aboutsummaryrefslogtreecommitdiffstats
path: root/plugins/mod_bosh.lua
blob: 71be632e5527a56c84d88d2adfa5e206fd3bc1ee (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
-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

module:set_global(); -- Global module

local hosts = _G.hosts;
local new_xmpp_stream = require "util.xmppstream".new;
local sm = require "core.sessionmanager";
local sm_destroy_session = sm.destroy_session;
local new_uuid = require "util.uuid".generate;
local core_process_stanza = prosody.core_process_stanza;
local st = require "util.stanza";
local logger = require "util.logger";
local log = logger.init("mod_bosh");
local initialize_filters = require "util.filters".initialize;
local math_min = math.min;
local tostring, type = tostring, type;
local traceback = debug.traceback;
local runner = require"util.async".runner;
local nameprep = require "util.encodings".stringprep.nameprep;

local xmlns_streams = "http://etherx.jabber.org/streams";
local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";
local xmlns_bosh = "http://jabber.org/protocol/httpbind"; -- (hard-coded into a literal in session.send)

local stream_callbacks = {
	stream_ns = xmlns_bosh, stream_tag = "body", default_ns = "jabber:client" };

-- These constants are implicitly assumed within the code, and cannot be changed
local BOSH_HOLD = 1;
local BOSH_MAX_REQUESTS = 2;

-- The number of seconds a BOSH session should remain open with no requests
local bosh_max_inactivity = module:get_option_number("bosh_max_inactivity", 60);
-- The minimum amount of time between requests with no payload
local bosh_max_polling = module:get_option_number("bosh_max_polling", 5);
-- The maximum amount of time that the server will hold onto a request before replying
-- (the client can set this to a lower value when it connects, if it chooses)
local bosh_max_wait = module:get_option_number("bosh_max_wait", 120);

local consider_bosh_secure = module:get_option_boolean("consider_bosh_secure");
local cross_domain = module:get_option("cross_domain_bosh", false);

if cross_domain == true then cross_domain = "*"; end
if type(cross_domain) == "table" then cross_domain = table.concat(cross_domain, ", "); end

local trusted_proxies = module:get_option_set("trusted_proxies", { "127.0.0.1", "::1" })._items;

local function get_ip_from_request(request)
	local ip = request.conn:ip();
	local forwarded_for = request.headers.x_forwarded_for;
	if forwarded_for then
		forwarded_for = forwarded_for..", "..ip;
		for forwarded_ip in forwarded_for:gmatch("[^%s,]+") do
			if not trusted_proxies[forwarded_ip] then
				ip = forwarded_ip;
			end
		end
	end
	return ip;
end

local t_insert, t_remove, t_concat = table.insert, table.remove, table.concat;

-- All sessions, and sessions that have no requests open
local sessions = module:shared("sessions");

-- Used to respond to idle sessions (those with waiting requests)
function on_destroy_request(request)
	log("debug", "Request destroyed: %s", tostring(request));
	local session = sessions[request.context.sid];
	if session then
		local requests = session.requests;
		for i, r in ipairs(requests) do
			if r == request then
				t_remove(requests, i);
				break;
			end
		end

		-- If this session now has no requests open, mark it as inactive
		local max_inactive = session.bosh_max_inactive;
		if max_inactive and #requests == 0 then
			if session.inactive_timer then
				session.inactive_timer:stop();
			end
			session.inactive_timer = module:add_timer(max_inactive, check_inactive, session, request.context,
				"BOSH client silent for over "..max_inactive.." seconds");
			(session.log or log)("debug", "BOSH session marked as inactive (for %ds)", max_inactive);
		end
		if session.bosh_wait_timer then
			session.bosh_wait_timer:stop();
			session.bosh_wait_timer = nil;
		end
	end
end

function check_inactive(now, session, context, reason) -- luacheck: ignore 212/now
	if not session.destroyed then
		sessions[context.sid] = nil;
		sm_destroy_session(session, reason);
	end
end

local function set_cross_domain_headers(response)
	local headers = response.headers;
	headers.access_control_allow_methods = "GET, POST, OPTIONS";
	headers.access_control_allow_headers = "Content-Type";
	headers.access_control_max_age = "7200";
	headers.access_control_allow_origin = cross_domain;
	return response;
end

function handle_OPTIONS(event)
	if cross_domain and event.request.headers.origin then
		set_cross_domain_headers(event.response);
	end
	return "";
end

function handle_POST(event)
	log("debug", "Handling new request %s: %s\n----------", tostring(event.request), tostring(event.request.body));

	local request, response = event.request, event.response;
	response.on_destroy = on_destroy_request;
	local body = request.body;

	local context = { request = request, response = response, notopen = true };
	local stream = new_xmpp_stream(context, stream_callbacks);
	response.context = context;

	local headers = response.headers;
	headers.content_type = "text/xml; charset=utf-8";

	if cross_domain and request.headers.origin then
		set_cross_domain_headers(response);
	end

	-- stream:feed() calls the stream_callbacks, so all stanzas in
	-- the body are processed in this next line before it returns.
	-- In particular, the streamopened() stream callback is where
	-- much of the session logic happens, because it's where we first
	-- get to see the 'sid' of this request.
	local ok, err = stream:feed(body);
	if not ok then
		module:log("warn", "Error parsing BOSH payload; %s", err)
		local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
			["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
		return tostring(close_reply);
	end

	-- Stanzas (if any) in the request have now been processed, and
	-- we take care of the high-level BOSH logic here, including
	-- giving a response or putting the request "on hold".
	local session = sessions[context.sid];
	if session then
		-- Session was marked as inactive, since we have
		-- a request open now, unmark it
		if session.inactive_timer and #session.requests > 0 then
			session.inactive_timer:stop();
			session.inactive_timer = nil;
		end

		if session.bosh_wait_timer then
			session.bosh_wait_timer:stop();
			session.bosh_wait_timer = nil;
		end

		local r = session.requests;
		log("debug", "Session %s has %d out of %d requests open", context.sid, #r, BOSH_HOLD);
		log("debug", "and there are %d things in the send_buffer:", #session.send_buffer);
		if #r > BOSH_HOLD then
			-- We are holding too many requests, send what's in the buffer,
			log("debug", "We are holding too many requests, so...");
			if #session.send_buffer > 0 then
				log("debug", "...sending what is in the buffer")
				session.send(t_concat(session.send_buffer));
				session.send_buffer = {};
			else
				-- or an empty response
				log("debug", "...sending an empty response");
				session.send("");
			end
		elseif #session.send_buffer > 0 then
			log("debug", "Session has data in the send buffer, will send now..");
			local resp = t_concat(session.send_buffer);
			session.send_buffer = {};
			session.send(resp);
		end

		if not response.finished then
			-- We're keeping this request open, to respond later
			log("debug", "Have nothing to say, so leaving request unanswered for now");
		end

		if session.bosh_terminate then
			session.log("debug", "Closing session with %d requests open", #session.requests);
			session:close();
			return nil;
		else
			if session.bosh_wait and #session.requests > 0 then
				session.bosh_wait_timer = module:add_timer(session.bosh_wait, after_bosh_wait, session.requests[1], session)
			end

			return true; -- Inform http server we shall reply later
		end
	elseif response.finished then
		return; -- A response has been sent already
	end
	module:log("warn", "Unable to associate request with a session (incomplete request?)");
	local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
		["xmlns:stream"] = xmlns_streams, condition = "item-not-found" });
	return tostring(close_reply) .. "\n";
end

function after_bosh_wait(now, request, session) -- luacheck: ignore 212
	if request.conn then
		session.send("");
	end
end

local function bosh_reset_stream(session) session.notopen = true; end

local stream_xmlns_attr = { xmlns = "urn:ietf:params:xml:ns:xmpp-streams" };

local function bosh_close_stream(session, reason)
	(session.log or log)("info", "BOSH client disconnected");

	local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
		["xmlns:stream"] = xmlns_streams });


	if reason then
		close_reply.attr.condition = "remote-stream-error";
		if type(reason) == "string" then -- assume stream error
			close_reply:tag("stream:error")
				:tag(reason, {xmlns = xmlns_xmpp_streams});
		elseif type(reason) == "table" then
			if reason.condition then
				close_reply:tag("stream:error")
					:tag(reason.condition, stream_xmlns_attr):up();
				if reason.text then
					close_reply:tag("text", stream_xmlns_attr):text(reason.text):up();
				end
				if reason.extra then
					close_reply:add_child(reason.extra);
				end
			elseif reason.name then -- a stanza
				close_reply = reason;
			end
		end
		log("info", "Disconnecting client, <stream:error> is: %s", tostring(close_reply));
	end

	local response_body = tostring(close_reply);
	for _, held_request in ipairs(session.requests) do
		held_request:send(response_body);
	end
	sessions[session.sid] = nil;
	sm_destroy_session(session);
end

local runner_callbacks = { };

-- Handle the <body> tag in the request payload.
function stream_callbacks.streamopened(context, attr)
	local request, response = context.request, context.response;
	local sid = attr.sid;
	log("debug", "BOSH body open (sid: %s)", sid or "<none>");
	if not sid then
		-- New session request
		context.notopen = nil; -- Signals that we accept this opening tag

		local to_host = nameprep(attr.to);
		local rid = tonumber(attr.rid);
		local wait = tonumber(attr.wait);
		if not to_host then
			log("debug", "BOSH client tried to connect to invalid host: %s", tostring(attr.to));
			local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
				["xmlns:stream"] = xmlns_streams, condition = "improper-addressing" });
			response:send(tostring(close_reply));
			return;
		elseif not hosts[to_host] then
			-- Unknown host
			log("debug", "BOSH client tried to connect to unknown host: %s", tostring(attr.to));
			local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
				["xmlns:stream"] = xmlns_streams, condition = "host-unknown" });
			response:send(tostring(close_reply));
			return;
		end
		if not rid or (not wait and attr.wait or wait < 0 or wait % 1 ~= 0) then
			log("debug", "BOSH client sent invalid rid or wait attributes: rid=%s, wait=%s", tostring(attr.rid), tostring(attr.wait));
			local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
				["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
			response:send(tostring(close_reply));
			return;
		end

		rid = rid - 1;
		wait = math_min(wait, bosh_max_wait);

		-- New session
		sid = new_uuid();
		local session = {
			type = "c2s_unauthed", conn = request.conn, sid = sid, rid = rid, host = attr.to,
			bosh_version = attr.ver, bosh_wait = wait, streamid = sid,
			bosh_max_inactive = bosh_max_inactivity,
			requests = { }, send_buffer = {}, reset_stream = bosh_reset_stream,
			close = bosh_close_stream, dispatch_stanza = core_process_stanza, notopen = true,
			log = logger.init("bosh"..sid),	secure = consider_bosh_secure or request.secure,
			ip = get_ip_from_request(request);
		};
		sessions[sid] = session;

		session.thread = runner(function (stanza)
			session:dispatch_stanza(stanza);
		end, runner_callbacks, session);

		local filter = initialize_filters(session);

		session.log("debug", "BOSH session created for request from %s", session.ip);
		log("info", "New BOSH session, assigned it sid '%s'", sid);

		hosts[session.host].events.fire_event("bosh-session", { session = session, request = request });

		-- Send creation response
		local creating_session = true;

		local r = session.requests;
		function session.send(s)
			-- We need to ensure that outgoing stanzas have the jabber:client xmlns
			if s.attr and not s.attr.xmlns then
				s = st.clone(s);
				s.attr.xmlns = "jabber:client";
			end
			s = filter("stanzas/out", s);
			--log("debug", "Sending BOSH data: %s", tostring(s));
			if not s then return true end
			t_insert(session.send_buffer, tostring(s));

			local oldest_request = r[1];
			if oldest_request and not session.bosh_processing then
				log("debug", "We have an open request, so sending on that");
				local body_attr = { xmlns = "http://jabber.org/protocol/httpbind",
					["xmlns:stream"] = "http://etherx.jabber.org/streams";
					type = session.bosh_terminate and "terminate" or nil;
					sid = sid;
				};
				if creating_session then
					creating_session = nil;
					body_attr.requests = tostring(BOSH_MAX_REQUESTS);
					body_attr.hold = tostring(BOSH_HOLD);
					body_attr.inactivity = tostring(bosh_max_inactivity);
					body_attr.polling = tostring(bosh_max_polling);
					body_attr.wait = tostring(session.bosh_wait);
					body_attr.authid = sid;
					body_attr.secure = "true";
					body_attr.ver  = '1.6';
					body_attr.from = session.host;
					body_attr["xmlns:xmpp"] = "urn:xmpp:xbosh";
					body_attr["xmpp:version"] = "1.0";
				end
				session.bosh_last_response = st.stanza("body", body_attr):top_tag()..t_concat(session.send_buffer).."</body>";
				oldest_request:send(session.bosh_last_response);
				session.send_buffer = {};
			end
			return true;
		end
		request.sid = sid;
	end

	local session = sessions[sid];
	if not session then
		-- Unknown sid
		log("info", "Client tried to use sid '%s' which we don't know about", sid);
		response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
		context.notopen = nil;
		return;
	end

	session.conn = request.conn;

	if session.rid then
		local rid = tonumber(attr.rid);
		local diff = rid - session.rid;
		-- Diff should be 1 for a healthy request
		if diff ~= 1 then
			context.sid = sid;
			context.notopen = nil;
			if diff == 2 then
				-- Hold request, but don't process it (ouch!)
				session.log("debug", "rid skipped: %d, deferring this request", rid-1)
				context.defer = true;
				session.bosh_deferred = { context = context, sid = sid, rid = rid, terminate = attr.type == "terminate" };
				return;
			end
			context.ignore = true;
			if diff == 0 then
				-- Re-send previous response, ignore stanzas in this request
				session.log("debug", "rid repeated, ignoring: %s (diff %d)", session.rid, diff);
				response:send(session.bosh_last_response);
				return;
			end
			-- Session broken, destroy it
			session.log("debug", "rid out of range: %d (diff %d)", rid, diff);
			response:send(tostring(st.stanza("body", { xmlns = xmlns_bosh, type = "terminate", condition = "item-not-found" })));
			return;
		end
		session.rid = rid;
	end

	if attr.type == "terminate" then
		-- Client wants to end this session, which we'll do
		-- after processing any stanzas in this request
		session.bosh_terminate = true;
	end

	context.notopen = nil; -- Signals that we accept this opening tag
	t_insert(session.requests, response);
	context.sid = sid;
	session.bosh_processing = true; -- Used to suppress replies until processing of this request is done

	if session.notopen then
		local features = st.stanza("stream:features");
		hosts[session.host].events.fire_event("stream-features", { origin = session, features = features });
		session.send(features);
		session.notopen = nil;
	end
end

local function handleerr(err) log("error", "Traceback[bosh]: %s", traceback(tostring(err), 2)); end

function runner_callbacks:error(err) -- luacheck: ignore 212/self
	return handleerr(err);
end

function stream_callbacks.handlestanza(context, stanza)
	if context.ignore then return; end
	log("debug", "BOSH stanza received: %s\n", stanza:top_tag());
	local session = sessions[context.sid];
	if session then
		if stanza.attr.xmlns == xmlns_bosh then
			stanza.attr.xmlns = nil;
		end
		if context.defer and session.bosh_deferred then
			log("debug", "Deferring this stanza");
			t_insert(session.bosh_deferred, stanza);
		else
			stanza = session.filter("stanzas/in", stanza);
			session.thread:run(stanza);
		end
	else
		log("debug", "No session for this stanza! (sid: %s)", context.sid or "none!");
	end
end

function stream_callbacks.streamclosed(context)
	local session = sessions[context.sid];
	if session then
		if not context.defer and session.bosh_deferred then
			-- Handle deferred stanzas now
			local deferred_stanzas = session.bosh_deferred;
			local deferred_context = deferred_stanzas.context;
			session.bosh_deferred = nil;
			log("debug", "Handling deferred stanzas from rid %d", deferred_stanzas.rid);
			session.rid = deferred_stanzas.rid;
			t_insert(session.requests, deferred_context.response);
			for _, stanza in ipairs(deferred_stanzas) do
				stream_callbacks.handlestanza(deferred_context, stanza);
			end
			if deferred_stanzas.terminate then
				session.bosh_terminate = true;
			end
		end
		session.bosh_processing = false;
		if #session.send_buffer > 0 then
			session.send("");
		end
	end
end

function stream_callbacks.error(context, error)
	log("debug", "Error parsing BOSH request payload; %s", error);
	if not context.sid then
		local response = context.response;
		local close_reply = st.stanza("body", { xmlns = xmlns_bosh, type = "terminate",
			["xmlns:stream"] = xmlns_streams, condition = "bad-request" });
		response:send(tostring(close_reply));
		return;
	end

	local session = sessions[context.sid];
	if error == "stream-error" then -- Remote stream error, we close normally
		session:close();
	else
		session:close({ condition = "bad-format", text = "Error processing stream" });
	end
end

local GET_response = {
	headers = {
		content_type = "text/html";
	};
	body = [[<html><body>
	<p>It works! Now point your BOSH client to this URL to connect to Prosody.</p>
	<p>For more information see <a href="https://prosody.im/doc/setting_up_bosh">Prosody: Setting up BOSH</a>.</p>
	</body></html>]];
};

function module.add_host(module)
	module:depends("http");
	module:provides("http", {
		default_path = "/http-bind";
		route = {
			["GET"] = GET_response;
			["GET /"] = GET_response;
			["OPTIONS"] = handle_OPTIONS;
			["OPTIONS /"] = handle_OPTIONS;
			["POST"] = handle_POST;
			["POST /"] = handle_POST;
		};
	});
end