettime();
		listeners = listeners;
		_pattern = pattern;
		writebuffer = {};
		tls = tls;
		onwriteable = interface.onconnect;
		peer = { addr, port };
	}, interface_mt);
	fds[client:getfd()] = client;
	client:setflags(false, true);
	return client;
end

local function addclient(addr, port, listeners, pattern, tls)
	local conn, err = socket.connect(addr, port);
	if not conn then return conn, err; end
	conn:settimeout(0);
	local client = wrapclient(conn, addr, port, listeners, pattern, tls);
	if tls then
		client._tls = false;
		client:starttls();
	else
		client:setflags(true, true);
	end
	return client, conn;
end

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

local quitting = nil;

local function setquitting()
	quitting = "quitting";
end

local function loop()
	repeat
		local t = runtimers();
		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 quitting;
	return quitting;
end

return {
	get_backend = function () return "epoll"; end;
	addserver = addserver;
	addclient = addclient;
	add_task = addtimer;
	at = at;
	loop = loop;
	setquitting = setquitting;
	wrapclient = wrapclient;
	link = link;

	-- 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
				epoll.ctl("del", fd);
			elseif ret then
				epoll.ctl("mod", fd, mode);
			end
		end

		local conn = {
			callback = callback;
			onreadable = onevent;
			onwriteable = onevent;
			close = function ()
				fds[fd] = nil;
				return epoll.ctl("del", fd);
			end;
		};
		fds[fd] = conn;
		local ok, err = epoll.ctl("add", fd, mode or "r");
		if not ok then return ok, err; end
		return conn;
	end;
};